This is python.info, produced by makeinfo version 6.5 from python.texi. Python 3.8.9, September 01, 2021 unknown Copyright © 2001-2021, Python Software Foundation INFO-DIR-SECTION Miscellaneous START-INFO-DIR-ENTRY * python: (python.info). One line description of project END-INFO-DIR-ENTRY Generated by Sphinx 2.4.4.  File: python.info, Node: Top, Next: What’s New in Python, Up: (dir) Python ****** Python 3.8.9, September 01, 2021 unknown Copyright © 2001-2021, Python Software Foundation * Menu: * What’s New in Python:: * The Python Tutorial:: * Python Setup and Usage:: * The Python Language Reference:: * The Python Standard Library:: * Extending and Embedding the Python Interpreter:: * Python/C API Reference Manual:: * Distributing Python Modules:: * Installing Python Modules:: * Python HOWTOs:: * Python Frequently Asked Questions:: * Glossary:: * About these documents:: * Dealing with Bugs:: * Copyright:: * History and License:: * Distributing Python Modules (Legacy version): Distributing Python Modules Legacy version. * Installing Python Modules (Legacy version): Installing Python Modules Legacy version. * Python Module Index:: * Index:: — The Detailed Node Listing — What’s New in Python * What’s New In Python 3.8: What’s New In Python 3 8. * What’s New In Python 3.7: What’s New In Python 3 7. * What’s New In Python 3.6: What’s New In Python 3 6. * What’s New In Python 3.5: What’s New In Python 3 5. * What’s New In Python 3.4: What’s New In Python 3 4. * What’s New In Python 3.3: What’s New In Python 3 3. * What’s New In Python 3.2: What’s New In Python 3 2. * What’s New In Python 3.1: What’s New In Python 3 1. * What’s New In Python 3.0: What’s New In Python 3 0. * What’s New in Python 2.7: What’s New in Python 2 7. * What’s New in Python 2.6: What’s New in Python 2 6. * What’s New in Python 2.5: What’s New in Python 2 5. * What’s New in Python 2.4: What’s New in Python 2 4. * What’s New in Python 2.3: What’s New in Python 2 3. * What’s New in Python 2.2: What’s New in Python 2 2. * What’s New in Python 2.1: What’s New in Python 2 1. * What’s New in Python 2.0: What’s New in Python 2 0. * Changelog:: What’s New In Python 3.8 * Summary – Release highlights:: * New Features:: * Other Language Changes:: * New Modules:: * Improved Modules:: * Optimizations:: * Build and C API Changes:: * Deprecated:: * API and Feature Removals:: * Porting to Python 3.8: Porting to Python 3 8. * Notable changes in Python 3.8.1: Notable changes in Python 3 8 1. * Notable changes in Python 3.8.2: Notable changes in Python 3 8 2. * Notable changes in Python 3.8.3: Notable changes in Python 3 8 3. * Notable changes in Python 3.8.8: Notable changes in Python 3 8 8. * Notable changes in Python 3.8.9: Notable changes in Python 3 8 9. New Features * Assignment expressions:: * Positional-only parameters:: * Parallel filesystem cache for compiled bytecode files:: * Debug build uses the same ABI as release build:: * f-strings support = for self-documenting expressions and debugging:: * PEP 578; Python Runtime Audit Hooks: PEP 578 Python Runtime Audit Hooks. * PEP 587; Python Initialization Configuration: PEP 587 Python Initialization Configuration. * Vectorcall; a fast calling protocol for CPython: Vectorcall a fast calling protocol for CPython. * Pickle protocol 5 with out-of-band data buffers:: Improved Modules * ast:: * asyncio:: * builtins:: * collections:: * cProfile:: * csv:: * curses:: * ctypes:: * datetime:: * functools:: * gc:: * gettext:: * gzip:: * IDLE and idlelib:: * inspect:: * io:: * itertools:: * json.tool: json tool. * logging:: * math:: * mmap:: * multiprocessing:: * os:: * os.path: os path. * pathlib:: * pickle:: * plistlib:: * pprint:: * py_compile:: * shlex:: * shutil:: * socket:: * ssl:: * statistics:: * sys:: * tarfile:: * threading:: * tokenize:: * tkinter:: * time:: * typing:: * unicodedata:: * unittest:: * venv:: * weakref:: * xml:: * xmlrpc:: Porting to Python 3.8 * Changes in Python behavior:: * Changes in the Python API:: * Changes in the C API:: * CPython bytecode changes:: * Demos and Tools:: What’s New In Python 3.7 * Summary – Release Highlights:: * New Features: New Features<2>. * Other Language Changes: Other Language Changes<2>. * New Modules: New Modules<2>. * Improved Modules: Improved Modules<2>. * C API Changes:: * Build Changes:: * Optimizations: Optimizations<2>. * Other CPython Implementation Changes:: * Deprecated Python Behavior:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods. * Deprecated functions and types of the C API:: * Platform Support Removals:: * API and Feature Removals: API and Feature Removals<2>. * Module Removals:: * Windows-only Changes:: * Porting to Python 3.7: Porting to Python 3 7. * Notable changes in Python 3.7.1: Notable changes in Python 3 7 1. * Notable changes in Python 3.7.2: Notable changes in Python 3 7 2. * Notable changes in Python 3.7.6: Notable changes in Python 3 7 6. * Notable changes in Python 3.7.10: Notable changes in Python 3 7 10. New Features * PEP 563; Postponed Evaluation of Annotations: PEP 563 Postponed Evaluation of Annotations. * PEP 538; Legacy C Locale Coercion: PEP 538 Legacy C Locale Coercion. * PEP 540; Forced UTF-8 Runtime Mode: PEP 540 Forced UTF-8 Runtime Mode. * PEP 553; Built-in breakpoint(): PEP 553 Built-in breakpoint. * PEP 539; New C API for Thread-Local Storage: PEP 539 New C API for Thread-Local Storage. * PEP 562; Customization of Access to Module Attributes: PEP 562 Customization of Access to Module Attributes. * PEP 564; New Time Functions With Nanosecond Resolution: PEP 564 New Time Functions With Nanosecond Resolution. * PEP 565; Show DeprecationWarning in __main__: PEP 565 Show DeprecationWarning in __main__. * PEP 560; Core Support for typing module and Generic Types: PEP 560 Core Support for typing module and Generic Types. * PEP 552; Hash-based .pyc Files: PEP 552 Hash-based pyc Files. * PEP 545; Python Documentation Translations: PEP 545 Python Documentation Translations. * Development Runtime Mode; -X dev: Development Runtime Mode -X dev. New Modules * contextvars:: * dataclasses:: * importlib.resources: importlib resources. Improved Modules * argparse:: * asyncio: asyncio<2>. * binascii:: * calendar:: * collections: collections<2>. * compileall:: * concurrent.futures: concurrent futures. * contextlib:: * cProfile: cProfile<2>. * crypt:: * datetime: datetime<2>. * dbm:: * decimal:: * dis:: * distutils:: * enum:: * functools: functools<2>. * gc: gc<2>. * hmac:: * http.client: http client. * http.server: http server. * idlelib and IDLE:: * importlib:: * io: io<2>. * ipaddress:: * itertools: itertools<2>. * locale:: * logging: logging<2>. * math: math<2>. * mimetypes:: * msilib:: * multiprocessing: multiprocessing<2>. * os: os<2>. * pathlib: pathlib<2>. * pdb:: * py_compile: py_compile<2>. * pydoc:: * queue:: * re:: * signal:: * socket: socket<2>. * socketserver:: * sqlite3:: * ssl: ssl<2>. * string:: * subprocess:: * sys: sys<2>. * time: time<2>. * tkinter: tkinter<2>. * tracemalloc:: * types:: * unicodedata: unicodedata<2>. * unittest: unittest<2>. * unittest.mock: unittest mock. * urllib.parse: urllib parse. * uu:: * uuid:: * warnings:: * xml.etree: xml etree. * xmlrpc.server: xmlrpc server. * zipapp:: * zipfile:: Deprecated Python modules, functions and methods * aifc:: * asyncio: asyncio<3>. * collections: collections<3>. * dbm: dbm<2>. * enum: enum<2>. * gettext: gettext<2>. * importlib: importlib<2>. * locale: locale<2>. * macpath:: * threading: threading<2>. * socket: socket<3>. * ssl: ssl<3>. * sunau:: * sys: sys<3>. * wave:: Porting to Python 3.7 * Changes in Python Behavior:: * Changes in the Python API: Changes in the Python API<2>. * Changes in the C API: Changes in the C API<2>. * CPython bytecode changes: CPython bytecode changes<2>. * Windows-only Changes: Windows-only Changes<2>. * Other CPython implementation changes:: What’s New In Python 3.6 * Summary – Release highlights: Summary – Release highlights<2>. * New Features: New Features<3>. * Other Language Changes: Other Language Changes<3>. * New Modules: New Modules<3>. * Improved Modules: Improved Modules<3>. * Optimizations: Optimizations<3>. * Build and C API Changes: Build and C API Changes<2>. * Other Improvements:: * Deprecated: Deprecated<2>. * Removed:: * Porting to Python 3.6: Porting to Python 3 6. * Notable changes in Python 3.6.2: Notable changes in Python 3 6 2. * Notable changes in Python 3.6.4: Notable changes in Python 3 6 4. * Notable changes in Python 3.6.5: Notable changes in Python 3 6 5. * Notable changes in Python 3.6.7: Notable changes in Python 3 6 7. * Notable changes in Python 3.6.10: Notable changes in Python 3 6 10. * Notable changes in Python 3.6.13: Notable changes in Python 3 6 13. New Features * PEP 498; Formatted string literals: PEP 498 Formatted string literals. * PEP 526; Syntax for variable annotations: PEP 526 Syntax for variable annotations. * PEP 515; Underscores in Numeric Literals: PEP 515 Underscores in Numeric Literals. * PEP 525; Asynchronous Generators: PEP 525 Asynchronous Generators. * PEP 530; Asynchronous Comprehensions: PEP 530 Asynchronous Comprehensions. * PEP 487; Simpler customization of class creation: PEP 487 Simpler customization of class creation. * PEP 487; Descriptor Protocol Enhancements: PEP 487 Descriptor Protocol Enhancements. * PEP 519; Adding a file system path protocol: PEP 519 Adding a file system path protocol. * PEP 495; Local Time Disambiguation: PEP 495 Local Time Disambiguation. * PEP 529; Change Windows filesystem encoding to UTF-8: PEP 529 Change Windows filesystem encoding to UTF-8. * PEP 528; Change Windows console encoding to UTF-8: PEP 528 Change Windows console encoding to UTF-8. * PEP 520; Preserving Class Attribute Definition Order: PEP 520 Preserving Class Attribute Definition Order. * PEP 468; Preserving Keyword Argument Order: PEP 468 Preserving Keyword Argument Order. * New dict implementation:: * PEP 523; Adding a frame evaluation API to CPython: PEP 523 Adding a frame evaluation API to CPython. * PYTHONMALLOC environment variable:: * DTrace and SystemTap probing support:: New Modules * secrets:: Improved Modules * array:: * ast: ast<2>. * asyncio: asyncio<4>. * binascii: binascii<2>. * cmath:: * collections: collections<4>. * concurrent.futures: concurrent futures<2>. * contextlib: contextlib<2>. * datetime: datetime<3>. * decimal: decimal<2>. * distutils: distutils<2>. * email:: * encodings:: * enum: enum<3>. * faulthandler:: * fileinput:: * hashlib:: * http.client: http client<2>. * idlelib and IDLE: idlelib and IDLE<2>. * importlib: importlib<3>. * inspect: inspect<2>. * json:: * logging: logging<3>. * math: math<3>. * multiprocessing: multiprocessing<3>. * os: os<3>. * pathlib: pathlib<3>. * pdb: pdb<2>. * pickle: pickle<2>. * pickletools:: * pydoc: pydoc<2>. * random:: * re: re<2>. * readline:: * rlcompleter:: * shlex: shlex<2>. * site:: * sqlite3: sqlite3<2>. * socket: socket<4>. * socketserver: socketserver<2>. * ssl: ssl<4>. * statistics: statistics<2>. * struct:: * subprocess: subprocess<2>. * sys: sys<4>. * telnetlib:: * time: time<3>. * timeit:: * tkinter: tkinter<3>. * traceback:: * tracemalloc: tracemalloc<2>. * typing: typing<2>. * unicodedata: unicodedata<3>. * unittest.mock: unittest mock<2>. * urllib.request: urllib request. * urllib.robotparser: urllib robotparser. * venv: venv<2>. * warnings: warnings<2>. * winreg:: * winsound:: * xmlrpc.client: xmlrpc client. * zipfile: zipfile<2>. * zlib:: Deprecated * New Keywords:: * Deprecated Python behavior:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<2>. * Deprecated functions and types of the C API: Deprecated functions and types of the C API<2>. * Deprecated Build Options:: Deprecated Python modules, functions and methods * asynchat:: * asyncore:: * dbm: dbm<3>. * distutils: distutils<3>. * grp:: * importlib: importlib<4>. * os: os<4>. * re: re<3>. * ssl: ssl<5>. * tkinter: tkinter<4>. * venv: venv<3>. Removed * API and Feature Removals: API and Feature Removals<3>. Porting to Python 3.6 * Changes in ‘python’ Command Behavior:: * Changes in the Python API: Changes in the Python API<3>. * Changes in the C API: Changes in the C API<3>. * CPython bytecode changes: CPython bytecode changes<3>. Notable changes in Python 3.6.2 * New make regen-all build target:: * Removal of make touch build target:: What’s New In Python 3.5 * Summary – Release highlights: Summary – Release highlights<3>. * New Features: New Features<4>. * Other Language Changes: Other Language Changes<4>. * New Modules: New Modules<4>. * Improved Modules: Improved Modules<4>. * Other module-level changes:: * Optimizations: Optimizations<4>. * Build and C API Changes: Build and C API Changes<3>. * Deprecated: Deprecated<3>. * Removed: Removed<2>. * Porting to Python 3.5: Porting to Python 3 5. * Notable changes in Python 3.5.4: Notable changes in Python 3 5 4. New Features * PEP 492 - Coroutines with async and await syntax:: * PEP 465 - A dedicated infix operator for matrix multiplication:: * PEP 448 - Additional Unpacking Generalizations:: * PEP 461 - percent formatting support for bytes and bytearray:: * PEP 484 - Type Hints:: * PEP 471 - os.scandir() function – a better and faster directory iterator: PEP 471 - os scandir function – a better and faster directory iterator. * PEP 475; Retry system calls failing with EINTR: PEP 475 Retry system calls failing with EINTR. * PEP 479; Change StopIteration handling inside generators: PEP 479 Change StopIteration handling inside generators. * PEP 485; A function for testing approximate equality: PEP 485 A function for testing approximate equality. * PEP 486; Make the Python Launcher aware of virtual environments: PEP 486 Make the Python Launcher aware of virtual environments. * PEP 488; Elimination of PYO files: PEP 488 Elimination of PYO files. * PEP 489; Multi-phase extension module initialization: PEP 489 Multi-phase extension module initialization. New Modules * typing: typing<3>. * zipapp: zipapp<2>. Improved Modules * argparse: argparse<2>. * asyncio: asyncio<5>. * bz2:: * cgi:: * cmath: cmath<2>. * code:: * collections: collections<5>. * collections.abc: collections abc. * compileall: compileall<2>. * concurrent.futures: concurrent futures<3>. * configparser:: * contextlib: contextlib<3>. * csv: csv<2>. * curses: curses<2>. * dbm: dbm<4>. * difflib:: * distutils: distutils<4>. * doctest:: * email: email<2>. * enum: enum<4>. * faulthandler: faulthandler<2>. * functools: functools<3>. * glob:: * gzip: gzip<2>. * heapq:: * http:: * http.client: http client<3>. * idlelib and IDLE: idlelib and IDLE<3>. * imaplib:: * imghdr:: * importlib: importlib<5>. * inspect: inspect<3>. * io: io<3>. * ipaddress: ipaddress<2>. * json: json<2>. * linecache:: * locale: locale<3>. * logging: logging<4>. * lzma:: * math: math<4>. * multiprocessing: multiprocessing<4>. * operator:: * os: os<5>. * pathlib: pathlib<4>. * pickle: pickle<3>. * poplib:: * re: re<4>. * readline: readline<2>. * selectors:: * shutil: shutil<2>. * signal: signal<2>. * smtpd:: * smtplib:: * sndhdr:: * socket: socket<5>. * ssl: ssl<6>. * sqlite3: sqlite3<3>. * subprocess: subprocess<3>. * sys: sys<5>. * sysconfig:: * tarfile: tarfile<2>. * threading: threading<3>. * time: time<4>. * timeit: timeit<2>. * tkinter: tkinter<5>. * traceback: traceback<2>. * types: types<2>. * unicodedata: unicodedata<4>. * unittest: unittest<3>. * unittest.mock: unittest mock<3>. * urllib:: * wsgiref:: * xmlrpc: xmlrpc<2>. * xml.sax: xml sax. * zipfile: zipfile<3>. ssl * Memory BIO Support:: * Application-Layer Protocol Negotiation Support:: * Other Changes:: Deprecated * New Keywords: New Keywords<2>. * Deprecated Python Behavior: Deprecated Python Behavior<2>. * Unsupported Operating Systems:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<3>. Removed * API and Feature Removals: API and Feature Removals<4>. Porting to Python 3.5 * Changes in Python behavior: Changes in Python behavior<2>. * Changes in the Python API: Changes in the Python API<4>. * Changes in the C API: Changes in the C API<4>. Notable changes in Python 3.5.4 * New make regen-all build target: New make regen-all build target<2>. * Removal of make touch build target: Removal of make touch build target<2>. What’s New In Python 3.4 * Summary – Release Highlights: Summary – Release Highlights<2>. * New Features: New Features<5>. * New Modules: New Modules<5>. * Improved Modules: Improved Modules<5>. * CPython Implementation Changes:: * Deprecated: Deprecated<4>. * Removed: Removed<3>. * Porting to Python 3.4: Porting to Python 3 4. * Changed in 3.4.3: Changed in 3 4 3. New Features * PEP 453; Explicit Bootstrapping of PIP in Python Installations: PEP 453 Explicit Bootstrapping of PIP in Python Installations. * PEP 446; Newly Created File Descriptors Are Non-Inheritable: PEP 446 Newly Created File Descriptors Are Non-Inheritable. * Improvements to Codec Handling:: * PEP 451; A ModuleSpec Type for the Import System: PEP 451 A ModuleSpec Type for the Import System. * Other Language Changes: Other Language Changes<5>. PEP 453: Explicit Bootstrapping of PIP in Python Installations * Bootstrapping pip By Default:: * Documentation Changes:: New Modules * asyncio: asyncio<6>. * ensurepip:: * enum: enum<5>. * pathlib: pathlib<5>. * selectors: selectors<2>. * statistics: statistics<3>. * tracemalloc: tracemalloc<3>. Improved Modules * abc:: * aifc: aifc<2>. * argparse: argparse<3>. * audioop:: * base64:: * collections: collections<6>. * colorsys:: * contextlib: contextlib<4>. * dbm: dbm<5>. * dis: dis<2>. * doctest: doctest<2>. * email: email<3>. * filecmp:: * functools: functools<4>. * gc: gc<3>. * glob: glob<2>. * hashlib: hashlib<2>. * hmac: hmac<2>. * html:: * http: http<2>. * idlelib and IDLE: idlelib and IDLE<4>. * importlib: importlib<6>. * inspect: inspect<4>. * ipaddress: ipaddress<3>. * logging: logging<5>. * marshal:: * mmap: mmap<2>. * multiprocessing: multiprocessing<5>. * operator: operator<2>. * os: os<6>. * pdb: pdb<3>. * pickle: pickle<4>. * plistlib: plistlib<2>. * poplib: poplib<2>. * pprint: pprint<2>. * pty:: * pydoc: pydoc<3>. * re: re<5>. * resource:: * select:: * shelve:: * shutil: shutil<3>. * smtpd: smtpd<2>. * smtplib: smtplib<2>. * socket: socket<6>. * sqlite3: sqlite3<4>. * ssl: ssl<7>. * stat:: * struct: struct<2>. * subprocess: subprocess<4>. * sunau: sunau<2>. * sys: sys<6>. * tarfile: tarfile<3>. * textwrap:: * threading: threading<4>. * traceback: traceback<3>. * types: types<3>. * urllib: urllib<2>. * unittest: unittest<4>. * venv: venv<4>. * wave: wave<2>. * weakref: weakref<2>. * xml.etree: xml etree<2>. * zipfile: zipfile<4>. CPython Implementation Changes * PEP 445; Customization of CPython Memory Allocators: PEP 445 Customization of CPython Memory Allocators. * PEP 442; Safe Object Finalization: PEP 442 Safe Object Finalization. * PEP 456; Secure and Interchangeable Hash Algorithm: PEP 456 Secure and Interchangeable Hash Algorithm. * PEP 436; Argument Clinic: PEP 436 Argument Clinic. * Other Build and C API Changes:: * Other Improvements: Other Improvements<2>. * Significant Optimizations:: Deprecated * Deprecations in the Python API:: * Deprecated Features:: Removed * Operating Systems No Longer Supported:: * API and Feature Removals: API and Feature Removals<5>. * Code Cleanups:: Porting to Python 3.4 * Changes in ‘python’ Command Behavior: Changes in ‘python’ Command Behavior<2>. * Changes in the Python API: Changes in the Python API<5>. * Changes in the C API: Changes in the C API<5>. Changed in 3.4.3 * PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients. What’s New In Python 3.3 * Summary – Release highlights: Summary – Release highlights<4>. * PEP 405; Virtual Environments: PEP 405 Virtual Environments. * PEP 420; Implicit Namespace Packages: PEP 420 Implicit Namespace Packages. * PEP 3118; New memoryview implementation and buffer protocol documentation: PEP 3118 New memoryview implementation and buffer protocol documentation. * PEP 393; Flexible String Representation: PEP 393 Flexible String Representation. * PEP 397; Python Launcher for Windows: PEP 397 Python Launcher for Windows. * PEP 3151; Reworking the OS and IO exception hierarchy: PEP 3151 Reworking the OS and IO exception hierarchy. * PEP 380; Syntax for Delegating to a Subgenerator: PEP 380 Syntax for Delegating to a Subgenerator. * PEP 409; Suppressing exception context: PEP 409 Suppressing exception context. * PEP 414; Explicit Unicode literals: PEP 414 Explicit Unicode literals. * PEP 3155; Qualified name for classes and functions: PEP 3155 Qualified name for classes and functions. * PEP 412; Key-Sharing Dictionary: PEP 412 Key-Sharing Dictionary. * PEP 362; Function Signature Object: PEP 362 Function Signature Object. * PEP 421; Adding sys.implementation: PEP 421 Adding sys implementation. * Using importlib as the Implementation of Import:: * Other Language Changes: Other Language Changes<6>. * A Finer-Grained Import Lock:: * Builtin functions and types:: * New Modules: New Modules<6>. * Improved Modules: Improved Modules<6>. * Optimizations: Optimizations<5>. * Build and C API Changes: Build and C API Changes<4>. * Deprecated: Deprecated<5>. * Porting to Python 3.3: Porting to Python 3 3. PEP 3118: New memoryview implementation and buffer protocol documentation * Features:: * API changes:: PEP 393: Flexible String Representation * Functionality:: * Performance and resource usage:: PEP 421: Adding sys.implementation * SimpleNamespace:: Using importlib as the Implementation of Import * New APIs:: * Visible Changes:: New Modules * faulthandler: faulthandler<3>. * ipaddress: ipaddress<4>. * lzma: lzma<2>. Improved Modules * abc: abc<2>. * array: array<2>. * base64: base64<2>. * binascii: binascii<3>. * bz2: bz2<2>. * codecs:: * collections: collections<7>. * contextlib: contextlib<5>. * crypt: crypt<2>. * curses: curses<3>. * datetime: datetime<4>. * decimal: decimal<3>. * email: email<4>. * ftplib:: * functools: functools<5>. * gc: gc<4>. * hmac: hmac<3>. * http: http<3>. * html: html<2>. * imaplib: imaplib<2>. * inspect: inspect<5>. * io: io<4>. * itertools: itertools<3>. * logging: logging<6>. * math: math<5>. * mmap: mmap<3>. * multiprocessing: multiprocessing<6>. * nntplib:: * os: os<7>. * pdb: pdb<4>. * pickle: pickle<5>. * pydoc: pydoc<4>. * re: re<6>. * sched:: * select: select<2>. * shlex: shlex<3>. * shutil: shutil<4>. * signal: signal<3>. * smtpd: smtpd<3>. * smtplib: smtplib<3>. * socket: socket<7>. * socketserver: socketserver<3>. * sqlite3: sqlite3<5>. * ssl: ssl<8>. * stat: stat<2>. * struct: struct<3>. * subprocess: subprocess<5>. * sys: sys<7>. * tarfile: tarfile<4>. * tempfile:: * textwrap: textwrap<2>. * threading: threading<5>. * time: time<5>. * types: types<4>. * unittest: unittest<5>. * urllib: urllib<3>. * webbrowser:: * xml.etree.ElementTree: xml etree ElementTree. * zlib: zlib<2>. decimal * Features: Features<2>. * API changes: API changes<2>. email * Policy Framework:: * Provisional Policy with New Header API:: * Other API Changes:: Deprecated * Unsupported Operating Systems: Unsupported Operating Systems<2>. * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<4>. * Deprecated functions and types of the C API: Deprecated functions and types of the C API<3>. * Deprecated features:: Porting to Python 3.3 * Porting Python code:: * Porting C code:: * Building C extensions:: * Command Line Switch Changes:: What’s New In Python 3.2 * PEP 384; Defining a Stable ABI: PEP 384 Defining a Stable ABI. * PEP 389; Argparse Command Line Parsing Module: PEP 389 Argparse Command Line Parsing Module. * PEP 391; Dictionary Based Configuration for Logging: PEP 391 Dictionary Based Configuration for Logging. * PEP 3148; The concurrent.futures module: PEP 3148 The concurrent futures module. * PEP 3147; PYC Repository Directories: PEP 3147 PYC Repository Directories. * PEP 3149; ABI Version Tagged .so Files: PEP 3149 ABI Version Tagged so Files. * PEP 3333; Python Web Server Gateway Interface v1.0.1: PEP 3333 Python Web Server Gateway Interface v1 0 1. * Other Language Changes: Other Language Changes<7>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules. * Multi-threading:: * Optimizations: Optimizations<6>. * Unicode:: * Codecs:: * Documentation:: * IDLE:: * Code Repository:: * Build and C API Changes: Build and C API Changes<5>. * Porting to Python 3.2: Porting to Python 3 2. New, Improved, and Deprecated Modules * email: email<5>. * elementtree:: * functools: functools<6>. * itertools: itertools<4>. * collections: collections<8>. * threading: threading<6>. * datetime and time:: * math: math<6>. * abc: abc<3>. * io: io<5>. * reprlib:: * logging: logging<7>. * csv: csv<3>. * contextlib: contextlib<6>. * decimal and fractions:: * ftp:: * popen:: * select: select<3>. * gzip and zipfile:: * tarfile: tarfile<5>. * hashlib: hashlib<3>. * ast: ast<3>. * os: os<8>. * shutil: shutil<5>. * sqlite3: sqlite3<6>. * html: html<3>. * socket: socket<8>. * ssl: ssl<9>. * nntp:: * certificates:: * imaplib: imaplib<3>. * http.client: http client<4>. * unittest: unittest<6>. * random: random<2>. * poplib: poplib<3>. * asyncore: asyncore<2>. * tempfile: tempfile<2>. * inspect: inspect<6>. * pydoc: pydoc<5>. * dis: dis<3>. * dbm: dbm<6>. * ctypes: ctypes<2>. * site: site<2>. * sysconfig: sysconfig<2>. * pdb: pdb<5>. * configparser: configparser<2>. * urllib.parse: urllib parse<2>. * mailbox:: * turtledemo:: What’s New In Python 3.1 * PEP 372; Ordered Dictionaries: PEP 372 Ordered Dictionaries. * PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator. * Other Language Changes: Other Language Changes<8>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<2>. * Optimizations: Optimizations<7>. * IDLE: IDLE<2>. * Build and C API Changes: Build and C API Changes<6>. * Porting to Python 3.1: Porting to Python 3 1. What’s New In Python 3.0 * Common Stumbling Blocks:: * Overview Of Syntax Changes:: * Changes Already Present In Python 2.6: Changes Already Present In Python 2 6. * Library Changes:: * PEP 3101; A New Approach To String Formatting: PEP 3101 A New Approach To String Formatting. * Changes To Exceptions:: * Miscellaneous Other Changes:: * Build and C API Changes: Build and C API Changes<7>. * Performance:: * Porting To Python 3.0: Porting To Python 3 0. Common Stumbling Blocks * Print Is A Function:: * Views And Iterators Instead Of Lists:: * Ordering Comparisons:: * Integers:: * Text Vs. Data Instead Of Unicode Vs. 8-bit: Text Vs Data Instead Of Unicode Vs 8-bit. Overview Of Syntax Changes * New Syntax:: * Changed Syntax:: * Removed Syntax:: Miscellaneous Other Changes * Operators And Special Methods:: * Builtins:: What’s New in Python 2.7 * The Future for Python 2.x: The Future for Python 2 x. * Changes to the Handling of Deprecation Warnings:: * Python 3.1 Features: Python 3 1 Features. * PEP 372; Adding an Ordered Dictionary to collections: PEP 372 Adding an Ordered Dictionary to collections. * PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator<2>. * PEP 389; The argparse Module for Parsing Command Lines: PEP 389 The argparse Module for Parsing Command Lines. * PEP 391; Dictionary-Based Configuration For Logging: PEP 391 Dictionary-Based Configuration For Logging. * PEP 3106; Dictionary Views: PEP 3106 Dictionary Views. * PEP 3137; The memoryview Object: PEP 3137 The memoryview Object. * Other Language Changes: Other Language Changes<9>. * New and Improved Modules:: * Build and C API Changes: Build and C API Changes<8>. * Other Changes and Fixes:: * Porting to Python 2.7: Porting to Python 2 7. * New Features Added to Python 2.7 Maintenance Releases: New Features Added to Python 2 7 Maintenance Releases. * Acknowledgements:: Other Language Changes * Interpreter Changes:: * Optimizations: Optimizations<8>. New and Improved Modules * New module; importlib: New module importlib. * New module; sysconfig: New module sysconfig. * ttk; Themed Widgets for Tk: ttk Themed Widgets for Tk. * Updated module; unittest: Updated module unittest. * Updated module; ElementTree 1.3: Updated module ElementTree 1 3. Build and C API Changes * Capsules:: * Port-Specific Changes; Windows: Port-Specific Changes Windows. * Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X. * Port-Specific Changes; FreeBSD: Port-Specific Changes FreeBSD. New Features Added to Python 2.7 Maintenance Releases * Two new environment variables for debug mode:: * PEP 434; IDLE Enhancement Exception for All Branches: PEP 434 IDLE Enhancement Exception for All Branches. * PEP 466; Network Security Enhancements for Python 2.7: PEP 466 Network Security Enhancements for Python 2 7. * PEP 477; Backport ensurepip (PEP 453) to Python 2.7: PEP 477 Backport ensurepip PEP 453 to Python 2 7. * PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients<2>. * PEP 493; HTTPS verification migration tools for Python 2.7: PEP 493 HTTPS verification migration tools for Python 2 7. * New make regen-all build target: New make regen-all build target<3>. * Removal of make touch build target: Removal of make touch build target<3>. PEP 477: Backport ensurepip (PEP 453) to Python 2.7 * Bootstrapping pip By Default: Bootstrapping pip By Default<2>. * Documentation Changes: Documentation Changes<2>. What’s New in Python 2.6 * Python 3.0: Python 3 0. * Changes to the Development Process:: * PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement. * PEP 366; Explicit Relative Imports From a Main Module: PEP 366 Explicit Relative Imports From a Main Module. * PEP 370; Per-user site-packages Directory: PEP 370 Per-user site-packages Directory. * PEP 371; The multiprocessing Package: PEP 371 The multiprocessing Package. * PEP 3101; Advanced String Formatting: PEP 3101 Advanced String Formatting. * PEP 3105; print As a Function: PEP 3105 print As a Function. * PEP 3110; Exception-Handling Changes: PEP 3110 Exception-Handling Changes. * PEP 3112; Byte Literals: PEP 3112 Byte Literals. * PEP 3116; New I/O Library: PEP 3116 New I/O Library. * PEP 3118; Revised Buffer Protocol: PEP 3118 Revised Buffer Protocol. * PEP 3119; Abstract Base Classes: PEP 3119 Abstract Base Classes. * PEP 3127; Integer Literal Support and Syntax: PEP 3127 Integer Literal Support and Syntax. * PEP 3129; Class Decorators: PEP 3129 Class Decorators. * PEP 3141; A Type Hierarchy for Numbers: PEP 3141 A Type Hierarchy for Numbers. * Other Language Changes: Other Language Changes<10>. * New and Improved Modules: New and Improved Modules<2>. * Deprecations and Removals:: * Build and C API Changes: Build and C API Changes<9>. * Porting to Python 2.6: Porting to Python 2 6. * Acknowledgements: Acknowledgements<2>. Changes to the Development Process * New Issue Tracker; Roundup: New Issue Tracker Roundup. * New Documentation Format; reStructuredText Using Sphinx: New Documentation Format reStructuredText Using Sphinx. PEP 343: The ‘with’ statement * Writing Context Managers:: * The contextlib module:: PEP 3141: A Type Hierarchy for Numbers * The fractions Module:: Other Language Changes * Optimizations: Optimizations<9>. * Interpreter Changes: Interpreter Changes<2>. New and Improved Modules * The ast module:: * The future_builtins module:: * The json module; JavaScript Object Notation: The json module JavaScript Object Notation. * The plistlib module; A Property-List Parser: The plistlib module A Property-List Parser. * ctypes Enhancements:: * Improved SSL Support:: Build and C API Changes * Port-Specific Changes; Windows: Port-Specific Changes Windows<2>. * Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X<2>. * Port-Specific Changes; IRIX: Port-Specific Changes IRIX. What’s New in Python 2.5 * PEP 308; Conditional Expressions: PEP 308 Conditional Expressions. * PEP 309; Partial Function Application: PEP 309 Partial Function Application. * PEP 314; Metadata for Python Software Packages v1.1: PEP 314 Metadata for Python Software Packages v1 1. * PEP 328; Absolute and Relative Imports: PEP 328 Absolute and Relative Imports. * PEP 338; Executing Modules as Scripts: PEP 338 Executing Modules as Scripts. * PEP 341; Unified try/except/finally: PEP 341 Unified try/except/finally. * PEP 342; New Generator Features: PEP 342 New Generator Features. * PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement<2>. * PEP 352; Exceptions as New-Style Classes: PEP 352 Exceptions as New-Style Classes. * PEP 353; Using ssize_t as the index type: PEP 353 Using ssize_t as the index type. * PEP 357; The ‘__index__’ method: PEP 357 The ‘__index__’ method. * Other Language Changes: Other Language Changes<11>. * New, Improved, and Removed Modules: New Improved and Removed Modules. * Build and C API Changes: Build and C API Changes<10>. * Porting to Python 2.5: Porting to Python 2 5. * Acknowledgements: Acknowledgements<3>. PEP 343: The ‘with’ statement * Writing Context Managers: Writing Context Managers<2>. * The contextlib module: The contextlib module<2>. Other Language Changes * Interactive Interpreter Changes:: * Optimizations: Optimizations<10>. New, Improved, and Removed Modules * The ctypes package:: * The ElementTree package:: * The hashlib package:: * The sqlite3 package:: * The wsgiref package:: Build and C API Changes * Port-Specific Changes:: What’s New in Python 2.4 * PEP 218; Built-In Set Objects: PEP 218 Built-In Set Objects. * PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers. * PEP 289; Generator Expressions: PEP 289 Generator Expressions. * PEP 292; Simpler String Substitutions: PEP 292 Simpler String Substitutions. * PEP 318; Decorators for Functions and Methods: PEP 318 Decorators for Functions and Methods. * PEP 322; Reverse Iteration: PEP 322 Reverse Iteration. * PEP 324; New subprocess Module: PEP 324 New subprocess Module. * PEP 327; Decimal Data Type: PEP 327 Decimal Data Type. * PEP 328; Multi-line Imports: PEP 328 Multi-line Imports. * PEP 331; Locale-Independent Float/String Conversions: PEP 331 Locale-Independent Float/String Conversions. * Other Language Changes: Other Language Changes<12>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<3>. * Build and C API Changes: Build and C API Changes<11>. * Porting to Python 2.4: Porting to Python 2 4. * Acknowledgements: Acknowledgements<4>. PEP 327: Decimal Data Type * Why is Decimal needed?:: * The Decimal type:: * The Context type:: Other Language Changes * Optimizations: Optimizations<11>. New, Improved, and Deprecated Modules * cookielib:: * doctest: doctest<3>. Build and C API Changes * Port-Specific Changes: Port-Specific Changes<2>. What’s New in Python 2.3 * PEP 218; A Standard Set Datatype: PEP 218 A Standard Set Datatype. * PEP 255; Simple Generators: PEP 255 Simple Generators. * PEP 263; Source Code Encodings: PEP 263 Source Code Encodings. * PEP 273; Importing Modules from ZIP Archives: PEP 273 Importing Modules from ZIP Archives. * PEP 277; Unicode file name support for Windows NT: PEP 277 Unicode file name support for Windows NT. * PEP 278; Universal Newline Support: PEP 278 Universal Newline Support. * PEP 279; enumerate(): PEP 279 enumerate. * PEP 282; The logging Package: PEP 282 The logging Package. * PEP 285; A Boolean Type: PEP 285 A Boolean Type. * PEP 293; Codec Error Handling Callbacks: PEP 293 Codec Error Handling Callbacks. * PEP 301; Package Index and Metadata for Distutils: PEP 301 Package Index and Metadata for Distutils. * PEP 302; New Import Hooks: PEP 302 New Import Hooks. * PEP 305; Comma-separated Files: PEP 305 Comma-separated Files. * PEP 307; Pickle Enhancements: PEP 307 Pickle Enhancements. * Extended Slices:: * Other Language Changes: Other Language Changes<13>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<4>. * Pymalloc; A Specialized Object Allocator: Pymalloc A Specialized Object Allocator. * Build and C API Changes: Build and C API Changes<12>. * Other Changes and Fixes: Other Changes and Fixes<2>. * Porting to Python 2.3: Porting to Python 2 3. * Acknowledgements: Acknowledgements<5>. Other Language Changes * String Changes:: * Optimizations: Optimizations<12>. New, Improved, and Deprecated Modules * Date/Time Type:: * The optparse Module:: Build and C API Changes * Port-Specific Changes: Port-Specific Changes<3>. What’s New in Python 2.2 * Introduction:: * PEPs 252 and 253; Type and Class Changes: PEPs 252 and 253 Type and Class Changes. * PEP 234; Iterators: PEP 234 Iterators. * PEP 255; Simple Generators: PEP 255 Simple Generators<2>. * PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers<2>. * PEP 238; Changing the Division Operator: PEP 238 Changing the Division Operator. * Unicode Changes:: * PEP 227; Nested Scopes: PEP 227 Nested Scopes. * New and Improved Modules: New and Improved Modules<3>. * Interpreter Changes and Fixes:: * Other Changes and Fixes: Other Changes and Fixes<3>. * Acknowledgements: Acknowledgements<6>. PEPs 252 and 253: Type and Class Changes * Old and New Classes:: * Descriptors:: * Multiple Inheritance; The Diamond Rule: Multiple Inheritance The Diamond Rule. * Attribute Access:: * Related Links:: What’s New in Python 2.1 * Introduction: Introduction<2>. * PEP 227; Nested Scopes: PEP 227 Nested Scopes<2>. * PEP 236; __future__ Directives: PEP 236 __future__ Directives. * PEP 207; Rich Comparisons: PEP 207 Rich Comparisons. * PEP 230; Warning Framework: PEP 230 Warning Framework. * PEP 229; New Build System: PEP 229 New Build System. * PEP 205; Weak References: PEP 205 Weak References. * PEP 232; Function Attributes: PEP 232 Function Attributes. * PEP 235; Importing Modules on Case-Insensitive Platforms: PEP 235 Importing Modules on Case-Insensitive Platforms. * PEP 217; Interactive Display Hook: PEP 217 Interactive Display Hook. * PEP 208; New Coercion Model: PEP 208 New Coercion Model. * PEP 241; Metadata in Python Packages: PEP 241 Metadata in Python Packages. * New and Improved Modules: New and Improved Modules<4>. * Other Changes and Fixes: Other Changes and Fixes<4>. * Acknowledgements: Acknowledgements<7>. What’s New in Python 2.0 * Introduction: Introduction<3>. * What About Python 1.6?: What About Python 1 6?. * New Development Process:: * Unicode: Unicode<2>. * List Comprehensions:: * Augmented Assignment:: * String Methods:: * Garbage Collection of Cycles:: * Other Core Changes:: * Porting to 2.0: Porting to 2 0. * Extending/Embedding Changes:: * Distutils; Making Modules Easy to Install: Distutils Making Modules Easy to Install. * XML Modules:: * Module changes:: * New modules:: * IDLE Improvements:: * Deleted and Deprecated Modules:: * Acknowledgements: Acknowledgements<8>. Other Core Changes * Minor Language Changes:: * Changes to Built-in Functions:: XML Modules * SAX2 Support:: * DOM Support:: * Relationship to PyXML:: The Python Tutorial * Whetting Your Appetite:: * Using the Python Interpreter:: * An Informal Introduction to Python:: * More Control Flow Tools:: * Data Structures:: * Modules:: * Input and Output:: * Errors and Exceptions:: * Classes:: * Brief Tour of the Standard Library:: * Brief Tour of the Standard Library — Part II:: * Virtual Environments and Packages:: * What Now?:: * Interactive Input Editing and History Substitution:: * Floating Point Arithmetic; Issues and Limitations: Floating Point Arithmetic Issues and Limitations. * Appendix:: Using the Python Interpreter * Invoking the Interpreter:: * The Interpreter and Its Environment:: Invoking the Interpreter * Argument Passing:: * Interactive Mode:: The Interpreter and Its Environment * Source Code Encoding:: An Informal Introduction to Python * Using Python as a Calculator:: * First Steps Towards Programming:: Using Python as a Calculator * Numbers:: * Strings:: * Lists:: More Control Flow Tools * if Statements:: * for Statements:: * The range() Function: The range Function. * break and continue Statements, and else Clauses on Loops: break and continue Statements and else Clauses on Loops. * pass Statements:: * Defining Functions:: * More on Defining Functions:: * Intermezzo; Coding Style: Intermezzo Coding Style. More on Defining Functions * Default Argument Values:: * Keyword Arguments:: * Special parameters:: * Arbitrary Argument Lists:: * Unpacking Argument Lists:: * Lambda Expressions:: * Documentation Strings:: * Function Annotations:: Special parameters * Positional-or-Keyword Arguments:: * Positional-Only Parameters:: * Keyword-Only Arguments:: * Function Examples:: * Recap:: Data Structures * More on Lists:: * The del statement:: * Tuples and Sequences:: * Sets:: * Dictionaries:: * Looping Techniques:: * More on Conditions:: * Comparing Sequences and Other Types:: More on Lists * Using Lists as Stacks:: * Using Lists as Queues:: * List Comprehensions: List Comprehensions<2>. * Nested List Comprehensions:: Modules * More on Modules:: * Standard Modules:: * The dir() Function: The dir Function. * Packages:: More on Modules * Executing modules as scripts:: * The Module Search Path:: * “Compiled” Python files:: Packages * Importing * From a Package:: * Intra-package References:: * Packages in Multiple Directories:: Input and Output * Fancier Output Formatting:: * Reading and Writing Files:: Fancier Output Formatting * Formatted String Literals:: * The String format() Method: The String format Method. * Manual String Formatting:: * Old string formatting:: Reading and Writing Files * Methods of File Objects:: * Saving structured data with json:: Errors and Exceptions * Syntax Errors:: * Exceptions:: * Handling Exceptions:: * Raising Exceptions:: * User-defined Exceptions:: * Defining Clean-up Actions:: * Predefined Clean-up Actions:: Classes * A Word About Names and Objects:: * Python Scopes and Namespaces:: * A First Look at Classes:: * Random Remarks:: * Inheritance:: * Private Variables:: * Odds and Ends:: * Iterators:: * Generators:: * Generator Expressions:: Python Scopes and Namespaces * Scopes and Namespaces Example:: A First Look at Classes * Class Definition Syntax:: * Class Objects:: * Instance Objects:: * Method Objects:: * Class and Instance Variables:: Inheritance * Multiple Inheritance:: Brief Tour of the Standard Library * Operating System Interface:: * File Wildcards:: * Command Line Arguments:: * Error Output Redirection and Program Termination:: * String Pattern Matching:: * Mathematics:: * Internet Access:: * Dates and Times:: * Data Compression:: * Performance Measurement:: * Quality Control:: * Batteries Included:: Brief Tour of the Standard Library — Part II * Output Formatting:: * Templating:: * Working with Binary Data Record Layouts:: * Multi-threading: Multi-threading<2>. * Logging:: * Weak References:: * Tools for Working with Lists:: * Decimal Floating Point Arithmetic:: Virtual Environments and Packages * Introduction: Introduction<4>. * Creating Virtual Environments:: * Managing Packages with pip:: Interactive Input Editing and History Substitution * Tab Completion and History Editing:: * Alternatives to the Interactive Interpreter:: Floating Point Arithmetic: Issues and Limitations * Representation Error:: Appendix * Interactive Mode: Interactive Mode<2>. Interactive Mode * Error Handling:: * Executable Python Scripts:: * The Interactive Startup File:: * The Customization Modules:: Python Setup and Usage * Command line and environment:: * Using Python on Unix platforms:: * Using Python on Windows:: * Using Python on a Macintosh:: * Editors and IDEs:: Command line and environment * Command line:: * Environment variables:: Command line * Interface options:: * Generic options:: * Miscellaneous options:: * Options you shouldn’t use:: Environment variables * Debug-mode variables:: Using Python on Unix platforms * Getting and installing the latest version of Python:: * Building Python:: * Python-related paths and files:: * Miscellaneous:: Getting and installing the latest version of Python * On Linux:: * On FreeBSD and OpenBSD:: * On OpenSolaris:: Using Python on Windows * The full installer:: * The Microsoft Store package:: * The nuget.org packages: The nuget org packages. * The embeddable package:: * Alternative bundles:: * Configuring Python:: * UTF-8 mode:: * Python Launcher for Windows:: * Finding modules:: * Additional modules:: * Compiling Python on Windows:: * Other Platforms:: The full installer * Installation steps:: * Removing the MAX_PATH Limitation:: * Installing Without UI:: * Installing Without Downloading:: * Modifying an install:: The Microsoft Store package * Known Issues:: The embeddable package * Python Application:: * Embedding Python:: Configuring Python * Excursus; Setting environment variables: Excursus Setting environment variables. * Finding the Python executable:: Python Launcher for Windows * Getting started:: * Shebang Lines:: * Arguments in shebang lines:: * Customization:: * Diagnostics:: Getting started * From the command-line:: * Virtual environments:: * From a script:: * From file associations:: Customization * Customization via INI files:: * Customizing default Python versions:: Additional modules * PyWin32:: * cx_Freeze:: * WConio:: Using Python on a Macintosh * Getting and Installing MacPython:: * The IDE:: * Installing Additional Python Packages:: * GUI Programming on the Mac:: * Distributing Python Applications on the Mac:: * Other Resources:: Getting and Installing MacPython * How to run a Python script:: * Running scripts with a GUI:: * Configuration:: The Python Language Reference * Introduction: Introduction<5>. * Lexical analysis:: * Data model:: * Execution model:: * The import system:: * Expressions:: * Simple statements:: * Compound statements:: * Top-level components:: * Full Grammar specification:: Introduction * Alternate Implementations:: * Notation:: Lexical analysis * Line structure:: * Other tokens:: * Identifiers and keywords:: * Literals:: * Operators:: * Delimiters:: Line structure * Logical lines:: * Physical lines:: * Comments:: * Encoding declarations:: * Explicit line joining:: * Implicit line joining:: * Blank lines:: * Indentation:: * Whitespace between tokens:: Identifiers and keywords * Keywords:: * Reserved classes of identifiers:: Literals * String and Bytes literals:: * String literal concatenation:: * Formatted string literals:: * Numeric literals:: * Integer literals:: * Floating point literals:: * Imaginary literals:: Data model * Objects, values and types: Objects values and types. * The standard type hierarchy:: * Special method names:: * Coroutines:: Special method names * Basic customization:: * Customizing attribute access:: * Customizing class creation:: * Customizing instance and subclass checks:: * Emulating generic types:: * Emulating callable objects:: * Emulating container types:: * Emulating numeric types:: * With Statement Context Managers:: * Special method lookup:: Customizing attribute access * Customizing module attribute access:: * Implementing Descriptors:: * Invoking Descriptors:: * __slots__:: __slots__ * Notes on using __slots__:: Customizing class creation * Metaclasses:: * Resolving MRO entries:: * Determining the appropriate metaclass:: * Preparing the class namespace:: * Executing the class body:: * Creating the class object:: * Uses for metaclasses:: Coroutines * Awaitable Objects:: * Coroutine Objects:: * Asynchronous Iterators:: * Asynchronous Context Managers:: Execution model * Structure of a program:: * Naming and binding:: * Exceptions: Exceptions<2>. Naming and binding * Binding of names:: * Resolution of names:: * Builtins and restricted execution:: * Interaction with dynamic features:: The import system * importlib: importlib<7>. * Packages: Packages<2>. * Searching:: * Loading:: * The Path Based Finder:: * Replacing the standard import system:: * Package Relative Imports:: * Special considerations for __main__:: * Open issues:: * References:: Packages * Regular packages:: * Namespace packages:: Searching * The module cache:: * Finders and loaders:: * Import hooks:: * The meta path:: Loading * Loaders:: * Submodules:: * Module spec:: * Import-related module attributes:: * module.__path__: module __path__. * Module reprs:: * Cached bytecode invalidation:: The Path Based Finder * Path entry finders:: * Path entry finder protocol:: Special considerations for __main__ * __main__.__spec__: __main__ __spec__. Expressions * Arithmetic conversions:: * Atoms:: * Primaries:: * Await expression:: * The power operator:: * Unary arithmetic and bitwise operations:: * Binary arithmetic operations:: * Shifting operations:: * Binary bitwise operations:: * Comparisons:: * Boolean operations:: * Assignment expressions: Assignment expressions<2>. * Conditional expressions:: * Lambdas:: * Expression lists:: * Evaluation order:: * Operator precedence:: Atoms * Identifiers (Names): Identifiers Names. * Literals: Literals<2>. * Parenthesized forms:: * Displays for lists, sets and dictionaries: Displays for lists sets and dictionaries. * List displays:: * Set displays:: * Dictionary displays:: * Generator expressions:: * Yield expressions:: Yield expressions * Generator-iterator methods:: * Examples:: * Asynchronous generator functions:: * Asynchronous generator-iterator methods:: Primaries * Attribute references:: * Subscriptions:: * Slicings:: * Calls:: Comparisons * Value comparisons:: * Membership test operations:: * Identity comparisons:: Simple statements * Expression statements:: * Assignment statements:: * The assert statement:: * The pass statement:: * The del statement: The del statement<2>. * The return statement:: * The yield statement:: * The raise statement:: * The break statement:: * The continue statement:: * The import statement:: * The global statement:: * The nonlocal statement:: Assignment statements * Augmented assignment statements:: * Annotated assignment statements:: The import statement * Future statements:: Compound statements * The if statement:: * The while statement:: * The for statement:: * The try statement:: * The with statement:: * Function definitions:: * Class definitions:: * Coroutines: Coroutines<2>. Coroutines * Coroutine function definition:: * The async for statement:: * The async with statement:: Top-level components * Complete Python programs:: * File input:: * Interactive input:: * Expression input:: The Python Standard Library * Introduction: Introduction<6>. * Built-in Functions:: * Built-in Constants:: * Built-in Types:: * Built-in Exceptions:: * Text Processing Services:: * Binary Data Services:: * Data Types:: * Numeric and Mathematical Modules:: * Functional Programming Modules:: * File and Directory Access:: * Data Persistence:: * Data Compression and Archiving:: * File Formats:: * Cryptographic Services:: * Generic Operating System Services:: * Concurrent Execution:: * Networking and Interprocess Communication:: * Internet Data Handling:: * Structured Markup Processing Tools:: * Internet Protocols and Support:: * Multimedia Services:: * Internationalization:: * Program Frameworks:: * Graphical User Interfaces with Tk:: * Development Tools:: * Debugging and Profiling:: * Software Packaging and Distribution:: * Python Runtime Services:: * Custom Python Interpreters:: * Importing Modules:: * Python Language Services:: * Miscellaneous Services:: * MS Windows Specific Services:: * Unix Specific Services:: * Superseded Modules:: * Undocumented Modules:: Introduction * Notes on availability:: Built-in Constants * Constants added by the site module:: Built-in Types * Truth Value Testing:: * Boolean Operations — and, or, not: Boolean Operations — and or not. * Comparisons: Comparisons<2>. * Numeric Types — int, float, complex: Numeric Types — int float complex. * Iterator Types:: * Sequence Types — list, tuple, range: Sequence Types — list tuple range. * Text Sequence Type — str:: * Binary Sequence Types — bytes, bytearray, memoryview: Binary Sequence Types — bytes bytearray memoryview. * Set Types — set, frozenset: Set Types — set frozenset. * Mapping Types — dict:: * Context Manager Types:: * Other Built-in Types:: * Special Attributes:: Numeric Types — int, float, complex * Bitwise Operations on Integer Types:: * Additional Methods on Integer Types:: * Additional Methods on Float:: * Hashing of numeric types:: Iterator Types * Generator Types:: Sequence Types — list, tuple, range * Common Sequence Operations:: * Immutable Sequence Types:: * Mutable Sequence Types:: * Lists: Lists<2>. * Tuples:: * Ranges:: Text Sequence Type — str * String Methods: String Methods<2>. * printf-style String Formatting:: Binary Sequence Types — bytes, bytearray, memoryview * Bytes Objects:: * Bytearray Objects:: * Bytes and Bytearray Operations:: * printf-style Bytes Formatting:: * Memory Views:: Mapping Types — dict * Dictionary view objects:: Other Built-in Types * Modules: Modules<2>. * Classes and Class Instances:: * Functions:: * Methods:: * Code Objects:: * Type Objects:: * The Null Object:: * The Ellipsis Object:: * The NotImplemented Object:: * Boolean Values:: * Internal Objects:: Built-in Exceptions * Base classes:: * Concrete exceptions:: * Warnings:: * Exception hierarchy:: Concrete exceptions * OS exceptions:: Text Processing Services * string — Common string operations:: * re — Regular expression operations:: * difflib — Helpers for computing deltas:: * textwrap — Text wrapping and filling:: * unicodedata — Unicode Database:: * stringprep — Internet String Preparation:: * readline — GNU readline interface:: * rlcompleter — Completion function for GNU readline:: string — Common string operations * String constants:: * Custom String Formatting:: * Format String Syntax:: * Template strings:: * Helper functions:: Format String Syntax * Format Specification Mini-Language:: * Format examples:: re — Regular expression operations * Regular Expression Syntax:: * Module Contents:: * Regular Expression Objects:: * Match Objects:: * Regular Expression Examples:: Regular Expression Examples * Checking for a Pair:: * Simulating scanf(): Simulating scanf. * search() vs. match(): search vs match. * Making a Phonebook:: * Text Munging:: * Finding all Adverbs:: * Finding all Adverbs and their Positions:: * Raw String Notation:: * Writing a Tokenizer:: difflib — Helpers for computing deltas * SequenceMatcher Objects:: * SequenceMatcher Examples:: * Differ Objects:: * Differ Example:: * A command-line interface to difflib:: readline — GNU readline interface * Init file:: * Line buffer:: * History file:: * History list:: * Startup hooks:: * Completion:: * Example:: rlcompleter — Completion function for GNU readline * Completer Objects:: Binary Data Services * struct — Interpret bytes as packed binary data:: * codecs — Codec registry and base classes:: struct — Interpret bytes as packed binary data * Functions and Exceptions:: * Format Strings:: * Classes: Classes<2>. Format Strings * Byte Order, Size, and Alignment: Byte Order Size and Alignment. * Format Characters:: * Examples: Examples<2>. codecs — Codec registry and base classes * Codec Base Classes:: * Encodings and Unicode:: * Standard Encodings:: * Python Specific Encodings:: * encodings.idna — Internationalized Domain Names in Applications: encodings idna — Internationalized Domain Names in Applications. * encodings.mbcs — Windows ANSI codepage: encodings mbcs — Windows ANSI codepage. * encodings.utf_8_sig — UTF-8 codec with BOM signature: encodings utf_8_sig — UTF-8 codec with BOM signature. Codec Base Classes * Error Handlers:: * Stateless Encoding and Decoding:: * Incremental Encoding and Decoding:: * Stream Encoding and Decoding:: Incremental Encoding and Decoding * IncrementalEncoder Objects:: * IncrementalDecoder Objects:: Stream Encoding and Decoding * StreamWriter Objects:: * StreamReader Objects:: * StreamReaderWriter Objects:: * StreamRecoder Objects:: Python Specific Encodings * Text Encodings:: * Binary Transforms:: * Text Transforms:: Data Types * datetime — Basic date and time types:: * calendar — General calendar-related functions:: * collections — Container datatypes:: * collections.abc — Abstract Base Classes for Containers: collections abc — Abstract Base Classes for Containers. * heapq — Heap queue algorithm:: * bisect — Array bisection algorithm:: * array — Efficient arrays of numeric values:: * weakref — Weak references:: * types — Dynamic type creation and names for built-in types:: * copy — Shallow and deep copy operations:: * pprint — Data pretty printer:: * reprlib — Alternate repr() implementation: reprlib — Alternate repr implementation. * enum — Support for enumerations:: datetime — Basic date and time types * Aware and Naive Objects:: * Constants:: * Available Types:: * timedelta Objects:: * date Objects:: * datetime Objects:: * time Objects:: * tzinfo Objects:: * timezone Objects:: * strftime() and strptime() Behavior: strftime and strptime Behavior. Available Types * Common Properties:: * Determining if an Object is Aware or Naive:: timedelta Objects * Examples of usage; timedelta: Examples of usage timedelta. date Objects * Examples of Usage; date: Examples of Usage date. datetime Objects * Examples of Usage; datetime: Examples of Usage datetime. time Objects * Examples of Usage; time: Examples of Usage time. strftime() and strptime() Behavior * strftime() and strptime() Format Codes: strftime and strptime Format Codes. * Technical Detail:: collections — Container datatypes * ChainMap objects:: * Counter objects:: * deque objects:: * defaultdict objects:: * namedtuple() Factory Function for Tuples with Named Fields: namedtuple Factory Function for Tuples with Named Fields. * OrderedDict objects:: * UserDict objects:: * UserList objects:: * UserString objects:: ChainMap objects * ChainMap Examples and Recipes:: deque objects * deque Recipes:: defaultdict objects * defaultdict Examples:: OrderedDict objects * OrderedDict Examples and Recipes:: collections.abc — Abstract Base Classes for Containers * Collections Abstract Base Classes:: heapq — Heap queue algorithm * Basic Examples:: * Priority Queue Implementation Notes:: * Theory:: bisect — Array bisection algorithm * Searching Sorted Lists:: * Other Examples:: weakref — Weak references * Weak Reference Objects:: * Example: Example<2>. * Finalizer Objects:: * Comparing finalizers with __del__() methods: Comparing finalizers with __del__ methods. types — Dynamic type creation and names for built-in types * Dynamic Type Creation:: * Standard Interpreter Types:: * Additional Utility Classes and Functions:: * Coroutine Utility Functions:: pprint — Data pretty printer * PrettyPrinter Objects:: * Example: Example<3>. reprlib — Alternate repr() implementation * Repr Objects:: * Subclassing Repr Objects:: enum — Support for enumerations * Module Contents: Module Contents<2>. * Creating an Enum:: * Programmatic access to enumeration members and their attributes:: * Duplicating enum members and values:: * Ensuring unique enumeration values:: * Using automatic values:: * Iteration:: * Comparisons: Comparisons<3>. * Allowed members and attributes of enumerations:: * Restricted Enum subclassing:: * Pickling:: * Functional API:: * Derived Enumerations:: * When to use __new__() vs. __init__(): When to use __new__ vs __init__. * Interesting examples:: * How are Enums different?:: Derived Enumerations * IntEnum:: * IntFlag:: * Flag:: * Others:: Interesting examples * Omitting values:: * OrderedEnum:: * DuplicateFreeEnum:: * Planet:: * TimePeriod:: Omitting values * Using auto:: * Using object:: * Using a descriptive string:: * Using a custom __new__(): Using a custom __new__. How are Enums different? * Enum Classes:: * Enum Members (aka instances): Enum Members aka instances. * Finer Points:: Finer Points * Supported __dunder__ names:: * Supported _sunder_ names:: * Enum member type:: * Boolean value of Enum classes and members:: * Enum classes with methods:: * Combining members of Flag:: Numeric and Mathematical Modules * numbers — Numeric abstract base classes:: * math — Mathematical functions:: * cmath — Mathematical functions for complex numbers:: * decimal — Decimal fixed point and floating point arithmetic:: * fractions — Rational numbers:: * random — Generate pseudo-random numbers:: * statistics — Mathematical statistics functions:: numbers — Numeric abstract base classes * The numeric tower:: * Notes for type implementors:: Notes for type implementors * Adding More Numeric ABCs:: * Implementing the arithmetic operations:: math — Mathematical functions * Number-theoretic and representation functions:: * Power and logarithmic functions:: * Trigonometric functions:: * Angular conversion:: * Hyperbolic functions:: * Special functions:: * Constants: Constants<2>. cmath — Mathematical functions for complex numbers * Conversions to and from polar coordinates:: * Power and logarithmic functions: Power and logarithmic functions<2>. * Trigonometric functions: Trigonometric functions<2>. * Hyperbolic functions: Hyperbolic functions<2>. * Classification functions:: * Constants: Constants<3>. decimal — Decimal fixed point and floating point arithmetic * Quick-start Tutorial:: * Decimal objects:: * Context objects:: * Constants: Constants<4>. * Rounding modes:: * Signals:: * Floating Point Notes:: * Working with threads:: * Recipes:: * Decimal FAQ:: Decimal objects * Logical operands:: Floating Point Notes * Mitigating round-off error with increased precision:: * Special values:: random — Generate pseudo-random numbers * Bookkeeping functions:: * Functions for integers:: * Functions for sequences:: * Real-valued distributions:: * Alternative Generator:: * Notes on Reproducibility:: * Examples and Recipes:: statistics — Mathematical statistics functions * Averages and measures of central location:: * Measures of spread:: * Function details:: * Exceptions: Exceptions<3>. * NormalDist objects:: NormalDist objects * NormalDist Examples and Recipes:: Functional Programming Modules * itertools — Functions creating iterators for efficient looping:: * functools — Higher-order functions and operations on callable objects:: * operator — Standard operators as functions:: itertools — Functions creating iterators for efficient looping * Itertool functions:: * Itertools Recipes:: functools — Higher-order functions and operations on callable objects * partial Objects:: operator — Standard operators as functions * Mapping Operators to Functions:: * In-place Operators:: File and Directory Access * pathlib — Object-oriented filesystem paths:: * os.path — Common pathname manipulations: os path — Common pathname manipulations. * fileinput — Iterate over lines from multiple input streams:: * stat — Interpreting stat() results: stat — Interpreting stat results. * filecmp — File and Directory Comparisons:: * tempfile — Generate temporary files and directories:: * glob — Unix style pathname pattern expansion:: * fnmatch — Unix filename pattern matching:: * linecache — Random access to text lines:: * shutil — High-level file operations:: pathlib — Object-oriented filesystem paths * Basic use:: * Pure paths:: * Concrete paths:: * Correspondence to tools in the os module:: Pure paths * General properties:: * Operators: Operators<2>. * Accessing individual parts:: * Methods and properties:: Concrete paths * Methods: Methods<2>. filecmp — File and Directory Comparisons * The dircmp class:: tempfile — Generate temporary files and directories * Examples: Examples<3>. * Deprecated functions and variables:: shutil — High-level file operations * Directory and files operations:: * Archiving operations:: * Querying the size of the output terminal:: Directory and files operations * Platform-dependent efficient copy operations:: * copytree example:: * rmtree example:: Archiving operations * Archiving example:: * Archiving example with base_dir:: Data Persistence * pickle — Python object serialization:: * copyreg — Register pickle support functions:: * shelve — Python object persistence:: * marshal — Internal Python object serialization:: * dbm — Interfaces to Unix “databases”:: * sqlite3 — DB-API 2.0 interface for SQLite databases: sqlite3 — DB-API 2 0 interface for SQLite databases. pickle — Python object serialization * Relationship to other Python modules:: * Data stream format:: * Module Interface:: * What can be pickled and unpickled?:: * Pickling Class Instances:: * Custom Reduction for Types, Functions, and Other Objects: Custom Reduction for Types Functions and Other Objects. * Out-of-band Buffers:: * Restricting Globals:: * Performance: Performance<2>. * Examples: Examples<4>. Relationship to other Python modules * Comparison with marshal:: * Comparison with json:: Pickling Class Instances * Persistence of External Objects:: * Dispatch Tables:: * Handling Stateful Objects:: Out-of-band Buffers * Provider API:: * Consumer API:: * Example: Example<4>. copyreg — Register pickle support functions * Example: Example<5>. shelve — Python object persistence * Restrictions:: * Example: Example<6>. dbm — Interfaces to Unix “databases” * dbm.gnu — GNU’s reinterpretation of dbm: dbm gnu — GNU’s reinterpretation of dbm. * dbm.ndbm — Interface based on ndbm: dbm ndbm — Interface based on ndbm. * dbm.dumb — Portable DBM implementation: dbm dumb — Portable DBM implementation. sqlite3 — DB-API 2.0 interface for SQLite databases * Module functions and constants:: * Connection Objects:: * Cursor Objects:: * Row Objects:: * Exceptions: Exceptions<4>. * SQLite and Python types:: * Controlling Transactions:: * Using sqlite3 efficiently:: SQLite and Python types * Introduction: Introduction<7>. * Using adapters to store additional Python types in SQLite databases:: * Converting SQLite values to custom Python types:: * Default adapters and converters:: Using adapters to store additional Python types in SQLite databases * Letting your object adapt itself:: * Registering an adapter callable:: Using sqlite3 efficiently * Using shortcut methods:: * Accessing columns by name instead of by index:: * Using the connection as a context manager:: Data Compression and Archiving * zlib — Compression compatible with gzip:: * gzip — Support for gzip files:: * bz2 — Support for bzip2 compression:: * lzma — Compression using the LZMA algorithm:: * zipfile — Work with ZIP archives:: * tarfile — Read and write tar archive files:: gzip — Support for gzip files * Examples of usage:: * Command Line Interface:: Command Line Interface * Command line options:: bz2 — Support for bzip2 compression * (De)compression of files: De compression of files. * Incremental (de)compression: Incremental de compression. * One-shot (de)compression: One-shot de compression. * Examples of usage: Examples of usage<2>. lzma — Compression using the LZMA algorithm * Reading and writing compressed files:: * Compressing and decompressing data in memory:: * Miscellaneous: Miscellaneous<2>. * Specifying custom filter chains:: * Examples: Examples<5>. zipfile — Work with ZIP archives * ZipFile Objects:: * Path Objects:: * PyZipFile Objects:: * ZipInfo Objects:: * Command-Line Interface:: * Decompression pitfalls:: Command-Line Interface * Command-line options:: Decompression pitfalls * From file itself:: * File System limitations:: * Resources limitations:: * Interruption:: * Default behaviors of extraction:: tarfile — Read and write tar archive files * TarFile Objects:: * TarInfo Objects:: * Command-Line Interface: Command-Line Interface<2>. * Examples: Examples<6>. * Supported tar formats:: * Unicode issues:: Command-Line Interface * Command-line options: Command-line options<2>. File Formats * csv — CSV File Reading and Writing:: * configparser — Configuration file parser:: * netrc — netrc file processing:: * xdrlib — Encode and decode XDR data:: * plistlib — Generate and parse Mac OS X .plist files: plistlib — Generate and parse Mac OS X plist files. csv — CSV File Reading and Writing * Module Contents: Module Contents<3>. * Dialects and Formatting Parameters:: * Reader Objects:: * Writer Objects:: * Examples: Examples<7>. configparser — Configuration file parser * Quick Start:: * Supported Datatypes:: * Fallback Values:: * Supported INI File Structure:: * Interpolation of values:: * Mapping Protocol Access:: * Customizing Parser Behaviour:: * Legacy API Examples:: * ConfigParser Objects:: * RawConfigParser Objects:: * Exceptions: Exceptions<5>. netrc — netrc file processing * netrc Objects:: xdrlib — Encode and decode XDR data * Packer Objects:: * Unpacker Objects:: * Exceptions: Exceptions<6>. plistlib — Generate and parse Mac OS X .plist files * Examples: Examples<8>. Cryptographic Services * hashlib — Secure hashes and message digests:: * hmac — Keyed-Hashing for Message Authentication:: * secrets — Generate secure random numbers for managing secrets:: hashlib — Secure hashes and message digests * Hash algorithms:: * SHAKE variable length digests:: * Key derivation:: * BLAKE2:: BLAKE2 * Creating hash objects:: * Constants: Constants<5>. * Examples: Examples<9>. * Credits:: Examples * Simple hashing:: * Using different digest sizes:: * Keyed hashing:: * Randomized hashing:: * Personalization:: * Tree mode:: secrets — Generate secure random numbers for managing secrets * Random numbers:: * Generating tokens:: * Other functions:: * Recipes and best practices:: Generating tokens * How many bytes should tokens use?:: Generic Operating System Services * os — Miscellaneous operating system interfaces:: * io — Core tools for working with streams:: * time — Time access and conversions:: * argparse — Parser for command-line options, arguments and sub-commands: argparse — Parser for command-line options arguments and sub-commands. * getopt — C-style parser for command line options:: * logging — Logging facility for Python:: * logging.config — Logging configuration: logging config — Logging configuration. * logging.handlers — Logging handlers: logging handlers — Logging handlers. * getpass — Portable password input:: * curses — Terminal handling for character-cell displays:: * curses.textpad — Text input widget for curses programs: curses textpad — Text input widget for curses programs. * curses.ascii — Utilities for ASCII characters: curses ascii — Utilities for ASCII characters. * curses.panel — A panel stack extension for curses: curses panel — A panel stack extension for curses. * platform — Access to underlying platform’s identifying data:: * errno — Standard errno system symbols:: * ctypes — A foreign function library for Python:: os — Miscellaneous operating system interfaces * File Names, Command Line Arguments, and Environment Variables: File Names Command Line Arguments and Environment Variables. * Process Parameters:: * File Object Creation:: * File Descriptor Operations:: * Files and Directories:: * Process Management:: * Interface to the scheduler:: * Miscellaneous System Information:: * Random numbers: Random numbers<2>. File Descriptor Operations * Querying the size of a terminal:: * Inheritance of File Descriptors:: Files and Directories * Linux extended attributes:: io — Core tools for working with streams * Overview:: * High-level Module Interface:: * Class hierarchy:: * Performance: Performance<3>. Overview * Text I/O:: * Binary I/O:: * Raw I/O:: Class hierarchy * I/O Base Classes:: * Raw File I/O:: * Buffered Streams:: * Text I/O: Text I/O<2>. Performance * Binary I/O: Binary I/O<2>. * Text I/O: Text I/O<3>. * Multi-threading: Multi-threading<3>. * Reentrancy:: time — Time access and conversions * Functions: Functions<2>. * Clock ID Constants:: * Timezone Constants:: argparse — Parser for command-line options, arguments and sub-commands * Example: Example<7>. * ArgumentParser objects:: * The add_argument() method: The add_argument method. * The parse_args() method: The parse_args method. * Other utilities:: * Upgrading optparse code:: Example * Creating a parser:: * Adding arguments:: * Parsing arguments:: ArgumentParser objects * prog:: * usage:: * description:: * epilog:: * parents:: * formatter_class:: * prefix_chars:: * fromfile_prefix_chars:: * argument_default:: * allow_abbrev:: * conflict_handler:: * add_help:: The add_argument() method * name or flags:: * action:: * nargs:: * const:: * default:: * type:: * choices:: * required:: * help:: * metavar:: * dest:: * Action classes:: The parse_args() method * Option value syntax:: * Invalid arguments:: * Arguments containing -:: * Argument abbreviations (prefix matching): Argument abbreviations prefix matching. * Beyond sys.argv: Beyond sys argv. * The Namespace object:: Other utilities * Sub-commands:: * FileType objects:: * Argument groups:: * Mutual exclusion:: * Parser defaults:: * Printing help:: * Partial parsing:: * Customizing file parsing:: * Exiting methods:: * Intermixed parsing:: logging — Logging facility for Python * Logger Objects:: * Logging Levels:: * Handler Objects:: * Formatter Objects:: * Filter Objects:: * LogRecord Objects:: * LogRecord attributes:: * LoggerAdapter Objects:: * Thread Safety:: * Module-Level Functions:: * Module-Level Attributes:: * Integration with the warnings module:: logging.config — Logging configuration * Configuration functions:: * Configuration dictionary schema:: * Configuration file format:: Configuration dictionary schema * Dictionary Schema Details:: * Incremental Configuration:: * Object connections:: * User-defined objects:: * Access to external objects:: * Access to internal objects:: * Import resolution and custom importers:: logging.handlers — Logging handlers * StreamHandler:: * FileHandler:: * NullHandler:: * WatchedFileHandler:: * BaseRotatingHandler:: * RotatingFileHandler:: * TimedRotatingFileHandler:: * SocketHandler:: * DatagramHandler:: * SysLogHandler:: * NTEventLogHandler:: * SMTPHandler:: * MemoryHandler:: * HTTPHandler:: * QueueHandler:: * QueueListener:: curses — Terminal handling for character-cell displays * Functions: Functions<3>. * Window Objects:: * Constants: Constants<6>. curses.textpad — Text input widget for curses programs * Textbox objects:: curses.panel — A panel stack extension for curses * Functions: Functions<4>. * Panel Objects:: platform — Access to underlying platform’s identifying data * Cross Platform:: * Java Platform:: * Windows Platform:: * Mac OS Platform:: * Unix Platforms:: ctypes — A foreign function library for Python * ctypes tutorial:: * ctypes reference:: ctypes tutorial * Loading dynamic link libraries:: * Accessing functions from loaded dlls:: * Calling functions:: * Fundamental data types:: * Calling functions, continued: Calling functions continued. * Calling functions with your own custom data types:: * Specifying the required argument types (function prototypes): Specifying the required argument types function prototypes. * Return types:: * Passing pointers (or; passing parameters by reference): Passing pointers or passing parameters by reference. * Structures and unions:: * Structure/union alignment and byte order:: * Bit fields in structures and unions:: * Arrays:: * Pointers:: * Type conversions:: * Incomplete Types:: * Callback functions:: * Accessing values exported from dlls:: * Surprises:: * Variable-sized data types:: ctypes reference * Finding shared libraries:: * Loading shared libraries:: * Foreign functions:: * Function prototypes:: * Utility functions:: * Data types:: * Fundamental data types: Fundamental data types<2>. * Structured data types:: * Arrays and pointers:: Concurrent Execution * threading — Thread-based parallelism:: * multiprocessing — Process-based parallelism:: * multiprocessing.shared_memory — Provides shared memory for direct access across processes: multiprocessing shared_memory — Provides shared memory for direct access across processes. * The concurrent package:: * concurrent.futures — Launching parallel tasks: concurrent futures — Launching parallel tasks. * subprocess — Subprocess management:: * sched — Event scheduler:: * queue — A synchronized queue class:: * contextvars — Context Variables:: * _thread — Low-level threading API:: * _dummy_thread — Drop-in replacement for the _thread module:: * dummy_threading — Drop-in replacement for the threading module:: threading — Thread-based parallelism * Thread-Local Data:: * Thread Objects:: * Lock Objects:: * RLock Objects:: * Condition Objects:: * Semaphore Objects:: * Event Objects:: * Timer Objects:: * Barrier Objects:: * Using locks, conditions, and semaphores in the with statement: Using locks conditions and semaphores in the with statement. Semaphore Objects * Semaphore Example:: multiprocessing — Process-based parallelism * Introduction: Introduction<8>. * Reference:: * Programming guidelines:: * Examples: Examples<10>. Introduction * The Process class:: * Contexts and start methods:: * Exchanging objects between processes:: * Synchronization between processes:: * Sharing state between processes:: * Using a pool of workers:: Reference * Process and exceptions:: * Pipes and Queues:: * Miscellaneous: Miscellaneous<3>. * Connection Objects: Connection Objects<2>. * Synchronization primitives:: * Shared ctypes Objects:: * Managers:: * Proxy Objects:: * Process Pools:: * Listeners and Clients:: * Authentication keys:: * Logging: Logging<2>. * The multiprocessing.dummy module: The multiprocessing dummy module. Shared ctypes Objects * The multiprocessing.sharedctypes module: The multiprocessing sharedctypes module. Managers * Customized managers:: * Using a remote manager:: Proxy Objects * Cleanup:: Listeners and Clients * Address Formats:: Programming guidelines * All start methods:: * The spawn and forkserver start methods:: concurrent.futures — Launching parallel tasks * Executor Objects:: * ThreadPoolExecutor:: * ProcessPoolExecutor:: * Future Objects:: * Module Functions:: * Exception classes:: ThreadPoolExecutor * ThreadPoolExecutor Example:: ProcessPoolExecutor * ProcessPoolExecutor Example:: subprocess — Subprocess management * Using the subprocess Module:: * Security Considerations:: * Popen Objects:: * Windows Popen Helpers:: * Older high-level API:: * Replacing Older Functions with the subprocess Module:: * Legacy Shell Invocation Functions:: * Notes:: Using the subprocess Module * Frequently Used Arguments:: * Popen Constructor:: * Exceptions: Exceptions<7>. Windows Popen Helpers * Windows Constants:: Replacing Older Functions with the subprocess Module * Replacing /bin/sh shell command substitution:: * Replacing shell pipeline:: * Replacing os.system(): Replacing os system. * Replacing the os.spawn family: Replacing the os spawn family. * Replacing os.popen(), os.popen2(), os.popen3(): Replacing os popen os popen2 os popen3. * Replacing functions from the popen2 module:: Notes * Converting an argument sequence to a string on Windows:: sched — Event scheduler * Scheduler Objects:: queue — A synchronized queue class * Queue Objects:: * SimpleQueue Objects:: contextvars — Context Variables * Context Variables:: * Manual Context Management:: * asyncio support:: Networking and Interprocess Communication * asyncio — Asynchronous I/O:: * socket — Low-level networking interface:: * ssl — TLS/SSL wrapper for socket objects:: * select — Waiting for I/O completion:: * selectors — High-level I/O multiplexing:: * asyncore — Asynchronous socket handler:: * asynchat — Asynchronous socket command/response handler:: * signal — Set handlers for asynchronous events:: * mmap — Memory-mapped file support:: asyncio — Asynchronous I/O * Coroutines and Tasks:: * Streams:: * Synchronization Primitives:: * Subprocesses:: * Queues:: * Exceptions: Exceptions<9>. * Event Loop:: * Futures:: * Transports and Protocols:: * Policies:: * Platform Support:: * High-level API Index:: * Low-level API Index:: * Developing with asyncio:: Coroutines and Tasks * Coroutines: Coroutines<3>. * Awaitables:: * Running an asyncio Program:: * Creating Tasks:: * Sleeping:: * Running Tasks Concurrently:: * Shielding From Cancellation:: * Timeouts:: * Waiting Primitives:: * Scheduling From Other Threads:: * Introspection:: * Task Object:: * Generator-based Coroutines:: Streams * StreamReader:: * StreamWriter:: * Examples: Examples<11>. Examples * TCP echo client using streams:: * TCP echo server using streams:: * Get HTTP headers:: * Register an open socket to wait for data using streams:: Synchronization Primitives * Lock:: * Event:: * Condition:: * Semaphore:: * BoundedSemaphore:: Subprocesses * Creating Subprocesses:: * Constants: Constants<7>. * Interacting with Subprocesses:: Interacting with Subprocesses * Subprocess and Threads:: * Examples: Examples<12>. Queues * Queue:: * Priority Queue:: * LIFO Queue:: * Exceptions: Exceptions<8>. * Examples: Examples<13>. Event Loop * Event Loop Methods:: * Callback Handles:: * Server Objects:: * Event Loop Implementations:: * Examples: Examples<14>. Event Loop Methods * Running and stopping the loop:: * Scheduling callbacks:: * Scheduling delayed callbacks:: * Creating Futures and Tasks:: * Opening network connections:: * Creating network servers:: * Transferring files:: * TLS Upgrade:: * Watching file descriptors:: * Working with socket objects directly:: * DNS:: * Working with pipes:: * Unix signals:: * Executing code in thread or process pools:: * Error Handling API:: * Enabling debug mode:: * Running Subprocesses:: Examples * Hello World with call_soon(): Hello World with call_soon. * Display the current date with call_later(): Display the current date with call_later. * Watch a file descriptor for read events:: * Set signal handlers for SIGINT and SIGTERM:: Futures * Future Functions:: * Future Object:: Transports and Protocols * Transports:: * Protocols:: * Examples: Examples<15>. Transports * Transports Hierarchy:: * Base Transport:: * Read-only Transports:: * Write-only Transports:: * Datagram Transports:: * Subprocess Transports:: Protocols * Base Protocols:: * Base Protocol:: * Streaming Protocols:: * Buffered Streaming Protocols:: * Datagram Protocols:: * Subprocess Protocols:: Examples * TCP Echo Server:: * TCP Echo Client:: * UDP Echo Server:: * UDP Echo Client:: * Connecting Existing Sockets:: * loop.subprocess_exec() and SubprocessProtocol: loop subprocess_exec and SubprocessProtocol. Policies * Getting and Setting the Policy:: * Policy Objects:: * Process Watchers:: * Custom Policies:: Platform Support * All Platforms:: * Windows:: * macOS:: Windows * Subprocess Support on Windows:: High-level API Index * Tasks:: * Queues: Queues<2>. * Subprocesses: Subprocesses<2>. * Streams: Streams<2>. * Synchronization:: * Exceptions: Exceptions<10>. Low-level API Index * Obtaining the Event Loop:: * Event Loop Methods: Event Loop Methods<2>. * Transports: Transports<2>. * Protocols: Protocols<2>. * Event Loop Policies:: Developing with asyncio * Debug Mode:: * Concurrency and Multithreading:: * Running Blocking Code:: * Logging: Logging<3>. * Detect never-awaited coroutines:: * Detect never-retrieved exceptions:: socket — Low-level networking interface * Socket families:: * Module contents:: * Socket Objects:: * Notes on socket timeouts:: * Example: Example<8>. Module contents * Exceptions: Exceptions<11>. * Constants: Constants<8>. * Functions: Functions<5>. Functions * Creating sockets:: * Other functions: Other functions<2>. Notes on socket timeouts * Timeouts and the connect method:: * Timeouts and the accept method:: ssl — TLS/SSL wrapper for socket objects * Functions, Constants, and Exceptions: Functions Constants and Exceptions. * SSL Sockets:: * SSL Contexts:: * Certificates:: * Examples: Examples<16>. * Notes on non-blocking sockets:: * Memory BIO Support: Memory BIO Support<2>. * SSL session:: * Security considerations:: * TLS 1.3: TLS 1 3. * LibreSSL support:: Functions, Constants, and Exceptions * Socket creation:: * Context creation:: * Exceptions: Exceptions<12>. * Random generation:: * Certificate handling:: * Constants: Constants<9>. Certificates * Certificate chains:: * CA certificates:: * Combined key and certificate:: * Self-signed certificates:: Examples * Testing for SSL support:: * Client-side operation:: * Server-side operation:: Security considerations * Best defaults:: * Manual settings:: * Multi-processing:: Manual settings * Verifying certificates:: * Protocol versions:: * Cipher selection:: select — Waiting for I/O completion * /dev/poll Polling Objects:: * Edge and Level Trigger Polling (epoll) Objects: Edge and Level Trigger Polling epoll Objects. * Polling Objects:: * Kqueue Objects:: * Kevent Objects:: selectors — High-level I/O multiplexing * Introduction: Introduction<9>. * Classes: Classes<3>. * Examples: Examples<17>. asyncore — Asynchronous socket handler * asyncore Example basic HTTP client:: * asyncore Example basic echo server:: asynchat — Asynchronous socket command/response handler * asynchat Example:: signal — Set handlers for asynchronous events * General rules:: * Module contents: Module contents<2>. * Example: Example<9>. * Note on SIGPIPE:: General rules * Execution of Python signal handlers:: * Signals and threads:: mmap — Memory-mapped file support * MADV_* Constants:: Internet Data Handling * email — An email and MIME handling package:: * json — JSON encoder and decoder:: * mailcap — Mailcap file handling:: * mailbox — Manipulate mailboxes in various formats:: * mimetypes — Map filenames to MIME types:: * base64 — Base16, Base32, Base64, Base85 Data Encodings: base64 — Base16 Base32 Base64 Base85 Data Encodings. * binhex — Encode and decode binhex4 files:: * binascii — Convert between binary and ASCII:: * quopri — Encode and decode MIME quoted-printable data:: * uu — Encode and decode uuencode files:: email — An email and MIME handling package * email.message; Representing an email message: email message Representing an email message. * email.parser; Parsing email messages: email parser Parsing email messages. * email.generator; Generating MIME documents: email generator Generating MIME documents. * email.policy; Policy Objects: email policy Policy Objects. * email.errors; Exception and Defect classes: email errors Exception and Defect classes. * email.headerregistry; Custom Header Objects: email headerregistry Custom Header Objects. * email.contentmanager; Managing MIME Content: email contentmanager Managing MIME Content. * email; Examples: email Examples. * email.message.Message; Representing an email message using the compat32 API: email message Message Representing an email message using the compat32 API. * email.mime; Creating email and MIME objects from scratch: email mime Creating email and MIME objects from scratch. * email.header; Internationalized headers: email header Internationalized headers. * email.charset; Representing character sets: email charset Representing character sets. * email.encoders; Encoders: email encoders Encoders. * email.utils; Miscellaneous utilities: email utils Miscellaneous utilities. * email.iterators; Iterators: email iterators Iterators. email.parser: Parsing email messages * FeedParser API:: * Parser API:: * Additional notes:: email.contentmanager: Managing MIME Content * Content Manager Instances:: json — JSON encoder and decoder * Basic Usage:: * Encoders and Decoders:: * Exceptions: Exceptions<13>. * Standard Compliance and Interoperability:: * Command Line Interface: Command Line Interface<2>. Standard Compliance and Interoperability * Character Encodings:: * Infinite and NaN Number Values:: * Repeated Names Within an Object:: * Top-level Non-Object, Non-Array Values: Top-level Non-Object Non-Array Values. * Implementation Limitations:: Command Line Interface * Command line options: Command line options<2>. mailbox — Manipulate mailboxes in various formats * Mailbox objects:: * Message objects:: * Exceptions: Exceptions<14>. * Examples: Examples<18>. Mailbox objects * Maildir:: * mbox:: * MH:: * Babyl:: * MMDF:: Message objects * MaildirMessage:: * mboxMessage:: * MHMessage:: * BabylMessage:: * MMDFMessage:: mimetypes — Map filenames to MIME types * MimeTypes Objects:: binhex — Encode and decode binhex4 files * Notes: Notes<2>. Structured Markup Processing Tools * html — HyperText Markup Language support:: * html.parser — Simple HTML and XHTML parser: html parser — Simple HTML and XHTML parser. * html.entities — Definitions of HTML general entities: html entities — Definitions of HTML general entities. * XML Processing Modules:: * xml.etree.ElementTree — The ElementTree XML API: xml etree ElementTree — The ElementTree XML API. * xml.dom — The Document Object Model API: xml dom — The Document Object Model API. * xml.dom.minidom — Minimal DOM implementation: xml dom minidom — Minimal DOM implementation. * xml.dom.pulldom — Support for building partial DOM trees: xml dom pulldom — Support for building partial DOM trees. * xml.sax — Support for SAX2 parsers: xml sax — Support for SAX2 parsers. * xml.sax.handler — Base classes for SAX handlers: xml sax handler — Base classes for SAX handlers. * xml.sax.saxutils — SAX Utilities: xml sax saxutils — SAX Utilities. * xml.sax.xmlreader — Interface for XML parsers: xml sax xmlreader — Interface for XML parsers. * xml.parsers.expat — Fast XML parsing using Expat: xml parsers expat — Fast XML parsing using Expat. html.parser — Simple HTML and XHTML parser * Example HTML Parser Application:: * HTMLParser Methods:: * Examples: Examples<19>. XML Processing Modules * XML vulnerabilities:: * The defusedxml Package:: xml.etree.ElementTree — The ElementTree XML API * Tutorial:: * XPath support:: * Reference: Reference<2>. * XInclude support:: * Reference: Reference<3>. Tutorial * XML tree and elements:: * Parsing XML:: * Pull API for non-blocking parsing:: * Finding interesting elements:: * Modifying an XML File:: * Building XML documents:: * Parsing XML with Namespaces:: * Additional resources:: XPath support * Example: Example<10>. * Supported XPath syntax:: Reference * Functions: Functions<6>. XInclude support * Example: Example<11>. Reference * Functions: Functions<7>. * Element Objects:: * ElementTree Objects:: * QName Objects:: * TreeBuilder Objects:: * XMLParser Objects:: * XMLPullParser Objects:: * Exceptions: Exceptions<15>. xml.dom — The Document Object Model API * Module Contents: Module Contents<4>. * Objects in the DOM:: * Conformance:: Objects in the DOM * DOMImplementation Objects:: * Node Objects:: * NodeList Objects:: * DocumentType Objects:: * Document Objects:: * Element Objects: Element Objects<2>. * Attr Objects:: * NamedNodeMap Objects:: * Comment Objects:: * Text and CDATASection Objects:: * ProcessingInstruction Objects:: * Exceptions: Exceptions<16>. Conformance * Type Mapping:: * Accessor Methods:: xml.dom.minidom — Minimal DOM implementation * DOM Objects:: * DOM Example:: * minidom and the DOM standard:: xml.dom.pulldom — Support for building partial DOM trees * DOMEventStream Objects:: xml.sax — Support for SAX2 parsers * SAXException Objects:: xml.sax.handler — Base classes for SAX handlers * ContentHandler Objects:: * DTDHandler Objects:: * EntityResolver Objects:: * ErrorHandler Objects:: xml.sax.xmlreader — Interface for XML parsers * XMLReader Objects:: * IncrementalParser Objects:: * Locator Objects:: * InputSource Objects:: * The Attributes Interface:: * The AttributesNS Interface:: xml.parsers.expat — Fast XML parsing using Expat * XMLParser Objects: XMLParser Objects<2>. * ExpatError Exceptions:: * Example: Example<12>. * Content Model Descriptions:: * Expat error constants:: Internet Protocols and Support * webbrowser — Convenient Web-browser controller:: * cgi — Common Gateway Interface support:: * cgitb — Traceback manager for CGI scripts:: * wsgiref — WSGI Utilities and Reference Implementation:: * urllib — URL handling modules:: * urllib.request — Extensible library for opening URLs: urllib request — Extensible library for opening URLs. * urllib.response — Response classes used by urllib: urllib response — Response classes used by urllib. * urllib.parse — Parse URLs into components: urllib parse — Parse URLs into components. * urllib.error — Exception classes raised by urllib.request: urllib error — Exception classes raised by urllib request. * urllib.robotparser — Parser for robots.txt: urllib robotparser — Parser for robots txt. * http — HTTP modules:: * http.client — HTTP protocol client: http client — HTTP protocol client. * ftplib — FTP protocol client:: * poplib — POP3 protocol client:: * imaplib — IMAP4 protocol client:: * nntplib — NNTP protocol client:: * smtplib — SMTP protocol client:: * smtpd — SMTP Server:: * telnetlib — Telnet client:: * uuid — UUID objects according to RFC 4122:: * socketserver — A framework for network servers:: * http.server — HTTP servers: http server — HTTP servers. * http.cookies — HTTP state management: http cookies — HTTP state management. * http.cookiejar — Cookie handling for HTTP clients: http cookiejar — Cookie handling for HTTP clients. * xmlrpc — XMLRPC server and client modules:: * xmlrpc.client — XML-RPC client access: xmlrpc client — XML-RPC client access. * xmlrpc.server — Basic XML-RPC servers: xmlrpc server — Basic XML-RPC servers. * ipaddress — IPv4/IPv6 manipulation library:: webbrowser — Convenient Web-browser controller * Browser Controller Objects:: cgi — Common Gateway Interface support * Introduction: Introduction<10>. * Using the cgi module:: * Higher Level Interface:: * Functions: Functions<8>. * Caring about security:: * Installing your CGI script on a Unix system:: * Testing your CGI script:: * Debugging CGI scripts:: * Common problems and solutions:: wsgiref — WSGI Utilities and Reference Implementation * wsgiref.util – WSGI environment utilities: wsgiref util – WSGI environment utilities. * wsgiref.headers – WSGI response header tools: wsgiref headers – WSGI response header tools. * wsgiref.simple_server – a simple WSGI HTTP server: wsgiref simple_server – a simple WSGI HTTP server. * wsgiref.validate — WSGI conformance checker: wsgiref validate — WSGI conformance checker. * wsgiref.handlers – server/gateway base classes: wsgiref handlers – server/gateway base classes. * Examples: Examples<20>. urllib.request — Extensible library for opening URLs * Request Objects:: * OpenerDirector Objects:: * BaseHandler Objects:: * HTTPRedirectHandler Objects:: * HTTPCookieProcessor Objects:: * ProxyHandler Objects:: * HTTPPasswordMgr Objects:: * HTTPPasswordMgrWithPriorAuth Objects:: * AbstractBasicAuthHandler Objects:: * HTTPBasicAuthHandler Objects:: * ProxyBasicAuthHandler Objects:: * AbstractDigestAuthHandler Objects:: * HTTPDigestAuthHandler Objects:: * ProxyDigestAuthHandler Objects:: * HTTPHandler Objects:: * HTTPSHandler Objects:: * FileHandler Objects:: * DataHandler Objects:: * FTPHandler Objects:: * CacheFTPHandler Objects:: * UnknownHandler Objects:: * HTTPErrorProcessor Objects:: * Examples: Examples<21>. * Legacy interface:: * urllib.request Restrictions: urllib request Restrictions. urllib.parse — Parse URLs into components * URL Parsing:: * Parsing ASCII Encoded Bytes:: * Structured Parse Results:: * URL Quoting:: http — HTTP modules * HTTP status codes:: http.client — HTTP protocol client * HTTPConnection Objects:: * HTTPResponse Objects:: * Examples: Examples<22>. * HTTPMessage Objects:: ftplib — FTP protocol client * FTP Objects:: * FTP_TLS Objects:: poplib — POP3 protocol client * POP3 Objects:: * POP3 Example:: imaplib — IMAP4 protocol client * IMAP4 Objects:: * IMAP4 Example:: nntplib — NNTP protocol client * NNTP Objects:: * Utility functions: Utility functions<2>. NNTP Objects * Attributes:: * Methods: Methods<3>. smtplib — SMTP protocol client * SMTP Objects:: * SMTP Example:: smtpd — SMTP Server * SMTPServer Objects:: * DebuggingServer Objects:: * PureProxy Objects:: * MailmanProxy Objects:: * SMTPChannel Objects:: telnetlib — Telnet client * Telnet Objects:: * Telnet Example:: uuid — UUID objects according to RFC 4122 * Example: Example<13>. socketserver — A framework for network servers * Server Creation Notes:: * Server Objects: Server Objects<2>. * Request Handler Objects:: * Examples: Examples<23>. Examples * socketserver.TCPServer Example: socketserver TCPServer Example. * socketserver.UDPServer Example: socketserver UDPServer Example. * Asynchronous Mixins:: http.cookies — HTTP state management * Cookie Objects:: * Morsel Objects:: * Example: Example<14>. http.cookiejar — Cookie handling for HTTP clients * CookieJar and FileCookieJar Objects:: * FileCookieJar subclasses and co-operation with web browsers:: * CookiePolicy Objects:: * DefaultCookiePolicy Objects:: * Cookie Objects: Cookie Objects<2>. * Examples: Examples<24>. xmlrpc.client — XML-RPC client access * ServerProxy Objects:: * DateTime Objects:: * Binary Objects:: * Fault Objects:: * ProtocolError Objects:: * MultiCall Objects:: * Convenience Functions:: * Example of Client Usage:: * Example of Client and Server Usage:: xmlrpc.server — Basic XML-RPC servers * SimpleXMLRPCServer Objects:: * CGIXMLRPCRequestHandler:: * Documenting XMLRPC server:: * DocXMLRPCServer Objects:: * DocCGIXMLRPCRequestHandler:: SimpleXMLRPCServer Objects * SimpleXMLRPCServer Example:: ipaddress — IPv4/IPv6 manipulation library * Convenience factory functions:: * IP Addresses:: * IP Network definitions:: * Interface objects:: * Other Module Level Functions:: * Custom Exceptions:: IP Addresses * Address objects:: * Conversion to Strings and Integers:: * Operators: Operators<3>. Operators * Comparison operators:: * Arithmetic operators:: IP Network definitions * Prefix, net mask and host mask: Prefix net mask and host mask. * Network objects:: * Operators: Operators<4>. Operators * Logical operators:: * Iteration: Iteration<2>. * Networks as containers of addresses:: Interface objects * Operators: Operators<5>. Operators * Logical operators: Logical operators<2>. Multimedia Services * audioop — Manipulate raw audio data:: * aifc — Read and write AIFF and AIFC files:: * sunau — Read and write Sun AU files:: * wave — Read and write WAV files:: * chunk — Read IFF chunked data:: * colorsys — Conversions between color systems:: * imghdr — Determine the type of an image:: * sndhdr — Determine type of sound file:: * ossaudiodev — Access to OSS-compatible audio devices:: sunau — Read and write Sun AU files * AU_read Objects:: * AU_write Objects:: wave — Read and write WAV files * Wave_read Objects:: * Wave_write Objects:: ossaudiodev — Access to OSS-compatible audio devices * Audio Device Objects:: * Mixer Device Objects:: Internationalization * gettext — Multilingual internationalization services:: * locale — Internationalization services:: gettext — Multilingual internationalization services * GNU gettext API:: * Class-based API:: * Internationalizing your programs and modules:: * Acknowledgements: Acknowledgements<9>. Class-based API * The NullTranslations class:: * The GNUTranslations class:: * Solaris message catalog support:: * The Catalog constructor:: Internationalizing your programs and modules * Localizing your module:: * Localizing your application:: * Changing languages on the fly:: * Deferred translations:: locale — Internationalization services * Background, details, hints, tips and caveats: Background details hints tips and caveats. * For extension writers and programs that embed Python:: * Access to message catalogs:: Program Frameworks * turtle — Turtle graphics:: * cmd — Support for line-oriented command interpreters:: * shlex — Simple lexical analysis:: turtle — Turtle graphics * Introduction: Introduction<11>. * Overview of available Turtle and Screen methods:: * Methods of RawTurtle/Turtle and corresponding functions:: * Methods of TurtleScreen/Screen and corresponding functions:: * Public classes:: * Help and configuration:: * turtledemo — Demo scripts:: * Changes since Python 2.6: Changes since Python 2 6. * Changes since Python 3.0: Changes since Python 3 0. Overview of available Turtle and Screen methods * Turtle methods:: * Methods of TurtleScreen/Screen:: Methods of RawTurtle/Turtle and corresponding functions * Turtle motion:: * Tell Turtle’s state:: * Settings for measurement:: * Pen control:: * Turtle state:: * Using events:: * Special Turtle methods:: * Compound shapes:: Pen control * Drawing state:: * Color control:: * Filling:: * More drawing control:: Turtle state * Visibility:: * Appearance:: Methods of TurtleScreen/Screen and corresponding functions * Window control:: * Animation control:: * Using screen events:: * Input methods:: * Settings and special methods:: * Methods specific to Screen, not inherited from TurtleScreen: Methods specific to Screen not inherited from TurtleScreen. Help and configuration * How to use help:: * Translation of docstrings into different languages:: * How to configure Screen and Turtles:: cmd — Support for line-oriented command interpreters * Cmd Objects:: * Cmd Example:: shlex — Simple lexical analysis * shlex Objects:: * Parsing Rules:: * Improved Compatibility with Shells:: Graphical User Interfaces with Tk * tkinter — Python interface to Tcl/Tk:: * tkinter.ttk — Tk themed widgets: tkinter ttk — Tk themed widgets. * tkinter.tix — Extension widgets for Tk: tkinter tix — Extension widgets for Tk. * tkinter.scrolledtext — Scrolled Text Widget: tkinter scrolledtext — Scrolled Text Widget. * IDLE: IDLE<3>. * Other Graphical User Interface Packages:: tkinter — Python interface to Tcl/Tk * Tkinter Modules:: * Tkinter Life Preserver:: * A (Very) Quick Look at Tcl/Tk: A Very Quick Look at Tcl/Tk. * Mapping Basic Tk into Tkinter:: * How Tk and Tkinter are Related:: * Handy Reference:: * File Handlers:: Tkinter Life Preserver * How To Use This Section:: * A Simple Hello World Program:: Handy Reference * Setting Options:: * The Packer:: * Packer Options:: * Coupling Widget Variables:: * The Window Manager:: * Tk Option Data Types:: * Bindings and Events:: * The index Parameter:: * Images:: tkinter.ttk — Tk themed widgets * Using Ttk:: * Ttk Widgets:: * Widget:: * Combobox:: * Spinbox:: * Notebook:: * Progressbar:: * Separator:: * Sizegrip:: * Treeview:: * Ttk Styling:: Widget * Standard Options:: * Scrollable Widget Options:: * Label Options:: * Compatibility Options:: * Widget States:: * ttk.Widget: ttk Widget. Combobox * Options:: * Virtual events:: * ttk.Combobox: ttk Combobox. Spinbox * Options: Options<2>. * Virtual events: Virtual events<2>. * ttk.Spinbox: ttk Spinbox. Notebook * Options: Options<3>. * Tab Options:: * Tab Identifiers:: * Virtual Events:: * ttk.Notebook: ttk Notebook. Progressbar * Options: Options<4>. * ttk.Progressbar: ttk Progressbar. Separator * Options: Options<5>. Sizegrip * Platform-specific notes:: * Bugs:: Treeview * Options: Options<6>. * Item Options:: * Tag Options:: * Column Identifiers:: * Virtual Events: Virtual Events<2>. * ttk.Treeview: ttk Treeview. Ttk Styling * Layouts:: tkinter.tix — Extension widgets for Tk * Using Tix:: * Tix Widgets:: * Tix Commands:: Tix Widgets * Basic Widgets:: * File Selectors:: * Hierarchical ListBox:: * Tabular ListBox:: * Manager Widgets:: * Image Types:: * Miscellaneous Widgets:: * Form Geometry Manager:: IDLE * Menus:: * Editing and navigation:: * Startup and code execution:: * Help and preferences:: Menus * File menu (Shell and Editor): File menu Shell and Editor. * Edit menu (Shell and Editor): Edit menu Shell and Editor. * Format menu (Editor window only): Format menu Editor window only. * Run menu (Editor window only): Run menu Editor window only. * Shell menu (Shell window only): Shell menu Shell window only. * Debug menu (Shell window only): Debug menu Shell window only. * Options menu (Shell and Editor): Options menu Shell and Editor. * Window menu (Shell and Editor): Window menu Shell and Editor. * Help menu (Shell and Editor): Help menu Shell and Editor. * Context Menus:: Editing and navigation * Editor windows:: * Key bindings:: * Automatic indentation:: * Completions:: * Calltips:: * Code Context:: * Python Shell window:: * Text colors:: Startup and code execution * Command line usage:: * Startup failure:: * Running user code:: * User output in Shell:: * Developing tkinter applications:: * Running without a subprocess:: Help and preferences * Help sources:: * Setting preferences:: * IDLE on macOS:: * Extensions:: Development Tools * typing — Support for type hints:: * pydoc — Documentation generator and online help system:: * doctest — Test interactive Python examples:: * unittest — Unit testing framework:: * unittest.mock — mock object library: unittest mock — mock object library. * unittest.mock — getting started: unittest mock — getting started. * 2to3 - Automated Python 2 to 3 code translation:: * test — Regression tests package for Python:: * test.support — Utilities for the Python test suite: test support — Utilities for the Python test suite. * test.support.script_helper — Utilities for the Python execution tests: test support script_helper — Utilities for the Python execution tests. typing — Support for type hints * Type aliases:: * NewType:: * Callable:: * Generics:: * User-defined generic types:: * The Any type:: * Nominal vs structural subtyping:: * Classes, functions, and decorators: Classes functions and decorators. doctest — Test interactive Python examples * Simple Usage; Checking Examples in Docstrings: Simple Usage Checking Examples in Docstrings. * Simple Usage; Checking Examples in a Text File: Simple Usage Checking Examples in a Text File. * How It Works:: * Basic API:: * Unittest API:: * Advanced API:: * Debugging:: * Soapbox:: How It Works * Which Docstrings Are Examined?:: * How are Docstring Examples Recognized?:: * What’s the Execution Context?:: * What About Exceptions?:: * Option Flags:: * Directives:: * Warnings: Warnings<2>. Advanced API * DocTest Objects:: * Example Objects:: * DocTestFinder objects:: * DocTestParser objects:: * DocTestRunner objects:: * OutputChecker objects:: unittest — Unit testing framework * Basic example:: * Command-Line Interface: Command-Line Interface<3>. * Test Discovery:: * Organizing test code:: * Re-using old test code:: * Skipping tests and expected failures:: * Distinguishing test iterations using subtests:: * Classes and functions:: * Class and Module Fixtures:: * Signal Handling:: Command-Line Interface * Command-line options: Command-line options<3>. Classes and functions * Test cases:: * Grouping tests:: * Loading and running tests:: Test cases * Deprecated aliases:: Loading and running tests * load_tests Protocol:: Class and Module Fixtures * setUpClass and tearDownClass:: * setUpModule and tearDownModule:: unittest.mock — mock object library * Quick Guide:: * The Mock Class:: * The patchers:: * MagicMock and magic method support:: * Helpers:: The Mock Class * Calling:: * Deleting Attributes:: * Mock names and the name attribute:: * Attaching Mocks as Attributes:: The patchers * patch:: * patch.object: patch object. * patch.dict: patch dict. * patch.multiple: patch multiple. * patch methods; start and stop: patch methods start and stop. * patch builtins:: * TEST_PREFIX:: * Nesting Patch Decorators:: * Where to patch:: * Patching Descriptors and Proxy Objects:: MagicMock and magic method support * Mocking Magic Methods:: * Magic Mock:: Helpers * sentinel:: * DEFAULT:: * call:: * create_autospec:: * ANY:: * FILTER_DIR:: * mock_open:: * Autospeccing:: * Sealing mocks:: unittest.mock — getting started * Using Mock:: * Patch Decorators:: * Further Examples:: Using Mock * Mock Patching Methods:: * Mock for Method Calls on an Object:: * Mocking Classes:: * Naming your mocks:: * Tracking all Calls:: * Setting Return Values and Attributes:: * Raising exceptions with mocks:: * Side effect functions and iterables:: * Mocking asynchronous iterators:: * Mocking asynchronous context manager:: * Creating a Mock from an Existing Object:: Further Examples * Mocking chained calls:: * Partial mocking:: * Mocking a Generator Method:: * Applying the same patch to every test method:: * Mocking Unbound Methods:: * Checking multiple calls with mock:: * Coping with mutable arguments:: * Nesting Patches:: * Mocking a dictionary with MagicMock:: * Mock subclasses and their attributes:: * Mocking imports with patch.dict: Mocking imports with patch dict. * Tracking order of calls and less verbose call assertions:: * More complex argument matching:: 2to3 - Automated Python 2 to 3 code translation * Using 2to3:: * Fixers:: * lib2to3 - 2to3’s library:: test — Regression tests package for Python * Writing Unit Tests for the test package:: * Running tests using the command-line interface:: Debugging and Profiling * Audit events table:: * bdb — Debugger framework:: * faulthandler — Dump the Python traceback:: * pdb — The Python Debugger:: * The Python Profilers:: * timeit — Measure execution time of small code snippets:: * trace — Trace or track Python statement execution:: * tracemalloc — Trace memory allocations:: faulthandler — Dump the Python traceback * Dumping the traceback:: * Fault handler state:: * Dumping the tracebacks after a timeout:: * Dumping the traceback on a user signal:: * Issue with file descriptors:: * Example: Example<15>. pdb — The Python Debugger * Debugger Commands:: The Python Profilers * Introduction to the profilers:: * Instant User’s Manual:: * profile and cProfile Module Reference:: * The Stats Class:: * What Is Deterministic Profiling?:: * Limitations:: * Calibration:: * Using a custom timer:: timeit — Measure execution time of small code snippets * Basic Examples: Basic Examples<2>. * Python Interface:: * Command-Line Interface: Command-Line Interface<4>. * Examples: Examples<25>. trace — Trace or track Python statement execution * Command-Line Usage:: * Programmatic Interface:: Command-Line Usage * Main options:: * Modifiers:: * Filters:: tracemalloc — Trace memory allocations * Examples: Examples<26>. * API:: Examples * Display the top 10:: * Compute differences:: * Get the traceback of a memory block:: * Pretty top:: API * Functions: Functions<9>. * DomainFilter:: * Filter:: * Frame:: * Snapshot:: * Statistic:: * StatisticDiff:: * Trace:: * Traceback:: Software Packaging and Distribution * distutils — Building and installing Python modules:: * ensurepip — Bootstrapping the pip installer:: * venv — Creation of virtual environments:: * zipapp — Manage executable Python zip archives:: ensurepip — Bootstrapping the pip installer * Command line interface:: * Module API:: venv — Creation of virtual environments * Creating virtual environments:: * API: API<2>. * An example of extending EnvBuilder:: zipapp — Manage executable Python zip archives * Basic Example:: * Command-Line Interface: Command-Line Interface<5>. * Python API:: * Examples: Examples<27>. * Specifying the Interpreter:: * Creating Standalone Applications with zipapp:: * The Python Zip Application Archive Format:: Creating Standalone Applications with zipapp * Making a Windows executable:: * Caveats:: Python Runtime Services * sys — System-specific parameters and functions:: * sysconfig — Provide access to Python’s configuration information:: * builtins — Built-in objects:: * __main__ — Top-level script environment:: * warnings — Warning control:: * dataclasses — Data Classes:: * contextlib — Utilities for with-statement contexts:: * abc — Abstract Base Classes:: * atexit — Exit handlers:: * traceback — Print or retrieve a stack traceback:: * __future__ — Future statement definitions:: * gc — Garbage Collector interface:: * inspect — Inspect live objects:: * site — Site-specific configuration hook:: sysconfig — Provide access to Python’s configuration information * Configuration variables:: * Installation paths:: * Other functions: Other functions<3>. * Using sysconfig as a script:: warnings — Warning control * Warning Categories:: * The Warnings Filter:: * Temporarily Suppressing Warnings:: * Testing Warnings:: * Updating Code For New Versions of Dependencies:: * Available Functions:: * Available Context Managers:: The Warnings Filter * Describing Warning Filters:: * Default Warning Filter:: * Overriding the default filter:: dataclasses — Data Classes * Module-level decorators, classes, and functions: Module-level decorators classes and functions. * Post-init processing:: * Class variables:: * Init-only variables:: * Frozen instances:: * Inheritance: Inheritance<2>. * Default factory functions:: * Mutable default values:: * Exceptions: Exceptions<17>. contextlib — Utilities for with-statement contexts * Utilities:: * Examples and Recipes: Examples and Recipes<2>. * Single use, reusable and reentrant context managers: Single use reusable and reentrant context managers. Examples and Recipes * Supporting a variable number of context managers:: * Catching exceptions from __enter__ methods:: * Cleaning up in an __enter__ implementation:: * Replacing any use of try-finally and flag variables:: * Using a context manager as a function decorator:: Single use, reusable and reentrant context managers * Reentrant context managers:: * Reusable context managers:: atexit — Exit handlers * atexit Example:: traceback — Print or retrieve a stack traceback * TracebackException Objects:: * StackSummary Objects:: * FrameSummary Objects:: * Traceback Examples:: inspect — Inspect live objects * Types and members:: * Retrieving source code:: * Introspecting callables with the Signature object:: * Classes and functions: Classes and functions<2>. * The interpreter stack:: * Fetching attributes statically:: * Current State of Generators and Coroutines:: * Code Objects Bit Flags:: * Command Line Interface: Command Line Interface<3>. site — Site-specific configuration hook * Readline configuration:: * Module contents: Module contents<3>. * Command Line Interface: Command Line Interface<4>. Custom Python Interpreters * code — Interpreter base classes:: * codeop — Compile Python code:: code — Interpreter base classes * Interactive Interpreter Objects:: * Interactive Console Objects:: Importing Modules * zipimport — Import modules from Zip archives:: * pkgutil — Package extension utility:: * modulefinder — Find modules used by a script:: * runpy — Locating and executing Python modules:: * importlib — The implementation of import:: * Using importlib.metadata: Using importlib metadata. zipimport — Import modules from Zip archives * zipimporter Objects:: * Examples: Examples<28>. modulefinder — Find modules used by a script * Example usage of ModuleFinder:: importlib — The implementation of import * Introduction: Introduction<12>. * Functions: Functions<10>. * importlib.abc – Abstract base classes related to import: importlib abc – Abstract base classes related to import. * importlib.resources – Resources: importlib resources – Resources. * importlib.machinery – Importers and path hooks: importlib machinery – Importers and path hooks. * importlib.util – Utility code for importers: importlib util – Utility code for importers. * Examples: Examples<29>. Examples * Importing programmatically:: * Checking if a module can be imported:: * Importing a source file directly:: * Setting up an importer:: * Approximating importlib.import_module(): Approximating importlib import_module. Using importlib.metadata * Overview: Overview<2>. * Functional API: Functional API<2>. * Distributions:: * Extending the search algorithm:: Functional API * Entry points:: * Distribution metadata:: * Distribution versions:: * Distribution files:: * Distribution requirements:: Python Language Services * parser — Access Python parse trees:: * ast — Abstract Syntax Trees:: * symtable — Access to the compiler’s symbol tables:: * symbol — Constants used with Python parse trees:: * token — Constants used with Python parse trees:: * keyword — Testing for Python keywords:: * tokenize — Tokenizer for Python source:: * tabnanny — Detection of ambiguous indentation:: * pyclbr — Python module browser support:: * py_compile — Compile Python source files:: * compileall — Byte-compile Python libraries:: * dis — Disassembler for Python bytecode:: * pickletools — Tools for pickle developers:: parser — Access Python parse trees * Creating ST Objects:: * Converting ST Objects:: * Queries on ST Objects:: * Exceptions and Error Handling:: * ST Objects:: * Example; Emulation of compile(): Example Emulation of compile. ast — Abstract Syntax Trees * Node classes:: * Abstract Grammar:: * ast Helpers:: symtable — Access to the compiler’s symbol tables * Generating Symbol Tables:: * Examining Symbol Tables:: tokenize — Tokenizer for Python source * Tokenizing Input:: * Command-Line Usage: Command-Line Usage<2>. * Examples: Examples<30>. pyclbr — Python module browser support * Function Objects:: * Class Objects: Class Objects<2>. compileall — Byte-compile Python libraries * Command-line use:: * Public functions:: dis — Disassembler for Python bytecode * Bytecode analysis:: * Analysis functions:: * Python Bytecode Instructions:: * Opcode collections:: pickletools — Tools for pickle developers * Command line usage: Command line usage<2>. * Programmatic Interface: Programmatic Interface<2>. Command line usage * Command line options: Command line options<3>. Miscellaneous Services * formatter — Generic output formatting:: formatter — Generic output formatting * The Formatter Interface:: * Formatter Implementations:: * The Writer Interface:: * Writer Implementations:: MS Windows Specific Services * msilib — Read and write Microsoft Installer files:: * msvcrt — Useful routines from the MS VC++ runtime:: * winreg — Windows registry access:: * winsound — Sound-playing interface for Windows:: msilib — Read and write Microsoft Installer files * Database Objects:: * View Objects:: * Summary Information Objects:: * Record Objects:: * Errors:: * CAB Objects:: * Directory Objects:: * Features: Features<3>. * GUI classes:: * Precomputed tables:: msvcrt — Useful routines from the MS VC++ runtime * File Operations:: * Console I/O:: * Other Functions:: winreg — Windows registry access * Functions: Functions<11>. * Constants: Constants<10>. * Registry Handle Objects:: Constants * HKEY_* Constants:: * Access Rights:: * Value Types:: Access Rights * 64-bit Specific:: Unix Specific Services * posix — The most common POSIX system calls:: * pwd — The password database:: * spwd — The shadow password database:: * grp — The group database:: * crypt — Function to check Unix passwords:: * termios — POSIX style tty control:: * tty — Terminal control functions:: * pty — Pseudo-terminal utilities:: * fcntl — The fcntl and ioctl system calls:: * pipes — Interface to shell pipelines:: * resource — Resource usage information:: * nis — Interface to Sun’s NIS (Yellow Pages): nis — Interface to Sun’s NIS Yellow Pages. * syslog — Unix syslog library routines:: posix — The most common POSIX system calls * Large File Support:: * Notable Module Contents:: crypt — Function to check Unix passwords * Hashing Methods:: * Module Attributes:: * Module Functions: Module Functions<2>. * Examples: Examples<31>. termios — POSIX style tty control * Example: Example<16>. pty — Pseudo-terminal utilities * Example: Example<17>. pipes — Interface to shell pipelines * Template Objects:: resource — Resource usage information * Resource Limits:: * Resource Usage:: syslog — Unix syslog library routines * Examples: Examples<32>. Examples * Simple example:: Superseded Modules * optparse — Parser for command line options:: * imp — Access the import internals:: optparse — Parser for command line options * Background:: * Tutorial: Tutorial<2>. * Reference Guide:: * Option Callbacks:: * Extending optparse:: Background * Terminology:: * What are options for?:: * What are positional arguments for?:: Tutorial * Understanding option actions:: * The store action:: * Handling boolean (flag) options: Handling boolean flag options. * Other actions:: * Default values:: * Generating help:: * Printing a version string:: * How optparse handles errors:: * Putting it all together:: Generating help * Grouping Options:: Reference Guide * Creating the parser:: * Populating the parser:: * Defining options:: * Option attributes:: * Standard option actions:: * Standard option types:: * Parsing arguments: Parsing arguments<2>. * Querying and manipulating your option parser:: * Conflicts between options:: * Cleanup: Cleanup<2>. * Other methods:: Option Callbacks * Defining a callback option:: * How callbacks are called:: * Raising errors in a callback:: * Callback example 1; trivial callback: Callback example 1 trivial callback. * Callback example 2; check option order: Callback example 2 check option order. * Callback example 3; check option order (generalized): Callback example 3 check option order generalized. * Callback example 4; check arbitrary condition: Callback example 4 check arbitrary condition. * Callback example 5; fixed arguments: Callback example 5 fixed arguments. * Callback example 6; variable arguments: Callback example 6 variable arguments. Extending optparse * Adding new types:: * Adding new actions:: imp — Access the import internals * Examples: Examples<33>. Undocumented Modules * Platform specific modules:: Extending and Embedding the Python Interpreter * Recommended third party tools:: * Creating extensions without third party tools:: * Embedding the CPython runtime in a larger application:: Creating extensions without third party tools * Extending Python with C or C++:: * Defining Extension Types; Tutorial: Defining Extension Types Tutorial. * Defining Extension Types; Assorted Topics: Defining Extension Types Assorted Topics. * Building C and C++ Extensions:: * Building C and C++ Extensions on Windows:: Extending Python with C or C++ * A Simple Example:: * Intermezzo; Errors and Exceptions: Intermezzo Errors and Exceptions. * Back to the Example:: * The Module’s Method Table and Initialization Function:: * Compilation and Linkage:: * Calling Python Functions from C:: * Extracting Parameters in Extension Functions:: * Keyword Parameters for Extension Functions:: * Building Arbitrary Values:: * Reference Counts:: * Writing Extensions in C++:: * Providing a C API for an Extension Module:: Reference Counts * Reference Counting in Python:: * Ownership Rules:: * Thin Ice:: * NULL Pointers:: Defining Extension Types: Tutorial * The Basics:: * Adding data and methods to the Basic example:: * Providing finer control over data attributes:: * Supporting cyclic garbage collection:: * Subclassing other types:: Defining Extension Types: Assorted Topics * Finalization and De-allocation:: * Object Presentation:: * Attribute Management:: * Object Comparison:: * Abstract Protocol Support:: * Weak Reference Support:: * More Suggestions:: Attribute Management * Generic Attribute Management:: * Type-specific Attribute Management:: Building C and C++ Extensions * Building C and C++ Extensions with distutils:: * Distributing your extension modules:: Building C and C++ Extensions on Windows * A Cookbook Approach:: * Differences Between Unix and Windows:: * Using DLLs in Practice:: Embedding the CPython runtime in a larger application * Embedding Python in Another Application:: Embedding Python in Another Application * Very High Level Embedding:: * Beyond Very High Level Embedding; An overview: Beyond Very High Level Embedding An overview. * Pure Embedding:: * Extending Embedded Python:: * Embedding Python in C++:: * Compiling and Linking under Unix-like systems:: Python/C API Reference Manual * Introduction: Introduction<13>. * Stable Application Binary Interface:: * The Very High Level Layer:: * Reference Counting:: * Exception Handling:: * Utilities: Utilities<2>. * Abstract Objects Layer:: * Concrete Objects Layer:: * Initialization, Finalization, and Threads: Initialization Finalization and Threads. * Python Initialization Configuration:: * Memory Management:: * Object Implementation Support:: * API and ABI Versioning:: Introduction * Coding standards:: * Include Files:: * Useful macros:: * Objects, Types and Reference Counts: Objects Types and Reference Counts. * Exceptions: Exceptions<18>. * Embedding Python: Embedding Python<2>. * Debugging Builds:: Objects, Types and Reference Counts * Reference Counts: Reference Counts<2>. * Types:: Reference Counts * Reference Count Details:: Exception Handling * Printing and clearing:: * Raising exceptions:: * Issuing warnings:: * Querying the error indicator:: * Signal Handling: Signal Handling<2>. * Exception Classes:: * Exception Objects:: * Unicode Exception Objects:: * Recursion Control:: * Standard Exceptions:: * Standard Warning Categories:: Utilities * Operating System Utilities:: * System Functions:: * Process Control:: * Importing Modules: Importing Modules<2>. * Data marshalling support:: * Parsing arguments and building values:: * String conversion and formatting:: * Reflection:: * Codec registry and support functions:: Parsing arguments and building values * Parsing arguments: Parsing arguments<3>. * Building values:: Parsing arguments * Strings and buffers:: * Numbers: Numbers<2>. * Other objects:: * API Functions:: Codec registry and support functions * Codec lookup API:: * Registry API for Unicode encoding error handlers:: Abstract Objects Layer * Object Protocol:: * Number Protocol:: * Sequence Protocol:: * Mapping Protocol:: * Iterator Protocol:: * Buffer Protocol:: * Old Buffer Protocol:: Buffer Protocol * Buffer structure:: * Buffer request types:: * Complex arrays:: * Buffer-related functions:: Buffer request types * request-independent fields:: * readonly, format: readonly format. * shape, strides, suboffsets: shape strides suboffsets. * contiguity requests:: * compound requests:: Complex arrays * NumPy-style; shape and strides: NumPy-style shape and strides. * PIL-style; shape, strides and suboffsets: PIL-style shape strides and suboffsets. Concrete Objects Layer * Fundamental Objects:: * Numeric Objects:: * Sequence Objects:: * Container Objects:: * Function Objects: Function Objects<2>. * Other Objects:: Fundamental Objects * Type Objects: Type Objects<2>. * The None Object:: Type Objects * Creating Heap-Allocated Types:: Numeric Objects * Integer Objects:: * Boolean Objects:: * Floating Point Objects:: * Complex Number Objects:: Complex Number Objects * Complex Numbers as C Structures:: * Complex Numbers as Python Objects:: Sequence Objects * Bytes Objects: Bytes Objects<2>. * Byte Array Objects:: * Unicode Objects and Codecs:: * Tuple Objects:: * Struct Sequence Objects:: * List Objects:: Byte Array Objects * Type check macros:: * Direct API functions:: * Macros:: Unicode Objects and Codecs * Unicode Objects:: * Built-in Codecs:: * Methods and Slot Functions:: Unicode Objects * Unicode Type:: * Unicode Character Properties:: * Creating and accessing Unicode strings:: * Deprecated Py_UNICODE APIs:: * Locale Encoding:: * File System Encoding:: * wchar_t Support:: Built-in Codecs * Generic Codecs:: * UTF-8 Codecs:: * UTF-32 Codecs:: * UTF-16 Codecs:: * UTF-7 Codecs:: * Unicode-Escape Codecs:: * Raw-Unicode-Escape Codecs:: * Latin-1 Codecs:: * ASCII Codecs:: * Character Map Codecs:: * MBCS codecs for Windows:: * Methods & Slots:: Container Objects * Dictionary Objects:: * Set Objects:: Function Objects * Function Objects: Function Objects<3>. * Instance Method Objects:: * Method Objects: Method Objects<2>. * Cell Objects:: * Code Objects: Code Objects<2>. Other Objects * File Objects:: * Module Objects:: * Iterator Objects:: * Descriptor Objects:: * Slice Objects:: * Ellipsis Object:: * MemoryView objects:: * Weak Reference Objects: Weak Reference Objects<2>. * Capsules: Capsules<2>. * Generator Objects:: * Coroutine Objects: Coroutine Objects<2>. * Context Variables Objects:: * DateTime Objects: DateTime Objects<2>. Module Objects * Initializing C modules:: * Module lookup:: Initializing C modules * Single-phase initialization:: * Multi-phase initialization:: * Low-level module creation functions:: * Support functions:: Initialization, Finalization, and Threads * Before Python Initialization:: * Global configuration variables:: * Initializing and finalizing the interpreter:: * Process-wide parameters:: * Thread State and the Global Interpreter Lock:: * Sub-interpreter support:: * Asynchronous Notifications:: * Profiling and Tracing:: * Advanced Debugger Support:: * Thread Local Storage Support:: Thread State and the Global Interpreter Lock * Releasing the GIL from extension code:: * Non-Python created threads:: * Cautions about fork(): Cautions about fork. * High-level API:: * Low-level API:: Sub-interpreter support * Bugs and caveats:: Thread Local Storage Support * Thread Specific Storage (TSS) API: Thread Specific Storage TSS API. * Thread Local Storage (TLS) API: Thread Local Storage TLS API. Thread Specific Storage (TSS) API * Dynamic Allocation:: * Methods: Methods<4>. Python Initialization Configuration * PyWideStringList:: * PyStatus:: * PyPreConfig:: * Preinitialization with PyPreConfig:: * PyConfig:: * Initialization with PyConfig:: * Isolated Configuration:: * Python Configuration:: * Path Configuration:: * Py_RunMain(): Py_RunMain. * Multi-Phase Initialization Private Provisional API:: Memory Management * Overview: Overview<3>. * Raw Memory Interface:: * Memory Interface:: * Object allocators:: * Default Memory Allocators:: * Customize Memory Allocators:: * The pymalloc allocator:: * tracemalloc C API:: * Examples: Examples<34>. The pymalloc allocator * Customize pymalloc Arena Allocator:: Object Implementation Support * Allocating Objects on the Heap:: * Common Object Structures:: * Type Objects: Type Objects<3>. * Number Object Structures:: * Mapping Object Structures:: * Sequence Object Structures:: * Buffer Object Structures:: * Async Object Structures:: * Slot Type typedefs:: * Examples: Examples<35>. * Supporting Cyclic Garbage Collection:: Type Objects * Quick Reference:: * PyTypeObject Definition:: * PyObject Slots:: * PyVarObject Slots:: * PyTypeObject Slots:: * Heap Types:: Quick Reference * “tp slots”:: * sub-slots:: * slot typedefs:: Distributing Python Modules * Key terms:: * Open source licensing and collaboration:: * Installing the tools:: * Reading the Python Packaging User Guide:: * How do I…?:: How do I…? * … choose a name for my project?:: * … create and distribute binary extensions?:: Installing Python Modules * Key terms: Key terms<2>. * Basic usage:: * How do I …?:: * Common installation issues:: How do I …? * … install pip in versions of Python prior to Python 3.4?: … install pip in versions of Python prior to Python 3 4?. * … install packages just for the current user?:: * … install scientific Python packages?:: * … work with multiple versions of Python installed in parallel?:: Common installation issues * Installing into the system Python on Linux:: * Pip not installed:: * Installing binary extensions:: Python HOWTOs * Porting Python 2 Code to Python 3:: * Porting Extension Modules to Python 3:: * Curses Programming with Python:: * Descriptor HowTo Guide:: * Functional Programming HOWTO:: * Logging HOWTO:: * Logging Cookbook:: * Regular Expression HOWTO:: * Socket Programming HOWTO:: * Sorting HOW TO:: * Unicode HOWTO:: * HOWTO Fetch Internet Resources Using The urllib Package:: * Argparse Tutorial:: * An introduction to the ipaddress module:: * Argument Clinic How-To:: * Instrumenting CPython with DTrace and SystemTap:: Porting Python 2 Code to Python 3 * The Short Explanation:: * Details:: Details * Drop support for Python 2.6 and older: Drop support for Python 2 6 and older. * Make sure you specify the proper version support in your setup.py file: Make sure you specify the proper version support in your setup py file. * Have good test coverage:: * Learn the differences between Python 2 & 3:: * Update your code:: * Prevent compatibility regressions:: * Check which dependencies block your transition:: * Update your setup.py file to denote Python 3 compatibility: Update your setup py file to denote Python 3 compatibility. * Use continuous integration to stay compatible:: * Consider using optional static type checking:: Update your code * Division:: * Text versus binary data:: * Use feature detection instead of version detection:: Curses Programming with Python * What is curses?:: * Starting and ending a curses application:: * Windows and Pads:: * Displaying Text:: * User Input:: * For More Information:: What is curses? * The Python curses module:: Displaying Text * Attributes and Color:: Descriptor HowTo Guide * Abstract:: * Definition and Introduction:: * Descriptor Protocol:: * Invoking Descriptors: Invoking Descriptors<2>. * Descriptor Example:: * Properties:: * Functions and Methods:: * Static Methods and Class Methods:: Functional Programming HOWTO * Introduction: Introduction<14>. * Iterators: Iterators<2>. * Generator expressions and list comprehensions:: * Generators: Generators<2>. * Built-in functions:: * The itertools module:: * The functools module:: * Small functions and the lambda expression:: * Revision History and Acknowledgements:: * References: References<2>. Introduction * Formal provability:: * Modularity:: * Ease of debugging and testing:: * Composability:: Iterators * Data Types That Support Iterators:: Generators * Passing values into a generator:: The itertools module * Creating new iterators:: * Calling functions on elements:: * Selecting elements:: * Combinatoric functions:: * Grouping elements:: The functools module * The operator module:: References * General:: * Python-specific:: * Python documentation:: Logging HOWTO * Basic Logging Tutorial:: * Advanced Logging Tutorial:: * Logging Levels: Logging Levels<2>. * Useful Handlers:: * Exceptions raised during logging:: * Using arbitrary objects as messages:: * Optimization:: Basic Logging Tutorial * When to use logging:: * A simple example:: * Logging to a file:: * Logging from multiple modules:: * Logging variable data:: * Changing the format of displayed messages:: * Displaying the date/time in messages:: * Next Steps:: Advanced Logging Tutorial * Logging Flow:: * Loggers:: * Handlers:: * Formatters:: * Configuring Logging:: * What happens if no configuration is provided:: * Configuring Logging for a Library:: Logging Levels * Custom Levels:: Logging Cookbook * Using logging in multiple modules:: * Logging from multiple threads:: * Multiple handlers and formatters:: * Logging to multiple destinations:: * Configuration server example:: * Dealing with handlers that block:: * Sending and receiving logging events across a network:: * Adding contextual information to your logging output:: * Logging to a single file from multiple processes:: * Using file rotation:: * Use of alternative formatting styles:: * Customizing LogRecord:: * Subclassing QueueHandler - a ZeroMQ example:: * Subclassing QueueListener - a ZeroMQ example:: * An example dictionary-based configuration:: * Using a rotator and namer to customize log rotation processing:: * A more elaborate multiprocessing example:: * Inserting a BOM into messages sent to a SysLogHandler:: * Implementing structured logging:: * Customizing handlers with dictConfig(): Customizing handlers with dictConfig. * Using particular formatting styles throughout your application:: * Configuring filters with dictConfig(): Configuring filters with dictConfig. * Customized exception formatting:: * Speaking logging messages:: * Buffering logging messages and outputting them conditionally:: * Formatting times using UTC (GMT) via configuration: Formatting times using UTC GMT via configuration. * Using a context manager for selective logging:: * A CLI application starter template:: * A Qt GUI for logging:: Adding contextual information to your logging output * Using LoggerAdapters to impart contextual information:: * Using Filters to impart contextual information:: Using LoggerAdapters to impart contextual information * Using objects other than dicts to pass contextual information:: Logging to a single file from multiple processes * Using concurrent.futures.ProcessPoolExecutor: Using concurrent futures ProcessPoolExecutor. Using particular formatting styles throughout your application * Using LogRecord factories:: * Using custom message objects:: Regular Expression HOWTO * Introduction: Introduction<15>. * Simple Patterns:: * Using Regular Expressions:: * More Pattern Power:: * Modifying Strings:: * Common Problems:: * Feedback:: Simple Patterns * Matching Characters:: * Repeating Things:: Using Regular Expressions * Compiling Regular Expressions:: * The Backslash Plague:: * Performing Matches:: * Module-Level Functions: Module-Level Functions<2>. * Compilation Flags:: More Pattern Power * More Metacharacters:: * Grouping:: * Non-capturing and Named Groups:: * Lookahead Assertions:: Modifying Strings * Splitting Strings:: * Search and Replace:: Common Problems * Use String Methods:: * match() versus search(): match versus search. * Greedy versus Non-Greedy:: * Using re.VERBOSE: Using re VERBOSE. Socket Programming HOWTO * Sockets:: * Creating a Socket:: * Using a Socket:: * Disconnecting:: * Non-blocking Sockets:: Sockets * History:: Creating a Socket * IPC:: Using a Socket * Binary Data:: Disconnecting * When Sockets Die:: Sorting HOW TO * Sorting Basics:: * Key Functions:: * Operator Module Functions:: * Ascending and Descending:: * Sort Stability and Complex Sorts:: * The Old Way Using Decorate-Sort-Undecorate:: * The Old Way Using the cmp Parameter:: * Odd and Ends:: Unicode HOWTO * Introduction to Unicode:: * Python’s Unicode Support:: * Reading and Writing Unicode Data:: * Acknowledgements: Acknowledgements<10>. Introduction to Unicode * Definitions:: * Encodings:: * References: References<3>. Python’s Unicode Support * The String Type:: * Converting to Bytes:: * Unicode Literals in Python Source Code:: * Unicode Properties:: * Comparing Strings:: * Unicode Regular Expressions:: * References: References<4>. Reading and Writing Unicode Data * Unicode filenames:: * Tips for Writing Unicode-aware Programs:: * References: References<5>. Tips for Writing Unicode-aware Programs * Converting Between File Encodings:: * Files in an Unknown Encoding:: HOWTO Fetch Internet Resources Using The urllib Package * Introduction: Introduction<16>. * Fetching URLs:: * Handling Exceptions: Handling Exceptions<2>. * info and geturl:: * Openers and Handlers:: * Basic Authentication:: * Proxies:: * Sockets and Layers:: * Footnotes:: Fetching URLs * Data:: * Headers:: Handling Exceptions * URLError:: * HTTPError:: * Wrapping it Up:: HTTPError * Error Codes:: Wrapping it Up * Number 1:: * Number 2:: Argparse Tutorial * Concepts:: * The basics:: * Introducing Positional arguments:: * Introducing Optional arguments:: * Combining Positional and Optional arguments:: * Getting a little more advanced:: * Conclusion:: Introducing Optional arguments * Short options:: Getting a little more advanced * Conflicting options:: An introduction to the ipaddress module * Creating Address/Network/Interface objects:: * Inspecting Address/Network/Interface Objects:: * Networks as lists of Addresses:: * Comparisons: Comparisons<4>. * Using IP Addresses with other modules:: * Getting more detail when instance creation fails:: Creating Address/Network/Interface objects * A Note on IP Versions:: * IP Host Addresses:: * Defining Networks:: * Host Interfaces:: Argument Clinic How-To * The Goals Of Argument Clinic:: * Basic Concepts And Usage:: * Converting Your First Function:: * Advanced Topics:: Advanced Topics * Symbolic default values:: * Renaming the C functions and variables generated by Argument Clinic:: * Converting functions using PyArg_UnpackTuple:: * Optional Groups:: * Using real Argument Clinic converters, instead of “legacy converters”: Using real Argument Clinic converters instead of “legacy converters”. * Py_buffer:: * Advanced converters:: * Parameter default values:: * The NULL default value:: * Expressions specified as default values:: * Using a return converter:: * Cloning existing functions:: * Calling Python code:: * Using a “self converter”:: * Writing a custom converter:: * Writing a custom return converter:: * METH_O and METH_NOARGS:: * tp_new and tp_init functions:: * Changing and redirecting Clinic’s output:: * The #ifdef trick:: * Using Argument Clinic in Python files:: Instrumenting CPython with DTrace and SystemTap * Enabling the static markers:: * Static DTrace probes:: * Static SystemTap markers:: * Available static markers:: * SystemTap Tapsets:: * Examples: Examples<36>. Python Frequently Asked Questions * General Python FAQ:: * Programming FAQ:: * Design and History FAQ:: * Library and Extension FAQ:: * Extending/Embedding FAQ:: * Python on Windows FAQ:: * Graphic User Interface FAQ:: * “Why is Python Installed on my Computer?” FAQ:: General Python FAQ * General Information:: * Python in the real world:: General Information * What is Python?:: * What is the Python Software Foundation?:: * Are there copyright restrictions on the use of Python?:: * Why was Python created in the first place?:: * What is Python good for?:: * How does the Python version numbering scheme work?:: * How do I obtain a copy of the Python source?:: * How do I get documentation on Python?:: * I’ve never programmed before. Is there a Python tutorial?: I’ve never programmed before Is there a Python tutorial?. * Is there a newsgroup or mailing list devoted to Python?:: * How do I get a beta test version of Python?:: * How do I submit bug reports and patches for Python?:: * Are there any published articles about Python that I can reference?:: * Are there any books on Python?:: * Where in the world is www.python.org located?: Where in the world is www python org located?. * Why is it called Python?:: * Do I have to like “Monty Python’s Flying Circus”?:: Python in the real world * How stable is Python?:: * How many people are using Python?:: * Have any significant projects been done in Python?:: * What new developments are expected for Python in the future?:: * Is it reasonable to propose incompatible changes to Python?:: * Is Python a good language for beginning programmers?:: Programming FAQ * General Questions:: * Core Language:: * Numbers and strings:: * Performance: Performance<4>. * Sequences (Tuples/Lists): Sequences Tuples/Lists. * Objects:: * Modules: Modules<3>. General Questions * Is there a source code level debugger with breakpoints, single-stepping, etc.?: Is there a source code level debugger with breakpoints single-stepping etc ?. * Are there tools to help find bugs or perform static analysis?:: * How can I create a stand-alone binary from a Python script?:: * Are there coding standards or a style guide for Python programs?:: Core Language * Why am I getting an UnboundLocalError when the variable has a value?:: * What are the rules for local and global variables in Python?:: * Why do lambdas defined in a loop with different values all return the same result?:: * How do I share global variables across modules?:: * What are the “best practices” for using import in a module?:: * Why are default values shared between objects?:: * How can I pass optional or keyword parameters from one function to another?:: * What is the difference between arguments and parameters?:: * Why did changing list ‘y’ also change list ‘x’?:: * How do I write a function with output parameters (call by reference)?: How do I write a function with output parameters call by reference ?. * How do you make a higher order function in Python?:: * How do I copy an object in Python?:: * How can I find the methods or attributes of an object?:: * How can my code discover the name of an object?:: * What’s up with the comma operator’s precedence?:: * Is there an equivalent of C’s “?;” ternary operator?: Is there an equivalent of C’s “? ” ternary operator?. * Is it possible to write obfuscated one-liners in Python?:: * What does the slash(/) in the parameter list of a function mean?: What does the slash / in the parameter list of a function mean?. Numbers and strings * How do I specify hexadecimal and octal integers?:: * Why does -22 // 10 return -3?:: * How do I convert a string to a number?:: * How do I convert a number to a string?:: * How do I modify a string in place?:: * How do I use strings to call functions/methods?:: * Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings?: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?. * Is there a scanf() or sscanf() equivalent?: Is there a scanf or sscanf equivalent?. * What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?:: Performance * My program is too slow. How do I speed it up?: My program is too slow How do I speed it up?. * What is the most efficient way to concatenate many strings together?:: Sequences (Tuples/Lists) * How do I convert between tuples and lists?:: * What’s a negative index?:: * How do I iterate over a sequence in reverse order?:: * How do you remove duplicates from a list?:: * How do you remove multiple items from a list:: * How do you make an array in Python?:: * How do I create a multidimensional list?:: * How do I apply a method to a sequence of objects?:: * Why does a_tuple[i] += [‘item’] raise an exception when the addition works?:: * I want to do a complicated sort; can you do a Schwartzian Transform in Python?: I want to do a complicated sort can you do a Schwartzian Transform in Python?. * How can I sort one list by values from another list?:: Objects * What is a class?:: * What is a method?:: * What is self?:: * How do I check if an object is an instance of a given class or of a subclass of it?:: * What is delegation?:: * How do I call a method defined in a base class from a derived class that overrides it?:: * How can I organize my code to make it easier to change the base class?:: * How do I create static class data and static class methods?:: * How can I overload constructors (or methods) in Python?: How can I overload constructors or methods in Python?. * I try to use __spam and I get an error about _SomeClassName__spam.: I try to use __spam and I get an error about _SomeClassName__spam. * My class defines __del__ but it is not called when I delete the object.: My class defines __del__ but it is not called when I delete the object. * How do I get a list of all instances of a given class?:: * Why does the result of id() appear to be not unique?: Why does the result of id appear to be not unique?. Modules * How do I create a .pyc file?: How do I create a pyc file?. * How do I find the current module name?:: * How can I have modules that mutually import each other?:: * __import__(‘x.y.z’) returns ; how do I get z?: __import__ ‘x y z’ returns ; how do I get z?. * When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?: When I edit an imported module and reimport it the changes don’t show up Why does this happen?. Design and History FAQ * Why does Python use indentation for grouping of statements?:: * Why am I getting strange results with simple arithmetic operations?:: * Why are floating-point calculations so inaccurate?:: * Why are Python strings immutable?:: * Why must ‘self’ be used explicitly in method definitions and calls?:: * Why can’t I use an assignment in an expression?:: * Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?: Why does Python use methods for some functionality e g list index but functions for other e g len list ?. * Why is join() a string method instead of a list or tuple method?: Why is join a string method instead of a list or tuple method?. * How fast are exceptions?:: * Why isn’t there a switch or case statement in Python?:: * Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?:: * Why can’t lambda expressions contain statements?:: * Can Python be compiled to machine code, C or some other language?: Can Python be compiled to machine code C or some other language?. * How does Python manage memory?:: * Why doesn’t CPython use a more traditional garbage collection scheme?:: * Why isn’t all memory freed when CPython exits?:: * Why are there separate tuple and list data types?:: * How are lists implemented in CPython?:: * How are dictionaries implemented in CPython?:: * Why must dictionary keys be immutable?:: * Why doesn’t list.sort() return the sorted list?: Why doesn’t list sort return the sorted list?. * How do you specify and enforce an interface spec in Python?:: * Why is there no goto?:: * Why can’t raw strings (r-strings) end with a backslash?: Why can’t raw strings r-strings end with a backslash?. * Why doesn’t Python have a “with” statement for attribute assignments?:: * Why are colons required for the if/while/def/class statements?:: * Why does Python allow commas at the end of lists and tuples?:: Library and Extension FAQ * General Library Questions:: * Common tasks:: * Threads:: * Input and Output: Input and Output<2>. * Network/Internet Programming:: * Databases:: * Mathematics and Numerics:: General Library Questions * How do I find a module or application to perform task X?:: * Where is the math.py (socket.py, regex.py, etc.) source file?: Where is the math py socket py regex py etc source file?. * How do I make a Python script executable on Unix?:: * Is there a curses/termcap package for Python?:: * Is there an equivalent to C’s onexit() in Python?: Is there an equivalent to C’s onexit in Python?. * Why don’t my signal handlers work?:: Common tasks * How do I test a Python program or component?:: * How do I create documentation from doc strings?:: * How do I get a single keypress at a time?:: Threads * How do I program using threads?:: * None of my threads seem to run; why?: None of my threads seem to run why?. * How do I parcel out work among a bunch of worker threads?:: * What kinds of global value mutation are thread-safe?:: * Can’t we get rid of the Global Interpreter Lock?:: Input and Output * How do I delete a file? (And other file questions…): How do I delete a file? And other file questions…. * How do I copy a file?:: * How do I read (or write) binary data?: How do I read or write binary data?. * I can’t seem to use os.read() on a pipe created with os.popen(); why?: I can’t seem to use os read on a pipe created with os popen ; why?. * How do I access the serial (RS232) port?: How do I access the serial RS232 port?. * Why doesn’t closing sys.stdout (stdin, stderr) really close it?: Why doesn’t closing sys stdout stdin stderr really close it?. Network/Internet Programming * What WWW tools are there for Python?:: * How can I mimic CGI form submission (METHOD=POST)?: How can I mimic CGI form submission METHOD=POST ?. * What module should I use to help with generating HTML?:: * How do I send mail from a Python script?:: * How do I avoid blocking in the connect() method of a socket?: How do I avoid blocking in the connect method of a socket?. Databases * Are there any interfaces to database packages in Python?:: * How do you implement persistent objects in Python?:: Mathematics and Numerics * How do I generate random numbers in Python?:: Extending/Embedding FAQ * Can I create my own functions in C?:: * Can I create my own functions in C++?:: * Writing C is hard; are there any alternatives?:: * How can I execute arbitrary Python statements from C?:: * How can I evaluate an arbitrary Python expression from C?:: * How do I extract C values from a Python object?:: * How do I use Py_BuildValue() to create a tuple of arbitrary length?: How do I use Py_BuildValue to create a tuple of arbitrary length?. * How do I call an object’s method from C?:: * How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?. * How do I access a module written in Python from C?:: * How do I interface to C++ objects from Python?:: * I added a module using the Setup file and the make fails; why?:: * How do I debug an extension?:: * I want to compile a Python module on my Linux system, but some files are missing. Why?: I want to compile a Python module on my Linux system but some files are missing Why?. * How do I tell “incomplete input” from “invalid input”?:: * How do I find undefined g++ symbols __builtin_new or __pure_virtual?:: * Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?. Python on Windows FAQ * How do I run a Python program under Windows?:: * How do I make Python scripts executable?:: * Why does Python sometimes take so long to start?:: * How do I make an executable from a Python script?:: * Is a *.pyd file the same as a DLL?: Is a * pyd file the same as a DLL?. * How can I embed Python into a Windows application?:: * How do I keep editors from inserting tabs into my Python source?:: * How do I check for a keypress without blocking?:: Graphic User Interface FAQ * General GUI Questions:: * What platform-independent GUI toolkits exist for Python?:: * What platform-specific GUI toolkits exist for Python?:: * Tkinter questions:: What platform-independent GUI toolkits exist for Python? * Tkinter:: * wxWidgets:: * Qt:: * Gtk+:: * Kivy:: * FLTK:: * OpenGL:: Tkinter questions * How do I freeze Tkinter applications?:: * Can I have Tk events handled while waiting for I/O?:: * I can’t get key bindings to work in Tkinter; why?: I can’t get key bindings to work in Tkinter why?. “Why is Python Installed on my Computer?” FAQ * What is Python?: What is Python?<2>. * Why is Python installed on my machine?:: * Can I delete Python?:: About these documents * Contributors to the Python Documentation:: Dealing with Bugs * Documentation bugs:: * Using the Python issue tracker:: * Getting started contributing to Python yourself:: History and License * History of the software:: * Terms and conditions for accessing or otherwise using Python:: * Licenses and Acknowledgements for Incorporated Software:: Terms and conditions for accessing or otherwise using Python * PSF LICENSE AGREEMENT FOR PYTHON 3.8.9: PSF LICENSE AGREEMENT FOR PYTHON 3 8 9. * BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0: BEOPEN COM LICENSE AGREEMENT FOR PYTHON 2 0. * CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1: CNRI LICENSE AGREEMENT FOR PYTHON 1 6 1. * CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 2. * ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3.8.9 DOCUMENTATION: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 8 9 DOCUMENTATION. Licenses and Acknowledgements for Incorporated Software * Mersenne Twister:: * Sockets: Sockets<2>. * Asynchronous socket services:: * Cookie management:: * Execution tracing:: * UUencode and UUdecode functions:: * XML Remote Procedure Calls:: * test_epoll:: * Select kqueue:: * SipHash24:: * strtod and dtoa:: * OpenSSL:: * expat:: * libffi:: * zlib: zlib<3>. * cfuhash:: * libmpdec:: * W3C C14N test suite:: Distributing Python Modules (Legacy version) * An Introduction to Distutils:: * Writing the Setup Script:: * Writing the Setup Configuration File:: * Creating a Source Distribution:: * Creating Built Distributions:: * Distutils Examples:: * Extending Distutils:: * Command Reference:: * API Reference:: An Introduction to Distutils * Concepts & Terminology:: * A Simple Example: A Simple Example<2>. * General Python terminology:: * Distutils-specific terminology:: Writing the Setup Script * Listing whole packages:: * Listing individual modules:: * Describing extension modules:: * Relationships between Distributions and Packages:: * Installing Scripts:: * Installing Package Data:: * Installing Additional Files:: * Additional meta-data:: * Debugging the setup script:: Describing extension modules * Extension names and packages:: * Extension source files:: * Preprocessor options:: * Library options:: * Other options:: Creating a Source Distribution * Specifying the files to distribute:: * Manifest-related options:: Creating Built Distributions * Creating RPM packages:: * Creating Windows Installers:: * Cross-compiling on Windows:: * Vista User Access Control (UAC): Vista User Access Control UAC. Cross-compiling on Windows * The Postinstallation script:: Distutils Examples * Pure Python distribution (by module): Pure Python distribution by module. * Pure Python distribution (by package): Pure Python distribution by package. * Single extension module:: * Checking a package:: * Reading the metadata:: Extending Distutils * Integrating new commands:: * Adding new distribution types:: Command Reference * Installing modules; the install command family: Installing modules the install command family. * Creating a source distribution; the sdist command: Creating a source distribution the sdist command. Installing modules: the install command family * install_data:: * install_scripts:: API Reference * distutils.core — Core Distutils functionality: distutils core — Core Distutils functionality. * distutils.ccompiler — CCompiler base class: distutils ccompiler — CCompiler base class. * distutils.unixccompiler — Unix C Compiler: distutils unixccompiler — Unix C Compiler. * distutils.msvccompiler — Microsoft Compiler: distutils msvccompiler — Microsoft Compiler. * distutils.bcppcompiler — Borland Compiler: distutils bcppcompiler — Borland Compiler. * distutils.cygwincompiler — Cygwin Compiler: distutils cygwincompiler — Cygwin Compiler. * distutils.archive_util — Archiving utilities: distutils archive_util — Archiving utilities. * distutils.dep_util — Dependency checking: distutils dep_util — Dependency checking. * distutils.dir_util — Directory tree operations: distutils dir_util — Directory tree operations. * distutils.file_util — Single file operations: distutils file_util — Single file operations. * distutils.util — Miscellaneous other utility functions: distutils util — Miscellaneous other utility functions. * distutils.dist — The Distribution class: distutils dist — The Distribution class. * distutils.extension — The Extension class: distutils extension — The Extension class. * distutils.debug — Distutils debug mode: distutils debug — Distutils debug mode. * distutils.errors — Distutils exceptions: distutils errors — Distutils exceptions. * distutils.fancy_getopt — Wrapper around the standard getopt module: distutils fancy_getopt — Wrapper around the standard getopt module. * distutils.filelist — The FileList class: distutils filelist — The FileList class. * distutils.log — Simple PEP 282-style logging: distutils log — Simple PEP 282-style logging. * distutils.spawn — Spawn a sub-process: distutils spawn — Spawn a sub-process. * distutils.sysconfig — System configuration information: distutils sysconfig — System configuration information. * distutils.text_file — The TextFile class: distutils text_file — The TextFile class. * distutils.version — Version number classes: distutils version — Version number classes. * distutils.cmd — Abstract base class for Distutils commands: distutils cmd — Abstract base class for Distutils commands. * Creating a new Distutils command:: * distutils.command — Individual Distutils commands: distutils command — Individual Distutils commands. * distutils.command.bdist — Build a binary installer: distutils command bdist — Build a binary installer. * distutils.command.bdist_packager — Abstract base class for packagers: distutils command bdist_packager — Abstract base class for packagers. * distutils.command.bdist_dumb — Build a “dumb” installer: distutils command bdist_dumb — Build a “dumb” installer. * distutils.command.bdist_msi — Build a Microsoft Installer binary package: distutils command bdist_msi — Build a Microsoft Installer binary package. * distutils.command.bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM. * distutils.command.bdist_wininst — Build a Windows installer: distutils command bdist_wininst — Build a Windows installer. * distutils.command.sdist — Build a source distribution: distutils command sdist — Build a source distribution. * distutils.command.build — Build all files of a package: distutils command build — Build all files of a package. * distutils.command.build_clib — Build any C libraries in a package: distutils command build_clib — Build any C libraries in a package. * distutils.command.build_ext — Build any extensions in a package: distutils command build_ext — Build any extensions in a package. * distutils.command.build_py — Build the .py/.pyc files of a package: distutils command build_py — Build the py/ pyc files of a package. * distutils.command.build_scripts — Build the scripts of a package: distutils command build_scripts — Build the scripts of a package. * distutils.command.clean — Clean a package build area: distutils command clean — Clean a package build area. * distutils.command.config — Perform package configuration: distutils command config — Perform package configuration. * distutils.command.install — Install a package: distutils command install — Install a package. * distutils.command.install_data — Install data files from a package: distutils command install_data — Install data files from a package. * distutils.command.install_headers — Install C/C++ header files from a package: distutils command install_headers — Install C/C++ header files from a package. * distutils.command.install_lib — Install library files from a package: distutils command install_lib — Install library files from a package. * distutils.command.install_scripts — Install script files from a package: distutils command install_scripts — Install script files from a package. * distutils.command.register — Register a module with the Python Package Index: distutils command register — Register a module with the Python Package Index. * distutils.command.check — Check the meta-data of a package: distutils command check — Check the meta-data of a package. Installing Python Modules (Legacy version) * Introduction: Introduction<17>. * Standard Build and Install:: * Alternate Installation:: * Custom Installation:: * Distutils Configuration Files:: * Building Extensions; Tips and Tricks: Building Extensions Tips and Tricks. Introduction * Distutils based source distributions:: Standard Build and Install * Platform variations:: * Splitting the job up:: * How building works:: * How installation works:: Alternate Installation * Alternate installation; the user scheme: Alternate installation the user scheme. * Alternate installation; the home scheme: Alternate installation the home scheme. * Alternate installation; Unix (the prefix scheme): Alternate installation Unix the prefix scheme. * Alternate installation; Windows (the prefix scheme): Alternate installation Windows the prefix scheme. Custom Installation * Modifying Python’s Search Path:: Distutils Configuration Files * Location and names of config files:: * Syntax of config files:: Building Extensions: Tips and Tricks * Tweaking compiler/linker flags:: * Using non-Microsoft compilers on Windows:: Using non-Microsoft compilers on Windows * Borland/CodeGear C++:: * GNU C / Cygwin / MinGW:: GNU C / Cygwin / MinGW * Older Versions of Python and MinGW::  File: python.info, Node: What’s New in Python, Next: The Python Tutorial, Prev: Top, Up: Top 1 What’s New in Python ********************** The “What’s New in Python” series of essays takes tours through the most important changes between major Python versions. They are a “must read” for anyone wishing to stay up-to-date after a new release. * Menu: * What’s New In Python 3.8: What’s New In Python 3 8. * What’s New In Python 3.7: What’s New In Python 3 7. * What’s New In Python 3.6: What’s New In Python 3 6. * What’s New In Python 3.5: What’s New In Python 3 5. * What’s New In Python 3.4: What’s New In Python 3 4. * What’s New In Python 3.3: What’s New In Python 3 3. * What’s New In Python 3.2: What’s New In Python 3 2. * What’s New In Python 3.1: What’s New In Python 3 1. * What’s New In Python 3.0: What’s New In Python 3 0. * What’s New in Python 2.7: What’s New in Python 2 7. * What’s New in Python 2.6: What’s New in Python 2 6. * What’s New in Python 2.5: What’s New in Python 2 5. * What’s New in Python 2.4: What’s New in Python 2 4. * What’s New in Python 2.3: What’s New in Python 2 3. * What’s New in Python 2.2: What’s New in Python 2 2. * What’s New in Python 2.1: What’s New in Python 2 1. * What’s New in Python 2.0: What’s New in Python 2 0. * Changelog::  File: python.info, Node: What’s New In Python 3 8, Next: What’s New In Python 3 7, Up: What’s New in Python 1.1 What’s New In Python 3.8 ============================ Editor: Raymond Hettinger This article explains the new features in Python 3.8, compared to 3.7. For full details, see the *note changelog: 14c. Python 3.8 was released on October 14th, 2019. * Menu: * Summary – Release highlights:: * New Features:: * Other Language Changes:: * New Modules:: * Improved Modules:: * Optimizations:: * Build and C API Changes:: * Deprecated:: * API and Feature Removals:: * Porting to Python 3.8: Porting to Python 3 8. * Notable changes in Python 3.8.1: Notable changes in Python 3 8 1. * Notable changes in Python 3.8.2: Notable changes in Python 3 8 2. * Notable changes in Python 3.8.3: Notable changes in Python 3 8 3. * Notable changes in Python 3.8.8: Notable changes in Python 3 8 8. * Notable changes in Python 3.8.9: Notable changes in Python 3 8 9.  File: python.info, Node: Summary – Release highlights, Next: New Features, Up: What’s New In Python 3 8 1.1.1 Summary – Release highlights ----------------------------------  File: python.info, Node: New Features, Next: Other Language Changes, Prev: Summary – Release highlights, Up: What’s New In Python 3 8 1.1.2 New Features ------------------ * Menu: * Assignment expressions:: * Positional-only parameters:: * Parallel filesystem cache for compiled bytecode files:: * Debug build uses the same ABI as release build:: * f-strings support = for self-documenting expressions and debugging:: * PEP 578; Python Runtime Audit Hooks: PEP 578 Python Runtime Audit Hooks. * PEP 587; Python Initialization Configuration: PEP 587 Python Initialization Configuration. * Vectorcall; a fast calling protocol for CPython: Vectorcall a fast calling protocol for CPython. * Pickle protocol 5 with out-of-band data buffers::  File: python.info, Node: Assignment expressions, Next: Positional-only parameters, Up: New Features 1.1.2.1 Assignment expressions .............................. There is new syntax ‘:=’ that assigns values to variables as part of a larger expression. It is affectionately known as “the walrus operator” due to its resemblance to the eyes and tusks of a walrus(1). In this example, the assignment expression helps avoid calling *note len(): 150. twice: if (n := len(a)) > 10: print(f"List is too long ({n} elements, expected <= 10)") A similar benefit arises during regular expression matching where match objects are needed twice, once to test whether a match occurred and another to extract a subgroup: discount = 0.0 if (mo := re.search(r'(\d+)% discount', advertisement)): discount = float(mo.group(1)) / 100.0 The operator is also useful with while-loops that compute a value to test loop termination and then need that same value again in the body of the loop: # Loop over fixed length blocks while (block := f.read(256)) != '': process(block) Another motivating use case arises in list comprehensions where a value computed in a filtering condition is also needed in the expression body: [clean_name.title() for name in names if (clean_name := normalize('NFC', name)) in allowed_names] Try to limit use of the walrus operator to clean cases that reduce complexity and improve readability. See PEP 572(2) for a full description. (Contributed by Emily Morehouse in bpo-35224(3).) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Walrus#/media/File:Pacific_Walrus_-_Bull_(8247646168).jpg (2) https://www.python.org/dev/peps/pep-0572 (3) https://bugs.python.org/issue35224  File: python.info, Node: Positional-only parameters, Next: Parallel filesystem cache for compiled bytecode files, Prev: Assignment expressions, Up: New Features 1.1.2.2 Positional-only parameters .................................. There is a new function parameter syntax ‘/’ to indicate that some function parameters must be specified positionally and cannot be used as keyword arguments. This is the same notation shown by ‘help()’ for C functions annotated with Larry Hastings’ Argument Clinic(1) tool. In the following example, parameters `a' and `b' are positional-only, while `c' or `d' can be positional or keyword, and `e' or `f' are required to be keywords: def f(a, b, /, c, d, *, e, f): print(a, b, c, d, e, f) The following is a valid call: f(10, 20, 30, d=40, e=50, f=60) However, these are invalid calls: f(10, b=20, c=30, d=40, e=50, f=60) # b cannot be a keyword argument f(10, 20, 30, 40, 50, f=60) # e must be a keyword argument One use case for this notation is that it allows pure Python functions to fully emulate behaviors of existing C coded functions. For example, the built-in *note divmod(): 152. function does not accept keyword arguments: def divmod(a, b, /): "Emulate the built in divmod() function" return (a // b, a % b) Another use case is to preclude keyword arguments when the parameter name is not helpful. For example, the builtin *note len(): 150. function has the signature ‘len(obj, /)’. This precludes awkward calls such as: len(obj='hello') # The "obj" keyword argument impairs readability A further benefit of marking a parameter as positional-only is that it allows the parameter name to be changed in the future without risk of breaking client code. For example, in the *note statistics: f5. module, the parameter name `dist' may be changed in the future. This was made possible with the following function specification: def quantiles(dist, /, *, n=4, method='exclusive') ... Since the parameters to the left of ‘/’ are not exposed as possible keywords, the parameters names remain available for use in ‘**kwargs’: >>> def f(a, b, /, **kwargs): ... print(a, b, kwargs) ... >>> f(10, 20, a=1, b=2, c=3) # a and b are used in two ways 10 20 {'a': 1, 'b': 2, 'c': 3} This greatly simplifies the implementation of functions and methods that need to accept arbitrary keyword arguments. For example, here is an excerpt from code in the *note collections: 1e. module: class Counter(dict): def __init__(self, iterable=None, /, **kwds): # Note "iterable" is a possible keyword argument See PEP 570(2) for a full description. (Contributed by Pablo Galindo in bpo-36540(3).) ---------- Footnotes ---------- (1) https://docs.python.org/3/howto/clinic.html (2) https://www.python.org/dev/peps/pep-0570 (3) https://bugs.python.org/issue36540  File: python.info, Node: Parallel filesystem cache for compiled bytecode files, Next: Debug build uses the same ABI as release build, Prev: Positional-only parameters, Up: New Features 1.1.2.3 Parallel filesystem cache for compiled bytecode files ............................................................. The new *note PYTHONPYCACHEPREFIX: 154. setting (also available as *note -X: 155. ‘pycache_prefix’) configures the implicit bytecode cache to use a separate parallel filesystem tree, rather than the default ‘__pycache__’ subdirectories within each source directory. The location of the cache is reported in *note sys.pycache_prefix: 156. (*note None: 157. indicates the default location in ‘__pycache__’ subdirectories). (Contributed by Carl Meyer in bpo-33499(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33499  File: python.info, Node: Debug build uses the same ABI as release build, Next: f-strings support = for self-documenting expressions and debugging, Prev: Parallel filesystem cache for compiled bytecode files, Up: New Features 1.1.2.4 Debug build uses the same ABI as release build ...................................................... Python now uses the same ABI whether it’s built in release or debug mode. On Unix, when Python is built in debug mode, it is now possible to load C extensions built in release mode and C extensions built using the stable ABI. Release builds and debug builds are now ABI compatible: defining the ‘Py_DEBUG’ macro no longer implies the ‘Py_TRACE_REFS’ macro, which introduces the only ABI incompatibility. The ‘Py_TRACE_REFS’ macro, which adds the ‘sys.getobjects()’ function and the *note PYTHONDUMPREFS: 159. environment variable, can be set using the new ‘./configure --with-trace-refs’ build option. (Contributed by Victor Stinner in bpo-36465(1).) On Unix, C extensions are no longer linked to libpython except on Android and Cygwin. It is now possible for a statically linked Python to load a C extension built using a shared library Python. (Contributed by Victor Stinner in bpo-21536(2).) On Unix, when Python is built in debug mode, import now also looks for C extensions compiled in release mode and for C extensions compiled with the stable ABI. (Contributed by Victor Stinner in bpo-36722(3).) To embed Python into an application, a new ‘--embed’ option must be passed to ‘python3-config --libs --embed’ to get ‘-lpython3.8’ (link the application to libpython). To support both 3.8 and older, try ‘python3-config --libs --embed’ first and fallback to ‘python3-config --libs’ (without ‘--embed’) if the previous command fails. Add a pkg-config ‘python-3.8-embed’ module to embed Python into an application: ‘pkg-config python-3.8-embed --libs’ includes ‘-lpython3.8’. To support both 3.8 and older, try ‘pkg-config python-X.Y-embed --libs’ first and fallback to ‘pkg-config python-X.Y --libs’ (without ‘--embed’) if the previous command fails (replace ‘X.Y’ with the Python version). On the other hand, ‘pkg-config python3.8 --libs’ no longer contains ‘-lpython3.8’. C extensions must not be linked to libpython (except on Android and Cygwin, whose cases are handled by the script); this change is backward incompatible on purpose. (Contributed by Victor Stinner in bpo-36721(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36465 (2) https://bugs.python.org/issue21536 (3) https://bugs.python.org/issue36722 (4) https://bugs.python.org/issue36721  File: python.info, Node: f-strings support = for self-documenting expressions and debugging, Next: PEP 578 Python Runtime Audit Hooks, Prev: Debug build uses the same ABI as release build, Up: New Features 1.1.2.5 f-strings support ‘=’ for self-documenting expressions and debugging ............................................................................ Added an ‘=’ specifier to *note f-string: 15b.s. An f-string such as ‘f'{expr=}'’ will expand to the text of the expression, an equal sign, then the representation of the evaluated expression. For example: >>> user = 'eric_idle' >>> member_since = date(1975, 7, 31) >>> f'{user=} {member_since=}' "user='eric_idle' member_since=datetime.date(1975, 7, 31)" The usual *note f-string format specifiers: 15c. allow more control over how the result of the expression is displayed: >>> delta = date.today() - member_since >>> f'{user=!s} {delta.days=:,d}' 'user=eric_idle delta.days=16,075' The ‘=’ specifier will display the whole expression so that calculations can be shown: >>> print(f'{theta=} {cos(radians(theta))=:.3f}') theta=30 cos(radians(theta))=0.866 (Contributed by Eric V. Smith and Larry Hastings in bpo-36817(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36817  File: python.info, Node: PEP 578 Python Runtime Audit Hooks, Next: PEP 587 Python Initialization Configuration, Prev: f-strings support = for self-documenting expressions and debugging, Up: New Features 1.1.2.6 PEP 578: Python Runtime Audit Hooks ........................................... The PEP adds an Audit Hook and Verified Open Hook. Both are available from Python and native code, allowing applications and frameworks written in pure Python code to take advantage of extra notifications, while also allowing embedders or system administrators to deploy builds of Python where auditing is always enabled. See PEP 578(1) for full details. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0578  File: python.info, Node: PEP 587 Python Initialization Configuration, Next: Vectorcall a fast calling protocol for CPython, Prev: PEP 578 Python Runtime Audit Hooks, Up: New Features 1.1.2.7 PEP 587: Python Initialization Configuration .................................................... The PEP 587(1) adds a new C API to configure the Python Initialization providing finer control on the whole configuration and better error reporting. New structures: * *note PyConfig: 15f. * *note PyPreConfig: 160. * *note PyStatus: 161. * *note PyWideStringList: 162. New functions: * *note PyConfig_Clear(): 163. * *note PyConfig_InitIsolatedConfig(): 164. * *note PyConfig_InitPythonConfig(): 165. * *note PyConfig_Read(): 166. * *note PyConfig_SetArgv(): 167. * *note PyConfig_SetBytesArgv(): 168. * *note PyConfig_SetBytesString(): 169. * *note PyConfig_SetString(): 16a. * *note PyPreConfig_InitIsolatedConfig(): 16b. * *note PyPreConfig_InitPythonConfig(): 16c. * *note PyStatus_Error(): 16d. * *note PyStatus_Exception(): 16e. * *note PyStatus_Exit(): 16f. * *note PyStatus_IsError(): 170. * *note PyStatus_IsExit(): 171. * *note PyStatus_NoMemory(): 172. * *note PyStatus_Ok(): 173. * *note PyWideStringList_Append(): 174. * *note PyWideStringList_Insert(): 175. * *note Py_BytesMain(): 176. * *note Py_ExitStatusException(): 177. * *note Py_InitializeFromConfig(): 178. * *note Py_PreInitialize(): 179. * *note Py_PreInitializeFromArgs(): 17a. * *note Py_PreInitializeFromBytesArgs(): 17b. * *note Py_RunMain(): 17c. This PEP also adds ‘_PyRuntimeState.preconfig’ (*note PyPreConfig: 160. type) and ‘PyInterpreterState.config’ (*note PyConfig: 15f. type) fields to these internal structures. ‘PyInterpreterState.config’ becomes the new reference configuration, replacing global configuration variables and other private variables. See *note Python Initialization Configuration: 17d. for the documentation. See PEP 587(2) for a full description. (Contributed by Victor Stinner in bpo-36763(3).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0587 (2) https://www.python.org/dev/peps/pep-0587 (3) https://bugs.python.org/issue36763  File: python.info, Node: Vectorcall a fast calling protocol for CPython, Next: Pickle protocol 5 with out-of-band data buffers, Prev: PEP 587 Python Initialization Configuration, Up: New Features 1.1.2.8 Vectorcall: a fast calling protocol for CPython ....................................................... The “vectorcall” protocol is added to the Python/C API. It is meant to formalize existing optimizations which were already done for various classes. Any extension type implementing a callable can use this protocol. This is currently provisional. The aim is to make it fully public in Python 3.9. See PEP 590(1) for a full description. (Contributed by Jeroen Demeyer and Mark Shannon in bpo-36974(2).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0590 (2) https://bugs.python.org/issue36974  File: python.info, Node: Pickle protocol 5 with out-of-band data buffers, Prev: Vectorcall a fast calling protocol for CPython, Up: New Features 1.1.2.9 Pickle protocol 5 with out-of-band data buffers ....................................................... When *note pickle: ca. is used to transfer large data between Python processes in order to take advantage of multi-core or multi-machine processing, it is important to optimize the transfer by reducing memory copies, and possibly by applying custom techniques such as data-dependent compression. The *note pickle: ca. protocol 5 introduces support for out-of-band buffers where PEP 3118(1)-compatible data can be transmitted separately from the main pickle stream, at the discretion of the communication layer. See PEP 574(2) for a full description. (Contributed by Antoine Pitrou in bpo-36785(3).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3118 (2) https://www.python.org/dev/peps/pep-0574 (3) https://bugs.python.org/issue36785  File: python.info, Node: Other Language Changes, Next: New Modules, Prev: New Features, Up: What’s New In Python 3 8 1.1.3 Other Language Changes ---------------------------- * A *note continue: 181. statement was illegal in the *note finally: 182. clause due to a problem with the implementation. In Python 3.8 this restriction was lifted. (Contributed by Serhiy Storchaka in bpo-32489(1).) * The *note bool: 183, *note int: 184, and *note fractions.Fraction: 185. types now have an *note as_integer_ratio(): 186. method like that found in *note float: 187. and *note decimal.Decimal: 188. This minor API extension makes it possible to write ‘numerator, denominator = x.as_integer_ratio()’ and have it work across multiple numeric types. (Contributed by Lisa Roach in bpo-33073(2) and Raymond Hettinger in bpo-37819(3).) * Constructors of *note int: 184, *note float: 187. and *note complex: 189. will now use the *note __index__(): 18a. special method, if available and the corresponding method *note __int__(): 18b, *note __float__(): 18c. or *note __complex__(): 18d. is not available. (Contributed by Serhiy Storchaka in bpo-20092(4).) * Added support of ‘\N{name}’ escapes in *note regular expressions: dd.: >>> notice = 'Copyright © 2019' >>> copyright_year_pattern = re.compile(r'\N{copyright sign}\s*(\d{4})') >>> int(copyright_year_pattern.search(notice).group(1)) 2019 (Contributed by Jonathan Eunice and Serhiy Storchaka in bpo-30688(5).) * Dict and dictviews are now iterable in reversed insertion order using *note reversed(): 18e. (Contributed by Rémi Lapeyre in bpo-33462(6).) * The syntax allowed for keyword names in function calls was further restricted. In particular, ‘f((keyword)=arg)’ is no longer allowed. It was never intended to permit more than a bare name on the left-hand side of a keyword argument assignment term. (Contributed by Benjamin Peterson in bpo-34641(7).) * Generalized iterable unpacking in *note yield: 18f. and *note return: 190. statements no longer requires enclosing parentheses. This brings the `yield' and `return' syntax into better agreement with normal assignment syntax: >>> def parse(family): lastname, *members = family.split() return lastname.upper(), *members >>> parse('simpsons homer marge bart lisa sally') ('SIMPSONS', 'homer', 'marge', 'bart', 'lisa', 'sally') (Contributed by David Cuthbert and Jordan Chapman in bpo-32117(8).) * When a comma is missed in code such as ‘[(10, 20) (30, 40)]’, the compiler displays a *note SyntaxWarning: 191. with a helpful suggestion. This improves on just having a *note TypeError: 192. indicating that the first tuple was not callable. (Contributed by Serhiy Storchaka in bpo-15248(9).) * Arithmetic operations between subclasses of *note datetime.date: 193. or *note datetime.datetime: 194. and *note datetime.timedelta: 195. objects now return an instance of the subclass, rather than the base class. This also affects the return type of operations whose implementation (directly or indirectly) uses *note datetime.timedelta: 195. arithmetic, such as *note astimezone(): 196. (Contributed by Paul Ganssle in bpo-32417(10).) * When the Python interpreter is interrupted by Ctrl-C (SIGINT) and the resulting *note KeyboardInterrupt: 197. exception is not caught, the Python process now exits via a SIGINT signal or with the correct exit code such that the calling process can detect that it died due to a Ctrl-C. Shells on POSIX and Windows use this to properly terminate scripts in interactive sessions. (Contributed by Google via Gregory P. Smith in bpo-1054041(11).) * Some advanced styles of programming require updating the *note types.CodeType: 198. object for an existing function. Since code objects are immutable, a new code object needs to be created, one that is modeled on the existing code object. With 19 parameters, this was somewhat tedious. Now, the new ‘replace()’ method makes it possible to create a clone with a few altered parameters. Here’s an example that alters the *note statistics.mean(): 199. function to prevent the `data' parameter from being used as a keyword argument: >>> from statistics import mean >>> mean(data=[10, 20, 90]) 40 >>> mean.__code__ = mean.__code__.replace(co_posonlyargcount=1) >>> mean(data=[10, 20, 90]) Traceback (most recent call last): ... TypeError: mean() got some positional-only arguments passed as keyword arguments: 'data' (Contributed by Victor Stinner in bpo-37032(12).) * For integers, the three-argument form of the *note pow(): 19a. function now permits the exponent to be negative in the case where the base is relatively prime to the modulus. It then computes a modular inverse to the base when the exponent is ‘-1’, and a suitable power of that inverse for other negative exponents. For example, to compute the modular multiplicative inverse(13) of 38 modulo 137, write: >>> pow(38, -1, 137) 119 >>> 119 * 38 % 137 1 Modular inverses arise in the solution of linear Diophantine equations(14). For example, to find integer solutions for ‘4258𝑥 + 147𝑦 = 369’, first rewrite as ‘4258𝑥 ≡ 369 (mod 147)’ then solve: >>> x = 369 * pow(4258, -1, 147) % 147 >>> y = (4258 * x - 369) // -147 >>> 4258 * x + 147 * y 369 (Contributed by Mark Dickinson in bpo-36027(15).) * Dict comprehensions have been synced-up with dict literals so that the key is computed first and the value second: >>> # Dict comprehension >>> cast = {input('role? '): input('actor? ') for i in range(2)} role? King Arthur actor? Chapman role? Black Knight actor? Cleese >>> # Dict literal >>> cast = {input('role? '): input('actor? ')} role? Sir Robin actor? Eric Idle The guaranteed execution order is helpful with assignment expressions because variables assigned in the key expression will be available in the value expression: >>> names = ['Martin von Löwis', 'Łukasz Langa', 'Walter Dörwald'] >>> {(n := normalize('NFC', name)).casefold() : n for name in names} {'martin von löwis': 'Martin von Löwis', 'łukasz langa': 'Łukasz Langa', 'walter dörwald': 'Walter Dörwald'} (Contributed by Jörn Heissler in bpo-35224(16).) * The *note object.__reduce__(): 19b. method can now return a tuple from two to six elements long. Formerly, five was the limit. The new, optional sixth element is a callable with a ‘(obj, state)’ signature. This allows the direct control over the state-updating behavior of a specific object. If not `None', this callable will have priority over the object’s *note __setstate__(): 19c. method. (Contributed by Pierre Glaser and Olivier Grisel in bpo-35900(17).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32489 (2) https://bugs.python.org/issue33073 (3) https://bugs.python.org/issue37819 (4) https://bugs.python.org/issue20092 (5) https://bugs.python.org/issue30688 (6) https://bugs.python.org/issue33462 (7) https://bugs.python.org/issue34641 (8) https://bugs.python.org/issue32117 (9) https://bugs.python.org/issue15248 (10) https://bugs.python.org/issue32417 (11) https://bugs.python.org/issue1054041 (12) https://bugs.python.org/issue37032 (13) https://en.wikipedia.org/wiki/Modular_multiplicative_inverse (14) https://en.wikipedia.org/wiki/Diophantine_equation (15) https://bugs.python.org/issue36027 (16) https://bugs.python.org/issue35224 (17) https://bugs.python.org/issue35900  File: python.info, Node: New Modules, Next: Improved Modules, Prev: Other Language Changes, Up: What’s New In Python 3 8 1.1.4 New Modules ----------------- * The new ‘importlib.metadata’ module provides (provisional) support for reading metadata from third-party packages. For example, it can extract an installed package’s version number, list of entry points, and more: >>> # Note following example requires that the popular "requests" >>> # package has been installed. >>> >>> from importlib.metadata import version, requires, files >>> version('requests') '2.22.0' >>> list(requires('requests')) ['chardet (<3.1.0,>=3.0.2)'] >>> list(files('requests'))[:5] [PackagePath('requests-2.22.0.dist-info/INSTALLER'), PackagePath('requests-2.22.0.dist-info/LICENSE'), PackagePath('requests-2.22.0.dist-info/METADATA'), PackagePath('requests-2.22.0.dist-info/RECORD'), PackagePath('requests-2.22.0.dist-info/WHEEL')] (Contributed by Barry Warsaw and Jason R. Coombs in bpo-34632(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34632  File: python.info, Node: Improved Modules, Next: Optimizations, Prev: New Modules, Up: What’s New In Python 3 8 1.1.5 Improved Modules ---------------------- * Menu: * ast:: * asyncio:: * builtins:: * collections:: * cProfile:: * csv:: * curses:: * ctypes:: * datetime:: * functools:: * gc:: * gettext:: * gzip:: * IDLE and idlelib:: * inspect:: * io:: * itertools:: * json.tool: json tool. * logging:: * math:: * mmap:: * multiprocessing:: * os:: * os.path: os path. * pathlib:: * pickle:: * plistlib:: * pprint:: * py_compile:: * shlex:: * shutil:: * socket:: * ssl:: * statistics:: * sys:: * tarfile:: * threading:: * tokenize:: * tkinter:: * time:: * typing:: * unicodedata:: * unittest:: * venv:: * weakref:: * xml:: * xmlrpc::  File: python.info, Node: ast, Next: asyncio, Up: Improved Modules 1.1.5.1 ast ........... AST nodes now have ‘end_lineno’ and ‘end_col_offset’ attributes, which give the precise location of the end of the node. (This only applies to nodes that have ‘lineno’ and ‘col_offset’ attributes.) New function *note ast.get_source_segment(): 1a0. returns the source code for a specific AST node. (Contributed by Ivan Levkivskyi in bpo-33416(1).) The *note ast.parse(): 1a1. function has some new flags: * ‘type_comments=True’ causes it to return the text of PEP 484(2) and PEP 526(3) type comments associated with certain AST nodes; * ‘mode='func_type'’ can be used to parse PEP 484(4) “signature type comments” (returned for function definition AST nodes); * ‘feature_version=(3, N)’ allows specifying an earlier Python 3 version. For example, ‘feature_version=(3, 4)’ will treat *note async: 1a2. and *note await: 1a3. as non-reserved words. (Contributed by Guido van Rossum in bpo-35766(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33416 (2) https://www.python.org/dev/peps/pep-0484 (3) https://www.python.org/dev/peps/pep-0526 (4) https://www.python.org/dev/peps/pep-0484 (5) https://bugs.python.org/issue35766  File: python.info, Node: asyncio, Next: builtins, Prev: ast, Up: Improved Modules 1.1.5.2 asyncio ............... *note asyncio.run(): 1a5. has graduated from the provisional to stable API. This function can be used to execute a *note coroutine: 1a6. and return the result while automatically managing the event loop. For example: import asyncio async def main(): await asyncio.sleep(0) return 42 asyncio.run(main()) This is `roughly' equivalent to: import asyncio async def main(): await asyncio.sleep(0) return 42 loop = asyncio.new_event_loop() asyncio.set_event_loop(loop) try: loop.run_until_complete(main()) finally: asyncio.set_event_loop(None) loop.close() The actual implementation is significantly more complex. Thus, *note asyncio.run(): 1a5. should be the preferred way of running asyncio programs. (Contributed by Yury Selivanov in bpo-32314(1).) Running ‘python -m asyncio’ launches a natively async REPL. This allows rapid experimentation with code that has a top-level *note await: 1a3. There is no longer a need to directly call ‘asyncio.run()’ which would spawn a new event loop on every invocation: $ python -m asyncio asyncio REPL 3.8.0 Use "await" directly instead of "asyncio.run()". Type "help", "copyright", "credits" or "license" for more information. >>> import asyncio >>> await asyncio.sleep(10, result='hello') hello (Contributed by Yury Selivanov in bpo-37028(2).) The exception *note asyncio.CancelledError: 1a7. now inherits from *note BaseException: 1a8. rather than *note Exception: 1a9. and no longer inherits from *note concurrent.futures.CancelledError: 1aa. (Contributed by Yury Selivanov in bpo-32528(3).) On Windows, the default event loop is now *note ProactorEventLoop: 1ab. (Contributed by Victor Stinner in bpo-34687(4).) *note ProactorEventLoop: 1ab. now also supports UDP. (Contributed by Adam Meily and Andrew Svetlov in bpo-29883(5).) *note ProactorEventLoop: 1ab. can now be interrupted by *note KeyboardInterrupt: 197. (“CTRL+C”). (Contributed by Vladimir Matveev in bpo-23057(6).) Added *note asyncio.Task.get_coro(): 1ac. for getting the wrapped coroutine within an *note asyncio.Task: 1ad. (Contributed by Alex Grönholm in bpo-36999(7).) Asyncio tasks can now be named, either by passing the ‘name’ keyword argument to *note asyncio.create_task(): 1ae. or the *note create_task(): 1af. event loop method, or by calling the *note set_name(): 1b0. method on the task object. The task name is visible in the ‘repr()’ output of *note asyncio.Task: 1ad. and can also be retrieved using the *note get_name(): 1b1. method. (Contributed by Alex Grönholm in bpo-34270(8).) Added support for Happy Eyeballs(9) to *note asyncio.loop.create_connection(): 1b2. To specify the behavior, two new parameters have been added: `happy_eyeballs_delay' and `interleave'. The Happy Eyeballs algorithm improves responsiveness in applications that support IPv4 and IPv6 by attempting to simultaneously connect using both. (Contributed by twisteroid ambassador in bpo-33530(10).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32314 (2) https://bugs.python.org/issue37028 (3) https://bugs.python.org/issue32528 (4) https://bugs.python.org/issue34687 (5) https://bugs.python.org/issue29883 (6) https://bugs.python.org/issue23057 (7) https://bugs.python.org/issue36999 (8) https://bugs.python.org/issue34270 (9) https://en.wikipedia.org/wiki/Happy_Eyeballs (10) https://bugs.python.org/issue33530  File: python.info, Node: builtins, Next: collections, Prev: asyncio, Up: Improved Modules 1.1.5.3 builtins ................ The *note compile(): 1b4. built-in has been improved to accept the ‘ast.PyCF_ALLOW_TOP_LEVEL_AWAIT’ flag. With this new flag passed, *note compile(): 1b4. will allow top-level ‘await’, ‘async for’ and ‘async with’ constructs that are usually considered invalid syntax. Asynchronous code object marked with the ‘CO_COROUTINE’ flag may then be returned. (Contributed by Matthias Bussonnier in bpo-34616(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34616  File: python.info, Node: collections, Next: cProfile, Prev: builtins, Up: Improved Modules 1.1.5.4 collections ................... The *note _asdict(): 1b6. method for *note collections.namedtuple(): 1b7. now returns a *note dict: 1b8. instead of a *note collections.OrderedDict: 1b9. This works because regular dicts have guaranteed ordering since Python 3.7. If the extra features of ‘OrderedDict’ are required, the suggested remediation is to cast the result to the desired type: ‘OrderedDict(nt._asdict())’. (Contributed by Raymond Hettinger in bpo-35864(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35864  File: python.info, Node: cProfile, Next: csv, Prev: collections, Up: Improved Modules 1.1.5.5 cProfile ................ The *note cProfile.Profile: 1bb. class can now be used as a context manager. Profile a block of code by running: import cProfile with cProfile.Profile() as profiler: # code to be profiled ... (Contributed by Scott Sanderson in bpo-29235(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29235  File: python.info, Node: csv, Next: curses, Prev: cProfile, Up: Improved Modules 1.1.5.6 csv ........... The *note csv.DictReader: 1bd. now returns instances of *note dict: 1b8. instead of a *note collections.OrderedDict: 1b9. The tool is now faster and uses less memory while still preserving the field order. (Contributed by Michael Selik in bpo-34003(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34003  File: python.info, Node: curses, Next: ctypes, Prev: csv, Up: Improved Modules 1.1.5.7 curses .............. Added a new variable holding structured version information for the underlying ncurses library: *note ncurses_version: 1bf. (Contributed by Serhiy Storchaka in bpo-31680(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31680  File: python.info, Node: ctypes, Next: datetime, Prev: curses, Up: Improved Modules 1.1.5.8 ctypes .............. On Windows, *note CDLL: 1c1. and subclasses now accept a `winmode' parameter to specify flags for the underlying ‘LoadLibraryEx’ call. The default flags are set to only load DLL dependencies from trusted locations, including the path where the DLL is stored (if a full or partial path is used to load the initial DLL) and paths added by *note add_dll_directory(): 1c2. (Contributed by Steve Dower in bpo-36085(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36085  File: python.info, Node: datetime, Next: functools, Prev: ctypes, Up: Improved Modules 1.1.5.9 datetime ................ Added new alternate constructors *note datetime.date.fromisocalendar(): 1c4. and *note datetime.datetime.fromisocalendar(): 1c5, which construct ‘date’ and *note datetime: 31. objects respectively from ISO year, week number, and weekday; these are the inverse of each class’s ‘isocalendar’ method. (Contributed by Paul Ganssle in bpo-36004(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36004  File: python.info, Node: functools, Next: gc, Prev: datetime, Up: Improved Modules 1.1.5.10 functools .................. *note functools.lru_cache(): 1c7. can now be used as a straight decorator rather than as a function returning a decorator. So both of these are now supported: @lru_cache def f(x): ... @lru_cache(maxsize=256) def f(x): ... (Contributed by Raymond Hettinger in bpo-36772(1).) Added a new *note functools.cached_property(): 1c8. decorator, for computed properties cached for the life of the instance. import functools import statistics class Dataset: def __init__(self, sequence_of_numbers): self.data = sequence_of_numbers @functools.cached_property def variance(self): return statistics.variance(self.data) (Contributed by Carl Meyer in bpo-21145(2)) Added a new *note functools.singledispatchmethod(): 1c9. decorator that converts methods into *note generic functions: 1ca. using *note single dispatch: 1cb.: from functools import singledispatchmethod from contextlib import suppress class TaskManager: def __init__(self, tasks): self.tasks = list(tasks) @singledispatchmethod def discard(self, value): with suppress(ValueError): self.tasks.remove(value) @discard.register(list) def _(self, tasks): targets = set(tasks) self.tasks = [x for x in self.tasks if x not in targets] (Contributed by Ethan Smith in bpo-32380(3)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36772 (2) https://bugs.python.org/issue21145 (3) https://bugs.python.org/issue32380  File: python.info, Node: gc, Next: gettext, Prev: functools, Up: Improved Modules 1.1.5.11 gc ........... *note get_objects(): 1cd. can now receive an optional `generation' parameter indicating a generation to get objects from. (Contributed by Pablo Galindo in bpo-36016(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36016  File: python.info, Node: gettext, Next: gzip, Prev: gc, Up: Improved Modules 1.1.5.12 gettext ................ Added *note pgettext(): 1cf. and its variants. (Contributed by Franz Glasner, Éric Araujo, and Cheryl Sabella in bpo-2504(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2504  File: python.info, Node: gzip, Next: IDLE and idlelib, Prev: gettext, Up: Improved Modules 1.1.5.13 gzip ............. Added the `mtime' parameter to *note gzip.compress(): 1d1. for reproducible output. (Contributed by Guo Ci Teo in bpo-34898(1).) A *note BadGzipFile: 1d2. exception is now raised instead of *note OSError: 1d3. for certain types of invalid or corrupt gzip files. (Contributed by Filip Gruszczyński, Michele Orrù, and Zackery Spytz in bpo-6584(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34898 (2) https://bugs.python.org/issue6584  File: python.info, Node: IDLE and idlelib, Next: inspect, Prev: gzip, Up: Improved Modules 1.1.5.14 IDLE and idlelib ......................... Output over N lines (50 by default) is squeezed down to a button. N can be changed in the PyShell section of the General page of the Settings dialog. Fewer, but possibly extra long, lines can be squeezed by right clicking on the output. Squeezed output can be expanded in place by double-clicking the button or into the clipboard or a separate window by right-clicking the button. (Contributed by Tal Einat in bpo-1529353(1).) Add “Run Customized” to the Run menu to run a module with customized settings. Any command line arguments entered are added to sys.argv. They also re-appear in the box for the next customized run. One can also suppress the normal Shell main module restart. (Contributed by Cheryl Sabella, Terry Jan Reedy, and others in bpo-5680(2) and bpo-37627(3).) Added optional line numbers for IDLE editor windows. Windows open without line numbers unless set otherwise in the General tab of the configuration dialog. Line numbers for an existing window are shown and hidden in the Options menu. (Contributed by Tal Einat and Saimadhav Heblikar in bpo-17535(4).) OS native encoding is now used for converting between Python strings and Tcl objects. This allows IDLE to work with emoji and other non-BMP characters. These characters can be displayed or copied and pasted to or from the clipboard. Converting strings from Tcl to Python and back now never fails. (Many people worked on this for eight years but the problem was finally solved by Serhiy Storchaka in bpo-13153(5).) New in 3.8.1: Add option to toggle cursor blink off. (Contributed by Zackery Spytz in bpo-4603(6).) Escape key now closes IDLE completion windows. (Contributed by Johnny Najera in bpo-38944(7).) The changes above have been backported to 3.7 maintenance releases. Add keywords to module name completion list. (Contributed by Terry J. Reedy in bpo-37765(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1529353 (2) https://bugs.python.org/issue5680 (3) https://bugs.python.org/issue37627 (4) https://bugs.python.org/issue17535 (5) https://bugs.python.org/issue13153 (6) https://bugs.python.org/issue4603 (7) https://bugs.python.org/issue38944 (8) https://bugs.python.org/issue37765  File: python.info, Node: inspect, Next: io, Prev: IDLE and idlelib, Up: Improved Modules 1.1.5.15 inspect ................ The *note inspect.getdoc(): 1d6. function can now find docstrings for ‘__slots__’ if that attribute is a *note dict: 1b8. where the values are docstrings. This provides documentation options similar to what we already have for *note property(): 1d7, *note classmethod(): 1d8, and *note staticmethod(): 1d9.: class AudioClip: __slots__ = {'bit_rate': 'expressed in kilohertz to one decimal place', 'duration': 'in seconds, rounded up to an integer'} def __init__(self, bit_rate, duration): self.bit_rate = round(bit_rate / 1000.0, 1) self.duration = ceil(duration) (Contributed by Raymond Hettinger in bpo-36326(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36326  File: python.info, Node: io, Next: itertools, Prev: inspect, Up: Improved Modules 1.1.5.16 io ........... In development mode (*note -X: 155. ‘env’) and in debug build, the *note io.IOBase: 1db. finalizer now logs the exception if the ‘close()’ method fails. The exception is ignored silently by default in release build. (Contributed by Victor Stinner in bpo-18748(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18748  File: python.info, Node: itertools, Next: json tool, Prev: io, Up: Improved Modules 1.1.5.17 itertools .................. The *note itertools.accumulate(): 1dd. function added an option `initial' keyword argument to specify an initial value: >>> from itertools import accumulate >>> list(accumulate([10, 5, 30, 15], initial=1000)) [1000, 1010, 1015, 1045, 1060] (Contributed by Lisa Roach in bpo-34659(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34659  File: python.info, Node: json tool, Next: logging, Prev: itertools, Up: Improved Modules 1.1.5.18 json.tool .................. Add option ‘--json-lines’ to parse every input line as a separate JSON object. (Contributed by Weipeng Hong in bpo-31553(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31553  File: python.info, Node: logging, Next: math, Prev: json tool, Up: Improved Modules 1.1.5.19 logging ................ Added a `force' keyword argument to *note logging.basicConfig(): 1e0. When set to true, any existing handlers attached to the root logger are removed and closed before carrying out the configuration specified by the other arguments. This solves a long-standing problem. Once a logger or `basicConfig()' had been called, subsequent calls to `basicConfig()' were silently ignored. This made it difficult to update, experiment with, or teach the various logging configuration options using the interactive prompt or a Jupyter notebook. (Suggested by Raymond Hettinger, implemented by Dong-hee Na, and reviewed by Vinay Sajip in bpo-33897(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33897  File: python.info, Node: math, Next: mmap, Prev: logging, Up: Improved Modules 1.1.5.20 math ............. Added new function *note math.dist(): 1e2. for computing Euclidean distance between two points. (Contributed by Raymond Hettinger in bpo-33089(1).) Expanded the *note math.hypot(): 1e3. function to handle multiple dimensions. Formerly, it only supported the 2-D case. (Contributed by Raymond Hettinger in bpo-33089(2).) Added new function, *note math.prod(): 1e4, as analogous function to *note sum(): 1e5. that returns the product of a ‘start’ value (default: 1) times an iterable of numbers: >>> prior = 0.8 >>> likelihoods = [0.625, 0.84, 0.30] >>> math.prod(likelihoods, start=prior) 0.126 (Contributed by Pablo Galindo in bpo-35606(3).) Added two new combinatoric functions *note math.perm(): 1e6. and *note math.comb(): 1e7.: >>> math.perm(10, 3) # Permutations of 10 things taken 3 at a time 720 >>> math.comb(10, 3) # Combinations of 10 things taken 3 at a time 120 (Contributed by Yash Aggarwal, Keller Fuchs, Serhiy Storchaka, and Raymond Hettinger in bpo-37128(4), bpo-37178(5), and bpo-35431(6).) Added a new function *note math.isqrt(): 1e8. for computing accurate integer square roots without conversion to floating point. The new function supports arbitrarily large integers. It is faster than ‘floor(sqrt(n))’ but slower than *note math.sqrt(): 1e9.: >>> r = 650320427 >>> s = r ** 2 >>> isqrt(s - 1) # correct 650320426 >>> floor(sqrt(s - 1)) # incorrect 650320427 (Contributed by Mark Dickinson in bpo-36887(7).) The function *note math.factorial(): 1ea. no longer accepts arguments that are not int-like. (Contributed by Pablo Galindo in bpo-33083(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33089 (2) https://bugs.python.org/issue33089 (3) https://bugs.python.org/issue35606 (4) https://bugs.python.org/issue37128 (5) https://bugs.python.org/issue37178 (6) https://bugs.python.org/issue35431 (7) https://bugs.python.org/issue36887 (8) https://bugs.python.org/issue33083  File: python.info, Node: mmap, Next: multiprocessing, Prev: math, Up: Improved Modules 1.1.5.21 mmap ............. The *note mmap.mmap: 1ec. class now has an *note madvise(): 1ed. method to access the ‘madvise()’ system call. (Contributed by Zackery Spytz in bpo-32941(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32941  File: python.info, Node: multiprocessing, Next: os, Prev: mmap, Up: Improved Modules 1.1.5.22 multiprocessing ........................ Added new *note multiprocessing.shared_memory: bc. module. (Contributed by Davin Potts in bpo-35813(1).) On macOS, the `spawn' start method is now used by default. (Contributed by Victor Stinner in bpo-33725(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35813 (2) https://bugs.python.org/issue33725  File: python.info, Node: os, Next: os path, Prev: multiprocessing, Up: Improved Modules 1.1.5.23 os ........... Added new function *note add_dll_directory(): 1c2. on Windows for providing additional search paths for native dependencies when importing extension modules or loading DLLs using *note ctypes: 2b. (Contributed by Steve Dower in bpo-36085(1).) A new *note os.memfd_create(): 1f0. function was added to wrap the ‘memfd_create()’ syscall. (Contributed by Zackery Spytz and Christian Heimes in bpo-26836(2).) On Windows, much of the manual logic for handling reparse points (including symlinks and directory junctions) has been delegated to the operating system. Specifically, *note os.stat(): 1f1. will now traverse anything supported by the operating system, while *note os.lstat(): 1f2. will only open reparse points that identify as “name surrogates” while others are opened as for *note os.stat(): 1f1. In all cases, ‘stat_result.st_mode’ will only have ‘S_IFLNK’ set for symbolic links and not other kinds of reparse points. To identify other kinds of reparse point, check the new ‘stat_result.st_reparse_tag’ attribute. On Windows, *note os.readlink(): 1f3. is now able to read directory junctions. Note that *note islink(): 1f4. will return ‘False’ for directory junctions, and so code that checks ‘islink’ first will continue to treat junctions as directories, while code that handles errors from *note os.readlink(): 1f3. may now treat junctions as links. (Contributed by Steve Dower in bpo-37834(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36085 (2) https://bugs.python.org/issue26836 (3) https://bugs.python.org/issue37834  File: python.info, Node: os path, Next: pathlib, Prev: os, Up: Improved Modules 1.1.5.24 os.path ................ *note os.path: c5. functions that return a boolean result like *note exists(): 1f6, *note lexists(): 1f7, *note isdir(): 1f8, *note isfile(): 1f9, *note islink(): 1f4, and *note ismount(): 1fa. now return ‘False’ instead of raising *note ValueError: 1fb. or its subclasses *note UnicodeEncodeError: 1fc. and *note UnicodeDecodeError: 1fd. for paths that contain characters or bytes unrepresentable at the OS level. (Contributed by Serhiy Storchaka in bpo-33721(1).) *note expanduser(): 1fe. on Windows now prefers the ‘USERPROFILE’ environment variable and does not use ‘HOME’, which is not normally set for regular user accounts. (Contributed by Anthony Sottile in bpo-36264(2).) *note isdir(): 1f8. on Windows no longer returns ‘True’ for a link to a non-existent directory. *note realpath(): 1ff. on Windows now resolves reparse points, including symlinks and directory junctions. (Contributed by Steve Dower in bpo-37834(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33721 (2) https://bugs.python.org/issue36264 (3) https://bugs.python.org/issue37834  File: python.info, Node: pathlib, Next: pickle, Prev: os path, Up: Improved Modules 1.1.5.25 pathlib ................ *note pathlib.Path: 201. methods that return a boolean result like *note exists(): 202, *note is_dir(): 203, *note is_file(): 204, *note is_mount(): 205, *note is_symlink(): 206, *note is_block_device(): 207, *note is_char_device(): 208, *note is_fifo(): 209, *note is_socket(): 20a. now return ‘False’ instead of raising *note ValueError: 1fb. or its subclass *note UnicodeEncodeError: 1fc. for paths that contain characters unrepresentable at the OS level. (Contributed by Serhiy Storchaka in bpo-33721(1).) Added *note pathlib.Path.link_to(): 20b. which creates a hard link pointing to a path. (Contributed by Joannah Nanjekye in bpo-26978(2)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33721 (2) https://bugs.python.org/issue26978  File: python.info, Node: pickle, Next: plistlib, Prev: pathlib, Up: Improved Modules 1.1.5.26 pickle ............... *note pickle: ca. extensions subclassing the C-optimized *note Pickler: 20d. can now override the pickling logic of functions and classes by defining the special *note reducer_override(): 20e. method. (Contributed by Pierre Glaser and Olivier Grisel in bpo-35900(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35900  File: python.info, Node: plistlib, Next: pprint, Prev: pickle, Up: Improved Modules 1.1.5.27 plistlib ................. Added new *note plistlib.UID: 210. and enabled support for reading and writing NSKeyedArchiver-encoded binary plists. (Contributed by Jon Janzen in bpo-26707(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26707  File: python.info, Node: pprint, Next: py_compile, Prev: plistlib, Up: Improved Modules 1.1.5.28 pprint ............... The *note pprint: d2. module added a `sort_dicts' parameter to several functions. By default, those functions continue to sort dictionaries before rendering or printing. However, if `sort_dicts' is set to false, the dictionaries retain the order that keys were inserted. This can be useful for comparison to JSON inputs during debugging. In addition, there is a convenience new function, *note pprint.pp(): 212. that is like *note pprint.pprint(): 213. but with `sort_dicts' defaulting to ‘False’: >>> from pprint import pprint, pp >>> d = dict(source='input.txt', operation='filter', destination='output.txt') >>> pp(d, width=40) # Original order {'source': 'input.txt', 'operation': 'filter', 'destination': 'output.txt'} >>> pprint(d, width=40) # Keys sorted alphabetically {'destination': 'output.txt', 'operation': 'filter', 'source': 'input.txt'} (Contributed by Rémi Lapeyre in bpo-30670(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30670  File: python.info, Node: py_compile, Next: shlex, Prev: pprint, Up: Improved Modules 1.1.5.29 py_compile ................... *note py_compile.compile(): 215. now supports silent mode. (Contributed by Joannah Nanjekye in bpo-22640(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22640  File: python.info, Node: shlex, Next: shutil, Prev: py_compile, Up: Improved Modules 1.1.5.30 shlex .............. The new *note shlex.join(): 217. function acts as the inverse of *note shlex.split(): 218. (Contributed by Bo Bayles in bpo-32102(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32102  File: python.info, Node: shutil, Next: socket, Prev: shlex, Up: Improved Modules 1.1.5.31 shutil ............... *note shutil.copytree(): 21a. now accepts a new ‘dirs_exist_ok’ keyword argument. (Contributed by Josh Bronson in bpo-20849(1).) *note shutil.make_archive(): 21b. now defaults to the modern pax (POSIX.1-2001) format for new archives to improve portability and standards conformance, inherited from the corresponding change to the *note tarfile: 101. module. (Contributed by C.A.M. Gerlach in bpo-30661(2).) *note shutil.rmtree(): 21c. on Windows now removes directory junctions without recursively removing their contents first. (Contributed by Steve Dower in bpo-37834(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20849 (2) https://bugs.python.org/issue30661 (3) https://bugs.python.org/issue37834  File: python.info, Node: socket, Next: ssl, Prev: shutil, Up: Improved Modules 1.1.5.32 socket ............... Added *note create_server(): 21e. and *note has_dualstack_ipv6(): 21f. convenience functions to automate the necessary tasks usually involved when creating a server socket, including accepting both IPv4 and IPv6 connections on the same socket. (Contributed by Giampaolo Rodolà in bpo-17561(1).) The *note socket.if_nameindex(): 220, *note socket.if_nametoindex(): 221, and *note socket.if_indextoname(): 222. functions have been implemented on Windows. (Contributed by Zackery Spytz in bpo-37007(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17561 (2) https://bugs.python.org/issue37007  File: python.info, Node: ssl, Next: statistics, Prev: socket, Up: Improved Modules 1.1.5.33 ssl ............ Added *note post_handshake_auth: 224. to enable and *note verify_client_post_handshake(): 225. to initiate TLS 1.3 post-handshake authentication. (Contributed by Christian Heimes in bpo-34670(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34670  File: python.info, Node: statistics, Next: sys, Prev: ssl, Up: Improved Modules 1.1.5.34 statistics ................... Added *note statistics.fmean(): 227. as a faster, floating point variant of *note statistics.mean(): 199. (Contributed by Raymond Hettinger and Steven D’Aprano in bpo-35904(1).) Added *note statistics.geometric_mean(): 228. (Contributed by Raymond Hettinger in bpo-27181(2).) Added *note statistics.multimode(): 229. that returns a list of the most common values. (Contributed by Raymond Hettinger in bpo-35892(3).) Added *note statistics.quantiles(): 22a. that divides data or a distribution in to equiprobable intervals (e.g. quartiles, deciles, or percentiles). (Contributed by Raymond Hettinger in bpo-36546(4).) Added *note statistics.NormalDist: 22b, a tool for creating and manipulating normal distributions of a random variable. (Contributed by Raymond Hettinger in bpo-36018(5).) >>> temperature_feb = NormalDist.from_samples([4, 12, -3, 2, 7, 14]) >>> temperature_feb.mean 6.0 >>> temperature_feb.stdev 6.356099432828281 >>> temperature_feb.cdf(3) # Chance of being under 3 degrees 0.3184678262814532 >>> # Relative chance of being 7 degrees versus 10 degrees >>> temperature_feb.pdf(7) / temperature_feb.pdf(10) 1.2039930378537762 >>> el_niño = NormalDist(4, 2.5) >>> temperature_feb += el_niño # Add in a climate effect >>> temperature_feb NormalDist(mu=10.0, sigma=6.830080526611674) >>> temperature_feb * (9/5) + 32 # Convert to Fahrenheit NormalDist(mu=50.0, sigma=12.294144947901014) >>> temperature_feb.samples(3) # Generate random samples [7.672102882379219, 12.000027119750287, 4.647488369766392] ---------- Footnotes ---------- (1) https://bugs.python.org/issue35904 (2) https://bugs.python.org/issue27181 (3) https://bugs.python.org/issue35892 (4) https://bugs.python.org/issue36546 (5) https://bugs.python.org/issue36018  File: python.info, Node: sys, Next: tarfile, Prev: statistics, Up: Improved Modules 1.1.5.35 sys ............ Add new *note sys.unraisablehook(): 22d. function which can be overridden to control how “unraisable exceptions” are handled. It is called when an exception has occurred but there is no way for Python to handle it. For example, when a destructor raises an exception or during garbage collection (*note gc.collect(): 22e.). (Contributed by Victor Stinner in bpo-36829(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36829  File: python.info, Node: tarfile, Next: threading, Prev: sys, Up: Improved Modules 1.1.5.36 tarfile ................ The *note tarfile: 101. module now defaults to the modern pax (POSIX.1-2001) format for new archives, instead of the previous GNU-specific one. This improves cross-platform portability with a consistent encoding (UTF-8) in a standardized and extensible format, and offers several other benefits. (Contributed by C.A.M. Gerlach in bpo-36268(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36268  File: python.info, Node: threading, Next: tokenize, Prev: tarfile, Up: Improved Modules 1.1.5.37 threading .................. Add a new *note threading.excepthook(): 231. function which handles uncaught *note threading.Thread.run(): 232. exception. It can be overridden to control how uncaught *note threading.Thread.run(): 232. exceptions are handled. (Contributed by Victor Stinner in bpo-1230540(1).) Add a new *note threading.get_native_id(): 233. function and a *note native_id: 234. attribute to the *note threading.Thread: 235. class. These return the native integral Thread ID of the current thread assigned by the kernel. This feature is only available on certain platforms, see *note get_native_id: 233. for more information. (Contributed by Jake Tesler in bpo-36084(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1230540 (2) https://bugs.python.org/issue36084  File: python.info, Node: tokenize, Next: tkinter, Prev: threading, Up: Improved Modules 1.1.5.38 tokenize ................. The *note tokenize: 111. module now implicitly emits a ‘NEWLINE’ token when provided with input that does not have a trailing new line. This behavior now matches what the C tokenizer does internally. (Contributed by Ammar Askar in bpo-33899(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33899  File: python.info, Node: tkinter, Next: time, Prev: tokenize, Up: Improved Modules 1.1.5.39 tkinter ................ Added methods ‘selection_from()’, ‘selection_present()’, ‘selection_range()’ and ‘selection_to()’ in the ‘tkinter.Spinbox’ class. (Contributed by Juliette Monsel in bpo-34829(1).) Added method ‘moveto()’ in the ‘tkinter.Canvas’ class. (Contributed by Juliette Monsel in bpo-23831(2).) The ‘tkinter.PhotoImage’ class now has ‘transparency_get()’ and ‘transparency_set()’ methods. (Contributed by Zackery Spytz in bpo-25451(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34829 (2) https://bugs.python.org/issue23831 (3) https://bugs.python.org/issue25451  File: python.info, Node: time, Next: typing, Prev: tkinter, Up: Improved Modules 1.1.5.40 time ............. Added new clock *note CLOCK_UPTIME_RAW: 239. for macOS 10.12. (Contributed by Joannah Nanjekye in bpo-35702(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35702  File: python.info, Node: typing, Next: unicodedata, Prev: time, Up: Improved Modules 1.1.5.41 typing ............... The *note typing: 119. module incorporates several new features: * A dictionary type with per-key types. See PEP 589(1) and *note typing.TypedDict: 23b. TypedDict uses only string keys. By default, every key is required to be present. Specify “total=False” to allow keys to be optional: class Location(TypedDict, total=False): lat_long: tuple grid_square: str xy_coordinate: tuple * Literal types. See PEP 586(2) and *note typing.Literal: 23c. Literal types indicate that a parameter or return value is constrained to one or more specific literal values: def get_status(port: int) -> Literal['connected', 'disconnected']: ... * “Final” variables, functions, methods and classes. See PEP 591(3), *note typing.Final: 23d. and *note typing.final(): 23e. The final qualifier instructs a static type checker to restrict subclassing, overriding, or reassignment: pi: Final[float] = 3.1415926536 * Protocol definitions. See PEP 544(4), *note typing.Protocol: 23f. and *note typing.runtime_checkable(): 240. Simple ABCs like *note typing.SupportsInt: 241. are now ‘Protocol’ subclasses. * New protocol class *note typing.SupportsIndex: 242. * New functions *note typing.get_origin(): 243. and *note typing.get_args(): 244. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0589 (2) https://www.python.org/dev/peps/pep-0586 (3) https://www.python.org/dev/peps/pep-0591 (4) https://www.python.org/dev/peps/pep-0544  File: python.info, Node: unicodedata, Next: unittest, Prev: typing, Up: Improved Modules 1.1.5.42 unicodedata .................... The *note unicodedata: 11a. module has been upgraded to use the Unicode 12.1.0(1) release. New function *note is_normalized(): 246. can be used to verify a string is in a specific normal form, often much faster than by actually normalizing the string. (Contributed by Max Belanger, David Euresti, and Greg Price in bpo-32285(2) and bpo-37966(3)). ---------- Footnotes ---------- (1) http://blog.unicode.org/2019/05/unicode-12-1-en.html (2) https://bugs.python.org/issue32285 (3) https://bugs.python.org/issue37966  File: python.info, Node: unittest, Next: venv, Prev: unicodedata, Up: Improved Modules 1.1.5.43 unittest ................. Added *note AsyncMock: 248. to support an asynchronous version of *note Mock: 249. Appropriate new assert functions for testing have been added as well. (Contributed by Lisa Roach in bpo-26467(1)). Added *note addModuleCleanup(): 24a. and *note addClassCleanup(): 24b. to unittest to support cleanups for ‘setUpModule()’ and *note setUpClass(): 24c. (Contributed by Lisa Roach in bpo-24412(2).) Several mock assert functions now also print a list of actual calls upon failure. (Contributed by Petter Strandmark in bpo-35047(3).) *note unittest: 11b. module gained support for coroutines to be used as test cases with *note unittest.IsolatedAsyncioTestCase: 24d. (Contributed by Andrew Svetlov in bpo-32972(4).) Example: import unittest class TestRequest(unittest.IsolatedAsyncioTestCase): async def asyncSetUp(self): self.connection = await AsyncConnection() async def test_get(self): response = await self.connection.get("https://example.com") self.assertEqual(response.status_code, 200) async def asyncTearDown(self): await self.connection.close() if __name__ == "__main__": unittest.main() ---------- Footnotes ---------- (1) https://bugs.python.org/issue26467 (2) https://bugs.python.org/issue24412 (3) https://bugs.python.org/issue35047 (4) https://bugs.python.org/issue32972  File: python.info, Node: venv, Next: weakref, Prev: unittest, Up: Improved Modules 1.1.5.44 venv ............. *note venv: 125. now includes an ‘Activate.ps1’ script on all platforms for activating virtual environments under PowerShell Core 6.1. (Contributed by Brett Cannon in bpo-32718(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32718  File: python.info, Node: weakref, Next: xml, Prev: venv, Up: Improved Modules 1.1.5.45 weakref ................ The proxy objects returned by *note weakref.proxy(): 250. now support the matrix multiplication operators ‘@’ and ‘@=’ in addition to the other numeric operators. (Contributed by Mark Dickinson in bpo-36669(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36669  File: python.info, Node: xml, Next: xmlrpc, Prev: weakref, Up: Improved Modules 1.1.5.46 xml ............ As mitigation against DTD and external entity retrieval, the *note xml.dom.minidom: 135. and *note xml.sax: 13b. modules no longer process external entities by default. (Contributed by Christian Heimes in bpo-17239(1).) The ‘.find*()’ methods in the *note xml.etree.ElementTree: 137. module support wildcard searches like ‘{*}tag’ which ignores the namespace and ‘{namespace}*’ which returns all tags in the given namespace. (Contributed by Stefan Behnel in bpo-28238(2).) The *note xml.etree.ElementTree: 137. module provides a new function ‘–xml.etree.ElementTree.canonicalize()’ that implements C14N 2.0. (Contributed by Stefan Behnel in bpo-13611(3).) The target object of *note xml.etree.ElementTree.XMLParser: 252. can receive namespace declaration events through the new callback methods ‘start_ns()’ and ‘end_ns()’. Additionally, the *note xml.etree.ElementTree.TreeBuilder: 253. target can be configured to process events about comments and processing instructions to include them in the generated tree. (Contributed by Stefan Behnel in bpo-36676(4) and bpo-36673(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17239 (2) https://bugs.python.org/issue28238 (3) https://bugs.python.org/issue13611 (4) https://bugs.python.org/issue36676 (5) https://bugs.python.org/issue36673  File: python.info, Node: xmlrpc, Prev: xml, Up: Improved Modules 1.1.5.47 xmlrpc ............... *note xmlrpc.client.ServerProxy: 255. now supports an optional `headers' keyword argument for a sequence of HTTP headers to be sent with each request. Among other things, this makes it possible to upgrade from default basic authentication to faster session authentication. (Contributed by Cédric Krier in bpo-35153(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35153  File: python.info, Node: Optimizations, Next: Build and C API Changes, Prev: Improved Modules, Up: What’s New In Python 3 8 1.1.6 Optimizations ------------------- * The *note subprocess: f9. module can now use the *note os.posix_spawn(): 257. function in some cases for better performance. Currently, it is only used on macOS and Linux (using glibc 2.24 or newer) if all these conditions are met: * `close_fds' is false; * `preexec_fn', `pass_fds', `cwd' and `start_new_session' parameters are not set; * the `executable' path contains a directory. (Contributed by Joannah Nanjekye and Victor Stinner in bpo-35537(1).) * *note shutil.copyfile(): 258, *note shutil.copy(): 259, *note shutil.copy2(): 25a, *note shutil.copytree(): 21a. and *note shutil.move(): 25b. use platform-specific “fast-copy” syscalls on Linux and macOS in order to copy the file more efficiently. “fast-copy” means that the copying operation occurs within the kernel, avoiding the use of userspace buffers in Python as in “‘outfd.write(infd.read())’”. On Windows *note shutil.copyfile(): 258. uses a bigger default buffer size (1 MiB instead of 16 KiB) and a *note memoryview(): 25c.-based variant of *note shutil.copyfileobj(): 25d. is used. The speedup for copying a 512 MiB file within the same partition is about +26% on Linux, +50% on macOS and +40% on Windows. Also, much less CPU cycles are consumed. See *note Platform-dependent efficient copy operations: 25e. section. (Contributed by Giampaolo Rodolà in bpo-33671(2).) * *note shutil.copytree(): 21a. uses *note os.scandir(): 25f. function and all copy functions depending from it use cached *note os.stat(): 1f1. values. The speedup for copying a directory with 8000 files is around +9% on Linux, +20% on Windows and +30% on a Windows SMB share. Also the number of *note os.stat(): 1f1. syscalls is reduced by 38% making *note shutil.copytree(): 21a. especially faster on network filesystems. (Contributed by Giampaolo Rodolà in bpo-33695(3).) * The default protocol in the *note pickle: ca. module is now Protocol 4, first introduced in Python 3.4. It offers better performance and smaller size compared to Protocol 3 available since Python 3.0. * Removed one ‘Py_ssize_t’ member from ‘PyGC_Head’. All GC tracked objects (e.g. tuple, list, dict) size is reduced 4 or 8 bytes. (Contributed by Inada Naoki in bpo-33597(4).) * *note uuid.UUID: 260. now uses ‘__slots__’ to reduce its memory footprint. (Contributed by Wouter Bolsterlee and Tal Einat in bpo-30977(5)) * Improved performance of *note operator.itemgetter(): 261. by 33%. Optimized argument handling and added a fast path for the common case of a single non-negative integer index into a tuple (which is the typical use case in the standard library). (Contributed by Raymond Hettinger in bpo-35664(6).) * Sped-up field lookups in *note collections.namedtuple(): 1b7. They are now more than two times faster, making them the fastest form of instance variable lookup in Python. (Contributed by Raymond Hettinger, Pablo Galindo, and Joe Jevnik, Serhiy Storchaka in bpo-32492(7).) * The *note list: 262. constructor does not overallocate the internal item buffer if the input iterable has a known length (the input implements ‘__len__’). This makes the created list 12% smaller on average. (Contributed by Raymond Hettinger and Pablo Galindo in bpo-33234(8).) * Doubled the speed of class variable writes. When a non-dunder attribute was updated, there was an unnecessary call to update slots. (Contributed by Stefan Behnel, Pablo Galindo Salgado, Raymond Hettinger, Neil Schemenauer, and Serhiy Storchaka in bpo-36012(9).) * Reduced an overhead of converting arguments passed to many builtin functions and methods. This sped up calling some simple builtin functions and methods up to 20–50%. (Contributed by Serhiy Storchaka in bpo-23867(10), bpo-35582(11) and bpo-36127(12).) * ‘LOAD_GLOBAL’ instruction now uses new “per opcode cache” mechanism. It is about 40% faster now. (Contributed by Yury Selivanov and Inada Naoki in bpo-26219(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35537 (2) https://bugs.python.org/issue33671 (3) https://bugs.python.org/issue33695 (4) https://bugs.python.org/issue33597 (5) https://bugs.python.org/issue30977 (6) https://bugs.python.org/issue35664 (7) https://bugs.python.org/issue32492 (8) https://bugs.python.org/issue33234 (9) https://bugs.python.org/issue36012 (10) https://bugs.python.org/issue23867 (11) https://bugs.python.org/issue35582 (12) https://bugs.python.org/issue36127 (13) https://bugs.python.org/issue26219  File: python.info, Node: Build and C API Changes, Next: Deprecated, Prev: Optimizations, Up: What’s New In Python 3 8 1.1.7 Build and C API Changes ----------------------------- * Default *note sys.abiflags: 264. became an empty string: the ‘m’ flag for pymalloc became useless (builds with and without pymalloc are ABI compatible) and so has been removed. (Contributed by Victor Stinner in bpo-36707(1).) Example of changes: * Only ‘python3.8’ program is installed, ‘python3.8m’ program is gone. * Only ‘python3.8-config’ script is installed, ‘python3.8m-config’ script is gone. * The ‘m’ flag has been removed from the suffix of dynamic library filenames: extension modules in the standard library as well as those produced and installed by third-party packages, like those downloaded from PyPI. On Linux, for example, the Python 3.7 suffix ‘.cpython-37m-x86_64-linux-gnu.so’ became ‘.cpython-38-x86_64-linux-gnu.so’ in Python 3.8. * The header files have been reorganized to better separate the different kinds of APIs: * ‘Include/*.h’ should be the portable public stable C API. * ‘Include/cpython/*.h’ should be the unstable C API specific to CPython; public API, with some private API prefixed by ‘_Py’ or ‘_PY’. * ‘Include/internal/*.h’ is the private internal C API very specific to CPython. This API comes with no backward compatibility warranty and should not be used outside CPython. It is only exposed for very specific needs like debuggers and profiles which has to access to CPython internals without calling functions. This API is now installed by ‘make install’. (Contributed by Victor Stinner in bpo-35134(2) and bpo-35081(3), work initiated by Eric Snow in Python 3.7.) * Some macros have been converted to static inline functions: parameter types and return type are well defined, they don’t have issues specific to macros, variables have a local scopes. Examples: * *note Py_INCREF(): 265, *note Py_DECREF(): 266. * *note Py_XINCREF(): 267, *note Py_XDECREF(): 268. * ‘PyObject_INIT()’, ‘PyObject_INIT_VAR()’ * Private functions: ‘_PyObject_GC_TRACK()’, ‘_PyObject_GC_UNTRACK()’, ‘_Py_Dealloc()’ (Contributed by Victor Stinner in bpo-35059(4).) * The ‘PyByteArray_Init()’ and ‘PyByteArray_Fini()’ functions have been removed. They did nothing since Python 2.7.4 and Python 3.2.0, were excluded from the limited API (stable ABI), and were not documented. (Contributed by Victor Stinner in bpo-35713(5).) * The result of ‘PyExceptionClass_Name()’ is now of type ‘const char *’ rather of ‘char *’. (Contributed by Serhiy Storchaka in bpo-33818(6).) * The duality of ‘Modules/Setup.dist’ and ‘Modules/Setup’ has been removed. Previously, when updating the CPython source tree, one had to manually copy ‘Modules/Setup.dist’ (inside the source tree) to ‘Modules/Setup’ (inside the build tree) in order to reflect any changes upstream. This was of a small benefit to packagers at the expense of a frequent annoyance to developers following CPython development, as forgetting to copy the file could produce build failures. Now the build system always reads from ‘Modules/Setup’ inside the source tree. People who want to customize that file are encouraged to maintain their changes in a git fork of CPython or as patch files, as they would do for any other change to the source tree. (Contributed by Antoine Pitrou in bpo-32430(7).) * Functions that convert Python number to C integer like *note PyLong_AsLong(): 269. and argument parsing functions like *note PyArg_ParseTuple(): 26a. with integer converting format units like ‘'i'’ will now use the *note __index__(): 18a. special method instead of *note __int__(): 18b, if available. The deprecation warning will be emitted for objects with the ‘__int__()’ method but without the ‘__index__()’ method (like *note Decimal: 188. and *note Fraction: 185.). *note PyNumber_Check(): 26b. will now return ‘1’ for objects implementing ‘__index__()’. *note PyNumber_Long(): 26c, *note PyNumber_Float(): 26d. and *note PyFloat_AsDouble(): 26e. also now use the ‘__index__()’ method if available. (Contributed by Serhiy Storchaka in bpo-36048(8) and bpo-20092(9).) * Heap-allocated type objects will now increase their reference count in *note PyObject_Init(): 26f. (and its parallel macro ‘PyObject_INIT’) instead of in *note PyType_GenericAlloc(): 270. Types that modify instance allocation or deallocation may need to be adjusted. (Contributed by Eddie Elizondo in bpo-35810(10).) * The new function *note PyCode_NewWithPosOnlyArgs(): 271. allows to create code objects like *note PyCode_New(): 272, but with an extra `posonlyargcount' parameter for indicating the number of positional-only arguments. (Contributed by Pablo Galindo in bpo-37221(11).) * *note Py_SetPath(): 273. now sets *note sys.executable: 274. to the program full path (*note Py_GetProgramFullPath(): 275.) rather than to the program name (*note Py_GetProgramName(): 276.). (Contributed by Victor Stinner in bpo-38234(12).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36707 (2) https://bugs.python.org/issue35134 (3) https://bugs.python.org/issue35081 (4) https://bugs.python.org/issue35059 (5) https://bugs.python.org/issue35713 (6) https://bugs.python.org/issue33818 (7) https://bugs.python.org/issue32430 (8) https://bugs.python.org/issue36048 (9) https://bugs.python.org/issue20092 (10) https://bugs.python.org/issue35810 (11) https://bugs.python.org/issue37221 (12) https://bugs.python.org/issue38234  File: python.info, Node: Deprecated, Next: API and Feature Removals, Prev: Build and C API Changes, Up: What’s New In Python 3 8 1.1.8 Deprecated ---------------- * The distutils ‘bdist_wininst’ command is now deprecated, use ‘bdist_wheel’ (wheel packages) instead. (Contributed by Victor Stinner in bpo-37481(1).) * Deprecated methods ‘getchildren()’ and ‘getiterator()’ in the *note ElementTree: 137. module now emit a *note DeprecationWarning: 278. instead of *note PendingDeprecationWarning: 279. They will be removed in Python 3.9. (Contributed by Serhiy Storchaka in bpo-29209(2).) * Passing an object that is not an instance of *note concurrent.futures.ThreadPoolExecutor: 27a. to *note loop.set_default_executor(): 27b. is deprecated and will be prohibited in Python 3.9. (Contributed by Elvis Pranskevichus in bpo-34075(3).) * The *note __getitem__(): 27c. methods of *note xml.dom.pulldom.DOMEventStream: 27d, *note wsgiref.util.FileWrapper: 27e. and *note fileinput.FileInput: 27f. have been deprecated. Implementations of these methods have been ignoring their `index' parameter, and returning the next item instead. (Contributed by Berker Peksag in bpo-9372(4).) * The *note typing.NamedTuple: 280. class has deprecated the ‘_field_types’ attribute in favor of the ‘__annotations__’ attribute which has the same information. (Contributed by Raymond Hettinger in bpo-36320(5).) * *note ast: 8. classes ‘Num’, ‘Str’, ‘Bytes’, ‘NameConstant’ and ‘Ellipsis’ are considered deprecated and will be removed in future Python versions. ‘Constant’ should be used instead. (Contributed by Serhiy Storchaka in bpo-32892(6).) * *note ast.NodeVisitor: 281. methods ‘visit_Num()’, ‘visit_Str()’, ‘visit_Bytes()’, ‘visit_NameConstant()’ and ‘visit_Ellipsis()’ are deprecated now and will not be called in future Python versions. Add the ‘visit_Constant()’ method to handle all constant nodes. (Contributed by Serhiy Storchaka in bpo-36917(7).) * The *note asyncio.coroutine(): 282. *note decorator: 283. is deprecated and will be removed in version 3.10. Instead of ‘@asyncio.coroutine’, use *note async def: 284. instead. (Contributed by Andrew Svetlov in bpo-36921(8).) * In *note asyncio: a, the explicit passing of a `loop' argument has been deprecated and will be removed in version 3.10 for the following: *note asyncio.sleep(): 285, *note asyncio.gather(): 286, *note asyncio.shield(): 287, *note asyncio.wait_for(): 288, *note asyncio.wait(): 289, *note asyncio.as_completed(): 28a, *note asyncio.Task: 1ad, *note asyncio.Lock: 28b, *note asyncio.Event: 28c, *note asyncio.Condition: 28d, *note asyncio.Semaphore: 28e, *note asyncio.BoundedSemaphore: 28f, *note asyncio.Queue: 290, *note asyncio.create_subprocess_exec(): 291, and *note asyncio.create_subprocess_shell(): 292. * The explicit passing of coroutine objects to *note asyncio.wait(): 289. has been deprecated and will be removed in version 3.11. (Contributed by Yury Selivanov in bpo-34790(9).) * The following functions and methods are deprecated in the *note gettext: 89. module: *note lgettext(): 293, *note ldgettext(): 294, *note lngettext(): 295. and *note ldngettext(): 296. They return encoded bytes, and it’s possible that you will get unexpected Unicode-related exceptions if there are encoding problems with the translated strings. It’s much better to use alternatives which return Unicode strings in Python 3. These functions have been broken for a long time. Function *note bind_textdomain_codeset(): 297, methods *note output_charset(): 298. and *note set_output_charset(): 299, and the `codeset' parameter of functions *note translation(): 29a. and *note install(): 29b. are also deprecated, since they are only used for the ‘l*gettext()’ functions. (Contributed by Serhiy Storchaka in bpo-33710(10).) * The ‘isAlive()’ method of *note threading.Thread: 235. has been deprecated. (Contributed by Dong-hee Na in bpo-35283(11).) * Many builtin and extension functions that take integer arguments will now emit a deprecation warning for *note Decimal: 188.s, *note Fraction: 185.s and any other objects that can be converted to integers only with a loss (e.g. that have the *note __int__(): 18b. method but do not have the *note __index__(): 18a. method). In future version they will be errors. (Contributed by Serhiy Storchaka in bpo-36048(12).) * Deprecated passing the following arguments as keyword arguments: - `func' in *note functools.partialmethod(): 29c, *note weakref.finalize(): 29d, *note profile.Profile.runcall(): 29e, ‘cProfile.Profile.runcall()’, *note bdb.Bdb.runcall(): 29f, *note trace.Trace.runfunc(): 2a0. and *note curses.wrapper(): 2a1. - `function' in *note unittest.TestCase.addCleanup(): 2a2. - `fn' in the *note submit(): 2a3. method of *note concurrent.futures.ThreadPoolExecutor: 27a. and *note concurrent.futures.ProcessPoolExecutor: 2a4. - `callback' in *note contextlib.ExitStack.callback(): 2a5, ‘contextlib.AsyncExitStack.callback()’ and *note contextlib.AsyncExitStack.push_async_callback(): 2a6. - `c' and `typeid' in the ‘create()’ method of ‘multiprocessing.managers.Server’ and ‘multiprocessing.managers.SharedMemoryServer’. - `obj' in *note weakref.finalize(): 29d. In future releases of Python, they will be *note positional-only: 2a7. (Contributed by Serhiy Storchaka in bpo-36492(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue37481 (2) https://bugs.python.org/issue29209 (3) https://bugs.python.org/issue34075 (4) https://bugs.python.org/issue9372 (5) https://bugs.python.org/issue36320 (6) https://bugs.python.org/issue32892 (7) https://bugs.python.org/issue36917 (8) https://bugs.python.org/issue36921 (9) https://bugs.python.org/issue34790 (10) https://bugs.python.org/issue33710 (11) https://bugs.python.org/issue35283 (12) https://bugs.python.org/issue36048 (13) https://bugs.python.org/issue36492  File: python.info, Node: API and Feature Removals, Next: Porting to Python 3 8, Prev: Deprecated, Up: What’s New In Python 3 8 1.1.9 API and Feature Removals ------------------------------ The following features and APIs have been removed from Python 3.8: * Starting with Python 3.3, importing ABCs from *note collections: 1e. was deprecated, and importing should be done from *note collections.abc: 1f. Being able to import from collections was marked for removal in 3.8, but has been delayed to 3.9. (See bpo-36952(1).) * The ‘macpath’ module, deprecated in Python 3.7, has been removed. (Contributed by Victor Stinner in bpo-35471(2).) * The function ‘platform.popen()’ has been removed, after having been deprecated since Python 3.3: use *note os.popen(): 2a9. instead. (Contributed by Victor Stinner in bpo-35345(3).) * The function ‘time.clock()’ has been removed, after having been deprecated since Python 3.3: use *note time.perf_counter(): 2aa. or *note time.process_time(): 2ab. instead, depending on your requirements, to have well-defined behavior. (Contributed by Matthias Bussonnier in bpo-36895(4).) * The ‘pyvenv’ script has been removed in favor of ‘python3.8 -m venv’ to help eliminate confusion as to what Python interpreter the ‘pyvenv’ script is tied to. (Contributed by Brett Cannon in bpo-25427(5).) * ‘parse_qs’, ‘parse_qsl’, and ‘escape’ are removed from the *note cgi: 16. module. They are deprecated in Python 3.2 or older. They should be imported from the ‘urllib.parse’ and ‘html’ modules instead. * ‘filemode’ function is removed from the *note tarfile: 101. module. It is not documented and deprecated since Python 3.3. * The *note XMLParser: 252. constructor no longer accepts the `html' argument. It never had an effect and was deprecated in Python 3.4. All other parameters are now *note keyword-only: 2ac. (Contributed by Serhiy Storchaka in bpo-29209(6).) * Removed the ‘doctype()’ method of *note XMLParser: 252. (Contributed by Serhiy Storchaka in bpo-29209(7).) * “unicode_internal” codec is removed. (Contributed by Inada Naoki in bpo-36297(8).) * The ‘Cache’ and ‘Statement’ objects of the *note sqlite3: f2. module are not exposed to the user. (Contributed by Aviv Palivoda in bpo-30262(9).) * The ‘bufsize’ keyword argument of *note fileinput.input(): 2ad. and *note fileinput.FileInput(): 27f. which was ignored and deprecated since Python 3.6 has been removed. bpo-36952(10) (Contributed by Matthias Bussonnier.) * The functions ‘sys.set_coroutine_wrapper()’ and ‘sys.get_coroutine_wrapper()’ deprecated in Python 3.7 have been removed; bpo-36933(11) (Contributed by Matthias Bussonnier.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue36952 (2) https://bugs.python.org/issue35471 (3) https://bugs.python.org/issue35345 (4) https://bugs.python.org/issue36895 (5) https://bugs.python.org/issue25427 (6) https://bugs.python.org/issue29209 (7) https://bugs.python.org/issue29209 (8) https://bugs.python.org/issue36297 (9) https://bugs.python.org/issue30262 (10) https://bugs.python.org/issue36952 (11) https://bugs.python.org/issue36933  File: python.info, Node: Porting to Python 3 8, Next: Notable changes in Python 3 8 1, Prev: API and Feature Removals, Up: What’s New In Python 3 8 1.1.10 Porting to Python 3.8 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Changes in Python behavior:: * Changes in the Python API:: * Changes in the C API:: * CPython bytecode changes:: * Demos and Tools::  File: python.info, Node: Changes in Python behavior, Next: Changes in the Python API, Up: Porting to Python 3 8 1.1.10.1 Changes in Python behavior ................................... * Yield expressions (both ‘yield’ and ‘yield from’ clauses) are now disallowed in comprehensions and generator expressions (aside from the iterable expression in the leftmost ‘for’ clause). (Contributed by Serhiy Storchaka in bpo-10544(1).) * The compiler now produces a *note SyntaxWarning: 191. when identity checks (‘is’ and ‘is not’) are used with certain types of literals (e.g. strings, numbers). These can often work by accident in CPython, but are not guaranteed by the language spec. The warning advises users to use equality tests (‘==’ and ‘!=’) instead. (Contributed by Serhiy Storchaka in bpo-34850(2).) * The CPython interpreter can swallow exceptions in some circumstances. In Python 3.8 this happens in fewer cases. In particular, exceptions raised when getting the attribute from the type dictionary are no longer ignored. (Contributed by Serhiy Storchaka in bpo-35459(3).) * Removed ‘__str__’ implementations from builtin types *note bool: 183, *note int: 184, *note float: 187, *note complex: 189. and few classes from the standard library. They now inherit ‘__str__()’ from *note object: 2b0. As result, defining the ‘__repr__()’ method in the subclass of these classes will affect their string representation. (Contributed by Serhiy Storchaka in bpo-36793(4).) * On AIX, *note sys.platform: 2b1. doesn’t contain the major version anymore. It is always ‘'aix'’, instead of ‘'aix3'’ .. ‘'aix7'’. Since older Python versions include the version number, so it is recommended to always use ‘sys.platform.startswith('aix')’. (Contributed by M. Felt in bpo-36588(5).) * *note PyEval_AcquireLock(): 2b2. and *note PyEval_AcquireThread(): 2b3. now terminate the current thread if called while the interpreter is finalizing, making them consistent with *note PyEval_RestoreThread(): 2b4, *note Py_END_ALLOW_THREADS(): 2b5, and *note PyGILState_Ensure(): 2b6. If this behavior is not desired, guard the call by checking ‘_Py_IsFinalizing()’ or ‘sys.is_finalizing()’. (Contributed by Joannah Nanjekye in bpo-36475(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10544 (2) https://bugs.python.org/issue34850 (3) https://bugs.python.org/issue35459 (4) https://bugs.python.org/issue36793 (5) https://bugs.python.org/issue36588 (6) https://bugs.python.org/issue36475  File: python.info, Node: Changes in the Python API, Next: Changes in the C API, Prev: Changes in Python behavior, Up: Porting to Python 3 8 1.1.10.2 Changes in the Python API .................................. * The *note os.getcwdb(): 2b8. function now uses the UTF-8 encoding on Windows, rather than the ANSI code page: see PEP 529(1) for the rationale. The function is no longer deprecated on Windows. (Contributed by Victor Stinner in bpo-37412(2).) * *note subprocess.Popen: 2b9. can now use *note os.posix_spawn(): 257. in some cases for better performance. On Windows Subsystem for Linux and QEMU User Emulation, the ‘Popen’ constructor using *note os.posix_spawn(): 257. no longer raises an exception on errors like “missing program”. Instead the child process fails with a non-zero ‘returncode’. (Contributed by Joannah Nanjekye and Victor Stinner in bpo-35537(3).) * The `preexec_fn' argument of * *note subprocess.Popen: 2b9. is no longer compatible with subinterpreters. The use of the parameter in a subinterpreter now raises *note RuntimeError: 2ba. (Contributed by Eric Snow in bpo-34651(4), modified by Christian Heimes in bpo-37951(5).) * The ‘imap.IMAP4.logout()’ method no longer silently ignores arbitrary exceptions. (Contributed by Victor Stinner in bpo-36348(6).) * The function ‘platform.popen()’ has been removed, after having been deprecated since Python 3.3: use *note os.popen(): 2a9. instead. (Contributed by Victor Stinner in bpo-35345(7).) * The *note statistics.mode(): 2bb. function no longer raises an exception when given multimodal data. Instead, it returns the first mode encountered in the input data. (Contributed by Raymond Hettinger in bpo-35892(8).) * The *note selection(): 2bc. method of the *note tkinter.ttk.Treeview: 2bd. class no longer takes arguments. Using it with arguments for changing the selection was deprecated in Python 3.6. Use specialized methods like *note selection_set(): 2be. for changing the selection. (Contributed by Serhiy Storchaka in bpo-31508(9).) * The ‘writexml()’, ‘toxml()’ and ‘toprettyxml()’ methods of *note xml.dom.minidom: 135, and the ‘write()’ method of ‘xml.etree’, now preserve the attribute order specified by the user. (Contributed by Diego Rojas and Raymond Hettinger in bpo-34160(10).) * A *note dbm.dumb: 33. database opened with flags ‘'r'’ is now read-only. *note dbm.dumb.open(): 2bf. with flags ‘'r'’ and ‘'w'’ no longer creates a database if it does not exist. (Contributed by Serhiy Storchaka in bpo-32749(11).) * The ‘doctype()’ method defined in a subclass of *note XMLParser: 252. will no longer be called and will emit a *note RuntimeWarning: 2c0. instead of a *note DeprecationWarning: 278. Define the *note doctype(): 2c1. method on a target for handling an XML doctype declaration. (Contributed by Serhiy Storchaka in bpo-29209(12).) * A *note RuntimeError: 2ba. is now raised when the custom metaclass doesn’t provide the ‘__classcell__’ entry in the namespace passed to ‘type.__new__’. A *note DeprecationWarning: 278. was emitted in Python 3.6–3.7. (Contributed by Serhiy Storchaka in bpo-23722(13).) * The ‘cProfile.Profile’ class can now be used as a context manager. (Contributed by Scott Sanderson in bpo-29235(14).) * *note shutil.copyfile(): 258, *note shutil.copy(): 259, *note shutil.copy2(): 25a, *note shutil.copytree(): 21a. and *note shutil.move(): 25b. use platform-specific “fast-copy” syscalls (see *note Platform-dependent efficient copy operations: 25e. section). * *note shutil.copyfile(): 258. default buffer size on Windows was changed from 16 KiB to 1 MiB. * The ‘PyGC_Head’ struct has changed completely. All code that touched the struct member should be rewritten. (See bpo-33597(15).) * The *note PyInterpreterState: 2c2. struct has been moved into the “internal” header files (specifically Include/internal/pycore_pystate.h). An opaque ‘PyInterpreterState’ is still available as part of the public API (and stable ABI). The docs indicate that none of the struct’s fields are public, so we hope no one has been using them. However, if you do rely on one or more of those private fields and have no alternative then please open a BPO issue. We’ll work on helping you adjust (possibly including adding accessor functions to the public API). (See bpo-35886(16).) * The *note mmap.flush(): 2c3. method now returns ‘None’ on success and raises an exception on error under all platforms. Previously, its behavior was platform-dependent: a nonzero value was returned on success; zero was returned on error under Windows. A zero value was returned on success; an exception was raised on error under Unix. (Contributed by Berker Peksag in bpo-2122(17).) * *note xml.dom.minidom: 135. and *note xml.sax: 13b. modules no longer process external entities by default. (Contributed by Christian Heimes in bpo-17239(18).) * Deleting a key from a read-only *note dbm: 32. database (*note dbm.dumb: 33, *note dbm.gnu: 34. or *note dbm.ndbm: 35.) raises ‘error’ (*note dbm.dumb.error: 2c4, *note dbm.gnu.error: 2c5. or *note dbm.ndbm.error: 2c6.) instead of *note KeyError: 2c7. (Contributed by Xiang Zhang in bpo-33106(19).) * Simplified AST for literals. All constants will be represented as ‘ast.Constant’ instances. Instantiating old classes ‘Num’, ‘Str’, ‘Bytes’, ‘NameConstant’ and ‘Ellipsis’ will return an instance of ‘Constant’. (Contributed by Serhiy Storchaka in bpo-32892(20).) * *note expanduser(): 1fe. on Windows now prefers the ‘USERPROFILE’ environment variable and does not use ‘HOME’, which is not normally set for regular user accounts. (Contributed by Anthony Sottile in bpo-36264(21).) * The exception *note asyncio.CancelledError: 1a7. now inherits from *note BaseException: 1a8. rather than *note Exception: 1a9. and no longer inherits from *note concurrent.futures.CancelledError: 1aa. (Contributed by Yury Selivanov in bpo-32528(22).) * The function *note asyncio.wait_for(): 288. now correctly waits for cancellation when using an instance of *note asyncio.Task: 1ad. Previously, upon reaching `timeout', it was cancelled and immediately returned. (Contributed by Elvis Pranskevichus in bpo-32751(23).) * The function *note asyncio.BaseTransport.get_extra_info(): 2c8. now returns a safe to use socket object when ‘socket’ is passed to the `name' parameter. (Contributed by Yury Selivanov in bpo-37027(24).) * *note asyncio.BufferedProtocol: 2c9. has graduated to the stable API. * DLL dependencies for extension modules and DLLs loaded with *note ctypes: 2b. on Windows are now resolved more securely. Only the system paths, the directory containing the DLL or PYD file, and directories added with *note add_dll_directory(): 1c2. are searched for load-time dependencies. Specifically, ‘PATH’ and the current working directory are no longer used, and modifications to these will no longer have any effect on normal DLL resolution. If your application relies on these mechanisms, you should check for *note add_dll_directory(): 1c2. and if it exists, use it to add your DLLs directory while loading your library. Note that Windows 7 users will need to ensure that Windows Update KB2533623 has been installed (this is also verified by the installer). (Contributed by Steve Dower in bpo-36085(25).) * The header files and functions related to pgen have been removed after its replacement by a pure Python implementation. (Contributed by Pablo Galindo in bpo-36623(26).) * *note types.CodeType: 198. has a new parameter in the second position of the constructor (`posonlyargcount') to support positional-only arguments defined in PEP 570(27). The first argument (`argcount') now represents the total number of positional arguments (including positional-only arguments). The new ‘replace()’ method of *note types.CodeType: 198. can be used to make the code future-proof. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0529 (2) https://bugs.python.org/issue37412 (3) https://bugs.python.org/issue35537 (4) https://bugs.python.org/issue34651 (5) https://bugs.python.org/issue37951 (6) https://bugs.python.org/issue36348 (7) https://bugs.python.org/issue35345 (8) https://bugs.python.org/issue35892 (9) https://bugs.python.org/issue31508 (10) https://bugs.python.org/issue34160 (11) https://bugs.python.org/issue32749 (12) https://bugs.python.org/issue29209 (13) https://bugs.python.org/issue23722 (14) https://bugs.python.org/issue29235 (15) https://bugs.python.org/issue33597 (16) https://bugs.python.org/issue35886 (17) https://bugs.python.org/issue2122 (18) https://bugs.python.org/issue17239 (19) https://bugs.python.org/issue33106 (20) https://bugs.python.org/issue32892 (21) https://bugs.python.org/issue36264 (22) https://bugs.python.org/issue32528 (23) https://bugs.python.org/issue32751 (24) https://bugs.python.org/issue37027 (25) https://bugs.python.org/issue36085 (26) https://bugs.python.org/issue36623 (27) https://www.python.org/dev/peps/pep-0570  File: python.info, Node: Changes in the C API, Next: CPython bytecode changes, Prev: Changes in the Python API, Up: Porting to Python 3 8 1.1.10.3 Changes in the C API ............................. * The *note PyCompilerFlags: 2cc. structure got a new `cf_feature_version' field. It should be initialized to ‘PY_MINOR_VERSION’. The field is ignored by default, and is used if and only if ‘PyCF_ONLY_AST’ flag is set in `cf_flags'. (Contributed by Guido van Rossum in bpo-35766(1).) * The ‘PyEval_ReInitThreads()’ function has been removed from the C API. It should not be called explicitly: use *note PyOS_AfterFork_Child(): 2cd. instead. (Contributed by Victor Stinner in bpo-36728(2).) * On Unix, C extensions are no longer linked to libpython except on Android and Cygwin. When Python is embedded, ‘libpython’ must not be loaded with ‘RTLD_LOCAL’, but ‘RTLD_GLOBAL’ instead. Previously, using ‘RTLD_LOCAL’, it was already not possible to load C extensions which were not linked to ‘libpython’, like C extensions of the standard library built by the ‘*shared*’ section of ‘Modules/Setup’. (Contributed by Victor Stinner in bpo-21536(3).) * Use of ‘#’ variants of formats in parsing or building value (e.g. *note PyArg_ParseTuple(): 26a, *note Py_BuildValue(): 2ce, *note PyObject_CallFunction(): 2cf, etc.) without ‘PY_SSIZE_T_CLEAN’ defined raises ‘DeprecationWarning’ now. It will be removed in 3.10 or 4.0. Read *note Parsing arguments and building values: 2d0. for detail. (Contributed by Inada Naoki in bpo-36381(4).) * Instances of heap-allocated types (such as those created with *note PyType_FromSpec(): 2d1.) hold a reference to their type object. Increasing the reference count of these type objects has been moved from *note PyType_GenericAlloc(): 270. to the more low-level functions, *note PyObject_Init(): 26f. and ‘PyObject_INIT()’. This makes types created through *note PyType_FromSpec(): 2d1. behave like other classes in managed code. Statically allocated types are not affected. For the vast majority of cases, there should be no side effect. However, types that manually increase the reference count after allocating an instance (perhaps to work around the bug) may now become immortal. To avoid this, these classes need to call Py_DECREF on the type object during instance deallocation. To correctly port these types into 3.8, please apply the following changes: * Remove *note Py_INCREF: 265. on the type object after allocating an instance - if any. This may happen after calling *note PyObject_New(): 2d2, *note PyObject_NewVar(): 2d3, *note PyObject_GC_New(): 2d4, *note PyObject_GC_NewVar(): 2d5, or any other custom allocator that uses *note PyObject_Init(): 26f. or ‘PyObject_INIT()’. Example: static foo_struct * foo_new(PyObject *type) { foo_struct *foo = PyObject_GC_New(foo_struct, (PyTypeObject *) type); if (foo == NULL) return NULL; #if PY_VERSION_HEX < 0x03080000 // Workaround for Python issue 35810; no longer necessary in Python 3.8 PY_INCREF(type) #endif return foo; } * Ensure that all custom ‘tp_dealloc’ functions of heap-allocated types decrease the type’s reference count. Example: static void foo_dealloc(foo_struct *instance) { PyObject *type = Py_TYPE(instance); PyObject_GC_Del(instance); #if PY_VERSION_HEX >= 0x03080000 // This was not needed before Python 3.8 (Python issue 35810) Py_DECREF(type); #endif } (Contributed by Eddie Elizondo in bpo-35810(5).) * The ‘Py_DEPRECATED()’ macro has been implemented for MSVC. The macro now must be placed before the symbol name. Example: Py_DEPRECATED(3.8) PyAPI_FUNC(int) Py_OldFunction(void); (Contributed by Zackery Spytz in bpo-33407(6).) * The interpreter does not pretend to support binary compatibility of extension types across feature releases, anymore. A *note PyTypeObject: 2d6. exported by a third-party extension module is supposed to have all the slots expected in the current Python version, including *note tp_finalize: 2d7. (*note Py_TPFLAGS_HAVE_FINALIZE: 2d8. is not checked anymore before reading *note tp_finalize: 2d7.). (Contributed by Antoine Pitrou in bpo-32388(7).) * The functions ‘PyNode_AddChild()’ and ‘PyParser_AddToken()’ now accept two additional ‘int’ arguments `end_lineno' and `end_col_offset'. * The ‘libpython38.a’ file to allow MinGW tools to link directly against ‘python38.dll’ is no longer included in the regular Windows distribution. If you require this file, it may be generated with the ‘gendef’ and ‘dlltool’ tools, which are part of the MinGW binutils package: gendef - python38.dll > tmp.def dlltool --dllname python38.dll --def tmp.def --output-lib libpython38.a The location of an installed ‘pythonXY.dll’ will depend on the installation options and the version and language of Windows. See *note Using Python on Windows: 2d9. for more information. The resulting library should be placed in the same directory as ‘pythonXY.lib’, which is generally the ‘libs’ directory under your Python installation. (Contributed by Steve Dower in bpo-37351(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue35766 (2) https://bugs.python.org/issue36728 (3) https://bugs.python.org/issue21536 (4) https://bugs.python.org/issue36381 (5) https://bugs.python.org/issue35810 (6) https://bugs.python.org/issue33407 (7) https://bugs.python.org/issue32388 (8) https://bugs.python.org/issue37351  File: python.info, Node: CPython bytecode changes, Next: Demos and Tools, Prev: Changes in the C API, Up: Porting to Python 3 8 1.1.10.4 CPython bytecode changes ................................. * The interpreter loop has been simplified by moving the logic of unrolling the stack of blocks into the compiler. The compiler emits now explicit instructions for adjusting the stack of values and calling the cleaning-up code for *note break: 2db, *note continue: 181. and *note return: 190. Removed opcodes ‘BREAK_LOOP’, ‘CONTINUE_LOOP’, ‘SETUP_LOOP’ and ‘SETUP_EXCEPT’. Added new opcodes *note ROT_FOUR: 2dc, *note BEGIN_FINALLY: 2dd, *note CALL_FINALLY: 2de. and *note POP_FINALLY: 2df. Changed the behavior of *note END_FINALLY: 2e0. and *note WITH_CLEANUP_START: 2e1. (Contributed by Mark Shannon, Antoine Pitrou and Serhiy Storchaka in bpo-17611(1).) * Added new opcode *note END_ASYNC_FOR: 2e2. for handling exceptions raised when awaiting a next item in an *note async for: 2e3. loop. (Contributed by Serhiy Storchaka in bpo-33041(2).) * The *note MAP_ADD: 2e4. now expects the value as the first element in the stack and the key as the second element. This change was made so the key is always evaluated before the value in dictionary comprehensions, as proposed by PEP 572(3). (Contributed by Jörn Heissler in bpo-35224(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17611 (2) https://bugs.python.org/issue33041 (3) https://www.python.org/dev/peps/pep-0572 (4) https://bugs.python.org/issue35224  File: python.info, Node: Demos and Tools, Prev: CPython bytecode changes, Up: Porting to Python 3 8 1.1.10.5 Demos and Tools ........................ Added a benchmark script for timing various ways to access variables: ‘Tools/scripts/var_access_benchmark.py’. (Contributed by Raymond Hettinger in bpo-35884(1).) Here’s a summary of performance improvements since Python 3.3: Python version 3.3 3.4 3.5 3.6 3.7 3.8 -------------- --- --- --- --- --- --- Variable and attribute read access: read_local 4.0 7.1 7.1 5.4 5.1 3.9 read_nonlocal 5.3 7.1 8.1 5.8 5.4 4.4 read_global 13.3 15.5 19.0 14.3 13.6 7.6 read_builtin 20.0 21.1 21.6 18.5 19.0 7.5 read_classvar_from_class 20.5 25.6 26.5 20.7 19.5 18.4 read_classvar_from_instance 18.5 22.8 23.5 18.8 17.1 16.4 read_instancevar 26.8 32.4 33.1 28.0 26.3 25.4 read_instancevar_slots 23.7 27.8 31.3 20.8 20.8 20.2 read_namedtuple 68.5 73.8 57.5 45.0 46.8 18.4 read_boundmethod 29.8 37.6 37.9 29.6 26.9 27.7 Variable and attribute write access: write_local 4.6 8.7 9.3 5.5 5.3 4.3 write_nonlocal 7.3 10.5 11.1 5.6 5.5 4.7 write_global 15.9 19.7 21.2 18.0 18.0 15.8 write_classvar 81.9 92.9 96.0 104.6 102.1 39.2 write_instancevar 36.4 44.6 45.8 40.0 38.9 35.5 write_instancevar_slots 28.7 35.6 36.1 27.3 26.6 25.7 Data structure read access: read_list 19.2 24.2 24.5 20.8 20.8 19.0 read_deque 19.9 24.7 25.5 20.2 20.6 19.8 read_dict 19.7 24.3 25.7 22.3 23.0 21.0 read_strdict 17.9 22.6 24.3 19.5 21.2 18.9 Data structure write access: write_list 21.2 27.1 28.5 22.5 21.6 20.0 write_deque 23.8 28.7 30.1 22.7 21.8 23.5 write_dict 25.9 31.4 33.3 29.3 29.2 24.7 write_strdict 22.9 28.4 29.9 27.5 25.2 23.1 Stack (or queue) operations: list_append_pop 144.2 93.4 112.7 75.4 74.2 50.8 deque_append_pop 30.4 43.5 57.0 49.4 49.2 42.5 deque_append_popleft 30.8 43.7 57.3 49.7 49.7 42.8 Timing loop: loop_overhead 0.3 0.5 0.6 0.4 0.3 0.3 The benchmarks were measured on an Intel® Core™ i7-4960HQ processor(2) running the macOS 64-bit builds found at python.org(3). The benchmark script displays timings in nanoseconds. ---------- Footnotes ---------- (1) https://bugs.python.org/issue35884 (2) https://ark.intel.com/content/www/us/en/ark/products/76088/intel-core-i7-4960hq-processor-6m-cache-up-to-3-80-ghz.html (3) https://www.python.org/downloads/mac-osx/  File: python.info, Node: Notable changes in Python 3 8 1, Next: Notable changes in Python 3 8 2, Prev: Porting to Python 3 8, Up: What’s New In Python 3 8 1.1.11 Notable changes in Python 3.8.1 -------------------------------------- Due to significant security concerns, the `reuse_address' parameter of *note asyncio.loop.create_datagram_endpoint(): 2e7. is no longer supported. This is because of the behavior of the socket option ‘SO_REUSEADDR’ in UDP. For more details, see the documentation for ‘loop.create_datagram_endpoint()’. (Contributed by Kyle Stanley, Antoine Pitrou, and Yury Selivanov in bpo-37228(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue37228  File: python.info, Node: Notable changes in Python 3 8 2, Next: Notable changes in Python 3 8 3, Prev: Notable changes in Python 3 8 1, Up: What’s New In Python 3 8 1.1.12 Notable changes in Python 3.8.2 -------------------------------------- Fixed a regression with the ‘ignore’ callback of *note shutil.copytree(): 21a. The argument types are now str and List[str] again. (Contributed by Manuel Barkhau and Giampaolo Rodola in bpo-39390(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue39390  File: python.info, Node: Notable changes in Python 3 8 3, Next: Notable changes in Python 3 8 8, Prev: Notable changes in Python 3 8 2, Up: What’s New In Python 3 8 1.1.13 Notable changes in Python 3.8.3 -------------------------------------- The constant values of future flags in the *note __future__: 0. module are updated in order to prevent collision with compiler flags. Previously ‘PyCF_ALLOW_TOP_LEVEL_AWAIT’ was clashing with ‘CO_FUTURE_DIVISION’. (Contributed by Batuhan Taskaya in bpo-39562(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue39562  File: python.info, Node: Notable changes in Python 3 8 8, Next: Notable changes in Python 3 8 9, Prev: Notable changes in Python 3 8 3, Up: What’s New In Python 3 8 1.1.14 Notable changes in Python 3.8.8 -------------------------------------- Earlier Python versions allowed using both ‘;’ and ‘&’ as query parameter separators in *note urllib.parse.parse_qs(): 2eb. and *note urllib.parse.parse_qsl(): 2ec. Due to security concerns, and to conform with newer W3C recommendations, this has been changed to allow only a single separator key, with ‘&’ as the default. This change also affects *note cgi.parse(): 2ed. and *note cgi.parse_multipart(): 2ee. as they use the affected functions internally. For more details, please see their respective documentation. (Contributed by Adam Goldschmidt, Senthil Kumaran and Ken Jin in bpo-42967(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue42967  File: python.info, Node: Notable changes in Python 3 8 9, Prev: Notable changes in Python 3 8 8, Up: What’s New In Python 3 8 1.1.15 Notable changes in Python 3.8.9 -------------------------------------- A security fix alters the *note ftplib.FTP: 2f0. behavior to not trust the IPv4 address sent from the remote server when setting up a passive data channel. We reuse the ftp server IP address instead. For unusual code requiring the old behavior, set a ‘trust_server_pasv_ipv4_address’ attribute on your FTP instance to ‘True’. (See bpo-43285(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue43285  File: python.info, Node: What’s New In Python 3 7, Next: What’s New In Python 3 6, Prev: What’s New In Python 3 8, Up: What’s New in Python 1.2 What’s New In Python 3.7 ============================ Editor: Elvis Pranskevichus <> This article explains the new features in Python 3.7, compared to 3.6. Python 3.7 was released on June 27, 2018. For full details, see the *note changelog: 14c. * Menu: * Summary – Release Highlights:: * New Features: New Features<2>. * Other Language Changes: Other Language Changes<2>. * New Modules: New Modules<2>. * Improved Modules: Improved Modules<2>. * C API Changes:: * Build Changes:: * Optimizations: Optimizations<2>. * Other CPython Implementation Changes:: * Deprecated Python Behavior:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods. * Deprecated functions and types of the C API:: * Platform Support Removals:: * API and Feature Removals: API and Feature Removals<2>. * Module Removals:: * Windows-only Changes:: * Porting to Python 3.7: Porting to Python 3 7. * Notable changes in Python 3.7.1: Notable changes in Python 3 7 1. * Notable changes in Python 3.7.2: Notable changes in Python 3 7 2. * Notable changes in Python 3.7.6: Notable changes in Python 3 7 6. * Notable changes in Python 3.7.10: Notable changes in Python 3 7 10.  File: python.info, Node: Summary – Release Highlights, Next: New Features<2>, Up: What’s New In Python 3 7 1.2.1 Summary – Release Highlights ---------------------------------- New syntax features: * *note PEP 563: 2f4, postponed evaluation of type annotations. Backwards incompatible syntax changes: * *note async: 1a2. and *note await: 1a3. are now reserved keywords. New library modules: * *note contextvars: 25.: *note PEP 567 – Context Variables: 2f5. * *note dataclasses: 30.: *note PEP 557 – Data Classes: 2f6. * *note importlib.resources: 2f7. New built-in features: * *note PEP 553: 2f8, the new *note breakpoint(): 2f9. function. Python data model improvements: * *note PEP 562: 2fa, customization of access to module attributes. * *note PEP 560: 2fb, core support for typing module and generic types. * the insertion-order preservation nature of *note dict: 2fc. objects has been declared(1) to be an official part of the Python language spec. Significant improvements in the standard library: * The *note asyncio: a. module has received new features, significant *note usability and performance improvements: 2fd. * The *note time: 10a. module gained support for *note functions with nanosecond resolution: 2fe. CPython implementation improvements: * Avoiding the use of ASCII as a default text encoding: * *note PEP 538: 2ff, legacy C locale coercion * *note PEP 540: 300, forced UTF-8 runtime mode * *note PEP 552: 301, deterministic .pycs * *note the new development runtime mode: 302. * *note PEP 565: 303, improved *note DeprecationWarning: 278. handling C API improvements: * *note PEP 539: 304, new C API for thread-local storage Documentation improvements: * *note PEP 545: 305, Python documentation translations * New documentation translations: Japanese(2), French(3), and Korean(4). This release features notable performance improvements in many areas. The *note Optimizations: 306. section lists them in detail. For a list of changes that may affect compatibility with previous Python releases please refer to the *note Porting to Python 3.7: 307. section. ---------- Footnotes ---------- (1) https://mail.python.org/pipermail/python-dev/2017-December/151283.html (2) https://docs.python.org/ja/ (3) https://docs.python.org/fr/ (4) https://docs.python.org/ko/  File: python.info, Node: New Features<2>, Next: Other Language Changes<2>, Prev: Summary – Release Highlights, Up: What’s New In Python 3 7 1.2.2 New Features ------------------ * Menu: * PEP 563; Postponed Evaluation of Annotations: PEP 563 Postponed Evaluation of Annotations. * PEP 538; Legacy C Locale Coercion: PEP 538 Legacy C Locale Coercion. * PEP 540; Forced UTF-8 Runtime Mode: PEP 540 Forced UTF-8 Runtime Mode. * PEP 553; Built-in breakpoint(): PEP 553 Built-in breakpoint. * PEP 539; New C API for Thread-Local Storage: PEP 539 New C API for Thread-Local Storage. * PEP 562; Customization of Access to Module Attributes: PEP 562 Customization of Access to Module Attributes. * PEP 564; New Time Functions With Nanosecond Resolution: PEP 564 New Time Functions With Nanosecond Resolution. * PEP 565; Show DeprecationWarning in __main__: PEP 565 Show DeprecationWarning in __main__. * PEP 560; Core Support for typing module and Generic Types: PEP 560 Core Support for typing module and Generic Types. * PEP 552; Hash-based .pyc Files: PEP 552 Hash-based pyc Files. * PEP 545; Python Documentation Translations: PEP 545 Python Documentation Translations. * Development Runtime Mode; -X dev: Development Runtime Mode -X dev.  File: python.info, Node: PEP 563 Postponed Evaluation of Annotations, Next: PEP 538 Legacy C Locale Coercion, Up: New Features<2> 1.2.2.1 PEP 563: Postponed Evaluation of Annotations .................................................... The advent of type hints in Python uncovered two glaring usability issues with the functionality of annotations added in PEP 3107(1) and refined further in PEP 526(2): * annotations could only use names which were already available in the current scope, in other words they didn’t support forward references of any kind; and * annotating source code had adverse effects on startup time of Python programs. Both of these issues are fixed by postponing the evaluation of annotations. Instead of compiling code which executes expressions in annotations at their definition time, the compiler stores the annotation in a string form equivalent to the AST of the expression in question. If needed, annotations can be resolved at runtime using *note typing.get_type_hints(): 30a. In the common case where this is not required, the annotations are cheaper to store (since short strings are interned by the interpreter) and make startup time faster. Usability-wise, annotations now support forward references, making the following syntax valid: class C: @classmethod def from_string(cls, source: str) -> C: ... def validate_b(self, obj: B) -> bool: ... class B: ... Since this change breaks compatibility, the new behavior needs to be enabled on a per-module basis in Python 3.7 using a *note __future__: 0. import: from __future__ import annotations It will become the default in Python 3.10. See also ........ PEP 563(3) – Postponed evaluation of annotations PEP written and implemented by Łukasz Langa. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3107 (2) https://www.python.org/dev/peps/pep-0526 (3) https://www.python.org/dev/peps/pep-0563  File: python.info, Node: PEP 538 Legacy C Locale Coercion, Next: PEP 540 Forced UTF-8 Runtime Mode, Prev: PEP 563 Postponed Evaluation of Annotations, Up: New Features<2> 1.2.2.2 PEP 538: Legacy C Locale Coercion ......................................... An ongoing challenge within the Python 3 series has been determining a sensible default strategy for handling the “7-bit ASCII” text encoding assumption currently implied by the use of the default C or POSIX locale on non-Windows platforms. PEP 538(1) updates the default interpreter command line interface to automatically coerce that locale to an available UTF-8 based locale as described in the documentation of the new *note PYTHONCOERCECLOCALE: 30c. environment variable. Automatically setting ‘LC_CTYPE’ this way means that both the core interpreter and locale-aware C extensions (such as *note readline: de.) will assume the use of UTF-8 as the default text encoding, rather than ASCII. The platform support definition in PEP 11(2) has also been updated to limit full text handling support to suitably configured non-ASCII based locales. As part of this change, the default error handler for *note stdin: 30d. and *note stdout: 30e. is now ‘surrogateescape’ (rather than ‘strict’) when using any of the defined coercion target locales (currently ‘C.UTF-8’, ‘C.utf8’, and ‘UTF-8’). The default error handler for *note stderr: 30f. continues to be ‘backslashreplace’, regardless of locale. Locale coercion is silent by default, but to assist in debugging potentially locale related integration problems, explicit warnings (emitted directly on *note stderr: 30f.) can be requested by setting ‘PYTHONCOERCECLOCALE=warn’. This setting will also cause the Python runtime to emit a warning if the legacy C locale remains active when the core interpreter is initialized. While PEP 538(3)’s locale coercion has the benefit of also affecting extension modules (such as GNU ‘readline’), as well as child processes (including those running non-Python applications and older versions of Python), it has the downside of requiring that a suitable target locale be present on the running system. To better handle the case where no suitable target locale is available (as occurs on RHEL/CentOS 7, for example), Python 3.7 also implements *note PEP 540; Forced UTF-8 Runtime Mode: 300. See also ........ PEP 538(4) – Coercing the legacy C locale to a UTF-8 based locale PEP written and implemented by Nick Coghlan. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0538 (2) https://www.python.org/dev/peps/pep-0011 (3) https://www.python.org/dev/peps/pep-0538 (4) https://www.python.org/dev/peps/pep-0538  File: python.info, Node: PEP 540 Forced UTF-8 Runtime Mode, Next: PEP 553 Built-in breakpoint, Prev: PEP 538 Legacy C Locale Coercion, Up: New Features<2> 1.2.2.3 PEP 540: Forced UTF-8 Runtime Mode .......................................... The new *note -X: 155. ‘utf8’ command line option and *note PYTHONUTF8: 311. environment variable can be used to enable the CPython `UTF-8 mode'. When in UTF-8 mode, CPython ignores the locale settings, and uses the UTF-8 encoding by default. The error handlers for *note sys.stdin: 30d. and *note sys.stdout: 30e. streams are set to ‘surrogateescape’. The forced UTF-8 mode can be used to change the text handling behavior in an embedded Python interpreter without changing the locale settings of an embedding application. While PEP 540(1)’s UTF-8 mode has the benefit of working regardless of which locales are available on the running system, it has the downside of having no effect on extension modules (such as GNU ‘readline’), child processes running non-Python applications, and child processes running older versions of Python. To reduce the risk of corrupting text data when communicating with such components, Python 3.7 also implements *note PEP 540; Forced UTF-8 Runtime Mode: 300.). The UTF-8 mode is enabled by default when the locale is ‘C’ or ‘POSIX’, and the PEP 538(2) locale coercion feature fails to change it to a UTF-8 based alternative (whether that failure is due to ‘PYTHONCOERCECLOCALE=0’ being set, ‘LC_ALL’ being set, or the lack of a suitable target locale). See also ........ PEP 540(3) – Add a new UTF-8 mode PEP written and implemented by Victor Stinner ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0540 (2) https://www.python.org/dev/peps/pep-0538 (3) https://www.python.org/dev/peps/pep-0540  File: python.info, Node: PEP 553 Built-in breakpoint, Next: PEP 539 New C API for Thread-Local Storage, Prev: PEP 540 Forced UTF-8 Runtime Mode, Up: New Features<2> 1.2.2.4 PEP 553: Built-in ‘breakpoint()’ ........................................ Python 3.7 includes the new built-in *note breakpoint(): 2f9. function as an easy and consistent way to enter the Python debugger. Built-in ‘breakpoint()’ calls *note sys.breakpointhook(): 313. By default, the latter imports *note pdb: c9. and then calls ‘pdb.set_trace()’, but by binding ‘sys.breakpointhook()’ to the function of your choosing, ‘breakpoint()’ can enter any debugger. Additionally, the environment variable *note PYTHONBREAKPOINT: 314. can be set to the callable of your debugger of choice. Set ‘PYTHONBREAKPOINT=0’ to completely disable built-in ‘breakpoint()’. See also ........ PEP 553(1) – Built-in breakpoint() PEP written and implemented by Barry Warsaw ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0553  File: python.info, Node: PEP 539 New C API for Thread-Local Storage, Next: PEP 562 Customization of Access to Module Attributes, Prev: PEP 553 Built-in breakpoint, Up: New Features<2> 1.2.2.5 PEP 539: New C API for Thread-Local Storage ................................................... While Python provides a C API for thread-local storage support; the existing *note Thread Local Storage (TLS) API: 316. has used ‘int’ to represent TLS keys across all platforms. This has not generally been a problem for officially-support platforms, but that is neither POSIX-compliant, nor portable in any practical sense. PEP 539(1) changes this by providing a new *note Thread Specific Storage (TSS) API: 317. to CPython which supersedes use of the existing TLS API within the CPython interpreter, while deprecating the existing API. The TSS API uses a new type *note Py_tss_t: 318. instead of ‘int’ to represent TSS keys–an opaque type the definition of which may depend on the underlying TLS implementation. Therefore, this will allow to build CPython on platforms where the native TLS key is defined in a way that cannot be safely cast to ‘int’. Note that on platforms where the native TLS key is defined in a way that cannot be safely cast to ‘int’, all functions of the existing TLS API will be no-op and immediately return failure. This indicates clearly that the old API is not supported on platforms where it cannot be used reliably, and that no effort will be made to add such support. See also ........ PEP 539(2) – A New C-API for Thread-Local Storage in CPython PEP written by Erik M. Bray; implementation by Masayuki Yamamoto. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0539 (2) https://www.python.org/dev/peps/pep-0539  File: python.info, Node: PEP 562 Customization of Access to Module Attributes, Next: PEP 564 New Time Functions With Nanosecond Resolution, Prev: PEP 539 New C API for Thread-Local Storage, Up: New Features<2> 1.2.2.6 PEP 562: Customization of Access to Module Attributes ............................................................. Python 3.7 allows defining *note __getattr__(): 31a. on modules and will call it whenever a module attribute is otherwise not found. Defining *note __dir__(): 31b. on modules is now also allowed. A typical example of where this may be useful is module attribute deprecation and lazy loading. See also ........ PEP 562(1) – Module ‘__getattr__’ and ‘__dir__’ PEP written and implemented by Ivan Levkivskyi ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0562  File: python.info, Node: PEP 564 New Time Functions With Nanosecond Resolution, Next: PEP 565 Show DeprecationWarning in __main__, Prev: PEP 562 Customization of Access to Module Attributes, Up: New Features<2> 1.2.2.7 PEP 564: New Time Functions With Nanosecond Resolution .............................................................. The resolution of clocks in modern systems can exceed the limited precision of a floating point number returned by the *note time.time(): 31d. function and its variants. To avoid loss of precision, PEP 564(1) adds six new “nanosecond” variants of the existing timer functions to the *note time: 10a. module: * *note time.clock_gettime_ns(): 31e. * *note time.clock_settime_ns(): 31f. * *note time.monotonic_ns(): 320. * *note time.perf_counter_ns(): 321. * *note time.process_time_ns(): 322. * *note time.time_ns(): 323. The new functions return the number of nanoseconds as an integer value. Measurements(2) show that on Linux and Windows the resolution of *note time.time_ns(): 323. is approximately 3 times better than that of *note time.time(): 31d. See also ........ PEP 564(3) – Add new time functions with nanosecond resolution PEP written and implemented by Victor Stinner ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0564 (2) https://www.python.org/dev/peps/pep-0564/#annex-clocks-resolution-in-python (3) https://www.python.org/dev/peps/pep-0564  File: python.info, Node: PEP 565 Show DeprecationWarning in __main__, Next: PEP 560 Core Support for typing module and Generic Types, Prev: PEP 564 New Time Functions With Nanosecond Resolution, Up: New Features<2> 1.2.2.8 PEP 565: Show DeprecationWarning in ‘__main__’ ...................................................... The default handling of *note DeprecationWarning: 278. has been changed such that these warnings are once more shown by default, but only when the code triggering them is running directly in the *note __main__: 1. module. As a result, developers of single file scripts and those using Python interactively should once again start seeing deprecation warnings for the APIs they use, but deprecation warnings triggered by imported application, library and framework modules will continue to be hidden by default. As a result of this change, the standard library now allows developers to choose between three different deprecation warning behaviours: * *note FutureWarning: 325.: always displayed by default, recommended for warnings intended to be seen by application end users (e.g. for deprecated application configuration settings). * *note DeprecationWarning: 278.: displayed by default only in *note __main__: 1. and when running tests, recommended for warnings intended to be seen by other Python developers where a version upgrade may result in changed behaviour or an error. * *note PendingDeprecationWarning: 279.: displayed by default only when running tests, intended for cases where a future version upgrade will change the warning category to *note DeprecationWarning: 278. or *note FutureWarning: 325. Previously both *note DeprecationWarning: 278. and *note PendingDeprecationWarning: 279. were only visible when running tests, which meant that developers primarily writing single file scripts or using Python interactively could be surprised by breaking changes in the APIs they used. See also ........ PEP 565(1) – Show DeprecationWarning in ‘__main__’ PEP written and implemented by Nick Coghlan ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0565  File: python.info, Node: PEP 560 Core Support for typing module and Generic Types, Next: PEP 552 Hash-based pyc Files, Prev: PEP 565 Show DeprecationWarning in __main__, Up: New Features<2> 1.2.2.9 PEP 560: Core Support for ‘typing’ module and Generic Types ................................................................... Initially PEP 484(1) was designed in such way that it would not introduce `any' changes to the core CPython interpreter. Now type hints and the *note typing: 119. module are extensively used by the community, so this restriction is removed. The PEP introduces two special methods *note __class_getitem__(): 327. and ‘__mro_entries__’, these methods are now used by most classes and special constructs in *note typing: 119. As a result, the speed of various operations with types increased up to 7 times, the generic types can be used without metaclass conflicts, and several long standing bugs in *note typing: 119. module are fixed. See also ........ PEP 560(2) – Core support for typing module and generic types PEP written and implemented by Ivan Levkivskyi ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0560  File: python.info, Node: PEP 552 Hash-based pyc Files, Next: PEP 545 Python Documentation Translations, Prev: PEP 560 Core Support for typing module and Generic Types, Up: New Features<2> 1.2.2.10 PEP 552: Hash-based .pyc Files ....................................... Python has traditionally checked the up-to-dateness of bytecode cache files (i.e., ‘.pyc’ files) by comparing the source metadata (last-modified timestamp and size) with source metadata saved in the cache file header when it was generated. While effective, this invalidation method has its drawbacks. When filesystem timestamps are too coarse, Python can miss source updates, leading to user confusion. Additionally, having a timestamp in the cache file is problematic for build reproducibility(1) and content-based build systems. PEP 552(2) extends the pyc format to allow the hash of the source file to be used for invalidation instead of the source timestamp. Such ‘.pyc’ files are called “hash-based”. By default, Python still uses timestamp-based invalidation and does not generate hash-based ‘.pyc’ files at runtime. Hash-based ‘.pyc’ files may be generated with *note py_compile: d7. or *note compileall: 21. Hash-based ‘.pyc’ files come in two variants: checked and unchecked. Python validates checked hash-based ‘.pyc’ files against the corresponding source files at runtime but doesn’t do so for unchecked hash-based pycs. Unchecked hash-based ‘.pyc’ files are a useful performance optimization for environments where a system external to Python (e.g., the build system) is responsible for keeping ‘.pyc’ files up-to-date. See *note Cached bytecode invalidation: 329. for more information. See also ........ PEP 552(3) – Deterministic pycs PEP written and implemented by Benjamin Peterson ---------- Footnotes ---------- (1) https://reproducible-builds.org/ (2) https://www.python.org/dev/peps/pep-0552 (3) https://www.python.org/dev/peps/pep-0552  File: python.info, Node: PEP 545 Python Documentation Translations, Next: Development Runtime Mode -X dev, Prev: PEP 552 Hash-based pyc Files, Up: New Features<2> 1.2.2.11 PEP 545: Python Documentation Translations ................................................... PEP 545(1) describes the process of creating and maintaining Python documentation translations. Three new translations have been added: - Japanese: ‘https://docs.python.org/ja/’ - French: ‘https://docs.python.org/fr/’ - Korean: ‘https://docs.python.org/ko/’ See also ........ PEP 545(2) – Python Documentation Translations PEP written and implemented by Julien Palard, Inada Naoki, and Victor Stinner. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0545 (2) https://www.python.org/dev/peps/pep-0545  File: python.info, Node: Development Runtime Mode -X dev, Prev: PEP 545 Python Documentation Translations, Up: New Features<2> 1.2.2.12 Development Runtime Mode: -X dev ......................................... The new *note -X: 155. ‘dev’ command line option or the new *note PYTHONDEVMODE: 32c. environment variable can be used to enable CPython’s `development mode'. When in development mode, CPython performs additional runtime checks that are too expensive to be enabled by default. See *note -X: 155. ‘dev’ documentation for the full description of the effects of this mode.  File: python.info, Node: Other Language Changes<2>, Next: New Modules<2>, Prev: New Features<2>, Up: What’s New In Python 3 7 1.2.3 Other Language Changes ---------------------------- * An *note await: 1a3. expression and comprehensions containing an *note async for: 2e3. clause were illegal in the expressions in *note formatted string literals: 15c. due to a problem with the implementation. In Python 3.7 this restriction was lifted. * More than 255 arguments can now be passed to a function, and a function can now have more than 255 parameters. (Contributed by Serhiy Storchaka in bpo-12844(1) and bpo-18896(2).) * *note bytes.fromhex(): 32e. and *note bytearray.fromhex(): 32f. now ignore all ASCII whitespace, not only spaces. (Contributed by Robert Xiao in bpo-28927(3).) * *note str: 330, *note bytes: 331, and *note bytearray: 332. gained support for the new *note isascii(): 333. method, which can be used to test if a string or bytes contain only the ASCII characters. (Contributed by INADA Naoki in bpo-32677(4).) * *note ImportError: 334. now displays module name and module ‘__file__’ path when ‘from ... import ...’ fails. (Contributed by Matthias Bussonnier in bpo-29546(5).) * Circular imports involving absolute imports with binding a submodule to a name are now supported. (Contributed by Serhiy Storchaka in bpo-30024(6).) * ‘object.__format__(x, '')’ is now equivalent to ‘str(x)’ rather than ‘format(str(self), '')’. (Contributed by Serhiy Storchaka in bpo-28974(7).) * In order to better support dynamic creation of stack traces, *note types.TracebackType: 335. can now be instantiated from Python code, and the ‘tb_next’ attribute on *note tracebacks: 336. is now writable. (Contributed by Nathaniel J. Smith in bpo-30579(8).) * When using the *note -m: 337. switch, ‘sys.path[0]’ is now eagerly expanded to the full starting directory path, rather than being left as the empty directory (which allows imports from the `current' working directory at the time when an import occurs) (Contributed by Nick Coghlan in bpo-33053(9).) * The new *note -X: 155. ‘importtime’ option or the *note PYTHONPROFILEIMPORTTIME: 338. environment variable can be used to show the timing of each module import. (Contributed by Victor Stinner in bpo-31415(10).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12844 (2) https://bugs.python.org/issue18896 (3) https://bugs.python.org/issue28927 (4) https://bugs.python.org/issue32677 (5) https://bugs.python.org/issue29546 (6) https://bugs.python.org/issue30024 (7) https://bugs.python.org/issue28974 (8) https://bugs.python.org/issue30579 (9) https://bugs.python.org/issue33053 (10) https://bugs.python.org/issue31415  File: python.info, Node: New Modules<2>, Next: Improved Modules<2>, Prev: Other Language Changes<2>, Up: What’s New In Python 3 7 1.2.4 New Modules ----------------- * Menu: * contextvars:: * dataclasses:: * importlib.resources: importlib resources.  File: python.info, Node: contextvars, Next: dataclasses, Up: New Modules<2> 1.2.4.1 contextvars ................... The new *note contextvars: 25. module and a set of *note new C APIs: 33b. introduce support for `context variables'. Context variables are conceptually similar to thread-local variables. Unlike TLS, context variables support asynchronous code correctly. The *note asyncio: a. and *note decimal: 36. modules have been updated to use and support context variables out of the box. Particularly the active decimal context is now stored in a context variable, which allows decimal operations to work with the correct context in asynchronous code. See also ........ PEP 567(1) – Context Variables PEP written and implemented by Yury Selivanov ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0567  File: python.info, Node: dataclasses, Next: importlib resources, Prev: contextvars, Up: New Modules<2> 1.2.4.2 dataclasses ................... The new *note dataclass(): 33d. decorator provides a way to declare `data classes'. A data class describes its attributes using class variable annotations. Its constructor and other magic methods, such as *note __repr__(): 33e, *note __eq__(): 33f, and *note __hash__(): 340. are generated automatically. Example: @dataclass class Point: x: float y: float z: float = 0.0 p = Point(1.5, 2.5) print(p) # produces "Point(x=1.5, y=2.5, z=0.0)" See also ........ PEP 557(1) – Data Classes PEP written and implemented by Eric V. Smith ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0557  File: python.info, Node: importlib resources, Prev: dataclasses, Up: New Modules<2> 1.2.4.3 importlib.resources ........................... The new *note importlib.resources: 9e. module provides several new APIs and one new ABC for access to, opening, and reading `resources' inside packages. Resources are roughly similar to files inside packages, but they needn’t be actual files on the physical file system. Module loaders can provide a ‘get_resource_reader()’ function which returns a *note importlib.abc.ResourceReader: 342. instance to support this new API. Built-in file path loaders and zip file loaders both support this. Contributed by Barry Warsaw and Brett Cannon in bpo-32248(1). See also ........ importlib_resources(2) – a PyPI backport for earlier Python versions. ---------- Footnotes ---------- (1) https://bugs.python.org/issue32248 (2) http://importlib-resources.readthedocs.io/en/latest/  File: python.info, Node: Improved Modules<2>, Next: C API Changes, Prev: New Modules<2>, Up: What’s New In Python 3 7 1.2.5 Improved Modules ---------------------- * Menu: * argparse:: * asyncio: asyncio<2>. * binascii:: * calendar:: * collections: collections<2>. * compileall:: * concurrent.futures: concurrent futures. * contextlib:: * cProfile: cProfile<2>. * crypt:: * datetime: datetime<2>. * dbm:: * decimal:: * dis:: * distutils:: * enum:: * functools: functools<2>. * gc: gc<2>. * hmac:: * http.client: http client. * http.server: http server. * idlelib and IDLE:: * importlib:: * io: io<2>. * ipaddress:: * itertools: itertools<2>. * locale:: * logging: logging<2>. * math: math<2>. * mimetypes:: * msilib:: * multiprocessing: multiprocessing<2>. * os: os<2>. * pathlib: pathlib<2>. * pdb:: * py_compile: py_compile<2>. * pydoc:: * queue:: * re:: * signal:: * socket: socket<2>. * socketserver:: * sqlite3:: * ssl: ssl<2>. * string:: * subprocess:: * sys: sys<2>. * time: time<2>. * tkinter: tkinter<2>. * tracemalloc:: * types:: * unicodedata: unicodedata<2>. * unittest: unittest<2>. * unittest.mock: unittest mock. * urllib.parse: urllib parse. * uu:: * uuid:: * warnings:: * xml.etree: xml etree. * xmlrpc.server: xmlrpc server. * zipapp:: * zipfile::  File: python.info, Node: argparse, Next: asyncio<2>, Up: Improved Modules<2> 1.2.5.1 argparse ................ The new *note ArgumentParser.parse_intermixed_args(): 345. method allows intermixing options and positional arguments. (Contributed by paul.j3 in bpo-14191(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14191  File: python.info, Node: asyncio<2>, Next: binascii, Prev: argparse, Up: Improved Modules<2> 1.2.5.2 asyncio ............... The *note asyncio: a. module has received many new features, usability and *note performance improvements: 347. Notable changes include: * The new *note provisional: 348. *note asyncio.run(): 1a5. function can be used to run a coroutine from synchronous code by automatically creating and destroying the event loop. (Contributed by Yury Selivanov in bpo-32314(1).) * asyncio gained support for *note contextvars: 25. *note loop.call_soon(): 349, *note loop.call_soon_threadsafe(): 34a, *note loop.call_later(): 34b, *note loop.call_at(): 34c, and *note Future.add_done_callback(): 34d. have a new optional keyword-only `context' parameter. *note Tasks: 1ad. now track their context automatically. See PEP 567(2) for more details. (Contributed by Yury Selivanov in bpo-32436(3).) * The new *note asyncio.create_task(): 1ae. function has been added as a shortcut to ‘asyncio.get_event_loop().create_task()’. (Contributed by Andrew Svetlov in bpo-32311(4).) * The new *note loop.start_tls(): 34e. method can be used to upgrade an existing connection to TLS. (Contributed by Yury Selivanov in bpo-23749(5).) * The new *note loop.sock_recv_into(): 34f. method allows reading data from a socket directly into a provided buffer making it possible to reduce data copies. (Contributed by Antoine Pitrou in bpo-31819(6).) * The new *note asyncio.current_task(): 350. function returns the currently running *note Task: 1ad. instance, and the new *note asyncio.all_tasks(): 351. function returns a set of all existing ‘Task’ instances in a given loop. The *note Task.current_task(): 352. and *note Task.all_tasks(): 353. methods have been deprecated. (Contributed by Andrew Svetlov in bpo-32250(7).) * The new `provisional' *note BufferedProtocol: 2c9. class allows implementing streaming protocols with manual control over the receive buffer. (Contributed by Yury Selivanov in bpo-32251(8).) * The new *note asyncio.get_running_loop(): 354. function returns the currently running loop, and raises a *note RuntimeError: 2ba. if no loop is running. This is in contrast with *note asyncio.get_event_loop(): 355, which will `create' a new event loop if none is running. (Contributed by Yury Selivanov in bpo-32269(9).) * The new *note StreamWriter.wait_closed(): 356. coroutine method allows waiting until the stream writer is closed. The new *note StreamWriter.is_closing(): 357. method can be used to determine if the writer is closing. (Contributed by Andrew Svetlov in bpo-32391(10).) * The new *note loop.sock_sendfile(): 358. coroutine method allows sending files using *note os.sendfile: 359. when possible. (Contributed by Andrew Svetlov in bpo-32410(11).) * The new *note Future.get_loop(): 35a. and ‘Task.get_loop()’ methods return the instance of the loop on which a task or a future were created. *note Server.get_loop(): 35b. allows doing the same for *note asyncio.Server: 35c. objects. (Contributed by Yury Selivanov in bpo-32415(12) and Srinivas Reddy Thatiparthy in bpo-32418(13).) * It is now possible to control how instances of *note asyncio.Server: 35c. begin serving. Previously, the server would start serving immediately when created. The new `start_serving' keyword argument to *note loop.create_server(): 35d. and *note loop.create_unix_server(): 35e, as well as *note Server.start_serving(): 35f, and *note Server.serve_forever(): 360. can be used to decouple server instantiation and serving. The new *note Server.is_serving(): 361. method returns ‘True’ if the server is serving. *note Server: 35c. objects are now asynchronous context managers: srv = await loop.create_server(...) async with srv: # some code # At this point, srv is closed and no longer accepts new connections. (Contributed by Yury Selivanov in bpo-32662(14).) * Callback objects returned by *note loop.call_later(): 34b. gained the new *note when(): 362. method which returns an absolute scheduled callback timestamp. (Contributed by Andrew Svetlov in bpo-32741(15).) * The *note loop.create_datagram_endpoint(): 2e7. method gained support for Unix sockets. (Contributed by Quentin Dawans in bpo-31245(16).) * The *note asyncio.open_connection(): 363, *note asyncio.start_server(): 364. functions, *note loop.create_connection(): 1b2, *note loop.create_server(): 35d, *note loop.create_accepted_socket(): 365. methods and their corresponding UNIX socket variants now accept the `ssl_handshake_timeout' keyword argument. (Contributed by Neil Aspinall in bpo-29970(17).) * The new *note Handle.cancelled(): 366. method returns ‘True’ if the callback was cancelled. (Contributed by Marat Sharafutdinov in bpo-31943(18).) * The asyncio source has been converted to use the *note async: 1a2./*note await: 1a3. syntax. (Contributed by Andrew Svetlov in bpo-32193(19).) * The new *note ReadTransport.is_reading(): 367. method can be used to determine the reading state of the transport. Additionally, calls to *note ReadTransport.resume_reading(): 368. and *note ReadTransport.pause_reading(): 369. are now idempotent. (Contributed by Yury Selivanov in bpo-32356(20).) * Loop methods which accept socket paths now support passing *note path-like objects: 36a. (Contributed by Yury Selivanov in bpo-32066(21).) * In *note asyncio: a. TCP sockets on Linux are now created with ‘TCP_NODELAY’ flag set by default. (Contributed by Yury Selivanov and Victor Stinner in bpo-27456(22).) * Exceptions occurring in cancelled tasks are no longer logged. (Contributed by Yury Selivanov in bpo-30508(23).) * New ‘WindowsSelectorEventLoopPolicy’ and ‘WindowsProactorEventLoopPolicy’ classes. (Contributed by Yury Selivanov in bpo-33792(24).) Several ‘asyncio’ APIs have been *note deprecated: 36b. ---------- Footnotes ---------- (1) https://bugs.python.org/issue32314 (2) https://www.python.org/dev/peps/pep-0567 (3) https://bugs.python.org/issue32436 (4) https://bugs.python.org/issue32311 (5) https://bugs.python.org/issue23749 (6) https://bugs.python.org/issue31819 (7) https://bugs.python.org/issue32250 (8) https://bugs.python.org/issue32251 (9) https://bugs.python.org/issue32269 (10) https://bugs.python.org/issue32391 (11) https://bugs.python.org/issue32410 (12) https://bugs.python.org/issue32415 (13) https://bugs.python.org/issue32418 (14) https://bugs.python.org/issue32662 (15) https://bugs.python.org/issue32741 (16) https://bugs.python.org/issue31245 (17) https://bugs.python.org/issue29970 (18) https://bugs.python.org/issue31943 (19) https://bugs.python.org/issue32193 (20) https://bugs.python.org/issue32356 (21) https://bugs.python.org/issue32066 (22) https://bugs.python.org/issue27456 (23) https://bugs.python.org/issue30508 (24) https://bugs.python.org/issue33792  File: python.info, Node: binascii, Next: calendar, Prev: asyncio<2>, Up: Improved Modules<2> 1.2.5.3 binascii ................ The *note b2a_uu(): 36d. function now accepts an optional `backtick' keyword argument. When it’s true, zeros are represented by ‘'`'’ instead of spaces. (Contributed by Xiang Zhang in bpo-30103(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30103  File: python.info, Node: calendar, Next: collections<2>, Prev: binascii, Up: Improved Modules<2> 1.2.5.4 calendar ................ The *note HTMLCalendar: 36f. class has new class attributes which ease the customization of CSS classes in the produced HTML calendar. (Contributed by Oz Tiram in bpo-30095(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30095  File: python.info, Node: collections<2>, Next: compileall, Prev: calendar, Up: Improved Modules<2> 1.2.5.5 collections ................... ‘collections.namedtuple()’ now supports default values. (Contributed by Raymond Hettinger in bpo-32320(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32320  File: python.info, Node: compileall, Next: concurrent futures, Prev: collections<2>, Up: Improved Modules<2> 1.2.5.6 compileall .................. *note compileall.compile_dir(): 372. learned the new `invalidation_mode' parameter, which can be used to enable *note hash-based .pyc invalidation: 301. The invalidation mode can also be specified on the command line using the new ‘--invalidation-mode’ argument. (Contributed by Benjamin Peterson in bpo-31650(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31650  File: python.info, Node: concurrent futures, Next: contextlib, Prev: compileall, Up: Improved Modules<2> 1.2.5.7 concurrent.futures .......................... *note ProcessPoolExecutor: 2a4. and *note ThreadPoolExecutor: 27a. now support the new `initializer' and `initargs' constructor arguments. (Contributed by Antoine Pitrou in bpo-21423(1).) The *note ProcessPoolExecutor: 2a4. can now take the multiprocessing context via the new `mp_context' argument. (Contributed by Thomas Moreau in bpo-31540(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21423 (2) https://bugs.python.org/issue31540  File: python.info, Node: contextlib, Next: cProfile<2>, Prev: concurrent futures, Up: Improved Modules<2> 1.2.5.8 contextlib .................. The new *note nullcontext(): 375. is a simpler and faster no-op context manager than *note ExitStack: 376. (Contributed by Jesse-Bakker in bpo-10049(1).) The new *note asynccontextmanager(): 377, *note AbstractAsyncContextManager: 378, and *note AsyncExitStack: 379. have been added to complement their synchronous counterparts. (Contributed by Jelle Zijlstra in bpo-29679(2) and bpo-30241(3), and by Alexander Mohr and Ilya Kulakov in bpo-29302(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10049 (2) https://bugs.python.org/issue29679 (3) https://bugs.python.org/issue30241 (4) https://bugs.python.org/issue29302  File: python.info, Node: cProfile<2>, Next: crypt, Prev: contextlib, Up: Improved Modules<2> 1.2.5.9 cProfile ................ The *note cProfile: 28. command line now accepts ‘-m module_name’ as an alternative to script path. (Contributed by Sanyam Khurana in bpo-21862(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21862  File: python.info, Node: crypt, Next: datetime<2>, Prev: cProfile<2>, Up: Improved Modules<2> 1.2.5.10 crypt .............. The *note crypt: 29. module now supports the Blowfish hashing method. (Contributed by Serhiy Storchaka in bpo-31664(1).) The *note mksalt(): 37c. function now allows specifying the number of rounds for hashing. (Contributed by Serhiy Storchaka in bpo-31702(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31664 (2) https://bugs.python.org/issue31702  File: python.info, Node: datetime<2>, Next: dbm, Prev: crypt, Up: Improved Modules<2> 1.2.5.11 datetime ................. The new *note datetime.fromisoformat(): 37e. method constructs a *note datetime: 194. object from a string in one of the formats output by *note datetime.isoformat(): 37f. (Contributed by Paul Ganssle in bpo-15873(1).) The *note tzinfo: 380. class now supports sub-minute offsets. (Contributed by Alexander Belopolsky in bpo-5288(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15873 (2) https://bugs.python.org/issue5288  File: python.info, Node: dbm, Next: decimal, Prev: datetime<2>, Up: Improved Modules<2> 1.2.5.12 dbm ............ *note dbm.dumb: 33. now supports reading read-only files and no longer writes the index file when it is not changed.  File: python.info, Node: decimal, Next: dis, Prev: dbm, Up: Improved Modules<2> 1.2.5.13 decimal ................ The *note decimal: 36. module now uses *note context variables: 2f5. to store the decimal context. (Contributed by Yury Selivanov in bpo-32630(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32630  File: python.info, Node: dis, Next: distutils, Prev: decimal, Up: Improved Modules<2> 1.2.5.14 dis ............ The *note dis(): 384. function is now able to disassemble nested code objects (the code of comprehensions, generator expressions and nested functions, and the code used for building nested classes). The maximum depth of disassembly recursion is controlled by the new `depth' parameter. (Contributed by Serhiy Storchaka in bpo-11822(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11822  File: python.info, Node: distutils, Next: enum, Prev: dis, Up: Improved Modules<2> 1.2.5.15 distutils .................. ‘README.rst’ is now included in the list of distutils standard READMEs and therefore included in source distributions. (Contributed by Ryan Gonzalez in bpo-11913(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11913  File: python.info, Node: enum, Next: functools<2>, Prev: distutils, Up: Improved Modules<2> 1.2.5.16 enum ............. The *note Enum: 387. learned the new ‘_ignore_’ class property, which allows listing the names of properties which should not become enum members. (Contributed by Ethan Furman in bpo-31801(1).) In Python 3.8, attempting to check for non-Enum objects in ‘Enum’ classes will raise a *note TypeError: 192. (e.g. ‘1 in Color’); similarly, attempting to check for non-Flag objects in a ‘Flag’ member will raise *note TypeError: 192. (e.g. ‘1 in Perm.RW’); currently, both operations return *note False: 388. instead and are deprecated. (Contributed by Ethan Furman in bpo-33217(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31801 (2) https://bugs.python.org/issue33217  File: python.info, Node: functools<2>, Next: gc<2>, Prev: enum, Up: Improved Modules<2> 1.2.5.17 functools .................. *note functools.singledispatch(): 38a. now supports registering implementations using type annotations. (Contributed by Łukasz Langa in bpo-32227(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32227  File: python.info, Node: gc<2>, Next: hmac, Prev: functools<2>, Up: Improved Modules<2> 1.2.5.18 gc ........... The new *note gc.freeze(): 38c. function allows freezing all objects tracked by the garbage collector and excluding them from future collections. This can be used before a POSIX ‘fork()’ call to make the GC copy-on-write friendly or to speed up collection. The new *note gc.unfreeze(): 38d. functions reverses this operation. Additionally, *note gc.get_freeze_count(): 38e. can be used to obtain the number of frozen objects. (Contributed by Li Zekun in bpo-31558(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31558  File: python.info, Node: hmac, Next: http client, Prev: gc<2>, Up: Improved Modules<2> 1.2.5.19 hmac ............. The *note hmac: 8f. module now has an optimized one-shot *note digest(): 390. function, which is up to three times faster than ‘HMAC()’. (Contributed by Christian Heimes in bpo-32433(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32433  File: python.info, Node: http client, Next: http server, Prev: hmac, Up: Improved Modules<2> 1.2.5.20 http.client .................... *note HTTPConnection: 392. and *note HTTPSConnection: 393. now support the new `blocksize' argument for improved upload throughput. (Contributed by Nir Soffer in bpo-31945(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31945  File: python.info, Node: http server, Next: idlelib and IDLE, Prev: http client, Up: Improved Modules<2> 1.2.5.21 http.server .................... *note SimpleHTTPRequestHandler: 395. now supports the HTTP ‘If-Modified-Since’ header. The server returns the 304 response status if the target file was not modified after the time specified in the header. (Contributed by Pierre Quentel in bpo-29654(1).) *note SimpleHTTPRequestHandler: 395. accepts the new `directory' argument, in addition to the new ‘--directory’ command line argument. With this parameter, the server serves the specified directory, by default it uses the current working directory. (Contributed by Stéphane Wirtel and Julien Palard in bpo-28707(2).) The new *note ThreadingHTTPServer: 396. class uses threads to handle requests using ‘ThreadingMixin’. It is used when ‘http.server’ is run with ‘-m’. (Contributed by Julien Palard in bpo-31639(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29654 (2) https://bugs.python.org/issue28707 (3) https://bugs.python.org/issue31639  File: python.info, Node: idlelib and IDLE, Next: importlib, Prev: http server, Up: Improved Modules<2> 1.2.5.22 idlelib and IDLE ......................... Multiple fixes for autocompletion. (Contributed by Louie Lu in bpo-15786(1).) Module Browser (on the File menu, formerly called Class Browser), now displays nested functions and classes in addition to top-level functions and classes. (Contributed by Guilherme Polo, Cheryl Sabella, and Terry Jan Reedy in bpo-1612262(2).) The Settings dialog (Options, Configure IDLE) has been partly rewritten to improve both appearance and function. (Contributed by Cheryl Sabella and Terry Jan Reedy in multiple issues.) The font sample now includes a selection of non-Latin characters so that users can better see the effect of selecting a particular font. (Contributed by Terry Jan Reedy in bpo-13802(3).) The sample can be edited to include other characters. (Contributed by Serhiy Storchaka in bpo-31860(4).) The IDLE features formerly implemented as extensions have been reimplemented as normal features. Their settings have been moved from the Extensions tab to other dialog tabs. (Contributed by Charles Wohlganger and Terry Jan Reedy in bpo-27099(5).) Editor code context option revised. Box displays all context lines up to maxlines. Clicking on a context line jumps the editor to that line. Context colors for custom themes is added to Highlights tab of Settings dialog. (Contributed by Cheryl Sabella and Terry Jan Reedy in bpo-33642(6), bpo-33768(7), and bpo-33679(8).) On Windows, a new API call tells Windows that tk scales for DPI. On Windows 8.1+ or 10, with DPI compatibility properties of the Python binary unchanged, and a monitor resolution greater than 96 DPI, this should make text and lines sharper. It should otherwise have no effect. (Contributed by Terry Jan Reedy in bpo-33656(9).) New in 3.7.1: Output over N lines (50 by default) is squeezed down to a button. N can be changed in the PyShell section of the General page of the Settings dialog. Fewer, but possibly extra long, lines can be squeezed by right clicking on the output. Squeezed output can be expanded in place by double-clicking the button or into the clipboard or a separate window by right-clicking the button. (Contributed by Tal Einat in bpo-1529353(10).) The changes above have been backported to 3.6 maintenance releases. NEW in 3.7.4: Add “Run Customized” to the Run menu to run a module with customized settings. Any command line arguments entered are added to sys.argv. They re-appear in the box for the next customized run. One can also suppress the normal Shell main module restart. (Contributed by Cheryl Sabella, Terry Jan Reedy, and others in bpo-5680(11) and bpo-37627(12).) New in 3.7.5: Add optional line numbers for IDLE editor windows. Windows open without line numbers unless set otherwise in the General tab of the configuration dialog. Line numbers for an existing window are shown and hidden in the Options menu. (Contributed by Tal Einat and Saimadhav Heblikar in bpo-17535(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15786 (2) https://bugs.python.org/issue1612262 (3) https://bugs.python.org/issue13802 (4) https://bugs.python.org/issue31860 (5) https://bugs.python.org/issue27099 (6) https://bugs.python.org/issue33642 (7) https://bugs.python.org/issue33768 (8) https://bugs.python.org/issue33679 (9) https://bugs.python.org/issue33656 (10) https://bugs.python.org/issue1529353 (11) https://bugs.python.org/issue5680 (12) https://bugs.python.org/issue37627 (13) https://bugs.python.org/issue17535  File: python.info, Node: importlib, Next: io<2>, Prev: idlelib and IDLE, Up: Improved Modules<2> 1.2.5.23 importlib .................. The *note importlib.abc.ResourceReader: 342. ABC was introduced to support the loading of resources from packages. See also *note importlib.resources: 2f7. (Contributed by Barry Warsaw, Brett Cannon in bpo-32248(1).) *note importlib.reload(): 399. now raises *note ModuleNotFoundError: 39a. if the module lacks a spec. (Contributed by Garvit Khatri in bpo-29851(2).) ‘importlib.find_spec()’ now raises *note ModuleNotFoundError: 39a. instead of *note AttributeError: 39b. if the specified parent module is not a package (i.e. lacks a ‘__path__’ attribute). (Contributed by Milan Oberkirch in bpo-30436(3).) The new ‘importlib.source_hash()’ can be used to compute the hash of the passed source. A *note hash-based .pyc file: 301. embeds the value returned by this function. ---------- Footnotes ---------- (1) https://bugs.python.org/issue32248 (2) https://bugs.python.org/issue29851 (3) https://bugs.python.org/issue30436  File: python.info, Node: io<2>, Next: ipaddress, Prev: importlib, Up: Improved Modules<2> 1.2.5.24 io ........... The new *note TextIOWrapper.reconfigure(): 39d. method can be used to reconfigure the text stream with the new settings. (Contributed by Antoine Pitrou in bpo-30526(1) and INADA Naoki in bpo-15216(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30526 (2) https://bugs.python.org/issue15216  File: python.info, Node: ipaddress, Next: itertools<2>, Prev: io<2>, Up: Improved Modules<2> 1.2.5.25 ipaddress .................. The new ‘subnet_of()’ and ‘supernet_of()’ methods of *note ipaddress.IPv6Network: 39f. and *note ipaddress.IPv4Network: 3a0. can be used for network containment tests. (Contributed by Michel Albert and Cheryl Sabella in bpo-20825(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20825  File: python.info, Node: itertools<2>, Next: locale, Prev: ipaddress, Up: Improved Modules<2> 1.2.5.26 itertools .................. *note itertools.islice(): 3a2. now accepts *note integer-like objects: 18a. as start, stop, and slice arguments. (Contributed by Will Roberts in bpo-30537(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30537  File: python.info, Node: locale, Next: logging<2>, Prev: itertools<2>, Up: Improved Modules<2> 1.2.5.27 locale ............... The new `monetary' argument to *note locale.format_string(): 3a4. can be used to make the conversion use monetary thousands separators and grouping strings. (Contributed by Garvit in bpo-10379(1).) The *note locale.getpreferredencoding(): 3a5. function now always returns ‘'UTF-8'’ on Android or when in the *note forced UTF-8 mode: 300. ---------- Footnotes ---------- (1) https://bugs.python.org/issue10379  File: python.info, Node: logging<2>, Next: math<2>, Prev: locale, Up: Improved Modules<2> 1.2.5.28 logging ................ *note Logger: 3a7. instances can now be pickled. (Contributed by Vinay Sajip in bpo-30520(1).) The new *note StreamHandler.setStream(): 3a8. method can be used to replace the logger stream after handler creation. (Contributed by Vinay Sajip in bpo-30522(2).) It is now possible to specify keyword arguments to handler constructors in configuration passed to *note logging.config.fileConfig(): 3a9. (Contributed by Preston Landers in bpo-31080(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30520 (2) https://bugs.python.org/issue30522 (3) https://bugs.python.org/issue31080  File: python.info, Node: math<2>, Next: mimetypes, Prev: logging<2>, Up: Improved Modules<2> 1.2.5.29 math ............. The new *note math.remainder(): 3ab. function implements the IEEE 754-style remainder operation. (Contributed by Mark Dickinson in bpo-29962(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29962  File: python.info, Node: mimetypes, Next: msilib, Prev: math<2>, Up: Improved Modules<2> 1.2.5.30 mimetypes .................. The MIME type of .bmp has been changed from ‘'image/x-ms-bmp'’ to ‘'image/bmp'’. (Contributed by Nitish Chandra in bpo-22589(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22589  File: python.info, Node: msilib, Next: multiprocessing<2>, Prev: mimetypes, Up: Improved Modules<2> 1.2.5.31 msilib ............... The new *note Database.Close(): 3ae. method can be used to close the MSI (last-in, first-out) database. (Contributed by Berker Peksag in bpo-20486(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20486  File: python.info, Node: multiprocessing<2>, Next: os<2>, Prev: msilib, Up: Improved Modules<2> 1.2.5.32 multiprocessing ........................ The new *note Process.close(): 3b0. method explicitly closes the process object and releases all resources associated with it. *note ValueError: 1fb. is raised if the underlying process is still running. (Contributed by Antoine Pitrou in bpo-30596(1).) The new *note Process.kill(): 3b1. method can be used to terminate the process using the ‘SIGKILL’ signal on Unix. (Contributed by Vitor Pereira in bpo-30794(2).) Non-daemonic threads created by *note Process: 3b2. are now joined on process exit. (Contributed by Antoine Pitrou in bpo-18966(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30596 (2) https://bugs.python.org/issue30794 (3) https://bugs.python.org/issue18966  File: python.info, Node: os<2>, Next: pathlib<2>, Prev: multiprocessing<2>, Up: Improved Modules<2> 1.2.5.33 os ........... *note os.fwalk(): 3b4. now accepts the `path' argument as *note bytes: 331. (Contributed by Serhiy Storchaka in bpo-28682(1).) *note os.scandir(): 25f. gained support for *note file descriptors: 3b5. (Contributed by Serhiy Storchaka in bpo-25996(2).) The new *note register_at_fork(): 3b6. function allows registering Python callbacks to be executed at process fork. (Contributed by Antoine Pitrou in bpo-16500(3).) Added *note os.preadv(): 3b7. (combine the functionality of *note os.readv(): 3b8. and *note os.pread(): 3b9.) and *note os.pwritev(): 3ba. functions (combine the functionality of *note os.writev(): 3bb. and *note os.pwrite(): 3bc.). (Contributed by Pablo Galindo in bpo-31368(4).) The mode argument of *note os.makedirs(): 3bd. no longer affects the file permission bits of newly-created intermediate-level directories. (Contributed by Serhiy Storchaka in bpo-19930(5).) *note os.dup2(): 3be. now returns the new file descriptor. Previously, ‘None’ was always returned. (Contributed by Benjamin Peterson in bpo-32441(6).) The structure returned by *note os.stat(): 1f1. now contains the *note st_fstype: 3bf. attribute on Solaris and its derivatives. (Contributed by Jesús Cea Avión in bpo-32659(7).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28682 (2) https://bugs.python.org/issue25996 (3) https://bugs.python.org/issue16500 (4) https://bugs.python.org/issue31368 (5) https://bugs.python.org/issue19930 (6) https://bugs.python.org/issue32441 (7) https://bugs.python.org/issue32659  File: python.info, Node: pathlib<2>, Next: pdb, Prev: os<2>, Up: Improved Modules<2> 1.2.5.34 pathlib ................ The new *note Path.is_mount(): 205. method is now available on POSIX systems and can be used to determine whether a path is a mount point. (Contributed by Cooper Ry Lees in bpo-30897(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30897  File: python.info, Node: pdb, Next: py_compile<2>, Prev: pathlib<2>, Up: Improved Modules<2> 1.2.5.35 pdb ............ *note pdb.set_trace(): 3c2. now takes an optional `header' keyword-only argument. If given, it is printed to the console just before debugging begins. (Contributed by Barry Warsaw in bpo-31389(1).) *note pdb: c9. command line now accepts ‘-m module_name’ as an alternative to script file. (Contributed by Mario Corchero in bpo-32206(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31389 (2) https://bugs.python.org/issue32206  File: python.info, Node: py_compile<2>, Next: pydoc, Prev: pdb, Up: Improved Modules<2> 1.2.5.36 py_compile ................... *note py_compile.compile(): 215. – and by extension, *note compileall: 21. – now respects the ‘SOURCE_DATE_EPOCH’ environment variable by unconditionally creating ‘.pyc’ files for hash-based validation. This allows for guaranteeing reproducible builds(1) of ‘.pyc’ files when they are created eagerly. (Contributed by Bernhard M. Wiedemann in bpo-29708(2).) ---------- Footnotes ---------- (1) https://reproducible-builds.org/ (2) https://bugs.python.org/issue29708  File: python.info, Node: pydoc, Next: queue, Prev: py_compile<2>, Up: Improved Modules<2> 1.2.5.37 pydoc .............. The pydoc server can now bind to an arbitrary hostname specified by the new ‘-n’ command-line argument. (Contributed by Feanil Patel in bpo-31128(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31128  File: python.info, Node: queue, Next: re, Prev: pydoc, Up: Improved Modules<2> 1.2.5.38 queue .............. The new *note SimpleQueue: 3c6. class is an unbounded FIFO (last-in, first-out) queue. (Contributed by Antoine Pitrou in bpo-14976(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14976  File: python.info, Node: re, Next: signal, Prev: queue, Up: Improved Modules<2> 1.2.5.39 re ........... The flags *note re.ASCII: 3c8, *note re.LOCALE: 3c9. and ‘re.UNICODE’ can be set within the scope of a group. (Contributed by Serhiy Storchaka in bpo-31690(1).) *note re.split(): 3ca. now supports splitting on a pattern like ‘r'\b'’, ‘'^$'’ or ‘(?=-)’ that matches an empty string. (Contributed by Serhiy Storchaka in bpo-25054(2).) Regular expressions compiled with the *note re.LOCALE: 3c9. flag no longer depend on the locale at compile time. Locale settings are applied only when the compiled regular expression is used. (Contributed by Serhiy Storchaka in bpo-30215(3).) *note FutureWarning: 325. is now emitted if a regular expression contains character set constructs that will change semantically in the future, such as nested sets and set operations. (Contributed by Serhiy Storchaka in bpo-30349(4).) Compiled regular expression and match objects can now be copied using *note copy.copy(): 3cb. and *note copy.deepcopy(): 3cc. (Contributed by Serhiy Storchaka in bpo-10076(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31690 (2) https://bugs.python.org/issue25054 (3) https://bugs.python.org/issue30215 (4) https://bugs.python.org/issue30349 (5) https://bugs.python.org/issue10076  File: python.info, Node: signal, Next: socket<2>, Prev: re, Up: Improved Modules<2> 1.2.5.40 signal ............... The new `warn_on_full_buffer' argument to the *note signal.set_wakeup_fd(): 3ce. function makes it possible to specify whether Python prints a warning on stderr when the wakeup buffer overflows. (Contributed by Nathaniel J. Smith in bpo-30050(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30050  File: python.info, Node: socket<2>, Next: socketserver, Prev: signal, Up: Improved Modules<2> 1.2.5.41 socket ............... The new *note socket.getblocking(): 3d0. method returns ‘True’ if the socket is in blocking mode and ‘False’ otherwise. (Contributed by Yury Selivanov in bpo-32373(1).) The new *note socket.close(): 3d1. function closes the passed socket file descriptor. This function should be used instead of *note os.close(): 3d2. for better compatibility across platforms. (Contributed by Christian Heimes in bpo-32454(2).) The *note socket: ef. module now exposes the ‘socket.TCP_CONGESTION’ (Linux 2.6.13), ‘socket.TCP_USER_TIMEOUT’ (Linux 2.6.37), and ‘socket.TCP_NOTSENT_LOWAT’ (Linux 3.12) constants. (Contributed by Omar Sandoval in bpo-26273(3) and Nathaniel J. Smith in bpo-29728(4).) Support for *note socket.AF_VSOCK: 3d3. sockets has been added to allow communication between virtual machines and their hosts. (Contributed by Cathy Avery in bpo-27584(5).) Sockets now auto-detect family, type and protocol from file descriptor by default. (Contributed by Christian Heimes in bpo-28134(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32373 (2) https://bugs.python.org/issue32454 (3) https://bugs.python.org/issue26273 (4) https://bugs.python.org/issue29728 (5) https://bugs.python.org/issue27584 (6) https://bugs.python.org/issue28134  File: python.info, Node: socketserver, Next: sqlite3, Prev: socket<2>, Up: Improved Modules<2> 1.2.5.42 socketserver ..................... ‘socketserver.ThreadingMixIn.server_close()’ now waits until all non-daemon threads complete. ‘socketserver.ForkingMixIn.server_close()’ now waits until all child processes complete. Add a new ‘socketserver.ForkingMixIn.block_on_close’ class attribute to *note socketserver.ForkingMixIn: 3d5. and *note socketserver.ThreadingMixIn: 3d6. classes. Set the class attribute to ‘False’ to get the pre-3.7 behaviour.  File: python.info, Node: sqlite3, Next: ssl<2>, Prev: socketserver, Up: Improved Modules<2> 1.2.5.43 sqlite3 ................ *note sqlite3.Connection: 3d8. now exposes the *note backup(): 3d9. method when the underlying SQLite library is at version 3.6.11 or higher. (Contributed by Lele Gaifax in bpo-27645(1).) The `database' argument of *note sqlite3.connect(): 3da. now accepts any *note path-like object: 36a, instead of just a string. (Contributed by Anders Lorentsen in bpo-31843(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27645 (2) https://bugs.python.org/issue31843  File: python.info, Node: ssl<2>, Next: string, Prev: sqlite3, Up: Improved Modules<2> 1.2.5.44 ssl ............ The *note ssl: f3. module now uses OpenSSL’s builtin API instead of *note match_hostname(): 3dc. to check a host name or an IP address. Values are validated during TLS handshake. Any certificate validation error including failing the host name check now raises *note SSLCertVerificationError: 3dd. and aborts the handshake with a proper TLS Alert message. The new exception contains additional information. Host name validation can be customized with *note SSLContext.hostname_checks_common_name: 3de. (Contributed by Christian Heimes in bpo-31399(1).) Note: The improved host name check requires a `libssl' implementation compatible with OpenSSL 1.0.2 or 1.1. Consequently, OpenSSL 0.9.8 and 1.0.1 are no longer supported (see *note Platform Support Removals: 3df. for more details). The ssl module is mostly compatible with LibreSSL 2.7.2 and newer. The ‘ssl’ module no longer sends IP addresses in SNI TLS extension. (Contributed by Christian Heimes in bpo-32185(2).) *note match_hostname(): 3dc. no longer supports partial wildcards like ‘www*.example.org’. (Contributed by Mandeep Singh in bpo-23033(3) and Christian Heimes in bpo-31399(4).) The default cipher suite selection of the ‘ssl’ module now uses a blacklist approach rather than a hard-coded whitelist. Python no longer re-enables ciphers that have been blocked by OpenSSL security updates. Default cipher suite selection can be configured at compile time. (Contributed by Christian Heimes in bpo-31429(5).) Validation of server certificates containing internationalized domain names (IDNs) is now supported. As part of this change, the *note SSLSocket.server_hostname: 3e0. attribute now stores the expected hostname in A-label form (‘"xn--pythn-mua.org"’), rather than the U-label form (‘"pythön.org"’). (Contributed by Nathaniel J. Smith and Christian Heimes in bpo-28414(6).) The ‘ssl’ module has preliminary and experimental support for TLS 1.3 and OpenSSL 1.1.1. At the time of Python 3.7.0 release, OpenSSL 1.1.1 is still under development and TLS 1.3 hasn’t been finalized yet. The TLS 1.3 handshake and protocol behaves slightly differently than TLS 1.2 and earlier, see *note TLS 1.3: 3e1. (Contributed by Christian Heimes in bpo-32947(7), bpo-20995(8), bpo-29136(9), bpo-30622(10) and bpo-33618(11)) *note SSLSocket: 3e2. and *note SSLObject: 3e3. no longer have a public constructor. Direct instantiation was never a documented and supported feature. Instances must be created with *note SSLContext: 3e4. methods *note wrap_socket(): 3e5. and *note wrap_bio(): 3e6. (Contributed by Christian Heimes in bpo-32951(12)) OpenSSL 1.1 APIs for setting the minimum and maximum TLS protocol version are available as *note SSLContext.minimum_version: 3e7. and *note SSLContext.maximum_version: 3e8. Supported protocols are indicated by several new flags, such as *note HAS_TLSv1_1: 3e9. (Contributed by Christian Heimes in bpo-32609(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31399 (2) https://bugs.python.org/issue32185 (3) https://bugs.python.org/issue23033 (4) https://bugs.python.org/issue31399 (5) https://bugs.python.org/issue31429 (6) https://bugs.python.org/issue28414 (7) https://bugs.python.org/issue32947 (8) https://bugs.python.org/issue20995 (9) https://bugs.python.org/issue29136 (10) https://bugs.python.org/issue30622 (11) https://bugs.python.org/issue33618 (12) https://bugs.python.org/issue32951 (13) https://bugs.python.org/issue32609  File: python.info, Node: string, Next: subprocess, Prev: ssl<2>, Up: Improved Modules<2> 1.2.5.45 string ............... *note string.Template: 3eb. now lets you to optionally modify the regular expression pattern for braced placeholders and non-braced placeholders separately. (Contributed by Barry Warsaw in bpo-1198569(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1198569  File: python.info, Node: subprocess, Next: sys<2>, Prev: string, Up: Improved Modules<2> 1.2.5.46 subprocess ................... The *note subprocess.run(): 3ed. function accepts the new `capture_output' keyword argument. When true, stdout and stderr will be captured. This is equivalent to passing *note subprocess.PIPE: 3ee. as `stdout' and `stderr' arguments. (Contributed by Bo Bayles in bpo-32102(1).) The ‘subprocess.run’ function and the *note subprocess.Popen: 2b9. constructor now accept the `text' keyword argument as an alias to `universal_newlines'. (Contributed by Andrew Clegg in bpo-31756(2).) On Windows the default for `close_fds' was changed from ‘False’ to ‘True’ when redirecting the standard handles. It’s now possible to set `close_fds' to true when redirecting the standard handles. See *note subprocess.Popen: 2b9. This means that `close_fds' now defaults to ‘True’ on all supported platforms. (Contributed by Segev Finer in bpo-19764(3).) The subprocess module is now more graceful when handling *note KeyboardInterrupt: 197. during *note subprocess.call(): 3ef, *note subprocess.run(): 3ed, or in a *note Popen: 2b9. context manager. It now waits a short amount of time for the child to exit, before continuing the handling of the ‘KeyboardInterrupt’ exception. (Contributed by Gregory P. Smith in bpo-25942(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32102 (2) https://bugs.python.org/issue31756 (3) https://bugs.python.org/issue19764 (4) https://bugs.python.org/issue25942  File: python.info, Node: sys<2>, Next: time<2>, Prev: subprocess, Up: Improved Modules<2> 1.2.5.47 sys ............ The new *note sys.breakpointhook(): 313. hook function is called by the built-in *note breakpoint(): 2f9. (Contributed by Barry Warsaw in bpo-31353(1).) On Android, the new *note sys.getandroidapilevel(): 3f1. returns the build-time Android API version. (Contributed by Victor Stinner in bpo-28740(2).) The new *note sys.get_coroutine_origin_tracking_depth(): 3f2. function returns the current coroutine origin tracking depth, as set by the new *note sys.set_coroutine_origin_tracking_depth(): 3f3. *note asyncio: a. has been converted to use this new API instead of the deprecated ‘sys.set_coroutine_wrapper()’. (Contributed by Nathaniel J. Smith in bpo-32591(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31353 (2) https://bugs.python.org/issue28740 (3) https://bugs.python.org/issue32591  File: python.info, Node: time<2>, Next: tkinter<2>, Prev: sys<2>, Up: Improved Modules<2> 1.2.5.48 time ............. PEP 564(1) adds six new functions with nanosecond resolution to the *note time: 10a. module: * *note time.clock_gettime_ns(): 31e. * *note time.clock_settime_ns(): 31f. * *note time.monotonic_ns(): 320. * *note time.perf_counter_ns(): 321. * *note time.process_time_ns(): 322. * *note time.time_ns(): 323. New clock identifiers have been added: * *note time.CLOCK_BOOTTIME: 3f5. (Linux): Identical to *note time.CLOCK_MONOTONIC: 3f6, except it also includes any time that the system is suspended. * *note time.CLOCK_PROF: 3f7. (FreeBSD, NetBSD and OpenBSD): High-resolution per-process CPU timer. * *note time.CLOCK_UPTIME: 3f8. (FreeBSD, OpenBSD): Time whose absolute value is the time the system has been running and not suspended, providing accurate uptime measurement. The new *note time.thread_time(): 3f9. and *note time.thread_time_ns(): 3fa. functions can be used to get per-thread CPU time measurements. (Contributed by Antoine Pitrou in bpo-32025(2).) The new *note time.pthread_getcpuclockid(): 3fb. function returns the clock ID of the thread-specific CPU-time clock. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0564 (2) https://bugs.python.org/issue32025  File: python.info, Node: tkinter<2>, Next: tracemalloc, Prev: time<2>, Up: Improved Modules<2> 1.2.5.49 tkinter ................ The new *note tkinter.ttk.Spinbox: 3fd. class is now available. (Contributed by Alan Moore in bpo-32585(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32585  File: python.info, Node: tracemalloc, Next: types, Prev: tkinter<2>, Up: Improved Modules<2> 1.2.5.50 tracemalloc .................... *note tracemalloc.Traceback: 3ff. behaves more like regular tracebacks, sorting the frames from oldest to most recent. *note Traceback.format(): 400. now accepts negative `limit', truncating the result to the ‘abs(limit)’ oldest frames. To get the old behaviour, use the new `most_recent_first' argument to ‘Traceback.format()’. (Contributed by Jesse Bakker in bpo-32121(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32121  File: python.info, Node: types, Next: unicodedata<2>, Prev: tracemalloc, Up: Improved Modules<2> 1.2.5.51 types .............. The new *note WrapperDescriptorType: 402, *note MethodWrapperType: 403, *note MethodDescriptorType: 404, and *note ClassMethodDescriptorType: 405. classes are now available. (Contributed by Manuel Krebber and Guido van Rossum in bpo-29377(1), and Serhiy Storchaka in bpo-32265(2).) The new *note types.resolve_bases(): 406. function resolves MRO entries dynamically as specified by PEP 560(3). (Contributed by Ivan Levkivskyi in bpo-32717(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29377 (2) https://bugs.python.org/issue32265 (3) https://www.python.org/dev/peps/pep-0560 (4) https://bugs.python.org/issue32717  File: python.info, Node: unicodedata<2>, Next: unittest<2>, Prev: types, Up: Improved Modules<2> 1.2.5.52 unicodedata .................... The internal *note unicodedata: 11a. database has been upgraded to use Unicode 11(1). (Contributed by Benjamin Peterson.) ---------- Footnotes ---------- (1) http://www.unicode.org/versions/Unicode11.0.0/  File: python.info, Node: unittest<2>, Next: unittest mock, Prev: unicodedata<2>, Up: Improved Modules<2> 1.2.5.53 unittest ................. The new ‘-k’ command-line option allows filtering tests by a name substring or a Unix shell-like pattern. For example, ‘python -m unittest -k foo’ runs ‘foo_tests.SomeTest.test_something’, ‘bar_tests.SomeTest.test_foo’, but not ‘bar_tests.FooTest.test_something’. (Contributed by Jonas Haag in bpo-32071(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32071  File: python.info, Node: unittest mock, Next: urllib parse, Prev: unittest<2>, Up: Improved Modules<2> 1.2.5.54 unittest.mock ...................... The *note sentinel: 40a. attributes now preserve their identity when they are *note copied: 26. or *note pickled: ca. (Contributed by Serhiy Storchaka in bpo-20804(1).) The new *note seal(): 40b. function allows sealing *note Mock: 249. instances, which will disallow further creation of attribute mocks. The seal is applied recursively to all attributes that are themselves mocks. (Contributed by Mario Corchero in bpo-30541(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20804 (2) https://bugs.python.org/issue30541  File: python.info, Node: urllib parse, Next: uu, Prev: unittest mock, Up: Improved Modules<2> 1.2.5.55 urllib.parse ..................... *note urllib.parse.quote(): 40d. has been updated from RFC 2396(1) to RFC 3986(2), adding ‘~’ to the set of characters that are never quoted by default. (Contributed by Christian Theune and Ratnadeep Debnath in bpo-16285(3).) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2396.html (2) https://tools.ietf.org/html/rfc3986.html (3) https://bugs.python.org/issue16285  File: python.info, Node: uu, Next: uuid, Prev: urllib parse, Up: Improved Modules<2> 1.2.5.56 uu ........... The *note uu.encode(): 40f. function now accepts an optional `backtick' keyword argument. When it’s true, zeros are represented by ‘'`'’ instead of spaces. (Contributed by Xiang Zhang in bpo-30103(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30103  File: python.info, Node: uuid, Next: warnings, Prev: uu, Up: Improved Modules<2> 1.2.5.57 uuid ............. The new *note UUID.is_safe: 411. attribute relays information from the platform about whether generated UUIDs are generated with a multiprocessing-safe method. (Contributed by Barry Warsaw in bpo-22807(1).) *note uuid.getnode(): 412. now prefers universally administered MAC addresses over locally administered MAC addresses. This makes a better guarantee for global uniqueness of UUIDs returned from *note uuid.uuid1(): 413. If only locally administered MAC addresses are available, the first such one found is returned. (Contributed by Barry Warsaw in bpo-32107(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22807 (2) https://bugs.python.org/issue32107  File: python.info, Node: warnings, Next: xml etree, Prev: uuid, Up: Improved Modules<2> 1.2.5.58 warnings ................. The initialization of the default warnings filters has changed as follows: * warnings enabled via command line options (including those for *note -b: 415. and the new CPython-specific *note -X: 155. ‘dev’ option) are always passed to the warnings machinery via the *note sys.warnoptions: 416. attribute. * warnings filters enabled via the command line or the environment now have the following order of precedence: * the ‘BytesWarning’ filter for *note -b: 415. (or ‘-bb’) * any filters specified with the *note -W: 417. option * any filters specified with the *note PYTHONWARNINGS: 418. environment variable * any other CPython specific filters (e.g. the ‘default’ filter added for the new ‘-X dev’ mode) * any implicit filters defined directly by the warnings machinery * in CPython debug builds, all warnings are now displayed by default (the implicit filter list is empty) (Contributed by Nick Coghlan and Victor Stinner in bpo-20361(1), bpo-32043(2), and bpo-32230(3).) Deprecation warnings are once again shown by default in single-file scripts and at the interactive prompt. See *note PEP 565; Show DeprecationWarning in __main__: 303. for details. (Contributed by Nick Coghlan in bpo-31975(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20361 (2) https://bugs.python.org/issue32043 (3) https://bugs.python.org/issue32230 (4) https://bugs.python.org/issue31975  File: python.info, Node: xml etree, Next: xmlrpc server, Prev: warnings, Up: Improved Modules<2> 1.2.5.59 xml.etree .................. *note ElementPath: 41a. predicates in the ‘find()’ methods can now compare text of the current node with ‘[. = "text"]’, not only text in children. Predicates also allow adding spaces for better readability. (Contributed by Stefan Behnel in bpo-31648(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31648  File: python.info, Node: xmlrpc server, Next: zipapp, Prev: xml etree, Up: Improved Modules<2> 1.2.5.60 xmlrpc.server ...................... ‘SimpleXMLRPCDispatcher.register_function’ can now be used as a decorator. (Contributed by Xiang Zhang in bpo-7769(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue7769  File: python.info, Node: zipapp, Next: zipfile, Prev: xmlrpc server, Up: Improved Modules<2> 1.2.5.61 zipapp ............... Function *note create_archive(): 41d. now accepts an optional `filter' argument to allow the user to select which files should be included in the archive. (Contributed by Irmen de Jong in bpo-31072(1).) Function *note create_archive(): 41d. now accepts an optional `compressed' argument to generate a compressed archive. A command line option ‘--compress’ has also been added to support compression. (Contributed by Zhiming Wang in bpo-31638(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31072 (2) https://bugs.python.org/issue31638  File: python.info, Node: zipfile, Prev: zipapp, Up: Improved Modules<2> 1.2.5.62 zipfile ................ *note ZipFile: 41f. now accepts the new `compresslevel' parameter to control the compression level. (Contributed by Bo Bayles in bpo-21417(1).) Subdirectories in archives created by ‘ZipFile’ are now stored in alphabetical order. (Contributed by Bernhard M. Wiedemann in bpo-30693(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21417 (2) https://bugs.python.org/issue30693  File: python.info, Node: C API Changes, Next: Build Changes, Prev: Improved Modules<2>, Up: What’s New In Python 3 7 1.2.6 C API Changes ------------------- A new API for thread-local storage has been implemented. See *note PEP 539; New C API for Thread-Local Storage: 304. for an overview and *note Thread Specific Storage (TSS) API: 317. for a complete reference. (Contributed by Masayuki Yamamoto in bpo-25658(1).) The new *note context variables: 2f5. functionality exposes a number of *note new C APIs: 33b. The new *note PyImport_GetModule(): 421. function returns the previously imported module with the given name. (Contributed by Eric Snow in bpo-28411(2).) The new *note Py_RETURN_RICHCOMPARE: 422. macro eases writing rich comparison functions. (Contributed by Petr Victorin in bpo-23699(3).) The new *note Py_UNREACHABLE: 423. macro can be used to mark unreachable code paths. (Contributed by Barry Warsaw in bpo-31338(4).) The *note tracemalloc: 114. now exposes a C API through the new *note PyTraceMalloc_Track(): 424. and *note PyTraceMalloc_Untrack(): 425. functions. (Contributed by Victor Stinner in bpo-30054(5).) The new ‘import__find__load__start()’ and ‘import__find__load__done()’ static markers can be used to trace module imports. (Contributed by Christian Heimes in bpo-31574(6).) The fields ‘name’ and ‘doc’ of structures *note PyMemberDef: 426, *note PyGetSetDef: 427, *note PyStructSequence_Field: 428, *note PyStructSequence_Desc: 429, and ‘wrapperbase’ are now of type ‘const char *’ rather of ‘char *’. (Contributed by Serhiy Storchaka in bpo-28761(7).) The result of *note PyUnicode_AsUTF8AndSize(): 42a. and *note PyUnicode_AsUTF8(): 42b. is now of type ‘const char *’ rather of ‘char *’. (Contributed by Serhiy Storchaka in bpo-28769(8).) The result of *note PyMapping_Keys(): 42c, *note PyMapping_Values(): 42d. and *note PyMapping_Items(): 42e. is now always a list, rather than a list or a tuple. (Contributed by Oren Milman in bpo-28280(9).) Added functions *note PySlice_Unpack(): 42f. and *note PySlice_AdjustIndices(): 430. (Contributed by Serhiy Storchaka in bpo-27867(10).) *note PyOS_AfterFork(): 431. is deprecated in favour of the new functions *note PyOS_BeforeFork(): 432, *note PyOS_AfterFork_Parent(): 433. and *note PyOS_AfterFork_Child(): 2cd. (Contributed by Antoine Pitrou in bpo-16500(11).) The ‘PyExc_RecursionErrorInst’ singleton that was part of the public API has been removed as its members being never cleared may cause a segfault during finalization of the interpreter. Contributed by Xavier de Gaye in bpo-22898(12) and bpo-30697(13). Added C API support for timezones with timezone constructors *note PyTimeZone_FromOffset(): 434. and *note PyTimeZone_FromOffsetAndName(): 435, and access to the UTC singleton with *note PyDateTime_TimeZone_UTC: 436. Contributed by Paul Ganssle in bpo-10381(14). The type of results of ‘PyThread_start_new_thread()’ and ‘PyThread_get_thread_ident()’, and the `id' parameter of *note PyThreadState_SetAsyncExc(): 437. changed from ‘long’ to ‘unsigned long’. (Contributed by Serhiy Storchaka in bpo-6532(15).) *note PyUnicode_AsWideCharString(): 438. now raises a *note ValueError: 1fb. if the second argument is ‘NULL’ and the ‘wchar_t*’ string contains null characters. (Contributed by Serhiy Storchaka in bpo-30708(16).) Changes to the startup sequence and the management of dynamic memory allocators mean that the long documented requirement to call *note Py_Initialize(): 439. before calling most C API functions is now relied on more heavily, and failing to abide by it may lead to segfaults in embedding applications. See the *note Porting to Python 3.7: 307. section in this document and the *note Before Python Initialization: 43a. section in the C API documentation for more details. The new *note PyInterpreterState_GetID(): 43b. returns the unique ID for a given interpreter. (Contributed by Eric Snow in bpo-29102(17).) *note Py_DecodeLocale(): 43c, *note Py_EncodeLocale(): 43d. now use the UTF-8 encoding when the *note UTF-8 mode: 300. is enabled. (Contributed by Victor Stinner in bpo-29240(18).) *note PyUnicode_DecodeLocaleAndSize(): 43e. and *note PyUnicode_EncodeLocale(): 43f. now use the current locale encoding for ‘surrogateescape’ error handler. (Contributed by Victor Stinner in bpo-29240(19).) The `start' and `end' parameters of *note PyUnicode_FindChar(): 440. are now adjusted to behave like string slices. (Contributed by Xiang Zhang in bpo-28822(20).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25658 (2) https://bugs.python.org/issue28411 (3) https://bugs.python.org/issue23699 (4) https://bugs.python.org/issue31338 (5) https://bugs.python.org/issue30054 (6) https://bugs.python.org/issue31574 (7) https://bugs.python.org/issue28761 (8) https://bugs.python.org/issue28769 (9) https://bugs.python.org/issue28280 (10) https://bugs.python.org/issue27867 (11) https://bugs.python.org/issue16500 (12) https://bugs.python.org/issue22898 (13) https://bugs.python.org/issue30697 (14) https://bugs.python.org/issue10381 (15) https://bugs.python.org/issue6532 (16) https://bugs.python.org/issue30708 (17) https://bugs.python.org/issue29102 (18) https://bugs.python.org/issue29240 (19) https://bugs.python.org/issue29240 (20) https://bugs.python.org/issue28822  File: python.info, Node: Build Changes, Next: Optimizations<2>, Prev: C API Changes, Up: What’s New In Python 3 7 1.2.7 Build Changes ------------------- Support for building ‘--without-threads’ has been removed. The *note threading: 109. module is now always available. (Contributed by Antoine Pitrou in bpo-31370(1).). A full copy of libffi is no longer bundled for use when building the *note _ctypes: 2b. module on non-OSX UNIX platforms. An installed copy of libffi is now required when building ‘_ctypes’ on such platforms. (Contributed by Zachary Ware in bpo-27979(2).) The Windows build process no longer depends on Subversion to pull in external sources, a Python script is used to download zipfiles from GitHub instead. If Python 3.6 is not found on the system (via ‘py -3.6’), NuGet is used to download a copy of 32-bit Python for this purpose. (Contributed by Zachary Ware in bpo-30450(3).) The *note ssl: f3. module requires OpenSSL 1.0.2 or 1.1 compatible libssl. OpenSSL 1.0.1 has reached end of lifetime on 2016-12-31 and is no longer supported. LibreSSL is temporarily not supported as well. LibreSSL releases up to version 2.6.4 are missing required OpenSSL 1.0.2 APIs. ---------- Footnotes ---------- (1) https://bugs.python.org/issue31370 (2) https://bugs.python.org/issue27979 (3) https://bugs.python.org/issue30450  File: python.info, Node: Optimizations<2>, Next: Other CPython Implementation Changes, Prev: Build Changes, Up: What’s New In Python 3 7 1.2.8 Optimizations ------------------- The overhead of calling many methods of various standard library classes implemented in C has been significantly reduced by porting more code to use the ‘METH_FASTCALL’ convention. (Contributed by Victor Stinner in bpo-29300(1), bpo-29507(2), bpo-29452(3), and bpo-29286(4).) Various optimizations have reduced Python startup time by 10% on Linux and up to 30% on macOS. (Contributed by Victor Stinner, INADA Naoki in bpo-29585(5), and Ivan Levkivskyi in bpo-31333(6).) Method calls are now up to 20% faster due to the bytecode changes which avoid creating bound method instances. (Contributed by Yury Selivanov and INADA Naoki in bpo-26110(7).) The *note asyncio: a. module received a number of notable optimizations for commonly used functions: * The *note asyncio.get_event_loop(): 355. function has been reimplemented in C to make it up to 15 times faster. (Contributed by Yury Selivanov in bpo-32296(8).) * *note asyncio.Future: 443. callback management has been optimized. (Contributed by Yury Selivanov in bpo-32348(9).) * *note asyncio.gather(): 286. is now up to 15% faster. (Contributed by Yury Selivanov in bpo-32355(10).) * *note asyncio.sleep(): 285. is now up to 2 times faster when the `delay' argument is zero or negative. (Contributed by Andrew Svetlov in bpo-32351(11).) * The performance overhead of asyncio debug mode has been reduced. (Contributed by Antoine Pitrou in bpo-31970(12).) As a result of *note PEP 560 work: 2fb, the import time of *note typing: 119. has been reduced by a factor of 7, and many typing operations are now faster. (Contributed by Ivan Levkivskyi in bpo-32226(13).) *note sorted(): 444. and *note list.sort(): 445. have been optimized for common cases to be up to 40-75% faster. (Contributed by Elliot Gorokhovsky in bpo-28685(14).) *note dict.copy(): 446. is now up to 5.5 times faster. (Contributed by Yury Selivanov in bpo-31179(15).) *note hasattr(): 447. and *note getattr(): 448. are now about 4 times faster when `name' is not found and `obj' does not override *note object.__getattr__(): 31a. or *note object.__getattribute__(): 449. (Contributed by INADA Naoki in bpo-32544(16).) Searching for certain Unicode characters (like Ukrainian capital “Є”) in a string was up to 25 times slower than searching for other characters. It is now only 3 times slower in the worst case. (Contributed by Serhiy Storchaka in bpo-24821(17).) The *note collections.namedtuple(): 1b7. factory has been reimplemented to make the creation of named tuples 4 to 6 times faster. (Contributed by Jelle Zijlstra with further improvements by INADA Naoki, Serhiy Storchaka, and Raymond Hettinger in bpo-28638(18).) ‘date.fromordinal()’ and ‘date.fromtimestamp()’ are now up to 30% faster in the common case. (Contributed by Paul Ganssle in bpo-32403(19).) The *note os.fwalk(): 3b4. function is now up to 2 times faster thanks to the use of *note os.scandir(): 25f. (Contributed by Serhiy Storchaka in bpo-25996(20).) The speed of the *note shutil.rmtree(): 21c. function has been improved by 20–40% thanks to the use of the *note os.scandir(): 25f. function. (Contributed by Serhiy Storchaka in bpo-28564(21).) Optimized case-insensitive matching and searching of *note regular expressions: dd. Searching some patterns can now be up to 20 times faster. (Contributed by Serhiy Storchaka in bpo-30285(22).) *note re.compile(): 44a. now converts ‘flags’ parameter to int object if it is ‘RegexFlag’. It is now as fast as Python 3.5, and faster than Python 3.6 by about 10% depending on the pattern. (Contributed by INADA Naoki in bpo-31671(23).) The *note modify(): 44b. methods of classes *note selectors.EpollSelector: 44c, *note selectors.PollSelector: 44d. and *note selectors.DevpollSelector: 44e. may be around 10% faster under heavy loads. (Contributed by Giampaolo Rodola’ in bpo-30014(24)) Constant folding has been moved from the peephole optimizer to the new AST optimizer, which is able perform optimizations more consistently. (Contributed by Eugene Toder and INADA Naoki in bpo-29469(25) and bpo-11549(26).) Most functions and methods in *note abc: 4. have been rewritten in C. This makes creation of abstract base classes, and calling *note isinstance(): 44f. and *note issubclass(): 450. on them 1.5x faster. This also reduces Python start-up time by up to 10%. (Contributed by Ivan Levkivskyi and INADA Naoki in bpo-31333(27)) Significant speed improvements to alternate constructors for *note datetime.date: 193. and *note datetime.datetime: 194. by using fast-path constructors when not constructing subclasses. (Contributed by Paul Ganssle in bpo-32403(28)) The speed of comparison of *note array.array: 451. instances has been improved considerably in certain cases. It is now from 10x to 70x faster when comparing arrays holding values of the same integer type. (Contributed by Adrian Wielgosik in bpo-24700(29).) The *note math.erf(): 452. and *note math.erfc(): 453. functions now use the (faster) C library implementation on most platforms. (Contributed by Serhiy Storchaka in bpo-26121(30).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29300 (2) https://bugs.python.org/issue29507 (3) https://bugs.python.org/issue29452 (4) https://bugs.python.org/issue29286 (5) https://bugs.python.org/issue29585 (6) https://bugs.python.org/issue31333 (7) https://bugs.python.org/issue26110 (8) https://bugs.python.org/issue32296 (9) https://bugs.python.org/issue32348 (10) https://bugs.python.org/issue32355 (11) https://bugs.python.org/issue32351 (12) https://bugs.python.org/issue31970 (13) https://bugs.python.org/issue32226 (14) https://bugs.python.org/issue28685 (15) https://bugs.python.org/issue31179 (16) https://bugs.python.org/issue32544 (17) https://bugs.python.org/issue24821 (18) https://bugs.python.org/issue28638 (19) https://bugs.python.org/issue32403 (20) https://bugs.python.org/issue25996 (21) https://bugs.python.org/issue28564 (22) https://bugs.python.org/issue30285 (23) https://bugs.python.org/issue31671 (24) https://bugs.python.org/issue30014 (25) https://bugs.python.org/issue29469 (26) https://bugs.python.org/issue11549 (27) https://bugs.python.org/issue31333 (28) https://bugs.python.org/issue32403 (29) https://bugs.python.org/issue24700 (30) https://bugs.python.org/issue26121  File: python.info, Node: Other CPython Implementation Changes, Next: Deprecated Python Behavior, Prev: Optimizations<2>, Up: What’s New In Python 3 7 1.2.9 Other CPython Implementation Changes ------------------------------------------ * Trace hooks may now opt out of receiving the ‘line’ and opt into receiving the ‘opcode’ events from the interpreter by setting the corresponding new ‘f_trace_lines’ and ‘f_trace_opcodes’ attributes on the frame being traced. (Contributed by Nick Coghlan in bpo-31344(1).) * Fixed some consistency problems with namespace package module attributes. Namespace module objects now have an ‘__file__’ that is set to ‘None’ (previously unset), and their ‘__spec__.origin’ is also set to ‘None’ (previously the string ‘"namespace"’). See bpo-32305(2). Also, the namespace module object’s ‘__spec__.loader’ is set to the same value as ‘__loader__’ (previously, the former was set to ‘None’). See bpo-32303(3). * The *note locals(): 455. dictionary now displays in the lexical order that variables were defined. Previously, the order was undefined. (Contributed by Raymond Hettinger in bpo-32690(4).) * The *note distutils: 39. ‘upload’ command no longer tries to change CR end-of-line characters to CRLF. This fixes a corruption issue with sdists that ended with a byte equivalent to CR. (Contributed by Bo Bayles in bpo-32304(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31344 (2) https://bugs.python.org/issue32305 (3) https://bugs.python.org/issue32303 (4) https://bugs.python.org/issue32690 (5) https://bugs.python.org/issue32304  File: python.info, Node: Deprecated Python Behavior, Next: Deprecated Python modules functions and methods, Prev: Other CPython Implementation Changes, Up: What’s New In Python 3 7 1.2.10 Deprecated Python Behavior --------------------------------- Yield expressions (both ‘yield’ and ‘yield from’ clauses) are now deprecated in comprehensions and generator expressions (aside from the iterable expression in the leftmost ‘for’ clause). This ensures that comprehensions always immediately return a container of the appropriate type (rather than potentially returning a *note generator iterator: 457. object), while generator expressions won’t attempt to interleave their implicit output with the output from any explicit yield expressions. In Python 3.7, such expressions emit *note DeprecationWarning: 278. when compiled, in Python 3.8 this will be a *note SyntaxError: 458. (Contributed by Serhiy Storchaka in bpo-10544(1).) Returning a subclass of *note complex: 189. from *note object.__complex__(): 18d. is deprecated and will be an error in future Python versions. This makes ‘__complex__()’ consistent with *note object.__int__(): 18b. and *note object.__float__(): 18c. (Contributed by Serhiy Storchaka in bpo-28894(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10544 (2) https://bugs.python.org/issue28894  File: python.info, Node: Deprecated Python modules functions and methods, Next: Deprecated functions and types of the C API, Prev: Deprecated Python Behavior, Up: What’s New In Python 3 7 1.2.11 Deprecated Python modules, functions and methods ------------------------------------------------------- * Menu: * aifc:: * asyncio: asyncio<3>. * collections: collections<3>. * dbm: dbm<2>. * enum: enum<2>. * gettext: gettext<2>. * importlib: importlib<2>. * locale: locale<2>. * macpath:: * threading: threading<2>. * socket: socket<3>. * ssl: ssl<3>. * sunau:: * sys: sys<3>. * wave::  File: python.info, Node: aifc, Next: asyncio<3>, Up: Deprecated Python modules functions and methods 1.2.11.1 aifc ............. ‘aifc.openfp()’ has been deprecated and will be removed in Python 3.9. Use *note aifc.open(): 45b. instead. (Contributed by Brian Curtin in bpo-31985(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31985  File: python.info, Node: asyncio<3>, Next: collections<3>, Prev: aifc, Up: Deprecated Python modules functions and methods 1.2.11.2 asyncio ................ Support for directly ‘await’-ing instances of *note asyncio.Lock: 28b. and other asyncio synchronization primitives has been deprecated. An asynchronous context manager must be used in order to acquire and release the synchronization resource. (Contributed by Andrew Svetlov in bpo-32253(1).) The *note asyncio.Task.current_task(): 352. and *note asyncio.Task.all_tasks(): 353. methods have been deprecated. (Contributed by Andrew Svetlov in bpo-32250(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue32253 (2) https://bugs.python.org/issue32250  File: python.info, Node: collections<3>, Next: dbm<2>, Prev: asyncio<3>, Up: Deprecated Python modules functions and methods 1.2.11.3 collections .................... In Python 3.8, the abstract base classes in *note collections.abc: 1f. will no longer be exposed in the regular *note collections: 1e. module. This will help create a clearer distinction between the concrete classes and the abstract base classes. (Contributed by Serhiy Storchaka in bpo-25988(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25988  File: python.info, Node: dbm<2>, Next: enum<2>, Prev: collections<3>, Up: Deprecated Python modules functions and methods 1.2.11.4 dbm ............ *note dbm.dumb: 33. now supports reading read-only files and no longer writes the index file when it is not changed. A deprecation warning is now emitted if the index file is missing and recreated in the ‘'r'’ and ‘'w'’ modes (this will be an error in future Python releases). (Contributed by Serhiy Storchaka in bpo-28847(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28847  File: python.info, Node: enum<2>, Next: gettext<2>, Prev: dbm<2>, Up: Deprecated Python modules functions and methods 1.2.11.5 enum ............. In Python 3.8, attempting to check for non-Enum objects in ‘Enum’ classes will raise a *note TypeError: 192. (e.g. ‘1 in Color’); similarly, attempting to check for non-Flag objects in a ‘Flag’ member will raise *note TypeError: 192. (e.g. ‘1 in Perm.RW’); currently, both operations return *note False: 388. instead. (Contributed by Ethan Furman in bpo-33217(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33217  File: python.info, Node: gettext<2>, Next: importlib<2>, Prev: enum<2>, Up: Deprecated Python modules functions and methods 1.2.11.6 gettext ................ Using non-integer value for selecting a plural form in *note gettext: 89. is now deprecated. It never correctly worked. (Contributed by Serhiy Storchaka in bpo-28692(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28692  File: python.info, Node: importlib<2>, Next: locale<2>, Prev: gettext<2>, Up: Deprecated Python modules functions and methods 1.2.11.7 importlib .................. Methods *note MetaPathFinder.find_module(): 462. (replaced by *note MetaPathFinder.find_spec(): 463.) and *note PathEntryFinder.find_loader(): 464. (replaced by *note PathEntryFinder.find_spec(): 465.) both deprecated in Python 3.4 now emit *note DeprecationWarning: 278. (Contributed by Matthias Bussonnier in bpo-29576(1)) The *note importlib.abc.ResourceLoader: 466. ABC has been deprecated in favour of *note importlib.abc.ResourceReader: 342. ---------- Footnotes ---------- (1) https://bugs.python.org/issue29576  File: python.info, Node: locale<2>, Next: macpath, Prev: importlib<2>, Up: Deprecated Python modules functions and methods 1.2.11.8 locale ............... *note locale.format(): 468. has been deprecated, use *note locale.format_string(): 3a4. instead. (Contributed by Garvit in bpo-10379(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10379  File: python.info, Node: macpath, Next: threading<2>, Prev: locale<2>, Up: Deprecated Python modules functions and methods 1.2.11.9 macpath ................ The ‘macpath’ is now deprecated and will be removed in Python 3.8. (Contributed by Chi Hsuan Yen in bpo-9850(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9850  File: python.info, Node: threading<2>, Next: socket<3>, Prev: macpath, Up: Deprecated Python modules functions and methods 1.2.11.10 threading ................... *note dummy_threading: 68. and *note _dummy_thread: 2. have been deprecated. It is no longer possible to build Python with threading disabled. Use *note threading: 109. instead. (Contributed by Antoine Pitrou in bpo-31370(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31370  File: python.info, Node: socket<3>, Next: ssl<3>, Prev: threading<2>, Up: Deprecated Python modules functions and methods 1.2.11.11 socket ................ The silent argument value truncation in *note socket.htons(): 46c. and *note socket.ntohs(): 46d. has been deprecated. In future versions of Python, if the passed argument is larger than 16 bits, an exception will be raised. (Contributed by Oren Milman in bpo-28332(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28332  File: python.info, Node: ssl<3>, Next: sunau, Prev: socket<3>, Up: Deprecated Python modules functions and methods 1.2.11.12 ssl ............. *note ssl.wrap_socket(): 46f. is deprecated. Use *note ssl.SSLContext.wrap_socket(): 3e5. instead. (Contributed by Christian Heimes in bpo-28124(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28124  File: python.info, Node: sunau, Next: sys<3>, Prev: ssl<3>, Up: Deprecated Python modules functions and methods 1.2.11.13 sunau ............... *note sunau.openfp(): 471. has been deprecated and will be removed in Python 3.9. Use *note sunau.open(): 472. instead. (Contributed by Brian Curtin in bpo-31985(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31985  File: python.info, Node: sys<3>, Next: wave, Prev: sunau, Up: Deprecated Python modules functions and methods 1.2.11.14 sys ............. Deprecated ‘sys.set_coroutine_wrapper()’ and ‘sys.get_coroutine_wrapper()’. The undocumented ‘sys.callstats()’ function has been deprecated and will be removed in a future Python version. (Contributed by Victor Stinner in bpo-28799(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28799  File: python.info, Node: wave, Prev: sys<3>, Up: Deprecated Python modules functions and methods 1.2.11.15 wave .............. *note wave.openfp(): 475. has been deprecated and will be removed in Python 3.9. Use *note wave.open(): 476. instead. (Contributed by Brian Curtin in bpo-31985(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31985  File: python.info, Node: Deprecated functions and types of the C API, Next: Platform Support Removals, Prev: Deprecated Python modules functions and methods, Up: What’s New In Python 3 7 1.2.12 Deprecated functions and types of the C API -------------------------------------------------- Function *note PySlice_GetIndicesEx(): 478. is deprecated and replaced with a macro if ‘Py_LIMITED_API’ is not set or set to a value in the range between ‘0x03050400’ and ‘0x03060000’ (not inclusive), or is ‘0x03060100’ or higher. (Contributed by Serhiy Storchaka in bpo-27867(1).) *note PyOS_AfterFork(): 431. has been deprecated. Use *note PyOS_BeforeFork(): 432, *note PyOS_AfterFork_Parent(): 433. or *note PyOS_AfterFork_Child(): 2cd. instead. (Contributed by Antoine Pitrou in bpo-16500(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27867 (2) https://bugs.python.org/issue16500  File: python.info, Node: Platform Support Removals, Next: API and Feature Removals<2>, Prev: Deprecated functions and types of the C API, Up: What’s New In Python 3 7 1.2.13 Platform Support Removals -------------------------------- * FreeBSD 9 and older are no longer officially supported. * For full Unicode support, including within extension modules, *nix platforms are now expected to provide at least one of ‘C.UTF-8’ (full locale), ‘C.utf8’ (full locale) or ‘UTF-8’ (‘LC_CTYPE’-only locale) as an alternative to the legacy ‘ASCII’-based ‘C’ locale. * OpenSSL 0.9.8 and 1.0.1 are no longer supported, which means building CPython 3.7 with SSL/TLS support on older platforms still using these versions requires custom build options that link to a more recent version of OpenSSL. Notably, this issue affects the Debian 8 (aka “jessie”) and Ubuntu 14.04 (aka “Trusty”) LTS Linux distributions, as they still use OpenSSL 1.0.1 by default. Debian 9 (“stretch”) and Ubuntu 16.04 (“xenial”), as well as recent releases of other LTS Linux releases (e.g. RHEL/CentOS 7.5, SLES 12-SP3), use OpenSSL 1.0.2 or later, and remain supported in the default build configuration. CPython’s own CI configuration file(1) provides an example of using the SSL compatibility testing infrastructure(2) in CPython’s test suite to build and link against OpenSSL 1.1.0 rather than an outdated system provided OpenSSL. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/.travis.yml (2) https://github.com/python/cpython/tree/3.8/Tools/ssl/multissltests.py  File: python.info, Node: API and Feature Removals<2>, Next: Module Removals, Prev: Platform Support Removals, Up: What’s New In Python 3 7 1.2.14 API and Feature Removals ------------------------------- The following features and APIs have been removed from Python 3.7: * The ‘os.stat_float_times()’ function has been removed. It was introduced in Python 2.3 for backward compatibility with Python 2.2, and was deprecated since Python 3.1. * Unknown escapes consisting of ‘'\'’ and an ASCII letter in replacement templates for *note re.sub(): 47b. were deprecated in Python 3.5, and will now cause an error. * Removed support of the `exclude' argument in *note tarfile.TarFile.add(): 47c. It was deprecated in Python 2.7 and 3.2. Use the `filter' argument instead. * The ‘splitunc()’ function in the ‘ntpath’ module was deprecated in Python 3.1, and has now been removed. Use the *note splitdrive(): 47d. function instead. * *note collections.namedtuple(): 1b7. no longer supports the `verbose' parameter or ‘_source’ attribute which showed the generated source code for the named tuple class. This was part of an optimization designed to speed-up class creation. (Contributed by Jelle Zijlstra with further improvements by INADA Naoki, Serhiy Storchaka, and Raymond Hettinger in bpo-28638(1).) * Functions *note bool(): 183, *note float(): 187, *note list(): 262. and *note tuple(): 47e. no longer take keyword arguments. The first argument of *note int(): 184. can now be passed only as positional argument. * Removed previously deprecated in Python 2.4 classes ‘Plist’, ‘Dict’ and ‘_InternalDict’ in the *note plistlib: cf. module. Dict values in the result of functions *note readPlist(): 47f. and *note readPlistFromBytes(): 480. are now normal dicts. You no longer can use attribute access to access items of these dictionaries. * The ‘asyncio.windows_utils.socketpair()’ function has been removed. Use the *note socket.socketpair(): 481. function instead, it is available on all platforms since Python 3.5. ‘asyncio.windows_utils.socketpair’ was just an alias to ‘socket.socketpair’ on Python 3.5 and newer. * *note asyncio: a. no longer exports the *note selectors: e6. and ‘_overlapped’ modules as ‘asyncio.selectors’ and ‘asyncio._overlapped’. Replace ‘from asyncio import selectors’ with ‘import selectors’. * Direct instantiation of *note ssl.SSLSocket: 3e2. and *note ssl.SSLObject: 3e3. objects is now prohibited. The constructors were never documented, tested, or designed as public constructors. Users were supposed to use *note ssl.wrap_socket(): 46f. or *note ssl.SSLContext: 3e4. (Contributed by Christian Heimes in bpo-32951(2).) * The unused *note distutils: 39. ‘install_misc’ command has been removed. (Contributed by Eric N. Vander Weele in bpo-29218(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28638 (2) https://bugs.python.org/issue32951 (3) https://bugs.python.org/issue29218  File: python.info, Node: Module Removals, Next: Windows-only Changes, Prev: API and Feature Removals<2>, Up: What’s New In Python 3 7 1.2.15 Module Removals ---------------------- The ‘fpectl’ module has been removed. It was never enabled by default, never worked correctly on x86-64, and it changed the Python ABI in ways that caused unexpected breakage of C extensions. (Contributed by Nathaniel J. Smith in bpo-29137(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue29137  File: python.info, Node: Windows-only Changes, Next: Porting to Python 3 7, Prev: Module Removals, Up: What’s New In Python 3 7 1.2.16 Windows-only Changes --------------------------- The python launcher, (py.exe), can accept 32 & 64 bit specifiers `without' having to specify a minor version as well. So ‘py -3-32’ and ‘py -3-64’ become valid as well as ‘py -3.7-32’, also the -`m'-64 and -`m.n'-64 forms are now accepted to force 64 bit python even if 32 bit would have otherwise been used. If the specified version is not available py.exe will error exit. (Contributed by Steve Barnes in bpo-30291(1).) The launcher can be run as ‘py -0’ to produce a list of the installed pythons, `with default marked with an asterisk'. Running ‘py -0p’ will include the paths. If py is run with a version specifier that cannot be matched it will also print the `short form' list of available specifiers. (Contributed by Steve Barnes in bpo-30362(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue30291 (2) https://bugs.python.org/issue30362  File: python.info, Node: Porting to Python 3 7, Next: Notable changes in Python 3 7 1, Prev: Windows-only Changes, Up: What’s New In Python 3 7 1.2.17 Porting to Python 3.7 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Changes in Python Behavior:: * Changes in the Python API: Changes in the Python API<2>. * Changes in the C API: Changes in the C API<2>. * CPython bytecode changes: CPython bytecode changes<2>. * Windows-only Changes: Windows-only Changes<2>. * Other CPython implementation changes::  File: python.info, Node: Changes in Python Behavior, Next: Changes in the Python API<2>, Up: Porting to Python 3 7 1.2.17.1 Changes in Python Behavior ................................... * *note async: 1a2. and *note await: 1a3. names are now reserved keywords. Code using these names as identifiers will now raise a *note SyntaxError: 458. (Contributed by Jelle Zijlstra in bpo-30406(1).) * PEP 479(2) is enabled for all code in Python 3.7, meaning that *note StopIteration: 486. exceptions raised directly or indirectly in coroutines and generators are transformed into *note RuntimeError: 2ba. exceptions. (Contributed by Yury Selivanov in bpo-32670(3).) * *note object.__aiter__(): 487. methods can no longer be declared as asynchronous. (Contributed by Yury Selivanov in bpo-31709(4).) * Due to an oversight, earlier Python versions erroneously accepted the following syntax: f(1 for x in [1],) class C(1 for x in [1]): pass Python 3.7 now correctly raises a *note SyntaxError: 458, as a generator expression always needs to be directly inside a set of parentheses and cannot have a comma on either side, and the duplication of the parentheses can be omitted only on calls. (Contributed by Serhiy Storchaka in bpo-32012(5) and bpo-32023(6).) * When using the *note -m: 337. switch, the initial working directory is now added to *note sys.path: 488, rather than an empty string (which dynamically denoted the current working directory at the time of each import). Any programs that are checking for the empty string, or otherwise relying on the previous behaviour, will need to be updated accordingly (e.g. by also checking for ‘os.getcwd()’ or ‘os.path.dirname(__main__.__file__)’, depending on why the code was checking for the empty string in the first place). ---------- Footnotes ---------- (1) https://bugs.python.org/issue30406 (2) https://www.python.org/dev/peps/pep-0479 (3) https://bugs.python.org/issue32670 (4) https://bugs.python.org/issue31709 (5) https://bugs.python.org/issue32012 (6) https://bugs.python.org/issue32023  File: python.info, Node: Changes in the Python API<2>, Next: Changes in the C API<2>, Prev: Changes in Python Behavior, Up: Porting to Python 3 7 1.2.17.2 Changes in the Python API .................................. * ‘socketserver.ThreadingMixIn.server_close()’ now waits until all non-daemon threads complete. Set the new ‘socketserver.ThreadingMixIn.block_on_close’ class attribute to ‘False’ to get the pre-3.7 behaviour. (Contributed by Victor Stinner in bpo-31233(1) and bpo-33540(2).) * ‘socketserver.ForkingMixIn.server_close()’ now waits until all child processes complete. Set the new ‘socketserver.ForkingMixIn.block_on_close’ class attribute to ‘False’ to get the pre-3.7 behaviour. (Contributed by Victor Stinner in bpo-31151(3) and bpo-33540(4).) * The *note locale.localeconv(): 48a. function now temporarily sets the ‘LC_CTYPE’ locale to the value of ‘LC_NUMERIC’ in some cases. (Contributed by Victor Stinner in bpo-31900(5).) * *note pkgutil.walk_packages(): 48b. now raises a *note ValueError: 1fb. if `path' is a string. Previously an empty list was returned. (Contributed by Sanyam Khurana in bpo-24744(6).) * A format string argument for *note string.Formatter.format(): 48c. is now *note positional-only: 2a7. Passing it as a keyword argument was deprecated in Python 3.5. (Contributed by Serhiy Storchaka in bpo-29193(7).) * Attributes *note key: 48d, *note value: 48e. and *note coded_value: 48f. of class *note http.cookies.Morsel: 490. are now read-only. Assigning to them was deprecated in Python 3.5. Use the *note set(): 491. method for setting them. (Contributed by Serhiy Storchaka in bpo-29192(8).) * The `mode' argument of *note os.makedirs(): 3bd. no longer affects the file permission bits of newly-created intermediate-level directories. To set their file permission bits you can set the umask before invoking ‘makedirs()’. (Contributed by Serhiy Storchaka in bpo-19930(9).) * The *note struct.Struct.format: 492. type is now *note str: 330. instead of *note bytes: 331. (Contributed by Victor Stinner in bpo-21071(10).) * *note parse_multipart(): 2ee. now accepts the `encoding' and `errors' arguments and returns the same results as ‘FieldStorage’: for non-file fields, the value associated to a key is a list of strings, not bytes. (Contributed by Pierre Quentel in bpo-29979(11).) * Due to internal changes in *note socket: ef, calling *note socket.fromshare(): 493. on a socket created by *note socket.share: 494. in older Python versions is not supported. * ‘repr’ for *note BaseException: 1a8. has changed to not include the trailing comma. Most exceptions are affected by this change. (Contributed by Serhiy Storchaka in bpo-30399(12).) * ‘repr’ for *note datetime.timedelta: 195. has changed to include the keyword arguments in the output. (Contributed by Utkarsh Upadhyay in bpo-30302(13).) * Because *note shutil.rmtree(): 21c. is now implemented using the *note os.scandir(): 25f. function, the user specified handler `onerror' is now called with the first argument ‘os.scandir’ instead of ‘os.listdir’ when listing the directory is failed. * Support for nested sets and set operations in regular expressions as in Unicode Technical Standard #18(14) might be added in the future. This would change the syntax. To facilitate this future change a *note FutureWarning: 325. will be raised in ambiguous cases for the time being. That include sets starting with a literal ‘'['’ or containing literal character sequences ‘'--'’, ‘'&&'’, ‘'~~'’, and ‘'||'’. To avoid a warning, escape them with a backslash. (Contributed by Serhiy Storchaka in bpo-30349(15).) * The result of splitting a string on a *note regular expression: dd. that could match an empty string has been changed. For example splitting on ‘r'\s*'’ will now split not only on whitespaces as it did previously, but also on empty strings before all non-whitespace characters and just before the end of the string. The previous behavior can be restored by changing the pattern to ‘r'\s+'’. A *note FutureWarning: 325. was emitted for such patterns since Python 3.5. For patterns that match both empty and non-empty strings, the result of searching for all matches may also be changed in other cases. For example in the string ‘'a\n\n'’, the pattern ‘r'(?m)^\s*?$'’ will not only match empty strings at positions 2 and 3, but also the string ‘'\n'’ at positions 2–3. To match only blank lines, the pattern should be rewritten as ‘r'(?m)^[^\S\n]*$'’. *note re.sub(): 47b. now replaces empty matches adjacent to a previous non-empty match. For example ‘re.sub('x*', '-', 'abxd')’ returns now ‘'-a-b--d-'’ instead of ‘'-a-b-d-'’ (the first minus between ‘b’ and ‘d’ replaces ‘x’, and the second minus replaces an empty string between ‘x’ and ‘d’). (Contributed by Serhiy Storchaka in bpo-25054(16) and bpo-32308(17).) * Change *note re.escape(): 495. to only escape regex special characters instead of escaping all characters other than ASCII letters, numbers, and ‘'_'’. (Contributed by Serhiy Storchaka in bpo-29995(18).) * *note tracemalloc.Traceback: 3ff. frames are now sorted from oldest to most recent to be more consistent with *note traceback: 113. (Contributed by Jesse Bakker in bpo-32121(19).) * On OSes that support *note socket.SOCK_NONBLOCK: 496. or *note socket.SOCK_CLOEXEC: 497. bit flags, the *note socket.type: 498. no longer has them applied. Therefore, checks like ‘if sock.type == socket.SOCK_STREAM’ work as expected on all platforms. (Contributed by Yury Selivanov in bpo-32331(20).) * On Windows the default for the `close_fds' argument of *note subprocess.Popen: 2b9. was changed from *note False: 388. to *note True: 499. when redirecting the standard handles. If you previously depended on handles being inherited when using *note subprocess.Popen: 2b9. with standard io redirection, you will have to pass ‘close_fds=False’ to preserve the previous behaviour, or use *note STARTUPINFO.lpAttributeList: 49a. * *note importlib.machinery.PathFinder.invalidate_caches(): 49b. – which implicitly affects *note importlib.invalidate_caches(): 49c. – now deletes entries in *note sys.path_importer_cache: 49d. which are set to ‘None’. (Contributed by Brett Cannon in bpo-33169(21).) * In *note asyncio: a, *note loop.sock_recv(): 49e, *note loop.sock_sendall(): 49f, *note loop.sock_accept(): 4a0, *note loop.getaddrinfo(): 4a1, *note loop.getnameinfo(): 4a2. have been changed to be proper coroutine methods to match their documentation. Previously, these methods returned *note asyncio.Future: 443. instances. (Contributed by Yury Selivanov in bpo-32327(22).) * *note asyncio.Server.sockets: 4a3. now returns a copy of the internal list of server sockets, instead of returning it directly. (Contributed by Yury Selivanov in bpo-32662(23).) * *note Struct.format: 492. is now a *note str: 330. instance instead of a *note bytes: 331. instance. (Contributed by Victor Stinner in bpo-21071(24).) * *note argparse: 6. subparsers can now be made mandatory by passing ‘required=True’ to *note ArgumentParser.add_subparsers(): 4a4. (Contributed by Anthony Sottile in bpo-26510(25).) * *note ast.literal_eval(): 4a5. is now stricter. Addition and subtraction of arbitrary numbers are no longer allowed. (Contributed by Serhiy Storchaka in bpo-31778(26).) * *note Calendar.itermonthdates: 4a6. will now consistently raise an exception when a date falls outside of the ‘0001-01-01’ through ‘9999-12-31’ range. To support applications that cannot tolerate such exceptions, the new *note Calendar.itermonthdays3: 4a7. and *note Calendar.itermonthdays4: 4a8. can be used. The new methods return tuples and are not restricted by the range supported by *note datetime.date: 193. (Contributed by Alexander Belopolsky in bpo-28292(27).) * *note collections.ChainMap: 4a9. now preserves the order of the underlying mappings. (Contributed by Raymond Hettinger in bpo-32792(28).) * The ‘submit()’ method of *note concurrent.futures.ThreadPoolExecutor: 27a. and *note concurrent.futures.ProcessPoolExecutor: 2a4. now raises a *note RuntimeError: 2ba. if called during interpreter shutdown. (Contributed by Mark Nemec in bpo-33097(29).) * The *note configparser.ConfigParser: 4aa. constructor now uses ‘read_dict()’ to process the default values, making its behavior consistent with the rest of the parser. Non-string keys and values in the defaults dictionary are now being implicitly converted to strings. (Contributed by James Tocknell in bpo-23835(30).) * Several undocumented internal imports were removed. One example is that ‘os.errno’ is no longer available; use ‘import errno’ directly instead. Note that such undocumented internal imports may be removed any time without notice, even in micro version releases. ---------- Footnotes ---------- (1) https://bugs.python.org/issue31233 (2) https://bugs.python.org/issue33540 (3) https://bugs.python.org/issue31151 (4) https://bugs.python.org/issue33540 (5) https://bugs.python.org/issue31900 (6) https://bugs.python.org/issue24744 (7) https://bugs.python.org/issue29193 (8) https://bugs.python.org/issue29192 (9) https://bugs.python.org/issue19930 (10) https://bugs.python.org/issue21071 (11) https://bugs.python.org/issue29979 (12) https://bugs.python.org/issue30399 (13) https://bugs.python.org/issue30302 (14) https://unicode.org/reports/tr18/ (15) https://bugs.python.org/issue30349 (16) https://bugs.python.org/issue25054 (17) https://bugs.python.org/issue32308 (18) https://bugs.python.org/issue29995 (19) https://bugs.python.org/issue32121 (20) https://bugs.python.org/issue32331 (21) https://bugs.python.org/issue33169 (22) https://bugs.python.org/issue32327 (23) https://bugs.python.org/issue32662 (24) https://bugs.python.org/issue21071 (25) https://bugs.python.org/issue26510 (26) https://bugs.python.org/issue31778 (27) https://bugs.python.org/issue28292 (28) https://bugs.python.org/issue32792 (29) https://bugs.python.org/issue33097 (30) https://bugs.python.org/issue23835  File: python.info, Node: Changes in the C API<2>, Next: CPython bytecode changes<2>, Prev: Changes in the Python API<2>, Up: Porting to Python 3 7 1.2.17.3 Changes in the C API ............................. The function *note PySlice_GetIndicesEx(): 478. is considered unsafe for resizable sequences. If the slice indices are not instances of *note int: 184, but objects that implement the ‘__index__()’ method, the sequence can be resized after passing its length to ‘PySlice_GetIndicesEx()’. This can lead to returning indices out of the length of the sequence. For avoiding possible problems use new functions *note PySlice_Unpack(): 42f. and *note PySlice_AdjustIndices(): 430. (Contributed by Serhiy Storchaka in bpo-27867(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27867  File: python.info, Node: CPython bytecode changes<2>, Next: Windows-only Changes<2>, Prev: Changes in the C API<2>, Up: Porting to Python 3 7 1.2.17.4 CPython bytecode changes ................................. There are two new opcodes: *note LOAD_METHOD: 4ad. and *note CALL_METHOD: 4ae. (Contributed by Yury Selivanov and INADA Naoki in bpo-26110(1).) The ‘STORE_ANNOTATION’ opcode has been removed. (Contributed by Mark Shannon in bpo-32550(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26110 (2) https://bugs.python.org/issue32550  File: python.info, Node: Windows-only Changes<2>, Next: Other CPython implementation changes, Prev: CPython bytecode changes<2>, Up: Porting to Python 3 7 1.2.17.5 Windows-only Changes ............................. The file used to override *note sys.path: 488. is now called ‘._pth’ instead of ‘'sys.path'’. See *note Finding modules: 4b0. for more information. (Contributed by Steve Dower in bpo-28137(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28137  File: python.info, Node: Other CPython implementation changes, Prev: Windows-only Changes<2>, Up: Porting to Python 3 7 1.2.17.6 Other CPython implementation changes ............................................. In preparation for potential future changes to the public CPython runtime initialization API (see PEP 432(1) for an initial, but somewhat outdated, draft), CPython’s internal startup and configuration management logic has been significantly refactored. While these updates are intended to be entirely transparent to both embedding applications and users of the regular CPython CLI, they’re being mentioned here as the refactoring changes the internal order of various operations during interpreter startup, and hence may uncover previously latent defects, either in embedding applications, or in CPython itself. (Initially contributed by Nick Coghlan and Eric Snow as part of bpo-22257(2), and further updated by Nick, Eric, and Victor Stinner in a number of other issues). Some known details affected: * *note PySys_AddWarnOptionUnicode(): 4b2. is not currently usable by embedding applications due to the requirement to create a Unicode object prior to calling ‘Py_Initialize’. Use *note PySys_AddWarnOption(): 4b3. instead. * warnings filters added by an embedding application with *note PySys_AddWarnOption(): 4b3. should now more consistently take precedence over the default filters set by the interpreter Due to changes in the way the default warnings filters are configured, setting *note Py_BytesWarningFlag: 4b4. to a value greater than one is no longer sufficient to both emit *note BytesWarning: 4b5. messages and have them converted to exceptions. Instead, the flag must be set (to cause the warnings to be emitted in the first place), and an explicit ‘error::BytesWarning’ warnings filter added to convert them to exceptions. Due to a change in the way docstrings are handled by the compiler, the implicit ‘return None’ in a function body consisting solely of a docstring is now marked as occurring on the same line as the docstring, not on the function’s header line. The current exception state has been moved from the frame object to the co-routine. This simplified the interpreter and fixed a couple of obscure bugs caused by having swap exception state when entering or exiting a generator. (Contributed by Mark Shannon in bpo-25612(3).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0432 (2) https://bugs.python.org/issue22257 (3) https://bugs.python.org/issue25612  File: python.info, Node: Notable changes in Python 3 7 1, Next: Notable changes in Python 3 7 2, Prev: Porting to Python 3 7, Up: What’s New In Python 3 7 1.2.18 Notable changes in Python 3.7.1 -------------------------------------- Starting in 3.7.1, *note Py_Initialize(): 439. now consistently reads and respects all of the same environment settings as *note Py_Main(): 4b7. (in earlier Python versions, it respected an ill-defined subset of those environment variables, while in Python 3.7.0 it didn’t read any of them due to bpo-34247(1)). If this behavior is unwanted, set *note Py_IgnoreEnvironmentFlag: 4b8. to 1 before calling *note Py_Initialize(): 439. In 3.7.1 the C API for Context Variables *note was updated: 4b9. to use *note PyObject: 4ba. pointers. See also bpo-34762(2). In 3.7.1 the *note tokenize: 111. module now implicitly emits a ‘NEWLINE’ token when provided with input that does not have a trailing new line. This behavior now matches what the C tokenizer does internally. (Contributed by Ammar Askar in bpo-33899(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue34247 (2) https://bugs.python.org/issue34762 (3) https://bugs.python.org/issue33899  File: python.info, Node: Notable changes in Python 3 7 2, Next: Notable changes in Python 3 7 6, Prev: Notable changes in Python 3 7 1, Up: What’s New In Python 3 7 1.2.19 Notable changes in Python 3.7.2 -------------------------------------- In 3.7.2, *note venv: 125. on Windows no longer copies the original binaries, but creates redirector scripts named ‘python.exe’ and ‘pythonw.exe’ instead. This resolves a long standing issue where all virtual environments would have to be upgraded or recreated with each Python update. However, note that this release will still require recreation of virtual environments in order to get the new scripts.  File: python.info, Node: Notable changes in Python 3 7 6, Next: Notable changes in Python 3 7 10, Prev: Notable changes in Python 3 7 2, Up: What’s New In Python 3 7 1.2.20 Notable changes in Python 3.7.6 -------------------------------------- Due to significant security concerns, the `reuse_address' parameter of *note asyncio.loop.create_datagram_endpoint(): 2e7. is no longer supported. This is because of the behavior of the socket option ‘SO_REUSEADDR’ in UDP. For more details, see the documentation for ‘loop.create_datagram_endpoint()’. (Contributed by Kyle Stanley, Antoine Pitrou, and Yury Selivanov in bpo-37228(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue37228  File: python.info, Node: Notable changes in Python 3 7 10, Prev: Notable changes in Python 3 7 6, Up: What’s New In Python 3 7 1.2.21 Notable changes in Python 3.7.10 --------------------------------------- Earlier Python versions allowed using both ‘;’ and ‘&’ as query parameter separators in *note urllib.parse.parse_qs(): 2eb. and *note urllib.parse.parse_qsl(): 2ec. Due to security concerns, and to conform with newer W3C recommendations, this has been changed to allow only a single separator key, with ‘&’ as the default. This change also affects *note cgi.parse(): 2ed. and *note cgi.parse_multipart(): 2ee. as they use the affected functions internally. For more details, please see their respective documentation. (Contributed by Adam Goldschmidt, Senthil Kumaran and Ken Jin in bpo-42967(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue42967  File: python.info, Node: What’s New In Python 3 6, Next: What’s New In Python 3 5, Prev: What’s New In Python 3 7, Up: What’s New in Python 1.3 What’s New In Python 3.6 ============================ Editors: Elvis Pranskevichus <>, Yury Selivanov <> This article explains the new features in Python 3.6, compared to 3.5. Python 3.6 was released on December 23, 2016.  See the changelog(1) for a full list of changes. See also ........ PEP 494(2) - Python 3.6 Release Schedule * Menu: * Summary – Release highlights: Summary – Release highlights<2>. * New Features: New Features<3>. * Other Language Changes: Other Language Changes<3>. * New Modules: New Modules<3>. * Improved Modules: Improved Modules<3>. * Optimizations: Optimizations<3>. * Build and C API Changes: Build and C API Changes<2>. * Other Improvements:: * Deprecated: Deprecated<2>. * Removed:: * Porting to Python 3.6: Porting to Python 3 6. * Notable changes in Python 3.6.2: Notable changes in Python 3 6 2. * Notable changes in Python 3.6.4: Notable changes in Python 3 6 4. * Notable changes in Python 3.6.5: Notable changes in Python 3 6 5. * Notable changes in Python 3.6.7: Notable changes in Python 3 6 7. * Notable changes in Python 3.6.10: Notable changes in Python 3 6 10. * Notable changes in Python 3.6.13: Notable changes in Python 3 6 13. ---------- Footnotes ---------- (1) https://docs.python.org/3.6/whatsnew/changelog.html (2) https://www.python.org/dev/peps/pep-0494  File: python.info, Node: Summary – Release highlights<2>, Next: New Features<3>, Up: What’s New In Python 3 6 1.3.1 Summary – Release highlights ---------------------------------- New syntax features: * *note PEP 498: 4c1, formatted string literals. * *note PEP 515: 4c2, underscores in numeric literals. * *note PEP 526: 4c3, syntax for variable annotations. * *note PEP 525: 4c4, asynchronous generators. * *note PEP 530: 4c5.: asynchronous comprehensions. New library modules: * *note secrets: e4.: *note PEP 506 – Adding A Secrets Module To The Standard Library: 4c6. CPython implementation improvements: * The *note dict: 2fc. type has been reimplemented to use a *note more compact representation: 4c7. based on a proposal by Raymond Hettinger(1) and similar to the PyPy dict implementation(2). This resulted in dictionaries using 20% to 25% less memory when compared to Python 3.5. * Customization of class creation has been simplified with the *note new protocol: 4c8. * The class attribute definition order is *note now preserved: 4c9. * The order of elements in ‘**kwargs’ now *note corresponds to the order: 4ca. in which keyword arguments were passed to the function. * DTrace and SystemTap *note probing support: 4cb. has been added. * The new *note PYTHONMALLOC: 4cc. environment variable can now be used to debug the interpreter memory allocation and access errors. Significant improvements in the standard library: * The *note asyncio: a. module has received new features, significant usability and performance improvements, and a fair amount of bug fixes. Starting with Python 3.6 the ‘asyncio’ module is no longer provisional and its API is considered stable. * A new *note file system path protocol: 4cd. has been implemented to support *note path-like objects: 36a. All standard library functions operating on paths have been updated to work with the new protocol. * The *note datetime: 31. module has gained support for *note Local Time Disambiguation: 4ce. * The *note typing: 119. module received a number of *note improvements: 4cf. * The *note tracemalloc: 114. module has been significantly reworked and is now used to provide better output for *note ResourceWarning: 4d0. as well as provide better diagnostics for memory allocation errors. See the *note PYTHONMALLOC section: 4cc. for more information. Security improvements: * The new *note secrets: e4. module has been added to simplify the generation of cryptographically strong pseudo-random numbers suitable for managing secrets such as account authentication, tokens, and similar. * On Linux, *note os.urandom(): 4d1. now blocks until the system urandom entropy pool is initialized to increase the security. See the PEP 524(3) for the rationale. * The *note hashlib: 8d. and *note ssl: f3. modules now support OpenSSL 1.1.0. * The default settings and feature set of the *note ssl: f3. module have been improved. * The *note hashlib: 8d. module received support for the BLAKE2, SHA-3 and SHAKE hash algorithms and the *note scrypt(): 4d2. key derivation function. Windows improvements: * *note PEP 528: 4d3. and *note PEP 529: 4d4, Windows filesystem and console encoding changed to UTF-8. * The ‘py.exe’ launcher, when used interactively, no longer prefers Python 2 over Python 3 when the user doesn’t specify a version (via command line arguments or a config file). Handling of shebang lines remains unchanged - “python” refers to Python 2 in that case. * ‘python.exe’ and ‘pythonw.exe’ have been marked as long-path aware, which means that the 260 character path limit may no longer apply. See *note removing the MAX_PATH limitation: 4d5. for details. * A ‘._pth’ file can be added to force isolated mode and fully specify all search paths to avoid registry and environment lookup. See *note the documentation: 4b0. for more information. * A ‘python36.zip’ file now works as a landmark to infer *note PYTHONHOME: 4d6. See *note the documentation: 4b0. for more information. ---------- Footnotes ---------- (1) https://mail.python.org/pipermail/python-dev/2012-December/123028.html (2) https://morepypy.blogspot.com/2015/01/faster-more-memory-efficient-and-more.html (3) https://www.python.org/dev/peps/pep-0524  File: python.info, Node: New Features<3>, Next: Other Language Changes<3>, Prev: Summary – Release highlights<2>, Up: What’s New In Python 3 6 1.3.2 New Features ------------------ * Menu: * PEP 498; Formatted string literals: PEP 498 Formatted string literals. * PEP 526; Syntax for variable annotations: PEP 526 Syntax for variable annotations. * PEP 515; Underscores in Numeric Literals: PEP 515 Underscores in Numeric Literals. * PEP 525; Asynchronous Generators: PEP 525 Asynchronous Generators. * PEP 530; Asynchronous Comprehensions: PEP 530 Asynchronous Comprehensions. * PEP 487; Simpler customization of class creation: PEP 487 Simpler customization of class creation. * PEP 487; Descriptor Protocol Enhancements: PEP 487 Descriptor Protocol Enhancements. * PEP 519; Adding a file system path protocol: PEP 519 Adding a file system path protocol. * PEP 495; Local Time Disambiguation: PEP 495 Local Time Disambiguation. * PEP 529; Change Windows filesystem encoding to UTF-8: PEP 529 Change Windows filesystem encoding to UTF-8. * PEP 528; Change Windows console encoding to UTF-8: PEP 528 Change Windows console encoding to UTF-8. * PEP 520; Preserving Class Attribute Definition Order: PEP 520 Preserving Class Attribute Definition Order. * PEP 468; Preserving Keyword Argument Order: PEP 468 Preserving Keyword Argument Order. * New dict implementation:: * PEP 523; Adding a frame evaluation API to CPython: PEP 523 Adding a frame evaluation API to CPython. * PYTHONMALLOC environment variable:: * DTrace and SystemTap probing support::  File: python.info, Node: PEP 498 Formatted string literals, Next: PEP 526 Syntax for variable annotations, Up: New Features<3> 1.3.2.1 PEP 498: Formatted string literals .......................................... PEP 498(1) introduces a new kind of string literals: `f-strings', or *note formatted string literals: 15c. Formatted string literals are prefixed with ‘'f'’ and are similar to the format strings accepted by *note str.format(): 4da. They contain replacement fields surrounded by curly braces. The replacement fields are expressions, which are evaluated at run time, and then formatted using the *note format(): 4db. protocol: >>> name = "Fred" >>> f"He said his name is {name}." 'He said his name is Fred.' >>> width = 10 >>> precision = 4 >>> value = decimal.Decimal("12.34567") >>> f"result: {value:{width}.{precision}}" # nested fields 'result: 12.35' See also ........ PEP 498(2) – Literal String Interpolation. PEP written and implemented by Eric V. Smith. *note Feature documentation: 15c. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0498 (2) https://www.python.org/dev/peps/pep-0498  File: python.info, Node: PEP 526 Syntax for variable annotations, Next: PEP 515 Underscores in Numeric Literals, Prev: PEP 498 Formatted string literals, Up: New Features<3> 1.3.2.2 PEP 526: Syntax for variable annotations ................................................ PEP 484(1) introduced the standard for type annotations of function parameters, a.k.a. type hints. This PEP adds syntax to Python for annotating the types of variables including class variables and instance variables: primes: List[int] = [] captain: str # Note: no initial value! class Starship: stats: Dict[str, int] = {} Just as for function annotations, the Python interpreter does not attach any particular meaning to variable annotations and only stores them in the ‘__annotations__’ attribute of a class or module. In contrast to variable declarations in statically typed languages, the goal of annotation syntax is to provide an easy way to specify structured type metadata for third party tools and libraries via the abstract syntax tree and the ‘__annotations__’ attribute. See also ........ PEP 526(2) – Syntax for variable annotations. PEP written by Ryan Gonzalez, Philip House, Ivan Levkivskyi, Lisa Roach, and Guido van Rossum. Implemented by Ivan Levkivskyi. Tools that use or will use the new syntax: mypy(3), pytype(4), PyCharm, etc. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0526 (3) http://www.mypy-lang.org/ (4) https://github.com/google/pytype  File: python.info, Node: PEP 515 Underscores in Numeric Literals, Next: PEP 525 Asynchronous Generators, Prev: PEP 526 Syntax for variable annotations, Up: New Features<3> 1.3.2.3 PEP 515: Underscores in Numeric Literals ................................................ PEP 515(1) adds the ability to use underscores in numeric literals for improved readability. For example: >>> 1_000_000_000_000_000 1000000000000000 >>> 0x_FF_FF_FF_FF 4294967295 Single underscores are allowed between digits and after any base specifier. Leading, trailing, or multiple underscores in a row are not allowed. The *note string formatting: 4de. language also now has support for the ‘'_'’ option to signal the use of an underscore for a thousands separator for floating point presentation types and for integer presentation type ‘'d'’. For integer presentation types ‘'b'’, ‘'o'’, ‘'x'’, and ‘'X'’, underscores will be inserted every 4 digits: >>> '{:_}'.format(1000000) '1_000_000' >>> '{:_x}'.format(0xFFFFFFFF) 'ffff_ffff' See also ........ PEP 515(2) – Underscores in Numeric Literals PEP written by Georg Brandl and Serhiy Storchaka. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0515 (2) https://www.python.org/dev/peps/pep-0515  File: python.info, Node: PEP 525 Asynchronous Generators, Next: PEP 530 Asynchronous Comprehensions, Prev: PEP 515 Underscores in Numeric Literals, Up: New Features<3> 1.3.2.4 PEP 525: Asynchronous Generators ........................................ PEP 492(1) introduced support for native coroutines and ‘async’ / ‘await’ syntax to Python 3.5. A notable limitation of the Python 3.5 implementation is that it was not possible to use ‘await’ and ‘yield’ in the same function body. In Python 3.6 this restriction has been lifted, making it possible to define `asynchronous generators': async def ticker(delay, to): """Yield numbers from 0 to *to* every *delay* seconds.""" for i in range(to): yield i await asyncio.sleep(delay) The new syntax allows for faster and more concise code. See also ........ PEP 525(2) – Asynchronous Generators PEP written and implemented by Yury Selivanov. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0492 (2) https://www.python.org/dev/peps/pep-0525  File: python.info, Node: PEP 530 Asynchronous Comprehensions, Next: PEP 487 Simpler customization of class creation, Prev: PEP 525 Asynchronous Generators, Up: New Features<3> 1.3.2.5 PEP 530: Asynchronous Comprehensions ............................................ PEP 530(1) adds support for using ‘async for’ in list, set, dict comprehensions and generator expressions: result = [i async for i in aiter() if i % 2] Additionally, ‘await’ expressions are supported in all kinds of comprehensions: result = [await fun() for fun in funcs if await condition()] See also ........ PEP 530(2) – Asynchronous Comprehensions PEP written and implemented by Yury Selivanov. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0530 (2) https://www.python.org/dev/peps/pep-0530  File: python.info, Node: PEP 487 Simpler customization of class creation, Next: PEP 487 Descriptor Protocol Enhancements, Prev: PEP 530 Asynchronous Comprehensions, Up: New Features<3> 1.3.2.6 PEP 487: Simpler customization of class creation ........................................................ It is now possible to customize subclass creation without using a metaclass. The new ‘__init_subclass__’ classmethod will be called on the base class whenever a new subclass is created: class PluginBase: subclasses = [] def __init_subclass__(cls, **kwargs): super().__init_subclass__(**kwargs) cls.subclasses.append(cls) class Plugin1(PluginBase): pass class Plugin2(PluginBase): pass In order to allow zero-argument *note super(): 4e2. calls to work correctly from *note __init_subclass__(): 4e3. implementations, custom metaclasses must ensure that the new ‘__classcell__’ namespace entry is propagated to ‘type.__new__’ (as described in *note Creating the class object: 4e4.). See also ........ PEP 487(1) – Simpler customization of class creation PEP written and implemented by Martin Teichmann. *note Feature documentation: 4e5. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0487  File: python.info, Node: PEP 487 Descriptor Protocol Enhancements, Next: PEP 519 Adding a file system path protocol, Prev: PEP 487 Simpler customization of class creation, Up: New Features<3> 1.3.2.7 PEP 487: Descriptor Protocol Enhancements ................................................. PEP 487(1) extends the descriptor protocol to include the new optional *note __set_name__(): 4e8. method. Whenever a new class is defined, the new method will be called on all descriptors included in the definition, providing them with a reference to the class being defined and the name given to the descriptor within the class namespace. In other words, instances of descriptors can now know the attribute name of the descriptor in the owner class: class IntField: def __get__(self, instance, owner): return instance.__dict__[self.name] def __set__(self, instance, value): if not isinstance(value, int): raise ValueError(f'expecting integer in {self.name}') instance.__dict__[self.name] = value # this is the new initializer: def __set_name__(self, owner, name): self.name = name class Model: int_field = IntField() See also ........ PEP 487(2) – Simpler customization of class creation PEP written and implemented by Martin Teichmann. *note Feature documentation: 4e9. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0487 (2) https://www.python.org/dev/peps/pep-0487  File: python.info, Node: PEP 519 Adding a file system path protocol, Next: PEP 495 Local Time Disambiguation, Prev: PEP 487 Descriptor Protocol Enhancements, Up: New Features<3> 1.3.2.8 PEP 519: Adding a file system path protocol ................................................... File system paths have historically been represented as *note str: 330. or *note bytes: 331. objects. This has led to people who write code which operate on file system paths to assume that such objects are only one of those two types (an *note int: 184. representing a file descriptor does not count as that is not a file path). Unfortunately that assumption prevents alternative object representations of file system paths like *note pathlib: c8. from working with pre-existing code, including Python’s standard library. To fix this situation, a new interface represented by *note os.PathLike: 4eb. has been defined. By implementing the *note __fspath__(): 4ec. method, an object signals that it represents a path. An object can then provide a low-level representation of a file system path as a *note str: 330. or *note bytes: 331. object. This means an object is considered *note path-like: 36a. if it implements *note os.PathLike: 4eb. or is a *note str: 330. or *note bytes: 331. object which represents a file system path. Code can use *note os.fspath(): 4ed, *note os.fsdecode(): 4ee, or *note os.fsencode(): 4ef. to explicitly get a *note str: 330. and/or *note bytes: 331. representation of a path-like object. The built-in *note open(): 4f0. function has been updated to accept *note os.PathLike: 4eb. objects, as have all relevant functions in the *note os: c4. and *note os.path: c5. modules, and most other functions and classes in the standard library. The *note os.DirEntry: 4f1. class and relevant classes in *note pathlib: c8. have also been updated to implement *note os.PathLike: 4eb. The hope is that updating the fundamental functions for operating on file system paths will lead to third-party code to implicitly support all *note path-like objects: 36a. without any code changes, or at least very minimal ones (e.g. calling *note os.fspath(): 4ed. at the beginning of code before operating on a path-like object). Here are some examples of how the new interface allows for *note pathlib.Path: 201. to be used more easily and transparently with pre-existing code: >>> import pathlib >>> with open(pathlib.Path("README")) as f: ... contents = f.read() ... >>> import os.path >>> os.path.splitext(pathlib.Path("some_file.txt")) ('some_file', '.txt') >>> os.path.join("/a/b", pathlib.Path("c")) '/a/b/c' >>> import os >>> os.fspath(pathlib.Path("some_file.txt")) 'some_file.txt' (Implemented by Brett Cannon, Ethan Furman, Dusty Phillips, and Jelle Zijlstra.) See also ........ PEP 519(1) – Adding a file system path protocol PEP written by Brett Cannon and Koos Zevenhoven. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0519  File: python.info, Node: PEP 495 Local Time Disambiguation, Next: PEP 529 Change Windows filesystem encoding to UTF-8, Prev: PEP 519 Adding a file system path protocol, Up: New Features<3> 1.3.2.9 PEP 495: Local Time Disambiguation .......................................... In most world locations, there have been and will be times when local clocks are moved back. In those times, intervals are introduced in which local clocks show the same time twice in the same day. In these situations, the information displayed on a local clock (or stored in a Python datetime instance) is insufficient to identify a particular moment in time. PEP 495(1) adds the new `fold' attribute to instances of *note datetime.datetime: 194. and *note datetime.time: 4f3. classes to differentiate between two moments in time for which local times are the same: >>> u0 = datetime(2016, 11, 6, 4, tzinfo=timezone.utc) >>> for i in range(4): ... u = u0 + i*HOUR ... t = u.astimezone(Eastern) ... print(u.time(), 'UTC =', t.time(), t.tzname(), t.fold) ... 04:00:00 UTC = 00:00:00 EDT 0 05:00:00 UTC = 01:00:00 EDT 0 06:00:00 UTC = 01:00:00 EST 1 07:00:00 UTC = 02:00:00 EST 0 The values of the *note fold: 4f4. attribute have the value ‘0’ for all instances except those that represent the second (chronologically) moment in time in an ambiguous case. See also ........ PEP 495(2) – Local Time Disambiguation PEP written by Alexander Belopolsky and Tim Peters, implementation by Alexander Belopolsky. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0495 (2) https://www.python.org/dev/peps/pep-0495  File: python.info, Node: PEP 529 Change Windows filesystem encoding to UTF-8, Next: PEP 528 Change Windows console encoding to UTF-8, Prev: PEP 495 Local Time Disambiguation, Up: New Features<3> 1.3.2.10 PEP 529: Change Windows filesystem encoding to UTF-8 ............................................................. Representing filesystem paths is best performed with str (Unicode) rather than bytes. However, there are some situations where using bytes is sufficient and correct. Prior to Python 3.6, data loss could result when using bytes paths on Windows. With this change, using bytes to represent paths is now supported on Windows, provided those bytes are encoded with the encoding returned by *note sys.getfilesystemencoding(): 4f6, which now defaults to ‘'utf-8'’. Applications that do not use str to represent paths should use *note os.fsencode(): 4ef. and *note os.fsdecode(): 4ee. to ensure their bytes are correctly encoded. To revert to the previous behaviour, set *note PYTHONLEGACYWINDOWSFSENCODING: 4f7. or call *note sys._enablelegacywindowsfsencoding(): 4f8. See PEP 529(1) for more information and discussion of code modifications that may be required. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0529  File: python.info, Node: PEP 528 Change Windows console encoding to UTF-8, Next: PEP 520 Preserving Class Attribute Definition Order, Prev: PEP 529 Change Windows filesystem encoding to UTF-8, Up: New Features<3> 1.3.2.11 PEP 528: Change Windows console encoding to UTF-8 .......................................................... The default console on Windows will now accept all Unicode characters and provide correctly read str objects to Python code. ‘sys.stdin’, ‘sys.stdout’ and ‘sys.stderr’ now default to utf-8 encoding. This change only applies when using an interactive console, and not when redirecting files or pipes. To revert to the previous behaviour for interactive console use, set *note PYTHONLEGACYWINDOWSSTDIO: 4fa. See also ........ PEP 528(1) – Change Windows console encoding to UTF-8 PEP written and implemented by Steve Dower. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0528  File: python.info, Node: PEP 520 Preserving Class Attribute Definition Order, Next: PEP 468 Preserving Keyword Argument Order, Prev: PEP 528 Change Windows console encoding to UTF-8, Up: New Features<3> 1.3.2.12 PEP 520: Preserving Class Attribute Definition Order ............................................................. Attributes in a class definition body have a natural ordering: the same order in which the names appear in the source. This order is now preserved in the new class’s *note __dict__: 4fc. attribute. Also, the effective default class `execution' namespace (returned from *note type.__prepare__(): 4fd.) is now an insertion-order-preserving mapping. See also ........ PEP 520(1) – Preserving Class Attribute Definition Order PEP written and implemented by Eric Snow. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0520  File: python.info, Node: PEP 468 Preserving Keyword Argument Order, Next: New dict implementation, Prev: PEP 520 Preserving Class Attribute Definition Order, Up: New Features<3> 1.3.2.13 PEP 468: Preserving Keyword Argument Order ................................................... ‘**kwargs’ in a function signature is now guaranteed to be an insertion-order-preserving mapping. See also ........ PEP 468(1) – Preserving Keyword Argument Order PEP written and implemented by Eric Snow. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0468  File: python.info, Node: New dict implementation, Next: PEP 523 Adding a frame evaluation API to CPython, Prev: PEP 468 Preserving Keyword Argument Order, Up: New Features<3> 1.3.2.14 New dict implementation ................................ The *note dict: 2fc. type now uses a “compact” representation based on a proposal by Raymond Hettinger(1) which was first implemented by PyPy(2). The memory usage of the new *note dict(): 1b8. is between 20% and 25% smaller compared to Python 3.5. The order-preserving aspect of this new implementation is considered an implementation detail and should not be relied upon (this may change in the future, but it is desired to have this new dict implementation in the language for a few releases before changing the language spec to mandate order-preserving semantics for all current and future Python implementations; this also helps preserve backwards-compatibility with older versions of the language where random iteration order is still in effect, e.g. Python 3.5). (Contributed by INADA Naoki in bpo-27350(3). Idea originally suggested by Raymond Hettinger(4).) ---------- Footnotes ---------- (1) https://mail.python.org/pipermail/python-dev/2012-December/123028.html (2) https://morepypy.blogspot.com/2015/01/faster-more-memory-efficient-and-more.html (3) https://bugs.python.org/issue27350 (4) https://mail.python.org/pipermail/python-dev/2012-December/123028.html  File: python.info, Node: PEP 523 Adding a frame evaluation API to CPython, Next: PYTHONMALLOC environment variable, Prev: New dict implementation, Up: New Features<3> 1.3.2.15 PEP 523: Adding a frame evaluation API to CPython .......................................................... While Python provides extensive support to customize how code executes, one place it has not done so is in the evaluation of frame objects. If you wanted some way to intercept frame evaluation in Python there really wasn’t any way without directly manipulating function pointers for defined functions. PEP 523(1) changes this by providing an API to make frame evaluation pluggable at the C level. This will allow for tools such as debuggers and JITs to intercept frame evaluation before the execution of Python code begins. This enables the use of alternative evaluation implementations for Python code, tracking frame evaluation, etc. This API is not part of the limited C API and is marked as private to signal that usage of this API is expected to be limited and only applicable to very select, low-level use-cases. Semantics of the API will change with Python as necessary. See also ........ PEP 523(2) – Adding a frame evaluation API to CPython PEP written by Brett Cannon and Dino Viehland. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0523 (2) https://www.python.org/dev/peps/pep-0523  File: python.info, Node: PYTHONMALLOC environment variable, Next: DTrace and SystemTap probing support, Prev: PEP 523 Adding a frame evaluation API to CPython, Up: New Features<3> 1.3.2.16 PYTHONMALLOC environment variable .......................................... The new *note PYTHONMALLOC: 503. environment variable allows setting the Python memory allocators and installing debug hooks. It is now possible to install debug hooks on Python memory allocators on Python compiled in release mode using ‘PYTHONMALLOC=debug’. Effects of debug hooks: * Newly allocated memory is filled with the byte ‘0xCB’ * Freed memory is filled with the byte ‘0xDB’ * Detect violations of the Python memory allocator API. For example, *note PyObject_Free(): 504. called on a memory block allocated by *note PyMem_Malloc(): 505. * Detect writes before the start of a buffer (buffer underflows) * Detect writes after the end of a buffer (buffer overflows) * Check that the *note GIL: 506. is held when allocator functions of *note PYMEM_DOMAIN_OBJ: 507. (ex: *note PyObject_Malloc(): 508.) and *note PYMEM_DOMAIN_MEM: 509. (ex: *note PyMem_Malloc(): 505.) domains are called. Checking if the GIL is held is also a new feature of Python 3.6. See the *note PyMem_SetupDebugHooks(): 50a. function for debug hooks on Python memory allocators. It is now also possible to force the usage of the ‘malloc()’ allocator of the C library for all Python memory allocations using ‘PYTHONMALLOC=malloc’. This is helpful when using external memory debuggers like Valgrind on a Python compiled in release mode. On error, the debug hooks on Python memory allocators now use the *note tracemalloc: 114. module to get the traceback where a memory block was allocated. Example of fatal error on buffer overflow using ‘python3.6 -X tracemalloc=5’ (store 5 frames in traces): Debug memory block at address p=0x7fbcd41666f8: API 'o' 4 bytes originally requested The 7 pad bytes at p-7 are FORBIDDENBYTE, as expected. The 8 pad bytes at tail=0x7fbcd41666fc are not all FORBIDDENBYTE (0xfb): at tail+0: 0x02 *** OUCH at tail+1: 0xfb at tail+2: 0xfb at tail+3: 0xfb at tail+4: 0xfb at tail+5: 0xfb at tail+6: 0xfb at tail+7: 0xfb The block was made by call #1233329 to debug malloc/realloc. Data at p: 1a 2b 30 00 Memory block allocated at (most recent call first): File "test/test_bytes.py", line 323 File "unittest/case.py", line 600 File "unittest/case.py", line 648 File "unittest/suite.py", line 122 File "unittest/suite.py", line 84 Fatal Python error: bad trailing pad byte Current thread 0x00007fbcdbd32700 (most recent call first): File "test/test_bytes.py", line 323 in test_hex File "unittest/case.py", line 600 in run File "unittest/case.py", line 648 in __call__ File "unittest/suite.py", line 122 in run File "unittest/suite.py", line 84 in __call__ File "unittest/suite.py", line 122 in run File "unittest/suite.py", line 84 in __call__ ... (Contributed by Victor Stinner in bpo-26516(1) and bpo-26564(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26516 (2) https://bugs.python.org/issue26564  File: python.info, Node: DTrace and SystemTap probing support, Prev: PYTHONMALLOC environment variable, Up: New Features<3> 1.3.2.17 DTrace and SystemTap probing support ............................................. Python can now be built ‘--with-dtrace’ which enables static markers for the following events in the interpreter: * function call/return * garbage collection started/finished * line of code executed. This can be used to instrument running interpreters in production, without the need to recompile specific debug builds or providing application-specific profiling/debugging code. More details in *note Instrumenting CPython with DTrace and SystemTap: 50c. The current implementation is tested on Linux and macOS. Additional markers may be added in the future. (Contributed by Łukasz Langa in bpo-21590(1), based on patches by Jesús Cea Avión, David Malcolm, and Nikhil Benesch.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21590  File: python.info, Node: Other Language Changes<3>, Next: New Modules<3>, Prev: New Features<3>, Up: What’s New In Python 3 6 1.3.3 Other Language Changes ---------------------------- Some smaller changes made to the core Python language are: * A ‘global’ or ‘nonlocal’ statement must now textually appear before the first use of the affected name in the same scope. Previously this was a *note SyntaxWarning: 191. * It is now possible to set a *note special method: 50e. to ‘None’ to indicate that the corresponding operation is not available. For example, if a class sets *note __iter__(): 50f. to ‘None’, the class is not iterable. (Contributed by Andrew Barnert and Ivan Levkivskyi in bpo-25958(1).) * Long sequences of repeated traceback lines are now abbreviated as ‘"[Previous line repeated {count} more times]"’ (see *note traceback: 510. for an example). (Contributed by Emanuel Barry in bpo-26823(2).) * Import now raises the new exception *note ModuleNotFoundError: 39a. (subclass of *note ImportError: 334.) when it cannot find a module. Code that currently checks for ImportError (in try-except) will still work. (Contributed by Eric Snow in bpo-15767(3).) * Class methods relying on zero-argument ‘super()’ will now work correctly when called from metaclass methods during class creation. (Contributed by Martin Teichmann in bpo-23722(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25958 (2) https://bugs.python.org/issue26823 (3) https://bugs.python.org/issue15767 (4) https://bugs.python.org/issue23722  File: python.info, Node: New Modules<3>, Next: Improved Modules<3>, Prev: Other Language Changes<3>, Up: What’s New In Python 3 6 1.3.4 New Modules ----------------- * Menu: * secrets::  File: python.info, Node: secrets, Up: New Modules<3> 1.3.4.1 secrets ............... The main purpose of the new *note secrets: e4. module is to provide an obvious way to reliably generate cryptographically strong pseudo-random values suitable for managing secrets, such as account authentication, tokens, and similar. Warning: Note that the pseudo-random generators in the *note random: dc. module should `NOT' be used for security purposes. Use *note secrets: e4. on Python 3.6+ and *note os.urandom(): 4d1. on Python 3.5 and earlier. See also ........ PEP 506(1) – Adding A Secrets Module To The Standard Library PEP written and implemented by Steven D’Aprano. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0506  File: python.info, Node: Improved Modules<3>, Next: Optimizations<3>, Prev: New Modules<3>, Up: What’s New In Python 3 6 1.3.5 Improved Modules ---------------------- * Menu: * array:: * ast: ast<2>. * asyncio: asyncio<4>. * binascii: binascii<2>. * cmath:: * collections: collections<4>. * concurrent.futures: concurrent futures<2>. * contextlib: contextlib<2>. * datetime: datetime<3>. * decimal: decimal<2>. * distutils: distutils<2>. * email:: * encodings:: * enum: enum<3>. * faulthandler:: * fileinput:: * hashlib:: * http.client: http client<2>. * idlelib and IDLE: idlelib and IDLE<2>. * importlib: importlib<3>. * inspect: inspect<2>. * json:: * logging: logging<3>. * math: math<3>. * multiprocessing: multiprocessing<3>. * os: os<3>. * pathlib: pathlib<3>. * pdb: pdb<2>. * pickle: pickle<2>. * pickletools:: * pydoc: pydoc<2>. * random:: * re: re<2>. * readline:: * rlcompleter:: * shlex: shlex<2>. * site:: * sqlite3: sqlite3<2>. * socket: socket<4>. * socketserver: socketserver<2>. * ssl: ssl<4>. * statistics: statistics<2>. * struct:: * subprocess: subprocess<2>. * sys: sys<4>. * telnetlib:: * time: time<3>. * timeit:: * tkinter: tkinter<3>. * traceback:: * tracemalloc: tracemalloc<2>. * typing: typing<2>. * unicodedata: unicodedata<3>. * unittest.mock: unittest mock<2>. * urllib.request: urllib request. * urllib.robotparser: urllib robotparser. * venv: venv<2>. * warnings: warnings<2>. * winreg:: * winsound:: * xmlrpc.client: xmlrpc client. * zipfile: zipfile<2>. * zlib::  File: python.info, Node: array, Next: ast<2>, Up: Improved Modules<3> 1.3.5.1 array ............. Exhausted iterators of *note array.array: 451. will now stay exhausted even if the iterated array is extended. This is consistent with the behavior of other mutable sequences. Contributed by Serhiy Storchaka in bpo-26492(1). ---------- Footnotes ---------- (1) https://bugs.python.org/issue26492  File: python.info, Node: ast<2>, Next: asyncio<4>, Prev: array, Up: Improved Modules<3> 1.3.5.2 ast ........... The new ‘ast.Constant’ AST node has been added. It can be used by external AST optimizers for the purposes of constant folding. Contributed by Victor Stinner in bpo-26146(1). ---------- Footnotes ---------- (1) https://bugs.python.org/issue26146  File: python.info, Node: asyncio<4>, Next: binascii<2>, Prev: ast<2>, Up: Improved Modules<3> 1.3.5.3 asyncio ............... Starting with Python 3.6 the ‘asyncio’ module is no longer provisional and its API is considered stable. Notable changes in the *note asyncio: a. module since Python 3.5.0 (all backported to 3.5.x due to the provisional status): * The *note get_event_loop(): 355. function has been changed to always return the currently running loop when called from coroutines and callbacks. (Contributed by Yury Selivanov in bpo-28613(1).) * The *note ensure_future(): 517. function and all functions that use it, such as *note loop.run_until_complete(): 518, now accept all kinds of *note awaitable objects: 519. (Contributed by Yury Selivanov.) * New *note run_coroutine_threadsafe(): 51a. function to submit coroutines to event loops from other threads. (Contributed by Vincent Michel.) * New *note Transport.is_closing(): 51b. method to check if the transport is closing or closed. (Contributed by Yury Selivanov.) * The *note loop.create_server(): 35d. method can now accept a list of hosts. (Contributed by Yann Sionneau.) * New *note loop.create_future(): 51c. method to create Future objects. This allows alternative event loop implementations, such as uvloop(2), to provide a faster *note asyncio.Future: 443. implementation. (Contributed by Yury Selivanov in bpo-27041(3).) * New *note loop.get_exception_handler(): 51d. method to get the current exception handler. (Contributed by Yury Selivanov in bpo-27040(4).) * New *note StreamReader.readuntil(): 51e. method to read data from the stream until a separator bytes sequence appears. (Contributed by Mark Korenberg.) * The performance of *note StreamReader.readexactly(): 51f. has been improved. (Contributed by Mark Korenberg in bpo-28370(5).) * The *note loop.getaddrinfo(): 4a1. method is optimized to avoid calling the system ‘getaddrinfo’ function if the address is already resolved. (Contributed by A. Jesse Jiryu Davis.) * The *note loop.stop(): 520. method has been changed to stop the loop immediately after the current iteration. Any new callbacks scheduled as a result of the last iteration will be discarded. (Contributed by Guido van Rossum in bpo-25593(6).) * ‘Future.set_exception’ will now raise *note TypeError: 192. when passed an instance of the *note StopIteration: 486. exception. (Contributed by Chris Angelico in bpo-26221(7).) * New *note loop.connect_accepted_socket(): 365. method to be used by servers that accept connections outside of asyncio, but that use asyncio to handle them. (Contributed by Jim Fulton in bpo-27392(8).) * ‘TCP_NODELAY’ flag is now set for all TCP transports by default. (Contributed by Yury Selivanov in bpo-27456(9).) * New *note loop.shutdown_asyncgens(): 521. to properly close pending asynchronous generators before closing the loop. (Contributed by Yury Selivanov in bpo-28003(10).) * *note Future: 443. and *note Task: 1ad. classes now have an optimized C implementation which makes asyncio code up to 30% faster. (Contributed by Yury Selivanov and INADA Naoki in bpo-26081(11) and bpo-28544(12).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28613 (2) https://github.com/MagicStack/uvloop (3) https://bugs.python.org/issue27041 (4) https://bugs.python.org/issue27040 (5) https://bugs.python.org/issue28370 (6) https://bugs.python.org/issue25593 (7) https://bugs.python.org/issue26221 (8) https://bugs.python.org/issue27392 (9) https://bugs.python.org/issue27456 (10) https://bugs.python.org/issue28003 (11) https://bugs.python.org/issue26081 (12) https://bugs.python.org/issue28544  File: python.info, Node: binascii<2>, Next: cmath, Prev: asyncio<4>, Up: Improved Modules<3> 1.3.5.4 binascii ................ The *note b2a_base64(): 523. function now accepts an optional `newline' keyword argument to control whether the newline character is appended to the return value. (Contributed by Victor Stinner in bpo-25357(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25357  File: python.info, Node: cmath, Next: collections<4>, Prev: binascii<2>, Up: Improved Modules<3> 1.3.5.5 cmath ............. The new *note cmath.tau: 525. (`τ') constant has been added. (Contributed by Lisa Roach in bpo-12345(1), see PEP 628(2) for details.) New constants: *note cmath.inf: 526. and *note cmath.nan: 527. to match *note math.inf: 528. and *note math.nan: 529, and also *note cmath.infj: 52a. and *note cmath.nanj: 52b. to match the format used by complex repr. (Contributed by Mark Dickinson in bpo-23229(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12345 (2) https://www.python.org/dev/peps/pep-0628 (3) https://bugs.python.org/issue23229  File: python.info, Node: collections<4>, Next: concurrent futures<2>, Prev: cmath, Up: Improved Modules<3> 1.3.5.6 collections ................... The new *note Collection: 52d. abstract base class has been added to represent sized iterable container classes. (Contributed by Ivan Levkivskyi, docs by Neil Girdhar in bpo-27598(1).) The new *note Reversible: 52e. abstract base class represents iterable classes that also provide the *note __reversed__(): 52f. method. (Contributed by Ivan Levkivskyi in bpo-25987(2).) The new *note AsyncGenerator: 530. abstract base class represents asynchronous generators. (Contributed by Yury Selivanov in bpo-28720(3).) The *note namedtuple(): 1b7. function now accepts an optional keyword argument `module', which, when specified, is used for the ‘__module__’ attribute of the returned named tuple class. (Contributed by Raymond Hettinger in bpo-17941(4).) The `verbose' and `rename' arguments for *note namedtuple(): 1b7. are now keyword-only. (Contributed by Raymond Hettinger in bpo-25628(5).) Recursive *note collections.deque: 531. instances can now be pickled. (Contributed by Serhiy Storchaka in bpo-26482(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27598 (2) https://bugs.python.org/issue25987 (3) https://bugs.python.org/issue28720 (4) https://bugs.python.org/issue17941 (5) https://bugs.python.org/issue25628 (6) https://bugs.python.org/issue26482  File: python.info, Node: concurrent futures<2>, Next: contextlib<2>, Prev: collections<4>, Up: Improved Modules<3> 1.3.5.7 concurrent.futures .......................... The *note ThreadPoolExecutor: 27a. class constructor now accepts an optional `thread_name_prefix' argument to make it possible to customize the names of the threads created by the pool. (Contributed by Gregory P. Smith in bpo-27664(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27664  File: python.info, Node: contextlib<2>, Next: datetime<3>, Prev: concurrent futures<2>, Up: Improved Modules<3> 1.3.5.8 contextlib .................. The *note contextlib.AbstractContextManager: 534. class has been added to provide an abstract base class for context managers. It provides a sensible default implementation for ‘__enter__()’ which returns ‘self’ and leaves ‘__exit__()’ an abstract method. A matching class has been added to the *note typing: 119. module as *note typing.ContextManager: 535. (Contributed by Brett Cannon in bpo-25609(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25609  File: python.info, Node: datetime<3>, Next: decimal<2>, Prev: contextlib<2>, Up: Improved Modules<3> 1.3.5.9 datetime ................ The *note datetime: 194. and *note time: 4f3. classes have the new ‘fold’ attribute used to disambiguate local time when necessary. Many functions in the *note datetime: 31. have been updated to support local time disambiguation. See *note Local Time Disambiguation: 4ce. section for more information. (Contributed by Alexander Belopolsky in bpo-24773(1).) The *note datetime.strftime(): 537. and *note date.strftime(): 538. methods now support ISO 8601 date directives ‘%G’, ‘%u’ and ‘%V’. (Contributed by Ashley Anderson in bpo-12006(2).) The *note datetime.isoformat(): 37f. function now accepts an optional `timespec' argument that specifies the number of additional components of the time value to include. (Contributed by Alessandro Cucci and Alexander Belopolsky in bpo-19475(3).) The *note datetime.combine(): 539. now accepts an optional `tzinfo' argument. (Contributed by Alexander Belopolsky in bpo-27661(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24773 (2) https://bugs.python.org/issue12006 (3) https://bugs.python.org/issue19475 (4) https://bugs.python.org/issue27661  File: python.info, Node: decimal<2>, Next: distutils<2>, Prev: datetime<3>, Up: Improved Modules<3> 1.3.5.10 decimal ................ New *note Decimal.as_integer_ratio(): 53b. method that returns a pair ‘(n, d)’ of integers that represent the given *note Decimal: 188. instance as a fraction, in lowest terms and with a positive denominator: >>> Decimal('-3.14').as_integer_ratio() (-157, 50) (Contributed by Stefan Krah amd Mark Dickinson in bpo-25928(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25928  File: python.info, Node: distutils<2>, Next: email, Prev: decimal<2>, Up: Improved Modules<3> 1.3.5.11 distutils .................. The ‘default_format’ attribute has been removed from ‘distutils.command.sdist.sdist’ and the ‘formats’ attribute defaults to ‘['gztar']’. Although not anticipated, any code relying on the presence of ‘default_format’ may need to be adapted. See bpo-27819(1) for more details. ---------- Footnotes ---------- (1) https://bugs.python.org/issue27819  File: python.info, Node: email, Next: encodings, Prev: distutils<2>, Up: Improved Modules<3> 1.3.5.12 email .............. The new email API, enabled via the `policy' keyword to various constructors, is no longer provisional. The *note email: 69. documentation has been reorganized and rewritten to focus on the new API, while retaining the old documentation for the legacy API. (Contributed by R. David Murray in bpo-24277(1).) The *note email.mime: 73. classes now all accept an optional `policy' keyword. (Contributed by Berker Peksag in bpo-27331(2).) The *note DecodedGenerator: 53e. now supports the `policy' keyword. There is a new *note policy: 75. attribute, *note message_factory: 53f, that controls what class is used by default when the parser creates new message objects. For the *note email.policy.compat32: 540. policy this is *note Message: 541, for the new policies it is *note EmailMessage: 542. (Contributed by R. David Murray in bpo-20476(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24277 (2) https://bugs.python.org/issue27331 (3) https://bugs.python.org/issue20476  File: python.info, Node: encodings, Next: enum<3>, Prev: email, Up: Improved Modules<3> 1.3.5.13 encodings .................. On Windows, added the ‘'oem'’ encoding to use ‘CP_OEMCP’, and the ‘'ansi'’ alias for the existing ‘'mbcs'’ encoding, which uses the ‘CP_ACP’ code page. (Contributed by Steve Dower in bpo-27959(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27959  File: python.info, Node: enum<3>, Next: faulthandler, Prev: encodings, Up: Improved Modules<3> 1.3.5.14 enum ............. Two new enumeration base classes have been added to the *note enum: 7b. module: *note Flag: 545. and ‘IntFlags’. Both are used to define constants that can be combined using the bitwise operators. (Contributed by Ethan Furman in bpo-23591(1).) Many standard library modules have been updated to use the ‘IntFlags’ class for their constants. The new *note enum.auto: 546. value can be used to assign values to enum members automatically: >>> from enum import Enum, auto >>> class Color(Enum): ... red = auto() ... blue = auto() ... green = auto() ... >>> list(Color) [, , ] ---------- Footnotes ---------- (1) https://bugs.python.org/issue23591  File: python.info, Node: faulthandler, Next: fileinput, Prev: enum<3>, Up: Improved Modules<3> 1.3.5.15 faulthandler ..................... On Windows, the *note faulthandler: 7d. module now installs a handler for Windows exceptions: see *note faulthandler.enable(): 548. (Contributed by Victor Stinner in bpo-23848(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23848  File: python.info, Node: fileinput, Next: hashlib, Prev: faulthandler, Up: Improved Modules<3> 1.3.5.16 fileinput .................. *note hook_encoded(): 54a. now supports the `errors' argument. (Contributed by Joseph Hackman in bpo-25788(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25788  File: python.info, Node: hashlib, Next: http client<2>, Prev: fileinput, Up: Improved Modules<3> 1.3.5.17 hashlib ................ *note hashlib: 8d. supports OpenSSL 1.1.0. The minimum recommend version is 1.0.2. (Contributed by Christian Heimes in bpo-26470(1).) BLAKE2 hash functions were added to the module. *note blake2b(): 54c. and *note blake2s(): 54d. are always available and support the full feature set of BLAKE2. (Contributed by Christian Heimes in bpo-26798(2) based on code by Dmitry Chestnykh and Samuel Neves. Documentation written by Dmitry Chestnykh.) The SHA-3 hash functions ‘sha3_224()’, ‘sha3_256()’, ‘sha3_384()’, ‘sha3_512()’, and SHAKE hash functions ‘shake_128()’ and ‘shake_256()’ were added. (Contributed by Christian Heimes in bpo-16113(3). Keccak Code Package by Guido Bertoni, Joan Daemen, Michaël Peeters, Gilles Van Assche, and Ronny Van Keer.) The password-based key derivation function *note scrypt(): 4d2. is now available with OpenSSL 1.1.0 and newer. (Contributed by Christian Heimes in bpo-27928(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26470 (2) https://bugs.python.org/issue26798 (3) https://bugs.python.org/issue16113 (4) https://bugs.python.org/issue27928  File: python.info, Node: http client<2>, Next: idlelib and IDLE<2>, Prev: hashlib, Up: Improved Modules<3> 1.3.5.18 http.client .................... *note HTTPConnection.request(): 54f. and *note endheaders(): 550. both now support chunked encoding request bodies. (Contributed by Demian Brecht and Rolf Krahl in bpo-12319(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12319  File: python.info, Node: idlelib and IDLE<2>, Next: importlib<3>, Prev: http client<2>, Up: Improved Modules<3> 1.3.5.19 idlelib and IDLE ......................... The idlelib package is being modernized and refactored to make IDLE look and work better and to make the code easier to understand, test, and improve. Part of making IDLE look better, especially on Linux and Mac, is using ttk widgets, mostly in the dialogs. As a result, IDLE no longer runs with tcl/tk 8.4. It now requires tcl/tk 8.5 or 8.6. We recommend running the latest release of either. ‘Modernizing’ includes renaming and consolidation of idlelib modules. The renaming of files with partial uppercase names is similar to the renaming of, for instance, Tkinter and TkFont to tkinter and tkinter.font in 3.0. As a result, imports of idlelib files that worked in 3.5 will usually not work in 3.6. At least a module name change will be needed (see idlelib/README.txt), sometimes more. (Name changes contributed by Al Swiegart and Terry Reedy in bpo-24225(1). Most idlelib patches since have been and will be part of the process.) In compensation, the eventual result with be that some idlelib classes will be easier to use, with better APIs and docstrings explaining them. Additional useful information will be added to idlelib when available. New in 3.6.2: Multiple fixes for autocompletion. (Contributed by Louie Lu in bpo-15786(2).) New in 3.6.3: Module Browser (on the File menu, formerly called Class Browser), now displays nested functions and classes in addition to top-level functions and classes. (Contributed by Guilherme Polo, Cheryl Sabella, and Terry Jan Reedy in bpo-1612262(3).) The IDLE features formerly implemented as extensions have been reimplemented as normal features. Their settings have been moved from the Extensions tab to other dialog tabs. (Contributed by Charles Wohlganger and Terry Jan Reedy in bpo-27099(4).) The Settings dialog (Options, Configure IDLE) has been partly rewritten to improve both appearance and function. (Contributed by Cheryl Sabella and Terry Jan Reedy in multiple issues.) New in 3.6.4: The font sample now includes a selection of non-Latin characters so that users can better see the effect of selecting a particular font. (Contributed by Terry Jan Reedy in bpo-13802(5).) The sample can be edited to include other characters. (Contributed by Serhiy Storchaka in bpo-31860(6).) New in 3.6.6: Editor code context option revised. Box displays all context lines up to maxlines. Clicking on a context line jumps the editor to that line. Context colors for custom themes is added to Highlights tab of Settings dialog. (Contributed by Cheryl Sabella and Terry Jan Reedy in bpo-33642(7), bpo-33768(8), and bpo-33679(9).) On Windows, a new API call tells Windows that tk scales for DPI. On Windows 8.1+ or 10, with DPI compatibility properties of the Python binary unchanged, and a monitor resolution greater than 96 DPI, this should make text and lines sharper. It should otherwise have no effect. (Contributed by Terry Jan Reedy in bpo-33656(10).) New in 3.6.7: Output over N lines (50 by default) is squeezed down to a button. N can be changed in the PyShell section of the General page of the Settings dialog. Fewer, but possibly extra long, lines can be squeezed by right clicking on the output. Squeezed output can be expanded in place by double-clicking the button or into the clipboard or a separate window by right-clicking the button. (Contributed by Tal Einat in bpo-1529353(11).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24225 (2) https://bugs.python.org/issue15786 (3) https://bugs.python.org/issue1612262 (4) https://bugs.python.org/issue27099 (5) https://bugs.python.org/issue13802 (6) https://bugs.python.org/issue31860 (7) https://bugs.python.org/issue33642 (8) https://bugs.python.org/issue33768 (9) https://bugs.python.org/issue33679 (10) https://bugs.python.org/issue33656 (11) https://bugs.python.org/issue1529353  File: python.info, Node: importlib<3>, Next: inspect<2>, Prev: idlelib and IDLE<2>, Up: Improved Modules<3> 1.3.5.20 importlib .................. Import now raises the new exception *note ModuleNotFoundError: 39a. (subclass of *note ImportError: 334.) when it cannot find a module. Code that current checks for ‘ImportError’ (in try-except) will still work. (Contributed by Eric Snow in bpo-15767(1).) *note importlib.util.LazyLoader: 553. now calls *note create_module(): 554. on the wrapped loader, removing the restriction that *note importlib.machinery.BuiltinImporter: 555. and *note importlib.machinery.ExtensionFileLoader: 556. couldn’t be used with *note importlib.util.LazyLoader: 553. *note importlib.util.cache_from_source(): 557, *note importlib.util.source_from_cache(): 558, and *note importlib.util.spec_from_file_location(): 559. now accept a *note path-like object: 36a. ---------- Footnotes ---------- (1) https://bugs.python.org/issue15767  File: python.info, Node: inspect<2>, Next: json, Prev: importlib<3>, Up: Improved Modules<3> 1.3.5.21 inspect ................ The *note inspect.signature(): 55b. function now reports the implicit ‘.0’ parameters generated by the compiler for comprehension and generator expression scopes as if they were positional-only parameters called ‘implicit0’. (Contributed by Jelle Zijlstra in bpo-19611(1).) To reduce code churn when upgrading from Python 2.7 and the legacy *note inspect.getargspec(): 55c. API, the previously documented deprecation of *note inspect.getfullargspec(): 55d. has been reversed. While this function is convenient for single/source Python 2/3 code bases, the richer *note inspect.signature(): 55b. interface remains the recommended approach for new code. (Contributed by Nick Coghlan in bpo-27172(2)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19611 (2) https://bugs.python.org/issue27172  File: python.info, Node: json, Next: logging<3>, Prev: inspect<2>, Up: Improved Modules<3> 1.3.5.22 json ............. *note json.load(): 55f. and *note json.loads(): 560. now support binary input. Encoded JSON should be represented using either UTF-8, UTF-16, or UTF-32. (Contributed by Serhiy Storchaka in bpo-17909(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17909  File: python.info, Node: logging<3>, Next: math<3>, Prev: json, Up: Improved Modules<3> 1.3.5.23 logging ................ The new *note WatchedFileHandler.reopenIfNeeded(): 562. method has been added to add the ability to check if the log file needs to be reopened. (Contributed by Marian Horban in bpo-24884(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24884  File: python.info, Node: math<3>, Next: multiprocessing<3>, Prev: logging<3>, Up: Improved Modules<3> 1.3.5.24 math ............. The tau (`τ') constant has been added to the *note math: b1. and *note cmath: 19. modules. (Contributed by Lisa Roach in bpo-12345(1), see PEP 628(2) for details.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12345 (2) https://www.python.org/dev/peps/pep-0628  File: python.info, Node: multiprocessing<3>, Next: os<3>, Prev: math<3>, Up: Improved Modules<3> 1.3.5.25 multiprocessing ........................ *note Proxy Objects: 565. returned by ‘multiprocessing.Manager()’ can now be nested. (Contributed by Davin Potts in bpo-6766(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6766  File: python.info, Node: os<3>, Next: pathlib<3>, Prev: multiprocessing<3>, Up: Improved Modules<3> 1.3.5.26 os ........... See the summary of *note PEP 519: 4cd. for details on how the *note os: c4. and *note os.path: c5. modules now support *note path-like objects: 36a. *note scandir(): 25f. now supports *note bytes: 331. paths on Windows. A new *note close(): 567. method allows explicitly closing a *note scandir(): 25f. iterator. The *note scandir(): 25f. iterator now supports the *note context manager: 568. protocol. If a ‘scandir()’ iterator is neither exhausted nor explicitly closed a *note ResourceWarning: 4d0. will be emitted in its destructor. (Contributed by Serhiy Storchaka in bpo-25994(1).) On Linux, *note os.urandom(): 4d1. now blocks until the system urandom entropy pool is initialized to increase the security. See the PEP 524(2) for the rationale. The Linux ‘getrandom()’ syscall (get random bytes) is now exposed as the new *note os.getrandom(): 569. function. (Contributed by Victor Stinner, part of the PEP 524(3)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25994 (2) https://www.python.org/dev/peps/pep-0524 (3) https://www.python.org/dev/peps/pep-0524  File: python.info, Node: pathlib<3>, Next: pdb<2>, Prev: os<3>, Up: Improved Modules<3> 1.3.5.27 pathlib ................ *note pathlib: c8. now supports *note path-like objects: 36a. (Contributed by Brett Cannon in bpo-27186(1).) See the summary of *note PEP 519: 4cd. for details. ---------- Footnotes ---------- (1) https://bugs.python.org/issue27186  File: python.info, Node: pdb<2>, Next: pickle<2>, Prev: pathlib<3>, Up: Improved Modules<3> 1.3.5.28 pdb ............ The *note Pdb: 56c. class constructor has a new optional `readrc' argument to control whether ‘.pdbrc’ files should be read.  File: python.info, Node: pickle<2>, Next: pickletools, Prev: pdb<2>, Up: Improved Modules<3> 1.3.5.29 pickle ............... Objects that need ‘__new__’ called with keyword arguments can now be pickled using *note pickle protocols: 56e. older than protocol version 4. Protocol version 4 already supports this case. (Contributed by Serhiy Storchaka in bpo-24164(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24164  File: python.info, Node: pickletools, Next: pydoc<2>, Prev: pickle<2>, Up: Improved Modules<3> 1.3.5.30 pickletools .................... *note pickletools.dis(): 570. now outputs the implicit memo index for the ‘MEMOIZE’ opcode. (Contributed by Serhiy Storchaka in bpo-25382(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25382  File: python.info, Node: pydoc<2>, Next: random, Prev: pickletools, Up: Improved Modules<3> 1.3.5.31 pydoc .............. The *note pydoc: d9. module has learned to respect the ‘MANPAGER’ environment variable. (Contributed by Matthias Klose in bpo-8637(1).) *note help(): 572. and *note pydoc: d9. can now list named tuple fields in the order they were defined rather than alphabetically. (Contributed by Raymond Hettinger in bpo-24879(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8637 (2) https://bugs.python.org/issue24879  File: python.info, Node: random, Next: re<2>, Prev: pydoc<2>, Up: Improved Modules<3> 1.3.5.32 random ............... The new *note choices(): 574. function returns a list of elements of specified size from the given population with optional weights. (Contributed by Raymond Hettinger in bpo-18844(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18844  File: python.info, Node: re<2>, Next: readline, Prev: random, Up: Improved Modules<3> 1.3.5.33 re ........... Added support of modifier spans in regular expressions. Examples: ‘'(?i:p)ython'’ matches ‘'python'’ and ‘'Python'’, but not ‘'PYTHON'’; ‘'(?i)g(?-i:v)r'’ matches ‘'GvR'’ and ‘'gvr'’, but not ‘'GVR'’. (Contributed by Serhiy Storchaka in bpo-433028(1).) Match object groups can be accessed by ‘__getitem__’, which is equivalent to ‘group()’. So ‘mo['name']’ is now equivalent to ‘mo.group('name')’. (Contributed by Eric Smith in bpo-24454(2).) ‘Match’ objects now support *note index-like objects: 18a. as group indices. (Contributed by Jeroen Demeyer and Xiang Zhang in bpo-27177(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue433028 (2) https://bugs.python.org/issue24454 (3) https://bugs.python.org/issue27177  File: python.info, Node: readline, Next: rlcompleter, Prev: re<2>, Up: Improved Modules<3> 1.3.5.34 readline ................. Added *note set_auto_history(): 577. to enable or disable automatic addition of input to the history list. (Contributed by Tyler Crompton in bpo-26870(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26870  File: python.info, Node: rlcompleter, Next: shlex<2>, Prev: readline, Up: Improved Modules<3> 1.3.5.35 rlcompleter .................... Private and special attribute names now are omitted unless the prefix starts with underscores. A space or a colon is added after some completed keywords. (Contributed by Serhiy Storchaka in bpo-25011(1) and bpo-25209(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25011 (2) https://bugs.python.org/issue25209  File: python.info, Node: shlex<2>, Next: site, Prev: rlcompleter, Up: Improved Modules<3> 1.3.5.36 shlex .............. The *note shlex: 57a. has much *note improved shell compatibility: 57b. through the new `punctuation_chars' argument to control which characters are treated as punctuation. (Contributed by Vinay Sajip in bpo-1521950(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1521950  File: python.info, Node: site, Next: sqlite3<2>, Prev: shlex<2>, Up: Improved Modules<3> 1.3.5.37 site ............. When specifying paths to add to *note sys.path: 488. in a ‘.pth’ file, you may now specify file paths on top of directories (e.g. zip files). (Contributed by Wolfgang Langner in bpo-26587(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue26587  File: python.info, Node: sqlite3<2>, Next: socket<4>, Prev: site, Up: Improved Modules<3> 1.3.5.38 sqlite3 ................ *note sqlite3.Cursor.lastrowid: 57e. now supports the ‘REPLACE’ statement. (Contributed by Alex LordThorsen in bpo-16864(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16864  File: python.info, Node: socket<4>, Next: socketserver<2>, Prev: sqlite3<2>, Up: Improved Modules<3> 1.3.5.39 socket ............... The *note ioctl(): 580. function now supports the *note SIO_LOOPBACK_FAST_PATH: 581. control code. (Contributed by Daniel Stokes in bpo-26536(1).) The *note getsockopt(): 582. constants ‘SO_DOMAIN’, ‘SO_PROTOCOL’, ‘SO_PEERSEC’, and ‘SO_PASSSEC’ are now supported. (Contributed by Christian Heimes in bpo-26907(2).) The *note setsockopt(): 583. now supports the ‘setsockopt(level, optname, None, optlen: int)’ form. (Contributed by Christian Heimes in bpo-27744(3).) The socket module now supports the address family *note AF_ALG: 584. to interface with Linux Kernel crypto API. ‘ALG_*’, ‘SOL_ALG’ and *note sendmsg_afalg(): 585. were added. (Contributed by Christian Heimes in bpo-27744(4) with support from Victor Stinner.) New Linux constants ‘TCP_USER_TIMEOUT’ and ‘TCP_CONGESTION’ were added. (Contributed by Omar Sandoval, issue:‘26273’). ---------- Footnotes ---------- (1) https://bugs.python.org/issue26536 (2) https://bugs.python.org/issue26907 (3) https://bugs.python.org/issue27744 (4) https://bugs.python.org/issue27744  File: python.info, Node: socketserver<2>, Next: ssl<4>, Prev: socket<4>, Up: Improved Modules<3> 1.3.5.40 socketserver ..................... Servers based on the *note socketserver: f0. module, including those defined in *note http.server: 97, *note xmlrpc.server: 140. and *note wsgiref.simple_server: 12f, now support the *note context manager: 568. protocol. (Contributed by Aviv Palivoda in bpo-26404(1).) The ‘wfile’ attribute of *note StreamRequestHandler: 587. classes now implements the *note io.BufferedIOBase: 588. writable interface. In particular, calling *note write(): 589. is now guaranteed to send the data in full. (Contributed by Martin Panter in bpo-26721(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26404 (2) https://bugs.python.org/issue26721  File: python.info, Node: ssl<4>, Next: statistics<2>, Prev: socketserver<2>, Up: Improved Modules<3> 1.3.5.41 ssl ............ *note ssl: f3. supports OpenSSL 1.1.0. The minimum recommend version is 1.0.2. (Contributed by Christian Heimes in bpo-26470(1).) 3DES has been removed from the default cipher suites and ChaCha20 Poly1305 cipher suites have been added. (Contributed by Christian Heimes in bpo-27850(2) and bpo-27766(3).) *note SSLContext: 3e4. has better default configuration for options and ciphers. (Contributed by Christian Heimes in bpo-28043(4).) SSL session can be copied from one client-side connection to another with the new *note SSLSession: 58b. class. TLS session resumption can speed up the initial handshake, reduce latency and improve performance (Contributed by Christian Heimes in bpo-19500(5) based on a draft by Alex Warhawk.) The new *note get_ciphers(): 58c. method can be used to get a list of enabled ciphers in order of cipher priority. All constants and flags have been converted to *note IntEnum: 58d. and ‘IntFlags’. (Contributed by Christian Heimes in bpo-28025(6).) Server and client-side specific TLS protocols for *note SSLContext: 3e4. were added. (Contributed by Christian Heimes in bpo-28085(7).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26470 (2) https://bugs.python.org/issue27850 (3) https://bugs.python.org/issue27766 (4) https://bugs.python.org/issue28043 (5) https://bugs.python.org/issue19500 (6) https://bugs.python.org/issue28025 (7) https://bugs.python.org/issue28085  File: python.info, Node: statistics<2>, Next: struct, Prev: ssl<4>, Up: Improved Modules<3> 1.3.5.42 statistics ................... A new *note harmonic_mean(): 58f. function has been added. (Contributed by Steven D’Aprano in bpo-27181(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27181  File: python.info, Node: struct, Next: subprocess<2>, Prev: statistics<2>, Up: Improved Modules<3> 1.3.5.43 struct ............... *note struct: f8. now supports IEEE 754 half-precision floats via the ‘'e'’ format specifier. (Contributed by Eli Stevens, Mark Dickinson in bpo-11734(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11734  File: python.info, Node: subprocess<2>, Next: sys<4>, Prev: struct, Up: Improved Modules<3> 1.3.5.44 subprocess ................... *note subprocess.Popen: 2b9. destructor now emits a *note ResourceWarning: 4d0. warning if the child process is still running. Use the context manager protocol (‘with proc: ...’) or explicitly call the *note wait(): 592. method to read the exit status of the child process. (Contributed by Victor Stinner in bpo-26741(1).) The *note subprocess.Popen: 2b9. constructor and all functions that pass arguments through to it now accept `encoding' and `errors' arguments. Specifying either of these will enable text mode for the `stdin', `stdout' and `stderr' streams. (Contributed by Steve Dower in bpo-6135(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26741 (2) https://bugs.python.org/issue6135  File: python.info, Node: sys<4>, Next: telnetlib, Prev: subprocess<2>, Up: Improved Modules<3> 1.3.5.45 sys ............ The new *note getfilesystemencodeerrors(): 594. function returns the name of the error mode used to convert between Unicode filenames and bytes filenames. (Contributed by Steve Dower in bpo-27781(1).) On Windows the return value of the *note getwindowsversion(): 595. function now includes the `platform_version' field which contains the accurate major version, minor version and build number of the current operating system, rather than the version that is being emulated for the process (Contributed by Steve Dower in bpo-27932(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27781 (2) https://bugs.python.org/issue27932  File: python.info, Node: telnetlib, Next: time<3>, Prev: sys<4>, Up: Improved Modules<3> 1.3.5.46 telnetlib .................. *note Telnet: 597. is now a context manager (contributed by Stéphane Wirtel in bpo-25485(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue25485  File: python.info, Node: time<3>, Next: timeit, Prev: telnetlib, Up: Improved Modules<3> 1.3.5.47 time ............. The *note struct_time: 599. attributes ‘tm_gmtoff’ and ‘tm_zone’ are now available on all platforms.  File: python.info, Node: timeit, Next: tkinter<3>, Prev: time<3>, Up: Improved Modules<3> 1.3.5.48 timeit ............... The new *note Timer.autorange(): 59b. convenience method has been added to call *note Timer.timeit(): 59c. repeatedly so that the total run time is greater or equal to 200 milliseconds. (Contributed by Steven D’Aprano in bpo-6422(1).) *note timeit: 10b. now warns when there is substantial (4x) variance between best and worst times. (Contributed by Serhiy Storchaka in bpo-23552(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6422 (2) https://bugs.python.org/issue23552  File: python.info, Node: tkinter<3>, Next: traceback, Prev: timeit, Up: Improved Modules<3> 1.3.5.49 tkinter ................ Added methods ‘trace_add()’, ‘trace_remove()’ and ‘trace_info()’ in the ‘tkinter.Variable’ class. They replace old methods ‘trace_variable()’, ‘trace()’, ‘trace_vdelete()’ and ‘trace_vinfo()’ that use obsolete Tcl commands and might not work in future versions of Tcl. (Contributed by Serhiy Storchaka in bpo-22115(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue22115  File: python.info, Node: traceback, Next: tracemalloc<2>, Prev: tkinter<3>, Up: Improved Modules<3> 1.3.5.50 traceback .................. Both the traceback module and the interpreter’s builtin exception display now abbreviate long sequences of repeated lines in tracebacks as shown in the following example: >>> def f(): f() ... >>> f() Traceback (most recent call last): File "", line 1, in File "", line 1, in f File "", line 1, in f File "", line 1, in f [Previous line repeated 995 more times] RecursionError: maximum recursion depth exceeded (Contributed by Emanuel Barry in bpo-26823(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26823  File: python.info, Node: tracemalloc<2>, Next: typing<2>, Prev: traceback, Up: Improved Modules<3> 1.3.5.51 tracemalloc .................... The *note tracemalloc: 114. module now supports tracing memory allocations in multiple different address spaces. The new *note DomainFilter: 5a0. filter class has been added to filter block traces by their address space (domain). (Contributed by Victor Stinner in bpo-26588(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26588  File: python.info, Node: typing<2>, Next: unicodedata<3>, Prev: tracemalloc<2>, Up: Improved Modules<3> 1.3.5.52 typing ............... Since the *note typing: 119. module is *note provisional: 348, all changes introduced in Python 3.6 have also been backported to Python 3.5.x. The *note typing: 119. module has a much improved support for generic type aliases. For example ‘Dict[str, Tuple[S, T]]’ is now a valid type annotation. (Contributed by Guido van Rossum in Github #195(1).) The *note typing.ContextManager: 535. class has been added for representing *note contextlib.AbstractContextManager: 534. (Contributed by Brett Cannon in bpo-25609(2).) The *note typing.Collection: 5a2. class has been added for representing *note collections.abc.Collection: 52d. (Contributed by Ivan Levkivskyi in bpo-27598(3).) The *note typing.ClassVar: 5a3. type construct has been added to mark class variables. As introduced in PEP 526(4), a variable annotation wrapped in ClassVar indicates that a given attribute is intended to be used as a class variable and should not be set on instances of that class. (Contributed by Ivan Levkivskyi in Github #280(5).) A new *note TYPE_CHECKING: 5a4. constant that is assumed to be ‘True’ by the static type checkers, but is ‘False’ at runtime. (Contributed by Guido van Rossum in Github #230(6).) A new *note NewType(): 5a5. helper function has been added to create lightweight distinct types for annotations: from typing import NewType UserId = NewType('UserId', int) some_id = UserId(524313) The static type checker will treat the new type as if it were a subclass of the original type. (Contributed by Ivan Levkivskyi in Github #189(7).) ---------- Footnotes ---------- (1) https://github.com/python/typing/pull/195 (2) https://bugs.python.org/issue25609 (3) https://bugs.python.org/issue27598 (4) https://www.python.org/dev/peps/pep-0526 (5) https://github.com/python/typing/pull/280 (6) https://github.com/python/typing/issues/230 (7) https://github.com/python/typing/issues/189  File: python.info, Node: unicodedata<3>, Next: unittest mock<2>, Prev: typing<2>, Up: Improved Modules<3> 1.3.5.53 unicodedata .................... The *note unicodedata: 11a. module now uses data from Unicode 9.0.0(1). (Contributed by Benjamin Peterson.) ---------- Footnotes ---------- (1) http://unicode.org/versions/Unicode9.0.0/  File: python.info, Node: unittest mock<2>, Next: urllib request, Prev: unicodedata<3>, Up: Improved Modules<3> 1.3.5.54 unittest.mock ...................... The *note Mock: 249. class has the following improvements: * Two new methods, *note Mock.assert_called(): 5a8. and *note Mock.assert_called_once(): 5a9. to check if the mock object was called. (Contributed by Amit Saha in bpo-26323(1).) * The *note Mock.reset_mock(): 5aa. method now has two optional keyword only arguments: `return_value' and `side_effect'. (Contributed by Kushal Das in bpo-21271(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26323 (2) https://bugs.python.org/issue21271  File: python.info, Node: urllib request, Next: urllib robotparser, Prev: unittest mock<2>, Up: Improved Modules<3> 1.3.5.55 urllib.request ....................... If a HTTP request has a file or iterable body (other than a bytes object) but no ‘Content-Length’ header, rather than throwing an error, ‘AbstractHTTPHandler’ now falls back to use chunked transfer encoding. (Contributed by Demian Brecht and Rolf Krahl in bpo-12319(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12319  File: python.info, Node: urllib robotparser, Next: venv<2>, Prev: urllib request, Up: Improved Modules<3> 1.3.5.56 urllib.robotparser ........................... *note RobotFileParser: 5ad. now supports the ‘Crawl-delay’ and ‘Request-rate’ extensions. (Contributed by Nikolay Bogoychev in bpo-16099(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16099  File: python.info, Node: venv<2>, Next: warnings<2>, Prev: urllib robotparser, Up: Improved Modules<3> 1.3.5.57 venv ............. *note venv: 125. accepts a new parameter ‘--prompt’. This parameter provides an alternative prefix for the virtual environment. (Proposed by Łukasz Balcerzak and ported to 3.6 by Stéphane Wirtel in bpo-22829(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22829  File: python.info, Node: warnings<2>, Next: winreg, Prev: venv<2>, Up: Improved Modules<3> 1.3.5.58 warnings ................. A new optional `source' parameter has been added to the *note warnings.warn_explicit(): 5b0. function: the destroyed object which emitted a *note ResourceWarning: 4d0. A `source' attribute has also been added to ‘warnings.WarningMessage’ (contributed by Victor Stinner in bpo-26568(1) and bpo-26567(2)). When a *note ResourceWarning: 4d0. warning is logged, the *note tracemalloc: 114. module is now used to try to retrieve the traceback where the destroyed object was allocated. Example with the script ‘example.py’: import warnings def func(): return open(__file__) f = func() f = None Output of the command ‘python3.6 -Wd -X tracemalloc=5 example.py’: example.py:7: ResourceWarning: unclosed file <_io.TextIOWrapper name='example.py' mode='r' encoding='UTF-8'> f = None Object allocated at (most recent call first): File "example.py", lineno 4 return open(__file__) File "example.py", lineno 6 f = func() The “Object allocated at” traceback is new and is only displayed if *note tracemalloc: 114. is tracing Python memory allocations and if the *note warnings: 126. module was already imported. ---------- Footnotes ---------- (1) https://bugs.python.org/issue26568 (2) https://bugs.python.org/issue26567  File: python.info, Node: winreg, Next: winsound, Prev: warnings<2>, Up: Improved Modules<3> 1.3.5.59 winreg ............... Added the 64-bit integer type *note REG_QWORD: 5b2. (Contributed by Clement Rouault in bpo-23026(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23026  File: python.info, Node: winsound, Next: xmlrpc client, Prev: winreg, Up: Improved Modules<3> 1.3.5.60 winsound ................. Allowed keyword arguments to be passed to *note Beep: 5b4, *note MessageBeep: 5b5, and *note PlaySound: 5b6. (bpo-27982(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue27982  File: python.info, Node: xmlrpc client, Next: zipfile<2>, Prev: winsound, Up: Improved Modules<3> 1.3.5.61 xmlrpc.client ...................... The *note xmlrpc.client: 13f. module now supports unmarshalling additional data types used by the Apache XML-RPC implementation for numerics and ‘None’. (Contributed by Serhiy Storchaka in bpo-26885(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26885  File: python.info, Node: zipfile<2>, Next: zlib, Prev: xmlrpc client, Up: Improved Modules<3> 1.3.5.62 zipfile ................ A new *note ZipInfo.from_file(): 5b9. class method allows making a *note ZipInfo: 5ba. instance from a filesystem file. A new *note ZipInfo.is_dir(): 5bb. method can be used to check if the *note ZipInfo: 5ba. instance represents a directory. (Contributed by Thomas Kluyver in bpo-26039(1).) The *note ZipFile.open(): 5bc. method can now be used to write data into a ZIP file, as well as for extracting data. (Contributed by Thomas Kluyver in bpo-26039(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26039 (2) https://bugs.python.org/issue26039  File: python.info, Node: zlib, Prev: zipfile<2>, Up: Improved Modules<3> 1.3.5.63 zlib ............. The *note compress(): 5be. and *note decompress(): 5bf. functions now accept keyword arguments. (Contributed by Aviv Palivoda in bpo-26243(1) and Xiang Zhang in bpo-16764(2) respectively.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26243 (2) https://bugs.python.org/issue16764  File: python.info, Node: Optimizations<3>, Next: Build and C API Changes<2>, Prev: Improved Modules<3>, Up: What’s New In Python 3 6 1.3.6 Optimizations ------------------- * The Python interpreter now uses a 16-bit wordcode instead of bytecode which made a number of opcode optimizations possible. (Contributed by Demur Rumed with input and reviews from Serhiy Storchaka and Victor Stinner in bpo-26647(1) and bpo-28050(2).) * The *note asyncio.Future: 443. class now has an optimized C implementation. (Contributed by Yury Selivanov and INADA Naoki in bpo-26081(3).) * The *note asyncio.Task: 1ad. class now has an optimized C implementation. (Contributed by Yury Selivanov in bpo-28544(4).) * Various implementation improvements in the *note typing: 119. module (such as caching of generic types) allow up to 30 times performance improvements and reduced memory footprint. * The ASCII decoder is now up to 60 times as fast for error handlers ‘surrogateescape’, ‘ignore’ and ‘replace’ (Contributed by Victor Stinner in bpo-24870(5)). * The ASCII and the Latin1 encoders are now up to 3 times as fast for the error handler ‘surrogateescape’ (Contributed by Victor Stinner in bpo-25227(6)). * The UTF-8 encoder is now up to 75 times as fast for error handlers ‘ignore’, ‘replace’, ‘surrogateescape’, ‘surrogatepass’ (Contributed by Victor Stinner in bpo-25267(7)). * The UTF-8 decoder is now up to 15 times as fast for error handlers ‘ignore’, ‘replace’ and ‘surrogateescape’ (Contributed by Victor Stinner in bpo-25301(8)). * ‘bytes % args’ is now up to 2 times faster. (Contributed by Victor Stinner in bpo-25349(9)). * ‘bytearray % args’ is now between 2.5 and 5 times faster. (Contributed by Victor Stinner in bpo-25399(10)). * Optimize *note bytes.fromhex(): 32e. and *note bytearray.fromhex(): 32f.: they are now between 2x and 3.5x faster. (Contributed by Victor Stinner in bpo-25401(11)). * Optimize ‘bytes.replace(b'', b'.')’ and ‘bytearray.replace(b'', b'.')’: up to 80% faster. (Contributed by Josh Snider in bpo-26574(12)). * Allocator functions of the *note PyMem_Malloc(): 505. domain (*note PYMEM_DOMAIN_MEM: 509.) now use the *note pymalloc memory allocator: 5c1. instead of ‘malloc()’ function of the C library. The pymalloc allocator is optimized for objects smaller or equal to 512 bytes with a short lifetime, and use ‘malloc()’ for larger memory blocks. (Contributed by Victor Stinner in bpo-26249(13)). * *note pickle.load(): 5c2. and *note pickle.loads(): 5c3. are now up to 10% faster when deserializing many small objects (Contributed by Victor Stinner in bpo-27056(14)). * Passing *note keyword arguments: 5c4. to a function has an overhead in comparison with passing *note positional arguments: 5c5. Now in extension functions implemented with using Argument Clinic this overhead is significantly decreased. (Contributed by Serhiy Storchaka in bpo-27574(15)). * Optimized *note glob(): 5c6. and *note iglob(): 5c7. functions in the *note glob: 8a. module; they are now about 3–6 times faster. (Contributed by Serhiy Storchaka in bpo-25596(16)). * Optimized globbing in *note pathlib: c8. by using *note os.scandir(): 25f.; it is now about 1.5–4 times faster. (Contributed by Serhiy Storchaka in bpo-26032(17)). * *note xml.etree.ElementTree: 137. parsing, iteration and deepcopy performance has been significantly improved. (Contributed by Serhiy Storchaka in bpo-25638(18), bpo-25873(19), and bpo-25869(20).) * Creation of *note fractions.Fraction: 185. instances from floats and decimals is now 2 to 3 times faster. (Contributed by Serhiy Storchaka in bpo-25971(21).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26647 (2) https://bugs.python.org/issue28050 (3) https://bugs.python.org/issue26081 (4) https://bugs.python.org/issue28544 (5) https://bugs.python.org/issue24870 (6) https://bugs.python.org/issue25227 (7) https://bugs.python.org/issue25267 (8) https://bugs.python.org/issue25301 (9) https://bugs.python.org/issue25349 (10) https://bugs.python.org/issue25399 (11) https://bugs.python.org/issue25401 (12) https://bugs.python.org/issue26574 (13) https://bugs.python.org/issue26249 (14) https://bugs.python.org/issue27056 (15) https://bugs.python.org/issue27574 (16) https://bugs.python.org/issue25596 (17) https://bugs.python.org/issue26032 (18) https://bugs.python.org/issue25638 (19) https://bugs.python.org/issue25873 (20) https://bugs.python.org/issue25869 (21) https://bugs.python.org/issue25971  File: python.info, Node: Build and C API Changes<2>, Next: Other Improvements, Prev: Optimizations<3>, Up: What’s New In Python 3 6 1.3.7 Build and C API Changes ----------------------------- * Python now requires some C99 support in the toolchain to build. Most notably, Python now uses standard integer types and macros in place of custom macros like ‘PY_LONG_LONG’. For more information, see PEP 7(1) and bpo-17884(2). * Cross-compiling CPython with the Android NDK and the Android API level set to 21 (Android 5.0 Lollipop) or greater runs successfully. While Android is not yet a supported platform, the Python test suite runs on the Android emulator with only about 16 tests failures. See the Android meta-issue bpo-26865(3). * The ‘--enable-optimizations’ configure flag has been added. Turning it on will activate expensive optimizations like PGO. (Original patch by Alecsandru Patrascu of Intel in bpo-26359(4).) * The *note GIL: 506. must now be held when allocator functions of *note PYMEM_DOMAIN_OBJ: 507. (ex: *note PyObject_Malloc(): 508.) and *note PYMEM_DOMAIN_MEM: 509. (ex: *note PyMem_Malloc(): 505.) domains are called. * New *note Py_FinalizeEx(): 5c9. API which indicates if flushing buffered data failed. (Contributed by Martin Panter in bpo-5319(5).) * *note PyArg_ParseTupleAndKeywords(): 5ca. now supports *note positional-only parameters: 2a7. Positional-only parameters are defined by empty names. (Contributed by Serhiy Storchaka in bpo-26282(6)). * ‘PyTraceback_Print’ method now abbreviates long sequences of repeated lines as ‘"[Previous line repeated {count} more times]"’. (Contributed by Emanuel Barry in bpo-26823(7).) * The new *note PyErr_SetImportErrorSubclass(): 5cb. function allows for specifying a subclass of *note ImportError: 334. to raise. (Contributed by Eric Snow in bpo-15767(8).) * The new *note PyErr_ResourceWarning(): 5cc. function can be used to generate a *note ResourceWarning: 4d0. providing the source of the resource allocation. (Contributed by Victor Stinner in bpo-26567(9).) * The new *note PyOS_FSPath(): 5cd. function returns the file system representation of a *note path-like object: 36a. (Contributed by Brett Cannon in bpo-27186(10).) * The *note PyUnicode_FSConverter(): 5ce. and *note PyUnicode_FSDecoder(): 5cf. functions will now accept *note path-like objects: 36a. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0007 (2) https://bugs.python.org/issue17884 (3) https://bugs.python.org/issue26865 (4) https://bugs.python.org/issue26359 (5) https://bugs.python.org/issue5319 (6) https://bugs.python.org/issue26282 (7) https://bugs.python.org/issue26823 (8) https://bugs.python.org/issue15767 (9) https://bugs.python.org/issue26567 (10) https://bugs.python.org/issue27186  File: python.info, Node: Other Improvements, Next: Deprecated<2>, Prev: Build and C API Changes<2>, Up: What’s New In Python 3 6 1.3.8 Other Improvements ------------------------ * When *note –version: 5d1. (short form: *note -V: 5d2.) is supplied twice, Python prints *note sys.version: 5d3. for detailed information. $ ./python -VV Python 3.6.0b4+ (3.6:223967b49e49+, Nov 21 2016, 20:55:04) [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)]  File: python.info, Node: Deprecated<2>, Next: Removed, Prev: Other Improvements, Up: What’s New In Python 3 6 1.3.9 Deprecated ---------------- * Menu: * New Keywords:: * Deprecated Python behavior:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<2>. * Deprecated functions and types of the C API: Deprecated functions and types of the C API<2>. * Deprecated Build Options::  File: python.info, Node: New Keywords, Next: Deprecated Python behavior, Up: Deprecated<2> 1.3.9.1 New Keywords .................... ‘async’ and ‘await’ are not recommended to be used as variable, class, function or module names. Introduced by PEP 492(1) in Python 3.5, they will become proper keywords in Python 3.7. Starting in Python 3.6, the use of ‘async’ or ‘await’ as names will generate a *note DeprecationWarning: 278. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0492  File: python.info, Node: Deprecated Python behavior, Next: Deprecated Python modules functions and methods<2>, Prev: New Keywords, Up: Deprecated<2> 1.3.9.2 Deprecated Python behavior .................................. Raising the *note StopIteration: 486. exception inside a generator will now generate a *note DeprecationWarning: 278, and will trigger a *note RuntimeError: 2ba. in Python 3.7. See *note PEP 479; Change StopIteration handling inside generators: 5d7. for details. The *note __aiter__(): 487. method is now expected to return an asynchronous iterator directly instead of returning an awaitable as previously. Doing the former will trigger a *note DeprecationWarning: 278. Backward compatibility will be removed in Python 3.7. (Contributed by Yury Selivanov in bpo-27243(1).) A backslash-character pair that is not a valid escape sequence now generates a *note DeprecationWarning: 278. Although this will eventually become a *note SyntaxError: 458, that will not be for several Python releases. (Contributed by Emanuel Barry in bpo-27364(2).) When performing a relative import, falling back on ‘__name__’ and ‘__path__’ from the calling module when ‘__spec__’ or ‘__package__’ are not defined now raises an *note ImportWarning: 5d8. (Contributed by Rose Ames in bpo-25791(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue27243 (2) https://bugs.python.org/issue27364 (3) https://bugs.python.org/issue25791  File: python.info, Node: Deprecated Python modules functions and methods<2>, Next: Deprecated functions and types of the C API<2>, Prev: Deprecated Python behavior, Up: Deprecated<2> 1.3.9.3 Deprecated Python modules, functions and methods ........................................................ * Menu: * asynchat:: * asyncore:: * dbm: dbm<3>. * distutils: distutils<3>. * grp:: * importlib: importlib<4>. * os: os<4>. * re: re<3>. * ssl: ssl<5>. * tkinter: tkinter<4>. * venv: venv<3>.  File: python.info, Node: asynchat, Next: asyncore, Up: Deprecated Python modules functions and methods<2> 1.3.9.4 asynchat ................ The *note asynchat: 9. has been deprecated in favor of *note asyncio: a. (Contributed by Mariatta in bpo-25002(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25002  File: python.info, Node: asyncore, Next: dbm<3>, Prev: asynchat, Up: Deprecated Python modules functions and methods<2> 1.3.9.5 asyncore ................ The *note asyncore: b. has been deprecated in favor of *note asyncio: a. (Contributed by Mariatta in bpo-25002(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25002  File: python.info, Node: dbm<3>, Next: distutils<3>, Prev: asyncore, Up: Deprecated Python modules functions and methods<2> 1.3.9.6 dbm ........... Unlike other *note dbm: 32. implementations, the *note dbm.dumb: 33. module creates databases with the ‘'rw'’ mode and allows modifying the database opened with the ‘'r'’ mode. This behavior is now deprecated and will be removed in 3.8. (Contributed by Serhiy Storchaka in bpo-21708(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21708  File: python.info, Node: distutils<3>, Next: grp, Prev: dbm<3>, Up: Deprecated Python modules functions and methods<2> 1.3.9.7 distutils ................. The undocumented ‘extra_path’ argument to the ‘Distribution’ constructor is now considered deprecated and will raise a warning if set. Support for this parameter will be removed in a future Python release. See bpo-27919(1) for details. ---------- Footnotes ---------- (1) https://bugs.python.org/issue27919  File: python.info, Node: grp, Next: importlib<4>, Prev: distutils<3>, Up: Deprecated Python modules functions and methods<2> 1.3.9.8 grp ........... The support of non-integer arguments in *note getgrgid(): 5df. has been deprecated. (Contributed by Serhiy Storchaka in bpo-26129(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26129  File: python.info, Node: importlib<4>, Next: os<4>, Prev: grp, Up: Deprecated Python modules functions and methods<2> 1.3.9.9 importlib ................. The *note importlib.machinery.SourceFileLoader.load_module(): 5e1. and *note importlib.machinery.SourcelessFileLoader.load_module(): 5e2. methods are now deprecated. They were the only remaining implementations of *note importlib.abc.Loader.load_module(): 5e3. in *note importlib: 9b. that had not been deprecated in previous versions of Python in favour of *note importlib.abc.Loader.exec_module(): 5e4. The *note importlib.machinery.WindowsRegistryFinder: 5e5. class is now deprecated. As of 3.6.0, it is still added to *note sys.meta_path: 5e6. by default (on Windows), but this may change in future releases.  File: python.info, Node: os<4>, Next: re<3>, Prev: importlib<4>, Up: Deprecated Python modules functions and methods<2> 1.3.9.10 os ........... Undocumented support of general *note bytes-like objects: 5e8. as paths in *note os: c4. functions, *note compile(): 1b4. and similar functions is now deprecated. (Contributed by Serhiy Storchaka in bpo-25791(1) and bpo-26754(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25791 (2) https://bugs.python.org/issue26754  File: python.info, Node: re<3>, Next: ssl<5>, Prev: os<4>, Up: Deprecated Python modules functions and methods<2> 1.3.9.11 re ........... Support for inline flags ‘(?letters)’ in the middle of the regular expression has been deprecated and will be removed in a future Python version. Flags at the start of a regular expression are still allowed. (Contributed by Serhiy Storchaka in bpo-22493(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22493  File: python.info, Node: ssl<5>, Next: tkinter<4>, Prev: re<3>, Up: Deprecated Python modules functions and methods<2> 1.3.9.12 ssl ............ OpenSSL 0.9.8, 1.0.0 and 1.0.1 are deprecated and no longer supported. In the future the *note ssl: f3. module will require at least OpenSSL 1.0.2 or 1.1.0. SSL-related arguments like ‘certfile’, ‘keyfile’ and ‘check_hostname’ in *note ftplib: 84, *note http.client: 94, *note imaplib: 98, *note poplib: d0, and *note smtplib: ed. have been deprecated in favor of ‘context’. (Contributed by Christian Heimes in bpo-28022(1).) A couple of protocols and functions of the *note ssl: f3. module are now deprecated. Some features will no longer be available in future versions of OpenSSL. Other features are deprecated in favor of a different API. (Contributed by Christian Heimes in bpo-28022(2) and bpo-26470(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue28022 (2) https://bugs.python.org/issue28022 (3) https://bugs.python.org/issue26470  File: python.info, Node: tkinter<4>, Next: venv<3>, Prev: ssl<5>, Up: Deprecated Python modules functions and methods<2> 1.3.9.13 tkinter ................ The *note tkinter.tix: 10e. module is now deprecated. *note tkinter: 10c. users should use *note tkinter.ttk: 10f. instead.  File: python.info, Node: venv<3>, Prev: tkinter<4>, Up: Deprecated Python modules functions and methods<2> 1.3.9.14 venv ............. The ‘pyvenv’ script has been deprecated in favour of ‘python3 -m venv’. This prevents confusion as to what Python interpreter ‘pyvenv’ is connected to and thus what Python interpreter will be used by the virtual environment. (Contributed by Brett Cannon in bpo-25154(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue25154  File: python.info, Node: Deprecated functions and types of the C API<2>, Next: Deprecated Build Options, Prev: Deprecated Python modules functions and methods<2>, Up: Deprecated<2> 1.3.9.15 Deprecated functions and types of the C API .................................................... Undocumented functions ‘PyUnicode_AsEncodedObject()’, ‘PyUnicode_AsDecodedObject()’, ‘PyUnicode_AsEncodedUnicode()’ and ‘PyUnicode_AsDecodedUnicode()’ are deprecated now. Use the *note generic codec based API: 5ee. instead.  File: python.info, Node: Deprecated Build Options, Prev: Deprecated functions and types of the C API<2>, Up: Deprecated<2> 1.3.9.16 Deprecated Build Options ................................. The ‘--with-system-ffi’ configure flag is now on by default on non-macOS UNIX platforms. It may be disabled by using ‘--without-system-ffi’, but using the flag is deprecated and will not be accepted in Python 3.7. macOS is unaffected by this change. Note that many OS distributors already use the ‘--with-system-ffi’ flag when building their system Python.  File: python.info, Node: Removed, Next: Porting to Python 3 6, Prev: Deprecated<2>, Up: What’s New In Python 3 6 1.3.10 Removed -------------- * Menu: * API and Feature Removals: API and Feature Removals<3>.  File: python.info, Node: API and Feature Removals<3>, Up: Removed 1.3.10.1 API and Feature Removals ................................. * Unknown escapes consisting of ‘'\'’ and an ASCII letter in regular expressions will now cause an error. In replacement templates for *note re.sub(): 47b. they are still allowed, but deprecated. The *note re.LOCALE: 3c9. flag can now only be used with binary patterns. * ‘inspect.getmoduleinfo()’ was removed (was deprecated since CPython 3.3). *note inspect.getmodulename(): 5f2. should be used for obtaining the module name for a given path. (Contributed by Yury Selivanov in bpo-13248(1).) * ‘traceback.Ignore’ class and ‘traceback.usage’, ‘traceback.modname’, ‘traceback.fullmodname’, ‘traceback.find_lines_from_code’, ‘traceback.find_lines’, ‘traceback.find_strings’, ‘traceback.find_executable_lines’ methods were removed from the *note traceback: 113. module. They were undocumented methods deprecated since Python 3.2 and equivalent functionality is available from private methods. * The ‘tk_menuBar()’ and ‘tk_bindForTraversal()’ dummy methods in *note tkinter: 10c. widget classes were removed (corresponding Tk commands were obsolete since Tk 4.0). * The *note open(): 5bc. method of the *note zipfile.ZipFile: 41f. class no longer supports the ‘'U'’ mode (was deprecated since Python 3.4). Use *note io.TextIOWrapper: 5f3. for reading compressed text files in *note universal newlines: 5f4. mode. * The undocumented ‘IN’, ‘CDROM’, ‘DLFCN’, ‘TYPES’, ‘CDIO’, and ‘STROPTS’ modules have been removed. They had been available in the platform specific ‘Lib/plat-*/’ directories, but were chronically out of date, inconsistently available across platforms, and unmaintained. The script that created these modules is still available in the source distribution at Tools/scripts/h2py.py(2). * The deprecated ‘asynchat.fifo’ class has been removed. ---------- Footnotes ---------- (1) https://bugs.python.org/issue13248 (2) https://github.com/python/cpython/tree/3.8/Tools/scripts/h2py.py  File: python.info, Node: Porting to Python 3 6, Next: Notable changes in Python 3 6 2, Prev: Removed, Up: What’s New In Python 3 6 1.3.11 Porting to Python 3.6 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Changes in ‘python’ Command Behavior:: * Changes in the Python API: Changes in the Python API<3>. * Changes in the C API: Changes in the C API<3>. * CPython bytecode changes: CPython bytecode changes<3>.  File: python.info, Node: Changes in ‘python’ Command Behavior, Next: Changes in the Python API<3>, Up: Porting to Python 3 6 1.3.11.1 Changes in ‘python’ Command Behavior ............................................. * The output of a special Python build with defined ‘COUNT_ALLOCS’, ‘SHOW_ALLOC_COUNT’ or ‘SHOW_TRACK_COUNT’ macros is now off by default. It can be re-enabled using the ‘-X showalloccount’ option. It now outputs to ‘stderr’ instead of ‘stdout’. (Contributed by Serhiy Storchaka in bpo-23034(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23034  File: python.info, Node: Changes in the Python API<3>, Next: Changes in the C API<3>, Prev: Changes in ‘python’ Command Behavior, Up: Porting to Python 3 6 1.3.11.2 Changes in the Python API .................................. * *note open(): 4f0. will no longer allow combining the ‘'U'’ mode flag with ‘'+'’. (Contributed by Jeff Balogh and John O’Connor in bpo-2091(1).) * *note sqlite3: f2. no longer implicitly commits an open transaction before DDL statements. * On Linux, *note os.urandom(): 4d1. now blocks until the system urandom entropy pool is initialized to increase the security. * When *note importlib.abc.Loader.exec_module(): 5e4. is defined, *note importlib.abc.Loader.create_module(): 554. must also be defined. * *note PyErr_SetImportError(): 5f8. now sets *note TypeError: 192. when its `msg' argument is not set. Previously only ‘NULL’ was returned. * The format of the ‘co_lnotab’ attribute of code objects changed to support a negative line number delta. By default, Python does not emit bytecode with a negative line number delta. Functions using ‘frame.f_lineno’, ‘PyFrame_GetLineNumber()’ or ‘PyCode_Addr2Line()’ are not affected. Functions directly decoding ‘co_lnotab’ should be updated to use a signed 8-bit integer type for the line number delta, but this is only required to support applications using a negative line number delta. See ‘Objects/lnotab_notes.txt’ for the ‘co_lnotab’ format and how to decode it, and see the PEP 511(2) for the rationale. * The functions in the *note compileall: 21. module now return booleans instead of ‘1’ or ‘0’ to represent success or failure, respectively. Thanks to booleans being a subclass of integers, this should only be an issue if you were doing identity checks for ‘1’ or ‘0’. See bpo-25768(3). * Reading the ‘port’ attribute of *note urllib.parse.urlsplit(): 5f9. and *note urlparse(): 5fa. results now raises *note ValueError: 1fb. for out-of-range values, rather than returning *note None: 157. See bpo-20059(4). * The *note imp: 9a. module now raises a *note DeprecationWarning: 278. instead of *note PendingDeprecationWarning: 279. * The following modules have had missing APIs added to their ‘__all__’ attributes to match the documented APIs: *note calendar: 15, *note cgi: 16, *note csv: 2a, *note ElementTree: 137, *note enum: 7b, *note fileinput: 80, *note ftplib: 84, *note logging: aa, *note mailbox: ae, *note mimetypes: b2, *note optparse: c3, *note plistlib: cf, *note smtpd: ec, *note subprocess: f9, *note tarfile: 101, *note threading: 109. and *note wave: 127. This means they will export new symbols when ‘import *’ is used. (Contributed by Joel Taddei and Jacek Kołodziej in bpo-23883(5).) * When performing a relative import, if ‘__package__’ does not compare equal to ‘__spec__.parent’ then *note ImportWarning: 5d8. is raised. (Contributed by Brett Cannon in bpo-25791(6).) * When a relative import is performed and no parent package is known, then *note ImportError: 334. will be raised. Previously, *note SystemError: 5fb. could be raised. (Contributed by Brett Cannon in bpo-18018(7).) * Servers based on the *note socketserver: f0. module, including those defined in *note http.server: 97, *note xmlrpc.server: 140. and *note wsgiref.simple_server: 12f, now only catch exceptions derived from *note Exception: 1a9. Therefore if a request handler raises an exception like *note SystemExit: 5fc. or *note KeyboardInterrupt: 197, *note handle_error(): 5fd. is no longer called, and the exception will stop a single-threaded server. (Contributed by Martin Panter in bpo-23430(8).) * *note spwd.getspnam(): 5fe. now raises a *note PermissionError: 5ff. instead of *note KeyError: 2c7. if the user doesn’t have privileges. * The *note socket.socket.close(): 600. method now raises an exception if an error (e.g. ‘EBADF’) was reported by the underlying system call. (Contributed by Martin Panter in bpo-26685(9).) * The `decode_data' argument for the *note smtpd.SMTPChannel: 601. and *note smtpd.SMTPServer: 602. constructors is now ‘False’ by default. This means that the argument passed to *note process_message(): 603. is now a bytes object by default, and ‘process_message()’ will be passed keyword arguments. Code that has already been updated in accordance with the deprecation warning generated by 3.5 will not be affected. * All optional arguments of the *note dump(): 604, *note dumps(): 605, *note load(): 55f. and *note loads(): 560. functions and *note JSONEncoder: 606. and *note JSONDecoder: 607. class constructors in the *note json: a4. module are now *note keyword-only: 2ac. (Contributed by Serhiy Storchaka in bpo-18726(10).) * Subclasses of *note type: 608. which don’t override ‘type.__new__’ may no longer use the one-argument form to get the type of an object. * As part of PEP 487(11), the handling of keyword arguments passed to *note type: 608. (other than the metaclass hint, ‘metaclass’) is now consistently delegated to *note object.__init_subclass__(): 4e3. This means that ‘type.__new__()’ and ‘type.__init__()’ both now accept arbitrary keyword arguments, but *note object.__init_subclass__(): 4e3. (which is called from ‘type.__new__()’) will reject them by default. Custom metaclasses accepting additional keyword arguments will need to adjust their calls to ‘type.__new__()’ (whether direct or via *note super: 4e2.) accordingly. * In ‘distutils.command.sdist.sdist’, the ‘default_format’ attribute has been removed and is no longer honored. Instead, the gzipped tarfile format is the default on all platforms and no platform-specific selection is made. In environments where distributions are built on Windows and zip distributions are required, configure the project with a ‘setup.cfg’ file containing the following: [sdist] formats=zip This behavior has also been backported to earlier Python versions by Setuptools 26.0.0. * In the *note urllib.request: 120. module and the *note http.client.HTTPConnection.request(): 54f. method, if no Content-Length header field has been specified and the request body is a file object, it is now sent with HTTP 1.1 chunked encoding. If a file object has to be sent to a HTTP 1.0 server, the Content-Length value now has to be specified by the caller. (Contributed by Demian Brecht and Rolf Krahl with tweaks from Martin Panter in bpo-12319(12).) * The *note DictReader: 1bd. now returns rows of type *note OrderedDict: 1b9. (Contributed by Steve Holden in bpo-27842(13).) * The *note crypt.METHOD_CRYPT: 609. will no longer be added to ‘crypt.methods’ if unsupported by the platform. (Contributed by Victor Stinner in bpo-25287(14).) * The `verbose' and `rename' arguments for *note namedtuple(): 1b7. are now keyword-only. (Contributed by Raymond Hettinger in bpo-25628(15).) * On Linux, *note ctypes.util.find_library(): 60a. now looks in ‘LD_LIBRARY_PATH’ for shared libraries. (Contributed by Vinay Sajip in bpo-9998(16).) * The *note imaplib.IMAP4: 60b. class now handles flags containing the ‘']'’ character in messages sent from the server to improve real-world compatibility. (Contributed by Lita Cho in bpo-21815(17).) * The ‘mmap.write()’ function now returns the number of bytes written like other write methods. (Contributed by Jakub Stasiak in bpo-26335(18).) * The *note pkgutil.iter_modules(): 60c. and *note pkgutil.walk_packages(): 48b. functions now return *note ModuleInfo: 60d. named tuples. (Contributed by Ramchandra Apte in bpo-17211(19).) * *note re.sub(): 47b. now raises an error for invalid numerical group references in replacement templates even if the pattern is not found in the string. The error message for invalid group references now includes the group index and the position of the reference. (Contributed by SilentGhost, Serhiy Storchaka in bpo-25953(20).) * *note zipfile.ZipFile: 41f. will now raise *note NotImplementedError: 60e. for unrecognized compression values. Previously a plain *note RuntimeError: 2ba. was raised. Additionally, calling *note ZipFile: 41f. methods on a closed ZipFile or calling the *note write(): 60f. method on a ZipFile created with mode ‘'r'’ will raise a *note ValueError: 1fb. Previously, a *note RuntimeError: 2ba. was raised in those scenarios. * when custom metaclasses are combined with zero-argument *note super(): 4e2. or direct references from methods to the implicit ‘__class__’ closure variable, the implicit ‘__classcell__’ namespace entry must now be passed up to ‘type.__new__’ for initialisation. Failing to do so will result in a *note DeprecationWarning: 278. in Python 3.6 and a *note RuntimeError: 2ba. in Python 3.8. * With the introduction of *note ModuleNotFoundError: 39a, import system consumers may start expecting import system replacements to raise that more specific exception when appropriate, rather than the less-specific *note ImportError: 334. To provide future compatibility with such consumers, implementors of alternative import systems that completely replace *note __import__(): 610. will need to update their implementations to raise the new subclass when a module can’t be found at all. Implementors of compliant plugins to the default import system shouldn’t need to make any changes, as the default import system will raise the new subclass when appropriate. ---------- Footnotes ---------- (1) https://bugs.python.org/issue2091 (2) https://www.python.org/dev/peps/pep-0511 (3) https://bugs.python.org/issue25768 (4) https://bugs.python.org/issue20059 (5) https://bugs.python.org/issue23883 (6) https://bugs.python.org/issue25791 (7) https://bugs.python.org/issue18018 (8) https://bugs.python.org/issue23430 (9) https://bugs.python.org/issue26685 (10) https://bugs.python.org/issue18726 (11) https://www.python.org/dev/peps/pep-0487 (12) https://bugs.python.org/issue12319 (13) https://bugs.python.org/issue27842 (14) https://bugs.python.org/issue25287 (15) https://bugs.python.org/issue25628 (16) https://bugs.python.org/issue9998 (17) https://bugs.python.org/issue21815 (18) https://bugs.python.org/issue26335 (19) https://bugs.python.org/issue17211 (20) https://bugs.python.org/issue25953  File: python.info, Node: Changes in the C API<3>, Next: CPython bytecode changes<3>, Prev: Changes in the Python API<3>, Up: Porting to Python 3 6 1.3.11.3 Changes in the C API ............................. * The *note PyMem_Malloc(): 505. allocator family now uses the *note pymalloc allocator: 5c1. rather than the system ‘malloc()’. Applications calling *note PyMem_Malloc(): 505. without holding the GIL can now crash. Set the *note PYTHONMALLOC: 503. environment variable to ‘debug’ to validate the usage of memory allocators in your application. See bpo-26249(1). * *note Py_Exit(): 612. (and the main interpreter) now override the exit status with 120 if flushing buffered data failed. See bpo-5319(2). ---------- Footnotes ---------- (1) https://bugs.python.org/issue26249 (2) https://bugs.python.org/issue5319  File: python.info, Node: CPython bytecode changes<3>, Prev: Changes in the C API<3>, Up: Porting to Python 3 6 1.3.11.4 CPython bytecode changes ................................. There have been several major changes to the *note bytecode: 614. in Python 3.6. * The Python interpreter now uses a 16-bit wordcode instead of bytecode. (Contributed by Demur Rumed with input and reviews from Serhiy Storchaka and Victor Stinner in bpo-26647(1) and bpo-28050(2).) * The new *note FORMAT_VALUE: 615. and *note BUILD_STRING: 616. opcodes as part of the *note formatted string literal: 4c1. implementation. (Contributed by Eric Smith in bpo-25483(3) and Serhiy Storchaka in bpo-27078(4).) * The new *note BUILD_CONST_KEY_MAP: 617. opcode to optimize the creation of dictionaries with constant keys. (Contributed by Serhiy Storchaka in bpo-27140(5).) * The function call opcodes have been heavily reworked for better performance and simpler implementation. The *note MAKE_FUNCTION: 618, *note CALL_FUNCTION: 619, *note CALL_FUNCTION_KW: 61a. and *note BUILD_MAP_UNPACK_WITH_CALL: 61b. opcodes have been modified, the new *note CALL_FUNCTION_EX: 61c. and *note BUILD_TUPLE_UNPACK_WITH_CALL: 61d. have been added, and ‘CALL_FUNCTION_VAR’, ‘CALL_FUNCTION_VAR_KW’ and ‘MAKE_CLOSURE’ opcodes have been removed. (Contributed by Demur Rumed in bpo-27095(6), and Serhiy Storchaka in bpo-27213(7), bpo-28257(8).) * The new *note SETUP_ANNOTATIONS: 61e. and ‘STORE_ANNOTATION’ opcodes have been added to support the new *note variable annotation: 61f. syntax. (Contributed by Ivan Levkivskyi in bpo-27985(9).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue26647 (2) https://bugs.python.org/issue28050 (3) https://bugs.python.org/issue25483 (4) https://bugs.python.org/issue27078 (5) https://bugs.python.org/issue27140 (6) https://bugs.python.org/issue27095 (7) https://bugs.python.org/issue27213 (8) https://bugs.python.org/issue28257 (9) https://bugs.python.org/issue27985  File: python.info, Node: Notable changes in Python 3 6 2, Next: Notable changes in Python 3 6 4, Prev: Porting to Python 3 6, Up: What’s New In Python 3 6 1.3.12 Notable changes in Python 3.6.2 -------------------------------------- * Menu: * New make regen-all build target:: * Removal of make touch build target::  File: python.info, Node: New make regen-all build target, Next: Removal of make touch build target, Up: Notable changes in Python 3 6 2 1.3.12.1 New ‘make regen-all’ build target .......................................... To simplify cross-compilation, and to ensure that CPython can reliably be compiled without requiring an existing version of Python to already be available, the autotools-based build system no longer attempts to implicitly recompile generated files based on file modification times. Instead, a new ‘make regen-all’ command has been added to force regeneration of these files when desired (e.g. after an initial version of Python has already been built based on the pregenerated versions). More selective regeneration targets are also defined - see Makefile.pre.in(1) for details. (Contributed by Victor Stinner in bpo-23404(2).) New in version 3.6.2. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Makefile.pre.in (2) https://bugs.python.org/issue23404  File: python.info, Node: Removal of make touch build target, Prev: New make regen-all build target, Up: Notable changes in Python 3 6 2 1.3.12.2 Removal of ‘make touch’ build target ............................................. The ‘make touch’ build target previously used to request implicit regeneration of generated files by updating their modification times has been removed. It has been replaced by the new ‘make regen-all’ target. (Contributed by Victor Stinner in bpo-23404(1).) Changed in version 3.6.2. ---------- Footnotes ---------- (1) https://bugs.python.org/issue23404  File: python.info, Node: Notable changes in Python 3 6 4, Next: Notable changes in Python 3 6 5, Prev: Notable changes in Python 3 6 2, Up: What’s New In Python 3 6 1.3.13 Notable changes in Python 3.6.4 -------------------------------------- The ‘PyExc_RecursionErrorInst’ singleton that was part of the public API has been removed as its members being never cleared may cause a segfault during finalization of the interpreter. (Contributed by Xavier de Gaye in bpo-22898(1) and bpo-30697(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22898 (2) https://bugs.python.org/issue30697  File: python.info, Node: Notable changes in Python 3 6 5, Next: Notable changes in Python 3 6 7, Prev: Notable changes in Python 3 6 4, Up: What’s New In Python 3 6 1.3.14 Notable changes in Python 3.6.5 -------------------------------------- The *note locale.localeconv(): 48a. function now sets temporarily the ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale in some cases. (Contributed by Victor Stinner in bpo-31900(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue31900  File: python.info, Node: Notable changes in Python 3 6 7, Next: Notable changes in Python 3 6 10, Prev: Notable changes in Python 3 6 5, Up: What’s New In Python 3 6 1.3.15 Notable changes in Python 3.6.7 -------------------------------------- In 3.6.7 the *note tokenize: 111. module now implicitly emits a ‘NEWLINE’ token when provided with input that does not have a trailing new line. This behavior now matches what the C tokenizer does internally. (Contributed by Ammar Askar in bpo-33899(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue33899  File: python.info, Node: Notable changes in Python 3 6 10, Next: Notable changes in Python 3 6 13, Prev: Notable changes in Python 3 6 7, Up: What’s New In Python 3 6 1.3.16 Notable changes in Python 3.6.10 --------------------------------------- Due to significant security concerns, the `reuse_address' parameter of *note asyncio.loop.create_datagram_endpoint(): 2e7. is no longer supported. This is because of the behavior of the socket option ‘SO_REUSEADDR’ in UDP. For more details, see the documentation for ‘loop.create_datagram_endpoint()’. (Contributed by Kyle Stanley, Antoine Pitrou, and Yury Selivanov in bpo-37228(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue37228  File: python.info, Node: Notable changes in Python 3 6 13, Prev: Notable changes in Python 3 6 10, Up: What’s New In Python 3 6 1.3.17 Notable changes in Python 3.6.13 --------------------------------------- Earlier Python versions allowed using both ‘;’ and ‘&’ as query parameter separators in *note urllib.parse.parse_qs(): 2eb. and *note urllib.parse.parse_qsl(): 2ec. Due to security concerns, and to conform with newer W3C recommendations, this has been changed to allow only a single separator key, with ‘&’ as the default. This change also affects *note cgi.parse(): 2ed. and *note cgi.parse_multipart(): 2ee. as they use the affected functions internally. For more details, please see their respective documentation. (Contributed by Adam Goldschmidt, Senthil Kumaran and Ken Jin in bpo-42967(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue42967  File: python.info, Node: What’s New In Python 3 5, Next: What’s New In Python 3 4, Prev: What’s New In Python 3 6, Up: What’s New in Python 1.4 What’s New In Python 3.5 ============================ Editors: Elvis Pranskevichus <>, Yury Selivanov <> This article explains the new features in Python 3.5, compared to 3.4. Python 3.5 was released on September 13, 2015.  See the changelog(1) for a full list of changes. See also ........ PEP 478(2) - Python 3.5 Release Schedule * Menu: * Summary – Release highlights: Summary – Release highlights<3>. * New Features: New Features<4>. * Other Language Changes: Other Language Changes<4>. * New Modules: New Modules<4>. * Improved Modules: Improved Modules<4>. * Other module-level changes:: * Optimizations: Optimizations<4>. * Build and C API Changes: Build and C API Changes<3>. * Deprecated: Deprecated<3>. * Removed: Removed<2>. * Porting to Python 3.5: Porting to Python 3 5. * Notable changes in Python 3.5.4: Notable changes in Python 3 5 4. ---------- Footnotes ---------- (1) https://docs.python.org/3.5/whatsnew/changelog.html (2) https://www.python.org/dev/peps/pep-0478  File: python.info, Node: Summary – Release highlights<3>, Next: New Features<4>, Up: What’s New In Python 3 5 1.4.1 Summary – Release highlights ---------------------------------- New syntax features: * *note PEP 492: 62b, coroutines with async and await syntax. * *note PEP 465: 62c, a new matrix multiplication operator: ‘a @ b’. * *note PEP 448: 62d, additional unpacking generalizations. New library modules: * *note typing: 119.: *note PEP 484 – Type Hints: 62e. * *note zipapp: 141.: *note PEP 441 Improving Python ZIP Application Support: 62f. New built-in features: * ‘bytes % args’, ‘bytearray % args’: *note PEP 461: 630. – Adding ‘%’ formatting to bytes and bytearray. * New *note bytes.hex(): 631, *note bytearray.hex(): 632. and *note memoryview.hex(): 633. methods. (Contributed by Arnon Yaari in bpo-9951(1).) * *note memoryview: 25c. now supports tuple indexing (including multi-dimensional). (Contributed by Antoine Pitrou in bpo-23632(2).) * Generators have a new ‘gi_yieldfrom’ attribute, which returns the object being iterated by ‘yield from’ expressions. (Contributed by Benno Leslie and Yury Selivanov in bpo-24450(3).) * A new *note RecursionError: 634. exception is now raised when maximum recursion depth is reached. (Contributed by Georg Brandl in bpo-19235(4).) CPython implementation improvements: * When the ‘LC_TYPE’ locale is the POSIX locale (‘C’ locale), *note sys.stdin: 30d. and *note sys.stdout: 30e. now use the ‘surrogateescape’ error handler, instead of the ‘strict’ error handler. (Contributed by Victor Stinner in bpo-19977(5).) * ‘.pyo’ files are no longer used and have been replaced by a more flexible scheme that includes the optimization level explicitly in ‘.pyc’ name. (See *note PEP 488 overview: 635.) * Builtin and extension modules are now initialized in a multi-phase process, which is similar to how Python modules are loaded. (See *note PEP 489 overview: 636.) Significant improvements in the standard library: * *note collections.OrderedDict: 1b9. is now *note implemented in C: 637, which makes it 4 to 100 times faster. * The *note ssl: f3. module gained *note support for Memory BIO: 638, which decouples SSL protocol handling from network IO. * The new *note os.scandir(): 25f. function provides a *note better and significantly faster way: 639. of directory traversal. * *note functools.lru_cache(): 1c7. has been mostly *note reimplemented in C: 63a, yielding much better performance. * The new *note subprocess.run(): 3ed. function provides a *note streamlined way to run subprocesses: 63b. * The *note traceback: 113. module has been significantly *note enhanced: 63c. for improved performance and developer convenience. Security improvements: * SSLv3 is now disabled throughout the standard library. It can still be enabled by instantiating a *note ssl.SSLContext: 3e4. manually. (See bpo-22638(6) for more details; this change was backported to CPython 3.4 and 2.7.) * HTTP cookie parsing is now stricter, in order to protect against potential injection attacks. (Contributed by Antoine Pitrou in bpo-22796(7).) Windows improvements: * A new installer for Windows has replaced the old MSI. See *note Using Python on Windows: 2d9. for more information. * Windows builds now use Microsoft Visual C++ 14.0, and extension modules should use the same. Please read on for a comprehensive list of user-facing changes, including many other smaller improvements, CPython optimizations, deprecations, and potential porting issues. ---------- Footnotes ---------- (1) https://bugs.python.org/issue9951 (2) https://bugs.python.org/issue23632 (3) https://bugs.python.org/issue24450 (4) https://bugs.python.org/issue19235 (5) https://bugs.python.org/issue19977 (6) https://bugs.python.org/issue22638 (7) https://bugs.python.org/issue22796  File: python.info, Node: New Features<4>, Next: Other Language Changes<4>, Prev: Summary – Release highlights<3>, Up: What’s New In Python 3 5 1.4.2 New Features ------------------ * Menu: * PEP 492 - Coroutines with async and await syntax:: * PEP 465 - A dedicated infix operator for matrix multiplication:: * PEP 448 - Additional Unpacking Generalizations:: * PEP 461 - percent formatting support for bytes and bytearray:: * PEP 484 - Type Hints:: * PEP 471 - os.scandir() function – a better and faster directory iterator: PEP 471 - os scandir function – a better and faster directory iterator. * PEP 475; Retry system calls failing with EINTR: PEP 475 Retry system calls failing with EINTR. * PEP 479; Change StopIteration handling inside generators: PEP 479 Change StopIteration handling inside generators. * PEP 485; A function for testing approximate equality: PEP 485 A function for testing approximate equality. * PEP 486; Make the Python Launcher aware of virtual environments: PEP 486 Make the Python Launcher aware of virtual environments. * PEP 488; Elimination of PYO files: PEP 488 Elimination of PYO files. * PEP 489; Multi-phase extension module initialization: PEP 489 Multi-phase extension module initialization.  File: python.info, Node: PEP 492 - Coroutines with async and await syntax, Next: PEP 465 - A dedicated infix operator for matrix multiplication, Up: New Features<4> 1.4.2.1 PEP 492 - Coroutines with async and await syntax ........................................................ PEP 492(1) greatly improves support for asynchronous programming in Python by adding *note awaitable objects: 519, *note coroutine functions: 63f, *note asynchronous iteration: 640, and *note asynchronous context managers: 641. Coroutine functions are declared using the new *note async def: 284. syntax: >>> async def coro(): ... return 'spam' Inside a coroutine function, the new *note await: 1a3. expression can be used to suspend coroutine execution until the result is available. Any object can be `awaited', as long as it implements the *note awaitable: 519. protocol by defining the *note __await__(): 642. method. PEP 492 also adds *note async for: 2e3. statement for convenient iteration over asynchronous iterables. An example of a rudimentary HTTP client written using the new syntax: import asyncio async def http_get(domain): reader, writer = await asyncio.open_connection(domain, 80) writer.write(b'\r\n'.join([ b'GET / HTTP/1.1', b'Host: %b' % domain.encode('latin-1'), b'Connection: close', b'', b'' ])) async for line in reader: print('>>>', line) writer.close() loop = asyncio.get_event_loop() try: loop.run_until_complete(http_get('example.com')) finally: loop.close() Similarly to asynchronous iteration, there is a new syntax for asynchronous context managers. The following script: import asyncio async def coro(name, lock): print('coro {}: waiting for lock'.format(name)) async with lock: print('coro {}: holding the lock'.format(name)) await asyncio.sleep(1) print('coro {}: releasing the lock'.format(name)) loop = asyncio.get_event_loop() lock = asyncio.Lock() coros = asyncio.gather(coro(1, lock), coro(2, lock)) try: loop.run_until_complete(coros) finally: loop.close() will output: coro 2: waiting for lock coro 2: holding the lock coro 1: waiting for lock coro 2: releasing the lock coro 1: holding the lock coro 1: releasing the lock Note that both *note async for: 2e3. and *note async with: 643. can only be used inside a coroutine function declared with *note async def: 284. Coroutine functions are intended to be run inside a compatible event loop, such as the *note asyncio loop: 644. Note: Changed in version 3.5.2: Starting with CPython 3.5.2, ‘__aiter__’ can directly return *note asynchronous iterators: 645. Returning an *note awaitable: 519. object will result in a *note PendingDeprecationWarning: 279. See more details in the *note Asynchronous Iterators: 646. documentation section. See also ........ PEP 492(2) – Coroutines with async and await syntax PEP written and implemented by Yury Selivanov. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0492 (2) https://www.python.org/dev/peps/pep-0492  File: python.info, Node: PEP 465 - A dedicated infix operator for matrix multiplication, Next: PEP 448 - Additional Unpacking Generalizations, Prev: PEP 492 - Coroutines with async and await syntax, Up: New Features<4> 1.4.2.2 PEP 465 - A dedicated infix operator for matrix multiplication ...................................................................... PEP 465(1) adds the ‘@’ infix operator for matrix multiplication. Currently, no builtin Python types implement the new operator, however, it can be implemented by defining *note __matmul__(): 648, *note __rmatmul__(): 649, and *note __imatmul__(): 64a. for regular, reflected, and in-place matrix multiplication. The semantics of these methods is similar to that of methods defining other infix arithmetic operators. Matrix multiplication is a notably common operation in many fields of mathematics, science, engineering, and the addition of ‘@’ allows writing cleaner code: S = (H @ beta - r).T @ inv(H @ V @ H.T) @ (H @ beta - r) instead of: S = dot((dot(H, beta) - r).T, dot(inv(dot(dot(H, V), H.T)), dot(H, beta) - r)) NumPy 1.10 has support for the new operator: >>> import numpy >>> x = numpy.ones(3) >>> x array([ 1., 1., 1.]) >>> m = numpy.eye(3) >>> m array([[ 1., 0., 0.], [ 0., 1., 0.], [ 0., 0., 1.]]) >>> x @ m array([ 1., 1., 1.]) See also ........ PEP 465(2) – A dedicated infix operator for matrix multiplication PEP written by Nathaniel J. Smith; implemented by Benjamin Peterson. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0465 (2) https://www.python.org/dev/peps/pep-0465  File: python.info, Node: PEP 448 - Additional Unpacking Generalizations, Next: PEP 461 - percent formatting support for bytes and bytearray, Prev: PEP 465 - A dedicated infix operator for matrix multiplication, Up: New Features<4> 1.4.2.3 PEP 448 - Additional Unpacking Generalizations ...................................................... PEP 448(1) extends the allowed uses of the ‘*’ iterable unpacking operator and ‘**’ dictionary unpacking operator. It is now possible to use an arbitrary number of unpackings in *note function calls: 64c.: >>> print(*[1], *[2], 3, *[4, 5]) 1 2 3 4 5 >>> def fn(a, b, c, d): ... print(a, b, c, d) ... >>> fn(**{'a': 1, 'c': 3}, **{'b': 2, 'd': 4}) 1 2 3 4 Similarly, tuple, list, set, and dictionary displays allow multiple unpackings (see *note Expression lists: 64d. and *note Dictionary displays: 64e.): >>> *range(4), 4 (0, 1, 2, 3, 4) >>> [*range(4), 4] [0, 1, 2, 3, 4] >>> {*range(4), 4, *(5, 6, 7)} {0, 1, 2, 3, 4, 5, 6, 7} >>> {'x': 1, **{'y': 2}} {'x': 1, 'y': 2} See also ........ PEP 448(2) – Additional Unpacking Generalizations PEP written by Joshua Landau; implemented by Neil Girdhar, Thomas Wouters, and Joshua Landau. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0448 (2) https://www.python.org/dev/peps/pep-0448  File: python.info, Node: PEP 461 - percent formatting support for bytes and bytearray, Next: PEP 484 - Type Hints, Prev: PEP 448 - Additional Unpacking Generalizations, Up: New Features<4> 1.4.2.4 PEP 461 - percent formatting support for bytes and bytearray .................................................................... PEP 461(1) adds support for the ‘%’ *note interpolation operator: 650. to *note bytes: 331. and *note bytearray: 332. While interpolation is usually thought of as a string operation, there are cases where interpolation on ‘bytes’ or ‘bytearrays’ makes sense, and the work needed to make up for this missing functionality detracts from the overall readability of the code. This issue is particularly important when dealing with wire format protocols, which are often a mixture of binary and ASCII compatible text. Examples: >>> b'Hello %b!' % b'World' b'Hello World!' >>> b'x=%i y=%f' % (1, 2.5) b'x=1 y=2.500000' Unicode is not allowed for ‘%b’, but it is accepted by ‘%a’ (equivalent of ‘repr(obj).encode('ascii', 'backslashreplace')’): >>> b'Hello %b!' % 'World' Traceback (most recent call last): File "", line 1, in TypeError: %b requires bytes, or an object that implements __bytes__, not 'str' >>> b'price: %a' % '10€' b"price: '10\\u20ac'" Note that ‘%s’ and ‘%r’ conversion types, although supported, should only be used in codebases that need compatibility with Python 2. See also ........ PEP 461(2) – Adding % formatting to bytes and bytearray PEP written by Ethan Furman; implemented by Neil Schemenauer and Ethan Furman. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0461 (2) https://www.python.org/dev/peps/pep-0461  File: python.info, Node: PEP 484 - Type Hints, Next: PEP 471 - os scandir function – a better and faster directory iterator, Prev: PEP 461 - percent formatting support for bytes and bytearray, Up: New Features<4> 1.4.2.5 PEP 484 - Type Hints ............................ Function annotation syntax has been a Python feature since version 3.0 ( PEP 3107(1)), however the semantics of annotations has been left undefined. Experience has shown that the majority of function annotation uses were to provide type hints to function parameters and return values. It became evident that it would be beneficial for Python users, if the standard library included the base definitions and tools for type annotations. PEP 484(2) introduces a *note provisional module: 348. to provide these standard definitions and tools, along with some conventions for situations where annotations are not available. For example, here is a simple function whose argument and return type are declared in the annotations: def greeting(name: str) -> str: return 'Hello ' + name While these annotations are available at runtime through the usual ‘__annotations__’ attribute, `no automatic type checking happens at runtime'. Instead, it is assumed that a separate off-line type checker (e.g. mypy(3)) will be used for on-demand source code analysis. The type system supports unions, generic types, and a special type named *note Any: 652. which is consistent with (i.e. assignable to and from) all types. See also ........ * *note typing: 119. module documentation * PEP 484(4) – Type Hints PEP written by Guido van Rossum, Jukka Lehtosalo, and Łukasz Langa; implemented by Guido van Rossum. * PEP 483(5) – The Theory of Type Hints PEP written by Guido van Rossum ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3107 (2) https://www.python.org/dev/peps/pep-0484 (3) http://mypy-lang.org (4) https://www.python.org/dev/peps/pep-0484 (5) https://www.python.org/dev/peps/pep-0483  File: python.info, Node: PEP 471 - os scandir function – a better and faster directory iterator, Next: PEP 475 Retry system calls failing with EINTR, Prev: PEP 484 - Type Hints, Up: New Features<4> 1.4.2.6 PEP 471 - os.scandir() function – a better and faster directory iterator ................................................................................ PEP 471(1) adds a new directory iteration function, *note os.scandir(): 25f, to the standard library. Additionally, *note os.walk(): 654. is now implemented using ‘scandir’, which makes it 3 to 5 times faster on POSIX systems and 7 to 20 times faster on Windows systems. This is largely achieved by greatly reducing the number of calls to *note os.stat(): 1f1. required to walk a directory tree. Additionally, ‘scandir’ returns an iterator, as opposed to returning a list of file names, which improves memory efficiency when iterating over very large directories. The following example shows a simple use of *note os.scandir(): 25f. to display all the files (excluding directories) in the given `path' that don’t start with ‘'.'’. The *note entry.is_file(): 655. call will generally not make an additional system call: for entry in os.scandir(path): if not entry.name.startswith('.') and entry.is_file(): print(entry.name) See also ........ PEP 471(2) – os.scandir() function – a better and faster directory iterator PEP written and implemented by Ben Hoyt with the help of Victor Stinner. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0471 (2) https://www.python.org/dev/peps/pep-0471  File: python.info, Node: PEP 475 Retry system calls failing with EINTR, Next: PEP 479 Change StopIteration handling inside generators, Prev: PEP 471 - os scandir function – a better and faster directory iterator, Up: New Features<4> 1.4.2.7 PEP 475: Retry system calls failing with EINTR ...................................................... An *note errno.EINTR: 658. error code is returned whenever a system call, that is waiting for I/O, is interrupted by a signal. Previously, Python would raise *note InterruptedError: 659. in such cases. This meant that, when writing a Python application, the developer had two choices: 1. Ignore the ‘InterruptedError’. 2. Handle the ‘InterruptedError’ and attempt to restart the interrupted system call at every call site. The first option makes an application fail intermittently. The second option adds a large amount of boilerplate that makes the code nearly unreadable. Compare: print("Hello World") and: while True: try: print("Hello World") break except InterruptedError: continue PEP 475(1) implements automatic retry of system calls on ‘EINTR’. This removes the burden of dealing with ‘EINTR’ or *note InterruptedError: 659. in user code in most situations and makes Python programs, including the standard library, more robust. Note that the system call is only retried if the signal handler does not raise an exception. Below is a list of functions which are now retried when interrupted by a signal: * *note open(): 4f0. and *note io.open(): 65a.; * functions of the *note faulthandler: 7d. module; * *note os: c4. functions: *note fchdir(): 65b, *note fchmod(): 65c, *note fchown(): 65d, *note fdatasync(): 65e, *note fstat(): 65f, *note fstatvfs(): 660, *note fsync(): 661, *note ftruncate(): 662, *note mkfifo(): 663, *note mknod(): 664, *note open(): 665, *note posix_fadvise(): 666, *note posix_fallocate(): 667, *note pread(): 3b9, *note pwrite(): 3bc, *note read(): 668, *note readv(): 3b8, *note sendfile(): 359, *note wait3(): 669, *note wait4(): 66a, *note wait(): 66b, *note waitid(): 66c, *note waitpid(): 66d, *note write(): 66e, *note writev(): 3bb.; * special cases: *note os.close(): 3d2. and *note os.dup2(): 3be. now ignore *note EINTR: 658. errors; the syscall is not retried (see the PEP for the rationale); * *note select: e5. functions: *note devpoll.poll(): 66f, *note epoll.poll(): 670, *note kqueue.control(): 671, *note poll.poll(): 672, *note select(): 673.; * methods of the *note socket: 674. class: *note accept(): 675, *note connect(): 676. (except for non-blocking sockets), *note recv(): 677, *note recvfrom(): 678, *note recvmsg(): 679, *note send(): 67a, *note sendall(): 67b, *note sendmsg(): 67c, *note sendto(): 67d.; * *note signal.sigtimedwait(): 67e. and *note signal.sigwaitinfo(): 67f.; * *note time.sleep(): 680. See also ........ PEP 475(2) – Retry system calls failing with EINTR PEP and implementation written by Charles-François Natali and Victor Stinner, with the help of Antoine Pitrou (the French connection). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0475 (2) https://www.python.org/dev/peps/pep-0475  File: python.info, Node: PEP 479 Change StopIteration handling inside generators, Next: PEP 485 A function for testing approximate equality, Prev: PEP 475 Retry system calls failing with EINTR, Up: New Features<4> 1.4.2.8 PEP 479: Change StopIteration handling inside generators ................................................................ The interaction of generators and *note StopIteration: 486. in Python 3.4 and earlier was sometimes surprising, and could conceal obscure bugs. Previously, ‘StopIteration’ raised accidentally inside a generator function was interpreted as the end of the iteration by the loop construct driving the generator. PEP 479(1) changes the behavior of generators: when a ‘StopIteration’ exception is raised inside a generator, it is replaced with a *note RuntimeError: 2ba. before it exits the generator frame. The main goal of this change is to ease debugging in the situation where an unguarded *note next(): 682. call raises ‘StopIteration’ and causes the iteration controlled by the generator to terminate silently. This is particularly pernicious in combination with the ‘yield from’ construct. This is a backwards incompatible change, so to enable the new behavior, a *note __future__: 683. import is necessary: >>> from __future__ import generator_stop >>> def gen(): ... next(iter([])) ... yield ... >>> next(gen()) Traceback (most recent call last): File "", line 2, in gen StopIteration The above exception was the direct cause of the following exception: Traceback (most recent call last): File "", line 1, in RuntimeError: generator raised StopIteration Without a ‘__future__’ import, a *note PendingDeprecationWarning: 279. will be raised whenever a *note StopIteration: 486. exception is raised inside a generator. See also ........ PEP 479(2) – Change StopIteration handling inside generators PEP written by Chris Angelico and Guido van Rossum. Implemented by Chris Angelico, Yury Selivanov and Nick Coghlan. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0479 (2) https://www.python.org/dev/peps/pep-0479  File: python.info, Node: PEP 485 A function for testing approximate equality, Next: PEP 486 Make the Python Launcher aware of virtual environments, Prev: PEP 479 Change StopIteration handling inside generators, Up: New Features<4> 1.4.2.9 PEP 485: A function for testing approximate equality ............................................................ PEP 485(1) adds the *note math.isclose(): 686. and *note cmath.isclose(): 687. functions which tell whether two values are approximately equal or “close” to each other. Whether or not two values are considered close is determined according to given absolute and relative tolerances. Relative tolerance is the maximum allowed difference between ‘isclose’ arguments, relative to the larger absolute value: >>> import math >>> a = 5.0 >>> b = 4.99998 >>> math.isclose(a, b, rel_tol=1e-5) True >>> math.isclose(a, b, rel_tol=1e-6) False It is also possible to compare two values using absolute tolerance, which must be a non-negative value: >>> import math >>> a = 5.0 >>> b = 4.99998 >>> math.isclose(a, b, abs_tol=0.00003) True >>> math.isclose(a, b, abs_tol=0.00001) False See also ........ PEP 485(2) – A function for testing approximate equality PEP written by Christopher Barker; implemented by Chris Barker and Tal Einat. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0485 (2) https://www.python.org/dev/peps/pep-0485  File: python.info, Node: PEP 486 Make the Python Launcher aware of virtual environments, Next: PEP 488 Elimination of PYO files, Prev: PEP 485 A function for testing approximate equality, Up: New Features<4> 1.4.2.10 PEP 486: Make the Python Launcher aware of virtual environments ........................................................................ PEP 486(1) makes the Windows launcher (see PEP 397(2)) aware of an active virtual environment. When the default interpreter would be used and the ‘VIRTUAL_ENV’ environment variable is set, the interpreter in the virtual environment will be used. See also ........ PEP 486(3) – Make the Python Launcher aware of virtual environments PEP written and implemented by Paul Moore. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0486 (2) https://www.python.org/dev/peps/pep-0397 (3) https://www.python.org/dev/peps/pep-0486  File: python.info, Node: PEP 488 Elimination of PYO files, Next: PEP 489 Multi-phase extension module initialization, Prev: PEP 486 Make the Python Launcher aware of virtual environments, Up: New Features<4> 1.4.2.11 PEP 488: Elimination of PYO files .......................................... PEP 488(1) does away with the concept of ‘.pyo’ files. This means that ‘.pyc’ files represent both unoptimized and optimized bytecode. To prevent the need to constantly regenerate bytecode files, ‘.pyc’ files now have an optional ‘opt-’ tag in their name when the bytecode is optimized. This has the side-effect of no more bytecode file name clashes when running under either *note -O: 68b. or *note -OO: 68c. Consequently, bytecode files generated from *note -O: 68b, and *note -OO: 68c. may now exist simultaneously. *note importlib.util.cache_from_source(): 557. has an updated API to help with this change. See also ........ PEP 488(2) – Elimination of PYO files PEP written and implemented by Brett Cannon. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0488 (2) https://www.python.org/dev/peps/pep-0488  File: python.info, Node: PEP 489 Multi-phase extension module initialization, Prev: PEP 488 Elimination of PYO files, Up: New Features<4> 1.4.2.12 PEP 489: Multi-phase extension module initialization ............................................................. PEP 489(1) updates extension module initialization to take advantage of the two step module loading mechanism introduced by PEP 451(2) in Python 3.4. This change brings the import semantics of extension modules that opt-in to using the new mechanism much closer to those of Python source and bytecode modules, including the ability to use any valid identifier as a module name, rather than being restricted to ASCII. See also ........ PEP 489(3) – Multi-phase extension module initialization PEP written by Petr Viktorin, Stefan Behnel, and Nick Coghlan; implemented by Petr Viktorin. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0489 (2) https://www.python.org/dev/peps/pep-0451 (3) https://www.python.org/dev/peps/pep-0489  File: python.info, Node: Other Language Changes<4>, Next: New Modules<4>, Prev: New Features<4>, Up: What’s New In Python 3 5 1.4.3 Other Language Changes ---------------------------- Some smaller changes made to the core Python language are: * Added the ‘"namereplace"’ error handlers. The ‘"backslashreplace"’ error handlers now work with decoding and translating. (Contributed by Serhiy Storchaka in bpo-19676(1) and bpo-22286(2).) * The *note -b: 415. option now affects comparisons of *note bytes: 331. with *note int: 184. (Contributed by Serhiy Storchaka in bpo-23681(3).) * New Kazakh ‘kz1048’ and Tajik ‘koi8_t’ *note codecs: 68f. (Contributed by Serhiy Storchaka in bpo-22682(4) and bpo-22681(5).) * Property docstrings are now writable. This is especially useful for *note collections.namedtuple(): 1b7. docstrings. (Contributed by Berker Peksag in bpo-24064(6).) * Circular imports involving relative imports are now supported. (Contributed by Brett Cannon and Antoine Pitrou in bpo-17636(7).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19676 (2) https://bugs.python.org/issue22286 (3) https://bugs.python.org/issue23681 (4) https://bugs.python.org/issue22682 (5) https://bugs.python.org/issue22681 (6) https://bugs.python.org/issue24064 (7) https://bugs.python.org/issue17636  File: python.info, Node: New Modules<4>, Next: Improved Modules<4>, Prev: Other Language Changes<4>, Up: What’s New In Python 3 5 1.4.4 New Modules ----------------- * Menu: * typing: typing<3>. * zipapp: zipapp<2>.  File: python.info, Node: typing<3>, Next: zipapp<2>, Up: New Modules<4> 1.4.4.1 typing .............. The new *note typing: 119. *note provisional: 348. module provides standard definitions and tools for function type annotations. See *note Type Hints: 62e. for more information.  File: python.info, Node: zipapp<2>, Prev: typing<3>, Up: New Modules<4> 1.4.4.2 zipapp .............. The new *note zipapp: 141. module (specified in PEP 441(1)) provides an API and command line tool for creating executable Python Zip Applications, which were introduced in Python 2.6 in bpo-1739468(2), but which were not well publicized, either at the time or since. With the new module, bundling your application is as simple as putting all the files, including a ‘__main__.py’ file, into a directory ‘myapp’ and running: $ python -m zipapp myapp $ python myapp.pyz The module implementation has been contributed by Paul Moore in bpo-23491(3). See also ........ PEP 441(4) – Improving Python ZIP Application Support ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0441 (2) https://bugs.python.org/issue1739468 (3) https://bugs.python.org/issue23491 (4) https://www.python.org/dev/peps/pep-0441  File: python.info, Node: Improved Modules<4>, Next: Other module-level changes, Prev: New Modules<4>, Up: What’s New In Python 3 5 1.4.5 Improved Modules ---------------------- * Menu: * argparse: argparse<2>. * asyncio: asyncio<5>. * bz2:: * cgi:: * cmath: cmath<2>. * code:: * collections: collections<5>. * collections.abc: collections abc. * compileall: compileall<2>. * concurrent.futures: concurrent futures<3>. * configparser:: * contextlib: contextlib<3>. * csv: csv<2>. * curses: curses<2>. * dbm: dbm<4>. * difflib:: * distutils: distutils<4>. * doctest:: * email: email<2>. * enum: enum<4>. * faulthandler: faulthandler<2>. * functools: functools<3>. * glob:: * gzip: gzip<2>. * heapq:: * http:: * http.client: http client<3>. * idlelib and IDLE: idlelib and IDLE<3>. * imaplib:: * imghdr:: * importlib: importlib<5>. * inspect: inspect<3>. * io: io<3>. * ipaddress: ipaddress<2>. * json: json<2>. * linecache:: * locale: locale<3>. * logging: logging<4>. * lzma:: * math: math<4>. * multiprocessing: multiprocessing<4>. * operator:: * os: os<5>. * pathlib: pathlib<4>. * pickle: pickle<3>. * poplib:: * re: re<4>. * readline: readline<2>. * selectors:: * shutil: shutil<2>. * signal: signal<2>. * smtpd:: * smtplib:: * sndhdr:: * socket: socket<5>. * ssl: ssl<6>. * sqlite3: sqlite3<3>. * subprocess: subprocess<3>. * sys: sys<5>. * sysconfig:: * tarfile: tarfile<2>. * threading: threading<3>. * time: time<4>. * timeit: timeit<2>. * tkinter: tkinter<5>. * traceback: traceback<2>. * types: types<2>. * unicodedata: unicodedata<4>. * unittest: unittest<3>. * unittest.mock: unittest mock<3>. * urllib:: * wsgiref:: * xmlrpc: xmlrpc<2>. * xml.sax: xml sax. * zipfile: zipfile<3>.  File: python.info, Node: argparse<2>, Next: asyncio<5>, Up: Improved Modules<4> 1.4.5.1 argparse ................ The *note ArgumentParser: 695. class now allows disabling *note abbreviated usage: 696. of long options by setting *note allow_abbrev: 697. to ‘False’. (Contributed by Jonathan Paugh, Steven Bethard, paul j3 and Daniel Eriksson in bpo-14910(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14910  File: python.info, Node: asyncio<5>, Next: bz2, Prev: argparse<2>, Up: Improved Modules<4> 1.4.5.2 asyncio ............... Since the *note asyncio: a. module is *note provisional: 348, all changes introduced in Python 3.5 have also been backported to Python 3.4.x. Notable changes in the *note asyncio: a. module since Python 3.4.0: * New debugging APIs: *note loop.set_debug(): 699. and *note loop.get_debug(): 69a. methods. (Contributed by Victor Stinner.) * The proactor event loop now supports SSL. (Contributed by Antoine Pitrou and Victor Stinner in bpo-22560(1).) * A new *note loop.is_closed(): 69b. method to check if the event loop is closed. (Contributed by Victor Stinner in bpo-21326(2).) * A new *note loop.create_task(): 1af. to conveniently create and schedule a new *note Task: 1ad. for a coroutine. The ‘create_task’ method is also used by all asyncio functions that wrap coroutines into tasks, such as *note asyncio.wait(): 289, *note asyncio.gather(): 286, etc. (Contributed by Victor Stinner.) * A new *note transport.get_write_buffer_limits(): 69c. method to inquire for `high-' and `low-' water limits of the flow control. (Contributed by Victor Stinner.) * The ‘async()’ function is deprecated in favor of *note ensure_future(): 517. (Contributed by Yury Selivanov.) * New *note loop.set_task_factory(): 69d. and *note loop.get_task_factory(): 69e. methods to customize the task factory that *note loop.create_task(): 1af. method uses. (Contributed by Yury Selivanov.) * New *note Queue.join(): 69f. and *note Queue.task_done(): 6a0. queue methods. (Contributed by Victor Stinner.) * The ‘JoinableQueue’ class was removed, in favor of the *note asyncio.Queue: 290. class. (Contributed by Victor Stinner.) Updates in 3.5.1: * The *note ensure_future(): 517. function and all functions that use it, such as *note loop.run_until_complete(): 518, now accept all kinds of *note awaitable objects: 519. (Contributed by Yury Selivanov.) * New *note run_coroutine_threadsafe(): 51a. function to submit coroutines to event loops from other threads. (Contributed by Vincent Michel.) * New *note Transport.is_closing(): 51b. method to check if the transport is closing or closed. (Contributed by Yury Selivanov.) * The *note loop.create_server(): 35d. method can now accept a list of hosts. (Contributed by Yann Sionneau.) Updates in 3.5.2: * New *note loop.create_future(): 51c. method to create Future objects. This allows alternative event loop implementations, such as uvloop(3), to provide a faster *note asyncio.Future: 443. implementation. (Contributed by Yury Selivanov.) * New *note loop.get_exception_handler(): 51d. method to get the current exception handler. (Contributed by Yury Selivanov.) * New *note StreamReader.readuntil(): 51e. method to read data from the stream until a separator bytes sequence appears. (Contributed by Mark Korenberg.) * The *note loop.create_connection(): 1b2. and *note loop.create_server(): 35d. methods are optimized to avoid calling the system ‘getaddrinfo’ function if the address is already resolved. (Contributed by A. Jesse Jiryu Davis.) * The *note loop.sock_connect(sock, address): 6a1. no longer requires the `address' to be resolved prior to the call. (Contributed by A. Jesse Jiryu Davis.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22560 (2) https://bugs.python.org/issue21326 (3) https://github.com/MagicStack/uvloop  File: python.info, Node: bz2, Next: cgi, Prev: asyncio<5>, Up: Improved Modules<4> 1.4.5.3 bz2 ........... The *note BZ2Decompressor.decompress: 6a3. method now accepts an optional `max_length' argument to limit the maximum size of decompressed data. (Contributed by Nikolaus Rath in bpo-15955(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15955  File: python.info, Node: cgi, Next: cmath<2>, Prev: bz2, Up: Improved Modules<4> 1.4.5.4 cgi ........... The ‘FieldStorage’ class now supports the *note context manager: 568. protocol. (Contributed by Berker Peksag in bpo-20289(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20289  File: python.info, Node: cmath<2>, Next: code, Prev: cgi, Up: Improved Modules<4> 1.4.5.5 cmath ............. A new function *note isclose(): 687. provides a way to test for approximate equality. (Contributed by Chris Barker and Tal Einat in bpo-24270(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24270  File: python.info, Node: code, Next: collections<5>, Prev: cmath<2>, Up: Improved Modules<4> 1.4.5.6 code ............ The *note InteractiveInterpreter.showtraceback(): 6a7. method now prints the full chained traceback, just like the interactive interpreter. (Contributed by Claudiu Popa in bpo-17442(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17442  File: python.info, Node: collections<5>, Next: collections abc, Prev: code, Up: Improved Modules<4> 1.4.5.7 collections ................... The *note OrderedDict: 1b9. class is now implemented in C, which makes it 4 to 100 times faster. (Contributed by Eric Snow in bpo-16991(1).) ‘OrderedDict.items()’, ‘OrderedDict.keys()’, ‘OrderedDict.values()’ views now support *note reversed(): 18e. iteration. (Contributed by Serhiy Storchaka in bpo-19505(2).) The *note deque: 531. class now defines *note index(): 6a9, *note insert(): 6aa, and *note copy(): 6ab, and supports the ‘+’ and ‘*’ operators. This allows deques to be recognized as a *note MutableSequence: 6ac. and improves their substitutability for lists. (Contributed by Raymond Hettinger in bpo-23704(3).) Docstrings produced by *note namedtuple(): 1b7. can now be updated: Point = namedtuple('Point', ['x', 'y']) Point.__doc__ += ': Cartesian coodinate' Point.x.__doc__ = 'abscissa' Point.y.__doc__ = 'ordinate' (Contributed by Berker Peksag in bpo-24064(4).) The *note UserString: 6ad. class now implements the *note __getnewargs__(): 6ae, *note __rmod__(): 6af, *note casefold(): 6b0, *note format_map(): 6b1, *note isprintable(): 6b2, and *note maketrans(): 6b3. methods to match the corresponding methods of *note str: 330. (Contributed by Joe Jevnik in bpo-22189(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16991 (2) https://bugs.python.org/issue19505 (3) https://bugs.python.org/issue23704 (4) https://bugs.python.org/issue24064 (5) https://bugs.python.org/issue22189  File: python.info, Node: collections abc, Next: compileall<2>, Prev: collections<5>, Up: Improved Modules<4> 1.4.5.8 collections.abc ....................... The ‘Sequence.index()’ method now accepts `start' and `stop' arguments to match the corresponding methods of *note tuple: 47e, *note list: 262, etc. (Contributed by Devin Jeanpierre in bpo-23086(1).) A new *note Generator: 6b5. abstract base class. (Contributed by Stefan Behnel in bpo-24018(2).) New *note Awaitable: 6b6, *note Coroutine: 6b7, *note AsyncIterator: 6b8, and *note AsyncIterable: 6b9. abstract base classes. (Contributed by Yury Selivanov in bpo-24184(3).) For earlier Python versions, a backport of the new ABCs is available in an external PyPI package(4). ---------- Footnotes ---------- (1) https://bugs.python.org/issue23086 (2) https://bugs.python.org/issue24018 (3) https://bugs.python.org/issue24184 (4) https://pypi.org/project/backports_abc  File: python.info, Node: compileall<2>, Next: concurrent futures<3>, Prev: collections abc, Up: Improved Modules<4> 1.4.5.9 compileall .................. A new *note compileall: 21. option, ‘-j `N'’, allows running `N' workers simultaneously to perform parallel bytecode compilation. The *note compile_dir(): 372. function has a corresponding ‘workers’ parameter. (Contributed by Claudiu Popa in bpo-16104(1).) Another new option, ‘-r’, allows controlling the maximum recursion level for subdirectories. (Contributed by Claudiu Popa in bpo-19628(2).) The ‘-q’ command line option can now be specified more than once, in which case all output, including errors, will be suppressed. The corresponding ‘quiet’ parameter in *note compile_dir(): 372, *note compile_file(): 6bb, and *note compile_path(): 6bc. can now accept an integer value indicating the level of output suppression. (Contributed by Thomas Kluyver in bpo-21338(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16104 (2) https://bugs.python.org/issue19628 (3) https://bugs.python.org/issue21338  File: python.info, Node: concurrent futures<3>, Next: configparser, Prev: compileall<2>, Up: Improved Modules<4> 1.4.5.10 concurrent.futures ........................... The *note Executor.map(): 6be. method now accepts a `chunksize' argument to allow batching of tasks to improve performance when *note ProcessPoolExecutor(): 2a4. is used. (Contributed by Dan O’Reilly in bpo-11271(1).) The number of workers in the *note ThreadPoolExecutor: 27a. constructor is optional now. The default value is 5 times the number of CPUs. (Contributed by Claudiu Popa in bpo-21527(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11271 (2) https://bugs.python.org/issue21527  File: python.info, Node: configparser, Next: contextlib<3>, Prev: concurrent futures<3>, Up: Improved Modules<4> 1.4.5.11 configparser ..................... *note configparser: 23. now provides a way to customize the conversion of values by specifying a dictionary of converters in the *note ConfigParser: 4aa. constructor, or by defining them as methods in ‘ConfigParser’ subclasses. Converters defined in a parser instance are inherited by its section proxies. Example: >>> import configparser >>> conv = {} >>> conv['list'] = lambda v: [e.strip() for e in v.split() if e.strip()] >>> cfg = configparser.ConfigParser(converters=conv) >>> cfg.read_string(""" ... [s] ... list = a b c d e f g ... """) >>> cfg.get('s', 'list') 'a b c d e f g' >>> cfg.getlist('s', 'list') ['a', 'b', 'c', 'd', 'e', 'f', 'g'] >>> section = cfg['s'] >>> section.getlist('list') ['a', 'b', 'c', 'd', 'e', 'f', 'g'] (Contributed by Łukasz Langa in bpo-18159(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18159  File: python.info, Node: contextlib<3>, Next: csv<2>, Prev: configparser, Up: Improved Modules<4> 1.4.5.12 contextlib ................... The new *note redirect_stderr(): 6c1. *note context manager: 568. (similar to *note redirect_stdout(): 6c2.) makes it easier for utility scripts to handle inflexible APIs that write their output to *note sys.stderr: 30f. and don’t provide any options to redirect it: >>> import contextlib, io, logging >>> f = io.StringIO() >>> with contextlib.redirect_stderr(f): ... logging.warning('warning') ... >>> f.getvalue() 'WARNING:root:warning\n' (Contributed by Berker Peksag in bpo-22389(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22389  File: python.info, Node: csv<2>, Next: curses<2>, Prev: contextlib<3>, Up: Improved Modules<4> 1.4.5.13 csv ............ The *note writerow(): 6c4. method now supports arbitrary iterables, not just sequences. (Contributed by Serhiy Storchaka in bpo-23171(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23171  File: python.info, Node: curses<2>, Next: dbm<4>, Prev: csv<2>, Up: Improved Modules<4> 1.4.5.14 curses ............... The new *note update_lines_cols(): 6c6. function updates the ‘LINES’ and ‘COLS’ environment variables. This is useful for detecting manual screen resizing. (Contributed by Arnon Yaari in bpo-4254(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4254  File: python.info, Node: dbm<4>, Next: difflib, Prev: curses<2>, Up: Improved Modules<4> 1.4.5.15 dbm ............ *note dumb.open: 2bf. always creates a new database when the flag has the value ‘"n"’. (Contributed by Claudiu Popa in bpo-18039(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18039  File: python.info, Node: difflib, Next: distutils<4>, Prev: dbm<4>, Up: Improved Modules<4> 1.4.5.16 difflib ................ The charset of HTML documents generated by *note HtmlDiff.make_file(): 6c9. can now be customized by using a new `charset' keyword-only argument. The default charset of HTML document changed from ‘"ISO-8859-1"’ to ‘"utf-8"’. (Contributed by Berker Peksag in bpo-2052(1).) The *note diff_bytes(): 6ca. function can now compare lists of byte strings. This fixes a regression from Python 2. (Contributed by Terry J. Reedy and Greg Ward in bpo-17445(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2052 (2) https://bugs.python.org/issue17445  File: python.info, Node: distutils<4>, Next: doctest, Prev: difflib, Up: Improved Modules<4> 1.4.5.17 distutils .................. Both the ‘build’ and ‘build_ext’ commands now accept a ‘-j’ option to enable parallel building of extension modules. (Contributed by Antoine Pitrou in bpo-5309(1).) The *note distutils: 39. module now supports ‘xz’ compression, and can be enabled by passing ‘xztar’ as an argument to ‘bdist --format’. (Contributed by Serhiy Storchaka in bpo-16314(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5309 (2) https://bugs.python.org/issue16314  File: python.info, Node: doctest, Next: email<2>, Prev: distutils<4>, Up: Improved Modules<4> 1.4.5.18 doctest ................ The *note DocTestSuite(): 6cd. function returns an empty *note unittest.TestSuite: 6ce. if `module' contains no docstrings, instead of raising *note ValueError: 1fb. (Contributed by Glenn Jones in bpo-15916(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15916  File: python.info, Node: email<2>, Next: enum<4>, Prev: doctest, Up: Improved Modules<4> 1.4.5.19 email .............. A new policy option *note Policy.mangle_from_: 6d0. controls whether or not lines that start with ‘"From "’ in email bodies are prefixed with a ‘">"’ character by generators. The default is ‘True’ for *note compat32: 540. and ‘False’ for all other policies. (Contributed by Milan Oberkirch in bpo-20098(1).) A new *note Message.get_content_disposition(): 6d1. method provides easy access to a canonical value for the ‘Content-Disposition’ header. (Contributed by Abhilash Raj in bpo-21083(2).) A new policy option *note EmailPolicy.utf8: 6d2. can be set to ‘True’ to encode email headers using the UTF-8 charset instead of using encoded words. This allows ‘Messages’ to be formatted according to RFC 6532(3) and used with an SMTP server that supports the RFC 6531(4) ‘SMTPUTF8’ extension. (Contributed by R. David Murray in bpo-24211(5).) The *note mime.text.MIMEText: 6d3. constructor now accepts a *note charset.Charset: 6d4. instance. (Contributed by Claude Paroz and Berker Peksag in bpo-16324(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20098 (2) https://bugs.python.org/issue21083 (3) https://tools.ietf.org/html/rfc6532.html (4) https://tools.ietf.org/html/rfc6531.html (5) https://bugs.python.org/issue24211 (6) https://bugs.python.org/issue16324  File: python.info, Node: enum<4>, Next: faulthandler<2>, Prev: email<2>, Up: Improved Modules<4> 1.4.5.20 enum ............. The *note Enum: 387. callable has a new parameter `start' to specify the initial number of enum values if only `names' are provided: >>> Animal = enum.Enum('Animal', 'cat dog', start=10) >>> Animal.cat >>> Animal.dog (Contributed by Ethan Furman in bpo-21706(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21706  File: python.info, Node: faulthandler<2>, Next: functools<3>, Prev: enum<4>, Up: Improved Modules<4> 1.4.5.21 faulthandler ..................... The *note enable(): 548, *note register(): 6d7, *note dump_traceback(): 6d8. and *note dump_traceback_later(): 6d9. functions now accept file descriptors in addition to file-like objects. (Contributed by Wei Wu in bpo-23566(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23566  File: python.info, Node: functools<3>, Next: glob, Prev: faulthandler<2>, Up: Improved Modules<4> 1.4.5.22 functools .................. Most of the *note lru_cache(): 1c7. machinery is now implemented in C, making it significantly faster. (Contributed by Matt Joiner, Alexey Kachayev, and Serhiy Storchaka in bpo-14373(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14373  File: python.info, Node: glob, Next: gzip<2>, Prev: functools<3>, Up: Improved Modules<4> 1.4.5.23 glob ............. The *note iglob(): 5c7. and *note glob(): 5c6. functions now support recursive search in subdirectories, using the ‘"**"’ pattern. (Contributed by Serhiy Storchaka in bpo-13968(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13968  File: python.info, Node: gzip<2>, Next: heapq, Prev: glob, Up: Improved Modules<4> 1.4.5.24 gzip ............. The `mode' argument of the *note GzipFile: 6dd. constructor now accepts ‘"x"’ to request exclusive creation. (Contributed by Tim Heaney in bpo-19222(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19222  File: python.info, Node: heapq, Next: http, Prev: gzip<2>, Up: Improved Modules<4> 1.4.5.25 heapq .............. Element comparison in *note merge(): 6df. can now be customized by passing a *note key function: 6e0. in a new optional `key' keyword argument, and a new optional `reverse' keyword argument can be used to reverse element comparison: >>> import heapq >>> a = ['9', '777', '55555'] >>> b = ['88', '6666'] >>> list(heapq.merge(a, b, key=len)) ['9', '88', '777', '6666', '55555'] >>> list(heapq.merge(reversed(a), reversed(b), key=len, reverse=True)) ['55555', '6666', '777', '88', '9'] (Contributed by Raymond Hettinger in bpo-13742(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13742  File: python.info, Node: http, Next: http client<3>, Prev: heapq, Up: Improved Modules<4> 1.4.5.26 http ............. A new *note HTTPStatus: 6e2. enum that defines a set of HTTP status codes, reason phrases and long descriptions written in English. (Contributed by Demian Brecht in bpo-21793(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21793  File: python.info, Node: http client<3>, Next: idlelib and IDLE<3>, Prev: http, Up: Improved Modules<4> 1.4.5.27 http.client .................... *note HTTPConnection.getresponse(): 6e4. now raises a *note RemoteDisconnected: 6e5. exception when a remote server connection is closed unexpectedly. Additionally, if a *note ConnectionError: 6e6. (of which ‘RemoteDisconnected’ is a subclass) is raised, the client socket is now closed automatically, and will reconnect on the next request: import http.client conn = http.client.HTTPConnection('www.python.org') for retries in range(3): try: conn.request('GET', '/') resp = conn.getresponse() except http.client.RemoteDisconnected: pass (Contributed by Martin Panter in bpo-3566(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue3566  File: python.info, Node: idlelib and IDLE<3>, Next: imaplib, Prev: http client<3>, Up: Improved Modules<4> 1.4.5.28 idlelib and IDLE ......................... Since idlelib implements the IDLE shell and editor and is not intended for import by other programs, it gets improvements with every release. See ‘Lib/idlelib/NEWS.txt’ for a cumulative list of changes since 3.4.0, as well as changes made in future 3.5.x releases. This file is also available from the IDLE Help ‣ About IDLE dialog.  File: python.info, Node: imaplib, Next: imghdr, Prev: idlelib and IDLE<3>, Up: Improved Modules<4> 1.4.5.29 imaplib ................ The *note IMAP4: 60b. class now supports the *note context manager: 568. protocol. When used in a *note with: 6e9. statement, the IMAP4 ‘LOGOUT’ command will be called automatically at the end of the block. (Contributed by Tarek Ziadé and Serhiy Storchaka in bpo-4972(1).) The *note imaplib: 98. module now supports RFC 5161(2) (ENABLE Extension) and RFC 6855(3) (UTF-8 Support) via the *note IMAP4.enable(): 6ea. method. A new *note IMAP4.utf8_enabled: 6eb. attribute tracks whether or not RFC 6855(4) support is enabled. (Contributed by Milan Oberkirch, R. David Murray, and Maciej Szulik in bpo-21800(5).) The *note imaplib: 98. module now automatically encodes non-ASCII string usernames and passwords using UTF-8, as recommended by the RFCs. (Contributed by Milan Oberkirch in bpo-21800(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4972 (2) https://tools.ietf.org/html/rfc5161.html (3) https://tools.ietf.org/html/rfc6855.html (4) https://tools.ietf.org/html/rfc6855.html (5) https://bugs.python.org/issue21800 (6) https://bugs.python.org/issue21800  File: python.info, Node: imghdr, Next: importlib<5>, Prev: imaplib, Up: Improved Modules<4> 1.4.5.30 imghdr ............... The *note what(): 6ed. function now recognizes the OpenEXR(1) format (contributed by Martin Vignali and Claudiu Popa in bpo-20295(2)), and the WebP(3) format (contributed by Fabrice Aneche and Claudiu Popa in bpo-20197(4).) ---------- Footnotes ---------- (1) http://www.openexr.com (2) https://bugs.python.org/issue20295 (3) https://en.wikipedia.org/wiki/WebP (4) https://bugs.python.org/issue20197  File: python.info, Node: importlib<5>, Next: inspect<3>, Prev: imghdr, Up: Improved Modules<4> 1.4.5.31 importlib .................. The *note util.LazyLoader: 553. class allows for lazy loading of modules in applications where startup time is important. (Contributed by Brett Cannon in bpo-17621(1).) The *note abc.InspectLoader.source_to_code(): 6ef. method is now a static method. This makes it easier to initialize a module object with code compiled from a string by running ‘exec(code, module.__dict__)’. (Contributed by Brett Cannon in bpo-21156(2).) The new *note util.module_from_spec(): 6f0. function is now the preferred way to create a new module. As opposed to creating a *note types.ModuleType: 6f1. instance directly, this new function will set the various import-controlled attributes based on the passed-in spec object. (Contributed by Brett Cannon in bpo-20383(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17621 (2) https://bugs.python.org/issue21156 (3) https://bugs.python.org/issue20383  File: python.info, Node: inspect<3>, Next: io<3>, Prev: importlib<5>, Up: Improved Modules<4> 1.4.5.32 inspect ................ Both the *note Signature: 6f3. and *note Parameter: 6f4. classes are now picklable and hashable. (Contributed by Yury Selivanov in bpo-20726(1) and bpo-20334(2).) A new *note BoundArguments.apply_defaults(): 6f5. method provides a way to set default values for missing arguments: >>> def foo(a, b='ham', *args): pass >>> ba = inspect.signature(foo).bind('spam') >>> ba.apply_defaults() >>> ba.arguments OrderedDict([('a', 'spam'), ('b', 'ham'), ('args', ())]) (Contributed by Yury Selivanov in bpo-24190(3).) A new class method *note Signature.from_callable(): 6f6. makes subclassing of *note Signature: 6f3. easier. (Contributed by Yury Selivanov and Eric Snow in bpo-17373(4).) The *note signature(): 55b. function now accepts a `follow_wrapped' optional keyword argument, which, when set to ‘False’, disables automatic following of ‘__wrapped__’ links. (Contributed by Yury Selivanov in bpo-20691(5).) A set of new functions to inspect *note coroutine functions: 63f. and *note coroutine objects: 1a6. has been added: *note iscoroutine(): 6f7, *note iscoroutinefunction(): 6f8, *note isawaitable(): 6f9, *note getcoroutinelocals(): 6fa, and *note getcoroutinestate(): 6fb. (Contributed by Yury Selivanov in bpo-24017(6) and bpo-24400(7).) The *note stack(): 6fc, *note trace(): 6fd, *note getouterframes(): 6fe, and *note getinnerframes(): 6ff. functions now return a list of named tuples. (Contributed by Daniel Shahaf in bpo-16808(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20726 (2) https://bugs.python.org/issue20334 (3) https://bugs.python.org/issue24190 (4) https://bugs.python.org/issue17373 (5) https://bugs.python.org/issue20691 (6) https://bugs.python.org/issue24017 (7) https://bugs.python.org/issue24400 (8) https://bugs.python.org/issue16808  File: python.info, Node: io<3>, Next: ipaddress<2>, Prev: inspect<3>, Up: Improved Modules<4> 1.4.5.33 io ........... A new *note BufferedIOBase.readinto1(): 701. method, that uses at most one call to the underlying raw stream’s *note RawIOBase.read(): 702. or *note RawIOBase.readinto(): 703. methods. (Contributed by Nikolaus Rath in bpo-20578(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20578  File: python.info, Node: ipaddress<2>, Next: json<2>, Prev: io<3>, Up: Improved Modules<4> 1.4.5.34 ipaddress .................. Both the *note IPv4Network: 3a0. and *note IPv6Network: 39f. classes now accept an ‘(address, netmask)’ tuple argument, so as to easily construct network objects from existing addresses: >>> import ipaddress >>> ipaddress.IPv4Network(('127.0.0.0', 8)) IPv4Network('127.0.0.0/8') >>> ipaddress.IPv4Network(('127.0.0.0', '255.0.0.0')) IPv4Network('127.0.0.0/8') (Contributed by Peter Moody and Antoine Pitrou in bpo-16531(1).) A new ‘reverse_pointer’ attribute for the *note IPv4Network: 3a0. and *note IPv6Network: 39f. classes returns the name of the reverse DNS PTR record: >>> import ipaddress >>> addr = ipaddress.IPv4Address('127.0.0.1') >>> addr.reverse_pointer '1.0.0.127.in-addr.arpa' >>> addr6 = ipaddress.IPv6Address('::1') >>> addr6.reverse_pointer '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa' (Contributed by Leon Weber in bpo-20480(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16531 (2) https://bugs.python.org/issue20480  File: python.info, Node: json<2>, Next: linecache, Prev: ipaddress<2>, Up: Improved Modules<4> 1.4.5.35 json ............. The *note json.tool: a5. command line interface now preserves the order of keys in JSON objects passed in input. The new ‘--sort-keys’ option can be used to sort the keys alphabetically. (Contributed by Berker Peksag in bpo-21650(1).) JSON decoder now raises *note JSONDecodeError: 706. instead of *note ValueError: 1fb. to provide better context information about the error. (Contributed by Serhiy Storchaka in bpo-19361(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21650 (2) https://bugs.python.org/issue19361  File: python.info, Node: linecache, Next: locale<3>, Prev: json<2>, Up: Improved Modules<4> 1.4.5.36 linecache .................. A new *note lazycache(): 708. function can be used to capture information about a non-file-based module to permit getting its lines later via *note getline(): 709. This avoids doing I/O until a line is actually needed, without having to carry the module globals around indefinitely. (Contributed by Robert Collins in bpo-17911(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17911  File: python.info, Node: locale<3>, Next: logging<4>, Prev: linecache, Up: Improved Modules<4> 1.4.5.37 locale ............... A new *note delocalize(): 70b. function can be used to convert a string into a normalized number string, taking the ‘LC_NUMERIC’ settings into account: >>> import locale >>> locale.setlocale(locale.LC_NUMERIC, 'de_DE.UTF-8') 'de_DE.UTF-8' >>> locale.delocalize('1.234,56') '1234.56' >>> locale.setlocale(locale.LC_NUMERIC, 'en_US.UTF-8') 'en_US.UTF-8' >>> locale.delocalize('1,234.56') '1234.56' (Contributed by Cédric Krier in bpo-13918(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13918  File: python.info, Node: logging<4>, Next: lzma, Prev: locale<3>, Up: Improved Modules<4> 1.4.5.38 logging ................ All logging methods (*note Logger: 3a7. *note log(): 70d, *note exception(): 70e, *note critical(): 70f, *note debug(): 710, etc.), now accept exception instances as an `exc_info' argument, in addition to boolean values and exception tuples: >>> import logging >>> try: ... 1/0 ... except ZeroDivisionError as ex: ... logging.error('exception', exc_info=ex) ERROR:root:exception (Contributed by Yury Selivanov in bpo-20537(1).) The *note handlers.HTTPHandler: 711. class now accepts an optional *note ssl.SSLContext: 3e4. instance to configure SSL settings used in an HTTP connection. (Contributed by Alex Gaynor in bpo-22788(2).) The *note handlers.QueueListener: 712. class now takes a `respect_handler_level' keyword argument which, if set to ‘True’, will pass messages to handlers taking handler levels into account. (Contributed by Vinay Sajip.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20537 (2) https://bugs.python.org/issue22788  File: python.info, Node: lzma, Next: math<4>, Prev: logging<4>, Up: Improved Modules<4> 1.4.5.39 lzma ............. The *note LZMADecompressor.decompress(): 714. method now accepts an optional `max_length' argument to limit the maximum size of decompressed data. (Contributed by Martin Panter in bpo-15955(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15955  File: python.info, Node: math<4>, Next: multiprocessing<4>, Prev: lzma, Up: Improved Modules<4> 1.4.5.40 math ............. Two new constants have been added to the *note math: b1. module: *note inf: 528. and *note nan: 529. (Contributed by Mark Dickinson in bpo-23185(1).) A new function *note isclose(): 686. provides a way to test for approximate equality. (Contributed by Chris Barker and Tal Einat in bpo-24270(2).) A new *note gcd(): 716. function has been added. The *note fractions.gcd(): 717. function is now deprecated. (Contributed by Mark Dickinson and Serhiy Storchaka in bpo-22486(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23185 (2) https://bugs.python.org/issue24270 (3) https://bugs.python.org/issue22486  File: python.info, Node: multiprocessing<4>, Next: operator, Prev: math<4>, Up: Improved Modules<4> 1.4.5.41 multiprocessing ........................ *note sharedctypes.synchronized(): 719. objects now support the *note context manager: 568. protocol. (Contributed by Charles-François Natali in bpo-21565(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21565  File: python.info, Node: operator, Next: os<5>, Prev: multiprocessing<4>, Up: Improved Modules<4> 1.4.5.42 operator ................. *note attrgetter(): 71b, *note itemgetter(): 261, and *note methodcaller(): 71c. objects now support pickling. (Contributed by Josh Rosenberg and Serhiy Storchaka in bpo-22955(1).) New *note matmul(): 71d. and *note imatmul(): 71e. functions to perform matrix multiplication. (Contributed by Benjamin Peterson in bpo-21176(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22955 (2) https://bugs.python.org/issue21176  File: python.info, Node: os<5>, Next: pathlib<4>, Prev: operator, Up: Improved Modules<4> 1.4.5.43 os ........... The new *note scandir(): 25f. function returning an iterator of *note DirEntry: 4f1. objects has been added. If possible, *note scandir(): 25f. extracts file attributes while scanning a directory, removing the need to perform subsequent system calls to determine file type or attributes, which may significantly improve performance. (Contributed by Ben Hoyt with the help of Victor Stinner in bpo-22524(1).) On Windows, a new *note stat_result.st_file_attributes: 720. attribute is now available. It corresponds to the ‘dwFileAttributes’ member of the ‘BY_HANDLE_FILE_INFORMATION’ structure returned by ‘GetFileInformationByHandle()’. (Contributed by Ben Hoyt in bpo-21719(2).) The *note urandom(): 4d1. function now uses the ‘getrandom()’ syscall on Linux 3.17 or newer, and ‘getentropy()’ on OpenBSD 5.6 and newer, removing the need to use ‘/dev/urandom’ and avoiding failures due to potential file descriptor exhaustion. (Contributed by Victor Stinner in bpo-22181(3).) New *note get_blocking(): 721. and *note set_blocking(): 722. functions allow getting and setting a file descriptor’s blocking mode (*note O_NONBLOCK: 723.) (Contributed by Victor Stinner in bpo-22054(4).) The *note truncate(): 724. and *note ftruncate(): 662. functions are now supported on Windows. (Contributed by Steve Dower in bpo-23668(5).) There is a new *note os.path.commonpath(): 725. function returning the longest common sub-path of each passed pathname. Unlike the *note os.path.commonprefix(): 726. function, it always returns a valid path: >>> os.path.commonprefix(['/usr/lib', '/usr/local/lib']) '/usr/l' >>> os.path.commonpath(['/usr/lib', '/usr/local/lib']) '/usr' (Contributed by Rafik Draoui and Serhiy Storchaka in bpo-10395(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22524 (2) https://bugs.python.org/issue21719 (3) https://bugs.python.org/issue22181 (4) https://bugs.python.org/issue22054 (5) https://bugs.python.org/issue23668 (6) https://bugs.python.org/issue10395  File: python.info, Node: pathlib<4>, Next: pickle<3>, Prev: os<5>, Up: Improved Modules<4> 1.4.5.44 pathlib ................ The new *note Path.samefile(): 728. method can be used to check whether the path points to the same file as another path, which can be either another *note Path: 201. object, or a string: >>> import pathlib >>> p1 = pathlib.Path('/etc/hosts') >>> p2 = pathlib.Path('/etc/../etc/hosts') >>> p1.samefile(p2) True (Contributed by Vajrasky Kok and Antoine Pitrou in bpo-19775(1).) The *note Path.mkdir(): 729. method now accepts a new optional `exist_ok' argument to match ‘mkdir -p’ and *note os.makedirs(): 3bd. functionality. (Contributed by Berker Peksag in bpo-21539(2).) There is a new *note Path.expanduser(): 72a. method to expand ‘~’ and ‘~user’ prefixes. (Contributed by Serhiy Storchaka and Claudiu Popa in bpo-19776(3).) A new *note Path.home(): 72b. class method can be used to get a *note Path: 201. instance representing the user’s home directory. (Contributed by Victor Salgado and Mayank Tripathi in bpo-19777(4).) New *note Path.write_text(): 72c, *note Path.read_text(): 72d, *note Path.write_bytes(): 72e, *note Path.read_bytes(): 72f. methods to simplify read/write operations on files. The following code snippet will create or rewrite existing file ‘~/spam42’: >>> import pathlib >>> p = pathlib.Path('~/spam42') >>> p.expanduser().write_text('ham') 3 (Contributed by Christopher Welborn in bpo-20218(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19775 (2) https://bugs.python.org/issue21539 (3) https://bugs.python.org/issue19776 (4) https://bugs.python.org/issue19777 (5) https://bugs.python.org/issue20218  File: python.info, Node: pickle<3>, Next: poplib, Prev: pathlib<4>, Up: Improved Modules<4> 1.4.5.45 pickle ............... Nested objects, such as unbound methods or nested classes, can now be pickled using *note pickle protocols: 56e. older than protocol version 4. Protocol version 4 already supports these cases. (Contributed by Serhiy Storchaka in bpo-23611(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23611  File: python.info, Node: poplib, Next: re<4>, Prev: pickle<3>, Up: Improved Modules<4> 1.4.5.46 poplib ............... A new *note POP3.utf8(): 732. command enables RFC 6856(1) (Internationalized Email) support, if a POP server supports it. (Contributed by Milan OberKirch in bpo-21804(2).) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc6856.html (2) https://bugs.python.org/issue21804  File: python.info, Node: re<4>, Next: readline<2>, Prev: poplib, Up: Improved Modules<4> 1.4.5.47 re ........... References and conditional references to groups with fixed length are now allowed in lookbehind assertions: >>> import re >>> pat = re.compile(r'(a|b).(?<=\1)c') >>> pat.match('aac') <_sre.SRE_Match object; span=(0, 3), match='aac'> >>> pat.match('bbc') <_sre.SRE_Match object; span=(0, 3), match='bbc'> (Contributed by Serhiy Storchaka in bpo-9179(1).) The number of capturing groups in regular expressions is no longer limited to 100. (Contributed by Serhiy Storchaka in bpo-22437(2).) The *note sub(): 47b. and *note subn(): 734. functions now replace unmatched groups with empty strings instead of raising an exception. (Contributed by Serhiy Storchaka in bpo-1519638(3).) The *note re.error: 735. exceptions have new attributes, *note msg: 736, *note pattern: 737, *note pos: 738, *note lineno: 739, and *note colno: 73a, that provide better context information about the error: >>> re.compile(""" ... (?x) ... .++ ... """) Traceback (most recent call last): ... sre_constants.error: multiple repeat at position 16 (line 3, column 7) (Contributed by Serhiy Storchaka in bpo-22578(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9179 (2) https://bugs.python.org/issue22437 (3) https://bugs.python.org/issue1519638 (4) https://bugs.python.org/issue22578  File: python.info, Node: readline<2>, Next: selectors, Prev: re<4>, Up: Improved Modules<4> 1.4.5.48 readline ................. A new *note append_history_file(): 73c. function can be used to append the specified number of trailing elements in history to the given file. (Contributed by Bruno Cauet in bpo-22940(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22940  File: python.info, Node: selectors, Next: shutil<2>, Prev: readline<2>, Up: Improved Modules<4> 1.4.5.49 selectors .................. The new *note DevpollSelector: 44e. supports efficient ‘/dev/poll’ polling on Solaris. (Contributed by Giampaolo Rodola’ in bpo-18931(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18931  File: python.info, Node: shutil<2>, Next: signal<2>, Prev: selectors, Up: Improved Modules<4> 1.4.5.50 shutil ............... The *note move(): 25b. function now accepts a `copy_function' argument, allowing, for example, the *note copy(): 259. function to be used instead of the default *note copy2(): 25a. if there is a need to ignore file metadata when moving. (Contributed by Claudiu Popa in bpo-19840(1).) The *note make_archive(): 21b. function now supports the `xztar' format. (Contributed by Serhiy Storchaka in bpo-5411(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19840 (2) https://bugs.python.org/issue5411  File: python.info, Node: signal<2>, Next: smtpd, Prev: shutil<2>, Up: Improved Modules<4> 1.4.5.51 signal ............... On Windows, the *note set_wakeup_fd(): 3ce. function now also supports socket handles. (Contributed by Victor Stinner in bpo-22018(1).) Various ‘SIG*’ constants in the *note signal: ea. module have been converted into *note Enums: 7b. This allows meaningful names to be printed during debugging, instead of integer “magic numbers”. (Contributed by Giampaolo Rodola’ in bpo-21076(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22018 (2) https://bugs.python.org/issue21076  File: python.info, Node: smtpd, Next: smtplib, Prev: signal<2>, Up: Improved Modules<4> 1.4.5.52 smtpd .............. Both the *note SMTPServer: 602. and *note SMTPChannel: 601. classes now accept a `decode_data' keyword argument to determine if the ‘DATA’ portion of the SMTP transaction is decoded using the ‘"utf-8"’ codec or is instead provided to the *note SMTPServer.process_message(): 603. method as a byte string. The default is ‘True’ for backward compatibility reasons, but will change to ‘False’ in Python 3.6. If `decode_data' is set to ‘False’, the ‘process_message’ method must be prepared to accept keyword arguments. (Contributed by Maciej Szulik in bpo-19662(1).) The *note SMTPServer: 602. class now advertises the ‘8BITMIME’ extension ( RFC 6152(2)) if `decode_data' has been set ‘True’. If the client specifies ‘BODY=8BITMIME’ on the ‘MAIL’ command, it is passed to *note SMTPServer.process_message(): 603. via the `mail_options' keyword. (Contributed by Milan Oberkirch and R. David Murray in bpo-21795(3).) The *note SMTPServer: 602. class now also supports the ‘SMTPUTF8’ extension ( RFC 6531(4): Internationalized Email). If the client specified ‘SMTPUTF8 BODY=8BITMIME’ on the ‘MAIL’ command, they are passed to *note SMTPServer.process_message(): 603. via the `mail_options' keyword. It is the responsibility of the ‘process_message’ method to correctly handle the ‘SMTPUTF8’ data. (Contributed by Milan Oberkirch in bpo-21725(5).) It is now possible to provide, directly or via name resolution, IPv6 addresses in the *note SMTPServer: 602. constructor, and have it successfully connect. (Contributed by Milan Oberkirch in bpo-14758(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19662 (2) https://tools.ietf.org/html/rfc6152.html (3) https://bugs.python.org/issue21795 (4) https://tools.ietf.org/html/rfc6531.html (5) https://bugs.python.org/issue21725 (6) https://bugs.python.org/issue14758  File: python.info, Node: smtplib, Next: sndhdr, Prev: smtpd, Up: Improved Modules<4> 1.4.5.53 smtplib ................ A new *note SMTP.auth(): 742. method provides a convenient way to implement custom authentication mechanisms. (Contributed by Milan Oberkirch in bpo-15014(1).) The *note SMTP.set_debuglevel(): 743. method now accepts an additional debuglevel (2), which enables timestamps in debug messages. (Contributed by Gavin Chappell and Maciej Szulik in bpo-16914(2).) Both the *note SMTP.sendmail(): 744. and *note SMTP.send_message(): 745. methods now support RFC 6531(3) (SMTPUTF8). (Contributed by Milan Oberkirch and R. David Murray in bpo-22027(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15014 (2) https://bugs.python.org/issue16914 (3) https://tools.ietf.org/html/rfc6531.html (4) https://bugs.python.org/issue22027  File: python.info, Node: sndhdr, Next: socket<5>, Prev: smtplib, Up: Improved Modules<4> 1.4.5.54 sndhdr ............... The *note what(): 747. and *note whathdr(): 748. functions now return a *note namedtuple(): 1b7. (Contributed by Claudiu Popa in bpo-18615(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18615  File: python.info, Node: socket<5>, Next: ssl<6>, Prev: sndhdr, Up: Improved Modules<4> 1.4.5.55 socket ............... Functions with timeouts now use a monotonic clock, instead of a system clock. (Contributed by Victor Stinner in bpo-22043(1).) A new *note socket.sendfile(): 74a. method allows sending a file over a socket by using the high-performance *note os.sendfile(): 359. function on UNIX, resulting in uploads being from 2 to 3 times faster than when using plain *note socket.send(): 67a. (Contributed by Giampaolo Rodola’ in bpo-17552(2).) The *note socket.sendall(): 67b. method no longer resets the socket timeout every time bytes are received or sent. The socket timeout is now the maximum total duration to send all data. (Contributed by Victor Stinner in bpo-23853(3).) The `backlog' argument of the *note socket.listen(): 74b. method is now optional. By default it is set to *note SOMAXCONN: 74c. or to ‘128’, whichever is less. (Contributed by Charles-François Natali in bpo-21455(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22043 (2) https://bugs.python.org/issue17552 (3) https://bugs.python.org/issue23853 (4) https://bugs.python.org/issue21455  File: python.info, Node: ssl<6>, Next: sqlite3<3>, Prev: socket<5>, Up: Improved Modules<4> 1.4.5.56 ssl ............ * Menu: * Memory BIO Support:: * Application-Layer Protocol Negotiation Support:: * Other Changes::  File: python.info, Node: Memory BIO Support, Next: Application-Layer Protocol Negotiation Support, Up: ssl<6> 1.4.5.57 Memory BIO Support ........................... (Contributed by Geert Jansen in bpo-21965(1).) The new *note SSLObject: 3e3. class has been added to provide SSL protocol support for cases when the network I/O capabilities of *note SSLSocket: 3e2. are not necessary or are suboptimal. ‘SSLObject’ represents an SSL protocol instance, but does not implement any network I/O methods, and instead provides a memory buffer interface. The new *note MemoryBIO: 74f. class can be used to pass data between Python and an SSL protocol instance. The memory BIO SSL support is primarily intended to be used in frameworks implementing asynchronous I/O for which *note SSLSocket: 3e2.’s readiness model (“select/poll”) is inefficient. A new *note SSLContext.wrap_bio(): 3e6. method can be used to create a new ‘SSLObject’ instance. ---------- Footnotes ---------- (1) https://bugs.python.org/issue21965  File: python.info, Node: Application-Layer Protocol Negotiation Support, Next: Other Changes, Prev: Memory BIO Support, Up: ssl<6> 1.4.5.58 Application-Layer Protocol Negotiation Support ....................................................... (Contributed by Benjamin Peterson in bpo-20188(1).) Where OpenSSL support is present, the *note ssl: f3. module now implements the `Application-Layer Protocol Negotiation' TLS extension as described in RFC 7301(2). The new *note SSLContext.set_alpn_protocols(): 751. can be used to specify which protocols a socket should advertise during the TLS handshake. The new *note SSLSocket.selected_alpn_protocol(): 752. returns the protocol that was selected during the TLS handshake. The *note HAS_ALPN: 753. flag indicates whether ALPN support is present. ---------- Footnotes ---------- (1) https://bugs.python.org/issue20188 (2) https://tools.ietf.org/html/rfc7301.html  File: python.info, Node: Other Changes, Prev: Application-Layer Protocol Negotiation Support, Up: ssl<6> 1.4.5.59 Other Changes ...................... There is a new *note SSLSocket.version(): 755. method to query the actual protocol version in use. (Contributed by Antoine Pitrou in bpo-20421(1).) The *note SSLSocket: 3e2. class now implements a ‘SSLSocket.sendfile()’ method. (Contributed by Giampaolo Rodola’ in bpo-17552(2).) The ‘SSLSocket.send()’ method now raises either the *note ssl.SSLWantReadError: 756. or *note ssl.SSLWantWriteError: 757. exception on a non-blocking socket if the operation would block. Previously, it would return ‘0’. (Contributed by Nikolaus Rath in bpo-20951(3).) The *note cert_time_to_seconds(): 758. function now interprets the input time as UTC and not as local time, per RFC 5280(4). Additionally, the return value is always an *note int: 184. (Contributed by Akira Li in bpo-19940(5).) New ‘SSLObject.shared_ciphers()’ and *note SSLSocket.shared_ciphers(): 759. methods return the list of ciphers sent by the client during the handshake. (Contributed by Benjamin Peterson in bpo-23186(6).) The *note SSLSocket.do_handshake(): 75a, *note SSLSocket.read(): 75b, ‘SSLSocket.shutdown()’, and *note SSLSocket.write(): 75c. methods of the *note SSLSocket: 3e2. class no longer reset the socket timeout every time bytes are received or sent. The socket timeout is now the maximum total duration of the method. (Contributed by Victor Stinner in bpo-23853(7).) The *note match_hostname(): 3dc. function now supports matching of IP addresses. (Contributed by Antoine Pitrou in bpo-23239(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20421 (2) https://bugs.python.org/issue17552 (3) https://bugs.python.org/issue20951 (4) https://tools.ietf.org/html/rfc5280.html (5) https://bugs.python.org/issue19940 (6) https://bugs.python.org/issue23186 (7) https://bugs.python.org/issue23853 (8) https://bugs.python.org/issue23239  File: python.info, Node: sqlite3<3>, Next: subprocess<3>, Prev: ssl<6>, Up: Improved Modules<4> 1.4.5.60 sqlite3 ................ The *note Row: 75e. class now fully supports the sequence protocol, in particular *note reversed(): 18e. iteration and slice indexing. (Contributed by Claudiu Popa in bpo-10203(1); by Lucas Sinclair, Jessica McKellar, and Serhiy Storchaka in bpo-13583(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10203 (2) https://bugs.python.org/issue13583  File: python.info, Node: subprocess<3>, Next: sys<5>, Prev: sqlite3<3>, Up: Improved Modules<4> 1.4.5.61 subprocess ................... The new *note run(): 3ed. function has been added. It runs the specified command and returns a *note CompletedProcess: 760. object, which describes a finished process. The new API is more consistent and is the recommended approach to invoking subprocesses in Python code that does not need to maintain compatibility with earlier Python versions. (Contributed by Thomas Kluyver in bpo-23342(1).) Examples: >>> subprocess.run(["ls", "-l"]) # doesn't capture output CompletedProcess(args=['ls', '-l'], returncode=0) >>> subprocess.run("exit 1", shell=True, check=True) Traceback (most recent call last): ... subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1 >>> subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE) CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0, stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n') ---------- Footnotes ---------- (1) https://bugs.python.org/issue23342  File: python.info, Node: sys<5>, Next: sysconfig, Prev: subprocess<3>, Up: Improved Modules<4> 1.4.5.62 sys ............ A new ‘set_coroutine_wrapper()’ function allows setting a global hook that will be called whenever a *note coroutine object: 1a6. is created by an *note async def: 284. function. A corresponding ‘get_coroutine_wrapper()’ can be used to obtain a currently set wrapper. Both functions are *note provisional: 348, and are intended for debugging purposes only. (Contributed by Yury Selivanov in bpo-24017(1).) A new *note is_finalizing(): 762. function can be used to check if the Python interpreter is *note shutting down: 763. (Contributed by Antoine Pitrou in bpo-22696(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24017 (2) https://bugs.python.org/issue22696  File: python.info, Node: sysconfig, Next: tarfile<2>, Prev: sys<5>, Up: Improved Modules<4> 1.4.5.63 sysconfig .................. The name of the user scripts directory on Windows now includes the first two components of the Python version. (Contributed by Paul Moore in bpo-23437(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23437  File: python.info, Node: tarfile<2>, Next: threading<3>, Prev: sysconfig, Up: Improved Modules<4> 1.4.5.64 tarfile ................ The `mode' argument of the *note open(): 766. function now accepts ‘"x"’ to request exclusive creation. (Contributed by Berker Peksag in bpo-21717(1).) The *note TarFile.extractall(): 767. and *note TarFile.extract(): 768. methods now take a keyword argument `numeric_owner'. If set to ‘True’, the extracted files and directories will be owned by the numeric ‘uid’ and ‘gid’ from the tarfile. If set to ‘False’ (the default, and the behavior in versions prior to 3.5), they will be owned by the named user and group in the tarfile. (Contributed by Michael Vogt and Eric Smith in bpo-23193(2).) The *note TarFile.list(): 769. now accepts an optional `members' keyword argument that can be set to a subset of the list returned by *note TarFile.getmembers(): 76a. (Contributed by Serhiy Storchaka in bpo-21549(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21717 (2) https://bugs.python.org/issue23193 (3) https://bugs.python.org/issue21549  File: python.info, Node: threading<3>, Next: time<4>, Prev: tarfile<2>, Up: Improved Modules<4> 1.4.5.65 threading .................. Both the *note Lock.acquire(): 76c. and *note RLock.acquire(): 76d. methods now use a monotonic clock for timeout management. (Contributed by Victor Stinner in bpo-22043(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22043  File: python.info, Node: time<4>, Next: timeit<2>, Prev: threading<3>, Up: Improved Modules<4> 1.4.5.66 time ............. The *note monotonic(): 76f. function is now always available. (Contributed by Victor Stinner in bpo-22043(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue22043  File: python.info, Node: timeit<2>, Next: tkinter<5>, Prev: time<4>, Up: Improved Modules<4> 1.4.5.67 timeit ............... A new command line option ‘-u’ or ‘--unit=`U'’ can be used to specify the time unit for the timer output. Supported options are ‘usec’, ‘msec’, or ‘sec’. (Contributed by Julian Gindi in bpo-18983(1).) The *note timeit(): 771. function has a new `globals' parameter for specifying the namespace in which the code will be running. (Contributed by Ben Roberts in bpo-2527(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18983 (2) https://bugs.python.org/issue2527  File: python.info, Node: tkinter<5>, Next: traceback<2>, Prev: timeit<2>, Up: Improved Modules<4> 1.4.5.68 tkinter ................ The ‘tkinter._fix’ module used for setting up the Tcl/Tk environment on Windows has been replaced by a private function in the ‘_tkinter’ module which makes no permanent changes to environment variables. (Contributed by Zachary Ware in bpo-20035(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20035  File: python.info, Node: traceback<2>, Next: types<2>, Prev: tkinter<5>, Up: Improved Modules<4> 1.4.5.69 traceback .................. New *note walk_stack(): 774. and *note walk_tb(): 775. functions to conveniently traverse frame and traceback objects. (Contributed by Robert Collins in bpo-17911(1).) New lightweight classes: *note TracebackException: 776, *note StackSummary: 777, and *note FrameSummary: 778. (Contributed by Robert Collins in bpo-17911(2).) Both the *note print_tb(): 779. and *note print_stack(): 77a. functions now support negative values for the `limit' argument. (Contributed by Dmitry Kazakov in bpo-22619(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17911 (2) https://bugs.python.org/issue17911 (3) https://bugs.python.org/issue22619  File: python.info, Node: types<2>, Next: unicodedata<4>, Prev: traceback<2>, Up: Improved Modules<4> 1.4.5.70 types .............. A new *note coroutine(): 77c. function to transform *note generator: 457. and *note generator-like: 6b5. objects into *note awaitables: 519. (Contributed by Yury Selivanov in bpo-24017(1).) A new type called *note CoroutineType: 77d, which is used for *note coroutine: 1a6. objects created by *note async def: 284. functions. (Contributed by Yury Selivanov in bpo-24400(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue24017 (2) https://bugs.python.org/issue24400  File: python.info, Node: unicodedata<4>, Next: unittest<3>, Prev: types<2>, Up: Improved Modules<4> 1.4.5.71 unicodedata .................... The *note unicodedata: 11a. module now uses data from Unicode 8.0.0(1). ---------- Footnotes ---------- (1) http://unicode.org/versions/Unicode8.0.0/  File: python.info, Node: unittest<3>, Next: unittest mock<3>, Prev: unicodedata<4>, Up: Improved Modules<4> 1.4.5.72 unittest ................. The *note TestLoader.loadTestsFromModule(): 780. method now accepts a keyword-only argument `pattern' which is passed to ‘load_tests’ as the third argument. Found packages are now checked for ‘load_tests’ regardless of whether their path matches `pattern', because it is impossible for a package name to match the default pattern. (Contributed by Robert Collins and Barry A. Warsaw in bpo-16662(1).) Unittest discovery errors now are exposed in the *note TestLoader.errors: 781. attribute of the *note TestLoader: 782. instance. (Contributed by Robert Collins in bpo-19746(2).) A new command line option ‘--locals’ to show local variables in tracebacks. (Contributed by Robert Collins in bpo-22936(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16662 (2) https://bugs.python.org/issue19746 (3) https://bugs.python.org/issue22936  File: python.info, Node: unittest mock<3>, Next: urllib, Prev: unittest<3>, Up: Improved Modules<4> 1.4.5.73 unittest.mock ...................... The *note Mock: 249. class has the following improvements: * The class constructor has a new `unsafe' parameter, which causes mock objects to raise *note AttributeError: 39b. on attribute names starting with ‘"assert"’. (Contributed by Kushal Das in bpo-21238(1).) * A new *note Mock.assert_not_called(): 784. method to check if the mock object was called. (Contributed by Kushal Das in bpo-21262(2).) The *note MagicMock: 785. class now supports *note __truediv__(): 786, *note __divmod__(): 787. and *note __matmul__(): 648. operators. (Contributed by Johannes Baiter in bpo-20968(3), and Håkan Lövdahl in bpo-23581(4) and bpo-23568(5).) It is no longer necessary to explicitly pass ‘create=True’ to the *note patch(): 788. function when patching builtin names. (Contributed by Kushal Das in bpo-17660(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue21238 (2) https://bugs.python.org/issue21262 (3) https://bugs.python.org/issue20968 (4) https://bugs.python.org/issue23581 (5) https://bugs.python.org/issue23568 (6) https://bugs.python.org/issue17660  File: python.info, Node: urllib, Next: wsgiref, Prev: unittest mock<3>, Up: Improved Modules<4> 1.4.5.74 urllib ............... A new *note request.HTTPPasswordMgrWithPriorAuth: 78a. class allows HTTP Basic Authentication credentials to be managed so as to eliminate unnecessary ‘401’ response handling, or to unconditionally send credentials on the first request in order to communicate with servers that return a ‘404’ response instead of a ‘401’ if the ‘Authorization’ header is not sent. (Contributed by Matej Cepl in bpo-19494(1) and Akshit Khurana in bpo-7159(2).) A new `quote_via' argument for the *note parse.urlencode(): 78b. function provides a way to control the encoding of query parts if needed. (Contributed by Samwyse and Arnon Yaari in bpo-13866(3).) The *note request.urlopen(): 78c. function accepts an *note ssl.SSLContext: 3e4. object as a `context' argument, which will be used for the HTTPS connection. (Contributed by Alex Gaynor in bpo-22366(4).) The *note parse.urljoin(): 78d. was updated to use the RFC 3986(5) semantics for the resolution of relative URLs, rather than RFC 1808(6) and RFC 2396(7). (Contributed by Demian Brecht and Senthil Kumaran in bpo-22118(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19494 (2) https://bugs.python.org/issue7159 (3) https://bugs.python.org/issue13866 (4) https://bugs.python.org/issue22366 (5) https://tools.ietf.org/html/rfc3986.html (6) https://tools.ietf.org/html/rfc1808.html (7) https://tools.ietf.org/html/rfc2396.html (8) https://bugs.python.org/issue22118  File: python.info, Node: wsgiref, Next: xmlrpc<2>, Prev: urllib, Up: Improved Modules<4> 1.4.5.75 wsgiref ................ The `headers' argument of the *note headers.Headers: 78f. class constructor is now optional. (Contributed by Pablo Torres Navarrete and SilentGhost in bpo-5800(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5800  File: python.info, Node: xmlrpc<2>, Next: xml sax, Prev: wsgiref, Up: Improved Modules<4> 1.4.5.76 xmlrpc ............... The *note client.ServerProxy: 255. class now supports the *note context manager: 568. protocol. (Contributed by Claudiu Popa in bpo-20627(1).) The *note client.ServerProxy: 255. constructor now accepts an optional *note ssl.SSLContext: 3e4. instance. (Contributed by Alex Gaynor in bpo-22960(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue20627 (2) https://bugs.python.org/issue22960  File: python.info, Node: xml sax, Next: zipfile<3>, Prev: xmlrpc<2>, Up: Improved Modules<4> 1.4.5.77 xml.sax ................ SAX parsers now support a character stream of the *note xmlreader.InputSource: 792. object. (Contributed by Serhiy Storchaka in bpo-2175(1).) *note parseString(): 793. now accepts a *note str: 330. instance. (Contributed by Serhiy Storchaka in bpo-10590(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2175 (2) https://bugs.python.org/issue10590  File: python.info, Node: zipfile<3>, Prev: xml sax, Up: Improved Modules<4> 1.4.5.78 zipfile ................ ZIP output can now be written to unseekable streams. (Contributed by Serhiy Storchaka in bpo-23252(1).) The `mode' argument of *note ZipFile.open(): 5bc. method now accepts ‘"x"’ to request exclusive creation. (Contributed by Serhiy Storchaka in bpo-21717(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23252 (2) https://bugs.python.org/issue21717  File: python.info, Node: Other module-level changes, Next: Optimizations<4>, Prev: Improved Modules<4>, Up: What’s New In Python 3 5 1.4.6 Other module-level changes -------------------------------- Many functions in the *note mmap: b3, *note ossaudiodev: c6, *note socket: ef, *note ssl: f3, and *note codecs: 1c. modules now accept writable *note bytes-like objects: 5e8. (Contributed by Serhiy Storchaka in bpo-23001(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23001  File: python.info, Node: Optimizations<4>, Next: Build and C API Changes<3>, Prev: Other module-level changes, Up: What’s New In Python 3 5 1.4.7 Optimizations ------------------- The *note os.walk(): 654. function has been sped up by 3 to 5 times on POSIX systems, and by 7 to 20 times on Windows. This was done using the new *note os.scandir(): 25f. function, which exposes file information from the underlying ‘readdir’ or ‘FindFirstFile’/‘FindNextFile’ system calls. (Contributed by Ben Hoyt with help from Victor Stinner in bpo-23605(1).) Construction of ‘bytes(int)’ (filled by zero bytes) is faster and uses less memory for large objects. ‘calloc()’ is used instead of ‘malloc()’ to allocate memory for these objects. (Contributed by Victor Stinner in bpo-21233(2).) Some operations on *note ipaddress: a2. *note IPv4Network: 3a0. and *note IPv6Network: 39f. have been massively sped up, such as *note subnets(): 797, *note supernet(): 798, *note summarize_address_range(): 799, *note collapse_addresses(): 79a. The speed up can range from 3 to 15 times. (Contributed by Antoine Pitrou, Michel Albert, and Markus in bpo-21486(3), bpo-21487(4), bpo-20826(5), bpo-23266(6).) Pickling of *note ipaddress: a2. objects was optimized to produce significantly smaller output. (Contributed by Serhiy Storchaka in bpo-23133(7).) Many operations on *note io.BytesIO: 79b. are now 50% to 100% faster. (Contributed by Serhiy Storchaka in bpo-15381(8) and David Wilson in bpo-22003(9).) The *note marshal.dumps(): 79c. function is now faster: 65–85% with versions 3 and 4, 20–25% with versions 0 to 2 on typical data, and up to 5 times in best cases. (Contributed by Serhiy Storchaka in bpo-20416(10) and bpo-23344(11).) The UTF-32 encoder is now 3 to 7 times faster. (Contributed by Serhiy Storchaka in bpo-15027(12).) Regular expressions are now parsed up to 10% faster. (Contributed by Serhiy Storchaka in bpo-19380(13).) The *note json.dumps(): 605. function was optimized to run with ‘ensure_ascii=False’ as fast as with ‘ensure_ascii=True’. (Contributed by Naoki Inada in bpo-23206(14).) The *note PyObject_IsInstance(): 79d. and *note PyObject_IsSubclass(): 79e. functions have been sped up in the common case that the second argument has *note type: 608. as its metaclass. (Contributed Georg Brandl by in bpo-22540(15).) Method caching was slightly improved, yielding up to 5% performance improvement in some benchmarks. (Contributed by Antoine Pitrou in bpo-22847(16).) Objects from the *note random: dc. module now use 50% less memory on 64-bit builds. (Contributed by Serhiy Storchaka in bpo-23488(17).) The *note property(): 1d7. getter calls are up to 25% faster. (Contributed by Joe Jevnik in bpo-23910(18).) Instantiation of *note fractions.Fraction: 185. is now up to 30% faster. (Contributed by Stefan Behnel in bpo-22464(19).) String methods *note find(): 79f, *note rfind(): 7a0, *note split(): 7a1, *note partition(): 7a2. and the *note in: 7a3. string operator are now significantly faster for searching 1-character substrings. (Contributed by Serhiy Storchaka in bpo-23573(20).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23605 (2) https://bugs.python.org/issue21233 (3) https://bugs.python.org/issue21486 (4) https://bugs.python.org/issue21487 (5) https://bugs.python.org/issue20826 (6) https://bugs.python.org/issue23266 (7) https://bugs.python.org/issue23133 (8) https://bugs.python.org/issue15381 (9) https://bugs.python.org/issue22003 (10) https://bugs.python.org/issue20416 (11) https://bugs.python.org/issue23344 (12) https://bugs.python.org/issue15027 (13) https://bugs.python.org/issue19380 (14) https://bugs.python.org/issue23206 (15) https://bugs.python.org/issue22540 (16) https://bugs.python.org/issue22847 (17) https://bugs.python.org/issue23488 (18) https://bugs.python.org/issue23910 (19) https://bugs.python.org/issue22464 (20) https://bugs.python.org/issue23573  File: python.info, Node: Build and C API Changes<3>, Next: Deprecated<3>, Prev: Optimizations<4>, Up: What’s New In Python 3 5 1.4.8 Build and C API Changes ----------------------------- New ‘calloc’ functions were added: * *note PyMem_RawCalloc(): 7a5, * *note PyMem_Calloc(): 7a6, * *note PyObject_Calloc(): 7a7. (Contributed by Victor Stinner in bpo-21233(1).) New encoding/decoding helper functions: * *note Py_DecodeLocale(): 43c. (replaced ‘_Py_char2wchar()’), * *note Py_EncodeLocale(): 43d. (replaced ‘_Py_wchar2char()’). (Contributed by Victor Stinner in bpo-18395(2).) A new *note PyCodec_NameReplaceErrors(): 7a8. function to replace the unicode encode error with ‘\N{...}’ escapes. (Contributed by Serhiy Storchaka in bpo-19676(3).) A new *note PyErr_FormatV(): 7a9. function similar to *note PyErr_Format(): 7aa, but accepts a ‘va_list’ argument. (Contributed by Antoine Pitrou in bpo-18711(4).) A new ‘PyExc_RecursionError’ exception. (Contributed by Georg Brandl in bpo-19235(5).) New *note PyModule_FromDefAndSpec(): 7ab, *note PyModule_FromDefAndSpec2(): 7ac, and *note PyModule_ExecDef(): 7ad. functions introduced by PEP 489(6) – multi-phase extension module initialization. (Contributed by Petr Viktorin in bpo-24268(7).) New *note PyNumber_MatrixMultiply(): 7ae. and *note PyNumber_InPlaceMatrixMultiply(): 7af. functions to perform matrix multiplication. (Contributed by Benjamin Peterson in bpo-21176(8). See also PEP 465(9) for details.) The *note PyTypeObject.tp_finalize: 2d7. slot is now part of the stable ABI. Windows builds now require Microsoft Visual C++ 14.0, which is available as part of Visual Studio 2015(10). Extension modules now include a platform information tag in their filename on some platforms (the tag is optional, and CPython will import extensions without it, although if the tag is present and mismatched, the extension won’t be loaded): * On Linux, extension module filenames end with ‘.cpython-m--.pyd’: * ‘’ is the major number of the Python version; for Python 3.5 this is ‘3’. * ‘’ is the minor number of the Python version; for Python 3.5 this is ‘5’. * ‘’ is the hardware architecture the extension module was built to run on. It’s most commonly either ‘i386’ for 32-bit Intel platforms or ‘x86_64’ for 64-bit Intel (and AMD) platforms. * ‘’ is always ‘linux-gnu’, except for extensions built to talk to the 32-bit ABI on 64-bit platforms, in which case it is ‘linux-gnu32’ (and ‘’ will be ‘x86_64’). * On Windows, extension module filenames end with ‘.cp-.pyd’: * ‘’ is the major number of the Python version; for Python 3.5 this is ‘3’. * ‘’ is the minor number of the Python version; for Python 3.5 this is ‘5’. * ‘’ is the platform the extension module was built for, either ‘win32’ for Win32, ‘win_amd64’ for Win64, ‘win_ia64’ for Windows Itanium 64, and ‘win_arm’ for Windows on ARM. * If built in debug mode, ‘’ will be ‘_d’, otherwise it will be blank. * On OS X platforms, extension module filenames now end with ‘-darwin.so’. * On all other platforms, extension module filenames are the same as they were with Python 3.4. ---------- Footnotes ---------- (1) https://bugs.python.org/issue21233 (2) https://bugs.python.org/issue18395 (3) https://bugs.python.org/issue19676 (4) https://bugs.python.org/issue18711 (5) https://bugs.python.org/issue19235 (6) https://www.python.org/dev/peps/pep-0489 (7) https://bugs.python.org/issue24268 (8) https://bugs.python.org/issue21176 (9) https://www.python.org/dev/peps/pep-0465 (10) https://www.visualstudio.com/  File: python.info, Node: Deprecated<3>, Next: Removed<2>, Prev: Build and C API Changes<3>, Up: What’s New In Python 3 5 1.4.9 Deprecated ---------------- * Menu: * New Keywords: New Keywords<2>. * Deprecated Python Behavior: Deprecated Python Behavior<2>. * Unsupported Operating Systems:: * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<3>.  File: python.info, Node: New Keywords<2>, Next: Deprecated Python Behavior<2>, Up: Deprecated<3> 1.4.9.1 New Keywords .................... ‘async’ and ‘await’ are not recommended to be used as variable, class, function or module names. Introduced by PEP 492(1) in Python 3.5, they will become proper keywords in Python 3.7. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0492  File: python.info, Node: Deprecated Python Behavior<2>, Next: Unsupported Operating Systems, Prev: New Keywords<2>, Up: Deprecated<3> 1.4.9.2 Deprecated Python Behavior .................................. Raising the *note StopIteration: 486. exception inside a generator will now generate a silent *note PendingDeprecationWarning: 279, which will become a non-silent deprecation warning in Python 3.6 and will trigger a *note RuntimeError: 2ba. in Python 3.7. See *note PEP 479; Change StopIteration handling inside generators: 5d7. for details.  File: python.info, Node: Unsupported Operating Systems, Next: Deprecated Python modules functions and methods<3>, Prev: Deprecated Python Behavior<2>, Up: Deprecated<3> 1.4.9.3 Unsupported Operating Systems ..................................... Windows XP is no longer supported by Microsoft, thus, per PEP 11(1), CPython 3.5 is no longer officially supported on this OS. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0011  File: python.info, Node: Deprecated Python modules functions and methods<3>, Prev: Unsupported Operating Systems, Up: Deprecated<3> 1.4.9.4 Deprecated Python modules, functions and methods ........................................................ The *note formatter: 82. module has now graduated to full deprecation and is still slated for removal in Python 3.6. The ‘asyncio.async()’ function is deprecated in favor of *note ensure_future(): 517. The *note smtpd: ec. module has in the past always decoded the DATA portion of email messages using the ‘utf-8’ codec. This can now be controlled by the new `decode_data' keyword to *note SMTPServer: 602. The default value is ‘True’, but this default is deprecated. Specify the `decode_data' keyword with an appropriate value to avoid the deprecation warning. Directly assigning values to the *note key: 48d, *note value: 48e. and *note coded_value: 48f. of *note http.cookies.Morsel: 490. objects is deprecated. Use the *note set(): 491. method instead. In addition, the undocumented `LegalChars' parameter of *note set(): 491. is deprecated, and is now ignored. Passing a format string as keyword argument `format_string' to the *note format(): 48c. method of the *note string.Formatter: 7b5. class has been deprecated. (Contributed by Serhiy Storchaka in bpo-23671(1).) The ‘platform.dist()’ and ‘platform.linux_distribution()’ functions are now deprecated. Linux distributions use too many different ways of describing themselves, so the functionality is left to a package. (Contributed by Vajrasky Kok and Berker Peksag in bpo-1322(2).) The previously undocumented ‘from_function’ and ‘from_builtin’ methods of *note inspect.Signature: 6f3. are deprecated. Use the new *note Signature.from_callable(): 6f6. method instead. (Contributed by Yury Selivanov in bpo-24248(3).) The *note inspect.getargspec(): 55c. function is deprecated and scheduled to be removed in Python 3.6. (See bpo-20438(4) for details.) The *note inspect: a0. *note getfullargspec(): 55d, *note getcallargs(): 7b6, and *note formatargspec(): 7b7. functions are deprecated in favor of the *note inspect.signature(): 55b. API. (Contributed by Yury Selivanov in bpo-20438(5).) *note getargvalues(): 7b8. and *note formatargvalues(): 7b9. functions were inadvertently marked as deprecated with the release of Python 3.5.0. Use of *note re.LOCALE: 3c9. flag with str patterns or *note re.ASCII: 3c8. is now deprecated. (Contributed by Serhiy Storchaka in bpo-22407(6).) Use of unrecognized special sequences consisting of ‘'\'’ and an ASCII letter in regular expression patterns and replacement patterns now raises a deprecation warning and will be forbidden in Python 3.6. (Contributed by Serhiy Storchaka in bpo-23622(7).) The undocumented and unofficial `use_load_tests' default argument of the *note unittest.TestLoader.loadTestsFromModule(): 780. method now is deprecated and ignored. (Contributed by Robert Collins and Barry A. Warsaw in bpo-16662(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue23671 (2) https://bugs.python.org/issue1322 (3) https://bugs.python.org/issue24248 (4) https://bugs.python.org/issue20438 (5) https://bugs.python.org/issue20438 (6) https://bugs.python.org/issue22407 (7) https://bugs.python.org/issue23622 (8) https://bugs.python.org/issue16662  File: python.info, Node: Removed<2>, Next: Porting to Python 3 5, Prev: Deprecated<3>, Up: What’s New In Python 3 5 1.4.10 Removed -------------- * Menu: * API and Feature Removals: API and Feature Removals<4>.  File: python.info, Node: API and Feature Removals<4>, Up: Removed<2> 1.4.10.1 API and Feature Removals ................................. The following obsolete and previously deprecated APIs and features have been removed: * The ‘__version__’ attribute has been dropped from the email package. The email code hasn’t been shipped separately from the stdlib for a long time, and the ‘__version__’ string was not updated in the last few releases. * The internal ‘Netrc’ class in the *note ftplib: 84. module was deprecated in 3.4, and has now been removed. (Contributed by Matt Chaput in bpo-6623(1).) * The concept of ‘.pyo’ files has been removed. * The JoinableQueue class in the provisional *note asyncio: a. module was deprecated in 3.4.4 and is now removed. (Contributed by A. Jesse Jiryu Davis in bpo-23464(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6623 (2) https://bugs.python.org/issue23464  File: python.info, Node: Porting to Python 3 5, Next: Notable changes in Python 3 5 4, Prev: Removed<2>, Up: What’s New In Python 3 5 1.4.11 Porting to Python 3.5 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Changes in Python behavior: Changes in Python behavior<2>. * Changes in the Python API: Changes in the Python API<4>. * Changes in the C API: Changes in the C API<4>.  File: python.info, Node: Changes in Python behavior<2>, Next: Changes in the Python API<4>, Up: Porting to Python 3 5 1.4.11.1 Changes in Python behavior ................................... * Due to an oversight, earlier Python versions erroneously accepted the following syntax: f(1 for x in [1], *args) f(1 for x in [1], **kwargs) Python 3.5 now correctly raises a *note SyntaxError: 458, as generator expressions must be put in parentheses if not a sole argument to a function.  File: python.info, Node: Changes in the Python API<4>, Next: Changes in the C API<4>, Prev: Changes in Python behavior<2>, Up: Porting to Python 3 5 1.4.11.2 Changes in the Python API .................................. * PEP 475(1): System calls are now retried when interrupted by a signal instead of raising *note InterruptedError: 659. if the Python signal handler does not raise an exception. * Before Python 3.5, a *note datetime.time: 4f3. object was considered to be false if it represented midnight in UTC. This behavior was considered obscure and error-prone and has been removed in Python 3.5. See bpo-13936(2) for full details. * The ‘ssl.SSLSocket.send()’ method now raises either *note ssl.SSLWantReadError: 756. or *note ssl.SSLWantWriteError: 757. on a non-blocking socket if the operation would block. Previously, it would return ‘0’. (Contributed by Nikolaus Rath in bpo-20951(3).) * The ‘__name__’ attribute of generators is now set from the function name, instead of being set from the code name. Use ‘gen.gi_code.co_name’ to retrieve the code name. Generators also have a new ‘__qualname__’ attribute, the qualified name, which is now used for the representation of a generator (‘repr(gen)’). (Contributed by Victor Stinner in bpo-21205(4).) * The deprecated “strict” mode and argument of *note HTMLParser: 7bf, ‘HTMLParser.error()’, and the ‘HTMLParserError’ exception have been removed. (Contributed by Ezio Melotti in bpo-15114(5).) The `convert_charrefs' argument of *note HTMLParser: 7bf. is now ‘True’ by default. (Contributed by Berker Peksag in bpo-21047(6).) * Although it is not formally part of the API, it is worth noting for porting purposes (ie: fixing tests) that error messages that were previously of the form “‘sometype’ does not support the buffer protocol” are now of the form “a *note bytes-like object: 5e8. is required, not ‘sometype’”. (Contributed by Ezio Melotti in bpo-16518(7).) * If the current directory is set to a directory that no longer exists then *note FileNotFoundError: 7c0. will no longer be raised and instead *note find_spec(): 7c1. will return ‘None’ `without' caching ‘None’ in *note sys.path_importer_cache: 49d, which is different than the typical case (bpo-22834(8)). * HTTP status code and messages from *note http.client: 94. and *note http.server: 97. were refactored into a common *note HTTPStatus: 6e2. enum. The values in *note http.client: 94. and *note http.server: 97. remain available for backwards compatibility. (Contributed by Demian Brecht in bpo-21793(9).) * When an import loader defines ‘importlib.machinery.Loader.exec_module()’ it is now expected to also define ‘create_module()’ (raises a *note DeprecationWarning: 278. now, will be an error in Python 3.6). If the loader inherits from *note importlib.abc.Loader: 7c2. then there is nothing to do, else simply define ‘create_module()’ to return ‘None’. (Contributed by Brett Cannon in bpo-23014(10).) * The *note re.split(): 3ca. function always ignored empty pattern matches, so the ‘"x*"’ pattern worked the same as ‘"x+"’, and the ‘"\b"’ pattern never worked. Now *note re.split(): 3ca. raises a warning if the pattern could match an empty string. For compatibility, use patterns that never match an empty string (e.g. ‘"x+"’ instead of ‘"x*"’). Patterns that could only match an empty string (such as ‘"\b"’) now raise an error. (Contributed by Serhiy Storchaka in bpo-22818(11).) * The *note http.cookies.Morsel: 490. dict-like interface has been made self consistent: morsel comparison now takes the *note key: 48d. and *note value: 48e. into account, *note copy(): 7c3. now results in a *note Morsel: 490. instance rather than a *note dict: 1b8, and *note update(): 7c4. will now raise an exception if any of the keys in the update dictionary are invalid. In addition, the undocumented `LegalChars' parameter of *note set(): 491. is deprecated and is now ignored. (Contributed by Demian Brecht in bpo-2211(12).) * PEP 488(13) has removed ‘.pyo’ files from Python and introduced the optional ‘opt-’ tag in ‘.pyc’ file names. The *note importlib.util.cache_from_source(): 557. has gained an `optimization' parameter to help control the ‘opt-’ tag. Because of this, the `debug_override' parameter of the function is now deprecated. ‘.pyo’ files are also no longer supported as a file argument to the Python interpreter and thus serve no purpose when distributed on their own (i.e. sourceless code distribution). Due to the fact that the magic number for bytecode has changed in Python 3.5, all old ‘.pyo’ files from previous versions of Python are invalid regardless of this PEP. * The *note socket: ef. module now exports the *note CAN_RAW_FD_FRAMES: 7c5. constant on linux 3.6 and greater. * The *note ssl.cert_time_to_seconds(): 758. function now interprets the input time as UTC and not as local time, per RFC 5280(14). Additionally, the return value is always an *note int: 184. (Contributed by Akira Li in bpo-19940(15).) * The ‘pygettext.py’ Tool now uses the standard +NNNN format for timezones in the POT-Creation-Date header. * The *note smtplib: ed. module now uses *note sys.stderr: 30f. instead of the previous module-level ‘stderr’ variable for debug output. If your (test) program depends on patching the module-level variable to capture the debug output, you will need to update it to capture sys.stderr instead. * The *note str.startswith(): 7c6. and *note str.endswith(): 7c7. methods no longer return ‘True’ when finding the empty string and the indexes are completely out of range. (Contributed by Serhiy Storchaka in bpo-24284(16).) * The *note inspect.getdoc(): 1d6. function now returns documentation strings inherited from base classes. Documentation strings no longer need to be duplicated if the inherited documentation is appropriate. To suppress an inherited string, an empty string must be specified (or the documentation may be filled in). This change affects the output of the *note pydoc: d9. module and the *note help(): 572. function. (Contributed by Serhiy Storchaka in bpo-15582(17).) * Nested *note functools.partial(): 7c8. calls are now flattened. If you were relying on the previous behavior, you can now either add an attribute to a *note functools.partial(): 7c8. object or you can create a subclass of *note functools.partial(): 7c8. (Contributed by Alexander Belopolsky in bpo-7830(18).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0475 (2) https://bugs.python.org/issue13936 (3) https://bugs.python.org/issue20951 (4) https://bugs.python.org/issue21205 (5) https://bugs.python.org/issue15114 (6) https://bugs.python.org/issue21047 (7) https://bugs.python.org/issue16518 (8) https://bugs.python.org/issue22834 (9) https://bugs.python.org/issue21793 (10) https://bugs.python.org/issue23014 (11) https://bugs.python.org/issue22818 (12) https://bugs.python.org/issue2211 (13) https://www.python.org/dev/peps/pep-0488 (14) https://tools.ietf.org/html/rfc5280.html (15) https://bugs.python.org/issue19940 (16) https://bugs.python.org/issue24284 (17) https://bugs.python.org/issue15582 (18) https://bugs.python.org/issue7830  File: python.info, Node: Changes in the C API<4>, Prev: Changes in the Python API<4>, Up: Porting to Python 3 5 1.4.11.3 Changes in the C API ............................. * The undocumented ‘format’ member of the (non-public) ‘PyMemoryViewObject’ structure has been removed. All extensions relying on the relevant parts in ‘memoryobject.h’ must be rebuilt. * The ‘PyMemAllocator’ structure was renamed to *note PyMemAllocatorEx: 7ca. and a new ‘calloc’ field was added. * Removed non-documented macro ‘PyObject_REPR’ which leaked references. Use format character ‘%R’ in *note PyUnicode_FromFormat(): 7cb.-like functions to format the *note repr(): 7cc. of the object. (Contributed by Serhiy Storchaka in bpo-22453(1).) * Because the lack of the ‘__module__’ attribute breaks pickling and introspection, a deprecation warning is now raised for builtin types without the ‘__module__’ attribute. This would be an AttributeError in the future. (Contributed by Serhiy Storchaka in bpo-20204(2).) * As part of the PEP 492(3) implementation, the ‘tp_reserved’ slot of *note PyTypeObject: 2d6. was replaced with a ‘tp_as_async’ slot. Refer to *note Coroutine Objects: 7cd. for new types, structures and functions. ---------- Footnotes ---------- (1) https://bugs.python.org/issue22453 (2) https://bugs.python.org/issue20204 (3) https://www.python.org/dev/peps/pep-0492  File: python.info, Node: Notable changes in Python 3 5 4, Prev: Porting to Python 3 5, Up: What’s New In Python 3 5 1.4.12 Notable changes in Python 3.5.4 -------------------------------------- * Menu: * New make regen-all build target: New make regen-all build target<2>. * Removal of make touch build target: Removal of make touch build target<2>.  File: python.info, Node: New make regen-all build target<2>, Next: Removal of make touch build target<2>, Up: Notable changes in Python 3 5 4 1.4.12.1 New ‘make regen-all’ build target .......................................... To simplify cross-compilation, and to ensure that CPython can reliably be compiled without requiring an existing version of Python to already be available, the autotools-based build system no longer attempts to implicitly recompile generated files based on file modification times. Instead, a new ‘make regen-all’ command has been added to force regeneration of these files when desired (e.g. after an initial version of Python has already been built based on the pregenerated versions). More selective regeneration targets are also defined - see Makefile.pre.in(1) for details. (Contributed by Victor Stinner in bpo-23404(2).) New in version 3.5.4. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Makefile.pre.in (2) https://bugs.python.org/issue23404  File: python.info, Node: Removal of make touch build target<2>, Prev: New make regen-all build target<2>, Up: Notable changes in Python 3 5 4 1.4.12.2 Removal of ‘make touch’ build target ............................................. The ‘make touch’ build target previously used to request implicit regeneration of generated files by updating their modification times has been removed. It has been replaced by the new ‘make regen-all’ target. (Contributed by Victor Stinner in bpo-23404(1).) Changed in version 3.5.4. ---------- Footnotes ---------- (1) https://bugs.python.org/issue23404  File: python.info, Node: What’s New In Python 3 4, Next: What’s New In Python 3 3, Prev: What’s New In Python 3 5, Up: What’s New in Python 1.5 What’s New In Python 3.4 ============================ Author: R. David Murray <> (Editor) This article explains the new features in Python 3.4, compared to 3.3. Python 3.4 was released on March 16, 2014. For full details, see the changelog(1). See also ........ PEP 429(2) – Python 3.4 Release Schedule * Menu: * Summary – Release Highlights: Summary – Release Highlights<2>. * New Features: New Features<5>. * New Modules: New Modules<5>. * Improved Modules: Improved Modules<5>. * CPython Implementation Changes:: * Deprecated: Deprecated<4>. * Removed: Removed<3>. * Porting to Python 3.4: Porting to Python 3 4. * Changed in 3.4.3: Changed in 3 4 3. ---------- Footnotes ---------- (1) https://docs.python.org/3.4/whatsnew/changelog.html (2) https://www.python.org/dev/peps/pep-0429  File: python.info, Node: Summary – Release Highlights<2>, Next: New Features<5>, Up: What’s New In Python 3 4 1.5.1 Summary – Release Highlights ---------------------------------- New syntax features: * No new syntax features were added in Python 3.4. Other new features: * *note pip should always be available: 7d4. ( PEP 453(1)). * *note Newly created file descriptors are non-inheritable: 7d5. ( PEP 446(2)). * command line option for *note isolated mode: 7d6. (bpo-16499(3)). * *note improvements in the handling of codecs: 7d7. that are not text encodings (multiple issues). * *note A ModuleSpec Type: 7d8. for the Import System ( PEP 451(4)). (Affects importer authors.) * The *note marshal: b0. format has been made *note more compact and efficient: 7d9. (bpo-16475(5)). New library modules: * *note asyncio: a.: *note New provisional API for asynchronous IO: 7da. ( PEP 3156(6)). * *note ensurepip: 7a.: *note Bootstrapping the pip installer: 7db. ( PEP 453(7)). * *note enum: 7b.: *note Support for enumeration types: 7dc. ( PEP 435(8)). * *note pathlib: c8.: *note Object-oriented filesystem paths: 7dd. ( PEP 428(9)). * *note selectors: e6.: *note High-level and efficient I/O multiplexing: 7de, built upon the *note select: e5. module primitives (part of PEP 3156(10)). * *note statistics: f5.: A basic *note numerically stable statistics library: 7df. ( PEP 450(11)). * *note tracemalloc: 114.: *note Trace Python memory allocations: 7e0. ( PEP 454(12)). Significantly improved library modules: * *note Single-dispatch generic functions: 7e1. in *note functools: 85. ( PEP 443(13)). * New *note pickle: ca. *note protocol 4: 7e2. ( PEP 3154(14)). * *note multiprocessing: b7. now has *note an option to avoid using os.fork on Unix: 7e3. (bpo-8713(15)). * *note email: 69. has a new submodule, *note contentmanager: 6b, and a new *note Message: 541. subclass (‘EmailMessage’) that *note simplify MIME handling: 7e4. (bpo-18891(16)). * The *note inspect: a0. and *note pydoc: d9. modules are now capable of correct introspection of a much wider variety of callable objects, which improves the output of the Python *note help(): 572. system. * The *note ipaddress: a2. module API has been declared stable Security improvements: * *note Secure and interchangeable hash algorithm: 7e5. ( PEP 456(17)). * *note Make newly created file descriptors non-inheritable: 7d5. ( PEP 446(18)) to avoid leaking file descriptors to child processes. * New command line option for *note isolated mode: 7d6, (bpo-16499(19)). * *note multiprocessing: b7. now has *note an option to avoid using os.fork on Unix: 7e3. `spawn' and `forkserver' are more secure because they avoid sharing data with child processes. * *note multiprocessing: b7. child processes on Windows no longer inherit all of the parent’s inheritable handles, only the necessary ones. * A new *note hashlib.pbkdf2_hmac(): 7e6. function provides the PKCS#5 password-based key derivation function 2(20). * *note TLSv1.1 and TLSv1.2 support: 7e7. for *note ssl: f3. * *note Retrieving certificates from the Windows system cert store support: 7e8. for *note ssl: f3. * *note Server-side SNI (Server Name Indication) support: 7e9. for *note ssl: f3. * The *note ssl.SSLContext: 3e4. class has a *note lot of improvements: 7ea. * All modules in the standard library that support SSL now support server certificate verification, including hostname matching (*note ssl.match_hostname(): 3dc.) and CRLs (Certificate Revocation lists, see *note ssl.SSLContext.load_verify_locations(): 7eb.). CPython implementation improvements: * *note Safe object finalization: 7ec. ( PEP 442(21)). * Leveraging PEP 442(22), in most cases *note module globals are no longer set to None during finalization: 7ec. (bpo-18214(23)). * *note Configurable memory allocators: 7ed. ( PEP 445(24)). * *note Argument Clinic: 7ee. ( PEP 436(25)). Please read on for a comprehensive list of user-facing changes, including many other smaller improvements, CPython optimizations, deprecations, and potential porting issues. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0453 (2) https://www.python.org/dev/peps/pep-0446 (3) https://bugs.python.org/issue16499 (4) https://www.python.org/dev/peps/pep-0451 (5) https://bugs.python.org/issue16475 (6) https://www.python.org/dev/peps/pep-3156 (7) https://www.python.org/dev/peps/pep-0453 (8) https://www.python.org/dev/peps/pep-0435 (9) https://www.python.org/dev/peps/pep-0428 (10) https://www.python.org/dev/peps/pep-3156 (11) https://www.python.org/dev/peps/pep-0450 (12) https://www.python.org/dev/peps/pep-0454 (13) https://www.python.org/dev/peps/pep-0443 (14) https://www.python.org/dev/peps/pep-3154 (15) https://bugs.python.org/issue8713 (16) https://bugs.python.org/issue18891 (17) https://www.python.org/dev/peps/pep-0456 (18) https://www.python.org/dev/peps/pep-0446 (19) https://bugs.python.org/issue16499 (20) https://en.wikipedia.org/wiki/PBKDF2 (21) https://www.python.org/dev/peps/pep-0442 (22) https://www.python.org/dev/peps/pep-0442 (23) https://bugs.python.org/issue18214 (24) https://www.python.org/dev/peps/pep-0445 (25) https://www.python.org/dev/peps/pep-0436  File: python.info, Node: New Features<5>, Next: New Modules<5>, Prev: Summary – Release Highlights<2>, Up: What’s New In Python 3 4 1.5.2 New Features ------------------ * Menu: * PEP 453; Explicit Bootstrapping of PIP in Python Installations: PEP 453 Explicit Bootstrapping of PIP in Python Installations. * PEP 446; Newly Created File Descriptors Are Non-Inheritable: PEP 446 Newly Created File Descriptors Are Non-Inheritable. * Improvements to Codec Handling:: * PEP 451; A ModuleSpec Type for the Import System: PEP 451 A ModuleSpec Type for the Import System. * Other Language Changes: Other Language Changes<5>.  File: python.info, Node: PEP 453 Explicit Bootstrapping of PIP in Python Installations, Next: PEP 446 Newly Created File Descriptors Are Non-Inheritable, Up: New Features<5> 1.5.2.1 PEP 453: Explicit Bootstrapping of PIP in Python Installations ...................................................................... * Menu: * Bootstrapping pip By Default:: * Documentation Changes::  File: python.info, Node: Bootstrapping pip By Default, Next: Documentation Changes, Up: PEP 453 Explicit Bootstrapping of PIP in Python Installations 1.5.2.2 Bootstrapping pip By Default .................................... The new *note ensurepip: 7a. module (defined in PEP 453(1)) provides a standard cross-platform mechanism to bootstrap the pip installer into Python installations and virtual environments. The version of ‘pip’ included with Python 3.4.0 is ‘pip’ 1.5.4, and future 3.4.x maintenance releases will update the bundled version to the latest version of ‘pip’ that is available at the time of creating the release candidate. By default, the commands ‘pipX’ and ‘pipX.Y’ will be installed on all platforms (where X.Y stands for the version of the Python installation), along with the ‘pip’ Python package and its dependencies. On Windows and in virtual environments on all platforms, the unversioned ‘pip’ command will also be installed. On other platforms, the system wide unversioned ‘pip’ command typically refers to the separately installed Python 2 version. The ‘pyvenv’ command line utility and the *note venv: 125. module make use of the *note ensurepip: 7a. module to make ‘pip’ readily available in virtual environments. When using the command line utility, ‘pip’ is installed by default, while when using the *note venv: 125. module *note API: 7f2. installation of ‘pip’ must be requested explicitly. For CPython *note source builds on POSIX systems: 7f3, the ‘make install’ and ‘make altinstall’ commands bootstrap ‘pip’ by default. This behaviour can be controlled through configure options, and overridden through Makefile options. On Windows and Mac OS X, the CPython installers now default to installing ‘pip’ along with CPython itself (users may opt out of installing it during the installation process). Window users will need to opt in to the automatic ‘PATH’ modifications to have ‘pip’ available from the command line by default, otherwise it can still be accessed through the Python launcher for Windows as ‘py -m pip’. As discussed in the PEP(2), platform packagers may choose not to install these commands by default, as long as, when invoked, they provide clear and simple directions on how to install them on that platform (usually using the system package manager). Note: To avoid conflicts between parallel Python 2 and Python 3 installations, only the versioned ‘pip3’ and ‘pip3.4’ commands are bootstrapped by default when ‘ensurepip’ is invoked directly - the ‘--default-pip’ option is needed to also request the unversioned ‘pip’ command. ‘pyvenv’ and the Windows installer ensure that the unqualified ‘pip’ command is made available in those environments, and ‘pip’ can always be invoked via the ‘-m’ switch rather than directly to avoid ambiguity on systems with multiple Python installations. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0453 (2) https://www.python.org/dev/peps/pep-0453/#recommendations-for-downstream-distributors  File: python.info, Node: Documentation Changes, Prev: Bootstrapping pip By Default, Up: PEP 453 Explicit Bootstrapping of PIP in Python Installations 1.5.2.3 Documentation Changes ............................. As part of this change, the *note Installing Python Modules: 7f5. and *note Distributing Python Modules: 7f6. sections of the documentation have been completely redesigned as short getting started and FAQ documents. Most packaging documentation has now been moved out to the Python Packaging Authority maintained Python Packaging User Guide(1) and the documentation of the individual projects. However, as this migration is currently still incomplete, the legacy versions of those guides remaining available as *note Installing Python Modules (Legacy version): 7f7. and *note Distributing Python Modules (Legacy version): 7f8. See also ........ PEP 453(2) – Explicit bootstrapping of pip in Python installations PEP written by Donald Stufft and Nick Coghlan, implemented by Donald Stufft, Nick Coghlan, Martin von Löwis and Ned Deily. ---------- Footnotes ---------- (1) https://packaging.python.org (2) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: PEP 446 Newly Created File Descriptors Are Non-Inheritable, Next: Improvements to Codec Handling, Prev: PEP 453 Explicit Bootstrapping of PIP in Python Installations, Up: New Features<5> 1.5.2.4 PEP 446: Newly Created File Descriptors Are Non-Inheritable ................................................................... PEP 446(1) makes newly created file descriptors *note non-inheritable: 7fa. In general, this is the behavior an application will want: when launching a new process, having currently open files also open in the new process can lead to all sorts of hard to find bugs, and potentially to security issues. However, there are occasions when inheritance is desired. To support these cases, the following new functions and methods are available: * *note os.get_inheritable(): 7fb, *note os.set_inheritable(): 7fc. * *note os.get_handle_inheritable(): 7fd, *note os.set_handle_inheritable(): 7fe. * *note socket.socket.get_inheritable(): 7ff, *note socket.socket.set_inheritable(): 800. See also ........ PEP 446(2) – Make newly created file descriptors non-inheritable PEP written and implemented by Victor Stinner. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0446 (2) https://www.python.org/dev/peps/pep-0446  File: python.info, Node: Improvements to Codec Handling, Next: PEP 451 A ModuleSpec Type for the Import System, Prev: PEP 446 Newly Created File Descriptors Are Non-Inheritable, Up: New Features<5> 1.5.2.5 Improvements to Codec Handling ...................................... Since it was first introduced, the *note codecs: 1c. module has always been intended to operate as a type-neutral dynamic encoding and decoding system. However, its close coupling with the Python text model, especially the type restricted convenience methods on the builtin *note str: 330, *note bytes: 331. and *note bytearray: 332. types, has historically obscured that fact. As a key step in clarifying the situation, the *note codecs.encode(): 802. and *note codecs.decode(): 803. convenience functions are now properly documented in Python 2.7, 3.3 and 3.4. These functions have existed in the *note codecs: 1c. module (and have been covered by the regression test suite) since Python 2.4, but were previously only discoverable through runtime introspection. Unlike the convenience methods on *note str: 330, *note bytes: 331. and *note bytearray: 332, the *note codecs: 1c. convenience functions support arbitrary codecs in both Python 2 and Python 3, rather than being limited to Unicode text encodings (in Python 3) or ‘basestring’ <-> ‘basestring’ conversions (in Python 2). In Python 3.4, the interpreter is able to identify the known non-text encodings provided in the standard library and direct users towards these general purpose convenience functions when appropriate: >>> b"abcdef".decode("hex") Traceback (most recent call last): File "", line 1, in LookupError: 'hex' is not a text encoding; use codecs.decode() to handle arbitrary codecs >>> "hello".encode("rot13") Traceback (most recent call last): File "", line 1, in LookupError: 'rot13' is not a text encoding; use codecs.encode() to handle arbitrary codecs >>> open("foo.txt", encoding="hex") Traceback (most recent call last): File "", line 1, in LookupError: 'hex' is not a text encoding; use codecs.open() to handle arbitrary codecs In a related change, whenever it is feasible without breaking backwards compatibility, exceptions raised during encoding and decoding operations are wrapped in a chained exception of the same type that mentions the name of the codec responsible for producing the error: >>> import codecs >>> codecs.decode(b"abcdefgh", "hex") Traceback (most recent call last): File "/usr/lib/python3.4/encodings/hex_codec.py", line 20, in hex_decode return (binascii.a2b_hex(input), len(input)) binascii.Error: Non-hexadecimal digit found The above exception was the direct cause of the following exception: Traceback (most recent call last): File "", line 1, in binascii.Error: decoding with 'hex' codec failed (Error: Non-hexadecimal digit found) >>> codecs.encode("hello", "bz2") Traceback (most recent call last): File "/usr/lib/python3.4/encodings/bz2_codec.py", line 17, in bz2_encode return (bz2.compress(input), len(input)) File "/usr/lib/python3.4/bz2.py", line 498, in compress return comp.compress(data) + comp.flush() TypeError: 'str' does not support the buffer interface The above exception was the direct cause of the following exception: Traceback (most recent call last): File "", line 1, in TypeError: encoding with 'bz2' codec failed (TypeError: 'str' does not support the buffer interface) Finally, as the examples above show, these improvements have permitted the restoration of the convenience aliases for the non-Unicode codecs that were themselves restored in Python 3.2. This means that encoding binary data to and from its hexadecimal representation (for example) can now be written as: >>> from codecs import encode, decode >>> encode(b"hello", "hex") b'68656c6c6f' >>> decode(b"68656c6c6f", "hex") b'hello' The binary and text transforms provided in the standard library are detailed in *note Binary Transforms: 804. and *note Text Transforms: 805. (Contributed by Nick Coghlan in bpo-7475(1), bpo-17827(2), bpo-17828(3) and bpo-19619(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue7475 (2) https://bugs.python.org/issue17827 (3) https://bugs.python.org/issue17828 (4) https://bugs.python.org/issue19619  File: python.info, Node: PEP 451 A ModuleSpec Type for the Import System, Next: Other Language Changes<5>, Prev: Improvements to Codec Handling, Up: New Features<5> 1.5.2.6 PEP 451: A ModuleSpec Type for the Import System ........................................................ PEP 451(1) provides an encapsulation of the information about a module that the import machinery will use to load it (that is, a module specification). This helps simplify both the import implementation and several import-related APIs. The change is also a stepping stone for several future import-related improvements(2). The public-facing changes from the PEP are entirely backward-compatible. Furthermore, they should be transparent to everyone but importer authors. Key finder and loader methods have been deprecated, but they will continue working. New importers should use the new methods described in the PEP. Existing importers should be updated to implement the new methods. See the *note Deprecated: 807. section for a list of methods that should be replaced and their replacements. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0451 (2) https://mail.python.org/pipermail/python-dev/2013-November/130111.html  File: python.info, Node: Other Language Changes<5>, Prev: PEP 451 A ModuleSpec Type for the Import System, Up: New Features<5> 1.5.2.7 Other Language Changes .............................. Some smaller changes made to the core Python language are: * Unicode database updated to UCD version 6.3. * *note min(): 809. and *note max(): 80a. now accept a `default' keyword-only argument that can be used to specify the value they return if the iterable they are evaluating has no elements. (Contributed by Julian Berman in bpo-18111(1).) * Module objects are now *note weakref: 128.’able. * Module ‘__file__’ attributes (and related values) should now always contain absolute paths by default, with the sole exception of ‘__main__.__file__’ when a script has been executed directly using a relative path. (Contributed by Brett Cannon in bpo-18416(2).) * All the UTF-* codecs (except UTF-7) now reject surrogates during both encoding and decoding unless the ‘surrogatepass’ error handler is used, with the exception of the UTF-16 decoder (which accepts valid surrogate pairs) and the UTF-16 encoder (which produces them while encoding non-BMP characters). (Contributed by Victor Stinner, Kang-Hao (Kenny) Lu and Serhiy Storchaka in bpo-12892(3).) * New German EBCDIC *note codec: 68f. ‘cp273’. (Contributed by Michael Bierenfeld and Andrew Kuchling in bpo-1097797(4).) * New Ukrainian *note codec: 68f. ‘cp1125’. (Contributed by Serhiy Storchaka in bpo-19668(5).) * *note bytes: 331.join() and *note bytearray: 332.join() now accept arbitrary buffer objects as arguments. (Contributed by Antoine Pitrou in bpo-15958(6).) * The *note int: 184. constructor now accepts any object that has an ‘__index__’ method for its `base' argument. (Contributed by Mark Dickinson in bpo-16772(7).) * Frame objects now have a *note clear(): 80b. method that clears all references to local variables from the frame. (Contributed by Antoine Pitrou in bpo-17934(8).) * *note memoryview: 25c. is now registered as a *note Sequence: 1f, and supports the *note reversed(): 18e. builtin. (Contributed by Nick Coghlan and Claudiu Popa in bpo-18690(9) and bpo-19078(10).) * Signatures reported by *note help(): 572. have been modified and improved in several cases as a result of the introduction of Argument Clinic and other changes to the *note inspect: a0. and *note pydoc: d9. modules. * *note __length_hint__(): 80c. is now part of the formal language specification (see PEP 424(11)). (Contributed by Armin Ronacher in bpo-16148(12).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18111 (2) https://bugs.python.org/issue18416 (3) https://bugs.python.org/issue12892 (4) https://bugs.python.org/issue1097797 (5) https://bugs.python.org/issue19668 (6) https://bugs.python.org/issue15958 (7) https://bugs.python.org/issue16772 (8) https://bugs.python.org/issue17934 (9) https://bugs.python.org/issue18690 (10) https://bugs.python.org/issue19078 (11) https://www.python.org/dev/peps/pep-0424 (12) https://bugs.python.org/issue16148  File: python.info, Node: New Modules<5>, Next: Improved Modules<5>, Prev: New Features<5>, Up: What’s New In Python 3 4 1.5.3 New Modules ----------------- * Menu: * asyncio: asyncio<6>. * ensurepip:: * enum: enum<5>. * pathlib: pathlib<5>. * selectors: selectors<2>. * statistics: statistics<3>. * tracemalloc: tracemalloc<3>.  File: python.info, Node: asyncio<6>, Next: ensurepip, Up: New Modules<5> 1.5.3.1 asyncio ............... The new *note asyncio: a. module (defined in PEP 3156(1)) provides a standard pluggable event loop model for Python, providing solid asynchronous IO support in the standard library, and making it easier for other event loop implementations to interoperate with the standard library and each other. For Python 3.4, this module is considered a *note provisional API: 348. See also ........ PEP 3156(2) – Asynchronous IO Support Rebooted: the “asyncio” Module PEP written and implementation led by Guido van Rossum. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3156 (2) https://www.python.org/dev/peps/pep-3156  File: python.info, Node: ensurepip, Next: enum<5>, Prev: asyncio<6>, Up: New Modules<5> 1.5.3.2 ensurepip ................. The new *note ensurepip: 7a. module is the primary infrastructure for the PEP 453(1) implementation. In the normal course of events end users will not need to interact with this module, but it can be used to manually bootstrap ‘pip’ if the automated bootstrapping into an installation or virtual environment was declined. *note ensurepip: 7a. includes a bundled copy of ‘pip’, up-to-date as of the first release candidate of the release of CPython with which it ships (this applies to both maintenance releases and feature releases). ‘ensurepip’ does not access the internet. If the installation has Internet access, after ‘ensurepip’ is run the bundled ‘pip’ can be used to upgrade ‘pip’ to a more recent release than the bundled one. (Note that such an upgraded version of ‘pip’ is considered to be a separately installed package and will not be removed if Python is uninstalled.) The module is named `ensure'pip because if called when ‘pip’ is already installed, it does nothing. It also has an ‘--upgrade’ option that will cause it to install the bundled copy of ‘pip’ if the existing installed version of ‘pip’ is older than the bundled copy. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: enum<5>, Next: pathlib<5>, Prev: ensurepip, Up: New Modules<5> 1.5.3.3 enum ............ The new *note enum: 7b. module (defined in PEP 435(1)) provides a standard implementation of enumeration types, allowing other modules (such as *note socket: ef.) to provide more informative error messages and better debugging support by replacing opaque integer constants with backwards compatible enumeration values. See also ........ PEP 435(2) – Adding an Enum type to the Python standard library PEP written by Barry Warsaw, Eli Bendersky and Ethan Furman, implemented by Ethan Furman. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0435 (2) https://www.python.org/dev/peps/pep-0435  File: python.info, Node: pathlib<5>, Next: selectors<2>, Prev: enum<5>, Up: New Modules<5> 1.5.3.4 pathlib ............... The new *note pathlib: c8. module offers classes representing filesystem paths with semantics appropriate for different operating systems. Path classes are divided between `pure paths', which provide purely computational operations without I/O, and `concrete paths', which inherit from pure paths but also provide I/O operations. For Python 3.4, this module is considered a *note provisional API: 348. See also ........ PEP 428(1) – The pathlib module – object-oriented filesystem paths PEP written and implemented by Antoine Pitrou. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0428  File: python.info, Node: selectors<2>, Next: statistics<3>, Prev: pathlib<5>, Up: New Modules<5> 1.5.3.5 selectors ................. The new *note selectors: e6. module (created as part of implementing PEP 3156(1)) allows high-level and efficient I/O multiplexing, built upon the *note select: e5. module primitives. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3156  File: python.info, Node: statistics<3>, Next: tracemalloc<3>, Prev: selectors<2>, Up: New Modules<5> 1.5.3.6 statistics .................. The new *note statistics: f5. module (defined in PEP 450(1)) offers some core statistics functionality directly in the standard library. This module supports calculation of the mean, median, mode, variance and standard deviation of a data series. See also ........ PEP 450(2) – Adding A Statistics Module To The Standard Library PEP written and implemented by Steven D’Aprano ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0450 (2) https://www.python.org/dev/peps/pep-0450  File: python.info, Node: tracemalloc<3>, Prev: statistics<3>, Up: New Modules<5> 1.5.3.7 tracemalloc ................... The new *note tracemalloc: 114. module (defined in PEP 454(1)) is a debug tool to trace memory blocks allocated by Python. It provides the following information: * Trace where an object was allocated * Statistics on allocated memory blocks per filename and per line number: total size, number and average size of allocated memory blocks * Compute the differences between two snapshots to detect memory leaks See also ........ PEP 454(2) – Add a new tracemalloc module to trace Python memory allocations PEP written and implemented by Victor Stinner ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0454 (2) https://www.python.org/dev/peps/pep-0454  File: python.info, Node: Improved Modules<5>, Next: CPython Implementation Changes, Prev: New Modules<5>, Up: What’s New In Python 3 4 1.5.4 Improved Modules ---------------------- * Menu: * abc:: * aifc: aifc<2>. * argparse: argparse<3>. * audioop:: * base64:: * collections: collections<6>. * colorsys:: * contextlib: contextlib<4>. * dbm: dbm<5>. * dis: dis<2>. * doctest: doctest<2>. * email: email<3>. * filecmp:: * functools: functools<4>. * gc: gc<3>. * glob: glob<2>. * hashlib: hashlib<2>. * hmac: hmac<2>. * html:: * http: http<2>. * idlelib and IDLE: idlelib and IDLE<4>. * importlib: importlib<6>. * inspect: inspect<4>. * ipaddress: ipaddress<3>. * logging: logging<5>. * marshal:: * mmap: mmap<2>. * multiprocessing: multiprocessing<5>. * operator: operator<2>. * os: os<6>. * pdb: pdb<3>. * pickle: pickle<4>. * plistlib: plistlib<2>. * poplib: poplib<2>. * pprint: pprint<2>. * pty:: * pydoc: pydoc<3>. * re: re<5>. * resource:: * select:: * shelve:: * shutil: shutil<3>. * smtpd: smtpd<2>. * smtplib: smtplib<2>. * socket: socket<6>. * sqlite3: sqlite3<4>. * ssl: ssl<7>. * stat:: * struct: struct<2>. * subprocess: subprocess<4>. * sunau: sunau<2>. * sys: sys<6>. * tarfile: tarfile<3>. * textwrap:: * threading: threading<4>. * traceback: traceback<3>. * types: types<3>. * urllib: urllib<2>. * unittest: unittest<4>. * venv: venv<4>. * wave: wave<2>. * weakref: weakref<2>. * xml.etree: xml etree<2>. * zipfile: zipfile<4>.  File: python.info, Node: abc, Next: aifc<2>, Up: Improved Modules<5> 1.5.4.1 abc ........... New function *note abc.get_cache_token(): 817. can be used to know when to invalidate caches that are affected by changes in the object graph. (Contributed by Łukasz Langa in bpo-16832(1).) New class *note ABC: 818. has *note ABCMeta: 819. as its meta class. Using ‘ABC’ as a base class has essentially the same effect as specifying ‘metaclass=abc.ABCMeta’, but is simpler to type and easier to read. (Contributed by Bruno Dupuis in bpo-16049(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16832 (2) https://bugs.python.org/issue16049  File: python.info, Node: aifc<2>, Next: argparse<3>, Prev: abc, Up: Improved Modules<5> 1.5.4.2 aifc ............ The *note getparams(): 81b. method now returns a namedtuple rather than a plain tuple. (Contributed by Claudiu Popa in bpo-17818(1).) *note aifc.open(): 45b. now supports the context management protocol: when used in a *note with: 6e9. block, the *note close(): 81c. method of the returned object will be called automatically at the end of the block. (Contributed by Serhiy Storchacha in bpo-16486(2).) The *note writeframesraw(): 81d. and *note writeframes(): 81e. methods now accept any *note bytes-like object: 5e8. (Contributed by Serhiy Storchaka in bpo-8311(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17818 (2) https://bugs.python.org/issue16486 (3) https://bugs.python.org/issue8311  File: python.info, Node: argparse<3>, Next: audioop, Prev: aifc<2>, Up: Improved Modules<5> 1.5.4.3 argparse ................ The *note FileType: 820. class now accepts `encoding' and `errors' arguments, which are passed through to *note open(): 4f0. (Contributed by Lucas Maystre in bpo-11175(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11175  File: python.info, Node: audioop, Next: base64, Prev: argparse<3>, Up: Improved Modules<5> 1.5.4.4 audioop ............... *note audioop: d. now supports 24-bit samples. (Contributed by Serhiy Storchaka in bpo-12866(1).) New *note byteswap(): 822. function converts big-endian samples to little-endian and vice versa. (Contributed by Serhiy Storchaka in bpo-19641(2).) All *note audioop: d. functions now accept any *note bytes-like object: 5e8. Strings are not accepted: they didn’t work before, now they raise an error right away. (Contributed by Serhiy Storchaka in bpo-16685(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12866 (2) https://bugs.python.org/issue19641 (3) https://bugs.python.org/issue16685  File: python.info, Node: base64, Next: collections<6>, Prev: audioop, Up: Improved Modules<5> 1.5.4.5 base64 .............. The encoding and decoding functions in *note base64: e. now accept any *note bytes-like object: 5e8. in cases where it previously required a *note bytes: 331. or *note bytearray: 332. instance. (Contributed by Nick Coghlan in bpo-17839(1).) New functions *note a85encode(): 824, *note a85decode(): 825, *note b85encode(): 826, and *note b85decode(): 827. provide the ability to encode and decode binary data from and to ‘Ascii85’ and the git/mercurial ‘Base85’ formats, respectively. The ‘a85’ functions have options that can be used to make them compatible with the variants of the ‘Ascii85’ encoding, including the Adobe variant. (Contributed by Martin Morrison, the Mercurial project, Serhiy Storchaka, and Antoine Pitrou in bpo-17618(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17839 (2) https://bugs.python.org/issue17618  File: python.info, Node: collections<6>, Next: colorsys, Prev: base64, Up: Improved Modules<5> 1.5.4.6 collections ................... The *note ChainMap.new_child(): 829. method now accepts an `m' argument specifying the child map to add to the chain. This allows an existing mapping and/or a custom mapping type to be used for the child. (Contributed by Vinay Sajip in bpo-16613(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16613  File: python.info, Node: colorsys, Next: contextlib<4>, Prev: collections<6>, Up: Improved Modules<5> 1.5.4.7 colorsys ................ The number of digits in the coefficients for the RGB — YIQ conversions have been expanded so that they match the FCC NTSC versions. The change in results should be less than 1% and may better match results found elsewhere. (Contributed by Brian Landers and Serhiy Storchaka in bpo-14323(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14323  File: python.info, Node: contextlib<4>, Next: dbm<5>, Prev: colorsys, Up: Improved Modules<5> 1.5.4.8 contextlib .................. The new *note contextlib.suppress: 82c. context manager helps to clarify the intent of code that deliberately suppresses exceptions from a single statement. (Contributed by Raymond Hettinger in bpo-15806(1) and Zero Piraeus in bpo-19266(2).) The new *note contextlib.redirect_stdout(): 6c2. context manager makes it easier for utility scripts to handle inflexible APIs that write their output to *note sys.stdout: 30e. and don’t provide any options to redirect it. Using the context manager, the *note sys.stdout: 30e. output can be redirected to any other stream or, in conjunction with *note io.StringIO: 82d, to a string. The latter can be especially useful, for example, to capture output from a function that was written to implement a command line interface. It is recommended only for utility scripts because it affects the global state of *note sys.stdout: 30e. (Contributed by Raymond Hettinger in bpo-15805(3).) The *note contextlib: 24. documentation has also been updated to include a *note discussion: 82e. of the differences between single use, reusable and reentrant context managers. ---------- Footnotes ---------- (1) https://bugs.python.org/issue15806 (2) https://bugs.python.org/issue19266 (3) https://bugs.python.org/issue15805  File: python.info, Node: dbm<5>, Next: dis<2>, Prev: contextlib<4>, Up: Improved Modules<5> 1.5.4.9 dbm ........... *note dbm.open(): 830. objects now support the context management protocol. When used in a *note with: 6e9. statement, the ‘close’ method of the database object will be called automatically at the end of the block. (Contributed by Claudiu Popa and Nick Coghlan in bpo-19282(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19282  File: python.info, Node: dis<2>, Next: doctest<2>, Prev: dbm<5>, Up: Improved Modules<5> 1.5.4.10 dis ............ Functions *note show_code(): 832, *note dis(): 384, *note distb(): 833, and *note disassemble(): 834. now accept a keyword-only `file' argument that controls where they write their output. The *note dis: 38. module is now built around an *note Instruction: 835. class that provides object oriented access to the details of each individual bytecode operation. A new method, *note get_instructions(): 836, provides an iterator that emits the Instruction stream for a given piece of Python code. Thus it is now possible to write a program that inspects and manipulates a bytecode object in ways different from those provided by the *note dis: 38. module itself. For example: >>> import dis >>> for instr in dis.get_instructions(lambda x: x + 1): ... print(instr.opname) LOAD_FAST LOAD_CONST BINARY_ADD RETURN_VALUE The various display tools in the *note dis: 38. module have been rewritten to use these new components. In addition, a new application-friendly class *note Bytecode: 837. provides an object-oriented API for inspecting bytecode in both in human-readable form and for iterating over instructions. The *note Bytecode: 837. constructor takes the same arguments that ‘get_instruction()’ does (plus an optional `current_offset'), and the resulting object can be iterated to produce *note Instruction: 835. objects. But it also has a *note dis: 838. method, equivalent to calling *note dis: 384. on the constructor argument, but returned as a multi-line string: >>> bytecode = dis.Bytecode(lambda x: x + 1, current_offset=3) >>> for instr in bytecode: ... print('{} ({})'.format(instr.opname, instr.opcode)) LOAD_FAST (124) LOAD_CONST (100) BINARY_ADD (23) RETURN_VALUE (83) >>> bytecode.dis().splitlines() [' 1 0 LOAD_FAST 0 (x)', ' --> 3 LOAD_CONST 1 (1)', ' 6 BINARY_ADD', ' 7 RETURN_VALUE'] *note Bytecode: 837. also has a class method, *note from_traceback(): 839, that provides the ability to manipulate a traceback (that is, ‘print(Bytecode.from_traceback(tb).dis())’ is equivalent to ‘distb(tb)’). (Contributed by Nick Coghlan, Ryan Kelly and Thomas Kluyver in bpo-11816(1) and Claudiu Popa in bpo-17916(2).) New function *note stack_effect(): 83a. computes the effect on the Python stack of a given opcode and argument, information that is not otherwise available. (Contributed by Larry Hastings in bpo-19722(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11816 (2) https://bugs.python.org/issue17916 (3) https://bugs.python.org/issue19722  File: python.info, Node: doctest<2>, Next: email<3>, Prev: dis<2>, Up: Improved Modules<5> 1.5.4.11 doctest ................ A new *note option flag: 83c, *note FAIL_FAST: 83d, halts test running as soon as the first failure is detected. (Contributed by R. David Murray and Daniel Urban in bpo-16522(1).) The *note doctest: 67. command line interface now uses *note argparse: 6, and has two new options, ‘-o’ and ‘-f’. ‘-o’ allows *note doctest options: 83c. to be specified on the command line, and ‘-f’ is a shorthand for ‘-o FAIL_FAST’ (to parallel the similar option supported by the *note unittest: 11b. CLI). (Contributed by R. David Murray in bpo-11390(2).) *note doctest: 67. will now find doctests in extension module ‘__doc__’ strings. (Contributed by Zachary Ware in bpo-3158(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16522 (2) https://bugs.python.org/issue11390 (3) https://bugs.python.org/issue3158  File: python.info, Node: email<3>, Next: filecmp, Prev: doctest<2>, Up: Improved Modules<5> 1.5.4.12 email .............. *note as_string(): 83f. now accepts a `policy' argument to override the default policy of the message when generating a string representation of it. This means that ‘as_string’ can now be used in more circumstances, instead of having to create and use a *note generator: 6e. in order to pass formatting parameters to its ‘flatten’ method. (Contributed by R. David Murray in bpo-18600(1).) New method *note as_bytes(): 840. added to produce a bytes representation of the message in a fashion similar to how ‘as_string’ produces a string representation. It does not accept the `maxheaderlen' argument, but does accept the `unixfrom' and `policy' arguments. The *note Message: 541. *note __bytes__(): 841. method calls it, meaning that ‘bytes(mymsg)’ will now produce the intuitive result: a bytes object containing the fully formatted message. (Contributed by R. David Murray in bpo-18600(2).) The *note Message.set_param(): 842. message now accepts a `replace' keyword argument. When specified, the associated header will be updated without changing its location in the list of headers. For backward compatibility, the default is ‘False’. (Contributed by R. David Murray in bpo-18891(3).) A pair of new subclasses of *note Message: 541. have been added (*note EmailMessage: 542. and *note MIMEPart: 843.), along with a new sub-module, *note contentmanager: 6b. and a new *note policy: 75. attribute *note content_manager: 844. All documentation is currently in the new module, which is being added as part of email’s new *note provisional API: 348. These classes provide a number of new methods that make extracting content from and inserting content into email messages much easier. For details, see the *note contentmanager: 6b. documentation and the *note email; Examples: 845. These API additions complete the bulk of the work that was planned as part of the email6 project. The currently provisional API is scheduled to become final in Python 3.5 (possibly with a few minor additions in the area of error handling). (Contributed by R. David Murray in bpo-18891(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18600 (2) https://bugs.python.org/issue18600 (3) https://bugs.python.org/issue18891 (4) https://bugs.python.org/issue18891  File: python.info, Node: filecmp, Next: functools<4>, Prev: email<3>, Up: Improved Modules<5> 1.5.4.13 filecmp ................ A new *note clear_cache(): 847. function provides the ability to clear the *note filecmp: 7f. comparison cache, which uses *note os.stat(): 1f1. information to determine if the file has changed since the last compare. This can be used, for example, if the file might have been changed and re-checked in less time than the resolution of a particular filesystem’s file modification time field. (Contributed by Mark Levitt in bpo-18149(1).) New module attribute *note DEFAULT_IGNORES: 848. provides the list of directories that are used as the default value for the `ignore' parameter of the *note dircmp(): 849. function. (Contributed by Eli Bendersky in bpo-15442(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18149 (2) https://bugs.python.org/issue15442  File: python.info, Node: functools<4>, Next: gc<3>, Prev: filecmp, Up: Improved Modules<5> 1.5.4.14 functools .................. The new *note partialmethod(): 29c. descriptor brings partial argument application to descriptors, just as *note partial(): 7c8. provides for normal callables. The new descriptor also makes it easier to get arbitrary callables (including *note partial(): 7c8. instances) to behave like normal instance methods when included in a class definition. (Contributed by Alon Horev and Nick Coghlan in bpo-4331(1).) The new *note singledispatch(): 38a. decorator brings support for single-dispatch generic functions to the Python standard library. Where object oriented programming focuses on grouping multiple operations on a common set of data into a class, a generic function focuses on grouping multiple implementations of an operation that allows it to work with `different' kinds of data. See also ........ PEP 443(2) – Single-dispatch generic functions PEP written and implemented by Łukasz Langa. *note total_ordering(): 84b. now supports a return value of *note NotImplemented: 84c. from the underlying comparison function. (Contributed by Katie Miller in bpo-10042(3).) A pure-python version of the *note partial(): 7c8. function is now in the stdlib; in CPython it is overridden by the C accelerated version, but it is available for other implementations to use. (Contributed by Brian Thorne in bpo-12428(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4331 (2) https://www.python.org/dev/peps/pep-0443 (3) https://bugs.python.org/issue10042 (4) https://bugs.python.org/issue12428  File: python.info, Node: gc<3>, Next: glob<2>, Prev: functools<4>, Up: Improved Modules<5> 1.5.4.15 gc ........... New function *note get_stats(): 84e. returns a list of three per-generation dictionaries containing the collections statistics since interpreter startup. (Contributed by Antoine Pitrou in bpo-16351(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16351  File: python.info, Node: glob<2>, Next: hashlib<2>, Prev: gc<3>, Up: Improved Modules<5> 1.5.4.16 glob ............. A new function *note escape(): 850. provides a way to escape special characters in a filename so that they do not become part of the globbing expansion but are instead matched literally. (Contributed by Serhiy Storchaka in bpo-8402(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8402  File: python.info, Node: hashlib<2>, Next: hmac<2>, Prev: glob<2>, Up: Improved Modules<5> 1.5.4.17 hashlib ................ A new *note hashlib.pbkdf2_hmac(): 7e6. function provides the PKCS#5 password-based key derivation function 2(1). (Contributed by Christian Heimes in bpo-18582(2).) The *note name: 852. attribute of *note hashlib: 8d. hash objects is now a formally supported interface. It has always existed in CPython’s *note hashlib: 8d. (although it did not return lower case names for all supported hashes), but it was not a public interface and so some other Python implementations have not previously supported it. (Contributed by Jason R. Coombs in bpo-18532(3).) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/PBKDF2 (2) https://bugs.python.org/issue18582 (3) https://bugs.python.org/issue18532  File: python.info, Node: hmac<2>, Next: html, Prev: hashlib<2>, Up: Improved Modules<5> 1.5.4.18 hmac ............. *note hmac: 8f. now accepts ‘bytearray’ as well as ‘bytes’ for the `key' argument to the *note new(): 854. function, and the `msg' parameter to both the *note new(): 854. function and the *note update(): 855. method now accepts any type supported by the *note hashlib: 8d. module. (Contributed by Jonas Borgström in bpo-18240(1).) The `digestmod' argument to the *note hmac.new(): 854. function may now be any hash digest name recognized by *note hashlib: 8d. In addition, the current behavior in which the value of `digestmod' defaults to ‘MD5’ is deprecated: in a future version of Python there will be no default value. (Contributed by Christian Heimes in bpo-17276(2).) With the addition of *note block_size: 856. and *note name: 857. attributes (and the formal documentation of the *note digest_size: 858. attribute), the *note hmac: 8f. module now conforms fully to the PEP 247(3) API. (Contributed by Christian Heimes in bpo-18775(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18240 (2) https://bugs.python.org/issue17276 (3) https://www.python.org/dev/peps/pep-0247 (4) https://bugs.python.org/issue18775  File: python.info, Node: html, Next: http<2>, Prev: hmac<2>, Up: Improved Modules<5> 1.5.4.19 html ............. New function *note unescape(): 85a. function converts HTML5 character references to the corresponding Unicode characters. (Contributed by Ezio Melotti in bpo-2927(1).) *note HTMLParser: 7bf. accepts a new keyword argument `convert_charrefs' that, when ‘True’, automatically converts all character references. For backward-compatibility, its value defaults to ‘False’, but it will change to ‘True’ in a future version of Python, so you are invited to set it explicitly and update your code to use this new feature. (Contributed by Ezio Melotti in bpo-13633(2).) The `strict' argument of *note HTMLParser: 7bf. is now deprecated. (Contributed by Ezio Melotti in bpo-15114(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2927 (2) https://bugs.python.org/issue13633 (3) https://bugs.python.org/issue15114  File: python.info, Node: http<2>, Next: idlelib and IDLE<4>, Prev: html, Up: Improved Modules<5> 1.5.4.20 http ............. *note send_error(): 85c. now accepts an optional additional `explain' parameter which can be used to provide an extended error description, overriding the hardcoded default if there is one. This extended error description will be formatted using the ‘error_message_format’ attribute and sent as the body of the error response. (Contributed by Karl Cow in bpo-12921(1).) The *note http.server: 97. *note command line interface: 85d. now has a ‘-b/--bind’ option that causes the server to listen on a specific address. (Contributed by Malte Swart in bpo-17764(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12921 (2) https://bugs.python.org/issue17764  File: python.info, Node: idlelib and IDLE<4>, Next: importlib<6>, Prev: http<2>, Up: Improved Modules<5> 1.5.4.21 idlelib and IDLE ......................... Since idlelib implements the IDLE shell and editor and is not intended for import by other programs, it gets improvements with every release. See ‘Lib/idlelib/NEWS.txt’ for a cumulative list of changes since 3.3.0, as well as changes made in future 3.4.x releases. This file is also available from the IDLE Help ‣ About IDLE dialog.  File: python.info, Node: importlib<6>, Next: inspect<4>, Prev: idlelib and IDLE<4>, Up: Improved Modules<5> 1.5.4.22 importlib .................. The *note InspectLoader: 860. ABC defines a new method, *note source_to_code(): 6ef. that accepts source data and a path and returns a code object. The default implementation is equivalent to ‘compile(data, path, 'exec', dont_inherit=True)’. (Contributed by Eric Snow and Brett Cannon in bpo-15627(1).) *note InspectLoader: 860. also now has a default implementation for the *note get_code(): 861. method. However, it will normally be desirable to override the default implementation for performance reasons. (Contributed by Brett Cannon in bpo-18072(2).) The *note reload(): 399. function has been moved from *note imp: 9a. to *note importlib: 9b. as part of the *note imp: 9a. module deprecation. (Contributed by Berker Peksag in bpo-18193(3).) *note importlib.util: 9f. now has a *note MAGIC_NUMBER: 862. attribute providing access to the bytecode version number. This replaces the *note get_magic(): 863. function in the deprecated *note imp: 9a. module. (Contributed by Brett Cannon in bpo-18192(4).) New *note importlib.util: 9f. functions *note cache_from_source(): 557. and *note source_from_cache(): 558. replace the same-named functions in the deprecated *note imp: 9a. module. (Contributed by Brett Cannon in bpo-18194(5).) The *note importlib: 9b. bootstrap ‘NamespaceLoader’ now conforms to the *note InspectLoader: 860. ABC, which means that ‘runpy’ and ‘python -m’ can now be used with namespace packages. (Contributed by Brett Cannon in bpo-18058(6).) *note importlib.util: 9f. has a new function *note decode_source(): 864. that decodes source from bytes using universal newline processing. This is useful for implementing *note InspectLoader.get_source(): 865. methods. *note importlib.machinery.ExtensionFileLoader: 556. now has a *note get_filename(): 866. method. This was inadvertently omitted in the original implementation. (Contributed by Eric Snow in bpo-19152(7).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15627 (2) https://bugs.python.org/issue18072 (3) https://bugs.python.org/issue18193 (4) https://bugs.python.org/issue18192 (5) https://bugs.python.org/issue18194 (6) https://bugs.python.org/issue18058 (7) https://bugs.python.org/issue19152  File: python.info, Node: inspect<4>, Next: ipaddress<3>, Prev: importlib<6>, Up: Improved Modules<5> 1.5.4.23 inspect ................ The *note inspect: a0. module now offers a basic *note command line interface: 868. to quickly display source code and other information for modules, classes and functions. (Contributed by Claudiu Popa and Nick Coghlan in bpo-18626(1).) *note unwrap(): 869. makes it easy to unravel wrapper function chains created by *note functools.wraps(): 86a. (and any other API that sets the ‘__wrapped__’ attribute on a wrapper function). (Contributed by Daniel Urban, Aaron Iles and Nick Coghlan in bpo-13266(2).) As part of the implementation of the new *note enum: 7b. module, the *note inspect: a0. module now has substantially better support for custom ‘__dir__’ methods and dynamic class attributes provided through metaclasses. (Contributed by Ethan Furman in bpo-18929(3) and bpo-19030(4).) *note getfullargspec(): 55d. and *note getargspec(): 55c. now use the *note signature(): 55b. API. This allows them to support a much broader range of callables, including those with ‘__signature__’ attributes, those with metadata provided by argument clinic, *note functools.partial(): 7c8. objects and more. Note that, unlike *note signature(): 55b, these functions still ignore ‘__wrapped__’ attributes, and report the already bound first argument for bound methods, so it is still necessary to update your code to use *note signature(): 55b. directly if those features are desired. (Contributed by Yury Selivanov in bpo-17481(5).) *note signature(): 55b. now supports duck types of CPython functions, which adds support for functions compiled with Cython. (Contributed by Stefan Behnel and Yury Selivanov in bpo-17159(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18626 (2) https://bugs.python.org/issue13266 (3) https://bugs.python.org/issue18929 (4) https://bugs.python.org/issue19030 (5) https://bugs.python.org/issue17481 (6) https://bugs.python.org/issue17159  File: python.info, Node: ipaddress<3>, Next: logging<5>, Prev: inspect<4>, Up: Improved Modules<5> 1.5.4.24 ipaddress .................. *note ipaddress: a2. was added to the standard library in Python 3.3 as a *note provisional API: 348. With the release of Python 3.4, this qualification has been removed: *note ipaddress: a2. is now considered a stable API, covered by the normal standard library requirements to maintain backwards compatibility. A new *note is_global: 86c. property is ‘True’ if an address is globally routeable. (Contributed by Peter Moody in bpo-17400(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17400  File: python.info, Node: logging<5>, Next: marshal, Prev: ipaddress<3>, Up: Improved Modules<5> 1.5.4.25 logging ................ The *note TimedRotatingFileHandler: 86e. has a new `atTime' parameter that can be used to specify the time of day when rollover should happen. (Contributed by Ronald Oussoren in bpo-9556(1).) *note SocketHandler: 86f. and *note DatagramHandler: 870. now support Unix domain sockets (by setting `port' to ‘None’). (Contributed by Vinay Sajip in commit ce46195b56a9.) *note fileConfig(): 3a9. now accepts a *note configparser.RawConfigParser: 871. subclass instance for the `fname' parameter. This facilitates using a configuration file when logging configuration is just a part of the overall application configuration, or where the application modifies the configuration before passing it to *note fileConfig(): 3a9. (Contributed by Vinay Sajip in bpo-16110(2).) Logging configuration data received from a socket via the *note logging.config.listen(): 872. function can now be validated before being processed by supplying a verification function as the argument to the new `verify' keyword argument. (Contributed by Vinay Sajip in bpo-15452(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9556 (2) https://bugs.python.org/issue16110 (3) https://bugs.python.org/issue15452  File: python.info, Node: marshal, Next: mmap<2>, Prev: logging<5>, Up: Improved Modules<5> 1.5.4.26 marshal ................ The default *note marshal: b0. version has been bumped to 3. The code implementing the new version restores the Python2 behavior of recording only one copy of interned strings and preserving the interning on deserialization, and extends this “one copy” ability to any object type (including handling recursive references). This reduces both the size of ‘.pyc’ files and the amount of memory a module occupies in memory when it is loaded from a ‘.pyc’ (or ‘.pyo’) file. (Contributed by Kristján Valur Jónsson in bpo-16475(1), with additional speedups by Antoine Pitrou in bpo-19219(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16475 (2) https://bugs.python.org/issue19219  File: python.info, Node: mmap<2>, Next: multiprocessing<5>, Prev: marshal, Up: Improved Modules<5> 1.5.4.27 mmap ............. mmap objects can now be *note weakref: 128.ed. (Contributed by Valerie Lambert in bpo-4885(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4885  File: python.info, Node: multiprocessing<5>, Next: operator<2>, Prev: mmap<2>, Up: Improved Modules<5> 1.5.4.28 multiprocessing ........................ On Unix two new *note start methods: 876, ‘spawn’ and ‘forkserver’, have been added for starting processes using *note multiprocessing: b7. These make the mixing of processes with threads more robust, and the ‘spawn’ method matches the semantics that multiprocessing has always used on Windows. New function *note get_all_start_methods(): 877. reports all start methods available on the platform, *note get_start_method(): 878. reports the current start method, and *note set_start_method(): 879. sets the start method. (Contributed by Richard Oudkerk in bpo-8713(1).) *note multiprocessing: b7. also now has the concept of a ‘context’, which determines how child processes are created. New function *note get_context(): 87a. returns a context that uses a specified start method. It has the same API as the *note multiprocessing: b7. module itself, so you can use it to create *note Pool: 87b.s and other objects that will operate within that context. This allows a framework and an application or different parts of the same application to use multiprocessing without interfering with each other. (Contributed by Richard Oudkerk in bpo-18999(2).) Except when using the old `fork' start method, child processes no longer inherit unneeded handles/file descriptors from their parents (part of bpo-8713(3)). *note multiprocessing: b7. now relies on *note runpy: e2. (which implements the ‘-m’ switch) to initialise ‘__main__’ appropriately in child processes when using the ‘spawn’ or ‘forkserver’ start methods. This resolves some edge cases where combining multiprocessing, the ‘-m’ command line switch, and explicit relative imports could cause obscure failures in child processes. (Contributed by Nick Coghlan in bpo-19946(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8713 (2) https://bugs.python.org/issue18999 (3) https://bugs.python.org/issue8713 (4) https://bugs.python.org/issue19946  File: python.info, Node: operator<2>, Next: os<6>, Prev: multiprocessing<5>, Up: Improved Modules<5> 1.5.4.29 operator ................. New function *note length_hint(): 87d. provides an implementation of the specification for how the *note __length_hint__(): 80c. special method should be used, as part of the PEP 424(1) formal specification of this language feature. (Contributed by Armin Ronacher in bpo-16148(2).) There is now a pure-python version of the *note operator: c2. module available for reference and for use by alternate implementations of Python. (Contributed by Zachary Ware in bpo-16694(3).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0424 (2) https://bugs.python.org/issue16148 (3) https://bugs.python.org/issue16694  File: python.info, Node: os<6>, Next: pdb<3>, Prev: operator<2>, Up: Improved Modules<5> 1.5.4.30 os ........... There are new functions to get and set the *note inheritable flag: 7fa. of a file descriptor (*note os.get_inheritable(): 7fb, *note os.set_inheritable(): 7fc.) or a Windows handle (*note os.get_handle_inheritable(): 7fd, *note os.set_handle_inheritable(): 7fe.). New function *note cpu_count(): 87f. reports the number of CPUs available on the platform on which Python is running (or ‘None’ if the count can’t be determined). The *note multiprocessing.cpu_count(): 880. function is now implemented in terms of this function). (Contributed by Trent Nelson, Yogesh Chaudhari, Victor Stinner, and Charles-François Natali in bpo-17914(1).) *note os.path.samestat(): 881. is now available on the Windows platform (and the *note os.path.samefile(): 882. implementation is now shared between Unix and Windows). (Contributed by Brian Curtin in bpo-11939(2).) *note os.path.ismount(): 1fa. now recognizes volumes mounted below a drive root on Windows. (Contributed by Tim Golden in bpo-9035(3).) *note os.open(): 665. supports two new flags on platforms that provide them, *note O_PATH: 883. (un-opened file descriptor), and *note O_TMPFILE: 884. (unnamed temporary file; as of 3.4.0 release available only on Linux systems with a kernel version of 3.11 or newer that have uapi headers). (Contributed by Christian Heimes in bpo-18673(4) and Benjamin Peterson, respectively.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17914 (2) https://bugs.python.org/issue11939 (3) https://bugs.python.org/issue9035 (4) https://bugs.python.org/issue18673  File: python.info, Node: pdb<3>, Next: pickle<4>, Prev: os<6>, Up: Improved Modules<5> 1.5.4.31 pdb ............ *note pdb: c9. has been enhanced to handle generators, *note yield: 18f, and ‘yield from’ in a more useful fashion. This is especially helpful when debugging *note asyncio: a. based programs. (Contributed by Andrew Svetlov and Xavier de Gaye in bpo-16596(1).) The ‘print’ command has been removed from *note pdb: c9, restoring access to the Python *note print(): 886. function from the pdb command line. Python2’s ‘pdb’ did not have a ‘print’ command; instead, entering ‘print’ executed the ‘print’ statement. In Python3 ‘print’ was mistakenly made an alias for the pdb *note p: 887. command. ‘p’, however, prints the ‘repr’ of its argument, not the ‘str’ like the Python2 ‘print’ command did. Worse, the Python3 ‘pdb print’ command shadowed the Python3 ‘print’ function, making it inaccessible at the ‘pdb’ prompt. (Contributed by Connor Osborn in bpo-18764(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16596 (2) https://bugs.python.org/issue18764  File: python.info, Node: pickle<4>, Next: plistlib<2>, Prev: pdb<3>, Up: Improved Modules<5> 1.5.4.32 pickle ............... *note pickle: ca. now supports (but does not use by default) a new pickle protocol, protocol 4. This new protocol addresses a number of issues that were present in previous protocols, such as the serialization of nested classes, very large strings and containers, and classes whose *note __new__(): 889. method takes keyword-only arguments. It also provides some efficiency improvements. See also ........ PEP 3154(1) – Pickle protocol 4 PEP written by Antoine Pitrou and implemented by Alexandre Vassalotti. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3154  File: python.info, Node: plistlib<2>, Next: poplib<2>, Prev: pickle<4>, Up: Improved Modules<5> 1.5.4.33 plistlib ................. *note plistlib: cf. now has an API that is similar to the standard pattern for stdlib serialization protocols, with new *note load(): 88b, *note dump(): 88c, *note loads(): 88d, and *note dumps(): 88e. functions. (The older API is now deprecated.) In addition to the already supported XML plist format (*note FMT_XML: 88f.), it also now supports the binary plist format (*note FMT_BINARY: 890.). (Contributed by Ronald Oussoren and others in bpo-14455(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14455  File: python.info, Node: poplib<2>, Next: pprint<2>, Prev: plistlib<2>, Up: Improved Modules<5> 1.5.4.34 poplib ............... Two new methods have been added to *note poplib: d0.: *note capa(): 892, which returns the list of capabilities advertised by the POP server, and *note stls(): 893, which switches a clear-text POP3 session into an encrypted POP3 session if the POP server supports it. (Contributed by Lorenzo Catucci in bpo-4473(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4473  File: python.info, Node: pprint<2>, Next: pty, Prev: poplib<2>, Up: Improved Modules<5> 1.5.4.35 pprint ............... The *note pprint: d2. module’s *note PrettyPrinter: 895. class and its *note pformat(): 896, and *note pprint(): 213. functions have a new option, `compact', that controls how the output is formatted. Currently setting `compact' to ‘True’ means that sequences will be printed with as many sequence elements as will fit within `width' on each (indented) line. (Contributed by Serhiy Storchaka in bpo-19132(1).) Long strings are now wrapped using Python’s normal line continuation syntax. (Contributed by Antoine Pitrou in bpo-17150(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19132 (2) https://bugs.python.org/issue17150  File: python.info, Node: pty, Next: pydoc<3>, Prev: pprint<2>, Up: Improved Modules<5> 1.5.4.36 pty ............ *note pty.spawn(): 898. now returns the status value from *note os.waitpid(): 66d. on the child process, instead of ‘None’. (Contributed by Gregory P. Smith.)  File: python.info, Node: pydoc<3>, Next: re<5>, Prev: pty, Up: Improved Modules<5> 1.5.4.37 pydoc .............. The *note pydoc: d9. module is now based directly on the *note inspect.signature(): 55b. introspection API, allowing it to provide signature information for a wider variety of callable objects. This change also means that ‘__wrapped__’ attributes are now taken into account when displaying help information. (Contributed by Larry Hastings in bpo-19674(1).) The *note pydoc: d9. module no longer displays the ‘self’ parameter for already bound methods. Instead, it aims to always display the exact current signature of the supplied callable. (Contributed by Larry Hastings in bpo-20710(2).) In addition to the changes that have been made to *note pydoc: d9. directly, its handling of custom ‘__dir__’ methods and various descriptor behaviours has also been improved substantially by the underlying changes in the *note inspect: a0. module. As the *note help(): 572. builtin is based on *note pydoc: d9, the above changes also affect the behaviour of *note help(): 572. ---------- Footnotes ---------- (1) https://bugs.python.org/issue19674 (2) https://bugs.python.org/issue20710  File: python.info, Node: re<5>, Next: resource, Prev: pydoc<3>, Up: Improved Modules<5> 1.5.4.38 re ........... New *note fullmatch(): 89b. function and ‘regex.fullmatch()’ method anchor the pattern at both ends of the string to match. This provides a way to be explicit about the goal of the match, which avoids a class of subtle bugs where ‘$’ characters get lost during code changes or the addition of alternatives to an existing regular expression. (Contributed by Matthew Barnett in bpo-16203(1).) The repr of *note regex objects: 89c. now includes the pattern and the flags; the repr of *note match objects: 89d. now includes the start, end, and the part of the string that matched. (Contributed by Hugo Lopes Tavares and Serhiy Storchaka in bpo-13592(2) and bpo-17087(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16203 (2) https://bugs.python.org/issue13592 (3) https://bugs.python.org/issue17087  File: python.info, Node: resource, Next: select, Prev: re<5>, Up: Improved Modules<5> 1.5.4.39 resource ................. New *note prlimit(): 89f. function, available on Linux platforms with a kernel version of 2.6.36 or later and glibc of 2.13 or later, provides the ability to query or set the resource limits for processes other than the one making the call. (Contributed by Christian Heimes in bpo-16595(1).) On Linux kernel version 2.6.36 or later, there are also some new Linux specific constants: *note RLIMIT_MSGQUEUE: 8a0, *note RLIMIT_NICE: 8a1, *note RLIMIT_RTPRIO: 8a2, *note RLIMIT_RTTIME: 8a3, and *note RLIMIT_SIGPENDING: 8a4. (Contributed by Christian Heimes in bpo-19324(2).) On FreeBSD version 9 and later, there some new FreeBSD specific constants: *note RLIMIT_SBSIZE: 8a5, *note RLIMIT_SWAP: 8a6, and *note RLIMIT_NPTS: 8a7. (Contributed by Claudiu Popa in bpo-19343(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16595 (2) https://bugs.python.org/issue19324 (3) https://bugs.python.org/issue19343  File: python.info, Node: select, Next: shelve, Prev: resource, Up: Improved Modules<5> 1.5.4.40 select ............... *note epoll: 8a9. objects now support the context management protocol. When used in a *note with: 6e9. statement, the *note close(): 8aa. method will be called automatically at the end of the block. (Contributed by Serhiy Storchaka in bpo-16488(1).) *note devpoll: 8ab. objects now have *note fileno(): 8ac. and *note close(): 8ad. methods, as well as a new attribute *note closed: 8ae. (Contributed by Victor Stinner in bpo-18794(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16488 (2) https://bugs.python.org/issue18794  File: python.info, Node: shelve, Next: shutil<3>, Prev: select, Up: Improved Modules<5> 1.5.4.41 shelve ............... *note Shelf: 8b0. instances may now be used in *note with: 6e9. statements, and will be automatically closed at the end of the ‘with’ block. (Contributed by Filip Gruszczyński in bpo-13896(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13896  File: python.info, Node: shutil<3>, Next: smtpd<2>, Prev: shelve, Up: Improved Modules<5> 1.5.4.42 shutil ............... *note copyfile(): 258. now raises a specific *note Error: 8b2. subclass, *note SameFileError: 8b3, when the source and destination are the same file, which allows an application to take appropriate action on this specific error. (Contributed by Atsuo Ishimoto and Hynek Schlawack in bpo-1492704(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1492704  File: python.info, Node: smtpd<2>, Next: smtplib<2>, Prev: shutil<3>, Up: Improved Modules<5> 1.5.4.43 smtpd .............. The *note SMTPServer: 602. and *note SMTPChannel: 601. classes now accept a `map' keyword argument which, if specified, is passed in to *note asynchat.async_chat: 8b5. as its `map' argument. This allows an application to avoid affecting the global socket map. (Contributed by Vinay Sajip in bpo-11959(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11959  File: python.info, Node: smtplib<2>, Next: socket<6>, Prev: smtpd<2>, Up: Improved Modules<5> 1.5.4.44 smtplib ................ *note SMTPException: 8b7. is now a subclass of *note OSError: 1d3, which allows both socket level errors and SMTP protocol level errors to be caught in one try/except statement by code that only cares whether or not an error occurred. (Contributed by Ned Jackson Lovely in bpo-2118(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2118  File: python.info, Node: socket<6>, Next: sqlite3<4>, Prev: smtplib<2>, Up: Improved Modules<5> 1.5.4.45 socket ............... The socket module now supports the *note CAN_BCM: 8b9. protocol on platforms that support it. (Contributed by Brian Thorne in bpo-15359(1).) Socket objects have new methods to get or set their *note inheritable flag: 7fa, *note get_inheritable(): 7ff. and *note set_inheritable(): 800. The ‘socket.AF_*’ and ‘socket.SOCK_*’ constants are now enumeration values using the new *note enum: 7b. module. This allows meaningful names to be printed during debugging, instead of integer “magic numbers”. The *note AF_LINK: 8ba. constant is now available on BSD and OSX. *note inet_pton(): 8bb. and *note inet_ntop(): 8bc. are now supported on Windows. (Contributed by Atsuo Ishimoto in bpo-7171(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15359 (2) https://bugs.python.org/issue7171  File: python.info, Node: sqlite3<4>, Next: ssl<7>, Prev: socket<6>, Up: Improved Modules<5> 1.5.4.46 sqlite3 ................ A new boolean parameter to the *note connect(): 3da. function, `uri', can be used to indicate that the `database' parameter is a ‘uri’ (see the SQLite URI documentation(1)). (Contributed by poq in bpo-13773(2).) ---------- Footnotes ---------- (1) https://www.sqlite.org/uri.html (2) https://bugs.python.org/issue13773  File: python.info, Node: ssl<7>, Next: stat, Prev: sqlite3<4>, Up: Improved Modules<5> 1.5.4.47 ssl ............ *note PROTOCOL_TLSv1_1: 8bf. and *note PROTOCOL_TLSv1_2: 8c0. (TLSv1.1 and TLSv1.2 support) have been added; support for these protocols is only available if Python is linked with OpenSSL 1.0.1 or later. (Contributed by Michele Orrù and Antoine Pitrou in bpo-16692(1).) New function *note create_default_context(): 8c1. provides a standard way to obtain an *note SSLContext: 3e4. whose settings are intended to be a reasonable balance between compatibility and security. These settings are more stringent than the defaults provided by the *note SSLContext: 3e4. constructor, and may be adjusted in the future, without prior deprecation, if best-practice security requirements change. The new recommended best practice for using stdlib libraries that support SSL is to use *note create_default_context(): 8c1. to obtain an *note SSLContext: 3e4. object, modify it if needed, and then pass it as the `context' argument of the appropriate stdlib API. (Contributed by Christian Heimes in bpo-19689(2).) *note SSLContext: 3e4. method *note load_verify_locations(): 7eb. accepts a new optional argument `cadata', which can be used to provide PEM or DER encoded certificates directly via strings or bytes, respectively. (Contributed by Christian Heimes in bpo-18138(3).) New function *note get_default_verify_paths(): 8c2. returns a named tuple of the paths and environment variables that the *note set_default_verify_paths(): 8c3. method uses to set OpenSSL’s default ‘cafile’ and ‘capath’. This can be an aid in debugging default verification issues. (Contributed by Christian Heimes in bpo-18143(4).) *note SSLContext: 3e4. has a new method, *note cert_store_stats(): 8c4, that reports the number of loaded ‘X.509’ certs, ‘X.509 CA’ certs, and certificate revocation lists (‘crl’s), as well as a *note get_ca_certs(): 8c5. method that returns a list of the loaded ‘CA’ certificates. (Contributed by Christian Heimes in bpo-18147(5).) If OpenSSL 0.9.8 or later is available, *note SSLContext: 3e4. has a new attribute *note verify_flags: 8c6. that can be used to control the certificate verification process by setting it to some combination of the new constants *note VERIFY_DEFAULT: 8c7, *note VERIFY_CRL_CHECK_LEAF: 8c8, *note VERIFY_CRL_CHECK_CHAIN: 8c9, or *note VERIFY_X509_STRICT: 8ca. OpenSSL does not do any CRL verification by default. (Contributed by Christien Heimes in bpo-8813(6).) New *note SSLContext: 3e4. method *note load_default_certs(): 8cb. loads a set of default “certificate authority” (CA) certificates from default locations, which vary according to the platform. It can be used to load both TLS web server authentication certificates (‘purpose=’*note SERVER_AUTH: 8cc.) for a client to use to verify a server, and certificates for a server to use in verifying client certificates (‘purpose=’*note CLIENT_AUTH: 8cd.). (Contributed by Christian Heimes in bpo-19292(7).) Two new windows-only functions, *note enum_certificates(): 8ce. and *note enum_crls(): 8cf. provide the ability to retrieve certificates, certificate information, and CRLs from the Windows cert store. (Contributed by Christian Heimes in bpo-17134(8).) Support for server-side SNI (Server Name Indication) using the new *note ssl.SSLContext.set_servername_callback(): 8d0. method. (Contributed by Daniel Black in bpo-8109(9).) The dictionary returned by *note SSLSocket.getpeercert(): 8d1. contains additional ‘X509v3’ extension items: ‘crlDistributionPoints’, ‘calIssuers’, and ‘OCSP’ URIs. (Contributed by Christian Heimes in bpo-18379(10).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16692 (2) https://bugs.python.org/issue19689 (3) https://bugs.python.org/issue18138 (4) https://bugs.python.org/issue18143 (5) https://bugs.python.org/issue18147 (6) https://bugs.python.org/issue8813 (7) https://bugs.python.org/issue19292 (8) https://bugs.python.org/issue17134 (9) https://bugs.python.org/issue8109 (10) https://bugs.python.org/issue18379  File: python.info, Node: stat, Next: struct<2>, Prev: ssl<7>, Up: Improved Modules<5> 1.5.4.48 stat ............. The *note stat: f4. module is now backed by a C implementation in ‘_stat’. A C implementation is required as most of the values aren’t standardized and are platform-dependent. (Contributed by Christian Heimes in bpo-11016(1).) The module supports new *note ST_MODE: 8d3. flags, *note S_IFDOOR: 8d4, *note S_IFPORT: 8d5, and *note S_IFWHT: 8d6. (Contributed by Christian Hiemes in bpo-11016(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11016 (2) https://bugs.python.org/issue11016  File: python.info, Node: struct<2>, Next: subprocess<4>, Prev: stat, Up: Improved Modules<5> 1.5.4.49 struct ............... New function *note iter_unpack: 8d8. and a new *note struct.Struct.iter_unpack(): 8d9. method on compiled formats provide streamed unpacking of a buffer containing repeated instances of a given format of data. (Contributed by Antoine Pitrou in bpo-17804(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17804  File: python.info, Node: subprocess<4>, Next: sunau<2>, Prev: struct<2>, Up: Improved Modules<5> 1.5.4.50 subprocess ................... *note check_output(): 8db. now accepts an `input' argument that can be used to provide the contents of ‘stdin’ for the command that is run. (Contributed by Zack Weinberg in bpo-16624(1).) ‘getstatus()’ and *note getstatusoutput(): 8dc. now work on Windows. This change was actually inadvertently made in 3.3.4. (Contributed by Tim Golden in bpo-10197(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16624 (2) https://bugs.python.org/issue10197  File: python.info, Node: sunau<2>, Next: sys<6>, Prev: subprocess<4>, Up: Improved Modules<5> 1.5.4.51 sunau .............. The ‘getparams()’ method now returns a namedtuple rather than a plain tuple. (Contributed by Claudiu Popa in bpo-18901(1).) *note sunau.open(): 472. now supports the context management protocol: when used in a *note with: 6e9. block, the ‘close’ method of the returned object will be called automatically at the end of the block. (Contributed by Serhiy Storchaka in bpo-18878(2).) *note AU_write.setsampwidth(): 8de. now supports 24 bit samples, thus adding support for writing 24 sample using the module. (Contributed by Serhiy Storchaka in bpo-19261(3).) The *note writeframesraw(): 8df. and *note writeframes(): 8e0. methods now accept any *note bytes-like object: 5e8. (Contributed by Serhiy Storchaka in bpo-8311(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18901 (2) https://bugs.python.org/issue18878 (3) https://bugs.python.org/issue19261 (4) https://bugs.python.org/issue8311  File: python.info, Node: sys<6>, Next: tarfile<3>, Prev: sunau<2>, Up: Improved Modules<5> 1.5.4.52 sys ............ New function *note sys.getallocatedblocks(): 8e2. returns the current number of blocks allocated by the interpreter. (In CPython with the default ‘--with-pymalloc’ setting, this is allocations made through the *note PyObject_Malloc(): 508. API.) This can be useful for tracking memory leaks, especially if automated via a test suite. (Contributed by Antoine Pitrou in bpo-13390(1).) When the Python interpreter starts in *note interactive mode: 8e3, it checks for an *note __interactivehook__: 8e4. attribute on the *note sys: fd. module. If the attribute exists, its value is called with no arguments just before interactive mode is started. The check is made after the *note PYTHONSTARTUP: 8e5. file is read, so it can be set there. The *note site: eb. module *note sets it: 8e6. to a function that enables tab completion and history saving (in ‘~/.python-history’) if the platform supports *note readline: de. If you do not want this (new) behavior, you can override it in *note PYTHONSTARTUP: 8e5, ‘sitecustomize’, or ‘usercustomize’ by deleting this attribute from *note sys: fd. (or setting it to some other callable). (Contributed by Éric Araujo and Antoine Pitrou in bpo-5845(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13390 (2) https://bugs.python.org/issue5845  File: python.info, Node: tarfile<3>, Next: textwrap, Prev: sys<6>, Up: Improved Modules<5> 1.5.4.53 tarfile ................ The *note tarfile: 101. module now supports a simple *note Command-Line Interface: 8e8. when called as a script directly or via ‘-m’. This can be used to create and extract tarfile archives. (Contributed by Berker Peksag in bpo-13477(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13477  File: python.info, Node: textwrap, Next: threading<4>, Prev: tarfile<3>, Up: Improved Modules<5> 1.5.4.54 textwrap ................. The *note TextWrapper: 8ea. class has two new attributes/constructor arguments: *note max_lines: 8eb, which limits the number of lines in the output, and *note placeholder: 8ec, which is a string that will appear at the end of the output if it has been truncated because of `max_lines'. Building on these capabilities, a new convenience function *note shorten(): 8ed. collapses all of the whitespace in the input to single spaces and produces a single line of a given `width' that ends with the `placeholder' (by default, ‘[...]’). (Contributed by Antoine Pitrou and Serhiy Storchaka in bpo-18585(1) and bpo-18725(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18585 (2) https://bugs.python.org/issue18725  File: python.info, Node: threading<4>, Next: traceback<3>, Prev: textwrap, Up: Improved Modules<5> 1.5.4.55 threading .................. The *note Thread: 235. object representing the main thread can be obtained from the new *note main_thread(): 8ef. function. In normal conditions this will be the thread from which the Python interpreter was started. (Contributed by Andrew Svetlov in bpo-18882(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue18882  File: python.info, Node: traceback<3>, Next: types<3>, Prev: threading<4>, Up: Improved Modules<5> 1.5.4.56 traceback .................. A new *note traceback.clear_frames(): 8f1. function takes a traceback object and clears the local variables in all of the frames it references, reducing the amount of memory consumed. (Contributed by Andrew Kuchling in bpo-1565525(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1565525  File: python.info, Node: types<3>, Next: urllib<2>, Prev: traceback<3>, Up: Improved Modules<5> 1.5.4.57 types .............. A new *note DynamicClassAttribute(): 8f3. descriptor provides a way to define an attribute that acts normally when looked up through an instance object, but which is routed to the `class' ‘__getattr__’ when looked up through the class. This allows one to have properties active on a class, and have virtual attributes on the class with the same name (see ‘Enum’ for an example). (Contributed by Ethan Furman in bpo-19030(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19030  File: python.info, Node: urllib<2>, Next: unittest<4>, Prev: types<3>, Up: Improved Modules<5> 1.5.4.58 urllib ............... *note urllib.request: 120. now supports ‘data:’ URLs via the *note DataHandler: 8f5. class. (Contributed by Mathias Panzenböck in bpo-16423(1).) The http method that will be used by a *note Request: 8f6. class can now be specified by setting a *note method: 8f7. class attribute on the subclass. (Contributed by Jason R Coombs in bpo-18978(2).) *note Request: 8f6. objects are now reusable: if the *note full_url: 8f8. or *note data: 8f9. attributes are modified, all relevant internal properties are updated. This means, for example, that it is now possible to use the same *note Request: 8f6. object in more than one *note OpenerDirector.open(): 8fa. call with different `data' arguments, or to modify a *note Request: 8f6.’s ‘url’ rather than recomputing it from scratch. There is also a new *note remove_header(): 8fb. method that can be used to remove headers from a *note Request: 8f6. (Contributed by Alexey Kachayev in bpo-16464(3), Daniel Wozniak in bpo-17485(4), and Damien Brecht and Senthil Kumaran in bpo-17272(5).) *note HTTPError: 8fc. objects now have a *note headers: 8fd. attribute that provides access to the HTTP response headers associated with the error. (Contributed by Berker Peksag in bpo-15701(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16423 (2) https://bugs.python.org/issue18978 (3) https://bugs.python.org/issue16464 (4) https://bugs.python.org/issue17485 (5) https://bugs.python.org/issue17272 (6) https://bugs.python.org/issue15701  File: python.info, Node: unittest<4>, Next: venv<4>, Prev: urllib<2>, Up: Improved Modules<5> 1.5.4.59 unittest ................. The *note TestCase: 8ff. class has a new method, *note subTest(): 900, that produces a context manager whose *note with: 6e9. block becomes a “sub-test”. This context manager allows a test method to dynamically generate subtests by, say, calling the ‘subTest’ context manager inside a loop. A single test method can thereby produce an indefinite number of separately-identified and separately-counted tests, all of which will run even if one or more of them fail. For example: class NumbersTest(unittest.TestCase): def test_even(self): for i in range(6): with self.subTest(i=i): self.assertEqual(i % 2, 0) will result in six subtests, each identified in the unittest verbose output with a label consisting of the variable name ‘i’ and a particular value for that variable (‘i=0’, ‘i=1’, etc). See *note Distinguishing test iterations using subtests: 901. for the full version of this example. (Contributed by Antoine Pitrou in bpo-16997(1).) *note unittest.main(): 902. now accepts an iterable of test names for `defaultTest', where previously it only accepted a single test name as a string. (Contributed by Jyrki Pulliainen in bpo-15132(2).) If *note SkipTest: 903. is raised during test discovery (that is, at the module level in the test file), it is now reported as a skip instead of an error. (Contributed by Zach Ware in bpo-16935(3).) *note discover(): 904. now sorts the discovered files to provide consistent test ordering. (Contributed by Martin Melin and Jeff Ramnani in bpo-16709(4).) *note TestSuite: 6ce. now drops references to tests as soon as the test has been run, if the test is successful. On Python interpreters that do garbage collection, this allows the tests to be garbage collected if nothing else is holding a reference to the test. It is possible to override this behavior by creating a *note TestSuite: 6ce. subclass that defines a custom ‘_removeTestAtIndex’ method. (Contributed by Tom Wardill, Matt McClure, and Andrew Svetlov in bpo-11798(5).) A new test assertion context-manager, *note assertLogs(): 905, will ensure that a given block of code emits a log message using the *note logging: aa. module. By default the message can come from any logger and have a priority of ‘INFO’ or higher, but both the logger name and an alternative minimum logging level may be specified. The object returned by the context manager can be queried for the *note LogRecord: 906.s and/or formatted messages that were logged. (Contributed by Antoine Pitrou in bpo-18937(6).) Test discovery now works with namespace packages (Contributed by Claudiu Popa in bpo-17457(7).) *note unittest.mock: 11c. objects now inspect their specification signatures when matching calls, which means an argument can now be matched by either position or name, instead of only by position. (Contributed by Antoine Pitrou in bpo-17015(8).) ‘mock_open()’ objects now have ‘readline’ and ‘readlines’ methods. (Contributed by Toshio Kuratomi in bpo-17467(9).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16997 (2) https://bugs.python.org/issue15132 (3) https://bugs.python.org/issue16935 (4) https://bugs.python.org/issue16709 (5) https://bugs.python.org/issue11798 (6) https://bugs.python.org/issue18937 (7) https://bugs.python.org/issue17457 (8) https://bugs.python.org/issue17015 (9) https://bugs.python.org/issue17467  File: python.info, Node: venv<4>, Next: wave<2>, Prev: unittest<4>, Up: Improved Modules<5> 1.5.4.60 venv ............. *note venv: 125. now includes activation scripts for the ‘csh’ and ‘fish’ shells. (Contributed by Andrew Svetlov in bpo-15417(1).) *note EnvBuilder: 908. and the *note create(): 909. convenience function take a new keyword argument `with_pip', which defaults to ‘False’, that controls whether or not *note EnvBuilder: 908. ensures that ‘pip’ is installed in the virtual environment. (Contributed by Nick Coghlan in bpo-19552(2) as part of the PEP 453(3) implementation.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15417 (2) https://bugs.python.org/issue19552 (3) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: wave<2>, Next: weakref<2>, Prev: venv<4>, Up: Improved Modules<5> 1.5.4.61 wave ............. The ‘getparams()’ method now returns a namedtuple rather than a plain tuple. (Contributed by Claudiu Popa in bpo-17487(1).) *note wave.open(): 476. now supports the context management protocol. (Contributed by Claudiu Popa in bpo-17616(2).) *note wave: 127. can now *note write output to unseekable files: 90b. (Contributed by David Jones, Guilherme Polo, and Serhiy Storchaka in bpo-5202(3).) The *note writeframesraw(): 90c. and *note writeframes(): 90d. methods now accept any *note bytes-like object: 5e8. (Contributed by Serhiy Storchaka in bpo-8311(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17487 (2) https://bugs.python.org/issue17616 (3) https://bugs.python.org/issue5202 (4) https://bugs.python.org/issue8311  File: python.info, Node: weakref<2>, Next: xml etree<2>, Prev: wave<2>, Up: Improved Modules<5> 1.5.4.62 weakref ................ New *note WeakMethod: 90f. class simulates weak references to bound methods. (Contributed by Antoine Pitrou in bpo-14631(1).) New *note finalize: 29d. class makes it possible to register a callback to be invoked when an object is garbage collected, without needing to carefully manage the lifecycle of the weak reference itself. (Contributed by Richard Oudkerk in bpo-15528(2).) The callback, if any, associated with a *note ref: 910. is now exposed via the *note __callback__: 911. attribute. (Contributed by Mark Dickinson in bpo-17643(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14631 (2) https://bugs.python.org/issue15528 (3) https://bugs.python.org/issue17643  File: python.info, Node: xml etree<2>, Next: zipfile<4>, Prev: weakref<2>, Up: Improved Modules<5> 1.5.4.63 xml.etree .................. A new parser, *note XMLPullParser: 913, allows a non-blocking applications to parse XML documents. An example can be seen at *note Pull API for non-blocking parsing: 914. (Contributed by Antoine Pitrou in bpo-17741(1).) The *note xml.etree.ElementTree: 137. *note tostring(): 915. and *note tostringlist(): 916. functions, and the *note ElementTree: 917. *note write(): 918. method, now have a `short_empty_elements' *note keyword-only parameter: 2ac. providing control over whether elements with no content are written in abbreviated (‘’) or expanded (‘’) form. (Contributed by Ariel Poliak and Serhiy Storchaka in bpo-14377(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17741 (2) https://bugs.python.org/issue14377  File: python.info, Node: zipfile<4>, Prev: xml etree<2>, Up: Improved Modules<5> 1.5.4.64 zipfile ................ The *note writepy(): 91a. method of the *note PyZipFile: 91b. class has a new `filterfunc' option that can be used to control which directories and files are added to the archive. For example, this could be used to exclude test files from the archive. (Contributed by Christian Tismer in bpo-19274(1).) The `allowZip64' parameter to *note ZipFile: 41f. and ‘PyZipfile’ is now ‘True’ by default. (Contributed by William Mallard in bpo-17201(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue19274 (2) https://bugs.python.org/issue17201  File: python.info, Node: CPython Implementation Changes, Next: Deprecated<4>, Prev: Improved Modules<5>, Up: What’s New In Python 3 4 1.5.5 CPython Implementation Changes ------------------------------------ * Menu: * PEP 445; Customization of CPython Memory Allocators: PEP 445 Customization of CPython Memory Allocators. * PEP 442; Safe Object Finalization: PEP 442 Safe Object Finalization. * PEP 456; Secure and Interchangeable Hash Algorithm: PEP 456 Secure and Interchangeable Hash Algorithm. * PEP 436; Argument Clinic: PEP 436 Argument Clinic. * Other Build and C API Changes:: * Other Improvements: Other Improvements<2>. * Significant Optimizations::  File: python.info, Node: PEP 445 Customization of CPython Memory Allocators, Next: PEP 442 Safe Object Finalization, Up: CPython Implementation Changes 1.5.5.1 PEP 445: Customization of CPython Memory Allocators ........................................................... PEP 445(1) adds new C level interfaces to customize memory allocation in the CPython interpreter. See also ........ PEP 445(2) – Add new APIs to customize Python memory allocators PEP written and implemented by Victor Stinner. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0445 (2) https://www.python.org/dev/peps/pep-0445  File: python.info, Node: PEP 442 Safe Object Finalization, Next: PEP 456 Secure and Interchangeable Hash Algorithm, Prev: PEP 445 Customization of CPython Memory Allocators, Up: CPython Implementation Changes 1.5.5.2 PEP 442: Safe Object Finalization ......................................... PEP 442(1) removes the current limitations and quirks of object finalization in CPython. With it, objects with *note __del__(): 91f. methods, as well as generators with *note finally: 182. clauses, can be finalized when they are part of a reference cycle. As part of this change, module globals are no longer forcibly set to *note None: 157. during interpreter shutdown in most cases, instead relying on the normal operation of the cyclic garbage collector. This avoids a whole class of interpreter-shutdown-time errors, usually involving ‘__del__’ methods, that have plagued Python since the cyclic GC was first introduced. See also ........ PEP 442(2) – Safe object finalization PEP written and implemented by Antoine Pitrou. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0442 (2) https://www.python.org/dev/peps/pep-0442  File: python.info, Node: PEP 456 Secure and Interchangeable Hash Algorithm, Next: PEP 436 Argument Clinic, Prev: PEP 442 Safe Object Finalization, Up: CPython Implementation Changes 1.5.5.3 PEP 456: Secure and Interchangeable Hash Algorithm .......................................................... PEP 456(1) follows up on earlier security fix work done on Python’s hash algorithm to address certain DOS attacks to which public facing APIs backed by dictionary lookups may be subject. (See bpo-14621(2) for the start of the current round of improvements.) The PEP unifies CPython’s hash code to make it easier for a packager to substitute a different hash algorithm, and switches Python’s default implementation to a SipHash implementation on platforms that have a 64 bit data type. Any performance differences in comparison with the older FNV algorithm are trivial. The PEP adds additional fields to the *note sys.hash_info: 921. named tuple to describe the hash algorithm in use by the currently executing binary. Otherwise, the PEP does not alter any existing CPython APIs. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0456 (2) https://bugs.python.org/issue14621  File: python.info, Node: PEP 436 Argument Clinic, Next: Other Build and C API Changes, Prev: PEP 456 Secure and Interchangeable Hash Algorithm, Up: CPython Implementation Changes 1.5.5.4 PEP 436: Argument Clinic ................................ “Argument Clinic” ( PEP 436(1)) is now part of the CPython build process and can be used to simplify the process of defining and maintaining accurate signatures for builtins and standard library extension modules implemented in C. Some standard library extension modules have been converted to use Argument Clinic in Python 3.4, and *note pydoc: d9. and *note inspect: a0. have been updated accordingly. It is expected that signature metadata for programmatic introspection will be added to additional callables implemented in C as part of Python 3.4 maintenance releases. Note: The Argument Clinic PEP is not fully up to date with the state of the implementation. This has been deemed acceptable by the release manager and core development team in this case, as Argument Clinic will not be made available as a public API for third party use in Python 3.4. See also ........ PEP 436(2) – The Argument Clinic DSL PEP written and implemented by Larry Hastings. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0436 (2) https://www.python.org/dev/peps/pep-0436  File: python.info, Node: Other Build and C API Changes, Next: Other Improvements<2>, Prev: PEP 436 Argument Clinic, Up: CPython Implementation Changes 1.5.5.5 Other Build and C API Changes ..................................... * The new *note PyType_GetSlot(): 924. function has been added to the stable ABI, allowing retrieval of function pointers from named type slots when using the limited API. (Contributed by Martin von Löwis in bpo-17162(1).) * The new *note Py_SetStandardStreamEncoding(): 925. pre-initialization API allows applications embedding the CPython interpreter to reliably force a particular encoding and error handler for the standard streams. (Contributed by Bastien Montagne and Nick Coghlan in bpo-16129(2).) * Most Python C APIs that don’t mutate string arguments are now correctly marked as accepting ‘const char *’ rather than ‘char *’. (Contributed by Serhiy Storchaka in bpo-1772673(3).) * A new shell version of ‘python-config’ can be used even when a python interpreter is not available (for example, in cross compilation scenarios). * *note PyUnicode_FromFormat(): 7cb. now supports width and precision specifications for ‘%s’, ‘%A’, ‘%U’, ‘%V’, ‘%S’, and ‘%R’. (Contributed by Ysj Ray and Victor Stinner in bpo-7330(4).) * New function *note PyStructSequence_InitType2(): 926. supplements the existing *note PyStructSequence_InitType(): 927. function. The difference is that it returns ‘0’ on success and ‘-1’ on failure. * The CPython source can now be compiled using the address sanity checking features of recent versions of GCC and clang: the false alarms in the small object allocator have been silenced. (Contributed by Dhiru Kholia in bpo-18596(5).) * The Windows build now uses Address Space Layout Randomization(6) and Data Execution Prevention(7). (Contributed by Christian Heimes in bpo-16632(8).) * New function *note PyObject_LengthHint(): 928. is the C API equivalent of *note operator.length_hint(): 87d. (Contributed by Armin Ronacher in bpo-16148(9).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue17162 (2) https://bugs.python.org/issue16129 (3) https://bugs.python.org/issue1772673 (4) https://bugs.python.org/issue7330 (5) https://bugs.python.org/issue18596 (6) https://en.wikipedia.org/wiki/Address_space_layout_randomization (7) https://en.wikipedia.org/wiki/Data_Execution_Prevention (8) https://bugs.python.org/issue16632 (9) https://bugs.python.org/issue16148  File: python.info, Node: Other Improvements<2>, Next: Significant Optimizations, Prev: Other Build and C API Changes, Up: CPython Implementation Changes 1.5.5.6 Other Improvements .......................... * The *note python: 92b. command has a new *note option: 92c, ‘-I’, which causes it to run in “isolated mode”, which means that *note sys.path: 488. contains neither the script’s directory nor the user’s ‘site-packages’ directory, and all ‘PYTHON*’ environment variables are ignored (it implies both ‘-s’ and ‘-E’). Other restrictions may also be applied in the future, with the goal being to isolate the execution of a script from the user’s environment. This is appropriate, for example, when Python is used to run a system script. On most POSIX systems it can and should be used in the ‘#!’ line of system scripts. (Contributed by Christian Heimes in bpo-16499(1).) * Tab-completion is now enabled by default in the interactive interpreter on systems that support *note readline: de. History is also enabled by default, and is written to (and read from) the file ‘~/.python-history’. (Contributed by Antoine Pitrou and Éric Araujo in bpo-5845(2).) * Invoking the Python interpreter with ‘--version’ now outputs the version to standard output instead of standard error (bpo-18338(3)). Similar changes were made to *note argparse: 6. (bpo-18920(4)) and other modules that have script-like invocation capabilities (bpo-18922(5)). * The CPython Windows installer now adds ‘.py’ to the ‘PATHEXT’ variable when extensions are registered, allowing users to run a python script at the windows command prompt by just typing its name without the ‘.py’ extension. (Contributed by Paul Moore in bpo-18569(6).) * A new ‘make’ target coverage-report(7) will build python, run the test suite, and generate an HTML coverage report for the C codebase using ‘gcov’ and lcov(8). * The ‘-R’ option to the *note python regression test suite: 92d. now also checks for memory allocation leaks, using *note sys.getallocatedblocks(): 8e2. (Contributed by Antoine Pitrou in bpo-13390(9).) * ‘python -m’ now works with namespace packages. * The *note stat: f4. module is now implemented in C, which means it gets the values for its constants from the C header files, instead of having the values hard-coded in the python module as was previously the case. * Loading multiple python modules from a single OS module (‘.so’, ‘.dll’) now works correctly (previously it silently returned the first python module in the file). (Contributed by Václav Šmilauer in bpo-16421(10).) * A new opcode, *note LOAD_CLASSDEREF: 92e, has been added to fix a bug in the loading of free variables in class bodies that could be triggered by certain uses of *note __prepare__: 4fd. (Contributed by Benjamin Peterson in bpo-17853(11).) * A number of MemoryError-related crashes were identified and fixed by Victor Stinner using his PEP 445(12)-based ‘pyfailmalloc’ tool (bpo-18408(13), bpo-18520(14)). * The ‘pyvenv’ command now accepts a ‘--copies’ option to use copies rather than symlinks even on systems where symlinks are the default. (Contributed by Vinay Sajip in bpo-18807(15).) * The ‘pyvenv’ command also accepts a ‘--without-pip’ option to suppress the otherwise-automatic bootstrapping of pip into the virtual environment. (Contributed by Nick Coghlan in bpo-19552(16) as part of the PEP 453(17) implementation.) * The encoding name is now optional in the value set for the *note PYTHONIOENCODING: 92f. environment variable. This makes it possible to set just the error handler, without changing the default encoding. (Contributed by Serhiy Storchaka in bpo-18818(18).) * The *note bz2: 14, *note lzma: ad, and *note gzip: 8c. module ‘open’ functions now support ‘x’ (exclusive creation) mode. (Contributed by Tim Heaney and Vajrasky Kok in bpo-19201(19), bpo-19222(20), and bpo-19223(21).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue16499 (2) https://bugs.python.org/issue5845 (3) https://bugs.python.org/issue18338 (4) https://bugs.python.org/issue18920 (5) https://bugs.python.org/issue18922 (6) https://bugs.python.org/issue18569 (7) https://devguide.python.org/coverage/#measuring-coverage-of-c-code-with-gcov-and-lcov (8) http://ltp.sourceforge.net/coverage/lcov.php (9) https://bugs.python.org/issue13390 (10) https://bugs.python.org/issue16421 (11) https://bugs.python.org/issue17853 (12) https://www.python.org/dev/peps/pep-0445 (13) https://bugs.python.org/issue18408 (14) https://bugs.python.org/issue18520 (15) https://bugs.python.org/issue18807 (16) https://bugs.python.org/issue19552 (17) https://www.python.org/dev/peps/pep-0453 (18) https://bugs.python.org/issue18818 (19) https://bugs.python.org/issue19201 (20) https://bugs.python.org/issue19222 (21) https://bugs.python.org/issue19223  File: python.info, Node: Significant Optimizations, Prev: Other Improvements<2>, Up: CPython Implementation Changes 1.5.5.7 Significant Optimizations ................................. * The UTF-32 decoder is now 3x to 4x faster. (Contributed by Serhiy Storchaka in bpo-14625(1).) * The cost of hash collisions for sets is now reduced. Each hash table probe now checks a series of consecutive, adjacent key/hash pairs before continuing to make random probes through the hash table. This exploits cache locality to make collision resolution less expensive. The collision resolution scheme can be described as a hybrid of linear probing and open addressing. The number of additional linear probes defaults to nine. This can be changed at compile-time by defining LINEAR_PROBES to be any value. Set LINEAR_PROBES=0 to turn-off linear probing entirely. (Contributed by Raymond Hettinger in bpo-18771(2).) * The interpreter starts about 30% faster. A couple of measures lead to the speedup. The interpreter loads fewer modules on startup, e.g. the *note re: dd, *note collections: 1e. and *note locale: a9. modules and their dependencies are no longer imported by default. The marshal module has been improved to load compiled Python code faster. (Contributed by Antoine Pitrou, Christian Heimes and Victor Stinner in bpo-19219(3), bpo-19218(4), bpo-19209(5), bpo-19205(6) and bpo-9548(7).) * *note bz2.BZ2File: 931. is now as fast or faster than the Python2 version for most cases. *note lzma.LZMAFile: 932. has also been optimized. (Contributed by Serhiy Storchaka and Nadeem Vawda in bpo-16034(8).) * *note random.getrandbits(): 933. is 20%-40% faster for small integers (the most common use case). (Contributed by Serhiy Storchaka in bpo-16674(9).) * By taking advantage of the new storage format for strings, pickling of strings is now significantly faster. (Contributed by Victor Stinner and Antoine Pitrou in bpo-15596(10).) * A performance issue in ‘io.FileIO.readall()’ has been solved. This particularly affects Windows, and significantly speeds up the case of piping significant amounts of data through *note subprocess: f9. (Contributed by Richard Oudkerk in bpo-15758(11).) * *note html.escape(): 934. is now 10x faster. (Contributed by Matt Bryant in bpo-18020(12).) * On Windows, the native ‘VirtualAlloc’ is now used instead of the CRT ‘malloc’ in ‘obmalloc’. Artificial benchmarks show about a 3% memory savings. * *note os.urandom(): 4d1. now uses a lazily-opened persistent file descriptor so as to avoid using many file descriptors when run in parallel from multiple threads. (Contributed by Antoine Pitrou in bpo-18756(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14625 (2) https://bugs.python.org/issue18771 (3) https://bugs.python.org/issue19219 (4) https://bugs.python.org/issue19218 (5) https://bugs.python.org/issue19209 (6) https://bugs.python.org/issue19205 (7) https://bugs.python.org/issue9548 (8) https://bugs.python.org/issue16034 (9) https://bugs.python.org/issue16674 (10) https://bugs.python.org/issue15596 (11) https://bugs.python.org/issue15758 (12) https://bugs.python.org/issue18020 (13) https://bugs.python.org/issue18756  File: python.info, Node: Deprecated<4>, Next: Removed<3>, Prev: CPython Implementation Changes, Up: What’s New In Python 3 4 1.5.6 Deprecated ---------------- This section covers various APIs and other features that have been deprecated in Python 3.4, and will be removed in Python 3.5 or later. In most (but not all) cases, using the deprecated APIs will produce a *note DeprecationWarning: 278. when the interpreter is run with deprecation warnings enabled (for example, by using ‘-Wd’). * Menu: * Deprecations in the Python API:: * Deprecated Features::  File: python.info, Node: Deprecations in the Python API, Next: Deprecated Features, Up: Deprecated<4> 1.5.6.1 Deprecations in the Python API ...................................... * As mentioned in *note PEP 451; A ModuleSpec Type for the Import System: 7d8, a number of *note importlib: 9b. methods and functions are deprecated: *note importlib.find_loader(): 937. is replaced by *note importlib.util.find_spec(): 938.; *note importlib.machinery.PathFinder.find_module(): 939. is replaced by *note importlib.machinery.PathFinder.find_spec(): 93a.; *note importlib.abc.MetaPathFinder.find_module(): 462. is replaced by *note importlib.abc.MetaPathFinder.find_spec(): 463.; *note importlib.abc.PathEntryFinder.find_loader(): 464. and *note find_module(): 93b. are replaced by *note importlib.abc.PathEntryFinder.find_spec(): 465.; all of the ‘xxxLoader’ ABC ‘load_module’ methods (*note importlib.abc.Loader.load_module(): 5e3, *note importlib.abc.InspectLoader.load_module(): 93c, *note importlib.abc.FileLoader.load_module(): 93d, *note importlib.abc.SourceLoader.load_module(): 93e.) should no longer be implemented, instead loaders should implement an ‘exec_module’ method (*note importlib.abc.Loader.exec_module(): 5e4, *note importlib.abc.InspectLoader.exec_module(): 93f. *note importlib.abc.SourceLoader.exec_module(): 940.) and let the import system take care of the rest; and *note importlib.abc.Loader.module_repr(): 941, *note importlib.util.module_for_loader(): 942, *note importlib.util.set_loader(): 943, and *note importlib.util.set_package(): 944. are no longer needed because their functions are now handled automatically by the import system. * The *note imp: 9a. module is pending deprecation. To keep compatibility with Python 2/3 code bases, the module’s removal is currently not scheduled. * The *note formatter: 82. module is pending deprecation and is slated for removal in Python 3.6. * ‘MD5’ as the default `digestmod' for the *note hmac.new(): 854. function is deprecated. Python 3.6 will require an explicit digest name or constructor as `digestmod' argument. * The internal ‘Netrc’ class in the *note ftplib: 84. module has been documented as deprecated in its docstring for quite some time. It now emits a *note DeprecationWarning: 278. and will be removed completely in Python 3.5. * The undocumented `endtime' argument to *note subprocess.Popen.wait(): 592. should not have been exposed and is hopefully not in use; it is deprecated and will mostly likely be removed in Python 3.5. * The `strict' argument of *note HTMLParser: 7bf. is deprecated. * The *note plistlib: cf. *note readPlist(): 47f, *note writePlist(): 945, *note readPlistFromBytes(): 480, and *note writePlistToBytes(): 946. functions are deprecated in favor of the corresponding new functions *note load(): 88b, *note dump(): 88c, *note loads(): 88d, and *note dumps(): 88e. *note Data(): 947. is deprecated in favor of just using the *note bytes: 331. constructor. * The *note sysconfig: fe. key ‘SO’ is deprecated, it has been replaced by ‘EXT_SUFFIX’. * The ‘U’ mode accepted by various ‘open’ functions is deprecated. In Python3 it does not do anything useful, and should be replaced by appropriate uses of *note io.TextIOWrapper: 5f3. (if needed) and its `newline' argument. * The `parser' argument of *note xml.etree.ElementTree.iterparse(): 948. has been deprecated, as has the `html' argument of *note XMLParser(): 252. To prepare for the removal of the latter, all arguments to ‘XMLParser’ should be passed by keyword.  File: python.info, Node: Deprecated Features, Prev: Deprecations in the Python API, Up: Deprecated<4> 1.5.6.2 Deprecated Features ........................... * Running *note IDLE: 94a. with the ‘-n’ flag (no subprocess) is deprecated. However, the feature will not be removed until bpo-18823(1) is resolved. * The site module adding a “site-python” directory to sys.path, if it exists, is deprecated (bpo-19375(2)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue18823 (2) https://bugs.python.org/issue19375  File: python.info, Node: Removed<3>, Next: Porting to Python 3 4, Prev: Deprecated<4>, Up: What’s New In Python 3 4 1.5.7 Removed ------------- * Menu: * Operating Systems No Longer Supported:: * API and Feature Removals: API and Feature Removals<5>. * Code Cleanups::  File: python.info, Node: Operating Systems No Longer Supported, Next: API and Feature Removals<5>, Up: Removed<3> 1.5.7.1 Operating Systems No Longer Supported ............................................. Support for the following operating systems has been removed from the source and build tools: * OS/2 (bpo-16135(1)). * Windows 2000 (changeset e52df05b496a). * Windows systems where ‘COMSPEC’ points to ‘command.com’ (bpo-14470(2)). * VMS (bpo-16136(3)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue16135 (2) https://bugs.python.org/issue14470 (3) https://bugs.python.org/issue16136  File: python.info, Node: API and Feature Removals<5>, Next: Code Cleanups, Prev: Operating Systems No Longer Supported, Up: Removed<3> 1.5.7.2 API and Feature Removals ................................ The following obsolete and previously deprecated APIs and features have been removed: * The unmaintained ‘Misc/TextMate’ and ‘Misc/vim’ directories have been removed (see the devguide(1) for suggestions on what to use instead). * The ‘SO’ makefile macro is removed (it was replaced by the ‘SHLIB_SUFFIX’ and ‘EXT_SUFFIX’ macros) (bpo-16754(2)). * The ‘PyThreadState.tick_counter’ field has been removed; its value has been meaningless since Python 3.2, when the “new GIL” was introduced (bpo-19199(3)). * ‘PyLoader’ and ‘PyPycLoader’ have been removed from *note importlib: 9b. (Contributed by Taras Lyapun in bpo-15641(4).) * The `strict' argument to *note HTTPConnection: 392. and *note HTTPSConnection: 393. has been removed. HTTP 0.9-style “Simple Responses” are no longer supported. * The deprecated *note urllib.request.Request: 8f6. getter and setter methods ‘add_data’, ‘has_data’, ‘get_data’, ‘get_type’, ‘get_host’, ‘get_selector’, ‘set_proxy’, ‘get_origin_req_host’, and ‘is_unverifiable’ have been removed (use direct attribute access instead). * Support for loading the deprecated ‘TYPE_INT64’ has been removed from *note marshal: b0. (Contributed by Dan Riti in bpo-15480(5).) * *note inspect.Signature: 6f3.: positional-only parameters are now required to have a valid name. * *note object.__format__(): 94e. no longer accepts non-empty format strings, it now raises a *note TypeError: 192. instead. Using a non-empty string has been deprecated since Python 3.2. This change has been made to prevent a situation where previously working (but incorrect) code would start failing if an object gained a __format__ method, which means that your code may now raise a *note TypeError: 192. if you are using an ‘'s'’ format code with objects that do not have a __format__ method that handles it. See bpo-7994(6) for background. * ‘difflib.SequenceMatcher.isbjunk()’ and ‘difflib.SequenceMatcher.isbpopular()’ were deprecated in 3.2, and have now been removed: use ‘x in sm.bjunk’ and ‘x in sm.bpopular’, where `sm' is a *note SequenceMatcher: 94f. object (bpo-13248(7)). ---------- Footnotes ---------- (1) https://devguide.python.org (2) https://bugs.python.org/issue16754 (3) https://bugs.python.org/issue19199 (4) https://bugs.python.org/issue15641 (5) https://bugs.python.org/issue15480 (6) https://bugs.python.org/issue7994 (7) https://bugs.python.org/issue13248  File: python.info, Node: Code Cleanups, Prev: API and Feature Removals<5>, Up: Removed<3> 1.5.7.3 Code Cleanups ..................... * The unused and undocumented internal ‘Scanner’ class has been removed from the *note pydoc: d9. module. * The private and effectively unused ‘_gestalt’ module has been removed, along with the private *note platform: ce. functions ‘_mac_ver_lookup’, ‘_mac_ver_gstalt’, and ‘_bcd2str’, which would only have ever been called on badly broken OSX systems (see bpo-18393(1)). * The hardcoded copies of certain *note stat: f4. constants that were included in the *note tarfile: 101. module namespace have been removed. ---------- Footnotes ---------- (1) https://bugs.python.org/issue18393  File: python.info, Node: Porting to Python 3 4, Next: Changed in 3 4 3, Prev: Removed<3>, Up: What’s New In Python 3 4 1.5.8 Porting to Python 3.4 --------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Changes in ‘python’ Command Behavior: Changes in ‘python’ Command Behavior<2>. * Changes in the Python API: Changes in the Python API<5>. * Changes in the C API: Changes in the C API<5>.  File: python.info, Node: Changes in ‘python’ Command Behavior<2>, Next: Changes in the Python API<5>, Up: Porting to Python 3 4 1.5.8.1 Changes in ‘python’ Command Behavior ............................................ * In a posix shell, setting the ‘PATH’ environment variable to an empty value is equivalent to not setting it at all. However, setting *note PYTHONPATH: 953. to an empty value was `not' equivalent to not setting it at all: setting *note PYTHONPATH: 953. to an empty value was equivalent to setting it to ‘.’, which leads to confusion when reasoning by analogy to how ‘PATH’ works. The behavior now conforms to the posix convention for ‘PATH’. * The [X refs, Y blocks] output of a debug (‘--with-pydebug’) build of the CPython interpreter is now off by default. It can be re-enabled using the ‘-X showrefcount’ option. (Contributed by Ezio Melotti in bpo-17323(1).) * The python command and most stdlib scripts (as well as *note argparse: 6.) now output ‘--version’ information to ‘stdout’ instead of ‘stderr’ (for issue list see *note Other Improvements: 92a. above). ---------- Footnotes ---------- (1) https://bugs.python.org/issue17323  File: python.info, Node: Changes in the Python API<5>, Next: Changes in the C API<5>, Prev: Changes in ‘python’ Command Behavior<2>, Up: Porting to Python 3 4 1.5.8.2 Changes in the Python API ................................. * The ABCs defined in *note importlib.abc: 9c. now either raise the appropriate exception or return a default value instead of raising *note NotImplementedError: 60e. blindly. This will only affect code calling *note super(): 4e2. and falling through all the way to the ABCs. For compatibility, catch both *note NotImplementedError: 60e. or the appropriate exception as needed. * The module type now initializes the *note __package__: 955. and *note __loader__: 956. attributes to ‘None’ by default. To determine if these attributes were set in a backwards-compatible fashion, use e.g. ‘getattr(module, '__loader__', None) is not None’. (bpo-17115(1).) * *note importlib.util.module_for_loader(): 942. now sets ‘__loader__’ and ‘__package__’ unconditionally to properly support reloading. If this is not desired then you will need to set these attributes manually. You can use ‘importlib.util.module_to_load()’ for module management. * Import now resets relevant attributes (e.g. ‘__name__’, ‘__loader__’, ‘__package__’, ‘__file__’, ‘__cached__’) unconditionally when reloading. Note that this restores a pre-3.3 behavior in that it means a module is re-found when re-loaded (bpo-19413(2)). * Frozen packages no longer set ‘__path__’ to a list containing the package name, they now set it to an empty list. The previous behavior could cause the import system to do the wrong thing on submodule imports if there was also a directory with the same name as the frozen package. The correct way to determine if a module is a package or not is to use ‘hasattr(module, '__path__')’ (bpo-18065(3)). * Frozen modules no longer define a ‘__file__’ attribute. It’s semantically incorrect for frozen modules to set the attribute as they are not loaded from any explicit location. If you must know that a module comes from frozen code then you can see if the module’s ‘__spec__.location’ is set to ‘'frozen'’, check if the loader is a subclass of *note importlib.machinery.FrozenImporter: 957, or if Python 2 compatibility is necessary you can use ‘imp.is_frozen()’. * *note py_compile.compile(): 215. now raises *note FileExistsError: 958. if the file path it would write to is a symlink or a non-regular file. This is to act as a warning that import will overwrite those files with a regular file regardless of what type of file path they were originally. * *note importlib.abc.SourceLoader.get_source(): 959. no longer raises *note ImportError: 334. when the source code being loaded triggers a *note SyntaxError: 458. or *note UnicodeDecodeError: 1fd. As *note ImportError: 334. is meant to be raised only when source code cannot be found but it should, it was felt to be over-reaching/overloading of that meaning when the source code is found but improperly structured. If you were catching ImportError before and wish to continue to ignore syntax or decoding issues, catch all three exceptions now. * *note functools.update_wrapper(): 95a. and *note functools.wraps(): 86a. now correctly set the ‘__wrapped__’ attribute to the function being wrapped, even if that function also had its ‘__wrapped__’ attribute set. This means ‘__wrapped__’ attributes now correctly link a stack of decorated functions rather than every ‘__wrapped__’ attribute in the chain referring to the innermost function. Introspection libraries that assumed the previous behaviour was intentional can use *note inspect.unwrap(): 869. to access the first function in the chain that has no ‘__wrapped__’ attribute. * *note inspect.getfullargspec(): 55d. has been reimplemented on top of *note inspect.signature(): 55b. and hence handles a much wider variety of callable objects than it did in the past. It is expected that additional builtin and extension module callables will gain signature metadata over the course of the Python 3.4 series. Code that assumes that *note inspect.getfullargspec(): 55d. will fail on non-Python callables may need to be adjusted accordingly. * *note importlib.machinery.PathFinder: 95b. now passes on the current working directory to objects in *note sys.path_hooks: 95c. for the empty string. This results in *note sys.path_importer_cache: 49d. never containing ‘''’, thus iterating through *note sys.path_importer_cache: 49d. based on *note sys.path: 488. will not find all keys. A module’s ‘__file__’ when imported in the current working directory will also now have an absolute path, including when using ‘-m’ with the interpreter (except for ‘__main__.__file__’ when a script has been executed directly using a relative path) (Contributed by Brett Cannon in bpo-18416(4)). is specified on the command-line) (bpo-18416(5)). * The removal of the `strict' argument to *note HTTPConnection: 392. and *note HTTPSConnection: 393. changes the meaning of the remaining arguments if you are specifying them positionally rather than by keyword. If you’ve been paying attention to deprecation warnings your code should already be specifying any additional arguments via keywords. * Strings between ‘from __future__ import ...’ statements now `always' raise a *note SyntaxError: 458. Previously if there was no leading docstring, an interstitial string would sometimes be ignored. This brings CPython into compliance with the language spec; Jython and PyPy already were. (bpo-17434(6)). * *note ssl.SSLSocket.getpeercert(): 8d1. and *note ssl.SSLSocket.do_handshake(): 75a. now raise an *note OSError: 1d3. with ‘ENOTCONN’ when the ‘SSLSocket’ is not connected, instead of the previous behavior of raising an *note AttributeError: 39b. In addition, *note getpeercert(): 8d1. will raise a *note ValueError: 1fb. if the handshake has not yet been done. * *note base64.b32decode(): 95d. now raises a *note binascii.Error: 95e. when the input string contains non-b32-alphabet characters, instead of a *note TypeError: 192. This particular *note TypeError: 192. was missed when the other *note TypeError: 192.s were converted. (Contributed by Serhiy Storchaka in bpo-18011(7).) Note: this change was also inadvertently applied in Python 3.3.3. * The ‘file’ attribute is now automatically closed when the creating ‘cgi.FieldStorage’ instance is garbage collected. If you were pulling the file object out separately from the ‘cgi.FieldStorage’ instance and not keeping the instance alive, then you should either store the entire ‘cgi.FieldStorage’ instance or read the contents of the file before the ‘cgi.FieldStorage’ instance is garbage collected. * Calling ‘read’ or ‘write’ on a closed SSL socket now raises an informative *note ValueError: 1fb. rather than the previous more mysterious *note AttributeError: 39b. (bpo-9177(8)). * *note slice.indices(): 95f. no longer produces an *note OverflowError: 960. for huge values. As a consequence of this fix, *note slice.indices(): 95f. now raises a *note ValueError: 1fb. if given a negative length; previously it returned nonsense values (bpo-14794(9)). * The *note complex: 189. constructor, unlike the *note cmath: 19. functions, was incorrectly accepting *note float: 187. values if an object’s ‘__complex__’ special method returned one. This now raises a *note TypeError: 192. (bpo-16290(10).) * The *note int: 184. constructor in 3.2 and 3.3 erroneously accepts *note float: 187. values for the `base' parameter. It is unlikely anyone was doing this, but if so, it will now raise a *note TypeError: 192. (bpo-16772(11)). * Defaults for keyword-only arguments are now evaluated `after' defaults for regular keyword arguments, instead of before. Hopefully no one wrote any code that depends on the previous buggy behavior (bpo-16967(12)). * Stale thread states are now cleared after *note fork(): 961. This may cause some system resources to be released that previously were incorrectly kept perpetually alive (for example, database connections kept in thread-local storage). (bpo-17094(13).) * Parameter names in ‘__annotations__’ dicts are now mangled properly, similarly to ‘__kwdefaults__’. (Contributed by Yury Selivanov in bpo-20625(14).) * *note hashlib.hash.name: 852. now always returns the identifier in lower case. Previously some builtin hashes had uppercase names, but now that it is a formal public interface the naming has been made consistent (bpo-18532(15)). * Because *note unittest.TestSuite: 6ce. now drops references to tests after they are run, test harnesses that re-use a *note TestSuite: 6ce. to re-run a set of tests may fail. Test suites should not be re-used in this fashion since it means state is retained between test runs, breaking the test isolation that *note unittest: 11b. is designed to provide. However, if the lack of isolation is considered acceptable, the old behavior can be restored by creating a *note TestSuite: 6ce. subclass that defines a ‘_removeTestAtIndex’ method that does nothing (see *note TestSuite.__iter__(): 962.) (bpo-11798(16)). * *note unittest: 11b. now uses *note argparse: 6. for command line parsing. There are certain invalid command forms that used to work that are no longer allowed; in theory this should not cause backward compatibility issues since the disallowed command forms didn’t make any sense and are unlikely to be in use. * The *note re.split(): 3ca, *note re.findall(): 963, and *note re.sub(): 47b. functions, and the ‘group()’ and ‘groups()’ methods of ‘match’ objects now always return a `bytes' object when the string to be matched is a *note bytes-like object: 5e8. Previously the return type matched the input type, so if your code was depending on the return value being, say, a ‘bytearray’, you will need to change your code. * *note audioop: d. functions now raise an error immediately if passed string input, instead of failing randomly later on (bpo-16685(17)). * The new `convert_charrefs' argument to *note HTMLParser: 7bf. currently defaults to ‘False’ for backward compatibility, but will eventually be changed to default to ‘True’. It is recommended that you add this keyword, with the appropriate value, to any *note HTMLParser: 7bf. calls in your code (bpo-13633(18)). * Since the `digestmod' argument to the *note hmac.new(): 854. function will in the future have no default, all calls to *note hmac.new(): 854. should be changed to explicitly specify a `digestmod' (bpo-17276(19)). * Calling *note sysconfig.get_config_var(): 964. with the ‘SO’ key, or looking ‘SO’ up in the results of a call to *note sysconfig.get_config_vars(): 965. is deprecated. This key should be replaced by ‘EXT_SUFFIX’ or ‘SHLIB_SUFFIX’, depending on the context (bpo-19555(20)). * Any calls to ‘open’ functions that specify ‘U’ should be modified. ‘U’ is ineffective in Python3 and will eventually raise an error if used. Depending on the function, the equivalent of its old Python2 behavior can be achieved using either a `newline' argument, or if necessary by wrapping the stream in *note TextIOWrapper: 5f3. to use its `newline' argument (bpo-15204(21)). * If you use ‘pyvenv’ in a script and desire that pip `not' be installed, you must add ‘--without-pip’ to your command invocation. * The default behavior of *note json.dump(): 604. and *note json.dumps(): 605. when an indent is specified has changed: it no longer produces trailing spaces after the item separating commas at the ends of lines. This will matter only if you have tests that are doing white-space-sensitive comparisons of such output (bpo-16333(22)). * *note doctest: 67. now looks for doctests in extension module ‘__doc__’ strings, so if your doctest test discovery includes extension modules that have things that look like doctests in them you may see test failures you’ve never seen before when running your tests (bpo-3158(23)). * The *note collections.abc: 1f. module has been slightly refactored as part of the Python startup improvements. As a consequence of this, it is no longer the case that importing *note collections: 1e. automatically imports *note collections.abc: 1f. If your program depended on the (undocumented) implicit import, you will need to add an explicit ‘import collections.abc’ (bpo-20784(24)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue17115 (2) https://bugs.python.org/issue19413 (3) https://bugs.python.org/issue18065 (4) https://bugs.python.org/issue18416 (5) https://bugs.python.org/issue18416 (6) https://bugs.python.org/issue17434 (7) https://bugs.python.org/issue18011 (8) https://bugs.python.org/issue9177 (9) https://bugs.python.org/issue14794 (10) https://bugs.python.org/issue16290 (11) https://bugs.python.org/issue16772 (12) https://bugs.python.org/issue16967 (13) https://bugs.python.org/issue17094 (14) https://bugs.python.org/issue20625 (15) https://bugs.python.org/issue18532 (16) https://bugs.python.org/issue11798 (17) https://bugs.python.org/issue16685 (18) https://bugs.python.org/issue13633 (19) https://bugs.python.org/issue17276 (20) https://bugs.python.org/issue19555 (21) https://bugs.python.org/issue15204 (22) https://bugs.python.org/issue16333 (23) https://bugs.python.org/issue3158 (24) https://bugs.python.org/issue20784  File: python.info, Node: Changes in the C API<5>, Prev: Changes in the Python API<5>, Up: Porting to Python 3 4 1.5.8.3 Changes in the C API ............................ * *note PyEval_EvalFrameEx(): 967, *note PyObject_Repr(): 968, and *note PyObject_Str(): 969, along with some other internal C APIs, now include a debugging assertion that ensures they are not used in situations where they may silently discard a currently active exception. In cases where discarding the active exception is expected and desired (for example, because it has already been saved locally with *note PyErr_Fetch(): 96a. or is being deliberately replaced with a different exception), an explicit *note PyErr_Clear(): 96b. call will be needed to avoid triggering the assertion when invoking these operations (directly or indirectly) and running against a version of Python that is compiled with assertions enabled. * *note PyErr_SetImportError(): 5f8. now sets *note TypeError: 192. when its `msg' argument is not set. Previously only ‘NULL’ was returned with no exception set. * The result of the *note PyOS_ReadlineFunctionPointer: 96c. callback must now be a string allocated by *note PyMem_RawMalloc(): 96d. or *note PyMem_RawRealloc(): 96e, or ‘NULL’ if an error occurred, instead of a string allocated by *note PyMem_Malloc(): 505. or *note PyMem_Realloc(): 96f. (bpo-16742(1)) * *note PyThread_set_key_value(): 970. now always set the value. In Python 3.3, the function did nothing if the key already exists (if the current value is a non-‘NULL’ pointer). * The ‘f_tstate’ (thread state) field of the *note PyFrameObject: 971. structure has been removed to fix a bug: see bpo-14432(2) for the rationale. ---------- Footnotes ---------- (1) https://bugs.python.org/issue16742 (2) https://bugs.python.org/issue14432  File: python.info, Node: Changed in 3 4 3, Prev: Porting to Python 3 4, Up: What’s New In Python 3 4 1.5.9 Changed in 3.4.3 ---------------------- * Menu: * PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients.  File: python.info, Node: PEP 476 Enabling certificate verification by default for stdlib http clients, Up: Changed in 3 4 3 1.5.9.1 PEP 476: Enabling certificate verification by default for stdlib http clients ..................................................................................... *note http.client: 94. and modules which use it, such as *note urllib.request: 120. and *note xmlrpc.client: 13f, will now verify that the server presents a certificate which is signed by a CA in the platform trust store and whose hostname matches the hostname being requested by default, significantly improving security for many applications. For applications which require the old previous behavior, they can pass an alternate context: import urllib.request import ssl # This disables all verification context = ssl._create_unverified_context() # This allows using a specific certificate for the host, which doesn't need # to be in the trust store context = ssl.create_default_context(cafile="/path/to/file.crt") urllib.request.urlopen("https://invalid-cert", context=context)  File: python.info, Node: What’s New In Python 3 3, Next: What’s New In Python 3 2, Prev: What’s New In Python 3 4, Up: What’s New in Python 1.6 What’s New In Python 3.3 ============================ This article explains the new features in Python 3.3, compared to 3.2. Python 3.3 was released on September 29, 2012. For full details, see the changelog(1). See also ........ PEP 398(2) - Python 3.3 Release Schedule * Menu: * Summary – Release highlights: Summary – Release highlights<4>. * PEP 405; Virtual Environments: PEP 405 Virtual Environments. * PEP 420; Implicit Namespace Packages: PEP 420 Implicit Namespace Packages. * PEP 3118; New memoryview implementation and buffer protocol documentation: PEP 3118 New memoryview implementation and buffer protocol documentation. * PEP 393; Flexible String Representation: PEP 393 Flexible String Representation. * PEP 397; Python Launcher for Windows: PEP 397 Python Launcher for Windows. * PEP 3151; Reworking the OS and IO exception hierarchy: PEP 3151 Reworking the OS and IO exception hierarchy. * PEP 380; Syntax for Delegating to a Subgenerator: PEP 380 Syntax for Delegating to a Subgenerator. * PEP 409; Suppressing exception context: PEP 409 Suppressing exception context. * PEP 414; Explicit Unicode literals: PEP 414 Explicit Unicode literals. * PEP 3155; Qualified name for classes and functions: PEP 3155 Qualified name for classes and functions. * PEP 412; Key-Sharing Dictionary: PEP 412 Key-Sharing Dictionary. * PEP 362; Function Signature Object: PEP 362 Function Signature Object. * PEP 421; Adding sys.implementation: PEP 421 Adding sys implementation. * Using importlib as the Implementation of Import:: * Other Language Changes: Other Language Changes<6>. * A Finer-Grained Import Lock:: * Builtin functions and types:: * New Modules: New Modules<6>. * Improved Modules: Improved Modules<6>. * Optimizations: Optimizations<5>. * Build and C API Changes: Build and C API Changes<4>. * Deprecated: Deprecated<5>. * Porting to Python 3.3: Porting to Python 3 3. ---------- Footnotes ---------- (1) https://docs.python.org/3.3/whatsnew/changelog.html (2) https://www.python.org/dev/peps/pep-0398  File: python.info, Node: Summary – Release highlights<4>, Next: PEP 405 Virtual Environments, Up: What’s New In Python 3 3 1.6.1 Summary – Release highlights ---------------------------------- New syntax features: * New ‘yield from’ expression for *note generator delegation: 978. * The ‘u'unicode'’ syntax is accepted again for *note str: 330. objects. New library modules: * *note faulthandler: 7d. (helps debugging low-level crashes) * *note ipaddress: a2. (high-level objects representing IP addresses and masks) * *note lzma: ad. (compress data using the XZ / LZMA algorithm) * *note unittest.mock: 11c. (replace parts of your system under test with mock objects) * *note venv: 125. (Python *note virtual environments: 979, as in the popular ‘virtualenv’ package) New built-in features: * Reworked *note I/O exception hierarchy: 97a. Implementation improvements: * Rewritten *note import machinery: 97b. based on *note importlib: 9b. * More compact *note unicode strings: 97c. * More compact *note attribute dictionaries: 97d. Significantly Improved Library Modules: * C Accelerator for the *note decimal: 97e. module. * Better unicode handling in the *note email: 97f. module (*note provisional: 980.). Security improvements: * Hash randomization is switched on by default. Please read on for a comprehensive list of user-facing changes.  File: python.info, Node: PEP 405 Virtual Environments, Next: PEP 420 Implicit Namespace Packages, Prev: Summary – Release highlights<4>, Up: What’s New In Python 3 3 1.6.2 PEP 405: Virtual Environments ----------------------------------- Virtual environments help create separate Python setups while sharing a system-wide base install, for ease of maintenance. Virtual environments have their own set of private site packages (i.e. locally-installed libraries), and are optionally segregated from the system-wide site packages. Their concept and implementation are inspired by the popular ‘virtualenv’ third-party package, but benefit from tighter integration with the interpreter core. This PEP adds the *note venv: 125. module for programmatic access, and the ‘pyvenv’ script for command-line access and administration. The Python interpreter checks for a ‘pyvenv.cfg’, file whose existence signals the base of a virtual environment’s directory tree. See also ........ PEP 405(1) - Python Virtual Environments PEP written by Carl Meyer; implementation by Carl Meyer and Vinay Sajip ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0405  File: python.info, Node: PEP 420 Implicit Namespace Packages, Next: PEP 3118 New memoryview implementation and buffer protocol documentation, Prev: PEP 405 Virtual Environments, Up: What’s New In Python 3 3 1.6.3 PEP 420: Implicit Namespace Packages ------------------------------------------ Native support for package directories that don’t require ‘__init__.py’ marker files and can automatically span multiple path segments (inspired by various third party approaches to namespace packages, as described in PEP 420(1)) See also ........ PEP 420(2) - Implicit Namespace Packages PEP written by Eric V. Smith; implementation by Eric V. Smith and Barry Warsaw ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0420 (2) https://www.python.org/dev/peps/pep-0420  File: python.info, Node: PEP 3118 New memoryview implementation and buffer protocol documentation, Next: PEP 393 Flexible String Representation, Prev: PEP 420 Implicit Namespace Packages, Up: What’s New In Python 3 3 1.6.4 PEP 3118: New memoryview implementation and buffer protocol documentation ------------------------------------------------------------------------------- The implementation of PEP 3118(1) has been significantly improved. The new memoryview implementation comprehensively fixes all ownership and lifetime issues of dynamically allocated fields in the Py_buffer struct that led to multiple crash reports. Additionally, several functions that crashed or returned incorrect results for non-contiguous or multi-dimensional input have been fixed. The memoryview object now has a PEP-3118 compliant getbufferproc() that checks the consumer’s request type. Many new features have been added, most of them work in full generality for non-contiguous arrays and arrays with suboffsets. The documentation has been updated, clearly spelling out responsibilities for both exporters and consumers. Buffer request flags are grouped into basic and compound flags. The memory layout of non-contiguous and multi-dimensional NumPy-style arrays is explained. * Menu: * Features:: * API changes:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3118  File: python.info, Node: Features, Next: API changes, Up: PEP 3118 New memoryview implementation and buffer protocol documentation 1.6.4.1 Features ................ * All native single character format specifiers in struct module syntax (optionally prefixed with ‘@’) are now supported. * With some restrictions, the cast() method allows changing of format and shape of C-contiguous arrays. * Multi-dimensional list representations are supported for any array type. * Multi-dimensional comparisons are supported for any array type. * One-dimensional memoryviews of hashable (read-only) types with formats B, b or c are now hashable. (Contributed by Antoine Pitrou in bpo-13411(1).) * Arbitrary slicing of any 1-D arrays type is supported. For example, it is now possible to reverse a memoryview in O(1) by using a negative step. ---------- Footnotes ---------- (1) https://bugs.python.org/issue13411  File: python.info, Node: API changes, Prev: Features, Up: PEP 3118 New memoryview implementation and buffer protocol documentation 1.6.4.2 API changes ................... * The maximum number of dimensions is officially limited to 64. * The representation of empty shape, strides and suboffsets is now an empty tuple instead of ‘None’. * Accessing a memoryview element with format ‘B’ (unsigned bytes) now returns an integer (in accordance with the struct module syntax). For returning a bytes object the view must be cast to ‘c’ first. * memoryview comparisons now use the logical structure of the operands and compare all array elements by value. All format strings in struct module syntax are supported. Views with unrecognised format strings are still permitted, but will always compare as unequal, regardless of view contents. * For further changes see *note Build and C API Changes: 987. and *note Porting C code: 988. (Contributed by Stefan Krah in bpo-10181(1).) See also ........ PEP 3118(2) - Revising the Buffer Protocol ---------- Footnotes ---------- (1) https://bugs.python.org/issue10181 (2) https://www.python.org/dev/peps/pep-3118  File: python.info, Node: PEP 393 Flexible String Representation, Next: PEP 397 Python Launcher for Windows, Prev: PEP 3118 New memoryview implementation and buffer protocol documentation, Up: What’s New In Python 3 3 1.6.5 PEP 393: Flexible String Representation --------------------------------------------- The Unicode string type is changed to support multiple internal representations, depending on the character with the largest Unicode ordinal (1, 2, or 4 bytes) in the represented string. This allows a space-efficient representation in common cases, but gives access to full UCS-4 on all systems. For compatibility with existing APIs, several representations may exist in parallel; over time, this compatibility should be phased out. On the Python side, there should be no downside to this change. On the C API side, PEP 393(1) is fully backward compatible. The legacy API should remain available at least five years. Applications using the legacy API will not fully benefit of the memory reduction, or - worse - may use a bit more memory, because Python may have to maintain two versions of each string (in the legacy format and in the new efficient storage). * Menu: * Functionality:: * Performance and resource usage:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393  File: python.info, Node: Functionality, Next: Performance and resource usage, Up: PEP 393 Flexible String Representation 1.6.5.1 Functionality ..................... Changes introduced by PEP 393(1) are the following: * Python now always supports the full range of Unicode code points, including non-BMP ones (i.e. from ‘U+0000’ to ‘U+10FFFF’). The distinction between narrow and wide builds no longer exists and Python now behaves like a wide build, even under Windows. * With the death of narrow builds, the problems specific to narrow builds have also been fixed, for example: * *note len(): 150. now always returns 1 for non-BMP characters, so ‘len('\U0010FFFF') == 1’; * surrogate pairs are not recombined in string literals, so ‘'\uDBFF\uDFFF' != '\U0010FFFF'’; * indexing or slicing non-BMP characters returns the expected value, so ‘'\U0010FFFF'[0]’ now returns ‘'\U0010FFFF'’ and not ‘'\uDBFF'’; * all other functions in the standard library now correctly handle non-BMP code points. * The value of *note sys.maxunicode: 98b. is now always ‘1114111’ (‘0x10FFFF’ in hexadecimal). The ‘PyUnicode_GetMax()’ function still returns either ‘0xFFFF’ or ‘0x10FFFF’ for backward compatibility, and it should not be used with the new Unicode API (see bpo-13054(2)). * The ‘./configure’ flag ‘--with-wide-unicode’ has been removed. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393 (2) https://bugs.python.org/issue13054  File: python.info, Node: Performance and resource usage, Prev: Functionality, Up: PEP 393 Flexible String Representation 1.6.5.2 Performance and resource usage ...................................... The storage of Unicode strings now depends on the highest code point in the string: * pure ASCII and Latin1 strings (‘U+0000-U+00FF’) use 1 byte per code point; * BMP strings (‘U+0000-U+FFFF’) use 2 bytes per code point; * non-BMP strings (‘U+10000-U+10FFFF’) use 4 bytes per code point. The net effect is that for most applications, memory usage of string storage should decrease significantly - especially compared to former wide unicode builds - as, in many cases, strings will be pure ASCII even in international contexts (because many strings store non-human language data, such as XML fragments, HTTP headers, JSON-encoded data, etc.). We also hope that it will, for the same reasons, increase CPU cache efficiency on non-trivial applications. The memory usage of Python 3.3 is two to three times smaller than Python 3.2, and a little bit better than Python 2.7, on a Django benchmark (see the PEP for details). See also ........ PEP 393(1) - Flexible String Representation PEP written by Martin von Löwis; implementation by Torsten Becker and Martin von Löwis. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393  File: python.info, Node: PEP 397 Python Launcher for Windows, Next: PEP 3151 Reworking the OS and IO exception hierarchy, Prev: PEP 393 Flexible String Representation, Up: What’s New In Python 3 3 1.6.6 PEP 397: Python Launcher for Windows ------------------------------------------ The Python 3.3 Windows installer now includes a ‘py’ launcher application that can be used to launch Python applications in a version independent fashion. This launcher is invoked implicitly when double-clicking ‘*.py’ files. If only a single Python version is installed on the system, that version will be used to run the file. If multiple versions are installed, the most recent version is used by default, but this can be overridden by including a Unix-style “shebang line” in the Python script. The launcher can also be used explicitly from the command line as the ‘py’ application. Running ‘py’ follows the same version selection rules as implicitly launching scripts, but a more specific version can be selected by passing appropriate arguments (such as ‘-3’ to request Python 3 when Python 2 is also installed, or ‘-2.6’ to specifically request an earlier Python version when a more recent version is installed). In addition to the launcher, the Windows installer now includes an option to add the newly installed Python to the system PATH. (Contributed by Brian Curtin in bpo-3561(1).) See also ........ PEP 397(2) - Python Launcher for Windows PEP written by Mark Hammond and Martin v. Löwis; implementation by Vinay Sajip. Launcher documentation: *note Python Launcher for Windows: 98f. Installer PATH modification: *note Finding the Python executable: 990. ---------- Footnotes ---------- (1) https://bugs.python.org/issue3561 (2) https://www.python.org/dev/peps/pep-0397  File: python.info, Node: PEP 3151 Reworking the OS and IO exception hierarchy, Next: PEP 380 Syntax for Delegating to a Subgenerator, Prev: PEP 397 Python Launcher for Windows, Up: What’s New In Python 3 3 1.6.7 PEP 3151: Reworking the OS and IO exception hierarchy ----------------------------------------------------------- The hierarchy of exceptions raised by operating system errors is now both simplified and finer-grained. You don’t have to worry anymore about choosing the appropriate exception type between *note OSError: 1d3, *note IOError: 992, *note EnvironmentError: 993, *note WindowsError: 994, ‘mmap.error’, *note socket.error: 995. or *note select.error: 996. All these exception types are now only one: *note OSError: 1d3. The other names are kept as aliases for compatibility reasons. Also, it is now easier to catch a specific error condition. Instead of inspecting the ‘errno’ attribute (or ‘args[0]’) for a particular constant from the *note errno: 7c. module, you can catch the adequate *note OSError: 1d3. subclass. The available subclasses are the following: * *note BlockingIOError: 997. * *note ChildProcessError: 998. * *note ConnectionError: 6e6. * *note FileExistsError: 958. * *note FileNotFoundError: 7c0. * *note InterruptedError: 659. * *note IsADirectoryError: 999. * *note NotADirectoryError: 99a. * *note PermissionError: 5ff. * *note ProcessLookupError: 99b. * *note TimeoutError: 99c. And the *note ConnectionError: 6e6. itself has finer-grained subclasses: * *note BrokenPipeError: 99d. * *note ConnectionAbortedError: 99e. * *note ConnectionRefusedError: 99f. * *note ConnectionResetError: 9a0. Thanks to the new exceptions, common usages of the *note errno: 7c. can now be avoided. For example, the following code written for Python 3.2: from errno import ENOENT, EACCES, EPERM try: with open("document.txt") as f: content = f.read() except IOError as err: if err.errno == ENOENT: print("document.txt file is missing") elif err.errno in (EACCES, EPERM): print("You are not allowed to read document.txt") else: raise can now be written without the *note errno: 7c. import and without manual inspection of exception attributes: try: with open("document.txt") as f: content = f.read() except FileNotFoundError: print("document.txt file is missing") except PermissionError: print("You are not allowed to read document.txt") See also ........ PEP 3151(1) - Reworking the OS and IO Exception Hierarchy PEP written and implemented by Antoine Pitrou ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3151  File: python.info, Node: PEP 380 Syntax for Delegating to a Subgenerator, Next: PEP 409 Suppressing exception context, Prev: PEP 3151 Reworking the OS and IO exception hierarchy, Up: What’s New In Python 3 3 1.6.8 PEP 380: Syntax for Delegating to a Subgenerator ------------------------------------------------------ PEP 380 adds the ‘yield from’ expression, allowing a *note generator: 9a2. to delegate part of its operations to another generator. This allows a section of code containing *note yield: 18f. to be factored out and placed in another generator. Additionally, the subgenerator is allowed to return with a value, and the value is made available to the delegating generator. While designed primarily for use in delegating to a subgenerator, the ‘yield from’ expression actually allows delegation to arbitrary subiterators. For simple iterators, ‘yield from iterable’ is essentially just a shortened form of ‘for item in iterable: yield item’: >>> def g(x): ... yield from range(x, 0, -1) ... yield from range(x) ... >>> list(g(5)) [5, 4, 3, 2, 1, 0, 1, 2, 3, 4] However, unlike an ordinary loop, ‘yield from’ allows subgenerators to receive sent and thrown values directly from the calling scope, and return a final value to the outer generator: >>> def accumulate(): ... tally = 0 ... while 1: ... next = yield ... if next is None: ... return tally ... tally += next ... >>> def gather_tallies(tallies): ... while 1: ... tally = yield from accumulate() ... tallies.append(tally) ... >>> tallies = [] >>> acc = gather_tallies(tallies) >>> next(acc) # Ensure the accumulator is ready to accept values >>> for i in range(4): ... acc.send(i) ... >>> acc.send(None) # Finish the first tally >>> for i in range(5): ... acc.send(i) ... >>> acc.send(None) # Finish the second tally >>> tallies [6, 10] The main principle driving this change is to allow even generators that are designed to be used with the ‘send’ and ‘throw’ methods to be split into multiple subgenerators as easily as a single large function can be split into multiple subfunctions. See also ........ PEP 380(1) - Syntax for Delegating to a Subgenerator PEP written by Greg Ewing; implementation by Greg Ewing, integrated into 3.3 by Renaud Blanch, Ryan Kelly and Nick Coghlan; documentation by Zbigniew Jędrzejewski-Szmek and Nick Coghlan ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0380  File: python.info, Node: PEP 409 Suppressing exception context, Next: PEP 414 Explicit Unicode literals, Prev: PEP 380 Syntax for Delegating to a Subgenerator, Up: What’s New In Python 3 3 1.6.9 PEP 409: Suppressing exception context -------------------------------------------- PEP 409 introduces new syntax that allows the display of the chained exception context to be disabled. This allows cleaner error messages in applications that convert between exception types: >>> class D: ... def __init__(self, extra): ... self._extra_attributes = extra ... def __getattr__(self, attr): ... try: ... return self._extra_attributes[attr] ... except KeyError: ... raise AttributeError(attr) from None ... >>> D({}).x Traceback (most recent call last): File "", line 1, in File "", line 8, in __getattr__ AttributeError: x Without the ‘from None’ suffix to suppress the cause, the original exception would be displayed by default: >>> class C: ... def __init__(self, extra): ... self._extra_attributes = extra ... def __getattr__(self, attr): ... try: ... return self._extra_attributes[attr] ... except KeyError: ... raise AttributeError(attr) ... >>> C({}).x Traceback (most recent call last): File "", line 6, in __getattr__ KeyError: 'x' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "", line 1, in File "", line 8, in __getattr__ AttributeError: x No debugging capability is lost, as the original exception context remains available if needed (for example, if an intervening library has incorrectly suppressed valuable underlying details): >>> try: ... D({}).x ... except AttributeError as exc: ... print(repr(exc.__context__)) ... KeyError('x',) See also ........ PEP 409(1) - Suppressing exception context PEP written by Ethan Furman; implemented by Ethan Furman and Nick Coghlan. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0409  File: python.info, Node: PEP 414 Explicit Unicode literals, Next: PEP 3155 Qualified name for classes and functions, Prev: PEP 409 Suppressing exception context, Up: What’s New In Python 3 3 1.6.10 PEP 414: Explicit Unicode literals ----------------------------------------- To ease the transition from Python 2 for Unicode aware Python applications that make heavy use of Unicode literals, Python 3.3 once again supports the “‘u’” prefix for string literals. This prefix has no semantic significance in Python 3, it is provided solely to reduce the number of purely mechanical changes in migrating to Python 3, making it easier for developers to focus on the more significant semantic changes (such as the stricter default separation of binary and text data). See also ........ PEP 414(1) - Explicit Unicode literals PEP written by Armin Ronacher. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0414  File: python.info, Node: PEP 3155 Qualified name for classes and functions, Next: PEP 412 Key-Sharing Dictionary, Prev: PEP 414 Explicit Unicode literals, Up: What’s New In Python 3 3 1.6.11 PEP 3155: Qualified name for classes and functions --------------------------------------------------------- Functions and class objects have a new ‘__qualname__’ attribute representing the “path” from the module top-level to their definition. For global functions and classes, this is the same as ‘__name__’. For other functions and classes, it provides better information about where they were actually defined, and how they might be accessible from the global scope. Example with (non-bound) methods: >>> class C: ... def meth(self): ... pass >>> C.meth.__name__ 'meth' >>> C.meth.__qualname__ 'C.meth' Example with nested classes: >>> class C: ... class D: ... def meth(self): ... pass ... >>> C.D.__name__ 'D' >>> C.D.__qualname__ 'C.D' >>> C.D.meth.__name__ 'meth' >>> C.D.meth.__qualname__ 'C.D.meth' Example with nested functions: >>> def outer(): ... def inner(): ... pass ... return inner ... >>> outer().__name__ 'inner' >>> outer().__qualname__ 'outer..inner' The string representation of those objects is also changed to include the new, more precise information: >>> str(C.D) "" >>> str(C.D.meth) '' See also ........ PEP 3155(1) - Qualified name for classes and functions PEP written and implemented by Antoine Pitrou. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3155  File: python.info, Node: PEP 412 Key-Sharing Dictionary, Next: PEP 362 Function Signature Object, Prev: PEP 3155 Qualified name for classes and functions, Up: What’s New In Python 3 3 1.6.12 PEP 412: Key-Sharing Dictionary -------------------------------------- Dictionaries used for the storage of objects’ attributes are now able to share part of their internal storage between each other (namely, the part which stores the keys and their respective hashes). This reduces the memory consumption of programs creating many instances of non-builtin types. See also ........ PEP 412(1) - Key-Sharing Dictionary PEP written and implemented by Mark Shannon. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0412  File: python.info, Node: PEP 362 Function Signature Object, Next: PEP 421 Adding sys implementation, Prev: PEP 412 Key-Sharing Dictionary, Up: What’s New In Python 3 3 1.6.13 PEP 362: Function Signature Object ----------------------------------------- A new function *note inspect.signature(): 55b. makes introspection of python callables easy and straightforward. A broad range of callables is supported: python functions, decorated or not, classes, and *note functools.partial(): 7c8. objects. New classes *note inspect.Signature: 6f3, *note inspect.Parameter: 6f4. and *note inspect.BoundArguments: 9a8. hold information about the call signatures, such as, annotations, default values, parameters kinds, and bound arguments, which considerably simplifies writing decorators and any code that validates or amends calling signatures or arguments. See also ........ PEP 362(1): - Function Signature Object PEP written by Brett Cannon, Yury Selivanov, Larry Hastings, Jiwon Seo; implemented by Yury Selivanov. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0362  File: python.info, Node: PEP 421 Adding sys implementation, Next: Using importlib as the Implementation of Import, Prev: PEP 362 Function Signature Object, Up: What’s New In Python 3 3 1.6.14 PEP 421: Adding sys.implementation ----------------------------------------- A new attribute on the *note sys: fd. module exposes details specific to the implementation of the currently running interpreter. The initial set of attributes on *note sys.implementation: 9aa. are ‘name’, ‘version’, ‘hexversion’, and ‘cache_tag’. The intention of ‘sys.implementation’ is to consolidate into one namespace the implementation-specific data used by the standard library. This allows different Python implementations to share a single standard library code base much more easily. In its initial state, ‘sys.implementation’ holds only a small portion of the implementation-specific data. Over time that ratio will shift in order to make the standard library more portable. One example of improved standard library portability is ‘cache_tag’. As of Python 3.3, ‘sys.implementation.cache_tag’ is used by *note importlib: 9b. to support PEP 3147(1) compliance. Any Python implementation that uses ‘importlib’ for its built-in import system may use ‘cache_tag’ to control the caching behavior for modules. * Menu: * SimpleNamespace:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: SimpleNamespace, Up: PEP 421 Adding sys implementation 1.6.14.1 SimpleNamespace ........................ The implementation of ‘sys.implementation’ also introduces a new type to Python: *note types.SimpleNamespace: 9ac. In contrast to a mapping-based namespace, like *note dict: 1b8, ‘SimpleNamespace’ is attribute-based, like *note object: 2b0. However, unlike ‘object’, ‘SimpleNamespace’ instances are writable. This means that you can add, remove, and modify the namespace through normal attribute access. See also ........ PEP 421(1) - Adding sys.implementation PEP written and implemented by Eric Snow. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0421  File: python.info, Node: Using importlib as the Implementation of Import, Next: Other Language Changes<6>, Prev: PEP 421 Adding sys implementation, Up: What’s New In Python 3 3 1.6.15 Using importlib as the Implementation of Import ------------------------------------------------------ bpo-2377(1) - Replace __import__ w/ importlib.__import__ bpo-13959(2) - Re-implement parts of *note imp: 9a. in pure Python bpo-14605(3) - Make import machinery explicit bpo-14646(4) - Require loaders set __loader__ and __package__ The *note __import__(): 610. function is now powered by *note importlib.__import__(): 9ae. This work leads to the completion of “phase 2” of PEP 302(5). There are multiple benefits to this change. First, it has allowed for more of the machinery powering import to be exposed instead of being implicit and hidden within the C code. It also provides a single implementation for all Python VMs supporting Python 3.3 to use, helping to end any VM-specific deviations in import semantics. And finally it eases the maintenance of import, allowing for future growth to occur. For the common user, there should be no visible change in semantics. For those whose code currently manipulates import or calls import programmatically, the code changes that might possibly be required are covered in the *note Porting Python code: 9af. section of this document. * Menu: * New APIs:: * Visible Changes:: ---------- Footnotes ---------- (1) https://bugs.python.org/issue2377 (2) https://bugs.python.org/issue13959 (3) https://bugs.python.org/issue14605 (4) https://bugs.python.org/issue14646 (5) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: New APIs, Next: Visible Changes, Up: Using importlib as the Implementation of Import 1.6.15.1 New APIs ................. One of the large benefits of this work is the exposure of what goes into making the import statement work. That means the various importers that were once implicit are now fully exposed as part of the *note importlib: 9b. package. The abstract base classes defined in *note importlib.abc: 9c. have been expanded to properly delineate between *note meta path finders: 9b1. and *note path entry finders: 9b2. by introducing *note importlib.abc.MetaPathFinder: 9b3. and *note importlib.abc.PathEntryFinder: 9b4, respectively. The old ABC of *note importlib.abc.Finder: 9b5. is now only provided for backwards-compatibility and does not enforce any method requirements. In terms of finders, *note importlib.machinery.FileFinder: 9b6. exposes the mechanism used to search for source and bytecode files of a module. Previously this class was an implicit member of *note sys.path_hooks: 95c. For loaders, the new abstract base class *note importlib.abc.FileLoader: 9b7. helps write a loader that uses the file system as the storage mechanism for a module’s code. The loader for source files (*note importlib.machinery.SourceFileLoader: 9b8.), sourceless bytecode files (*note importlib.machinery.SourcelessFileLoader: 9b9.), and extension modules (*note importlib.machinery.ExtensionFileLoader: 556.) are now available for direct use. *note ImportError: 334. now has ‘name’ and ‘path’ attributes which are set when there is relevant data to provide. The message for failed imports will also provide the full name of the module now instead of just the tail end of the module’s name. The *note importlib.invalidate_caches(): 49c. function will now call the method with the same name on all finders cached in *note sys.path_importer_cache: 49d. to help clean up any stored state as necessary.  File: python.info, Node: Visible Changes, Prev: New APIs, Up: Using importlib as the Implementation of Import 1.6.15.2 Visible Changes ........................ For potential required changes to code, see the *note Porting Python code: 9af. section. Beyond the expanse of what *note importlib: 9b. now exposes, there are other visible changes to import. The biggest is that *note sys.meta_path: 5e6. and *note sys.path_hooks: 95c. now store all of the meta path finders and path entry hooks used by import. Previously the finders were implicit and hidden within the C code of import instead of being directly exposed. This means that one can now easily remove or change the order of the various finders to fit one’s needs. Another change is that all modules have a ‘__loader__’ attribute, storing the loader used to create the module. PEP 302(1) has been updated to make this attribute mandatory for loaders to implement, so in the future once 3rd-party loaders have been updated people will be able to rely on the existence of the attribute. Until such time, though, import is setting the module post-load. Loaders are also now expected to set the ‘__package__’ attribute from PEP 366(2). Once again, import itself is already setting this on all loaders from *note importlib: 9b. and import itself is setting the attribute post-load. ‘None’ is now inserted into *note sys.path_importer_cache: 49d. when no finder can be found on *note sys.path_hooks: 95c. Since *note imp.NullImporter: 9bb. is not directly exposed on *note sys.path_hooks: 95c. it could no longer be relied upon to always be available to use as a value representing no finder found. All other changes relate to semantic changes which should be taken into consideration when updating code for Python 3.3, and thus should be read about in the *note Porting Python code: 9af. section of this document. (Implementation by Brett Cannon) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0302 (2) https://www.python.org/dev/peps/pep-0366  File: python.info, Node: Other Language Changes<6>, Next: A Finer-Grained Import Lock, Prev: Using importlib as the Implementation of Import, Up: What’s New In Python 3 3 1.6.16 Other Language Changes ----------------------------- Some smaller changes made to the core Python language are: * Added support for Unicode name aliases and named sequences. Both *note unicodedata.lookup(): 9bd. and ‘'\N{...}'’ now resolve name aliases, and *note unicodedata.lookup(): 9bd. resolves named sequences too. (Contributed by Ezio Melotti in bpo-12753(1).) * Unicode database updated to UCD version 6.1.0 * Equality comparisons on *note range(): 9be. objects now return a result reflecting the equality of the underlying sequences generated by those range objects. (bpo-13201(2)) * The ‘count()’, ‘find()’, ‘rfind()’, ‘index()’ and ‘rindex()’ methods of *note bytes: 331. and *note bytearray: 332. objects now accept an integer between 0 and 255 as their first argument. (Contributed by Petri Lehtinen in bpo-12170(3).) * The ‘rjust()’, ‘ljust()’, and ‘center()’ methods of *note bytes: 331. and *note bytearray: 332. now accept a *note bytearray: 332. for the ‘fill’ argument. (Contributed by Petri Lehtinen in bpo-12380(4).) * New methods have been added to *note list: 262. and *note bytearray: 332.: ‘copy()’ and ‘clear()’ (bpo-10516(5)). Consequently, *note MutableSequence: 6ac. now also defines a ‘clear()’ method (bpo-11388(6)). * Raw bytes literals can now be written ‘rb"..."’ as well as ‘br"..."’. (Contributed by Antoine Pitrou in bpo-13748(7).) * *note dict.setdefault(): 9bf. now does only one lookup for the given key, making it atomic when used with built-in types. (Contributed by Filip Gruszczyński in bpo-13521(8).) * The error messages produced when a function call does not match the function signature have been significantly improved. (Contributed by Benjamin Peterson.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12753 (2) https://bugs.python.org/issue13201 (3) https://bugs.python.org/issue12170 (4) https://bugs.python.org/issue12380 (5) https://bugs.python.org/issue10516 (6) https://bugs.python.org/issue11388 (7) https://bugs.python.org/issue13748 (8) https://bugs.python.org/issue13521  File: python.info, Node: A Finer-Grained Import Lock, Next: Builtin functions and types, Prev: Other Language Changes<6>, Up: What’s New In Python 3 3 1.6.17 A Finer-Grained Import Lock ---------------------------------- Previous versions of CPython have always relied on a global import lock. This led to unexpected annoyances, such as deadlocks when importing a module would trigger code execution in a different thread as a side-effect. Clumsy workarounds were sometimes employed, such as the *note PyImport_ImportModuleNoBlock(): 9c1. C API function. In Python 3.3, importing a module takes a per-module lock. This correctly serializes importation of a given module from multiple threads (preventing the exposure of incompletely initialized modules), while eliminating the aforementioned annoyances. (Contributed by Antoine Pitrou in bpo-9260(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9260  File: python.info, Node: Builtin functions and types, Next: New Modules<6>, Prev: A Finer-Grained Import Lock, Up: What’s New In Python 3 3 1.6.18 Builtin functions and types ---------------------------------- * *note open(): 4f0. gets a new `opener' parameter: the underlying file descriptor for the file object is then obtained by calling `opener' with (`file', `flags'). It can be used to use custom flags like *note os.O_CLOEXEC: 9c3. for example. The ‘'x'’ mode was added: open for exclusive creation, failing if the file already exists. * *note print(): 886.: added the `flush' keyword argument. If the `flush' keyword argument is true, the stream is forcibly flushed. * *note hash(): 9c4.: hash randomization is enabled by default, see *note object.__hash__(): 340. and *note PYTHONHASHSEED: 9c5. * The *note str: 330. type gets a new *note casefold(): 6b0. method: return a casefolded copy of the string, casefolded strings may be used for caseless matching. For example, ‘'ß'.casefold()’ returns ‘'ss'’. * The sequence documentation has been substantially rewritten to better explain the binary/text sequence distinction and to provide specific documentation sections for the individual builtin sequence types (bpo-4966(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue4966  File: python.info, Node: New Modules<6>, Next: Improved Modules<6>, Prev: Builtin functions and types, Up: What’s New In Python 3 3 1.6.19 New Modules ------------------ * Menu: * faulthandler: faulthandler<3>. * ipaddress: ipaddress<4>. * lzma: lzma<2>.  File: python.info, Node: faulthandler<3>, Next: ipaddress<4>, Up: New Modules<6> 1.6.19.1 faulthandler ..................... This new debug module *note faulthandler: 7d. contains functions to dump Python tracebacks explicitly, on a fault (a crash like a segmentation fault), after a timeout, or on a user signal. Call *note faulthandler.enable(): 548. to install fault handlers for the ‘SIGSEGV’, ‘SIGFPE’, ‘SIGABRT’, ‘SIGBUS’, and ‘SIGILL’ signals. You can also enable them at startup by setting the *note PYTHONFAULTHANDLER: 9c8. environment variable or by using *note -X: 155. ‘faulthandler’ command line option. Example of a segmentation fault on Linux: $ python -q -X faulthandler >>> import ctypes >>> ctypes.string_at(0) Fatal Python error: Segmentation fault Current thread 0x00007fb899f39700: File "/home/python/cpython/Lib/ctypes/__init__.py", line 486 in string_at File "", line 1 in Segmentation fault  File: python.info, Node: ipaddress<4>, Next: lzma<2>, Prev: faulthandler<3>, Up: New Modules<6> 1.6.19.2 ipaddress .................. The new *note ipaddress: a2. module provides tools for creating and manipulating objects representing IPv4 and IPv6 addresses, networks and interfaces (i.e. an IP address associated with a specific IP subnet). (Contributed by Google and Peter Moody in PEP 3144(1).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3144  File: python.info, Node: lzma<2>, Prev: ipaddress<4>, Up: New Modules<6> 1.6.19.3 lzma ............. The newly-added *note lzma: ad. module provides data compression and decompression using the LZMA algorithm, including support for the ‘.xz’ and ‘.lzma’ file formats. (Contributed by Nadeem Vawda and Per Øyvind Karlsen in bpo-6715(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6715  File: python.info, Node: Improved Modules<6>, Next: Optimizations<5>, Prev: New Modules<6>, Up: What’s New In Python 3 3 1.6.20 Improved Modules ----------------------- * Menu: * abc: abc<2>. * array: array<2>. * base64: base64<2>. * binascii: binascii<3>. * bz2: bz2<2>. * codecs:: * collections: collections<7>. * contextlib: contextlib<5>. * crypt: crypt<2>. * curses: curses<3>. * datetime: datetime<4>. * decimal: decimal<3>. * email: email<4>. * ftplib:: * functools: functools<5>. * gc: gc<4>. * hmac: hmac<3>. * http: http<3>. * html: html<2>. * imaplib: imaplib<2>. * inspect: inspect<5>. * io: io<4>. * itertools: itertools<3>. * logging: logging<6>. * math: math<5>. * mmap: mmap<3>. * multiprocessing: multiprocessing<6>. * nntplib:: * os: os<7>. * pdb: pdb<4>. * pickle: pickle<5>. * pydoc: pydoc<4>. * re: re<6>. * sched:: * select: select<2>. * shlex: shlex<3>. * shutil: shutil<4>. * signal: signal<3>. * smtpd: smtpd<3>. * smtplib: smtplib<3>. * socket: socket<7>. * socketserver: socketserver<3>. * sqlite3: sqlite3<5>. * ssl: ssl<8>. * stat: stat<2>. * struct: struct<3>. * subprocess: subprocess<5>. * sys: sys<7>. * tarfile: tarfile<4>. * tempfile:: * textwrap: textwrap<2>. * threading: threading<5>. * time: time<5>. * types: types<4>. * unittest: unittest<5>. * urllib: urllib<3>. * webbrowser:: * xml.etree.ElementTree: xml etree ElementTree. * zlib: zlib<2>.  File: python.info, Node: abc<2>, Next: array<2>, Up: Improved Modules<6> 1.6.20.1 abc ............ Improved support for abstract base classes containing descriptors composed with abstract methods. The recommended approach to declaring abstract descriptors is now to provide ‘__isabstractmethod__’ as a dynamically updated property. The built-in descriptors have been updated accordingly. * *note abc.abstractproperty: 9cd. has been deprecated, use *note property: 1d7. with *note abc.abstractmethod(): 9ce. instead. * *note abc.abstractclassmethod: 9cf. has been deprecated, use *note classmethod: 1d8. with *note abc.abstractmethod(): 9ce. instead. * *note abc.abstractstaticmethod: 9d0. has been deprecated, use *note staticmethod: 1d9. with *note abc.abstractmethod(): 9ce. instead. (Contributed by Darren Dale in bpo-11610(1).) *note abc.ABCMeta.register(): 9d1. now returns the registered subclass, which means it can now be used as a class decorator (bpo-10868(2)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue11610 (2) https://bugs.python.org/issue10868  File: python.info, Node: array<2>, Next: base64<2>, Prev: abc<2>, Up: Improved Modules<6> 1.6.20.2 array .............. The *note array: 7. module supports the ‘long long’ type using ‘q’ and ‘Q’ type codes. (Contributed by Oren Tirosh and Hirokazu Yamamoto in bpo-1172711(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1172711  File: python.info, Node: base64<2>, Next: binascii<3>, Prev: array<2>, Up: Improved Modules<6> 1.6.20.3 base64 ............... ASCII-only Unicode strings are now accepted by the decoding functions of the *note base64: e. modern interface. For example, ‘base64.b64decode('YWJj')’ returns ‘b'abc'’. (Contributed by Catalin Iacob in bpo-13641(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13641  File: python.info, Node: binascii<3>, Next: bz2<2>, Prev: base64<2>, Up: Improved Modules<6> 1.6.20.4 binascii ................. In addition to the binary objects they normally accept, the ‘a2b_’ functions now all also accept ASCII-only strings as input. (Contributed by Antoine Pitrou in bpo-13637(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13637  File: python.info, Node: bz2<2>, Next: codecs, Prev: binascii<3>, Up: Improved Modules<6> 1.6.20.5 bz2 ............ The *note bz2: 14. module has been rewritten from scratch. In the process, several new features have been added: * New *note bz2.open(): 9d6. function: open a bzip2-compressed file in binary or text mode. * *note bz2.BZ2File: 931. can now read from and write to arbitrary file-like objects, by means of its constructor’s `fileobj' argument. (Contributed by Nadeem Vawda in bpo-5863(1).) * *note bz2.BZ2File: 931. and *note bz2.decompress(): 9d7. can now decompress multi-stream inputs (such as those produced by the ‘pbzip2’ tool). *note bz2.BZ2File: 931. can now also be used to create this type of file, using the ‘'a'’ (append) mode. (Contributed by Nir Aides in bpo-1625(2).) * *note bz2.BZ2File: 931. now implements all of the *note io.BufferedIOBase: 588. API, except for the ‘detach()’ and ‘truncate()’ methods. ---------- Footnotes ---------- (1) https://bugs.python.org/issue5863 (2) https://bugs.python.org/issue1625  File: python.info, Node: codecs, Next: collections<7>, Prev: bz2<2>, Up: Improved Modules<6> 1.6.20.6 codecs ............... The *note mbcs: 78. codec has been rewritten to handle correctly ‘replace’ and ‘ignore’ error handlers on all Windows versions. The *note mbcs: 78. codec now supports all error handlers, instead of only ‘replace’ to encode and ‘ignore’ to decode. A new Windows-only codec has been added: ‘cp65001’ (bpo-13216(1)). It is the Windows code page 65001 (Windows UTF-8, ‘CP_UTF8’). For example, it is used by ‘sys.stdout’ if the console output code page is set to cp65001 (e.g., using ‘chcp 65001’ command). Multibyte CJK decoders now resynchronize faster. They only ignore the first byte of an invalid byte sequence. For example, ‘b'\xff\n'.decode('gb2312', 'replace')’ now returns a ‘\n’ after the replacement character. (bpo-12016(2)) Incremental CJK codec encoders are no longer reset at each call to their encode() methods. For example: >>> import codecs >>> encoder = codecs.getincrementalencoder('hz')('strict') >>> b''.join(encoder.encode(x) for x in '\u52ff\u65bd\u65bc\u4eba\u3002 Bye.') b'~{NpJ)l6HK!#~} Bye.' This example gives ‘b'~{Np~}~{J)~}~{l6~}~{HK~}~{!#~} Bye.'’ with older Python versions. (bpo-12100(3)) The ‘unicode_internal’ codec has been deprecated. ---------- Footnotes ---------- (1) https://bugs.python.org/issue13216 (2) https://bugs.python.org/issue12016 (3) https://bugs.python.org/issue12100  File: python.info, Node: collections<7>, Next: contextlib<5>, Prev: codecs, Up: Improved Modules<6> 1.6.20.7 collections .................... Addition of a new *note ChainMap: 4a9. class to allow treating a number of mappings as a single unit. (Written by Raymond Hettinger for bpo-11089(1), made public in bpo-11297(2).) The abstract base classes have been moved in a new *note collections.abc: 1f. module, to better differentiate between the abstract and the concrete collections classes. Aliases for ABCs are still present in the *note collections: 1e. module to preserve existing imports. (bpo-11085(3)) The *note Counter: 9da. class now supports the unary ‘+’ and ‘-’ operators, as well as the in-place operators ‘+=’, ‘-=’, ‘|=’, and ‘&=’. (Contributed by Raymond Hettinger in bpo-13121(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11089 (2) https://bugs.python.org/issue11297 (3) https://bugs.python.org/issue11085 (4) https://bugs.python.org/issue13121  File: python.info, Node: contextlib<5>, Next: crypt<2>, Prev: collections<7>, Up: Improved Modules<6> 1.6.20.8 contextlib ................... *note ExitStack: 376. now provides a solid foundation for programmatic manipulation of context managers and similar cleanup functionality. Unlike the previous ‘contextlib.nested’ API (which was deprecated and removed), the new API is designed to work correctly regardless of whether context managers acquire their resources in their ‘__init__’ method (for example, file objects) or in their ‘__enter__’ method (for example, synchronisation objects from the *note threading: 109. module). (bpo-13585(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13585  File: python.info, Node: crypt<2>, Next: curses<3>, Prev: contextlib<5>, Up: Improved Modules<6> 1.6.20.9 crypt .............. Addition of salt and modular crypt format (hashing method) and the *note mksalt(): 37c. function to the *note crypt: 29. module. (bpo-10924(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10924  File: python.info, Node: curses<3>, Next: datetime<4>, Prev: crypt<2>, Up: Improved Modules<6> 1.6.20.10 curses ................ * If the *note curses: 2c. module is linked to the ncursesw library, use Unicode functions when Unicode strings or characters are passed (e.g. ‘waddwstr()’), and bytes functions otherwise (e.g. ‘waddstr()’). * Use the locale encoding instead of ‘utf-8’ to encode Unicode strings. * ‘curses.window’ has a new *note curses.window.encoding: 9de. attribute. * The ‘curses.window’ class has a new *note get_wch(): 9df. method to get a wide character * The *note curses: 2c. module has a new *note unget_wch(): 9e0. function to push a wide character so the next *note get_wch(): 9df. will return it (Contributed by Iñigo Serna in bpo-6755(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6755  File: python.info, Node: datetime<4>, Next: decimal<3>, Prev: curses<3>, Up: Improved Modules<6> 1.6.20.11 datetime .................. * Equality comparisons between naive and aware *note datetime: 194. instances now return *note False: 388. instead of raising *note TypeError: 192. (bpo-15006(1)). * New *note datetime.datetime.timestamp(): 9e2. method: Return POSIX timestamp corresponding to the *note datetime: 194. instance. * The *note datetime.datetime.strftime(): 537. method supports formatting years older than 1000. * The *note datetime.datetime.astimezone(): 196. method can now be called without arguments to convert datetime instance to the system timezone. ---------- Footnotes ---------- (1) https://bugs.python.org/issue15006  File: python.info, Node: decimal<3>, Next: email<4>, Prev: datetime<4>, Up: Improved Modules<6> 1.6.20.12 decimal ................. bpo-7652(1) - integrate fast native decimal arithmetic. C-module and libmpdec written by Stefan Krah. The new C version of the decimal module integrates the high speed libmpdec library for arbitrary precision correctly-rounded decimal floating point arithmetic. libmpdec conforms to IBM’s General Decimal Arithmetic Specification. Performance gains range from 10x for database applications to 100x for numerically intensive applications. These numbers are expected gains for standard precisions used in decimal floating point arithmetic. Since the precision is user configurable, the exact figures may vary. For example, in integer bignum arithmetic the differences can be significantly higher. The following table is meant as an illustration. Benchmarks are available at ‘http://www.bytereef.org/mpdecimal/quickstart.html’. decimal.py _decimal speedup --------------------------------------------------------------------- pi 42.02s 0.345s 120x telco 172.19s 5.68s 30x psycopg 3.57s 0.29s 12x * Menu: * Features: Features<2>. * API changes: API changes<2>. ---------- Footnotes ---------- (1) https://bugs.python.org/issue7652  File: python.info, Node: Features<2>, Next: API changes<2>, Up: decimal<3> 1.6.20.13 Features .................. * The *note FloatOperation: 9e5. signal optionally enables stricter semantics for mixing floats and Decimals. * If Python is compiled without threads, the C version automatically disables the expensive thread local context machinery. In this case, the variable *note HAVE_THREADS: 9e6. is set to ‘False’.  File: python.info, Node: API changes<2>, Prev: Features<2>, Up: decimal<3> 1.6.20.14 API changes ..................... * The C module has the following context limits, depending on the machine architecture: 32-bit 64-bit ------------------------------------------------------------------------------------- ‘MAX_PREC’ ‘425000000’ ‘999999999999999999’ ‘MAX_EMAX’ ‘425000000’ ‘999999999999999999’ ‘MIN_EMIN’ ‘-425000000’ ‘-999999999999999999’ * In the context templates (*note DefaultContext: 9e8, *note BasicContext: 9e9. and *note ExtendedContext: 9ea.) the magnitude of ‘Emax’ and ‘Emin’ has changed to ‘999999’. * The *note Decimal: 188. constructor in decimal.py does not observe the context limits and converts values with arbitrary exponents or precision exactly. Since the C version has internal limits, the following scheme is used: If possible, values are converted exactly, otherwise *note InvalidOperation: 9eb. is raised and the result is NaN. In the latter case it is always possible to use *note create_decimal(): 9ec. in order to obtain a rounded or inexact value. * The power function in decimal.py is always correctly-rounded. In the C version, it is defined in terms of the correctly-rounded *note exp(): 9ed. and *note ln(): 9ee. functions, but the final result is only “almost always correctly rounded”. * In the C version, the context dictionary containing the signals is a *note MutableMapping: 9ef. For speed reasons, ‘flags’ and ‘traps’ always refer to the same *note MutableMapping: 9ef. that the context was initialized with. If a new signal dictionary is assigned, ‘flags’ and ‘traps’ are updated with the new values, but they do not reference the RHS dictionary. * Pickling a *note Context: 9f0. produces a different output in order to have a common interchange format for the Python and C versions. * The order of arguments in the *note Context: 9f0. constructor has been changed to match the order displayed by *note repr(): 7cc. * The ‘watchexp’ parameter in the *note quantize(): 9f1. method is deprecated.  File: python.info, Node: email<4>, Next: ftplib, Prev: decimal<3>, Up: Improved Modules<6> 1.6.20.15 email ............... * Menu: * Policy Framework:: * Provisional Policy with New Header API:: * Other API Changes::  File: python.info, Node: Policy Framework, Next: Provisional Policy with New Header API, Up: email<4> 1.6.20.16 Policy Framework .......................... The email package now has a *note policy: 75. framework. A *note Policy: 9f4. is an object with several methods and properties that control how the email package behaves. The primary policy for Python 3.3 is the *note Compat32: 9f5. policy, which provides backward compatibility with the email package in Python 3.2. A ‘policy’ can be specified when an email message is parsed by a *note parser: 74, or when a *note Message: 541. object is created, or when an email is serialized using a *note generator: 6e. Unless overridden, a policy passed to a ‘parser’ is inherited by all the ‘Message’ object and sub-objects created by the ‘parser’. By default a ‘generator’ will use the policy of the ‘Message’ object it is serializing. The default policy is *note compat32: 540. The minimum set of controls implemented by all ‘policy’ objects are: max_line_length The maximum length, excluding the linesep character(s), individual lines may have when a ‘Message’ is serialized. Defaults to 78. linesep The character used to separate individual lines when a ‘Message’ is serialized. Defaults to ‘\n’. cte_type ‘7bit’ or ‘8bit’. ‘8bit’ applies only to a ‘Bytes’ ‘generator’, and means that non-ASCII may be used where allowed by the protocol (or where it exists in the original input). raise_on_defect Causes a ‘parser’ to raise error when defects are encountered instead of adding them to the ‘Message’ object’s ‘defects’ list. A new policy instance, with new settings, is created using the *note clone(): 9f6. method of policy objects. ‘clone’ takes any of the above controls as keyword arguments. Any control not specified in the call retains its default value. Thus you can create a policy that uses ‘\r\n’ linesep characters like this: mypolicy = compat32.clone(linesep='\r\n') Policies can be used to make the generation of messages in the format needed by your application simpler. Instead of having to remember to specify ‘linesep='\r\n'’ in all the places you call a ‘generator’, you can specify it once, when you set the policy used by the ‘parser’ or the ‘Message’, whichever your program uses to create ‘Message’ objects. On the other hand, if you need to generate messages in multiple forms, you can still specify the parameters in the appropriate ‘generator’ call. Or you can have custom policy instances for your different cases, and pass those in when you create the ‘generator’.  File: python.info, Node: Provisional Policy with New Header API, Next: Other API Changes, Prev: Policy Framework, Up: email<4> 1.6.20.17 Provisional Policy with New Header API ................................................ While the policy framework is worthwhile all by itself, the main motivation for introducing it is to allow the creation of new policies that implement new features for the email package in a way that maintains backward compatibility for those who do not use the new policies. Because the new policies introduce a new API, we are releasing them in Python 3.3 as a *note provisional policy: 980. Backwards incompatible changes (up to and including removal of the code) may occur if deemed necessary by the core developers. The new policies are instances of *note EmailPolicy: 9f8, and add the following additional controls: refold_source Controls whether or not headers parsed by a *note parser: 74. are refolded by the *note generator: 6e. It can be ‘none’, ‘long’, or ‘all’. The default is ‘long’, which means that source headers with a line longer than ‘max_line_length’ get refolded. ‘none’ means no line get refolded, and ‘all’ means that all lines get refolded. header_factory A callable that take a ‘name’ and ‘value’ and produces a custom header object. The ‘header_factory’ is the key to the new features provided by the new policies. When one of the new policies is used, any header retrieved from a ‘Message’ object is an object produced by the ‘header_factory’, and any time you set a header on a ‘Message’ it becomes an object produced by ‘header_factory’. All such header objects have a ‘name’ attribute equal to the header name. Address and Date headers have additional attributes that give you access to the parsed data of the header. This means you can now do things like this: >>> m = Message(policy=SMTP) >>> m['To'] = 'Éric ' >>> m['to'] 'Éric ' >>> m['to'].addresses (Address(display_name='Éric', username='foo', domain='example.com'),) >>> m['to'].addresses[0].username 'foo' >>> m['to'].addresses[0].display_name 'Éric' >>> m['Date'] = email.utils.localtime() >>> m['Date'].datetime datetime.datetime(2012, 5, 25, 21, 39, 24, 465484, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000), 'EDT')) >>> m['Date'] 'Fri, 25 May 2012 21:44:27 -0400' >>> print(m) To: =?utf-8?q?=C3=89ric?= Date: Fri, 25 May 2012 21:44:27 -0400 You will note that the unicode display name is automatically encoded as ‘utf-8’ when the message is serialized, but that when the header is accessed directly, you get the unicode version. This eliminates any need to deal with the *note email.header: 6f. *note decode_header(): 9f9. or *note make_header(): 9fa. functions. You can also create addresses from parts: >>> m['cc'] = [Group('pals', [Address('Bob', 'bob', 'example.com'), ... Address('Sally', 'sally', 'example.com')]), ... Address('Bonzo', addr_spec='bonz@laugh.com')] >>> print(m) To: =?utf-8?q?=C3=89ric?= Date: Fri, 25 May 2012 21:44:27 -0400 cc: pals: Bob , Sally ;, Bonzo Decoding to unicode is done automatically: >>> m2 = message_from_string(str(m)) >>> m2['to'] 'Éric ' When you parse a message, you can use the ‘addresses’ and ‘groups’ attributes of the header objects to access the groups and individual addresses: >>> m2['cc'].addresses (Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com'), Address(display_name='Bonzo', username='bonz', domain='laugh.com')) >>> m2['cc'].groups (Group(display_name='pals', addresses=(Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com')), Group(display_name=None, addresses=(Address(display_name='Bonzo', username='bonz', domain='laugh.com'),)) In summary, if you use one of the new policies, header manipulation works the way it ought to: your application works with unicode strings, and the email package transparently encodes and decodes the unicode to and from the RFC standard Content Transfer Encodings.  File: python.info, Node: Other API Changes, Prev: Provisional Policy with New Header API, Up: email<4> 1.6.20.18 Other API Changes ........................... New *note BytesHeaderParser: 9fc, added to the *note parser: 74. module to complement *note HeaderParser: 9fd. and complete the Bytes API. New utility functions: * *note format_datetime(): 9fe.: given a *note datetime: 194, produce a string formatted for use in an email header. * *note parsedate_to_datetime(): 9ff.: given a date string from an email header, convert it into an aware *note datetime: 194, or a naive *note datetime: 194. if the offset is ‘-0000’. * *note localtime(): a00.: With no argument, returns the current local time as an aware *note datetime: 194. using the local *note timezone: a01. Given an aware *note datetime: 194, converts it into an aware *note datetime: 194. using the local *note timezone: a01.  File: python.info, Node: ftplib, Next: functools<5>, Prev: email<4>, Up: Improved Modules<6> 1.6.20.19 ftplib ................ * *note ftplib.FTP: 2f0. now accepts a ‘source_address’ keyword argument to specify the ‘(host, port)’ to use as the source address in the bind call when creating the outgoing socket. (Contributed by Giampaolo Rodolà in bpo-8594(1).) * The *note FTP_TLS: a03. class now provides a new *note ccc(): a04. function to revert control channel back to plaintext. This can be useful to take advantage of firewalls that know how to handle NAT with non-secure FTP without opening fixed ports. (Contributed by Giampaolo Rodolà in bpo-12139(2).) * Added *note ftplib.FTP.mlsd(): a05. method which provides a parsable directory listing format and deprecates *note ftplib.FTP.nlst(): a06. and *note ftplib.FTP.dir(): a07. (Contributed by Giampaolo Rodolà in bpo-11072(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8594 (2) https://bugs.python.org/issue12139 (3) https://bugs.python.org/issue11072  File: python.info, Node: functools<5>, Next: gc<4>, Prev: ftplib, Up: Improved Modules<6> 1.6.20.20 functools ................... The *note functools.lru_cache(): 1c7. decorator now accepts a ‘typed’ keyword argument (that defaults to ‘False’ to ensure that it caches values of different types that compare equal in separate cache slots. (Contributed by Raymond Hettinger in bpo-13227(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13227  File: python.info, Node: gc<4>, Next: hmac<3>, Prev: functools<5>, Up: Improved Modules<6> 1.6.20.21 gc ............ It is now possible to register callbacks invoked by the garbage collector before and after collection using the new *note callbacks: a0a. list.  File: python.info, Node: hmac<3>, Next: http<3>, Prev: gc<4>, Up: Improved Modules<6> 1.6.20.22 hmac .............. A new *note compare_digest(): a0c. function has been added to prevent side channel attacks on digests through timing analysis. (Contributed by Nick Coghlan and Christian Heimes in bpo-15061(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15061  File: python.info, Node: http<3>, Next: html<2>, Prev: hmac<3>, Up: Improved Modules<6> 1.6.20.23 http .............. *note http.server.BaseHTTPRequestHandler: a0e. now buffers the headers and writes them all at once when *note end_headers(): a0f. is called. A new method *note flush_headers(): a10. can be used to directly manage when the accumulated headers are sent. (Contributed by Andrew Schaaf in bpo-3709(1).) *note http.server: 97. now produces valid ‘HTML 4.01 strict’ output. (Contributed by Ezio Melotti in bpo-13295(2).) *note http.client.HTTPResponse: a11. now has a *note readinto(): a12. method, which means it can be used as an *note io.RawIOBase: a13. class. (Contributed by John Kuhn in bpo-13464(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue3709 (2) https://bugs.python.org/issue13295 (3) https://bugs.python.org/issue13464  File: python.info, Node: html<2>, Next: imaplib<2>, Prev: http<3>, Up: Improved Modules<6> 1.6.20.24 html .............. *note html.parser.HTMLParser: 7bf. is now able to parse broken markup without raising errors, therefore the `strict' argument of the constructor and the ‘HTMLParseError’ exception are now deprecated. The ability to parse broken markup is the result of a number of bug fixes that are also available on the latest bug fix releases of Python 2.7/3.2. (Contributed by Ezio Melotti in bpo-15114(1), and bpo-14538(2), bpo-13993(3), bpo-13960(4), bpo-13358(5), bpo-1745761(6), bpo-755670(7), bpo-13357(8), bpo-12629(9), bpo-1200313(10), bpo-670664(11), bpo-13273(12), bpo-12888(13), bpo-7311(14).) A new *note html5: a15. dictionary that maps HTML5 named character references to the equivalent Unicode character(s) (e.g. ‘html5['gt;'] == '>'’) has been added to the *note html.entities: 91. module. The dictionary is now also used by *note HTMLParser: 7bf. (Contributed by Ezio Melotti in bpo-11113(15) and bpo-15156(16).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue15114 (2) https://bugs.python.org/issue14538 (3) https://bugs.python.org/issue13993 (4) https://bugs.python.org/issue13960 (5) https://bugs.python.org/issue13358 (6) https://bugs.python.org/issue1745761 (7) https://bugs.python.org/issue755670 (8) https://bugs.python.org/issue13357 (9) https://bugs.python.org/issue12629 (10) https://bugs.python.org/issue1200313 (11) https://bugs.python.org/issue670664 (12) https://bugs.python.org/issue13273 (13) https://bugs.python.org/issue12888 (14) https://bugs.python.org/issue7311 (15) https://bugs.python.org/issue11113 (16) https://bugs.python.org/issue15156  File: python.info, Node: imaplib<2>, Next: inspect<5>, Prev: html<2>, Up: Improved Modules<6> 1.6.20.25 imaplib ................. The *note IMAP4_SSL: a17. constructor now accepts an SSLContext parameter to control parameters of the secure channel. (Contributed by Sijin Joseph in bpo-8808(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8808  File: python.info, Node: inspect<5>, Next: io<4>, Prev: imaplib<2>, Up: Improved Modules<6> 1.6.20.26 inspect ................. A new *note getclosurevars(): a19. function has been added. This function reports the current binding of all names referenced from the function body and where those names were resolved, making it easier to verify correct internal state when testing code that relies on stateful closures. (Contributed by Meador Inge and Nick Coghlan in bpo-13062(1).) A new *note getgeneratorlocals(): a1a. function has been added. This function reports the current binding of local variables in the generator’s stack frame, making it easier to verify correct internal state when testing generators. (Contributed by Meador Inge in bpo-15153(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13062 (2) https://bugs.python.org/issue15153  File: python.info, Node: io<4>, Next: itertools<3>, Prev: inspect<5>, Up: Improved Modules<6> 1.6.20.27 io ............ The *note open(): 65a. function has a new ‘'x'’ mode that can be used to exclusively create a new file, and raise a *note FileExistsError: 958. if the file already exists. It is based on the C11 ‘x’ mode to fopen(). (Contributed by David Townshend in bpo-12760(1).) The constructor of the *note TextIOWrapper: 5f3. class has a new `write_through' optional argument. If `write_through' is ‘True’, calls to ‘write()’ are guaranteed not to be buffered: any data written on the *note TextIOWrapper: 5f3. object is immediately handled to its underlying binary buffer. ---------- Footnotes ---------- (1) https://bugs.python.org/issue12760  File: python.info, Node: itertools<3>, Next: logging<6>, Prev: io<4>, Up: Improved Modules<6> 1.6.20.28 itertools ................... *note accumulate(): 1dd. now takes an optional ‘func’ argument for providing a user-supplied binary function.  File: python.info, Node: logging<6>, Next: math<5>, Prev: itertools<3>, Up: Improved Modules<6> 1.6.20.29 logging ................. The *note basicConfig(): 1e0. function now supports an optional ‘handlers’ argument taking an iterable of handlers to be added to the root logger. A class level attribute ‘append_nul’ has been added to *note SysLogHandler: a1e. to allow control of the appending of the ‘NUL’ (‘\000’) byte to syslog records, since for some daemons it is required while for others it is passed through to the log.  File: python.info, Node: math<5>, Next: mmap<3>, Prev: logging<6>, Up: Improved Modules<6> 1.6.20.30 math .............. The *note math: b1. module has a new function, *note log2(): a20, which returns the base-2 logarithm of `x'. (Written by Mark Dickinson in bpo-11888(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11888  File: python.info, Node: mmap<3>, Next: multiprocessing<6>, Prev: math<5>, Up: Improved Modules<6> 1.6.20.31 mmap .............. The *note read(): a22. method is now more compatible with other file-like objects: if the argument is omitted or specified as ‘None’, it returns the bytes from the current file position to the end of the mapping. (Contributed by Petri Lehtinen in bpo-12021(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12021  File: python.info, Node: multiprocessing<6>, Next: nntplib, Prev: mmap<3>, Up: Improved Modules<6> 1.6.20.32 multiprocessing ......................... The new *note multiprocessing.connection.wait(): a24. function allows polling multiple objects (such as connections, sockets and pipes) with a timeout. (Contributed by Richard Oudkerk in bpo-12328(1).) ‘multiprocessing.Connection’ objects can now be transferred over multiprocessing connections. (Contributed by Richard Oudkerk in bpo-4892(2).) *note multiprocessing.Process: 3b2. now accepts a ‘daemon’ keyword argument to override the default behavior of inheriting the ‘daemon’ flag from the parent process (bpo-6064(3)). New attribute *note multiprocessing.Process.sentinel: a25. allows a program to wait on multiple *note Process: 3b2. objects at one time using the appropriate OS primitives (for example, *note select: e5. on posix systems). New methods *note multiprocessing.pool.Pool.starmap(): a26. and *note starmap_async(): a27. provide *note itertools.starmap(): a28. equivalents to the existing *note multiprocessing.pool.Pool.map(): a29. and *note map_async(): a2a. functions. (Contributed by Hynek Schlawack in bpo-12708(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12328 (2) https://bugs.python.org/issue4892 (3) https://bugs.python.org/issue6064 (4) https://bugs.python.org/issue12708  File: python.info, Node: nntplib, Next: os<7>, Prev: multiprocessing<6>, Up: Improved Modules<6> 1.6.20.33 nntplib ................. The *note nntplib.NNTP: a2c. class now supports the context management protocol to unconditionally consume *note socket.error: 995. exceptions and to close the NNTP connection when done: >>> from nntplib import NNTP >>> with NNTP('news.gmane.org') as n: ... n.group('gmane.comp.python.committers') ... ('211 1755 1 1755 gmane.comp.python.committers', 1755, 1, 1755, 'gmane.comp.python.committers') >>> (Contributed by Giampaolo Rodolà in bpo-9795(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9795  File: python.info, Node: os<7>, Next: pdb<4>, Prev: nntplib, Up: Improved Modules<6> 1.6.20.34 os ............ * The *note os: c4. module has a new *note pipe2(): a2e. function that makes it possible to create a pipe with *note O_CLOEXEC: 9c3. or *note O_NONBLOCK: 723. flags set atomically. This is especially useful to avoid race conditions in multi-threaded programs. * The *note os: c4. module has a new *note sendfile(): 359. function which provides an efficient “zero-copy” way for copying data from one file (or socket) descriptor to another. The phrase “zero-copy” refers to the fact that all of the copying of data between the two descriptors is done entirely by the kernel, with no copying of data into userspace buffers. *note sendfile(): 359. can be used to efficiently copy data from a file on disk to a network socket, e.g. for downloading a file. (Patch submitted by Ross Lagerwall and Giampaolo Rodolà in bpo-10882(1).) * To avoid race conditions like symlink attacks and issues with temporary files and directories, it is more reliable (and also faster) to manipulate file descriptors instead of file names. Python 3.3 enhances existing functions and introduces new functions to work on file descriptors (bpo-4761(2), bpo-10755(3) and bpo-14626(4)). - The *note os: c4. module has a new *note fwalk(): 3b4. function similar to *note walk(): 654. except that it also yields file descriptors referring to the directories visited. This is especially useful to avoid symlink races. - The following functions get new optional `dir_fd' (*note paths relative to directory descriptors: a2f.) and/or `follow_symlinks' (*note not following symlinks: a30.): *note access(): a31, *note chflags(): a32, *note chmod(): a33, *note chown(): a34, *note link(): a35, *note lstat(): 1f2, *note mkdir(): a36, *note mkfifo(): 663, *note mknod(): 664, *note open(): 665, *note readlink(): 1f3, *note remove(): a37, *note rename(): a38, *note replace(): a39, *note rmdir(): a3a, *note stat(): 1f1, *note symlink(): a3b, *note unlink(): a3c, *note utime(): a3d. Platform support for using these parameters can be checked via the sets *note os.supports_dir_fd: a3e. and ‘os.supports_follows_symlinks’. - The following functions now support a file descriptor for their path argument: *note chdir(): a3f, *note chmod(): a33, *note chown(): a34, *note execve(): a40, *note listdir(): a41, *note pathconf(): a42, *note exists(): 1f6, *note stat(): 1f1, *note statvfs(): a43, *note utime(): a3d. Platform support for this can be checked via the *note os.supports_fd: a44. set. * *note access(): a31. accepts an ‘effective_ids’ keyword argument to turn on using the effective uid/gid rather than the real uid/gid in the access check. Platform support for this can be checked via the *note supports_effective_ids: a45. set. * The *note os: c4. module has two new functions: *note getpriority(): a46. and *note setpriority(): a47. They can be used to get or set process niceness/priority in a fashion similar to *note os.nice(): a48. but extended to all processes instead of just the current one. (Patch submitted by Giampaolo Rodolà in bpo-10784(5).) * The new *note os.replace(): a39. function allows cross-platform renaming of a file with overwriting the destination. With *note os.rename(): a38, an existing destination file is overwritten under POSIX, but raises an error under Windows. (Contributed by Antoine Pitrou in bpo-8828(6).) * The stat family of functions (*note stat(): 1f1, *note fstat(): 65f, and *note lstat(): 1f2.) now support reading a file’s timestamps with nanosecond precision. Symmetrically, *note utime(): a3d. can now write file timestamps with nanosecond precision. (Contributed by Larry Hastings in bpo-14127(7).) * The new *note os.get_terminal_size(): a49. function queries the size of the terminal attached to a file descriptor. See also *note shutil.get_terminal_size(): a4a. (Contributed by Zbigniew Jędrzejewski-Szmek in bpo-13609(8).) * New functions to support Linux extended attributes (bpo-12720(9)): *note getxattr(): a4b, *note listxattr(): a4c, *note removexattr(): a4d, *note setxattr(): a4e. * New interface to the scheduler. These functions control how a process is allocated CPU time by the operating system. New functions: *note sched_get_priority_max(): a4f, *note sched_get_priority_min(): a50, *note sched_getaffinity(): a51, *note sched_getparam(): a52, *note sched_getscheduler(): a53, *note sched_rr_get_interval(): a54, *note sched_setaffinity(): a55, *note sched_setparam(): a56, *note sched_setscheduler(): a57, *note sched_yield(): a58, * New functions to control the file system: * *note posix_fadvise(): 666.: Announces an intention to access data in a specific pattern thus allowing the kernel to make optimizations. * *note posix_fallocate(): 667.: Ensures that enough disk space is allocated for a file. * *note sync(): a59.: Force write of everything to disk. * Additional new posix functions: * *note lockf(): a5a.: Apply, test or remove a POSIX lock on an open file descriptor. * *note pread(): 3b9.: Read from a file descriptor at an offset, the file offset remains unchanged. * *note pwrite(): 3bc.: Write to a file descriptor from an offset, leaving the file offset unchanged. * *note readv(): 3b8.: Read from a file descriptor into a number of writable buffers. * *note truncate(): 724.: Truncate the file corresponding to `path', so that it is at most `length' bytes in size. * *note waitid(): 66c.: Wait for the completion of one or more child processes. * *note writev(): 3bb.: Write the contents of `buffers' to a file descriptor, where `buffers' is an arbitrary sequence of buffers. * *note getgrouplist(): a5b. (bpo-9344(10)): Return list of group ids that specified user belongs to. * *note times(): a5c. and *note uname(): a5d.: Return type changed from a tuple to a tuple-like object with named attributes. * Some platforms now support additional constants for the *note lseek(): a5e. function, such as ‘os.SEEK_HOLE’ and ‘os.SEEK_DATA’. * New constants *note RTLD_LAZY: a5f, *note RTLD_NOW: a60, *note RTLD_GLOBAL: a61, *note RTLD_LOCAL: a62, *note RTLD_NODELETE: a63, *note RTLD_NOLOAD: a64, and *note RTLD_DEEPBIND: a65. are available on platforms that support them. These are for use with the *note sys.setdlopenflags(): a66. function, and supersede the similar constants defined in *note ctypes: 2b. and ‘DLFCN’. (Contributed by Victor Stinner in bpo-13226(11).) * *note os.symlink(): a3b. now accepts (and ignores) the ‘target_is_directory’ keyword argument on non-Windows platforms, to ease cross-platform support. ---------- Footnotes ---------- (1) https://bugs.python.org/issue10882 (2) https://bugs.python.org/issue4761 (3) https://bugs.python.org/issue10755 (4) https://bugs.python.org/issue14626 (5) https://bugs.python.org/issue10784 (6) https://bugs.python.org/issue8828 (7) https://bugs.python.org/issue14127 (8) https://bugs.python.org/issue13609 (9) https://bugs.python.org/issue12720 (10) https://bugs.python.org/issue9344 (11) https://bugs.python.org/issue13226  File: python.info, Node: pdb<4>, Next: pickle<5>, Prev: os<7>, Up: Improved Modules<6> 1.6.20.35 pdb ............. Tab-completion is now available not only for command names, but also their arguments. For example, for the ‘break’ command, function and file names are completed. (Contributed by Georg Brandl in bpo-14210(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14210  File: python.info, Node: pickle<5>, Next: pydoc<4>, Prev: pdb<4>, Up: Improved Modules<6> 1.6.20.36 pickle ................ *note pickle.Pickler: 20d. objects now have an optional *note dispatch_table: a69. attribute allowing per-pickler reduction functions to be set. (Contributed by Richard Oudkerk in bpo-14166(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14166  File: python.info, Node: pydoc<4>, Next: re<6>, Prev: pickle<5>, Up: Improved Modules<6> 1.6.20.37 pydoc ............... The Tk GUI and the ‘serve()’ function have been removed from the *note pydoc: d9. module: ‘pydoc -g’ and ‘serve()’ have been deprecated in Python 3.2.  File: python.info, Node: re<6>, Next: sched, Prev: pydoc<4>, Up: Improved Modules<6> 1.6.20.38 re ............ *note str: 330. regular expressions now support ‘\u’ and ‘\U’ escapes. (Contributed by Serhiy Storchaka in bpo-3665(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue3665  File: python.info, Node: sched, Next: select<2>, Prev: re<6>, Up: Improved Modules<6> 1.6.20.39 sched ............... * *note run(): a6d. now accepts a `blocking' parameter which when set to false makes the method execute the scheduled events due to expire soonest (if any) and then return immediately. This is useful in case you want to use the *note scheduler: a6e. in non-blocking applications. (Contributed by Giampaolo Rodolà in bpo-13449(1).) * *note scheduler: a6e. class can now be safely used in multi-threaded environments. (Contributed by Josiah Carlson and Giampaolo Rodolà in bpo-8684(2).) * `timefunc' and `delayfunct' parameters of *note scheduler: a6e. class constructor are now optional and defaults to *note time.time(): 31d. and *note time.sleep(): 680. respectively. (Contributed by Chris Clark in bpo-13245(3).) * *note enter(): a6f. and *note enterabs(): a70. `argument' parameter is now optional. (Contributed by Chris Clark in bpo-13245(4).) * *note enter(): a6f. and *note enterabs(): a70. now accept a `kwargs' parameter. (Contributed by Chris Clark in bpo-13245(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13449 (2) https://bugs.python.org/issue8684 (3) https://bugs.python.org/issue13245 (4) https://bugs.python.org/issue13245 (5) https://bugs.python.org/issue13245  File: python.info, Node: select<2>, Next: shlex<3>, Prev: sched, Up: Improved Modules<6> 1.6.20.40 select ................ Solaris and derivative platforms have a new class *note select.devpoll: 8ab. for high performance asynchronous sockets via ‘/dev/poll’. (Contributed by Jesús Cea Avión in bpo-6397(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6397  File: python.info, Node: shlex<3>, Next: shutil<4>, Prev: select<2>, Up: Improved Modules<6> 1.6.20.41 shlex ............... The previously undocumented helper function ‘quote’ from the *note pipes: cc. modules has been moved to the *note shlex: e8. module and documented. *note quote(): a73. properly escapes all characters in a string that might be otherwise given special meaning by the shell.  File: python.info, Node: shutil<4>, Next: signal<3>, Prev: shlex<3>, Up: Improved Modules<6> 1.6.20.42 shutil ................ * New functions: * *note disk_usage(): a75.: provides total, used and free disk space statistics. (Contributed by Giampaolo Rodolà in bpo-12442(1).) * *note chown(): a76.: allows one to change user and/or group of the given path also specifying the user/group names and not only their numeric ids. (Contributed by Sandro Tosi in bpo-12191(2).) * *note shutil.get_terminal_size(): a4a.: returns the size of the terminal window to which the interpreter is attached. (Contributed by Zbigniew Jędrzejewski-Szmek in bpo-13609(3).) * *note copy2(): 25a. and *note copystat(): a77. now preserve file timestamps with nanosecond precision on platforms that support it. They also preserve file “extended attributes” on Linux. (Contributed by Larry Hastings in bpo-14127(4) and bpo-15238(5).) * Several functions now take an optional ‘symlinks’ argument: when that parameter is true, symlinks aren’t dereferenced and the operation instead acts on the symlink itself (or creates one, if relevant). (Contributed by Hynek Schlawack in bpo-12715(6).) * When copying files to a different file system, *note move(): 25b. now handles symlinks the way the posix ‘mv’ command does, recreating the symlink rather than copying the target file contents. (Contributed by Jonathan Niehof in bpo-9993(7).) *note move(): 25b. now also returns the ‘dst’ argument as its result. * *note rmtree(): 21c. is now resistant to symlink attacks on platforms which support the new ‘dir_fd’ parameter in *note os.open(): 665. and *note os.unlink(): a3c. (Contributed by Martin von Löwis and Hynek Schlawack in bpo-4489(8).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12442 (2) https://bugs.python.org/issue12191 (3) https://bugs.python.org/issue13609 (4) https://bugs.python.org/issue14127 (5) https://bugs.python.org/issue15238 (6) https://bugs.python.org/issue12715 (7) https://bugs.python.org/issue9993 (8) https://bugs.python.org/issue4489  File: python.info, Node: signal<3>, Next: smtpd<3>, Prev: shutil<4>, Up: Improved Modules<6> 1.6.20.43 signal ................ * The *note signal: ea. module has new functions: * *note pthread_sigmask(): a79.: fetch and/or change the signal mask of the calling thread (Contributed by Jean-Paul Calderone in bpo-8407(1)); * *note pthread_kill(): a7a.: send a signal to a thread; * *note sigpending(): a7b.: examine pending functions; * *note sigwait(): a7c.: wait a signal; * *note sigwaitinfo(): 67f.: wait for a signal, returning detailed information about it; * *note sigtimedwait(): 67e.: like *note sigwaitinfo(): 67f. but with a timeout. * The signal handler writes the signal number as a single byte instead of a nul byte into the wakeup file descriptor. So it is possible to wait more than one signal and know which signals were raised. * *note signal.signal(): a7d. and *note signal.siginterrupt(): a7e. raise an OSError, instead of a RuntimeError: OSError has an errno attribute. ---------- Footnotes ---------- (1) https://bugs.python.org/issue8407  File: python.info, Node: smtpd<3>, Next: smtplib<3>, Prev: signal<3>, Up: Improved Modules<6> 1.6.20.44 smtpd ............... The *note smtpd: ec. module now supports RFC 5321(1) (extended SMTP) and RFC 1870(2) (size extension). Per the standard, these extensions are enabled if and only if the client initiates the session with an ‘EHLO’ command. (Initial ‘ELHO’ support by Alberto Trevino. Size extension by Juhana Jauhiainen. Substantial additional work on the patch contributed by Michele Orrù and Dan Boswell. bpo-8739(3)) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc5321.html (2) https://tools.ietf.org/html/rfc1870.html (3) https://bugs.python.org/issue8739  File: python.info, Node: smtplib<3>, Next: socket<7>, Prev: smtpd<3>, Up: Improved Modules<6> 1.6.20.45 smtplib ................. The *note SMTP: a81, *note SMTP_SSL: a82, and *note LMTP: a83. classes now accept a ‘source_address’ keyword argument to specify the ‘(host, port)’ to use as the source address in the bind call when creating the outgoing socket. (Contributed by Paulo Scardine in bpo-11281(1).) *note SMTP: a81. now supports the context management protocol, allowing an ‘SMTP’ instance to be used in a ‘with’ statement. (Contributed by Giampaolo Rodolà in bpo-11289(2).) The *note SMTP_SSL: a82. constructor and the *note starttls(): a84. method now accept an SSLContext parameter to control parameters of the secure channel. (Contributed by Kasun Herath in bpo-8809(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11281 (2) https://bugs.python.org/issue11289 (3) https://bugs.python.org/issue8809  File: python.info, Node: socket<7>, Next: socketserver<3>, Prev: smtplib<3>, Up: Improved Modules<6> 1.6.20.46 socket ................ * The *note socket: 674. class now exposes additional methods to process ancillary data when supported by the underlying platform: * *note sendmsg(): 67c. * *note recvmsg(): 679. * *note recvmsg_into(): a86. (Contributed by David Watson in bpo-6560(1), based on an earlier patch by Heiko Wundram) * The *note socket: 674. class now supports the PF_CAN protocol family (‘https://en.wikipedia.org/wiki/Socketcan’), on Linux (‘https://lwn.net/Articles/253425’). (Contributed by Matthias Fuchs, updated by Tiago Gonçalves in bpo-10141(2).) * The *note socket: 674. class now supports the PF_RDS protocol family (‘https://en.wikipedia.org/wiki/Reliable_Datagram_Sockets’ and ‘https://oss.oracle.com/projects/rds/’). * The *note socket: 674. class now supports the ‘PF_SYSTEM’ protocol family on OS X. (Contributed by Michael Goderbauer in bpo-13777(3).) * New function *note sethostname(): a87. allows the hostname to be set on unix systems if the calling process has sufficient privileges. (Contributed by Ross Lagerwall in bpo-10866(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6560 (2) https://bugs.python.org/issue10141 (3) https://bugs.python.org/issue13777 (4) https://bugs.python.org/issue10866  File: python.info, Node: socketserver<3>, Next: sqlite3<5>, Prev: socket<7>, Up: Improved Modules<6> 1.6.20.47 socketserver ...................... *note BaseServer: a89. now has an overridable method *note service_actions(): a8a. that is called by the *note serve_forever(): a8b. method in the service loop. *note ForkingMixIn: 3d5. now uses this to clean up zombie child processes. (Contributed by Justin Warkentin in bpo-11109(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11109  File: python.info, Node: sqlite3<5>, Next: ssl<8>, Prev: socketserver<3>, Up: Improved Modules<6> 1.6.20.48 sqlite3 ................. New *note sqlite3.Connection: 3d8. method *note set_trace_callback(): a8d. can be used to capture a trace of all sql commands processed by sqlite. (Contributed by Torsten Landschoff in bpo-11688(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue11688  File: python.info, Node: ssl<8>, Next: stat<2>, Prev: sqlite3<5>, Up: Improved Modules<6> 1.6.20.49 ssl ............. * The *note ssl: f3. module has two new random generation functions: * *note RAND_bytes(): a8f.: generate cryptographically strong pseudo-random bytes. * *note RAND_pseudo_bytes(): a90.: generate pseudo-random bytes. (Contributed by Victor Stinner in bpo-12049(1).) * The *note ssl: f3. module now exposes a finer-grained exception hierarchy in order to make it easier to inspect the various kinds of errors. (Contributed by Antoine Pitrou in bpo-11183(2).) * *note load_cert_chain(): a91. now accepts a `password' argument to be used if the private key is encrypted. (Contributed by Adam Simpkins in bpo-12803(3).) * Diffie-Hellman key exchange, both regular and Elliptic Curve-based, is now supported through the *note load_dh_params(): a92. and *note set_ecdh_curve(): a93. methods. (Contributed by Antoine Pitrou in bpo-13626(4) and bpo-13627(5).) * SSL sockets have a new *note get_channel_binding(): a94. method allowing the implementation of certain authentication mechanisms such as SCRAM-SHA-1-PLUS. (Contributed by Jacek Konieczny in bpo-12551(6).) * You can query the SSL compression algorithm used by an SSL socket, thanks to its new *note compression(): a95. method. The new attribute *note OP_NO_COMPRESSION: a96. can be used to disable compression. (Contributed by Antoine Pitrou in bpo-13634(7).) * Support has been added for the Next Protocol Negotiation extension using the *note ssl.SSLContext.set_npn_protocols(): a97. method. (Contributed by Colin Marc in bpo-14204(8).) * SSL errors can now be introspected more easily thanks to *note library: a98. and *note reason: a99. attributes. (Contributed by Antoine Pitrou in bpo-14837(9).) * The *note get_server_certificate(): a9a. function now supports IPv6. (Contributed by Charles-François Natali in bpo-11811(10).) * New attribute *note OP_CIPHER_SERVER_PREFERENCE: a9b. allows setting SSLv3 server sockets to use the server’s cipher ordering preference rather than the client’s (bpo-13635(11)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue12049 (2) https://bugs.python.org/issue11183 (3) https://bugs.python.org/issue12803 (4) https://bugs.python.org/issue13626 (5) https://bugs.python.org/issue13627 (6) https://bugs.python.org/issue12551 (7) https://bugs.python.org/issue13634 (8) https://bugs.python.org/issue14204 (9) https://bugs.python.org/issue14837 (10) https://bugs.python.org/issue11811 (11) https://bugs.python.org/issue13635  File: python.info, Node: stat<2>, Next: struct<3>, Prev: ssl<8>, Up: Improved Modules<6> 1.6.20.50 stat .............. The undocumented tarfile.filemode function has been moved to *note stat.filemode(): a9d. It can be used to convert a file’s mode to a string of the form ‘-rwxrwxrwx’. (Contributed by Giampaolo Rodolà in bpo-14807(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14807  File: python.info, Node: struct<3>, Next: subprocess<5>, Prev: stat<2>, Up: Improved Modules<6> 1.6.20.51 struct ................ The *note struct: f8. module now supports ‘ssize_t’ and ‘size_t’ via the new codes ‘n’ and ‘N’, respectively. (Contributed by Antoine Pitrou in bpo-3163(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue3163  File: python.info, Node: subprocess<5>, Next: sys<7>, Prev: struct<3>, Up: Improved Modules<6> 1.6.20.52 subprocess .................... Command strings can now be bytes objects on posix platforms. (Contributed by Victor Stinner in bpo-8513(1).) A new constant *note DEVNULL: aa0. allows suppressing output in a platform-independent fashion. (Contributed by Ross Lagerwall in bpo-5870(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8513 (2) https://bugs.python.org/issue5870  File: python.info, Node: sys<7>, Next: tarfile<4>, Prev: subprocess<5>, Up: Improved Modules<6> 1.6.20.53 sys ............. The *note sys: fd. module has a new *note thread_info: aa2. *note named tuple: aa3. holding information about the thread implementation (bpo-11223(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue11223  File: python.info, Node: tarfile<4>, Next: tempfile, Prev: sys<7>, Up: Improved Modules<6> 1.6.20.54 tarfile ................. *note tarfile: 101. now supports ‘lzma’ encoding via the *note lzma: ad. module. (Contributed by Lars Gustäbel in bpo-5689(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5689  File: python.info, Node: tempfile, Next: textwrap<2>, Prev: tarfile<4>, Up: Improved Modules<6> 1.6.20.55 tempfile .................. *note tempfile.SpooledTemporaryFile: aa6.’s ‘truncate()’ method now accepts a ‘size’ parameter. (Contributed by Ryan Kelly in bpo-9957(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9957  File: python.info, Node: textwrap<2>, Next: threading<5>, Prev: tempfile, Up: Improved Modules<6> 1.6.20.56 textwrap .................. The *note textwrap: 108. module has a new *note indent(): aa8. that makes it straightforward to add a common prefix to selected lines in a block of text (bpo-13857(1)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue13857  File: python.info, Node: threading<5>, Next: time<5>, Prev: textwrap<2>, Up: Improved Modules<6> 1.6.20.57 threading ................... *note threading.Condition: aaa, *note threading.Semaphore: aab, *note threading.BoundedSemaphore: aac, *note threading.Event: aad, and *note threading.Timer: aae, all of which used to be factory functions returning a class instance, are now classes and may be subclassed. (Contributed by Éric Araujo in bpo-10968(1).) The *note threading.Thread: 235. constructor now accepts a ‘daemon’ keyword argument to override the default behavior of inheriting the ‘daemon’ flag value from the parent thread (bpo-6064(2)). The formerly private function ‘_thread.get_ident’ is now available as the public function *note threading.get_ident(): aaf. This eliminates several cases of direct access to the ‘_thread’ module in the stdlib. Third party code that used ‘_thread.get_ident’ should likewise be changed to use the new public interface. ---------- Footnotes ---------- (1) https://bugs.python.org/issue10968 (2) https://bugs.python.org/issue6064  File: python.info, Node: time<5>, Next: types<4>, Prev: threading<5>, Up: Improved Modules<6> 1.6.20.58 time .............. The PEP 418(1) added new functions to the *note time: 10a. module: * *note get_clock_info(): ab1.: Get information on a clock. * *note monotonic(): 76f.: Monotonic clock (cannot go backward), not affected by system clock updates. * *note perf_counter(): 2aa.: Performance counter with the highest available resolution to measure a short duration. * *note process_time(): 2ab.: Sum of the system and user CPU time of the current process. Other new functions: * *note clock_getres(): ab2, *note clock_gettime(): ab3. and *note clock_settime(): ab4. functions with ‘CLOCK_xxx’ constants. (Contributed by Victor Stinner in bpo-10278(2).) To improve cross platform consistency, *note sleep(): 680. now raises a *note ValueError: 1fb. when passed a negative sleep value. Previously this was an error on posix, but produced an infinite sleep on Windows. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0418 (2) https://bugs.python.org/issue10278  File: python.info, Node: types<4>, Next: unittest<5>, Prev: time<5>, Up: Improved Modules<6> 1.6.20.59 types ............... Add a new *note types.MappingProxyType: ab6. class: Read-only proxy of a mapping. (bpo-14386(1)) The new functions *note types.new_class(): ab7. and *note types.prepare_class(): ab8. provide support for PEP 3115(2) compliant dynamic type creation. (bpo-14588(3)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14386 (2) https://www.python.org/dev/peps/pep-3115 (3) https://bugs.python.org/issue14588  File: python.info, Node: unittest<5>, Next: urllib<3>, Prev: types<4>, Up: Improved Modules<6> 1.6.20.60 unittest .................. *note assertRaises(): aba, *note assertRaisesRegex(): abb, *note assertWarns(): abc, and *note assertWarnsRegex(): abd. now accept a keyword argument `msg' when used as context managers. (Contributed by Ezio Melotti and Winston Ewert in bpo-10775(1).) *note unittest.TestCase.run(): abe. now returns the *note TestResult: abf. object. ---------- Footnotes ---------- (1) https://bugs.python.org/issue10775  File: python.info, Node: urllib<3>, Next: webbrowser, Prev: unittest<5>, Up: Improved Modules<6> 1.6.20.61 urllib ................ The *note Request: 8f6. class, now accepts a `method' argument used by *note get_method(): ac1. to determine what HTTP method should be used. For example, this will send a ‘'HEAD'’ request: >>> urlopen(Request('https://www.python.org', method='HEAD')) (bpo-1673007(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1673007  File: python.info, Node: webbrowser, Next: xml etree ElementTree, Prev: urllib<3>, Up: Improved Modules<6> 1.6.20.62 webbrowser .................... The *note webbrowser: 129. module supports more “browsers”: Google Chrome (named ‘chrome’, ‘chromium’, ‘chrome-browser’ or ‘chromium-browser’ depending on the version and operating system), and the generic launchers ‘xdg-open’, from the FreeDesktop.org project, and ‘gvfs-open’, which is the default URI handler for GNOME 3. (The former contributed by Arnaud Calmettes in bpo-13620(1), the latter by Matthias Klose in bpo-14493(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue13620 (2) https://bugs.python.org/issue14493  File: python.info, Node: xml etree ElementTree, Next: zlib<2>, Prev: webbrowser, Up: Improved Modules<6> 1.6.20.63 xml.etree.ElementTree ............................... The *note xml.etree.ElementTree: 137. module now imports its C accelerator by default; there is no longer a need to explicitly import ‘xml.etree.cElementTree’ (this module stays for backwards compatibility, but is now deprecated). In addition, the ‘iter’ family of methods of *note Element: ac4. has been optimized (rewritten in C). The module’s documentation has also been greatly improved with added examples and a more detailed reference.  File: python.info, Node: zlib<2>, Prev: xml etree ElementTree, Up: Improved Modules<6> 1.6.20.64 zlib .............. New attribute *note zlib.Decompress.eof: ac6. makes it possible to distinguish between a properly-formed compressed stream and an incomplete or truncated one. (Contributed by Nadeem Vawda in bpo-12646(1).) New attribute *note zlib.ZLIB_RUNTIME_VERSION: ac7. reports the version string of the underlying ‘zlib’ library that is loaded at runtime. (Contributed by Torsten Landschoff in bpo-12306(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue12646 (2) https://bugs.python.org/issue12306  File: python.info, Node: Optimizations<5>, Next: Build and C API Changes<4>, Prev: Improved Modules<6>, Up: What’s New In Python 3 3 1.6.21 Optimizations -------------------- Major performance enhancements have been added: * Thanks to PEP 393(1), some operations on Unicode strings have been optimized: * the memory footprint is divided by 2 to 4 depending on the text * encode an ASCII string to UTF-8 doesn’t need to encode characters anymore, the UTF-8 representation is shared with the ASCII representation * the UTF-8 encoder has been optimized * repeating a single ASCII letter and getting a substring of an ASCII string is 4 times faster * UTF-8 is now 2x to 4x faster. UTF-16 encoding is now up to 10x faster. (Contributed by Serhiy Storchaka, bpo-14624(2), bpo-14738(3) and bpo-15026(4).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393 (2) https://bugs.python.org/issue14624 (3) https://bugs.python.org/issue14738 (4) https://bugs.python.org/issue15026  File: python.info, Node: Build and C API Changes<4>, Next: Deprecated<5>, Prev: Optimizations<5>, Up: What’s New In Python 3 3 1.6.22 Build and C API Changes ------------------------------ Changes to Python’s build process and to the C API include: * New PEP 3118(1) related function: * *note PyMemoryView_FromMemory(): ac9. * PEP 393(2) added new Unicode types, macros and functions: * High-level API: * *note PyUnicode_CopyCharacters(): aca. * *note PyUnicode_FindChar(): 440. * *note PyUnicode_GetLength(): acb, *note PyUnicode_GET_LENGTH: acc. * *note PyUnicode_New(): acd. * *note PyUnicode_Substring(): ace. * *note PyUnicode_ReadChar(): acf, *note PyUnicode_WriteChar(): ad0. * Low-level API: * *note Py_UCS1: ad1, *note Py_UCS2: ad2, *note Py_UCS4: ad3. types * *note PyASCIIObject: ad4. and *note PyCompactUnicodeObject: ad5. structures * *note PyUnicode_READY: ad6. * *note PyUnicode_FromKindAndData(): ad7. * *note PyUnicode_AsUCS4(): ad8, *note PyUnicode_AsUCS4Copy(): ad9. * *note PyUnicode_DATA: ada, *note PyUnicode_1BYTE_DATA: adb, *note PyUnicode_2BYTE_DATA: adc, *note PyUnicode_4BYTE_DATA: add. * *note PyUnicode_KIND: ade. with ‘PyUnicode_Kind’ enum: *note PyUnicode_WCHAR_KIND: adf, *note PyUnicode_1BYTE_KIND: ae0, *note PyUnicode_2BYTE_KIND: ae1, *note PyUnicode_4BYTE_KIND: ae2. * *note PyUnicode_READ: ae3, *note PyUnicode_READ_CHAR: ae4, *note PyUnicode_WRITE: ae5. * *note PyUnicode_MAX_CHAR_VALUE: ae6. * *note PyArg_ParseTuple: 26a. now accepts a *note bytearray: 332. for the ‘c’ format (bpo-12380(3)). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3118 (2) https://www.python.org/dev/peps/pep-0393 (3) https://bugs.python.org/issue12380  File: python.info, Node: Deprecated<5>, Next: Porting to Python 3 3, Prev: Build and C API Changes<4>, Up: What’s New In Python 3 3 1.6.23 Deprecated ----------------- * Menu: * Unsupported Operating Systems: Unsupported Operating Systems<2>. * Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<4>. * Deprecated functions and types of the C API: Deprecated functions and types of the C API<3>. * Deprecated features::  File: python.info, Node: Unsupported Operating Systems<2>, Next: Deprecated Python modules functions and methods<4>, Up: Deprecated<5> 1.6.23.1 Unsupported Operating Systems ...................................... OS/2 and VMS are no longer supported due to the lack of a maintainer. Windows 2000 and Windows platforms which set ‘COMSPEC’ to ‘command.com’ are no longer supported due to maintenance burden. OSF support, which was deprecated in 3.2, has been completely removed.  File: python.info, Node: Deprecated Python modules functions and methods<4>, Next: Deprecated functions and types of the C API<3>, Prev: Unsupported Operating Systems<2>, Up: Deprecated<5> 1.6.23.2 Deprecated Python modules, functions and methods ......................................................... * Passing a non-empty string to ‘object.__format__()’ is deprecated, and will produce a *note TypeError: 192. in Python 3.4 (bpo-9856(1)). * The ‘unicode_internal’ codec has been deprecated because of the PEP 393(2), use UTF-8, UTF-16 (‘utf-16-le’ or ‘utf-16-be’), or UTF-32 (‘utf-32-le’ or ‘utf-32-be’) * *note ftplib.FTP.nlst(): a06. and *note ftplib.FTP.dir(): a07.: use *note ftplib.FTP.mlsd(): a05. * ‘platform.popen()’: use the *note subprocess: f9. module. Check especially the *note Replacing Older Functions with the subprocess Module: aea. section (bpo-11377(3)). * bpo-13374(4): The Windows bytes API has been deprecated in the *note os: c4. module. Use Unicode filenames, instead of bytes filenames, to not depend on the ANSI code page anymore and to support any filename. * bpo-13988(5): The ‘xml.etree.cElementTree’ module is deprecated. The accelerator is used automatically whenever available. * The behaviour of ‘time.clock()’ depends on the platform: use the new *note time.perf_counter(): 2aa. or *note time.process_time(): 2ab. function instead, depending on your requirements, to have a well defined behaviour. * The ‘os.stat_float_times()’ function is deprecated. * *note abc: 4. module: * *note abc.abstractproperty: 9cd. has been deprecated, use *note property: 1d7. with *note abc.abstractmethod(): 9ce. instead. * *note abc.abstractclassmethod: 9cf. has been deprecated, use *note classmethod: 1d8. with *note abc.abstractmethod(): 9ce. instead. * *note abc.abstractstaticmethod: 9d0. has been deprecated, use *note staticmethod: 1d9. with *note abc.abstractmethod(): 9ce. instead. * *note importlib: 9b. package: * *note importlib.abc.SourceLoader.path_mtime(): aeb. is now deprecated in favour of *note importlib.abc.SourceLoader.path_stats(): aec. as bytecode files now store both the modification time and size of the source file the bytecode file was compiled from. ---------- Footnotes ---------- (1) https://bugs.python.org/issue9856 (2) https://www.python.org/dev/peps/pep-0393 (3) https://bugs.python.org/issue11377 (4) https://bugs.python.org/issue13374 (5) https://bugs.python.org/issue13988  File: python.info, Node: Deprecated functions and types of the C API<3>, Next: Deprecated features, Prev: Deprecated Python modules functions and methods<4>, Up: Deprecated<5> 1.6.23.3 Deprecated functions and types of the C API .................................................... The *note Py_UNICODE: aee. has been deprecated by PEP 393(1) and will be removed in Python 4. All functions using this type are deprecated: Unicode functions and methods using *note Py_UNICODE: aee. and *note Py_UNICODE*: aee. types: * *note PyUnicode_FromUnicode: aef.: use *note PyUnicode_FromWideChar(): af0. or *note PyUnicode_FromKindAndData(): ad7. * *note PyUnicode_AS_UNICODE: af1, *note PyUnicode_AsUnicode(): af2, *note PyUnicode_AsUnicodeAndSize(): af3.: use *note PyUnicode_AsWideCharString(): 438. * *note PyUnicode_AS_DATA: af4.: use *note PyUnicode_DATA: ada. with *note PyUnicode_READ: ae3. and *note PyUnicode_WRITE: ae5. * *note PyUnicode_GET_SIZE: af5, *note PyUnicode_GetSize(): af6.: use *note PyUnicode_GET_LENGTH: acc. or *note PyUnicode_GetLength(): acb. * *note PyUnicode_GET_DATA_SIZE: af7.: use ‘PyUnicode_GET_LENGTH(str) * PyUnicode_KIND(str)’ (only work on ready strings) * *note PyUnicode_AsUnicodeCopy(): af8.: use *note PyUnicode_AsUCS4Copy(): ad9. or *note PyUnicode_AsWideCharString(): 438. * ‘PyUnicode_GetMax()’ Functions and macros manipulating Py_UNICODE* strings: * ‘Py_UNICODE_strlen’: use *note PyUnicode_GetLength(): acb. or *note PyUnicode_GET_LENGTH: acc. * ‘Py_UNICODE_strcat’: use *note PyUnicode_CopyCharacters(): aca. or *note PyUnicode_FromFormat(): 7cb. * ‘Py_UNICODE_strcpy’, ‘Py_UNICODE_strncpy’, ‘Py_UNICODE_COPY’: use *note PyUnicode_CopyCharacters(): aca. or *note PyUnicode_Substring(): ace. * ‘Py_UNICODE_strcmp’: use *note PyUnicode_Compare(): af9. * ‘Py_UNICODE_strncmp’: use *note PyUnicode_Tailmatch(): afa. * ‘Py_UNICODE_strchr’, ‘Py_UNICODE_strrchr’: use *note PyUnicode_FindChar(): 440. * ‘Py_UNICODE_FILL’: use *note PyUnicode_Fill(): afb. * ‘Py_UNICODE_MATCH’ Encoders: * *note PyUnicode_Encode(): afc.: use ‘PyUnicode_AsEncodedObject()’ * *note PyUnicode_EncodeUTF7(): afd. * *note PyUnicode_EncodeUTF8(): afe.: use *note PyUnicode_AsUTF8(): 42b. or *note PyUnicode_AsUTF8String(): aff. * *note PyUnicode_EncodeUTF32(): b00. * *note PyUnicode_EncodeUTF16(): b01. * *note PyUnicode_EncodeUnicodeEscape(): b02. use *note PyUnicode_AsUnicodeEscapeString(): b03. * *note PyUnicode_EncodeRawUnicodeEscape(): b04. use *note PyUnicode_AsRawUnicodeEscapeString(): b05. * *note PyUnicode_EncodeLatin1(): b06.: use *note PyUnicode_AsLatin1String(): b07. * *note PyUnicode_EncodeASCII(): b08.: use *note PyUnicode_AsASCIIString(): b09. * *note PyUnicode_EncodeCharmap(): b0a. * *note PyUnicode_TranslateCharmap(): b0b. * *note PyUnicode_EncodeMBCS(): b0c.: use *note PyUnicode_AsMBCSString(): b0d. or *note PyUnicode_EncodeCodePage(): b0e. (with ‘CP_ACP’ code_page) * ‘PyUnicode_EncodeDecimal()’, *note PyUnicode_TransformDecimalToASCII(): b0f. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393  File: python.info, Node: Deprecated features, Prev: Deprecated functions and types of the C API<3>, Up: Deprecated<5> 1.6.23.4 Deprecated features ............................ The *note array: 7. module’s ‘'u'’ format code is now deprecated and will be removed in Python 4 together with the rest of the (*note Py_UNICODE: aee.) API.  File: python.info, Node: Porting to Python 3 3, Prev: Deprecated<5>, Up: What’s New In Python 3 3 1.6.24 Porting to Python 3.3 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code. * Menu: * Porting Python code:: * Porting C code:: * Building C extensions:: * Command Line Switch Changes::  File: python.info, Node: Porting Python code, Next: Porting C code, Up: Porting to Python 3 3 1.6.24.1 Porting Python code ............................ * Hash randomization is enabled by default. Set the *note PYTHONHASHSEED: 9c5. environment variable to ‘0’ to disable hash randomization. See also the *note object.__hash__(): 340. method. * bpo-12326(1): On Linux, sys.platform doesn’t contain the major version anymore. It is now always ‘linux’, instead of ‘linux2’ or ‘linux3’ depending on the Linux version used to build Python. Replace sys.platform == ‘linux2’ with sys.platform.startswith(‘linux’), or directly sys.platform == ‘linux’ if you don’t need to support older Python versions. * bpo-13847(2), bpo-14180(3): *note time: 10a. and *note datetime: 31.: *note OverflowError: 960. is now raised instead of *note ValueError: 1fb. if a timestamp is out of range. *note OSError: 1d3. is now raised if C functions ‘gmtime()’ or ‘localtime()’ failed. * The default finders used by import now utilize a cache of what is contained within a specific directory. If you create a Python source file or sourceless bytecode file, make sure to call *note importlib.invalidate_caches(): 49c. to clear out the cache for the finders to notice the new file. * *note ImportError: 334. now uses the full name of the module that was attempted to be imported. Doctests that check ImportErrors’ message will need to be updated to use the full name of the module instead of just the tail of the name. * The `index' argument to *note __import__(): 610. now defaults to 0 instead of -1 and no longer support negative values. It was an oversight when PEP 328(4) was implemented that the default value remained -1. If you need to continue to perform a relative import followed by an absolute import, then perform the relative import using an index of 1, followed by another import using an index of 0. It is preferred, though, that you use *note importlib.import_module(): b13. rather than call *note __import__(): 610. directly. * *note __import__(): 610. no longer allows one to use an index value other than 0 for top-level modules. E.g. ‘__import__('sys', level=1)’ is now an error. * Because *note sys.meta_path: 5e6. and *note sys.path_hooks: 95c. now have finders on them by default, you will most likely want to use ‘list.insert()’ instead of ‘list.append()’ to add to those lists. * Because ‘None’ is now inserted into *note sys.path_importer_cache: 49d, if you are clearing out entries in the dictionary of paths that do not have a finder, you will need to remove keys paired with values of ‘None’ `and' *note imp.NullImporter: 9bb. to be backwards-compatible. This will lead to extra overhead on older versions of Python that re-insert ‘None’ into *note sys.path_importer_cache: 49d. where it represents the use of implicit finders, but semantically it should not change anything. * *note importlib.abc.Finder: 9b5. no longer specifies a ‘find_module()’ abstract method that must be implemented. If you were relying on subclasses to implement that method, make sure to check for the method’s existence first. You will probably want to check for ‘find_loader()’ first, though, in the case of working with *note path entry finders: 9b2. * *note pkgutil: cd. has been converted to use *note importlib: 9b. internally. This eliminates many edge cases where the old behaviour of the PEP 302(5) import emulation failed to match the behaviour of the real import system. The import emulation itself is still present, but is now deprecated. The *note pkgutil.iter_importers(): b14. and *note pkgutil.walk_packages(): 48b. functions special case the standard import hooks so they are still supported even though they do not provide the non-standard ‘iter_modules()’ method. * A longstanding RFC-compliance bug (bpo-1079(6)) in the parsing done by *note email.header.decode_header(): 9f9. has been fixed. Code that uses the standard idiom to convert encoded headers into unicode (‘str(make_header(decode_header(h))’) will see no change, but code that looks at the individual tuples returned by decode_header will see that whitespace that precedes or follows ‘ASCII’ sections is now included in the ‘ASCII’ section. Code that builds headers using ‘make_header’ should also continue to work without change, since ‘make_header’ continues to add whitespace between ‘ASCII’ and non-‘ASCII’ sections if it is not already present in the input strings. * *note email.utils.formataddr(): b15. now does the correct content transfer encoding when passed non-‘ASCII’ display names. Any code that depended on the previous buggy behavior that preserved the non-‘ASCII’ unicode in the formatted output string will need to be changed (bpo-1690608(7)). * *note poplib.POP3.quit(): b16. may now raise protocol errors like all other ‘poplib’ methods. Code that assumes ‘quit’ does not raise *note poplib.error_proto: b17. errors may need to be changed if errors on ‘quit’ are encountered by a particular application (bpo-11291(8)). * The ‘strict’ argument to *note email.parser.Parser: b18, deprecated since Python 2.4, has finally been removed. * The deprecated method ‘unittest.TestCase.assertSameElements’ has been removed. * The deprecated variable ‘time.accept2dyear’ has been removed. * The deprecated ‘Context._clamp’ attribute has been removed from the *note decimal: 36. module. It was previously replaced by the public attribute ‘clamp’. (See bpo-8540(9).) * The undocumented internal helper class ‘SSLFakeFile’ has been removed from *note smtplib: ed, since its functionality has long been provided directly by *note socket.socket.makefile(): b19. * Passing a negative value to *note time.sleep(): 680. on Windows now raises an error instead of sleeping forever. It has always raised an error on posix. * The ‘ast.__version__’ constant has been removed. If you need to make decisions affected by the AST version, use *note sys.version_info: b1a. to make the decision. * Code that used to work around the fact that the *note threading: 109. module used factory functions by subclassing the private classes will need to change to subclass the now-public classes. * The undocumented debugging machinery in the threading module has been removed, simplifying the code. This should have no effect on production code, but is mentioned here in case any application debug frameworks were interacting with it (bpo-13550(10)). ---------- Footnotes ---------- (1) https://bugs.python.org/issue12326 (2) https://bugs.python.org/issue13847 (3) https://bugs.python.org/issue14180 (4) https://www.python.org/dev/peps/pep-0328 (5) https://www.python.org/dev/peps/pep-0302 (6) https://bugs.python.org/issue1079 (7) https://bugs.python.org/issue1690608 (8) https://bugs.python.org/issue11291 (9) https://bugs.python.org/issue8540 (10) https://bugs.python.org/issue13550  File: python.info, Node: Porting C code, Next: Building C extensions, Prev: Porting Python code, Up: Porting to Python 3 3 1.6.24.2 Porting C code ....................... * In the course of changes to the buffer API the undocumented ‘smalltable’ member of the *note Py_buffer: b1b. structure has been removed and the layout of the ‘PyMemoryViewObject’ has changed. All extensions relying on the relevant parts in ‘memoryobject.h’ or ‘object.h’ must be rebuilt. * Due to *note PEP 393: 97c, the *note Py_UNICODE: aee. type and all functions using this type are deprecated (but will stay available for at least five years). If you were using low-level Unicode APIs to construct and access unicode objects and you want to benefit of the memory footprint reduction provided by PEP 393(1), you have to convert your code to the new *note Unicode API: b1c. However, if you only have been using high-level functions such as *note PyUnicode_Concat(): b1d, *note PyUnicode_Join(): b1e. or *note PyUnicode_FromFormat(): 7cb, your code will automatically take advantage of the new unicode representations. * *note PyImport_GetMagicNumber(): b1f. now returns ‘-1’ upon failure. * As a negative value for the `level' argument to *note __import__(): 610. is no longer valid, the same now holds for *note PyImport_ImportModuleLevel(): b20. This also means that the value of `level' used by *note PyImport_ImportModuleEx(): b21. is now ‘0’ instead of ‘-1’. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393  File: python.info, Node: Building C extensions, Next: Command Line Switch Changes, Prev: Porting C code, Up: Porting to Python 3 3 1.6.24.3 Building C extensions .............................. * The range of possible file names for C extensions has been narrowed. Very rarely used spellings have been suppressed: under POSIX, files named ‘xxxmodule.so’, ‘xxxmodule.abi3.so’ and ‘xxxmodule.cpython-*.so’ are no longer recognized as implementing the ‘xxx’ module. If you had been generating such files, you have to switch to the other spellings (i.e., remove the ‘module’ string from the file names). (implemented in bpo-14040(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue14040  File: python.info, Node: Command Line Switch Changes, Prev: Building C extensions, Up: Porting to Python 3 3 1.6.24.4 Command Line Switch Changes .................................... * The -Q command-line flag and related artifacts have been removed. Code checking sys.flags.division_warning will need updating. (bpo-10998(1), contributed by Éric Araujo.) * When ‘python’ is started with *note -S: b24, ‘import site’ will no longer add site-specific paths to the module search paths. In previous versions, it did. (bpo-11591(2), contributed by Carl Meyer with editions by Éric Araujo.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10998 (2) https://bugs.python.org/issue11591  File: python.info, Node: What’s New In Python 3 2, Next: What’s New In Python 3 1, Prev: What’s New In Python 3 3, Up: What’s New in Python 1.7 What’s New In Python 3.2 ============================ Author: Raymond Hettinger This article explains the new features in Python 3.2 as compared to 3.1. It focuses on a few highlights and gives a few examples. For full details, see the Misc/NEWS(1) file. See also ........ PEP 392(2) - Python 3.2 Release Schedule * Menu: * PEP 384; Defining a Stable ABI: PEP 384 Defining a Stable ABI. * PEP 389; Argparse Command Line Parsing Module: PEP 389 Argparse Command Line Parsing Module. * PEP 391; Dictionary Based Configuration for Logging: PEP 391 Dictionary Based Configuration for Logging. * PEP 3148; The concurrent.futures module: PEP 3148 The concurrent futures module. * PEP 3147; PYC Repository Directories: PEP 3147 PYC Repository Directories. * PEP 3149; ABI Version Tagged .so Files: PEP 3149 ABI Version Tagged so Files. * PEP 3333; Python Web Server Gateway Interface v1.0.1: PEP 3333 Python Web Server Gateway Interface v1 0 1. * Other Language Changes: Other Language Changes<7>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules. * Multi-threading:: * Optimizations: Optimizations<6>. * Unicode:: * Codecs:: * Documentation:: * IDLE:: * Code Repository:: * Build and C API Changes: Build and C API Changes<5>. * Porting to Python 3.2: Porting to Python 3 2. ---------- Footnotes ---------- (1) https://github.com/python/cpython/blob/076ca6c3c8df3030307e548d9be792ce3c1c6eea/Misc/NEWS (2) https://www.python.org/dev/peps/pep-0392  File: python.info, Node: PEP 384 Defining a Stable ABI, Next: PEP 389 Argparse Command Line Parsing Module, Up: What’s New In Python 3 2 1.7.1 PEP 384: Defining a Stable ABI ------------------------------------ In the past, extension modules built for one Python version were often not usable with other Python versions. Particularly on Windows, every feature release of Python required rebuilding all extension modules that one wanted to use. This requirement was the result of the free access to Python interpreter internals that extension modules could use. With Python 3.2, an alternative approach becomes available: extension modules which restrict themselves to a limited API (by defining Py_LIMITED_API) cannot use many of the internals, but are constrained to a set of API functions that are promised to be stable for several releases. As a consequence, extension modules built for 3.2 in that mode will also work with 3.3, 3.4, and so on. Extension modules that make use of details of memory structures can still be built, but will need to be recompiled for every feature release. See also ........ PEP 384(1) - Defining a Stable ABI PEP written by Martin von Löwis. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0384  File: python.info, Node: PEP 389 Argparse Command Line Parsing Module, Next: PEP 391 Dictionary Based Configuration for Logging, Prev: PEP 384 Defining a Stable ABI, Up: What’s New In Python 3 2 1.7.2 PEP 389: Argparse Command Line Parsing Module --------------------------------------------------- A new module for command line parsing, *note argparse: 6, was introduced to overcome the limitations of *note optparse: c3. which did not provide support for positional arguments (not just options), subcommands, required options and other common patterns of specifying and validating options. This module has already had widespread success in the community as a third-party module. Being more fully featured than its predecessor, the *note argparse: 6. module is now the preferred module for command-line processing. The older module is still being kept available because of the substantial amount of legacy code that depends on it. Here’s an annotated example parser showing features like limiting results to a set of choices, specifying a `metavar' in the help screen, validating that one or more positional arguments is present, and making a required option: import argparse parser = argparse.ArgumentParser( description = 'Manage servers', # main description for help epilog = 'Tested on Solaris and Linux') # displayed after help parser.add_argument('action', # argument name choices = ['deploy', 'start', 'stop'], # three allowed values help = 'action on each target') # help msg parser.add_argument('targets', metavar = 'HOSTNAME', # var name used in help msg nargs = '+', # require one or more targets help = 'url for target machines') # help msg explanation parser.add_argument('-u', '--user', # -u or --user option required = True, # make it a required argument help = 'login as user') Example of calling the parser on a command string: >>> cmd = 'deploy sneezy.example.com sleepy.example.com -u skycaptain' >>> result = parser.parse_args(cmd.split()) >>> result.action 'deploy' >>> result.targets ['sneezy.example.com', 'sleepy.example.com'] >>> result.user 'skycaptain' Example of the parser’s automatically generated help: >>> parser.parse_args('-h'.split()) usage: manage_cloud.py [-h] -u USER {deploy,start,stop} HOSTNAME [HOSTNAME ...] Manage servers positional arguments: {deploy,start,stop} action on each target HOSTNAME url for target machines optional arguments: -h, --help show this help message and exit -u USER, --user USER login as user Tested on Solaris and Linux An especially nice *note argparse: 6. feature is the ability to define subparsers, each with their own argument patterns and help displays: import argparse parser = argparse.ArgumentParser(prog='HELM') subparsers = parser.add_subparsers() parser_l = subparsers.add_parser('launch', help='Launch Control') # first subgroup parser_l.add_argument('-m', '--missiles', action='store_true') parser_l.add_argument('-t', '--torpedos', action='store_true') parser_m = subparsers.add_parser('move', help='Move Vessel', # second subgroup aliases=('steer', 'turn')) # equivalent names parser_m.add_argument('-c', '--course', type=int, required=True) parser_m.add_argument('-s', '--speed', type=int, default=0) $ ./helm.py --help # top level help (launch and move) $ ./helm.py launch --help # help for launch options $ ./helm.py launch --missiles # set missiles=True and torpedos=False $ ./helm.py steer --course 180 --speed 5 # set movement parameters See also ........ PEP 389(1) - New Command Line Parsing Module PEP written by Steven Bethard. *note Upgrading optparse code: b29. for details on the differences from *note optparse: c3. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0389  File: python.info, Node: PEP 391 Dictionary Based Configuration for Logging, Next: PEP 3148 The concurrent futures module, Prev: PEP 389 Argparse Command Line Parsing Module, Up: What’s New In Python 3 2 1.7.3 PEP 391: Dictionary Based Configuration for Logging --------------------------------------------------------- The *note logging: aa. module provided two kinds of configuration, one style with function calls for each option or another style driven by an external file saved in a ‘ConfigParser’ format. Those options did not provide the flexibility to create configurations from JSON or YAML files, nor did they support incremental configuration, which is needed for specifying logger options from a command line. To support a more flexible style, the module now offers *note logging.config.dictConfig(): b2b. for specifying logging configuration with plain Python dictionaries. The configuration options include formatters, handlers, filters, and loggers. Here’s a working example of a configuration dictionary: {"version": 1, "formatters": {"brief": {"format": "%(levelname)-8s: %(name)-15s: %(message)s"}, "full": {"format": "%(asctime)s %(name)-15s %(levelname)-8s %(message)s"} }, "handlers": {"console": { "class": "logging.StreamHandler", "formatter": "brief", "level": "INFO", "stream": "ext://sys.stdout"}, "console_priority": { "class": "logging.StreamHandler", "formatter": "full", "level": "ERROR", "stream": "ext://sys.stderr"} }, "root": {"level": "DEBUG", "handlers": ["console", "console_priority"]}} If that dictionary is stored in a file called ‘conf.json’, it can be loaded and called with code like this: >>> import json, logging.config >>> with open('conf.json') as f: ... conf = json.load(f) ... >>> logging.config.dictConfig(conf) >>> logging.info("Transaction completed normally") INFO : root : Transaction completed normally >>> logging.critical("Abnormal termination") 2011-02-17 11:14:36,694 root CRITICAL Abnormal termination See also ........ PEP 391(1) - Dictionary Based Configuration for Logging PEP written by Vinay Sajip. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0391  File: python.info, Node: PEP 3148 The concurrent futures module, Next: PEP 3147 PYC Repository Directories, Prev: PEP 391 Dictionary Based Configuration for Logging, Up: What’s New In Python 3 2 1.7.4 PEP 3148: The ‘concurrent.futures’ module ----------------------------------------------- Code for creating and managing concurrency is being collected in a new top-level namespace, `concurrent'. Its first member is a `futures' package which provides a uniform high-level interface for managing threads and processes. The design for *note concurrent.futures: 22. was inspired by the `java.util.concurrent' package. In that model, a running call and its result are represented by a *note Future: b2d. object that abstracts features common to threads, processes, and remote procedure calls. That object supports status checks (running or done), timeouts, cancellations, adding callbacks, and access to results or exceptions. The primary offering of the new module is a pair of executor classes for launching and managing calls. The goal of the executors is to make it easier to use existing tools for making parallel calls. They save the effort needed to setup a pool of resources, launch the calls, create a results queue, add time-out handling, and limit the total number of threads, processes, or remote procedure calls. Ideally, each application should share a single executor across multiple components so that process and thread limits can be centrally managed. This solves the design challenge that arises when each component has its own competing strategy for resource management. Both classes share a common interface with three methods: *note submit(): 2a3. for scheduling a callable and returning a *note Future: b2d. object; *note map(): 6be. for scheduling many asynchronous calls at a time, and *note shutdown(): b2e. for freeing resources. The class is a *note context manager: 568. and can be used in a *note with: 6e9. statement to assure that resources are automatically released when currently pending futures are done executing. A simple of example of *note ThreadPoolExecutor: 27a. is a launch of four parallel threads for copying files: import concurrent.futures, shutil with concurrent.futures.ThreadPoolExecutor(max_workers=4) as e: e.submit(shutil.copy, 'src1.txt', 'dest1.txt') e.submit(shutil.copy, 'src2.txt', 'dest2.txt') e.submit(shutil.copy, 'src3.txt', 'dest3.txt') e.submit(shutil.copy, 'src3.txt', 'dest4.txt') See also ........ PEP 3148(1) - Futures – Execute Computations Asynchronously PEP written by Brian Quinlan. *note Code for Threaded Parallel URL reads: b2f, an example using threads to fetch multiple web pages in parallel. *note Code for computing prime numbers in parallel: b30, an example demonstrating *note ProcessPoolExecutor: 2a4. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3148  File: python.info, Node: PEP 3147 PYC Repository Directories, Next: PEP 3149 ABI Version Tagged so Files, Prev: PEP 3148 The concurrent futures module, Up: What’s New In Python 3 2 1.7.5 PEP 3147: PYC Repository Directories ------------------------------------------ Python’s scheme for caching bytecode in `.pyc' files did not work well in environments with multiple Python interpreters. If one interpreter encountered a cached file created by another interpreter, it would recompile the source and overwrite the cached file, thus losing the benefits of caching. The issue of “pyc fights” has become more pronounced as it has become commonplace for Linux distributions to ship with multiple versions of Python. These conflicts also arise with CPython alternatives such as Unladen Swallow. To solve this problem, Python’s import machinery has been extended to use distinct filenames for each interpreter. Instead of Python 3.2 and Python 3.3 and Unladen Swallow each competing for a file called “mymodule.pyc”, they will now look for “mymodule.cpython-32.pyc”, “mymodule.cpython-33.pyc”, and “mymodule.unladen10.pyc”. And to prevent all of these new files from cluttering source directories, the `pyc' files are now collected in a “__pycache__” directory stored under the package directory. Aside from the filenames and target directories, the new scheme has a few aspects that are visible to the programmer: * Imported modules now have a *note __cached__: b32. attribute which stores the name of the actual file that was imported: >>> import collections >>> collections.__cached__ 'c:/py32/lib/__pycache__/collections.cpython-32.pyc' * The tag that is unique to each interpreter is accessible from the *note imp: 9a. module: >>> import imp >>> imp.get_tag() 'cpython-32' * Scripts that try to deduce source filename from the imported file now need to be smarter. It is no longer sufficient to simply strip the “c” from a “.pyc” filename. Instead, use the new functions in the *note imp: 9a. module: >>> imp.source_from_cache('c:/py32/lib/__pycache__/collections.cpython-32.pyc') 'c:/py32/lib/collections.py' >>> imp.cache_from_source('c:/py32/lib/collections.py') 'c:/py32/lib/__pycache__/collections.cpython-32.pyc' * The *note py_compile: d7. and *note compileall: 21. modules have been updated to reflect the new naming convention and target directory. The command-line invocation of `compileall' has new options: ‘-i’ for specifying a list of files and directories to compile and ‘-b’ which causes bytecode files to be written to their legacy location rather than `__pycache__'. * The *note importlib.abc: 9c. module has been updated with new *note abstract base classes: b33. for loading bytecode files. The obsolete ABCs, ‘PyLoader’ and ‘PyPycLoader’, have been deprecated (instructions on how to stay Python 3.1 compatible are included with the documentation). See also ........ PEP 3147(1) - PYC Repository Directories PEP written by Barry Warsaw. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: PEP 3149 ABI Version Tagged so Files, Next: PEP 3333 Python Web Server Gateway Interface v1 0 1, Prev: PEP 3147 PYC Repository Directories, Up: What’s New In Python 3 2 1.7.6 PEP 3149: ABI Version Tagged .so Files -------------------------------------------- The PYC repository directory allows multiple bytecode cache files to be co-located. This PEP implements a similar mechanism for shared object files by giving them a common directory and distinct names for each version. The common directory is “pyshared” and the file names are made distinct by identifying the Python implementation (such as CPython, PyPy, Jython, etc.), the major and minor version numbers, and optional build flags (such as “d” for debug, “m” for pymalloc, “u” for wide-unicode). For an arbitrary package “foo”, you may see these files when the distribution package is installed: /usr/share/pyshared/foo.cpython-32m.so /usr/share/pyshared/foo.cpython-33md.so In Python itself, the tags are accessible from functions in the *note sysconfig: fe. module: >>> import sysconfig >>> sysconfig.get_config_var('SOABI') # find the version tag 'cpython-32mu' >>> sysconfig.get_config_var('EXT_SUFFIX') # find the full filename extension '.cpython-32mu.so' See also ........ PEP 3149(1) - ABI Version Tagged .so Files PEP written by Barry Warsaw. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3149  File: python.info, Node: PEP 3333 Python Web Server Gateway Interface v1 0 1, Next: Other Language Changes<7>, Prev: PEP 3149 ABI Version Tagged so Files, Up: What’s New In Python 3 2 1.7.7 PEP 3333: Python Web Server Gateway Interface v1.0.1 ---------------------------------------------------------- This informational PEP clarifies how bytes/text issues are to be handled by the WSGI protocol. The challenge is that string handling in Python 3 is most conveniently handled with the *note str: 330. type even though the HTTP protocol is itself bytes oriented. The PEP differentiates so-called `native strings' that are used for request/response headers and metadata versus `byte strings' which are used for the bodies of requests and responses. The `native strings' are always of type *note str: 330. but are restricted to code points between `U+0000' through `U+00FF' which are translatable to bytes using `Latin-1' encoding. These strings are used for the keys and values in the environment dictionary and for response headers and statuses in the ‘start_response()’ function. They must follow RFC 2616(1) with respect to encoding. That is, they must either be `ISO-8859-1' characters or use RFC 2047(2) MIME encoding. For developers porting WSGI applications from Python 2, here are the salient points: * If the app already used strings for headers in Python 2, no change is needed. * If instead, the app encoded output headers or decoded input headers, then the headers will need to be re-encoded to Latin-1. For example, an output header encoded in utf-8 was using ‘h.encode('utf-8')’ now needs to convert from bytes to native strings using ‘h.encode('utf-8').decode('latin-1')’. * Values yielded by an application or sent using the ‘write()’ method must be byte strings. The ‘start_response()’ function and environ must use native strings. The two cannot be mixed. For server implementers writing CGI-to-WSGI pathways or other CGI-style protocols, the users must to be able access the environment using native strings even though the underlying platform may have a different convention. To bridge this gap, the *note wsgiref: 12c. module has a new function, *note wsgiref.handlers.read_environ(): b36. for transcoding CGI variables from *note os.environ: b37. into native strings and returning a new dictionary. See also ........ PEP 3333(3) - Python Web Server Gateway Interface v1.0.1 PEP written by Phillip Eby. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2616.html (2) https://tools.ietf.org/html/rfc2047.html (3) https://www.python.org/dev/peps/pep-3333  File: python.info, Node: Other Language Changes<7>, Next: New Improved and Deprecated Modules, Prev: PEP 3333 Python Web Server Gateway Interface v1 0 1, Up: What’s New In Python 3 2 1.7.8 Other Language Changes ---------------------------- Some smaller changes made to the core Python language are: * String formatting for *note format(): 4db. and *note str.format(): 4da. gained new capabilities for the format character `#'. Previously, for integers in binary, octal, or hexadecimal, it caused the output to be prefixed with ‘0b’, ‘0o’, or ‘0x’ respectively. Now it can also handle floats, complex, and Decimal, causing the output to always have a decimal point even when no digits follow it. >>> format(20, '#o') '0o24' >>> format(12.34, '#5.0f') ' 12.' (Suggested by Mark Dickinson and implemented by Eric Smith in bpo-7094(1).) * There is also a new *note str.format_map(): 6b1. method that extends the capabilities of the existing *note str.format(): 4da. method by accepting arbitrary *note mapping: b39. objects. This new method makes it possible to use string formatting with any of Python’s many dictionary-like objects such as *note defaultdict: b3a, *note Shelf: 8b0, *note ConfigParser: 4aa, or *note dbm: 32. It is also useful with custom *note dict: 1b8. subclasses that normalize keys before look-up or that supply a *note __missing__(): b3b. method for unknown keys: >>> import shelve >>> d = shelve.open('tmp.shl') >>> 'The {project_name} status is {status} as of {date}'.format_map(d) 'The testing project status is green as of February 15, 2011' >>> class LowerCasedDict(dict): ... def __getitem__(self, key): ... return dict.__getitem__(self, key.lower()) >>> lcd = LowerCasedDict(part='widgets', quantity=10) >>> 'There are {QUANTITY} {Part} in stock'.format_map(lcd) 'There are 10 widgets in stock' >>> class PlaceholderDict(dict): ... def __missing__(self, key): ... return '<{}>'.format(key) >>> 'Hello {name}, welcome to {location}'.format_map(PlaceholderDict()) 'Hello , welcome to ' (Suggested by Raymond Hettinger and implemented by Eric Smith in bpo-6081(2).) * The interpreter can now be started with a quiet option, ‘-q’, to prevent the copyright and version information from being displayed in the interactive mode. The option can be introspected using the *note sys.flags: b3c. attribute: $ python -q >>> sys.flags sys.flags(debug=0, division_warning=0, inspect=0, interactive=0, optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0, ignore_environment=0, verbose=0, bytes_warning=0, quiet=1) (Contributed by Marcin Wojdyr in bpo-1772833(3)). * The *note hasattr(): 447. function works by calling *note getattr(): 448. and detecting whether an exception is raised. This technique allows it to detect methods created dynamically by *note __getattr__(): 31a. or *note __getattribute__(): 449. which would otherwise be absent from the class dictionary. Formerly, `hasattr' would catch any exception, possibly masking genuine errors. Now, `hasattr' has been tightened to only catch *note AttributeError: 39b. and let other exceptions pass through: >>> class A: ... @property ... def f(self): ... return 1 // 0 ... >>> a = A() >>> hasattr(a, 'f') Traceback (most recent call last): ... ZeroDivisionError: integer division or modulo by zero (Discovered by Yury Selivanov and fixed by Benjamin Peterson; bpo-9666(4).) * The *note str(): 330. of a float or complex number is now the same as its *note repr(): 7cc. Previously, the *note str(): 330. form was shorter but that just caused confusion and is no longer needed now that the shortest possible *note repr(): 7cc. is displayed by default: >>> import math >>> repr(math.pi) '3.141592653589793' >>> str(math.pi) '3.141592653589793' (Proposed and implemented by Mark Dickinson; bpo-9337(5).) * *note memoryview: 25c. objects now have a *note release(): b3d. method and they also now support the context management protocol. This allows timely release of any resources that were acquired when requesting a buffer from the original object. >>> with memoryview(b'abcdefgh') as v: ... print(v.tolist()) [97, 98, 99, 100, 101, 102, 103, 104] (Added by Antoine Pitrou; bpo-9757(6).) * Previously it was illegal to delete a name from the local namespace if it occurs as a free variable in a nested block: def outer(x): def inner(): return x inner() del x This is now allowed. Remember that the target of an *note except: b3e. clause is cleared, so this code which used to work with Python 2.6, raised a *note SyntaxError: 458. with Python 3.1 and now works again: def f(): def print_error(): print(e) try: something except Exception as e: print_error() # implicit "del e" here (See bpo-4617(7).) * The internal ‘structsequence’ tool now creates subclasses of tuple. This means that C structures like those returned by *note os.stat(): 1f1, *note time.gmtime(): b3f, and *note sys.version_info: b1a. now work like a *note named tuple: aa3. and now work with functions and methods that expect a tuple as an argument. This is a big step forward in making the C structures as flexible as their pure Python counterparts: >>> import sys >>> isinstance(sys.version_info, tuple) True >>> 'Version %d.%d.%d %s(%d)' % sys.version_info 'Version 3.2.0 final(0)' (Suggested by Arfrever Frehtes Taifersar Arahesis and implemented by Benjamin Peterson in bpo-8413(8).) * Warnings are now easier to control using the *note PYTHONWARNINGS: 418. environment variable as an alternative to using ‘-W’ at the command line: $ export PYTHONWARNINGS='ignore::RuntimeWarning::,once::UnicodeWarning::' (Suggested by Barry Warsaw and implemented by Philip Jenvey in bpo-7301(9).) * A new warning category, *note ResourceWarning: 4d0, has been added. It is emitted when potential issues with resource consumption or cleanup are detected. It is silenced by default in normal release builds but can be enabled through the means provided by the *note warnings: 126. module, or on the command line. A *note ResourceWarning: 4d0. is issued at interpreter shutdown if the *note gc.garbage: b40. list isn’t empty, and if *note gc.DEBUG_UNCOLLECTABLE: b41. is set, all uncollectable objects are printed. This is meant to make the programmer aware that their code contains object finalization issues. A *note ResourceWarning: 4d0. is also issued when a *note file object: b42. is destroyed without having been explicitly closed. While the deallocator for such object ensures it closes the underlying operating system resource (usually, a file descriptor), the delay in deallocating the object could produce various issues, especially under Windows. Here is an example of enabling the warning from the command line: $ python -q -Wdefault >>> f = open("foo", "wb") >>> del f __main__:1: ResourceWarning: unclosed file <_io.BufferedWriter name='foo'> (Added by Antoine Pitrou and Georg Brandl in bpo-10093(10) and bpo-477863(11).) * *note range: 9be. objects now support `index' and `count' methods. This is part of an effort to make more objects fully implement the ‘collections.Sequence’ *note abstract base class: b33. As a result, the language will have a more uniform API. In addition, *note range: 9be. objects now support slicing and negative indices, even with values larger than *note sys.maxsize: b43. This makes `range' more interoperable with lists: >>> range(0, 100, 2).count(10) 1 >>> range(0, 100, 2).index(10) 5 >>> range(0, 100, 2)[5] 10 >>> range(0, 100, 2)[0:5] range(0, 10, 2) (Contributed by Daniel Stutzbach in bpo-9213(12), by Alexander Belopolsky in bpo-2690(13), and by Nick Coghlan in bpo-10889(14).) * The *note callable(): b44. builtin function from Py2.x was resurrected. It provides a concise, readable alternative to using an *note abstract base class: b33. in an expression like ‘isinstance(x, collections.Callable)’: >>> callable(max) True >>> callable(20) False (See bpo-10518(15).) * Python’s import mechanism can now load modules installed in directories with non-ASCII characters in the path name. This solved an aggravating problem with home directories for users with non-ASCII characters in their usernames. (Required extensive work by Victor Stinner in bpo-9425(16).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue7094 (2) https://bugs.python.org/issue6081 (3) https://bugs.python.org/issue1772833 (4) https://bugs.python.org/issue9666 (5) https://bugs.python.org/issue9337 (6) https://bugs.python.org/issue9757 (7) https://bugs.python.org/issue4617 (8) https://bugs.python.org/issue8413 (9) https://bugs.python.org/issue7301 (10) https://bugs.python.org/issue10093 (11) https://bugs.python.org/issue477863 (12) https://bugs.python.org/issue9213 (13) https://bugs.python.org/issue2690 (14) https://bugs.python.org/issue10889 (15) https://bugs.python.org/issue10518 (16) https://bugs.python.org/issue9425  File: python.info, Node: New Improved and Deprecated Modules, Next: Multi-threading, Prev: Other Language Changes<7>, Up: What’s New In Python 3 2 1.7.9 New, Improved, and Deprecated Modules ------------------------------------------- Python’s standard library has undergone significant maintenance efforts and quality improvements. The biggest news for Python 3.2 is that the *note email: 69. package, *note mailbox: ae. module, and *note nntplib: c0. modules now work correctly with the bytes/text model in Python 3. For the first time, there is correct handling of messages with mixed encodings. Throughout the standard library, there has been more careful attention to encodings and text versus bytes issues. In particular, interactions with the operating system are now better able to exchange non-ASCII data using the Windows MBCS encoding, locale-aware encodings, or UTF-8. Another significant win is the addition of substantially better support for `SSL' connections and security certificates. In addition, more classes now implement a *note context manager: 568. to support convenient and reliable resource clean-up using a *note with: 6e9. statement. * Menu: * email: email<5>. * elementtree:: * functools: functools<6>. * itertools: itertools<4>. * collections: collections<8>. * threading: threading<6>. * datetime and time:: * math: math<6>. * abc: abc<3>. * io: io<5>. * reprlib:: * logging: logging<7>. * csv: csv<3>. * contextlib: contextlib<6>. * decimal and fractions:: * ftp:: * popen:: * select: select<3>. * gzip and zipfile:: * tarfile: tarfile<5>. * hashlib: hashlib<3>. * ast: ast<3>. * os: os<8>. * shutil: shutil<5>. * sqlite3: sqlite3<6>. * html: html<3>. * socket: socket<8>. * ssl: ssl<9>. * nntp:: * certificates:: * imaplib: imaplib<3>. * http.client: http client<4>. * unittest: unittest<6>. * random: random<2>. * poplib: poplib<3>. * asyncore: asyncore<2>. * tempfile: tempfile<2>. * inspect: inspect<6>. * pydoc: pydoc<5>. * dis: dis<3>. * dbm: dbm<6>. * ctypes: ctypes<2>. * site: site<2>. * sysconfig: sysconfig<2>. * pdb: pdb<5>. * configparser: configparser<2>. * urllib.parse: urllib parse<2>. * mailbox:: * turtledemo::  File: python.info, Node: email<5>, Next: elementtree, Up: New Improved and Deprecated Modules 1.7.9.1 email ............. The usability of the *note email: 69. package in Python 3 has been mostly fixed by the extensive efforts of R. David Murray. The problem was that emails are typically read and stored in the form of *note bytes: 331. rather than *note str: 330. text, and they may contain multiple encodings within a single email. So, the email package had to be extended to parse and generate email messages in bytes format. * New functions *note message_from_bytes(): b47. and *note message_from_binary_file(): b48, and new classes *note BytesFeedParser: b49. and *note BytesParser: b4a. allow binary message data to be parsed into model objects. * Given bytes input to the model, *note get_payload(): b4b. will by default decode a message body that has a ‘Content-Transfer-Encoding’ of `8bit' using the charset specified in the MIME headers and return the resulting string. * Given bytes input to the model, *note Generator: b4c. will convert message bodies that have a ‘Content-Transfer-Encoding’ of `8bit' to instead have a `7bit' ‘Content-Transfer-Encoding’. Headers with unencoded non-ASCII bytes are deemed to be RFC 2047(1)-encoded using the `unknown-8bit' character set. * A new class *note BytesGenerator: b4d. produces bytes as output, preserving any unchanged non-ASCII data that was present in the input used to build the model, including message bodies with a ‘Content-Transfer-Encoding’ of `8bit'. * The *note smtplib: ed. *note SMTP: a81. class now accepts a byte string for the `msg' argument to the *note sendmail(): 744. method, and a new method, *note send_message(): 745. accepts a *note Message: 541. object and can optionally obtain the `from_addr' and `to_addrs' addresses directly from the object. (Proposed and implemented by R. David Murray, bpo-4661(2) and bpo-10321(3).) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2047.html (2) https://bugs.python.org/issue4661 (3) https://bugs.python.org/issue10321  File: python.info, Node: elementtree, Next: functools<6>, Prev: email<5>, Up: New Improved and Deprecated Modules 1.7.9.2 elementtree ................... The *note xml.etree.ElementTree: 137. package and its ‘xml.etree.cElementTree’ counterpart have been updated to version 1.3. Several new and useful functions and methods have been added: * *note xml.etree.ElementTree.fromstringlist(): b4f. which builds an XML document from a sequence of fragments * *note xml.etree.ElementTree.register_namespace(): b50. for registering a global namespace prefix * *note xml.etree.ElementTree.tostringlist(): 916. for string representation including all sublists * *note xml.etree.ElementTree.Element.extend(): b51. for appending a sequence of zero or more elements * *note xml.etree.ElementTree.Element.iterfind(): b52. searches an element and subelements * *note xml.etree.ElementTree.Element.itertext(): b53. creates a text iterator over an element and its subelements * *note xml.etree.ElementTree.TreeBuilder.end(): b54. closes the current element * *note xml.etree.ElementTree.TreeBuilder.doctype(): 2c1. handles a doctype declaration Two methods have been deprecated: * ‘xml.etree.ElementTree.getchildren()’ use ‘list(elem)’ instead. * ‘xml.etree.ElementTree.getiterator()’ use ‘Element.iter’ instead. For details of the update, see Introducing ElementTree(1) on Fredrik Lundh’s website. (Contributed by Florent Xicluna and Fredrik Lundh, bpo-6472(2).) ---------- Footnotes ---------- (1) http://effbot.org/zone/elementtree-13-intro.htm (2) https://bugs.python.org/issue6472  File: python.info, Node: functools<6>, Next: itertools<4>, Prev: elementtree, Up: New Improved and Deprecated Modules 1.7.9.3 functools ................. * The *note functools: 85. module includes a new decorator for caching function calls. *note functools.lru_cache(): 1c7. can save repeated queries to an external resource whenever the results are expected to be the same. For example, adding a caching decorator to a database query function can save database accesses for popular searches: >>> import functools >>> @functools.lru_cache(maxsize=300) ... def get_phone_number(name): ... c = conn.cursor() ... c.execute('SELECT phonenumber FROM phonelist WHERE name=?', (name,)) ... return c.fetchone()[0] >>> for name in user_requests: ... get_phone_number(name) # cached lookup To help with choosing an effective cache size, the wrapped function is instrumented for tracking cache statistics: >>> get_phone_number.cache_info() CacheInfo(hits=4805, misses=980, maxsize=300, currsize=300) If the phonelist table gets updated, the outdated contents of the cache can be cleared with: >>> get_phone_number.cache_clear() (Contributed by Raymond Hettinger and incorporating design ideas from Jim Baker, Miki Tebeka, and Nick Coghlan; see recipe 498245(1), recipe 577479(2), bpo-10586(3), and bpo-10593(4).) * The *note functools.wraps(): 86a. decorator now adds a ‘__wrapped__’ attribute pointing to the original callable function. This allows wrapped functions to be introspected. It also copies ‘__annotations__’ if defined. And now it also gracefully skips over missing attributes such as ‘__doc__’ which might not be defined for the wrapped callable. In the above example, the cache can be removed by recovering the original function: >>> get_phone_number = get_phone_number.__wrapped__ # uncached function (By Nick Coghlan and Terrence Cole; bpo-9567(5), bpo-3445(6), and bpo-8814(7).) * To help write classes with rich comparison methods, a new decorator *note functools.total_ordering(): 84b. will use existing equality and inequality methods to fill in the remaining methods. For example, supplying `__eq__' and `__lt__' will enable *note total_ordering(): 84b. to fill-in `__le__', `__gt__' and `__ge__': @total_ordering class Student: def __eq__(self, other): return ((self.lastname.lower(), self.firstname.lower()) == (other.lastname.lower(), other.firstname.lower())) def __lt__(self, other): return ((self.lastname.lower(), self.firstname.lower()) < (other.lastname.lower(), other.firstname.lower())) With the `total_ordering' decorator, the remaining comparison methods are filled in automatically. (Contributed by Raymond Hettinger.) * To aid in porting programs from Python 2, the *note functools.cmp_to_key(): b56. function converts an old-style comparison function to modern *note key function: 6e0.: >>> # locale-aware sort order >>> sorted(iterable, key=cmp_to_key(locale.strcoll)) For sorting examples and a brief sorting tutorial, see the Sorting HowTo(8) tutorial. (Contributed by Raymond Hettinger.) ---------- Footnotes ---------- (1) https://code.activestate.com/recipes/498245 (2) https://code.activestate.com/recipes/577479 (3) https://bugs.python.org/issue10586 (4) https://bugs.python.org/issue10593 (5) https://bugs.python.org/issue9567 (6) https://bugs.python.org/issue3445 (7) https://bugs.python.org/issue8814 (8) https://wiki.python.org/moin/HowTo/Sorting/  File: python.info, Node: itertools<4>, Next: collections<8>, Prev: functools<6>, Up: New Improved and Deprecated Modules 1.7.9.4 itertools ................. * The *note itertools: a3. module has a new *note accumulate(): 1dd. function modeled on APL’s `scan' operator and Numpy’s `accumulate' function: >>> from itertools import accumulate >>> list(accumulate([8, 2, 50])) [8, 10, 60] >>> prob_dist = [0.1, 0.4, 0.2, 0.3] >>> list(accumulate(prob_dist)) # cumulative probability distribution [0.1, 0.5, 0.7, 1.0] For an example using *note accumulate(): 1dd, see the *note examples for the random module: b58. (Contributed by Raymond Hettinger and incorporating design suggestions from Mark Dickinson.)  File: python.info, Node: collections<8>, Next: threading<6>, Prev: itertools<4>, Up: New Improved and Deprecated Modules 1.7.9.5 collections ................... * The *note collections.Counter: 9da. class now has two forms of in-place subtraction, the existing `-=' operator for saturating subtraction(1) and the new *note subtract(): b5a. method for regular subtraction. The former is suitable for multisets(2) which only have positive counts, and the latter is more suitable for use cases that allow negative counts: >>> from collections import Counter >>> tally = Counter(dogs=5, cats=3) >>> tally -= Counter(dogs=2, cats=8) # saturating subtraction >>> tally Counter({'dogs': 3}) >>> tally = Counter(dogs=5, cats=3) >>> tally.subtract(dogs=2, cats=8) # regular subtraction >>> tally Counter({'dogs': 3, 'cats': -5}) (Contributed by Raymond Hettinger.) * The *note collections.OrderedDict: 1b9. class has a new method *note move_to_end(): b5b. which takes an existing key and moves it to either the first or last position in the ordered sequence. The default is to move an item to the last position. This is equivalent of renewing an entry with ‘od[k] = od.pop(k)’. A fast move-to-end operation is useful for resequencing entries. For example, an ordered dictionary can be used to track order of access by aging entries from the oldest to the most recently accessed. >>> from collections import OrderedDict >>> d = OrderedDict.fromkeys(['a', 'b', 'X', 'd', 'e']) >>> list(d) ['a', 'b', 'X', 'd', 'e'] >>> d.move_to_end('X') >>> list(d) ['a', 'b', 'd', 'e', 'X'] (Contributed by Raymond Hettinger.) * The *note collections.deque: 531. class grew two new methods *note count(): b5c. and *note reverse(): b5d. that make them more substitutable for *note list: 262. objects: >>> from collections import deque >>> d = deque('simsalabim') >>> d.count('s') 2 >>> d.reverse() >>> d deque(['m', 'i', 'b', 'a', 'l', 'a', 's', 'm', 'i', 's']) (Contributed by Raymond Hettinger.) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Saturation_arithmetic (2) https://en.wikipedia.org/wiki/Multiset  File: python.info, Node: threading<6>, Next: datetime and time, Prev: collections<8>, Up: New Improved and Deprecated Modules 1.7.9.6 threading ................. The *note threading: 109. module has a new *note Barrier: b5f. synchronization class for making multiple threads wait until all of them have reached a common barrier point. Barriers are useful for making sure that a task with multiple preconditions does not run until all of the predecessor tasks are complete. Barriers can work with an arbitrary number of threads. This is a generalization of a Rendezvous(1) which is defined for only two threads. Implemented as a two-phase cyclic barrier, *note Barrier: b5f. objects are suitable for use in loops. The separate `filling' and `draining' phases assure that all threads get released (drained) before any one of them can loop back and re-enter the barrier. The barrier fully resets after each cycle. Example of using barriers: from threading import Barrier, Thread def get_votes(site): ballots = conduct_election(site) all_polls_closed.wait() # do not count until all polls are closed totals = summarize(ballots) publish(site, totals) all_polls_closed = Barrier(len(sites)) for site in sites: Thread(target=get_votes, args=(site,)).start() In this example, the barrier enforces a rule that votes cannot be counted at any polling site until all polls are closed. Notice how a solution with a barrier is similar to one with *note threading.Thread.join(): b60, but the threads stay alive and continue to do work (summarizing ballots) after the barrier point is crossed. If any of the predecessor tasks can hang or be delayed, a barrier can be created with an optional `timeout' parameter. Then if the timeout period elapses before all the predecessor tasks reach the barrier point, all waiting threads are released and a *note BrokenBarrierError: b61. exception is raised: def get_votes(site): ballots = conduct_election(site) try: all_polls_closed.wait(timeout=midnight - time.now()) except BrokenBarrierError: lockbox = seal_ballots(ballots) queue.put(lockbox) else: totals = summarize(ballots) publish(site, totals) In this example, the barrier enforces a more robust rule. If some election sites do not finish before midnight, the barrier times-out and the ballots are sealed and deposited in a queue for later handling. See Barrier Synchronization Patterns(2) for more examples of how barriers can be used in parallel computing. Also, there is a simple but thorough explanation of barriers in The Little Book of Semaphores(3), `section 3.6'. (Contributed by Kristján Valur Jónsson with an API review by Jeffrey Yasskin in bpo-8777(4).) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Synchronous_rendezvous (2) http://osl.cs.illinois.edu/media/papers/karmani-2009-barrier_synchronization_pattern.pdf (3) https://greenteapress.com/semaphores/LittleBookOfSemaphores.pdf (4) https://bugs.python.org/issue8777  File: python.info, Node: datetime and time, Next: math<6>, Prev: threading<6>, Up: New Improved and Deprecated Modules 1.7.9.7 datetime and time ......................... * The *note datetime: 31. module has a new type *note timezone: a01. that implements the *note tzinfo: 380. interface by returning a fixed UTC offset and timezone name. This makes it easier to create timezone-aware datetime objects: >>> from datetime import datetime, timezone >>> datetime.now(timezone.utc) datetime.datetime(2010, 12, 8, 21, 4, 2, 923754, tzinfo=datetime.timezone.utc) >>> datetime.strptime("01/01/2000 12:00 +0000", "%m/%d/%Y %H:%M %z") datetime.datetime(2000, 1, 1, 12, 0, tzinfo=datetime.timezone.utc) * Also, *note timedelta: 195. objects can now be multiplied by *note float: 187. and divided by *note float: 187. and *note int: 184. objects. And *note timedelta: 195. objects can now divide one another. * The *note datetime.date.strftime(): 538. method is no longer restricted to years after 1900. The new supported year range is from 1000 to 9999 inclusive. * Whenever a two-digit year is used in a time tuple, the interpretation has been governed by ‘time.accept2dyear’. The default is ‘True’ which means that for a two-digit year, the century is guessed according to the POSIX rules governing the ‘%y’ strptime format. Starting with Py3.2, use of the century guessing heuristic will emit a *note DeprecationWarning: 278. Instead, it is recommended that ‘time.accept2dyear’ be set to ‘False’ so that large date ranges can be used without guesswork: >>> import time, warnings >>> warnings.resetwarnings() # remove the default warning filters >>> time.accept2dyear = True # guess whether 11 means 11 or 2011 >>> time.asctime((11, 1, 1, 12, 34, 56, 4, 1, 0)) Warning (from warnings module): ... DeprecationWarning: Century info guessed for a 2-digit year. 'Fri Jan 1 12:34:56 2011' >>> time.accept2dyear = False # use the full range of allowable dates >>> time.asctime((11, 1, 1, 12, 34, 56, 4, 1, 0)) 'Fri Jan 1 12:34:56 11' Several functions now have significantly expanded date ranges. When ‘time.accept2dyear’ is false, the *note time.asctime(): b63. function will accept any year that fits in a C int, while the *note time.mktime(): b64. and *note time.strftime(): b65. functions will accept the full range supported by the corresponding operating system functions. (Contributed by Alexander Belopolsky and Victor Stinner in bpo-1289118(1), bpo-5094(2), bpo-6641(3), bpo-2706(4), bpo-1777412(5), bpo-8013(6), and bpo-10827(7).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1289118 (2) https://bugs.python.org/issue5094 (3) https://bugs.python.org/issue6641 (4) https://bugs.python.org/issue2706 (5) https://bugs.python.org/issue1777412 (6) https://bugs.python.org/issue8013 (7) https://bugs.python.org/issue10827  File: python.info, Node: math<6>, Next: abc<3>, Prev: datetime and time, Up: New Improved and Deprecated Modules 1.7.9.8 math ............ The *note math: b1. module has been updated with six new functions inspired by the C99 standard. The *note isfinite(): b67. function provides a reliable and fast way to detect special values. It returns ‘True’ for regular numbers and ‘False’ for `Nan' or `Infinity': >>> from math import isfinite >>> [isfinite(x) for x in (123, 4.56, float('Nan'), float('Inf'))] [True, True, False, False] The *note expm1(): b68. function computes ‘e**x-1’ for small values of `x' without incurring the loss of precision that usually accompanies the subtraction of nearly equal quantities: >>> from math import expm1 >>> expm1(0.013671875) # more accurate way to compute e**x-1 for a small x 0.013765762467652909 The *note erf(): 452. function computes a probability integral or Gaussian error function(1). The complementary error function, *note erfc(): 453, is ‘1 - erf(x)’: >>> from math import erf, erfc, sqrt >>> erf(1.0/sqrt(2.0)) # portion of normal distribution within 1 standard deviation 0.682689492137086 >>> erfc(1.0/sqrt(2.0)) # portion of normal distribution outside 1 standard deviation 0.31731050786291404 >>> erf(1.0/sqrt(2.0)) + erfc(1.0/sqrt(2.0)) 1.0 The *note gamma(): b69. function is a continuous extension of the factorial function. See ‘https://en.wikipedia.org/wiki/Gamma_function’ for details. Because the function is related to factorials, it grows large even for small values of `x', so there is also a *note lgamma(): b6a. function for computing the natural logarithm of the gamma function: >>> from math import gamma, lgamma >>> gamma(7.0) # six factorial 720.0 >>> lgamma(801.0) # log(800 factorial) 4551.950730698041 (Contributed by Mark Dickinson.) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Error_function  File: python.info, Node: abc<3>, Next: io<5>, Prev: math<6>, Up: New Improved and Deprecated Modules 1.7.9.9 abc ........... The *note abc: 4. module now supports *note abstractclassmethod(): 9cf. and *note abstractstaticmethod(): 9d0. These tools make it possible to define an *note abstract base class: b33. that requires a particular *note classmethod(): 1d8. or *note staticmethod(): 1d9. to be implemented: class Temperature(metaclass=abc.ABCMeta): @abc.abstractclassmethod def from_fahrenheit(cls, t): ... @abc.abstractclassmethod def from_celsius(cls, t): ... (Patch submitted by Daniel Urban; bpo-5867(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5867  File: python.info, Node: io<5>, Next: reprlib, Prev: abc<3>, Up: New Improved and Deprecated Modules 1.7.9.10 io ........... The *note io.BytesIO: 79b. has a new method, *note getbuffer(): b6d, which provides functionality similar to *note memoryview(): 25c. It creates an editable view of the data without making a copy. The buffer’s random access and support for slice notation are well-suited to in-place editing: >>> REC_LEN, LOC_START, LOC_LEN = 34, 7, 11 >>> def change_location(buffer, record_number, location): ... start = record_number * REC_LEN + LOC_START ... buffer[start: start+LOC_LEN] = location >>> import io >>> byte_stream = io.BytesIO( ... b'G3805 storeroom Main chassis ' ... b'X7899 shipping Reserve cog ' ... b'L6988 receiving Primary sprocket' ... ) >>> buffer = byte_stream.getbuffer() >>> change_location(buffer, 1, b'warehouse ') >>> change_location(buffer, 0, b'showroom ') >>> print(byte_stream.getvalue()) b'G3805 showroom Main chassis ' b'X7899 warehouse Reserve cog ' b'L6988 receiving Primary sprocket' (Contributed by Antoine Pitrou in bpo-5506(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5506  File: python.info, Node: reprlib, Next: logging<7>, Prev: io<5>, Up: New Improved and Deprecated Modules 1.7.9.11 reprlib ................ When writing a *note __repr__(): 33e. method for a custom container, it is easy to forget to handle the case where a member refers back to the container itself. Python’s builtin objects such as *note list: 262. and *note set: b6f. handle self-reference by displaying “…” in the recursive part of the representation string. To help write such *note __repr__(): 33e. methods, the *note reprlib: df. module has a new decorator, *note recursive_repr(): b70, for detecting recursive calls to *note __repr__(): 33e. and substituting a placeholder string instead: >>> class MyList(list): ... @recursive_repr() ... def __repr__(self): ... return '<' + '|'.join(map(repr, self)) + '>' ... >>> m = MyList('abc') >>> m.append(m) >>> m.append('x') >>> print(m) <'a'|'b'|'c'|...|'x'> (Contributed by Raymond Hettinger in bpo-9826(1) and bpo-9840(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9826 (2) https://bugs.python.org/issue9840  File: python.info, Node: logging<7>, Next: csv<3>, Prev: reprlib, Up: New Improved and Deprecated Modules 1.7.9.12 logging ................ In addition to dictionary-based configuration described above, the *note logging: aa. package has many other improvements. The logging documentation has been augmented by a *note basic tutorial: b72, an *note advanced tutorial: b73, and a *note cookbook: b74. of logging recipes. These documents are the fastest way to learn about logging. The *note logging.basicConfig(): 1e0. set-up function gained a `style' argument to support three different types of string formatting. It defaults to “%” for traditional %-formatting, can be set to “{” for the new *note str.format(): 4da. style, or can be set to “$” for the shell-style formatting provided by *note string.Template: 3eb. The following three configurations are equivalent: >>> from logging import basicConfig >>> basicConfig(style='%', format="%(name)s -> %(levelname)s: %(message)s") >>> basicConfig(style='{', format="{name} -> {levelname} {message}") >>> basicConfig(style='$', format="$name -> $levelname: $message") If no configuration is set-up before a logging event occurs, there is now a default configuration using a *note StreamHandler: b75. directed to *note sys.stderr: 30f. for events of ‘WARNING’ level or higher. Formerly, an event occurring before a configuration was set-up would either raise an exception or silently drop the event depending on the value of ‘logging.raiseExceptions’. The new default handler is stored in *note logging.lastResort: b76. The use of filters has been simplified. Instead of creating a *note Filter: b77. object, the predicate can be any Python callable that returns ‘True’ or ‘False’. There were a number of other improvements that add flexibility and simplify configuration. See the module documentation for a full listing of changes in Python 3.2.  File: python.info, Node: csv<3>, Next: contextlib<6>, Prev: logging<7>, Up: New Improved and Deprecated Modules 1.7.9.13 csv ............ The *note csv: 2a. module now supports a new dialect, *note unix_dialect: b79, which applies quoting for all fields and a traditional Unix style with ‘'\n'’ as the line terminator. The registered dialect name is ‘unix’. The *note csv.DictWriter: b7a. has a new method, *note writeheader(): b7b. for writing-out an initial row to document the field names: >>> import csv, sys >>> w = csv.DictWriter(sys.stdout, ['name', 'dept'], dialect='unix') >>> w.writeheader() "name","dept" >>> w.writerows([ ... {'name': 'tom', 'dept': 'accounting'}, ... {'name': 'susan', 'dept': 'Salesl'}]) "tom","accounting" "susan","sales" (New dialect suggested by Jay Talbot in bpo-5975(1), and the new method suggested by Ed Abraham in bpo-1537721(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5975 (2) https://bugs.python.org/issue1537721  File: python.info, Node: contextlib<6>, Next: decimal and fractions, Prev: csv<3>, Up: New Improved and Deprecated Modules 1.7.9.14 contextlib ................... There is a new and slightly mind-blowing tool *note ContextDecorator: b7d. that is helpful for creating a *note context manager: 568. that does double duty as a function decorator. As a convenience, this new functionality is used by *note contextmanager(): b7e. so that no extra effort is needed to support both roles. The basic idea is that both context managers and function decorators can be used for pre-action and post-action wrappers. Context managers wrap a group of statements using a *note with: 6e9. statement, and function decorators wrap a group of statements enclosed in a function. So, occasionally there is a need to write a pre-action or post-action wrapper that can be used in either role. For example, it is sometimes useful to wrap functions or groups of statements with a logger that can track the time of entry and time of exit. Rather than writing both a function decorator and a context manager for the task, the *note contextmanager(): b7e. provides both capabilities in a single definition: from contextlib import contextmanager import logging logging.basicConfig(level=logging.INFO) @contextmanager def track_entry_and_exit(name): logging.info('Entering: %s', name) yield logging.info('Exiting: %s', name) Formerly, this would have only been usable as a context manager: with track_entry_and_exit('widget loader'): print('Some time consuming activity goes here') load_widget() Now, it can be used as a decorator as well: @track_entry_and_exit('widget loader') def activity(): print('Some time consuming activity goes here') load_widget() Trying to fulfill two roles at once places some limitations on the technique. Context managers normally have the flexibility to return an argument usable by a *note with: 6e9. statement, but there is no parallel for function decorators. In the above example, there is not a clean way for the `track_entry_and_exit' context manager to return a logging instance for use in the body of enclosed statements. (Contributed by Michael Foord in bpo-9110(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9110  File: python.info, Node: decimal and fractions, Next: ftp, Prev: contextlib<6>, Up: New Improved and Deprecated Modules 1.7.9.15 decimal and fractions .............................. Mark Dickinson crafted an elegant and efficient scheme for assuring that different numeric datatypes will have the same hash value whenever their actual values are equal (bpo-8188(1)): assert hash(Fraction(3, 2)) == hash(1.5) == \ hash(Decimal("1.5")) == hash(complex(1.5, 0)) Some of the hashing details are exposed through a new attribute, *note sys.hash_info: 921, which describes the bit width of the hash value, the prime modulus, the hash values for `infinity' and `nan', and the multiplier used for the imaginary part of a number: >>> sys.hash_info sys.hash_info(width=64, modulus=2305843009213693951, inf=314159, nan=0, imag=1000003) An early decision to limit the inter-operability of various numeric types has been relaxed. It is still unsupported (and ill-advised) to have implicit mixing in arithmetic expressions such as ‘Decimal('1.1') + float('1.1')’ because the latter loses information in the process of constructing the binary float. However, since existing floating point value can be converted losslessly to either a decimal or rational representation, it makes sense to add them to the constructor and to support mixed-type comparisons. * The *note decimal.Decimal: 188. constructor now accepts *note float: 187. objects directly so there in no longer a need to use the *note from_float(): b80. method (bpo-8257(2)). * Mixed type comparisons are now fully supported so that *note Decimal: 188. objects can be directly compared with *note float: 187. and *note fractions.Fraction: 185. (bpo-2531(3) and bpo-8188(4)). Similar changes were made to *note fractions.Fraction: 185. so that the *note from_float(): b81. and *note from_decimal(): b82. methods are no longer needed (bpo-8294(5)): >>> from decimal import Decimal >>> from fractions import Fraction >>> Decimal(1.1) Decimal('1.100000000000000088817841970012523233890533447265625') >>> Fraction(1.1) Fraction(2476979795053773, 2251799813685248) Another useful change for the *note decimal: 36. module is that the ‘Context.clamp’ attribute is now public. This is useful in creating contexts that correspond to the decimal interchange formats specified in IEEE 754 (see bpo-8540(6)). (Contributed by Mark Dickinson and Raymond Hettinger.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8188 (2) https://bugs.python.org/issue8257 (3) https://bugs.python.org/issue2531 (4) https://bugs.python.org/issue8188 (5) https://bugs.python.org/issue8294 (6) https://bugs.python.org/issue8540  File: python.info, Node: ftp, Next: popen, Prev: decimal and fractions, Up: New Improved and Deprecated Modules 1.7.9.16 ftp ............ The *note ftplib.FTP: 2f0. class now supports the context management protocol to unconditionally consume *note socket.error: 995. exceptions and to close the FTP connection when done: >>> from ftplib import FTP >>> with FTP("ftp1.at.proftpd.org") as ftp: ftp.login() ftp.dir() '230 Anonymous login ok, restrictions apply.' dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 . dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 .. dr-xr-xr-x 5 ftp ftp 4096 May 6 10:43 CentOS dr-xr-xr-x 3 ftp ftp 18 Jul 10 2008 Fedora Other file-like objects such as *note mmap.mmap: 1ec. and *note fileinput.input(): 2ad. also grew auto-closing context managers: with fileinput.input(files=('log1.txt', 'log2.txt')) as f: for line in f: process(line) (Contributed by Tarek Ziadé and Giampaolo Rodolà in bpo-4972(1), and by Georg Brandl in bpo-8046(2) and bpo-1286(3).) The *note FTP_TLS: a03. class now accepts a `context' parameter, which is a *note ssl.SSLContext: 3e4. object allowing bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. (Contributed by Giampaolo Rodolà; bpo-8806(4).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4972 (2) https://bugs.python.org/issue8046 (3) https://bugs.python.org/issue1286 (4) https://bugs.python.org/issue8806  File: python.info, Node: popen, Next: select<3>, Prev: ftp, Up: New Improved and Deprecated Modules 1.7.9.17 popen .............. The *note os.popen(): 2a9. and *note subprocess.Popen(): 2b9. functions now support *note with: 6e9. statements for auto-closing of the file descriptors. (Contributed by Antoine Pitrou and Brian Curtin in bpo-7461(1) and bpo-10554(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue7461 (2) https://bugs.python.org/issue10554  File: python.info, Node: select<3>, Next: gzip and zipfile, Prev: popen, Up: New Improved and Deprecated Modules 1.7.9.18 select ............... The *note select: e5. module now exposes a new, constant attribute, *note PIPE_BUF: b86, which gives the minimum number of bytes which are guaranteed not to block when *note select.select(): 673. says a pipe is ready for writing. >>> import select >>> select.PIPE_BUF 512 (Available on Unix systems. Patch by Sébastien Sablé in bpo-9862(1)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9862  File: python.info, Node: gzip and zipfile, Next: tarfile<5>, Prev: select<3>, Up: New Improved and Deprecated Modules 1.7.9.19 gzip and zipfile ......................... *note gzip.GzipFile: 6dd. now implements the *note io.BufferedIOBase: 588. *note abstract base class: b33. (except for ‘truncate()’). It also has a *note peek(): b88. method and supports unseekable as well as zero-padded file objects. The *note gzip: 8c. module also gains the *note compress(): 1d1. and *note decompress(): b89. functions for easier in-memory compression and decompression. Keep in mind that text needs to be encoded as *note bytes: 331. before compressing and decompressing: >>> import gzip >>> s = 'Three shall be the number thou shalt count, ' >>> s += 'and the number of the counting shall be three' >>> b = s.encode() # convert to utf-8 >>> len(b) 89 >>> c = gzip.compress(b) >>> len(c) 77 >>> gzip.decompress(c).decode()[:42] # decompress and convert to text 'Three shall be the number thou shalt count' (Contributed by Anand B. Pillai in bpo-3488(1); and by Antoine Pitrou, Nir Aides and Brian Curtin in bpo-9962(2), bpo-1675951(3), bpo-7471(4) and bpo-2846(5).) Also, the ‘zipfile.ZipExtFile’ class was reworked internally to represent files stored inside an archive. The new implementation is significantly faster and can be wrapped in an *note io.BufferedReader: b8a. object for more speedups. It also solves an issue where interleaved calls to `read' and `readline' gave the wrong results. (Patch submitted by Nir Aides in bpo-7610(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue3488 (2) https://bugs.python.org/issue9962 (3) https://bugs.python.org/issue1675951 (4) https://bugs.python.org/issue7471 (5) https://bugs.python.org/issue2846 (6) https://bugs.python.org/issue7610  File: python.info, Node: tarfile<5>, Next: hashlib<3>, Prev: gzip and zipfile, Up: New Improved and Deprecated Modules 1.7.9.20 tarfile ................ The *note TarFile: b8c. class can now be used as a context manager. In addition, its *note add(): 47c. method has a new option, `filter', that controls which files are added to the archive and allows the file metadata to be edited. The new `filter' option replaces the older, less flexible `exclude' parameter which is now deprecated. If specified, the optional `filter' parameter needs to be a *note keyword argument: 5c4. The user-supplied filter function accepts a *note TarInfo: b8d. object and returns an updated *note TarInfo: b8d. object, or if it wants the file to be excluded, the function can return ‘None’: >>> import tarfile, glob >>> def myfilter(tarinfo): ... if tarinfo.isfile(): # only save real files ... tarinfo.uname = 'monty' # redact the user name ... return tarinfo >>> with tarfile.open(name='myarchive.tar.gz', mode='w:gz') as tf: ... for filename in glob.glob('*.txt'): ... tf.add(filename, filter=myfilter) ... tf.list() -rw-r--r-- monty/501 902 2011-01-26 17:59:11 annotations.txt -rw-r--r-- monty/501 123 2011-01-26 17:59:11 general_questions.txt -rw-r--r-- monty/501 3514 2011-01-26 17:59:11 prion.txt -rw-r--r-- monty/501 124 2011-01-26 17:59:11 py_todo.txt -rw-r--r-- monty/501 1399 2011-01-26 17:59:11 semaphore_notes.txt (Proposed by Tarek Ziadé and implemented by Lars Gustäbel in bpo-6856(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6856  File: python.info, Node: hashlib<3>, Next: ast<3>, Prev: tarfile<5>, Up: New Improved and Deprecated Modules 1.7.9.21 hashlib ................ The *note hashlib: 8d. module has two new constant attributes listing the hashing algorithms guaranteed to be present in all implementations and those available on the current implementation: >>> import hashlib >>> hashlib.algorithms_guaranteed {'sha1', 'sha224', 'sha384', 'sha256', 'sha512', 'md5'} >>> hashlib.algorithms_available {'md2', 'SHA256', 'SHA512', 'dsaWithSHA', 'mdc2', 'SHA224', 'MD4', 'sha256', 'sha512', 'ripemd160', 'SHA1', 'MDC2', 'SHA', 'SHA384', 'MD2', 'ecdsa-with-SHA1','md4', 'md5', 'sha1', 'DSA-SHA', 'sha224', 'dsaEncryption', 'DSA', 'RIPEMD160', 'sha', 'MD5', 'sha384'} (Suggested by Carl Chenet in bpo-7418(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue7418  File: python.info, Node: ast<3>, Next: os<8>, Prev: hashlib<3>, Up: New Improved and Deprecated Modules 1.7.9.22 ast ............ The *note ast: 8. module has a wonderful a general-purpose tool for safely evaluating expression strings using the Python literal syntax. The *note ast.literal_eval(): 4a5. function serves as a secure alternative to the builtin *note eval(): b90. function which is easily abused. Python 3.2 adds *note bytes: 331. and *note set: b6f. literals to the list of supported types: strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and ‘None’. >>> from ast import literal_eval >>> request = "{'req': 3, 'func': 'pow', 'args': (2, 0.5)}" >>> literal_eval(request) {'args': (2, 0.5), 'req': 3, 'func': 'pow'} >>> request = "os.system('do something harmful')" >>> literal_eval(request) Traceback (most recent call last): ... ValueError: malformed node or string: <_ast.Call object at 0x101739a10> (Implemented by Benjamin Peterson and Georg Brandl.)  File: python.info, Node: os<8>, Next: shutil<5>, Prev: ast<3>, Up: New Improved and Deprecated Modules 1.7.9.23 os ........... Different operating systems use various encodings for filenames and environment variables. The *note os: c4. module provides two new functions, *note fsencode(): 4ef. and *note fsdecode(): 4ee, for encoding and decoding filenames: >>> import os >>> filename = 'Sehenswürdigkeiten' >>> os.fsencode(filename) b'Sehensw\xc3\xbcrdigkeiten' Some operating systems allow direct access to encoded bytes in the environment. If so, the *note os.supports_bytes_environ: b92. constant will be true. For direct access to encoded environment variables (if available), use the new *note os.getenvb(): b93. function or use *note os.environb: b94. which is a bytes version of *note os.environ: b37. (Contributed by Victor Stinner.)  File: python.info, Node: shutil<5>, Next: sqlite3<6>, Prev: os<8>, Up: New Improved and Deprecated Modules 1.7.9.24 shutil ............... The *note shutil.copytree(): 21a. function has two new options: * `ignore_dangling_symlinks': when ‘symlinks=False’ so that the function copies a file pointed to by a symlink, not the symlink itself. This option will silence the error raised if the file doesn’t exist. * `copy_function': is a callable that will be used to copy files. *note shutil.copy2(): 25a. is used by default. (Contributed by Tarek Ziadé.) In addition, the *note shutil: e9. module now supports *note archiving operations: b96. for zipfiles, uncompressed tarfiles, gzipped tarfiles, and bzipped tarfiles. And there are functions for registering additional archiving file formats (such as xz compressed tarfiles or custom formats). The principal functions are *note make_archive(): 21b. and *note unpack_archive(): b97. By default, both operate on the current directory (which can be set by *note os.chdir(): a3f.) and on any sub-directories. The archive filename needs to be specified with a full pathname. The archiving step is non-destructive (the original files are left unchanged). >>> import shutil, pprint >>> os.chdir('mydata') # change to the source directory >>> f = shutil.make_archive('/var/backup/mydata', ... 'zip') # archive the current directory >>> f # show the name of archive '/var/backup/mydata.zip' >>> os.chdir('tmp') # change to an unpacking >>> shutil.unpack_archive('/var/backup/mydata.zip') # recover the data >>> pprint.pprint(shutil.get_archive_formats()) # display known formats [('bztar', "bzip2'ed tar-file"), ('gztar', "gzip'ed tar-file"), ('tar', 'uncompressed tar file'), ('zip', 'ZIP file')] >>> shutil.register_archive_format( # register a new archive format ... name='xz', ... function=xz.compress, # callable archiving function ... extra_args=[('level', 8)], # arguments to the function ... description='xz compression' ... ) (Contributed by Tarek Ziadé.)  File: python.info, Node: sqlite3<6>, Next: html<3>, Prev: shutil<5>, Up: New Improved and Deprecated Modules 1.7.9.25 sqlite3 ................ The *note sqlite3: f2. module was updated to pysqlite version 2.6.0. It has two new capabilities. * The ‘sqlite3.Connection.in_transit’ attribute is true if there is an active transaction for uncommitted changes. * The *note sqlite3.Connection.enable_load_extension(): b99. and *note sqlite3.Connection.load_extension(): b9a. methods allows you to load SQLite extensions from “.so” files. One well-known extension is the fulltext-search extension distributed with SQLite. (Contributed by R. David Murray and Shashwat Anand; bpo-8845(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8845  File: python.info, Node: html<3>, Next: socket<8>, Prev: sqlite3<6>, Up: New Improved and Deprecated Modules 1.7.9.26 html ............. A new *note html: 90. module was introduced with only a single function, *note escape(): 934, which is used for escaping reserved characters from HTML markup: >>> import html >>> html.escape('x > 2 && x < 7') 'x > 2 && x < 7'  File: python.info, Node: socket<8>, Next: ssl<9>, Prev: html<3>, Up: New Improved and Deprecated Modules 1.7.9.27 socket ............... The *note socket: ef. module has two new improvements. * Socket objects now have a *note detach(): b9d. method which puts the socket into closed state without actually closing the underlying file descriptor. The latter can then be reused for other purposes. (Added by Antoine Pitrou; bpo-8524(1).) * *note socket.create_connection(): b9e. now supports the context management protocol to unconditionally consume *note socket.error: 995. exceptions and to close the socket when done. (Contributed by Giampaolo Rodolà; bpo-9794(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8524 (2) https://bugs.python.org/issue9794  File: python.info, Node: ssl<9>, Next: nntp, Prev: socket<8>, Up: New Improved and Deprecated Modules 1.7.9.28 ssl ............ The *note ssl: f3. module added a number of features to satisfy common requirements for secure (encrypted, authenticated) internet connections: * A new class, *note SSLContext: 3e4, serves as a container for persistent SSL data, such as protocol settings, certificates, private keys, and various other options. It includes a *note wrap_socket(): 3e5. for creating an SSL socket from an SSL context. * A new function, *note ssl.match_hostname(): 3dc, supports server identity verification for higher-level protocols by implementing the rules of HTTPS (from RFC 2818(1)) which are also suitable for other protocols. * The *note ssl.wrap_socket(): 46f. constructor function now takes a `ciphers' argument. The `ciphers' string lists the allowed encryption algorithms using the format described in the OpenSSL documentation(2). * When linked against recent versions of OpenSSL, the *note ssl: f3. module now supports the Server Name Indication extension to the TLS protocol, allowing multiple “virtual hosts” using different certificates on a single IP port. This extension is only supported in client mode, and is activated by passing the `server_hostname' argument to *note ssl.SSLContext.wrap_socket(): 3e5. * Various options have been added to the *note ssl: f3. module, such as *note OP_NO_SSLv2: ba0. which disables the insecure and obsolete SSLv2 protocol. * The extension now loads all the OpenSSL ciphers and digest algorithms. If some SSL certificates cannot be verified, they are reported as an “unknown algorithm” error. * The version of OpenSSL being used is now accessible using the module attributes *note ssl.OPENSSL_VERSION: ba1. (a string), *note ssl.OPENSSL_VERSION_INFO: ba2. (a 5-tuple), and *note ssl.OPENSSL_VERSION_NUMBER: ba3. (an integer). (Contributed by Antoine Pitrou in bpo-8850(3), bpo-1589(4), bpo-8322(5), bpo-5639(6), bpo-4870(7), bpo-8484(8), and bpo-8321(9).) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2818.html (2) https://www.openssl.org/docs/manmaster/man1/ciphers.html#CIPHER-LIST-FORMAT (3) https://bugs.python.org/issue8850 (4) https://bugs.python.org/issue1589 (5) https://bugs.python.org/issue8322 (6) https://bugs.python.org/issue5639 (7) https://bugs.python.org/issue4870 (8) https://bugs.python.org/issue8484 (9) https://bugs.python.org/issue8321  File: python.info, Node: nntp, Next: certificates, Prev: ssl<9>, Up: New Improved and Deprecated Modules 1.7.9.29 nntp ............. The *note nntplib: c0. module has a revamped implementation with better bytes and text semantics as well as more practical APIs. These improvements break compatibility with the nntplib version in Python 3.1, which was partly dysfunctional in itself. Support for secure connections through both implicit (using *note nntplib.NNTP_SSL: ba5.) and explicit (using *note nntplib.NNTP.starttls(): ba6.) TLS has also been added. (Contributed by Antoine Pitrou in bpo-9360(1) and Andrew Vant in bpo-1926(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9360 (2) https://bugs.python.org/issue1926  File: python.info, Node: certificates, Next: imaplib<3>, Prev: nntp, Up: New Improved and Deprecated Modules 1.7.9.30 certificates ..................... *note http.client.HTTPSConnection: 393, *note urllib.request.HTTPSHandler: ba8. and *note urllib.request.urlopen(): 78c. now take optional arguments to allow for server certificate checking against a set of Certificate Authorities, as recommended in public uses of HTTPS. (Added by Antoine Pitrou, bpo-9003(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9003  File: python.info, Node: imaplib<3>, Next: http client<4>, Prev: certificates, Up: New Improved and Deprecated Modules 1.7.9.31 imaplib ................ Support for explicit TLS on standard IMAP4 connections has been added through the new *note imaplib.IMAP4.starttls: baa. method. (Contributed by Lorenzo M. Catucci and Antoine Pitrou, bpo-4471(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4471  File: python.info, Node: http client<4>, Next: unittest<6>, Prev: imaplib<3>, Up: New Improved and Deprecated Modules 1.7.9.32 http.client .................... There were a number of small API improvements in the *note http.client: 94. module. The old-style HTTP 0.9 simple responses are no longer supported and the `strict' parameter is deprecated in all classes. The *note HTTPConnection: 392. and *note HTTPSConnection: 393. classes now have a `source_address' parameter for a (host, port) tuple indicating where the HTTP connection is made from. Support for certificate checking and HTTPS virtual hosts were added to *note HTTPSConnection: 393. The *note request(): 54f. method on connection objects allowed an optional `body' argument so that a *note file object: b42. could be used to supply the content of the request. Conveniently, the `body' argument now also accepts an *note iterable: bac. object so long as it includes an explicit ‘Content-Length’ header. This extended interface is much more flexible than before. To establish an HTTPS connection through a proxy server, there is a new *note set_tunnel(): bad. method that sets the host and port for HTTP Connect tunneling. To match the behavior of *note http.server: 97, the HTTP client library now also encodes headers with ISO-8859-1 (Latin-1) encoding. It was already doing that for incoming headers, so now the behavior is consistent for both incoming and outgoing traffic. (See work by Armin Ronacher in bpo-10980(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10980  File: python.info, Node: unittest<6>, Next: random<2>, Prev: http client<4>, Up: New Improved and Deprecated Modules 1.7.9.33 unittest ................. The unittest module has a number of improvements supporting test discovery for packages, easier experimentation at the interactive prompt, new testcase methods, improved diagnostic messages for test failures, and better method names. * The command-line call ‘python -m unittest’ can now accept file paths instead of module names for running specific tests (bpo-10620(1)). The new test discovery can find tests within packages, locating any test importable from the top-level directory. The top-level directory can be specified with the ‘-t’ option, a pattern for matching files with ‘-p’, and a directory to start discovery with ‘-s’: $ python -m unittest discover -s my_proj_dir -p _test.py (Contributed by Michael Foord.) * Experimentation at the interactive prompt is now easier because the ‘unittest.case.TestCase’ class can now be instantiated without arguments: >>> from unittest import TestCase >>> TestCase().assertEqual(pow(2, 3), 8) (Contributed by Michael Foord.) * The *note unittest: 11b. module has two new methods, *note assertWarns(): abc. and *note assertWarnsRegex(): abd. to verify that a given warning type is triggered by the code under test: with self.assertWarns(DeprecationWarning): legacy_function('XYZ') (Contributed by Antoine Pitrou, bpo-9754(2).) Another new method, *note assertCountEqual(): baf. is used to compare two iterables to determine if their element counts are equal (whether the same elements are present with the same number of occurrences regardless of order): def test_anagram(self): self.assertCountEqual('algorithm', 'logarithm') (Contributed by Raymond Hettinger.) * A principal feature of the unittest module is an effort to produce meaningful diagnostics when a test fails. When possible, the failure is recorded along with a diff of the output. This is especially helpful for analyzing log files of failed test runs. However, since diffs can sometime be voluminous, there is a new *note maxDiff: bb0. attribute that sets maximum length of diffs displayed. * In addition, the method names in the module have undergone a number of clean-ups. For example, *note assertRegex(): bb1. is the new name for ‘assertRegexpMatches()’ which was misnamed because the test uses *note re.search(): bb2, not *note re.match(): bb3. Other methods using regular expressions are now named using short form “Regex” in preference to “Regexp” – this matches the names used in other unittest implementations, matches Python’s old name for the *note re: dd. module, and it has unambiguous camel-casing. (Contributed by Raymond Hettinger and implemented by Ezio Melotti.) * To improve consistency, some long-standing method aliases are being deprecated in favor of the preferred names: Old Name Preferred Name ----------------------------------------------------------------------- ‘assert_()’ *note assertTrue(): bb4. ‘assertEquals()’ *note assertEqual(): bb5. ‘assertNotEquals()’ *note assertNotEqual(): bb6. ‘assertAlmostEquals()’ *note assertAlmostEqual(): bb7. ‘assertNotAlmostEquals()’ *note assertNotAlmostEqual(): bb8. Likewise, the ‘TestCase.fail*’ methods deprecated in Python 3.1 are expected to be removed in Python 3.3. Also see the *note Deprecated aliases: bb9. section in the *note unittest: 11b. documentation. (Contributed by Ezio Melotti; bpo-9424(3).) * The ‘assertDictContainsSubset()’ method was deprecated because it was misimplemented with the arguments in the wrong order. This created hard-to-debug optical illusions where tests like ‘TestCase().assertDictContainsSubset({'a':1, 'b':2}, {'a':1})’ would fail. (Contributed by Raymond Hettinger.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10620 (2) https://bugs.python.org/issue9754 (3) https://bugs.python.org/issue9424  File: python.info, Node: random<2>, Next: poplib<3>, Prev: unittest<6>, Up: New Improved and Deprecated Modules 1.7.9.34 random ............... The integer methods in the *note random: dc. module now do a better job of producing uniform distributions. Previously, they computed selections with ‘int(n*random())’ which had a slight bias whenever `n' was not a power of two. Now, multiple selections are made from a range up to the next power of two and a selection is kept only when it falls within the range ‘0 <= x < n’. The functions and methods affected are *note randrange(): bbb, *note randint(): bbc, *note choice(): bbd, *note shuffle(): bbe. and *note sample(): bbf. (Contributed by Raymond Hettinger; bpo-9025(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9025  File: python.info, Node: poplib<3>, Next: asyncore<2>, Prev: random<2>, Up: New Improved and Deprecated Modules 1.7.9.35 poplib ............... *note POP3_SSL: bc1. class now accepts a `context' parameter, which is a *note ssl.SSLContext: 3e4. object allowing bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. (Contributed by Giampaolo Rodolà; bpo-8807(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8807  File: python.info, Node: asyncore<2>, Next: tempfile<2>, Prev: poplib<3>, Up: New Improved and Deprecated Modules 1.7.9.36 asyncore ................. *note asyncore.dispatcher: bc3. now provides a *note handle_accepted(): bc4. method returning a ‘(sock, addr)’ pair which is called when a connection has actually been established with a new remote endpoint. This is supposed to be used as a replacement for old *note handle_accept(): bc5. and avoids the user to call *note accept(): bc6. directly. (Contributed by Giampaolo Rodolà; bpo-6706(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6706  File: python.info, Node: tempfile<2>, Next: inspect<6>, Prev: asyncore<2>, Up: New Improved and Deprecated Modules 1.7.9.37 tempfile ................. The *note tempfile: 103. module has a new context manager, *note TemporaryDirectory: bc8. which provides easy deterministic cleanup of temporary directories: with tempfile.TemporaryDirectory() as tmpdirname: print('created temporary dir:', tmpdirname) (Contributed by Neil Schemenauer and Nick Coghlan; bpo-5178(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5178  File: python.info, Node: inspect<6>, Next: pydoc<5>, Prev: tempfile<2>, Up: New Improved and Deprecated Modules 1.7.9.38 inspect ................ * The *note inspect: a0. module has a new function *note getgeneratorstate(): bca. to easily identify the current state of a generator-iterator: >>> from inspect import getgeneratorstate >>> def gen(): ... yield 'demo' >>> g = gen() >>> getgeneratorstate(g) 'GEN_CREATED' >>> next(g) 'demo' >>> getgeneratorstate(g) 'GEN_SUSPENDED' >>> next(g, None) >>> getgeneratorstate(g) 'GEN_CLOSED' (Contributed by Rodolpho Eckhardt and Nick Coghlan, bpo-10220(1).) * To support lookups without the possibility of activating a dynamic attribute, the *note inspect: a0. module has a new function, *note getattr_static(): bcb. Unlike *note hasattr(): 447, this is a true read-only search, guaranteed not to change state while it is searching: >>> class A: ... @property ... def f(self): ... print('Running') ... return 10 ... >>> a = A() >>> getattr(a, 'f') Running 10 >>> inspect.getattr_static(a, 'f') (Contributed by Michael Foord.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10220  File: python.info, Node: pydoc<5>, Next: dis<3>, Prev: inspect<6>, Up: New Improved and Deprecated Modules 1.7.9.39 pydoc .............. The *note pydoc: d9. module now provides a much-improved Web server interface, as well as a new command-line option ‘-b’ to automatically open a browser window to display that server: $ pydoc3.2 -b (Contributed by Ron Adam; bpo-2001(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue2001  File: python.info, Node: dis<3>, Next: dbm<6>, Prev: pydoc<5>, Up: New Improved and Deprecated Modules 1.7.9.40 dis ............ The *note dis: 38. module gained two new functions for inspecting code, *note code_info(): bce. and *note show_code(): 832. Both provide detailed code object information for the supplied function, method, source code string or code object. The former returns a string and the latter prints it: >>> import dis, random >>> dis.show_code(random.choice) Name: choice Filename: /Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/random.py Argument count: 2 Kw-only arguments: 0 Number of locals: 3 Stack size: 11 Flags: OPTIMIZED, NEWLOCALS, NOFREE Constants: 0: 'Choose a random element from a non-empty sequence.' 1: 'Cannot choose from an empty sequence' Names: 0: _randbelow 1: len 2: ValueError 3: IndexError Variable names: 0: self 1: seq 2: i In addition, the *note dis(): 384. function now accepts string arguments so that the common idiom ‘dis(compile(s, '', 'eval'))’ can be shortened to ‘dis(s)’: >>> dis('3*x+1 if x%2==1 else x//2') 1 0 LOAD_NAME 0 (x) 3 LOAD_CONST 0 (2) 6 BINARY_MODULO 7 LOAD_CONST 1 (1) 10 COMPARE_OP 2 (==) 13 POP_JUMP_IF_FALSE 28 16 LOAD_CONST 2 (3) 19 LOAD_NAME 0 (x) 22 BINARY_MULTIPLY 23 LOAD_CONST 1 (1) 26 BINARY_ADD 27 RETURN_VALUE >> 28 LOAD_NAME 0 (x) 31 LOAD_CONST 0 (2) 34 BINARY_FLOOR_DIVIDE 35 RETURN_VALUE Taken together, these improvements make it easier to explore how CPython is implemented and to see for yourself what the language syntax does under-the-hood. (Contributed by Nick Coghlan in bpo-9147(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9147  File: python.info, Node: dbm<6>, Next: ctypes<2>, Prev: dis<3>, Up: New Improved and Deprecated Modules 1.7.9.41 dbm ............ All database modules now support the ‘get()’ and ‘setdefault()’ methods. (Suggested by Ray Allen in bpo-9523(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9523  File: python.info, Node: ctypes<2>, Next: site<2>, Prev: dbm<6>, Up: New Improved and Deprecated Modules 1.7.9.42 ctypes ............... A new type, *note ctypes.c_ssize_t: bd1. represents the C ‘ssize_t’ datatype.  File: python.info, Node: site<2>, Next: sysconfig<2>, Prev: ctypes<2>, Up: New Improved and Deprecated Modules 1.7.9.43 site ............. The *note site: eb. module has three new functions useful for reporting on the details of a given Python installation. * *note getsitepackages(): bd3. lists all global site-packages directories. * *note getuserbase(): bd4. reports on the user’s base directory where data can be stored. * *note getusersitepackages(): bd5. reveals the user-specific site-packages directory path. >>> import site >>> site.getsitepackages() ['/Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/site-packages', '/Library/Frameworks/Python.framework/Versions/3.2/lib/site-python', '/Library/Python/3.2/site-packages'] >>> site.getuserbase() '/Users/raymondhettinger/Library/Python/3.2' >>> site.getusersitepackages() '/Users/raymondhettinger/Library/Python/3.2/lib/python/site-packages' Conveniently, some of site’s functionality is accessible directly from the command-line: $ python -m site --user-base /Users/raymondhettinger/.local $ python -m site --user-site /Users/raymondhettinger/.local/lib/python3.2/site-packages (Contributed by Tarek Ziadé in bpo-6693(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6693  File: python.info, Node: sysconfig<2>, Next: pdb<5>, Prev: site<2>, Up: New Improved and Deprecated Modules 1.7.9.44 sysconfig .................. The new *note sysconfig: fe. module makes it straightforward to discover installation paths and configuration variables that vary across platforms and installations. The module offers access simple access functions for platform and version information: * *note get_platform(): bd7. returning values like `linux-i586' or `macosx-10.6-ppc'. * *note get_python_version(): bd8. returns a Python version string such as “3.2”. It also provides access to the paths and variables corresponding to one of seven named schemes used by *note distutils: 39. Those include `posix_prefix', `posix_home', `posix_user', `nt', `nt_user', `os2', `os2_home': * *note get_paths(): bd9. makes a dictionary containing installation paths for the current installation scheme. * *note get_config_vars(): 965. returns a dictionary of platform specific variables. There is also a convenient command-line interface: C:\Python32>python -m sysconfig Platform: "win32" Python version: "3.2" Current installation scheme: "nt" Paths: data = "C:\Python32" include = "C:\Python32\Include" platinclude = "C:\Python32\Include" platlib = "C:\Python32\Lib\site-packages" platstdlib = "C:\Python32\Lib" purelib = "C:\Python32\Lib\site-packages" scripts = "C:\Python32\Scripts" stdlib = "C:\Python32\Lib" Variables: BINDIR = "C:\Python32" BINLIBDEST = "C:\Python32\Lib" EXE = ".exe" INCLUDEPY = "C:\Python32\Include" LIBDEST = "C:\Python32\Lib" SO = ".pyd" VERSION = "32" abiflags = "" base = "C:\Python32" exec_prefix = "C:\Python32" platbase = "C:\Python32" prefix = "C:\Python32" projectbase = "C:\Python32" py_version = "3.2" py_version_nodot = "32" py_version_short = "3.2" srcdir = "C:\Python32" userbase = "C:\Documents and Settings\Raymond\Application Data\Python" (Moved out of Distutils by Tarek Ziadé.)  File: python.info, Node: pdb<5>, Next: configparser<2>, Prev: sysconfig<2>, Up: New Improved and Deprecated Modules 1.7.9.45 pdb ............ The *note pdb: c9. debugger module gained a number of usability improvements: * ‘pdb.py’ now has a ‘-c’ option that executes commands as given in a ‘.pdbrc’ script file. * A ‘.pdbrc’ script file can contain ‘continue’ and ‘next’ commands that continue debugging. * The ‘Pdb’ class constructor now accepts a `nosigint' argument. * New commands: ‘l(list)’, ‘ll(long list)’ and ‘source’ for listing source code. * New commands: ‘display’ and ‘undisplay’ for showing or hiding the value of an expression if it has changed. * New command: ‘interact’ for starting an interactive interpreter containing the global and local names found in the current scope. * Breakpoints can be cleared by breakpoint number. (Contributed by Georg Brandl, Antonio Cuni and Ilya Sandler.)  File: python.info, Node: configparser<2>, Next: urllib parse<2>, Prev: pdb<5>, Up: New Improved and Deprecated Modules 1.7.9.46 configparser ..................... The *note configparser: 23. module was modified to improve usability and predictability of the default parser and its supported INI syntax. The old ‘ConfigParser’ class was removed in favor of ‘SafeConfigParser’ which has in turn been renamed to *note ConfigParser: 4aa. Support for inline comments is now turned off by default and section or option duplicates are not allowed in a single configuration source. Config parsers gained a new API based on the mapping protocol: >>> parser = ConfigParser() >>> parser.read_string(""" ... [DEFAULT] ... location = upper left ... visible = yes ... editable = no ... color = blue ... ... [main] ... title = Main Menu ... color = green ... ... [options] ... title = Options ... """) >>> parser['main']['color'] 'green' >>> parser['main']['editable'] 'no' >>> section = parser['options'] >>> section['title'] 'Options' >>> section['title'] = 'Options (editable: %(editable)s)' >>> section['title'] 'Options (editable: no)' The new API is implemented on top of the classical API, so custom parser subclasses should be able to use it without modifications. The INI file structure accepted by config parsers can now be customized. Users can specify alternative option/value delimiters and comment prefixes, change the name of the `DEFAULT' section or switch the interpolation syntax. There is support for pluggable interpolation including an additional interpolation handler *note ExtendedInterpolation: bdc.: >>> parser = ConfigParser(interpolation=ExtendedInterpolation()) >>> parser.read_dict({'buildout': {'directory': '/home/ambv/zope9'}, ... 'custom': {'prefix': '/usr/local'}}) >>> parser.read_string(""" ... [buildout] ... parts = ... zope9 ... instance ... find-links = ... ${buildout:directory}/downloads/dist ... ... [zope9] ... recipe = plone.recipe.zope9install ... location = /opt/zope ... ... [instance] ... recipe = plone.recipe.zope9instance ... zope9-location = ${zope9:location} ... zope-conf = ${custom:prefix}/etc/zope.conf ... """) >>> parser['buildout']['find-links'] '\n/home/ambv/zope9/downloads/dist' >>> parser['instance']['zope-conf'] '/usr/local/etc/zope.conf' >>> instance = parser['instance'] >>> instance['zope-conf'] '/usr/local/etc/zope.conf' >>> instance['zope9-location'] '/opt/zope' A number of smaller features were also introduced, like support for specifying encoding in read operations, specifying fallback values for get-functions, or reading directly from dictionaries and strings. (All changes contributed by Łukasz Langa.)  File: python.info, Node: urllib parse<2>, Next: mailbox, Prev: configparser<2>, Up: New Improved and Deprecated Modules 1.7.9.47 urllib.parse ..................... A number of usability improvements were made for the *note urllib.parse: 11f. module. The *note urlparse(): 5fa. function now supports IPv6(1) addresses as described in RFC 2732(2): >>> import urllib.parse >>> urllib.parse.urlparse('http://[dead:beef:cafe:5417:affe:8FA3:deaf:feed]/foo/') ParseResult(scheme='http', netloc='[dead:beef:cafe:5417:affe:8FA3:deaf:feed]', path='/foo/', params='', query='', fragment='') The *note urldefrag(): bde. function now returns a *note named tuple: aa3.: >>> r = urllib.parse.urldefrag('http://python.org/about/#target') >>> r DefragResult(url='http://python.org/about/', fragment='target') >>> r[0] 'http://python.org/about/' >>> r.fragment 'target' And, the *note urlencode(): 78b. function is now much more flexible, accepting either a string or bytes type for the `query' argument. If it is a string, then the `safe', `encoding', and `error' parameters are sent to *note quote_plus(): bdf. for encoding: >>> urllib.parse.urlencode([ ... ('type', 'telenovela'), ... ('name', '¿Dónde Está Elisa?')], ... encoding='latin-1') 'type=telenovela&name=%BFD%F3nde+Est%E1+Elisa%3F' As detailed in *note Parsing ASCII Encoded Bytes: be0, all the *note urllib.parse: 11f. functions now accept ASCII-encoded byte strings as input, so long as they are not mixed with regular strings. If ASCII-encoded byte strings are given as parameters, the return types will also be an ASCII-encoded byte strings: >>> urllib.parse.urlparse(b'http://www.python.org:80/about/') ParseResultBytes(scheme=b'http', netloc=b'www.python.org:80', path=b'/about/', params=b'', query=b'', fragment=b'') (Work by Nick Coghlan, Dan Mahn, and Senthil Kumaran in bpo-2987(3), bpo-5468(4), and bpo-9873(5).) ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/IPv6 (2) https://tools.ietf.org/html/rfc2732.html (3) https://bugs.python.org/issue2987 (4) https://bugs.python.org/issue5468 (5) https://bugs.python.org/issue9873  File: python.info, Node: mailbox, Next: turtledemo, Prev: urllib parse<2>, Up: New Improved and Deprecated Modules 1.7.9.48 mailbox ................ Thanks to a concerted effort by R. David Murray, the *note mailbox: ae. module has been fixed for Python 3.2. The challenge was that mailbox had been originally designed with a text interface, but email messages are best represented with *note bytes: 331. because various parts of a message may have different encodings. The solution harnessed the *note email: 69. package’s binary support for parsing arbitrary email messages. In addition, the solution required a number of API changes. As expected, the *note add(): be2. method for *note mailbox.Mailbox: be3. objects now accepts binary input. *note StringIO: 82d. and text file input are deprecated. Also, string input will fail early if non-ASCII characters are used. Previously it would fail when the email was processed in a later step. There is also support for binary output. The *note get_file(): be4. method now returns a file in the binary mode (where it used to incorrectly set the file to text-mode). There is also a new *note get_bytes(): be5. method that returns a *note bytes: 331. representation of a message corresponding to a given `key'. It is still possible to get non-binary output using the old API’s *note get_string(): be6. method, but that approach is not very useful. Instead, it is best to extract messages from a *note Message: be7. object or to load them from binary input. (Contributed by R. David Murray, with efforts from Steffen Daode Nurpmeso and an initial patch by Victor Stinner in bpo-9124(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue9124  File: python.info, Node: turtledemo, Prev: mailbox, Up: New Improved and Deprecated Modules 1.7.9.49 turtledemo ................... The demonstration code for the *note turtle: 116. module was moved from the `Demo' directory to main library. It includes over a dozen sample scripts with lively displays. Being on *note sys.path: 488, it can now be run directly from the command-line: $ python -m turtledemo (Moved from the Demo directory by Alexander Belopolsky in bpo-10199(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue10199  File: python.info, Node: Multi-threading, Next: Optimizations<6>, Prev: New Improved and Deprecated Modules, Up: What’s New In Python 3 2 1.7.10 Multi-threading ---------------------- * The mechanism for serializing execution of concurrently running Python threads (generally known as the *note GIL: bea. or Global Interpreter Lock) has been rewritten. Among the objectives were more predictable switching intervals and reduced overhead due to lock contention and the number of ensuing system calls. The notion of a “check interval” to allow thread switches has been abandoned and replaced by an absolute duration expressed in seconds. This parameter is tunable through *note sys.setswitchinterval(): beb. It currently defaults to 5 milliseconds. Additional details about the implementation can be read from a python-dev mailing-list message(1) (however, “priority requests” as exposed in this message have not been kept for inclusion). (Contributed by Antoine Pitrou.) * Regular and recursive locks now accept an optional `timeout' argument to their *note acquire(): 76c. method. (Contributed by Antoine Pitrou; bpo-7316(2).) * Similarly, *note threading.Semaphore.acquire(): bec. also gained a `timeout' argument. (Contributed by Torsten Landschoff; bpo-850728(3).) * Regular and recursive lock acquisitions can now be interrupted by signals on platforms using Pthreads. This means that Python programs that deadlock while acquiring locks can be successfully killed by repeatedly sending SIGINT to the process (by pressing ‘Ctrl+C’ in most shells). (Contributed by Reid Kleckner; bpo-8844(4).) ---------- Footnotes ---------- (1) https://mail.python.org/pipermail/python-dev/2009-October/093321.html (2) https://bugs.python.org/issue7316 (3) https://bugs.python.org/issue850728 (4) https://bugs.python.org/issue8844  File: python.info, Node: Optimizations<6>, Next: Unicode, Prev: Multi-threading, Up: What’s New In Python 3 2 1.7.11 Optimizations -------------------- A number of small performance enhancements have been added: * Python’s peephole optimizer now recognizes patterns such ‘x in {1, 2, 3}’ as being a test for membership in a set of constants. The optimizer recasts the *note set: b6f. as a *note frozenset: bee. and stores the pre-built constant. Now that the speed penalty is gone, it is practical to start writing membership tests using set-notation. This style is both semantically clear and operationally fast: extension = name.rpartition('.')[2] if extension in {'xml', 'html', 'xhtml', 'css'}: handle(name) (Patch and additional tests contributed by Dave Malcolm; bpo-6690(1)). * Serializing and unserializing data using the *note pickle: ca. module is now several times faster. (Contributed by Alexandre Vassalotti, Antoine Pitrou and the Unladen Swallow team in bpo-9410(2) and bpo-3873(3).) * The Timsort algorithm(4) used in *note list.sort(): 445. and *note sorted(): 444. now runs faster and uses less memory when called with a *note key function: 6e0. Previously, every element of a list was wrapped with a temporary object that remembered the key value associated with each element. Now, two arrays of keys and values are sorted in parallel. This saves the memory consumed by the sort wrappers, and it saves time lost to delegating comparisons. (Patch by Daniel Stutzbach in bpo-9915(5).) * JSON decoding performance is improved and memory consumption is reduced whenever the same string is repeated for multiple keys. Also, JSON encoding now uses the C speedups when the ‘sort_keys’ argument is true. (Contributed by Antoine Pitrou in bpo-7451(6) and by Raymond Hettinger and Antoine Pitrou in bpo-10314(7).) * Recursive locks (created with the *note threading.RLock(): bef. API) now benefit from a C implementation which makes them as fast as regular locks, and between 10x and 15x faster than their previous pure Python implementation. (Contributed by Antoine Pitrou; bpo-3001(8).) * The fast-search algorithm in stringlib is now used by the ‘split()’, ‘rsplit()’, ‘splitlines()’ and ‘replace()’ methods on *note bytes: 331, *note bytearray: 332. and *note str: 330. objects. Likewise, the algorithm is also used by ‘rfind()’, ‘rindex()’, ‘rsplit()’ and ‘rpartition()’. (Patch by Florent Xicluna in bpo-7622(9) and bpo-7462(10).) * Integer to string conversions now work two “digits” at a time, reducing the number of division and modulo operations. (bpo-6713(11) by Gawain Bolton, Mark Dickinson, and Victor Stinner.) There were several other minor optimizations. Set differencing now runs faster when one operand is much larger than the other (patch by Andress Bennetts in bpo-8685(12)). The ‘array.repeat()’ method has a faster implementation (bpo-1569291(13) by Alexander Belopolsky). The ‘BaseHTTPRequestHandler’ has more efficient buffering (bpo-3709(14) by Andrew Schaaf). The *note operator.attrgetter(): 71b. function has been sped-up (bpo-10160(15) by Christos Georgiou). And ‘ConfigParser’ loads multi-line arguments a bit faster (bpo-7113(16) by Łukasz Langa). ---------- Footnotes ---------- (1) https://bugs.python.org/issue6690 (2) https://bugs.python.org/issue9410 (3) https://bugs.python.org/issue3873 (4) https://en.wikipedia.org/wiki/Timsort (5) https://bugs.python.org/issue9915 (6) https://bugs.python.org/issue7451 (7) https://bugs.python.org/issue10314 (8) https://bugs.python.org/issue3001 (9) https://bugs.python.org/issue7622 (10) https://bugs.python.org/issue7462 (11) https://bugs.python.org/issue6713 (12) https://bugs.python.org/issue8685 (13) https://bugs.python.org/issue1569291 (14) https://bugs.python.org/issue3709 (15) https://bugs.python.org/issue10160 (16) https://bugs.python.org/issue7113  File: python.info, Node: Unicode, Next: Codecs, Prev: Optimizations<6>, Up: What’s New In Python 3 2 1.7.12 Unicode -------------- Python has been updated to Unicode 6.0.0(1). The update to the standard adds over 2,000 new characters including emoji(2) symbols which are important for mobile phones. In addition, the updated standard has altered the character properties for two Kannada characters (U+0CF1, U+0CF2) and one New Tai Lue numeric character (U+19DA), making the former eligible for use in identifiers while disqualifying the latter. For more information, see Unicode Character Database Changes(3). ---------- Footnotes ---------- (1) http://unicode.org/versions/Unicode6.0.0/ (2) https://en.wikipedia.org/wiki/Emoji (3) http://www.unicode.org/versions/Unicode6.0.0/#Database_Changes  File: python.info, Node: Codecs, Next: Documentation, Prev: Unicode, Up: What’s New In Python 3 2 1.7.13 Codecs ------------- Support was added for `cp720' Arabic DOS encoding (bpo-1616979(1)). MBCS encoding no longer ignores the error handler argument. In the default strict mode, it raises an *note UnicodeDecodeError: 1fd. when it encounters an undecodable byte sequence and an *note UnicodeEncodeError: 1fc. for an unencodable character. The MBCS codec supports ‘'strict'’ and ‘'ignore'’ error handlers for decoding, and ‘'strict'’ and ‘'replace'’ for encoding. To emulate Python3.1 MBCS encoding, select the ‘'ignore'’ handler for decoding and the ‘'replace'’ handler for encoding. On Mac OS X, Python decodes command line arguments with ‘'utf-8'’ rather than the locale encoding. By default, *note tarfile: 101. uses ‘'utf-8'’ encoding on Windows (instead of ‘'mbcs'’) and the ‘'surrogateescape'’ error handler on all operating systems. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1616979  File: python.info, Node: Documentation, Next: IDLE, Prev: Codecs, Up: What’s New In Python 3 2 1.7.14 Documentation -------------------- The documentation continues to be improved. * A table of quick links has been added to the top of lengthy sections such as *note Built-in Functions: bf3. In the case of *note itertools: a3, the links are accompanied by tables of cheatsheet-style summaries to provide an overview and memory jog without having to read all of the docs. * In some cases, the pure Python source code can be a helpful adjunct to the documentation, so now many modules now feature quick links to the latest version of the source code. For example, the *note functools: 85. module documentation has a quick link at the top labeled: `Source code' Lib/functools.py(1). (Contributed by Raymond Hettinger; see rationale(2).) * The docs now contain more examples and recipes. In particular, *note re: dd. module has an extensive section, *note Regular Expression Examples: bf4. Likewise, the *note itertools: a3. module continues to be updated with new *note Itertools Recipes: bf5. * The *note datetime: 31. module now has an auxiliary implementation in pure Python. No functionality was changed. This just provides an easier-to-read alternate implementation. (Contributed by Alexander Belopolsky in bpo-9528(3).) * The unmaintained ‘Demo’ directory has been removed. Some demos were integrated into the documentation, some were moved to the ‘Tools/demo’ directory, and others were removed altogether. (Contributed by Georg Brandl in bpo-7962(4).) ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/functools.py (2) https://rhettinger.wordpress.com/2011/01/28/open-your-source-more/ (3) https://bugs.python.org/issue9528 (4) https://bugs.python.org/issue7962  File: python.info, Node: IDLE, Next: Code Repository, Prev: Documentation, Up: What’s New In Python 3 2 1.7.15 IDLE ----------- * The format menu now has an option to clean source files by stripping trailing whitespace. (Contributed by Raymond Hettinger; bpo-5150(1).) * IDLE on Mac OS X now works with both Carbon AquaTk and Cocoa AquaTk. (Contributed by Kevin Walzer, Ned Deily, and Ronald Oussoren; bpo-6075(2).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5150 (2) https://bugs.python.org/issue6075  File: python.info, Node: Code Repository, Next: Build and C API Changes<5>, Prev: IDLE, Up: What’s New In Python 3 2 1.7.16 Code Repository ---------------------- In addition to the existing Subversion code repository at ‘http://svn.python.org’ there is now a Mercurial(1) repository at ‘https://hg.python.org/’. After the 3.2 release, there are plans to switch to Mercurial as the primary repository. This distributed version control system should make it easier for members of the community to create and share external changesets. See PEP 385(2) for details. To learn to use the new version control system, see the Quick Start(3) or the Guide to Mercurial Workflows(4). ---------- Footnotes ---------- (1) https://www.mercurial-scm.org/ (2) https://www.python.org/dev/peps/pep-0385 (3) https://www.mercurial-scm.org/wiki/QuickStart (4) https://www.mercurial-scm.org/guide  File: python.info, Node: Build and C API Changes<5>, Next: Porting to Python 3 2, Prev: Code Repository, Up: What’s New In Python 3 2 1.7.17 Build and C API Changes ------------------------------ Changes to Python’s build process and to the C API include: * The `idle', `pydoc' and `2to3' scripts are now installed with a version-specific suffix on ‘make altinstall’ (bpo-10679(1)). * The C functions that access the Unicode Database now accept and return characters from the full Unicode range, even on narrow unicode builds (Py_UNICODE_TOLOWER, Py_UNICODE_ISDECIMAL, and others). A visible difference in Python is that *note unicodedata.numeric(): bf9. now returns the correct value for large code points, and *note repr(): 7cc. may consider more characters as printable. (Reported by Bupjoe Lee and fixed by Amaury Forgeot D’Arc; bpo-5127(2).) * Computed gotos are now enabled by default on supported compilers (which are detected by the configure script). They can still be disabled selectively by specifying ‘--without-computed-gotos’. (Contributed by Antoine Pitrou; bpo-9203(3).) * The option ‘--with-wctype-functions’ was removed. The built-in unicode database is now used for all functions. (Contributed by Amaury Forgeot D’Arc; bpo-9210(4).) * Hash values are now values of a new type, ‘Py_hash_t’, which is defined to be the same size as a pointer. Previously they were of type long, which on some 64-bit operating systems is still only 32 bits long. As a result of this fix, *note set: b6f. and *note dict: 1b8. can now hold more than ‘2**32’ entries on builds with 64-bit pointers (previously, they could grow to that size but their performance degraded catastrophically). (Suggested by Raymond Hettinger and implemented by Benjamin Peterson; bpo-9778(5).) * A new macro ‘Py_VA_COPY’ copies the state of the variable argument list. It is equivalent to C99 `va_copy' but available on all Python platforms (bpo-2443(6)). * A new C API function *note PySys_SetArgvEx(): bfa. allows an embedded interpreter to set *note sys.argv: bfb. without also modifying *note sys.path: 488. (bpo-5753(7)). * ‘PyEval_CallObject’ is now only available in macro form. The function declaration, which was kept for backwards compatibility reasons, is now removed – the macro was introduced in 1997 (bpo-8276(8)). * There is a new function *note PyLong_AsLongLongAndOverflow(): bfc. which is analogous to *note PyLong_AsLongAndOverflow(): bfd. They both serve to convert Python *note int: 184. into a native fixed-width type while providing detection of cases where the conversion won’t fit (bpo-7767(9)). * The *note PyUnicode_CompareWithASCIIString(): bfe. function now returns `not equal' if the Python string is `NUL' terminated. * There is a new function *note PyErr_NewExceptionWithDoc(): bff. that is like *note PyErr_NewException(): c00. but allows a docstring to be specified. This lets C exceptions have the same self-documenting capabilities as their pure Python counterparts (bpo-7033(10)). * When compiled with the ‘--with-valgrind’ option, the pymalloc allocator will be automatically disabled when running under Valgrind. This gives improved memory leak detection when running under Valgrind, while taking advantage of pymalloc at other times (bpo-2422(11)). * Removed the ‘O?’ format from the `PyArg_Parse' functions. The format is no longer used and it had never been documented (bpo-8837(12)). There were a number of other small changes to the C-API. See the Misc/NEWS(13) file for a complete list. Also, there were a number of updates to the Mac OS X build, see Mac/BuildScript/README.txt(14) for details. For users running a 32/64-bit build, there is a known problem with the default Tcl/Tk on Mac OS X 10.6. Accordingly, we recommend installing an updated alternative such as ActiveState Tcl/Tk 8.5.9(15). See ‘https://www.python.org/download/mac/tcltk/’ for additional details. ---------- Footnotes ---------- (1) https://bugs.python.org/issue10679 (2) https://bugs.python.org/issue5127 (3) https://bugs.python.org/issue9203 (4) https://bugs.python.org/issue9210 (5) https://bugs.python.org/issue9778 (6) https://bugs.python.org/issue2443 (7) https://bugs.python.org/issue5753 (8) https://bugs.python.org/issue8276 (9) https://bugs.python.org/issue7767 (10) https://bugs.python.org/issue7033 (11) https://bugs.python.org/issue2422 (12) https://bugs.python.org/issue8837 (13) https://github.com/python/cpython/tree/3.8/Misc/NEWS (14) https://github.com/python/cpython/tree/3.8/Mac/BuildScript/README.txt (15) https://www.activestate.com/activetcl/downloads  File: python.info, Node: Porting to Python 3 2, Prev: Build and C API Changes<5>, Up: What’s New In Python 3 2 1.7.18 Porting to Python 3.2 ---------------------------- This section lists previously described changes and other bugfixes that may require changes to your code: * The *note configparser: 23. module has a number of clean-ups. The major change is to replace the old ‘ConfigParser’ class with long-standing preferred alternative ‘SafeConfigParser’. In addition there are a number of smaller incompatibilities: * The interpolation syntax is now validated on *note get(): c02. and *note set(): c03. operations. In the default interpolation scheme, only two tokens with percent signs are valid: ‘%(name)s’ and ‘%%’, the latter being an escaped percent sign. * The *note set(): c03. and *note add_section(): c04. methods now verify that values are actual strings. Formerly, unsupported types could be introduced unintentionally. * Duplicate sections or options from a single source now raise either *note DuplicateSectionError: c05. or *note DuplicateOptionError: c06. Formerly, duplicates would silently overwrite a previous entry. * Inline comments are now disabled by default so now the `;' character can be safely used in values. * Comments now can be indented. Consequently, for `;' or `#' to appear at the start of a line in multiline values, it has to be interpolated. This keeps comment prefix characters in values from being mistaken as comments. * ‘""’ is now a valid value and is no longer automatically converted to an empty string. For empty strings, use ‘"option ="’ in a line. * The *note nntplib: c0. module was reworked extensively, meaning that its APIs are often incompatible with the 3.1 APIs. * *note bytearray: 332. objects can no longer be used as filenames; instead, they should be converted to *note bytes: 331. * The ‘array.tostring()’ and ‘array.fromstring()’ have been renamed to ‘array.tobytes()’ and ‘array.frombytes()’ for clarity. The old names have been deprecated. (See bpo-8990(1).) * ‘PyArg_Parse*()’ functions: * “t#” format has been removed: use “s#” or “s*” instead * “w” and “w#” formats has been removed: use “w*” instead * The ‘PyCObject’ type, deprecated in 3.1, has been removed. To wrap opaque C pointers in Python objects, the *note PyCapsule: c07. API should be used instead; the new type has a well-defined interface for passing typing safety information and a less complicated signature for calling a destructor. * The ‘sys.setfilesystemencoding()’ function was removed because it had a flawed design. * The *note random.seed(): c08. function and method now salt string seeds with an sha512 hash function. To access the previous version of `seed' in order to reproduce Python 3.1 sequences, set the `version' argument to `1', ‘random.seed(s, version=1)’. * The previously deprecated ‘string.maketrans()’ function has been removed in favor of the static methods *note bytes.maketrans(): c09. and *note bytearray.maketrans(): c0a. This change solves the confusion around which types were supported by the *note string: f6. module. Now, *note str: 330, *note bytes: 331, and *note bytearray: 332. each have their own `maketrans' and `translate' methods with intermediate translation tables of the appropriate type. (Contributed by Georg Brandl; bpo-5675(2).) * The previously deprecated ‘contextlib.nested()’ function has been removed in favor of a plain *note with: 6e9. statement which can accept multiple context managers. The latter technique is faster (because it is built-in), and it does a better job finalizing multiple context managers when one of them raises an exception: with open('mylog.txt') as infile, open('a.out', 'w') as outfile: for line in infile: if '' in line: outfile.write(line) (Contributed by Georg Brandl and Mattias Brändström; appspot issue 53094(3).) * *note struct.pack(): c0b. now only allows bytes for the ‘s’ string pack code. Formerly, it would accept text arguments and implicitly encode them to bytes using UTF-8. This was problematic because it made assumptions about the correct encoding and because a variable-length encoding can fail when writing to fixed length segment of a structure. Code such as ‘struct.pack('<6sHHBBB', 'GIF87a', x, y)’ should be rewritten with to use bytes instead of text, ‘struct.pack('<6sHHBBB', b'GIF87a', x, y)’. (Discovered by David Beazley and fixed by Victor Stinner; bpo-10783(4).) * The *note xml.etree.ElementTree: 137. class now raises an *note xml.etree.ElementTree.ParseError: c0c. when a parse fails. Previously it raised an *note xml.parsers.expat.ExpatError: c0d. * The new, longer *note str(): 330. value on floats may break doctests which rely on the old output format. * In *note subprocess.Popen: 2b9, the default value for `close_fds' is now ‘True’ under Unix; under Windows, it is ‘True’ if the three standard streams are set to ‘None’, ‘False’ otherwise. Previously, `close_fds' was always ‘False’ by default, which produced difficult to solve bugs or race conditions when open file descriptors would leak into the child process. * Support for legacy HTTP 0.9 has been removed from *note urllib.request: 120. and *note http.client: 94. Such support is still present on the server side (in *note http.server: 97.). (Contributed by Antoine Pitrou, bpo-10711(5).) * SSL sockets in timeout mode now raise *note socket.timeout: c0e. when a timeout occurs, rather than a generic *note SSLError: c0f. (Contributed by Antoine Pitrou, bpo-10272(6).) * The misleading functions *note PyEval_AcquireLock(): 2b2. and *note PyEval_ReleaseLock(): c10. have been officially deprecated. The thread-state aware APIs (such as *note PyEval_SaveThread(): c11. and *note PyEval_RestoreThread(): 2b4.) should be used instead. * Due to security risks, ‘asyncore.handle_accept()’ has been deprecated, and a new function, ‘asyncore.handle_accepted()’, was added to replace it. (Contributed by Giampaolo Rodola in bpo-6706(7).) * Due to the new *note GIL: bea. implementation, *note PyEval_InitThreads(): c12. cannot be called before *note Py_Initialize(): 439. anymore. ---------- Footnotes ---------- (1) https://bugs.python.org/issue8990 (2) https://bugs.python.org/issue5675 (3) https://codereview.appspot.com/53094 (4) https://bugs.python.org/issue10783 (5) https://bugs.python.org/issue10711 (6) https://bugs.python.org/issue10272 (7) https://bugs.python.org/issue6706  File: python.info, Node: What’s New In Python 3 1, Next: What’s New In Python 3 0, Prev: What’s New In Python 3 2, Up: What’s New in Python 1.8 What’s New In Python 3.1 ============================ Author: Raymond Hettinger This article explains the new features in Python 3.1, compared to 3.0. * Menu: * PEP 372; Ordered Dictionaries: PEP 372 Ordered Dictionaries. * PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator. * Other Language Changes: Other Language Changes<8>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<2>. * Optimizations: Optimizations<7>. * IDLE: IDLE<2>. * Build and C API Changes: Build and C API Changes<6>. * Porting to Python 3.1: Porting to Python 3 1.  File: python.info, Node: PEP 372 Ordered Dictionaries, Next: PEP 378 Format Specifier for Thousands Separator, Up: What’s New In Python 3 1 1.8.1 PEP 372: Ordered Dictionaries ----------------------------------- Regular Python dictionaries iterate over key/value pairs in arbitrary order. Over the years, a number of authors have written alternative implementations that remember the order that the keys were originally inserted. Based on the experiences from those implementations, a new *note collections.OrderedDict: 1b9. class has been introduced. The OrderedDict API is substantially the same as regular dictionaries but will iterate over keys and values in a guaranteed order depending on when a key was first inserted. If a new entry overwrites an existing entry, the original insertion position is left unchanged. Deleting an entry and reinserting it will move it to the end. The standard library now supports use of ordered dictionaries in several modules. The *note configparser: 23. module uses them by default. This lets configuration files be read, modified, and then written back in their original order. The `_asdict()' method for *note collections.namedtuple(): 1b7. now returns an ordered dictionary with the values appearing in the same order as the underlying tuple indices. The *note json: a4. module is being built-out with an `object_pairs_hook' to allow OrderedDicts to be built by the decoder. Support was also added for third-party tools like PyYAML(1). See also ........ PEP 372(2) - Ordered Dictionaries PEP written by Armin Ronacher and Raymond Hettinger. Implementation written by Raymond Hettinger. ---------- Footnotes ---------- (1) http://pyyaml.org/ (2) https://www.python.org/dev/peps/pep-0372  File: python.info, Node: PEP 378 Format Specifier for Thousands Separator, Next: Other Language Changes<8>, Prev: PEP 372 Ordered Dictionaries, Up: What’s New In Python 3 1 1.8.2 PEP 378: Format Specifier for Thousands Separator ------------------------------------------------------- The built-in *note format(): 4db. function and the *note str.format(): 4da. method use a mini-language that now includes a simple, non-locale aware way to format a number with a thousands separator. That provides a way to humanize a program’s output, improving its professional appearance and readability: >>> format(1234567, ',d') '1,234,567' >>> format(1234567.89, ',.2f') '1,234,567.89' >>> format(12345.6 + 8901234.12j, ',f') '12,345.600000+8,901,234.120000j' >>> format(Decimal('1234567.89'), ',f') '1,234,567.89' The supported types are *note int: 184, *note float: 187, *note complex: 189. and *note decimal.Decimal: 188. Discussions are underway about how to specify alternative separators like dots, spaces, apostrophes, or underscores. Locale-aware applications should use the existing `n' format specifier which already has some support for thousands separators. See also ........ PEP 378(1) - Format Specifier for Thousands Separator PEP written by Raymond Hettinger and implemented by Eric Smith and Mark Dickinson. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0378  File: python.info, Node: Other Language Changes<8>, Next: New Improved and Deprecated Modules<2>, Prev: PEP 378 Format Specifier for Thousands Separator, Up: What’s New In Python 3 1 1.8.3 Other Language Changes ---------------------------- Some smaller changes made to the core Python language are: * Directories and zip archives containing a ‘__main__.py’ file can now be executed directly by passing their name to the interpreter. The directory/zipfile is automatically inserted as the first entry in sys.path. (Suggestion and initial patch by Andy Chu; revised patch by Phillip J. Eby and Nick Coghlan; bpo-1739468(1).) * The *note int(): 184. type gained a ‘bit_length’ method that returns the number of bits necessary to represent its argument in binary: >>> n = 37 >>> bin(37) '0b100101' >>> n.bit_length() 6 >>> n = 2**123-1 >>> n.bit_length() 123 >>> (n+1).bit_length() 124 (Contributed by Fredrik Johansson, Victor Stinner, Raymond Hettinger, and Mark Dickinson; bpo-3439(2).) * The fields in *note format(): 4db. strings can now be automatically numbered: >>> 'Sir {} of {}'.format('Gallahad', 'Camelot') 'Sir Gallahad of Camelot' Formerly, the string would have required numbered fields such as: ‘'Sir {0} of {1}'’. (Contributed by Eric Smith; bpo-5237(3).) * The ‘string.maketrans()’ function is deprecated and is replaced by new static methods, *note bytes.maketrans(): c09. and *note bytearray.maketrans(): c0a. This change solves the confusion around which types were supported by the *note string: f6. module. Now, *note str: 330, *note bytes: 331, and *note bytearray: 332. each have their own `maketrans' and `translate' methods with intermediate translation tables of the appropriate type. (Contributed by Georg Brandl; bpo-5675(4).) * The syntax of the *note with: 6e9. statement now allows multiple context managers in a single statement: >>> with open('mylog.txt') as infile, open('a.out', 'w') as outfile: ... for line in infile: ... if '' in line: ... outfile.write(line) With the new syntax, the ‘contextlib.nested()’ function is no longer needed and is now deprecated. (Contributed by Georg Brandl and Mattias Brändström; appspot issue 53094(5).) * ‘round(x, n)’ now returns an integer if `x' is an integer. Previously it returned a float: >>> round(1123, -2) 1100 (Contributed by Mark Dickinson; bpo-4707(6).) * Python now uses David Gay’s algorithm for finding the shortest floating point representation that doesn’t change its value. This should help mitigate some of the confusion surrounding binary floating point numbers. The significance is easily seen with a number like ‘1.1’ which does not have an exact equivalent in binary floating point. Since there is no exact equivalent, an expression like ‘float('1.1')’ evaluates to the nearest representable value which is ‘0x1.199999999999ap+0’ in hex or ‘1.100000000000000088817841970012523233890533447265625’ in decimal. That nearest value was and still is used in subsequent floating point calculations. What is new is how the number gets displayed. Formerly, Python used a simple approach. The value of ‘repr(1.1)’ was computed as ‘format(1.1, '.17g')’ which evaluated to ‘'1.1000000000000001'’. The advantage of using 17 digits was that it relied on IEEE-754 guarantees to assure that ‘eval(repr(1.1))’ would round-trip exactly to its original value. The disadvantage is that many people found the output to be confusing (mistaking intrinsic limitations of binary floating point representation as being a problem with Python itself). The new algorithm for ‘repr(1.1)’ is smarter and returns ‘'1.1'’. Effectively, it searches all equivalent string representations (ones that get stored with the same underlying float value) and returns the shortest representation. The new algorithm tends to emit cleaner representations when possible, but it does not change the underlying values. So, it is still the case that ‘1.1 + 2.2 != 3.3’ even though the representations may suggest otherwise. The new algorithm depends on certain features in the underlying floating point implementation. If the required features are not found, the old algorithm will continue to be used. Also, the text pickle protocols assure cross-platform portability by using the old algorithm. (Contributed by Eric Smith and Mark Dickinson; bpo-1580(7)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1739468 (2) https://bugs.python.org/issue3439 (3) https://bugs.python.org/issue5237 (4) https://bugs.python.org/issue5675 (5) https://codereview.appspot.com/53094 (6) https://bugs.python.org/issue4707 (7) https://bugs.python.org/issue1580  File: python.info, Node: New Improved and Deprecated Modules<2>, Next: Optimizations<7>, Prev: Other Language Changes<8>, Up: What’s New In Python 3 1 1.8.4 New, Improved, and Deprecated Modules ------------------------------------------- * Added a *note collections.Counter: 9da. class to support convenient counting of unique items in a sequence or iterable: >>> Counter(['red', 'blue', 'red', 'green', 'blue', 'blue']) Counter({'blue': 3, 'red': 2, 'green': 1}) (Contributed by Raymond Hettinger; bpo-1696199(1).) * Added a new module, *note tkinter.ttk: 10f. for access to the Tk themed widget set. The basic idea of ttk is to separate, to the extent possible, the code implementing a widget’s behavior from the code implementing its appearance. (Contributed by Guilherme Polo; bpo-2983(2).) * The *note gzip.GzipFile: 6dd. and *note bz2.BZ2File: 931. classes now support the context management protocol: >>> # Automatically close file after writing >>> with gzip.GzipFile(filename, "wb") as f: ... f.write(b"xxx") (Contributed by Antoine Pitrou.) * The *note decimal: 36. module now supports methods for creating a decimal object from a binary *note float: 187. The conversion is exact but can sometimes be surprising: >>> Decimal.from_float(1.1) Decimal('1.100000000000000088817841970012523233890533447265625') The long decimal result shows the actual binary fraction being stored for `1.1'. The fraction has many digits because `1.1' cannot be exactly represented in binary. (Contributed by Raymond Hettinger and Mark Dickinson.) * The *note itertools: a3. module grew two new functions. The *note itertools.combinations_with_replacement(): c19. function is one of four for generating combinatorics including permutations and Cartesian products. The *note itertools.compress(): c1a. function mimics its namesake from APL. Also, the existing *note itertools.count(): c1b. function now has an optional `step' argument and can accept any type of counting sequence including *note fractions.Fraction: 185. and *note decimal.Decimal: 188.: >>> [p+q for p,q in combinations_with_replacement('LOVE', 2)] ['LL', 'LO', 'LV', 'LE', 'OO', 'OV', 'OE', 'VV', 'VE', 'EE'] >>> list(compress(data=range(10), selectors=[0,0,1,1,0,1,0,1,0,0])) [2, 3, 5, 7] >>> c = count(start=Fraction(1,2), step=Fraction(1,6)) >>> [next(c), next(c), next(c), next(c)] [Fraction(1, 2), Fraction(2, 3), Fraction(5, 6), Fraction(1, 1)] (Contributed by Raymond Hettinger.) * *note collections.namedtuple(): 1b7. now supports a keyword argument `rename' which lets invalid fieldnames be automatically converted to positional names in the form _0, _1, etc. This is useful when the field names are being created by an external source such as a CSV header, SQL field list, or user input: >>> query = input() SELECT region, dept, count(*) FROM main GROUPBY region, dept >>> cursor.execute(query) >>> query_fields = [desc[0] for desc in cursor.description] >>> UserQuery = namedtuple('UserQuery', query_fields, rename=True) >>> pprint.pprint([UserQuery(*row) for row in cursor]) [UserQuery(region='South', dept='Shipping', _2=185), UserQuery(region='North', dept='Accounting', _2=37), UserQuery(region='West', dept='Sales', _2=419)] (Contributed by Raymond Hettinger; bpo-1818(3).) * The *note re.sub(): 47b, *note re.subn(): 734. and *note re.split(): 3ca. functions now accept a flags parameter. (Contributed by Gregory Smith.) * The *note logging: aa. module now implements a simple *note logging.NullHandler: c1c. class for applications that are not using logging but are calling library code that does. Setting-up a null handler will suppress spurious warnings such as “No handlers could be found for logger foo”: >>> h = logging.NullHandler() >>> logging.getLogger("foo").addHandler(h) (Contributed by Vinay Sajip; bpo-4384(4)). * The *note runpy: e2. module which supports the ‘-m’ command line switch now supports the execution of packages by looking for and executing a ‘__main__’ submodule when a package name is supplied. (Contributed by Andi Vajda; bpo-4195(5).) * The *note pdb: c9. module can now access and display source code loaded via *note zipimport: 143. (or any other conformant PEP 302(6) loader). (Contributed by Alexander Belopolsky; bpo-4201(7).) * *note functools.partial: 7c8. objects can now be pickled. (Suggested by Antoine Pitrou and Jesse Noller. Implemented by Jack Diederich; bpo-5228(8).) * Add *note pydoc: d9. help topics for symbols so that ‘help('@')’ works as expected in the interactive environment. (Contributed by David Laban; bpo-4739(9).) * The *note unittest: 11b. module now supports skipping individual tests or classes of tests. And it supports marking a test as an expected failure, a test that is known to be broken, but shouldn’t be counted as a failure on a TestResult: class TestGizmo(unittest.TestCase): @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows") def test_gizmo_on_windows(self): ... @unittest.expectedFailure def test_gimzo_without_required_library(self): ... Also, tests for exceptions have been builtout to work with context managers using the *note with: 6e9. statement: def test_division_by_zero(self): with self.assertRaises(ZeroDivisionError): x / 0 In addition, several new assertion methods were added including ‘assertSetEqual()’, ‘assertDictEqual()’, ‘assertDictContainsSubset()’, ‘assertListEqual()’, ‘assertTupleEqual()’, ‘assertSequenceEqual()’, ‘assertRaisesRegexp()’, ‘assertIsNone()’, and ‘assertIsNotNone()’. (Contributed by Benjamin Peterson and Antoine Pitrou.) * The *note io: a1. module has three new constants for the ‘seek()’ method ‘SEEK_SET’, ‘SEEK_CUR’, and ‘SEEK_END’. * The *note sys.version_info: b1a. tuple is now a named tuple: >>> sys.version_info sys.version_info(major=3, minor=1, micro=0, releaselevel='alpha', serial=2) (Contributed by Ross Light; bpo-4285(10).) * The *note nntplib: c0. and *note imaplib: 98. modules now support IPv6. (Contributed by Derek Morr; bpo-1655(11) and bpo-1664(12).) * The *note pickle: ca. module has been adapted for better interoperability with Python 2.x when used with protocol 2 or lower. The reorganization of the standard library changed the formal reference for many objects. For example, ‘__builtin__.set’ in Python 2 is called ‘builtins.set’ in Python 3. This change confounded efforts to share data between different versions of Python. But now when protocol 2 or lower is selected, the pickler will automatically use the old Python 2 names for both loading and dumping. This remapping is turned-on by default but can be disabled with the `fix_imports' option: >>> s = {1, 2, 3} >>> pickle.dumps(s, protocol=0) b'c__builtin__\nset\np0\n((lp1\nL1L\naL2L\naL3L\natp2\nRp3\n.' >>> pickle.dumps(s, protocol=0, fix_imports=False) b'cbuiltins\nset\np0\n((lp1\nL1L\naL2L\naL3L\natp2\nRp3\n.' An unfortunate but unavoidable side-effect of this change is that protocol 2 pickles produced by Python 3.1 won’t be readable with Python 3.0. The latest pickle protocol, protocol 3, should be used when migrating data between Python 3.x implementations, as it doesn’t attempt to remain compatible with Python 2.x. (Contributed by Alexandre Vassalotti and Antoine Pitrou, bpo-6137(13).) * A new module, *note importlib: 9b. was added. It provides a complete, portable, pure Python reference implementation of the *note import: c1d. statement and its counterpart, the *note __import__(): 610. function. It represents a substantial step forward in documenting and defining the actions that take place during imports. (Contributed by Brett Cannon.) ---------- Footnotes ---------- (1) https://bugs.python.org/issue1696199 (2) https://bugs.python.org/issue2983 (3) https://bugs.python.org/issue1818 (4) https://bugs.python.org/issue4384 (5) https://bugs.python.org/issue4195 (6) https://www.python.org/dev/peps/pep-0302 (7) https://bugs.python.org/issue4201 (8) https://bugs.python.org/issue5228 (9) https://bugs.python.org/issue4739 (10) https://bugs.python.org/issue4285 (11) https://bugs.python.org/issue1655 (12) https://bugs.python.org/issue1664 (13) https://bugs.python.org/issue6137  File: python.info, Node: Optimizations<7>, Next: IDLE<2>, Prev: New Improved and Deprecated Modules<2>, Up: What’s New In Python 3 1 1.8.5 Optimizations ------------------- Major performance enhancements have been added: * The new I/O library (as defined in PEP 3116(1)) was mostly written in Python and quickly proved to be a problematic bottleneck in Python 3.0. In Python 3.1, the I/O library has been entirely rewritten in C and is 2 to 20 times faster depending on the task at hand. The pure Python version is still available for experimentation purposes through the ‘_pyio’ module. (Contributed by Amaury Forgeot d’Arc and Antoine Pitrou.) * Added a heuristic so that tuples and dicts containing only untrackable objects are not tracked by the garbage collector. This can reduce the size of collections and therefore the garbage collection overhead on long-running programs, depending on their particular use of datatypes. (Contributed by Antoine Pitrou, bpo-4688(2).) * Enabling a configure option named ‘--with-computed-gotos’ on compilers that support it (notably: gcc, SunPro, icc), the bytecode evaluation loop is compiled with a new dispatch mechanism which gives speedups of up to 20%, depending on the system, the compiler, and the benchmark. (Contributed by Antoine Pitrou along with a number of other participants, bpo-4753(3)). * The decoding of UTF-8, UTF-16 and LATIN-1 is now two to four times faster. (Contributed by Antoine Pitrou and Amaury Forgeot d’Arc, bpo-4868(4).) * The *note json: a4. module now has a C extension to substantially improve its performance. In addition, the API was modified so that json works only with *note str: 330, not with *note bytes: 331. That change makes the module closely match the JSON specification(5) which is defined in terms of Unicode. (Contributed by Bob Ippolito and converted to Py3.1 by Antoine Pitrou and Benjamin Peterson; bpo-4136(6).) * Unpickling now interns the attribute names of pickled objects. This saves memory and allows pickles to be smaller. (Contributed by Jake McGuire and Antoine Pitrou; bpo-5084(7).) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3116 (2) https://bugs.python.org/issue4688 (3) https://bugs.python.org/issue4753 (4) https://bugs.python.org/issue4868 (5) http://json.org/ (6) https://bugs.python.org/issue4136 (7) https://bugs.python.org/issue5084  File: python.info, Node: IDLE<2>, Next: Build and C API Changes<6>, Prev: Optimizations<7>, Up: What’s New In Python 3 1 1.8.6 IDLE ---------- * IDLE’s format menu now provides an option to strip trailing whitespace from a source file. (Contributed by Roger D. Serwy; bpo-5150(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5150  File: python.info, Node: Build and C API Changes<6>, Next: Porting to Python 3 1, Prev: IDLE<2>, Up: What’s New In Python 3 1 1.8.7 Build and C API Changes ----------------------------- Changes to Python’s build process and to the C API include: * Integers are now stored internally either in base 2**15 or in base 2**30, the base being determined at build time. Previously, they were always stored in base 2**15. Using base 2**30 gives significant performance improvements on 64-bit machines, but benchmark results on 32-bit machines have been mixed. Therefore, the default is to use base 2**30 on 64-bit machines and base 2**15 on 32-bit machines; on Unix, there’s a new configure option ‘--enable-big-digits’ that can be used to override this default. Apart from the performance improvements this change should be invisible to end users, with one exception: for testing and debugging purposes there’s a new *note sys.int_info: c21. that provides information about the internal format, giving the number of bits per digit and the size in bytes of the C type used to store each digit: >>> import sys >>> sys.int_info sys.int_info(bits_per_digit=30, sizeof_digit=4) (Contributed by Mark Dickinson; bpo-4258(1).) * The *note PyLong_AsUnsignedLongLong(): c22. function now handles a negative `pylong' by raising *note OverflowError: 960. instead of *note TypeError: 192. (Contributed by Mark Dickinson and Lisandro Dalcrin; bpo-5175(2).) * Deprecated ‘PyNumber_Int()’. Use *note PyNumber_Long(): 26c. instead. (Contributed by Mark Dickinson; bpo-4910(3).) * Added a new *note PyOS_string_to_double(): c23. function to replace the deprecated functions ‘PyOS_ascii_strtod()’ and ‘PyOS_ascii_atof()’. (Contributed by Mark Dickinson; bpo-5914(4).) * Added *note PyCapsule: c07. as a replacement for the ‘PyCObject’ API. The principal difference is that the new type has a well defined interface for passing typing safety information and a less complicated signature for calling a destructor. The old type had a problematic API and is now deprecated. (Contributed by Larry Hastings; bpo-5630(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4258 (2) https://bugs.python.org/issue5175 (3) https://bugs.python.org/issue4910 (4) https://bugs.python.org/issue5914 (5) https://bugs.python.org/issue5630  File: python.info, Node: Porting to Python 3 1, Prev: Build and C API Changes<6>, Up: What’s New In Python 3 1 1.8.8 Porting to Python 3.1 --------------------------- This section lists previously described changes and other bugfixes that may require changes to your code: * The new floating point string representations can break existing doctests. For example: def e(): '''Compute the base of natural logarithms. >>> e() 2.7182818284590451 ''' return sum(1/math.factorial(x) for x in reversed(range(30))) doctest.testmod() ********************************************************************** Failed example: e() Expected: 2.7182818284590451 Got: 2.718281828459045 ********************************************************************** * The automatic name remapping in the pickle module for protocol 2 or lower can make Python 3.1 pickles unreadable in Python 3.0. One solution is to use protocol 3. Another solution is to set the `fix_imports' option to ‘False’. See the discussion above for more details.  File: python.info, Node: What’s New In Python 3 0, Next: What’s New in Python 2 7, Prev: What’s New In Python 3 1, Up: What’s New in Python 1.9 What’s New In Python 3.0 ============================ Author: Guido van Rossum This article explains the new features in Python 3.0, compared to 2.6. Python 3.0, also known as “Python 3000” or “Py3K”, is the first ever `intentionally backwards incompatible' Python release. There are more changes than in a typical release, and more that are important for all Python users. Nevertheless, after digesting the changes, you’ll find that Python really hasn’t changed all that much – by and large, we’re mostly fixing well-known annoyances and warts, and removing a lot of old cruft. This article doesn’t attempt to provide a complete specification of all new features, but instead tries to give a convenient overview. For full details, you should refer to the documentation for Python 3.0, and/or the many PEPs referenced in the text. If you want to understand the complete implementation and design rationale for a particular feature, PEPs usually have more details than the regular documentation; but note that PEPs usually are not kept up-to-date once a feature has been fully implemented. Due to time constraints this document is not as complete as it should have been. As always for a new release, the ‘Misc/NEWS’ file in the source distribution contains a wealth of detailed information about every small thing that was changed. * Menu: * Common Stumbling Blocks:: * Overview Of Syntax Changes:: * Changes Already Present In Python 2.6: Changes Already Present In Python 2 6. * Library Changes:: * PEP 3101; A New Approach To String Formatting: PEP 3101 A New Approach To String Formatting. * Changes To Exceptions:: * Miscellaneous Other Changes:: * Build and C API Changes: Build and C API Changes<7>. * Performance:: * Porting To Python 3.0: Porting To Python 3 0.  File: python.info, Node: Common Stumbling Blocks, Next: Overview Of Syntax Changes, Up: What’s New In Python 3 0 1.9.1 Common Stumbling Blocks ----------------------------- This section lists those few changes that are most likely to trip you up if you’re used to Python 2.5. * Menu: * Print Is A Function:: * Views And Iterators Instead Of Lists:: * Ordering Comparisons:: * Integers:: * Text Vs. Data Instead Of Unicode Vs. 8-bit: Text Vs Data Instead Of Unicode Vs 8-bit.  File: python.info, Node: Print Is A Function, Next: Views And Iterators Instead Of Lists, Up: Common Stumbling Blocks 1.9.1.1 Print Is A Function ........................... The ‘print’ statement has been replaced with a *note print(): 886. function, with keyword arguments to replace most of the special syntax of the old ‘print’ statement ( PEP 3105(1)). Examples: Old: print "The answer is", 2*2 New: print("The answer is", 2*2) Old: print x, # Trailing comma suppresses newline New: print(x, end=" ") # Appends a space instead of a newline Old: print # Prints a newline New: print() # You must call the function! Old: print >>sys.stderr, "fatal error" New: print("fatal error", file=sys.stderr) Old: print (x, y) # prints repr((x, y)) New: print((x, y)) # Not the same as print(x, y)! You can also customize the separator between items, e.g.: print("There are <", 2**32, "> possibilities!", sep="") which produces: There are <4294967296> possibilities! Note: * The *note print(): 886. function doesn’t support the “softspace” feature of the old ‘print’ statement. For example, in Python 2.x, ‘print "A\n", "B"’ would write ‘"A\nB\n"’; but in Python 3.0, ‘print("A\n", "B")’ writes ‘"A\n B\n"’. * Initially, you’ll be finding yourself typing the old ‘print x’ a lot in interactive mode. Time to retrain your fingers to type ‘print(x)’ instead! * When using the ‘2to3’ source-to-source conversion tool, all ‘print’ statements are automatically converted to *note print(): 886. function calls, so this is mostly a non-issue for larger projects. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3105  File: python.info, Node: Views And Iterators Instead Of Lists, Next: Ordering Comparisons, Prev: Print Is A Function, Up: Common Stumbling Blocks 1.9.1.2 Views And Iterators Instead Of Lists ............................................ Some well-known APIs no longer return lists: * *note dict: 1b8. methods *note dict.keys(): c2a, *note dict.items(): c2b. and *note dict.values(): c2c. return “views” instead of lists. For example, this no longer works: ‘k = d.keys(); k.sort()’. Use ‘k = sorted(d)’ instead (this works in Python 2.5 too and is just as efficient). * Also, the ‘dict.iterkeys()’, ‘dict.iteritems()’ and ‘dict.itervalues()’ methods are no longer supported. * *note map(): c2d. and *note filter(): c2e. return iterators. If you really need a list and the input sequences are all of equal length, a quick fix is to wrap *note map(): c2d. in *note list(): 262, e.g. ‘list(map(...))’, but a better fix is often to use a list comprehension (especially when the original code uses *note lambda: c2f.), or rewriting the code so it doesn’t need a list at all. Particularly tricky is *note map(): c2d. invoked for the side effects of the function; the correct transformation is to use a regular *note for: c30. loop (since creating a list would just be wasteful). If the input sequences are not of equal length, *note map(): c2d. will stop at the termination of the shortest of the sequences. For full compatibility with *note map(): c2d. from Python 2.x, also wrap the sequences in *note itertools.zip_longest(): c31, e.g. ‘map(func, *sequences)’ becomes ‘list(map(func, itertools.zip_longest(*sequences)))’. * *note range(): 9be. now behaves like ‘xrange()’ used to behave, except it works with values of arbitrary size. The latter no longer exists. * *note zip(): c32. now returns an iterator.  File: python.info, Node: Ordering Comparisons, Next: Integers, Prev: Views And Iterators Instead Of Lists, Up: Common Stumbling Blocks 1.9.1.3 Ordering Comparisons ............................ Python 3.0 has simplified the rules for ordering comparisons: * The ordering comparison operators (‘<’, ‘<=’, ‘>=’, ‘>’) raise a TypeError exception when the operands don’t have a meaningful natural ordering. Thus, expressions like ‘1 < ''’, ‘0 > None’ or ‘len <= len’ are no longer valid, and e.g. ‘None < None’ raises *note TypeError: 192. instead of returning ‘False’. A corollary is that sorting a heterogeneous list no longer makes sense – all the elements must be comparable to each other. Note that this does not apply to the ‘==’ and ‘!=’ operators: objects of different incomparable types always compare unequal to each other. * ‘builtin.sorted()’ and *note list.sort(): 445. no longer accept the `cmp' argument providing a comparison function. Use the `key' argument instead. N.B. the `key' and `reverse' arguments are now “keyword-only”. * The ‘cmp()’ function should be treated as gone, and the ‘__cmp__()’ special method is no longer supported. Use *note __lt__(): c34. for sorting, *note __eq__(): 33f. with *note __hash__(): 340, and other rich comparisons as needed. (If you really need the ‘cmp()’ functionality, you could use the expression ‘(a > b) - (a < b)’ as the equivalent for ‘cmp(a, b)’.)  File: python.info, Node: Integers, Next: Text Vs Data Instead Of Unicode Vs 8-bit, Prev: Ordering Comparisons, Up: Common Stumbling Blocks 1.9.1.4 Integers ................ * PEP 237(1): Essentially, ‘long’ renamed to *note int: 184. That is, there is only one built-in integral type, named *note int: 184.; but it behaves mostly like the old ‘long’ type. * PEP 238(2): An expression like ‘1/2’ returns a float. Use ‘1//2’ to get the truncating behavior. (The latter syntax has existed for years, at least since Python 2.2.) * The ‘sys.maxint’ constant was removed, since there is no longer a limit to the value of integers. However, *note sys.maxsize: b43. can be used as an integer larger than any practical list or string index. It conforms to the implementation’s “natural” integer size and is typically the same as ‘sys.maxint’ in previous releases on the same platform (assuming the same build options). * The *note repr(): 7cc. of a long integer doesn’t include the trailing ‘L’ anymore, so code that unconditionally strips that character will chop off the last digit instead. (Use *note str(): 330. instead.) * Octal literals are no longer of the form ‘0720’; use ‘0o720’ instead. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0237 (2) https://www.python.org/dev/peps/pep-0238  File: python.info, Node: Text Vs Data Instead Of Unicode Vs 8-bit, Prev: Integers, Up: Common Stumbling Blocks 1.9.1.5 Text Vs. Data Instead Of Unicode Vs. 8-bit .................................................. Everything you thought you knew about binary data and Unicode has changed. * Python 3.0 uses the concepts of `text' and (binary) `data' instead of Unicode strings and 8-bit strings. All text is Unicode; however `encoded' Unicode is represented as binary data. The type used to hold text is *note str: 330, the type used to hold data is *note bytes: 331. The biggest difference with the 2.x situation is that any attempt to mix text and data in Python 3.0 raises *note TypeError: 192, whereas if you were to mix Unicode and 8-bit strings in Python 2.x, it would work if the 8-bit string happened to contain only 7-bit (ASCII) bytes, but you would get *note UnicodeDecodeError: 1fd. if it contained non-ASCII values. This value-specific behavior has caused numerous sad faces over the years. * As a consequence of this change in philosophy, pretty much all code that uses Unicode, encodings or binary data most likely has to change. The change is for the better, as in the 2.x world there were numerous bugs having to do with mixing encoded and unencoded text. To be prepared in Python 2.x, start using ‘unicode’ for all unencoded text, and *note str: 330. for binary or encoded data only. Then the ‘2to3’ tool will do most of the work for you. * You can no longer use ‘u"..."’ literals for Unicode text. However, you must use ‘b"..."’ literals for binary data. * As the *note str: 330. and *note bytes: 331. types cannot be mixed, you must always explicitly convert between them. Use *note str.encode(): c37. to go from *note str: 330. to *note bytes: 331, and *note bytes.decode(): c38. to go from *note bytes: 331. to *note str: 330. You can also use ‘bytes(s, encoding=...)’ and ‘str(b, encoding=...)’, respectively. * Like *note str: 330, the *note bytes: 331. type is immutable. There is a separate `mutable' type to hold buffered binary data, *note bytearray: 332. Nearly all APIs that accept *note bytes: 331. also accept *note bytearray: 332. The mutable API is based on ‘collections.MutableSequence’. * All backslashes in raw string literals are interpreted literally. This means that ‘'\U'’ and ‘'\u'’ escapes in raw strings are not treated specially. For example, ‘r'\u20ac'’ is a string of 6 characters in Python 3.0, whereas in 2.6, ‘ur'\u20ac'’ was the single “euro” character. (Of course, this change only affects raw string literals; the euro character is ‘'\u20ac'’ in Python 3.0.) * The built-in ‘basestring’ abstract type was removed. Use *note str: 330. instead. The *note str: 330. and *note bytes: 331. types don’t have functionality enough in common to warrant a shared base class. The ‘2to3’ tool (see below) replaces every occurrence of ‘basestring’ with *note str: 330. * Files opened as text files (still the default mode for *note open(): 4f0.) always use an encoding to map between strings (in memory) and bytes (on disk). Binary files (opened with a ‘b’ in the mode argument) always use bytes in memory. This means that if a file is opened using an incorrect mode or encoding, I/O will likely fail loudly, instead of silently producing incorrect data. It also means that even Unix users will have to specify the correct mode (text or binary) when opening a file. There is a platform-dependent default encoding, which on Unixy platforms can be set with the ‘LANG’ environment variable (and sometimes also with some other platform-specific locale-related environment variables). In many cases, but not all, the system default is UTF-8; you should never count on this default. Any application reading or writing more than pure ASCII text should probably have a way to override the encoding. There is no longer any need for using the encoding-aware streams in the *note codecs: 1c. module. * The initial values of *note sys.stdin: 30d, *note sys.stdout: 30e. and *note sys.stderr: 30f. are now unicode-only text files (i.e., they are instances of *note io.TextIOBase: c39.). To read and write bytes data with these streams, you need to use their *note io.TextIOBase.buffer: c3a. attribute. * Filenames are passed to and returned from APIs as (Unicode) strings. This can present platform-specific problems because on some platforms filenames are arbitrary byte strings. (On the other hand, on Windows filenames are natively stored as Unicode.) As a work-around, most APIs (e.g. *note open(): 4f0. and many functions in the *note os: c4. module) that take filenames accept *note bytes: 331. objects as well as strings, and a few APIs have a way to ask for a *note bytes: 331. return value. Thus, *note os.listdir(): a41. returns a list of *note bytes: 331. instances if the argument is a *note bytes: 331. instance, and *note os.getcwdb(): 2b8. returns the current working directory as a *note bytes: 331. instance. Note that when *note os.listdir(): a41. returns a list of strings, filenames that cannot be decoded properly are omitted rather than raising *note UnicodeError: c3b. * Some system APIs like *note os.environ: b37. and *note sys.argv: bfb. can also present problems when the bytes made available by the system is not interpretable using the default encoding. Setting the ‘LANG’ variable and rerunning the program is probably the best approach. * PEP 3138(1): The *note repr(): 7cc. of a string no longer escapes non-ASCII characters. It still escapes control characters and code points with non-printable status in the Unicode standard, however. * PEP 3120(2): The default source encoding is now UTF-8. * PEP 3131(3): Non-ASCII letters are now allowed in identifiers. (However, the standard library remains ASCII-only with the exception of contributor names in comments.) * The ‘StringIO’ and ‘cStringIO’ modules are gone. Instead, import the *note io: a1. module and use *note io.StringIO: 82d. or *note io.BytesIO: 79b. for text and data respectively. * See also the *note Unicode HOWTO: c3c, which was updated for Python 3.0. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3138 (2) https://www.python.org/dev/peps/pep-3120 (3) https://www.python.org/dev/peps/pep-3131  File: python.info, Node: Overview Of Syntax Changes, Next: Changes Already Present In Python 2 6, Prev: Common Stumbling Blocks, Up: What’s New In Python 3 0 1.9.2 Overview Of Syntax Changes -------------------------------- This section gives a brief overview of every `syntactic' change in Python 3.0. * Menu: * New Syntax:: * Changed Syntax:: * Removed Syntax::  File: python.info, Node: New Syntax, Next: Changed Syntax, Up: Overview Of Syntax Changes 1.9.2.1 New Syntax .................. * PEP 3107(1): Function argument and return value annotations. This provides a standardized way of annotating a function’s parameters and return value. There are no semantics attached to such annotations except that they can be introspected at runtime using the ‘__annotations__’ attribute. The intent is to encourage experimentation through metaclasses, decorators or frameworks. * PEP 3102(2): Keyword-only arguments. Named parameters occurring after ‘*args’ in the parameter list `must' be specified using keyword syntax in the call. You can also use a bare ‘*’ in the parameter list to indicate that you don’t accept a variable-length argument list, but you do have keyword-only arguments. * Keyword arguments are allowed after the list of base classes in a class definition. This is used by the new convention for specifying a metaclass (see next section), but can be used for other purposes as well, as long as the metaclass supports it. * PEP 3104(3): *note nonlocal: c3f. statement. Using ‘nonlocal x’ you can now assign directly to a variable in an outer (but non-global) scope. ‘nonlocal’ is a new reserved word. * PEP 3132(4): Extended Iterable Unpacking. You can now write things like ‘a, b, *rest = some_sequence’. And even ‘*rest, a = stuff’. The ‘rest’ object is always a (possibly empty) list; the right-hand side may be any iterable. Example: (a, *rest, b) = range(5) This sets `a' to ‘0’, `b' to ‘4’, and `rest' to ‘[1, 2, 3]’. * Dictionary comprehensions: ‘{k: v for k, v in stuff}’ means the same thing as ‘dict(stuff)’ but is more flexible. (This is PEP 274(5) vindicated. :-) * Set literals, e.g. ‘{1, 2}’. Note that ‘{}’ is an empty dictionary; use ‘set()’ for an empty set. Set comprehensions are also supported; e.g., ‘{x for x in stuff}’ means the same thing as ‘set(stuff)’ but is more flexible. * New octal literals, e.g. ‘0o720’ (already in 2.6). The old octal literals (‘0720’) are gone. * New binary literals, e.g. ‘0b1010’ (already in 2.6), and there is a new corresponding built-in function, *note bin(): c40. * Bytes literals are introduced with a leading ‘b’ or ‘B’, and there is a new corresponding built-in function, *note bytes(): 331. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3107 (2) https://www.python.org/dev/peps/pep-3102 (3) https://www.python.org/dev/peps/pep-3104 (4) https://www.python.org/dev/peps/pep-3132 (5) https://www.python.org/dev/peps/pep-0274  File: python.info, Node: Changed Syntax, Next: Removed Syntax, Prev: New Syntax, Up: Overview Of Syntax Changes 1.9.2.2 Changed Syntax ...................... * PEP 3109(1) and PEP 3134(2): new *note raise: c42. statement syntax: ‘raise [`expr' [from `expr']]’. See below. * ‘as’ and *note with: 6e9. are now reserved words. (Since 2.6, actually.) * ‘True’, ‘False’, and ‘None’ are reserved words. (2.6 partially enforced the restrictions on ‘None’ already.) * Change from *note except: b3e. `exc', `var' to ‘except’ `exc' ‘as’ `var'. See PEP 3110(3). * PEP 3115(4): New Metaclass Syntax. Instead of: class C: __metaclass__ = M ... you must now use: class C(metaclass=M): ... The module-global ‘__metaclass__’ variable is no longer supported. (It was a crutch to make it easier to default to new-style classes without deriving every class from *note object: 2b0.) * List comprehensions no longer support the syntactic form ‘[... for `var' in `item1', `item2', ...]’. Use ‘[... for `var' in (`item1', `item2', ...)]’ instead. Also note that list comprehensions have different semantics: they are closer to syntactic sugar for a generator expression inside a *note list(): 262. constructor, and in particular the loop control variables are no longer leaked into the surrounding scope. * The `ellipsis' (‘...’) can be used as an atomic expression anywhere. (Previously it was only allowed in slices.) Also, it `must' now be spelled as ‘...’. (Previously it could also be spelled as ‘. . .’, by a mere accident of the grammar.) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3109 (2) https://www.python.org/dev/peps/pep-3134 (3) https://www.python.org/dev/peps/pep-3110 (4) https://www.python.org/dev/peps/pep-3115  File: python.info, Node: Removed Syntax, Prev: Changed Syntax, Up: Overview Of Syntax Changes 1.9.2.3 Removed Syntax ...................... * PEP 3113(1): Tuple parameter unpacking removed. You can no longer write ‘def foo(a, (b, c)): ...’. Use ‘def foo(a, b_c): b, c = b_c’ instead. * Removed backticks (use *note repr(): 7cc. instead). * Removed ‘<>’ (use ‘!=’ instead). * Removed keyword: *note exec(): c44. is no longer a keyword; it remains as a function. (Fortunately the function syntax was also accepted in 2.x.) Also note that *note exec(): c44. no longer takes a stream argument; instead of ‘exec(f)’ you can use ‘exec(f.read())’. * Integer literals no longer support a trailing ‘l’ or ‘L’. * String literals no longer support a leading ‘u’ or ‘U’. * The *note from: c45. `module' *note import: c1d. ‘*’ syntax is only allowed at the module level, no longer inside functions. * The only acceptable syntax for relative imports is ‘from .[`module'] import `name'’. All *note import: c1d. forms not starting with ‘.’ are interpreted as absolute imports. ( PEP 328(2)) * Classic classes are gone. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3113 (2) https://www.python.org/dev/peps/pep-0328  File: python.info, Node: Changes Already Present In Python 2 6, Next: Library Changes, Prev: Overview Of Syntax Changes, Up: What’s New In Python 3 0 1.9.3 Changes Already Present In Python 2.6 ------------------------------------------- Since many users presumably make the jump straight from Python 2.5 to Python 3.0, this section reminds the reader of new features that were originally designed for Python 3.0 but that were back-ported to Python 2.6. The corresponding sections in *note What’s New in Python 2.6: c47. should be consulted for longer descriptions. * *note PEP 343; The ‘with’ statement: c48. The *note with: 6e9. statement is now a standard feature and no longer needs to be imported from the *note __future__: 0. Also check out *note Writing Context Managers: c49. and *note The contextlib module: c4a. * *note PEP 366; Explicit Relative Imports From a Main Module: c4b. This enhances the usefulness of the *note -m: 337. option when the referenced module lives in a package. * *note PEP 370; Per-user site-packages Directory: c4c. * *note PEP 371; The multiprocessing Package: c4d. * *note PEP 3101; Advanced String Formatting: c4e. Note: the 2.6 description mentions the *note format(): 4db. method for both 8-bit and Unicode strings. In 3.0, only the *note str: 330. type (text strings with Unicode support) supports this method; the *note bytes: 331. type does not. The plan is to eventually make this the only API for string formatting, and to start deprecating the ‘%’ operator in Python 3.1. * *note PEP 3105; print As a Function: c4f. This is now a standard feature and no longer needs to be imported from *note __future__: 0. More details were given above. * *note PEP 3110; Exception-Handling Changes: c50. The *note except: b3e. `exc' ‘as’ `var' syntax is now standard and ‘except’ `exc', `var' is no longer supported. (Of course, the ‘as’ `var' part is still optional.) * *note PEP 3112; Byte Literals: c51. The ‘b"..."’ string literal notation (and its variants like ‘b'...'’, ‘b"""..."""’, and ‘br"..."’) now produces a literal of type *note bytes: 331. * *note PEP 3116; New I/O Library: c52. The *note io: a1. module is now the standard way of doing file I/O. The built-in *note open(): 4f0. function is now an alias for *note io.open(): 65a. and has additional keyword arguments `encoding', `errors', `newline' and `closefd'. Also note that an invalid `mode' argument now raises *note ValueError: 1fb, not *note IOError: 992. The binary file object underlying a text file object can be accessed as ‘f.buffer’ (but beware that the text object maintains a buffer of itself in order to speed up the encoding and decoding operations). * *note PEP 3118; Revised Buffer Protocol: c53. The old builtin ‘buffer()’ is now really gone; the new builtin *note memoryview(): 25c. provides (mostly) similar functionality. * *note PEP 3119; Abstract Base Classes: c54. The *note abc: 4. module and the ABCs defined in the *note collections: 1e. module plays a somewhat more prominent role in the language now, and built-in collection types like *note dict: 1b8. and *note list: 262. conform to the ‘collections.MutableMapping’ and ‘collections.MutableSequence’ ABCs, respectively. * *note PEP 3127; Integer Literal Support and Syntax: c55. As mentioned above, the new octal literal notation is the only one supported, and binary literals have been added. * *note PEP 3129; Class Decorators: c56. * *note PEP 3141; A Type Hierarchy for Numbers: c57. The *note numbers: c1. module is another new use of ABCs, defining Python’s “numeric tower”. Also note the new *note fractions: 83. module which implements *note numbers.Rational: c58.  File: python.info, Node: Library Changes, Next: PEP 3101 A New Approach To String Formatting, Prev: Changes Already Present In Python 2 6, Up: What’s New In Python 3 0 1.9.4 Library Changes --------------------- Due to time constraints, this document does not exhaustively cover the very extensive changes to the standard library. PEP 3108(1) is the reference for the major changes to the library. Here’s a capsule review: * Many old modules were removed. Some, like ‘gopherlib’ (no longer used) and ‘md5’ (replaced by *note hashlib: 8d.), were already deprecated by PEP 4(2). Others were removed as a result of the removal of support for various platforms such as Irix, BeOS and Mac OS 9 (see PEP 11(3)). Some modules were also selected for removal in Python 3.0 due to lack of use or because a better replacement exists. See PEP 3108(4) for an exhaustive list. * The ‘bsddb3’ package was removed because its presence in the core standard library has proved over time to be a particular burden for the core developers due to testing instability and Berkeley DB’s release schedule. However, the package is alive and well, externally maintained at ‘https://www.jcea.es/programacion/pybsddb.htm’. * Some modules were renamed because their old name disobeyed PEP 8(5), or for various other reasons. Here’s the list: Old Name New Name -------------------------------------------------------- _winreg winreg ConfigParser configparser copy_reg copyreg Queue queue SocketServer socketserver markupbase _markupbase repr reprlib test.test_support test.support * A common pattern in Python 2.x is to have one version of a module implemented in pure Python, with an optional accelerated version implemented as a C extension; for example, *note pickle: ca. and ‘cPickle’. This places the burden of importing the accelerated version and falling back on the pure Python version on each user of these modules. In Python 3.0, the accelerated versions are considered implementation details of the pure Python versions. Users should always import the standard version, which attempts to import the accelerated version and falls back to the pure Python version. The *note pickle: ca. / ‘cPickle’ pair received this treatment. The *note profile: d3. module is on the list for 3.1. The ‘StringIO’ module has been turned into a class in the *note io: a1. module. * Some related modules have been grouped into packages, and usually the submodule names have been simplified. The resulting new packages are: * *note dbm: 32. (‘anydbm’, ‘dbhash’, *note dbm: 32, ‘dumbdbm’, ‘gdbm’, ‘whichdb’). * *note html: 90. (‘HTMLParser’, ‘htmlentitydefs’). * *note http: 93. (‘httplib’, ‘BaseHTTPServer’, ‘CGIHTTPServer’, ‘SimpleHTTPServer’, ‘Cookie’, ‘cookielib’). * *note tkinter: 10c. (all ‘Tkinter’-related modules except *note turtle: 116.). The target audience of *note turtle: 116. doesn’t really care about *note tkinter: 10c. Also note that as of Python 2.6, the functionality of *note turtle: 116. has been greatly enhanced. * *note urllib: 11d. (*note urllib: 11d, ‘urllib2’, ‘urlparse’, ‘robotparse’). * ‘xmlrpc’ (‘xmlrpclib’, ‘DocXMLRPCServer’, ‘SimpleXMLRPCServer’). Some other changes to standard library modules, not covered by PEP 3108(6): * Killed ‘sets’. Use the built-in *note set(): b6f. class. * Cleanup of the *note sys: fd. module: removed ‘sys.exitfunc()’, ‘sys.exc_clear()’, ‘sys.exc_type’, ‘sys.exc_value’, ‘sys.exc_traceback’. (Note that *note sys.last_type: c5a. etc. remain.) * Cleanup of the *note array.array: 451. type: the ‘read()’ and ‘write()’ methods are gone; use ‘fromfile()’ and ‘tofile()’ instead. Also, the ‘'c'’ typecode for array is gone – use either ‘'b'’ for bytes or ‘'u'’ for Unicode characters. * Cleanup of the *note operator: c2. module: removed ‘sequenceIncludes()’ and ‘isCallable()’. * Cleanup of the ‘thread’ module: ‘acquire_lock()’ and ‘release_lock()’ are gone; use ‘acquire()’ and ‘release()’ instead. * Cleanup of the *note random: dc. module: removed the ‘jumpahead()’ API. * The ‘new’ module is gone. * The functions ‘os.tmpnam()’, ‘os.tempnam()’ and ‘os.tmpfile()’ have been removed in favor of the *note tempfile: 103. module. * The *note tokenize: 111. module has been changed to work with bytes. The main entry point is now *note tokenize.tokenize(): c5b, instead of generate_tokens. * ‘string.letters’ and its friends (‘string.lowercase’ and ‘string.uppercase’) are gone. Use *note string.ascii_letters: c5c. etc. instead. (The reason for the removal is that ‘string.letters’ and friends had locale-specific behavior, which is a bad idea for such attractively-named global “constants”.) * Renamed module ‘__builtin__’ to *note builtins: 13. (removing the underscores, adding an ‘s’). The ‘__builtins__’ variable found in most global namespaces is unchanged. To modify a builtin, you should use *note builtins: 13, not ‘__builtins__’! ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3108 (2) https://www.python.org/dev/peps/pep-0004 (3) https://www.python.org/dev/peps/pep-0011 (4) https://www.python.org/dev/peps/pep-3108 (5) https://www.python.org/dev/peps/pep-0008 (6) https://www.python.org/dev/peps/pep-3108  File: python.info, Node: PEP 3101 A New Approach To String Formatting, Next: Changes To Exceptions, Prev: Library Changes, Up: What’s New In Python 3 0 1.9.5 `PEP 3101': A New Approach To String Formatting ----------------------------------------------------- * A new system for built-in string formatting operations replaces the ‘%’ string formatting operator. (However, the ‘%’ operator is still supported; it will be deprecated in Python 3.1 and removed from the language at some later time.) Read PEP 3101(1) for the full scoop. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3101  File: python.info, Node: Changes To Exceptions, Next: Miscellaneous Other Changes, Prev: PEP 3101 A New Approach To String Formatting, Up: What’s New In Python 3 0 1.9.6 Changes To Exceptions --------------------------- The APIs for raising and catching exception have been cleaned up and new powerful features added: * PEP 352(1): All exceptions must be derived (directly or indirectly) from *note BaseException: 1a8. This is the root of the exception hierarchy. This is not new as a recommendation, but the `requirement' to inherit from *note BaseException: 1a8. is new. (Python 2.6 still allowed classic classes to be raised, and placed no restriction on what you can catch.) As a consequence, string exceptions are finally truly and utterly dead. * Almost all exceptions should actually derive from *note Exception: 1a9.; *note BaseException: 1a8. should only be used as a base class for exceptions that should only be handled at the top level, such as *note SystemExit: 5fc. or *note KeyboardInterrupt: 197. The recommended idiom for handling all exceptions except for this latter category is to use *note except: b3e. *note Exception: 1a9. * ‘StandardError’ was removed. * Exceptions no longer behave as sequences. Use the ‘args’ attribute instead. * PEP 3109(2): Raising exceptions. You must now use ‘raise `Exception'(`args')’ instead of ‘raise `Exception', `args'’. Additionally, you can no longer explicitly specify a traceback; instead, if you `have' to do this, you can assign directly to the ‘__traceback__’ attribute (see below). * PEP 3110(3): Catching exceptions. You must now use ‘except `SomeException' as `variable'’ instead of ‘except `SomeException', `variable'’. Moreover, the `variable' is explicitly deleted when the *note except: b3e. block is left. * PEP 3134(4): Exception chaining. There are two cases: implicit chaining and explicit chaining. Implicit chaining happens when an exception is raised in an *note except: b3e. or *note finally: 182. handler block. This usually happens due to a bug in the handler block; we call this a `secondary' exception. In this case, the original exception (that was being handled) is saved as the ‘__context__’ attribute of the secondary exception. Explicit chaining is invoked with this syntax: raise SecondaryException() from primary_exception (where `primary_exception' is any expression that produces an exception object, probably an exception that was previously caught). In this case, the primary exception is stored on the ‘__cause__’ attribute of the secondary exception. The traceback printed when an unhandled exception occurs walks the chain of ‘__cause__’ and ‘__context__’ attributes and prints a separate traceback for each component of the chain, with the primary exception at the top. (Java users may recognize this behavior.) * PEP 3134(5): Exception objects now store their traceback as the ‘__traceback__’ attribute. This means that an exception object now contains all the information pertaining to an exception, and there are fewer reasons to use *note sys.exc_info(): c5f. (though the latter is not removed). * A few exception messages are improved when Windows fails to load an extension module. For example, ‘error code 193’ is now ‘%1 is not a valid Win32 application’. Strings now deal with non-English locales. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0352 (2) https://www.python.org/dev/peps/pep-3109 (3) https://www.python.org/dev/peps/pep-3110 (4) https://www.python.org/dev/peps/pep-3134 (5) https://www.python.org/dev/peps/pep-3134  File: python.info, Node: Miscellaneous Other Changes, Next: Build and C API Changes<7>, Prev: Changes To Exceptions, Up: What’s New In Python 3 0 1.9.7 Miscellaneous Other Changes --------------------------------- * Menu: * Operators And Special Methods:: * Builtins::  File: python.info, Node: Operators And Special Methods, Next: Builtins, Up: Miscellaneous Other Changes 1.9.7.1 Operators And Special Methods ..................................... * ‘!=’ now returns the opposite of ‘==’, unless ‘==’ returns *note NotImplemented: 84c. * The concept of “unbound methods” has been removed from the language. When referencing a method as a class attribute, you now get a plain function object. * ‘__getslice__()’, ‘__setslice__()’ and ‘__delslice__()’ were killed. The syntax ‘a[i:j]’ now translates to ‘a.__getitem__(slice(i, j))’ (or *note __setitem__(): c62. or *note __delitem__(): c63, when used as an assignment or deletion target, respectively). * PEP 3114(1): the standard *note next(): 682. method has been renamed to *note __next__(): c64. * The ‘__oct__()’ and ‘__hex__()’ special methods are removed – *note oct(): c65. and *note hex(): c66. use *note __index__(): 18a. now to convert the argument to an integer. * Removed support for ‘__members__’ and ‘__methods__’. * The function attributes named ‘func_X’ have been renamed to use the ‘__X__’ form, freeing up these names in the function attribute namespace for user-defined attributes. To wit, ‘func_closure’, ‘func_code’, ‘func_defaults’, ‘func_dict’, ‘func_doc’, ‘func_globals’, ‘func_name’ were renamed to ‘__closure__’, ‘__code__’, ‘__defaults__’, *note __dict__: 4fc, ‘__doc__’, ‘__globals__’, *note __name__: c67, respectively. * ‘__nonzero__()’ is now *note __bool__(): c68. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3114  File: python.info, Node: Builtins, Prev: Operators And Special Methods, Up: Miscellaneous Other Changes 1.9.7.2 Builtins ................ * PEP 3135(1): New *note super(): 4e2. You can now invoke *note super(): 4e2. without arguments and (assuming this is in a regular instance method defined inside a *note class: c6a. statement) the right class and instance will automatically be chosen. With arguments, the behavior of *note super(): 4e2. is unchanged. * PEP 3111(2): ‘raw_input()’ was renamed to *note input(): c6b. That is, the new *note input(): c6b. function reads a line from *note sys.stdin: 30d. and returns it with the trailing newline stripped. It raises *note EOFError: c6c. if the input is terminated prematurely. To get the old behavior of *note input(): c6b, use ‘eval(input())’. * A new built-in function *note next(): 682. was added to call the *note __next__(): c64. method on an object. * The *note round(): c6d. function rounding strategy and return type have changed. Exact halfway cases are now rounded to the nearest even result instead of away from zero. (For example, ‘round(2.5)’ now returns ‘2’ rather than ‘3’.) ‘round(x[, n])’ now delegates to ‘x.__round__([n])’ instead of always returning a float. It generally returns an integer when called with a single argument and a value of the same type as ‘x’ when called with two arguments. * Moved ‘intern()’ to *note sys.intern(): c6e. * Removed: ‘apply()’. Instead of ‘apply(f, args)’ use ‘f(*args)’. * Removed *note callable(): b44. Instead of ‘callable(f)’ you can use ‘isinstance(f, collections.Callable)’. The ‘operator.isCallable()’ function is also gone. * Removed ‘coerce()’. This function no longer serves a purpose now that classic classes are gone. * Removed ‘execfile()’. Instead of ‘execfile(fn)’ use ‘exec(open(fn).read())’. * Removed the ‘file’ type. Use *note open(): 4f0. There are now several different kinds of streams that open can return in the *note io: a1. module. * Removed ‘reduce()’. Use *note functools.reduce(): c6f. if you really need it; however, 99 percent of the time an explicit *note for: c30. loop is more readable. * Removed ‘reload()’. Use *note imp.reload(): c70. * Removed. ‘dict.has_key()’ – use the *note in: 7a3. operator instead. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3135 (2) https://www.python.org/dev/peps/pep-3111  File: python.info, Node: Build and C API Changes<7>, Next: Performance, Prev: Miscellaneous Other Changes, Up: What’s New In Python 3 0 1.9.8 Build and C API Changes ----------------------------- Due to time constraints, here is a `very' incomplete list of changes to the C API. * Support for several platforms was dropped, including but not limited to Mac OS 9, BeOS, RISCOS, Irix, and Tru64. * PEP 3118(1): New Buffer API. * PEP 3121(2): Extension Module Initialization & Finalization. * PEP 3123(3): Making *note PyObject_HEAD: c72. conform to standard C. * No more C API support for restricted execution. * ‘PyNumber_Coerce()’, ‘PyNumber_CoerceEx()’, ‘PyMember_Get()’, and ‘PyMember_Set()’ C APIs are removed. * New C API *note PyImport_ImportModuleNoBlock(): 9c1, works like *note PyImport_ImportModule(): c73. but won’t block on the import lock (returning an error instead). * Renamed the boolean conversion C-level slot and method: ‘nb_nonzero’ is now ‘nb_bool’. * Removed ‘METH_OLDARGS’ and ‘WITH_CYCLE_GC’ from the C API. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3118 (2) https://www.python.org/dev/peps/pep-3121 (3) https://www.python.org/dev/peps/pep-3123  File: python.info, Node: Performance, Next: Porting To Python 3 0, Prev: Build and C API Changes<7>, Up: What’s New In Python 3 0 1.9.9 Performance ----------------- The net result of the 3.0 generalizations is that Python 3.0 runs the pystone benchmark around 10% slower than Python 2.5. Most likely the biggest cause is the removal of special-casing for small integers. There’s room for improvement, but it will happen after 3.0 is released!  File: python.info, Node: Porting To Python 3 0, Prev: Performance, Up: What’s New In Python 3 0 1.9.10 Porting To Python 3.0 ---------------------------- For porting existing Python 2.5 or 2.6 source code to Python 3.0, the best strategy is the following: 0. (Prerequisite:) Start with excellent test coverage. 1. Port to Python 2.6. This should be no more work than the average port from Python 2.x to Python 2.(x+1). Make sure all your tests pass. 2. (Still using 2.6:) Turn on the ‘-3’ command line switch. This enables warnings about features that will be removed (or change) in 3.0. Run your test suite again, and fix code that you get warnings about until there are no warnings left, and all your tests still pass. 3. Run the ‘2to3’ source-to-source translator over your source code tree. (See *note 2to3 - Automated Python 2 to 3 code translation: c76. for more on this tool.) Run the result of the translation under Python 3.0. Manually fix up any remaining issues, fixing problems until all tests pass again. It is not recommended to try to write source code that runs unchanged under both Python 2.6 and 3.0; you’d have to use a very contorted coding style, e.g. avoiding ‘print’ statements, metaclasses, and much more. If you are maintaining a library that needs to support both Python 2.6 and Python 3.0, the best approach is to modify step 3 above by editing the 2.6 version of the source code and running the ‘2to3’ translator again, rather than editing the 3.0 version of the source code. For porting C extensions to Python 3.0, please see *note Porting Extension Modules to Python 3: c77.  File: python.info, Node: What’s New in Python 2 7, Next: What’s New in Python 2 6, Prev: What’s New In Python 3 0, Up: What’s New in Python 1.10 What’s New in Python 2.7 ============================= Author: A.M. Kuchling (amk at amk.ca) This article explains the new features in Python 2.7. Python 2.7 was released on July 3, 2010. Numeric handling has been improved in many ways, for both floating-point numbers and for the *note Decimal: 188. class. There are some useful additions to the standard library, such as a greatly enhanced *note unittest: 11b. module, the *note argparse: 6. module for parsing command-line options, convenient *note OrderedDict: 1b9. and *note Counter: 9da. classes in the *note collections: 1e. module, and many other improvements. Python 2.7 is planned to be the last of the 2.x releases, so we worked on making it a good release for the long term. To help with porting to Python 3, several new features from the Python 3.x series have been included in 2.7. This article doesn’t attempt to provide a complete specification of the new features, but instead provides a convenient overview. For full details, you should refer to the documentation for Python 2.7 at ‘https://docs.python.org’. If you want to understand the rationale for the design and implementation, refer to the PEP for a particular new feature or the issue on ‘https://bugs.python.org’ in which a change was discussed. Whenever possible, “What’s New in Python” links to the bug/patch item for each change. * Menu: * The Future for Python 2.x: The Future for Python 2 x. * Changes to the Handling of Deprecation Warnings:: * Python 3.1 Features: Python 3 1 Features. * PEP 372; Adding an Ordered Dictionary to collections: PEP 372 Adding an Ordered Dictionary to collections. * PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator<2>. * PEP 389; The argparse Module for Parsing Command Lines: PEP 389 The argparse Module for Parsing Command Lines. * PEP 391; Dictionary-Based Configuration For Logging: PEP 391 Dictionary-Based Configuration For Logging. * PEP 3106; Dictionary Views: PEP 3106 Dictionary Views. * PEP 3137; The memoryview Object: PEP 3137 The memoryview Object. * Other Language Changes: Other Language Changes<9>. * New and Improved Modules:: * Build and C API Changes: Build and C API Changes<8>. * Other Changes and Fixes:: * Porting to Python 2.7: Porting to Python 2 7. * New Features Added to Python 2.7 Maintenance Releases: New Features Added to Python 2 7 Maintenance Releases. * Acknowledgements::  File: python.info, Node: The Future for Python 2 x, Next: Changes to the Handling of Deprecation Warnings, Up: What’s New in Python 2 7 1.10.1 The Future for Python 2.x -------------------------------- Python 2.7 is the last major release in the 2.x series, as the Python maintainers have shifted the focus of their new feature development efforts to the Python 3.x series. This means that while Python 2 continues to receive bug fixes, and to be updated to build correctly on new hardware and versions of supported operated systems, there will be no new full feature releases for the language or standard library. However, while there is a large common subset between Python 2.7 and Python 3, and many of the changes involved in migrating to that common subset, or directly to Python 3, can be safely automated, some other changes (notably those associated with Unicode handling) may require careful consideration, and preferably robust automated regression test suites, to migrate effectively. This means that Python 2.7 will remain in place for a long time, providing a stable and supported base platform for production systems that have not yet been ported to Python 3. The full expected lifecycle of the Python 2.7 series is detailed in PEP 373(1). Some key consequences of the long-term significance of 2.7 are: * As noted above, the 2.7 release has a much longer period of maintenance when compared to earlier 2.x versions. Python 2.7 is currently expected to remain supported by the core development team (receiving security updates and other bug fixes) until at least 2020 (10 years after its initial release, compared to the more typical support period of 18–24 months). * As the Python 2.7 standard library ages, making effective use of the Python Package Index (either directly or via a redistributor) becomes more important for Python 2 users. In addition to a wide variety of third party packages for various tasks, the available packages include backports of new modules and features from the Python 3 standard library that are compatible with Python 2, as well as various tools and libraries that can make it easier to migrate to Python 3. The Python Packaging User Guide(2) provides guidance on downloading and installing software from the Python Package Index. * While the preferred approach to enhancing Python 2 is now the publication of new packages on the Python Package Index, this approach doesn’t necessarily work in all cases, especially those related to network security. In exceptional cases that cannot be handled adequately by publishing new or updated packages on PyPI, the Python Enhancement Proposal process may be used to make the case for adding new features directly to the Python 2 standard library. Any such additions, and the maintenance releases where they were added, will be noted in the *note New Features Added to Python 2.7 Maintenance Releases: c7c. section below. For projects wishing to migrate from Python 2 to Python 3, or for library and framework developers wishing to support users on both Python 2 and Python 3, there are a variety of tools and guides available to help decide on a suitable approach and manage some of the technical details involved. The recommended starting point is the *note Porting Python 2 Code to Python 3: c7d. HOWTO guide. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0373 (2) https://packaging.python.org  File: python.info, Node: Changes to the Handling of Deprecation Warnings, Next: Python 3 1 Features, Prev: The Future for Python 2 x, Up: What’s New in Python 2 7 1.10.2 Changes to the Handling of Deprecation Warnings ------------------------------------------------------ For Python 2.7, a policy decision was made to silence warnings only of interest to developers by default. *note DeprecationWarning: 278. and its descendants are now ignored unless otherwise requested, preventing users from seeing warnings triggered by an application. This change was also made in the branch that became Python 3.2. (Discussed on stdlib-sig and carried out in bpo-7319(1).) In previous releases, *note DeprecationWarning: 278. messages were enabled by default, providing Python developers with a clear indication of where their code may break in a future major version of Python. However, there are increasingly many users of Python-based applications who are not directly involved in the development of those applications. *note DeprecationWarning: 278. messages are irrelevant to such users, making them worry about an application that’s actually working correctly and burdening application developers with responding to these concerns. You can re-enable display of *note DeprecationWarning: 278. messages by running Python with the *note -Wdefault: 417. (short form: *note -Wd: 417.) switch, or by setting the *note PYTHONWARNINGS: 418. environment variable to ‘"default"’ (or ‘"d"’) before running Python. Python code can also re-enable them by calling ‘warnings.simplefilter('default')’. The ‘unittest’ module also automatically reenables deprecation warnings when running tests. ---------- Footnotes ---------- (1) https://bugs.python.org/issue7319  File: python.info, Node: Python 3 1 Features, Next: PEP 372 Adding an Ordered Dictionary to collections, Prev: Changes to the Handling of Deprecation Warnings, Up: What’s New in Python 2 7 1.10.3 Python 3.1 Features -------------------------- Much as Python 2.6 incorporated features from Python 3.0, version 2.7 incorporates some of the new features in Python 3.1. The 2.x series continues to provide tools for migrating to the 3.x series. A partial list of 3.1 features that were backported to 2.7: * The syntax for set literals (‘{1,2,3}’ is a mutable set). * Dictionary and set comprehensions (‘{i: i*2 for i in range(3)}’). * Multiple context managers in a single *note with: 6e9. statement. * A new version of the *note io: a1. library, rewritten in C for performance. * The ordered-dictionary type described in *note PEP 372; Adding an Ordered Dictionary to collections: c80. * The new ‘","’ format specifier described in *note PEP 378; Format Specifier for Thousands Separator: c81. * The *note memoryview: 25c. object. * A small subset of the *note importlib: 9b. module, *note described below: c82. * The *note repr(): 7cc. of a float ‘x’ is shorter in many cases: it’s now based on the shortest decimal string that’s guaranteed to round back to ‘x’. As in previous versions of Python, it’s guaranteed that ‘float(repr(x))’ recovers ‘x’. * Float-to-string and string-to-float conversions are correctly rounded. The *note round(): c6d. function is also now correctly rounded. * The *note PyCapsule: c07. type, used to provide a C API for extension modules. * The *note PyLong_AsLongAndOverflow(): bfd. C API function. Other new Python3-mode warnings include: * ‘operator.isCallable()’ and ‘operator.sequenceIncludes()’, which are not supported in 3.x, now trigger warnings. * The ‘-3’ switch now automatically enables the ‘-Qwarn’ switch that causes warnings about using classic division with integers and long integers.  File: python.info, Node: PEP 372 Adding an Ordered Dictionary to collections, Next: PEP 378 Format Specifier for Thousands Separator<2>, Prev: Python 3 1 Features, Up: What’s New in Python 2 7 1.10.4 PEP 372: Adding an Ordered Dictionary to collections ----------------------------------------------------------- Regular Python dictionaries iterate over key/value pairs in arbitrary order. Over the years, a number of authors have written alternative implementations that remember the order that the keys were originally inserted. Based on the experiences from those implementations, 2.7 introduces a new *note OrderedDict: 1b9. class in the *note collections: 1e. module. The *note OrderedDict: 1b9. API provides the same interface as regular dictionaries but iterates over keys and values in a guaranteed order depending on when a key was first inserted: >>> from collections import OrderedDict >>> d = OrderedDict([('first', 1), ... ('second', 2), ... ('third', 3)]) >>> d.items() [('first', 1), ('second', 2), ('third', 3)] If a new entry overwrites an existing entry, the original insertion position is left unchanged: >>> d['second'] = 4 >>> d.items() [('first', 1), ('second', 4), ('third', 3)] Deleting an entry and reinserting it will move it to the end: >>> del d['second'] >>> d['second'] = 5 >>> d.items() [('first', 1), ('third', 3), ('second', 5)] The *note popitem(): c84. method has an optional `last' argument that defaults to ‘True’. If `last' is true, the most recently added key is returned and removed; if it’s false, the oldest key is selected: >>> od = OrderedDict([(x,0) for x in range(20)]) >>> od.popitem() (19, 0) >>> od.popitem() (18, 0) >>> od.popitem(last=False) (0, 0) >>> od.popitem(last=False) (1, 0) Comparing two ordered dictionaries checks both the keys and values, and requires that the insertion order was the same: >>> od1 = OrderedDict([('first', 1), ... ('second', 2), ... ('third', 3)]) >>> od2 = OrderedDict([('third', 3), ... ('first', 1), ... ('second', 2)]) >>> od1 == od2 False >>> # Move 'third' key to the end >>> del od2['third']; od2['third'] = 3 >>> od1 == od2 True Comparing an *note OrderedDict: 1b9. with a regular dictionary ignores the insertion order and just compares the keys and values. How does the *note OrderedDict: 1b9. work? It maintains a doubly-linked list of keys, appending new keys to the list as they’re inserted. A secondary dictionary maps keys to their corresponding list node, so deletion doesn’t have to traverse the entire linked list and therefore remains O(1). The standard library now supports use of ordered dictionaries in several modules. * The ‘ConfigParser’ module uses them by default, meaning that configuration files can now be read, modified, and then written back in their original order. * The *note _asdict(): 1b6. method for *note collections.namedtuple(): 1b7. now returns an ordered dictionary with the values appearing in the same order as the underlying tuple indices. * The *note json: a4. module’s *note JSONDecoder: 607. class constructor was extended with an `object_pairs_hook' parameter to allow ‘OrderedDict’ instances to be built by the decoder. Support was also added for third-party tools like PyYAML(1). See also ........ PEP 372(2) - Adding an ordered dictionary to collections PEP written by Armin Ronacher and Raymond Hettinger; implemented by Raymond Hettinger. ---------- Footnotes ---------- (1) http://pyyaml.org/ (2) https://www.python.org/dev/peps/pep-0372  File: python.info, Node: PEP 378 Format Specifier for Thousands Separator<2>, Next: PEP 389 The argparse Module for Parsing Command Lines, Prev: PEP 372 Adding an Ordered Dictionary to collections, Up: What’s New in Python 2 7 1.10.5 PEP 378: Format Specifier for Thousands Separator -------------------------------------------------------- To make program output more readable, it can be useful to add separators to large numbers, rendering them as 18,446,744,073,709,551,616 instead of 18446744073709551616. The fully general solution for doing this is the *note locale: a9. module, which can use different separators (“,” in North America, “.” in Europe) and different grouping sizes, but *note locale: a9. is complicated to use and unsuitable for multi-threaded applications where different threads are producing output for different locales. Therefore, a simple comma-grouping mechanism has been added to the mini-language used by the *note str.format(): 4da. method. When formatting a floating-point number, simply include a comma between the width and the precision: >>> '{:20,.2f}'.format(18446744073709551616.0) '18,446,744,073,709,551,616.00' When formatting an integer, include the comma after the width: >>> '{:20,d}'.format(18446744073709551616) '18,446,744,073,709,551,616' This mechanism is not adaptable at all; commas are always used as the separator and the grouping is always into three-digit groups. The comma-formatting mechanism isn’t as general as the *note locale: a9. module, but it’s easier to use. See also ........ PEP 378(1) - Format Specifier for Thousands Separator PEP written by Raymond Hettinger; implemented by Eric Smith. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0378  File: python.info, Node: PEP 389 The argparse Module for Parsing Command Lines, Next: PEP 391 Dictionary-Based Configuration For Logging, Prev: PEP 378 Format Specifier for Thousands Separator<2>, Up: What’s New in Python 2 7 1.10.6 PEP 389: The argparse Module for Parsing Command Lines ------------------------------------------------------------- The *note argparse: 6. module for parsing command-line arguments was added as a more powerful replacement for the *note optparse: c3. module. This means Python now supports three different modules for parsing command-line arguments: *note getopt: 87, *note optparse: c3, and *note argparse: 6. The *note getopt: 87. module closely resembles the C library’s ‘getopt()’ function, so it remains useful if you’re writing a Python prototype that will eventually be rewritten in C. *note optparse: c3. becomes redundant, but there are no plans to remove it because there are many scripts still using it, and there’s no automated way to update these scripts. (Making the *note argparse: 6. API consistent with *note optparse: c3.’s interface was discussed but rejected as too messy and difficult.) In short, if you’re writing a new script and don’t need to worry about compatibility with earlier versions of Python, use *note argparse: 6. instead of *note optparse: c3. Here’s an example: import argparse parser = argparse.ArgumentParser(description='Command-line example.') # Add optional switches parser.add_argument('-v', action='store_true', dest='is_verbose', help='produce verbose output') parser.add_argument('-o', action='store', dest='output', metavar='FILE', help='direct output to FILE instead of stdout') parser.add_argument('-C', action='store', type=int, dest='context', metavar='NUM', default=0, help='display NUM lines of added context') # Allow any number of additional arguments. parser.add_argument(nargs='*', action='store', dest='inputs', help='input filenames (default is stdin)') args = parser.parse_args() print args.__dict__ Unless you override it, ‘-h’ and ‘--help’ switches are automatically added, and produce neatly formatted output: -> ./python.exe argparse-example.py --help usage: argparse-example.py [-h] [-v] [-o FILE] [-C NUM] [inputs [inputs ...]] Command-line example. positional arguments: inputs input filenames (default is stdin) optional arguments: -h, --help show this help message and exit -v produce verbose output -o FILE direct output to FILE instead of stdout -C NUM display NUM lines of added context As with *note optparse: c3, the command-line switches and arguments are returned as an object with attributes named by the `dest' parameters: -> ./python.exe argparse-example.py -v {'output': None, 'is_verbose': True, 'context': 0, 'inputs': []} -> ./python.exe argparse-example.py -v -o /tmp/output -C 4 file1 file2 {'output': '/tmp/output', 'is_verbose': True, 'context': 4, 'inputs': ['file1', 'file2']} *note argparse: 6. has much fancier validation than *note optparse: c3.; you can specify an exact number of arguments as an integer, 0 or more arguments by passing ‘'*'’, 1 or more by passing ‘'+'’, or an optional argument with ‘'?'’. A top-level parser can contain sub-parsers to define subcommands that have different sets of switches, as in ‘svn commit’, ‘svn checkout’, etc. You can specify an argument’s type as *note FileType: 820, which will automatically open files for you and understands that ‘'-'’ means standard input or output. See also ........ *note argparse: 6. documentation The documentation page of the argparse module. *note Upgrading optparse code: b29. Part of the Python documentation, describing how to convert code that uses *note optparse: c3. PEP 389(1) - argparse - New Command Line Parsing Module PEP written and implemented by Steven Bethard. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0389  File: python.info, Node: PEP 391 Dictionary-Based Configuration For Logging, Next: PEP 3106 Dictionary Views, Prev: PEP 389 The argparse Module for Parsing Command Lines, Up: What’s New in Python 2 7 1.10.7 PEP 391: Dictionary-Based Configuration For Logging ---------------------------------------------------------- The *note logging: aa. module is very flexible; applications can define a tree of logging subsystems, and each logger in this tree can filter out certain messages, format them differently, and direct messages to a varying number of handlers. All this flexibility can require a lot of configuration. You can write Python statements to create objects and set their properties, but a complex set-up requires verbose but boring code. *note logging: aa. also supports a ‘fileConfig()’ function that parses a file, but the file format doesn’t support configuring filters, and it’s messier to generate programmatically. Python 2.7 adds a ‘dictConfig()’ function that uses a dictionary to configure logging. There are many ways to produce a dictionary from different sources: construct one with code; parse a file containing JSON; or use a YAML parsing library if one is installed. For more information see *note Configuration functions: c88. The following example configures two loggers, the root logger and a logger named “network”. Messages sent to the root logger will be sent to the system log using the syslog protocol, and messages to the “network” logger will be written to a ‘network.log’ file that will be rotated once the log reaches 1MB. import logging import logging.config configdict = { 'version': 1, # Configuration schema in use; must be 1 for now 'formatters': { 'standard': { 'format': ('%(asctime)s %(name)-15s ' '%(levelname)-8s %(message)s')}}, 'handlers': {'netlog': {'backupCount': 10, 'class': 'logging.handlers.RotatingFileHandler', 'filename': '/logs/network.log', 'formatter': 'standard', 'level': 'INFO', 'maxBytes': 1000000}, 'syslog': {'class': 'logging.handlers.SysLogHandler', 'formatter': 'standard', 'level': 'ERROR'}}, # Specify all the subordinate loggers 'loggers': { 'network': { 'handlers': ['netlog'] } }, # Specify properties of the root logger 'root': { 'handlers': ['syslog'] }, } # Set up configuration logging.config.dictConfig(configdict) # As an example, log two error messages logger = logging.getLogger('/') logger.error('Database not found') netlogger = logging.getLogger('network') netlogger.error('Connection failed') Three smaller enhancements to the *note logging: aa. module, all implemented by Vinay Sajip, are: * The *note SysLogHandler: a1e. class now supports syslogging over TCP. The constructor has a `socktype' parameter giving the type of socket to use, either *note socket.SOCK_DGRAM: c89. for UDP or *note socket.SOCK_STREAM: c8a. for TCP. The default protocol remains UDP. * *note Logger: 3a7. instances gained a *note getChild(): c8b. method that retrieves a descendant logger using a relative path. For example, once you retrieve a logger by doing ‘log = getLogger('app')’, calling ‘log.getChild('network.listen')’ is equivalent to ‘getLogger('app.network.listen')’. * The *note LoggerAdapter: c8c. class gained an ‘isEnabledFor()’ method that takes a `level' and returns whether the underlying logger would process a message of that level of importance. See also ........ PEP 391(1) - Dictionary-Based Configuration For Logging PEP written and implemented by Vinay Sajip. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0391  File: python.info, Node: PEP 3106 Dictionary Views, Next: PEP 3137 The memoryview Object, Prev: PEP 391 Dictionary-Based Configuration For Logging, Up: What’s New in Python 2 7 1.10.8 PEP 3106: Dictionary Views --------------------------------- The dictionary methods *note keys(): c2a, *note values(): c2c, and *note items(): c2b. are different in Python 3.x. They return an object called a `view' instead of a fully materialized list. It’s not possible to change the return values of *note keys(): c2a, *note values(): c2c, and *note items(): c2b. in Python 2.7 because too much code would break. Instead the 3.x versions were added under the new names ‘viewkeys()’, ‘viewvalues()’, and ‘viewitems()’. >>> d = dict((i*10, chr(65+i)) for i in range(26)) >>> d {0: 'A', 130: 'N', 10: 'B', 140: 'O', 20: ..., 250: 'Z'} >>> d.viewkeys() dict_keys([0, 130, 10, 140, 20, 150, 30, ..., 250]) Views can be iterated over, but the key and item views also behave like sets. The ‘&’ operator performs intersection, and ‘|’ performs a union: >>> d1 = dict((i*10, chr(65+i)) for i in range(26)) >>> d2 = dict((i**.5, i) for i in range(1000)) >>> d1.viewkeys() & d2.viewkeys() set([0.0, 10.0, 20.0, 30.0]) >>> d1.viewkeys() | range(0, 30) set([0, 1, 130, 3, 4, 5, 6, ..., 120, 250]) The view keeps track of the dictionary and its contents change as the dictionary is modified: >>> vk = d.viewkeys() >>> vk dict_keys([0, 130, 10, ..., 250]) >>> d[260] = '&' >>> vk dict_keys([0, 130, 260, 10, ..., 250]) However, note that you can’t add or remove keys while you’re iterating over the view: >>> for k in vk: ... d[k*2] = k ... Traceback (most recent call last): File "", line 1, in RuntimeError: dictionary changed size during iteration You can use the view methods in Python 2.x code, and the 2to3 converter will change them to the standard *note keys(): c2a, *note values(): c2c, and *note items(): c2b. methods. See also ........ PEP 3106(1) - Revamping dict.keys(), .values() and .items() PEP written by Guido van Rossum. Backported to 2.7 by Alexandre Vassalotti; bpo-1967(2). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3106 (2) https://bugs.python.org/issue1967  File: python.info, Node: PEP 3137 The memoryview Object, Next: Other Language Changes<9>, Prev: PEP 3106 Dictionary Views, Up: What’s New in Python 2 7 1.10.9 PEP 3137: The memoryview Object -------------------------------------- The *note memoryview: 25c. object provides a view of another object’s memory content that matches the *note bytes: 331. type’s interface. >>> import string >>> m = memoryview(string.letters) >>> m >>> len(m) # Returns length of underlying object 52 >>> m[0], m[25], m[26] # Indexing returns one byte ('a', 'z', 'A') >>> m2 = m[0:26] # Slicing returns another memoryview >>> m2 The content of the view can be converted to a string of bytes or a list of integers: >>> m2.tobytes() 'abcdefghijklmnopqrstuvwxyz' >>> m2.tolist() [97, 98, 99, 100, 101, 102, 103, ... 121, 122] >>> *note memoryview: 25c. objects allow modifying the underlying object if it’s a mutable object. >>> m2[0] = 75 Traceback (most recent call last): File "", line 1, in TypeError: cannot modify read-only memory >>> b = bytearray(string.letters) # Creating a mutable object >>> b bytearray(b'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') >>> mb = memoryview(b) >>> mb[0] = '*' # Assign to view, changing the bytearray. >>> b[0:5] # The bytearray has been changed. bytearray(b'*bcde') >>> See also ........ PEP 3137(1) - Immutable Bytes and Mutable Buffer PEP written by Guido van Rossum. Implemented by Travis Oliphant, Antoine Pitrou and others. Backported to 2.7 by Antoine Pitrou; bpo-2396(2). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3137 (2) https://bugs.python.org/issue2396  File: python.info, Node: Other Language Changes<9>, Next: New and Improved Modules, Prev: PEP 3137 The memoryview Object, Up: What’s New in Python 2 7 1.10.10 Other Language Changes ------------------------------ Some smaller changes made to the core Python language are: * The syntax for set literals has been backported from Python 3.x. Curly brackets are used to surround the contents of the resulting mutable set; set literals are distinguished from dictionaries by not containing colons and values. ‘{}’ continues to represent an empty dictionary; use ‘set()’ for an empty set. >>> {1, 2, 3, 4, 5} set([1, 2, 3, 4, 5]) >>> set() # empty set set([]) >>> {} # empty dict {} Backported by Alexandre Vassalotti; bpo-2335(1). * Dictionary and set comprehensions are another feature backported from 3.x, generalizing list/generator comprehensions to use the literal syntax for sets and dictionaries. >>> {x: x*x for x in range(6)} {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25} >>> {('a'*x) for x in range(6)} set(['', 'a', 'aa', 'aaa', 'aaaa', 'aaaaa']) Backported by Alexandre Vassalotti; bpo-2333(2). * The *note with: 6e9. statement can now use multiple context managers in one statement. Context managers are processed from left to right and each one is treated as beginning a new ‘with’ statement. This means that: with A() as a, B() as b: ... suite of statements ... is equivalent to: with A() as a: with B() as b: ... suite of statements ... The ‘contextlib.nested()’ function provides a very similar function, so it’s no longer necessary and has been deprecated. (Proposed in ‘https://codereview.appspot.com/53094’; implemented by Georg Brandl.) * Conversions between floating-point numbers and strings are now correctly rounded on most platforms. These conversions occur in many different places: *note str(): 330. on floats and complex numbers; the *note float: 187. and *note complex: 189. constructors; numeric formatting; serializing and deserializing floats and complex numbers using the *note marshal: b0, *note pickle: ca. and *note json: a4. modules; parsing of float and imaginary literals in Python code; and *note Decimal: 188.-to-float conversion. Related to this, the *note repr(): 7cc. of a floating-point number `x' now returns a result based on the shortest decimal string that’s guaranteed to round back to `x' under correct rounding (with round-half-to-even rounding mode). Previously it gave a string based on rounding x to 17 decimal digits. The rounding library responsible for this improvement works on Windows and on Unix platforms using the gcc, icc, or suncc compilers. There may be a small number of platforms where correct operation of this code cannot be guaranteed, so the code is not used on such systems. You can find out which code is being used by checking *note sys.float_repr_style: c90, which will be ‘short’ if the new code is in use and ‘legacy’ if it isn’t. Implemented by Eric Smith and Mark Dickinson, using David Gay’s ‘dtoa.c’ library; bpo-7117(3). * Conversions from long integers and regular integers to floating point now round differently, returning the floating-point number closest to the number. This doesn’t matter for small integers that can be converted exactly, but for large numbers that will unavoidably lose precision, Python 2.7 now approximates more closely. For example, Python 2.6 computed the following: >>> n = 295147905179352891391 >>> float(n) 2.9514790517935283e+20 >>> n - long(float(n)) 65535L Python 2.7’s floating-point result is larger, but much closer to the true value: >>> n = 295147905179352891391 >>> float(n) 2.9514790517935289e+20 >>> n - long(float(n)) -1L (Implemented by Mark Dickinson; bpo-3166(4).) Integer division is also more accurate in its rounding behaviours. (Also implemented by Mark Dickinson; bpo-1811(5).) * Implicit coercion for complex numbers has been removed; the interpreter will no longer ever attempt to call a ‘__coerce__()’ method on complex objects. (Removed by Meador Inge and Mark Dickinson; bpo-5211(6).) * The *note str.format(): 4da. method now supports automatic numbering of the replacement fields. This makes using *note str.format(): 4da. more closely resemble using ‘%s’ formatting: >>> '{}:{}:{}'.format(2009, 04, 'Sunday') '2009:4:Sunday' >>> '{}:{}:{day}'.format(2009, 4, day='Sunday') '2009:4:Sunday' The auto-numbering takes the fields from left to right, so the first ‘{...}’ specifier will use the first argument to *note str.format(): 4da, the next specifier will use the next argument, and so on. You can’t mix auto-numbering and explicit numbering – either number all of your specifier fields or none of them – but you can mix auto-numbering and named fields, as in the second example above. (Contributed by Eric Smith; bpo-5237(7).) Complex numbers now correctly support usage with *note format(): 4db, and default to being right-aligned. Specifying a precision or comma-separation applies to both the real and imaginary parts of the number, but a specified field width and alignment is applied to the whole of the resulting ‘1.5+3j’ output. (Contributed by Eric Smith; bpo-1588(8) and bpo-7988(9).) The ‘F’ format code now always formats its output using uppercase characters, so it will now produce ‘INF’ and ‘NAN’. (Contributed by Eric Smith; bpo-3382(10).) A low-level change: the *note object.__format__(): 94e. method now triggers a *note PendingDeprecationWarning: 279. if it’s passed a format string, because the *note __format__(): 94e. method for *note object: 2b0. converts the object to a string representation and formats that. Previously the method silently applied the format string to the string representation, but that could hide mistakes in Python code. If you’re supplying formatting information such as an alignment or precision, presumably you’re expecting the formatting to be applied in some object-specific way. (Fixed by Eric Smith; bpo-7994(11).) * The *note int(): 184. and ‘long()’ types gained a ‘bit_length’ method that returns the number of bits necessary to represent its argument in binary: >>> n = 37 >>> bin(n) '0b100101' >>> n.bit_length() 6 >>> n = 2**123-1 >>> n.bit_length() 123 >>> (n+1).bit_length() 124 (Contributed by Fredrik Johansson and Victor Stinner; bpo-3439(12).) * The *note import: c1d. statement will no longer try an absolute import if a relative import (e.g. ‘from .os import sep’) fails. This fixes a bug, but could possibly break certain ‘import’ statements that were only working by accident. (Fixed by Meador Inge; bpo-7902(13).) * It’s now possible for a subclass of the built-in ‘unicode’ type to override the ‘__unicode__()’ method. (Implemented by Victor Stinner; bpo-1583863(14).) * The *note bytearray: 332. type’s *note translate(): c91. method now accepts ‘None’ as its first argument. (Fixed by Georg Brandl; bpo-4759(15).) * When using ‘@classmethod’ and ‘@staticmethod’ to wrap methods as class or static methods, the wrapper object now exposes the wrapped function as their ‘__func__’ attribute. (Contributed by Amaury Forgeot d’Arc, after a suggestion by George Sakkis; bpo-5982(16).) * When a restricted set of attributes were set using ‘__slots__’, deleting an unset attribute would not raise *note AttributeError: 39b. as you would expect. Fixed by Benjamin Peterson; bpo-7604(17).) * Two new encodings are now supported: “cp720”, used primarily for Arabic text; and “cp858”, a variant of CP 850 that adds the euro symbol. (CP720 contributed by Alexander Belchenko and Amaury Forgeot d’Arc in bpo-1616979(18); CP858 contributed by Tim Hatch in bpo-8016(19).) * The ‘file’ object will now set the ‘filename’ attribute on the *note IOError: 992. exception when trying to open a directory on POSIX platforms (noted by Jan Kaliszewski; bpo-4764(20)), and now explicitly checks for and forbids writing to read-only file objects instead of trusting the C library to catch and report the error (fixed by Stefan Krah; bpo-5677(21)). * The Python tokenizer now translates line endings itself, so the *note compile(): 1b4. built-in function now accepts code using any line-ending convention. Additionally, it no longer requires that the code end in a newline. * Extra parentheses in function definitions are illegal in Python 3.x, meaning that you get a syntax error from ‘def f((x)): pass’. In Python3-warning mode, Python 2.7 will now warn about this odd usage. (Noted by James Lingard; bpo-7362(22).) * It’s now possible to create weak references to old-style class objects. New-style classes were always weak-referenceable. (Fixed by Antoine Pitrou; bpo-8268(23).) * When a module object is garbage-collected, the module’s dictionary is now only cleared if no one else is holding a reference to the dictionary (bpo-7140(24)). * Menu: * Interpreter Changes:: * Optimizations: Optimizations<8>. ---------- Footnotes ---------- (1) https://bugs.python.org/issue2335 (2) https://bugs.python.org/issue2333 (3) https://bugs.python.org/issue7117 (4) https://bugs.python.org/issue3166 (5) https://bugs.python.org/issue1811 (6) https://bugs.python.org/issue5211 (7) https://bugs.python.org/issue5237 (8) https://bugs.python.org/issue1588 (9) https://bugs.python.org/issue7988 (10) https://bugs.python.org/issue3382 (11) https://bugs.python.org/issue7994 (12) https://bugs.python.org/issue3439 (13) https://bugs.python.org/issue7902 (14) https://bugs.python.org/issue1583863 (15) https://bugs.python.org/issue4759 (16) https://bugs.python.org/issue5982 (17) https://bugs.python.org/issue7604 (18) https://bugs.python.org/issue1616979 (19) https://bugs.python.org/issue8016 (20) https://bugs.python.org/issue4764 (21) https://bugs.python.org/issue5677 (22) https://bugs.python.org/issue7362 (23) https://bugs.python.org/issue8268 (24) https://bugs.python.org/issue7140  File: python.info, Node: Interpreter Changes, Next: Optimizations<8>, Up: Other Language Changes<9> 1.10.10.1 Interpreter Changes ............................. A new environment variable, *note PYTHONWARNINGS: 418, allows controlling warnings. It should be set to a string containing warning settings, equivalent to those used with the *note -W: 417. switch, separated by commas. (Contributed by Brian Curtin; bpo-7301(1).) For example, the following setting will print warnings every time they occur, but turn warnings from the ‘Cookie’ module into an error. (The exact syntax for setting an environment variable varies across operating systems and shells.) export PYTHONWARNINGS=all,error:::Cookie:0 ---------- Footnotes ---------- (1) https://bugs.python.org/issue7301  File: python.info, Node: Optimizations<8>, Prev: Interpreter Changes, Up: Other Language Changes<9> 1.10.10.2 Optimizations ....................... Several performance enhancements have been added: * A new opcode was added to perform the initial setup for *note with: 6e9. statements, looking up the *note __enter__(): c95. and *note __exit__(): c96. methods. (Contributed by Benjamin Peterson.) * The garbage collector now performs better for one common usage pattern: when many objects are being allocated without deallocating any of them. This would previously take quadratic time for garbage collection, but now the number of full garbage collections is reduced as the number of objects on the heap grows. The new logic only performs a full garbage collection pass when the middle generation has been collected 10 times and when the number of survivor objects from the middle generation exceeds 10% of the number of objects in the oldest generation. (Suggested by Martin von Löwis and implemented by Antoine Pitrou; bpo-4074(1).) * The garbage collector tries to avoid tracking simple containers which can’t be part of a cycle. In Python 2.7, this is now true for tuples and dicts containing atomic types (such as ints, strings, etc.). Transitively, a dict containing tuples of atomic types won’t be tracked either. This helps reduce the cost of each garbage collection by decreasing the number of objects to be considered and traversed by the collector. (Contributed by Antoine Pitrou; bpo-4688(2).) * Long integers are now stored internally either in base 2**15 or in base 2**30, the base being determined at build time. Previously, they were always stored in base 2**15. Using base 2**30 gives significant performance improvements on 64-bit machines, but benchmark results on 32-bit machines have been mixed. Therefore, the default is to use base 2**30 on 64-bit machines and base 2**15 on 32-bit machines; on Unix, there’s a new configure option ‘--enable-big-digits’ that can be used to override this default. Apart from the performance improvements this change should be invisible to end users, with one exception: for testing and debugging purposes there’s a new structseq ‘sys.long_info’ that provides information about the internal format, giving the number of bits per digit and the size in bytes of the C type used to store each digit: >>> import sys >>> sys.long_info sys.long_info(bits_per_digit=30, sizeof_digit=4) (Contributed by Mark Dickinson; bpo-4258(3).) Another set of changes made long objects a few bytes smaller: 2 bytes smaller on 32-bit systems and 6 bytes on 64-bit. (Contributed by Mark Dickinson; bpo-5260(4).) * The division algorithm for long integers has been made faster by tightening the inner loop, doing shifts instead of multiplications, and fixing an unnecessary extra iteration. Various benchmarks show speedups of between 50% and 150% for long integer divisions and modulo operations. (Contributed by Mark Dickinson; bpo-5512(5).) Bitwise operations are also significantly faster (initial patch by Gregory Smith; bpo-1087418(6)). * The implementation of ‘%’ checks for the left-side operand being a Python string and special-cases it; this results in a 1–3% performance increase for applications that frequently use ‘%’ with strings, such as templating libraries. (Implemented by Collin Winter; bpo-5176(7).) * List comprehensions with an ‘if’ condition are compiled into faster bytecode. (Patch by Antoine Pitrou, back-ported to 2.7 by Jeffrey Yasskin; bpo-4715(8).) * Converting an integer or long integer to a decimal string was made faster by special-casing base 10 instead of using a generalized conversion function that supports arbitrary bases. (Patch by Gawain Bolton; bpo-6713(9).) * The ‘split()’, ‘replace()’, ‘rindex()’, ‘rpartition()’, and ‘rsplit()’ methods of string-like types (strings, Unicode strings, and *note bytearray: 332. objects) now use a fast reverse-search algorithm instead of a character-by-character scan. This is sometimes faster by a factor of 10. (Added by Florent Xicluna; bpo-7462(10) and bpo-7622(11).) * The *note pickle: ca. and ‘cPickle’ modules now automatically intern the strings used for attribute names, reducing memory usage of the objects resulting from unpickling. (Contributed by Jake McGuire; bpo-5084(12).) * The ‘cPickle’ module now special-cases dictionaries, nearly halving the time required to pickle them. (Contributed by Collin Winter; bpo-5670(13).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4074 (2) https://bugs.python.org/issue4688 (3) https://bugs.python.org/issue4258 (4) https://bugs.python.org/issue5260 (5) https://bugs.python.org/issue5512 (6) https://bugs.python.org/issue1087418 (7) https://bugs.python.org/issue5176 (8) https://bugs.python.org/issue4715 (9) https://bugs.python.org/issue6713 (10) https://bugs.python.org/issue7462 (11) https://bugs.python.org/issue7622 (12) https://bugs.python.org/issue5084 (13) https://bugs.python.org/issue5670  File: python.info, Node: New and Improved Modules, Next: Build and C API Changes<8>, Prev: Other Language Changes<9>, Up: What’s New in Python 2 7 1.10.11 New and Improved Modules -------------------------------- As in every release, Python’s standard library received a number of enhancements and bug fixes. Here’s a partial list of the most notable changes, sorted alphabetically by module name. Consult the ‘Misc/NEWS’ file in the source tree for a more complete list of changes, or look through the Subversion logs for all the details. * The *note bdb: f. module’s base debugging class *note Bdb: c98. gained a feature for skipping modules. The constructor now takes an iterable containing glob-style patterns such as ‘django.*’; the debugger will not step into stack frames from a module that matches one of these patterns. (Contributed by Maru Newby after a suggestion by Senthil Kumaran; bpo-5142(1).) * The *note binascii: 10. module now supports the buffer API, so it can be used with *note memoryview: 25c. instances and other similar buffer objects. (Backported from 3.x by Florent Xicluna; bpo-7703(2).) * Updated module: the ‘bsddb’ module has been updated from 4.7.2devel9 to version 4.8.4 of the pybsddb package(3). The new version features better Python 3.x compatibility, various bug fixes, and adds several new BerkeleyDB flags and methods. (Updated by Jesús Cea Avión; bpo-8156(4). The pybsddb changelog can be read at ‘http://hg.jcea.es/pybsddb/file/tip/ChangeLog’.) * The *note bz2: 14. module’s *note BZ2File: 931. now supports the context management protocol, so you can write ‘with bz2.BZ2File(...) as f:’. (Contributed by Hagen Fürstenau; bpo-3860(5).) * New class: the *note Counter: 9da. class in the *note collections: 1e. module is useful for tallying data. *note Counter: 9da. instances behave mostly like dictionaries but return zero for missing keys instead of raising a *note KeyError: 2c7.: >>> from collections import Counter >>> c = Counter() >>> for letter in 'here is a sample of english text': ... c[letter] += 1 ... >>> c Counter({' ': 6, 'e': 5, 's': 3, 'a': 2, 'i': 2, 'h': 2, 'l': 2, 't': 2, 'g': 1, 'f': 1, 'm': 1, 'o': 1, 'n': 1, 'p': 1, 'r': 1, 'x': 1}) >>> c['e'] 5 >>> c['z'] 0 There are three additional *note Counter: 9da. methods. *note most_common(): c99. returns the N most common elements and their counts. *note elements(): c9a. returns an iterator over the contained elements, repeating each element as many times as its count. *note subtract(): b5a. takes an iterable and subtracts one for each element instead of adding; if the argument is a dictionary or another ‘Counter’, the counts are subtracted. >>> c.most_common(5) [(' ', 6), ('e', 5), ('s', 3), ('a', 2), ('i', 2)] >>> c.elements() -> 'a', 'a', ' ', ' ', ' ', ' ', ' ', ' ', 'e', 'e', 'e', 'e', 'e', 'g', 'f', 'i', 'i', 'h', 'h', 'm', 'l', 'l', 'o', 'n', 'p', 's', 's', 's', 'r', 't', 't', 'x' >>> c['e'] 5 >>> c.subtract('very heavy on the letter e') >>> c['e'] # Count is now lower -1 Contributed by Raymond Hettinger; bpo-1696199(6). New class: *note OrderedDict: 1b9. is described in the earlier section *note PEP 372; Adding an Ordered Dictionary to collections: c80. New method: The *note deque: 531. data type now has a *note count(): b5c. method that returns the number of contained elements equal to the supplied argument `x', and a *note reverse(): b5d. method that reverses the elements of the deque in-place. *note deque: 531. also exposes its maximum length as the read-only *note maxlen: c9b. attribute. (Both features added by Raymond Hettinger.) The *note namedtuple: 1b7. class now has an optional `rename' parameter. If `rename' is true, field names that are invalid because they’ve been repeated or aren’t legal Python identifiers will be renamed to legal names that are derived from the field’s position within the list of fields: >>> from collections import namedtuple >>> T = namedtuple('T', ['field1', '$illegal', 'for', 'field2'], rename=True) >>> T._fields ('field1', '_1', '_2', 'field2') (Added by Raymond Hettinger; bpo-1818(7).) Finally, the ‘Mapping’ abstract base class now returns *note NotImplemented: 84c. if a mapping is compared to another type that isn’t a ‘Mapping’. (Fixed by Daniel Stutzbach; bpo-8729(8).) * Constructors for the parsing classes in the ‘ConfigParser’ module now take an `allow_no_value' parameter, defaulting to false; if true, options without values will be allowed. For example: >>> import ConfigParser, StringIO >>> sample_config = """ ... [mysqld] ... user = mysql ... pid-file = /var/run/mysqld/mysqld.pid ... skip-bdb ... """ >>> config = ConfigParser.RawConfigParser(allow_no_value=True) >>> config.readfp(StringIO.StringIO(sample_config)) >>> config.get('mysqld', 'user') 'mysql' >>> print config.get('mysqld', 'skip-bdb') None >>> print config.get('mysqld', 'unknown') Traceback (most recent call last): ... NoOptionError: No option 'unknown' in section: 'mysqld' (Contributed by Mats Kindahl; bpo-7005(9).) * Deprecated function: ‘contextlib.nested()’, which allows handling more than one context manager with a single *note with: 6e9. statement, has been deprecated, because the ‘with’ statement now supports multiple context managers. * The ‘cookielib’ module now ignores cookies that have an invalid version field, one that doesn’t contain an integer value. (Fixed by John J. Lee; bpo-3924(10).) * The *note copy: 26. module’s *note deepcopy(): 3cc. function will now correctly copy bound instance methods. (Implemented by Robert Collins; bpo-1515(11).) * The *note ctypes: 2b. module now always converts ‘None’ to a C ‘NULL’ pointer for arguments declared as pointers. (Changed by Thomas Heller; bpo-4606(12).) The underlying libffi library(13) has been updated to version 3.0.9, containing various fixes for different platforms. (Updated by Matthias Klose; bpo-8142(14).) * New method: the *note datetime: 31. module’s *note timedelta: 195. class gained a *note total_seconds(): c9c. method that returns the number of seconds in the duration. (Contributed by Brian Quinlan; bpo-5788(15).) * New method: the *note Decimal: 188. class gained a *note from_float(): b80. class method that performs an exact conversion of a floating-point number to a *note Decimal: 188. This exact conversion strives for the closest decimal approximation to the floating-point representation’s value; the resulting decimal value will therefore still include the inaccuracy, if any. For example, ‘Decimal.from_float(0.1)’ returns ‘Decimal('0.1000000000000000055511151231257827021181583404541015625')’. (Implemented by Raymond Hettinger; bpo-4796(16).) Comparing instances of *note Decimal: 188. with floating-point numbers now produces sensible results based on the numeric values of the operands. Previously such comparisons would fall back to Python’s default rules for comparing objects, which produced arbitrary results based on their type. Note that you still cannot combine ‘Decimal’ and floating-point in other operations such as addition, since you should be explicitly choosing how to convert between float and *note Decimal: 188. (Fixed by Mark Dickinson; bpo-2531(17).) The constructor for *note Decimal: 188. now accepts floating-point numbers (added by Raymond Hettinger; bpo-8257(18)) and non-European Unicode characters such as Arabic-Indic digits (contributed by Mark Dickinson; bpo-6595(19)). Most of the methods of the *note Context: 9f0. class now accept integers as well as *note Decimal: 188. instances; the only exceptions are the *note canonical(): c9d. and *note is_canonical(): c9e. methods. (Patch by Juan José Conti; bpo-7633(20).) When using *note Decimal: 188. instances with a string’s *note format(): 4da. method, the default alignment was previously left-alignment. This has been changed to right-alignment, which is more sensible for numeric types. (Changed by Mark Dickinson; bpo-6857(21).) Comparisons involving a signaling NaN value (or ‘sNAN’) now signal ‘InvalidOperation’ instead of silently returning a true or false value depending on the comparison operator. Quiet NaN values (or ‘NaN’) are now hashable. (Fixed by Mark Dickinson; bpo-7279(22).) * The *note difflib: 37. module now produces output that is more compatible with modern ‘diff’/‘patch’ tools through one small change, using a tab character instead of spaces as a separator in the header giving the filename. (Fixed by Anatoly Techtonik; bpo-7585(23).) * The Distutils ‘sdist’ command now always regenerates the ‘MANIFEST’ file, since even if the ‘MANIFEST.in’ or ‘setup.py’ files haven’t been modified, the user might have created some new files that should be included. (Fixed by Tarek Ziadé; bpo-8688(24).) * The *note doctest: 67. module’s ‘IGNORE_EXCEPTION_DETAIL’ flag will now ignore the name of the module containing the exception being tested. (Patch by Lennart Regebro; bpo-7490(25).) * The *note email: 69. module’s *note Message: 541. class will now accept a Unicode-valued payload, automatically converting the payload to the encoding specified by ‘output_charset’. (Added by R. David Murray; bpo-1368247(26).) * The *note Fraction: 185. class now accepts a single float or *note Decimal: 188. instance, or two rational numbers, as arguments to its constructor. (Implemented by Mark Dickinson; rationals added in bpo-5812(27), and float/decimal in bpo-8294(28).) Ordering comparisons (‘<’, ‘<=’, ‘>’, ‘>=’) between fractions and complex numbers now raise a *note TypeError: 192. This fixes an oversight, making the *note Fraction: 185. match the other numeric types. * New class: *note FTP_TLS: a03. in the *note ftplib: 84. module provides secure FTP connections using TLS encapsulation of authentication as well as subsequent control and data transfers. (Contributed by Giampaolo Rodola; bpo-2054(29).) The *note storbinary(): c9f. method for binary uploads can now restart uploads thanks to an added `rest' parameter (patch by Pablo Mouzo; bpo-6845(30).) * New class decorator: *note total_ordering(): 84b. in the *note functools: 85. module takes a class that defines an *note __eq__(): 33f. method and one of *note __lt__(): c34, *note __le__(): ca0, *note __gt__(): ca1, or *note __ge__(): ca2, and generates the missing comparison methods. Since the ‘__cmp__()’ method is being deprecated in Python 3.x, this decorator makes it easier to define ordered classes. (Added by Raymond Hettinger; bpo-5479(31).) New function: *note cmp_to_key(): b56. will take an old-style comparison function that expects two arguments and return a new callable that can be used as the `key' parameter to functions such as *note sorted(): 444, *note min(): 809. and *note max(): 80a, etc. The primary intended use is to help with making code compatible with Python 3.x. (Added by Raymond Hettinger.) * New function: the *note gc: 86. module’s *note is_tracked(): ca3. returns true if a given instance is tracked by the garbage collector, false otherwise. (Contributed by Antoine Pitrou; bpo-4688(32).) * The *note gzip: 8c. module’s *note GzipFile: 6dd. now supports the context management protocol, so you can write ‘with gzip.GzipFile(...) as f:’ (contributed by Hagen Fürstenau; bpo-3860(33)), and it now implements the *note io.BufferedIOBase: 588. ABC, so you can wrap it with *note io.BufferedReader: b8a. for faster processing (contributed by Nir Aides; bpo-7471(34)). It’s also now possible to override the modification time recorded in a gzipped file by providing an optional timestamp to the constructor. (Contributed by Jacques Frechet; bpo-4272(35).) Files in gzip format can be padded with trailing zero bytes; the *note gzip: 8c. module will now consume these trailing bytes. (Fixed by Tadek Pietraszek and Brian Curtin; bpo-2846(36).) * New attribute: the *note hashlib: 8d. module now has an ‘algorithms’ attribute containing a tuple naming the supported algorithms. In Python 2.7, ‘hashlib.algorithms’ contains ‘('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')’. (Contributed by Carl Chenet; bpo-7418(37).) * The default ‘HTTPResponse’ class used by the ‘httplib’ module now supports buffering, resulting in much faster reading of HTTP responses. (Contributed by Kristján Valur Jónsson; bpo-4879(38).) The ‘HTTPConnection’ and ‘HTTPSConnection’ classes now support a `source_address' parameter, a ‘(host, port)’ 2-tuple giving the source address that will be used for the connection. (Contributed by Eldon Ziegler; bpo-3972(39).) * The ‘ihooks’ module now supports relative imports. Note that ‘ihooks’ is an older module for customizing imports, superseded by the ‘imputil’ module added in Python 2.0. (Relative import support added by Neil Schemenauer.) * The *note imaplib: 98. module now supports IPv6 addresses. (Contributed by Derek Morr; bpo-1655(40).) * New function: the *note inspect: a0. module’s *note getcallargs(): 7b6. takes a callable and its positional and keyword arguments, and figures out which of the callable’s parameters will receive each argument, returning a dictionary mapping argument names to their values. For example: >>> from inspect import getcallargs >>> def f(a, b=1, *pos, **named): ... pass >>> getcallargs(f, 1, 2, 3) {'a': 1, 'b': 2, 'pos': (3,), 'named': {}} >>> getcallargs(f, a=2, x=4) {'a': 2, 'b': 1, 'pos': (), 'named': {'x': 4}} >>> getcallargs(f) Traceback (most recent call last): ... TypeError: f() takes at least 1 argument (0 given) Contributed by George Sakkis; bpo-3135(41). * Updated module: The *note io: a1. library has been upgraded to the version shipped with Python 3.1. For 3.1, the I/O library was entirely rewritten in C and is 2 to 20 times faster depending on the task being performed. The original Python version was renamed to the ‘_pyio’ module. One minor resulting change: the *note io.TextIOBase: c39. class now has an ‘errors’ attribute giving the error setting used for encoding and decoding errors (one of ‘'strict'’, ‘'replace'’, ‘'ignore'’). The *note io.FileIO: ca4. class now raises an *note OSError: 1d3. when passed an invalid file descriptor. (Implemented by Benjamin Peterson; bpo-4991(42).) The *note truncate(): ca5. method now preserves the file position; previously it would change the file position to the end of the new file. (Fixed by Pascal Chambon; bpo-6939(43).) * New function: ‘itertools.compress(data, selectors)’ takes two iterators. Elements of `data' are returned if the corresponding value in `selectors' is true: itertools.compress('ABCDEF', [1,0,1,0,1,1]) => A, C, E, F New function: ‘itertools.combinations_with_replacement(iter, r)’ returns all the possible `r'-length combinations of elements from the iterable `iter'. Unlike *note combinations(): ca6, individual elements can be repeated in the generated combinations: itertools.combinations_with_replacement('abc', 2) => ('a', 'a'), ('a', 'b'), ('a', 'c'), ('b', 'b'), ('b', 'c'), ('c', 'c') Note that elements are treated as unique depending on their position in the input, not their actual values. The *note itertools.count(): c1b. function now has a `step' argument that allows incrementing by values other than 1. *note count(): c1b. also now allows keyword arguments, and using non-integer values such as floats or *note Decimal: 188. instances. (Implemented by Raymond Hettinger; bpo-5032(44).) *note itertools.combinations(): ca6. and *note itertools.product(): ca7. previously raised *note ValueError: 1fb. for values of `r' larger than the input iterable. This was deemed a specification error, so they now return an empty iterator. (Fixed by Raymond Hettinger; bpo-4816(45).) * Updated module: The *note json: a4. module was upgraded to version 2.0.9 of the simplejson package, which includes a C extension that makes encoding and decoding faster. (Contributed by Bob Ippolito; bpo-4136(46).) To support the new *note collections.OrderedDict: 1b9. type, *note json.load(): 55f. now has an optional `object_pairs_hook' parameter that will be called with any object literal that decodes to a list of pairs. (Contributed by Raymond Hettinger; bpo-5381(47).) * The *note mailbox: ae. module’s *note Maildir: ca8. class now records the timestamp on the directories it reads, and only re-reads them if the modification time has subsequently changed. This improves performance by avoiding unneeded directory scans. (Fixed by A.M. Kuchling and Antoine Pitrou; bpo-1607951(48), bpo-6896(49).) * New functions: the *note math: b1. module gained *note erf(): 452. and *note erfc(): 453. for the error function and the complementary error function, *note expm1(): b68. which computes ‘e**x - 1’ with more precision than using *note exp(): ca9. and subtracting 1, *note gamma(): b69. for the Gamma function, and *note lgamma(): b6a. for the natural log of the Gamma function. (Contributed by Mark Dickinson and nirinA raseliarison; bpo-3366(50).) * The *note multiprocessing: b7. module’s ‘Manager*’ classes can now be passed a callable that will be called whenever a subprocess is started, along with a set of arguments that will be passed to the callable. (Contributed by lekma; bpo-5585(51).) The ‘Pool’ class, which controls a pool of worker processes, now has an optional `maxtasksperchild' parameter. Worker processes will perform the specified number of tasks and then exit, causing the ‘Pool’ to start a new worker. This is useful if tasks may leak memory or other resources, or if some tasks will cause the worker to become very large. (Contributed by Charles Cazabon; bpo-6963(52).) * The *note nntplib: c0. module now supports IPv6 addresses. (Contributed by Derek Morr; bpo-1664(53).) * New functions: the *note os: c4. module wraps the following POSIX system calls: *note getresgid(): caa. and *note getresuid(): cab, which return the real, effective, and saved GIDs and UIDs; *note setresgid(): cac. and *note setresuid(): cad, which set real, effective, and saved GIDs and UIDs to new values; *note initgroups(): cae, which initialize the group access list for the current process. (GID/UID functions contributed by Travis H.; bpo-6508(54). Support for initgroups added by Jean-Paul Calderone; bpo-7333(55).) The *note os.fork(): 961. function now re-initializes the import lock in the child process; this fixes problems on Solaris when *note fork(): 961. is called from a thread. (Fixed by Zsolt Cserna; bpo-7242(56).) * In the *note os.path: c5. module, the *note normpath(): caf. and *note abspath(): cb0. functions now preserve Unicode; if their input path is a Unicode string, the return value is also a Unicode string. (*note normpath(): caf. fixed by Matt Giuca in bpo-5827(57); *note abspath(): cb0. fixed by Ezio Melotti in bpo-3426(58).) * The *note pydoc: d9. module now has help for the various symbols that Python uses. You can now do ‘help('<<')’ or ‘help('@')’, for example. (Contributed by David Laban; bpo-4739(59).) * The *note re: dd. module’s *note split(): 3ca, *note sub(): 47b, and *note subn(): 734. now accept an optional `flags' argument, for consistency with the other functions in the module. (Added by Gregory P. Smith.) * New function: *note run_path(): cb1. in the *note runpy: e2. module will execute the code at a provided `path' argument. `path' can be the path of a Python source file (‘example.py’), a compiled bytecode file (‘example.pyc’), a directory (‘./package/’), or a zip archive (‘example.zip’). If a directory or zip path is provided, it will be added to the front of ‘sys.path’ and the module *note __main__: 1. will be imported. It’s expected that the directory or zip contains a ‘__main__.py’; if it doesn’t, some other ‘__main__.py’ might be imported from a location later in ‘sys.path’. This makes more of the machinery of *note runpy: e2. available to scripts that want to mimic the way Python’s command line processes an explicit path name. (Added by Nick Coghlan; bpo-6816(60).) * New function: in the *note shutil: e9. module, *note make_archive(): 21b. takes a filename, archive type (zip or tar-format), and a directory path, and creates an archive containing the directory’s contents. (Added by Tarek Ziadé.) *note shutil: e9.’s *note copyfile(): 258. and *note copytree(): 21a. functions now raise a ‘SpecialFileError’ exception when asked to copy a named pipe. Previously the code would treat named pipes like a regular file by opening them for reading, and this would block indefinitely. (Fixed by Antoine Pitrou; bpo-3002(61).) * The *note signal: ea. module no longer re-installs the signal handler unless this is truly necessary, which fixes a bug that could make it impossible to catch the EINTR signal robustly. (Fixed by Charles-Francois Natali; bpo-8354(62).) * New functions: in the *note site: eb. module, three new functions return various site- and user-specific paths. *note getsitepackages(): bd3. returns a list containing all global site-packages directories, *note getusersitepackages(): bd5. returns the path of the user’s site-packages directory, and *note getuserbase(): bd4. returns the value of the ‘USER_BASE’ environment variable, giving the path to a directory that can be used to store data. (Contributed by Tarek Ziadé; bpo-6693(63).) The *note site: eb. module now reports exceptions occurring when the ‘sitecustomize’ module is imported, and will no longer catch and swallow the *note KeyboardInterrupt: 197. exception. (Fixed by Victor Stinner; bpo-3137(64).) * The *note create_connection(): b9e. function gained a `source_address' parameter, a ‘(host, port)’ 2-tuple giving the source address that will be used for the connection. (Contributed by Eldon Ziegler; bpo-3972(65).) The *note recv_into(): cb2. and *note recvfrom_into(): cb3. methods will now write into objects that support the buffer API, most usefully the *note bytearray: 332. and *note memoryview: 25c. objects. (Implemented by Antoine Pitrou; bpo-8104(66).) * The ‘SocketServer’ module’s ‘TCPServer’ class now supports socket timeouts and disabling the Nagle algorithm. The ‘disable_nagle_algorithm’ class attribute defaults to ‘False’; if overridden to be true, new request connections will have the TCP_NODELAY option set to prevent buffering many small sends into a single TCP packet. The ‘timeout’ class attribute can hold a timeout in seconds that will be applied to the request socket; if no request is received within that time, ‘handle_timeout()’ will be called and ‘handle_request()’ will return. (Contributed by Kristján Valur Jónsson; bpo-6192(67) and bpo-6267(68).) * Updated module: the *note sqlite3: f2. module has been updated to version 2.6.0 of the pysqlite package(69). Version 2.6.0 includes a number of bugfixes, and adds the ability to load SQLite extensions from shared libraries. Call the ‘enable_load_extension(True)’ method to enable extensions, and then call *note load_extension(): b9a. to load a particular shared library. (Updated by Gerhard Häring.) * The *note ssl: f3. module’s *note SSLSocket: 3e2. objects now support the buffer API, which fixed a test suite failure (fix by Antoine Pitrou; bpo-7133(70)) and automatically set OpenSSL’s ‘SSL_MODE_AUTO_RETRY’, which will prevent an error code being returned from ‘recv()’ operations that trigger an SSL renegotiation (fix by Antoine Pitrou; bpo-8222(71)). The *note ssl.wrap_socket(): 46f. constructor function now takes a `ciphers' argument that’s a string listing the encryption algorithms to be allowed; the format of the string is described in the OpenSSL documentation(72). (Added by Antoine Pitrou; bpo-8322(73).) Another change makes the extension load all of OpenSSL’s ciphers and digest algorithms so that they’re all available. Some SSL certificates couldn’t be verified, reporting an “unknown algorithm” error. (Reported by Beda Kosata, and fixed by Antoine Pitrou; bpo-8484(74).) The version of OpenSSL being used is now available as the module attributes *note ssl.OPENSSL_VERSION: ba1. (a string), *note ssl.OPENSSL_VERSION_INFO: ba2. (a 5-tuple), and *note ssl.OPENSSL_VERSION_NUMBER: ba3. (an integer). (Added by Antoine Pitrou; bpo-8321(75).) * The *note struct: f8. module will no longer silently ignore overflow errors when a value is too large for a particular integer format code (one of ‘bBhHiIlLqQ’); it now always raises a *note struct.error: cb4. exception. (Changed by Mark Dickinson; bpo-1523(76).) The *note pack(): c0b. function will also attempt to use *note __index__(): 18a. to convert and pack non-integers before trying the *note __int__(): 18b. method or reporting an error. (Changed by Mark Dickinson; bpo-8300(77).) * New function: the *note subprocess: f9. module’s *note check_output(): 8db. runs a command with a specified set of arguments and returns the command’s output as a string when the command runs without error, or raises a *note CalledProcessError: cb5. exception otherwise. >>> subprocess.check_output(['df', '-h', '.']) 'Filesystem Size Used Avail Capacity Mounted on\n /dev/disk0s2 52G 49G 3.0G 94% /\n' >>> subprocess.check_output(['df', '-h', '/bogus']) ... subprocess.CalledProcessError: Command '['df', '-h', '/bogus']' returned non-zero exit status 1 (Contributed by Gregory P. Smith.) The *note subprocess: f9. module will now retry its internal system calls on receiving an ‘EINTR’ signal. (Reported by several people; final patch by Gregory P. Smith in bpo-1068268(78).) * New function: *note is_declared_global(): cb6. in the *note symtable: fc. module returns true for variables that are explicitly declared to be global, false for ones that are implicitly global. (Contributed by Jeremy Hylton.) * The *note syslog: ff. module will now use the value of ‘sys.argv[0]’ as the identifier instead of the previous default value of ‘'python'’. (Changed by Sean Reifschneider; bpo-8451(79).) * The ‘sys.version_info’ value is now a named tuple, with attributes named ‘major’, ‘minor’, ‘micro’, ‘releaselevel’, and ‘serial’. (Contributed by Ross Light; bpo-4285(80).) *note sys.getwindowsversion(): 595. also returns a named tuple, with attributes named ‘major’, ‘minor’, ‘build’, *note platform: ce, ‘service_pack’, ‘service_pack_major’, ‘service_pack_minor’, ‘suite_mask’, and ‘product_type’. (Contributed by Brian Curtin; bpo-7766(81).) * The *note tarfile: 101. module’s default error handling has changed, to no longer suppress fatal errors. The default error level was previously 0, which meant that errors would only result in a message being written to the debug log, but because the debug log is not activated by default, these errors go unnoticed. The default error level is now 1, which raises an exception if there’s an error. (Changed by Lars Gustäbel; bpo-7357(82).) *note tarfile: 101. now supports filtering the *note TarInfo: b8d. objects being added to a tar file. When you call *note add(): 47c, you may supply an optional `filter' argument that’s a callable. The `filter' callable will be passed the *note TarInfo: b8d. for every file being added, and can modify and return it. If the callable returns ‘None’, the file will be excluded from the resulting archive. This is more powerful than the existing `exclude' argument, which has therefore been deprecated. (Added by Lars Gustäbel; bpo-6856(83).) The *note TarFile: b8c. class also now supports the context management protocol. (Added by Lars Gustäbel; bpo-7232(84).) * The *note wait(): cb7. method of the *note threading.Event: aad. class now returns the internal flag on exit. This means the method will usually return true because *note wait(): cb7. is supposed to block until the internal flag becomes true. The return value will only be false if a timeout was provided and the operation timed out. (Contributed by Tim Lesher; bpo-1674032(85).) * The Unicode database provided by the *note unicodedata: 11a. module is now used internally to determine which characters are numeric, whitespace, or represent line breaks. The database also includes information from the ‘Unihan.txt’ data file (patch by Anders Chrigström and Amaury Forgeot d’Arc; bpo-1571184(86)) and has been updated to version 5.2.0 (updated by Florent Xicluna; bpo-8024(87)). * The ‘urlparse’ module’s ‘urlsplit()’ now handles unknown URL schemes in a fashion compliant with RFC 3986(88): if the URL is of the form ‘"://..."’, the text before the ‘://’ is treated as the scheme, even if it’s a made-up scheme that the module doesn’t know about. This change may break code that worked around the old behaviour. For example, Python 2.6.4 or 2.5 will return the following: >>> import urlparse >>> urlparse.urlsplit('invented://host/filename?query') ('invented', '', '//host/filename?query', '', '') Python 2.7 (and Python 2.6.5) will return: >>> import urlparse >>> urlparse.urlsplit('invented://host/filename?query') ('invented', 'host', '/filename?query', '', '') (Python 2.7 actually produces slightly different output, since it returns a named tuple instead of a standard tuple.) The ‘urlparse’ module also supports IPv6 literal addresses as defined by RFC 2732(89) (contributed by Senthil Kumaran; bpo-2987(90)). >>> urlparse.urlparse('http://[1080::8:800:200C:417A]/foo') ParseResult(scheme='http', netloc='[1080::8:800:200C:417A]', path='/foo', params='', query='', fragment='') * New class: the *note WeakSet: cb8. class in the *note weakref: 128. module is a set that only holds weak references to its elements; elements will be removed once there are no references pointing to them. (Originally implemented in Python 3.x by Raymond Hettinger, and backported to 2.7 by Michael Foord.) * The ElementTree library, ‘xml.etree’, no longer escapes ampersands and angle brackets when outputting an XML processing instruction (which looks like ‘’) or comment (which looks like ‘’). (Patch by Neil Muller; bpo-2746(91).) * The XML-RPC client and server, provided by the ‘xmlrpclib’ and ‘SimpleXMLRPCServer’ modules, have improved performance by supporting HTTP/1.1 keep-alive and by optionally using gzip encoding to compress the XML being exchanged. The gzip compression is controlled by the ‘encode_threshold’ attribute of ‘SimpleXMLRPCRequestHandler’, which contains a size in bytes; responses larger than this will be compressed. (Contributed by Kristján Valur Jónsson; bpo-6267(92).) * The *note zipfile: 142. module’s *note ZipFile: 41f. now supports the context management protocol, so you can write ‘with zipfile.ZipFile(...) as f:’. (Contributed by Brian Curtin; bpo-5511(93).) *note zipfile: 142. now also supports archiving empty directories and extracts them correctly. (Fixed by Kuba Wieczorek; bpo-4710(94).) Reading files out of an archive is faster, and interleaving *note read(): cb9. and ‘readline()’ now works correctly. (Contributed by Nir Aides; bpo-7610(95).) The *note is_zipfile(): cba. function now accepts a file object, in addition to the path names accepted in earlier versions. (Contributed by Gabriel Genellina; bpo-4756(96).) The *note writestr(): cbb. method now has an optional `compress_type' parameter that lets you override the default compression method specified in the *note ZipFile: 41f. constructor. (Contributed by Ronald Oussoren; bpo-6003(97).) * Menu: * New module; importlib: New module importlib. * New module; sysconfig: New module sysconfig. * ttk; Themed Widgets for Tk: ttk Themed Widgets for Tk. * Updated module; unittest: Updated module unittest. * Updated module; ElementTree 1.3: Updated module ElementTree 1 3. ---------- Footnotes ---------- (1) https://bugs.python.org/issue5142 (2) https://bugs.python.org/issue7703 (3) https://www.jcea.es/programacion/pybsddb.htm (4) https://bugs.python.org/issue8156 (5) https://bugs.python.org/issue3860 (6) https://bugs.python.org/issue1696199 (7) https://bugs.python.org/issue1818 (8) https://bugs.python.org/issue8729 (9) https://bugs.python.org/issue7005 (10) https://bugs.python.org/issue3924 (11) https://bugs.python.org/issue1515 (12) https://bugs.python.org/issue4606 (13) https://sourceware.org/libffi/ (14) https://bugs.python.org/issue8142 (15) https://bugs.python.org/issue5788 (16) https://bugs.python.org/issue4796 (17) https://bugs.python.org/issue2531 (18) https://bugs.python.org/issue8257 (19) https://bugs.python.org/issue6595 (20) https://bugs.python.org/issue7633 (21) https://bugs.python.org/issue6857 (22) https://bugs.python.org/issue7279 (23) https://bugs.python.org/issue7585 (24) https://bugs.python.org/issue8688 (25) https://bugs.python.org/issue7490 (26) https://bugs.python.org/issue1368247 (27) https://bugs.python.org/issue5812 (28) https://bugs.python.org/issue8294 (29) https://bugs.python.org/issue2054 (30) https://bugs.python.org/issue6845 (31) https://bugs.python.org/issue5479 (32) https://bugs.python.org/issue4688 (33) https://bugs.python.org/issue3860 (34) https://bugs.python.org/issue7471 (35) https://bugs.python.org/issue4272 (36) https://bugs.python.org/issue2846 (37) https://bugs.python.org/issue7418 (38) https://bugs.python.org/issue4879 (39) https://bugs.python.org/issue3972 (40) https://bugs.python.org/issue1655 (41) https://bugs.python.org/issue3135 (42) https://bugs.python.org/issue4991 (43) https://bugs.python.org/issue6939 (44) https://bugs.python.org/issue5032 (45) https://bugs.python.org/issue4816 (46) https://bugs.python.org/issue4136 (47) https://bugs.python.org/issue5381 (48) https://bugs.python.org/issue1607951 (49) https://bugs.python.org/issue6896 (50) https://bugs.python.org/issue3366 (51) https://bugs.python.org/issue5585 (52) https://bugs.python.org/issue6963 (53) https://bugs.python.org/issue1664 (54) https://bugs.python.org/issue6508 (55) https://bugs.python.org/issue7333 (56) https://bugs.python.org/issue7242 (57) https://bugs.python.org/issue5827 (58) https://bugs.python.org/issue3426 (59) https://bugs.python.org/issue4739 (60) https://bugs.python.org/issue6816 (61) https://bugs.python.org/issue3002 (62) https://bugs.python.org/issue8354 (63) https://bugs.python.org/issue6693 (64) https://bugs.python.org/issue3137 (65) https://bugs.python.org/issue3972 (66) https://bugs.python.org/issue8104 (67) https://bugs.python.org/issue6192 (68) https://bugs.python.org/issue6267 (69) https://github.com/ghaering/pysqlite (70) https://bugs.python.org/issue7133 (71) https://bugs.python.org/issue8222 (72) https://www.openssl.org/docs/manmaster/man1/ciphers.html#CIPHER-LIST-FORMAT (73) https://bugs.python.org/issue8322 (74) https://bugs.python.org/issue8484 (75) https://bugs.python.org/issue8321 (76) https://bugs.python.org/issue1523 (77) https://bugs.python.org/issue8300 (78) https://bugs.python.org/issue1068268 (79) https://bugs.python.org/issue8451 (80) https://bugs.python.org/issue4285 (81) https://bugs.python.org/issue7766 (82) https://bugs.python.org/issue7357 (83) https://bugs.python.org/issue6856 (84) https://bugs.python.org/issue7232 (85) https://bugs.python.org/issue1674032 (86) https://bugs.python.org/issue1571184 (87) https://bugs.python.org/issue8024 (88) https://tools.ietf.org/html/rfc3986.html (89) https://tools.ietf.org/html/rfc2732.html (90) https://bugs.python.org/issue2987 (91) https://bugs.python.org/issue2746 (92) https://bugs.python.org/issue6267 (93) https://bugs.python.org/issue5511 (94) https://bugs.python.org/issue4710 (95) https://bugs.python.org/issue7610 (96) https://bugs.python.org/issue4756 (97) https://bugs.python.org/issue6003  File: python.info, Node: New module importlib, Next: New module sysconfig, Up: New and Improved Modules 1.10.11.1 New module: importlib ............................... Python 3.1 includes the *note importlib: 9b. package, a re-implementation of the logic underlying Python’s *note import: c1d. statement. *note importlib: 9b. is useful for implementors of Python interpreters and to users who wish to write new importers that can participate in the import process. Python 2.7 doesn’t contain the complete *note importlib: 9b. package, but instead has a tiny subset that contains a single function, *note import_module(): b13. ‘import_module(name, package=None)’ imports a module. `name' is a string containing the module or package’s name. It’s possible to do relative imports by providing a string that begins with a ‘.’ character, such as ‘..utils.errors’. For relative imports, the `package' argument must be provided and is the name of the package that will be used as the anchor for the relative import. *note import_module(): b13. both inserts the imported module into ‘sys.modules’ and returns the module object. Here are some examples: >>> from importlib import import_module >>> anydbm = import_module('anydbm') # Standard absolute import >>> anydbm >>> # Relative import >>> file_util = import_module('..file_util', 'distutils.command') >>> file_util *note importlib: 9b. was implemented by Brett Cannon and introduced in Python 3.1.  File: python.info, Node: New module sysconfig, Next: ttk Themed Widgets for Tk, Prev: New module importlib, Up: New and Improved Modules 1.10.11.2 New module: sysconfig ............................... The *note sysconfig: fe. module has been pulled out of the Distutils package, becoming a new top-level module in its own right. *note sysconfig: fe. provides functions for getting information about Python’s build process: compiler switches, installation paths, the platform name, and whether Python is running from its source directory. Some of the functions in the module are: * *note get_config_var(): 964. returns variables from Python’s Makefile and the ‘pyconfig.h’ file. * *note get_config_vars(): 965. returns a dictionary containing all of the configuration variables. * *note get_path(): cbe. returns the configured path for a particular type of module: the standard library, site-specific modules, platform-specific modules, etc. * *note is_python_build(): cbf. returns true if you’re running a binary from a Python source tree, and false otherwise. Consult the *note sysconfig: fe. documentation for more details and for a complete list of functions. The Distutils package and *note sysconfig: fe. are now maintained by Tarek Ziadé, who has also started a Distutils2 package (source repository at ‘https://hg.python.org/distutils2/’) for developing a next-generation version of Distutils.  File: python.info, Node: ttk Themed Widgets for Tk, Next: Updated module unittest, Prev: New module sysconfig, Up: New and Improved Modules 1.10.11.3 ttk: Themed Widgets for Tk .................................... Tcl/Tk 8.5 includes a set of themed widgets that re-implement basic Tk widgets but have a more customizable appearance and can therefore more closely resemble the native platform’s widgets. This widget set was originally called Tile, but was renamed to Ttk (for “themed Tk”) on being added to Tcl/Tck release 8.5. To learn more, read the ‘ttk’ module documentation. You may also wish to read the Tcl/Tk manual page describing the Ttk theme engine, available at ‘https://www.tcl.tk/man/tcl8.5/TkCmd/ttk_intro.htm’. Some screenshots of the Python/Ttk code in use are at ‘https://code.google.com/archive/p/python-ttk/wikis/Screenshots.wiki’. The ‘ttk’ module was written by Guilherme Polo and added in bpo-2983(1). An alternate version called ‘Tile.py’, written by Martin Franklin and maintained by Kevin Walzer, was proposed for inclusion in bpo-2618(2), but the authors argued that Guilherme Polo’s work was more comprehensive. ---------- Footnotes ---------- (1) https://bugs.python.org/issue2983 (2) https://bugs.python.org/issue2618  File: python.info, Node: Updated module unittest, Next: Updated module ElementTree 1 3, Prev: ttk Themed Widgets for Tk, Up: New and Improved Modules 1.10.11.4 Updated module: unittest .................................. The *note unittest: 11b. module was greatly enhanced; many new features were added. Most of these features were implemented by Michael Foord, unless otherwise noted. The enhanced version of the module is downloadable separately for use with Python versions 2.4 to 2.6, packaged as the ‘unittest2’ package, from ‘https://pypi.org/project/unittest2’. When used from the command line, the module can automatically discover tests. It’s not as fancy as py.test(1) or nose(2), but provides a simple way to run tests kept within a set of package directories. For example, the following command will search the ‘test/’ subdirectory for any importable test files named ‘test*.py’: python -m unittest discover -s test Consult the *note unittest: 11b. module documentation for more details. (Developed in bpo-6001(3).) The *note main(): 902. function supports some other new options: * *note -b: cc3. or ‘--buffer’ will buffer the standard output and standard error streams during each test. If the test passes, any resulting output will be discarded; on failure, the buffered output will be displayed. * *note -c: cc4. or ‘--catch’ will cause the control-C interrupt to be handled more gracefully. Instead of interrupting the test process immediately, the currently running test will be completed and then the partial results up to the interruption will be reported. If you’re impatient, a second press of control-C will cause an immediate interruption. This control-C handler tries to avoid causing problems when the code being tested or the tests being run have defined a signal handler of their own, by noticing that a signal handler was already set and calling it. If this doesn’t work for you, there’s a *note removeHandler(): cc5. decorator that can be used to mark tests that should have the control-C handling disabled. * *note -f: cc6. or ‘--failfast’ makes test execution stop immediately when a test fails instead of continuing to execute further tests. (Suggested by Cliff Dyer and implemented by Michael Foord; bpo-8074(4).) The progress messages now show ‘x’ for expected failures and ‘u’ for unexpected successes when run in verbose mode. (Contributed by Benjamin Peterson.) Test cases can raise the *note SkipTest: 903. exception to skip a test (bpo-1034053(5)). The error messages for *note assertEqual(): bb5, *note assertTrue(): bb4, and *note assertFalse(): cc7. failures now provide more information. If you set the *note longMessage: cc8. attribute of your *note TestCase: 8ff. classes to true, both the standard error message and any additional message you provide will be printed for failures. (Added by Michael Foord; bpo-5663(6).) The *note assertRaises(): aba. method now returns a context handler when called without providing a callable object to run. For example, you can write this: with self.assertRaises(KeyError): {}['foo'] (Implemented by Antoine Pitrou; bpo-4444(7).) Module- and class-level setup and teardown fixtures are now supported. Modules can contain ‘setUpModule()’ and ‘tearDownModule()’ functions. Classes can have *note setUpClass(): 24c. and *note tearDownClass(): cc9. methods that must be defined as class methods (using ‘@classmethod’ or equivalent). These functions and methods are invoked when the test runner switches to a test case in a different module or class. The methods *note addCleanup(): 2a2. and *note doCleanups(): cca. were added. *note addCleanup(): 2a2. lets you add cleanup functions that will be called unconditionally (after *note setUp(): ccb. if *note setUp(): ccb. fails, otherwise after *note tearDown(): ccc.). This allows for much simpler resource allocation and deallocation during tests (bpo-5679(8)). A number of new methods were added that provide more specialized tests. Many of these methods were written by Google engineers for use in their test suites; Gregory P. Smith, Michael Foord, and GvR worked on merging them into Python’s version of *note unittest: 11b. * *note assertIsNone(): ccd. and *note assertIsNotNone(): cce. take one expression and verify that the result is or is not ‘None’. * *note assertIs(): ccf. and *note assertIsNot(): cd0. take two values and check whether the two values evaluate to the same object or not. (Added by Michael Foord; bpo-2578(9).) * *note assertIsInstance(): cd1. and *note assertNotIsInstance(): cd2. check whether the resulting object is an instance of a particular class, or of one of a tuple of classes. (Added by Georg Brandl; bpo-7031(10).) * *note assertGreater(): cd3, *note assertGreaterEqual(): cd4, *note assertLess(): cd5, and *note assertLessEqual(): cd6. compare two quantities. * *note assertMultiLineEqual(): cd7. compares two strings, and if they’re not equal, displays a helpful comparison that highlights the differences in the two strings. This comparison is now used by default when Unicode strings are compared with *note assertEqual(): bb5. * ‘assertRegexpMatches()’ and ‘assertNotRegexpMatches()’ checks whether the first argument is a string matching or not matching the regular expression provided as the second argument (bpo-8038(11)). * ‘assertRaisesRegexp()’ checks whether a particular exception is raised, and then also checks that the string representation of the exception matches the provided regular expression. * *note assertIn(): cd8. and *note assertNotIn(): cd9. tests whether `first' is or is not in `second'. * ‘assertItemsEqual()’ tests whether two provided sequences contain the same elements. * *note assertSetEqual(): cda. compares whether two sets are equal, and only reports the differences between the sets in case of error. * Similarly, *note assertListEqual(): cdb. and *note assertTupleEqual(): cdc. compare the specified types and explain any differences without necessarily printing their full values; these methods are now used by default when comparing lists and tuples using *note assertEqual(): bb5. More generally, *note assertSequenceEqual(): cdd. compares two sequences and can optionally check whether both sequences are of a particular type. * *note assertDictEqual(): cde. compares two dictionaries and reports the differences; it’s now used by default when you compare two dictionaries using *note assertEqual(): bb5. ‘assertDictContainsSubset()’ checks whether all of the key/value pairs in `first' are found in `second'. * *note assertAlmostEqual(): bb7. and *note assertNotAlmostEqual(): bb8. test whether `first' and `second' are approximately equal. This method can either round their difference to an optionally-specified number of `places' (the default is 7) and compare it to zero, or require the difference to be smaller than a supplied `delta' value. * *note loadTestsFromName(): cdf. properly honors the *note suiteClass: ce0. attribute of the *note TestLoader: 782. (Fixed by Mark Roddy; bpo-6866(12).) * A new hook lets you extend the *note assertEqual(): bb5. method to handle new data types. The *note addTypeEqualityFunc(): ce1. method takes a type object and a function. The function will be used when both of the objects being compared are of the specified type. This function should compare the two objects and raise an exception if they don’t match; it’s a good idea for the function to provide additional information about why the two objects aren’t matching, much as the new sequence comparison methods do. *note unittest.main(): 902. now takes an optional ‘exit’ argument. If false, *note main(): 902. doesn’t call *note sys.exit(): ce2, allowing *note main(): 902. to be used from the interactive interpreter. (Contributed by J. Pablo Fernández; bpo-3379(13).) *note TestResult: abf. has new *note startTestRun(): ce3. and *note stopTestRun(): ce4. methods that are called immediately before and after a test run. (Contributed by Robert Collins; bpo-5728(14).) With all these changes, the ‘unittest.py’ was becoming awkwardly large, so the module was turned into a package and the code split into several files (by Benjamin Peterson). This doesn’t affect how the module is imported or used. See also ........ ‘http://www.voidspace.org.uk/python/articles/unittest2.shtml’ Describes the new features, how to use them, and the rationale for various design decisions. (By Michael Foord.) ---------- Footnotes ---------- (1) http://pytest.org (2) https://nose.readthedocs.io/ (3) https://bugs.python.org/issue6001 (4) https://bugs.python.org/issue8074 (5) https://bugs.python.org/issue1034053 (6) https://bugs.python.org/issue5663 (7) https://bugs.python.org/issue4444 (8) https://bugs.python.org/issue5679 (9) https://bugs.python.org/issue2578 (10) https://bugs.python.org/issue7031 (11) https://bugs.python.org/issue8038 (12) https://bugs.python.org/issue6866 (13) https://bugs.python.org/issue3379 (14) https://bugs.python.org/issue5728  File: python.info, Node: Updated module ElementTree 1 3, Prev: Updated module unittest, Up: New and Improved Modules 1.10.11.5 Updated module: ElementTree 1.3 ......................................... The version of the ElementTree library included with Python was updated to version 1.3. Some of the new features are: * The various parsing functions now take a `parser' keyword argument giving an *note XMLParser: 252. instance that will be used. This makes it possible to override the file’s internal encoding: p = ET.XMLParser(encoding='utf-8') t = ET.XML("""""", parser=p) Errors in parsing XML now raise a ‘ParseError’ exception, whose instances have a ‘position’ attribute containing a (`line', `column') tuple giving the location of the problem. * ElementTree’s code for converting trees to a string has been significantly reworked, making it roughly twice as fast in many cases. The *note ElementTree.write(): 918. and ‘Element.write()’ methods now have a `method' parameter that can be “xml” (the default), “html”, or “text”. HTML mode will output empty elements as ‘’ instead of ‘’, and text mode will skip over elements and only output the text chunks. If you set the ‘tag’ attribute of an element to ‘None’ but leave its children in place, the element will be omitted when the tree is written out, so you don’t need to do more extensive rearrangement to remove a single element. Namespace handling has also been improved. All ‘xmlns:’ declarations are now output on the root element, not scattered throughout the resulting XML. You can set the default namespace for a tree by setting the ‘default_namespace’ attribute and can register new prefixes with *note register_namespace(): b50. In XML mode, you can use the true/false `xml_declaration' parameter to suppress the XML declaration. * New *note Element: ac4. method: *note extend(): b51. appends the items from a sequence to the element’s children. Elements themselves behave like sequences, so it’s easy to move children from one element to another: from xml.etree import ElementTree as ET t = ET.XML(""" 1 2 3 """) new = ET.XML('') new.extend(t) # Outputs 1... print ET.tostring(new) * New ‘Element’ method: *note iter(): ce7. yields the children of the element as a generator. It’s also possible to write ‘for child in elem:’ to loop over an element’s children. The existing method ‘getiterator()’ is now deprecated, as is ‘getchildren()’ which constructs and returns a list of children. * New ‘Element’ method: *note itertext(): b53. yields all chunks of text that are descendants of the element. For example: t = ET.XML(""" 1 2 3 """) # Outputs ['\n ', '1', ' ', '2', ' ', '3', '\n'] print list(t.itertext()) * Deprecated: using an element as a Boolean (i.e., ‘if elem:’) would return true if the element had any children, or false if there were no children. This behaviour is confusing – ‘None’ is false, but so is a childless element? – so it will now trigger a *note FutureWarning: 325. In your code, you should be explicit: write ‘len(elem) != 0’ if you’re interested in the number of children, or ‘elem is not None’. Fredrik Lundh develops ElementTree and produced the 1.3 version; you can read his article describing 1.3 at ‘http://effbot.org/zone/elementtree-13-intro.htm’. Florent Xicluna updated the version included with Python, after discussions on python-dev and in bpo-6472(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue6472  File: python.info, Node: Build and C API Changes<8>, Next: Other Changes and Fixes, Prev: New and Improved Modules, Up: What’s New in Python 2 7 1.10.12 Build and C API Changes ------------------------------- Changes to Python’s build process and to the C API include: * The latest release of the GNU Debugger, GDB 7, can be scripted using Python(1). When you begin debugging an executable program P, GDB will look for a file named ‘P-gdb.py’ and automatically read it. Dave Malcolm contributed a ‘python-gdb.py’ that adds a number of commands useful when debugging Python itself. For example, ‘py-up’ and ‘py-down’ go up or down one Python stack frame, which usually corresponds to several C stack frames. ‘py-print’ prints the value of a Python variable, and ‘py-bt’ prints the Python stack trace. (Added as a result of bpo-8032(2).) * If you use the ‘.gdbinit’ file provided with Python, the “pyo” macro in the 2.7 version now works correctly when the thread being debugged doesn’t hold the GIL; the macro now acquires it before printing. (Contributed by Victor Stinner; bpo-3632(3).) * *note Py_AddPendingCall(): ce9. is now thread-safe, letting any worker thread submit notifications to the main Python thread. This is particularly useful for asynchronous IO operations. (Contributed by Kristján Valur Jónsson; bpo-4293(4).) * New function: *note PyCode_NewEmpty(): cea. creates an empty code object; only the filename, function name, and first line number are required. This is useful for extension modules that are attempting to construct a more useful traceback stack. Previously such extensions needed to call *note PyCode_New(): 272, which had many more arguments. (Added by Jeffrey Yasskin.) * New function: *note PyErr_NewExceptionWithDoc(): bff. creates a new exception class, just as the existing *note PyErr_NewException(): c00. does, but takes an extra ‘char *’ argument containing the docstring for the new exception class. (Added by ‘lekma’ on the Python bug tracker; bpo-7033(5).) * New function: *note PyFrame_GetLineNumber(): ceb. takes a frame object and returns the line number that the frame is currently executing. Previously code would need to get the index of the bytecode instruction currently executing, and then look up the line number corresponding to that address. (Added by Jeffrey Yasskin.) * New functions: *note PyLong_AsLongAndOverflow(): bfd. and *note PyLong_AsLongLongAndOverflow(): bfc. approximates a Python long integer as a C ‘long’ or ‘long long’. If the number is too large to fit into the output type, an `overflow' flag is set and returned to the caller. (Contributed by Case Van Horsen; bpo-7528(6) and bpo-7767(7).) * New function: stemming from the rewrite of string-to-float conversion, a new *note PyOS_string_to_double(): c23. function was added. The old ‘PyOS_ascii_strtod()’ and ‘PyOS_ascii_atof()’ functions are now deprecated. * New function: *note PySys_SetArgvEx(): bfa. sets the value of ‘sys.argv’ and can optionally update ‘sys.path’ to include the directory containing the script named by ‘sys.argv[0]’ depending on the value of an `updatepath' parameter. This function was added to close a security hole for applications that embed Python. The old function, *note PySys_SetArgv(): cec, would always update ‘sys.path’, and sometimes it would add the current directory. This meant that, if you ran an application embedding Python in a directory controlled by someone else, attackers could put a Trojan-horse module in the directory (say, a file named ‘os.py’) that your application would then import and run. If you maintain a C/C++ application that embeds Python, check whether you’re calling *note PySys_SetArgv(): cec. and carefully consider whether the application should be using *note PySys_SetArgvEx(): bfa. with `updatepath' set to false. Security issue reported as CVE-2008-5983(8); discussed in bpo-5753(9), and fixed by Antoine Pitrou. * New macros: the Python header files now define the following macros: ‘Py_ISALNUM’, ‘Py_ISALPHA’, ‘Py_ISDIGIT’, ‘Py_ISLOWER’, ‘Py_ISSPACE’, ‘Py_ISUPPER’, ‘Py_ISXDIGIT’, ‘Py_TOLOWER’, and ‘Py_TOUPPER’. All of these functions are analogous to the C standard macros for classifying characters, but ignore the current locale setting, because in several places Python needs to analyze characters in a locale-independent way. (Added by Eric Smith; bpo-5793(10).) * Removed function: ‘PyEval_CallObject’ is now only available as a macro. A function version was being kept around to preserve ABI linking compatibility, but that was in 1997; it can certainly be deleted by now. (Removed by Antoine Pitrou; bpo-8276(11).) * New format codes: the ‘PyFormat_FromString()’, ‘PyFormat_FromStringV()’, and *note PyErr_Format(): 7aa. functions now accept ‘%lld’ and ‘%llu’ format codes for displaying C’s ‘long long’ types. (Contributed by Mark Dickinson; bpo-7228(12).) * The complicated interaction between threads and process forking has been changed. Previously, the child process created by *note os.fork(): 961. might fail because the child is created with only a single thread running, the thread performing the *note os.fork(): 961. If other threads were holding a lock, such as Python’s import lock, when the fork was performed, the lock would still be marked as “held” in the new process. But in the child process nothing would ever release the lock, since the other threads weren’t replicated, and the child process would no longer be able to perform imports. Python 2.7 acquires the import lock before performing an *note os.fork(): 961, and will also clean up any locks created using the *note threading: 109. module. C extension modules that have internal locks, or that call ‘fork()’ themselves, will not benefit from this clean-up. (Fixed by Thomas Wouters; bpo-1590864(13).) * The *note Py_Finalize(): ced. function now calls the internal ‘threading._shutdown()’ function; this prevents some exceptions from being raised when an interpreter shuts down. (Patch by Adam Olsen; bpo-1722344(14).) * When using the *note PyMemberDef: 426. structure to define attributes of a type, Python will no longer let you try to delete or set a ‘T_STRING_INPLACE’ attribute. * Global symbols defined by the *note ctypes: 2b. module are now prefixed with ‘Py’, or with ‘_ctypes’. (Implemented by Thomas Heller; bpo-3102(15).) * New configure option: the ‘--with-system-expat’ switch allows building the ‘pyexpat’ module to use the system Expat library. (Contributed by Arfrever Frehtes Taifersar Arahesis; bpo-7609(16).) * New configure option: the ‘--with-valgrind’ option will now disable the pymalloc allocator, which is difficult for the Valgrind memory-error detector to analyze correctly. Valgrind will therefore be better at detecting memory leaks and overruns. (Contributed by James Henstridge; bpo-2422(17).) * New configure option: you can now supply an empty string to ‘--with-dbmliborder=’ in order to disable all of the various DBM modules. (Added by Arfrever Frehtes Taifersar Arahesis; bpo-6491(18).) * The ‘configure’ script now checks for floating-point rounding bugs on certain 32-bit Intel chips and defines a ‘X87_DOUBLE_ROUNDING’ preprocessor definition. No code currently uses this definition, but it’s available if anyone wishes to use it. (Added by Mark Dickinson; bpo-2937(19).) ‘configure’ also now sets a ‘LDCXXSHARED’ Makefile variable for supporting C++ linking. (Contributed by Arfrever Frehtes Taifersar Arahesis; bpo-1222585(20).) * The build process now creates the necessary files for pkg-config support. (Contributed by Clinton Roy; bpo-3585(21).) * The build process now supports Subversion 1.7. (Contributed by Arfrever Frehtes Taifersar Arahesis; bpo-6094(22).) * Menu: * Capsules:: * Port-Specific Changes; Windows: Port-Specific Changes Windows. * Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X. * Port-Specific Changes; FreeBSD: Port-Specific Changes FreeBSD. ---------- Footnotes ---------- (1) https://sourceware.org/gdb/current/onlinedocs/gdb/Python.html (2) https://bugs.python.org/issue8032 (3) https://bugs.python.org/issue3632 (4) https://bugs.python.org/issue4293 (5) https://bugs.python.org/issue7033 (6) https://bugs.python.org/issue7528 (7) https://bugs.python.org/issue7767 (8) https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983 (9) https://bugs.python.org/issue5753 (10) https://bugs.python.org/issue5793 (11) https://bugs.python.org/issue8276 (12) https://bugs.python.org/issue7228 (13) https://bugs.python.org/issue1590864 (14) https://bugs.python.org/issue1722344 (15) https://bugs.python.org/issue3102 (16) https://bugs.python.org/issue7609 (17) https://bugs.python.org/issue2422 (18) https://bugs.python.org/issue6491 (19) https://bugs.python.org/issue2937 (20) https://bugs.python.org/issue1222585 (21) https://bugs.python.org/issue3585 (22) https://bugs.python.org/issue6094  File: python.info, Node: Capsules, Next: Port-Specific Changes Windows, Up: Build and C API Changes<8> 1.10.12.1 Capsules .................. Python 3.1 adds a new C datatype, *note PyCapsule: c07, for providing a C API to an extension module. A capsule is essentially the holder of a C ‘void *’ pointer, and is made available as a module attribute; for example, the *note socket: ef. module’s API is exposed as ‘socket.CAPI’, and *note unicodedata: 11a. exposes ‘ucnhash_CAPI’. Other extensions can import the module, access its dictionary to get the capsule object, and then get the ‘void *’ pointer, which will usually point to an array of pointers to the module’s various API functions. There is an existing data type already used for this, ‘PyCObject’, but it doesn’t provide type safety. Evil code written in pure Python could cause a segmentation fault by taking a ‘PyCObject’ from module A and somehow substituting it for the ‘PyCObject’ in module B. Capsules know their own name, and getting the pointer requires providing the name: void *vtable; if (!PyCapsule_IsValid(capsule, "mymodule.CAPI") { PyErr_SetString(PyExc_ValueError, "argument type invalid"); return NULL; } vtable = PyCapsule_GetPointer(capsule, "mymodule.CAPI"); You are assured that ‘vtable’ points to whatever you’re expecting. If a different capsule was passed in, *note PyCapsule_IsValid(): cf0. would detect the mismatched name and return false. Refer to *note Providing a C API for an Extension Module: cf1. for more information on using these objects. Python 2.7 now uses capsules internally to provide various extension-module APIs, but the ‘PyCObject_AsVoidPtr()’ was modified to handle capsules, preserving compile-time compatibility with the ‘CObject’ interface. Use of ‘PyCObject_AsVoidPtr()’ will signal a *note PendingDeprecationWarning: 279, which is silent by default. Implemented in Python 3.1 and backported to 2.7 by Larry Hastings; discussed in bpo-5630(1). ---------- Footnotes ---------- (1) https://bugs.python.org/issue5630  File: python.info, Node: Port-Specific Changes Windows, Next: Port-Specific Changes Mac OS X, Prev: Capsules, Up: Build and C API Changes<8> 1.10.12.2 Port-Specific Changes: Windows ........................................ * The *note msvcrt: b6. module now contains some constants from the ‘crtassem.h’ header file: ‘CRT_ASSEMBLY_VERSION’, ‘VC_ASSEMBLY_PUBLICKEYTOKEN’, and ‘LIBRARIES_ASSEMBLY_NAME_PREFIX’. (Contributed by David Cournapeau; bpo-4365(1).) * The ‘_winreg’ module for accessing the registry now implements the ‘CreateKeyEx()’ and ‘DeleteKeyEx()’ functions, extended versions of previously-supported functions that take several extra arguments. The ‘DisableReflectionKey()’, ‘EnableReflectionKey()’, and ‘QueryReflectionKey()’ were also tested and documented. (Implemented by Brian Curtin: bpo-7347(2).) * The new ‘_beginthreadex()’ API is used to start threads, and the native thread-local storage functions are now used. (Contributed by Kristján Valur Jónsson; bpo-3582(3).) * The *note os.kill(): cf3. function now works on Windows. The signal value can be the constants ‘CTRL_C_EVENT’, ‘CTRL_BREAK_EVENT’, or any integer. The first two constants will send ‘Control-C’ and ‘Control-Break’ keystroke events to subprocesses; any other value will use the ‘TerminateProcess()’ API. (Contributed by Miki Tebeka; bpo-1220212(4).) * The *note os.listdir(): a41. function now correctly fails for an empty path. (Fixed by Hirokazu Yamamoto; bpo-5913(5).) * The ‘mimelib’ module will now read the MIME database from the Windows registry when initializing. (Patch by Gabriel Genellina; bpo-4969(6).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4365 (2) https://bugs.python.org/issue7347 (3) https://bugs.python.org/issue3582 (4) https://bugs.python.org/issue1220212 (5) https://bugs.python.org/issue5913 (6) https://bugs.python.org/issue4969  File: python.info, Node: Port-Specific Changes Mac OS X, Next: Port-Specific Changes FreeBSD, Prev: Port-Specific Changes Windows, Up: Build and C API Changes<8> 1.10.12.3 Port-Specific Changes: Mac OS X ......................................... * The path ‘/Library/Python/2.7/site-packages’ is now appended to ‘sys.path’, in order to share added packages between the system installation and a user-installed copy of the same version. (Changed by Ronald Oussoren; bpo-4865(1).) Changed in version 2.7.13: As of 2.7.13, this change was removed. ‘/Library/Python/2.7/site-packages’, the site-packages directory used by the Apple-supplied system Python 2.7 is no longer appended to ‘sys.path’ for user-installed Pythons such as from the python.org installers. As of macOS 10.12, Apple changed how the system site-packages directory is configured, which could cause installation of pip components, like setuptools, to fail. Packages installed for the system Python will no longer be shared with user-installed Pythons. (bpo-28440(2)) ---------- Footnotes ---------- (1) https://bugs.python.org/issue4865 (2) https://bugs.python.org/issue28440  File: python.info, Node: Port-Specific Changes FreeBSD, Prev: Port-Specific Changes Mac OS X, Up: Build and C API Changes<8> 1.10.12.4 Port-Specific Changes: FreeBSD ........................................ * FreeBSD 7.1’s ‘SO_SETFIB’ constant, used with ‘getsockopt()’/‘setsockopt()’ to select an alternate routing table, is now available in the *note socket: ef. module. (Added by Kyle VanderBeek; bpo-8235(1).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue8235  File: python.info, Node: Other Changes and Fixes, Next: Porting to Python 2 7, Prev: Build and C API Changes<8>, Up: What’s New in Python 2 7 1.10.13 Other Changes and Fixes ------------------------------- * Two benchmark scripts, ‘iobench’ and ‘ccbench’, were added to the ‘Tools’ directory. ‘iobench’ measures the speed of the built-in file I/O objects returned by *note open(): 4f0. while performing various operations, and ‘ccbench’ is a concurrency benchmark that tries to measure computing throughput, thread switching latency, and IO processing bandwidth when performing several tasks using a varying number of threads. * The ‘Tools/i18n/msgfmt.py’ script now understands plural forms in ‘.po’ files. (Fixed by Martin von Löwis; bpo-5464(1).) * When importing a module from a ‘.pyc’ or ‘.pyo’ file with an existing ‘.py’ counterpart, the ‘co_filename’ attributes of the resulting code objects are overwritten when the original filename is obsolete. This can happen if the file has been renamed, moved, or is accessed through different paths. (Patch by Ziga Seilnacht and Jean-Paul Calderone; bpo-1180193(2).) * The ‘regrtest.py’ script now takes a ‘--randseed=’ switch that takes an integer that will be used as the random seed for the ‘-r’ option that executes tests in random order. The ‘-r’ option also reports the seed that was used (Added by Collin Winter.) * Another ‘regrtest.py’ switch is ‘-j’, which takes an integer specifying how many tests run in parallel. This allows reducing the total runtime on multi-core machines. This option is compatible with several other options, including the ‘-R’ switch which is known to produce long runtimes. (Added by Antoine Pitrou, bpo-6152(3).) This can also be used with a new ‘-F’ switch that runs selected tests in a loop until they fail. (Added by Antoine Pitrou; bpo-7312(4).) * When executed as a script, the ‘py_compile.py’ module now accepts ‘'-'’ as an argument, which will read standard input for the list of filenames to be compiled. (Contributed by Piotr Ożarowski; bpo-8233(5).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue5464 (2) https://bugs.python.org/issue1180193 (3) https://bugs.python.org/issue6152 (4) https://bugs.python.org/issue7312 (5) https://bugs.python.org/issue8233  File: python.info, Node: Porting to Python 2 7, Next: New Features Added to Python 2 7 Maintenance Releases, Prev: Other Changes and Fixes, Up: What’s New in Python 2 7 1.10.14 Porting to Python 2.7 ----------------------------- This section lists previously described changes and other bugfixes that may require changes to your code: * The *note range(): 9be. function processes its arguments more consistently; it will now call *note __int__(): 18b. on non-float, non-integer arguments that are supplied to it. (Fixed by Alexander Belopolsky; bpo-1533(1).) * The string *note format(): 4db. method changed the default precision used for floating-point and complex numbers from 6 decimal places to 12, which matches the precision used by *note str(): 330. (Changed by Eric Smith; bpo-5920(2).) * Because of an optimization for the *note with: 6e9. statement, the special methods *note __enter__(): c95. and *note __exit__(): c96. must belong to the object’s type, and cannot be directly attached to the object’s instance. This affects new-style classes (derived from *note object: 2b0.) and C extension types. (bpo-6101(3).) * Due to a bug in Python 2.6, the `exc_value' parameter to *note __exit__(): c96. methods was often the string representation of the exception, not an instance. This was fixed in 2.7, so `exc_value' will be an instance as expected. (Fixed by Florent Xicluna; bpo-7853(4).) * When a restricted set of attributes were set using ‘__slots__’, deleting an unset attribute would not raise *note AttributeError: 39b. as you would expect. Fixed by Benjamin Peterson; bpo-7604(5).) In the standard library: * Operations with *note datetime: 194. instances that resulted in a year falling outside the supported range didn’t always raise *note OverflowError: 960. Such errors are now checked more carefully and will now raise the exception. (Reported by Mark Leander, patch by Anand B. Pillai and Alexander Belopolsky; bpo-7150(6).) * When using *note Decimal: 188. instances with a string’s *note format(): 4db. method, the default alignment was previously left-alignment. This has been changed to right-alignment, which might change the output of your programs. (Changed by Mark Dickinson; bpo-6857(7).) Comparisons involving a signaling NaN value (or ‘sNAN’) now signal *note InvalidOperation: 9eb. instead of silently returning a true or false value depending on the comparison operator. Quiet NaN values (or ‘NaN’) are now hashable. (Fixed by Mark Dickinson; bpo-7279(8).) * The ElementTree library, ‘xml.etree’, no longer escapes ampersands and angle brackets when outputting an XML processing instruction (which looks like ‘’) or comment (which looks like ‘’). (Patch by Neil Muller; bpo-2746(9).) * The ‘readline()’ method of ‘StringIO’ objects now does nothing when a negative length is requested, as other file-like objects do. (bpo-7348(10)). * The *note syslog: ff. module will now use the value of ‘sys.argv[0]’ as the identifier instead of the previous default value of ‘'python'’. (Changed by Sean Reifschneider; bpo-8451(11).) * The *note tarfile: 101. module’s default error handling has changed, to no longer suppress fatal errors. The default error level was previously 0, which meant that errors would only result in a message being written to the debug log, but because the debug log is not activated by default, these errors go unnoticed. The default error level is now 1, which raises an exception if there’s an error. (Changed by Lars Gustäbel; bpo-7357(12).) * The ‘urlparse’ module’s ‘urlsplit()’ now handles unknown URL schemes in a fashion compliant with RFC 3986(13): if the URL is of the form ‘"://..."’, the text before the ‘://’ is treated as the scheme, even if it’s a made-up scheme that the module doesn’t know about. This change may break code that worked around the old behaviour. For example, Python 2.6.4 or 2.5 will return the following: >>> import urlparse >>> urlparse.urlsplit('invented://host/filename?query') ('invented', '', '//host/filename?query', '', '') Python 2.7 (and Python 2.6.5) will return: >>> import urlparse >>> urlparse.urlsplit('invented://host/filename?query') ('invented', 'host', '/filename?query', '', '') (Python 2.7 actually produces slightly different output, since it returns a named tuple instead of a standard tuple.) For C extensions: * C extensions that use integer format codes with the ‘PyArg_Parse*’ family of functions will now raise a *note TypeError: 192. exception instead of triggering a *note DeprecationWarning: 278. (bpo-5080(14)). * Use the new *note PyOS_string_to_double(): c23. function instead of the old ‘PyOS_ascii_strtod()’ and ‘PyOS_ascii_atof()’ functions, which are now deprecated. For applications that embed Python: * The *note PySys_SetArgvEx(): bfa. function was added, letting applications close a security hole when the existing *note PySys_SetArgv(): cec. function was used. Check whether you’re calling *note PySys_SetArgv(): cec. and carefully consider whether the application should be using *note PySys_SetArgvEx(): bfa. with `updatepath' set to false. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1533 (2) https://bugs.python.org/issue5920 (3) https://bugs.python.org/issue6101 (4) https://bugs.python.org/issue7853 (5) https://bugs.python.org/issue7604 (6) https://bugs.python.org/issue7150 (7) https://bugs.python.org/issue6857 (8) https://bugs.python.org/issue7279 (9) https://bugs.python.org/issue2746 (10) https://bugs.python.org/issue7348 (11) https://bugs.python.org/issue8451 (12) https://bugs.python.org/issue7357 (13) https://tools.ietf.org/html/rfc3986.html (14) https://bugs.python.org/issue5080  File: python.info, Node: New Features Added to Python 2 7 Maintenance Releases, Next: Acknowledgements, Prev: Porting to Python 2 7, Up: What’s New in Python 2 7 1.10.15 New Features Added to Python 2.7 Maintenance Releases ------------------------------------------------------------- New features may be added to Python 2.7 maintenance releases when the situation genuinely calls for it. Any such additions must go through the Python Enhancement Proposal process, and make a compelling case for why they can’t be adequately addressed by either adding the new feature solely to Python 3, or else by publishing it on the Python Package Index. In addition to the specific proposals listed below, there is a general exemption allowing new ‘-3’ warnings to be added in any Python 2.7 maintenance release. * Menu: * Two new environment variables for debug mode:: * PEP 434; IDLE Enhancement Exception for All Branches: PEP 434 IDLE Enhancement Exception for All Branches. * PEP 466; Network Security Enhancements for Python 2.7: PEP 466 Network Security Enhancements for Python 2 7. * PEP 477; Backport ensurepip (PEP 453) to Python 2.7: PEP 477 Backport ensurepip PEP 453 to Python 2 7. * PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients<2>. * PEP 493; HTTPS verification migration tools for Python 2.7: PEP 493 HTTPS verification migration tools for Python 2 7. * New make regen-all build target: New make regen-all build target<3>. * Removal of make touch build target: Removal of make touch build target<3>.  File: python.info, Node: Two new environment variables for debug mode, Next: PEP 434 IDLE Enhancement Exception for All Branches, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.1 Two new environment variables for debug mode ...................................................... In debug mode, the ‘[xxx refs]’ statistic is not written by default, the ‘PYTHONSHOWREFCOUNT’ environment variable now must also be set. (Contributed by Victor Stinner; bpo-31733(1).) When Python is compiled with ‘COUNT_ALLOC’ defined, allocation counts are no longer dumped by default anymore: the ‘PYTHONSHOWALLOCCOUNT’ environment variable must now also be set. Moreover, allocation counts are now dumped into stderr, rather than stdout. (Contributed by Victor Stinner; bpo-31692(2).) New in version 2.7.15. ---------- Footnotes ---------- (1) https://bugs.python.org/issue31733 (2) https://bugs.python.org/issue31692  File: python.info, Node: PEP 434 IDLE Enhancement Exception for All Branches, Next: PEP 466 Network Security Enhancements for Python 2 7, Prev: Two new environment variables for debug mode, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.2 PEP 434: IDLE Enhancement Exception for All Branches .............................................................. PEP 434(1) describes a general exemption for changes made to the IDLE development environment shipped along with Python. This exemption makes it possible for the IDLE developers to provide a more consistent user experience across all supported versions of Python 2 and 3. For details of any IDLE changes, refer to the NEWS file for the specific release. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0434  File: python.info, Node: PEP 466 Network Security Enhancements for Python 2 7, Next: PEP 477 Backport ensurepip PEP 453 to Python 2 7, Prev: PEP 434 IDLE Enhancement Exception for All Branches, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.3 PEP 466: Network Security Enhancements for Python 2.7 ............................................................... PEP 466(1) describes a number of network security enhancement proposals that have been approved for inclusion in Python 2.7 maintenance releases, with the first of those changes appearing in the Python 2.7.7 release. PEP 466(2) related features added in Python 2.7.7: * *note hmac.compare_digest(): a0c. was backported from Python 3 to make a timing attack resistant comparison operation available to Python 2 applications. (Contributed by Alex Gaynor; bpo-21306(3).) * OpenSSL 1.0.1g was upgraded in the official Windows installers published on python.org. (Contributed by Zachary Ware; bpo-21462(4).) PEP 466(5) related features added in Python 2.7.8: * *note hashlib.pbkdf2_hmac(): 7e6. was backported from Python 3 to make a hashing algorithm suitable for secure password storage broadly available to Python 2 applications. (Contributed by Alex Gaynor; bpo-21304(6).) * OpenSSL 1.0.1h was upgraded for the official Windows installers published on python.org. (contributed by Zachary Ware in bpo-21671(7) for CVE-2014-0224) PEP 466(8) related features added in Python 2.7.9: * Most of Python 3.4’s *note ssl: f3. module was backported. This means *note ssl: f3. now supports Server Name Indication, TLS1.x settings, access to the platform certificate store, the *note SSLContext: 3e4. class, and other features. (Contributed by Alex Gaynor and David Reid; bpo-21308(9).) Refer to the “Version added: 2.7.9” notes in the module documentation for specific details. * *note os.urandom(): 4d1. was changed to cache a file descriptor to ‘/dev/urandom’ instead of reopening ‘/dev/urandom’ on every call. (Contributed by Alex Gaynor; bpo-21305(10).) * *note hashlib.algorithms_guaranteed: cfc. and *note hashlib.algorithms_available: cfd. were backported from Python 3 to make it easier for Python 2 applications to select the strongest available hash algorithm. (Contributed by Alex Gaynor in bpo-21307(11)) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0466 (2) https://www.python.org/dev/peps/pep-0466 (3) https://bugs.python.org/issue21306 (4) https://bugs.python.org/issue21462 (5) https://www.python.org/dev/peps/pep-0466 (6) https://bugs.python.org/issue21304 (7) https://bugs.python.org/issue21671 (8) https://www.python.org/dev/peps/pep-0466 (9) https://bugs.python.org/issue21308 (10) https://bugs.python.org/issue21305 (11) https://bugs.python.org/issue21307  File: python.info, Node: PEP 477 Backport ensurepip PEP 453 to Python 2 7, Next: PEP 476 Enabling certificate verification by default for stdlib http clients<2>, Prev: PEP 466 Network Security Enhancements for Python 2 7, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.4 PEP 477: Backport ensurepip (PEP 453) to Python 2.7 ............................................................. PEP 477(1) approves the inclusion of the PEP 453(2) ensurepip module and the improved documentation that was enabled by it in the Python 2.7 maintenance releases, appearing first in the Python 2.7.9 release. * Menu: * Bootstrapping pip By Default: Bootstrapping pip By Default<2>. * Documentation Changes: Documentation Changes<2>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0477 (2) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: Bootstrapping pip By Default<2>, Next: Documentation Changes<2>, Up: PEP 477 Backport ensurepip PEP 453 to Python 2 7 1.10.15.5 Bootstrapping pip By Default ...................................... The new *note ensurepip: 7a. module (defined in PEP 453(1)) provides a standard cross-platform mechanism to bootstrap the pip installer into Python installations. The version of ‘pip’ included with Python 2.7.9 is ‘pip’ 1.5.6, and future 2.7.x maintenance releases will update the bundled version to the latest version of ‘pip’ that is available at the time of creating the release candidate. By default, the commands ‘pip’, ‘pipX’ and ‘pipX.Y’ will be installed on all platforms (where X.Y stands for the version of the Python installation), along with the ‘pip’ Python package and its dependencies. For CPython *note source builds on POSIX systems: 7f3, the ‘make install’ and ‘make altinstall’ commands do not bootstrap ‘pip’ by default. This behaviour can be controlled through configure options, and overridden through Makefile options. On Windows and Mac OS X, the CPython installers now default to installing ‘pip’ along with CPython itself (users may opt out of installing it during the installation process). Window users will need to opt in to the automatic ‘PATH’ modifications to have ‘pip’ available from the command line by default, otherwise it can still be accessed through the Python launcher for Windows as ‘py -m pip’. As discussed in the PEP(2), platform packagers may choose not to install these commands by default, as long as, when invoked, they provide clear and simple directions on how to install them on that platform (usually using the system package manager). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0453 (2) https://www.python.org/dev/peps/pep-0477/#disabling-ensurepip-by-downstream-distributors  File: python.info, Node: Documentation Changes<2>, Prev: Bootstrapping pip By Default<2>, Up: PEP 477 Backport ensurepip PEP 453 to Python 2 7 1.10.15.6 Documentation Changes ............................... As part of this change, the *note Installing Python Modules: 7f5. and *note Distributing Python Modules: 7f6. sections of the documentation have been completely redesigned as short getting started and FAQ documents. Most packaging documentation has now been moved out to the Python Packaging Authority maintained Python Packaging User Guide(1) and the documentation of the individual projects. However, as this migration is currently still incomplete, the legacy versions of those guides remaining available as *note Installing Python Modules (Legacy version): 7f7. and *note Distributing Python Modules (Legacy version): 7f8. See also ........ PEP 453(2) – Explicit bootstrapping of pip in Python installations PEP written by Donald Stufft and Nick Coghlan, implemented by Donald Stufft, Nick Coghlan, Martin von Löwis and Ned Deily. ---------- Footnotes ---------- (1) http://packaging.python.org (2) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: PEP 476 Enabling certificate verification by default for stdlib http clients<2>, Next: PEP 493 HTTPS verification migration tools for Python 2 7, Prev: PEP 477 Backport ensurepip PEP 453 to Python 2 7, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.7 PEP 476: Enabling certificate verification by default for stdlib http clients ....................................................................................... PEP 476(1) updated ‘httplib’ and modules which use it, such as ‘urllib2’ and ‘xmlrpclib’, to now verify that the server presents a certificate which is signed by a Certificate Authority in the platform trust store and whose hostname matches the hostname being requested by default, significantly improving security for many applications. This change was made in the Python 2.7.9 release. For applications which require the old previous behavior, they can pass an alternate context: import urllib2 import ssl # This disables all verification context = ssl._create_unverified_context() # This allows using a specific certificate for the host, which doesn't need # to be in the trust store context = ssl.create_default_context(cafile="/path/to/file.crt") urllib2.urlopen("https://invalid-cert", context=context) ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0476  File: python.info, Node: PEP 493 HTTPS verification migration tools for Python 2 7, Next: New make regen-all build target<3>, Prev: PEP 476 Enabling certificate verification by default for stdlib http clients<2>, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.8 PEP 493: HTTPS verification migration tools for Python 2.7 .................................................................... PEP 493(1) provides additional migration tools to support a more incremental infrastructure upgrade process for environments containing applications and services relying on the historically permissive processing of server certificates when establishing client HTTPS connections. These additions were made in the Python 2.7.12 release. These tools are intended for use in cases where affected applications and services can’t be modified to explicitly pass a more permissive SSL context when establishing the connection. For applications and services which can’t be modified at all, the new ‘PYTHONHTTPSVERIFY’ environment variable may be set to ‘0’ to revert an entire Python process back to the default permissive behaviour of Python 2.7.8 and earlier. For cases where the connection establishment code can’t be modified, but the overall application can be, the new ‘ssl._https_verify_certificates()’ function can be used to adjust the default behaviour at runtime. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0493  File: python.info, Node: New make regen-all build target<3>, Next: Removal of make touch build target<3>, Prev: PEP 493 HTTPS verification migration tools for Python 2 7, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.9 New ‘make regen-all’ build target ........................................... To simplify cross-compilation, and to ensure that CPython can reliably be compiled without requiring an existing version of Python to already be available, the autotools-based build system no longer attempts to implicitly recompile generated files based on file modification times. Instead, a new ‘make regen-all’ command has been added to force regeneration of these files when desired (e.g. after an initial version of Python has already been built based on the pregenerated versions). More selective regeneration targets are also defined - see Makefile.pre.in(1) for details. (Contributed by Victor Stinner in bpo-23404(2).) New in version 2.7.14. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Makefile.pre.in (2) https://bugs.python.org/issue23404  File: python.info, Node: Removal of make touch build target<3>, Prev: New make regen-all build target<3>, Up: New Features Added to Python 2 7 Maintenance Releases 1.10.15.10 Removal of ‘make touch’ build target ............................................... The ‘make touch’ build target previously used to request implicit regeneration of generated files by updating their modification times has been removed. It has been replaced by the new ‘make regen-all’ target. (Contributed by Victor Stinner in bpo-23404(1).) Changed in version 2.7.14. ---------- Footnotes ---------- (1) https://bugs.python.org/issue23404  File: python.info, Node: Acknowledgements, Prev: New Features Added to Python 2 7 Maintenance Releases, Up: What’s New in Python 2 7 1.10.16 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Nick Coghlan, Philip Jenvey, Ryan Lovett, R. David Murray, Hugh Secker-Walker.  File: python.info, Node: What’s New in Python 2 6, Next: What’s New in Python 2 5, Prev: What’s New in Python 2 7, Up: What’s New in Python 1.11 What’s New in Python 2.6 ============================= Author: A.M. Kuchling (amk at amk.ca) This article explains the new features in Python 2.6, released on October 1 2008. The release schedule is described in PEP 361(1). The major theme of Python 2.6 is preparing the migration path to Python 3.0, a major redesign of the language. Whenever possible, Python 2.6 incorporates new features and syntax from 3.0 while remaining compatible with existing code by not removing older features or syntax. When it’s not possible to do that, Python 2.6 tries to do what it can, adding compatibility functions in a ‘future_builtins’ module and a ‘-3’ switch to warn about usages that will become unsupported in 3.0. Some significant new packages have been added to the standard library, such as the *note multiprocessing: b7. and *note json: a4. modules, but there aren’t many new features that aren’t related to Python 3.0 in some way. Python 2.6 also sees a number of improvements and bugfixes throughout the source. A search through the change logs finds there were 259 patches applied and 612 bugs fixed between Python 2.5 and 2.6. Both figures are likely to be underestimates. This article doesn’t attempt to provide a complete specification of the new features, but instead provides a convenient overview. For full details, you should refer to the documentation for Python 2.6. If you want to understand the rationale for the design and implementation, refer to the PEP for a particular new feature. Whenever possible, “What’s New in Python” links to the bug/patch item for each change. * Menu: * Python 3.0: Python 3 0. * Changes to the Development Process:: * PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement. * PEP 366; Explicit Relative Imports From a Main Module: PEP 366 Explicit Relative Imports From a Main Module. * PEP 370; Per-user site-packages Directory: PEP 370 Per-user site-packages Directory. * PEP 371; The multiprocessing Package: PEP 371 The multiprocessing Package. * PEP 3101; Advanced String Formatting: PEP 3101 Advanced String Formatting. * PEP 3105; print As a Function: PEP 3105 print As a Function. * PEP 3110; Exception-Handling Changes: PEP 3110 Exception-Handling Changes. * PEP 3112; Byte Literals: PEP 3112 Byte Literals. * PEP 3116; New I/O Library: PEP 3116 New I/O Library. * PEP 3118; Revised Buffer Protocol: PEP 3118 Revised Buffer Protocol. * PEP 3119; Abstract Base Classes: PEP 3119 Abstract Base Classes. * PEP 3127; Integer Literal Support and Syntax: PEP 3127 Integer Literal Support and Syntax. * PEP 3129; Class Decorators: PEP 3129 Class Decorators. * PEP 3141; A Type Hierarchy for Numbers: PEP 3141 A Type Hierarchy for Numbers. * Other Language Changes: Other Language Changes<10>. * New and Improved Modules: New and Improved Modules<2>. * Deprecations and Removals:: * Build and C API Changes: Build and C API Changes<9>. * Porting to Python 2.6: Porting to Python 2 6. * Acknowledgements: Acknowledgements<2>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0361  File: python.info, Node: Python 3 0, Next: Changes to the Development Process, Up: What’s New in Python 2 6 1.11.1 Python 3.0 ----------------- The development cycle for Python versions 2.6 and 3.0 was synchronized, with the alpha and beta releases for both versions being made on the same days. The development of 3.0 has influenced many features in 2.6. Python 3.0 is a far-ranging redesign of Python that breaks compatibility with the 2.x series. This means that existing Python code will need some conversion in order to run on Python 3.0. However, not all the changes in 3.0 necessarily break compatibility. In cases where new features won’t cause existing code to break, they’ve been backported to 2.6 and are described in this document in the appropriate place. Some of the 3.0-derived features are: * A *note __complex__(): 18d. method for converting objects to a complex number. * Alternate syntax for catching exceptions: ‘except TypeError as exc’. * The addition of *note functools.reduce(): c6f. as a synonym for the built-in ‘reduce()’ function. Python 3.0 adds several new built-in functions and changes the semantics of some existing builtins. Functions that are new in 3.0 such as *note bin(): c40. have simply been added to Python 2.6, but existing builtins haven’t been changed; instead, the ‘future_builtins’ module has versions with the new 3.0 semantics. Code written to be compatible with 3.0 can do ‘from future_builtins import hex, map’ as necessary. A new command-line switch, ‘-3’, enables warnings about features that will be removed in Python 3.0. You can run code with this switch to see how much work will be necessary to port code to 3.0. The value of this switch is available to Python code as the boolean variable ‘sys.py3kwarning’, and to C extension code as ‘Py_Py3kWarningFlag’. See also ........ The 3xxx series of PEPs, which contains proposals for Python 3.0. PEP 3000(1) describes the development process for Python 3.0. Start with PEP 3100(2) that describes the general goals for Python 3.0, and then explore the higher-numbered PEPS that propose specific features. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3000 (2) https://www.python.org/dev/peps/pep-3100  File: python.info, Node: Changes to the Development Process, Next: PEP 343 The ‘with’ statement, Prev: Python 3 0, Up: What’s New in Python 2 6 1.11.2 Changes to the Development Process ----------------------------------------- While 2.6 was being developed, the Python development process underwent two significant changes: we switched from SourceForge’s issue tracker to a customized Roundup installation, and the documentation was converted from LaTeX to reStructuredText. * Menu: * New Issue Tracker; Roundup: New Issue Tracker Roundup. * New Documentation Format; reStructuredText Using Sphinx: New Documentation Format reStructuredText Using Sphinx.  File: python.info, Node: New Issue Tracker Roundup, Next: New Documentation Format reStructuredText Using Sphinx, Up: Changes to the Development Process 1.11.2.1 New Issue Tracker: Roundup ................................... For a long time, the Python developers had been growing increasingly annoyed by SourceForge’s bug tracker. SourceForge’s hosted solution doesn’t permit much customization; for example, it wasn’t possible to customize the life cycle of issues. The infrastructure committee of the Python Software Foundation therefore posted a call for issue trackers, asking volunteers to set up different products and import some of the bugs and patches from SourceForge. Four different trackers were examined: Jira(1), Launchpad(2), Roundup(3), and Trac(4). The committee eventually settled on Jira and Roundup as the two candidates. Jira is a commercial product that offers no-cost hosted instances to free-software projects; Roundup is an open-source project that requires volunteers to administer it and a server to host it. After posting a call for volunteers, a new Roundup installation was set up at ‘https://bugs.python.org’. One installation of Roundup can host multiple trackers, and this server now also hosts issue trackers for Jython and for the Python web site. It will surely find other uses in the future. Where possible, this edition of “What’s New in Python” links to the bug/patch item for each change. Hosting of the Python bug tracker is kindly provided by Upfront Systems(5) of Stellenbosch, South Africa. Martin von Löwis put a lot of effort into importing existing bugs and patches from SourceForge; his scripts for this import operation are at ‘http://svn.python.org/view/tracker/importer/’ and may be useful to other projects wishing to move from SourceForge to Roundup. See also ........ ‘https://bugs.python.org’ The Python bug tracker. ‘http://bugs.jython.org’: The Jython bug tracker. ‘http://roundup.sourceforge.net/’ Roundup downloads and documentation. ‘http://svn.python.org/view/tracker/importer/’ Martin von Löwis’s conversion scripts. ---------- Footnotes ---------- (1) https://www.atlassian.com/software/jira/ (2) https://launchpad.net/ (3) http://roundup.sourceforge.net/ (4) https://trac.edgewall.org/ (5) http://www.upfrontsoftware.co.za  File: python.info, Node: New Documentation Format reStructuredText Using Sphinx, Prev: New Issue Tracker Roundup, Up: Changes to the Development Process 1.11.2.2 New Documentation Format: reStructuredText Using Sphinx ................................................................ The Python documentation was written using LaTeX since the project started around 1989. In the 1980s and early 1990s, most documentation was printed out for later study, not viewed online. LaTeX was widely used because it provided attractive printed output while remaining straightforward to write once the basic rules of the markup were learned. Today LaTeX is still used for writing publications destined for printing, but the landscape for programming tools has shifted. We no longer print out reams of documentation; instead, we browse through it online and HTML has become the most important format to support. Unfortunately, converting LaTeX to HTML is fairly complicated and Fred L. Drake Jr., the long-time Python documentation editor, spent a lot of time maintaining the conversion process. Occasionally people would suggest converting the documentation into SGML and later XML, but performing a good conversion is a major task and no one ever committed the time required to finish the job. During the 2.6 development cycle, Georg Brandl put a lot of effort into building a new toolchain for processing the documentation. The resulting package is called Sphinx, and is available from ‘http://sphinx-doc.org/’. Sphinx concentrates on HTML output, producing attractively styled and modern HTML; printed output is still supported through conversion to LaTeX. The input format is reStructuredText, a markup syntax supporting custom extensions and directives that is commonly used in the Python community. Sphinx is a standalone package that can be used for writing, and almost two dozen other projects (listed on the Sphinx web site(1)) have adopted Sphinx as their documentation tool. See also ........ Documenting Python(2) Describes how to write for Python’s documentation. Sphinx(3) Documentation and code for the Sphinx toolchain. Docutils(4) The underlying reStructuredText parser and toolset. ---------- Footnotes ---------- (1) https://www.sphinx-doc.org/en/master/examples.html (2) https://devguide.python.org/documenting/ (3) http://sphinx-doc.org/ (4) http://docutils.sourceforge.net  File: python.info, Node: PEP 343 The ‘with’ statement, Next: PEP 366 Explicit Relative Imports From a Main Module, Prev: Changes to the Development Process, Up: What’s New in Python 2 6 1.11.3 PEP 343: The ‘with’ statement ------------------------------------ The previous version, Python 2.5, added the ‘*note with: 6e9.’ statement as an optional feature, to be enabled by a ‘from __future__ import with_statement’ directive. In 2.6 the statement no longer needs to be specially enabled; this means that ‘with’ is now always a keyword. The rest of this section is a copy of the corresponding section from the “What’s New in Python 2.5” document; if you’re familiar with the ‘‘with’’ statement from Python 2.5, you can skip this section. The ‘*note with: 6e9.’ statement clarifies code that previously would use ‘try...finally’ blocks to ensure that clean-up code is executed. In this section, I’ll discuss the statement as it will commonly be used. In the next section, I’ll examine the implementation details and show how to write objects for use with this statement. The ‘*note with: 6e9.’ statement is a control-flow structure whose basic structure is: with expression [as variable]: with-block The expression is evaluated, and it should result in an object that supports the context management protocol (that is, has *note __enter__(): c95. and *note __exit__(): c96. methods). The object’s *note __enter__(): c95. is called before `with-block' is executed and therefore can run set-up code. It also may return a value that is bound to the name `variable', if given. (Note carefully that `variable' is `not' assigned the result of `expression'.) After execution of the `with-block' is finished, the object’s *note __exit__(): c96. method is called, even if the block raised an exception, and can therefore run clean-up code. Some standard Python objects now support the context management protocol and can be used with the ‘*note with: 6e9.’ statement. File objects are one example: with open('/etc/passwd', 'r') as f: for line in f: print line ... more processing code ... After this statement has executed, the file object in `f' will have been automatically closed, even if the *note for: c30. loop raised an exception part-way through the block. Note: In this case, `f' is the same object created by *note open(): 4f0, because ‘file.__enter__()’ returns `self'. The *note threading: 109. module’s locks and condition variables also support the ‘*note with: 6e9.’ statement: lock = threading.Lock() with lock: # Critical section of code ... The lock is acquired before the block is executed and always released once the block is complete. The ‘localcontext()’ function in the *note decimal: 36. module makes it easy to save and restore the current decimal context, which encapsulates the desired precision and rounding characteristics for computations: from decimal import Decimal, Context, localcontext # Displays with default precision of 28 digits v = Decimal('578') print v.sqrt() with localcontext(Context(prec=16)): # All code in this block uses a precision of 16 digits. # The original context is restored on exiting the block. print v.sqrt() * Menu: * Writing Context Managers:: * The contextlib module::  File: python.info, Node: Writing Context Managers, Next: The contextlib module, Up: PEP 343 The ‘with’ statement 1.11.3.1 Writing Context Managers ................................. Under the hood, the ‘*note with: 6e9.’ statement is fairly complicated. Most people will only use ‘‘with’’ in company with existing objects and don’t need to know these details, so you can skip the rest of this section if you like. Authors of new objects will need to understand the details of the underlying implementation and should keep reading. A high-level explanation of the context management protocol is: * The expression is evaluated and should result in an object called a “context manager”. The context manager must have *note __enter__(): c95. and *note __exit__(): c96. methods. * The context manager’s *note __enter__(): c95. method is called. The value returned is assigned to `VAR'. If no ‘as VAR’ clause is present, the value is simply discarded. * The code in `BLOCK' is executed. * If `BLOCK' raises an exception, the context manager’s *note __exit__(): c96. method is called with three arguments, the exception details (‘type, value, traceback’, the same values returned by *note sys.exc_info(): c5f, which can also be ‘None’ if no exception occurred). The method’s return value controls whether an exception is re-raised: any false value re-raises the exception, and ‘True’ will result in suppressing it. You’ll only rarely want to suppress the exception, because if you do the author of the code containing the ‘*note with: 6e9.’ statement will never realize anything went wrong. * If `BLOCK' didn’t raise an exception, the *note __exit__(): c96. method is still called, but `type', `value', and `traceback' are all ‘None’. Let’s think through an example. I won’t present detailed code but will only sketch the methods necessary for a database that supports transactions. (For people unfamiliar with database terminology: a set of changes to the database are grouped into a transaction. Transactions can be either committed, meaning that all the changes are written into the database, or rolled back, meaning that the changes are all discarded and the database is unchanged. See any database textbook for more information.) Let’s assume there’s an object representing a database connection. Our goal will be to let the user write code like this: db_connection = DatabaseConnection() with db_connection as cursor: cursor.execute('insert into ...') cursor.execute('delete from ...') # ... more operations ... The transaction should be committed if the code in the block runs flawlessly or rolled back if there’s an exception. Here’s the basic interface for ‘DatabaseConnection’ that I’ll assume: class DatabaseConnection: # Database interface def cursor(self): "Returns a cursor object and starts a new transaction" def commit(self): "Commits current transaction" def rollback(self): "Rolls back current transaction" The *note __enter__(): c95. method is pretty easy, having only to start a new transaction. For this application the resulting cursor object would be a useful result, so the method will return it. The user can then add ‘as cursor’ to their ‘*note with: 6e9.’ statement to bind the cursor to a variable name. class DatabaseConnection: ... def __enter__(self): # Code to start a new transaction cursor = self.cursor() return cursor The *note __exit__(): c96. method is the most complicated because it’s where most of the work has to be done. The method has to check if an exception occurred. If there was no exception, the transaction is committed. The transaction is rolled back if there was an exception. In the code below, execution will just fall off the end of the function, returning the default value of ‘None’. ‘None’ is false, so the exception will be re-raised automatically. If you wished, you could be more explicit and add a *note return: 190. statement at the marked location. class DatabaseConnection: ... def __exit__(self, type, value, tb): if tb is None: # No exception, so commit self.commit() else: # Exception occurred, so rollback. self.rollback() # return False  File: python.info, Node: The contextlib module, Prev: Writing Context Managers, Up: PEP 343 The ‘with’ statement 1.11.3.2 The contextlib module .............................. The *note contextlib: 24. module provides some functions and a decorator that are useful when writing objects for use with the ‘*note with: 6e9.’ statement. The decorator is called ‘contextmanager()’, and lets you write a single generator function instead of defining a new class. The generator should yield exactly one value. The code up to the *note yield: 18f. will be executed as the *note __enter__(): c95. method, and the value yielded will be the method’s return value that will get bound to the variable in the ‘*note with: 6e9.’ statement’s ‘as’ clause, if any. The code after the ‘yield’ will be executed in the *note __exit__(): c96. method. Any exception raised in the block will be raised by the ‘yield’ statement. Using this decorator, our database example from the previous section could be written as: from contextlib import contextmanager @contextmanager def db_transaction(connection): cursor = connection.cursor() try: yield cursor except: connection.rollback() raise else: connection.commit() db = DatabaseConnection() with db_transaction(db) as cursor: ... The *note contextlib: 24. module also has a ‘nested(mgr1, mgr2, ...)’ function that combines a number of context managers so you don’t need to write nested ‘*note with: 6e9.’ statements. In this example, the single ‘‘with’’ statement both starts a database transaction and acquires a thread lock: lock = threading.Lock() with nested (db_transaction(db), lock) as (cursor, locked): ... Finally, the ‘closing()’ function returns its argument so that it can be bound to a variable, and calls the argument’s ‘.close()’ method at the end of the block. import urllib, sys from contextlib import closing with closing(urllib.urlopen('http://www.yahoo.com')) as f: for line in f: sys.stdout.write(line) See also ........ PEP 343(1) - The “with” statement PEP written by Guido van Rossum and Nick Coghlan; implemented by Mike Bland, Guido van Rossum, and Neal Norwitz. The PEP shows the code generated for a ‘*note with: 6e9.’ statement, which can be helpful in learning how the statement works. The documentation for the *note contextlib: 24. module. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0343  File: python.info, Node: PEP 366 Explicit Relative Imports From a Main Module, Next: PEP 370 Per-user site-packages Directory, Prev: PEP 343 The ‘with’ statement, Up: What’s New in Python 2 6 1.11.4 PEP 366: Explicit Relative Imports From a Main Module ------------------------------------------------------------ Python’s *note -m: 337. switch allows running a module as a script. When you ran a module that was located inside a package, relative imports didn’t work correctly. The fix for Python 2.6 adds a *note __package__: 955. attribute to modules. When this attribute is present, relative imports will be relative to the value of this attribute instead of the *note __name__: d12. attribute. PEP 302-style importers can then set *note __package__: 955. as necessary. The *note runpy: e2. module that implements the *note -m: 337. switch now does this, so relative imports will now work correctly in scripts running from inside a package.  File: python.info, Node: PEP 370 Per-user site-packages Directory, Next: PEP 371 The multiprocessing Package, Prev: PEP 366 Explicit Relative Imports From a Main Module, Up: What’s New in Python 2 6 1.11.5 PEP 370: Per-user ‘site-packages’ Directory -------------------------------------------------- When you run Python, the module search path ‘sys.path’ usually includes a directory whose path ends in ‘"site-packages"’. This directory is intended to hold locally-installed packages available to all users using a machine or a particular site installation. Python 2.6 introduces a convention for user-specific site directories. The directory varies depending on the platform: * Unix and Mac OS X: ‘~/.local/’ * Windows: ‘%APPDATA%/Python’ Within this directory, there will be version-specific subdirectories, such as ‘lib/python2.6/site-packages’ on Unix/Mac OS and ‘Python26/site-packages’ on Windows. If you don’t like the default directory, it can be overridden by an environment variable. *note PYTHONUSERBASE: d14. sets the root directory used for all Python versions supporting this feature. On Windows, the directory for application-specific data can be changed by setting the ‘APPDATA’ environment variable. You can also modify the ‘site.py’ file for your Python installation. The feature can be disabled entirely by running Python with the *note -s: d15. option or setting the *note PYTHONNOUSERSITE: d16. environment variable. See also ........ PEP 370(1) - Per-user ‘site-packages’ Directory PEP written and implemented by Christian Heimes. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0370  File: python.info, Node: PEP 371 The multiprocessing Package, Next: PEP 3101 Advanced String Formatting, Prev: PEP 370 Per-user site-packages Directory, Up: What’s New in Python 2 6 1.11.6 PEP 371: The ‘multiprocessing’ Package --------------------------------------------- The new *note multiprocessing: b7. package lets Python programs create new processes that will perform a computation and return a result to the parent. The parent and child processes can communicate using queues and pipes, synchronize their operations using locks and semaphores, and can share simple arrays of data. The *note multiprocessing: b7. module started out as an exact emulation of the *note threading: 109. module using processes instead of threads. That goal was discarded along the path to Python 2.6, but the general approach of the module is still similar. The fundamental class is the ‘Process’, which is passed a callable object and a collection of arguments. The ‘start()’ method sets the callable running in a subprocess, after which you can call the ‘is_alive()’ method to check whether the subprocess is still running and the ‘join()’ method to wait for the process to exit. Here’s a simple example where the subprocess will calculate a factorial. The function doing the calculation is written strangely so that it takes significantly longer when the input argument is a multiple of 4. import time from multiprocessing import Process, Queue def factorial(queue, N): "Compute a factorial." # If N is a multiple of 4, this function will take much longer. if (N % 4) == 0: time.sleep(.05 * N/4) # Calculate the result fact = 1L for i in range(1, N+1): fact = fact * i # Put the result on the queue queue.put(fact) if __name__ == '__main__': queue = Queue() N = 5 p = Process(target=factorial, args=(queue, N)) p.start() p.join() result = queue.get() print 'Factorial', N, '=', result A *note Queue: d18. is used to communicate the result of the factorial. The *note Queue: d18. object is stored in a global variable. The child process will use the value of the variable when the child was created; because it’s a *note Queue: d18, parent and child can use the object to communicate. (If the parent were to change the value of the global variable, the child’s value would be unaffected, and vice versa.) Two other classes, ‘Pool’ and ‘Manager’, provide higher-level interfaces. ‘Pool’ will create a fixed number of worker processes, and requests can then be distributed to the workers by calling ‘apply()’ or ‘apply_async()’ to add a single request, and *note map(): c2d. or ‘map_async()’ to add a number of requests. The following code uses a ‘Pool’ to spread requests across 5 worker processes and retrieve a list of results: from multiprocessing import Pool def factorial(N, dictionary): "Compute a factorial." ... p = Pool(5) result = p.map(factorial, range(1, 1000, 10)) for v in result: print v This produces the following output: 1 39916800 51090942171709440000 8222838654177922817725562880000000 33452526613163807108170062053440751665152000000000 ... The other high-level interface, the ‘Manager’ class, creates a separate server process that can hold master copies of Python data structures. Other processes can then access and modify these data structures using proxy objects. The following example creates a shared dictionary by calling the *note dict(): 1b8. method; the worker processes then insert values into the dictionary. (Locking is not done for you automatically, which doesn’t matter in this example. ‘Manager’’s methods also include ‘Lock()’, ‘RLock()’, and ‘Semaphore()’ to create shared locks.) import time from multiprocessing import Pool, Manager def factorial(N, dictionary): "Compute a factorial." # Calculate the result fact = 1L for i in range(1, N+1): fact = fact * i # Store result in dictionary dictionary[N] = fact if __name__ == '__main__': p = Pool(5) mgr = Manager() d = mgr.dict() # Create shared dictionary # Run tasks using the pool for N in range(1, 1000, 10): p.apply_async(factorial, (N, d)) # Mark pool as closed -- no more tasks can be added. p.close() # Wait for tasks to exit p.join() # Output results for k, v in sorted(d.items()): print k, v This will produce the output: 1 1 11 39916800 21 51090942171709440000 31 8222838654177922817725562880000000 41 33452526613163807108170062053440751665152000000000 51 15511187532873822802242430164693032110632597200169861120000... See also ........ The documentation for the *note multiprocessing: b7. module. PEP 371(1) - Addition of the multiprocessing package PEP written by Jesse Noller and Richard Oudkerk; implemented by Richard Oudkerk and Jesse Noller. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0371  File: python.info, Node: PEP 3101 Advanced String Formatting, Next: PEP 3105 print As a Function, Prev: PEP 371 The multiprocessing Package, Up: What’s New in Python 2 6 1.11.7 PEP 3101: Advanced String Formatting ------------------------------------------- In Python 3.0, the ‘%’ operator is supplemented by a more powerful string formatting method, *note format(): 4db. Support for the *note str.format(): 4da. method has been backported to Python 2.6. In 2.6, both 8-bit and Unicode strings have a ‘.format()’ method that treats the string as a template and takes the arguments to be formatted. The formatting template uses curly brackets (‘{’, ‘}’) as special characters: >>> # Substitute positional argument 0 into the string. >>> "User ID: {0}".format("root") 'User ID: root' >>> # Use the named keyword arguments >>> "User ID: {uid} Last seen: {last_login}".format( ... uid="root", ... last_login = "5 Mar 2008 07:20") 'User ID: root Last seen: 5 Mar 2008 07:20' Curly brackets can be escaped by doubling them: >>> "Empty dict: {{}}".format() "Empty dict: {}" Field names can be integers indicating positional arguments, such as ‘{0}’, ‘{1}’, etc. or names of keyword arguments. You can also supply compound field names that read attributes or access dictionary keys: >>> import sys >>> print 'Platform: {0.platform}\nPython version: {0.version}'.format(sys) Platform: darwin Python version: 2.6a1+ (trunk:61261M, Mar 5 2008, 20:29:41) [GCC 4.0.1 (Apple Computer, Inc. build 5367)]' >>> import mimetypes >>> 'Content-type: {0[.mp4]}'.format(mimetypes.types_map) 'Content-type: video/mp4' Note that when using dictionary-style notation such as ‘[.mp4]’, you don’t need to put any quotation marks around the string; it will look up the value using ‘.mp4’ as the key. Strings beginning with a number will be converted to an integer. You can’t write more complicated expressions inside a format string. So far we’ve shown how to specify which field to substitute into the resulting string. The precise formatting used is also controllable by adding a colon followed by a format specifier. For example: >>> # Field 0: left justify, pad to 15 characters >>> # Field 1: right justify, pad to 6 characters >>> fmt = '{0:15} ${1:>6}' >>> fmt.format('Registration', 35) 'Registration $ 35' >>> fmt.format('Tutorial', 50) 'Tutorial $ 50' >>> fmt.format('Banquet', 125) 'Banquet $ 125' Format specifiers can reference other fields through nesting: >>> fmt = '{0:{1}}' >>> width = 15 >>> fmt.format('Invoice #1234', width) 'Invoice #1234 ' >>> width = 35 >>> fmt.format('Invoice #1234', width) 'Invoice #1234 ' The alignment of a field within the desired width can be specified: Character Effect ---------------------------------------------------------------------- < (default) Left-align > Right-align ^ Center = (For numeric types only) Pad after the sign. Format specifiers can also include a presentation type, which controls how the value is formatted. For example, floating-point numbers can be formatted as a general number or in exponential notation: >>> '{0:g}'.format(3.75) '3.75' >>> '{0:e}'.format(3.75) '3.750000e+00' A variety of presentation types are available. Consult the 2.6 documentation for a *note complete list: d1a.; here’s a sample: ‘b’ Binary. Outputs the number in base 2. ‘c’ Character. Converts the integer to the corresponding Unicode character before printing. ‘d’ Decimal Integer. Outputs the number in base 10. ‘o’ Octal format. Outputs the number in base 8. ‘x’ Hex format. Outputs the number in base 16, using lower-case letters for the digits above 9. ‘e’ Exponent notation. Prints the number in scientific notation using the letter ‘e’ to indicate the exponent. ‘g’ General format. This prints the number as a fixed-point number, unless the number is too large, in which case it switches to ‘e’ exponent notation. ‘n’ Number. This is the same as ‘g’ (for floats) or ‘d’ (for integers), except that it uses the current locale setting to insert the appropriate number separator characters. ‘%’ Percentage. Multiplies the number by 100 and displays in fixed (‘f’) format, followed by a percent sign. Classes and types can define a *note __format__(): 94e. method to control how they’re formatted. It receives a single argument, the format specifier: def __format__(self, format_spec): if isinstance(format_spec, unicode): return unicode(str(self)) else: return str(self) There’s also a *note format(): 4db. builtin that will format a single value. It calls the type’s *note __format__(): 94e. method with the provided specifier: >>> format(75.6564, '.2f') '75.66' See also ........ *note Format String Syntax: d1a. The reference documentation for format fields. PEP 3101(1) - Advanced String Formatting PEP written by Talin. Implemented by Eric Smith. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3101  File: python.info, Node: PEP 3105 print As a Function, Next: PEP 3110 Exception-Handling Changes, Prev: PEP 3101 Advanced String Formatting, Up: What’s New in Python 2 6 1.11.8 PEP 3105: ‘print’ As a Function -------------------------------------- The ‘print’ statement becomes the *note print(): 886. function in Python 3.0. Making *note print(): 886. a function makes it possible to replace the function by doing ‘def print(...)’ or importing a new function from somewhere else. Python 2.6 has a ‘__future__’ import that removes ‘print’ as language syntax, letting you use the functional form instead. For example: >>> from __future__ import print_function >>> print('# of entries', len(dictionary), file=sys.stderr) The signature of the new function is: def print(*args, sep=' ', end='\n', file=None) The parameters are: * `args': positional arguments whose values will be printed out. * `sep': the separator, which will be printed between arguments. * `end': the ending text, which will be printed after all of the arguments have been output. * `file': the file object to which the output will be sent. See also ........ PEP 3105(1) - Make print a function PEP written by Georg Brandl. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3105  File: python.info, Node: PEP 3110 Exception-Handling Changes, Next: PEP 3112 Byte Literals, Prev: PEP 3105 print As a Function, Up: What’s New in Python 2 6 1.11.9 PEP 3110: Exception-Handling Changes ------------------------------------------- One error that Python programmers occasionally make is writing the following code: try: ... except TypeError, ValueError: # Wrong! ... The author is probably trying to catch both *note TypeError: 192. and *note ValueError: 1fb. exceptions, but this code actually does something different: it will catch *note TypeError: 192. and bind the resulting exception object to the local name ‘"ValueError"’. The *note ValueError: 1fb. exception will not be caught at all. The correct code specifies a tuple of exceptions: try: ... except (TypeError, ValueError): ... This error happens because the use of the comma here is ambiguous: does it indicate two different nodes in the parse tree, or a single node that’s a tuple? Python 3.0 makes this unambiguous by replacing the comma with the word “as”. To catch an exception and store the exception object in the variable ‘exc’, you must write: try: ... except TypeError as exc: ... Python 3.0 will only support the use of “as”, and therefore interprets the first example as catching two different exceptions. Python 2.6 supports both the comma and “as”, so existing code will continue to work. We therefore suggest using “as” when writing new Python code that will only be executed with 2.6. See also ........ PEP 3110(1) - Catching Exceptions in Python 3000 PEP written and implemented by Collin Winter. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3110  File: python.info, Node: PEP 3112 Byte Literals, Next: PEP 3116 New I/O Library, Prev: PEP 3110 Exception-Handling Changes, Up: What’s New in Python 2 6 1.11.10 PEP 3112: Byte Literals ------------------------------- Python 3.0 adopts Unicode as the language’s fundamental string type and denotes 8-bit literals differently, either as ‘b'string'’ or using a *note bytes: 331. constructor. For future compatibility, Python 2.6 adds *note bytes: 331. as a synonym for the *note str: 330. type, and it also supports the ‘b''’ notation. The 2.6 *note str: 330. differs from 3.0’s *note bytes: 331. type in various ways; most notably, the constructor is completely different. In 3.0, ‘bytes([65, 66, 67])’ is 3 elements long, containing the bytes representing ‘ABC’; in 2.6, ‘bytes([65, 66, 67])’ returns the 12-byte string representing the *note str(): 330. of the list. The primary use of *note bytes: 331. in 2.6 will be to write tests of object type such as ‘isinstance(x, bytes)’. This will help the 2to3 converter, which can’t tell whether 2.x code intends strings to contain either characters or 8-bit bytes; you can now use either *note bytes: 331. or *note str: 330. to represent your intention exactly, and the resulting code will also be correct in Python 3.0. There’s also a ‘__future__’ import that causes all string literals to become Unicode strings. This means that ‘\u’ escape sequences can be used to include Unicode characters: from __future__ import unicode_literals s = ('\u751f\u3080\u304e\u3000\u751f\u3054' '\u3081\u3000\u751f\u305f\u307e\u3054') print len(s) # 12 Unicode characters At the C level, Python 3.0 will rename the existing 8-bit string type, called ‘PyStringObject’ in Python 2.x, to *note PyBytesObject: d1e. Python 2.6 uses ‘#define’ to support using the names *note PyBytesObject(): d1e, *note PyBytes_Check(): d1f, *note PyBytes_FromStringAndSize(): d20, and all the other functions and macros used with strings. Instances of the *note bytes: 331. type are immutable just as strings are. A new *note bytearray: 332. type stores a mutable sequence of bytes: >>> bytearray([65, 66, 67]) bytearray(b'ABC') >>> b = bytearray(u'\u21ef\u3244', 'utf-8') >>> b bytearray(b'\xe2\x87\xaf\xe3\x89\x84') >>> b[0] = '\xe3' >>> b bytearray(b'\xe3\x87\xaf\xe3\x89\x84') >>> unicode(str(b), 'utf-8') u'\u31ef \u3244' Byte arrays support most of the methods of string types, such as ‘startswith()’/‘endswith()’, ‘find()’/‘rfind()’, and some of the methods of lists, such as ‘append()’, ‘pop()’, and ‘reverse()’. >>> b = bytearray('ABC') >>> b.append('d') >>> b.append(ord('e')) >>> b bytearray(b'ABCde') There’s also a corresponding C API, with *note PyByteArray_FromObject(): d21, *note PyByteArray_FromStringAndSize(): d22, and various other functions. See also ........ PEP 3112(1) - Bytes literals in Python 3000 PEP written by Jason Orendorff; backported to 2.6 by Christian Heimes. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3112  File: python.info, Node: PEP 3116 New I/O Library, Next: PEP 3118 Revised Buffer Protocol, Prev: PEP 3112 Byte Literals, Up: What’s New in Python 2 6 1.11.11 PEP 3116: New I/O Library --------------------------------- Python’s built-in file objects support a number of methods, but file-like objects don’t necessarily support all of them. Objects that imitate files usually support ‘read()’ and ‘write()’, but they may not support *note readline(): de, for example. Python 3.0 introduces a layered I/O library in the *note io: a1. module that separates buffering and text-handling features from the fundamental read and write operations. There are three levels of abstract base classes provided by the *note io: a1. module: * ‘RawIOBase’ defines raw I/O operations: ‘read()’, ‘readinto()’, ‘write()’, ‘seek()’, ‘tell()’, ‘truncate()’, and ‘close()’. Most of the methods of this class will often map to a single system call. There are also ‘readable()’, ‘writable()’, and ‘seekable()’ methods for determining what operations a given object will allow. Python 3.0 has concrete implementations of this class for files and sockets, but Python 2.6 hasn’t restructured its file and socket objects in this way. * ‘BufferedIOBase’ is an abstract base class that buffers data in memory to reduce the number of system calls used, making I/O processing more efficient. It supports all of the methods of ‘RawIOBase’, and adds a ‘raw’ attribute holding the underlying raw object. There are five concrete classes implementing this ABC. ‘BufferedWriter’ and ‘BufferedReader’ are for objects that support write-only or read-only usage that have a ‘seek()’ method for random access. ‘BufferedRandom’ objects support read and write access upon the same underlying stream, and ‘BufferedRWPair’ is for objects such as TTYs that have both read and write operations acting upon unconnected streams of data. The ‘BytesIO’ class supports reading, writing, and seeking over an in-memory buffer. * ‘TextIOBase’: Provides functions for reading and writing strings (remember, strings will be Unicode in Python 3.0), and supporting *note universal newlines: 5f4. ‘TextIOBase’ defines the *note readline(): de. method and supports iteration upon objects. There are two concrete implementations. ‘TextIOWrapper’ wraps a buffered I/O object, supporting all of the methods for text I/O and adding a ‘buffer’ attribute for access to the underlying object. ‘StringIO’ simply buffers everything in memory without ever writing anything to disk. (In Python 2.6, *note io.StringIO: 82d. is implemented in pure Python, so it’s pretty slow. You should therefore stick with the existing ‘StringIO’ module or ‘cStringIO’ for now. At some point Python 3.0’s *note io: a1. module will be rewritten into C for speed, and perhaps the C implementation will be backported to the 2.x releases.) In Python 2.6, the underlying implementations haven’t been restructured to build on top of the *note io: a1. module’s classes. The module is being provided to make it easier to write code that’s forward-compatible with 3.0, and to save developers the effort of writing their own implementations of buffering and text I/O. See also ........ PEP 3116(1) - New I/O PEP written by Daniel Stutzbach, Mike Verdone, and Guido van Rossum. Code by Guido van Rossum, Georg Brandl, Walter Doerwald, Jeremy Hylton, Martin von Löwis, Tony Lownds, and others. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3116  File: python.info, Node: PEP 3118 Revised Buffer Protocol, Next: PEP 3119 Abstract Base Classes, Prev: PEP 3116 New I/O Library, Up: What’s New in Python 2 6 1.11.12 PEP 3118: Revised Buffer Protocol ----------------------------------------- The buffer protocol is a C-level API that lets Python types exchange pointers into their internal representations. A memory-mapped file can be viewed as a buffer of characters, for example, and this lets another module such as *note re: dd. treat memory-mapped files as a string of characters to be searched. The primary users of the buffer protocol are numeric-processing packages such as NumPy, which expose the internal representation of arrays so that callers can write data directly into an array instead of going through a slower API. This PEP updates the buffer protocol in light of experience from NumPy development, adding a number of new features such as indicating the shape of an array or locking a memory region. The most important new C API function is ‘PyObject_GetBuffer(PyObject *obj, Py_buffer *view, int flags)’, which takes an object and a set of flags, and fills in the ‘Py_buffer’ structure with information about the object’s memory representation. Objects can use this operation to lock memory in place while an external caller could be modifying the contents, so there’s a corresponding ‘PyBuffer_Release(Py_buffer *view)’ to indicate that the external caller is done. The `flags' argument to *note PyObject_GetBuffer(): d25. specifies constraints upon the memory returned. Some examples are: * ‘PyBUF_WRITABLE’ indicates that the memory must be writable. * ‘PyBUF_LOCK’ requests a read-only or exclusive lock on the memory. * ‘PyBUF_C_CONTIGUOUS’ and ‘PyBUF_F_CONTIGUOUS’ requests a C-contiguous (last dimension varies the fastest) or Fortran-contiguous (first dimension varies the fastest) array layout. Two new argument codes for *note PyArg_ParseTuple(): 26a, ‘s*’ and ‘z*’, return locked buffer objects for a parameter. See also ........ PEP 3118(1) - Revising the buffer protocol PEP written by Travis Oliphant and Carl Banks; implemented by Travis Oliphant. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3118  File: python.info, Node: PEP 3119 Abstract Base Classes, Next: PEP 3127 Integer Literal Support and Syntax, Prev: PEP 3118 Revised Buffer Protocol, Up: What’s New in Python 2 6 1.11.13 PEP 3119: Abstract Base Classes --------------------------------------- Some object-oriented languages such as Java support interfaces, declaring that a class has a given set of methods or supports a given access protocol. Abstract Base Classes (or ABCs) are an equivalent feature for Python. The ABC support consists of an *note abc: 4. module containing a metaclass called ‘ABCMeta’, special handling of this metaclass by the *note isinstance(): 44f. and *note issubclass(): 450. builtins, and a collection of basic ABCs that the Python developers think will be widely useful. Future versions of Python will probably add more ABCs. Let’s say you have a particular class and wish to know whether it supports dictionary-style access. The phrase “dictionary-style” is vague, however. It probably means that accessing items with ‘obj[1]’ works. Does it imply that setting items with ‘obj[2] = value’ works? Or that the object will have ‘keys()’, ‘values()’, and ‘items()’ methods? What about the iterative variants such as ‘iterkeys()’? *note copy(): 26. and ‘update()’? Iterating over the object with *note iter(): d27.? The Python 2.6 *note collections: 1e. module includes a number of different ABCs that represent these distinctions. ‘Iterable’ indicates that a class defines *note __iter__(): 50f, and ‘Container’ means the class defines a *note __contains__(): d28. method and therefore supports ‘x in y’ expressions. The basic dictionary interface of getting items, setting items, and ‘keys()’, ‘values()’, and ‘items()’, is defined by the ‘MutableMapping’ ABC. You can derive your own classes from a particular ABC to indicate they support that ABC’s interface: import collections class Storage(collections.MutableMapping): ... Alternatively, you could write the class without deriving from the desired ABC and instead register the class by calling the ABC’s ‘register()’ method: import collections class Storage: ... collections.MutableMapping.register(Storage) For classes that you write, deriving from the ABC is probably clearer. The ‘register()’ method is useful when you’ve written a new ABC that can describe an existing type or class, or if you want to declare that some third-party class implements an ABC. For example, if you defined a ‘PrintableType’ ABC, it’s legal to do: # Register Python's types PrintableType.register(int) PrintableType.register(float) PrintableType.register(str) Classes should obey the semantics specified by an ABC, but Python can’t check this; it’s up to the class author to understand the ABC’s requirements and to implement the code accordingly. To check whether an object supports a particular interface, you can now write: def func(d): if not isinstance(d, collections.MutableMapping): raise ValueError("Mapping object expected, not %r" % d) Don’t feel that you must now begin writing lots of checks as in the above example. Python has a strong tradition of duck-typing, where explicit type-checking is never done and code simply calls methods on an object, trusting that those methods will be there and raising an exception if they aren’t. Be judicious in checking for ABCs and only do it where it’s absolutely necessary. You can write your own ABCs by using ‘abc.ABCMeta’ as the metaclass in a class definition: from abc import ABCMeta, abstractmethod class Drawable(): __metaclass__ = ABCMeta @abstractmethod def draw(self, x, y, scale=1.0): pass def draw_doubled(self, x, y): self.draw(x, y, scale=2.0) class Square(Drawable): def draw(self, x, y, scale): ... In the ‘Drawable’ ABC above, the ‘draw_doubled()’ method renders the object at twice its size and can be implemented in terms of other methods described in ‘Drawable’. Classes implementing this ABC therefore don’t need to provide their own implementation of ‘draw_doubled()’, though they can do so. An implementation of ‘draw()’ is necessary, though; the ABC can’t provide a useful generic implementation. You can apply the ‘@abstractmethod’ decorator to methods such as ‘draw()’ that must be implemented; Python will then raise an exception for classes that don’t define the method. Note that the exception is only raised when you actually try to create an instance of a subclass lacking the method: >>> class Circle(Drawable): ... pass ... >>> c = Circle() Traceback (most recent call last): File "", line 1, in TypeError: Can't instantiate abstract class Circle with abstract methods draw >>> Abstract data attributes can be declared using the ‘@abstractproperty’ decorator: from abc import abstractproperty ... @abstractproperty def readonly(self): return self._x Subclasses must then define a ‘readonly()’ property. See also ........ PEP 3119(1) - Introducing Abstract Base Classes PEP written by Guido van Rossum and Talin. Implemented by Guido van Rossum. Backported to 2.6 by Benjamin Aranguren, with Alex Martelli. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3119  File: python.info, Node: PEP 3127 Integer Literal Support and Syntax, Next: PEP 3129 Class Decorators, Prev: PEP 3119 Abstract Base Classes, Up: What’s New in Python 2 6 1.11.14 PEP 3127: Integer Literal Support and Syntax ---------------------------------------------------- Python 3.0 changes the syntax for octal (base-8) integer literals, prefixing them with “0o” or “0O” instead of a leading zero, and adds support for binary (base-2) integer literals, signalled by a “0b” or “0B” prefix. Python 2.6 doesn’t drop support for a leading 0 signalling an octal number, but it does add support for “0o” and “0b”: >>> 0o21, 2*8 + 1 (17, 17) >>> 0b101111 47 The *note oct(): c65. builtin still returns numbers prefixed with a leading zero, and a new *note bin(): c40. builtin returns the binary representation for a number: >>> oct(42) '052' >>> future_builtins.oct(42) '0o52' >>> bin(173) '0b10101101' The *note int(): 184. and ‘long()’ builtins will now accept the “0o” and “0b” prefixes when base-8 or base-2 are requested, or when the `base' argument is zero (signalling that the base used should be determined from the string): >>> int ('0o52', 0) 42 >>> int('1101', 2) 13 >>> int('0b1101', 2) 13 >>> int('0b1101', 0) 13 See also ........ PEP 3127(1) - Integer Literal Support and Syntax PEP written by Patrick Maupin; backported to 2.6 by Eric Smith. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3127  File: python.info, Node: PEP 3129 Class Decorators, Next: PEP 3141 A Type Hierarchy for Numbers, Prev: PEP 3127 Integer Literal Support and Syntax, Up: What’s New in Python 2 6 1.11.15 PEP 3129: Class Decorators ---------------------------------- Decorators have been extended from functions to classes. It’s now legal to write: @foo @bar class A: pass This is equivalent to: class A: pass A = foo(bar(A)) See also ........ PEP 3129(1) - Class Decorators PEP written by Collin Winter. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3129  File: python.info, Node: PEP 3141 A Type Hierarchy for Numbers, Next: Other Language Changes<10>, Prev: PEP 3129 Class Decorators, Up: What’s New in Python 2 6 1.11.16 PEP 3141: A Type Hierarchy for Numbers ---------------------------------------------- Python 3.0 adds several abstract base classes for numeric types inspired by Scheme’s numeric tower. These classes were backported to 2.6 as the *note numbers: c1. module. The most general ABC is ‘Number’. It defines no operations at all, and only exists to allow checking if an object is a number by doing ‘isinstance(obj, Number)’. ‘Complex’ is a subclass of ‘Number’. Complex numbers can undergo the basic operations of addition, subtraction, multiplication, division, and exponentiation, and you can retrieve the real and imaginary parts and obtain a number’s conjugate. Python’s built-in complex type is an implementation of ‘Complex’. ‘Real’ further derives from ‘Complex’, and adds operations that only work on real numbers: ‘floor()’, ‘trunc()’, rounding, taking the remainder mod N, floor division, and comparisons. ‘Rational’ numbers derive from ‘Real’, have ‘numerator’ and ‘denominator’ properties, and can be converted to floats. Python 2.6 adds a simple rational-number class, ‘Fraction’, in the *note fractions: 83. module. (It’s called ‘Fraction’ instead of ‘Rational’ to avoid a name clash with *note numbers.Rational: c58.) ‘Integral’ numbers derive from ‘Rational’, and can be shifted left and right with ‘<<’ and ‘>>’, combined using bitwise operations such as ‘&’ and ‘|’, and can be used as array indexes and slice boundaries. In Python 3.0, the PEP slightly redefines the existing builtins *note round(): c6d, *note math.floor(): d2c, *note math.ceil(): d2d, and adds a new one, *note math.trunc(): d2e, that’s been backported to Python 2.6. *note math.trunc(): d2e. rounds toward zero, returning the closest ‘Integral’ that’s between the function’s argument and zero. See also ........ PEP 3141(1) - A Type Hierarchy for Numbers PEP written by Jeffrey Yasskin. Scheme’s numerical tower(2), from the Guile manual. Scheme’s number datatypes(3) from the R5RS Scheme specification. * Menu: * The fractions Module:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3141 (2) https://www.gnu.org/software/guile/manual/html_node/Numerical-Tower.html#Numerical-Tower (3) http://schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%_sec_6.2  File: python.info, Node: The fractions Module, Up: PEP 3141 A Type Hierarchy for Numbers 1.11.16.1 The ‘fractions’ Module ................................ To fill out the hierarchy of numeric types, the *note fractions: 83. module provides a rational-number class. Rational numbers store their values as a numerator and denominator forming a fraction, and can exactly represent numbers such as ‘2/3’ that floating-point numbers can only approximate. The ‘Fraction’ constructor takes two ‘Integral’ values that will be the numerator and denominator of the resulting fraction. >>> from fractions import Fraction >>> a = Fraction(2, 3) >>> b = Fraction(2, 5) >>> float(a), float(b) (0.66666666666666663, 0.40000000000000002) >>> a+b Fraction(16, 15) >>> a/b Fraction(5, 3) For converting floating-point numbers to rationals, the float type now has an ‘as_integer_ratio()’ method that returns the numerator and denominator for a fraction that evaluates to the same floating-point value: >>> (2.5) .as_integer_ratio() (5, 2) >>> (3.1415) .as_integer_ratio() (7074029114692207L, 2251799813685248L) >>> (1./3) .as_integer_ratio() (6004799503160661L, 18014398509481984L) Note that values that can only be approximated by floating-point numbers, such as 1./3, are not simplified to the number being approximated; the fraction attempts to match the floating-point value `exactly'. The *note fractions: 83. module is based upon an implementation by Sjoerd Mullender that was in Python’s ‘Demo/classes/’ directory for a long time. This implementation was significantly updated by Jeffrey Yasskin.  File: python.info, Node: Other Language Changes<10>, Next: New and Improved Modules<2>, Prev: PEP 3141 A Type Hierarchy for Numbers, Up: What’s New in Python 2 6 1.11.17 Other Language Changes ------------------------------ Some smaller changes made to the core Python language are: * Directories and zip archives containing a ‘__main__.py’ file can now be executed directly by passing their name to the interpreter. The directory or zip archive is automatically inserted as the first entry in sys.path. (Suggestion and initial patch by Andy Chu, subsequently revised by Phillip J. Eby and Nick Coghlan; bpo-1739468(1).) * The *note hasattr(): 447. function was catching and ignoring all errors, under the assumption that they meant a *note __getattr__(): 31a. method was failing somehow and the return value of *note hasattr(): 447. would therefore be ‘False’. This logic shouldn’t be applied to *note KeyboardInterrupt: 197. and *note SystemExit: 5fc, however; Python 2.6 will no longer discard such exceptions when *note hasattr(): 447. encounters them. (Fixed by Benjamin Peterson; bpo-2196(2).) * When calling a function using the ‘**’ syntax to provide keyword arguments, you are no longer required to use a Python dictionary; any mapping will now work: >>> def f(**kw): ... print sorted(kw) ... >>> ud=UserDict.UserDict() >>> ud['a'] = 1 >>> ud['b'] = 'string' >>> f(**ud) ['a', 'b'] (Contributed by Alexander Belopolsky; bpo-1686487(3).) It’s also become legal to provide keyword arguments after a ‘*args’ argument to a function call. >>> def f(*args, **kw): ... print args, kw ... >>> f(1,2,3, *(4,5,6), keyword=13) (1, 2, 3, 4, 5, 6) {'keyword': 13} Previously this would have been a syntax error. (Contributed by Amaury Forgeot d’Arc; bpo-3473(4).) * A new builtin, ‘next(iterator, [default])’ returns the next item from the specified iterator. If the `default' argument is supplied, it will be returned if `iterator' has been exhausted; otherwise, the *note StopIteration: 486. exception will be raised. (Backported in bpo-2719(5).) * Tuples now have ‘index()’ and ‘count()’ methods matching the list type’s ‘index()’ and ‘count()’ methods: >>> t = (0,1,2,3,4,0,1,2) >>> t.index(3) 3 >>> t.count(0) 2 (Contributed by Raymond Hettinger) * The built-in types now have improved support for extended slicing syntax, accepting various combinations of ‘(start, stop, step)’. Previously, the support was partial and certain corner cases wouldn’t work. (Implemented by Thomas Wouters.) * Properties now have three attributes, ‘getter’, ‘setter’ and ‘deleter’, that are decorators providing useful shortcuts for adding a getter, setter or deleter function to an existing property. You would use them like this: class C(object): @property def x(self): return self._x @x.setter def x(self, value): self._x = value @x.deleter def x(self): del self._x class D(C): @C.x.getter def x(self): return self._x * 2 @x.setter def x(self, value): self._x = value / 2 * Several methods of the built-in set types now accept multiple iterables: ‘intersection()’, ‘intersection_update()’, ‘union()’, ‘update()’, ‘difference()’ and ‘difference_update()’. >>> s=set('1234567890') >>> s.intersection('abc123', 'cdf246') # Intersection between all inputs set(['2']) >>> s.difference('246', '789') set(['1', '0', '3', '5']) (Contributed by Raymond Hettinger.) * Many floating-point features were added. The *note float(): 187. function will now turn the string ‘nan’ into an IEEE 754 Not A Number value, and ‘+inf’ and ‘-inf’ into positive or negative infinity. This works on any platform with IEEE 754 semantics. (Contributed by Christian Heimes; bpo-1635(6).) Other functions in the *note math: b1. module, ‘isinf()’ and ‘isnan()’, return true if their floating-point argument is infinite or Not A Number. (bpo-1640(7)) Conversion functions were added to convert floating-point numbers into hexadecimal strings (bpo-3008(8)). These functions convert floats to and from a string representation without introducing rounding errors from the conversion between decimal and binary. Floats have a *note hex(): c66. method that returns a string representation, and the ‘float.fromhex()’ method converts a string back into a number: >>> a = 3.75 >>> a.hex() '0x1.e000000000000p+1' >>> float.fromhex('0x1.e000000000000p+1') 3.75 >>> b=1./3 >>> b.hex() '0x1.5555555555555p-2' * A numerical nicety: when creating a complex number from two floats on systems that support signed zeros (-0 and +0), the *note complex(): 189. constructor will now preserve the sign of the zero. (Fixed by Mark T. Dickinson; bpo-1507(9).) * Classes that inherit a *note __hash__(): 340. method from a parent class can set ‘__hash__ = None’ to indicate that the class isn’t hashable. This will make ‘hash(obj)’ raise a *note TypeError: 192. and the class will not be indicated as implementing the ‘Hashable’ ABC. You should do this when you’ve defined a ‘__cmp__()’ or *note __eq__(): 33f. method that compares objects by their value rather than by identity. All objects have a default hash method that uses ‘id(obj)’ as the hash value. There’s no tidy way to remove the *note __hash__(): 340. method inherited from a parent class, so assigning ‘None’ was implemented as an override. At the C level, extensions can set ‘tp_hash’ to *note PyObject_HashNotImplemented(): d31. (Fixed by Nick Coghlan and Amaury Forgeot d’Arc; bpo-2235(10).) * The *note GeneratorExit: d32. exception now subclasses *note BaseException: 1a8. instead of *note Exception: 1a9. This means that an exception handler that does ‘except Exception:’ will not inadvertently catch *note GeneratorExit: d32. (Contributed by Chad Austin; bpo-1537(11).) * Generator objects now have a ‘gi_code’ attribute that refers to the original code object backing the generator. (Contributed by Collin Winter; bpo-1473257(12).) * The *note compile(): 1b4. built-in function now accepts keyword arguments as well as positional parameters. (Contributed by Thomas Wouters; bpo-1444529(13).) * The *note complex(): 189. constructor now accepts strings containing parenthesized complex numbers, meaning that ‘complex(repr(cplx))’ will now round-trip values. For example, ‘complex('(3+4j)')’ now returns the value (3+4j). (bpo-1491866(14)) * The string ‘translate()’ method now accepts ‘None’ as the translation table parameter, which is treated as the identity transformation. This makes it easier to carry out operations that only delete characters. (Contributed by Bengt Richter and implemented by Raymond Hettinger; bpo-1193128(15).) * The built-in *note dir(): d33. function now checks for a *note __dir__(): 31b. method on the objects it receives. This method must return a list of strings containing the names of valid attributes for the object, and lets the object control the value that *note dir(): d33. produces. Objects that have *note __getattr__(): 31a. or *note __getattribute__(): 449. methods can use this to advertise pseudo-attributes they will honor. (bpo-1591665(16)) * Instance method objects have new attributes for the object and function comprising the method; the new synonym for ‘im_self’ is ‘__self__’, and ‘im_func’ is also available as ‘__func__’. The old names are still supported in Python 2.6, but are gone in 3.0. * An obscure change: when you use the *note locals(): 455. function inside a *note class: c6a. statement, the resulting dictionary no longer returns free variables. (Free variables, in this case, are variables referenced in the ‘class’ statement that aren’t attributes of the class.) * Menu: * Optimizations: Optimizations<9>. * Interpreter Changes: Interpreter Changes<2>. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1739468 (2) https://bugs.python.org/issue2196 (3) https://bugs.python.org/issue1686487 (4) https://bugs.python.org/issue3473 (5) https://bugs.python.org/issue2719 (6) https://bugs.python.org/issue1635 (7) https://bugs.python.org/issue1640 (8) https://bugs.python.org/issue3008 (9) https://bugs.python.org/issue1507 (10) https://bugs.python.org/issue2235 (11) https://bugs.python.org/issue1537 (12) https://bugs.python.org/issue1473257 (13) https://bugs.python.org/issue1444529 (14) https://bugs.python.org/issue1491866 (15) https://bugs.python.org/issue1193128 (16) https://bugs.python.org/issue1591665  File: python.info, Node: Optimizations<9>, Next: Interpreter Changes<2>, Up: Other Language Changes<10> 1.11.17.1 Optimizations ....................... * The *note warnings: 126. module has been rewritten in C. This makes it possible to invoke warnings from the parser, and may also make the interpreter’s startup faster. (Contributed by Neal Norwitz and Brett Cannon; bpo-1631171(1).) * Type objects now have a cache of methods that can reduce the work required to find the correct method implementation for a particular class; once cached, the interpreter doesn’t need to traverse base classes to figure out the right method to call. The cache is cleared if a base class or the class itself is modified, so the cache should remain correct even in the face of Python’s dynamic nature. (Original optimization implemented by Armin Rigo, updated for Python 2.6 by Kevin Jacobs; bpo-1700288(2).) By default, this change is only applied to types that are included with the Python core. Extension modules may not necessarily be compatible with this cache, so they must explicitly add ‘Py_TPFLAGS_HAVE_VERSION_TAG’ to the module’s ‘tp_flags’ field to enable the method cache. (To be compatible with the method cache, the extension module’s code must not directly access and modify the ‘tp_dict’ member of any of the types it implements. Most modules don’t do this, but it’s impossible for the Python interpreter to determine that. See bpo-1878(3) for some discussion.) * Function calls that use keyword arguments are significantly faster by doing a quick pointer comparison, usually saving the time of a full string comparison. (Contributed by Raymond Hettinger, after an initial implementation by Antoine Pitrou; bpo-1819(4).) * All of the functions in the *note struct: f8. module have been rewritten in C, thanks to work at the Need For Speed sprint. (Contributed by Raymond Hettinger.) * Some of the standard built-in types now set a bit in their type objects. This speeds up checking whether an object is a subclass of one of these types. (Contributed by Neal Norwitz.) * Unicode strings now use faster code for detecting whitespace and line breaks; this speeds up the ‘split()’ method by about 25% and ‘splitlines()’ by 35%. (Contributed by Antoine Pitrou.) Memory usage is reduced by using pymalloc for the Unicode string’s data. * The ‘with’ statement now stores the *note __exit__(): c96. method on the stack, producing a small speedup. (Implemented by Jeffrey Yasskin.) * To reduce memory usage, the garbage collector will now clear internal free lists when garbage-collecting the highest generation of objects. This may return memory to the operating system sooner. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1631171 (2) https://bugs.python.org/issue1700288 (3) https://bugs.python.org/issue1878 (4) https://bugs.python.org/issue1819  File: python.info, Node: Interpreter Changes<2>, Prev: Optimizations<9>, Up: Other Language Changes<10> 1.11.17.2 Interpreter Changes ............................. Two command-line options have been reserved for use by other Python implementations. The *note -J: d37. switch has been reserved for use by Jython for Jython-specific options, such as switches that are passed to the underlying JVM. *note -X: 155. has been reserved for options specific to a particular implementation of Python such as CPython, Jython, or IronPython. If either option is used with Python 2.6, the interpreter will report that the option isn’t currently used. Python can now be prevented from writing ‘.pyc’ or ‘.pyo’ files by supplying the *note -B: d38. switch to the Python interpreter, or by setting the *note PYTHONDONTWRITEBYTECODE: d39. environment variable before running the interpreter. This setting is available to Python programs as the ‘sys.dont_write_bytecode’ variable, and Python code can change the value to modify the interpreter’s behaviour. (Contributed by Neal Norwitz and Georg Brandl.) The encoding used for standard input, output, and standard error can be specified by setting the *note PYTHONIOENCODING: 92f. environment variable before running the interpreter. The value should be a string in the form ‘’ or ‘:’. The `encoding' part specifies the encoding’s name, e.g. ‘utf-8’ or ‘latin-1’; the optional `errorhandler' part specifies what to do with characters that can’t be handled by the encoding, and should be one of “error”, “ignore”, or “replace”. (Contributed by Martin von Löwis.)  File: python.info, Node: New and Improved Modules<2>, Next: Deprecations and Removals, Prev: Other Language Changes<10>, Up: What’s New in Python 2 6 1.11.18 New and Improved Modules -------------------------------- As in every release, Python’s standard library received a number of enhancements and bug fixes. Here’s a partial list of the most notable changes, sorted alphabetically by module name. Consult the ‘Misc/NEWS’ file in the source tree for a more complete list of changes, or look through the Subversion logs for all the details. * The *note asyncore: b. and *note asynchat: 9. modules are being actively maintained again, and a number of patches and bugfixes were applied. (Maintained by Josiah Carlson; see bpo-1736190(1) for one patch.) * The ‘bsddb’ module also has a new maintainer, Jesús Cea Avión, and the package is now available as a standalone package. The web page for the package is www.jcea.es/programacion/pybsddb.htm(2). The plan is to remove the package from the standard library in Python 3.0, because its pace of releases is much more frequent than Python’s. The ‘bsddb.dbshelve’ module now uses the highest pickling protocol available, instead of restricting itself to protocol 1. (Contributed by W. Barnes.) * The *note cgi: 16. module will now read variables from the query string of an HTTP POST request. This makes it possible to use form actions with URLs that include query strings such as “/cgi-bin/add.py?category=1”. (Contributed by Alexandre Fiori and Nubis; bpo-1817(3).) The ‘parse_qs()’ and ‘parse_qsl()’ functions have been relocated from the *note cgi: 16. module to the ‘urlparse’ module. The versions still available in the *note cgi: 16. module will trigger *note PendingDeprecationWarning: 279. messages in 2.6 (bpo-600362(4)). * The *note cmath: 19. module underwent extensive revision, contributed by Mark Dickinson and Christian Heimes. Five new functions were added: * ‘polar()’ converts a complex number to polar form, returning the modulus and argument of the complex number. * ‘rect()’ does the opposite, turning a modulus, argument pair back into the corresponding complex number. * ‘phase()’ returns the argument (also called the angle) of a complex number. * ‘isnan()’ returns True if either the real or imaginary part of its argument is a NaN. * ‘isinf()’ returns True if either the real or imaginary part of its argument is infinite. The revisions also improved the numerical soundness of the *note cmath: 19. module. For all functions, the real and imaginary parts of the results are accurate to within a few units of least precision (ulps) whenever possible. See bpo-1381(5) for the details. The branch cuts for ‘asinh()’, ‘atanh()’: and ‘atan()’ have also been corrected. The tests for the module have been greatly expanded; nearly 2000 new test cases exercise the algebraic functions. On IEEE 754 platforms, the *note cmath: 19. module now handles IEEE 754 special values and floating-point exceptions in a manner consistent with Annex ‘G’ of the C99 standard. * A new data type in the *note collections: 1e. module: ‘namedtuple(typename, fieldnames)’ is a factory function that creates subclasses of the standard tuple whose fields are accessible by name as well as index. For example: >>> var_type = collections.namedtuple('variable', ... 'id name type size') >>> # Names are separated by spaces or commas. >>> # 'id, name, type, size' would also work. >>> var_type._fields ('id', 'name', 'type', 'size') >>> var = var_type(1, 'frequency', 'int', 4) >>> print var[0], var.id # Equivalent 1 1 >>> print var[2], var.type # Equivalent int int >>> var._asdict() {'size': 4, 'type': 'int', 'id': 1, 'name': 'frequency'} >>> v2 = var._replace(name='amplitude') >>> v2 variable(id=1, name='amplitude', type='int', size=4) Several places in the standard library that returned tuples have been modified to return ‘namedtuple’ instances. For example, the ‘Decimal.as_tuple()’ method now returns a named tuple with ‘sign’, ‘digits’, and ‘exponent’ fields. (Contributed by Raymond Hettinger.) * Another change to the *note collections: 1e. module is that the ‘deque’ type now supports an optional `maxlen' parameter; if supplied, the deque’s size will be restricted to no more than `maxlen' items. Adding more items to a full deque causes old items to be discarded. >>> from collections import deque >>> dq=deque(maxlen=3) >>> dq deque([], maxlen=3) >>> dq.append(1); dq.append(2); dq.append(3) >>> dq deque([1, 2, 3], maxlen=3) >>> dq.append(4) >>> dq deque([2, 3, 4], maxlen=3) (Contributed by Raymond Hettinger.) * The ‘Cookie’ module’s ‘Morsel’ objects now support an ‘httponly’ attribute. In some browsers. cookies with this attribute set cannot be accessed or manipulated by JavaScript code. (Contributed by Arvin Schnell; bpo-1638033(6).) * A new window method in the *note curses: 2c. module, ‘chgat()’, changes the display attributes for a certain number of characters on a single line. (Contributed by Fabian Kreutz.) # Boldface text starting at y=0,x=21 # and affecting the rest of the line. stdscr.chgat(0, 21, curses.A_BOLD) The ‘Textbox’ class in the *note curses.textpad: 2f. module now supports editing in insert mode as well as overwrite mode. Insert mode is enabled by supplying a true value for the `insert_mode' parameter when creating the ‘Textbox’ instance. * The *note datetime: 31. module’s ‘strftime()’ methods now support a ‘%f’ format code that expands to the number of microseconds in the object, zero-padded on the left to six places. (Contributed by Skip Montanaro; bpo-1158(7).) * The *note decimal: 36. module was updated to version 1.66 of the General Decimal Specification(8). New features include some methods for some basic mathematical functions such as ‘exp()’ and ‘log10()’: >>> Decimal(1).exp() Decimal("2.718281828459045235360287471") >>> Decimal("2.7182818").ln() Decimal("0.9999999895305022877376682436") >>> Decimal(1000).log10() Decimal("3") The ‘as_tuple()’ method of ‘Decimal’ objects now returns a named tuple with ‘sign’, ‘digits’, and ‘exponent’ fields. (Implemented by Facundo Batista and Mark Dickinson. Named tuple support added by Raymond Hettinger.) * The *note difflib: 37. module’s ‘SequenceMatcher’ class now returns named tuples representing matches, with ‘a’, ‘b’, and ‘size’ attributes. (Contributed by Raymond Hettinger.) * An optional ‘timeout’ parameter, specifying a timeout measured in seconds, was added to the *note ftplib.FTP: 2f0. class constructor as well as the ‘connect()’ method. (Added by Facundo Batista.) Also, the ‘FTP’ class’s ‘storbinary()’ and ‘storlines()’ now take an optional `callback' parameter that will be called with each block of data after the data has been sent. (Contributed by Phil Schwartz; bpo-1221598(9).) * The ‘reduce()’ built-in function is also available in the *note functools: 85. module. In Python 3.0, the builtin has been dropped and ‘reduce()’ is only available from *note functools: 85.; currently there are no plans to drop the builtin in the 2.x series. (Patched by Christian Heimes; bpo-1739906(10).) * When possible, the *note getpass: 88. module will now use ‘/dev/tty’ to print a prompt message and read the password, falling back to standard error and standard input. If the password may be echoed to the terminal, a warning is printed before the prompt is displayed. (Contributed by Gregory P. Smith.) * The *note glob.glob(): 5c6. function can now return Unicode filenames if a Unicode path was used and Unicode filenames are matched within the directory. (bpo-1001604(11)) * A new function in the *note heapq: 8e. module, ‘merge(iter1, iter2, ...)’, takes any number of iterables returning data in sorted order, and returns a new generator that returns the contents of all the iterators, also in sorted order. For example: >>> list(heapq.merge([1, 3, 5, 9], [2, 8, 16])) [1, 2, 3, 5, 8, 9, 16] Another new function, ‘heappushpop(heap, item)’, pushes `item' onto `heap', then pops off and returns the smallest item. This is more efficient than making a call to ‘heappush()’ and then ‘heappop()’. *note heapq: 8e. is now implemented to only use less-than comparison, instead of the less-than-or-equal comparison it previously used. This makes *note heapq: 8e.’s usage of a type match the *note list.sort(): 445. method. (Contributed by Raymond Hettinger.) * An optional ‘timeout’ parameter, specifying a timeout measured in seconds, was added to the ‘httplib.HTTPConnection’ and ‘HTTPSConnection’ class constructors. (Added by Facundo Batista.) * Most of the *note inspect: a0. module’s functions, such as ‘getmoduleinfo()’ and ‘getargs()’, now return named tuples. In addition to behaving like tuples, the elements of the return value can also be accessed as attributes. (Contributed by Raymond Hettinger.) Some new functions in the module include ‘isgenerator()’, ‘isgeneratorfunction()’, and ‘isabstract()’. * The *note itertools: a3. module gained several new functions. ‘izip_longest(iter1, iter2, ...[, fillvalue])’ makes tuples from each of the elements; if some of the iterables are shorter than others, the missing values are set to `fillvalue'. For example: >>> tuple(itertools.izip_longest([1,2,3], [1,2,3,4,5])) ((1, 1), (2, 2), (3, 3), (None, 4), (None, 5)) ‘product(iter1, iter2, ..., [repeat=N])’ returns the Cartesian product of the supplied iterables, a set of tuples containing every possible combination of the elements returned from each iterable. >>> list(itertools.product([1,2,3], [4,5,6])) [(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)] The optional `repeat' keyword argument is used for taking the product of an iterable or a set of iterables with themselves, repeated `N' times. With a single iterable argument, `N'-tuples are returned: >>> list(itertools.product([1,2], repeat=3)) [(1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2), (2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)] With two iterables, `2N'-tuples are returned. >>> list(itertools.product([1,2], [3,4], repeat=2)) [(1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4), (1, 4, 1, 3), (1, 4, 1, 4), (1, 4, 2, 3), (1, 4, 2, 4), (2, 3, 1, 3), (2, 3, 1, 4), (2, 3, 2, 3), (2, 3, 2, 4), (2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4)] ‘combinations(iterable, r)’ returns sub-sequences of length `r' from the elements of `iterable'. >>> list(itertools.combinations('123', 2)) [('1', '2'), ('1', '3'), ('2', '3')] >>> list(itertools.combinations('123', 3)) [('1', '2', '3')] >>> list(itertools.combinations('1234', 3)) [('1', '2', '3'), ('1', '2', '4'), ('1', '3', '4'), ('2', '3', '4')] ‘permutations(iter[, r])’ returns all the permutations of length `r' of the iterable’s elements. If `r' is not specified, it will default to the number of elements produced by the iterable. >>> list(itertools.permutations([1,2,3,4], 2)) [(1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), (4, 1), (4, 2), (4, 3)] ‘itertools.chain(*iterables)’ is an existing function in *note itertools: a3. that gained a new constructor in Python 2.6. ‘itertools.chain.from_iterable(iterable)’ takes a single iterable that should return other iterables. ‘chain()’ will then return all the elements of the first iterable, then all the elements of the second, and so on. >>> list(itertools.chain.from_iterable([[1,2,3], [4,5,6]])) [1, 2, 3, 4, 5, 6] (All contributed by Raymond Hettinger.) * The *note logging: aa. module’s ‘FileHandler’ class and its subclasses ‘WatchedFileHandler’, ‘RotatingFileHandler’, and ‘TimedRotatingFileHandler’ now have an optional `delay' parameter to their constructors. If `delay' is true, opening of the log file is deferred until the first ‘emit()’ call is made. (Contributed by Vinay Sajip.) ‘TimedRotatingFileHandler’ also has a `utc' constructor parameter. If the argument is true, UTC time will be used in determining when midnight occurs and in generating filenames; otherwise local time will be used. * Several new functions were added to the *note math: b1. module: * *note isinf(): d3b. and *note isnan(): d3c. determine whether a given float is a (positive or negative) infinity or a NaN (Not a Number), respectively. * *note copysign(): d3d. copies the sign bit of an IEEE 754 number, returning the absolute value of `x' combined with the sign bit of `y'. For example, ‘math.copysign(1, -0.0)’ returns -1.0. (Contributed by Christian Heimes.) * *note factorial(): 1ea. computes the factorial of a number. (Contributed by Raymond Hettinger; bpo-2138(12).) * *note fsum(): d3e. adds up the stream of numbers from an iterable, and is careful to avoid loss of precision through using partial sums. (Contributed by Jean Brouwers, Raymond Hettinger, and Mark Dickinson; bpo-2819(13).) * *note acosh(): d3f, *note asinh(): d40. and *note atanh(): d41. compute the inverse hyperbolic functions. * *note log1p(): d42. returns the natural logarithm of `1+x' (base `e'). * ‘trunc()’ rounds a number toward zero, returning the closest ‘Integral’ that’s between the function’s argument and zero. Added as part of the backport of *note PEP 3141’s type hierarchy for numbers: c57. * The *note math: b1. module has been improved to give more consistent behaviour across platforms, especially with respect to handling of floating-point exceptions and IEEE 754 special values. Whenever possible, the module follows the recommendations of the C99 standard about 754’s special values. For example, ‘sqrt(-1.)’ should now give a *note ValueError: 1fb. across almost all platforms, while ‘sqrt(float('NaN'))’ should return a NaN on all IEEE 754 platforms. Where Annex ‘F’ of the C99 standard recommends signaling ‘divide-by-zero’ or ‘invalid’, Python will raise *note ValueError: 1fb. Where Annex ‘F’ of the C99 standard recommends signaling ‘overflow’, Python will raise *note OverflowError: 960. (See bpo-711019(14) and bpo-1640(15).) (Contributed by Christian Heimes and Mark Dickinson.) * *note mmap: 1ec. objects now have a ‘rfind()’ method that searches for a substring beginning at the end of the string and searching backwards. The ‘find()’ method also gained an `end' parameter giving an index at which to stop searching. (Contributed by John Lenton.) * The *note operator: c2. module gained a ‘methodcaller()’ function that takes a name and an optional set of arguments, returning a callable that will call the named function on any arguments passed to it. For example: >>> # Equivalent to lambda s: s.replace('old', 'new') >>> replacer = operator.methodcaller('replace', 'old', 'new') >>> replacer('old wine in old bottles') 'new wine in new bottles' (Contributed by Georg Brandl, after a suggestion by Gregory Petrosyan.) The ‘attrgetter()’ function now accepts dotted names and performs the corresponding attribute lookups: >>> inst_name = operator.attrgetter( ... '__class__.__name__') >>> inst_name('') 'str' >>> inst_name(help) '_Helper' (Contributed by Georg Brandl, after a suggestion by Barry Warsaw.) * The *note os: c4. module now wraps several new system calls. ‘fchmod(fd, mode)’ and ‘fchown(fd, uid, gid)’ change the mode and ownership of an opened file, and ‘lchmod(path, mode)’ changes the mode of a symlink. (Contributed by Georg Brandl and Christian Heimes.) ‘chflags()’ and ‘lchflags()’ are wrappers for the corresponding system calls (where they’re available), changing the flags set on a file. Constants for the flag values are defined in the *note stat: f4. module; some possible values include ‘UF_IMMUTABLE’ to signal the file may not be changed and ‘UF_APPEND’ to indicate that data can only be appended to the file. (Contributed by M. Levinson.) ‘os.closerange(low, high)’ efficiently closes all file descriptors from `low' to `high', ignoring any errors and not including `high' itself. This function is now used by the *note subprocess: f9. module to make starting processes faster. (Contributed by Georg Brandl; bpo-1663329(16).) * The ‘os.environ’ object’s ‘clear()’ method will now unset the environment variables using *note os.unsetenv(): d43. in addition to clearing the object’s keys. (Contributed by Martin Horcicka; bpo-1181(17).) * The *note os.walk(): 654. function now has a ‘followlinks’ parameter. If set to True, it will follow symlinks pointing to directories and visit the directory’s contents. For backward compatibility, the parameter’s default value is false. Note that the function can fall into an infinite recursion if there’s a symlink that points to a parent directory. (bpo-1273829(18)) * In the *note os.path: c5. module, the ‘splitext()’ function has been changed to not split on leading period characters. This produces better results when operating on Unix’s dot-files. For example, ‘os.path.splitext('.ipython')’ now returns ‘('.ipython', '')’ instead of ‘('', '.ipython')’. (bpo-1115886(19)) A new function, ‘os.path.relpath(path, start='.')’, returns a relative path from the ‘start’ path, if it’s supplied, or from the current working directory to the destination ‘path’. (Contributed by Richard Barran; bpo-1339796(20).) On Windows, *note os.path.expandvars(): d44. will now expand environment variables given in the form “%var%”, and “~user” will be expanded into the user’s home directory path. (Contributed by Josiah Carlson; bpo-957650(21).) * The Python debugger provided by the *note pdb: c9. module gained a new command: “run” restarts the Python program being debugged and can optionally take new command-line arguments for the program. (Contributed by Rocky Bernstein; bpo-1393667(22).) * The *note pdb.post_mortem(): d45. function, used to begin debugging a traceback, will now use the traceback returned by *note sys.exc_info(): c5f. if no traceback is supplied. (Contributed by Facundo Batista; bpo-1106316(23).) * The *note pickletools: cb. module now has an ‘optimize()’ function that takes a string containing a pickle and removes some unused opcodes, returning a shorter pickle that contains the same data structure. (Contributed by Raymond Hettinger.) * A ‘get_data()’ function was added to the *note pkgutil: cd. module that returns the contents of resource files included with an installed Python package. For example: >>> import pkgutil >>> print pkgutil.get_data('test', 'exception_hierarchy.txt') BaseException +-- SystemExit +-- KeyboardInterrupt +-- GeneratorExit +-- Exception +-- StopIteration +-- StandardError ... (Contributed by Paul Moore; bpo-2439(24).) * The ‘pyexpat’ module’s ‘Parser’ objects now allow setting their ‘buffer_size’ attribute to change the size of the buffer used to hold character data. (Contributed by Achim Gaedke; bpo-1137(25).) * The ‘Queue’ module now provides queue variants that retrieve entries in different orders. The ‘PriorityQueue’ class stores queued items in a heap and retrieves them in priority order, and ‘LifoQueue’ retrieves the most recently added entries first, meaning that it behaves like a stack. (Contributed by Raymond Hettinger.) * The *note random: dc. module’s ‘Random’ objects can now be pickled on a 32-bit system and unpickled on a 64-bit system, and vice versa. Unfortunately, this change also means that Python 2.6’s ‘Random’ objects can’t be unpickled correctly on earlier versions of Python. (Contributed by Shawn Ligocki; bpo-1727780(26).) The new ‘triangular(low, high, mode)’ function returns random numbers following a triangular distribution. The returned values are between `low' and `high', not including `high' itself, and with `mode' as the most frequently occurring value in the distribution. (Contributed by Wladmir van der Laan and Raymond Hettinger; bpo-1681432(27).) * Long regular expression searches carried out by the *note re: dd. module will check for signals being delivered, so time-consuming searches can now be interrupted. (Contributed by Josh Hoyt and Ralf Schmitt; bpo-846388(28).) The regular expression module is implemented by compiling bytecodes for a tiny regex-specific virtual machine. Untrusted code could create malicious strings of bytecode directly and cause crashes, so Python 2.6 includes a verifier for the regex bytecode. (Contributed by Guido van Rossum from work for Google App Engine; bpo-3487(29).) * The *note rlcompleter: e1. module’s ‘Completer.complete()’ method will now ignore exceptions triggered while evaluating a name. (Fixed by Lorenz Quack; bpo-2250(30).) * The *note sched: e3. module’s ‘scheduler’ instances now have a read-only *note queue: da. attribute that returns the contents of the scheduler’s queue, represented as a list of named tuples with the fields ‘(time, priority, action, argument)’. (Contributed by Raymond Hettinger; bpo-1861(31).) * The *note select: e5. module now has wrapper functions for the Linux ‘epoll()’ and BSD ‘kqueue()’ system calls. ‘modify()’ method was added to the existing ‘poll’ objects; ‘pollobj.modify(fd, eventmask)’ takes a file descriptor or file object and an event mask, modifying the recorded event mask for that file. (Contributed by Christian Heimes; bpo-1657(32).) * The *note shutil.copytree(): 21a. function now has an optional `ignore' argument that takes a callable object. This callable will receive each directory path and a list of the directory’s contents, and returns a list of names that will be ignored, not copied. The *note shutil: e9. module also provides an ‘ignore_patterns()’ function for use with this new parameter. ‘ignore_patterns()’ takes an arbitrary number of glob-style patterns and returns a callable that will ignore any files and directories that match any of these patterns. The following example copies a directory tree, but skips both ‘.svn’ directories and Emacs backup files, which have names ending with ‘~’: shutil.copytree('Doc/library', '/tmp/library', ignore=shutil.ignore_patterns('*~', '.svn')) (Contributed by Tarek Ziadé; bpo-2663(33).) * Integrating signal handling with GUI handling event loops like those used by Tkinter or GTk+ has long been a problem; most software ends up polling, waking up every fraction of a second to check if any GUI events have occurred. The *note signal: ea. module can now make this more efficient. Calling ‘signal.set_wakeup_fd(fd)’ sets a file descriptor to be used; when a signal is received, a byte is written to that file descriptor. There’s also a C-level function, *note PySignal_SetWakeupFd(): d46, for setting the descriptor. Event loops will use this by opening a pipe to create two descriptors, one for reading and one for writing. The writable descriptor will be passed to ‘set_wakeup_fd()’, and the readable descriptor will be added to the list of descriptors monitored by the event loop via ‘select()’ or ‘poll()’. On receiving a signal, a byte will be written and the main event loop will be woken up, avoiding the need to poll. (Contributed by Adam Olsen; bpo-1583(34).) The ‘siginterrupt()’ function is now available from Python code, and allows changing whether signals can interrupt system calls or not. (Contributed by Ralf Schmitt.) The ‘setitimer()’ and ‘getitimer()’ functions have also been added (where they’re available). ‘setitimer()’ allows setting interval timers that will cause a signal to be delivered to the process after a specified time, measured in wall-clock time, consumed process time, or combined process+system time. (Contributed by Guilherme Polo; bpo-2240(35).) * The *note smtplib: ed. module now supports SMTP over SSL thanks to the addition of the ‘SMTP_SSL’ class. This class supports an interface identical to the existing ‘SMTP’ class. (Contributed by Monty Taylor.) Both class constructors also have an optional ‘timeout’ parameter that specifies a timeout for the initial connection attempt, measured in seconds. (Contributed by Facundo Batista.) An implementation of the LMTP protocol ( RFC 2033(36)) was also added to the module. LMTP is used in place of SMTP when transferring e-mail between agents that don’t manage a mail queue. (LMTP implemented by Leif Hedstrom; bpo-957003(37).) ‘SMTP.starttls()’ now complies with RFC 3207(38) and forgets any knowledge obtained from the server not obtained from the TLS negotiation itself. (Patch contributed by Bill Fenner; bpo-829951(39).) * The *note socket: ef. module now supports TIPC (‘http://tipc.sourceforge.net/’), a high-performance non-IP-based protocol designed for use in clustered environments. TIPC addresses are 4- or 5-tuples. (Contributed by Alberto Bertogli; bpo-1646(40).) A new function, ‘create_connection()’, takes an address and connects to it using an optional timeout value, returning the connected socket object. This function also looks up the address’s type and connects to it using IPv4 or IPv6 as appropriate. Changing your code to use ‘create_connection()’ instead of ‘socket(socket.AF_INET, ...)’ may be all that’s required to make your code work with IPv6. * The base classes in the ‘SocketServer’ module now support calling a ‘handle_timeout()’ method after a span of inactivity specified by the server’s ‘timeout’ attribute. (Contributed by Michael Pomraning.) The ‘serve_forever()’ method now takes an optional poll interval measured in seconds, controlling how often the server will check for a shutdown request. (Contributed by Pedro Werneck and Jeffrey Yasskin; bpo-742598(41), bpo-1193577(42).) * The *note sqlite3: f2. module, maintained by Gerhard Häring, has been updated from version 2.3.2 in Python 2.5 to version 2.4.1. * The *note struct: f8. module now supports the C99 ‘_Bool’ type, using the format character ‘'?'’. (Contributed by David Remahl.) * The ‘Popen’ objects provided by the *note subprocess: f9. module now have ‘terminate()’, ‘kill()’, and ‘send_signal()’ methods. On Windows, ‘send_signal()’ only supports the ‘SIGTERM’ signal, and all these methods are aliases for the Win32 API function ‘TerminateProcess()’. (Contributed by Christian Heimes.) * A new variable in the *note sys: fd. module, ‘float_info’, is an object containing information derived from the ‘float.h’ file about the platform’s floating-point support. Attributes of this object include ‘mant_dig’ (number of digits in the mantissa), ‘epsilon’ (smallest difference between 1.0 and the next largest value representable), and several others. (Contributed by Christian Heimes; bpo-1534(43).) Another new variable, ‘dont_write_bytecode’, controls whether Python writes any ‘.pyc’ or ‘.pyo’ files on importing a module. If this variable is true, the compiled files are not written. The variable is initially set on start-up by supplying the *note -B: d38. switch to the Python interpreter, or by setting the *note PYTHONDONTWRITEBYTECODE: d39. environment variable before running the interpreter. Python code can subsequently change the value of this variable to control whether bytecode files are written or not. (Contributed by Neal Norwitz and Georg Brandl.) Information about the command-line arguments supplied to the Python interpreter is available by reading attributes of a named tuple available as ‘sys.flags’. For example, the ‘verbose’ attribute is true if Python was executed in verbose mode, ‘debug’ is true in debugging mode, etc. These attributes are all read-only. (Contributed by Christian Heimes.) A new function, ‘getsizeof()’, takes a Python object and returns the amount of memory used by the object, measured in bytes. Built-in objects return correct results; third-party extensions may not, but can define a ‘__sizeof__()’ method to return the object’s size. (Contributed by Robert Schuppenies; bpo-2898(44).) It’s now possible to determine the current profiler and tracer functions by calling *note sys.getprofile(): d47. and *note sys.gettrace(): d48. (Contributed by Georg Brandl; bpo-1648(45).) * The *note tarfile: 101. module now supports POSIX.1-2001 (pax) tarfiles in addition to the POSIX.1-1988 (ustar) and GNU tar formats that were already supported. The default format is GNU tar; specify the ‘format’ parameter to open a file using a different format: tar = tarfile.open("output.tar", "w", format=tarfile.PAX_FORMAT) The new ‘encoding’ and ‘errors’ parameters specify an encoding and an error handling scheme for character conversions. ‘'strict'’, ‘'ignore'’, and ‘'replace'’ are the three standard ways Python can handle errors,; ‘'utf-8'’ is a special value that replaces bad characters with their UTF-8 representation. (Character conversions occur because the PAX format supports Unicode filenames, defaulting to UTF-8 encoding.) The ‘TarFile.add()’ method now accepts an ‘exclude’ argument that’s a function that can be used to exclude certain filenames from an archive. The function must take a filename and return true if the file should be excluded or false if it should be archived. The function is applied to both the name initially passed to ‘add()’ and to the names of files in recursively-added directories. (All changes contributed by Lars Gustäbel). * An optional ‘timeout’ parameter was added to the *note telnetlib.Telnet: 597. class constructor, specifying a timeout measured in seconds. (Added by Facundo Batista.) * The *note tempfile.NamedTemporaryFile: d49. class usually deletes the temporary file it created when the file is closed. This behaviour can now be changed by passing ‘delete=False’ to the constructor. (Contributed by Damien Miller; bpo-1537850(46).) A new class, ‘SpooledTemporaryFile’, behaves like a temporary file but stores its data in memory until a maximum size is exceeded. On reaching that limit, the contents will be written to an on-disk temporary file. (Contributed by Dustin J. Mitchell.) The ‘NamedTemporaryFile’ and ‘SpooledTemporaryFile’ classes both work as context managers, so you can write ‘with tempfile.NamedTemporaryFile() as tmp: ...’. (Contributed by Alexander Belopolsky; bpo-2021(47).) * The ‘test.test_support’ module gained a number of context managers useful for writing tests. ‘EnvironmentVarGuard()’ is a context manager that temporarily changes environment variables and automatically restores them to their old values. Another context manager, ‘TransientResource’, can surround calls to resources that may or may not be available; it will catch and ignore a specified list of exceptions. For example, a network test may ignore certain failures when connecting to an external web site: with test_support.TransientResource(IOError, errno=errno.ETIMEDOUT): f = urllib.urlopen('https://sf.net') ... Finally, ‘check_warnings()’ resets the ‘warning’ module’s warning filters and returns an object that will record all warning messages triggered (bpo-3781(48)): with test_support.check_warnings() as wrec: warnings.simplefilter("always") # ... code that triggers a warning ... assert str(wrec.message) == "function is outdated" assert len(wrec.warnings) == 1, "Multiple warnings raised" (Contributed by Brett Cannon.) * The *note textwrap: 108. module can now preserve existing whitespace at the beginnings and ends of the newly-created lines by specifying ‘drop_whitespace=False’ as an argument: >>> S = """This sentence has a bunch of ... extra whitespace.""" >>> print textwrap.fill(S, width=15) This sentence has a bunch of extra whitespace. >>> print textwrap.fill(S, drop_whitespace=False, width=15) This sentence has a bunch of extra whitespace. >>> (Contributed by Dwayne Bailey; bpo-1581073(49).) * The *note threading: 109. module API is being changed to use properties such as ‘daemon’ instead of ‘setDaemon()’ and ‘isDaemon()’ methods, and some methods have been renamed to use underscores instead of camel-case; for example, the ‘activeCount()’ method is renamed to ‘active_count()’. Both the 2.6 and 3.0 versions of the module support the same properties and renamed methods, but don’t remove the old methods. No date has been set for the deprecation of the old APIs in Python 3.x; the old APIs won’t be removed in any 2.x version. (Carried out by several people, most notably Benjamin Peterson.) The *note threading: 109. module’s ‘Thread’ objects gained an ‘ident’ property that returns the thread’s identifier, a nonzero integer. (Contributed by Gregory P. Smith; bpo-2871(50).) * The *note timeit: 10b. module now accepts callables as well as strings for the statement being timed and for the setup code. Two convenience functions were added for creating ‘Timer’ instances: ‘repeat(stmt, setup, time, repeat, number)’ and ‘timeit(stmt, setup, time, number)’ create an instance and call the corresponding method. (Contributed by Erik Demaine; bpo-1533909(51).) * The ‘Tkinter’ module now accepts lists and tuples for options, separating the elements by spaces before passing the resulting value to Tcl/Tk. (Contributed by Guilherme Polo; bpo-2906(52).) * The *note turtle: 116. module for turtle graphics was greatly enhanced by Gregor Lingl. New features in the module include: * Better animation of turtle movement and rotation. * Control over turtle movement using the new ‘delay()’, ‘tracer()’, and ‘speed()’ methods. * The ability to set new shapes for the turtle, and to define a new coordinate system. * Turtles now have an ‘undo()’ method that can roll back actions. * Simple support for reacting to input events such as mouse and keyboard activity, making it possible to write simple games. * A ‘turtle.cfg’ file can be used to customize the starting appearance of the turtle’s screen. * The module’s docstrings can be replaced by new docstrings that have been translated into another language. (bpo-1513695(53)) * An optional ‘timeout’ parameter was added to the ‘urllib.urlopen()’ function and the ‘urllib.ftpwrapper’ class constructor, as well as the ‘urllib2.urlopen()’ function. The parameter specifies a timeout measured in seconds. For example: >>> u = urllib2.urlopen("http://slow.example.com", timeout=3) Traceback (most recent call last): ... urllib2.URLError: >>> (Added by Facundo Batista.) * The Unicode database provided by the *note unicodedata: 11a. module has been updated to version 5.1.0. (Updated by Martin von Löwis; bpo-3811(54).) * The *note warnings: 126. module’s ‘formatwarning()’ and ‘showwarning()’ gained an optional `line' argument that can be used to supply the line of source code. (Added as part of bpo-1631171(55), which re-implemented part of the *note warnings: 126. module in C code.) A new function, ‘catch_warnings()’, is a context manager intended for testing purposes that lets you temporarily modify the warning filters and then restore their original values (bpo-3781(56)). * The XML-RPC ‘SimpleXMLRPCServer’ and ‘DocXMLRPCServer’ classes can now be prevented from immediately opening and binding to their socket by passing ‘False’ as the `bind_and_activate' constructor parameter. This can be used to modify the instance’s ‘allow_reuse_address’ attribute before calling the ‘server_bind()’ and ‘server_activate()’ methods to open the socket and begin listening for connections. (Contributed by Peter Parente; bpo-1599845(57).) ‘SimpleXMLRPCServer’ also has a ‘_send_traceback_header’ attribute; if true, the exception and formatted traceback are returned as HTTP headers “X-Exception” and “X-Traceback”. This feature is for debugging purposes only and should not be used on production servers because the tracebacks might reveal passwords or other sensitive information. (Contributed by Alan McIntyre as part of his project for Google’s Summer of Code 2007.) * The ‘xmlrpclib’ module no longer automatically converts *note datetime.date: 193. and *note datetime.time: 4f3. to the ‘xmlrpclib.DateTime’ type; the conversion semantics were not necessarily correct for all applications. Code using ‘xmlrpclib’ should convert ‘date’ and *note time: 4f3. instances. (bpo-1330538(58)) The code can also handle dates before 1900 (contributed by Ralf Schmitt; bpo-2014(59)) and 64-bit integers represented by using ‘’ in XML-RPC responses (contributed by Riku Lindblad; bpo-2985(60)). * The *note zipfile: 142. module’s ‘ZipFile’ class now has ‘extract()’ and ‘extractall()’ methods that will unpack a single file or all the files in the archive to the current directory, or to a specified directory: z = zipfile.ZipFile('python-251.zip') # Unpack a single file, writing it relative # to the /tmp directory. z.extract('Python/sysmodule.c', '/tmp') # Unpack all the files in the archive. z.extractall() (Contributed by Alan McIntyre; bpo-467924(61).) The *note open(): 4f0, ‘read()’ and ‘extract()’ methods can now take either a filename or a ‘ZipInfo’ object. This is useful when an archive accidentally contains a duplicated filename. (Contributed by Graham Horler; bpo-1775025(62).) Finally, *note zipfile: 142. now supports using Unicode filenames for archived files. (Contributed by Alexey Borzenkov; bpo-1734346(63).) * Menu: * The ast module:: * The future_builtins module:: * The json module; JavaScript Object Notation: The json module JavaScript Object Notation. * The plistlib module; A Property-List Parser: The plistlib module A Property-List Parser. * ctypes Enhancements:: * Improved SSL Support:: ---------- Footnotes ---------- (1) https://bugs.python.org/issue1736190 (2) https://www.jcea.es/programacion/pybsddb.htm (3) https://bugs.python.org/issue1817 (4) https://bugs.python.org/issue600362 (5) https://bugs.python.org/issue1381 (6) https://bugs.python.org/issue1638033 (7) https://bugs.python.org/issue1158 (8) http://speleotrove.com/decimal/decarith.html (9) https://bugs.python.org/issue1221598 (10) https://bugs.python.org/issue1739906 (11) https://bugs.python.org/issue1001604 (12) https://bugs.python.org/issue2138 (13) https://bugs.python.org/issue2819 (14) https://bugs.python.org/issue711019 (15) https://bugs.python.org/issue1640 (16) https://bugs.python.org/issue1663329 (17) https://bugs.python.org/issue1181 (18) https://bugs.python.org/issue1273829 (19) https://bugs.python.org/issue1115886 (20) https://bugs.python.org/issue1339796 (21) https://bugs.python.org/issue957650 (22) https://bugs.python.org/issue1393667 (23) https://bugs.python.org/issue1106316 (24) https://bugs.python.org/issue2439 (25) https://bugs.python.org/issue1137 (26) https://bugs.python.org/issue1727780 (27) https://bugs.python.org/issue1681432 (28) https://bugs.python.org/issue846388 (29) https://bugs.python.org/issue3487 (30) https://bugs.python.org/issue2250 (31) https://bugs.python.org/issue1861 (32) https://bugs.python.org/issue1657 (33) https://bugs.python.org/issue2663 (34) https://bugs.python.org/issue1583 (35) https://bugs.python.org/issue2240 (36) https://tools.ietf.org/html/rfc2033.html (37) https://bugs.python.org/issue957003 (38) https://tools.ietf.org/html/rfc3207.html (39) https://bugs.python.org/issue829951 (40) https://bugs.python.org/issue1646 (41) https://bugs.python.org/issue742598 (42) https://bugs.python.org/issue1193577 (43) https://bugs.python.org/issue1534 (44) https://bugs.python.org/issue2898 (45) https://bugs.python.org/issue1648 (46) https://bugs.python.org/issue1537850 (47) https://bugs.python.org/issue2021 (48) https://bugs.python.org/issue3781 (49) https://bugs.python.org/issue1581073 (50) https://bugs.python.org/issue2871 (51) https://bugs.python.org/issue1533909 (52) https://bugs.python.org/issue2906 (53) https://bugs.python.org/issue1513695 (54) https://bugs.python.org/issue3811 (55) https://bugs.python.org/issue1631171 (56) https://bugs.python.org/issue3781 (57) https://bugs.python.org/issue1599845 (58) https://bugs.python.org/issue1330538 (59) https://bugs.python.org/issue2014 (60) https://bugs.python.org/issue2985 (61) https://bugs.python.org/issue467924 (62) https://bugs.python.org/issue1775025 (63) https://bugs.python.org/issue1734346  File: python.info, Node: The ast module, Next: The future_builtins module, Up: New and Improved Modules<2> 1.11.18.1 The ‘ast’ module .......................... The *note ast: 8. module provides an Abstract Syntax Tree representation of Python code, and Armin Ronacher contributed a set of helper functions that perform a variety of common tasks. These will be useful for HTML templating packages, code analyzers, and similar tools that process Python code. The ‘parse()’ function takes an expression and returns an AST. The ‘dump()’ function outputs a representation of a tree, suitable for debugging: import ast t = ast.parse(""" d = {} for i in 'abcdefghijklm': d[i + i] = ord(i) - ord('a') + 1 print d """) print ast.dump(t) This outputs a deeply nested tree: Module(body=[ Assign(targets=[ Name(id='d', ctx=Store()) ], value=Dict(keys=[], values=[])) For(target=Name(id='i', ctx=Store()), iter=Str(s='abcdefghijklm'), body=[ Assign(targets=[ Subscript(value= Name(id='d', ctx=Load()), slice= Index(value= BinOp(left=Name(id='i', ctx=Load()), op=Add(), right=Name(id='i', ctx=Load()))), ctx=Store()) ], value= BinOp(left= BinOp(left= Call(func= Name(id='ord', ctx=Load()), args=[ Name(id='i', ctx=Load()) ], keywords=[], starargs=None, kwargs=None), op=Sub(), right=Call(func= Name(id='ord', ctx=Load()), args=[ Str(s='a') ], keywords=[], starargs=None, kwargs=None)), op=Add(), right=Num(n=1))) ], orelse=[]) Print(dest=None, values=[ Name(id='d', ctx=Load()) ], nl=True) ]) The ‘literal_eval()’ method takes a string or an AST representing a literal expression, parses and evaluates it, and returns the resulting value. A literal expression is a Python expression containing only strings, numbers, dictionaries, etc. but no statements or function calls. If you need to evaluate an expression but cannot accept the security risk of using an *note eval(): b90. call, ‘literal_eval()’ will handle it safely: >>> literal = '("a", "b", {2:4, 3:8, 1:2})' >>> print ast.literal_eval(literal) ('a', 'b', {1: 2, 2: 4, 3: 8}) >>> print ast.literal_eval('"a" + "b"') Traceback (most recent call last): ... ValueError: malformed string The module also includes ‘NodeVisitor’ and ‘NodeTransformer’ classes for traversing and modifying an AST, and functions for common transformations such as changing line numbers.  File: python.info, Node: The future_builtins module, Next: The json module JavaScript Object Notation, Prev: The ast module, Up: New and Improved Modules<2> 1.11.18.2 The ‘future_builtins’ module ...................................... Python 3.0 makes many changes to the repertoire of built-in functions, and most of the changes can’t be introduced in the Python 2.x series because they would break compatibility. The ‘future_builtins’ module provides versions of these built-in functions that can be imported when writing 3.0-compatible code. The functions in this module currently include: * ‘ascii(obj)’: equivalent to *note repr(): 7cc. In Python 3.0, *note repr(): 7cc. will return a Unicode string, while *note ascii(): d4c. will return a pure ASCII bytestring. * ‘filter(predicate, iterable)’, ‘map(func, iterable1, ...)’: the 3.0 versions return iterators, unlike the 2.x builtins which return lists. * ‘hex(value)’, ‘oct(value)’: instead of calling the ‘__hex__()’ or ‘__oct__()’ methods, these versions will call the *note __index__(): 18a. method and convert the result to hexadecimal or octal. *note oct(): c65. will use the new ‘0o’ notation for its result.  File: python.info, Node: The json module JavaScript Object Notation, Next: The plistlib module A Property-List Parser, Prev: The future_builtins module, Up: New and Improved Modules<2> 1.11.18.3 The ‘json’ module: JavaScript Object Notation ....................................................... The new *note json: a4. module supports the encoding and decoding of Python types in JSON (Javascript Object Notation). JSON is a lightweight interchange format often used in web applications. For more information about JSON, see ‘http://www.json.org’. *note json: a4. comes with support for decoding and encoding most built-in Python types. The following example encodes and decodes a dictionary: >>> import json >>> data = {"spam": "foo", "parrot": 42} >>> in_json = json.dumps(data) # Encode the data >>> in_json '{"parrot": 42, "spam": "foo"}' >>> json.loads(in_json) # Decode into a Python object {"spam": "foo", "parrot": 42} It’s also possible to write your own decoders and encoders to support more types. Pretty-printing of the JSON strings is also supported. *note json: a4. (originally called simplejson) was written by Bob Ippolito.  File: python.info, Node: The plistlib module A Property-List Parser, Next: ctypes Enhancements, Prev: The json module JavaScript Object Notation, Up: New and Improved Modules<2> 1.11.18.4 The ‘plistlib’ module: A Property-List Parser ....................................................... The ‘.plist’ format is commonly used on Mac OS X to store basic data types (numbers, strings, lists, and dictionaries) by serializing them into an XML-based format. It resembles the XML-RPC serialization of data types. Despite being primarily used on Mac OS X, the format has nothing Mac-specific about it and the Python implementation works on any platform that Python supports, so the *note plistlib: cf. module has been promoted to the standard library. Using the module is simple: import sys import plistlib import datetime # Create data structure data_struct = dict(lastAccessed=datetime.datetime.now(), version=1, categories=('Personal','Shared','Private')) # Create string containing XML. plist_str = plistlib.writePlistToString(data_struct) new_struct = plistlib.readPlistFromString(plist_str) print data_struct print new_struct # Write data structure to a file and read it back. plistlib.writePlist(data_struct, '/tmp/customizations.plist') new_struct = plistlib.readPlist('/tmp/customizations.plist') # read/writePlist accepts file-like objects as well as paths. plistlib.writePlist(data_struct, sys.stdout)  File: python.info, Node: ctypes Enhancements, Next: Improved SSL Support, Prev: The plistlib module A Property-List Parser, Up: New and Improved Modules<2> 1.11.18.5 ctypes Enhancements ............................. Thomas Heller continued to maintain and enhance the *note ctypes: 2b. module. *note ctypes: 2b. now supports a ‘c_bool’ datatype that represents the C99 ‘bool’ type. (Contributed by David Remahl; bpo-1649190(1).) The *note ctypes: 2b. string, buffer and array types have improved support for extended slicing syntax, where various combinations of ‘(start, stop, step)’ are supplied. (Implemented by Thomas Wouters.) All *note ctypes: 2b. data types now support ‘from_buffer()’ and ‘from_buffer_copy()’ methods that create a ctypes instance based on a provided buffer object. ‘from_buffer_copy()’ copies the contents of the object, while ‘from_buffer()’ will share the same memory area. A new calling convention tells *note ctypes: 2b. to clear the ‘errno’ or Win32 LastError variables at the outset of each wrapped call. (Implemented by Thomas Heller; bpo-1798(2).) You can now retrieve the Unix ‘errno’ variable after a function call. When creating a wrapped function, you can supply ‘use_errno=True’ as a keyword parameter to the ‘DLL()’ function and then call the module-level methods ‘set_errno()’ and ‘get_errno()’ to set and retrieve the error value. The Win32 LastError variable is similarly supported by the ‘DLL()’, ‘OleDLL()’, and ‘WinDLL()’ functions. You supply ‘use_last_error=True’ as a keyword parameter and then call the module-level methods ‘set_last_error()’ and ‘get_last_error()’. The ‘byref()’ function, used to retrieve a pointer to a ctypes instance, now has an optional `offset' parameter that is a byte count that will be added to the returned pointer. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1649190 (2) https://bugs.python.org/issue1798  File: python.info, Node: Improved SSL Support, Prev: ctypes Enhancements, Up: New and Improved Modules<2> 1.11.18.6 Improved SSL Support .............................. Bill Janssen made extensive improvements to Python 2.6’s support for the Secure Sockets Layer by adding a new module, *note ssl: f3, that’s built atop the OpenSSL(1) library. This new module provides more control over the protocol negotiated, the X.509 certificates used, and has better support for writing SSL servers (as opposed to clients) in Python. The existing SSL support in the *note socket: ef. module hasn’t been removed and continues to work, though it will be removed in Python 3.0. To use the new module, you must first create a TCP connection in the usual way and then pass it to the *note ssl.wrap_socket(): 46f. function. It’s possible to specify whether a certificate is required, and to obtain certificate info by calling the ‘getpeercert()’ method. See also ........ The documentation for the *note ssl: f3. module. ---------- Footnotes ---------- (1) https://www.openssl.org/  File: python.info, Node: Deprecations and Removals, Next: Build and C API Changes<9>, Prev: New and Improved Modules<2>, Up: What’s New in Python 2 6 1.11.19 Deprecations and Removals --------------------------------- * String exceptions have been removed. Attempting to use them raises a *note TypeError: 192. * Changes to the *note Exception: 1a9. interface as dictated by PEP 352(1) continue to be made. For 2.6, the ‘message’ attribute is being deprecated in favor of the ‘args’ attribute. * (3.0-warning mode) Python 3.0 will feature a reorganized standard library that will drop many outdated modules and rename others. Python 2.6 running in 3.0-warning mode will warn about these modules when they are imported. The list of deprecated modules is: ‘audiodev’, ‘bgenlocations’, ‘buildtools’, ‘bundlebuilder’, ‘Canvas’, ‘compiler’, ‘dircache’, ‘dl’, ‘fpformat’, ‘gensuitemodule’, ‘ihooks’, ‘imageop’, ‘imgfile’, ‘linuxaudiodev’, ‘mhlib’, ‘mimetools’, ‘multifile’, ‘new’, ‘pure’, ‘statvfs’, ‘sunaudiodev’, ‘test.testall’, and ‘toaiff’. * The ‘gopherlib’ module has been removed. * The ‘MimeWriter’ module and ‘mimify’ module have been deprecated; use the *note email: 69. package instead. * The ‘md5’ module has been deprecated; use the *note hashlib: 8d. module instead. * The ‘posixfile’ module has been deprecated; *note fcntl.lockf(): d52. provides better locking. * The ‘popen2’ module has been deprecated; use the *note subprocess: f9. module. * The ‘rgbimg’ module has been removed. * The ‘sets’ module has been deprecated; it’s better to use the built-in *note set: b6f. and *note frozenset: bee. types. * The ‘sha’ module has been deprecated; use the *note hashlib: 8d. module instead. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0352  File: python.info, Node: Build and C API Changes<9>, Next: Porting to Python 2 6, Prev: Deprecations and Removals, Up: What’s New in Python 2 6 1.11.20 Build and C API Changes ------------------------------- Changes to Python’s build process and to the C API include: * Python now must be compiled with C89 compilers (after 19 years!). This means that the Python source tree has dropped its own implementations of ‘memmove()’ and ‘strerror()’, which are in the C89 standard library. * Python 2.6 can be built with Microsoft Visual Studio 2008 (version 9.0), and this is the new default compiler. See the ‘PCbuild’ directory for the build files. (Implemented by Christian Heimes.) * On Mac OS X, Python 2.6 can be compiled as a 4-way universal build. The ‘configure’ script can take a ‘--with-universal-archs=[32-bit|64-bit|all]’ switch, controlling whether the binaries are built for 32-bit architectures (x86, PowerPC), 64-bit (x86-64 and PPC-64), or both. (Contributed by Ronald Oussoren.) * The BerkeleyDB module now has a C API object, available as ‘bsddb.db.api’. This object can be used by other C extensions that wish to use the ‘bsddb’ module for their own purposes. (Contributed by Duncan Grisby.) * The new buffer interface, previously described in *note the PEP 3118 section: d24, adds *note PyObject_GetBuffer(): d25. and *note PyBuffer_Release(): d54, as well as a few other functions. * Python’s use of the C stdio library is now thread-safe, or at least as thread-safe as the underlying library is. A long-standing potential bug occurred if one thread closed a file object while another thread was reading from or writing to the object. In 2.6 file objects have a reference count, manipulated by the ‘PyFile_IncUseCount()’ and ‘PyFile_DecUseCount()’ functions. File objects can’t be closed unless the reference count is zero. ‘PyFile_IncUseCount()’ should be called while the GIL is still held, before carrying out an I/O operation using the ‘FILE *’ pointer, and ‘PyFile_DecUseCount()’ should be called immediately after the GIL is re-acquired. (Contributed by Antoine Pitrou and Gregory P. Smith.) * Importing modules simultaneously in two different threads no longer deadlocks; it will now raise an *note ImportError: 334. A new API function, *note PyImport_ImportModuleNoBlock(): 9c1, will look for a module in ‘sys.modules’ first, then try to import it after acquiring an import lock. If the import lock is held by another thread, an *note ImportError: 334. is raised. (Contributed by Christian Heimes.) * Several functions return information about the platform’s floating-point support. *note PyFloat_GetMax(): d55. returns the maximum representable floating point value, and *note PyFloat_GetMin(): d56. returns the minimum positive value. *note PyFloat_GetInfo(): d57. returns an object containing more information from the ‘float.h’ file, such as ‘"mant_dig"’ (number of digits in the mantissa), ‘"epsilon"’ (smallest difference between 1.0 and the next largest value representable), and several others. (Contributed by Christian Heimes; bpo-1534(1).) * C functions and methods that use *note PyComplex_AsCComplex(): d58. will now accept arguments that have a *note __complex__(): 18d. method. In particular, the functions in the *note cmath: 19. module will now accept objects with this method. This is a backport of a Python 3.0 change. (Contributed by Mark Dickinson; bpo-1675423(2).) * Python’s C API now includes two functions for case-insensitive string comparisons, ‘PyOS_stricmp(char*, char*)’ and ‘PyOS_strnicmp(char*, char*, Py_ssize_t)’. (Contributed by Christian Heimes; bpo-1635(3).) * Many C extensions define their own little macro for adding integers and strings to the module’s dictionary in the ‘init*’ function. Python 2.6 finally defines standard macros for adding values to a module, *note PyModule_AddStringMacro: d59. and ‘PyModule_AddIntMacro()’. (Contributed by Christian Heimes.) * Some macros were renamed in both 3.0 and 2.6 to make it clearer that they are macros, not functions. ‘Py_Size()’ became ‘Py_SIZE()’, ‘Py_Type()’ became ‘Py_TYPE()’, and ‘Py_Refcnt()’ became ‘Py_REFCNT()’. The mixed-case macros are still available in Python 2.6 for backward compatibility. (bpo-1629(4)) * Distutils now places C extensions it builds in a different directory when running on a debug version of Python. (Contributed by Collin Winter; bpo-1530959(5).) * Several basic data types, such as integers and strings, maintain internal free lists of objects that can be re-used. The data structures for these free lists now follow a naming convention: the variable is always named ‘free_list’, the counter is always named ‘numfree’, and a macro ‘Py_MAXFREELIST’ is always defined. * A new Makefile target, “make patchcheck”, prepares the Python source tree for making a patch: it fixes trailing whitespace in all modified ‘.py’ files, checks whether the documentation has been changed, and reports whether the ‘Misc/ACKS’ and ‘Misc/NEWS’ files have been updated. (Contributed by Brett Cannon.) Another new target, “make profile-opt”, compiles a Python binary using GCC’s profile-guided optimization. It compiles Python with profiling enabled, runs the test suite to obtain a set of profiling results, and then compiles using these results for optimization. (Contributed by Gregory P. Smith.) * Menu: * Port-Specific Changes; Windows: Port-Specific Changes Windows<2>. * Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X<2>. * Port-Specific Changes; IRIX: Port-Specific Changes IRIX. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1534 (2) https://bugs.python.org/issue1675423 (3) https://bugs.python.org/issue1635 (4) https://bugs.python.org/issue1629 (5) https://bugs.python.org/issue1530959  File: python.info, Node: Port-Specific Changes Windows<2>, Next: Port-Specific Changes Mac OS X<2>, Up: Build and C API Changes<9> 1.11.20.1 Port-Specific Changes: Windows ........................................ * The support for Windows 95, 98, ME and NT4 has been dropped. Python 2.6 requires at least Windows 2000 SP4. * The new default compiler on Windows is Visual Studio 2008 (version 9.0). The build directories for Visual Studio 2003 (version 7.1) and 2005 (version 8.0) were moved into the PC/ directory. The new ‘PCbuild’ directory supports cross compilation for X64, debug builds and Profile Guided Optimization (PGO). PGO builds are roughly 10% faster than normal builds. (Contributed by Christian Heimes with help from Amaury Forgeot d’Arc and Martin von Löwis.) * The *note msvcrt: b6. module now supports both the normal and wide char variants of the console I/O API. The ‘getwch()’ function reads a keypress and returns a Unicode value, as does the ‘getwche()’ function. The ‘putwch()’ function takes a Unicode character and writes it to the console. (Contributed by Christian Heimes.) * *note os.path.expandvars(): d44. will now expand environment variables in the form “%var%”, and “~user” will be expanded into the user’s home directory path. (Contributed by Josiah Carlson; bpo-957650(1).) * The *note socket: ef. module’s socket objects now have an ‘ioctl()’ method that provides a limited interface to the ‘WSAIoctl()’ system interface. * The ‘_winreg’ module now has a function, ‘ExpandEnvironmentStrings()’, that expands environment variable references such as ‘%NAME%’ in an input string. The handle objects provided by this module now support the context protocol, so they can be used in *note with: 6e9. statements. (Contributed by Christian Heimes.) ‘_winreg’ also has better support for x64 systems, exposing the ‘DisableReflectionKey()’, ‘EnableReflectionKey()’, and ‘QueryReflectionKey()’ functions, which enable and disable registry reflection for 32-bit processes running on 64-bit systems. (bpo-1753245(2)) * The *note msilib: b5. module’s ‘Record’ object gained ‘GetInteger()’ and ‘GetString()’ methods that return field values as an integer or a string. (Contributed by Floris Bruynooghe; bpo-2125(3).) ---------- Footnotes ---------- (1) https://bugs.python.org/issue957650 (2) https://bugs.python.org/issue1753245 (3) https://bugs.python.org/issue2125  File: python.info, Node: Port-Specific Changes Mac OS X<2>, Next: Port-Specific Changes IRIX, Prev: Port-Specific Changes Windows<2>, Up: Build and C API Changes<9> 1.11.20.2 Port-Specific Changes: Mac OS X ......................................... * When compiling a framework build of Python, you can now specify the framework name to be used by providing the ‘--with-framework-name=’ option to the ‘configure’ script. * The ‘macfs’ module has been removed. This in turn required the ‘macostools.touched()’ function to be removed because it depended on the ‘macfs’ module. (bpo-1490190(1)) * Many other Mac OS modules have been deprecated and will be removed in Python 3.0: ‘_builtinSuites’, ‘aepack’, ‘aetools’, ‘aetypes’, ‘applesingle’, ‘appletrawmain’, ‘appletrunner’, ‘argvemulator’, ‘Audio_mac’, ‘autoGIL’, ‘Carbon’, ‘cfmfile’, ‘CodeWarrior’, ‘ColorPicker’, ‘EasyDialogs’, ‘Explorer’, ‘Finder’, ‘FrameWork’, ‘findertools’, ‘ic’, ‘icglue’, ‘icopen’, ‘macerrors’, ‘MacOS’, ‘macfs’, ‘macostools’, ‘macresource’, ‘MiniAEFrame’, ‘Nav’, ‘Netscape’, ‘OSATerminology’, ‘pimp’, ‘PixMapWrapper’, ‘StdSuites’, ‘SystemEvents’, ‘Terminal’, and ‘terminalcommand’. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1490190  File: python.info, Node: Port-Specific Changes IRIX, Prev: Port-Specific Changes Mac OS X<2>, Up: Build and C API Changes<9> 1.11.20.3 Port-Specific Changes: IRIX ..................................... A number of old IRIX-specific modules were deprecated and will be removed in Python 3.0: ‘al’ and ‘AL’, ‘cd’, ‘cddb’, ‘cdplayer’, ‘CL’ and ‘cl’, ‘DEVICE’, ‘ERRNO’, ‘FILE’, ‘FL’ and ‘fl’, ‘flp’, ‘fm’, ‘GET’, ‘GLWS’, ‘GL’ and ‘gl’, ‘IN’, ‘IOCTL’, ‘jpeg’, ‘panelparser’, ‘readcd’, ‘SV’ and ‘sv’, ‘torgb’, ‘videoreader’, and ‘WAIT’.  File: python.info, Node: Porting to Python 2 6, Next: Acknowledgements<2>, Prev: Build and C API Changes<9>, Up: What’s New in Python 2 6 1.11.21 Porting to Python 2.6 ----------------------------- This section lists previously described changes and other bugfixes that may require changes to your code: * Classes that aren’t supposed to be hashable should set ‘__hash__ = None’ in their definitions to indicate the fact. * String exceptions have been removed. Attempting to use them raises a *note TypeError: 192. * The *note __init__(): d5e. method of *note collections.deque: 531. now clears any existing contents of the deque before adding elements from the iterable. This change makes the behavior match ‘list.__init__()’. * *note object.__init__(): d5e. previously accepted arbitrary arguments and keyword arguments, ignoring them. In Python 2.6, this is no longer allowed and will result in a *note TypeError: 192. This will affect *note __init__(): d5e. methods that end up calling the corresponding method on *note object: 2b0. (perhaps through using *note super(): 4e2.). See bpo-1683368(1) for discussion. * The ‘Decimal’ constructor now accepts leading and trailing whitespace when passed a string. Previously it would raise an ‘InvalidOperation’ exception. On the other hand, the ‘create_decimal()’ method of ‘Context’ objects now explicitly disallows extra whitespace, raising a ‘ConversionSyntax’ exception. * Due to an implementation accident, if you passed a file path to the built-in *note __import__(): 610. function, it would actually import the specified file. This was never intended to work, however, and the implementation now explicitly checks for this case and raises an *note ImportError: 334. * C API: the *note PyImport_Import(): d5f. and *note PyImport_ImportModule(): c73. functions now default to absolute imports, not relative imports. This will affect C extensions that import other modules. * C API: extension data types that shouldn’t be hashable should define their ‘tp_hash’ slot to *note PyObject_HashNotImplemented(): d31. * The *note socket: ef. module exception *note socket.error: 995. now inherits from *note IOError: 992. Previously it wasn’t a subclass of ‘StandardError’ but now it is, through *note IOError: 992. (Implemented by Gregory P. Smith; bpo-1706815(2).) * The ‘xmlrpclib’ module no longer automatically converts *note datetime.date: 193. and *note datetime.time: 4f3. to the ‘xmlrpclib.DateTime’ type; the conversion semantics were not necessarily correct for all applications. Code using ‘xmlrpclib’ should convert ‘date’ and *note time: 4f3. instances. (bpo-1330538(3)) * (3.0-warning mode) The *note Exception: 1a9. class now warns when accessed using slicing or index access; having *note Exception: 1a9. behave like a tuple is being phased out. * (3.0-warning mode) inequality comparisons between two dictionaries or two objects that don’t implement comparison methods are reported as warnings. ‘dict1 == dict2’ still works, but ‘dict1 < dict2’ is being phased out. Comparisons between cells, which are an implementation detail of Python’s scoping rules, also cause warnings because such comparisons are forbidden entirely in 3.0. ---------- Footnotes ---------- (1) https://bugs.python.org/issue1683368 (2) https://bugs.python.org/issue1706815 (3) https://bugs.python.org/issue1330538  File: python.info, Node: Acknowledgements<2>, Prev: Porting to Python 2 6, Up: What’s New in Python 2 6 1.11.22 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Georg Brandl, Steve Brown, Nick Coghlan, Ralph Corderoy, Jim Jewett, Kent Johnson, Chris Lambacher, Martin Michlmayr, Antoine Pitrou, Brian Warner.  File: python.info, Node: What’s New in Python 2 5, Next: What’s New in Python 2 4, Prev: What’s New in Python 2 6, Up: What’s New in Python 1.12 What’s New in Python 2.5 ============================= Author: A.M. Kuchling This article explains the new features in Python 2.5. The final release of Python 2.5 is scheduled for August 2006; PEP 356(1) describes the planned release schedule. The changes in Python 2.5 are an interesting mix of language and library improvements. The library enhancements will be more important to Python’s user community, I think, because several widely-useful packages were added. New modules include ElementTree for XML processing (‘xml.etree’), the SQLite database module (‘sqlite’), and the *note ctypes: 2b. module for calling C functions. The language changes are of middling significance. Some pleasant new features were added, but most of them aren’t features that you’ll use every day. Conditional expressions were finally added to the language using a novel syntax; see section *note PEP 308; Conditional Expressions: d64. The new ‘*note with: 6e9.’ statement will make writing cleanup code easier (section *note PEP 343; The ‘with’ statement: d65.). Values can now be passed into generators (section *note PEP 342; New Generator Features: d66.). Imports are now visible as either absolute or relative (section *note PEP 328; Absolute and Relative Imports: d67.). Some corner cases of exception handling are handled better (section *note PEP 341; Unified try/except/finally: d68.). All these improvements are worthwhile, but they’re improvements to one specific language feature or another; none of them are broad modifications to Python’s semantics. As well as the language and library additions, other improvements and bugfixes were made throughout the source tree. A search through the SVN change logs finds there were 353 patches applied and 458 bugs fixed between Python 2.4 and 2.5. (Both figures are likely to be underestimates.) This article doesn’t try to be a complete specification of the new features; instead changes are briefly introduced using helpful examples. For full details, you should always refer to the documentation for Python 2.5 at ‘https://docs.python.org’. If you want to understand the complete implementation and design rationale, refer to the PEP for a particular new feature. Comments, suggestions, and error reports for this document are welcome; please e-mail them to the author or open a bug in the Python bug tracker. * Menu: * PEP 308; Conditional Expressions: PEP 308 Conditional Expressions. * PEP 309; Partial Function Application: PEP 309 Partial Function Application. * PEP 314; Metadata for Python Software Packages v1.1: PEP 314 Metadata for Python Software Packages v1 1. * PEP 328; Absolute and Relative Imports: PEP 328 Absolute and Relative Imports. * PEP 338; Executing Modules as Scripts: PEP 338 Executing Modules as Scripts. * PEP 341; Unified try/except/finally: PEP 341 Unified try/except/finally. * PEP 342; New Generator Features: PEP 342 New Generator Features. * PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement<2>. * PEP 352; Exceptions as New-Style Classes: PEP 352 Exceptions as New-Style Classes. * PEP 353; Using ssize_t as the index type: PEP 353 Using ssize_t as the index type. * PEP 357; The ‘__index__’ method: PEP 357 The ‘__index__’ method. * Other Language Changes: Other Language Changes<11>. * New, Improved, and Removed Modules: New Improved and Removed Modules. * Build and C API Changes: Build and C API Changes<10>. * Porting to Python 2.5: Porting to Python 2 5. * Acknowledgements: Acknowledgements<3>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0356  File: python.info, Node: PEP 308 Conditional Expressions, Next: PEP 309 Partial Function Application, Up: What’s New in Python 2 5 1.12.1 PEP 308: Conditional Expressions --------------------------------------- For a long time, people have been requesting a way to write conditional expressions, which are expressions that return value A or value B depending on whether a Boolean value is true or false. A conditional expression lets you write a single assignment statement that has the same effect as the following: if condition: x = true_value else: x = false_value There have been endless tedious discussions of syntax on both python-dev and comp.lang.python. A vote was even held that found the majority of voters wanted conditional expressions in some form, but there was no syntax that was preferred by a clear majority. Candidates included C’s ‘cond ? true_v : false_v’, ‘if cond then true_v else false_v’, and 16 other variations. Guido van Rossum eventually chose a surprising syntax: x = true_value if condition else false_value Evaluation is still lazy as in existing Boolean expressions, so the order of evaluation jumps around a bit. The `condition' expression in the middle is evaluated first, and the `true_value' expression is evaluated only if the condition was true. Similarly, the `false_value' expression is only evaluated when the condition is false. This syntax may seem strange and backwards; why does the condition go in the `middle' of the expression, and not in the front as in C’s ‘c ? x : y’? The decision was checked by applying the new syntax to the modules in the standard library and seeing how the resulting code read. In many cases where a conditional expression is used, one value seems to be the ‘common case’ and one value is an ‘exceptional case’, used only on rarer occasions when the condition isn’t met. The conditional syntax makes this pattern a bit more obvious: contents = ((doc + '\n') if doc else '') I read the above statement as meaning “here `contents' is usually assigned a value of ‘doc+'\n'’; sometimes `doc' is empty, in which special case an empty string is returned.” I doubt I will use conditional expressions very often where there isn’t a clear common and uncommon case. There was some discussion of whether the language should require surrounding conditional expressions with parentheses. The decision was made to `not' require parentheses in the Python language’s grammar, but as a matter of style I think you should always use them. Consider these two statements: # First version -- no parens level = 1 if logging else 0 # Second version -- with parens level = (1 if logging else 0) In the first version, I think a reader’s eye might group the statement into ‘level = 1’, ‘if logging’, ‘else 0’, and think that the condition decides whether the assignment to `level' is performed. The second version reads better, in my opinion, because it makes it clear that the assignment is always performed and the choice is being made between two values. Another reason for including the brackets: a few odd combinations of list comprehensions and lambdas could look like incorrect conditional expressions. See PEP 308(1) for some examples. If you put parentheses around your conditional expressions, you won’t run into this case. See also ........ PEP 308(2) - Conditional Expressions PEP written by Guido van Rossum and Raymond D. Hettinger; implemented by Thomas Wouters. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0308 (2) https://www.python.org/dev/peps/pep-0308  File: python.info, Node: PEP 309 Partial Function Application, Next: PEP 314 Metadata for Python Software Packages v1 1, Prev: PEP 308 Conditional Expressions, Up: What’s New in Python 2 5 1.12.2 PEP 309: Partial Function Application -------------------------------------------- The *note functools: 85. module is intended to contain tools for functional-style programming. One useful tool in this module is the ‘partial()’ function. For programs written in a functional style, you’ll sometimes want to construct variants of existing functions that have some of the parameters filled in. Consider a Python function ‘f(a, b, c)’; you could create a new function ‘g(b, c)’ that was equivalent to ‘f(1, b, c)’. This is called “partial function application”. ‘partial()’ takes the arguments ‘(function, arg1, arg2, ... kwarg1=value1, kwarg2=value2)’. The resulting object is callable, so you can just call it to invoke `function' with the filled-in arguments. Here’s a small but realistic example: import functools def log (message, subsystem): "Write the contents of 'message' to the specified subsystem." print '%s: %s' % (subsystem, message) ... server_log = functools.partial(log, subsystem='server') server_log('Unable to open socket') Here’s another example, from a program that uses PyGTK. Here a context-sensitive pop-up menu is being constructed dynamically. The callback provided for the menu option is a partially applied version of the ‘open_item()’ method, where the first argument has been provided. ... class Application: def open_item(self, path): ... def init (self): open_func = functools.partial(self.open_item, item_path) popup_menu.append( ("Open", open_func, 1) ) Another function in the *note functools: 85. module is the ‘update_wrapper(wrapper, wrapped)’ function that helps you write well-behaved decorators. ‘update_wrapper()’ copies the name, module, and docstring attribute to a wrapper function so that tracebacks inside the wrapped function are easier to understand. For example, you might write: def my_decorator(f): def wrapper(*args, **kwds): print 'Calling decorated function' return f(*args, **kwds) functools.update_wrapper(wrapper, f) return wrapper ‘wraps()’ is a decorator that can be used inside your own decorators to copy the wrapped function’s information. An alternate version of the previous example would be: def my_decorator(f): @functools.wraps(f) def wrapper(*args, **kwds): print 'Calling decorated function' return f(*args, **kwds) return wrapper See also ........ PEP 309(1) - Partial Function Application PEP proposed and written by Peter Harris; implemented by Hye-Shik Chang and Nick Coghlan, with adaptations by Raymond Hettinger. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0309  File: python.info, Node: PEP 314 Metadata for Python Software Packages v1 1, Next: PEP 328 Absolute and Relative Imports, Prev: PEP 309 Partial Function Application, Up: What’s New in Python 2 5 1.12.3 PEP 314: Metadata for Python Software Packages v1.1 ---------------------------------------------------------- Some simple dependency support was added to Distutils. The ‘setup()’ function now has ‘requires’, ‘provides’, and ‘obsoletes’ keyword parameters. When you build a source distribution using the ‘sdist’ command, the dependency information will be recorded in the ‘PKG-INFO’ file. Another new keyword parameter is ‘download_url’, which should be set to a URL for the package’s source code. This means it’s now possible to look up an entry in the package index, determine the dependencies for a package, and download the required packages. VERSION = '1.0' setup(name='PyPackage', version=VERSION, requires=['numarray', 'zlib (>=1.1.4)'], obsoletes=['OldPackage'] download_url=('http://www.example.com/pypackage/dist/pkg-%s.tar.gz' % VERSION), ) Another new enhancement to the Python package index at ‘https://pypi.org’ is storing source and binary archives for a package. The new ‘upload’ Distutils command will upload a package to the repository. Before a package can be uploaded, you must be able to build a distribution using the ‘sdist’ Distutils command. Once that works, you can run ‘python setup.py upload’ to add your package to the PyPI archive. Optionally you can GPG-sign the package by supplying the ‘--sign’ and ‘--identity’ options. Package uploading was implemented by Martin von Löwis and Richard Jones. See also ........ PEP 314(1) - Metadata for Python Software Packages v1.1 PEP proposed and written by A.M. Kuchling, Richard Jones, and Fred Drake; implemented by Richard Jones and Fred Drake. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0314  File: python.info, Node: PEP 328 Absolute and Relative Imports, Next: PEP 338 Executing Modules as Scripts, Prev: PEP 314 Metadata for Python Software Packages v1 1, Up: What’s New in Python 2 5 1.12.4 PEP 328: Absolute and Relative Imports --------------------------------------------- The simpler part of PEP 328(1) was implemented in Python 2.4: parentheses could now be used to enclose the names imported from a module using the ‘from ... import ...’ statement, making it easier to import many different names. The more complicated part has been implemented in Python 2.5: importing a module can be specified to use absolute or package-relative imports. The plan is to move toward making absolute imports the default in future versions of Python. Let’s say you have a package directory like this: pkg/ pkg/__init__.py pkg/main.py pkg/string.py This defines a package named ‘pkg’ containing the ‘pkg.main’ and ‘pkg.string’ submodules. Consider the code in the ‘main.py’ module. What happens if it executes the statement ‘import string’? In Python 2.4 and earlier, it will first look in the package’s directory to perform a relative import, finds ‘pkg/string.py’, imports the contents of that file as the ‘pkg.string’ module, and that module is bound to the name ‘string’ in the ‘pkg.main’ module’s namespace. That’s fine if ‘pkg.string’ was what you wanted. But what if you wanted Python’s standard *note string: f6. module? There’s no clean way to ignore ‘pkg.string’ and look for the standard module; generally you had to look at the contents of ‘sys.modules’, which is slightly unclean. Holger Krekel’s ‘py.std’ package provides a tidier way to perform imports from the standard library, ‘import py; py.std.string.join()’, but that package isn’t available on all Python installations. Reading code which relies on relative imports is also less clear, because a reader may be confused about which module, *note string: f6. or ‘pkg.string’, is intended to be used. Python users soon learned not to duplicate the names of standard library modules in the names of their packages’ submodules, but you can’t protect against having your submodule’s name being used for a new module added in a future version of Python. In Python 2.5, you can switch *note import: c1d.’s behaviour to absolute imports using a ‘from __future__ import absolute_import’ directive. This absolute-import behaviour will become the default in a future version (probably Python 2.7). Once absolute imports are the default, ‘import string’ will always find the standard library’s version. It’s suggested that users should begin using absolute imports as much as possible, so it’s preferable to begin writing ‘from pkg import string’ in your code. Relative imports are still possible by adding a leading period to the module name when using the ‘from ... import’ form: # Import names from pkg.string from .string import name1, name2 # Import pkg.string from . import string This imports the *note string: f6. module relative to the current package, so in ‘pkg.main’ this will import `name1' and `name2' from ‘pkg.string’. Additional leading periods perform the relative import starting from the parent of the current package. For example, code in the ‘A.B.C’ module can do: from . import D # Imports A.B.D from .. import E # Imports A.E from ..F import G # Imports A.F.G Leading periods cannot be used with the ‘import modname’ form of the import statement, only the ‘from ... import’ form. See also ........ PEP 328(2) - Imports: Multi-Line and Absolute/Relative PEP written by Aahz; implemented by Thomas Wouters. ‘https://pylib.readthedocs.io/’ The py library by Holger Krekel, which contains the ‘py.std’ package. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0328 (2) https://www.python.org/dev/peps/pep-0328  File: python.info, Node: PEP 338 Executing Modules as Scripts, Next: PEP 341 Unified try/except/finally, Prev: PEP 328 Absolute and Relative Imports, Up: What’s New in Python 2 5 1.12.5 PEP 338: Executing Modules as Scripts -------------------------------------------- The *note -m: 337. switch added in Python 2.4 to execute a module as a script gained a few more abilities. Instead of being implemented in C code inside the Python interpreter, the switch now uses an implementation in a new module, *note runpy: e2. The *note runpy: e2. module implements a more sophisticated import mechanism so that it’s now possible to run modules in a package such as ‘pychecker.checker’. The module also supports alternative import mechanisms such as the *note zipimport: 143. module. This means you can add a .zip archive’s path to ‘sys.path’ and then use the *note -m: 337. switch to execute code from the archive. See also ........ PEP 338(1) - Executing modules as scripts PEP written and implemented by Nick Coghlan. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0338  File: python.info, Node: PEP 341 Unified try/except/finally, Next: PEP 342 New Generator Features, Prev: PEP 338 Executing Modules as Scripts, Up: What’s New in Python 2 5 1.12.6 PEP 341: Unified try/except/finally ------------------------------------------ Until Python 2.5, the *note try: d72. statement came in two flavours. You could use a *note finally: 182. block to ensure that code is always executed, or one or more *note except: b3e. blocks to catch specific exceptions. You couldn’t combine both ‘except’ blocks and a ‘finally’ block, because generating the right bytecode for the combined version was complicated and it wasn’t clear what the semantics of the combined statement should be. Guido van Rossum spent some time working with Java, which does support the equivalent of combining *note except: b3e. blocks and a *note finally: 182. block, and this clarified what the statement should mean. In Python 2.5, you can now write: try: block-1 ... except Exception1: handler-1 ... except Exception2: handler-2 ... else: else-block finally: final-block The code in `block-1' is executed. If the code raises an exception, the various *note except: b3e. blocks are tested: if the exception is of class ‘Exception1’, `handler-1' is executed; otherwise if it’s of class ‘Exception2’, `handler-2' is executed, and so forth. If no exception is raised, the `else-block' is executed. No matter what happened previously, the `final-block' is executed once the code block is complete and any raised exceptions handled. Even if there’s an error in an exception handler or the `else-block' and a new exception is raised, the code in the `final-block' is still run. See also ........ PEP 341(1) - Unifying try-except and try-finally PEP written by Georg Brandl; implementation by Thomas Lee. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0341  File: python.info, Node: PEP 342 New Generator Features, Next: PEP 343 The ‘with’ statement<2>, Prev: PEP 341 Unified try/except/finally, Up: What’s New in Python 2 5 1.12.7 PEP 342: New Generator Features -------------------------------------- Python 2.5 adds a simple way to pass values `into' a generator. As introduced in Python 2.3, generators only produce output; once a generator’s code was invoked to create an iterator, there was no way to pass any new information into the function when its execution is resumed. Sometimes the ability to pass in some information would be useful. Hackish solutions to this include making the generator’s code look at a global variable and then changing the global variable’s value, or passing in some mutable object that callers then modify. To refresh your memory of basic generators, here’s a simple example: def counter (maximum): i = 0 while i < maximum: yield i i += 1 When you call ‘counter(10)’, the result is an iterator that returns the values from 0 up to 9. On encountering the *note yield: 18f. statement, the iterator returns the provided value and suspends the function’s execution, preserving the local variables. Execution resumes on the following call to the iterator’s *note next(): 682. method, picking up after the ‘yield’ statement. In Python 2.3, *note yield: 18f. was a statement; it didn’t return any value. In 2.5, ‘yield’ is now an expression, returning a value that can be assigned to a variable or otherwise operated on: val = (yield i) I recommend that you always put parentheses around a *note yield: 18f. expression when you’re doing something with the returned value, as in the above example. The parentheses aren’t always necessary, but it’s easier to always add them instead of having to remember when they’re needed. ( PEP 342(1) explains the exact rules, which are that a *note yield: 18f.-expression must always be parenthesized except when it occurs at the top-level expression on the right-hand side of an assignment. This means you can write ‘val = yield i’ but have to use parentheses when there’s an operation, as in ‘val = (yield i) + 12’.) Values are sent into a generator by calling its ‘send(value)’ method. The generator’s code is then resumed and the *note yield: 18f. expression returns the specified `value'. If the regular *note next(): 682. method is called, the ‘yield’ returns *note None: 157. Here’s the previous example, modified to allow changing the value of the internal counter. def counter (maximum): i = 0 while i < maximum: val = (yield i) # If value provided, change counter if val is not None: i = val else: i += 1 And here’s an example of changing the counter: >>> it = counter(10) >>> print it.next() 0 >>> print it.next() 1 >>> print it.send(8) 8 >>> print it.next() 9 >>> print it.next() Traceback (most recent call last): File "t.py", line 15, in ? print it.next() StopIteration *note yield: 18f. will usually return *note None: 157, so you should always check for this case. Don’t just use its value in expressions unless you’re sure that the ‘send()’ method will be the only method used to resume your generator function. In addition to ‘send()’, there are two other new methods on generators: * ‘throw(type, value=None, traceback=None)’ is used to raise an exception inside the generator; the exception is raised by the *note yield: 18f. expression where the generator’s execution is paused. * ‘close()’ raises a new *note GeneratorExit: d32. exception inside the generator to terminate the iteration. On receiving this exception, the generator’s code must either raise *note GeneratorExit: d32. or *note StopIteration: 486. Catching the *note GeneratorExit: d32. exception and returning a value is illegal and will trigger a *note RuntimeError: 2ba.; if the function raises some other exception, that exception is propagated to the caller. ‘close()’ will also be called by Python’s garbage collector when the generator is garbage-collected. If you need to run cleanup code when a *note GeneratorExit: d32. occurs, I suggest using a ‘try: ... finally:’ suite instead of catching *note GeneratorExit: d32. The cumulative effect of these changes is to turn generators from one-way producers of information into both producers and consumers. Generators also become `coroutines', a more generalized form of subroutines. Subroutines are entered at one point and exited at another point (the top of the function, and a *note return: 190. statement), but coroutines can be entered, exited, and resumed at many different points (the *note yield: 18f. statements). We’ll have to figure out patterns for using coroutines effectively in Python. The addition of the ‘close()’ method has one side effect that isn’t obvious. ‘close()’ is called when a generator is garbage-collected, so this means the generator’s code gets one last chance to run before the generator is destroyed. This last chance means that ‘try...finally’ statements in generators can now be guaranteed to work; the *note finally: 182. clause will now always get a chance to run. The syntactic restriction that you couldn’t mix *note yield: 18f. statements with a ‘try...finally’ suite has therefore been removed. This seems like a minor bit of language trivia, but using generators and ‘try...finally’ is actually necessary in order to implement the *note with: 6e9. statement described by PEP 343(2). I’ll look at this new statement in the following section. Another even more esoteric effect of this change: previously, the ‘gi_frame’ attribute of a generator was always a frame object. It’s now possible for ‘gi_frame’ to be ‘None’ once the generator has been exhausted. See also ........ PEP 342(3) - Coroutines via Enhanced Generators PEP written by Guido van Rossum and Phillip J. Eby; implemented by Phillip J. Eby. Includes examples of some fancier uses of generators as coroutines. Earlier versions of these features were proposed in PEP 288(4) by Raymond Hettinger and PEP 325(5) by Samuele Pedroni. ‘https://en.wikipedia.org/wiki/Coroutine’ The Wikipedia entry for coroutines. ‘http://www.sidhe.org/~dan/blog/archives/000178.html’ An explanation of coroutines from a Perl point of view, written by Dan Sugalski. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0342 (2) https://www.python.org/dev/peps/pep-0343 (3) https://www.python.org/dev/peps/pep-0342 (4) https://www.python.org/dev/peps/pep-0288 (5) https://www.python.org/dev/peps/pep-0325  File: python.info, Node: PEP 343 The ‘with’ statement<2>, Next: PEP 352 Exceptions as New-Style Classes, Prev: PEP 342 New Generator Features, Up: What’s New in Python 2 5 1.12.8 PEP 343: The ‘with’ statement ------------------------------------ The ‘*note with: 6e9.’ statement clarifies code that previously would use ‘try...finally’ blocks to ensure that clean-up code is executed. In this section, I’ll discuss the statement as it will commonly be used. In the next section, I’ll examine the implementation details and show how to write objects for use with this statement. The ‘*note with: 6e9.’ statement is a new control-flow structure whose basic structure is: with expression [as variable]: with-block The expression is evaluated, and it should result in an object that supports the context management protocol (that is, has *note __enter__(): c95. and *note __exit__(): c96. methods. The object’s *note __enter__(): c95. is called before `with-block' is executed and therefore can run set-up code. It also may return a value that is bound to the name `variable', if given. (Note carefully that `variable' is `not' assigned the result of `expression'.) After execution of the `with-block' is finished, the object’s *note __exit__(): c96. method is called, even if the block raised an exception, and can therefore run clean-up code. To enable the statement in Python 2.5, you need to add the following directive to your module: from __future__ import with_statement The statement will always be enabled in Python 2.6. Some standard Python objects now support the context management protocol and can be used with the ‘*note with: 6e9.’ statement. File objects are one example: with open('/etc/passwd', 'r') as f: for line in f: print line ... more processing code ... After this statement has executed, the file object in `f' will have been automatically closed, even if the *note for: c30. loop raised an exception part-way through the block. Note: In this case, `f' is the same object created by *note open(): 4f0, because ‘file.__enter__()’ returns `self'. The *note threading: 109. module’s locks and condition variables also support the ‘*note with: 6e9.’ statement: lock = threading.Lock() with lock: # Critical section of code ... The lock is acquired before the block is executed and always released once the block is complete. The new ‘localcontext()’ function in the *note decimal: 36. module makes it easy to save and restore the current decimal context, which encapsulates the desired precision and rounding characteristics for computations: from decimal import Decimal, Context, localcontext # Displays with default precision of 28 digits v = Decimal('578') print v.sqrt() with localcontext(Context(prec=16)): # All code in this block uses a precision of 16 digits. # The original context is restored on exiting the block. print v.sqrt() * Menu: * Writing Context Managers: Writing Context Managers<2>. * The contextlib module: The contextlib module<2>.  File: python.info, Node: Writing Context Managers<2>, Next: The contextlib module<2>, Up: PEP 343 The ‘with’ statement<2> 1.12.8.1 Writing Context Managers ................................. Under the hood, the ‘*note with: 6e9.’ statement is fairly complicated. Most people will only use ‘‘with’’ in company with existing objects and don’t need to know these details, so you can skip the rest of this section if you like. Authors of new objects will need to understand the details of the underlying implementation and should keep reading. A high-level explanation of the context management protocol is: * The expression is evaluated and should result in an object called a “context manager”. The context manager must have *note __enter__(): c95. and *note __exit__(): c96. methods. * The context manager’s *note __enter__(): c95. method is called. The value returned is assigned to `VAR'. If no ‘'as VAR'’ clause is present, the value is simply discarded. * The code in `BLOCK' is executed. * If `BLOCK' raises an exception, the ‘__exit__(type, value, traceback)’ is called with the exception details, the same values returned by *note sys.exc_info(): c5f. The method’s return value controls whether the exception is re-raised: any false value re-raises the exception, and ‘True’ will result in suppressing it. You’ll only rarely want to suppress the exception, because if you do the author of the code containing the ‘*note with: 6e9.’ statement will never realize anything went wrong. * If `BLOCK' didn’t raise an exception, the *note __exit__(): c96. method is still called, but `type', `value', and `traceback' are all ‘None’. Let’s think through an example. I won’t present detailed code but will only sketch the methods necessary for a database that supports transactions. (For people unfamiliar with database terminology: a set of changes to the database are grouped into a transaction. Transactions can be either committed, meaning that all the changes are written into the database, or rolled back, meaning that the changes are all discarded and the database is unchanged. See any database textbook for more information.) Let’s assume there’s an object representing a database connection. Our goal will be to let the user write code like this: db_connection = DatabaseConnection() with db_connection as cursor: cursor.execute('insert into ...') cursor.execute('delete from ...') # ... more operations ... The transaction should be committed if the code in the block runs flawlessly or rolled back if there’s an exception. Here’s the basic interface for ‘DatabaseConnection’ that I’ll assume: class DatabaseConnection: # Database interface def cursor (self): "Returns a cursor object and starts a new transaction" def commit (self): "Commits current transaction" def rollback (self): "Rolls back current transaction" The *note __enter__(): c95. method is pretty easy, having only to start a new transaction. For this application the resulting cursor object would be a useful result, so the method will return it. The user can then add ‘as cursor’ to their ‘*note with: 6e9.’ statement to bind the cursor to a variable name. class DatabaseConnection: ... def __enter__ (self): # Code to start a new transaction cursor = self.cursor() return cursor The *note __exit__(): c96. method is the most complicated because it’s where most of the work has to be done. The method has to check if an exception occurred. If there was no exception, the transaction is committed. The transaction is rolled back if there was an exception. In the code below, execution will just fall off the end of the function, returning the default value of ‘None’. ‘None’ is false, so the exception will be re-raised automatically. If you wished, you could be more explicit and add a *note return: 190. statement at the marked location. class DatabaseConnection: ... def __exit__ (self, type, value, tb): if tb is None: # No exception, so commit self.commit() else: # Exception occurred, so rollback. self.rollback() # return False  File: python.info, Node: The contextlib module<2>, Prev: Writing Context Managers<2>, Up: PEP 343 The ‘with’ statement<2> 1.12.8.2 The contextlib module .............................. The new *note contextlib: 24. module provides some functions and a decorator that are useful for writing objects for use with the ‘*note with: 6e9.’ statement. The decorator is called ‘contextmanager()’, and lets you write a single generator function instead of defining a new class. The generator should yield exactly one value. The code up to the *note yield: 18f. will be executed as the *note __enter__(): c95. method, and the value yielded will be the method’s return value that will get bound to the variable in the ‘*note with: 6e9.’ statement’s ‘as’ clause, if any. The code after the *note yield: 18f. will be executed in the *note __exit__(): c96. method. Any exception raised in the block will be raised by the ‘yield’ statement. Our database example from the previous section could be written using this decorator as: from contextlib import contextmanager @contextmanager def db_transaction (connection): cursor = connection.cursor() try: yield cursor except: connection.rollback() raise else: connection.commit() db = DatabaseConnection() with db_transaction(db) as cursor: ... The *note contextlib: 24. module also has a ‘nested(mgr1, mgr2, ...)’ function that combines a number of context managers so you don’t need to write nested ‘*note with: 6e9.’ statements. In this example, the single ‘‘with’’ statement both starts a database transaction and acquires a thread lock: lock = threading.Lock() with nested (db_transaction(db), lock) as (cursor, locked): ... Finally, the ‘closing(object)’ function returns `object' so that it can be bound to a variable, and calls ‘object.close’ at the end of the block. import urllib, sys from contextlib import closing with closing(urllib.urlopen('http://www.yahoo.com')) as f: for line in f: sys.stdout.write(line) See also ........ PEP 343(1) - The “with” statement PEP written by Guido van Rossum and Nick Coghlan; implemented by Mike Bland, Guido van Rossum, and Neal Norwitz. The PEP shows the code generated for a ‘*note with: 6e9.’ statement, which can be helpful in learning how the statement works. The documentation for the *note contextlib: 24. module. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0343  File: python.info, Node: PEP 352 Exceptions as New-Style Classes, Next: PEP 353 Using ssize_t as the index type, Prev: PEP 343 The ‘with’ statement<2>, Up: What’s New in Python 2 5 1.12.9 PEP 352: Exceptions as New-Style Classes ----------------------------------------------- Exception classes can now be new-style classes, not just classic classes, and the built-in *note Exception: 1a9. class and all the standard built-in exceptions (*note NameError: d7b, *note ValueError: 1fb, etc.) are now new-style classes. The inheritance hierarchy for exceptions has been rearranged a bit. In 2.5, the inheritance relationships are: BaseException # New in Python 2.5 |- KeyboardInterrupt |- SystemExit |- Exception |- (all other current built-in exceptions) This rearrangement was done because people often want to catch all exceptions that indicate program errors. *note KeyboardInterrupt: 197. and *note SystemExit: 5fc. aren’t errors, though, and usually represent an explicit action such as the user hitting ‘Control-C’ or code calling *note sys.exit(): ce2. A bare ‘except:’ will catch all exceptions, so you commonly need to list *note KeyboardInterrupt: 197. and *note SystemExit: 5fc. in order to re-raise them. The usual pattern is: try: ... except (KeyboardInterrupt, SystemExit): raise except: # Log error... # Continue running program... In Python 2.5, you can now write ‘except Exception’ to achieve the same result, catching all the exceptions that usually indicate errors but leaving *note KeyboardInterrupt: 197. and *note SystemExit: 5fc. alone. As in previous versions, a bare ‘except:’ still catches all exceptions. The goal for Python 3.0 is to require any class raised as an exception to derive from *note BaseException: 1a8. or some descendant of *note BaseException: 1a8, and future releases in the Python 2.x series may begin to enforce this constraint. Therefore, I suggest you begin making all your exception classes derive from *note Exception: 1a9. now. It’s been suggested that the bare ‘except:’ form should be removed in Python 3.0, but Guido van Rossum hasn’t decided whether to do this or not. Raising of strings as exceptions, as in the statement ‘raise "Error occurred"’, is deprecated in Python 2.5 and will trigger a warning. The aim is to be able to remove the string-exception feature in a few releases. See also ........ PEP 352(1) - Required Superclass for Exceptions PEP written by Brett Cannon and Guido van Rossum; implemented by Brett Cannon. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0352  File: python.info, Node: PEP 353 Using ssize_t as the index type, Next: PEP 357 The ‘__index__’ method, Prev: PEP 352 Exceptions as New-Style Classes, Up: What’s New in Python 2 5 1.12.10 PEP 353: Using ssize_t as the index type ------------------------------------------------ A wide-ranging change to Python’s C API, using a new ‘Py_ssize_t’ type definition instead of ‘int’, will permit the interpreter to handle more data on 64-bit platforms. This change doesn’t affect Python’s capacity on 32-bit platforms. Various pieces of the Python interpreter used C’s ‘int’ type to store sizes or counts; for example, the number of items in a list or tuple were stored in an ‘int’. The C compilers for most 64-bit platforms still define ‘int’ as a 32-bit type, so that meant that lists could only hold up to ‘2**31 - 1’ = 2147483647 items. (There are actually a few different programming models that 64-bit C compilers can use – see ‘http://www.unix.org/version2/whatsnew/lp64_wp.html’ for a discussion – but the most commonly available model leaves ‘int’ as 32 bits.) A limit of 2147483647 items doesn’t really matter on a 32-bit platform because you’ll run out of memory before hitting the length limit. Each list item requires space for a pointer, which is 4 bytes, plus space for a *note PyObject: 4ba. representing the item. 2147483647*4 is already more bytes than a 32-bit address space can contain. It’s possible to address that much memory on a 64-bit platform, however. The pointers for a list that size would only require 16 GiB of space, so it’s not unreasonable that Python programmers might construct lists that large. Therefore, the Python interpreter had to be changed to use some type other than ‘int’, and this will be a 64-bit type on 64-bit platforms. The change will cause incompatibilities on 64-bit machines, so it was deemed worth making the transition now, while the number of 64-bit users is still relatively small. (In 5 or 10 years, we may `all' be on 64-bit machines, and the transition would be more painful then.) This change most strongly affects authors of C extension modules. Python strings and container types such as lists and tuples now use ‘Py_ssize_t’ to store their size. Functions such as *note PyList_Size(): d7e. now return ‘Py_ssize_t’. Code in extension modules may therefore need to have some variables changed to ‘Py_ssize_t’. The *note PyArg_ParseTuple(): 26a. and *note Py_BuildValue(): 2ce. functions have a new conversion code, ‘n’, for ‘Py_ssize_t’. *note PyArg_ParseTuple(): 26a.’s ‘s#’ and ‘t#’ still output ‘int’ by default, but you can define the macro ‘PY_SSIZE_T_CLEAN’ before including ‘Python.h’ to make them return ‘Py_ssize_t’. PEP 353(1) has a section on conversion guidelines that extension authors should read to learn about supporting 64-bit platforms. See also ........ PEP 353(2) - Using ssize_t as the index type PEP written and implemented by Martin von Löwis. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0353 (2) https://www.python.org/dev/peps/pep-0353  File: python.info, Node: PEP 357 The ‘__index__’ method, Next: Other Language Changes<11>, Prev: PEP 353 Using ssize_t as the index type, Up: What’s New in Python 2 5 1.12.11 PEP 357: The ‘__index__’ method --------------------------------------- The NumPy developers had a problem that could only be solved by adding a new special method, *note __index__(): 18a. When using slice notation, as in ‘[start:stop:step]’, the values of the `start', `stop', and `step' indexes must all be either integers or long integers. NumPy defines a variety of specialized integer types corresponding to unsigned and signed integers of 8, 16, 32, and 64 bits, but there was no way to signal that these types could be used as slice indexes. Slicing can’t just use the existing *note __int__(): 18b. method because that method is also used to implement coercion to integers. If slicing used *note __int__(): 18b, floating-point numbers would also become legal slice indexes and that’s clearly an undesirable behaviour. Instead, a new special method called *note __index__(): 18a. was added. It takes no arguments and returns an integer giving the slice index to use. For example: class C: def __index__ (self): return self.value The return value must be either a Python integer or long integer. The interpreter will check that the type returned is correct, and raises a *note TypeError: 192. if this requirement isn’t met. A corresponding ‘nb_index’ slot was added to the C-level *note PyNumberMethods: d81. structure to let C extensions implement this protocol. ‘PyNumber_Index(obj)’ can be used in extension code to call the *note __index__(): 18a. function and retrieve its result. See also ........ PEP 357(1) - Allowing Any Object to be Used for Slicing PEP written and implemented by Travis Oliphant. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0357  File: python.info, Node: Other Language Changes<11>, Next: New Improved and Removed Modules, Prev: PEP 357 The ‘__index__’ method, Up: What’s New in Python 2 5 1.12.12 Other Language Changes ------------------------------ Here are all of the changes that Python 2.5 makes to the core Python language. * The *note dict: 1b8. type has a new hook for letting subclasses provide a default value when a key isn’t contained in the dictionary. When a key isn’t found, the dictionary’s ‘__missing__(key)’ method will be called. This hook is used to implement the new ‘defaultdict’ class in the *note collections: 1e. module. The following example defines a dictionary that returns zero for any missing key: class zerodict (dict): def __missing__ (self, key): return 0 d = zerodict({1:1, 2:2}) print d[1], d[2] # Prints 1, 2 print d[3], d[4] # Prints 0, 0 * Both 8-bit and Unicode strings have new ‘partition(sep)’ and ‘rpartition(sep)’ methods that simplify a common use case. The ‘find(S)’ method is often used to get an index which is then used to slice the string and obtain the pieces that are before and after the separator. ‘partition(sep)’ condenses this pattern into a single method call that returns a 3-tuple containing the substring before the separator, the separator itself, and the substring after the separator. If the separator isn’t found, the first element of the tuple is the entire string and the other two elements are empty. ‘rpartition(sep)’ also returns a 3-tuple but starts searching from the end of the string; the ‘r’ stands for ‘reverse’. Some examples: >>> ('http://www.python.org').partition('://') ('http', '://', 'www.python.org') >>> ('file:/usr/share/doc/index.html').partition('://') ('file:/usr/share/doc/index.html', '', '') >>> (u'Subject: a quick question').partition(':') (u'Subject', u':', u' a quick question') >>> 'www.python.org'.rpartition('.') ('www.python', '.', 'org') >>> 'www.python.org'.rpartition(':') ('', '', 'www.python.org') (Implemented by Fredrik Lundh following a suggestion by Raymond Hettinger.) * The ‘startswith()’ and ‘endswith()’ methods of string types now accept tuples of strings to check for. def is_image_file (filename): return filename.endswith(('.gif', '.jpg', '.tiff')) (Implemented by Georg Brandl following a suggestion by Tom Lynn.) * The *note min(): 809. and *note max(): 80a. built-in functions gained a ‘key’ keyword parameter analogous to the ‘key’ argument for ‘sort()’. This parameter supplies a function that takes a single argument and is called for every value in the list; *note min(): 809./*note max(): 80a. will return the element with the smallest/largest return value from this function. For example, to find the longest string in a list, you can do: L = ['medium', 'longest', 'short'] # Prints 'longest' print max(L, key=len) # Prints 'short', because lexicographically 'short' has the largest value print max(L) (Contributed by Steven Bethard and Raymond Hettinger.) * Two new built-in functions, *note any(): d84. and *note all(): d85, evaluate whether an iterator contains any true or false values. *note any(): d84. returns *note True: 499. if any value returned by the iterator is true; otherwise it will return *note False: 388. *note all(): d85. returns *note True: 499. only if all of the values returned by the iterator evaluate as true. (Suggested by Guido van Rossum, and implemented by Raymond Hettinger.) * The result of a class’s *note __hash__(): 340. method can now be either a long integer or a regular integer. If a long integer is returned, the hash of that value is taken. In earlier versions the hash value was required to be a regular integer, but in 2.5 the *note id(): d86. built-in was changed to always return non-negative numbers, and users often seem to use ‘id(self)’ in *note __hash__(): 340. methods (though this is discouraged). * ASCII is now the default encoding for modules. It’s now a syntax error if a module contains string literals with 8-bit characters but doesn’t have an encoding declaration. In Python 2.4 this triggered a warning, not a syntax error. See PEP 263(1) for how to declare a module’s encoding; for example, you might add a line like this near the top of the source file: # -*- coding: latin1 -*- * A new warning, *note UnicodeWarning: d87, is triggered when you attempt to compare a Unicode string and an 8-bit string that can’t be converted to Unicode using the default ASCII encoding. The result of the comparison is false: >>> chr(128) == unichr(128) # Can't convert chr(128) to Unicode __main__:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False >>> chr(127) == unichr(127) # chr(127) can be converted True Previously this would raise a *note UnicodeDecodeError: 1fd. exception, but in 2.5 this could result in puzzling problems when accessing a dictionary. If you looked up ‘unichr(128)’ and ‘chr(128)’ was being used as a key, you’d get a *note UnicodeDecodeError: 1fd. exception. Other changes in 2.5 resulted in this exception being raised instead of suppressed by the code in ‘dictobject.c’ that implements dictionaries. Raising an exception for such a comparison is strictly correct, but the change might have broken code, so instead *note UnicodeWarning: d87. was introduced. (Implemented by Marc-André Lemburg.) * One error that Python programmers sometimes make is forgetting to include an ‘__init__.py’ module in a package directory. Debugging this mistake can be confusing, and usually requires running Python with the *note -v: d88. switch to log all the paths searched. In Python 2.5, a new *note ImportWarning: 5d8. warning is triggered when an import would have picked up a directory as a package but no ‘__init__.py’ was found. This warning is silently ignored by default; provide the *note -Wd: 417. option when running the Python executable to display the warning message. (Implemented by Thomas Wouters.) * The list of base classes in a class definition can now be empty. As an example, this is now legal: class C(): pass (Implemented by Brett Cannon.) * Menu: * Interactive Interpreter Changes:: * Optimizations: Optimizations<10>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0263  File: python.info, Node: Interactive Interpreter Changes, Next: Optimizations<10>, Up: Other Language Changes<11> 1.12.12.1 Interactive Interpreter Changes ......................................... In the interactive interpreter, ‘quit’ and ‘exit’ have long been strings so that new users get a somewhat helpful message when they try to quit: >>> quit 'Use Ctrl-D (i.e. EOF) to exit.' In Python 2.5, ‘quit’ and ‘exit’ are now objects that still produce string representations of themselves, but are also callable. Newbies who try ‘quit()’ or ‘exit()’ will now exit the interpreter as they expect. (Implemented by Georg Brandl.) The Python executable now accepts the standard long options *note –help: d8b. and *note –version: 5d1.; on Windows, it also accepts the *note /?: d8c. option for displaying a help message. (Implemented by Georg Brandl.)  File: python.info, Node: Optimizations<10>, Prev: Interactive Interpreter Changes, Up: Other Language Changes<11> 1.12.12.2 Optimizations ....................... Several of the optimizations were developed at the NeedForSpeed sprint, an event held in Reykjavik, Iceland, from May 21–28 2006. The sprint focused on speed enhancements to the CPython implementation and was funded by EWT LLC with local support from CCP Games. Those optimizations added at this sprint are specially marked in the following list. * When they were introduced in Python 2.4, the built-in *note set: b6f. and *note frozenset: bee. types were built on top of Python’s dictionary type. In 2.5 the internal data structure has been customized for implementing sets, and as a result sets will use a third less memory and are somewhat faster. (Implemented by Raymond Hettinger.) * The speed of some Unicode operations, such as finding substrings, string splitting, and character map encoding and decoding, has been improved. (Substring search and splitting improvements were added by Fredrik Lundh and Andrew Dalke at the NeedForSpeed sprint. Character maps were improved by Walter Dörwald and Martin von Löwis.) * The ‘long(str, base)’ function is now faster on long digit strings because fewer intermediate results are calculated. The peak is for strings of around 800–1000 digits where the function is 6 times faster. (Contributed by Alan McIntyre and committed at the NeedForSpeed sprint.) * It’s now illegal to mix iterating over a file with ‘for line in file’ and calling the file object’s ‘read()’/*note readline(): de./‘readlines()’ methods. Iteration uses an internal buffer and the ‘read*()’ methods don’t use that buffer. Instead they would return the data following the buffer, causing the data to appear out of order. Mixing iteration and these methods will now trigger a *note ValueError: 1fb. from the ‘read*()’ method. (Implemented by Thomas Wouters.) * The *note struct: f8. module now compiles structure format strings into an internal representation and caches this representation, yielding a 20% speedup. (Contributed by Bob Ippolito at the NeedForSpeed sprint.) * The *note re: dd. module got a 1 or 2% speedup by switching to Python’s allocator functions instead of the system’s ‘malloc()’ and ‘free()’. (Contributed by Jack Diederich at the NeedForSpeed sprint.) * The code generator’s peephole optimizer now performs simple constant folding in expressions. If you write something like ‘a = 2+3’, the code generator will do the arithmetic and produce code corresponding to ‘a = 5’. (Proposed and implemented by Raymond Hettinger.) * Function calls are now faster because code objects now keep the most recently finished frame (a “zombie frame”) in an internal field of the code object, reusing it the next time the code object is invoked. (Original patch by Michael Hudson, modified by Armin Rigo and Richard Jones; committed at the NeedForSpeed sprint.) Frame objects are also slightly smaller, which may improve cache locality and reduce memory usage a bit. (Contributed by Neal Norwitz.) * Python’s built-in exceptions are now new-style classes, a change that speeds up instantiation considerably. Exception handling in Python 2.5 is therefore about 30% faster than in 2.4. (Contributed by Richard Jones, Georg Brandl and Sean Reifschneider at the NeedForSpeed sprint.) * Importing now caches the paths tried, recording whether they exist or not so that the interpreter makes fewer ‘open()’ and ‘stat()’ calls on startup. (Contributed by Martin von Löwis and Georg Brandl.)  File: python.info, Node: New Improved and Removed Modules, Next: Build and C API Changes<10>, Prev: Other Language Changes<11>, Up: What’s New in Python 2 5 1.12.13 New, Improved, and Removed Modules ------------------------------------------ The standard library received many enhancements and bug fixes in Python 2.5. Here’s a partial list of the most notable changes, sorted alphabetically by module name. Consult the ‘Misc/NEWS’ file in the source tree for a more complete list of changes, or look through the SVN logs for all the details. * The *note audioop: d. module now supports the a-LAW encoding, and the code for u-LAW encoding has been improved. (Contributed by Lars Immisch.) * The *note codecs: 1c. module gained support for incremental codecs. The ‘codec.lookup()’ function now returns a ‘CodecInfo’ instance instead of a tuple. ‘CodecInfo’ instances behave like a 4-tuple to preserve backward compatibility but also have the attributes ‘encode’, ‘decode’, ‘incrementalencoder’, ‘incrementaldecoder’, ‘streamwriter’, and ‘streamreader’. Incremental codecs can receive input and produce output in multiple chunks; the output is the same as if the entire input was fed to the non-incremental codec. See the *note codecs: 1c. module documentation for details. (Designed and implemented by Walter Dörwald.) * The *note collections: 1e. module gained a new type, ‘defaultdict’, that subclasses the standard *note dict: 1b8. type. The new type mostly behaves like a dictionary but constructs a default value when a key isn’t present, automatically adding it to the dictionary for the requested key value. The first argument to ‘defaultdict’’s constructor is a factory function that gets called whenever a key is requested but not found. This factory function receives no arguments, so you can use built-in type constructors such as *note list(): 262. or *note int(): 184. For example, you can make an index of words based on their initial letter like this: words = """Nel mezzo del cammin di nostra vita mi ritrovai per una selva oscura che la diritta via era smarrita""".lower().split() index = defaultdict(list) for w in words: init_letter = w[0] index[init_letter].append(w) Printing ‘index’ results in the following output: defaultdict(, {'c': ['cammin', 'che'], 'e': ['era'], 'd': ['del', 'di', 'diritta'], 'm': ['mezzo', 'mi'], 'l': ['la'], 'o': ['oscura'], 'n': ['nel', 'nostra'], 'p': ['per'], 's': ['selva', 'smarrita'], 'r': ['ritrovai'], 'u': ['una'], 'v': ['vita', 'via']} (Contributed by Guido van Rossum.) * The ‘deque’ double-ended queue type supplied by the *note collections: 1e. module now has a ‘remove(value)’ method that removes the first occurrence of `value' in the queue, raising *note ValueError: 1fb. if the value isn’t found. (Contributed by Raymond Hettinger.) * New module: The *note contextlib: 24. module contains helper functions for use with the new ‘*note with: 6e9.’ statement. See section *note The contextlib module: d77. for more about this module. * New module: The *note cProfile: 28. module is a C implementation of the existing *note profile: d3. module that has much lower overhead. The module’s interface is the same as *note profile: d3.: you run ‘cProfile.run('main()')’ to profile a function, can save profile data to a file, etc. It’s not yet known if the Hotshot profiler, which is also written in C but doesn’t match the *note profile: d3. module’s interface, will continue to be maintained in future versions of Python. (Contributed by Armin Rigo.) Also, the *note pstats: d4. module for analyzing the data measured by the profiler now supports directing the output to any file object by supplying a `stream' argument to the ‘Stats’ constructor. (Contributed by Skip Montanaro.) * The *note csv: 2a. module, which parses files in comma-separated value format, received several enhancements and a number of bugfixes. You can now set the maximum size in bytes of a field by calling the ‘csv.field_size_limit(new_limit)’ function; omitting the `new_limit' argument will return the currently-set limit. The ‘reader’ class now has a ‘line_num’ attribute that counts the number of physical lines read from the source; records can span multiple physical lines, so ‘line_num’ is not the same as the number of records read. The CSV parser is now stricter about multi-line quoted fields. Previously, if a line ended within a quoted field without a terminating newline character, a newline would be inserted into the returned field. This behavior caused problems when reading files that contained carriage return characters within fields, so the code was changed to return the field without inserting newlines. As a consequence, if newlines embedded within fields are important, the input should be split into lines in a manner that preserves the newline characters. (Contributed by Skip Montanaro and Andrew McNamara.) * The *note datetime: 194. class in the *note datetime: 31. module now has a ‘strptime(string, format)’ method for parsing date strings, contributed by Josh Spoerri. It uses the same format characters as *note time.strptime(): d91. and *note time.strftime(): b65.: from datetime import datetime ts = datetime.strptime('10:13:15 2006-03-07', '%H:%M:%S %Y-%m-%d') * The ‘SequenceMatcher.get_matching_blocks()’ method in the *note difflib: 37. module now guarantees to return a minimal list of blocks describing matching subsequences. Previously, the algorithm would occasionally break a block of matching elements into two list entries. (Enhancement by Tim Peters.) * The *note doctest: 67. module gained a ‘SKIP’ option that keeps an example from being executed at all. This is intended for code snippets that are usage examples intended for the reader and aren’t actually test cases. An `encoding' parameter was added to the ‘testfile()’ function and the ‘DocFileSuite’ class to specify the file’s encoding. This makes it easier to use non-ASCII characters in tests contained within a docstring. (Contributed by Bjorn Tillenius.) * The *note email: 69. package has been updated to version 4.0. (Contributed by Barry Warsaw.) * The *note fileinput: 80. module was made more flexible. Unicode filenames are now supported, and a `mode' parameter that defaults to ‘"r"’ was added to the *note input(): c6b. function to allow opening files in binary or *note universal newlines: 5f4. mode. Another new parameter, `openhook', lets you use a function other than *note open(): 4f0. to open the input files. Once you’re iterating over the set of files, the ‘FileInput’ object’s new ‘fileno()’ returns the file descriptor for the currently opened file. (Contributed by Georg Brandl.) * In the *note gc: 86. module, the new ‘get_count()’ function returns a 3-tuple containing the current collection counts for the three GC generations. This is accounting information for the garbage collector; when these counts reach a specified threshold, a garbage collection sweep will be made. The existing *note gc.collect(): 22e. function now takes an optional `generation' argument of 0, 1, or 2 to specify which generation to collect. (Contributed by Barry Warsaw.) * The ‘nsmallest()’ and ‘nlargest()’ functions in the *note heapq: 8e. module now support a ‘key’ keyword parameter similar to the one provided by the *note min(): 809./*note max(): 80a. functions and the ‘sort()’ methods. For example: >>> import heapq >>> L = ["short", 'medium', 'longest', 'longer still'] >>> heapq.nsmallest(2, L) # Return two lowest elements, lexicographically ['longer still', 'longest'] >>> heapq.nsmallest(2, L, key=len) # Return two shortest elements ['short', 'medium'] (Contributed by Raymond Hettinger.) * The *note itertools.islice(): 3a2. function now accepts ‘None’ for the start and step arguments. This makes it more compatible with the attributes of slice objects, so that you can now write the following: s = slice(5) # Create slice object itertools.islice(iterable, s.start, s.stop, s.step) (Contributed by Raymond Hettinger.) * The *note format(): 4db. function in the *note locale: a9. module has been modified and two new functions were added, ‘format_string()’ and ‘currency()’. The *note format(): 4db. function’s `val' parameter could previously be a string as long as no more than one %char specifier appeared; now the parameter must be exactly one %char specifier with no surrounding text. An optional `monetary' parameter was also added which, if ‘True’, will use the locale’s rules for formatting currency in placing a separator between groups of three digits. To format strings with multiple %char specifiers, use the new ‘format_string()’ function that works like *note format(): 4db. but also supports mixing %char specifiers with arbitrary text. A new ‘currency()’ function was also added that formats a number according to the current locale’s settings. (Contributed by Georg Brandl.) * The *note mailbox: ae. module underwent a massive rewrite to add the capability to modify mailboxes in addition to reading them. A new set of classes that include ‘mbox’, ‘MH’, and ‘Maildir’ are used to read mailboxes, and have an ‘add(message)’ method to add messages, ‘remove(key)’ to remove messages, and ‘lock()’/‘unlock()’ to lock/unlock the mailbox. The following example converts a maildir-format mailbox into an mbox-format one: import mailbox # 'factory=None' uses email.Message.Message as the class representing # individual messages. src = mailbox.Maildir('maildir', factory=None) dest = mailbox.mbox('/tmp/mbox') for msg in src: dest.add(msg) (Contributed by Gregory K. Johnson. Funding was provided by Google’s 2005 Summer of Code.) * New module: the *note msilib: b5. module allows creating Microsoft Installer ‘.msi’ files and CAB files. Some support for reading the ‘.msi’ database is also included. (Contributed by Martin von Löwis.) * The *note nis: bf. module now supports accessing domains other than the system default domain by supplying a `domain' argument to the *note nis.match(): d92. and *note nis.maps(): d93. functions. (Contributed by Ben Bell.) * The *note operator: c2. module’s ‘itemgetter()’ and ‘attrgetter()’ functions now support multiple fields. A call such as ‘operator.attrgetter('a', 'b')’ will return a function that retrieves the ‘a’ and ‘b’ attributes. Combining this new feature with the ‘sort()’ method’s ‘key’ parameter lets you easily sort lists using multiple fields. (Contributed by Raymond Hettinger.) * The *note optparse: c3. module was updated to version 1.5.1 of the Optik library. The ‘OptionParser’ class gained an ‘epilog’ attribute, a string that will be printed after the help message, and a ‘destroy()’ method to break reference cycles created by the object. (Contributed by Greg Ward.) * The *note os: c4. module underwent several changes. The ‘stat_float_times’ variable now defaults to true, meaning that *note os.stat(): 1f1. will now return time values as floats. (This doesn’t necessarily mean that *note os.stat(): 1f1. will return times that are precise to fractions of a second; not all systems support such precision.) Constants named *note os.SEEK_SET: d94, *note os.SEEK_CUR: d95, and *note os.SEEK_END: d96. have been added; these are the parameters to the *note os.lseek(): a5e. function. Two new constants for locking are *note os.O_SHLOCK: d97. and *note os.O_EXLOCK: d98. Two new functions, ‘wait3()’ and ‘wait4()’, were added. They’re similar the ‘waitpid()’ function which waits for a child process to exit and returns a tuple of the process ID and its exit status, but ‘wait3()’ and ‘wait4()’ return additional information. ‘wait3()’ doesn’t take a process ID as input, so it waits for any child process to exit and returns a 3-tuple of `process-id', `exit-status', `resource-usage' as returned from the *note resource.getrusage(): d99. function. ‘wait4(pid)’ does take a process ID. (Contributed by Chad J. Schroeder.) On FreeBSD, the *note os.stat(): 1f1. function now returns times with nanosecond resolution, and the returned object now has ‘st_gen’ and ‘st_birthtime’. The ‘st_flags’ attribute is also available, if the platform supports it. (Contributed by Antti Louko and Diego Pettenò.) * The Python debugger provided by the *note pdb: c9. module can now store lists of commands to execute when a breakpoint is reached and execution stops. Once breakpoint #1 has been created, enter ‘commands 1’ and enter a series of commands to be executed, finishing the list with ‘end’. The command list can include commands that resume execution, such as ‘continue’ or ‘next’. (Contributed by Grégoire Dooms.) * The *note pickle: ca. and ‘cPickle’ modules no longer accept a return value of ‘None’ from the *note __reduce__(): 19b. method; the method must return a tuple of arguments instead. The ability to return ‘None’ was deprecated in Python 2.4, so this completes the removal of the feature. * The *note pkgutil: cd. module, containing various utility functions for finding packages, was enhanced to support PEP 302(1)’s import hooks and now also works for packages stored in ZIP-format archives. (Contributed by Phillip J. Eby.) * The pybench benchmark suite by Marc-André Lemburg is now included in the ‘Tools/pybench’ directory. The pybench suite is an improvement on the commonly used ‘pystone.py’ program because pybench provides a more detailed measurement of the interpreter’s speed. It times particular operations such as function calls, tuple slicing, method lookups, and numeric operations, instead of performing many different operations and reducing the result to a single number as ‘pystone.py’ does. * The ‘pyexpat’ module now uses version 2.0 of the Expat parser. (Contributed by Trent Mick.) * The *note Queue: d18. class provided by the ‘Queue’ module gained two new methods. ‘join()’ blocks until all items in the queue have been retrieved and all processing work on the items have been completed. Worker threads call the other new method, ‘task_done()’, to signal that processing for an item has been completed. (Contributed by Raymond Hettinger.) * The old ‘regex’ and ‘regsub’ modules, which have been deprecated ever since Python 2.0, have finally been deleted. Other deleted modules: ‘statcache’, ‘tzparse’, ‘whrandom’. * Also deleted: the ‘lib-old’ directory, which includes ancient modules such as ‘dircmp’ and ‘ni’, was removed. ‘lib-old’ wasn’t on the default ‘sys.path’, so unless your programs explicitly added the directory to ‘sys.path’, this removal shouldn’t affect your code. * The *note rlcompleter: e1. module is no longer dependent on importing the *note readline: de. module and therefore now works on non-Unix platforms. (Patch from Robert Kiendl.) * The ‘SimpleXMLRPCServer’ and ‘DocXMLRPCServer’ classes now have a ‘rpc_paths’ attribute that constrains XML-RPC operations to a limited set of URL paths; the default is to allow only ‘'/'’ and ‘'/RPC2'’. Setting ‘rpc_paths’ to ‘None’ or an empty tuple disables this path checking. * The *note socket: ef. module now supports ‘AF_NETLINK’ sockets on Linux, thanks to a patch from Philippe Biondi. Netlink sockets are a Linux-specific mechanism for communications between a user-space process and kernel code; an introductory article about them is at ‘https://www.linuxjournal.com/article/7356’. In Python code, netlink addresses are represented as a tuple of 2 integers, ‘(pid, group_mask)’. Two new methods on socket objects, ‘recv_into(buffer)’ and ‘recvfrom_into(buffer)’, store the received data in an object that supports the buffer protocol instead of returning the data as a string. This means you can put the data directly into an array or a memory-mapped file. Socket objects also gained ‘getfamily()’, ‘gettype()’, and ‘getproto()’ accessor methods to retrieve the family, type, and protocol values for the socket. * New module: the *note spwd: f1. module provides functions for accessing the shadow password database on systems that support shadow passwords. * The *note struct: f8. is now faster because it compiles format strings into ‘Struct’ objects with ‘pack()’ and ‘unpack()’ methods. This is similar to how the *note re: dd. module lets you create compiled regular expression objects. You can still use the module-level ‘pack()’ and ‘unpack()’ functions; they’ll create ‘Struct’ objects and cache them. Or you can use ‘Struct’ instances directly: s = struct.Struct('ih3s') data = s.pack(1972, 187, 'abc') year, number, name = s.unpack(data) You can also pack and unpack data to and from buffer objects directly using the ‘pack_into(buffer, offset, v1, v2, ...)’ and ‘unpack_from(buffer, offset)’ methods. This lets you store data directly into an array or a memory-mapped file. (‘Struct’ objects were implemented by Bob Ippolito at the NeedForSpeed sprint. Support for buffer objects was added by Martin Blais, also at the NeedForSpeed sprint.) * The Python developers switched from CVS to Subversion during the 2.5 development process. Information about the exact build version is available as the ‘sys.subversion’ variable, a 3-tuple of ‘(interpreter-name, branch-name, revision-range)’. For example, at the time of writing my copy of 2.5 was reporting ‘('CPython', 'trunk', '45313:45315')’. This information is also available to C extensions via the *note Py_GetBuildInfo(): d9a. function that returns a string of build information like this: ‘"trunk:45355:45356M, Apr 13 2006, 07:42:19"’. (Contributed by Barry Warsaw.) * Another new function, *note sys._current_frames(): d9b, returns the current stack frames for all running threads as a dictionary mapping thread identifiers to the topmost stack frame currently active in that thread at the time the function is called. (Contributed by Tim Peters.) * The ‘TarFile’ class in the *note tarfile: 101. module now has an ‘extractall()’ method that extracts all members from the archive into the current working directory. It’s also possible to set a different directory as the extraction target, and to unpack only a subset of the archive’s members. The compression used for a tarfile opened in stream mode can now be autodetected using the mode ‘'r|*'’. (Contributed by Lars Gustäbel.) * The *note threading: 109. module now lets you set the stack size used when new threads are created. The ‘stack_size([*size*])’ function returns the currently configured stack size, and supplying the optional `size' parameter sets a new value. Not all platforms support changing the stack size, but Windows, POSIX threading, and OS/2 all do. (Contributed by Andrew MacIntyre.) * The *note unicodedata: 11a. module has been updated to use version 4.1.0 of the Unicode character database. Version 3.2.0 is required by some specifications, so it’s still available as *note unicodedata.ucd_3_2_0: d9c. * New module: the *note uuid: 124. module generates universally unique identifiers (UUIDs) according to RFC 4122(2). The RFC defines several different UUID versions that are generated from a starting string, from system properties, or purely randomly. This module contains a ‘UUID’ class and functions named ‘uuid1()’, ‘uuid3()’, ‘uuid4()’, and ‘uuid5()’ to generate different versions of UUID. (Version 2 UUIDs are not specified in RFC 4122(3) and are not supported by this module.) >>> import uuid >>> # make a UUID based on the host ID and current time >>> uuid.uuid1() UUID('a8098c1a-f86e-11da-bd1a-00112444be1e') >>> # make a UUID using an MD5 hash of a namespace UUID and a name >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org') UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e') >>> # make a random UUID >>> uuid.uuid4() UUID('16fd2706-8baf-433b-82eb-8c7fada847da') >>> # make a UUID using a SHA-1 hash of a namespace UUID and a name >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org') UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d') (Contributed by Ka-Ping Yee.) * The *note weakref: 128. module’s ‘WeakKeyDictionary’ and ‘WeakValueDictionary’ types gained new methods for iterating over the weak references contained in the dictionary. ‘iterkeyrefs()’ and ‘keyrefs()’ methods were added to ‘WeakKeyDictionary’, and ‘itervaluerefs()’ and ‘valuerefs()’ were added to ‘WeakValueDictionary’. (Contributed by Fred L. Drake, Jr.) * The *note webbrowser: 129. module received a number of enhancements. It’s now usable as a script with ‘python -m webbrowser’, taking a URL as the argument; there are a number of switches to control the behaviour (‘-n’ for a new browser window, ‘-t’ for a new tab). New module-level functions, ‘open_new()’ and ‘open_new_tab()’, were added to support this. The module’s *note open(): 4f0. function supports an additional feature, an `autoraise' parameter that signals whether to raise the open window when possible. A number of additional browsers were added to the supported list such as Firefox, Opera, Konqueror, and elinks. (Contributed by Oleg Broytmann and Georg Brandl.) * The ‘xmlrpclib’ module now supports returning *note datetime: 194. objects for the XML-RPC date type. Supply ‘use_datetime=True’ to the ‘loads()’ function or the ‘Unmarshaller’ class to enable this feature. (Contributed by Skip Montanaro.) * The *note zipfile: 142. module now supports the ZIP64 version of the format, meaning that a .zip archive can now be larger than 4 GiB and can contain individual files larger than 4 GiB. (Contributed by Ronald Oussoren.) * The *note zlib: 144. module’s ‘Compress’ and ‘Decompress’ objects now support a *note copy(): 26. method that makes a copy of the object’s internal state and returns a new ‘Compress’ or ‘Decompress’ object. (Contributed by Chris AtLee.) * Menu: * The ctypes package:: * The ElementTree package:: * The hashlib package:: * The sqlite3 package:: * The wsgiref package:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0302 (2) https://tools.ietf.org/html/rfc4122.html (3) https://tools.ietf.org/html/rfc4122.html  File: python.info, Node: The ctypes package, Next: The ElementTree package, Up: New Improved and Removed Modules 1.12.13.1 The ctypes package ............................ The *note ctypes: 2b. package, written by Thomas Heller, has been added to the standard library. *note ctypes: 2b. lets you call arbitrary functions in shared libraries or DLLs. Long-time users may remember the ‘dl’ module, which provides functions for loading shared libraries and calling functions in them. The *note ctypes: 2b. package is much fancier. To load a shared library or DLL, you must create an instance of the ‘CDLL’ class and provide the name or path of the shared library or DLL. Once that’s done, you can call arbitrary functions by accessing them as attributes of the ‘CDLL’ object. import ctypes libc = ctypes.CDLL('libc.so.6') result = libc.printf("Line of output\n") Type constructors for the various C types are provided: ‘c_int()’, ‘c_float()’, ‘c_double()’, ‘c_char_p()’ (equivalent to ‘char *’), and so forth. Unlike Python’s types, the C versions are all mutable; you can assign to their ‘value’ attribute to change the wrapped value. Python integers and strings will be automatically converted to the corresponding C types, but for other types you must call the correct type constructor. (And I mean `must'; getting it wrong will often result in the interpreter crashing with a segmentation fault.) You shouldn’t use ‘c_char_p()’ with a Python string when the C function will be modifying the memory area, because Python strings are supposed to be immutable; breaking this rule will cause puzzling bugs. When you need a modifiable memory area, use ‘create_string_buffer()’: s = "this is a string" buf = ctypes.create_string_buffer(s) libc.strfry(buf) C functions are assumed to return integers, but you can set the ‘restype’ attribute of the function object to change this: >>> libc.atof('2.71828') -1783957616 >>> libc.atof.restype = ctypes.c_double >>> libc.atof('2.71828') 2.71828 *note ctypes: 2b. also provides a wrapper for Python’s C API as the ‘ctypes.pythonapi’ object. This object does `not' release the global interpreter lock before calling a function, because the lock must be held when calling into the interpreter’s code. There’s a ‘py_object()’ type constructor that will create a *note PyObject *: 4ba. pointer. A simple usage: import ctypes d = {} ctypes.pythonapi.PyObject_SetItem(ctypes.py_object(d), ctypes.py_object("abc"), ctypes.py_object(1)) # d is now {'abc', 1}. Don’t forget to use ‘py_object()’; if it’s omitted you end up with a segmentation fault. *note ctypes: 2b. has been around for a while, but people still write and distribution hand-coded extension modules because you can’t rely on *note ctypes: 2b. being present. Perhaps developers will begin to write Python wrappers atop a library accessed through *note ctypes: 2b. instead of extension modules, now that *note ctypes: 2b. is included with core Python. See also ........ ‘http://starship.python.net/crew/theller/ctypes/’ The ctypes web page, with a tutorial, reference, and FAQ. The documentation for the *note ctypes: 2b. module.  File: python.info, Node: The ElementTree package, Next: The hashlib package, Prev: The ctypes package, Up: New Improved and Removed Modules 1.12.13.2 The ElementTree package ................................. A subset of Fredrik Lundh’s ElementTree library for processing XML has been added to the standard library as ‘xml.etree’. The available modules are ‘ElementTree’, ‘ElementPath’, and ‘ElementInclude’ from ElementTree 1.2.6. The ‘cElementTree’ accelerator module is also included. The rest of this section will provide a brief overview of using ElementTree. Full documentation for ElementTree is available at ‘http://effbot.org/zone/element-index.htm’. ElementTree represents an XML document as a tree of element nodes. The text content of the document is stored as the ‘text’ and ‘tail’ attributes of (This is one of the major differences between ElementTree and the Document Object Model; in the DOM there are many different types of node, including ‘TextNode’.) The most commonly used parsing function is ‘parse()’, that takes either a string (assumed to contain a filename) or a file-like object and returns an ‘ElementTree’ instance: from xml.etree import ElementTree as ET tree = ET.parse('ex-1.xml') feed = urllib.urlopen( 'http://planet.python.org/rss10.xml') tree = ET.parse(feed) Once you have an ‘ElementTree’ instance, you can call its ‘getroot()’ method to get the root ‘Element’ node. There’s also an ‘XML()’ function that takes a string literal and returns an ‘Element’ node (not an ‘ElementTree’). This function provides a tidy way to incorporate XML fragments, approaching the convenience of an XML literal: svg = ET.XML(""" """) svg.set('height', '320px') svg.append(elem1) Each XML element supports some dictionary-like and some list-like access methods. Dictionary-like operations are used to access attribute values, and list-like operations are used to access child nodes. Operation Result ------------------------------------------------------------------------------------- ‘elem[n]’ Returns n’th child element. ‘elem[m:n]’ Returns list of m’th through n’th child elements. ‘len(elem)’ Returns number of child elements. ‘list(elem)’ Returns list of child elements. ‘elem.append(elem2)’ Adds `elem2' as a child. ‘elem.insert(index, elem2)’ Inserts `elem2' at the specified location. ‘del elem[n]’ Deletes n’th child element. ‘elem.keys()’ Returns list of attribute names. ‘elem.get(name)’ Returns value of attribute `name'. ‘elem.set(name, value)’ Sets new value for attribute `name'. ‘elem.attrib’ Retrieves the dictionary containing attributes. ‘del elem.attrib[name]’ Deletes attribute `name'. Comments and processing instructions are also represented as ‘Element’ nodes. To check if a node is a comment or processing instructions: if elem.tag is ET.Comment: ... elif elem.tag is ET.ProcessingInstruction: ... To generate XML output, you should call the ‘ElementTree.write()’ method. Like ‘parse()’, it can take either a string or a file-like object: # Encoding is US-ASCII tree.write('output.xml') # Encoding is UTF-8 f = open('output.xml', 'w') tree.write(f, encoding='utf-8') (Caution: the default encoding used for output is ASCII. For general XML work, where an element’s name may contain arbitrary Unicode characters, ASCII isn’t a very useful encoding because it will raise an exception if an element’s name contains any characters with values greater than 127. Therefore, it’s best to specify a different encoding such as UTF-8 that can handle any Unicode character.) This section is only a partial description of the ElementTree interfaces. Please read the package’s official documentation for more details. See also ........ ‘http://effbot.org/zone/element-index.htm’ Official documentation for ElementTree.  File: python.info, Node: The hashlib package, Next: The sqlite3 package, Prev: The ElementTree package, Up: New Improved and Removed Modules 1.12.13.3 The hashlib package ............................. A new *note hashlib: 8d. module, written by Gregory P. Smith, has been added to replace the ‘md5’ and ‘sha’ modules. *note hashlib: 8d. adds support for additional secure hashes (SHA-224, SHA-256, SHA-384, and SHA-512). When available, the module uses OpenSSL for fast platform optimized implementations of algorithms. The old ‘md5’ and ‘sha’ modules still exist as wrappers around hashlib to preserve backwards compatibility. The new module’s interface is very close to that of the old modules, but not identical. The most significant difference is that the constructor functions for creating new hashing objects are named differently. # Old versions h = md5.md5() h = md5.new() # New version h = hashlib.md5() # Old versions h = sha.sha() h = sha.new() # New version h = hashlib.sha1() # Hash that weren't previously available h = hashlib.sha224() h = hashlib.sha256() h = hashlib.sha384() h = hashlib.sha512() # Alternative form h = hashlib.new('md5') # Provide algorithm as a string Once a hash object has been created, its methods are the same as before: ‘update(string)’ hashes the specified string into the current digest state, ‘digest()’ and ‘hexdigest()’ return the digest value as a binary string or a string of hex digits, and *note copy(): 26. returns a new hashing object with the same digest state. See also ........ The documentation for the *note hashlib: 8d. module.  File: python.info, Node: The sqlite3 package, Next: The wsgiref package, Prev: The hashlib package, Up: New Improved and Removed Modules 1.12.13.4 The sqlite3 package ............................. The pysqlite module (‘http://www.pysqlite.org’), a wrapper for the SQLite embedded database, has been added to the standard library under the package name *note sqlite3: f2. SQLite is a C library that provides a lightweight disk-based database that doesn’t require a separate server process and allows accessing the database using a nonstandard variant of the SQL query language. Some applications can use SQLite for internal data storage. It’s also possible to prototype an application using SQLite and then port the code to a larger database such as PostgreSQL or Oracle. pysqlite was written by Gerhard Häring and provides a SQL interface compliant with the DB-API 2.0 specification described by PEP 249(1). If you’re compiling the Python source yourself, note that the source tree doesn’t include the SQLite code, only the wrapper module. You’ll need to have the SQLite libraries and headers installed before compiling Python, and the build process will compile the module when the necessary headers are available. To use the module, you must first create a ‘Connection’ object that represents the database. Here the data will be stored in the ‘/tmp/example’ file: conn = sqlite3.connect('/tmp/example') You can also supply the special name ‘:memory:’ to create a database in RAM. Once you have a ‘Connection’, you can create a ‘Cursor’ object and call its ‘execute()’ method to perform SQL commands: c = conn.cursor() # Create table c.execute('''create table stocks (date text, trans text, symbol text, qty real, price real)''') # Insert a row of data c.execute("""insert into stocks values ('2006-01-05','BUY','RHAT',100,35.14)""") Usually your SQL operations will need to use values from Python variables. You shouldn’t assemble your query using Python’s string operations because doing so is insecure; it makes your program vulnerable to an SQL injection attack. Instead, use the DB-API’s parameter substitution. Put ‘?’ as a placeholder wherever you want to use a value, and then provide a tuple of values as the second argument to the cursor’s ‘execute()’ method. (Other database modules may use a different placeholder, such as ‘%s’ or ‘:1’.) For example: # Never do this -- insecure! symbol = 'IBM' c.execute("... where symbol = '%s'" % symbol) # Do this instead t = (symbol,) c.execute('select * from stocks where symbol=?', t) # Larger example for t in (('2006-03-28', 'BUY', 'IBM', 1000, 45.00), ('2006-04-05', 'BUY', 'MSOFT', 1000, 72.00), ('2006-04-06', 'SELL', 'IBM', 500, 53.00), ): c.execute('insert into stocks values (?,?,?,?,?)', t) To retrieve data after executing a SELECT statement, you can either treat the cursor as an iterator, call the cursor’s ‘fetchone()’ method to retrieve a single matching row, or call ‘fetchall()’ to get a list of the matching rows. This example uses the iterator form: >>> c = conn.cursor() >>> c.execute('select * from stocks order by price') >>> for row in c: ... print row ... (u'2006-01-05', u'BUY', u'RHAT', 100, 35.140000000000001) (u'2006-03-28', u'BUY', u'IBM', 1000, 45.0) (u'2006-04-06', u'SELL', u'IBM', 500, 53.0) (u'2006-04-05', u'BUY', u'MSOFT', 1000, 72.0) >>> For more information about the SQL dialect supported by SQLite, see ‘https://www.sqlite.org’. See also ........ ‘http://www.pysqlite.org’ The pysqlite web page. ‘https://www.sqlite.org’ The SQLite web page; the documentation describes the syntax and the available data types for the supported SQL dialect. The documentation for the *note sqlite3: f2. module. PEP 249(2) - Database API Specification 2.0 PEP written by Marc-André Lemburg. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0249 (2) https://www.python.org/dev/peps/pep-0249  File: python.info, Node: The wsgiref package, Prev: The sqlite3 package, Up: New Improved and Removed Modules 1.12.13.5 The wsgiref package ............................. The Web Server Gateway Interface (WSGI) v1.0 defines a standard interface between web servers and Python web applications and is described in PEP 333(1). The *note wsgiref: 12c. package is a reference implementation of the WSGI specification. The package includes a basic HTTP server that will run a WSGI application; this server is useful for debugging but isn’t intended for production use. Setting up a server takes only a few lines of code: from wsgiref import simple_server wsgi_app = ... host = '' port = 8000 httpd = simple_server.make_server(host, port, wsgi_app) httpd.serve_forever() See also ........ ‘http://www.wsgi.org’ A central web site for WSGI-related resources. PEP 333(2) - Python Web Server Gateway Interface v1.0 PEP written by Phillip J. Eby. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0333 (2) https://www.python.org/dev/peps/pep-0333  File: python.info, Node: Build and C API Changes<10>, Next: Porting to Python 2 5, Prev: New Improved and Removed Modules, Up: What’s New in Python 2 5 1.12.14 Build and C API Changes ------------------------------- Changes to Python’s build process and to the C API include: * The Python source tree was converted from CVS to Subversion, in a complex migration procedure that was supervised and flawlessly carried out by Martin von Löwis. The procedure was developed as PEP 347(1). * Coverity, a company that markets a source code analysis tool called Prevent, provided the results of their examination of the Python source code. The analysis found about 60 bugs that were quickly fixed. Many of the bugs were refcounting problems, often occurring in error-handling code. See ‘https://scan.coverity.com’ for the statistics. * The largest change to the C API came from PEP 353(2), which modifies the interpreter to use a ‘Py_ssize_t’ type definition instead of ‘int’. See the earlier section *note PEP 353; Using ssize_t as the index type: d7c. for a discussion of this change. * The design of the bytecode compiler has changed a great deal, no longer generating bytecode by traversing the parse tree. Instead the parse tree is converted to an abstract syntax tree (or AST), and it is the abstract syntax tree that’s traversed to produce the bytecode. It’s possible for Python code to obtain AST objects by using the *note compile(): 1b4. built-in and specifying ‘_ast.PyCF_ONLY_AST’ as the value of the `flags' parameter: from _ast import PyCF_ONLY_AST ast = compile("""a=0 for i in range(10): a += i """, "", 'exec', PyCF_ONLY_AST) assignment = ast.body[0] for_loop = ast.body[1] No official documentation has been written for the AST code yet, but PEP 339(3) discusses the design. To start learning about the code, read the definition of the various AST nodes in ‘Parser/Python.asdl’. A Python script reads this file and generates a set of C structure definitions in ‘Include/Python-ast.h’. The ‘PyParser_ASTFromString()’ and ‘PyParser_ASTFromFile()’, defined in ‘Include/pythonrun.h’, take Python source as input and return the root of an AST representing the contents. This AST can then be turned into a code object by ‘PyAST_Compile()’. For more information, read the source code, and then ask questions on python-dev. The AST code was developed under Jeremy Hylton’s management, and implemented by (in alphabetical order) Brett Cannon, Nick Coghlan, Grant Edwards, John Ehresman, Kurt Kaiser, Neal Norwitz, Tim Peters, Armin Rigo, and Neil Schemenauer, plus the participants in a number of AST sprints at conferences such as PyCon. * Evan Jones’s patch to obmalloc, first described in a talk at PyCon DC 2005, was applied. Python 2.4 allocated small objects in 256K-sized arenas, but never freed arenas. With this patch, Python will free arenas when they’re empty. The net effect is that on some platforms, when you allocate many objects, Python’s memory usage may actually drop when you delete them and the memory may be returned to the operating system. (Implemented by Evan Jones, and reworked by Tim Peters.) Note that this change means extension modules must be more careful when allocating memory. Python’s API has many different functions for allocating memory that are grouped into families. For example, *note PyMem_Malloc(): 505, *note PyMem_Realloc(): 96f, and *note PyMem_Free(): da9. are one family that allocates raw memory, while *note PyObject_Malloc(): 508, *note PyObject_Realloc(): daa, and *note PyObject_Free(): 504. are another family that’s supposed to be used for creating Python objects. Previously these different families all reduced to the platform’s ‘malloc()’ and ‘free()’ functions. This meant it didn’t matter if you got things wrong and allocated memory with the ‘PyMem()’ function but freed it with the *note PyObject(): 4ba. function. With 2.5’s changes to obmalloc, these families now do different things and mismatches will probably result in a segfault. You should carefully test your C extension modules with Python 2.5. * The built-in set types now have an official C API. Call *note PySet_New(): dab. and *note PyFrozenSet_New(): dac. to create a new set, *note PySet_Add(): dad. and *note PySet_Discard(): dae. to add and remove elements, and *note PySet_Contains(): daf. and *note PySet_Size(): db0. to examine the set’s state. (Contributed by Raymond Hettinger.) * C code can now obtain information about the exact revision of the Python interpreter by calling the *note Py_GetBuildInfo(): d9a. function that returns a string of build information like this: ‘"trunk:45355:45356M, Apr 13 2006, 07:42:19"’. (Contributed by Barry Warsaw.) * Two new macros can be used to indicate C functions that are local to the current file so that a faster calling convention can be used. ‘Py_LOCAL(type)’ declares the function as returning a value of the specified `type' and uses a fast-calling qualifier. ‘Py_LOCAL_INLINE(type)’ does the same thing and also requests the function be inlined. If ‘PY_LOCAL_AGGRESSIVE()’ is defined before ‘python.h’ is included, a set of more aggressive optimizations are enabled for the module; you should benchmark the results to find out if these optimizations actually make the code faster. (Contributed by Fredrik Lundh at the NeedForSpeed sprint.) * ‘PyErr_NewException(name, base, dict)’ can now accept a tuple of base classes as its `base' argument. (Contributed by Georg Brandl.) * The ‘PyErr_Warn()’ function for issuing warnings is now deprecated in favour of ‘PyErr_WarnEx(category, message, stacklevel)’ which lets you specify the number of stack frames separating this function and the caller. A `stacklevel' of 1 is the function calling *note PyErr_WarnEx(): db1, 2 is the function above that, and so forth. (Added by Neal Norwitz.) * The CPython interpreter is still written in C, but the code can now be compiled with a C++ compiler without errors. (Implemented by Anthony Baxter, Martin von Löwis, Skip Montanaro.) * The ‘PyRange_New()’ function was removed. It was never documented, never used in the core code, and had dangerously lax error checking. In the unlikely case that your extensions were using it, you can replace it by something like the following: range = PyObject_CallFunction((PyObject*) &PyRange_Type, "lll", start, stop, step); * Menu: * Port-Specific Changes:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0347 (2) https://www.python.org/dev/peps/pep-0353 (3) https://www.python.org/dev/peps/pep-0339  File: python.info, Node: Port-Specific Changes, Up: Build and C API Changes<10> 1.12.14.1 Port-Specific Changes ............................... * MacOS X (10.3 and higher): dynamic loading of modules now uses the ‘dlopen()’ function instead of MacOS-specific functions. * MacOS X: an ‘--enable-universalsdk’ switch was added to the ‘configure’ script that compiles the interpreter as a universal binary able to run on both PowerPC and Intel processors. (Contributed by Ronald Oussoren; bpo-2573(1).) * Windows: ‘.dll’ is no longer supported as a filename extension for extension modules. ‘.pyd’ is now the only filename extension that will be searched for. ---------- Footnotes ---------- (1) https://bugs.python.org/issue2573  File: python.info, Node: Porting to Python 2 5, Next: Acknowledgements<3>, Prev: Build and C API Changes<10>, Up: What’s New in Python 2 5 1.12.15 Porting to Python 2.5 ----------------------------- This section lists previously described changes that may require changes to your code: * ASCII is now the default encoding for modules. It’s now a syntax error if a module contains string literals with 8-bit characters but doesn’t have an encoding declaration. In Python 2.4 this triggered a warning, not a syntax error. * Previously, the ‘gi_frame’ attribute of a generator was always a frame object. Because of the PEP 342(1) changes described in section *note PEP 342; New Generator Features: d66, it’s now possible for ‘gi_frame’ to be ‘None’. * A new warning, *note UnicodeWarning: d87, is triggered when you attempt to compare a Unicode string and an 8-bit string that can’t be converted to Unicode using the default ASCII encoding. Previously such comparisons would raise a *note UnicodeDecodeError: 1fd. exception. * Library: the *note csv: 2a. module is now stricter about multi-line quoted fields. If your files contain newlines embedded within fields, the input should be split into lines in a manner which preserves the newline characters. * Library: the *note locale: a9. module’s *note format(): 4db. function’s would previously accept any string as long as no more than one %char specifier appeared. In Python 2.5, the argument must be exactly one %char specifier with no surrounding text. * Library: The *note pickle: ca. and ‘cPickle’ modules no longer accept a return value of ‘None’ from the *note __reduce__(): 19b. method; the method must return a tuple of arguments instead. The modules also no longer accept the deprecated `bin' keyword parameter. * Library: The ‘SimpleXMLRPCServer’ and ‘DocXMLRPCServer’ classes now have a ‘rpc_paths’ attribute that constrains XML-RPC operations to a limited set of URL paths; the default is to allow only ‘'/'’ and ‘'/RPC2'’. Setting ‘rpc_paths’ to ‘None’ or an empty tuple disables this path checking. * C API: Many functions now use ‘Py_ssize_t’ instead of ‘int’ to allow processing more data on 64-bit machines. Extension code may need to make the same change to avoid warnings and to support 64-bit machines. See the earlier section *note PEP 353; Using ssize_t as the index type: d7c. for a discussion of this change. * C API: The obmalloc changes mean that you must be careful to not mix usage of the ‘PyMem_*()’ and ‘PyObject_*()’ families of functions. Memory allocated with one family’s ‘*_Malloc()’ must be freed with the corresponding family’s ‘*_Free()’ function. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0342  File: python.info, Node: Acknowledgements<3>, Prev: Porting to Python 2 5, Up: What’s New in Python 2 5 1.12.16 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Georg Brandl, Nick Coghlan, Phillip J. Eby, Lars Gustäbel, Raymond Hettinger, Ralf W. Grosse-Kunstleve, Kent Johnson, Iain Lowe, Martin von Löwis, Fredrik Lundh, Andrew McNamara, Skip Montanaro, Gustavo Niemeyer, Paul Prescod, James Pryor, Mike Rovner, Scott Weikart, Barry Warsaw, Thomas Wouters.  File: python.info, Node: What’s New in Python 2 4, Next: What’s New in Python 2 3, Prev: What’s New in Python 2 5, Up: What’s New in Python 1.13 What’s New in Python 2.4 ============================= Author: A.M. Kuchling This article explains the new features in Python 2.4.1, released on March 30, 2005. Python 2.4 is a medium-sized release. It doesn’t introduce as many changes as the radical Python 2.2, but introduces more features than the conservative 2.3 release. The most significant new language features are function decorators and generator expressions; most other changes are to the standard library. According to the CVS change logs, there were 481 patches applied and 502 bugs fixed between Python 2.3 and 2.4. Both figures are likely to be underestimates. This article doesn’t attempt to provide a complete specification of every single new feature, but instead provides a brief introduction to each feature. For full details, you should refer to the documentation for Python 2.4, such as the Python Library Reference and the Python Reference Manual. Often you will be referred to the PEP for a particular new feature for explanations of the implementation and design rationale. * Menu: * PEP 218; Built-In Set Objects: PEP 218 Built-In Set Objects. * PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers. * PEP 289; Generator Expressions: PEP 289 Generator Expressions. * PEP 292; Simpler String Substitutions: PEP 292 Simpler String Substitutions. * PEP 318; Decorators for Functions and Methods: PEP 318 Decorators for Functions and Methods. * PEP 322; Reverse Iteration: PEP 322 Reverse Iteration. * PEP 324; New subprocess Module: PEP 324 New subprocess Module. * PEP 327; Decimal Data Type: PEP 327 Decimal Data Type. * PEP 328; Multi-line Imports: PEP 328 Multi-line Imports. * PEP 331; Locale-Independent Float/String Conversions: PEP 331 Locale-Independent Float/String Conversions. * Other Language Changes: Other Language Changes<12>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<3>. * Build and C API Changes: Build and C API Changes<11>. * Porting to Python 2.4: Porting to Python 2 4. * Acknowledgements: Acknowledgements<4>.  File: python.info, Node: PEP 218 Built-In Set Objects, Next: PEP 237 Unifying Long Integers and Integers, Up: What’s New in Python 2 4 1.13.1 PEP 218: Built-In Set Objects ------------------------------------ Python 2.3 introduced the ‘sets’ module. C implementations of set data types have now been added to the Python core as two new built-in types, ‘set(iterable)’ and ‘frozenset(iterable)’. They provide high speed operations for membership testing, for eliminating duplicates from sequences, and for mathematical operations like unions, intersections, differences, and symmetric differences. >>> a = set('abracadabra') # form a set from a string >>> 'z' in a # fast membership testing False >>> a # unique letters in a set(['a', 'r', 'b', 'c', 'd']) >>> ''.join(a) # convert back into a string 'arbcd' >>> b = set('alacazam') # form a second set >>> a - b # letters in a but not in b set(['r', 'd', 'b']) >>> a | b # letters in either a or b set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l']) >>> a & b # letters in both a and b set(['a', 'c']) >>> a ^ b # letters in a or b but not both set(['r', 'd', 'b', 'm', 'z', 'l']) >>> a.add('z') # add a new element >>> a.update('wxy') # add multiple new elements >>> a set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'x', 'z']) >>> a.remove('x') # take one element out >>> a set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'z']) The *note frozenset(): bee. type is an immutable version of *note set(): b6f. Since it is immutable and hashable, it may be used as a dictionary key or as a member of another set. The ‘sets’ module remains in the standard library, and may be useful if you wish to subclass the ‘Set’ or ‘ImmutableSet’ classes. There are currently no plans to deprecate the module. See also ........ PEP 218(1) - Adding a Built-In Set Object Type Originally proposed by Greg Wilson and ultimately implemented by Raymond Hettinger. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0218  File: python.info, Node: PEP 237 Unifying Long Integers and Integers, Next: PEP 289 Generator Expressions, Prev: PEP 218 Built-In Set Objects, Up: What’s New in Python 2 4 1.13.2 PEP 237: Unifying Long Integers and Integers --------------------------------------------------- The lengthy transition process for this PEP, begun in Python 2.2, takes another step forward in Python 2.4. In 2.3, certain integer operations that would behave differently after int/long unification triggered *note FutureWarning: 325. warnings and returned values limited to 32 or 64 bits (depending on your platform). In 2.4, these expressions no longer produce a warning and instead produce a different result that’s usually a long integer. The problematic expressions are primarily left shifts and lengthy hexadecimal and octal constants. For example, ‘2 << 32’ results in a warning in 2.3, evaluating to 0 on 32-bit platforms. In Python 2.4, this expression now returns the correct answer, 8589934592. See also ........ PEP 237(1) - Unifying Long Integers and Integers Original PEP written by Moshe Zadka and GvR. The changes for 2.4 were implemented by Kalle Svensson. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0237  File: python.info, Node: PEP 289 Generator Expressions, Next: PEP 292 Simpler String Substitutions, Prev: PEP 237 Unifying Long Integers and Integers, Up: What’s New in Python 2 4 1.13.3 PEP 289: Generator Expressions ------------------------------------- The iterator feature introduced in Python 2.2 and the *note itertools: a3. module make it easier to write programs that loop through large data sets without having the entire data set in memory at one time. List comprehensions don’t fit into this picture very well because they produce a Python list object containing all of the items. This unavoidably pulls all of the objects into memory, which can be a problem if your data set is very large. When trying to write a functionally-styled program, it would be natural to write something like: links = [link for link in get_all_links() if not link.followed] for link in links: ... instead of for link in get_all_links(): if link.followed: continue ... The first form is more concise and perhaps more readable, but if you’re dealing with a large number of link objects you’d have to write the second form to avoid having all link objects in memory at the same time. Generator expressions work similarly to list comprehensions but don’t materialize the entire list; instead they create a generator that will return elements one by one. The above example could be written as: links = (link for link in get_all_links() if not link.followed) for link in links: ... Generator expressions always have to be written inside parentheses, as in the above example. The parentheses signalling a function call also count, so if you want to create an iterator that will be immediately passed to a function you could write: print sum(obj.count for obj in list_all_objects()) Generator expressions differ from list comprehensions in various small ways. Most notably, the loop variable (`obj' in the above example) is not accessible outside of the generator expression. List comprehensions leave the variable assigned to its last value; future versions of Python will change this, making list comprehensions match generator expressions in this respect. See also ........ PEP 289(1) - Generator Expressions Proposed by Raymond Hettinger and implemented by Jiwon Seo with early efforts steered by Hye-Shik Chang. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0289  File: python.info, Node: PEP 292 Simpler String Substitutions, Next: PEP 318 Decorators for Functions and Methods, Prev: PEP 289 Generator Expressions, Up: What’s New in Python 2 4 1.13.4 PEP 292: Simpler String Substitutions -------------------------------------------- Some new classes in the standard library provide an alternative mechanism for substituting variables into strings; this style of substitution may be better for applications where untrained users need to edit templates. The usual way of substituting variables by name is the ‘%’ operator: >>> '%(page)i: %(title)s' % {'page':2, 'title': 'The Best of Times'} '2: The Best of Times' When writing the template string, it can be easy to forget the ‘i’ or ‘s’ after the closing parenthesis. This isn’t a big problem if the template is in a Python module, because you run the code, get an “Unsupported format character” *note ValueError: 1fb, and fix the problem. However, consider an application such as Mailman where template strings or translations are being edited by users who aren’t aware of the Python language. The format string’s syntax is complicated to explain to such users, and if they make a mistake, it’s difficult to provide helpful feedback to them. PEP 292 adds a ‘Template’ class to the *note string: f6. module that uses ‘$’ to indicate a substitution: >>> import string >>> t = string.Template('$page: $title') >>> t.substitute({'page':2, 'title': 'The Best of Times'}) '2: The Best of Times' If a key is missing from the dictionary, the ‘substitute()’ method will raise a *note KeyError: 2c7. There’s also a ‘safe_substitute()’ method that ignores missing keys: >>> t = string.Template('$page: $title') >>> t.safe_substitute({'page':3}) '3: $title' See also ........ PEP 292(1) - Simpler String Substitutions Written and implemented by Barry Warsaw. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0292  File: python.info, Node: PEP 318 Decorators for Functions and Methods, Next: PEP 322 Reverse Iteration, Prev: PEP 292 Simpler String Substitutions, Up: What’s New in Python 2 4 1.13.5 PEP 318: Decorators for Functions and Methods ---------------------------------------------------- Python 2.2 extended Python’s object model by adding static methods and class methods, but it didn’t extend Python’s syntax to provide any new way of defining static or class methods. Instead, you had to write a *note def: dbe. statement in the usual way, and pass the resulting method to a *note staticmethod(): 1d9. or *note classmethod(): 1d8. function that would wrap up the function as a method of the new type. Your code would look like this: class C: def meth (cls): ... meth = classmethod(meth) # Rebind name to wrapped-up class method If the method was very long, it would be easy to miss or forget the *note classmethod(): 1d8. invocation after the function body. The intention was always to add some syntax to make such definitions more readable, but at the time of 2.2’s release a good syntax was not obvious. Today a good syntax `still' isn’t obvious but users are asking for easier access to the feature; a new syntactic feature has been added to meet this need. The new feature is called “function decorators”. The name comes from the idea that *note classmethod(): 1d8, *note staticmethod(): 1d9, and friends are storing additional information on a function object; they’re `decorating' functions with more details. The notation borrows from Java and uses the ‘'@'’ character as an indicator. Using the new syntax, the example above would be written: class C: @classmethod def meth (cls): ... The ‘@classmethod’ is shorthand for the ‘meth=classmethod(meth)’ assignment. More generally, if you have the following: @A @B @C def f (): ... It’s equivalent to the following pre-decorator code: def f(): ... f = A(B(C(f))) Decorators must come on the line before a function definition, one decorator per line, and can’t be on the same line as the def statement, meaning that ‘@A def f(): ...’ is illegal. You can only decorate function definitions, either at the module level or inside a class; you can’t decorate class definitions. A decorator is just a function that takes the function to be decorated as an argument and returns either the same function or some new object. The return value of the decorator need not be callable (though it typically is), unless further decorators will be applied to the result. It’s easy to write your own decorators. The following simple example just sets an attribute on the function object: >>> def deco(func): ... func.attr = 'decorated' ... return func ... >>> @deco ... def f(): pass ... >>> f >>> f.attr 'decorated' >>> As a slightly more realistic example, the following decorator checks that the supplied argument is an integer: def require_int (func): def wrapper (arg): assert isinstance(arg, int) return func(arg) return wrapper @require_int def p1 (arg): print arg @require_int def p2(arg): print arg*2 An example in PEP 318(1) contains a fancier version of this idea that lets you both specify the required type and check the returned type. Decorator functions can take arguments. If arguments are supplied, your decorator function is called with only those arguments and must return a new decorator function; this function must take a single function and return a function, as previously described. In other words, ‘@A @B @C(args)’ becomes: def f(): ... _deco = C(args) f = A(B(_deco(f))) Getting this right can be slightly brain-bending, but it’s not too difficult. A small related change makes the ‘func_name’ attribute of functions writable. This attribute is used to display function names in tracebacks, so decorators should change the name of any new function that’s constructed and returned. See also ........ PEP 318(2) - Decorators for Functions, Methods and Classes Written by Kevin D. Smith, Jim Jewett, and Skip Montanaro. Several people wrote patches implementing function decorators, but the one that was actually checked in was patch #979728, written by Mark Russell. ‘https://wiki.python.org/moin/PythonDecoratorLibrary’ This Wiki page contains several examples of decorators. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0318 (2) https://www.python.org/dev/peps/pep-0318  File: python.info, Node: PEP 322 Reverse Iteration, Next: PEP 324 New subprocess Module, Prev: PEP 318 Decorators for Functions and Methods, Up: What’s New in Python 2 4 1.13.6 PEP 322: Reverse Iteration --------------------------------- A new built-in function, ‘reversed(seq)’, takes a sequence and returns an iterator that loops over the elements of the sequence in reverse order. >>> for i in reversed(xrange(1,4)): ... print i ... 3 2 1 Compared to extended slicing, such as ‘range(1,4)[::-1]’, *note reversed(): 18e. is easier to read, runs faster, and uses substantially less memory. Note that *note reversed(): 18e. only accepts sequences, not arbitrary iterators. If you want to reverse an iterator, first convert it to a list with *note list(): 262. >>> input = open('/etc/passwd', 'r') >>> for line in reversed(list(input)): ... print line ... root:*:0:0:System Administrator:/var/root:/bin/tcsh ... See also ........ PEP 322(1) - Reverse Iteration Written and implemented by Raymond Hettinger. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0322  File: python.info, Node: PEP 324 New subprocess Module, Next: PEP 327 Decimal Data Type, Prev: PEP 322 Reverse Iteration, Up: What’s New in Python 2 4 1.13.7 PEP 324: New subprocess Module ------------------------------------- The standard library provides a number of ways to execute a subprocess, offering different features and different levels of complexity. ‘os.system(command)’ is easy to use, but slow (it runs a shell process which executes the command) and dangerous (you have to be careful about escaping the shell’s metacharacters). The ‘popen2’ module offers classes that can capture standard output and standard error from the subprocess, but the naming is confusing. The *note subprocess: f9. module cleans this up, providing a unified interface that offers all the features you might need. Instead of ‘popen2’’s collection of classes, *note subprocess: f9. contains a single class called ‘Popen’ whose constructor supports a number of different keyword arguments. class Popen(args, bufsize=0, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=False, shell=False, cwd=None, env=None, universal_newlines=False, startupinfo=None, creationflags=0): `args' is commonly a sequence of strings that will be the arguments to the program executed as the subprocess. (If the `shell' argument is true, `args' can be a string which will then be passed on to the shell for interpretation, just as *note os.system(): dc1. does.) `stdin', `stdout', and `stderr' specify what the subprocess’s input, output, and error streams will be. You can provide a file object or a file descriptor, or you can use the constant ‘subprocess.PIPE’ to create a pipe between the subprocess and the parent. The constructor has a number of handy options: * `close_fds' requests that all file descriptors be closed before running the subprocess. * `cwd' specifies the working directory in which the subprocess will be executed (defaulting to whatever the parent’s working directory is). * `env' is a dictionary specifying environment variables. * `preexec_fn' is a function that gets called before the child is started. * `universal_newlines' opens the child’s input and output using Python’s *note universal newlines: 5f4. feature. Once you’ve created the ‘Popen’ instance, you can call its ‘wait()’ method to pause until the subprocess has exited, ‘poll()’ to check if it’s exited without pausing, or ‘communicate(data)’ to send the string `data' to the subprocess’s standard input. ‘communicate(data)’ then reads any data that the subprocess has sent to its standard output or standard error, returning a tuple ‘(stdout_data, stderr_data)’. ‘call()’ is a shortcut that passes its arguments along to the ‘Popen’ constructor, waits for the command to complete, and returns the status code of the subprocess. It can serve as a safer analog to *note os.system(): dc1.: sts = subprocess.call(['dpkg', '-i', '/tmp/new-package.deb']) if sts == 0: # Success ... else: # dpkg returned an error ... The command is invoked without use of the shell. If you really do want to use the shell, you can add ‘shell=True’ as a keyword argument and provide a string instead of a sequence: sts = subprocess.call('dpkg -i /tmp/new-package.deb', shell=True) The PEP takes various examples of shell and Python code and shows how they’d be translated into Python code that uses *note subprocess: f9. Reading this section of the PEP is highly recommended. See also ........ PEP 324(1) - subprocess - New process module Written and implemented by Peter Åstrand, with assistance from Fredrik Lundh and others. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0324  File: python.info, Node: PEP 327 Decimal Data Type, Next: PEP 328 Multi-line Imports, Prev: PEP 324 New subprocess Module, Up: What’s New in Python 2 4 1.13.8 PEP 327: Decimal Data Type --------------------------------- Python has always supported floating-point (FP) numbers, based on the underlying C ‘double’ type, as a data type. However, while most programming languages provide a floating-point type, many people (even programmers) are unaware that floating-point numbers don’t represent certain decimal fractions accurately. The new ‘Decimal’ type can represent these fractions accurately, up to a user-specified precision limit. * Menu: * Why is Decimal needed?:: * The Decimal type:: * The Context type::  File: python.info, Node: Why is Decimal needed?, Next: The Decimal type, Up: PEP 327 Decimal Data Type 1.13.8.1 Why is Decimal needed? ............................... The limitations arise from the representation used for floating-point numbers. FP numbers are made up of three components: * The sign, which is positive or negative. * The mantissa, which is a single-digit binary number followed by a fractional part. For example, ‘1.01’ in base-2 notation is ‘1 + 0/2 + 1/4’, or 1.25 in decimal notation. * The exponent, which tells where the decimal point is located in the number represented. For example, the number 1.25 has positive sign, a mantissa value of 1.01 (in binary), and an exponent of 0 (the decimal point doesn’t need to be shifted). The number 5 has the same sign and mantissa, but the exponent is 2 because the mantissa is multiplied by 4 (2 to the power of the exponent 2); 1.25 * 4 equals 5. Modern systems usually provide floating-point support that conforms to a standard called IEEE 754. C’s ‘double’ type is usually implemented as a 64-bit IEEE 754 number, which uses 52 bits of space for the mantissa. This means that numbers can only be specified to 52 bits of precision. If you’re trying to represent numbers whose expansion repeats endlessly, the expansion is cut off after 52 bits. Unfortunately, most software needs to produce output in base 10, and common fractions in base 10 are often repeating decimals in binary. For example, 1.1 decimal is binary ‘1.0001100110011 ...’; .1 = 1/16 + 1/32 + 1/256 plus an infinite number of additional terms. IEEE 754 has to chop off that infinitely repeated decimal after 52 digits, so the representation is slightly inaccurate. Sometimes you can see this inaccuracy when the number is printed: >>> 1.1 1.1000000000000001 The inaccuracy isn’t always visible when you print the number because the FP-to-decimal-string conversion is provided by the C library, and most C libraries try to produce sensible output. Even if it’s not displayed, however, the inaccuracy is still there and subsequent operations can magnify the error. For many applications this doesn’t matter. If I’m plotting points and displaying them on my monitor, the difference between 1.1 and 1.1000000000000001 is too small to be visible. Reports often limit output to a certain number of decimal places, and if you round the number to two or three or even eight decimal places, the error is never apparent. However, for applications where it does matter, it’s a lot of work to implement your own custom arithmetic routines. Hence, the ‘Decimal’ type was created.  File: python.info, Node: The Decimal type, Next: The Context type, Prev: Why is Decimal needed?, Up: PEP 327 Decimal Data Type 1.13.8.2 The ‘Decimal’ type ........................... A new module, *note decimal: 36, was added to Python’s standard library. It contains two classes, ‘Decimal’ and ‘Context’. ‘Decimal’ instances represent numbers, and ‘Context’ instances are used to wrap up various settings such as the precision and default rounding mode. ‘Decimal’ instances are immutable, like regular Python integers and FP numbers; once it’s been created, you can’t change the value an instance represents. ‘Decimal’ instances can be created from integers or strings: >>> import decimal >>> decimal.Decimal(1972) Decimal("1972") >>> decimal.Decimal("1.1") Decimal("1.1") You can also provide tuples containing the sign, the mantissa represented as a tuple of decimal digits, and the exponent: >>> decimal.Decimal((1, (1, 4, 7, 5), -2)) Decimal("-14.75") Cautionary note: the sign bit is a Boolean value, so 0 is positive and 1 is negative. Converting from floating-point numbers poses a bit of a problem: should the FP number representing 1.1 turn into the decimal number for exactly 1.1, or for 1.1 plus whatever inaccuracies are introduced? The decision was to dodge the issue and leave such a conversion out of the API. Instead, you should convert the floating-point number into a string using the desired precision and pass the string to the ‘Decimal’ constructor: >>> f = 1.1 >>> decimal.Decimal(str(f)) Decimal("1.1") >>> decimal.Decimal('%.12f' % f) Decimal("1.100000000000") Once you have ‘Decimal’ instances, you can perform the usual mathematical operations on them. One limitation: exponentiation requires an integer exponent: >>> a = decimal.Decimal('35.72') >>> b = decimal.Decimal('1.73') >>> a+b Decimal("37.45") >>> a-b Decimal("33.99") >>> a*b Decimal("61.7956") >>> a/b Decimal("20.64739884393063583815028902") >>> a ** 2 Decimal("1275.9184") >>> a**b Traceback (most recent call last): ... decimal.InvalidOperation: x ** (non-integer) You can combine ‘Decimal’ instances with integers, but not with floating-point numbers: >>> a + 4 Decimal("39.72") >>> a + 4.5 Traceback (most recent call last): ... TypeError: You can interact Decimal only with int, long or Decimal data types. >>> ‘Decimal’ numbers can be used with the *note math: b1. and *note cmath: 19. modules, but note that they’ll be immediately converted to floating-point numbers before the operation is performed, resulting in a possible loss of precision and accuracy. You’ll also get back a regular floating-point number and not a ‘Decimal’. >>> import math, cmath >>> d = decimal.Decimal('123456789012.345') >>> math.sqrt(d) 351364.18288201344 >>> cmath.sqrt(-d) 351364.18288201344j ‘Decimal’ instances have a ‘sqrt()’ method that returns a ‘Decimal’, but if you need other things such as trigonometric functions you’ll have to implement them. >>> d.sqrt() Decimal("351364.1828820134592177245001")  File: python.info, Node: The Context type, Prev: The Decimal type, Up: PEP 327 Decimal Data Type 1.13.8.3 The ‘Context’ type ........................... Instances of the ‘Context’ class encapsulate several settings for decimal operations: * ‘prec’ is the precision, the number of decimal places. * ‘rounding’ specifies the rounding mode. The *note decimal: 36. module has constants for the various possibilities: ‘ROUND_DOWN’, ‘ROUND_CEILING’, ‘ROUND_HALF_EVEN’, and various others. * ‘traps’ is a dictionary specifying what happens on encountering certain error conditions: either an exception is raised or a value is returned. Some examples of error conditions are division by zero, loss of precision, and overflow. There’s a thread-local default context available by calling ‘getcontext()’; you can change the properties of this context to alter the default precision, rounding, or trap handling. The following example shows the effect of changing the precision of the default context: >>> decimal.getcontext().prec 28 >>> decimal.Decimal(1) / decimal.Decimal(7) Decimal("0.1428571428571428571428571429") >>> decimal.getcontext().prec = 9 >>> decimal.Decimal(1) / decimal.Decimal(7) Decimal("0.142857143") The default action for error conditions is selectable; the module can either return a special value such as infinity or not-a-number, or exceptions can be raised: >>> decimal.Decimal(1) / decimal.Decimal(0) Traceback (most recent call last): ... decimal.DivisionByZero: x / 0 >>> decimal.getcontext().traps[decimal.DivisionByZero] = False >>> decimal.Decimal(1) / decimal.Decimal(0) Decimal("Infinity") >>> The ‘Context’ instance also has various methods for formatting numbers such as ‘to_eng_string()’ and ‘to_sci_string()’. For more information, see the documentation for the *note decimal: 36. module, which includes a quick-start tutorial and a reference. See also ........ PEP 327(1) - Decimal Data Type Written by Facundo Batista and implemented by Facundo Batista, Eric Price, Raymond Hettinger, Aahz, and Tim Peters. ‘http://www.lahey.com/float.htm’ The article uses Fortran code to illustrate many of the problems that floating-point inaccuracy can cause. ‘http://speleotrove.com/decimal/’ A description of a decimal-based representation. This representation is being proposed as a standard, and underlies the new Python decimal type. Much of this material was written by Mike Cowlishaw, designer of the Rexx language. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0327  File: python.info, Node: PEP 328 Multi-line Imports, Next: PEP 331 Locale-Independent Float/String Conversions, Prev: PEP 327 Decimal Data Type, Up: What’s New in Python 2 4 1.13.9 PEP 328: Multi-line Imports ---------------------------------- One language change is a small syntactic tweak aimed at making it easier to import many names from a module. In a ‘from module import names’ statement, `names' is a sequence of names separated by commas. If the sequence is very long, you can either write multiple imports from the same module, or you can use backslashes to escape the line endings like this: from SimpleXMLRPCServer import SimpleXMLRPCServer,\ SimpleXMLRPCRequestHandler,\ CGIXMLRPCRequestHandler,\ resolve_dotted_attribute The syntactic change in Python 2.4 simply allows putting the names within parentheses. Python ignores newlines within a parenthesized expression, so the backslashes are no longer needed: from SimpleXMLRPCServer import (SimpleXMLRPCServer, SimpleXMLRPCRequestHandler, CGIXMLRPCRequestHandler, resolve_dotted_attribute) The PEP also proposes that all *note import: c1d. statements be absolute imports, with a leading ‘.’ character to indicate a relative import. This part of the PEP was not implemented for Python 2.4, but was completed for Python 2.5. See also ........ PEP 328(1) - Imports: Multi-Line and Absolute/Relative Written by Aahz. Multi-line imports were implemented by Dima Dorfman. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0328  File: python.info, Node: PEP 331 Locale-Independent Float/String Conversions, Next: Other Language Changes<12>, Prev: PEP 328 Multi-line Imports, Up: What’s New in Python 2 4 1.13.10 PEP 331: Locale-Independent Float/String Conversions ------------------------------------------------------------ The *note locale: a9. modules lets Python software select various conversions and display conventions that are localized to a particular country or language. However, the module was careful to not change the numeric locale because various functions in Python’s implementation required that the numeric locale remain set to the ‘'C'’ locale. Often this was because the code was using the C library’s ‘atof()’ function. Not setting the numeric locale caused trouble for extensions that used third-party C libraries, however, because they wouldn’t have the correct locale set. The motivating example was GTK+, whose user interface widgets weren’t displaying numbers in the current locale. The solution described in the PEP is to add three new functions to the Python API that perform ASCII-only conversions, ignoring the locale setting: * ‘PyOS_ascii_strtod(str, ptr)’ and ‘PyOS_ascii_atof(str, ptr)’ both convert a string to a C ‘double’. * ‘PyOS_ascii_formatd(buffer, buf_len, format, d)’ converts a ‘double’ to an ASCII string. The code for these functions came from the GLib library (‘https://developer.gnome.org/glib/stable/’), whose developers kindly relicensed the relevant functions and donated them to the Python Software Foundation. The *note locale: a9. module can now change the numeric locale, letting extensions such as GTK+ produce the correct results. See also ........ PEP 331(1) - Locale-Independent Float/String Conversions Written by Christian R. Reis, and implemented by Gustavo Carneiro. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0331  File: python.info, Node: Other Language Changes<12>, Next: New Improved and Deprecated Modules<3>, Prev: PEP 331 Locale-Independent Float/String Conversions, Up: What’s New in Python 2 4 1.13.11 Other Language Changes ------------------------------ Here are all of the changes that Python 2.4 makes to the core Python language. * Decorators for functions and methods were added ( PEP 318(1)). * Built-in *note set(): b6f. and *note frozenset(): bee. types were added ( PEP 218(2)). Other new built-ins include the ‘reversed(seq)’ function ( PEP 322(3)). * Generator expressions were added ( PEP 289(4)). * Certain numeric expressions no longer return values restricted to 32 or 64 bits ( PEP 237(5)). * You can now put parentheses around the list of names in a ‘from module import names’ statement ( PEP 328(6)). * The *note dict.update(): dc9. method now accepts the same argument forms as the *note dict: 1b8. constructor. This includes any mapping, any iterable of key/value pairs, and keyword arguments. (Contributed by Raymond Hettinger.) * The string methods ‘ljust()’, ‘rjust()’, and ‘center()’ now take an optional argument for specifying a fill character other than a space. (Contributed by Raymond Hettinger.) * Strings also gained an ‘rsplit()’ method that works like the ‘split()’ method but splits from the end of the string. (Contributed by Sean Reifschneider.) >>> 'www.python.org'.split('.', 1) ['www', 'python.org'] 'www.python.org'.rsplit('.', 1) ['www.python', 'org'] * Three keyword parameters, `cmp', `key', and `reverse', were added to the ‘sort()’ method of lists. These parameters make some common usages of ‘sort()’ simpler. All of these parameters are optional. For the `cmp' parameter, the value should be a comparison function that takes two parameters and returns -1, 0, or +1 depending on how the parameters compare. This function will then be used to sort the list. Previously this was the only parameter that could be provided to ‘sort()’. `key' should be a single-parameter function that takes a list element and returns a comparison key for the element. The list is then sorted using the comparison keys. The following example sorts a list case-insensitively: >>> L = ['A', 'b', 'c', 'D'] >>> L.sort() # Case-sensitive sort >>> L ['A', 'D', 'b', 'c'] >>> # Using 'key' parameter to sort list >>> L.sort(key=lambda x: x.lower()) >>> L ['A', 'b', 'c', 'D'] >>> # Old-fashioned way >>> L.sort(cmp=lambda x,y: cmp(x.lower(), y.lower())) >>> L ['A', 'b', 'c', 'D'] The last example, which uses the `cmp' parameter, is the old way to perform a case-insensitive sort. It works but is slower than using a `key' parameter. Using `key' calls ‘lower()’ method once for each element in the list while using `cmp' will call it twice for each comparison, so using `key' saves on invocations of the ‘lower()’ method. For simple key functions and comparison functions, it is often possible to avoid a *note lambda: c2f. expression by using an unbound method instead. For example, the above case-insensitive sort is best written as: >>> L.sort(key=str.lower) >>> L ['A', 'b', 'c', 'D'] Finally, the `reverse' parameter takes a Boolean value. If the value is true, the list will be sorted into reverse order. Instead of ‘L.sort(); L.reverse()’, you can now write ‘L.sort(reverse=True)’. The results of sorting are now guaranteed to be stable. This means that two entries with equal keys will be returned in the same order as they were input. For example, you can sort a list of people by name, and then sort the list by age, resulting in a list sorted by age where people with the same age are in name-sorted order. (All changes to ‘sort()’ contributed by Raymond Hettinger.) * There is a new built-in function ‘sorted(iterable)’ that works like the in-place *note list.sort(): 445. method but can be used in expressions. The differences are: * the input may be any iterable; * a newly formed copy is sorted, leaving the original intact; and * the expression returns the new sorted copy >>> L = [9,7,8,3,2,4,1,6,5] >>> [10+i for i in sorted(L)] # usable in a list comprehension [11, 12, 13, 14, 15, 16, 17, 18, 19] >>> L # original is left unchanged [9,7,8,3,2,4,1,6,5] >>> sorted('Monty Python') # any iterable may be an input [' ', 'M', 'P', 'h', 'n', 'n', 'o', 'o', 't', 't', 'y', 'y'] >>> # List the contents of a dict sorted by key values >>> colormap = dict(red=1, blue=2, green=3, black=4, yellow=5) >>> for k, v in sorted(colormap.iteritems()): ... print k, v ... black 4 blue 2 green 3 red 1 yellow 5 (Contributed by Raymond Hettinger.) * Integer operations will no longer trigger an ‘OverflowWarning’. The ‘OverflowWarning’ warning will disappear in Python 2.5. * The interpreter gained a new switch, *note -m: 337, that takes a name, searches for the corresponding module on ‘sys.path’, and runs the module as a script. For example, you can now run the Python profiler with ‘python -m profile’. (Contributed by Nick Coghlan.) * The ‘eval(expr, globals, locals)’ and ‘execfile(filename, globals, locals)’ functions and the ‘exec’ statement now accept any mapping type for the `locals' parameter. Previously this had to be a regular Python dictionary. (Contributed by Raymond Hettinger.) * The *note zip(): c32. built-in function and ‘itertools.izip()’ now return an empty list if called with no arguments. Previously they raised a *note TypeError: 192. exception. This makes them more suitable for use with variable length argument lists: >>> def transpose(array): ... return zip(*array) ... >>> transpose([(1,2,3), (4,5,6)]) [(1, 4), (2, 5), (3, 6)] >>> transpose([]) [] (Contributed by Raymond Hettinger.) * Encountering a failure while importing a module no longer leaves a partially-initialized module object in ‘sys.modules’. The incomplete module object left behind would fool further imports of the same module into succeeding, leading to confusing errors. (Fixed by Tim Peters.) * *note None: 157. is now a constant; code that binds a new value to the name ‘None’ is now a syntax error. (Contributed by Raymond Hettinger.) * Menu: * Optimizations: Optimizations<11>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0318 (2) https://www.python.org/dev/peps/pep-0218 (3) https://www.python.org/dev/peps/pep-0322 (4) https://www.python.org/dev/peps/pep-0289 (5) https://www.python.org/dev/peps/pep-0237 (6) https://www.python.org/dev/peps/pep-0328  File: python.info, Node: Optimizations<11>, Up: Other Language Changes<12> 1.13.11.1 Optimizations ....................... * The inner loops for list and tuple slicing were optimized and now run about one-third faster. The inner loops for dictionaries were also optimized, resulting in performance boosts for ‘keys()’, ‘values()’, ‘items()’, ‘iterkeys()’, ‘itervalues()’, and ‘iteritems()’. (Contributed by Raymond Hettinger.) * The machinery for growing and shrinking lists was optimized for speed and for space efficiency. Appending and popping from lists now runs faster due to more efficient code paths and less frequent use of the underlying system ‘realloc()’. List comprehensions also benefit. ‘list.extend()’ was also optimized and no longer converts its argument into a temporary list before extending the base list. (Contributed by Raymond Hettinger.) * *note list(): 262, *note tuple(): 47e, *note map(): c2d, *note filter(): c2e, and *note zip(): c32. now run several times faster with non-sequence arguments that supply a *note __len__(): dcb. method. (Contributed by Raymond Hettinger.) * The methods ‘list.__getitem__()’, ‘dict.__getitem__()’, and ‘dict.__contains__()’ are now implemented as ‘method_descriptor’ objects rather than ‘wrapper_descriptor’ objects. This form of access doubles their performance and makes them more suitable for use as arguments to functionals: ‘map(mydict.__getitem__, keylist)’. (Contributed by Raymond Hettinger.) * Added a new opcode, ‘LIST_APPEND’, that simplifies the generated bytecode for list comprehensions and speeds them up by about a third. (Contributed by Raymond Hettinger.) * The peephole bytecode optimizer has been improved to produce shorter, faster bytecode; remarkably, the resulting bytecode is more readable. (Enhanced by Raymond Hettinger.) * String concatenations in statements of the form ‘s = s + "abc"’ and ‘s += "abc"’ are now performed more efficiently in certain circumstances. This optimization won’t be present in other Python implementations such as Jython, so you shouldn’t rely on it; using the ‘join()’ method of strings is still recommended when you want to efficiently glue a large number of strings together. (Contributed by Armin Rigo.) The net result of the 2.4 optimizations is that Python 2.4 runs the pystone benchmark around 5% faster than Python 2.3 and 35% faster than Python 2.2. (pystone is not a particularly good benchmark, but it’s the most commonly used measurement of Python’s performance. Your own applications may show greater or smaller benefits from Python 2.4.)  File: python.info, Node: New Improved and Deprecated Modules<3>, Next: Build and C API Changes<11>, Prev: Other Language Changes<12>, Up: What’s New in Python 2 4 1.13.12 New, Improved, and Deprecated Modules --------------------------------------------- As usual, Python’s standard library received a number of enhancements and bug fixes. Here’s a partial list of the most notable changes, sorted alphabetically by module name. Consult the ‘Misc/NEWS’ file in the source tree for a more complete list of changes, or look through the CVS logs for all the details. * The *note asyncore: b. module’s ‘loop()’ function now has a `count' parameter that lets you perform a limited number of passes through the polling loop. The default is still to loop forever. * The *note base64: e. module now has more complete RFC 3548(1) support for Base64, Base32, and Base16 encoding and decoding, including optional case folding and optional alternative alphabets. (Contributed by Barry Warsaw.) * The *note bisect: 12. module now has an underlying C implementation for improved performance. (Contributed by Dmitry Vasiliev.) * The CJKCodecs collections of East Asian codecs, maintained by Hye-Shik Chang, was integrated into 2.4. The new encodings are: * Chinese (PRC): gb2312, gbk, gb18030, big5hkscs, hz * Chinese (ROC): big5, cp950 * Japanese: cp932, euc-jis-2004, euc-jp, euc-jisx0213, iso-2022-jp, iso-2022-jp-1, iso-2022-jp-2, iso-2022-jp-3, iso-2022-jp-ext, iso-2022-jp-2004, shift-jis, shift-jisx0213, shift-jis-2004 * Korean: cp949, euc-kr, johab, iso-2022-kr * Some other new encodings were added: HP Roman8, ISO_8859-11, ISO_8859-16, PCTP-154, and TIS-620. * The UTF-8 and UTF-16 codecs now cope better with receiving partial input. Previously the ‘StreamReader’ class would try to read more data, making it impossible to resume decoding from the stream. The ‘read()’ method will now return as much data as it can and future calls will resume decoding where previous ones left off. (Implemented by Walter Dörwald.) * There is a new *note collections: 1e. module for various specialized collection datatypes. Currently it contains just one type, ‘deque’, a double-ended queue that supports efficiently adding and removing elements from either end: >>> from collections import deque >>> d = deque('ghi') # make a new deque with three items >>> d.append('j') # add a new entry to the right side >>> d.appendleft('f') # add a new entry to the left side >>> d # show the representation of the deque deque(['f', 'g', 'h', 'i', 'j']) >>> d.pop() # return and remove the rightmost item 'j' >>> d.popleft() # return and remove the leftmost item 'f' >>> list(d) # list the contents of the deque ['g', 'h', 'i'] >>> 'h' in d # search the deque True Several modules, such as the ‘Queue’ and *note threading: 109. modules, now take advantage of *note collections.deque: 531. for improved performance. (Contributed by Raymond Hettinger.) * The ‘ConfigParser’ classes have been enhanced slightly. The ‘read()’ method now returns a list of the files that were successfully parsed, and the *note set(): b6f. method raises *note TypeError: 192. if passed a `value' argument that isn’t a string. (Contributed by John Belmonte and David Goodger.) * The *note curses: 2c. module now supports the ncurses extension ‘use_default_colors()’. On platforms where the terminal supports transparency, this makes it possible to use a transparent background. (Contributed by Jörg Lehmann.) * The *note difflib: 37. module now includes an ‘HtmlDiff’ class that creates an HTML table showing a side by side comparison of two versions of a text. (Contributed by Dan Gass.) * The *note email: 69. package was updated to version 3.0, which dropped various deprecated APIs and removes support for Python versions earlier than 2.3. The 3.0 version of the package uses a new incremental parser for MIME messages, available in the ‘email.FeedParser’ module. The new parser doesn’t require reading the entire message into memory, and doesn’t raise exceptions if a message is malformed; instead it records any problems in the ‘defect’ attribute of the message. (Developed by Anthony Baxter, Barry Warsaw, Thomas Wouters, and others.) * The *note heapq: 8e. module has been converted to C. The resulting tenfold improvement in speed makes the module suitable for handling high volumes of data. In addition, the module has two new functions ‘nlargest()’ and ‘nsmallest()’ that use heaps to find the N largest or smallest values in a dataset without the expense of a full sort. (Contributed by Raymond Hettinger.) * The ‘httplib’ module now contains constants for HTTP status codes defined in various HTTP-related RFC documents. Constants have names such as ‘OK’, ‘CREATED’, ‘CONTINUE’, and ‘MOVED_PERMANENTLY’; use pydoc to get a full list. (Contributed by Andrew Eland.) * The *note imaplib: 98. module now supports IMAP’s THREAD command (contributed by Yves Dionne) and new ‘deleteacl()’ and ‘myrights()’ methods (contributed by Arnaud Mazin). * The *note itertools: a3. module gained a ‘groupby(iterable[, *func*])’ function. `iterable' is something that can be iterated over to return a stream of elements, and the optional `func' parameter is a function that takes an element and returns a key value; if omitted, the key is simply the element itself. ‘groupby()’ then groups the elements into subsequences which have matching values of the key, and returns a series of 2-tuples containing the key value and an iterator over the subsequence. Here’s an example to make this clearer. The `key' function simply returns whether a number is even or odd, so the result of ‘groupby()’ is to return consecutive runs of odd or even numbers. >>> import itertools >>> L = [2, 4, 6, 7, 8, 9, 11, 12, 14] >>> for key_val, it in itertools.groupby(L, lambda x: x % 2): ... print key_val, list(it) ... 0 [2, 4, 6] 1 [7] 0 [8] 1 [9, 11] 0 [12, 14] >>> ‘groupby()’ is typically used with sorted input. The logic for ‘groupby()’ is similar to the Unix ‘uniq’ filter which makes it handy for eliminating, counting, or identifying duplicate elements: >>> word = 'abracadabra' >>> letters = sorted(word) # Turn string into a sorted list of letters >>> letters ['a', 'a', 'a', 'a', 'a', 'b', 'b', 'c', 'd', 'r', 'r'] >>> for k, g in itertools.groupby(letters): ... print k, list(g) ... a ['a', 'a', 'a', 'a', 'a'] b ['b', 'b'] c ['c'] d ['d'] r ['r', 'r'] >>> # List unique letters >>> [k for k, g in groupby(letters)] ['a', 'b', 'c', 'd', 'r'] >>> # Count letter occurrences >>> [(k, len(list(g))) for k, g in groupby(letters)] [('a', 5), ('b', 2), ('c', 1), ('d', 1), ('r', 2)] (Contributed by Hye-Shik Chang.) * *note itertools: a3. also gained a function named ‘tee(iterator, N)’ that returns `N' independent iterators that replicate `iterator'. If `N' is omitted, the default is 2. >>> L = [1,2,3] >>> i1, i2 = itertools.tee(L) >>> i1,i2 (, ) >>> list(i1) # Run the first iterator to exhaustion [1, 2, 3] >>> list(i2) # Run the second iterator to exhaustion [1, 2, 3] Note that ‘tee()’ has to keep copies of the values returned by the iterator; in the worst case, it may need to keep all of them. This should therefore be used carefully if the leading iterator can run far ahead of the trailing iterator in a long stream of inputs. If the separation is large, then you might as well use *note list(): 262. instead. When the iterators track closely with one another, ‘tee()’ is ideal. Possible applications include bookmarking, windowing, or lookahead iterators. (Contributed by Raymond Hettinger.) * A number of functions were added to the *note locale: a9. module, such as ‘bind_textdomain_codeset()’ to specify a particular encoding and a family of ‘l*gettext()’ functions that return messages in the chosen encoding. (Contributed by Gustavo Niemeyer.) * Some keyword arguments were added to the *note logging: aa. package’s ‘basicConfig()’ function to simplify log configuration. The default behavior is to log messages to standard error, but various keyword arguments can be specified to log to a particular file, change the logging format, or set the logging level. For example: import logging logging.basicConfig(filename='/var/log/application.log', level=0, # Log all messages format='%(levelname):%(process):%(thread):%(message)') Other additions to the *note logging: aa. package include a ‘log(level, msg)’ convenience method, as well as a ‘TimedRotatingFileHandler’ class that rotates its log files at a timed interval. The module already had ‘RotatingFileHandler’, which rotated logs once the file exceeded a certain size. Both classes derive from a new ‘BaseRotatingHandler’ class that can be used to implement other rotating handlers. (Changes implemented by Vinay Sajip.) * The *note marshal: b0. module now shares interned strings on unpacking a data structure. This may shrink the size of certain pickle strings, but the primary effect is to make ‘.pyc’ files significantly smaller. (Contributed by Martin von Löwis.) * The *note nntplib: c0. module’s ‘NNTP’ class gained ‘description()’ and ‘descriptions()’ methods to retrieve newsgroup descriptions for a single group or for a range of groups. (Contributed by Jürgen A. Erhard.) * Two new functions were added to the *note operator: c2. module, ‘attrgetter(attr)’ and ‘itemgetter(index)’. Both functions return callables that take a single argument and return the corresponding attribute or item; these callables make excellent data extractors when used with *note map(): c2d. or *note sorted(): 444. For example: >>> L = [('c', 2), ('d', 1), ('a', 4), ('b', 3)] >>> map(operator.itemgetter(0), L) ['c', 'd', 'a', 'b'] >>> map(operator.itemgetter(1), L) [2, 1, 4, 3] >>> sorted(L, key=operator.itemgetter(1)) # Sort list by second tuple item [('d', 1), ('c', 2), ('b', 3), ('a', 4)] (Contributed by Raymond Hettinger.) * The *note optparse: c3. module was updated in various ways. The module now passes its messages through *note gettext.gettext(): dcd, making it possible to internationalize Optik’s help and error messages. Help messages for options can now include the string ‘'%default'’, which will be replaced by the option’s default value. (Contributed by Greg Ward.) * The long-term plan is to deprecate the ‘rfc822’ module in some future Python release in favor of the *note email: 69. package. To this end, the ‘email.Utils.formatdate()’ function has been changed to make it usable as a replacement for ‘rfc822.formatdate()’. You may want to write new e-mail processing code with this in mind. (Change implemented by Anthony Baxter.) * A new ‘urandom(n)’ function was added to the *note os: c4. module, returning a string containing `n' bytes of random data. This function provides access to platform-specific sources of randomness such as ‘/dev/urandom’ on Linux or the Windows CryptoAPI. (Contributed by Trevor Perrin.) * Another new function: ‘os.path.lexists(path)’ returns true if the file specified by `path' exists, whether or not it’s a symbolic link. This differs from the existing ‘os.path.exists(path)’ function, which returns false if `path' is a symlink that points to a destination that doesn’t exist. (Contributed by Beni Cherniavsky.) * A new ‘getsid()’ function was added to the *note posix: d1. module that underlies the *note os: c4. module. (Contributed by J. Raynor.) * The *note poplib: d0. module now supports POP over SSL. (Contributed by Hector Urtubia.) * The *note profile: d3. module can now profile C extension functions. (Contributed by Nick Bastin.) * The *note random: dc. module has a new method called ‘getrandbits(N)’ that returns a long integer `N' bits in length. The existing ‘randrange()’ method now uses ‘getrandbits()’ where appropriate, making generation of arbitrarily large random numbers more efficient. (Contributed by Raymond Hettinger.) * The regular expression language accepted by the *note re: dd. module was extended with simple conditional expressions, written as ‘(?(group)A|B)’. `group' is either a numeric group ID or a group name defined with ‘(?P...)’ earlier in the expression. If the specified group matched, the regular expression pattern `A' will be tested against the string; if the group didn’t match, the pattern `B' will be used instead. (Contributed by Gustavo Niemeyer.) * The *note re: dd. module is also no longer recursive, thanks to a massive amount of work by Gustavo Niemeyer. In a recursive regular expression engine, certain patterns result in a large amount of C stack space being consumed, and it was possible to overflow the stack. For example, if you matched a 30000-byte string of ‘a’ characters against the expression ‘(a|b)+’, one stack frame was consumed per character. Python 2.3 tried to check for stack overflow and raise a *note RuntimeError: 2ba. exception, but certain patterns could sidestep the checking and if you were unlucky Python could segfault. Python 2.4’s regular expression engine can match this pattern without problems. * The *note signal: ea. module now performs tighter error-checking on the parameters to the *note signal.signal(): a7d. function. For example, you can’t set a handler on the ‘SIGKILL’ signal; previous versions of Python would quietly accept this, but 2.4 will raise a *note RuntimeError: 2ba. exception. * Two new functions were added to the *note socket: ef. module. ‘socketpair()’ returns a pair of connected sockets and ‘getservbyport(port)’ looks up the service name for a given port number. (Contributed by Dave Cole and Barry Warsaw.) * The ‘sys.exitfunc()’ function has been deprecated. Code should be using the existing *note atexit: c. module, which correctly handles calling multiple exit functions. Eventually ‘sys.exitfunc()’ will become a purely internal interface, accessed only by *note atexit: c. * The *note tarfile: 101. module now generates GNU-format tar files by default. (Contributed by Lars Gustäbel.) * The *note threading: 109. module now has an elegantly simple way to support thread-local data. The module contains a ‘local’ class whose attribute values are local to different threads. import threading data = threading.local() data.number = 42 data.url = ('www.python.org', 80) Other threads can assign and retrieve their own values for the ‘number’ and ‘url’ attributes. You can subclass ‘local’ to initialize attributes or to add methods. (Contributed by Jim Fulton.) * The *note timeit: 10b. module now automatically disables periodic garbage collection during the timing loop. This change makes consecutive timings more comparable. (Contributed by Raymond Hettinger.) * The *note weakref: 128. module now supports a wider variety of objects including Python functions, class instances, sets, frozensets, deques, arrays, files, sockets, and regular expression pattern objects. (Contributed by Raymond Hettinger.) * The ‘xmlrpclib’ module now supports a multi-call extension for transmitting multiple XML-RPC calls in a single HTTP operation. (Contributed by Brian Quinlan.) * The ‘mpz’, ‘rotor’, and ‘xreadlines’ modules have been removed. * Menu: * cookielib:: * doctest: doctest<3>. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc3548.html  File: python.info, Node: cookielib, Next: doctest<3>, Up: New Improved and Deprecated Modules<3> 1.13.12.1 cookielib ................... The ‘cookielib’ library supports client-side handling for HTTP cookies, mirroring the ‘Cookie’ module’s server-side cookie support. Cookies are stored in cookie jars; the library transparently stores cookies offered by the web server in the cookie jar, and fetches the cookie from the jar when connecting to the server. As in web browsers, policy objects control whether cookies are accepted or not. In order to store cookies across sessions, two implementations of cookie jars are provided: one that stores cookies in the Netscape format so applications can use the Mozilla or Lynx cookie files, and one that stores cookies in the same format as the Perl libwww library. ‘urllib2’ has been changed to interact with ‘cookielib’: ‘HTTPCookieProcessor’ manages a cookie jar that is used when accessing URLs. This module was contributed by John J. Lee.  File: python.info, Node: doctest<3>, Prev: cookielib, Up: New Improved and Deprecated Modules<3> 1.13.12.2 doctest ................. The *note doctest: 67. module underwent considerable refactoring thanks to Edward Loper and Tim Peters. Testing can still be as simple as running *note doctest.testmod(): dd0, but the refactorings allow customizing the module’s operation in various ways The new ‘DocTestFinder’ class extracts the tests from a given object’s docstrings: def f (x, y): """>>> f(2,2) 4 >>> f(3,2) 6 """ return x*y finder = doctest.DocTestFinder() # Get list of DocTest instances tests = finder.find(f) The new ‘DocTestRunner’ class then runs individual tests and can produce a summary of the results: runner = doctest.DocTestRunner() for t in tests: tried, failed = runner.run(t) runner.summarize(verbose=1) The above example produces the following output: 1 items passed all tests: 2 tests in f 2 tests in 1 items. 2 passed and 0 failed. Test passed. ‘DocTestRunner’ uses an instance of the ‘OutputChecker’ class to compare the expected output with the actual output. This class takes a number of different flags that customize its behaviour; ambitious users can also write a completely new subclass of ‘OutputChecker’. The default output checker provides a number of handy features. For example, with the *note doctest.ELLIPSIS: dd1. option flag, an ellipsis (‘...’) in the expected output matches any substring, making it easier to accommodate outputs that vary in minor ways: def o (n): """>>> o(1) <__main__.C instance at 0x...> >>> """ Another special string, ‘’, matches a blank line: def p (n): """>>> p(1) >>> """ Another new capability is producing a diff-style display of the output by specifying the *note doctest.REPORT_UDIFF: dd2. (unified diffs), *note doctest.REPORT_CDIFF: dd3. (context diffs), or *note doctest.REPORT_NDIFF: dd4. (delta-style) option flags. For example: def g (n): """>>> g(4) here is a lengthy >>>""" L = 'here is a rather lengthy list of words'.split() for word in L[:n]: print word Running the above function’s tests with *note doctest.REPORT_UDIFF: dd2. specified, you get the following output: ********************************************************************** File "t.py", line 15, in g Failed example: g(4) Differences (unified diff with -expected +actual): @@ -2,3 +2,3 @@ is a -lengthy +rather **********************************************************************  File: python.info, Node: Build and C API Changes<11>, Next: Porting to Python 2 4, Prev: New Improved and Deprecated Modules<3>, Up: What’s New in Python 2 4 1.13.13 Build and C API Changes ------------------------------- Some of the changes to Python’s build process and to the C API are: * Three new convenience macros were added for common return values from extension functions: *note Py_RETURN_NONE: dd6, *note Py_RETURN_TRUE: dd7, and *note Py_RETURN_FALSE: dd8. (Contributed by Brett Cannon.) * Another new macro, ‘Py_CLEAR(obj)’, decreases the reference count of `obj' and sets `obj' to the null pointer. (Contributed by Jim Fulton.) * A new function, ‘PyTuple_Pack(N, obj1, obj2, ..., objN)’, constructs tuples from a variable length argument list of Python objects. (Contributed by Raymond Hettinger.) * A new function, ‘PyDict_Contains(d, k)’, implements fast dictionary lookups without masking exceptions raised during the look-up process. (Contributed by Raymond Hettinger.) * The ‘Py_IS_NAN(X)’ macro returns 1 if its float or double argument `X' is a NaN. (Contributed by Tim Peters.) * C code can avoid unnecessary locking by using the new *note PyEval_ThreadsInitialized(): dd9. function to tell if any thread operations have been performed. If this function returns false, no lock operations are needed. (Contributed by Nick Coghlan.) * A new function, *note PyArg_VaParseTupleAndKeywords(): dda, is the same as *note PyArg_ParseTupleAndKeywords(): 5ca. but takes a ‘va_list’ instead of a number of arguments. (Contributed by Greg Chapman.) * A new method flag, ‘METH_COEXISTS’, allows a function defined in slots to co-exist with a *note PyCFunction: ddb. having the same name. This can halve the access time for a method such as ‘set.__contains__()’. (Contributed by Raymond Hettinger.) * Python can now be built with additional profiling for the interpreter itself, intended as an aid to people developing the Python core. Providing ‘--enable-profiling’ to the ‘configure’ script will let you profile the interpreter with ‘gprof’, and providing the ‘--with-tsc’ switch enables profiling using the Pentium’s Time-Stamp-Counter register. Note that the ‘--with-tsc’ switch is slightly misnamed, because the profiling feature also works on the PowerPC platform, though that processor architecture doesn’t call that register “the TSC register”. (Contributed by Jeremy Hylton.) * The ‘tracebackobject’ type has been renamed to ‘PyTracebackObject’. * Menu: * Port-Specific Changes: Port-Specific Changes<2>.  File: python.info, Node: Port-Specific Changes<2>, Up: Build and C API Changes<11> 1.13.13.1 Port-Specific Changes ............................... * The Windows port now builds under MSVC++ 7.1 as well as version 6. (Contributed by Martin von Löwis.)  File: python.info, Node: Porting to Python 2 4, Next: Acknowledgements<4>, Prev: Build and C API Changes<11>, Up: What’s New in Python 2 4 1.13.14 Porting to Python 2.4 ----------------------------- This section lists previously described changes that may require changes to your code: * Left shifts and hexadecimal/octal constants that are too large no longer trigger a *note FutureWarning: 325. and return a value limited to 32 or 64 bits; instead they return a long integer. * Integer operations will no longer trigger an ‘OverflowWarning’. The ‘OverflowWarning’ warning will disappear in Python 2.5. * The *note zip(): c32. built-in function and ‘itertools.izip()’ now return an empty list instead of raising a *note TypeError: 192. exception if called with no arguments. * You can no longer compare the ‘date’ and *note datetime: 194. instances provided by the *note datetime: 31. module. Two instances of different classes will now always be unequal, and relative comparisons (‘<’, ‘>’) will raise a *note TypeError: 192. * ‘dircache.listdir()’ now passes exceptions to the caller instead of returning empty lists. * ‘LexicalHandler.startDTD()’ used to receive the public and system IDs in the wrong order. This has been corrected; applications relying on the wrong order need to be fixed. * *note fcntl.ioctl(): dde. now warns if the `mutate' argument is omitted and relevant. * The *note tarfile: 101. module now generates GNU-format tar files by default. * Encountering a failure while importing a module no longer leaves a partially-initialized module object in ‘sys.modules’. * *note None: 157. is now a constant; code that binds a new value to the name ‘None’ is now a syntax error. * The ‘signals.signal()’ function now raises a *note RuntimeError: 2ba. exception for certain illegal values; previously these errors would pass silently. For example, you can no longer set a handler on the ‘SIGKILL’ signal.  File: python.info, Node: Acknowledgements<4>, Prev: Porting to Python 2 4, Up: What’s New in Python 2 4 1.13.15 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Koray Can, Hye-Shik Chang, Michael Dyck, Raymond Hettinger, Brian Hurt, Hamish Lawson, Fredrik Lundh, Sean Reifschneider, Sadruddin Rejeb.  File: python.info, Node: What’s New in Python 2 3, Next: What’s New in Python 2 2, Prev: What’s New in Python 2 4, Up: What’s New in Python 1.14 What’s New in Python 2.3 ============================= Author: A.M. Kuchling This article explains the new features in Python 2.3. Python 2.3 was released on July 29, 2003. The main themes for Python 2.3 are polishing some of the features added in 2.2, adding various small but useful enhancements to the core language, and expanding the standard library. The new object model introduced in the previous version has benefited from 18 months of bugfixes and from optimization efforts that have improved the performance of new-style classes. A few new built-in functions have been added such as *note sum(): 1e5. and *note enumerate(): de3. The *note in: 7a3. operator can now be used for substring searches (e.g. ‘"ab" in "abc"’ returns *note True: 499.). Some of the many new library features include Boolean, set, heap, and date/time data types, the ability to import modules from ZIP-format archives, metadata support for the long-awaited Python catalog, an updated version of IDLE, and modules for logging messages, wrapping text, parsing CSV files, processing command-line options, using BerkeleyDB databases… the list of new and enhanced modules is lengthy. This article doesn’t attempt to provide a complete specification of the new features, but instead provides a convenient overview. For full details, you should refer to the documentation for Python 2.3, such as the Python Library Reference and the Python Reference Manual. If you want to understand the complete implementation and design rationale, refer to the PEP for a particular new feature. * Menu: * PEP 218; A Standard Set Datatype: PEP 218 A Standard Set Datatype. * PEP 255; Simple Generators: PEP 255 Simple Generators. * PEP 263; Source Code Encodings: PEP 263 Source Code Encodings. * PEP 273; Importing Modules from ZIP Archives: PEP 273 Importing Modules from ZIP Archives. * PEP 277; Unicode file name support for Windows NT: PEP 277 Unicode file name support for Windows NT. * PEP 278; Universal Newline Support: PEP 278 Universal Newline Support. * PEP 279; enumerate(): PEP 279 enumerate. * PEP 282; The logging Package: PEP 282 The logging Package. * PEP 285; A Boolean Type: PEP 285 A Boolean Type. * PEP 293; Codec Error Handling Callbacks: PEP 293 Codec Error Handling Callbacks. * PEP 301; Package Index and Metadata for Distutils: PEP 301 Package Index and Metadata for Distutils. * PEP 302; New Import Hooks: PEP 302 New Import Hooks. * PEP 305; Comma-separated Files: PEP 305 Comma-separated Files. * PEP 307; Pickle Enhancements: PEP 307 Pickle Enhancements. * Extended Slices:: * Other Language Changes: Other Language Changes<13>. * New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<4>. * Pymalloc; A Specialized Object Allocator: Pymalloc A Specialized Object Allocator. * Build and C API Changes: Build and C API Changes<12>. * Other Changes and Fixes: Other Changes and Fixes<2>. * Porting to Python 2.3: Porting to Python 2 3. * Acknowledgements: Acknowledgements<5>.  File: python.info, Node: PEP 218 A Standard Set Datatype, Next: PEP 255 Simple Generators, Up: What’s New in Python 2 3 1.14.1 PEP 218: A Standard Set Datatype --------------------------------------- The new ‘sets’ module contains an implementation of a set datatype. The ‘Set’ class is for mutable sets, sets that can have members added and removed. The ‘ImmutableSet’ class is for sets that can’t be modified, and instances of ‘ImmutableSet’ can therefore be used as dictionary keys. Sets are built on top of dictionaries, so the elements within a set must be hashable. Here’s a simple example: >>> import sets >>> S = sets.Set([1,2,3]) >>> S Set([1, 2, 3]) >>> 1 in S True >>> 0 in S False >>> S.add(5) >>> S.remove(3) >>> S Set([1, 2, 5]) >>> The union and intersection of sets can be computed with the ‘union()’ and ‘intersection()’ methods; an alternative notation uses the bitwise operators ‘&’ and ‘|’. Mutable sets also have in-place versions of these methods, ‘union_update()’ and ‘intersection_update()’. >>> S1 = sets.Set([1,2,3]) >>> S2 = sets.Set([4,5,6]) >>> S1.union(S2) Set([1, 2, 3, 4, 5, 6]) >>> S1 | S2 # Alternative notation Set([1, 2, 3, 4, 5, 6]) >>> S1.intersection(S2) Set([]) >>> S1 & S2 # Alternative notation Set([]) >>> S1.union_update(S2) >>> S1 Set([1, 2, 3, 4, 5, 6]) >>> It’s also possible to take the symmetric difference of two sets. This is the set of all elements in the union that aren’t in the intersection. Another way of putting it is that the symmetric difference contains all elements that are in exactly one set. Again, there’s an alternative notation (‘^’), and an in-place version with the ungainly name ‘symmetric_difference_update()’. >>> S1 = sets.Set([1,2,3,4]) >>> S2 = sets.Set([3,4,5,6]) >>> S1.symmetric_difference(S2) Set([1, 2, 5, 6]) >>> S1 ^ S2 Set([1, 2, 5, 6]) >>> There are also ‘issubset()’ and ‘issuperset()’ methods for checking whether one set is a subset or superset of another: >>> S1 = sets.Set([1,2,3]) >>> S2 = sets.Set([2,3]) >>> S2.issubset(S1) True >>> S1.issubset(S2) False >>> S1.issuperset(S2) True >>> See also ........ PEP 218(1) - Adding a Built-In Set Object Type PEP written by Greg V. Wilson. Implemented by Greg V. Wilson, Alex Martelli, and GvR. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0218  File: python.info, Node: PEP 255 Simple Generators, Next: PEP 263 Source Code Encodings, Prev: PEP 218 A Standard Set Datatype, Up: What’s New in Python 2 3 1.14.2 PEP 255: Simple Generators --------------------------------- In Python 2.2, generators were added as an optional feature, to be enabled by a ‘from __future__ import generators’ directive. In 2.3 generators no longer need to be specially enabled, and are now always present; this means that *note yield: 18f. is now always a keyword. The rest of this section is a copy of the description of generators from the “What’s New in Python 2.2” document; if you read it back when Python 2.2 came out, you can skip the rest of this section. You’re doubtless familiar with how function calls work in Python or C. When you call a function, it gets a private namespace where its local variables are created. When the function reaches a *note return: 190. statement, the local variables are destroyed and the resulting value is returned to the caller. A later call to the same function will get a fresh new set of local variables. But, what if the local variables weren’t thrown away on exiting a function? What if you could later resume the function where it left off? This is what generators provide; they can be thought of as resumable functions. Here’s the simplest example of a generator function: def generate_ints(N): for i in range(N): yield i A new keyword, *note yield: 18f, was introduced for generators. Any function containing a ‘yield’ statement is a generator function; this is detected by Python’s bytecode compiler which compiles the function specially as a result. When you call a generator function, it doesn’t return a single value; instead it returns a generator object that supports the iterator protocol. On executing the *note yield: 18f. statement, the generator outputs the value of ‘i’, similar to a *note return: 190. statement. The big difference between ‘yield’ and a ‘return’ statement is that on reaching a ‘yield’ the generator’s state of execution is suspended and local variables are preserved. On the next call to the generator’s ‘.next()’ method, the function will resume executing immediately after the ‘yield’ statement. (For complicated reasons, the ‘yield’ statement isn’t allowed inside the *note try: d72. block of a ‘try’…‘finally’ statement; read PEP 255(1) for a full explanation of the interaction between ‘yield’ and exceptions.) Here’s a sample usage of the ‘generate_ints()’ generator: >>> gen = generate_ints(3) >>> gen >>> gen.next() 0 >>> gen.next() 1 >>> gen.next() 2 >>> gen.next() Traceback (most recent call last): File "stdin", line 1, in ? File "stdin", line 2, in generate_ints StopIteration You could equally write ‘for i in generate_ints(5)’, or ‘a,b,c = generate_ints(3)’. Inside a generator function, the *note return: 190. statement can only be used without a value, and signals the end of the procession of values; afterwards the generator cannot return any further values. ‘return’ with a value, such as ‘return 5’, is a syntax error inside a generator function. The end of the generator’s results can also be indicated by raising *note StopIteration: 486. manually, or by just letting the flow of execution fall off the bottom of the function. You could achieve the effect of generators manually by writing your own class and storing all the local variables of the generator as instance variables. For example, returning a list of integers could be done by setting ‘self.count’ to 0, and having the *note next(): 682. method increment ‘self.count’ and return it. However, for a moderately complicated generator, writing a corresponding class would be much messier. ‘Lib/test/test_generators.py’ contains a number of more interesting examples. The simplest one implements an in-order traversal of a tree using generators recursively. # A recursive generator that generates Tree leaves in in-order. def inorder(t): if t: for x in inorder(t.left): yield x yield t.label for x in inorder(t.right): yield x Two other examples in ‘Lib/test/test_generators.py’ produce solutions for the N-Queens problem (placing $N$ queens on an $NxN$ chess board so that no queen threatens another) and the Knight’s Tour (a route that takes a knight to every square of an $NxN$ chessboard without visiting any square twice). The idea of generators comes from other programming languages, especially Icon (‘https://www.cs.arizona.edu/icon/’), where the idea of generators is central. In Icon, every expression and function call behaves like a generator. One example from “An Overview of the Icon Programming Language” at ‘https://www.cs.arizona.edu/icon/docs/ipd266.htm’ gives an idea of what this looks like: sentence := "Store it in the neighboring harbor" if (i := find("or", sentence)) > 5 then write(i) In Icon the ‘find()’ function returns the indexes at which the substring “or” is found: 3, 23, 33. In the *note if: de7. statement, ‘i’ is first assigned a value of 3, but 3 is less than 5, so the comparison fails, and Icon retries it with the second value of 23. 23 is greater than 5, so the comparison now succeeds, and the code prints the value 23 to the screen. Python doesn’t go nearly as far as Icon in adopting generators as a central concept. Generators are considered part of the core Python language, but learning or using them isn’t compulsory; if they don’t solve any problems that you have, feel free to ignore them. One novel feature of Python’s interface as compared to Icon’s is that a generator’s state is represented as a concrete object (the iterator) that can be passed around to other functions or stored in a data structure. See also ........ PEP 255(2) - Simple Generators Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland. Implemented mostly by Neil Schemenauer and Tim Peters, with other fixes from the Python Labs crew. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0255 (2) https://www.python.org/dev/peps/pep-0255  File: python.info, Node: PEP 263 Source Code Encodings, Next: PEP 273 Importing Modules from ZIP Archives, Prev: PEP 255 Simple Generators, Up: What’s New in Python 2 3 1.14.3 PEP 263: Source Code Encodings ------------------------------------- Python source files can now be declared as being in different character set encodings. Encodings are declared by including a specially formatted comment in the first or second line of the source file. For example, a UTF-8 file can be declared with: #!/usr/bin/env python # -*- coding: UTF-8 -*- Without such an encoding declaration, the default encoding used is 7-bit ASCII. Executing or importing modules that contain string literals with 8-bit characters and have no encoding declaration will result in a *note DeprecationWarning: 278. being signalled by Python 2.3; in 2.4 this will be a syntax error. The encoding declaration only affects Unicode string literals, which will be converted to Unicode using the specified encoding. Note that Python identifiers are still restricted to ASCII characters, so you can’t have variable names that use characters outside of the usual alphanumerics. See also ........ PEP 263(1) - Defining Python Source Code Encodings Written by Marc-André Lemburg and Martin von Löwis; implemented by Suzuki Hisao and Martin von Löwis. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0263  File: python.info, Node: PEP 273 Importing Modules from ZIP Archives, Next: PEP 277 Unicode file name support for Windows NT, Prev: PEP 263 Source Code Encodings, Up: What’s New in Python 2 3 1.14.4 PEP 273: Importing Modules from ZIP Archives --------------------------------------------------- The new *note zipimport: 143. module adds support for importing modules from a ZIP-format archive. You don’t need to import the module explicitly; it will be automatically imported if a ZIP archive’s filename is added to ‘sys.path’. For example: amk@nyman:~/src/python$ unzip -l /tmp/example.zip Archive: /tmp/example.zip Length Date Time Name -------- ---- ---- ---- 8467 11-26-02 22:30 jwzthreading.py -------- ------- 8467 1 file amk@nyman:~/src/python$ ./python Python 2.3 (#1, Aug 1 2003, 19:54:32) >>> import sys >>> sys.path.insert(0, '/tmp/example.zip') # Add .zip file to front of path >>> import jwzthreading >>> jwzthreading.__file__ '/tmp/example.zip/jwzthreading.py' >>> An entry in ‘sys.path’ can now be the filename of a ZIP archive. The ZIP archive can contain any kind of files, but only files named ‘*.py’, ‘*.pyc’, or ‘*.pyo’ can be imported. If an archive only contains ‘*.py’ files, Python will not attempt to modify the archive by adding the corresponding ‘*.pyc’ file, meaning that if a ZIP archive doesn’t contain ‘*.pyc’ files, importing may be rather slow. A path within the archive can also be specified to only import from a subdirectory; for example, the path ‘/tmp/example.zip/lib/’ would only import from the ‘lib/’ subdirectory within the archive. See also ........ PEP 273(1) - Import Modules from Zip Archives Written by James C. Ahlstrom, who also provided an implementation. Python 2.3 follows the specification in PEP 273(2), but uses an implementation written by Just van Rossum that uses the import hooks described in PEP 302(3). See section *note PEP 302; New Import Hooks: deb. for a description of the new import hooks. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0273 (2) https://www.python.org/dev/peps/pep-0273 (3) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: PEP 277 Unicode file name support for Windows NT, Next: PEP 278 Universal Newline Support, Prev: PEP 273 Importing Modules from ZIP Archives, Up: What’s New in Python 2 3 1.14.5 PEP 277: Unicode file name support for Windows NT -------------------------------------------------------- On Windows NT, 2000, and XP, the system stores file names as Unicode strings. Traditionally, Python has represented file names as byte strings, which is inadequate because it renders some file names inaccessible. Python now allows using arbitrary Unicode strings (within the limitations of the file system) for all functions that expect file names, most notably the *note open(): 4f0. built-in function. If a Unicode string is passed to *note os.listdir(): a41, Python now returns a list of Unicode strings. A new function, ‘os.getcwdu()’, returns the current directory as a Unicode string. Byte strings still work as file names, and on Windows Python will transparently convert them to Unicode using the ‘mbcs’ encoding. Other systems also allow Unicode strings as file names but convert them to byte strings before passing them to the system, which can cause a *note UnicodeError: c3b. to be raised. Applications can test whether arbitrary Unicode strings are supported as file names by checking *note os.path.supports_unicode_filenames: ded, a Boolean value. Under MacOS, *note os.listdir(): a41. may now return Unicode filenames. See also ........ PEP 277(1) - Unicode file name support for Windows NT Written by Neil Hodgson; implemented by Neil Hodgson, Martin von Löwis, and Mark Hammond. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0277  File: python.info, Node: PEP 278 Universal Newline Support, Next: PEP 279 enumerate, Prev: PEP 277 Unicode file name support for Windows NT, Up: What’s New in Python 2 3 1.14.6 PEP 278: Universal Newline Support ----------------------------------------- The three major operating systems used today are Microsoft Windows, Apple’s Macintosh OS, and the various Unix derivatives. A minor irritation of cross-platform work is that these three platforms all use different characters to mark the ends of lines in text files. Unix uses the linefeed (ASCII character 10), MacOS uses the carriage return (ASCII character 13), and Windows uses a two-character sequence of a carriage return plus a newline. Python’s file objects can now support end of line conventions other than the one followed by the platform on which Python is running. Opening a file with the mode ‘'U'’ or ‘'rU'’ will open a file for reading in *note universal newlines: 5f4. mode. All three line ending conventions will be translated to a ‘'\n'’ in the strings returned by the various file methods such as ‘read()’ and *note readline(): de. Universal newline support is also used when importing modules and when executing a file with the ‘execfile()’ function. This means that Python modules can be shared between all three operating systems without needing to convert the line-endings. This feature can be disabled when compiling Python by specifying the ‘--without-universal-newlines’ switch when running Python’s ‘configure’ script. See also ........ PEP 278(1) - Universal Newline Support Written and implemented by Jack Jansen. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0278  File: python.info, Node: PEP 279 enumerate, Next: PEP 282 The logging Package, Prev: PEP 278 Universal Newline Support, Up: What’s New in Python 2 3 1.14.7 PEP 279: enumerate() --------------------------- A new built-in function, *note enumerate(): de3, will make certain loops a bit clearer. ‘enumerate(thing)’, where `thing' is either an iterator or a sequence, returns an iterator that will return ‘(0, thing[0])’, ‘(1, thing[1])’, ‘(2, thing[2])’, and so forth. A common idiom to change every element of a list looks like this: for i in range(len(L)): item = L[i] # ... compute some result based on item ... L[i] = result This can be rewritten using *note enumerate(): de3. as: for i, item in enumerate(L): # ... compute some result based on item ... L[i] = result See also ........ PEP 279(1) - The enumerate() built-in function Written and implemented by Raymond D. Hettinger. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0279  File: python.info, Node: PEP 282 The logging Package, Next: PEP 285 A Boolean Type, Prev: PEP 279 enumerate, Up: What’s New in Python 2 3 1.14.8 PEP 282: The logging Package ----------------------------------- A standard package for writing logs, *note logging: aa, has been added to Python 2.3. It provides a powerful and flexible mechanism for generating logging output which can then be filtered and processed in various ways. A configuration file written in a standard format can be used to control the logging behavior of a program. Python includes handlers that will write log records to standard error or to a file or socket, send them to the system log, or even e-mail them to a particular address; of course, it’s also possible to write your own handler classes. The ‘Logger’ class is the primary class. Most application code will deal with one or more ‘Logger’ objects, each one used by a particular subsystem of the application. Each ‘Logger’ is identified by a name, and names are organized into a hierarchy using ‘.’ as the component separator. For example, you might have ‘Logger’ instances named ‘server’, ‘server.auth’ and ‘server.network’. The latter two instances are below ‘server’ in the hierarchy. This means that if you turn up the verbosity for ‘server’ or direct ‘server’ messages to a different handler, the changes will also apply to records logged to ‘server.auth’ and ‘server.network’. There’s also a root ‘Logger’ that’s the parent of all other loggers. For simple uses, the *note logging: aa. package contains some convenience functions that always use the root log: import logging logging.debug('Debugging information') logging.info('Informational message') logging.warning('Warning:config file %s not found', 'server.conf') logging.error('Error occurred') logging.critical('Critical error -- shutting down') This produces the following output: WARNING:root:Warning:config file server.conf not found ERROR:root:Error occurred CRITICAL:root:Critical error -- shutting down In the default configuration, informational and debugging messages are suppressed and the output is sent to standard error. You can enable the display of informational and debugging messages by calling the ‘setLevel()’ method on the root logger. Notice the ‘warning()’ call’s use of string formatting operators; all of the functions for logging messages take the arguments ‘(msg, arg1, arg2, ...)’ and log the string resulting from ‘msg % (arg1, arg2, ...)’. There’s also an ‘exception()’ function that records the most recent traceback. Any of the other functions will also record the traceback if you specify a true value for the keyword argument `exc_info'. def f(): try: 1/0 except: logging.exception('Problem recorded') f() This produces the following output: ERROR:root:Problem recorded Traceback (most recent call last): File "t.py", line 6, in f 1/0 ZeroDivisionError: integer division or modulo by zero Slightly more advanced programs will use a logger other than the root logger. The ‘getLogger(name)’ function is used to get a particular log, creating it if it doesn’t exist yet. ‘getLogger(None)’ returns the root logger. log = logging.getLogger('server') ... log.info('Listening on port %i', port) ... log.critical('Disk full') ... Log records are usually propagated up the hierarchy, so a message logged to ‘server.auth’ is also seen by ‘server’ and ‘root’, but a ‘Logger’ can prevent this by setting its ‘propagate’ attribute to *note False: 388. There are more classes provided by the *note logging: aa. package that can be customized. When a ‘Logger’ instance is told to log a message, it creates a ‘LogRecord’ instance that is sent to any number of different ‘Handler’ instances. Loggers and handlers can also have an attached list of filters, and each filter can cause the ‘LogRecord’ to be ignored or can modify the record before passing it along. When they’re finally output, ‘LogRecord’ instances are converted to text by a ‘Formatter’ class. All of these classes can be replaced by your own specially-written classes. With all of these features the *note logging: aa. package should provide enough flexibility for even the most complicated applications. This is only an incomplete overview of its features, so please see the package’s reference documentation for all of the details. Reading PEP 282(1) will also be helpful. See also ........ PEP 282(2) - A Logging System Written by Vinay Sajip and Trent Mick; implemented by Vinay Sajip. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0282 (2) https://www.python.org/dev/peps/pep-0282  File: python.info, Node: PEP 285 A Boolean Type, Next: PEP 293 Codec Error Handling Callbacks, Prev: PEP 282 The logging Package, Up: What’s New in Python 2 3 1.14.9 PEP 285: A Boolean Type ------------------------------ A Boolean type was added to Python 2.3. Two new constants were added to the ‘__builtin__’ module, *note True: 499. and *note False: 388. (*note True: 499. and *note False: 388. constants were added to the built-ins in Python 2.2.1, but the 2.2.1 versions are simply set to integer values of 1 and 0 and aren’t a different type.) The type object for this new type is named *note bool: 183.; the constructor for it takes any Python value and converts it to *note True: 499. or *note False: 388. >>> bool(1) True >>> bool(0) False >>> bool([]) False >>> bool( (1,) ) True Most of the standard library modules and built-in functions have been changed to return Booleans. >>> obj = [] >>> hasattr(obj, 'append') True >>> isinstance(obj, list) True >>> isinstance(obj, tuple) False Python’s Booleans were added with the primary goal of making code clearer. For example, if you’re reading a function and encounter the statement ‘return 1’, you might wonder whether the ‘1’ represents a Boolean truth value, an index, or a coefficient that multiplies some other quantity. If the statement is ‘return True’, however, the meaning of the return value is quite clear. Python’s Booleans were `not' added for the sake of strict type-checking. A very strict language such as Pascal would also prevent you performing arithmetic with Booleans, and would require that the expression in an *note if: de7. statement always evaluate to a Boolean result. Python is not this strict and never will be, as PEP 285(1) explicitly says. This means you can still use any expression in an ‘if’ statement, even ones that evaluate to a list or tuple or some random object. The Boolean type is a subclass of the *note int: 184. class so that arithmetic using a Boolean still works. >>> True + 1 2 >>> False + 1 1 >>> False * 75 0 >>> True * 75 75 To sum up *note True: 499. and *note False: 388. in a sentence: they’re alternative ways to spell the integer values 1 and 0, with the single difference that *note str(): 330. and *note repr(): 7cc. return the strings ‘'True'’ and ‘'False'’ instead of ‘'1'’ and ‘'0'’. See also ........ PEP 285(2) - Adding a bool type Written and implemented by GvR. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0285 (2) https://www.python.org/dev/peps/pep-0285  File: python.info, Node: PEP 293 Codec Error Handling Callbacks, Next: PEP 301 Package Index and Metadata for Distutils, Prev: PEP 285 A Boolean Type, Up: What’s New in Python 2 3 1.14.10 PEP 293: Codec Error Handling Callbacks ----------------------------------------------- When encoding a Unicode string into a byte string, unencodable characters may be encountered. So far, Python has allowed specifying the error processing as either “strict” (raising *note UnicodeError: c3b.), “ignore” (skipping the character), or “replace” (using a question mark in the output string), with “strict” being the default behavior. It may be desirable to specify alternative processing of such errors, such as inserting an XML character reference or HTML entity reference into the converted string. Python now has a flexible framework to add different processing strategies. New error handlers can be added with *note codecs.register_error(): df5, and codecs then can access the error handler with *note codecs.lookup_error(): df6. An equivalent C API has been added for codecs written in C. The error handler gets the necessary state information such as the string being converted, the position in the string where the error was detected, and the target encoding. The handler can then either raise an exception or return a replacement string. Two additional error handlers have been implemented using this framework: “backslashreplace” uses Python backslash quoting to represent unencodable characters and “xmlcharrefreplace” emits XML character references. See also ........ PEP 293(1) - Codec Error Handling Callbacks Written and implemented by Walter Dörwald. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0293  File: python.info, Node: PEP 301 Package Index and Metadata for Distutils, Next: PEP 302 New Import Hooks, Prev: PEP 293 Codec Error Handling Callbacks, Up: What’s New in Python 2 3 1.14.11 PEP 301: Package Index and Metadata for Distutils --------------------------------------------------------- Support for the long-requested Python catalog makes its first appearance in 2.3. The heart of the catalog is the new Distutils ‘register’ command. Running ‘python setup.py register’ will collect the metadata describing a package, such as its name, version, maintainer, description, &c., and send it to a central catalog server. The resulting catalog is available from ‘https://pypi.org’. To make the catalog a bit more useful, a new optional `classifiers' keyword argument has been added to the Distutils ‘setup()’ function. A list of Trove(1)-style strings can be supplied to help classify the software. Here’s an example ‘setup.py’ with classifiers, written to be compatible with older versions of the Distutils: from distutils import core kw = {'name': "Quixote", 'version': "0.5.1", 'description': "A highly Pythonic Web application framework", # ... } if (hasattr(core, 'setup_keywords') and 'classifiers' in core.setup_keywords): kw['classifiers'] = \ ['Topic :: Internet :: WWW/HTTP :: Dynamic Content', 'Environment :: No Input/Output (Daemon)', 'Intended Audience :: Developers'], core.setup(**kw) The full list of classifiers can be obtained by running ‘python setup.py register --list-classifiers’. See also ........ PEP 301(2) - Package Index and Metadata for Distutils Written and implemented by Richard Jones. ---------- Footnotes ---------- (1) http://catb.org/~esr/trove/ (2) https://www.python.org/dev/peps/pep-0301  File: python.info, Node: PEP 302 New Import Hooks, Next: PEP 305 Comma-separated Files, Prev: PEP 301 Package Index and Metadata for Distutils, Up: What’s New in Python 2 3 1.14.12 PEP 302: New Import Hooks --------------------------------- While it’s been possible to write custom import hooks ever since the ‘ihooks’ module was introduced in Python 1.3, no one has ever been really happy with it because writing new import hooks is difficult and messy. There have been various proposed alternatives such as the ‘imputil’ and ‘iu’ modules, but none of them has ever gained much acceptance, and none of them were easily usable from C code. PEP 302(1) borrows ideas from its predecessors, especially from Gordon McMillan’s ‘iu’ module. Three new items are added to the *note sys: fd. module: * ‘sys.path_hooks’ is a list of callable objects; most often they’ll be classes. Each callable takes a string containing a path and either returns an importer object that will handle imports from this path or raises an *note ImportError: 334. exception if it can’t handle this path. * ‘sys.path_importer_cache’ caches importer objects for each path, so ‘sys.path_hooks’ will only need to be traversed once for each path. * ‘sys.meta_path’ is a list of importer objects that will be traversed before ‘sys.path’ is checked. This list is initially empty, but user code can add objects to it. Additional built-in and frozen modules can be imported by an object added to this list. Importer objects must have a single method, ‘find_module(fullname, path=None)’. `fullname' will be a module or package name, e.g. ‘string’ or ‘distutils.core’. ‘find_module()’ must return a loader object that has a single method, ‘load_module(fullname)’, that creates and returns the corresponding module object. Pseudo-code for Python’s new import logic, therefore, looks something like this (simplified a bit; see PEP 302(2) for the full details): for mp in sys.meta_path: loader = mp(fullname) if loader is not None: = loader.load_module(fullname) for path in sys.path: for hook in sys.path_hooks: try: importer = hook(path) except ImportError: # ImportError, so try the other path hooks pass else: loader = importer.find_module(fullname) = loader.load_module(fullname) # Not found! raise ImportError See also ........ PEP 302(3) - New Import Hooks Written by Just van Rossum and Paul Moore. Implemented by Just van Rossum. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0302 (2) https://www.python.org/dev/peps/pep-0302 (3) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: PEP 305 Comma-separated Files, Next: PEP 307 Pickle Enhancements, Prev: PEP 302 New Import Hooks, Up: What’s New in Python 2 3 1.14.13 PEP 305: Comma-separated Files -------------------------------------- Comma-separated files are a format frequently used for exporting data from databases and spreadsheets. Python 2.3 adds a parser for comma-separated files. Comma-separated format is deceptively simple at first glance: Costs,150,200,3.95 Read a line and call ‘line.split(',')’: what could be simpler? But toss in string data that can contain commas, and things get more complicated: "Costs",150,200,3.95,"Includes taxes, shipping, and sundry items" A big ugly regular expression can parse this, but using the new *note csv: 2a. package is much simpler: import csv input = open('datafile', 'rb') reader = csv.reader(input) for line in reader: print line The ‘reader()’ function takes a number of different options. The field separator isn’t limited to the comma and can be changed to any character, and so can the quoting and line-ending characters. Different dialects of comma-separated files can be defined and registered; currently there are two dialects, both used by Microsoft Excel. A separate *note csv.writer: dfc. class will generate comma-separated files from a succession of tuples or lists, quoting strings that contain the delimiter. See also ........ PEP 305(1) - CSV File API Written and implemented by Kevin Altis, Dave Cole, Andrew McNamara, Skip Montanaro, Cliff Wells. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0305  File: python.info, Node: PEP 307 Pickle Enhancements, Next: Extended Slices, Prev: PEP 305 Comma-separated Files, Up: What’s New in Python 2 3 1.14.14 PEP 307: Pickle Enhancements ------------------------------------ The *note pickle: ca. and ‘cPickle’ modules received some attention during the 2.3 development cycle. In 2.2, new-style classes could be pickled without difficulty, but they weren’t pickled very compactly; PEP 307(1) quotes a trivial example where a new-style class results in a pickled string three times longer than that for a classic class. The solution was to invent a new pickle protocol. The *note pickle.dumps(): dff. function has supported a text-or-binary flag for a long time. In 2.3, this flag is redefined from a Boolean to an integer: 0 is the old text-mode pickle format, 1 is the old binary format, and now 2 is a new 2.3-specific format. A new constant, *note pickle.HIGHEST_PROTOCOL: e00, can be used to select the fanciest protocol available. Unpickling is no longer considered a safe operation. 2.2’s *note pickle: ca. provided hooks for trying to prevent unsafe classes from being unpickled (specifically, a ‘__safe_for_unpickling__’ attribute), but none of this code was ever audited and therefore it’s all been ripped out in 2.3. You should not unpickle untrusted data in any version of Python. To reduce the pickling overhead for new-style classes, a new interface for customizing pickling was added using three special methods: *note __getstate__(): e01, *note __setstate__(): 19c, and *note __getnewargs__(): 6ae. Consult PEP 307(2) for the full semantics of these methods. As a way to compress pickles yet further, it’s now possible to use integer codes instead of long strings to identify pickled classes. The Python Software Foundation will maintain a list of standardized codes; there’s also a range of codes for private use. Currently no codes have been specified. See also ........ PEP 307(3) - Extensions to the pickle protocol Written and implemented by Guido van Rossum and Tim Peters. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0307 (2) https://www.python.org/dev/peps/pep-0307 (3) https://www.python.org/dev/peps/pep-0307  File: python.info, Node: Extended Slices, Next: Other Language Changes<13>, Prev: PEP 307 Pickle Enhancements, Up: What’s New in Python 2 3 1.14.15 Extended Slices ----------------------- Ever since Python 1.4, the slicing syntax has supported an optional third “step” or “stride” argument. For example, these are all legal Python syntax: ‘L[1:10:2]’, ‘L[:-1:1]’, ‘L[::-1]’. This was added to Python at the request of the developers of Numerical Python, which uses the third argument extensively. However, Python’s built-in list, tuple, and string sequence types have never supported this feature, raising a *note TypeError: 192. if you tried it. Michael Hudson contributed a patch to fix this shortcoming. For example, you can now easily extract the elements of a list that have even indexes: >>> L = range(10) >>> L[::2] [0, 2, 4, 6, 8] Negative values also work to make a copy of the same list in reverse order: >>> L[::-1] [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] This also works for tuples, arrays, and strings: >>> s='abcd' >>> s[::2] 'ac' >>> s[::-1] 'dcba' If you have a mutable sequence such as a list or an array you can assign to or delete an extended slice, but there are some differences between assignment to extended and regular slices. Assignment to a regular slice can be used to change the length of the sequence: >>> a = range(3) >>> a [0, 1, 2] >>> a[1:3] = [4, 5, 6] >>> a [0, 4, 5, 6] Extended slices aren’t this flexible. When assigning to an extended slice, the list on the right hand side of the statement must contain the same number of items as the slice it is replacing: >>> a = range(4) >>> a [0, 1, 2, 3] >>> a[::2] [0, 2] >>> a[::2] = [0, -1] >>> a [0, 1, -1, 3] >>> a[::2] = [0,1,2] Traceback (most recent call last): File "", line 1, in ? ValueError: attempt to assign sequence of size 3 to extended slice of size 2 Deletion is more straightforward: >>> a = range(4) >>> a [0, 1, 2, 3] >>> a[::2] [0, 2] >>> del a[::2] >>> a [1, 3] One can also now pass slice objects to the *note __getitem__(): 27c. methods of the built-in sequences: >>> range(10).__getitem__(slice(0, 5, 2)) [0, 2, 4] Or use slice objects directly in subscripts: >>> range(10)[slice(0, 5, 2)] [0, 2, 4] To simplify implementing sequences that support extended slicing, slice objects now have a method ‘indices(length)’ which, given the length of a sequence, returns a ‘(start, stop, step)’ tuple that can be passed directly to *note range(): 9be. ‘indices()’ handles omitted and out-of-bounds indices in a manner consistent with regular slices (and this innocuous phrase hides a welter of confusing details!). The method is intended to be used like this: class FakeSeq: ... def calc_item(self, i): ... def __getitem__(self, item): if isinstance(item, slice): indices = item.indices(len(self)) return FakeSeq([self.calc_item(i) for i in range(*indices)]) else: return self.calc_item(i) From this example you can also see that the built-in *note slice: e04. object is now the type object for the slice type, and is no longer a function. This is consistent with Python 2.2, where *note int: 184, *note str: 330, etc., underwent the same change.  File: python.info, Node: Other Language Changes<13>, Next: New Improved and Deprecated Modules<4>, Prev: Extended Slices, Up: What’s New in Python 2 3 1.14.16 Other Language Changes ------------------------------ Here are all of the changes that Python 2.3 makes to the core Python language. * The *note yield: 18f. statement is now always a keyword, as described in section *note PEP 255; Simple Generators: de6. of this document. * A new built-in function *note enumerate(): de3. was added, as described in section *note PEP 279; enumerate(): df0. of this document. * Two new constants, *note True: 499. and *note False: 388. were added along with the built-in *note bool: 183. type, as described in section *note PEP 285; A Boolean Type: df3. of this document. * The *note int(): 184. type constructor will now return a long integer instead of raising an *note OverflowError: 960. when a string or floating-point number is too large to fit into an integer. This can lead to the paradoxical result that ‘isinstance(int(expression), int)’ is false, but that seems unlikely to cause problems in practice. * Built-in types now support the extended slicing syntax, as described in section *note Extended Slices: e03. of this document. * A new built-in function, ‘sum(iterable, start=0)’, adds up the numeric items in the iterable object and returns their sum. *note sum(): 1e5. only accepts numbers, meaning that you can’t use it to concatenate a bunch of strings. (Contributed by Alex Martelli.) * ‘list.insert(pos, value)’ used to insert `value' at the front of the list when `pos' was negative. The behaviour has now been changed to be consistent with slice indexing, so when `pos' is -1 the value will be inserted before the last element, and so forth. * ‘list.index(value)’, which searches for `value' within the list and returns its index, now takes optional `start' and `stop' arguments to limit the search to only part of the list. * Dictionaries have a new method, ‘pop(key[, *default*])’, that returns the value corresponding to `key' and removes that key/value pair from the dictionary. If the requested key isn’t present in the dictionary, `default' is returned if it’s specified and *note KeyError: 2c7. raised if it isn’t. >>> d = {1:2} >>> d {1: 2} >>> d.pop(4) Traceback (most recent call last): File "stdin", line 1, in ? KeyError: 4 >>> d.pop(1) 2 >>> d.pop(1) Traceback (most recent call last): File "stdin", line 1, in ? KeyError: 'pop(): dictionary is empty' >>> d {} >>> There’s also a new class method, ‘dict.fromkeys(iterable, value)’, that creates a dictionary with keys taken from the supplied iterator `iterable' and all values set to `value', defaulting to ‘None’. (Patches contributed by Raymond Hettinger.) Also, the *note dict(): 1b8. constructor now accepts keyword arguments to simplify creating small dictionaries: >>> dict(red=1, blue=2, green=3, black=4) {'blue': 2, 'black': 4, 'green': 3, 'red': 1} (Contributed by Just van Rossum.) * The *note assert: e06. statement no longer checks the ‘__debug__’ flag, so you can no longer disable assertions by assigning to ‘__debug__’. Running Python with the *note -O: 68b. switch will still generate code that doesn’t execute any assertions. * Most type objects are now callable, so you can use them to create new objects such as functions, classes, and modules. (This means that the ‘new’ module can be deprecated in a future Python version, because you can now use the type objects available in the *note types: 118. module.) For example, you can create a new module object with the following code: >>> import types >>> m = types.ModuleType('abc','docstring') >>> m >>> m.__doc__ 'docstring' * A new warning, *note PendingDeprecationWarning: 279. was added to indicate features which are in the process of being deprecated. The warning will `not' be printed by default. To check for use of features that will be deprecated in the future, supply *note -Walways;;PendingDeprecationWarning;;: 417. on the command line or use *note warnings.filterwarnings(): e07. * The process of deprecating string-based exceptions, as in ‘raise "Error occurred"’, has begun. Raising a string will now trigger *note PendingDeprecationWarning: 279. * Using ‘None’ as a variable name will now result in a *note SyntaxWarning: 191. warning. In a future version of Python, ‘None’ may finally become a keyword. * The ‘xreadlines()’ method of file objects, introduced in Python 2.1, is no longer necessary because files now behave as their own iterator. ‘xreadlines()’ was originally introduced as a faster way to loop over all the lines in a file, but now you can simply write ‘for line in file_obj’. File objects also have a new read-only ‘encoding’ attribute that gives the encoding used by the file; Unicode strings written to the file will be automatically converted to bytes using the given encoding. * The method resolution order used by new-style classes has changed, though you’ll only notice the difference if you have a really complicated inheritance hierarchy. Classic classes are unaffected by this change. Python 2.2 originally used a topological sort of a class’s ancestors, but 2.3 now uses the C3 algorithm as described in the paper "A Monotonic Superclass Linearization for Dylan"(1). To understand the motivation for this change, read Michele Simionato’s article "Python 2.3 Method Resolution Order"(2), or read the thread on python-dev starting with the message at ‘https://mail.python.org/pipermail/python-dev/2002-October/029035.html’. Samuele Pedroni first pointed out the problem and also implemented the fix by coding the C3 algorithm. * Python runs multithreaded programs by switching between threads after executing N bytecodes. The default value for N has been increased from 10 to 100 bytecodes, speeding up single-threaded applications by reducing the switching overhead. Some multithreaded applications may suffer slower response time, but that’s easily fixed by setting the limit back to a lower number using ‘sys.setcheckinterval(N)’. The limit can be retrieved with the new *note sys.getcheckinterval(): e08. function. * One minor but far-reaching change is that the names of extension types defined by the modules included with Python now contain the module and a ‘'.'’ in front of the type name. For example, in Python 2.2, if you created a socket and printed its ‘__class__’, you’d get this output: >>> s = socket.socket() >>> s.__class__ In 2.3, you get this: >>> s.__class__ * One of the noted incompatibilities between old- and new-style classes has been removed: you can now assign to the *note __name__: c67. and *note __bases__: e09. attributes of new-style classes. There are some restrictions on what can be assigned to *note __bases__: e09. along the lines of those relating to assigning to an instance’s *note __class__: e0a. attribute. * Menu: * String Changes:: * Optimizations: Optimizations<12>. ---------- Footnotes ---------- (1) http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.19.3910 (2) http://www.phyast.pitt.edu/~micheles/mro.html  File: python.info, Node: String Changes, Next: Optimizations<12>, Up: Other Language Changes<13> 1.14.16.1 String Changes ........................ * The *note in: 7a3. operator now works differently for strings. Previously, when evaluating ‘X in Y’ where `X' and `Y' are strings, `X' could only be a single character. That’s now changed; `X' can be a string of any length, and ‘X in Y’ will return *note True: 499. if `X' is a substring of `Y'. If `X' is the empty string, the result is always *note True: 499. >>> 'ab' in 'abcd' True >>> 'ad' in 'abcd' False >>> '' in 'abcd' True Note that this doesn’t tell you where the substring starts; if you need that information, use the ‘find()’ string method. * The ‘strip()’, ‘lstrip()’, and ‘rstrip()’ string methods now have an optional argument for specifying the characters to strip. The default is still to remove all whitespace characters: >>> ' abc '.strip() 'abc' >>> '><><><>'.strip('<>') 'abc' >>> '><><><>\n'.strip('<>') 'abc<><><>\n' >>> u'\u4000\u4001abc\u4000'.strip(u'\u4000') u'\u4001abc' >>> (Suggested by Simon Brunning and implemented by Walter Dörwald.) * The ‘startswith()’ and ‘endswith()’ string methods now accept negative numbers for the `start' and `end' parameters. * Another new string method is ‘zfill()’, originally a function in the *note string: f6. module. ‘zfill()’ pads a numeric string with zeros on the left until it’s the specified width. Note that the ‘%’ operator is still more flexible and powerful than ‘zfill()’. >>> '45'.zfill(4) '0045' >>> '12345'.zfill(4) '12345' >>> 'goofy'.zfill(6) '0goofy' (Contributed by Walter Dörwald.) * A new type object, ‘basestring’, has been added. Both 8-bit strings and Unicode strings inherit from this type, so ‘isinstance(obj, basestring)’ will return *note True: 499. for either kind of string. It’s a completely abstract type, so you can’t create ‘basestring’ instances. * Interned strings are no longer immortal and will now be garbage-collected in the usual way when the only reference to them is from the internal dictionary of interned strings. (Implemented by Oren Tirosh.)  File: python.info, Node: Optimizations<12>, Prev: String Changes, Up: Other Language Changes<13> 1.14.16.2 Optimizations ....................... * The creation of new-style class instances has been made much faster; they’re now faster than classic classes! * The ‘sort()’ method of list objects has been extensively rewritten by Tim Peters, and the implementation is significantly faster. * Multiplication of large long integers is now much faster thanks to an implementation of Karatsuba multiplication, an algorithm that scales better than the O(n*n) required for the grade-school multiplication algorithm. (Original patch by Christopher A. Craig, and significantly reworked by Tim Peters.) * The ‘SET_LINENO’ opcode is now gone. This may provide a small speed increase, depending on your compiler’s idiosyncrasies. See section *note Other Changes and Fixes: e0d. for a longer explanation. (Removed by Michael Hudson.) * ‘xrange()’ objects now have their own iterator, making ‘for i in xrange(n)’ slightly faster than ‘for i in range(n)’. (Patch by Raymond Hettinger.) * A number of small rearrangements have been made in various hotspots to improve performance, such as inlining a function or removing some code. (Implemented mostly by GvR, but lots of people have contributed single changes.) The net result of the 2.3 optimizations is that Python 2.3 runs the pystone benchmark around 25% faster than Python 2.2.  File: python.info, Node: New Improved and Deprecated Modules<4>, Next: Pymalloc A Specialized Object Allocator, Prev: Other Language Changes<13>, Up: What’s New in Python 2 3 1.14.17 New, Improved, and Deprecated Modules --------------------------------------------- As usual, Python’s standard library received a number of enhancements and bug fixes. Here’s a partial list of the most notable changes, sorted alphabetically by module name. Consult the ‘Misc/NEWS’ file in the source tree for a more complete list of changes, or look through the CVS logs for all the details. * The *note array: 7. module now supports arrays of Unicode characters using the ‘'u'’ format character. Arrays also now support using the ‘+=’ assignment operator to add another array’s contents, and the ‘*=’ assignment operator to repeat an array. (Contributed by Jason Orendorff.) * The ‘bsddb’ module has been replaced by version 4.1.6 of the PyBSDDB(1) package, providing a more complete interface to the transactional features of the BerkeleyDB library. The old version of the module has been renamed to ‘bsddb185’ and is no longer built automatically; you’ll have to edit ‘Modules/Setup’ to enable it. Note that the new ‘bsddb’ package is intended to be compatible with the old module, so be sure to file bugs if you discover any incompatibilities. When upgrading to Python 2.3, if the new interpreter is compiled with a new version of the underlying BerkeleyDB library, you will almost certainly have to convert your database files to the new version. You can do this fairly easily with the new scripts ‘db2pickle.py’ and ‘pickle2db.py’ which you will find in the distribution’s ‘Tools/scripts’ directory. If you’ve already been using the PyBSDDB package and importing it as ‘bsddb3’, you will have to change your ‘import’ statements to import it as ‘bsddb’. * The new *note bz2: 14. module is an interface to the bz2 data compression library. bz2-compressed data is usually smaller than corresponding *note zlib: 144.-compressed data. (Contributed by Gustavo Niemeyer.) * A set of standard date/time types has been added in the new *note datetime: 31. module. See the following section for more details. * The Distutils ‘Extension’ class now supports an extra constructor argument named `depends' for listing additional source files that an extension depends on. This lets Distutils recompile the module if any of the dependency files are modified. For example, if ‘sampmodule.c’ includes the header file ‘sample.h’, you would create the ‘Extension’ object like this: ext = Extension("samp", sources=["sampmodule.c"], depends=["sample.h"]) Modifying ‘sample.h’ would then cause the module to be recompiled. (Contributed by Jeremy Hylton.) * Other minor changes to Distutils: it now checks for the ‘CC’, ‘CFLAGS’, ‘CPP’, ‘LDFLAGS’, and ‘CPPFLAGS’ environment variables, using them to override the settings in Python’s configuration (contributed by Robert Weber). * Previously the *note doctest: 67. module would only search the docstrings of public methods and functions for test cases, but it now also examines private ones as well. The ‘DocTestSuite()’ function creates a *note unittest.TestSuite: 6ce. object from a set of *note doctest: 67. tests. * The new ‘gc.get_referents(object)’ function returns a list of all the objects referenced by `object'. * The *note getopt: 87. module gained a new function, ‘gnu_getopt()’, that supports the same arguments as the existing *note getopt(): 87. function but uses GNU-style scanning mode. The existing *note getopt(): 87. stops processing options as soon as a non-option argument is encountered, but in GNU-style mode processing continues, meaning that options and arguments can be mixed. For example: >>> getopt.getopt(['-f', 'filename', 'output', '-v'], 'f:v') ([('-f', 'filename')], ['output', '-v']) >>> getopt.gnu_getopt(['-f', 'filename', 'output', '-v'], 'f:v') ([('-f', 'filename'), ('-v', '')], ['output']) (Contributed by Peter Åstrand.) * The *note grp: 8b, *note pwd: d6, and *note resource: e0. modules now return enhanced tuples: >>> import grp >>> g = grp.getgrnam('amk') >>> g.gr_name, g.gr_gid ('amk', 500) * The *note gzip: 8c. module can now handle files exceeding 2 GiB. * The new *note heapq: 8e. module contains an implementation of a heap queue algorithm. A heap is an array-like data structure that keeps items in a partially sorted order such that, for every index `k', ‘heap[k] <= heap[2*k+1]’ and ‘heap[k] <= heap[2*k+2]’. This makes it quick to remove the smallest item, and inserting a new item while maintaining the heap property is O(lg n). (See ‘https://xlinux.nist.gov/dads//HTML/priorityque.html’ for more information about the priority queue data structure.) The *note heapq: 8e. module provides ‘heappush()’ and ‘heappop()’ functions for adding and removing items while maintaining the heap property on top of some other mutable Python sequence type. Here’s an example that uses a Python list: >>> import heapq >>> heap = [] >>> for item in [3, 7, 5, 11, 1]: ... heapq.heappush(heap, item) ... >>> heap [1, 3, 5, 11, 7] >>> heapq.heappop(heap) 1 >>> heapq.heappop(heap) 3 >>> heap [5, 7, 11] (Contributed by Kevin O’Connor.) * The IDLE integrated development environment has been updated using the code from the IDLEfork project (‘http://idlefork.sourceforge.net’). The most notable feature is that the code being developed is now executed in a subprocess, meaning that there’s no longer any need for manual ‘reload()’ operations. IDLE’s core code has been incorporated into the standard library as the ‘idlelib’ package. * The *note imaplib: 98. module now supports IMAP over SSL. (Contributed by Piers Lauder and Tino Lange.) * The *note itertools: a3. contains a number of useful functions for use with iterators, inspired by various functions provided by the ML and Haskell languages. For example, ‘itertools.ifilter(predicate, iterator)’ returns all elements in the iterator for which the function ‘predicate()’ returns *note True: 499, and ‘itertools.repeat(obj, N)’ returns ‘obj’ `N' times. There are a number of other functions in the module; see the package’s reference documentation for details. (Contributed by Raymond Hettinger.) * Two new functions in the *note math: b1. module, ‘degrees(rads)’ and ‘radians(degs)’, convert between radians and degrees. Other functions in the *note math: b1. module such as *note math.sin(): e0f. and *note math.cos(): e10. have always required input values measured in radians. Also, an optional `base' argument was added to *note math.log(): e11. to make it easier to compute logarithms for bases other than ‘e’ and ‘10’. (Contributed by Raymond Hettinger.) * Several new POSIX functions (‘getpgid()’, ‘killpg()’, ‘lchown()’, ‘loadavg()’, ‘major()’, ‘makedev()’, ‘minor()’, and ‘mknod()’) were added to the *note posix: d1. module that underlies the *note os: c4. module. (Contributed by Gustavo Niemeyer, Geert Jansen, and Denis S. Otkidach.) * In the *note os: c4. module, the ‘*stat()’ family of functions can now report fractions of a second in a timestamp. Such time stamps are represented as floats, similar to the value returned by *note time.time(): 31d. During testing, it was found that some applications will break if time stamps are floats. For compatibility, when using the tuple interface of the ‘stat_result’ time stamps will be represented as integers. When using named fields (a feature first introduced in Python 2.2), time stamps are still represented as integers, unless ‘os.stat_float_times()’ is invoked to enable float return values: >>> os.stat("/tmp").st_mtime 1034791200 >>> os.stat_float_times(True) >>> os.stat("/tmp").st_mtime 1034791200.6335014 In Python 2.4, the default will change to always returning floats. Application developers should enable this feature only if all their libraries work properly when confronted with floating point time stamps, or if they use the tuple API. If used, the feature should be activated on an application level instead of trying to enable it on a per-use basis. * The *note optparse: c3. module contains a new parser for command-line arguments that can convert option values to a particular Python type and will automatically generate a usage message. See the following section for more details. * The old and never-documented ‘linuxaudiodev’ module has been deprecated, and a new version named *note ossaudiodev: c6. has been added. The module was renamed because the OSS sound drivers can be used on platforms other than Linux, and the interface has also been tidied and brought up to date in various ways. (Contributed by Greg Ward and Nicholas FitzRoy-Dale.) * The new *note platform: ce. module contains a number of functions that try to determine various properties of the platform you’re running on. There are functions for getting the architecture, CPU type, the Windows OS version, and even the Linux distribution version. (Contributed by Marc-André Lemburg.) * The parser objects provided by the ‘pyexpat’ module can now optionally buffer character data, resulting in fewer calls to your character data handler and therefore faster performance. Setting the parser object’s ‘buffer_text’ attribute to *note True: 499. will enable buffering. * The ‘sample(population, k)’ function was added to the *note random: dc. module. `population' is a sequence or ‘xrange’ object containing the elements of a population, and ‘sample()’ chooses `k' elements from the population without replacing chosen elements. `k' can be any value up to ‘len(population)’. For example: >>> days = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'St', 'Sn'] >>> random.sample(days, 3) # Choose 3 elements ['St', 'Sn', 'Th'] >>> random.sample(days, 7) # Choose 7 elements ['Tu', 'Th', 'Mo', 'We', 'St', 'Fr', 'Sn'] >>> random.sample(days, 7) # Choose 7 again ['We', 'Mo', 'Sn', 'Fr', 'Tu', 'St', 'Th'] >>> random.sample(days, 8) # Can't choose eight Traceback (most recent call last): File "", line 1, in ? File "random.py", line 414, in sample raise ValueError, "sample larger than population" ValueError: sample larger than population >>> random.sample(xrange(1,10000,2), 10) # Choose ten odd nos. under 10000 [3407, 3805, 1505, 7023, 2401, 2267, 9733, 3151, 8083, 9195] The *note random: dc. module now uses a new algorithm, the Mersenne Twister, implemented in C. It’s faster and more extensively studied than the previous algorithm. (All changes contributed by Raymond Hettinger.) * The *note readline: de. module also gained a number of new functions: ‘get_history_item()’, ‘get_current_history_length()’, and ‘redisplay()’. * The ‘rexec’ and ‘Bastion’ modules have been declared dead, and attempts to import them will fail with a *note RuntimeError: 2ba. New-style classes provide new ways to break out of the restricted execution environment provided by ‘rexec’, and no one has interest in fixing them or time to do so. If you have applications using ‘rexec’, rewrite them to use something else. (Sticking with Python 2.2 or 2.1 will not make your applications any safer because there are known bugs in the ‘rexec’ module in those versions. To repeat: if you’re using ‘rexec’, stop using it immediately.) * The ‘rotor’ module has been deprecated because the algorithm it uses for encryption is not believed to be secure. If you need encryption, use one of the several AES Python modules that are available separately. * The *note shutil: e9. module gained a ‘move(src, dest)’ function that recursively moves a file or directory to a new location. * Support for more advanced POSIX signal handling was added to the *note signal: ea. but then removed again as it proved impossible to make it work reliably across platforms. * The *note socket: ef. module now supports timeouts. You can call the ‘settimeout(t)’ method on a socket object to set a timeout of `t' seconds. Subsequent socket operations that take longer than `t' seconds to complete will abort and raise a *note socket.timeout: c0e. exception. The original timeout implementation was by Tim O’Malley. Michael Gilfix integrated it into the Python *note socket: ef. module and shepherded it through a lengthy review. After the code was checked in, Guido van Rossum rewrote parts of it. (This is a good example of a collaborative development process in action.) * On Windows, the *note socket: ef. module now ships with Secure Sockets Layer (SSL) support. * The value of the C ‘PYTHON_API_VERSION’ macro is now exposed at the Python level as ‘sys.api_version’. The current exception can be cleared by calling the new ‘sys.exc_clear()’ function. * The new *note tarfile: 101. module allows reading from and writing to ‘tar’-format archive files. (Contributed by Lars Gustäbel.) * The new *note textwrap: 108. module contains functions for wrapping strings containing paragraphs of text. The ‘wrap(text, width)’ function takes a string and returns a list containing the text split into lines of no more than the chosen width. The ‘fill(text, width)’ function returns a single string, reformatted to fit into lines no longer than the chosen width. (As you can guess, ‘fill()’ is built on top of ‘wrap()’. For example: >>> import textwrap >>> paragraph = "Not a whit, we defy augury: ... more text ..." >>> textwrap.wrap(paragraph, 60) ["Not a whit, we defy augury: there's a special providence in", "the fall of a sparrow. If it be now, 'tis not to come; if it", ...] >>> print textwrap.fill(paragraph, 35) Not a whit, we defy augury: there's a special providence in the fall of a sparrow. If it be now, 'tis not to come; if it be not to come, it will be now; if it be not now, yet it will come: the readiness is all. >>> The module also contains a ‘TextWrapper’ class that actually implements the text wrapping strategy. Both the ‘TextWrapper’ class and the ‘wrap()’ and ‘fill()’ functions support a number of additional keyword arguments for fine-tuning the formatting; consult the module’s documentation for details. (Contributed by Greg Ward.) * The ‘thread’ and *note threading: 109. modules now have companion modules, ‘dummy_thread’ and *note dummy_threading: 68, that provide a do-nothing implementation of the ‘thread’ module’s interface for platforms where threads are not supported. The intention is to simplify thread-aware modules (ones that `don’t' rely on threads to run) by putting the following code at the top: try: import threading as _threading except ImportError: import dummy_threading as _threading In this example, ‘_threading’ is used as the module name to make it clear that the module being used is not necessarily the actual *note threading: 109. module. Code can call functions and use classes in ‘_threading’ whether or not threads are supported, avoiding an *note if: de7. statement and making the code slightly clearer. This module will not magically make multithreaded code run without threads; code that waits for another thread to return or to do something will simply hang forever. * The *note time: 10a. module’s ‘strptime()’ function has long been an annoyance because it uses the platform C library’s ‘strptime()’ implementation, and different platforms sometimes have odd bugs. Brett Cannon contributed a portable implementation that’s written in pure Python and should behave identically on all platforms. * The new *note timeit: 10b. module helps measure how long snippets of Python code take to execute. The ‘timeit.py’ file can be run directly from the command line, or the module’s ‘Timer’ class can be imported and used directly. Here’s a short example that figures out whether it’s faster to convert an 8-bit string to Unicode by appending an empty Unicode string to it or by using the ‘unicode()’ function: import timeit timer1 = timeit.Timer('unicode("abc")') timer2 = timeit.Timer('"abc" + u""') # Run three trials print timer1.repeat(repeat=3, number=100000) print timer2.repeat(repeat=3, number=100000) # On my laptop this outputs: # [0.36831796169281006, 0.37441694736480713, 0.35304892063140869] # [0.17574405670166016, 0.18193507194519043, 0.17565798759460449] * The ‘Tix’ module has received various bug fixes and updates for the current version of the Tix package. * The ‘Tkinter’ module now works with a thread-enabled version of Tcl. Tcl’s threading model requires that widgets only be accessed from the thread in which they’re created; accesses from another thread can cause Tcl to panic. For certain Tcl interfaces, ‘Tkinter’ will now automatically avoid this when a widget is accessed from a different thread by marshalling a command, passing it to the correct thread, and waiting for the results. Other interfaces can’t be handled automatically but ‘Tkinter’ will now raise an exception on such an access so that you can at least find out about the problem. See ‘https://mail.python.org/pipermail/python-dev/2002-December/031107.html’ for a more detailed explanation of this change. (Implemented by Martin von Löwis.) * Calling Tcl methods through ‘_tkinter’ no longer returns only strings. Instead, if Tcl returns other objects those objects are converted to their Python equivalent, if one exists, or wrapped with a ‘_tkinter.Tcl_Obj’ object if no Python equivalent exists. This behavior can be controlled through the ‘wantobjects()’ method of ‘tkapp’ objects. When using ‘_tkinter’ through the ‘Tkinter’ module (as most Tkinter applications will), this feature is always activated. It should not cause compatibility problems, since Tkinter would always convert string results to Python types where possible. If any incompatibilities are found, the old behavior can be restored by setting the ‘wantobjects’ variable in the ‘Tkinter’ module to false before creating the first ‘tkapp’ object. import Tkinter Tkinter.wantobjects = 0 Any breakage caused by this change should be reported as a bug. * The ‘UserDict’ module has a new ‘DictMixin’ class which defines all dictionary methods for classes that already have a minimum mapping interface. This greatly simplifies writing classes that need to be substitutable for dictionaries, such as the classes in the *note shelve: e7. module. Adding the mix-in as a superclass provides the full dictionary interface whenever the class defines *note __getitem__(): 27c, *note __setitem__(): c62, *note __delitem__(): c63, and ‘keys()’. For example: >>> import UserDict >>> class SeqDict(UserDict.DictMixin): ... """Dictionary lookalike implemented with lists.""" ... def __init__(self): ... self.keylist = [] ... self.valuelist = [] ... def __getitem__(self, key): ... try: ... i = self.keylist.index(key) ... except ValueError: ... raise KeyError ... return self.valuelist[i] ... def __setitem__(self, key, value): ... try: ... i = self.keylist.index(key) ... self.valuelist[i] = value ... except ValueError: ... self.keylist.append(key) ... self.valuelist.append(value) ... def __delitem__(self, key): ... try: ... i = self.keylist.index(key) ... except ValueError: ... raise KeyError ... self.keylist.pop(i) ... self.valuelist.pop(i) ... def keys(self): ... return list(self.keylist) ... >>> s = SeqDict() >>> dir(s) # See that other dictionary methods are implemented ['__cmp__', '__contains__', '__delitem__', '__doc__', '__getitem__', '__init__', '__iter__', '__len__', '__module__', '__repr__', '__setitem__', 'clear', 'get', 'has_key', 'items', 'iteritems', 'iterkeys', 'itervalues', 'keylist', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'valuelist', 'values'] (Contributed by Raymond Hettinger.) * The DOM implementation in *note xml.dom.minidom: 135. can now generate XML output in a particular encoding by providing an optional encoding argument to the ‘toxml()’ and ‘toprettyxml()’ methods of DOM nodes. * The ‘xmlrpclib’ module now supports an XML-RPC extension for handling nil data values such as Python’s ‘None’. Nil values are always supported on unmarshalling an XML-RPC response. To generate requests containing ‘None’, you must supply a true value for the `allow_none' parameter when creating a ‘Marshaller’ instance. * The new ‘DocXMLRPCServer’ module allows writing self-documenting XML-RPC servers. Run it in demo mode (as a program) to see it in action. Pointing the Web browser to the RPC server produces pydoc-style documentation; pointing xmlrpclib to the server allows invoking the actual methods. (Contributed by Brian Quinlan.) * Support for internationalized domain names (RFCs 3454, 3490, 3491, and 3492) has been added. The “idna” encoding can be used to convert between a Unicode domain name and the ASCII-compatible encoding (ACE) of that name. >{}>{}> u"www.Alliancefrançaise.nu".encode("idna") 'www.xn--alliancefranaise-npb.nu' The *note socket: ef. module has also been extended to transparently convert Unicode hostnames to the ACE version before passing them to the C library. Modules that deal with hostnames such as ‘httplib’ and *note ftplib: 84.) also support Unicode host names; ‘httplib’ also sends HTTP ‘Host’ headers using the ACE version of the domain name. *note urllib: 11d. supports Unicode URLs with non-ASCII host names as long as the ‘path’ part of the URL is ASCII only. To implement this change, the *note stringprep: f7. module, the ‘mkstringprep’ tool and the ‘punycode’ encoding have been added. * Menu: * Date/Time Type:: * The optparse Module:: ---------- Footnotes ---------- (1) http://pybsddb.sourceforge.net  File: python.info, Node: Date/Time Type, Next: The optparse Module, Up: New Improved and Deprecated Modules<4> 1.14.17.1 Date/Time Type ........................ Date and time types suitable for expressing timestamps were added as the *note datetime: 31. module. The types don’t support different calendars or many fancy features, and just stick to the basics of representing time. The three primary types are: ‘date’, representing a day, month, and year; *note time: 4f3, consisting of hour, minute, and second; and *note datetime: 194, which contains all the attributes of both ‘date’ and *note time: 4f3. There’s also a ‘timedelta’ class representing differences between two points in time, and time zone logic is implemented by classes inheriting from the abstract ‘tzinfo’ class. You can create instances of ‘date’ and *note time: 4f3. by either supplying keyword arguments to the appropriate constructor, e.g. ‘datetime.date(year=1972, month=10, day=15)’, or by using one of a number of class methods. For example, the ‘date.today()’ class method returns the current local date. Once created, instances of the date/time classes are all immutable. There are a number of methods for producing formatted strings from objects: >>> import datetime >>> now = datetime.datetime.now() >>> now.isoformat() '2002-12-30T21:27:03.994956' >>> now.ctime() # Only available on date, datetime 'Mon Dec 30 21:27:03 2002' >>> now.strftime('%Y %d %b') '2002 30 Dec' The ‘replace()’ method allows modifying one or more fields of a ‘date’ or *note datetime: 194. instance, returning a new instance: >>> d = datetime.datetime.now() >>> d datetime.datetime(2002, 12, 30, 22, 15, 38, 827738) >>> d.replace(year=2001, hour = 12) datetime.datetime(2001, 12, 30, 12, 15, 38, 827738) >>> Instances can be compared, hashed, and converted to strings (the result is the same as that of ‘isoformat()’). ‘date’ and *note datetime: 194. instances can be subtracted from each other, and added to ‘timedelta’ instances. The largest missing feature is that there’s no standard library support for parsing strings and getting back a ‘date’ or *note datetime: 194. For more information, refer to the module’s reference documentation. (Contributed by Tim Peters.)  File: python.info, Node: The optparse Module, Prev: Date/Time Type, Up: New Improved and Deprecated Modules<4> 1.14.17.2 The optparse Module ............................. The *note getopt: 87. module provides simple parsing of command-line arguments. The new *note optparse: c3. module (originally named Optik) provides more elaborate command-line parsing that follows the Unix conventions, automatically creates the output for ‘--help’, and can perform different actions for different options. You start by creating an instance of ‘OptionParser’ and telling it what your program’s options are. import sys from optparse import OptionParser op = OptionParser() op.add_option('-i', '--input', action='store', type='string', dest='input', help='set input filename') op.add_option('-l', '--length', action='store', type='int', dest='length', help='set maximum length of output') Parsing a command line is then done by calling the ‘parse_args()’ method. options, args = op.parse_args(sys.argv[1:]) print options print args This returns an object containing all of the option values, and a list of strings containing the remaining arguments. Invoking the script with the various arguments now works as you’d expect it to. Note that the length argument is automatically converted to an integer. $ ./python opt.py -i data arg1 ['arg1'] $ ./python opt.py --input=data --length=4 [] $ The help message is automatically generated for you: $ ./python opt.py --help usage: opt.py [options] options: -h, --help show this help message and exit -iINPUT, --input=INPUT set input filename -lLENGTH, --length=LENGTH set maximum length of output $ See the module’s documentation for more details. Optik was written by Greg Ward, with suggestions from the readers of the Getopt SIG.  File: python.info, Node: Pymalloc A Specialized Object Allocator, Next: Build and C API Changes<12>, Prev: New Improved and Deprecated Modules<4>, Up: What’s New in Python 2 3 1.14.18 Pymalloc: A Specialized Object Allocator ------------------------------------------------ Pymalloc, a specialized object allocator written by Vladimir Marangozov, was a feature added to Python 2.1. Pymalloc is intended to be faster than the system ‘malloc()’ and to have less memory overhead for allocation patterns typical of Python programs. The allocator uses C’s ‘malloc()’ function to get large pools of memory and then fulfills smaller memory requests from these pools. In 2.1 and 2.2, pymalloc was an experimental feature and wasn’t enabled by default; you had to explicitly enable it when compiling Python by providing the ‘--with-pymalloc’ option to the ‘configure’ script. In 2.3, pymalloc has had further enhancements and is now enabled by default; you’ll have to supply ‘--without-pymalloc’ to disable it. This change is transparent to code written in Python; however, pymalloc may expose bugs in C extensions. Authors of C extension modules should test their code with pymalloc enabled, because some incorrect code may cause core dumps at runtime. There’s one particularly common error that causes problems. There are a number of memory allocation functions in Python’s C API that have previously just been aliases for the C library’s ‘malloc()’ and ‘free()’, meaning that if you accidentally called mismatched functions the error wouldn’t be noticeable. When the object allocator is enabled, these functions aren’t aliases of ‘malloc()’ and ‘free()’ any more, and calling the wrong function to free memory may get you a core dump. For example, if memory was allocated using *note PyObject_Malloc(): 508, it has to be freed using *note PyObject_Free(): 504, not ‘free()’. A few modules included with Python fell afoul of this and had to be fixed; doubtless there are more third-party modules that will have the same problem. As part of this change, the confusing multiple interfaces for allocating memory have been consolidated down into two API families. Memory allocated with one family must not be manipulated with functions from the other family. There is one family for allocating chunks of memory and another family of functions specifically for allocating Python objects. * To allocate and free an undistinguished chunk of memory use the “raw memory” family: *note PyMem_Malloc(): 505, *note PyMem_Realloc(): 96f, and *note PyMem_Free(): da9. * The “object memory” family is the interface to the pymalloc facility described above and is biased towards a large number of “small” allocations: *note PyObject_Malloc(): 508, *note PyObject_Realloc(): daa, and *note PyObject_Free(): 504. * To allocate and free Python objects, use the “object” family *note PyObject_New(): 2d2, *note PyObject_NewVar(): 2d3, and *note PyObject_Del(): e16. Thanks to lots of work by Tim Peters, pymalloc in 2.3 also provides debugging features to catch memory overwrites and doubled frees in both extension modules and in the interpreter itself. To enable this support, compile a debugging version of the Python interpreter by running ‘configure’ with ‘--with-pydebug’. To aid extension writers, a header file ‘Misc/pymemcompat.h’ is distributed with the source to Python 2.3 that allows Python extensions to use the 2.3 interfaces to memory allocation while compiling against any version of Python since 1.5.2. You would copy the file from Python’s source distribution and bundle it with the source of your extension. See also ........ ‘https://hg.python.org/cpython/file/default/Objects/obmalloc.c’ For the full details of the pymalloc implementation, see the comments at the top of the file ‘Objects/obmalloc.c’ in the Python source code. The above link points to the file within the python.org SVN browser.  File: python.info, Node: Build and C API Changes<12>, Next: Other Changes and Fixes<2>, Prev: Pymalloc A Specialized Object Allocator, Up: What’s New in Python 2 3 1.14.19 Build and C API Changes ------------------------------- Changes to Python’s build process and to the C API include: * The cycle detection implementation used by the garbage collection has proven to be stable, so it’s now been made mandatory. You can no longer compile Python without it, and the ‘--with-cycle-gc’ switch to ‘configure’ has been removed. * Python can now optionally be built as a shared library (‘libpython2.3.so’) by supplying ‘--enable-shared’ when running Python’s ‘configure’ script. (Contributed by Ondrej Palkovsky.) * The ‘DL_EXPORT’ and ‘DL_IMPORT’ macros are now deprecated. Initialization functions for Python extension modules should now be declared using the new macro ‘PyMODINIT_FUNC’, while the Python core will generally use the ‘PyAPI_FUNC’ and ‘PyAPI_DATA’ macros. * The interpreter can be compiled without any docstrings for the built-in functions and modules by supplying ‘--without-doc-strings’ to the ‘configure’ script. This makes the Python executable about 10% smaller, but will also mean that you can’t get help for Python’s built-ins. (Contributed by Gustavo Niemeyer.) * The ‘PyArg_NoArgs()’ macro is now deprecated, and code that uses it should be changed. For Python 2.2 and later, the method definition table can specify the *note METH_NOARGS: e18. flag, signalling that there are no arguments, and the argument checking can then be removed. If compatibility with pre-2.2 versions of Python is important, the code could use ‘PyArg_ParseTuple(args, "")’ instead, but this will be slower than using *note METH_NOARGS: e18. * *note PyArg_ParseTuple(): 26a. accepts new format characters for various sizes of unsigned integers: ‘B’ for ‘unsigned char’, ‘H’ for ‘unsigned short int’, ‘I’ for ‘unsigned int’, and ‘K’ for ‘unsigned long long’. * A new function, ‘PyObject_DelItemString(mapping, char *key)’ was added as shorthand for ‘PyObject_DelItem(mapping, PyString_New(key))’. * File objects now manage their internal string buffer differently, increasing it exponentially when needed. This results in the benchmark tests in ‘Lib/test/test_bufio.py’ speeding up considerably (from 57 seconds to 1.7 seconds, according to one measurement). * It’s now possible to define class and static methods for a C extension type by setting either the *note METH_CLASS: e19. or *note METH_STATIC: e1a. flags in a method’s *note PyMethodDef: e1b. structure. * Python now includes a copy of the Expat XML parser’s source code, removing any dependence on a system version or local installation of Expat. * If you dynamically allocate type objects in your extension, you should be aware of a change in the rules relating to the ‘__module__’ and *note __name__: c67. attributes. In summary, you will want to ensure the type’s dictionary contains a ‘'__module__'’ key; making the module name the part of the type name leading up to the final period will no longer have the desired effect. For more detail, read the API reference documentation or the source. * Menu: * Port-Specific Changes: Port-Specific Changes<3>.  File: python.info, Node: Port-Specific Changes<3>, Up: Build and C API Changes<12> 1.14.19.1 Port-Specific Changes ............................... Support for a port to IBM’s OS/2 using the EMX runtime environment was merged into the main Python source tree. EMX is a POSIX emulation layer over the OS/2 system APIs. The Python port for EMX tries to support all the POSIX-like capability exposed by the EMX runtime, and mostly succeeds; ‘fork()’ and *note fcntl(): 7e. are restricted by the limitations of the underlying emulation layer. The standard OS/2 port, which uses IBM’s Visual Age compiler, also gained support for case-sensitive import semantics as part of the integration of the EMX port into CVS. (Contributed by Andrew MacIntyre.) On MacOS, most toolbox modules have been weaklinked to improve backward compatibility. This means that modules will no longer fail to load if a single routine is missing on the current OS version. Instead calling the missing routine will raise an exception. (Contributed by Jack Jansen.) The RPM spec files, found in the ‘Misc/RPM/’ directory in the Python source distribution, were updated for 2.3. (Contributed by Sean Reifschneider.) Other new platforms now supported by Python include AtheOS (‘http://www.atheos.cx/’), GNU/Hurd, and OpenVMS.  File: python.info, Node: Other Changes and Fixes<2>, Next: Porting to Python 2 3, Prev: Build and C API Changes<12>, Up: What’s New in Python 2 3 1.14.20 Other Changes and Fixes ------------------------------- As usual, there were a bunch of other improvements and bugfixes scattered throughout the source tree. A search through the CVS change logs finds there were 523 patches applied and 514 bugs fixed between Python 2.2 and 2.3. Both figures are likely to be underestimates. Some of the more notable changes are: * If the *note PYTHONINSPECT: e1e. environment variable is set, the Python interpreter will enter the interactive prompt after running a Python program, as if Python had been invoked with the *note -i: e1f. option. The environment variable can be set before running the Python interpreter, or it can be set by the Python program as part of its execution. * The ‘regrtest.py’ script now provides a way to allow “all resources except `foo'.” A resource name passed to the ‘-u’ option can now be prefixed with a hyphen (‘'-'’) to mean “remove this resource.” For example, the option ‘‘-uall,-bsddb’’ could be used to enable the use of all resources except ‘bsddb’. * The tools used to build the documentation now work under Cygwin as well as Unix. * The ‘SET_LINENO’ opcode has been removed. Back in the mists of time, this opcode was needed to produce line numbers in tracebacks and support trace functions (for, e.g., *note pdb: c9.). Since Python 1.5, the line numbers in tracebacks have been computed using a different mechanism that works with “python -O”. For Python 2.3 Michael Hudson implemented a similar scheme to determine when to call the trace function, removing the need for ‘SET_LINENO’ entirely. It would be difficult to detect any resulting difference from Python code, apart from a slight speed up when Python is run without *note -O: 68b. C extensions that access the ‘f_lineno’ field of frame objects should instead call ‘PyCode_Addr2Line(f->f_code, f->f_lasti)’. This will have the added effect of making the code work as desired under “python -O” in earlier versions of Python. A nifty new feature is that trace functions can now assign to the ‘f_lineno’ attribute of frame objects, changing the line that will be executed next. A ‘jump’ command has been added to the *note pdb: c9. debugger taking advantage of this new feature. (Implemented by Richie Hindle.)  File: python.info, Node: Porting to Python 2 3, Next: Acknowledgements<5>, Prev: Other Changes and Fixes<2>, Up: What’s New in Python 2 3 1.14.21 Porting to Python 2.3 ----------------------------- This section lists previously described changes that may require changes to your code: * *note yield: 18f. is now always a keyword; if it’s used as a variable name in your code, a different name must be chosen. * For strings `X' and `Y', ‘X in Y’ now works if `X' is more than one character long. * The *note int(): 184. type constructor will now return a long integer instead of raising an *note OverflowError: 960. when a string or floating-point number is too large to fit into an integer. * If you have Unicode strings that contain 8-bit characters, you must declare the file’s encoding (UTF-8, Latin-1, or whatever) by adding a comment to the top of the file. See section *note PEP 263; Source Code Encodings: de9. for more information. * Calling Tcl methods through ‘_tkinter’ no longer returns only strings. Instead, if Tcl returns other objects those objects are converted to their Python equivalent, if one exists, or wrapped with a ‘_tkinter.Tcl_Obj’ object if no Python equivalent exists. * Large octal and hex literals such as ‘0xffffffff’ now trigger a *note FutureWarning: 325. Currently they’re stored as 32-bit numbers and result in a negative value, but in Python 2.4 they’ll become positive long integers. There are a few ways to fix this warning. If you really need a positive number, just add an ‘L’ to the end of the literal. If you’re trying to get a 32-bit integer with low bits set and have previously used an expression such as ‘~(1 << 31)’, it’s probably clearest to start with all bits set and clear the desired upper bits. For example, to clear just the top bit (bit 31), you could write ‘0xffffffffL &~(1L<<31)’. * You can no longer disable assertions by assigning to ‘__debug__’. * The Distutils ‘setup()’ function has gained various new keyword arguments such as `depends'. Old versions of the Distutils will abort if passed unknown keywords. A solution is to check for the presence of the new ‘get_distutil_options()’ function in your ‘setup.py’ and only uses the new keywords with a version of the Distutils that supports them: from distutils import core kw = {'sources': 'foo.c', ...} if hasattr(core, 'get_distutil_options'): kw['depends'] = ['foo.h'] ext = Extension(**kw) * Using ‘None’ as a variable name will now result in a *note SyntaxWarning: 191. warning. * Names of extension types defined by the modules included with Python now contain the module and a ‘'.'’ in front of the type name.  File: python.info, Node: Acknowledgements<5>, Prev: Porting to Python 2 3, Up: What’s New in Python 2 3 1.14.22 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Jeff Bauer, Simon Brunning, Brett Cannon, Michael Chermside, Andrew Dalke, Scott David Daniels, Fred L. Drake, Jr., David Fraser, Kelly Gerber, Raymond Hettinger, Michael Hudson, Chris Lambert, Detlef Lannert, Martin von Löwis, Andrew MacIntyre, Lalo Martins, Chad Netzer, Gustavo Niemeyer, Neal Norwitz, Hans Nowak, Chris Reedy, Francesco Ricciardi, Vinay Sajip, Neil Schemenauer, Roman Suzi, Jason Tishler, Just van Rossum.  File: python.info, Node: What’s New in Python 2 2, Next: What’s New in Python 2 1, Prev: What’s New in Python 2 3, Up: What’s New in Python 1.15 What’s New in Python 2.2 ============================= Author: A.M. Kuchling * Menu: * Introduction:: * PEPs 252 and 253; Type and Class Changes: PEPs 252 and 253 Type and Class Changes. * PEP 234; Iterators: PEP 234 Iterators. * PEP 255; Simple Generators: PEP 255 Simple Generators<2>. * PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers<2>. * PEP 238; Changing the Division Operator: PEP 238 Changing the Division Operator. * Unicode Changes:: * PEP 227; Nested Scopes: PEP 227 Nested Scopes. * New and Improved Modules: New and Improved Modules<3>. * Interpreter Changes and Fixes:: * Other Changes and Fixes: Other Changes and Fixes<3>. * Acknowledgements: Acknowledgements<6>.  File: python.info, Node: Introduction, Next: PEPs 252 and 253 Type and Class Changes, Up: What’s New in Python 2 2 1.15.1 Introduction ------------------- This article explains the new features in Python 2.2.2, released on October 14, 2002. Python 2.2.2 is a bugfix release of Python 2.2, originally released on December 21, 2001. Python 2.2 can be thought of as the “cleanup release”. There are some features such as generators and iterators that are completely new, but most of the changes, significant and far-reaching though they may be, are aimed at cleaning up irregularities and dark corners of the language design. This article doesn’t attempt to provide a complete specification of the new features, but instead provides a convenient overview. For full details, you should refer to the documentation for Python 2.2, such as the Python Library Reference(1) and the Python Reference Manual(2). If you want to understand the complete implementation and design rationale for a change, refer to the PEP for a particular new feature. ---------- Footnotes ---------- (1) https://docs.python.org/2.2/lib/lib.html (2) https://docs.python.org/2.2/ref/ref.html  File: python.info, Node: PEPs 252 and 253 Type and Class Changes, Next: PEP 234 Iterators, Prev: Introduction, Up: What’s New in Python 2 2 1.15.2 PEPs 252 and 253: Type and Class Changes ----------------------------------------------- The largest and most far-reaching changes in Python 2.2 are to Python’s model of objects and classes. The changes should be backward compatible, so it’s likely that your code will continue to run unchanged, but the changes provide some amazing new capabilities. Before beginning this, the longest and most complicated section of this article, I’ll provide an overview of the changes and offer some comments. A long time ago I wrote a Web page listing flaws in Python’s design. One of the most significant flaws was that it’s impossible to subclass Python types implemented in C. In particular, it’s not possible to subclass built-in types, so you can’t just subclass, say, lists in order to add a single useful method to them. The ‘UserList’ module provides a class that supports all of the methods of lists and that can be subclassed further, but there’s lots of C code that expects a regular Python list and won’t accept a ‘UserList’ instance. Python 2.2 fixes this, and in the process adds some exciting new capabilities. A brief summary: * You can subclass built-in types such as lists and even integers, and your subclasses should work in every place that requires the original type. * It’s now possible to define static and class methods, in addition to the instance methods available in previous versions of Python. * It’s also possible to automatically call methods on accessing or setting an instance attribute by using a new mechanism called `properties'. Many uses of *note __getattr__(): 31a. can be rewritten to use properties instead, making the resulting code simpler and faster. As a small side benefit, attributes can now have docstrings, too. * The list of legal attributes for an instance can be limited to a particular set using `slots', making it possible to safeguard against typos and perhaps make more optimizations possible in future versions of Python. Some users have voiced concern about all these changes. Sure, they say, the new features are neat and lend themselves to all sorts of tricks that weren’t possible in previous versions of Python, but they also make the language more complicated. Some people have said that they’ve always recommended Python for its simplicity, and feel that its simplicity is being lost. Personally, I think there’s no need to worry. Many of the new features are quite esoteric, and you can write a lot of Python code without ever needed to be aware of them. Writing a simple class is no more difficult than it ever was, so you don’t need to bother learning or teaching them unless they’re actually needed. Some very complicated tasks that were previously only possible from C will now be possible in pure Python, and to my mind that’s all for the better. I’m not going to attempt to cover every single corner case and small change that were required to make the new features work. Instead this section will paint only the broad strokes. See section *note Related Links: e27, “Related Links”, for further sources of information about Python 2.2’s new object model. * Menu: * Old and New Classes:: * Descriptors:: * Multiple Inheritance; The Diamond Rule: Multiple Inheritance The Diamond Rule. * Attribute Access:: * Related Links::  File: python.info, Node: Old and New Classes, Next: Descriptors, Up: PEPs 252 and 253 Type and Class Changes 1.15.2.1 Old and New Classes ............................ First, you should know that Python 2.2 really has two kinds of classes: classic or old-style classes, and new-style classes. The old-style class model is exactly the same as the class model in earlier versions of Python. All the new features described in this section apply only to new-style classes. This divergence isn’t intended to last forever; eventually old-style classes will be dropped, possibly in Python 3.0. So how do you define a new-style class? You do it by subclassing an existing new-style class. Most of Python’s built-in types, such as integers, lists, dictionaries, and even files, are new-style classes now. A new-style class named *note object: 2b0, the base class for all built-in types, has also been added so if no built-in type is suitable, you can just subclass *note object: 2b0.: class C(object): def __init__ (self): ... ... This means that *note class: c6a. statements that don’t have any base classes are always classic classes in Python 2.2. (Actually you can also change this by setting a module-level variable named ‘__metaclass__’ — see PEP 253(1) for the details — but it’s easier to just subclass *note object: 2b0.) The type objects for the built-in types are available as built-ins, named using a clever trick. Python has always had built-in functions named *note int(): 184, *note float(): 187, and *note str(): 330. In 2.2, they aren’t functions any more, but type objects that behave as factories when called. >>> int >>> int('123') 123 To make the set of types complete, new type objects such as *note dict(): 1b8. and ‘file()’ have been added. Here’s a more interesting example, adding a ‘lock()’ method to file objects: class LockableFile(file): def lock (self, operation, length=0, start=0, whence=0): import fcntl return fcntl.lockf(self.fileno(), operation, length, start, whence) The now-obsolete ‘posixfile’ module contained a class that emulated all of a file object’s methods and also added a ‘lock()’ method, but this class couldn’t be passed to internal functions that expected a built-in file, something which is possible with our new ‘LockableFile’. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0253  File: python.info, Node: Descriptors, Next: Multiple Inheritance The Diamond Rule, Prev: Old and New Classes, Up: PEPs 252 and 253 Type and Class Changes 1.15.2.2 Descriptors .................... In previous versions of Python, there was no consistent way to discover what attributes and methods were supported by an object. There were some informal conventions, such as defining ‘__members__’ and ‘__methods__’ attributes that were lists of names, but often the author of an extension type or a class wouldn’t bother to define them. You could fall back on inspecting the *note __dict__: 4fc. of an object, but when class inheritance or an arbitrary *note __getattr__(): 31a. hook were in use this could still be inaccurate. The one big idea underlying the new class model is that an API for describing the attributes of an object using `descriptors' has been formalized. Descriptors specify the value of an attribute, stating whether it’s a method or a field. With the descriptor API, static methods and class methods become possible, as well as more exotic constructs. Attribute descriptors are objects that live inside class objects, and have a few attributes of their own: * *note __name__: c67. is the attribute’s name. * ‘__doc__’ is the attribute’s docstring. * ‘__get__(object)’ is a method that retrieves the attribute value from `object'. * ‘__set__(object, value)’ sets the attribute on `object' to `value'. * ‘__delete__(object, value)’ deletes the `value' attribute of `object'. For example, when you write ‘obj.x’, the steps that Python actually performs are: descriptor = obj.__class__.x descriptor.__get__(obj) For methods, ‘descriptor.__get__()’ returns a temporary object that’s callable, and wraps up the instance and the method to be called on it. This is also why static methods and class methods are now possible; they have descriptors that wrap up just the method, or the method and the class. As a brief explanation of these new kinds of methods, static methods aren’t passed the instance, and therefore resemble regular functions. Class methods are passed the class of the object, but not the object itself. Static and class methods are defined like this: class C(object): def f(arg1, arg2): ... f = staticmethod(f) def g(cls, arg1, arg2): ... g = classmethod(g) The *note staticmethod(): 1d9. function takes the function ‘f()’, and returns it wrapped up in a descriptor so it can be stored in the class object. You might expect there to be special syntax for creating such methods (‘def static f’, ‘defstatic f()’, or something like that) but no such syntax has been defined yet; that’s been left for future versions of Python. More new features, such as slots and properties, are also implemented as new kinds of descriptors, and it’s not difficult to write a descriptor class that does something novel. For example, it would be possible to write a descriptor class that made it possible to write Eiffel-style preconditions and postconditions for a method. A class that used this feature might be defined like this: from eiffel import eiffelmethod class C(object): def f(self, arg1, arg2): # The actual function ... def pre_f(self): # Check preconditions ... def post_f(self): # Check postconditions ... f = eiffelmethod(f, pre_f, post_f) Note that a person using the new ‘eiffelmethod()’ doesn’t have to understand anything about descriptors. This is why I think the new features don’t increase the basic complexity of the language. There will be a few wizards who need to know about it in order to write ‘eiffelmethod()’ or the ZODB or whatever, but most users will just write code on top of the resulting libraries and ignore the implementation details.  File: python.info, Node: Multiple Inheritance The Diamond Rule, Next: Attribute Access, Prev: Descriptors, Up: PEPs 252 and 253 Type and Class Changes 1.15.2.3 Multiple Inheritance: The Diamond Rule ............................................... Multiple inheritance has also been made more useful through changing the rules under which names are resolved. Consider this set of classes (diagram taken from PEP 253(1) by Guido van Rossum): class A: ^ ^ def save(self): ... / \ / \ / \ / \ class B class C: ^ ^ def save(self): ... \ / \ / \ / \ / class D The lookup rule for classic classes is simple but not very smart; the base classes are searched depth-first, going from left to right. A reference to ‘D.save()’ will search the classes ‘D’, ‘B’, and then ‘A’, where ‘save()’ would be found and returned. ‘C.save()’ would never be found at all. This is bad, because if ‘C’’s ‘save()’ method is saving some internal state specific to ‘C’, not calling it will result in that state never getting saved. New-style classes follow a different algorithm that’s a bit more complicated to explain, but does the right thing in this situation. (Note that Python 2.3 changes this algorithm to one that produces the same results in most cases, but produces more useful results for really complicated inheritance graphs.) 1. List all the base classes, following the classic lookup rule and include a class multiple times if it’s visited repeatedly. In the above example, the list of visited classes is [‘D’, ‘B’, ‘A’, ‘C’, ‘A’]. 2. Scan the list for duplicated classes. If any are found, remove all but one occurrence, leaving the `last' one in the list. In the above example, the list becomes [‘D’, ‘B’, ‘C’, ‘A’] after dropping duplicates. Following this rule, referring to ‘D.save()’ will return ‘C.save()’, which is the behaviour we’re after. This lookup rule is the same as the one followed by Common Lisp. A new built-in function, *note super(): 4e2, provides a way to get at a class’s superclasses without having to reimplement Python’s algorithm. The most commonly used form will be ‘super(class, obj)’, which returns a bound superclass object (not the actual class object). This form will be used in methods to call a method in the superclass; for example, ‘D’’s ‘save()’ method would look like this: class D (B,C): def save (self): # Call superclass .save() super(D, self).save() # Save D's private information here ... *note super(): 4e2. can also return unbound superclass objects when called as ‘super(class)’ or ‘super(class1, class2)’, but this probably won’t often be useful. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0253  File: python.info, Node: Attribute Access, Next: Related Links, Prev: Multiple Inheritance The Diamond Rule, Up: PEPs 252 and 253 Type and Class Changes 1.15.2.4 Attribute Access ......................... A fair number of sophisticated Python classes define hooks for attribute access using *note __getattr__(): 31a.; most commonly this is done for convenience, to make code more readable by automatically mapping an attribute access such as ‘obj.parent’ into a method call such as ‘obj.get_parent’. Python 2.2 adds some new ways of controlling attribute access. First, ‘__getattr__(attr_name)’ is still supported by new-style classes, and nothing about it has changed. As before, it will be called when an attempt is made to access ‘obj.foo’ and no attribute named ‘foo’ is found in the instance’s dictionary. New-style classes also support a new method, ‘__getattribute__(attr_name)’. The difference between the two methods is that *note __getattribute__(): 449. is `always' called whenever any attribute is accessed, while the old *note __getattr__(): 31a. is only called if ‘foo’ isn’t found in the instance’s dictionary. However, Python 2.2’s support for `properties' will often be a simpler way to trap attribute references. Writing a *note __getattr__(): 31a. method is complicated because to avoid recursion you can’t use regular attribute accesses inside them, and instead have to mess around with the contents of *note __dict__: 4fc. *note __getattr__(): 31a. methods also end up being called by Python when it checks for other methods such as *note __repr__(): 33e. or ‘__coerce__()’, and so have to be written with this in mind. Finally, calling a function on every attribute access results in a sizable performance loss. *note property: 1d7. is a new built-in type that packages up three functions that get, set, or delete an attribute, and a docstring. For example, if you want to define a ‘size’ attribute that’s computed, but also settable, you could write: class C(object): def get_size (self): result = ... computation ... return result def set_size (self, size): ... compute something based on the size and set internal state appropriately ... # Define a property. The 'delete this attribute' # method is defined as None, so the attribute # can't be deleted. size = property(get_size, set_size, None, "Storage size of this instance") That is certainly clearer and easier to write than a pair of *note __getattr__(): 31a./*note __setattr__(): e2c. methods that check for the ‘size’ attribute and handle it specially while retrieving all other attributes from the instance’s *note __dict__: 4fc. Accesses to ‘size’ are also the only ones which have to perform the work of calling a function, so references to other attributes run at their usual speed. Finally, it’s possible to constrain the list of attributes that can be referenced on an object using the new *note __slots__: e2d. class attribute. Python objects are usually very dynamic; at any time it’s possible to define a new attribute on an instance by just doing ‘obj.new_attr=1’. A new-style class can define a class attribute named *note __slots__: e2d. to limit the legal attributes to a particular set of names. An example will make this clear: >>> class C(object): ... __slots__ = ('template', 'name') ... >>> obj = C() >>> print obj.template None >>> obj.template = 'Test' >>> print obj.template Test >>> obj.newattr = None Traceback (most recent call last): File "", line 1, in ? AttributeError: 'C' object has no attribute 'newattr' Note how you get an *note AttributeError: 39b. on the attempt to assign to an attribute not listed in *note __slots__: e2d.  File: python.info, Node: Related Links, Prev: Attribute Access, Up: PEPs 252 and 253 Type and Class Changes 1.15.2.5 Related Links ...................... This section has just been a quick overview of the new features, giving enough of an explanation to start you programming, but many details have been simplified or ignored. Where should you go to get a more complete picture? ‘https://docs.python.org/dev/howto/descriptor.html’ is a lengthy tutorial introduction to the descriptor features, written by Guido van Rossum. If my description has whetted your appetite, go read this tutorial next, because it goes into much more detail about the new features while still remaining quite easy to read. Next, there are two relevant PEPs, PEP 252(1) and PEP 253(2). PEP 252(3) is titled “Making Types Look More Like Classes”, and covers the descriptor API. PEP 253(4) is titled “Subtyping Built-in Types”, and describes the changes to type objects that make it possible to subtype built-in objects. PEP 253(5) is the more complicated PEP of the two, and at a few points the necessary explanations of types and meta-types may cause your head to explode. Both PEPs were written and implemented by Guido van Rossum, with substantial assistance from the rest of the Zope Corp. team. Finally, there’s the ultimate authority: the source code. Most of the machinery for the type handling is in ‘Objects/typeobject.c’, but you should only resort to it after all other avenues have been exhausted, including posting a question to python-list or python-dev. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0252 (2) https://www.python.org/dev/peps/pep-0253 (3) https://www.python.org/dev/peps/pep-0252 (4) https://www.python.org/dev/peps/pep-0253 (5) https://www.python.org/dev/peps/pep-0253  File: python.info, Node: PEP 234 Iterators, Next: PEP 255 Simple Generators<2>, Prev: PEPs 252 and 253 Type and Class Changes, Up: What’s New in Python 2 2 1.15.3 PEP 234: Iterators ------------------------- Another significant addition to 2.2 is an iteration interface at both the C and Python levels. Objects can define how they can be looped over by callers. In Python versions up to 2.1, the usual way to make ‘for item in obj’ work is to define a *note __getitem__(): 27c. method that looks something like this: def __getitem__(self, index): return *note __getitem__(): 27c. is more properly used to define an indexing operation on an object so that you can write ‘obj[5]’ to retrieve the sixth element. It’s a bit misleading when you’re using this only to support *note for: c30. loops. Consider some file-like object that wants to be looped over; the `index' parameter is essentially meaningless, as the class probably assumes that a series of *note __getitem__(): 27c. calls will be made with `index' incrementing by one each time. In other words, the presence of the *note __getitem__(): 27c. method doesn’t mean that using ‘file[5]’ to randomly access the sixth element will work, though it really should. In Python 2.2, iteration can be implemented separately, and *note __getitem__(): 27c. methods can be limited to classes that really do support random access. The basic idea of iterators is simple. A new built-in function, ‘iter(obj)’ or ‘iter(C, sentinel)’, is used to get an iterator. ‘iter(obj)’ returns an iterator for the object `obj', while ‘iter(C, sentinel)’ returns an iterator that will invoke the callable object `C' until it returns `sentinel' to signal that the iterator is done. Python classes can define an *note __iter__(): 50f. method, which should create and return a new iterator for the object; if the object is its own iterator, this method can just return ‘self’. In particular, iterators will usually be their own iterators. Extension types implemented in C can implement a *note tp_iter: e30. function in order to return an iterator, and extension types that want to behave as iterators can define a *note tp_iternext: e31. function. So, after all this, what do iterators actually do? They have one required method, *note next(): 682, which takes no arguments and returns the next value. When there are no more values to be returned, calling *note next(): 682. should raise the *note StopIteration: 486. exception. >>> L = [1,2,3] >>> i = iter(L) >>> print i >>> i.next() 1 >>> i.next() 2 >>> i.next() 3 >>> i.next() Traceback (most recent call last): File "", line 1, in ? StopIteration >>> In 2.2, Python’s *note for: c30. statement no longer expects a sequence; it expects something for which *note iter(): d27. will return an iterator. For backward compatibility and convenience, an iterator is automatically constructed for sequences that don’t implement *note __iter__(): 50f. or a *note tp_iter: e30. slot, so ‘for i in [1,2,3]’ will still work. Wherever the Python interpreter loops over a sequence, it’s been changed to use the iterator protocol. This means you can do things like this: >>> L = [1,2,3] >>> i = iter(L) >>> a,b,c = i >>> a,b,c (1, 2, 3) Iterator support has been added to some of Python’s basic types. Calling *note iter(): d27. on a dictionary will return an iterator which loops over its keys: >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6, ... 'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12} >>> for key in m: print key, m[key] ... Mar 3 Feb 2 Aug 8 Sep 9 May 5 Jun 6 Jul 7 Jan 1 Apr 4 Nov 11 Dec 12 Oct 10 That’s just the default behaviour. If you want to iterate over keys, values, or key/value pairs, you can explicitly call the ‘iterkeys()’, ‘itervalues()’, or ‘iteritems()’ methods to get an appropriate iterator. In a minor related change, the *note in: 7a3. operator now works on dictionaries, so ‘key in dict’ is now equivalent to ‘dict.has_key(key)’. Files also provide an iterator, which calls the *note readline(): de. method until there are no more lines in the file. This means you can now read each line of a file using code like this: for line in file: # do something for each line ... Note that you can only go forward in an iterator; there’s no way to get the previous element, reset the iterator, or make a copy of it. An iterator object could provide such additional capabilities, but the iterator protocol only requires a *note next(): 682. method. See also ........ PEP 234(1) - Iterators Written by Ka-Ping Yee and GvR; implemented by the Python Labs crew, mostly by GvR and Tim Peters. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0234  File: python.info, Node: PEP 255 Simple Generators<2>, Next: PEP 237 Unifying Long Integers and Integers<2>, Prev: PEP 234 Iterators, Up: What’s New in Python 2 2 1.15.4 PEP 255: Simple Generators --------------------------------- Generators are another new feature, one that interacts with the introduction of iterators. You’re doubtless familiar with how function calls work in Python or C. When you call a function, it gets a private namespace where its local variables are created. When the function reaches a *note return: 190. statement, the local variables are destroyed and the resulting value is returned to the caller. A later call to the same function will get a fresh new set of local variables. But, what if the local variables weren’t thrown away on exiting a function? What if you could later resume the function where it left off? This is what generators provide; they can be thought of as resumable functions. Here’s the simplest example of a generator function: def generate_ints(N): for i in range(N): yield i A new keyword, *note yield: 18f, was introduced for generators. Any function containing a ‘yield’ statement is a generator function; this is detected by Python’s bytecode compiler which compiles the function specially as a result. Because a new keyword was introduced, generators must be explicitly enabled in a module by including a ‘from __future__ import generators’ statement near the top of the module’s source code. In Python 2.3 this statement will become unnecessary. When you call a generator function, it doesn’t return a single value; instead it returns a generator object that supports the iterator protocol. On executing the *note yield: 18f. statement, the generator outputs the value of ‘i’, similar to a *note return: 190. statement. The big difference between ‘yield’ and a ‘return’ statement is that on reaching a ‘yield’ the generator’s state of execution is suspended and local variables are preserved. On the next call to the generator’s ‘next()’ method, the function will resume executing immediately after the ‘yield’ statement. (For complicated reasons, the ‘yield’ statement isn’t allowed inside the ‘try’ block of a *note try: d72.…*note finally: 182. statement; read PEP 255(1) for a full explanation of the interaction between ‘yield’ and exceptions.) Here’s a sample usage of the ‘generate_ints()’ generator: >>> gen = generate_ints(3) >>> gen >>> gen.next() 0 >>> gen.next() 1 >>> gen.next() 2 >>> gen.next() Traceback (most recent call last): File "", line 1, in ? File "", line 2, in generate_ints StopIteration You could equally write ‘for i in generate_ints(5)’, or ‘a,b,c = generate_ints(3)’. Inside a generator function, the *note return: 190. statement can only be used without a value, and signals the end of the procession of values; afterwards the generator cannot return any further values. ‘return’ with a value, such as ‘return 5’, is a syntax error inside a generator function. The end of the generator’s results can also be indicated by raising *note StopIteration: 486. manually, or by just letting the flow of execution fall off the bottom of the function. You could achieve the effect of generators manually by writing your own class and storing all the local variables of the generator as instance variables. For example, returning a list of integers could be done by setting ‘self.count’ to 0, and having the *note next(): 682. method increment ‘self.count’ and return it. However, for a moderately complicated generator, writing a corresponding class would be much messier. ‘Lib/test/test_generators.py’ contains a number of more interesting examples. The simplest one implements an in-order traversal of a tree using generators recursively. # A recursive generator that generates Tree leaves in in-order. def inorder(t): if t: for x in inorder(t.left): yield x yield t.label for x in inorder(t.right): yield x Two other examples in ‘Lib/test/test_generators.py’ produce solutions for the N-Queens problem (placing $N$ queens on an $NxN$ chess board so that no queen threatens another) and the Knight’s Tour (a route that takes a knight to every square of an $NxN$ chessboard without visiting any square twice). The idea of generators comes from other programming languages, especially Icon (‘https://www.cs.arizona.edu/icon/’), where the idea of generators is central. In Icon, every expression and function call behaves like a generator. One example from “An Overview of the Icon Programming Language” at ‘https://www.cs.arizona.edu/icon/docs/ipd266.htm’ gives an idea of what this looks like: sentence := "Store it in the neighboring harbor" if (i := find("or", sentence)) > 5 then write(i) In Icon the ‘find()’ function returns the indexes at which the substring “or” is found: 3, 23, 33. In the *note if: de7. statement, ‘i’ is first assigned a value of 3, but 3 is less than 5, so the comparison fails, and Icon retries it with the second value of 23. 23 is greater than 5, so the comparison now succeeds, and the code prints the value 23 to the screen. Python doesn’t go nearly as far as Icon in adopting generators as a central concept. Generators are considered a new part of the core Python language, but learning or using them isn’t compulsory; if they don’t solve any problems that you have, feel free to ignore them. One novel feature of Python’s interface as compared to Icon’s is that a generator’s state is represented as a concrete object (the iterator) that can be passed around to other functions or stored in a data structure. See also ........ PEP 255(2) - Simple Generators Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland. Implemented mostly by Neil Schemenauer and Tim Peters, with other fixes from the Python Labs crew. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0255 (2) https://www.python.org/dev/peps/pep-0255  File: python.info, Node: PEP 237 Unifying Long Integers and Integers<2>, Next: PEP 238 Changing the Division Operator, Prev: PEP 255 Simple Generators<2>, Up: What’s New in Python 2 2 1.15.5 PEP 237: Unifying Long Integers and Integers --------------------------------------------------- In recent versions, the distinction between regular integers, which are 32-bit values on most machines, and long integers, which can be of arbitrary size, was becoming an annoyance. For example, on platforms that support files larger than ‘2**32’ bytes, the ‘tell()’ method of file objects has to return a long integer. However, there were various bits of Python that expected plain integers and would raise an error if a long integer was provided instead. For example, in Python 1.5, only regular integers could be used as a slice index, and ‘'abc'[1L:]’ would raise a *note TypeError: 192. exception with the message ‘slice index must be int’. Python 2.2 will shift values from short to long integers as required. The ‘L’ suffix is no longer needed to indicate a long integer literal, as now the compiler will choose the appropriate type. (Using the ‘L’ suffix will be discouraged in future 2.x versions of Python, triggering a warning in Python 2.4, and probably dropped in Python 3.0.) Many operations that used to raise an *note OverflowError: 960. will now return a long integer as their result. For example: >>> 1234567890123 1234567890123L >>> 2 ** 64 18446744073709551616L In most cases, integers and long integers will now be treated identically. You can still distinguish them with the *note type(): 608. built-in function, but that’s rarely needed. See also ........ PEP 237(1) - Unifying Long Integers and Integers Written by Moshe Zadka and Guido van Rossum. Implemented mostly by Guido van Rossum. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0237  File: python.info, Node: PEP 238 Changing the Division Operator, Next: Unicode Changes, Prev: PEP 237 Unifying Long Integers and Integers<2>, Up: What’s New in Python 2 2 1.15.6 PEP 238: Changing the Division Operator ---------------------------------------------- The most controversial change in Python 2.2 heralds the start of an effort to fix an old design flaw that’s been in Python from the beginning. Currently Python’s division operator, ‘/’, behaves like C’s division operator when presented with two integer arguments: it returns an integer result that’s truncated down when there would be a fractional part. For example, ‘3/2’ is 1, not 1.5, and ‘(-1)/2’ is -1, not -0.5. This means that the results of division can vary unexpectedly depending on the type of the two operands and because Python is dynamically typed, it can be difficult to determine the possible types of the operands. (The controversy is over whether this is `really' a design flaw, and whether it’s worth breaking existing code to fix this. It’s caused endless discussions on python-dev, and in July 2001 erupted into a storm of acidly sarcastic postings on ‘comp.lang.python’. I won’t argue for either side here and will stick to describing what’s implemented in 2.2. Read PEP 238(1) for a summary of arguments and counter-arguments.) Because this change might break code, it’s being introduced very gradually. Python 2.2 begins the transition, but the switch won’t be complete until Python 3.0. First, I’ll borrow some terminology from PEP 238(2). “True division” is the division that most non-programmers are familiar with: 3/2 is 1.5, 1/4 is 0.25, and so forth. “Floor division” is what Python’s ‘/’ operator currently does when given integer operands; the result is the floor of the value returned by true division. “Classic division” is the current mixed behaviour of ‘/’; it returns the result of floor division when the operands are integers, and returns the result of true division when one of the operands is a floating-point number. Here are the changes 2.2 introduces: * A new operator, ‘//’, is the floor division operator. (Yes, we know it looks like C++’s comment symbol.) ‘//’ `always' performs floor division no matter what the types of its operands are, so ‘1 // 2’ is 0 and ‘1.0 // 2.0’ is also 0.0. ‘//’ is always available in Python 2.2; you don’t need to enable it using a ‘__future__’ statement. * By including a ‘from __future__ import division’ in a module, the ‘/’ operator will be changed to return the result of true division, so ‘1/2’ is 0.5. Without the ‘__future__’ statement, ‘/’ still means classic division. The default meaning of ‘/’ will not change until Python 3.0. * Classes can define methods called *note __truediv__(): 786. and *note __floordiv__(): e35. to overload the two division operators. At the C level, there are also slots in the *note PyNumberMethods: d81. structure so extension types can define the two operators. * Python 2.2 supports some command-line arguments for testing whether code will work with the changed division semantics. Running python with ‘-Q warn’ will cause a warning to be issued whenever division is applied to two integers. You can use this to find code that’s affected by the change and fix it. By default, Python 2.2 will simply perform classic division without a warning; the warning will be turned on by default in Python 2.3. See also ........ PEP 238(3) - Changing the Division Operator Written by Moshe Zadka and Guido van Rossum. Implemented by Guido van Rossum.. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0238 (2) https://www.python.org/dev/peps/pep-0238 (3) https://www.python.org/dev/peps/pep-0238  File: python.info, Node: Unicode Changes, Next: PEP 227 Nested Scopes, Prev: PEP 238 Changing the Division Operator, Up: What’s New in Python 2 2 1.15.7 Unicode Changes ---------------------- Python’s Unicode support has been enhanced a bit in 2.2. Unicode strings are usually stored as UCS-2, as 16-bit unsigned integers. Python 2.2 can also be compiled to use UCS-4, 32-bit unsigned integers, as its internal encoding by supplying ‘--enable-unicode=ucs4’ to the configure script. (It’s also possible to specify ‘--disable-unicode’ to completely disable Unicode support.) When built to use UCS-4 (a “wide Python”), the interpreter can natively handle Unicode characters from U+000000 to U+110000, so the range of legal values for the ‘unichr()’ function is expanded accordingly. Using an interpreter compiled to use UCS-2 (a “narrow Python”), values greater than 65535 will still cause ‘unichr()’ to raise a *note ValueError: 1fb. exception. This is all described in PEP 261(1), “Support for ‘wide’ Unicode characters”; consult it for further details. Another change is simpler to explain. Since their introduction, Unicode strings have supported an ‘encode()’ method to convert the string to a selected encoding such as UTF-8 or Latin-1. A symmetric ‘decode([*encoding*])’ method has been added to 8-bit strings (though not to Unicode strings) in 2.2. ‘decode()’ assumes that the string is in the specified encoding and decodes it, returning whatever is returned by the codec. Using this new feature, codecs have been added for tasks not directly related to Unicode. For example, codecs have been added for uu-encoding, MIME’s base64 encoding, and compression with the *note zlib: 144. module: >>> s = """Here is a lengthy piece of redundant, overly verbose, ... and repetitive text. ... """ >>> data = s.encode('zlib') >>> data 'x\x9c\r\xc9\xc1\r\x80 \x10\x04\xc0?Ul...' >>> data.decode('zlib') 'Here is a lengthy piece of redundant, overly verbose,\nand repetitive text.\n' >>> print s.encode('uu') begin 666 M2&5R92!I=F5R8F]S92P*86YD(')E<&5T:71I=F4@=&5X="X* end >>> "sheesh".encode('rot-13') 'furrfu' To convert a class instance to Unicode, a ‘__unicode__()’ method can be defined by a class, analogous to *note __str__(): e37. ‘encode()’, ‘decode()’, and ‘__unicode__()’ were implemented by Marc-André Lemburg. The changes to support using UCS-4 internally were implemented by Fredrik Lundh and Martin von Löwis. See also ........ PEP 261(2) - Support for ‘wide’ Unicode characters Written by Paul Prescod. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0261 (2) https://www.python.org/dev/peps/pep-0261  File: python.info, Node: PEP 227 Nested Scopes, Next: New and Improved Modules<3>, Prev: Unicode Changes, Up: What’s New in Python 2 2 1.15.8 PEP 227: Nested Scopes ----------------------------- In Python 2.1, statically nested scopes were added as an optional feature, to be enabled by a ‘from __future__ import nested_scopes’ directive. In 2.2 nested scopes no longer need to be specially enabled, and are now always present. The rest of this section is a copy of the description of nested scopes from my “What’s New in Python 2.1” document; if you read it when 2.1 came out, you can skip the rest of this section. The largest change introduced in Python 2.1, and made complete in 2.2, is to Python’s scoping rules. In Python 2.0, at any given time there are at most three namespaces used to look up variable names: local, module-level, and the built-in namespace. This often surprised people because it didn’t match their intuitive expectations. For example, a nested recursive function definition doesn’t work: def f(): ... def g(value): ... return g(value-1) + 1 ... The function ‘g()’ will always raise a *note NameError: d7b. exception, because the binding of the name ‘g’ isn’t in either its local namespace or in the module-level namespace. This isn’t much of a problem in practice (how often do you recursively define interior functions like this?), but this also made using the *note lambda: c2f. expression clumsier, and this was a problem in practice. In code which uses ‘lambda’ you can often find local variables being copied by passing them as the default values of arguments. def find(self, name): "Return list of any entries equal to 'name'" L = filter(lambda x, name=name: x == name, self.list_attribute) return L The readability of Python code written in a strongly functional style suffers greatly as a result. The most significant change to Python 2.2 is that static scoping has been added to the language to fix this problem. As a first effect, the ‘name=name’ default argument is now unnecessary in the above example. Put simply, when a given variable name is not assigned a value within a function (by an assignment, or the *note def: dbe, *note class: c6a, or *note import: c1d. statements), references to the variable will be looked up in the local namespace of the enclosing scope. A more detailed explanation of the rules, and a dissection of the implementation, can be found in the PEP. This change may cause some compatibility problems for code where the same variable name is used both at the module level and as a local variable within a function that contains further function definitions. This seems rather unlikely though, since such code would have been pretty confusing to read in the first place. One side effect of the change is that the ‘from module import *’ and ‘exec’ statements have been made illegal inside a function scope under certain conditions. The Python reference manual has said all along that ‘from module import *’ is only legal at the top level of a module, but the CPython interpreter has never enforced this before. As part of the implementation of nested scopes, the compiler which turns Python source into bytecodes has to generate different code to access variables in a containing scope. ‘from module import *’ and ‘exec’ make it impossible for the compiler to figure this out, because they add names to the local namespace that are unknowable at compile time. Therefore, if a function contains function definitions or *note lambda: c2f. expressions with free variables, the compiler will flag this by raising a *note SyntaxError: 458. exception. To make the preceding explanation a bit clearer, here’s an example: x = 1 def f(): # The next line is a syntax error exec 'x=2' def g(): return x Line 4 containing the ‘exec’ statement is a syntax error, since ‘exec’ would define a new local variable named ‘x’ whose value should be accessed by ‘g()’. This shouldn’t be much of a limitation, since ‘exec’ is rarely used in most Python code (and when it is used, it’s often a sign of a poor design anyway). See also ........ PEP 227(1) - Statically Nested Scopes Written and implemented by Jeremy Hylton. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0227  File: python.info, Node: New and Improved Modules<3>, Next: Interpreter Changes and Fixes, Prev: PEP 227 Nested Scopes, Up: What’s New in Python 2 2 1.15.9 New and Improved Modules ------------------------------- * The ‘xmlrpclib’ module was contributed to the standard library by Fredrik Lundh, providing support for writing XML-RPC clients. XML-RPC is a simple remote procedure call protocol built on top of HTTP and XML. For example, the following snippet retrieves a list of RSS channels from the O’Reilly Network, and then lists the recent headlines for one channel: import xmlrpclib s = xmlrpclib.Server( 'http://www.oreillynet.com/meerkat/xml-rpc/server.php') channels = s.meerkat.getChannels() # channels is a list of dictionaries, like this: # [{'id': 4, 'title': 'Freshmeat Daily News'} # {'id': 190, 'title': '32Bits Online'}, # {'id': 4549, 'title': '3DGamers'}, ... ] # Get the items for one channel items = s.meerkat.getItems( {'channel': 4} ) # 'items' is another list of dictionaries, like this: # [{'link': 'http://freshmeat.net/releases/52719/', # 'description': 'A utility which converts HTML to XSL FO.', # 'title': 'html2fo 0.3 (Default)'}, ... ] The ‘SimpleXMLRPCServer’ module makes it easy to create straightforward XML-RPC servers. See ‘http://xmlrpc.scripting.com/’ for more information about XML-RPC. * The new *note hmac: 8f. module implements the HMAC algorithm described by RFC 2104(1). (Contributed by Gerhard Häring.) * Several functions that originally returned lengthy tuples now return pseudo-sequences that still behave like tuples but also have mnemonic attributes such as memberst_mtime or ‘tm_year’. The enhanced functions include *note stat(): f4, ‘fstat()’, ‘statvfs()’, and ‘fstatvfs()’ in the *note os: c4. module, and ‘localtime()’, ‘gmtime()’, and ‘strptime()’ in the *note time: 10a. module. For example, to obtain a file’s size using the old tuples, you’d end up writing something like ‘file_size = os.stat(filename)[stat.ST_SIZE]’, but now this can be written more clearly as ‘file_size = os.stat(filename).st_size’. The original patch for this feature was contributed by Nick Mathewson. * The Python profiler has been extensively reworked and various errors in its output have been corrected. (Contributed by Fred L. Drake, Jr. and Tim Peters.) * The *note socket: ef. module can be compiled to support IPv6; specify the ‘--enable-ipv6’ option to Python’s configure script. (Contributed by Jun-ichiro “itojun” Hagino.) * Two new format characters were added to the *note struct: f8. module for 64-bit integers on platforms that support the C ‘long long’ type. ‘q’ is for a signed 64-bit integer, and ‘Q’ is for an unsigned one. The value is returned in Python’s long integer type. (Contributed by Tim Peters.) * In the interpreter’s interactive mode, there’s a new built-in function *note help(): 572. that uses the *note pydoc: d9. module introduced in Python 2.1 to provide interactive help. ‘help(object)’ displays any available help text about `object'. *note help(): 572. with no argument puts you in an online help utility, where you can enter the names of functions, classes, or modules to read their help text. (Contributed by Guido van Rossum, using Ka-Ping Yee’s *note pydoc: d9. module.) * Various bugfixes and performance improvements have been made to the SRE engine underlying the *note re: dd. module. For example, the *note re.sub(): 47b. and *note re.split(): 3ca. functions have been rewritten in C. Another contributed patch speeds up certain Unicode character ranges by a factor of two, and a new ‘finditer()’ method that returns an iterator over all the non-overlapping matches in a given string. (SRE is maintained by Fredrik Lundh. The BIGCHARSET patch was contributed by Martin von Löwis.) * The *note smtplib: ed. module now supports RFC 2487(2), “Secure SMTP over TLS”, so it’s now possible to encrypt the SMTP traffic between a Python program and the mail transport agent being handed a message. *note smtplib: ed. also supports SMTP authentication. (Contributed by Gerhard Häring.) * The *note imaplib: 98. module, maintained by Piers Lauder, has support for several new extensions: the NAMESPACE extension defined in RFC 2342(3), SORT, GETACL and SETACL. (Contributed by Anthony Baxter and Michel Pelletier.) * The ‘rfc822’ module’s parsing of email addresses is now compliant with RFC 2822(4), an update to RFC 822(5). (The module’s name is `not' going to be changed to ‘rfc2822’.) A new package, *note email: 69, has also been added for parsing and generating e-mail messages. (Contributed by Barry Warsaw, and arising out of his work on Mailman.) * The *note difflib: 37. module now contains a new ‘Differ’ class for producing human-readable lists of changes (a “delta”) between two sequences of lines of text. There are also two generator functions, ‘ndiff()’ and ‘restore()’, which respectively return a delta from two sequences, or one of the original sequences from a delta. (Grunt work contributed by David Goodger, from ndiff.py code by Tim Peters who then did the generatorization.) * New constants ‘ascii_letters’, ‘ascii_lowercase’, and ‘ascii_uppercase’ were added to the *note string: f6. module. There were several modules in the standard library that used ‘string.letters’ to mean the ranges A-Za-z, but that assumption is incorrect when locales are in use, because ‘string.letters’ varies depending on the set of legal characters defined by the current locale. The buggy modules have all been fixed to use ‘ascii_letters’ instead. (Reported by an unknown person; fixed by Fred L. Drake, Jr.) * The *note mimetypes: b2. module now makes it easier to use alternative MIME-type databases by the addition of a ‘MimeTypes’ class, which takes a list of filenames to be parsed. (Contributed by Fred L. Drake, Jr.) * A ‘Timer’ class was added to the *note threading: 109. module that allows scheduling an activity to happen at some future time. (Contributed by Itamar Shtull-Trauring.) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2104.html (2) https://tools.ietf.org/html/rfc2487.html (3) https://tools.ietf.org/html/rfc2342.html (4) https://tools.ietf.org/html/rfc2822.html (5) https://tools.ietf.org/html/rfc822.html  File: python.info, Node: Interpreter Changes and Fixes, Next: Other Changes and Fixes<3>, Prev: New and Improved Modules<3>, Up: What’s New in Python 2 2 1.15.10 Interpreter Changes and Fixes ------------------------------------- Some of the changes only affect people who deal with the Python interpreter at the C level because they’re writing Python extension modules, embedding the interpreter, or just hacking on the interpreter itself. If you only write Python code, none of the changes described here will affect you very much. * Profiling and tracing functions can now be implemented in C, which can operate at much higher speeds than Python-based functions and should reduce the overhead of profiling and tracing. This will be of interest to authors of development environments for Python. Two new C functions were added to Python’s API, *note PyEval_SetProfile(): e3b. and *note PyEval_SetTrace(): e3c. The existing *note sys.setprofile(): e3d. and *note sys.settrace(): e3e. functions still exist, and have simply been changed to use the new C-level interface. (Contributed by Fred L. Drake, Jr.) * Another low-level API, primarily of interest to implementors of Python debuggers and development tools, was added. *note PyInterpreterState_Head(): e3f. and *note PyInterpreterState_Next(): e40. let a caller walk through all the existing interpreter objects; *note PyInterpreterState_ThreadHead(): e41. and *note PyThreadState_Next(): e42. allow looping over all the thread states for a given interpreter. (Contributed by David Beazley.) * The C-level interface to the garbage collector has been changed to make it easier to write extension types that support garbage collection and to debug misuses of the functions. Various functions have slightly different semantics, so a bunch of functions had to be renamed. Extensions that use the old API will still compile but will `not' participate in garbage collection, so updating them for 2.2 should be considered fairly high priority. To upgrade an extension module to the new API, perform the following steps: * Rename ‘Py_TPFLAGS_GC()’ to ‘PyTPFLAGS_HAVE_GC()’. * Use *note PyObject_GC_New(): 2d4. or *note PyObject_GC_NewVar(): 2d5. to allocate objects, and *note PyObject_GC_Del(): e43. to deallocate them. * Rename ‘PyObject_GC_Init()’ to *note PyObject_GC_Track(): e44. and ‘PyObject_GC_Fini()’ to *note PyObject_GC_UnTrack(): e45. * Remove ‘PyGC_HEAD_SIZE()’ from object size calculations. * Remove calls to ‘PyObject_AS_GC()’ and ‘PyObject_FROM_GC()’. * A new ‘et’ format sequence was added to *note PyArg_ParseTuple(): 26a.; ‘et’ takes both a parameter and an encoding name, and converts the parameter to the given encoding if the parameter turns out to be a Unicode string, or leaves it alone if it’s an 8-bit string, assuming it to already be in the desired encoding. This differs from the ‘es’ format character, which assumes that 8-bit strings are in Python’s default ASCII encoding and converts them to the specified new encoding. (Contributed by M.-A. Lemburg, and used for the MBCS support on Windows described in the following section.) * A different argument parsing function, *note PyArg_UnpackTuple(): e46, has been added that’s simpler and presumably faster. Instead of specifying a format string, the caller simply gives the minimum and maximum number of arguments expected, and a set of pointers to *note PyObject*: 4ba. variables that will be filled in with argument values. * Two new flags *note METH_NOARGS: e18. and *note METH_O: e47. are available in method definition tables to simplify implementation of methods with no arguments or a single untyped argument. Calling such methods is more efficient than calling a corresponding method that uses *note METH_VARARGS: e48. Also, the old ‘METH_OLDARGS’ style of writing C methods is now officially deprecated. * Two new wrapper functions, *note PyOS_snprintf(): e49. and *note PyOS_vsnprintf(): e4a. were added to provide cross-platform implementations for the relatively new ‘snprintf()’ and ‘vsnprintf()’ C lib APIs. In contrast to the standard ‘sprintf()’ and ‘vsprintf()’ functions, the Python versions check the bounds of the buffer used to protect against buffer overruns. (Contributed by M.-A. Lemburg.) * The *note _PyTuple_Resize(): e4b. function has lost an unused parameter, so now it takes 2 parameters instead of 3. The third argument was never used, and can simply be discarded when porting code from earlier versions to Python 2.2.  File: python.info, Node: Other Changes and Fixes<3>, Next: Acknowledgements<6>, Prev: Interpreter Changes and Fixes, Up: What’s New in Python 2 2 1.15.11 Other Changes and Fixes ------------------------------- As usual there were a bunch of other improvements and bugfixes scattered throughout the source tree. A search through the CVS change logs finds there were 527 patches applied and 683 bugs fixed between Python 2.1 and 2.2; 2.2.1 applied 139 patches and fixed 143 bugs; 2.2.2 applied 106 patches and fixed 82 bugs. These figures are likely to be underestimates. Some of the more notable changes are: * The code for the MacOS port for Python, maintained by Jack Jansen, is now kept in the main Python CVS tree, and many changes have been made to support MacOS X. The most significant change is the ability to build Python as a framework, enabled by supplying the ‘--enable-framework’ option to the configure script when compiling Python. According to Jack Jansen, “This installs a self-contained Python installation plus the OS X framework “glue” into ‘/Library/Frameworks/Python.framework’ (or another location of choice). For now there is little immediate added benefit to this (actually, there is the disadvantage that you have to change your PATH to be able to find Python), but it is the basis for creating a full-blown Python application, porting the MacPython IDE, possibly using Python as a standard OSA scripting language and much more.” Most of the MacPython toolbox modules, which interface to MacOS APIs such as windowing, QuickTime, scripting, etc. have been ported to OS X, but they’ve been left commented out in ‘setup.py’. People who want to experiment with these modules can uncomment them manually. * Keyword arguments passed to built-in functions that don’t take them now cause a *note TypeError: 192. exception to be raised, with the message “`function' takes no keyword arguments”. * Weak references, added in Python 2.1 as an extension module, are now part of the core because they’re used in the implementation of new-style classes. The *note ReferenceError: e4d. exception has therefore moved from the *note weakref: 128. module to become a built-in exception. * A new script, ‘Tools/scripts/cleanfuture.py’ by Tim Peters, automatically removes obsolete ‘__future__’ statements from Python source code. * An additional `flags' argument has been added to the built-in function *note compile(): 1b4, so the behaviour of ‘__future__’ statements can now be correctly observed in simulated shells, such as those presented by IDLE and other development environments. This is described in PEP 264(1). (Contributed by Michael Hudson.) * The new license introduced with Python 1.6 wasn’t GPL-compatible. This is fixed by some minor textual changes to the 2.2 license, so it’s now legal to embed Python inside a GPLed program again. Note that Python itself is not GPLed, but instead is under a license that’s essentially equivalent to the BSD license, same as it always was. The license changes were also applied to the Python 2.0.1 and 2.1.1 releases. * When presented with a Unicode filename on Windows, Python will now convert it to an MBCS encoded string, as used by the Microsoft file APIs. As MBCS is explicitly used by the file APIs, Python’s choice of ASCII as the default encoding turns out to be an annoyance. On Unix, the locale’s character set is used if ‘locale.nl_langinfo(CODESET)’ is available. (Windows support was contributed by Mark Hammond with assistance from Marc-André Lemburg. Unix support was added by Martin von Löwis.) * Large file support is now enabled on Windows. (Contributed by Tim Peters.) * The ‘Tools/scripts/ftpmirror.py’ script now parses a ‘.netrc’ file, if you have one. (Contributed by Mike Romberg.) * Some features of the object returned by the ‘xrange()’ function are now deprecated, and trigger warnings when they’re accessed; they’ll disappear in Python 2.3. ‘xrange’ objects tried to pretend they were full sequence types by supporting slicing, sequence multiplication, and the *note in: 7a3. operator, but these features were rarely used and therefore buggy. The ‘tolist()’ method and the ‘start’, ‘stop’, and ‘step’ attributes are also being deprecated. At the C level, the fourth argument to the ‘PyRange_New()’ function, ‘repeat’, has also been deprecated. * There were a bunch of patches to the dictionary implementation, mostly to fix potential core dumps if a dictionary contains objects that sneakily changed their hash value, or mutated the dictionary they were contained in. For a while python-dev fell into a gentle rhythm of Michael Hudson finding a case that dumped core, Tim Peters fixing the bug, Michael finding another case, and round and round it went. * On Windows, Python can now be compiled with Borland C thanks to a number of patches contributed by Stephen Hansen, though the result isn’t fully functional yet. (But this `is' progress…) * Another Windows enhancement: Wise Solutions generously offered PythonLabs use of their InstallerMaster 8.1 system. Earlier PythonLabs Windows installers used Wise 5.0a, which was beginning to show its age. (Packaged up by Tim Peters.) * Files ending in ‘.pyw’ can now be imported on Windows. ‘.pyw’ is a Windows-only thing, used to indicate that a script needs to be run using PYTHONW.EXE instead of PYTHON.EXE in order to prevent a DOS console from popping up to display the output. This patch makes it possible to import such scripts, in case they’re also usable as modules. (Implemented by David Bolen.) * On platforms where Python uses the C ‘dlopen()’ function to load extension modules, it’s now possible to set the flags used by ‘dlopen()’ using the *note sys.getdlopenflags(): e4e. and *note sys.setdlopenflags(): a66. functions. (Contributed by Bram Stolk.) * The *note pow(): 19a. built-in function no longer supports 3 arguments when floating-point numbers are supplied. ‘pow(x, y, z)’ returns ‘(x**y) % z’, but this is never useful for floating point numbers, and the final result varies unpredictably depending on the platform. A call such as ‘pow(2.0, 8.0, 7.0)’ will now raise a *note TypeError: 192. exception. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0264  File: python.info, Node: Acknowledgements<6>, Prev: Other Changes and Fixes<3>, Up: What’s New in Python 2 2 1.15.12 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Fred Bremmer, Keith Briggs, Andrew Dalke, Fred L. Drake, Jr., Carel Fellinger, David Goodger, Mark Hammond, Stephen Hansen, Michael Hudson, Jack Jansen, Marc-André Lemburg, Martin von Löwis, Fredrik Lundh, Michael McLay, Nick Mathewson, Paul Moore, Gustavo Niemeyer, Don O’Donnell, Joonas Paalasma, Tim Peters, Jens Quade, Tom Reinhardt, Neil Schemenauer, Guido van Rossum, Greg Ward, Edward Welbourne.  File: python.info, Node: What’s New in Python 2 1, Next: What’s New in Python 2 0, Prev: What’s New in Python 2 2, Up: What’s New in Python 1.16 What’s New in Python 2.1 ============================= Author: A.M. Kuchling * Menu: * Introduction: Introduction<2>. * PEP 227; Nested Scopes: PEP 227 Nested Scopes<2>. * PEP 236; __future__ Directives: PEP 236 __future__ Directives. * PEP 207; Rich Comparisons: PEP 207 Rich Comparisons. * PEP 230; Warning Framework: PEP 230 Warning Framework. * PEP 229; New Build System: PEP 229 New Build System. * PEP 205; Weak References: PEP 205 Weak References. * PEP 232; Function Attributes: PEP 232 Function Attributes. * PEP 235; Importing Modules on Case-Insensitive Platforms: PEP 235 Importing Modules on Case-Insensitive Platforms. * PEP 217; Interactive Display Hook: PEP 217 Interactive Display Hook. * PEP 208; New Coercion Model: PEP 208 New Coercion Model. * PEP 241; Metadata in Python Packages: PEP 241 Metadata in Python Packages. * New and Improved Modules: New and Improved Modules<4>. * Other Changes and Fixes: Other Changes and Fixes<4>. * Acknowledgements: Acknowledgements<7>.  File: python.info, Node: Introduction<2>, Next: PEP 227 Nested Scopes<2>, Up: What’s New in Python 2 1 1.16.1 Introduction ------------------- This article explains the new features in Python 2.1. While there aren’t as many changes in 2.1 as there were in Python 2.0, there are still some pleasant surprises in store. 2.1 is the first release to be steered through the use of Python Enhancement Proposals, or PEPs, so most of the sizable changes have accompanying PEPs that provide more complete documentation and a design rationale for the change. This article doesn’t attempt to document the new features completely, but simply provides an overview of the new features for Python programmers. Refer to the Python 2.1 documentation, or to the specific PEP, for more details about any new feature that particularly interests you. One recent goal of the Python development team has been to accelerate the pace of new releases, with a new release coming every 6 to 9 months. 2.1 is the first release to come out at this faster pace, with the first alpha appearing in January, 3 months after the final version of 2.0 was released. The final release of Python 2.1 was made on April 17, 2001.  File: python.info, Node: PEP 227 Nested Scopes<2>, Next: PEP 236 __future__ Directives, Prev: Introduction<2>, Up: What’s New in Python 2 1 1.16.2 PEP 227: Nested Scopes ----------------------------- The largest change in Python 2.1 is to Python’s scoping rules. In Python 2.0, at any given time there are at most three namespaces used to look up variable names: local, module-level, and the built-in namespace. This often surprised people because it didn’t match their intuitive expectations. For example, a nested recursive function definition doesn’t work: def f(): ... def g(value): ... return g(value-1) + 1 ... The function ‘g()’ will always raise a *note NameError: d7b. exception, because the binding of the name ‘g’ isn’t in either its local namespace or in the module-level namespace. This isn’t much of a problem in practice (how often do you recursively define interior functions like this?), but this also made using the *note lambda: c2f. expression clumsier, and this was a problem in practice. In code which uses *note lambda: c2f. you can often find local variables being copied by passing them as the default values of arguments. def find(self, name): "Return list of any entries equal to 'name'" L = filter(lambda x, name=name: x == name, self.list_attribute) return L The readability of Python code written in a strongly functional style suffers greatly as a result. The most significant change to Python 2.1 is that static scoping has been added to the language to fix this problem. As a first effect, the ‘name=name’ default argument is now unnecessary in the above example. Put simply, when a given variable name is not assigned a value within a function (by an assignment, or the *note def: dbe, *note class: c6a, or *note import: c1d. statements), references to the variable will be looked up in the local namespace of the enclosing scope. A more detailed explanation of the rules, and a dissection of the implementation, can be found in the PEP. This change may cause some compatibility problems for code where the same variable name is used both at the module level and as a local variable within a function that contains further function definitions. This seems rather unlikely though, since such code would have been pretty confusing to read in the first place. One side effect of the change is that the ‘from module import *’ and ‘exec’ statements have been made illegal inside a function scope under certain conditions. The Python reference manual has said all along that ‘from module import *’ is only legal at the top level of a module, but the CPython interpreter has never enforced this before. As part of the implementation of nested scopes, the compiler which turns Python source into bytecodes has to generate different code to access variables in a containing scope. ‘from module import *’ and ‘exec’ make it impossible for the compiler to figure this out, because they add names to the local namespace that are unknowable at compile time. Therefore, if a function contains function definitions or *note lambda: c2f. expressions with free variables, the compiler will flag this by raising a *note SyntaxError: 458. exception. To make the preceding explanation a bit clearer, here’s an example: x = 1 def f(): # The next line is a syntax error exec 'x=2' def g(): return x Line 4 containing the ‘exec’ statement is a syntax error, since ‘exec’ would define a new local variable named ‘x’ whose value should be accessed by ‘g()’. This shouldn’t be much of a limitation, since ‘exec’ is rarely used in most Python code (and when it is used, it’s often a sign of a poor design anyway). Compatibility concerns have led to nested scopes being introduced gradually; in Python 2.1, they aren’t enabled by default, but can be turned on within a module by using a future statement as described in PEP 236(1). (See the following section for further discussion of PEP 236(2).) In Python 2.2, nested scopes will become the default and there will be no way to turn them off, but users will have had all of 2.1’s lifetime to fix any breakage resulting from their introduction. See also ........ PEP 227(3) - Statically Nested Scopes Written and implemented by Jeremy Hylton. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0236 (2) https://www.python.org/dev/peps/pep-0236 (3) https://www.python.org/dev/peps/pep-0227  File: python.info, Node: PEP 236 __future__ Directives, Next: PEP 207 Rich Comparisons, Prev: PEP 227 Nested Scopes<2>, Up: What’s New in Python 2 1 1.16.3 PEP 236: __future__ Directives ------------------------------------- The reaction to nested scopes was widespread concern about the dangers of breaking code with the 2.1 release, and it was strong enough to make the Pythoneers take a more conservative approach. This approach consists of introducing a convention for enabling optional functionality in release N that will become compulsory in release N+1. The syntax uses a ‘from...import’ statement using the reserved module name *note __future__: 0. Nested scopes can be enabled by the following statement: from __future__ import nested_scopes While it looks like a normal *note import: c1d. statement, it’s not; there are strict rules on where such a future statement can be put. They can only be at the top of a module, and must precede any Python code or regular ‘import’ statements. This is because such statements can affect how the Python bytecode compiler parses code and generates bytecode, so they must precede any statement that will result in bytecodes being produced. See also ........ PEP 236(1) - Back to the *note __future__: 0. Written by Tim Peters, and primarily implemented by Jeremy Hylton. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0236  File: python.info, Node: PEP 207 Rich Comparisons, Next: PEP 230 Warning Framework, Prev: PEP 236 __future__ Directives, Up: What’s New in Python 2 1 1.16.4 PEP 207: Rich Comparisons -------------------------------- In earlier versions, Python’s support for implementing comparisons on user-defined classes and extension types was quite simple. Classes could implement a ‘__cmp__()’ method that was given two instances of a class, and could only return 0 if they were equal or +1 or -1 if they weren’t; the method couldn’t raise an exception or return anything other than a Boolean value. Users of Numeric Python often found this model too weak and restrictive, because in the number-crunching programs that numeric Python is used for, it would be more useful to be able to perform elementwise comparisons of two matrices, returning a matrix containing the results of a given comparison for each element. If the two matrices are of different sizes, then the compare has to be able to raise an exception to signal the error. In Python 2.1, rich comparisons were added in order to support this need. Python classes can now individually overload each of the ‘<’, ‘<=’, ‘>’, ‘>=’, ‘==’, and ‘!=’ operations. The new magic method names are: Operation Method name ------------------------------------- ‘<’ *note __lt__(): c34. ‘<=’ *note __le__(): ca0. ‘>’ *note __gt__(): ca1. ‘>=’ *note __ge__(): ca2. ‘==’ *note __eq__(): 33f. ‘!=’ *note __ne__(): e56. (The magic methods are named after the corresponding Fortran operators ‘.LT.’. ‘.LE.’, &c. Numeric programmers are almost certainly quite familiar with these names and will find them easy to remember.) Each of these magic methods is of the form ‘method(self, other)’, where ‘self’ will be the object on the left-hand side of the operator, while ‘other’ will be the object on the right-hand side. For example, the expression ‘A < B’ will cause ‘A.__lt__(B)’ to be called. Each of these magic methods can return anything at all: a Boolean, a matrix, a list, or any other Python object. Alternatively they can raise an exception if the comparison is impossible, inconsistent, or otherwise meaningless. The built-in ‘cmp(A,B)’ function can use the rich comparison machinery, and now accepts an optional argument specifying which comparison operation to use; this is given as one of the strings ‘"<"’, ‘"<="’, ‘">"’, ‘">="’, ‘"=="’, or ‘"!="’. If called without the optional third argument, ‘cmp()’ will only return -1, 0, or +1 as in previous versions of Python; otherwise it will call the appropriate method and can return any Python object. There are also corresponding changes of interest to C programmers; there’s a new slot ‘tp_richcmp’ in type objects and an API for performing a given rich comparison. I won’t cover the C API here, but will refer you to PEP 207(1), or to 2.1’s C API documentation, for the full list of related functions. See also ........ PEP 207(2) - Rich Comparisons Written by Guido van Rossum, heavily based on earlier work by David Ascher, and implemented by Guido van Rossum. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0207 (2) https://www.python.org/dev/peps/pep-0207  File: python.info, Node: PEP 230 Warning Framework, Next: PEP 229 New Build System, Prev: PEP 207 Rich Comparisons, Up: What’s New in Python 2 1 1.16.5 PEP 230: Warning Framework --------------------------------- Over its 10 years of existence, Python has accumulated a certain number of obsolete modules and features along the way. It’s difficult to know when a feature is safe to remove, since there’s no way of knowing how much code uses it — perhaps no programs depend on the feature, or perhaps many do. To enable removing old features in a more structured way, a warning framework was added. When the Python developers want to get rid of a feature, it will first trigger a warning in the next version of Python. The following Python version can then drop the feature, and users will have had a full release cycle to remove uses of the old feature. Python 2.1 adds the warning framework to be used in this scheme. It adds a *note warnings: 126. module that provide functions to issue warnings, and to filter out warnings that you don’t want to be displayed. Third-party modules can also use this framework to deprecate old features that they no longer wish to support. For example, in Python 2.1 the ‘regex’ module is deprecated, so importing it causes a warning to be printed: >>> import regex __main__:1: DeprecationWarning: the regex module is deprecated; please use the re module >>> Warnings can be issued by calling the *note warnings.warn(): e58. function: warnings.warn("feature X no longer supported") The first parameter is the warning message; an additional optional parameters can be used to specify a particular warning category. Filters can be added to disable certain warnings; a regular expression pattern can be applied to the message or to the module name in order to suppress a warning. For example, you may have a program that uses the ‘regex’ module and not want to spare the time to convert it to use the *note re: dd. module right now. The warning can be suppressed by calling import warnings warnings.filterwarnings(action = 'ignore', message='.*regex module is deprecated', category=DeprecationWarning, module = '__main__') This adds a filter that will apply only to warnings of the class *note DeprecationWarning: 278. triggered in the *note __main__: 1. module, and applies a regular expression to only match the message about the ‘regex’ module being deprecated, and will cause such warnings to be ignored. Warnings can also be printed only once, printed every time the offending code is executed, or turned into exceptions that will cause the program to stop (unless the exceptions are caught in the usual way, of course). Functions were also added to Python’s C API for issuing warnings; refer to PEP 230 or to Python’s API documentation for the details. See also ........ PEP 5(1) - Guidelines for Language Evolution Written by Paul Prescod, to specify procedures to be followed when removing old features from Python. The policy described in this PEP hasn’t been officially adopted, but the eventual policy probably won’t be too different from Prescod’s proposal. PEP 230(2) - Warning Framework Written and implemented by Guido van Rossum. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0005 (2) https://www.python.org/dev/peps/pep-0230  File: python.info, Node: PEP 229 New Build System, Next: PEP 205 Weak References, Prev: PEP 230 Warning Framework, Up: What’s New in Python 2 1 1.16.6 PEP 229: New Build System -------------------------------- When compiling Python, the user had to go in and edit the ‘Modules/Setup’ file in order to enable various additional modules; the default set is relatively small and limited to modules that compile on most Unix platforms. This means that on Unix platforms with many more features, most notably Linux, Python installations often don’t contain all useful modules they could. Python 2.0 added the Distutils, a set of modules for distributing and installing extensions. In Python 2.1, the Distutils are used to compile much of the standard library of extension modules, autodetecting which ones are supported on the current machine. It’s hoped that this will make Python installations easier and more featureful. Instead of having to edit the ‘Modules/Setup’ file in order to enable modules, a ‘setup.py’ script in the top directory of the Python source distribution is run at build time, and attempts to discover which modules can be enabled by examining the modules and header files on the system. If a module is configured in ‘Modules/Setup’, the ‘setup.py’ script won’t attempt to compile that module and will defer to the ‘Modules/Setup’ file’s contents. This provides a way to specific any strange command-line flags or libraries that are required for a specific platform. In another far-reaching change to the build mechanism, Neil Schemenauer restructured things so Python now uses a single makefile that isn’t recursive, instead of makefiles in the top directory and in each of the ‘Python/’, ‘Parser/’, ‘Objects/’, and ‘Modules/’ subdirectories. This makes building Python faster and also makes hacking the Makefiles clearer and simpler. See also ........ PEP 229(1) - Using Distutils to Build Python Written and implemented by A.M. Kuchling. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0229  File: python.info, Node: PEP 205 Weak References, Next: PEP 232 Function Attributes, Prev: PEP 229 New Build System, Up: What’s New in Python 2 1 1.16.7 PEP 205: Weak References ------------------------------- Weak references, available through the *note weakref: 128. module, are a minor but useful new data type in the Python programmer’s toolbox. Storing a reference to an object (say, in a dictionary or a list) has the side effect of keeping that object alive forever. There are a few specific cases where this behaviour is undesirable, object caches being the most common one, and another being circular references in data structures such as trees. For example, consider a memoizing function that caches the results of another function ‘f(x)’ by storing the function’s argument and its result in a dictionary: _cache = {} def memoize(x): if _cache.has_key(x): return _cache[x] retval = f(x) # Cache the returned object _cache[x] = retval return retval This version works for simple things such as integers, but it has a side effect; the ‘_cache’ dictionary holds a reference to the return values, so they’ll never be deallocated until the Python process exits and cleans up. This isn’t very noticeable for integers, but if ‘f()’ returns an object, or a data structure that takes up a lot of memory, this can be a problem. Weak references provide a way to implement a cache that won’t keep objects alive beyond their time. If an object is only accessible through weak references, the object will be deallocated and the weak references will now indicate that the object it referred to no longer exists. A weak reference to an object `obj' is created by calling ‘wr = weakref.ref(obj)’. The object being referred to is returned by calling the weak reference as if it were a function: ‘wr()’. It will return the referenced object, or ‘None’ if the object no longer exists. This makes it possible to write a ‘memoize()’ function whose cache doesn’t keep objects alive, by storing weak references in the cache. _cache = {} def memoize(x): if _cache.has_key(x): obj = _cache[x]() # If weak reference object still exists, # return it if obj is not None: return obj retval = f(x) # Cache a weak reference _cache[x] = weakref.ref(retval) return retval The *note weakref: 128. module also allows creating proxy objects which behave like weak references — an object referenced only by proxy objects is deallocated – but instead of requiring an explicit call to retrieve the object, the proxy transparently forwards all operations to the object as long as the object still exists. If the object is deallocated, attempting to use a proxy will cause a ‘weakref.ReferenceError’ exception to be raised. proxy = weakref.proxy(obj) proxy.attr # Equivalent to obj.attr proxy.meth() # Equivalent to obj.meth() del obj proxy.attr # raises weakref.ReferenceError See also ........ PEP 205(1) - Weak References Written and implemented by Fred L. Drake, Jr. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0205  File: python.info, Node: PEP 232 Function Attributes, Next: PEP 235 Importing Modules on Case-Insensitive Platforms, Prev: PEP 205 Weak References, Up: What’s New in Python 2 1 1.16.8 PEP 232: Function Attributes ----------------------------------- In Python 2.1, functions can now have arbitrary information attached to them. People were often using docstrings to hold information about functions and methods, because the ‘__doc__’ attribute was the only way of attaching any information to a function. For example, in the Zope Web application server, functions are marked as safe for public access by having a docstring, and in John Aycock’s SPARK parsing framework, docstrings hold parts of the BNF grammar to be parsed. This overloading is unfortunate, since docstrings are really intended to hold a function’s documentation; for example, it means you can’t properly document functions intended for private use in Zope. Arbitrary attributes can now be set and retrieved on functions using the regular Python syntax: def f(): pass f.publish = 1 f.secure = 1 f.grammar = "A ::= B (C D)*" The dictionary containing attributes can be accessed as the function’s *note __dict__: 4fc. Unlike the *note __dict__: 4fc. attribute of class instances, in functions you can actually assign a new dictionary to *note __dict__: 4fc, though the new value is restricted to a regular Python dictionary; you `can’t' be tricky and set it to a ‘UserDict’ instance, or any other random object that behaves like a mapping. See also ........ PEP 232(1) - Function Attributes Written and implemented by Barry Warsaw. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0232  File: python.info, Node: PEP 235 Importing Modules on Case-Insensitive Platforms, Next: PEP 217 Interactive Display Hook, Prev: PEP 232 Function Attributes, Up: What’s New in Python 2 1 1.16.9 PEP 235: Importing Modules on Case-Insensitive Platforms --------------------------------------------------------------- Some operating systems have filesystems that are case-insensitive, MacOS and Windows being the primary examples; on these systems, it’s impossible to distinguish the filenames ‘FILE.PY’ and ‘file.py’, even though they do store the file’s name in its original case (they’re case-preserving, too). In Python 2.1, the *note import: c1d. statement will work to simulate case-sensitivity on case-insensitive platforms. Python will now search for the first case-sensitive match by default, raising an *note ImportError: 334. if no such file is found, so ‘import file’ will not import a module named ‘FILE.PY’. Case-insensitive matching can be requested by setting the *note PYTHONCASEOK: e5d. environment variable before starting the Python interpreter.  File: python.info, Node: PEP 217 Interactive Display Hook, Next: PEP 208 New Coercion Model, Prev: PEP 235 Importing Modules on Case-Insensitive Platforms, Up: What’s New in Python 2 1 1.16.10 PEP 217: Interactive Display Hook ----------------------------------------- When using the Python interpreter interactively, the output of commands is displayed using the built-in *note repr(): 7cc. function. In Python 2.1, the variable *note sys.displayhook(): e5f. can be set to a callable object which will be called instead of *note repr(): 7cc. For example, you can set it to a special pretty-printing function: >>> # Create a recursive data structure ... L = [1,2,3] >>> L.append(L) >>> L # Show Python's default output [1, 2, 3, [...]] >>> # Use pprint.pprint() as the display function ... import sys, pprint >>> sys.displayhook = pprint.pprint >>> L [1, 2, 3, ] >>> See also ........ PEP 217(1) - Display Hook for Interactive Use Written and implemented by Moshe Zadka. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0217  File: python.info, Node: PEP 208 New Coercion Model, Next: PEP 241 Metadata in Python Packages, Prev: PEP 217 Interactive Display Hook, Up: What’s New in Python 2 1 1.16.11 PEP 208: New Coercion Model ----------------------------------- How numeric coercion is done at the C level was significantly modified. This will only affect the authors of C extensions to Python, allowing them more flexibility in writing extension types that support numeric operations. Extension types can now set the type flag ‘Py_TPFLAGS_CHECKTYPES’ in their ‘PyTypeObject’ structure to indicate that they support the new coercion model. In such extension types, the numeric slot functions can no longer assume that they’ll be passed two arguments of the same type; instead they may be passed two arguments of differing types, and can then perform their own internal coercion. If the slot function is passed a type it can’t handle, it can indicate the failure by returning a reference to the ‘Py_NotImplemented’ singleton value. The numeric functions of the other type will then be tried, and perhaps they can handle the operation; if the other type also returns ‘Py_NotImplemented’, then a *note TypeError: 192. will be raised. Numeric methods written in Python can also return ‘Py_NotImplemented’, causing the interpreter to act as if the method did not exist (perhaps raising a *note TypeError: 192, perhaps trying another object’s numeric methods). See also ........ PEP 208(1) - Reworking the Coercion Model Written and implemented by Neil Schemenauer, heavily based upon earlier work by Marc-André Lemburg. Read this to understand the fine points of how numeric operations will now be processed at the C level. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0208  File: python.info, Node: PEP 241 Metadata in Python Packages, Next: New and Improved Modules<4>, Prev: PEP 208 New Coercion Model, Up: What’s New in Python 2 1 1.16.12 PEP 241: Metadata in Python Packages -------------------------------------------- A common complaint from Python users is that there’s no single catalog of all the Python modules in existence. T. Middleton’s Vaults of Parnassus at ‘http://www.vex.net/parnassus/’ are the largest catalog of Python modules, but registering software at the Vaults is optional, and many people don’t bother. As a first small step toward fixing the problem, Python software packaged using the Distutils ‘sdist’ command will include a file named ‘PKG-INFO’ containing information about the package such as its name, version, and author (metadata, in cataloguing terminology). PEP 241(1) contains the full list of fields that can be present in the ‘PKG-INFO’ file. As people began to package their software using Python 2.1, more and more packages will include metadata, making it possible to build automated cataloguing systems and experiment with them. With the result experience, perhaps it’ll be possible to design a really good catalog and then build support for it into Python 2.2. For example, the Distutils ‘sdist’ and ‘bdist_*’ commands could support an ‘upload’ option that would automatically upload your package to a catalog server. You can start creating packages containing ‘PKG-INFO’ even if you’re not using Python 2.1, since a new release of the Distutils will be made for users of earlier Python versions. Version 1.0.2 of the Distutils includes the changes described in PEP 241(2), as well as various bugfixes and enhancements. It will be available from the Distutils SIG at ‘https://www.python.org/community/sigs/current/distutils-sig/’. See also ........ PEP 241(3) - Metadata for Python Software Packages Written and implemented by A.M. Kuchling. PEP 243(4) - Module Repository Upload Mechanism Written by Sean Reifschneider, this draft PEP describes a proposed mechanism for uploading Python packages to a central server. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0241 (2) https://www.python.org/dev/peps/pep-0241 (3) https://www.python.org/dev/peps/pep-0241 (4) https://www.python.org/dev/peps/pep-0243  File: python.info, Node: New and Improved Modules<4>, Next: Other Changes and Fixes<4>, Prev: PEP 241 Metadata in Python Packages, Up: What’s New in Python 2 1 1.16.13 New and Improved Modules -------------------------------- * Ka-Ping Yee contributed two new modules: ‘inspect.py’, a module for getting information about live Python code, and ‘pydoc.py’, a module for interactively converting docstrings to HTML or text. As a bonus, ‘Tools/scripts/pydoc’, which is now automatically installed, uses ‘pydoc.py’ to display documentation given a Python module, package, or class name. For example, ‘pydoc xml.dom’ displays the following: Python Library Documentation: package xml.dom in xml NAME xml.dom - W3C Document Object Model implementation for Python. FILE /usr/local/lib/python2.1/xml/dom/__init__.pyc DESCRIPTION The Python mapping of the Document Object Model is documented in the Python Library Reference in the section on the xml.dom package. This package contains the following modules: ... ‘pydoc’ also includes a Tk-based interactive help browser. ‘pydoc’ quickly becomes addictive; try it out! * Two different modules for unit testing were added to the standard library. The *note doctest: 67. module, contributed by Tim Peters, provides a testing framework based on running embedded examples in docstrings and comparing the results against the expected output. PyUnit, contributed by Steve Purcell, is a unit testing framework inspired by JUnit, which was in turn an adaptation of Kent Beck’s Smalltalk testing framework. See ‘http://pyunit.sourceforge.net/’ for more information about PyUnit. * The *note difflib: 37. module contains a class, ‘SequenceMatcher’, which compares two sequences and computes the changes required to transform one sequence into the other. For example, this module can be used to write a tool similar to the Unix ‘diff’ program, and in fact the sample program ‘Tools/scripts/ndiff.py’ demonstrates how to write such a script. * *note curses.panel: 2e, a wrapper for the panel library, part of ncurses and of SYSV curses, was contributed by Thomas Gellekum. The panel library provides windows with the additional feature of depth. Windows can be moved higher or lower in the depth ordering, and the panel library figures out where panels overlap and which sections are visible. * The PyXML package has gone through a few releases since Python 2.0, and Python 2.1 includes an updated version of the *note xml: 133. package. Some of the noteworthy changes include support for Expat 1.2 and later versions, the ability for Expat parsers to handle files in any encoding supported by Python, and various bugfixes for SAX, DOM, and the ‘minidom’ module. * Ping also contributed another hook for handling uncaught exceptions. *note sys.excepthook(): e63. can be set to a callable object. When an exception isn’t caught by any *note try: d72.…*note except: b3e. blocks, the exception will be passed to *note sys.excepthook(): e63, which can then do whatever it likes. At the Ninth Python Conference, Ping demonstrated an application for this hook: printing an extended traceback that not only lists the stack frames, but also lists the function arguments and the local variables for each frame. * Various functions in the *note time: 10a. module, such as ‘asctime()’ and ‘localtime()’, require a floating point argument containing the time in seconds since the epoch. The most common use of these functions is to work with the current time, so the floating point argument has been made optional; when a value isn’t provided, the current time will be used. For example, log file entries usually need a string containing the current time; in Python 2.1, ‘time.asctime()’ can be used, instead of the lengthier ‘time.asctime(time.localtime(time.time()))’ that was previously required. This change was proposed and implemented by Thomas Wouters. * The *note ftplib: 84. module now defaults to retrieving files in passive mode, because passive mode is more likely to work from behind a firewall. This request came from the Debian bug tracking system, since other Debian packages use *note ftplib: 84. to retrieve files and then don’t work from behind a firewall. It’s deemed unlikely that this will cause problems for anyone, because Netscape defaults to passive mode and few people complain, but if passive mode is unsuitable for your application or network setup, call ‘set_pasv(0)’ on FTP objects to disable passive mode. * Support for raw socket access has been added to the *note socket: ef. module, contributed by Grant Edwards. * The *note pstats: d4. module now contains a simple interactive statistics browser for displaying timing profiles for Python programs, invoked when the module is run as a script. Contributed by Eric S. Raymond. * A new implementation-dependent function, ‘sys._getframe([depth])’, has been added to return a given frame object from the current call stack. *note sys._getframe(): e64. returns the frame at the top of the call stack; if the optional integer argument `depth' is supplied, the function returns the frame that is `depth' calls below the top of the stack. For example, ‘sys._getframe(1)’ returns the caller’s frame object. This function is only present in CPython, not in Jython or the .NET implementation. Use it for debugging, and resist the temptation to put it into production code.  File: python.info, Node: Other Changes and Fixes<4>, Next: Acknowledgements<7>, Prev: New and Improved Modules<4>, Up: What’s New in Python 2 1 1.16.14 Other Changes and Fixes ------------------------------- There were relatively few smaller changes made in Python 2.1 due to the shorter release cycle. A search through the CVS change logs turns up 117 patches applied, and 136 bugs fixed; both figures are likely to be underestimates. Some of the more notable changes are: * A specialized object allocator is now optionally available, that should be faster than the system ‘malloc()’ and have less memory overhead. The allocator uses C’s ‘malloc()’ function to get large pools of memory, and then fulfills smaller memory requests from these pools. It can be enabled by providing the ‘--with-pymalloc’ option to the ‘configure’ script; see ‘Objects/obmalloc.c’ for the implementation details. Authors of C extension modules should test their code with the object allocator enabled, because some incorrect code may break, causing core dumps at runtime. There are a bunch of memory allocation functions in Python’s C API that have previously been just aliases for the C library’s ‘malloc()’ and ‘free()’, meaning that if you accidentally called mismatched functions, the error wouldn’t be noticeable. When the object allocator is enabled, these functions aren’t aliases of ‘malloc()’ and ‘free()’ any more, and calling the wrong function to free memory will get you a core dump. For example, if memory was allocated using ‘PyMem_New()’, it has to be freed using ‘PyMem_Del()’, not ‘free()’. A few modules included with Python fell afoul of this and had to be fixed; doubtless there are more third-party modules that will have the same problem. The object allocator was contributed by Vladimir Marangozov. * The speed of line-oriented file I/O has been improved because people often complain about its lack of speed, and because it’s often been used as a naïve benchmark. The *note readline(): de. method of file objects has therefore been rewritten to be much faster. The exact amount of the speedup will vary from platform to platform depending on how slow the C library’s ‘getc()’ was, but is around 66%, and potentially much faster on some particular operating systems. Tim Peters did much of the benchmarking and coding for this change, motivated by a discussion in comp.lang.python. A new module and method for file objects was also added, contributed by Jeff Epler. The new method, ‘xreadlines()’, is similar to the existing ‘xrange()’ built-in. ‘xreadlines()’ returns an opaque sequence object that only supports being iterated over, reading a line on every iteration but not reading the entire file into memory as the existing ‘readlines()’ method does. You’d use it like this: for line in sys.stdin.xreadlines(): # ... do something for each line ... ... For a fuller discussion of the line I/O changes, see the python-dev summary for January 1–15, 2001 at ‘https://mail.python.org/pipermail/python-dev/2001-January/’. * A new method, ‘popitem()’, was added to dictionaries to enable destructively iterating through the contents of a dictionary; this can be faster for large dictionaries because there’s no need to construct a list containing all the keys or values. ‘D.popitem()’ removes a random ‘(key, value)’ pair from the dictionary ‘D’ and returns it as a 2-tuple. This was implemented mostly by Tim Peters and Guido van Rossum, after a suggestion and preliminary patch by Moshe Zadka. * Modules can now control which names are imported when ‘from module import *’ is used, by defining an ‘__all__’ attribute containing a list of names that will be imported. One common complaint is that if the module imports other modules such as *note sys: fd. or *note string: f6, ‘from module import *’ will add them to the importing module’s namespace. To fix this, simply list the public names in ‘__all__’: # List public names __all__ = ['Database', 'open'] A stricter version of this patch was first suggested and implemented by Ben Wolfson, but after some python-dev discussion, a weaker final version was checked in. * Applying *note repr(): 7cc. to strings previously used octal escapes for non-printable characters; for example, a newline was ‘'\012'’. This was a vestigial trace of Python’s C ancestry, but today octal is of very little practical use. Ka-Ping Yee suggested using hex escapes instead of octal ones, and using the ‘\n’, ‘\t’, ‘\r’ escapes for the appropriate characters, and implemented this new formatting. * Syntax errors detected at compile-time can now raise exceptions containing the filename and line number of the error, a pleasant side effect of the compiler reorganization done by Jeremy Hylton. * C extensions which import other modules have been changed to use ‘PyImport_ImportModule()’, which means that they will use any import hooks that have been installed. This is also encouraged for third-party extensions that need to import some other module from C code. * The size of the Unicode character database was shrunk by another 340K thanks to Fredrik Lundh. * Some new ports were contributed: MacOS X (by Steven Majewski), Cygwin (by Jason Tishler); RISCOS (by Dietmar Schwertberger); Unixware 7 (by Billy G. Allie). And there’s the usual list of minor bugfixes, minor memory leaks, docstring edits, and other tweaks, too lengthy to be worth itemizing; see the CVS logs for the full details if you want them.  File: python.info, Node: Acknowledgements<7>, Prev: Other Changes and Fixes<4>, Up: What’s New in Python 2 1 1.16.15 Acknowledgements ------------------------ The author would like to thank the following people for offering suggestions on various drafts of this article: Graeme Cross, David Goodger, Jay Graves, Michael Hudson, Marc-André Lemburg, Fredrik Lundh, Neil Schemenauer, Thomas Wouters.  File: python.info, Node: What’s New in Python 2 0, Next: Changelog, Prev: What’s New in Python 2 1, Up: What’s New in Python 1.17 What’s New in Python 2.0 ============================= Author: A.M. Kuchling and Moshe Zadka * Menu: * Introduction: Introduction<3>. * What About Python 1.6?: What About Python 1 6?. * New Development Process:: * Unicode: Unicode<2>. * List Comprehensions:: * Augmented Assignment:: * String Methods:: * Garbage Collection of Cycles:: * Other Core Changes:: * Porting to 2.0: Porting to 2 0. * Extending/Embedding Changes:: * Distutils; Making Modules Easy to Install: Distutils Making Modules Easy to Install. * XML Modules:: * Module changes:: * New modules:: * IDLE Improvements:: * Deleted and Deprecated Modules:: * Acknowledgements: Acknowledgements<8>.  File: python.info, Node: Introduction<3>, Next: What About Python 1 6?, Up: What’s New in Python 2 0 1.17.1 Introduction ------------------- A new release of Python, version 2.0, was released on October 16, 2000. This article covers the exciting new features in 2.0, highlights some other useful changes, and points out a few incompatible changes that may require rewriting code. Python’s development never completely stops between releases, and a steady flow of bug fixes and improvements are always being submitted. A host of minor fixes, a few optimizations, additional docstrings, and better error messages went into 2.0; to list them all would be impossible, but they’re certainly significant. Consult the publicly-available CVS logs if you want to see the full list. This progress is due to the five developers working for PythonLabs are now getting paid to spend their days fixing bugs, and also due to the improved communication resulting from moving to SourceForge.  File: python.info, Node: What About Python 1 6?, Next: New Development Process, Prev: Introduction<3>, Up: What’s New in Python 2 0 1.17.2 What About Python 1.6? ----------------------------- Python 1.6 can be thought of as the Contractual Obligations Python release. After the core development team left CNRI in May 2000, CNRI requested that a 1.6 release be created, containing all the work on Python that had been performed at CNRI. Python 1.6 therefore represents the state of the CVS tree as of May 2000, with the most significant new feature being Unicode support. Development continued after May, of course, so the 1.6 tree received a few fixes to ensure that it’s forward-compatible with Python 2.0. 1.6 is therefore part of Python’s evolution, and not a side branch. So, should you take much interest in Python 1.6? Probably not. The 1.6final and 2.0beta1 releases were made on the same day (September 5, 2000), the plan being to finalize Python 2.0 within a month or so. If you have applications to maintain, there seems little point in breaking things by moving to 1.6, fixing them, and then having another round of breakage within a month by moving to 2.0; you’re better off just going straight to 2.0. Most of the really interesting features described in this document are only in 2.0, because a lot of work was done between May and September.  File: python.info, Node: New Development Process, Next: Unicode<2>, Prev: What About Python 1 6?, Up: What’s New in Python 2 0 1.17.3 New Development Process ------------------------------ The most important change in Python 2.0 may not be to the code at all, but to how Python is developed: in May 2000 the Python developers began using the tools made available by SourceForge for storing source code, tracking bug reports, and managing the queue of patch submissions. To report bugs or submit patches for Python 2.0, use the bug tracking and patch manager tools available from Python’s project page, located at ‘https://sourceforge.net/projects/python/’. The most important of the services now hosted at SourceForge is the Python CVS tree, the version-controlled repository containing the source code for Python. Previously, there were roughly 7 or so people who had write access to the CVS tree, and all patches had to be inspected and checked in by one of the people on this short list. Obviously, this wasn’t very scalable. By moving the CVS tree to SourceForge, it became possible to grant write access to more people; as of September 2000 there were 27 people able to check in changes, a fourfold increase. This makes possible large-scale changes that wouldn’t be attempted if they’d have to be filtered through the small group of core developers. For example, one day Peter Schneider-Kamp took it into his head to drop K&R C compatibility and convert the C source for Python to ANSI C. After getting approval on the python-dev mailing list, he launched into a flurry of checkins that lasted about a week, other developers joined in to help, and the job was done. If there were only 5 people with write access, probably that task would have been viewed as “nice, but not worth the time and effort needed” and it would never have gotten done. The shift to using SourceForge’s services has resulted in a remarkable increase in the speed of development. Patches now get submitted, commented on, revised by people other than the original submitter, and bounced back and forth between people until the patch is deemed worth checking in. Bugs are tracked in one central location and can be assigned to a specific person for fixing, and we can count the number of open bugs to measure progress. This didn’t come without a cost: developers now have more e-mail to deal with, more mailing lists to follow, and special tools had to be written for the new environment. For example, SourceForge sends default patch and bug notification e-mail messages that are completely unhelpful, so Ka-Ping Yee wrote an HTML screen-scraper that sends more useful messages. The ease of adding code caused a few initial growing pains, such as code was checked in before it was ready or without getting clear agreement from the developer group. The approval process that has emerged is somewhat similar to that used by the Apache group. Developers can vote +1, +0, -0, or -1 on a patch; +1 and -1 denote acceptance or rejection, while +0 and -0 mean the developer is mostly indifferent to the change, though with a slight positive or negative slant. The most significant change from the Apache model is that the voting is essentially advisory, letting Guido van Rossum, who has Benevolent Dictator For Life status, know what the general opinion is. He can still ignore the result of a vote, and approve or reject a change even if the community disagrees with him. Producing an actual patch is the last step in adding a new feature, and is usually easy compared to the earlier task of coming up with a good design. Discussions of new features can often explode into lengthy mailing list threads, making the discussion hard to follow, and no one can read every posting to python-dev. Therefore, a relatively formal process has been set up to write Python Enhancement Proposals (PEPs), modelled on the Internet RFC process. PEPs are draft documents that describe a proposed new feature, and are continually revised until the community reaches a consensus, either accepting or rejecting the proposal. Quoting from the introduction to PEP 1(1), “PEP Purpose and Guidelines”: PEP stands for Python Enhancement Proposal. A PEP is a design document providing information to the Python community, or describing a new feature for Python. The PEP should provide a concise technical specification of the feature and a rationale for the feature. We intend PEPs to be the primary mechanisms for proposing new features, for collecting community input on an issue, and for documenting the design decisions that have gone into Python. The PEP author is responsible for building consensus within the community and documenting dissenting opinions. Read the rest of PEP 1(2) for the details of the PEP editorial process, style, and format. PEPs are kept in the Python CVS tree on SourceForge, though they’re not part of the Python 2.0 distribution, and are also available in HTML form from ‘https://www.python.org/dev/peps/’. As of September 2000, there are 25 PEPS, ranging from PEP 201(3), “Lockstep Iteration”, to PEP 225, “Elementwise/Objectwise Operators”. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0001 (2) https://www.python.org/dev/peps/pep-0001 (3) https://www.python.org/dev/peps/pep-0201  File: python.info, Node: Unicode<2>, Next: List Comprehensions, Prev: New Development Process, Up: What’s New in Python 2 0 1.17.4 Unicode -------------- The largest new feature in Python 2.0 is a new fundamental data type: Unicode strings. Unicode uses 16-bit numbers to represent characters instead of the 8-bit number used by ASCII, meaning that 65,536 distinct characters can be supported. The final interface for Unicode support was arrived at through countless often-stormy discussions on the python-dev mailing list, and mostly implemented by Marc-André Lemburg, based on a Unicode string type implementation by Fredrik Lundh. A detailed explanation of the interface was written up as PEP 100(1), “Python Unicode Integration”. This article will simply cover the most significant points about the Unicode interfaces. In Python source code, Unicode strings are written as ‘u"string"’. Arbitrary Unicode characters can be written using a new escape sequence, ‘\uHHHH’, where `HHHH' is a 4-digit hexadecimal number from 0000 to FFFF. The existing ‘\xHHHH’ escape sequence can also be used, and octal escapes can be used for characters up to U+01FF, which is represented by ‘\777’. Unicode strings, just like regular strings, are an immutable sequence type. They can be indexed and sliced, but not modified in place. Unicode strings have an ‘encode( [encoding] )’ method that returns an 8-bit string in the desired encoding. Encodings are named by strings, such as ‘'ascii'’, ‘'utf-8'’, ‘'iso-8859-1'’, or whatever. A codec API is defined for implementing and registering new encodings that are then available throughout a Python program. If an encoding isn’t specified, the default encoding is usually 7-bit ASCII, though it can be changed for your Python installation by calling the ‘sys.setdefaultencoding(encoding)’ function in a customized version of ‘site.py’. Combining 8-bit and Unicode strings always coerces to Unicode, using the default ASCII encoding; the result of ‘'a' + u'bc'’ is ‘u'abc'’. New built-in functions have been added, and existing built-ins modified to support Unicode: * ‘unichr(ch)’ returns a Unicode string 1 character long, containing the character `ch'. * ‘ord(u)’, where `u' is a 1-character regular or Unicode string, returns the number of the character as an integer. * ‘unicode(string [, encoding] [, errors] )’ creates a Unicode string from an 8-bit string. ‘encoding’ is a string naming the encoding to use. The ‘errors’ parameter specifies the treatment of characters that are invalid for the current encoding; passing ‘'strict'’ as the value causes an exception to be raised on any encoding error, while ‘'ignore'’ causes errors to be silently ignored and ‘'replace'’ uses U+FFFD, the official replacement character, in case of any problems. * The ‘exec’ statement, and various built-ins such as ‘eval()’, ‘getattr()’, and ‘setattr()’ will also accept Unicode strings as well as regular strings. (It’s possible that the process of fixing this missed some built-ins; if you find a built-in function that accepts strings but doesn’t accept Unicode strings at all, please report it as a bug.) A new module, *note unicodedata: 11a, provides an interface to Unicode character properties. For example, ‘unicodedata.category(u'A')’ returns the 2-character string ‘Lu’, the ‘L’ denoting it’s a letter, and ‘u’ meaning that it’s uppercase. ‘unicodedata.bidirectional(u'\u0660')’ returns ‘AN’, meaning that U+0660 is an Arabic number. The *note codecs: 1c. module contains functions to look up existing encodings and register new ones. Unless you want to implement a new encoding, you’ll most often use the ‘codecs.lookup(encoding)’ function, which returns a 4-element tuple: ‘(encode_func, decode_func, stream_reader, stream_writer)’. * `encode_func' is a function that takes a Unicode string, and returns a 2-tuple ‘(string, length)’. `string' is an 8-bit string containing a portion (perhaps all) of the Unicode string converted into the given encoding, and `length' tells you how much of the Unicode string was converted. * `decode_func' is the opposite of `encode_func', taking an 8-bit string and returning a 2-tuple ‘(ustring, length)’, consisting of the resulting Unicode string `ustring' and the integer `length' telling how much of the 8-bit string was consumed. * `stream_reader' is a class that supports decoding input from a stream. `stream_reader(file_obj)' returns an object that supports the ‘read()’, *note readline(): de, and ‘readlines()’ methods. These methods will all translate from the given encoding and return Unicode strings. * `stream_writer', similarly, is a class that supports encoding output to a stream. `stream_writer(file_obj)' returns an object that supports the ‘write()’ and ‘writelines()’ methods. These methods expect Unicode strings, translating them to the given encoding on output. For example, the following code writes a Unicode string into a file, encoding it as UTF-8: import codecs unistr = u'\u0660\u2000ab ...' (UTF8_encode, UTF8_decode, UTF8_streamreader, UTF8_streamwriter) = codecs.lookup('UTF-8') output = UTF8_streamwriter( open( '/tmp/output', 'wb') ) output.write( unistr ) output.close() The following code would then read UTF-8 input from the file: input = UTF8_streamreader( open( '/tmp/output', 'rb') ) print repr(input.read()) input.close() Unicode-aware regular expressions are available through the *note re: dd. module, which has a new underlying implementation called SRE written by Fredrik Lundh of Secret Labs AB. A ‘-U’ command line option was added which causes the Python compiler to interpret all string literals as Unicode string literals. This is intended to be used in testing and future-proofing your Python code, since some future version of Python may drop support for 8-bit strings and provide only Unicode strings. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0100  File: python.info, Node: List Comprehensions, Next: Augmented Assignment, Prev: Unicode<2>, Up: What’s New in Python 2 0 1.17.5 List Comprehensions -------------------------- Lists are a workhorse data type in Python, and many programs manipulate a list at some point. Two common operations on lists are to loop over them, and either pick out the elements that meet a certain criterion, or apply some function to each element. For example, given a list of strings, you might want to pull out all the strings containing a given substring, or strip off trailing whitespace from each line. The existing *note map(): c2d. and *note filter(): c2e. functions can be used for this purpose, but they require a function as one of their arguments. This is fine if there’s an existing built-in function that can be passed directly, but if there isn’t, you have to create a little function to do the required work, and Python’s scoping rules make the result ugly if the little function needs additional information. Take the first example in the previous paragraph, finding all the strings in the list containing a given substring. You could write the following to do it: # Given the list L, make a list of all strings # containing the substring S. sublist = filter( lambda s, substring=S: string.find(s, substring) != -1, L) Because of Python’s scoping rules, a default argument is used so that the anonymous function created by the *note lambda: c2f. expression knows what substring is being searched for. List comprehensions make this cleaner: sublist = [ s for s in L if string.find(s, S) != -1 ] List comprehensions have the form: [ expression for expr in sequence1 for expr2 in sequence2 ... for exprN in sequenceN if condition ] The ‘for’…‘in’ clauses contain the sequences to be iterated over. The sequences do not have to be the same length, because they are `not' iterated over in parallel, but from left to right; this is explained more clearly in the following paragraphs. The elements of the generated list will be the successive values of `expression'. The final ‘if’ clause is optional; if present, `expression' is only evaluated and added to the result if `condition' is true. To make the semantics very clear, a list comprehension is equivalent to the following Python code: for expr1 in sequence1: for expr2 in sequence2: ... for exprN in sequenceN: if (condition): # Append the value of # the expression to the # resulting list. This means that when there are multiple ‘for’…‘in’ clauses, the resulting list will be equal to the product of the lengths of all the sequences. If you have two lists of length 3, the output list is 9 elements long: seq1 = 'abc' seq2 = (1,2,3) >>> [ (x,y) for x in seq1 for y in seq2] [('a', 1), ('a', 2), ('a', 3), ('b', 1), ('b', 2), ('b', 3), ('c', 1), ('c', 2), ('c', 3)] To avoid introducing an ambiguity into Python’s grammar, if `expression' is creating a tuple, it must be surrounded with parentheses. The first list comprehension below is a syntax error, while the second one is correct: # Syntax error [ x,y for x in seq1 for y in seq2] # Correct [ (x,y) for x in seq1 for y in seq2] The idea of list comprehensions originally comes from the functional programming language Haskell (‘https://www.haskell.org’). Greg Ewing argued most effectively for adding them to Python and wrote the initial list comprehension patch, which was then discussed for a seemingly endless time on the python-dev mailing list and kept up-to-date by Skip Montanaro.  File: python.info, Node: Augmented Assignment, Next: String Methods, Prev: List Comprehensions, Up: What’s New in Python 2 0 1.17.6 Augmented Assignment --------------------------- Augmented assignment operators, another long-requested feature, have been added to Python 2.0. Augmented assignment operators include ‘+=’, ‘-=’, ‘*=’, and so forth. For example, the statement ‘a += 2’ increments the value of the variable ‘a’ by 2, equivalent to the slightly lengthier ‘a = a + 2’. The full list of supported assignment operators is ‘+=’, ‘-=’, ‘*=’, ‘/=’, ‘%=’, ‘**=’, ‘&=’, ‘|=’, ‘^=’, ‘>>=’, and ‘<<=’. Python classes can override the augmented assignment operators by defining methods named *note __iadd__(): e6f, *note __isub__(): e70, etc. For example, the following ‘Number’ class stores a number and supports using += to create a new instance with an incremented value. class Number: def __init__(self, value): self.value = value def __iadd__(self, increment): return Number( self.value + increment) n = Number(5) n += 3 print n.value The *note __iadd__(): e6f. special method is called with the value of the increment, and should return a new instance with an appropriately modified value; this return value is bound as the new value of the variable on the left-hand side. Augmented assignment operators were first introduced in the C programming language, and most C-derived languages, such as ‘awk’, C++, Java, Perl, and PHP also support them. The augmented assignment patch was implemented by Thomas Wouters.  File: python.info, Node: String Methods, Next: Garbage Collection of Cycles, Prev: Augmented Assignment, Up: What’s New in Python 2 0 1.17.7 String Methods --------------------- Until now string-manipulation functionality was in the *note string: f6. module, which was usually a front-end for the ‘strop’ module written in C. The addition of Unicode posed a difficulty for the ‘strop’ module, because the functions would all need to be rewritten in order to accept either 8-bit or Unicode strings. For functions such as ‘string.replace()’, which takes 3 string arguments, that means eight possible permutations, and correspondingly complicated code. Instead, Python 2.0 pushes the problem onto the string type, making string manipulation functionality available through methods on both 8-bit strings and Unicode strings. >>> 'andrew'.capitalize() 'Andrew' >>> 'hostname'.replace('os', 'linux') 'hlinuxtname' >>> 'moshe'.find('sh') 2 One thing that hasn’t changed, a noteworthy April Fools’ joke notwithstanding, is that Python strings are immutable. Thus, the string methods return new strings, and do not modify the string on which they operate. The old *note string: f6. module is still around for backwards compatibility, but it mostly acts as a front-end to the new string methods. Two methods which have no parallel in pre-2.0 versions, although they did exist in JPython for quite some time, are ‘startswith()’ and ‘endswith()’. ‘s.startswith(t)’ is equivalent to ‘s[:len(t)] == t’, while ‘s.endswith(t)’ is equivalent to ‘s[-len(t):] == t’. One other method which deserves special mention is ‘join()’. The ‘join()’ method of a string receives one parameter, a sequence of strings, and is equivalent to the ‘string.join()’ function from the old *note string: f6. module, with the arguments reversed. In other words, ‘s.join(seq)’ is equivalent to the old ‘string.join(seq, s)’.  File: python.info, Node: Garbage Collection of Cycles, Next: Other Core Changes, Prev: String Methods, Up: What’s New in Python 2 0 1.17.8 Garbage Collection of Cycles ----------------------------------- The C implementation of Python uses reference counting to implement garbage collection. Every Python object maintains a count of the number of references pointing to itself, and adjusts the count as references are created or destroyed. Once the reference count reaches zero, the object is no longer accessible, since you need to have a reference to an object to access it, and if the count is zero, no references exist any longer. Reference counting has some pleasant properties: it’s easy to understand and implement, and the resulting implementation is portable, fairly fast, and reacts well with other libraries that implement their own memory handling schemes. The major problem with reference counting is that it sometimes doesn’t realise that objects are no longer accessible, resulting in a memory leak. This happens when there are cycles of references. Consider the simplest possible cycle, a class instance which has a reference to itself: instance = SomeClass() instance.myself = instance After the above two lines of code have been executed, the reference count of ‘instance’ is 2; one reference is from the variable named ‘'instance'’, and the other is from the ‘myself’ attribute of the instance. If the next line of code is ‘del instance’, what happens? The reference count of ‘instance’ is decreased by 1, so it has a reference count of 1; the reference in the ‘myself’ attribute still exists. Yet the instance is no longer accessible through Python code, and it could be deleted. Several objects can participate in a cycle if they have references to each other, causing all of the objects to be leaked. Python 2.0 fixes this problem by periodically executing a cycle detection algorithm which looks for inaccessible cycles and deletes the objects involved. A new *note gc: 86. module provides functions to perform a garbage collection, obtain debugging statistics, and tuning the collector’s parameters. Running the cycle detection algorithm takes some time, and therefore will result in some additional overhead. It is hoped that after we’ve gotten experience with the cycle collection from using 2.0, Python 2.1 will be able to minimize the overhead with careful tuning. It’s not yet obvious how much performance is lost, because benchmarking this is tricky and depends crucially on how often the program creates and destroys objects. The detection of cycles can be disabled when Python is compiled, if you can’t afford even a tiny speed penalty or suspect that the cycle collection is buggy, by specifying the ‘--without-cycle-gc’ switch when running the ‘configure’ script. Several people tackled this problem and contributed to a solution. An early implementation of the cycle detection approach was written by Toby Kelsey. The current algorithm was suggested by Eric Tiedemann during a visit to CNRI, and Guido van Rossum and Neil Schemenauer wrote two different implementations, which were later integrated by Neil. Lots of other people offered suggestions along the way; the March 2000 archives of the python-dev mailing list contain most of the relevant discussion, especially in the threads titled “Reference cycle collection for Python” and “Finalization again”.  File: python.info, Node: Other Core Changes, Next: Porting to 2 0, Prev: Garbage Collection of Cycles, Up: What’s New in Python 2 0 1.17.9 Other Core Changes ------------------------- Various minor changes have been made to Python’s syntax and built-in functions. None of the changes are very far-reaching, but they’re handy conveniences. * Menu: * Minor Language Changes:: * Changes to Built-in Functions::  File: python.info, Node: Minor Language Changes, Next: Changes to Built-in Functions, Up: Other Core Changes 1.17.9.1 Minor Language Changes ............................... A new syntax makes it more convenient to call a given function with a tuple of arguments and/or a dictionary of keyword arguments. In Python 1.5 and earlier, you’d use the ‘apply()’ built-in function: ‘apply(f, args, kw)’ calls the function ‘f()’ with the argument tuple `args' and the keyword arguments in the dictionary `kw'. ‘apply()’ is the same in 2.0, but thanks to a patch from Greg Ewing, ‘f(*args, **kw)’ is a shorter and clearer way to achieve the same effect. This syntax is symmetrical with the syntax for defining functions: def f(*args, **kw): # args is a tuple of positional args, # kw is a dictionary of keyword args ... The ‘print’ statement can now have its output directed to a file-like object by following the ‘print’ with ‘>> file’, similar to the redirection operator in Unix shells. Previously you’d either have to use the ‘write()’ method of the file-like object, which lacks the convenience and simplicity of ‘print’, or you could assign a new value to ‘sys.stdout’ and then restore the old value. For sending output to standard error, it’s much easier to write this: print >> sys.stderr, "Warning: action field not supplied" Modules can now be renamed on importing them, using the syntax ‘import module as name’ or ‘from module import name as othername’. The patch was submitted by Thomas Wouters. A new format style is available when using the ‘%’ operator; ‘%r’ will insert the *note repr(): 7cc. of its argument. This was also added from symmetry considerations, this time for symmetry with the existing ‘%s’ format style, which inserts the *note str(): 330. of its argument. For example, ‘'%r %s' % ('abc', 'abc')’ returns a string containing ‘'abc' abc’. Previously there was no way to implement a class that overrode Python’s built-in *note in: 7a3. operator and implemented a custom version. ‘obj in seq’ returns true if `obj' is present in the sequence `seq'; Python computes this by simply trying every index of the sequence until either `obj' is found or an *note IndexError: e75. is encountered. Moshe Zadka contributed a patch which adds a *note __contains__(): d28. magic method for providing a custom implementation for ‘in’. Additionally, new built-in objects written in C can define what ‘in’ means for them via a new slot in the sequence protocol. Earlier versions of Python used a recursive algorithm for deleting objects. Deeply nested data structures could cause the interpreter to fill up the C stack and crash; Christian Tismer rewrote the deletion logic to fix this problem. On a related note, comparing recursive objects recursed infinitely and crashed; Jeremy Hylton rewrote the code to no longer crash, producing a useful result instead. For example, after this code: a = [] b = [] a.append(a) b.append(b) The comparison ‘a==b’ returns true, because the two recursive data structures are isomorphic. See the thread “trashcan and PR#7” in the April 2000 archives of the python-dev mailing list for the discussion leading up to this implementation, and some useful relevant links. Note that comparisons can now also raise exceptions. In earlier versions of Python, a comparison operation such as ‘cmp(a,b)’ would always produce an answer, even if a user-defined ‘__cmp__()’ method encountered an error, since the resulting exception would simply be silently swallowed. Work has been done on porting Python to 64-bit Windows on the Itanium processor, mostly by Trent Mick of ActiveState. (Confusingly, ‘sys.platform’ is still ‘'win32'’ on Win64 because it seems that for ease of porting, MS Visual C++ treats code as 32 bit on Itanium.) PythonWin also supports Windows CE; see the Python CE page at ‘http://pythonce.sourceforge.net/’ for more information. Another new platform is Darwin/MacOS X; initial support for it is in Python 2.0. Dynamic loading works, if you specify “configure –with-dyld –with-suffix=.x”. Consult the README in the Python source distribution for more instructions. An attempt has been made to alleviate one of Python’s warts, the often-confusing *note NameError: d7b. exception when code refers to a local variable before the variable has been assigned a value. For example, the following code raises an exception on the ‘print’ statement in both 1.5.2 and 2.0; in 1.5.2 a *note NameError: d7b. exception is raised, while 2.0 raises a new *note UnboundLocalError: e76. exception. *note UnboundLocalError: e76. is a subclass of *note NameError: d7b, so any existing code that expects *note NameError: d7b. to be raised should still work. def f(): print "i=",i i = i + 1 f() Two new exceptions, *note TabError: e77. and *note IndentationError: e78, have been introduced. They’re both subclasses of *note SyntaxError: 458, and are raised when Python code is found to be improperly indented.  File: python.info, Node: Changes to Built-in Functions, Prev: Minor Language Changes, Up: Other Core Changes 1.17.9.2 Changes to Built-in Functions ...................................... A new built-in, ‘zip(seq1, seq2, ...)’, has been added. *note zip(): c32. returns a list of tuples where each tuple contains the i-th element from each of the argument sequences. The difference between *note zip(): c32. and ‘map(None, seq1, seq2)’ is that *note map(): c2d. pads the sequences with ‘None’ if the sequences aren’t all of the same length, while *note zip(): c32. truncates the returned list to the length of the shortest argument sequence. The *note int(): 184. and ‘long()’ functions now accept an optional “base” parameter when the first argument is a string. ‘int('123', 10)’ returns 123, while ‘int('123', 16)’ returns 291. ‘int(123, 16)’ raises a *note TypeError: 192. exception with the message “can’t convert non-string with explicit base”. A new variable holding more detailed version information has been added to the *note sys: fd. module. ‘sys.version_info’ is a tuple ‘(major, minor, micro, level, serial)’ For example, in a hypothetical 2.0.1beta1, ‘sys.version_info’ would be ‘(2, 0, 1, 'beta', 1)’. `level' is a string such as ‘"alpha"’, ‘"beta"’, or ‘"final"’ for a final release. Dictionaries have an odd new method, ‘setdefault(key, default)’, which behaves similarly to the existing ‘get()’ method. However, if the key is missing, ‘setdefault()’ both returns the value of `default' as ‘get()’ would do, and also inserts it into the dictionary as the value for `key'. Thus, the following lines of code: if dict.has_key( key ): return dict[key] else: dict[key] = [] return dict[key] can be reduced to a single ‘return dict.setdefault(key, [])’ statement. The interpreter sets a maximum recursion depth in order to catch runaway recursion before filling the C stack and causing a core dump or GPF.. Previously this limit was fixed when you compiled Python, but in 2.0 the maximum recursion depth can be read and modified using *note sys.getrecursionlimit(): e7a. and *note sys.setrecursionlimit(): e7b. The default value is 1000, and a rough maximum value for a given platform can be found by running a new script, ‘Misc/find_recursionlimit.py’.  File: python.info, Node: Porting to 2 0, Next: Extending/Embedding Changes, Prev: Other Core Changes, Up: What’s New in Python 2 0 1.17.10 Porting to 2.0 ---------------------- New Python releases try hard to be compatible with previous releases, and the record has been pretty good. However, some changes are considered useful enough, usually because they fix initial design decisions that turned out to be actively mistaken, that breaking backward compatibility can’t always be avoided. This section lists the changes in Python 2.0 that may cause old Python code to break. The change which will probably break the most code is tightening up the arguments accepted by some methods. Some methods would take multiple arguments and treat them as a tuple, particularly various list methods such as ‘append()’ and ‘insert()’. In earlier versions of Python, if ‘L’ is a list, ‘L.append( 1,2 )’ appends the tuple ‘(1,2)’ to the list. In Python 2.0 this causes a *note TypeError: 192. exception to be raised, with the message: ‘append requires exactly 1 argument; 2 given’. The fix is to simply add an extra set of parentheses to pass both values as a tuple: ‘L.append( (1,2) )’. The earlier versions of these methods were more forgiving because they used an old function in Python’s C interface to parse their arguments; 2.0 modernizes them to use ‘PyArg_ParseTuple()’, the current argument parsing function, which provides more helpful error messages and treats multi-argument calls as errors. If you absolutely must use 2.0 but can’t fix your code, you can edit ‘Objects/listobject.c’ and define the preprocessor symbol ‘NO_STRICT_LIST_APPEND’ to preserve the old behaviour; this isn’t recommended. Some of the functions in the *note socket: ef. module are still forgiving in this way. For example, ‘socket.connect( ('hostname', 25) )()’ is the correct form, passing a tuple representing an IP address, but ‘socket.connect( 'hostname', 25 )()’ also works. ‘socket.connect_ex()’ and ‘socket.bind()’ are similarly easy-going. 2.0alpha1 tightened these functions up, but because the documentation actually used the erroneous multiple argument form, many people wrote code which would break with the stricter checking. GvR backed out the changes in the face of public reaction, so for the *note socket: ef. module, the documentation was fixed and the multiple argument form is simply marked as deprecated; it `will' be tightened up again in a future Python version. The ‘\x’ escape in string literals now takes exactly 2 hex digits. Previously it would consume all the hex digits following the ‘x’ and take the lowest 8 bits of the result, so ‘\x123456’ was equivalent to ‘\x56’. The *note AttributeError: 39b. and *note NameError: d7b. exceptions have a more friendly error message, whose text will be something like ‘'Spam' instance has no attribute 'eggs'’ or ‘name 'eggs' is not defined’. Previously the error message was just the missing attribute name ‘eggs’, and code written to take advantage of this fact will break in 2.0. Some work has been done to make integers and long integers a bit more interchangeable. In 1.5.2, large-file support was added for Solaris, to allow reading files larger than 2 GiB; this made the ‘tell()’ method of file objects return a long integer instead of a regular integer. Some code would subtract two file offsets and attempt to use the result to multiply a sequence or slice a string, but this raised a *note TypeError: 192. In 2.0, long integers can be used to multiply or slice a sequence, and it’ll behave as you’d intuitively expect it to; ‘3L * 'abc'’ produces ‘abcabcabc’, and ‘(0,1,2,3)[2L:4L]’ produces (2,3). Long integers can also be used in various contexts where previously only integers were accepted, such as in the ‘seek()’ method of file objects, and in the formats supported by the ‘%’ operator (‘%d’, ‘%i’, ‘%x’, etc.). For example, ‘"%d" % 2L**64’ will produce the string ‘18446744073709551616’. The subtlest long integer change of all is that the *note str(): 330. of a long integer no longer has a trailing ‘L’ character, though *note repr(): 7cc. still includes it. The ‘L’ annoyed many people who wanted to print long integers that looked just like regular integers, since they had to go out of their way to chop off the character. This is no longer a problem in 2.0, but code which does ‘str(longval)[:-1]’ and assumes the ‘L’ is there, will now lose the final digit. Taking the *note repr(): 7cc. of a float now uses a different formatting precision than *note str(): 330. *note repr(): 7cc. uses ‘%.17g’ format string for C’s ‘sprintf()’, while *note str(): 330. uses ‘%.12g’ as before. The effect is that *note repr(): 7cc. may occasionally show more decimal places than *note str(): 330, for certain numbers. For example, the number 8.1 can’t be represented exactly in binary, so ‘repr(8.1)’ is ‘'8.0999999999999996'’, while str(8.1) is ‘'8.1'’. The ‘-X’ command-line option, which turned all standard exceptions into strings instead of classes, has been removed; the standard exceptions will now always be classes. The ‘exceptions’ module containing the standard exceptions was translated from Python to a built-in C module, written by Barry Warsaw and Fredrik Lundh.  File: python.info, Node: Extending/Embedding Changes, Next: Distutils Making Modules Easy to Install, Prev: Porting to 2 0, Up: What’s New in Python 2 0 1.17.11 Extending/Embedding Changes ----------------------------------- Some of the changes are under the covers, and will only be apparent to people writing C extension modules or embedding a Python interpreter in a larger application. If you aren’t dealing with Python’s C API, you can safely skip this section. The version number of the Python C API was incremented, so C extensions compiled for 1.5.2 must be recompiled in order to work with 2.0. On Windows, it’s not possible for Python 2.0 to import a third party extension built for Python 1.5.x due to how Windows DLLs work, so Python will raise an exception and the import will fail. Users of Jim Fulton’s ExtensionClass module will be pleased to find out that hooks have been added so that ExtensionClasses are now supported by *note isinstance(): 44f. and *note issubclass(): 450. This means you no longer have to remember to write code such as ‘if type(obj) == myExtensionClass’, but can use the more natural ‘if isinstance(obj, myExtensionClass)’. The ‘Python/importdl.c’ file, which was a mass of #ifdefs to support dynamic loading on many different platforms, was cleaned up and reorganised by Greg Stein. ‘importdl.c’ is now quite small, and platform-specific code has been moved into a bunch of ‘Python/dynload_*.c’ files. Another cleanup: there were also a number of ‘my*.h’ files in the Include/ directory that held various portability hacks; they’ve been merged into a single file, ‘Include/pyport.h’. Vladimir Marangozov’s long-awaited malloc restructuring was completed, to make it easy to have the Python interpreter use a custom allocator instead of C’s standard ‘malloc()’. For documentation, read the comments in ‘Include/pymem.h’ and ‘Include/objimpl.h’. For the lengthy discussions during which the interface was hammered out, see the Web archives of the ‘patches’ and ‘python-dev’ lists at python.org. Recent versions of the GUSI development environment for MacOS support POSIX threads. Therefore, Python’s POSIX threading support now works on the Macintosh. Threading support using the user-space GNU ‘pth’ library was also contributed. Threading support on Windows was enhanced, too. Windows supports thread locks that use kernel objects only in case of contention; in the common case when there’s no contention, they use simpler functions which are an order of magnitude faster. A threaded version of Python 1.5.2 on NT is twice as slow as an unthreaded version; with the 2.0 changes, the difference is only 10%. These improvements were contributed by Yakov Markovitch. Python 2.0’s source now uses only ANSI C prototypes, so compiling Python now requires an ANSI C compiler, and can no longer be done using a compiler that only supports K&R C. Previously the Python virtual machine used 16-bit numbers in its bytecode, limiting the size of source files. In particular, this affected the maximum size of literal lists and dictionaries in Python source; occasionally people who are generating Python code would run into this limit. A patch by Charles G. Waldman raises the limit from ‘2^16’ to ‘2^{32}’. Three new convenience functions intended for adding constants to a module’s dictionary at module initialization time were added: ‘PyModule_AddObject()’, ‘PyModule_AddIntConstant()’, and ‘PyModule_AddStringConstant()’. Each of these functions takes a module object, a null-terminated C string containing the name to be added, and a third argument for the value to be assigned to the name. This third argument is, respectively, a Python object, a C long, or a C string. A wrapper API was added for Unix-style signal handlers. ‘PyOS_getsig()’ gets a signal handler and ‘PyOS_setsig()’ will set a new handler.  File: python.info, Node: Distutils Making Modules Easy to Install, Next: XML Modules, Prev: Extending/Embedding Changes, Up: What’s New in Python 2 0 1.17.12 Distutils: Making Modules Easy to Install ------------------------------------------------- Before Python 2.0, installing modules was a tedious affair – there was no way to figure out automatically where Python is installed, or what compiler options to use for extension modules. Software authors had to go through an arduous ritual of editing Makefiles and configuration files, which only really work on Unix and leave Windows and MacOS unsupported. Python users faced wildly differing installation instructions which varied between different extension packages, which made administering a Python installation something of a chore. The SIG for distribution utilities, shepherded by Greg Ward, has created the Distutils, a system to make package installation much easier. They form the *note distutils: 39. package, a new part of Python’s standard library. In the best case, installing a Python module from source will require the same steps: first you simply mean unpack the tarball or zip archive, and the run “‘python setup.py install’”. The platform will be automatically detected, the compiler will be recognized, C extension modules will be compiled, and the distribution installed into the proper directory. Optional command-line arguments provide more control over the installation process, the distutils package offers many places to override defaults – separating the build from the install, building or installing in non-default directories, and more. In order to use the Distutils, you need to write a ‘setup.py’ script. For the simple case, when the software contains only .py files, a minimal ‘setup.py’ can be just a few lines long: from distutils.core import setup setup (name = "foo", version = "1.0", py_modules = ["module1", "module2"]) The ‘setup.py’ file isn’t much more complicated if the software consists of a few packages: from distutils.core import setup setup (name = "foo", version = "1.0", packages = ["package", "package.subpackage"]) A C extension can be the most complicated case; here’s an example taken from the PyXML package: from distutils.core import setup, Extension expat_extension = Extension('xml.parsers.pyexpat', define_macros = [('XML_NS', None)], include_dirs = [ 'extensions/expat/xmltok', 'extensions/expat/xmlparse' ], sources = [ 'extensions/pyexpat.c', 'extensions/expat/xmltok/xmltok.c', 'extensions/expat/xmltok/xmlrole.c', ] ) setup (name = "PyXML", version = "0.5.4", ext_modules =[ expat_extension ] ) The Distutils can also take care of creating source and binary distributions. The “sdist” command, run by “‘python setup.py sdist’’, builds a source distribution such as ‘foo-1.0.tar.gz’. Adding new commands isn’t difficult, “bdist_rpm” and “bdist_wininst” commands have already been contributed to create an RPM distribution and a Windows installer for the software, respectively. Commands to create other distribution formats such as Debian packages and Solaris ‘.pkg’ files are in various stages of development. All this is documented in a new manual, `Distributing Python Modules', that joins the basic set of Python documentation.  File: python.info, Node: XML Modules, Next: Module changes, Prev: Distutils Making Modules Easy to Install, Up: What’s New in Python 2 0 1.17.13 XML Modules ------------------- Python 1.5.2 included a simple XML parser in the form of the ‘xmllib’ module, contributed by Sjoerd Mullender. Since 1.5.2’s release, two different interfaces for processing XML have become common: SAX2 (version 2 of the Simple API for XML) provides an event-driven interface with some similarities to ‘xmllib’, and the DOM (Document Object Model) provides a tree-based interface, transforming an XML document into a tree of nodes that can be traversed and modified. Python 2.0 includes a SAX2 interface and a stripped-down DOM interface as part of the *note xml: 133. package. Here we will give a brief overview of these new interfaces; consult the Python documentation or the source code for complete details. The Python XML SIG is also working on improved documentation. * Menu: * SAX2 Support:: * DOM Support:: * Relationship to PyXML::  File: python.info, Node: SAX2 Support, Next: DOM Support, Up: XML Modules 1.17.13.1 SAX2 Support ...................... SAX defines an event-driven interface for parsing XML. To use SAX, you must write a SAX handler class. Handler classes inherit from various classes provided by SAX, and override various methods that will then be called by the XML parser. For example, the ‘startElement()’ and ‘endElement()’ methods are called for every starting and end tag encountered by the parser, the ‘characters()’ method is called for every chunk of character data, and so forth. The advantage of the event-driven approach is that the whole document doesn’t have to be resident in memory at any one time, which matters if you are processing really huge documents. However, writing the SAX handler class can get very complicated if you’re trying to modify the document structure in some elaborate way. For example, this little example program defines a handler that prints a message for every starting and ending tag, and then parses the file ‘hamlet.xml’ using it: from xml import sax class SimpleHandler(sax.ContentHandler): def startElement(self, name, attrs): print 'Start of element:', name, attrs.keys() def endElement(self, name): print 'End of element:', name # Create a parser object parser = sax.make_parser() # Tell it what handler to use handler = SimpleHandler() parser.setContentHandler( handler ) # Parse a file! parser.parse( 'hamlet.xml' ) For more information, consult the Python documentation, or the XML HOWTO at ‘http://pyxml.sourceforge.net/topics/howto/xml-howto.html’.  File: python.info, Node: DOM Support, Next: Relationship to PyXML, Prev: SAX2 Support, Up: XML Modules 1.17.13.2 DOM Support ..................... The Document Object Model is a tree-based representation for an XML document. A top-level ‘Document’ instance is the root of the tree, and has a single child which is the top-level ‘Element’ instance. This ‘Element’ has children nodes representing character data and any sub-elements, which may have further children of their own, and so forth. Using the DOM you can traverse the resulting tree any way you like, access element and attribute values, insert and delete nodes, and convert the tree back into XML. The DOM is useful for modifying XML documents, because you can create a DOM tree, modify it by adding new nodes or rearranging subtrees, and then produce a new XML document as output. You can also construct a DOM tree manually and convert it to XML, which can be a more flexible way of producing XML output than simply writing ‘’…‘’ to a file. The DOM implementation included with Python lives in the *note xml.dom.minidom: 135. module. It’s a lightweight implementation of the Level 1 DOM with support for XML namespaces. The ‘parse()’ and ‘parseString()’ convenience functions are provided for generating a DOM tree: from xml.dom import minidom doc = minidom.parse('hamlet.xml') ‘doc’ is a ‘Document’ instance. ‘Document’, like all the other DOM classes such as ‘Element’ and ‘Text’, is a subclass of the ‘Node’ base class. All the nodes in a DOM tree therefore support certain common methods, such as ‘toxml()’ which returns a string containing the XML representation of the node and its children. Each class also has special methods of its own; for example, ‘Element’ and ‘Document’ instances have a method to find all child elements with a given tag name. Continuing from the previous 2-line example: perslist = doc.getElementsByTagName( 'PERSONA' ) print perslist[0].toxml() print perslist[1].toxml() For the `Hamlet' XML file, the above few lines output: CLAUDIUS, king of Denmark. HAMLET, son to the late, and nephew to the present king. The root element of the document is available as ‘doc.documentElement’, and its children can be easily modified by deleting, adding, or removing nodes: root = doc.documentElement # Remove the first child root.removeChild( root.childNodes[0] ) # Move the new first child to the end root.appendChild( root.childNodes[0] ) # Insert the new first child (originally, # the third child) before the 20th child. root.insertBefore( root.childNodes[0], root.childNodes[20] ) Again, I will refer you to the Python documentation for a complete listing of the different ‘Node’ classes and their various methods.  File: python.info, Node: Relationship to PyXML, Prev: DOM Support, Up: XML Modules 1.17.13.3 Relationship to PyXML ............................... The XML Special Interest Group has been working on XML-related Python code for a while. Its code distribution, called PyXML, is available from the SIG’s Web pages at ‘https://www.python.org/community/sigs/current/xml-sig’. The PyXML distribution also used the package name ‘xml’. If you’ve written programs that used PyXML, you’re probably wondering about its compatibility with the 2.0 *note xml: 133. package. The answer is that Python 2.0’s *note xml: 133. package isn’t compatible with PyXML, but can be made compatible by installing a recent version PyXML. Many applications can get by with the XML support that is included with Python 2.0, but more complicated applications will require that the full PyXML package will be installed. When installed, PyXML versions 0.6.0 or greater will replace the *note xml: 133. package shipped with Python, and will be a strict superset of the standard package, adding a bunch of additional features. Some of the additional features in PyXML include: * 4DOM, a full DOM implementation from FourThought, Inc. * The xmlproc validating parser, written by Lars Marius Garshol. * The ‘sgmlop’ parser accelerator module, written by Fredrik Lundh.  File: python.info, Node: Module changes, Next: New modules, Prev: XML Modules, Up: What’s New in Python 2 0 1.17.14 Module changes ---------------------- Lots of improvements and bugfixes were made to Python’s extensive standard library; some of the affected modules include *note readline: de, ‘ConfigParser’, *note cgi: 16, *note calendar: 15, *note posix: d1, *note readline: de, ‘xmllib’, *note aifc: 5, ‘chunk, wave’, *note random: dc, *note shelve: e7, and *note nntplib: c0. Consult the CVS logs for the exact patch-by-patch details. Brian Gallew contributed OpenSSL support for the *note socket: ef. module. OpenSSL is an implementation of the Secure Socket Layer, which encrypts the data being sent over a socket. When compiling Python, you can edit ‘Modules/Setup’ to include SSL support, which adds an additional function to the *note socket: ef. module: ‘socket.ssl(socket, keyfile, certfile)’, which takes a socket object and returns an SSL socket. The ‘httplib’ and *note urllib: 11d. modules were also changed to support ‘https://’ URLs, though no one has implemented FTP or SMTP over SSL. The ‘httplib’ module has been rewritten by Greg Stein to support HTTP/1.1. Backward compatibility with the 1.5 version of ‘httplib’ is provided, though using HTTP/1.1 features such as pipelining will require rewriting code to use a different set of interfaces. The ‘Tkinter’ module now supports Tcl/Tk version 8.1, 8.2, or 8.3, and support for the older 7.x versions has been dropped. The Tkinter module now supports displaying Unicode strings in Tk widgets. Also, Fredrik Lundh contributed an optimization which makes operations like ‘create_line’ and ‘create_polygon’ much faster, especially when using lots of coordinates. The *note curses: 2c. module has been greatly extended, starting from Oliver Andrich’s enhanced version, to provide many additional functions from ncurses and SYSV curses, such as colour, alternative character set support, pads, and mouse support. This means the module is no longer compatible with operating systems that only have BSD curses, but there don’t seem to be any currently maintained OSes that fall into this category. As mentioned in the earlier discussion of 2.0’s Unicode support, the underlying implementation of the regular expressions provided by the *note re: dd. module has been changed. SRE, a new regular expression engine written by Fredrik Lundh and partially funded by Hewlett Packard, supports matching against both 8-bit strings and Unicode strings.  File: python.info, Node: New modules, Next: IDLE Improvements, Prev: Module changes, Up: What’s New in Python 2 0 1.17.15 New modules ------------------- A number of new modules were added. We’ll simply list them with brief descriptions; consult the 2.0 documentation for the details of a particular module. * *note atexit: c.: For registering functions to be called before the Python interpreter exits. Code that currently sets ‘sys.exitfunc’ directly should be changed to use the *note atexit: c. module instead, importing *note atexit: c. and calling *note atexit.register(): e85. with the function to be called on exit. (Contributed by Skip Montanaro.) * *note codecs: 1c, ‘encodings’, *note unicodedata: 11a.: Added as part of the new Unicode support. * *note filecmp: 7f.: Supersedes the old ‘cmp’, ‘cmpcache’ and ‘dircmp’ modules, which have now become deprecated. (Contributed by Gordon MacMillan and Moshe Zadka.) * *note gettext: 89.: This module provides internationalization (I18N) and localization (L10N) support for Python programs by providing an interface to the GNU gettext message catalog library. (Integrated by Barry Warsaw, from separate contributions by Martin von Löwis, Peter Funk, and James Henstridge.) * ‘linuxaudiodev’: Support for the ‘/dev/audio’ device on Linux, a twin to the existing ‘sunaudiodev’ module. (Contributed by Peter Bosch, with fixes by Jeremy Hylton.) * *note mmap: b3.: An interface to memory-mapped files on both Windows and Unix. A file’s contents can be mapped directly into memory, at which point it behaves like a mutable string, so its contents can be read and modified. They can even be passed to functions that expect ordinary strings, such as the *note re: dd. module. (Contributed by Sam Rushing, with some extensions by A.M. Kuchling.) * ‘pyexpat’: An interface to the Expat XML parser. (Contributed by Paul Prescod.) * ‘robotparser’: Parse a ‘robots.txt’ file, which is used for writing Web spiders that politely avoid certain areas of a Web site. The parser accepts the contents of a ‘robots.txt’ file, builds a set of rules from it, and can then answer questions about the fetchability of a given URL. (Contributed by Skip Montanaro.) * *note tabnanny: 100.: A module/script to check Python source code for ambiguous indentation. (Contributed by Tim Peters.) * ‘UserString’: A base class useful for deriving objects that behave like strings. * *note webbrowser: 129.: A module that provides a platform independent way to launch a web browser on a specific URL. For each platform, various browsers are tried in a specific order. The user can alter which browser is launched by setting the `BROWSER' environment variable. (Originally inspired by Eric S. Raymond’s patch to *note urllib: 11d. which added similar functionality, but the final module comes from code originally implemented by Fred Drake as ‘Tools/idle/BrowserControl.py’, and adapted for the standard library by Fred.) * ‘_winreg’: An interface to the Windows registry. ‘_winreg’ is an adaptation of functions that have been part of PythonWin since 1995, but has now been added to the core distribution, and enhanced to support Unicode. ‘_winreg’ was written by Bill Tutt and Mark Hammond. * *note zipfile: 142.: A module for reading and writing ZIP-format archives. These are archives produced by ‘PKZIP’ on DOS/Windows or ‘zip’ on Unix, not to be confused with ‘gzip’-format files (which are supported by the *note gzip: 8c. module) (Contributed by James C. Ahlstrom.) * ‘imputil’: A module that provides a simpler way for writing customized import hooks, in comparison to the existing ‘ihooks’ module. (Implemented by Greg Stein, with much discussion on python-dev along the way.)  File: python.info, Node: IDLE Improvements, Next: Deleted and Deprecated Modules, Prev: New modules, Up: What’s New in Python 2 0 1.17.16 IDLE Improvements ------------------------- IDLE is the official Python cross-platform IDE, written using Tkinter. Python 2.0 includes IDLE 0.6, which adds a number of new features and improvements. A partial list: * UI improvements and optimizations, especially in the area of syntax highlighting and auto-indentation. * The class browser now shows more information, such as the top level functions in a module. * Tab width is now a user settable option. When opening an existing Python file, IDLE automatically detects the indentation conventions, and adapts. * There is now support for calling browsers on various platforms, used to open the Python documentation in a browser. * IDLE now has a command line, which is largely similar to the vanilla Python interpreter. * Call tips were added in many places. * IDLE can now be installed as a package. * In the editor window, there is now a line/column bar at the bottom. * Three new keystroke commands: Check module (‘Alt-F5’), Import module (‘F5’) and Run script (‘Ctrl-F5’).  File: python.info, Node: Deleted and Deprecated Modules, Next: Acknowledgements<8>, Prev: IDLE Improvements, Up: What’s New in Python 2 0 1.17.17 Deleted and Deprecated Modules -------------------------------------- A few modules have been dropped because they’re obsolete, or because there are now better ways to do the same thing. The ‘stdwin’ module is gone; it was for a platform-independent windowing toolkit that’s no longer developed. A number of modules have been moved to the ‘lib-old’ subdirectory: ‘cmp’, ‘cmpcache’, ‘dircmp’, ‘dump’, ‘find’, ‘grep’, ‘packmail’, ‘poly’, ‘util’, ‘whatsound’, ‘zmod’. If you have code which relies on a module that’s been moved to ‘lib-old’, you can simply add that directory to ‘sys.path’ to get them back, but you’re encouraged to update any code that uses these modules.  File: python.info, Node: Acknowledgements<8>, Prev: Deleted and Deprecated Modules, Up: What’s New in Python 2 0 1.17.18 Acknowledgements ------------------------ The authors would like to thank the following people for offering suggestions on various drafts of this article: David Bolen, Mark Hammond, Gregg Hauser, Jeremy Hylton, Fredrik Lundh, Detlef Lannert, Aahz Maruch, Skip Montanaro, Vladimir Marangozov, Tobias Polzin, Guido van Rossum, Neil Schemenauer, and Russ Schmidt. The “Changelog” is an HTML version of the file built(1) from the contents of the Misc/NEWS.d(2) directory tree, which contains `all' nontrivial changes to Python for the current version. ---------- Footnotes ---------- (1) https://pypi.org/project/blurb (2) https://github.com/python/cpython/tree/3.8/Misc/NEWS.d  File: python.info, Node: Changelog, Prev: What’s New in Python 2 0, Up: What’s New in Python 1.18 Changelog ============== `The NEWS file is not available.'  File: python.info, Node: The Python Tutorial, Next: Python Setup and Usage, Prev: What’s New in Python, Up: Top 2 The Python Tutorial ********************* Python is an easy to learn, powerful programming language. It has efficient high-level data structures and a simple but effective approach to object-oriented programming. Python’s elegant syntax and dynamic typing, together with its interpreted nature, make it an ideal language for scripting and rapid application development in many areas on most platforms. The Python interpreter and the extensive standard library are freely available in source or binary form for all major platforms from the Python Web site, ‘https://www.python.org/’, and may be freely distributed. The same site also contains distributions of and pointers to many free third party Python modules, programs and tools, and additional documentation. The Python interpreter is easily extended with new functions and data types implemented in C or C++ (or other languages callable from C). Python is also suitable as an extension language for customizable applications. This tutorial introduces the reader informally to the basic concepts and features of the Python language and system. It helps to have a Python interpreter handy for hands-on experience, but all examples are self-contained, so the tutorial can be read off-line as well. For a description of standard objects and modules, see *note The Python Standard Library: e8e. *note The Python Language Reference: e8f. gives a more formal definition of the language. To write extensions in C or C++, read *note Extending and Embedding the Python Interpreter: e90. and *note Python/C API Reference Manual: e91. There are also several books covering Python in depth. This tutorial does not attempt to be comprehensive and cover every single feature, or even every commonly used feature. Instead, it introduces many of Python’s most noteworthy features, and will give you a good idea of the language’s flavor and style. After reading it, you will be able to read and write Python modules and programs, and you will be ready to learn more about the various Python library modules described in *note The Python Standard Library: e8e. The *note Glossary: e92. is also worth going through. * Menu: * Whetting Your Appetite:: * Using the Python Interpreter:: * An Informal Introduction to Python:: * More Control Flow Tools:: * Data Structures:: * Modules:: * Input and Output:: * Errors and Exceptions:: * Classes:: * Brief Tour of the Standard Library:: * Brief Tour of the Standard Library — Part II:: * Virtual Environments and Packages:: * What Now?:: * Interactive Input Editing and History Substitution:: * Floating Point Arithmetic; Issues and Limitations: Floating Point Arithmetic Issues and Limitations. * Appendix::  File: python.info, Node: Whetting Your Appetite, Next: Using the Python Interpreter, Up: The Python Tutorial 2.1 Whetting Your Appetite ========================== If you do much work on computers, eventually you find that there’s some task you’d like to automate. For example, you may wish to perform a search-and-replace over a large number of text files, or rename and rearrange a bunch of photo files in a complicated way. Perhaps you’d like to write a small custom database, or a specialized GUI application, or a simple game. If you’re a professional software developer, you may have to work with several C/C++/Java libraries but find the usual write/compile/test/re-compile cycle is too slow. Perhaps you’re writing a test suite for such a library and find writing the testing code a tedious task. Or maybe you’ve written a program that could use an extension language, and you don’t want to design and implement a whole new language for your application. Python is just the language for you. You could write a Unix shell script or Windows batch files for some of these tasks, but shell scripts are best at moving around files and changing text data, not well-suited for GUI applications or games. You could write a C/C++/Java program, but it can take a lot of development time to get even a first-draft program. Python is simpler to use, available on Windows, Mac OS X, and Unix operating systems, and will help you get the job done more quickly. Python is simple to use, but it is a real programming language, offering much more structure and support for large programs than shell scripts or batch files can offer. On the other hand, Python also offers much more error checking than C, and, being a `very-high-level language', it has high-level data types built in, such as flexible arrays and dictionaries. Because of its more general data types Python is applicable to a much larger problem domain than Awk or even Perl, yet many things are at least as easy in Python as in those languages. Python allows you to split your program into modules that can be reused in other Python programs. It comes with a large collection of standard modules that you can use as the basis of your programs — or as examples to start learning to program in Python. Some of these modules provide things like file I/O, system calls, sockets, and even interfaces to graphical user interface toolkits like Tk. Python is an interpreted language, which can save you considerable time during program development because no compilation and linking is necessary. The interpreter can be used interactively, which makes it easy to experiment with features of the language, to write throw-away programs, or to test functions during bottom-up program development. It is also a handy desk calculator. Python enables programs to be written compactly and readably. Programs written in Python are typically much shorter than equivalent C, C++, or Java programs, for several reasons: * the high-level data types allow you to express complex operations in a single statement; * statement grouping is done by indentation instead of beginning and ending brackets; * no variable or argument declarations are necessary. Python is `extensible': if you know how to program in C it is easy to add a new built-in function or module to the interpreter, either to perform critical operations at maximum speed, or to link Python programs to libraries that may only be available in binary form (such as a vendor-specific graphics library). Once you are really hooked, you can link the Python interpreter into an application written in C and use it as an extension or command language for that application. By the way, the language is named after the BBC show “Monty Python’s Flying Circus” and has nothing to do with reptiles. Making references to Monty Python skits in documentation is not only allowed, it is encouraged! Now that you are all excited about Python, you’ll want to examine it in some more detail. Since the best way to learn a language is to use it, the tutorial invites you to play with the Python interpreter as you read. In the next chapter, the mechanics of using the interpreter are explained. This is rather mundane information, but essential for trying out the examples shown later. The rest of the tutorial introduces various features of the Python language and system through examples, beginning with simple expressions, statements and data types, through functions and modules, and finally touching upon advanced concepts like exceptions and user-defined classes.  File: python.info, Node: Using the Python Interpreter, Next: An Informal Introduction to Python, Prev: Whetting Your Appetite, Up: The Python Tutorial 2.2 Using the Python Interpreter ================================ * Menu: * Invoking the Interpreter:: * The Interpreter and Its Environment::  File: python.info, Node: Invoking the Interpreter, Next: The Interpreter and Its Environment, Up: Using the Python Interpreter 2.2.1 Invoking the Interpreter ------------------------------ The Python interpreter is usually installed as ‘/usr/local/bin/python3.8’ on those machines where it is available; putting ‘/usr/local/bin’ in your Unix shell’s search path makes it possible to start it by typing the command: python3.8 to the shell. (1) Since the choice of the directory where the interpreter lives is an installation option, other places are possible; check with your local Python guru or system administrator. (E.g., ‘/usr/local/python’ is a popular alternative location.) On Windows machines where you have installed Python from the *note Microsoft Store: e9b, the ‘python3.8’ command will be available. If you have the *note py.exe launcher: 98f. installed, you can use the ‘py’ command. See *note Excursus; Setting environment variables: e9c. for other ways to launch Python. Typing an end-of-file character (‘Control-D’ on Unix, ‘Control-Z’ on Windows) at the primary prompt causes the interpreter to exit with a zero exit status. If that doesn’t work, you can exit the interpreter by typing the following command: ‘quit()’. The interpreter’s line-editing features include interactive editing, history substitution and code completion on systems that support the GNU Readline(2) library. Perhaps the quickest check to see whether command line editing is supported is typing ‘Control-P’ to the first Python prompt you get. If it beeps, you have command line editing; see Appendix *note Interactive Input Editing and History Substitution: e9d. for an introduction to the keys. If nothing appears to happen, or if ‘^P’ is echoed, command line editing isn’t available; you’ll only be able to use backspace to remove characters from the current line. The interpreter operates somewhat like the Unix shell: when called with standard input connected to a tty device, it reads and executes commands interactively; when called with a file name argument or with a file as standard input, it reads and executes a `script' from that file. A second way of starting the interpreter is ‘python -c command [arg] ...’, which executes the statement(s) in `command', analogous to the shell’s *note -c: e9e. option. Since Python statements often contain spaces or other characters that are special to the shell, it is usually advised to quote `command' in its entirety with single quotes. Some Python modules are also useful as scripts. These can be invoked using ‘python -m module [arg] ...’, which executes the source file for `module' as if you had spelled out its full name on the command line. When a script file is used, it is sometimes useful to be able to run the script and enter interactive mode afterwards. This can be done by passing *note -i: e1f. before the script. All command line options are described in *note Command line and environment: e9f. * Menu: * Argument Passing:: * Interactive Mode:: ---------- Footnotes ---------- (1) (1) On Unix, the Python 3.x interpreter is by default not installed with the executable named ‘python’, so that it does not conflict with a simultaneously installed Python 2.x executable. (2) https://tiswww.case.edu/php/chet/readline/rltop.html  File: python.info, Node: Argument Passing, Next: Interactive Mode, Up: Invoking the Interpreter 2.2.1.1 Argument Passing ........................ When known to the interpreter, the script name and additional arguments thereafter are turned into a list of strings and assigned to the ‘argv’ variable in the ‘sys’ module. You can access this list by executing ‘import sys’. The length of the list is at least one; when no script and no arguments are given, ‘sys.argv[0]’ is an empty string. When the script name is given as ‘'-'’ (meaning standard input), ‘sys.argv[0]’ is set to ‘'-'’. When *note -c: e9e. `command' is used, ‘sys.argv[0]’ is set to ‘'-c'’. When *note -m: 337. `module' is used, ‘sys.argv[0]’ is set to the full name of the located module. Options found after *note -c: e9e. `command' or *note -m: 337. `module' are not consumed by the Python interpreter’s option processing but left in ‘sys.argv’ for the command or module to handle.  File: python.info, Node: Interactive Mode, Prev: Argument Passing, Up: Invoking the Interpreter 2.2.1.2 Interactive Mode ........................ When commands are read from a tty, the interpreter is said to be in `interactive mode'. In this mode it prompts for the next command with the `primary prompt', usually three greater-than signs (‘>>>’); for continuation lines it prompts with the `secondary prompt', by default three dots (‘...’). The interpreter prints a welcome message stating its version number and a copyright notice before printing the first prompt: $ python3.8 Python 3.8 (default, Sep 16 2015, 09:25:04) [GCC 4.8.2] on linux Type "help", "copyright", "credits" or "license" for more information. >>> Continuation lines are needed when entering a multi-line construct. As an example, take a look at this *note if: de7. statement: >>> the_world_is_flat = True >>> if the_world_is_flat: ... print("Be careful not to fall off!") ... Be careful not to fall off! For more on interactive mode, see *note Interactive Mode: ea3.  File: python.info, Node: The Interpreter and Its Environment, Prev: Invoking the Interpreter, Up: Using the Python Interpreter 2.2.2 The Interpreter and Its Environment ----------------------------------------- * Menu: * Source Code Encoding::  File: python.info, Node: Source Code Encoding, Up: The Interpreter and Its Environment 2.2.2.1 Source Code Encoding ............................ By default, Python source files are treated as encoded in UTF-8. In that encoding, characters of most languages in the world can be used simultaneously in string literals, identifiers and comments — although the standard library only uses ASCII characters for identifiers, a convention that any portable code should follow. To display all these characters properly, your editor must recognize that the file is UTF-8, and it must use a font that supports all the characters in the file. To declare an encoding other than the default one, a special comment line should be added as the `first' line of the file. The syntax is as follows: # -*- coding: encoding -*- where `encoding' is one of the valid *note codecs: 1c. supported by Python. For example, to declare that Windows-1252 encoding is to be used, the first line of your source code file should be: # -*- coding: cp1252 -*- One exception to the `first line' rule is when the source code starts with a *note UNIX “shebang” line: ea8. In this case, the encoding declaration should be added as the second line of the file. For example: #!/usr/bin/env python3 # -*- coding: cp1252 -*-  File: python.info, Node: An Informal Introduction to Python, Next: More Control Flow Tools, Prev: Using the Python Interpreter, Up: The Python Tutorial 2.3 An Informal Introduction to Python ====================================== In the following examples, input and output are distinguished by the presence or absence of prompts (*note >>>: eac. and *note …: ead.): to repeat the example, you must type everything after the prompt, when the prompt appears; lines that do not begin with a prompt are output from the interpreter. Note that a secondary prompt on a line by itself in an example means you must type a blank line; this is used to end a multi-line command. Many of the examples in this manual, even those entered at the interactive prompt, include comments. Comments in Python start with the hash character, ‘#’, and extend to the end of the physical line. A comment may appear at the start of a line or following whitespace or code, but not within a string literal. A hash character within a string literal is just a hash character. Since comments are to clarify code and are not interpreted by Python, they may be omitted when typing in examples. Some examples: # this is the first comment spam = 1 # and this is the second comment # ... and now a third! text = "# This is not a comment because it's inside quotes." * Menu: * Using Python as a Calculator:: * First Steps Towards Programming::  File: python.info, Node: Using Python as a Calculator, Next: First Steps Towards Programming, Up: An Informal Introduction to Python 2.3.1 Using Python as a Calculator ---------------------------------- Let’s try some simple Python commands. Start the interpreter and wait for the primary prompt, ‘>>>’. (It shouldn’t take long.) * Menu: * Numbers:: * Strings:: * Lists::  File: python.info, Node: Numbers, Next: Strings, Up: Using Python as a Calculator 2.3.1.1 Numbers ............... The interpreter acts as a simple calculator: you can type an expression at it and it will write the value. Expression syntax is straightforward: the operators ‘+’, ‘-’, ‘*’ and ‘/’ work just like in most other languages (for example, Pascal or C); parentheses (‘()’) can be used for grouping. For example: >>> 2 + 2 4 >>> 50 - 5*6 20 >>> (50 - 5*6) / 4 5.0 >>> 8 / 5 # division always returns a floating point number 1.6 The integer numbers (e.g. ‘2’, ‘4’, ‘20’) have type *note int: 184, the ones with a fractional part (e.g. ‘5.0’, ‘1.6’) have type *note float: 187. We will see more about numeric types later in the tutorial. Division (‘/’) always returns a float. To do *note floor division: eb2. and get an integer result (discarding any fractional result) you can use the ‘//’ operator; to calculate the remainder you can use ‘%’: >>> 17 / 3 # classic division returns a float 5.666666666666667 >>> >>> 17 // 3 # floor division discards the fractional part 5 >>> 17 % 3 # the % operator returns the remainder of the division 2 >>> 5 * 3 + 2 # result * divisor + remainder 17 With Python, it is possible to use the ‘**’ operator to calculate powers (1): >>> 5 ** 2 # 5 squared 25 >>> 2 ** 7 # 2 to the power of 7 128 The equal sign (‘=’) is used to assign a value to a variable. Afterwards, no result is displayed before the next interactive prompt: >>> width = 20 >>> height = 5 * 9 >>> width * height 900 If a variable is not “defined” (assigned a value), trying to use it will give you an error: >>> n # try to access an undefined variable Traceback (most recent call last): File "", line 1, in NameError: name 'n' is not defined There is full support for floating point; operators with mixed type operands convert the integer operand to floating point: >>> 4 * 3.75 - 1 14.0 In interactive mode, the last printed expression is assigned to the variable ‘_’. This means that when you are using Python as a desk calculator, it is somewhat easier to continue calculations, for example: >>> tax = 12.5 / 100 >>> price = 100.50 >>> price * tax 12.5625 >>> price + _ 113.0625 >>> round(_, 2) 113.06 This variable should be treated as read-only by the user. Don’t explicitly assign a value to it — you would create an independent local variable with the same name masking the built-in variable with its magic behavior. In addition to *note int: 184. and *note float: 187, Python supports other types of numbers, such as *note Decimal: 188. and *note Fraction: 185. Python also has built-in support for *note complex numbers: eb3, and uses the ‘j’ or ‘J’ suffix to indicate the imaginary part (e.g. ‘3+5j’). ---------- Footnotes ---------- (1) (1) Since ‘**’ has higher precedence than ‘-’, ‘-3**2’ will be interpreted as ‘-(3**2)’ and thus result in ‘-9’. To avoid this and get ‘9’, you can use ‘(-3)**2’.  File: python.info, Node: Strings, Next: Lists, Prev: Numbers, Up: Using Python as a Calculator 2.3.1.2 Strings ............... Besides numbers, Python can also manipulate strings, which can be expressed in several ways. They can be enclosed in single quotes (‘'...'’) or double quotes (‘"..."’) with the same result (1). ‘\’ can be used to escape quotes: >>> 'spam eggs' # single quotes 'spam eggs' >>> 'doesn\'t' # use \' to escape the single quote... "doesn't" >>> "doesn't" # ...or use double quotes instead "doesn't" >>> '"Yes," they said.' '"Yes," they said.' >>> "\"Yes,\" they said." '"Yes," they said.' >>> '"Isn\'t," they said.' '"Isn\'t," they said.' In the interactive interpreter, the output string is enclosed in quotes and special characters are escaped with backslashes. While this might sometimes look different from the input (the enclosing quotes could change), the two strings are equivalent. The string is enclosed in double quotes if the string contains a single quote and no double quotes, otherwise it is enclosed in single quotes. The *note print(): 886. function produces a more readable output, by omitting the enclosing quotes and by printing escaped and special characters: >>> '"Isn\'t," they said.' '"Isn\'t," they said.' >>> print('"Isn\'t," they said.') "Isn't," they said. >>> s = 'First line.\nSecond line.' # \n means newline >>> s # without print(), \n is included in the output 'First line.\nSecond line.' >>> print(s) # with print(), \n produces a new line First line. Second line. If you don’t want characters prefaced by ‘\’ to be interpreted as special characters, you can use `raw strings' by adding an ‘r’ before the first quote: >>> print('C:\some\name') # here \n means newline! C:\some ame >>> print(r'C:\some\name') # note the r before the quote C:\some\name String literals can span multiple lines. One way is using triple-quotes: ‘"""..."""’ or ‘'''...'''’. End of lines are automatically included in the string, but it’s possible to prevent this by adding a ‘\’ at the end of the line. The following example: print("""\ Usage: thingy [OPTIONS] -h Display this usage message -H hostname Hostname to connect to """) produces the following output (note that the initial newline is not included): Usage: thingy [OPTIONS] -h Display this usage message -H hostname Hostname to connect to Strings can be concatenated (glued together) with the ‘+’ operator, and repeated with ‘*’: >>> # 3 times 'un', followed by 'ium' >>> 3 * 'un' + 'ium' 'unununium' Two or more `string literals' (i.e. the ones enclosed between quotes) next to each other are automatically concatenated. >>> 'Py' 'thon' 'Python' This feature is particularly useful when you want to break long strings: >>> text = ('Put several strings within parentheses ' ... 'to have them joined together.') >>> text 'Put several strings within parentheses to have them joined together.' This only works with two literals though, not with variables or expressions: >>> prefix = 'Py' >>> prefix 'thon' # can't concatenate a variable and a string literal File "", line 1 prefix 'thon' ^ SyntaxError: invalid syntax >>> ('un' * 3) 'ium' File "", line 1 ('un' * 3) 'ium' ^ SyntaxError: invalid syntax If you want to concatenate variables or a variable and a literal, use ‘+’: >>> prefix + 'thon' 'Python' Strings can be `indexed' (subscripted), with the first character having index 0. There is no separate character type; a character is simply a string of size one: >>> word = 'Python' >>> word[0] # character in position 0 'P' >>> word[5] # character in position 5 'n' Indices may also be negative numbers, to start counting from the right: >>> word[-1] # last character 'n' >>> word[-2] # second-last character 'o' >>> word[-6] 'P' Note that since -0 is the same as 0, negative indices start from -1. In addition to indexing, `slicing' is also supported. While indexing is used to obtain individual characters, `slicing' allows you to obtain substring: >>> word[0:2] # characters from position 0 (included) to 2 (excluded) 'Py' >>> word[2:5] # characters from position 2 (included) to 5 (excluded) 'tho' Note how the start is always included, and the end always excluded. This makes sure that ‘s[:i] + s[i:]’ is always equal to ‘s’: >>> word[:2] + word[2:] 'Python' >>> word[:4] + word[4:] 'Python' Slice indices have useful defaults; an omitted first index defaults to zero, an omitted second index defaults to the size of the string being sliced. >>> word[:2] # character from the beginning to position 2 (excluded) 'Py' >>> word[4:] # characters from position 4 (included) to the end 'on' >>> word[-2:] # characters from the second-last (included) to the end 'on' One way to remember how slices work is to think of the indices as pointing `between' characters, with the left edge of the first character numbered 0. Then the right edge of the last character of a string of `n' characters has index `n', for example: +---+---+---+---+---+---+ | P | y | t | h | o | n | +---+---+---+---+---+---+ 0 1 2 3 4 5 6 -6 -5 -4 -3 -2 -1 The first row of numbers gives the position of the indices 0…6 in the string; the second row gives the corresponding negative indices. The slice from `i' to `j' consists of all characters between the edges labeled `i' and `j', respectively. For non-negative indices, the length of a slice is the difference of the indices, if both are within bounds. For example, the length of ‘word[1:3]’ is 2. Attempting to use an index that is too large will result in an error: >>> word[42] # the word only has 6 characters Traceback (most recent call last): File "", line 1, in IndexError: string index out of range However, out of range slice indexes are handled gracefully when used for slicing: >>> word[4:42] 'on' >>> word[42:] '' Python strings cannot be changed — they are *note immutable: eb6. Therefore, assigning to an indexed position in the string results in an error: >>> word[0] = 'J' Traceback (most recent call last): File "", line 1, in TypeError: 'str' object does not support item assignment >>> word[2:] = 'py' Traceback (most recent call last): File "", line 1, in TypeError: 'str' object does not support item assignment If you need a different string, you should create a new one: >>> 'J' + word[1:] 'Jython' >>> word[:2] + 'py' 'Pypy' The built-in function *note len(): 150. returns the length of a string: >>> s = 'supercalifragilisticexpialidocious' >>> len(s) 34 See also ........ *note Text Sequence Type — str: eb7. Strings are examples of `sequence types', and support the common operations supported by such types. *note String Methods: eb8. Strings support a large number of methods for basic transformations and searching. *note Formatted string literals: 15c. String literals that have embedded expressions. *note Format String Syntax: d1a. Information about string formatting with *note str.format(): 4da. *note printf-style String Formatting: eb9. The old formatting operations invoked when strings are the left operand of the ‘%’ operator are described in more detail here. ---------- Footnotes ---------- (1) (2) Unlike other languages, special characters such as ‘\n’ have the same meaning with both single (‘'...'’) and double (‘"..."’) quotes. The only difference between the two is that within single quotes you don’t need to escape ‘"’ (but you have to escape ‘\'’) and vice versa.  File: python.info, Node: Lists, Prev: Strings, Up: Using Python as a Calculator 2.3.1.3 Lists ............. Python knows a number of `compound' data types, used to group together other values. The most versatile is the `list', which can be written as a list of comma-separated values (items) between square brackets. Lists might contain items of different types, but usually the items all have the same type. >>> squares = [1, 4, 9, 16, 25] >>> squares [1, 4, 9, 16, 25] Like strings (and all other built-in *note sequence: ebc. types), lists can be indexed and sliced: >>> squares[0] # indexing returns the item 1 >>> squares[-1] 25 >>> squares[-3:] # slicing returns a new list [9, 16, 25] All slice operations return a new list containing the requested elements. This means that the following slice returns a *note shallow copy: ebd. of the list: >>> squares[:] [1, 4, 9, 16, 25] Lists also support operations like concatenation: >>> squares + [36, 49, 64, 81, 100] [1, 4, 9, 16, 25, 36, 49, 64, 81, 100] Unlike strings, which are *note immutable: eb6, lists are a *note mutable: ebe. type, i.e. it is possible to change their content: >>> cubes = [1, 8, 27, 65, 125] # something's wrong here >>> 4 ** 3 # the cube of 4 is 64, not 65! 64 >>> cubes[3] = 64 # replace the wrong value >>> cubes [1, 8, 27, 64, 125] You can also add new items at the end of the list, by using the ‘append()’ `method' (we will see more about methods later): >>> cubes.append(216) # add the cube of 6 >>> cubes.append(7 ** 3) # and the cube of 7 >>> cubes [1, 8, 27, 64, 125, 216, 343] Assignment to slices is also possible, and this can even change the size of the list or clear it entirely: >>> letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g'] >>> letters ['a', 'b', 'c', 'd', 'e', 'f', 'g'] >>> # replace some values >>> letters[2:5] = ['C', 'D', 'E'] >>> letters ['a', 'b', 'C', 'D', 'E', 'f', 'g'] >>> # now remove them >>> letters[2:5] = [] >>> letters ['a', 'b', 'f', 'g'] >>> # clear the list by replacing all the elements with an empty list >>> letters[:] = [] >>> letters [] The built-in function *note len(): 150. also applies to lists: >>> letters = ['a', 'b', 'c', 'd'] >>> len(letters) 4 It is possible to nest lists (create lists containing other lists), for example: >>> a = ['a', 'b', 'c'] >>> n = [1, 2, 3] >>> x = [a, n] >>> x [['a', 'b', 'c'], [1, 2, 3]] >>> x[0] ['a', 'b', 'c'] >>> x[0][1] 'b'  File: python.info, Node: First Steps Towards Programming, Prev: Using Python as a Calculator, Up: An Informal Introduction to Python 2.3.2 First Steps Towards Programming ------------------------------------- Of course, we can use Python for more complicated tasks than adding two and two together. For instance, we can write an initial sub-sequence of the Fibonacci series(1) as follows: >>> # Fibonacci series: ... # the sum of two elements defines the next ... a, b = 0, 1 >>> while a < 10: ... print(a) ... a, b = b, a+b ... 0 1 1 2 3 5 8 This example introduces several new features. * The first line contains a `multiple assignment': the variables ‘a’ and ‘b’ simultaneously get the new values 0 and 1. On the last line this is used again, demonstrating that the expressions on the right-hand side are all evaluated first before any of the assignments take place. The right-hand side expressions are evaluated from the left to the right. * The *note while: ec1. loop executes as long as the condition (here: ‘a < 10’) remains true. In Python, like in C, any non-zero integer value is true; zero is false. The condition may also be a string or list value, in fact any sequence; anything with a non-zero length is true, empty sequences are false. The test used in the example is a simple comparison. The standard comparison operators are written the same as in C: ‘<’ (less than), ‘>’ (greater than), ‘==’ (equal to), ‘<=’ (less than or equal to), ‘>=’ (greater than or equal to) and ‘!=’ (not equal to). * The `body' of the loop is `indented': indentation is Python’s way of grouping statements. At the interactive prompt, you have to type a tab or space(s) for each indented line. In practice you will prepare more complicated input for Python with a text editor; all decent text editors have an auto-indent facility. When a compound statement is entered interactively, it must be followed by a blank line to indicate completion (since the parser cannot guess when you have typed the last line). Note that each line within a basic block must be indented by the same amount. * The *note print(): 886. function writes the value of the argument(s) it is given. It differs from just writing the expression you want to write (as we did earlier in the calculator examples) in the way it handles multiple arguments, floating point quantities, and strings. Strings are printed without quotes, and a space is inserted between items, so you can format things nicely, like this: >>> i = 256*256 >>> print('The value of i is', i) The value of i is 65536 The keyword argument `end' can be used to avoid the newline after the output, or end the output with a different string: >>> a, b = 0, 1 >>> while a < 1000: ... print(a, end=',') ... a, b = b, a+b ... 0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987, ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Fibonacci_number  File: python.info, Node: More Control Flow Tools, Next: Data Structures, Prev: An Informal Introduction to Python, Up: The Python Tutorial 2.4 More Control Flow Tools =========================== Besides the *note while: ec1. statement just introduced, Python uses the usual flow control statements known from other languages, with some twists. * Menu: * if Statements:: * for Statements:: * The range() Function: The range Function. * break and continue Statements, and else Clauses on Loops: break and continue Statements and else Clauses on Loops. * pass Statements:: * Defining Functions:: * More on Defining Functions:: * Intermezzo; Coding Style: Intermezzo Coding Style.  File: python.info, Node: if Statements, Next: for Statements, Up: More Control Flow Tools 2.4.1 ‘if’ Statements --------------------- Perhaps the most well-known statement type is the *note if: de7. statement. For example: >>> x = int(input("Please enter an integer: ")) Please enter an integer: 42 >>> if x < 0: ... x = 0 ... print('Negative changed to zero') ... elif x == 0: ... print('Zero') ... elif x == 1: ... print('Single') ... else: ... print('More') ... More There can be zero or more *note elif: ec7. parts, and the *note else: ec8. part is optional. The keyword ‘‘elif’’ is short for ‘else if’, and is useful to avoid excessive indentation. An ‘if’ … ‘elif’ … ‘elif’ … sequence is a substitute for the ‘switch’ or ‘case’ statements found in other languages.  File: python.info, Node: for Statements, Next: The range Function, Prev: if Statements, Up: More Control Flow Tools 2.4.2 ‘for’ Statements ---------------------- The *note for: c30. statement in Python differs a bit from what you may be used to in C or Pascal. Rather than always iterating over an arithmetic progression of numbers (like in Pascal), or giving the user the ability to define both the iteration step and halting condition (as C), Python’s ‘for’ statement iterates over the items of any sequence (a list or a string), in the order that they appear in the sequence. For example (no pun intended): >>> # Measure some strings: ... words = ['cat', 'window', 'defenestrate'] >>> for w in words: ... print(w, len(w)) ... cat 3 window 6 defenestrate 12 Code that modifies a collection while iterating over that same collection can be tricky to get right. Instead, it is usually more straight-forward to loop over a copy of the collection or to create a new collection: # Strategy: Iterate over a copy for user, status in users.copy().items(): if status == 'inactive': del users[user] # Strategy: Create a new collection active_users = {} for user, status in users.items(): if status == 'active': active_users[user] = status  File: python.info, Node: The range Function, Next: break and continue Statements and else Clauses on Loops, Prev: for Statements, Up: More Control Flow Tools 2.4.3 The ‘range()’ Function ---------------------------- If you do need to iterate over a sequence of numbers, the built-in function *note range(): 9be. comes in handy. It generates arithmetic progressions: >>> for i in range(5): ... print(i) ... 0 1 2 3 4 The given end point is never part of the generated sequence; ‘range(10)’ generates 10 values, the legal indices for items of a sequence of length 10. It is possible to let the range start at another number, or to specify a different increment (even negative; sometimes this is called the ‘step’): range(5, 10) 5, 6, 7, 8, 9 range(0, 10, 3) 0, 3, 6, 9 range(-10, -100, -30) -10, -40, -70 To iterate over the indices of a sequence, you can combine *note range(): 9be. and *note len(): 150. as follows: >>> a = ['Mary', 'had', 'a', 'little', 'lamb'] >>> for i in range(len(a)): ... print(i, a[i]) ... 0 Mary 1 had 2 a 3 little 4 lamb In most such cases, however, it is convenient to use the *note enumerate(): de3. function, see *note Looping Techniques: ecd. A strange thing happens if you just print a range: >>> print(range(10)) range(0, 10) In many ways the object returned by *note range(): 9be. behaves as if it is a list, but in fact it isn’t. It is an object which returns the successive items of the desired sequence when you iterate over it, but it doesn’t really make the list, thus saving space. We say such an object is *note iterable: bac, that is, suitable as a target for functions and constructs that expect something from which they can obtain successive items until the supply is exhausted. We have seen that the *note for: c30. statement is such a construct, while an example of a function that takes an iterable is *note sum(): 1e5.: >>> sum(range(4)) # 0 + 1 + 2 + 3 6 Later we will see more functions that return iterables and take iterables as arguments. Lastly, maybe you are curious about how to get a list from a range. Here is the solution: >>> list(range(4)) [0, 1, 2, 3] In chapter *note Data Structures: ece, we will discuss in more detail about *note list(): 262.  File: python.info, Node: break and continue Statements and else Clauses on Loops, Next: pass Statements, Prev: The range Function, Up: More Control Flow Tools 2.4.4 ‘break’ and ‘continue’ Statements, and ‘else’ Clauses on Loops -------------------------------------------------------------------- The *note break: 2db. statement, like in C, breaks out of the innermost enclosing *note for: c30. or *note while: ec1. loop. Loop statements may have an ‘else’ clause; it is executed when the loop terminates through exhaustion of the iterable (with *note for: c30.) or when the condition becomes false (with *note while: ec1.), but not when the loop is terminated by a *note break: 2db. statement. This is exemplified by the following loop, which searches for prime numbers: >>> for n in range(2, 10): ... for x in range(2, n): ... if n % x == 0: ... print(n, 'equals', x, '*', n//x) ... break ... else: ... # loop fell through without finding a factor ... print(n, 'is a prime number') ... 2 is a prime number 3 is a prime number 4 equals 2 * 2 5 is a prime number 6 equals 2 * 3 7 is a prime number 8 equals 2 * 4 9 equals 3 * 3 (Yes, this is the correct code. Look closely: the ‘else’ clause belongs to the *note for: c30. loop, `not' the *note if: de7. statement.) When used with a loop, the ‘else’ clause has more in common with the ‘else’ clause of a *note try: d72. statement than it does with that of *note if: de7. statements: a *note try: d72. statement’s ‘else’ clause runs when no exception occurs, and a loop’s ‘else’ clause runs when no ‘break’ occurs. For more on the ‘try’ statement and exceptions, see *note Handling Exceptions: ed1. The *note continue: 181. statement, also borrowed from C, continues with the next iteration of the loop: >>> for num in range(2, 10): ... if num % 2 == 0: ... print("Found an even number", num) ... continue ... print("Found an odd number", num) Found an even number 2 Found an odd number 3 Found an even number 4 Found an odd number 5 Found an even number 6 Found an odd number 7 Found an even number 8 Found an odd number 9  File: python.info, Node: pass Statements, Next: Defining Functions, Prev: break and continue Statements and else Clauses on Loops, Up: More Control Flow Tools 2.4.5 ‘pass’ Statements ----------------------- The *note pass: ed4. statement does nothing. It can be used when a statement is required syntactically but the program requires no action. For example: >>> while True: ... pass # Busy-wait for keyboard interrupt (Ctrl+C) ... This is commonly used for creating minimal classes: >>> class MyEmptyClass: ... pass ... Another place *note pass: ed4. can be used is as a place-holder for a function or conditional body when you are working on new code, allowing you to keep thinking at a more abstract level. The ‘pass’ is silently ignored: >>> def initlog(*args): ... pass # Remember to implement this! ...  File: python.info, Node: Defining Functions, Next: More on Defining Functions, Prev: pass Statements, Up: More Control Flow Tools 2.4.6 Defining Functions ------------------------ We can create a function that writes the Fibonacci series to an arbitrary boundary: >>> def fib(n): # write Fibonacci series up to n ... """Print a Fibonacci series up to n.""" ... a, b = 0, 1 ... while a < n: ... print(a, end=' ') ... a, b = b, a+b ... print() ... >>> # Now call the function we just defined: ... fib(2000) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 The keyword *note def: dbe. introduces a function `definition'. It must be followed by the function name and the parenthesized list of formal parameters. The statements that form the body of the function start at the next line, and must be indented. The first statement of the function body can optionally be a string literal; this string literal is the function’s documentation string, or `docstring'. (More about docstrings can be found in the section *note Documentation Strings: ed7.) There are tools which use docstrings to automatically produce online or printed documentation, or to let the user interactively browse through code; it’s good practice to include docstrings in code that you write, so make a habit of it. The `execution' of a function introduces a new symbol table used for the local variables of the function. More precisely, all variable assignments in a function store the value in the local symbol table; whereas variable references first look in the local symbol table, then in the local symbol tables of enclosing functions, then in the global symbol table, and finally in the table of built-in names. Thus, global variables and variables of enclosing functions cannot be directly assigned a value within a function (unless, for global variables, named in a *note global: ed8. statement, or, for variables of enclosing functions, named in a *note nonlocal: c3f. statement), although they may be referenced. The actual parameters (arguments) to a function call are introduced in the local symbol table of the called function when it is called; thus, arguments are passed using `call by value' (where the `value' is always an object `reference', not the value of the object). (1) When a function calls another function, or calls itself recursively, a new local symbol table is created for that call. A function definition associates the function name with the function object in the current symbol table. The interpreter recognizes the object pointed to by that name as a user-defined function. Other names can also point to that same function object and can also be used to access the function: >>> fib >>> f = fib >>> f(100) 0 1 1 2 3 5 8 13 21 34 55 89 Coming from other languages, you might object that ‘fib’ is not a function but a procedure since it doesn’t return a value. In fact, even functions without a *note return: 190. statement do return a value, albeit a rather boring one. This value is called ‘None’ (it’s a built-in name). Writing the value ‘None’ is normally suppressed by the interpreter if it would be the only value written. You can see it if you really want to using *note print(): 886.: >>> fib(0) >>> print(fib(0)) None It is simple to write a function that returns a list of the numbers of the Fibonacci series, instead of printing it: >>> def fib2(n): # return Fibonacci series up to n ... """Return a list containing the Fibonacci series up to n.""" ... result = [] ... a, b = 0, 1 ... while a < n: ... result.append(a) # see below ... a, b = b, a+b ... return result ... >>> f100 = fib2(100) # call it >>> f100 # write the result [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] This example, as usual, demonstrates some new Python features: * The *note return: 190. statement returns with a value from a function. ‘return’ without an expression argument returns ‘None’. Falling off the end of a function also returns ‘None’. * The statement ‘result.append(a)’ calls a `method' of the list object ‘result’. A method is a function that ‘belongs’ to an object and is named ‘obj.methodname’, where ‘obj’ is some object (this may be an expression), and ‘methodname’ is the name of a method that is defined by the object’s type. Different types define different methods. Methods of different types may have the same name without causing ambiguity. (It is possible to define your own object types and methods, using `classes', see *note Classes: ed9.) The method ‘append()’ shown in the example is defined for list objects; it adds a new element at the end of the list. In this example it is equivalent to ‘result = result + [a]’, but more efficient. ---------- Footnotes ---------- (1) (1) Actually, `call by object reference' would be a better description, since if a mutable object is passed, the caller will see any changes the callee makes to it (items inserted into a list).  File: python.info, Node: More on Defining Functions, Next: Intermezzo Coding Style, Prev: Defining Functions, Up: More Control Flow Tools 2.4.7 More on Defining Functions -------------------------------- It is also possible to define functions with a variable number of arguments. There are three forms, which can be combined. * Menu: * Default Argument Values:: * Keyword Arguments:: * Special parameters:: * Arbitrary Argument Lists:: * Unpacking Argument Lists:: * Lambda Expressions:: * Documentation Strings:: * Function Annotations::  File: python.info, Node: Default Argument Values, Next: Keyword Arguments, Up: More on Defining Functions 2.4.7.1 Default Argument Values ............................... The most useful form is to specify a default value for one or more arguments. This creates a function that can be called with fewer arguments than it is defined to allow. For example: def ask_ok(prompt, retries=4, reminder='Please try again!'): while True: ok = input(prompt) if ok in ('y', 'ye', 'yes'): return True if ok in ('n', 'no', 'nop', 'nope'): return False retries = retries - 1 if retries < 0: raise ValueError('invalid user response') print(reminder) This function can be called in several ways: * giving only the mandatory argument: ‘ask_ok('Do you really want to quit?')’ * giving one of the optional arguments: ‘ask_ok('OK to overwrite the file?', 2)’ * or even giving all arguments: ‘ask_ok('OK to overwrite the file?', 2, 'Come on, only yes or no!')’ This example also introduces the *note in: 7a3. keyword. This tests whether or not a sequence contains a certain value. The default values are evaluated at the point of function definition in the `defining' scope, so that i = 5 def f(arg=i): print(arg) i = 6 f() will print ‘5’. `Important warning:' The default value is evaluated only once. This makes a difference when the default is a mutable object such as a list, dictionary, or instances of most classes. For example, the following function accumulates the arguments passed to it on subsequent calls: def f(a, L=[]): L.append(a) return L print(f(1)) print(f(2)) print(f(3)) This will print [1] [1, 2] [1, 2, 3] If you don’t want the default to be shared between subsequent calls, you can write the function like this instead: def f(a, L=None): if L is None: L = [] L.append(a) return L  File: python.info, Node: Keyword Arguments, Next: Special parameters, Prev: Default Argument Values, Up: More on Defining Functions 2.4.7.2 Keyword Arguments ......................... Functions can also be called using *note keyword arguments: 5c4. of the form ‘kwarg=value’. For instance, the following function: def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'): print("-- This parrot wouldn't", action, end=' ') print("if you put", voltage, "volts through it.") print("-- Lovely plumage, the", type) print("-- It's", state, "!") accepts one required argument (‘voltage’) and three optional arguments (‘state’, ‘action’, and ‘type’). This function can be called in any of the following ways: parrot(1000) # 1 positional argument parrot(voltage=1000) # 1 keyword argument parrot(voltage=1000000, action='VOOOOOM') # 2 keyword arguments parrot(action='VOOOOOM', voltage=1000000) # 2 keyword arguments parrot('a million', 'bereft of life', 'jump') # 3 positional arguments parrot('a thousand', state='pushing up the daisies') # 1 positional, 1 keyword but all the following calls would be invalid: parrot() # required argument missing parrot(voltage=5.0, 'dead') # non-keyword argument after a keyword argument parrot(110, voltage=220) # duplicate value for the same argument parrot(actor='John Cleese') # unknown keyword argument In a function call, keyword arguments must follow positional arguments. All the keyword arguments passed must match one of the arguments accepted by the function (e.g. ‘actor’ is not a valid argument for the ‘parrot’ function), and their order is not important. This also includes non-optional arguments (e.g. ‘parrot(voltage=1000)’ is valid too). No argument may receive a value more than once. Here’s an example that fails due to this restriction: >>> def function(a): ... pass ... >>> function(0, a=0) Traceback (most recent call last): File "", line 1, in TypeError: function() got multiple values for keyword argument 'a' When a final formal parameter of the form ‘**name’ is present, it receives a dictionary (see *note Mapping Types — dict: 2fc.) containing all keyword arguments except for those corresponding to a formal parameter. This may be combined with a formal parameter of the form ‘*name’ (described in the next subsection) which receives a *note tuple: ee0. containing the positional arguments beyond the formal parameter list. (‘*name’ must occur before ‘**name’.) For example, if we define a function like this: def cheeseshop(kind, *arguments, **keywords): print("-- Do you have any", kind, "?") print("-- I'm sorry, we're all out of", kind) for arg in arguments: print(arg) print("-" * 40) for kw in keywords: print(kw, ":", keywords[kw]) It could be called like this: cheeseshop("Limburger", "It's very runny, sir.", "It's really very, VERY runny, sir.", shopkeeper="Michael Palin", client="John Cleese", sketch="Cheese Shop Sketch") and of course it would print: -- Do you have any Limburger ? -- I'm sorry, we're all out of Limburger It's very runny, sir. It's really very, VERY runny, sir. ---------------------------------------- shopkeeper : Michael Palin client : John Cleese sketch : Cheese Shop Sketch Note that the order in which the keyword arguments are printed is guaranteed to match the order in which they were provided in the function call.  File: python.info, Node: Special parameters, Next: Arbitrary Argument Lists, Prev: Keyword Arguments, Up: More on Defining Functions 2.4.7.3 Special parameters .......................... By default, arguments may be passed to a Python function either by position or explicitly by keyword. For readability and performance, it makes sense to restrict the way arguments can be passed so that a developer need only look at the function definition to determine if items are passed by position, by position or keyword, or by keyword. A function definition may look like: def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2): ----------- ---------- ---------- | | | | Positional or keyword | | - Keyword only -- Positional only where ‘/’ and ‘*’ are optional. If used, these symbols indicate the kind of parameter by how the arguments may be passed to the function: positional-only, positional-or-keyword, and keyword-only. Keyword parameters are also referred to as named parameters. * Menu: * Positional-or-Keyword Arguments:: * Positional-Only Parameters:: * Keyword-Only Arguments:: * Function Examples:: * Recap::  File: python.info, Node: Positional-or-Keyword Arguments, Next: Positional-Only Parameters, Up: Special parameters 2.4.7.4 Positional-or-Keyword Arguments ....................................... If ‘/’ and ‘*’ are not present in the function definition, arguments may be passed to a function by position or by keyword.  File: python.info, Node: Positional-Only Parameters, Next: Keyword-Only Arguments, Prev: Positional-or-Keyword Arguments, Up: Special parameters 2.4.7.5 Positional-Only Parameters .................................. Looking at this in a bit more detail, it is possible to mark certain parameters as `positional-only'. If `positional-only', the parameters’ order matters, and the parameters cannot be passed by keyword. Positional-only parameters are placed before a ‘/’ (forward-slash). The ‘/’ is used to logically separate the positional-only parameters from the rest of the parameters. If there is no ‘/’ in the function definition, there are no positional-only parameters. Parameters following the ‘/’ may be `positional-or-keyword' or `keyword-only'.  File: python.info, Node: Keyword-Only Arguments, Next: Function Examples, Prev: Positional-Only Parameters, Up: Special parameters 2.4.7.6 Keyword-Only Arguments .............................. To mark parameters as `keyword-only', indicating the parameters must be passed by keyword argument, place an ‘*’ in the arguments list just before the first `keyword-only' parameter.  File: python.info, Node: Function Examples, Next: Recap, Prev: Keyword-Only Arguments, Up: Special parameters 2.4.7.7 Function Examples ......................... Consider the following example function definitions paying close attention to the markers ‘/’ and ‘*’: >>> def standard_arg(arg): ... print(arg) ... >>> def pos_only_arg(arg, /): ... print(arg) ... >>> def kwd_only_arg(*, arg): ... print(arg) ... >>> def combined_example(pos_only, /, standard, *, kwd_only): ... print(pos_only, standard, kwd_only) The first function definition, ‘standard_arg’, the most familiar form, places no restrictions on the calling convention and arguments may be passed by position or keyword: >>> standard_arg(2) 2 >>> standard_arg(arg=2) 2 The second function ‘pos_only_arg’ is restricted to only use positional parameters as there is a ‘/’ in the function definition: >>> pos_only_arg(1) 1 >>> pos_only_arg(arg=1) Traceback (most recent call last): File "", line 1, in TypeError: pos_only_arg() got an unexpected keyword argument 'arg' The third function ‘kwd_only_args’ only allows keyword arguments as indicated by a ‘*’ in the function definition: >>> kwd_only_arg(3) Traceback (most recent call last): File "", line 1, in TypeError: kwd_only_arg() takes 0 positional arguments but 1 was given >>> kwd_only_arg(arg=3) 3 And the last uses all three calling conventions in the same function definition: >>> combined_example(1, 2, 3) Traceback (most recent call last): File "", line 1, in TypeError: combined_example() takes 2 positional arguments but 3 were given >>> combined_example(1, 2, kwd_only=3) 1 2 3 >>> combined_example(1, standard=2, kwd_only=3) 1 2 3 >>> combined_example(pos_only=1, standard=2, kwd_only=3) Traceback (most recent call last): File "", line 1, in TypeError: combined_example() got an unexpected keyword argument 'pos_only' Finally, consider this function definition which has a potential collision between the positional argument ‘name’ and ‘**kwds’ which has ‘name’ as a key: def foo(name, **kwds): return 'name' in kwds There is no possible call that will make it return ‘True’ as the keyword ‘'name'’ will always bind to the first parameter. For example: >>> foo(1, **{'name': 2}) Traceback (most recent call last): File "", line 1, in TypeError: foo() got multiple values for argument 'name' >>> But using ‘/’ (positional only arguments), it is possible since it allows ‘name’ as a positional argument and ‘'name'’ as a key in the keyword arguments: def foo(name, /, **kwds): return 'name' in kwds >>> foo(1, **{'name': 2}) True In other words, the names of positional-only parameters can be used in ‘**kwds’ without ambiguity.  File: python.info, Node: Recap, Prev: Function Examples, Up: Special parameters 2.4.7.8 Recap ............. The use case will determine which parameters to use in the function definition: def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2): As guidance: * Use positional-only if you want the name of the parameters to not be available to the user. This is useful when parameter names have no real meaning, if you want to enforce the order of the arguments when the function is called or if you need to take some positional parameters and arbitrary keywords. * Use keyword-only when names have meaning and the function definition is more understandable by being explicit with names or you want to prevent users relying on the position of the argument being passed. * For an API, use positional-only to prevent breaking API changes if the parameter’s name is modified in the future.  File: python.info, Node: Arbitrary Argument Lists, Next: Unpacking Argument Lists, Prev: Special parameters, Up: More on Defining Functions 2.4.7.9 Arbitrary Argument Lists ................................ Finally, the least frequently used option is to specify that a function can be called with an arbitrary number of arguments. These arguments will be wrapped up in a tuple (see *note Tuples and Sequences: ee0.). Before the variable number of arguments, zero or more normal arguments may occur. def write_multiple_items(file, separator, *args): file.write(separator.join(args)) Normally, these ‘variadic’ arguments will be last in the list of formal parameters, because they scoop up all remaining input arguments that are passed to the function. Any formal parameters which occur after the ‘*args’ parameter are ‘keyword-only’ arguments, meaning that they can only be used as keywords rather than positional arguments. >>> def concat(*args, sep="/"): ... return sep.join(args) ... >>> concat("earth", "mars", "venus") 'earth/mars/venus' >>> concat("earth", "mars", "venus", sep=".") 'earth.mars.venus'  File: python.info, Node: Unpacking Argument Lists, Next: Lambda Expressions, Prev: Arbitrary Argument Lists, Up: More on Defining Functions 2.4.7.10 Unpacking Argument Lists ................................. The reverse situation occurs when the arguments are already in a list or tuple but need to be unpacked for a function call requiring separate positional arguments. For instance, the built-in *note range(): 9be. function expects separate `start' and `stop' arguments. If they are not available separately, write the function call with the ‘*’-operator to unpack the arguments out of a list or tuple: >>> list(range(3, 6)) # normal call with separate arguments [3, 4, 5] >>> args = [3, 6] >>> list(range(*args)) # call with arguments unpacked from a list [3, 4, 5] In the same fashion, dictionaries can deliver keyword arguments with the ‘**’-operator: >>> def parrot(voltage, state='a stiff', action='voom'): ... print("-- This parrot wouldn't", action, end=' ') ... print("if you put", voltage, "volts through it.", end=' ') ... print("E's", state, "!") ... >>> d = {"voltage": "four million", "state": "bleedin' demised", "action": "VOOM"} >>> parrot(**d) -- This parrot wouldn't VOOM if you put four million volts through it. E's bleedin' demised !  File: python.info, Node: Lambda Expressions, Next: Documentation Strings, Prev: Unpacking Argument Lists, Up: More on Defining Functions 2.4.7.11 Lambda Expressions ........................... Small anonymous functions can be created with the *note lambda: c2f. keyword. This function returns the sum of its two arguments: ‘lambda a, b: a+b’. Lambda functions can be used wherever function objects are required. They are syntactically restricted to a single expression. Semantically, they are just syntactic sugar for a normal function definition. Like nested function definitions, lambda functions can reference variables from the containing scope: >>> def make_incrementor(n): ... return lambda x: x + n ... >>> f = make_incrementor(42) >>> f(0) 42 >>> f(1) 43 The above example uses a lambda expression to return a function. Another use is to pass a small function as an argument: >>> pairs = [(1, 'one'), (2, 'two'), (3, 'three'), (4, 'four')] >>> pairs.sort(key=lambda pair: pair[1]) >>> pairs [(4, 'four'), (1, 'one'), (3, 'three'), (2, 'two')]  File: python.info, Node: Documentation Strings, Next: Function Annotations, Prev: Lambda Expressions, Up: More on Defining Functions 2.4.7.12 Documentation Strings .............................. Here are some conventions about the content and formatting of documentation strings. The first line should always be a short, concise summary of the object’s purpose. For brevity, it should not explicitly state the object’s name or type, since these are available by other means (except if the name happens to be a verb describing a function’s operation). This line should begin with a capital letter and end with a period. If there are more lines in the documentation string, the second line should be blank, visually separating the summary from the rest of the description. The following lines should be one or more paragraphs describing the object’s calling conventions, its side effects, etc. The Python parser does not strip indentation from multi-line string literals in Python, so tools that process documentation have to strip indentation if desired. This is done using the following convention. The first non-blank line `after' the first line of the string determines the amount of indentation for the entire documentation string. (We can’t use the first line since it is generally adjacent to the string’s opening quotes so its indentation is not apparent in the string literal.) Whitespace “equivalent” to this indentation is then stripped from the start of all lines of the string. Lines that are indented less should not occur, but if they occur all their leading whitespace should be stripped. Equivalence of whitespace should be tested after expansion of tabs (to 8 spaces, normally). Here is an example of a multi-line docstring: >>> def my_function(): ... """Do nothing, but document it. ... ... No, really, it doesn't do anything. ... """ ... pass ... >>> print(my_function.__doc__) Do nothing, but document it. No, really, it doesn't do anything.  File: python.info, Node: Function Annotations, Prev: Documentation Strings, Up: More on Defining Functions 2.4.7.13 Function Annotations ............................. *note Function annotations: ef0. are completely optional metadata information about the types used by user-defined functions (see PEP 3107(1) and PEP 484(2) for more information). *note Annotations: ef1. are stored in the ‘__annotations__’ attribute of the function as a dictionary and have no effect on any other part of the function. Parameter annotations are defined by a colon after the parameter name, followed by an expression evaluating to the value of the annotation. Return annotations are defined by a literal ‘->’, followed by an expression, between the parameter list and the colon denoting the end of the *note def: dbe. statement. The following example has a required argument, an optional argument, and the return value annotated: >>> def f(ham: str, eggs: str = 'eggs') -> str: ... print("Annotations:", f.__annotations__) ... print("Arguments:", ham, eggs) ... return ham + ' and ' + eggs ... >>> f('spam') Annotations: {'ham': , 'return': , 'eggs': } Arguments: spam eggs 'spam and eggs' ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3107 (2) https://www.python.org/dev/peps/pep-0484  File: python.info, Node: Intermezzo Coding Style, Prev: More on Defining Functions, Up: More Control Flow Tools 2.4.8 Intermezzo: Coding Style ------------------------------ Now that you are about to write longer, more complex pieces of Python, it is a good time to talk about `coding style'. Most languages can be written (or more concise, `formatted') in different styles; some are more readable than others. Making it easy for others to read your code is always a good idea, and adopting a nice coding style helps tremendously for that. For Python, PEP 8(1) has emerged as the style guide that most projects adhere to; it promotes a very readable and eye-pleasing coding style. Every Python developer should read it at some point; here are the most important points extracted for you: * Use 4-space indentation, and no tabs. 4 spaces are a good compromise between small indentation (allows greater nesting depth) and large indentation (easier to read). Tabs introduce confusion, and are best left out. * Wrap lines so that they don’t exceed 79 characters. This helps users with small displays and makes it possible to have several code files side-by-side on larger displays. * Use blank lines to separate functions and classes, and larger blocks of code inside functions. * When possible, put comments on a line of their own. * Use docstrings. * Use spaces around operators and after commas, but not directly inside bracketing constructs: ‘a = f(1, 2) + g(3, 4)’. * Name your classes and functions consistently; the convention is to use ‘UpperCamelCase’ for classes and ‘lowercase_with_underscores’ for functions and methods. Always use ‘self’ as the name for the first method argument (see *note A First Look at Classes: ef4. for more on classes and methods). * Don’t use fancy encodings if your code is meant to be used in international environments. Python’s default, UTF-8, or even plain ASCII work best in any case. * Likewise, don’t use non-ASCII characters in identifiers if there is only the slightest chance people speaking a different language will read or maintain the code. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0008  File: python.info, Node: Data Structures, Next: Modules, Prev: More Control Flow Tools, Up: The Python Tutorial 2.5 Data Structures =================== This chapter describes some things you’ve learned about already in more detail, and adds some new things as well. * Menu: * More on Lists:: * The del statement:: * Tuples and Sequences:: * Sets:: * Dictionaries:: * Looping Techniques:: * More on Conditions:: * Comparing Sequences and Other Types::  File: python.info, Node: More on Lists, Next: The del statement, Up: Data Structures 2.5.1 More on Lists ------------------- The list data type has some more methods. Here are all of the methods of list objects: -- Method: list.append (x) Add an item to the end of the list. Equivalent to ‘a[len(a):] = [x]’. -- Method: list.extend (iterable) Extend the list by appending all the items from the iterable. Equivalent to ‘a[len(a):] = iterable’. -- Method: list.insert (i, x) Insert an item at a given position. The first argument is the index of the element before which to insert, so ‘a.insert(0, x)’ inserts at the front of the list, and ‘a.insert(len(a), x)’ is equivalent to ‘a.append(x)’. -- Method: list.remove (x) Remove the first item from the list whose value is equal to `x'. It raises a *note ValueError: 1fb. if there is no such item. -- Method: list.pop ([i]) Remove the item at the given position in the list, and return it. If no index is specified, ‘a.pop()’ removes and returns the last item in the list. (The square brackets around the `i' in the method signature denote that the parameter is optional, not that you should type square brackets at that position. You will see this notation frequently in the Python Library Reference.) -- Method: list.clear () Remove all items from the list. Equivalent to ‘del a[:]’. -- Method: list.index (x[, start[, end]]) Return zero-based index in the list of the first item whose value is equal to `x'. Raises a *note ValueError: 1fb. if there is no such item. The optional arguments `start' and `end' are interpreted as in the slice notation and are used to limit the search to a particular subsequence of the list. The returned index is computed relative to the beginning of the full sequence rather than the `start' argument. -- Method: list.count (x) Return the number of times `x' appears in the list. -- Method: list.sort (*, key=None, reverse=False) Sort the items of the list in place (the arguments can be used for sort customization, see *note sorted(): 444. for their explanation). -- Method: list.reverse () Reverse the elements of the list in place. -- Method: list.copy () Return a shallow copy of the list. Equivalent to ‘a[:]’. An example that uses most of the list methods: >>> fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana'] >>> fruits.count('apple') 2 >>> fruits.count('tangerine') 0 >>> fruits.index('banana') 3 >>> fruits.index('banana', 4) # Find next banana starting a position 4 6 >>> fruits.reverse() >>> fruits ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange'] >>> fruits.append('grape') >>> fruits ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange', 'grape'] >>> fruits.sort() >>> fruits ['apple', 'apple', 'banana', 'banana', 'grape', 'kiwi', 'orange', 'pear'] >>> fruits.pop() 'pear' You might have noticed that methods like ‘insert’, ‘remove’ or ‘sort’ that only modify the list have no return value printed – they return the default ‘None’. (1) This is a design principle for all mutable data structures in Python. Another thing you might notice is that not all data can be sorted or compared. For instance, ‘[None, 'hello', 10]’ doesn’t sort because integers can’t be compared to strings and `None' can’t be compared to other types. Also, there are some types that don’t have a defined ordering relation. For example, ‘3+4j < 5+7j’ isn’t a valid comparison. * Menu: * Using Lists as Stacks:: * Using Lists as Queues:: * List Comprehensions: List Comprehensions<2>. * Nested List Comprehensions:: ---------- Footnotes ---------- (1) (1) Other languages may return the mutated object, which allows method chaining, such as ‘d->insert("a")->remove("b")->sort();’.  File: python.info, Node: Using Lists as Stacks, Next: Using Lists as Queues, Up: More on Lists 2.5.1.1 Using Lists as Stacks ............................. The list methods make it very easy to use a list as a stack, where the last element added is the first element retrieved (“last-in, first-out”). To add an item to the top of the stack, use ‘append()’. To retrieve an item from the top of the stack, use ‘pop()’ without an explicit index. For example: >>> stack = [3, 4, 5] >>> stack.append(6) >>> stack.append(7) >>> stack [3, 4, 5, 6, 7] >>> stack.pop() 7 >>> stack [3, 4, 5, 6] >>> stack.pop() 6 >>> stack.pop() 5 >>> stack [3, 4]  File: python.info, Node: Using Lists as Queues, Next: List Comprehensions<2>, Prev: Using Lists as Stacks, Up: More on Lists 2.5.1.2 Using Lists as Queues ............................. It is also possible to use a list as a queue, where the first element added is the first element retrieved (“first-in, first-out”); however, lists are not efficient for this purpose. While appends and pops from the end of list are fast, doing inserts or pops from the beginning of a list is slow (because all of the other elements have to be shifted by one). To implement a queue, use *note collections.deque: 531. which was designed to have fast appends and pops from both ends. For example: >>> from collections import deque >>> queue = deque(["Eric", "John", "Michael"]) >>> queue.append("Terry") # Terry arrives >>> queue.append("Graham") # Graham arrives >>> queue.popleft() # The first to arrive now leaves 'Eric' >>> queue.popleft() # The second to arrive now leaves 'John' >>> queue # Remaining queue in order of arrival deque(['Michael', 'Terry', 'Graham'])  File: python.info, Node: List Comprehensions<2>, Next: Nested List Comprehensions, Prev: Using Lists as Queues, Up: More on Lists 2.5.1.3 List Comprehensions ........................... List comprehensions provide a concise way to create lists. Common applications are to make new lists where each element is the result of some operations applied to each member of another sequence or iterable, or to create a subsequence of those elements that satisfy a certain condition. For example, assume we want to create a list of squares, like: >>> squares = [] >>> for x in range(10): ... squares.append(x**2) ... >>> squares [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] Note that this creates (or overwrites) a variable named ‘x’ that still exists after the loop completes. We can calculate the list of squares without any side effects using: squares = list(map(lambda x: x**2, range(10))) or, equivalently: squares = [x**2 for x in range(10)] which is more concise and readable. A list comprehension consists of brackets containing an expression followed by a ‘for’ clause, then zero or more ‘for’ or ‘if’ clauses. The result will be a new list resulting from evaluating the expression in the context of the ‘for’ and ‘if’ clauses which follow it. For example, this listcomp combines the elements of two lists if they are not equal: >>> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y] [(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)] and it’s equivalent to: >>> combs = [] >>> for x in [1,2,3]: ... for y in [3,1,4]: ... if x != y: ... combs.append((x, y)) ... >>> combs [(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)] Note how the order of the *note for: c30. and *note if: de7. statements is the same in both these snippets. If the expression is a tuple (e.g. the ‘(x, y)’ in the previous example), it must be parenthesized. >>> vec = [-4, -2, 0, 2, 4] >>> # create a new list with the values doubled >>> [x*2 for x in vec] [-8, -4, 0, 4, 8] >>> # filter the list to exclude negative numbers >>> [x for x in vec if x >= 0] [0, 2, 4] >>> # apply a function to all the elements >>> [abs(x) for x in vec] [4, 2, 0, 2, 4] >>> # call a method on each element >>> freshfruit = [' banana', ' loganberry ', 'passion fruit '] >>> [weapon.strip() for weapon in freshfruit] ['banana', 'loganberry', 'passion fruit'] >>> # create a list of 2-tuples like (number, square) >>> [(x, x**2) for x in range(6)] [(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)] >>> # the tuple must be parenthesized, otherwise an error is raised >>> [x, x**2 for x in range(6)] File "", line 1, in [x, x**2 for x in range(6)] ^ SyntaxError: invalid syntax >>> # flatten a list using a listcomp with two 'for' >>> vec = [[1,2,3], [4,5,6], [7,8,9]] >>> [num for elem in vec for num in elem] [1, 2, 3, 4, 5, 6, 7, 8, 9] List comprehensions can contain complex expressions and nested functions: >>> from math import pi >>> [str(round(pi, i)) for i in range(1, 6)] ['3.1', '3.14', '3.142', '3.1416', '3.14159']  File: python.info, Node: Nested List Comprehensions, Prev: List Comprehensions<2>, Up: More on Lists 2.5.1.4 Nested List Comprehensions .................................. The initial expression in a list comprehension can be any arbitrary expression, including another list comprehension. Consider the following example of a 3x4 matrix implemented as a list of 3 lists of length 4: >>> matrix = [ ... [1, 2, 3, 4], ... [5, 6, 7, 8], ... [9, 10, 11, 12], ... ] The following list comprehension will transpose rows and columns: >>> [[row[i] for row in matrix] for i in range(4)] [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]] As we saw in the previous section, the nested listcomp is evaluated in the context of the *note for: c30. that follows it, so this example is equivalent to: >>> transposed = [] >>> for i in range(4): ... transposed.append([row[i] for row in matrix]) ... >>> transposed [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]] which, in turn, is the same as: >>> transposed = [] >>> for i in range(4): ... # the following 3 lines implement the nested listcomp ... transposed_row = [] ... for row in matrix: ... transposed_row.append(row[i]) ... transposed.append(transposed_row) ... >>> transposed [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]] In the real world, you should prefer built-in functions to complex flow statements. The *note zip(): c32. function would do a great job for this use case: >>> list(zip(*matrix)) [(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)] See *note Unpacking Argument Lists: ee9. for details on the asterisk in this line.  File: python.info, Node: The del statement, Next: Tuples and Sequences, Prev: More on Lists, Up: Data Structures 2.5.2 The ‘del’ statement ------------------------- There is a way to remove an item from a list given its index instead of its value: the *note del: f02. statement. This differs from the ‘pop()’ method which returns a value. The ‘del’ statement can also be used to remove slices from a list or clear the entire list (which we did earlier by assignment of an empty list to the slice). For example: >>> a = [-1, 1, 66.25, 333, 333, 1234.5] >>> del a[0] >>> a [1, 66.25, 333, 333, 1234.5] >>> del a[2:4] >>> a [1, 66.25, 1234.5] >>> del a[:] >>> a [] *note del: f02. can also be used to delete entire variables: >>> del a Referencing the name ‘a’ hereafter is an error (at least until another value is assigned to it). We’ll find other uses for *note del: f02. later.  File: python.info, Node: Tuples and Sequences, Next: Sets, Prev: The del statement, Up: Data Structures 2.5.3 Tuples and Sequences -------------------------- We saw that lists and strings have many common properties, such as indexing and slicing operations. They are two examples of `sequence' data types (see *note Sequence Types — list, tuple, range: f04.). Since Python is an evolving language, other sequence data types may be added. There is also another standard sequence data type: the `tuple'. A tuple consists of a number of values separated by commas, for instance: >>> t = 12345, 54321, 'hello!' >>> t[0] 12345 >>> t (12345, 54321, 'hello!') >>> # Tuples may be nested: ... u = t, (1, 2, 3, 4, 5) >>> u ((12345, 54321, 'hello!'), (1, 2, 3, 4, 5)) >>> # Tuples are immutable: ... t[0] = 88888 Traceback (most recent call last): File "", line 1, in TypeError: 'tuple' object does not support item assignment >>> # but they can contain mutable objects: ... v = ([1, 2, 3], [3, 2, 1]) >>> v ([1, 2, 3], [3, 2, 1]) As you see, on output tuples are always enclosed in parentheses, so that nested tuples are interpreted correctly; they may be input with or without surrounding parentheses, although often parentheses are necessary anyway (if the tuple is part of a larger expression). It is not possible to assign to the individual items of a tuple, however it is possible to create tuples which contain mutable objects, such as lists. Though tuples may seem similar to lists, they are often used in different situations and for different purposes. Tuples are *note immutable: eb6, and usually contain a heterogeneous sequence of elements that are accessed via unpacking (see later in this section) or indexing (or even by attribute in the case of *note namedtuples: 1b7.). Lists are *note mutable: ebe, and their elements are usually homogeneous and are accessed by iterating over the list. A special problem is the construction of tuples containing 0 or 1 items: the syntax has some extra quirks to accommodate these. Empty tuples are constructed by an empty pair of parentheses; a tuple with one item is constructed by following a value with a comma (it is not sufficient to enclose a single value in parentheses). Ugly, but effective. For example: >>> empty = () >>> singleton = 'hello', # <-- note trailing comma >>> len(empty) 0 >>> len(singleton) 1 >>> singleton ('hello',) The statement ‘t = 12345, 54321, 'hello!'’ is an example of `tuple packing': the values ‘12345’, ‘54321’ and ‘'hello!'’ are packed together in a tuple. The reverse operation is also possible: >>> x, y, z = t This is called, appropriately enough, `sequence unpacking' and works for any sequence on the right-hand side. Sequence unpacking requires that there are as many variables on the left side of the equals sign as there are elements in the sequence. Note that multiple assignment is really just a combination of tuple packing and sequence unpacking.  File: python.info, Node: Sets, Next: Dictionaries, Prev: Tuples and Sequences, Up: Data Structures 2.5.4 Sets ---------- Python also includes a data type for `sets'. A set is an unordered collection with no duplicate elements. Basic uses include membership testing and eliminating duplicate entries. Set objects also support mathematical operations like union, intersection, difference, and symmetric difference. Curly braces or the *note set(): b6f. function can be used to create sets. Note: to create an empty set you have to use ‘set()’, not ‘{}’; the latter creates an empty dictionary, a data structure that we discuss in the next section. Here is a brief demonstration: >>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'} >>> print(basket) # show that duplicates have been removed {'orange', 'banana', 'pear', 'apple'} >>> 'orange' in basket # fast membership testing True >>> 'crabgrass' in basket False >>> # Demonstrate set operations on unique letters from two words ... >>> a = set('abracadabra') >>> b = set('alacazam') >>> a # unique letters in a {'a', 'r', 'b', 'c', 'd'} >>> a - b # letters in a but not in b {'r', 'd', 'b'} >>> a | b # letters in a or b or both {'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'} >>> a & b # letters in both a and b {'a', 'c'} >>> a ^ b # letters in a or b but not both {'r', 'd', 'b', 'm', 'z', 'l'} Similarly to *note list comprehensions: efe, set comprehensions are also supported: >>> a = {x for x in 'abracadabra' if x not in 'abc'} >>> a {'r', 'd'}  File: python.info, Node: Dictionaries, Next: Looping Techniques, Prev: Sets, Up: Data Structures 2.5.5 Dictionaries ------------------ Another useful data type built into Python is the `dictionary' (see *note Mapping Types — dict: 2fc.). Dictionaries are sometimes found in other languages as “associative memories” or “associative arrays”. Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by `keys', which can be any immutable type; strings and numbers can always be keys. Tuples can be used as keys if they contain only strings, numbers, or tuples; if a tuple contains any mutable object either directly or indirectly, it cannot be used as a key. You can’t use lists as keys, since lists can be modified in place using index assignments, slice assignments, or methods like ‘append()’ and ‘extend()’. It is best to think of a dictionary as a set of `key: value' pairs, with the requirement that the keys are unique (within one dictionary). A pair of braces creates an empty dictionary: ‘{}’. Placing a comma-separated list of key:value pairs within the braces adds initial key:value pairs to the dictionary; this is also the way dictionaries are written on output. The main operations on a dictionary are storing a value with some key and extracting the value given the key. It is also possible to delete a key:value pair with ‘del’. If you store using a key that is already in use, the old value associated with that key is forgotten. It is an error to extract a value using a non-existent key. Performing ‘list(d)’ on a dictionary returns a list of all the keys used in the dictionary, in insertion order (if you want it sorted, just use ‘sorted(d)’ instead). To check whether a single key is in the dictionary, use the *note in: 7a3. keyword. Here is a small example using a dictionary: >>> tel = {'jack': 4098, 'sape': 4139} >>> tel['guido'] = 4127 >>> tel {'jack': 4098, 'sape': 4139, 'guido': 4127} >>> tel['jack'] 4098 >>> del tel['sape'] >>> tel['irv'] = 4127 >>> tel {'jack': 4098, 'guido': 4127, 'irv': 4127} >>> list(tel) ['jack', 'guido', 'irv'] >>> sorted(tel) ['guido', 'irv', 'jack'] >>> 'guido' in tel True >>> 'jack' not in tel False The *note dict(): 1b8. constructor builds dictionaries directly from sequences of key-value pairs: >>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)]) {'sape': 4139, 'guido': 4127, 'jack': 4098} In addition, dict comprehensions can be used to create dictionaries from arbitrary key and value expressions: >>> {x: x**2 for x in (2, 4, 6)} {2: 4, 4: 16, 6: 36} When the keys are simple strings, it is sometimes easier to specify pairs using keyword arguments: >>> dict(sape=4139, guido=4127, jack=4098) {'sape': 4139, 'guido': 4127, 'jack': 4098}  File: python.info, Node: Looping Techniques, Next: More on Conditions, Prev: Dictionaries, Up: Data Structures 2.5.6 Looping Techniques ------------------------ When looping through dictionaries, the key and corresponding value can be retrieved at the same time using the ‘items()’ method. >>> knights = {'gallahad': 'the pure', 'robin': 'the brave'} >>> for k, v in knights.items(): ... print(k, v) ... gallahad the pure robin the brave When looping through a sequence, the position index and corresponding value can be retrieved at the same time using the *note enumerate(): de3. function. >>> for i, v in enumerate(['tic', 'tac', 'toe']): ... print(i, v) ... 0 tic 1 tac 2 toe To loop over two or more sequences at the same time, the entries can be paired with the *note zip(): c32. function. >>> questions = ['name', 'quest', 'favorite color'] >>> answers = ['lancelot', 'the holy grail', 'blue'] >>> for q, a in zip(questions, answers): ... print('What is your {0}? It is {1}.'.format(q, a)) ... What is your name? It is lancelot. What is your quest? It is the holy grail. What is your favorite color? It is blue. To loop over a sequence in reverse, first specify the sequence in a forward direction and then call the *note reversed(): 18e. function. >>> for i in reversed(range(1, 10, 2)): ... print(i) ... 9 7 5 3 1 To loop over a sequence in sorted order, use the *note sorted(): 444. function which returns a new sorted list while leaving the source unaltered. >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana'] >>> for f in sorted(set(basket)): ... print(f) ... apple banana orange pear It is sometimes tempting to change a list while you are looping over it; however, it is often simpler and safer to create a new list instead. >>> import math >>> raw_data = [56.2, float('NaN'), 51.7, 55.3, 52.5, float('NaN'), 47.8] >>> filtered_data = [] >>> for value in raw_data: ... if not math.isnan(value): ... filtered_data.append(value) ... >>> filtered_data [56.2, 51.7, 55.3, 52.5, 47.8]  File: python.info, Node: More on Conditions, Next: Comparing Sequences and Other Types, Prev: Looping Techniques, Up: Data Structures 2.5.7 More on Conditions ------------------------ The conditions used in ‘while’ and ‘if’ statements can contain any operators, not just comparisons. The comparison operators ‘in’ and ‘not in’ check whether a value occurs (does not occur) in a sequence. The operators ‘is’ and ‘is not’ compare whether two objects are really the same object; this only matters for mutable objects like lists. All comparison operators have the same priority, which is lower than that of all numerical operators. Comparisons can be chained. For example, ‘a < b == c’ tests whether ‘a’ is less than ‘b’ and moreover ‘b’ equals ‘c’. Comparisons may be combined using the Boolean operators ‘and’ and ‘or’, and the outcome of a comparison (or of any other Boolean expression) may be negated with ‘not’. These have lower priorities than comparison operators; between them, ‘not’ has the highest priority and ‘or’ the lowest, so that ‘A and not B or C’ is equivalent to ‘(A and (not B)) or C’. As always, parentheses can be used to express the desired composition. The Boolean operators ‘and’ and ‘or’ are so-called `short-circuit' operators: their arguments are evaluated from left to right, and evaluation stops as soon as the outcome is determined. For example, if ‘A’ and ‘C’ are true but ‘B’ is false, ‘A and B and C’ does not evaluate the expression ‘C’. When used as a general value and not as a Boolean, the return value of a short-circuit operator is the last evaluated argument. It is possible to assign the result of a comparison or other Boolean expression to a variable. For example, >>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance' >>> non_null = string1 or string2 or string3 >>> non_null 'Trondheim' Note that in Python, unlike C, assignment inside expressions must be done explicitly with the *note walrus operator: f0c. ‘:=’. This avoids a common class of problems encountered in C programs: typing ‘=’ in an expression when ‘==’ was intended.  File: python.info, Node: Comparing Sequences and Other Types, Prev: More on Conditions, Up: Data Structures 2.5.8 Comparing Sequences and Other Types ----------------------------------------- Sequence objects typically may be compared to other objects with the same sequence type. The comparison uses `lexicographical' ordering: first the first two items are compared, and if they differ this determines the outcome of the comparison; if they are equal, the next two items are compared, and so on, until either sequence is exhausted. If two items to be compared are themselves sequences of the same type, the lexicographical comparison is carried out recursively. If all items of two sequences compare equal, the sequences are considered equal. If one sequence is an initial sub-sequence of the other, the shorter sequence is the smaller (lesser) one. Lexicographical ordering for strings uses the Unicode code point number to order individual characters. Some examples of comparisons between sequences of the same type: (1, 2, 3) < (1, 2, 4) [1, 2, 3] < [1, 2, 4] 'ABC' < 'C' < 'Pascal' < 'Python' (1, 2, 3, 4) < (1, 2, 4) (1, 2) < (1, 2, -1) (1, 2, 3) == (1.0, 2.0, 3.0) (1, 2, ('aa', 'ab')) < (1, 2, ('abc', 'a'), 4) Note that comparing objects of different types with ‘<’ or ‘>’ is legal provided that the objects have appropriate comparison methods. For example, mixed numeric types are compared according to their numeric value, so 0 equals 0.0, etc. Otherwise, rather than providing an arbitrary ordering, the interpreter will raise a *note TypeError: 192. exception.  File: python.info, Node: Modules, Next: Input and Output, Prev: Data Structures, Up: The Python Tutorial 2.6 Modules =========== If you quit from the Python interpreter and enter it again, the definitions you have made (functions and variables) are lost. Therefore, if you want to write a somewhat longer program, you are better off using a text editor to prepare the input for the interpreter and running it with that file as input instead. This is known as creating a `script'. As your program gets longer, you may want to split it into several files for easier maintenance. You may also want to use a handy function that you’ve written in several programs without copying its definition into each program. To support this, Python has a way to put definitions in a file and use them in a script or in an interactive instance of the interpreter. Such a file is called a `module'; definitions from a module can be `imported' into other modules or into the `main' module (the collection of variables that you have access to in a script executed at the top level and in calculator mode). A module is a file containing Python definitions and statements. The file name is the module name with the suffix ‘.py’ appended. Within a module, the module’s name (as a string) is available as the value of the global variable ‘__name__’. For instance, use your favorite text editor to create a file called ‘fibo.py’ in the current directory with the following contents: # Fibonacci numbers module def fib(n): # write Fibonacci series up to n a, b = 0, 1 while a < n: print(a, end=' ') a, b = b, a+b print() def fib2(n): # return Fibonacci series up to n result = [] a, b = 0, 1 while a < n: result.append(a) a, b = b, a+b return result Now enter the Python interpreter and import this module with the following command: >>> import fibo This does not enter the names of the functions defined in ‘fibo’ directly in the current symbol table; it only enters the module name ‘fibo’ there. Using the module name you can access the functions: >>> fibo.fib(1000) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 >>> fibo.fib2(100) [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] >>> fibo.__name__ 'fibo' If you intend to use a function often you can assign it to a local name: >>> fib = fibo.fib >>> fib(500) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 * Menu: * More on Modules:: * Standard Modules:: * The dir() Function: The dir Function. * Packages::  File: python.info, Node: More on Modules, Next: Standard Modules, Up: Modules 2.6.1 More on Modules --------------------- A module can contain executable statements as well as function definitions. These statements are intended to initialize the module. They are executed only the `first' time the module name is encountered in an import statement. (1) (They are also run if the file is executed as a script.) Each module has its own private symbol table, which is used as the global symbol table by all functions defined in the module. Thus, the author of a module can use global variables in the module without worrying about accidental clashes with a user’s global variables. On the other hand, if you know what you are doing you can touch a module’s global variables with the same notation used to refer to its functions, ‘modname.itemname’. Modules can import other modules. It is customary but not required to place all *note import: c1d. statements at the beginning of a module (or script, for that matter). The imported module names are placed in the importing module’s global symbol table. There is a variant of the *note import: c1d. statement that imports names from a module directly into the importing module’s symbol table. For example: >>> from fibo import fib, fib2 >>> fib(500) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 This does not introduce the module name from which the imports are taken in the local symbol table (so in the example, ‘fibo’ is not defined). There is even a variant to import all names that a module defines: >>> from fibo import * >>> fib(500) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 This imports all names except those beginning with an underscore (‘_’). In most cases Python programmers do not use this facility since it introduces an unknown set of names into the interpreter, possibly hiding some things you have already defined. Note that in general the practice of importing ‘*’ from a module or package is frowned upon, since it often causes poorly readable code. However, it is okay to use it to save typing in interactive sessions. If the module name is followed by ‘as’, then the name following ‘as’ is bound directly to the imported module. >>> import fibo as fib >>> fib.fib(500) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 This is effectively importing the module in the same way that ‘import fibo’ will do, with the only difference of it being available as ‘fib’. It can also be used when utilising *note from: c45. with similar effects: >>> from fibo import fib as fibonacci >>> fibonacci(500) 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 Note: For efficiency reasons, each module is only imported once per interpreter session. Therefore, if you change your modules, you must restart the interpreter – or, if it’s just one module you want to test interactively, use *note importlib.reload(): 399, e.g. ‘import importlib; importlib.reload(modulename)’. * Menu: * Executing modules as scripts:: * The Module Search Path:: * “Compiled” Python files:: ---------- Footnotes ---------- (1) (1) In fact function definitions are also ‘statements’ that are ‘executed’; the execution of a module-level function definition enters the function name in the module’s global symbol table.  File: python.info, Node: Executing modules as scripts, Next: The Module Search Path, Up: More on Modules 2.6.1.1 Executing modules as scripts .................................... When you run a Python module with python fibo.py the code in the module will be executed, just as if you imported it, but with the ‘__name__’ set to ‘"__main__"’. That means that by adding this code at the end of your module: if __name__ == "__main__": import sys fib(int(sys.argv[1])) you can make the file usable as a script as well as an importable module, because the code that parses the command line only runs if the module is executed as the “main” file: $ python fibo.py 50 0 1 1 2 3 5 8 13 21 34 If the module is imported, the code is not run: >>> import fibo >>> This is often used either to provide a convenient user interface to a module, or for testing purposes (running the module as a script executes a test suite).  File: python.info, Node: The Module Search Path, Next: “Compiled” Python files, Prev: Executing modules as scripts, Up: More on Modules 2.6.1.2 The Module Search Path .............................. When a module named ‘spam’ is imported, the interpreter first searches for a built-in module with that name. If not found, it then searches for a file named ‘spam.py’ in a list of directories given by the variable *note sys.path: 488. *note sys.path: 488. is initialized from these locations: * The directory containing the input script (or the current directory when no file is specified). * *note PYTHONPATH: 953. (a list of directory names, with the same syntax as the shell variable ‘PATH’). * The installation-dependent default. Note: On file systems which support symlinks, the directory containing the input script is calculated after the symlink is followed. In other words the directory containing the symlink is `not' added to the module search path. After initialization, Python programs can modify *note sys.path: 488. The directory containing the script being run is placed at the beginning of the search path, ahead of the standard library path. This means that scripts in that directory will be loaded instead of modules of the same name in the library directory. This is an error unless the replacement is intended. See section *note Standard Modules: f18. for more information.  File: python.info, Node: “Compiled” Python files, Prev: The Module Search Path, Up: More on Modules 2.6.1.3 “Compiled” Python files ............................... To speed up loading modules, Python caches the compiled version of each module in the ‘__pycache__’ directory under the name ‘module.`version'.pyc’, where the version encodes the format of the compiled file; it generally contains the Python version number. For example, in CPython release 3.3 the compiled version of spam.py would be cached as ‘__pycache__/spam.cpython-33.pyc’. This naming convention allows compiled modules from different releases and different versions of Python to coexist. Python checks the modification date of the source against the compiled version to see if it’s out of date and needs to be recompiled. This is a completely automatic process. Also, the compiled modules are platform-independent, so the same library can be shared among systems with different architectures. Python does not check the cache in two circumstances. First, it always recompiles and does not store the result for the module that’s loaded directly from the command line. Second, it does not check the cache if there is no source module. To support a non-source (compiled only) distribution, the compiled module must be in the source directory, and there must not be a source module. Some tips for experts: * You can use the *note -O: 68b. or *note -OO: 68c. switches on the Python command to reduce the size of a compiled module. The ‘-O’ switch removes assert statements, the ‘-OO’ switch removes both assert statements and __doc__ strings. Since some programs may rely on having these available, you should only use this option if you know what you’re doing. “Optimized” modules have an ‘opt-’ tag and are usually smaller. Future releases may change the effects of optimization. * A program doesn’t run any faster when it is read from a ‘.pyc’ file than when it is read from a ‘.py’ file; the only thing that’s faster about ‘.pyc’ files is the speed with which they are loaded. * The module *note compileall: 21. can create .pyc files for all modules in a directory. * There is more detail on this process, including a flow chart of the decisions, in PEP 3147(1). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: Standard Modules, Next: The dir Function, Prev: More on Modules, Up: Modules 2.6.2 Standard Modules ---------------------- Python comes with a library of standard modules, described in a separate document, the Python Library Reference (“Library Reference” hereafter). Some modules are built into the interpreter; these provide access to operations that are not part of the core of the language but are nevertheless built in, either for efficiency or to provide access to operating system primitives such as system calls. The set of such modules is a configuration option which also depends on the underlying platform. For example, the *note winreg: 12a. module is only provided on Windows systems. One particular module deserves some attention: *note sys: fd, which is built into every Python interpreter. The variables ‘sys.ps1’ and ‘sys.ps2’ define the strings used as primary and secondary prompts: >>> import sys >>> sys.ps1 '>>> ' >>> sys.ps2 '... ' >>> sys.ps1 = 'C> ' C> print('Yuck!') Yuck! C> These two variables are only defined if the interpreter is in interactive mode. The variable ‘sys.path’ is a list of strings that determines the interpreter’s search path for modules. It is initialized to a default path taken from the environment variable *note PYTHONPATH: 953, or from a built-in default if *note PYTHONPATH: 953. is not set. You can modify it using standard list operations: >>> import sys >>> sys.path.append('/ufs/guido/lib/python')  File: python.info, Node: The dir Function, Next: Packages, Prev: Standard Modules, Up: Modules 2.6.3 The ‘dir()’ Function -------------------------- The built-in function *note dir(): d33. is used to find out which names a module defines. It returns a sorted list of strings: >>> import fibo, sys >>> dir(fibo) ['__name__', 'fib', 'fib2'] >>> dir(sys) ['__displayhook__', '__doc__', '__excepthook__', '__loader__', '__name__', '__package__', '__stderr__', '__stdin__', '__stdout__', '_clear_type_cache', '_current_frames', '_debugmallocstats', '_getframe', '_home', '_mercurial', '_xoptions', 'abiflags', 'api_version', 'argv', 'base_exec_prefix', 'base_prefix', 'builtin_module_names', 'byteorder', 'call_tracing', 'callstats', 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_info', 'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info', 'float_repr_style', 'getcheckinterval', 'getdefaultencoding', 'getdlopenflags', 'getfilesystemencoding', 'getobjects', 'getprofile', 'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval', 'gettotalrefcount', 'gettrace', 'hash_info', 'hexversion', 'implementation', 'int_info', 'intern', 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1', 'setcheckinterval', 'setdlopenflags', 'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace', 'stderr', 'stdin', 'stdout', 'thread_info', 'version', 'version_info', 'warnoptions'] Without arguments, *note dir(): d33. lists the names you have defined currently: >>> a = [1, 2, 3, 4, 5] >>> import fibo >>> fib = fibo.fib >>> dir() ['__builtins__', '__name__', 'a', 'fib', 'fibo', 'sys'] Note that it lists all types of names: variables, modules, functions, etc. *note dir(): d33. does not list the names of built-in functions and variables. If you want a list of those, they are defined in the standard module *note builtins: 13.: >>> import builtins >>> dir(builtins) ['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'ZeroDivisionError', '_', '__build_class__', '__debug__', '__doc__', '__import__', '__name__', '__package__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']  File: python.info, Node: Packages, Prev: The dir Function, Up: Modules 2.6.4 Packages -------------- Packages are a way of structuring Python’s module namespace by using “dotted module names”. For example, the module name ‘A.B’ designates a submodule named ‘B’ in a package named ‘A’. Just like the use of modules saves the authors of different modules from having to worry about each other’s global variable names, the use of dotted module names saves the authors of multi-module packages like NumPy or Pillow from having to worry about each other’s module names. Suppose you want to design a collection of modules (a “package”) for the uniform handling of sound files and sound data. There are many different sound file formats (usually recognized by their extension, for example: ‘.wav’, ‘.aiff’, ‘.au’), so you may need to create and maintain a growing collection of modules for the conversion between the various file formats. There are also many different operations you might want to perform on sound data (such as mixing, adding echo, applying an equalizer function, creating an artificial stereo effect), so in addition you will be writing a never-ending stream of modules to perform these operations. Here’s a possible structure for your package (expressed in terms of a hierarchical filesystem): sound/ Top-level package __init__.py Initialize the sound package formats/ Subpackage for file format conversions __init__.py wavread.py wavwrite.py aiffread.py aiffwrite.py auread.py auwrite.py ... effects/ Subpackage for sound effects __init__.py echo.py surround.py reverse.py ... filters/ Subpackage for filters __init__.py equalizer.py vocoder.py karaoke.py ... When importing the package, Python searches through the directories on ‘sys.path’ looking for the package subdirectory. The ‘__init__.py’ files are required to make Python treat directories containing the file as packages. This prevents directories with a common name, such as ‘string’, unintentionally hiding valid modules that occur later on the module search path. In the simplest case, ‘__init__.py’ can just be an empty file, but it can also execute initialization code for the package or set the ‘__all__’ variable, described later. Users of the package can import individual modules from the package, for example: import sound.effects.echo This loads the submodule ‘sound.effects.echo’. It must be referenced with its full name. sound.effects.echo.echofilter(input, output, delay=0.7, atten=4) An alternative way of importing the submodule is: from sound.effects import echo This also loads the submodule ‘echo’, and makes it available without its package prefix, so it can be used as follows: echo.echofilter(input, output, delay=0.7, atten=4) Yet another variation is to import the desired function or variable directly: from sound.effects.echo import echofilter Again, this loads the submodule ‘echo’, but this makes its function ‘echofilter()’ directly available: echofilter(input, output, delay=0.7, atten=4) Note that when using ‘from package import item’, the item can be either a submodule (or subpackage) of the package, or some other name defined in the package, like a function, class or variable. The ‘import’ statement first tests whether the item is defined in the package; if not, it assumes it is a module and attempts to load it. If it fails to find it, an *note ImportError: 334. exception is raised. Contrarily, when using syntax like ‘import item.subitem.subsubitem’, each item except for the last must be a package; the last item can be a module or a package but can’t be a class or function or variable defined in the previous item. * Menu: * Importing * From a Package:: * Intra-package References:: * Packages in Multiple Directories::  File: python.info, Node: Importing * From a Package, Next: Intra-package References, Up: Packages 2.6.4.1 Importing * From a Package .................................. Now what happens when the user writes ‘from sound.effects import *’? Ideally, one would hope that this somehow goes out to the filesystem, finds which submodules are present in the package, and imports them all. This could take a long time and importing sub-modules might have unwanted side-effects that should only happen when the sub-module is explicitly imported. The only solution is for the package author to provide an explicit index of the package. The *note import: c1d. statement uses the following convention: if a package’s ‘__init__.py’ code defines a list named ‘__all__’, it is taken to be the list of module names that should be imported when ‘from package import *’ is encountered. It is up to the package author to keep this list up-to-date when a new version of the package is released. Package authors may also decide not to support it, if they don’t see a use for importing * from their package. For example, the file ‘sound/effects/__init__.py’ could contain the following code: __all__ = ["echo", "surround", "reverse"] This would mean that ‘from sound.effects import *’ would import the three named submodules of the ‘sound’ package. If ‘__all__’ is not defined, the statement ‘from sound.effects import *’ does `not' import all submodules from the package ‘sound.effects’ into the current namespace; it only ensures that the package ‘sound.effects’ has been imported (possibly running any initialization code in ‘__init__.py’) and then imports whatever names are defined in the package. This includes any names defined (and submodules explicitly loaded) by ‘__init__.py’. It also includes any submodules of the package that were explicitly loaded by previous *note import: c1d. statements. Consider this code: import sound.effects.echo import sound.effects.surround from sound.effects import * In this example, the ‘echo’ and ‘surround’ modules are imported in the current namespace because they are defined in the ‘sound.effects’ package when the ‘from...import’ statement is executed. (This also works when ‘__all__’ is defined.) Although certain modules are designed to export only names that follow certain patterns when you use ‘import *’, it is still considered bad practice in production code. Remember, there is nothing wrong with using ‘from package import specific_submodule’! In fact, this is the recommended notation unless the importing module needs to use submodules with the same name from different packages.  File: python.info, Node: Intra-package References, Next: Packages in Multiple Directories, Prev: Importing * From a Package, Up: Packages 2.6.4.2 Intra-package References ................................ When packages are structured into subpackages (as with the ‘sound’ package in the example), you can use absolute imports to refer to submodules of siblings packages. For example, if the module ‘sound.filters.vocoder’ needs to use the ‘echo’ module in the ‘sound.effects’ package, it can use ‘from sound.effects import echo’. You can also write relative imports, with the ‘from module import name’ form of import statement. These imports use leading dots to indicate the current and parent packages involved in the relative import. From the ‘surround’ module for example, you might use: from . import echo from .. import formats from ..filters import equalizer Note that relative imports are based on the name of the current module. Since the name of the main module is always ‘"__main__"’, modules intended for use as the main module of a Python application must always use absolute imports.  File: python.info, Node: Packages in Multiple Directories, Prev: Intra-package References, Up: Packages 2.6.4.3 Packages in Multiple Directories ........................................ Packages support one more special attribute, *note __path__: f23. This is initialized to be a list containing the name of the directory holding the package’s ‘__init__.py’ before the code in that file is executed. This variable can be modified; doing so affects future searches for modules and subpackages contained in the package. While this feature is not often needed, it can be used to extend the set of modules found in a package.  File: python.info, Node: Input and Output, Next: Errors and Exceptions, Prev: Modules, Up: The Python Tutorial 2.7 Input and Output ==================== There are several ways to present the output of a program; data can be printed in a human-readable form, or written to a file for future use. This chapter will discuss some of the possibilities. * Menu: * Fancier Output Formatting:: * Reading and Writing Files::  File: python.info, Node: Fancier Output Formatting, Next: Reading and Writing Files, Up: Input and Output 2.7.1 Fancier Output Formatting ------------------------------- So far we’ve encountered two ways of writing values: `expression statements' and the *note print(): 886. function. (A third way is using the ‘write()’ method of file objects; the standard output file can be referenced as ‘sys.stdout’. See the Library Reference for more information on this.) Often you’ll want more control over the formatting of your output than simply printing space-separated values. There are several ways to format output. * To use *note formatted string literals: f29, begin a string with ‘f’ or ‘F’ before the opening quotation mark or triple quotation mark. Inside this string, you can write a Python expression between ‘{’ and ‘}’ characters that can refer to variables or literal values. >>> year = 2016 >>> event = 'Referendum' >>> f'Results of the {year} {event}' 'Results of the 2016 Referendum' * The *note str.format(): 4da. method of strings requires more manual effort. You’ll still use ‘{’ and ‘}’ to mark where a variable will be substituted and can provide detailed formatting directives, but you’ll also need to provide the information to be formatted. >>> yes_votes = 42_572_654 >>> no_votes = 43_132_495 >>> percentage = yes_votes / (yes_votes + no_votes) >>> '{:-9} YES votes {:2.2%}'.format(yes_votes, percentage) ' 42572654 YES votes 49.67%' * Finally, you can do all the string handling yourself by using string slicing and concatenation operations to create any layout you can imagine. The string type has some methods that perform useful operations for padding strings to a given column width. When you don’t need fancy output but just want a quick display of some variables for debugging purposes, you can convert any value to a string with the *note repr(): 7cc. or *note str(): 330. functions. The *note str(): 330. function is meant to return representations of values which are fairly human-readable, while *note repr(): 7cc. is meant to generate representations which can be read by the interpreter (or will force a *note SyntaxError: 458. if there is no equivalent syntax). For objects which don’t have a particular representation for human consumption, *note str(): 330. will return the same value as *note repr(): 7cc. Many values, such as numbers or structures like lists and dictionaries, have the same representation using either function. Strings, in particular, have two distinct representations. Some examples: >>> s = 'Hello, world.' >>> str(s) 'Hello, world.' >>> repr(s) "'Hello, world.'" >>> str(1/7) '0.14285714285714285' >>> x = 10 * 3.25 >>> y = 200 * 200 >>> s = 'The value of x is ' + repr(x) + ', and y is ' + repr(y) + '...' >>> print(s) The value of x is 32.5, and y is 40000... >>> # The repr() of a string adds string quotes and backslashes: ... hello = 'hello, world\n' >>> hellos = repr(hello) >>> print(hellos) 'hello, world\n' >>> # The argument to repr() may be any Python object: ... repr((x, y, ('spam', 'eggs'))) "(32.5, 40000, ('spam', 'eggs'))" The *note string: f6. module contains a *note Template: 3eb. class that offers yet another way to substitute values into strings, using placeholders like ‘$x’ and replacing them with values from a dictionary, but offers much less control of the formatting. * Menu: * Formatted String Literals:: * The String format() Method: The String format Method. * Manual String Formatting:: * Old string formatting::  File: python.info, Node: Formatted String Literals, Next: The String format Method, Up: Fancier Output Formatting 2.7.1.1 Formatted String Literals ................................. *note Formatted string literals: 15c. (also called f-strings for short) let you include the value of Python expressions inside a string by prefixing the string with ‘f’ or ‘F’ and writing expressions as ‘{expression}’. An optional format specifier can follow the expression. This allows greater control over how the value is formatted. The following example rounds pi to three places after the decimal: >>> import math >>> print(f'The value of pi is approximately {math.pi:.3f}.') The value of pi is approximately 3.142. Passing an integer after the ‘':'’ will cause that field to be a minimum number of characters wide. This is useful for making columns line up. >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 7678} >>> for name, phone in table.items(): ... print(f'{name:10} ==> {phone:10d}') ... Sjoerd ==> 4127 Jack ==> 4098 Dcab ==> 7678 Other modifiers can be used to convert the value before it is formatted. ‘'!a'’ applies *note ascii(): d4c, ‘'!s'’ applies *note str(): 330, and ‘'!r'’ applies *note repr(): 7cc.: >>> animals = 'eels' >>> print(f'My hovercraft is full of {animals}.') My hovercraft is full of eels. >>> print(f'My hovercraft is full of {animals!r}.') My hovercraft is full of 'eels'. For a reference on these format specifications, see the reference guide for the *note Format Specification Mini-Language: 4de.  File: python.info, Node: The String format Method, Next: Manual String Formatting, Prev: Formatted String Literals, Up: Fancier Output Formatting 2.7.1.2 The String format() Method .................................. Basic usage of the *note str.format(): 4da. method looks like this: >>> print('We are the {} who say "{}!"'.format('knights', 'Ni')) We are the knights who say "Ni!" The brackets and characters within them (called format fields) are replaced with the objects passed into the *note str.format(): 4da. method. A number in the brackets can be used to refer to the position of the object passed into the *note str.format(): 4da. method. >>> print('{0} and {1}'.format('spam', 'eggs')) spam and eggs >>> print('{1} and {0}'.format('spam', 'eggs')) eggs and spam If keyword arguments are used in the *note str.format(): 4da. method, their values are referred to by using the name of the argument. >>> print('This {food} is {adjective}.'.format( ... food='spam', adjective='absolutely horrible')) This spam is absolutely horrible. Positional and keyword arguments can be arbitrarily combined: >>> print('The story of {0}, {1}, and {other}.'.format('Bill', 'Manfred', other='Georg')) The story of Bill, Manfred, and Georg. If you have a really long format string that you don’t want to split up, it would be nice if you could reference the variables to be formatted by name instead of by position. This can be done by simply passing the dict and using square brackets ‘'[]'’ to access the keys. >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678} >>> print('Jack: {0[Jack]:d}; Sjoerd: {0[Sjoerd]:d}; ' ... 'Dcab: {0[Dcab]:d}'.format(table)) Jack: 4098; Sjoerd: 4127; Dcab: 8637678 This could also be done by passing the table as keyword arguments with the ‘**’ notation. >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678} >>> print('Jack: {Jack:d}; Sjoerd: {Sjoerd:d}; Dcab: {Dcab:d}'.format(**table)) Jack: 4098; Sjoerd: 4127; Dcab: 8637678 This is particularly useful in combination with the built-in function *note vars(): f2d, which returns a dictionary containing all local variables. As an example, the following lines produce a tidily-aligned set of columns giving integers and their squares and cubes: >>> for x in range(1, 11): ... print('{0:2d} {1:3d} {2:4d}'.format(x, x*x, x*x*x)) ... 1 1 1 2 4 8 3 9 27 4 16 64 5 25 125 6 36 216 7 49 343 8 64 512 9 81 729 10 100 1000 For a complete overview of string formatting with *note str.format(): 4da, see *note Format String Syntax: d1a.  File: python.info, Node: Manual String Formatting, Next: Old string formatting, Prev: The String format Method, Up: Fancier Output Formatting 2.7.1.3 Manual String Formatting ................................ Here’s the same table of squares and cubes, formatted manually: >>> for x in range(1, 11): ... print(repr(x).rjust(2), repr(x*x).rjust(3), end=' ') ... # Note use of 'end' on previous line ... print(repr(x*x*x).rjust(4)) ... 1 1 1 2 4 8 3 9 27 4 16 64 5 25 125 6 36 216 7 49 343 8 64 512 9 81 729 10 100 1000 (Note that the one space between each column was added by the way *note print(): 886. works: it always adds spaces between its arguments.) The *note str.rjust(): f2f. method of string objects right-justifies a string in a field of a given width by padding it with spaces on the left. There are similar methods *note str.ljust(): f30. and *note str.center(): f31. These methods do not write anything, they just return a new string. If the input string is too long, they don’t truncate it, but return it unchanged; this will mess up your column lay-out but that’s usually better than the alternative, which would be lying about a value. (If you really want truncation you can always add a slice operation, as in ‘x.ljust(n)[:n]’.) There is another method, *note str.zfill(): f32, which pads a numeric string on the left with zeros. It understands about plus and minus signs: >>> '12'.zfill(5) '00012' >>> '-3.14'.zfill(7) '-003.14' >>> '3.14159265359'.zfill(5) '3.14159265359'  File: python.info, Node: Old string formatting, Prev: Manual String Formatting, Up: Fancier Output Formatting 2.7.1.4 Old string formatting ............................. The % operator (modulo) can also be used for string formatting. Given ‘'string' % values’, instances of ‘%’ in ‘string’ are replaced with zero or more elements of ‘values’. This operation is commonly known as string interpolation. For example: >>> import math >>> print('The value of pi is approximately %5.3f.' % math.pi) The value of pi is approximately 3.142. More information can be found in the *note printf-style String Formatting: eb9. section.  File: python.info, Node: Reading and Writing Files, Prev: Fancier Output Formatting, Up: Input and Output 2.7.2 Reading and Writing Files ------------------------------- *note open(): 4f0. returns a *note file object: b42, and is most commonly used with two arguments: ‘open(filename, mode)’. >>> f = open('workfile', 'w') The first argument is a string containing the filename. The second argument is another string containing a few characters describing the way in which the file will be used. `mode' can be ‘'r'’ when the file will only be read, ‘'w'’ for only writing (an existing file with the same name will be erased), and ‘'a'’ opens the file for appending; any data written to the file is automatically added to the end. ‘'r+'’ opens the file for both reading and writing. The `mode' argument is optional; ‘'r'’ will be assumed if it’s omitted. Normally, files are opened in `text mode', that means, you read and write strings from and to the file, which are encoded in a specific encoding. If encoding is not specified, the default is platform dependent (see *note open(): 4f0.). ‘'b'’ appended to the mode opens the file in `binary mode': now the data is read and written in the form of bytes objects. This mode should be used for all files that don’t contain text. In text mode, the default when reading is to convert platform-specific line endings (‘\n’ on Unix, ‘\r\n’ on Windows) to just ‘\n’. When writing in text mode, the default is to convert occurrences of ‘\n’ back to platform-specific line endings. This behind-the-scenes modification to file data is fine for text files, but will corrupt binary data like that in ‘JPEG’ or ‘EXE’ files. Be very careful to use binary mode when reading and writing such files. It is good practice to use the *note with: 6e9. keyword when dealing with file objects. The advantage is that the file is properly closed after its suite finishes, even if an exception is raised at some point. Using ‘with’ is also much shorter than writing equivalent *note try: d72.-*note finally: 182. blocks: >>> with open('workfile') as f: ... read_data = f.read() >>> # We can check that the file has been automatically closed. >>> f.closed True If you’re not using the *note with: 6e9. keyword, then you should call ‘f.close()’ to close the file and immediately free up any system resources used by it. Warning: Calling ‘f.write()’ without using the ‘with’ keyword or calling ‘f.close()’ `might' result in the arguments of ‘f.write()’ not being completely written to the disk, even if the program exits successfully. After a file object is closed, either by a *note with: 6e9. statement or by calling ‘f.close()’, attempts to use the file object will automatically fail. >>> f.close() >>> f.read() Traceback (most recent call last): File "", line 1, in ValueError: I/O operation on closed file. * Menu: * Methods of File Objects:: * Saving structured data with json::  File: python.info, Node: Methods of File Objects, Next: Saving structured data with json, Up: Reading and Writing Files 2.7.2.1 Methods of File Objects ............................... The rest of the examples in this section will assume that a file object called ‘f’ has already been created. To read a file’s contents, call ‘f.read(size)’, which reads some quantity of data and returns it as a string (in text mode) or bytes object (in binary mode). `size' is an optional numeric argument. When `size' is omitted or negative, the entire contents of the file will be read and returned; it’s your problem if the file is twice as large as your machine’s memory. Otherwise, at most `size' characters (in text mode) or `size' bytes (in binary mode) are read and returned. If the end of the file has been reached, ‘f.read()’ will return an empty string (‘''’). >>> f.read() 'This is the entire file.\n' >>> f.read() '' ‘f.readline()’ reads a single line from the file; a newline character (‘\n’) is left at the end of the string, and is only omitted on the last line of the file if the file doesn’t end in a newline. This makes the return value unambiguous; if ‘f.readline()’ returns an empty string, the end of the file has been reached, while a blank line is represented by ‘'\n'’, a string containing only a single newline. >>> f.readline() 'This is the first line of the file.\n' >>> f.readline() 'Second line of the file\n' >>> f.readline() '' For reading lines from a file, you can loop over the file object. This is memory efficient, fast, and leads to simple code: >>> for line in f: ... print(line, end='') ... This is the first line of the file. Second line of the file If you want to read all the lines of a file in a list you can also use ‘list(f)’ or ‘f.readlines()’. ‘f.write(string)’ writes the contents of `string' to the file, returning the number of characters written. >>> f.write('This is a test\n') 15 Other types of objects need to be converted – either to a string (in text mode) or a bytes object (in binary mode) – before writing them: >>> value = ('the answer', 42) >>> s = str(value) # convert the tuple to string >>> f.write(s) 18 ‘f.tell()’ returns an integer giving the file object’s current position in the file represented as number of bytes from the beginning of the file when in binary mode and an opaque number when in text mode. To change the file object’s position, use ‘f.seek(offset, whence)’. The position is computed from adding `offset' to a reference point; the reference point is selected by the `whence' argument. A `whence' value of 0 measures from the beginning of the file, 1 uses the current file position, and 2 uses the end of the file as the reference point. `whence' can be omitted and defaults to 0, using the beginning of the file as the reference point. >>> f = open('workfile', 'rb+') >>> f.write(b'0123456789abcdef') 16 >>> f.seek(5) # Go to the 6th byte in the file 5 >>> f.read(1) b'5' >>> f.seek(-3, 2) # Go to the 3rd byte before the end 13 >>> f.read(1) b'd' In text files (those opened without a ‘b’ in the mode string), only seeks relative to the beginning of the file are allowed (the exception being seeking to the very file end with ‘seek(0, 2)’) and the only valid `offset' values are those returned from the ‘f.tell()’, or zero. Any other `offset' value produces undefined behaviour. File objects have some additional methods, such as ‘isatty()’ and ‘truncate()’ which are less frequently used; consult the Library Reference for a complete guide to file objects.  File: python.info, Node: Saving structured data with json, Prev: Methods of File Objects, Up: Reading and Writing Files 2.7.2.2 Saving structured data with ‘json’ .......................................... Strings can easily be written to and read from a file. Numbers take a bit more effort, since the ‘read()’ method only returns strings, which will have to be passed to a function like *note int(): 184, which takes a string like ‘'123'’ and returns its numeric value 123. When you want to save more complex data types like nested lists and dictionaries, parsing and serializing by hand becomes complicated. Rather than having users constantly writing and debugging code to save complicated data types to files, Python allows you to use the popular data interchange format called JSON (JavaScript Object Notation)(1). The standard module called *note json: a4. can take Python data hierarchies, and convert them to string representations; this process is called `serializing'. Reconstructing the data from the string representation is called `deserializing'. Between serializing and deserializing, the string representing the object may have been stored in a file or data, or sent over a network connection to some distant machine. Note: The JSON format is commonly used by modern applications to allow for data exchange. Many programmers are already familiar with it, which makes it a good choice for interoperability. If you have an object ‘x’, you can view its JSON string representation with a simple line of code: >>> import json >>> json.dumps([1, 'simple', 'list']) '[1, "simple", "list"]' Another variant of the *note dumps(): 605. function, called *note dump(): 604, simply serializes the object to a *note text file: f3a. So if ‘f’ is a *note text file: f3a. object opened for writing, we can do this: json.dump(x, f) To decode the object again, if ‘f’ is a *note text file: f3a. object which has been opened for reading: x = json.load(f) This simple serialization technique can handle lists and dictionaries, but serializing arbitrary class instances in JSON requires a bit of extra effort. The reference for the *note json: a4. module contains an explanation of this. See also ........ *note pickle: ca. - the pickle module Contrary to *note JSON: f39, `pickle' is a protocol which allows the serialization of arbitrarily complex Python objects. As such, it is specific to Python and cannot be used to communicate with applications written in other languages. It is also insecure by default: deserializing pickle data coming from an untrusted source can execute arbitrary code, if the data was crafted by a skilled attacker. ---------- Footnotes ---------- (1) http://json.org  File: python.info, Node: Errors and Exceptions, Next: Classes, Prev: Input and Output, Up: The Python Tutorial 2.8 Errors and Exceptions ========================= Until now error messages haven’t been more than mentioned, but if you have tried out the examples you have probably seen some. There are (at least) two distinguishable kinds of errors: `syntax errors' and `exceptions'. * Menu: * Syntax Errors:: * Exceptions:: * Handling Exceptions:: * Raising Exceptions:: * User-defined Exceptions:: * Defining Clean-up Actions:: * Predefined Clean-up Actions::  File: python.info, Node: Syntax Errors, Next: Exceptions, Up: Errors and Exceptions 2.8.1 Syntax Errors ------------------- Syntax errors, also known as parsing errors, are perhaps the most common kind of complaint you get while you are still learning Python: >>> while True print('Hello world') File "", line 1 while True print('Hello world') ^ SyntaxError: invalid syntax The parser repeats the offending line and displays a little ‘arrow’ pointing at the earliest point in the line where the error was detected. The error is caused by (or at least detected at) the token `preceding' the arrow: in the example, the error is detected at the function *note print(): 886, since a colon (‘':'’) is missing before it. File name and line number are printed so you know where to look in case the input came from a script.  File: python.info, Node: Exceptions, Next: Handling Exceptions, Prev: Syntax Errors, Up: Errors and Exceptions 2.8.2 Exceptions ---------------- Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Errors detected during execution are called `exceptions' and are not unconditionally fatal: you will soon learn how to handle them in Python programs. Most exceptions are not handled by programs, however, and result in error messages as shown here: >>> 10 * (1/0) Traceback (most recent call last): File "", line 1, in ZeroDivisionError: division by zero >>> 4 + spam*3 Traceback (most recent call last): File "", line 1, in NameError: name 'spam' is not defined >>> '2' + 2 Traceback (most recent call last): File "", line 1, in TypeError: Can't convert 'int' object to str implicitly The last line of the error message indicates what happened. Exceptions come in different types, and the type is printed as part of the message: the types in the example are *note ZeroDivisionError: f42, *note NameError: d7b. and *note TypeError: 192. The string printed as the exception type is the name of the built-in exception that occurred. This is true for all built-in exceptions, but need not be true for user-defined exceptions (although it is a useful convention). Standard exception names are built-in identifiers (not reserved keywords). The rest of the line provides detail based on the type of exception and what caused it. The preceding part of the error message shows the context where the exception happened, in the form of a stack traceback. In general it contains a stack traceback listing source lines; however, it will not display lines read from standard input. *note Built-in Exceptions: f43. lists the built-in exceptions and their meanings.  File: python.info, Node: Handling Exceptions, Next: Raising Exceptions, Prev: Exceptions, Up: Errors and Exceptions 2.8.3 Handling Exceptions ------------------------- It is possible to write programs that handle selected exceptions. Look at the following example, which asks the user for input until a valid integer has been entered, but allows the user to interrupt the program (using ‘Control-C’ or whatever the operating system supports); note that a user-generated interruption is signalled by raising the *note KeyboardInterrupt: 197. exception. >>> while True: ... try: ... x = int(input("Please enter a number: ")) ... break ... except ValueError: ... print("Oops! That was no valid number. Try again...") ... The *note try: d72. statement works as follows. * First, the `try clause' (the statement(s) between the *note try: d72. and *note except: b3e. keywords) is executed. * If no exception occurs, the `except clause' is skipped and execution of the *note try: d72. statement is finished. * If an exception occurs during execution of the try clause, the rest of the clause is skipped. Then if its type matches the exception named after the *note except: b3e. keyword, the except clause is executed, and then execution continues after the *note try: d72. statement. * If an exception occurs which does not match the exception named in the except clause, it is passed on to outer *note try: d72. statements; if no handler is found, it is an `unhandled exception' and execution stops with a message as shown above. A *note try: d72. statement may have more than one except clause, to specify handlers for different exceptions. At most one handler will be executed. Handlers only handle exceptions that occur in the corresponding try clause, not in other handlers of the same ‘try’ statement. An except clause may name multiple exceptions as a parenthesized tuple, for example: ... except (RuntimeError, TypeError, NameError): ... pass A class in an *note except: b3e. clause is compatible with an exception if it is the same class or a base class thereof (but not the other way around — an except clause listing a derived class is not compatible with a base class). For example, the following code will print B, C, D in that order: class B(Exception): pass class C(B): pass class D(C): pass for cls in [B, C, D]: try: raise cls() except D: print("D") except C: print("C") except B: print("B") Note that if the except clauses were reversed (with ‘except B’ first), it would have printed B, B, B — the first matching except clause is triggered. The last except clause may omit the exception name(s), to serve as a wildcard. Use this with extreme caution, since it is easy to mask a real programming error in this way! It can also be used to print an error message and then re-raise the exception (allowing a caller to handle the exception as well): import sys try: f = open('myfile.txt') s = f.readline() i = int(s.strip()) except OSError as err: print("OS error: {0}".format(err)) except ValueError: print("Could not convert data to an integer.") except: print("Unexpected error:", sys.exc_info()[0]) raise The *note try: d72. … *note except: b3e. statement has an optional `else clause', which, when present, must follow all except clauses. It is useful for code that must be executed if the try clause does not raise an exception. For example: for arg in sys.argv[1:]: try: f = open(arg, 'r') except OSError: print('cannot open', arg) else: print(arg, 'has', len(f.readlines()), 'lines') f.close() The use of the ‘else’ clause is better than adding additional code to the *note try: d72. clause because it avoids accidentally catching an exception that wasn’t raised by the code being protected by the ‘try’ … ‘except’ statement. When an exception occurs, it may have an associated value, also known as the exception’s `argument'. The presence and type of the argument depend on the exception type. The except clause may specify a variable after the exception name. The variable is bound to an exception instance with the arguments stored in ‘instance.args’. For convenience, the exception instance defines *note __str__(): e37. so the arguments can be printed directly without having to reference ‘.args’. One may also instantiate an exception first before raising it and add any attributes to it as desired. >>> try: ... raise Exception('spam', 'eggs') ... except Exception as inst: ... print(type(inst)) # the exception instance ... print(inst.args) # arguments stored in .args ... print(inst) # __str__ allows args to be printed directly, ... # but may be overridden in exception subclasses ... x, y = inst.args # unpack args ... print('x =', x) ... print('y =', y) ... ('spam', 'eggs') ('spam', 'eggs') x = spam y = eggs If an exception has arguments, they are printed as the last part (‘detail’) of the message for unhandled exceptions. Exception handlers don’t just handle exceptions if they occur immediately in the try clause, but also if they occur inside functions that are called (even indirectly) in the try clause. For example: >>> def this_fails(): ... x = 1/0 ... >>> try: ... this_fails() ... except ZeroDivisionError as err: ... print('Handling run-time error:', err) ... Handling run-time error: division by zero  File: python.info, Node: Raising Exceptions, Next: User-defined Exceptions, Prev: Handling Exceptions, Up: Errors and Exceptions 2.8.4 Raising Exceptions ------------------------ The *note raise: c42. statement allows the programmer to force a specified exception to occur. For example: >>> raise NameError('HiThere') Traceback (most recent call last): File "", line 1, in NameError: HiThere The sole argument to *note raise: c42. indicates the exception to be raised. This must be either an exception instance or an exception class (a class that derives from *note Exception: 1a9.). If an exception class is passed, it will be implicitly instantiated by calling its constructor with no arguments: raise ValueError # shorthand for 'raise ValueError()' If you need to determine whether an exception was raised but don’t intend to handle it, a simpler form of the *note raise: c42. statement allows you to re-raise the exception: >>> try: ... raise NameError('HiThere') ... except NameError: ... print('An exception flew by!') ... raise ... An exception flew by! Traceback (most recent call last): File "", line 2, in NameError: HiThere  File: python.info, Node: User-defined Exceptions, Next: Defining Clean-up Actions, Prev: Raising Exceptions, Up: Errors and Exceptions 2.8.5 User-defined Exceptions ----------------------------- Programs may name their own exceptions by creating a new exception class (see *note Classes: ed9. for more about Python classes). Exceptions should typically be derived from the *note Exception: 1a9. class, either directly or indirectly. Exception classes can be defined which do anything any other class can do, but are usually kept simple, often only offering a number of attributes that allow information about the error to be extracted by handlers for the exception. When creating a module that can raise several distinct errors, a common practice is to create a base class for exceptions defined by that module, and subclass that to create specific exception classes for different error conditions: class Error(Exception): """Base class for exceptions in this module.""" pass class InputError(Error): """Exception raised for errors in the input. Attributes: expression -- input expression in which the error occurred message -- explanation of the error """ def __init__(self, expression, message): self.expression = expression self.message = message class TransitionError(Error): """Raised when an operation attempts a state transition that's not allowed. Attributes: previous -- state at beginning of transition next -- attempted new state message -- explanation of why the specific transition is not allowed """ def __init__(self, previous, next, message): self.previous = previous self.next = next self.message = message Most exceptions are defined with names that end in “Error”, similar to the naming of the standard exceptions. Many standard modules define their own exceptions to report errors that may occur in functions they define. More information on classes is presented in chapter *note Classes: ed9.  File: python.info, Node: Defining Clean-up Actions, Next: Predefined Clean-up Actions, Prev: User-defined Exceptions, Up: Errors and Exceptions 2.8.6 Defining Clean-up Actions ------------------------------- The *note try: d72. statement has another optional clause which is intended to define clean-up actions that must be executed under all circumstances. For example: >>> try: ... raise KeyboardInterrupt ... finally: ... print('Goodbye, world!') ... Goodbye, world! Traceback (most recent call last): File "", line 2, in KeyboardInterrupt If a *note finally: 182. clause is present, the ‘finally’ clause will execute as the last task before the *note try: d72. statement completes. The ‘finally’ clause runs whether or not the ‘try’ statement produces an exception. The following points discuss more complex cases when an exception occurs: * If an exception occurs during execution of the ‘try’ clause, the exception may be handled by an *note except: b3e. clause. If the exception is not handled by an ‘except’ clause, the exception is re-raised after the ‘finally’ clause has been executed. * An exception could occur during execution of an ‘except’ or ‘else’ clause. Again, the exception is re-raised after the ‘finally’ clause has been executed. * If the ‘try’ statement reaches a *note break: 2db, *note continue: 181. or *note return: 190. statement, the ‘finally’ clause will execute just prior to the ‘break’, ‘continue’ or ‘return’ statement’s execution. * If a ‘finally’ clause includes a ‘return’ statement, the returned value will be the one from the ‘finally’ clause’s ‘return’ statement, not the value from the ‘try’ clause’s ‘return’ statement. For example: >>> def bool_return(): ... try: ... return True ... finally: ... return False ... >>> bool_return() False A more complicated example: >>> def divide(x, y): ... try: ... result = x / y ... except ZeroDivisionError: ... print("division by zero!") ... else: ... print("result is", result) ... finally: ... print("executing finally clause") ... >>> divide(2, 1) result is 2.0 executing finally clause >>> divide(2, 0) division by zero! executing finally clause >>> divide("2", "1") executing finally clause Traceback (most recent call last): File "", line 1, in File "", line 3, in divide TypeError: unsupported operand type(s) for /: 'str' and 'str' As you can see, the *note finally: 182. clause is executed in any event. The *note TypeError: 192. raised by dividing two strings is not handled by the *note except: b3e. clause and therefore re-raised after the ‘finally’ clause has been executed. In real world applications, the *note finally: 182. clause is useful for releasing external resources (such as files or network connections), regardless of whether the use of the resource was successful.  File: python.info, Node: Predefined Clean-up Actions, Prev: Defining Clean-up Actions, Up: Errors and Exceptions 2.8.7 Predefined Clean-up Actions --------------------------------- Some objects define standard clean-up actions to be undertaken when the object is no longer needed, regardless of whether or not the operation using the object succeeded or failed. Look at the following example, which tries to open a file and print its contents to the screen. for line in open("myfile.txt"): print(line, end="") The problem with this code is that it leaves the file open for an indeterminate amount of time after this part of the code has finished executing. This is not an issue in simple scripts, but can be a problem for larger applications. The *note with: 6e9. statement allows objects like files to be used in a way that ensures they are always cleaned up promptly and correctly. with open("myfile.txt") as f: for line in f: print(line, end="") After the statement is executed, the file `f' is always closed, even if a problem was encountered while processing the lines. Objects which, like files, provide predefined clean-up actions will indicate this in their documentation.  File: python.info, Node: Classes, Next: Brief Tour of the Standard Library, Prev: Errors and Exceptions, Up: The Python Tutorial 2.9 Classes =========== Classes provide a means of bundling data and functionality together. Creating a new class creates a new `type' of object, allowing new `instances' of that type to be made. Each class instance can have attributes attached to it for maintaining its state. Class instances can also have methods (defined by its class) for modifying its state. Compared with other programming languages, Python’s class mechanism adds classes with a minimum of new syntax and semantics. It is a mixture of the class mechanisms found in C++ and Modula-3. Python classes provide all the standard features of Object Oriented Programming: the class inheritance mechanism allows multiple base classes, a derived class can override any methods of its base class or classes, and a method can call the method of a base class with the same name. Objects can contain arbitrary amounts and kinds of data. As is true for modules, classes partake of the dynamic nature of Python: they are created at runtime, and can be modified further after creation. In C++ terminology, normally class members (including the data members) are `public' (except see below *note Private Variables: f4f.), and all member functions are `virtual'. As in Modula-3, there are no shorthands for referencing the object’s members from its methods: the method function is declared with an explicit first argument representing the object, which is provided implicitly by the call. As in Smalltalk, classes themselves are objects. This provides semantics for importing and renaming. Unlike C++ and Modula-3, built-in types can be used as base classes for extension by the user. Also, like in C++, most built-in operators with special syntax (arithmetic operators, subscripting etc.) can be redefined for class instances. (Lacking universally accepted terminology to talk about classes, I will make occasional use of Smalltalk and C++ terms. I would use Modula-3 terms, since its object-oriented semantics are closer to those of Python than C++, but I expect that few readers have heard of it.) * Menu: * A Word About Names and Objects:: * Python Scopes and Namespaces:: * A First Look at Classes:: * Random Remarks:: * Inheritance:: * Private Variables:: * Odds and Ends:: * Iterators:: * Generators:: * Generator Expressions::  File: python.info, Node: A Word About Names and Objects, Next: Python Scopes and Namespaces, Up: Classes 2.9.1 A Word About Names and Objects ------------------------------------ Objects have individuality, and multiple names (in multiple scopes) can be bound to the same object. This is known as aliasing in other languages. This is usually not appreciated on a first glance at Python, and can be safely ignored when dealing with immutable basic types (numbers, strings, tuples). However, aliasing has a possibly surprising effect on the semantics of Python code involving mutable objects such as lists, dictionaries, and most other types. This is usually used to the benefit of the program, since aliases behave like pointers in some respects. For example, passing an object is cheap since only a pointer is passed by the implementation; and if a function modifies an object passed as an argument, the caller will see the change — this eliminates the need for two different argument passing mechanisms as in Pascal.  File: python.info, Node: Python Scopes and Namespaces, Next: A First Look at Classes, Prev: A Word About Names and Objects, Up: Classes 2.9.2 Python Scopes and Namespaces ---------------------------------- Before introducing classes, I first have to tell you something about Python’s scope rules. Class definitions play some neat tricks with namespaces, and you need to know how scopes and namespaces work to fully understand what’s going on. Incidentally, knowledge about this subject is useful for any advanced Python programmer. Let’s begin with some definitions. A `namespace' is a mapping from names to objects. Most namespaces are currently implemented as Python dictionaries, but that’s normally not noticeable in any way (except for performance), and it may change in the future. Examples of namespaces are: the set of built-in names (containing functions such as *note abs(): f54, and built-in exception names); the global names in a module; and the local names in a function invocation. In a sense the set of attributes of an object also form a namespace. The important thing to know about namespaces is that there is absolutely no relation between names in different namespaces; for instance, two different modules may both define a function ‘maximize’ without confusion — users of the modules must prefix it with the module name. By the way, I use the word `attribute' for any name following a dot — for example, in the expression ‘z.real’, ‘real’ is an attribute of the object ‘z’. Strictly speaking, references to names in modules are attribute references: in the expression ‘modname.funcname’, ‘modname’ is a module object and ‘funcname’ is an attribute of it. In this case there happens to be a straightforward mapping between the module’s attributes and the global names defined in the module: they share the same namespace! (1) Attributes may be read-only or writable. In the latter case, assignment to attributes is possible. Module attributes are writable: you can write ‘modname.the_answer = 42’. Writable attributes may also be deleted with the *note del: f02. statement. For example, ‘del modname.the_answer’ will remove the attribute ‘the_answer’ from the object named by ‘modname’. Namespaces are created at different moments and have different lifetimes. The namespace containing the built-in names is created when the Python interpreter starts up, and is never deleted. The global namespace for a module is created when the module definition is read in; normally, module namespaces also last until the interpreter quits. The statements executed by the top-level invocation of the interpreter, either read from a script file or interactively, are considered part of a module called *note __main__: 1, so they have their own global namespace. (The built-in names actually also live in a module; this is called *note builtins: 13.) The local namespace for a function is created when the function is called, and deleted when the function returns or raises an exception that is not handled within the function. (Actually, forgetting would be a better way to describe what actually happens.) Of course, recursive invocations each have their own local namespace. A `scope' is a textual region of a Python program where a namespace is directly accessible. “Directly accessible” here means that an unqualified reference to a name attempts to find the name in the namespace. Although scopes are determined statically, they are used dynamically. At any time during execution, there are 3 or 4 nested scopes whose namespaces are directly accessible: * the innermost scope, which is searched first, contains the local names * the scopes of any enclosing functions, which are searched starting with the nearest enclosing scope, contains non-local, but also non-global names * the next-to-last scope contains the current module’s global names * the outermost scope (searched last) is the namespace containing built-in names If a name is declared global, then all references and assignments go directly to the middle scope containing the module’s global names. To rebind variables found outside of the innermost scope, the *note nonlocal: c3f. statement can be used; if not declared nonlocal, those variables are read-only (an attempt to write to such a variable will simply create a `new' local variable in the innermost scope, leaving the identically named outer variable unchanged). Usually, the local scope references the local names of the (textually) current function. Outside functions, the local scope references the same namespace as the global scope: the module’s namespace. Class definitions place yet another namespace in the local scope. It is important to realize that scopes are determined textually: the global scope of a function defined in a module is that module’s namespace, no matter from where or by what alias the function is called. On the other hand, the actual search for names is done dynamically, at run time — however, the language definition is evolving towards static name resolution, at “compile” time, so don’t rely on dynamic name resolution! (In fact, local variables are already determined statically.) A special quirk of Python is that – if no *note global: ed8. or *note nonlocal: c3f. statement is in effect – assignments to names always go into the innermost scope. Assignments do not copy data — they just bind names to objects. The same is true for deletions: the statement ‘del x’ removes the binding of ‘x’ from the namespace referenced by the local scope. In fact, all operations that introduce new names use the local scope: in particular, *note import: c1d. statements and function definitions bind the module or function name in the local scope. The *note global: ed8. statement can be used to indicate that particular variables live in the global scope and should be rebound there; the *note nonlocal: c3f. statement indicates that particular variables live in an enclosing scope and should be rebound there. * Menu: * Scopes and Namespaces Example:: ---------- Footnotes ---------- (1) (1) Except for one thing. Module objects have a secret read-only attribute called *note __dict__: 4fc. which returns the dictionary used to implement the module’s namespace; the name *note __dict__: 4fc. is an attribute but not a global name. Obviously, using this violates the abstraction of namespace implementation, and should be restricted to things like post-mortem debuggers.  File: python.info, Node: Scopes and Namespaces Example, Up: Python Scopes and Namespaces 2.9.2.1 Scopes and Namespaces Example ..................................... This is an example demonstrating how to reference the different scopes and namespaces, and how *note global: ed8. and *note nonlocal: c3f. affect variable binding: def scope_test(): def do_local(): spam = "local spam" def do_nonlocal(): nonlocal spam spam = "nonlocal spam" def do_global(): global spam spam = "global spam" spam = "test spam" do_local() print("After local assignment:", spam) do_nonlocal() print("After nonlocal assignment:", spam) do_global() print("After global assignment:", spam) scope_test() print("In global scope:", spam) The output of the example code is: After local assignment: test spam After nonlocal assignment: nonlocal spam After global assignment: nonlocal spam In global scope: global spam Note how the `local' assignment (which is default) didn’t change `scope_test'’s binding of `spam'. The *note nonlocal: c3f. assignment changed `scope_test'’s binding of `spam', and the *note global: ed8. assignment changed the module-level binding. You can also see that there was no previous binding for `spam' before the *note global: ed8. assignment.  File: python.info, Node: A First Look at Classes, Next: Random Remarks, Prev: Python Scopes and Namespaces, Up: Classes 2.9.3 A First Look at Classes ----------------------------- Classes introduce a little bit of new syntax, three new object types, and some new semantics. * Menu: * Class Definition Syntax:: * Class Objects:: * Instance Objects:: * Method Objects:: * Class and Instance Variables::  File: python.info, Node: Class Definition Syntax, Next: Class Objects, Up: A First Look at Classes 2.9.3.1 Class Definition Syntax ............................... The simplest form of class definition looks like this: class ClassName: . . . Class definitions, like function definitions (*note def: dbe. statements) must be executed before they have any effect. (You could conceivably place a class definition in a branch of an *note if: de7. statement, or inside a function.) In practice, the statements inside a class definition will usually be function definitions, but other statements are allowed, and sometimes useful — we’ll come back to this later. The function definitions inside a class normally have a peculiar form of argument list, dictated by the calling conventions for methods — again, this is explained later. When a class definition is entered, a new namespace is created, and used as the local scope — thus, all assignments to local variables go into this new namespace. In particular, function definitions bind the name of the new function here. When a class definition is left normally (via the end), a `class object' is created. This is basically a wrapper around the contents of the namespace created by the class definition; we’ll learn more about class objects in the next section. The original local scope (the one in effect just before the class definition was entered) is reinstated, and the class object is bound here to the class name given in the class definition header (‘ClassName’ in the example).  File: python.info, Node: Class Objects, Next: Instance Objects, Prev: Class Definition Syntax, Up: A First Look at Classes 2.9.3.2 Class Objects ..................... Class objects support two kinds of operations: attribute references and instantiation. `Attribute references' use the standard syntax used for all attribute references in Python: ‘obj.name’. Valid attribute names are all the names that were in the class’s namespace when the class object was created. So, if the class definition looked like this: class MyClass: """A simple example class""" i = 12345 def f(self): return 'hello world' then ‘MyClass.i’ and ‘MyClass.f’ are valid attribute references, returning an integer and a function object, respectively. Class attributes can also be assigned to, so you can change the value of ‘MyClass.i’ by assignment. ‘__doc__’ is also a valid attribute, returning the docstring belonging to the class: ‘"A simple example class"’. Class `instantiation' uses function notation. Just pretend that the class object is a parameterless function that returns a new instance of the class. For example (assuming the above class): x = MyClass() creates a new `instance' of the class and assigns this object to the local variable ‘x’. The instantiation operation (“calling” a class object) creates an empty object. Many classes like to create objects with instances customized to a specific initial state. Therefore a class may define a special method named *note __init__(): d5e, like this: def __init__(self): self.data = [] When a class defines an *note __init__(): d5e. method, class instantiation automatically invokes *note __init__(): d5e. for the newly-created class instance. So in this example, a new, initialized instance can be obtained by: x = MyClass() Of course, the *note __init__(): d5e. method may have arguments for greater flexibility. In that case, arguments given to the class instantiation operator are passed on to *note __init__(): d5e. For example, >>> class Complex: ... def __init__(self, realpart, imagpart): ... self.r = realpart ... self.i = imagpart ... >>> x = Complex(3.0, -4.5) >>> x.r, x.i (3.0, -4.5)  File: python.info, Node: Instance Objects, Next: Method Objects, Prev: Class Objects, Up: A First Look at Classes 2.9.3.3 Instance Objects ........................ Now what can we do with instance objects? The only operations understood by instance objects are attribute references. There are two kinds of valid attribute names: data attributes and methods. `data attributes' correspond to “instance variables” in Smalltalk, and to “data members” in C++. Data attributes need not be declared; like local variables, they spring into existence when they are first assigned to. For example, if ‘x’ is the instance of ‘MyClass’ created above, the following piece of code will print the value ‘16’, without leaving a trace: x.counter = 1 while x.counter < 10: x.counter = x.counter * 2 print(x.counter) del x.counter The other kind of instance attribute reference is a `method'. A method is a function that “belongs to” an object. (In Python, the term method is not unique to class instances: other object types can have methods as well. For example, list objects have methods called append, insert, remove, sort, and so on. However, in the following discussion, we’ll use the term method exclusively to mean methods of class instance objects, unless explicitly stated otherwise.) Valid method names of an instance object depend on its class. By definition, all attributes of a class that are function objects define corresponding methods of its instances. So in our example, ‘x.f’ is a valid method reference, since ‘MyClass.f’ is a function, but ‘x.i’ is not, since ‘MyClass.i’ is not. But ‘x.f’ is not the same thing as ‘MyClass.f’ — it is a `method object', not a function object.  File: python.info, Node: Method Objects, Next: Class and Instance Variables, Prev: Instance Objects, Up: A First Look at Classes 2.9.3.4 Method Objects ...................... Usually, a method is called right after it is bound: x.f() In the ‘MyClass’ example, this will return the string ‘'hello world'’. However, it is not necessary to call a method right away: ‘x.f’ is a method object, and can be stored away and called at a later time. For example: xf = x.f while True: print(xf()) will continue to print ‘hello world’ until the end of time. What exactly happens when a method is called? You may have noticed that ‘x.f()’ was called without an argument above, even though the function definition for ‘f()’ specified an argument. What happened to the argument? Surely Python raises an exception when a function that requires an argument is called without any — even if the argument isn’t actually used… Actually, you may have guessed the answer: the special thing about methods is that the instance object is passed as the first argument of the function. In our example, the call ‘x.f()’ is exactly equivalent to ‘MyClass.f(x)’. In general, calling a method with a list of `n' arguments is equivalent to calling the corresponding function with an argument list that is created by inserting the method’s instance object before the first argument. If you still don’t understand how methods work, a look at the implementation can perhaps clarify matters. When a non-data attribute of an instance is referenced, the instance’s class is searched. If the name denotes a valid class attribute that is a function object, a method object is created by packing (pointers to) the instance object and the function object just found together in an abstract object: this is the method object. When the method object is called with an argument list, a new argument list is constructed from the instance object and the argument list, and the function object is called with this new argument list.  File: python.info, Node: Class and Instance Variables, Prev: Method Objects, Up: A First Look at Classes 2.9.3.5 Class and Instance Variables .................................... Generally speaking, instance variables are for data unique to each instance and class variables are for attributes and methods shared by all instances of the class: class Dog: kind = 'canine' # class variable shared by all instances def __init__(self, name): self.name = name # instance variable unique to each instance >>> d = Dog('Fido') >>> e = Dog('Buddy') >>> d.kind # shared by all dogs 'canine' >>> e.kind # shared by all dogs 'canine' >>> d.name # unique to d 'Fido' >>> e.name # unique to e 'Buddy' As discussed in *note A Word About Names and Objects: f51, shared data can have possibly surprising effects with involving *note mutable: ebe. objects such as lists and dictionaries. For example, the `tricks' list in the following code should not be used as a class variable because just a single list would be shared by all `Dog' instances: class Dog: tricks = [] # mistaken use of a class variable def __init__(self, name): self.name = name def add_trick(self, trick): self.tricks.append(trick) >>> d = Dog('Fido') >>> e = Dog('Buddy') >>> d.add_trick('roll over') >>> e.add_trick('play dead') >>> d.tricks # unexpectedly shared by all dogs ['roll over', 'play dead'] Correct design of the class should use an instance variable instead: class Dog: def __init__(self, name): self.name = name self.tricks = [] # creates a new empty list for each dog def add_trick(self, trick): self.tricks.append(trick) >>> d = Dog('Fido') >>> e = Dog('Buddy') >>> d.add_trick('roll over') >>> e.add_trick('play dead') >>> d.tricks ['roll over'] >>> e.tricks ['play dead']  File: python.info, Node: Random Remarks, Next: Inheritance, Prev: A First Look at Classes, Up: Classes 2.9.4 Random Remarks -------------------- If the same attribute name occurs in both an instance and in a class, then attribute lookup prioritizes the instance: >>> class Warehouse: purpose = 'storage' region = 'west' >>> w1 = Warehouse() >>> print(w1.purpose, w1.region) storage west >>> w2 = Warehouse() >>> w2.region = 'east' >>> print(w2.purpose, w2.region) storage east Data attributes may be referenced by methods as well as by ordinary users (“clients”) of an object. In other words, classes are not usable to implement pure abstract data types. In fact, nothing in Python makes it possible to enforce data hiding — it is all based upon convention. (On the other hand, the Python implementation, written in C, can completely hide implementation details and control access to an object if necessary; this can be used by extensions to Python written in C.) Clients should use data attributes with care — clients may mess up invariants maintained by the methods by stamping on their data attributes. Note that clients may add data attributes of their own to an instance object without affecting the validity of the methods, as long as name conflicts are avoided — again, a naming convention can save a lot of headaches here. There is no shorthand for referencing data attributes (or other methods!) from within methods. I find that this actually increases the readability of methods: there is no chance of confusing local variables and instance variables when glancing through a method. Often, the first argument of a method is called ‘self’. This is nothing more than a convention: the name ‘self’ has absolutely no special meaning to Python. Note, however, that by not following the convention your code may be less readable to other Python programmers, and it is also conceivable that a `class browser' program might be written that relies upon such a convention. Any function object that is a class attribute defines a method for instances of that class. It is not necessary that the function definition is textually enclosed in the class definition: assigning a function object to a local variable in the class is also ok. For example: # Function defined outside the class def f1(self, x, y): return min(x, x+y) class C: f = f1 def g(self): return 'hello world' h = g Now ‘f’, ‘g’ and ‘h’ are all attributes of class ‘C’ that refer to function objects, and consequently they are all methods of instances of ‘C’ — ‘h’ being exactly equivalent to ‘g’. Note that this practice usually only serves to confuse the reader of a program. Methods may call other methods by using method attributes of the ‘self’ argument: class Bag: def __init__(self): self.data = [] def add(self, x): self.data.append(x) def addtwice(self, x): self.add(x) self.add(x) Methods may reference global names in the same way as ordinary functions. The global scope associated with a method is the module containing its definition. (A class is never used as a global scope.) While one rarely encounters a good reason for using global data in a method, there are many legitimate uses of the global scope: for one thing, functions and modules imported into the global scope can be used by methods, as well as functions and classes defined in it. Usually, the class containing the method is itself defined in this global scope, and in the next section we’ll find some good reasons why a method would want to reference its own class. Each value is an object, and therefore has a `class' (also called its `type'). It is stored as ‘object.__class__’.  File: python.info, Node: Inheritance, Next: Private Variables, Prev: Random Remarks, Up: Classes 2.9.5 Inheritance ----------------- Of course, a language feature would not be worthy of the name “class” without supporting inheritance. The syntax for a derived class definition looks like this: class DerivedClassName(BaseClassName): . . . The name ‘BaseClassName’ must be defined in a scope containing the derived class definition. In place of a base class name, other arbitrary expressions are also allowed. This can be useful, for example, when the base class is defined in another module: class DerivedClassName(modname.BaseClassName): Execution of a derived class definition proceeds the same as for a base class. When the class object is constructed, the base class is remembered. This is used for resolving attribute references: if a requested attribute is not found in the class, the search proceeds to look in the base class. This rule is applied recursively if the base class itself is derived from some other class. There’s nothing special about instantiation of derived classes: ‘DerivedClassName()’ creates a new instance of the class. Method references are resolved as follows: the corresponding class attribute is searched, descending down the chain of base classes if necessary, and the method reference is valid if this yields a function object. Derived classes may override methods of their base classes. Because methods have no special privileges when calling other methods of the same object, a method of a base class that calls another method defined in the same base class may end up calling a method of a derived class that overrides it. (For C++ programmers: all methods in Python are effectively ‘virtual’.) An overriding method in a derived class may in fact want to extend rather than simply replace the base class method of the same name. There is a simple way to call the base class method directly: just call ‘BaseClassName.methodname(self, arguments)’. This is occasionally useful to clients as well. (Note that this only works if the base class is accessible as ‘BaseClassName’ in the global scope.) Python has two built-in functions that work with inheritance: * Use *note isinstance(): 44f. to check an instance’s type: ‘isinstance(obj, int)’ will be ‘True’ only if ‘obj.__class__’ is *note int: 184. or some class derived from *note int: 184. * Use *note issubclass(): 450. to check class inheritance: ‘issubclass(bool, int)’ is ‘True’ since *note bool: 183. is a subclass of *note int: 184. However, ‘issubclass(float, int)’ is ‘False’ since *note float: 187. is not a subclass of *note int: 184. * Menu: * Multiple Inheritance::  File: python.info, Node: Multiple Inheritance, Up: Inheritance 2.9.5.1 Multiple Inheritance ............................ Python supports a form of multiple inheritance as well. A class definition with multiple base classes looks like this: class DerivedClassName(Base1, Base2, Base3): . . . For most purposes, in the simplest cases, you can think of the search for attributes inherited from a parent class as depth-first, left-to-right, not searching twice in the same class where there is an overlap in the hierarchy. Thus, if an attribute is not found in ‘DerivedClassName’, it is searched for in ‘Base1’, then (recursively) in the base classes of ‘Base1’, and if it was not found there, it was searched for in ‘Base2’, and so on. In fact, it is slightly more complex than that; the method resolution order changes dynamically to support cooperative calls to *note super(): 4e2. This approach is known in some other multiple-inheritance languages as call-next-method and is more powerful than the super call found in single-inheritance languages. Dynamic ordering is necessary because all cases of multiple inheritance exhibit one or more diamond relationships (where at least one of the parent classes can be accessed through multiple paths from the bottommost class). For example, all classes inherit from *note object: 2b0, so any case of multiple inheritance provides more than one path to reach *note object: 2b0. To keep the base classes from being accessed more than once, the dynamic algorithm linearizes the search order in a way that preserves the left-to-right ordering specified in each class, that calls each parent only once, and that is monotonic (meaning that a class can be subclassed without affecting the precedence order of its parents). Taken together, these properties make it possible to design reliable and extensible classes with multiple inheritance. For more detail, see ‘https://www.python.org/download/releases/2.3/mro/’.  File: python.info, Node: Private Variables, Next: Odds and Ends, Prev: Inheritance, Up: Classes 2.9.6 Private Variables ----------------------- “Private” instance variables that cannot be accessed except from inside an object don’t exist in Python. However, there is a convention that is followed by most Python code: a name prefixed with an underscore (e.g. ‘_spam’) should be treated as a non-public part of the API (whether it is a function, a method or a data member). It should be considered an implementation detail and subject to change without notice. Since there is a valid use-case for class-private members (namely to avoid name clashes of names with names defined by subclasses), there is limited support for such a mechanism, called `name mangling'. Any identifier of the form ‘__spam’ (at least two leading underscores, at most one trailing underscore) is textually replaced with ‘_classname__spam’, where ‘classname’ is the current class name with leading underscore(s) stripped. This mangling is done without regard to the syntactic position of the identifier, as long as it occurs within the definition of a class. Name mangling is helpful for letting subclasses override methods without breaking intraclass method calls. For example: class Mapping: def __init__(self, iterable): self.items_list = [] self.__update(iterable) def update(self, iterable): for item in iterable: self.items_list.append(item) __update = update # private copy of original update() method class MappingSubclass(Mapping): def update(self, keys, values): # provides new signature for update() # but does not break __init__() for item in zip(keys, values): self.items_list.append(item) The above example would work even if ‘MappingSubclass’ were to introduce a ‘__update’ identifier since it is replaced with ‘_Mapping__update’ in the ‘Mapping’ class and ‘_MappingSubclass__update’ in the ‘MappingSubclass’ class respectively. Note that the mangling rules are designed mostly to avoid accidents; it still is possible to access or modify a variable that is considered private. This can even be useful in special circumstances, such as in the debugger. Notice that code passed to ‘exec()’ or ‘eval()’ does not consider the classname of the invoking class to be the current class; this is similar to the effect of the ‘global’ statement, the effect of which is likewise restricted to code that is byte-compiled together. The same restriction applies to ‘getattr()’, ‘setattr()’ and ‘delattr()’, as well as when referencing ‘__dict__’ directly.  File: python.info, Node: Odds and Ends, Next: Iterators, Prev: Private Variables, Up: Classes 2.9.7 Odds and Ends ------------------- Sometimes it is useful to have a data type similar to the Pascal “record” or C “struct”, bundling together a few named data items. An empty class definition will do nicely: class Employee: pass john = Employee() # Create an empty employee record # Fill the fields of the record john.name = 'John Doe' john.dept = 'computer lab' john.salary = 1000 A piece of Python code that expects a particular abstract data type can often be passed a class that emulates the methods of that data type instead. For instance, if you have a function that formats some data from a file object, you can define a class with methods ‘read()’ and ‘readline()’ that get the data from a string buffer instead, and pass it as an argument. Instance method objects have attributes, too: ‘m.__self__’ is the instance object with the method ‘m()’, and ‘m.__func__’ is the function object corresponding to the method.  File: python.info, Node: Iterators, Next: Generators, Prev: Odds and Ends, Up: Classes 2.9.8 Iterators --------------- By now you have probably noticed that most container objects can be looped over using a *note for: c30. statement: for element in [1, 2, 3]: print(element) for element in (1, 2, 3): print(element) for key in {'one':1, 'two':2}: print(key) for char in "123": print(char) for line in open("myfile.txt"): print(line, end='') This style of access is clear, concise, and convenient. The use of iterators pervades and unifies Python. Behind the scenes, the *note for: c30. statement calls *note iter(): d27. on the container object. The function returns an iterator object that defines the method *note __next__(): c64. which accesses elements in the container one at a time. When there are no more elements, *note __next__(): c64. raises a *note StopIteration: 486. exception which tells the ‘for’ loop to terminate. You can call the *note __next__(): c64. method using the *note next(): 682. built-in function; this example shows how it all works: >>> s = 'abc' >>> it = iter(s) >>> it >>> next(it) 'a' >>> next(it) 'b' >>> next(it) 'c' >>> next(it) Traceback (most recent call last): File "", line 1, in next(it) StopIteration Having seen the mechanics behind the iterator protocol, it is easy to add iterator behavior to your classes. Define an *note __iter__(): 50f. method which returns an object with a *note __next__(): c64. method. If the class defines ‘__next__()’, then *note __iter__(): 50f. can just return ‘self’: class Reverse: """Iterator for looping over a sequence backwards.""" def __init__(self, data): self.data = data self.index = len(data) def __iter__(self): return self def __next__(self): if self.index == 0: raise StopIteration self.index = self.index - 1 return self.data[self.index] >>> rev = Reverse('spam') >>> iter(rev) <__main__.Reverse object at 0x00A1DB50> >>> for char in rev: ... print(char) ... m a p s  File: python.info, Node: Generators, Next: Generator Expressions, Prev: Iterators, Up: Classes 2.9.9 Generators ---------------- *note Generators: 9a2. are a simple and powerful tool for creating iterators. They are written like regular functions but use the *note yield: 18f. statement whenever they want to return data. Each time *note next(): 682. is called on it, the generator resumes where it left off (it remembers all the data values and which statement was last executed). An example shows that generators can be trivially easy to create: def reverse(data): for index in range(len(data)-1, -1, -1): yield data[index] >>> for char in reverse('golf'): ... print(char) ... f l o g Anything that can be done with generators can also be done with class-based iterators as described in the previous section. What makes generators so compact is that the *note __iter__(): 50f. and *note __next__(): f6f. methods are created automatically. Another key feature is that the local variables and execution state are automatically saved between calls. This made the function easier to write and much more clear than an approach using instance variables like ‘self.index’ and ‘self.data’. In addition to automatic method creation and saving program state, when generators terminate, they automatically raise *note StopIteration: 486. In combination, these features make it easy to create iterators with no more effort than writing a regular function.  File: python.info, Node: Generator Expressions, Prev: Generators, Up: Classes 2.9.10 Generator Expressions ---------------------------- Some simple generators can be coded succinctly as expressions using a syntax similar to list comprehensions but with parentheses instead of square brackets. These expressions are designed for situations where the generator is used right away by an enclosing function. Generator expressions are more compact but less versatile than full generator definitions and tend to be more memory friendly than equivalent list comprehensions. Examples: >>> sum(i*i for i in range(10)) # sum of squares 285 >>> xvec = [10, 20, 30] >>> yvec = [7, 5, 3] >>> sum(x*y for x,y in zip(xvec, yvec)) # dot product 260 >>> unique_words = set(word for line in page for word in line.split()) >>> valedictorian = max((student.gpa, student.name) for student in graduates) >>> data = 'golf' >>> list(data[i] for i in range(len(data)-1, -1, -1)) ['f', 'l', 'o', 'g']  File: python.info, Node: Brief Tour of the Standard Library, Next: Brief Tour of the Standard Library — Part II, Prev: Classes, Up: The Python Tutorial 2.10 Brief Tour of the Standard Library ======================================= * Menu: * Operating System Interface:: * File Wildcards:: * Command Line Arguments:: * Error Output Redirection and Program Termination:: * String Pattern Matching:: * Mathematics:: * Internet Access:: * Dates and Times:: * Data Compression:: * Performance Measurement:: * Quality Control:: * Batteries Included::  File: python.info, Node: Operating System Interface, Next: File Wildcards, Up: Brief Tour of the Standard Library 2.10.1 Operating System Interface --------------------------------- The *note os: c4. module provides dozens of functions for interacting with the operating system: >>> import os >>> os.getcwd() # Return the current working directory 'C:\\Python38' >>> os.chdir('/server/accesslogs') # Change current working directory >>> os.system('mkdir today') # Run the command mkdir in the system shell 0 Be sure to use the ‘import os’ style instead of ‘from os import *’. This will keep *note os.open(): 665. from shadowing the built-in *note open(): 4f0. function which operates much differently. The built-in *note dir(): d33. and *note help(): 572. functions are useful as interactive aids for working with large modules like *note os: c4.: >>> import os >>> dir(os) >>> help(os) For daily file and directory management tasks, the *note shutil: e9. module provides a higher level interface that is easier to use: >>> import shutil >>> shutil.copyfile('data.db', 'archive.db') 'archive.db' >>> shutil.move('/build/executables', 'installdir') 'installdir'  File: python.info, Node: File Wildcards, Next: Command Line Arguments, Prev: Operating System Interface, Up: Brief Tour of the Standard Library 2.10.2 File Wildcards --------------------- The *note glob: 8a. module provides a function for making file lists from directory wildcard searches: >>> import glob >>> glob.glob('*.py') ['primes.py', 'random.py', 'quote.py']  File: python.info, Node: Command Line Arguments, Next: Error Output Redirection and Program Termination, Prev: File Wildcards, Up: Brief Tour of the Standard Library 2.10.3 Command Line Arguments ----------------------------- Common utility scripts often need to process command line arguments. These arguments are stored in the *note sys: fd. module’s `argv' attribute as a list. For instance the following output results from running ‘python demo.py one two three’ at the command line: >>> import sys >>> print(sys.argv) ['demo.py', 'one', 'two', 'three'] The *note argparse: 6. module provides a more sophisticated mechanism to process command line arguments. The following script extracts one or more filenames and an optional number of lines to be displayed: import argparse parser = argparse.ArgumentParser(prog = 'top', description = 'Show top lines from each file') parser.add_argument('filenames', nargs='+') parser.add_argument('-l', '--lines', type=int, default=10) args = parser.parse_args() print(args) When run at the command line with ‘python top.py --lines=5 alpha.txt beta.txt’, the script sets ‘args.lines’ to ‘5’ and ‘args.filenames’ to ‘['alpha.txt', 'beta.txt']’.  File: python.info, Node: Error Output Redirection and Program Termination, Next: String Pattern Matching, Prev: Command Line Arguments, Up: Brief Tour of the Standard Library 2.10.4 Error Output Redirection and Program Termination ------------------------------------------------------- The *note sys: fd. module also has attributes for `stdin', `stdout', and `stderr'. The latter is useful for emitting warnings and error messages to make them visible even when `stdout' has been redirected: >>> sys.stderr.write('Warning, log file not found starting a new one\n') Warning, log file not found starting a new one The most direct way to terminate a script is to use ‘sys.exit()’.  File: python.info, Node: String Pattern Matching, Next: Mathematics, Prev: Error Output Redirection and Program Termination, Up: Brief Tour of the Standard Library 2.10.5 String Pattern Matching ------------------------------ The *note re: dd. module provides regular expression tools for advanced string processing. For complex matching and manipulation, regular expressions offer succinct, optimized solutions: >>> import re >>> re.findall(r'\bf[a-z]*', 'which foot or hand fell fastest') ['foot', 'fell', 'fastest'] >>> re.sub(r'(\b[a-z]+) \1', r'\1', 'cat in the the hat') 'cat in the hat' When only simple capabilities are needed, string methods are preferred because they are easier to read and debug: >>> 'tea for too'.replace('too', 'two') 'tea for two'  File: python.info, Node: Mathematics, Next: Internet Access, Prev: String Pattern Matching, Up: Brief Tour of the Standard Library 2.10.6 Mathematics ------------------ The *note math: b1. module gives access to the underlying C library functions for floating point math: >>> import math >>> math.cos(math.pi / 4) 0.70710678118654757 >>> math.log(1024, 2) 10.0 The *note random: dc. module provides tools for making random selections: >>> import random >>> random.choice(['apple', 'pear', 'banana']) 'apple' >>> random.sample(range(100), 10) # sampling without replacement [30, 83, 16, 4, 8, 81, 41, 50, 18, 33] >>> random.random() # random float 0.17970987693706186 >>> random.randrange(6) # random integer chosen from range(6) 4 The *note statistics: f5. module calculates basic statistical properties (the mean, median, variance, etc.) of numeric data: >>> import statistics >>> data = [2.75, 1.75, 1.25, 0.25, 0.5, 1.25, 3.5] >>> statistics.mean(data) 1.6071428571428572 >>> statistics.median(data) 1.25 >>> statistics.variance(data) 1.3720238095238095 The SciPy project <‘https://scipy.org’> has many other modules for numerical computations.  File: python.info, Node: Internet Access, Next: Dates and Times, Prev: Mathematics, Up: Brief Tour of the Standard Library 2.10.7 Internet Access ---------------------- There are a number of modules for accessing the internet and processing internet protocols. Two of the simplest are *note urllib.request: 120. for retrieving data from URLs and *note smtplib: ed. for sending mail: >>> from urllib.request import urlopen >>> with urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl') as response: ... for line in response: ... line = line.decode('utf-8') # Decoding the binary data to text. ... if 'EST' in line or 'EDT' in line: # look for Eastern Time ... print(line)
Nov. 25, 09:43:32 PM EST >>> import smtplib >>> server = smtplib.SMTP('localhost') >>> server.sendmail('soothsayer@example.org', 'jcaesar@example.org', ... """To: jcaesar@example.org ... From: soothsayer@example.org ... ... Beware the Ides of March. ... """) >>> server.quit() (Note that the second example needs a mailserver running on localhost.)  File: python.info, Node: Dates and Times, Next: Data Compression, Prev: Internet Access, Up: Brief Tour of the Standard Library 2.10.8 Dates and Times ---------------------- The *note datetime: 31. module supplies classes for manipulating dates and times in both simple and complex ways. While date and time arithmetic is supported, the focus of the implementation is on efficient member extraction for output formatting and manipulation. The module also supports objects that are timezone aware. >>> # dates are easily constructed and formatted >>> from datetime import date >>> now = date.today() >>> now datetime.date(2003, 12, 2) >>> now.strftime("%m-%d-%y. %d %b %Y is a %A on the %d day of %B.") '12-02-03. 02 Dec 2003 is a Tuesday on the 02 day of December.' >>> # dates support calendar arithmetic >>> birthday = date(1964, 7, 31) >>> age = now - birthday >>> age.days 14368  File: python.info, Node: Data Compression, Next: Performance Measurement, Prev: Dates and Times, Up: Brief Tour of the Standard Library 2.10.9 Data Compression ----------------------- Common data archiving and compression formats are directly supported by modules including: *note zlib: 144, *note gzip: 8c, *note bz2: 14, *note lzma: ad, *note zipfile: 142. and *note tarfile: 101. >>> import zlib >>> s = b'witch which has which witches wrist watch' >>> len(s) 41 >>> t = zlib.compress(s) >>> len(t) 37 >>> zlib.decompress(t) b'witch which has which witches wrist watch' >>> zlib.crc32(s) 226805979  File: python.info, Node: Performance Measurement, Next: Quality Control, Prev: Data Compression, Up: Brief Tour of the Standard Library 2.10.10 Performance Measurement ------------------------------- Some Python users develop a deep interest in knowing the relative performance of different approaches to the same problem. Python provides a measurement tool that answers those questions immediately. For example, it may be tempting to use the tuple packing and unpacking feature instead of the traditional approach to swapping arguments. The *note timeit: 10b. module quickly demonstrates a modest performance advantage: >>> from timeit import Timer >>> Timer('t=a; a=b; b=t', 'a=1; b=2').timeit() 0.57535828626024577 >>> Timer('a,b = b,a', 'a=1; b=2').timeit() 0.54962537085770791 In contrast to *note timeit: 10b.’s fine level of granularity, the *note profile: d3. and *note pstats: d4. modules provide tools for identifying time critical sections in larger blocks of code.  File: python.info, Node: Quality Control, Next: Batteries Included, Prev: Performance Measurement, Up: Brief Tour of the Standard Library 2.10.11 Quality Control ----------------------- One approach for developing high quality software is to write tests for each function as it is developed and to run those tests frequently during the development process. The *note doctest: 67. module provides a tool for scanning a module and validating tests embedded in a program’s docstrings. Test construction is as simple as cutting-and-pasting a typical call along with its results into the docstring. This improves the documentation by providing the user with an example and it allows the doctest module to make sure the code remains true to the documentation: def average(values): """Computes the arithmetic mean of a list of numbers. >>> print(average([20, 30, 70])) 40.0 """ return sum(values) / len(values) import doctest doctest.testmod() # automatically validate the embedded tests The *note unittest: 11b. module is not as effortless as the *note doctest: 67. module, but it allows a more comprehensive set of tests to be maintained in a separate file: import unittest class TestStatisticalFunctions(unittest.TestCase): def test_average(self): self.assertEqual(average([20, 30, 70]), 40.0) self.assertEqual(round(average([1, 5, 7]), 1), 4.3) with self.assertRaises(ZeroDivisionError): average([]) with self.assertRaises(TypeError): average(20, 30, 70) unittest.main() # Calling from the command line invokes all tests  File: python.info, Node: Batteries Included, Prev: Quality Control, Up: Brief Tour of the Standard Library 2.10.12 Batteries Included -------------------------- Python has a “batteries included” philosophy. This is best seen through the sophisticated and robust capabilities of its larger packages. For example: * The *note xmlrpc.client: 13f. and *note xmlrpc.server: 140. modules make implementing remote procedure calls into an almost trivial task. Despite the modules names, no direct knowledge or handling of XML is needed. * The *note email: 69. package is a library for managing email messages, including MIME and other RFC 2822(1)-based message documents. Unlike *note smtplib: ed. and *note poplib: d0. which actually send and receive messages, the email package has a complete toolset for building or decoding complex message structures (including attachments) and for implementing internet encoding and header protocols. * The *note json: a4. package provides robust support for parsing this popular data interchange format. The *note csv: 2a. module supports direct reading and writing of files in Comma-Separated Value format, commonly supported by databases and spreadsheets. XML processing is supported by the *note xml.etree.ElementTree: 137, *note xml.dom: 134. and *note xml.sax: 13b. packages. Together, these modules and packages greatly simplify data interchange between Python applications and other tools. * The *note sqlite3: f2. module is a wrapper for the SQLite database library, providing a persistent database that can be updated and accessed using slightly nonstandard SQL syntax. * Internationalization is supported by a number of modules including *note gettext: 89, *note locale: a9, and the *note codecs: 1c. package. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2822.html  File: python.info, Node: Brief Tour of the Standard Library — Part II, Next: Virtual Environments and Packages, Prev: Brief Tour of the Standard Library, Up: The Python Tutorial 2.11 Brief Tour of the Standard Library — Part II ================================================= This second tour covers more advanced modules that support professional programming needs. These modules rarely occur in small scripts. * Menu: * Output Formatting:: * Templating:: * Working with Binary Data Record Layouts:: * Multi-threading: Multi-threading<2>. * Logging:: * Weak References:: * Tools for Working with Lists:: * Decimal Floating Point Arithmetic::  File: python.info, Node: Output Formatting, Next: Templating, Up: Brief Tour of the Standard Library — Part II 2.11.1 Output Formatting ------------------------ The *note reprlib: df. module provides a version of *note repr(): 7cc. customized for abbreviated displays of large or deeply nested containers: >>> import reprlib >>> reprlib.repr(set('supercalifragilisticexpialidocious')) "{'a', 'c', 'd', 'e', 'f', 'g', ...}" The *note pprint: d2. module offers more sophisticated control over printing both built-in and user defined objects in a way that is readable by the interpreter. When the result is longer than one line, the “pretty printer” adds line breaks and indentation to more clearly reveal data structure: >>> import pprint >>> t = [[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta', ... 'yellow'], 'blue']]] ... >>> pprint.pprint(t, width=30) [[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta', 'yellow'], 'blue']]] The *note textwrap: 108. module formats paragraphs of text to fit a given screen width: >>> import textwrap >>> doc = """The wrap() method is just like fill() except that it returns ... a list of strings instead of one big string with newlines to separate ... the wrapped lines.""" ... >>> print(textwrap.fill(doc, width=40)) The wrap() method is just like fill() except that it returns a list of strings instead of one big string with newlines to separate the wrapped lines. The *note locale: a9. module accesses a database of culture specific data formats. The grouping attribute of locale’s format function provides a direct way of formatting numbers with group separators: >>> import locale >>> locale.setlocale(locale.LC_ALL, 'English_United States.1252') 'English_United States.1252' >>> conv = locale.localeconv() # get a mapping of conventions >>> x = 1234567.8 >>> locale.format("%d", x, grouping=True) '1,234,567' >>> locale.format_string("%s%.*f", (conv['currency_symbol'], ... conv['frac_digits'], x), grouping=True) '$1,234,567.80'  File: python.info, Node: Templating, Next: Working with Binary Data Record Layouts, Prev: Output Formatting, Up: Brief Tour of the Standard Library — Part II 2.11.2 Templating ----------------- The *note string: f6. module includes a versatile *note Template: 3eb. class with a simplified syntax suitable for editing by end-users. This allows users to customize their applications without having to alter the application. The format uses placeholder names formed by ‘$’ with valid Python identifiers (alphanumeric characters and underscores). Surrounding the placeholder with braces allows it to be followed by more alphanumeric letters with no intervening spaces. Writing ‘$$’ creates a single escaped ‘$’: >>> from string import Template >>> t = Template('${village}folk send $$10 to $cause.') >>> t.substitute(village='Nottingham', cause='the ditch fund') 'Nottinghamfolk send $10 to the ditch fund.' The *note substitute(): f94. method raises a *note KeyError: 2c7. when a placeholder is not supplied in a dictionary or a keyword argument. For mail-merge style applications, user supplied data may be incomplete and the *note safe_substitute(): f95. method may be more appropriate — it will leave placeholders unchanged if data is missing: >>> t = Template('Return the $item to $owner.') >>> d = dict(item='unladen swallow') >>> t.substitute(d) Traceback (most recent call last): ... KeyError: 'owner' >>> t.safe_substitute(d) 'Return the unladen swallow to $owner.' Template subclasses can specify a custom delimiter. For example, a batch renaming utility for a photo browser may elect to use percent signs for placeholders such as the current date, image sequence number, or file format: >>> import time, os.path >>> photofiles = ['img_1074.jpg', 'img_1076.jpg', 'img_1077.jpg'] >>> class BatchRename(Template): ... delimiter = '%' >>> fmt = input('Enter rename style (%d-date %n-seqnum %f-format): ') Enter rename style (%d-date %n-seqnum %f-format): Ashley_%n%f >>> t = BatchRename(fmt) >>> date = time.strftime('%d%b%y') >>> for i, filename in enumerate(photofiles): ... base, ext = os.path.splitext(filename) ... newname = t.substitute(d=date, n=i, f=ext) ... print('{0} --> {1}'.format(filename, newname)) img_1074.jpg --> Ashley_0.jpg img_1076.jpg --> Ashley_1.jpg img_1077.jpg --> Ashley_2.jpg Another application for templating is separating program logic from the details of multiple output formats. This makes it possible to substitute custom templates for XML files, plain text reports, and HTML web reports.  File: python.info, Node: Working with Binary Data Record Layouts, Next: Multi-threading<2>, Prev: Templating, Up: Brief Tour of the Standard Library — Part II 2.11.3 Working with Binary Data Record Layouts ---------------------------------------------- The *note struct: f8. module provides *note pack(): c0b. and *note unpack(): f98. functions for working with variable length binary record formats. The following example shows how to loop through header information in a ZIP file without using the *note zipfile: 142. module. Pack codes ‘"H"’ and ‘"I"’ represent two and four byte unsigned numbers respectively. The ‘"<"’ indicates that they are standard size and in little-endian byte order: import struct with open('myfile.zip', 'rb') as f: data = f.read() start = 0 for i in range(3): # show the first 3 file headers start += 14 fields = struct.unpack(', Next: Logging, Prev: Working with Binary Data Record Layouts, Up: Brief Tour of the Standard Library — Part II 2.11.4 Multi-threading ---------------------- Threading is a technique for decoupling tasks which are not sequentially dependent. Threads can be used to improve the responsiveness of applications that accept user input while other tasks run in the background. A related use case is running I/O in parallel with computations in another thread. The following code shows how the high level *note threading: 109. module can run tasks in background while the main program continues to run: import threading, zipfile class AsyncZip(threading.Thread): def __init__(self, infile, outfile): threading.Thread.__init__(self) self.infile = infile self.outfile = outfile def run(self): f = zipfile.ZipFile(self.outfile, 'w', zipfile.ZIP_DEFLATED) f.write(self.infile) f.close() print('Finished background zip of:', self.infile) background = AsyncZip('mydata.txt', 'myarchive.zip') background.start() print('The main program continues to run in foreground.') background.join() # Wait for the background task to finish print('Main program waited until background was done.') The principal challenge of multi-threaded applications is coordinating threads that share data or other resources. To that end, the threading module provides a number of synchronization primitives including locks, events, condition variables, and semaphores. While those tools are powerful, minor design errors can result in problems that are difficult to reproduce. So, the preferred approach to task coordination is to concentrate all access to a resource in a single thread and then use the *note queue: da. module to feed that thread with requests from other threads. Applications using *note Queue: d18. objects for inter-thread communication and coordination are easier to design, more readable, and more reliable.  File: python.info, Node: Logging, Next: Weak References, Prev: Multi-threading<2>, Up: Brief Tour of the Standard Library — Part II 2.11.5 Logging -------------- The *note logging: aa. module offers a full featured and flexible logging system. At its simplest, log messages are sent to a file or to ‘sys.stderr’: import logging logging.debug('Debugging information') logging.info('Informational message') logging.warning('Warning:config file %s not found', 'server.conf') logging.error('Error occurred') logging.critical('Critical error -- shutting down') This produces the following output: WARNING:root:Warning:config file server.conf not found ERROR:root:Error occurred CRITICAL:root:Critical error -- shutting down By default, informational and debugging messages are suppressed and the output is sent to standard error. Other output options include routing messages through email, datagrams, sockets, or to an HTTP Server. New filters can select different routing based on message priority: ‘DEBUG’, ‘INFO’, ‘WARNING’, ‘ERROR’, and ‘CRITICAL’. The logging system can be configured directly from Python or can be loaded from a user editable configuration file for customized logging without altering the application.  File: python.info, Node: Weak References, Next: Tools for Working with Lists, Prev: Logging, Up: Brief Tour of the Standard Library — Part II 2.11.6 Weak References ---------------------- Python does automatic memory management (reference counting for most objects and *note garbage collection: f9f. to eliminate cycles). The memory is freed shortly after the last reference to it has been eliminated. This approach works fine for most applications but occasionally there is a need to track objects only as long as they are being used by something else. Unfortunately, just tracking them creates a reference that makes them permanent. The *note weakref: 128. module provides tools for tracking objects without creating a reference. When the object is no longer needed, it is automatically removed from a weakref table and a callback is triggered for weakref objects. Typical applications include caching objects that are expensive to create: >>> import weakref, gc >>> class A: ... def __init__(self, value): ... self.value = value ... def __repr__(self): ... return str(self.value) ... >>> a = A(10) # create a reference >>> d = weakref.WeakValueDictionary() >>> d['primary'] = a # does not create a reference >>> d['primary'] # fetch the object if it is still alive 10 >>> del a # remove the one reference >>> gc.collect() # run garbage collection right away 0 >>> d['primary'] # entry was automatically removed Traceback (most recent call last): File "", line 1, in d['primary'] # entry was automatically removed File "C:/python38/lib/weakref.py", line 46, in __getitem__ o = self.data[key]() KeyError: 'primary'  File: python.info, Node: Tools for Working with Lists, Next: Decimal Floating Point Arithmetic, Prev: Weak References, Up: Brief Tour of the Standard Library — Part II 2.11.7 Tools for Working with Lists ----------------------------------- Many data structure needs can be met with the built-in list type. However, sometimes there is a need for alternative implementations with different performance trade-offs. The *note array: 7. module provides an *note array(): 451. object that is like a list that stores only homogeneous data and stores it more compactly. The following example shows an array of numbers stored as two byte unsigned binary numbers (typecode ‘"H"’) rather than the usual 16 bytes per entry for regular lists of Python int objects: >>> from array import array >>> a = array('H', [4000, 10, 700, 22222]) >>> sum(a) 26932 >>> a[1:3] array('H', [10, 700]) The *note collections: 1e. module provides a *note deque(): 531. object that is like a list with faster appends and pops from the left side but slower lookups in the middle. These objects are well suited for implementing queues and breadth first tree searches: >>> from collections import deque >>> d = deque(["task1", "task2", "task3"]) >>> d.append("task4") >>> print("Handling", d.popleft()) Handling task1 unsearched = deque([starting_node]) def breadth_first_search(unsearched): node = unsearched.popleft() for m in gen_moves(node): if is_goal(m): return m unsearched.append(m) In addition to alternative list implementations, the library also offers other tools such as the *note bisect: 12. module with functions for manipulating sorted lists: >>> import bisect >>> scores = [(100, 'perl'), (200, 'tcl'), (400, 'lua'), (500, 'python')] >>> bisect.insort(scores, (300, 'ruby')) >>> scores [(100, 'perl'), (200, 'tcl'), (300, 'ruby'), (400, 'lua'), (500, 'python')] The *note heapq: 8e. module provides functions for implementing heaps based on regular lists. The lowest valued entry is always kept at position zero. This is useful for applications which repeatedly access the smallest element but do not want to run a full list sort: >>> from heapq import heapify, heappop, heappush >>> data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0] >>> heapify(data) # rearrange the list into heap order >>> heappush(data, -5) # add a new entry >>> [heappop(data) for i in range(3)] # fetch the three smallest entries [-5, 0, 1]  File: python.info, Node: Decimal Floating Point Arithmetic, Prev: Tools for Working with Lists, Up: Brief Tour of the Standard Library — Part II 2.11.8 Decimal Floating Point Arithmetic ---------------------------------------- The *note decimal: 36. module offers a *note Decimal: 188. datatype for decimal floating point arithmetic. Compared to the built-in *note float: 187. implementation of binary floating point, the class is especially helpful for * financial applications and other uses which require exact decimal representation, * control over precision, * control over rounding to meet legal or regulatory requirements, * tracking of significant decimal places, or * applications where the user expects the results to match calculations done by hand. For example, calculating a 5% tax on a 70 cent phone charge gives different results in decimal floating point and binary floating point. The difference becomes significant if the results are rounded to the nearest cent: >>> from decimal import * >>> round(Decimal('0.70') * Decimal('1.05'), 2) Decimal('0.74') >>> round(.70 * 1.05, 2) 0.73 The *note Decimal: 188. result keeps a trailing zero, automatically inferring four place significance from multiplicands with two place significance. Decimal reproduces mathematics as done by hand and avoids issues that can arise when binary floating point cannot exactly represent decimal quantities. Exact representation enables the *note Decimal: 188. class to perform modulo calculations and equality tests that are unsuitable for binary floating point: >>> Decimal('1.00') % Decimal('.10') Decimal('0.00') >>> 1.00 % 0.10 0.09999999999999995 >>> sum([Decimal('0.1')]*10) == Decimal('1.0') True >>> sum([0.1]*10) == 1.0 False The *note decimal: 36. module provides arithmetic with as much precision as needed: >>> getcontext().prec = 36 >>> Decimal(1) / Decimal(7) Decimal('0.142857142857142857142857142857142857')  File: python.info, Node: Virtual Environments and Packages, Next: What Now?, Prev: Brief Tour of the Standard Library — Part II, Up: The Python Tutorial 2.12 Virtual Environments and Packages ====================================== * Menu: * Introduction: Introduction<4>. * Creating Virtual Environments:: * Managing Packages with pip::  File: python.info, Node: Introduction<4>, Next: Creating Virtual Environments, Up: Virtual Environments and Packages 2.12.1 Introduction ------------------- Python applications will often use packages and modules that don’t come as part of the standard library. Applications will sometimes need a specific version of a library, because the application may require that a particular bug has been fixed or the application may be written using an obsolete version of the library’s interface. This means it may not be possible for one Python installation to meet the requirements of every application. If application A needs version 1.0 of a particular module but application B needs version 2.0, then the requirements are in conflict and installing either version 1.0 or 2.0 will leave one application unable to run. The solution for this problem is to create a *note virtual environment: fa8, a self-contained directory tree that contains a Python installation for a particular version of Python, plus a number of additional packages. Different applications can then use different virtual environments. To resolve the earlier example of conflicting requirements, application A can have its own virtual environment with version 1.0 installed while application B has another virtual environment with version 2.0. If application B requires a library be upgraded to version 3.0, this will not affect application A’s environment.  File: python.info, Node: Creating Virtual Environments, Next: Managing Packages with pip, Prev: Introduction<4>, Up: Virtual Environments and Packages 2.12.2 Creating Virtual Environments ------------------------------------ The module used to create and manage virtual environments is called *note venv: 125. *note venv: 125. will usually install the most recent version of Python that you have available. If you have multiple versions of Python on your system, you can select a specific Python version by running ‘python3’ or whichever version you want. To create a virtual environment, decide upon a directory where you want to place it, and run the *note venv: 125. module as a script with the directory path: python3 -m venv tutorial-env This will create the ‘tutorial-env’ directory if it doesn’t exist, and also create directories inside it containing a copy of the Python interpreter, the standard library, and various supporting files. A common directory location for a virtual environment is ‘.venv’. This name keeps the directory typically hidden in your shell and thus out of the way while giving it a name that explains why the directory exists. It also prevents clashing with ‘.env’ environment variable definition files that some tooling supports. Once you’ve created a virtual environment, you may activate it. On Windows, run: tutorial-env\Scripts\activate.bat On Unix or MacOS, run: source tutorial-env/bin/activate (This script is written for the bash shell. If you use the ‘csh’ or ‘fish’ shells, there are alternate ‘activate.csh’ and ‘activate.fish’ scripts you should use instead.) Activating the virtual environment will change your shell’s prompt to show what virtual environment you’re using, and modify the environment so that running ‘python’ will get you that particular version and installation of Python. For example: $ source ~/envs/tutorial-env/bin/activate (tutorial-env) $ python Python 3.5.1 (default, May 6 2016, 10:59:36) ... >>> import sys >>> sys.path ['', '/usr/local/lib/python35.zip', ..., '~/envs/tutorial-env/lib/python3.5/site-packages'] >>>  File: python.info, Node: Managing Packages with pip, Prev: Creating Virtual Environments, Up: Virtual Environments and Packages 2.12.3 Managing Packages with pip --------------------------------- You can install, upgrade, and remove packages using a program called ‘pip’. By default ‘pip’ will install packages from the Python Package Index, <‘https://pypi.org’>. You can browse the Python Package Index by going to it in your web browser, or you can use ‘pip’’s limited search feature: (tutorial-env) $ pip search astronomy skyfield - Elegant astronomy for Python gary - Galactic astronomy and gravitational dynamics. novas - The United States Naval Observatory NOVAS astronomy library astroobs - Provides astronomy ephemeris to plan telescope observations PyAstronomy - A collection of astronomy related tools for Python. ... ‘pip’ has a number of subcommands: “search”, “install”, “uninstall”, “freeze”, etc. (Consult the *note Installing Python Modules: 7f5. guide for complete documentation for ‘pip’.) You can install the latest version of a package by specifying a package’s name: (tutorial-env) $ pip install novas Collecting novas Downloading novas-3.1.1.3.tar.gz (136kB) Installing collected packages: novas Running setup.py install for novas Successfully installed novas-3.1.1.3 You can also install a specific version of a package by giving the package name followed by ‘==’ and the version number: (tutorial-env) $ pip install requests==2.6.0 Collecting requests==2.6.0 Using cached requests-2.6.0-py2.py3-none-any.whl Installing collected packages: requests Successfully installed requests-2.6.0 If you re-run this command, ‘pip’ will notice that the requested version is already installed and do nothing. You can supply a different version number to get that version, or you can run ‘pip install --upgrade’ to upgrade the package to the latest version: (tutorial-env) $ pip install --upgrade requests Collecting requests Installing collected packages: requests Found existing installation: requests 2.6.0 Uninstalling requests-2.6.0: Successfully uninstalled requests-2.6.0 Successfully installed requests-2.7.0 ‘pip uninstall’ followed by one or more package names will remove the packages from the virtual environment. ‘pip show’ will display information about a particular package: (tutorial-env) $ pip show requests --- Metadata-Version: 2.0 Name: requests Version: 2.7.0 Summary: Python HTTP for Humans. Home-page: http://python-requests.org Author: Kenneth Reitz Author-email: me@kennethreitz.com License: Apache 2.0 Location: /Users/akuchling/envs/tutorial-env/lib/python3.4/site-packages Requires: ‘pip list’ will display all of the packages installed in the virtual environment: (tutorial-env) $ pip list novas (3.1.1.3) numpy (1.9.2) pip (7.0.3) requests (2.7.0) setuptools (16.0) ‘pip freeze’ will produce a similar list of the installed packages, but the output uses the format that ‘pip install’ expects. A common convention is to put this list in a ‘requirements.txt’ file: (tutorial-env) $ pip freeze > requirements.txt (tutorial-env) $ cat requirements.txt novas==3.1.1.3 numpy==1.9.2 requests==2.7.0 The ‘requirements.txt’ can then be committed to version control and shipped as part of an application. Users can then install all the necessary packages with ‘install -r’: (tutorial-env) $ pip install -r requirements.txt Collecting novas==3.1.1.3 (from -r requirements.txt (line 1)) ... Collecting numpy==1.9.2 (from -r requirements.txt (line 2)) ... Collecting requests==2.7.0 (from -r requirements.txt (line 3)) ... Installing collected packages: novas, numpy, requests Running setup.py install for novas Successfully installed novas-3.1.1.3 numpy-1.9.2 requests-2.7.0 ‘pip’ has many more options. Consult the *note Installing Python Modules: 7f5. guide for complete documentation for ‘pip’. When you’ve written a package and want to make it available on the Python Package Index, consult the *note Distributing Python Modules: 7f6. guide.  File: python.info, Node: What Now?, Next: Interactive Input Editing and History Substitution, Prev: Virtual Environments and Packages, Up: The Python Tutorial 2.13 What Now? ============== Reading this tutorial has probably reinforced your interest in using Python — you should be eager to apply Python to solving your real-world problems. Where should you go to learn more? This tutorial is part of Python’s documentation set. Some other documents in the set are: * *note The Python Standard Library: e8e.: You should browse through this manual, which gives complete (though terse) reference material about types, functions, and the modules in the standard library. The standard Python distribution includes a `lot' of additional code. There are modules to read Unix mailboxes, retrieve documents via HTTP, generate random numbers, parse command-line options, write CGI programs, compress data, and many other tasks. Skimming through the Library Reference will give you an idea of what’s available. * *note Installing Python Modules: 7f5. explains how to install additional modules written by other Python users. * *note The Python Language Reference: e8f.: A detailed explanation of Python’s syntax and semantics. It’s heavy reading, but is useful as a complete guide to the language itself. More Python resources: * ‘https://www.python.org’: The major Python Web site. It contains code, documentation, and pointers to Python-related pages around the Web. This Web site is mirrored in various places around the world, such as Europe, Japan, and Australia; a mirror may be faster than the main site, depending on your geographical location. * ‘https://docs.python.org’: Fast access to Python’s documentation. * ‘https://pypi.org’: The Python Package Index, previously also nicknamed the Cheese Shop (1), is an index of user-created Python modules that are available for download. Once you begin releasing code, you can register it here so that others can find it. * ‘https://code.activestate.com/recipes/langs/python/’: The Python Cookbook is a sizable collection of code examples, larger modules, and useful scripts. Particularly notable contributions are collected in a book also titled Python Cookbook (O’Reilly & Associates, ISBN 0-596-00797-3.) * ‘http://www.pyvideo.org’ collects links to Python-related videos from conferences and user-group meetings. * ‘https://scipy.org’: The Scientific Python project includes modules for fast array computations and manipulations plus a host of packages for such things as linear algebra, Fourier transforms, non-linear solvers, random number distributions, statistical analysis and the like. For Python-related questions and problem reports, you can post to the newsgroup ‘comp.lang.python’, or send them to the mailing list at . The newsgroup and mailing list are gatewayed, so messages posted to one will automatically be forwarded to the other. There are hundreds of postings a day, asking (and answering) questions, suggesting new features, and announcing new modules. Mailing list archives are available at ‘https://mail.python.org/pipermail/’. Before posting, be sure to check the list of *note Frequently Asked Questions: fae. (also called the FAQ). The FAQ answers many of the questions that come up again and again, and may already contain the solution for your problem. ---------- Footnotes ---------- (1) (1) “Cheese Shop” is a Monty Python’s sketch: a customer enters a cheese shop, but whatever cheese he asks for, the clerk says it’s missing.  File: python.info, Node: Interactive Input Editing and History Substitution, Next: Floating Point Arithmetic Issues and Limitations, Prev: What Now?, Up: The Python Tutorial 2.14 Interactive Input Editing and History Substitution ======================================================= Some versions of the Python interpreter support editing of the current input line and history substitution, similar to facilities found in the Korn shell and the GNU Bash shell. This is implemented using the GNU Readline(1) library, which supports various styles of editing. This library has its own documentation which we won’t duplicate here. * Menu: * Tab Completion and History Editing:: * Alternatives to the Interactive Interpreter:: ---------- Footnotes ---------- (1) https://tiswww.case.edu/php/chet/readline/rltop.html  File: python.info, Node: Tab Completion and History Editing, Next: Alternatives to the Interactive Interpreter, Up: Interactive Input Editing and History Substitution 2.14.1 Tab Completion and History Editing ----------------------------------------- Completion of variable and module names is *note automatically enabled: 8e6. at interpreter startup so that the ‘Tab’ key invokes the completion function; it looks at Python statement names, the current local variables, and the available module names. For dotted expressions such as ‘string.a’, it will evaluate the expression up to the final ‘'.'’ and then suggest completions from the attributes of the resulting object. Note that this may execute application-defined code if an object with a *note __getattr__(): 31a. method is part of the expression. The default configuration also saves your history into a file named ‘.python_history’ in your user directory. The history will be available again during the next interactive interpreter session.  File: python.info, Node: Alternatives to the Interactive Interpreter, Prev: Tab Completion and History Editing, Up: Interactive Input Editing and History Substitution 2.14.2 Alternatives to the Interactive Interpreter -------------------------------------------------- This facility is an enormous step forward compared to earlier versions of the interpreter; however, some wishes are left: It would be nice if the proper indentation were suggested on continuation lines (the parser knows if an indent token is required next). The completion mechanism might use the interpreter’s symbol table. A command to check (or even suggest) matching parentheses, quotes, etc., would also be useful. One alternative enhanced interactive interpreter that has been around for quite some time is IPython(1), which features tab completion, object exploration and advanced history management. It can also be thoroughly customized and embedded into other applications. Another similar enhanced interactive environment is bpython(2). ---------- Footnotes ---------- (1) https://ipython.org/ (2) https://www.bpython-interpreter.org/  File: python.info, Node: Floating Point Arithmetic Issues and Limitations, Next: Appendix, Prev: Interactive Input Editing and History Substitution, Up: The Python Tutorial 2.15 Floating Point Arithmetic: Issues and Limitations ====================================================== Floating-point numbers are represented in computer hardware as base 2 (binary) fractions. For example, the decimal fraction 0.125 has value 1/10 + 2/100 + 5/1000, and in the same way the binary fraction 0.001 has value 0/2 + 0/4 + 1/8. These two fractions have identical values, the only real difference being that the first is written in base 10 fractional notation, and the second in base 2. Unfortunately, most decimal fractions cannot be represented exactly as binary fractions. A consequence is that, in general, the decimal floating-point numbers you enter are only approximated by the binary floating-point numbers actually stored in the machine. The problem is easier to understand at first in base 10. Consider the fraction 1/3. You can approximate that as a base 10 fraction: 0.3 or, better, 0.33 or, better, 0.333 and so on. No matter how many digits you’re willing to write down, the result will never be exactly 1/3, but will be an increasingly better approximation of 1/3. In the same way, no matter how many base 2 digits you’re willing to use, the decimal value 0.1 cannot be represented exactly as a base 2 fraction. In base 2, 1/10 is the infinitely repeating fraction 0.0001100110011001100110011001100110011001100110011... Stop at any finite number of bits, and you get an approximation. On most machines today, floats are approximated using a binary fraction with the numerator using the first 53 bits starting with the most significant bit and with the denominator as a power of two. In the case of 1/10, the binary fraction is ‘3602879701896397 / 2 ** 55’ which is close to but not exactly equal to the true value of 1/10. Many users are not aware of the approximation because of the way values are displayed. Python only prints a decimal approximation to the true decimal value of the binary approximation stored by the machine. On most machines, if Python were to print the true decimal value of the binary approximation stored for 0.1, it would have to display >>> 0.1 0.1000000000000000055511151231257827021181583404541015625 That is more digits than most people find useful, so Python keeps the number of digits manageable by displaying a rounded value instead >>> 1 / 10 0.1 Just remember, even though the printed result looks like the exact value of 1/10, the actual stored value is the nearest representable binary fraction. Interestingly, there are many different decimal numbers that share the same nearest approximate binary fraction. For example, the numbers ‘0.1’ and ‘0.10000000000000001’ and ‘0.1000000000000000055511151231257827021181583404541015625’ are all approximated by ‘3602879701896397 / 2 ** 55’. Since all of these decimal values share the same approximation, any one of them could be displayed while still preserving the invariant ‘eval(repr(x)) == x’. Historically, the Python prompt and built-in *note repr(): 7cc. function would choose the one with 17 significant digits, ‘0.10000000000000001’. Starting with Python 3.1, Python (on most systems) is now able to choose the shortest of these and simply display ‘0.1’. Note that this is in the very nature of binary floating-point: this is not a bug in Python, and it is not a bug in your code either. You’ll see the same kind of thing in all languages that support your hardware’s floating-point arithmetic (although some languages may not `display' the difference by default, or in all output modes). For more pleasant output, you may wish to use string formatting to produce a limited number of significant digits: >>> format(math.pi, '.12g') # give 12 significant digits '3.14159265359' >>> format(math.pi, '.2f') # give 2 digits after the point '3.14' >>> repr(math.pi) '3.141592653589793' It’s important to realize that this is, in a real sense, an illusion: you’re simply rounding the `display' of the true machine value. One illusion may beget another. For example, since 0.1 is not exactly 1/10, summing three values of 0.1 may not yield exactly 0.3, either: >>> .1 + .1 + .1 == .3 False Also, since the 0.1 cannot get any closer to the exact value of 1/10 and 0.3 cannot get any closer to the exact value of 3/10, then pre-rounding with *note round(): c6d. function cannot help: >>> round(.1, 1) + round(.1, 1) + round(.1, 1) == round(.3, 1) False Though the numbers cannot be made closer to their intended exact values, the *note round(): c6d. function can be useful for post-rounding so that results with inexact values become comparable to one another: >>> round(.1 + .1 + .1, 10) == round(.3, 10) True Binary floating-point arithmetic holds many surprises like this. The problem with “0.1” is explained in precise detail below, in the “Representation Error” section. See The Perils of Floating Point(1) for a more complete account of other common surprises. As that says near the end, “there are no easy answers.” Still, don’t be unduly wary of floating-point! The errors in Python float operations are inherited from the floating-point hardware, and on most machines are on the order of no more than 1 part in 2**53 per operation. That’s more than adequate for most tasks, but you do need to keep in mind that it’s not decimal arithmetic and that every float operation can suffer a new rounding error. While pathological cases do exist, for most casual use of floating-point arithmetic you’ll see the result you expect in the end if you simply round the display of your final results to the number of decimal digits you expect. *note str(): 330. usually suffices, and for finer control see the *note str.format(): 4da. method’s format specifiers in *note Format String Syntax: d1a. For use cases which require exact decimal representation, try using the *note decimal: 36. module which implements decimal arithmetic suitable for accounting applications and high-precision applications. Another form of exact arithmetic is supported by the *note fractions: 83. module which implements arithmetic based on rational numbers (so the numbers like 1/3 can be represented exactly). If you are a heavy user of floating point operations you should take a look at the Numerical Python package and many other packages for mathematical and statistical operations supplied by the SciPy project. See <‘https://scipy.org’>. Python provides tools that may help on those rare occasions when you really `do' want to know the exact value of a float. The *note float.as_integer_ratio(): fb9. method expresses the value of a float as a fraction: >>> x = 3.14159 >>> x.as_integer_ratio() (3537115888337719, 1125899906842624) Since the ratio is exact, it can be used to losslessly recreate the original value: >>> x == 3537115888337719 / 1125899906842624 True The *note float.hex(): fba. method expresses a float in hexadecimal (base 16), again giving the exact value stored by your computer: >>> x.hex() '0x1.921f9f01b866ep+1' This precise hexadecimal representation can be used to reconstruct the float value exactly: >>> x == float.fromhex('0x1.921f9f01b866ep+1') True Since the representation is exact, it is useful for reliably porting values across different versions of Python (platform independence) and exchanging data with other languages that support the same format (such as Java and C99). Another helpful tool is the *note math.fsum(): d3e. function which helps mitigate loss-of-precision during summation. It tracks “lost digits” as values are added onto a running total. That can make a difference in overall accuracy so that the errors do not accumulate to the point where they affect the final total: >>> sum([0.1] * 10) == 1.0 False >>> math.fsum([0.1] * 10) == 1.0 True * Menu: * Representation Error:: ---------- Footnotes ---------- (1) http://www.lahey.com/float.htm  File: python.info, Node: Representation Error, Up: Floating Point Arithmetic Issues and Limitations 2.15.1 Representation Error --------------------------- This section explains the “0.1” example in detail, and shows how you can perform an exact analysis of cases like this yourself. Basic familiarity with binary floating-point representation is assumed. `Representation error' refers to the fact that some (most, actually) decimal fractions cannot be represented exactly as binary (base 2) fractions. This is the chief reason why Python (or Perl, C, C++, Java, Fortran, and many others) often won’t display the exact decimal number you expect. Why is that? 1/10 is not exactly representable as a binary fraction. Almost all machines today (November 2000) use IEEE-754 floating point arithmetic, and almost all platforms map Python floats to IEEE-754 “double precision”. 754 doubles contain 53 bits of precision, so on input the computer strives to convert 0.1 to the closest fraction it can of the form `J'/2**`N' where `J' is an integer containing exactly 53 bits. Rewriting 1 / 10 ~= J / (2**N) as J ~= 2**N / 10 and recalling that `J' has exactly 53 bits (is ‘>= 2**52’ but ‘< 2**53’), the best value for `N' is 56: >>> 2**52 <= 2**56 // 10 < 2**53 True That is, 56 is the only value for `N' that leaves `J' with exactly 53 bits. The best possible value for `J' is then that quotient rounded: >>> q, r = divmod(2**56, 10) >>> r 6 Since the remainder is more than half of 10, the best approximation is obtained by rounding up: >>> q+1 7205759403792794 Therefore the best possible approximation to 1/10 in 754 double precision is: 7205759403792794 / 2 ** 56 Dividing both the numerator and denominator by two reduces the fraction to: 3602879701896397 / 2 ** 55 Note that since we rounded up, this is actually a little bit larger than 1/10; if we had not rounded up, the quotient would have been a little bit smaller than 1/10. But in no case can it be `exactly' 1/10! So the computer never “sees” 1/10: what it sees is the exact fraction given above, the best 754 double approximation it can get: >>> 0.1 * 2 ** 55 3602879701896397.0 If we multiply that fraction by 10**55, we can see the value out to 55 decimal digits: >>> 3602879701896397 * 10 ** 55 // 2 ** 55 1000000000000000055511151231257827021181583404541015625 meaning that the exact number stored in the computer is equal to the decimal value 0.1000000000000000055511151231257827021181583404541015625. Instead of displaying the full decimal value, many languages (including older versions of Python), round the result to 17 significant digits: >>> format(0.1, '.17f') '0.10000000000000001' The *note fractions: 83. and *note decimal: 36. modules make these calculations easy: >>> from decimal import Decimal >>> from fractions import Fraction >>> Fraction.from_float(0.1) Fraction(3602879701896397, 36028797018963968) >>> (0.1).as_integer_ratio() (3602879701896397, 36028797018963968) >>> Decimal.from_float(0.1) Decimal('0.1000000000000000055511151231257827021181583404541015625') >>> format(Decimal.from_float(0.1), '.17') '0.10000000000000001'  File: python.info, Node: Appendix, Prev: Floating Point Arithmetic Issues and Limitations, Up: The Python Tutorial 2.16 Appendix ============= * Menu: * Interactive Mode: Interactive Mode<2>.  File: python.info, Node: Interactive Mode<2>, Up: Appendix 2.16.1 Interactive Mode ----------------------- * Menu: * Error Handling:: * Executable Python Scripts:: * The Interactive Startup File:: * The Customization Modules::  File: python.info, Node: Error Handling, Next: Executable Python Scripts, Up: Interactive Mode<2> 2.16.1.1 Error Handling ....................... When an error occurs, the interpreter prints an error message and a stack trace. In interactive mode, it then returns to the primary prompt; when input came from a file, it exits with a nonzero exit status after printing the stack trace. (Exceptions handled by an *note except: b3e. clause in a *note try: d72. statement are not errors in this context.) Some errors are unconditionally fatal and cause an exit with a nonzero exit; this applies to internal inconsistencies and some cases of running out of memory. All error messages are written to the standard error stream; normal output from executed commands is written to standard output. Typing the interrupt character (usually ‘Control-C’ or ‘Delete’) to the primary or secondary prompt cancels the input and returns to the primary prompt. (1) Typing an interrupt while a command is executing raises the *note KeyboardInterrupt: 197. exception, which may be handled by a *note try: d72. statement. ---------- Footnotes ---------- (1) (1) A problem with the GNU Readline package may prevent this.  File: python.info, Node: Executable Python Scripts, Next: The Interactive Startup File, Prev: Error Handling, Up: Interactive Mode<2> 2.16.1.2 Executable Python Scripts .................................. On BSD’ish Unix systems, Python scripts can be made directly executable, like shell scripts, by putting the line #!/usr/bin/env python3.5 (assuming that the interpreter is on the user’s ‘PATH’) at the beginning of the script and giving the file an executable mode. The ‘#!’ must be the first two characters of the file. On some platforms, this first line must end with a Unix-style line ending (‘'\n'’), not a Windows (‘'\r\n'’) line ending. Note that the hash, or pound, character, ‘'#'’, is used to start a comment in Python. The script can be given an executable mode, or permission, using the ‘chmod’ command. $ chmod +x myscript.py On Windows systems, there is no notion of an “executable mode”. The Python installer automatically associates ‘.py’ files with ‘python.exe’ so that a double-click on a Python file will run it as a script. The extension can also be ‘.pyw’, in that case, the console window that normally appears is suppressed.  File: python.info, Node: The Interactive Startup File, Next: The Customization Modules, Prev: Executable Python Scripts, Up: Interactive Mode<2> 2.16.1.3 The Interactive Startup File ..................................... When you use Python interactively, it is frequently handy to have some standard commands executed every time the interpreter is started. You can do this by setting an environment variable named *note PYTHONSTARTUP: 8e5. to the name of a file containing your start-up commands. This is similar to the ‘.profile’ feature of the Unix shells. This file is only read in interactive sessions, not when Python reads commands from a script, and not when ‘/dev/tty’ is given as the explicit source of commands (which otherwise behaves like an interactive session). It is executed in the same namespace where interactive commands are executed, so that objects that it defines or imports can be used without qualification in the interactive session. You can also change the prompts ‘sys.ps1’ and ‘sys.ps2’ in this file. If you want to read an additional start-up file from the current directory, you can program this in the global start-up file using code like ‘if os.path.isfile('.pythonrc.py'): exec(open('.pythonrc.py').read())’. If you want to use the startup file in a script, you must do this explicitly in the script: import os filename = os.environ.get('PYTHONSTARTUP') if filename and os.path.isfile(filename): with open(filename) as fobj: startup_file = fobj.read() exec(startup_file)  File: python.info, Node: The Customization Modules, Prev: The Interactive Startup File, Up: Interactive Mode<2> 2.16.1.4 The Customization Modules .................................. Python provides two hooks to let you customize it: ‘sitecustomize’ and ‘usercustomize’. To see how it works, you need first to find the location of your user site-packages directory. Start Python and run this code: >>> import site >>> site.getusersitepackages() '/home/user/.local/lib/python3.5/site-packages' Now you can create a file named ‘usercustomize.py’ in that directory and put anything you want in it. It will affect every invocation of Python, unless it is started with the *note -s: d15. option to disable the automatic import. ‘sitecustomize’ works in the same way, but is typically created by an administrator of the computer in the global site-packages directory, and is imported before ‘usercustomize’. See the documentation of the *note site: eb. module for more details.  File: python.info, Node: Python Setup and Usage, Next: The Python Language Reference, Prev: The Python Tutorial, Up: Top 3 Python Setup and Usage ************************ This part of the documentation is devoted to general information on the setup of the Python environment on different platforms, the invocation of the interpreter and things that make working with Python easier. * Menu: * Command line and environment:: * Using Python on Unix platforms:: * Using Python on Windows:: * Using Python on a Macintosh:: * Editors and IDEs::  File: python.info, Node: Command line and environment, Next: Using Python on Unix platforms, Up: Python Setup and Usage 3.1 Command line and environment ================================ The CPython interpreter scans the command line and the environment for various settings. `CPython implementation detail:' Other implementations’ command line schemes may differ. See *note Alternate Implementations: fcd. for further resources. * Menu: * Command line:: * Environment variables::  File: python.info, Node: Command line, Next: Environment variables, Up: Command line and environment 3.1.1 Command line ------------------ When invoking Python, you may specify any of these options: python [-bBdEhiIOqsSuvVWx?] [-c command | -m module-name | script | - ] [args] The most common use case is, of course, a simple invocation of a script: python myscript.py * Menu: * Interface options:: * Generic options:: * Miscellaneous options:: * Options you shouldn’t use::  File: python.info, Node: Interface options, Next: Generic options, Up: Command line 3.1.1.1 Interface options ......................... The interpreter interface resembles that of the UNIX shell, but provides some additional methods of invocation: * When called with standard input connected to a tty device, it prompts for commands and executes them until an EOF (an end-of-file character, you can produce that with ‘Ctrl-D’ on UNIX or ‘Ctrl-Z, Enter’ on Windows) is read. * When called with a file name argument or with a file as standard input, it reads and executes a script from that file. * When called with a directory name argument, it reads and executes an appropriately named script from that directory. * When called with ‘-c command’, it executes the Python statement(s) given as `command'. Here `command' may contain multiple statements separated by newlines. Leading whitespace is significant in Python statements! * When called with ‘-m module-name’, the given module is located on the Python module path and executed as a script. In non-interactive mode, the entire input is parsed before it is executed. An interface option terminates the list of options consumed by the interpreter, all consecutive arguments will end up in *note sys.argv: bfb. – note that the first element, subscript zero (‘sys.argv[0]’), is a string reflecting the program’s source. -- Program Option: -c Execute the Python code in `command'. `command' can be one or more statements separated by newlines, with significant leading whitespace as in normal module code. If this option is given, the first element of *note sys.argv: bfb. will be ‘"-c"’ and the current directory will be added to the start of *note sys.path: 488. (allowing modules in that directory to be imported as top level modules). Raises an *note auditing event: fd1. ‘cpython.run_command’ with argument ‘command’. -- Program Option: -m Search *note sys.path: 488. for the named module and execute its contents as the *note __main__: 1. module. Since the argument is a `module' name, you must not give a file extension (‘.py’). The module name should be a valid absolute Python module name, but the implementation may not always enforce this (e.g. it may allow you to use a name that includes a hyphen). Package names (including namespace packages) are also permitted. When a package name is supplied instead of a normal module, the interpreter will execute ‘.__main__’ as the main module. This behaviour is deliberately similar to the handling of directories and zipfiles that are passed to the interpreter as the script argument. Note: This option cannot be used with built-in modules and extension modules written in C, since they do not have Python module files. However, it can still be used for precompiled modules, even if the original source file is not available. If this option is given, the first element of *note sys.argv: bfb. will be the full path to the module file (while the module file is being located, the first element will be set to ‘"-m"’). As with the *note -c: e9e. option, the current directory will be added to the start of *note sys.path: 488. *note -I: fd2. option can be used to run the script in isolated mode where *note sys.path: 488. contains neither the current directory nor the user’s site-packages directory. All ‘PYTHON*’ environment variables are ignored, too. Many standard library modules contain code that is invoked on their execution as a script. An example is the *note timeit: 10b. module: python -m timeit -s 'setup here' 'benchmarked code here' python -m timeit -h # for details Raises an *note auditing event: fd1. ‘cpython.run_module’ with argument ‘module-name’. See also ........ *note runpy.run_module(): fd3. Equivalent functionality directly available to Python code PEP 338(1) – Executing modules as scripts Changed in version 3.1: Supply the package name to run a ‘__main__’ submodule. Changed in version 3.4: namespace packages are also supported -- Describe: - Read commands from standard input (*note sys.stdin: 30d.). If standard input is a terminal, *note -i: e1f. is implied. If this option is given, the first element of *note sys.argv: bfb. will be ‘"-"’ and the current directory will be added to the start of *note sys.path: 488. Raises an *note auditing event: fd1. ‘cpython.run_stdin’ with no arguments. -- Describe: ’ and ‘’). -- Method: HTMLParser.handle_entityref (name) This method is called to process a named character reference of the form ‘&name;’ (e.g. ‘>’), where `name' is a general entity reference (e.g. ‘'gt'’). This method is never called if `convert_charrefs' is ‘True’. -- Method: HTMLParser.handle_charref (name) This method is called to process decimal and hexadecimal numeric character references of the form ‘&#NNN;’ and ‘&#xNNN;’. For example, the decimal equivalent for ‘>’ is ‘>’, whereas the hexadecimal is ‘>’; in this case the method will receive ‘'62'’ or ‘'x3E'’. This method is never called if `convert_charrefs' is ‘True’. -- Method: HTMLParser.handle_comment (data) This method is called when a comment is encountered (e.g. ‘’). For example, the comment ‘’ will cause this method to be called with the argument ‘' comment '’. The content of Internet Explorer conditional comments (condcoms) will also be sent to this method, so, for ‘’, this method will receive ‘'[if IE 9]>IE9-specific content’). The `decl' parameter will be the entire contents of the declaration inside the ‘’ markup (e.g. ‘'DOCTYPE html'’). -- Method: HTMLParser.handle_pi (data) Method called when a processing instruction is encountered. The `data' parameter will contain the entire processing instruction. For example, for the processing instruction ‘’, this method would be called as ‘handle_pi("proc color='red'")’. It is intended to be overridden by a derived class; the base class implementation does nothing. Note: The *note HTMLParser: 7bf. class uses the SGML syntactic rules for processing instructions. An XHTML processing instruction using the trailing ‘'?'’ will cause the ‘'?'’ to be included in `data'. -- Method: HTMLParser.unknown_decl (data) This method is called when an unrecognized declaration is read by the parser. The `data' parameter will be the entire contents of the declaration inside the ‘’ markup. It is sometimes useful to be overridden by a derived class. The base class implementation does nothing.  File: python.info, Node: Examples<19>, Prev: HTMLParser Methods, Up: html parser — Simple HTML and XHTML parser 5.20.2.3 Examples ................. The following class implements a parser that will be used to illustrate more examples: from html.parser import HTMLParser from html.entities import name2codepoint class MyHTMLParser(HTMLParser): def handle_starttag(self, tag, attrs): print("Start tag:", tag) for attr in attrs: print(" attr:", attr) def handle_endtag(self, tag): print("End tag :", tag) def handle_data(self, data): print("Data :", data) def handle_comment(self, data): print("Comment :", data) def handle_entityref(self, name): c = chr(name2codepoint[name]) print("Named ent:", c) def handle_charref(self, name): if name.startswith('x'): c = chr(int(name[1:], 16)) else: c = chr(int(name)) print("Num ent :", c) def handle_decl(self, data): print("Decl :", data) parser = MyHTMLParser() Parsing a doctype: >>> parser.feed('') Decl : DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd" Parsing an element with a few attributes and a title: >>> parser.feed('The Python logo') Start tag: img attr: ('src', 'python-logo.png') attr: ('alt', 'The Python logo') >>> >>> parser.feed('

Python

') Start tag: h1 Data : Python End tag : h1 The content of ‘script’ and ‘style’ elements is returned as is, without further parsing: >>> parser.feed('') Start tag: style attr: ('type', 'text/css') Data : #python { color: green } End tag : style >>> parser.feed('') Start tag: script attr: ('type', 'text/javascript') Data : alert("hello!"); End tag : script Parsing comments: >>> parser.feed('' ... '') Comment : a comment Comment : [if IE 9]>IE-specific content'’): >>> parser.feed('>>>') Named ent: > Num ent : > Num ent : > Feeding incomplete chunks to *note feed(): 26dc. works, but *note handle_data(): 26e4. might be called more than once (unless `convert_charrefs' is set to ‘True’): >>> for chunk in ['buff', 'ered ', 'text']: ... parser.feed(chunk) ... Start tag: span Data : buff Data : ered Data : text End tag : span Parsing invalid HTML (e.g. unquoted attributes) also works: >>> parser.feed('

tag soup

') Start tag: p Start tag: a attr: ('class', 'link') attr: ('href', '#main') Data : tag soup End tag : p End tag : a  File: python.info, Node: html entities — Definitions of HTML general entities, Next: XML Processing Modules, Prev: html parser — Simple HTML and XHTML parser, Up: Structured Markup Processing Tools 5.20.3 ‘html.entities’ — Definitions of HTML general entities ------------------------------------------------------------- `Source code:' Lib/html/entities.py(1) __________________________________________________________________ This module defines four dictionaries, *note html5: a15, *note name2codepoint: 26ef, *note codepoint2name: 26f0, and *note entitydefs: 26f1. -- Data: html.entities.html5 A dictionary that maps HTML5 named character references (2) to the equivalent Unicode character(s), e.g. ‘html5['gt;'] == '>'’. Note that the trailing semicolon is included in the name (e.g. ‘'gt;'’), however some of the names are accepted by the standard even without the semicolon: in this case the name is present with and without the ‘';'’. See also *note html.unescape(): 85a. New in version 3.3. -- Data: html.entities.entitydefs A dictionary mapping XHTML 1.0 entity definitions to their replacement text in ISO Latin-1. -- Data: html.entities.name2codepoint A dictionary that maps HTML entity names to the Unicode code points. -- Data: html.entities.codepoint2name A dictionary that maps Unicode code points to HTML entity names. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/html/entities.py (2) (1) See ‘https://www.w3.org/TR/html5/syntax.html#named-character-references’  File: python.info, Node: XML Processing Modules, Next: xml etree ElementTree — The ElementTree XML API, Prev: html entities — Definitions of HTML general entities, Up: Structured Markup Processing Tools 5.20.4 XML Processing Modules ----------------------------- `Source code:' Lib/xml/(1) __________________________________________________________________ Python’s interfaces for processing XML are grouped in the ‘xml’ package. Warning: The XML modules are not secure against erroneous or maliciously constructed data. If you need to parse untrusted or unauthenticated data see the *note XML vulnerabilities: 26f5. and *note The defusedxml Package: 26f6. sections. It is important to note that modules in the *note xml: 133. package require that there be at least one SAX-compliant XML parser available. The Expat parser is included with Python, so the *note xml.parsers.expat: 138. module will always be available. The documentation for the *note xml.dom: 134. and *note xml.sax: 13b. packages are the definition of the Python bindings for the DOM and SAX interfaces. The XML handling submodules are: * *note xml.etree.ElementTree: 137.: the ElementTree API, a simple and lightweight XML processor * *note xml.dom: 134.: the DOM API definition * *note xml.dom.minidom: 135.: a minimal DOM implementation * *note xml.dom.pulldom: 136.: support for building partial DOM trees * *note xml.sax: 13b.: SAX2 base classes and convenience functions * *note xml.parsers.expat: 138.: the Expat parser binding * Menu: * XML vulnerabilities:: * The defusedxml Package:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/  File: python.info, Node: XML vulnerabilities, Next: The defusedxml Package, Up: XML Processing Modules 5.20.4.1 XML vulnerabilities ............................ The XML processing modules are not secure against maliciously constructed data. An attacker can abuse XML features to carry out denial of service attacks, access local files, generate network connections to other machines, or circumvent firewalls. The following table gives an overview of the known attacks and whether the various modules are vulnerable to them. kind sax etree minidom pulldom xmlrpc ------------------------------------------------------------------------------------------------------------------------------ billion laughs `Vulnerable' `Vulnerable' `Vulnerable' `Vulnerable' `Vulnerable' quadratic blowup `Vulnerable' `Vulnerable' `Vulnerable' `Vulnerable' `Vulnerable' external entity expansion Safe (4) Safe (1) Safe (2) Safe (4) Safe (3) DTD(1) retrieval Safe (4) Safe Safe Safe (4) Safe decompression bomb Safe Safe Safe Safe `Vulnerable' 1. *note xml.etree.ElementTree: 137. doesn’t expand external entities and raises a ‘ParserError’ when an entity occurs. 2. *note xml.dom.minidom: 135. doesn’t expand external entities and simply returns the unexpanded entity verbatim. 3. ‘xmlrpclib’ doesn’t expand external entities and omits them. 4. Since Python 3.7.1, external general entities are no longer processed by default. billion laughs / exponential entity expansion The Billion Laughs(2) attack – also known as exponential entity expansion – uses multiple levels of nested entities. Each entity refers to another entity several times, and the final entity definition contains a small string. The exponential expansion results in several gigabytes of text and consumes lots of memory and CPU time. quadratic blowup entity expansion A quadratic blowup attack is similar to a Billion Laughs(3) attack; it abuses entity expansion, too. Instead of nested entities it repeats one large entity with a couple of thousand chars over and over again. The attack isn’t as efficient as the exponential case but it avoids triggering parser countermeasures that forbid deeply-nested entities. external entity expansion Entity declarations can contain more than just text for replacement. They can also point to external resources or local files. The XML parser accesses the resource and embeds the content into the XML document. DTD(4) retrieval Some XML libraries like Python’s *note xml.dom.pulldom: 136. retrieve document type definitions from remote or local locations. The feature has similar implications as the external entity expansion issue. decompression bomb Decompression bombs (aka ZIP bomb(5)) apply to all XML libraries that can parse compressed XML streams such as gzipped HTTP streams or LZMA-compressed files. For an attacker it can reduce the amount of transmitted data by three magnitudes or more. The documentation for defusedxml(6) on PyPI has further information about all known attack vectors with examples and references. ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Document_type_definition (2) https://en.wikipedia.org/wiki/Billion_laughs (3) https://en.wikipedia.org/wiki/Billion_laughs (4) https://en.wikipedia.org/wiki/Document_type_definition (5) https://en.wikipedia.org/wiki/Zip_bomb (6) https://pypi.org/project/defusedxml/  File: python.info, Node: The defusedxml Package, Prev: XML vulnerabilities, Up: XML Processing Modules 5.20.4.2 The ‘defusedxml’ Package ................................. defusedxml(1) is a pure Python package with modified subclasses of all stdlib XML parsers that prevent any potentially malicious operation. Use of this package is recommended for any server code that parses untrusted XML data. The package also ships with example exploits and extended documentation on more XML exploits such as XPath injection. ---------- Footnotes ---------- (1) https://pypi.org/project/defusedxml/  File: python.info, Node: xml etree ElementTree — The ElementTree XML API, Next: xml dom — The Document Object Model API, Prev: XML Processing Modules, Up: Structured Markup Processing Tools 5.20.5 ‘xml.etree.ElementTree’ — The ElementTree XML API -------------------------------------------------------- `Source code:' Lib/xml/etree/ElementTree.py(1) __________________________________________________________________ The *note xml.etree.ElementTree: 137. module implements a simple and efficient API for parsing and creating XML data. Changed in version 3.3: This module will use a fast implementation whenever available. The ‘xml.etree.cElementTree’ module is deprecated. Warning: The *note xml.etree.ElementTree: 137. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. * Menu: * Tutorial:: * XPath support:: * Reference: Reference<2>. * XInclude support:: * Reference: Reference<3>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/etree/ElementTree.py  File: python.info, Node: Tutorial, Next: XPath support, Up: xml etree ElementTree — The ElementTree XML API 5.20.5.1 Tutorial ................. This is a short tutorial for using *note xml.etree.ElementTree: 137. (‘ET’ in short). The goal is to demonstrate some of the building blocks and basic concepts of the module. * Menu: * XML tree and elements:: * Parsing XML:: * Pull API for non-blocking parsing:: * Finding interesting elements:: * Modifying an XML File:: * Building XML documents:: * Parsing XML with Namespaces:: * Additional resources::  File: python.info, Node: XML tree and elements, Next: Parsing XML, Up: Tutorial 5.20.5.2 XML tree and elements .............................. XML is an inherently hierarchical data format, and the most natural way to represent it is with a tree. ‘ET’ has two classes for this purpose - *note ElementTree: 917. represents the whole XML document as a tree, and *note Element: ac4. represents a single node in this tree. Interactions with the whole document (reading and writing to/from files) are usually done on the *note ElementTree: 917. level. Interactions with a single XML element and its sub-elements are done on the *note Element: ac4. level.  File: python.info, Node: Parsing XML, Next: Pull API for non-blocking parsing, Prev: XML tree and elements, Up: Tutorial 5.20.5.3 Parsing XML .................... We’ll be using the following XML document as the sample data for this section: 1 2008 141100 4 2011 59900 68 2011 13600 We can import this data by reading from a file: import xml.etree.ElementTree as ET tree = ET.parse('country_data.xml') root = tree.getroot() Or directly from a string: root = ET.fromstring(country_data_as_string) *note fromstring(): 2700. parses XML from a string directly into an *note Element: ac4, which is the root element of the parsed tree. Other parsing functions may create an *note ElementTree: 917. Check the documentation to be sure. As an *note Element: ac4, ‘root’ has a tag and a dictionary of attributes: >>> root.tag 'data' >>> root.attrib {} It also has children nodes over which we can iterate: >>> for child in root: ... print(child.tag, child.attrib) ... country {'name': 'Liechtenstein'} country {'name': 'Singapore'} country {'name': 'Panama'} Children are nested, and we can access specific child nodes by index: >>> root[0][1].text '2008' Note: Not all elements of the XML input will end up as elements of the parsed tree. Currently, this module skips over any XML comments, processing instructions, and document type declarations in the input. Nevertheless, trees built using this module’s API rather than parsing from XML text can have comments and processing instructions in them; they will be included when generating XML output. A document type declaration may be accessed by passing a custom *note TreeBuilder: 253. instance to the *note XMLParser: 252. constructor.  File: python.info, Node: Pull API for non-blocking parsing, Next: Finding interesting elements, Prev: Parsing XML, Up: Tutorial 5.20.5.4 Pull API for non-blocking parsing .......................................... Most parsing functions provided by this module require the whole document to be read at once before returning any result. It is possible to use an *note XMLParser: 252. and feed data into it incrementally, but it is a push API that calls methods on a callback target, which is too low-level and inconvenient for most needs. Sometimes what the user really wants is to be able to parse XML incrementally, without blocking operations, while enjoying the convenience of fully constructed *note Element: ac4. objects. The most powerful tool for doing this is *note XMLPullParser: 913. It does not require a blocking read to obtain the XML data, and is instead fed with data incrementally with *note XMLPullParser.feed(): 2702. calls. To get the parsed XML elements, call *note XMLPullParser.read_events(): 2703. Here is an example: >>> parser = ET.XMLPullParser(['start', 'end']) >>> parser.feed('sometext') >>> list(parser.read_events()) [('start', )] >>> parser.feed(' more text') >>> for event, elem in parser.read_events(): ... print(event) ... print(elem.tag, 'text=', elem.text) ... end The obvious use case is applications that operate in a non-blocking fashion where the XML data is being received from a socket or read incrementally from some storage device. In such cases, blocking reads are unacceptable. Because it’s so flexible, *note XMLPullParser: 913. can be inconvenient to use for simpler use-cases. If you don’t mind your application blocking on reading XML data but would still like to have incremental parsing capabilities, take a look at *note iterparse(): 948. It can be useful when you’re reading a large XML document and don’t want to hold it wholly in memory.  File: python.info, Node: Finding interesting elements, Next: Modifying an XML File, Prev: Pull API for non-blocking parsing, Up: Tutorial 5.20.5.5 Finding interesting elements ..................................... *note Element: ac4. has some useful methods that help iterate recursively over all the sub-tree below it (its children, their children, and so on). For example, *note Element.iter(): ce7.: >>> for neighbor in root.iter('neighbor'): ... print(neighbor.attrib) ... {'name': 'Austria', 'direction': 'E'} {'name': 'Switzerland', 'direction': 'W'} {'name': 'Malaysia', 'direction': 'N'} {'name': 'Costa Rica', 'direction': 'W'} {'name': 'Colombia', 'direction': 'E'} *note Element.findall(): 2705. finds only elements with a tag which are direct children of the current element. *note Element.find(): 2706. finds the `first' child with a particular tag, and *note Element.text: 2707. accesses the element’s text content. *note Element.get(): 2708. accesses the element’s attributes: >>> for country in root.findall('country'): ... rank = country.find('rank').text ... name = country.get('name') ... print(name, rank) ... Liechtenstein 1 Singapore 4 Panama 68 More sophisticated specification of which elements to look for is possible by using *note XPath: 41a.  File: python.info, Node: Modifying an XML File, Next: Building XML documents, Prev: Finding interesting elements, Up: Tutorial 5.20.5.6 Modifying an XML File .............................. *note ElementTree: 917. provides a simple way to build XML documents and write them to files. The *note ElementTree.write(): 918. method serves this purpose. Once created, an *note Element: ac4. object may be manipulated by directly changing its fields (such as *note Element.text: 2707.), adding and modifying attributes (*note Element.set(): 270a. method), as well as adding new children (for example with *note Element.append(): 270b.). Let’s say we want to add one to each country’s rank, and add an ‘updated’ attribute to the rank element: >>> for rank in root.iter('rank'): ... new_rank = int(rank.text) + 1 ... rank.text = str(new_rank) ... rank.set('updated', 'yes') ... >>> tree.write('output.xml') Our XML now looks like this: 2 2008 141100 5 2011 59900 69 2011 13600 We can remove elements using *note Element.remove(): 270c. Let’s say we want to remove all countries with a rank higher than 50: >>> for country in root.findall('country'): ... # using root.findall() to avoid removal during traversal ... rank = int(country.find('rank').text) ... if rank > 50: ... root.remove(country) ... >>> tree.write('output.xml') Note that concurrent modification while iterating can lead to problems, just like when iterating and modifying Python lists or dicts. Therefore, the example first collects all matching elements with ‘root.findall()’, and only then iterates over the list of matches. Our XML now looks like this: 2 2008 141100 5 2011 59900  File: python.info, Node: Building XML documents, Next: Parsing XML with Namespaces, Prev: Modifying an XML File, Up: Tutorial 5.20.5.7 Building XML documents ............................... The *note SubElement(): 270e. function also provides a convenient way to create new sub-elements for a given element: >>> a = ET.Element('a') >>> b = ET.SubElement(a, 'b') >>> c = ET.SubElement(a, 'c') >>> d = ET.SubElement(c, 'd') >>> ET.dump(a)  File: python.info, Node: Parsing XML with Namespaces, Next: Additional resources, Prev: Building XML documents, Up: Tutorial 5.20.5.8 Parsing XML with Namespaces .................................... If the XML input has namespaces(1), tags and attributes with prefixes in the form ‘prefix:sometag’ get expanded to ‘{uri}sometag’ where the `prefix' is replaced by the full `URI'. Also, if there is a default namespace(2), that full URI gets prepended to all of the non-prefixed tags. Here is an XML example that incorporates two namespaces, one with the prefix “fictional” and the other serving as the default namespace: John Cleese Lancelot Archie Leach Eric Idle Sir Robin Gunther Commander Clement One way to search and explore this XML example is to manually add the URI to every tag or attribute in the xpath of a *note find(): 2706. or *note findall(): 2705.: root = fromstring(xml_text) for actor in root.findall('{http://people.example.com}actor'): name = actor.find('{http://people.example.com}name') print(name.text) for char in actor.findall('{http://characters.example.com}character'): print(' |-->', char.text) A better way to search the namespaced XML example is to create a dictionary with your own prefixes and use those in the search functions: ns = {'real_person': 'http://people.example.com', 'role': 'http://characters.example.com'} for actor in root.findall('real_person:actor', ns): name = actor.find('real_person:name', ns) print(name.text) for char in actor.findall('role:character', ns): print(' |-->', char.text) These two approaches both output: John Cleese |--> Lancelot |--> Archie Leach Eric Idle |--> Sir Robin |--> Gunther |--> Commander Clement ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/XML_namespace (2) https://www.w3.org/TR/xml-names/#defaulting  File: python.info, Node: Additional resources, Prev: Parsing XML with Namespaces, Up: Tutorial 5.20.5.9 Additional resources ............................. See ‘http://effbot.org/zone/element-index.htm’ for tutorials and links to other docs.  File: python.info, Node: XPath support, Next: Reference<2>, Prev: Tutorial, Up: xml etree ElementTree — The ElementTree XML API 5.20.5.10 XPath support ....................... This module provides limited support for XPath expressions(1) for locating elements in a tree. The goal is to support a small subset of the abbreviated syntax; a full XPath engine is outside the scope of the module. * Menu: * Example: Example<10>. * Supported XPath syntax:: ---------- Footnotes ---------- (1) https://www.w3.org/TR/xpath  File: python.info, Node: Example<10>, Next: Supported XPath syntax, Up: XPath support 5.20.5.11 Example ................. Here’s an example that demonstrates some of the XPath capabilities of the module. We’ll be using the ‘countrydata’ XML document from the *note Parsing XML: 26fe. section: import xml.etree.ElementTree as ET root = ET.fromstring(countrydata) # Top-level elements root.findall(".") # All 'neighbor' grand-children of 'country' children of the top-level # elements root.findall("./country/neighbor") # Nodes with name='Singapore' that have a 'year' child root.findall(".//year/..[@name='Singapore']") # 'year' nodes that are children of nodes with name='Singapore' root.findall(".//*[@name='Singapore']/year") # All 'neighbor' nodes that are the second child of their parent root.findall(".//neighbor[2]") For XML with namespaces, use the usual qualified ‘{namespace}tag’ notation: # All dublin-core "title" tags in the document root.findall(".//{http://purl.org/dc/elements/1.1/}title")  File: python.info, Node: Supported XPath syntax, Prev: Example<10>, Up: XPath support 5.20.5.12 Supported XPath syntax ................................ Syntax Meaning --------------------------------------------------------------------------------------- ‘tag’ Selects all child elements with the given tag. For example, ‘spam’ selects all child elements named ‘spam’, and ‘spam/egg’ selects all grandchildren named ‘egg’ in all children named ‘spam’. ‘{namespace}*’ selects all tags in the given namespace, ‘{*}spam’ selects tags named ‘spam’ in any (or no) namespace, and ‘{}*’ only selects tags that are not in a namespace. Changed in version 3.8: Support for star-wildcards was added. ‘*’ Selects all child elements, including comments and processing instructions. For example, ‘*/egg’ selects all grandchildren named ‘egg’. ‘.’ Selects the current node. This is mostly useful at the beginning of the path, to indicate that it’s a relative path. ‘//’ Selects all subelements, on all levels beneath the current element. For example, ‘.//egg’ selects all ‘egg’ elements in the entire tree. ‘..’ Selects the parent element. Returns ‘None’ if the path attempts to reach the ancestors of the start element (the element ‘find’ was called on). ‘[@attrib]’ Selects all elements that have the given attribute. ‘[@attrib='value']’ Selects all elements for which the given attribute has the given value. The value cannot contain quotes. ‘[tag]’ Selects all elements that have a child named ‘tag’. Only immediate children are supported. ‘[.='text']’ Selects all elements whose complete text content, including descendants, equals the given ‘text’. New in version 3.7. ‘[tag='text']’ Selects all elements that have a child named ‘tag’ whose complete text content, including descendants, equals the given ‘text’. ‘[position]’ Selects all elements that are located at the given position. The position can be either an integer (1 is the first position), the expression ‘last()’ (for the last position), or a position relative to the last position (e.g. ‘last()-1’). Predicates (expressions within square brackets) must be preceded by a tag name, an asterisk, or another predicate. ‘position’ predicates must be preceded by a tag name.  File: python.info, Node: Reference<2>, Next: XInclude support, Prev: XPath support, Up: xml etree ElementTree — The ElementTree XML API 5.20.5.13 Reference ................... * Menu: * Functions: Functions<6>.  File: python.info, Node: Functions<6>, Up: Reference<2> 5.20.5.14 Functions ................... -- Function: xml.etree.ElementTree.canonicalize (xml_data=None, *, out=None, from_file=None, **options) C14N 2.0(1) transformation function. Canonicalization is a way to normalise XML output in a way that allows byte-by-byte comparisons and digital signatures. It reduced the freedom that XML serializers have and instead generates a more constrained XML representation. The main restrictions regard the placement of namespace declarations, the ordering of attributes, and ignorable whitespace. This function takes an XML data string (`xml_data') or a file path or file-like object (`from_file') as input, converts it to the canonical form, and writes it out using the `out' file(-like) object, if provided, or returns it as a text string if not. The output file receives text, not bytes. It should therefore be opened in text mode with ‘utf-8’ encoding. Typical uses: xml_data = "..." print(canonicalize(xml_data)) with open("c14n_output.xml", mode='w', encoding='utf-8') as out_file: canonicalize(xml_data, out=out_file) with open("c14n_output.xml", mode='w', encoding='utf-8') as out_file: canonicalize(from_file="inputfile.xml", out=out_file) The configuration `options' are as follows: - `with_comments': set to true to include comments (default: false) - `strip_text': set to true to strip whitespace before and after text content (default: false) - `rewrite_prefixes': set to true to replace namespace prefixes by “n{number}” (default: false) - `qname_aware_tags': a set of qname aware tag names in which prefixes should be replaced in text content (default: empty) - `qname_aware_attrs': a set of qname aware attribute names in which prefixes should be replaced in text content (default: empty) - `exclude_attrs': a set of attribute names that should not be serialised - `exclude_tags': a set of tag names that should not be serialised In the option list above, “a set” refers to any collection or iterable of strings, no ordering is expected. New in version 3.8. -- Function: xml.etree.ElementTree.Comment (text=None) Comment element factory. This factory function creates a special element that will be serialized as an XML comment by the standard serializer. The comment string can be either a bytestring or a Unicode string. `text' is a string containing the comment string. Returns an element instance representing a comment. Note that *note XMLParser: 252. skips over comments in the input instead of creating comment objects for them. An *note ElementTree: 917. will only contain comment nodes if they have been inserted into to the tree using one of the *note Element: ac4. methods. -- Function: xml.etree.ElementTree.dump (elem) Writes an element tree or element structure to sys.stdout. This function should be used for debugging only. The exact output format is implementation dependent. In this version, it’s written as an ordinary XML file. `elem' is an element tree or an individual element. Changed in version 3.8: The *note dump(): 2719. function now preserves the attribute order specified by the user. -- Function: xml.etree.ElementTree.fromstring (text, parser=None) Parses an XML section from a string constant. Same as *note XML(): 271a. `text' is a string containing XML data. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns an *note Element: ac4. instance. -- Function: xml.etree.ElementTree.fromstringlist (sequence, parser=None) Parses an XML document from a sequence of string fragments. `sequence' is a list or other sequence containing XML data fragments. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns an *note Element: ac4. instance. New in version 3.2. -- Function: xml.etree.ElementTree.iselement (element) Check if an object appears to be a valid element object. `element' is an element instance. Return ‘True’ if this is an element object. -- Function: xml.etree.ElementTree.iterparse (source, events=None, parser=None) Parses an XML section into an element tree incrementally, and reports what’s going on to the user. `source' is a filename or *note file object: b42. containing XML data. `events' is a sequence of events to report back. The supported events are the strings ‘"start"’, ‘"end"’, ‘"comment"’, ‘"pi"’, ‘"start-ns"’ and ‘"end-ns"’ (the “ns” events are used to get detailed namespace information). If `events' is omitted, only ‘"end"’ events are reported. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. `parser' must be a subclass of *note XMLParser: 252. and can only use the default *note TreeBuilder: 253. as a target. Returns an *note iterator: 112e. providing ‘(event, elem)’ pairs. Note that while *note iterparse(): 948. builds the tree incrementally, it issues blocking reads on `source' (or the file it names). As such, it’s unsuitable for applications where blocking reads can’t be made. For fully non-blocking parsing, see *note XMLPullParser: 913. Note: *note iterparse(): 948. only guarantees that it has seen the “>” character of a starting tag when it emits a “start” event, so the attributes are defined, but the contents of the text and tail attributes are undefined at that point. The same applies to the element children; they may or may not be present. If you need a fully populated element, look for “end” events instead. Deprecated since version 3.4: The `parser' argument. Changed in version 3.8: The ‘comment’ and ‘pi’ events were added. -- Function: xml.etree.ElementTree.parse (source, parser=None) Parses an XML section into an element tree. `source' is a filename or file object containing XML data. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns an *note ElementTree: 917. instance. -- Function: xml.etree.ElementTree.ProcessingInstruction (target, text=None) PI element factory. This factory function creates a special element that will be serialized as an XML processing instruction. `target' is a string containing the PI target. `text' is a string containing the PI contents, if given. Returns an element instance, representing a processing instruction. Note that *note XMLParser: 252. skips over processing instructions in the input instead of creating comment objects for them. An *note ElementTree: 917. will only contain processing instruction nodes if they have been inserted into to the tree using one of the *note Element: ac4. methods. -- Function: xml.etree.ElementTree.register_namespace (prefix, uri) Registers a namespace prefix. The registry is global, and any existing mapping for either the given prefix or the namespace URI will be removed. `prefix' is a namespace prefix. `uri' is a namespace uri. Tags and attributes in this namespace will be serialized with the given prefix, if at all possible. New in version 3.2. -- Function: xml.etree.ElementTree.SubElement (parent, tag, attrib={}, **extra) Subelement factory. This function creates an element instance, and appends it to an existing element. The element name, attribute names, and attribute values can be either bytestrings or Unicode strings. `parent' is the parent element. `tag' is the subelement name. `attrib' is an optional dictionary, containing element attributes. `extra' contains additional attributes, given as keyword arguments. Returns an element instance. -- Function: xml.etree.ElementTree.tostring (element, encoding="us-ascii", method="xml", *, xml_declaration=None, default_namespace=None, short_empty_elements=True) Generates a string representation of an XML element, including all subelements. `element' is an *note Element: ac4. instance. `encoding' (2) is the output encoding (default is US-ASCII). Use ‘encoding="unicode"’ to generate a Unicode string (otherwise, a bytestring is generated). `method' is either ‘"xml"’, ‘"html"’ or ‘"text"’ (default is ‘"xml"’). `xml_declaration', `default_namespace' and `short_empty_elements' has the same meaning as in *note ElementTree.write(): 918. Returns an (optionally) encoded string containing the XML data. New in version 3.4: The `short_empty_elements' parameter. New in version 3.8: The `xml_declaration' and `default_namespace' parameters. Changed in version 3.8: The *note tostring(): 915. function now preserves the attribute order specified by the user. -- Function: xml.etree.ElementTree.tostringlist (element, encoding="us-ascii", method="xml", *, xml_declaration=None, default_namespace=None, short_empty_elements=True) Generates a string representation of an XML element, including all subelements. `element' is an *note Element: ac4. instance. `encoding' (3) is the output encoding (default is US-ASCII). Use ‘encoding="unicode"’ to generate a Unicode string (otherwise, a bytestring is generated). `method' is either ‘"xml"’, ‘"html"’ or ‘"text"’ (default is ‘"xml"’). `xml_declaration', `default_namespace' and `short_empty_elements' has the same meaning as in *note ElementTree.write(): 918. Returns a list of (optionally) encoded strings containing the XML data. It does not guarantee any specific sequence, except that ‘b"".join(tostringlist(element)) == tostring(element)’. New in version 3.2. New in version 3.4: The `short_empty_elements' parameter. New in version 3.8: The `xml_declaration' and `default_namespace' parameters. Changed in version 3.8: The *note tostringlist(): 916. function now preserves the attribute order specified by the user. -- Function: xml.etree.ElementTree.XML (text, parser=None) Parses an XML section from a string constant. This function can be used to embed “XML literals” in Python code. `text' is a string containing XML data. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns an *note Element: ac4. instance. -- Function: xml.etree.ElementTree.XMLID (text, parser=None) Parses an XML section from a string constant, and also returns a dictionary which maps from element id:s to elements. `text' is a string containing XML data. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns a tuple containing an *note Element: ac4. instance and a dictionary. ---------- Footnotes ---------- (1) https://www.w3.org/TR/xml-c14n2/ (2) (1) The encoding string included in XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’. (3) (1) The encoding string included in XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.  File: python.info, Node: XInclude support, Next: Reference<3>, Prev: Reference<2>, Up: xml etree ElementTree — The ElementTree XML API 5.20.5.15 XInclude support .......................... This module provides limited support for XInclude directives(1), via the ‘xml.etree.ElementInclude’ helper module. This module can be used to insert subtrees and text strings into element trees, based on information in the tree. * Menu: * Example: Example<11>. ---------- Footnotes ---------- (1) https://www.w3.org/TR/xinclude/  File: python.info, Node: Example<11>, Up: XInclude support 5.20.5.16 Example ................. Here’s an example that demonstrates use of the XInclude module. To include an XML document in the current document, use the ‘{http://www.w3.org/2001/XInclude}include’ element and set the `parse' attribute to ‘"xml"’, and use the `href' attribute to specify the document to include. By default, the `href' attribute is treated as a file name. You can use custom loaders to override this behaviour. Also note that the standard helper does not support XPointer syntax. To process this file, load it as usual, and pass the root element to the *note xml.etree.ElementTree: 137. module: from xml.etree import ElementTree, ElementInclude tree = ElementTree.parse("document.xml") root = tree.getroot() ElementInclude.include(root) The ElementInclude module replaces the ‘{http://www.w3.org/2001/XInclude}include’ element with the root element from the `source.xml' document. The result might look something like this: This is a paragraph. If the `parse' attribute is omitted, it defaults to “xml”. The href attribute is required. To include a text document, use the ‘{http://www.w3.org/2001/XInclude}include’ element, and set the `parse' attribute to “text”: Copyright (c) . The result might look something like: Copyright (c) 2003.  File: python.info, Node: Reference<3>, Prev: XInclude support, Up: xml etree ElementTree — The ElementTree XML API 5.20.5.17 Reference ................... * Menu: * Functions: Functions<7>. * Element Objects:: * ElementTree Objects:: * QName Objects:: * TreeBuilder Objects:: * XMLParser Objects:: * XMLPullParser Objects:: * Exceptions: Exceptions<15>.  File: python.info, Node: Functions<7>, Next: Element Objects, Up: Reference<3> 5.20.5.18 Functions ................... -- Function: xml.etree.ElementInclude.default_loader (href, parse, encoding=None) Default loader. This default loader reads an included resource from disk. `href' is a URL. `parse' is for parse mode either “xml” or “text”. `encoding' is an optional text encoding. If not given, encoding is ‘utf-8’. Returns the expanded resource. If the parse mode is ‘"xml"’, this is an ElementTree instance. If the parse mode is “text”, this is a Unicode string. If the loader fails, it can return None or raise an exception. -- Function: xml.etree.ElementInclude.include (elem, loader=None) This function expands XInclude directives. `elem' is the root element. `loader' is an optional resource loader. If omitted, it defaults to *note default_loader(): 2725. If given, it should be a callable that implements the same interface as *note default_loader(): 2725. Returns the expanded resource. If the parse mode is ‘"xml"’, this is an ElementTree instance. If the parse mode is “text”, this is a Unicode string. If the loader fails, it can return None or raise an exception.  File: python.info, Node: Element Objects, Next: ElementTree Objects, Prev: Functions<7>, Up: Reference<3> 5.20.5.19 Element Objects ......................... -- Class: xml.etree.ElementTree.Element (tag, attrib={}, **extra) Element class. This class defines the Element interface, and provides a reference implementation of this interface. The element name, attribute names, and attribute values can be either bytestrings or Unicode strings. `tag' is the element name. `attrib' is an optional dictionary, containing element attributes. `extra' contains additional attributes, given as keyword arguments. -- Attribute: tag A string identifying what kind of data this element represents (the element type, in other words). -- Attribute: text -- Attribute: tail These attributes can be used to hold additional data associated with the element. Their values are usually strings but may be any application-specific object. If the element is created from an XML file, the `text' attribute holds either the text between the element’s start tag and its first child or end tag, or ‘None’, and the `tail' attribute holds either the text between the element’s end tag and the next tag, or ‘None’. For the XML data 1234 the `a' element has ‘None’ for both `text' and `tail' attributes, the `b' element has `text' ‘"1"’ and `tail' ‘"4"’, the `c' element has `text' ‘"2"’ and `tail' ‘None’, and the `d' element has `text' ‘None’ and `tail' ‘"3"’. To collect the inner text of an element, see *note itertext(): b53, for example ‘"".join(element.itertext())’. Applications may store arbitrary objects in these attributes. -- Attribute: attrib A dictionary containing the element’s attributes. Note that while the `attrib' value is always a real mutable Python dictionary, an ElementTree implementation may choose to use another internal representation, and create the dictionary only if someone asks for it. To take advantage of such implementations, use the dictionary methods below whenever possible. The following dictionary-like methods work on the element attributes. -- Method: clear () Resets an element. This function removes all subelements, clears all attributes, and sets the text and tail attributes to ‘None’. -- Method: get (key, default=None) Gets the element attribute named `key'. Returns the attribute value, or `default' if the attribute was not found. -- Method: items () Returns the element attributes as a sequence of (name, value) pairs. The attributes are returned in an arbitrary order. -- Method: keys () Returns the elements attribute names as a list. The names are returned in an arbitrary order. -- Method: set (key, value) Set the attribute `key' on the element to `value'. The following methods work on the element’s children (subelements). -- Method: append (subelement) Adds the element `subelement' to the end of this element’s internal list of subelements. Raises *note TypeError: 192. if `subelement' is not an *note Element: ac4. -- Method: extend (subelements) Appends `subelements' from a sequence object with zero or more elements. Raises *note TypeError: 192. if a subelement is not an *note Element: ac4. New in version 3.2. -- Method: find (match, namespaces=None) Finds the first subelement matching `match'. `match' may be a tag name or a *note path: 41a. Returns an element instance or ‘None’. `namespaces' is an optional mapping from namespace prefix to full name. Pass ‘''’ as prefix to move all unprefixed tag names in the expression into the given namespace. -- Method: findall (match, namespaces=None) Finds all matching subelements, by tag name or *note path: 41a. Returns a list containing all matching elements in document order. `namespaces' is an optional mapping from namespace prefix to full name. Pass ‘''’ as prefix to move all unprefixed tag names in the expression into the given namespace. -- Method: findtext (match, default=None, namespaces=None) Finds text for the first subelement matching `match'. `match' may be a tag name or a *note path: 41a. Returns the text content of the first matching element, or `default' if no element was found. Note that if the matching element has no text content an empty string is returned. `namespaces' is an optional mapping from namespace prefix to full name. Pass ‘''’ as prefix to move all unprefixed tag names in the expression into the given namespace. -- Method: getchildren () Deprecated since version 3.2, will be removed in version 3.9: Use ‘list(elem)’ or iteration. -- Method: getiterator (tag=None) Deprecated since version 3.2, will be removed in version 3.9: Use method *note Element.iter(): ce7. instead. -- Method: insert (index, subelement) Inserts `subelement' at the given position in this element. Raises *note TypeError: 192. if `subelement' is not an *note Element: ac4. -- Method: iter (tag=None) Creates a tree *note iterator: 112e. with the current element as the root. The iterator iterates over this element and all elements below it, in document (depth first) order. If `tag' is not ‘None’ or ‘'*'’, only elements whose tag equals `tag' are returned from the iterator. If the tree structure is modified during iteration, the result is undefined. New in version 3.2. -- Method: iterfind (match, namespaces=None) Finds all matching subelements, by tag name or *note path: 41a. Returns an iterable yielding all matching elements in document order. `namespaces' is an optional mapping from namespace prefix to full name. New in version 3.2. -- Method: itertext () Creates a text iterator. The iterator loops over this element and all subelements, in document order, and returns all inner text. New in version 3.2. -- Method: makeelement (tag, attrib) Creates a new element object of the same type as this element. Do not call this method, use the *note SubElement(): 270e. factory function instead. -- Method: remove (subelement) Removes `subelement' from the element. Unlike the find* methods this method compares elements based on the instance identity, not on tag value or contents. *note Element: ac4. objects also support the following sequence type methods for working with subelements: *note __delitem__(): c63, *note __getitem__(): 27c, *note __setitem__(): c62, *note __len__(): dcb. Caution: Elements with no subelements will test as ‘False’. This behavior will change in future versions. Use specific ‘len(elem)’ or ‘elem is None’ test instead. element = root.find('foo') if not element: # careful! print("element not found, or element has no subelements") if element is None: print("element not found") Prior to Python 3.8, the serialisation order of the XML attributes of elements was artificially made predictable by sorting the attributes by their name. Based on the now guaranteed ordering of dicts, this arbitrary reordering was removed in Python 3.8 to preserve the order in which attributes were originally parsed or created by user code. In general, user code should try not to depend on a specific ordering of attributes, given that the XML Information Set(1) explicitly excludes the attribute order from conveying information. Code should be prepared to deal with any ordering on input. In cases where deterministic XML output is required, e.g. for cryptographic signing or test data sets, canonical serialisation is available with the *note canonicalize(): 2717. function. In cases where canonical output is not applicable but a specific attribute order is still desirable on output, code should aim for creating the attributes directly in the desired order, to avoid perceptual mismatches for readers of the code. In cases where this is difficult to achieve, a recipe like the following can be applied prior to serialisation to enforce an order independently from the Element creation: def reorder_attributes(root): for el in root.iter(): attrib = el.attrib if len(attrib) > 1: # adjust attribute order, e.g. by sorting attribs = sorted(attrib.items()) attrib.clear() attrib.update(attribs) ---------- Footnotes ---------- (1) https://www.w3.org/TR/xml-infoset/  File: python.info, Node: ElementTree Objects, Next: QName Objects, Prev: Element Objects, Up: Reference<3> 5.20.5.20 ElementTree Objects ............................. -- Class: xml.etree.ElementTree.ElementTree (element=None, file=None) ElementTree wrapper class. This class represents an entire element hierarchy, and adds some extra support for serialization to and from standard XML. `element' is the root element. The tree is initialized with the contents of the XML `file' if given. -- Method: _setroot (element) Replaces the root element for this tree. This discards the current contents of the tree, and replaces it with the given element. Use with care. `element' is an element instance. -- Method: find (match, namespaces=None) Same as *note Element.find(): 2706, starting at the root of the tree. -- Method: findall (match, namespaces=None) Same as *note Element.findall(): 2705, starting at the root of the tree. -- Method: findtext (match, default=None, namespaces=None) Same as *note Element.findtext(): 272f, starting at the root of the tree. -- Method: getiterator (tag=None) Deprecated since version 3.2, will be removed in version 3.9: Use method *note ElementTree.iter(): 273b. instead. -- Method: getroot () Returns the root element for this tree. -- Method: iter (tag=None) Creates and returns a tree iterator for the root element. The iterator loops over all elements in this tree, in section order. `tag' is the tag to look for (default is to return all elements). -- Method: iterfind (match, namespaces=None) Same as *note Element.iterfind(): b52, starting at the root of the tree. New in version 3.2. -- Method: parse (source, parser=None) Loads an external XML section into this element tree. `source' is a file name or *note file object: b42. `parser' is an optional parser instance. If not given, the standard *note XMLParser: 252. parser is used. Returns the section root element. -- Method: write (file, encoding="us-ascii", xml_declaration=None, default_namespace=None, method="xml", *, short_empty_elements=True) Writes the element tree to a file, as XML. `file' is a file name, or a *note file object: b42. opened for writing. `encoding' (1) is the output encoding (default is US-ASCII). `xml_declaration' controls if an XML declaration should be added to the file. Use ‘False’ for never, ‘True’ for always, ‘None’ for only if not US-ASCII or UTF-8 or Unicode (default is ‘None’). `default_namespace' sets the default XML namespace (for “xmlns”). `method' is either ‘"xml"’, ‘"html"’ or ‘"text"’ (default is ‘"xml"’). The keyword-only `short_empty_elements' parameter controls the formatting of elements that contain no content. If ‘True’ (the default), they are emitted as a single self-closed tag, otherwise they are emitted as a pair of start/end tags. The output is either a string (*note str: 330.) or binary (*note bytes: 331.). This is controlled by the `encoding' argument. If `encoding' is ‘"unicode"’, the output is a string; otherwise, it’s binary. Note that this may conflict with the type of `file' if it’s an open *note file object: b42.; make sure you do not try to write a string to a binary stream and vice versa. New in version 3.4: The `short_empty_elements' parameter. Changed in version 3.8: The *note write(): 918. method now preserves the attribute order specified by the user. This is the XML file that is going to be manipulated: Example page

Moved to example.org or example.com.

Example of changing the attribute “target” of every link in first paragraph: >>> from xml.etree.ElementTree import ElementTree >>> tree = ElementTree() >>> tree.parse("index.xhtml") >>> p = tree.find("body/p") # Finds first occurrence of tag p in body >>> p >>> links = list(p.iter("a")) # Returns list of all links >>> links [, ] >>> for i in links: # Iterates through all found links ... i.attrib["target"] = "blank" >>> tree.write("output.xhtml") ---------- Footnotes ---------- (1) (1) The encoding string included in XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.  File: python.info, Node: QName Objects, Next: TreeBuilder Objects, Prev: ElementTree Objects, Up: Reference<3> 5.20.5.21 QName Objects ....................... -- Class: xml.etree.ElementTree.QName (text_or_uri, tag=None) QName wrapper. This can be used to wrap a QName attribute value, in order to get proper namespace handling on output. `text_or_uri' is a string containing the QName value, in the form {uri}local, or, if the tag argument is given, the URI part of a QName. If `tag' is given, the first argument is interpreted as a URI, and this argument is interpreted as a local name. *note QName: 2741. instances are opaque.  File: python.info, Node: TreeBuilder Objects, Next: XMLParser Objects, Prev: QName Objects, Up: Reference<3> 5.20.5.22 TreeBuilder Objects ............................. -- Class: xml.etree.ElementTree.TreeBuilder (element_factory=None, *, comment_factory=None, pi_factory=None, insert_comments=False, insert_pis=False) Generic element structure builder. This builder converts a sequence of start, data, end, comment and pi method calls to a well-formed element structure. You can use this class to build an element structure using a custom XML parser, or a parser for some other XML-like format. `element_factory', when given, must be a callable accepting two positional arguments: a tag and a dict of attributes. It is expected to return a new element instance. The `comment_factory' and `pi_factory' functions, when given, should behave like the *note Comment(): 2718. and *note ProcessingInstruction(): 271d. functions to create comments and processing instructions. When not given, the default factories will be used. When `insert_comments' and/or `insert_pis' is true, comments/pis will be inserted into the tree if they appear within the root element (but not outside of it). -- Method: close () Flushes the builder buffers, and returns the toplevel document element. Returns an *note Element: ac4. instance. -- Method: data (data) Adds text to the current element. `data' is a string. This should be either a bytestring, or a Unicode string. -- Method: end (tag) Closes the current element. `tag' is the element name. Returns the closed element. -- Method: start (tag, attrs) Opens a new element. `tag' is the element name. `attrs' is a dictionary containing element attributes. Returns the opened element. -- Method: comment (text) Creates a comment with the given `text'. If ‘insert_comments’ is true, this will also add it to the tree. New in version 3.8. -- Method: pi (target, text) Creates a comment with the given `target' name and `text'. If ‘insert_pis’ is true, this will also add it to the tree. New in version 3.8. In addition, a custom *note TreeBuilder: 253. object can provide the following methods: -- Method: doctype (name, pubid, system) Handles a doctype declaration. `name' is the doctype name. `pubid' is the public identifier. `system' is the system identifier. This method does not exist on the default *note TreeBuilder: 253. class. New in version 3.2. -- Method: start_ns (prefix, uri) Is called whenever the parser encounters a new namespace declaration, before the ‘start()’ callback for the opening element that defines it. `prefix' is ‘''’ for the default namespace and the declared namespace prefix name otherwise. `uri' is the namespace URI. New in version 3.8. -- Method: end_ns (prefix) Is called after the ‘end()’ callback of an element that declared a namespace prefix mapping, with the name of the `prefix' that went out of scope. New in version 3.8. -- Class: xml.etree.ElementTree.C14NWriterTarget (write, *, with_comments=False, strip_text=False, rewrite_prefixes=False, qname_aware_tags=None, qname_aware_attrs=None, exclude_attrs=None, exclude_tags=None) A C14N 2.0(1) writer. Arguments are the same as for the *note canonicalize(): 2717. function. This class does not build a tree but translates the callback events directly into a serialised form using the `write' function. New in version 3.8. ---------- Footnotes ---------- (1) https://www.w3.org/TR/xml-c14n2/  File: python.info, Node: XMLParser Objects, Next: XMLPullParser Objects, Prev: TreeBuilder Objects, Up: Reference<3> 5.20.5.23 XMLParser Objects ........................... -- Class: xml.etree.ElementTree.XMLParser (*, target=None, encoding=None) This class is the low-level building block of the module. It uses *note xml.parsers.expat: 138. for efficient, event-based parsing of XML. It can be fed XML data incrementally with the *note feed(): 274e. method, and parsing events are translated to a push API - by invoking callbacks on the `target' object. If `target' is omitted, the standard *note TreeBuilder: 253. is used. If `encoding' (1) is given, the value overrides the encoding specified in the XML file. Changed in version 3.8: Parameters are now *note keyword-only: 2ac. The `html' argument no longer supported. -- Method: close () Finishes feeding data to the parser. Returns the result of calling the ‘close()’ method of the `target' passed during construction; by default, this is the toplevel document element. -- Method: feed (data) Feeds data to the parser. `data' is encoded data. *note XMLParser.feed(): 274e. calls `target'’s ‘start(tag, attrs_dict)’ method for each opening tag, its ‘end(tag)’ method for each closing tag, and data is processed by method ‘data(data)’. For further supported callback methods, see the *note TreeBuilder: 253. class. *note XMLParser.close(): 274f. calls `target'’s method ‘close()’. *note XMLParser: 252. can be used not only for building a tree structure. This is an example of counting the maximum depth of an XML file: >>> from xml.etree.ElementTree import XMLParser >>> class MaxDepth: # The target object of the parser ... maxDepth = 0 ... depth = 0 ... def start(self, tag, attrib): # Called for each opening tag. ... self.depth += 1 ... if self.depth > self.maxDepth: ... self.maxDepth = self.depth ... def end(self, tag): # Called for each closing tag. ... self.depth -= 1 ... def data(self, data): ... pass # We do not need to do anything with data. ... def close(self): # Called when all data has been parsed. ... return self.maxDepth ... >>> target = MaxDepth() >>> parser = XMLParser(target=target) >>> exampleXml = """ ... ... ... ... ... ... ... ... ... ... """ >>> parser.feed(exampleXml) >>> parser.close() 4 ---------- Footnotes ---------- (1) (1) The encoding string included in XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.  File: python.info, Node: XMLPullParser Objects, Next: Exceptions<15>, Prev: XMLParser Objects, Up: Reference<3> 5.20.5.24 XMLPullParser Objects ............................... -- Class: xml.etree.ElementTree.XMLPullParser (events=None) A pull parser suitable for non-blocking applications. Its input-side API is similar to that of *note XMLParser: 252, but instead of pushing calls to a callback target, *note XMLPullParser: 913. collects an internal list of parsing events and lets the user read from it. `events' is a sequence of events to report back. The supported events are the strings ‘"start"’, ‘"end"’, ‘"comment"’, ‘"pi"’, ‘"start-ns"’ and ‘"end-ns"’ (the “ns” events are used to get detailed namespace information). If `events' is omitted, only ‘"end"’ events are reported. -- Method: feed (data) Feed the given bytes data to the parser. -- Method: close () Signal the parser that the data stream is terminated. Unlike *note XMLParser.close(): 274f, this method always returns *note None: 157. Any events not yet retrieved when the parser is closed can still be read with *note read_events(): 2703. -- Method: read_events () Return an iterator over the events which have been encountered in the data fed to the parser. The iterator yields ‘(event, elem)’ pairs, where `event' is a string representing the type of event (e.g. ‘"end"’) and `elem' is the encountered *note Element: ac4. object, or other context value as follows. * ‘start’, ‘end’: the current Element. * ‘comment’, ‘pi’: the current comment / processing instruction * ‘start-ns’: a tuple ‘(prefix, uri)’ naming the declared namespace mapping. * ‘end-ns’: *note None: 157. (this may change in a future version) Events provided in a previous call to *note read_events(): 2703. will not be yielded again. Events are consumed from the internal queue only when they are retrieved from the iterator, so multiple readers iterating in parallel over iterators obtained from *note read_events(): 2703. will have unpredictable results. Note: *note XMLPullParser: 913. only guarantees that it has seen the “>” character of a starting tag when it emits a “start” event, so the attributes are defined, but the contents of the text and tail attributes are undefined at that point. The same applies to the element children; they may or may not be present. If you need a fully populated element, look for “end” events instead. New in version 3.4. Changed in version 3.8: The ‘comment’ and ‘pi’ events were added.  File: python.info, Node: Exceptions<15>, Prev: XMLPullParser Objects, Up: Reference<3> 5.20.5.25 Exceptions .................... -- Class: xml.etree.ElementTree.ParseError XML parse error, raised by the various parsing methods in this module when parsing fails. The string representation of an instance of this exception will contain a user-friendly error message. In addition, it will have the following attributes available: -- Attribute: code A numeric error code from the expat parser. See the documentation of *note xml.parsers.expat: 138. for the list of error codes and their meanings. -- Attribute: position A tuple of `line', `column' numbers, specifying where the error occurred.  File: python.info, Node: xml dom — The Document Object Model API, Next: xml dom minidom — Minimal DOM implementation, Prev: xml etree ElementTree — The ElementTree XML API, Up: Structured Markup Processing Tools 5.20.6 ‘xml.dom’ — The Document Object Model API ------------------------------------------------ `Source code:' Lib/xml/dom/__init__.py(1) __________________________________________________________________ The Document Object Model, or “DOM,” is a cross-language API from the World Wide Web Consortium (W3C) for accessing and modifying XML documents. A DOM implementation presents an XML document as a tree structure, or allows client code to build such a structure from scratch. It then gives access to the structure through a set of objects which provided well-known interfaces. The DOM is extremely useful for random-access applications. SAX only allows you a view of one bit of the document at a time. If you are looking at one SAX element, you have no access to another. If you are looking at a text node, you have no access to a containing element. When you write a SAX application, you need to keep track of your program’s position in the document somewhere in your own code. SAX does not do it for you. Also, if you need to look ahead in the XML document, you are just out of luck. Some applications are simply impossible in an event driven model with no access to a tree. Of course you could build some sort of tree yourself in SAX events, but the DOM allows you to avoid writing that code. The DOM is a standard tree representation for XML data. The Document Object Model is being defined by the W3C in stages, or “levels” in their terminology. The Python mapping of the API is substantially based on the DOM Level 2 recommendation. DOM applications typically start by parsing some XML into a DOM. How this is accomplished is not covered at all by DOM Level 1, and Level 2 provides only limited improvements: There is a ‘DOMImplementation’ object class which provides access to ‘Document’ creation methods, but no way to access an XML reader/parser/Document builder in an implementation-independent way. There is also no well-defined way to access these methods without an existing ‘Document’ object. In Python, each DOM implementation will provide a function *note getDOMImplementation(): 2758. DOM Level 3 adds a Load/Store specification, which defines an interface to the reader, but this is not yet available in the Python standard library. Once you have a DOM document object, you can access the parts of your XML document through its properties and methods. These properties are defined in the DOM specification; this portion of the reference manual describes the interpretation of the specification in Python. The specification provided by the W3C defines the DOM API for Java, ECMAScript, and OMG IDL. The Python mapping defined here is based in large part on the IDL version of the specification, but strict compliance is not required (though implementations are free to support the strict mapping from IDL). See section *note Conformance: 2759. for a detailed discussion of mapping requirements. See also ........ Document Object Model (DOM) Level 2 Specification(2) The W3C recommendation upon which the Python DOM API is based. Document Object Model (DOM) Level 1 Specification(3) The W3C recommendation for the DOM supported by *note xml.dom.minidom: 135. Python Language Mapping Specification(4) This specifies the mapping from OMG IDL to Python. * Menu: * Module Contents: Module Contents<4>. * Objects in the DOM:: * Conformance:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/dom/__init__.py (2) https://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/ (3) https://www.w3.org/TR/REC-DOM-Level-1/ (4) http://www.omg.org/cgi-bin/doc?formal/02-11-05.pdf  File: python.info, Node: Module Contents<4>, Next: Objects in the DOM, Up: xml dom — The Document Object Model API 5.20.6.1 Module Contents ........................ The *note xml.dom: 134. contains the following functions: -- Function: xml.dom.registerDOMImplementation (name, factory) Register the `factory' function with the name `name'. The factory function should return an object which implements the ‘DOMImplementation’ interface. The factory function can return the same object every time, or a new one for each call, as appropriate for the specific implementation (e.g. if that implementation supports some customization). -- Function: xml.dom.getDOMImplementation (name=None, features=()) Return a suitable DOM implementation. The `name' is either well-known, the module name of a DOM implementation, or ‘None’. If it is not ‘None’, imports the corresponding module and returns a ‘DOMImplementation’ object if the import succeeds. If no name is given, and if the environment variable ‘PYTHON_DOM’ is set, this variable is used to find the implementation. If name is not given, this examines the available implementations to find one with the required feature set. If no implementation can be found, raise an *note ImportError: 334. The features list must be a sequence of ‘(feature, version)’ pairs which are passed to the ‘hasFeature()’ method on available ‘DOMImplementation’ objects. Some convenience constants are also provided: -- Data: xml.dom.EMPTY_NAMESPACE The value used to indicate that no namespace is associated with a node in the DOM. This is typically found as the ‘namespaceURI’ of a node, or used as the `namespaceURI' parameter to a namespaces-specific method. -- Data: xml.dom.XML_NAMESPACE The namespace URI associated with the reserved prefix ‘xml’, as defined by Namespaces in XML(1) (section 4). -- Data: xml.dom.XMLNS_NAMESPACE The namespace URI for namespace declarations, as defined by Document Object Model (DOM) Level 2 Core Specification(2) (section 1.1.8). -- Data: xml.dom.XHTML_NAMESPACE The URI of the XHTML namespace as defined by XHTML 1.0: The Extensible HyperText Markup Language(3) (section 3.1.1). In addition, *note xml.dom: 134. contains a base ‘Node’ class and the DOM exception classes. The ‘Node’ class provided by this module does not implement any of the methods or attributes defined by the DOM specification; concrete DOM implementations must provide those. The ‘Node’ class provided as part of this module does provide the constants used for the ‘nodeType’ attribute on concrete ‘Node’ objects; they are located within the class rather than at the module level to conform with the DOM specifications. ---------- Footnotes ---------- (1) https://www.w3.org/TR/REC-xml-names/ (2) https://www.w3.org/TR/DOM-Level-2-Core/core.html (3) https://www.w3.org/TR/xhtml1/  File: python.info, Node: Objects in the DOM, Next: Conformance, Prev: Module Contents<4>, Up: xml dom — The Document Object Model API 5.20.6.2 Objects in the DOM ........................... The definitive documentation for the DOM is the DOM specification from the W3C. Note that DOM attributes may also be manipulated as nodes instead of as simple strings. It is fairly rare that you must do this, however, so this usage is not yet documented. Interface Section Purpose ------------------------------------------------------------------------------------------------------------------- ‘DOMImplementation’ *note DOMImplementation Objects: 2762. Interface to the underlying implementation. ‘Node’ *note Node Objects: 2763. Base interface for most objects in a document. ‘NodeList’ *note NodeList Objects: 2764. Interface for a sequence of nodes. ‘DocumentType’ *note DocumentType Objects: 2765. Information about the declarations needed to process a document. ‘Document’ *note Document Objects: 2766. Object which represents an entire document. ‘Element’ *note Element Objects: 2767. Element nodes in the document hierarchy. ‘Attr’ *note Attr Objects: 2768. Attribute value nodes on element nodes. ‘Comment’ *note Comment Objects: 2769. Representation of comments in the source document. ‘Text’ *note Text and CDATASection Objects: 276a.Nodes containing textual content from the document. ‘ProcessingInstruction’ *note ProcessingInstruction Objects: 276b.Processing instruction representation. An additional section describes the exceptions defined for working with the DOM in Python. * Menu: * DOMImplementation Objects:: * Node Objects:: * NodeList Objects:: * DocumentType Objects:: * Document Objects:: * Element Objects: Element Objects<2>. * Attr Objects:: * NamedNodeMap Objects:: * Comment Objects:: * Text and CDATASection Objects:: * ProcessingInstruction Objects:: * Exceptions: Exceptions<16>.  File: python.info, Node: DOMImplementation Objects, Next: Node Objects, Up: Objects in the DOM 5.20.6.3 DOMImplementation Objects .................................. The ‘DOMImplementation’ interface provides a way for applications to determine the availability of particular features in the DOM they are using. DOM Level 2 added the ability to create new ‘Document’ and ‘DocumentType’ objects using the ‘DOMImplementation’ as well. -- Method: DOMImplementation.hasFeature (feature, version) Return ‘True’ if the feature identified by the pair of strings `feature' and `version' is implemented. -- Method: DOMImplementation.createDocument (namespaceUri, qualifiedName, doctype) Return a new ‘Document’ object (the root of the DOM), with a child ‘Element’ object having the given `namespaceUri' and `qualifiedName'. The `doctype' must be a ‘DocumentType’ object created by *note createDocumentType(): 276f, or ‘None’. In the Python DOM API, the first two arguments can also be ‘None’ in order to indicate that no ‘Element’ child is to be created. -- Method: DOMImplementation.createDocumentType (qualifiedName, publicId, systemId) Return a new ‘DocumentType’ object that encapsulates the given `qualifiedName', `publicId', and `systemId' strings, representing the information contained in an XML document type declaration.  File: python.info, Node: Node Objects, Next: NodeList Objects, Prev: DOMImplementation Objects, Up: Objects in the DOM 5.20.6.4 Node Objects ..................... All of the components of an XML document are subclasses of ‘Node’. -- Attribute: Node.nodeType An integer representing the node type. Symbolic constants for the types are on the ‘Node’ object: ‘ELEMENT_NODE’, ‘ATTRIBUTE_NODE’, ‘TEXT_NODE’, ‘CDATA_SECTION_NODE’, ‘ENTITY_NODE’, ‘PROCESSING_INSTRUCTION_NODE’, ‘COMMENT_NODE’, ‘DOCUMENT_NODE’, ‘DOCUMENT_TYPE_NODE’, ‘NOTATION_NODE’. This is a read-only attribute. -- Attribute: Node.parentNode The parent of the current node, or ‘None’ for the document node. The value is always a ‘Node’ object or ‘None’. For ‘Element’ nodes, this will be the parent element, except for the root element, in which case it will be the ‘Document’ object. For ‘Attr’ nodes, this is always ‘None’. This is a read-only attribute. -- Attribute: Node.attributes A ‘NamedNodeMap’ of attribute objects. Only elements have actual values for this; others provide ‘None’ for this attribute. This is a read-only attribute. -- Attribute: Node.previousSibling The node that immediately precedes this one with the same parent. For instance the element with an end-tag that comes just before the `self' element’s start-tag. Of course, XML documents are made up of more than just elements so the previous sibling could be text, a comment, or something else. If this node is the first child of the parent, this attribute will be ‘None’. This is a read-only attribute. -- Attribute: Node.nextSibling The node that immediately follows this one with the same parent. See also *note previousSibling: 2774. If this is the last child of the parent, this attribute will be ‘None’. This is a read-only attribute. -- Attribute: Node.childNodes A list of nodes contained within this node. This is a read-only attribute. -- Attribute: Node.firstChild The first child of the node, if there are any, or ‘None’. This is a read-only attribute. -- Attribute: Node.lastChild The last child of the node, if there are any, or ‘None’. This is a read-only attribute. -- Attribute: Node.localName The part of the ‘tagName’ following the colon if there is one, else the entire ‘tagName’. The value is a string. -- Attribute: Node.prefix The part of the ‘tagName’ preceding the colon if there is one, else the empty string. The value is a string, or ‘None’. -- Attribute: Node.namespaceURI The namespace associated with the element name. This will be a string or ‘None’. This is a read-only attribute. -- Attribute: Node.nodeName This has a different meaning for each node type; see the DOM specification for details. You can always get the information you would get here from another property such as the ‘tagName’ property for elements or the ‘name’ property for attributes. For all node types, the value of this attribute will be either a string or ‘None’. This is a read-only attribute. -- Attribute: Node.nodeValue This has a different meaning for each node type; see the DOM specification for details. The situation is similar to that with *note nodeName: 277c. The value is a string or ‘None’. -- Method: Node.hasAttributes () Return ‘True’ if the node has any attributes. -- Method: Node.hasChildNodes () Return ‘True’ if the node has any child nodes. -- Method: Node.isSameNode (other) Return ‘True’ if `other' refers to the same node as this node. This is especially useful for DOM implementations which use any sort of proxy architecture (because more than one object can refer to the same node). Note: This is based on a proposed DOM Level 3 API which is still in the “working draft” stage, but this particular interface appears uncontroversial. Changes from the W3C will not necessarily affect this method in the Python DOM interface (though any new W3C API for this would also be supported). -- Method: Node.appendChild (newChild) Add a new child node to this node at the end of the list of children, returning `newChild'. If the node was already in the tree, it is removed first. -- Method: Node.insertBefore (newChild, refChild) Insert a new child node before an existing child. It must be the case that `refChild' is a child of this node; if not, *note ValueError: 1fb. is raised. `newChild' is returned. If `refChild' is ‘None’, it inserts `newChild' at the end of the children’s list. -- Method: Node.removeChild (oldChild) Remove a child node. `oldChild' must be a child of this node; if not, *note ValueError: 1fb. is raised. `oldChild' is returned on success. If `oldChild' will not be used further, its ‘unlink()’ method should be called. -- Method: Node.replaceChild (newChild, oldChild) Replace an existing node with a new node. It must be the case that `oldChild' is a child of this node; if not, *note ValueError: 1fb. is raised. -- Method: Node.normalize () Join adjacent text nodes so that all stretches of text are stored as single ‘Text’ instances. This simplifies processing text from a DOM tree for many applications. -- Method: Node.cloneNode (deep) Clone this node. Setting `deep' means to clone all child nodes as well. This returns the clone.  File: python.info, Node: NodeList Objects, Next: DocumentType Objects, Prev: Node Objects, Up: Objects in the DOM 5.20.6.5 NodeList Objects ......................... A ‘NodeList’ represents a sequence of nodes. These objects are used in two ways in the DOM Core recommendation: an ‘Element’ object provides one as its list of child nodes, and the ‘getElementsByTagName()’ and ‘getElementsByTagNameNS()’ methods of ‘Node’ return objects with this interface to represent query results. The DOM Level 2 recommendation defines one method and one attribute for these objects: -- Method: NodeList.item (i) Return the `i'’th item from the sequence, if there is one, or ‘None’. The index `i' is not allowed to be less than zero or greater than or equal to the length of the sequence. -- Attribute: NodeList.length The number of nodes in the sequence. In addition, the Python DOM interface requires that some additional support is provided to allow ‘NodeList’ objects to be used as Python sequences. All ‘NodeList’ implementations must include support for *note __len__(): dcb. and *note __getitem__(): 27c.; this allows iteration over the ‘NodeList’ in *note for: c30. statements and proper support for the *note len(): 150. built-in function. If a DOM implementation supports modification of the document, the ‘NodeList’ implementation must also support the *note __setitem__(): c62. and *note __delitem__(): c63. methods.  File: python.info, Node: DocumentType Objects, Next: Document Objects, Prev: NodeList Objects, Up: Objects in the DOM 5.20.6.6 DocumentType Objects ............................. Information about the notations and entities declared by a document (including the external subset if the parser uses it and can provide the information) is available from a ‘DocumentType’ object. The ‘DocumentType’ for a document is available from the ‘Document’ object’s ‘doctype’ attribute; if there is no ‘DOCTYPE’ declaration for the document, the document’s ‘doctype’ attribute will be set to ‘None’ instead of an instance of this interface. ‘DocumentType’ is a specialization of ‘Node’, and adds the following attributes: -- Attribute: DocumentType.publicId The public identifier for the external subset of the document type definition. This will be a string or ‘None’. -- Attribute: DocumentType.systemId The system identifier for the external subset of the document type definition. This will be a URI as a string, or ‘None’. -- Attribute: DocumentType.internalSubset A string giving the complete internal subset from the document. This does not include the brackets which enclose the subset. If the document has no internal subset, this should be ‘None’. -- Attribute: DocumentType.name The name of the root element as given in the ‘DOCTYPE’ declaration, if present. -- Attribute: DocumentType.entities This is a ‘NamedNodeMap’ giving the definitions of external entities. For entity names defined more than once, only the first definition is provided (others are ignored as required by the XML recommendation). This may be ‘None’ if the information is not provided by the parser, or if no entities are defined. -- Attribute: DocumentType.notations This is a ‘NamedNodeMap’ giving the definitions of notations. For notation names defined more than once, only the first definition is provided (others are ignored as required by the XML recommendation). This may be ‘None’ if the information is not provided by the parser, or if no notations are defined.  File: python.info, Node: Document Objects, Next: Element Objects<2>, Prev: DocumentType Objects, Up: Objects in the DOM 5.20.6.7 Document Objects ......................... A ‘Document’ represents an entire XML document, including its constituent elements, attributes, processing instructions, comments etc. Remember that it inherits properties from ‘Node’. -- Attribute: Document.documentElement The one and only root element of the document. -- Method: Document.createElement (tagName) Create and return a new element node. The element is not inserted into the document when it is created. You need to explicitly insert it with one of the other methods such as ‘insertBefore()’ or ‘appendChild()’. -- Method: Document.createElementNS (namespaceURI, tagName) Create and return a new element with a namespace. The `tagName' may have a prefix. The element is not inserted into the document when it is created. You need to explicitly insert it with one of the other methods such as ‘insertBefore()’ or ‘appendChild()’. -- Method: Document.createTextNode (data) Create and return a text node containing the data passed as a parameter. As with the other creation methods, this one does not insert the node into the tree. -- Method: Document.createComment (data) Create and return a comment node containing the data passed as a parameter. As with the other creation methods, this one does not insert the node into the tree. -- Method: Document.createProcessingInstruction (target, data) Create and return a processing instruction node containing the `target' and `data' passed as parameters. As with the other creation methods, this one does not insert the node into the tree. -- Method: Document.createAttribute (name) Create and return an attribute node. This method does not associate the attribute node with any particular element. You must use ‘setAttributeNode()’ on the appropriate ‘Element’ object to use the newly created attribute instance. -- Method: Document.createAttributeNS (namespaceURI, qualifiedName) Create and return an attribute node with a namespace. The `tagName' may have a prefix. This method does not associate the attribute node with any particular element. You must use ‘setAttributeNode()’ on the appropriate ‘Element’ object to use the newly created attribute instance. -- Method: Document.getElementsByTagName (tagName) Search for all descendants (direct children, children’s children, etc.) with a particular element type name. -- Method: Document.getElementsByTagNameNS (namespaceURI, localName) Search for all descendants (direct children, children’s children, etc.) with a particular namespace URI and localname. The localname is the part of the namespace after the prefix.  File: python.info, Node: Element Objects<2>, Next: Attr Objects, Prev: Document Objects, Up: Objects in the DOM 5.20.6.8 Element Objects ........................ ‘Element’ is a subclass of ‘Node’, so inherits all the attributes of that class. -- Attribute: Element.tagName The element type name. In a namespace-using document it may have colons in it. The value is a string. -- Method: Element.getElementsByTagName (tagName) Same as equivalent method in the ‘Document’ class. -- Method: Element.getElementsByTagNameNS (namespaceURI, localName) Same as equivalent method in the ‘Document’ class. -- Method: Element.hasAttribute (name) Return ‘True’ if the element has an attribute named by `name'. -- Method: Element.hasAttributeNS (namespaceURI, localName) Return ‘True’ if the element has an attribute named by `namespaceURI' and `localName'. -- Method: Element.getAttribute (name) Return the value of the attribute named by `name' as a string. If no such attribute exists, an empty string is returned, as if the attribute had no value. -- Method: Element.getAttributeNode (attrname) Return the ‘Attr’ node for the attribute named by `attrname'. -- Method: Element.getAttributeNS (namespaceURI, localName) Return the value of the attribute named by `namespaceURI' and `localName' as a string. If no such attribute exists, an empty string is returned, as if the attribute had no value. -- Method: Element.getAttributeNodeNS (namespaceURI, localName) Return an attribute value as a node, given a `namespaceURI' and `localName'. -- Method: Element.removeAttribute (name) Remove an attribute by name. If there is no matching attribute, a *note NotFoundErr: 27a7. is raised. -- Method: Element.removeAttributeNode (oldAttr) Remove and return `oldAttr' from the attribute list, if present. If `oldAttr' is not present, *note NotFoundErr: 27a7. is raised. -- Method: Element.removeAttributeNS (namespaceURI, localName) Remove an attribute by name. Note that it uses a localName, not a qname. No exception is raised if there is no matching attribute. -- Method: Element.setAttribute (name, value) Set an attribute value from a string. -- Method: Element.setAttributeNode (newAttr) Add a new attribute node to the element, replacing an existing attribute if necessary if the ‘name’ attribute matches. If a replacement occurs, the old attribute node will be returned. If `newAttr' is already in use, *note InuseAttributeErr: 27ac. will be raised. -- Method: Element.setAttributeNodeNS (newAttr) Add a new attribute node to the element, replacing an existing attribute if necessary if the ‘namespaceURI’ and ‘localName’ attributes match. If a replacement occurs, the old attribute node will be returned. If `newAttr' is already in use, *note InuseAttributeErr: 27ac. will be raised. -- Method: Element.setAttributeNS (namespaceURI, qname, value) Set an attribute value from a string, given a `namespaceURI' and a `qname'. Note that a qname is the whole attribute name. This is different than above.  File: python.info, Node: Attr Objects, Next: NamedNodeMap Objects, Prev: Element Objects<2>, Up: Objects in the DOM 5.20.6.9 Attr Objects ..................... ‘Attr’ inherits from ‘Node’, so inherits all its attributes. -- Attribute: Attr.name The attribute name. In a namespace-using document it may include a colon. -- Attribute: Attr.localName The part of the name following the colon if there is one, else the entire name. This is a read-only attribute. -- Attribute: Attr.prefix The part of the name preceding the colon if there is one, else the empty string. -- Attribute: Attr.value The text value of the attribute. This is a synonym for the ‘nodeValue’ attribute.  File: python.info, Node: NamedNodeMap Objects, Next: Comment Objects, Prev: Attr Objects, Up: Objects in the DOM 5.20.6.10 NamedNodeMap Objects .............................. ‘NamedNodeMap’ does `not' inherit from ‘Node’. -- Attribute: NamedNodeMap.length The length of the attribute list. -- Method: NamedNodeMap.item (index) Return an attribute with a particular index. The order you get the attributes in is arbitrary but will be consistent for the life of a DOM. Each item is an attribute node. Get its value with the ‘value’ attribute. There are also experimental methods that give this class more mapping behavior. You can use them or you can use the standardized ‘getAttribute*()’ family of methods on the ‘Element’ objects.  File: python.info, Node: Comment Objects, Next: Text and CDATASection Objects, Prev: NamedNodeMap Objects, Up: Objects in the DOM 5.20.6.11 Comment Objects ......................... ‘Comment’ represents a comment in the XML document. It is a subclass of ‘Node’, but cannot have child nodes. -- Attribute: Comment.data The content of the comment as a string. The attribute contains all characters between the leading ‘’, but does not include them.  File: python.info, Node: Text and CDATASection Objects, Next: ProcessingInstruction Objects, Prev: Comment Objects, Up: Objects in the DOM 5.20.6.12 Text and CDATASection Objects ....................................... The ‘Text’ interface represents text in the XML document. If the parser and DOM implementation support the DOM’s XML extension, portions of the text enclosed in CDATA marked sections are stored in ‘CDATASection’ objects. These two interfaces are identical, but provide different values for the ‘nodeType’ attribute. These interfaces extend the ‘Node’ interface. They cannot have child nodes. -- Attribute: Text.data The content of the text node as a string. Note: The use of a ‘CDATASection’ node does not indicate that the node represents a complete CDATA marked section, only that the content of the node was part of a CDATA section. A single CDATA section may be represented by more than one node in the document tree. There is no way to determine whether two adjacent ‘CDATASection’ nodes represent different CDATA marked sections.  File: python.info, Node: ProcessingInstruction Objects, Next: Exceptions<16>, Prev: Text and CDATASection Objects, Up: Objects in the DOM 5.20.6.13 ProcessingInstruction Objects ....................................... Represents a processing instruction in the XML document; this inherits from the ‘Node’ interface and cannot have child nodes. -- Attribute: ProcessingInstruction.target The content of the processing instruction up to the first whitespace character. This is a read-only attribute. -- Attribute: ProcessingInstruction.data The content of the processing instruction following the first whitespace character.  File: python.info, Node: Exceptions<16>, Prev: ProcessingInstruction Objects, Up: Objects in the DOM 5.20.6.14 Exceptions .................... The DOM Level 2 recommendation defines a single exception, *note DOMException: 27c1, and a number of constants that allow applications to determine what sort of error occurred. *note DOMException: 27c1. instances carry a *note code: 1b. attribute that provides the appropriate value for the specific exception. The Python DOM interface provides the constants, but also expands the set of exceptions so that a specific exception exists for each of the exception codes defined by the DOM. The implementations must raise the appropriate specific exception, each of which carries the appropriate value for the *note code: 1b. attribute. -- Exception: xml.dom.DOMException Base exception class used for all specific DOM exceptions. This exception class cannot be directly instantiated. -- Exception: xml.dom.DomstringSizeErr Raised when a specified range of text does not fit into a string. This is not known to be used in the Python DOM implementations, but may be received from DOM implementations not written in Python. -- Exception: xml.dom.HierarchyRequestErr Raised when an attempt is made to insert a node where the node type is not allowed. -- Exception: xml.dom.IndexSizeErr Raised when an index or size parameter to a method is negative or exceeds the allowed values. -- Exception: xml.dom.InuseAttributeErr Raised when an attempt is made to insert an ‘Attr’ node that is already present elsewhere in the document. -- Exception: xml.dom.InvalidAccessErr Raised if a parameter or an operation is not supported on the underlying object. -- Exception: xml.dom.InvalidCharacterErr This exception is raised when a string parameter contains a character that is not permitted in the context it’s being used in by the XML 1.0 recommendation. For example, attempting to create an ‘Element’ node with a space in the element type name will cause this error to be raised. -- Exception: xml.dom.InvalidModificationErr Raised when an attempt is made to modify the type of a node. -- Exception: xml.dom.InvalidStateErr Raised when an attempt is made to use an object that is not defined or is no longer usable. -- Exception: xml.dom.NamespaceErr If an attempt is made to change any object in a way that is not permitted with regard to the Namespaces in XML(1) recommendation, this exception is raised. -- Exception: xml.dom.NotFoundErr Exception when a node does not exist in the referenced context. For example, ‘NamedNodeMap.removeNamedItem()’ will raise this if the node passed in does not exist in the map. -- Exception: xml.dom.NotSupportedErr Raised when the implementation does not support the requested type of object or operation. -- Exception: xml.dom.NoDataAllowedErr This is raised if data is specified for a node which does not support data. -- Exception: xml.dom.NoModificationAllowedErr Raised on attempts to modify an object where modifications are not allowed (such as for read-only nodes). -- Exception: xml.dom.SyntaxErr Raised when an invalid or illegal string is specified. -- Exception: xml.dom.WrongDocumentErr Raised when a node is inserted in a different document than it currently belongs to, and the implementation does not support migrating the node from one document to the other. The exception codes defined in the DOM recommendation map to the exceptions described above according to this table: Constant Exception --------------------------------------------------------------------------------- ‘DOMSTRING_SIZE_ERR’ *note DomstringSizeErr: 27c2. ‘HIERARCHY_REQUEST_ERR’ *note HierarchyRequestErr: 27c3. ‘INDEX_SIZE_ERR’ *note IndexSizeErr: 27c4. ‘INUSE_ATTRIBUTE_ERR’ *note InuseAttributeErr: 27ac. ‘INVALID_ACCESS_ERR’ *note InvalidAccessErr: 27c5. ‘INVALID_CHARACTER_ERR’ *note InvalidCharacterErr: 27c6. ‘INVALID_MODIFICATION_ERR’ *note InvalidModificationErr: 27c7. ‘INVALID_STATE_ERR’ *note InvalidStateErr: 27c8. ‘NAMESPACE_ERR’ *note NamespaceErr: 27c9. ‘NOT_FOUND_ERR’ *note NotFoundErr: 27a7. ‘NOT_SUPPORTED_ERR’ *note NotSupportedErr: 27ca. ‘NO_DATA_ALLOWED_ERR’ *note NoDataAllowedErr: 27cb. ‘NO_MODIFICATION_ALLOWED_ERR’ *note NoModificationAllowedErr: 27cc. ‘SYNTAX_ERR’ *note SyntaxErr: 27cd. ‘WRONG_DOCUMENT_ERR’ *note WrongDocumentErr: 27ce. ---------- Footnotes ---------- (1) https://www.w3.org/TR/REC-xml-names/  File: python.info, Node: Conformance, Prev: Objects in the DOM, Up: xml dom — The Document Object Model API 5.20.6.15 Conformance ..................... This section describes the conformance requirements and relationships between the Python DOM API, the W3C DOM recommendations, and the OMG IDL mapping for Python. * Menu: * Type Mapping:: * Accessor Methods::  File: python.info, Node: Type Mapping, Next: Accessor Methods, Up: Conformance 5.20.6.16 Type Mapping ...................... The IDL types used in the DOM specification are mapped to Python types according to the following table. IDL Type Python Type ----------------------------------------------------------------------- ‘boolean’ ‘bool’ or ‘int’ ‘int’ ‘int’ ‘long int’ ‘int’ ‘unsigned int’ ‘int’ ‘DOMString’ ‘str’ or ‘bytes’ ‘null’ ‘None’  File: python.info, Node: Accessor Methods, Prev: Type Mapping, Up: Conformance 5.20.6.17 Accessor Methods .......................... The mapping from OMG IDL to Python defines accessor functions for IDL ‘attribute’ declarations in much the way the Java mapping does. Mapping the IDL declarations readonly attribute string someValue; attribute string anotherValue; yields three accessor functions: a “get” method for ‘someValue’ (‘_get_someValue()’), and “get” and “set” methods for ‘anotherValue’ (‘_get_anotherValue()’ and ‘_set_anotherValue()’). The mapping, in particular, does not require that the IDL attributes are accessible as normal Python attributes: ‘object.someValue’ is `not' required to work, and may raise an *note AttributeError: 39b. The Python DOM API, however, `does' require that normal attribute access work. This means that the typical surrogates generated by Python IDL compilers are not likely to work, and wrapper objects may be needed on the client if the DOM objects are accessed via CORBA. While this does require some additional consideration for CORBA DOM clients, the implementers with experience using DOM over CORBA from Python do not consider this a problem. Attributes that are declared ‘readonly’ may not restrict write access in all DOM implementations. In the Python DOM API, accessor functions are not required. If provided, they should take the form defined by the Python IDL mapping, but these methods are considered unnecessary since the attributes are accessible directly from Python. “Set” accessors should never be provided for ‘readonly’ attributes. The IDL definitions do not fully embody the requirements of the W3C DOM API, such as the notion of certain objects, such as the return value of ‘getElementsByTagName()’, being “live”. The Python DOM API does not require implementations to enforce such requirements.  File: python.info, Node: xml dom minidom — Minimal DOM implementation, Next: xml dom pulldom — Support for building partial DOM trees, Prev: xml dom — The Document Object Model API, Up: Structured Markup Processing Tools 5.20.7 ‘xml.dom.minidom’ — Minimal DOM implementation ----------------------------------------------------- `Source code:' Lib/xml/dom/minidom.py(1) __________________________________________________________________ *note xml.dom.minidom: 135. is a minimal implementation of the Document Object Model interface, with an API similar to that in other languages. It is intended to be simpler than the full DOM and also significantly smaller. Users who are not already proficient with the DOM should consider using the *note xml.etree.ElementTree: 137. module for their XML processing instead. Warning: The *note xml.dom.minidom: 135. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. DOM applications typically start by parsing some XML into a DOM. With *note xml.dom.minidom: 135, this is done through the parse functions: from xml.dom.minidom import parse, parseString dom1 = parse('c:\\temp\\mydata.xml') # parse an XML file by name datasource = open('c:\\temp\\mydata.xml') dom2 = parse(datasource) # parse an open file dom3 = parseString('Some data some more data') The *note parse(): 27d6. function can take either a filename or an open file object. -- Function: xml.dom.minidom.parse (filename_or_file, parser=None, bufsize=None) Return a ‘Document’ from the given input. `filename_or_file' may be either a file name, or a file-like object. `parser', if given, must be a SAX2 parser object. This function will change the document handler of the parser and activate namespace support; other parser configuration (like setting an entity resolver) must have been done in advance. If you have XML in a string, you can use the *note parseString(): 27d7. function instead: -- Function: xml.dom.minidom.parseString (string, parser=None) Return a ‘Document’ that represents the `string'. This method creates an *note io.StringIO: 82d. object for the string and passes that on to *note parse(): 27d6. Both functions return a ‘Document’ object representing the content of the document. What the *note parse(): 27d6. and *note parseString(): 27d7. functions do is connect an XML parser with a “DOM builder” that can accept parse events from any SAX parser and convert them into a DOM tree. The name of the functions are perhaps misleading, but are easy to grasp when learning the interfaces. The parsing of the document will be completed before these functions return; it’s simply that these functions do not provide a parser implementation themselves. You can also create a ‘Document’ by calling a method on a “DOM Implementation” object. You can get this object either by calling the ‘getDOMImplementation()’ function in the *note xml.dom: 134. package or the *note xml.dom.minidom: 135. module. Once you have a ‘Document’, you can add child nodes to it to populate the DOM: from xml.dom.minidom import getDOMImplementation impl = getDOMImplementation() newdoc = impl.createDocument(None, "some_tag", None) top_element = newdoc.documentElement text = newdoc.createTextNode('Some textual content.') top_element.appendChild(text) Once you have a DOM document object, you can access the parts of your XML document through its properties and methods. These properties are defined in the DOM specification. The main property of the document object is the ‘documentElement’ property. It gives you the main element in the XML document: the one that holds all others. Here is an example program: dom3 = parseString("Some data") assert dom3.documentElement.tagName == "myxml" When you are finished with a DOM tree, you may optionally call the ‘unlink()’ method to encourage early cleanup of the now-unneeded objects. ‘unlink()’ is an *note xml.dom.minidom: 135.-specific extension to the DOM API that renders the node and its descendants are essentially useless. Otherwise, Python’s garbage collector will eventually take care of the objects in the tree. See also ........ Document Object Model (DOM) Level 1 Specification(2) The W3C recommendation for the DOM supported by *note xml.dom.minidom: 135. * Menu: * DOM Objects:: * DOM Example:: * minidom and the DOM standard:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/dom/minidom.py (2) https://www.w3.org/TR/REC-DOM-Level-1/  File: python.info, Node: DOM Objects, Next: DOM Example, Up: xml dom minidom — Minimal DOM implementation 5.20.7.1 DOM Objects .................... The definition of the DOM API for Python is given as part of the *note xml.dom: 134. module documentation. This section lists the differences between the API and *note xml.dom.minidom: 135. -- Method: Node.unlink () Break internal references within the DOM so that it will be garbage collected on versions of Python without cyclic GC. Even when cyclic GC is available, using this can make large amounts of memory available sooner, so calling this on DOM objects as soon as they are no longer needed is good practice. This only needs to be called on the ‘Document’ object, but may be called on child nodes to discard children of that node. You can avoid calling this method explicitly by using the *note with: 6e9. statement. The following code will automatically unlink `dom' when the ‘with’ block is exited: with xml.dom.minidom.parse(datasource) as dom: ... # Work with dom. -- Method: Node.writexml (writer, indent="", addindent="", newl="") Write XML to the writer object. The writer receives texts but not bytes as input, it should have a ‘write()’ method which matches that of the file object interface. The `indent' parameter is the indentation of the current node. The `addindent' parameter is the incremental indentation to use for subnodes of the current one. The `newl' parameter specifies the string to use to terminate newlines. For the ‘Document’ node, an additional keyword argument `encoding' can be used to specify the encoding field of the XML header. Changed in version 3.8: The *note writexml(): 27db. method now preserves the attribute order specified by the user. -- Method: Node.toxml (encoding=None) Return a string or byte string containing the XML represented by the DOM node. With an explicit `encoding' (1) argument, the result is a byte string in the specified encoding. With no `encoding' argument, the result is a Unicode string, and the XML declaration in the resulting string does not specify an encoding. Encoding this string in an encoding other than UTF-8 is likely incorrect, since UTF-8 is the default encoding of XML. Changed in version 3.8: The *note toxml(): 27dc. method now preserves the attribute order specified by the user. -- Method: Node.toprettyxml (indent="\t", newl="\n", encoding=None) Return a pretty-printed version of the document. `indent' specifies the indentation string and defaults to a tabulator; `newl' specifies the string emitted at the end of each line and defaults to ‘\n’. The `encoding' argument behaves like the corresponding argument of *note toxml(): 27dc. Changed in version 3.8: The *note toprettyxml(): 27dd. method now preserves the attribute order specified by the user. ---------- Footnotes ---------- (1) (1) The encoding name included in the XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not valid in an XML document’s declaration, even though Python accepts it as an encoding name. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.  File: python.info, Node: DOM Example, Next: minidom and the DOM standard, Prev: DOM Objects, Up: xml dom minidom — Minimal DOM implementation 5.20.7.2 DOM Example .................... This example program is a fairly realistic example of a simple program. In this particular case, we do not take much advantage of the flexibility of the DOM. import xml.dom.minidom document = """\ Demo slideshow Slide title This is a demo Of a program for processing slides Another demo slide It is important To have more than one slide """ dom = xml.dom.minidom.parseString(document) def getText(nodelist): rc = [] for node in nodelist: if node.nodeType == node.TEXT_NODE: rc.append(node.data) return ''.join(rc) def handleSlideshow(slideshow): print("") handleSlideshowTitle(slideshow.getElementsByTagName("title")[0]) slides = slideshow.getElementsByTagName("slide") handleToc(slides) handleSlides(slides) print("") def handleSlides(slides): for slide in slides: handleSlide(slide) def handleSlide(slide): handleSlideTitle(slide.getElementsByTagName("title")[0]) handlePoints(slide.getElementsByTagName("point")) def handleSlideshowTitle(title): print("%s" % getText(title.childNodes)) def handleSlideTitle(title): print("

%s

" % getText(title.childNodes)) def handlePoints(points): print("
    ") for point in points: handlePoint(point) print("
") def handlePoint(point): print("
  • %s
    • " % getText(point.childNodes)) def handleToc(slides): for slide in slides: title = slide.getElementsByTagName("title")[0] print("

    %s

    " % getText(title.childNodes)) handleSlideshow(dom)  File: python.info, Node: minidom and the DOM standard, Prev: DOM Example, Up: xml dom minidom — Minimal DOM implementation 5.20.7.3 minidom and the DOM standard ..................................... The *note xml.dom.minidom: 135. module is essentially a DOM 1.0-compatible DOM with some DOM 2 features (primarily namespace features). Usage of the DOM interface in Python is straight-forward. The following mapping rules apply: * Interfaces are accessed through instance objects. Applications should not instantiate the classes themselves; they should use the creator functions available on the ‘Document’ object. Derived interfaces support all operations (and attributes) from the base interfaces, plus any new operations. * Operations are used as methods. Since the DOM uses only *note in: 7a3. parameters, the arguments are passed in normal order (from left to right). There are no optional arguments. ‘void’ operations return ‘None’. * IDL attributes map to instance attributes. For compatibility with the OMG IDL language mapping for Python, an attribute ‘foo’ can also be accessed through accessor methods ‘_get_foo()’ and ‘_set_foo()’. ‘readonly’ attributes must not be changed; this is not enforced at runtime. * The types ‘short int’, ‘unsigned int’, ‘unsigned long long’, and ‘boolean’ all map to Python integer objects. * The type ‘DOMString’ maps to Python strings. *note xml.dom.minidom: 135. supports either bytes or strings, but will normally produce strings. Values of type ‘DOMString’ may also be ‘None’ where allowed to have the IDL ‘null’ value by the DOM specification from the W3C. * ‘const’ declarations map to variables in their respective scope (e.g. ‘xml.dom.minidom.Node.PROCESSING_INSTRUCTION_NODE’); they must not be changed. * ‘DOMException’ is currently not supported in *note xml.dom.minidom: 135. Instead, *note xml.dom.minidom: 135. uses standard Python exceptions such as *note TypeError: 192. and *note AttributeError: 39b. * ‘NodeList’ objects are implemented using Python’s built-in list type. These objects provide the interface defined in the DOM specification, but with earlier versions of Python they do not support the official API. They are, however, much more “Pythonic” than the interface defined in the W3C recommendations. The following interfaces have no implementation in *note xml.dom.minidom: 135.: * ‘DOMTimeStamp’ * ‘EntityReference’ Most of these reflect information in the XML document that is not of general utility to most DOM users.  File: python.info, Node: xml dom pulldom — Support for building partial DOM trees, Next: xml sax — Support for SAX2 parsers, Prev: xml dom minidom — Minimal DOM implementation, Up: Structured Markup Processing Tools 5.20.8 ‘xml.dom.pulldom’ — Support for building partial DOM trees ----------------------------------------------------------------- `Source code:' Lib/xml/dom/pulldom.py(1) __________________________________________________________________ The *note xml.dom.pulldom: 136. module provides a “pull parser” which can also be asked to produce DOM-accessible fragments of the document where necessary. The basic concept involves pulling “events” from a stream of incoming XML and processing them. In contrast to SAX which also employs an event-driven processing model together with callbacks, the user of a pull parser is responsible for explicitly pulling events from the stream, looping over those events until either processing is finished or an error condition occurs. Warning: The *note xml.dom.pulldom: 136. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. Changed in version 3.7.1: The SAX parser no longer processes general external entities by default to increase security by default. To enable processing of external entities, pass a custom parser instance in: from xml.dom.pulldom import parse from xml.sax import make_parser from xml.sax.handler import feature_external_ges parser = make_parser() parser.setFeature(feature_external_ges, True) parse(filename, parser=parser) Example: from xml.dom import pulldom doc = pulldom.parse('sales_items.xml') for event, node in doc: if event == pulldom.START_ELEMENT and node.tagName == 'item': if int(node.getAttribute('price')) > 50: doc.expandNode(node) print(node.toxml()) ‘event’ is a constant and can be one of: * ‘START_ELEMENT’ * ‘END_ELEMENT’ * ‘COMMENT’ * ‘START_DOCUMENT’ * ‘END_DOCUMENT’ * ‘CHARACTERS’ * ‘PROCESSING_INSTRUCTION’ * ‘IGNORABLE_WHITESPACE’ ‘node’ is an object of type ‘xml.dom.minidom.Document’, ‘xml.dom.minidom.Element’ or ‘xml.dom.minidom.Text’. Since the document is treated as a “flat” stream of events, the document “tree” is implicitly traversed and the desired elements are found regardless of their depth in the tree. In other words, one does not need to consider hierarchical issues such as recursive searching of the document nodes, although if the context of elements were important, one would either need to maintain some context-related state (i.e. remembering where one is in the document at any given point) or to make use of the *note DOMEventStream.expandNode(): 27e4. method and switch to DOM-related processing. -- Class: xml.dom.pulldom.PullDom (documentFactory=None) Subclass of *note xml.sax.handler.ContentHandler: 27e6. -- Class: xml.dom.pulldom.SAX2DOM (documentFactory=None) Subclass of *note xml.sax.handler.ContentHandler: 27e6. -- Function: xml.dom.pulldom.parse (stream_or_string, parser=None, bufsize=None) Return a *note DOMEventStream: 27d. from the given input. `stream_or_string' may be either a file name, or a file-like object. `parser', if given, must be an *note XMLReader: 27e9. object. This function will change the document handler of the parser and activate namespace support; other parser configuration (like setting an entity resolver) must have been done in advance. If you have XML in a string, you can use the *note parseString(): 27ea. function instead: -- Function: xml.dom.pulldom.parseString (string, parser=None) Return a *note DOMEventStream: 27d. that represents the (Unicode) `string'. -- Data: xml.dom.pulldom.default_bufsize Default value for the `bufsize' parameter to *note parse(): 27e8. The value of this variable can be changed before calling *note parse(): 27e8. and the new value will take effect. * Menu: * DOMEventStream Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/dom/pulldom.py  File: python.info, Node: DOMEventStream Objects, Up: xml dom pulldom — Support for building partial DOM trees 5.20.8.1 DOMEventStream Objects ............................... -- Class: xml.dom.pulldom.DOMEventStream (stream, parser, bufsize) Deprecated since version 3.8: Support for *note sequence protocol: 27c. is deprecated. -- Method: getEvent () Return a tuple containing `event' and the current `node' as ‘xml.dom.minidom.Document’ if event equals ‘START_DOCUMENT’, ‘xml.dom.minidom.Element’ if event equals ‘START_ELEMENT’ or ‘END_ELEMENT’ or ‘xml.dom.minidom.Text’ if event equals ‘CHARACTERS’. The current node does not contain information about its children, unless *note expandNode(): 27e4. is called. -- Method: expandNode (node) Expands all children of `node' into `node'. Example: from xml.dom import pulldom xml = 'Foo

    Some text

    and more

    ' doc = pulldom.parseString(xml) for event, node in doc: if event == pulldom.START_ELEMENT and node.tagName == 'p': # Following statement only prints '

    ' print(node.toxml()) doc.expandNode(node) # Following statement prints node with all its children '

    Some text

    and more

    ' print(node.toxml()) -- Method: reset ()  File: python.info, Node: xml sax — Support for SAX2 parsers, Next: xml sax handler — Base classes for SAX handlers, Prev: xml dom pulldom — Support for building partial DOM trees, Up: Structured Markup Processing Tools 5.20.9 ‘xml.sax’ — Support for SAX2 parsers ------------------------------------------- `Source code:' Lib/xml/sax/__init__.py(1) __________________________________________________________________ The *note xml.sax: 13b. package provides a number of modules which implement the Simple API for XML (SAX) interface for Python. The package itself provides the SAX exceptions and the convenience functions which will be most used by users of the SAX API. Warning: The *note xml.sax: 13b. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. Changed in version 3.7.1: The SAX parser no longer processes general external entities by default to increase security. Before, the parser created network connections to fetch remote files or loaded local files from the file system for DTD and entities. The feature can be enabled again with method *note setFeature(): 27f2. on the parser object and argument *note feature_external_ges: 27f3. The convenience functions are: -- Function: xml.sax.make_parser (parser_list=[]) Create and return a SAX *note XMLReader: 27e9. object. The first parser found will be used. If `parser_list' is provided, it must be an iterable of strings which name modules that have a function named ‘create_parser()’. Modules listed in `parser_list' will be used before modules in the default list of parsers. Changed in version 3.8: The `parser_list' argument can be any iterable, not just a list. -- Function: xml.sax.parse (filename_or_stream, handler, error_handler=handler.ErrorHandler()) Create a SAX parser and use it to parse a document. The document, passed in as `filename_or_stream', can be a filename or a file object. The `handler' parameter needs to be a SAX *note ContentHandler: 27e6. instance. If `error_handler' is given, it must be a SAX *note ErrorHandler: 27f6. instance; if omitted, *note SAXParseException: 27f7. will be raised on all errors. There is no return value; all work must be done by the `handler' passed in. -- Function: xml.sax.parseString (string, handler, error_handler=handler.ErrorHandler()) Similar to *note parse(): 27f5, but parses from a buffer `string' received as a parameter. `string' must be a *note str: 330. instance or a *note bytes-like object: 5e8. Changed in version 3.5: Added support of *note str: 330. instances. A typical SAX application uses three kinds of objects: readers, handlers and input sources. “Reader” in this context is another term for parser, i.e. some piece of code that reads the bytes or characters from the input source, and produces a sequence of events. The events then get distributed to the handler objects, i.e. the reader invokes a method on the handler. A SAX application must therefore obtain a reader object, create or open the input sources, create the handlers, and connect these objects all together. As the final step of preparation, the reader is called to parse the input. During parsing, methods on the handler objects are called based on structural and syntactic events from the input data. For these objects, only the interfaces are relevant; they are normally not instantiated by the application itself. Since Python does not have an explicit notion of interface, they are formally introduced as classes, but applications may use implementations which do not inherit from the provided classes. The *note InputSource: 792, *note Locator: 27f8, ‘Attributes’, ‘AttributesNS’, and *note XMLReader: 27e9. interfaces are defined in the module *note xml.sax.xmlreader: 13e. The handler interfaces are defined in *note xml.sax.handler: 13c. For convenience, *note InputSource: 792. (which is often instantiated directly) and the handler classes are also available from *note xml.sax: 13b. These interfaces are described below. In addition to these classes, *note xml.sax: 13b. provides the following exception classes. -- Exception: xml.sax.SAXException (msg, exception=None) Encapsulate an XML error or warning. This class can contain basic error or warning information from either the XML parser or the application: it can be subclassed to provide additional functionality or to add localization. Note that although the handlers defined in the *note ErrorHandler: 27f6. interface receive instances of this exception, it is not required to actually raise the exception — it is also useful as a container for information. When instantiated, `msg' should be a human-readable description of the error. The optional `exception' parameter, if given, should be ‘None’ or an exception that was caught by the parsing code and is being passed along as information. This is the base class for the other SAX exception classes. -- Exception: xml.sax.SAXParseException (msg, exception, locator) Subclass of *note SAXException: 27f9. raised on parse errors. Instances of this class are passed to the methods of the SAX *note ErrorHandler: 27f6. interface to provide information about the parse error. This class supports the SAX *note Locator: 27f8. interface as well as the *note SAXException: 27f9. interface. -- Exception: xml.sax.SAXNotRecognizedException (msg, exception=None) Subclass of *note SAXException: 27f9. raised when a SAX *note XMLReader: 27e9. is confronted with an unrecognized feature or property. SAX applications and extensions may use this class for similar purposes. -- Exception: xml.sax.SAXNotSupportedException (msg, exception=None) Subclass of *note SAXException: 27f9. raised when a SAX *note XMLReader: 27e9. is asked to enable a feature that is not supported, or to set a property to a value that the implementation does not support. SAX applications and extensions may use this class for similar purposes. See also ........ SAX: The Simple API for XML(2) This site is the focal point for the definition of the SAX API. It provides a Java implementation and online documentation. Links to implementations and historical information are also available. Module *note xml.sax.handler: 13c. Definitions of the interfaces for application-provided objects. Module *note xml.sax.saxutils: 13d. Convenience functions for use in SAX applications. Module *note xml.sax.xmlreader: 13e. Definitions of the interfaces for parser-provided objects. * Menu: * SAXException Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/sax/__init__.py (2) http://www.saxproject.org/  File: python.info, Node: SAXException Objects, Up: xml sax — Support for SAX2 parsers 5.20.9.1 SAXException Objects ............................. The *note SAXException: 27f9. exception class supports the following methods: -- Method: SAXException.getMessage () Return a human-readable message describing the error condition. -- Method: SAXException.getException () Return an encapsulated exception object, or ‘None’.  File: python.info, Node: xml sax handler — Base classes for SAX handlers, Next: xml sax saxutils — SAX Utilities, Prev: xml sax — Support for SAX2 parsers, Up: Structured Markup Processing Tools 5.20.10 ‘xml.sax.handler’ — Base classes for SAX handlers --------------------------------------------------------- `Source code:' Lib/xml/sax/handler.py(1) __________________________________________________________________ The SAX API defines four kinds of handlers: content handlers, DTD handlers, error handlers, and entity resolvers. Applications normally only need to implement those interfaces whose events they are interested in; they can implement the interfaces in a single object or in multiple objects. Handler implementations should inherit from the base classes provided in the module *note xml.sax.handler: 13c, so that all methods get default implementations. -- Class: xml.sax.handler.ContentHandler This is the main callback interface in SAX, and the one most important to applications. The order of events in this interface mirrors the order of the information in the document. -- Class: xml.sax.handler.DTDHandler Handle DTD events. This interface specifies only those DTD events required for basic parsing (unparsed entities and attributes). -- Class: xml.sax.handler.EntityResolver Basic interface for resolving entities. If you create an object implementing this interface, then register the object with your Parser, the parser will call the method in your object to resolve all external entities. -- Class: xml.sax.handler.ErrorHandler Interface used by the parser to present error and warning messages to the application. The methods of this object control whether errors are immediately converted to exceptions or are handled in some other way. In addition to these classes, *note xml.sax.handler: 13c. provides symbolic constants for the feature and property names. -- Data: xml.sax.handler.feature_namespaces value: ‘"http://xml.org/sax/features/namespaces"’ true: Perform Namespace processing. false: Optionally do not perform Namespace processing (implies namespace-prefixes; default). access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.feature_namespace_prefixes value: ‘"http://xml.org/sax/features/namespace-prefixes"’ true: Report the original prefixed names and attributes used for Namespace declarations. false: Do not report attributes used for Namespace declarations, and optionally do not report original prefixed names (default). access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.feature_string_interning value: ‘"http://xml.org/sax/features/string-interning"’ true: All element names, prefixes, attribute names, Namespace URIs, and local names are interned using the built-in intern function. false: Names are not necessarily interned, although they may be (default). access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.feature_validation value: ‘"http://xml.org/sax/features/validation"’ true: Report all validation errors (implies external-general-entities and external-parameter-entities). false: Do not report validation errors. access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.feature_external_ges value: ‘"http://xml.org/sax/features/external-general-entities"’ true: Include all external general (text) entities. false: Do not include external general entities. access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.feature_external_pes value: ‘"http://xml.org/sax/features/external-parameter-entities"’ true: Include all external parameter entities, including the external DTD subset. false: Do not include any external parameter entities, even the external DTD subset. access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.all_features List of all features. -- Data: xml.sax.handler.property_lexical_handler value: ‘"http://xml.org/sax/properties/lexical-handler"’ data type: xml.sax.sax2lib.LexicalHandler (not supported in Python 2) description: An optional extension handler for lexical events like comments. access: read/write -- Data: xml.sax.handler.property_declaration_handler value: ‘"http://xml.org/sax/properties/declaration-handler"’ data type: xml.sax.sax2lib.DeclHandler (not supported in Python 2) description: An optional extension handler for DTD-related events other than notations and unparsed entities. access: read/write -- Data: xml.sax.handler.property_dom_node value: ‘"http://xml.org/sax/properties/dom-node"’ data type: org.w3c.dom.Node (not supported in Python 2) description: When parsing, the current DOM node being visited if this is a DOM iterator; when not parsing, the root DOM node for iteration. access: (parsing) read-only; (not parsing) read/write -- Data: xml.sax.handler.property_xml_string value: ‘"http://xml.org/sax/properties/xml-string"’ data type: String description: The literal string of characters that was the source for the current event. access: read-only -- Data: xml.sax.handler.all_properties List of all known property names. * Menu: * ContentHandler Objects:: * DTDHandler Objects:: * EntityResolver Objects:: * ErrorHandler Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/sax/handler.py  File: python.info, Node: ContentHandler Objects, Next: DTDHandler Objects, Up: xml sax handler — Base classes for SAX handlers 5.20.10.1 ContentHandler Objects ................................ Users are expected to subclass *note ContentHandler: 27e6. to support their application. The following methods are called by the parser on the appropriate events in the input document: -- Method: ContentHandler.setDocumentLocator (locator) Called by the parser to give the application a locator for locating the origin of document events. SAX parsers are strongly encouraged (though not absolutely required) to supply a locator: if it does so, it must supply the locator to the application by invoking this method before invoking any of the other methods in the DocumentHandler interface. The locator allows the application to determine the end position of any document-related event, even if the parser is not reporting an error. Typically, the application will use this information for reporting its own errors (such as character content that does not match an application’s business rules). The information returned by the locator is probably not sufficient for use with a search engine. Note that the locator will return correct information only during the invocation of the events in this interface. The application should not attempt to use it at any other time. -- Method: ContentHandler.startDocument () Receive notification of the beginning of a document. The SAX parser will invoke this method only once, before any other methods in this interface or in DTDHandler (except for *note setDocumentLocator(): 2811.). -- Method: ContentHandler.endDocument () Receive notification of the end of a document. The SAX parser will invoke this method only once, and it will be the last method invoked during the parse. The parser shall not invoke this method until it has either abandoned parsing (because of an unrecoverable error) or reached the end of input. -- Method: ContentHandler.startPrefixMapping (prefix, uri) Begin the scope of a prefix-URI Namespace mapping. The information from this event is not necessary for normal Namespace processing: the SAX XML reader will automatically replace prefixes for element and attribute names when the ‘feature_namespaces’ feature is enabled (the default). There are cases, however, when applications need to use prefixes in character data or in attribute values, where they cannot safely be expanded automatically; the *note startPrefixMapping(): 2814. and *note endPrefixMapping(): 2815. events supply the information to the application to expand prefixes in those contexts itself, if necessary. Note that *note startPrefixMapping(): 2814. and *note endPrefixMapping(): 2815. events are not guaranteed to be properly nested relative to each-other: all *note startPrefixMapping(): 2814. events will occur before the corresponding *note startElement(): 2816. event, and all *note endPrefixMapping(): 2815. events will occur after the corresponding *note endElement(): 2817. event, but their order is not guaranteed. -- Method: ContentHandler.endPrefixMapping (prefix) End the scope of a prefix-URI mapping. See *note startPrefixMapping(): 2814. for details. This event will always occur after the corresponding *note endElement(): 2817. event, but the order of *note endPrefixMapping(): 2815. events is not otherwise guaranteed. -- Method: ContentHandler.startElement (name, attrs) Signals the start of an element in non-namespace mode. The `name' parameter contains the raw XML 1.0 name of the element type as a string and the `attrs' parameter holds an object of the ‘Attributes’ interface (see *note The Attributes Interface: 2818.) containing the attributes of the element. The object passed as `attrs' may be re-used by the parser; holding on to a reference to it is not a reliable way to keep a copy of the attributes. To keep a copy of the attributes, use the *note copy(): 26. method of the `attrs' object. -- Method: ContentHandler.endElement (name) Signals the end of an element in non-namespace mode. The `name' parameter contains the name of the element type, just as with the *note startElement(): 2816. event. -- Method: ContentHandler.startElementNS (name, qname, attrs) Signals the start of an element in namespace mode. The `name' parameter contains the name of the element type as a ‘(uri, localname)’ tuple, the `qname' parameter contains the raw XML 1.0 name used in the source document, and the `attrs' parameter holds an instance of the ‘AttributesNS’ interface (see *note The AttributesNS Interface: 281a.) containing the attributes of the element. If no namespace is associated with the element, the `uri' component of `name' will be ‘None’. The object passed as `attrs' may be re-used by the parser; holding on to a reference to it is not a reliable way to keep a copy of the attributes. To keep a copy of the attributes, use the *note copy(): 26. method of the `attrs' object. Parsers may set the `qname' parameter to ‘None’, unless the ‘feature_namespace_prefixes’ feature is activated. -- Method: ContentHandler.endElementNS (name, qname) Signals the end of an element in namespace mode. The `name' parameter contains the name of the element type, just as with the *note startElementNS(): 2819. method, likewise the `qname' parameter. -- Method: ContentHandler.characters (content) Receive notification of character data. The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity so that the Locator provides useful information. `content' may be a string or bytes instance; the ‘expat’ reader module always produces strings. Note: The earlier SAX 1 interface provided by the Python XML Special Interest Group used a more Java-like interface for this method. Since most parsers used from Python did not take advantage of the older interface, the simpler signature was chosen to replace it. To convert old code to the new interface, use `content' instead of slicing content with the old `offset' and `length' parameters. -- Method: ContentHandler.ignorableWhitespace (whitespace) Receive notification of ignorable whitespace in element content. Validating Parsers must use this method to report each chunk of ignorable whitespace (see the W3C XML 1.0 recommendation, section 2.10): non-validating parsers may also use this method if they are capable of parsing and using content models. SAX parsers may return all contiguous whitespace in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information. -- Method: ContentHandler.processingInstruction (target, data) Receive notification of a processing instruction. The Parser will invoke this method once for each processing instruction found: note that processing instructions may occur before or after the main document element. A SAX parser should never report an XML declaration (XML 1.0, section 2.8) or a text declaration (XML 1.0, section 4.3.1) using this method. -- Method: ContentHandler.skippedEntity (name) Receive notification of a skipped entity. The Parser will invoke this method once for each entity skipped. Non-validating processors may skip entities if they have not seen the declarations (because, for example, the entity was declared in an external DTD subset). All processors may skip external entities, depending on the values of the ‘feature_external_ges’ and the ‘feature_external_pes’ properties.  File: python.info, Node: DTDHandler Objects, Next: EntityResolver Objects, Prev: ContentHandler Objects, Up: xml sax handler — Base classes for SAX handlers 5.20.10.2 DTDHandler Objects ............................ *note DTDHandler: 2802. instances provide the following methods: -- Method: DTDHandler.notationDecl (name, publicId, systemId) Handle a notation declaration event. -- Method: DTDHandler.unparsedEntityDecl (name, publicId, systemId, ndata) Handle an unparsed entity declaration event.  File: python.info, Node: EntityResolver Objects, Next: ErrorHandler Objects, Prev: DTDHandler Objects, Up: xml sax handler — Base classes for SAX handlers 5.20.10.3 EntityResolver Objects ................................ -- Method: EntityResolver.resolveEntity (publicId, systemId) Resolve the system identifier of an entity and return either the system identifier to read from as a string, or an InputSource to read from. The default implementation returns `systemId'.  File: python.info, Node: ErrorHandler Objects, Prev: EntityResolver Objects, Up: xml sax handler — Base classes for SAX handlers 5.20.10.4 ErrorHandler Objects .............................. Objects with this interface are used to receive error and warning information from the *note XMLReader: 27e9. If you create an object that implements this interface, then register the object with your *note XMLReader: 27e9, the parser will call the methods in your object to report all warnings and errors. There are three levels of errors available: warnings, (possibly) recoverable errors, and unrecoverable errors. All methods take a ‘SAXParseException’ as the only parameter. Errors and warnings may be converted to an exception by raising the passed-in exception object. -- Method: ErrorHandler.error (exception) Called when the parser encounters a recoverable error. If this method does not raise an exception, parsing may continue, but further document information should not be expected by the application. Allowing the parser to continue may allow additional errors to be discovered in the input document. -- Method: ErrorHandler.fatalError (exception) Called when the parser encounters an error it cannot recover from; parsing is expected to terminate when this method returns. -- Method: ErrorHandler.warning (exception) Called when the parser presents minor warning information to the application. Parsing is expected to continue when this method returns, and document information will continue to be passed to the application. Raising an exception in this method will cause parsing to end.  File: python.info, Node: xml sax saxutils — SAX Utilities, Next: xml sax xmlreader — Interface for XML parsers, Prev: xml sax handler — Base classes for SAX handlers, Up: Structured Markup Processing Tools 5.20.11 ‘xml.sax.saxutils’ — SAX Utilities ------------------------------------------ `Source code:' Lib/xml/sax/saxutils.py(1) __________________________________________________________________ The module *note xml.sax.saxutils: 13d. contains a number of classes and functions that are commonly useful when creating SAX applications, either in direct use, or as base classes. -- Function: xml.sax.saxutils.escape (data, entities={}) Escape ‘'&'’, ‘'<'’, and ‘'>'’ in a string of data. You can escape other strings of data by passing a dictionary as the optional `entities' parameter. The keys and values must all be strings; each key will be replaced with its corresponding value. The characters ‘'&'’, ‘'<'’ and ‘'>'’ are always escaped, even if `entities' is provided. -- Function: xml.sax.saxutils.unescape (data, entities={}) Unescape ‘'&'’, ‘'<'’, and ‘'>'’ in a string of data. You can unescape other strings of data by passing a dictionary as the optional `entities' parameter. The keys and values must all be strings; each key will be replaced with its corresponding value. ‘'&'’, ‘'<'’, and ‘'>'’ are always unescaped, even if `entities' is provided. -- Function: xml.sax.saxutils.quoteattr (data, entities={}) Similar to *note escape(): 282e, but also prepares `data' to be used as an attribute value. The return value is a quoted version of `data' with any additional required replacements. *note quoteattr(): 2830. will select a quote character based on the content of `data', attempting to avoid encoding any quote characters in the string. If both single- and double-quote characters are already in `data', the double-quote characters will be encoded and `data' will be wrapped in double-quotes. The resulting string can be used directly as an attribute value: >>> print("" % quoteattr("ab ' cd \" ef")) This function is useful when generating attribute values for HTML or any SGML using the reference concrete syntax. -- Class: xml.sax.saxutils.XMLGenerator (out=None, encoding='iso-8859-1', short_empty_elements=False) This class implements the *note ContentHandler: 27e6. interface by writing SAX events back into an XML document. In other words, using an *note XMLGenerator: 2831. as the content handler will reproduce the original document being parsed. `out' should be a file-like object which will default to `sys.stdout'. `encoding' is the encoding of the output stream which defaults to ‘'iso-8859-1'’. `short_empty_elements' controls the formatting of elements that contain no content: if ‘False’ (the default) they are emitted as a pair of start/end tags, if set to ‘True’ they are emitted as a single self-closed tag. New in version 3.2: The `short_empty_elements' parameter. -- Class: xml.sax.saxutils.XMLFilterBase (base) This class is designed to sit between an *note XMLReader: 27e9. and the client application’s event handlers. By default, it does nothing but pass requests up to the reader and events on to the handlers unmodified, but subclasses can override specific methods to modify the event stream or the configuration requests as they pass through. -- Function: xml.sax.saxutils.prepare_input_source (source, base='') This function takes an input source and an optional base URL and returns a fully resolved *note InputSource: 792. object ready for reading. The input source can be given as a string, a file-like object, or an *note InputSource: 792. object; parsers will use this function to implement the polymorphic `source' argument to their ‘parse()’ method. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/sax/saxutils.py  File: python.info, Node: xml sax xmlreader — Interface for XML parsers, Next: xml parsers expat — Fast XML parsing using Expat, Prev: xml sax saxutils — SAX Utilities, Up: Structured Markup Processing Tools 5.20.12 ‘xml.sax.xmlreader’ — Interface for XML parsers ------------------------------------------------------- `Source code:' Lib/xml/sax/xmlreader.py(1) __________________________________________________________________ SAX parsers implement the *note XMLReader: 27e9. interface. They are implemented in a Python module, which must provide a function ‘create_parser()’. This function is invoked by *note xml.sax.make_parser(): 27f4. with no arguments to create a new parser object. -- Class: xml.sax.xmlreader.XMLReader Base class which can be inherited by SAX parsers. -- Class: xml.sax.xmlreader.IncrementalParser In some cases, it is desirable not to parse an input source at once, but to feed chunks of the document as they get available. Note that the reader will normally not read the entire file, but read it in chunks as well; still ‘parse()’ won’t return until the entire document is processed. So these interfaces should be used if the blocking behaviour of ‘parse()’ is not desirable. When the parser is instantiated it is ready to begin accepting data from the feed method immediately. After parsing has been finished with a call to close the reset method must be called to make the parser ready to accept new data, either from feed or using the parse method. Note that these methods must `not' be called during parsing, that is, after parse has been called and before it returns. By default, the class also implements the parse method of the XMLReader interface using the feed, close and reset methods of the IncrementalParser interface as a convenience to SAX 2.0 driver writers. -- Class: xml.sax.xmlreader.Locator Interface for associating a SAX event with a document location. A locator object will return valid results only during calls to DocumentHandler methods; at any other time, the results are unpredictable. If information is not available, methods may return ‘None’. -- Class: xml.sax.xmlreader.InputSource (system_id=None) Encapsulation of the information needed by the *note XMLReader: 27e9. to read entities. This class may include information about the public identifier, system identifier, byte stream (possibly with character encoding information) and/or the character stream of an entity. Applications will create objects of this class for use in the *note XMLReader.parse(): 2837. method and for returning from EntityResolver.resolveEntity. An *note InputSource: 792. belongs to the application, the *note XMLReader: 27e9. is not allowed to modify *note InputSource: 792. objects passed to it from the application, although it may make copies and modify those. -- Class: xml.sax.xmlreader.AttributesImpl (attrs) This is an implementation of the ‘Attributes’ interface (see section *note The Attributes Interface: 2818.). This is a dictionary-like object which represents the element attributes in a ‘startElement()’ call. In addition to the most useful dictionary operations, it supports a number of other methods as described by the interface. Objects of this class should be instantiated by readers; `attrs' must be a dictionary-like object containing a mapping from attribute names to attribute values. -- Class: xml.sax.xmlreader.AttributesNSImpl (attrs, qnames) Namespace-aware variant of *note AttributesImpl: 2838, which will be passed to ‘startElementNS()’. It is derived from *note AttributesImpl: 2838, but understands attribute names as two-tuples of `namespaceURI' and `localname'. In addition, it provides a number of methods expecting qualified names as they appear in the original document. This class implements the ‘AttributesNS’ interface (see section *note The AttributesNS Interface: 281a.). * Menu: * XMLReader Objects:: * IncrementalParser Objects:: * Locator Objects:: * InputSource Objects:: * The Attributes Interface:: * The AttributesNS Interface:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xml/sax/xmlreader.py  File: python.info, Node: XMLReader Objects, Next: IncrementalParser Objects, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.1 XMLReader Objects ........................... The *note XMLReader: 27e9. interface supports the following methods: -- Method: XMLReader.parse (source) Process an input source, producing SAX events. The `source' object can be a system identifier (a string identifying the input source – typically a file name or a URL), a *note pathlib.Path: 201. or *note path-like: 36a. object, or an *note InputSource: 792. object. When *note parse(): 2837. returns, the input is completely processed, and the parser object can be discarded or reset. Changed in version 3.5: Added support of character streams. Changed in version 3.8: Added support of path-like objects. -- Method: XMLReader.getContentHandler () Return the current *note ContentHandler: 27e6. -- Method: XMLReader.setContentHandler (handler) Set the current *note ContentHandler: 27e6. If no *note ContentHandler: 27e6. is set, content events will be discarded. -- Method: XMLReader.getDTDHandler () Return the current *note DTDHandler: 2802. -- Method: XMLReader.setDTDHandler (handler) Set the current *note DTDHandler: 2802. If no *note DTDHandler: 2802. is set, DTD events will be discarded. -- Method: XMLReader.getEntityResolver () Return the current *note EntityResolver: 2803. -- Method: XMLReader.setEntityResolver (handler) Set the current *note EntityResolver: 2803. If no *note EntityResolver: 2803. is set, attempts to resolve an external entity will result in opening the system identifier for the entity, and fail if it is not available. -- Method: XMLReader.getErrorHandler () Return the current *note ErrorHandler: 27f6. -- Method: XMLReader.setErrorHandler (handler) Set the current error handler. If no *note ErrorHandler: 27f6. is set, errors will be raised as exceptions, and warnings will be printed. -- Method: XMLReader.setLocale (locale) Allow an application to set the locale for errors and warnings. SAX parsers are not required to provide localization for errors and warnings; if they cannot support the requested locale, however, they must raise a SAX exception. Applications may request a locale change in the middle of a parse. -- Method: XMLReader.getFeature (featurename) Return the current setting for feature `featurename'. If the feature is not recognized, ‘SAXNotRecognizedException’ is raised. The well-known featurenames are listed in the module *note xml.sax.handler: 13c. -- Method: XMLReader.setFeature (featurename, value) Set the `featurename' to `value'. If the feature is not recognized, ‘SAXNotRecognizedException’ is raised. If the feature or its setting is not supported by the parser, `SAXNotSupportedException' is raised. -- Method: XMLReader.getProperty (propertyname) Return the current setting for property `propertyname'. If the property is not recognized, a ‘SAXNotRecognizedException’ is raised. The well-known propertynames are listed in the module *note xml.sax.handler: 13c. -- Method: XMLReader.setProperty (propertyname, value) Set the `propertyname' to `value'. If the property is not recognized, ‘SAXNotRecognizedException’ is raised. If the property or its setting is not supported by the parser, `SAXNotSupportedException' is raised.  File: python.info, Node: IncrementalParser Objects, Next: Locator Objects, Prev: XMLReader Objects, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.2 IncrementalParser Objects ................................... Instances of *note IncrementalParser: 2836. offer the following additional methods: -- Method: IncrementalParser.feed (data) Process a chunk of `data'. -- Method: IncrementalParser.close () Assume the end of the document. That will check well-formedness conditions that can be checked only at the end, invoke handlers, and may clean up resources allocated during parsing. -- Method: IncrementalParser.reset () This method is called after close has been called to reset the parser so that it is ready to parse new documents. The results of calling parse or feed after close without calling reset are undefined.  File: python.info, Node: Locator Objects, Next: InputSource Objects, Prev: IncrementalParser Objects, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.3 Locator Objects ......................... Instances of *note Locator: 27f8. provide these methods: -- Method: Locator.getColumnNumber () Return the column number where the current event begins. -- Method: Locator.getLineNumber () Return the line number where the current event begins. -- Method: Locator.getPublicId () Return the public identifier for the current event. -- Method: Locator.getSystemId () Return the system identifier for the current event.  File: python.info, Node: InputSource Objects, Next: The Attributes Interface, Prev: Locator Objects, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.4 InputSource Objects ............................. -- Method: InputSource.setPublicId (id) Sets the public identifier of this *note InputSource: 792. -- Method: InputSource.getPublicId () Returns the public identifier of this *note InputSource: 792. -- Method: InputSource.setSystemId (id) Sets the system identifier of this *note InputSource: 792. -- Method: InputSource.getSystemId () Returns the system identifier of this *note InputSource: 792. -- Method: InputSource.setEncoding (encoding) Sets the character encoding of this *note InputSource: 792. The encoding must be a string acceptable for an XML encoding declaration (see section 4.3.3 of the XML recommendation). The encoding attribute of the *note InputSource: 792. is ignored if the *note InputSource: 792. also contains a character stream. -- Method: InputSource.getEncoding () Get the character encoding of this InputSource. -- Method: InputSource.setByteStream (bytefile) Set the byte stream (a *note binary file: 1966.) for this input source. The SAX parser will ignore this if there is also a character stream specified, but it will use a byte stream in preference to opening a URI connection itself. If the application knows the character encoding of the byte stream, it should set it with the setEncoding method. -- Method: InputSource.getByteStream () Get the byte stream for this input source. The getEncoding method will return the character encoding for this byte stream, or ‘None’ if unknown. -- Method: InputSource.setCharacterStream (charfile) Set the character stream (a *note text file: f3a.) for this input source. If there is a character stream specified, the SAX parser will ignore any byte stream and will not attempt to open a URI connection to the system identifier. -- Method: InputSource.getCharacterStream () Get the character stream for this input source.  File: python.info, Node: The Attributes Interface, Next: The AttributesNS Interface, Prev: InputSource Objects, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.5 The ‘Attributes’ Interface .................................... ‘Attributes’ objects implement a portion of the *note mapping protocol: b39, including the methods ‘copy()’, ‘get()’, *note __contains__(): d28, ‘items()’, ‘keys()’, and ‘values()’. The following methods are also provided: -- Method: Attributes.getLength () Return the number of attributes. -- Method: Attributes.getNames () Return the names of the attributes. -- Method: Attributes.getType (name) Returns the type of the attribute `name', which is normally ‘'CDATA'’. -- Method: Attributes.getValue (name) Return the value of attribute `name'.  File: python.info, Node: The AttributesNS Interface, Prev: The Attributes Interface, Up: xml sax xmlreader — Interface for XML parsers 5.20.12.6 The ‘AttributesNS’ Interface ...................................... This interface is a subtype of the ‘Attributes’ interface (see section *note The Attributes Interface: 2818.). All methods supported by that interface are also available on ‘AttributesNS’ objects. The following methods are also available: -- Method: AttributesNS.getValueByQName (name) Return the value for a qualified name. -- Method: AttributesNS.getNameByQName (name) Return the ‘(namespace, localname)’ pair for a qualified `name'. -- Method: AttributesNS.getQNameByName (name) Return the qualified name for a ‘(namespace, localname)’ pair. -- Method: AttributesNS.getQNames () Return the qualified names of all attributes.  File: python.info, Node: xml parsers expat — Fast XML parsing using Expat, Prev: xml sax xmlreader — Interface for XML parsers, Up: Structured Markup Processing Tools 5.20.13 ‘xml.parsers.expat’ — Fast XML parsing using Expat ---------------------------------------------------------- __________________________________________________________________ Warning: The ‘pyexpat’ module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. The *note xml.parsers.expat: 138. module is a Python interface to the Expat non-validating XML parser. The module provides a single extension type, ‘xmlparser’, that represents the current state of an XML parser. After an ‘xmlparser’ object has been created, various attributes of the object can be set to handler functions. When an XML document is then fed to the parser, the handler functions are called for the character data and markup in the XML document. This module uses the ‘pyexpat’ module to provide access to the Expat parser. Direct use of the ‘pyexpat’ module is deprecated. This module provides one exception and one type object: -- Exception: xml.parsers.expat.ExpatError The exception raised when Expat reports an error. See section *note ExpatError Exceptions: 286b. for more information on interpreting Expat errors. -- Exception: xml.parsers.expat.error Alias for *note ExpatError: c0d. -- Data: xml.parsers.expat.XMLParserType The type of the return values from the *note ParserCreate(): 286e. function. The *note xml.parsers.expat: 138. module contains two functions: -- Function: xml.parsers.expat.ErrorString (errno) Returns an explanatory string for a given error number `errno'. -- Function: xml.parsers.expat.ParserCreate (encoding=None, namespace_separator=None) Creates and returns a new ‘xmlparser’ object. `encoding', if specified, must be a string naming the encoding used by the XML data. Expat doesn’t support as many encodings as Python does, and its repertoire of encodings can’t be extended; it supports UTF-8, UTF-16, ISO-8859-1 (Latin1), and ASCII. If `encoding' (1) is given it will override the implicit or explicit encoding of the document. Expat can optionally do XML namespace processing for you, enabled by providing a value for `namespace_separator'. The value must be a one-character string; a *note ValueError: 1fb. will be raised if the string has an illegal length (‘None’ is considered the same as omission). When namespace processing is enabled, element type names and attribute names that belong to a namespace will be expanded. The element name passed to the element handlers ‘StartElementHandler’ and ‘EndElementHandler’ will be the concatenation of the namespace URI, the namespace separator character, and the local part of the name. If the namespace separator is a zero byte (‘chr(0)’) then the namespace URI and the local part will be concatenated without any separator. For example, if `namespace_separator' is set to a space character (‘' '’) and the following document is parsed: ‘StartElementHandler’ will receive the following strings for each element: http://default-namespace.org/ root http://www.python.org/ns/ elem1 elem2 Due to limitations in the ‘Expat’ library used by ‘pyexpat’, the ‘xmlparser’ instance returned can only be used to parse a single XML document. Call ‘ParserCreate’ for each document to provide unique parser instances. See also ........ The Expat XML Parser(2) Home page of the Expat project. * Menu: * XMLParser Objects: XMLParser Objects<2>. * ExpatError Exceptions:: * Example: Example<12>. * Content Model Descriptions:: * Expat error constants:: ---------- Footnotes ---------- (1) (1) The encoding string included in XML output should conform to the appropriate standards. For example, “UTF-8” is valid, but “UTF8” is not. See ‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and ‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’. (2) http://www.libexpat.org/  File: python.info, Node: XMLParser Objects<2>, Next: ExpatError Exceptions, Up: xml parsers expat — Fast XML parsing using Expat 5.20.13.1 XMLParser Objects ........................... ‘xmlparser’ objects have the following methods: -- Method: xmlparser.Parse (data[, isfinal]) Parses the contents of the string `data', calling the appropriate handler functions to process the parsed data. `isfinal' must be true on the final call to this method; it allows the parsing of a single file in fragments, not the submission of multiple files. `data' can be the empty string at any time. -- Method: xmlparser.ParseFile (file) Parse XML data reading from the object `file'. `file' only needs to provide the ‘read(nbytes)’ method, returning the empty string when there’s no more data. -- Method: xmlparser.SetBase (base) Sets the base to be used for resolving relative URIs in system identifiers in declarations. Resolving relative identifiers is left to the application: this value will be passed through as the `base' argument to the *note ExternalEntityRefHandler(): 2875, *note NotationDeclHandler(): 2876, and *note UnparsedEntityDeclHandler(): 2877. functions. -- Method: xmlparser.GetBase () Returns a string containing the base set by a previous call to *note SetBase(): 2874, or ‘None’ if *note SetBase(): 2874. hasn’t been called. -- Method: xmlparser.GetInputContext () Returns the input data that generated the current event as a string. The data is in the encoding of the entity which contains the text. When called while an event handler is not active, the return value is ‘None’. -- Method: xmlparser.ExternalEntityParserCreate (context[, encoding]) Create a “child” parser which can be used to parse an external parsed entity referred to by content parsed by the parent parser. The `context' parameter should be the string passed to the *note ExternalEntityRefHandler(): 2875. handler function, described below. The child parser is created with the *note ordered_attributes: 287b. and *note specified_attributes: 287c. set to the values of this parser. -- Method: xmlparser.SetParamEntityParsing (flag) Control parsing of parameter entities (including the external DTD subset). Possible `flag' values are ‘XML_PARAM_ENTITY_PARSING_NEVER’, ‘XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE’ and ‘XML_PARAM_ENTITY_PARSING_ALWAYS’. Return true if setting the flag was successful. -- Method: xmlparser.UseForeignDTD ([flag]) Calling this with a true value for `flag' (the default) will cause Expat to call the *note ExternalEntityRefHandler: 2875. with *note None: 157. for all arguments to allow an alternate DTD to be loaded. If the document does not contain a document type declaration, the *note ExternalEntityRefHandler: 2875. will still be called, but the *note StartDoctypeDeclHandler: 287f. and *note EndDoctypeDeclHandler: 2880. will not be called. Passing a false value for `flag' will cancel a previous call that passed a true value, but otherwise has no effect. This method can only be called before the *note Parse(): 2872. or *note ParseFile(): 2873. methods are called; calling it after either of those have been called causes *note ExpatError: c0d. to be raised with the *note code: 1b. attribute set to ‘errors.codes[errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING]’. ‘xmlparser’ objects have the following attributes: -- Attribute: xmlparser.buffer_size The size of the buffer used when *note buffer_text: 2882. is true. A new buffer size can be set by assigning a new integer value to this attribute. When the size is changed, the buffer will be flushed. -- Attribute: xmlparser.buffer_text Setting this to true causes the ‘xmlparser’ object to buffer textual content returned by Expat to avoid multiple calls to the *note CharacterDataHandler(): 2883. callback whenever possible. This can improve performance substantially since Expat normally breaks character data into chunks at every line ending. This attribute is false by default, and may be changed at any time. -- Attribute: xmlparser.buffer_used If *note buffer_text: 2882. is enabled, the number of bytes stored in the buffer. These bytes represent UTF-8 encoded text. This attribute has no meaningful interpretation when *note buffer_text: 2882. is false. -- Attribute: xmlparser.ordered_attributes Setting this attribute to a non-zero integer causes the attributes to be reported as a list rather than a dictionary. The attributes are presented in the order found in the document text. For each attribute, two list entries are presented: the attribute name and the attribute value. (Older versions of this module also used this format.) By default, this attribute is false; it may be changed at any time. -- Attribute: xmlparser.specified_attributes If set to a non-zero integer, the parser will report only those attributes which were specified in the document instance and not those which were derived from attribute declarations. Applications which set this need to be especially careful to use what additional information is available from the declarations as needed to comply with the standards for the behavior of XML processors. By default, this attribute is false; it may be changed at any time. The following attributes contain values relating to the most recent error encountered by an ‘xmlparser’ object, and will only have correct values once a call to ‘Parse()’ or ‘ParseFile()’ has raised an *note xml.parsers.expat.ExpatError: c0d. exception. -- Attribute: xmlparser.ErrorByteIndex Byte index at which an error occurred. -- Attribute: xmlparser.ErrorCode Numeric code specifying the problem. This value can be passed to the *note ErrorString(): 286f. function, or compared to one of the constants defined in the ‘errors’ object. -- Attribute: xmlparser.ErrorColumnNumber Column number at which an error occurred. -- Attribute: xmlparser.ErrorLineNumber Line number at which an error occurred. The following attributes contain values relating to the current parse location in an ‘xmlparser’ object. During a callback reporting a parse event they indicate the location of the first of the sequence of characters that generated the event. When called outside of a callback, the position indicated will be just past the last parse event (regardless of whether there was an associated callback). -- Attribute: xmlparser.CurrentByteIndex Current byte index in the parser input. -- Attribute: xmlparser.CurrentColumnNumber Current column number in the parser input. -- Attribute: xmlparser.CurrentLineNumber Current line number in the parser input. Here is the list of handlers that can be set. To set a handler on an ‘xmlparser’ object `o', use ‘o.handlername = func’. `handlername' must be taken from the following list, and `func' must be a callable object accepting the correct number of arguments. The arguments are all strings, unless otherwise stated. -- Method: xmlparser.XmlDeclHandler (version, encoding, standalone) Called when the XML declaration is parsed. The XML declaration is the (optional) declaration of the applicable version of the XML recommendation, the encoding of the document text, and an optional “standalone” declaration. `version' and `encoding' will be strings, and `standalone' will be ‘1’ if the document is declared standalone, ‘0’ if it is declared not to be standalone, or ‘-1’ if the standalone clause was omitted. This is only available with Expat version 1.95.0 or newer. -- Method: xmlparser.StartDoctypeDeclHandler (doctypeName, systemId, publicId, has_internal_subset) Called when Expat begins parsing the document type declaration (‘'’. -- Method: xmlparser.StartCdataSectionHandler () Called at the start of a CDATA section. This and *note EndCdataSectionHandler: 2893. are needed to be able to identify the syntactical start and end for CDATA sections. -- Method: xmlparser.EndCdataSectionHandler () Called at the end of a CDATA section. -- Method: xmlparser.DefaultHandler (data) Called for any characters in the XML document for which no applicable handler has been specified. This means characters that are part of a construct which could be reported, but for which no handler has been supplied. -- Method: xmlparser.DefaultHandlerExpand (data) This is the same as the *note DefaultHandler(): 2898, but doesn’t inhibit expansion of internal entities. The entity reference will not be passed to the default handler. -- Method: xmlparser.NotStandaloneHandler () Called if the XML document hasn’t been declared as being a standalone document. This happens when there is an external subset or a reference to a parameter entity, but the XML declaration does not set standalone to ‘yes’ in an XML declaration. If this handler returns ‘0’, then the parser will raise an ‘XML_ERROR_NOT_STANDALONE’ error. If this handler is not set, no exception is raised by the parser for this condition. -- Method: xmlparser.ExternalEntityRefHandler (context, base, systemId, publicId) Called for references to external entities. `base' is the current base, as set by a previous call to *note SetBase(): 2874. The public and system identifiers, `systemId' and `publicId', are strings if given; if the public identifier is not given, `publicId' will be ‘None’. The `context' value is opaque and should only be used as described below. For external entities to be parsed, this handler must be implemented. It is responsible for creating the sub-parser using ‘ExternalEntityParserCreate(context)’, initializing it with the appropriate callbacks, and parsing the entity. This handler should return an integer; if it returns ‘0’, the parser will raise an ‘XML_ERROR_EXTERNAL_ENTITY_HANDLING’ error, otherwise parsing will continue. If this handler is not provided, external entities are reported by the *note DefaultHandler: 2898. callback, if provided.  File: python.info, Node: ExpatError Exceptions, Next: Example<12>, Prev: XMLParser Objects<2>, Up: xml parsers expat — Fast XML parsing using Expat 5.20.13.2 ExpatError Exceptions ............................... *note ExpatError: c0d. exceptions have a number of interesting attributes: -- Attribute: ExpatError.code Expat’s internal error number for the specific error. The *note errors.messages: 289d. dictionary maps these error numbers to Expat’s error messages. For example: from xml.parsers.expat import ParserCreate, ExpatError, errors p = ParserCreate() try: p.Parse(some_xml_document) except ExpatError as err: print("Error:", errors.messages[err.code]) The *note errors: 139. module also provides error message constants and a dictionary *note codes: 289e. mapping these messages back to the error codes, see below. -- Attribute: ExpatError.lineno Line number on which the error was detected. The first line is numbered ‘1’. -- Attribute: ExpatError.offset Character offset into the line where the error occurred. The first column is numbered ‘0’.  File: python.info, Node: Example<12>, Next: Content Model Descriptions, Prev: ExpatError Exceptions, Up: xml parsers expat — Fast XML parsing using Expat 5.20.13.3 Example ................. The following program defines three handlers that just print out their arguments. import xml.parsers.expat # 3 handler functions def start_element(name, attrs): print('Start element:', name, attrs) def end_element(name): print('End element:', name) def char_data(data): print('Character data:', repr(data)) p = xml.parsers.expat.ParserCreate() p.StartElementHandler = start_element p.EndElementHandler = end_element p.CharacterDataHandler = char_data p.Parse(""" Text goes here More text """, 1) The output from this program is: Start element: parent {'id': 'top'} Start element: child1 {'name': 'paul'} Character data: 'Text goes here' End element: child1 Character data: '\n' Start element: child2 {'name': 'fred'} Character data: 'More text' End element: child2 Character data: '\n' End element: parent  File: python.info, Node: Content Model Descriptions, Next: Expat error constants, Prev: Example<12>, Up: xml parsers expat — Fast XML parsing using Expat 5.20.13.4 Content Model Descriptions .................................... Content models are described using nested tuples. Each tuple contains four values: the type, the quantifier, the name, and a tuple of children. Children are simply additional content model descriptions. The values of the first two fields are constants defined in the *note xml.parsers.expat.model: 13a. module. These constants can be collected in two groups: the model type group and the quantifier group. The constants in the model type group are: -- Data: xml.parsers.expat.model.XML_CTYPE_ANY The element named by the model name was declared to have a content model of ‘ANY’. -- Data: xml.parsers.expat.model.XML_CTYPE_CHOICE The named element allows a choice from a number of options; this is used for content models such as ‘(A | B | C)’. -- Data: xml.parsers.expat.model.XML_CTYPE_EMPTY Elements which are declared to be ‘EMPTY’ have this model type. -- Data: xml.parsers.expat.model.XML_CTYPE_MIXED -- Data: xml.parsers.expat.model.XML_CTYPE_NAME -- Data: xml.parsers.expat.model.XML_CTYPE_SEQ Models which represent a series of models which follow one after the other are indicated with this model type. This is used for models such as ‘(A, B, C)’. The constants in the quantifier group are: -- Data: xml.parsers.expat.model.XML_CQUANT_NONE No modifier is given, so it can appear exactly once, as for ‘A’. -- Data: xml.parsers.expat.model.XML_CQUANT_OPT The model is optional: it can appear once or not at all, as for ‘A?’. -- Data: xml.parsers.expat.model.XML_CQUANT_PLUS The model must occur one or more times (like ‘A+’). -- Data: xml.parsers.expat.model.XML_CQUANT_REP The model must occur zero or more times, as for ‘A*’.  File: python.info, Node: Expat error constants, Prev: Content Model Descriptions, Up: xml parsers expat — Fast XML parsing using Expat 5.20.13.5 Expat error constants ............................... The following constants are provided in the *note xml.parsers.expat.errors: 139. module. These constants are useful in interpreting some of the attributes of the ‘ExpatError’ exception objects raised when an error has occurred. Since for backwards compatibility reasons, the constants’ value is the error `message' and not the numeric error `code', you do this by comparing its *note code: 1b. attribute with ‘errors.codes[errors.XML_ERROR_`CONSTANT_NAME']’. The ‘errors’ module has the following attributes: -- Data: xml.parsers.expat.errors.codes A dictionary mapping string descriptions to their error codes. New in version 3.2. -- Data: xml.parsers.expat.errors.messages A dictionary mapping numeric error codes to their string descriptions. New in version 3.2. -- Data: xml.parsers.expat.errors.XML_ERROR_ASYNC_ENTITY -- Data: xml.parsers.expat.errors.XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF An entity reference in an attribute value referred to an external entity instead of an internal entity. -- Data: xml.parsers.expat.errors.XML_ERROR_BAD_CHAR_REF A character reference referred to a character which is illegal in XML (for example, character ‘0’, or ‘‘�’’). -- Data: xml.parsers.expat.errors.XML_ERROR_BINARY_ENTITY_REF An entity reference referred to an entity which was declared with a notation, so cannot be parsed. -- Data: xml.parsers.expat.errors.XML_ERROR_DUPLICATE_ATTRIBUTE An attribute was used more than once in a start tag. -- Data: xml.parsers.expat.errors.XML_ERROR_INCORRECT_ENCODING -- Data: xml.parsers.expat.errors.XML_ERROR_INVALID_TOKEN Raised when an input byte could not properly be assigned to a character; for example, a NUL byte (value ‘0’) in a UTF-8 input stream. -- Data: xml.parsers.expat.errors.XML_ERROR_JUNK_AFTER_DOC_ELEMENT Something other than whitespace occurred after the document element. -- Data: xml.parsers.expat.errors.XML_ERROR_MISPLACED_XML_PI An XML declaration was found somewhere other than the start of the input data. -- Data: xml.parsers.expat.errors.XML_ERROR_NO_ELEMENTS The document contains no elements (XML requires all documents to contain exactly one top-level element).. -- Data: xml.parsers.expat.errors.XML_ERROR_NO_MEMORY Expat was not able to allocate memory internally. -- Data: xml.parsers.expat.errors.XML_ERROR_PARAM_ENTITY_REF A parameter entity reference was found where it was not allowed. -- Data: xml.parsers.expat.errors.XML_ERROR_PARTIAL_CHAR An incomplete character was found in the input. -- Data: xml.parsers.expat.errors.XML_ERROR_RECURSIVE_ENTITY_REF An entity reference contained another reference to the same entity; possibly via a different name, and possibly indirectly. -- Data: xml.parsers.expat.errors.XML_ERROR_SYNTAX Some unspecified syntax error was encountered. -- Data: xml.parsers.expat.errors.XML_ERROR_TAG_MISMATCH An end tag did not match the innermost open start tag. -- Data: xml.parsers.expat.errors.XML_ERROR_UNCLOSED_TOKEN Some token (such as a start tag) was not closed before the end of the stream or the next token was encountered. -- Data: xml.parsers.expat.errors.XML_ERROR_UNDEFINED_ENTITY A reference was made to an entity which was not defined. -- Data: xml.parsers.expat.errors.XML_ERROR_UNKNOWN_ENCODING The document encoding is not supported by Expat. -- Data: xml.parsers.expat.errors.XML_ERROR_UNCLOSED_CDATA_SECTION A CDATA marked section was not closed. -- Data: xml.parsers.expat.errors.XML_ERROR_EXTERNAL_ENTITY_HANDLING -- Data: xml.parsers.expat.errors.XML_ERROR_NOT_STANDALONE The parser determined that the document was not “standalone” though it declared itself to be in the XML declaration, and the ‘NotStandaloneHandler’ was set and returned ‘0’. -- Data: xml.parsers.expat.errors.XML_ERROR_UNEXPECTED_STATE -- Data: xml.parsers.expat.errors.XML_ERROR_ENTITY_DECLARED_IN_PE -- Data: xml.parsers.expat.errors.XML_ERROR_FEATURE_REQUIRES_XML_DTD An operation was requested that requires DTD support to be compiled in, but Expat was configured without DTD support. This should never be reported by a standard build of the *note xml.parsers.expat: 138. module. -- Data: xml.parsers.expat.errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING A behavioral change was requested after parsing started that can only be changed before parsing has started. This is (currently) only raised by ‘UseForeignDTD()’. -- Data: xml.parsers.expat.errors.XML_ERROR_UNBOUND_PREFIX An undeclared prefix was found when namespace processing was enabled. -- Data: xml.parsers.expat.errors.XML_ERROR_UNDECLARING_PREFIX The document attempted to remove the namespace declaration associated with a prefix. -- Data: xml.parsers.expat.errors.XML_ERROR_INCOMPLETE_PE A parameter entity contained incomplete markup. -- Data: xml.parsers.expat.errors.XML_ERROR_XML_DECL The document contained no document element at all. -- Data: xml.parsers.expat.errors.XML_ERROR_TEXT_DECL There was an error parsing a text declaration in an external entity. -- Data: xml.parsers.expat.errors.XML_ERROR_PUBLICID Characters were found in the public id that are not allowed. -- Data: xml.parsers.expat.errors.XML_ERROR_SUSPENDED The requested operation was made on a suspended parser, but isn’t allowed. This includes attempts to provide additional input or to stop the parser. -- Data: xml.parsers.expat.errors.XML_ERROR_NOT_SUSPENDED An attempt to resume the parser was made when the parser had not been suspended. -- Data: xml.parsers.expat.errors.XML_ERROR_ABORTED This should not be reported to Python applications. -- Data: xml.parsers.expat.errors.XML_ERROR_FINISHED The requested operation was made on a parser which was finished parsing input, but isn’t allowed. This includes attempts to provide additional input or to stop the parser. -- Data: xml.parsers.expat.errors.XML_ERROR_SUSPEND_PE  File: python.info, Node: Internet Protocols and Support, Next: Multimedia Services, Prev: Structured Markup Processing Tools, Up: The Python Standard Library 5.21 Internet Protocols and Support =================================== The modules described in this chapter implement Internet protocols and support for related technology. They are all implemented in Python. Most of these modules require the presence of the system-dependent module *note socket: ef, which is currently supported on most popular platforms. Here is an overview: * Menu: * webbrowser — Convenient Web-browser controller:: * cgi — Common Gateway Interface support:: * cgitb — Traceback manager for CGI scripts:: * wsgiref — WSGI Utilities and Reference Implementation:: * urllib — URL handling modules:: * urllib.request — Extensible library for opening URLs: urllib request — Extensible library for opening URLs. * urllib.response — Response classes used by urllib: urllib response — Response classes used by urllib. * urllib.parse — Parse URLs into components: urllib parse — Parse URLs into components. * urllib.error — Exception classes raised by urllib.request: urllib error — Exception classes raised by urllib request. * urllib.robotparser — Parser for robots.txt: urllib robotparser — Parser for robots txt. * http — HTTP modules:: * http.client — HTTP protocol client: http client — HTTP protocol client. * ftplib — FTP protocol client:: * poplib — POP3 protocol client:: * imaplib — IMAP4 protocol client:: * nntplib — NNTP protocol client:: * smtplib — SMTP protocol client:: * smtpd — SMTP Server:: * telnetlib — Telnet client:: * uuid — UUID objects according to RFC 4122:: * socketserver — A framework for network servers:: * http.server — HTTP servers: http server — HTTP servers. * http.cookies — HTTP state management: http cookies — HTTP state management. * http.cookiejar — Cookie handling for HTTP clients: http cookiejar — Cookie handling for HTTP clients. * xmlrpc — XMLRPC server and client modules:: * xmlrpc.client — XML-RPC client access: xmlrpc client — XML-RPC client access. * xmlrpc.server — Basic XML-RPC servers: xmlrpc server — Basic XML-RPC servers. * ipaddress — IPv4/IPv6 manipulation library::  File: python.info, Node: webbrowser — Convenient Web-browser controller, Next: cgi — Common Gateway Interface support, Up: Internet Protocols and Support 5.21.1 ‘webbrowser’ — Convenient Web-browser controller ------------------------------------------------------- `Source code:' Lib/webbrowser.py(1) __________________________________________________________________ The *note webbrowser: 129. module provides a high-level interface to allow displaying Web-based documents to users. Under most circumstances, simply calling the *note open(): 28d1. function from this module will do the right thing. Under Unix, graphical browsers are preferred under X11, but text-mode browsers will be used if graphical browsers are not available or an X11 display isn’t available. If text-mode browsers are used, the calling process will block until the user exits the browser. If the environment variable ‘BROWSER’ exists, it is interpreted as the *note os.pathsep: ff0.-separated list of browsers to try ahead of the platform defaults. When the value of a list part contains the string ‘%s’, then it is interpreted as a literal browser command line to be used with the argument URL substituted for ‘%s’; if the part does not contain ‘%s’, it is simply interpreted as the name of the browser to launch. (2) For non-Unix platforms, or when a remote browser is available on Unix, the controlling process will not wait for the user to finish with the browser, but allow the remote browser to maintain its own windows on the display. If remote browsers are not available on Unix, the controlling process will launch a new browser and wait. The script ‘webbrowser’ can be used as a command-line interface for the module. It accepts a URL as the argument. It accepts the following optional parameters: ‘-n’ opens the URL in a new browser window, if possible; ‘-t’ opens the URL in a new browser page (“tab”). The options are, naturally, mutually exclusive. Usage example: python -m webbrowser -t "http://www.python.org" The following exception is defined: -- Exception: webbrowser.Error Exception raised when a browser control error occurs. The following functions are defined: -- Function: webbrowser.open (url, new=0, autoraise=True) Display `url' using the default browser. If `new' is 0, the `url' is opened in the same browser window if possible. If `new' is 1, a new browser window is opened if possible. If `new' is 2, a new browser page (“tab”) is opened if possible. If `autoraise' is ‘True’, the window is raised if possible (note that under many window managers this will occur regardless of the setting of this variable). Note that on some platforms, trying to open a filename using this function, may work and start the operating system’s associated program. However, this is neither supported nor portable. Raises an *note auditing event: fd1. ‘webbrowser.open’ with argument ‘url’. -- Function: webbrowser.open_new (url) Open `url' in a new window of the default browser, if possible, otherwise, open `url' in the only browser window. -- Function: webbrowser.open_new_tab (url) Open `url' in a new page (“tab”) of the default browser, if possible, otherwise equivalent to *note open_new(): 28d3. -- Function: webbrowser.get (using=None) Return a controller object for the browser type `using'. If `using' is ‘None’, return a controller for a default browser appropriate to the caller’s environment. -- Function: webbrowser.register (name, constructor, instance=None, *, preferred=False) Register the browser type `name'. Once a browser type is registered, the *note get(): 28d5. function can return a controller for that browser type. If `instance' is not provided, or is ‘None’, `constructor' will be called without parameters to create an instance when needed. If `instance' is provided, `constructor' will never be called, and may be ‘None’. Setting `preferred' to ‘True’ makes this browser a preferred result for a *note get(): 28d5. call with no argument. Otherwise, this entry point is only useful if you plan to either set the ‘BROWSER’ variable or call *note get(): 28d5. with a nonempty argument matching the name of a handler you declare. Changed in version 3.7: `preferred' keyword-only parameter was added. A number of browser types are predefined. This table gives the type names that may be passed to the *note get(): 28d5. function and the corresponding instantiations for the controller classes, all defined in this module. Type Name Class Name Notes --------------------------------------------------------------------------------------- ‘'mozilla'’ ‘Mozilla('mozilla')’ ‘'firefox'’ ‘Mozilla('mozilla')’ ‘'netscape'’ ‘Mozilla('netscape')’ ‘'galeon'’ ‘Galeon('galeon')’ ‘'epiphany'’ ‘Galeon('epiphany')’ ‘'skipstone'’ ‘BackgroundBrowser('skipstone')’ ‘'kfmclient'’ ‘Konqueror()’ (1) ‘'konqueror'’ ‘Konqueror()’ (1) ‘'kfm'’ ‘Konqueror()’ (1) ‘'mosaic'’ ‘BackgroundBrowser('mosaic')’ ‘'opera'’ ‘Opera()’ ‘'grail'’ ‘Grail()’ ‘'links'’ ‘GenericBrowser('links')’ ‘'elinks'’ ‘Elinks('elinks')’ ‘'lynx'’ ‘GenericBrowser('lynx')’ ‘'w3m'’ ‘GenericBrowser('w3m')’ ‘'windows-default'’ ‘WindowsDefault’ (2) ‘'macosx'’ ‘MacOSX('default')’ (3) ‘'safari'’ ‘MacOSX('safari')’ (3) ‘'google-chrome'’ ‘Chrome('google-chrome')’ ‘'chrome'’ ‘Chrome('chrome')’ ‘'chromium'’ ‘Chromium('chromium')’ ‘'chromium-browser'’ ‘Chromium('chromium-browser')’ Notes: 1. “Konqueror” is the file manager for the KDE desktop environment for Unix, and only makes sense to use if KDE is running. Some way of reliably detecting KDE would be nice; the ‘KDEDIR’ variable is not sufficient. Note also that the name “kfm” is used even when using the ‘konqueror’ command with KDE 2 — the implementation selects the best strategy for running Konqueror. 2. Only on Windows platforms. 3. Only on Mac OS X platform. New in version 3.3: Support for Chrome/Chromium has been added. Here are some simple examples: url = 'http://docs.python.org/' # Open URL in a new tab, if a browser window is already open. webbrowser.open_new_tab(url) # Open URL in new window, raising the window if possible. webbrowser.open_new(url) * Menu: * Browser Controller Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/webbrowser.py (2) (1) Executables named here without a full path will be searched in the directories given in the ‘PATH’ environment variable.  File: python.info, Node: Browser Controller Objects, Up: webbrowser — Convenient Web-browser controller 5.21.1.1 Browser Controller Objects ................................... Browser controllers provide these methods which parallel three of the module-level convenience functions: -- Method: controller.open (url, new=0, autoraise=True) Display `url' using the browser handled by this controller. If `new' is 1, a new browser window is opened if possible. If `new' is 2, a new browser page (“tab”) is opened if possible. -- Method: controller.open_new (url) Open `url' in a new window of the browser handled by this controller, if possible, otherwise, open `url' in the only browser window. Alias *note open_new(): 28d3. -- Method: controller.open_new_tab (url) Open `url' in a new page (“tab”) of the browser handled by this controller, if possible, otherwise equivalent to *note open_new(): 28d3.  File: python.info, Node: cgi — Common Gateway Interface support, Next: cgitb — Traceback manager for CGI scripts, Prev: webbrowser — Convenient Web-browser controller, Up: Internet Protocols and Support 5.21.2 ‘cgi’ — Common Gateway Interface support ----------------------------------------------- `Source code:' Lib/cgi.py(1) __________________________________________________________________ Support module for Common Gateway Interface (CGI) scripts. This module defines a number of utilities for use by CGI scripts written in Python. * Menu: * Introduction: Introduction<10>. * Using the cgi module:: * Higher Level Interface:: * Functions: Functions<8>. * Caring about security:: * Installing your CGI script on a Unix system:: * Testing your CGI script:: * Debugging CGI scripts:: * Common problems and solutions:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/cgi.py  File: python.info, Node: Introduction<10>, Next: Using the cgi module, Up: cgi — Common Gateway Interface support 5.21.2.1 Introduction ..................... A CGI script is invoked by an HTTP server, usually to process user input submitted through an HTML ‘
    ’ or ‘’ element. Most often, CGI scripts live in the server’s special ‘cgi-bin’ directory. The HTTP server places all sorts of information about the request (such as the client’s hostname, the requested URL, the query string, and lots of other goodies) in the script’s shell environment, executes the script, and sends the script’s output back to the client. The script’s input is connected to the client too, and sometimes the form data is read this way; at other times the form data is passed via the “query string” part of the URL. This module is intended to take care of the different cases and provide a simpler interface to the Python script. It also provides a number of utilities that help in debugging scripts, and the latest addition is support for file uploads from a form (if your browser supports it). The output of a CGI script should consist of two sections, separated by a blank line. The first section contains a number of headers, telling the client what kind of data is following. Python code to generate a minimal header section looks like this: print("Content-Type: text/html") # HTML is following print() # blank line, end of headers The second section is usually HTML, which allows the client software to display nicely formatted text with header, in-line images, etc. Here’s Python code that prints a simple piece of HTML: print("CGI script output") print("

    This is my first CGI script

    ") print("Hello, world!")  File: python.info, Node: Using the cgi module, Next: Higher Level Interface, Prev: Introduction<10>, Up: cgi — Common Gateway Interface support 5.21.2.2 Using the cgi module ............................. Begin by writing ‘import cgi’. When you write a new script, consider adding these lines: import cgitb cgitb.enable() This activates a special exception handler that will display detailed reports in the Web browser if any errors occur. If you’d rather not show the guts of your program to users of your script, you can have the reports saved to files instead, with code like this: import cgitb cgitb.enable(display=0, logdir="/path/to/logdir") It’s very helpful to use this feature during script development. The reports produced by *note cgitb: 17. provide information that can save you a lot of time in tracking down bugs. You can always remove the ‘cgitb’ line later when you have tested your script and are confident that it works correctly. To get at submitted form data, use the ‘FieldStorage’ class. If the form contains non-ASCII characters, use the `encoding' keyword parameter set to the value of the encoding defined for the document. It is usually contained in the META tag in the HEAD section of the HTML document or by the ‘Content-Type’ header). This reads the form contents from the standard input or the environment (depending on the value of various environment variables set according to the CGI standard). Since it may consume standard input, it should be instantiated only once. The ‘FieldStorage’ instance can be indexed like a Python dictionary. It allows membership testing with the *note in: 7a3. operator, and also supports the standard dictionary method *note keys(): c2a. and the built-in function *note len(): 150. Form fields containing empty strings are ignored and do not appear in the dictionary; to keep such values, provide a true value for the optional `keep_blank_values' keyword parameter when creating the ‘FieldStorage’ instance. For instance, the following code (which assumes that the ‘Content-Type’ header and blank line have already been printed) checks that the fields ‘name’ and ‘addr’ are both set to a non-empty string: form = cgi.FieldStorage() if "name" not in form or "addr" not in form: print("

    Error

    ") print("Please fill in the name and addr fields.") return print("

    name:", form["name"].value) print("

    addr:", form["addr"].value) ...further form processing here... Here the fields, accessed through ‘form[key]’, are themselves instances of ‘FieldStorage’ (or ‘MiniFieldStorage’, depending on the form encoding). The ‘value’ attribute of the instance yields the string value of the field. The ‘getvalue()’ method returns this string value directly; it also accepts an optional second argument as a default to return if the requested key is not present. If the submitted form data contains more than one field with the same name, the object retrieved by ‘form[key]’ is not a ‘FieldStorage’ or ‘MiniFieldStorage’ instance but a list of such instances. Similarly, in this situation, ‘form.getvalue(key)’ would return a list of strings. If you expect this possibility (when your HTML form contains multiple fields with the same name), use the *note getlist(): 28e2. method, which always returns a list of values (so that you do not need to special-case the single item case). For example, this code concatenates any number of username fields, separated by commas: value = form.getlist("username") usernames = ",".join(value) If a field represents an uploaded file, accessing the value via the ‘value’ attribute or the ‘getvalue()’ method reads the entire file in memory as bytes. This may not be what you want. You can test for an uploaded file by testing either the ‘filename’ attribute or the ‘file’ attribute. You can then read the data from the ‘file’ attribute before it is automatically closed as part of the garbage collection of the ‘FieldStorage’ instance (the *note read(): 702. and *note readline(): 13ae. methods will return bytes): fileitem = form["userfile"] if fileitem.file: # It's an uploaded file; count lines linecount = 0 while True: line = fileitem.file.readline() if not line: break linecount = linecount + 1 ‘FieldStorage’ objects also support being used in a *note with: 6e9. statement, which will automatically close them when done. If an error is encountered when obtaining the contents of an uploaded file (for example, when the user interrupts the form submission by clicking on a Back or Cancel button) the ‘done’ attribute of the object for the field will be set to the value -1. The file upload draft standard entertains the possibility of uploading multiple files from one field (using a recursive ‘multipart/*’ encoding). When this occurs, the item will be a dictionary-like ‘FieldStorage’ item. This can be determined by testing its ‘type’ attribute, which should be ‘multipart/form-data’ (or perhaps another MIME type matching ‘multipart/*’). In this case, it can be iterated over recursively just like the top-level form object. When a form is submitted in the “old” format (as the query string or as a single data part of type ‘application/x-www-form-urlencoded’), the items will actually be instances of the class ‘MiniFieldStorage’. In this case, the ‘list’, ‘file’, and ‘filename’ attributes are always ‘None’. A form submitted via POST that also has a query string will contain both ‘FieldStorage’ and ‘MiniFieldStorage’ items. Changed in version 3.4: The ‘file’ attribute is automatically closed upon the garbage collection of the creating ‘FieldStorage’ instance. Changed in version 3.5: Added support for the context management protocol to the ‘FieldStorage’ class.  File: python.info, Node: Higher Level Interface, Next: Functions<8>, Prev: Using the cgi module, Up: cgi — Common Gateway Interface support 5.21.2.3 Higher Level Interface ............................... The previous section explains how to read CGI form data using the ‘FieldStorage’ class. This section describes a higher level interface which was added to this class to allow one to do it in a more readable and intuitive way. The interface doesn’t make the techniques described in previous sections obsolete — they are still useful to process file uploads efficiently, for example. The interface consists of two simple methods. Using the methods you can process form data in a generic way, without the need to worry whether only one or more values were posted under one name. In the previous section, you learned to write following code anytime you expected a user to post more than one value under one name: item = form.getvalue("item") if isinstance(item, list): # The user is requesting more than one item. else: # The user is requesting only one item. This situation is common for example when a form contains a group of multiple checkboxes with the same name: In most situations, however, there’s only one form control with a particular name in a form and then you expect and need only one value associated with this name. So you write a script containing for example this code: user = form.getvalue("user").upper() The problem with the code is that you should never expect that a client will provide valid input to your scripts. For example, if a curious user appends another ‘user=foo’ pair to the query string, then the script would crash, because in this situation the ‘getvalue("user")’ method call returns a list instead of a string. Calling the *note upper(): 1309. method on a list is not valid (since lists do not have a method of this name) and results in an *note AttributeError: 39b. exception. Therefore, the appropriate way to read form data values was to always use the code which checks whether the obtained value is a single value or a list of values. That’s annoying and leads to less readable scripts. A more convenient approach is to use the methods *note getfirst(): 28e4. and *note getlist(): 28e2. provided by this higher level interface. -- Method: FieldStorage.getfirst (name, default=None) This method always returns only one value associated with form field `name'. The method returns only the first value in case that more values were posted under such name. Please note that the order in which the values are received may vary from browser to browser and should not be counted on. (1) If no such form field or value exists then the method returns the value specified by the optional parameter `default'. This parameter defaults to ‘None’ if not specified. -- Method: FieldStorage.getlist (name) This method always returns a list of values associated with form field `name'. The method returns an empty list if no such form field or value exists for `name'. It returns a list consisting of one item if only one such value exists. Using these methods you can write nice compact code: import cgi form = cgi.FieldStorage() user = form.getfirst("user", "").upper() # This way it's safe. for item in form.getlist("item"): do_something(item) ---------- Footnotes ---------- (1) (1) Note that some recent versions of the HTML specification do state what order the field values should be supplied in, but knowing whether a request was received from a conforming browser, or even from a browser at all, is tedious and error-prone.  File: python.info, Node: Functions<8>, Next: Caring about security, Prev: Higher Level Interface, Up: cgi — Common Gateway Interface support 5.21.2.4 Functions .................. These are useful if you want more control, or if you want to employ some of the algorithms implemented in this module in other circumstances. -- Function: cgi.parse (fp=None, environ=os.environ, keep_blank_values=False, strict_parsing=False, separator="&") Parse a query in the environment or from a file (the file defaults to ‘sys.stdin’). The `keep_blank_values', `strict_parsing' and `separator' parameters are passed to *note urllib.parse.parse_qs(): 2eb. unchanged. Changed in version 3.8.8: Added the `separator' parameter. -- Function: cgi.parse_multipart (fp, pdict, encoding="utf-8", errors="replace", separator="&") Parse input of type ‘multipart/form-data’ (for file uploads). Arguments are `fp' for the input file, `pdict' for a dictionary containing other parameters in the ‘Content-Type’ header, and `encoding', the request encoding. Returns a dictionary just like *note urllib.parse.parse_qs(): 2eb.: keys are the field names, each value is a list of values for that field. For non-file fields, the value is a list of strings. This is easy to use but not much good if you are expecting megabytes to be uploaded — in that case, use the ‘FieldStorage’ class instead which is much more flexible. Changed in version 3.7: Added the `encoding' and `errors' parameters. For non-file fields, the value is now a list of strings, not bytes. Changed in version 3.8.8: Added the `separator' parameter. -- Function: cgi.parse_header (string) Parse a MIME header (such as ‘Content-Type’) into a main value and a dictionary of parameters. -- Function: cgi.test () Robust test CGI script, usable as main program. Writes minimal HTTP headers and formats all information provided to the script in HTML form. -- Function: cgi.print_environ () Format the shell environment in HTML. -- Function: cgi.print_form (form) Format a form in HTML. -- Function: cgi.print_directory () Format the current directory in HTML. -- Function: cgi.print_environ_usage () Print a list of useful (used by CGI) environment variables in HTML.  File: python.info, Node: Caring about security, Next: Installing your CGI script on a Unix system, Prev: Functions<8>, Up: cgi — Common Gateway Interface support 5.21.2.5 Caring about security .............................. There’s one important rule: if you invoke an external program (via the *note os.system(): dc1. or *note os.popen(): 2a9. functions. or others with similar functionality), make very sure you don’t pass arbitrary strings received from the client to the shell. This is a well-known security hole whereby clever hackers anywhere on the Web can exploit a gullible CGI script to invoke arbitrary shell commands. Even parts of the URL or field names cannot be trusted, since the request doesn’t have to come from your form! To be on the safe side, if you must pass a string gotten from a form to a shell command, you should make sure the string contains only alphanumeric characters, dashes, underscores, and periods.  File: python.info, Node: Installing your CGI script on a Unix system, Next: Testing your CGI script, Prev: Caring about security, Up: cgi — Common Gateway Interface support 5.21.2.6 Installing your CGI script on a Unix system .................................................... Read the documentation for your HTTP server and check with your local system administrator to find the directory where CGI scripts should be installed; usually this is in a directory ‘cgi-bin’ in the server tree. Make sure that your script is readable and executable by “others”; the Unix file mode should be ‘0o755’ octal (use ‘chmod 0755 filename’). Make sure that the first line of the script contains ‘#!’ starting in column 1 followed by the pathname of the Python interpreter, for instance: #!/usr/local/bin/python Make sure the Python interpreter exists and is executable by “others”. Make sure that any files your script needs to read or write are readable or writable, respectively, by “others” — their mode should be ‘0o644’ for readable and ‘0o666’ for writable. This is because, for security reasons, the HTTP server executes your script as user “nobody”, without any special privileges. It can only read (write, execute) files that everybody can read (write, execute). The current directory at execution time is also different (it is usually the server’s cgi-bin directory) and the set of environment variables is also different from what you get when you log in. In particular, don’t count on the shell’s search path for executables ( ‘PATH’) or the Python module search path ( *note PYTHONPATH: 953.) to be set to anything interesting. If you need to load modules from a directory which is not on Python’s default module search path, you can change the path in your script, before importing other modules. For example: import sys sys.path.insert(0, "/usr/home/joe/lib/python") sys.path.insert(0, "/usr/local/lib/python") (This way, the directory inserted last will be searched first!) Instructions for non-Unix systems will vary; check your HTTP server’s documentation (it will usually have a section on CGI scripts).  File: python.info, Node: Testing your CGI script, Next: Debugging CGI scripts, Prev: Installing your CGI script on a Unix system, Up: cgi — Common Gateway Interface support 5.21.2.7 Testing your CGI script ................................ Unfortunately, a CGI script will generally not run when you try it from the command line, and a script that works perfectly from the command line may fail mysteriously when run from the server. There’s one reason why you should still test your script from the command line: if it contains a syntax error, the Python interpreter won’t execute it at all, and the HTTP server will most likely send a cryptic error to the client. Assuming your script has no syntax errors, yet it does not work, you have no choice but to read the next section.  File: python.info, Node: Debugging CGI scripts, Next: Common problems and solutions, Prev: Testing your CGI script, Up: cgi — Common Gateway Interface support 5.21.2.8 Debugging CGI scripts .............................. First of all, check for trivial installation errors — reading the section above on installing your CGI script carefully can save you a lot of time. If you wonder whether you have understood the installation procedure correctly, try installing a copy of this module file (‘cgi.py’) as a CGI script. When invoked as a script, the file will dump its environment and the contents of the form in HTML form. Give it the right mode etc, and send it a request. If it’s installed in the standard ‘cgi-bin’ directory, it should be possible to send it a request by entering a URL into your browser of the form: http://yourhostname/cgi-bin/cgi.py?name=Joe+Blow&addr=At+Home If this gives an error of type 404, the server cannot find the script – perhaps you need to install it in a different directory. If it gives another error, there’s an installation problem that you should fix before trying to go any further. If you get a nicely formatted listing of the environment and form content (in this example, the fields should be listed as “addr” with value “At Home” and “name” with value “Joe Blow”), the ‘cgi.py’ script has been installed correctly. If you follow the same procedure for your own script, you should now be able to debug it. The next step could be to call the *note cgi: 16. module’s *note test(): 105. function from your script: replace its main code with the single statement cgi.test() This should produce the same results as those gotten from installing the ‘cgi.py’ file itself. When an ordinary Python script raises an unhandled exception (for whatever reason: of a typo in a module name, a file that can’t be opened, etc.), the Python interpreter prints a nice traceback and exits. While the Python interpreter will still do this when your CGI script raises an exception, most likely the traceback will end up in one of the HTTP server’s log files, or be discarded altogether. Fortunately, once you have managed to get your script to execute `some' code, you can easily send tracebacks to the Web browser using the *note cgitb: 17. module. If you haven’t done so already, just add the lines: import cgitb cgitb.enable() to the top of your script. Then try running it again; when a problem occurs, you should see a detailed report that will likely make apparent the cause of the crash. If you suspect that there may be a problem in importing the *note cgitb: 17. module, you can use an even more robust approach (which only uses built-in modules): import sys sys.stderr = sys.stdout print("Content-Type: text/plain") print() ...your code here... This relies on the Python interpreter to print the traceback. The content type of the output is set to plain text, which disables all HTML processing. If your script works, the raw HTML will be displayed by your client. If it raises an exception, most likely after the first two lines have been printed, a traceback will be displayed. Because no HTML interpretation is going on, the traceback will be readable.  File: python.info, Node: Common problems and solutions, Prev: Debugging CGI scripts, Up: cgi — Common Gateway Interface support 5.21.2.9 Common problems and solutions ...................................... * Most HTTP servers buffer the output from CGI scripts until the script is completed. This means that it is not possible to display a progress report on the client’s display while the script is running. * Check the installation instructions above. * Check the HTTP server’s log files. (‘tail -f logfile’ in a separate window may be useful!) * Always check a script for syntax errors first, by doing something like ‘python script.py’. * If your script does not have any syntax errors, try adding ‘import cgitb; cgitb.enable()’ to the top of the script. * When invoking external programs, make sure they can be found. Usually, this means using absolute path names — ‘PATH’ is usually not set to a very useful value in a CGI script. * When reading or writing external files, make sure they can be read or written by the userid under which your CGI script will be running: this is typically the userid under which the web server is running, or some explicitly specified userid for a web server’s ‘suexec’ feature. * Don’t try to give a CGI script a set-uid mode. This doesn’t work on most systems, and is a security liability as well.  File: python.info, Node: cgitb — Traceback manager for CGI scripts, Next: wsgiref — WSGI Utilities and Reference Implementation, Prev: cgi — Common Gateway Interface support, Up: Internet Protocols and Support 5.21.3 ‘cgitb’ — Traceback manager for CGI scripts -------------------------------------------------- `Source code:' Lib/cgitb.py(1) __________________________________________________________________ The *note cgitb: 17. module provides a special exception handler for Python scripts. (Its name is a bit misleading. It was originally designed to display extensive traceback information in HTML for CGI scripts. It was later generalized to also display this information in plain text.) After this module is activated, if an uncaught exception occurs, a detailed, formatted report will be displayed. The report includes a traceback showing excerpts of the source code for each level, as well as the values of the arguments and local variables to currently running functions, to help you debug the problem. Optionally, you can save this information to a file instead of sending it to the browser. To enable this feature, simply add this to the top of your CGI script: import cgitb cgitb.enable() The options to the *note enable(): 28f5. function control whether the report is displayed in the browser and whether the report is logged to a file for later analysis. -- Function: cgitb.enable (display=1, logdir=None, context=5, format="html") This function causes the *note cgitb: 17. module to take over the interpreter’s default handling for exceptions by setting the value of *note sys.excepthook: e63. The optional argument `display' defaults to ‘1’ and can be set to ‘0’ to suppress sending the traceback to the browser. If the argument `logdir' is present, the traceback reports are written to files. The value of `logdir' should be a directory where these files will be placed. The optional argument `context' is the number of lines of context to display around the current line of source code in the traceback; this defaults to ‘5’. If the optional argument `format' is ‘"html"’, the output is formatted as HTML. Any other value forces plain text output. The default value is ‘"html"’. -- Function: cgitb.text (info, context=5) This function handles the exception described by `info' (a 3-tuple containing the result of *note sys.exc_info(): c5f.), formatting its traceback as text and returning the result as a string. The optional argument `context' is the number of lines of context to display around the current line of source code in the traceback; this defaults to ‘5’. -- Function: cgitb.html (info, context=5) This function handles the exception described by `info' (a 3-tuple containing the result of *note sys.exc_info(): c5f.), formatting its traceback as HTML and returning the result as a string. The optional argument `context' is the number of lines of context to display around the current line of source code in the traceback; this defaults to ‘5’. -- Function: cgitb.handler (info=None) This function handles an exception using the default settings (that is, show a report in the browser, but don’t log to a file). This can be used when you’ve caught an exception and want to report it using *note cgitb: 17. The optional `info' argument should be a 3-tuple containing an exception type, exception value, and traceback object, exactly like the tuple returned by *note sys.exc_info(): c5f. If the `info' argument is not supplied, the current exception is obtained from *note sys.exc_info(): c5f. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/cgitb.py  File: python.info, Node: wsgiref — WSGI Utilities and Reference Implementation, Next: urllib — URL handling modules, Prev: cgitb — Traceback manager for CGI scripts, Up: Internet Protocols and Support 5.21.4 ‘wsgiref’ — WSGI Utilities and Reference Implementation -------------------------------------------------------------- __________________________________________________________________ The Web Server Gateway Interface (WSGI) is a standard interface between web server software and web applications written in Python. Having a standard interface makes it easy to use an application that supports WSGI with a number of different web servers. Only authors of web servers and programming frameworks need to know every detail and corner case of the WSGI design. You don’t need to understand every detail of WSGI just to install a WSGI application or to write a web application using an existing framework. *note wsgiref: 12c. is a reference implementation of the WSGI specification that can be used to add WSGI support to a web server or framework. It provides utilities for manipulating WSGI environment variables and response headers, base classes for implementing WSGI servers, a demo HTTP server that serves WSGI applications, and a validation tool that checks WSGI servers and applications for conformance to the WSGI specification ( PEP 3333(1)). See wsgi.readthedocs.io(2) for more information about WSGI, and links to tutorials and other resources. * Menu: * wsgiref.util – WSGI environment utilities: wsgiref util – WSGI environment utilities. * wsgiref.headers – WSGI response header tools: wsgiref headers – WSGI response header tools. * wsgiref.simple_server – a simple WSGI HTTP server: wsgiref simple_server – a simple WSGI HTTP server. * wsgiref.validate — WSGI conformance checker: wsgiref validate — WSGI conformance checker. * wsgiref.handlers – server/gateway base classes: wsgiref handlers – server/gateway base classes. * Examples: Examples<20>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333 (2) https://wsgi.readthedocs.io/  File: python.info, Node: wsgiref util – WSGI environment utilities, Next: wsgiref headers – WSGI response header tools, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.1 ‘wsgiref.util’ – WSGI environment utilities .................................................... This module provides a variety of utility functions for working with WSGI environments. A WSGI environment is a dictionary containing HTTP request variables as described in PEP 3333(1). All of the functions taking an `environ' parameter expect a WSGI-compliant dictionary to be supplied; please see PEP 3333(2) for a detailed specification. -- Function: wsgiref.util.guess_scheme (environ) Return a guess for whether ‘wsgi.url_scheme’ should be “http” or “https”, by checking for a ‘HTTPS’ environment variable in the `environ' dictionary. The return value is a string. This function is useful when creating a gateway that wraps CGI or a CGI-like protocol such as FastCGI. Typically, servers providing such protocols will include a ‘HTTPS’ variable with a value of “1”, “yes”, or “on” when a request is received via SSL. So, this function returns “https” if such a value is found, and “http” otherwise. -- Function: wsgiref.util.request_uri (environ, include_query=True) Return the full request URI, optionally including the query string, using the algorithm found in the “URL Reconstruction” section of PEP 3333(3). If `include_query' is false, the query string is not included in the resulting URI. -- Function: wsgiref.util.application_uri (environ) Similar to *note request_uri(): 28fd, except that the ‘PATH_INFO’ and ‘QUERY_STRING’ variables are ignored. The result is the base URI of the application object addressed by the request. -- Function: wsgiref.util.shift_path_info (environ) Shift a single name from ‘PATH_INFO’ to ‘SCRIPT_NAME’ and return the name. The `environ' dictionary is `modified' in-place; use a copy if you need to keep the original ‘PATH_INFO’ or ‘SCRIPT_NAME’ intact. If there are no remaining path segments in ‘PATH_INFO’, ‘None’ is returned. Typically, this routine is used to process each portion of a request URI path, for example to treat the path as a series of dictionary keys. This routine modifies the passed-in environment to make it suitable for invoking another WSGI application that is located at the target URI. For example, if there is a WSGI application at ‘/foo’, and the request URI path is ‘/foo/bar/baz’, and the WSGI application at ‘/foo’ calls *note shift_path_info(): 28ff, it will receive the string “bar”, and the environment will be updated to be suitable for passing to a WSGI application at ‘/foo/bar’. That is, ‘SCRIPT_NAME’ will change from ‘/foo’ to ‘/foo/bar’, and ‘PATH_INFO’ will change from ‘/bar/baz’ to ‘/baz’. When ‘PATH_INFO’ is just a “/”, this routine returns an empty string and appends a trailing slash to ‘SCRIPT_NAME’, even though empty path segments are normally ignored, and ‘SCRIPT_NAME’ doesn’t normally end in a slash. This is intentional behavior, to ensure that an application can tell the difference between URIs ending in ‘/x’ from ones ending in ‘/x/’ when using this routine to do object traversal. -- Function: wsgiref.util.setup_testing_defaults (environ) Update `environ' with trivial defaults for testing purposes. This routine adds various parameters required for WSGI, including ‘HTTP_HOST’, ‘SERVER_NAME’, ‘SERVER_PORT’, ‘REQUEST_METHOD’, ‘SCRIPT_NAME’, ‘PATH_INFO’, and all of the PEP 3333(4)-defined ‘wsgi.*’ variables. It only supplies default values, and does not replace any existing settings for these variables. This routine is intended to make it easier for unit tests of WSGI servers and applications to set up dummy environments. It should NOT be used by actual WSGI servers or applications, since the data is fake! Example usage: from wsgiref.util import setup_testing_defaults from wsgiref.simple_server import make_server # A relatively simple WSGI application. It's going to print out the # environment dictionary after being updated by setup_testing_defaults def simple_app(environ, start_response): setup_testing_defaults(environ) status = '200 OK' headers = [('Content-type', 'text/plain; charset=utf-8')] start_response(status, headers) ret = [("%s: %s\n" % (key, value)).encode("utf-8") for key, value in environ.items()] return ret with make_server('', 8000, simple_app) as httpd: print("Serving on port 8000...") httpd.serve_forever() In addition to the environment functions above, the *note wsgiref.util: 130. module also provides these miscellaneous utilities: -- Function: wsgiref.util.is_hop_by_hop (header_name) Return ‘True’ if ‘header_name’ is an HTTP/1.1 “Hop-by-Hop” header, as defined by RFC 2616(5). -- Class: wsgiref.util.FileWrapper (filelike, blksize=8192) A wrapper to convert a file-like object to an *note iterator: 112e. The resulting objects support both *note __getitem__(): 27c. and *note __iter__(): 50f. iteration styles, for compatibility with Python 2.1 and Jython. As the object is iterated over, the optional `blksize' parameter will be repeatedly passed to the `filelike' object’s ‘read()’ method to obtain bytestrings to yield. When ‘read()’ returns an empty bytestring, iteration is ended and is not resumable. If `filelike' has a ‘close()’ method, the returned object will also have a ‘close()’ method, and it will invoke the `filelike' object’s ‘close()’ method when called. Example usage: from io import StringIO from wsgiref.util import FileWrapper # We're using a StringIO-buffer for as the file-like object filelike = StringIO("This is an example file-like object"*10) wrapper = FileWrapper(filelike, blksize=5) for chunk in wrapper: print(chunk) Deprecated since version 3.8: Support for *note sequence protocol: 27c. is deprecated. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333 (2) https://www.python.org/dev/peps/pep-3333 (3) https://www.python.org/dev/peps/pep-3333 (4) https://www.python.org/dev/peps/pep-3333 (5) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: wsgiref headers – WSGI response header tools, Next: wsgiref simple_server – a simple WSGI HTTP server, Prev: wsgiref util – WSGI environment utilities, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.2 ‘wsgiref.headers’ – WSGI response header tools ....................................................... This module provides a single class, *note Headers: 78f, for convenient manipulation of WSGI response headers using a mapping-like interface. -- Class: wsgiref.headers.Headers ([headers]) Create a mapping-like object wrapping `headers', which must be a list of header name/value tuples as described in PEP 3333(1). The default value of `headers' is an empty list. *note Headers: 78f. objects support typical mapping operations including *note __getitem__(): 27c, ‘get()’, *note __setitem__(): c62, ‘setdefault()’, *note __delitem__(): c63. and *note __contains__(): d28. For each of these methods, the key is the header name (treated case-insensitively), and the value is the first value associated with that header name. Setting a header deletes any existing values for that header, then adds a new value at the end of the wrapped header list. Headers’ existing order is generally maintained, with new headers added to the end of the wrapped list. Unlike a dictionary, *note Headers: 78f. objects do not raise an error when you try to get or delete a key that isn’t in the wrapped header list. Getting a nonexistent header just returns ‘None’, and deleting a nonexistent header does nothing. *note Headers: 78f. objects also support ‘keys()’, ‘values()’, and ‘items()’ methods. The lists returned by ‘keys()’ and ‘items()’ can include the same key more than once if there is a multi-valued header. The ‘len()’ of a *note Headers: 78f. object is the same as the length of its ‘items()’, which is the same as the length of the wrapped header list. In fact, the ‘items()’ method just returns a copy of the wrapped header list. Calling ‘bytes()’ on a *note Headers: 78f. object returns a formatted bytestring suitable for transmission as HTTP response headers. Each header is placed on a line with its value, separated by a colon and a space. Each line is terminated by a carriage return and line feed, and the bytestring is terminated with a blank line. In addition to their mapping interface and formatting features, *note Headers: 78f. objects also have the following methods for querying and adding multi-valued headers, and for adding headers with MIME parameters: -- Method: get_all (name) Return a list of all the values for the named header. The returned list will be sorted in the order they appeared in the original header list or were added to this instance, and may contain duplicates. Any fields deleted and re-inserted are always appended to the header list. If no fields exist with the given name, returns an empty list. -- Method: add_header (name, value, **_params) Add a (possibly multi-valued) header, with optional MIME parameters specified via keyword arguments. `name' is the header field to add. Keyword arguments can be used to set MIME parameters for the header field. Each parameter must be a string or ‘None’. Underscores in parameter names are converted to dashes, since dashes are illegal in Python identifiers, but many MIME parameter names include dashes. If the parameter value is a string, it is added to the header value parameters in the form ‘name="value"’. If it is ‘None’, only the parameter name is added. (This is used for MIME parameters without a value.) Example usage: h.add_header('content-disposition', 'attachment', filename='bud.gif') The above will add a header that looks like this: Content-Disposition: attachment; filename="bud.gif" Changed in version 3.5: `headers' parameter is optional. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333  File: python.info, Node: wsgiref simple_server – a simple WSGI HTTP server, Next: wsgiref validate — WSGI conformance checker, Prev: wsgiref headers – WSGI response header tools, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.3 ‘wsgiref.simple_server’ – a simple WSGI HTTP server ............................................................ This module implements a simple HTTP server (based on *note http.server: 97.) that serves WSGI applications. Each server instance serves a single WSGI application on a given host and port. If you want to serve multiple applications on a single host and port, you should create a WSGI application that parses ‘PATH_INFO’ to select which application to invoke for each request. (E.g., using the ‘shift_path_info()’ function from *note wsgiref.util: 130.) -- Function: wsgiref.simple_server.make_server (host, port, app, server_class=WSGIServer, handler_class=WSGIRequestHandler) Create a new WSGI server listening on `host' and `port', accepting connections for `app'. The return value is an instance of the supplied `server_class', and will process requests using the specified `handler_class'. `app' must be a WSGI application object, as defined by PEP 3333(1). Example usage: from wsgiref.simple_server import make_server, demo_app with make_server('', 8000, demo_app) as httpd: print("Serving HTTP on port 8000...") # Respond to requests until process is killed httpd.serve_forever() # Alternative: serve one request, then exit httpd.handle_request() -- Function: wsgiref.simple_server.demo_app (environ, start_response) This function is a small but complete WSGI application that returns a text page containing the message “Hello world!” and a list of the key/value pairs provided in the `environ' parameter. It’s useful for verifying that a WSGI server (such as *note wsgiref.simple_server: 12f.) is able to run a simple WSGI application correctly. -- Class: wsgiref.simple_server.WSGIServer (server_address, RequestHandlerClass) Create a *note WSGIServer: 2908. instance. `server_address' should be a ‘(host,port)’ tuple, and `RequestHandlerClass' should be the subclass of *note http.server.BaseHTTPRequestHandler: a0e. that will be used to process requests. You do not normally need to call this constructor, as the *note make_server(): 2906. function can handle all the details for you. *note WSGIServer: 2908. is a subclass of *note http.server.HTTPServer: 2909, so all of its methods (such as ‘serve_forever()’ and ‘handle_request()’) are available. *note WSGIServer: 2908. also provides these WSGI-specific methods: -- Method: set_app (application) Sets the callable `application' as the WSGI application that will receive requests. -- Method: get_app () Returns the currently-set application callable. Normally, however, you do not need to use these additional methods, as *note set_app(): 290a. is normally called by *note make_server(): 2906, and the *note get_app(): 290b. exists mainly for the benefit of request handler instances. -- Class: wsgiref.simple_server.WSGIRequestHandler (request, client_address, server) Create an HTTP handler for the given `request' (i.e. a socket), `client_address' (a ‘(host,port)’ tuple), and `server' (*note WSGIServer: 2908. instance). You do not need to create instances of this class directly; they are automatically created as needed by *note WSGIServer: 2908. objects. You can, however, subclass this class and supply it as a `handler_class' to the *note make_server(): 2906. function. Some possibly relevant methods for overriding in subclasses: -- Method: get_environ () Returns a dictionary containing the WSGI environment for a request. The default implementation copies the contents of the *note WSGIServer: 2908. object’s ‘base_environ’ dictionary attribute and then adds various headers derived from the HTTP request. Each call to this method should return a new dictionary containing all of the relevant CGI environment variables as specified in PEP 3333(2). -- Method: get_stderr () Return the object that should be used as the ‘wsgi.errors’ stream. The default implementation just returns ‘sys.stderr’. -- Method: handle () Process the HTTP request. The default implementation creates a handler instance using a *note wsgiref.handlers: 12d. class to implement the actual WSGI application interface. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333 (2) https://www.python.org/dev/peps/pep-3333  File: python.info, Node: wsgiref validate — WSGI conformance checker, Next: wsgiref handlers – server/gateway base classes, Prev: wsgiref simple_server – a simple WSGI HTTP server, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.4 ‘wsgiref.validate’ — WSGI conformance checker ...................................................... When creating new WSGI application objects, frameworks, servers, or middleware, it can be useful to validate the new code’s conformance using *note wsgiref.validate: 131. This module provides a function that creates WSGI application objects that validate communications between a WSGI server or gateway and a WSGI application object, to check both sides for protocol conformance. Note that this utility does not guarantee complete PEP 3333(1) compliance; an absence of errors from this module does not necessarily mean that errors do not exist. However, if this module does produce an error, then it is virtually certain that either the server or application is not 100% compliant. This module is based on the ‘paste.lint’ module from Ian Bicking’s “Python Paste” library. -- Function: wsgiref.validate.validator (application) Wrap `application' and return a new WSGI application object. The returned application will forward all requests to the original `application', and will check that both the `application' and the server invoking it are conforming to the WSGI specification and to RFC 2616(2). Any detected nonconformance results in an *note AssertionError: 1223. being raised; note, however, that how these errors are handled is server-dependent. For example, *note wsgiref.simple_server: 12f. and other servers based on *note wsgiref.handlers: 12d. (that don’t override the error handling methods to do something else) will simply output a message that an error has occurred, and dump the traceback to ‘sys.stderr’ or some other error stream. This wrapper may also generate output using the *note warnings: 126. module to indicate behaviors that are questionable but which may not actually be prohibited by PEP 3333(3). Unless they are suppressed using Python command-line options or the *note warnings: 126. API, any such warnings will be written to ‘sys.stderr’ (`not' ‘wsgi.errors’, unless they happen to be the same object). Example usage: from wsgiref.validate import validator from wsgiref.simple_server import make_server # Our callable object which is intentionally not compliant to the # standard, so the validator is going to break def simple_app(environ, start_response): status = '200 OK' # HTTP Status headers = [('Content-type', 'text/plain')] # HTTP Headers start_response(status, headers) # This is going to break because we need to return a list, and # the validator is going to inform us return b"Hello World" # This is the application wrapped in a validator validator_app = validator(simple_app) with make_server('', 8000, validator_app) as httpd: print("Listening on port 8000....") httpd.serve_forever() ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333 (2) https://tools.ietf.org/html/rfc2616.html (3) https://www.python.org/dev/peps/pep-3333  File: python.info, Node: wsgiref handlers – server/gateway base classes, Next: Examples<20>, Prev: wsgiref validate — WSGI conformance checker, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.5 ‘wsgiref.handlers’ – server/gateway base classes ......................................................... This module provides base handler classes for implementing WSGI servers and gateways. These base classes handle most of the work of communicating with a WSGI application, as long as they are given a CGI-like environment, along with input, output, and error streams. -- Class: wsgiref.handlers.CGIHandler CGI-based invocation via ‘sys.stdin’, ‘sys.stdout’, ‘sys.stderr’ and ‘os.environ’. This is useful when you have a WSGI application and want to run it as a CGI script. Simply invoke ‘CGIHandler().run(app)’, where ‘app’ is the WSGI application object you wish to invoke. This class is a subclass of *note BaseCGIHandler: 2914. that sets ‘wsgi.run_once’ to true, ‘wsgi.multithread’ to false, and ‘wsgi.multiprocess’ to true, and always uses *note sys: fd. and *note os: c4. to obtain the necessary CGI streams and environment. -- Class: wsgiref.handlers.IISCGIHandler A specialized alternative to *note CGIHandler: 2913, for use when deploying on Microsoft’s IIS web server, without having set the config allowPathInfo option (IIS>=7) or metabase allowPathInfoForScriptMappings (IIS<7). By default, IIS gives a ‘PATH_INFO’ that duplicates the ‘SCRIPT_NAME’ at the front, causing problems for WSGI applications that wish to implement routing. This handler strips any such duplicated path. IIS can be configured to pass the correct ‘PATH_INFO’, but this causes another bug where ‘PATH_TRANSLATED’ is wrong. Luckily this variable is rarely used and is not guaranteed by WSGI. On IIS<7, though, the setting can only be made on a vhost level, affecting all other script mappings, many of which break when exposed to the ‘PATH_TRANSLATED’ bug. For this reason IIS<7 is almost never deployed with the fix (Even IIS7 rarely uses it because there is still no UI for it.). There is no way for CGI code to tell whether the option was set, so a separate handler class is provided. It is used in the same way as *note CGIHandler: 2913, i.e., by calling ‘IISCGIHandler().run(app)’, where ‘app’ is the WSGI application object you wish to invoke. New in version 3.2. -- Class: wsgiref.handlers.BaseCGIHandler (stdin, stdout, stderr, environ, multithread=True, multiprocess=False) Similar to *note CGIHandler: 2913, but instead of using the *note sys: fd. and *note os: c4. modules, the CGI environment and I/O streams are specified explicitly. The `multithread' and `multiprocess' values are used to set the ‘wsgi.multithread’ and ‘wsgi.multiprocess’ flags for any applications run by the handler instance. This class is a subclass of *note SimpleHandler: 2916. intended for use with software other than HTTP “origin servers”. If you are writing a gateway protocol implementation (such as CGI, FastCGI, SCGI, etc.) that uses a ‘Status:’ header to send an HTTP status, you probably want to subclass this instead of *note SimpleHandler: 2916. -- Class: wsgiref.handlers.SimpleHandler (stdin, stdout, stderr, environ, multithread=True, multiprocess=False) Similar to *note BaseCGIHandler: 2914, but designed for use with HTTP origin servers. If you are writing an HTTP server implementation, you will probably want to subclass this instead of *note BaseCGIHandler: 2914. This class is a subclass of *note BaseHandler: 2917. It overrides the *note __init__(): d5e, ‘get_stdin()’, ‘get_stderr()’, ‘add_cgi_vars()’, ‘_write()’, and ‘_flush()’ methods to support explicitly setting the environment and streams via the constructor. The supplied environment and streams are stored in the ‘stdin’, ‘stdout’, ‘stderr’, and ‘environ’ attributes. The *note write(): 589. method of `stdout' should write each chunk in full, like *note io.BufferedIOBase: 588. -- Class: wsgiref.handlers.BaseHandler This is an abstract base class for running WSGI applications. Each instance will handle a single HTTP request, although in principle you could create a subclass that was reusable for multiple requests. *note BaseHandler: 2917. instances have only one method intended for external use: -- Method: run (app) Run the specified WSGI application, `app'. All of the other *note BaseHandler: 2917. methods are invoked by this method in the process of running the application, and thus exist primarily to allow customizing the process. The following methods MUST be overridden in a subclass: -- Method: _write (data) Buffer the bytes `data' for transmission to the client. It’s okay if this method actually transmits the data; *note BaseHandler: 2917. just separates write and flush operations for greater efficiency when the underlying system actually has such a distinction. -- Method: _flush () Force buffered data to be transmitted to the client. It’s okay if this method is a no-op (i.e., if *note _write(): 2919. actually sends the data). -- Method: get_stdin () Return an input stream object suitable for use as the ‘wsgi.input’ of the request currently being processed. -- Method: get_stderr () Return an output stream object suitable for use as the ‘wsgi.errors’ of the request currently being processed. -- Method: add_cgi_vars () Insert CGI variables for the current request into the ‘environ’ attribute. Here are some other methods and attributes you may wish to override. This list is only a summary, however, and does not include every method that can be overridden. You should consult the docstrings and source code for additional information before attempting to create a customized *note BaseHandler: 2917. subclass. Attributes and methods for customizing the WSGI environment: -- Attribute: wsgi_multithread The value to be used for the ‘wsgi.multithread’ environment variable. It defaults to true in *note BaseHandler: 2917, but may have a different default (or be set by the constructor) in the other subclasses. -- Attribute: wsgi_multiprocess The value to be used for the ‘wsgi.multiprocess’ environment variable. It defaults to true in *note BaseHandler: 2917, but may have a different default (or be set by the constructor) in the other subclasses. -- Attribute: wsgi_run_once The value to be used for the ‘wsgi.run_once’ environment variable. It defaults to false in *note BaseHandler: 2917, but *note CGIHandler: 2913. sets it to true by default. -- Attribute: os_environ The default environment variables to be included in every request’s WSGI environment. By default, this is a copy of ‘os.environ’ at the time that *note wsgiref.handlers: 12d. was imported, but subclasses can either create their own at the class or instance level. Note that the dictionary should be considered read-only, since the default value is shared between multiple classes and instances. -- Attribute: server_software If the *note origin_server: 2923. attribute is set, this attribute’s value is used to set the default ‘SERVER_SOFTWARE’ WSGI environment variable, and also to set a default ‘Server:’ header in HTTP responses. It is ignored for handlers (such as *note BaseCGIHandler: 2914. and *note CGIHandler: 2913.) that are not HTTP origin servers. Changed in version 3.3: The term “Python” is replaced with implementation specific term like “CPython”, “Jython” etc. -- Method: get_scheme () Return the URL scheme being used for the current request. The default implementation uses the ‘guess_scheme()’ function from *note wsgiref.util: 130. to guess whether the scheme should be “http” or “https”, based on the current request’s ‘environ’ variables. -- Method: setup_environ () Set the ‘environ’ attribute to a fully-populated WSGI environment. The default implementation uses all of the above methods and attributes, plus the *note get_stdin(): 291b, *note get_stderr(): 291c, and *note add_cgi_vars(): 291d. methods and the *note wsgi_file_wrapper: 2926. attribute. It also inserts a ‘SERVER_SOFTWARE’ key if not present, as long as the *note origin_server: 2923. attribute is a true value and the *note server_software: 2922. attribute is set. Methods and attributes for customizing exception handling: -- Method: log_exception (exc_info) Log the `exc_info' tuple in the server log. `exc_info' is a ‘(type, value, traceback)’ tuple. The default implementation simply writes the traceback to the request’s ‘wsgi.errors’ stream and flushes it. Subclasses can override this method to change the format or retarget the output, mail the traceback to an administrator, or whatever other action may be deemed suitable. -- Attribute: traceback_limit The maximum number of frames to include in tracebacks output by the default *note log_exception(): 2927. method. If ‘None’, all frames are included. -- Method: error_output (environ, start_response) This method is a WSGI application to generate an error page for the user. It is only invoked if an error occurs before headers are sent to the client. This method can access the current error information using ‘sys.exc_info()’, and should pass that information to `start_response' when calling it (as described in the “Error Handling” section of PEP 3333(1)). The default implementation just uses the *note error_status: 292a, *note error_headers: 292b, and *note error_body: 292c. attributes to generate an output page. Subclasses can override this to produce more dynamic error output. Note, however, that it’s not recommended from a security perspective to spit out diagnostics to any old user; ideally, you should have to do something special to enable diagnostic output, which is why the default implementation doesn’t include any. -- Attribute: error_status The HTTP status used for error responses. This should be a status string as defined in PEP 3333(2); it defaults to a 500 code and message. -- Attribute: error_headers The HTTP headers used for error responses. This should be a list of WSGI response headers (‘(name, value)’ tuples), as described in PEP 3333(3). The default list just sets the content type to ‘text/plain’. -- Attribute: error_body The error response body. This should be an HTTP response body bytestring. It defaults to the plain text, “A server error occurred. Please contact the administrator.” Methods and attributes for PEP 3333(4)’s “Optional Platform-Specific File Handling” feature: -- Attribute: wsgi_file_wrapper A ‘wsgi.file_wrapper’ factory, or ‘None’. The default value of this attribute is the *note wsgiref.util.FileWrapper: 27e. class. -- Method: sendfile () Override to implement platform-specific file transmission. This method is called only if the application’s return value is an instance of the class specified by the *note wsgi_file_wrapper: 2926. attribute. It should return a true value if it was able to successfully transmit the file, so that the default transmission code will not be executed. The default implementation of this method just returns a false value. Miscellaneous methods and attributes: -- Attribute: origin_server This attribute should be set to a true value if the handler’s *note _write(): 2919. and *note _flush(): 291a. are being used to communicate directly to the client, rather than via a CGI-like gateway protocol that wants the HTTP status in a special ‘Status:’ header. This attribute’s default value is true in *note BaseHandler: 2917, but false in *note BaseCGIHandler: 2914. and *note CGIHandler: 2913. -- Attribute: http_version If *note origin_server: 2923. is true, this string attribute is used to set the HTTP version of the response set to the client. It defaults to ‘"1.0"’. -- Function: wsgiref.handlers.read_environ () Transcode CGI variables from ‘os.environ’ to PEP 3333(5) “bytes in unicode” strings, returning a new dictionary. This function is used by *note CGIHandler: 2913. and *note IISCGIHandler: 2915. in place of directly using ‘os.environ’, which is not necessarily WSGI-compliant on all platforms and web servers using Python 3 – specifically, ones where the OS’s actual environment is Unicode (i.e. Windows), or ones where the environment is bytes, but the system encoding used by Python to decode it is anything other than ISO-8859-1 (e.g. Unix systems using UTF-8). If you are implementing a CGI-based handler of your own, you probably want to use this routine instead of just copying values out of ‘os.environ’ directly. New in version 3.2. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3333 (2) https://www.python.org/dev/peps/pep-3333 (3) https://www.python.org/dev/peps/pep-3333 (4) https://www.python.org/dev/peps/pep-3333 (5) https://www.python.org/dev/peps/pep-3333  File: python.info, Node: Examples<20>, Prev: wsgiref handlers – server/gateway base classes, Up: wsgiref — WSGI Utilities and Reference Implementation 5.21.4.6 Examples ................. This is a working “Hello World” WSGI application: from wsgiref.simple_server import make_server # Every WSGI application must have an application object - a callable # object that accepts two arguments. For that purpose, we're going to # use a function (note that you're not limited to a function, you can # use a class for example). The first argument passed to the function # is a dictionary containing CGI-style environment variables and the # second variable is the callable object. def hello_world_app(environ, start_response): status = '200 OK' # HTTP Status headers = [('Content-type', 'text/plain; charset=utf-8')] # HTTP Headers start_response(status, headers) # The returned object is going to be printed return [b"Hello World"] with make_server('', 8000, hello_world_app) as httpd: print("Serving on port 8000...") # Serve until process is killed httpd.serve_forever() Example of a WSGI application serving the current directory, accept optional directory and port number (default: 8000) on the command line: #!/usr/bin/env python3 ''' Small wsgiref based web server. Takes a path to serve from and an optional port number (defaults to 8000), then tries to serve files. Mime types are guessed from the file names, 404 errors are raised if the file is not found. Used for the make serve target in Doc. ''' import sys import os import mimetypes from wsgiref import simple_server, util def app(environ, respond): fn = os.path.join(path, environ['PATH_INFO'][1:]) if '.' not in fn.split(os.path.sep)[-1]: fn = os.path.join(fn, 'index.html') type = mimetypes.guess_type(fn)[0] if os.path.exists(fn): respond('200 OK', [('Content-Type', type)]) return util.FileWrapper(open(fn, "rb")) else: respond('404 Not Found', [('Content-Type', 'text/plain')]) return [b'not found'] if __name__ == '__main__': path = sys.argv[1] if len(sys.argv) > 1 else os.getcwd() port = int(sys.argv[2]) if len(sys.argv) > 2 else 8000 httpd = simple_server.make_server('', port, app) print("Serving {} on port {}, control-C to stop".format(path, port)) try: httpd.serve_forever() except KeyboardInterrupt: print("Shutting down.") httpd.server_close()  File: python.info, Node: urllib — URL handling modules, Next: urllib request — Extensible library for opening URLs, Prev: wsgiref — WSGI Utilities and Reference Implementation, Up: Internet Protocols and Support 5.21.5 ‘urllib’ — URL handling modules -------------------------------------- `Source code:' Lib/urllib/(1) __________________________________________________________________ ‘urllib’ is a package that collects several modules for working with URLs: * *note urllib.request: 120. for opening and reading URLs * *note urllib.error: 11e. containing the exceptions raised by *note urllib.request: 120. * *note urllib.parse: 11f. for parsing URLs * *note urllib.robotparser: 122. for parsing ‘robots.txt’ files ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/urllib/  File: python.info, Node: urllib request — Extensible library for opening URLs, Next: urllib response — Response classes used by urllib, Prev: urllib — URL handling modules, Up: Internet Protocols and Support 5.21.6 ‘urllib.request’ — Extensible library for opening URLs ------------------------------------------------------------- `Source code:' Lib/urllib/request.py(1) __________________________________________________________________ The *note urllib.request: 120. module defines functions and classes which help in opening URLs (mostly HTTP) in a complex world — basic and digest authentication, redirections, cookies and more. See also ........ The Requests package(2) is recommended for a higher-level HTTP client interface. The *note urllib.request: 120. module defines the following functions: -- Function: urllib.request.urlopen (url, data=None[, timeout], *, cafile=None, capath=None, cadefault=False, context=None) Open the URL `url', which can be either a string or a *note Request: 8f6. object. `data' must be an object specifying additional data to be sent to the server, or ‘None’ if no such data is needed. See *note Request: 8f6. for details. urllib.request module uses HTTP/1.1 and includes ‘Connection:close’ header in its HTTP requests. The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). This actually only works for HTTP, HTTPS and FTP connections. If `context' is specified, it must be a *note ssl.SSLContext: 3e4. instance describing the various SSL options. See *note HTTPSConnection: 393. for more details. The optional `cafile' and `capath' parameters specify a set of trusted CA certificates for HTTPS requests. `cafile' should point to a single file containing a bundle of CA certificates, whereas `capath' should point to a directory of hashed certificate files. More information can be found in *note ssl.SSLContext.load_verify_locations(): 7eb. The `cadefault' parameter is ignored. This function always returns an object which can work as a *note context manager: 568. and has methods such as * ‘geturl()’ — return the URL of the resource retrieved, commonly used to determine if a redirect was followed * ‘info()’ — return the meta-information of the page, such as headers, in the form of an *note email.message_from_string(): 2516. instance (see Quick Reference to HTTP Headers(3)) * ‘getcode()’ – return the HTTP status code of the response. For HTTP and HTTPS URLs, this function returns a *note http.client.HTTPResponse: a11. object slightly modified. In addition to the three new methods above, the msg attribute contains the same information as the *note reason: 2934. attribute — the reason phrase returned by server — instead of the response headers as it is specified in the documentation for *note HTTPResponse: a11. For FTP, file, and data URLs and requests explicitly handled by legacy *note URLopener: 2935. and *note FancyURLopener: 2936. classes, this function returns a ‘urllib.response.addinfourl’ object. Raises *note URLError: 2937. on protocol errors. Note that ‘None’ may be returned if no handler handles the request (though the default installed global *note OpenerDirector: 2938. uses *note UnknownHandler: 2939. to ensure this never happens). In addition, if proxy settings are detected (for example, when a ‘*_proxy’ environment variable like ‘http_proxy’ is set), *note ProxyHandler: 293a. is default installed and makes sure the requests are handled through the proxy. The legacy ‘urllib.urlopen’ function from Python 2.6 and earlier has been discontinued; *note urllib.request.urlopen(): 78c. corresponds to the old ‘urllib2.urlopen’. Proxy handling, which was done by passing a dictionary parameter to ‘urllib.urlopen’, can be obtained by using *note ProxyHandler: 293a. objects. The default opener raises an *note auditing event: fd1. ‘urllib.Request’ with arguments ‘fullurl’, ‘data’, ‘headers’, ‘method’ taken from the request object. Changed in version 3.2: `cafile' and `capath' were added. Changed in version 3.2: HTTPS virtual hosts are now supported if possible (that is, if *note ssl.HAS_SNI: 23d2. is true). New in version 3.2: `data' can be an iterable object. Changed in version 3.3: `cadefault' was added. Changed in version 3.4.3: `context' was added. Deprecated since version 3.6: `cafile', `capath' and `cadefault' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. -- Function: urllib.request.install_opener (opener) Install an *note OpenerDirector: 2938. instance as the default global opener. Installing an opener is only necessary if you want urlopen to use that opener; otherwise, simply call *note OpenerDirector.open(): 8fa. instead of *note urlopen(): 78c. The code does not check for a real *note OpenerDirector: 2938, and any class with the appropriate interface will work. -- Function: urllib.request.build_opener ([handler, ...]) Return an *note OpenerDirector: 2938. instance, which chains the handlers in the order given. `handler's can be either instances of *note BaseHandler: 293d, or subclasses of *note BaseHandler: 293d. (in which case it must be possible to call the constructor without any parameters). Instances of the following classes will be in front of the `handler's, unless the `handler's contain them, instances of them or subclasses of them: *note ProxyHandler: 293a. (if proxy settings are detected), *note UnknownHandler: 2939, *note HTTPHandler: 293e, *note HTTPDefaultErrorHandler: 293f, *note HTTPRedirectHandler: 2940, *note FTPHandler: 2941, *note FileHandler: 2942, *note HTTPErrorProcessor: 2943. If the Python installation has SSL support (i.e., if the *note ssl: f3. module can be imported), *note HTTPSHandler: ba8. will also be added. A *note BaseHandler: 293d. subclass may also change its ‘handler_order’ attribute to modify its position in the handlers list. -- Function: urllib.request.pathname2url (path) Convert the pathname `path' from the local syntax for a path to the form used in the path component of a URL. This does not produce a complete URL. The return value will already be quoted using the *note quote(): 40d. function. -- Function: urllib.request.url2pathname (path) Convert the path component `path' from a percent-encoded URL to the local syntax for a path. This does not accept a complete URL. This function uses *note unquote(): 2946. to decode `path'. -- Function: urllib.request.getproxies () This helper function returns a dictionary of scheme to proxy server URL mappings. It scans the environment for variables named ‘_proxy’, in a case insensitive approach, for all operating systems first, and when it cannot find it, looks for proxy information from Mac OSX System Configuration for Mac OS X and Windows Systems Registry for Windows. If both lowercase and uppercase environment variables exist (and disagree), lowercase is preferred. Note: If the environment variable ‘REQUEST_METHOD’ is set, which usually indicates your script is running in a CGI environment, the environment variable ‘HTTP_PROXY’ (uppercase ‘_PROXY’) will be ignored. This is because that variable can be injected by a client using the “Proxy:” HTTP header. If you need to use an HTTP proxy in a CGI environment, either use ‘ProxyHandler’ explicitly, or make sure the variable name is in lowercase (or at least the ‘_proxy’ suffix). The following classes are provided: -- Class: urllib.request.Request (url, data=None, headers={}, origin_req_host=None, unverifiable=False, method=None) This class is an abstraction of a URL request. `url' should be a string containing a valid URL. `data' must be an object specifying additional data to send to the server, or ‘None’ if no such data is needed. Currently HTTP requests are the only ones that use `data'. The supported object types include bytes, file-like objects, and iterables of bytes-like objects. If no ‘Content-Length’ nor ‘Transfer-Encoding’ header field has been provided, *note HTTPHandler: 293e. will set these headers according to the type of `data'. ‘Content-Length’ will be used to send bytes objects, while ‘Transfer-Encoding: chunked’ as specified in RFC 7230(4), Section 3.3.1 will be used to send files and other iterables. For an HTTP POST request method, `data' should be a buffer in the standard ‘application/x-www-form-urlencoded’ format. The *note urllib.parse.urlencode(): 78b. function takes a mapping or sequence of 2-tuples and returns an ASCII string in this format. It should be encoded to bytes before being used as the `data' parameter. `headers' should be a dictionary, and will be treated as if *note add_header(): 2948. was called with each key and value as arguments. This is often used to “spoof” the ‘User-Agent’ header value, which is used by a browser to identify itself – some HTTP servers only allow requests coming from common browsers as opposed to scripts. For example, Mozilla Firefox may identify itself as ‘"Mozilla/5.0 (X11; U; Linux i686) Gecko/20071127 Firefox/2.0.0.11"’, while *note urllib: 11d.’s default user agent string is ‘"Python-urllib/2.6"’ (on Python 2.6). An appropriate ‘Content-Type’ header should be included if the `data' argument is present. If this header has not been provided and `data' is not None, ‘Content-Type: application/x-www-form-urlencoded’ will be added as a default. The next two arguments are only of interest for correct handling of third-party HTTP cookies: `origin_req_host' should be the request-host of the origin transaction, as defined by RFC 2965(5). It defaults to ‘http.cookiejar.request_host(self)’. This is the host name or IP address of the original request that was initiated by the user. For example, if the request is for an image in an HTML document, this should be the request-host of the request for the page containing the image. `unverifiable' should indicate whether the request is unverifiable, as defined by RFC 2965(6). It defaults to ‘False’. An unverifiable request is one whose URL the user did not have the option to approve. For example, if the request is for an image in an HTML document, and the user had no option to approve the automatic fetching of the image, this should be true. `method' should be a string that indicates the HTTP request method that will be used (e.g. ‘'HEAD'’). If provided, its value is stored in the *note method: 8f7. attribute and is used by *note get_method(): ac1. The default is ‘'GET'’ if `data' is ‘None’ or ‘'POST'’ otherwise. Subclasses may indicate a different default method by setting the *note method: 8f7. attribute in the class itself. Note: The request will not work as expected if the data object is unable to deliver its content more than once (e.g. a file or an iterable that can produce the content only once) and the request is retried for HTTP redirects or authentication. The `data' is sent to the HTTP server right away after the headers. There is no support for a 100-continue expectation in the library. Changed in version 3.3: *note Request.method: 8f7. argument is added to the Request class. Changed in version 3.4: Default *note Request.method: 8f7. may be indicated at the class level. Changed in version 3.6: Do not raise an error if the ‘Content-Length’ has not been provided and `data' is neither ‘None’ nor a bytes object. Fall back to use chunked transfer encoding instead. -- Class: urllib.request.OpenerDirector The *note OpenerDirector: 2938. class opens URLs via *note BaseHandler: 293d.s chained together. It manages the chaining of handlers, and recovery from errors. -- Class: urllib.request.BaseHandler This is the base class for all registered handlers — and handles only the simple mechanics of registration. -- Class: urllib.request.HTTPDefaultErrorHandler A class which defines a default handler for HTTP error responses; all responses are turned into *note HTTPError: 8fc. exceptions. -- Class: urllib.request.HTTPRedirectHandler A class to handle redirections. -- Class: urllib.request.HTTPCookieProcessor (cookiejar=None) A class to handle HTTP Cookies. -- Class: urllib.request.ProxyHandler (proxies=None) Cause requests to go through a proxy. If `proxies' is given, it must be a dictionary mapping protocol names to URLs of proxies. The default is to read the list of proxies from the environment variables ‘_proxy’. If no proxy environment variables are set, then in a Windows environment proxy settings are obtained from the registry’s Internet Settings section, and in a Mac OS X environment proxy information is retrieved from the OS X System Configuration Framework. To disable autodetected proxy pass an empty dictionary. The ‘no_proxy’ environment variable can be used to specify hosts which shouldn’t be reached via proxy; if set, it should be a comma-separated list of hostname suffixes, optionally with ‘:port’ appended, for example ‘cern.ch,ncsa.uiuc.edu,some.host:8080’. Note: ‘HTTP_PROXY’ will be ignored if a variable ‘REQUEST_METHOD’ is set; see the documentation on *note getproxies(): 2947. -- Class: urllib.request.HTTPPasswordMgr Keep a database of ‘(realm, uri) -> (user, password)’ mappings. -- Class: urllib.request.HTTPPasswordMgrWithDefaultRealm Keep a database of ‘(realm, uri) -> (user, password)’ mappings. A realm of ‘None’ is considered a catch-all realm, which is searched if no other realm fits. -- Class: urllib.request.HTTPPasswordMgrWithPriorAuth A variant of *note HTTPPasswordMgrWithDefaultRealm: 294b. that also has a database of ‘uri -> is_authenticated’ mappings. Can be used by a BasicAuth handler to determine when to send authentication credentials immediately instead of waiting for a ‘401’ response first. New in version 3.5. -- Class: urllib.request.AbstractBasicAuthHandler (password_mgr=None) This is a mixin class that helps with HTTP authentication, both to the remote host and to a proxy. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. If `passwd_mgr' also provides ‘is_authenticated’ and ‘update_authenticated’ methods (see *note HTTPPasswordMgrWithPriorAuth Objects: 294e.), then the handler will use the ‘is_authenticated’ result for a given URI to determine whether or not to send authentication credentials with the request. If ‘is_authenticated’ returns ‘True’ for the URI, credentials are sent. If ‘is_authenticated’ is ‘False’, credentials are not sent, and then if a ‘401’ response is received the request is re-sent with the authentication credentials. If authentication succeeds, ‘update_authenticated’ is called to set ‘is_authenticated’ ‘True’ for the URI, so that subsequent requests to the URI or any of its super-URIs will automatically include the authentication credentials. New in version 3.5: Added ‘is_authenticated’ support. -- Class: urllib.request.HTTPBasicAuthHandler (password_mgr=None) Handle authentication with the remote host. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. HTTPBasicAuthHandler will raise a *note ValueError: 1fb. when presented with a wrong Authentication scheme. -- Class: urllib.request.ProxyBasicAuthHandler (password_mgr=None) Handle authentication with the proxy. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. -- Class: urllib.request.AbstractDigestAuthHandler (password_mgr=None) This is a mixin class that helps with HTTP authentication, both to the remote host and to a proxy. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. -- Class: urllib.request.HTTPDigestAuthHandler (password_mgr=None) Handle authentication with the remote host. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. When both Digest Authentication Handler and Basic Authentication Handler are both added, Digest Authentication is always tried first. If the Digest Authentication returns a 40x response again, it is sent to Basic Authentication handler to Handle. This Handler method will raise a *note ValueError: 1fb. when presented with an authentication scheme other than Digest or Basic. Changed in version 3.3: Raise *note ValueError: 1fb. on unsupported Authentication Scheme. -- Class: urllib.request.ProxyDigestAuthHandler (password_mgr=None) Handle authentication with the proxy. `password_mgr', if given, should be something that is compatible with *note HTTPPasswordMgr: 294a.; refer to section *note HTTPPasswordMgr Objects: 294d. for information on the interface that must be supported. -- Class: urllib.request.HTTPHandler A class to handle opening of HTTP URLs. -- Class: urllib.request.HTTPSHandler (debuglevel=0, context=None, check_hostname=None) A class to handle opening of HTTPS URLs. `context' and `check_hostname' have the same meaning as in *note http.client.HTTPSConnection: 393. Changed in version 3.2: `context' and `check_hostname' were added. -- Class: urllib.request.FileHandler Open local files. -- Class: urllib.request.DataHandler Open data URLs. New in version 3.4. -- Class: urllib.request.FTPHandler Open FTP URLs. -- Class: urllib.request.CacheFTPHandler Open FTP URLs, keeping a cache of open FTP connections to minimize delays. -- Class: urllib.request.UnknownHandler A catch-all class to handle unknown URLs. -- Class: urllib.request.HTTPErrorProcessor Process HTTP error responses. * Menu: * Request Objects:: * OpenerDirector Objects:: * BaseHandler Objects:: * HTTPRedirectHandler Objects:: * HTTPCookieProcessor Objects:: * ProxyHandler Objects:: * HTTPPasswordMgr Objects:: * HTTPPasswordMgrWithPriorAuth Objects:: * AbstractBasicAuthHandler Objects:: * HTTPBasicAuthHandler Objects:: * ProxyBasicAuthHandler Objects:: * AbstractDigestAuthHandler Objects:: * HTTPDigestAuthHandler Objects:: * ProxyDigestAuthHandler Objects:: * HTTPHandler Objects:: * HTTPSHandler Objects:: * FileHandler Objects:: * DataHandler Objects:: * FTPHandler Objects:: * CacheFTPHandler Objects:: * UnknownHandler Objects:: * HTTPErrorProcessor Objects:: * Examples: Examples<21>. * Legacy interface:: * urllib.request Restrictions: urllib request Restrictions. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/urllib/request.py (2) https://requests.readthedocs.io/en/master/ (3) http://jkorpela.fi/http.html (4) https://tools.ietf.org/html/rfc7230.html (5) https://tools.ietf.org/html/rfc2965.html (6) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: Request Objects, Next: OpenerDirector Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.1 Request Objects ........................ The following methods describe *note Request: 8f6.’s public interface, and so all may be overridden in subclasses. It also defines several public attributes that can be used by clients to inspect the parsed request. -- Attribute: Request.full_url The original URL passed to the constructor. Changed in version 3.4. Request.full_url is a property with setter, getter and a deleter. Getting *note full_url: 8f8. returns the original request URL with the fragment, if it was present. -- Attribute: Request.type The URI scheme. -- Attribute: Request.host The URI authority, typically a host, but may also contain a port separated by a colon. -- Attribute: Request.origin_req_host The original host for the request, without port. -- Attribute: Request.selector The URI path. If the *note Request: 8f6. uses a proxy, then selector will be the full URL that is passed to the proxy. -- Attribute: Request.data The entity body for the request, or ‘None’ if not specified. Changed in version 3.4: Changing value of *note Request.data: 8f9. now deletes “Content-Length” header if it was previously set or calculated. -- Attribute: Request.unverifiable boolean, indicates whether the request is unverifiable as defined by RFC 2965(1). -- Attribute: Request.method The HTTP request method to use. By default its value is *note None: 157, which means that *note get_method(): ac1. will do its normal computation of the method to be used. Its value can be set (thus overriding the default computation in *note get_method(): ac1.) either by providing a default value by setting it at the class level in a *note Request: 8f6. subclass, or by passing a value in to the *note Request: 8f6. constructor via the `method' argument. New in version 3.3. Changed in version 3.4: A default value can now be set in subclasses; previously it could only be set via the constructor argument. -- Method: Request.get_method () Return a string indicating the HTTP request method. If *note Request.method: 8f7. is not ‘None’, return its value, otherwise return ‘'GET'’ if *note Request.data: 8f9. is ‘None’, or ‘'POST'’ if it’s not. This is only meaningful for HTTP requests. Changed in version 3.3: get_method now looks at the value of *note Request.method: 8f7. -- Method: Request.add_header (key, val) Add another header to the request. Headers are currently ignored by all handlers except HTTP handlers, where they are added to the list of headers sent to the server. Note that there cannot be more than one header with the same name, and later calls will overwrite previous calls in case the `key' collides. Currently, this is no loss of HTTP functionality, since all headers which have meaning when used more than once have a (header-specific) way of gaining the same functionality using only one header. -- Method: Request.add_unredirected_header (key, header) Add a header that will not be added to a redirected request. -- Method: Request.has_header (header) Return whether the instance has the named header (checks both regular and unredirected). -- Method: Request.remove_header (header) Remove named header from the request instance (both from regular and unredirected headers). New in version 3.4. -- Method: Request.get_full_url () Return the URL given in the constructor. Changed in version 3.4. Returns *note Request.full_url: 8f8. -- Method: Request.set_proxy (host, type) Prepare the request by connecting to a proxy server. The `host' and `type' will replace those of the instance, and the instance’s selector will be the original URL given in the constructor. -- Method: Request.get_header (header_name, default=None) Return the value of the given header. If the header is not present, return the default value. -- Method: Request.header_items () Return a list of tuples (header_name, header_value) of the Request headers. Changed in version 3.4: The request methods add_data, has_data, get_data, get_type, get_host, get_selector, get_origin_req_host and is_unverifiable that were deprecated since 3.3 have been removed. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: OpenerDirector Objects, Next: BaseHandler Objects, Prev: Request Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.2 OpenerDirector Objects ............................... *note OpenerDirector: 2938. instances have the following methods: -- Method: OpenerDirector.add_handler (handler) `handler' should be an instance of *note BaseHandler: 293d. The following methods are searched, and added to the possible chains (note that HTTP errors are a special case). Note that, in the following, `protocol' should be replaced with the actual protocol to handle, for example ‘http_response()’ would be the HTTP protocol response handler. Also `type' should be replaced with the actual HTTP code, for example ‘http_error_404()’ would handle HTTP 404 errors. * ‘_open()’ — signal that the handler knows how to open `protocol' URLs. See *note BaseHandler._open(): 2965. for more information. * ‘http_error_()’ — signal that the handler knows how to handle HTTP errors with HTTP error code `type'. See *note BaseHandler.http_error_(): 2966. for more information. * ‘_error()’ — signal that the handler knows how to handle errors from (non-‘http’) `protocol'. * ‘_request()’ — signal that the handler knows how to pre-process `protocol' requests. See *note BaseHandler._request(): 2967. for more information. * ‘_response()’ — signal that the handler knows how to post-process `protocol' responses. See *note BaseHandler._response(): 2968. for more information. -- Method: OpenerDirector.open (url, data=None[, timeout]) Open the given `url' (which can be a request object or a string), optionally passing the given `data'. Arguments, return values and exceptions raised are the same as those of *note urlopen(): 78c. (which simply calls the *note open(): 4f0. method on the currently installed global *note OpenerDirector: 2938.). The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). The timeout feature actually works only for HTTP, HTTPS and FTP connections). -- Method: OpenerDirector.error (proto, *args) Handle an error of the given protocol. This will call the registered error handlers for the given protocol with the given arguments (which are protocol specific). The HTTP protocol is a special case which uses the HTTP response code to determine the specific error handler; refer to the ‘http_error_()’ methods of the handler classes. Return values and exceptions raised are the same as those of *note urlopen(): 78c. OpenerDirector objects open URLs in three stages: The order in which these methods are called within each stage is determined by sorting the handler instances. 1. Every handler with a method named like ‘_request()’ has that method called to pre-process the request. 2. Handlers with a method named like ‘_open()’ are called to handle the request. This stage ends when a handler either returns a non-*note None: 157. value (ie. a response), or raises an exception (usually *note URLError: 2937.). Exceptions are allowed to propagate. In fact, the above algorithm is first tried for methods named ‘default_open()’. If all such methods return *note None: 157, the algorithm is repeated for methods named like ‘_open()’. If all such methods return *note None: 157, the algorithm is repeated for methods named ‘unknown_open()’. Note that the implementation of these methods may involve calls of the parent *note OpenerDirector: 2938. instance’s *note open(): 8fa. and *note error(): 2969. methods. 3. Every handler with a method named like ‘_response()’ has that method called to post-process the response.  File: python.info, Node: BaseHandler Objects, Next: HTTPRedirectHandler Objects, Prev: OpenerDirector Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.3 BaseHandler Objects ............................ *note BaseHandler: 293d. objects provide a couple of methods that are directly useful, and others that are meant to be used by derived classes. These are intended for direct use: -- Method: BaseHandler.add_parent (director) Add a director as parent. -- Method: BaseHandler.close () Remove any parents. The following attribute and methods should only be used by classes derived from *note BaseHandler: 293d. Note: The convention has been adopted that subclasses defining ‘_request()’ or ‘_response()’ methods are named ‘*Processor’; all others are named ‘*Handler’. -- Attribute: BaseHandler.parent A valid *note OpenerDirector: 2938, which can be used to open using a different protocol, or handle errors. -- Method: BaseHandler.default_open (req) This method is `not' defined in *note BaseHandler: 293d, but subclasses should define it if they want to catch all URLs. This method, if implemented, will be called by the parent *note OpenerDirector: 2938. It should return a file-like object as described in the return value of the *note open(): 4f0. of *note OpenerDirector: 2938, or ‘None’. It should raise *note URLError: 2937, unless a truly exceptional thing happens (for example, *note MemoryError: 13af. should not be mapped to ‘URLError’). This method will be called before any protocol-specific open method. -- Method: BaseHandler._open(req) This method is `not' defined in *note BaseHandler: 293d, but subclasses should define it if they want to handle URLs with the given protocol. This method, if defined, will be called by the parent *note OpenerDirector: 2938. Return values should be the same as for ‘default_open()’. -- Method: BaseHandler.unknown_open (req) This method is `not' defined in *note BaseHandler: 293d, but subclasses should define it if they want to catch all URLs with no specific registered handler to open it. This method, if implemented, will be called by the *note parent: 296e. *note OpenerDirector: 2938. Return values should be the same as for *note default_open(): 296f. -- Method: BaseHandler.http_error_default (req, fp, code, msg, hdrs) This method is `not' defined in *note BaseHandler: 293d, but subclasses should override it if they intend to provide a catch-all for otherwise unhandled HTTP errors. It will be called automatically by the *note OpenerDirector: 2938. getting the error, and should not normally be called in other circumstances. `req' will be a *note Request: 8f6. object, `fp' will be a file-like object with the HTTP error body, `code' will be the three-digit code of the error, `msg' will be the user-visible explanation of the code and `hdrs' will be a mapping object with the headers of the error. Return values and exceptions raised should be the same as those of *note urlopen(): 78c. -- Method: BaseHandler.http_error_(req, fp, code, msg, hdrs) `nnn' should be a three-digit HTTP error code. This method is also not defined in *note BaseHandler: 293d, but will be called, if it exists, on an instance of a subclass, when an HTTP error with code `nnn' occurs. Subclasses should override this method to handle specific HTTP errors. Arguments, return values and exceptions raised should be the same as for ‘http_error_default()’. -- Method: BaseHandler._request(req) This method is `not' defined in *note BaseHandler: 293d, but subclasses should define it if they want to pre-process requests of the given protocol. This method, if defined, will be called by the parent *note OpenerDirector: 2938. `req' will be a *note Request: 8f6. object. The return value should be a *note Request: 8f6. object. -- Method: BaseHandler._response(req, response) This method is `not' defined in *note BaseHandler: 293d, but subclasses should define it if they want to post-process responses of the given protocol. This method, if defined, will be called by the parent *note OpenerDirector: 2938. `req' will be a *note Request: 8f6. object. `response' will be an object implementing the same interface as the return value of *note urlopen(): 78c. The return value should implement the same interface as the return value of *note urlopen(): 78c.  File: python.info, Node: HTTPRedirectHandler Objects, Next: HTTPCookieProcessor Objects, Prev: BaseHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.4 HTTPRedirectHandler Objects .................................... Note: Some HTTP redirections require action from this module’s client code. If this is the case, *note HTTPError: 8fc. is raised. See RFC 2616(1) for details of the precise meanings of the various redirection codes. An ‘HTTPError’ exception raised as a security consideration if the HTTPRedirectHandler is presented with a redirected URL which is not an HTTP, HTTPS or FTP URL. -- Method: HTTPRedirectHandler.redirect_request (req, fp, code, msg, hdrs, newurl) Return a *note Request: 8f6. or ‘None’ in response to a redirect. This is called by the default implementations of the ‘http_error_30*()’ methods when a redirection is received from the server. If a redirection should take place, return a new *note Request: 8f6. to allow ‘http_error_30*()’ to perform the redirect to `newurl'. Otherwise, raise *note HTTPError: 8fc. if no other handler should try to handle this URL, or return ‘None’ if you can’t but another handler might. Note: The default implementation of this method does not strictly follow RFC 2616(2), which says that 301 and 302 responses to ‘POST’ requests must not be automatically redirected without confirmation by the user. In reality, browsers do allow automatic redirection of these responses, changing the POST to a ‘GET’, and the default implementation reproduces this behavior. -- Method: HTTPRedirectHandler.http_error_301 (req, fp, code, msg, hdrs) Redirect to the ‘Location:’ or ‘URI:’ URL. This method is called by the parent *note OpenerDirector: 2938. when getting an HTTP ‘moved permanently’ response. -- Method: HTTPRedirectHandler.http_error_302 (req, fp, code, msg, hdrs) The same as *note http_error_301(): 2975, but called for the ‘found’ response. -- Method: HTTPRedirectHandler.http_error_303 (req, fp, code, msg, hdrs) The same as *note http_error_301(): 2975, but called for the ‘see other’ response. -- Method: HTTPRedirectHandler.http_error_307 (req, fp, code, msg, hdrs) The same as *note http_error_301(): 2975, but called for the ‘temporary redirect’ response. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2616.html (2) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: HTTPCookieProcessor Objects, Next: ProxyHandler Objects, Prev: HTTPRedirectHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.5 HTTPCookieProcessor Objects .................................... *note HTTPCookieProcessor: 2949. instances have one attribute: -- Attribute: HTTPCookieProcessor.cookiejar The *note http.cookiejar.CookieJar: 297c. in which cookies are stored.  File: python.info, Node: ProxyHandler Objects, Next: HTTPPasswordMgr Objects, Prev: HTTPCookieProcessor Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.6 ProxyHandler Objects ............................. -- Method: ProxyHandler._open(request) The *note ProxyHandler: 293a. will have a method ‘_open()’ for every `protocol' which has a proxy in the `proxies' dictionary given in the constructor. The method will modify requests to go through the proxy, by calling ‘request.set_proxy()’, and call the next handler in the chain to actually execute the protocol.  File: python.info, Node: HTTPPasswordMgr Objects, Next: HTTPPasswordMgrWithPriorAuth Objects, Prev: ProxyHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.7 HTTPPasswordMgr Objects ................................ These methods are available on *note HTTPPasswordMgr: 294a. and *note HTTPPasswordMgrWithDefaultRealm: 294b. objects. -- Method: HTTPPasswordMgr.add_password (realm, uri, user, passwd) `uri' can be either a single URI, or a sequence of URIs. `realm', `user' and `passwd' must be strings. This causes ‘(user, passwd)’ to be used as authentication tokens when authentication for `realm' and a super-URI of any of the given URIs is given. -- Method: HTTPPasswordMgr.find_user_password (realm, authuri) Get user/password for given realm and URI, if any. This method will return ‘(None, None)’ if there is no matching user/password. For *note HTTPPasswordMgrWithDefaultRealm: 294b. objects, the realm ‘None’ will be searched if the given `realm' has no matching user/password.  File: python.info, Node: HTTPPasswordMgrWithPriorAuth Objects, Next: AbstractBasicAuthHandler Objects, Prev: HTTPPasswordMgr Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.8 HTTPPasswordMgrWithPriorAuth Objects ............................................. This password manager extends *note HTTPPasswordMgrWithDefaultRealm: 294b. to support tracking URIs for which authentication credentials should always be sent. -- Method: HTTPPasswordMgrWithPriorAuth.add_password (realm, uri, user, passwd, is_authenticated=False) `realm', `uri', `user', `passwd' are as for *note HTTPPasswordMgr.add_password(): 2980. `is_authenticated' sets the initial value of the ‘is_authenticated’ flag for the given URI or list of URIs. If `is_authenticated' is specified as ‘True’, `realm' is ignored. -- Method: HTTPPasswordMgrWithPriorAuth.find_user_password (realm, authuri) Same as for *note HTTPPasswordMgrWithDefaultRealm: 294b. objects -- Method: HTTPPasswordMgrWithPriorAuth.update_authenticated (self, uri, is_authenticated=False) Update the ‘is_authenticated’ flag for the given `uri' or list of URIs. -- Method: HTTPPasswordMgrWithPriorAuth.is_authenticated (self, authuri) Returns the current state of the ‘is_authenticated’ flag for the given URI.  File: python.info, Node: AbstractBasicAuthHandler Objects, Next: HTTPBasicAuthHandler Objects, Prev: HTTPPasswordMgrWithPriorAuth Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.9 AbstractBasicAuthHandler Objects ......................................... -- Method: AbstractBasicAuthHandler.http_error_auth_reqed (authreq, host, req, headers) Handle an authentication request by getting a user/password pair, and re-trying the request. `authreq' should be the name of the header where the information about the realm is included in the request, `host' specifies the URL and path to authenticate for, `req' should be the (failed) *note Request: 8f6. object, and `headers' should be the error headers. `host' is either an authority (e.g. ‘"python.org"’) or a URL containing an authority component (e.g. ‘"http://python.org/"’). In either case, the authority must not contain a userinfo component (so, ‘"python.org"’ and ‘"python.org:80"’ are fine, ‘"joe:password@python.org"’ is not).  File: python.info, Node: HTTPBasicAuthHandler Objects, Next: ProxyBasicAuthHandler Objects, Prev: AbstractBasicAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.10 HTTPBasicAuthHandler Objects ...................................... -- Method: HTTPBasicAuthHandler.http_error_401 (req, fp, code, msg, hdrs) Retry the request with authentication information, if available.  File: python.info, Node: ProxyBasicAuthHandler Objects, Next: AbstractDigestAuthHandler Objects, Prev: HTTPBasicAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.11 ProxyBasicAuthHandler Objects ....................................... -- Method: ProxyBasicAuthHandler.http_error_407 (req, fp, code, msg, hdrs) Retry the request with authentication information, if available.  File: python.info, Node: AbstractDigestAuthHandler Objects, Next: HTTPDigestAuthHandler Objects, Prev: ProxyBasicAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.12 AbstractDigestAuthHandler Objects ........................................... -- Method: AbstractDigestAuthHandler.http_error_auth_reqed (authreq, host, req, headers) `authreq' should be the name of the header where the information about the realm is included in the request, `host' should be the host to authenticate to, `req' should be the (failed) *note Request: 8f6. object, and `headers' should be the error headers.  File: python.info, Node: HTTPDigestAuthHandler Objects, Next: ProxyDigestAuthHandler Objects, Prev: AbstractDigestAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.13 HTTPDigestAuthHandler Objects ....................................... -- Method: HTTPDigestAuthHandler.http_error_401 (req, fp, code, msg, hdrs) Retry the request with authentication information, if available.  File: python.info, Node: ProxyDigestAuthHandler Objects, Next: HTTPHandler Objects, Prev: HTTPDigestAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.14 ProxyDigestAuthHandler Objects ........................................ -- Method: ProxyDigestAuthHandler.http_error_407 (req, fp, code, msg, hdrs) Retry the request with authentication information, if available.  File: python.info, Node: HTTPHandler Objects, Next: HTTPSHandler Objects, Prev: ProxyDigestAuthHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.15 HTTPHandler Objects ............................. -- Method: HTTPHandler.http_open (req) Send an HTTP request, which can be either GET or POST, depending on ‘req.has_data()’.  File: python.info, Node: HTTPSHandler Objects, Next: FileHandler Objects, Prev: HTTPHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.16 HTTPSHandler Objects .............................. -- Method: HTTPSHandler.https_open (req) Send an HTTPS request, which can be either GET or POST, depending on ‘req.has_data()’.  File: python.info, Node: FileHandler Objects, Next: DataHandler Objects, Prev: HTTPSHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.17 FileHandler Objects ............................. -- Method: FileHandler.file_open (req) Open the file locally, if there is no host name, or the host name is ‘'localhost'’. Changed in version 3.2: This method is applicable only for local hostnames. When a remote hostname is given, an *note URLError: 2937. is raised.  File: python.info, Node: DataHandler Objects, Next: FTPHandler Objects, Prev: FileHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.18 DataHandler Objects ............................. -- Method: DataHandler.data_open (req) Read a data URL. This kind of URL contains the content encoded in the URL itself. The data URL syntax is specified in RFC 2397(1). This implementation ignores white spaces in base64 encoded data URLs so the URL may be wrapped in whatever source file it comes from. But even though some browsers don’t mind about a missing padding at the end of a base64 encoded data URL, this implementation will raise an *note ValueError: 1fb. in that case. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2397.html  File: python.info, Node: FTPHandler Objects, Next: CacheFTPHandler Objects, Prev: DataHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.19 FTPHandler Objects ............................ -- Method: FTPHandler.ftp_open (req) Open the FTP file indicated by `req'. The login is always done with empty username and password.  File: python.info, Node: CacheFTPHandler Objects, Next: UnknownHandler Objects, Prev: FTPHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.20 CacheFTPHandler Objects ................................. *note CacheFTPHandler: 2954. objects are *note FTPHandler: 2941. objects with the following additional methods: -- Method: CacheFTPHandler.setTimeout (t) Set timeout of connections to `t' seconds. -- Method: CacheFTPHandler.setMaxConns (m) Set maximum number of cached connections to `m'.  File: python.info, Node: UnknownHandler Objects, Next: HTTPErrorProcessor Objects, Prev: CacheFTPHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.21 UnknownHandler Objects ................................ -- Method: UnknownHandler.unknown_open () Raise a *note URLError: 2937. exception.  File: python.info, Node: HTTPErrorProcessor Objects, Next: Examples<21>, Prev: UnknownHandler Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.22 HTTPErrorProcessor Objects .................................... -- Method: HTTPErrorProcessor.http_response (request, response) Process HTTP error responses. For 200 error codes, the response object is returned immediately. For non-200 error codes, this simply passes the job on to the ‘http_error_()’ handler methods, via *note OpenerDirector.error(): 2969. Eventually, *note HTTPDefaultErrorHandler: 293f. will raise an *note HTTPError: 8fc. if no other handler handles the error. -- Method: HTTPErrorProcessor.https_response (request, response) Process HTTPS error responses. The behavior is same as *note http_response(): 29b1.  File: python.info, Node: Examples<21>, Next: Legacy interface, Prev: HTTPErrorProcessor Objects, Up: urllib request — Extensible library for opening URLs 5.21.6.23 Examples .................. In addition to the examples below, more examples are given in *note HOWTO Fetch Internet Resources Using The urllib Package: 29b5. This example gets the python.org main page and displays the first 300 bytes of it. >>> import urllib.request >>> with urllib.request.urlopen('http://www.python.org/') as f: ... print(f.read(300)) ... b'\n\n\n\n\n\n \n Python Programming ' Note that urlopen returns a bytes object. This is because there is no way for urlopen to automatically determine the encoding of the byte stream it receives from the HTTP server. In general, a program will decode the returned bytes object to string once it determines or guesses the appropriate encoding. The following W3C document, ‘https://www.w3.org/International/O-charset’, lists the various ways in which an (X)HTML or an XML document could have specified its encoding information. As the python.org website uses `utf-8' encoding as specified in its meta tag, we will use the same for decoding the bytes object. >>> with urllib.request.urlopen('http://www.python.org/') as f: ... print(f.read(100).decode('utf-8')) ... <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtm It is also possible to achieve the same result without using the *note context manager: 568. approach. >>> import urllib.request >>> f = urllib.request.urlopen('http://www.python.org/') >>> print(f.read(100).decode('utf-8')) <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtm In the following example, we are sending a data-stream to the stdin of a CGI and reading the data it returns to us. Note that this example will only work when the Python installation supports SSL. >>> import urllib.request >>> req = urllib.request.Request(url='https://localhost/cgi-bin/test.cgi', ... data=b'This data is passed to stdin of the CGI') >>> with urllib.request.urlopen(req) as f: ... print(f.read().decode('utf-8')) ... Got Data: "This data is passed to stdin of the CGI" The code for the sample CGI used in the above example is: #!/usr/bin/env python import sys data = sys.stdin.read() print('Content-type: text/plain\n\nGot Data: "%s"' % data) Here is an example of doing a ‘PUT’ request using *note Request: 8f6.: import urllib.request DATA = b'some data' req = urllib.request.Request(url='http://localhost:8080', data=DATA,method='PUT') with urllib.request.urlopen(req) as f: pass print(f.status) print(f.reason) Use of Basic HTTP Authentication: import urllib.request # Create an OpenerDirector with support for Basic HTTP Authentication... auth_handler = urllib.request.HTTPBasicAuthHandler() auth_handler.add_password(realm='PDQ Application', uri='https://mahler:8092/site-updates.py', user='klem', passwd='kadidd!ehopper') opener = urllib.request.build_opener(auth_handler) # ...and install it globally so it can be used with urlopen. urllib.request.install_opener(opener) urllib.request.urlopen('http://www.example.com/login.html') *note build_opener(): 293c. provides many handlers by default, including a *note ProxyHandler: 293a. By default, *note ProxyHandler: 293a. uses the environment variables named ‘<scheme>_proxy’, where ‘<scheme>’ is the URL scheme involved. For example, the ‘http_proxy’ environment variable is read to obtain the HTTP proxy’s URL. This example replaces the default *note ProxyHandler: 293a. with one that uses programmatically-supplied proxy URLs, and adds proxy authorization support with *note ProxyBasicAuthHandler: 2950. proxy_handler = urllib.request.ProxyHandler({'http': 'http://www.example.com:3128/'}) proxy_auth_handler = urllib.request.ProxyBasicAuthHandler() proxy_auth_handler.add_password('realm', 'host', 'username', 'password') opener = urllib.request.build_opener(proxy_handler, proxy_auth_handler) # This time, rather than install the OpenerDirector, we use it directly: opener.open('http://www.example.com/login.html') Adding HTTP headers: Use the `headers' argument to the *note Request: 8f6. constructor, or: import urllib.request req = urllib.request.Request('http://www.example.com/') req.add_header('Referer', 'http://www.python.org/') # Customize the default User-Agent header value: req.add_header('User-Agent', 'urllib-example/0.1 (Contact: . . .)') r = urllib.request.urlopen(req) *note OpenerDirector: 2938. automatically adds a ‘User-Agent’ header to every *note Request: 8f6. To change this: import urllib.request opener = urllib.request.build_opener() opener.addheaders = [('User-agent', 'Mozilla/5.0')] opener.open('http://www.example.com/') Also, remember that a few standard headers (‘Content-Length’, ‘Content-Type’ and ‘Host’) are added when the *note Request: 8f6. is passed to *note urlopen(): 78c. (or *note OpenerDirector.open(): 8fa.). Here is an example session that uses the ‘GET’ method to retrieve a URL containing parameters: >>> import urllib.request >>> import urllib.parse >>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0}) >>> url = "http://www.musi-cal.com/cgi-bin/query?%s" % params >>> with urllib.request.urlopen(url) as f: ... print(f.read().decode('utf-8')) ... The following example uses the ‘POST’ method instead. Note that params output from urlencode is encoded to bytes before it is sent to urlopen as data: >>> import urllib.request >>> import urllib.parse >>> data = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0}) >>> data = data.encode('ascii') >>> with urllib.request.urlopen("http://requestb.in/xrbl82xr", data) as f: ... print(f.read().decode('utf-8')) ... The following example uses an explicitly specified HTTP proxy, overriding environment settings: >>> import urllib.request >>> proxies = {'http': 'http://proxy.example.com:8080/'} >>> opener = urllib.request.FancyURLopener(proxies) >>> with opener.open("http://www.python.org") as f: ... f.read().decode('utf-8') ... The following example uses no proxies at all, overriding environment settings: >>> import urllib.request >>> opener = urllib.request.FancyURLopener({}) >>> with opener.open("http://www.python.org/") as f: ... f.read().decode('utf-8') ...  File: python.info, Node: Legacy interface, Next: urllib request Restrictions, Prev: Examples<21>, Up: urllib request — Extensible library for opening URLs 5.21.6.24 Legacy interface .......................... The following functions and classes are ported from the Python 2 module ‘urllib’ (as opposed to ‘urllib2’). They might become deprecated at some point in the future. -- Function: urllib.request.urlretrieve (url, filename=None, reporthook=None, data=None) Copy a network object denoted by a URL to a local file. If the URL points to a local file, the object will not be copied unless filename is supplied. Return a tuple ‘(filename, headers)’ where `filename' is the local file name under which the object can be found, and `headers' is whatever the ‘info()’ method of the object returned by *note urlopen(): 78c. returned (for a remote object). Exceptions are the same as for *note urlopen(): 78c. The second argument, if present, specifies the file location to copy to (if absent, the location will be a tempfile with a generated name). The third argument, if present, is a callable that will be called once on establishment of the network connection and once after each block read thereafter. The callable will be passed three arguments; a count of blocks transferred so far, a block size in bytes, and the total size of the file. The third argument may be ‘-1’ on older FTP servers which do not return a file size in response to a retrieval request. The following example illustrates the most common usage scenario: >>> import urllib.request >>> local_filename, headers = urllib.request.urlretrieve('http://python.org/') >>> html = open(local_filename) >>> html.close() If the `url' uses the ‘http:’ scheme identifier, the optional `data' argument may be given to specify a ‘POST’ request (normally the request type is ‘GET’). The `data' argument must be a bytes object in standard ‘application/x-www-form-urlencoded’ format; see the *note urllib.parse.urlencode(): 78b. function. *note urlretrieve(): 29b8. will raise ‘ContentTooShortError’ when it detects that the amount of data available was less than the expected amount (which is the size reported by a `Content-Length' header). This can occur, for example, when the download is interrupted. The `Content-Length' is treated as a lower bound: if there’s more data to read, urlretrieve reads more data, but if less data is available, it raises the exception. You can still retrieve the downloaded data in this case, it is stored in the ‘content’ attribute of the exception instance. If no `Content-Length' header was supplied, urlretrieve can not check the size of the data it has downloaded, and just returns it. In this case you just have to assume that the download was successful. -- Function: urllib.request.urlcleanup () Cleans up temporary files that may have been left behind by previous calls to *note urlretrieve(): 29b8. -- Class: urllib.request.URLopener (proxies=None, **x509) Deprecated since version 3.3. Base class for opening and reading URLs. Unless you need to support opening objects using schemes other than ‘http:’, ‘ftp:’, or ‘file:’, you probably want to use *note FancyURLopener: 2936. By default, the *note URLopener: 2935. class sends a ‘User-Agent’ header of ‘urllib/VVV’, where `VVV' is the *note urllib: 11d. version number. Applications can define their own ‘User-Agent’ header by subclassing *note URLopener: 2935. or *note FancyURLopener: 2936. and setting the class attribute *note version: 29ba. to an appropriate string value in the subclass definition. The optional `proxies' parameter should be a dictionary mapping scheme names to proxy URLs, where an empty dictionary turns proxies off completely. Its default value is ‘None’, in which case environmental proxy settings will be used if present, as discussed in the definition of *note urlopen(): 78c, above. Additional keyword parameters, collected in `x509', may be used for authentication of the client when using the ‘https:’ scheme. The keywords `key_file' and `cert_file' are supported to provide an SSL key and certificate; both are needed to support client authentication. *note URLopener: 2935. objects will raise an *note OSError: 1d3. exception if the server returns an error code. -- Method: open (fullurl, data=None) Open `fullurl' using the appropriate protocol. This method sets up cache and proxy information, then calls the appropriate open method with its input arguments. If the scheme is not recognized, *note open_unknown(): 29bc. is called. The `data' argument has the same meaning as the `data' argument of *note urlopen(): 78c. This method always quotes `fullurl' using *note quote(): 40d. -- Method: open_unknown (fullurl, data=None) Overridable interface to open unknown URL types. -- Method: retrieve (url, filename=None, reporthook=None, data=None) Retrieves the contents of `url' and places it in `filename'. The return value is a tuple consisting of a local filename and either an *note email.message.Message: 541. object containing the response headers (for remote URLs) or ‘None’ (for local URLs). The caller must then open and read the contents of `filename'. If `filename' is not given and the URL refers to a local file, the input filename is returned. If the URL is non-local and `filename' is not given, the filename is the output of *note tempfile.mktemp(): 1932. with a suffix that matches the suffix of the last path component of the input URL. If `reporthook' is given, it must be a function accepting three numeric parameters: A chunk number, the maximum size chunks are read in and the total size of the download (-1 if unknown). It will be called once at the start and after each chunk of data is read from the network. `reporthook' is ignored for local URLs. If the `url' uses the ‘http:’ scheme identifier, the optional `data' argument may be given to specify a ‘POST’ request (normally the request type is ‘GET’). The `data' argument must in standard ‘application/x-www-form-urlencoded’ format; see the *note urllib.parse.urlencode(): 78b. function. -- Attribute: version Variable that specifies the user agent of the opener object. To get *note urllib: 11d. to tell servers that it is a particular user agent, set this in a subclass as a class variable or in the constructor before calling the base constructor. -- Class: urllib.request.FancyURLopener (...) Deprecated since version 3.3. *note FancyURLopener: 2936. subclasses *note URLopener: 2935. providing default handling for the following HTTP response codes: 301, 302, 303, 307 and 401. For the 30x response codes listed above, the ‘Location’ header is used to fetch the actual URL. For 401 response codes (authentication required), basic HTTP authentication is performed. For the 30x response codes, recursion is bounded by the value of the `maxtries' attribute, which defaults to 10. For all other response codes, the method ‘http_error_default()’ is called which you can override in subclasses to handle the error appropriately. Note: According to the letter of RFC 2616(1), 301 and 302 responses to POST requests must not be automatically redirected without confirmation by the user. In reality, browsers do allow automatic redirection of these responses, changing the POST to a GET, and *note urllib: 11d. reproduces this behaviour. The parameters to the constructor are the same as those for *note URLopener: 2935. Note: When performing basic authentication, a *note FancyURLopener: 2936. instance calls its *note prompt_user_passwd(): 29be. method. The default implementation asks the users for the required information on the controlling terminal. A subclass may override this method to support more appropriate behavior if needed. The *note FancyURLopener: 2936. class offers one additional method that should be overloaded to provide the appropriate behavior: -- Method: prompt_user_passwd (host, realm) Return information needed to authenticate the user at the given host in the specified security realm. The return value should be a tuple, ‘(user, password)’, which can be used for basic authentication. The implementation prompts for this information on the terminal; an application should override this method to use an appropriate interaction model in the local environment. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: urllib request Restrictions, Prev: Legacy interface, Up: urllib request — Extensible library for opening URLs 5.21.6.25 ‘urllib.request’ Restrictions ....................................... * Currently, only the following protocols are supported: HTTP (versions 0.9 and 1.0), FTP, local files, and data URLs. Changed in version 3.4: Added support for data URLs. * The caching feature of *note urlretrieve(): 29b8. has been disabled until someone finds the time to hack proper processing of Expiration time headers. * There should be a function to query whether a particular URL is in the cache. * For backward compatibility, if a URL appears to point to a local file but the file can’t be opened, the URL is re-interpreted using the FTP protocol. This can sometimes cause confusing error messages. * The *note urlopen(): 78c. and *note urlretrieve(): 29b8. functions can cause arbitrarily long delays while waiting for a network connection to be set up. This means that it is difficult to build an interactive Web client using these functions without using threads. * The data returned by *note urlopen(): 78c. or *note urlretrieve(): 29b8. is the raw data returned by the server. This may be binary data (such as an image), plain text or (for example) HTML. The HTTP protocol provides type information in the reply header, which can be inspected by looking at the ‘Content-Type’ header. If the returned data is HTML, you can use the module *note html.parser: 92. to parse it. * The code handling the FTP protocol cannot differentiate between a file and a directory. This can lead to unexpected behavior when attempting to read a URL that points to a file that is not accessible. If the URL ends in a ‘/’, it is assumed to refer to a directory and will be handled accordingly. But if an attempt to read a file leads to a 550 error (meaning the URL cannot be found or is not accessible, often for permission reasons), then the path is treated as a directory in order to handle the case when a directory is specified by a URL but the trailing ‘/’ has been left off. This can cause misleading results when you try to fetch a file whose read permissions make it inaccessible; the FTP code will try to read it, fail with a 550 error, and then perform a directory listing for the unreadable file. If fine-grained control is needed, consider using the *note ftplib: 84. module, subclassing *note FancyURLopener: 2936, or changing `_urlopener' to meet your needs.  File: python.info, Node: urllib response — Response classes used by urllib, Next: urllib parse — Parse URLs into components, Prev: urllib request — Extensible library for opening URLs, Up: Internet Protocols and Support 5.21.7 ‘urllib.response’ — Response classes used by urllib ---------------------------------------------------------- The *note urllib.response: 121. module defines functions and classes which define a minimal file like interface, including ‘read()’ and ‘readline()’. The typical response object is an addinfourl instance, which defines an ‘info()’ method and that returns headers and a ‘geturl()’ method that returns the url. Functions defined by this module are used internally by the *note urllib.request: 120. module.  File: python.info, Node: urllib parse — Parse URLs into components, Next: urllib error — Exception classes raised by urllib request, Prev: urllib response — Response classes used by urllib, Up: Internet Protocols and Support 5.21.8 ‘urllib.parse’ — Parse URLs into components -------------------------------------------------- `Source code:' Lib/urllib/parse.py(1) __________________________________________________________________ This module defines a standard interface to break Uniform Resource Locator (URL) strings up in components (addressing scheme, network location, path etc.), to combine the components back into a URL string, and to convert a “relative URL” to an absolute URL given a “base URL.” The module has been designed to match the Internet RFC on Relative Uniform Resource Locators. It supports the following URL schemes: ‘file’, ‘ftp’, ‘gopher’, ‘hdl’, ‘http’, ‘https’, ‘imap’, ‘mailto’, ‘mms’, ‘news’, ‘nntp’, ‘prospero’, ‘rsync’, ‘rtsp’, ‘rtspu’, ‘sftp’, ‘shttp’, ‘sip’, ‘sips’, ‘snews’, ‘svn’, ‘svn+ssh’, ‘telnet’, ‘wais’, ‘ws’, ‘wss’. The *note urllib.parse: 11f. module defines functions that fall into two broad categories: URL parsing and URL quoting. These are covered in detail in the following sections. * Menu: * URL Parsing:: * Parsing ASCII Encoded Bytes:: * Structured Parse Results:: * URL Quoting:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/urllib/parse.py  File: python.info, Node: URL Parsing, Next: Parsing ASCII Encoded Bytes, Up: urllib parse — Parse URLs into components 5.21.8.1 URL Parsing .................... The URL parsing functions focus on splitting a URL string into its components, or on combining URL components into a URL string. -- Function: urllib.parse.urlparse (urlstring, scheme='', allow_fragments=True) Parse a URL into six components, returning a 6-item *note named tuple: aa3. This corresponds to the general structure of a URL: ‘scheme://netloc/path;parameters?query#fragment’. Each tuple item is a string, possibly empty. The components are not broken up in smaller parts (for example, the network location is a single string), and % escapes are not expanded. The delimiters as shown above are not part of the result, except for a leading slash in the `path' component, which is retained if present. For example: >>> from urllib.parse import urlparse >>> o = urlparse('http://www.cwi.nl:80/%7Eguido/Python.html') >>> o ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html', params='', query='', fragment='') >>> o.scheme 'http' >>> o.port 80 >>> o.geturl() 'http://www.cwi.nl:80/%7Eguido/Python.html' Following the syntax specifications in RFC 1808(1), urlparse recognizes a netloc only if it is properly introduced by ‘//’. Otherwise the input is presumed to be a relative URL and thus to start with a path component. >>> from urllib.parse import urlparse >>> urlparse('//www.cwi.nl:80/%7Eguido/Python.html') ParseResult(scheme='', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html', params='', query='', fragment='') >>> urlparse('www.cwi.nl/%7Eguido/Python.html') ParseResult(scheme='', netloc='', path='www.cwi.nl/%7Eguido/Python.html', params='', query='', fragment='') >>> urlparse('help/Python.html') ParseResult(scheme='', netloc='', path='help/Python.html', params='', query='', fragment='') The `scheme' argument gives the default addressing scheme, to be used only if the URL does not specify one. It should be the same type (text or bytes) as `urlstring', except that the default value ‘''’ is always allowed, and is automatically converted to ‘b''’ if appropriate. If the `allow_fragments' argument is false, fragment identifiers are not recognized. Instead, they are parsed as part of the path, parameters or query component, and ‘fragment’ is set to the empty string in the return value. The return value is a *note named tuple: aa3, which means that its items can be accessed by index or as named attributes, which are: Attribute Index Value Value if not present --------------------------------------------------------------------------------------------- ‘scheme’ 0 URL scheme specifier `scheme' parameter ‘netloc’ 1 Network location part empty string ‘path’ 2 Hierarchical path empty string ‘params’ 3 Parameters for last path empty string element ‘query’ 4 Query component empty string ‘fragment’ 5 Fragment identifier empty string ‘username’ User name *note None: 157. ‘password’ Password *note None: 157. ‘hostname’ Host name (lower case) *note None: 157. ‘port’ Port number as integer, if *note None: 157. present Reading the ‘port’ attribute will raise a *note ValueError: 1fb. if an invalid port is specified in the URL. See section *note Structured Parse Results: 29c4. for more information on the result object. Unmatched square brackets in the ‘netloc’ attribute will raise a *note ValueError: 1fb. Characters in the ‘netloc’ attribute that decompose under NFKC normalization (as used by the IDNA encoding) into any of ‘/’, ‘?’, ‘#’, ‘@’, or ‘:’ will raise a *note ValueError: 1fb. If the URL is decomposed before parsing, no error will be raised. As is the case with all named tuples, the subclass has a few additional methods and attributes that are particularly useful. One such method is ‘_replace()’. The ‘_replace()’ method will return a new ParseResult object replacing specified fields with new values. >>> from urllib.parse import urlparse >>> u = urlparse('//www.cwi.nl:80/%7Eguido/Python.html') >>> u ParseResult(scheme='', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html', params='', query='', fragment='') >>> u._replace(scheme='http') ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html', params='', query='', fragment='') Changed in version 3.2: Added IPv6 URL parsing capabilities. Changed in version 3.3: The fragment is now parsed for all URL schemes (unless `allow_fragment' is false), in accordance with RFC 3986(2). Previously, a whitelist of schemes that support fragments existed. Changed in version 3.6: Out-of-range port numbers now raise *note ValueError: 1fb, instead of returning *note None: 157. Changed in version 3.8: Characters that affect netloc parsing under NFKC normalization will now raise *note ValueError: 1fb. -- Function: urllib.parse.parse_qs (qs, keep_blank_values=False, strict_parsing=False, encoding='utf-8', errors='replace', max_num_fields=None, separator='&') Parse a query string given as a string argument (data of type ‘application/x-www-form-urlencoded’). Data are returned as a dictionary. The dictionary keys are the unique query variable names and the values are lists of values for each name. The optional argument `keep_blank_values' is a flag indicating whether blank values in percent-encoded queries should be treated as blank strings. A true value indicates that blanks should be retained as blank strings. The default false value indicates that blank values are to be ignored and treated as if they were not included. The optional argument `strict_parsing' is a flag indicating what to do with parsing errors. If false (the default), errors are silently ignored. If true, errors raise a *note ValueError: 1fb. exception. The optional `encoding' and `errors' parameters specify how to decode percent-encoded sequences into Unicode characters, as accepted by the *note bytes.decode(): c38. method. The optional argument `max_num_fields' is the maximum number of fields to read. If set, then throws a *note ValueError: 1fb. if there are more than `max_num_fields' fields read. The optional argument `separator' is the symbol to use for separating the query arguments. It defaults to ‘&’. Use the *note urllib.parse.urlencode(): 78b. function (with the ‘doseq’ parameter set to ‘True’) to convert such dictionaries into query strings. Changed in version 3.2: Add `encoding' and `errors' parameters. Changed in version 3.8: Added `max_num_fields' parameter. Changed in version 3.8.8: Added `separator' parameter with the default value of ‘&’. Python versions earlier than Python 3.8.8 allowed using both ‘;’ and ‘&’ as query parameter separator. This has been changed to allow only a single separator key, with ‘&’ as the default separator. -- Function: urllib.parse.parse_qsl (qs, keep_blank_values=False, strict_parsing=False, encoding='utf-8', errors='replace', max_num_fields=None, separator='&') Parse a query string given as a string argument (data of type ‘application/x-www-form-urlencoded’). Data are returned as a list of name, value pairs. The optional argument `keep_blank_values' is a flag indicating whether blank values in percent-encoded queries should be treated as blank strings. A true value indicates that blanks should be retained as blank strings. The default false value indicates that blank values are to be ignored and treated as if they were not included. The optional argument `strict_parsing' is a flag indicating what to do with parsing errors. If false (the default), errors are silently ignored. If true, errors raise a *note ValueError: 1fb. exception. The optional `encoding' and `errors' parameters specify how to decode percent-encoded sequences into Unicode characters, as accepted by the *note bytes.decode(): c38. method. The optional argument `max_num_fields' is the maximum number of fields to read. If set, then throws a *note ValueError: 1fb. if there are more than `max_num_fields' fields read. The optional argument `separator' is the symbol to use for separating the query arguments. It defaults to ‘&’. Use the *note urllib.parse.urlencode(): 78b. function to convert such lists of pairs into query strings. Changed in version 3.2: Add `encoding' and `errors' parameters. Changed in version 3.8: Added `max_num_fields' parameter. Changed in version 3.8.8: Added `separator' parameter with the default value of ‘&’. Python versions earlier than Python 3.8.8 allowed using both ‘;’ and ‘&’ as query parameter separator. This has been changed to allow only a single separator key, with ‘&’ as the default separator. -- Function: urllib.parse.urlunparse (parts) Construct a URL from a tuple as returned by ‘urlparse()’. The `parts' argument can be any six-item iterable. This may result in a slightly different, but equivalent URL, if the URL that was parsed originally had unnecessary delimiters (for example, a ‘?’ with an empty query; the RFC states that these are equivalent). -- Function: urllib.parse.urlsplit (urlstring, scheme='', allow_fragments=True) This is similar to *note urlparse(): 5fa, but does not split the params from the URL. This should generally be used instead of *note urlparse(): 5fa. if the more recent URL syntax allowing parameters to be applied to each segment of the `path' portion of the URL (see RFC 2396(3)) is wanted. A separate function is needed to separate the path segments and parameters. This function returns a 5-item *note named tuple: aa3.: (addressing scheme, network location, path, query, fragment identifier). The return value is a *note named tuple: aa3, its items can be accessed by index or as named attributes: Attribute Index Value Value if not present -------------------------------------------------------------------------------------------- ‘scheme’ 0 URL scheme specifier `scheme' parameter ‘netloc’ 1 Network location part empty string ‘path’ 2 Hierarchical path empty string ‘query’ 3 Query component empty string ‘fragment’ 4 Fragment identifier empty string ‘username’ User name *note None: 157. ‘password’ Password *note None: 157. ‘hostname’ Host name (lower case) *note None: 157. ‘port’ Port number as integer, if *note None: 157. present Reading the ‘port’ attribute will raise a *note ValueError: 1fb. if an invalid port is specified in the URL. See section *note Structured Parse Results: 29c4. for more information on the result object. Unmatched square brackets in the ‘netloc’ attribute will raise a *note ValueError: 1fb. Characters in the ‘netloc’ attribute that decompose under NFKC normalization (as used by the IDNA encoding) into any of ‘/’, ‘?’, ‘#’, ‘@’, or ‘:’ will raise a *note ValueError: 1fb. If the URL is decomposed before parsing, no error will be raised. Changed in version 3.6: Out-of-range port numbers now raise *note ValueError: 1fb, instead of returning *note None: 157. Changed in version 3.8: Characters that affect netloc parsing under NFKC normalization will now raise *note ValueError: 1fb. -- Function: urllib.parse.urlunsplit (parts) Combine the elements of a tuple as returned by *note urlsplit(): 5f9. into a complete URL as a string. The `parts' argument can be any five-item iterable. This may result in a slightly different, but equivalent URL, if the URL that was parsed originally had unnecessary delimiters (for example, a ? with an empty query; the RFC states that these are equivalent). -- Function: urllib.parse.urljoin (base, url, allow_fragments=True) Construct a full (“absolute”) URL by combining a “base URL” (`base') with another URL (`url'). Informally, this uses components of the base URL, in particular the addressing scheme, the network location and (part of) the path, to provide missing components in the relative URL. For example: >>> from urllib.parse import urljoin >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html') 'http://www.cwi.nl/%7Eguido/FAQ.html' The `allow_fragments' argument has the same meaning and default as for *note urlparse(): 5fa. Note: If `url' is an absolute URL (that is, starting with ‘//’ or ‘scheme://’), the `url'’s host name and/or scheme will be present in the result. For example: >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html', ... '//www.python.org/%7Eguido') 'http://www.python.org/%7Eguido' If you do not want that behavior, preprocess the `url' with *note urlsplit(): 5f9. and *note urlunsplit(): 29c6, removing possible `scheme' and `netloc' parts. Changed in version 3.5: Behaviour updated to match the semantics defined in RFC 3986(4). -- Function: urllib.parse.urldefrag (url) If `url' contains a fragment identifier, return a modified version of `url' with no fragment identifier, and the fragment identifier as a separate string. If there is no fragment identifier in `url', return `url' unmodified and an empty string. The return value is a *note named tuple: aa3, its items can be accessed by index or as named attributes: Attribute Index Value Value if not present -------------------------------------------------------------------------------------------- ‘url’ 0 URL with no fragment empty string ‘fragment’ 1 Fragment identifier empty string See section *note Structured Parse Results: 29c4. for more information on the result object. Changed in version 3.2: Result is a structured object rather than a simple 2-tuple. -- Function: urllib.parse.unwrap (url) Extract the url from a wrapped URL (that is, a string formatted as ‘<URL:scheme://host/path>’, ‘<scheme://host/path>’, ‘URL:scheme://host/path’ or ‘scheme://host/path’). If `url' is not a wrapped URL, it is returned without changes. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc1808.html (2) https://tools.ietf.org/html/rfc3986.html (3) https://tools.ietf.org/html/rfc2396.html (4) https://tools.ietf.org/html/rfc3986.html  File: python.info, Node: Parsing ASCII Encoded Bytes, Next: Structured Parse Results, Prev: URL Parsing, Up: urllib parse — Parse URLs into components 5.21.8.2 Parsing ASCII Encoded Bytes .................................... The URL parsing functions were originally designed to operate on character strings only. In practice, it is useful to be able to manipulate properly quoted and encoded URLs as sequences of ASCII bytes. Accordingly, the URL parsing functions in this module all operate on *note bytes: 331. and *note bytearray: 332. objects in addition to *note str: 330. objects. If *note str: 330. data is passed in, the result will also contain only *note str: 330. data. If *note bytes: 331. or *note bytearray: 332. data is passed in, the result will contain only *note bytes: 331. data. Attempting to mix *note str: 330. data with *note bytes: 331. or *note bytearray: 332. in a single function call will result in a *note TypeError: 192. being raised, while attempting to pass in non-ASCII byte values will trigger *note UnicodeDecodeError: 1fd. To support easier conversion of result objects between *note str: 330. and *note bytes: 331, all return values from URL parsing functions provide either an ‘encode()’ method (when the result contains *note str: 330. data) or a ‘decode()’ method (when the result contains *note bytes: 331. data). The signatures of these methods match those of the corresponding *note str: 330. and *note bytes: 331. methods (except that the default encoding is ‘'ascii'’ rather than ‘'utf-8'’). Each produces a value of a corresponding type that contains either *note bytes: 331. data (for ‘encode()’ methods) or *note str: 330. data (for ‘decode()’ methods). Applications that need to operate on potentially improperly quoted URLs that may contain non-ASCII data will need to do their own decoding from bytes to characters before invoking the URL parsing methods. The behaviour described in this section applies only to the URL parsing functions. The URL quoting functions use their own rules when producing or consuming byte sequences as detailed in the documentation of the individual URL quoting functions. Changed in version 3.2: URL parsing functions now accept ASCII encoded byte sequences  File: python.info, Node: Structured Parse Results, Next: URL Quoting, Prev: Parsing ASCII Encoded Bytes, Up: urllib parse — Parse URLs into components 5.21.8.3 Structured Parse Results ................................. The result objects from the *note urlparse(): 5fa, *note urlsplit(): 5f9. and *note urldefrag(): bde. functions are subclasses of the *note tuple: 47e. type. These subclasses add the attributes listed in the documentation for those functions, the encoding and decoding support described in the previous section, as well as an additional method: -- Method: urllib.parse.SplitResult.geturl () Return the re-combined version of the original URL as a string. This may differ from the original URL in that the scheme may be normalized to lower case and empty components may be dropped. Specifically, empty parameters, queries, and fragment identifiers will be removed. For *note urldefrag(): bde. results, only empty fragment identifiers will be removed. For *note urlsplit(): 5f9. and *note urlparse(): 5fa. results, all noted changes will be made to the URL returned by this method. The result of this method remains unchanged if passed back through the original parsing function: >>> from urllib.parse import urlsplit >>> url = 'HTTP://www.Python.org/doc/#' >>> r1 = urlsplit(url) >>> r1.geturl() 'http://www.Python.org/doc/' >>> r2 = urlsplit(r1.geturl()) >>> r2.geturl() 'http://www.Python.org/doc/' The following classes provide the implementations of the structured parse results when operating on *note str: 330. objects: -- Class: urllib.parse.DefragResult (url, fragment) Concrete class for *note urldefrag(): bde. results containing *note str: 330. data. The ‘encode()’ method returns a *note DefragResultBytes: 29cc. instance. New in version 3.2. -- Class: urllib.parse.ParseResult (scheme, netloc, path, params, query, fragment) Concrete class for *note urlparse(): 5fa. results containing *note str: 330. data. The ‘encode()’ method returns a *note ParseResultBytes: 29ce. instance. -- Class: urllib.parse.SplitResult (scheme, netloc, path, query, fragment) Concrete class for *note urlsplit(): 5f9. results containing *note str: 330. data. The ‘encode()’ method returns a *note SplitResultBytes: 29d0. instance. The following classes provide the implementations of the parse results when operating on *note bytes: 331. or *note bytearray: 332. objects: -- Class: urllib.parse.DefragResultBytes (url, fragment) Concrete class for *note urldefrag(): bde. results containing *note bytes: 331. data. The ‘decode()’ method returns a *note DefragResult: 29cb. instance. New in version 3.2. -- Class: urllib.parse.ParseResultBytes (scheme, netloc, path, params, query, fragment) Concrete class for *note urlparse(): 5fa. results containing *note bytes: 331. data. The ‘decode()’ method returns a *note ParseResult: 29cd. instance. New in version 3.2. -- Class: urllib.parse.SplitResultBytes (scheme, netloc, path, query, fragment) Concrete class for *note urlsplit(): 5f9. results containing *note bytes: 331. data. The ‘decode()’ method returns a *note SplitResult: 29cf. instance. New in version 3.2.  File: python.info, Node: URL Quoting, Prev: Structured Parse Results, Up: urllib parse — Parse URLs into components 5.21.8.4 URL Quoting .................... The URL quoting functions focus on taking program data and making it safe for use as URL components by quoting special characters and appropriately encoding non-ASCII text. They also support reversing these operations to recreate the original data from the contents of a URL component if that task isn’t already covered by the URL parsing functions above. -- Function: urllib.parse.quote (string, safe='/', encoding=None, errors=None) Replace special characters in `string' using the ‘%xx’ escape. Letters, digits, and the characters ‘'_.-~'’ are never quoted. By default, this function is intended for quoting the path section of URL. The optional `safe' parameter specifies additional ASCII characters that should not be quoted — its default value is ‘'/'’. `string' may be either a *note str: 330. or a *note bytes: 331. Changed in version 3.7: Moved from RFC 2396(1) to RFC 3986(2) for quoting URL strings. “~” is now included in the set of unreserved characters. The optional `encoding' and `errors' parameters specify how to deal with non-ASCII characters, as accepted by the *note str.encode(): c37. method. `encoding' defaults to ‘'utf-8'’. `errors' defaults to ‘'strict'’, meaning unsupported characters raise a *note UnicodeEncodeError: 1fc. `encoding' and `errors' must not be supplied if `string' is a *note bytes: 331, or a *note TypeError: 192. is raised. Note that ‘quote(string, safe, encoding, errors)’ is equivalent to ‘quote_from_bytes(string.encode(encoding, errors), safe)’. Example: ‘quote('/El Niño/')’ yields ‘'/El%20Ni%C3%B1o/'’. -- Function: urllib.parse.quote_plus (string, safe='', encoding=None, errors=None) Like *note quote(): 40d, but also replace spaces by plus signs, as required for quoting HTML form values when building up a query string to go into a URL. Plus signs in the original string are escaped unless they are included in `safe'. It also does not have `safe' default to ‘'/'’. Example: ‘quote_plus('/El Niño/')’ yields ‘'%2FEl+Ni%C3%B1o%2F'’. -- Function: urllib.parse.quote_from_bytes (bytes, safe='/') Like *note quote(): 40d, but accepts a *note bytes: 331. object rather than a *note str: 330, and does not perform string-to-bytes encoding. Example: ‘quote_from_bytes(b'a&\xef')’ yields ‘'a%26%EF'’. -- Function: urllib.parse.unquote (string, encoding='utf-8', errors='replace') Replace ‘%xx’ escapes by their single-character equivalent. The optional `encoding' and `errors' parameters specify how to decode percent-encoded sequences into Unicode characters, as accepted by the *note bytes.decode(): c38. method. `string' must be a *note str: 330. `encoding' defaults to ‘'utf-8'’. `errors' defaults to ‘'replace'’, meaning invalid sequences are replaced by a placeholder character. Example: ‘unquote('/El%20Ni%C3%B1o/')’ yields ‘'/El Niño/'’. -- Function: urllib.parse.unquote_plus (string, encoding='utf-8', errors='replace') Like *note unquote(): 2946, but also replace plus signs by spaces, as required for unquoting HTML form values. `string' must be a *note str: 330. Example: ‘unquote_plus('/El+Ni%C3%B1o/')’ yields ‘'/El Niño/'’. -- Function: urllib.parse.unquote_to_bytes (string) Replace ‘%xx’ escapes by their single-octet equivalent, and return a *note bytes: 331. object. `string' may be either a *note str: 330. or a *note bytes: 331. If it is a *note str: 330, unescaped non-ASCII characters in `string' are encoded into UTF-8 bytes. Example: ‘unquote_to_bytes('a%26%EF')’ yields ‘b'a&\xef'’. -- Function: urllib.parse.urlencode (query, doseq=False, safe='', encoding=None, errors=None, quote_via=quote_plus) Convert a mapping object or a sequence of two-element tuples, which may contain *note str: 330. or *note bytes: 331. objects, to a percent-encoded ASCII text string. If the resultant string is to be used as a `data' for POST operation with the *note urlopen(): 78c. function, then it should be encoded to bytes, otherwise it would result in a *note TypeError: 192. The resulting string is a series of ‘key=value’ pairs separated by ‘'&'’ characters, where both `key' and `value' are quoted using the `quote_via' function. By default, *note quote_plus(): bdf. is used to quote the values, which means spaces are quoted as a ‘'+'’ character and ‘/’ characters are encoded as ‘%2F’, which follows the standard for GET requests (‘application/x-www-form-urlencoded’). An alternate function that can be passed as `quote_via' is *note quote(): 40d, which will encode spaces as ‘%20’ and not encode ‘/’ characters. For maximum control of what is quoted, use ‘quote’ and specify a value for `safe'. When a sequence of two-element tuples is used as the `query' argument, the first element of each tuple is a key and the second is a value. The value element in itself can be a sequence and in that case, if the optional parameter `doseq' is evaluates to ‘True’, individual ‘key=value’ pairs separated by ‘'&'’ are generated for each element of the value sequence for the key. The order of parameters in the encoded string will match the order of parameter tuples in the sequence. The `safe', `encoding', and `errors' parameters are passed down to `quote_via' (the `encoding' and `errors' parameters are only passed when a query element is a *note str: 330.). To reverse this encoding process, *note parse_qs(): 2eb. and *note parse_qsl(): 2ec. are provided in this module to parse query strings into Python data structures. Refer to *note urllib examples: 29b6. to find out how urlencode method can be used for generating query string for a URL or data for POST. Changed in version 3.2: Query parameter supports bytes and string objects. New in version 3.5: `quote_via' parameter. See also ........ RFC 3986(3) - Uniform Resource Identifiers This is the current standard (STD66). Any changes to urllib.parse module should conform to this. Certain deviations could be observed, which are mostly for backward compatibility purposes and for certain de-facto parsing requirements as commonly observed in major browsers. RFC 2732(4) - Format for Literal IPv6 Addresses in URL’s. This specifies the parsing requirements of IPv6 URLs. RFC 2396(5) - Uniform Resource Identifiers (URI): Generic Syntax Document describing the generic syntactic requirements for both Uniform Resource Names (URNs) and Uniform Resource Locators (URLs). RFC 2368(6) - The mailto URL scheme. Parsing requirements for mailto URL schemes. RFC 1808(7) - Relative Uniform Resource Locators This Request For Comments includes the rules for joining an absolute and a relative URL, including a fair number of “Abnormal Examples” which govern the treatment of border cases. RFC 1738(8) - Uniform Resource Locators (URL) This specifies the formal syntax and semantics of absolute URLs. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2396.html (2) https://tools.ietf.org/html/rfc3986.html (3) https://tools.ietf.org/html/rfc3986.html (4) https://tools.ietf.org/html/rfc2732.html (5) https://tools.ietf.org/html/rfc2396.html (6) https://tools.ietf.org/html/rfc2368.html (7) https://tools.ietf.org/html/rfc1808.html (8) https://tools.ietf.org/html/rfc1738.html  File: python.info, Node: urllib error — Exception classes raised by urllib request, Next: urllib robotparser — Parser for robots txt, Prev: urllib parse — Parse URLs into components, Up: Internet Protocols and Support 5.21.9 ‘urllib.error’ — Exception classes raised by urllib.request ------------------------------------------------------------------ `Source code:' Lib/urllib/error.py(1) __________________________________________________________________ The *note urllib.error: 11e. module defines the exception classes for exceptions raised by *note urllib.request: 120. The base exception class is *note URLError: 2937. The following exceptions are raised by *note urllib.error: 11e. as appropriate: -- Exception: urllib.error.URLError The handlers raise this exception (or derived exceptions) when they run into a problem. It is a subclass of *note OSError: 1d3. -- Attribute: reason The reason for this error. It can be a message string or another exception instance. Changed in version 3.3: *note URLError: 2937. has been made a subclass of *note OSError: 1d3. instead of *note IOError: 992. -- Exception: urllib.error.HTTPError Though being an exception (a subclass of *note URLError: 2937.), an *note HTTPError: 8fc. can also function as a non-exceptional file-like return value (the same thing that *note urlopen(): 78c. returns). This is useful when handling exotic HTTP errors, such as requests for authentication. -- Attribute: code An HTTP status code as defined in RFC 2616(2). This numeric value corresponds to a value found in the dictionary of codes as found in *note http.server.BaseHTTPRequestHandler.responses: 29d9. -- Attribute: reason This is usually a string explaining the reason for this error. -- Attribute: headers The HTTP response headers for the HTTP request that caused the *note HTTPError: 8fc. New in version 3.4. -- Exception: urllib.error.ContentTooShortError (msg, content) This exception is raised when the *note urlretrieve(): 29b8. function detects that the amount of the downloaded data is less than the expected amount (given by the `Content-Length' header). The ‘content’ attribute stores the downloaded (and supposedly truncated) data. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/urllib/error.py (2) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: urllib robotparser — Parser for robots txt, Next: http — HTTP modules, Prev: urllib error — Exception classes raised by urllib request, Up: Internet Protocols and Support 5.21.10 ‘urllib.robotparser’ — Parser for robots.txt ---------------------------------------------------- `Source code:' Lib/urllib/robotparser.py(1) __________________________________________________________________ This module provides a single class, *note RobotFileParser: 5ad, which answers questions about whether or not a particular user agent can fetch a URL on the Web site that published the ‘robots.txt’ file. For more details on the structure of ‘robots.txt’ files, see ‘http://www.robotstxt.org/orig.html’. -- Class: urllib.robotparser.RobotFileParser (url='') This class provides methods to read, parse and answer questions about the ‘robots.txt’ file at `url'. -- Method: set_url (url) Sets the URL referring to a ‘robots.txt’ file. -- Method: read () Reads the ‘robots.txt’ URL and feeds it to the parser. -- Method: parse (lines) Parses the lines argument. -- Method: can_fetch (useragent, url) Returns ‘True’ if the `useragent' is allowed to fetch the `url' according to the rules contained in the parsed ‘robots.txt’ file. -- Method: mtime () Returns the time the ‘robots.txt’ file was last fetched. This is useful for long-running web spiders that need to check for new ‘robots.txt’ files periodically. -- Method: modified () Sets the time the ‘robots.txt’ file was last fetched to the current time. -- Method: crawl_delay (useragent) Returns the value of the ‘Crawl-delay’ parameter from ‘robots.txt’ for the `useragent' in question. If there is no such parameter or it doesn’t apply to the `useragent' specified or the ‘robots.txt’ entry for this parameter has invalid syntax, return ‘None’. New in version 3.6. -- Method: request_rate (useragent) Returns the contents of the ‘Request-rate’ parameter from ‘robots.txt’ as a *note named tuple: aa3. ‘RequestRate(requests, seconds)’. If there is no such parameter or it doesn’t apply to the `useragent' specified or the ‘robots.txt’ entry for this parameter has invalid syntax, return ‘None’. New in version 3.6. -- Method: site_maps () Returns the contents of the ‘Sitemap’ parameter from ‘robots.txt’ in the form of a *note list(): 262. If there is no such parameter or the ‘robots.txt’ entry for this parameter has invalid syntax, return ‘None’. New in version 3.8. The following example demonstrates basic use of the *note RobotFileParser: 5ad. class: >>> import urllib.robotparser >>> rp = urllib.robotparser.RobotFileParser() >>> rp.set_url("http://www.musi-cal.com/robots.txt") >>> rp.read() >>> rrate = rp.request_rate("*") >>> rrate.requests 3 >>> rrate.seconds 20 >>> rp.crawl_delay("*") 6 >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco") False >>> rp.can_fetch("*", "http://www.musi-cal.com/") True ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/urllib/robotparser.py  File: python.info, Node: http — HTTP modules, Next: http client — HTTP protocol client, Prev: urllib robotparser — Parser for robots txt, Up: Internet Protocols and Support 5.21.11 ‘http’ — HTTP modules ----------------------------- `Source code:' Lib/http/__init__.py(1) __________________________________________________________________ *note http: 93. is a package that collects several modules for working with the HyperText Transfer Protocol: * *note http.client: 94. is a low-level HTTP protocol client; for high-level URL opening use *note urllib.request: 120. * *note http.server: 97. contains basic HTTP server classes based on *note socketserver: f0. * *note http.cookies: 96. has utilities for implementing state management with cookies * *note http.cookiejar: 95. provides persistence of cookies *note http: 93. is also a module that defines a number of HTTP status codes and associated messages through the *note http.HTTPStatus: 6e2. enum: -- Class: http.HTTPStatus New in version 3.5. A subclass of *note enum.IntEnum: 58d. that defines a set of HTTP status codes, reason phrases and long descriptions written in English. Usage: >>> from http import HTTPStatus >>> HTTPStatus.OK <HTTPStatus.OK: 200> >>> HTTPStatus.OK == 200 True >>> HTTPStatus.OK.value 200 >>> HTTPStatus.OK.phrase 'OK' >>> HTTPStatus.OK.description 'Request fulfilled, document follows' >>> list(HTTPStatus) [<HTTPStatus.CONTINUE: 100>, <HTTPStatus.SWITCHING_PROTOCOLS: 101>, ...] * Menu: * HTTP status codes:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/http/__init__.py  File: python.info, Node: HTTP status codes, Up: http — HTTP modules 5.21.11.1 HTTP status codes ........................... Supported, IANA-registered(1) status codes available in *note http.HTTPStatus: 6e2. are: Code Enum Name Details ---------------------------------------------------------------------------------------------------------------------------------------- ‘100’ ‘CONTINUE’ HTTP/1.1 RFC 7231(2), Section 6.2.1 ‘101’ ‘SWITCHING_PROTOCOLS’ HTTP/1.1 RFC 7231(3), Section 6.2.2 ‘102’ ‘PROCESSING’ WebDAV RFC 2518(4), Section 10.1 ‘200’ ‘OK’ HTTP/1.1 RFC 7231(5), Section 6.3.1 ‘201’ ‘CREATED’ HTTP/1.1 RFC 7231(6), Section 6.3.2 ‘202’ ‘ACCEPTED’ HTTP/1.1 RFC 7231(7), Section 6.3.3 ‘203’ ‘NON_AUTHORITATIVE_INFORMATION’ HTTP/1.1 RFC 7231(8), Section 6.3.4 ‘204’ ‘NO_CONTENT’ HTTP/1.1 RFC 7231(9), Section 6.3.5 ‘205’ ‘RESET_CONTENT’ HTTP/1.1 RFC 7231(10), Section 6.3.6 ‘206’ ‘PARTIAL_CONTENT’ HTTP/1.1 RFC 7233(11), Section 4.1 ‘207’ ‘MULTI_STATUS’ WebDAV RFC 4918(12), Section 11.1 ‘208’ ‘ALREADY_REPORTED’ WebDAV Binding Extensions RFC 5842(13), Section 7.1 (Experimental) ‘226’ ‘IM_USED’ Delta Encoding in HTTP RFC 3229(14), Section 10.4.1 ‘300’ ‘MULTIPLE_CHOICES’ HTTP/1.1 RFC 7231(15), Section 6.4.1 ‘301’ ‘MOVED_PERMANENTLY’ HTTP/1.1 RFC 7231(16), Section 6.4.2 ‘302’ ‘FOUND’ HTTP/1.1 RFC 7231(17), Section 6.4.3 ‘303’ ‘SEE_OTHER’ HTTP/1.1 RFC 7231(18), Section 6.4.4 ‘304’ ‘NOT_MODIFIED’ HTTP/1.1 RFC 7232(19), Section 4.1 ‘305’ ‘USE_PROXY’ HTTP/1.1 RFC 7231(20), Section 6.4.5 ‘307’ ‘TEMPORARY_REDIRECT’ HTTP/1.1 RFC 7231(21), Section 6.4.7 ‘308’ ‘PERMANENT_REDIRECT’ Permanent Redirect RFC 7238(22), Section 3 (Experimental) ‘400’ ‘BAD_REQUEST’ HTTP/1.1 RFC 7231(23), Section 6.5.1 ‘401’ ‘UNAUTHORIZED’ HTTP/1.1 Authentication RFC 7235(24), Section 3.1 ‘402’ ‘PAYMENT_REQUIRED’ HTTP/1.1 RFC 7231(25), Section 6.5.2 ‘403’ ‘FORBIDDEN’ HTTP/1.1 RFC 7231(26), Section 6.5.3 ‘404’ ‘NOT_FOUND’ HTTP/1.1 RFC 7231(27), Section 6.5.4 ‘405’ ‘METHOD_NOT_ALLOWED’ HTTP/1.1 RFC 7231(28), Section 6.5.5 ‘406’ ‘NOT_ACCEPTABLE’ HTTP/1.1 RFC 7231(29), Section 6.5.6 ‘407’ ‘PROXY_AUTHENTICATION_REQUIRED’ HTTP/1.1 Authentication RFC 7235(30), Section 3.2 ‘408’ ‘REQUEST_TIMEOUT’ HTTP/1.1 RFC 7231(31), Section 6.5.7 ‘409’ ‘CONFLICT’ HTTP/1.1 RFC 7231(32), Section 6.5.8 ‘410’ ‘GONE’ HTTP/1.1 RFC 7231(33), Section 6.5.9 ‘411’ ‘LENGTH_REQUIRED’ HTTP/1.1 RFC 7231(34), Section 6.5.10 ‘412’ ‘PRECONDITION_FAILED’ HTTP/1.1 RFC 7232(35), Section 4.2 ‘413’ ‘REQUEST_ENTITY_TOO_LARGE’ HTTP/1.1 RFC 7231(36), Section 6.5.11 ‘414’ ‘REQUEST_URI_TOO_LONG’ HTTP/1.1 RFC 7231(37), Section 6.5.12 ‘415’ ‘UNSUPPORTED_MEDIA_TYPE’ HTTP/1.1 RFC 7231(38), Section 6.5.13 ‘416’ ‘REQUESTED_RANGE_NOT_SATISFIABLE’ HTTP/1.1 Range Requests RFC 7233(39), Section 4.4 ‘417’ ‘EXPECTATION_FAILED’ HTTP/1.1 RFC 7231(40), Section 6.5.14 ‘421’ ‘MISDIRECTED_REQUEST’ HTTP/2 RFC 7540(41), Section 9.1.2 ‘422’ ‘UNPROCESSABLE_ENTITY’ WebDAV RFC 4918(42), Section 11.2 ‘423’ ‘LOCKED’ WebDAV RFC 4918(43), Section 11.3 ‘424’ ‘FAILED_DEPENDENCY’ WebDAV RFC 4918(44), Section 11.4 ‘426’ ‘UPGRADE_REQUIRED’ HTTP/1.1 RFC 7231(45), Section 6.5.15 ‘428’ ‘PRECONDITION_REQUIRED’ Additional HTTP Status Codes RFC 6585(46) ‘429’ ‘TOO_MANY_REQUESTS’ Additional HTTP Status Codes RFC 6585(47) ‘431’ ‘REQUEST_HEADER_FIELDS_TOO_LARGE’ Additional HTTP Status Codes RFC 6585(48) ‘451’ ‘UNAVAILABLE_FOR_LEGAL_REASONS’ An HTTP Status Code to Report Legal Obstacles RFC 7725(49) ‘500’ ‘INTERNAL_SERVER_ERROR’ HTTP/1.1 RFC 7231(50), Section 6.6.1 ‘501’ ‘NOT_IMPLEMENTED’ HTTP/1.1 RFC 7231(51), Section 6.6.2 ‘502’ ‘BAD_GATEWAY’ HTTP/1.1 RFC 7231(52), Section 6.6.3 ‘503’ ‘SERVICE_UNAVAILABLE’ HTTP/1.1 RFC 7231(53), Section 6.6.4 ‘504’ ‘GATEWAY_TIMEOUT’ HTTP/1.1 RFC 7231(54), Section 6.6.5 ‘505’ ‘HTTP_VERSION_NOT_SUPPORTED’ HTTP/1.1 RFC 7231(55), Section 6.6.6 ‘506’ ‘VARIANT_ALSO_NEGOTIATES’ Transparent Content Negotiation in HTTP RFC 2295(56), Section 8.1 (Experimental) ‘507’ ‘INSUFFICIENT_STORAGE’ WebDAV RFC 4918(57), Section 11.5 ‘508’ ‘LOOP_DETECTED’ WebDAV Binding Extensions RFC 5842(58), Section 7.2 (Experimental) ‘510’ ‘NOT_EXTENDED’ An HTTP Extension Framework RFC 2774(59), Section 7 (Experimental) ‘511’ ‘NETWORK_AUTHENTICATION_REQUIRED’ Additional HTTP Status Codes RFC 6585(60), Section 6 In order to preserve backwards compatibility, enum values are also present in the *note http.client: 94. module in the form of constants. The enum name is equal to the constant name (i.e. ‘http.HTTPStatus.OK’ is also available as ‘http.client.OK’). Changed in version 3.7: Added ‘421 MISDIRECTED_REQUEST’ status code. New in version 3.8: Added ‘451 UNAVAILABLE_FOR_LEGAL_REASONS’ status code. ---------- Footnotes ---------- (1) https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml (2) https://tools.ietf.org/html/rfc7231.html (3) https://tools.ietf.org/html/rfc7231.html (4) https://tools.ietf.org/html/rfc2518.html (5) https://tools.ietf.org/html/rfc7231.html (6) https://tools.ietf.org/html/rfc7231.html (7) https://tools.ietf.org/html/rfc7231.html (8) https://tools.ietf.org/html/rfc7231.html (9) https://tools.ietf.org/html/rfc7231.html (10) https://tools.ietf.org/html/rfc7231.html (11) https://tools.ietf.org/html/rfc7233.html (12) https://tools.ietf.org/html/rfc4918.html (13) https://tools.ietf.org/html/rfc5842.html (14) https://tools.ietf.org/html/rfc3229.html (15) https://tools.ietf.org/html/rfc7231.html (16) https://tools.ietf.org/html/rfc7231.html (17) https://tools.ietf.org/html/rfc7231.html (18) https://tools.ietf.org/html/rfc7231.html (19) https://tools.ietf.org/html/rfc7232.html (20) https://tools.ietf.org/html/rfc7231.html (21) https://tools.ietf.org/html/rfc7231.html (22) https://tools.ietf.org/html/rfc7238.html (23) https://tools.ietf.org/html/rfc7231.html (24) https://tools.ietf.org/html/rfc7235.html (25) https://tools.ietf.org/html/rfc7231.html (26) https://tools.ietf.org/html/rfc7231.html (27) https://tools.ietf.org/html/rfc7231.html (28) https://tools.ietf.org/html/rfc7231.html (29) https://tools.ietf.org/html/rfc7231.html (30) https://tools.ietf.org/html/rfc7235.html (31) https://tools.ietf.org/html/rfc7231.html (32) https://tools.ietf.org/html/rfc7231.html (33) https://tools.ietf.org/html/rfc7231.html (34) https://tools.ietf.org/html/rfc7231.html (35) https://tools.ietf.org/html/rfc7232.html (36) https://tools.ietf.org/html/rfc7231.html (37) https://tools.ietf.org/html/rfc7231.html (38) https://tools.ietf.org/html/rfc7231.html (39) https://tools.ietf.org/html/rfc7233.html (40) https://tools.ietf.org/html/rfc7231.html (41) https://tools.ietf.org/html/rfc7540.html (42) https://tools.ietf.org/html/rfc4918.html (43) https://tools.ietf.org/html/rfc4918.html (44) https://tools.ietf.org/html/rfc4918.html (45) https://tools.ietf.org/html/rfc7231.html (46) https://tools.ietf.org/html/rfc6585.html (47) https://tools.ietf.org/html/rfc6585.html (48) https://tools.ietf.org/html/rfc6585.html (49) https://tools.ietf.org/html/rfc7725.html (50) https://tools.ietf.org/html/rfc7231.html (51) https://tools.ietf.org/html/rfc7231.html (52) https://tools.ietf.org/html/rfc7231.html (53) https://tools.ietf.org/html/rfc7231.html (54) https://tools.ietf.org/html/rfc7231.html (55) https://tools.ietf.org/html/rfc7231.html (56) https://tools.ietf.org/html/rfc2295.html (57) https://tools.ietf.org/html/rfc4918.html (58) https://tools.ietf.org/html/rfc5842.html (59) https://tools.ietf.org/html/rfc2774.html (60) https://tools.ietf.org/html/rfc6585.html  File: python.info, Node: http client — HTTP protocol client, Next: ftplib — FTP protocol client, Prev: http — HTTP modules, Up: Internet Protocols and Support 5.21.12 ‘http.client’ — HTTP protocol client -------------------------------------------- `Source code:' Lib/http/client.py(1) __________________________________________________________________ This module defines classes which implement the client side of the HTTP and HTTPS protocols. It is normally not used directly — the module *note urllib.request: 120. uses it to handle URLs that use HTTP and HTTPS. See also ........ The Requests package(2) is recommended for a higher-level HTTP client interface. Note: HTTPS support is only available if Python was compiled with SSL support (through the *note ssl: f3. module). The module provides the following classes: -- Class: http.client.HTTPConnection (host, port=None[, timeout], source_address=None, blocksize=8192) An *note HTTPConnection: 392. instance represents one transaction with an HTTP server. It should be instantiated passing it a host and optional port number. If no port number is passed, the port is extracted from the host string if it has the form ‘host:port’, else the default HTTP port (80) is used. If the optional `timeout' parameter is given, blocking operations (like connection attempts) will timeout after that many seconds (if it is not given, the global default timeout setting is used). The optional `source_address' parameter may be a tuple of a (host, port) to use as the source address the HTTP connection is made from. The optional `blocksize' parameter sets the buffer size in bytes for sending a file-like message body. For example, the following calls all create instances that connect to the server at the same host and port: >>> h1 = http.client.HTTPConnection('www.python.org') >>> h2 = http.client.HTTPConnection('www.python.org:80') >>> h3 = http.client.HTTPConnection('www.python.org', 80) >>> h4 = http.client.HTTPConnection('www.python.org', 80, timeout=10) Changed in version 3.2: `source_address' was added. Changed in version 3.4: The `strict' parameter was removed. HTTP 0.9-style “Simple Responses” are not longer supported. Changed in version 3.7: `blocksize' parameter was added. -- Class: http.client.HTTPSConnection (host, port=None, key_file=None, cert_file=None[, timeout], source_address=None, *, context=None, check_hostname=None, blocksize=8192) A subclass of *note HTTPConnection: 392. that uses SSL for communication with secure servers. Default port is ‘443’. If `context' is specified, it must be a *note ssl.SSLContext: 3e4. instance describing the various SSL options. Please read *note Security considerations: 22a2. for more information on best practices. Changed in version 3.2: `source_address', `context' and `check_hostname' were added. Changed in version 3.2: This class now supports HTTPS virtual hosts if possible (that is, if *note ssl.HAS_SNI: 23d2. is true). Changed in version 3.4: The `strict' parameter was removed. HTTP 0.9-style “Simple Responses” are no longer supported. Changed in version 3.4.3: This class now performs all the necessary certificate and hostname checks by default. To revert to the previous, unverified, behavior ‘ssl._create_unverified_context()’ can be passed to the `context' parameter. Changed in version 3.8: This class now enables TLS 1.3 *note ssl.SSLContext.post_handshake_auth: 224. for the default `context' or when `cert_file' is passed with a custom `context'. Deprecated since version 3.6: `key_file' and `cert_file' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. The `check_hostname' parameter is also deprecated; the *note ssl.SSLContext.check_hostname: 23bd. attribute of `context' should be used instead. -- Class: http.client.HTTPResponse (sock, debuglevel=0, method=None, url=None) Class whose instances are returned upon successful connection. Not instantiated directly by user. Changed in version 3.4: The `strict' parameter was removed. HTTP 0.9 style “Simple Responses” are no longer supported. This module provides the following function: -- Function: http.client.parse_headers (fp) Parse the headers from a file pointer `fp' representing a HTTP request/response. The file has to be a ‘BufferedIOBase’ reader (i.e. not text) and must provide a valid RFC 2822(3) style header. This function returns an instance of ‘http.client.HTTPMessage’ that holds the header fields, but no payload (the same as *note HTTPResponse.msg: 29ee. and *note http.server.BaseHTTPRequestHandler.headers: 29ef.). After returning, the file pointer `fp' is ready to read the HTTP body. Note: *note parse_headers(): 29ed. does not parse the start-line of a HTTP message; it only parses the ‘Name: value’ lines. The file has to be ready to read these field lines, so the first line should already be consumed before calling the function. The following exceptions are raised as appropriate: -- Exception: http.client.HTTPException The base class of the other exceptions in this module. It is a subclass of *note Exception: 1a9. -- Exception: http.client.NotConnected A subclass of *note HTTPException: 29f0. -- Exception: http.client.InvalidURL A subclass of *note HTTPException: 29f0, raised if a port is given and is either non-numeric or empty. -- Exception: http.client.UnknownProtocol A subclass of *note HTTPException: 29f0. -- Exception: http.client.UnknownTransferEncoding A subclass of *note HTTPException: 29f0. -- Exception: http.client.UnimplementedFileMode A subclass of *note HTTPException: 29f0. -- Exception: http.client.IncompleteRead A subclass of *note HTTPException: 29f0. -- Exception: http.client.ImproperConnectionState A subclass of *note HTTPException: 29f0. -- Exception: http.client.CannotSendRequest A subclass of *note ImproperConnectionState: 29f7. -- Exception: http.client.CannotSendHeader A subclass of *note ImproperConnectionState: 29f7. -- Exception: http.client.ResponseNotReady A subclass of *note ImproperConnectionState: 29f7. -- Exception: http.client.BadStatusLine A subclass of *note HTTPException: 29f0. Raised if a server responds with a HTTP status code that we don’t understand. -- Exception: http.client.LineTooLong A subclass of *note HTTPException: 29f0. Raised if an excessively long line is received in the HTTP protocol from the server. -- Exception: http.client.RemoteDisconnected A subclass of *note ConnectionResetError: 9a0. and *note BadStatusLine: 29fb. Raised by *note HTTPConnection.getresponse(): 6e4. when the attempt to read the response results in no data read from the connection, indicating that the remote end has closed the connection. New in version 3.5: Previously, *note BadStatusLine: 29fb.‘('')’ was raised. The constants defined in this module are: -- Data: http.client.HTTP_PORT The default port for the HTTP protocol (always ‘80’). -- Data: http.client.HTTPS_PORT The default port for the HTTPS protocol (always ‘443’). -- Data: http.client.responses This dictionary maps the HTTP 1.1 status codes to the W3C names. Example: ‘http.client.responses[http.client.NOT_FOUND]’ is ‘'Not Found'’. See *note HTTP status codes: 29e9. for a list of HTTP status codes that are available in this module as constants. * Menu: * HTTPConnection Objects:: * HTTPResponse Objects:: * Examples: Examples<22>. * HTTPMessage Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/http/client.py (2) https://requests.readthedocs.io/en/master/ (3) https://tools.ietf.org/html/rfc2822.html  File: python.info, Node: HTTPConnection Objects, Next: HTTPResponse Objects, Up: http client — HTTP protocol client 5.21.12.1 HTTPConnection Objects ................................ *note HTTPConnection: 392. instances have the following methods: -- Method: HTTPConnection.request (method, url, body=None, headers={}, *, encode_chunked=False) This will send a request to the server using the HTTP request method `method' and the selector `url'. If `body' is specified, the specified data is sent after the headers are finished. It may be a *note str: 330, a *note bytes-like object: 5e8, an open *note file object: b42, or an iterable of *note bytes: 331. If `body' is a string, it is encoded as ISO-8859-1, the default for HTTP. If it is a bytes-like object, the bytes are sent as is. If it is a *note file object: b42, the contents of the file is sent; this file object should support at least the ‘read()’ method. If the file object is an instance of *note io.TextIOBase: c39, the data returned by the ‘read()’ method will be encoded as ISO-8859-1, otherwise the data returned by ‘read()’ is sent as is. If `body' is an iterable, the elements of the iterable are sent as is until the iterable is exhausted. The `headers' argument should be a mapping of extra HTTP headers to send with the request. If `headers' contains neither Content-Length nor Transfer-Encoding, but there is a request body, one of those header fields will be added automatically. If `body' is ‘None’, the Content-Length header is set to ‘0’ for methods that expect a body (‘PUT’, ‘POST’, and ‘PATCH’). If `body' is a string or a bytes-like object that is not also a *note file: b42, the Content-Length header is set to its length. Any other type of `body' (files and iterables in general) will be chunk-encoded, and the Transfer-Encoding header will automatically be set instead of Content-Length. The `encode_chunked' argument is only relevant if Transfer-Encoding is specified in `headers'. If `encode_chunked' is ‘False’, the HTTPConnection object assumes that all encoding is handled by the calling code. If it is ‘True’, the body will be chunk-encoded. Note: Chunked transfer encoding has been added to the HTTP protocol version 1.1. Unless the HTTP server is known to handle HTTP 1.1, the caller must either specify the Content-Length, or must pass a *note str: 330. or bytes-like object that is not also a file as the body representation. New in version 3.2: `body' can now be an iterable. Changed in version 3.6: If neither Content-Length nor Transfer-Encoding are set in `headers', file and iterable `body' objects are now chunk-encoded. The `encode_chunked' argument was added. No attempt is made to determine the Content-Length for file objects. -- Method: HTTPConnection.getresponse () Should be called after a request is sent to get the response from the server. Returns an *note HTTPResponse: a11. instance. Note: Note that you must have read the whole response before you can send a new request to the server. Changed in version 3.5: If a *note ConnectionError: 6e6. or subclass is raised, the *note HTTPConnection: 392. object will be ready to reconnect when a new request is sent. -- Method: HTTPConnection.set_debuglevel (level) Set the debugging level. The default debug level is ‘0’, meaning no debugging output is printed. Any value greater than ‘0’ will cause all currently defined debug output to be printed to stdout. The ‘debuglevel’ is passed to any new *note HTTPResponse: a11. objects that are created. New in version 3.1. -- Method: HTTPConnection.set_tunnel (host, port=None, headers=None) Set the host and the port for HTTP Connect Tunnelling. This allows running the connection through a proxy server. The host and port arguments specify the endpoint of the tunneled connection (i.e. the address included in the CONNECT request, `not' the address of the proxy server). The headers argument should be a mapping of extra HTTP headers to send with the CONNECT request. For example, to tunnel through a HTTPS proxy server running locally on port 8080, we would pass the address of the proxy to the *note HTTPSConnection: 393. constructor, and the address of the host that we eventually want to reach to the *note set_tunnel(): bad. method: >>> import http.client >>> conn = http.client.HTTPSConnection("localhost", 8080) >>> conn.set_tunnel("www.python.org") >>> conn.request("HEAD","/index.html") New in version 3.2. -- Method: HTTPConnection.connect () Connect to the server specified when the object was created. By default, this is called automatically when making a request if the client does not already have a connection. -- Method: HTTPConnection.close () Close the connection to the server. -- Attribute: HTTPConnection.blocksize Buffer size in bytes for sending a file-like message body. New in version 3.7. As an alternative to using the ‘request()’ method described above, you can also send your request step by step, by using the four functions below. -- Method: HTTPConnection.putrequest (method, url, skip_host=False, skip_accept_encoding=False) This should be the first call after the connection to the server has been made. It sends a line to the server consisting of the `method' string, the `url' string, and the HTTP version (‘HTTP/1.1’). To disable automatic sending of ‘Host:’ or ‘Accept-Encoding:’ headers (for example to accept additional content encodings), specify `skip_host' or `skip_accept_encoding' with non-False values. -- Method: HTTPConnection.putheader (header, argument[, ...]) Send an RFC 822(1)-style header to the server. It sends a line to the server consisting of the header, a colon and a space, and the first argument. If more arguments are given, continuation lines are sent, each consisting of a tab and an argument. -- Method: HTTPConnection.endheaders (message_body=None, *, encode_chunked=False) Send a blank line to the server, signalling the end of the headers. The optional `message_body' argument can be used to pass a message body associated with the request. If `encode_chunked' is ‘True’, the result of each iteration of `message_body' will be chunk-encoded as specified in RFC 7230(2), Section 3.3.1. How the data is encoded is dependent on the type of `message_body'. If `message_body' implements the *note buffer interface: 1291. the encoding will result in a single chunk. If `message_body' is a *note collections.abc.Iterable: 1601, each iteration of `message_body' will result in a chunk. If `message_body' is a *note file object: b42, each call to ‘.read()’ will result in a chunk. The method automatically signals the end of the chunk-encoded data immediately after `message_body'. Note: Due to the chunked encoding specification, empty chunks yielded by an iterator body will be ignored by the chunk-encoder. This is to avoid premature termination of the read of the request by the target server due to malformed encoding. New in version 3.6: Chunked encoding support. The `encode_chunked' parameter was added. -- Method: HTTPConnection.send (data) Send data to the server. This should be used directly only after the *note endheaders(): 550. method has been called and before *note getresponse(): 6e4. is called. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc822.html (2) https://tools.ietf.org/html/rfc7230.html  File: python.info, Node: HTTPResponse Objects, Next: Examples<22>, Prev: HTTPConnection Objects, Up: http client — HTTP protocol client 5.21.12.2 HTTPResponse Objects .............................. An *note HTTPResponse: a11. instance wraps the HTTP response from the server. It provides access to the request headers and the entity body. The response is an iterable object and can be used in a with statement. Changed in version 3.5: The *note io.BufferedIOBase: 588. interface is now implemented and all of its reader operations are supported. -- Method: HTTPResponse.read ([amt]) Reads and returns the response body, or up to the next `amt' bytes. -- Method: HTTPResponse.readinto (b) Reads up to the next len(b) bytes of the response body into the buffer `b'. Returns the number of bytes read. New in version 3.3. -- Method: HTTPResponse.getheader (name, default=None) Return the value of the header `name', or `default' if there is no header matching `name'. If there is more than one header with the name `name', return all of the values joined by ‘, ‘. If ‘default’ is any iterable other than a single string, its elements are similarly returned joined by commas. -- Method: HTTPResponse.getheaders () Return a list of (header, value) tuples. -- Method: HTTPResponse.fileno () Return the ‘fileno’ of the underlying socket. -- Attribute: HTTPResponse.msg A ‘http.client.HTTPMessage’ instance containing the response headers. ‘http.client.HTTPMessage’ is a subclass of *note email.message.Message: 541. -- Attribute: HTTPResponse.version HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1. -- Attribute: HTTPResponse.status Status code returned by server. -- Attribute: HTTPResponse.reason Reason phrase returned by server. -- Attribute: HTTPResponse.debuglevel A debugging hook. If *note debuglevel: 2a11. is greater than zero, messages will be printed to stdout as the response is read and parsed. -- Attribute: HTTPResponse.closed Is ‘True’ if the stream is closed.  File: python.info, Node: Examples<22>, Next: HTTPMessage Objects, Prev: HTTPResponse Objects, Up: http client — HTTP protocol client 5.21.12.3 Examples .................. Here is an example session that uses the ‘GET’ method: >>> import http.client >>> conn = http.client.HTTPSConnection("www.python.org") >>> conn.request("GET", "/") >>> r1 = conn.getresponse() >>> print(r1.status, r1.reason) 200 OK >>> data1 = r1.read() # This will return entire content. >>> # The following example demonstrates reading data in chunks. >>> conn.request("GET", "/") >>> r1 = conn.getresponse() >>> while chunk := r1.read(200): ... print(repr(chunk)) b'<!doctype html>\n<!--[if"... ... >>> # Example of an invalid request >>> conn = http.client.HTTPSConnection("docs.python.org") >>> conn.request("GET", "/parrot.spam") >>> r2 = conn.getresponse() >>> print(r2.status, r2.reason) 404 Not Found >>> data2 = r2.read() >>> conn.close() Here is an example session that uses the ‘HEAD’ method. Note that the ‘HEAD’ method never returns any data. >>> import http.client >>> conn = http.client.HTTPSConnection("www.python.org") >>> conn.request("HEAD", "/") >>> res = conn.getresponse() >>> print(res.status, res.reason) 200 OK >>> data = res.read() >>> print(len(data)) 0 >>> data == b'' True Here is an example session that shows how to ‘POST’ requests: >>> import http.client, urllib.parse >>> params = urllib.parse.urlencode({'@number': 12524, '@type': 'issue', '@action': 'show'}) >>> headers = {"Content-type": "application/x-www-form-urlencoded", ... "Accept": "text/plain"} >>> conn = http.client.HTTPConnection("bugs.python.org") >>> conn.request("POST", "", params, headers) >>> response = conn.getresponse() >>> print(response.status, response.reason) 302 Found >>> data = response.read() >>> data b'Redirecting to <a href="http://bugs.python.org/issue12524">http://bugs.python.org/issue12524</a>' >>> conn.close() Client side ‘HTTP PUT’ requests are very similar to ‘POST’ requests. The difference lies only the server side where HTTP server will allow resources to be created via ‘PUT’ request. It should be noted that custom HTTP methods are also handled in *note urllib.request.Request: 8f6. by setting the appropriate method attribute. Here is an example session that shows how to send a ‘PUT’ request using http.client: >>> # This creates an HTTP message >>> # with the content of BODY as the enclosed representation >>> # for the resource http://localhost:8080/file ... >>> import http.client >>> BODY = "***filecontents***" >>> conn = http.client.HTTPConnection("localhost", 8080) >>> conn.request("PUT", "/file", BODY) >>> response = conn.getresponse() >>> print(response.status, response.reason) 200, OK  File: python.info, Node: HTTPMessage Objects, Prev: Examples<22>, Up: http client — HTTP protocol client 5.21.12.4 HTTPMessage Objects ............................. An ‘http.client.HTTPMessage’ instance holds the headers from an HTTP response. It is implemented using the *note email.message.Message: 541. class.  File: python.info, Node: ftplib — FTP protocol client, Next: poplib — POP3 protocol client, Prev: http client — HTTP protocol client, Up: Internet Protocols and Support 5.21.13 ‘ftplib’ — FTP protocol client -------------------------------------- `Source code:' Lib/ftplib.py(1) __________________________________________________________________ This module defines the class *note FTP: 2f0. and a few related items. The *note FTP: 2f0. class implements the client side of the FTP protocol. You can use this to write Python programs that perform a variety of automated FTP jobs, such as mirroring other FTP servers. It is also used by the module *note urllib.request: 120. to handle URLs that use FTP. For more information on FTP (File Transfer Protocol), see Internet RFC 959(2). Here’s a sample session using the *note ftplib: 84. module: >>> from ftplib import FTP >>> ftp = FTP('ftp.debian.org') # connect to host, default port >>> ftp.login() # user anonymous, passwd anonymous@ '230 Login successful.' >>> ftp.cwd('debian') # change into "debian" directory >>> ftp.retrlines('LIST') # list directory contents -rw-rw-r-- 1 1176 1176 1063 Jun 15 10:18 README ... drwxr-sr-x 5 1176 1176 4096 Dec 19 2000 pool drwxr-sr-x 4 1176 1176 4096 Nov 17 2008 project drwxr-xr-x 3 1176 1176 4096 Oct 10 2012 tools '226 Directory send OK.' >>> with open('README', 'wb') as fp: >>> ftp.retrbinary('RETR README', fp.write) '226 Transfer complete.' >>> ftp.quit() The module defines the following items: -- Class: ftplib.FTP (host='', user='', passwd='', acct='', timeout=None, source_address=None) Return a new instance of the *note FTP: 2f0. class. When `host' is given, the method call ‘connect(host)’ is made. When `user' is given, additionally the method call ‘login(user, passwd, acct)’ is made (where `passwd' and `acct' default to the empty string when not given). The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if is not specified, the global default timeout setting will be used). `source_address' is a 2-tuple ‘(host, port)’ for the socket to bind to as its source address before connecting. The *note FTP: 2f0. class supports the *note with: 6e9. statement, e.g.: >>> from ftplib import FTP >>> with FTP("ftp1.at.proftpd.org") as ftp: ... ftp.login() ... ftp.dir() ... '230 Anonymous login ok, restrictions apply.' dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 . dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 .. dr-xr-xr-x 5 ftp ftp 4096 May 6 10:43 CentOS dr-xr-xr-x 3 ftp ftp 18 Jul 10 2008 Fedora >>> Changed in version 3.2: Support for the *note with: 6e9. statement was added. Changed in version 3.3: `source_address' parameter was added. -- Class: ftplib.FTP_TLS (host='', user='', passwd='', acct='', keyfile=None, certfile=None, context=None, timeout=None, source_address=None) A *note FTP: 2f0. subclass which adds TLS support to FTP as described in RFC 4217(3). Connect as usual to port 21 implicitly securing the FTP control connection before authenticating. Securing the data connection requires the user to explicitly ask for it by calling the *note prot_p(): 2a18. method. `context' is a *note ssl.SSLContext: 3e4. object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read *note Security considerations: 22a2. for best practices. `keyfile' and `certfile' are a legacy alternative to `context' – they can point to PEM-formatted private key and certificate chain files (respectively) for the SSL connection. New in version 3.2. Changed in version 3.3: `source_address' parameter was added. Changed in version 3.4: The class now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). Deprecated since version 3.6: `keyfile' and `certfile' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. Here’s a sample session using the *note FTP_TLS: a03. class: >>> ftps = FTP_TLS('ftp.pureftpd.org') >>> ftps.login() '230 Anonymous user logged in' >>> ftps.prot_p() '200 Data protection level set to "private"' >>> ftps.nlst() ['6jack', 'OpenBSD', 'antilink', 'blogbench', 'bsdcam', 'clockspeed', 'djbdns-jedi', 'docs', 'eaccelerator-jedi', 'favicon.ico', 'francotone', 'fugu', 'ignore', 'libpuzzle', 'metalog', 'minidentd', 'misc', 'mysql-udf-global-user-variables', 'php-jenkins-hash', 'php-skein-hash', 'php-webdav', 'phpaudit', 'phpbench', 'pincaster', 'ping', 'posto', 'pub', 'public', 'public_keys', 'pure-ftpd', 'qscan', 'qtc', 'sharedance', 'skycache', 'sound', 'tmp', 'ucarp'] -- Exception: ftplib.error_reply Exception raised when an unexpected reply is received from the server. -- Exception: ftplib.error_temp Exception raised when an error code signifying a temporary error (response codes in the range 400–499) is received. -- Exception: ftplib.error_perm Exception raised when an error code signifying a permanent error (response codes in the range 500–599) is received. -- Exception: ftplib.error_proto Exception raised when a reply is received from the server that does not fit the response specifications of the File Transfer Protocol, i.e. begin with a digit in the range 1–5. -- Data: ftplib.all_errors The set of all exceptions (as a tuple) that methods of *note FTP: 2f0. instances may raise as a result of problems with the FTP connection (as opposed to programming errors made by the caller). This set includes the four exceptions listed above as well as *note OSError: 1d3. and *note EOFError: c6c. See also ........ Module *note netrc: be. Parser for the ‘.netrc’ file format. The file ‘.netrc’ is typically used by FTP clients to load user authentication information before prompting the user. * Menu: * FTP Objects:: * FTP_TLS Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/ftplib.py (2) https://tools.ietf.org/html/rfc959.html (3) https://tools.ietf.org/html/rfc4217.html  File: python.info, Node: FTP Objects, Next: FTP_TLS Objects, Up: ftplib — FTP protocol client 5.21.13.1 FTP Objects ..................... Several methods are available in two flavors: one for handling text files and another for binary files. These are named for the command which is used followed by ‘lines’ for the text version or ‘binary’ for the binary version. *note FTP: 2f0. instances have the following methods: -- Method: FTP.set_debuglevel (level) Set the instance’s debugging level. This controls the amount of debugging output printed. The default, ‘0’, produces no debugging output. A value of ‘1’ produces a moderate amount of debugging output, generally a single line per request. A value of ‘2’ or higher produces the maximum amount of debugging output, logging each line sent and received on the control connection. -- Method: FTP.connect (host='', port=0, timeout=None, source_address=None) Connect to the given host and port. The default port number is ‘21’, as specified by the FTP protocol specification. It is rarely needed to specify a different port number. This function should be called only once for each instance; it should not be called at all if a host was given when the instance was created. All other methods can only be used after a connection has been made. The optional `timeout' parameter specifies a timeout in seconds for the connection attempt. If no `timeout' is passed, the global default timeout setting will be used. `source_address' is a 2-tuple ‘(host, port)’ for the socket to bind to as its source address before connecting. Raises an *note auditing event: fd1. ‘ftplib.connect’ with arguments ‘self’, ‘host’, ‘port’. Changed in version 3.3: `source_address' parameter was added. -- Method: FTP.getwelcome () Return the welcome message sent by the server in reply to the initial connection. (This message sometimes contains disclaimers or help information that may be relevant to the user.) -- Method: FTP.login (user='anonymous', passwd='', acct='') Log in as the given `user'. The `passwd' and `acct' parameters are optional and default to the empty string. If no `user' is specified, it defaults to ‘'anonymous'’. If `user' is ‘'anonymous'’, the default `passwd' is ‘'anonymous@'’. This function should be called only once for each instance, after a connection has been established; it should not be called at all if a host and user were given when the instance was created. Most FTP commands are only allowed after the client has logged in. The `acct' parameter supplies “accounting information”; few systems implement this. -- Method: FTP.abort () Abort a file transfer that is in progress. Using this does not always work, but it’s worth a try. -- Method: FTP.sendcmd (cmd) Send a simple command string to the server and return the response string. Raises an *note auditing event: fd1. ‘ftplib.sendcmd’ with arguments ‘self’, ‘cmd’. -- Method: FTP.voidcmd (cmd) Send a simple command string to the server and handle the response. Return nothing if a response code corresponding to success (codes in the range 200–299) is received. Raise *note error_reply: 2a19. otherwise. Raises an *note auditing event: fd1. ‘ftplib.sendcmd’ with arguments ‘self’, ‘cmd’. -- Method: FTP.retrbinary (cmd, callback, blocksize=8192, rest=None) Retrieve a file in binary transfer mode. `cmd' should be an appropriate ‘RETR’ command: ‘'RETR filename'’. The `callback' function is called for each block of data received, with a single bytes argument giving the data block. The optional `blocksize' argument specifies the maximum chunk size to read on the low-level socket object created to do the actual transfer (which will also be the largest size of the data blocks passed to `callback'). A reasonable default is chosen. `rest' means the same thing as in the *note transfercmd(): 2a28. method. -- Method: FTP.retrlines (cmd, callback=None) Retrieve a file or directory listing in ASCII transfer mode. `cmd' should be an appropriate ‘RETR’ command (see *note retrbinary(): 2a27.) or a command such as ‘LIST’ or ‘NLST’ (usually just the string ‘'LIST'’). ‘LIST’ retrieves a list of files and information about those files. ‘NLST’ retrieves a list of file names. The `callback' function is called for each line with a string argument containing the line with the trailing CRLF stripped. The default `callback' prints the line to ‘sys.stdout’. -- Method: FTP.set_pasv (val) Enable “passive” mode if `val' is true, otherwise disable passive mode. Passive mode is on by default. -- Method: FTP.storbinary (cmd, fp, blocksize=8192, callback=None, rest=None) Store a file in binary transfer mode. `cmd' should be an appropriate ‘STOR’ command: ‘"STOR filename"’. `fp' is a *note file object: b42. (opened in binary mode) which is read until EOF using its ‘read()’ method in blocks of size `blocksize' to provide the data to be stored. The `blocksize' argument defaults to 8192. `callback' is an optional single parameter callable that is called on each block of data after it is sent. `rest' means the same thing as in the *note transfercmd(): 2a28. method. Changed in version 3.2: `rest' parameter added. -- Method: FTP.storlines (cmd, fp, callback=None) Store a file in ASCII transfer mode. `cmd' should be an appropriate ‘STOR’ command (see *note storbinary(): c9f.). Lines are read until EOF from the *note file object: b42. `fp' (opened in binary mode) using its *note readline(): 13ae. method to provide the data to be stored. `callback' is an optional single parameter callable that is called on each line after it is sent. -- Method: FTP.transfercmd (cmd, rest=None) Initiate a transfer over the data connection. If the transfer is active, send an ‘EPRT’ or ‘PORT’ command and the transfer command specified by `cmd', and accept the connection. If the server is passive, send an ‘EPSV’ or ‘PASV’ command, connect to it, and start the transfer command. Either way, return the socket for the connection. If optional `rest' is given, a ‘REST’ command is sent to the server, passing `rest' as an argument. `rest' is usually a byte offset into the requested file, telling the server to restart sending the file’s bytes at the requested offset, skipping over the initial bytes. Note however that RFC 959(1) requires only that `rest' be a string containing characters in the printable range from ASCII code 33 to ASCII code 126. The *note transfercmd(): 2a28. method, therefore, converts `rest' to a string, but no check is performed on the string’s contents. If the server does not recognize the ‘REST’ command, an *note error_reply: 2a19. exception will be raised. If this happens, simply call *note transfercmd(): 2a28. without a `rest' argument. -- Method: FTP.ntransfercmd (cmd, rest=None) Like *note transfercmd(): 2a28, but returns a tuple of the data connection and the expected size of the data. If the expected size could not be computed, ‘None’ will be returned as the expected size. `cmd' and `rest' means the same thing as in *note transfercmd(): 2a28. -- Method: FTP.mlsd (path="", facts=[]) List a directory in a standardized format by using ‘MLSD’ command ( RFC 3659(2)). If `path' is omitted the current directory is assumed. `facts' is a list of strings representing the type of information desired (e.g. ‘["type", "size", "perm"]’). Return a generator object yielding a tuple of two elements for every file found in path. First element is the file name, the second one is a dictionary containing facts about the file name. Content of this dictionary might be limited by the `facts' argument but server is not guaranteed to return all requested facts. New in version 3.3. -- Method: FTP.nlst (argument[, ...]) Return a list of file names as returned by the ‘NLST’ command. The optional `argument' is a directory to list (default is the current server directory). Multiple arguments can be used to pass non-standard options to the ‘NLST’ command. Note: If your server supports the command, *note mlsd(): a05. offers a better API. -- Method: FTP.dir (argument[, ...]) Produce a directory listing as returned by the ‘LIST’ command, printing it to standard output. The optional `argument' is a directory to list (default is the current server directory). Multiple arguments can be used to pass non-standard options to the ‘LIST’ command. If the last argument is a function, it is used as a `callback' function as for *note retrlines(): 2a29.; the default prints to ‘sys.stdout’. This method returns ‘None’. Note: If your server supports the command, *note mlsd(): a05. offers a better API. -- Method: FTP.rename (fromname, toname) Rename file `fromname' on the server to `toname'. -- Method: FTP.delete (filename) Remove the file named `filename' from the server. If successful, returns the text of the response, otherwise raises *note error_perm: 2a1b. on permission errors or *note error_reply: 2a19. on other errors. -- Method: FTP.cwd (pathname) Set the current directory on the server. -- Method: FTP.mkd (pathname) Create a new directory on the server. -- Method: FTP.pwd () Return the pathname of the current directory on the server. -- Method: FTP.rmd (dirname) Remove the directory named `dirname' on the server. -- Method: FTP.size (filename) Request the size of the file named `filename' on the server. On success, the size of the file is returned as an integer, otherwise ‘None’ is returned. Note that the ‘SIZE’ command is not standardized, but is supported by many common server implementations. -- Method: FTP.quit () Send a ‘QUIT’ command to the server and close the connection. This is the “polite” way to close a connection, but it may raise an exception if the server responds with an error to the ‘QUIT’ command. This implies a call to the *note close(): 2a35. method which renders the *note FTP: 2f0. instance useless for subsequent calls (see below). -- Method: FTP.close () Close the connection unilaterally. This should not be applied to an already closed connection such as after a successful call to *note quit(): 2a34. After this call the *note FTP: 2f0. instance should not be used any more (after a call to *note close(): 2a35. or *note quit(): 2a34. you cannot reopen the connection by issuing another *note login(): 2a23. method). ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc959.html (2) https://tools.ietf.org/html/rfc3659.html  File: python.info, Node: FTP_TLS Objects, Prev: FTP Objects, Up: ftplib — FTP protocol client 5.21.13.2 FTP_TLS Objects ......................... *note FTP_TLS: a03. class inherits from *note FTP: 2f0, defining these additional objects: -- Attribute: FTP_TLS.ssl_version The SSL version to use (defaults to *note ssl.PROTOCOL_SSLv23: 23c2.). -- Method: FTP_TLS.auth () Set up a secure control connection by using TLS or SSL, depending on what is specified in the *note ssl_version: 2a37. attribute. Changed in version 3.4: The method now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). -- Method: FTP_TLS.ccc () Revert control channel back to plaintext. This can be useful to take advantage of firewalls that know how to handle NAT with non-secure FTP without opening fixed ports. New in version 3.3. -- Method: FTP_TLS.prot_p () Set up secure data connection. -- Method: FTP_TLS.prot_c () Set up clear text data connection.  File: python.info, Node: poplib — POP3 protocol client, Next: imaplib — IMAP4 protocol client, Prev: ftplib — FTP protocol client, Up: Internet Protocols and Support 5.21.14 ‘poplib’ — POP3 protocol client --------------------------------------- `Source code:' Lib/poplib.py(1) __________________________________________________________________ This module defines a class, *note POP3: 2a3c, which encapsulates a connection to a POP3 server and implements the protocol as defined in RFC 1939(2). The *note POP3: 2a3c. class supports both the minimal and optional command sets from RFC 1939(3). The *note POP3: 2a3c. class also supports the ‘STLS’ command introduced in RFC 2595(4) to enable encrypted communication on an already established connection. Additionally, this module provides a class *note POP3_SSL: bc1, which provides support for connecting to POP3 servers that use SSL as an underlying protocol layer. Note that POP3, though widely supported, is obsolescent. The implementation quality of POP3 servers varies widely, and too many are quite poor. If your mailserver supports IMAP, you would be better off using the *note imaplib.IMAP4: 60b. class, as IMAP servers tend to be better implemented. The *note poplib: d0. module provides two classes: -- Class: poplib.POP3 (host, port=POP3_PORT[, timeout]) This class implements the actual POP3 protocol. The connection is created when the instance is initialized. If `port' is omitted, the standard POP3 port (110) is used. The optional `timeout' parameter specifies a timeout in seconds for the connection attempt (if not specified, the global default timeout setting will be used). Raises an *note auditing event: fd1. ‘poplib.connect’ with arguments ‘self’, ‘host’, ‘port’. All commands will raise an *note auditing event: fd1. ‘poplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is the bytes about to be sent to the remote host. -- Class: poplib.POP3_SSL (host, port=POP3_SSL_PORT, keyfile=None, certfile=None, timeout=None, context=None) This is a subclass of *note POP3: 2a3c. that connects to the server over an SSL encrypted socket. If `port' is not specified, 995, the standard POP3-over-SSL port is used. `timeout' works as in the *note POP3: 2a3c. constructor. `context' is an optional *note ssl.SSLContext: 3e4. object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read *note Security considerations: 22a2. for best practices. `keyfile' and `certfile' are a legacy alternative to `context' - they can point to PEM-formatted private key and certificate chain files, respectively, for the SSL connection. Raises an *note auditing event: fd1. ‘poplib.connect’ with arguments ‘self’, ‘host’, ‘port’. All commands will raise an *note auditing event: fd1. ‘poplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is the bytes about to be sent to the remote host. Changed in version 3.2: `context' parameter added. Changed in version 3.4: The class now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). Deprecated since version 3.6: `keyfile' and `certfile' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. One exception is defined as an attribute of the *note poplib: d0. module: -- Exception: poplib.error_proto Exception raised on any errors from this module (errors from *note socket: ef. module are not caught). The reason for the exception is passed to the constructor as a string. See also ........ Module *note imaplib: 98. The standard Python IMAP module. Frequently Asked Questions About Fetchmail(5) The FAQ for the ‘fetchmail’ POP/IMAP client collects information on POP3 server variations and RFC noncompliance that may be useful if you need to write an application based on the POP protocol. * Menu: * POP3 Objects:: * POP3 Example:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/poplib.py (2) https://tools.ietf.org/html/rfc1939.html (3) https://tools.ietf.org/html/rfc1939.html (4) https://tools.ietf.org/html/rfc2595.html (5) http://www.catb.org/~esr/fetchmail/fetchmail-FAQ.html  File: python.info, Node: POP3 Objects, Next: POP3 Example, Up: poplib — POP3 protocol client 5.21.14.1 POP3 Objects ...................... All POP3 commands are represented by methods of the same name, in lower-case; most return the response text sent by the server. An *note POP3: 2a3c. instance has the following methods: -- Method: POP3.set_debuglevel (level) Set the instance’s debugging level. This controls the amount of debugging output printed. The default, ‘0’, produces no debugging output. A value of ‘1’ produces a moderate amount of debugging output, generally a single line per request. A value of ‘2’ or higher produces the maximum amount of debugging output, logging each line sent and received on the control connection. -- Method: POP3.getwelcome () Returns the greeting string sent by the POP3 server. -- Method: POP3.capa () Query the server’s capabilities as specified in RFC 2449(1). Returns a dictionary in the form ‘{'name': ['param'...]}’. New in version 3.4. -- Method: POP3.user (username) Send user command, response should indicate that a password is required. -- Method: POP3.pass_ (password) Send password, response includes message count and mailbox size. Note: the mailbox on the server is locked until ‘quit()’ is called. -- Method: POP3.apop (user, secret) Use the more secure APOP authentication to log into the POP3 server. -- Method: POP3.rpop (user) Use RPOP authentication (similar to UNIX r-commands) to log into POP3 server. -- Method: POP3.stat () Get mailbox status. The result is a tuple of 2 integers: ‘(message count, mailbox size)’. -- Method: POP3.list ([which]) Request message list, result is in the form ‘(response, ['mesg_num octets', ...], octets)’. If `which' is set, it is the message to list. -- Method: POP3.retr (which) Retrieve whole message number `which', and set its seen flag. Result is in form ‘(response, ['line', ...], octets)’. -- Method: POP3.dele (which) Flag message number `which' for deletion. On most servers deletions are not actually performed until QUIT (the major exception is Eudora QPOP, which deliberately violates the RFCs by doing pending deletes on any disconnect). -- Method: POP3.rset () Remove any deletion marks for the mailbox. -- Method: POP3.noop () Do nothing. Might be used as a keep-alive. -- Method: POP3.quit () Signoff: commit changes, unlock mailbox, drop connection. -- Method: POP3.top (which, howmuch) Retrieves the message header plus `howmuch' lines of the message after the header of message number `which'. Result is in form ‘(response, ['line', ...], octets)’. The POP3 TOP command this method uses, unlike the RETR command, doesn’t set the message’s seen flag; unfortunately, TOP is poorly specified in the RFCs and is frequently broken in off-brand servers. Test this method by hand against the POP3 servers you will use before trusting it. -- Method: POP3.uidl (which=None) Return message digest (unique id) list. If `which' is specified, result contains the unique id for that message in the form ‘'response mesgnum uid’, otherwise result is list ‘(response, ['mesgnum uid', ...], octets)’. -- Method: POP3.utf8 () Try to switch to UTF-8 mode. Returns the server response if successful, raises *note error_proto: b17. if not. Specified in RFC 6856(2). New in version 3.5. -- Method: POP3.stls (context=None) Start a TLS session on the active connection as specified in RFC 2595(3). This is only allowed before user authentication `context' parameter is a *note ssl.SSLContext: 3e4. object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read *note Security considerations: 22a2. for best practices. This method supports hostname checking via *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). New in version 3.4. Instances of *note POP3_SSL: bc1. have no additional methods. The interface of this subclass is identical to its parent. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2449.html (2) https://tools.ietf.org/html/rfc6856.html (3) https://tools.ietf.org/html/rfc2595.html  File: python.info, Node: POP3 Example, Prev: POP3 Objects, Up: poplib — POP3 protocol client 5.21.14.2 POP3 Example ...................... Here is a minimal example (without error checking) that opens a mailbox and retrieves and prints all messages: import getpass, poplib M = poplib.POP3('localhost') M.user(getpass.getuser()) M.pass_(getpass.getpass()) numMessages = len(M.list()[1]) for i in range(numMessages): for j in M.retr(i+1)[1]: print(j) At the end of the module, there is a test section that contains a more extensive example of usage.  File: python.info, Node: imaplib — IMAP4 protocol client, Next: nntplib — NNTP protocol client, Prev: poplib — POP3 protocol client, Up: Internet Protocols and Support 5.21.15 ‘imaplib’ — IMAP4 protocol client ----------------------------------------- `Source code:' Lib/imaplib.py(1) __________________________________________________________________ This module defines three classes, *note IMAP4: 60b, *note IMAP4_SSL: a17. and *note IMAP4_stream: 2a51, which encapsulate a connection to an IMAP4 server and implement a large subset of the IMAP4rev1 client protocol as defined in RFC 2060(2). It is backward compatible with IMAP4 ( RFC 1730(3)) servers, but note that the ‘STATUS’ command is not supported in IMAP4. Three classes are provided by the *note imaplib: 98. module, *note IMAP4: 60b. is the base class: -- Class: imaplib.IMAP4 (host='', port=IMAP4_PORT) This class implements the actual IMAP4 protocol. The connection is created and protocol version (IMAP4 or IMAP4rev1) is determined when the instance is initialized. If `host' is not specified, ‘''’ (the local host) is used. If `port' is omitted, the standard IMAP4 port (143) is used. The *note IMAP4: 60b. class supports the *note with: 6e9. statement. When used like this, the IMAP4 ‘LOGOUT’ command is issued automatically when the ‘with’ statement exits. E.g.: >>> from imaplib import IMAP4 >>> with IMAP4("domain.org") as M: ... M.noop() ... ('OK', [b'Nothing Accomplished. d25if65hy903weo.87']) Changed in version 3.5: Support for the *note with: 6e9. statement was added. Three exceptions are defined as attributes of the *note IMAP4: 60b. class: -- Exception: IMAP4.error Exception raised on any errors. The reason for the exception is passed to the constructor as a string. -- Exception: IMAP4.abort IMAP4 server errors cause this exception to be raised. This is a sub-class of *note IMAP4.error: 2a52. Note that closing the instance and instantiating a new one will usually allow recovery from this exception. -- Exception: IMAP4.readonly This exception is raised when a writable mailbox has its status changed by the server. This is a sub-class of *note IMAP4.error: 2a52. Some other client now has write permission, and the mailbox will need to be re-opened to re-obtain write permission. There’s also a subclass for secure connections: -- Class: imaplib.IMAP4_SSL (host='', port=IMAP4_SSL_PORT, keyfile=None, certfile=None, ssl_context=None) This is a subclass derived from *note IMAP4: 60b. that connects over an SSL encrypted socket (to use this class you need a socket module that was compiled with SSL support). If `host' is not specified, ‘''’ (the local host) is used. If `port' is omitted, the standard IMAP4-over-SSL port (993) is used. `ssl_context' is a *note ssl.SSLContext: 3e4. object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read *note Security considerations: 22a2. for best practices. `keyfile' and `certfile' are a legacy alternative to `ssl_context' - they can point to PEM-formatted private key and certificate chain files for the SSL connection. Note that the `keyfile'/`certfile' parameters are mutually exclusive with `ssl_context', a *note ValueError: 1fb. is raised if `keyfile'/`certfile' is provided along with `ssl_context'. Changed in version 3.3: `ssl_context' parameter added. Changed in version 3.4: The class now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). Deprecated since version 3.6: `keyfile' and `certfile' are deprecated in favor of `ssl_context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. The second subclass allows for connections created by a child process: -- Class: imaplib.IMAP4_stream (command) This is a subclass derived from *note IMAP4: 60b. that connects to the ‘stdin/stdout’ file descriptors created by passing `command' to ‘subprocess.Popen()’. The following utility functions are defined: -- Function: imaplib.Internaldate2tuple (datestr) Parse an IMAP4 ‘INTERNALDATE’ string and return corresponding local time. The return value is a *note time.struct_time: 599. tuple or ‘None’ if the string has wrong format. -- Function: imaplib.Int2AP (num) Converts an integer into a bytes representation using characters from the set [‘A’ .. ‘P’]. -- Function: imaplib.ParseFlags (flagstr) Converts an IMAP4 ‘FLAGS’ response to a tuple of individual flags. -- Function: imaplib.Time2Internaldate (date_time) Convert `date_time' to an IMAP4 ‘INTERNALDATE’ representation. The return value is a string in the form: ‘"DD-Mmm-YYYY HH:MM:SS +HHMM"’ (including double-quotes). The `date_time' argument can be a number (int or float) representing seconds since epoch (as returned by *note time.time(): 31d.), a 9-tuple representing local time an instance of *note time.struct_time: 599. (as returned by *note time.localtime(): 155c.), an aware instance of *note datetime.datetime: 194, or a double-quoted string. In the last case, it is assumed to already be in the correct format. Note that IMAP4 message numbers change as the mailbox changes; in particular, after an ‘EXPUNGE’ command performs deletions the remaining messages are renumbered. So it is highly advisable to use UIDs instead, with the UID command. At the end of the module, there is a test section that contains a more extensive example of usage. See also ........ Documents describing the protocol, sources for servers implementing it, by the University of Washington’s IMAP Information Center can all be found at (`Source Code') ‘https://github.com/uw-imap/imap’ (`Not Maintained'). * Menu: * IMAP4 Objects:: * IMAP4 Example:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/imaplib.py (2) https://tools.ietf.org/html/rfc2060.html (3) https://tools.ietf.org/html/rfc1730.html  File: python.info, Node: IMAP4 Objects, Next: IMAP4 Example, Up: imaplib — IMAP4 protocol client 5.21.15.1 IMAP4 Objects ....................... All IMAP4rev1 commands are represented by methods of the same name, either upper-case or lower-case. All arguments to commands are converted to strings, except for ‘AUTHENTICATE’, and the last argument to ‘APPEND’ which is passed as an IMAP4 literal. If necessary (the string contains IMAP4 protocol-sensitive characters and isn’t enclosed with either parentheses or double quotes) each string is quoted. However, the `password' argument to the ‘LOGIN’ command is always quoted. If you want to avoid having an argument string quoted (eg: the `flags' argument to ‘STORE’) then enclose the string in parentheses (eg: ‘r'(\Deleted)'’). Each command returns a tuple: ‘(type, [data, ...])’ where `type' is usually ‘'OK'’ or ‘'NO'’, and `data' is either the text from the command response, or mandated results from the command. Each `data' is either a ‘bytes’, or a tuple. If a tuple, then the first part is the header of the response, and the second part contains the data (ie: ‘literal’ value). The `message_set' options to commands below is a string specifying one or more messages to be acted upon. It may be a simple message number (‘'1'’), a range of message numbers (‘'2:4'’), or a group of non-contiguous ranges separated by commas (‘'1:3,6:9'’). A range can contain an asterisk to indicate an infinite upper bound (‘'3:*'’). An *note IMAP4: 60b. instance has the following methods: -- Method: IMAP4.append (mailbox, flags, date_time, message) Append `message' to named mailbox. -- Method: IMAP4.authenticate (mechanism, authobject) Authenticate command — requires response processing. `mechanism' specifies which authentication mechanism is to be used - it should appear in the instance variable ‘capabilities’ in the form ‘AUTH=mechanism’. `authobject' must be a callable object: data = authobject(response) It will be called to process server continuation responses; the `response' argument it is passed will be ‘bytes’. It should return ‘bytes’ `data' that will be base64 encoded and sent to the server. It should return ‘None’ if the client abort response ‘*’ should be sent instead. Changed in version 3.5: string usernames and passwords are now encoded to ‘utf-8’ instead of being limited to ASCII. -- Method: IMAP4.check () Checkpoint mailbox on server. -- Method: IMAP4.close () Close currently selected mailbox. Deleted messages are removed from writable mailbox. This is the recommended command before ‘LOGOUT’. -- Method: IMAP4.copy (message_set, new_mailbox) Copy `message_set' messages onto end of `new_mailbox'. -- Method: IMAP4.create (mailbox) Create new mailbox named `mailbox'. -- Method: IMAP4.delete (mailbox) Delete old mailbox named `mailbox'. -- Method: IMAP4.deleteacl (mailbox, who) Delete the ACLs (remove any rights) set for who on mailbox. -- Method: IMAP4.enable (capability) Enable `capability' (see RFC 5161(1)). Most capabilities do not need to be enabled. Currently only the ‘UTF8=ACCEPT’ capability is supported (see RFC 6855(2)). New in version 3.5: The *note enable(): 6ea. method itself, and RFC 6855(3) support. -- Method: IMAP4.expunge () Permanently remove deleted items from selected mailbox. Generates an ‘EXPUNGE’ response for each deleted message. Returned data contains a list of ‘EXPUNGE’ message numbers in order received. -- Method: IMAP4.fetch (message_set, message_parts) Fetch (parts of) messages. `message_parts' should be a string of message part names enclosed within parentheses, eg: ‘"(UID BODY[TEXT])"’. Returned data are tuples of message part envelope and data. -- Method: IMAP4.getacl (mailbox) Get the ‘ACL’s for `mailbox'. The method is non-standard, but is supported by the ‘Cyrus’ server. -- Method: IMAP4.getannotation (mailbox, entry, attribute) Retrieve the specified ‘ANNOTATION’s for `mailbox'. The method is non-standard, but is supported by the ‘Cyrus’ server. -- Method: IMAP4.getquota (root) Get the ‘quota’ `root'’s resource usage and limits. This method is part of the IMAP4 QUOTA extension defined in rfc2087. -- Method: IMAP4.getquotaroot (mailbox) Get the list of ‘quota’ ‘roots’ for the named `mailbox'. This method is part of the IMAP4 QUOTA extension defined in rfc2087. -- Method: IMAP4.list ([directory[, pattern]]) List mailbox names in `directory' matching `pattern'. `directory' defaults to the top-level mail folder, and `pattern' defaults to match anything. Returned data contains a list of ‘LIST’ responses. -- Method: IMAP4.login (user, password) Identify the client using a plaintext password. The `password' will be quoted. -- Method: IMAP4.login_cram_md5 (user, password) Force use of ‘CRAM-MD5’ authentication when identifying the client to protect the password. Will only work if the server ‘CAPABILITY’ response includes the phrase ‘AUTH=CRAM-MD5’. -- Method: IMAP4.logout () Shutdown connection to server. Returns server ‘BYE’ response. Changed in version 3.8: The method no longer ignores silently arbitrary exceptions. -- Method: IMAP4.lsub (directory='""', pattern='*') List subscribed mailbox names in directory matching pattern. `directory' defaults to the top level directory and `pattern' defaults to match any mailbox. Returned data are tuples of message part envelope and data. -- Method: IMAP4.myrights (mailbox) Show my ACLs for a mailbox (i.e. the rights that I have on mailbox). -- Method: IMAP4.namespace () Returns IMAP namespaces as defined in RFC 2342(4). -- Method: IMAP4.noop () Send ‘NOOP’ to server. -- Method: IMAP4.open (host, port) Opens socket to `port' at `host'. This method is implicitly called by the *note IMAP4: 60b. constructor. The connection objects established by this method will be used in the *note IMAP4.read(): 2a72, *note IMAP4.readline(): 2a73, *note IMAP4.send(): 2a74, and *note IMAP4.shutdown(): 2a75. methods. You may override this method. Raises an *note auditing event: fd1. ‘imaplib.open’ with arguments ‘self’, ‘host’, ‘port’. -- Method: IMAP4.partial (message_num, message_part, start, length) Fetch truncated part of a message. Returned data is a tuple of message part envelope and data. -- Method: IMAP4.proxyauth (user) Assume authentication as `user'. Allows an authorised administrator to proxy into any user’s mailbox. -- Method: IMAP4.read (size) Reads `size' bytes from the remote server. You may override this method. -- Method: IMAP4.readline () Reads one line from the remote server. You may override this method. -- Method: IMAP4.recent () Prompt server for an update. Returned data is ‘None’ if no new messages, else value of ‘RECENT’ response. -- Method: IMAP4.rename (oldmailbox, newmailbox) Rename mailbox named `oldmailbox' to `newmailbox'. -- Method: IMAP4.response (code) Return data for response `code' if received, or ‘None’. Returns the given code, instead of the usual type. -- Method: IMAP4.search (charset, criterion[, ...]) Search mailbox for matching messages. `charset' may be ‘None’, in which case no ‘CHARSET’ will be specified in the request to the server. The IMAP protocol requires that at least one criterion be specified; an exception will be raised when the server returns an error. `charset' must be ‘None’ if the ‘UTF8=ACCEPT’ capability was enabled using the *note enable(): 6ea. command. Example: # M is a connected IMAP4 instance... typ, msgnums = M.search(None, 'FROM', '"LDJ"') # or: typ, msgnums = M.search(None, '(FROM "LDJ")') -- Method: IMAP4.select (mailbox='INBOX', readonly=False) Select a mailbox. Returned data is the count of messages in `mailbox' (‘EXISTS’ response). The default `mailbox' is ‘'INBOX'’. If the `readonly' flag is set, modifications to the mailbox are not allowed. -- Method: IMAP4.send (data) Sends ‘data’ to the remote server. You may override this method. Raises an *note auditing event: fd1. ‘imaplib.send’ with arguments ‘self’, ‘data’. -- Method: IMAP4.setacl (mailbox, who, what) Set an ‘ACL’ for `mailbox'. The method is non-standard, but is supported by the ‘Cyrus’ server. -- Method: IMAP4.setannotation (mailbox, entry, attribute[, ...]) Set ‘ANNOTATION’s for `mailbox'. The method is non-standard, but is supported by the ‘Cyrus’ server. -- Method: IMAP4.setquota (root, limits) Set the ‘quota’ `root'’s resource `limits'. This method is part of the IMAP4 QUOTA extension defined in rfc2087. -- Method: IMAP4.shutdown () Close connection established in ‘open’. This method is implicitly called by *note IMAP4.logout(): 2a6c. You may override this method. -- Method: IMAP4.socket () Returns socket instance used to connect to server. -- Method: IMAP4.sort (sort_criteria, charset, search_criterion[, ...]) The ‘sort’ command is a variant of ‘search’ with sorting semantics for the results. Returned data contains a space separated list of matching message numbers. Sort has two arguments before the `search_criterion' argument(s); a parenthesized list of `sort_criteria', and the searching `charset'. Note that unlike ‘search’, the searching `charset' argument is mandatory. There is also a ‘uid sort’ command which corresponds to ‘sort’ the way that ‘uid search’ corresponds to ‘search’. The ‘sort’ command first searches the mailbox for messages that match the given searching criteria using the charset argument for the interpretation of strings in the searching criteria. It then returns the numbers of matching messages. This is an ‘IMAP4rev1’ extension command. -- Method: IMAP4.starttls (ssl_context=None) Send a ‘STARTTLS’ command. The `ssl_context' argument is optional and should be a *note ssl.SSLContext: 3e4. object. This will enable encryption on the IMAP connection. Please read *note Security considerations: 22a2. for best practices. New in version 3.2. Changed in version 3.4: The method now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). -- Method: IMAP4.status (mailbox, names) Request named status conditions for `mailbox'. -- Method: IMAP4.store (message_set, command, flag_list) Alters flag dispositions for messages in mailbox. `command' is specified by section 6.4.6 of RFC 2060(5) as being one of “FLAGS”, “+FLAGS”, or “-FLAGS”, optionally with a suffix of “.SILENT”. For example, to set the delete flag on all messages: typ, data = M.search(None, 'ALL') for num in data[0].split(): M.store(num, '+FLAGS', '\\Deleted') M.expunge() Note: Creating flags containing ‘]’ (for example: “[test]”) violates RFC 3501(6) (the IMAP protocol). However, imaplib has historically allowed creation of such tags, and popular IMAP servers, such as Gmail, accept and produce such flags. There are non-Python programs which also create such tags. Although it is an RFC violation and IMAP clients and servers are supposed to be strict, imaplib nonetheless continues to allow such tags to be created for backward compatibility reasons, and as of Python 3.6, handles them if they are sent from the server, since this improves real-world compatibility. -- Method: IMAP4.subscribe (mailbox) Subscribe to new mailbox. -- Method: IMAP4.thread (threading_algorithm, charset, search_criterion[, ...]) The ‘thread’ command is a variant of ‘search’ with threading semantics for the results. Returned data contains a space separated list of thread members. Thread members consist of zero or more messages numbers, delimited by spaces, indicating successive parent and child. Thread has two arguments before the `search_criterion' argument(s); a `threading_algorithm', and the searching `charset'. Note that unlike ‘search’, the searching `charset' argument is mandatory. There is also a ‘uid thread’ command which corresponds to ‘thread’ the way that ‘uid search’ corresponds to ‘search’. The ‘thread’ command first searches the mailbox for messages that match the given searching criteria using the charset argument for the interpretation of strings in the searching criteria. It then returns the matching messages threaded according to the specified threading algorithm. This is an ‘IMAP4rev1’ extension command. -- Method: IMAP4.uid (command, arg[, ...]) Execute command args with messages identified by UID, rather than message number. Returns response appropriate to command. At least one argument must be supplied; if none are provided, the server will return an error and an exception will be raised. -- Method: IMAP4.unsubscribe (mailbox) Unsubscribe from old mailbox. -- Method: IMAP4.xatom (name[, ...]) Allow simple extension commands notified by server in ‘CAPABILITY’ response. The following attributes are defined on instances of *note IMAP4: 60b.: -- Attribute: IMAP4.PROTOCOL_VERSION The most recent supported protocol in the ‘CAPABILITY’ response from the server. -- Attribute: IMAP4.debug Integer value to control debugging output. The initialize value is taken from the module variable ‘Debug’. Values greater than three trace each command. -- Attribute: IMAP4.utf8_enabled Boolean value that is normally ‘False’, but is set to ‘True’ if an *note enable(): 6ea. command is successfully issued for the ‘UTF8=ACCEPT’ capability. New in version 3.5. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc5161.html (2) https://tools.ietf.org/html/rfc6855.html (3) https://tools.ietf.org/html/rfc6855.html (4) https://tools.ietf.org/html/rfc2342.html (5) https://tools.ietf.org/html/rfc2060.html (6) https://tools.ietf.org/html/rfc3501.html  File: python.info, Node: IMAP4 Example, Prev: IMAP4 Objects, Up: imaplib — IMAP4 protocol client 5.21.15.2 IMAP4 Example ....................... Here is a minimal example (without error checking) that opens a mailbox and retrieves and prints all messages: import getpass, imaplib M = imaplib.IMAP4() M.login(getpass.getuser(), getpass.getpass()) M.select() typ, data = M.search(None, 'ALL') for num in data[0].split(): typ, data = M.fetch(num, '(RFC822)') print('Message %s\n%s\n' % (num, data[0][1])) M.close() M.logout()  File: python.info, Node: nntplib — NNTP protocol client, Next: smtplib — SMTP protocol client, Prev: imaplib — IMAP4 protocol client, Up: Internet Protocols and Support 5.21.16 ‘nntplib’ — NNTP protocol client ---------------------------------------- `Source code:' Lib/nntplib.py(1) __________________________________________________________________ This module defines the class *note NNTP: a2c. which implements the client side of the Network News Transfer Protocol. It can be used to implement a news reader or poster, or automated news processors. It is compatible with RFC 3977(2) as well as the older RFC 977(3) and RFC 2980(4). Here are two small examples of how it can be used. To list some statistics about a newsgroup and print the subjects of the last 10 articles: >>> s = nntplib.NNTP('news.gmane.io') >>> resp, count, first, last, name = s.group('gmane.comp.python.committers') >>> print('Group', name, 'has', count, 'articles, range', first, 'to', last) Group gmane.comp.python.committers has 1096 articles, range 1 to 1096 >>> resp, overviews = s.over((last - 9, last)) >>> for id, over in overviews: ... print(id, nntplib.decode_header(over['subject'])) ... 1087 Re: Commit privileges for Łukasz Langa 1088 Re: 3.2 alpha 2 freeze 1089 Re: 3.2 alpha 2 freeze 1090 Re: Commit privileges for Łukasz Langa 1091 Re: Commit privileges for Łukasz Langa 1092 Updated ssh key 1093 Re: Updated ssh key 1094 Re: Updated ssh key 1095 Hello fellow committers! 1096 Re: Hello fellow committers! >>> s.quit() '205 Bye!' To post an article from a binary file (this assumes that the article has valid headers, and that you have right to post on the particular newsgroup): >>> s = nntplib.NNTP('news.gmane.io') >>> f = open('article.txt', 'rb') >>> s.post(f) '240 Article posted successfully.' >>> s.quit() '205 Bye!' The module itself defines the following classes: -- Class: nntplib.NNTP (host, port=119, user=None, password=None, readermode=None, usenetrc=False[, timeout]) Return a new *note NNTP: a2c. object, representing a connection to the NNTP server running on host `host', listening at port `port'. An optional `timeout' can be specified for the socket connection. If the optional `user' and `password' are provided, or if suitable credentials are present in ‘/.netrc’ and the optional flag `usenetrc' is true, the ‘AUTHINFO USER’ and ‘AUTHINFO PASS’ commands are used to identify and authenticate the user to the server. If the optional flag `readermode' is true, then a ‘mode reader’ command is sent before authentication is performed. Reader mode is sometimes necessary if you are connecting to an NNTP server on the local machine and intend to call reader-specific commands, such as ‘group’. If you get unexpected *note NNTPPermanentError: 2a8f.s, you might need to set `readermode'. The *note NNTP: a2c. class supports the *note with: 6e9. statement to unconditionally consume *note OSError: 1d3. exceptions and to close the NNTP connection when done, e.g.: >>> from nntplib import NNTP >>> with NNTP('news.gmane.io') as n: ... n.group('gmane.comp.python.committers') ... ('211 1755 1 1755 gmane.comp.python.committers', 1755, 1, 1755, 'gmane.comp.python.committers') >>> Raises an *note auditing event: fd1. ‘nntplib.connect’ with arguments ‘self’, ‘host’, ‘port’. All commands will raise an *note auditing event: fd1. ‘nntplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is the bytes about to be sent to the remote host. Changed in version 3.2: `usenetrc' is now ‘False’ by default. Changed in version 3.3: Support for the *note with: 6e9. statement was added. -- Class: nntplib.NNTP_SSL (host, port=563, user=None, password=None, ssl_context=None, readermode=None, usenetrc=False[, timeout]) Return a new *note NNTP_SSL: ba5. object, representing an encrypted connection to the NNTP server running on host `host', listening at port `port'. *note NNTP_SSL: ba5. objects have the same methods as *note NNTP: a2c. objects. If `port' is omitted, port 563 (NNTPS) is used. `ssl_context' is also optional, and is a *note SSLContext: 3e4. object. Please read *note Security considerations: 22a2. for best practices. All other parameters behave the same as for *note NNTP: a2c. Note that SSL-on-563 is discouraged per RFC 4642(5), in favor of STARTTLS as described below. However, some servers only support the former. Raises an *note auditing event: fd1. ‘nntplib.connect’ with arguments ‘self’, ‘host’, ‘port’. All commands will raise an *note auditing event: fd1. ‘nntplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is the bytes about to be sent to the remote host. New in version 3.2. Changed in version 3.4: The class now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). -- Exception: nntplib.NNTPError Derived from the standard exception *note Exception: 1a9, this is the base class for all exceptions raised by the *note nntplib: c0. module. Instances of this class have the following attribute: -- Attribute: response The response of the server if available, as a *note str: 330. object. -- Exception: nntplib.NNTPReplyError Exception raised when an unexpected reply is received from the server. -- Exception: nntplib.NNTPTemporaryError Exception raised when a response code in the range 400–499 is received. -- Exception: nntplib.NNTPPermanentError Exception raised when a response code in the range 500–599 is received. -- Exception: nntplib.NNTPProtocolError Exception raised when a reply is received from the server that does not begin with a digit in the range 1–5. -- Exception: nntplib.NNTPDataError Exception raised when there is some error in the response data. * Menu: * NNTP Objects:: * Utility functions: Utility functions<2>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/nntplib.py (2) https://tools.ietf.org/html/rfc3977.html (3) https://tools.ietf.org/html/rfc977.html (4) https://tools.ietf.org/html/rfc2980.html (5) https://tools.ietf.org/html/rfc4642.html  File: python.info, Node: NNTP Objects, Next: Utility functions<2>, Up: nntplib — NNTP protocol client 5.21.16.1 NNTP Objects ...................... When connected, *note NNTP: a2c. and *note NNTP_SSL: ba5. objects support the following methods and attributes. * Menu: * Attributes:: * Methods: Methods<3>.  File: python.info, Node: Attributes, Next: Methods<3>, Up: NNTP Objects 5.21.16.2 Attributes .................... -- Attribute: NNTP.nntp_version An integer representing the version of the NNTP protocol supported by the server. In practice, this should be ‘2’ for servers advertising RFC 3977(1) compliance and ‘1’ for others. New in version 3.2. -- Attribute: NNTP.nntp_implementation A string describing the software name and version of the NNTP server, or *note None: 157. if not advertised by the server. New in version 3.2. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc3977.html  File: python.info, Node: Methods<3>, Prev: Attributes, Up: NNTP Objects 5.21.16.3 Methods ................. The `response' that is returned as the first item in the return tuple of almost all methods is the server’s response: a string beginning with a three-digit code. If the server’s response indicates an error, the method raises one of the above exceptions. Many of the following methods take an optional keyword-only argument `file'. When the `file' argument is supplied, it must be either a *note file object: b42. opened for binary writing, or the name of an on-disk file to be written to. The method will then write any data returned by the server (except for the response line and the terminating dot) to the file; any list of lines, tuples or objects that the method normally returns will be empty. Changed in version 3.2: Many of the following methods have been reworked and fixed, which makes them incompatible with their 3.1 counterparts. -- Method: NNTP.quit () Send a ‘QUIT’ command and close the connection. Once this method has been called, no other methods of the NNTP object should be called. -- Method: NNTP.getwelcome () Return the welcome message sent by the server in reply to the initial connection. (This message sometimes contains disclaimers or help information that may be relevant to the user.) -- Method: NNTP.getcapabilities () Return the RFC 3977(1) capabilities advertised by the server, as a *note dict: 1b8. instance mapping capability names to (possibly empty) lists of values. On legacy servers which don’t understand the ‘CAPABILITIES’ command, an empty dictionary is returned instead. >>> s = NNTP('news.gmane.io') >>> 'POST' in s.getcapabilities() True New in version 3.2. -- Method: NNTP.login (user=None, password=None, usenetrc=True) Send ‘AUTHINFO’ commands with the user name and password. If `user' and `password' are ‘None’ and `usenetrc' is true, credentials from ‘~/.netrc’ will be used if possible. Unless intentionally delayed, login is normally performed during the *note NNTP: a2c. object initialization and separately calling this function is unnecessary. To force authentication to be delayed, you must not set `user' or `password' when creating the object, and must set `usenetrc' to False. New in version 3.2. -- Method: NNTP.starttls (context=None) Send a ‘STARTTLS’ command. This will enable encryption on the NNTP connection. The `context' argument is optional and should be a *note ssl.SSLContext: 3e4. object. Please read *note Security considerations: 22a2. for best practices. Note that this may not be done after authentication information has been transmitted, and authentication occurs by default if possible during a *note NNTP: a2c. object initialization. See *note NNTP.login(): 2a9f. for information on suppressing this behavior. New in version 3.2. Changed in version 3.4: The method now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). -- Method: NNTP.newgroups (date, *, file=None) Send a ‘NEWGROUPS’ command. The `date' argument should be a *note datetime.date: 193. or *note datetime.datetime: 194. object. Return a pair ‘(response, groups)’ where `groups' is a list representing the groups that are new since the given `date'. If `file' is supplied, though, then `groups' will be empty. >>> from datetime import date, timedelta >>> resp, groups = s.newgroups(date.today() - timedelta(days=3)) >>> len(groups) 85 >>> groups[0] GroupInfo(group='gmane.network.tor.devel', last='4', first='1', flag='m') -- Method: NNTP.newnews (group, date, *, file=None) Send a ‘NEWNEWS’ command. Here, `group' is a group name or ‘'*'’, and `date' has the same meaning as for *note newgroups(): 2aa0. Return a pair ‘(response, articles)’ where `articles' is a list of message ids. This command is frequently disabled by NNTP server administrators. -- Method: NNTP.list (group_pattern=None, *, file=None) Send a ‘LIST’ or ‘LIST ACTIVE’ command. Return a pair ‘(response, list)’ where `list' is a list of tuples representing all the groups available from this NNTP server, optionally matching the pattern string `group_pattern'. Each tuple has the form ‘(group, last, first, flag)’, where `group' is a group name, `last' and `first' are the last and first article numbers, and `flag' usually takes one of these values: * ‘y’: Local postings and articles from peers are allowed. * ‘m’: The group is moderated and all postings must be approved. * ‘n’: No local postings are allowed, only articles from peers. * ‘j’: Articles from peers are filed in the junk group instead. * ‘x’: No local postings, and articles from peers are ignored. * ‘=foo.bar’: Articles are filed in the ‘foo.bar’ group instead. If `flag' has another value, then the status of the newsgroup should be considered unknown. This command can return very large results, especially if `group_pattern' is not specified. It is best to cache the results offline unless you really need to refresh them. Changed in version 3.2: `group_pattern' was added. -- Method: NNTP.descriptions (grouppattern) Send a ‘LIST NEWSGROUPS’ command, where `grouppattern' is a wildmat string as specified in RFC 3977(2) (it’s essentially the same as DOS or UNIX shell wildcard strings). Return a pair ‘(response, descriptions)’, where `descriptions' is a dictionary mapping group names to textual descriptions. >>> resp, descs = s.descriptions('gmane.comp.python.*') >>> len(descs) 295 >>> descs.popitem() ('gmane.comp.python.bio.general', 'BioPython discussion list (Moderated)') -- Method: NNTP.description (group) Get a description for a single group `group'. If more than one group matches (if ‘group’ is a real wildmat string), return the first match. If no group matches, return an empty string. This elides the response code from the server. If the response code is needed, use *note descriptions(): 2aa3. -- Method: NNTP.group (name) Send a ‘GROUP’ command, where `name' is the group name. The group is selected as the current group, if it exists. Return a tuple ‘(response, count, first, last, name)’ where `count' is the (estimated) number of articles in the group, `first' is the first article number in the group, `last' is the last article number in the group, and `name' is the group name. -- Method: NNTP.over (message_spec, *, file=None) Send an ‘OVER’ command, or an ‘XOVER’ command on legacy servers. `message_spec' can be either a string representing a message id, or a ‘(first, last)’ tuple of numbers indicating a range of articles in the current group, or a ‘(first, None)’ tuple indicating a range of articles starting from `first' to the last article in the current group, or *note None: 157. to select the current article in the current group. Return a pair ‘(response, overviews)’. `overviews' is a list of ‘(article_number, overview)’ tuples, one for each article selected by `message_spec'. Each `overview' is a dictionary with the same number of items, but this number depends on the server. These items are either message headers (the key is then the lower-cased header name) or metadata items (the key is then the metadata name prepended with ‘":"’). The following items are guaranteed to be present by the NNTP specification: * the ‘subject’, ‘from’, ‘date’, ‘message-id’ and ‘references’ headers * the ‘:bytes’ metadata: the number of bytes in the entire raw article (including headers and body) * the ‘:lines’ metadata: the number of lines in the article body The value of each item is either a string, or *note None: 157. if not present. It is advisable to use the *note decode_header(): 2aa7. function on header values when they may contain non-ASCII characters: >>> _, _, first, last, _ = s.group('gmane.comp.python.devel') >>> resp, overviews = s.over((last, last)) >>> art_num, over = overviews[0] >>> art_num 117216 >>> list(over.keys()) ['xref', 'from', ':lines', ':bytes', 'references', 'date', 'message-id', 'subject'] >>> over['from'] '=?UTF-8?B?Ik1hcnRpbiB2LiBMw7Z3aXMi?= <martin@v.loewis.de>' >>> nntplib.decode_header(over['from']) '"Martin v. Löwis" <martin@v.loewis.de>' New in version 3.2. -- Method: NNTP.help (*, file=None) Send a ‘HELP’ command. Return a pair ‘(response, list)’ where `list' is a list of help strings. -- Method: NNTP.stat (message_spec=None) Send a ‘STAT’ command, where `message_spec' is either a message id (enclosed in ‘'<'’ and ‘'>'’) or an article number in the current group. If `message_spec' is omitted or *note None: 157, the current article in the current group is considered. Return a triple ‘(response, number, id)’ where `number' is the article number and `id' is the message id. >>> _, _, first, last, _ = s.group('gmane.comp.python.devel') >>> resp, number, message_id = s.stat(first) >>> number, message_id (9099, '<20030112190404.GE29873@epoch.metaslash.com>') -- Method: NNTP.next () Send a ‘NEXT’ command. Return as for *note stat(): 2aa9. -- Method: NNTP.last () Send a ‘LAST’ command. Return as for *note stat(): 2aa9. -- Method: NNTP.article (message_spec=None, *, file=None) Send an ‘ARTICLE’ command, where `message_spec' has the same meaning as for *note stat(): 2aa9. Return a tuple ‘(response, info)’ where `info' is a *note namedtuple: 1b7. with three attributes `number', `message_id' and `lines' (in that order). `number' is the article number in the group (or 0 if the information is not available), `message_id' the message id as a string, and `lines' a list of lines (without terminating newlines) comprising the raw message including headers and body. >>> resp, info = s.article('<20030112190404.GE29873@epoch.metaslash.com>') >>> info.number 0 >>> info.message_id '<20030112190404.GE29873@epoch.metaslash.com>' >>> len(info.lines) 65 >>> info.lines[0] b'Path: main.gmane.org!not-for-mail' >>> info.lines[1] b'From: Neal Norwitz <neal@metaslash.com>' >>> info.lines[-3:] [b'There is a patch for 2.3 as well as 2.2.', b'', b'Neal'] -- Method: NNTP.head (message_spec=None, *, file=None) Same as *note article(): 2aac, but sends a ‘HEAD’ command. The `lines' returned (or written to `file') will only contain the message headers, not the body. -- Method: NNTP.body (message_spec=None, *, file=None) Same as *note article(): 2aac, but sends a ‘BODY’ command. The `lines' returned (or written to `file') will only contain the message body, not the headers. -- Method: NNTP.post (data) Post an article using the ‘POST’ command. The `data' argument is either a *note file object: b42. opened for binary reading, or any iterable of bytes objects (representing raw lines of the article to be posted). It should represent a well-formed news article, including the required headers. The *note post(): 2aaf. method automatically escapes lines beginning with ‘.’ and appends the termination line. If the method succeeds, the server’s response is returned. If the server refuses posting, a *note NNTPReplyError: 2a92. is raised. -- Method: NNTP.ihave (message_id, data) Send an ‘IHAVE’ command. `message_id' is the id of the message to send to the server (enclosed in ‘'<'’ and ‘'>'’). The `data' parameter and the return value are the same as for *note post(): 2aaf. -- Method: NNTP.date () Return a pair ‘(response, date)’. `date' is a *note datetime: 194. object containing the current date and time of the server. -- Method: NNTP.slave () Send a ‘SLAVE’ command. Return the server’s `response'. -- Method: NNTP.set_debuglevel (level) Set the instance’s debugging level. This controls the amount of debugging output printed. The default, ‘0’, produces no debugging output. A value of ‘1’ produces a moderate amount of debugging output, generally a single line per request or response. A value of ‘2’ or higher produces the maximum amount of debugging output, logging each line sent and received on the connection (including message text). The following are optional NNTP extensions defined in RFC 2980(3). Some of them have been superseded by newer commands in RFC 3977(4). -- Method: NNTP.xhdr (hdr, str, *, file=None) Send an ‘XHDR’ command. The `hdr' argument is a header keyword, e.g. ‘'subject'’. The `str' argument should have the form ‘'first-last'’ where `first' and `last' are the first and last article numbers to search. Return a pair ‘(response, list)’, where `list' is a list of pairs ‘(id, text)’, where `id' is an article number (as a string) and `text' is the text of the requested header for that article. If the `file' parameter is supplied, then the output of the ‘XHDR’ command is stored in a file. If `file' is a string, then the method will open a file with that name, write to it then close it. If `file' is a *note file object: b42, then it will start calling ‘write()’ on it to store the lines of the command output. If `file' is supplied, then the returned `list' is an empty list. -- Method: NNTP.xover (start, end, *, file=None) Send an ‘XOVER’ command. `start' and `end' are article numbers delimiting the range of articles to select. The return value is the same of for *note over(): 2aa6. It is recommended to use *note over(): 2aa6. instead, since it will automatically use the newer ‘OVER’ command if available. -- Method: NNTP.xpath (id) Return a pair ‘(resp, path)’, where `path' is the directory path to the article with message ID `id'. Most of the time, this extension is not enabled by NNTP server administrators. Deprecated since version 3.3: The XPATH extension is not actively used. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc3977.html (2) https://tools.ietf.org/html/rfc3977.html (3) https://tools.ietf.org/html/rfc2980.html (4) https://tools.ietf.org/html/rfc3977.html  File: python.info, Node: Utility functions<2>, Prev: NNTP Objects, Up: nntplib — NNTP protocol client 5.21.16.4 Utility functions ........................... The module also defines the following utility function: -- Function: nntplib.decode_header (header_str) Decode a header value, un-escaping any escaped non-ASCII characters. `header_str' must be a *note str: 330. object. The unescaped value is returned. Using this function is recommended to display some headers in a human readable form: >>> decode_header("Some subject") 'Some subject' >>> decode_header("=?ISO-8859-15?Q?D=E9buter_en_Python?=") 'Débuter en Python' >>> decode_header("Re: =?UTF-8?B?cHJvYmzDqG1lIGRlIG1hdHJpY2U=?=") 'Re: problème de matrice'  File: python.info, Node: smtplib — SMTP protocol client, Next: smtpd — SMTP Server, Prev: nntplib — NNTP protocol client, Up: Internet Protocols and Support 5.21.17 ‘smtplib’ — SMTP protocol client ---------------------------------------- `Source code:' Lib/smtplib.py(1) __________________________________________________________________ The *note smtplib: ed. module defines an SMTP client session object that can be used to send mail to any Internet machine with an SMTP or ESMTP listener daemon. For details of SMTP and ESMTP operation, consult RFC 821(2) (Simple Mail Transfer Protocol) and RFC 1869(3) (SMTP Service Extensions). -- Class: smtplib.SMTP (host='', port=0, local_hostname=None[, timeout], source_address=None) An *note SMTP: a81. instance encapsulates an SMTP connection. It has methods that support a full repertoire of SMTP and ESMTP operations. If the optional host and port parameters are given, the SMTP *note connect(): 2aba. method is called with those parameters during initialization. If specified, `local_hostname' is used as the FQDN of the local host in the HELO/EHLO command. Otherwise, the local hostname is found using *note socket.getfqdn(): 2381. If the *note connect(): 2aba. call returns anything other than a success code, an *note SMTPConnectError: 2abb. is raised. The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). If the timeout expires, *note socket.timeout: c0e. is raised. The optional source_address parameter allows binding to some specific source address in a machine with multiple network interfaces, and/or to some specific source TCP port. It takes a 2-tuple (host, port), for the socket to bind to as its source address before connecting. If omitted (or if host or port are ‘''’ and/or 0 respectively) the OS default behavior will be used. For normal use, you should only require the initialization/connect, *note sendmail(): 744, and *note SMTP.quit(): 2abc. methods. An example is included below. The *note SMTP: a81. class supports the *note with: 6e9. statement. When used like this, the SMTP ‘QUIT’ command is issued automatically when the ‘with’ statement exits. E.g.: >>> from smtplib import SMTP >>> with SMTP("domain.org") as smtp: ... smtp.noop() ... (250, b'Ok') >>> All commands will raise an *note auditing event: fd1. ‘smtplib.SMTP.send’ with arguments ‘self’ and ‘data’, where ‘data’ is the bytes about to be sent to the remote host. Changed in version 3.3: Support for the *note with: 6e9. statement was added. Changed in version 3.3: source_address argument was added. New in version 3.5: The SMTPUTF8 extension ( RFC 6531(4)) is now supported. -- Class: smtplib.SMTP_SSL (host='', port=0, local_hostname=None, keyfile=None, certfile=None[, timeout], context=None, source_address=None) An *note SMTP_SSL: a82. instance behaves exactly the same as instances of *note SMTP: a81. *note SMTP_SSL: a82. should be used for situations where SSL is required from the beginning of the connection and using ‘starttls()’ is not appropriate. If `host' is not specified, the local host is used. If `port' is zero, the standard SMTP-over-SSL port (465) is used. The optional arguments `local_hostname', `timeout' and `source_address' have the same meaning as they do in the *note SMTP: a81. class. `context', also optional, can contain a *note SSLContext: 3e4. and allows configuring various aspects of the secure connection. Please read *note Security considerations: 22a2. for best practices. `keyfile' and `certfile' are a legacy alternative to `context', and can point to a PEM formatted private key and certificate chain file for the SSL connection. Changed in version 3.3: `context' was added. Changed in version 3.3: source_address argument was added. Changed in version 3.4: The class now supports hostname check with *note ssl.SSLContext.check_hostname: 23bd. and `Server Name Indication' (see *note ssl.HAS_SNI: 23d2.). Deprecated since version 3.6: `keyfile' and `certfile' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. -- Class: smtplib.LMTP (host='', port=LMTP_PORT, local_hostname=None, source_address=None) The LMTP protocol, which is very similar to ESMTP, is heavily based on the standard SMTP client. It’s common to use Unix sockets for LMTP, so our ‘connect()’ method must support that as well as a regular host:port server. The optional arguments local_hostname and source_address have the same meaning as they do in the *note SMTP: a81. class. To specify a Unix socket, you must use an absolute path for `host', starting with a ‘/’. Authentication is supported, using the regular SMTP mechanism. When using a Unix socket, LMTP generally don’t support or require any authentication, but your mileage might vary. A nice selection of exceptions is defined as well: -- Exception: smtplib.SMTPException Subclass of *note OSError: 1d3. that is the base exception class for all the other exceptions provided by this module. Changed in version 3.4: SMTPException became subclass of *note OSError: 1d3. -- Exception: smtplib.SMTPServerDisconnected This exception is raised when the server unexpectedly disconnects, or when an attempt is made to use the *note SMTP: a81. instance before connecting it to a server. -- Exception: smtplib.SMTPResponseException Base class for all exceptions that include an SMTP error code. These exceptions are generated in some instances when the SMTP server returns an error code. The error code is stored in the ‘smtp_code’ attribute of the error, and the ‘smtp_error’ attribute is set to the error message. -- Exception: smtplib.SMTPSenderRefused Sender address refused. In addition to the attributes set by on all *note SMTPResponseException: 2abe. exceptions, this sets ‘sender’ to the string that the SMTP server refused. -- Exception: smtplib.SMTPRecipientsRefused All recipient addresses refused. The errors for each recipient are accessible through the attribute ‘recipients’, which is a dictionary of exactly the same sort as *note SMTP.sendmail(): 744. returns. -- Exception: smtplib.SMTPDataError The SMTP server refused to accept the message data. -- Exception: smtplib.SMTPConnectError Error occurred during establishment of a connection with the server. -- Exception: smtplib.SMTPHeloError The server refused our ‘HELO’ message. -- Exception: smtplib.SMTPNotSupportedError The command or option attempted is not supported by the server. New in version 3.5. -- Exception: smtplib.SMTPAuthenticationError SMTP authentication went wrong. Most probably the server didn’t accept the username/password combination provided. See also ........ RFC 821(5) - Simple Mail Transfer Protocol Protocol definition for SMTP. This document covers the model, operating procedure, and protocol details for SMTP. RFC 1869(6) - SMTP Service Extensions Definition of the ESMTP extensions for SMTP. This describes a framework for extending SMTP with new commands, supporting dynamic discovery of the commands provided by the server, and defines a few additional commands. * Menu: * SMTP Objects:: * SMTP Example:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/smtplib.py (2) https://tools.ietf.org/html/rfc821.html (3) https://tools.ietf.org/html/rfc1869.html (4) https://tools.ietf.org/html/rfc6531.html (5) https://tools.ietf.org/html/rfc821.html (6) https://tools.ietf.org/html/rfc1869.html  File: python.info, Node: SMTP Objects, Next: SMTP Example, Up: smtplib — SMTP protocol client 5.21.17.1 SMTP Objects ...................... An *note SMTP: a81. instance has the following methods: -- Method: SMTP.set_debuglevel (level) Set the debug output level. A value of 1 or ‘True’ for `level' results in debug messages for connection and for all messages sent to and received from the server. A value of 2 for `level' results in these messages being timestamped. Changed in version 3.5: Added debuglevel 2. -- Method: SMTP.docmd (cmd, args='') Send a command `cmd' to the server. The optional argument `args' is simply concatenated to the command, separated by a space. This returns a 2-tuple composed of a numeric response code and the actual response line (multiline responses are joined into one long line.) In normal operation it should not be necessary to call this method explicitly. It is used to implement other methods and may be useful for testing private extensions. If the connection to the server is lost while waiting for the reply, *note SMTPServerDisconnected: 2abd. will be raised. -- Method: SMTP.connect (host='localhost', port=0) Connect to a host on a given port. The defaults are to connect to the local host at the standard SMTP port (25). If the hostname ends with a colon (‘':'’) followed by a number, that suffix will be stripped off and the number interpreted as the port number to use. This method is automatically invoked by the constructor if a host is specified during instantiation. Returns a 2-tuple of the response code and message sent by the server in its connection response. Raises an *note auditing event: fd1. ‘smtplib.connect’ with arguments ‘self’, ‘host’, ‘port’. -- Method: SMTP.helo (name='') Identify yourself to the SMTP server using ‘HELO’. The hostname argument defaults to the fully qualified domain name of the local host. The message returned by the server is stored as the ‘helo_resp’ attribute of the object. In normal operation it should not be necessary to call this method explicitly. It will be implicitly called by the *note sendmail(): 744. when necessary. -- Method: SMTP.ehlo (name='') Identify yourself to an ESMTP server using ‘EHLO’. The hostname argument defaults to the fully qualified domain name of the local host. Examine the response for ESMTP option and store them for use by *note has_extn(): 2aca. Also sets several informational attributes: the message returned by the server is stored as the ‘ehlo_resp’ attribute, ‘does_esmtp’ is set to true or false depending on whether the server supports ESMTP, and ‘esmtp_features’ will be a dictionary containing the names of the SMTP service extensions this server supports, and their parameters (if any). Unless you wish to use *note has_extn(): 2aca. before sending mail, it should not be necessary to call this method explicitly. It will be implicitly called by *note sendmail(): 744. when necessary. -- Method: SMTP.ehlo_or_helo_if_needed () This method calls *note ehlo(): 2ac9. and/or *note helo(): 2ac8. if there has been no previous ‘EHLO’ or ‘HELO’ command this session. It tries ESMTP ‘EHLO’ first. *note SMTPHeloError: 2ac2. The server didn’t reply properly to the ‘HELO’ greeting. -- Method: SMTP.has_extn (name) Return *note True: 499. if `name' is in the set of SMTP service extensions returned by the server, *note False: 388. otherwise. Case is ignored. -- Method: SMTP.verify (address) Check the validity of an address on this server using SMTP ‘VRFY’. Returns a tuple consisting of code 250 and a full RFC 822(1) address (including human name) if the user address is valid. Otherwise returns an SMTP error code of 400 or greater and an error string. Note: Many sites disable SMTP ‘VRFY’ in order to foil spammers. -- Method: SMTP.login (user, password, *, initial_response_ok=True) Log in on an SMTP server that requires authentication. The arguments are the username and the password to authenticate with. If there has been no previous ‘EHLO’ or ‘HELO’ command this session, this method tries ESMTP ‘EHLO’ first. This method will return normally if the authentication was successful, or may raise the following exceptions: *note SMTPHeloError: 2ac2. The server didn’t reply properly to the ‘HELO’ greeting. *note SMTPAuthenticationError: 2ac4. The server didn’t accept the username/password combination. *note SMTPNotSupportedError: 2ac3. The ‘AUTH’ command is not supported by the server. *note SMTPException: 8b7. No suitable authentication method was found. Each of the authentication methods supported by *note smtplib: ed. are tried in turn if they are advertised as supported by the server. See *note auth(): 742. for a list of supported authentication methods. `initial_response_ok' is passed through to *note auth(): 742. Optional keyword argument `initial_response_ok' specifies whether, for authentication methods that support it, an “initial response” as specified in RFC 4954(2) can be sent along with the ‘AUTH’ command, rather than requiring a challenge/response. Changed in version 3.5: *note SMTPNotSupportedError: 2ac3. may be raised, and the `initial_response_ok' parameter was added. -- Method: SMTP.auth (mechanism, authobject, *, initial_response_ok=True) Issue an ‘SMTP’ ‘AUTH’ command for the specified authentication `mechanism', and handle the challenge response via `authobject'. `mechanism' specifies which authentication mechanism is to be used as argument to the ‘AUTH’ command; the valid values are those listed in the ‘auth’ element of ‘esmtp_features’. `authobject' must be a callable object taking an optional single argument: data = authobject(challenge=None) If optional keyword argument `initial_response_ok' is true, ‘authobject()’ will be called first with no argument. It can return the RFC 4954(3) “initial response” ASCII ‘str’ which will be encoded and sent with the ‘AUTH’ command as below. If the ‘authobject()’ does not support an initial response (e.g. because it requires a challenge), it should return ‘None’ when called with ‘challenge=None’. If `initial_response_ok' is false, then ‘authobject()’ will not be called first with ‘None’. If the initial response check returns ‘None’, or if `initial_response_ok' is false, ‘authobject()’ will be called to process the server’s challenge response; the `challenge' argument it is passed will be a ‘bytes’. It should return ASCII ‘str’ `data' that will be base64 encoded and sent to the server. The ‘SMTP’ class provides ‘authobjects’ for the ‘CRAM-MD5’, ‘PLAIN’, and ‘LOGIN’ mechanisms; they are named ‘SMTP.auth_cram_md5’, ‘SMTP.auth_plain’, and ‘SMTP.auth_login’ respectively. They all require that the ‘user’ and ‘password’ properties of the ‘SMTP’ instance are set to appropriate values. User code does not normally need to call ‘auth’ directly, but can instead call the *note login(): 2acd. method, which will try each of the above mechanisms in turn, in the order listed. ‘auth’ is exposed to facilitate the implementation of authentication methods not (or not yet) supported directly by *note smtplib: ed. New in version 3.5. -- Method: SMTP.starttls (keyfile=None, certfile=None, context=None) Put the SMTP connection in TLS (Transport Layer Security) mode. All SMTP commands that follow will be encrypted. You should then call *note ehlo(): 2ac9. again. If `keyfile' and `certfile' are provided, they are used to create an *note ssl.SSLContext: 3e4. Optional `context' parameter is an *note ssl.SSLContext: 3e4. object; This is an alternative to using a keyfile and a certfile and if specified both `keyfile' and `certfile' should be ‘None’. If there has been no previous ‘EHLO’ or ‘HELO’ command this session, this method tries ESMTP ‘EHLO’ first. Deprecated since version 3.6: `keyfile' and `certfile' are deprecated in favor of `context'. Please use *note ssl.SSLContext.load_cert_chain(): a91. instead, or let *note ssl.create_default_context(): 8c1. select the system’s trusted CA certificates for you. *note SMTPHeloError: 2ac2. The server didn’t reply properly to the ‘HELO’ greeting. *note SMTPNotSupportedError: 2ac3. The server does not support the STARTTLS extension. *note RuntimeError: 2ba. SSL/TLS support is not available to your Python interpreter. Changed in version 3.3: `context' was added. Changed in version 3.4: The method now supports hostname check with ‘SSLContext.check_hostname’ and `Server Name Indicator' (see *note HAS_SNI: 23d2.). Changed in version 3.5: The error raised for lack of STARTTLS support is now the *note SMTPNotSupportedError: 2ac3. subclass instead of the base *note SMTPException: 8b7. -- Method: SMTP.sendmail (from_addr, to_addrs, msg, mail_options=(), rcpt_options=()) Send mail. The required arguments are an RFC 822(4) from-address string, a list of RFC 822(5) to-address strings (a bare string will be treated as a list with 1 address), and a message string. The caller may pass a list of ESMTP options (such as ‘8bitmime’) to be used in ‘MAIL FROM’ commands as `mail_options'. ESMTP options (such as ‘DSN’ commands) that should be used with all ‘RCPT’ commands can be passed as `rcpt_options'. (If you need to use different ESMTP options to different recipients you have to use the low-level methods such as ‘mail()’, ‘rcpt()’ and ‘data()’ to send the message.) Note: The `from_addr' and `to_addrs' parameters are used to construct the message envelope used by the transport agents. ‘sendmail’ does not modify the message headers in any way. `msg' may be a string containing characters in the ASCII range, or a byte string. A string is encoded to bytes using the ascii codec, and lone ‘\r’ and ‘\n’ characters are converted to ‘\r\n’ characters. A byte string is not modified. If there has been no previous ‘EHLO’ or ‘HELO’ command this session, this method tries ESMTP ‘EHLO’ first. If the server does ESMTP, message size and each of the specified options will be passed to it (if the option is in the feature set the server advertises). If ‘EHLO’ fails, ‘HELO’ will be tried and ESMTP options suppressed. This method will return normally if the mail is accepted for at least one recipient. Otherwise it will raise an exception. That is, if this method does not raise an exception, then someone should get your mail. If this method does not raise an exception, it returns a dictionary, with one entry for each recipient that was refused. Each entry contains a tuple of the SMTP error code and the accompanying error message sent by the server. If ‘SMTPUTF8’ is included in `mail_options', and the server supports it, `from_addr' and `to_addrs' may contain non-ASCII characters. This method may raise the following exceptions: *note SMTPRecipientsRefused: 2ac0. All recipients were refused. Nobody got the mail. The ‘recipients’ attribute of the exception object is a dictionary with information about the refused recipients (like the one returned when at least one recipient was accepted). *note SMTPHeloError: 2ac2. The server didn’t reply properly to the ‘HELO’ greeting. *note SMTPSenderRefused: 2abf. The server didn’t accept the `from_addr'. *note SMTPDataError: 2ac1. The server replied with an unexpected error code (other than a refusal of a recipient). *note SMTPNotSupportedError: 2ac3. ‘SMTPUTF8’ was given in the `mail_options' but is not supported by the server. Unless otherwise noted, the connection will be open even after an exception is raised. Changed in version 3.2: `msg' may be a byte string. Changed in version 3.5: ‘SMTPUTF8’ support added, and *note SMTPNotSupportedError: 2ac3. may be raised if ‘SMTPUTF8’ is specified but the server does not support it. -- Method: SMTP.send_message (msg, from_addr=None, to_addrs=None, mail_options=(), rcpt_options=()) This is a convenience method for calling *note sendmail(): 744. with the message represented by an *note email.message.Message: 541. object. The arguments have the same meaning as for *note sendmail(): 744, except that `msg' is a ‘Message’ object. If `from_addr' is ‘None’ or `to_addrs' is ‘None’, ‘send_message’ fills those arguments with addresses extracted from the headers of `msg' as specified in RFC 5322(6): `from_addr' is set to the ‘Sender’ field if it is present, and otherwise to the ‘From’ field. `to_addrs' combines the values (if any) of the ‘To’, ‘Cc’, and ‘Bcc’ fields from `msg'. If exactly one set of ‘Resent-*’ headers appear in the message, the regular headers are ignored and the ‘Resent-*’ headers are used instead. If the message contains more than one set of ‘Resent-*’ headers, a *note ValueError: 1fb. is raised, since there is no way to unambiguously detect the most recent set of ‘Resent-’ headers. ‘send_message’ serializes `msg' using *note BytesGenerator: b4d. with ‘\r\n’ as the `linesep', and calls *note sendmail(): 744. to transmit the resulting message. Regardless of the values of `from_addr' and `to_addrs', ‘send_message’ does not transmit any ‘Bcc’ or ‘Resent-Bcc’ headers that may appear in `msg'. If any of the addresses in `from_addr' and `to_addrs' contain non-ASCII characters and the server does not advertise ‘SMTPUTF8’ support, an ‘SMTPNotSupported’ error is raised. Otherwise the ‘Message’ is serialized with a clone of its *note policy: 75. with the *note utf8: 6d2. attribute set to ‘True’, and ‘SMTPUTF8’ and ‘BODY=8BITMIME’ are added to `mail_options'. New in version 3.2. New in version 3.5: Support for internationalized addresses (‘SMTPUTF8’). -- Method: SMTP.quit () Terminate the SMTP session and close the connection. Return the result of the SMTP ‘QUIT’ command. Low-level methods corresponding to the standard SMTP/ESMTP commands ‘HELP’, ‘RSET’, ‘NOOP’, ‘MAIL’, ‘RCPT’, and ‘DATA’ are also supported. Normally these do not need to be called directly, so they are not documented here. For details, consult the module code. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc822.html (2) https://tools.ietf.org/html/rfc4954.html (3) https://tools.ietf.org/html/rfc4954.html (4) https://tools.ietf.org/html/rfc822.html (5) https://tools.ietf.org/html/rfc822.html (6) https://tools.ietf.org/html/rfc5322.html  File: python.info, Node: SMTP Example, Prev: SMTP Objects, Up: smtplib — SMTP protocol client 5.21.17.2 SMTP Example ...................... This example prompts the user for addresses needed in the message envelope (‘To’ and ‘From’ addresses), and the message to be delivered. Note that the headers to be included with the message must be included in the message as entered; this example doesn’t do any processing of the RFC 822(1) headers. In particular, the ‘To’ and ‘From’ addresses must be included in the message headers explicitly. import smtplib def prompt(prompt): return input(prompt).strip() fromaddr = prompt("From: ") toaddrs = prompt("To: ").split() print("Enter message, end with ^D (Unix) or ^Z (Windows):") # Add the From: and To: headers at the start! msg = ("From: %s\r\nTo: %s\r\n\r\n" % (fromaddr, ", ".join(toaddrs))) while True: try: line = input() except EOFError: break if not line: break msg = msg + line print("Message length is", len(msg)) server = smtplib.SMTP('localhost') server.set_debuglevel(1) server.sendmail(fromaddr, toaddrs, msg) server.quit() Note: In general, you will want to use the *note email: 69. package’s features to construct an email message, which you can then send via *note send_message(): 745.; see *note email; Examples: 845. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc822.html  File: python.info, Node: smtpd — SMTP Server, Next: telnetlib — Telnet client, Prev: smtplib — SMTP protocol client, Up: Internet Protocols and Support 5.21.18 ‘smtpd’ — SMTP Server ----------------------------- `Source code:' Lib/smtpd.py(1) __________________________________________________________________ This module offers several classes to implement SMTP (email) servers. See also ........ The aiosmtpd(2) package is a recommended replacement for this module. It is based on *note asyncio: a. and provides a more straightforward API. *note smtpd: ec. should be considered deprecated. Several server implementations are present; one is a generic do-nothing implementation, which can be overridden, while the other two offer specific mail-sending strategies. Additionally the SMTPChannel may be extended to implement very specific interaction behaviour with SMTP clients. The code supports RFC 5321(3), plus the RFC 1870(4) SIZE and RFC 6531(5) SMTPUTF8 extensions. * Menu: * SMTPServer Objects:: * DebuggingServer Objects:: * PureProxy Objects:: * MailmanProxy Objects:: * SMTPChannel Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/smtpd.py (2) http://aiosmtpd.readthedocs.io/ (3) https://tools.ietf.org/html/rfc5321.html (4) https://tools.ietf.org/html/rfc1870.html (5) https://tools.ietf.org/html/rfc6531.html  File: python.info, Node: SMTPServer Objects, Next: DebuggingServer Objects, Up: smtpd — SMTP Server 5.21.18.1 SMTPServer Objects ............................ -- Class: smtpd.SMTPServer (localaddr, remoteaddr, data_size_limit=33554432, map=None, enable_SMTPUTF8=False, decode_data=False) Create a new *note SMTPServer: 602. object, which binds to local address `localaddr'. It will treat `remoteaddr' as an upstream SMTP relayer. Both `localaddr' and `remoteaddr' should be a *note (host, port): 235a. tuple. The object inherits from *note asyncore.dispatcher: bc3, and so will insert itself into *note asyncore: b.’s event loop on instantiation. `data_size_limit' specifies the maximum number of bytes that will be accepted in a ‘DATA’ command. A value of ‘None’ or ‘0’ means no limit. `map' is the socket map to use for connections (an initially empty dictionary is a suitable value). If not specified the *note asyncore: b. global socket map is used. `enable_SMTPUTF8' determines whether the ‘SMTPUTF8’ extension (as defined in RFC 6531(1)) should be enabled. The default is ‘False’. When ‘True’, ‘SMTPUTF8’ is accepted as a parameter to the ‘MAIL’ command and when present is passed to *note process_message(): 603. in the ‘kwargs['mail_options']’ list. `decode_data' and `enable_SMTPUTF8' cannot be set to ‘True’ at the same time. `decode_data' specifies whether the data portion of the SMTP transaction should be decoded using UTF-8. When `decode_data' is ‘False’ (the default), the server advertises the ‘8BITMIME’ extension ( RFC 6152(2)), accepts the ‘BODY=8BITMIME’ parameter to the ‘MAIL’ command, and when present passes it to *note process_message(): 603. in the ‘kwargs['mail_options']’ list. `decode_data' and `enable_SMTPUTF8' cannot be set to ‘True’ at the same time. -- Method: process_message (peer, mailfrom, rcpttos, data, **kwargs) Raise a *note NotImplementedError: 60e. exception. Override this in subclasses to do something useful with this message. Whatever was passed in the constructor as `remoteaddr' will be available as the ‘_remoteaddr’ attribute. `peer' is the remote host’s address, `mailfrom' is the envelope originator, `rcpttos' are the envelope recipients and `data' is a string containing the contents of the e-mail (which should be in RFC 5321(3) format). If the `decode_data' constructor keyword is set to ‘True’, the `data' argument will be a unicode string. If it is set to ‘False’, it will be a bytes object. `kwargs' is a dictionary containing additional information. It is empty if ‘decode_data=True’ was given as an init argument, otherwise it contains the following keys: `mail_options': a list of all received parameters to the ‘MAIL’ command (the elements are uppercase strings; example: ‘['BODY=8BITMIME', 'SMTPUTF8']’). `rcpt_options': same as `mail_options' but for the ‘RCPT’ command. Currently no ‘RCPT TO’ options are supported, so for now this will always be an empty list. Implementations of ‘process_message’ should use the ‘**kwargs’ signature to accept arbitrary keyword arguments, since future feature enhancements may add keys to the kwargs dictionary. Return ‘None’ to request a normal ‘250 Ok’ response; otherwise return the desired response string in RFC 5321(4) format. -- Attribute: channel_class Override this in subclasses to use a custom *note SMTPChannel: 601. for managing SMTP clients. New in version 3.4: The `map' constructor argument. Changed in version 3.5: `localaddr' and `remoteaddr' may now contain IPv6 addresses. New in version 3.5: The `decode_data' and `enable_SMTPUTF8' constructor parameters, and the `kwargs' parameter to *note process_message(): 603. when `decode_data' is ‘False’. Changed in version 3.6: `decode_data' is now ‘False’ by default. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc6531.html (2) https://tools.ietf.org/html/rfc6152.html (3) https://tools.ietf.org/html/rfc5321.html (4) https://tools.ietf.org/html/rfc5321.html  File: python.info, Node: DebuggingServer Objects, Next: PureProxy Objects, Prev: SMTPServer Objects, Up: smtpd — SMTP Server 5.21.18.2 DebuggingServer Objects ................................. -- Class: smtpd.DebuggingServer (localaddr, remoteaddr) Create a new debugging server. Arguments are as per *note SMTPServer: 602. Messages will be discarded, and printed on stdout.  File: python.info, Node: PureProxy Objects, Next: MailmanProxy Objects, Prev: DebuggingServer Objects, Up: smtpd — SMTP Server 5.21.18.3 PureProxy Objects ........................... -- Class: smtpd.PureProxy (localaddr, remoteaddr) Create a new pure proxy server. Arguments are as per *note SMTPServer: 602. Everything will be relayed to `remoteaddr'. Note that running this has a good chance to make you into an open relay, so please be careful.  File: python.info, Node: MailmanProxy Objects, Next: SMTPChannel Objects, Prev: PureProxy Objects, Up: smtpd — SMTP Server 5.21.18.4 MailmanProxy Objects .............................. -- Class: smtpd.MailmanProxy (localaddr, remoteaddr) Create a new pure proxy server. Arguments are as per *note SMTPServer: 602. Everything will be relayed to `remoteaddr', unless local mailman configurations knows about an address, in which case it will be handled via mailman. Note that running this has a good chance to make you into an open relay, so please be careful.  File: python.info, Node: SMTPChannel Objects, Prev: MailmanProxy Objects, Up: smtpd — SMTP Server 5.21.18.5 SMTPChannel Objects ............................. -- Class: smtpd.SMTPChannel (server, conn, addr, data_size_limit=33554432, map=None, enable_SMTPUTF8=False, decode_data=False) Create a new *note SMTPChannel: 601. object which manages the communication between the server and a single SMTP client. `conn' and `addr' are as per the instance variables described below. `data_size_limit' specifies the maximum number of bytes that will be accepted in a ‘DATA’ command. A value of ‘None’ or ‘0’ means no limit. `enable_SMTPUTF8' determines whether the ‘SMTPUTF8’ extension (as defined in RFC 6531(1)) should be enabled. The default is ‘False’. `decode_data' and `enable_SMTPUTF8' cannot be set to ‘True’ at the same time. A dictionary can be specified in `map' to avoid using a global socket map. `decode_data' specifies whether the data portion of the SMTP transaction should be decoded using UTF-8. The default is ‘False’. `decode_data' and `enable_SMTPUTF8' cannot be set to ‘True’ at the same time. To use a custom SMTPChannel implementation you need to override the *note SMTPServer.channel_class: 2ad3. of your *note SMTPServer: 602. Changed in version 3.5: The `decode_data' and `enable_SMTPUTF8' parameters were added. Changed in version 3.6: `decode_data' is now ‘False’ by default. The *note SMTPChannel: 601. has the following instance variables: -- Attribute: smtp_server Holds the *note SMTPServer: 602. that spawned this channel. -- Attribute: conn Holds the socket object connecting to the client. -- Attribute: addr Holds the address of the client, the second value returned by *note socket.accept: 675. -- Attribute: received_lines Holds a list of the line strings (decoded using UTF-8) received from the client. The lines have their ‘"\r\n"’ line ending translated to ‘"\n"’. -- Attribute: smtp_state Holds the current state of the channel. This will be either ‘COMMAND’ initially and then ‘DATA’ after the client sends a “DATA” line. -- Attribute: seen_greeting Holds a string containing the greeting sent by the client in its “HELO”. -- Attribute: mailfrom Holds a string containing the address identified in the “MAIL FROM:” line from the client. -- Attribute: rcpttos Holds a list of strings containing the addresses identified in the “RCPT TO:” lines from the client. -- Attribute: received_data Holds a string containing all of the data sent by the client during the DATA state, up to but not including the terminating ‘"\r\n.\r\n"’. -- Attribute: fqdn Holds the fully-qualified domain name of the server as returned by *note socket.getfqdn(): 2381. -- Attribute: peer Holds the name of the client peer as returned by ‘conn.getpeername()’ where ‘conn’ is *note conn: 2adc. The *note SMTPChannel: 601. operates by invoking methods named ‘smtp_<command>’ upon reception of a command line from the client. Built into the base *note SMTPChannel: 601. class are methods for handling the following commands (and responding to them appropriately): Command Action taken ------------------------------------------------------------------------------------- HELO Accepts the greeting from the client and stores it in *note seen_greeting: 2ae0. Sets server to base command mode. EHLO Accepts the greeting from the client and stores it in *note seen_greeting: 2ae0. Sets server to extended command mode. NOOP Takes no action. QUIT Closes the connection cleanly. MAIL Accepts the “MAIL FROM:” syntax and stores the supplied address as *note mailfrom: 2ae1. In extended command mode, accepts the RFC 1870(2) SIZE attribute and responds appropriately based on the value of `data_size_limit'. RCPT Accepts the “RCPT TO:” syntax and stores the supplied addresses in the *note rcpttos: 2ae2. list. RSET Resets the *note mailfrom: 2ae1, *note rcpttos: 2ae2, and *note received_data: 2ae3, but not the greeting. DATA Sets the internal state to ‘DATA’ and stores remaining lines from the client in *note received_data: 2ae3. until the terminator ‘"\r\n.\r\n"’ is received. HELP Returns minimal information on command syntax VRFY Returns code 252 (the server doesn’t know if the address is valid) EXPN Reports that the command is not implemented. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc6531.html (2) https://tools.ietf.org/html/rfc1870.html  File: python.info, Node: telnetlib — Telnet client, Next: uuid — UUID objects according to RFC 4122, Prev: smtpd — SMTP Server, Up: Internet Protocols and Support 5.21.19 ‘telnetlib’ — Telnet client ----------------------------------- `Source code:' Lib/telnetlib.py(1) __________________________________________________________________ The *note telnetlib: 102. module provides a *note Telnet: 597. class that implements the Telnet protocol. See RFC 854(2) for details about the protocol. In addition, it provides symbolic constants for the protocol characters (see below), and for the telnet options. The symbolic names of the telnet options follow the definitions in ‘arpa/telnet.h’, with the leading ‘TELOPT_’ removed. For symbolic names of options which are traditionally not included in ‘arpa/telnet.h’, see the module source itself. The symbolic constants for the telnet commands are: IAC, DONT, DO, WONT, WILL, SE (Subnegotiation End), NOP (No Operation), DM (Data Mark), BRK (Break), IP (Interrupt process), AO (Abort output), AYT (Are You There), EC (Erase Character), EL (Erase Line), GA (Go Ahead), SB (Subnegotiation Begin). -- Class: telnetlib.Telnet (host=None, port=0[, timeout]) *note Telnet: 597. represents a connection to a Telnet server. The instance is initially not connected by default; the *note open(): 2ae8. method must be used to establish a connection. Alternatively, the host name and optional port number can be passed to the constructor too, in which case the connection to the server will be established before the constructor returns. The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). Do not reopen an already connected instance. This class has many ‘read_*()’ methods. Note that some of them raise *note EOFError: c6c. when the end of the connection is read, because they can return an empty string for other reasons. See the individual descriptions below. A *note Telnet: 597. object is a context manager and can be used in a *note with: 6e9. statement. When the ‘with’ block ends, the *note close(): 2ae9. method is called: >>> from telnetlib import Telnet >>> with Telnet('localhost', 23) as tn: ... tn.interact() ... Changed in version 3.6: Context manager support added See also ........ RFC 854(3) - Telnet Protocol Specification Definition of the Telnet protocol. * Menu: * Telnet Objects:: * Telnet Example:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/telnetlib.py (2) https://tools.ietf.org/html/rfc854.html (3) https://tools.ietf.org/html/rfc854.html  File: python.info, Node: Telnet Objects, Next: Telnet Example, Up: telnetlib — Telnet client 5.21.19.1 Telnet Objects ........................ *note Telnet: 597. instances have the following methods: -- Method: Telnet.read_until (expected, timeout=None) Read until a given byte string, `expected', is encountered or until `timeout' seconds have passed. When no match is found, return whatever is available instead, possibly empty bytes. Raise *note EOFError: c6c. if the connection is closed and no cooked data is available. -- Method: Telnet.read_all () Read all data until EOF as bytes; block until connection closed. -- Method: Telnet.read_some () Read at least one byte of cooked data unless EOF is hit. Return ‘b''’ if EOF is hit. Block if no data is immediately available. -- Method: Telnet.read_very_eager () Read everything that can be without blocking in I/O (eager). Raise *note EOFError: c6c. if connection closed and no cooked data available. Return ‘b''’ if no cooked data available otherwise. Do not block unless in the midst of an IAC sequence. -- Method: Telnet.read_eager () Read readily available data. Raise *note EOFError: c6c. if connection closed and no cooked data available. Return ‘b''’ if no cooked data available otherwise. Do not block unless in the midst of an IAC sequence. -- Method: Telnet.read_lazy () Process and return data already in the queues (lazy). Raise *note EOFError: c6c. if connection closed and no data available. Return ‘b''’ if no cooked data available otherwise. Do not block unless in the midst of an IAC sequence. -- Method: Telnet.read_very_lazy () Return any data available in the cooked queue (very lazy). Raise *note EOFError: c6c. if connection closed and no data available. Return ‘b''’ if no cooked data available otherwise. This method never blocks. -- Method: Telnet.read_sb_data () Return the data collected between a SB/SE pair (suboption begin/end). The callback should access these data when it was invoked with a ‘SE’ command. This method never blocks. -- Method: Telnet.open (host, port=0[, timeout]) Connect to a host. The optional second argument is the port number, which defaults to the standard Telnet port (23). The optional `timeout' parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). Do not try to reopen an already connected instance. Raises an *note auditing event: fd1. ‘telnetlib.Telnet.open’ with arguments ‘self’, ‘host’, ‘port’. -- Method: Telnet.msg (msg, *args) Print a debug message when the debug level is ‘>’ 0. If extra arguments are present, they are substituted in the message using the standard string formatting operator. -- Method: Telnet.set_debuglevel (debuglevel) Set the debug level. The higher the value of `debuglevel', the more debug output you get (on ‘sys.stdout’). -- Method: Telnet.close () Close the connection. -- Method: Telnet.get_socket () Return the socket object used internally. -- Method: Telnet.fileno () Return the file descriptor of the socket object used internally. -- Method: Telnet.write (buffer) Write a byte string to the socket, doubling any IAC characters. This can block if the connection is blocked. May raise *note OSError: 1d3. if the connection is closed. Raises an *note auditing event: fd1. ‘telnetlib.Telnet.write’ with arguments ‘self’, ‘buffer’. Changed in version 3.3: This method used to raise *note socket.error: 995, which is now an alias of *note OSError: 1d3. -- Method: Telnet.interact () Interaction function, emulates a very dumb Telnet client. -- Method: Telnet.mt_interact () Multithreaded version of *note interact(): 2af9. -- Method: Telnet.expect (list, timeout=None) Read until one from a list of a regular expressions matches. The first argument is a list of regular expressions, either compiled (*note regex objects: 89c.) or uncompiled (byte strings). The optional second argument is a timeout, in seconds; the default is to block indefinitely. Return a tuple of three items: the index in the list of the first regular expression that matches; the match object returned; and the bytes read up till and including the match. If end of file is found and no bytes were read, raise *note EOFError: c6c. Otherwise, when nothing matches, return ‘(-1, None, data)’ where `data' is the bytes received so far (may be empty bytes if a timeout happened). If a regular expression ends with a greedy match (such as ‘.*’) or if more than one expression can match the same input, the results are non-deterministic, and may depend on the I/O timing. -- Method: Telnet.set_option_negotiation_callback (callback) Each time a telnet option is read on the input flow, this `callback' (if set) is called with the following parameters: callback(telnet socket, command (DO/DONT/WILL/WONT), option). No other action is done afterwards by telnetlib.  File: python.info, Node: Telnet Example, Prev: Telnet Objects, Up: telnetlib — Telnet client 5.21.19.2 Telnet Example ........................ A simple example illustrating typical use: import getpass import telnetlib HOST = "localhost" user = input("Enter your remote account: ") password = getpass.getpass() tn = telnetlib.Telnet(HOST) tn.read_until(b"login: ") tn.write(user.encode('ascii') + b"\n") if password: tn.read_until(b"Password: ") tn.write(password.encode('ascii') + b"\n") tn.write(b"ls\n") tn.write(b"exit\n") print(tn.read_all().decode('ascii'))  File: python.info, Node: uuid — UUID objects according to RFC 4122, Next: socketserver — A framework for network servers, Prev: telnetlib — Telnet client, Up: Internet Protocols and Support 5.21.20 ‘uuid’ — UUID objects according to `RFC 4122' ----------------------------------------------------- `Source code:' Lib/uuid.py(1) __________________________________________________________________ This module provides immutable *note UUID: 260. objects (the *note UUID: 260. class) and the functions *note uuid1(): 413, *note uuid3(): 2b01, *note uuid4(): 2b02, *note uuid5(): 2b03. for generating version 1, 3, 4, and 5 UUIDs as specified in RFC 4122(2). If all you want is a unique ID, you should probably call *note uuid1(): 413. or *note uuid4(): 2b02. Note that *note uuid1(): 413. may compromise privacy since it creates a UUID containing the computer’s network address. *note uuid4(): 2b02. creates a random UUID. Depending on support from the underlying platform, *note uuid1(): 413. may or may not return a “safe” UUID. A safe UUID is one which is generated using synchronization methods that ensure no two processes can obtain the same UUID. All instances of *note UUID: 260. have an ‘is_safe’ attribute which relays any information about the UUID’s safety, using this enumeration: -- Class: uuid.SafeUUID New in version 3.7. -- Attribute: safe The UUID was generated by the platform in a multiprocessing-safe way. -- Attribute: unsafe The UUID was not generated in a multiprocessing-safe way. -- Attribute: unknown The platform does not provide information on whether the UUID was generated safely or not. -- Class: uuid.UUID (hex=None, bytes=None, bytes_le=None, fields=None, int=None, version=None, *, is_safe=SafeUUID.unknown) Create a UUID from either a string of 32 hexadecimal digits, a string of 16 bytes in big-endian order as the `bytes' argument, a string of 16 bytes in little-endian order as the `bytes_le' argument, a tuple of six integers (32-bit `time_low', 16-bit `time_mid', 16-bit `time_hi_version', 8-bit `clock_seq_hi_variant', 8-bit `clock_seq_low', 48-bit `node') as the `fields' argument, or a single 128-bit integer as the `int' argument. When a string of hex digits is given, curly braces, hyphens, and a URN prefix are all optional. For example, these expressions all yield the same UUID: UUID('{12345678-1234-5678-1234-567812345678}') UUID('12345678123456781234567812345678') UUID('urn:uuid:12345678-1234-5678-1234-567812345678') UUID(bytes=b'\x12\x34\x56\x78'*4) UUID(bytes_le=b'\x78\x56\x34\x12\x34\x12\x78\x56' + b'\x12\x34\x56\x78\x12\x34\x56\x78') UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678)) UUID(int=0x12345678123456781234567812345678) Exactly one of `hex', `bytes', `bytes_le', `fields', or `int' must be given. The `version' argument is optional; if given, the resulting UUID will have its variant and version number set according to RFC 4122(3), overriding bits in the given `hex', `bytes', `bytes_le', `fields', or `int'. Comparison of UUID objects are made by way of comparing their *note UUID.int: 2b08. attributes. Comparison with a non-UUID object raises a *note TypeError: 192. ‘str(uuid)’ returns a string in the form ‘12345678-1234-5678-1234-567812345678’ where the 32 hexadecimal digits represent the UUID. *note UUID: 260. instances have these read-only attributes: -- Attribute: UUID.bytes The UUID as a 16-byte string (containing the six integer fields in big-endian byte order). -- Attribute: UUID.bytes_le The UUID as a 16-byte string (with `time_low', `time_mid', and `time_hi_version' in little-endian byte order). -- Attribute: UUID.fields A tuple of the six integer fields of the UUID, which are also available as six individual attributes and two derived attributes: Field Meaning ----------------------------------------------------------------------- ‘time_low’ the first 32 bits of the UUID ‘time_mid’ the next 16 bits of the UUID ‘time_hi_version’ the next 16 bits of the UUID ‘clock_seq_hi_variant’ the next 8 bits of the UUID ‘clock_seq_low’ the next 8 bits of the UUID ‘node’ the last 48 bits of the UUID *note time: 10a. the 60-bit timestamp ‘clock_seq’ the 14-bit sequence number -- Attribute: UUID.hex The UUID as a 32-character hexadecimal string. -- Attribute: UUID.int The UUID as a 128-bit integer. -- Attribute: UUID.urn The UUID as a URN as specified in RFC 4122(4). -- Attribute: UUID.variant The UUID variant, which determines the internal layout of the UUID. This will be one of the constants *note RESERVED_NCS: 2b0f, *note RFC_4122: 2b10, *note RESERVED_MICROSOFT: 2b11, or *note RESERVED_FUTURE: 2b12. -- Attribute: UUID.version The UUID version number (1 through 5, meaningful only when the variant is *note RFC_4122: 2b10.). -- Attribute: UUID.is_safe An enumeration of *note SafeUUID: 2b04. which indicates whether the platform generated the UUID in a multiprocessing-safe way. New in version 3.7. The *note uuid: 124. module defines the following functions: -- Function: uuid.getnode () Get the hardware address as a 48-bit positive integer. The first time this runs, it may launch a separate program, which could be quite slow. If all attempts to obtain the hardware address fail, we choose a random 48-bit number with the multicast bit (least significant bit of the first octet) set to 1 as recommended in RFC 4122(5). “Hardware address” means the MAC address of a network interface. On a machine with multiple network interfaces, universally administered MAC addresses (i.e. where the second least significant bit of the first octet is `unset') will be preferred over locally administered MAC addresses, but with no other ordering guarantees. Changed in version 3.7: Universally administered MAC addresses are preferred over locally administered MAC addresses, since the former are guaranteed to be globally unique, while the latter are not. -- Function: uuid.uuid1 (node=None, clock_seq=None) Generate a UUID from a host ID, sequence number, and the current time. If `node' is not given, *note getnode(): 412. is used to obtain the hardware address. If `clock_seq' is given, it is used as the sequence number; otherwise a random 14-bit sequence number is chosen. -- Function: uuid.uuid3 (namespace, name) Generate a UUID based on the MD5 hash of a namespace identifier (which is a UUID) and a name (which is a string). -- Function: uuid.uuid4 () Generate a random UUID. -- Function: uuid.uuid5 (namespace, name) Generate a UUID based on the SHA-1 hash of a namespace identifier (which is a UUID) and a name (which is a string). The *note uuid: 124. module defines the following namespace identifiers for use with *note uuid3(): 2b01. or *note uuid5(): 2b03. -- Data: uuid.NAMESPACE_DNS When this namespace is specified, the `name' string is a fully-qualified domain name. -- Data: uuid.NAMESPACE_URL When this namespace is specified, the `name' string is a URL. -- Data: uuid.NAMESPACE_OID When this namespace is specified, the `name' string is an ISO OID. -- Data: uuid.NAMESPACE_X500 When this namespace is specified, the `name' string is an X.500 DN in DER or a text output format. The *note uuid: 124. module defines the following constants for the possible values of the ‘variant’ attribute: -- Data: uuid.RESERVED_NCS Reserved for NCS compatibility. -- Data: uuid.RFC_4122 Specifies the UUID layout given in RFC 4122(6). -- Data: uuid.RESERVED_MICROSOFT Reserved for Microsoft compatibility. -- Data: uuid.RESERVED_FUTURE Reserved for future definition. See also ........ RFC 4122(7) - A Universally Unique IDentifier (UUID) URN Namespace This specification defines a Uniform Resource Name namespace for UUIDs, the internal format of UUIDs, and methods of generating UUIDs. * Menu: * Example: Example<13>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/uuid.py (2) https://tools.ietf.org/html/rfc4122.html (3) https://tools.ietf.org/html/rfc4122.html (4) https://tools.ietf.org/html/rfc4122.html (5) https://tools.ietf.org/html/rfc4122.html (6) https://tools.ietf.org/html/rfc4122.html (7) https://tools.ietf.org/html/rfc4122.html  File: python.info, Node: Example<13>, Up: uuid — UUID objects according to RFC 4122 5.21.20.1 Example ................. Here are some examples of typical usage of the *note uuid: 124. module: >>> import uuid >>> # make a UUID based on the host ID and current time >>> uuid.uuid1() UUID('a8098c1a-f86e-11da-bd1a-00112444be1e') >>> # make a UUID using an MD5 hash of a namespace UUID and a name >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org') UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e') >>> # make a random UUID >>> uuid.uuid4() UUID('16fd2706-8baf-433b-82eb-8c7fada847da') >>> # make a UUID using a SHA-1 hash of a namespace UUID and a name >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org') UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d') >>> # make a UUID from a string of hex digits (braces and hyphens ignored) >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}') >>> # convert a UUID to a string of hex digits in standard form >>> str(x) '00010203-0405-0607-0809-0a0b0c0d0e0f' >>> # get the raw 16 bytes of the UUID >>> x.bytes b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f' >>> # make a UUID from a 16-byte string >>> uuid.UUID(bytes=x.bytes) UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')  File: python.info, Node: socketserver — A framework for network servers, Next: http server — HTTP servers, Prev: uuid — UUID objects according to RFC 4122, Up: Internet Protocols and Support 5.21.21 ‘socketserver’ — A framework for network servers -------------------------------------------------------- `Source code:' Lib/socketserver.py(1) __________________________________________________________________ The *note socketserver: f0. module simplifies the task of writing network servers. There are four basic concrete server classes: -- Class: socketserver.TCPServer (server_address, RequestHandlerClass, bind_and_activate=True) This uses the Internet TCP protocol, which provides for continuous streams of data between the client and server. If `bind_and_activate' is true, the constructor automatically attempts to invoke *note server_bind(): 2b1d. and *note server_activate(): 2b1e. The other parameters are passed to the *note BaseServer: a89. base class. -- Class: socketserver.UDPServer (server_address, RequestHandlerClass, bind_and_activate=True) This uses datagrams, which are discrete packets of information that may arrive out of order or be lost while in transit. The parameters are the same as for *note TCPServer: 2b1c. -- Class: socketserver.UnixStreamServer (server_address, RequestHandlerClass, bind_and_activate=True) -- Class: socketserver.UnixDatagramServer (server_address, RequestHandlerClass, bind_and_activate=True) These more infrequently used classes are similar to the TCP and UDP classes, but use Unix domain sockets; they’re not available on non-Unix platforms. The parameters are the same as for *note TCPServer: 2b1c. These four classes process requests `synchronously'; each request must be completed before the next request can be started. This isn’t suitable if each request takes a long time to complete, because it requires a lot of computation, or because it returns a lot of data which the client is slow to process. The solution is to create a separate process or thread to handle each request; the *note ForkingMixIn: 3d5. and *note ThreadingMixIn: 3d6. mix-in classes can be used to support asynchronous behaviour. Creating a server requires several steps. First, you must create a request handler class by subclassing the *note BaseRequestHandler: 2b22. class and overriding its *note handle(): 2b23. method; this method will process incoming requests. Second, you must instantiate one of the server classes, passing it the server’s address and the request handler class. It is recommended to use the server in a *note with: 6e9. statement. Then call the *note handle_request(): 2b24. or *note serve_forever(): a8b. method of the server object to process one or many requests. Finally, call *note server_close(): 2b25. to close the socket (unless you used a ‘with’ statement). When inheriting from *note ThreadingMixIn: 3d6. for threaded connection behavior, you should explicitly declare how you want your threads to behave on an abrupt shutdown. The *note ThreadingMixIn: 3d6. class defines an attribute `daemon_threads', which indicates whether or not the server should wait for thread termination. You should set the flag explicitly if you would like threads to behave autonomously; the default is *note False: 388, meaning that Python will not exit until all threads created by *note ThreadingMixIn: 3d6. have exited. Server classes have the same external methods and attributes, no matter what network protocol they use. * Menu: * Server Creation Notes:: * Server Objects: Server Objects<2>. * Request Handler Objects:: * Examples: Examples<23>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/socketserver.py  File: python.info, Node: Server Creation Notes, Next: Server Objects<2>, Up: socketserver — A framework for network servers 5.21.21.1 Server Creation Notes ............................... There are five classes in an inheritance diagram, four of which represent synchronous servers of four types: +------------+ | BaseServer | +------------+ | v +-----------+ +------------------+ | TCPServer |------->| UnixStreamServer | +-----------+ +------------------+ | v +-----------+ +--------------------+ | UDPServer |------->| UnixDatagramServer | +-----------+ +--------------------+ Note that *note UnixDatagramServer: 2b21. derives from *note UDPServer: 2b1f, not from *note UnixStreamServer: 2b20. — the only difference between an IP and a Unix stream server is the address family, which is simply repeated in both Unix server classes. -- Class: socketserver.ForkingMixIn -- Class: socketserver.ThreadingMixIn Forking and threading versions of each type of server can be created using these mix-in classes. For instance, *note ThreadingUDPServer: 2b27. is created as follows: class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass The mix-in class comes first, since it overrides a method defined in *note UDPServer: 2b1f. Setting the various attributes also changes the behavior of the underlying server mechanism. *note ForkingMixIn: 3d5. and the Forking classes mentioned below are only available on POSIX platforms that support *note fork(): 961. ‘socketserver.ForkingMixIn.server_close()’ waits until all child processes complete, except if ‘socketserver.ForkingMixIn.block_on_close’ attribute is false. ‘socketserver.ThreadingMixIn.server_close()’ waits until all non-daemon threads complete, except if ‘socketserver.ThreadingMixIn.block_on_close’ attribute is false. Use daemonic threads by setting ‘ThreadingMixIn.daemon_threads’ to ‘True’ to not wait until threads complete. Changed in version 3.7: ‘socketserver.ForkingMixIn.server_close()’ and ‘socketserver.ThreadingMixIn.server_close()’ now waits until all child processes and non-daemonic threads complete. Add a new ‘socketserver.ForkingMixIn.block_on_close’ class attribute to opt-in for the pre-3.7 behaviour. -- Class: socketserver.ForkingTCPServer -- Class: socketserver.ForkingUDPServer -- Class: socketserver.ThreadingTCPServer -- Class: socketserver.ThreadingUDPServer These classes are pre-defined using the mix-in classes. To implement a service, you must derive a class from *note BaseRequestHandler: 2b22. and redefine its *note handle(): 2b23. method. You can then run various versions of the service by combining one of the server classes with your request handler class. The request handler class must be different for datagram or stream services. This can be hidden by using the handler subclasses *note StreamRequestHandler: 587. or *note DatagramRequestHandler: 2b2b. Of course, you still have to use your head! For instance, it makes no sense to use a forking server if the service contains state in memory that can be modified by different requests, since the modifications in the child process would never reach the initial state kept in the parent process and passed to each child. In this case, you can use a threading server, but you will probably have to use locks to protect the integrity of the shared data. On the other hand, if you are building an HTTP server where all data is stored externally (for instance, in the file system), a synchronous class will essentially render the service “deaf” while one request is being handled – which may be for a very long time if a client is slow to receive all the data it has requested. Here a threading or forking server is appropriate. In some cases, it may be appropriate to process part of a request synchronously, but to finish processing in a forked child depending on the request data. This can be implemented by using a synchronous server and doing an explicit fork in the request handler class *note handle(): 2b23. method. Another approach to handling multiple simultaneous requests in an environment that supports neither threads nor *note fork(): 961. (or where these are too expensive or inappropriate for the service) is to maintain an explicit table of partially finished requests and to use *note selectors: e6. to decide which request to work on next (or whether to handle a new incoming request). This is particularly important for stream services where each client can potentially be connected for a long time (if threads or subprocesses cannot be used). See *note asyncore: b. for another way to manage this.  File: python.info, Node: Server Objects<2>, Next: Request Handler Objects, Prev: Server Creation Notes, Up: socketserver — A framework for network servers 5.21.21.2 Server Objects ........................ -- Class: socketserver.BaseServer (server_address, RequestHandlerClass) This is the superclass of all Server objects in the module. It defines the interface, given below, but does not implement most of the methods, which is done in subclasses. The two parameters are stored in the respective *note server_address: 2b2d. and *note RequestHandlerClass: 2b2e. attributes. -- Method: fileno () Return an integer file descriptor for the socket on which the server is listening. This function is most commonly passed to *note selectors: e6, to allow monitoring multiple servers in the same process. -- Method: handle_request () Process a single request. This function calls the following methods in order: *note get_request(): 2b30, *note verify_request(): 2b31, and *note process_request(): 2b32. If the user-provided *note handle(): 2b23. method of the handler class raises an exception, the server’s *note handle_error(): 5fd. method will be called. If no request is received within *note timeout: 2b33. seconds, *note handle_timeout(): 2b34. will be called and *note handle_request(): 2b24. will return. -- Method: serve_forever (poll_interval=0.5) Handle requests until an explicit *note shutdown(): 2b35. request. Poll for shutdown every `poll_interval' seconds. Ignores the *note timeout: 2b33. attribute. It also calls *note service_actions(): a8a, which may be used by a subclass or mixin to provide actions specific to a given service. For example, the *note ForkingMixIn: 3d5. class uses *note service_actions(): a8a. to clean up zombie child processes. Changed in version 3.3: Added ‘service_actions’ call to the ‘serve_forever’ method. -- Method: service_actions () This is called in the *note serve_forever(): a8b. loop. This method can be overridden by subclasses or mixin classes to perform actions specific to a given service, such as cleanup actions. New in version 3.3. -- Method: shutdown () Tell the *note serve_forever(): a8b. loop to stop and wait until it does. *note shutdown(): 2b35. must be called while *note serve_forever(): a8b. is running in a different thread otherwise it will deadlock. -- Method: server_close () Clean up the server. May be overridden. -- Attribute: address_family The family of protocols to which the server’s socket belongs. Common examples are *note socket.AF_INET: 229d. and *note socket.AF_UNIX: 22a3. -- Attribute: RequestHandlerClass The user-provided request handler class; an instance of this class is created for each request. -- Attribute: server_address The address on which the server is listening. The format of addresses varies depending on the protocol family; see the documentation for the *note socket: ef. module for details. For Internet protocols, this is a tuple containing a string giving the address, and an integer port number: ‘('127.0.0.1', 80)’, for example. -- Attribute: socket The socket object on which the server will listen for incoming requests. The server classes support the following class variables: -- Attribute: allow_reuse_address Whether the server will allow the reuse of an address. This defaults to *note False: 388, and can be set in subclasses to change the policy. -- Attribute: request_queue_size The size of the request queue. If it takes a long time to process a single request, any requests that arrive while the server is busy are placed into a queue, up to *note request_queue_size: 2b39. requests. Once the queue is full, further requests from clients will get a “Connection denied” error. The default value is usually 5, but this can be overridden by subclasses. -- Attribute: socket_type The type of socket used by the server; *note socket.SOCK_STREAM: c8a. and *note socket.SOCK_DGRAM: c89. are two common values. -- Attribute: timeout Timeout duration, measured in seconds, or *note None: 157. if no timeout is desired. If *note handle_request(): 2b24. receives no incoming requests within the timeout period, the *note handle_timeout(): 2b34. method is called. There are various server methods that can be overridden by subclasses of base server classes like *note TCPServer: 2b1c.; these methods aren’t useful to external users of the server object. -- Method: finish_request (request, client_address) Actually processes the request by instantiating *note RequestHandlerClass: 2b2e. and calling its *note handle(): 2b23. method. -- Method: get_request () Must accept a request from the socket, and return a 2-tuple containing the `new' socket object to be used to communicate with the client, and the client’s address. -- Method: handle_error (request, client_address) This function is called if the *note handle(): 2b23. method of a *note RequestHandlerClass: 2b2e. instance raises an exception. The default action is to print the traceback to standard error and continue handling further requests. Changed in version 3.6: Now only called for exceptions derived from the *note Exception: 1a9. class. -- Method: handle_timeout () This function is called when the *note timeout: 2b33. attribute has been set to a value other than *note None: 157. and the timeout period has passed with no requests being received. The default action for forking servers is to collect the status of any child processes that have exited, while in threading servers this method does nothing. -- Method: process_request (request, client_address) Calls *note finish_request(): 2b3b. to create an instance of the *note RequestHandlerClass: 2b2e. If desired, this function can create a new process or thread to handle the request; the *note ForkingMixIn: 3d5. and *note ThreadingMixIn: 3d6. classes do this. -- Method: server_activate () Called by the server’s constructor to activate the server. The default behavior for a TCP server just invokes *note listen(): 74b. on the server’s socket. May be overridden. -- Method: server_bind () Called by the server’s constructor to bind the socket to the desired address. May be overridden. -- Method: verify_request (request, client_address) Must return a Boolean value; if the value is *note True: 499, the request will be processed, and if it’s *note False: 388, the request will be denied. This function can be overridden to implement access controls for a server. The default implementation always returns *note True: 499. Changed in version 3.6: Support for the *note context manager: 568. protocol was added. Exiting the context manager is equivalent to calling *note server_close(): 2b25.  File: python.info, Node: Request Handler Objects, Next: Examples<23>, Prev: Server Objects<2>, Up: socketserver — A framework for network servers 5.21.21.3 Request Handler Objects ................................. -- Class: socketserver.BaseRequestHandler This is the superclass of all request handler objects. It defines the interface, given below. A concrete request handler subclass must define a new *note handle(): 2b23. method, and can override any of the other methods. A new instance of the subclass is created for each request. -- Method: setup () Called before the *note handle(): 2b23. method to perform any initialization actions required. The default implementation does nothing. -- Method: handle () This function must do all the work required to service a request. The default implementation does nothing. Several instance attributes are available to it; the request is available as ‘self.request’; the client address as ‘self.client_address’; and the server instance as ‘self.server’, in case it needs access to per-server information. The type of ‘self.request’ is different for datagram or stream services. For stream services, ‘self.request’ is a socket object; for datagram services, ‘self.request’ is a pair of string and socket. -- Method: finish () Called after the *note handle(): 2b23. method to perform any clean-up actions required. The default implementation does nothing. If *note setup(): 2b3d. raises an exception, this function will not be called. -- Class: socketserver.StreamRequestHandler -- Class: socketserver.DatagramRequestHandler These *note BaseRequestHandler: 2b22. subclasses override the *note setup(): 2b3d. and *note finish(): 2b3e. methods, and provide ‘self.rfile’ and ‘self.wfile’ attributes. The ‘self.rfile’ and ‘self.wfile’ attributes can be read or written, respectively, to get the request data or return data to the client. The ‘rfile’ attributes of both classes support the *note io.BufferedIOBase: 588. readable interface, and ‘DatagramRequestHandler.wfile’ supports the *note io.BufferedIOBase: 588. writable interface. Changed in version 3.6: ‘StreamRequestHandler.wfile’ also supports the *note io.BufferedIOBase: 588. writable interface.  File: python.info, Node: Examples<23>, Prev: Request Handler Objects, Up: socketserver — A framework for network servers 5.21.21.4 Examples .................. * Menu: * socketserver.TCPServer Example: socketserver TCPServer Example. * socketserver.UDPServer Example: socketserver UDPServer Example. * Asynchronous Mixins::  File: python.info, Node: socketserver TCPServer Example, Next: socketserver UDPServer Example, Up: Examples<23> 5.21.21.5 ‘socketserver.TCPServer’ Example .......................................... This is the server side: import socketserver class MyTCPHandler(socketserver.BaseRequestHandler): """ The request handler class for our server. It is instantiated once per connection to the server, and must override the handle() method to implement communication to the client. """ def handle(self): # self.request is the TCP socket connected to the client self.data = self.request.recv(1024).strip() print("{} wrote:".format(self.client_address[0])) print(self.data) # just send back the same data, but upper-cased self.request.sendall(self.data.upper()) if __name__ == "__main__": HOST, PORT = "localhost", 9999 # Create the server, binding to localhost on port 9999 with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server: # Activate the server; this will keep running until you # interrupt the program with Ctrl-C server.serve_forever() An alternative request handler class that makes use of streams (file-like objects that simplify communication by providing the standard file interface): class MyTCPHandler(socketserver.StreamRequestHandler): def handle(self): # self.rfile is a file-like object created by the handler; # we can now use e.g. readline() instead of raw recv() calls self.data = self.rfile.readline().strip() print("{} wrote:".format(self.client_address[0])) print(self.data) # Likewise, self.wfile is a file-like object used to write back # to the client self.wfile.write(self.data.upper()) The difference is that the ‘readline()’ call in the second handler will call ‘recv()’ multiple times until it encounters a newline character, while the single ‘recv()’ call in the first handler will just return what has been sent from the client in one ‘sendall()’ call. This is the client side: import socket import sys HOST, PORT = "localhost", 9999 data = " ".join(sys.argv[1:]) # Create a socket (SOCK_STREAM means a TCP socket) with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock: # Connect to server and send data sock.connect((HOST, PORT)) sock.sendall(bytes(data + "\n", "utf-8")) # Receive data from the server and shut down received = str(sock.recv(1024), "utf-8") print("Sent: {}".format(data)) print("Received: {}".format(received)) The output of the example should look something like this: Server: $ python TCPServer.py 127.0.0.1 wrote: b'hello world with TCP' 127.0.0.1 wrote: b'python is nice' Client: $ python TCPClient.py hello world with TCP Sent: hello world with TCP Received: HELLO WORLD WITH TCP $ python TCPClient.py python is nice Sent: python is nice Received: PYTHON IS NICE  File: python.info, Node: socketserver UDPServer Example, Next: Asynchronous Mixins, Prev: socketserver TCPServer Example, Up: Examples<23> 5.21.21.6 ‘socketserver.UDPServer’ Example .......................................... This is the server side: import socketserver class MyUDPHandler(socketserver.BaseRequestHandler): """ This class works similar to the TCP handler class, except that self.request consists of a pair of data and client socket, and since there is no connection the client address must be given explicitly when sending data back via sendto(). """ def handle(self): data = self.request[0].strip() socket = self.request[1] print("{} wrote:".format(self.client_address[0])) print(data) socket.sendto(data.upper(), self.client_address) if __name__ == "__main__": HOST, PORT = "localhost", 9999 with socketserver.UDPServer((HOST, PORT), MyUDPHandler) as server: server.serve_forever() This is the client side: import socket import sys HOST, PORT = "localhost", 9999 data = " ".join(sys.argv[1:]) # SOCK_DGRAM is the socket type to use for UDP sockets sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # As you can see, there is no connect() call; UDP has no connections. # Instead, data is directly sent to the recipient via sendto(). sock.sendto(bytes(data + "\n", "utf-8"), (HOST, PORT)) received = str(sock.recv(1024), "utf-8") print("Sent: {}".format(data)) print("Received: {}".format(received)) The output of the example should look exactly like for the TCP server example.  File: python.info, Node: Asynchronous Mixins, Prev: socketserver UDPServer Example, Up: Examples<23> 5.21.21.7 Asynchronous Mixins ............................. To build asynchronous handlers, use the *note ThreadingMixIn: 3d6. and *note ForkingMixIn: 3d5. classes. An example for the *note ThreadingMixIn: 3d6. class: import socket import threading import socketserver class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler): def handle(self): data = str(self.request.recv(1024), 'ascii') cur_thread = threading.current_thread() response = bytes("{}: {}".format(cur_thread.name, data), 'ascii') self.request.sendall(response) class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer): pass def client(ip, port, message): with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock: sock.connect((ip, port)) sock.sendall(bytes(message, 'ascii')) response = str(sock.recv(1024), 'ascii') print("Received: {}".format(response)) if __name__ == "__main__": # Port 0 means to select an arbitrary unused port HOST, PORT = "localhost", 0 server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler) with server: ip, port = server.server_address # Start a thread with the server -- that thread will then start one # more thread for each request server_thread = threading.Thread(target=server.serve_forever) # Exit the server thread when the main thread terminates server_thread.daemon = True server_thread.start() print("Server loop running in thread:", server_thread.name) client(ip, port, "Hello World 1") client(ip, port, "Hello World 2") client(ip, port, "Hello World 3") server.shutdown() The output of the example should look something like this: $ python ThreadedTCPServer.py Server loop running in thread: Thread-1 Received: Thread-2: Hello World 1 Received: Thread-3: Hello World 2 Received: Thread-4: Hello World 3 The *note ForkingMixIn: 3d5. class is used in the same way, except that the server will spawn a new process for each request. Available only on POSIX platforms that support *note fork(): 961.  File: python.info, Node: http server — HTTP servers, Next: http cookies — HTTP state management, Prev: socketserver — A framework for network servers, Up: Internet Protocols and Support 5.21.22 ‘http.server’ — HTTP servers ------------------------------------ `Source code:' Lib/http/server.py(1) __________________________________________________________________ This module defines classes for implementing HTTP servers (Web servers). Warning: *note http.server: 97. is not recommended for production. It only implements basic security checks. One class, *note HTTPServer: 2909, is a *note socketserver.TCPServer: 2b1c. subclass. It creates and listens at the HTTP socket, dispatching the requests to a handler. Code to create and run the server looks like this: def run(server_class=HTTPServer, handler_class=BaseHTTPRequestHandler): server_address = ('', 8000) httpd = server_class(server_address, handler_class) httpd.serve_forever() -- Class: http.server.HTTPServer (server_address, RequestHandlerClass) This class builds on the *note TCPServer: 2b1c. class by storing the server address as instance variables named ‘server_name’ and ‘server_port’. The server is accessible by the handler, typically through the handler’s ‘server’ instance variable. -- Class: http.server.ThreadingHTTPServer (server_address, RequestHandlerClass) This class is identical to HTTPServer but uses threads to handle requests by using the *note ThreadingMixIn: 3d6. This is useful to handle web browsers pre-opening sockets, on which *note HTTPServer: 2909. would wait indefinitely. New in version 3.7. The *note HTTPServer: 2909. and *note ThreadingHTTPServer: 396. must be given a `RequestHandlerClass' on instantiation, of which this module provides three different variants: -- Class: http.server.BaseHTTPRequestHandler (request, client_address, server) This class is used to handle the HTTP requests that arrive at the server. By itself, it cannot respond to any actual HTTP requests; it must be subclassed to handle each request method (e.g. GET or POST). *note BaseHTTPRequestHandler: a0e. provides a number of class and instance variables, and methods for use by subclasses. The handler will parse the request and the headers, then call a method specific to the request type. The method name is constructed from the request. For example, for the request method ‘SPAM’, the ‘do_SPAM()’ method will be called with no arguments. All of the relevant information is stored in instance variables of the handler. Subclasses should not need to override or extend the *note __init__(): d5e. method. *note BaseHTTPRequestHandler: a0e. has the following instance variables: -- Attribute: client_address Contains a tuple of the form ‘(host, port)’ referring to the client’s address. -- Attribute: server Contains the server instance. -- Attribute: close_connection Boolean that should be set before *note handle_one_request(): 2b48. returns, indicating if another request may be expected, or if the connection should be shut down. -- Attribute: requestline Contains the string representation of the HTTP request line. The terminating CRLF is stripped. This attribute should be set by *note handle_one_request(): 2b48. If no valid request line was processed, it should be set to the empty string. -- Attribute: command Contains the command (request type). For example, ‘'GET'’. -- Attribute: path Contains the request path. -- Attribute: request_version Contains the version string from the request. For example, ‘'HTTP/1.0'’. -- Attribute: headers Holds an instance of the class specified by the *note MessageClass: 2b4d. class variable. This instance parses and manages the headers in the HTTP request. The *note parse_headers(): 29ed. function from *note http.client: 94. is used to parse the headers and it requires that the HTTP request provide a valid RFC 2822(2) style header. -- Attribute: rfile An *note io.BufferedIOBase: 588. input stream, ready to read from the start of the optional input data. -- Attribute: wfile Contains the output stream for writing a response back to the client. Proper adherence to the HTTP protocol must be used when writing to this stream in order to achieve successful interoperation with HTTP clients. Changed in version 3.6: This is an *note io.BufferedIOBase: 588. stream. *note BaseHTTPRequestHandler: a0e. has the following attributes: -- Attribute: server_version Specifies the server software version. You may want to override this. The format is multiple whitespace-separated strings, where each string is of the form name[/version]. For example, ‘'BaseHTTP/0.2'’. -- Attribute: sys_version Contains the Python system version, in a form usable by the *note version_string: 2b52. method and the *note server_version: 2b50. class variable. For example, ‘'Python/1.4'’. -- Attribute: error_message_format Specifies a format string that should be used by *note send_error(): 85c. method for building an error response to the client. The string is filled by default with variables from *note responses: 29d9. based on the status code that passed to *note send_error(): 85c. -- Attribute: error_content_type Specifies the Content-Type HTTP header of error responses sent to the client. The default value is ‘'text/html'’. -- Attribute: protocol_version This specifies the HTTP protocol version used in responses. If set to ‘'HTTP/1.1'’, the server will permit HTTP persistent connections; however, your server `must' then include an accurate ‘Content-Length’ header (using *note send_header(): 2b56.) in all of its responses to clients. For backwards compatibility, the setting defaults to ‘'HTTP/1.0'’. -- Attribute: MessageClass Specifies an *note email.message.Message: 541.-like class to parse HTTP headers. Typically, this is not overridden, and it defaults to ‘http.client.HTTPMessage’. -- Attribute: responses This attribute contains a mapping of error code integers to two-element tuples containing a short and long message. For example, ‘{code: (shortmessage, longmessage)}’. The `shortmessage' is usually used as the `message' key in an error response, and `longmessage' as the `explain' key. It is used by *note send_response_only(): 2b57. and *note send_error(): 85c. methods. A *note BaseHTTPRequestHandler: a0e. instance has the following methods: -- Method: handle () Calls *note handle_one_request(): 2b48. once (or, if persistent connections are enabled, multiple times) to handle incoming HTTP requests. You should never need to override it; instead, implement appropriate ‘do_*()’ methods. -- Method: handle_one_request () This method will parse and dispatch the request to the appropriate ‘do_*()’ method. You should never need to override it. -- Method: handle_expect_100 () When a HTTP/1.1 compliant server receives an ‘Expect: 100-continue’ request header it responds back with a ‘100 Continue’ followed by ‘200 OK’ headers. This method can be overridden to raise an error if the server does not want the client to continue. For e.g. server can chose to send ‘417 Expectation Failed’ as a response header and ‘return False’. New in version 3.2. -- Method: send_error (code, message=None, explain=None) Sends and logs a complete error reply to the client. The numeric `code' specifies the HTTP error code, with `message' as an optional, short, human readable description of the error. The `explain' argument can be used to provide more detailed information about the error; it will be formatted using the *note error_message_format: 2b53. attribute and emitted, after a complete set of headers, as the response body. The *note responses: 29d9. attribute holds the default values for `message' and `explain' that will be used if no value is provided; for unknown codes the default value for both is the string ‘???’. The body will be empty if the method is HEAD or the response code is one of the following: ‘1xx’, ‘204 No Content’, ‘205 Reset Content’, ‘304 Not Modified’. Changed in version 3.4: The error response includes a Content-Length header. Added the `explain' argument. -- Method: send_response (code, message=None) Adds a response header to the headers buffer and logs the accepted request. The HTTP response line is written to the internal buffer, followed by `Server' and `Date' headers. The values for these two headers are picked up from the *note version_string(): 2b52. and *note date_time_string(): 2b5b. methods, respectively. If the server does not intend to send any other headers using the *note send_header(): 2b56. method, then *note send_response(): 2b5a. should be followed by an *note end_headers(): a0f. call. Changed in version 3.3: Headers are stored to an internal buffer and *note end_headers(): a0f. needs to be called explicitly. -- Method: send_header (keyword, value) Adds the HTTP header to an internal buffer which will be written to the output stream when either *note end_headers(): a0f. or *note flush_headers(): a10. is invoked. `keyword' should specify the header keyword, with `value' specifying its value. Note that, after the send_header calls are done, *note end_headers(): a0f. MUST BE called in order to complete the operation. Changed in version 3.2: Headers are stored in an internal buffer. -- Method: send_response_only (code, message=None) Sends the response header only, used for the purposes when ‘100 Continue’ response is sent by the server to the client. The headers not buffered and sent directly the output stream.If the `message' is not specified, the HTTP message corresponding the response `code' is sent. New in version 3.2. -- Method: end_headers () Adds a blank line (indicating the end of the HTTP headers in the response) to the headers buffer and calls *note flush_headers(): a10. Changed in version 3.2: The buffered headers are written to the output stream. -- Method: flush_headers () Finally send the headers to the output stream and flush the internal headers buffer. New in version 3.3. -- Method: log_request (code='-', size='-') Logs an accepted (successful) request. `code' should specify the numeric HTTP code associated with the response. If a size of the response is available, then it should be passed as the `size' parameter. -- Method: log_error (...) Logs an error when a request cannot be fulfilled. By default, it passes the message to *note log_message(): 2b5e, so it takes the same arguments (`format' and additional values). -- Method: log_message (format, ...) Logs an arbitrary message to ‘sys.stderr’. This is typically overridden to create custom error logging mechanisms. The `format' argument is a standard printf-style format string, where the additional arguments to *note log_message(): 2b5e. are applied as inputs to the formatting. The client ip address and current date and time are prefixed to every message logged. -- Method: version_string () Returns the server software’s version string. This is a combination of the *note server_version: 2b50. and *note sys_version: 2b51. attributes. -- Method: date_time_string (timestamp=None) Returns the date and time given by `timestamp' (which must be ‘None’ or in the format returned by *note time.time(): 31d.), formatted for a message header. If `timestamp' is omitted, it uses the current date and time. The result looks like ‘'Sun, 06 Nov 1994 08:49:37 GMT'’. -- Method: log_date_time_string () Returns the current date and time, formatted for logging. -- Method: address_string () Returns the client address. Changed in version 3.3: Previously, a name lookup was performed. To avoid name resolution delays, it now always returns the IP address. -- Class: http.server.SimpleHTTPRequestHandler (request, client_address, server, directory=None) This class serves files from the current directory and below, directly mapping the directory structure to HTTP requests. A lot of the work, such as parsing the request, is done by the base class *note BaseHTTPRequestHandler: a0e. This class implements the *note do_GET(): 2b61. and *note do_HEAD(): 2b62. functions. The following are defined as class-level attributes of *note SimpleHTTPRequestHandler: 395.: -- Attribute: server_version This will be ‘"SimpleHTTP/" + __version__’, where ‘__version__’ is defined at the module level. -- Attribute: extensions_map A dictionary mapping suffixes into MIME types. The default is signified by an empty string, and is considered to be ‘application/octet-stream’. The mapping is used case-insensitively, and so should contain only lower-cased keys. -- Attribute: directory If not specified, the directory to serve is the current working directory. The *note SimpleHTTPRequestHandler: 395. class defines the following methods: -- Method: do_HEAD () This method serves the ‘'HEAD'’ request type: it sends the headers it would send for the equivalent ‘GET’ request. See the *note do_GET(): 2b61. method for a more complete explanation of the possible headers. -- Method: do_GET () The request is mapped to a local file by interpreting the request as a path relative to the current working directory. If the request was mapped to a directory, the directory is checked for a file named ‘index.html’ or ‘index.htm’ (in that order). If found, the file’s contents are returned; otherwise a directory listing is generated by calling the ‘list_directory()’ method. This method uses *note os.listdir(): a41. to scan the directory, and returns a ‘404’ error response if the *note listdir(): a41. fails. If the request was mapped to a file, it is opened. Any *note OSError: 1d3. exception in opening the requested file is mapped to a ‘404’, ‘'File not found'’ error. If there was a ‘'If-Modified-Since'’ header in the request, and the file was not modified after this time, a ‘304’, ‘'Not Modified'’ response is sent. Otherwise, the content type is guessed by calling the ‘guess_type()’ method, which in turn uses the `extensions_map' variable, and the file contents are returned. A ‘'Content-type:'’ header with the guessed content type is output, followed by a ‘'Content-Length:'’ header with the file’s size and a ‘'Last-Modified:'’ header with the file’s modification time. Then follows a blank line signifying the end of the headers, and then the contents of the file are output. If the file’s MIME type starts with ‘text/’ the file is opened in text mode; otherwise binary mode is used. For example usage, see the implementation of the *note test(): 105. function invocation in the *note http.server: 97. module. Changed in version 3.7: Support of the ‘'If-Modified-Since'’ header. The *note SimpleHTTPRequestHandler: 395. class can be used in the following manner in order to create a very basic webserver serving files relative to the current directory: import http.server import socketserver PORT = 8000 Handler = http.server.SimpleHTTPRequestHandler with socketserver.TCPServer(("", PORT), Handler) as httpd: print("serving at port", PORT) httpd.serve_forever() *note http.server: 97. can also be invoked directly using the *note -m: 337. switch of the interpreter with a ‘port number’ argument. Similar to the previous example, this serves files relative to the current directory: python -m http.server 8000 By default, server binds itself to all interfaces. The option ‘-b/--bind’ specifies a specific address to which it should bind. Both IPv4 and IPv6 addresses are supported. For example, the following command causes the server to bind to localhost only: python -m http.server 8000 --bind 127.0.0.1 New in version 3.4: ‘--bind’ argument was introduced. New in version 3.8: ‘--bind’ argument enhanced to support IPv6 By default, server uses the current directory. The option ‘-d/--directory’ specifies a directory to which it should serve the files. For example, the following command uses a specific directory: python -m http.server --directory /tmp/ New in version 3.7: ‘--directory’ specify alternate directory -- Class: http.server.CGIHTTPRequestHandler (request, client_address, server) This class is used to serve either files or output of CGI scripts from the current directory and below. Note that mapping HTTP hierarchic structure to local directory structure is exactly as in *note SimpleHTTPRequestHandler: 395. Note: CGI scripts run by the *note CGIHTTPRequestHandler: 2b66. class cannot execute redirects (HTTP code 302), because code 200 (script output follows) is sent prior to execution of the CGI script. This pre-empts the status code. The class will however, run the CGI script, instead of serving it as a file, if it guesses it to be a CGI script. Only directory-based CGI are used — the other common server configuration is to treat special extensions as denoting CGI scripts. The ‘do_GET()’ and ‘do_HEAD()’ functions are modified to run CGI scripts and serve the output, instead of serving files, if the request leads to somewhere below the ‘cgi_directories’ path. The *note CGIHTTPRequestHandler: 2b66. defines the following data member: -- Attribute: cgi_directories This defaults to ‘['/cgi-bin', '/htbin']’ and describes directories to treat as containing CGI scripts. The *note CGIHTTPRequestHandler: 2b66. defines the following method: -- Method: do_POST () This method serves the ‘'POST'’ request type, only allowed for CGI scripts. Error 501, “Can only POST to CGI scripts”, is output when trying to POST to a non-CGI url. Note that CGI scripts will be run with UID of user nobody, for security reasons. Problems with the CGI script will be translated to error 403. *note CGIHTTPRequestHandler: 2b66. can be enabled in the command line by passing the ‘--cgi’ option: python -m http.server --cgi 8000 ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/http/server.py (2) https://tools.ietf.org/html/rfc2822.html  File: python.info, Node: http cookies — HTTP state management, Next: http cookiejar — Cookie handling for HTTP clients, Prev: http server — HTTP servers, Up: Internet Protocols and Support 5.21.23 ‘http.cookies’ — HTTP state management ---------------------------------------------- `Source code:' Lib/http/cookies.py(1) __________________________________________________________________ The *note http.cookies: 96. module defines classes for abstracting the concept of cookies, an HTTP state management mechanism. It supports both simple string-only cookies, and provides an abstraction for having any serializable data-type as cookie value. The module formerly strictly applied the parsing rules described in the RFC 2109(2) and RFC 2068(3) specifications. It has since been discovered that MSIE 3.0x doesn’t follow the character rules outlined in those specs and also many current day browsers and servers have relaxed parsing rules when comes to Cookie handling. As a result, the parsing rules used are a bit less strict. The character set, *note string.ascii_letters: c5c, *note string.digits: 13cd. and ‘!#$%&'*+-.^_`|~:’ denote the set of valid characters allowed by this module in Cookie name (as *note key: 48d.). Changed in version 3.3: Allowed ‘:’ as a valid Cookie name character. Note: On encountering an invalid cookie, *note CookieError: 2b6b. is raised, so if your cookie data comes from a browser you should always prepare for invalid data and catch *note CookieError: 2b6b. on parsing. -- Exception: http.cookies.CookieError Exception failing because of RFC 2109(4) invalidity: incorrect attributes, incorrect ‘Set-Cookie’ header, etc. -- Class: http.cookies.BaseCookie ([input]) This class is a dictionary-like object whose keys are strings and whose values are *note Morsel: 490. instances. Note that upon setting a key to a value, the value is first converted to a *note Morsel: 490. containing the key and the value. If `input' is given, it is passed to the *note load(): 2b6d. method. -- Class: http.cookies.SimpleCookie ([input]) This class derives from *note BaseCookie: 2b6c. and overrides ‘value_decode()’ and ‘value_encode()’. SimpleCookie supports strings as cookie values. When setting the value, SimpleCookie calls the builtin *note str(): 330. to convert the value to a string. Values received from HTTP are kept as strings. See also ........ Module *note http.cookiejar: 95. HTTP cookie handling for web `clients'. The *note http.cookiejar: 95. and *note http.cookies: 96. modules do not depend on each other. RFC 2109(5) - HTTP State Management Mechanism This is the state management specification implemented by this module. * Menu: * Cookie Objects:: * Morsel Objects:: * Example: Example<14>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/http/cookies.py (2) https://tools.ietf.org/html/rfc2109.html (3) https://tools.ietf.org/html/rfc2068.html (4) https://tools.ietf.org/html/rfc2109.html (5) https://tools.ietf.org/html/rfc2109.html  File: python.info, Node: Cookie Objects, Next: Morsel Objects, Up: http cookies — HTTP state management 5.21.23.1 Cookie Objects ........................ -- Method: BaseCookie.value_decode (val) Return a tuple ‘(real_value, coded_value)’ from a string representation. ‘real_value’ can be any type. This method does no decoding in *note BaseCookie: 2b6c. — it exists so it can be overridden. -- Method: BaseCookie.value_encode (val) Return a tuple ‘(real_value, coded_value)’. `val' can be any type, but ‘coded_value’ will always be converted to a string. This method does no encoding in *note BaseCookie: 2b6c. — it exists so it can be overridden. In general, it should be the case that *note value_encode(): 2b72. and *note value_decode(): 2b71. are inverses on the range of `value_decode'. -- Method: BaseCookie.output (attrs=None, header='Set-Cookie:', sep='\r\n') Return a string representation suitable to be sent as HTTP headers. `attrs' and `header' are sent to each *note Morsel: 490.’s *note output(): 2b73. method. `sep' is used to join the headers together, and is by default the combination ‘'\r\n'’ (CRLF). -- Method: BaseCookie.js_output (attrs=None) Return an embeddable JavaScript snippet, which, if run on a browser which supports JavaScript, will act the same as if the HTTP headers was sent. The meaning for `attrs' is the same as in *note output(): 2b73. -- Method: BaseCookie.load (rawdata) If `rawdata' is a string, parse it as an ‘HTTP_COOKIE’ and add the values found there as *note Morsel: 490.s. If it is a dictionary, it is equivalent to: for k, v in rawdata.items(): cookie[k] = v  File: python.info, Node: Morsel Objects, Next: Example<14>, Prev: Cookie Objects, Up: http cookies — HTTP state management 5.21.23.2 Morsel Objects ........................ -- Class: http.cookies.Morsel Abstract a key/value pair, which has some RFC 2109(1) attributes. Morsels are dictionary-like objects, whose set of keys is constant — the valid RFC 2109(2) attributes, which are * ‘expires’ * ‘path’ * ‘comment’ * ‘domain’ * ‘max-age’ * ‘secure’ * ‘version’ * ‘httponly’ * ‘samesite’ The attribute ‘httponly’ specifies that the cookie is only transferred in HTTP requests, and is not accessible through JavaScript. This is intended to mitigate some forms of cross-site scripting. The attribute ‘samesite’ specifies that the browser is not allowed to send the cookie along with cross-site requests. This helps to mitigate CSRF attacks. Valid values for this attribute are “Strict” and “Lax”. The keys are case-insensitive and their default value is ‘''’. Changed in version 3.5: ‘__eq__()’ now takes *note key: 48d. and *note value: 48e. into account. Changed in version 3.7: Attributes *note key: 48d, *note value: 48e. and *note coded_value: 48f. are read-only. Use *note set(): 491. for setting them. Changed in version 3.8: Added support for the ‘samesite’ attribute. -- Attribute: Morsel.value The value of the cookie. -- Attribute: Morsel.coded_value The encoded value of the cookie — this is what should be sent. -- Attribute: Morsel.key The name of the cookie. -- Method: Morsel.set (key, value, coded_value) Set the `key', `value' and `coded_value' attributes. -- Method: Morsel.isReservedKey (K) Whether `K' is a member of the set of keys of a *note Morsel: 490. -- Method: Morsel.output (attrs=None, header='Set-Cookie:') Return a string representation of the Morsel, suitable to be sent as an HTTP header. By default, all the attributes are included, unless `attrs' is given, in which case it should be a list of attributes to use. `header' is by default ‘"Set-Cookie:"’. -- Method: Morsel.js_output (attrs=None) Return an embeddable JavaScript snippet, which, if run on a browser which supports JavaScript, will act the same as if the HTTP header was sent. The meaning for `attrs' is the same as in *note output(): 2b78. -- Method: Morsel.OutputString (attrs=None) Return a string representing the Morsel, without any surrounding HTTP or JavaScript. The meaning for `attrs' is the same as in *note output(): 2b78. -- Method: Morsel.update (values) Update the values in the Morsel dictionary with the values in the dictionary `values'. Raise an error if any of the keys in the `values' dict is not a valid RFC 2109(3) attribute. Changed in version 3.5: an error is raised for invalid keys. -- Method: Morsel.copy (value) Return a shallow copy of the Morsel object. Changed in version 3.5: return a Morsel object instead of a dict. -- Method: Morsel.setdefault (key, value=None) Raise an error if key is not a valid RFC 2109(4) attribute, otherwise behave the same as *note dict.setdefault(): 9bf. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2109.html (2) https://tools.ietf.org/html/rfc2109.html (3) https://tools.ietf.org/html/rfc2109.html (4) https://tools.ietf.org/html/rfc2109.html  File: python.info, Node: Example<14>, Prev: Morsel Objects, Up: http cookies — HTTP state management 5.21.23.3 Example ................. The following example demonstrates how to use the *note http.cookies: 96. module. >>> from http import cookies >>> C = cookies.SimpleCookie() >>> C["fig"] = "newton" >>> C["sugar"] = "wafer" >>> print(C) # generate HTTP headers Set-Cookie: fig=newton Set-Cookie: sugar=wafer >>> print(C.output()) # same thing Set-Cookie: fig=newton Set-Cookie: sugar=wafer >>> C = cookies.SimpleCookie() >>> C["rocky"] = "road" >>> C["rocky"]["path"] = "/cookie" >>> print(C.output(header="Cookie:")) Cookie: rocky=road; Path=/cookie >>> print(C.output(attrs=[], header="Cookie:")) Cookie: rocky=road >>> C = cookies.SimpleCookie() >>> C.load("chips=ahoy; vienna=finger") # load from a string (HTTP header) >>> print(C) Set-Cookie: chips=ahoy Set-Cookie: vienna=finger >>> C = cookies.SimpleCookie() >>> C.load('keebler="E=everybody; L=\\"Loves\\"; fudge=\\012;";') >>> print(C) Set-Cookie: keebler="E=everybody; L=\"Loves\"; fudge=\012;" >>> C = cookies.SimpleCookie() >>> C["oreo"] = "doublestuff" >>> C["oreo"]["path"] = "/" >>> print(C) Set-Cookie: oreo=doublestuff; Path=/ >>> C = cookies.SimpleCookie() >>> C["twix"] = "none for you" >>> C["twix"].value 'none for you' >>> C = cookies.SimpleCookie() >>> C["number"] = 7 # equivalent to C["number"] = str(7) >>> C["string"] = "seven" >>> C["number"].value '7' >>> C["string"].value 'seven' >>> print(C) Set-Cookie: number=7 Set-Cookie: string=seven  File: python.info, Node: http cookiejar — Cookie handling for HTTP clients, Next: xmlrpc — XMLRPC server and client modules, Prev: http cookies — HTTP state management, Up: Internet Protocols and Support 5.21.24 ‘http.cookiejar’ — Cookie handling for HTTP clients ----------------------------------------------------------- `Source code:' Lib/http/cookiejar.py(1) __________________________________________________________________ The *note http.cookiejar: 95. module defines classes for automatic handling of HTTP cookies. It is useful for accessing web sites that require small pieces of data – `cookies' – to be set on the client machine by an HTTP response from a web server, and then returned to the server in later HTTP requests. Both the regular Netscape cookie protocol and the protocol defined by RFC 2965(2) are handled. RFC 2965 handling is switched off by default. RFC 2109(3) cookies are parsed as Netscape cookies and subsequently treated either as Netscape or RFC 2965 cookies according to the ‘policy’ in effect. Note that the great majority of cookies on the Internet are Netscape cookies. *note http.cookiejar: 95. attempts to follow the de-facto Netscape cookie protocol (which differs substantially from that set out in the original Netscape specification), including taking note of the ‘max-age’ and ‘port’ cookie-attributes introduced with RFC 2965. Note: The various named parameters found in ‘Set-Cookie’ and ‘Set-Cookie2’ headers (eg. ‘domain’ and ‘expires’) are conventionally referred to as `attributes'. To distinguish them from Python attributes, the documentation for this module uses the term `cookie-attribute' instead. The module defines the following exception: -- Exception: http.cookiejar.LoadError Instances of *note FileCookieJar: 2b81. raise this exception on failure to load cookies from a file. *note LoadError: 2b80. is a subclass of *note OSError: 1d3. Changed in version 3.3: LoadError was made a subclass of *note OSError: 1d3. instead of *note IOError: 992. The following classes are provided: -- Class: http.cookiejar.CookieJar (policy=None) `policy' is an object implementing the *note CookiePolicy: 2b82. interface. The *note CookieJar: 297c. class stores HTTP cookies. It extracts cookies from HTTP requests, and returns them in HTTP responses. *note CookieJar: 297c. instances automatically expire contained cookies when necessary. Subclasses are also responsible for storing and retrieving cookies from a file or database. -- Class: http.cookiejar.FileCookieJar (filename, delayload=None, policy=None) `policy' is an object implementing the *note CookiePolicy: 2b82. interface. For the other arguments, see the documentation for the corresponding attributes. A *note CookieJar: 297c. which can load cookies from, and perhaps save cookies to, a file on disk. Cookies are `NOT' loaded from the named file until either the *note load(): 2b83. or *note revert(): 2b84. method is called. Subclasses of this class are documented in section *note FileCookieJar subclasses and co-operation with web browsers: 2b85. Changed in version 3.8: The filename parameter supports a *note path-like object: 36a. -- Class: http.cookiejar.CookiePolicy This class is responsible for deciding whether each cookie should be accepted from / returned to the server. -- Class: http.cookiejar.DefaultCookiePolicy (blocked_domains=None, allowed_domains=None, netscape=True, rfc2965=False, rfc2109_as_netscape=None, hide_cookie2=False, strict_domain=False, strict_rfc2965_unverifiable=True, strict_ns_unverifiable=False, strict_ns_domain=DefaultCookiePolicy.DomainLiberal, strict_ns_set_initial_dollar=False, strict_ns_set_path=False, secure_protocols=("https", "wss")) Constructor arguments should be passed as keyword arguments only. `blocked_domains' is a sequence of domain names that we never accept cookies from, nor return cookies to. `allowed_domains' if not *note None: 157, this is a sequence of the only domains for which we accept and return cookies. `secure_protocols' is a sequence of protocols for which secure cookies can be added to. By default `https' and `wss' (secure websocket) are considered secure protocols. For all other arguments, see the documentation for *note CookiePolicy: 2b82. and *note DefaultCookiePolicy: 2b86. objects. *note DefaultCookiePolicy: 2b86. implements the standard accept / reject rules for Netscape and RFC 2965(4) cookies. By default, RFC 2109(5) cookies (ie. cookies received in a ‘Set-Cookie’ header with a version cookie-attribute of 1) are treated according to the RFC 2965 rules. However, if RFC 2965 handling is turned off or *note rfc2109_as_netscape: 2b87. is ‘True’, RFC 2109 cookies are ‘downgraded’ by the *note CookieJar: 297c. instance to Netscape cookies, by setting the ‘version’ attribute of the *note Cookie: 2b88. instance to 0. *note DefaultCookiePolicy: 2b86. also provides some parameters to allow some fine-tuning of policy. -- Class: http.cookiejar.Cookie This class represents Netscape, RFC 2109(6) and RFC 2965(7) cookies. It is not expected that users of *note http.cookiejar: 95. construct their own *note Cookie: 2b88. instances. Instead, if necessary, call ‘make_cookies()’ on a *note CookieJar: 297c. instance. See also ........ Module *note urllib.request: 120. URL opening with automatic cookie handling. Module *note http.cookies: 96. HTTP cookie classes, principally useful for server-side code. The *note http.cookiejar: 95. and *note http.cookies: 96. modules do not depend on each other. ‘https://curl.haxx.se/rfc/cookie_spec.html’ The specification of the original Netscape cookie protocol. Though this is still the dominant protocol, the ‘Netscape cookie protocol’ implemented by all the major browsers (and *note http.cookiejar: 95.) only bears a passing resemblance to the one sketched out in ‘cookie_spec.html’. RFC 2109(8) - HTTP State Management Mechanism Obsoleted by RFC 2965(9). Uses ‘Set-Cookie’ with version=1. RFC 2965(10) - HTTP State Management Mechanism The Netscape protocol with the bugs fixed. Uses ‘Set-Cookie2’ in place of ‘Set-Cookie’. Not widely used. ‘http://kristol.org/cookie/errata.html’ Unfinished errata to RFC 2965(11). RFC 2964(12) - Use of HTTP State Management * Menu: * CookieJar and FileCookieJar Objects:: * FileCookieJar subclasses and co-operation with web browsers:: * CookiePolicy Objects:: * DefaultCookiePolicy Objects:: * Cookie Objects: Cookie Objects<2>. * Examples: Examples<24>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/http/cookiejar.py (2) https://tools.ietf.org/html/rfc2965.html (3) https://tools.ietf.org/html/rfc2109.html (4) https://tools.ietf.org/html/rfc2965.html (5) https://tools.ietf.org/html/rfc2109.html (6) https://tools.ietf.org/html/rfc2109.html (7) https://tools.ietf.org/html/rfc2965.html (8) https://tools.ietf.org/html/rfc2109.html (9) https://tools.ietf.org/html/rfc2965.html (10) https://tools.ietf.org/html/rfc2965.html (11) https://tools.ietf.org/html/rfc2965.html (12) https://tools.ietf.org/html/rfc2964.html  File: python.info, Node: CookieJar and FileCookieJar Objects, Next: FileCookieJar subclasses and co-operation with web browsers, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.1 CookieJar and FileCookieJar Objects ............................................. *note CookieJar: 297c. objects support the *note iterator: 112e. protocol for iterating over contained *note Cookie: 2b88. objects. *note CookieJar: 297c. has the following methods: -- Method: CookieJar.add_cookie_header (request) Add correct ‘Cookie’ header to `request'. If policy allows (ie. the ‘rfc2965’ and ‘hide_cookie2’ attributes of the *note CookieJar: 297c.’s *note CookiePolicy: 2b82. instance are true and false respectively), the ‘Cookie2’ header is also added when appropriate. The `request' object (usually a *note urllib.request.Request: 8f6. instance) must support the methods ‘get_full_url()’, ‘get_host()’, ‘get_type()’, ‘unverifiable()’, ‘has_header()’, ‘get_header()’, ‘header_items()’, ‘add_unredirected_header()’ and ‘origin_req_host’ attribute as documented by *note urllib.request: 120. Changed in version 3.3: `request' object needs ‘origin_req_host’ attribute. Dependency on a deprecated method ‘get_origin_req_host()’ has been removed. -- Method: CookieJar.extract_cookies (response, request) Extract cookies from HTTP `response' and store them in the *note CookieJar: 297c, where allowed by policy. The *note CookieJar: 297c. will look for allowable ‘Set-Cookie’ and ‘Set-Cookie2’ headers in the `response' argument, and store cookies as appropriate (subject to the *note CookiePolicy.set_ok(): 2b8d. method’s approval). The `response' object (usually the result of a call to *note urllib.request.urlopen(): 78c, or similar) should support an ‘info()’ method, which returns an *note email.message.Message: 541. instance. The `request' object (usually a *note urllib.request.Request: 8f6. instance) must support the methods ‘get_full_url()’, ‘get_host()’, ‘unverifiable()’, and ‘origin_req_host’ attribute, as documented by *note urllib.request: 120. The request is used to set default values for cookie-attributes as well as for checking that the cookie is allowed to be set. Changed in version 3.3: `request' object needs ‘origin_req_host’ attribute. Dependency on a deprecated method ‘get_origin_req_host()’ has been removed. -- Method: CookieJar.set_policy (policy) Set the *note CookiePolicy: 2b82. instance to be used. -- Method: CookieJar.make_cookies (response, request) Return sequence of *note Cookie: 2b88. objects extracted from `response' object. See the documentation for *note extract_cookies(): 2b8c. for the interfaces required of the `response' and `request' arguments. -- Method: CookieJar.set_cookie_if_ok (cookie, request) Set a *note Cookie: 2b88. if policy says it’s OK to do so. -- Method: CookieJar.set_cookie (cookie) Set a *note Cookie: 2b88, without checking with policy to see whether or not it should be set. -- Method: CookieJar.clear ([domain[, path[, name]]]) Clear some cookies. If invoked without arguments, clear all cookies. If given a single argument, only cookies belonging to that `domain' will be removed. If given two arguments, cookies belonging to the specified `domain' and URL `path' are removed. If given three arguments, then the cookie with the specified `domain', `path' and `name' is removed. Raises *note KeyError: 2c7. if no matching cookie exists. -- Method: CookieJar.clear_session_cookies () Discard all session cookies. Discards all contained cookies that have a true ‘discard’ attribute (usually because they had either no ‘max-age’ or ‘expires’ cookie-attribute, or an explicit ‘discard’ cookie-attribute). For interactive browsers, the end of a session usually corresponds to closing the browser window. Note that the ‘save()’ method won’t save session cookies anyway, unless you ask otherwise by passing a true `ignore_discard' argument. *note FileCookieJar: 2b81. implements the following additional methods: -- Method: FileCookieJar.save (filename=None, ignore_discard=False, ignore_expires=False) Save cookies to a file. This base class raises *note NotImplementedError: 60e. Subclasses may leave this method unimplemented. `filename' is the name of file in which to save cookies. If `filename' is not specified, ‘self.filename’ is used (whose default is the value passed to the constructor, if any); if ‘self.filename’ is *note None: 157, *note ValueError: 1fb. is raised. `ignore_discard': save even cookies set to be discarded. `ignore_expires': save even cookies that have expired The file is overwritten if it already exists, thus wiping all the cookies it contains. Saved cookies can be restored later using the *note load(): 2b83. or *note revert(): 2b84. methods. -- Method: FileCookieJar.load (filename=None, ignore_discard=False, ignore_expires=False) Load cookies from a file. Old cookies are kept unless overwritten by newly loaded ones. Arguments are as for *note save(): 2b94. The named file must be in the format understood by the class, or *note LoadError: 2b80. will be raised. Also, *note OSError: 1d3. may be raised, for example if the file does not exist. Changed in version 3.3: *note IOError: 992. used to be raised, it is now an alias of *note OSError: 1d3. -- Method: FileCookieJar.revert (filename=None, ignore_discard=False, ignore_expires=False) Clear all cookies and reload cookies from a saved file. *note revert(): 2b84. can raise the same exceptions as *note load(): 2b83. If there is a failure, the object’s state will not be altered. *note FileCookieJar: 2b81. instances have the following public attributes: -- Attribute: FileCookieJar.filename Filename of default file in which to keep cookies. This attribute may be assigned to. -- Attribute: FileCookieJar.delayload If true, load cookies lazily from disk. This attribute should not be assigned to. This is only a hint, since this only affects performance, not behaviour (unless the cookies on disk are changing). A *note CookieJar: 297c. object may ignore it. None of the *note FileCookieJar: 2b81. classes included in the standard library lazily loads cookies.  File: python.info, Node: FileCookieJar subclasses and co-operation with web browsers, Next: CookiePolicy Objects, Prev: CookieJar and FileCookieJar Objects, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.2 FileCookieJar subclasses and co-operation with web browsers ..................................................................... The following *note CookieJar: 297c. subclasses are provided for reading and writing. -- Class: http.cookiejar.MozillaCookieJar (filename, delayload=None, policy=None) A *note FileCookieJar: 2b81. that can load from and save cookies to disk in the Mozilla ‘cookies.txt’ file format (which is also used by the Lynx and Netscape browsers). Note: This loses information about RFC 2965(1) cookies, and also about newer or non-standard cookie-attributes such as ‘port’. Warning: Back up your cookies before saving if you have cookies whose loss / corruption would be inconvenient (there are some subtleties which may lead to slight changes in the file over a load / save round-trip). Also note that cookies saved while Mozilla is running will get clobbered by Mozilla. -- Class: http.cookiejar.LWPCookieJar (filename, delayload=None, policy=None) A *note FileCookieJar: 2b81. that can load from and save cookies to disk in format compatible with the libwww-perl library’s ‘Set-Cookie3’ file format. This is convenient if you want to store cookies in a human-readable file. Changed in version 3.8: The filename parameter supports a *note path-like object: 36a. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: CookiePolicy Objects, Next: DefaultCookiePolicy Objects, Prev: FileCookieJar subclasses and co-operation with web browsers, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.3 CookiePolicy Objects .............................. Objects implementing the *note CookiePolicy: 2b82. interface have the following methods: -- Method: CookiePolicy.set_ok (cookie, request) Return boolean value indicating whether cookie should be accepted from server. `cookie' is a *note Cookie: 2b88. instance. `request' is an object implementing the interface defined by the documentation for *note CookieJar.extract_cookies(): 2b8c. -- Method: CookiePolicy.return_ok (cookie, request) Return boolean value indicating whether cookie should be returned to server. `cookie' is a *note Cookie: 2b88. instance. `request' is an object implementing the interface defined by the documentation for *note CookieJar.add_cookie_header(): 2b8b. -- Method: CookiePolicy.domain_return_ok (domain, request) Return ‘False’ if cookies should not be returned, given cookie domain. This method is an optimization. It removes the need for checking every cookie with a particular domain (which might involve reading many files). Returning true from *note domain_return_ok(): 2b9d. and *note path_return_ok(): 2b9e. leaves all the work to *note return_ok(): 2b9c. If *note domain_return_ok(): 2b9d. returns true for the cookie domain, *note path_return_ok(): 2b9e. is called for the cookie path. Otherwise, *note path_return_ok(): 2b9e. and *note return_ok(): 2b9c. are never called for that cookie domain. If *note path_return_ok(): 2b9e. returns true, *note return_ok(): 2b9c. is called with the *note Cookie: 2b88. object itself for a full check. Otherwise, *note return_ok(): 2b9c. is never called for that cookie path. Note that *note domain_return_ok(): 2b9d. is called for every `cookie' domain, not just for the `request' domain. For example, the function might be called with both ‘".example.com"’ and ‘"www.example.com"’ if the request domain is ‘"www.example.com"’. The same goes for *note path_return_ok(): 2b9e. The `request' argument is as documented for *note return_ok(): 2b9c. -- Method: CookiePolicy.path_return_ok (path, request) Return ‘False’ if cookies should not be returned, given cookie path. See the documentation for *note domain_return_ok(): 2b9d. In addition to implementing the methods above, implementations of the *note CookiePolicy: 2b82. interface must also supply the following attributes, indicating which protocols should be used, and how. All of these attributes may be assigned to. -- Attribute: CookiePolicy.netscape Implement Netscape protocol. -- Attribute: CookiePolicy.rfc2965 Implement RFC 2965(1) protocol. -- Attribute: CookiePolicy.hide_cookie2 Don’t add ‘Cookie2’ header to requests (the presence of this header indicates to the server that we understand RFC 2965(2) cookies). The most useful way to define a *note CookiePolicy: 2b82. class is by subclassing from *note DefaultCookiePolicy: 2b86. and overriding some or all of the methods above. *note CookiePolicy: 2b82. itself may be used as a ‘null policy’ to allow setting and receiving any and all cookies (this is unlikely to be useful). ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2965.html (2) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: DefaultCookiePolicy Objects, Next: Cookie Objects<2>, Prev: CookiePolicy Objects, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.4 DefaultCookiePolicy Objects ..................................... Implements the standard rules for accepting and returning cookies. Both RFC 2965(1) and Netscape cookies are covered. RFC 2965 handling is switched off by default. The easiest way to provide your own policy is to override this class and call its methods in your overridden implementations before adding your own additional checks: import http.cookiejar class MyCookiePolicy(http.cookiejar.DefaultCookiePolicy): def set_ok(self, cookie, request): if not http.cookiejar.DefaultCookiePolicy.set_ok(self, cookie, request): return False if i_dont_want_to_store_this_cookie(cookie): return False return True In addition to the features required to implement the *note CookiePolicy: 2b82. interface, this class allows you to block and allow domains from setting and receiving cookies. There are also some strictness switches that allow you to tighten up the rather loose Netscape protocol rules a little bit (at the cost of blocking some benign cookies). A domain blacklist and whitelist is provided (both off by default). Only domains not in the blacklist and present in the whitelist (if the whitelist is active) participate in cookie setting and returning. Use the `blocked_domains' constructor argument, and ‘blocked_domains()’ and ‘set_blocked_domains()’ methods (and the corresponding argument and methods for `allowed_domains'). If you set a whitelist, you can turn it off again by setting it to *note None: 157. Domains in block or allow lists that do not start with a dot must equal the cookie domain to be matched. For example, ‘"example.com"’ matches a blacklist entry of ‘"example.com"’, but ‘"www.example.com"’ does not. Domains that do start with a dot are matched by more specific domains too. For example, both ‘"www.example.com"’ and ‘"www.coyote.example.com"’ match ‘".example.com"’ (but ‘"example.com"’ itself does not). IP addresses are an exception, and must match exactly. For example, if blocked_domains contains ‘"192.168.1.2"’ and ‘".168.1.2"’, 192.168.1.2 is blocked, but 193.168.1.2 is not. *note DefaultCookiePolicy: 2b86. implements the following additional methods: -- Method: DefaultCookiePolicy.blocked_domains () Return the sequence of blocked domains (as a tuple). -- Method: DefaultCookiePolicy.set_blocked_domains (blocked_domains) Set the sequence of blocked domains. -- Method: DefaultCookiePolicy.is_blocked (domain) Return whether `domain' is on the blacklist for setting or receiving cookies. -- Method: DefaultCookiePolicy.allowed_domains () Return *note None: 157, or the sequence of allowed domains (as a tuple). -- Method: DefaultCookiePolicy.set_allowed_domains (allowed_domains) Set the sequence of allowed domains, or *note None: 157. -- Method: DefaultCookiePolicy.is_not_allowed (domain) Return whether `domain' is not on the whitelist for setting or receiving cookies. *note DefaultCookiePolicy: 2b86. instances have the following attributes, which are all initialised from the constructor arguments of the same name, and which may all be assigned to. -- Attribute: DefaultCookiePolicy.rfc2109_as_netscape If true, request that the *note CookieJar: 297c. instance downgrade RFC 2109(2) cookies (ie. cookies received in a ‘Set-Cookie’ header with a version cookie-attribute of 1) to Netscape cookies by setting the version attribute of the *note Cookie: 2b88. instance to 0. The default value is *note None: 157, in which case RFC 2109 cookies are downgraded if and only if RFC 2965(3) handling is turned off. Therefore, RFC 2109 cookies are downgraded by default. General strictness switches: -- Attribute: DefaultCookiePolicy.strict_domain Don’t allow sites to set two-component domains with country-code top-level domains like ‘.co.uk’, ‘.gov.uk’, ‘.co.nz’.etc. This is far from perfect and isn’t guaranteed to work! RFC 2965(4) protocol strictness switches: -- Attribute: DefaultCookiePolicy.strict_rfc2965_unverifiable Follow RFC 2965(5) rules on unverifiable transactions (usually, an unverifiable transaction is one resulting from a redirect or a request for an image hosted on another site). If this is false, cookies are `never' blocked on the basis of verifiability Netscape protocol strictness switches: -- Attribute: DefaultCookiePolicy.strict_ns_unverifiable Apply RFC 2965(6) rules on unverifiable transactions even to Netscape cookies. -- Attribute: DefaultCookiePolicy.strict_ns_domain Flags indicating how strict to be with domain-matching rules for Netscape cookies. See below for acceptable values. -- Attribute: DefaultCookiePolicy.strict_ns_set_initial_dollar Ignore cookies in Set-Cookie: headers that have names starting with ‘'$'’. -- Attribute: DefaultCookiePolicy.strict_ns_set_path Don’t allow setting cookies whose path doesn’t path-match request URI. ‘strict_ns_domain’ is a collection of flags. Its value is constructed by or-ing together (for example, ‘DomainStrictNoDots|DomainStrictNonDomain’ means both flags are set). -- Attribute: DefaultCookiePolicy.DomainStrictNoDots When setting cookies, the ‘host prefix’ must not contain a dot (eg. ‘www.foo.bar.com’ can’t set a cookie for ‘.bar.com’, because ‘www.foo’ contains a dot). -- Attribute: DefaultCookiePolicy.DomainStrictNonDomain Cookies that did not explicitly specify a ‘domain’ cookie-attribute can only be returned to a domain equal to the domain that set the cookie (eg. ‘spam.example.com’ won’t be returned cookies from ‘example.com’ that had no ‘domain’ cookie-attribute). -- Attribute: DefaultCookiePolicy.DomainRFC2965Match When setting cookies, require a full RFC 2965(7) domain-match. The following attributes are provided for convenience, and are the most useful combinations of the above flags: -- Attribute: DefaultCookiePolicy.DomainLiberal Equivalent to 0 (ie. all of the above Netscape domain strictness flags switched off). -- Attribute: DefaultCookiePolicy.DomainStrict Equivalent to ‘DomainStrictNoDots|DomainStrictNonDomain’. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2965.html (2) https://tools.ietf.org/html/rfc2109.html (3) https://tools.ietf.org/html/rfc2965.html (4) https://tools.ietf.org/html/rfc2965.html (5) https://tools.ietf.org/html/rfc2965.html (6) https://tools.ietf.org/html/rfc2965.html (7) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: Cookie Objects<2>, Next: Examples<24>, Prev: DefaultCookiePolicy Objects, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.5 Cookie Objects ........................ *note Cookie: 2b88. instances have Python attributes roughly corresponding to the standard cookie-attributes specified in the various cookie standards. The correspondence is not one-to-one, because there are complicated rules for assigning default values, because the ‘max-age’ and ‘expires’ cookie-attributes contain equivalent information, and because RFC 2109(1) cookies may be ‘downgraded’ by *note http.cookiejar: 95. from version 1 to version 0 (Netscape) cookies. Assignment to these attributes should not be necessary other than in rare circumstances in a *note CookiePolicy: 2b82. method. The class does not enforce internal consistency, so you should know what you’re doing if you do that. -- Attribute: Cookie.version Integer or *note None: 157. Netscape cookies have *note version: 2bb6. 0. RFC 2965(2) and RFC 2109(3) cookies have a ‘version’ cookie-attribute of 1. However, note that *note http.cookiejar: 95. may ‘downgrade’ RFC 2109 cookies to Netscape cookies, in which case *note version: 2bb6. is 0. -- Attribute: Cookie.name Cookie name (a string). -- Attribute: Cookie.value Cookie value (a string), or *note None: 157. -- Attribute: Cookie.port String representing a port or a set of ports (eg. ‘80’, or ‘80,8080’), or *note None: 157. -- Attribute: Cookie.path Cookie path (a string, eg. ‘'/acme/rocket_launchers'’). -- Attribute: Cookie.secure ‘True’ if cookie should only be returned over a secure connection. -- Attribute: Cookie.expires Integer expiry date in seconds since epoch, or *note None: 157. See also the *note is_expired(): 2bbd. method. -- Attribute: Cookie.discard ‘True’ if this is a session cookie. -- Attribute: Cookie.comment String comment from the server explaining the function of this cookie, or *note None: 157. -- Attribute: Cookie.comment_url URL linking to a comment from the server explaining the function of this cookie, or *note None: 157. -- Attribute: Cookie.rfc2109 ‘True’ if this cookie was received as an RFC 2109(4) cookie (ie. the cookie arrived in a ‘Set-Cookie’ header, and the value of the Version cookie-attribute in that header was 1). This attribute is provided because *note http.cookiejar: 95. may ‘downgrade’ RFC 2109 cookies to Netscape cookies, in which case *note version: 2bb6. is 0. -- Attribute: Cookie.port_specified ‘True’ if a port or set of ports was explicitly specified by the server (in the ‘Set-Cookie’ / ‘Set-Cookie2’ header). -- Attribute: Cookie.domain_specified ‘True’ if a domain was explicitly specified by the server. -- Attribute: Cookie.domain_initial_dot ‘True’ if the domain explicitly specified by the server began with a dot (‘'.'’). Cookies may have additional non-standard cookie-attributes. These may be accessed using the following methods: -- Method: Cookie.has_nonstandard_attr (name) Return ‘True’ if cookie has the named cookie-attribute. -- Method: Cookie.get_nonstandard_attr (name, default=None) If cookie has the named cookie-attribute, return its value. Otherwise, return `default'. -- Method: Cookie.set_nonstandard_attr (name, value) Set the value of the named cookie-attribute. The *note Cookie: 2b88. class also defines the following method: -- Method: Cookie.is_expired (now=None) ‘True’ if cookie has passed the time at which the server requested it should expire. If `now' is given (in seconds since the epoch), return whether the cookie has expired at the specified time. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2109.html (2) https://tools.ietf.org/html/rfc2965.html (3) https://tools.ietf.org/html/rfc2109.html (4) https://tools.ietf.org/html/rfc2109.html  File: python.info, Node: Examples<24>, Prev: Cookie Objects<2>, Up: http cookiejar — Cookie handling for HTTP clients 5.21.24.6 Examples .................. The first example shows the most common usage of *note http.cookiejar: 95.: import http.cookiejar, urllib.request cj = http.cookiejar.CookieJar() opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") This example illustrates how to open a URL using your Netscape, Mozilla, or Lynx cookies (assumes Unix/Netscape convention for location of the cookies file): import os, http.cookiejar, urllib.request cj = http.cookiejar.MozillaCookieJar() cj.load(os.path.join(os.path.expanduser("~"), ".netscape", "cookies.txt")) opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") The next example illustrates the use of *note DefaultCookiePolicy: 2b86. Turn on RFC 2965(1) cookies, be more strict about domains when setting and returning Netscape cookies, and block some domains from setting cookies or having them returned: import urllib.request from http.cookiejar import CookieJar, DefaultCookiePolicy policy = DefaultCookiePolicy( rfc2965=True, strict_ns_domain=Policy.DomainStrict, blocked_domains=["ads.net", ".ads.net"]) cj = CookieJar(policy) opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2965.html  File: python.info, Node: xmlrpc — XMLRPC server and client modules, Next: xmlrpc client — XML-RPC client access, Prev: http cookiejar — Cookie handling for HTTP clients, Up: Internet Protocols and Support 5.21.25 ‘xmlrpc’ — XMLRPC server and client modules --------------------------------------------------- XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP as a transport. With it, a client can call methods with parameters on a remote server (the server is named by a URI) and get back structured data. ‘xmlrpc’ is a package that collects server and client modules implementing XML-RPC. The modules are: * *note xmlrpc.client: 13f. * *note xmlrpc.server: 140.  File: python.info, Node: xmlrpc client — XML-RPC client access, Next: xmlrpc server — Basic XML-RPC servers, Prev: xmlrpc — XMLRPC server and client modules, Up: Internet Protocols and Support 5.21.26 ‘xmlrpc.client’ — XML-RPC client access ----------------------------------------------- `Source code:' Lib/xmlrpc/client.py(1) __________________________________________________________________ XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP(S) as a transport. With it, a client can call methods with parameters on a remote server (the server is named by a URI) and get back structured data. This module supports writing XML-RPC client code; it handles all the details of translating between conformable Python objects and XML on the wire. Warning: The *note xmlrpc.client: 13f. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. Changed in version 3.5: For HTTPS URIs, *note xmlrpc.client: 13f. now performs all the necessary certificate and hostname checks by default. -- Class: xmlrpc.client.ServerProxy (uri, transport=None, encoding=None, verbose=False, allow_none=False, use_datetime=False, use_builtin_types=False, *, headers=(), context=None) A *note ServerProxy: 255. instance is an object that manages communication with a remote XML-RPC server. The required first argument is a URI (Uniform Resource Indicator), and will normally be the URL of the server. The optional second argument is a transport factory instance; by default it is an internal ‘SafeTransport’ instance for https: URLs and an internal HTTP ‘Transport’ instance otherwise. The optional third argument is an encoding, by default UTF-8. The optional fourth argument is a debugging flag. The following parameters govern the use of the returned proxy instance. If `allow_none' is true, the Python constant ‘None’ will be translated into XML; the default behaviour is for ‘None’ to raise a *note TypeError: 192. This is a commonly-used extension to the XML-RPC specification, but isn’t supported by all clients and servers; see http://ontosys.com/xml-rpc/extensions.php(2) for a description. The `use_builtin_types' flag can be used to cause date/time values to be presented as *note datetime.datetime: 194. objects and binary data to be presented as *note bytes: 331. objects; this flag is false by default. *note datetime.datetime: 194, *note bytes: 331. and *note bytearray: 332. objects may be passed to calls. The `headers' parameter is an optional sequence of HTTP headers to send with each request, expressed as a sequence of 2-tuples representing the header name and value. (e.g. ‘[(‘Header-Name’, ‘value’)]’). The obsolete `use_datetime' flag is similar to `use_builtin_types' but it applies only to date/time values. Changed in version 3.3: The `use_builtin_types' flag was added. Changed in version 3.8: The `headers' parameter was added. Both the HTTP and HTTPS transports support the URL syntax extension for HTTP Basic Authentication: ‘http://user:pass@host:port/path’. The ‘user:pass’ portion will be base64-encoded as an HTTP ‘Authorization’ header, and sent to the remote server as part of the connection process when invoking an XML-RPC method. You only need to use this if the remote server requires a Basic Authentication user and password. If an HTTPS URL is provided, `context' may be *note ssl.SSLContext: 3e4. and configures the SSL settings of the underlying HTTPS connection. The returned instance is a proxy object with methods that can be used to invoke corresponding RPC calls on the remote server. If the remote server supports the introspection API, the proxy can also be used to query the remote server for the methods it supports (service discovery) and fetch other server-associated metadata. Types that are conformable (e.g. that can be marshalled through XML), include the following (and except where noted, they are unmarshalled as the same Python type): XML-RPC type Python type --------------------------------------------------------------------------------------- ‘boolean’ *note bool: 183. ‘int’, ‘i1’, ‘i2’, ‘i4’, *note int: 184. in range from -2147483648 to 2147483647. ‘i8’ or ‘biginteger’ Values get the ‘<int>’ tag. ‘double’ or ‘float’ *note float: 187. Values get the ‘<double>’ tag. ‘string’ *note str: 330. ‘array’ *note list: 262. or *note tuple: 47e. containing conformable elements. Arrays are returned as *note lists: 262. ‘struct’ *note dict: 1b8. Keys must be strings, values may be any conformable type. Objects of user-defined classes can be passed in; only their *note __dict__: 4fc. attribute is transmitted. ‘dateTime.iso8601’ *note DateTime: 2bcd. or *note datetime.datetime: 194. Returned type depends on values of `use_builtin_types' and `use_datetime' flags. ‘base64’ *note Binary: 2bce, *note bytes: 331. or *note bytearray: 332. Returned type depends on the value of the `use_builtin_types' flag. ‘nil’ The ‘None’ constant. Passing is allowed only if `allow_none' is true. ‘bigdecimal’ *note decimal.Decimal: 188. Returned type only. This is the full set of data types supported by XML-RPC. Method calls may also raise a special *note Fault: 2bcf. instance, used to signal XML-RPC server errors, or *note ProtocolError: 2bd0. used to signal an error in the HTTP/HTTPS transport layer. Both *note Fault: 2bcf. and *note ProtocolError: 2bd0. derive from a base class called ‘Error’. Note that the xmlrpc client module currently does not marshal instances of subclasses of built-in types. When passing strings, characters special to XML such as ‘<’, ‘>’, and ‘&’ will be automatically escaped. However, it’s the caller’s responsibility to ensure that the string is free of characters that aren’t allowed in XML, such as the control characters with ASCII values between 0 and 31 (except, of course, tab, newline and carriage return); failing to do this will result in an XML-RPC request that isn’t well-formed XML. If you have to pass arbitrary bytes via XML-RPC, use *note bytes: 331. or *note bytearray: 332. classes or the *note Binary: 2bce. wrapper class described below. ‘Server’ is retained as an alias for *note ServerProxy: 255. for backwards compatibility. New code should use *note ServerProxy: 255. Changed in version 3.5: Added the `context' argument. Changed in version 3.6: Added support of type tags with prefixes (e.g. ‘ex:nil’). Added support of unmarshalling additional types used by Apache XML-RPC implementation for numerics: ‘i1’, ‘i2’, ‘i8’, ‘biginteger’, ‘float’ and ‘bigdecimal’. See ‘http://ws.apache.org/xmlrpc/types.html’ for a description. See also ........ XML-RPC HOWTO(3) A good description of XML-RPC operation and client software in several languages. Contains pretty much everything an XML-RPC client developer needs to know. XML-RPC Introspection(4) Describes the XML-RPC protocol extension for introspection. XML-RPC Specification(5) The official specification. Unofficial XML-RPC Errata(6) Fredrik Lundh’s “unofficial errata, intended to clarify certain details in the XML-RPC specification, as well as hint at ‘best practices’ to use when designing your own XML-RPC implementations.” * Menu: * ServerProxy Objects:: * DateTime Objects:: * Binary Objects:: * Fault Objects:: * ProtocolError Objects:: * MultiCall Objects:: * Convenience Functions:: * Example of Client Usage:: * Example of Client and Server Usage:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xmlrpc/client.py (2) https://web.archive.org/web/20130120074804/http://ontosys.com/xml-rpc/extensions.php (3) http://www.tldp.org/HOWTO/XML-RPC-HOWTO/index.html (4) http://xmlrpc-c.sourceforge.net/introspection.html (5) http://xmlrpc.scripting.com/spec.html (6) http://effbot.org/zone/xmlrpc-errata.htm  File: python.info, Node: ServerProxy Objects, Next: DateTime Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.1 ServerProxy Objects ............................. A *note ServerProxy: 255. instance has a method corresponding to each remote procedure call accepted by the XML-RPC server. Calling the method performs an RPC, dispatched by both name and argument signature (e.g. the same method name can be overloaded with multiple argument signatures). The RPC finishes by returning a value, which may be either returned data in a conformant type or a *note Fault: 2bcf. or *note ProtocolError: 2bd0. object indicating an error. Servers that support the XML introspection API support some common methods grouped under the reserved ‘system’ attribute: -- Method: ServerProxy.system.listMethods () This method returns a list of strings, one for each (non-system) method supported by the XML-RPC server. -- Method: ServerProxy.system.methodSignature (name) This method takes one parameter, the name of a method implemented by the XML-RPC server. It returns an array of possible signatures for this method. A signature is an array of types. The first of these types is the return type of the method, the rest are parameters. Because multiple signatures (ie. overloading) is permitted, this method returns a list of signatures rather than a singleton. Signatures themselves are restricted to the top level parameters expected by a method. For instance if a method expects one array of structs as a parameter, and it returns a string, its signature is simply “string, array”. If it expects three integers and returns a string, its signature is “string, int, int, int”. If no signature is defined for the method, a non-array value is returned. In Python this means that the type of the returned value will be something other than list. -- Method: ServerProxy.system.methodHelp (name) This method takes one parameter, the name of a method implemented by the XML-RPC server. It returns a documentation string describing the use of that method. If no such string is available, an empty string is returned. The documentation string may contain HTML markup. Changed in version 3.5: Instances of *note ServerProxy: 255. support the *note context manager: 568. protocol for closing the underlying transport. A working example follows. The server code: from xmlrpc.server import SimpleXMLRPCServer def is_even(n): return n % 2 == 0 server = SimpleXMLRPCServer(("localhost", 8000)) print("Listening on port 8000...") server.register_function(is_even, "is_even") server.serve_forever() The client code for the preceding server: import xmlrpc.client with xmlrpc.client.ServerProxy("http://localhost:8000/") as proxy: print("3 is even: %s" % str(proxy.is_even(3))) print("100 is even: %s" % str(proxy.is_even(100)))  File: python.info, Node: DateTime Objects, Next: Binary Objects, Prev: ServerProxy Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.2 DateTime Objects .......................... -- Class: xmlrpc.client.DateTime This class may be initialized with seconds since the epoch, a time tuple, an ISO 8601 time/date string, or a *note datetime.datetime: 194. instance. It has the following methods, supported mainly for internal use by the marshalling/unmarshalling code: -- Method: decode (string) Accept a string as the instance’s new time value. -- Method: encode (out) Write the XML-RPC encoding of this *note DateTime: 2bcd. item to the `out' stream object. It also supports certain of Python’s built-in operators through rich comparison and *note __repr__(): 33e. methods. A working example follows. The server code: import datetime from xmlrpc.server import SimpleXMLRPCServer import xmlrpc.client def today(): today = datetime.datetime.today() return xmlrpc.client.DateTime(today) server = SimpleXMLRPCServer(("localhost", 8000)) print("Listening on port 8000...") server.register_function(today, "today") server.serve_forever() The client code for the preceding server: import xmlrpc.client import datetime proxy = xmlrpc.client.ServerProxy("http://localhost:8000/") today = proxy.today() # convert the ISO8601 string to a datetime object converted = datetime.datetime.strptime(today.value, "%Y%m%dT%H:%M:%S") print("Today: %s" % converted.strftime("%d.%m.%Y, %H:%M"))  File: python.info, Node: Binary Objects, Next: Fault Objects, Prev: DateTime Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.3 Binary Objects ........................ -- Class: xmlrpc.client.Binary This class may be initialized from bytes data (which may include NULs). The primary access to the content of a *note Binary: 2bce. object is provided by an attribute: -- Attribute: data The binary data encapsulated by the *note Binary: 2bce. instance. The data is provided as a *note bytes: 331. object. *note Binary: 2bce. objects have the following methods, supported mainly for internal use by the marshalling/unmarshalling code: -- Method: decode (bytes) Accept a base64 *note bytes: 331. object and decode it as the instance’s new data. -- Method: encode (out) Write the XML-RPC base 64 encoding of this binary item to the `out' stream object. The encoded data will have newlines every 76 characters as per RFC 2045 section 6.8(1), which was the de facto standard base64 specification when the XML-RPC spec was written. It also supports certain of Python’s built-in operators through *note __eq__(): 33f. and *note __ne__(): e56. methods. Example usage of the binary objects. We’re going to transfer an image over XMLRPC: from xmlrpc.server import SimpleXMLRPCServer import xmlrpc.client def python_logo(): with open("python_logo.jpg", "rb") as handle: return xmlrpc.client.Binary(handle.read()) server = SimpleXMLRPCServer(("localhost", 8000)) print("Listening on port 8000...") server.register_function(python_logo, 'python_logo') server.serve_forever() The client gets the image and saves it to a file: import xmlrpc.client proxy = xmlrpc.client.ServerProxy("http://localhost:8000/") with open("fetched_python_logo.jpg", "wb") as handle: handle.write(proxy.python_logo().data) ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2045.html#section-6.8  File: python.info, Node: Fault Objects, Next: ProtocolError Objects, Prev: Binary Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.4 Fault Objects ....................... -- Class: xmlrpc.client.Fault A *note Fault: 2bcf. object encapsulates the content of an XML-RPC fault tag. Fault objects have the following attributes: -- Attribute: faultCode A string indicating the fault type. -- Attribute: faultString A string containing a diagnostic message associated with the fault. In the following example we’re going to intentionally cause a *note Fault: 2bcf. by returning a complex type object. The server code: from xmlrpc.server import SimpleXMLRPCServer # A marshalling error is going to occur because we're returning a # complex number def add(x, y): return x+y+0j server = SimpleXMLRPCServer(("localhost", 8000)) print("Listening on port 8000...") server.register_function(add, 'add') server.serve_forever() The client code for the preceding server: import xmlrpc.client proxy = xmlrpc.client.ServerProxy("http://localhost:8000/") try: proxy.add(2, 5) except xmlrpc.client.Fault as err: print("A fault occurred") print("Fault code: %d" % err.faultCode) print("Fault string: %s" % err.faultString)  File: python.info, Node: ProtocolError Objects, Next: MultiCall Objects, Prev: Fault Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.5 ProtocolError Objects ............................... -- Class: xmlrpc.client.ProtocolError A *note ProtocolError: 2bd0. object describes a protocol error in the underlying transport layer (such as a 404 ‘not found’ error if the server named by the URI does not exist). It has the following attributes: -- Attribute: url The URI or URL that triggered the error. -- Attribute: errcode The error code. -- Attribute: errmsg The error message or diagnostic string. -- Attribute: headers A dict containing the headers of the HTTP/HTTPS request that triggered the error. In the following example we’re going to intentionally cause a *note ProtocolError: 2bd0. by providing an invalid URI: import xmlrpc.client # create a ServerProxy with a URI that doesn't respond to XMLRPC requests proxy = xmlrpc.client.ServerProxy("http://google.com/") try: proxy.some_method() except xmlrpc.client.ProtocolError as err: print("A protocol error occurred") print("URL: %s" % err.url) print("HTTP/HTTPS headers: %s" % err.headers) print("Error code: %d" % err.errcode) print("Error message: %s" % err.errmsg)  File: python.info, Node: MultiCall Objects, Next: Convenience Functions, Prev: ProtocolError Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.6 MultiCall Objects ........................... The *note MultiCall: 2bea. object provides a way to encapsulate multiple calls to a remote server into a single request (1). -- Class: xmlrpc.client.MultiCall (server) Create an object used to boxcar method calls. `server' is the eventual target of the call. Calls can be made to the result object, but they will immediately return ‘None’, and only store the call name and parameters in the *note MultiCall: 2bea. object. Calling the object itself causes all stored calls to be transmitted as a single ‘system.multicall’ request. The result of this call is a *note generator: 9a2.; iterating over this generator yields the individual results. A usage example of this class follows. The server code: from xmlrpc.server import SimpleXMLRPCServer def add(x, y): return x + y def subtract(x, y): return x - y def multiply(x, y): return x * y def divide(x, y): return x // y # A simple server with simple arithmetic functions server = SimpleXMLRPCServer(("localhost", 8000)) print("Listening on port 8000...") server.register_multicall_functions() server.register_function(add, 'add') server.register_function(subtract, 'subtract') server.register_function(multiply, 'multiply') server.register_function(divide, 'divide') server.serve_forever() The client code for the preceding server: import xmlrpc.client proxy = xmlrpc.client.ServerProxy("http://localhost:8000/") multicall = xmlrpc.client.MultiCall(proxy) multicall.add(7, 3) multicall.subtract(7, 3) multicall.multiply(7, 3) multicall.divide(7, 3) result = multicall() print("7+3=%d, 7-3=%d, 7*3=%d, 7//3=%d" % tuple(result)) ---------- Footnotes ---------- (1) (1) This approach has been first presented in a discussion on xmlrpc.com (https://web.archive.org/web/20060624230303/http://www.xmlrpc.com/discuss/msgReader$1208?mode=topic).  File: python.info, Node: Convenience Functions, Next: Example of Client Usage, Prev: MultiCall Objects, Up: xmlrpc client — XML-RPC client access 5.21.26.7 Convenience Functions ............................... -- Function: xmlrpc.client.dumps (params, methodname=None, methodresponse=None, encoding=None, allow_none=False) Convert `params' into an XML-RPC request. or into a response if `methodresponse' is true. `params' can be either a tuple of arguments or an instance of the *note Fault: 2bcf. exception class. If `methodresponse' is true, only a single value can be returned, meaning that `params' must be of length 1. `encoding', if supplied, is the encoding to use in the generated XML; the default is UTF-8. Python’s *note None: 157. value cannot be used in standard XML-RPC; to allow using it via an extension, provide a true value for `allow_none'. -- Function: xmlrpc.client.loads (data, use_datetime=False, use_builtin_types=False) Convert an XML-RPC request or response into Python objects, a ‘(params, methodname)’. `params' is a tuple of argument; `methodname' is a string, or ‘None’ if no method name is present in the packet. If the XML-RPC packet represents a fault condition, this function will raise a *note Fault: 2bcf. exception. The `use_builtin_types' flag can be used to cause date/time values to be presented as *note datetime.datetime: 194. objects and binary data to be presented as *note bytes: 331. objects; this flag is false by default. The obsolete `use_datetime' flag is similar to `use_builtin_types' but it applies only to date/time values. Changed in version 3.3: The `use_builtin_types' flag was added.  File: python.info, Node: Example of Client Usage, Next: Example of Client and Server Usage, Prev: Convenience Functions, Up: xmlrpc client — XML-RPC client access 5.21.26.8 Example of Client Usage ................................. # simple test program (from the XML-RPC specification) from xmlrpc.client import ServerProxy, Error # server = ServerProxy("http://localhost:8000") # local server with ServerProxy("http://betty.userland.com") as proxy: print(proxy) try: print(proxy.examples.getStateName(41)) except Error as v: print("ERROR", v) To access an XML-RPC server through a HTTP proxy, you need to define a custom transport. The following example shows how: import http.client import xmlrpc.client class ProxiedTransport(xmlrpc.client.Transport): def set_proxy(self, host, port=None, headers=None): self.proxy = host, port self.proxy_headers = headers def make_connection(self, host): connection = http.client.HTTPConnection(*self.proxy) connection.set_tunnel(host, headers=self.proxy_headers) self._connection = host, connection return connection transport = ProxiedTransport() transport.set_proxy('proxy-server', 8080) server = xmlrpc.client.ServerProxy('http://betty.userland.com', transport=transport) print(server.examples.getStateName(41))  File: python.info, Node: Example of Client and Server Usage, Prev: Example of Client Usage, Up: xmlrpc client — XML-RPC client access 5.21.26.9 Example of Client and Server Usage ............................................ See *note SimpleXMLRPCServer Example: 2bf1.  File: python.info, Node: xmlrpc server — Basic XML-RPC servers, Next: ipaddress — IPv4/IPv6 manipulation library, Prev: xmlrpc client — XML-RPC client access, Up: Internet Protocols and Support 5.21.27 ‘xmlrpc.server’ — Basic XML-RPC servers ----------------------------------------------- `Source code:' Lib/xmlrpc/server.py(1) __________________________________________________________________ The *note xmlrpc.server: 140. module provides a basic server framework for XML-RPC servers written in Python. Servers can either be free standing, using *note SimpleXMLRPCServer: 2bf4, or embedded in a CGI environment, using *note CGIXMLRPCRequestHandler: 2bf5. Warning: The *note xmlrpc.server: 140. module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see *note XML vulnerabilities: 26f5. -- Class: xmlrpc.server.SimpleXMLRPCServer (addr, requestHandler=SimpleXMLRPCRequestHandler, logRequests=True, allow_none=False, encoding=None, bind_and_activate=True, use_builtin_types=False) Create a new server instance. This class provides methods for registration of functions that can be called by the XML-RPC protocol. The `requestHandler' parameter should be a factory for request handler instances; it defaults to *note SimpleXMLRPCRequestHandler: 2bf6. The `addr' and `requestHandler' parameters are passed to the *note socketserver.TCPServer: 2b1c. constructor. If `logRequests' is true (the default), requests will be logged; setting this parameter to false will turn off logging. The `allow_none' and `encoding' parameters are passed on to *note xmlrpc.client: 13f. and control the XML-RPC responses that will be returned from the server. The `bind_and_activate' parameter controls whether ‘server_bind()’ and ‘server_activate()’ are called immediately by the constructor; it defaults to true. Setting it to false allows code to manipulate the `allow_reuse_address' class variable before the address is bound. The `use_builtin_types' parameter is passed to the *note loads(): 2bed. function and controls which types are processed when date/times values or binary data are received; it defaults to false. Changed in version 3.3: The `use_builtin_types' flag was added. -- Class: xmlrpc.server.CGIXMLRPCRequestHandler (allow_none=False, encoding=None, use_builtin_types=False) Create a new instance to handle XML-RPC requests in a CGI environment. The `allow_none' and `encoding' parameters are passed on to *note xmlrpc.client: 13f. and control the XML-RPC responses that will be returned from the server. The `use_builtin_types' parameter is passed to the *note loads(): 2bed. function and controls which types are processed when date/times values or binary data are received; it defaults to false. Changed in version 3.3: The `use_builtin_types' flag was added. -- Class: xmlrpc.server.SimpleXMLRPCRequestHandler Create a new request handler instance. This request handler supports ‘POST’ requests and modifies logging so that the `logRequests' parameter to the *note SimpleXMLRPCServer: 2bf4. constructor parameter is honored. * Menu: * SimpleXMLRPCServer Objects:: * CGIXMLRPCRequestHandler:: * Documenting XMLRPC server:: * DocXMLRPCServer Objects:: * DocCGIXMLRPCRequestHandler:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/xmlrpc/server.py  File: python.info, Node: SimpleXMLRPCServer Objects, Next: CGIXMLRPCRequestHandler, Up: xmlrpc server — Basic XML-RPC servers 5.21.27.1 SimpleXMLRPCServer Objects .................................... The *note SimpleXMLRPCServer: 2bf4. class is based on *note socketserver.TCPServer: 2b1c. and provides a means of creating simple, stand alone XML-RPC servers. -- Method: SimpleXMLRPCServer.register_function (function=None, name=None) Register a function that can respond to XML-RPC requests. If `name' is given, it will be the method name associated with `function', otherwise ‘function.__name__’ will be used. `name' is a string, and may contain characters not legal in Python identifiers, including the period character. This method can also be used as a decorator. When used as a decorator, `name' can only be given as a keyword argument to register `function' under `name'. If no `name' is given, ‘function.__name__’ will be used. Changed in version 3.7: *note register_function(): 2bf9. can be used as a decorator. -- Method: SimpleXMLRPCServer.register_instance (instance, allow_dotted_names=False) Register an object which is used to expose method names which have not been registered using *note register_function(): 2bf9. If `instance' contains a ‘_dispatch()’ method, it is called with the requested method name and the parameters from the request. Its API is ‘def _dispatch(self, method, params)’ (note that `params' does not represent a variable argument list). If it calls an underlying function to perform its task, that function is called as ‘func(*params)’, expanding the parameter list. The return value from ‘_dispatch()’ is returned to the client as the result. If `instance' does not have a ‘_dispatch()’ method, it is searched for an attribute matching the name of the requested method. If the optional `allow_dotted_names' argument is true and the instance does not have a ‘_dispatch()’ method, then if the requested method name contains periods, each component of the method name is searched for individually, with the effect that a simple hierarchical search is performed. The value found from this search is then called with the parameters from the request, and the return value is passed back to the client. Warning: Enabling the `allow_dotted_names' option allows intruders to access your module’s global variables and may allow intruders to execute arbitrary code on your machine. Only use this option on a secure, closed network. -- Method: SimpleXMLRPCServer.register_introspection_functions () Registers the XML-RPC introspection functions ‘system.listMethods’, ‘system.methodHelp’ and ‘system.methodSignature’. -- Method: SimpleXMLRPCServer.register_multicall_functions () Registers the XML-RPC multicall function system.multicall. -- Attribute: SimpleXMLRPCRequestHandler.rpc_paths An attribute value that must be a tuple listing valid path portions of the URL for receiving XML-RPC requests. Requests posted to other paths will result in a 404 “no such page” HTTP error. If this tuple is empty, all paths will be considered valid. The default value is ‘('/', '/RPC2')’. * Menu: * SimpleXMLRPCServer Example::  File: python.info, Node: SimpleXMLRPCServer Example, Up: SimpleXMLRPCServer Objects 5.21.27.2 SimpleXMLRPCServer Example .................................... Server code: from xmlrpc.server import SimpleXMLRPCServer from xmlrpc.server import SimpleXMLRPCRequestHandler # Restrict to a particular path. class RequestHandler(SimpleXMLRPCRequestHandler): rpc_paths = ('/RPC2',) # Create server with SimpleXMLRPCServer(('localhost', 8000), requestHandler=RequestHandler) as server: server.register_introspection_functions() # Register pow() function; this will use the value of # pow.__name__ as the name, which is just 'pow'. server.register_function(pow) # Register a function under a different name def adder_function(x, y): return x + y server.register_function(adder_function, 'add') # Register an instance; all the methods of the instance are # published as XML-RPC methods (in this case, just 'mul'). class MyFuncs: def mul(self, x, y): return x * y server.register_instance(MyFuncs()) # Run the server's main loop server.serve_forever() The following client code will call the methods made available by the preceding server: import xmlrpc.client s = xmlrpc.client.ServerProxy('http://localhost:8000') print(s.pow(2,3)) # Returns 2**3 = 8 print(s.add(2,3)) # Returns 5 print(s.mul(5,2)) # Returns 5*2 = 10 # Print list of available methods print(s.system.listMethods()) ‘register_function()’ can also be used as a decorator. The previous server example can register functions in a decorator way: from xmlrpc.server import SimpleXMLRPCServer from xmlrpc.server import SimpleXMLRPCRequestHandler class RequestHandler(SimpleXMLRPCRequestHandler): rpc_paths = ('/RPC2',) with SimpleXMLRPCServer(('localhost', 8000), requestHandler=RequestHandler) as server: server.register_introspection_functions() # Register pow() function; this will use the value of # pow.__name__ as the name, which is just 'pow'. server.register_function(pow) # Register a function under a different name, using # register_function as a decorator. *name* can only be given # as a keyword argument. @server.register_function(name='add') def adder_function(x, y): return x + y # Register a function under function.__name__. @server.register_function def mul(x, y): return x * y server.serve_forever() The following example included in the ‘Lib/xmlrpc/server.py’ module shows a server allowing dotted names and registering a multicall function. Warning: Enabling the `allow_dotted_names' option allows intruders to access your module’s global variables and may allow intruders to execute arbitrary code on your machine. Only use this example only within a secure, closed network. import datetime class ExampleService: def getData(self): return '42' class currentTime: @staticmethod def getCurrentTime(): return datetime.datetime.now() with SimpleXMLRPCServer(("localhost", 8000)) as server: server.register_function(pow) server.register_function(lambda x,y: x+y, 'add') server.register_instance(ExampleService(), allow_dotted_names=True) server.register_multicall_functions() print('Serving XML-RPC on localhost port 8000') try: server.serve_forever() except KeyboardInterrupt: print("\nKeyboard interrupt received, exiting.") sys.exit(0) This ExampleService demo can be invoked from the command line: python -m xmlrpc.server The client that interacts with the above server is included in ‘Lib/xmlrpc/client.py’: server = ServerProxy("http://localhost:8000") try: print(server.currentTime.getCurrentTime()) except Error as v: print("ERROR", v) multi = MultiCall(server) multi.getData() multi.pow(2,9) multi.add(1,2) try: for response in multi(): print(response) except Error as v: print("ERROR", v) This client which interacts with the demo XMLRPC server can be invoked as: python -m xmlrpc.client  File: python.info, Node: CGIXMLRPCRequestHandler, Next: Documenting XMLRPC server, Prev: SimpleXMLRPCServer Objects, Up: xmlrpc server — Basic XML-RPC servers 5.21.27.3 CGIXMLRPCRequestHandler ................................. The *note CGIXMLRPCRequestHandler: 2bf5. class can be used to handle XML-RPC requests sent to Python CGI scripts. -- Method: CGIXMLRPCRequestHandler.register_function (function=None, name=None) Register a function that can respond to XML-RPC requests. If `name' is given, it will be the method name associated with `function', otherwise ‘function.__name__’ will be used. `name' is a string, and may contain characters not legal in Python identifiers, including the period character. This method can also be used as a decorator. When used as a decorator, `name' can only be given as a keyword argument to register `function' under `name'. If no `name' is given, ‘function.__name__’ will be used. Changed in version 3.7: *note register_function(): 2c00. can be used as a decorator. -- Method: CGIXMLRPCRequestHandler.register_instance (instance) Register an object which is used to expose method names which have not been registered using *note register_function(): 2c00. If instance contains a ‘_dispatch()’ method, it is called with the requested method name and the parameters from the request; the return value is returned to the client as the result. If instance does not have a ‘_dispatch()’ method, it is searched for an attribute matching the name of the requested method; if the requested method name contains periods, each component of the method name is searched for individually, with the effect that a simple hierarchical search is performed. The value found from this search is then called with the parameters from the request, and the return value is passed back to the client. -- Method: CGIXMLRPCRequestHandler.register_introspection_functions () Register the XML-RPC introspection functions ‘system.listMethods’, ‘system.methodHelp’ and ‘system.methodSignature’. -- Method: CGIXMLRPCRequestHandler.register_multicall_functions () Register the XML-RPC multicall function ‘system.multicall’. -- Method: CGIXMLRPCRequestHandler.handle_request (request_text=None) Handle an XML-RPC request. If `request_text' is given, it should be the POST data provided by the HTTP server, otherwise the contents of stdin will be used. Example: class MyFuncs: def mul(self, x, y): return x * y handler = CGIXMLRPCRequestHandler() handler.register_function(pow) handler.register_function(lambda x,y: x+y, 'add') handler.register_introspection_functions() handler.register_instance(MyFuncs()) handler.handle_request()  File: python.info, Node: Documenting XMLRPC server, Next: DocXMLRPCServer Objects, Prev: CGIXMLRPCRequestHandler, Up: xmlrpc server — Basic XML-RPC servers 5.21.27.4 Documenting XMLRPC server ................................... These classes extend the above classes to serve HTML documentation in response to HTTP GET requests. Servers can either be free standing, using *note DocXMLRPCServer: 2c06, or embedded in a CGI environment, using *note DocCGIXMLRPCRequestHandler: 2c07. -- Class: xmlrpc.server.DocXMLRPCServer (addr, requestHandler=DocXMLRPCRequestHandler, logRequests=True, allow_none=False, encoding=None, bind_and_activate=True, use_builtin_types=True) Create a new server instance. All parameters have the same meaning as for *note SimpleXMLRPCServer: 2bf4.; `requestHandler' defaults to *note DocXMLRPCRequestHandler: 2c08. Changed in version 3.3: The `use_builtin_types' flag was added. -- Class: xmlrpc.server.DocCGIXMLRPCRequestHandler Create a new instance to handle XML-RPC requests in a CGI environment. -- Class: xmlrpc.server.DocXMLRPCRequestHandler Create a new request handler instance. This request handler supports XML-RPC POST requests, documentation GET requests, and modifies logging so that the `logRequests' parameter to the *note DocXMLRPCServer: 2c06. constructor parameter is honored.  File: python.info, Node: DocXMLRPCServer Objects, Next: DocCGIXMLRPCRequestHandler, Prev: Documenting XMLRPC server, Up: xmlrpc server — Basic XML-RPC servers 5.21.27.5 DocXMLRPCServer Objects ................................. The *note DocXMLRPCServer: 2c06. class is derived from *note SimpleXMLRPCServer: 2bf4. and provides a means of creating self-documenting, stand alone XML-RPC servers. HTTP POST requests are handled as XML-RPC method calls. HTTP GET requests are handled by generating pydoc-style HTML documentation. This allows a server to provide its own web-based documentation. -- Method: DocXMLRPCServer.set_server_title (server_title) Set the title used in the generated HTML documentation. This title will be used inside the HTML “title” element. -- Method: DocXMLRPCServer.set_server_name (server_name) Set the name used in the generated HTML documentation. This name will appear at the top of the generated documentation inside a “h1” element. -- Method: DocXMLRPCServer.set_server_documentation (server_documentation) Set the description used in the generated HTML documentation. This description will appear as a paragraph, below the server name, in the documentation.  File: python.info, Node: DocCGIXMLRPCRequestHandler, Prev: DocXMLRPCServer Objects, Up: xmlrpc server — Basic XML-RPC servers 5.21.27.6 DocCGIXMLRPCRequestHandler .................................... The *note DocCGIXMLRPCRequestHandler: 2c07. class is derived from *note CGIXMLRPCRequestHandler: 2bf5. and provides a means of creating self-documenting, XML-RPC CGI scripts. HTTP POST requests are handled as XML-RPC method calls. HTTP GET requests are handled by generating pydoc-style HTML documentation. This allows a server to provide its own web-based documentation. -- Method: DocCGIXMLRPCRequestHandler.set_server_title (server_title) Set the title used in the generated HTML documentation. This title will be used inside the HTML “title” element. -- Method: DocCGIXMLRPCRequestHandler.set_server_name (server_name) Set the name used in the generated HTML documentation. This name will appear at the top of the generated documentation inside a “h1” element. -- Method: DocCGIXMLRPCRequestHandler.set_server_documentation (server_documentation) Set the description used in the generated HTML documentation. This description will appear as a paragraph, below the server name, in the documentation.  File: python.info, Node: ipaddress — IPv4/IPv6 manipulation library, Prev: xmlrpc server — Basic XML-RPC servers, Up: Internet Protocols and Support 5.21.28 ‘ipaddress’ — IPv4/IPv6 manipulation library ---------------------------------------------------- `Source code:' Lib/ipaddress.py(1) __________________________________________________________________ *note ipaddress: a2. provides the capabilities to create, manipulate and operate on IPv4 and IPv6 addresses and networks. The functions and classes in this module make it straightforward to handle various tasks related to IP addresses, including checking whether or not two hosts are on the same subnet, iterating over all hosts in a particular subnet, checking whether or not a string represents a valid IP address or network definition, and so on. This is the full module API reference—for an overview and introduction, see *note An introduction to the ipaddress module: 2c14. New in version 3.3. * Menu: * Convenience factory functions:: * IP Addresses:: * IP Network definitions:: * Interface objects:: * Other Module Level Functions:: * Custom Exceptions:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/ipaddress.py  File: python.info, Node: Convenience factory functions, Next: IP Addresses, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.1 Convenience factory functions ....................................... The *note ipaddress: a2. module provides factory functions to conveniently create IP addresses, networks and interfaces: -- Function: ipaddress.ip_address (address) Return an *note IPv4Address: 2c17. or *note IPv6Address: 2c18. object depending on the IP address passed as argument. Either IPv4 or IPv6 addresses may be supplied; integers less than 2**32 will be considered to be IPv4 by default. A *note ValueError: 1fb. is raised if `address' does not represent a valid IPv4 or IPv6 address. >>> ipaddress.ip_address('192.168.0.1') IPv4Address('192.168.0.1') >>> ipaddress.ip_address('2001:db8::') IPv6Address('2001:db8::') -- Function: ipaddress.ip_network (address, strict=True) Return an *note IPv4Network: 3a0. or *note IPv6Network: 39f. object depending on the IP address passed as argument. `address' is a string or integer representing the IP network. Either IPv4 or IPv6 networks may be supplied; integers less than 2**32 will be considered to be IPv4 by default. `strict' is passed to *note IPv4Network: 3a0. or *note IPv6Network: 39f. constructor. A *note ValueError: 1fb. is raised if `address' does not represent a valid IPv4 or IPv6 address, or if the network has host bits set. >>> ipaddress.ip_network('192.168.0.0/28') IPv4Network('192.168.0.0/28') -- Function: ipaddress.ip_interface (address) Return an *note IPv4Interface: 2c1b. or *note IPv6Interface: 2c1c. object depending on the IP address passed as argument. `address' is a string or integer representing the IP address. Either IPv4 or IPv6 addresses may be supplied; integers less than 2**32 will be considered to be IPv4 by default. A *note ValueError: 1fb. is raised if `address' does not represent a valid IPv4 or IPv6 address. One downside of these convenience functions is that the need to handle both IPv4 and IPv6 formats means that error messages provide minimal information on the precise error, as the functions don’t know whether the IPv4 or IPv6 format was intended. More detailed error reporting can be obtained by calling the appropriate version specific class constructors directly.  File: python.info, Node: IP Addresses, Next: IP Network definitions, Prev: Convenience factory functions, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.2 IP Addresses ...................... * Menu: * Address objects:: * Conversion to Strings and Integers:: * Operators: Operators<3>.  File: python.info, Node: Address objects, Next: Conversion to Strings and Integers, Up: IP Addresses 5.21.28.3 Address objects ......................... The *note IPv4Address: 2c17. and *note IPv6Address: 2c18. objects share a lot of common attributes. Some attributes that are only meaningful for IPv6 addresses are also implemented by *note IPv4Address: 2c17. objects, in order to make it easier to write code that handles both IP versions correctly. Address objects are *note hashable: 10c8, so they can be used as keys in dictionaries. -- Class: ipaddress.IPv4Address (address) Construct an IPv4 address. An *note AddressValueError: 2c1f. is raised if `address' is not a valid IPv4 address. The following constitutes a valid IPv4 address: 1. A string in decimal-dot notation, consisting of four decimal integers in the inclusive range 0–255, separated by dots (e.g. ‘192.168.0.1’). Each integer represents an octet (byte) in the address. Leading zeroes are tolerated only for values less than 8 (as there is no ambiguity between the decimal and octal interpretations of such strings). 2. An integer that fits into 32 bits. 3. An integer packed into a *note bytes: 331. object of length 4 (most significant octet first). >>> ipaddress.IPv4Address('192.168.0.1') IPv4Address('192.168.0.1') >>> ipaddress.IPv4Address(3232235521) IPv4Address('192.168.0.1') >>> ipaddress.IPv4Address(b'\xC0\xA8\x00\x01') IPv4Address('192.168.0.1') -- Attribute: version The appropriate version number: ‘4’ for IPv4, ‘6’ for IPv6. -- Attribute: max_prefixlen The total number of bits in the address representation for this version: ‘32’ for IPv4, ‘128’ for IPv6. The prefix defines the number of leading bits in an address that are compared to determine whether or not an address is part of a network. -- Attribute: compressed -- Attribute: exploded The string representation in dotted decimal notation. Leading zeroes are never included in the representation. As IPv4 does not define a shorthand notation for addresses with octets set to zero, these two attributes are always the same as ‘str(addr)’ for IPv4 addresses. Exposing these attributes makes it easier to write display code that can handle both IPv4 and IPv6 addresses. -- Attribute: packed The binary representation of this address - a *note bytes: 331. object of the appropriate length (most significant octet first). This is 4 bytes for IPv4 and 16 bytes for IPv6. -- Attribute: reverse_pointer The name of the reverse DNS PTR record for the IP address, e.g.: >>> ipaddress.ip_address("127.0.0.1").reverse_pointer '1.0.0.127.in-addr.arpa' >>> ipaddress.ip_address("2001:db8::1").reverse_pointer '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa' This is the name that could be used for performing a PTR lookup, not the resolved hostname itself. New in version 3.5. -- Attribute: is_multicast ‘True’ if the address is reserved for multicast use. See RFC 3171(1) (for IPv4) or RFC 2373(2) (for IPv6). -- Attribute: is_private ‘True’ if the address is allocated for private networks. See iana-ipv4-special-registry(3) (for IPv4) or iana-ipv6-special-registry(4) (for IPv6). -- Attribute: is_global ‘True’ if the address is allocated for public networks. See iana-ipv4-special-registry(5) (for IPv4) or iana-ipv6-special-registry(6) (for IPv6). New in version 3.4. -- Attribute: is_unspecified ‘True’ if the address is unspecified. See RFC 5735(7) (for IPv4) or RFC 2373(8) (for IPv6). -- Attribute: is_reserved ‘True’ if the address is otherwise IETF reserved. -- Attribute: is_loopback ‘True’ if this is a loopback address. See RFC 3330(9) (for IPv4) or RFC 2373(10) (for IPv6). -- Attribute: is_link_local ‘True’ if the address is reserved for link-local usage. See RFC 3927(11). -- Class: ipaddress.IPv6Address (address) Construct an IPv6 address. An *note AddressValueError: 2c1f. is raised if `address' is not a valid IPv6 address. The following constitutes a valid IPv6 address: 1. A string consisting of eight groups of four hexadecimal digits, each group representing 16 bits. The groups are separated by colons. This describes an `exploded' (longhand) notation. The string can also be `compressed' (shorthand notation) by various means. See RFC 4291(12) for details. For example, ‘"0000:0000:0000:0000:0000:0abc:0007:0def"’ can be compressed to ‘"::abc:7:def"’. 2. An integer that fits into 128 bits. 3. An integer packed into a *note bytes: 331. object of length 16, big-endian. >>> ipaddress.IPv6Address('2001:db8::1000') IPv6Address('2001:db8::1000') -- Attribute: compressed The short form of the address representation, with leading zeroes in groups omitted and the longest sequence of groups consisting entirely of zeroes collapsed to a single empty group. This is also the value returned by ‘str(addr)’ for IPv6 addresses. -- Attribute: exploded The long form of the address representation, with all leading zeroes and groups consisting entirely of zeroes included. For the following attributes, see the corresponding documentation of the *note IPv4Address: 2c17. class: -- Attribute: packed -- Attribute: reverse_pointer -- Attribute: version -- Attribute: max_prefixlen -- Attribute: is_multicast -- Attribute: is_private -- Attribute: is_global -- Attribute: is_unspecified -- Attribute: is_reserved -- Attribute: is_loopback -- Attribute: is_link_local New in version 3.4: is_global -- Attribute: is_site_local ‘True’ if the address is reserved for site-local usage. Note that the site-local address space has been deprecated by RFC 3879(13). Use *note is_private: 2c27. to test if this address is in the space of unique local addresses as defined by RFC 4193(14). -- Attribute: ipv4_mapped For addresses that appear to be IPv4 mapped addresses (starting with ‘::FFFF/96’), this property will report the embedded IPv4 address. For any other address, this property will be ‘None’. -- Attribute: sixtofour For addresses that appear to be 6to4 addresses (starting with ‘2002::/16’) as defined by RFC 3056(15), this property will report the embedded IPv4 address. For any other address, this property will be ‘None’. -- Attribute: teredo For addresses that appear to be Teredo addresses (starting with ‘2001::/32’) as defined by RFC 4380(16), this property will report the embedded ‘(server, client)’ IP address pair. For any other address, this property will be ‘None’. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc3171.html (2) https://tools.ietf.org/html/rfc2373.html (3) https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml (4) https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml (5) https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml (6) https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml (7) https://tools.ietf.org/html/rfc5735.html (8) https://tools.ietf.org/html/rfc2373.html (9) https://tools.ietf.org/html/rfc3330.html (10) https://tools.ietf.org/html/rfc2373.html (11) https://tools.ietf.org/html/rfc3927.html (12) https://tools.ietf.org/html/rfc4291.html (13) https://tools.ietf.org/html/rfc3879.html (14) https://tools.ietf.org/html/rfc4193.html (15) https://tools.ietf.org/html/rfc3056.html (16) https://tools.ietf.org/html/rfc4380.html  File: python.info, Node: Conversion to Strings and Integers, Next: Operators<3>, Prev: Address objects, Up: IP Addresses 5.21.28.4 Conversion to Strings and Integers ............................................ To interoperate with networking interfaces such as the socket module, addresses must be converted to strings or integers. This is handled using the *note str(): 330. and *note int(): 184. builtin functions: >>> str(ipaddress.IPv4Address('192.168.0.1')) '192.168.0.1' >>> int(ipaddress.IPv4Address('192.168.0.1')) 3232235521 >>> str(ipaddress.IPv6Address('::1')) '::1' >>> int(ipaddress.IPv6Address('::1')) 1  File: python.info, Node: Operators<3>, Prev: Conversion to Strings and Integers, Up: IP Addresses 5.21.28.5 Operators ................... Address objects support some operators. Unless stated otherwise, operators can only be applied between compatible objects (i.e. IPv4 with IPv4, IPv6 with IPv6). * Menu: * Comparison operators:: * Arithmetic operators::  File: python.info, Node: Comparison operators, Next: Arithmetic operators, Up: Operators<3> 5.21.28.6 Comparison operators .............................. Address objects can be compared with the usual set of comparison operators. Some examples: >>> IPv4Address('127.0.0.2') > IPv4Address('127.0.0.1') True >>> IPv4Address('127.0.0.2') == IPv4Address('127.0.0.1') False >>> IPv4Address('127.0.0.2') != IPv4Address('127.0.0.1') True  File: python.info, Node: Arithmetic operators, Prev: Comparison operators, Up: Operators<3> 5.21.28.7 Arithmetic operators .............................. Integers can be added to or subtracted from address objects. Some examples: >>> IPv4Address('127.0.0.2') + 3 IPv4Address('127.0.0.5') >>> IPv4Address('127.0.0.2') - 3 IPv4Address('126.255.255.255') >>> IPv4Address('255.255.255.255') + 1 Traceback (most recent call last): File "<stdin>", line 1, in <module> ipaddress.AddressValueError: 4294967296 (>= 2**32) is not permitted as an IPv4 address  File: python.info, Node: IP Network definitions, Next: Interface objects, Prev: IP Addresses, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.8 IP Network definitions ................................ The *note IPv4Network: 3a0. and *note IPv6Network: 39f. objects provide a mechanism for defining and inspecting IP network definitions. A network definition consists of a `mask' and a `network address', and as such defines a range of IP addresses that equal the network address when masked (binary AND) with the mask. For example, a network definition with the mask ‘255.255.255.0’ and the network address ‘192.168.1.0’ consists of IP addresses in the inclusive range ‘192.168.1.0’ to ‘192.168.1.255’. * Menu: * Prefix, net mask and host mask: Prefix net mask and host mask. * Network objects:: * Operators: Operators<4>.  File: python.info, Node: Prefix net mask and host mask, Next: Network objects, Up: IP Network definitions 5.21.28.9 Prefix, net mask and host mask ........................................ There are several equivalent ways to specify IP network masks. A `prefix' ‘/<nbits>’ is a notation that denotes how many high-order bits are set in the network mask. A `net mask' is an IP address with some number of high-order bits set. Thus the prefix ‘/24’ is equivalent to the net mask ‘255.255.255.0’ in IPv4, or ‘ffff:ff00::’ in IPv6. In addition, a `host mask' is the logical inverse of a `net mask', and is sometimes used (for example in Cisco access control lists) to denote a network mask. The host mask equivalent to ‘/24’ in IPv4 is ‘0.0.0.255’.  File: python.info, Node: Network objects, Next: Operators<4>, Prev: Prefix net mask and host mask, Up: IP Network definitions 5.21.28.10 Network objects .......................... All attributes implemented by address objects are implemented by network objects as well. In addition, network objects implement additional attributes. All of these are common between *note IPv4Network: 3a0. and *note IPv6Network: 39f, so to avoid duplication they are only documented for *note IPv4Network: 3a0. Network objects are *note hashable: 10c8, so they can be used as keys in dictionaries. -- Class: ipaddress.IPv4Network (address, strict=True) Construct an IPv4 network definition. `address' can be one of the following: 1. A string consisting of an IP address and an optional mask, separated by a slash (‘/’). The IP address is the network address, and the mask can be either a single number, which means it’s a `prefix', or a string representation of an IPv4 address. If it’s the latter, the mask is interpreted as a `net mask' if it starts with a non-zero field, or as a `host mask' if it starts with a zero field, with the single exception of an all-zero mask which is treated as a `net mask'. If no mask is provided, it’s considered to be ‘/32’. For example, the following `address' specifications are equivalent: ‘192.168.1.0/24’, ‘192.168.1.0/255.255.255.0’ and ‘192.168.1.0/0.0.0.255’. 2. An integer that fits into 32 bits. This is equivalent to a single-address network, with the network address being `address' and the mask being ‘/32’. 3. An integer packed into a *note bytes: 331. object of length 4, big-endian. The interpretation is similar to an integer `address'. 4. A two-tuple of an address description and a netmask, where the address description is either a string, a 32-bits integer, a 4-bytes packed integer, or an existing IPv4Address object; and the netmask is either an integer representing the prefix length (e.g. ‘24’) or a string representing the prefix mask (e.g. ‘255.255.255.0’). An *note AddressValueError: 2c1f. is raised if `address' is not a valid IPv4 address. A *note NetmaskValueError: 2c44. is raised if the mask is not valid for an IPv4 address. If `strict' is ‘True’ and host bits are set in the supplied address, then *note ValueError: 1fb. is raised. Otherwise, the host bits are masked out to determine the appropriate network address. Unless stated otherwise, all network methods accepting other network/address objects will raise *note TypeError: 192. if the argument’s IP version is incompatible to ‘self’. Changed in version 3.5: Added the two-tuple form for the `address' constructor parameter. -- Attribute: version -- Attribute: max_prefixlen Refer to the corresponding attribute documentation in *note IPv4Address: 2c17. -- Attribute: is_multicast -- Attribute: is_private -- Attribute: is_unspecified -- Attribute: is_reserved -- Attribute: is_loopback -- Attribute: is_link_local These attributes are true for the network as a whole if they are true for both the network address and the broadcast address. -- Attribute: network_address The network address for the network. The network address and the prefix length together uniquely define a network. -- Attribute: broadcast_address The broadcast address for the network. Packets sent to the broadcast address should be received by every host on the network. -- Attribute: hostmask The host mask, as an *note IPv4Address: 2c17. object. -- Attribute: netmask The net mask, as an *note IPv4Address: 2c17. object. -- Attribute: with_prefixlen -- Attribute: compressed -- Attribute: exploded A string representation of the network, with the mask in prefix notation. ‘with_prefixlen’ and ‘compressed’ are always the same as ‘str(network)’. ‘exploded’ uses the exploded form the network address. -- Attribute: with_netmask A string representation of the network, with the mask in net mask notation. -- Attribute: with_hostmask A string representation of the network, with the mask in host mask notation. -- Attribute: num_addresses The total number of addresses in the network. -- Attribute: prefixlen Length of the network prefix, in bits. -- Method: hosts () Returns an iterator over the usable hosts in the network. The usable hosts are all the IP addresses that belong to the network, except the network address itself and the network broadcast address. For networks with a mask length of 31, the network address and network broadcast address are also included in the result. >>> list(ip_network('192.0.2.0/29').hosts()) [IPv4Address('192.0.2.1'), IPv4Address('192.0.2.2'), IPv4Address('192.0.2.3'), IPv4Address('192.0.2.4'), IPv4Address('192.0.2.5'), IPv4Address('192.0.2.6')] >>> list(ip_network('192.0.2.0/31').hosts()) [IPv4Address('192.0.2.0'), IPv4Address('192.0.2.1')] -- Method: overlaps (other) ‘True’ if this network is partly or wholly contained in `other' or `other' is wholly contained in this network. -- Method: address_exclude (network) Computes the network definitions resulting from removing the given `network' from this one. Returns an iterator of network objects. Raises *note ValueError: 1fb. if `network' is not completely contained in this network. >>> n1 = ip_network('192.0.2.0/28') >>> n2 = ip_network('192.0.2.1/32') >>> list(n1.address_exclude(n2)) [IPv4Network('192.0.2.8/29'), IPv4Network('192.0.2.4/30'), IPv4Network('192.0.2.2/31'), IPv4Network('192.0.2.0/32')] -- Method: subnets (prefixlen_diff=1, new_prefix=None) The subnets that join to make the current network definition, depending on the argument values. `prefixlen_diff' is the amount our prefix length should be increased by. `new_prefix' is the desired new prefix of the subnets; it must be larger than our prefix. One and only one of `prefixlen_diff' and `new_prefix' must be set. Returns an iterator of network objects. >>> list(ip_network('192.0.2.0/24').subnets()) [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')] >>> list(ip_network('192.0.2.0/24').subnets(prefixlen_diff=2)) [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'), IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')] >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=26)) [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'), IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')] >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=23)) Traceback (most recent call last): File "<stdin>", line 1, in <module> raise ValueError('new prefix must be longer') ValueError: new prefix must be longer >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=25)) [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')] -- Method: supernet (prefixlen_diff=1, new_prefix=None) The supernet containing this network definition, depending on the argument values. `prefixlen_diff' is the amount our prefix length should be decreased by. `new_prefix' is the desired new prefix of the supernet; it must be smaller than our prefix. One and only one of `prefixlen_diff' and `new_prefix' must be set. Returns a single network object. >>> ip_network('192.0.2.0/24').supernet() IPv4Network('192.0.2.0/23') >>> ip_network('192.0.2.0/24').supernet(prefixlen_diff=2) IPv4Network('192.0.0.0/22') >>> ip_network('192.0.2.0/24').supernet(new_prefix=20) IPv4Network('192.0.0.0/20') -- Method: subnet_of (other) Return ‘True’ if this network is a subnet of `other'. >>> a = ip_network('192.168.1.0/24') >>> b = ip_network('192.168.1.128/30') >>> b.subnet_of(a) True New in version 3.7. -- Method: supernet_of (other) Return ‘True’ if this network is a supernet of `other'. >>> a = ip_network('192.168.1.0/24') >>> b = ip_network('192.168.1.128/30') >>> a.supernet_of(b) True New in version 3.7. -- Method: compare_networks (other) Compare this network to `other'. In this comparison only the network addresses are considered; host bits aren’t. Returns either ‘-1’, ‘0’ or ‘1’. >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.2/32')) -1 >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.0/32')) 1 >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.1/32')) 0 Deprecated since version 3.7: It uses the same ordering and comparison algorithm as “<”, “==”, and “>” -- Class: ipaddress.IPv6Network (address, strict=True) Construct an IPv6 network definition. `address' can be one of the following: 1. A string consisting of an IP address and an optional prefix length, separated by a slash (‘/’). The IP address is the network address, and the prefix length must be a single number, the `prefix'. If no prefix length is provided, it’s considered to be ‘/128’. Note that currently expanded netmasks are not supported. That means ‘2001:db00::0/24’ is a valid argument while ‘2001:db00::0/ffff:ff00::’ not. 2. An integer that fits into 128 bits. This is equivalent to a single-address network, with the network address being `address' and the mask being ‘/128’. 3. An integer packed into a *note bytes: 331. object of length 16, big-endian. The interpretation is similar to an integer `address'. 4. A two-tuple of an address description and a netmask, where the address description is either a string, a 128-bits integer, a 16-bytes packed integer, or an existing IPv6Address object; and the netmask is an integer representing the prefix length. An *note AddressValueError: 2c1f. is raised if `address' is not a valid IPv6 address. A *note NetmaskValueError: 2c44. is raised if the mask is not valid for an IPv6 address. If `strict' is ‘True’ and host bits are set in the supplied address, then *note ValueError: 1fb. is raised. Otherwise, the host bits are masked out to determine the appropriate network address. Changed in version 3.5: Added the two-tuple form for the `address' constructor parameter. -- Attribute: version -- Attribute: max_prefixlen -- Attribute: is_multicast -- Attribute: is_private -- Attribute: is_unspecified -- Attribute: is_reserved -- Attribute: is_loopback -- Attribute: is_link_local -- Attribute: network_address -- Attribute: broadcast_address -- Attribute: hostmask -- Attribute: netmask -- Attribute: with_prefixlen -- Attribute: compressed -- Attribute: exploded -- Attribute: with_netmask -- Attribute: with_hostmask -- Attribute: num_addresses -- Attribute: prefixlen -- Method: hosts () Returns an iterator over the usable hosts in the network. The usable hosts are all the IP addresses that belong to the network, except the Subnet-Router anycast address. For networks with a mask length of 127, the Subnet-Router anycast address is also included in the result. -- Method: overlaps (other) -- Method: address_exclude (network) -- Method: subnets (prefixlen_diff=1, new_prefix=None) -- Method: supernet (prefixlen_diff=1, new_prefix=None) -- Method: subnet_of (other) -- Method: supernet_of (other) -- Method: compare_networks (other) Refer to the corresponding attribute documentation in *note IPv4Network: 3a0. -- Attribute: is_site_local These attribute is true for the network as a whole if it is true for both the network address and the broadcast address.  File: python.info, Node: Operators<4>, Prev: Network objects, Up: IP Network definitions 5.21.28.11 Operators .................... Network objects support some operators. Unless stated otherwise, operators can only be applied between compatible objects (i.e. IPv4 with IPv4, IPv6 with IPv6). * Menu: * Logical operators:: * Iteration: Iteration<2>. * Networks as containers of addresses::  File: python.info, Node: Logical operators, Next: Iteration<2>, Up: Operators<4> 5.21.28.12 Logical operators ............................ Network objects can be compared with the usual set of logical operators. Network objects are ordered first by network address, then by net mask.  File: python.info, Node: Iteration<2>, Next: Networks as containers of addresses, Prev: Logical operators, Up: Operators<4> 5.21.28.13 Iteration .................... Network objects can be iterated to list all the addresses belonging to the network. For iteration, `all' hosts are returned, including unusable hosts (for usable hosts, use the *note hosts(): 2c58. method). An example: >>> for addr in IPv4Network('192.0.2.0/28'): ... addr ... IPv4Address('192.0.2.0') IPv4Address('192.0.2.1') IPv4Address('192.0.2.2') IPv4Address('192.0.2.3') IPv4Address('192.0.2.4') IPv4Address('192.0.2.5') IPv4Address('192.0.2.6') IPv4Address('192.0.2.7') IPv4Address('192.0.2.8') IPv4Address('192.0.2.9') IPv4Address('192.0.2.10') IPv4Address('192.0.2.11') IPv4Address('192.0.2.12') IPv4Address('192.0.2.13') IPv4Address('192.0.2.14') IPv4Address('192.0.2.15')  File: python.info, Node: Networks as containers of addresses, Prev: Iteration<2>, Up: Operators<4> 5.21.28.14 Networks as containers of addresses .............................................. Network objects can act as containers of addresses. Some examples: >>> IPv4Network('192.0.2.0/28')[0] IPv4Address('192.0.2.0') >>> IPv4Network('192.0.2.0/28')[15] IPv4Address('192.0.2.15') >>> IPv4Address('192.0.2.6') in IPv4Network('192.0.2.0/28') True >>> IPv4Address('192.0.3.6') in IPv4Network('192.0.2.0/28') False  File: python.info, Node: Interface objects, Next: Other Module Level Functions, Prev: IP Network definitions, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.15 Interface objects ............................ Interface objects are *note hashable: 10c8, so they can be used as keys in dictionaries. -- Class: ipaddress.IPv4Interface (address) Construct an IPv4 interface. The meaning of `address' is as in the constructor of *note IPv4Network: 3a0, except that arbitrary host addresses are always accepted. *note IPv4Interface: 2c1b. is a subclass of *note IPv4Address: 2c17, so it inherits all the attributes from that class. In addition, the following attributes are available: -- Attribute: ip The address (*note IPv4Address: 2c17.) without network information. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.ip IPv4Address('192.0.2.5') -- Attribute: network The network (*note IPv4Network: 3a0.) this interface belongs to. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.network IPv4Network('192.0.2.0/24') -- Attribute: with_prefixlen A string representation of the interface with the mask in prefix notation. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_prefixlen '192.0.2.5/24' -- Attribute: with_netmask A string representation of the interface with the network as a net mask. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_netmask '192.0.2.5/255.255.255.0' -- Attribute: with_hostmask A string representation of the interface with the network as a host mask. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_hostmask '192.0.2.5/0.0.0.255' -- Class: ipaddress.IPv6Interface (address) Construct an IPv6 interface. The meaning of `address' is as in the constructor of *note IPv6Network: 39f, except that arbitrary host addresses are always accepted. *note IPv6Interface: 2c1c. is a subclass of *note IPv6Address: 2c18, so it inherits all the attributes from that class. In addition, the following attributes are available: -- Attribute: ip -- Attribute: network -- Attribute: with_prefixlen -- Attribute: with_netmask -- Attribute: with_hostmask Refer to the corresponding attribute documentation in *note IPv4Interface: 2c1b. * Menu: * Operators: Operators<5>.  File: python.info, Node: Operators<5>, Up: Interface objects 5.21.28.16 Operators .................... Interface objects support some operators. Unless stated otherwise, operators can only be applied between compatible objects (i.e. IPv4 with IPv4, IPv6 with IPv6). * Menu: * Logical operators: Logical operators<2>.  File: python.info, Node: Logical operators<2>, Up: Operators<5> 5.21.28.17 Logical operators ............................ Interface objects can be compared with the usual set of logical operators. For equality comparison (‘==’ and ‘!=’), both the IP address and network must be the same for the objects to be equal. An interface will not compare equal to any address or network object. For ordering (‘<’, ‘>’, etc) the rules are different. Interface and address objects with the same IP version can be compared, and the address objects will always sort before the interface objects. Two interface objects are first compared by their networks and, if those are the same, then by their IP addresses.  File: python.info, Node: Other Module Level Functions, Next: Custom Exceptions, Prev: Interface objects, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.18 Other Module Level Functions ....................................... The module also provides the following module level functions: -- Function: ipaddress.v4_int_to_packed (address) Represent an address as 4 packed bytes in network (big-endian) order. `address' is an integer representation of an IPv4 IP address. A *note ValueError: 1fb. is raised if the integer is negative or too large to be an IPv4 IP address. >>> ipaddress.ip_address(3221225985) IPv4Address('192.0.2.1') >>> ipaddress.v4_int_to_packed(3221225985) b'\xc0\x00\x02\x01' -- Function: ipaddress.v6_int_to_packed (address) Represent an address as 16 packed bytes in network (big-endian) order. `address' is an integer representation of an IPv6 IP address. A *note ValueError: 1fb. is raised if the integer is negative or too large to be an IPv6 IP address. -- Function: ipaddress.summarize_address_range (first, last) Return an iterator of the summarized network range given the first and last IP addresses. `first' is the first *note IPv4Address: 2c17. or *note IPv6Address: 2c18. in the range and `last' is the last *note IPv4Address: 2c17. or *note IPv6Address: 2c18. in the range. A *note TypeError: 192. is raised if `first' or `last' are not IP addresses or are not of the same version. A *note ValueError: 1fb. is raised if `last' is not greater than `first' or if `first' address version is not 4 or 6. >>> [ipaddr for ipaddr in ipaddress.summarize_address_range( ... ipaddress.IPv4Address('192.0.2.0'), ... ipaddress.IPv4Address('192.0.2.130'))] [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/31'), IPv4Network('192.0.2.130/32')] -- Function: ipaddress.collapse_addresses (addresses) Return an iterator of the collapsed *note IPv4Network: 3a0. or *note IPv6Network: 39f. objects. `addresses' is an iterator of *note IPv4Network: 3a0. or *note IPv6Network: 39f. objects. A *note TypeError: 192. is raised if `addresses' contains mixed version objects. >>> [ipaddr for ipaddr in ... ipaddress.collapse_addresses([ipaddress.IPv4Network('192.0.2.0/25'), ... ipaddress.IPv4Network('192.0.2.128/25')])] [IPv4Network('192.0.2.0/24')] -- Function: ipaddress.get_mixed_type_key (obj) Return a key suitable for sorting between networks and addresses. Address and Network objects are not sortable by default; they’re fundamentally different, so the expression: IPv4Address('192.0.2.0') <= IPv4Network('192.0.2.0/24') doesn’t make sense. There are some times however, where you may wish to have *note ipaddress: a2. sort these anyway. If you need to do this, you can use this function as the `key' argument to *note sorted(): 444. `obj' is either a network or address object.  File: python.info, Node: Custom Exceptions, Prev: Other Module Level Functions, Up: ipaddress — IPv4/IPv6 manipulation library 5.21.28.19 Custom Exceptions ............................ To support more specific error reporting from class constructors, the module defines the following exceptions: -- Exception: ipaddress.AddressValueError (ValueError) Any value error related to the address. -- Exception: ipaddress.NetmaskValueError (ValueError) Any value error related to the net mask.  File: python.info, Node: Multimedia Services, Next: Internationalization, Prev: Internet Protocols and Support, Up: The Python Standard Library 5.22 Multimedia Services ======================== The modules described in this chapter implement various algorithms or interfaces that are mainly useful for multimedia applications. They are available at the discretion of the installation. Here’s an overview: * Menu: * audioop — Manipulate raw audio data:: * aifc — Read and write AIFF and AIFC files:: * sunau — Read and write Sun AU files:: * wave — Read and write WAV files:: * chunk — Read IFF chunked data:: * colorsys — Conversions between color systems:: * imghdr — Determine the type of an image:: * sndhdr — Determine type of sound file:: * ossaudiodev — Access to OSS-compatible audio devices::  File: python.info, Node: audioop — Manipulate raw audio data, Next: aifc — Read and write AIFF and AIFC files, Up: Multimedia Services 5.22.1 ‘audioop’ — Manipulate raw audio data -------------------------------------------- __________________________________________________________________ The *note audioop: d. module contains some useful operations on sound fragments. It operates on sound fragments consisting of signed integer samples 8, 16, 24 or 32 bits wide, stored in *note bytes-like objects: 5e8. All scalar items are integers, unless specified otherwise. Changed in version 3.4: Support for 24-bit samples was added. All functions now accept any *note bytes-like object: 5e8. String input now results in an immediate error. This module provides support for a-LAW, u-LAW and Intel/DVI ADPCM encodings. A few of the more complicated operations only take 16-bit samples, otherwise the sample size (in bytes) is always a parameter of the operation. The module defines the following variables and functions: -- Exception: audioop.error This exception is raised on all errors, such as unknown number of bytes per sample, etc. -- Function: audioop.add (fragment1, fragment2, width) Return a fragment which is the addition of the two samples passed as parameters. `width' is the sample width in bytes, either ‘1’, ‘2’, ‘3’ or ‘4’. Both fragments should have the same length. Samples are truncated in case of overflow. -- Function: audioop.adpcm2lin (adpcmfragment, width, state) Decode an Intel/DVI ADPCM coded fragment to a linear fragment. See the description of *note lin2adpcm(): 2c98. for details on ADPCM coding. Return a tuple ‘(sample, newstate)’ where the sample has the width specified in `width'. -- Function: audioop.alaw2lin (fragment, width) Convert sound fragments in a-LAW encoding to linearly encoded sound fragments. a-LAW encoding always uses 8 bits samples, so `width' refers only to the sample width of the output fragment here. -- Function: audioop.avg (fragment, width) Return the average over all samples in the fragment. -- Function: audioop.avgpp (fragment, width) Return the average peak-peak value over all samples in the fragment. No filtering is done, so the usefulness of this routine is questionable. -- Function: audioop.bias (fragment, width, bias) Return a fragment that is the original fragment with a bias added to each sample. Samples wrap around in case of overflow. -- Function: audioop.byteswap (fragment, width) “Byteswap” all samples in a fragment and returns the modified fragment. Converts big-endian samples to little-endian and vice versa. New in version 3.4. -- Function: audioop.cross (fragment, width) Return the number of zero crossings in the fragment passed as an argument. -- Function: audioop.findfactor (fragment, reference) Return a factor `F' such that ‘rms(add(fragment, mul(reference, -F)))’ is minimal, i.e., return the factor with which you should multiply `reference' to make it match as well as possible to `fragment'. The fragments should both contain 2-byte samples. The time taken by this routine is proportional to ‘len(fragment)’. -- Function: audioop.findfit (fragment, reference) Try to match `reference' as well as possible to a portion of `fragment' (which should be the longer fragment). This is (conceptually) done by taking slices out of `fragment', using *note findfactor(): 2c9e. to compute the best match, and minimizing the result. The fragments should both contain 2-byte samples. Return a tuple ‘(offset, factor)’ where `offset' is the (integer) offset into `fragment' where the optimal match started and `factor' is the (floating-point) factor as per *note findfactor(): 2c9e. -- Function: audioop.findmax (fragment, length) Search `fragment' for a slice of length `length' samples (not bytes!) with maximum energy, i.e., return `i' for which ‘rms(fragment[i*2:(i+length)*2])’ is maximal. The fragments should both contain 2-byte samples. The routine takes time proportional to ‘len(fragment)’. -- Function: audioop.getsample (fragment, width, index) Return the value of sample `index' from the fragment. -- Function: audioop.lin2adpcm (fragment, width, state) Convert samples to 4 bit Intel/DVI ADPCM encoding. ADPCM coding is an adaptive coding scheme, whereby each 4 bit number is the difference between one sample and the next, divided by a (varying) step. The Intel/DVI ADPCM algorithm has been selected for use by the IMA, so it may well become a standard. `state' is a tuple containing the state of the coder. The coder returns a tuple ‘(adpcmfrag, newstate)’, and the `newstate' should be passed to the next call of *note lin2adpcm(): 2c98. In the initial call, ‘None’ can be passed as the state. `adpcmfrag' is the ADPCM coded fragment packed 2 4-bit values per byte. -- Function: audioop.lin2alaw (fragment, width) Convert samples in the audio fragment to a-LAW encoding and return this as a bytes object. a-LAW is an audio encoding format whereby you get a dynamic range of about 13 bits using only 8 bit samples. It is used by the Sun audio hardware, among others. -- Function: audioop.lin2lin (fragment, width, newwidth) Convert samples between 1-, 2-, 3- and 4-byte formats. Note: In some audio formats, such as .WAV files, 16, 24 and 32 bit samples are signed, but 8 bit samples are unsigned. So when converting to 8 bit wide samples for these formats, you need to also add 128 to the result: new_frames = audioop.lin2lin(frames, old_width, 1) new_frames = audioop.bias(new_frames, 1, 128) The same, in reverse, has to be applied when converting from 8 to 16, 24 or 32 bit width samples. -- Function: audioop.lin2ulaw (fragment, width) Convert samples in the audio fragment to u-LAW encoding and return this as a bytes object. u-LAW is an audio encoding format whereby you get a dynamic range of about 14 bits using only 8 bit samples. It is used by the Sun audio hardware, among others. -- Function: audioop.max (fragment, width) Return the maximum of the `absolute value' of all samples in a fragment. -- Function: audioop.maxpp (fragment, width) Return the maximum peak-peak value in the sound fragment. -- Function: audioop.minmax (fragment, width) Return a tuple consisting of the minimum and maximum values of all samples in the sound fragment. -- Function: audioop.mul (fragment, width, factor) Return a fragment that has all samples in the original fragment multiplied by the floating-point value `factor'. Samples are truncated in case of overflow. -- Function: audioop.ratecv (fragment, width, nchannels, inrate, outrate, state[, weightA[, weightB]]) Convert the frame rate of the input fragment. `state' is a tuple containing the state of the converter. The converter returns a tuple ‘(newfragment, newstate)’, and `newstate' should be passed to the next call of *note ratecv(): 2ca9. The initial call should pass ‘None’ as the state. The `weightA' and `weightB' arguments are parameters for a simple digital filter and default to ‘1’ and ‘0’ respectively. -- Function: audioop.reverse (fragment, width) Reverse the samples in a fragment and returns the modified fragment. -- Function: audioop.rms (fragment, width) Return the root-mean-square of the fragment, i.e. ‘sqrt(sum(S_i^2)/n)’. This is a measure of the power in an audio signal. -- Function: audioop.tomono (fragment, width, lfactor, rfactor) Convert a stereo fragment to a mono fragment. The left channel is multiplied by `lfactor' and the right channel by `rfactor' before adding the two channels to give a mono signal. -- Function: audioop.tostereo (fragment, width, lfactor, rfactor) Generate a stereo fragment from a mono fragment. Each pair of samples in the stereo fragment are computed from the mono sample, whereby left channel samples are multiplied by `lfactor' and right channel samples by `rfactor'. -- Function: audioop.ulaw2lin (fragment, width) Convert sound fragments in u-LAW encoding to linearly encoded sound fragments. u-LAW encoding always uses 8 bits samples, so `width' refers only to the sample width of the output fragment here. Note that operations such as *note mul(): 2ca8. or *note max(): 2ca5. make no distinction between mono and stereo fragments, i.e. all samples are treated equal. If this is a problem the stereo fragment should be split into two mono fragments first and recombined later. Here is an example of how to do that: def mul_stereo(sample, width, lfactor, rfactor): lsample = audioop.tomono(sample, width, 1, 0) rsample = audioop.tomono(sample, width, 0, 1) lsample = audioop.mul(lsample, width, lfactor) rsample = audioop.mul(rsample, width, rfactor) lsample = audioop.tostereo(lsample, width, 1, 0) rsample = audioop.tostereo(rsample, width, 0, 1) return audioop.add(lsample, rsample, width) If you use the ADPCM coder to build network packets and you want your protocol to be stateless (i.e. to be able to tolerate packet loss) you should not only transmit the data but also the state. Note that you should send the `initial' state (the one you passed to *note lin2adpcm(): 2c98.) along to the decoder, not the final state (as returned by the coder). If you want to use *note struct.Struct: 14b5. to store the state in binary you can code the first element (the predicted value) in 16 bits and the second (the delta index) in 8. The ADPCM coders have never been tried against other ADPCM coders, only against themselves. It could well be that I misinterpreted the standards in which case they will not be interoperable with the respective standards. The ‘find*()’ routines might look a bit funny at first sight. They are primarily meant to do echo cancellation. A reasonably fast way to do this is to pick the most energetic piece of the output sample, locate that in the input sample and subtract the whole output sample from the input sample: def echocancel(outputdata, inputdata): pos = audioop.findmax(outputdata, 800) # one tenth second out_test = outputdata[pos*2:] in_test = inputdata[pos*2:] ipos, factor = audioop.findfit(in_test, out_test) # Optional (for better cancellation): # factor = audioop.findfactor(in_test[ipos*2:ipos*2+len(out_test)], # out_test) prefill = '\0'*(pos+ipos)*2 postfill = '\0'*(len(inputdata)-len(prefill)-len(outputdata)) outputdata = prefill + audioop.mul(outputdata, 2, -factor) + postfill return audioop.add(inputdata, outputdata, 2)  File: python.info, Node: aifc — Read and write AIFF and AIFC files, Next: sunau — Read and write Sun AU files, Prev: audioop — Manipulate raw audio data, Up: Multimedia Services 5.22.2 ‘aifc’ — Read and write AIFF and AIFC files -------------------------------------------------- `Source code:' Lib/aifc.py(1) __________________________________________________________________ This module provides support for reading and writing AIFF and AIFF-C files. AIFF is Audio Interchange File Format, a format for storing digital audio samples in a file. AIFF-C is a newer version of the format that includes the ability to compress the audio data. Audio files have a number of parameters that describe the audio data. The sampling rate or frame rate is the number of times per second the sound is sampled. The number of channels indicate if the audio is mono, stereo, or quadro. Each frame consists of one sample per channel. The sample size is the size in bytes of each sample. Thus a frame consists of ‘nchannels * samplesize’ bytes, and a second’s worth of audio consists of ‘nchannels * samplesize * framerate’ bytes. For example, CD quality audio has a sample size of two bytes (16 bits), uses two channels (stereo) and has a frame rate of 44,100 frames/second. This gives a frame size of 4 bytes (2*2), and a second’s worth occupies 2*2*44100 bytes (176,400 bytes). Module *note aifc: 5. defines the following function: -- Function: aifc.open (file, mode=None) Open an AIFF or AIFF-C file and return an object instance with methods that are described below. The argument `file' is either a string naming a file or a *note file object: b42. `mode' must be ‘'r'’ or ‘'rb'’ when the file must be opened for reading, or ‘'w'’ or ‘'wb'’ when the file must be opened for writing. If omitted, ‘file.mode’ is used if it exists, otherwise ‘'rb'’ is used. When used for writing, the file object should be seekable, unless you know ahead of time how many samples you are going to write in total and use ‘writeframesraw()’ and ‘setnframes()’. The *note open(): 45b. function may be used in a *note with: 6e9. statement. When the ‘with’ block completes, the *note close(): 81c. method is called. Changed in version 3.4: Support for the *note with: 6e9. statement was added. Objects returned by *note open(): 45b. when a file is opened for reading have the following methods: -- Method: aifc.getnchannels () Return the number of audio channels (1 for mono, 2 for stereo). -- Method: aifc.getsampwidth () Return the size in bytes of individual samples. -- Method: aifc.getframerate () Return the sampling rate (number of audio frames per second). -- Method: aifc.getnframes () Return the number of audio frames in the file. -- Method: aifc.getcomptype () Return a bytes array of length 4 describing the type of compression used in the audio file. For AIFF files, the returned value is ‘b'NONE'’. -- Method: aifc.getcompname () Return a bytes array convertible to a human-readable description of the type of compression used in the audio file. For AIFF files, the returned value is ‘b'not compressed'’. -- Method: aifc.getparams () Returns a *note namedtuple(): 1b7. ‘(nchannels, sampwidth, framerate, nframes, comptype, compname)’, equivalent to output of the ‘get*()’ methods. -- Method: aifc.getmarkers () Return a list of markers in the audio file. A marker consists of a tuple of three elements. The first is the mark ID (an integer), the second is the mark position in frames from the beginning of the data (an integer), the third is the name of the mark (a string). -- Method: aifc.getmark (id) Return the tuple as described in *note getmarkers(): 2cb7. for the mark with the given `id'. -- Method: aifc.readframes (nframes) Read and return the next `nframes' frames from the audio file. The returned data is a string containing for each frame the uncompressed samples of all channels. -- Method: aifc.rewind () Rewind the read pointer. The next *note readframes(): 2cb9. will start from the beginning. -- Method: aifc.setpos (pos) Seek to the specified frame number. -- Method: aifc.tell () Return the current frame number. -- Method: aifc.close () Close the AIFF file. After calling this method, the object can no longer be used. Objects returned by *note open(): 45b. when a file is opened for writing have all the above methods, except for ‘readframes()’ and ‘setpos()’. In addition the following methods exist. The ‘get*()’ methods can only be called after the corresponding ‘set*()’ methods have been called. Before the first ‘writeframes()’ or ‘writeframesraw()’, all parameters except for the number of frames must be filled in. -- Method: aifc.aiff () Create an AIFF file. The default is that an AIFF-C file is created, unless the name of the file ends in ‘'.aiff'’ in which case the default is an AIFF file. -- Method: aifc.aifc () Create an AIFF-C file. The default is that an AIFF-C file is created, unless the name of the file ends in ‘'.aiff'’ in which case the default is an AIFF file. -- Method: aifc.setnchannels (nchannels) Specify the number of channels in the audio file. -- Method: aifc.setsampwidth (width) Specify the size in bytes of audio samples. -- Method: aifc.setframerate (rate) Specify the sampling frequency in frames per second. -- Method: aifc.setnframes (nframes) Specify the number of frames that are to be written to the audio file. If this parameter is not set, or not set correctly, the file needs to support seeking. -- Method: aifc.setcomptype (type, name) Specify the compression type. If not specified, the audio data will not be compressed. In AIFF files, compression is not possible. The name parameter should be a human-readable description of the compression type as a bytes array, the type parameter should be a bytes array of length 4. Currently the following compression types are supported: ‘b'NONE'’, ‘b'ULAW'’, ‘b'ALAW'’, ‘b'G722'’. -- Method: aifc.setparams (nchannels, sampwidth, framerate, comptype, compname) Set all the above parameters at once. The argument is a tuple consisting of the various parameters. This means that it is possible to use the result of a *note getparams(): 81b. call as argument to *note setparams(): 2cc4. -- Method: aifc.setmark (id, pos, name) Add a mark with the given id (larger than 0), and the given name at the given position. This method can be called at any time before *note close(): 81c. -- Method: aifc.tell () Return the current write position in the output file. Useful in combination with *note setmark(): 2cc5. -- Method: aifc.writeframes (data) Write data to the output file. This method can only be called after the audio file parameters have been set. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. -- Method: aifc.writeframesraw (data) Like *note writeframes(): 81e, except that the header of the audio file is not updated. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. -- Method: aifc.close () Close the AIFF file. The header of the file is updated to reflect the actual size of the audio data. After calling this method, the object can no longer be used. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/aifc.py  File: python.info, Node: sunau — Read and write Sun AU files, Next: wave — Read and write WAV files, Prev: aifc — Read and write AIFF and AIFC files, Up: Multimedia Services 5.22.3 ‘sunau’ — Read and write Sun AU files -------------------------------------------- `Source code:' Lib/sunau.py(1) __________________________________________________________________ The *note sunau: fa. module provides a convenient interface to the Sun AU sound format. Note that this module is interface-compatible with the modules *note aifc: 5. and *note wave: 127. An audio file consists of a header followed by the data. The fields of the header are: Field Contents ------------------------------------------------------------------------ magic word The four bytes ‘.snd’. header size Size of the header, including info, in bytes. data size Physical size of the data, in bytes. encoding Indicates how the audio samples are encoded. sample rate The sampling rate. # of channels The number of channels in the samples. info ASCII string giving a description of the audio file (padded with null bytes). Apart from the info field, all header fields are 4 bytes in size. They are all 32-bit unsigned integers encoded in big-endian byte order. The *note sunau: fa. module defines the following functions: -- Function: sunau.open (file, mode) If `file' is a string, open the file by that name, otherwise treat it as a seekable file-like object. `mode' can be any of ‘'r'’ Read only mode. ‘'w'’ Write only mode. Note that it does not allow read/write files. A `mode' of ‘'r'’ returns an ‘AU_read’ object, while a `mode' of ‘'w'’ or ‘'wb'’ returns an ‘AU_write’ object. -- Function: sunau.openfp (file, mode) A synonym for *note open(): 472, maintained for backwards compatibility. Deprecated since version 3.7, will be removed in version 3.9. The *note sunau: fa. module defines the following exception: -- Exception: sunau.Error An error raised when something is impossible because of Sun AU specs or implementation deficiency. The *note sunau: fa. module defines the following data items: -- Data: sunau.AUDIO_FILE_MAGIC An integer every valid Sun AU file begins with, stored in big-endian form. This is the string ‘.snd’ interpreted as an integer. -- Data: sunau.AUDIO_FILE_ENCODING_MULAW_8 -- Data: sunau.AUDIO_FILE_ENCODING_LINEAR_8 -- Data: sunau.AUDIO_FILE_ENCODING_LINEAR_16 -- Data: sunau.AUDIO_FILE_ENCODING_LINEAR_24 -- Data: sunau.AUDIO_FILE_ENCODING_LINEAR_32 -- Data: sunau.AUDIO_FILE_ENCODING_ALAW_8 Values of the encoding field from the AU header which are supported by this module. -- Data: sunau.AUDIO_FILE_ENCODING_FLOAT -- Data: sunau.AUDIO_FILE_ENCODING_DOUBLE -- Data: sunau.AUDIO_FILE_ENCODING_ADPCM_G721 -- Data: sunau.AUDIO_FILE_ENCODING_ADPCM_G722 -- Data: sunau.AUDIO_FILE_ENCODING_ADPCM_G723_3 -- Data: sunau.AUDIO_FILE_ENCODING_ADPCM_G723_5 Additional known values of the encoding field from the AU header, but which are not supported by this module. * Menu: * AU_read Objects:: * AU_write Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/sunau.py  File: python.info, Node: AU_read Objects, Next: AU_write Objects, Up: sunau — Read and write Sun AU files 5.22.3.1 AU_read Objects ........................ AU_read objects, as returned by *note open(): 472. above, have the following methods: -- Method: AU_read.close () Close the stream, and make the instance unusable. (This is called automatically on deletion.) -- Method: AU_read.getnchannels () Returns number of audio channels (1 for mono, 2 for stereo). -- Method: AU_read.getsampwidth () Returns sample width in bytes. -- Method: AU_read.getframerate () Returns sampling frequency. -- Method: AU_read.getnframes () Returns number of audio frames. -- Method: AU_read.getcomptype () Returns compression type. Supported compression types are ‘'ULAW'’, ‘'ALAW'’ and ‘'NONE'’. -- Method: AU_read.getcompname () Human-readable version of *note getcomptype(): 2cdd. The supported types have the respective names ‘'CCITT G.711 u-law'’, ‘'CCITT G.711 A-law'’ and ‘'not compressed'’. -- Method: AU_read.getparams () Returns a *note namedtuple(): 1b7. ‘(nchannels, sampwidth, framerate, nframes, comptype, compname)’, equivalent to output of the ‘get*()’ methods. -- Method: AU_read.readframes (n) Reads and returns at most `n' frames of audio, as a *note bytes: 331. object. The data will be returned in linear format. If the original data is in u-LAW format, it will be converted. -- Method: AU_read.rewind () Rewind the file pointer to the beginning of the audio stream. The following two methods define a term “position” which is compatible between them, and is otherwise implementation dependent. -- Method: AU_read.setpos (pos) Set the file pointer to the specified position. Only values returned from *note tell(): 2ce3. should be used for `pos'. -- Method: AU_read.tell () Return current file pointer position. Note that the returned value has nothing to do with the actual position in the file. The following two functions are defined for compatibility with the *note aifc: 5, and don’t do anything interesting. -- Method: AU_read.getmarkers () Returns ‘None’. -- Method: AU_read.getmark (id) Raise an error.  File: python.info, Node: AU_write Objects, Prev: AU_read Objects, Up: sunau — Read and write Sun AU files 5.22.3.2 AU_write Objects ......................... AU_write objects, as returned by *note open(): 472. above, have the following methods: -- Method: AU_write.setnchannels (n) Set the number of channels. -- Method: AU_write.setsampwidth (n) Set the sample width (in bytes.) Changed in version 3.4: Added support for 24-bit samples. -- Method: AU_write.setframerate (n) Set the frame rate. -- Method: AU_write.setnframes (n) Set the number of frames. This can be later changed, when and if more frames are written. -- Method: AU_write.setcomptype (type, name) Set the compression type and description. Only ‘'NONE'’ and ‘'ULAW'’ are supported on output. -- Method: AU_write.setparams (tuple) The `tuple' should be ‘(nchannels, sampwidth, framerate, nframes, comptype, compname)’, with values valid for the ‘set*()’ methods. Set all parameters. -- Method: AU_write.tell () Return current position in the file, with the same disclaimer for the *note AU_read.tell(): 2ce3. and *note AU_read.setpos(): 2ce2. methods. -- Method: AU_write.writeframesraw (data) Write audio frames, without correcting `nframes'. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. -- Method: AU_write.writeframes (data) Write audio frames and make sure `nframes' is correct. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. -- Method: AU_write.close () Make sure `nframes' is correct, and close the file. This method is called upon deletion. Note that it is invalid to set any parameters after calling ‘writeframes()’ or ‘writeframesraw()’.  File: python.info, Node: wave — Read and write WAV files, Next: chunk — Read IFF chunked data, Prev: sunau — Read and write Sun AU files, Up: Multimedia Services 5.22.4 ‘wave’ — Read and write WAV files ---------------------------------------- `Source code:' Lib/wave.py(1) __________________________________________________________________ The *note wave: 127. module provides a convenient interface to the WAV sound format. It does not support compression/decompression, but it does support mono/stereo. The *note wave: 127. module defines the following function and exception: -- Function: wave.open (file, mode=None) If `file' is a string, open the file by that name, otherwise treat it as a file-like object. `mode' can be: ‘'rb'’ Read only mode. ‘'wb'’ Write only mode. Note that it does not allow read/write WAV files. A `mode' of ‘'rb'’ returns a ‘Wave_read’ object, while a `mode' of ‘'wb'’ returns a ‘Wave_write’ object. If `mode' is omitted and a file-like object is passed as `file', ‘file.mode’ is used as the default value for `mode'. If you pass in a file-like object, the wave object will not close it when its ‘close()’ method is called; it is the caller’s responsibility to close the file object. The *note open(): 476. function may be used in a *note with: 6e9. statement. When the ‘with’ block completes, the *note Wave_read.close(): 2cf1. or *note Wave_write.close(): 2cf2. method is called. Changed in version 3.4: Added support for unseekable files. -- Function: wave.openfp (file, mode) A synonym for *note open(): 476, maintained for backwards compatibility. Deprecated since version 3.7, will be removed in version 3.9. -- Exception: wave.Error An error raised when something is impossible because it violates the WAV specification or hits an implementation deficiency. * Menu: * Wave_read Objects:: * Wave_write Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/wave.py  File: python.info, Node: Wave_read Objects, Next: Wave_write Objects, Up: wave — Read and write WAV files 5.22.4.1 Wave_read Objects .......................... Wave_read objects, as returned by *note open(): 476, have the following methods: -- Method: Wave_read.close () Close the stream if it was opened by *note wave: 127, and make the instance unusable. This is called automatically on object collection. -- Method: Wave_read.getnchannels () Returns number of audio channels (‘1’ for mono, ‘2’ for stereo). -- Method: Wave_read.getsampwidth () Returns sample width in bytes. -- Method: Wave_read.getframerate () Returns sampling frequency. -- Method: Wave_read.getnframes () Returns number of audio frames. -- Method: Wave_read.getcomptype () Returns compression type (‘'NONE'’ is the only supported type). -- Method: Wave_read.getcompname () Human-readable version of *note getcomptype(): 2cfa. Usually ‘'not compressed'’ parallels ‘'NONE'’. -- Method: Wave_read.getparams () Returns a *note namedtuple(): 1b7. ‘(nchannels, sampwidth, framerate, nframes, comptype, compname)’, equivalent to output of the ‘get*()’ methods. -- Method: Wave_read.readframes (n) Reads and returns at most `n' frames of audio, as a *note bytes: 331. object. -- Method: Wave_read.rewind () Rewind the file pointer to the beginning of the audio stream. The following two methods are defined for compatibility with the *note aifc: 5. module, and don’t do anything interesting. -- Method: Wave_read.getmarkers () Returns ‘None’. -- Method: Wave_read.getmark (id) Raise an error. The following two methods define a term “position” which is compatible between them, and is otherwise implementation dependent. -- Method: Wave_read.setpos (pos) Set the file pointer to the specified position. -- Method: Wave_read.tell () Return current file pointer position.  File: python.info, Node: Wave_write Objects, Prev: Wave_read Objects, Up: wave — Read and write WAV files 5.22.4.2 Wave_write Objects ........................... For seekable output streams, the ‘wave’ header will automatically be updated to reflect the number of frames actually written. For unseekable streams, the `nframes' value must be accurate when the first frame data is written. An accurate `nframes' value can be achieved either by calling *note setnframes(): 2d04. or *note setparams(): 2d05. with the number of frames that will be written before *note close(): 2cf2. is called and then using *note writeframesraw(): 90c. to write the frame data, or by calling *note writeframes(): 90d. with all of the frame data to be written. In the latter case *note writeframes(): 90d. will calculate the number of frames in the data and set `nframes' accordingly before writing the frame data. Wave_write objects, as returned by *note open(): 476, have the following methods: Changed in version 3.4: Added support for unseekable files. -- Method: Wave_write.close () Make sure `nframes' is correct, and close the file if it was opened by *note wave: 127. This method is called upon object collection. It will raise an exception if the output stream is not seekable and `nframes' does not match the number of frames actually written. -- Method: Wave_write.setnchannels (n) Set the number of channels. -- Method: Wave_write.setsampwidth (n) Set the sample width to `n' bytes. -- Method: Wave_write.setframerate (n) Set the frame rate to `n'. Changed in version 3.2: A non-integral input to this method is rounded to the nearest integer. -- Method: Wave_write.setnframes (n) Set the number of frames to `n'. This will be changed later if the number of frames actually written is different (this update attempt will raise an error if the output stream is not seekable). -- Method: Wave_write.setcomptype (type, name) Set the compression type and description. At the moment, only compression type ‘NONE’ is supported, meaning no compression. -- Method: Wave_write.setparams (tuple) The `tuple' should be ‘(nchannels, sampwidth, framerate, nframes, comptype, compname)’, with values valid for the ‘set*()’ methods. Sets all parameters. -- Method: Wave_write.tell () Return current position in the file, with the same disclaimer for the *note Wave_read.tell(): 2d02. and *note Wave_read.setpos(): 2d01. methods. -- Method: Wave_write.writeframesraw (data) Write audio frames, without correcting `nframes'. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. -- Method: Wave_write.writeframes (data) Write audio frames and make sure `nframes' is correct. It will raise an error if the output stream is not seekable and the total number of frames that have been written after `data' has been written does not match the previously set value for `nframes'. Changed in version 3.4: Any *note bytes-like object: 5e8. is now accepted. Note that it is invalid to set any parameters after calling ‘writeframes()’ or ‘writeframesraw()’, and any attempt to do so will raise *note wave.Error: 2cf3.  File: python.info, Node: chunk — Read IFF chunked data, Next: colorsys — Conversions between color systems, Prev: wave — Read and write WAV files, Up: Multimedia Services 5.22.5 ‘chunk’ — Read IFF chunked data -------------------------------------- `Source code:' Lib/chunk.py(1) __________________________________________________________________ This module provides an interface for reading files that use EA IFF 85 chunks. (2) This format is used in at least the Audio Interchange File Format (AIFF/AIFF-C) and the Real Media File Format (RMFF). The WAVE audio file format is closely related and can also be read using this module. A chunk has the following structure: Offset Length Contents --------------------------------------------------------------- 0 4 Chunk ID 4 4 Size of chunk in big-endian byte order, not including the header 8 `n' Data bytes, where `n' is the size given in the preceding field 8 + `n' 0 or 1 Pad byte needed if `n' is odd and chunk alignment is used The ID is a 4-byte string which identifies the type of chunk. The size field (a 32-bit value, encoded using big-endian byte order) gives the size of the chunk data, not including the 8-byte header. Usually an IFF-type file consists of one or more chunks. The proposed usage of the *note Chunk: 2d0d. class defined here is to instantiate an instance at the start of each chunk and read from the instance until it reaches the end, after which a new instance can be instantiated. At the end of the file, creating a new instance will fail with an *note EOFError: c6c. exception. -- Class: chunk.Chunk (file, align=True, bigendian=True, inclheader=False) Class which represents a chunk. The `file' argument is expected to be a file-like object. An instance of this class is specifically allowed. The only method that is needed is ‘read()’. If the methods *note seek(): 1a62. and *note tell(): 1a63. are present and don’t raise an exception, they are also used. If these methods are present and raise an exception, they are expected to not have altered the object. If the optional argument `align' is true, chunks are assumed to be aligned on 2-byte boundaries. If `align' is false, no alignment is assumed. The default value is true. If the optional argument `bigendian' is false, the chunk size is assumed to be in little-endian order. This is needed for WAVE audio files. The default value is true. If the optional argument `inclheader' is true, the size given in the chunk header includes the size of the header. The default value is false. A *note Chunk: 2d0d. object supports the following methods: -- Method: getname () Returns the name (ID) of the chunk. This is the first 4 bytes of the chunk. -- Method: getsize () Returns the size of the chunk. -- Method: close () Close and skip to the end of the chunk. This does not close the underlying file. The remaining methods will raise *note OSError: 1d3. if called after the *note close(): 2d10. method has been called. Before Python 3.3, they used to raise *note IOError: 992, now an alias of *note OSError: 1d3. -- Method: isatty () Returns ‘False’. -- Method: seek (pos, whence=0) Set the chunk’s current position. The `whence' argument is optional and defaults to ‘0’ (absolute file positioning); other values are ‘1’ (seek relative to the current position) and ‘2’ (seek relative to the file’s end). There is no return value. If the underlying file does not allow seek, only forward seeks are allowed. -- Method: tell () Return the current position into the chunk. -- Method: read (size=-1) Read at most `size' bytes from the chunk (less if the read hits the end of the chunk before obtaining `size' bytes). If the `size' argument is negative or omitted, read all data until the end of the chunk. An empty bytes object is returned when the end of the chunk is encountered immediately. -- Method: skip () Skip to the end of the chunk. All further calls to *note read(): 2d14. for the chunk will return ‘b''’. If you are not interested in the contents of the chunk, this method should be called so that the file points to the start of the next chunk. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/chunk.py (2) (1) “EA IFF 85” Standard for Interchange Format Files, Jerry Morrison, Electronic Arts, January 1985.  File: python.info, Node: colorsys — Conversions between color systems, Next: imghdr — Determine the type of an image, Prev: chunk — Read IFF chunked data, Up: Multimedia Services 5.22.6 ‘colorsys’ — Conversions between color systems ----------------------------------------------------- `Source code:' Lib/colorsys.py(1) __________________________________________________________________ The *note colorsys: 20. module defines bidirectional conversions of color values between colors expressed in the RGB (Red Green Blue) color space used in computer monitors and three other coordinate systems: YIQ, HLS (Hue Lightness Saturation) and HSV (Hue Saturation Value). Coordinates in all of these color spaces are floating point values. In the YIQ space, the Y coordinate is between 0 and 1, but the I and Q coordinates can be positive or negative. In all other spaces, the coordinates are all between 0 and 1. See also ........ More information about color spaces can be found at ‘http://poynton.ca/ColorFAQ.html’ and ‘https://www.cambridgeincolour.com/tutorials/color-spaces.htm’. The *note colorsys: 20. module defines the following functions: -- Function: colorsys.rgb_to_yiq (r, g, b) Convert the color from RGB coordinates to YIQ coordinates. -- Function: colorsys.yiq_to_rgb (y, i, q) Convert the color from YIQ coordinates to RGB coordinates. -- Function: colorsys.rgb_to_hls (r, g, b) Convert the color from RGB coordinates to HLS coordinates. -- Function: colorsys.hls_to_rgb (h, l, s) Convert the color from HLS coordinates to RGB coordinates. -- Function: colorsys.rgb_to_hsv (r, g, b) Convert the color from RGB coordinates to HSV coordinates. -- Function: colorsys.hsv_to_rgb (h, s, v) Convert the color from HSV coordinates to RGB coordinates. Example: >>> import colorsys >>> colorsys.rgb_to_hsv(0.2, 0.4, 0.4) (0.5, 0.5, 0.4) >>> colorsys.hsv_to_rgb(0.5, 0.5, 0.4) (0.2, 0.4, 0.4) ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/colorsys.py  File: python.info, Node: imghdr — Determine the type of an image, Next: sndhdr — Determine type of sound file, Prev: colorsys — Conversions between color systems, Up: Multimedia Services 5.22.7 ‘imghdr’ — Determine the type of an image ------------------------------------------------ `Source code:' Lib/imghdr.py(1) __________________________________________________________________ The *note imghdr: 99. module determines the type of image contained in a file or byte stream. The *note imghdr: 99. module defines the following function: -- Function: imghdr.what (filename, h=None) Tests the image data contained in the file named by `filename', and returns a string describing the image type. If optional `h' is provided, the `filename' is ignored and `h' is assumed to contain the byte stream to test. Changed in version 3.6: Accepts a *note path-like object: 36a. The following image types are recognized, as listed below with the return value from *note what(): 6ed.: Value Image format --------------------------------------------------------- ‘'rgb'’ SGI ImgLib Files ‘'gif'’ GIF 87a and 89a Files ‘'pbm'’ Portable Bitmap Files ‘'pgm'’ Portable Graymap Files ‘'ppm'’ Portable Pixmap Files ‘'tiff'’ TIFF Files ‘'rast'’ Sun Raster Files ‘'xbm'’ X Bitmap Files ‘'jpeg'’ JPEG data in JFIF or Exif formats ‘'bmp'’ BMP files ‘'png'’ Portable Network Graphics ‘'webp'’ WebP files ‘'exr'’ OpenEXR Files New in version 3.5: The `exr' and `webp' formats were added. You can extend the list of file types *note imghdr: 99. can recognize by appending to this variable: -- Data: imghdr.tests A list of functions performing the individual tests. Each function takes two arguments: the byte-stream and an open file-like object. When *note what(): 6ed. is called with a byte-stream, the file-like object will be ‘None’. The test function should return a string describing the image type if the test succeeded, or ‘None’ if it failed. Example: >>> import imghdr >>> imghdr.what('bass.gif') 'gif' ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/imghdr.py  File: python.info, Node: sndhdr — Determine type of sound file, Next: ossaudiodev — Access to OSS-compatible audio devices, Prev: imghdr — Determine the type of an image, Up: Multimedia Services 5.22.8 ‘sndhdr’ — Determine type of sound file ---------------------------------------------- `Source code:' Lib/sndhdr.py(1) __________________________________________________________________ The *note sndhdr: ee. provides utility functions which attempt to determine the type of sound data which is in a file. When these functions are able to determine what type of sound data is stored in a file, they return a *note namedtuple(): 1b7, containing five attributes: (‘filetype’, ‘framerate’, ‘nchannels’, ‘nframes’, ‘sampwidth’). The value for `type' indicates the data type and will be one of the strings ‘'aifc'’, ‘'aiff'’, ‘'au'’, ‘'hcom'’, ‘'sndr'’, ‘'sndt'’, ‘'voc'’, ‘'wav'’, ‘'8svx'’, ‘'sb'’, ‘'ub'’, or ‘'ul'’. The `sampling_rate' will be either the actual value or ‘0’ if unknown or difficult to decode. Similarly, `channels' will be either the number of channels or ‘0’ if it cannot be determined or if the value is difficult to decode. The value for `frames' will be either the number of frames or ‘-1’. The last item in the tuple, `bits_per_sample', will either be the sample size in bits or ‘'A'’ for A-LAW or ‘'U'’ for u-LAW. -- Function: sndhdr.what (filename) Determines the type of sound data stored in the file `filename' using *note whathdr(): 748. If it succeeds, returns a namedtuple as described above, otherwise ‘None’ is returned. Changed in version 3.5: Result changed from a tuple to a namedtuple. -- Function: sndhdr.whathdr (filename) Determines the type of sound data stored in a file based on the file header. The name of the file is given by `filename'. This function returns a namedtuple as described above on success, or ‘None’. Changed in version 3.5: Result changed from a tuple to a namedtuple. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/sndhdr.py  File: python.info, Node: ossaudiodev — Access to OSS-compatible audio devices, Prev: sndhdr — Determine type of sound file, Up: Multimedia Services 5.22.9 ‘ossaudiodev’ — Access to OSS-compatible audio devices ------------------------------------------------------------- __________________________________________________________________ This module allows you to access the OSS (Open Sound System) audio interface. OSS is available for a wide range of open-source and commercial Unices, and is the standard audio interface for Linux and recent versions of FreeBSD. Changed in version 3.3: Operations in this module now raise *note OSError: 1d3. where *note IOError: 992. was raised. See also ........ Open Sound System Programmer’s Guide(1) the official documentation for the OSS C API The module defines a large number of constants supplied by the OSS device driver; see ‘<sys/soundcard.h>’ on either Linux or FreeBSD for a listing. *note ossaudiodev: c6. defines the following variables and functions: -- Exception: ossaudiodev.OSSAudioError This exception is raised on certain errors. The argument is a string describing what went wrong. (If *note ossaudiodev: c6. receives an error from a system call such as ‘open()’, ‘write()’, or ‘ioctl()’, it raises *note OSError: 1d3. Errors detected directly by *note ossaudiodev: c6. result in *note OSSAudioError: 2d25.) (For backwards compatibility, the exception class is also available as ‘ossaudiodev.error’.) -- Function: ossaudiodev.open (mode) -- Function: ossaudiodev.open (device, mode) Open an audio device and return an OSS audio device object. This object supports many file-like methods, such as ‘read()’, ‘write()’, and ‘fileno()’ (although there are subtle differences between conventional Unix read/write semantics and those of OSS audio devices). It also supports a number of audio-specific methods; see below for the complete list of methods. `device' is the audio device filename to use. If it is not specified, this module first looks in the environment variable ‘AUDIODEV’ for a device to use. If not found, it falls back to ‘/dev/dsp’. `mode' is one of ‘'r'’ for read-only (record) access, ‘'w'’ for write-only (playback) access and ‘'rw'’ for both. Since many sound cards only allow one process to have the recorder or player open at a time, it is a good idea to open the device only for the activity needed. Further, some sound cards are half-duplex: they can be opened for reading or writing, but not both at once. Note the unusual calling syntax: the `first' argument is optional, and the second is required. This is a historical artifact for compatibility with the older ‘linuxaudiodev’ module which *note ossaudiodev: c6. supersedes. -- Function: ossaudiodev.openmixer ([device]) Open a mixer device and return an OSS mixer device object. `device' is the mixer device filename to use. If it is not specified, this module first looks in the environment variable ‘MIXERDEV’ for a device to use. If not found, it falls back to ‘/dev/mixer’. * Menu: * Audio Device Objects:: * Mixer Device Objects:: ---------- Footnotes ---------- (1) http://www.opensound.com/pguide/oss.pdf  File: python.info, Node: Audio Device Objects, Next: Mixer Device Objects, Up: ossaudiodev — Access to OSS-compatible audio devices 5.22.9.1 Audio Device Objects ............................. Before you can write to or read from an audio device, you must call three methods in the correct order: 1. ‘setfmt()’ to set the output format 2. ‘channels()’ to set the number of channels 3. ‘speed()’ to set the sample rate Alternately, you can use the ‘setparameters()’ method to set all three audio parameters at once. This is more convenient, but may not be as flexible in all cases. The audio device objects returned by *note open(): 2d26. define the following methods and (read-only) attributes: -- Method: oss_audio_device.close () Explicitly close the audio device. When you are done writing to or reading from an audio device, you should explicitly close it. A closed device cannot be used again. -- Method: oss_audio_device.fileno () Return the file descriptor associated with the device. -- Method: oss_audio_device.read (size) Read `size' bytes from the audio input and return them as a Python string. Unlike most Unix device drivers, OSS audio devices in blocking mode (the default) will block *note read(): 2d2c. until the entire requested amount of data is available. -- Method: oss_audio_device.write (data) Write a *note bytes-like object: 5e8. `data' to the audio device and return the number of bytes written. If the audio device is in blocking mode (the default), the entire data is always written (again, this is different from usual Unix device semantics). If the device is in non-blocking mode, some data may not be written—see *note writeall(): 2d2e. Changed in version 3.5: Writable *note bytes-like object: 5e8. is now accepted. -- Method: oss_audio_device.writeall (data) Write a *note bytes-like object: 5e8. `data' to the audio device: waits until the audio device is able to accept data, writes as much data as it will accept, and repeats until `data' has been completely written. If the device is in blocking mode (the default), this has the same effect as *note write(): 2d2d.; *note writeall(): 2d2e. is only useful in non-blocking mode. Has no return value, since the amount of data written is always equal to the amount of data supplied. Changed in version 3.5: Writable *note bytes-like object: 5e8. is now accepted. Changed in version 3.2: Audio device objects also support the context management protocol, i.e. they can be used in a *note with: 6e9. statement. The following methods each map to exactly one ‘ioctl()’ system call. The correspondence is obvious: for example, ‘setfmt()’ corresponds to the ‘SNDCTL_DSP_SETFMT’ ioctl, and ‘sync()’ to ‘SNDCTL_DSP_SYNC’ (this can be useful when consulting the OSS documentation). If the underlying ‘ioctl()’ fails, they all raise *note OSError: 1d3. -- Method: oss_audio_device.nonblock () Put the device into non-blocking mode. Once in non-blocking mode, there is no way to return it to blocking mode. -- Method: oss_audio_device.getfmts () Return a bitmask of the audio output formats supported by the soundcard. Some of the formats supported by OSS are: Format Description -------------------------------------------------------------------------------- ‘AFMT_MU_LAW’ a logarithmic encoding (used by Sun ‘.au’ files and ‘/dev/audio’) ‘AFMT_A_LAW’ a logarithmic encoding ‘AFMT_IMA_ADPCM’ a 4:1 compressed format defined by the Interactive Multimedia Association ‘AFMT_U8’ Unsigned, 8-bit audio ‘AFMT_S16_LE’ Signed, 16-bit audio, little-endian byte order (as used by Intel processors) ‘AFMT_S16_BE’ Signed, 16-bit audio, big-endian byte order (as used by 68k, PowerPC, Sparc) ‘AFMT_S8’ Signed, 8 bit audio ‘AFMT_U16_LE’ Unsigned, 16-bit little-endian audio ‘AFMT_U16_BE’ Unsigned, 16-bit big-endian audio Consult the OSS documentation for a full list of audio formats, and note that most devices support only a subset of these formats. Some older devices only support ‘AFMT_U8’; the most common format used today is ‘AFMT_S16_LE’. -- Method: oss_audio_device.setfmt (format) Try to set the current audio format to `format'—see *note getfmts(): 2d30. for a list. Returns the audio format that the device was set to, which may not be the requested format. May also be used to return the current audio format—do this by passing an “audio format” of ‘AFMT_QUERY’. -- Method: oss_audio_device.channels (nchannels) Set the number of output channels to `nchannels'. A value of 1 indicates monophonic sound, 2 stereophonic. Some devices may have more than 2 channels, and some high-end devices may not support mono. Returns the number of channels the device was set to. -- Method: oss_audio_device.speed (samplerate) Try to set the audio sampling rate to `samplerate' samples per second. Returns the rate actually set. Most sound devices don’t support arbitrary sampling rates. Common rates are: Rate Description ------------------------------------------------------------ 8000 default rate for ‘/dev/audio’ 11025 speech recording 22050 44100 CD quality audio (at 16 bits/sample and 2 channels) 96000 DVD quality audio (at 24 bits/sample) -- Method: oss_audio_device.sync () Wait until the sound device has played every byte in its buffer. (This happens implicitly when the device is closed.) The OSS documentation recommends closing and re-opening the device rather than using *note sync(): 2d34. -- Method: oss_audio_device.reset () Immediately stop playing or recording and return the device to a state where it can accept commands. The OSS documentation recommends closing and re-opening the device after calling *note reset(): 2d35. -- Method: oss_audio_device.post () Tell the driver that there is likely to be a pause in the output, making it possible for the device to handle the pause more intelligently. You might use this after playing a spot sound effect, before waiting for user input, or before doing disk I/O. The following convenience methods combine several ioctls, or one ioctl and some simple calculations. -- Method: oss_audio_device.setparameters (format, nchannels, samplerate[, strict=False]) Set the key audio sampling parameters—sample format, number of channels, and sampling rate—in one method call. `format', `nchannels', and `samplerate' should be as specified in the *note setfmt(): 2d31, *note channels(): 2d32, and *note speed(): 2d33. methods. If `strict' is true, *note setparameters(): 2d37. checks to see if each parameter was actually set to the requested value, and raises *note OSSAudioError: 2d25. if not. Returns a tuple (`format', `nchannels', `samplerate') indicating the parameter values that were actually set by the device driver (i.e., the same as the return values of *note setfmt(): 2d31, *note channels(): 2d32, and *note speed(): 2d33.). For example, (fmt, channels, rate) = dsp.setparameters(fmt, channels, rate) is equivalent to fmt = dsp.setfmt(fmt) channels = dsp.channels(channels) rate = dsp.rate(rate) -- Method: oss_audio_device.bufsize () Returns the size of the hardware buffer, in samples. -- Method: oss_audio_device.obufcount () Returns the number of samples that are in the hardware buffer yet to be played. -- Method: oss_audio_device.obuffree () Returns the number of samples that could be queued into the hardware buffer to be played without blocking. Audio device objects also support several read-only attributes: -- Attribute: oss_audio_device.closed Boolean indicating whether the device has been closed. -- Attribute: oss_audio_device.name String containing the name of the device file. -- Attribute: oss_audio_device.mode The I/O mode for the file, either ‘"r"’, ‘"rw"’, or ‘"w"’.  File: python.info, Node: Mixer Device Objects, Prev: Audio Device Objects, Up: ossaudiodev — Access to OSS-compatible audio devices 5.22.9.2 Mixer Device Objects ............................. The mixer object provides two file-like methods: -- Method: oss_mixer_device.close () This method closes the open mixer device file. Any further attempts to use the mixer after this file is closed will raise an *note OSError: 1d3. -- Method: oss_mixer_device.fileno () Returns the file handle number of the open mixer device file. Changed in version 3.2: Mixer objects also support the context management protocol. The remaining methods are specific to audio mixing: -- Method: oss_mixer_device.controls () This method returns a bitmask specifying the available mixer controls (“Control” being a specific mixable “channel”, such as ‘SOUND_MIXER_PCM’ or ‘SOUND_MIXER_SYNTH’). This bitmask indicates a subset of all available mixer controls—the ‘SOUND_MIXER_*’ constants defined at module level. To determine if, for example, the current mixer object supports a PCM mixer, use the following Python code: mixer=ossaudiodev.openmixer() if mixer.controls() & (1 << ossaudiodev.SOUND_MIXER_PCM): # PCM is supported ... code ... For most purposes, the ‘SOUND_MIXER_VOLUME’ (master volume) and ‘SOUND_MIXER_PCM’ controls should suffice—but code that uses the mixer should be flexible when it comes to choosing mixer controls. On the Gravis Ultrasound, for example, ‘SOUND_MIXER_VOLUME’ does not exist. -- Method: oss_mixer_device.stereocontrols () Returns a bitmask indicating stereo mixer controls. If a bit is set, the corresponding control is stereo; if it is unset, the control is either monophonic or not supported by the mixer (use in combination with *note controls(): 2d42. to determine which). See the code example for the *note controls(): 2d42. function for an example of getting data from a bitmask. -- Method: oss_mixer_device.reccontrols () Returns a bitmask specifying the mixer controls that may be used to record. See the code example for *note controls(): 2d42. for an example of reading from a bitmask. -- Method: oss_mixer_device.get (control) Returns the volume of a given mixer control. The returned volume is a 2-tuple ‘(left_volume,right_volume)’. Volumes are specified as numbers from 0 (silent) to 100 (full volume). If the control is monophonic, a 2-tuple is still returned, but both volumes are the same. Raises *note OSSAudioError: 2d25. if an invalid control is specified, or *note OSError: 1d3. if an unsupported control is specified. -- Method: oss_mixer_device.set (control, (left, right)) Sets the volume for a given mixer control to ‘(left,right)’. ‘left’ and ‘right’ must be ints and between 0 (silent) and 100 (full volume). On success, the new volume is returned as a 2-tuple. Note that this may not be exactly the same as the volume specified, because of the limited resolution of some soundcard’s mixers. Raises *note OSSAudioError: 2d25. if an invalid mixer control was specified, or if the specified volumes were out-of-range. -- Method: oss_mixer_device.get_recsrc () This method returns a bitmask indicating which control(s) are currently being used as a recording source. -- Method: oss_mixer_device.set_recsrc (bitmask) Call this function to specify a recording source. Returns a bitmask indicating the new recording source (or sources) if successful; raises *note OSError: 1d3. if an invalid source was specified. To set the current recording source to the microphone input: mixer.setrecsrc (1 << ossaudiodev.SOUND_MIXER_MIC)  File: python.info, Node: Internationalization, Next: Program Frameworks, Prev: Multimedia Services, Up: The Python Standard Library 5.23 Internationalization ========================= The modules described in this chapter help you write software that is independent of language and locale by providing mechanisms for selecting a language to be used in program messages or by tailoring output to match local conventions. The list of modules described in this chapter is: * Menu: * gettext — Multilingual internationalization services:: * locale — Internationalization services::  File: python.info, Node: gettext — Multilingual internationalization services, Next: locale — Internationalization services, Up: Internationalization 5.23.1 ‘gettext’ — Multilingual internationalization services ------------------------------------------------------------- `Source code:' Lib/gettext.py(1) __________________________________________________________________ The *note gettext: 89. module provides internationalization (I18N) and localization (L10N) services for your Python modules and applications. It supports both the GNU ‘gettext’ message catalog API and a higher level, class-based API that may be more appropriate for Python files. The interface described below allows you to write your module and application messages in one natural language, and provide a catalog of translated messages for running under different natural languages. Some hints on localizing your Python modules and applications are also given. * Menu: * GNU gettext API:: * Class-based API:: * Internationalizing your programs and modules:: * Acknowledgements: Acknowledgements<9>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/gettext.py  File: python.info, Node: GNU gettext API, Next: Class-based API, Up: gettext — Multilingual internationalization services 5.23.1.1 GNU ‘gettext’ API .......................... The *note gettext: 89. module defines the following API, which is very similar to the GNU ‘gettext’ API. If you use this API you will affect the translation of your entire application globally. Often this is what you want if your application is monolingual, with the choice of language dependent on the locale of your user. If you are localizing a Python module, or if your application needs to switch languages on the fly, you probably want to use the class-based API instead. -- Function: gettext.bindtextdomain (domain, localedir=None) Bind the `domain' to the locale directory `localedir'. More concretely, *note gettext: 89. will look for binary ‘.mo’ files for the given domain using the path (on Unix): ‘`localedir'/`language'/LC_MESSAGES/`domain'.mo’, where `language' is searched for in the environment variables ‘LANGUAGE’, ‘LC_ALL’, ‘LC_MESSAGES’, and ‘LANG’ respectively. If `localedir' is omitted or ‘None’, then the current binding for `domain' is returned. (1) -- Function: gettext.bind_textdomain_codeset (domain, codeset=None) Bind the `domain' to `codeset', changing the encoding of byte strings returned by the *note lgettext(): 293, *note ldgettext(): 294, *note lngettext(): 295. and *note ldngettext(): 296. functions. If `codeset' is omitted, then the current binding is returned. Deprecated since version 3.8, will be removed in version 3.10. -- Function: gettext.textdomain (domain=None) Change or query the current global domain. If `domain' is ‘None’, then the current global domain is returned, otherwise the global domain is set to `domain', which is returned. -- Function: gettext.gettext (message) Return the localized translation of `message', based on the current global domain, language, and locale directory. This function is usually aliased as ‘_()’ in the local namespace (see examples below). -- Function: gettext.dgettext (domain, message) Like *note gettext(): dcd, but look the message up in the specified `domain'. -- Function: gettext.ngettext (singular, plural, n) Like *note gettext(): dcd, but consider plural forms. If a translation is found, apply the plural formula to `n', and return the resulting message (some languages have more than two plural forms). If no translation is found, return `singular' if `n' is 1; return `plural' otherwise. The Plural formula is taken from the catalog header. It is a C or Python expression that has a free variable `n'; the expression evaluates to the index of the plural in the catalog. See the GNU gettext documentation(2) for the precise syntax to be used in ‘.po’ files and the formulas for a variety of languages. -- Function: gettext.dngettext (domain, singular, plural, n) Like *note ngettext(): 2d53, but look the message up in the specified `domain'. -- Function: gettext.pgettext (context, message) -- Function: gettext.dpgettext (domain, context, message) -- Function: gettext.npgettext (context, singular, plural, n) -- Function: gettext.dnpgettext (domain, context, singular, plural, n) Similar to the corresponding functions without the ‘p’ in the prefix (that is, *note gettext(): 89, *note dgettext(): 2d52, *note ngettext(): 2d53, *note dngettext(): 2d54.), but the translation is restricted to the given message `context'. New in version 3.8. -- Function: gettext.lgettext (message) -- Function: gettext.ldgettext (domain, message) -- Function: gettext.lngettext (singular, plural, n) -- Function: gettext.ldngettext (domain, singular, plural, n) Equivalent to the corresponding functions without the ‘l’ prefix (*note gettext(): dcd, *note dgettext(): 2d52, *note ngettext(): 2d53. and *note dngettext(): 2d54.), but the translation is returned as a byte string encoded in the preferred system encoding if no other encoding was explicitly set with *note bind_textdomain_codeset(): 297. Warning: These functions should be avoided in Python 3, because they return encoded bytes. It’s much better to use alternatives which return Unicode strings instead, since most Python applications will want to manipulate human readable text as strings instead of bytes. Further, it’s possible that you may get unexpected Unicode-related exceptions if there are encoding problems with the translated strings. Deprecated since version 3.8, will be removed in version 3.10. Note that GNU ‘gettext’ also defines a ‘dcgettext()’ method, but this was deemed not useful and so it is currently unimplemented. Here’s an example of typical usage for this API: import gettext gettext.bindtextdomain('myapplication', '/path/to/my/language/directory') gettext.textdomain('myapplication') _ = gettext.gettext # ... print(_('This is a translatable string.')) ---------- Footnotes ---------- (1) (1) The default locale directory is system dependent; for example, on RedHat Linux it is ‘/usr/share/locale’, but on Solaris it is ‘/usr/lib/locale’. The *note gettext: 89. module does not try to support these system dependent defaults; instead its default is ‘`sys.base_prefix'/share/locale’ (see *note sys.base_prefix: 2d50.). For this reason, it is always best to call *note bindtextdomain(): 2d4f. with an explicit absolute path at the start of your application. (2) https://www.gnu.org/software/gettext/manual/gettext.html  File: python.info, Node: Class-based API, Next: Internationalizing your programs and modules, Prev: GNU gettext API, Up: gettext — Multilingual internationalization services 5.23.1.2 Class-based API ........................ The class-based API of the *note gettext: 89. module gives you more flexibility and greater convenience than the GNU ‘gettext’ API. It is the recommended way of localizing your Python applications and modules. ‘gettext’ defines a *note GNUTranslations: 2d59. class which implements the parsing of GNU ‘.mo’ format files, and has methods for returning strings. Instances of this class can also install themselves in the built-in namespace as the function ‘_()’. -- Function: gettext.find (domain, localedir=None, languages=None, all=False) This function implements the standard ‘.mo’ file search algorithm. It takes a `domain', identical to what *note textdomain(): 2d51. takes. Optional `localedir' is as in *note bindtextdomain(): 2d4f. Optional `languages' is a list of strings, where each string is a language code. If `localedir' is not given, then the default system locale directory is used. (1) If `languages' is not given, then the following environment variables are searched: ‘LANGUAGE’, ‘LC_ALL’, ‘LC_MESSAGES’, and ‘LANG’. The first one returning a non-empty value is used for the `languages' variable. The environment variables should contain a colon separated list of languages, which will be split on the colon to produce the expected list of language code strings. *note find(): 2d5a. then expands and normalizes the languages, and then iterates through them, searching for an existing file built of these components: ‘`localedir'/`language'/LC_MESSAGES/`domain'.mo’ The first such file name that exists is returned by *note find(): 2d5a. If no such file is found, then ‘None’ is returned. If `all' is given, it returns a list of all file names, in the order in which they appear in the languages list or the environment variables. -- Function: gettext.translation (domain, localedir=None, languages=None, class_=None, fallback=False, codeset=None) Return a ‘*Translations’ instance based on the `domain', `localedir', and `languages', which are first passed to *note find(): 2d5a. to get a list of the associated ‘.mo’ file paths. Instances with identical ‘.mo’ file names are cached. The actual class instantiated is `class_' if provided, otherwise *note GNUTranslations: 2d59. The class’s constructor must take a single *note file object: b42. argument. If provided, `codeset' will change the charset used to encode translated strings in the *note lgettext(): 2d5b. and *note lngettext(): 2d5c. methods. If multiple files are found, later files are used as fallbacks for earlier ones. To allow setting the fallback, *note copy.copy(): 3cb. is used to clone each translation object from the cache; the actual instance data is still shared with the cache. If no ‘.mo’ file is found, this function raises *note OSError: 1d3. if `fallback' is false (which is the default), and returns a *note NullTranslations: 2d5d. instance if `fallback' is true. Changed in version 3.3: *note IOError: 992. used to be raised instead of *note OSError: 1d3. Deprecated since version 3.8, will be removed in version 3.10: The `codeset' parameter. -- Function: gettext.install (domain, localedir=None, codeset=None, names=None) This installs the function ‘_()’ in Python’s builtins namespace, based on `domain', `localedir', and `codeset' which are passed to the function *note translation(): 29a. For the `names' parameter, please see the description of the translation object’s *note install(): 2d5e. method. As seen below, you usually mark the strings in your application that are candidates for translation, by wrapping them in a call to the ‘_()’ function, like this: print(_('This string will be translated.')) For convenience, you want the ‘_()’ function to be installed in Python’s builtins namespace, so it is easily accessible in all modules of your application. Deprecated since version 3.8, will be removed in version 3.10: The `codeset' parameter. * Menu: * The NullTranslations class:: * The GNUTranslations class:: * Solaris message catalog support:: * The Catalog constructor:: ---------- Footnotes ---------- (1) (2) See the footnote for *note bindtextdomain(): 2d4f. above.  File: python.info, Node: The NullTranslations class, Next: The GNUTranslations class, Up: Class-based API 5.23.1.3 The ‘NullTranslations’ class ..................................... Translation classes are what actually implement the translation of original source file message strings to translated message strings. The base class used by all translation classes is *note NullTranslations: 2d5d.; this provides the basic interface you can use to write your own specialized translation classes. Here are the methods of ‘NullTranslations’: -- Class: gettext.NullTranslations (fp=None) Takes an optional *note file object: b42. `fp', which is ignored by the base class. Initializes “protected” instance variables `_info' and `_charset' which are set by derived classes, as well as `_fallback', which is set through *note add_fallback(): 2d60. It then calls ‘self._parse(fp)’ if `fp' is not ‘None’. -- Method: _parse (fp) No-op in the base class, this method takes file object `fp', and reads the data from the file, initializing its message catalog. If you have an unsupported message catalog file format, you should override this method to parse your format. -- Method: add_fallback (fallback) Add `fallback' as the fallback object for the current translation object. A translation object should consult the fallback if it cannot provide a translation for a given message. -- Method: gettext (message) If a fallback has been set, forward ‘gettext()’ to the fallback. Otherwise, return `message'. Overridden in derived classes. -- Method: ngettext (singular, plural, n) If a fallback has been set, forward ‘ngettext()’ to the fallback. Otherwise, return `singular' if `n' is 1; return `plural' otherwise. Overridden in derived classes. -- Method: pgettext (context, message) If a fallback has been set, forward *note pgettext(): 1cf. to the fallback. Otherwise, return the translated message. Overridden in derived classes. New in version 3.8. -- Method: npgettext (context, singular, plural, n) If a fallback has been set, forward *note npgettext(): 2d56. to the fallback. Otherwise, return the translated message. Overridden in derived classes. New in version 3.8. -- Method: lgettext (message) -- Method: lngettext (singular, plural, n) Equivalent to *note gettext(): 2d62. and *note ngettext(): 2d63, but the translation is returned as a byte string encoded in the preferred system encoding if no encoding was explicitly set with *note set_output_charset(): 299. Overridden in derived classes. Warning: These methods should be avoided in Python 3. See the warning for the *note lgettext(): 293. function. Deprecated since version 3.8, will be removed in version 3.10. -- Method: info () Return the “protected” ‘_info’ variable, a dictionary containing the metadata found in the message catalog file. -- Method: charset () Return the encoding of the message catalog file. -- Method: output_charset () Return the encoding used to return translated messages in *note lgettext(): 2d5b. and *note lngettext(): 2d5c. Deprecated since version 3.8, will be removed in version 3.10. -- Method: set_output_charset (charset) Change the encoding used to return translated messages. Deprecated since version 3.8, will be removed in version 3.10. -- Method: install (names=None) This method installs *note gettext(): 2d62. into the built-in namespace, binding it to ‘_’. If the `names' parameter is given, it must be a sequence containing the names of functions you want to install in the builtins namespace in addition to ‘_()’. Supported names are ‘'gettext'’, ‘'ngettext'’, ‘'pgettext'’, ‘'npgettext'’, ‘'lgettext'’, and ‘'lngettext'’. Note that this is only one way, albeit the most convenient way, to make the ‘_()’ function available to your application. Because it affects the entire application globally, and specifically the built-in namespace, localized modules should never install ‘_()’. Instead, they should use this code to make ‘_()’ available to their module: import gettext t = gettext.translation('mymodule', ...) _ = t.gettext This puts ‘_()’ only in the module’s global namespace and so only affects calls within this module. Changed in version 3.8: Added ‘'pgettext'’ and ‘'npgettext'’.  File: python.info, Node: The GNUTranslations class, Next: Solaris message catalog support, Prev: The NullTranslations class, Up: Class-based API 5.23.1.4 The ‘GNUTranslations’ class .................................... The *note gettext: 89. module provides one additional class derived from *note NullTranslations: 2d5d.: *note GNUTranslations: 2d59. This class overrides ‘_parse()’ to enable reading GNU ‘gettext’ format ‘.mo’ files in both big-endian and little-endian format. *note GNUTranslations: 2d59. parses optional metadata out of the translation catalog. It is convention with GNU ‘gettext’ to include metadata as the translation for the empty string. This metadata is in RFC 822(1)-style ‘key: value’ pairs, and should contain the ‘Project-Id-Version’ key. If the key ‘Content-Type’ is found, then the ‘charset’ property is used to initialize the “protected” ‘_charset’ instance variable, defaulting to ‘None’ if not found. If the charset encoding is specified, then all message ids and message strings read from the catalog are converted to Unicode using this encoding, else ASCII is assumed. Since message ids are read as Unicode strings too, all ‘*gettext()’ methods will assume message ids as Unicode strings, not byte strings. The entire set of key/value pairs are placed into a dictionary and set as the “protected” ‘_info’ instance variable. If the ‘.mo’ file’s magic number is invalid, the major version number is unexpected, or if other problems occur while reading the file, instantiating a *note GNUTranslations: 2d59. class can raise *note OSError: 1d3. -- Class: gettext.GNUTranslations The following methods are overridden from the base class implementation: -- Method: gettext (message) Look up the `message' id in the catalog and return the corresponding message string, as a Unicode string. If there is no entry in the catalog for the `message' id, and a fallback has been set, the look up is forwarded to the fallback’s *note gettext(): 2d62. method. Otherwise, the `message' id is returned. -- Method: ngettext (singular, plural, n) Do a plural-forms lookup of a message id. `singular' is used as the message id for purposes of lookup in the catalog, while `n' is used to determine which plural form to use. The returned message string is a Unicode string. If the message id is not found in the catalog, and a fallback is specified, the request is forwarded to the fallback’s *note ngettext(): 2d63. method. Otherwise, when `n' is 1 `singular' is returned, and `plural' is returned in all other cases. Here is an example: n = len(os.listdir('.')) cat = GNUTranslations(somefile) message = cat.ngettext( 'There is %(num)d file in this directory', 'There are %(num)d files in this directory', n) % {'num': n} -- Method: pgettext (context, message) Look up the `context' and `message' id in the catalog and return the corresponding message string, as a Unicode string. If there is no entry in the catalog for the `message' id and `context', and a fallback has been set, the look up is forwarded to the fallback’s *note pgettext(): 1cf. method. Otherwise, the `message' id is returned. New in version 3.8. -- Method: npgettext (context, singular, plural, n) Do a plural-forms lookup of a message id. `singular' is used as the message id for purposes of lookup in the catalog, while `n' is used to determine which plural form to use. If the message id for `context' is not found in the catalog, and a fallback is specified, the request is forwarded to the fallback’s *note npgettext(): 2d56. method. Otherwise, when `n' is 1 `singular' is returned, and `plural' is returned in all other cases. New in version 3.8. -- Method: lgettext (message) -- Method: lngettext (singular, plural, n) Equivalent to *note gettext(): 2d69. and *note ngettext(): 2d6a, but the translation is returned as a byte string encoded in the preferred system encoding if no encoding was explicitly set with *note set_output_charset(): 299. Warning: These methods should be avoided in Python 3. See the warning for the *note lgettext(): 293. function. Deprecated since version 3.8, will be removed in version 3.10. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc822.html  File: python.info, Node: Solaris message catalog support, Next: The Catalog constructor, Prev: The GNUTranslations class, Up: Class-based API 5.23.1.5 Solaris message catalog support ........................................ The Solaris operating system defines its own binary ‘.mo’ file format, but since no documentation can be found on this format, it is not supported at this time.  File: python.info, Node: The Catalog constructor, Prev: Solaris message catalog support, Up: Class-based API 5.23.1.6 The Catalog constructor ................................ GNOME uses a version of the *note gettext: 89. module by James Henstridge, but this version has a slightly different API. Its documented usage was: import gettext cat = gettext.Catalog(domain, localedir) _ = cat.gettext print(_('hello world')) For compatibility with this older module, the function ‘Catalog()’ is an alias for the *note translation(): 29a. function described above. One difference between this module and Henstridge’s: his catalog objects supported access through a mapping API, but this appears to be unused and so is not currently supported.  File: python.info, Node: Internationalizing your programs and modules, Next: Acknowledgements<9>, Prev: Class-based API, Up: gettext — Multilingual internationalization services 5.23.1.7 Internationalizing your programs and modules ..................................................... Internationalization (I18N) refers to the operation by which a program is made aware of multiple languages. Localization (L10N) refers to the adaptation of your program, once internationalized, to the local language and cultural habits. In order to provide multilingual messages for your Python programs, you need to take the following steps: 1. prepare your program or module by specially marking translatable strings 2. run a suite of tools over your marked files to generate raw messages catalogs 3. create language-specific translations of the message catalogs 4. use the *note gettext: 89. module so that message strings are properly translated In order to prepare your code for I18N, you need to look at all the strings in your files. Any string that needs to be translated should be marked by wrapping it in ‘_('...')’ — that is, a call to the function ‘_()’. For example: filename = 'mylog.txt' message = _('writing a log message') with open(filename, 'w') as fp: fp.write(message) In this example, the string ‘'writing a log message'’ is marked as a candidate for translation, while the strings ‘'mylog.txt'’ and ‘'w'’ are not. There are a few tools to extract the strings meant for translation. The original GNU ‘gettext’ only supported C or C++ source code but its extended version ‘xgettext’ scans code written in a number of languages, including Python, to find strings marked as translatable. Babel(1) is a Python internationalization library that includes a ‘pybabel’ script to extract and compile message catalogs. François Pinard’s program called ‘xpot’ does a similar job and is available as part of his po-utils package(2). (Python also includes pure-Python versions of these programs, called ‘pygettext.py’ and ‘msgfmt.py’; some Python distributions will install them for you. ‘pygettext.py’ is similar to ‘xgettext’, but only understands Python source code and cannot handle other programming languages such as C or C++. ‘pygettext.py’ supports a command-line interface similar to ‘xgettext’; for details on its use, run ‘pygettext.py --help’. ‘msgfmt.py’ is binary compatible with GNU ‘msgfmt’. With these two programs, you may not need the GNU ‘gettext’ package to internationalize your Python applications.) ‘xgettext’, ‘pygettext’, and similar tools generate ‘.po’ files that are message catalogs. They are structured human-readable files that contain every marked string in the source code, along with a placeholder for the translated versions of these strings. Copies of these ‘.po’ files are then handed over to the individual human translators who write translations for every supported natural language. They send back the completed language-specific versions as a ‘<language-name>.po’ file that’s compiled into a machine-readable ‘.mo’ binary catalog file using the ‘msgfmt’ program. The ‘.mo’ files are used by the *note gettext: 89. module for the actual translation processing at run-time. How you use the *note gettext: 89. module in your code depends on whether you are internationalizing a single module or your entire application. The next two sections will discuss each case. * Menu: * Localizing your module:: * Localizing your application:: * Changing languages on the fly:: * Deferred translations:: ---------- Footnotes ---------- (1) http://babel.pocoo.org/ (2) https://github.com/pinard/po-utils  File: python.info, Node: Localizing your module, Next: Localizing your application, Up: Internationalizing your programs and modules 5.23.1.8 Localizing your module ............................... If you are localizing your module, you must take care not to make global changes, e.g. to the built-in namespace. You should not use the GNU ‘gettext’ API but instead the class-based API. Let’s say your module is called “spam” and the module’s various natural language translation ‘.mo’ files reside in ‘/usr/share/locale’ in GNU ‘gettext’ format. Here’s what you would put at the top of your module: import gettext t = gettext.translation('spam', '/usr/share/locale') _ = t.gettext  File: python.info, Node: Localizing your application, Next: Changing languages on the fly, Prev: Localizing your module, Up: Internationalizing your programs and modules 5.23.1.9 Localizing your application .................................... If you are localizing your application, you can install the ‘_()’ function globally into the built-in namespace, usually in the main driver file of your application. This will let all your application-specific files just use ‘_('...')’ without having to explicitly install it in each file. In the simple case then, you need only add the following bit of code to the main driver file of your application: import gettext gettext.install('myapplication') If you need to set the locale directory, you can pass it into the *note install(): 29b. function: import gettext gettext.install('myapplication', '/usr/share/locale')  File: python.info, Node: Changing languages on the fly, Next: Deferred translations, Prev: Localizing your application, Up: Internationalizing your programs and modules 5.23.1.10 Changing languages on the fly ....................................... If your program needs to support many languages at the same time, you may want to create multiple translation instances and then switch between them explicitly, like so: import gettext lang1 = gettext.translation('myapplication', languages=['en']) lang2 = gettext.translation('myapplication', languages=['fr']) lang3 = gettext.translation('myapplication', languages=['de']) # start by using language1 lang1.install() # ... time goes by, user selects language 2 lang2.install() # ... more time goes by, user selects language 3 lang3.install()  File: python.info, Node: Deferred translations, Prev: Changing languages on the fly, Up: Internationalizing your programs and modules 5.23.1.11 Deferred translations ............................... In most coding situations, strings are translated where they are coded. Occasionally however, you need to mark strings for translation, but defer actual translation until later. A classic example is: animals = ['mollusk', 'albatross', 'rat', 'penguin', 'python', ] # ... for a in animals: print(a) Here, you want to mark the strings in the ‘animals’ list as being translatable, but you don’t actually want to translate them until they are printed. Here is one way you can handle this situation: def _(message): return message animals = [_('mollusk'), _('albatross'), _('rat'), _('penguin'), _('python'), ] del _ # ... for a in animals: print(_(a)) This works because the dummy definition of ‘_()’ simply returns the string unchanged. And this dummy definition will temporarily override any definition of ‘_()’ in the built-in namespace (until the *note del: f02. command). Take care, though if you have a previous definition of ‘_()’ in the local namespace. Note that the second use of ‘_()’ will not identify “a” as being translatable to the ‘gettext’ program, because the parameter is not a string literal. Another way to handle this is with the following example: def N_(message): return message animals = [N_('mollusk'), N_('albatross'), N_('rat'), N_('penguin'), N_('python'), ] # ... for a in animals: print(_(a)) In this case, you are marking translatable strings with the function ‘N_()’, which won’t conflict with any definition of ‘_()’. However, you will need to teach your message extraction program to look for translatable strings marked with ‘N_()’. ‘xgettext’, ‘pygettext’, ‘pybabel extract’, and ‘xpot’ all support this through the use of the ‘-k’ command-line switch. The choice of ‘N_()’ here is totally arbitrary; it could have just as easily been ‘MarkThisStringForTranslation()’.  File: python.info, Node: Acknowledgements<9>, Prev: Internationalizing your programs and modules, Up: gettext — Multilingual internationalization services 5.23.1.12 Acknowledgements .......................... The following people contributed code, feedback, design suggestions, previous implementations, and valuable experience to the creation of this module: * Peter Funk * James Henstridge * Juan David Ibáñez Palomar * Marc-André Lemburg * Martin von Löwis * François Pinard * Barry Warsaw * Gustavo Niemeyer  File: python.info, Node: locale — Internationalization services, Prev: gettext — Multilingual internationalization services, Up: Internationalization 5.23.2 ‘locale’ — Internationalization services ----------------------------------------------- `Source code:' Lib/locale.py(1) __________________________________________________________________ The *note locale: a9. module opens access to the POSIX locale database and functionality. The POSIX locale mechanism allows programmers to deal with certain cultural issues in an application, without requiring the programmer to know all the specifics of each country where the software is executed. The *note locale: a9. module is implemented on top of the ‘_locale’ module, which in turn uses an ANSI C locale implementation if available. The *note locale: a9. module defines the following exception and functions: -- Exception: locale.Error Exception raised when the locale passed to *note setlocale(): 1ce5. is not recognized. -- Function: locale.setlocale (category, locale=None) If `locale' is given and not ‘None’, *note setlocale(): 1ce5. modifies the locale setting for the `category'. The available categories are listed in the data description below. `locale' may be a string, or an iterable of two strings (language code and encoding). If it’s an iterable, it’s converted to a locale name using the locale aliasing engine. An empty string specifies the user’s default settings. If the modification of the locale fails, the exception *note Error: 2d79. is raised. If successful, the new locale setting is returned. If `locale' is omitted or ‘None’, the current setting for `category' is returned. *note setlocale(): 1ce5. is not thread-safe on most systems. Applications typically start with a call of import locale locale.setlocale(locale.LC_ALL, '') This sets the locale for all categories to the user’s default setting (typically specified in the ‘LANG’ environment variable). If the locale is not changed thereafter, using multithreading should not cause problems. -- Function: locale.localeconv () Returns the database of the local conventions as a dictionary. This dictionary has the following strings as keys: Category Key Meaning ---------------------------------------------------------------------------------------------------------- *note LC_NUMERIC: 2d7a. ‘'decimal_point'’ Decimal point character. ‘'grouping'’ Sequence of numbers specifying which relative positions the ‘'thousands_sep'’ is expected. If the sequence is terminated with *note CHAR_MAX: 2d7b, no further grouping is performed. If the sequence terminates with a ‘0’, the last group size is repeatedly used. ‘'thousands_sep'’ Character used between groups. *note LC_MONETARY: 2d7c. ‘'int_curr_symbol'’ International currency symbol. ‘'currency_symbol'’ Local currency symbol. ‘'p_cs_precedes/n_cs_precedes'’ Whether the currency symbol precedes the value (for positive resp. negative values). ‘'p_sep_by_space/n_sep_by_space'’ Whether the currency symbol is separated from the value by a space (for positive resp. negative values). ‘'mon_decimal_point'’ Decimal point used for monetary values. ‘'frac_digits'’ Number of fractional digits used in local formatting of monetary values. ‘'int_frac_digits'’ Number of fractional digits used in international formatting of monetary values. ‘'mon_thousands_sep'’ Group separator used for monetary values. ‘'mon_grouping'’ Equivalent to ‘'grouping'’, used for monetary values. ‘'positive_sign'’ Symbol used to annotate a positive monetary value. ‘'negative_sign'’ Symbol used to annotate a negative monetary value. ‘'p_sign_posn/n_sign_posn'’ The position of the sign (for positive resp. negative values), see below. All numeric values can be set to *note CHAR_MAX: 2d7b. to indicate that there is no value specified in this locale. The possible values for ‘'p_sign_posn'’ and ‘'n_sign_posn'’ are given below. Value Explanation ----------------------------------------------------------------- ‘0’ Currency and value are surrounded by parentheses. ‘1’ The sign should precede the value and currency symbol. ‘2’ The sign should follow the value and currency symbol. ‘3’ The sign should immediately precede the value. ‘4’ The sign should immediately follow the value. ‘CHAR_MAX’ Nothing is specified in this locale. The function sets temporarily the ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale or the ‘LC_MONETARY’ locale if locales are different and numeric or monetary strings are non-ASCII. This temporary change affects other threads. Changed in version 3.7: The function now sets temporarily the ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale in some cases. -- Function: locale.nl_langinfo (option) Return some locale-specific information as a string. This function is not available on all systems, and the set of possible options might also vary across platforms. The possible argument values are numbers, for which symbolic constants are available in the locale module. The *note nl_langinfo(): 2d7d. function accepts one of the following keys. Most descriptions are taken from the corresponding description in the GNU C library. -- Data: locale.CODESET Get a string with the name of the character encoding used in the selected locale. -- Data: locale.D_T_FMT Get a string that can be used as a format string for *note time.strftime(): b65. to represent date and time in a locale-specific way. -- Data: locale.D_FMT Get a string that can be used as a format string for *note time.strftime(): b65. to represent a date in a locale-specific way. -- Data: locale.T_FMT Get a string that can be used as a format string for *note time.strftime(): b65. to represent a time in a locale-specific way. -- Data: locale.T_FMT_AMPM Get a format string for *note time.strftime(): b65. to represent time in the am/pm format. -- Data: DAY_1 ... DAY_7 Get the name of the n-th day of the week. Note: This follows the US convention of ‘DAY_1’ being Sunday, not the international convention (ISO 8601) that Monday is the first day of the week. -- Data: ABDAY_1 ... ABDAY_7 Get the abbreviated name of the n-th day of the week. -- Data: MON_1 ... MON_12 Get the name of the n-th month. -- Data: ABMON_1 ... ABMON_12 Get the abbreviated name of the n-th month. -- Data: locale.RADIXCHAR Get the radix character (decimal dot, decimal comma, etc.). -- Data: locale.THOUSEP Get the separator character for thousands (groups of three digits). -- Data: locale.YESEXPR Get a regular expression that can be used with the regex function to recognize a positive response to a yes/no question. Note: The expression is in the syntax suitable for the ‘regex()’ function from the C library, which might differ from the syntax used in *note re: dd. -- Data: locale.NOEXPR Get a regular expression that can be used with the regex(3) function to recognize a negative response to a yes/no question. -- Data: locale.CRNCYSTR Get the currency symbol, preceded by “-” if the symbol should appear before the value, “+” if the symbol should appear after the value, or “.” if the symbol should replace the radix character. -- Data: locale.ERA Get a string that represents the era used in the current locale. Most locales do not define this value. An example of a locale which does define this value is the Japanese one. In Japan, the traditional representation of dates includes the name of the era corresponding to the then-emperor’s reign. Normally it should not be necessary to use this value directly. Specifying the ‘E’ modifier in their format strings causes the *note time.strftime(): b65. function to use this information. The format of the returned string is not specified, and therefore you should not assume knowledge of it on different systems. -- Data: locale.ERA_D_T_FMT Get a format string for *note time.strftime(): b65. to represent date and time in a locale-specific era-based way. -- Data: locale.ERA_D_FMT Get a format string for *note time.strftime(): b65. to represent a date in a locale-specific era-based way. -- Data: locale.ERA_T_FMT Get a format string for *note time.strftime(): b65. to represent a time in a locale-specific era-based way. -- Data: locale.ALT_DIGITS Get a representation of up to 100 values used to represent the values 0 to 99. -- Function: locale.getdefaultlocale ([envvars]) Tries to determine the default locale settings and returns them as a tuple of the form ‘(language code, encoding)’. According to POSIX, a program which has not called ‘setlocale(LC_ALL, '')’ runs using the portable ‘'C'’ locale. Calling ‘setlocale(LC_ALL, '')’ lets it use the default locale as defined by the ‘LANG’ variable. Since we do not want to interfere with the current locale setting we thus emulate the behavior in the way described above. To maintain compatibility with other platforms, not only the ‘LANG’ variable is tested, but a list of variables given as envvars parameter. The first found to be defined will be used. `envvars' defaults to the search path used in GNU gettext; it must always contain the variable name ‘'LANG'’. The GNU gettext search path contains ‘'LC_ALL'’, ‘'LC_CTYPE'’, ‘'LANG'’ and ‘'LANGUAGE'’, in that order. Except for the code ‘'C'’, the language code corresponds to RFC 1766(2). `language code' and `encoding' may be ‘None’ if their values cannot be determined. -- Function: locale.getlocale (category=LC_CTYPE) Returns the current setting for the given locale category as sequence containing `language code', `encoding'. `category' may be one of the ‘LC_*’ values except *note LC_ALL: 2d8d. It defaults to *note LC_CTYPE: 2d8e. Except for the code ‘'C'’, the language code corresponds to RFC 1766(3). `language code' and `encoding' may be ‘None’ if their values cannot be determined. -- Function: locale.getpreferredencoding (do_setlocale=True) Return the encoding used for text data, according to user preferences. User preferences are expressed differently on different systems, and might not be available programmatically on some systems, so this function only returns a guess. On some systems, it is necessary to invoke *note setlocale(): 1ce5. to obtain the user preferences, so this function is not thread-safe. If invoking setlocale is not necessary or desired, `do_setlocale' should be set to ‘False’. On Android or in the UTF-8 mode (*note -X: 155. ‘utf8’ option), always return ‘'UTF-8'’, the locale and the `do_setlocale' argument are ignored. Changed in version 3.7: The function now always returns ‘UTF-8’ on Android or if the UTF-8 mode is enabled. -- Function: locale.normalize (localename) Returns a normalized locale code for the given locale name. The returned locale code is formatted for use with *note setlocale(): 1ce5. If normalization fails, the original name is returned unchanged. If the given encoding is not known, the function defaults to the default encoding for the locale code just like *note setlocale(): 1ce5. -- Function: locale.resetlocale (category=LC_ALL) Sets the locale for `category' to the default setting. The default setting is determined by calling *note getdefaultlocale(): ffc. `category' defaults to *note LC_ALL: 2d8d. -- Function: locale.strcoll (string1, string2) Compares two strings according to the current *note LC_COLLATE: 2d92. setting. As any other compare function, returns a negative, or a positive value, or ‘0’, depending on whether `string1' collates before or after `string2' or is equal to it. -- Function: locale.strxfrm (string) Transforms a string to one that can be used in locale-aware comparisons. For example, ‘strxfrm(s1) < strxfrm(s2)’ is equivalent to ‘strcoll(s1, s2) < 0’. This function can be used when the same string is compared repeatedly, e.g. when collating a sequence of strings. -- Function: locale.format_string (format, val, grouping=False, monetary=False) Formats a number `val' according to the current *note LC_NUMERIC: 2d7a. setting. The format follows the conventions of the ‘%’ operator. For floating point values, the decimal point is modified if appropriate. If `grouping' is true, also takes the grouping into account. If `monetary' is true, the conversion uses monetary thousands separator and grouping strings. Processes formatting specifiers as in ‘format % val’, but takes the current locale settings into account. Changed in version 3.7: The `monetary' keyword parameter was added. -- Function: locale.format (format, val, grouping=False, monetary=False) Please note that this function works like *note format_string(): 3a4. but will only work for exactly one ‘%char’ specifier. For example, ‘'%f'’ and ‘'%.0f'’ are both valid specifiers, but ‘'%f KiB'’ is not. For whole format strings, use *note format_string(): 3a4. Deprecated since version 3.7: Use *note format_string(): 3a4. instead. -- Function: locale.currency (val, symbol=True, grouping=False, international=False) Formats a number `val' according to the current *note LC_MONETARY: 2d7c. settings. The returned string includes the currency symbol if `symbol' is true, which is the default. If `grouping' is true (which is not the default), grouping is done with the value. If `international' is true (which is not the default), the international currency symbol is used. Note that this function will not work with the ‘C’ locale, so you have to set a locale via *note setlocale(): 1ce5. first. -- Function: locale.str (float) Formats a floating point number using the same format as the built-in function ‘str(float)’, but takes the decimal point into account. -- Function: locale.delocalize (string) Converts a string into a normalized number string, following the *note LC_NUMERIC: 2d7a. settings. New in version 3.5. -- Function: locale.atof (string) Converts a string to a floating point number, following the *note LC_NUMERIC: 2d7a. settings. -- Function: locale.atoi (string) Converts a string to an integer, following the *note LC_NUMERIC: 2d7a. conventions. -- Data: locale.LC_CTYPE Locale category for the character type functions. Depending on the settings of this category, the functions of module *note string: f6. dealing with case change their behaviour. -- Data: locale.LC_COLLATE Locale category for sorting strings. The functions *note strcoll(): 2d91. and *note strxfrm(): 2d93. of the *note locale: a9. module are affected. -- Data: locale.LC_TIME Locale category for the formatting of time. The function *note time.strftime(): b65. follows these conventions. -- Data: locale.LC_MONETARY Locale category for formatting of monetary values. The available options are available from the *note localeconv(): 48a. function. -- Data: locale.LC_MESSAGES Locale category for message display. Python currently does not support application specific locale-aware messages. Messages displayed by the operating system, like those returned by *note os.strerror(): 1bd4. might be affected by this category. -- Data: locale.LC_NUMERIC Locale category for formatting numbers. The functions *note format(): 468, *note atoi(): 2d97, *note atof(): 2d96. and *note str(): 2d95. of the *note locale: a9. module are affected by that category. All other numeric formatting operations are not affected. -- Data: locale.LC_ALL Combination of all locale settings. If this flag is used when the locale is changed, setting the locale for all categories is attempted. If that fails for any category, no category is changed at all. When the locale is retrieved using this flag, a string indicating the setting for all categories is returned. This string can be later used to restore the settings. -- Data: locale.CHAR_MAX This is a symbolic constant used for different values returned by *note localeconv(): 48a. Example: >>> import locale >>> loc = locale.getlocale() # get current locale # use German locale; name might vary with platform >>> locale.setlocale(locale.LC_ALL, 'de_DE') >>> locale.strcoll('f\xe4n', 'foo') # compare a string containing an umlaut >>> locale.setlocale(locale.LC_ALL, '') # use user's preferred locale >>> locale.setlocale(locale.LC_ALL, 'C') # use default (C) locale >>> locale.setlocale(locale.LC_ALL, loc) # restore saved locale * Menu: * Background, details, hints, tips and caveats: Background details hints tips and caveats. * For extension writers and programs that embed Python:: * Access to message catalogs:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/locale.py (2) https://tools.ietf.org/html/rfc1766.html (3) https://tools.ietf.org/html/rfc1766.html  File: python.info, Node: Background details hints tips and caveats, Next: For extension writers and programs that embed Python, Up: locale — Internationalization services 5.23.2.1 Background, details, hints, tips and caveats ..................................................... The C standard defines the locale as a program-wide property that may be relatively expensive to change. On top of that, some implementation are broken in such a way that frequent locale changes may cause core dumps. This makes the locale somewhat painful to use correctly. Initially, when a program is started, the locale is the ‘C’ locale, no matter what the user’s preferred locale is. There is one exception: the *note LC_CTYPE: 2d8e. category is changed at startup to set the current locale encoding to the user’s preferred locale encoding. The program must explicitly say that it wants the user’s preferred locale settings for other categories by calling ‘setlocale(LC_ALL, '')’. It is generally a bad idea to call *note setlocale(): 1ce5. in some library routine, since as a side effect it affects the entire program. Saving and restoring it is almost as bad: it is expensive and affects other threads that happen to run before the settings have been restored. If, when coding a module for general use, you need a locale independent version of an operation that is affected by the locale (such as certain formats used with *note time.strftime(): b65.), you will have to find a way to do it without using the standard library routine. Even better is convincing yourself that using locale settings is okay. Only as a last resort should you document that your module is not compatible with non-‘C’ locale settings. The only way to perform numeric operations according to the locale is to use the special functions defined by this module: *note atof(): 2d96, *note atoi(): 2d97, *note format(): 468, *note str(): 2d95. There is no way to perform case conversions and character classifications according to the locale. For (Unicode) text strings these are done according to the character value only, while for byte strings, the conversions and classifications are done according to the ASCII value of the byte, and bytes whose high bit is set (i.e., non-ASCII bytes) are never converted or considered part of a character class such as letter or whitespace.  File: python.info, Node: For extension writers and programs that embed Python, Next: Access to message catalogs, Prev: Background details hints tips and caveats, Up: locale — Internationalization services 5.23.2.2 For extension writers and programs that embed Python ............................................................. Extension modules should never call *note setlocale(): 1ce5, except to find out what the current locale is. But since the return value can only be used portably to restore it, that is not very useful (except perhaps to find out whether or not the locale is ‘C’). When Python code uses the *note locale: a9. module to change the locale, this also affects the embedding application. If the embedding application doesn’t want this to happen, it should remove the ‘_locale’ extension module (which does all the work) from the table of built-in modules in the ‘config.c’ file, and make sure that the ‘_locale’ module is not accessible as a shared library.  File: python.info, Node: Access to message catalogs, Prev: For extension writers and programs that embed Python, Up: locale — Internationalization services 5.23.2.3 Access to message catalogs ................................... -- Function: locale.gettext (msg) -- Function: locale.dgettext (domain, msg) -- Function: locale.dcgettext (domain, msg, category) -- Function: locale.textdomain (domain) -- Function: locale.bindtextdomain (domain, dir) The locale module exposes the C library’s gettext interface on systems that provide this interface. It consists of the functions ‘gettext()’, ‘dgettext()’, ‘dcgettext()’, ‘textdomain()’, ‘bindtextdomain()’, and ‘bind_textdomain_codeset()’. These are similar to the same functions in the *note gettext: 89. module, but use the C library’s binary format for message catalogs, and the C library’s search algorithms for locating message catalogs. Python applications should normally find no need to invoke these functions, and should use *note gettext: 89. instead. A known exception to this rule are applications that link with additional C libraries which internally invoke ‘gettext()’ or ‘dcgettext()’. For these applications, it may be necessary to bind the text domain, so that the libraries can properly locate their message catalogs.  File: python.info, Node: Program Frameworks, Next: Graphical User Interfaces with Tk, Prev: Internationalization, Up: The Python Standard Library 5.24 Program Frameworks ======================= The modules described in this chapter are frameworks that will largely dictate the structure of your program. Currently the modules described here are all oriented toward writing command-line interfaces. The full list of modules described in this chapter is: * Menu: * turtle — Turtle graphics:: * cmd — Support for line-oriented command interpreters:: * shlex — Simple lexical analysis::  File: python.info, Node: turtle — Turtle graphics, Next: cmd — Support for line-oriented command interpreters, Up: Program Frameworks 5.24.1 ‘turtle’ — Turtle graphics --------------------------------- `Source code:' Lib/turtle.py(1) __________________________________________________________________ * Menu: * Introduction: Introduction<11>. * Overview of available Turtle and Screen methods:: * Methods of RawTurtle/Turtle and corresponding functions:: * Methods of TurtleScreen/Screen and corresponding functions:: * Public classes:: * Help and configuration:: * turtledemo — Demo scripts:: * Changes since Python 2.6: Changes since Python 2 6. * Changes since Python 3.0: Changes since Python 3 0. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/turtle.py  File: python.info, Node: Introduction<11>, Next: Overview of available Turtle and Screen methods, Up: turtle — Turtle graphics 5.24.1.1 Introduction ..................... Turtle graphics is a popular way for introducing programming to kids. It was part of the original Logo programming language developed by Wally Feurzeig, Seymour Papert and Cynthia Solomon in 1967. Imagine a robotic turtle starting at (0, 0) in the x-y plane. After an ‘import turtle’, give it the command ‘turtle.forward(15)’, and it moves (on-screen!) 15 pixels in the direction it is facing, drawing a line as it moves. Give it the command ‘turtle.right(25)’, and it rotates in-place 25 degrees clockwise. Turtle star ........... Turtle can draw intricate shapes using programs that repeat simple moves. [python-figures/turtle-star] from turtle import * color('red', 'yellow') begin_fill() while True: forward(200) left(170) if abs(pos()) < 1: break end_fill() done() By combining together these and similar commands, intricate shapes and pictures can easily be drawn. The *note turtle: 116. module is an extended reimplementation of the same-named module from the Python standard distribution up to version Python 2.5. It tries to keep the merits of the old turtle module and to be (nearly) 100% compatible with it. This means in the first place to enable the learning programmer to use all the commands, classes and methods interactively when using the module from within IDLE run with the ‘-n’ switch. The turtle module provides turtle graphics primitives, in both object-oriented and procedure-oriented ways. Because it uses *note tkinter: 10c. for the underlying graphics, it needs a version of Python installed with Tk support. The object-oriented interface uses essentially two+two classes: 1. The *note TurtleScreen: 2daa. class defines graphics windows as a playground for the drawing turtles. Its constructor needs a ‘tkinter.Canvas’ or a *note ScrolledCanvas: 2dab. as argument. It should be used when *note turtle: 116. is used as part of some application. The function *note Screen(): 2dac. returns a singleton object of a *note TurtleScreen: 2daa. subclass. This function should be used when *note turtle: 116. is used as a standalone tool for doing graphics. As a singleton object, inheriting from its class is not possible. All methods of TurtleScreen/Screen also exist as functions, i.e. as part of the procedure-oriented interface. 2. *note RawTurtle: 2dad. (alias: *note RawPen: 2dae.) defines Turtle objects which draw on a *note TurtleScreen: 2daa. Its constructor needs a Canvas, ScrolledCanvas or TurtleScreen as argument, so the RawTurtle objects know where to draw. Derived from RawTurtle is the subclass *note Turtle: 2daf. (alias: ‘Pen’), which draws on “the” *note Screen: 2dac. instance which is automatically created, if not already present. All methods of RawTurtle/Turtle also exist as functions, i.e. part of the procedure-oriented interface. The procedural interface provides functions which are derived from the methods of the classes *note Screen: 2dac. and *note Turtle: 2daf. They have the same names as the corresponding methods. A screen object is automatically created whenever a function derived from a Screen method is called. An (unnamed) turtle object is automatically created whenever any of the functions derived from a Turtle method is called. To use multiple turtles on a screen one has to use the object-oriented interface. Note: In the following documentation the argument list for functions is given. Methods, of course, have the additional first argument `self' which is omitted here.  File: python.info, Node: Overview of available Turtle and Screen methods, Next: Methods of RawTurtle/Turtle and corresponding functions, Prev: Introduction<11>, Up: turtle — Turtle graphics 5.24.1.2 Overview of available Turtle and Screen methods ........................................................ * Menu: * Turtle methods:: * Methods of TurtleScreen/Screen::  File: python.info, Node: Turtle methods, Next: Methods of TurtleScreen/Screen, Up: Overview of available Turtle and Screen methods 5.24.1.3 Turtle methods ....................... Turtle motion Move and draw *note forward(): 2db2. | *note fd(): 2db3. *note backward(): 2db4. | *note bk(): 2db5. | *note back(): 2db6. *note right(): 2db7. | *note rt(): 2db8. *note left(): 2db9. | *note lt(): 2dba. *note goto(): 2dbb. | *note setpos(): 2dbc. | *note setposition(): 2dbd. *note setx(): 2dbe. *note sety(): 2dbf. *note setheading(): 2dc0. | *note seth(): 2dc1. *note home(): 2dc2. *note circle(): 2dc3. *note dot(): 2dc4. *note stamp(): 2dc5. *note clearstamp(): 2dc6. *note clearstamps(): 2dc7. *note undo(): 2dc8. *note speed(): 2dc9. Tell Turtle’s state *note position(): 2dca. | *note pos(): 2dcb. *note towards(): 2dcc. *note xcor(): 2dcd. *note ycor(): 2dce. *note heading(): 2dcf. *note distance(): 2dd0. Setting and measurement *note degrees(): 2dd1. *note radians(): 2dd2. Pen control Drawing state *note pendown(): 2dd3. | *note pd(): 2dd4. | *note down(): 2dd5. *note penup(): 2dd6. | *note pu(): 2dd7. | *note up(): 2dd8. *note pensize(): 2dd9. | *note width(): 2dda. *note pen(): 2ddb. *note isdown(): 2ddc. Color control *note color(): 2ddd. *note pencolor(): 2dde. *note fillcolor(): 2ddf. Filling *note filling(): 2de0. *note begin_fill(): 2de1. *note end_fill(): 2de2. More drawing control *note reset(): 2de3. *note clear(): 2de4. *note write(): 2de5. Turtle state Visibility *note showturtle(): 2de6. | *note st(): 2de7. *note hideturtle(): 2de8. | *note ht(): 2de9. *note isvisible(): 2dea. Appearance *note shape(): 2deb. *note resizemode(): 2dec. *note shapesize(): 2ded. | *note turtlesize(): 2dee. *note shearfactor(): 2def. *note settiltangle(): 2df0. *note tiltangle(): 2df1. *note tilt(): 2df2. *note shapetransform(): 2df3. *note get_shapepoly(): 2df4. Using events *note onclick(): 2df5. *note onrelease(): 2df6. *note ondrag(): 2df7. Special Turtle methods *note begin_poly(): 2df8. *note end_poly(): 2df9. *note get_poly(): 2dfa. *note clone(): 2dfb. *note getturtle(): 2dfc. | *note getpen(): 2dfd. *note getscreen(): 2dfe. *note setundobuffer(): 2dff. *note undobufferentries(): 2e00.  File: python.info, Node: Methods of TurtleScreen/Screen, Prev: Turtle methods, Up: Overview of available Turtle and Screen methods 5.24.1.4 Methods of TurtleScreen/Screen ....................................... Window control *note bgcolor(): 2e02. *note bgpic(): 2e03. *note clear(): 2de4. | *note clearscreen(): 2e04. *note reset(): 2de3. | *note resetscreen(): 2e05. *note screensize(): 2e06. *note setworldcoordinates(): 2e07. Animation control *note delay(): 2e08. *note tracer(): 2e09. *note update(): 2e0a. Using screen events *note listen(): 2e0b. *note onkey(): 2e0c. | *note onkeyrelease(): 2e0d. *note onkeypress(): 2e0e. *note onclick(): 2df5. | *note onscreenclick(): 2e0f. *note ontimer(): 2e10. *note mainloop(): 2e11. | *note done(): 2e12. Settings and special methods *note mode(): 2e13. *note colormode(): 2e14. *note getcanvas(): 2e15. *note getshapes(): 2e16. *note register_shape(): 2e17. | *note addshape(): 2e18. *note turtles(): 2e19. *note window_height(): 2e1a. *note window_width(): 2e1b. Input methods *note textinput(): 2e1c. *note numinput(): 2e1d. Methods specific to Screen *note bye(): 2e1e. *note exitonclick(): 2e1f. *note setup(): 2e20. *note title(): 2e21.  File: python.info, Node: Methods of RawTurtle/Turtle and corresponding functions, Next: Methods of TurtleScreen/Screen and corresponding functions, Prev: Overview of available Turtle and Screen methods, Up: turtle — Turtle graphics 5.24.1.5 Methods of RawTurtle/Turtle and corresponding functions ................................................................ Most of the examples in this section refer to a Turtle instance called ‘turtle’. * Menu: * Turtle motion:: * Tell Turtle’s state:: * Settings for measurement:: * Pen control:: * Turtle state:: * Using events:: * Special Turtle methods:: * Compound shapes::  File: python.info, Node: Turtle motion, Next: Tell Turtle’s state, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.6 Turtle motion ...................... -- Function: turtle.forward (distance) -- Function: turtle.fd (distance) Parameters: ‘distance’ – a number (integer or float) Move the turtle forward by the specified `distance', in the direction the turtle is headed. >>> turtle.position() (0.00,0.00) >>> turtle.forward(25) >>> turtle.position() (25.00,0.00) >>> turtle.forward(-75) >>> turtle.position() (-50.00,0.00) -- Function: turtle.back (distance) -- Function: turtle.bk (distance) -- Function: turtle.backward (distance) Parameters: ‘distance’ – a number Move the turtle backward by `distance', opposite to the direction the turtle is headed. Do not change the turtle’s heading. >>> turtle.position() (0.00,0.00) >>> turtle.backward(30) >>> turtle.position() (-30.00,0.00) -- Function: turtle.right (angle) -- Function: turtle.rt (angle) Parameters: ‘angle’ – a number (integer or float) Turn turtle right by `angle' units. (Units are by default degrees, but can be set via the *note degrees(): 2dd1. and *note radians(): 2dd2. functions.) Angle orientation depends on the turtle mode, see *note mode(): 2e13. >>> turtle.heading() 22.0 >>> turtle.right(45) >>> turtle.heading() 337.0 -- Function: turtle.left (angle) -- Function: turtle.lt (angle) Parameters: ‘angle’ – a number (integer or float) Turn turtle left by `angle' units. (Units are by default degrees, but can be set via the *note degrees(): 2dd1. and *note radians(): 2dd2. functions.) Angle orientation depends on the turtle mode, see *note mode(): 2e13. >>> turtle.heading() 22.0 >>> turtle.left(45) >>> turtle.heading() 67.0 -- Function: turtle.goto (x, y=None) -- Function: turtle.setpos (x, y=None) -- Function: turtle.setposition (x, y=None) Parameters: * ‘x’ – a number or a pair/vector of numbers * ‘y’ – a number or ‘None’ If `y' is ‘None’, `x' must be a pair of coordinates or a *note Vec2D: 2e24. (e.g. as returned by *note pos(): 2dcb.). Move turtle to an absolute position. If the pen is down, draw line. Do not change the turtle’s orientation. >>> tp = turtle.pos() >>> tp (0.00,0.00) >>> turtle.setpos(60,30) >>> turtle.pos() (60.00,30.00) >>> turtle.setpos((20,80)) >>> turtle.pos() (20.00,80.00) >>> turtle.setpos(tp) >>> turtle.pos() (0.00,0.00) -- Function: turtle.setx (x) Parameters: ‘x’ – a number (integer or float) Set the turtle’s first coordinate to `x', leave second coordinate unchanged. >>> turtle.position() (0.00,240.00) >>> turtle.setx(10) >>> turtle.position() (10.00,240.00) -- Function: turtle.sety (y) Parameters: ‘y’ – a number (integer or float) Set the turtle’s second coordinate to `y', leave first coordinate unchanged. >>> turtle.position() (0.00,40.00) >>> turtle.sety(-10) >>> turtle.position() (0.00,-10.00) -- Function: turtle.setheading (to_angle) -- Function: turtle.seth (to_angle) Parameters: ‘to_angle’ – a number (integer or float) Set the orientation of the turtle to `to_angle'. Here are some common directions in degrees: standard mode logo mode ------------------------------------------------- 0 - east 0 - north 90 - north 90 - east 180 - west 180 - south 270 - south 270 - west >>> turtle.setheading(90) >>> turtle.heading() 90.0 -- Function: turtle.home () Move turtle to the origin – coordinates (0,0) – and set its heading to its start-orientation (which depends on the mode, see *note mode(): 2e13.). >>> turtle.heading() 90.0 >>> turtle.position() (0.00,-10.00) >>> turtle.home() >>> turtle.position() (0.00,0.00) >>> turtle.heading() 0.0 -- Function: turtle.circle (radius, extent=None, steps=None) Parameters: * ‘radius’ – a number * ‘extent’ – a number (or ‘None’) * ‘steps’ – an integer (or ‘None’) Draw a circle with given `radius'. The center is `radius' units left of the turtle; `extent' – an angle – determines which part of the circle is drawn. If `extent' is not given, draw the entire circle. If `extent' is not a full circle, one endpoint of the arc is the current pen position. Draw the arc in counterclockwise direction if `radius' is positive, otherwise in clockwise direction. Finally the direction of the turtle is changed by the amount of `extent'. As the circle is approximated by an inscribed regular polygon, `steps' determines the number of steps to use. If not given, it will be calculated automatically. May be used to draw regular polygons. >>> turtle.home() >>> turtle.position() (0.00,0.00) >>> turtle.heading() 0.0 >>> turtle.circle(50) >>> turtle.position() (-0.00,0.00) >>> turtle.heading() 0.0 >>> turtle.circle(120, 180) # draw a semicircle >>> turtle.position() (0.00,240.00) >>> turtle.heading() 180.0 -- Function: turtle.dot (size=None, *color) Parameters: * ‘size’ – an integer >= 1 (if given) * ‘color’ – a colorstring or a numeric color tuple Draw a circular dot with diameter `size', using `color'. If `size' is not given, the maximum of pensize+4 and 2*pensize is used. >>> turtle.home() >>> turtle.dot() >>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50) >>> turtle.position() (100.00,-0.00) >>> turtle.heading() 0.0 -- Function: turtle.stamp () Stamp a copy of the turtle shape onto the canvas at the current turtle position. Return a stamp_id for that stamp, which can be used to delete it by calling ‘clearstamp(stamp_id)’. >>> turtle.color("blue") >>> turtle.stamp() 11 >>> turtle.fd(50) -- Function: turtle.clearstamp (stampid) Parameters: ‘stampid’ – an integer, must be return value of previous *note stamp(): 2dc5. call Delete stamp with given `stampid'. >>> turtle.position() (150.00,-0.00) >>> turtle.color("blue") >>> astamp = turtle.stamp() >>> turtle.fd(50) >>> turtle.position() (200.00,-0.00) >>> turtle.clearstamp(astamp) >>> turtle.position() (200.00,-0.00) -- Function: turtle.clearstamps (n=None) Parameters: ‘n’ – an integer (or ‘None’) Delete all or first/last `n' of turtle’s stamps. If `n' is ‘None’, delete all stamps, if `n' > 0 delete first `n' stamps, else if `n' < 0 delete last `n' stamps. >>> for i in range(8): ... turtle.stamp(); turtle.fd(30) 13 14 15 16 17 18 19 20 >>> turtle.clearstamps(2) >>> turtle.clearstamps(-2) >>> turtle.clearstamps() -- Function: turtle.undo () Undo (repeatedly) the last turtle action(s). Number of available undo actions is determined by the size of the undobuffer. >>> for i in range(4): ... turtle.fd(50); turtle.lt(80) ... >>> for i in range(8): ... turtle.undo() -- Function: turtle.speed (speed=None) Parameters: ‘speed’ – an integer in the range 0..10 or a speedstring (see below) Set the turtle’s speed to an integer value in the range 0..10. If no argument is given, return current speed. If input is a number greater than 10 or smaller than 0.5, speed is set to 0. Speedstrings are mapped to speedvalues as follows: * “fastest”: 0 * “fast”: 10 * “normal”: 6 * “slow”: 3 * “slowest”: 1 Speeds from 1 to 10 enforce increasingly faster animation of line drawing and turtle turning. Attention: `speed' = 0 means that `no' animation takes place. forward/back makes turtle jump and likewise left/right make the turtle turn instantly. >>> turtle.speed() 3 >>> turtle.speed('normal') >>> turtle.speed() 6 >>> turtle.speed(9) >>> turtle.speed() 9  File: python.info, Node: Tell Turtle’s state, Next: Settings for measurement, Prev: Turtle motion, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.7 Tell Turtle’s state ............................ -- Function: turtle.position () -- Function: turtle.pos () Return the turtle’s current location (x,y) (as a *note Vec2D: 2e24. vector). >>> turtle.pos() (440.00,-0.00) -- Function: turtle.towards (x, y=None) Parameters: * ‘x’ – a number or a pair/vector of numbers or a turtle instance * ‘y’ – a number if `x' is a number, else ‘None’ Return the angle between the line from turtle position to position specified by (x,y), the vector or the other turtle. This depends on the turtle’s start orientation which depends on the mode - “standard”/”world” or “logo”. >>> turtle.goto(10, 10) >>> turtle.towards(0,0) 225.0 -- Function: turtle.xcor () Return the turtle’s x coordinate. >>> turtle.home() >>> turtle.left(50) >>> turtle.forward(100) >>> turtle.pos() (64.28,76.60) >>> print(round(turtle.xcor(), 5)) 64.27876 -- Function: turtle.ycor () Return the turtle’s y coordinate. >>> turtle.home() >>> turtle.left(60) >>> turtle.forward(100) >>> print(turtle.pos()) (50.00,86.60) >>> print(round(turtle.ycor(), 5)) 86.60254 -- Function: turtle.heading () Return the turtle’s current heading (value depends on the turtle mode, see *note mode(): 2e13.). >>> turtle.home() >>> turtle.left(67) >>> turtle.heading() 67.0 -- Function: turtle.distance (x, y=None) Parameters: * ‘x’ – a number or a pair/vector of numbers or a turtle instance * ‘y’ – a number if `x' is a number, else ‘None’ Return the distance from the turtle to (x,y), the given vector, or the given other turtle, in turtle step units. >>> turtle.home() >>> turtle.distance(30,40) 50.0 >>> turtle.distance((30,40)) 50.0 >>> joe = Turtle() >>> joe.forward(77) >>> turtle.distance(joe) 77.0  File: python.info, Node: Settings for measurement, Next: Pen control, Prev: Tell Turtle’s state, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.8 Settings for measurement ................................. -- Function: turtle.degrees (fullcircle=360.0) Parameters: ‘fullcircle’ – a number Set angle measurement units, i.e. set number of “degrees” for a full circle. Default value is 360 degrees. >>> turtle.home() >>> turtle.left(90) >>> turtle.heading() 90.0 Change angle measurement unit to grad (also known as gon, grade, or gradian and equals 1/100-th of the right angle.) >>> turtle.degrees(400.0) >>> turtle.heading() 100.0 >>> turtle.degrees(360) >>> turtle.heading() 90.0 -- Function: turtle.radians () Set the angle measurement units to radians. Equivalent to ‘degrees(2*math.pi)’. >>> turtle.home() >>> turtle.left(90) >>> turtle.heading() 90.0 >>> turtle.radians() >>> turtle.heading() 1.5707963267948966  File: python.info, Node: Pen control, Next: Turtle state, Prev: Settings for measurement, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.9 Pen control .................... * Menu: * Drawing state:: * Color control:: * Filling:: * More drawing control::  File: python.info, Node: Drawing state, Next: Color control, Up: Pen control 5.24.1.10 Drawing state ....................... -- Function: turtle.pendown () -- Function: turtle.pd () -- Function: turtle.down () Pull the pen down – drawing when moving. -- Function: turtle.penup () -- Function: turtle.pu () -- Function: turtle.up () Pull the pen up – no drawing when moving. -- Function: turtle.pensize (width=None) -- Function: turtle.width (width=None) Parameters: ‘width’ – a positive number Set the line thickness to `width' or return it. If resizemode is set to “auto” and turtleshape is a polygon, that polygon is drawn with the same line thickness. If no argument is given, the current pensize is returned. >>> turtle.pensize() 1 >>> turtle.pensize(10) # from here on lines of width 10 are drawn -- Function: turtle.pen (pen=None, **pendict) Parameters: * ‘pen’ – a dictionary with some or all of the below listed keys * ‘pendict’ – one or more keyword-arguments with the below listed keys as keywords Return or set the pen’s attributes in a “pen-dictionary” with the following key/value pairs: * “shown”: True/False * “pendown”: True/False * “pencolor”: color-string or color-tuple * “fillcolor”: color-string or color-tuple * “pensize”: positive number * “speed”: number in range 0..10 * “resizemode”: “auto” or “user” or “noresize” * “stretchfactor”: (positive number, positive number) * “outline”: positive number * “tilt”: number This dictionary can be used as argument for a subsequent call to *note pen(): 2ddb. to restore the former pen-state. Moreover one or more of these attributes can be provided as keyword-arguments. This can be used to set several pen attributes in one statement. >>> turtle.pen(fillcolor="black", pencolor="red", pensize=10) >>> sorted(turtle.pen().items()) [('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'), ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'), ('shearfactor', 0.0), ('shown', True), ('speed', 9), ('stretchfactor', (1.0, 1.0)), ('tilt', 0.0)] >>> penstate=turtle.pen() >>> turtle.color("yellow", "") >>> turtle.penup() >>> sorted(turtle.pen().items())[:3] [('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow')] >>> turtle.pen(penstate, fillcolor="green") >>> sorted(turtle.pen().items())[:3] [('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red')] -- Function: turtle.isdown () Return ‘True’ if pen is down, ‘False’ if it’s up. >>> turtle.penup() >>> turtle.isdown() False >>> turtle.pendown() >>> turtle.isdown() True  File: python.info, Node: Color control, Next: Filling, Prev: Drawing state, Up: Pen control 5.24.1.11 Color control ....................... -- Function: turtle.pencolor (*args) Return or set the pencolor. Four input formats are allowed: ‘pencolor()’ Return the current pencolor as color specification string or as a tuple (see example). May be used as input to another color/pencolor/fillcolor call. ‘pencolor(colorstring)’ Set pencolor to `colorstring', which is a Tk color specification string, such as ‘"red"’, ‘"yellow"’, or ‘"#33cc8c"’. ‘pencolor((r, g, b))’ Set pencolor to the RGB color represented by the tuple of `r', `g', and `b'. Each of `r', `g', and `b' must be in the range 0..colormode, where colormode is either 1.0 or 255 (see *note colormode(): 2e14.). ‘pencolor(r, g, b)’ Set pencolor to the RGB color represented by `r', `g', and `b'. Each of `r', `g', and `b' must be in the range 0..colormode. If turtleshape is a polygon, the outline of that polygon is drawn with the newly set pencolor. >>> colormode() 1.0 >>> turtle.pencolor() 'red' >>> turtle.pencolor("brown") >>> turtle.pencolor() 'brown' >>> tup = (0.2, 0.8, 0.55) >>> turtle.pencolor(tup) >>> turtle.pencolor() (0.2, 0.8, 0.5490196078431373) >>> colormode(255) >>> turtle.pencolor() (51.0, 204.0, 140.0) >>> turtle.pencolor('#32c18f') >>> turtle.pencolor() (50.0, 193.0, 143.0) -- Function: turtle.fillcolor (*args) Return or set the fillcolor. Four input formats are allowed: ‘fillcolor()’ Return the current fillcolor as color specification string, possibly in tuple format (see example). May be used as input to another color/pencolor/fillcolor call. ‘fillcolor(colorstring)’ Set fillcolor to `colorstring', which is a Tk color specification string, such as ‘"red"’, ‘"yellow"’, or ‘"#33cc8c"’. ‘fillcolor((r, g, b))’ Set fillcolor to the RGB color represented by the tuple of `r', `g', and `b'. Each of `r', `g', and `b' must be in the range 0..colormode, where colormode is either 1.0 or 255 (see *note colormode(): 2e14.). ‘fillcolor(r, g, b)’ Set fillcolor to the RGB color represented by `r', `g', and `b'. Each of `r', `g', and `b' must be in the range 0..colormode. If turtleshape is a polygon, the interior of that polygon is drawn with the newly set fillcolor. >>> turtle.fillcolor("violet") >>> turtle.fillcolor() 'violet' >>> turtle.pencolor() (50.0, 193.0, 143.0) >>> turtle.fillcolor((50, 193, 143)) # Integers, not floats >>> turtle.fillcolor() (50.0, 193.0, 143.0) >>> turtle.fillcolor('#ffffff') >>> turtle.fillcolor() (255.0, 255.0, 255.0) -- Function: turtle.color (*args) Return or set pencolor and fillcolor. Several input formats are allowed. They use 0 to 3 arguments as follows: ‘color()’ Return the current pencolor and the current fillcolor as a pair of color specification strings or tuples as returned by *note pencolor(): 2dde. and *note fillcolor(): 2ddf. ‘color(colorstring)’, ‘color((r,g,b))’, ‘color(r,g,b)’ Inputs as in *note pencolor(): 2dde, set both, fillcolor and pencolor, to the given value. ‘color(colorstring1, colorstring2)’, ‘color((r1,g1,b1), (r2,g2,b2))’ Equivalent to ‘pencolor(colorstring1)’ and ‘fillcolor(colorstring2)’ and analogously if the other input format is used. If turtleshape is a polygon, outline and interior of that polygon is drawn with the newly set colors. >>> turtle.color("red", "green") >>> turtle.color() ('red', 'green') >>> color("#285078", "#a0c8f0") >>> color() ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0)) See also: Screen method *note colormode(): 2e14.  File: python.info, Node: Filling, Next: More drawing control, Prev: Color control, Up: Pen control 5.24.1.12 Filling ................. -- Function: turtle.filling () Return fillstate (‘True’ if filling, ‘False’ else). >>> turtle.begin_fill() >>> if turtle.filling(): ... turtle.pensize(5) ... else: ... turtle.pensize(3) -- Function: turtle.begin_fill () To be called just before drawing a shape to be filled. -- Function: turtle.end_fill () Fill the shape drawn after the last call to *note begin_fill(): 2de1. Whether or not overlap regions for self-intersecting polygons or multiple shapes are filled depends on the operating system graphics, type of overlap, and number of overlaps. For example, the Turtle star above may be either all yellow or have some white regions. >>> turtle.color("black", "red") >>> turtle.begin_fill() >>> turtle.circle(80) >>> turtle.end_fill()  File: python.info, Node: More drawing control, Prev: Filling, Up: Pen control 5.24.1.13 More drawing control .............................. -- Function: turtle.reset () Delete the turtle’s drawings from the screen, re-center the turtle and set variables to the default values. >>> turtle.goto(0,-22) >>> turtle.left(100) >>> turtle.position() (0.00,-22.00) >>> turtle.heading() 100.0 >>> turtle.reset() >>> turtle.position() (0.00,0.00) >>> turtle.heading() 0.0 -- Function: turtle.clear () Delete the turtle’s drawings from the screen. Do not move turtle. State and position of the turtle as well as drawings of other turtles are not affected. -- Function: turtle.write (arg, move=False, align="left", font=("Arial", 8, "normal")) Parameters: * ‘arg’ – object to be written to the TurtleScreen * ‘move’ – True/False * ‘align’ – one of the strings “left”, “center” or right” * ‘font’ – a triple (fontname, fontsize, fonttype) Write text - the string representation of `arg' - at the current turtle position according to `align' (“left”, “center” or “right”) and with the given font. If `move' is true, the pen is moved to the bottom-right corner of the text. By default, `move' is ‘False’. >>> turtle.write("Home = ", True, align="center") >>> turtle.write((0,0), True)  File: python.info, Node: Turtle state, Next: Using events, Prev: Pen control, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.14 Turtle state ...................... * Menu: * Visibility:: * Appearance::  File: python.info, Node: Visibility, Next: Appearance, Up: Turtle state 5.24.1.15 Visibility .................... -- Function: turtle.hideturtle () -- Function: turtle.ht () Make the turtle invisible. It’s a good idea to do this while you’re in the middle of doing some complex drawing, because hiding the turtle speeds up the drawing observably. >>> turtle.hideturtle() -- Function: turtle.showturtle () -- Function: turtle.st () Make the turtle visible. >>> turtle.showturtle() -- Function: turtle.isvisible () Return ‘True’ if the Turtle is shown, ‘False’ if it’s hidden. >>> turtle.hideturtle() >>> turtle.isvisible() False >>> turtle.showturtle() >>> turtle.isvisible() True  File: python.info, Node: Appearance, Prev: Visibility, Up: Turtle state 5.24.1.16 Appearance .................... -- Function: turtle.shape (name=None) Parameters: ‘name’ – a string which is a valid shapename Set turtle shape to shape with given `name' or, if name is not given, return name of current shape. Shape with `name' must exist in the TurtleScreen’s shape dictionary. Initially there are the following polygon shapes: “arrow”, “turtle”, “circle”, “square”, “triangle”, “classic”. To learn about how to deal with shapes see Screen method *note register_shape(): 2e17. >>> turtle.shape() 'classic' >>> turtle.shape("turtle") >>> turtle.shape() 'turtle' -- Function: turtle.resizemode (rmode=None) Parameters: ‘rmode’ – one of the strings “auto”, “user”, “noresize” Set resizemode to one of the values: “auto”, “user”, “noresize”. If `rmode' is not given, return current resizemode. Different resizemodes have the following effects: - “auto”: adapts the appearance of the turtle corresponding to the value of pensize. - “user”: adapts the appearance of the turtle according to the values of stretchfactor and outlinewidth (outline), which are set by *note shapesize(): 2ded. - “noresize”: no adaption of the turtle’s appearance takes place. ‘resizemode("user")’ is called by *note shapesize(): 2ded. when used with arguments. >>> turtle.resizemode() 'noresize' >>> turtle.resizemode("auto") >>> turtle.resizemode() 'auto' -- Function: turtle.shapesize (stretch_wid=None, stretch_len=None, outline=None) -- Function: turtle.turtlesize (stretch_wid=None, stretch_len=None, outline=None) Parameters: * ‘stretch_wid’ – positive number * ‘stretch_len’ – positive number * ‘outline’ – positive number Return or set the pen’s attributes x/y-stretchfactors and/or outline. Set resizemode to “user”. If and only if resizemode is set to “user”, the turtle will be displayed stretched according to its stretchfactors: `stretch_wid' is stretchfactor perpendicular to its orientation, `stretch_len' is stretchfactor in direction of its orientation, `outline' determines the width of the shapes’s outline. >>> turtle.shapesize() (1.0, 1.0, 1) >>> turtle.resizemode("user") >>> turtle.shapesize(5, 5, 12) >>> turtle.shapesize() (5, 5, 12) >>> turtle.shapesize(outline=8) >>> turtle.shapesize() (5, 5, 8) -- Function: turtle.shearfactor (shear=None) Parameters: ‘shear’ – number (optional) Set or return the current shearfactor. Shear the turtleshape according to the given shearfactor shear, which is the tangent of the shear angle. Do `not' change the turtle’s heading (direction of movement). If shear is not given: return the current shearfactor, i. e. the tangent of the shear angle, by which lines parallel to the heading of the turtle are sheared. >>> turtle.shape("circle") >>> turtle.shapesize(5,2) >>> turtle.shearfactor(0.5) >>> turtle.shearfactor() 0.5 -- Function: turtle.tilt (angle) Parameters: ‘angle’ – a number Rotate the turtleshape by `angle' from its current tilt-angle, but do `not' change the turtle’s heading (direction of movement). >>> turtle.reset() >>> turtle.shape("circle") >>> turtle.shapesize(5,2) >>> turtle.tilt(30) >>> turtle.fd(50) >>> turtle.tilt(30) >>> turtle.fd(50) -- Function: turtle.settiltangle (angle) Parameters: ‘angle’ – a number Rotate the turtleshape to point in the direction specified by `angle', regardless of its current tilt-angle. `Do not' change the turtle’s heading (direction of movement). >>> turtle.reset() >>> turtle.shape("circle") >>> turtle.shapesize(5,2) >>> turtle.settiltangle(45) >>> turtle.fd(50) >>> turtle.settiltangle(-45) >>> turtle.fd(50) Deprecated since version 3.1. -- Function: turtle.tiltangle (angle=None) Parameters: ‘angle’ – a number (optional) Set or return the current tilt-angle. If angle is given, rotate the turtleshape to point in the direction specified by angle, regardless of its current tilt-angle. Do `not' change the turtle’s heading (direction of movement). If angle is not given: return the current tilt-angle, i. e. the angle between the orientation of the turtleshape and the heading of the turtle (its direction of movement). >>> turtle.reset() >>> turtle.shape("circle") >>> turtle.shapesize(5,2) >>> turtle.tilt(45) >>> turtle.tiltangle() 45.0 -- Function: turtle.shapetransform (t11=None, t12=None, t21=None, t22=None) Parameters: * ‘t11’ – a number (optional) * ‘t12’ – a number (optional) * ‘t21’ – a number (optional) * ‘t12’ – a number (optional) Set or return the current transformation matrix of the turtle shape. If none of the matrix elements are given, return the transformation matrix as a tuple of 4 elements. Otherwise set the given elements and transform the turtleshape according to the matrix consisting of first row t11, t12 and second row t21, t22. The determinant t11 * t22 - t12 * t21 must not be zero, otherwise an error is raised. Modify stretchfactor, shearfactor and tiltangle according to the given matrix. >>> turtle = Turtle() >>> turtle.shape("square") >>> turtle.shapesize(4,2) >>> turtle.shearfactor(-0.5) >>> turtle.shapetransform() (4.0, -1.0, -0.0, 2.0) -- Function: turtle.get_shapepoly () Return the current shape polygon as tuple of coordinate pairs. This can be used to define a new shape or components of a compound shape. >>> turtle.shape("square") >>> turtle.shapetransform(4, -1, 0, 2) >>> turtle.get_shapepoly() ((50, -20), (30, 20), (-50, 20), (-30, -20))  File: python.info, Node: Using events, Next: Special Turtle methods, Prev: Turtle state, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.17 Using events ...................... -- Function: turtle.onclick (fun, btn=1, add=None) Parameters: * ‘fun’ – a function with two arguments which will be called with the coordinates of the clicked point on the canvas * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse button) * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be added, otherwise it will replace a former binding Bind `fun' to mouse-click events on this turtle. If `fun' is ‘None’, existing bindings are removed. Example for the anonymous turtle, i.e. the procedural way: >>> def turn(x, y): ... left(180) ... >>> onclick(turn) # Now clicking into the turtle will turn it. >>> onclick(None) # event-binding will be removed -- Function: turtle.onrelease (fun, btn=1, add=None) Parameters: * ‘fun’ – a function with two arguments which will be called with the coordinates of the clicked point on the canvas * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse button) * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be added, otherwise it will replace a former binding Bind `fun' to mouse-button-release events on this turtle. If `fun' is ‘None’, existing bindings are removed. >>> class MyTurtle(Turtle): ... def glow(self,x,y): ... self.fillcolor("red") ... def unglow(self,x,y): ... self.fillcolor("") ... >>> turtle = MyTurtle() >>> turtle.onclick(turtle.glow) # clicking on turtle turns fillcolor red, >>> turtle.onrelease(turtle.unglow) # releasing turns it to transparent. -- Function: turtle.ondrag (fun, btn=1, add=None) Parameters: * ‘fun’ – a function with two arguments which will be called with the coordinates of the clicked point on the canvas * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse button) * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be added, otherwise it will replace a former binding Bind `fun' to mouse-move events on this turtle. If `fun' is ‘None’, existing bindings are removed. Remark: Every sequence of mouse-move-events on a turtle is preceded by a mouse-click event on that turtle. >>> turtle.ondrag(turtle.goto) Subsequently, clicking and dragging the Turtle will move it across the screen thereby producing handdrawings (if pen is down).  File: python.info, Node: Special Turtle methods, Next: Compound shapes, Prev: Using events, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.18 Special Turtle methods ................................ -- Function: turtle.begin_poly () Start recording the vertices of a polygon. Current turtle position is first vertex of polygon. -- Function: turtle.end_poly () Stop recording the vertices of a polygon. Current turtle position is last vertex of polygon. This will be connected with the first vertex. -- Function: turtle.get_poly () Return the last recorded polygon. >>> turtle.home() >>> turtle.begin_poly() >>> turtle.fd(100) >>> turtle.left(20) >>> turtle.fd(30) >>> turtle.left(60) >>> turtle.fd(50) >>> turtle.end_poly() >>> p = turtle.get_poly() >>> register_shape("myFavouriteShape", p) -- Function: turtle.clone () Create and return a clone of the turtle with same position, heading and turtle properties. >>> mick = Turtle() >>> joe = mick.clone() -- Function: turtle.getturtle () -- Function: turtle.getpen () Return the Turtle object itself. Only reasonable use: as a function to return the “anonymous turtle”: >>> pet = getturtle() >>> pet.fd(50) >>> pet <turtle.Turtle object at 0x...> -- Function: turtle.getscreen () Return the *note TurtleScreen: 2daa. object the turtle is drawing on. TurtleScreen methods can then be called for that object. >>> ts = turtle.getscreen() >>> ts <turtle._Screen object at 0x...> >>> ts.bgcolor("pink") -- Function: turtle.setundobuffer (size) Parameters: ‘size’ – an integer or ‘None’ Set or disable undobuffer. If `size' is an integer, an empty undobuffer of given size is installed. `size' gives the maximum number of turtle actions that can be undone by the *note undo(): 2dc8. method/function. If `size' is ‘None’, the undobuffer is disabled. >>> turtle.setundobuffer(42) -- Function: turtle.undobufferentries () Return number of entries in the undobuffer. >>> while undobufferentries(): ... undo()  File: python.info, Node: Compound shapes, Prev: Special Turtle methods, Up: Methods of RawTurtle/Turtle and corresponding functions 5.24.1.19 Compound shapes ......................... To use compound turtle shapes, which consist of several polygons of different color, you must use the helper class *note Shape: 2e33. explicitly as described below: 1. Create an empty Shape object of type “compound”. 2. Add as many components to this object as desired, using the ‘addcomponent()’ method. For example: >>> s = Shape("compound") >>> poly1 = ((0,0),(10,-5),(0,10),(-10,-5)) >>> s.addcomponent(poly1, "red", "blue") >>> poly2 = ((0,0),(10,-5),(-10,-5)) >>> s.addcomponent(poly2, "blue", "red") 3. Now add the Shape to the Screen’s shapelist and use it: >>> register_shape("myshape", s) >>> shape("myshape") Note: The *note Shape: 2e33. class is used internally by the *note register_shape(): 2e17. method in different ways. The application programmer has to deal with the Shape class `only' when using compound shapes like shown above!  File: python.info, Node: Methods of TurtleScreen/Screen and corresponding functions, Next: Public classes, Prev: Methods of RawTurtle/Turtle and corresponding functions, Up: turtle — Turtle graphics 5.24.1.20 Methods of TurtleScreen/Screen and corresponding functions .................................................................... Most of the examples in this section refer to a TurtleScreen instance called ‘screen’. * Menu: * Window control:: * Animation control:: * Using screen events:: * Input methods:: * Settings and special methods:: * Methods specific to Screen, not inherited from TurtleScreen: Methods specific to Screen not inherited from TurtleScreen.  File: python.info, Node: Window control, Next: Animation control, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.21 Window control ........................ -- Function: turtle.bgcolor (*args) Parameters: ‘args’ – a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers Set or return background color of the TurtleScreen. >>> screen.bgcolor("orange") >>> screen.bgcolor() 'orange' >>> screen.bgcolor("#800080") >>> screen.bgcolor() (128.0, 0.0, 128.0) -- Function: turtle.bgpic (picname=None) Parameters: ‘picname’ – a string, name of a gif-file or ‘"nopic"’, or ‘None’ Set background image or return name of current backgroundimage. If `picname' is a filename, set the corresponding image as background. If `picname' is ‘"nopic"’, delete background image, if present. If `picname' is ‘None’, return the filename of the current backgroundimage. >>> screen.bgpic() 'nopic' >>> screen.bgpic("landscape.gif") >>> screen.bgpic() "landscape.gif" -- Function: turtle.clear () -- Function: turtle.clearscreen () Delete all drawings and all turtles from the TurtleScreen. Reset the now empty TurtleScreen to its initial state: white background, no background image, no event bindings and tracing on. Note: This TurtleScreen method is available as a global function only under the name ‘clearscreen’. The global function ‘clear’ is a different one derived from the Turtle method ‘clear’. -- Function: turtle.reset () -- Function: turtle.resetscreen () Reset all Turtles on the Screen to their initial state. Note: This TurtleScreen method is available as a global function only under the name ‘resetscreen’. The global function ‘reset’ is another one derived from the Turtle method ‘reset’. -- Function: turtle.screensize (canvwidth=None, canvheight=None, bg=None) Parameters: * ‘canvwidth’ – positive integer, new width of canvas in pixels * ‘canvheight’ – positive integer, new height of canvas in pixels * ‘bg’ – colorstring or color-tuple, new background color If no arguments are given, return current (canvaswidth, canvasheight). Else resize the canvas the turtles are drawing on. Do not alter the drawing window. To observe hidden parts of the canvas, use the scrollbars. With this method, one can make visible those parts of a drawing which were outside the canvas before. >>> screen.screensize() (400, 300) >>> screen.screensize(2000,1500) >>> screen.screensize() (2000, 1500) e.g. to search for an erroneously escaped turtle ;-) -- Function: turtle.setworldcoordinates (llx, lly, urx, ury) Parameters: * ‘llx’ – a number, x-coordinate of lower left corner of canvas * ‘lly’ – a number, y-coordinate of lower left corner of canvas * ‘urx’ – a number, x-coordinate of upper right corner of canvas * ‘ury’ – a number, y-coordinate of upper right corner of canvas Set up user-defined coordinate system and switch to mode “world” if necessary. This performs a ‘screen.reset()’. If mode “world” is already active, all drawings are redrawn according to the new coordinates. `ATTENTION': in user-defined coordinate systems angles may appear distorted. >>> screen.reset() >>> screen.setworldcoordinates(-50,-7.5,50,7.5) >>> for _ in range(72): ... left(10) ... >>> for _ in range(8): ... left(45); fd(2) # a regular octagon  File: python.info, Node: Animation control, Next: Using screen events, Prev: Window control, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.22 Animation control ........................... -- Function: turtle.delay (delay=None) Parameters: ‘delay’ – positive integer Set or return the drawing `delay' in milliseconds. (This is approximately the time interval between two consecutive canvas updates.) The longer the drawing delay, the slower the animation. Optional argument: >>> screen.delay() 10 >>> screen.delay(5) >>> screen.delay() 5 -- Function: turtle.tracer (n=None, delay=None) Parameters: * ‘n’ – nonnegative integer * ‘delay’ – nonnegative integer Turn turtle animation on/off and set delay for update drawings. If `n' is given, only each n-th regular screen update is really performed. (Can be used to accelerate the drawing of complex graphics.) When called without arguments, returns the currently stored value of n. Second argument sets delay value (see *note delay(): 2e08.). >>> screen.tracer(8, 25) >>> dist = 2 >>> for i in range(200): ... fd(dist) ... rt(90) ... dist += 2 -- Function: turtle.update () Perform a TurtleScreen update. To be used when tracer is turned off. See also the RawTurtle/Turtle method *note speed(): 2dc9.  File: python.info, Node: Using screen events, Next: Input methods, Prev: Animation control, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.23 Using screen events ............................. -- Function: turtle.listen (xdummy=None, ydummy=None) Set focus on TurtleScreen (in order to collect key-events). Dummy arguments are provided in order to be able to pass *note listen(): 2e0b. to the onclick method. -- Function: turtle.onkey (fun, key) -- Function: turtle.onkeyrelease (fun, key) Parameters: * ‘fun’ – a function with no arguments or ‘None’ * ‘key’ – a string: key (e.g. “a”) or key-symbol (e.g. “space”) Bind `fun' to key-release event of key. If `fun' is ‘None’, event bindings are removed. Remark: in order to be able to register key-events, TurtleScreen must have the focus. (See method *note listen(): 2e0b.) >>> def f(): ... fd(50) ... lt(60) ... >>> screen.onkey(f, "Up") >>> screen.listen() -- Function: turtle.onkeypress (fun, key=None) Parameters: * ‘fun’ – a function with no arguments or ‘None’ * ‘key’ – a string: key (e.g. “a”) or key-symbol (e.g. “space”) Bind `fun' to key-press event of key if key is given, or to any key-press-event if no key is given. Remark: in order to be able to register key-events, TurtleScreen must have focus. (See method *note listen(): 2e0b.) >>> def f(): ... fd(50) ... >>> screen.onkey(f, "Up") >>> screen.listen() -- Function: turtle.onclick (fun, btn=1, add=None) -- Function: turtle.onscreenclick (fun, btn=1, add=None) Parameters: * ‘fun’ – a function with two arguments which will be called with the coordinates of the clicked point on the canvas * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse button) * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be added, otherwise it will replace a former binding Bind `fun' to mouse-click events on this screen. If `fun' is ‘None’, existing bindings are removed. Example for a TurtleScreen instance named ‘screen’ and a Turtle instance named ‘turtle’: >>> screen.onclick(turtle.goto) # Subsequently clicking into the TurtleScreen will >>> # make the turtle move to the clicked point. >>> screen.onclick(None) # remove event binding again Note: This TurtleScreen method is available as a global function only under the name ‘onscreenclick’. The global function ‘onclick’ is another one derived from the Turtle method ‘onclick’. -- Function: turtle.ontimer (fun, t=0) Parameters: * ‘fun’ – a function with no arguments * ‘t’ – a number >= 0 Install a timer that calls `fun' after `t' milliseconds. >>> running = True >>> def f(): ... if running: ... fd(50) ... lt(60) ... screen.ontimer(f, 250) >>> f() ### makes the turtle march around >>> running = False -- Function: turtle.mainloop () -- Function: turtle.done () Starts event loop - calling Tkinter’s mainloop function. Must be the last statement in a turtle graphics program. Must `not' be used if a script is run from within IDLE in -n mode (No subprocess) - for interactive use of turtle graphics. >>> screen.mainloop()  File: python.info, Node: Input methods, Next: Settings and special methods, Prev: Using screen events, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.24 Input methods ....................... -- Function: turtle.textinput (title, prompt) Parameters: * ‘title’ – string * ‘prompt’ – string Pop up a dialog window for input of a string. Parameter title is the title of the dialog window, prompt is a text mostly describing what information to input. Return the string input. If the dialog is canceled, return ‘None’. >>> screen.textinput("NIM", "Name of first player:") -- Function: turtle.numinput (title, prompt, default=None, minval=None, maxval=None) Parameters: * ‘title’ – string * ‘prompt’ – string * ‘default’ – number (optional) * ‘minval’ – number (optional) * ‘maxval’ – number (optional) Pop up a dialog window for input of a number. title is the title of the dialog window, prompt is a text mostly describing what numerical information to input. default: default value, minval: minimum value for input, maxval: maximum value for input The number input must be in the range minval .. maxval if these are given. If not, a hint is issued and the dialog remains open for correction. Return the number input. If the dialog is canceled, return ‘None’. >>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)  File: python.info, Node: Settings and special methods, Next: Methods specific to Screen not inherited from TurtleScreen, Prev: Input methods, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.25 Settings and special methods ...................................... -- Function: turtle.mode (mode=None) Parameters: ‘mode’ – one of the strings “standard”, “logo” or “world” Set turtle mode (“standard”, “logo” or “world”) and perform reset. If mode is not given, current mode is returned. Mode “standard” is compatible with old *note turtle: 116. Mode “logo” is compatible with most Logo turtle graphics. Mode “world” uses user-defined “world coordinates”. `Attention': in this mode angles appear distorted if ‘x/y’ unit-ratio doesn’t equal 1. Mode Initial turtle heading positive angles ----------------------------------------------------------------------- “standard” to the right (east) counterclockwise “logo” upward (north) clockwise >>> mode("logo") # resets turtle heading to north >>> mode() 'logo' -- Function: turtle.colormode (cmode=None) Parameters: ‘cmode’ – one of the values 1.0 or 255 Return the colormode or set it to 1.0 or 255. Subsequently `r', `g', `b' values of color triples have to be in the range 0..`cmode'. >>> screen.colormode(1) >>> turtle.pencolor(240, 160, 80) Traceback (most recent call last): ... TurtleGraphicsError: bad color sequence: (240, 160, 80) >>> screen.colormode() 1.0 >>> screen.colormode(255) >>> screen.colormode() 255 >>> turtle.pencolor(240,160,80) -- Function: turtle.getcanvas () Return the Canvas of this TurtleScreen. Useful for insiders who know what to do with a Tkinter Canvas. >>> cv = screen.getcanvas() >>> cv <turtle.ScrolledCanvas object ...> -- Function: turtle.getshapes () Return a list of names of all currently available turtle shapes. >>> screen.getshapes() ['arrow', 'blank', 'circle', ..., 'turtle'] -- Function: turtle.register_shape (name, shape=None) -- Function: turtle.addshape (name, shape=None) There are three different ways to call this function: 1. `name' is the name of a gif-file and `shape' is ‘None’: Install the corresponding image shape. >>> screen.register_shape("turtle.gif") Note: Image shapes `do not' rotate when turning the turtle, so they do not display the heading of the turtle! 2. `name' is an arbitrary string and `shape' is a tuple of pairs of coordinates: Install the corresponding polygon shape. >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3))) 3. `name' is an arbitrary string and shape is a (compound) *note Shape: 2e33. object: Install the corresponding compound shape. Add a turtle shape to TurtleScreen’s shapelist. Only thusly registered shapes can be used by issuing the command ‘shape(shapename)’. -- Function: turtle.turtles () Return the list of turtles on the screen. >>> for turtle in screen.turtles(): ... turtle.color("red") -- Function: turtle.window_height () Return the height of the turtle window. >>> screen.window_height() 480 -- Function: turtle.window_width () Return the width of the turtle window. >>> screen.window_width() 640  File: python.info, Node: Methods specific to Screen not inherited from TurtleScreen, Prev: Settings and special methods, Up: Methods of TurtleScreen/Screen and corresponding functions 5.24.1.26 Methods specific to Screen, not inherited from TurtleScreen ..................................................................... -- Function: turtle.bye () Shut the turtlegraphics window. -- Function: turtle.exitonclick () Bind ‘bye()’ method to mouse clicks on the Screen. If the value “using_IDLE” in the configuration dictionary is ‘False’ (default value), also enter mainloop. Remark: If IDLE with the ‘-n’ switch (no subprocess) is used, this value should be set to ‘True’ in ‘turtle.cfg’. In this case IDLE’s own mainloop is active also for the client script. -- Function: turtle.setup (width=_CFG["width"], height=_CFG["height"], startx=_CFG["leftright"], starty=_CFG["topbottom"]) Set the size and position of the main window. Default values of arguments are stored in the configuration dictionary and can be changed via a ‘turtle.cfg’ file. Parameters: * ‘width’ – if an integer, a size in pixels, if a float, a fraction of the screen; default is 50% of screen * ‘height’ – if an integer, the height in pixels, if a float, a fraction of the screen; default is 75% of screen * ‘startx’ – if positive, starting position in pixels from the left edge of the screen, if negative from the right edge, if ‘None’, center window horizontally * ‘starty’ – if positive, starting position in pixels from the top edge of the screen, if negative from the bottom edge, if ‘None’, center window vertically >>> screen.setup (width=200, height=200, startx=0, starty=0) >>> # sets window to 200x200 pixels, in upper left of screen >>> screen.setup(width=.75, height=0.5, startx=None, starty=None) >>> # sets window to 75% of screen by 50% of screen and centers -- Function: turtle.title (titlestring) Parameters: ‘titlestring’ – a string that is shown in the titlebar of the turtle graphics window Set title of turtle window to `titlestring'. >>> screen.title("Welcome to the turtle zoo!")  File: python.info, Node: Public classes, Next: Help and configuration, Prev: Methods of TurtleScreen/Screen and corresponding functions, Up: turtle — Turtle graphics 5.24.1.27 Public classes ........................ -- Class: turtle.RawTurtle (canvas) -- Class: turtle.RawPen (canvas) Parameters: ‘canvas’ – a ‘tkinter.Canvas’, a *note ScrolledCanvas: 2dab. or a *note TurtleScreen: 2daa. Create a turtle. The turtle has all methods described above as “methods of Turtle/RawTurtle”. -- Class: turtle.Turtle Subclass of RawTurtle, has the same interface but draws on a default *note Screen: 2dac. object created automatically when needed for the first time. -- Class: turtle.TurtleScreen (cv) Parameters: ‘cv’ – a ‘tkinter.Canvas’ Provides screen oriented methods like ‘setbg()’ etc. that are described above. -- Class: turtle.Screen Subclass of TurtleScreen, with *note four methods added: 2e3b. -- Class: turtle.ScrolledCanvas (master) Parameters: ‘master’ – some Tkinter widget to contain the ScrolledCanvas, i.e. a Tkinter-canvas with scrollbars added Used by class Screen, which thus automatically provides a ScrolledCanvas as playground for the turtles. -- Class: turtle.Shape (type_, data) Parameters: ‘type_’ – one of the strings “polygon”, “image”, “compound” Data structure modeling shapes. The pair ‘(type_, data)’ must follow this specification: `type_' `data' ------------------------------------------------------------------------------- “polygon” a polygon-tuple, i.e. a tuple of pairs of coordinates “image” an image (in this form only used internally!) “compound” ‘None’ (a compound shape has to be constructed using the *note addcomponent(): 2e3d. method) -- Method: addcomponent (poly, fill, outline=None) Parameters: * ‘poly’ – a polygon, i.e. a tuple of pairs of numbers * ‘fill’ – a color the `poly' will be filled with * ‘outline’ – a color for the poly’s outline (if given) Example: >>> poly = ((0,0),(10,-5),(0,10),(-10,-5)) >>> s = Shape("compound") >>> s.addcomponent(poly, "red", "blue") >>> # ... add more components and then use register_shape() See *note Compound shapes: 2e32. -- Class: turtle.Vec2D (x, y) A two-dimensional vector class, used as a helper class for implementing turtle graphics. May be useful for turtle graphics programs too. Derived from tuple, so a vector is a tuple! Provides (for `a', `b' vectors, `k' number): * ‘a + b’ vector addition * ‘a - b’ vector subtraction * ‘a * b’ inner product * ‘k * a’ and ‘a * k’ multiplication with scalar * ‘abs(a)’ absolute value of a * ‘a.rotate(angle)’ rotation  File: python.info, Node: Help and configuration, Next: turtledemo — Demo scripts, Prev: Public classes, Up: turtle — Turtle graphics 5.24.1.28 Help and configuration ................................ * Menu: * How to use help:: * Translation of docstrings into different languages:: * How to configure Screen and Turtles::  File: python.info, Node: How to use help, Next: Translation of docstrings into different languages, Up: Help and configuration 5.24.1.29 How to use help ......................... The public methods of the Screen and Turtle classes are documented extensively via docstrings. So these can be used as online-help via the Python help facilities: - When using IDLE, tooltips show the signatures and first lines of the docstrings of typed in function-/method calls. - Calling *note help(): 572. on methods or functions displays the docstrings: >>> help(Screen.bgcolor) Help on method bgcolor in module turtle: bgcolor(self, *args) unbound turtle.Screen method Set or return backgroundcolor of the TurtleScreen. Arguments (if given): a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers. >>> screen.bgcolor("orange") >>> screen.bgcolor() "orange" >>> screen.bgcolor(0.5,0,0.5) >>> screen.bgcolor() "#800080" >>> help(Turtle.penup) Help on method penup in module turtle: penup(self) unbound turtle.Turtle method Pull the pen up -- no drawing when moving. Aliases: penup | pu | up No argument >>> turtle.penup() - The docstrings of the functions which are derived from methods have a modified form: >>> help(bgcolor) Help on function bgcolor in module turtle: bgcolor(*args) Set or return backgroundcolor of the TurtleScreen. Arguments (if given): a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers. Example:: >>> bgcolor("orange") >>> bgcolor() "orange" >>> bgcolor(0.5,0,0.5) >>> bgcolor() "#800080" >>> help(penup) Help on function penup in module turtle: penup() Pull the pen up -- no drawing when moving. Aliases: penup | pu | up No argument Example: >>> penup() These modified docstrings are created automatically together with the function definitions that are derived from the methods at import time.  File: python.info, Node: Translation of docstrings into different languages, Next: How to configure Screen and Turtles, Prev: How to use help, Up: Help and configuration 5.24.1.30 Translation of docstrings into different languages ............................................................ There is a utility to create a dictionary the keys of which are the method names and the values of which are the docstrings of the public methods of the classes Screen and Turtle. -- Function: turtle.write_docstringdict (filename="turtle_docstringdict") Parameters: ‘filename’ – a string, used as filename Create and write docstring-dictionary to a Python script with the given filename. This function has to be called explicitly (it is not used by the turtle graphics classes). The docstring dictionary will be written to the Python script ‘`filename'.py’. It is intended to serve as a template for translation of the docstrings into different languages. If you (or your students) want to use *note turtle: 116. with online help in your native language, you have to translate the docstrings and save the resulting file as e.g. ‘turtle_docstringdict_german.py’. If you have an appropriate entry in your ‘turtle.cfg’ file this dictionary will be read in at import time and will replace the original English docstrings. At the time of this writing there are docstring dictionaries in German and in Italian. (Requests please to <glingl@aon.at>.)  File: python.info, Node: How to configure Screen and Turtles, Prev: Translation of docstrings into different languages, Up: Help and configuration 5.24.1.31 How to configure Screen and Turtles ............................................. The built-in default configuration mimics the appearance and behaviour of the old turtle module in order to retain best possible compatibility with it. If you want to use a different configuration which better reflects the features of this module or which better fits to your needs, e.g. for use in a classroom, you can prepare a configuration file ‘turtle.cfg’ which will be read at import time and modify the configuration according to its settings. The built in configuration would correspond to the following turtle.cfg: width = 0.5 height = 0.75 leftright = None topbottom = None canvwidth = 400 canvheight = 300 mode = standard colormode = 1.0 delay = 10 undobuffersize = 1000 shape = classic pencolor = black fillcolor = black resizemode = noresize visible = True language = english exampleturtle = turtle examplescreen = screen title = Python Turtle Graphics using_IDLE = False Short explanation of selected entries: - The first four lines correspond to the arguments of the ‘Screen.setup()’ method. - Line 5 and 6 correspond to the arguments of the method ‘Screen.screensize()’. - `shape' can be any of the built-in shapes, e.g: arrow, turtle, etc. For more info try ‘help(shape)’. - If you want to use no fillcolor (i.e. make the turtle transparent), you have to write ‘fillcolor = ""’ (but all nonempty strings must not have quotes in the cfg-file). - If you want to reflect the turtle its state, you have to use ‘resizemode = auto’. - If you set e.g. ‘language = italian’ the docstringdict ‘turtle_docstringdict_italian.py’ will be loaded at import time (if present on the import path, e.g. in the same directory as *note turtle: 116. - The entries `exampleturtle' and `examplescreen' define the names of these objects as they occur in the docstrings. The transformation of method-docstrings to function-docstrings will delete these names from the docstrings. - `using_IDLE': Set this to ‘True’ if you regularly work with IDLE and its -n switch (“no subprocess”). This will prevent *note exitonclick(): 2e1f. to enter the mainloop. There can be a ‘turtle.cfg’ file in the directory where *note turtle: 116. is stored and an additional one in the current working directory. The latter will override the settings of the first one. The ‘Lib/turtledemo’ directory contains a ‘turtle.cfg’ file. You can study it as an example and see its effects when running the demos (preferably not from within the demo-viewer).  File: python.info, Node: turtledemo — Demo scripts, Next: Changes since Python 2 6, Prev: Help and configuration, Up: turtle — Turtle graphics 5.24.1.32 ‘turtledemo’ — Demo scripts ..................................... The *note turtledemo: 117. package includes a set of demo scripts. These scripts can be run and viewed using the supplied demo viewer as follows: python -m turtledemo Alternatively, you can run the demo scripts individually. For example, python -m turtledemo.bytedesign The *note turtledemo: 117. package directory contains: - A demo viewer ‘__main__.py’ which can be used to view the sourcecode of the scripts and run them at the same time. - Multiple scripts demonstrating different features of the *note turtle: 116. module. Examples can be accessed via the Examples menu. They can also be run standalone. - A ‘turtle.cfg’ file which serves as an example of how to write and use such files. The demo scripts are: Name Description Features ------------------------------------------------------------------------------------ bytedesign complex classical turtle ‘tracer()’, delay, graphics pattern ‘update()’ chaos graphs Verhulst dynamics, shows world coordinates that computer’s computations can generate results sometimes against the common sense expectations clock analog clock showing time of turtles as clock’s hands, your computer ontimer colormixer experiment with r, g, b ‘ondrag()’ forest 3 breadth-first trees randomization fractalcurves Hilbert & Koch curves recursion lindenmayer ethnomathematics (indian kolams) L-System minimal_hanoi Towers of Hanoi Rectangular Turtles as Hanoi discs (shape, shapesize) nim play the classical nim game with turtles as nimsticks, three heaps of sticks against event driven (mouse, the computer. keyboard) paint super minimalistic drawing ‘onclick()’ program peace elementary turtle: appearance and animation penrose aperiodic tiling with kites and ‘stamp()’ darts planet_and_moon simulation of gravitational compound shapes, ‘Vec2D’ system round_dance dancing turtles rotating compound shapes, clone pairwise in opposite direction shapesize, tilt, get_shapepoly, update sorting_animate visual demonstration of simple alignment, different sorting methods randomization tree a (graphical) breadth first tree ‘clone()’ (using generators) two_canvases simple design turtles on two canvases wikipedia a pattern from the wikipedia ‘clone()’, ‘undo()’ article on turtle graphics yinyang another elementary example ‘circle()’ Have fun!  File: python.info, Node: Changes since Python 2 6, Next: Changes since Python 3 0, Prev: turtledemo — Demo scripts, Up: turtle — Turtle graphics 5.24.1.33 Changes since Python 2.6 .................................. - The methods ‘Turtle.tracer()’, ‘Turtle.window_width()’ and ‘Turtle.window_height()’ have been eliminated. Methods with these names and functionality are now available only as methods of ‘Screen’. The functions derived from these remain available. (In fact already in Python 2.6 these methods were merely duplications of the corresponding ‘TurtleScreen’/‘Screen’-methods.) - The method ‘Turtle.fill()’ has been eliminated. The behaviour of ‘begin_fill()’ and ‘end_fill()’ have changed slightly: now every filling-process must be completed with an ‘end_fill()’ call. - A method ‘Turtle.filling()’ has been added. It returns a boolean value: ‘True’ if a filling process is under way, ‘False’ otherwise. This behaviour corresponds to a ‘fill()’ call without arguments in Python 2.6.  File: python.info, Node: Changes since Python 3 0, Prev: Changes since Python 2 6, Up: turtle — Turtle graphics 5.24.1.34 Changes since Python 3.0 .................................. - The methods ‘Turtle.shearfactor()’, ‘Turtle.shapetransform()’ and ‘Turtle.get_shapepoly()’ have been added. Thus the full range of regular linear transforms is now available for transforming turtle shapes. ‘Turtle.tiltangle()’ has been enhanced in functionality: it now can be used to get or set the tiltangle. ‘Turtle.settiltangle()’ has been deprecated. - The method ‘Screen.onkeypress()’ has been added as a complement to ‘Screen.onkey()’ which in fact binds actions to the keyrelease event. Accordingly the latter has got an alias: ‘Screen.onkeyrelease()’. - The method ‘Screen.mainloop()’ has been added. So when working only with Screen and Turtle objects one must not additionally import ‘mainloop()’ anymore. - Two input methods has been added ‘Screen.textinput()’ and ‘Screen.numinput()’. These popup input dialogs and return strings and numbers respectively. - Two example scripts ‘tdemo_nim.py’ and ‘tdemo_round_dance.py’ have been added to the ‘Lib/turtledemo’ directory.  File: python.info, Node: cmd — Support for line-oriented command interpreters, Next: shlex — Simple lexical analysis, Prev: turtle — Turtle graphics, Up: Program Frameworks 5.24.2 ‘cmd’ — Support for line-oriented command interpreters ------------------------------------------------------------- `Source code:' Lib/cmd.py(1) __________________________________________________________________ The *note Cmd: 2e48. class provides a simple framework for writing line-oriented command interpreters. These are often useful for test harnesses, administrative tools, and prototypes that will later be wrapped in a more sophisticated interface. -- Class: cmd.Cmd (completekey='tab', stdin=None, stdout=None) A *note Cmd: 2e48. instance or subclass instance is a line-oriented interpreter framework. There is no good reason to instantiate *note Cmd: 2e48. itself; rather, it’s useful as a superclass of an interpreter class you define yourself in order to inherit *note Cmd: 2e48.’s methods and encapsulate action methods. The optional argument `completekey' is the *note readline: de. name of a completion key; it defaults to ‘Tab’. If `completekey' is not *note None: 157. and *note readline: de. is available, command completion is done automatically. The optional arguments `stdin' and `stdout' specify the input and output file objects that the Cmd instance or subclass instance will use for input and output. If not specified, they will default to *note sys.stdin: 30d. and *note sys.stdout: 30e. If you want a given `stdin' to be used, make sure to set the instance’s *note use_rawinput: 2e49. attribute to ‘False’, otherwise `stdin' will be ignored. * Menu: * Cmd Objects:: * Cmd Example:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/cmd.py  File: python.info, Node: Cmd Objects, Next: Cmd Example, Up: cmd — Support for line-oriented command interpreters 5.24.2.1 Cmd Objects .................... A *note Cmd: 2e48. instance has the following methods: -- Method: Cmd.cmdloop (intro=None) Repeatedly issue a prompt, accept input, parse an initial prefix off the received input, and dispatch to action methods, passing them the remainder of the line as argument. The optional argument is a banner or intro string to be issued before the first prompt (this overrides the *note intro: 2e4d. class attribute). If the *note readline: de. module is loaded, input will automatically inherit ‘bash’-like history-list editing (e.g. ‘Control-P’ scrolls back to the last command, ‘Control-N’ forward to the next one, ‘Control-F’ moves the cursor to the right non-destructively, ‘Control-B’ moves the cursor to the left non-destructively, etc.). An end-of-file on input is passed back as the string ‘'EOF'’. An interpreter instance will recognize a command name ‘foo’ if and only if it has a method ‘do_foo()’. As a special case, a line beginning with the character ‘'?'’ is dispatched to the method ‘do_help()’. As another special case, a line beginning with the character ‘'!'’ is dispatched to the method ‘do_shell()’ (if such a method is defined). This method will return when the *note postcmd(): 2e4e. method returns a true value. The `stop' argument to *note postcmd(): 2e4e. is the return value from the command’s corresponding ‘do_*()’ method. If completion is enabled, completing commands will be done automatically, and completing of commands args is done by calling ‘complete_foo()’ with arguments `text', `line', `begidx', and `endidx'. `text' is the string prefix we are attempting to match: all returned matches must begin with it. `line' is the current input line with leading whitespace removed, `begidx' and `endidx' are the beginning and ending indexes of the prefix text, which could be used to provide different completion depending upon which position the argument is in. All subclasses of *note Cmd: 2e48. inherit a predefined ‘do_help()’. This method, called with an argument ‘'bar'’, invokes the corresponding method ‘help_bar()’, and if that is not present, prints the docstring of ‘do_bar()’, if available. With no argument, ‘do_help()’ lists all available help topics (that is, all commands with corresponding ‘help_*()’ methods or commands that have docstrings), and also lists any undocumented commands. -- Method: Cmd.onecmd (str) Interpret the argument as though it had been typed in response to the prompt. This may be overridden, but should not normally need to be; see the *note precmd(): 2e50. and *note postcmd(): 2e4e. methods for useful execution hooks. The return value is a flag indicating whether interpretation of commands by the interpreter should stop. If there is a ‘do_*()’ method for the command `str', the return value of that method is returned, otherwise the return value from the *note default(): 2e51. method is returned. -- Method: Cmd.emptyline () Method called when an empty line is entered in response to the prompt. If this method is not overridden, it repeats the last nonempty command entered. -- Method: Cmd.default (line) Method called on an input line when the command prefix is not recognized. If this method is not overridden, it prints an error message and returns. -- Method: Cmd.completedefault (text, line, begidx, endidx) Method called to complete an input line when no command-specific ‘complete_*()’ method is available. By default, it returns an empty list. -- Method: Cmd.precmd (line) Hook method executed just before the command line `line' is interpreted, but after the input prompt is generated and issued. This method is a stub in *note Cmd: 2e48.; it exists to be overridden by subclasses. The return value is used as the command which will be executed by the *note onecmd(): 2e4f. method; the *note precmd(): 2e50. implementation may re-write the command or simply return `line' unchanged. -- Method: Cmd.postcmd (stop, line) Hook method executed just after a command dispatch is finished. This method is a stub in *note Cmd: 2e48.; it exists to be overridden by subclasses. `line' is the command line which was executed, and `stop' is a flag which indicates whether execution will be terminated after the call to *note postcmd(): 2e4e.; this will be the return value of the *note onecmd(): 2e4f. method. The return value of this method will be used as the new value for the internal flag which corresponds to `stop'; returning false will cause interpretation to continue. -- Method: Cmd.preloop () Hook method executed once when *note cmdloop(): 2e4c. is called. This method is a stub in *note Cmd: 2e48.; it exists to be overridden by subclasses. -- Method: Cmd.postloop () Hook method executed once when *note cmdloop(): 2e4c. is about to return. This method is a stub in *note Cmd: 2e48.; it exists to be overridden by subclasses. Instances of *note Cmd: 2e48. subclasses have some public instance variables: -- Attribute: Cmd.prompt The prompt issued to solicit input. -- Attribute: Cmd.identchars The string of characters accepted for the command prefix. -- Attribute: Cmd.lastcmd The last nonempty command prefix seen. -- Attribute: Cmd.cmdqueue A list of queued input lines. The cmdqueue list is checked in *note cmdloop(): 2e4c. when new input is needed; if it is nonempty, its elements will be processed in order, as if entered at the prompt. -- Attribute: Cmd.intro A string to issue as an intro or banner. May be overridden by giving the *note cmdloop(): 2e4c. method an argument. -- Attribute: Cmd.doc_header The header to issue if the help output has a section for documented commands. -- Attribute: Cmd.misc_header The header to issue if the help output has a section for miscellaneous help topics (that is, there are ‘help_*()’ methods without corresponding ‘do_*()’ methods). -- Attribute: Cmd.undoc_header The header to issue if the help output has a section for undocumented commands (that is, there are ‘do_*()’ methods without corresponding ‘help_*()’ methods). -- Attribute: Cmd.ruler The character used to draw separator lines under the help-message headers. If empty, no ruler line is drawn. It defaults to ‘'='’. -- Attribute: Cmd.use_rawinput A flag, defaulting to true. If true, *note cmdloop(): 2e4c. uses *note input(): c6b. to display a prompt and read the next command; if false, ‘sys.stdout.write()’ and ‘sys.stdin.readline()’ are used. (This means that by importing *note readline: de, on systems that support it, the interpreter will automatically support ‘Emacs’-like line editing and command-history keystrokes.)  File: python.info, Node: Cmd Example, Prev: Cmd Objects, Up: cmd — Support for line-oriented command interpreters 5.24.2.2 Cmd Example .................... The *note cmd: 1a. module is mainly useful for building custom shells that let a user work with a program interactively. This section presents a simple example of how to build a shell around a few of the commands in the *note turtle: 116. module. Basic turtle commands such as *note forward(): 2db2. are added to a *note Cmd: 2e48. subclass with method named ‘do_forward()’. The argument is converted to a number and dispatched to the turtle module. The docstring is used in the help utility provided by the shell. The example also includes a basic record and playback facility implemented with the *note precmd(): 2e50. method which is responsible for converting the input to lowercase and writing the commands to a file. The ‘do_playback()’ method reads the file and adds the recorded commands to the ‘cmdqueue’ for immediate playback: import cmd, sys from turtle import * class TurtleShell(cmd.Cmd): intro = 'Welcome to the turtle shell. Type help or ? to list commands.\n' prompt = '(turtle) ' file = None # ----- basic turtle commands ----- def do_forward(self, arg): 'Move the turtle forward by the specified distance: FORWARD 10' forward(*parse(arg)) def do_right(self, arg): 'Turn turtle right by given number of degrees: RIGHT 20' right(*parse(arg)) def do_left(self, arg): 'Turn turtle left by given number of degrees: LEFT 90' left(*parse(arg)) def do_goto(self, arg): 'Move turtle to an absolute position with changing orientation. GOTO 100 200' goto(*parse(arg)) def do_home(self, arg): 'Return turtle to the home position: HOME' home() def do_circle(self, arg): 'Draw circle with given radius an options extent and steps: CIRCLE 50' circle(*parse(arg)) def do_position(self, arg): 'Print the current turtle position: POSITION' print('Current position is %d %d\n' % position()) def do_heading(self, arg): 'Print the current turtle heading in degrees: HEADING' print('Current heading is %d\n' % (heading(),)) def do_color(self, arg): 'Set the color: COLOR BLUE' color(arg.lower()) def do_undo(self, arg): 'Undo (repeatedly) the last turtle action(s): UNDO' def do_reset(self, arg): 'Clear the screen and return turtle to center: RESET' reset() def do_bye(self, arg): 'Stop recording, close the turtle window, and exit: BYE' print('Thank you for using Turtle') self.close() bye() return True # ----- record and playback ----- def do_record(self, arg): 'Save future commands to filename: RECORD rose.cmd' self.file = open(arg, 'w') def do_playback(self, arg): 'Playback commands from a file: PLAYBACK rose.cmd' self.close() with open(arg) as f: self.cmdqueue.extend(f.read().splitlines()) def precmd(self, line): line = line.lower() if self.file and 'playback' not in line: print(line, file=self.file) return line def close(self): if self.file: self.file.close() self.file = None def parse(arg): 'Convert a series of zero or more numbers to an argument tuple' return tuple(map(int, arg.split())) if __name__ == '__main__': TurtleShell().cmdloop() Here is a sample session with the turtle shell showing the help functions, using blank lines to repeat commands, and the simple record and playback facility: Welcome to the turtle shell. Type help or ? to list commands. (turtle) ? Documented commands (type help <topic>): ======================================== bye color goto home playback record right circle forward heading left position reset undo (turtle) help forward Move the turtle forward by the specified distance: FORWARD 10 (turtle) record spiral.cmd (turtle) position Current position is 0 0 (turtle) heading Current heading is 0 (turtle) reset (turtle) circle 20 (turtle) right 30 (turtle) circle 40 (turtle) right 30 (turtle) circle 60 (turtle) right 30 (turtle) circle 80 (turtle) right 30 (turtle) circle 100 (turtle) right 30 (turtle) circle 120 (turtle) right 30 (turtle) circle 120 (turtle) heading Current heading is 180 (turtle) forward 100 (turtle) (turtle) right 90 (turtle) forward 100 (turtle) (turtle) right 90 (turtle) forward 400 (turtle) right 90 (turtle) forward 500 (turtle) right 90 (turtle) forward 400 (turtle) right 90 (turtle) forward 300 (turtle) playback spiral.cmd Current position is 0 0 Current heading is 0 Current heading is 180 (turtle) bye Thank you for using Turtle  File: python.info, Node: shlex — Simple lexical analysis, Prev: cmd — Support for line-oriented command interpreters, Up: Program Frameworks 5.24.3 ‘shlex’ — Simple lexical analysis ---------------------------------------- `Source code:' Lib/shlex.py(1) __________________________________________________________________ The *note shlex: 57a. class makes it easy to write lexical analyzers for simple syntaxes resembling that of the Unix shell. This will often be useful for writing minilanguages, (for example, in run control files for Python applications) or for parsing quoted strings. The *note shlex: e8. module defines the following functions: -- Function: shlex.split (s, comments=False, posix=True) Split the string `s' using shell-like syntax. If `comments' is *note False: 388. (the default), the parsing of comments in the given string will be disabled (setting the *note commenters: 2e62. attribute of the *note shlex: 57a. instance to the empty string). This function operates in POSIX mode by default, but uses non-POSIX mode if the `posix' argument is false. Note: Since the *note split(): 218. function instantiates a *note shlex: 57a. instance, passing ‘None’ for `s' will read the string to split from standard input. -- Function: shlex.join (split_command) Concatenate the tokens of the list `split_command' and return a string. This function is the inverse of *note split(): 218. >>> from shlex import join >>> print(join(['echo', '-n', 'Multiple words'])) echo -n 'Multiple words' The returned value is shell-escaped to protect against injection vulnerabilities (see *note quote(): a73.). New in version 3.8. -- Function: shlex.quote (s) Return a shell-escaped version of the string `s'. The returned value is a string that can safely be used as one token in a shell command line, for cases where you cannot use a list. This idiom would be unsafe: >>> filename = 'somefile; rm -rf ~' >>> command = 'ls -l {}'.format(filename) >>> print(command) # executed by a shell: boom! ls -l somefile; rm -rf ~ *note quote(): a73. lets you plug the security hole: >>> from shlex import quote >>> command = 'ls -l {}'.format(quote(filename)) >>> print(command) ls -l 'somefile; rm -rf ~' >>> remote_command = 'ssh home {}'.format(quote(command)) >>> print(remote_command) ssh home 'ls -l '"'"'somefile; rm -rf ~'"'"'' The quoting is compatible with UNIX shells and with *note split(): 218.: >>> from shlex import split >>> remote_command = split(remote_command) >>> remote_command ['ssh', 'home', "ls -l 'somefile; rm -rf ~'"] >>> command = split(remote_command[-1]) >>> command ['ls', '-l', 'somefile; rm -rf ~'] New in version 3.3. The *note shlex: e8. module defines the following class: -- Class: shlex.shlex (instream=None, infile=None, posix=False, punctuation_chars=False) A *note shlex: 57a. instance or subclass instance is a lexical analyzer object. The initialization argument, if present, specifies where to read characters from. It must be a file-/stream-like object with *note read(): 1ce1. and *note readline(): 18b9. methods, or a string. If no argument is given, input will be taken from ‘sys.stdin’. The second optional argument is a filename string, which sets the initial value of the *note infile: 2e63. attribute. If the `instream' argument is omitted or equal to ‘sys.stdin’, this second argument defaults to “stdin”. The `posix' argument defines the operational mode: when `posix' is not true (default), the *note shlex: 57a. instance will operate in compatibility mode. When operating in POSIX mode, *note shlex: 57a. will try to be as close as possible to the POSIX shell parsing rules. The `punctuation_chars' argument provides a way to make the behaviour even closer to how real shells parse. This can take a number of values: the default value, ‘False’, preserves the behaviour seen under Python 3.5 and earlier. If set to ‘True’, then parsing of the characters ‘();<>|&’ is changed: any run of these characters (considered punctuation characters) is returned as a single token. If set to a non-empty string of characters, those characters will be used as the punctuation characters. Any characters in the *note wordchars: 2e64. attribute that appear in `punctuation_chars' will be removed from *note wordchars: 2e64. See *note Improved Compatibility with Shells: 57b. for more information. `punctuation_chars' can be set only upon *note shlex: 57a. instance creation and can’t be modified later. Changed in version 3.6: The `punctuation_chars' parameter was added. See also ........ Module *note configparser: 23. Parser for configuration files similar to the Windows ‘.ini’ files. * Menu: * shlex Objects:: * Parsing Rules:: * Improved Compatibility with Shells:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/shlex.py  File: python.info, Node: shlex Objects, Next: Parsing Rules, Up: shlex — Simple lexical analysis 5.24.3.1 shlex Objects ...................... A *note shlex: 57a. instance has the following methods: -- Method: shlex.get_token () Return a token. If tokens have been stacked using *note push_token(): 2e68, pop a token off the stack. Otherwise, read one from the input stream. If reading encounters an immediate end-of-file, *note eof: 2e69. is returned (the empty string (‘''’) in non-POSIX mode, and ‘None’ in POSIX mode). -- Method: shlex.push_token (str) Push the argument onto the token stack. -- Method: shlex.read_token () Read a raw token. Ignore the pushback stack, and do not interpret source requests. (This is not ordinarily a useful entry point, and is documented here only for the sake of completeness.) -- Method: shlex.sourcehook (filename) When *note shlex: 57a. detects a source request (see *note source: 2e6c. below) this method is given the following token as argument, and expected to return a tuple consisting of a filename and an open file-like object. Normally, this method first strips any quotes off the argument. If the result is an absolute pathname, or there was no previous source request in effect, or the previous source was a stream (such as ‘sys.stdin’), the result is left alone. Otherwise, if the result is a relative pathname, the directory part of the name of the file immediately before it on the source inclusion stack is prepended (this behavior is like the way the C preprocessor handles ‘#include "file.h"’). The result of the manipulations is treated as a filename, and returned as the first component of the tuple, with *note open(): 4f0. called on it to yield the second component. (Note: this is the reverse of the order of arguments in instance initialization!) This hook is exposed so that you can use it to implement directory search paths, addition of file extensions, and other namespace hacks. There is no corresponding ‘close’ hook, but a shlex instance will call the *note close(): 1bdd. method of the sourced input stream when it returns EOF. For more explicit control of source stacking, use the *note push_source(): 2e6d. and *note pop_source(): 2e6e. methods. -- Method: shlex.push_source (newstream, newfile=None) Push an input source stream onto the input stack. If the filename argument is specified it will later be available for use in error messages. This is the same method used internally by the *note sourcehook(): 2e6b. method. -- Method: shlex.pop_source () Pop the last-pushed input source from the input stack. This is the same method used internally when the lexer reaches EOF on a stacked input stream. -- Method: shlex.error_leader (infile=None, lineno=None) This method generates an error message leader in the format of a Unix C compiler error label; the format is ‘'"%s", line %d: '’, where the ‘%s’ is replaced with the name of the current source file and the ‘%d’ with the current input line number (the optional arguments can be used to override these). This convenience is provided to encourage *note shlex: e8. users to generate error messages in the standard, parseable format understood by Emacs and other Unix tools. Instances of *note shlex: 57a. subclasses have some public instance variables which either control lexical analysis or can be used for debugging: -- Attribute: shlex.commenters The string of characters that are recognized as comment beginners. All characters from the comment beginner to end of line are ignored. Includes just ‘'#'’ by default. -- Attribute: shlex.wordchars The string of characters that will accumulate into multi-character tokens. By default, includes all ASCII alphanumerics and underscore. In POSIX mode, the accented characters in the Latin-1 set are also included. If *note punctuation_chars: 2e70. is not empty, the characters ‘~-./*?=’, which can appear in filename specifications and command line parameters, will also be included in this attribute, and any characters which appear in ‘punctuation_chars’ will be removed from ‘wordchars’ if they are present there. If *note whitespace_split: 2e71. is set to ‘True’, this will have no effect. -- Attribute: shlex.whitespace Characters that will be considered whitespace and skipped. Whitespace bounds tokens. By default, includes space, tab, linefeed and carriage-return. -- Attribute: shlex.escape Characters that will be considered as escape. This will be only used in POSIX mode, and includes just ‘'\'’ by default. -- Attribute: shlex.quotes Characters that will be considered string quotes. The token accumulates until the same quote is encountered again (thus, different quote types protect each other as in the shell.) By default, includes ASCII single and double quotes. -- Attribute: shlex.escapedquotes Characters in *note quotes: 2e74. that will interpret escape characters defined in *note escape: 2e73. This is only used in POSIX mode, and includes just ‘'"'’ by default. -- Attribute: shlex.whitespace_split If ‘True’, tokens will only be split in whitespaces. This is useful, for example, for parsing command lines with *note shlex: 57a, getting tokens in a similar way to shell arguments. When used in combination with *note punctuation_chars: 2e70, tokens will be split on whitespace in addition to those characters. Changed in version 3.8: The *note punctuation_chars: 2e70. attribute was made compatible with the *note whitespace_split: 2e71. attribute. -- Attribute: shlex.infile The name of the current input file, as initially set at class instantiation time or stacked by later source requests. It may be useful to examine this when constructing error messages. -- Attribute: shlex.instream The input stream from which this *note shlex: 57a. instance is reading characters. -- Attribute: shlex.source This attribute is ‘None’ by default. If you assign a string to it, that string will be recognized as a lexical-level inclusion request similar to the ‘source’ keyword in various shells. That is, the immediately following token will be opened as a filename and input will be taken from that stream until EOF, at which point the *note close(): 1bdd. method of that stream will be called and the input source will again become the original input stream. Source requests may be stacked any number of levels deep. -- Attribute: shlex.debug If this attribute is numeric and ‘1’ or more, a *note shlex: 57a. instance will print verbose progress output on its behavior. If you need to use this, you can read the module source code to learn the details. -- Attribute: shlex.lineno Source line number (count of newlines seen so far plus one). -- Attribute: shlex.token The token buffer. It may be useful to examine this when catching exceptions. -- Attribute: shlex.eof Token used to determine end of file. This will be set to the empty string (‘''’), in non-POSIX mode, and to ‘None’ in POSIX mode. -- Attribute: shlex.punctuation_chars A read-only property. Characters that will be considered punctuation. Runs of punctuation characters will be returned as a single token. However, note that no semantic validity checking will be performed: for example, ‘>>>’ could be returned as a token, even though it may not be recognised as such by shells. New in version 3.6.  File: python.info, Node: Parsing Rules, Next: Improved Compatibility with Shells, Prev: shlex Objects, Up: shlex — Simple lexical analysis 5.24.3.2 Parsing Rules ...................... When operating in non-POSIX mode, *note shlex: 57a. will try to obey to the following rules. * Quote characters are not recognized within words (‘Do"Not"Separate’ is parsed as the single word ‘Do"Not"Separate’); * Escape characters are not recognized; * Enclosing characters in quotes preserve the literal value of all characters within the quotes; * Closing quotes separate words (‘"Do"Separate’ is parsed as ‘"Do"’ and ‘Separate’); * If *note whitespace_split: 2e71. is ‘False’, any character not declared to be a word character, whitespace, or a quote will be returned as a single-character token. If it is ‘True’, *note shlex: 57a. will only split words in whitespaces; * EOF is signaled with an empty string (‘''’); * It’s not possible to parse empty strings, even if quoted. When operating in POSIX mode, *note shlex: 57a. will try to obey to the following parsing rules. * Quotes are stripped out, and do not separate words (‘"Do"Not"Separate"’ is parsed as the single word ‘DoNotSeparate’); * Non-quoted escape characters (e.g. ‘'\'’) preserve the literal value of the next character that follows; * Enclosing characters in quotes which are not part of *note escapedquotes: 2e75. (e.g. ‘"'"’) preserve the literal value of all characters within the quotes; * Enclosing characters in quotes which are part of *note escapedquotes: 2e75. (e.g. ‘'"'’) preserves the literal value of all characters within the quotes, with the exception of the characters mentioned in *note escape: 2e73. The escape characters retain its special meaning only when followed by the quote in use, or the escape character itself. Otherwise the escape character will be considered a normal character. * EOF is signaled with a *note None: 157. value; * Quoted empty strings (‘''’) are allowed.  File: python.info, Node: Improved Compatibility with Shells, Prev: Parsing Rules, Up: shlex — Simple lexical analysis 5.24.3.3 Improved Compatibility with Shells ........................................... New in version 3.6. The *note shlex: e8. class provides compatibility with the parsing performed by common Unix shells like ‘bash’, ‘dash’, and ‘sh’. To take advantage of this compatibility, specify the ‘punctuation_chars’ argument in the constructor. This defaults to ‘False’, which preserves pre-3.6 behaviour. However, if it is set to ‘True’, then parsing of the characters ‘();<>|&’ is changed: any run of these characters is returned as a single token. While this is short of a full parser for shells (which would be out of scope for the standard library, given the multiplicity of shells out there), it does allow you to perform processing of command lines more easily than you could otherwise. To illustrate, you can see the difference in the following snippet: >>> import shlex >>> text = "a && b; c && d || e; f >'abc'; (def \"ghi\")" >>> s = shlex.shlex(text, posix=True) >>> s.whitespace_split = True >>> list(s) ['a', '&&', 'b;', 'c', '&&', 'd', '||', 'e;', 'f', '>abc;', '(def', 'ghi)'] >>> s = shlex.shlex(text, posix=True, punctuation_chars=True) >>> s.whitespace_split = True >>> list(s) ['a', '&&', 'b', ';', 'c', '&&', 'd', '||', 'e', ';', 'f', '>', 'abc', ';', '(', 'def', 'ghi', ')'] Of course, tokens will be returned which are not valid for shells, and you’ll need to implement your own error checks on the returned tokens. Instead of passing ‘True’ as the value for the punctuation_chars parameter, you can pass a string with specific characters, which will be used to determine which characters constitute punctuation. For example: >>> import shlex >>> s = shlex.shlex("a && b || c", punctuation_chars="|") >>> list(s) ['a', '&', '&', 'b', '||', 'c'] Note: When ‘punctuation_chars’ is specified, the *note wordchars: 2e64. attribute is augmented with the characters ‘~-./*?=’. That is because these characters can appear in file names (including wildcards) and command-line arguments (e.g. ‘--color=auto’). Hence: >>> import shlex >>> s = shlex.shlex('~/a && b-c --color=auto || d *.py?', ... punctuation_chars=True) >>> list(s) ['~/a', '&&', 'b-c', '--color=auto', '||', 'd', '*.py?'] However, to match the shell as closely as possible, it is recommended to always use ‘posix’ and *note whitespace_split: 2e71. when using *note punctuation_chars: 2e70, which will negate *note wordchars: 2e64. entirely. For best effect, ‘punctuation_chars’ should be set in conjunction with ‘posix=True’. (Note that ‘posix=False’ is the default for *note shlex: 57a.)  File: python.info, Node: Graphical User Interfaces with Tk, Next: Development Tools, Prev: Program Frameworks, Up: The Python Standard Library 5.25 Graphical User Interfaces with Tk ====================================== Tk/Tcl has long been an integral part of Python. It provides a robust and platform independent windowing toolkit, that is available to Python programmers using the *note tkinter: 10c. package, and its extension, the *note tkinter.tix: 10e. and the *note tkinter.ttk: 10f. modules. The *note tkinter: 10c. package is a thin object-oriented layer on top of Tcl/Tk. To use *note tkinter: 10c, you don’t need to write Tcl code, but you will need to consult the Tk documentation, and occasionally the Tcl documentation. *note tkinter: 10c. is a set of wrappers that implement the Tk widgets as Python classes. In addition, the internal module ‘_tkinter’ provides a threadsafe mechanism which allows Python and Tcl to interact. *note tkinter: 10c.’s chief virtues are that it is fast, and that it usually comes bundled with Python. Although its standard documentation is weak, good material is available, which includes: references, tutorials, a book and others. *note tkinter: 10c. is also famous for having an outdated look and feel, which has been vastly improved in Tk 8.5. Nevertheless, there are many other GUI libraries that you could be interested in. For more information about alternatives, see the *note Other Graphical User Interface Packages: 2e80. section. * Menu: * tkinter — Python interface to Tcl/Tk:: * tkinter.ttk — Tk themed widgets: tkinter ttk — Tk themed widgets. * tkinter.tix — Extension widgets for Tk: tkinter tix — Extension widgets for Tk. * tkinter.scrolledtext — Scrolled Text Widget: tkinter scrolledtext — Scrolled Text Widget. * IDLE: IDLE<3>. * Other Graphical User Interface Packages::  File: python.info, Node: tkinter — Python interface to Tcl/Tk, Next: tkinter ttk — Tk themed widgets, Up: Graphical User Interfaces with Tk 5.25.1 ‘tkinter’ — Python interface to Tcl/Tk --------------------------------------------- `Source code:' Lib/tkinter/__init__.py(1) __________________________________________________________________ The *note tkinter: 10c. package (“Tk interface”) is the standard Python interface to the Tk GUI toolkit. Both Tk and *note tkinter: 10c. are available on most Unix platforms, as well as on Windows systems. (Tk itself is not part of Python; it is maintained at ActiveState.) Running ‘python -m tkinter’ from the command line should open a window demonstrating a simple Tk interface, letting you know that *note tkinter: 10c. is properly installed on your system, and also showing what version of Tcl/Tk is installed, so you can read the Tcl/Tk documentation specific to that version. See also ........ Tkinter documentation: Python Tkinter Resources(2) The Python Tkinter Topic Guide provides a great deal of information on using Tk from Python and links to other sources of information on Tk. TKDocs(3) Extensive tutorial plus friendlier widget pages for some of the widgets. Tkinter 8.5 reference: a GUI for Python(4) On-line reference material. Tkinter docs from effbot(5) Online reference for tkinter supported by effbot.org. Programming Python(6) Book by Mark Lutz, has excellent coverage of Tkinter. Modern Tkinter for Busy Python Developers(7) Book by Mark Roseman about building attractive and modern graphical user interfaces with Python and Tkinter. Python and Tkinter Programming(8) Book by John Grayson (ISBN 1-884777-81-3). Tcl/Tk documentation: Tk commands(9) Most commands are available as *note tkinter: 10c. or *note tkinter.ttk: 10f. classes. Change ‘8.6’ to match the version of your Tcl/Tk installation. Tcl/Tk recent man pages(10) Recent Tcl/Tk manuals on www.tcl.tk. ActiveState Tcl Home Page(11) The Tk/Tcl development is largely taking place at ActiveState. Tcl and the Tk Toolkit(12) Book by John Ousterhout, the inventor of Tcl. Practical Programming in Tcl and Tk(13) Brent Welch’s encyclopedic book. * Menu: * Tkinter Modules:: * Tkinter Life Preserver:: * A (Very) Quick Look at Tcl/Tk: A Very Quick Look at Tcl/Tk. * Mapping Basic Tk into Tkinter:: * How Tk and Tkinter are Related:: * Handy Reference:: * File Handlers:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tkinter/__init__.py (2) https://wiki.python.org/moin/TkInter (3) http://www.tkdocs.com/ (4) https://www.tkdocs.com/shipman/ (5) http://effbot.org/tkinterbook/ (6) http://learning-python.com/about-pp4e.html (7) https://www.amazon.com/Modern-Tkinter-Python-Developers-ebook/dp/B0071QDNLO/ (8) https://www.manning.com/books/python-and-tkinter-programming (9) https://www.tcl.tk/man/tcl8.6/TkCmd/contents.htm (10) https://www.tcl.tk/doc/ (11) https://tcl.tk (12) https://www.amazon.com/exec/obidos/ASIN/020163337X (13) http://www.beedub.com/book/  File: python.info, Node: Tkinter Modules, Next: Tkinter Life Preserver, Up: tkinter — Python interface to Tcl/Tk 5.25.1.1 Tkinter Modules ........................ Most of the time, *note tkinter: 10c. is all you really need, but a number of additional modules are available as well. The Tk interface is located in a binary module named ‘_tkinter’. This module contains the low-level interface to Tk, and should never be used directly by application programmers. It is usually a shared library (or DLL), but might in some cases be statically linked with the Python interpreter. In addition to the Tk interface module, *note tkinter: 10c. includes a number of Python modules, ‘tkinter.constants’ being one of the most important. Importing *note tkinter: 10c. will automatically import ‘tkinter.constants’, so, usually, to use Tkinter all you need is a simple import statement: import tkinter Or, more often: from tkinter import * -- Class: tkinter.Tk (screenName=None, baseName=None, className='Tk', useTk=1) The *note Tk: 2e84. class is instantiated without arguments. This creates a toplevel widget of Tk which usually is the main window of an application. Each instance has its own associated Tcl interpreter. -- Function: tkinter.Tcl (screenName=None, baseName=None, className='Tk', useTk=0) The *note Tcl(): 2e85. function is a factory function which creates an object much like that created by the *note Tk: 2e84. class, except that it does not initialize the Tk subsystem. This is most often useful when driving the Tcl interpreter in an environment where one doesn’t want to create extraneous toplevel windows, or where one cannot (such as Unix/Linux systems without an X server). An object created by the *note Tcl(): 2e85. object can have a Toplevel window created (and the Tk subsystem initialized) by calling its ‘loadtk()’ method. Other modules that provide Tk support include: *note tkinter.scrolledtext: 10d. Text widget with a vertical scroll bar built in. ‘tkinter.colorchooser’ Dialog to let the user choose a color. ‘tkinter.commondialog’ Base class for the dialogs defined in the other modules listed here. ‘tkinter.filedialog’ Common dialogs to allow the user to specify a file to open or save. ‘tkinter.font’ Utilities to help work with fonts. ‘tkinter.messagebox’ Access to standard Tk dialog boxes. ‘tkinter.simpledialog’ Basic dialogs and convenience functions. ‘tkinter.dnd’ Drag-and-drop support for *note tkinter: 10c. This is experimental and should become deprecated when it is replaced with the Tk DND. *note turtle: 116. Turtle graphics in a Tk window.  File: python.info, Node: Tkinter Life Preserver, Next: A Very Quick Look at Tcl/Tk, Prev: Tkinter Modules, Up: tkinter — Python interface to Tcl/Tk 5.25.1.2 Tkinter Life Preserver ............................... This section is not designed to be an exhaustive tutorial on either Tk or Tkinter. Rather, it is intended as a stop gap, providing some introductory orientation on the system. Credits: * Tk was written by John Ousterhout while at Berkeley. * Tkinter was written by Steen Lumholt and Guido van Rossum. * This Life Preserver was written by Matt Conway at the University of Virginia. * The HTML rendering, and some liberal editing, was produced from a FrameMaker version by Ken Manheimer. * Fredrik Lundh elaborated and revised the class interface descriptions, to get them current with Tk 4.2. * Mike Clarkson converted the documentation to LaTeX, and compiled the User Interface chapter of the reference manual. * Menu: * How To Use This Section:: * A Simple Hello World Program::  File: python.info, Node: How To Use This Section, Next: A Simple Hello World Program, Up: Tkinter Life Preserver 5.25.1.3 How To Use This Section ................................ This section is designed in two parts: the first half (roughly) covers background material, while the second half can be taken to the keyboard as a handy reference. When trying to answer questions of the form “how do I do blah”, it is often best to find out how to do “blah” in straight Tk, and then convert this back into the corresponding *note tkinter: 10c. call. Python programmers can often guess at the correct Python command by looking at the Tk documentation. This means that in order to use Tkinter, you will have to know a little bit about Tk. This document can’t fulfill that role, so the best we can do is point you to the best documentation that exists. Here are some hints: * The authors strongly suggest getting a copy of the Tk man pages. Specifically, the man pages in the ‘manN’ directory are most useful. The ‘man3’ man pages describe the C interface to the Tk library and thus are not especially helpful for script writers. * Addison-Wesley publishes a book called Tcl and the Tk Toolkit by John Ousterhout (ISBN 0-201-63337-X) which is a good introduction to Tcl and Tk for the novice. The book is not exhaustive, and for many details it defers to the man pages. * ‘tkinter/__init__.py’ is a last resort for most, but can be a good place to go when nothing else makes sense.  File: python.info, Node: A Simple Hello World Program, Prev: How To Use This Section, Up: Tkinter Life Preserver 5.25.1.4 A Simple Hello World Program ..................................... import tkinter as tk class Application(tk.Frame): def __init__(self, master=None): super().__init__(master) self.master = master self.pack() self.create_widgets() def create_widgets(self): self.hi_there = tk.Button(self) self.hi_there["text"] = "Hello World\n(click me)" self.hi_there["command"] = self.say_hi self.hi_there.pack(side="top") self.quit = tk.Button(self, text="QUIT", fg="red", command=self.master.destroy) self.quit.pack(side="bottom") def say_hi(self): print("hi there, everyone!") root = tk.Tk() app = Application(master=root) app.mainloop()  File: python.info, Node: A Very Quick Look at Tcl/Tk, Next: Mapping Basic Tk into Tkinter, Prev: Tkinter Life Preserver, Up: tkinter — Python interface to Tcl/Tk 5.25.1.5 A (Very) Quick Look at Tcl/Tk ...................................... The class hierarchy looks complicated, but in actual practice, application programmers almost always refer to the classes at the very bottom of the hierarchy. Notes: * These classes are provided for the purposes of organizing certain functions under one namespace. They aren’t meant to be instantiated independently. * The *note Tk: 2e84. class is meant to be instantiated only once in an application. Application programmers need not instantiate one explicitly, the system creates one whenever any of the other classes are instantiated. * The ‘Widget’ class is not meant to be instantiated, it is meant only for subclassing to make “real” widgets (in C++, this is called an ‘abstract class’). To make use of this reference material, there will be times when you will need to know how to read short passages of Tk and how to identify the various parts of a Tk command. (See section *note Mapping Basic Tk into Tkinter: 2e8a. for the *note tkinter: 10c. equivalents of what’s below.) Tk scripts are Tcl programs. Like all Tcl programs, Tk scripts are just lists of tokens separated by spaces. A Tk widget is just its `class', the `options' that help configure it, and the `actions' that make it do useful things. To make a widget in Tk, the command is always of the form: classCommand newPathname options `classCommand' denotes which kind of widget to make (a button, a label, a menu…) `newPathname' is the new name for this widget. All names in Tk must be unique. To help enforce this, widgets in Tk are named with `pathnames', just like files in a file system. The top level widget, the `root', is called ‘.’ (period) and children are delimited by more periods. For example, ‘.myApp.controlPanel.okButton’ might be the name of a widget. `options' configure the widget’s appearance and in some cases, its behavior. The options come in the form of a list of flags and values. Flags are preceded by a ‘-‘, like Unix shell command flags, and values are put in quotes if they are more than one word. For example: button .fred -fg red -text "hi there" ^ ^ \______________________/ | | | class new options command widget (-opt val -opt val ...) Once created, the pathname to the widget becomes a new command. This new `widget command' is the programmer’s handle for getting the new widget to perform some `action'. In C, you’d express this as someAction(fred, someOptions), in C++, you would express this as fred.someAction(someOptions), and in Tk, you say: .fred someAction someOptions Note that the object name, ‘.fred’, starts with a dot. As you’d expect, the legal values for `someAction' will depend on the widget’s class: ‘.fred disable’ works if fred is a button (fred gets greyed out), but does not work if fred is a label (disabling of labels is not supported in Tk). The legal values of `someOptions' is action dependent. Some actions, like ‘disable’, require no arguments, others, like a text-entry box’s ‘delete’ command, would need arguments to specify what range of text to delete.  File: python.info, Node: Mapping Basic Tk into Tkinter, Next: How Tk and Tkinter are Related, Prev: A Very Quick Look at Tcl/Tk, Up: tkinter — Python interface to Tcl/Tk 5.25.1.6 Mapping Basic Tk into Tkinter ...................................... Class commands in Tk correspond to class constructors in Tkinter. button .fred =====> fred = Button() The master of an object is implicit in the new name given to it at creation time. In Tkinter, masters are specified explicitly. button .panel.fred =====> fred = Button(panel) The configuration options in Tk are given in lists of hyphened tags followed by values. In Tkinter, options are specified as keyword-arguments in the instance constructor, and keyword-args for configure calls or as instance indices, in dictionary style, for established instances. See section *note Setting Options: 2e8c. on setting options. button .fred -fg red =====> fred = Button(panel, fg="red") .fred configure -fg red =====> fred["fg"] = red OR ==> fred.config(fg="red") In Tk, to perform an action on a widget, use the widget name as a command, and follow it with an action name, possibly with arguments (options). In Tkinter, you call methods on the class instance to invoke actions on the widget. The actions (methods) that a given widget can perform are listed in ‘tkinter/__init__.py’. .fred invoke =====> fred.invoke() To give a widget to the packer (geometry manager), you call pack with optional arguments. In Tkinter, the Pack class holds all this functionality, and the various forms of the pack command are implemented as methods. All widgets in *note tkinter: 10c. are subclassed from the Packer, and so inherit all the packing methods. See the *note tkinter.tix: 10e. module documentation for additional information on the Form geometry manager. pack .fred -side left =====> fred.pack(side="left")  File: python.info, Node: How Tk and Tkinter are Related, Next: Handy Reference, Prev: Mapping Basic Tk into Tkinter, Up: tkinter — Python interface to Tcl/Tk 5.25.1.7 How Tk and Tkinter are Related ....................................... From the top down: Your App Here (Python) A Python application makes a *note tkinter: 10c. call. tkinter (Python Package) This call (say, for example, creating a button widget), is implemented in the *note tkinter: 10c. package, which is written in Python. This Python function will parse the commands and the arguments and convert them into a form that makes them look as if they had come from a Tk script instead of a Python script. _tkinter (C) These commands and their arguments will be passed to a C function in the ‘_tkinter’ - note the underscore - extension module. Tk Widgets (C and Tcl) This C function is able to make calls into other C modules, including the C functions that make up the Tk library. Tk is implemented in C and some Tcl. The Tcl part of the Tk widgets is used to bind certain default behaviors to widgets, and is executed once at the point where the Python *note tkinter: 10c. package is imported. (The user never sees this stage). Tk (C) The Tk part of the Tk Widgets implement the final mapping to … Xlib (C) the Xlib library to draw graphics on the screen.  File: python.info, Node: Handy Reference, Next: File Handlers, Prev: How Tk and Tkinter are Related, Up: tkinter — Python interface to Tcl/Tk 5.25.1.8 Handy Reference ........................ * Menu: * Setting Options:: * The Packer:: * Packer Options:: * Coupling Widget Variables:: * The Window Manager:: * Tk Option Data Types:: * Bindings and Events:: * The index Parameter:: * Images::  File: python.info, Node: Setting Options, Next: The Packer, Up: Handy Reference 5.25.1.9 Setting Options ........................ Options control things like the color and border width of a widget. Options can be set in three ways: At object creation time, using keyword arguments fred = Button(self, fg="red", bg="blue") After object creation, treating the option name like a dictionary index fred["fg"] = "red" fred["bg"] = "blue" Use the config() method to update multiple attrs subsequent to object creation fred.config(fg="red", bg="blue") For a complete explanation of a given option and its behavior, see the Tk man pages for the widget in question. Note that the man pages list “STANDARD OPTIONS” and “WIDGET SPECIFIC OPTIONS” for each widget. The former is a list of options that are common to many widgets, the latter are the options that are idiosyncratic to that particular widget. The Standard Options are documented on the ‘options(3)’ man page. No distinction between standard and widget-specific options is made in this document. Some options don’t apply to some kinds of widgets. Whether a given widget responds to a particular option depends on the class of the widget; buttons have a ‘command’ option, labels do not. The options supported by a given widget are listed in that widget’s man page, or can be queried at runtime by calling the ‘config()’ method without arguments, or by calling the ‘keys()’ method on that widget. The return value of these calls is a dictionary whose key is the name of the option as a string (for example, ‘'relief'’) and whose values are 5-tuples. Some options, like ‘bg’ are synonyms for common options with long names (‘bg’ is shorthand for “background”). Passing the ‘config()’ method the name of a shorthand option will return a 2-tuple, not 5-tuple. The 2-tuple passed back will contain the name of the synonym and the “real” option (such as ‘('bg', 'background')’). Index Meaning Example --------------------------------------------------------------------- 0 option name ‘'relief'’ 1 option name for database lookup ‘'relief'’ 2 option class for database lookup ‘'Relief'’ 3 default value ‘'raised'’ 4 current value ‘'groove'’ Example: >>> print(fred.config()) {'relief': ('relief', 'relief', 'Relief', 'raised', 'groove')} Of course, the dictionary printed will include all the options available and their values. This is meant only as an example.  File: python.info, Node: The Packer, Next: Packer Options, Prev: Setting Options, Up: Handy Reference 5.25.1.10 The Packer .................... The packer is one of Tk’s geometry-management mechanisms. Geometry managers are used to specify the relative positioning of widgets within their container - their mutual `master'. In contrast to the more cumbersome `placer' (which is used less commonly, and we do not cover here), the packer takes qualitative relationship specification - `above', `to the left of', `filling', etc - and works everything out to determine the exact placement coordinates for you. The size of any `master' widget is determined by the size of the “slave widgets” inside. The packer is used to control where slave widgets appear inside the master into which they are packed. You can pack widgets into frames, and frames into other frames, in order to achieve the kind of layout you desire. Additionally, the arrangement is dynamically adjusted to accommodate incremental changes to the configuration, once it is packed. Note that widgets do not appear until they have had their geometry specified with a geometry manager. It’s a common early mistake to leave out the geometry specification, and then be surprised when the widget is created but nothing appears. A widget will appear only after it has had, for example, the packer’s ‘pack()’ method applied to it. The pack() method can be called with keyword-option/value pairs that control where the widget is to appear within its container, and how it is to behave when the main application window is resized. Here are some examples: fred.pack() # defaults to side = "top" fred.pack(side="left") fred.pack(expand=1)  File: python.info, Node: Packer Options, Next: Coupling Widget Variables, Prev: The Packer, Up: Handy Reference 5.25.1.11 Packer Options ........................ For more extensive information on the packer and the options that it can take, see the man pages and page 183 of John Ousterhout’s book. anchor Anchor type. Denotes where the packer is to place each slave in its parcel. expand Boolean, ‘0’ or ‘1’. fill Legal values: ‘'x'’, ‘'y'’, ‘'both'’, ‘'none'’. ipadx and ipady A distance - designating internal padding on each side of the slave widget. padx and pady A distance - designating external padding on each side of the slave widget. side Legal values are: ‘'left'’, ‘'right'’, ‘'top'’, ‘'bottom'’.  File: python.info, Node: Coupling Widget Variables, Next: The Window Manager, Prev: Packer Options, Up: Handy Reference 5.25.1.12 Coupling Widget Variables ................................... The current-value setting of some widgets (like text entry widgets) can be connected directly to application variables by using special options. These options are ‘variable’, ‘textvariable’, ‘onvalue’, ‘offvalue’, and ‘value’. This connection works both ways: if the variable changes for any reason, the widget it’s connected to will be updated to reflect the new value. Unfortunately, in the current implementation of *note tkinter: 10c. it is not possible to hand over an arbitrary Python variable to a widget through a ‘variable’ or ‘textvariable’ option. The only kinds of variables for which this works are variables that are subclassed from a class called Variable, defined in *note tkinter: 10c. There are many useful subclasses of Variable already defined: ‘StringVar’, ‘IntVar’, ‘DoubleVar’, and ‘BooleanVar’. To read the current value of such a variable, call the ‘get()’ method on it, and to change its value you call the ‘set()’ method. If you follow this protocol, the widget will always track the value of the variable, with no further intervention on your part. For example: import tkinter as tk class App(tk.Frame): def __init__(self, master): super().__init__(master) self.pack() self.entrythingy = tk.Entry() self.entrythingy.pack() # Create the application variable. self.contents = tk.StringVar() # Set it to some value. self.contents.set("this is a variable") # Tell the entry widget to watch this variable. self.entrythingy["textvariable"] = self.contents # Define a callback for when the user hits return. # It prints the current value of the variable. self.entrythingy.bind('<Key-Return>', self.print_contents) def print_contents(self, event): print("Hi. The current entry content is:", self.contents.get()) root = tk.Tk() myapp = App(root) myapp.mainloop()  File: python.info, Node: The Window Manager, Next: Tk Option Data Types, Prev: Coupling Widget Variables, Up: Handy Reference 5.25.1.13 The Window Manager ............................ In Tk, there is a utility command, ‘wm’, for interacting with the window manager. Options to the ‘wm’ command allow you to control things like titles, placement, icon bitmaps, and the like. In *note tkinter: 10c, these commands have been implemented as methods on the ‘Wm’ class. Toplevel widgets are subclassed from the ‘Wm’ class, and so can call the ‘Wm’ methods directly. To get at the toplevel window that contains a given widget, you can often just refer to the widget’s master. Of course if the widget has been packed inside of a frame, the master won’t represent a toplevel window. To get at the toplevel window that contains an arbitrary widget, you can call the ‘_root()’ method. This method begins with an underscore to denote the fact that this function is part of the implementation, and not an interface to Tk functionality. Here are some examples of typical usage: import tkinter as tk class App(tk.Frame): def __init__(self, master=None): super().__init__(master) self.pack() # create the application myapp = App() # # here are method calls to the window manager class # myapp.master.title("My Do-Nothing Application") myapp.master.maxsize(1000, 400) # start the program myapp.mainloop()  File: python.info, Node: Tk Option Data Types, Next: Bindings and Events, Prev: The Window Manager, Up: Handy Reference 5.25.1.14 Tk Option Data Types .............................. anchor Legal values are points of the compass: ‘"n"’, ‘"ne"’, ‘"e"’, ‘"se"’, ‘"s"’, ‘"sw"’, ‘"w"’, ‘"nw"’, and also ‘"center"’. bitmap There are eight built-in, named bitmaps: ‘'error'’, ‘'gray25'’, ‘'gray50'’, ‘'hourglass'’, ‘'info'’, ‘'questhead'’, ‘'question'’, ‘'warning'’. To specify an X bitmap filename, give the full path to the file, preceded with an ‘@’, as in ‘"@/usr/contrib/bitmap/gumby.bit"’. boolean You can pass integers 0 or 1 or the strings ‘"yes"’ or ‘"no"’. callback This is any Python function that takes no arguments. For example: def print_it(): print("hi there") fred["command"] = print_it color Colors can be given as the names of X colors in the rgb.txt file, or as strings representing RGB values in 4 bit: ‘"#RGB"’, 8 bit: ‘"#RRGGBB"’, 12 bit” ‘"#RRRGGGBBB"’, or 16 bit ‘"#RRRRGGGGBBBB"’ ranges, where R,G,B here represent any legal hex digit. See page 160 of Ousterhout’s book for details. cursor The standard X cursor names from ‘cursorfont.h’ can be used, without the ‘XC_’ prefix. For example to get a hand cursor (‘XC_hand2’), use the string ‘"hand2"’. You can also specify a bitmap and mask file of your own. See page 179 of Ousterhout’s book. distance Screen distances can be specified in either pixels or absolute distances. Pixels are given as numbers and absolute distances as strings, with the trailing character denoting units: ‘c’ for centimetres, ‘i’ for inches, ‘m’ for millimetres, ‘p’ for printer’s points. For example, 3.5 inches is expressed as ‘"3.5i"’. font Tk uses a list font name format, such as ‘{courier 10 bold}’. Font sizes with positive numbers are measured in points; sizes with negative numbers are measured in pixels. geometry This is a string of the form ‘widthxheight’, where width and height are measured in pixels for most widgets (in characters for widgets displaying text). For example: ‘fred["geometry"] = "200x100"’. justify Legal values are the strings: ‘"left"’, ‘"center"’, ‘"right"’, and ‘"fill"’. region This is a string with four space-delimited elements, each of which is a legal distance (see above). For example: ‘"2 3 4 5"’ and ‘"3i 2i 4.5i 2i"’ and ‘"3c 2c 4c 10.43c"’ are all legal regions. relief Determines what the border style of a widget will be. Legal values are: ‘"raised"’, ‘"sunken"’, ‘"flat"’, ‘"groove"’, and ‘"ridge"’. scrollcommand This is almost always the ‘set()’ method of some scrollbar widget, but can be any widget method that takes a single argument. wrap: Must be one of: ‘"none"’, ‘"char"’, or ‘"word"’.  File: python.info, Node: Bindings and Events, Next: The index Parameter, Prev: Tk Option Data Types, Up: Handy Reference 5.25.1.15 Bindings and Events ............................. The bind method from the widget command allows you to watch for certain events and to have a callback function trigger when that event type occurs. The form of the bind method is: def bind(self, sequence, func, add=''): where: sequence is a string that denotes the target kind of event. (See the bind man page and page 201 of John Ousterhout’s book for details). func is a Python function, taking one argument, to be invoked when the event occurs. An Event instance will be passed as the argument. (Functions deployed this way are commonly known as `callbacks'.) add is optional, either ‘''’ or ‘'+'’. Passing an empty string denotes that this binding is to replace any other bindings that this event is associated with. Passing a ‘'+'’ means that this function is to be added to the list of functions bound to this event type. For example: def turn_red(self, event): event.widget["activeforeground"] = "red" self.button.bind("<Enter>", self.turn_red) Notice how the widget field of the event is being accessed in the ‘turn_red()’ callback. This field contains the widget that caught the X event. The following table lists the other event fields you can access, and how they are denoted in Tk, which can be useful when referring to the Tk man pages. Tk Tkinter Event Field Tk Tkinter Event Field ---------------------------------------------------------------------- %f focus %A char %h height %E send_event %k keycode %K keysym %s state %N keysym_num %t time %T type %w width %W widget %x x %X x_root %y y %Y y_root  File: python.info, Node: The index Parameter, Next: Images, Prev: Bindings and Events, Up: Handy Reference 5.25.1.16 The index Parameter ............................. A number of widgets require “index” parameters to be passed. These are used to point at a specific place in a Text widget, or to particular characters in an Entry widget, or to particular menu items in a Menu widget. Entry widget indexes (index, view index, etc.) Entry widgets have options that refer to character positions in the text being displayed. You can use these *note tkinter: 10c. functions to access these special points in text widgets: Text widget indexes The index notation for Text widgets is very rich and is best described in the Tk man pages. Menu indexes (menu.invoke(), menu.entryconfig(), etc.) Some options and methods for menus manipulate specific menu entries. Anytime a menu index is needed for an option or a parameter, you may pass in: * an integer which refers to the numeric position of the entry in the widget, counted from the top, starting with 0; * the string ‘"active"’, which refers to the menu position that is currently under the cursor; * the string ‘"last"’ which refers to the last menu item; * An integer preceded by ‘@’, as in ‘@6’, where the integer is interpreted as a y pixel coordinate in the menu’s coordinate system; * the string ‘"none"’, which indicates no menu entry at all, most often used with menu.activate() to deactivate all entries, and finally, * a text string that is pattern matched against the label of the menu entry, as scanned from the top of the menu to the bottom. Note that this index type is considered after all the others, which means that matches for menu items labelled ‘last’, ‘active’, or ‘none’ may be interpreted as the above literals, instead.  File: python.info, Node: Images, Prev: The index Parameter, Up: Handy Reference 5.25.1.17 Images ................ Images of different formats can be created through the corresponding subclass of ‘tkinter.Image’: * ‘BitmapImage’ for images in XBM format. * ‘PhotoImage’ for images in PGM, PPM, GIF and PNG formats. The latter is supported starting with Tk 8.6. Either type of image is created through either the ‘file’ or the ‘data’ option (other options are available as well). The image object can then be used wherever an ‘image’ option is supported by some widget (e.g. labels, buttons, menus). In these cases, Tk will not keep a reference to the image. When the last Python reference to the image object is deleted, the image data is deleted as well, and Tk will display an empty box wherever the image was used. See also ........ The Pillow(1) package adds support for formats such as BMP, JPEG, TIFF, and WebP, among others. ---------- Footnotes ---------- (1) http://python-pillow.org/  File: python.info, Node: File Handlers, Prev: Handy Reference, Up: tkinter — Python interface to Tcl/Tk 5.25.1.18 File Handlers ....................... Tk allows you to register and unregister a callback function which will be called from the Tk mainloop when I/O is possible on a file descriptor. Only one handler may be registered per file descriptor. Example code: import tkinter widget = tkinter.Tk() mask = tkinter.READABLE | tkinter.WRITABLE widget.tk.createfilehandler(file, mask, callback) ... widget.tk.deletefilehandler(file) This feature is not available on Windows. Since you don’t know how many bytes are available for reading, you may not want to use the *note BufferedIOBase: 588. or *note TextIOBase: c39. *note read(): 1a22. or *note readline(): 13ae. methods, since these will insist on reading a predefined number of bytes. For sockets, the *note recv(): 677. or *note recvfrom(): 678. methods will work fine; for other files, use raw reads or ‘os.read(file.fileno(), maxbytecount)’. -- Method: Widget.tk.createfilehandler (file, mask, func) Registers the file handler callback function `func'. The `file' argument may either be an object with a *note fileno(): 1bdb. method (such as a file or socket object), or an integer file descriptor. The `mask' argument is an ORed combination of any of the three constants below. The callback is called as follows: callback(file, mask) -- Method: Widget.tk.deletefilehandler (file) Unregisters a file handler. -- Data: tkinter.READABLE -- Data: tkinter.WRITABLE -- Data: tkinter.EXCEPTION Constants used in the `mask' arguments.  File: python.info, Node: tkinter ttk — Tk themed widgets, Next: tkinter tix — Extension widgets for Tk, Prev: tkinter — Python interface to Tcl/Tk, Up: Graphical User Interfaces with Tk 5.25.2 ‘tkinter.ttk’ — Tk themed widgets ---------------------------------------- `Source code:' Lib/tkinter/ttk.py(1) __________________________________________________________________ The *note tkinter.ttk: 10f. module provides access to the Tk themed widget set, introduced in Tk 8.5. If Python has not been compiled against Tk 8.5, this module can still be accessed if `Tile' has been installed. The former method using Tk 8.5 provides additional benefits including anti-aliased font rendering under X11 and window transparency (requiring a composition window manager on X11). The basic idea for *note tkinter.ttk: 10f. is to separate, to the extent possible, the code implementing a widget’s behavior from the code implementing its appearance. See also ........ Tk Widget Styling Support(2) A document introducing theming support for Tk * Menu: * Using Ttk:: * Ttk Widgets:: * Widget:: * Combobox:: * Spinbox:: * Notebook:: * Progressbar:: * Separator:: * Sizegrip:: * Treeview:: * Ttk Styling:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tkinter/ttk.py (2) https://core.tcl.tk/tips/doc/trunk/tip/48.md  File: python.info, Node: Using Ttk, Next: Ttk Widgets, Up: tkinter ttk — Tk themed widgets 5.25.2.1 Using Ttk .................. To start using Ttk, import its module: from tkinter import ttk To override the basic Tk widgets, the import should follow the Tk import: from tkinter import * from tkinter.ttk import * That code causes several *note tkinter.ttk: 10f. widgets (‘Button’, ‘Checkbutton’, ‘Entry’, ‘Frame’, ‘Label’, ‘LabelFrame’, ‘Menubutton’, ‘PanedWindow’, ‘Radiobutton’, ‘Scale’ and ‘Scrollbar’) to automatically replace the Tk widgets. This has the direct benefit of using the new widgets which gives a better look and feel across platforms; however, the replacement widgets are not completely compatible. The main difference is that widget options such as “fg”, “bg” and others related to widget styling are no longer present in Ttk widgets. Instead, use the ‘ttk.Style’ class for improved styling effects. See also ........ Converting existing applications to use Tile widgets(1) A monograph (using Tcl terminology) about differences typically encountered when moving applications to use the new widgets. ---------- Footnotes ---------- (1) http://tktable.sourceforge.net/tile/doc/converting.txt  File: python.info, Node: Ttk Widgets, Next: Widget, Prev: Using Ttk, Up: tkinter ttk — Tk themed widgets 5.25.2.2 Ttk Widgets .................... Ttk comes with 18 widgets, twelve of which already existed in tkinter: ‘Button’, ‘Checkbutton’, ‘Entry’, ‘Frame’, ‘Label’, ‘LabelFrame’, ‘Menubutton’, ‘PanedWindow’, ‘Radiobutton’, ‘Scale’, ‘Scrollbar’, and *note Spinbox: 3fd. The other six are new: *note Combobox: 2ea3, *note Notebook: 2ea4, *note Progressbar: 2ea5, ‘Separator’, ‘Sizegrip’ and *note Treeview: 2bd. And all them are subclasses of *note Widget: 2ea6. Using the Ttk widgets gives the application an improved look and feel. As discussed above, there are differences in how the styling is coded. Tk code: l1 = tkinter.Label(text="Test", fg="black", bg="white") l2 = tkinter.Label(text="Test", fg="black", bg="white") Ttk code: style = ttk.Style() style.configure("BW.TLabel", foreground="black", background="white") l1 = ttk.Label(text="Test", style="BW.TLabel") l2 = ttk.Label(text="Test", style="BW.TLabel") For more information about *note TtkStyling: 2ea7, see the *note Style: 2ea8. class documentation.  File: python.info, Node: Widget, Next: Combobox, Prev: Ttk Widgets, Up: tkinter ttk — Tk themed widgets 5.25.2.3 Widget ............... ‘ttk.Widget’ defines standard options and methods supported by Tk themed widgets and is not supposed to be directly instantiated. * Menu: * Standard Options:: * Scrollable Widget Options:: * Label Options:: * Compatibility Options:: * Widget States:: * ttk.Widget: ttk Widget.  File: python.info, Node: Standard Options, Next: Scrollable Widget Options, Up: Widget 5.25.2.4 Standard Options ......................... All the ‘ttk’ Widgets accepts the following options: Option Description ----------------------------------------------------------------------------------- class Specifies the window class. The class is used when querying the option database for the window’s other options, to determine the default bindtags for the window, and to select the widget’s default layout and style. This option is read-only, and may only be specified when the window is created. cursor Specifies the mouse cursor to be used for the widget. If set to the empty string (the default), the cursor is inherited for the parent widget. takefocus Determines whether the window accepts the focus during keyboard traversal. 0, 1 or an empty string is returned. If 0 is returned, it means that the window should be skipped entirely during keyboard traversal. If 1, it means that the window should receive the input focus as long as it is viewable. And an empty string means that the traversal scripts make the decision about whether or not to focus on the window. style May be used to specify a custom widget style.  File: python.info, Node: Scrollable Widget Options, Next: Label Options, Prev: Standard Options, Up: Widget 5.25.2.5 Scrollable Widget Options .................................. The following options are supported by widgets that are controlled by a scrollbar. Option Description ----------------------------------------------------------------------------------- xscrollcommand Used to communicate with horizontal scrollbars. When the view in the widget’s window change, the widget will generate a Tcl command based on the scrollcommand. Usually this option consists of the method ‘Scrollbar.set()’ of some scrollbar. This will cause the scrollbar to be updated whenever the view in the window changes. yscrollcommand Used to communicate with vertical scrollbars. For some more information, see above.  File: python.info, Node: Label Options, Next: Compatibility Options, Prev: Scrollable Widget Options, Up: Widget 5.25.2.6 Label Options ...................... The following options are supported by labels, buttons and other button-like widgets. Option Description ----------------------------------------------------------------------------------- text Specifies a text string to be displayed inside the widget. textvariable Specifies a name whose value will be used in place of the text option resource. underline If set, specifies the index (0-based) of a character to underline in the text string. The underline character is used for mnemonic activation. image Specifies an image to display. This is a list of 1 or more elements. The first element is the default image name. The rest of the list if a sequence of statespec/value pairs as defined by *note Style.map(): 2ead, specifying different images to use when the widget is in a particular state or a combination of states. All images in the list should have the same size. compound Specifies how to display the image relative to the text, in the case both text and images options are present. Valid values are: * text: display text only * image: display image only * top, bottom, left, right: display image above, below, left of, or right of the text, respectively. * none: the default. display the image if present, otherwise the text. width If greater than zero, specifies how much space, in character widths, to allocate for the text label, if less than zero, specifies a minimum width. If zero or unspecified, the natural width of the text label is used.  File: python.info, Node: Compatibility Options, Next: Widget States, Prev: Label Options, Up: Widget 5.25.2.7 Compatibility Options .............................. Option Description ---------------------------------------------------------------------------------- state May be set to “normal” or “disabled” to control the “disabled” state bit. This is a write-only option: setting it changes the widget state, but the *note Widget.state(): 2eaf. method does not affect this option.  File: python.info, Node: Widget States, Next: ttk Widget, Prev: Compatibility Options, Up: Widget 5.25.2.8 Widget States ...................... The widget state is a bitmap of independent state flags. Flag Description ----------------------------------------------------------------------------------- active The mouse cursor is over the widget and pressing a mouse button will cause some action to occur disabled Widget is disabled under program control focus Widget has keyboard focus pressed Widget is being pressed selected “On”, “true”, or “current” for things like Checkbuttons and radiobuttons background Windows and Mac have a notion of an “active” or foreground window. The `background' state is set for widgets in a background window, and cleared for those in the foreground window readonly Widget should not allow user modification alternate A widget-specific alternate display format invalid The widget’s value is invalid A state specification is a sequence of state names, optionally prefixed with an exclamation point indicating that the bit is off.  File: python.info, Node: ttk Widget, Prev: Widget States, Up: Widget 5.25.2.9 ttk.Widget ................... Besides the methods described below, the ‘ttk.Widget’ supports the methods ‘tkinter.Widget.cget()’ and ‘tkinter.Widget.configure()’. -- Class: tkinter.ttk.Widget -- Method: identify (x, y) Returns the name of the element at position `x' `y', or the empty string if the point does not lie within any element. `x' and `y' are pixel coordinates relative to the widget. -- Method: instate (statespec, callback=None, *args, **kw) Test the widget’s state. If a callback is not specified, returns ‘True’ if the widget state matches `statespec' and ‘False’ otherwise. If callback is specified then it is called with args if widget state matches `statespec'. -- Method: state (statespec=None) Modify or inquire widget state. If `statespec' is specified, sets the widget state according to it and return a new `statespec' indicating which flags were changed. If `statespec' is not specified, returns the currently-enabled state flags. `statespec' will usually be a list or a tuple.  File: python.info, Node: Combobox, Next: Spinbox, Prev: Widget, Up: tkinter ttk — Tk themed widgets 5.25.2.10 Combobox .................. The ‘ttk.Combobox’ widget combines a text field with a pop-down list of values. This widget is a subclass of ‘Entry’. Besides the methods inherited from *note Widget: 2ea6.: ‘Widget.cget()’, ‘Widget.configure()’, *note Widget.identify(): 2eb2, *note Widget.instate(): 2eb3. and *note Widget.state(): 2eaf, and the following inherited from ‘Entry’: ‘Entry.bbox()’, ‘Entry.delete()’, ‘Entry.icursor()’, ‘Entry.index()’, ‘Entry.insert()’, ‘Entry.selection()’, ‘Entry.xview()’, it has some other methods, described at ‘ttk.Combobox’. * Menu: * Options:: * Virtual events:: * ttk.Combobox: ttk Combobox.  File: python.info, Node: Options, Next: Virtual events, Up: Combobox 5.25.2.11 Options ................. This widget accepts the following specific options: Option Description ----------------------------------------------------------------------------------- exportselection Boolean value. If set, the widget selection is linked to the Window Manager selection (which can be returned by invoking Misc.selection_get, for example). justify Specifies how the text is aligned within the widget. One of “left”, “center”, or “right”. height Specifies the height of the pop-down listbox, in rows. postcommand A script (possibly registered with Misc.register) that is called immediately before displaying the values. It may specify which values to display. state One of “normal”, “readonly”, or “disabled”. In the “readonly” state, the value may not be edited directly, and the user can only selection of the values from the dropdown list. In the “normal” state, the text field is directly editable. In the “disabled” state, no interaction is possible. textvariable Specifies a name whose value is linked to the widget value. Whenever the value associated with that name changes, the widget value is updated, and vice versa. See ‘tkinter.StringVar’. values Specifies the list of values to display in the drop-down listbox. width Specifies an integer value indicating the desired width of the entry window, in average-size characters of the widget’s font.  File: python.info, Node: Virtual events, Next: ttk Combobox, Prev: Options, Up: Combobox 5.25.2.12 Virtual events ........................ The combobox widgets generates a `<<ComboboxSelected>>' virtual event when the user selects an element from the list of values.  File: python.info, Node: ttk Combobox, Prev: Virtual events, Up: Combobox 5.25.2.13 ttk.Combobox ...................... -- Class: tkinter.ttk.Combobox -- Method: current (newindex=None) If `newindex' is specified, sets the combobox value to the element position `newindex'. Otherwise, returns the index of the current value or -1 if the current value is not in the values list. -- Method: get () Returns the current value of the combobox. -- Method: set (value) Sets the value of the combobox to `value'.  File: python.info, Node: Spinbox, Next: Notebook, Prev: Combobox, Up: tkinter ttk — Tk themed widgets 5.25.2.14 Spinbox ................. The ‘ttk.Spinbox’ widget is a ‘ttk.Entry’ enhanced with increment and decrement arrows. It can be used for numbers or lists of string values. This widget is a subclass of ‘Entry’. Besides the methods inherited from *note Widget: 2ea6.: ‘Widget.cget()’, ‘Widget.configure()’, *note Widget.identify(): 2eb2, *note Widget.instate(): 2eb3. and *note Widget.state(): 2eaf, and the following inherited from ‘Entry’: ‘Entry.bbox()’, ‘Entry.delete()’, ‘Entry.icursor()’, ‘Entry.index()’, ‘Entry.insert()’, ‘Entry.xview()’, it has some other methods, described at ‘ttk.Spinbox’. * Menu: * Options: Options<2>. * Virtual events: Virtual events<2>. * ttk.Spinbox: ttk Spinbox.  File: python.info, Node: Options<2>, Next: Virtual events<2>, Up: Spinbox 5.25.2.15 Options ................. This widget accepts the following specific options: Option Description -------------------------------------------------------------------------------------- from Float value. If set, this is the minimum value to which the decrement button will decrement. Must be spelled as ‘from_’ when used as an argument, since ‘from’ is a Python keyword. to Float value. If set, this is the maximum value to which the increment button will increment. increment Float value. Specifies the amount which the increment/decrement buttons change the value. Defaults to 1.0. values Sequence of string or float values. If specified, the increment/decrement buttons will cycle through the items in this sequence rather than incrementing or decrementing numbers. wrap Boolean value. If ‘True’, increment and decrement buttons will cycle from the ‘to’ value to the ‘from’ value or the ‘from’ value to the ‘to’ value, respectively. format String value. This specifies the format of numbers set by the increment/decrement buttons. It must be in the form “%W.Pf”, where W is the padded width of the value, P is the precision, and ‘%’ and ‘f’ are literal. command Python callable. Will be called with no arguments whenever either of the increment or decrement buttons are pressed.  File: python.info, Node: Virtual events<2>, Next: ttk Spinbox, Prev: Options<2>, Up: Spinbox 5.25.2.16 Virtual events ........................ The spinbox widget generates an `<<Increment>>' virtual event when the user presses <Up>, and a `<<Decrement>>' virtual event when the user presses <Down>.  File: python.info, Node: ttk Spinbox, Prev: Virtual events<2>, Up: Spinbox 5.25.2.17 ttk.Spinbox ..................... -- Class: tkinter.ttk.Spinbox -- Method: get () Returns the current value of the spinbox. -- Method: set (value) Sets the value of the spinbox to `value'.  File: python.info, Node: Notebook, Next: Progressbar, Prev: Spinbox, Up: tkinter ttk — Tk themed widgets 5.25.2.18 Notebook .................. Ttk Notebook widget manages a collection of windows and displays a single one at a time. Each child window is associated with a tab, which the user may select to change the currently-displayed window. * Menu: * Options: Options<3>. * Tab Options:: * Tab Identifiers:: * Virtual Events:: * ttk.Notebook: ttk Notebook.  File: python.info, Node: Options<3>, Next: Tab Options, Up: Notebook 5.25.2.19 Options ................. This widget accepts the following specific options: Option Description ----------------------------------------------------------------------------------- height If present and greater than zero, specifies the desired height of the pane area (not including internal padding or tabs). Otherwise, the maximum height of all panes is used. padding Specifies the amount of extra space to add around the outside of the notebook. The padding is a list up to four length specifications left top right bottom. If fewer than four elements are specified, bottom defaults to top, right defaults to left, and top defaults to left. width If present and greater than zero, specified the desired width of the pane area (not including internal padding). Otherwise, the maximum width of all panes is used.  File: python.info, Node: Tab Options, Next: Tab Identifiers, Prev: Options<3>, Up: Notebook 5.25.2.20 Tab Options ..................... There are also specific options for tabs: Option Description ----------------------------------------------------------------------------------- state Either “normal”, “disabled” or “hidden”. If “disabled”, then the tab is not selectable. If “hidden”, then the tab is not shown. sticky Specifies how the child window is positioned within the pane area. Value is a string containing zero or more of the characters “n”, “s”, “e” or “w”. Each letter refers to a side (north, south, east or west) that the child window will stick to, as per the ‘grid()’ geometry manager. padding Specifies the amount of extra space to add between the notebook and this pane. Syntax is the same as for the option padding used by this widget. text Specifies a text to be displayed in the tab. image Specifies an image to display in the tab. See the option image described in *note Widget: 2ea6. compound Specifies how to display the image relative to the text, in the case both options text and image are present. See *note Label Options: 2eac. for legal values. underline Specifies the index (0-based) of a character to underline in the text string. The underlined character is used for mnemonic activation if *note Notebook.enable_traversal(): 2ec4. is called.  File: python.info, Node: Tab Identifiers, Next: Virtual Events, Prev: Tab Options, Up: Notebook 5.25.2.21 Tab Identifiers ......................... The tab_id present in several methods of ‘ttk.Notebook’ may take any of the following forms: * An integer between zero and the number of tabs * The name of a child window * A positional specification of the form “@x,y”, which identifies the tab * The literal string “current”, which identifies the currently-selected tab * The literal string “end”, which returns the number of tabs (only valid for *note Notebook.index(): 2ec6.)  File: python.info, Node: Virtual Events, Next: ttk Notebook, Prev: Tab Identifiers, Up: Notebook 5.25.2.22 Virtual Events ........................ This widget generates a `<<NotebookTabChanged>>' virtual event after a new tab is selected.  File: python.info, Node: ttk Notebook, Prev: Virtual Events, Up: Notebook 5.25.2.23 ttk.Notebook ...................... -- Class: tkinter.ttk.Notebook -- Method: add (child, **kw) Adds a new tab to the notebook. If window is currently managed by the notebook but hidden, it is restored to its previous position. See *note Tab Options: 2ec3. for the list of available options. -- Method: forget (tab_id) Removes the tab specified by `tab_id', unmaps and unmanages the associated window. -- Method: hide (tab_id) Hides the tab specified by `tab_id'. The tab will not be displayed, but the associated window remains managed by the notebook and its configuration remembered. Hidden tabs may be restored with the *note add(): 2ec9. command. -- Method: identify (x, y) Returns the name of the tab element at position `x', `y', or the empty string if none. -- Method: index (tab_id) Returns the numeric index of the tab specified by `tab_id', or the total number of tabs if `tab_id' is the string “end”. -- Method: insert (pos, child, **kw) Inserts a pane at the specified position. `pos' is either the string “end”, an integer index, or the name of a managed child. If `child' is already managed by the notebook, moves it to the specified position. See *note Tab Options: 2ec3. for the list of available options. -- Method: select (tab_id=None) Selects the specified `tab_id'. The associated child window will be displayed, and the previously-selected window (if different) is unmapped. If `tab_id' is omitted, returns the widget name of the currently selected pane. -- Method: tab (tab_id, option=None, **kw) Query or modify the options of the specific `tab_id'. If `kw' is not given, returns a dictionary of the tab option values. If `option' is specified, returns the value of that `option'. Otherwise, sets the options to the corresponding values. -- Method: tabs () Returns a list of windows managed by the notebook. -- Method: enable_traversal () Enable keyboard traversal for a toplevel window containing this notebook. This will extend the bindings for the toplevel window containing the notebook as follows: * ‘Control-Tab’: selects the tab following the currently selected one. * ‘Shift-Control-Tab’: selects the tab preceding the currently selected one. * ‘Alt-K’: where `K' is the mnemonic (underlined) character of any tab, will select that tab. Multiple notebooks in a single toplevel may be enabled for traversal, including nested notebooks. However, notebook traversal only works properly if all panes have the notebook they are in as master.  File: python.info, Node: Progressbar, Next: Separator, Prev: Notebook, Up: tkinter ttk — Tk themed widgets 5.25.2.24 Progressbar ..................... The ‘ttk.Progressbar’ widget shows the status of a long-running operation. It can operate in two modes: 1) the determinate mode which shows the amount completed relative to the total amount of work to be done and 2) the indeterminate mode which provides an animated display to let the user know that work is progressing. * Menu: * Options: Options<4>. * ttk.Progressbar: ttk Progressbar.  File: python.info, Node: Options<4>, Next: ttk Progressbar, Up: Progressbar 5.25.2.25 Options ................. This widget accepts the following specific options: Option Description ----------------------------------------------------------------------------------- orient One of “horizontal” or “vertical”. Specifies the orientation of the progress bar. length Specifies the length of the long axis of the progress bar (width if horizontal, height if vertical). mode One of “determinate” or “indeterminate”. maximum A number specifying the maximum value. Defaults to 100. value The current value of the progress bar. In “determinate” mode, this represents the amount of work completed. In “indeterminate” mode, it is interpreted as modulo `maximum'; that is, the progress bar completes one “cycle” when its value increases by `maximum'. variable A name which is linked to the option value. If specified, the value of the progress bar is automatically set to the value of this name whenever the latter is modified. phase Read-only option. The widget periodically increments the value of this option whenever its value is greater than 0 and, in determinate mode, less than maximum. This option may be used by the current theme to provide additional animation effects.  File: python.info, Node: ttk Progressbar, Prev: Options<4>, Up: Progressbar 5.25.2.26 ttk.Progressbar ......................... -- Class: tkinter.ttk.Progressbar -- Method: start (interval=None) Begin autoincrement mode: schedules a recurring timer event that calls *note Progressbar.step(): 2ed5. every `interval' milliseconds. If omitted, `interval' defaults to 50 milliseconds. -- Method: step (amount=None) Increments the progress bar’s value by `amount'. `amount' defaults to 1.0 if omitted. -- Method: stop () Stop autoincrement mode: cancels any recurring timer event initiated by *note Progressbar.start(): 2ed4. for this progress bar.  File: python.info, Node: Separator, Next: Sizegrip, Prev: Progressbar, Up: tkinter ttk — Tk themed widgets 5.25.2.27 Separator ................... The ‘ttk.Separator’ widget displays a horizontal or vertical separator bar. It has no other methods besides the ones inherited from ‘ttk.Widget’. * Menu: * Options: Options<5>.  File: python.info, Node: Options<5>, Up: Separator 5.25.2.28 Options ................. This widget accepts the following specific option: Option Description ---------------------------------------------------------------------------------- orient One of “horizontal” or “vertical”. Specifies the orientation of the separator.  File: python.info, Node: Sizegrip, Next: Treeview, Prev: Separator, Up: tkinter ttk — Tk themed widgets 5.25.2.29 Sizegrip .................. The ‘ttk.Sizegrip’ widget (also known as a grow box) allows the user to resize the containing toplevel window by pressing and dragging the grip. This widget has neither specific options nor specific methods, besides the ones inherited from ‘ttk.Widget’. * Menu: * Platform-specific notes:: * Bugs::  File: python.info, Node: Platform-specific notes, Next: Bugs, Up: Sizegrip 5.25.2.30 Platform-specific notes ................................. * On MacOS X, toplevel windows automatically include a built-in size grip by default. Adding a ‘Sizegrip’ is harmless, since the built-in grip will just mask the widget.  File: python.info, Node: Bugs, Prev: Platform-specific notes, Up: Sizegrip 5.25.2.31 Bugs .............. * If the containing toplevel’s position was specified relative to the right or bottom of the screen (e.g. ….), the ‘Sizegrip’ widget will not resize the window. * This widget supports only “southeast” resizing.  File: python.info, Node: Treeview, Next: Ttk Styling, Prev: Sizegrip, Up: tkinter ttk — Tk themed widgets 5.25.2.32 Treeview .................. The ‘ttk.Treeview’ widget displays a hierarchical collection of items. Each item has a textual label, an optional image, and an optional list of data values. The data values are displayed in successive columns after the tree label. The order in which data values are displayed may be controlled by setting the widget option ‘displaycolumns’. The tree widget can also display column headings. Columns may be accessed by number or symbolic names listed in the widget option columns. See *note Column Identifiers: 2edd. Each item is identified by a unique name. The widget will generate item IDs if they are not supplied by the caller. There is a distinguished root item, named ‘{}’. The root item itself is not displayed; its children appear at the top level of the hierarchy. Each item also has a list of tags, which can be used to associate event bindings with individual items and control the appearance of the item. The Treeview widget supports horizontal and vertical scrolling, according to the options described in *note Scrollable Widget Options: 2eab. and the methods *note Treeview.xview(): 2ede. and *note Treeview.yview(): 2edf. * Menu: * Options: Options<6>. * Item Options:: * Tag Options:: * Column Identifiers:: * Virtual Events: Virtual Events<2>. * ttk.Treeview: ttk Treeview.  File: python.info, Node: Options<6>, Next: Item Options, Up: Treeview 5.25.2.33 Options ................. This widget accepts the following specific options: Option Description ---------------------------------------------------------------------------------- columns A list of column identifiers, specifying the number of columns and their names. displaycolumns A list of column identifiers (either symbolic or integer indices) specifying which data columns are displayed and the order in which they appear, or the string “#all”. height Specifies the number of rows which should be visible. Note: the requested width is determined from the sum of the column widths. padding Specifies the internal padding for the widget. The padding is a list of up to four length specifications. selectmode Controls how the built-in class bindings manage the selection. One of “extended”, “browse” or “none”. If set to “extended” (the default), multiple items may be selected. If “browse”, only a single item will be selected at a time. If “none”, the selection will not be changed. Note that the application code and tag bindings can set the selection however they wish, regardless of the value of this option. show A list containing zero or more of the following values, specifying which elements of the tree to display. * tree: display tree labels in column #0. * headings: display the heading row. The default is “tree headings”, i.e., show all elements. `Note': Column #0 always refers to the tree column, even if show=”tree” is not specified.  File: python.info, Node: Item Options, Next: Tag Options, Prev: Options<6>, Up: Treeview 5.25.2.34 Item Options ...................... The following item options may be specified for items in the insert and item widget commands. Option Description --------------------------------------------------------------------------------- text The textual label to display for the item. image A Tk Image, displayed to the left of the label. values The list of values associated with the item. Each item should have the same number of values as the widget option columns. If there are fewer values than columns, the remaining values are assumed empty. If there are more values than columns, the extra values are ignored. open ‘True’/‘False’ value indicating whether the item’s children should be displayed or hidden. tags A list of tags associated with this item.  File: python.info, Node: Tag Options, Next: Column Identifiers, Prev: Item Options, Up: Treeview 5.25.2.35 Tag Options ..................... The following options may be specified on tags: Option Description --------------------------------------------------------------------------------- foreground Specifies the text foreground color. background Specifies the cell or item background color. font Specifies the font to use when drawing text. image Specifies the item image, in case the item’s image option is empty.  File: python.info, Node: Column Identifiers, Next: Virtual Events<2>, Prev: Tag Options, Up: Treeview 5.25.2.36 Column Identifiers ............................ Column identifiers take any of the following forms: * A symbolic name from the list of columns option. * An integer n, specifying the nth data column. * A string of the form #n, where n is an integer, specifying the nth display column. Notes: * Item’s option values may be displayed in a different order than the order in which they are stored. * Column #0 always refers to the tree column, even if show=”tree” is not specified. A data column number is an index into an item’s option values list; a display column number is the column number in the tree where the values are displayed. Tree labels are displayed in column #0. If option displaycolumns is not set, then data column n is displayed in column #n+1. Again, `column #0 always refers to the tree column'.  File: python.info, Node: Virtual Events<2>, Next: ttk Treeview, Prev: Column Identifiers, Up: Treeview 5.25.2.37 Virtual Events ........................ The Treeview widget generates the following virtual events. Event Description -------------------------------------------------------------------------------- <<TreeviewSelect>> Generated whenever the selection changes. <<TreeviewOpen>> Generated just before settings the focus item to open=True. <<TreeviewClose>> Generated just after setting the focus item to open=False. The *note Treeview.focus(): 2ee4. and *note Treeview.selection(): 2bc. methods can be used to determine the affected item or items.  File: python.info, Node: ttk Treeview, Prev: Virtual Events<2>, Up: Treeview 5.25.2.38 ttk.Treeview ...................... -- Class: tkinter.ttk.Treeview -- Method: bbox (item, column=None) Returns the bounding box (relative to the treeview widget’s window) of the specified `item' in the form (x, y, width, height). If `column' is specified, returns the bounding box of that cell. If the `item' is not visible (i.e., if it is a descendant of a closed item or is scrolled offscreen), returns an empty string. -- Method: get_children (item=None) Returns the list of children belonging to `item'. If `item' is not specified, returns root children. -- Method: set_children (item, *newchildren) Replaces `item'’s child with `newchildren'. Children present in `item' that are not present in `newchildren' are detached from the tree. No items in `newchildren' may be an ancestor of `item'. Note that not specifying `newchildren' results in detaching `item'’s children. -- Method: column (column, option=None, **kw) Query or modify the options for the specified `column'. If `kw' is not given, returns a dict of the column option values. If `option' is specified then the value for that `option' is returned. Otherwise, sets the options to the corresponding values. The valid options/values are: * id Returns the column name. This is a read-only option. * anchor: One of the standard Tk anchor values. Specifies how the text in this column should be aligned with respect to the cell. * minwidth: width The minimum width of the column in pixels. The treeview widget will not make the column any smaller than specified by this option when the widget is resized or the user drags a column. * stretch: ‘True’/‘False’ Specifies whether the column’s width should be adjusted when the widget is resized. * width: width The width of the column in pixels. To configure the tree column, call this with column = “#0” -- Method: delete (*items) Delete all specified `items' and all their descendants. The root item may not be deleted. -- Method: detach (*items) Unlinks all of the specified `items' from the tree. The items and all of their descendants are still present, and may be reinserted at another point in the tree, but will not be displayed. The root item may not be detached. -- Method: exists (item) Returns ‘True’ if the specified `item' is present in the tree. -- Method: focus (item=None) If `item' is specified, sets the focus item to `item'. Otherwise, returns the current focus item, or ‘’ if there is none. -- Method: heading (column, option=None, **kw) Query or modify the heading options for the specified `column'. If `kw' is not given, returns a dict of the heading option values. If `option' is specified then the value for that `option' is returned. Otherwise, sets the options to the corresponding values. The valid options/values are: * text: text The text to display in the column heading. * image: imageName Specifies an image to display to the right of the column heading. * anchor: anchor Specifies how the heading text should be aligned. One of the standard Tk anchor values. * command: callback A callback to be invoked when the heading label is pressed. To configure the tree column heading, call this with column = “#0”. -- Method: identify (component, x, y) Returns a description of the specified `component' under the point given by `x' and `y', or the empty string if no such `component' is present at that position. -- Method: identify_row (y) Returns the item ID of the item at position `y'. -- Method: identify_column (x) Returns the data column identifier of the cell at position `x'. The tree column has ID #0. -- Method: identify_region (x, y) Returns one of: region meaning ----------------------------------------------------------- heading Tree heading area. separator Space between two columns headings. tree The tree area. cell A data cell. Availability: Tk 8.6. -- Method: identify_element (x, y) Returns the element at position `x', `y'. Availability: Tk 8.6. -- Method: index (item) Returns the integer index of `item' within its parent’s list of children. -- Method: insert (parent, index, iid=None, **kw) Creates a new item and returns the item identifier of the newly created item. `parent' is the item ID of the parent item, or the empty string to create a new top-level item. `index' is an integer, or the value “end”, specifying where in the list of parent’s children to insert the new item. If `index' is less than or equal to zero, the new node is inserted at the beginning; if `index' is greater than or equal to the current number of children, it is inserted at the end. If `iid' is specified, it is used as the item identifier; `iid' must not already exist in the tree. Otherwise, a new unique identifier is generated. See *note Item Options: 2ee1. for the list of available points. -- Method: item (item, option=None, **kw) Query or modify the options for the specified `item'. If no options are given, a dict with options/values for the item is returned. If `option' is specified then the value for that option is returned. Otherwise, sets the options to the corresponding values as given by `kw'. -- Method: move (item, parent, index) Moves `item' to position `index' in `parent'’s list of children. It is illegal to move an item under one of its descendants. If `index' is less than or equal to zero, `item' is moved to the beginning; if greater than or equal to the number of children, it is moved to the end. If `item' was detached it is reattached. -- Method: next (item) Returns the identifier of `item'’s next sibling, or ‘’ if `item' is the last child of its parent. -- Method: parent (item) Returns the ID of the parent of `item', or ‘’ if `item' is at the top level of the hierarchy. -- Method: prev (item) Returns the identifier of `item'’s previous sibling, or ‘’ if `item' is the first child of its parent. -- Method: reattach (item, parent, index) An alias for *note Treeview.move(): 2ef6. -- Method: see (item) Ensure that `item' is visible. Sets all of `item'’s ancestors open option to ‘True’, and scrolls the widget if necessary so that `item' is within the visible portion of the tree. -- Method: selection () Returns a tuple of selected items. Changed in version 3.8: ‘selection()’ no longer takes arguments. For changing the selection state use the following selection methods. -- Method: selection_set (*items) `items' becomes the new selection. Changed in version 3.6: `items' can be passed as separate arguments, not just as a single tuple. -- Method: selection_add (*items) Add `items' to the selection. Changed in version 3.6: `items' can be passed as separate arguments, not just as a single tuple. -- Method: selection_remove (*items) Remove `items' from the selection. Changed in version 3.6: `items' can be passed as separate arguments, not just as a single tuple. -- Method: selection_toggle (*items) Toggle the selection state of each item in `items'. Changed in version 3.6: `items' can be passed as separate arguments, not just as a single tuple. -- Method: set (item, column=None, value=None) With one argument, returns a dictionary of column/value pairs for the specified `item'. With two arguments, returns the current value of the specified `column'. With three arguments, sets the value of given `column' in given `item' to the specified `value'. -- Method: tag_bind (tagname, sequence=None, callback=None) Bind a callback for the given event `sequence' to the tag `tagname'. When an event is delivered to an item, the callbacks for each of the item’s tags option are called. -- Method: tag_configure (tagname, option=None, **kw) Query or modify the options for the specified `tagname'. If `kw' is not given, returns a dict of the option settings for `tagname'. If `option' is specified, returns the value for that `option' for the specified `tagname'. Otherwise, sets the options to the corresponding values for the given `tagname'. -- Method: tag_has (tagname, item=None) If `item' is specified, returns 1 or 0 depending on whether the specified `item' has the given `tagname'. Otherwise, returns a list of all items that have the specified tag. Availability: Tk 8.6 -- Method: xview (*args) Query or modify horizontal position of the treeview. -- Method: yview (*args) Query or modify vertical position of the treeview.  File: python.info, Node: Ttk Styling, Prev: Treeview, Up: tkinter ttk — Tk themed widgets 5.25.2.39 Ttk Styling ..................... Each widget in ‘ttk’ is assigned a style, which specifies the set of elements making up the widget and how they are arranged, along with dynamic and default settings for element options. By default the style name is the same as the widget’s class name, but it may be overridden by the widget’s style option. If you don’t know the class name of a widget, use the method ‘Misc.winfo_class()’ (somewidget.winfo_class()). See also ........ Tcl’2004 conference presentation(1) This document explains how the theme engine works -- Class: tkinter.ttk.Style This class is used to manipulate the style database. -- Method: configure (style, query_opt=None, **kw) Query or set the default value of the specified option(s) in `style'. Each key in `kw' is an option and each value is a string identifying the value for that option. For example, to change every default button to be a flat button with some padding and a different background color: from tkinter import ttk import tkinter root = tkinter.Tk() ttk.Style().configure("TButton", padding=6, relief="flat", background="#ccc") btn = ttk.Button(text="Sample") btn.pack() root.mainloop() -- Method: map (style, query_opt=None, **kw) Query or sets dynamic values of the specified option(s) in `style'. Each key in `kw' is an option and each value should be a list or a tuple (usually) containing statespecs grouped in tuples, lists, or some other preference. A statespec is a compound of one or more states and then a value. An example may make it more understandable: import tkinter from tkinter import ttk root = tkinter.Tk() style = ttk.Style() style.map("C.TButton", foreground=[('pressed', 'red'), ('active', 'blue')], background=[('pressed', '!disabled', 'black'), ('active', 'white')] ) colored_btn = ttk.Button(text="Test", style="C.TButton").pack() root.mainloop() Note that the order of the (states, value) sequences for an option does matter, if the order is changed to ‘[('active', 'blue'), ('pressed', 'red')]’ in the foreground option, for example, the result would be a blue foreground when the widget were in active or pressed states. -- Method: lookup (style, option, state=None, default=None) Returns the value specified for `option' in `style'. If `state' is specified, it is expected to be a sequence of one or more states. If the `default' argument is set, it is used as a fallback value in case no specification for option is found. To check what font a Button uses by default: from tkinter import ttk print(ttk.Style().lookup("TButton", "font")) -- Method: layout (style, layoutspec=None) Define the widget layout for given `style'. If `layoutspec' is omitted, return the layout specification for given style. `layoutspec', if specified, is expected to be a list or some other sequence type (excluding strings), where each item should be a tuple and the first item is the layout name and the second item should have the format described in *note Layouts: 2f07. To understand the format, see the following example (it is not intended to do anything useful): from tkinter import ttk import tkinter root = tkinter.Tk() style = ttk.Style() style.layout("TMenubutton", [ ("Menubutton.background", None), ("Menubutton.button", {"children": [("Menubutton.focus", {"children": [("Menubutton.padding", {"children": [("Menubutton.label", {"side": "left", "expand": 1})] })] })] }), ]) mbtn = ttk.Menubutton(text='Text') mbtn.pack() root.mainloop() -- Method: element_create (elementname, etype, *args, **kw) Create a new element in the current theme, of the given `etype' which is expected to be either “image”, “from” or “vsapi”. The latter is only available in Tk 8.6a for Windows XP and Vista and is not described here. If “image” is used, `args' should contain the default image name followed by statespec/value pairs (this is the imagespec), and `kw' may have the following options: * border=padding padding is a list of up to four integers, specifying the left, top, right, and bottom borders, respectively. * height=height Specifies a minimum height for the element. If less than zero, the base image’s height is used as a default. * padding=padding Specifies the element’s interior padding. Defaults to border’s value if not specified. * sticky=spec Specifies how the image is placed within the final parcel. spec contains zero or more characters “n”, “s”, “w”, or “e”. * width=width Specifies a minimum width for the element. If less than zero, the base image’s width is used as a default. If “from” is used as the value of `etype', *note element_create(): 2f08. will clone an existing element. `args' is expected to contain a themename, from which the element will be cloned, and optionally an element to clone from. If this element to clone from is not specified, an empty element will be used. `kw' is discarded. -- Method: element_names () Returns the list of elements defined in the current theme. -- Method: element_options (elementname) Returns the list of `elementname'’s options. -- Method: theme_create (themename, parent=None, settings=None) Create a new theme. It is an error if `themename' already exists. If `parent' is specified, the new theme will inherit styles, elements and layouts from the parent theme. If `settings' are present they are expected to have the same syntax used for *note theme_settings(): 2f0c. -- Method: theme_settings (themename, settings) Temporarily sets the current theme to `themename', apply specified `settings' and then restore the previous theme. Each key in `settings' is a style and each value may contain the keys ‘configure’, ‘map’, ‘layout’ and ‘element create’ and they are expected to have the same format as specified by the methods *note Style.configure(): 2f04, *note Style.map(): 2ead, *note Style.layout(): 2f06. and *note Style.element_create(): 2f08. respectively. As an example, let’s change the Combobox for the default theme a bit: from tkinter import ttk import tkinter root = tkinter.Tk() style = ttk.Style() style.theme_settings("default", { "TCombobox": { "configure": {"padding": 5}, "map": { "background": [("active", "green2"), ("!disabled", "green4")], "fieldbackground": [("!disabled", "green3")], "foreground": [("focus", "OliveDrab1"), ("!disabled", "OliveDrab2")] } } }) combo = ttk.Combobox().pack() root.mainloop() -- Method: theme_names () Returns a list of all known themes. -- Method: theme_use (themename=None) If `themename' is not given, returns the theme in use. Otherwise, sets the current theme to `themename', refreshes all widgets and emits a <<ThemeChanged>> event. * Menu: * Layouts:: ---------- Footnotes ---------- (1) http://tktable.sourceforge.net/tile/tile-tcl2004.pdf  File: python.info, Node: Layouts, Up: Ttk Styling 5.25.2.40 Layouts ................. A layout can be just ‘None’, if it takes no options, or a dict of options specifying how to arrange the element. The layout mechanism uses a simplified version of the pack geometry manager: given an initial cavity, each element is allocated a parcel. Valid options/values are: * side: whichside Specifies which side of the cavity to place the element; one of top, right, bottom or left. If omitted, the element occupies the entire cavity. * sticky: nswe Specifies where the element is placed inside its allocated parcel. * unit: 0 or 1 If set to 1, causes the element and all of its descendants to be treated as a single element for the purposes of *note Widget.identify(): 2eb2. et al. It’s used for things like scrollbar thumbs with grips. * children: [sublayout… ] Specifies a list of elements to place inside the element. Each element is a tuple (or other sequence type) where the first item is the layout name, and the other is a *note Layout: 2f07.  File: python.info, Node: tkinter tix — Extension widgets for Tk, Next: tkinter scrolledtext — Scrolled Text Widget, Prev: tkinter ttk — Tk themed widgets, Up: Graphical User Interfaces with Tk 5.25.3 ‘tkinter.tix’ — Extension widgets for Tk ----------------------------------------------- `Source code:' Lib/tkinter/tix.py(1) Deprecated since version 3.6: This Tk extension is unmaintained and should not be used in new code. Use *note tkinter.ttk: 10f. instead. __________________________________________________________________ The *note tkinter.tix: 10e. (Tk Interface Extension) module provides an additional rich set of widgets. Although the standard Tk library has many useful widgets, they are far from complete. The *note tkinter.tix: 10e. library provides most of the commonly needed widgets that are missing from standard Tk: *note HList: 2f13, *note ComboBox: 2f14, *note Control: 2f15. (a.k.a. SpinBox) and an assortment of scrollable widgets. *note tkinter.tix: 10e. also includes many more widgets that are generally useful in a wide range of applications: *note NoteBook: 2f16, *note FileEntry: 2f17, *note PanedWindow: 2f18, etc; there are more than 40 of them. With all these new widgets, you can introduce new interaction techniques into applications, creating more useful and more intuitive user interfaces. You can design your application by choosing the most appropriate widgets to match the special needs of your application and users. See also ........ Tix Homepage(2) The home page for ‘Tix’. This includes links to additional documentation and downloads. Tix Man Pages(3) On-line version of the man pages and reference material. Tix Programming Guide(4) On-line version of the programmer’s reference material. Tix Development Applications(5) Tix applications for development of Tix and Tkinter programs. Tide applications work under Tk or Tkinter, and include ‘TixInspect’, an inspector to remotely modify and debug Tix/Tk/Tkinter applications. * Menu: * Using Tix:: * Tix Widgets:: * Tix Commands:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tkinter/tix.py (2) http://tix.sourceforge.net/ (3) http://tix.sourceforge.net/dist/current/man/ (4) http://tix.sourceforge.net/dist/current/docs/tix-book/tix.book.html (5) http://tix.sourceforge.net/Tixapps/src/Tide.html  File: python.info, Node: Using Tix, Next: Tix Widgets, Up: tkinter tix — Extension widgets for Tk 5.25.3.1 Using Tix .................. -- Class: tkinter.tix.Tk (screenName=None, baseName=None, className='Tix') Toplevel widget of Tix which represents mostly the main window of an application. It has an associated Tcl interpreter. Classes in the *note tkinter.tix: 10e. module subclasses the classes in the *note tkinter: 10c. The former imports the latter, so to use *note tkinter.tix: 10e. with Tkinter, all you need to do is to import one module. In general, you can just import *note tkinter.tix: 10e, and replace the toplevel call to *note tkinter.Tk: 2e84. with ‘tix.Tk’: from tkinter import tix from tkinter.constants import * root = tix.Tk() To use *note tkinter.tix: 10e, you must have the Tix widgets installed, usually alongside your installation of the Tk widgets. To test your installation, try the following: from tkinter import tix root = tix.Tk() root.tk.eval('package require Tix')  File: python.info, Node: Tix Widgets, Next: Tix Commands, Prev: Using Tix, Up: tkinter tix — Extension widgets for Tk 5.25.3.2 Tix Widgets .................... Tix(1) introduces over 40 widget classes to the *note tkinter: 10c. repertoire. * Menu: * Basic Widgets:: * File Selectors:: * Hierarchical ListBox:: * Tabular ListBox:: * Manager Widgets:: * Image Types:: * Miscellaneous Widgets:: * Form Geometry Manager:: ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/TixIntro.htm  File: python.info, Node: Basic Widgets, Next: File Selectors, Up: Tix Widgets 5.25.3.3 Basic Widgets ...................... -- Class: tkinter.tix.Balloon A Balloon(1) that pops up over a widget to provide help. When the user moves the cursor inside a widget to which a Balloon widget has been bound, a small pop-up window with a descriptive message will be shown on the screen. -- Class: tkinter.tix.ButtonBox The ButtonBox(2) widget creates a box of buttons, such as is commonly used for ‘Ok Cancel’. -- Class: tkinter.tix.ComboBox The ComboBox(3) widget is similar to the combo box control in MS Windows. The user can select a choice by either typing in the entry subwidget or selecting from the listbox subwidget. -- Class: tkinter.tix.Control The Control(4) widget is also known as the ‘SpinBox’ widget. The user can adjust the value by pressing the two arrow buttons or by entering the value directly into the entry. The new value will be checked against the user-defined upper and lower limits. -- Class: tkinter.tix.LabelEntry The LabelEntry(5) widget packages an entry widget and a label into one mega widget. It can be used to simplify the creation of “entry-form” type of interface. -- Class: tkinter.tix.LabelFrame The LabelFrame(6) widget packages a frame widget and a label into one mega widget. To create widgets inside a LabelFrame widget, one creates the new widgets relative to the ‘frame’ subwidget and manage them inside the ‘frame’ subwidget. -- Class: tkinter.tix.Meter The Meter(7) widget can be used to show the progress of a background job which may take a long time to execute. -- Class: tkinter.tix.OptionMenu The OptionMenu(8) creates a menu button of options. -- Class: tkinter.tix.PopupMenu The PopupMenu(9) widget can be used as a replacement of the ‘tk_popup’ command. The advantage of the ‘Tix’ *note PopupMenu: 2f23. widget is it requires less application code to manipulate. -- Class: tkinter.tix.Select The Select(10) widget is a container of button subwidgets. It can be used to provide radio-box or check-box style of selection options for the user. -- Class: tkinter.tix.StdButtonBox The StdButtonBox(11) widget is a group of standard buttons for Motif-like dialog boxes. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixBalloon.htm (2) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixButtonBox.htm (3) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixComboBox.htm (4) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixControl.htm (5) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixLabelEntry.htm (6) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixLabelFrame.htm (7) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixMeter.htm (8) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixOptionMenu.htm (9) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixPopupMenu.htm (10) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixSelect.htm (11) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixStdButtonBox.htm  File: python.info, Node: File Selectors, Next: Hierarchical ListBox, Prev: Basic Widgets, Up: Tix Widgets 5.25.3.4 File Selectors ....................... -- Class: tkinter.tix.DirList The DirList(1) widget displays a list view of a directory, its previous directories and its sub-directories. The user can choose one of the directories displayed in the list or change to another directory. -- Class: tkinter.tix.DirTree The DirTree(2) widget displays a tree view of a directory, its previous directories and its sub-directories. The user can choose one of the directories displayed in the list or change to another directory. -- Class: tkinter.tix.DirSelectDialog The DirSelectDialog(3) widget presents the directories in the file system in a dialog window. The user can use this dialog window to navigate through the file system to select the desired directory. -- Class: tkinter.tix.DirSelectBox The *note DirSelectBox: 2f2a. is similar to the standard Motif(TM) directory-selection box. It is generally used for the user to choose a directory. DirSelectBox stores the directories mostly recently selected into a ComboBox widget so that they can be quickly selected again. -- Class: tkinter.tix.ExFileSelectBox The ExFileSelectBox(4) widget is usually embedded in a tixExFileSelectDialog widget. It provides a convenient method for the user to select files. The style of the *note ExFileSelectBox: 2f2b. widget is very similar to the standard file dialog on MS Windows 3.1. -- Class: tkinter.tix.FileSelectBox The FileSelectBox(5) is similar to the standard Motif(TM) file-selection box. It is generally used for the user to choose a file. FileSelectBox stores the files mostly recently selected into a *note ComboBox: 2f14. widget so that they can be quickly selected again. -- Class: tkinter.tix.FileEntry The FileEntry(6) widget can be used to input a filename. The user can type in the filename manually. Alternatively, the user can press the button widget that sits next to the entry, which will bring up a file selection dialog. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirList.htm (2) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirTree.htm (3) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirSelectDialog.htm (4) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixExFileSelectBox.htm (5) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixFileSelectBox.htm (6) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixFileEntry.htm  File: python.info, Node: Hierarchical ListBox, Next: Tabular ListBox, Prev: File Selectors, Up: Tix Widgets 5.25.3.5 Hierarchical ListBox ............................. -- Class: tkinter.tix.HList The HList(1) widget can be used to display any data that have a hierarchical structure, for example, file system directory trees. The list entries are indented and connected by branch lines according to their places in the hierarchy. -- Class: tkinter.tix.CheckList The CheckList(2) widget displays a list of items to be selected by the user. CheckList acts similarly to the Tk checkbutton or radiobutton widgets, except it is capable of handling many more items than checkbuttons or radiobuttons. -- Class: tkinter.tix.Tree The Tree(3) widget can be used to display hierarchical data in a tree form. The user can adjust the view of the tree by opening or closing parts of the tree. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixHList.htm (2) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixCheckList.htm (3) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixTree.htm  File: python.info, Node: Tabular ListBox, Next: Manager Widgets, Prev: Hierarchical ListBox, Up: Tix Widgets 5.25.3.6 Tabular ListBox ........................ -- Class: tkinter.tix.TList The TList(1) widget can be used to display data in a tabular format. The list entries of a *note TList: 2f31. widget are similar to the entries in the Tk listbox widget. The main differences are (1) the *note TList: 2f31. widget can display the list entries in a two dimensional format and (2) you can use graphical images as well as multiple colors and fonts for the list entries. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixTList.htm  File: python.info, Node: Manager Widgets, Next: Image Types, Prev: Tabular ListBox, Up: Tix Widgets 5.25.3.7 Manager Widgets ........................ -- Class: tkinter.tix.PanedWindow The PanedWindow(1) widget allows the user to interactively manipulate the sizes of several panes. The panes can be arranged either vertically or horizontally. The user changes the sizes of the panes by dragging the resize handle between two panes. -- Class: tkinter.tix.ListNoteBook The ListNoteBook(2) widget is very similar to the ‘TixNoteBook’ widget: it can be used to display many windows in a limited space using a notebook metaphor. The notebook is divided into a stack of pages (windows). At one time only one of these pages can be shown. The user can navigate through these pages by choosing the name of the desired page in the ‘hlist’ subwidget. -- Class: tkinter.tix.NoteBook The NoteBook(3) widget can be used to display many windows in a limited space using a notebook metaphor. The notebook is divided into a stack of pages. At one time only one of these pages can be shown. The user can navigate through these pages by choosing the visual “tabs” at the top of the NoteBook widget. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixPanedWindow.htm (2) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixListNoteBook.htm (3) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixNoteBook.htm  File: python.info, Node: Image Types, Next: Miscellaneous Widgets, Prev: Manager Widgets, Up: Tix Widgets 5.25.3.8 Image Types .................... The *note tkinter.tix: 10e. module adds: * pixmap(1) capabilities to all *note tkinter.tix: 10e. and *note tkinter: 10c. widgets to create color images from XPM files. * Compound(2) image types can be used to create images that consists of multiple horizontal lines; each line is composed of a series of items (texts, bitmaps, images or spaces) arranged from left to right. For example, a compound image can be used to display a bitmap and a text string simultaneously in a Tk ‘Button’ widget. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/pixmap.htm (2) http://tix.sourceforge.net/dist/current/man/html/TixCmd/compound.htm  File: python.info, Node: Miscellaneous Widgets, Next: Form Geometry Manager, Prev: Image Types, Up: Tix Widgets 5.25.3.9 Miscellaneous Widgets .............................. -- Class: tkinter.tix.InputOnly The InputOnly(1) widgets are to accept inputs from the user, which can be done with the ‘bind’ command (Unix only). ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixInputOnly.htm  File: python.info, Node: Form Geometry Manager, Prev: Miscellaneous Widgets, Up: Tix Widgets 5.25.3.10 Form Geometry Manager ............................... In addition, *note tkinter.tix: 10e. augments *note tkinter: 10c. by providing: -- Class: tkinter.tix.Form The Form(1) geometry manager based on attachment rules for all Tk widgets. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixForm.htm  File: python.info, Node: Tix Commands, Prev: Tix Widgets, Up: tkinter tix — Extension widgets for Tk 5.25.3.11 Tix Commands ...................... -- Class: tkinter.tix.tixCommand The tix commands(1) provide access to miscellaneous elements of ‘Tix’’s internal state and the ‘Tix’ application context. Most of the information manipulated by these methods pertains to the application as a whole, or to a screen or display, rather than to a particular window. To view the current settings, the common usage is: from tkinter import tix root = tix.Tk() print(root.tix_configure()) -- Method: tixCommand.tix_configure (cnf=None, **kw) Query or modify the configuration options of the Tix application context. If no option is specified, returns a dictionary all of the available options. If option is specified with no value, then the method returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified). If one or more option-value pairs are specified, then the method modifies the given option(s) to have the given value(s); in this case the method returns an empty string. Option may be any of the configuration options. -- Method: tixCommand.tix_cget (option) Returns the current value of the configuration option given by `option'. Option may be any of the configuration options. -- Method: tixCommand.tix_getbitmap (name) Locates a bitmap file of the name ‘name.xpm’ or ‘name’ in one of the bitmap directories (see the *note tix_addbitmapdir(): 2f3e. method). By using *note tix_getbitmap(): 2f3d, you can avoid hard coding the pathnames of the bitmap files in your application. When successful, it returns the complete pathname of the bitmap file, prefixed with the character ‘@’. The returned value can be used to configure the ‘bitmap’ option of the Tk and Tix widgets. -- Method: tixCommand.tix_addbitmapdir (directory) Tix maintains a list of directories under which the *note tix_getimage(): 2f3f. and *note tix_getbitmap(): 2f3d. methods will search for image files. The standard bitmap directory is ‘$TIX_LIBRARY/bitmaps’. The *note tix_addbitmapdir(): 2f3e. method adds `directory' into this list. By using this method, the image files of an applications can also be located using the *note tix_getimage(): 2f3f. or *note tix_getbitmap(): 2f3d. method. -- Method: tixCommand.tix_filedialog ([dlgclass]) Returns the file selection dialog that may be shared among different calls from this application. This method will create a file selection dialog widget when it is called the first time. This dialog will be returned by all subsequent calls to *note tix_filedialog(): 2f40. An optional dlgclass parameter can be passed as a string to specified what type of file selection dialog widget is desired. Possible options are ‘tix’, ‘FileSelectDialog’ or ‘tixExFileSelectDialog’. -- Method: tixCommand.tix_getimage (self, name) Locates an image file of the name ‘name.xpm’, ‘name.xbm’ or ‘name.ppm’ in one of the bitmap directories (see the *note tix_addbitmapdir(): 2f3e. method above). If more than one file with the same name (but different extensions) exist, then the image type is chosen according to the depth of the X display: xbm images are chosen on monochrome displays and color images are chosen on color displays. By using *note tix_getimage(): 2f3f, you can avoid hard coding the pathnames of the image files in your application. When successful, this method returns the name of the newly created image, which can be used to configure the ‘image’ option of the Tk and Tix widgets. -- Method: tixCommand.tix_option_get (name) Gets the options maintained by the Tix scheme mechanism. -- Method: tixCommand.tix_resetoptions (newScheme, newFontSet[, newScmPrio]) Resets the scheme and fontset of the Tix application to `newScheme' and `newFontSet', respectively. This affects only those widgets created after this call. Therefore, it is best to call the resetoptions method before the creation of any widgets in a Tix application. The optional parameter `newScmPrio' can be given to reset the priority level of the Tk options set by the Tix schemes. Because of the way Tk handles the X option database, after Tix has been has imported and inited, it is not possible to reset the color schemes and font sets using the ‘tix_config()’ method. Instead, the *note tix_resetoptions(): 2f42. method must be used. ---------- Footnotes ---------- (1) http://tix.sourceforge.net/dist/current/man/html/TixCmd/tix.htm  File: python.info, Node: tkinter scrolledtext — Scrolled Text Widget, Next: IDLE<3>, Prev: tkinter tix — Extension widgets for Tk, Up: Graphical User Interfaces with Tk 5.25.4 ‘tkinter.scrolledtext’ — Scrolled Text Widget ---------------------------------------------------- `Source code:' Lib/tkinter/scrolledtext.py(1) __________________________________________________________________ The *note tkinter.scrolledtext: 10d. module provides a class of the same name which implements a basic text widget which has a vertical scroll bar configured to do the “right thing.” Using the ‘ScrolledText’ class is a lot easier than setting up a text widget and scroll bar directly. The constructor is the same as that of the ‘tkinter.Text’ class. The text widget and scrollbar are packed together in a ‘Frame’, and the methods of the ‘Grid’ and ‘Pack’ geometry managers are acquired from the ‘Frame’ object. This allows the ‘ScrolledText’ widget to be used directly to achieve most normal geometry management behavior. Should more specific control be necessary, the following attributes are available: -- Attribute: ScrolledText.frame The frame which surrounds the text and scroll bar widgets. -- Attribute: ScrolledText.vbar The scroll bar widget. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tkinter/scrolledtext.py  File: python.info, Node: IDLE<3>, Next: Other Graphical User Interface Packages, Prev: tkinter scrolledtext — Scrolled Text Widget, Up: Graphical User Interfaces with Tk 5.25.5 IDLE ----------- `Source code:' Lib/idlelib/(1) __________________________________________________________________ IDLE is Python’s Integrated Development and Learning Environment. IDLE has the following features: * coded in 100% pure Python, using the *note tkinter: 10c. GUI toolkit * cross-platform: works mostly the same on Windows, Unix, and macOS * Python shell window (interactive interpreter) with colorizing of code input, output, and error messages * multi-window text editor with multiple undo, Python colorizing, smart indent, call tips, auto completion, and other features * search within any window, replace within editor windows, and search through multiple files (grep) * debugger with persistent breakpoints, stepping, and viewing of global and local namespaces * configuration, browsers, and other dialogs * Menu: * Menus:: * Editing and navigation:: * Startup and code execution:: * Help and preferences:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/idlelib/  File: python.info, Node: Menus, Next: Editing and navigation, Up: IDLE<3> 5.25.5.1 Menus .............. IDLE has two main window types, the Shell window and the Editor window. It is possible to have multiple editor windows simultaneously. On Windows and Linux, each has its own top menu. Each menu documented below indicates which window type it is associated with. Output windows, such as used for Edit => Find in Files, are a subtype of editor window. They currently have the same top menu but a different default title and context menu. On macOS, there is one application menu. It dynamically changes according to the window currently selected. It has an IDLE menu, and some entries described below are moved around to conform to Apple guidelines. * Menu: * File menu (Shell and Editor): File menu Shell and Editor. * Edit menu (Shell and Editor): Edit menu Shell and Editor. * Format menu (Editor window only): Format menu Editor window only. * Run menu (Editor window only): Run menu Editor window only. * Shell menu (Shell window only): Shell menu Shell window only. * Debug menu (Shell window only): Debug menu Shell window only. * Options menu (Shell and Editor): Options menu Shell and Editor. * Window menu (Shell and Editor): Window menu Shell and Editor. * Help menu (Shell and Editor): Help menu Shell and Editor. * Context Menus::  File: python.info, Node: File menu Shell and Editor, Next: Edit menu Shell and Editor, Up: Menus 5.25.5.2 File menu (Shell and Editor) ..................................... New File Create a new file editing window. Open… Open an existing file with an Open dialog. Recent Files Open a list of recent files. Click one to open it. Open Module… Open an existing module (searches sys.path). Class Browser Show functions, classes, and methods in the current Editor file in a tree structure. In the shell, open a module first. Path Browser Show sys.path directories, modules, functions, classes and methods in a tree structure. Save Save the current window to the associated file, if there is one. Windows that have been changed since being opened or last saved have a * before and after the window title. If there is no associated file, do Save As instead. Save As… Save the current window with a Save As dialog. The file saved becomes the new associated file for the window. Save Copy As… Save the current window to different file without changing the associated file. Print Window Print the current window to the default printer. Close Close the current window (ask to save if unsaved). Exit Close all windows and quit IDLE (ask to save unsaved windows).  File: python.info, Node: Edit menu Shell and Editor, Next: Format menu Editor window only, Prev: File menu Shell and Editor, Up: Menus 5.25.5.3 Edit menu (Shell and Editor) ..................................... Undo Undo the last change to the current window. A maximum of 1000 changes may be undone. Redo Redo the last undone change to the current window. Cut Copy selection into the system-wide clipboard; then delete the selection. Copy Copy selection into the system-wide clipboard. Paste Insert contents of the system-wide clipboard into the current window. The clipboard functions are also available in context menus. Select All Select the entire contents of the current window. Find… Open a search dialog with many options Find Again Repeat the last search, if there is one. Find Selection Search for the currently selected string, if there is one. Find in Files… Open a file search dialog. Put results in a new output window. Replace… Open a search-and-replace dialog. Go to Line Move the cursor to the beginning of the line requested and make that line visible. A request past the end of the file goes to the end. Clear any selection and update the line and column status. Show Completions Open a scrollable list allowing selection of existing names. See *note Completions: 2f4c. in the Editing and navigation section below. Expand Word Expand a prefix you have typed to match a full word in the same window; repeat to get a different expansion. Show call tip After an unclosed parenthesis for a function, open a small window with function parameter hints. See *note Calltips: 2f4d. in the Editing and navigation section below. Show surrounding parens Highlight the surrounding parenthesis.  File: python.info, Node: Format menu Editor window only, Next: Run menu Editor window only, Prev: Edit menu Shell and Editor, Up: Menus 5.25.5.4 Format menu (Editor window only) ......................................... Indent Region Shift selected lines right by the indent width (default 4 spaces). Dedent Region Shift selected lines left by the indent width (default 4 spaces). Comment Out Region Insert ## in front of selected lines. Uncomment Region Remove leading # or ## from selected lines. Tabify Region Turn `leading' stretches of spaces into tabs. (Note: We recommend using 4 space blocks to indent Python code.) Untabify Region Turn `all' tabs into the correct number of spaces. Toggle Tabs Open a dialog to switch between indenting with spaces and tabs. New Indent Width Open a dialog to change indent width. The accepted default by the Python community is 4 spaces. Format Paragraph Reformat the current blank-line-delimited paragraph in comment block or multiline string or selected line in a string. All lines in the paragraph will be formatted to less than N columns, where N defaults to 72. Strip trailing whitespace Remove trailing space and other whitespace characters after the last non-whitespace character of a line by applying str.rstrip to each line, including lines within multiline strings. Except for Shell windows, remove extra newlines at the end of the file.  File: python.info, Node: Run menu Editor window only, Next: Shell menu Shell window only, Prev: Format menu Editor window only, Up: Menus 5.25.5.5 Run menu (Editor window only) ...................................... Run Module Do *note Check Module: 2f52. If no error, restart the shell to clean the environment, then execute the module. Output is displayed in the Shell window. Note that output requires use of ‘print’ or ‘write’. When execution is complete, the Shell retains focus and displays a prompt. At this point, one may interactively explore the result of execution. This is similar to executing a file with ‘python -i file’ at a command line. Run… Customized Same as *note Run Module: 2f51, but run the module with customized settings. `Command Line Arguments' extend *note sys.argv: bfb. as if passed on a command line. The module can be run in the Shell without restarting. Check Module Check the syntax of the module currently open in the Editor window. If the module has not been saved IDLE will either prompt the user to save or autosave, as selected in the General tab of the Idle Settings dialog. If there is a syntax error, the approximate location is indicated in the Editor window. Python Shell Open or wake up the Python Shell window.  File: python.info, Node: Shell menu Shell window only, Next: Debug menu Shell window only, Prev: Run menu Editor window only, Up: Menus 5.25.5.6 Shell menu (Shell window only) ....................................... View Last Restart Scroll the shell window to the last Shell restart. Restart Shell Restart the shell to clean the environment and reset display and exception handling. Previous History Cycle through earlier commands in history which match the current entry. Next History Cycle through later commands in history which match the current entry. Interrupt Execution Stop a running program.  File: python.info, Node: Debug menu Shell window only, Next: Options menu Shell and Editor, Prev: Shell menu Shell window only, Up: Menus 5.25.5.7 Debug menu (Shell window only) ....................................... Go to File/Line Look on the current line. with the cursor, and the line above for a filename and line number. If found, open the file if not already open, and show the line. Use this to view source lines referenced in an exception traceback and lines found by Find in Files. Also available in the context menu of the Shell window and Output windows. Debugger (toggle) When activated, code entered in the Shell or run from an Editor will run under the debugger. In the Editor, breakpoints can be set with the context menu. This feature is still incomplete and somewhat experimental. Stack Viewer Show the stack traceback of the last exception in a tree widget, with access to locals and globals. Auto-open Stack Viewer Toggle automatically opening the stack viewer on an unhandled exception.  File: python.info, Node: Options menu Shell and Editor, Next: Window menu Shell and Editor, Prev: Debug menu Shell window only, Up: Menus 5.25.5.8 Options menu (Shell and Editor) ........................................ Configure IDLE Open a configuration dialog and change preferences for the following: fonts, indentation, keybindings, text color themes, startup windows and size, additional help sources, and extensions. On macOS, open the configuration dialog by selecting Preferences in the application menu. For more details, see *note Setting preferences: 2f58. under Help and preferences. Most configuration options apply to all windows or all future windows. The option items below only apply to the active window. Show/Hide Code Context (Editor Window only) Open a pane at the top of the edit window which shows the block context of the code which has scrolled above the top of the window. See *note Code Context: 2f59. in the Editing and Navigation section below. Show/Hide Line Numbers (Editor Window only) Open a column to the left of the edit window which shows the number of each line of text. The default is off, which may be changed in the preferences (see *note Setting preferences: 2f58.). Zoom/Restore Height Toggles the window between normal size and maximum height. The initial size defaults to 40 lines by 80 chars unless changed on the General tab of the Configure IDLE dialog. The maximum height for a screen is determined by momentarily maximizing a window the first time one is zoomed on the screen. Changing screen settings may invalidate the saved height. This toggle has no effect when a window is maximized.  File: python.info, Node: Window menu Shell and Editor, Next: Help menu Shell and Editor, Prev: Options menu Shell and Editor, Up: Menus 5.25.5.9 Window menu (Shell and Editor) ....................................... Lists the names of all open windows; select one to bring it to the foreground (deiconifying it if necessary).  File: python.info, Node: Help menu Shell and Editor, Next: Context Menus, Prev: Window menu Shell and Editor, Up: Menus 5.25.5.10 Help menu (Shell and Editor) ...................................... About IDLE Display version, copyright, license, credits, and more. IDLE Help Display this IDLE document, detailing the menu options, basic editing and navigation, and other tips. Python Docs Access local Python documentation, if installed, or start a web browser and open docs.python.org showing the latest Python documentation. Turtle Demo Run the turtledemo module with example Python code and turtle drawings. Additional help sources may be added here with the Configure IDLE dialog under the General tab. See the *note Help sources: 2f5c. subsection below for more on Help menu choices.  File: python.info, Node: Context Menus, Prev: Help menu Shell and Editor, Up: Menus 5.25.5.11 Context Menus ....................... Open a context menu by right-clicking in a window (Control-click on macOS). Context menus have the standard clipboard functions also on the Edit menu. Cut Copy selection into the system-wide clipboard; then delete the selection. Copy Copy selection into the system-wide clipboard. Paste Insert contents of the system-wide clipboard into the current window. Editor windows also have breakpoint functions. Lines with a breakpoint set are specially marked. Breakpoints only have an effect when running under the debugger. Breakpoints for a file are saved in the user’s ‘.idlerc’ directory. Set Breakpoint Set a breakpoint on the current line. Clear Breakpoint Clear the breakpoint on that line. Shell and Output windows also have the following. Go to file/line Same as in Debug menu. The Shell window also has an output squeezing facility explained in the `Python Shell window' subsection below. Squeeze If the cursor is over an output line, squeeze all the output between the code above and the prompt below down to a ‘Squeezed text’ label.  File: python.info, Node: Editing and navigation, Next: Startup and code execution, Prev: Menus, Up: IDLE<3> 5.25.5.12 Editing and navigation ................................ * Menu: * Editor windows:: * Key bindings:: * Automatic indentation:: * Completions:: * Calltips:: * Code Context:: * Python Shell window:: * Text colors::  File: python.info, Node: Editor windows, Next: Key bindings, Up: Editing and navigation 5.25.5.13 Editor windows ........................ IDLE may open editor windows when it starts, depending on settings and how you start IDLE. Thereafter, use the File menu. There can be only one open editor window for a given file. The title bar contains the name of the file, the full path, and the version of Python and IDLE running the window. The status bar contains the line number (‘Ln’) and column number (‘Col’). Line numbers start with 1; column numbers with 0. IDLE assumes that files with a known .py* extension contain Python code and that other files do not. Run Python code with the Run menu.  File: python.info, Node: Key bindings, Next: Automatic indentation, Prev: Editor windows, Up: Editing and navigation 5.25.5.14 Key bindings ...................... In this section, ‘C’ refers to the ‘Control’ key on Windows and Unix and the ‘Command’ key on macOS. * ‘Backspace’ deletes to the left; ‘Del’ deletes to the right * ‘C-Backspace’ delete word left; ‘C-Del’ delete word to the right * Arrow keys and ‘Page Up’/‘Page Down’ to move around * ‘C-LeftArrow’ and ‘C-RightArrow’ moves by words * ‘Home’/‘End’ go to begin/end of line * ‘C-Home’/‘C-End’ go to begin/end of file * Some useful Emacs bindings are inherited from Tcl/Tk: * ‘C-a’ beginning of line * ‘C-e’ end of line * ‘C-k’ kill line (but doesn’t put it in clipboard) * ‘C-l’ center window around the insertion point * ‘C-b’ go backward one character without deleting (usually you can also use the cursor key for this) * ‘C-f’ go forward one character without deleting (usually you can also use the cursor key for this) * ‘C-p’ go up one line (usually you can also use the cursor key for this) * ‘C-d’ delete next character Standard keybindings (like ‘C-c’ to copy and ‘C-v’ to paste) may work. Keybindings are selected in the Configure IDLE dialog.  File: python.info, Node: Automatic indentation, Next: Completions, Prev: Key bindings, Up: Editing and navigation 5.25.5.15 Automatic indentation ............................... After a block-opening statement, the next line is indented by 4 spaces (in the Python Shell window by one tab). After certain keywords (break, return etc.) the next line is dedented. In leading indentation, ‘Backspace’ deletes up to 4 spaces if they are there. ‘Tab’ inserts spaces (in the Python Shell window one tab), number depends on Indent width. Currently, tabs are restricted to four spaces due to Tcl/Tk limitations. See also the indent/dedent region commands on the *note Format menu: 2f4e.  File: python.info, Node: Completions, Next: Calltips, Prev: Automatic indentation, Up: Editing and navigation 5.25.5.16 Completions ..................... Completions are supplied, when requested and available, for module names, attributes of classes or functions, or filenames. Each request method displays a completion box with existing names. (See tab completions below for an exception.) For any box, change the name being completed and the item highlighted in the box by typing and deleting characters; by hitting ‘Up’, ‘Down’, ‘PageUp’, ‘PageDown’, ‘Home’, and ‘End’ keys; and by a single click within the box. Close the box with ‘Escape’, ‘Enter’, and double ‘Tab’ keys or clicks outside the box. A double click within the box selects and closes. One way to open a box is to type a key character and wait for a predefined interval. This defaults to 2 seconds; customize it in the settings dialog. (To prevent auto popups, set the delay to a large number of milliseconds, such as 100000000.) For imported module names or class or function attributes, type ‘.’. For filenames in the root directory, type *note os.sep: 1936. or *note os.altsep: 1937. immediately after an opening quote. (On Windows, one can specify a drive first.) Move into subdirectories by typing a directory name and a separator. Instead of waiting, or after a box is closed, open a completion box immediately with Show Completions on the Edit menu. The default hot key is ‘C-space’. If one types a prefix for the desired name before opening the box, the first match or near miss is made visible. The result is the same as if one enters a prefix after the box is displayed. Show Completions after a quote completes filenames in the current directory instead of a root directory. Hitting ‘Tab’ after a prefix usually has the same effect as Show Completions. (With no prefix, it indents.) However, if there is only one match to the prefix, that match is immediately added to the editor text without opening a box. Invoking ‘Show Completions’, or hitting ‘Tab’ after a prefix, outside of a string and without a preceding ‘.’ opens a box with keywords, builtin names, and available module-level names. When editing code in an editor (as oppose to Shell), increase the available module-level names by running your code and not restarting the Shell thereafter. This is especially useful after adding imports at the top of a file. This also increases possible attribute completions. Completion boxes intially exclude names beginning with ‘_’ or, for modules, not included in ‘__all__’. The hidden names can be accessed by typing ‘_’ after ‘.’, either before or after the box is opened.  File: python.info, Node: Calltips, Next: Code Context, Prev: Completions, Up: Editing and navigation 5.25.5.17 Calltips .................. A calltip is shown automatically when one types ‘(’ after the name of an `accessible' function. A function name expression may include dots and subscripts. A calltip remains until it is clicked, the cursor is moved out of the argument area, or ‘)’ is typed. Whenever the cursor is in the argument part of a definition, select Edit and “Show Call Tip” on the menu or enter its shortcut to display a calltip. The calltip consists of the function’s signature and docstring up to the latter’s first blank line or the fifth non-blank line. (Some builtin functions lack an accessible signature.) A ‘/’ or ‘*’ in the signature indicates that the preceding or following arguments are passed by position or name (keyword) only. Details are subject to change. In Shell, the accessible functions depends on what modules have been imported into the user process, including those imported by Idle itself, and which definitions have been run, all since the last restart. For example, restart the Shell and enter ‘itertools.count(’. A calltip appears because Idle imports itertools into the user process for its own use. (This could change.) Enter ‘turtle.write(’ and nothing appears. Idle does not itself import turtle. The menu entry and shortcut also do nothing. Enter ‘import turtle’. Thereafter, ‘turtle.write(’ will display a calltip. In an editor, import statements have no effect until one runs the file. One might want to run a file after writing import statements, after adding function definitions, or after opening an existing file.  File: python.info, Node: Code Context, Next: Python Shell window, Prev: Calltips, Up: Editing and navigation 5.25.5.18 Code Context ...................... Within an editor window containing Python code, code context can be toggled in order to show or hide a pane at the top of the window. When shown, this pane freezes the opening lines for block code, such as those beginning with ‘class’, ‘def’, or ‘if’ keywords, that would have otherwise scrolled out of view. The size of the pane will be expanded and contracted as needed to show the all current levels of context, up to the maximum number of lines defined in the Configure IDLE dialog (which defaults to 15). If there are no current context lines and the feature is toggled on, a single blank line will display. Clicking on a line in the context pane will move that line to the top of the editor. The text and background colors for the context pane can be configured under the Highlights tab in the Configure IDLE dialog.  File: python.info, Node: Python Shell window, Next: Text colors, Prev: Code Context, Up: Editing and navigation 5.25.5.19 Python Shell window ............................. With IDLE’s Shell, one enters, edits, and recalls complete statements. Most consoles and terminals only work with a single physical line at a time. When one pastes code into Shell, it is not compiled and possibly executed until one hits ‘Return’. One may edit pasted code first. If one pastes more that one statement into Shell, the result will be a *note SyntaxError: 458. when multiple statements are compiled as if they were one. The editing features described in previous subsections work when entering code interactively. IDLE’s Shell window also responds to the following keys. * ‘C-c’ interrupts executing command * ‘C-d’ sends end-of-file; closes window if typed at a ‘>>>’ prompt * ‘Alt-/’ (Expand word) is also useful to reduce typing Command history * ‘Alt-p’ retrieves previous command matching what you have typed. On macOS use ‘C-p’. * ‘Alt-n’ retrieves next. On macOS use ‘C-n’. * ‘Return’ while on any previous command retrieves that command  File: python.info, Node: Text colors, Prev: Python Shell window, Up: Editing and navigation 5.25.5.20 Text colors ..................... Idle defaults to black on white text, but colors text with special meanings. For the shell, these are shell output, shell error, user output, and user error. For Python code, at the shell prompt or in an editor, these are keywords, builtin class and function names, names following ‘class’ and ‘def’, strings, and comments. For any text window, these are the cursor (when present), found text (when possible), and selected text. Text coloring is done in the background, so uncolorized text is occasionally visible. To change the color scheme, use the Configure IDLE dialog Highlighting tab. The marking of debugger breakpoint lines in the editor and text in popups and dialogs is not user-configurable.  File: python.info, Node: Startup and code execution, Next: Help and preferences, Prev: Editing and navigation, Up: IDLE<3> 5.25.5.21 Startup and code execution .................................... Upon startup with the ‘-s’ option, IDLE will execute the file referenced by the environment variables ‘IDLESTARTUP’ or *note PYTHONSTARTUP: 8e5. IDLE first checks for ‘IDLESTARTUP’; if ‘IDLESTARTUP’ is present the file referenced is run. If ‘IDLESTARTUP’ is not present, IDLE checks for ‘PYTHONSTARTUP’. Files referenced by these environment variables are convenient places to store functions that are used frequently from the IDLE shell, or for executing import statements to import common modules. In addition, ‘Tk’ also loads a startup file if it is present. Note that the Tk file is loaded unconditionally. This additional file is ‘.Idle.py’ and is looked for in the user’s home directory. Statements in this file will be executed in the Tk namespace, so this file is not useful for importing functions to be used from IDLE’s Python shell. * Menu: * Command line usage:: * Startup failure:: * Running user code:: * User output in Shell:: * Developing tkinter applications:: * Running without a subprocess::  File: python.info, Node: Command line usage, Next: Startup failure, Up: Startup and code execution 5.25.5.22 Command line usage ............................ idle.py [-c command] [-d] [-e] [-h] [-i] [-r file] [-s] [-t title] [-] [arg] ... -c command run command in the shell window -d enable debugger and open shell window -e open editor window -h print help message with legal combinations and exit -i open shell window -r file run file in shell window -s run $IDLESTARTUP or $PYTHONSTARTUP first, in shell window -t title set title of shell window - run stdin in shell (- must be last option before args) If there are arguments: * If ‘-’, ‘-c’, or ‘r’ is used, all arguments are placed in ‘sys.argv[1:...]’ and ‘sys.argv[0]’ is set to ‘''’, ‘'-c'’, or ‘'-r'’. No editor window is opened, even if that is the default set in the Options dialog. * Otherwise, arguments are files opened for editing and ‘sys.argv’ reflects the arguments passed to IDLE itself.  File: python.info, Node: Startup failure, Next: Running user code, Prev: Command line usage, Up: Startup and code execution 5.25.5.23 Startup failure ......................... IDLE uses a socket to communicate between the IDLE GUI process and the user code execution process. A connection must be established whenever the Shell starts or restarts. (The latter is indicated by a divider line that says ‘RESTART’). If the user process fails to connect to the GUI process, it usually displays a ‘Tk’ error box with a ‘cannot connect’ message that directs the user here. It then exits. One specific connection failure on Unix systems results from misconfigured masquerading rules somewhere in a system’s network setup. When IDLE is started from a terminal, one will see a message starting with ‘** Invalid host:’. The valid value is ‘127.0.0.1 (idlelib.rpc.LOCALHOST)’. One can diagnose with ‘tcpconnect -irv 127.0.0.1 6543’ in one terminal window and ‘tcplisten <same args>’ in another. A common cause of failure is a user-written file with the same name as a standard library module, such as `random.py' and `tkinter.py'. When such a file is located in the same directory as a file that is about to be run, IDLE cannot import the stdlib file. The current fix is to rename the user file. Though less common than in the past, an antivirus or firewall program may stop the connection. If the program cannot be taught to allow the connection, then it must be turned off for IDLE to work. It is safe to allow this internal connection because no data is visible on external ports. A similar problem is a network mis-configuration that blocks connections. Python installation issues occasionally stop IDLE: multiple versions can clash, or a single installation might need admin access. If one undo the clash, or cannot or does not want to run as admin, it might be easiest to completely remove Python and start over. A zombie pythonw.exe process could be a problem. On Windows, use Task Manager to check for one and stop it if there is. Sometimes a restart initiated by a program crash or Keyboard Interrupt (control-C) may fail to connect. Dismissing the error box or using Restart Shell on the Shell menu may fix a temporary problem. When IDLE first starts, it attempts to read user configuration files in ‘~/.idlerc/’ (~ is one’s home directory). If there is a problem, an error message should be displayed. Leaving aside random disk glitches, this can be prevented by never editing the files by hand. Instead, use the configuration dialog, under Options. Once there is an error in a user configuration file, the best solution may be to delete it and start over with the settings dialog. If IDLE quits with no message, and it was not started from a console, try starting it from a console or terminal (‘python -m idlelib’) and see if this results in an error message. On Unix-based systems with tcl/tk older than ‘8.6.11’ (see ‘About IDLE’) certain characters of certain fonts can cause a tk failure with a message to the terminal. This can happen either if one starts IDLE to edit a file with such a character or later when entering such a character. If one cannot upgrade tcl/tk, then re-configure IDLE to use a font that works better.  File: python.info, Node: Running user code, Next: User output in Shell, Prev: Startup failure, Up: Startup and code execution 5.25.5.24 Running user code ........................... With rare exceptions, the result of executing Python code with IDLE is intended to be the same as executing the same code by the default method, directly with Python in a text-mode system console or terminal window. However, the different interface and operation occasionally affect visible results. For instance, ‘sys.modules’ starts with more entries, and ‘threading.activeCount()’ returns 2 instead of 1. By default, IDLE runs user code in a separate OS process rather than in the user interface process that runs the shell and editor. In the execution process, it replaces ‘sys.stdin’, ‘sys.stdout’, and ‘sys.stderr’ with objects that get input from and send output to the Shell window. The original values stored in ‘sys.__stdin__’, ‘sys.__stdout__’, and ‘sys.__stderr__’ are not touched, but may be ‘None’. Sending print output from one process to a text widget in another is slower than printing to a system terminal in the same process. This has the most effect when printing multiple arguments, as the string for each argument, each separator, the newline are sent separately. For development, this is usually not a problem, but if one wants to print faster in IDLE, format and join together everything one wants displayed together and then print a single string. Both format strings and *note str.join(): 12dd. can help combine fields and lines. IDLE’s standard stream replacements are not inherited by subprocesses created in the execution process, whether directly by user code or by modules such as multiprocessing. If such subprocess use ‘input’ from sys.stdin or ‘print’ or ‘write’ to sys.stdout or sys.stderr, IDLE should be started in a command line window. The secondary subprocess will then be attached to that window for input and output. If ‘sys’ is reset by user code, such as with ‘importlib.reload(sys)’, IDLE’s changes are lost and input from the keyboard and output to the screen will not work correctly. When Shell has the focus, it controls the keyboard and screen. This is normally transparent, but functions that directly access the keyboard and screen will not work. These include system-specific functions that determine whether a key has been pressed and if so, which. The IDLE code running in the execution process adds frames to the call stack that would not be there otherwise. IDLE wraps ‘sys.getrecursionlimit’ and ‘sys.setrecursionlimit’ to reduce the effect of the additional stack frames. When user code raises SystemExit either directly or by calling sys.exit, IDLE returns to a Shell prompt instead of exiting.  File: python.info, Node: User output in Shell, Next: Developing tkinter applications, Prev: Running user code, Up: Startup and code execution 5.25.5.25 User output in Shell .............................. When a program outputs text, the result is determined by the corresponding output device. When IDLE executes user code, ‘sys.stdout’ and ‘sys.stderr’ are connected to the display area of IDLE’s Shell. Some of its features are inherited from the underlying Tk Text widget. Others are programmed additions. Where it matters, Shell is designed for development rather than production runs. For instance, Shell never throws away output. A program that sends unlimited output to Shell will eventually fill memory, resulting in a memory error. In contrast, some system text windows only keep the last n lines of output. A Windows console, for instance, keeps a user-settable 1 to 9999 lines, with 300 the default. A Tk Text widget, and hence IDLE’s Shell, displays characters (codepoints) in the BMP (Basic Multilingual Plane) subset of Unicode. Which characters are displayed with a proper glyph and which with a replacement box depends on the operating system and installed fonts. Tab characters cause the following text to begin after the next tab stop. (They occur every 8 ‘characters’). Newline characters cause following text to appear on a new line. Other control characters are ignored or displayed as a space, box, or something else, depending on the operating system and font. (Moving the text cursor through such output with arrow keys may exhibit some surprising spacing behavior.) >>> s = 'a\tb\a<\x02><\r>\bc\nd' # Enter 22 chars. >>> len(s) 14 >>> s # Display repr(s) 'a\tb\x07<\x02><\r>\x08c\nd' >>> print(s, end='') # Display s as is. # Result varies by OS and font. Try it. The ‘repr’ function is used for interactive echo of expression values. It returns an altered version of the input string in which control codes, some BMP codepoints, and all non-BMP codepoints are replaced with escape codes. As demonstrated above, it allows one to identify the characters in a string, regardless of how they are displayed. Normal and error output are generally kept separate (on separate lines) from code input and each other. They each get different highlight colors. For SyntaxError tracebacks, the normal ‘^’ marking where the error was detected is replaced by coloring the text with an error highlight. When code run from a file causes other exceptions, one may right click on a traceback line to jump to the corresponding line in an IDLE editor. The file will be opened if necessary. Shell has a special facility for squeezing output lines down to a ‘Squeezed text’ label. This is done automatically for output over N lines (N = 50 by default). N can be changed in the PyShell section of the General page of the Settings dialog. Output with fewer lines can be squeezed by right clicking on the output. This can be useful lines long enough to slow down scrolling. Squeezed output is expanded in place by double-clicking the label. It can also be sent to the clipboard or a separate view window by right-clicking the label.  File: python.info, Node: Developing tkinter applications, Next: Running without a subprocess, Prev: User output in Shell, Up: Startup and code execution 5.25.5.26 Developing tkinter applications ......................................... IDLE is intentionally different from standard Python in order to facilitate development of tkinter programs. Enter ‘import tkinter as tk; root = tk.Tk()’ in standard Python and nothing appears. Enter the same in IDLE and a tk window appears. In standard Python, one must also enter ‘root.update()’ to see the window. IDLE does the equivalent in the background, about 20 times a second, which is about every 50 milliseconds. Next enter ‘b = tk.Button(root, text='button'); b.pack()’. Again, nothing visibly changes in standard Python until one enters ‘root.update()’. Most tkinter programs run ‘root.mainloop()’, which usually does not return until the tk app is destroyed. If the program is run with ‘python -i’ or from an IDLE editor, a ‘>>>’ shell prompt does not appear until ‘mainloop()’ returns, at which time there is nothing left to interact with. When running a tkinter program from an IDLE editor, one can comment out the mainloop call. One then gets a shell prompt immediately and can interact with the live application. One just has to remember to re-enable the mainloop call when running in standard Python.  File: python.info, Node: Running without a subprocess, Prev: Developing tkinter applications, Up: Startup and code execution 5.25.5.27 Running without a subprocess ...................................... By default, IDLE executes user code in a separate subprocess via a socket, which uses the internal loopback interface. This connection is not externally visible and no data is sent to or received from the Internet. If firewall software complains anyway, you can ignore it. If the attempt to make the socket connection fails, Idle will notify you. Such failures are sometimes transient, but if persistent, the problem may be either a firewall blocking the connection or misconfiguration of a particular system. Until the problem is fixed, one can run Idle with the -n command line switch. If IDLE is started with the -n command line switch it will run in a single process and will not create the subprocess which runs the RPC Python execution server. This can be useful if Python cannot create the subprocess or the RPC socket interface on your platform. However, in this mode user code is not isolated from IDLE itself. Also, the environment is not restarted when Run/Run Module (F5) is selected. If your code has been modified, you must reload() the affected modules and re-import any specific items (e.g. from foo import baz) if the changes are to take effect. For these reasons, it is preferable to run IDLE with the default subprocess if at all possible. Deprecated since version 3.4.  File: python.info, Node: Help and preferences, Prev: Startup and code execution, Up: IDLE<3> 5.25.5.28 Help and preferences .............................. * Menu: * Help sources:: * Setting preferences:: * IDLE on macOS:: * Extensions::  File: python.info, Node: Help sources, Next: Setting preferences, Up: Help and preferences 5.25.5.29 Help sources ...................... Help menu entry “IDLE Help” displays a formatted html version of the IDLE chapter of the Library Reference. The result, in a read-only tkinter text window, is close to what one sees in a web browser. Navigate through the text with a mousewheel, the scrollbar, or up and down arrow keys held down. Or click the TOC (Table of Contents) button and select a section header in the opened box. Help menu entry “Python Docs” opens the extensive sources of help, including tutorials, available at ‘docs.python.org/x.y’, where ‘x.y’ is the currently running Python version. If your system has an off-line copy of the docs (this may be an installation option), that will be opened instead. Selected URLs can be added or removed from the help menu at any time using the General tab of the Configure IDLE dialog.  File: python.info, Node: Setting preferences, Next: IDLE on macOS, Prev: Help sources, Up: Help and preferences 5.25.5.30 Setting preferences ............................. The font preferences, highlighting, keys, and general preferences can be changed via Configure IDLE on the Option menu. Non-default user settings are saved in a ‘.idlerc’ directory in the user’s home directory. Problems caused by bad user configuration files are solved by editing or deleting one or more of the files in ‘.idlerc’. On the Font tab, see the text sample for the effect of font face and size on multiple characters in multiple languages. Edit the sample to add other characters of personal interest. Use the sample to select monospaced fonts. If particular characters have problems in Shell or an editor, add them to the top of the sample and try changing first size and then font. On the Highlights and Keys tab, select a built-in or custom color theme and key set. To use a newer built-in color theme or key set with older IDLEs, save it as a new custom theme or key set and it well be accessible to older IDLEs.  File: python.info, Node: IDLE on macOS, Next: Extensions, Prev: Setting preferences, Up: Help and preferences 5.25.5.31 IDLE on macOS ....................... Under System Preferences: Dock, one can set “Prefer tabs when opening documents” to “Always”. This setting is not compatible with the tk/tkinter GUI framework used by IDLE, and it breaks a few IDLE features.  File: python.info, Node: Extensions, Prev: IDLE on macOS, Up: Help and preferences 5.25.5.32 Extensions .................... IDLE contains an extension facility. Preferences for extensions can be changed with the Extensions tab of the preferences dialog. See the beginning of config-extensions.def in the idlelib directory for further information. The only current default extension is zzdummy, an example also used for testing.  File: python.info, Node: Other Graphical User Interface Packages, Prev: IDLE<3>, Up: Graphical User Interfaces with Tk 5.25.6 Other Graphical User Interface Packages ---------------------------------------------- Major cross-platform (Windows, Mac OS X, Unix-like) GUI toolkits are available for Python: See also ........ PyGObject(1) PyGObject provides introspection bindings for C libraries using GObject(2). One of these libraries is the GTK+ 3(3) widget set. GTK+ comes with many more widgets than Tkinter provides. An online Python GTK+ 3 Tutorial(4) is available. PyGTK(5) PyGTK provides bindings for an older version of the library, GTK+ 2. It provides an object oriented interface that is slightly higher level than the C one. There are also bindings to GNOME(6). An online tutorial(7) is available. PyQt(8) PyQt is a ‘sip’-wrapped binding to the Qt toolkit. Qt is an extensive C++ GUI application development framework that is available for Unix, Windows and Mac OS X. ‘sip’ is a tool for generating bindings for C++ libraries as Python classes, and is specifically designed for Python. PySide2(9) Also known as the Qt for Python project, PySide2 is a newer binding to the Qt toolkit. It is provided by The Qt Company and aims to provide a complete port of PySide to Qt 5. Compared to PyQt, its licensing scheme is friendlier to non-open source applications. wxPython(10) wxPython is a cross-platform GUI toolkit for Python that is built around the popular wxWidgets(11) (formerly wxWindows) C++ toolkit. It provides a native look and feel for applications on Windows, Mac OS X, and Unix systems by using each platform’s native widgets where ever possible, (GTK+ on Unix-like systems). In addition to an extensive set of widgets, wxPython provides classes for online documentation and context sensitive help, printing, HTML viewing, low-level device context drawing, drag and drop, system clipboard access, an XML-based resource format and more, including an ever growing library of user-contributed modules. PyGTK, PyQt, PySide2, and wxPython, all have a modern look and feel and more widgets than Tkinter. In addition, there are many other GUI toolkits for Python, both cross-platform, and platform-specific. See the GUI Programming(12) page in the Python Wiki for a much more complete list, and also for links to documents where the different GUI toolkits are compared. ---------- Footnotes ---------- (1) https://wiki.gnome.org/Projects/PyGObject (2) https://developer.gnome.org/gobject/stable/ (3) https://www.gtk.org/ (4) https://python-gtk-3-tutorial.readthedocs.io/ (5) http://www.pygtk.org/ (6) https://www.gnome.org/ (7) http://www.pygtk.org/pygtk2tutorial/index.html (8) https://riverbankcomputing.com/software/pyqt/intro (9) https://doc.qt.io/qtforpython/ (10) https://www.wxpython.org (11) https://www.wxwidgets.org/ (12) https://wiki.python.org/moin/GuiProgramming  File: python.info, Node: Development Tools, Next: Debugging and Profiling, Prev: Graphical User Interfaces with Tk, Up: The Python Standard Library 5.26 Development Tools ====================== The modules described in this chapter help you write software. For example, the *note pydoc: d9. module takes a module and generates documentation based on the module’s contents. The *note doctest: 67. and *note unittest: 11b. modules contains frameworks for writing unit tests that automatically exercise code and verify that the expected output is produced. ‘2to3’ can translate Python 2.x source code into valid Python 3.x code. The list of modules described in this chapter is: * Menu: * typing — Support for type hints:: * pydoc — Documentation generator and online help system:: * doctest — Test interactive Python examples:: * unittest — Unit testing framework:: * unittest.mock — mock object library: unittest mock — mock object library. * unittest.mock — getting started: unittest mock — getting started. * 2to3 - Automated Python 2 to 3 code translation:: * test — Regression tests package for Python:: * test.support — Utilities for the Python test suite: test support — Utilities for the Python test suite. * test.support.script_helper — Utilities for the Python execution tests: test support script_helper — Utilities for the Python execution tests.  File: python.info, Node: typing — Support for type hints, Next: pydoc — Documentation generator and online help system, Up: Development Tools 5.26.1 ‘typing’ — Support for type hints ---------------------------------------- New in version 3.5. `Source code:' Lib/typing.py(1) Note: The Python runtime does not enforce function and variable type annotations. They can be used by third party tools such as type checkers, IDEs, linters, etc. __________________________________________________________________ This module provides runtime support for type hints as specified by PEP 484(2), PEP 526(3), PEP 544(4), PEP 586(5), PEP 589(6), and PEP 591(7). The most fundamental support consists of the types *note Any: 652, *note Union: 2f7b, *note Tuple: 2f7c, *note Callable: 2f7d, *note TypeVar: 2f7e, and *note Generic: 2f7f. For full specification please see PEP 484(8). For a simplified introduction to type hints see PEP 483(9). The function below takes and returns a string and is annotated as follows: def greeting(name: str) -> str: return 'Hello ' + name In the function ‘greeting’, the argument ‘name’ is expected to be of type *note str: 330. and the return type *note str: 330. Subtypes are accepted as arguments. * Menu: * Type aliases:: * NewType:: * Callable:: * Generics:: * User-defined generic types:: * The Any type:: * Nominal vs structural subtyping:: * Classes, functions, and decorators: Classes functions and decorators. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/typing.py (2) https://www.python.org/dev/peps/pep-0484 (3) https://www.python.org/dev/peps/pep-0526 (4) https://www.python.org/dev/peps/pep-0544 (5) https://www.python.org/dev/peps/pep-0586 (6) https://www.python.org/dev/peps/pep-0589 (7) https://www.python.org/dev/peps/pep-0591 (8) https://www.python.org/dev/peps/pep-0484 (9) https://www.python.org/dev/peps/pep-0483  File: python.info, Node: Type aliases, Next: NewType, Up: typing — Support for type hints 5.26.1.1 Type aliases ..................... A type alias is defined by assigning the type to the alias. In this example, ‘Vector’ and ‘List[float]’ will be treated as interchangeable synonyms: from typing import List Vector = List[float] def scale(scalar: float, vector: Vector) -> Vector: return [scalar * num for num in vector] # typechecks; a list of floats qualifies as a Vector. new_vector = scale(2.0, [1.0, -4.2, 5.4]) Type aliases are useful for simplifying complex type signatures. For example: from typing import Dict, Tuple, Sequence ConnectionOptions = Dict[str, str] Address = Tuple[str, int] Server = Tuple[Address, ConnectionOptions] def broadcast_message(message: str, servers: Sequence[Server]) -> None: ... # The static type checker will treat the previous type signature as # being exactly equivalent to this one. def broadcast_message( message: str, servers: Sequence[Tuple[Tuple[str, int], Dict[str, str]]]) -> None: ... Note that ‘None’ as a type hint is a special case and is replaced by ‘type(None)’.  File: python.info, Node: NewType, Next: Callable, Prev: Type aliases, Up: typing — Support for type hints 5.26.1.2 NewType ................ Use the *note NewType(): 5a5. helper function to create distinct types: from typing import NewType UserId = NewType('UserId', int) some_id = UserId(524313) The static type checker will treat the new type as if it were a subclass of the original type. This is useful in helping catch logical errors: def get_user_name(user_id: UserId) -> str: ... # typechecks user_a = get_user_name(UserId(42351)) # does not typecheck; an int is not a UserId user_b = get_user_name(-1) You may still perform all ‘int’ operations on a variable of type ‘UserId’, but the result will always be of type ‘int’. This lets you pass in a ‘UserId’ wherever an ‘int’ might be expected, but will prevent you from accidentally creating a ‘UserId’ in an invalid way: # 'output' is of type 'int', not 'UserId' output = UserId(23413) + UserId(54341) Note that these checks are enforced only by the static type checker. At runtime, the statement ‘Derived = NewType('Derived', Base)’ will make ‘Derived’ a function that immediately returns whatever parameter you pass it. That means the expression ‘Derived(some_value)’ does not create a new class or introduce any overhead beyond that of a regular function call. More precisely, the expression ‘some_value is Derived(some_value)’ is always true at runtime. This also means that it is not possible to create a subtype of ‘Derived’ since it is an identity function at runtime, not an actual type: from typing import NewType UserId = NewType('UserId', int) # Fails at runtime and does not typecheck class AdminUserId(UserId): pass However, it is possible to create a *note NewType(): 5a5. based on a ‘derived’ ‘NewType’: from typing import NewType UserId = NewType('UserId', int) ProUserId = NewType('ProUserId', UserId) and typechecking for ‘ProUserId’ will work as expected. See PEP 484(1) for more details. Note: Recall that the use of a type alias declares two types to be `equivalent' to one another. Doing ‘Alias = Original’ will make the static type checker treat ‘Alias’ as being `exactly equivalent' to ‘Original’ in all cases. This is useful when you want to simplify complex type signatures. In contrast, ‘NewType’ declares one type to be a `subtype' of another. Doing ‘Derived = NewType('Derived', Original)’ will make the static type checker treat ‘Derived’ as a `subclass' of ‘Original’, which means a value of type ‘Original’ cannot be used in places where a value of type ‘Derived’ is expected. This is useful when you want to prevent logic errors with minimal runtime cost. New in version 3.5.2. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484  File: python.info, Node: Callable, Next: Generics, Prev: NewType, Up: typing — Support for type hints 5.26.1.3 Callable ................. Frameworks expecting callback functions of specific signatures might be type hinted using ‘Callable[[Arg1Type, Arg2Type], ReturnType]’. For example: from typing import Callable def feeder(get_next_item: Callable[[], str]) -> None: # Body def async_query(on_success: Callable[[int], None], on_error: Callable[[int, Exception], None]) -> None: # Body It is possible to declare the return type of a callable without specifying the call signature by substituting a literal ellipsis for the list of arguments in the type hint: ‘Callable[..., ReturnType]’.  File: python.info, Node: Generics, Next: User-defined generic types, Prev: Callable, Up: typing — Support for type hints 5.26.1.4 Generics ................. Since type information about objects kept in containers cannot be statically inferred in a generic way, abstract base classes have been extended to support subscription to denote expected types for container elements. from typing import Mapping, Sequence def notify_by_email(employees: Sequence[Employee], overrides: Mapping[str, str]) -> None: ... Generics can be parameterized by using a new factory available in typing called *note TypeVar: 2f7e. from typing import Sequence, TypeVar T = TypeVar('T') # Declare type variable def first(l: Sequence[T]) -> T: # Generic function return l[0]  File: python.info, Node: User-defined generic types, Next: The Any type, Prev: Generics, Up: typing — Support for type hints 5.26.1.5 User-defined generic types ................................... A user-defined class can be defined as a generic class. from typing import TypeVar, Generic from logging import Logger T = TypeVar('T') class LoggedVar(Generic[T]): def __init__(self, value: T, name: str, logger: Logger) -> None: self.name = name self.logger = logger self.value = value def set(self, new: T) -> None: self.log('Set ' + repr(self.value)) self.value = new def get(self) -> T: self.log('Get ' + repr(self.value)) return self.value def log(self, message: str) -> None: self.logger.info('%s: %s', self.name, message) ‘Generic[T]’ as a base class defines that the class ‘LoggedVar’ takes a single type parameter ‘T’ . This also makes ‘T’ valid as a type within the class body. The *note Generic: 2f7f. base class defines *note __class_getitem__(): 327. so that ‘LoggedVar[t]’ is valid as a type: from typing import Iterable def zero_all_vars(vars: Iterable[LoggedVar[int]]) -> None: for var in vars: var.set(0) A generic type can have any number of type variables, and type variables may be constrained: from typing import TypeVar, Generic ... T = TypeVar('T') S = TypeVar('S', int, str) class StrangePair(Generic[T, S]): ... Each type variable argument to *note Generic: 2f7f. must be distinct. This is thus invalid: from typing import TypeVar, Generic ... T = TypeVar('T') class Pair(Generic[T, T]): # INVALID ... You can use multiple inheritance with *note Generic: 2f7f.: from typing import TypeVar, Generic, Sized T = TypeVar('T') class LinkedList(Sized, Generic[T]): ... When inheriting from generic classes, some type variables could be fixed: from typing import TypeVar, Mapping T = TypeVar('T') class MyDict(Mapping[str, T]): ... In this case ‘MyDict’ has a single parameter, ‘T’. Using a generic class without specifying type parameters assumes *note Any: 652. for each position. In the following example, ‘MyIterable’ is not generic but implicitly inherits from ‘Iterable[Any]’: from typing import Iterable class MyIterable(Iterable): # Same as Iterable[Any] User defined generic type aliases are also supported. Examples: from typing import TypeVar, Iterable, Tuple, Union S = TypeVar('S') Response = Union[Iterable[S], int] # Return type here is same as Union[Iterable[str], int] def response(query: str) -> Response[str]: ... T = TypeVar('T', int, float, complex) Vec = Iterable[Tuple[T, T]] def inproduct(v: Vec[T]) -> T: # Same as Iterable[Tuple[T, T]] return sum(x*y for x, y in v) Changed in version 3.7: *note Generic: 2f7f. no longer has a custom metaclass. A user-defined generic class can have ABCs as base classes without a metaclass conflict. Generic metaclasses are not supported. The outcome of parameterizing generics is cached, and most types in the typing module are hashable and comparable for equality.  File: python.info, Node: The Any type, Next: Nominal vs structural subtyping, Prev: User-defined generic types, Up: typing — Support for type hints 5.26.1.6 The ‘Any’ type ....................... A special kind of type is *note Any: 652. A static type checker will treat every type as being compatible with *note Any: 652. and *note Any: 652. as being compatible with every type. This means that it is possible to perform any operation or method call on a value of type *note Any: 652. and assign it to any variable: from typing import Any a = None # type: Any a = [] # OK a = 2 # OK s = '' # type: str s = a # OK def foo(item: Any) -> int: # Typechecks; 'item' could be any type, # and that type might have a 'bar' method item.bar() ... Notice that no typechecking is performed when assigning a value of type *note Any: 652. to a more precise type. For example, the static type checker did not report an error when assigning ‘a’ to ‘s’ even though ‘s’ was declared to be of type *note str: 330. and receives an *note int: 184. value at runtime! Furthermore, all functions without a return type or parameter types will implicitly default to using *note Any: 652.: def legacy_parser(text): ... return data # A static type checker will treat the above # as having the same signature as: def legacy_parser(text: Any) -> Any: ... return data This behavior allows *note Any: 652. to be used as an `escape hatch' when you need to mix dynamically and statically typed code. Contrast the behavior of *note Any: 652. with the behavior of *note object: 2b0. Similar to *note Any: 652, every type is a subtype of *note object: 2b0. However, unlike *note Any: 652, the reverse is not true: *note object: 2b0. is `not' a subtype of every other type. That means when the type of a value is *note object: 2b0, a type checker will reject almost all operations on it, and assigning it to a variable (or using it as a return value) of a more specialized type is a type error. For example: def hash_a(item: object) -> int: # Fails; an object does not have a 'magic' method. item.magic() ... def hash_b(item: Any) -> int: # Typechecks item.magic() ... # Typechecks, since ints and strs are subclasses of object hash_a(42) hash_a("foo") # Typechecks, since Any is compatible with all types hash_b(42) hash_b("foo") Use *note object: 2b0. to indicate that a value could be any type in a typesafe manner. Use *note Any: 652. to indicate that a value is dynamically typed.  File: python.info, Node: Nominal vs structural subtyping, Next: Classes functions and decorators, Prev: The Any type, Up: typing — Support for type hints 5.26.1.7 Nominal vs structural subtyping ........................................ Initially PEP 484(1) defined Python static type system as using `nominal subtyping'. This means that a class ‘A’ is allowed where a class ‘B’ is expected if and only if ‘A’ is a subclass of ‘B’. This requirement previously also applied to abstract base classes, such as *note Iterable: 1601. The problem with this approach is that a class had to be explicitly marked to support them, which is unpythonic and unlike what one would normally do in idiomatic dynamically typed Python code. For example, this conforms to PEP 484(2): from typing import Sized, Iterable, Iterator class Bucket(Sized, Iterable[int]): ... def __len__(self) -> int: ... def __iter__(self) -> Iterator[int]: ... PEP 544(3) allows to solve this problem by allowing users to write the above code without explicit base classes in the class definition, allowing ‘Bucket’ to be implicitly considered a subtype of both ‘Sized’ and ‘Iterable[int]’ by static type checkers. This is known as `structural subtyping' (or static duck-typing): from typing import Iterator, Iterable class Bucket: # Note: no base classes ... def __len__(self) -> int: ... def __iter__(self) -> Iterator[int]: ... def collect(items: Iterable[int]) -> int: ... result = collect(Bucket()) # Passes type check Moreover, by subclassing a special class *note Protocol: 23f, a user can define new custom protocols to fully enjoy structural subtyping (see examples below). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0484 (3) https://www.python.org/dev/peps/pep-0544  File: python.info, Node: Classes functions and decorators, Prev: Nominal vs structural subtyping, Up: typing — Support for type hints 5.26.1.8 Classes, functions, and decorators ........................................... The module defines the following classes, functions and decorators: -- Class: typing.TypeVar Type variable. Usage: T = TypeVar('T') # Can be anything A = TypeVar('A', str, bytes) # Must be str or bytes Type variables exist primarily for the benefit of static type checkers. They serve as the parameters for generic types as well as for generic function definitions. See class Generic for more information on generic types. Generic functions work as follows: def repeat(x: T, n: int) -> Sequence[T]: """Return a list containing n references to x.""" return [x]*n def longest(x: A, y: A) -> A: """Return the longest of two strings.""" return x if len(x) >= len(y) else y The latter example’s signature is essentially the overloading of ‘(str, str) -> str’ and ‘(bytes, bytes) -> bytes’. Also note that if the arguments are instances of some subclass of *note str: 330, the return type is still plain *note str: 330. At runtime, ‘isinstance(x, T)’ will raise *note TypeError: 192. In general, *note isinstance(): 44f. and *note issubclass(): 450. should not be used with types. Type variables may be marked covariant or contravariant by passing ‘covariant=True’ or ‘contravariant=True’. See PEP 484(1) for more details. By default type variables are invariant. Alternatively, a type variable may specify an upper bound using ‘bound=<type>’. This means that an actual type substituted (explicitly or implicitly) for the type variable must be a subclass of the boundary type, see PEP 484(2). -- Class: typing.Generic Abstract base class for generic types. A generic type is typically declared by inheriting from an instantiation of this class with one or more type variables. For example, a generic mapping type might be defined as: class Mapping(Generic[KT, VT]): def __getitem__(self, key: KT) -> VT: ... # Etc. This class can then be used as follows: X = TypeVar('X') Y = TypeVar('Y') def lookup_name(mapping: Mapping[X, Y], key: X, default: Y) -> Y: try: return mapping[key] except KeyError: return default -- Class: typing.Protocol (Generic) Base class for protocol classes. Protocol classes are defined like this: class Proto(Protocol): def meth(self) -> int: ... Such classes are primarily used with static type checkers that recognize structural subtyping (static duck-typing), for example: class C: def meth(self) -> int: return 0 def func(x: Proto) -> int: return x.meth() func(C()) # Passes static type check See PEP 544(3) for details. Protocol classes decorated with *note runtime_checkable(): 240. (described later) act as simple-minded runtime protocols that check only the presence of given attributes, ignoring their type signatures. Protocol classes can be generic, for example: class GenProto(Protocol[T]): def meth(self) -> T: ... New in version 3.8. -- Class: typing.Type (Generic[CT_co]) A variable annotated with ‘C’ may accept a value of type ‘C’. In contrast, a variable annotated with ‘Type[C]’ may accept values that are classes themselves – specifically, it will accept the `class object' of ‘C’. For example: a = 3 # Has type 'int' b = int # Has type 'Type[int]' c = type(a) # Also has type 'Type[int]' Note that ‘Type[C]’ is covariant: class User: ... class BasicUser(User): ... class ProUser(User): ... class TeamUser(User): ... # Accepts User, BasicUser, ProUser, TeamUser, ... def make_new_user(user_class: Type[User]) -> User: # ... return user_class() The fact that ‘Type[C]’ is covariant implies that all subclasses of ‘C’ should implement the same constructor signature and class method signatures as ‘C’. The type checker should flag violations of this, but should also allow constructor calls in subclasses that match the constructor calls in the indicated base class. How the type checker is required to handle this particular case may change in future revisions of PEP 484(4). The only legal parameters for *note Type: 2f8a. are classes, *note Any: 652, *note type variables: 2f84, and unions of any of these types. For example: def new_non_team_user(user_class: Type[Union[BasicUser, ProUser]]): ... ‘Type[Any]’ is equivalent to ‘Type’ which in turn is equivalent to ‘type’, which is the root of Python’s metaclass hierarchy. New in version 3.5.2. -- Class: typing.Iterable (Generic[T_co]) A generic version of *note collections.abc.Iterable: 1601. -- Class: typing.Iterator (Iterable[T_co]) A generic version of *note collections.abc.Iterator: 1602. -- Class: typing.Reversible (Iterable[T_co]) A generic version of *note collections.abc.Reversible: 52e. -- Class: typing.SupportsInt An ABC with one abstract method ‘__int__’. -- Class: typing.SupportsFloat An ABC with one abstract method ‘__float__’. -- Class: typing.SupportsComplex An ABC with one abstract method ‘__complex__’. -- Class: typing.SupportsBytes An ABC with one abstract method ‘__bytes__’. -- Class: typing.SupportsIndex An ABC with one abstract method ‘__index__’. New in version 3.8. -- Class: typing.SupportsAbs An ABC with one abstract method ‘__abs__’ that is covariant in its return type. -- Class: typing.SupportsRound An ABC with one abstract method ‘__round__’ that is covariant in its return type. -- Class: typing.Container (Generic[T_co]) A generic version of *note collections.abc.Container: 15ff. -- Class: typing.Hashable An alias to *note collections.abc.Hashable: 1600. -- Class: typing.Sized An alias to *note collections.abc.Sized: 1603. -- Class: typing.Collection (Sized, Iterable[T_co], Container[T_co]) A generic version of *note collections.abc.Collection: 52d. New in version 3.6.0. -- Class: typing.AbstractSet (Sized, Collection[T_co]) A generic version of *note collections.abc.Set: 1385. -- Class: typing.MutableSet (AbstractSet[T]) A generic version of *note collections.abc.MutableSet: 1606. -- Class: typing.Mapping (Sized, Collection[KT], Generic[VT_co]) A generic version of *note collections.abc.Mapping: 15f3. This type can be used as follows: def get_position_in_index(word_list: Mapping[str, int], word: str) -> int: return word_list[word] -- Class: typing.MutableMapping (Mapping[KT, VT]) A generic version of *note collections.abc.MutableMapping: 9ef. -- Class: typing.Sequence (Reversible[T_co], Collection[T_co]) A generic version of *note collections.abc.Sequence: 12db. -- Class: typing.MutableSequence (Sequence[T]) A generic version of *note collections.abc.MutableSequence: 6ac. -- Class: typing.ByteString (Sequence[int]) A generic version of *note collections.abc.ByteString: 1605. This type represents the types *note bytes: 331, *note bytearray: 332, and *note memoryview: 25c. of byte sequences. As a shorthand for this type, *note bytes: 331. can be used to annotate arguments of any of the types mentioned above. -- Class: typing.Deque (deque, MutableSequence[T]) A generic version of *note collections.deque: 531. New in version 3.5.4. New in version 3.6.1. -- Class: typing.List (list, MutableSequence[T]) Generic version of *note list: 262. Useful for annotating return types. To annotate arguments it is preferred to use an abstract collection type such as *note Sequence: 2f9a. or *note Iterable: 2f8b. This type may be used as follows: T = TypeVar('T', int, float) def vec2(x: T, y: T) -> List[T]: return [x, y] def keep_positives(vector: Sequence[T]) -> List[T]: return [item for item in vector if item > 0] -- Class: typing.Set (set, MutableSet[T]) A generic version of *note builtins.set: b6f. Useful for annotating return types. To annotate arguments it is preferred to use an abstract collection type such as *note AbstractSet: 2f96. -- Class: typing.FrozenSet (frozenset, AbstractSet[T_co]) A generic version of *note builtins.frozenset: bee. -- Class: typing.MappingView (Sized, Iterable[T_co]) A generic version of *note collections.abc.MappingView: 1607. -- Class: typing.KeysView (MappingView[KT_co], AbstractSet[KT_co]) A generic version of *note collections.abc.KeysView: 1609. -- Class: typing.ItemsView (MappingView, Generic[KT_co, VT_co]) A generic version of *note collections.abc.ItemsView: 1608. -- Class: typing.ValuesView (MappingView[VT_co]) A generic version of *note collections.abc.ValuesView: 160a. -- Class: typing.Awaitable (Generic[T_co]) A generic version of *note collections.abc.Awaitable: 6b6. New in version 3.5.2. -- Class: typing.Coroutine (Awaitable[V_co], Generic[T_co, T_contra, V_co]) A generic version of *note collections.abc.Coroutine: 6b7. The variance and order of type variables correspond to those of *note Generator: 2fa7, for example: from typing import List, Coroutine c = None # type: Coroutine[List[str], str, int] ... x = c.send('hi') # type: List[str] async def bar() -> None: x = await c # type: int New in version 3.5.3. -- Class: typing.AsyncIterable (Generic[T_co]) A generic version of *note collections.abc.AsyncIterable: 6b9. New in version 3.5.2. -- Class: typing.AsyncIterator (AsyncIterable[T_co]) A generic version of *note collections.abc.AsyncIterator: 6b8. New in version 3.5.2. -- Class: typing.ContextManager (Generic[T_co]) A generic version of *note contextlib.AbstractContextManager: 534. New in version 3.5.4. New in version 3.6.0. -- Class: typing.AsyncContextManager (Generic[T_co]) A generic version of *note contextlib.AbstractAsyncContextManager: 378. New in version 3.5.4. New in version 3.6.2. -- Class: typing.Dict (dict, MutableMapping[KT, VT]) A generic version of *note dict: 1b8. Useful for annotating return types. To annotate arguments it is preferred to use an abstract collection type such as *note Mapping: 2f98. This type can be used as follows: def count_words(text: str) -> Dict[str, int]: ... -- Class: typing.DefaultDict (collections.defaultdict, MutableMapping[KT, VT]) A generic version of *note collections.defaultdict: b3a. New in version 3.5.2. -- Class: typing.OrderedDict (collections.OrderedDict, MutableMapping[KT, VT]) A generic version of *note collections.OrderedDict: 1b9. New in version 3.7.2. -- Class: typing.Counter (collections.Counter, Dict[T, int]) A generic version of *note collections.Counter: 9da. New in version 3.5.4. New in version 3.6.1. -- Class: typing.ChainMap (collections.ChainMap, MutableMapping[KT, VT]) A generic version of *note collections.ChainMap: 4a9. New in version 3.5.4. New in version 3.6.1. -- Class: typing.Generator (Iterator[T_co], Generic[T_co, T_contra, V_co]) A generator can be annotated by the generic type ‘Generator[YieldType, SendType, ReturnType]’. For example: def echo_round() -> Generator[int, float, str]: sent = yield 0 while sent >= 0: sent = yield round(sent) return 'Done' Note that unlike many other generics in the typing module, the ‘SendType’ of *note Generator: 2fa7. behaves contravariantly, not covariantly or invariantly. If your generator will only yield values, set the ‘SendType’ and ‘ReturnType’ to ‘None’: def infinite_stream(start: int) -> Generator[int, None, None]: while True: yield start start += 1 Alternatively, annotate your generator as having a return type of either ‘Iterable[YieldType]’ or ‘Iterator[YieldType]’: def infinite_stream(start: int) -> Iterator[int]: while True: yield start start += 1 -- Class: typing.AsyncGenerator (AsyncIterator[T_co], Generic[T_co, T_contra]) An async generator can be annotated by the generic type ‘AsyncGenerator[YieldType, SendType]’. For example: async def echo_round() -> AsyncGenerator[int, float]: sent = yield 0 while sent >= 0.0: rounded = await round(sent) sent = yield rounded Unlike normal generators, async generators cannot return a value, so there is no ‘ReturnType’ type parameter. As with *note Generator: 2fa7, the ‘SendType’ behaves contravariantly. If your generator will only yield values, set the ‘SendType’ to ‘None’: async def infinite_stream(start: int) -> AsyncGenerator[int, None]: while True: yield start start = await increment(start) Alternatively, annotate your generator as having a return type of either ‘AsyncIterable[YieldType]’ or ‘AsyncIterator[YieldType]’: async def infinite_stream(start: int) -> AsyncIterator[int]: while True: yield start start = await increment(start) New in version 3.6.1. -- Class: typing.Text ‘Text’ is an alias for ‘str’. It is provided to supply a forward compatible path for Python 2 code: in Python 2, ‘Text’ is an alias for ‘unicode’. Use ‘Text’ to indicate that a value must contain a unicode string in a manner that is compatible with both Python 2 and Python 3: def add_unicode_checkmark(text: Text) -> Text: return text + u' \u2713' New in version 3.5.2. -- Class: typing.IO -- Class: typing.TextIO -- Class: typing.BinaryIO Generic type ‘IO[AnyStr]’ and its subclasses ‘TextIO(IO[str])’ and ‘BinaryIO(IO[bytes])’ represent the types of I/O streams such as returned by *note open(): 4f0. -- Class: typing.Pattern -- Class: typing.Match These type aliases correspond to the return types from *note re.compile(): 44a. and *note re.match(): bb3. These types (and the corresponding functions) are generic in ‘AnyStr’ and can be made specific by writing ‘Pattern[str]’, ‘Pattern[bytes]’, ‘Match[str]’, or ‘Match[bytes]’. -- Class: typing.NamedTuple Typed version of *note collections.namedtuple(): 1b7. Usage: class Employee(NamedTuple): name: str id: int This is equivalent to: Employee = collections.namedtuple('Employee', ['name', 'id']) To give a field a default value, you can assign to it in the class body: class Employee(NamedTuple): name: str id: int = 3 employee = Employee('Guido') assert employee.id == 3 Fields with a default value must come after any fields without a default. The resulting class has an extra attribute ‘__annotations__’ giving a dict that maps the field names to the field types. (The field names are in the ‘_fields’ attribute and the default values are in the ‘_field_defaults’ attribute both of which are part of the namedtuple API.) ‘NamedTuple’ subclasses can also have docstrings and methods: class Employee(NamedTuple): """Represents an employee.""" name: str id: int = 3 def __repr__(self) -> str: return f'<Employee {self.name}, id={self.id}>' Backward-compatible usage: Employee = NamedTuple('Employee', [('name', str), ('id', int)]) Changed in version 3.6: Added support for PEP 526(5) variable annotation syntax. Changed in version 3.6.1: Added support for default values, methods, and docstrings. Deprecated since version 3.8, will be removed in version 3.9: Deprecated the ‘_field_types’ attribute in favor of the more standard ‘__annotations__’ attribute which has the same information. Changed in version 3.8: The ‘_field_types’ and ‘__annotations__’ attributes are now regular dictionaries instead of instances of ‘OrderedDict’. -- Class: typing.TypedDict (dict) A simple typed namespace. At runtime it is equivalent to a plain *note dict: 1b8. ‘TypedDict’ creates a dictionary type that expects all of its instances to have a certain set of keys, where each key is associated with a value of a consistent type. This expectation is not checked at runtime but is only enforced by type checkers. Usage: class Point2D(TypedDict): x: int y: int label: str a: Point2D = {'x': 1, 'y': 2, 'label': 'good'} # OK b: Point2D = {'z': 3, 'label': 'bad'} # Fails type check assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first') The type info for introspection can be accessed via ‘Point2D.__annotations__’ and ‘Point2D.__total__’. To allow using this feature with older versions of Python that do not support PEP 526(6), ‘TypedDict’ supports two additional equivalent syntactic forms: Point2D = TypedDict('Point2D', x=int, y=int, label=str) Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str}) By default, all keys must be present in a TypedDict. It is possible to override this by specifying totality. Usage: class point2D(TypedDict, total=False): x: int y: int This means that a point2D TypedDict can have any of the keys omitted. A type checker is only expected to support a literal False or True as the value of the total argument. True is the default, and makes all items defined in the class body be required. See PEP 589(7) for more examples and detailed rules of using ‘TypedDict’. New in version 3.8. -- Class: typing.ForwardRef A class used for internal typing representation of string forward references. For example, ‘List["SomeClass"]’ is implicitly transformed into ‘List[ForwardRef("SomeClass")]’. This class should not be instantiated by a user, but may be used by introspection tools. New in version 3.7.4. -- Function: typing.NewType (name, tp) A helper function to indicate a distinct type to a typechecker, see *note NewType: 2f81. At runtime it returns a function that returns its argument. Usage: UserId = NewType('UserId', int) first_user = UserId(1) New in version 3.5.2. -- Function: typing.cast (typ, val) Cast a value to a type. This returns the value unchanged. To the type checker this signals that the return value has the designated type, but at runtime we intentionally don’t check anything (we want this to be as fast as possible). -- Function: typing.get_type_hints (obj[, globals[, locals]]) Return a dictionary containing type hints for a function, method, module or class object. This is often the same as ‘obj.__annotations__’. In addition, forward references encoded as string literals are handled by evaluating them in ‘globals’ and ‘locals’ namespaces. If necessary, ‘Optional[t]’ is added for function and method annotations if a default value equal to ‘None’ is set. For a class ‘C’, return a dictionary constructed by merging all the ‘__annotations__’ along ‘C.__mro__’ in reverse order. -- Function: typing.get_origin (tp) -- Function: typing.get_args (tp) Provide basic introspection for generic types and special typing forms. For a typing object of the form ‘X[Y, Z, ...]’ these functions return ‘X’ and ‘(Y, Z, ...)’. If ‘X’ is a generic alias for a builtin or *note collections: 1e. class, it gets normalized to the original class. For unsupported objects return ‘None’ and ‘()’ correspondingly. Examples: assert get_origin(Dict[str, int]) is dict assert get_args(Dict[int, str]) == (int, str) assert get_origin(Union[int, str]) is Union assert get_args(Union[int, str]) == (int, str) New in version 3.8. -- Function: @typing.overload The ‘@overload’ decorator allows describing functions and methods that support multiple different combinations of argument types. A series of ‘@overload’-decorated definitions must be followed by exactly one non-‘@overload’-decorated definition (for the same function/method). The ‘@overload’-decorated definitions are for the benefit of the type checker only, since they will be overwritten by the non-‘@overload’-decorated definition, while the latter is used at runtime but should be ignored by a type checker. At runtime, calling a ‘@overload’-decorated function directly will raise *note NotImplementedError: 60e. An example of overload that gives a more precise type than can be expressed using a union or a type variable: @overload def process(response: None) -> None: ... @overload def process(response: int) -> Tuple[int, str]: ... @overload def process(response: bytes) -> str: ... def process(response): <actual implementation> See PEP 484(8) for details and comparison with other typing semantics. -- Function: @typing.final A decorator to indicate to type checkers that the decorated method cannot be overridden, and the decorated class cannot be subclassed. For example: class Base: @final def done(self) -> None: ... class Sub(Base): def done(self) -> None: # Error reported by type checker ... @final class Leaf: ... class Other(Leaf): # Error reported by type checker ... There is no runtime checking of these properties. See PEP 591(9) for more details. New in version 3.8. -- Function: @typing.no_type_check Decorator to indicate that annotations are not type hints. This works as class or function *note decorator: 283. With a class, it applies recursively to all methods defined in that class (but not to methods defined in its superclasses or subclasses). This mutates the function(s) in place. -- Function: @typing.no_type_check_decorator Decorator to give another decorator the *note no_type_check(): 2fba. effect. This wraps the decorator with something that wraps the decorated function in *note no_type_check(): 2fba. -- Function: @typing.type_check_only Decorator to mark a class or function to be unavailable at runtime. This decorator is itself not available at runtime. It is mainly intended to mark classes that are defined in type stub files if an implementation returns an instance of a private class: @type_check_only class Response: # private or not available at runtime code: int def get_header(self, name: str) -> str: ... def fetch_response() -> Response: ... Note that returning instances of private classes is not recommended. It is usually preferable to make such classes public. -- Function: @typing.runtime_checkable Mark a protocol class as a runtime protocol. Such a protocol can be used with *note isinstance(): 44f. and *note issubclass(): 450. This raises *note TypeError: 192. when applied to a non-protocol class. This allows a simple-minded structural check, very similar to “one trick ponies” in *note collections.abc: 1f. such as *note Iterable: 1601. For example: @runtime_checkable class Closable(Protocol): def close(self): ... assert isinstance(open('/some/file'), Closable) `Warning:' this will check only the presence of the required methods, not their type signatures! New in version 3.8. -- Data: typing.Any Special type indicating an unconstrained type. * Every type is compatible with *note Any: 652. * *note Any: 652. is compatible with every type. -- Data: typing.NoReturn Special type indicating that a function never returns. For example: from typing import NoReturn def stop() -> NoReturn: raise RuntimeError('no way') New in version 3.5.4. New in version 3.6.2. -- Data: typing.Union Union type; ‘Union[X, Y]’ means either X or Y. To define a union, use e.g. ‘Union[int, str]’. Details: * The arguments must be types and there must be at least one. * Unions of unions are flattened, e.g.: Union[Union[int, str], float] == Union[int, str, float] * Unions of a single argument vanish, e.g.: Union[int] == int # The constructor actually returns int * Redundant arguments are skipped, e.g.: Union[int, str, int] == Union[int, str] * When comparing unions, the argument order is ignored, e.g.: Union[int, str] == Union[str, int] * You cannot subclass or instantiate a union. * You cannot write ‘Union[X][Y]’. * You can use ‘Optional[X]’ as a shorthand for ‘Union[X, None]’. Changed in version 3.7: Don’t remove explicit subclasses from unions at runtime. -- Data: typing.Optional Optional type. ‘Optional[X]’ is equivalent to ‘Union[X, None]’. Note that this is not the same concept as an optional argument, which is one that has a default. An optional argument with a default does not require the ‘Optional’ qualifier on its type annotation just because it is optional. For example: def foo(arg: int = 0) -> None: ... On the other hand, if an explicit value of ‘None’ is allowed, the use of ‘Optional’ is appropriate, whether the argument is optional or not. For example: def foo(arg: Optional[int] = None) -> None: ... -- Data: typing.Tuple Tuple type; ‘Tuple[X, Y]’ is the type of a tuple of two items with the first item of type X and the second of type Y. The type of the empty tuple can be written as ‘Tuple[()]’. Example: ‘Tuple[T1, T2]’ is a tuple of two elements corresponding to type variables T1 and T2. ‘Tuple[int, float, str]’ is a tuple of an int, a float and a string. To specify a variable-length tuple of homogeneous type, use literal ellipsis, e.g. ‘Tuple[int, ...]’. A plain *note Tuple: 2f7c. is equivalent to ‘Tuple[Any, ...]’, and in turn to *note tuple: 47e. -- Data: typing.Callable Callable type; ‘Callable[[int], str]’ is a function of (int) -> str. The subscription syntax must always be used with exactly two values: the argument list and the return type. The argument list must be a list of types or an ellipsis; the return type must be a single type. There is no syntax to indicate optional or keyword arguments; such function types are rarely used as callback types. ‘Callable[..., ReturnType]’ (literal ellipsis) can be used to type hint a callable taking any number of arguments and returning ‘ReturnType’. A plain *note Callable: 2f7d. is equivalent to ‘Callable[..., Any]’, and in turn to *note collections.abc.Callable: 1604. -- Data: typing.Literal A type that can be used to indicate to type checkers that the corresponding variable or function parameter has a value equivalent to the provided literal (or one of several literals). For example: def validate_simple(data: Any) -> Literal[True]: # always returns True ... MODE = Literal['r', 'rb', 'w', 'wb'] def open_helper(file: str, mode: MODE) -> str: ... open_helper('/some/path', 'r') # Passes type check open_helper('/other/path', 'typo') # Error in type checker ‘Literal[...]’ cannot be subclassed. At runtime, an arbitrary value is allowed as type argument to ‘Literal[...]’, but type checkers may impose restrictions. See PEP 586(10) for more details about literal types. New in version 3.8. -- Data: typing.ClassVar Special type construct to mark class variables. As introduced in PEP 526(11), a variable annotation wrapped in ClassVar indicates that a given attribute is intended to be used as a class variable and should not be set on instances of that class. Usage: class Starship: stats: ClassVar[Dict[str, int]] = {} # class variable damage: int = 10 # instance variable *note ClassVar: 5a3. accepts only types and cannot be further subscribed. *note ClassVar: 5a3. is not a class itself, and should not be used with *note isinstance(): 44f. or *note issubclass(): 450. *note ClassVar: 5a3. does not change Python runtime behavior, but it can be used by third-party type checkers. For example, a type checker might flag the following code as an error: enterprise_d = Starship(3000) enterprise_d.stats = {} # Error, setting class variable on instance Starship.stats = {} # This is OK New in version 3.5.3. -- Data: typing.Final A special typing construct to indicate to type checkers that a name cannot be re-assigned or overridden in a subclass. For example: MAX_SIZE: Final = 9000 MAX_SIZE += 1 # Error reported by type checker class Connection: TIMEOUT: Final[int] = 10 class FastConnector(Connection): TIMEOUT = 1 # Error reported by type checker There is no runtime checking of these properties. See PEP 591(12) for more details. New in version 3.8. -- Data: typing.AnyStr ‘AnyStr’ is a type variable defined as ‘AnyStr = TypeVar('AnyStr', str, bytes)’. It is meant to be used for functions that may accept any kind of string without allowing different kinds of strings to mix. For example: def concat(a: AnyStr, b: AnyStr) -> AnyStr: return a + b concat(u"foo", u"bar") # Ok, output has type 'unicode' concat(b"foo", b"bar") # Ok, output has type 'bytes' concat(u"foo", b"bar") # Error, cannot mix unicode and bytes -- Data: typing.TYPE_CHECKING A special constant that is assumed to be ‘True’ by 3rd party static type checkers. It is ‘False’ at runtime. Usage: if TYPE_CHECKING: import expensive_mod def fun(arg: 'expensive_mod.SomeType') -> None: local_var: expensive_mod.AnotherType = other_fun() Note that the first type annotation must be enclosed in quotes, making it a “forward reference”, to hide the ‘expensive_mod’ reference from the interpreter runtime. Type annotations for local variables are not evaluated, so the second annotation does not need to be enclosed in quotes. New in version 3.5.2. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0484 (3) https://www.python.org/dev/peps/pep-0544 (4) https://www.python.org/dev/peps/pep-0484 (5) https://www.python.org/dev/peps/pep-0526 (6) https://www.python.org/dev/peps/pep-0526 (7) https://www.python.org/dev/peps/pep-0589 (8) https://www.python.org/dev/peps/pep-0484 (9) https://www.python.org/dev/peps/pep-0591 (10) https://www.python.org/dev/peps/pep-0586 (11) https://www.python.org/dev/peps/pep-0526 (12) https://www.python.org/dev/peps/pep-0591  File: python.info, Node: pydoc — Documentation generator and online help system, Next: doctest — Test interactive Python examples, Prev: typing — Support for type hints, Up: Development Tools 5.26.2 ‘pydoc’ — Documentation generator and online help system --------------------------------------------------------------- `Source code:' Lib/pydoc.py(1) __________________________________________________________________ The *note pydoc: d9. module automatically generates documentation from Python modules. The documentation can be presented as pages of text on the console, served to a Web browser, or saved to HTML files. For modules, classes, functions and methods, the displayed documentation is derived from the docstring (i.e. the ‘__doc__’ attribute) of the object, and recursively of its documentable members. If there is no docstring, *note pydoc: d9. tries to obtain a description from the block of comment lines just above the definition of the class, function or method in the source file, or at the top of the module (see *note inspect.getcomments(): 2fc2.). The built-in function *note help(): 572. invokes the online help system in the interactive interpreter, which uses *note pydoc: d9. to generate its documentation as text on the console. The same text documentation can also be viewed from outside the Python interpreter by running ‘pydoc’ as a script at the operating system’s command prompt. For example, running pydoc sys at a shell prompt will display documentation on the *note sys: fd. module, in a style similar to the manual pages shown by the Unix ‘man’ command. The argument to ‘pydoc’ can be the name of a function, module, or package, or a dotted reference to a class, method, or function within a module or module in a package. If the argument to ‘pydoc’ looks like a path (that is, it contains the path separator for your operating system, such as a slash in Unix), and refers to an existing Python source file, then documentation is produced for that file. Note: In order to find objects and their documentation, *note pydoc: d9. imports the module(s) to be documented. Therefore, any code on module level will be executed on that occasion. Use an ‘if __name__ == '__main__':’ guard to only execute code when a file is invoked as a script and not just imported. When printing output to the console, ‘pydoc’ attempts to paginate the output for easier reading. If the ‘PAGER’ environment variable is set, ‘pydoc’ will use its value as a pagination program. Specifying a ‘-w’ flag before the argument will cause HTML documentation to be written out to a file in the current directory, instead of displaying text on the console. Specifying a ‘-k’ flag before the argument will search the synopsis lines of all available modules for the keyword given as the argument, again in a manner similar to the Unix ‘man’ command. The synopsis line of a module is the first line of its documentation string. You can also use ‘pydoc’ to start an HTTP server on the local machine that will serve documentation to visiting Web browsers. ‘pydoc -p 1234’ will start a HTTP server on port 1234, allowing you to browse the documentation at ‘http://localhost:1234/’ in your preferred Web browser. Specifying ‘0’ as the port number will select an arbitrary unused port. ‘pydoc -n <hostname>’ will start the server listening at the given hostname. By default the hostname is ‘localhost’ but if you want the server to be reached from other machines, you may want to change the host name that the server responds to. During development this is especially useful if you want to run pydoc from within a container. ‘pydoc -b’ will start the server and additionally open a web browser to a module index page. Each served page has a navigation bar at the top where you can `Get' help on an individual item, `Search' all modules with a keyword in their synopsis line, and go to the `Module index', `Topics' and `Keywords' pages. When ‘pydoc’ generates documentation, it uses the current environment and path to locate modules. Thus, invoking ‘pydoc spam’ documents precisely the version of the module you would get if you started the Python interpreter and typed ‘import spam’. Module docs for core modules are assumed to reside in ‘https://docs.python.org/X.Y/library/’ where ‘X’ and ‘Y’ are the major and minor version numbers of the Python interpreter. This can be overridden by setting the ‘PYTHONDOCS’ environment variable to a different URL or to a local directory containing the Library Reference Manual pages. Changed in version 3.2: Added the ‘-b’ option. Changed in version 3.3: The ‘-g’ command line option was removed. Changed in version 3.4: *note pydoc: d9. now uses *note inspect.signature(): 55b. rather than *note inspect.getfullargspec(): 55d. to extract signature information from callables. Changed in version 3.7: Added the ‘-n’ option. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pydoc.py  File: python.info, Node: doctest — Test interactive Python examples, Next: unittest — Unit testing framework, Prev: pydoc — Documentation generator and online help system, Up: Development Tools 5.26.3 ‘doctest’ — Test interactive Python examples --------------------------------------------------- `Source code:' Lib/doctest.py(1) __________________________________________________________________ The *note doctest: 67. module searches for pieces of text that look like interactive Python sessions, and then executes those sessions to verify that they work exactly as shown. There are several common ways to use doctest: * To check that a module’s docstrings are up-to-date by verifying that all interactive examples still work as documented. * To perform regression testing by verifying that interactive examples from a test file or a test object work as expected. * To write tutorial documentation for a package, liberally illustrated with input-output examples. Depending on whether the examples or the expository text are emphasized, this has the flavor of “literate testing” or “executable documentation”. Here’s a complete but small example module: """ This is the "example" module. The example module supplies one function, factorial(). For example, >>> factorial(5) 120 """ def factorial(n): """Return the factorial of n, an exact integer >= 0. >>> [factorial(n) for n in range(6)] [1, 1, 2, 6, 24, 120] >>> factorial(30) 265252859812191058636308480000000 >>> factorial(-1) Traceback (most recent call last): ... ValueError: n must be >= 0 Factorials of floats are OK, but the float must be an exact integer: >>> factorial(30.1) Traceback (most recent call last): ... ValueError: n must be exact integer >>> factorial(30.0) 265252859812191058636308480000000 It must also not be ridiculously large: >>> factorial(1e100) Traceback (most recent call last): ... OverflowError: n too large """ import math if not n >= 0: raise ValueError("n must be >= 0") if math.floor(n) != n: raise ValueError("n must be exact integer") if n+1 == n: # catch a value like 1e300 raise OverflowError("n too large") result = 1 factor = 2 while factor <= n: result *= factor factor += 1 return result if __name__ == "__main__": import doctest doctest.testmod() If you run ‘example.py’ directly from the command line, *note doctest: 67. works its magic: $ python example.py $ There’s no output! That’s normal, and it means all the examples worked. Pass ‘-v’ to the script, and *note doctest: 67. prints a detailed log of what it’s trying, and prints a summary at the end: $ python example.py -v Trying: factorial(5) Expecting: 120 ok Trying: [factorial(n) for n in range(6)] Expecting: [1, 1, 2, 6, 24, 120] ok And so on, eventually ending with: Trying: factorial(1e100) Expecting: Traceback (most recent call last): ... OverflowError: n too large ok 2 items passed all tests: 1 tests in __main__ 8 tests in __main__.factorial 9 tests in 2 items. 9 passed and 0 failed. Test passed. $ That’s all you need to know to start making productive use of *note doctest: 67.! Jump in. The following sections provide full details. Note that there are many examples of doctests in the standard Python test suite and libraries. Especially useful examples can be found in the standard test file ‘Lib/test/test_doctest.py’. * Menu: * Simple Usage; Checking Examples in Docstrings: Simple Usage Checking Examples in Docstrings. * Simple Usage; Checking Examples in a Text File: Simple Usage Checking Examples in a Text File. * How It Works:: * Basic API:: * Unittest API:: * Advanced API:: * Debugging:: * Soapbox:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/doctest.py  File: python.info, Node: Simple Usage Checking Examples in Docstrings, Next: Simple Usage Checking Examples in a Text File, Up: doctest — Test interactive Python examples 5.26.3.1 Simple Usage: Checking Examples in Docstrings ...................................................... The simplest way to start using doctest (but not necessarily the way you’ll continue to do it) is to end each module ‘M’ with: if __name__ == "__main__": import doctest doctest.testmod() *note doctest: 67. then examines docstrings in module ‘M’. Running the module as a script causes the examples in the docstrings to get executed and verified: python M.py This won’t display anything unless an example fails, in which case the failing example(s) and the cause(s) of the failure(s) are printed to stdout, and the final line of output is ‘***Test Failed*** N failures.’, where `N' is the number of examples that failed. Run it with the ‘-v’ switch instead: python M.py -v and a detailed report of all examples tried is printed to standard output, along with assorted summaries at the end. You can force verbose mode by passing ‘verbose=True’ to *note testmod(): dd0, or prohibit it by passing ‘verbose=False’. In either of those cases, ‘sys.argv’ is not examined by *note testmod(): dd0. (so passing ‘-v’ or not has no effect). There is also a command line shortcut for running *note testmod(): dd0. You can instruct the Python interpreter to run the doctest module directly from the standard library and pass the module name(s) on the command line: python -m doctest -v example.py This will import ‘example.py’ as a standalone module and run *note testmod(): dd0. on it. Note that this may not work correctly if the file is part of a package and imports other submodules from that package. For more information on *note testmod(): dd0, see section *note Basic API: 2fc7.  File: python.info, Node: Simple Usage Checking Examples in a Text File, Next: How It Works, Prev: Simple Usage Checking Examples in Docstrings, Up: doctest — Test interactive Python examples 5.26.3.2 Simple Usage: Checking Examples in a Text File ....................................................... Another simple application of doctest is testing interactive examples in a text file. This can be done with the *note testfile(): 2fca. function: import doctest doctest.testfile("example.txt") That short script executes and verifies any interactive Python examples contained in the file ‘example.txt’. The file content is treated as if it were a single giant docstring; the file doesn’t need to contain a Python program! For example, perhaps ‘example.txt’ contains this: The ``example`` module ====================== Using ``factorial`` ------------------- This is an example text file in reStructuredText format. First import ``factorial`` from the ``example`` module: >>> from example import factorial Now use it: >>> factorial(6) 120 Running ‘doctest.testfile("example.txt")’ then finds the error in this documentation: File "./example.txt", line 14, in example.txt Failed example: factorial(6) Expected: 120 Got: 720 As with *note testmod(): dd0, *note testfile(): 2fca. won’t display anything unless an example fails. If an example does fail, then the failing example(s) and the cause(s) of the failure(s) are printed to stdout, using the same format as *note testmod(): dd0. By default, *note testfile(): 2fca. looks for files in the calling module’s directory. See section *note Basic API: 2fc7. for a description of the optional arguments that can be used to tell it to look for files in other locations. Like *note testmod(): dd0, *note testfile(): 2fca.’s verbosity can be set with the ‘-v’ command-line switch or with the optional keyword argument `verbose'. There is also a command line shortcut for running *note testfile(): 2fca. You can instruct the Python interpreter to run the doctest module directly from the standard library and pass the file name(s) on the command line: python -m doctest -v example.txt Because the file name does not end with ‘.py’, *note doctest: 67. infers that it must be run with *note testfile(): 2fca, not *note testmod(): dd0. For more information on *note testfile(): 2fca, see section *note Basic API: 2fc7.  File: python.info, Node: How It Works, Next: Basic API, Prev: Simple Usage Checking Examples in a Text File, Up: doctest — Test interactive Python examples 5.26.3.3 How It Works ..................... This section examines in detail how doctest works: which docstrings it looks at, how it finds interactive examples, what execution context it uses, how it handles exceptions, and how option flags can be used to control its behavior. This is the information that you need to know to write doctest examples; for information about actually running doctest on these examples, see the following sections. * Menu: * Which Docstrings Are Examined?:: * How are Docstring Examples Recognized?:: * What’s the Execution Context?:: * What About Exceptions?:: * Option Flags:: * Directives:: * Warnings: Warnings<2>.  File: python.info, Node: Which Docstrings Are Examined?, Next: How are Docstring Examples Recognized?, Up: How It Works 5.26.3.4 Which Docstrings Are Examined? ....................................... The module docstring, and all function, class and method docstrings are searched. Objects imported into the module are not searched. In addition, if ‘M.__test__’ exists and “is true”, it must be a dict, and each entry maps a (string) name to a function object, class object, or string. Function and class object docstrings found from ‘M.__test__’ are searched, and strings are treated as if they were docstrings. In output, a key ‘K’ in ‘M.__test__’ appears with name <name of M>.__test__.K Any classes found are recursively searched similarly, to test docstrings in their contained methods and nested classes. `CPython implementation detail:' Prior to version 3.4, extension modules written in C were not fully searched by doctest.  File: python.info, Node: How are Docstring Examples Recognized?, Next: What’s the Execution Context?, Prev: Which Docstrings Are Examined?, Up: How It Works 5.26.3.5 How are Docstring Examples Recognized? ............................................... In most cases a copy-and-paste of an interactive console session works fine, but doctest isn’t trying to do an exact emulation of any specific Python shell. >>> # comments are ignored >>> x = 12 >>> x 12 >>> if x == 13: ... print("yes") ... else: ... print("no") ... print("NO") ... print("NO!!!") ... no NO NO!!! >>> Any expected output must immediately follow the final ‘'>>> '’ or ‘'... '’ line containing the code, and the expected output (if any) extends to the next ‘'>>> '’ or all-whitespace line. The fine print: * Expected output cannot contain an all-whitespace line, since such a line is taken to signal the end of expected output. If expected output does contain a blank line, put ‘<BLANKLINE>’ in your doctest example each place a blank line is expected. * All hard tab characters are expanded to spaces, using 8-column tab stops. Tabs in output generated by the tested code are not modified. Because any hard tabs in the sample output `are' expanded, this means that if the code output includes hard tabs, the only way the doctest can pass is if the *note NORMALIZE_WHITESPACE: 2fd1. option or *note directive: 2fd2. is in effect. Alternatively, the test can be rewritten to capture the output and compare it to an expected value as part of the test. This handling of tabs in the source was arrived at through trial and error, and has proven to be the least error prone way of handling them. It is possible to use a different algorithm for handling tabs by writing a custom *note DocTestParser: 2fd3. class. * Output to stdout is captured, but not output to stderr (exception tracebacks are captured via a different means). * If you continue a line via backslashing in an interactive session, or for any other reason use a backslash, you should use a raw docstring, which will preserve your backslashes exactly as you type them: >>> def f(x): ... r'''Backslashes in a raw docstring: m\n''' >>> print(f.__doc__) Backslashes in a raw docstring: m\n Otherwise, the backslash will be interpreted as part of the string. For example, the ‘\n’ above would be interpreted as a newline character. Alternatively, you can double each backslash in the doctest version (and not use a raw string): >>> def f(x): ... '''Backslashes in a raw docstring: m\\n''' >>> print(f.__doc__) Backslashes in a raw docstring: m\n * The starting column doesn’t matter: >>> assert "Easy!" >>> import math >>> math.floor(1.9) 1 and as many leading whitespace characters are stripped from the expected output as appeared in the initial ‘'>>> '’ line that started the example.  File: python.info, Node: What’s the Execution Context?, Next: What About Exceptions?, Prev: How are Docstring Examples Recognized?, Up: How It Works 5.26.3.6 What’s the Execution Context? ...................................... By default, each time *note doctest: 67. finds a docstring to test, it uses a `shallow copy' of ‘M’’s globals, so that running tests doesn’t change the module’s real globals, and so that one test in ‘M’ can’t leave behind crumbs that accidentally allow another test to work. This means examples can freely use any names defined at top-level in ‘M’, and names defined earlier in the docstring being run. Examples cannot see names defined in other docstrings. You can force use of your own dict as the execution context by passing ‘globs=your_dict’ to *note testmod(): dd0. or *note testfile(): 2fca. instead.  File: python.info, Node: What About Exceptions?, Next: Option Flags, Prev: What’s the Execution Context?, Up: How It Works 5.26.3.7 What About Exceptions? ............................... No problem, provided that the traceback is the only output produced by the example: just paste in the traceback. (1) Since tracebacks contain details that are likely to change rapidly (for example, exact file paths and line numbers), this is one case where doctest works hard to be flexible in what it accepts. Simple example: >>> [1, 2, 3].remove(42) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: list.remove(x): x not in list That doctest succeeds if *note ValueError: 1fb. is raised, with the ‘list.remove(x): x not in list’ detail as shown. The expected output for an exception must start with a traceback header, which may be either of the following two lines, indented the same as the first line of the example: Traceback (most recent call last): Traceback (innermost last): The traceback header is followed by an optional traceback stack, whose contents are ignored by doctest. The traceback stack is typically omitted, or copied verbatim from an interactive session. The traceback stack is followed by the most interesting part: the line(s) containing the exception type and detail. This is usually the last line of a traceback, but can extend across multiple lines if the exception has a multi-line detail: >>> raise ValueError('multi\n line\ndetail') Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: multi line detail The last three lines (starting with *note ValueError: 1fb.) are compared against the exception’s type and detail, and the rest are ignored. Best practice is to omit the traceback stack, unless it adds significant documentation value to the example. So the last example is probably better as: >>> raise ValueError('multi\n line\ndetail') Traceback (most recent call last): ... ValueError: multi line detail Note that tracebacks are treated very specially. In particular, in the rewritten example, the use of ‘...’ is independent of doctest’s *note ELLIPSIS: dd1. option. The ellipsis in that example could be left out, or could just as well be three (or three hundred) commas or digits, or an indented transcript of a Monty Python skit. Some details you should read once, but won’t need to remember: * Doctest can’t guess whether your expected output came from an exception traceback or from ordinary printing. So, e.g., an example that expects ‘ValueError: 42 is prime’ will pass whether *note ValueError: 1fb. is actually raised or if the example merely prints that traceback text. In practice, ordinary output rarely begins with a traceback header line, so this doesn’t create real problems. * Each line of the traceback stack (if present) must be indented further than the first line of the example, `or' start with a non-alphanumeric character. The first line following the traceback header indented the same and starting with an alphanumeric is taken to be the start of the exception detail. Of course this does the right thing for genuine tracebacks. * When the *note IGNORE_EXCEPTION_DETAIL: 2fd8. doctest option is specified, everything following the leftmost colon and any module information in the exception name is ignored. * The interactive shell omits the traceback header line for some *note SyntaxError: 458.s. But doctest uses the traceback header line to distinguish exceptions from non-exceptions. So in the rare case where you need to test a *note SyntaxError: 458. that omits the traceback header, you will need to manually add the traceback header line to your test example. * For some *note SyntaxError: 458.s, Python displays the character position of the syntax error, using a ‘^’ marker: >>> 1 1 File "<stdin>", line 1 1 1 ^ SyntaxError: invalid syntax Since the lines showing the position of the error come before the exception type and detail, they are not checked by doctest. For example, the following test would pass, even though it puts the ‘^’ marker in the wrong location: >>> 1 1 Traceback (most recent call last): File "<stdin>", line 1 1 1 ^ SyntaxError: invalid syntax ---------- Footnotes ---------- (1) (1) Examples containing both expected output and an exception are not supported. Trying to guess where one ends and the other begins is too error-prone, and that also makes for a confusing test.  File: python.info, Node: Option Flags, Next: Directives, Prev: What About Exceptions?, Up: How It Works 5.26.3.8 Option Flags ..................... A number of option flags control various aspects of doctest’s behavior. Symbolic names for the flags are supplied as module constants, which can be *note bitwise ORed: 11e4. together and passed to various functions. The names can also be used in *note doctest directives: 2fd2, and may be passed to the doctest command line interface via the ‘-o’ option. New in version 3.4: The ‘-o’ command line option. The first group of options define test semantics, controlling aspects of how doctest decides whether actual output matches an example’s expected output: -- Data: doctest.DONT_ACCEPT_TRUE_FOR_1 By default, if an expected output block contains just ‘1’, an actual output block containing just ‘1’ or just ‘True’ is considered to be a match, and similarly for ‘0’ versus ‘False’. When *note DONT_ACCEPT_TRUE_FOR_1: 2fdb. is specified, neither substitution is allowed. The default behavior caters to that Python changed the return type of many functions from integer to boolean; doctests expecting “little integer” output still work in these cases. This option will probably go away, but not for several years. -- Data: doctest.DONT_ACCEPT_BLANKLINE By default, if an expected output block contains a line containing only the string ‘<BLANKLINE>’, then that line will match a blank line in the actual output. Because a genuinely blank line delimits the expected output, this is the only way to communicate that a blank line is expected. When *note DONT_ACCEPT_BLANKLINE: 2fdc. is specified, this substitution is not allowed. -- Data: doctest.NORMALIZE_WHITESPACE When specified, all sequences of whitespace (blanks and newlines) are treated as equal. Any sequence of whitespace within the expected output will match any sequence of whitespace within the actual output. By default, whitespace must match exactly. *note NORMALIZE_WHITESPACE: 2fd1. is especially useful when a line of expected output is very long, and you want to wrap it across multiple lines in your source. -- Data: doctest.ELLIPSIS When specified, an ellipsis marker (‘...’) in the expected output can match any substring in the actual output. This includes substrings that span line boundaries, and empty substrings, so it’s best to keep usage of this simple. Complicated uses can lead to the same kinds of “oops, it matched too much!” surprises that ‘.*’ is prone to in regular expressions. -- Data: doctest.IGNORE_EXCEPTION_DETAIL When specified, an example that expects an exception passes if an exception of the expected type is raised, even if the exception detail does not match. For example, an example expecting ‘ValueError: 42’ will pass if the actual exception raised is ‘ValueError: 3*14’, but will fail, e.g., if *note TypeError: 192. is raised. It will also ignore the module name used in Python 3 doctest reports. Hence both of these variations will work with the flag specified, regardless of whether the test is run under Python 2.7 or Python 3.2 (or later versions): >>> raise CustomError('message') Traceback (most recent call last): CustomError: message >>> raise CustomError('message') Traceback (most recent call last): my_module.CustomError: message Note that *note ELLIPSIS: dd1. can also be used to ignore the details of the exception message, but such a test may still fail based on whether or not the module details are printed as part of the exception name. Using *note IGNORE_EXCEPTION_DETAIL: 2fd8. and the details from Python 2.3 is also the only clear way to write a doctest that doesn’t care about the exception detail yet continues to pass under Python 2.3 or earlier (those releases do not support *note doctest directives: 2fd2. and ignore them as irrelevant comments). For example: >>> (1, 2)[3] = 'moo' Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: object doesn't support item assignment passes under Python 2.3 and later Python versions with the flag specified, even though the detail changed in Python 2.4 to say “does not” instead of “doesn’t”. Changed in version 3.2: *note IGNORE_EXCEPTION_DETAIL: 2fd8. now also ignores any information relating to the module containing the exception under test. -- Data: doctest.SKIP When specified, do not run the example at all. This can be useful in contexts where doctest examples serve as both documentation and test cases, and an example should be included for documentation purposes, but should not be checked. E.g., the example’s output might be random; or the example might depend on resources which would be unavailable to the test driver. The SKIP flag can also be used for temporarily “commenting out” examples. -- Data: doctest.COMPARISON_FLAGS A bitmask or’ing together all the comparison flags above. The second group of options controls how test failures are reported: -- Data: doctest.REPORT_UDIFF When specified, failures that involve multi-line expected and actual outputs are displayed using a unified diff. -- Data: doctest.REPORT_CDIFF When specified, failures that involve multi-line expected and actual outputs will be displayed using a context diff. -- Data: doctest.REPORT_NDIFF When specified, differences are computed by ‘difflib.Differ’, using the same algorithm as the popular ‘ndiff.py’ utility. This is the only method that marks differences within lines as well as across lines. For example, if a line of expected output contains digit ‘1’ where actual output contains letter ‘l’, a line is inserted with a caret marking the mismatching column positions. -- Data: doctest.REPORT_ONLY_FIRST_FAILURE When specified, display the first failing example in each doctest, but suppress output for all remaining examples. This will prevent doctest from reporting correct examples that break because of earlier failures; but it might also hide incorrect examples that fail independently of the first failure. When *note REPORT_ONLY_FIRST_FAILURE: 2fdf. is specified, the remaining examples are still run, and still count towards the total number of failures reported; only the output is suppressed. -- Data: doctest.FAIL_FAST When specified, exit after the first failing example and don’t attempt to run the remaining examples. Thus, the number of failures reported will be at most 1. This flag may be useful during debugging, since examples after the first failure won’t even produce debugging output. The doctest command line accepts the option ‘-f’ as a shorthand for ‘-o FAIL_FAST’. New in version 3.4. -- Data: doctest.REPORTING_FLAGS A bitmask or’ing together all the reporting flags above. There is also a way to register new option flag names, though this isn’t useful unless you intend to extend *note doctest: 67. internals via subclassing: -- Function: doctest.register_optionflag (name) Create a new option flag with a given name, and return the new flag’s integer value. *note register_optionflag(): 2fe1. can be used when subclassing *note OutputChecker: 2fe2. or *note DocTestRunner: 2fe3. to create new options that are supported by your subclasses. *note register_optionflag(): 2fe1. should always be called using the following idiom: MY_FLAG = register_optionflag('MY_FLAG')  File: python.info, Node: Directives, Next: Warnings<2>, Prev: Option Flags, Up: How It Works 5.26.3.9 Directives ................... Doctest directives may be used to modify the *note option flags: 83c. for an individual example. Doctest directives are special Python comments following an example’s source code: directive ::= "#" "doctest:" directive_options directive_options ::= directive_option ("," directive_option)\* directive_option ::= on_or_off directive_option_name on_or_off ::= "+" \| "-" directive_option_name ::= "DONT_ACCEPT_BLANKLINE" \| "NORMALIZE_WHITESPACE" \| ... Whitespace is not allowed between the ‘+’ or ‘-’ and the directive option name. The directive option name can be any of the option flag names explained above. An example’s doctest directives modify doctest’s behavior for that single example. Use ‘+’ to enable the named behavior, or ‘-’ to disable it. For example, this test passes: >>> print(list(range(20))) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19] Without the directive it would fail, both because the actual output doesn’t have two blanks before the single-digit list elements, and because the actual output is on a single line. This test also passes, and also requires a directive to do so: >>> print(list(range(20))) [0, 1, ..., 18, 19] Multiple directives can be used on a single physical line, separated by commas: >>> print(list(range(20))) [0, 1, ..., 18, 19] If multiple directive comments are used for a single example, then they are combined: >>> print(list(range(20))) ... [0, 1, ..., 18, 19] As the previous example shows, you can add ‘...’ lines to your example containing only directives. This can be useful when an example is too long for a directive to comfortably fit on the same line: >>> print(list(range(5)) + list(range(10, 20)) + list(range(30, 40))) ... [0, ..., 4, 10, ..., 19, 30, ..., 39] Note that since all options are disabled by default, and directives apply only to the example they appear in, enabling options (via ‘+’ in a directive) is usually the only meaningful choice. However, option flags can also be passed to functions that run doctests, establishing different defaults. In such cases, disabling an option via ‘-’ in a directive can be useful.  File: python.info, Node: Warnings<2>, Prev: Directives, Up: How It Works 5.26.3.10 Warnings .................. *note doctest: 67. is serious about requiring exact matches in expected output. If even a single character doesn’t match, the test fails. This will probably surprise you a few times, as you learn exactly what Python does and doesn’t guarantee about output. For example, when printing a set, Python doesn’t guarantee that the element is printed in any particular order, so a test like >>> foo() {"Hermione", "Harry"} is vulnerable! One workaround is to do >>> foo() == {"Hermione", "Harry"} True instead. Another is to do >>> d = sorted(foo()) >>> d ['Harry', 'Hermione'] Note: Before Python 3.6, when printing a dict, Python did not guarantee that the key-value pairs was printed in any particular order. There are others, but you get the idea. Another bad idea is to print things that embed an object address, like >>> id(1.0) # certain to fail some of the time 7948648 >>> class C: pass >>> C() # the default repr() for instances embeds an address <__main__.C instance at 0x00AC18F0> The *note ELLIPSIS: dd1. directive gives a nice approach for the last example: >>> C() <__main__.C instance at 0x...> Floating-point numbers are also subject to small output variations across platforms, because Python defers to the platform C library for float formatting, and C libraries vary widely in quality here. >>> 1./7 # risky 0.14285714285714285 >>> print(1./7) # safer 0.142857142857 >>> print(round(1./7, 6)) # much safer 0.142857 Numbers of the form ‘I/2.**J’ are safe across all platforms, and I often contrive doctest examples to produce numbers of that form: >>> 3./4 # utterly safe 0.75 Simple fractions are also easier for people to understand, and that makes for better documentation.  File: python.info, Node: Basic API, Next: Unittest API, Prev: How It Works, Up: doctest — Test interactive Python examples 5.26.3.11 Basic API ................... The functions *note testmod(): dd0. and *note testfile(): 2fca. provide a simple interface to doctest that should be sufficient for most basic uses. For a less formal introduction to these two functions, see sections *note Simple Usage; Checking Examples in Docstrings: 2fc5. and *note Simple Usage; Checking Examples in a Text File: 2fc8. -- Function: doctest.testfile (filename, module_relative=True, name=None, package=None, globs=None, verbose=None, report=True, optionflags=0, extraglobs=None, raise_on_error=False, parser=DocTestParser(), encoding=None) All arguments except `filename' are optional, and should be specified in keyword form. Test examples in the file named `filename'. Return ‘(failure_count, test_count)’. Optional argument `module_relative' specifies how the filename should be interpreted: * If `module_relative' is ‘True’ (the default), then `filename' specifies an OS-independent module-relative path. By default, this path is relative to the calling module’s directory; but if the `package' argument is specified, then it is relative to that package. To ensure OS-independence, `filename' should use ‘/’ characters to separate path segments, and may not be an absolute path (i.e., it may not begin with ‘/’). * If `module_relative' is ‘False’, then `filename' specifies an OS-specific path. The path may be absolute or relative; relative paths are resolved with respect to the current working directory. Optional argument `name' gives the name of the test; by default, or if ‘None’, ‘os.path.basename(filename)’ is used. Optional argument `package' is a Python package or the name of a Python package whose directory should be used as the base directory for a module-relative filename. If no package is specified, then the calling module’s directory is used as the base directory for module-relative filenames. It is an error to specify `package' if `module_relative' is ‘False’. Optional argument `globs' gives a dict to be used as the globals when executing examples. A new shallow copy of this dict is created for the doctest, so its examples start with a clean slate. By default, or if ‘None’, a new empty dict is used. Optional argument `extraglobs' gives a dict merged into the globals used to execute examples. This works like *note dict.update(): dc9.: if `globs' and `extraglobs' have a common key, the associated value in `extraglobs' appears in the combined dict. By default, or if ‘None’, no extra globals are used. This is an advanced feature that allows parameterization of doctests. For example, a doctest can be written for a base class, using a generic name for the class, then reused to test any number of subclasses by passing an `extraglobs' dict mapping the generic name to the subclass to be tested. Optional argument `verbose' prints lots of stuff if true, and prints only failures if false; by default, or if ‘None’, it’s true if and only if ‘'-v'’ is in ‘sys.argv’. Optional argument `report' prints a summary at the end when true, else prints nothing at the end. In verbose mode, the summary is detailed, else the summary is very brief (in fact, empty if all tests passed). Optional argument `optionflags' (default value 0) takes the *note bitwise OR: 11e4. of option flags. See section *note Option Flags: 83c. Optional argument `raise_on_error' defaults to false. If true, an exception is raised upon the first failure or unexpected exception in an example. This allows failures to be post-mortem debugged. Default behavior is to continue running examples. Optional argument `parser' specifies a *note DocTestParser: 2fd3. (or subclass) that should be used to extract tests from the files. It defaults to a normal parser (i.e., ‘DocTestParser()’). Optional argument `encoding' specifies an encoding that should be used to convert the file to unicode. -- Function: doctest.testmod (m=None, name=None, globs=None, verbose=None, report=True, optionflags=0, extraglobs=None, raise_on_error=False, exclude_empty=False) All arguments are optional, and all except for `m' should be specified in keyword form. Test examples in docstrings in functions and classes reachable from module `m' (or module *note __main__: 1. if `m' is not supplied or is ‘None’), starting with ‘m.__doc__’. Also test examples reachable from dict ‘m.__test__’, if it exists and is not ‘None’. ‘m.__test__’ maps names (strings) to functions, classes and strings; function and class docstrings are searched for examples; strings are searched directly, as if they were docstrings. Only docstrings attached to objects belonging to module `m' are searched. Return ‘(failure_count, test_count)’. Optional argument `name' gives the name of the module; by default, or if ‘None’, ‘m.__name__’ is used. Optional argument `exclude_empty' defaults to false. If true, objects for which no doctests are found are excluded from consideration. The default is a backward compatibility hack, so that code still using ‘doctest.master.summarize()’ in conjunction with *note testmod(): dd0. continues to get output for objects with no tests. The `exclude_empty' argument to the newer *note DocTestFinder: 2fed. constructor defaults to true. Optional arguments `extraglobs', `verbose', `report', `optionflags', `raise_on_error', and `globs' are the same as for function *note testfile(): 2fca. above, except that `globs' defaults to ‘m.__dict__’. -- Function: doctest.run_docstring_examples (f, globs, verbose=False, name="NoName", compileflags=None, optionflags=0) Test examples associated with object `f'; for example, `f' may be a string, a module, a function, or a class object. A shallow copy of dictionary argument `globs' is used for the execution context. Optional argument `name' is used in failure messages, and defaults to ‘"NoName"’. If optional argument `verbose' is true, output is generated even if there are no failures. By default, output is generated only in case of an example failure. Optional argument `compileflags' gives the set of flags that should be used by the Python compiler when running the examples. By default, or if ‘None’, flags are deduced corresponding to the set of future features found in `globs'. Optional argument `optionflags' works as for function *note testfile(): 2fca. above.  File: python.info, Node: Unittest API, Next: Advanced API, Prev: Basic API, Up: doctest — Test interactive Python examples 5.26.3.12 Unittest API ...................... As your collection of doctest’ed modules grows, you’ll want a way to run all their doctests systematically. *note doctest: 67. provides two functions that can be used to create *note unittest: 11b. test suites from modules and text files containing doctests. To integrate with *note unittest: 11b. test discovery, include a ‘load_tests()’ function in your test module: import unittest import doctest import my_module_with_doctests def load_tests(loader, tests, ignore): tests.addTests(doctest.DocTestSuite(my_module_with_doctests)) return tests There are two main functions for creating *note unittest.TestSuite: 6ce. instances from text files and modules with doctests: -- Function: doctest.DocFileSuite (*paths, module_relative=True, package=None, setUp=None, tearDown=None, globs=None, optionflags=0, parser=DocTestParser(), encoding=None) Convert doctest tests from one or more text files to a *note unittest.TestSuite: 6ce. The returned *note unittest.TestSuite: 6ce. is to be run by the unittest framework and runs the interactive examples in each file. If an example in any file fails, then the synthesized unit test fails, and a ‘failureException’ exception is raised showing the name of the file containing the test and a (sometimes approximate) line number. Pass one or more paths (as strings) to text files to be examined. Options may be provided as keyword arguments: Optional argument `module_relative' specifies how the filenames in `paths' should be interpreted: * If `module_relative' is ‘True’ (the default), then each filename in `paths' specifies an OS-independent module-relative path. By default, this path is relative to the calling module’s directory; but if the `package' argument is specified, then it is relative to that package. To ensure OS-independence, each filename should use ‘/’ characters to separate path segments, and may not be an absolute path (i.e., it may not begin with ‘/’). * If `module_relative' is ‘False’, then each filename in `paths' specifies an OS-specific path. The path may be absolute or relative; relative paths are resolved with respect to the current working directory. Optional argument `package' is a Python package or the name of a Python package whose directory should be used as the base directory for module-relative filenames in `paths'. If no package is specified, then the calling module’s directory is used as the base directory for module-relative filenames. It is an error to specify `package' if `module_relative' is ‘False’. Optional argument `setUp' specifies a set-up function for the test suite. This is called before running the tests in each file. The `setUp' function will be passed a *note DocTest: 2ff2. object. The setUp function can access the test globals as the `globs' attribute of the test passed. Optional argument `tearDown' specifies a tear-down function for the test suite. This is called after running the tests in each file. The `tearDown' function will be passed a *note DocTest: 2ff2. object. The setUp function can access the test globals as the `globs' attribute of the test passed. Optional argument `globs' is a dictionary containing the initial global variables for the tests. A new copy of this dictionary is created for each test. By default, `globs' is a new empty dictionary. Optional argument `optionflags' specifies the default doctest options for the tests, created by or-ing together individual option flags. See section *note Option Flags: 83c. See function *note set_unittest_reportflags(): 2ff3. below for a better way to set reporting options. Optional argument `parser' specifies a *note DocTestParser: 2fd3. (or subclass) that should be used to extract tests from the files. It defaults to a normal parser (i.e., ‘DocTestParser()’). Optional argument `encoding' specifies an encoding that should be used to convert the file to unicode. The global ‘__file__’ is added to the globals provided to doctests loaded from a text file using *note DocFileSuite(): 2ff1. -- Function: doctest.DocTestSuite (module=None, globs=None, extraglobs=None, test_finder=None, setUp=None, tearDown=None, checker=None) Convert doctest tests for a module to a *note unittest.TestSuite: 6ce. The returned *note unittest.TestSuite: 6ce. is to be run by the unittest framework and runs each doctest in the module. If any of the doctests fail, then the synthesized unit test fails, and a ‘failureException’ exception is raised showing the name of the file containing the test and a (sometimes approximate) line number. Optional argument `module' provides the module to be tested. It can be a module object or a (possibly dotted) module name. If not specified, the module calling this function is used. Optional argument `globs' is a dictionary containing the initial global variables for the tests. A new copy of this dictionary is created for each test. By default, `globs' is a new empty dictionary. Optional argument `extraglobs' specifies an extra set of global variables, which is merged into `globs'. By default, no extra globals are used. Optional argument `test_finder' is the *note DocTestFinder: 2fed. object (or a drop-in replacement) that is used to extract doctests from the module. Optional arguments `setUp', `tearDown', and `optionflags' are the same as for function *note DocFileSuite(): 2ff1. above. This function uses the same search technique as *note testmod(): dd0. Changed in version 3.5: *note DocTestSuite(): 6cd. returns an empty *note unittest.TestSuite: 6ce. if `module' contains no docstrings instead of raising *note ValueError: 1fb. Under the covers, *note DocTestSuite(): 6cd. creates a *note unittest.TestSuite: 6ce. out of ‘doctest.DocTestCase’ instances, and ‘DocTestCase’ is a subclass of *note unittest.TestCase: 8ff. ‘DocTestCase’ isn’t documented here (it’s an internal detail), but studying its code can answer questions about the exact details of *note unittest: 11b. integration. Similarly, *note DocFileSuite(): 2ff1. creates a *note unittest.TestSuite: 6ce. out of ‘doctest.DocFileCase’ instances, and ‘DocFileCase’ is a subclass of ‘DocTestCase’. So both ways of creating a *note unittest.TestSuite: 6ce. run instances of ‘DocTestCase’. This is important for a subtle reason: when you run *note doctest: 67. functions yourself, you can control the *note doctest: 67. options in use directly, by passing option flags to *note doctest: 67. functions. However, if you’re writing a *note unittest: 11b. framework, *note unittest: 11b. ultimately controls when and how tests get run. The framework author typically wants to control *note doctest: 67. reporting options (perhaps, e.g., specified by command line options), but there’s no way to pass options through *note unittest: 11b. to *note doctest: 67. test runners. For this reason, *note doctest: 67. also supports a notion of *note doctest: 67. reporting flags specific to *note unittest: 11b. support, via this function: -- Function: doctest.set_unittest_reportflags (flags) Set the *note doctest: 67. reporting flags to use. Argument `flags' takes the *note bitwise OR: 11e4. of option flags. See section *note Option Flags: 83c. Only “reporting flags” can be used. This is a module-global setting, and affects all future doctests run by module *note unittest: 11b.: the ‘runTest()’ method of ‘DocTestCase’ looks at the option flags specified for the test case when the ‘DocTestCase’ instance was constructed. If no reporting flags were specified (which is the typical and expected case), *note doctest: 67.’s *note unittest: 11b. reporting flags are *note bitwise ORed: 11e4. into the option flags, and the option flags so augmented are passed to the *note DocTestRunner: 2fe3. instance created to run the doctest. If any reporting flags were specified when the ‘DocTestCase’ instance was constructed, *note doctest: 67.’s *note unittest: 11b. reporting flags are ignored. The value of the *note unittest: 11b. reporting flags in effect before the function was called is returned by the function.  File: python.info, Node: Advanced API, Next: Debugging, Prev: Unittest API, Up: doctest — Test interactive Python examples 5.26.3.13 Advanced API ...................... The basic API is a simple wrapper that’s intended to make doctest easy to use. It is fairly flexible, and should meet most users’ needs; however, if you require more fine-grained control over testing, or wish to extend doctest’s capabilities, then you should use the advanced API. The advanced API revolves around two container classes, which are used to store the interactive examples extracted from doctest cases: * *note Example: 2ff6.: A single Python *note statement: 1847, paired with its expected output. * *note DocTest: 2ff2.: A collection of *note Example: 2ff6.s, typically extracted from a single docstring or text file. Additional processing classes are defined to find, parse, and run, and check doctest examples: * *note DocTestFinder: 2fed.: Finds all docstrings in a given module, and uses a *note DocTestParser: 2fd3. to create a *note DocTest: 2ff2. from every docstring that contains interactive examples. * *note DocTestParser: 2fd3.: Creates a *note DocTest: 2ff2. object from a string (such as an object’s docstring). * *note DocTestRunner: 2fe3.: Executes the examples in a *note DocTest: 2ff2, and uses an *note OutputChecker: 2fe2. to verify their output. * *note OutputChecker: 2fe2.: Compares the actual output from a doctest example with the expected output, and decides whether they match. The relationships among these processing classes are summarized in the following diagram: list of: +------+ +---------+ |module| --DocTestFinder-> | DocTest | --DocTestRunner-> results +------+ | ^ +---------+ | ^ (printed) | | | Example | | | v | | ... | v | DocTestParser | Example | OutputChecker +---------+ * Menu: * DocTest Objects:: * Example Objects:: * DocTestFinder objects:: * DocTestParser objects:: * DocTestRunner objects:: * OutputChecker objects::  File: python.info, Node: DocTest Objects, Next: Example Objects, Up: Advanced API 5.26.3.14 DocTest Objects ......................... -- Class: doctest.DocTest (examples, globs, name, filename, lineno, docstring) A collection of doctest examples that should be run in a single namespace. The constructor arguments are used to initialize the attributes of the same names. *note DocTest: 2ff2. defines the following attributes. They are initialized by the constructor, and should not be modified directly. -- Attribute: examples A list of *note Example: 2ff6. objects encoding the individual interactive Python examples that should be run by this test. -- Attribute: globs The namespace (aka globals) that the examples should be run in. This is a dictionary mapping names to values. Any changes to the namespace made by the examples (such as binding new variables) will be reflected in *note globs: 2ffa. after the test is run. -- Attribute: name A string name identifying the *note DocTest: 2ff2. Typically, this is the name of the object or file that the test was extracted from. -- Attribute: filename The name of the file that this *note DocTest: 2ff2. was extracted from; or ‘None’ if the filename is unknown, or if the *note DocTest: 2ff2. was not extracted from a file. -- Attribute: lineno The line number within *note filename: 2ffc. where this *note DocTest: 2ff2. begins, or ‘None’ if the line number is unavailable. This line number is zero-based with respect to the beginning of the file. -- Attribute: docstring The string that the test was extracted from, or ‘None’ if the string is unavailable, or if the test was not extracted from a string.  File: python.info, Node: Example Objects, Next: DocTestFinder objects, Prev: DocTest Objects, Up: Advanced API 5.26.3.15 Example Objects ......................... -- Class: doctest.Example (source, want, exc_msg=None, lineno=0, indent=0, options=None) A single interactive example, consisting of a Python statement and its expected output. The constructor arguments are used to initialize the attributes of the same names. *note Example: 2ff6. defines the following attributes. They are initialized by the constructor, and should not be modified directly. -- Attribute: source A string containing the example’s source code. This source code consists of a single Python statement, and always ends with a newline; the constructor adds a newline when necessary. -- Attribute: want The expected output from running the example’s source code (either from stdout, or a traceback in case of exception). *note want: 3002. ends with a newline unless no output is expected, in which case it’s an empty string. The constructor adds a newline when necessary. -- Attribute: exc_msg The exception message generated by the example, if the example is expected to generate an exception; or ‘None’ if it is not expected to generate an exception. This exception message is compared against the return value of *note traceback.format_exception_only(): 3004. *note exc_msg: 3003. ends with a newline unless it’s ‘None’. The constructor adds a newline if needed. -- Attribute: lineno The line number within the string containing this example where the example begins. This line number is zero-based with respect to the beginning of the containing string. -- Attribute: indent The example’s indentation in the containing string, i.e., the number of space characters that precede the example’s first prompt. -- Attribute: options A dictionary mapping from option flags to ‘True’ or ‘False’, which is used to override default options for this example. Any option flags not contained in this dictionary are left at their default value (as specified by the *note DocTestRunner: 2fe3.’s ‘optionflags’). By default, no options are set.  File: python.info, Node: DocTestFinder objects, Next: DocTestParser objects, Prev: Example Objects, Up: Advanced API 5.26.3.16 DocTestFinder objects ............................... -- Class: doctest.DocTestFinder (verbose=False, parser=DocTestParser(), recurse=True, exclude_empty=True) A processing class used to extract the *note DocTest: 2ff2.s that are relevant to a given object, from its docstring and the docstrings of its contained objects. *note DocTest: 2ff2.s can be extracted from modules, classes, functions, methods, staticmethods, classmethods, and properties. The optional argument `verbose' can be used to display the objects searched by the finder. It defaults to ‘False’ (no output). The optional argument `parser' specifies the *note DocTestParser: 2fd3. object (or a drop-in replacement) that is used to extract doctests from docstrings. If the optional argument `recurse' is false, then *note DocTestFinder.find(): 300a. will only examine the given object, and not any contained objects. If the optional argument `exclude_empty' is false, then *note DocTestFinder.find(): 300a. will include tests for objects with empty docstrings. *note DocTestFinder: 2fed. defines the following method: -- Method: find (obj[, name][, module][, globs][, extraglobs]) Return a list of the *note DocTest: 2ff2.s that are defined by `obj'’s docstring, or by any of its contained objects’ docstrings. The optional argument `name' specifies the object’s name; this name will be used to construct names for the returned *note DocTest: 2ff2.s. If `name' is not specified, then ‘obj.__name__’ is used. The optional parameter `module' is the module that contains the given object. If the module is not specified or is ‘None’, then the test finder will attempt to automatically determine the correct module. The object’s module is used: * As a default namespace, if `globs' is not specified. * To prevent the DocTestFinder from extracting DocTests from objects that are imported from other modules. (Contained objects with modules other than `module' are ignored.) * To find the name of the file containing the object. * To help find the line number of the object within its file. If `module' is ‘False’, no attempt to find the module will be made. This is obscure, of use mostly in testing doctest itself: if `module' is ‘False’, or is ‘None’ but cannot be found automatically, then all objects are considered to belong to the (non-existent) module, so all contained objects will (recursively) be searched for doctests. The globals for each *note DocTest: 2ff2. is formed by combining `globs' and `extraglobs' (bindings in `extraglobs' override bindings in `globs'). A new shallow copy of the globals dictionary is created for each *note DocTest: 2ff2. If `globs' is not specified, then it defaults to the module’s `__dict__', if specified, or ‘{}’ otherwise. If `extraglobs' is not specified, then it defaults to ‘{}’.  File: python.info, Node: DocTestParser objects, Next: DocTestRunner objects, Prev: DocTestFinder objects, Up: Advanced API 5.26.3.17 DocTestParser objects ............................... -- Class: doctest.DocTestParser A processing class used to extract interactive examples from a string, and use them to create a *note DocTest: 2ff2. object. *note DocTestParser: 2fd3. defines the following methods: -- Method: get_doctest (string, globs, name, filename, lineno) Extract all doctest examples from the given string, and collect them into a *note DocTest: 2ff2. object. `globs', `name', `filename', and `lineno' are attributes for the new *note DocTest: 2ff2. object. See the documentation for *note DocTest: 2ff2. for more information. -- Method: get_examples (string, name='<string>') Extract all doctest examples from the given string, and return them as a list of *note Example: 2ff6. objects. Line numbers are 0-based. The optional argument `name' is a name identifying this string, and is only used for error messages. -- Method: parse (string, name='<string>') Divide the given string into examples and intervening text, and return them as a list of alternating *note Example: 2ff6.s and strings. Line numbers for the *note Example: 2ff6.s are 0-based. The optional argument `name' is a name identifying this string, and is only used for error messages.  File: python.info, Node: DocTestRunner objects, Next: OutputChecker objects, Prev: DocTestParser objects, Up: Advanced API 5.26.3.18 DocTestRunner objects ............................... -- Class: doctest.DocTestRunner (checker=None, verbose=None, optionflags=0) A processing class used to execute and verify the interactive examples in a *note DocTest: 2ff2. The comparison between expected outputs and actual outputs is done by an *note OutputChecker: 2fe2. This comparison may be customized with a number of option flags; see section *note Option Flags: 83c. for more information. If the option flags are insufficient, then the comparison may also be customized by passing a subclass of *note OutputChecker: 2fe2. to the constructor. The test runner’s display output can be controlled in two ways. First, an output function can be passed to ‘TestRunner.run()’; this function will be called with strings that should be displayed. It defaults to ‘sys.stdout.write’. If capturing the output is not sufficient, then the display output can be also customized by subclassing DocTestRunner, and overriding the methods *note report_start(): 3012, *note report_success(): 3013, *note report_unexpected_exception(): 3014, and *note report_failure(): 3015. The optional keyword argument `checker' specifies the *note OutputChecker: 2fe2. object (or drop-in replacement) that should be used to compare the expected outputs to the actual outputs of doctest examples. The optional keyword argument `verbose' controls the *note DocTestRunner: 2fe3.’s verbosity. If `verbose' is ‘True’, then information is printed about each example, as it is run. If `verbose' is ‘False’, then only failures are printed. If `verbose' is unspecified, or ‘None’, then verbose output is used iff the command-line switch ‘-v’ is used. The optional keyword argument `optionflags' can be used to control how the test runner compares expected output to actual output, and how it displays failures. For more information, see section *note Option Flags: 83c. *note DocTestParser: 2fd3. defines the following methods: -- Method: report_start (out, test, example) Report that the test runner is about to process the given example. This method is provided to allow subclasses of *note DocTestRunner: 2fe3. to customize their output; it should not be called directly. `example' is the example about to be processed. `test' is the test `containing example'. `out' is the output function that was passed to *note DocTestRunner.run(): 3016. -- Method: report_success (out, test, example, got) Report that the given example ran successfully. This method is provided to allow subclasses of *note DocTestRunner: 2fe3. to customize their output; it should not be called directly. `example' is the example about to be processed. `got' is the actual output from the example. `test' is the test containing `example'. `out' is the output function that was passed to *note DocTestRunner.run(): 3016. -- Method: report_failure (out, test, example, got) Report that the given example failed. This method is provided to allow subclasses of *note DocTestRunner: 2fe3. to customize their output; it should not be called directly. `example' is the example about to be processed. `got' is the actual output from the example. `test' is the test containing `example'. `out' is the output function that was passed to *note DocTestRunner.run(): 3016. -- Method: report_unexpected_exception (out, test, example, exc_info) Report that the given example raised an unexpected exception. This method is provided to allow subclasses of *note DocTestRunner: 2fe3. to customize their output; it should not be called directly. `example' is the example about to be processed. `exc_info' is a tuple containing information about the unexpected exception (as returned by *note sys.exc_info(): c5f.). `test' is the test containing `example'. `out' is the output function that was passed to *note DocTestRunner.run(): 3016. -- Method: run (test, compileflags=None, out=None, clear_globs=True) Run the examples in `test' (a *note DocTest: 2ff2. object), and display the results using the writer function `out'. The examples are run in the namespace ‘test.globs’. If `clear_globs' is true (the default), then this namespace will be cleared after the test runs, to help with garbage collection. If you would like to examine the namespace after the test completes, then use `clear_globs=False'. `compileflags' gives the set of flags that should be used by the Python compiler when running the examples. If not specified, then it will default to the set of future-import flags that apply to `globs'. The output of each example is checked using the *note DocTestRunner: 2fe3.’s output checker, and the results are formatted by the ‘DocTestRunner.report_*()’ methods. -- Method: summarize (verbose=None) Print a summary of all the test cases that have been run by this DocTestRunner, and return a *note named tuple: aa3. ‘TestResults(failed, attempted)’. The optional `verbose' argument controls how detailed the summary is. If the verbosity is not specified, then the *note DocTestRunner: 2fe3.’s verbosity is used.  File: python.info, Node: OutputChecker objects, Prev: DocTestRunner objects, Up: Advanced API 5.26.3.19 OutputChecker objects ............................... -- Class: doctest.OutputChecker A class used to check the whether the actual output from a doctest example matches the expected output. *note OutputChecker: 2fe2. defines two methods: *note check_output(): 301a, which compares a given pair of outputs, and returns ‘True’ if they match; and *note output_difference(): 301b, which returns a string describing the differences between two outputs. *note OutputChecker: 2fe2. defines the following methods: -- Method: check_output (want, got, optionflags) Return ‘True’ iff the actual output from an example (`got') matches the expected output (`want'). These strings are always considered to match if they are identical; but depending on what option flags the test runner is using, several non-exact match types are also possible. See section *note Option Flags: 83c. for more information about option flags. -- Method: output_difference (example, got, optionflags) Return a string describing the differences between the expected output for a given example (`example') and the actual output (`got'). `optionflags' is the set of option flags used to compare `want' and `got'.  File: python.info, Node: Debugging, Next: Soapbox, Prev: Advanced API, Up: doctest — Test interactive Python examples 5.26.3.20 Debugging ................... Doctest provides several mechanisms for debugging doctest examples: * Several functions convert doctests to executable Python programs, which can be run under the Python debugger, *note pdb: c9. * The *note DebugRunner: 301e. class is a subclass of *note DocTestRunner: 2fe3. that raises an exception for the first failing example, containing information about that example. This information can be used to perform post-mortem debugging on the example. * The *note unittest: 11b. cases generated by *note DocTestSuite(): 6cd. support the *note debug(): 301f. method defined by *note unittest.TestCase: 8ff. * You can add a call to *note pdb.set_trace(): 3c2. in a doctest example, and you’ll drop into the Python debugger when that line is executed. Then you can inspect current values of variables, and so on. For example, suppose ‘a.py’ contains just this module docstring: """ >>> def f(x): ... g(x*2) >>> def g(x): ... print(x+3) ... import pdb; pdb.set_trace() >>> f(3) 9 """ Then an interactive Python session may look like this: >>> import a, doctest >>> doctest.testmod(a) --Return-- > <doctest a[1]>(3)g()->None -> import pdb; pdb.set_trace() (Pdb) list 1 def g(x): 2 print(x+3) 3 -> import pdb; pdb.set_trace() [EOF] (Pdb) p x 6 (Pdb) step --Return-- > <doctest a[0]>(2)f()->None -> g(x*2) (Pdb) list 1 def f(x): 2 -> g(x*2) [EOF] (Pdb) p x 3 (Pdb) step --Return-- > <doctest a[2]>(1)?()->None -> f(3) (Pdb) cont (0, 3) >>> Functions that convert doctests to Python code, and possibly run the synthesized code under the debugger: -- Function: doctest.script_from_examples (s) Convert text with examples to a script. Argument `s' is a string containing doctest examples. The string is converted to a Python script, where doctest examples in `s' are converted to regular code, and everything else is converted to Python comments. The generated script is returned as a string. For example, import doctest print(doctest.script_from_examples(r""" Set x and y to 1 and 2. >>> x, y = 1, 2 Print their sum: >>> print(x+y) 3 """)) displays: # Set x and y to 1 and 2. x, y = 1, 2 # # Print their sum: print(x+y) # Expected: ## 3 This function is used internally by other functions (see below), but can also be useful when you want to transform an interactive Python session into a Python script. -- Function: doctest.testsource (module, name) Convert the doctest for an object to a script. Argument `module' is a module object, or dotted name of a module, containing the object whose doctests are of interest. Argument `name' is the name (within the module) of the object with the doctests of interest. The result is a string, containing the object’s docstring converted to a Python script, as described for *note script_from_examples(): 3020. above. For example, if module ‘a.py’ contains a top-level function ‘f()’, then import a, doctest print(doctest.testsource(a, "a.f")) prints a script version of function ‘f()’’s docstring, with doctests converted to code, and the rest placed in comments. -- Function: doctest.debug (module, name, pm=False) Debug the doctests for an object. The `module' and `name' arguments are the same as for function *note testsource(): 3021. above. The synthesized Python script for the named object’s docstring is written to a temporary file, and then that file is run under the control of the Python debugger, *note pdb: c9. A shallow copy of ‘module.__dict__’ is used for both local and global execution context. Optional argument `pm' controls whether post-mortem debugging is used. If `pm' has a true value, the script file is run directly, and the debugger gets involved only if the script terminates via raising an unhandled exception. If it does, then post-mortem debugging is invoked, via *note pdb.post_mortem(): d45, passing the traceback object from the unhandled exception. If `pm' is not specified, or is false, the script is run under the debugger from the start, via passing an appropriate *note exec(): c44. call to *note pdb.run(): 3022. -- Function: doctest.debug_src (src, pm=False, globs=None) Debug the doctests in a string. This is like function *note debug(): 301f. above, except that a string containing doctest examples is specified directly, via the `src' argument. Optional argument `pm' has the same meaning as in function *note debug(): 301f. above. Optional argument `globs' gives a dictionary to use as both local and global execution context. If not specified, or ‘None’, an empty dictionary is used. If specified, a shallow copy of the dictionary is used. The *note DebugRunner: 301e. class, and the special exceptions it may raise, are of most interest to testing framework authors, and will only be sketched here. See the source code, and especially *note DebugRunner: 301e.’s docstring (which is a doctest!) for more details: -- Class: doctest.DebugRunner (checker=None, verbose=None, optionflags=0) A subclass of *note DocTestRunner: 2fe3. that raises an exception as soon as a failure is encountered. If an unexpected exception occurs, an *note UnexpectedException: 3024. exception is raised, containing the test, the example, and the original exception. If the output doesn’t match, then a *note DocTestFailure: 3025. exception is raised, containing the test, the example, and the actual output. For information about the constructor parameters and methods, see the documentation for *note DocTestRunner: 2fe3. in section *note Advanced API: 2ff5. There are two exceptions that may be raised by *note DebugRunner: 301e. instances: -- Exception: doctest.DocTestFailure (test, example, got) An exception raised by *note DocTestRunner: 2fe3. to signal that a doctest example’s actual output did not match its expected output. The constructor arguments are used to initialize the attributes of the same names. *note DocTestFailure: 3025. defines the following attributes: -- Attribute: DocTestFailure.test The *note DocTest: 2ff2. object that was being run when the example failed. -- Attribute: DocTestFailure.example The *note Example: 2ff6. that failed. -- Attribute: DocTestFailure.got The example’s actual output. -- Exception: doctest.UnexpectedException (test, example, exc_info) An exception raised by *note DocTestRunner: 2fe3. to signal that a doctest example raised an unexpected exception. The constructor arguments are used to initialize the attributes of the same names. *note UnexpectedException: 3024. defines the following attributes: -- Attribute: UnexpectedException.test The *note DocTest: 2ff2. object that was being run when the example failed. -- Attribute: UnexpectedException.example The *note Example: 2ff6. that failed. -- Attribute: UnexpectedException.exc_info A tuple containing information about the unexpected exception, as returned by *note sys.exc_info(): c5f.  File: python.info, Node: Soapbox, Prev: Debugging, Up: doctest — Test interactive Python examples 5.26.3.21 Soapbox ................. As mentioned in the introduction, *note doctest: 67. has grown to have three primary uses: 1. Checking examples in docstrings. 2. Regression testing. 3. Executable documentation / literate testing. These uses have different requirements, and it is important to distinguish them. In particular, filling your docstrings with obscure test cases makes for bad documentation. When writing a docstring, choose docstring examples with care. There’s an art to this that needs to be learned—it may not be natural at first. Examples should add genuine value to the documentation. A good example can often be worth many words. If done with care, the examples will be invaluable for your users, and will pay back the time it takes to collect them many times over as the years go by and things change. I’m still amazed at how often one of my *note doctest: 67. examples stops working after a “harmless” change. Doctest also makes an excellent tool for regression testing, especially if you don’t skimp on explanatory text. By interleaving prose and examples, it becomes much easier to keep track of what’s actually being tested, and why. When a test fails, good prose can make it much easier to figure out what the problem is, and how it should be fixed. It’s true that you could write extensive comments in code-based testing, but few programmers do. Many have found that using doctest approaches instead leads to much clearer tests. Perhaps this is simply because doctest makes writing prose a little easier than writing code, while writing comments in code is a little harder. I think it goes deeper than just that: the natural attitude when writing a doctest-based test is that you want to explain the fine points of your software, and illustrate them with examples. This in turn naturally leads to test files that start with the simplest features, and logically progress to complications and edge cases. A coherent narrative is the result, instead of a collection of isolated functions that test isolated bits of functionality seemingly at random. It’s a different attitude, and produces different results, blurring the distinction between testing and explaining. Regression testing is best confined to dedicated objects or files. There are several options for organizing tests: * Write text files containing test cases as interactive examples, and test the files using *note testfile(): 2fca. or *note DocFileSuite(): 2ff1. This is recommended, although is easiest to do for new projects, designed from the start to use doctest. * Define functions named ‘_regrtest_topic’ that consist of single docstrings, containing test cases for the named topics. These functions can be included in the same file as the module, or separated out into a separate test file. * Define a ‘__test__’ dictionary mapping from regression test topics to docstrings containing test cases. When you have placed your tests in a module, the module can itself be the test runner. When a test fails, you can arrange for your test runner to re-run only the failing doctest while you debug the problem. Here is a minimal example of such a test runner: if __name__ == '__main__': import doctest flags = doctest.REPORT_NDIFF|doctest.FAIL_FAST if len(sys.argv) > 1: name = sys.argv[1] if name in globals(): obj = globals()[name] else: obj = __test__[name] doctest.run_docstring_examples(obj, globals(), name=name, optionflags=flags) else: fail, total = doctest.testmod(optionflags=flags) print("{} failures out of {} tests".format(fail, total))  File: python.info, Node: unittest — Unit testing framework, Next: unittest mock — mock object library, Prev: doctest — Test interactive Python examples, Up: Development Tools 5.26.4 ‘unittest’ — Unit testing framework ------------------------------------------ `Source code:' Lib/unittest/__init__.py(1) __________________________________________________________________ (If you are already familiar with the basic concepts of testing, you might want to skip to *note the list of assert methods: 3030.) The *note unittest: 11b. unit testing framework was originally inspired by JUnit and has a similar flavor as major unit testing frameworks in other languages. It supports test automation, sharing of setup and shutdown code for tests, aggregation of tests into collections, and independence of the tests from the reporting framework. To achieve this, *note unittest: 11b. supports some important concepts in an object-oriented way: test fixture A `test fixture' represents the preparation needed to perform one or more tests, and any associated cleanup actions. This may involve, for example, creating temporary or proxy databases, directories, or starting a server process. test case A `test case' is the individual unit of testing. It checks for a specific response to a particular set of inputs. *note unittest: 11b. provides a base class, *note TestCase: 8ff, which may be used to create new test cases. test suite A `test suite' is a collection of test cases, test suites, or both. It is used to aggregate tests that should be executed together. test runner A `test runner' is a component which orchestrates the execution of tests and provides the outcome to the user. The runner may use a graphical interface, a textual interface, or return a special value to indicate the results of executing the tests. See also ........ Module *note doctest: 67. Another test-support module with a very different flavor. Simple Smalltalk Testing: With Patterns(2) Kent Beck’s original paper on testing frameworks using the pattern shared by *note unittest: 11b. pytest(3) Third-party unittest framework with a lighter-weight syntax for writing tests. For example, ‘assert func(10) == 42’. The Python Testing Tools Taxonomy(4) An extensive list of Python testing tools including functional testing frameworks and mock object libraries. Testing in Python Mailing List(5) A special-interest-group for discussion of testing, and testing tools, in Python. The script ‘Tools/unittestgui/unittestgui.py’ in the Python source distribution is a GUI tool for test discovery and execution. This is intended largely for ease of use for those new to unit testing. For production environments it is recommended that tests be driven by a continuous integration system such as Buildbot(6), Jenkins(7) or Travis-CI(8), or AppVeyor(9). * Menu: * Basic example:: * Command-Line Interface: Command-Line Interface<3>. * Test Discovery:: * Organizing test code:: * Re-using old test code:: * Skipping tests and expected failures:: * Distinguishing test iterations using subtests:: * Classes and functions:: * Class and Module Fixtures:: * Signal Handling:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/unittest/__init__.py (2) https://web.archive.org/web/20150315073817/http://www.xprogramming.com/testfram.htm (3) https://docs.pytest.org/ (4) https://wiki.python.org/moin/PythonTestingToolsTaxonomy (5) http://lists.idyll.org/listinfo/testing-in-python (6) https://buildbot.net/ (7) https://jenkins.io/ (8) https://travis-ci.com (9) https://www.appveyor.com/  File: python.info, Node: Basic example, Next: Command-Line Interface<3>, Up: unittest — Unit testing framework 5.26.4.1 Basic example ...................... The *note unittest: 11b. module provides a rich set of tools for constructing and running tests. This section demonstrates that a small subset of the tools suffice to meet the needs of most users. Here is a short script to test three string methods: import unittest class TestStringMethods(unittest.TestCase): def test_upper(self): self.assertEqual('foo'.upper(), 'FOO') def test_isupper(self): self.assertTrue('FOO'.isupper()) self.assertFalse('Foo'.isupper()) def test_split(self): s = 'hello world' self.assertEqual(s.split(), ['hello', 'world']) # check that s.split fails when the separator is not a string with self.assertRaises(TypeError): s.split(2) if __name__ == '__main__': unittest.main() A testcase is created by subclassing *note unittest.TestCase: 8ff. The three individual tests are defined with methods whose names start with the letters ‘test’. This naming convention informs the test runner about which methods represent tests. The crux of each test is a call to *note assertEqual(): bb5. to check for an expected result; *note assertTrue(): bb4. or *note assertFalse(): cc7. to verify a condition; or *note assertRaises(): aba. to verify that a specific exception gets raised. These methods are used instead of the *note assert: e06. statement so the test runner can accumulate all test results and produce a report. The *note setUp(): ccb. and *note tearDown(): ccc. methods allow you to define instructions that will be executed before and after each test method. They are covered in more detail in the section *note Organizing test code: 3033. The final block shows a simple way to run the tests. *note unittest.main(): 902. provides a command-line interface to the test script. When run from the command line, the above script produces an output that looks like this: ... ---------------------------------------------------------------------- Ran 3 tests in 0.000s OK Passing the ‘-v’ option to your test script will instruct *note unittest.main(): 902. to enable a higher level of verbosity, and produce the following output: test_isupper (__main__.TestStringMethods) ... ok test_split (__main__.TestStringMethods) ... ok test_upper (__main__.TestStringMethods) ... ok ---------------------------------------------------------------------- Ran 3 tests in 0.001s OK The above examples show the most commonly used *note unittest: 11b. features which are sufficient to meet many everyday testing needs. The remainder of the documentation explores the full feature set from first principles.  File: python.info, Node: Command-Line Interface<3>, Next: Test Discovery, Prev: Basic example, Up: unittest — Unit testing framework 5.26.4.2 Command-Line Interface ............................... The unittest module can be used from the command line to run tests from modules, classes or even individual test methods: python -m unittest test_module1 test_module2 python -m unittest test_module.TestClass python -m unittest test_module.TestClass.test_method You can pass in a list with any combination of module names, and fully qualified class or method names. Test modules can be specified by file path as well: python -m unittest tests/test_something.py This allows you to use the shell filename completion to specify the test module. The file specified must still be importable as a module. The path is converted to a module name by removing the ‘.py’ and converting path separators into ‘.’. If you want to execute a test file that isn’t importable as a module you should execute the file directly instead. You can run tests with more detail (higher verbosity) by passing in the -v flag: python -m unittest -v test_module When executed without arguments *note Test Discovery: 3036. is started: python -m unittest For a list of all the command-line options: python -m unittest -h Changed in version 3.2: In earlier versions it was only possible to run individual test methods and not modules or classes. * Menu: * Command-line options: Command-line options<3>.  File: python.info, Node: Command-line options<3>, Up: Command-Line Interface<3> 5.26.4.3 Command-line options ............................. ‘unittest’ supports these command-line options: -- Program Option: -b, --buffer The standard output and standard error streams are buffered during the test run. Output during a passing test is discarded. Output is echoed normally on test fail or error and is added to the failure messages. -- Program Option: -c, --catch ‘Control-C’ during the test run waits for the current test to end and then reports all the results so far. A second ‘Control-C’ raises the normal *note KeyboardInterrupt: 197. exception. See *note Signal Handling: 3038. for the functions that provide this functionality. -- Program Option: -f, --failfast Stop the test run on the first error or failure. -- Program Option: -k Only run test methods and classes that match the pattern or substring. This option may be used multiple times, in which case all test cases that match of the given patterns are included. Patterns that contain a wildcard character (‘*’) are matched against the test name using *note fnmatch.fnmatchcase(): 193b.; otherwise simple case-sensitive substring matching is used. Patterns are matched against the fully qualified test method name as imported by the test loader. For example, ‘-k foo’ matches ‘foo_tests.SomeTest.test_something’, ‘bar_tests.SomeTest.test_foo’, but not ‘bar_tests.FooTest.test_something’. -- Program Option: --locals Show local variables in tracebacks. New in version 3.2: The command-line options ‘-b’, ‘-c’ and ‘-f’ were added. New in version 3.5: The command-line option ‘--locals’. New in version 3.7: The command-line option ‘-k’. The command line can also be used for test discovery, for running all of the tests in a project or just a subset.  File: python.info, Node: Test Discovery, Next: Organizing test code, Prev: Command-Line Interface<3>, Up: unittest — Unit testing framework 5.26.4.4 Test Discovery ....................... New in version 3.2. Unittest supports simple test discovery. In order to be compatible with test discovery, all of the test files must be *note modules: f11. or *note packages: f1e. (including *note namespace packages: 1158.) importable from the top-level directory of the project (this means that their filenames must be valid *note identifiers: 1071.). Test discovery is implemented in *note TestLoader.discover(): 904, but can also be used from the command line. The basic command-line usage is: cd project_directory python -m unittest discover Note: As a shortcut, ‘python -m unittest’ is the equivalent of ‘python -m unittest discover’. If you want to pass arguments to test discovery the ‘discover’ sub-command must be used explicitly. The ‘discover’ sub-command has the following options: -- Program Option: -v, --verbose Verbose output -- Program Option: -s, --start-directory directory Directory to start discovery (‘.’ default) -- Program Option: -p, --pattern pattern Pattern to match test files (‘test*.py’ default) -- Program Option: -t, --top-level-directory directory Top level directory of project (defaults to start directory) The *note -s: 303d, *note -p: 303e, and *note -t: 303f. options can be passed in as positional arguments in that order. The following two command lines are equivalent: python -m unittest discover -s project_directory -p "*_test.py" python -m unittest discover project_directory "*_test.py" As well as being a path it is possible to pass a package name, for example ‘myproject.subpackage.test’, as the start directory. The package name you supply will then be imported and its location on the filesystem will be used as the start directory. Caution: Test discovery loads tests by importing them. Once test discovery has found all the test files from the start directory you specify it turns the paths into package names to import. For example ‘foo/bar/baz.py’ will be imported as ‘foo.bar.baz’. If you have a package installed globally and attempt test discovery on a different copy of the package then the import `could' happen from the wrong place. If this happens test discovery will warn you and exit. If you supply the start directory as a package name rather than a path to a directory then discover assumes that whichever location it imports from is the location you intended, so you will not get the warning. Test modules and packages can customize test loading and discovery by through the *note load_tests protocol: 3040. Changed in version 3.4: Test discovery supports *note namespace packages: 1158. for start directory. Note that you need to the top level directory too. (e.g. ‘python -m unittest discover -s root/namespace -t root’).  File: python.info, Node: Organizing test code, Next: Re-using old test code, Prev: Test Discovery, Up: unittest — Unit testing framework 5.26.4.5 Organizing test code ............................. The basic building blocks of unit testing are `test cases' — single scenarios that must be set up and checked for correctness. In *note unittest: 11b, test cases are represented by *note unittest.TestCase: 8ff. instances. To make your own test cases you must write subclasses of *note TestCase: 8ff. or use *note FunctionTestCase: 3042. The testing code of a *note TestCase: 8ff. instance should be entirely self contained, such that it can be run either in isolation or in arbitrary combination with any number of other test cases. The simplest *note TestCase: 8ff. subclass will simply implement a test method (i.e. a method whose name starts with ‘test’) in order to perform specific testing code: import unittest class DefaultWidgetSizeTestCase(unittest.TestCase): def test_default_widget_size(self): widget = Widget('The widget') self.assertEqual(widget.size(), (50, 50)) Note that in order to test something, we use one of the ‘assert*()’ methods provided by the *note TestCase: 8ff. base class. If the test fails, an exception will be raised with an explanatory message, and *note unittest: 11b. will identify the test case as a `failure'. Any other exceptions will be treated as `errors'. Tests can be numerous, and their set-up can be repetitive. Luckily, we can factor out set-up code by implementing a method called *note setUp(): ccb, which the testing framework will automatically call for every single test we run: import unittest class WidgetTestCase(unittest.TestCase): def setUp(self): self.widget = Widget('The widget') def test_default_widget_size(self): self.assertEqual(self.widget.size(), (50,50), 'incorrect default size') def test_widget_resize(self): self.widget.resize(100,150) self.assertEqual(self.widget.size(), (100,150), 'wrong size after resize') Note: The order in which the various tests will be run is determined by sorting the test method names with respect to the built-in ordering for strings. If the *note setUp(): ccb. method raises an exception while the test is running, the framework will consider the test to have suffered an error, and the test method will not be executed. Similarly, we can provide a *note tearDown(): ccc. method that tidies up after the test method has been run: import unittest class WidgetTestCase(unittest.TestCase): def setUp(self): self.widget = Widget('The widget') def tearDown(self): self.widget.dispose() If *note setUp(): ccb. succeeded, *note tearDown(): ccc. will be run whether the test method succeeded or not. Such a working environment for the testing code is called a `test fixture'. A new TestCase instance is created as a unique test fixture used to execute each individual test method. Thus *note setUp(): ccb, *note tearDown(): ccc, and ‘__init__()’ will be called once per test. It is recommended that you use TestCase implementations to group tests together according to the features they test. *note unittest: 11b. provides a mechanism for this: the `test suite', represented by *note unittest: 11b.’s *note TestSuite: 6ce. class. In most cases, calling *note unittest.main(): 902. will do the right thing and collect all the module’s test cases for you and execute them. However, should you want to customize the building of your test suite, you can do it yourself: def suite(): suite = unittest.TestSuite() suite.addTest(WidgetTestCase('test_default_widget_size')) suite.addTest(WidgetTestCase('test_widget_resize')) return suite if __name__ == '__main__': runner = unittest.TextTestRunner() runner.run(suite()) You can place the definitions of test cases and test suites in the same modules as the code they are to test (such as ‘widget.py’), but there are several advantages to placing the test code in a separate module, such as ‘test_widget.py’: * The test module can be run standalone from the command line. * The test code can more easily be separated from shipped code. * There is less temptation to change test code to fit the code it tests without a good reason. * Test code should be modified much less frequently than the code it tests. * Tested code can be refactored more easily. * Tests for modules written in C must be in separate modules anyway, so why not be consistent? * If the testing strategy changes, there is no need to change the source code.  File: python.info, Node: Re-using old test code, Next: Skipping tests and expected failures, Prev: Organizing test code, Up: unittest — Unit testing framework 5.26.4.6 Re-using old test code ............................... Some users will find that they have existing test code that they would like to run from *note unittest: 11b, without converting every old test function to a *note TestCase: 8ff. subclass. For this reason, *note unittest: 11b. provides a *note FunctionTestCase: 3042. class. This subclass of *note TestCase: 8ff. can be used to wrap an existing test function. Set-up and tear-down functions can also be provided. Given the following test function: def testSomething(): something = makeSomething() assert something.name is not None # ... one can create an equivalent test case instance as follows, with optional set-up and tear-down methods: testcase = unittest.FunctionTestCase(testSomething, setUp=makeSomethingDB, tearDown=deleteSomethingDB) Note: Even though *note FunctionTestCase: 3042. can be used to quickly convert an existing test base over to a *note unittest: 11b.-based system, this approach is not recommended. Taking the time to set up proper *note TestCase: 8ff. subclasses will make future test refactorings infinitely easier. In some cases, the existing tests may have been written using the *note doctest: 67. module. If so, *note doctest: 67. provides a ‘DocTestSuite’ class that can automatically build *note unittest.TestSuite: 6ce. instances from the existing *note doctest: 67.-based tests.  File: python.info, Node: Skipping tests and expected failures, Next: Distinguishing test iterations using subtests, Prev: Re-using old test code, Up: unittest — Unit testing framework 5.26.4.7 Skipping tests and expected failures ............................................. New in version 3.1. Unittest supports skipping individual test methods and even whole classes of tests. In addition, it supports marking a test as an “expected failure,” a test that is broken and will fail, but shouldn’t be counted as a failure on a *note TestResult: abf. Skipping a test is simply a matter of using the *note skip(): 3047. *note decorator: 283. or one of its conditional variants, calling *note TestCase.skipTest(): 3048. within a *note setUp(): ccb. or test method, or raising *note SkipTest: 903. directly. Basic skipping looks like this: class MyTestCase(unittest.TestCase): @unittest.skip("demonstrating skipping") def test_nothing(self): self.fail("shouldn't happen") @unittest.skipIf(mylib.__version__ < (1, 3), "not supported in this library version") def test_format(self): # Tests that work for only a certain version of the library. pass @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows") def test_windows_support(self): # windows specific testing code pass def test_maybe_skipped(self): if not external_resource_available(): self.skipTest("external resource not available") # test code that depends on the external resource pass This is the output of running the example above in verbose mode: test_format (__main__.MyTestCase) ... skipped 'not supported in this library version' test_nothing (__main__.MyTestCase) ... skipped 'demonstrating skipping' test_maybe_skipped (__main__.MyTestCase) ... skipped 'external resource not available' test_windows_support (__main__.MyTestCase) ... skipped 'requires Windows' ---------------------------------------------------------------------- Ran 4 tests in 0.005s OK (skipped=4) Classes can be skipped just like methods: @unittest.skip("showing class skipping") class MySkippedTestCase(unittest.TestCase): def test_not_run(self): pass *note TestCase.setUp(): ccb. can also skip the test. This is useful when a resource that needs to be set up is not available. Expected failures use the *note expectedFailure(): 3049. decorator. class ExpectedFailureTestCase(unittest.TestCase): @unittest.expectedFailure def test_fail(self): self.assertEqual(1, 0, "broken") It’s easy to roll your own skipping decorators by making a decorator that calls *note skip(): 3047. on the test when it wants it to be skipped. This decorator skips the test unless the passed object has a certain attribute: def skipUnlessHasattr(obj, attr): if hasattr(obj, attr): return lambda func: func return unittest.skip("{!r} doesn't have {!r}".format(obj, attr)) The following decorators and exception implement test skipping and expected failures: -- Function: @unittest.skip (reason) Unconditionally skip the decorated test. `reason' should describe why the test is being skipped. -- Function: @unittest.skipIf (condition, reason) Skip the decorated test if `condition' is true. -- Function: @unittest.skipUnless (condition, reason) Skip the decorated test unless `condition' is true. -- Function: @unittest.expectedFailure Mark the test as an expected failure or error. If the test fails or errors it will be considered a success. If the test passes, it will be considered a failure. -- Exception: unittest.SkipTest (reason) This exception is raised to skip a test. Usually you can use *note TestCase.skipTest(): 3048. or one of the skipping decorators instead of raising this directly. Skipped tests will not have *note setUp(): ccb. or *note tearDown(): ccc. run around them. Skipped classes will not have *note setUpClass(): 24c. or *note tearDownClass(): cc9. run. Skipped modules will not have ‘setUpModule()’ or ‘tearDownModule()’ run.  File: python.info, Node: Distinguishing test iterations using subtests, Next: Classes and functions, Prev: Skipping tests and expected failures, Up: unittest — Unit testing framework 5.26.4.8 Distinguishing test iterations using subtests ...................................................... New in version 3.4. When there are very small differences among your tests, for instance some parameters, unittest allows you to distinguish them inside the body of a test method using the *note subTest(): 900. context manager. For example, the following test: class NumbersTest(unittest.TestCase): def test_even(self): """ Test that numbers between 0 and 5 are all even. """ for i in range(0, 6): with self.subTest(i=i): self.assertEqual(i % 2, 0) will produce the following output: ====================================================================== FAIL: test_even (__main__.NumbersTest) (i=1) ---------------------------------------------------------------------- Traceback (most recent call last): File "subtests.py", line 32, in test_even self.assertEqual(i % 2, 0) AssertionError: 1 != 0 ====================================================================== FAIL: test_even (__main__.NumbersTest) (i=3) ---------------------------------------------------------------------- Traceback (most recent call last): File "subtests.py", line 32, in test_even self.assertEqual(i % 2, 0) AssertionError: 1 != 0 ====================================================================== FAIL: test_even (__main__.NumbersTest) (i=5) ---------------------------------------------------------------------- Traceback (most recent call last): File "subtests.py", line 32, in test_even self.assertEqual(i % 2, 0) AssertionError: 1 != 0 Without using a subtest, execution would stop after the first failure, and the error would be less easy to diagnose because the value of ‘i’ wouldn’t be displayed: ====================================================================== FAIL: test_even (__main__.NumbersTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "subtests.py", line 32, in test_even self.assertEqual(i % 2, 0) AssertionError: 1 != 0  File: python.info, Node: Classes and functions, Next: Class and Module Fixtures, Prev: Distinguishing test iterations using subtests, Up: unittest — Unit testing framework 5.26.4.9 Classes and functions .............................. This section describes in depth the API of *note unittest: 11b. * Menu: * Test cases:: * Grouping tests:: * Loading and running tests::  File: python.info, Node: Test cases, Next: Grouping tests, Up: Classes and functions 5.26.4.10 Test cases .................... -- Class: unittest.TestCase (methodName='runTest') Instances of the *note TestCase: 8ff. class represent the logical test units in the *note unittest: 11b. universe. This class is intended to be used as a base class, with specific tests being implemented by concrete subclasses. This class implements the interface needed by the test runner to allow it to drive the tests, and methods that the test code can use to check for and report various kinds of failure. Each instance of *note TestCase: 8ff. will run a single base method: the method named `methodName'. In most uses of *note TestCase: 8ff, you will neither change the `methodName' nor reimplement the default ‘runTest()’ method. Changed in version 3.2: *note TestCase: 8ff. can be instantiated successfully without providing a `methodName'. This makes it easier to experiment with *note TestCase: 8ff. from the interactive interpreter. *note TestCase: 8ff. instances provide three groups of methods: one group used to run the test, another used by the test implementation to check conditions and report failures, and some inquiry methods allowing information about the test itself to be gathered. Methods in the first group (running the test) are: -- Method: setUp () Method called to prepare the test fixture. This is called immediately before calling the test method; other than *note AssertionError: 1223. or *note SkipTest: 903, any exception raised by this method will be considered an error rather than a test failure. The default implementation does nothing. -- Method: tearDown () Method called immediately after the test method has been called and the result recorded. This is called even if the test method raised an exception, so the implementation in subclasses may need to be particularly careful about checking internal state. Any exception, other than *note AssertionError: 1223. or *note SkipTest: 903, raised by this method will be considered an additional error rather than a test failure (thus increasing the total number of reported errors). This method will only be called if the *note setUp(): ccb. succeeds, regardless of the outcome of the test method. The default implementation does nothing. -- Method: setUpClass () A class method called before tests in an individual class are run. ‘setUpClass’ is called with the class as the only argument and must be decorated as a *note classmethod(): 1d8.: @classmethod def setUpClass(cls): ... See *note Class and Module Fixtures: 3051. for more details. New in version 3.2. -- Method: tearDownClass () A class method called after tests in an individual class have run. ‘tearDownClass’ is called with the class as the only argument and must be decorated as a *note classmethod(): 1d8.: @classmethod def tearDownClass(cls): ... See *note Class and Module Fixtures: 3051. for more details. New in version 3.2. -- Method: run (result=None) Run the test, collecting the result into the *note TestResult: abf. object passed as `result'. If `result' is omitted or ‘None’, a temporary result object is created (by calling the *note defaultTestResult(): 3052. method) and used. The result object is returned to *note run(): abe.’s caller. The same effect may be had by simply calling the *note TestCase: 8ff. instance. Changed in version 3.3: Previous versions of ‘run’ did not return the result. Neither did calling an instance. -- Method: skipTest (reason) Calling this during a test method or *note setUp(): ccb. skips the current test. See *note Skipping tests and expected failures: 3046. for more information. New in version 3.1. -- Method: subTest (msg=None, **params) Return a context manager which executes the enclosed code block as a subtest. `msg' and `params' are optional, arbitrary values which are displayed whenever a subtest fails, allowing you to identify them clearly. A test case can contain any number of subtest declarations, and they can be arbitrarily nested. See *note Distinguishing test iterations using subtests: 901. for more information. New in version 3.4. -- Method: debug () Run the test without collecting the result. This allows exceptions raised by the test to be propagated to the caller, and can be used to support running tests under a debugger. The *note TestCase: 8ff. class provides several assert methods to check for and report failures. The following table lists the most commonly used methods (see the tables below for more assert methods): Method Checks that New in ---------------------------------------------------------------------------------------------------- *note assertEqual(a, b): bb5. ‘a == b’ *note assertNotEqual(a, b): bb6. ‘a != b’ *note assertTrue(x): bb4. ‘bool(x) is True’ *note assertFalse(x): cc7. ‘bool(x) is False’ *note assertIs(a, b): ccf. ‘a is b’ 3.1 *note assertIsNot(a, b): cd0. ‘a is not b’ 3.1 *note assertIsNone(x): ccd. ‘x is None’ 3.1 *note assertIsNotNone(x): cce. ‘x is not None’ 3.1 *note assertIn(a, b): cd8. ‘a in b’ 3.1 *note assertNotIn(a, b): cd9. ‘a not in b’ 3.1 *note assertIsInstance(a, b): cd1. ‘isinstance(a, b)’ 3.2 *note assertNotIsInstance(a, b): cd2. ‘not isinstance(a, b)’ 3.2 All the assert methods accept a `msg' argument that, if specified, is used as the error message on failure (see also *note longMessage: cc8.). Note that the `msg' keyword argument can be passed to *note assertRaises(): aba, *note assertRaisesRegex(): abb, *note assertWarns(): abc, *note assertWarnsRegex(): abd. only when they are used as a context manager. -- Method: assertEqual (first, second, msg=None) Test that `first' and `second' are equal. If the values do not compare equal, the test will fail. In addition, if `first' and `second' are the exact same type and one of list, tuple, dict, set, frozenset or str or any type that a subclass registers with *note addTypeEqualityFunc(): ce1. the type-specific equality function will be called in order to generate a more useful default error message (see also the *note list of type-specific methods: 3054.). Changed in version 3.1: Added the automatic calling of type-specific equality function. Changed in version 3.2: *note assertMultiLineEqual(): cd7. added as the default type equality function for comparing strings. -- Method: assertNotEqual (first, second, msg=None) Test that `first' and `second' are not equal. If the values do compare equal, the test will fail. -- Method: assertTrue (expr, msg=None) -- Method: assertFalse (expr, msg=None) Test that `expr' is true (or false). Note that this is equivalent to ‘bool(expr) is True’ and not to ‘expr is True’ (use ‘assertIs(expr, True)’ for the latter). This method should also be avoided when more specific methods are available (e.g. ‘assertEqual(a, b)’ instead of ‘assertTrue(a == b)’), because they provide a better error message in case of failure. -- Method: assertIs (first, second, msg=None) -- Method: assertIsNot (first, second, msg=None) Test that `first' and `second' are (or are not) the same object. New in version 3.1. -- Method: assertIsNone (expr, msg=None) -- Method: assertIsNotNone (expr, msg=None) Test that `expr' is (or is not) ‘None’. New in version 3.1. -- Method: assertIn (member, container, msg=None) -- Method: assertNotIn (member, container, msg=None) Test that `member' is (or is not) in `container'. New in version 3.1. -- Method: assertIsInstance (obj, cls, msg=None) -- Method: assertNotIsInstance (obj, cls, msg=None) Test that `obj' is (or is not) an instance of `cls' (which can be a class or a tuple of classes, as supported by *note isinstance(): 44f.). To check for the exact type, use *note assertIs(type(obj), cls): ccf. New in version 3.2. It is also possible to check the production of exceptions, warnings, and log messages using the following methods: Method Checks that New in -------------------------------------------------------------------------------------------------------------------------- *note assertRaises(exc, fun, *args, **kwds): aba. ‘fun(*args, **kwds)’ raises `exc' *note assertRaisesRegex(exc, r, fun, *args, **kwds): abb. ‘fun(*args, **kwds)’ raises `exc' and 3.1 the message matches regex `r' *note assertWarns(warn, fun, *args, **kwds): abc. ‘fun(*args, **kwds)’ raises `warn' 3.2 *note assertWarnsRegex(warn, r, fun, *args, **kwds): abd. ‘fun(*args, **kwds)’ raises `warn' and 3.2 the message matches regex `r' *note assertLogs(logger, level): 905. The ‘with’ block logs on `logger' with 3.4 minimum `level' -- Method: assertRaises (exception, callable, *args, **kwds) -- Method: assertRaises (exception, *, msg=None) Test that an exception is raised when `callable' is called with any positional or keyword arguments that are also passed to *note assertRaises(): aba. The test passes if `exception' is raised, is an error if another exception is raised, or fails if no exception is raised. To catch any of a group of exceptions, a tuple containing the exception classes may be passed as `exception'. If only the `exception' and possibly the `msg' arguments are given, return a context manager so that the code under test can be written inline rather than as a function: with self.assertRaises(SomeException): do_something() When used as a context manager, *note assertRaises(): aba. accepts the additional keyword argument `msg'. The context manager will store the caught exception object in its ‘exception’ attribute. This can be useful if the intention is to perform additional checks on the exception raised: with self.assertRaises(SomeException) as cm: do_something() the_exception = cm.exception self.assertEqual(the_exception.error_code, 3) Changed in version 3.1: Added the ability to use *note assertRaises(): aba. as a context manager. Changed in version 3.2: Added the ‘exception’ attribute. Changed in version 3.3: Added the `msg' keyword argument when used as a context manager. -- Method: assertRaisesRegex (exception, regex, callable, *args, **kwds) -- Method: assertRaisesRegex (exception, regex, *, msg=None) Like *note assertRaises(): aba. but also tests that `regex' matches on the string representation of the raised exception. `regex' may be a regular expression object or a string containing a regular expression suitable for use by *note re.search(): bb2. Examples: self.assertRaisesRegex(ValueError, "invalid literal for.*XYZ'$", int, 'XYZ') or: with self.assertRaisesRegex(ValueError, 'literal'): int('XYZ') New in version 3.1: Added under the name ‘assertRaisesRegexp’. Changed in version 3.2: Renamed to *note assertRaisesRegex(): abb. Changed in version 3.3: Added the `msg' keyword argument when used as a context manager. -- Method: assertWarns (warning, callable, *args, **kwds) -- Method: assertWarns (warning, *, msg=None) Test that a warning is triggered when `callable' is called with any positional or keyword arguments that are also passed to *note assertWarns(): abc. The test passes if `warning' is triggered and fails if it isn’t. Any exception is an error. To catch any of a group of warnings, a tuple containing the warning classes may be passed as `warnings'. If only the `warning' and possibly the `msg' arguments are given, return a context manager so that the code under test can be written inline rather than as a function: with self.assertWarns(SomeWarning): do_something() When used as a context manager, *note assertWarns(): abc. accepts the additional keyword argument `msg'. The context manager will store the caught warning object in its ‘warning’ attribute, and the source line which triggered the warnings in the ‘filename’ and ‘lineno’ attributes. This can be useful if the intention is to perform additional checks on the warning caught: with self.assertWarns(SomeWarning) as cm: do_something() self.assertIn('myfile.py', cm.filename) self.assertEqual(320, cm.lineno) This method works regardless of the warning filters in place when it is called. New in version 3.2. Changed in version 3.3: Added the `msg' keyword argument when used as a context manager. -- Method: assertWarnsRegex (warning, regex, callable, *args, **kwds) -- Method: assertWarnsRegex (warning, regex, *, msg=None) Like *note assertWarns(): abc. but also tests that `regex' matches on the message of the triggered warning. `regex' may be a regular expression object or a string containing a regular expression suitable for use by *note re.search(): bb2. Example: self.assertWarnsRegex(DeprecationWarning, r'legacy_function\(\) is deprecated', legacy_function, 'XYZ') or: with self.assertWarnsRegex(RuntimeWarning, 'unsafe frobnicating'): frobnicate('/etc/passwd') New in version 3.2. Changed in version 3.3: Added the `msg' keyword argument when used as a context manager. -- Method: assertLogs (logger=None, level=None) A context manager to test that at least one message is logged on the `logger' or one of its children, with at least the given `level'. If given, `logger' should be a *note logging.Logger: 3a7. object or a *note str: 330. giving the name of a logger. The default is the root logger, which will catch all messages that were not blocked by a non-propagating descendent logger. If given, `level' should be either a numeric logging level or its string equivalent (for example either ‘"ERROR"’ or ‘logging.ERROR’). The default is ‘logging.INFO’. The test passes if at least one message emitted inside the ‘with’ block matches the `logger' and `level' conditions, otherwise it fails. The object returned by the context manager is a recording helper which keeps tracks of the matching log messages. It has two attributes: -- Attribute: records A list of *note logging.LogRecord: 906. objects of the matching log messages. -- Attribute: output A list of *note str: 330. objects with the formatted output of matching messages. Example: with self.assertLogs('foo', level='INFO') as cm: logging.getLogger('foo').info('first message') logging.getLogger('foo.bar').error('second message') self.assertEqual(cm.output, ['INFO:foo:first message', 'ERROR:foo.bar:second message']) New in version 3.4. There are also other methods used to perform more specific checks, such as: Method Checks that New in ---------------------------------------------------------------------------------------------------- *note assertAlmostEqual(a, b): bb7. ‘round(a-b, 7) == 0’ *note assertNotAlmostEqual(a, b): bb8. ‘round(a-b, 7) != 0’ *note assertGreater(a, b): cd3. ‘a > b’ 3.1 *note assertGreaterEqual(a, b): cd4. ‘a >= b’ 3.1 *note assertLess(a, b): cd5. ‘a < b’ 3.1 *note assertLessEqual(a, b): cd6. ‘a <= b’ 3.1 *note assertRegex(s, r): bb1. ‘r.search(s)’ 3.1 *note assertNotRegex(s, r): 3057. ‘not r.search(s)’ 3.2 *note assertCountEqual(a, b): baf. `a' and `b' have the same elements 3.2 in the same number, regardless of their order. -- Method: assertAlmostEqual (first, second, places=7, msg=None, delta=None) -- Method: assertNotAlmostEqual (first, second, places=7, msg=None, delta=None) Test that `first' and `second' are approximately (or not approximately) equal by computing the difference, rounding to the given number of decimal `places' (default 7), and comparing to zero. Note that these methods round the values to the given number of `decimal places' (i.e. like the *note round(): c6d. function) and not `significant digits'. If `delta' is supplied instead of `places' then the difference between `first' and `second' must be less or equal to (or greater than) `delta'. Supplying both `delta' and `places' raises a *note TypeError: 192. Changed in version 3.2: *note assertAlmostEqual(): bb7. automatically considers almost equal objects that compare equal. *note assertNotAlmostEqual(): bb8. automatically fails if the objects compare equal. Added the `delta' keyword argument. -- Method: assertGreater (first, second, msg=None) -- Method: assertGreaterEqual (first, second, msg=None) -- Method: assertLess (first, second, msg=None) -- Method: assertLessEqual (first, second, msg=None) Test that `first' is respectively >, >=, < or <= than `second' depending on the method name. If not, the test will fail: >>> self.assertGreaterEqual(3, 4) AssertionError: "3" unexpectedly not greater than or equal to "4" New in version 3.1. -- Method: assertRegex (text, regex, msg=None) -- Method: assertNotRegex (text, regex, msg=None) Test that a `regex' search matches (or does not match) `text'. In case of failure, the error message will include the pattern and the `text' (or the pattern and the part of `text' that unexpectedly matched). `regex' may be a regular expression object or a string containing a regular expression suitable for use by *note re.search(): bb2. New in version 3.1: Added under the name ‘assertRegexpMatches’. Changed in version 3.2: The method ‘assertRegexpMatches()’ has been renamed to *note assertRegex(): bb1. New in version 3.2: *note assertNotRegex(): 3057. New in version 3.5: The name ‘assertNotRegexpMatches’ is a deprecated alias for *note assertNotRegex(): 3057. -- Method: assertCountEqual (first, second, msg=None) Test that sequence `first' contains the same elements as `second', regardless of their order. When they don’t, an error message listing the differences between the sequences will be generated. Duplicate elements are `not' ignored when comparing `first' and `second'. It verifies whether each element has the same count in both sequences. Equivalent to: ‘assertEqual(Counter(list(first)), Counter(list(second)))’ but works with sequences of unhashable objects as well. New in version 3.2. The *note assertEqual(): bb5. method dispatches the equality check for objects of the same type to different type-specific methods. These methods are already implemented for most of the built-in types, but it’s also possible to register new methods using *note addTypeEqualityFunc(): ce1.: -- Method: addTypeEqualityFunc (typeobj, function) Registers a type-specific method called by *note assertEqual(): bb5. to check if two objects of exactly the same `typeobj' (not subclasses) compare equal. `function' must take two positional arguments and a third msg=None keyword argument just as *note assertEqual(): bb5. does. It must raise *note self.failureException(msg): 3058. when inequality between the first two parameters is detected – possibly providing useful information and explaining the inequalities in details in the error message. New in version 3.1. The list of type-specific methods automatically used by *note assertEqual(): bb5. are summarized in the following table. Note that it’s usually not necessary to invoke these methods directly. Method Used to compare New in --------------------------------------------------------------------------------------------------- *note assertMultiLineEqual(a, b): cd7. strings 3.1 *note assertSequenceEqual(a, b): cdd. sequences 3.1 *note assertListEqual(a, b): cdb. lists 3.1 *note assertTupleEqual(a, b): cdc. tuples 3.1 *note assertSetEqual(a, b): cda. sets or frozensets 3.1 *note assertDictEqual(a, b): cde. dicts 3.1 -- Method: assertMultiLineEqual (first, second, msg=None) Test that the multiline string `first' is equal to the string `second'. When not equal a diff of the two strings highlighting the differences will be included in the error message. This method is used by default when comparing strings with *note assertEqual(): bb5. New in version 3.1. -- Method: assertSequenceEqual (first, second, msg=None, seq_type=None) Tests that two sequences are equal. If a `seq_type' is supplied, both `first' and `second' must be instances of `seq_type' or a failure will be raised. If the sequences are different an error message is constructed that shows the difference between the two. This method is not called directly by *note assertEqual(): bb5, but it’s used to implement *note assertListEqual(): cdb. and *note assertTupleEqual(): cdc. New in version 3.1. -- Method: assertListEqual (first, second, msg=None) -- Method: assertTupleEqual (first, second, msg=None) Tests that two lists or tuples are equal. If not, an error message is constructed that shows only the differences between the two. An error is also raised if either of the parameters are of the wrong type. These methods are used by default when comparing lists or tuples with *note assertEqual(): bb5. New in version 3.1. -- Method: assertSetEqual (first, second, msg=None) Tests that two sets are equal. If not, an error message is constructed that lists the differences between the sets. This method is used by default when comparing sets or frozensets with *note assertEqual(): bb5. Fails if either of `first' or `second' does not have a ‘set.difference()’ method. New in version 3.1. -- Method: assertDictEqual (first, second, msg=None) Test that two dictionaries are equal. If not, an error message is constructed that shows the differences in the dictionaries. This method will be used by default to compare dictionaries in calls to *note assertEqual(): bb5. New in version 3.1. Finally the *note TestCase: 8ff. provides the following methods and attributes: -- Method: fail (msg=None) Signals a test failure unconditionally, with `msg' or ‘None’ for the error message. -- Attribute: failureException This class attribute gives the exception raised by the test method. If a test framework needs to use a specialized exception, possibly to carry additional information, it must subclass this exception in order to “play fair” with the framework. The initial value of this attribute is *note AssertionError: 1223. -- Attribute: longMessage This class attribute determines what happens when a custom failure message is passed as the msg argument to an assertXYY call that fails. ‘True’ is the default value. In this case, the custom message is appended to the end of the standard failure message. When set to ‘False’, the custom message replaces the standard message. The class setting can be overridden in individual test methods by assigning an instance attribute, self.longMessage, to ‘True’ or ‘False’ before calling the assert methods. The class setting gets reset before each test call. New in version 3.1. -- Attribute: maxDiff This attribute controls the maximum length of diffs output by assert methods that report diffs on failure. It defaults to 80*8 characters. Assert methods affected by this attribute are *note assertSequenceEqual(): cdd. (including all the sequence comparison methods that delegate to it), *note assertDictEqual(): cde. and *note assertMultiLineEqual(): cd7. Setting ‘maxDiff’ to ‘None’ means that there is no maximum length of diffs. New in version 3.2. Testing frameworks can use the following methods to collect information on the test: -- Method: countTestCases () Return the number of tests represented by this test object. For *note TestCase: 8ff. instances, this will always be ‘1’. -- Method: defaultTestResult () Return an instance of the test result class that should be used for this test case class (if no other result instance is provided to the *note run(): abe. method). For *note TestCase: 8ff. instances, this will always be an instance of *note TestResult: abf.; subclasses of *note TestCase: 8ff. should override this as necessary. -- Method: id () Return a string identifying the specific test case. This is usually the full name of the test method, including the module and class name. -- Method: shortDescription () Returns a description of the test, or ‘None’ if no description has been provided. The default implementation of this method returns the first line of the test method’s docstring, if available, or ‘None’. Changed in version 3.1: In 3.1 this was changed to add the test name to the short description even in the presence of a docstring. This caused compatibility issues with unittest extensions and adding the test name was moved to the *note TextTestResult: 305e. in Python 3.2. -- Method: addCleanup (function, *args, **kwargs) Add a function to be called after *note tearDown(): ccc. to cleanup resources used during the test. Functions will be called in reverse order to the order they are added (LIFO). They are called with any arguments and keyword arguments passed into *note addCleanup(): 2a2. when they are added. If *note setUp(): ccb. fails, meaning that *note tearDown(): ccc. is not called, then any cleanup functions added will still be called. New in version 3.1. -- Method: doCleanups () This method is called unconditionally after *note tearDown(): ccc, or after *note setUp(): ccb. if *note setUp(): ccb. raises an exception. It is responsible for calling all the cleanup functions added by *note addCleanup(): 2a2. If you need cleanup functions to be called `prior' to *note tearDown(): ccc. then you can call *note doCleanups(): cca. yourself. *note doCleanups(): cca. pops methods off the stack of cleanup functions one at a time, so it can be called at any time. New in version 3.1. -- Method: classmethod addClassCleanup (function, /, *args, **kwargs) Add a function to be called after *note tearDownClass(): cc9. to cleanup resources used during the test class. Functions will be called in reverse order to the order they are added (LIFO). They are called with any arguments and keyword arguments passed into *note addClassCleanup(): 24b. when they are added. If *note setUpClass(): 24c. fails, meaning that *note tearDownClass(): cc9. is not called, then any cleanup functions added will still be called. New in version 3.8. -- Method: classmethod doClassCleanups () This method is called unconditionally after *note tearDownClass(): cc9, or after *note setUpClass(): 24c. if *note setUpClass(): 24c. raises an exception. It is responsible for calling all the cleanup functions added by *note addClassCleanup(): 24b. If you need cleanup functions to be called `prior' to *note tearDownClass(): cc9. then you can call *note doClassCleanups(): 305f. yourself. *note doClassCleanups(): 305f. pops methods off the stack of cleanup functions one at a time, so it can be called at any time. New in version 3.8. -- Class: unittest.IsolatedAsyncioTestCase (methodName='runTest') This class provides an API similar to *note TestCase: 8ff. and also accepts coroutines as test functions. New in version 3.8. -- Method: coroutine asyncSetUp () Method called to prepare the test fixture. This is called after ‘setUp()’. This is called immediately before calling the test method; other than *note AssertionError: 1223. or *note SkipTest: 903, any exception raised by this method will be considered an error rather than a test failure. The default implementation does nothing. -- Method: coroutine asyncTearDown () Method called immediately after the test method has been called and the result recorded. This is called before ‘tearDown()’. This is called even if the test method raised an exception, so the implementation in subclasses may need to be particularly careful about checking internal state. Any exception, other than *note AssertionError: 1223. or *note SkipTest: 903, raised by this method will be considered an additional error rather than a test failure (thus increasing the total number of reported errors). This method will only be called if the *note asyncSetUp(): 3060. succeeds, regardless of the outcome of the test method. The default implementation does nothing. -- Method: addAsyncCleanup (function, /, *args, **kwargs) This method accepts a coroutine that can be used as a cleanup function. -- Method: run (result=None) Sets up a new event loop to run the test, collecting the result into the *note TestResult: abf. object passed as `result'. If `result' is omitted or ‘None’, a temporary result object is created (by calling the ‘defaultTestResult()’ method) and used. The result object is returned to *note run(): 3063.’s caller. At the end of the test all the tasks in the event loop are cancelled. An example illustrating the order: from unittest import IsolatedAsyncioTestCase events = [] class Test(IsolatedAsyncioTestCase): def setUp(self): events.append("setUp") async def asyncSetUp(self): self._async_connection = await AsyncConnection() events.append("asyncSetUp") async def test_response(self): events.append("test_response") response = await self._async_connection.get("https://example.com") self.assertEqual(response.status_code, 200) self.addAsyncCleanup(self.on_cleanup) def tearDown(self): events.append("tearDown") async def asyncTearDown(self): await self._async_connection.close() events.append("asyncTearDown") async def on_cleanup(self): events.append("cleanup") if __name__ == "__main__": unittest.main() After running the test, ‘events’ would contain ‘["setUp", "asyncSetUp", "test_response", "asyncTearDown", "tearDown", "cleanup"]’. -- Class: unittest.FunctionTestCase (testFunc, setUp=None, tearDown=None, description=None) This class implements the portion of the *note TestCase: 8ff. interface which allows the test runner to drive the test, but does not provide the methods which test code can use to check and report errors. This is used to create test cases using legacy test code, allowing it to be integrated into a *note unittest: 11b.-based test framework. * Menu: * Deprecated aliases::  File: python.info, Node: Deprecated aliases, Up: Test cases 5.26.4.11 Deprecated aliases ............................ For historical reasons, some of the *note TestCase: 8ff. methods had one or more aliases that are now deprecated. The following table lists the correct names along with their deprecated aliases: Method Name Deprecated alias Deprecated alias ------------------------------------------------------------------------------------------ *note assertEqual(): bb5. failUnlessEqual assertEquals *note assertNotEqual(): bb6. failIfEqual assertNotEquals *note assertTrue(): bb4. failUnless assert_ *note assertFalse(): cc7. failIf *note assertRaises(): aba. failUnlessRaises *note assertAlmostEqual(): bb7. failUnlessAlmostEqual assertAlmostEquals *note assertNotAlmostEqual(): bb8. failIfAlmostEqual assertNotAlmostEquals *note assertRegex(): bb1. assertRegexpMatches *note assertNotRegex(): 3057. assertNotRegexpMatches *note assertRaisesRegex(): abb. assertRaisesRegexp Deprecated since version 3.1: The fail* aliases listed in the second column have been deprecated. Deprecated since version 3.2: The assert* aliases listed in the third column have been deprecated. Deprecated since version 3.2: ‘assertRegexpMatches’ and ‘assertRaisesRegexp’ have been renamed to *note assertRegex(): bb1. and *note assertRaisesRegex(): abb. Deprecated since version 3.5: The ‘assertNotRegexpMatches’ name is deprecated in favor of *note assertNotRegex(): 3057.  File: python.info, Node: Grouping tests, Next: Loading and running tests, Prev: Test cases, Up: Classes and functions 5.26.4.12 Grouping tests ........................ -- Class: unittest.TestSuite (tests=()) This class represents an aggregation of individual test cases and test suites. The class presents the interface needed by the test runner to allow it to be run as any other test case. Running a *note TestSuite: 6ce. instance is the same as iterating over the suite, running each test individually. If `tests' is given, it must be an iterable of individual test cases or other test suites that will be used to build the suite initially. Additional methods are provided to add test cases and suites to the collection later on. *note TestSuite: 6ce. objects behave much like *note TestCase: 8ff. objects, except they do not actually implement a test. Instead, they are used to aggregate tests into groups of tests that should be run together. Some additional methods are available to add tests to *note TestSuite: 6ce. instances: -- Method: addTest (test) Add a *note TestCase: 8ff. or *note TestSuite: 6ce. to the suite. -- Method: addTests (tests) Add all the tests from an iterable of *note TestCase: 8ff. and *note TestSuite: 6ce. instances to this test suite. This is equivalent to iterating over `tests', calling *note addTest(): 3067. for each element. *note TestSuite: 6ce. shares the following methods with *note TestCase: 8ff.: -- Method: run (result) Run the tests associated with this suite, collecting the result into the test result object passed as `result'. Note that unlike *note TestCase.run(): abe, *note TestSuite.run(): 3069. requires the result object to be passed in. -- Method: debug () Run the tests associated with this suite without collecting the result. This allows exceptions raised by the test to be propagated to the caller and can be used to support running tests under a debugger. -- Method: countTestCases () Return the number of tests represented by this test object, including all individual tests and sub-suites. -- Method: __iter__ () Tests grouped by a *note TestSuite: 6ce. are always accessed by iteration. Subclasses can lazily provide tests by overriding *note __iter__(): 962. Note that this method may be called several times on a single suite (for example when counting tests or comparing for equality) so the tests returned by repeated iterations before *note TestSuite.run(): 3069. must be the same for each call iteration. After *note TestSuite.run(): 3069, callers should not rely on the tests returned by this method unless the caller uses a subclass that overrides ‘TestSuite._removeTestAtIndex()’ to preserve test references. Changed in version 3.2: In earlier versions the *note TestSuite: 6ce. accessed tests directly rather than through iteration, so overriding *note __iter__(): 962. wasn’t sufficient for providing tests. Changed in version 3.4: In earlier versions the *note TestSuite: 6ce. held references to each *note TestCase: 8ff. after *note TestSuite.run(): 3069. Subclasses can restore that behavior by overriding ‘TestSuite._removeTestAtIndex()’. In the typical usage of a *note TestSuite: 6ce. object, the *note run(): 3069. method is invoked by a ‘TestRunner’ rather than by the end-user test harness.  File: python.info, Node: Loading and running tests, Prev: Grouping tests, Up: Classes and functions 5.26.4.13 Loading and running tests ................................... -- Class: unittest.TestLoader The *note TestLoader: 782. class is used to create test suites from classes and modules. Normally, there is no need to create an instance of this class; the *note unittest: 11b. module provides an instance that can be shared as *note unittest.defaultTestLoader: 306d. Using a subclass or instance, however, allows customization of some configurable properties. *note TestLoader: 782. objects have the following attributes: -- Attribute: errors A list of the non-fatal errors encountered while loading tests. Not reset by the loader at any point. Fatal errors are signalled by the relevant a method raising an exception to the caller. Non-fatal errors are also indicated by a synthetic test that will raise the original error when run. New in version 3.5. *note TestLoader: 782. objects have the following methods: -- Method: loadTestsFromTestCase (testCaseClass) Return a suite of all test cases contained in the *note TestCase: 8ff.-derived ‘testCaseClass’. A test case instance is created for each method named by *note getTestCaseNames(): 306f. By default these are the method names beginning with ‘test’. If *note getTestCaseNames(): 306f. returns no methods, but the ‘runTest()’ method is implemented, a single test case is created for that method instead. -- Method: loadTestsFromModule (module, pattern=None) Return a suite of all test cases contained in the given module. This method searches `module' for classes derived from *note TestCase: 8ff. and creates an instance of the class for each test method defined for the class. Note: While using a hierarchy of *note TestCase: 8ff.-derived classes can be convenient in sharing fixtures and helper functions, defining test methods on base classes that are not intended to be instantiated directly does not play well with this method. Doing so, however, can be useful when the fixtures are different and defined in subclasses. If a module provides a ‘load_tests’ function it will be called to load the tests. This allows modules to customize test loading. This is the *note load_tests protocol: 3040. The `pattern' argument is passed as the third argument to ‘load_tests’. Changed in version 3.2: Support for ‘load_tests’ added. Changed in version 3.5: The undocumented and unofficial `use_load_tests' default argument is deprecated and ignored, although it is still accepted for backward compatibility. The method also now accepts a keyword-only argument `pattern' which is passed to ‘load_tests’ as the third argument. -- Method: loadTestsFromName (name, module=None) Return a suite of all test cases given a string specifier. The specifier `name' is a “dotted name” that may resolve either to a module, a test case class, a test method within a test case class, a *note TestSuite: 6ce. instance, or a callable object which returns a *note TestCase: 8ff. or *note TestSuite: 6ce. instance. These checks are applied in the order listed here; that is, a method on a possible test case class will be picked up as “a test method within a test case class”, rather than “a callable object”. For example, if you have a module ‘SampleTests’ containing a *note TestCase: 8ff.-derived class ‘SampleTestCase’ with three test methods (‘test_one()’, ‘test_two()’, and ‘test_three()’), the specifier ‘'SampleTests.SampleTestCase'’ would cause this method to return a suite which will run all three test methods. Using the specifier ‘'SampleTests.SampleTestCase.test_two'’ would cause it to return a test suite which will run only the ‘test_two()’ test method. The specifier can refer to modules and packages which have not been imported; they will be imported as a side-effect. The method optionally resolves `name' relative to the given `module'. Changed in version 3.5: If an *note ImportError: 334. or *note AttributeError: 39b. occurs while traversing `name' then a synthetic test that raises that error when run will be returned. These errors are included in the errors accumulated by self.errors. -- Method: loadTestsFromNames (names, module=None) Similar to *note loadTestsFromName(): cdf, but takes a sequence of names rather than a single name. The return value is a test suite which supports all the tests defined for each name. -- Method: getTestCaseNames (testCaseClass) Return a sorted sequence of method names found within `testCaseClass'; this should be a subclass of *note TestCase: 8ff. -- Method: discover (start_dir, pattern='test*.py', top_level_dir=None) Find all the test modules by recursing into subdirectories from the specified start directory, and return a TestSuite object containing them. Only test files that match `pattern' will be loaded. (Using shell style pattern matching.) Only module names that are importable (i.e. are valid Python identifiers) will be loaded. All test modules must be importable from the top level of the project. If the start directory is not the top level directory then the top level directory must be specified separately. If importing a module fails, for example due to a syntax error, then this will be recorded as a single error and discovery will continue. If the import failure is due to *note SkipTest: 903. being raised, it will be recorded as a skip instead of an error. If a package (a directory containing a file named ‘__init__.py’) is found, the package will be checked for a ‘load_tests’ function. If this exists then it will be called ‘package.load_tests(loader, tests, pattern)’. Test discovery takes care to ensure that a package is only checked for tests once during an invocation, even if the load_tests function itself calls ‘loader.discover’. If ‘load_tests’ exists then discovery does `not' recurse into the package, ‘load_tests’ is responsible for loading all tests in the package. The pattern is deliberately not stored as a loader attribute so that packages can continue discovery themselves. `top_level_dir' is stored so ‘load_tests’ does not need to pass this argument in to ‘loader.discover()’. `start_dir' can be a dotted module name as well as a directory. New in version 3.2. Changed in version 3.4: Modules that raise *note SkipTest: 903. on import are recorded as skips, not errors. Changed in version 3.4: `start_dir' can be a *note namespace packages: 1158. Changed in version 3.4: Paths are sorted before being imported so that execution order is the same even if the underlying file system’s ordering is not dependent on file name. Changed in version 3.5: Found packages are now checked for ‘load_tests’ regardless of whether their path matches `pattern', because it is impossible for a package name to match the default pattern. The following attributes of a *note TestLoader: 782. can be configured either by subclassing or assignment on an instance: -- Attribute: testMethodPrefix String giving the prefix of method names which will be interpreted as test methods. The default value is ‘'test'’. This affects *note getTestCaseNames(): 306f. and all the ‘loadTestsFrom*()’ methods. -- Attribute: sortTestMethodsUsing Function to be used to compare method names when sorting them in *note getTestCaseNames(): 306f. and all the ‘loadTestsFrom*()’ methods. -- Attribute: suiteClass Callable object that constructs a test suite from a list of tests. No methods on the resulting object are needed. The default value is the *note TestSuite: 6ce. class. This affects all the ‘loadTestsFrom*()’ methods. -- Attribute: testNamePatterns List of Unix shell-style wildcard test name patterns that test methods have to match to be included in test suites (see ‘-v’ option). If this attribute is not ‘None’ (the default), all test methods to be included in test suites must match one of the patterns in this list. Note that matches are always performed using *note fnmatch.fnmatchcase(): 193b, so unlike patterns passed to the ‘-v’ option, simple substring patterns will have to be converted using ‘*’ wildcards. This affects all the ‘loadTestsFrom*()’ methods. New in version 3.7. -- Class: unittest.TestResult This class is used to compile information about which tests have succeeded and which have failed. A *note TestResult: abf. object stores the results of a set of tests. The *note TestCase: 8ff. and *note TestSuite: 6ce. classes ensure that results are properly recorded; test authors do not need to worry about recording the outcome of tests. Testing frameworks built on top of *note unittest: 11b. may want access to the *note TestResult: abf. object generated by running a set of tests for reporting purposes; a *note TestResult: abf. instance is returned by the ‘TestRunner.run()’ method for this purpose. *note TestResult: abf. instances have the following attributes that will be of interest when inspecting the results of running a set of tests: -- Attribute: errors A list containing 2-tuples of *note TestCase: 8ff. instances and strings holding formatted tracebacks. Each tuple represents a test which raised an unexpected exception. -- Attribute: failures A list containing 2-tuples of *note TestCase: 8ff. instances and strings holding formatted tracebacks. Each tuple represents a test where a failure was explicitly signalled using the ‘TestCase.assert*()’ methods. -- Attribute: skipped A list containing 2-tuples of *note TestCase: 8ff. instances and strings holding the reason for skipping the test. New in version 3.1. -- Attribute: expectedFailures A list containing 2-tuples of *note TestCase: 8ff. instances and strings holding formatted tracebacks. Each tuple represents an expected failure or error of the test case. -- Attribute: unexpectedSuccesses A list containing *note TestCase: 8ff. instances that were marked as expected failures, but succeeded. -- Attribute: shouldStop Set to ‘True’ when the execution of tests should stop by *note stop(): 307a. -- Attribute: testsRun The total number of tests run so far. -- Attribute: buffer If set to true, ‘sys.stdout’ and ‘sys.stderr’ will be buffered in between *note startTest(): 307d. and *note stopTest(): 307e. being called. Collected output will only be echoed onto the real ‘sys.stdout’ and ‘sys.stderr’ if the test fails or errors. Any output is also attached to the failure / error message. New in version 3.2. -- Attribute: failfast If set to true *note stop(): 307a. will be called on the first failure or error, halting the test run. New in version 3.2. -- Attribute: tb_locals If set to true then local variables will be shown in tracebacks. New in version 3.5. -- Method: wasSuccessful () Return ‘True’ if all tests run so far have passed, otherwise returns ‘False’. Changed in version 3.4: Returns ‘False’ if there were any *note unexpectedSuccesses: 3078. from tests marked with the *note expectedFailure(): 3049. decorator. -- Method: stop () This method can be called to signal that the set of tests being run should be aborted by setting the *note shouldStop: 3079. attribute to ‘True’. ‘TestRunner’ objects should respect this flag and return without running any additional tests. For example, this feature is used by the *note TextTestRunner: 3082. class to stop the test framework when the user signals an interrupt from the keyboard. Interactive tools which provide ‘TestRunner’ implementations can use this in a similar manner. The following methods of the *note TestResult: abf. class are used to maintain the internal data structures, and may be extended in subclasses to support additional reporting requirements. This is particularly useful in building tools which support interactive reporting while tests are being run. -- Method: startTest (test) Called when the test case `test' is about to be run. -- Method: stopTest (test) Called after the test case `test' has been executed, regardless of the outcome. -- Method: startTestRun () Called once before any tests are executed. New in version 3.1. -- Method: stopTestRun () Called once after all tests are executed. New in version 3.1. -- Method: addError (test, err) Called when the test case `test' raises an unexpected exception. `err' is a tuple of the form returned by *note sys.exc_info(): c5f.: ‘(type, value, traceback)’. The default implementation appends a tuple ‘(test, formatted_err)’ to the instance’s *note errors: 3074. attribute, where `formatted_err' is a formatted traceback derived from `err'. -- Method: addFailure (test, err) Called when the test case `test' signals a failure. `err' is a tuple of the form returned by *note sys.exc_info(): c5f.: ‘(type, value, traceback)’. The default implementation appends a tuple ‘(test, formatted_err)’ to the instance’s *note failures: 3075. attribute, where `formatted_err' is a formatted traceback derived from `err'. -- Method: addSuccess (test) Called when the test case `test' succeeds. The default implementation does nothing. -- Method: addSkip (test, reason) Called when the test case `test' is skipped. `reason' is the reason the test gave for skipping. The default implementation appends a tuple ‘(test, reason)’ to the instance’s *note skipped: 3076. attribute. -- Method: addExpectedFailure (test, err) Called when the test case `test' fails or errors, but was marked with the *note expectedFailure(): 3049. decorator. The default implementation appends a tuple ‘(test, formatted_err)’ to the instance’s *note expectedFailures: 3077. attribute, where `formatted_err' is a formatted traceback derived from `err'. -- Method: addUnexpectedSuccess (test) Called when the test case `test' was marked with the *note expectedFailure(): 3049. decorator, but succeeded. The default implementation appends the test to the instance’s *note unexpectedSuccesses: 3078. attribute. -- Method: addSubTest (test, subtest, outcome) Called when a subtest finishes. `test' is the test case corresponding to the test method. `subtest' is a custom *note TestCase: 8ff. instance describing the subtest. If `outcome' is *note None: 157, the subtest succeeded. Otherwise, it failed with an exception where `outcome' is a tuple of the form returned by *note sys.exc_info(): c5f.: ‘(type, value, traceback)’. The default implementation does nothing when the outcome is a success, and records subtest failures as normal failures. New in version 3.4. -- Class: unittest.TextTestResult (stream, descriptions, verbosity) A concrete implementation of *note TestResult: abf. used by the *note TextTestRunner: 3082. New in version 3.2: This class was previously named ‘_TextTestResult’. The old name still exists as an alias but is deprecated. -- Data: unittest.defaultTestLoader Instance of the *note TestLoader: 782. class intended to be shared. If no customization of the *note TestLoader: 782. is needed, this instance can be used instead of repeatedly creating new instances. -- Class: unittest.TextTestRunner (stream=None, descriptions=True, verbosity=1, failfast=False, buffer=False, resultclass=None, warnings=None, *, tb_locals=False) A basic test runner implementation that outputs results to a stream. If `stream' is ‘None’, the default, *note sys.stderr: 30f. is used as the output stream. This class has a few configurable parameters, but is essentially very simple. Graphical applications which run test suites should provide alternate implementations. Such implementations should accept ‘**kwargs’ as the interface to construct runners changes when features are added to unittest. By default this runner shows *note DeprecationWarning: 278, *note PendingDeprecationWarning: 279, *note ResourceWarning: 4d0. and *note ImportWarning: 5d8. even if they are *note ignored by default: 308a. Deprecation warnings caused by *note deprecated unittest methods: bb9. are also special-cased and, when the warning filters are ‘'default'’ or ‘'always'’, they will appear only once per-module, in order to avoid too many warning messages. This behavior can be overridden using Python’s ‘-Wd’ or ‘-Wa’ options (see *note Warning control: fe6.) and leaving `warnings' to ‘None’. Changed in version 3.2: Added the ‘warnings’ argument. Changed in version 3.2: The default stream is set to *note sys.stderr: 30f. at instantiation time rather than import time. Changed in version 3.5: Added the tb_locals parameter. -- Method: _makeResult () This method returns the instance of ‘TestResult’ used by *note run(): 308c. It is not intended to be called directly, but can be overridden in subclasses to provide a custom ‘TestResult’. ‘_makeResult()’ instantiates the class or callable passed in the ‘TextTestRunner’ constructor as the ‘resultclass’ argument. It defaults to *note TextTestResult: 305e. if no ‘resultclass’ is provided. The result class is instantiated with the following arguments: stream, descriptions, verbosity -- Method: run (test) This method is the main public interface to the ‘TextTestRunner’. This method takes a *note TestSuite: 6ce. or *note TestCase: 8ff. instance. A *note TestResult: abf. is created by calling *note _makeResult(): 308b. and the test(s) are run and the results printed to stdout. -- Function: unittest.main (module='__main__', defaultTest=None, argv=None, testRunner=None, testLoader=unittest.defaultTestLoader, exit=True, verbosity=1, failfast=None, catchbreak=None, buffer=None, warnings=None) A command-line program that loads a set of tests from `module' and runs them; this is primarily for making test modules conveniently executable. The simplest use for this function is to include the following line at the end of a test script: if __name__ == '__main__': unittest.main() You can run tests with more detailed information by passing in the verbosity argument: if __name__ == '__main__': unittest.main(verbosity=2) The `defaultTest' argument is either the name of a single test or an iterable of test names to run if no test names are specified via `argv'. If not specified or ‘None’ and no test names are provided via `argv', all tests found in `module' are run. The `argv' argument can be a list of options passed to the program, with the first element being the program name. If not specified or ‘None’, the values of *note sys.argv: bfb. are used. The `testRunner' argument can either be a test runner class or an already created instance of it. By default ‘main’ calls *note sys.exit(): ce2. with an exit code indicating success or failure of the tests run. The `testLoader' argument has to be a *note TestLoader: 782. instance, and defaults to *note defaultTestLoader: 306d. ‘main’ supports being used from the interactive interpreter by passing in the argument ‘exit=False’. This displays the result on standard output without calling *note sys.exit(): ce2.: >>> from unittest import main >>> main(module='test_module', exit=False) The `failfast', `catchbreak' and `buffer' parameters have the same effect as the same-name *note command-line options: 3037. The `warnings' argument specifies the *note warning filter: fe7. that should be used while running the tests. If it’s not specified, it will remain ‘None’ if a ‘-W’ option is passed to ‘python’ (see *note Warning control: fe6.), otherwise it will be set to ‘'default'’. Calling ‘main’ actually returns an instance of the ‘TestProgram’ class. This stores the result of the tests run as the ‘result’ attribute. Changed in version 3.1: The `exit' parameter was added. Changed in version 3.2: The `verbosity', `failfast', `catchbreak', `buffer' and `warnings' parameters were added. Changed in version 3.4: The `defaultTest' parameter was changed to also accept an iterable of test names. * Menu: * load_tests Protocol::  File: python.info, Node: load_tests Protocol, Up: Loading and running tests 5.26.4.14 load_tests Protocol ............................. New in version 3.2. Modules or packages can customize how tests are loaded from them during normal test runs or test discovery by implementing a function called ‘load_tests’. If a test module defines ‘load_tests’ it will be called by *note TestLoader.loadTestsFromModule(): 780. with the following arguments: load_tests(loader, standard_tests, pattern) where `pattern' is passed straight through from ‘loadTestsFromModule’. It defaults to ‘None’. It should return a *note TestSuite: 6ce. `loader' is the instance of *note TestLoader: 782. doing the loading. `standard_tests' are the tests that would be loaded by default from the module. It is common for test modules to only want to add or remove tests from the standard set of tests. The third argument is used when loading packages as part of test discovery. A typical ‘load_tests’ function that loads tests from a specific set of *note TestCase: 8ff. classes may look like: test_cases = (TestCase1, TestCase2, TestCase3) def load_tests(loader, tests, pattern): suite = TestSuite() for test_class in test_cases: tests = loader.loadTestsFromTestCase(test_class) suite.addTests(tests) return suite If discovery is started in a directory containing a package, either from the command line or by calling *note TestLoader.discover(): 904, then the package ‘__init__.py’ will be checked for ‘load_tests’. If that function does not exist, discovery will recurse into the package as though it were just another directory. Otherwise, discovery of the package’s tests will be left up to ‘load_tests’ which is called with the following arguments: load_tests(loader, standard_tests, pattern) This should return a *note TestSuite: 6ce. representing all the tests from the package. (‘standard_tests’ will only contain tests collected from ‘__init__.py’.) Because the pattern is passed into ‘load_tests’ the package is free to continue (and potentially modify) test discovery. A ‘do nothing’ ‘load_tests’ function for a test package would look like: def load_tests(loader, standard_tests, pattern): # top level directory cached on loader instance this_dir = os.path.dirname(__file__) package_tests = loader.discover(start_dir=this_dir, pattern=pattern) standard_tests.addTests(package_tests) return standard_tests Changed in version 3.5: Discovery no longer checks package names for matching `pattern' due to the impossibility of package names matching the default pattern.  File: python.info, Node: Class and Module Fixtures, Next: Signal Handling, Prev: Classes and functions, Up: unittest — Unit testing framework 5.26.4.15 Class and Module Fixtures ................................... Class and module level fixtures are implemented in *note TestSuite: 6ce. When the test suite encounters a test from a new class then ‘tearDownClass()’ from the previous class (if there is one) is called, followed by ‘setUpClass()’ from the new class. Similarly if a test is from a different module from the previous test then ‘tearDownModule’ from the previous module is run, followed by ‘setUpModule’ from the new module. After all the tests have run the final ‘tearDownClass’ and ‘tearDownModule’ are run. Note that shared fixtures do not play well with [potential] features like test parallelization and they break test isolation. They should be used with care. The default ordering of tests created by the unittest test loaders is to group all tests from the same modules and classes together. This will lead to ‘setUpClass’ / ‘setUpModule’ (etc) being called exactly once per class and module. If you randomize the order, so that tests from different modules and classes are adjacent to each other, then these shared fixture functions may be called multiple times in a single test run. Shared fixtures are not intended to work with suites with non-standard ordering. A ‘BaseTestSuite’ still exists for frameworks that don’t want to support shared fixtures. If there are any exceptions raised during one of the shared fixture functions the test is reported as an error. Because there is no corresponding test instance an ‘_ErrorHolder’ object (that has the same interface as a *note TestCase: 8ff.) is created to represent the error. If you are just using the standard unittest test runner then this detail doesn’t matter, but if you are a framework author it may be relevant. * Menu: * setUpClass and tearDownClass:: * setUpModule and tearDownModule::  File: python.info, Node: setUpClass and tearDownClass, Next: setUpModule and tearDownModule, Up: Class and Module Fixtures 5.26.4.16 setUpClass and tearDownClass ...................................... These must be implemented as class methods: import unittest class Test(unittest.TestCase): @classmethod def setUpClass(cls): cls._connection = createExpensiveConnectionObject() @classmethod def tearDownClass(cls): cls._connection.destroy() If you want the ‘setUpClass’ and ‘tearDownClass’ on base classes called then you must call up to them yourself. The implementations in *note TestCase: 8ff. are empty. If an exception is raised during a ‘setUpClass’ then the tests in the class are not run and the ‘tearDownClass’ is not run. Skipped classes will not have ‘setUpClass’ or ‘tearDownClass’ run. If the exception is a *note SkipTest: 903. exception then the class will be reported as having been skipped instead of as an error.  File: python.info, Node: setUpModule and tearDownModule, Prev: setUpClass and tearDownClass, Up: Class and Module Fixtures 5.26.4.17 setUpModule and tearDownModule ........................................ These should be implemented as functions: def setUpModule(): createConnection() def tearDownModule(): closeConnection() If an exception is raised in a ‘setUpModule’ then none of the tests in the module will be run and the ‘tearDownModule’ will not be run. If the exception is a *note SkipTest: 903. exception then the module will be reported as having been skipped instead of as an error. To add cleanup code that must be run even in the case of an exception, use ‘addModuleCleanup’: -- Function: unittest.addModuleCleanup (function, /, *args, **kwargs) Add a function to be called after ‘tearDownModule()’ to cleanup resources used during the test class. Functions will be called in reverse order to the order they are added (LIFO). They are called with any arguments and keyword arguments passed into *note addModuleCleanup(): 24a. when they are added. If ‘setUpModule()’ fails, meaning that ‘tearDownModule()’ is not called, then any cleanup functions added will still be called. New in version 3.8. -- Function: unittest.doModuleCleanups () This function is called unconditionally after ‘tearDownModule()’, or after ‘setUpModule()’ if ‘setUpModule()’ raises an exception. It is responsible for calling all the cleanup functions added by ‘addCleanupModule()’. If you need cleanup functions to be called `prior' to ‘tearDownModule()’ then you can call *note doModuleCleanups(): 308f. yourself. *note doModuleCleanups(): 308f. pops methods off the stack of cleanup functions one at a time, so it can be called at any time. New in version 3.8.  File: python.info, Node: Signal Handling, Prev: Class and Module Fixtures, Up: unittest — Unit testing framework 5.26.4.18 Signal Handling ......................... New in version 3.2. The *note -c/–catch: cc4. command-line option to unittest, along with the ‘catchbreak’ parameter to *note unittest.main(): 902, provide more friendly handling of control-C during a test run. With catch break behavior enabled control-C will allow the currently running test to complete, and the test run will then end and report all the results so far. A second control-c will raise a *note KeyboardInterrupt: 197. in the usual way. The control-c handling signal handler attempts to remain compatible with code or tests that install their own *note signal.SIGINT: 21c3. handler. If the ‘unittest’ handler is called but `isn’t' the installed *note signal.SIGINT: 21c3. handler, i.e. it has been replaced by the system under test and delegated to, then it calls the default handler. This will normally be the expected behavior by code that replaces an installed handler and delegates to it. For individual tests that need ‘unittest’ control-c handling disabled the *note removeHandler(): cc5. decorator can be used. There are a few utility functions for framework authors to enable control-c handling functionality within test frameworks. -- Function: unittest.installHandler () Install the control-c handler. When a *note signal.SIGINT: 21c3. is received (usually in response to the user pressing control-c) all registered results have *note stop(): 307a. called. -- Function: unittest.registerResult (result) Register a *note TestResult: abf. object for control-c handling. Registering a result stores a weak reference to it, so it doesn’t prevent the result from being garbage collected. Registering a *note TestResult: abf. object has no side-effects if control-c handling is not enabled, so test frameworks can unconditionally register all results they create independently of whether or not handling is enabled. -- Function: unittest.removeResult (result) Remove a registered result. Once a result has been removed then *note stop(): 307a. will no longer be called on that result object in response to a control-c. -- Function: unittest.removeHandler (function=None) When called without arguments this function removes the control-c handler if it has been installed. This function can also be used as a test decorator to temporarily remove the handler while the test is being executed: @unittest.removeHandler def test_signal_handling(self): ...  File: python.info, Node: unittest mock — mock object library, Next: unittest mock — getting started, Prev: unittest — Unit testing framework, Up: Development Tools 5.26.5 ‘unittest.mock’ — mock object library -------------------------------------------- New in version 3.3. `Source code:' Lib/unittest/mock.py(1) __________________________________________________________________ *note unittest.mock: 11c. is a library for testing in Python. It allows you to replace parts of your system under test with mock objects and make assertions about how they have been used. *note unittest.mock: 11c. provides a core *note Mock: 249. class removing the need to create a host of stubs throughout your test suite. After performing an action, you can make assertions about which methods / attributes were used and arguments they were called with. You can also specify return values and set needed attributes in the normal way. Additionally, mock provides a *note patch(): 788. decorator that handles patching module and class level attributes within the scope of a test, along with *note sentinel: 40a. for creating unique objects. See the *note quick guide: 3095. for some examples of how to use *note Mock: 249, *note MagicMock: 785. and *note patch(): 788. Mock is very easy to use and is designed for use with *note unittest: 11b. Mock is based on the ‘action -> assertion’ pattern instead of ‘record -> replay’ used by many mocking frameworks. There is a backport of *note unittest.mock: 11c. for earlier versions of Python, available as mock on PyPI(2). * Menu: * Quick Guide:: * The Mock Class:: * The patchers:: * MagicMock and magic method support:: * Helpers:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/unittest/mock.py (2) https://pypi.org/project/mock  File: python.info, Node: Quick Guide, Next: The Mock Class, Up: unittest mock — mock object library 5.26.5.1 Quick Guide .................... *note Mock: 249. and *note MagicMock: 785. objects create all attributes and methods as you access them and store details of how they have been used. You can configure them, to specify return values or limit what attributes are available, and then make assertions about how they have been used: >>> from unittest.mock import MagicMock >>> thing = ProductionClass() >>> thing.method = MagicMock(return_value=3) >>> thing.method(3, 4, 5, key='value') 3 >>> thing.method.assert_called_with(3, 4, 5, key='value') ‘side_effect’ allows you to perform side effects, including raising an exception when a mock is called: >>> mock = Mock(side_effect=KeyError('foo')) >>> mock() Traceback (most recent call last): ... KeyError: 'foo' >>> values = {'a': 1, 'b': 2, 'c': 3} >>> def side_effect(arg): ... return values[arg] ... >>> mock.side_effect = side_effect >>> mock('a'), mock('b'), mock('c') (1, 2, 3) >>> mock.side_effect = [5, 4, 3, 2, 1] >>> mock(), mock(), mock() (5, 4, 3) Mock has many other ways you can configure it and control its behaviour. For example the `spec' argument configures the mock to take its specification from another object. Attempting to access attributes or methods on the mock that don’t exist on the spec will fail with an *note AttributeError: 39b. The *note patch(): 788. decorator / context manager makes it easy to mock classes or objects in a module under test. The object you specify will be replaced with a mock (or other object) during the test and restored when the test ends: >>> from unittest.mock import patch >>> @patch('module.ClassName2') ... @patch('module.ClassName1') ... def test(MockClass1, MockClass2): ... module.ClassName1() ... module.ClassName2() ... assert MockClass1 is module.ClassName1 ... assert MockClass2 is module.ClassName2 ... assert MockClass1.called ... assert MockClass2.called ... >>> test() Note: When you nest patch decorators the mocks are passed in to the decorated function in the same order they applied (the normal `Python' order that decorators are applied). This means from the bottom up, so in the example above the mock for ‘module.ClassName1’ is passed in first. With *note patch(): 788. it matters that you patch objects in the namespace where they are looked up. This is normally straightforward, but for a quick guide read *note where to patch: 3096. As well as a decorator *note patch(): 788. can be used as a context manager in a with statement: >>> with patch.object(ProductionClass, 'method', return_value=None) as mock_method: ... thing = ProductionClass() ... thing.method(1, 2, 3) ... >>> mock_method.assert_called_once_with(1, 2, 3) There is also *note patch.dict(): 3097. for setting values in a dictionary just during a scope and restoring the dictionary to its original state when the test ends: >>> foo = {'key': 'value'} >>> original = foo.copy() >>> with patch.dict(foo, {'newkey': 'newvalue'}, clear=True): ... assert foo == {'newkey': 'newvalue'} ... >>> assert foo == original Mock supports the mocking of Python *note magic methods: 3098. The easiest way of using magic methods is with the *note MagicMock: 785. class. It allows you to do things like: >>> mock = MagicMock() >>> mock.__str__.return_value = 'foobarbaz' >>> str(mock) 'foobarbaz' >>> mock.__str__.assert_called_with() Mock allows you to assign functions (or other Mock instances) to magic methods and they will be called appropriately. The *note MagicMock: 785. class is just a Mock variant that has all of the magic methods pre-created for you (well, all the useful ones anyway). The following is an example of using magic methods with the ordinary Mock class: >>> mock = Mock() >>> mock.__str__ = Mock(return_value='wheeeeee') >>> str(mock) 'wheeeeee' For ensuring that the mock objects in your tests have the same api as the objects they are replacing, you can use *note auto-speccing: 3099. Auto-speccing can be done through the `autospec' argument to patch, or the *note create_autospec(): 309a. function. Auto-speccing creates mock objects that have the same attributes and methods as the objects they are replacing, and any functions and methods (including constructors) have the same call signature as the real object. This ensures that your mocks will fail in the same way as your production code if they are used incorrectly: >>> from unittest.mock import create_autospec >>> def function(a, b, c): ... pass ... >>> mock_function = create_autospec(function, return_value='fishy') >>> mock_function(1, 2, 3) 'fishy' >>> mock_function.assert_called_once_with(1, 2, 3) >>> mock_function('wrong arguments') Traceback (most recent call last): ... TypeError: <lambda>() takes exactly 3 arguments (1 given) *note create_autospec(): 309a. can also be used on classes, where it copies the signature of the ‘__init__’ method, and on callable objects where it copies the signature of the ‘__call__’ method.  File: python.info, Node: The Mock Class, Next: The patchers, Prev: Quick Guide, Up: unittest mock — mock object library 5.26.5.2 The Mock Class ....................... *note Mock: 249. is a flexible mock object intended to replace the use of stubs and test doubles throughout your code. Mocks are callable and create attributes as new mocks when you access them (1). Accessing the same attribute will always return the same mock. Mocks record how you use them, allowing you to make assertions about what your code has done to them. *note MagicMock: 785. is a subclass of *note Mock: 249. with all the magic methods pre-created and ready to use. There are also non-callable variants, useful when you are mocking out objects that aren’t callable: *note NonCallableMock: 309c. and *note NonCallableMagicMock: 309d. The *note patch(): 788. decorators makes it easy to temporarily replace classes in a particular module with a *note Mock: 249. object. By default *note patch(): 788. will create a *note MagicMock: 785. for you. You can specify an alternative class of *note Mock: 249. using the `new_callable' argument to *note patch(): 788. -- Class: unittest.mock.Mock (spec=None, side_effect=None, return_value=DEFAULT, wraps=None, name=None, spec_set=None, unsafe=False, **kwargs) Create a new *note Mock: 249. object. *note Mock: 249. takes several optional arguments that specify the behaviour of the Mock object: * `spec': This can be either a list of strings or an existing object (a class or instance) that acts as the specification for the mock object. If you pass in an object then a list of strings is formed by calling dir on the object (excluding unsupported magic attributes and methods). Accessing any attribute not in this list will raise an *note AttributeError: 39b. If `spec' is an object (rather than a list of strings) then *note __class__: e0a. returns the class of the spec object. This allows mocks to pass *note isinstance(): 44f. tests. * `spec_set': A stricter variant of `spec'. If used, attempting to `set' or get an attribute on the mock that isn’t on the object passed as `spec_set' will raise an *note AttributeError: 39b. * `side_effect': A function to be called whenever the Mock is called. See the *note side_effect: 309e. attribute. Useful for raising exceptions or dynamically changing return values. The function is called with the same arguments as the mock, and unless it returns *note DEFAULT: 309f, the return value of this function is used as the return value. Alternatively `side_effect' can be an exception class or instance. In this case the exception will be raised when the mock is called. If `side_effect' is an iterable then each call to the mock will return the next value from the iterable. A `side_effect' can be cleared by setting it to ‘None’. * `return_value': The value returned when the mock is called. By default this is a new Mock (created on first access). See the *note return_value: 30a0. attribute. * `unsafe': By default if any attribute starts with `assert' or `assret' will raise an *note AttributeError: 39b. Passing ‘unsafe=True’ will allow access to these attributes. New in version 3.5. * `wraps': Item for the mock object to wrap. If `wraps' is not ‘None’ then calling the Mock will pass the call through to the wrapped object (returning the real result). Attribute access on the mock will return a Mock object that wraps the corresponding attribute of the wrapped object (so attempting to access an attribute that doesn’t exist will raise an *note AttributeError: 39b.). If the mock has an explicit `return_value' set then calls are not passed to the wrapped object and the `return_value' is returned instead. * `name': If the mock has a name then it will be used in the repr of the mock. This can be useful for debugging. The name is propagated to child mocks. Mocks can also be called with arbitrary keyword arguments. These will be used to set attributes on the mock after it is created. See the *note configure_mock(): 30a1. method for details. -- Method: assert_called () Assert that the mock was called at least once. >>> mock = Mock() >>> mock.method() <Mock name='mock.method()' id='...'> >>> mock.method.assert_called() New in version 3.6. -- Method: assert_called_once () Assert that the mock was called exactly once. >>> mock = Mock() >>> mock.method() <Mock name='mock.method()' id='...'> >>> mock.method.assert_called_once() >>> mock.method() <Mock name='mock.method()' id='...'> >>> mock.method.assert_called_once() Traceback (most recent call last): ... AssertionError: Expected 'method' to have been called once. Called 2 times. New in version 3.6. -- Method: assert_called_with (*args, **kwargs) This method is a convenient way of asserting that the last call has been made in a particular way: >>> mock = Mock() >>> mock.method(1, 2, 3, test='wow') <Mock name='mock.method()' id='...'> >>> mock.method.assert_called_with(1, 2, 3, test='wow') -- Method: assert_called_once_with (*args, **kwargs) Assert that the mock was called exactly once and that that call was with the specified arguments. >>> mock = Mock(return_value=None) >>> mock('foo', bar='baz') >>> mock.assert_called_once_with('foo', bar='baz') >>> mock('other', bar='values') >>> mock.assert_called_once_with('other', bar='values') Traceback (most recent call last): ... AssertionError: Expected 'mock' to be called once. Called 2 times. -- Method: assert_any_call (*args, **kwargs) assert the mock has been called with the specified arguments. The assert passes if the mock has `ever' been called, unlike *note assert_called_with(): 30a2. and *note assert_called_once_with(): 30a3. that only pass if the call is the most recent one, and in the case of *note assert_called_once_with(): 30a3. it must also be the only call. >>> mock = Mock(return_value=None) >>> mock(1, 2, arg='thing') >>> mock('some', 'thing', 'else') >>> mock.assert_any_call(1, 2, arg='thing') -- Method: assert_has_calls (calls, any_order=False) assert the mock has been called with the specified calls. The *note mock_calls: 30a6. list is checked for the calls. If `any_order' is false then the calls must be sequential. There can be extra calls before or after the specified calls. If `any_order' is true then the calls can be in any order, but they must all appear in *note mock_calls: 30a6. >>> mock = Mock(return_value=None) >>> mock(1) >>> mock(2) >>> mock(3) >>> mock(4) >>> calls = [call(2), call(3)] >>> mock.assert_has_calls(calls) >>> calls = [call(4), call(2), call(3)] >>> mock.assert_has_calls(calls, any_order=True) -- Method: assert_not_called () Assert the mock was never called. >>> m = Mock() >>> m.hello.assert_not_called() >>> obj = m.hello() >>> m.hello.assert_not_called() Traceback (most recent call last): ... AssertionError: Expected 'hello' to not have been called. Called 1 times. New in version 3.5. -- Method: reset_mock (*, return_value=False, side_effect=False) The reset_mock method resets all the call attributes on a mock object: >>> mock = Mock(return_value=None) >>> mock('hello') >>> mock.called True >>> mock.reset_mock() >>> mock.called False Changed in version 3.6: Added two keyword only argument to the reset_mock function. This can be useful where you want to make a series of assertions that reuse the same object. Note that *note reset_mock(): 5aa. `doesn’t' clear the return value, *note side_effect: 309e. or any child attributes you have set using normal assignment by default. In case you want to reset `return_value' or *note side_effect: 309e, then pass the corresponding parameter as ‘True’. Child mocks and the return value mock (if any) are reset as well. Note: `return_value', and *note side_effect: 309e. are keyword only argument. -- Method: mock_add_spec (spec, spec_set=False) Add a spec to a mock. `spec' can either be an object or a list of strings. Only attributes on the `spec' can be fetched as attributes from the mock. If `spec_set' is true then only attributes on the spec can be set. -- Method: attach_mock (mock, attribute) Attach a mock as an attribute of this one, replacing its name and parent. Calls to the attached mock will be recorded in the *note method_calls: 30a9. and *note mock_calls: 30a6. attributes of this one. -- Method: configure_mock (**kwargs) Set attributes on the mock through keyword arguments. Attributes plus return values and side effects can be set on child mocks using standard dot notation and unpacking a dictionary in the method call: >>> mock = Mock() >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError} >>> mock.configure_mock(**attrs) >>> mock.method() 3 >>> mock.other() Traceback (most recent call last): ... KeyError The same thing can be achieved in the constructor call to mocks: >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError} >>> mock = Mock(some_attribute='eggs', **attrs) >>> mock.some_attribute 'eggs' >>> mock.method() 3 >>> mock.other() Traceback (most recent call last): ... KeyError *note configure_mock(): 30a1. exists to make it easier to do configuration after the mock has been created. -- Method: __dir__ () *note Mock: 249. objects limit the results of ‘dir(some_mock)’ to useful results. For mocks with a `spec' this includes all the permitted attributes for the mock. See *note FILTER_DIR: 30ab. for what this filtering does, and how to switch it off. -- Method: _get_child_mock (**kw) Create the child mocks for attributes and return value. By default child mocks will be the same type as the parent. Subclasses of Mock may want to override this to customize the way child mocks are made. For non-callable mocks the callable variant will be used (rather than any custom subclass). -- Attribute: called A boolean representing whether or not the mock object has been called: >>> mock = Mock(return_value=None) >>> mock.called False >>> mock() >>> mock.called True -- Attribute: call_count An integer telling you how many times the mock object has been called: >>> mock = Mock(return_value=None) >>> mock.call_count 0 >>> mock() >>> mock() >>> mock.call_count 2 -- Attribute: return_value Set this to configure the value returned by calling the mock: >>> mock = Mock() >>> mock.return_value = 'fish' >>> mock() 'fish' The default return value is a mock object and you can configure it in the normal way: >>> mock = Mock() >>> mock.return_value.attribute = sentinel.Attribute >>> mock.return_value() <Mock name='mock()()' id='...'> >>> mock.return_value.assert_called_with() *note return_value: 30a0. can also be set in the constructor: >>> mock = Mock(return_value=3) >>> mock.return_value 3 >>> mock() 3 -- Attribute: side_effect This can either be a function to be called when the mock is called, an iterable or an exception (class or instance) to be raised. If you pass in a function it will be called with same arguments as the mock and unless the function returns the *note DEFAULT: 309f. singleton the call to the mock will then return whatever the function returns. If the function returns *note DEFAULT: 309f. then the mock will return its normal value (from the *note return_value: 30a0.). If you pass in an iterable, it is used to retrieve an iterator which must yield a value on every call. This value can either be an exception instance to be raised, or a value to be returned from the call to the mock (*note DEFAULT: 309f. handling is identical to the function case). An example of a mock that raises an exception (to test exception handling of an API): >>> mock = Mock() >>> mock.side_effect = Exception('Boom!') >>> mock() Traceback (most recent call last): ... Exception: Boom! Using *note side_effect: 309e. to return a sequence of values: >>> mock = Mock() >>> mock.side_effect = [3, 2, 1] >>> mock(), mock(), mock() (3, 2, 1) Using a callable: >>> mock = Mock(return_value=3) >>> def side_effect(*args, **kwargs): ... return DEFAULT ... >>> mock.side_effect = side_effect >>> mock() 3 *note side_effect: 309e. can be set in the constructor. Here’s an example that adds one to the value the mock is called with and returns it: >>> side_effect = lambda value: value + 1 >>> mock = Mock(side_effect=side_effect) >>> mock(3) 4 >>> mock(-8) -7 Setting *note side_effect: 309e. to ‘None’ clears it: >>> m = Mock(side_effect=KeyError, return_value=3) >>> m() Traceback (most recent call last): ... KeyError >>> m.side_effect = None >>> m() 3 -- Attribute: call_args This is either ‘None’ (if the mock hasn’t been called), or the arguments that the mock was last called with. This will be in the form of a tuple: the first member, which can also be accessed through the ‘args’ property, is any ordered arguments the mock was called with (or an empty tuple) and the second member, which can also be accessed through the ‘kwargs’ property, is any keyword arguments (or an empty dictionary). >>> mock = Mock(return_value=None) >>> print(mock.call_args) None >>> mock() >>> mock.call_args call() >>> mock.call_args == () True >>> mock(3, 4) >>> mock.call_args call(3, 4) >>> mock.call_args == ((3, 4),) True >>> mock.call_args.args (3, 4) >>> mock.call_args.kwargs {} >>> mock(3, 4, 5, key='fish', next='w00t!') >>> mock.call_args call(3, 4, 5, key='fish', next='w00t!') >>> mock.call_args.args (3, 4, 5) >>> mock.call_args.kwargs {'key': 'fish', 'next': 'w00t!'} *note call_args: 30af, along with members of the lists *note call_args_list: 30b0, *note method_calls: 30a9. and *note mock_calls: 30a6. are *note call: 30b1. objects. These are tuples, so they can be unpacked to get at the individual arguments and make more complex assertions. See *note calls as tuples: 30b2. Changed in version 3.8: Added ‘args’ and ‘kwargs’ properties. -- Attribute: call_args_list This is a list of all the calls made to the mock object in sequence (so the length of the list is the number of times it has been called). Before any calls have been made it is an empty list. The *note call: 30b1. object can be used for conveniently constructing lists of calls to compare with *note call_args_list: 30b0. >>> mock = Mock(return_value=None) >>> mock() >>> mock(3, 4) >>> mock(key='fish', next='w00t!') >>> mock.call_args_list [call(), call(3, 4), call(key='fish', next='w00t!')] >>> expected = [(), ((3, 4),), ({'key': 'fish', 'next': 'w00t!'},)] >>> mock.call_args_list == expected True Members of *note call_args_list: 30b0. are *note call: 30b1. objects. These can be unpacked as tuples to get at the individual arguments. See *note calls as tuples: 30b2. -- Attribute: method_calls As well as tracking calls to themselves, mocks also track calls to methods and attributes, and `their' methods and attributes: >>> mock = Mock() >>> mock.method() <Mock name='mock.method()' id='...'> >>> mock.property.method.attribute() <Mock name='mock.property.method.attribute()' id='...'> >>> mock.method_calls [call.method(), call.property.method.attribute()] Members of *note method_calls: 30a9. are *note call: 30b1. objects. These can be unpacked as tuples to get at the individual arguments. See *note calls as tuples: 30b2. -- Attribute: mock_calls *note mock_calls: 30a6. records `all' calls to the mock object, its methods, magic methods `and' return value mocks. >>> mock = MagicMock() >>> result = mock(1, 2, 3) >>> mock.first(a=3) <MagicMock name='mock.first()' id='...'> >>> mock.second() <MagicMock name='mock.second()' id='...'> >>> int(mock) 1 >>> result(1) <MagicMock name='mock()()' id='...'> >>> expected = [call(1, 2, 3), call.first(a=3), call.second(), ... call.__int__(), call()(1)] >>> mock.mock_calls == expected True Members of *note mock_calls: 30a6. are *note call: 30b1. objects. These can be unpacked as tuples to get at the individual arguments. See *note calls as tuples: 30b2. Note: The way *note mock_calls: 30a6. are recorded means that where nested calls are made, the parameters of ancestor calls are not recorded and so will always compare equal: >>> mock = MagicMock() >>> mock.top(a=3).bottom() <MagicMock name='mock.top().bottom()' id='...'> >>> mock.mock_calls [call.top(a=3), call.top().bottom()] >>> mock.mock_calls[-1] == call.top(a=-1).bottom() True -- Attribute: __class__ Normally the *note __class__: 30b3. attribute of an object will return its type. For a mock object with a ‘spec’, ‘__class__’ returns the spec class instead. This allows mock objects to pass *note isinstance(): 44f. tests for the object they are replacing / masquerading as: >>> mock = Mock(spec=3) >>> isinstance(mock, int) True *note __class__: 30b3. is assignable to, this allows a mock to pass an *note isinstance(): 44f. check without forcing you to use a spec: >>> mock = Mock() >>> mock.__class__ = dict >>> isinstance(mock, dict) True -- Class: unittest.mock.NonCallableMock (spec=None, wraps=None, name=None, spec_set=None, **kwargs) A non-callable version of *note Mock: 249. The constructor parameters have the same meaning of *note Mock: 249, with the exception of `return_value' and `side_effect' which have no meaning on a non-callable mock. Mock objects that use a class or an instance as a ‘spec’ or ‘spec_set’ are able to pass *note isinstance(): 44f. tests: >>> mock = Mock(spec=SomeClass) >>> isinstance(mock, SomeClass) True >>> mock = Mock(spec_set=SomeClass()) >>> isinstance(mock, SomeClass) True The *note Mock: 249. classes have support for mocking magic methods. See *note magic methods: 3098. for the full details. The mock classes and the *note patch(): 788. decorators all take arbitrary keyword arguments for configuration. For the *note patch(): 788. decorators the keywords are passed to the constructor of the mock being created. The keyword arguments are for configuring attributes of the mock: >>> m = MagicMock(attribute=3, other='fish') >>> m.attribute 3 >>> m.other 'fish' The return value and side effect of child mocks can be set in the same way, using dotted notation. As you can’t use dotted names directly in a call you have to create a dictionary and unpack it using ‘**’: >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError} >>> mock = Mock(some_attribute='eggs', **attrs) >>> mock.some_attribute 'eggs' >>> mock.method() 3 >>> mock.other() Traceback (most recent call last): ... KeyError A callable mock which was created with a `spec' (or a `spec_set') will introspect the specification object’s signature when matching calls to the mock. Therefore, it can match the actual call’s arguments regardless of whether they were passed positionally or by name: >>> def f(a, b, c): pass ... >>> mock = Mock(spec=f) >>> mock(1, 2, c=3) <Mock name='mock()' id='140161580456576'> >>> mock.assert_called_with(1, 2, 3) >>> mock.assert_called_with(a=1, b=2, c=3) This applies to *note assert_called_with(): 30a2, *note assert_called_once_with(): 30a3, *note assert_has_calls(): 30a5. and *note assert_any_call(): 30a4. When *note Autospeccing: 3099, it will also apply to method calls on the mock object. Changed in version 3.4: Added signature introspection on specced and autospecced mock objects. -- Class: unittest.mock.PropertyMock (*args, **kwargs) A mock intended to be used as a property, or other descriptor, on a class. *note PropertyMock: 30b4. provides *note __get__(): 10dd. and *note __set__(): 10e1. methods so you can specify a return value when it is fetched. Fetching a *note PropertyMock: 30b4. instance from an object calls the mock, with no args. Setting it calls the mock with the value being set. >>> class Foo: ... @property ... def foo(self): ... return 'something' ... @foo.setter ... def foo(self, value): ... pass ... >>> with patch('__main__.Foo.foo', new_callable=PropertyMock) as mock_foo: ... mock_foo.return_value = 'mockity-mock' ... this_foo = Foo() ... print(this_foo.foo) ... this_foo.foo = 6 ... mockity-mock >>> mock_foo.mock_calls [call(), call(6)] Because of the way mock attributes are stored you can’t directly attach a *note PropertyMock: 30b4. to a mock object. Instead you can attach it to the mock type object: >>> m = MagicMock() >>> p = PropertyMock(return_value=3) >>> type(m).foo = p >>> m.foo 3 >>> p.assert_called_once_with() -- Class: unittest.mock.AsyncMock (spec=None, side_effect=None, return_value=DEFAULT, wraps=None, name=None, spec_set=None, unsafe=False, **kwargs) An asynchronous version of *note Mock: 249. The *note AsyncMock: 248. object will behave so the object is recognized as an async function, and the result of a call is an awaitable. >>> mock = AsyncMock() >>> asyncio.iscoroutinefunction(mock) True >>> inspect.isawaitable(mock()) True The result of ‘mock()’ is an async function which will have the outcome of ‘side_effect’ or ‘return_value’ after it has been awaited: - if ‘side_effect’ is a function, the async function will return the result of that function, - if ‘side_effect’ is an exception, the async function will raise the exception, - if ‘side_effect’ is an iterable, the async function will return the next value of the iterable, however, if the sequence of result is exhausted, ‘StopAsyncIteration’ is raised immediately, - if ‘side_effect’ is not defined, the async function will return the value defined by ‘return_value’, hence, by default, the async function returns a new *note AsyncMock: 248. object. Setting the `spec' of a *note Mock: 249. or *note MagicMock: 785. to an async function will result in a coroutine object being returned after calling. >>> async def async_func(): pass ... >>> mock = MagicMock(async_func) >>> mock <MagicMock spec='function' id='...'> >>> mock() <coroutine object AsyncMockMixin._mock_call at ...> Setting the `spec' of a *note Mock: 249, *note MagicMock: 785, or *note AsyncMock: 248. to a class with asynchronous and synchronous functions will automatically detect the synchronous functions and set them as *note MagicMock: 785. (if the parent mock is *note AsyncMock: 248. or *note MagicMock: 785.) or *note Mock: 249. (if the parent mock is *note Mock: 249.). All asynchronous functions will be *note AsyncMock: 248. >>> class ExampleClass: ... def sync_foo(): ... pass ... async def async_foo(): ... pass ... >>> a_mock = AsyncMock(ExampleClass) >>> a_mock.sync_foo <MagicMock name='mock.sync_foo' id='...'> >>> a_mock.async_foo <AsyncMock name='mock.async_foo' id='...'> >>> mock = Mock(ExampleClass) >>> mock.sync_foo <Mock name='mock.sync_foo' id='...'> >>> mock.async_foo <AsyncMock name='mock.async_foo' id='...'> New in version 3.8. -- Method: assert_awaited () Assert that the mock was awaited at least once. Note that this is separate from the object having been called, the ‘await’ keyword must be used: >>> mock = AsyncMock() >>> async def main(coroutine_mock): ... await coroutine_mock ... >>> coroutine_mock = mock() >>> mock.called True >>> mock.assert_awaited() Traceback (most recent call last): ... AssertionError: Expected mock to have been awaited. >>> asyncio.run(main(coroutine_mock)) >>> mock.assert_awaited() -- Method: assert_awaited_once () Assert that the mock was awaited exactly once. >>> mock = AsyncMock() >>> async def main(): ... await mock() ... >>> asyncio.run(main()) >>> mock.assert_awaited_once() >>> asyncio.run(main()) >>> mock.method.assert_awaited_once() Traceback (most recent call last): ... AssertionError: Expected mock to have been awaited once. Awaited 2 times. -- Method: assert_awaited_with (*args, **kwargs) Assert that the last await was with the specified arguments. >>> mock = AsyncMock() >>> async def main(*args, **kwargs): ... await mock(*args, **kwargs) ... >>> asyncio.run(main('foo', bar='bar')) >>> mock.assert_awaited_with('foo', bar='bar') >>> mock.assert_awaited_with('other') Traceback (most recent call last): ... AssertionError: expected call not found. Expected: mock('other') Actual: mock('foo', bar='bar') -- Method: assert_awaited_once_with (*args, **kwargs) Assert that the mock was awaited exactly once and with the specified arguments. >>> mock = AsyncMock() >>> async def main(*args, **kwargs): ... await mock(*args, **kwargs) ... >>> asyncio.run(main('foo', bar='bar')) >>> mock.assert_awaited_once_with('foo', bar='bar') >>> asyncio.run(main('foo', bar='bar')) >>> mock.assert_awaited_once_with('foo', bar='bar') Traceback (most recent call last): ... AssertionError: Expected mock to have been awaited once. Awaited 2 times. -- Method: assert_any_await (*args, **kwargs) Assert the mock has ever been awaited with the specified arguments. >>> mock = AsyncMock() >>> async def main(*args, **kwargs): ... await mock(*args, **kwargs) ... >>> asyncio.run(main('foo', bar='bar')) >>> asyncio.run(main('hello')) >>> mock.assert_any_await('foo', bar='bar') >>> mock.assert_any_await('other') Traceback (most recent call last): ... AssertionError: mock('other') await not found -- Method: assert_has_awaits (calls, any_order=False) Assert the mock has been awaited with the specified calls. The *note await_args_list: 30bb. list is checked for the awaits. If `any_order' is false then the awaits must be sequential. There can be extra calls before or after the specified awaits. If `any_order' is true then the awaits can be in any order, but they must all appear in *note await_args_list: 30bb. >>> mock = AsyncMock() >>> async def main(*args, **kwargs): ... await mock(*args, **kwargs) ... >>> calls = [call("foo"), call("bar")] >>> mock.assert_has_awaits(calls) Traceback (most recent call last): ... AssertionError: Awaits not found. Expected: [call('foo'), call('bar')] Actual: [] >>> asyncio.run(main('foo')) >>> asyncio.run(main('bar')) >>> mock.assert_has_awaits(calls) -- Method: assert_not_awaited () Assert that the mock was never awaited. >>> mock = AsyncMock() >>> mock.assert_not_awaited() -- Method: reset_mock (*args, **kwargs) See *note Mock.reset_mock(): 5aa. Also sets *note await_count: 30be. to 0, *note await_args: 30bf. to None, and clears the *note await_args_list: 30bb. -- Attribute: await_count An integer keeping track of how many times the mock object has been awaited. >>> mock = AsyncMock() >>> async def main(): ... await mock() ... >>> asyncio.run(main()) >>> mock.await_count 1 >>> asyncio.run(main()) >>> mock.await_count 2 -- Attribute: await_args This is either ‘None’ (if the mock hasn’t been awaited), or the arguments that the mock was last awaited with. Functions the same as *note Mock.call_args: 30af. >>> mock = AsyncMock() >>> async def main(*args): ... await mock(*args) ... >>> mock.await_args >>> asyncio.run(main('foo')) >>> mock.await_args call('foo') >>> asyncio.run(main('bar')) >>> mock.await_args call('bar') -- Attribute: await_args_list This is a list of all the awaits made to the mock object in sequence (so the length of the list is the number of times it has been awaited). Before any awaits have been made it is an empty list. >>> mock = AsyncMock() >>> async def main(*args): ... await mock(*args) ... >>> mock.await_args_list [] >>> asyncio.run(main('foo')) >>> mock.await_args_list [call('foo')] >>> asyncio.run(main('bar')) >>> mock.await_args_list [call('foo'), call('bar')] * Menu: * Calling:: * Deleting Attributes:: * Mock names and the name attribute:: * Attaching Mocks as Attributes:: ---------- Footnotes ---------- (1) (1) The only exceptions are magic methods and attributes (those that have leading and trailing double underscores). Mock doesn’t create these but instead raises an *note AttributeError: 39b. This is because the interpreter will often implicitly request these methods, and gets `very' confused to get a new Mock object when it expects a magic method. If you need magic method support see *note magic methods: 3098.  File: python.info, Node: Calling, Next: Deleting Attributes, Up: The Mock Class 5.26.5.3 Calling ................ Mock objects are callable. The call will return the value set as the *note return_value: 30a0. attribute. The default return value is a new Mock object; it is created the first time the return value is accessed (either explicitly or by calling the Mock) - but it is stored and the same one returned each time. Calls made to the object will be recorded in the attributes like *note call_args: 30af. and *note call_args_list: 30b0. If *note side_effect: 309e. is set then it will be called after the call has been recorded, so if ‘side_effect’ raises an exception the call is still recorded. The simplest way to make a mock raise an exception when called is to make *note side_effect: 309e. an exception class or instance: >>> m = MagicMock(side_effect=IndexError) >>> m(1, 2, 3) Traceback (most recent call last): ... IndexError >>> m.mock_calls [call(1, 2, 3)] >>> m.side_effect = KeyError('Bang!') >>> m('two', 'three', 'four') Traceback (most recent call last): ... KeyError: 'Bang!' >>> m.mock_calls [call(1, 2, 3), call('two', 'three', 'four')] If ‘side_effect’ is a function then whatever that function returns is what calls to the mock return. The ‘side_effect’ function is called with the same arguments as the mock. This allows you to vary the return value of the call dynamically, based on the input: >>> def side_effect(value): ... return value + 1 ... >>> m = MagicMock(side_effect=side_effect) >>> m(1) 2 >>> m(2) 3 >>> m.mock_calls [call(1), call(2)] If you want the mock to still return the default return value (a new mock), or any set return value, then there are two ways of doing this. Either return ‘mock.return_value’ from inside ‘side_effect’, or return *note DEFAULT: 309f.: >>> m = MagicMock() >>> def side_effect(*args, **kwargs): ... return m.return_value ... >>> m.side_effect = side_effect >>> m.return_value = 3 >>> m() 3 >>> def side_effect(*args, **kwargs): ... return DEFAULT ... >>> m.side_effect = side_effect >>> m() 3 To remove a ‘side_effect’, and return to the default behaviour, set the ‘side_effect’ to ‘None’: >>> m = MagicMock(return_value=6) >>> def side_effect(*args, **kwargs): ... return 3 ... >>> m.side_effect = side_effect >>> m() 3 >>> m.side_effect = None >>> m() 6 The ‘side_effect’ can also be any iterable object. Repeated calls to the mock will return values from the iterable (until the iterable is exhausted and a *note StopIteration: 486. is raised): >>> m = MagicMock(side_effect=[1, 2, 3]) >>> m() 1 >>> m() 2 >>> m() 3 >>> m() Traceback (most recent call last): ... StopIteration If any members of the iterable are exceptions they will be raised instead of returned: >>> iterable = (33, ValueError, 66) >>> m = MagicMock(side_effect=iterable) >>> m() 33 >>> m() Traceback (most recent call last): ... ValueError >>> m() 66  File: python.info, Node: Deleting Attributes, Next: Mock names and the name attribute, Prev: Calling, Up: The Mock Class 5.26.5.4 Deleting Attributes ............................ Mock objects create attributes on demand. This allows them to pretend to be objects of any type. You may want a mock object to return ‘False’ to a *note hasattr(): 447. call, or raise an *note AttributeError: 39b. when an attribute is fetched. You can do this by providing an object as a ‘spec’ for a mock, but that isn’t always convenient. You “block” attributes by deleting them. Once deleted, accessing an attribute will raise an *note AttributeError: 39b. >>> mock = MagicMock() >>> hasattr(mock, 'm') True >>> del mock.m >>> hasattr(mock, 'm') False >>> del mock.f >>> mock.f Traceback (most recent call last): ... AttributeError: f  File: python.info, Node: Mock names and the name attribute, Next: Attaching Mocks as Attributes, Prev: Deleting Attributes, Up: The Mock Class 5.26.5.5 Mock names and the name attribute .......................................... Since “name” is an argument to the *note Mock: 249. constructor, if you want your mock object to have a “name” attribute you can’t just pass it in at creation time. There are two alternatives. One option is to use *note configure_mock(): 30a1.: >>> mock = MagicMock() >>> mock.configure_mock(name='my_name') >>> mock.name 'my_name' A simpler option is to simply set the “name” attribute after mock creation: >>> mock = MagicMock() >>> mock.name = "foo"  File: python.info, Node: Attaching Mocks as Attributes, Prev: Mock names and the name attribute, Up: The Mock Class 5.26.5.6 Attaching Mocks as Attributes ...................................... When you attach a mock as an attribute of another mock (or as the return value) it becomes a “child” of that mock. Calls to the child are recorded in the *note method_calls: 30a9. and *note mock_calls: 30a6. attributes of the parent. This is useful for configuring child mocks and then attaching them to the parent, or for attaching mocks to a parent that records all calls to the children and allows you to make assertions about the order of calls between mocks: >>> parent = MagicMock() >>> child1 = MagicMock(return_value=None) >>> child2 = MagicMock(return_value=None) >>> parent.child1 = child1 >>> parent.child2 = child2 >>> child1(1) >>> child2(2) >>> parent.mock_calls [call.child1(1), call.child2(2)] The exception to this is if the mock has a name. This allows you to prevent the “parenting” if for some reason you don’t want it to happen. >>> mock = MagicMock() >>> not_a_child = MagicMock(name='not-a-child') >>> mock.attribute = not_a_child >>> mock.attribute() <MagicMock name='not-a-child()' id='...'> >>> mock.mock_calls [] Mocks created for you by *note patch(): 788. are automatically given names. To attach mocks that have names to a parent you use the *note attach_mock(): 30a8. method: >>> thing1 = object() >>> thing2 = object() >>> parent = MagicMock() >>> with patch('__main__.thing1', return_value=None) as child1: ... with patch('__main__.thing2', return_value=None) as child2: ... parent.attach_mock(child1, 'child1') ... parent.attach_mock(child2, 'child2') ... child1('one') ... child2('two') ... >>> parent.mock_calls [call.child1('one'), call.child2('two')]  File: python.info, Node: The patchers, Next: MagicMock and magic method support, Prev: The Mock Class, Up: unittest mock — mock object library 5.26.5.7 The patchers ..................... The patch decorators are used for patching objects only within the scope of the function they decorate. They automatically handle the unpatching for you, even if exceptions are raised. All of these functions can also be used in with statements or as class decorators. * Menu: * patch:: * patch.object: patch object. * patch.dict: patch dict. * patch.multiple: patch multiple. * patch methods; start and stop: patch methods start and stop. * patch builtins:: * TEST_PREFIX:: * Nesting Patch Decorators:: * Where to patch:: * Patching Descriptors and Proxy Objects::  File: python.info, Node: patch, Next: patch object, Up: The patchers 5.26.5.8 patch .............. Note: *note patch(): 788. is straightforward to use. The key is to do the patching in the right namespace. See the section *note where to patch: 30c7. -- Function: unittest.mock.patch (target, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs) *note patch(): 788. acts as a function decorator, class decorator or a context manager. Inside the body of the function or with statement, the `target' is patched with a `new' object. When the function/with statement exits the patch is undone. If `new' is omitted, then the target is replaced with an *note AsyncMock: 248. if the patched object is an async function or a *note MagicMock: 785. otherwise. If *note patch(): 788. is used as a decorator and `new' is omitted, the created mock is passed in as an extra argument to the decorated function. If *note patch(): 788. is used as a context manager the created mock is returned by the context manager. `target' should be a string in the form ‘'package.module.ClassName'’. The `target' is imported and the specified object replaced with the `new' object, so the `target' must be importable from the environment you are calling *note patch(): 788. from. The target is imported when the decorated function is executed, not at decoration time. The `spec' and `spec_set' keyword arguments are passed to the *note MagicMock: 785. if patch is creating one for you. In addition you can pass ‘spec=True’ or ‘spec_set=True’, which causes patch to pass in the object being mocked as the spec/spec_set object. `new_callable' allows you to specify a different class, or callable object, that will be called to create the `new' object. By default *note AsyncMock: 248. is used for async functions and *note MagicMock: 785. for the rest. A more powerful form of `spec' is `autospec'. If you set ‘autospec=True’ then the mock will be created with a spec from the object being replaced. All attributes of the mock will also have the spec of the corresponding attribute of the object being replaced. Methods and functions being mocked will have their arguments checked and will raise a *note TypeError: 192. if they are called with the wrong signature. For mocks replacing a class, their return value (the ‘instance’) will have the same spec as the class. See the *note create_autospec(): 309a. function and *note Autospeccing: 3099. Instead of ‘autospec=True’ you can pass ‘autospec=some_object’ to use an arbitrary object as the spec instead of the one being replaced. By default *note patch(): 788. will fail to replace attributes that don’t exist. If you pass in ‘create=True’, and the attribute doesn’t exist, patch will create the attribute for you when the patched function is called, and delete it again after the patched function has exited. This is useful for writing tests against attributes that your production code creates at runtime. It is off by default because it can be dangerous. With it switched on you can write passing tests against APIs that don’t actually exist! Note: Changed in version 3.5: If you are patching builtins in a module then you don’t need to pass ‘create=True’, it will be added by default. Patch can be used as a ‘TestCase’ class decorator. It works by decorating each test method in the class. This reduces the boilerplate code when your test methods share a common patchings set. *note patch(): 788. finds tests by looking for method names that start with ‘patch.TEST_PREFIX’. By default this is ‘'test'’, which matches the way *note unittest: 11b. finds tests. You can specify an alternative prefix by setting ‘patch.TEST_PREFIX’. Patch can be used as a context manager, with the with statement. Here the patching applies to the indented block after the with statement. If you use “as” then the patched object will be bound to the name after the “as”; very useful if *note patch(): 788. is creating a mock object for you. *note patch(): 788. takes arbitrary keyword arguments. These will be passed to the *note Mock: 249. (or `new_callable') on construction. ‘patch.dict(...)’, ‘patch.multiple(...)’ and ‘patch.object(...)’ are available for alternate use-cases. *note patch(): 788. as function decorator, creating the mock for you and passing it into the decorated function: >>> @patch('__main__.SomeClass') ... def function(normal_argument, mock_class): ... print(mock_class is SomeClass) ... >>> function(None) True Patching a class replaces the class with a *note MagicMock: 785. `instance'. If the class is instantiated in the code under test then it will be the *note return_value: 30a0. of the mock that will be used. If the class is instantiated multiple times you could use *note side_effect: 309e. to return a new mock each time. Alternatively you can set the `return_value' to be anything you want. To configure return values on methods of `instances' on the patched class you must do this on the ‘return_value’. For example: >>> class Class: ... def method(self): ... pass ... >>> with patch('__main__.Class') as MockClass: ... instance = MockClass.return_value ... instance.method.return_value = 'foo' ... assert Class() is instance ... assert Class().method() == 'foo' ... If you use `spec' or `spec_set' and *note patch(): 788. is replacing a `class', then the return value of the created mock will have the same spec. >>> Original = Class >>> patcher = patch('__main__.Class', spec=True) >>> MockClass = patcher.start() >>> instance = MockClass() >>> assert isinstance(instance, Original) >>> patcher.stop() The `new_callable' argument is useful where you want to use an alternative class to the default *note MagicMock: 785. for the created mock. For example, if you wanted a *note NonCallableMock: 309c. to be used: >>> thing = object() >>> with patch('__main__.thing', new_callable=NonCallableMock) as mock_thing: ... assert thing is mock_thing ... thing() ... Traceback (most recent call last): ... TypeError: 'NonCallableMock' object is not callable Another use case might be to replace an object with an *note io.StringIO: 82d. instance: >>> from io import StringIO >>> def foo(): ... print('Something') ... >>> @patch('sys.stdout', new_callable=StringIO) ... def test(mock_stdout): ... foo() ... assert mock_stdout.getvalue() == 'Something\n' ... >>> test() When *note patch(): 788. is creating a mock for you, it is common that the first thing you need to do is to configure the mock. Some of that configuration can be done in the call to patch. Any arbitrary keywords you pass into the call will be used to set attributes on the created mock: >>> patcher = patch('__main__.thing', first='one', second='two') >>> mock_thing = patcher.start() >>> mock_thing.first 'one' >>> mock_thing.second 'two' As well as attributes on the created mock attributes, like the *note return_value: 30a0. and *note side_effect: 309e, of child mocks can also be configured. These aren’t syntactically valid to pass in directly as keyword arguments, but a dictionary with these as keys can still be expanded into a *note patch(): 788. call using ‘**’: >>> config = {'method.return_value': 3, 'other.side_effect': KeyError} >>> patcher = patch('__main__.thing', **config) >>> mock_thing = patcher.start() >>> mock_thing.method() 3 >>> mock_thing.other() Traceback (most recent call last): ... KeyError By default, attempting to patch a function in a module (or a method or an attribute in a class) that does not exist will fail with *note AttributeError: 39b.: >>> @patch('sys.non_existing_attribute', 42) ... def test(): ... assert sys.non_existing_attribute == 42 ... >>> test() Traceback (most recent call last): ... AttributeError: <module 'sys' (built-in)> does not have the attribute 'non_existing' but adding ‘create=True’ in the call to *note patch(): 788. will make the previous example work as expected: >>> @patch('sys.non_existing_attribute', 42, create=True) ... def test(mock_stdout): ... assert sys.non_existing_attribute == 42 ... >>> test() Changed in version 3.8: *note patch(): 788. now returns an *note AsyncMock: 248. if the target is an async function.  File: python.info, Node: patch object, Next: patch dict, Prev: patch, Up: The patchers 5.26.5.9 patch.object ..................... -- Function: patch.object (target, attribute, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs) patch the named member (`attribute') on an object (`target') with a mock object. *note patch.object(): 30c9. can be used as a decorator, class decorator or a context manager. Arguments `new', `spec', `create', `spec_set', `autospec' and `new_callable' have the same meaning as for *note patch(): 788. Like *note patch(): 788, *note patch.object(): 30c9. takes arbitrary keyword arguments for configuring the mock object it creates. When used as a class decorator *note patch.object(): 30c9. honours ‘patch.TEST_PREFIX’ for choosing which methods to wrap. You can either call *note patch.object(): 30c9. with three arguments or two arguments. The three argument form takes the object to be patched, the attribute name and the object to replace the attribute with. When calling with the two argument form you omit the replacement object, and a mock is created for you and passed in as an extra argument to the decorated function: >>> @patch.object(SomeClass, 'class_method') ... def test(mock_method): ... SomeClass.class_method(3) ... mock_method.assert_called_with(3) ... >>> test() `spec', `create' and the other arguments to *note patch.object(): 30c9. have the same meaning as they do for *note patch(): 788.  File: python.info, Node: patch dict, Next: patch multiple, Prev: patch object, Up: The patchers 5.26.5.10 patch.dict .................... -- Function: patch.dict (in_dict, values=(), clear=False, **kwargs) Patch a dictionary, or dictionary like object, and restore the dictionary to its original state after the test. `in_dict' can be a dictionary or a mapping like container. If it is a mapping then it must at least support getting, setting and deleting items plus iterating over keys. `in_dict' can also be a string specifying the name of the dictionary, which will then be fetched by importing it. `values' can be a dictionary of values to set in the dictionary. `values' can also be an iterable of ‘(key, value)’ pairs. If `clear' is true then the dictionary will be cleared before the new values are set. *note patch.dict(): 3097. can also be called with arbitrary keyword arguments to set values in the dictionary. Changed in version 3.8: *note patch.dict(): 3097. now returns the patched dictionary when used as a context manager. *note patch.dict(): 3097. can be used as a context manager, decorator or class decorator: >>> foo = {} >>> @patch.dict(foo, {'newkey': 'newvalue'}) ... def test(): ... assert foo == {'newkey': 'newvalue'} >>> test() >>> assert foo == {} When used as a class decorator *note patch.dict(): 3097. honours ‘patch.TEST_PREFIX’ (default to ‘'test'’) for choosing which methods to wrap: >>> import os >>> import unittest >>> from unittest.mock import patch >>> @patch.dict('os.environ', {'newkey': 'newvalue'}) ... class TestSample(unittest.TestCase): ... def test_sample(self): ... self.assertEqual(os.environ['newkey'], 'newvalue') If you want to use a different prefix for your test, you can inform the patchers of the different prefix by setting ‘patch.TEST_PREFIX’. For more details about how to change the value of see *note TEST_PREFIX: 30cb. *note patch.dict(): 3097. can be used to add members to a dictionary, or simply let a test change a dictionary, and ensure the dictionary is restored when the test ends. >>> foo = {} >>> with patch.dict(foo, {'newkey': 'newvalue'}) as patched_foo: ... assert foo == {'newkey': 'newvalue'} ... assert patched_foo == {'newkey': 'newvalue'} ... # You can add, update or delete keys of foo (or patched_foo, it's the same dict) ... patched_foo['spam'] = 'eggs' ... >>> assert foo == {} >>> assert patched_foo == {} >>> import os >>> with patch.dict('os.environ', {'newkey': 'newvalue'}): ... print(os.environ['newkey']) ... newvalue >>> assert 'newkey' not in os.environ Keywords can be used in the *note patch.dict(): 3097. call to set values in the dictionary: >>> mymodule = MagicMock() >>> mymodule.function.return_value = 'fish' >>> with patch.dict('sys.modules', mymodule=mymodule): ... import mymodule ... mymodule.function('some', 'args') ... 'fish' *note patch.dict(): 3097. can be used with dictionary like objects that aren’t actually dictionaries. At the very minimum they must support item getting, setting, deleting and either iteration or membership test. This corresponds to the magic methods *note __getitem__(): 27c, *note __setitem__(): c62, *note __delitem__(): c63. and either *note __iter__(): 50f. or *note __contains__(): d28. >>> class Container: ... def __init__(self): ... self.values = {} ... def __getitem__(self, name): ... return self.values[name] ... def __setitem__(self, name, value): ... self.values[name] = value ... def __delitem__(self, name): ... del self.values[name] ... def __iter__(self): ... return iter(self.values) ... >>> thing = Container() >>> thing['one'] = 1 >>> with patch.dict(thing, one=2, two=3): ... assert thing['one'] == 2 ... assert thing['two'] == 3 ... >>> assert thing['one'] == 1 >>> assert list(thing) == ['one']  File: python.info, Node: patch multiple, Next: patch methods start and stop, Prev: patch dict, Up: The patchers 5.26.5.11 patch.multiple ........................ -- Function: patch.multiple (target, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs) Perform multiple patches in a single call. It takes the object to be patched (either as an object or a string to fetch the object by importing) and keyword arguments for the patches: with patch.multiple(settings, FIRST_PATCH='one', SECOND_PATCH='two'): ... Use *note DEFAULT: 309f. as the value if you want *note patch.multiple(): 30cd. to create mocks for you. In this case the created mocks are passed into a decorated function by keyword, and a dictionary is returned when *note patch.multiple(): 30cd. is used as a context manager. *note patch.multiple(): 30cd. can be used as a decorator, class decorator or a context manager. The arguments `spec', `spec_set', `create', `autospec' and `new_callable' have the same meaning as for *note patch(): 788. These arguments will be applied to `all' patches done by *note patch.multiple(): 30cd. When used as a class decorator *note patch.multiple(): 30cd. honours ‘patch.TEST_PREFIX’ for choosing which methods to wrap. If you want *note patch.multiple(): 30cd. to create mocks for you, then you can use *note DEFAULT: 309f. as the value. If you use *note patch.multiple(): 30cd. as a decorator then the created mocks are passed into the decorated function by keyword. >>> thing = object() >>> other = object() >>> @patch.multiple('__main__', thing=DEFAULT, other=DEFAULT) ... def test_function(thing, other): ... assert isinstance(thing, MagicMock) ... assert isinstance(other, MagicMock) ... >>> test_function() *note patch.multiple(): 30cd. can be nested with other ‘patch’ decorators, but put arguments passed by keyword `after' any of the standard arguments created by *note patch(): 788.: >>> @patch('sys.exit') ... @patch.multiple('__main__', thing=DEFAULT, other=DEFAULT) ... def test_function(mock_exit, other, thing): ... assert 'other' in repr(other) ... assert 'thing' in repr(thing) ... assert 'exit' in repr(mock_exit) ... >>> test_function() If *note patch.multiple(): 30cd. is used as a context manager, the value returned by the context manager is a dictionary where created mocks are keyed by name: >>> with patch.multiple('__main__', thing=DEFAULT, other=DEFAULT) as values: ... assert 'other' in repr(values['other']) ... assert 'thing' in repr(values['thing']) ... assert values['thing'] is thing ... assert values['other'] is other ...  File: python.info, Node: patch methods start and stop, Next: patch builtins, Prev: patch multiple, Up: The patchers 5.26.5.12 patch methods: start and stop ....................................... All the patchers have ‘start()’ and ‘stop()’ methods. These make it simpler to do patching in ‘setUp’ methods or where you want to do multiple patches without nesting decorators or with statements. To use them call *note patch(): 788, *note patch.object(): 30c9. or *note patch.dict(): 3097. as normal and keep a reference to the returned ‘patcher’ object. You can then call ‘start()’ to put the patch in place and ‘stop()’ to undo it. If you are using *note patch(): 788. to create a mock for you then it will be returned by the call to ‘patcher.start’. >>> patcher = patch('package.module.ClassName') >>> from package import module >>> original = module.ClassName >>> new_mock = patcher.start() >>> assert module.ClassName is not original >>> assert module.ClassName is new_mock >>> patcher.stop() >>> assert module.ClassName is original >>> assert module.ClassName is not new_mock A typical use case for this might be for doing multiple patches in the ‘setUp’ method of a ‘TestCase’: >>> class MyTest(unittest.TestCase): ... def setUp(self): ... self.patcher1 = patch('package.module.Class1') ... self.patcher2 = patch('package.module.Class2') ... self.MockClass1 = self.patcher1.start() ... self.MockClass2 = self.patcher2.start() ... ... def tearDown(self): ... self.patcher1.stop() ... self.patcher2.stop() ... ... def test_something(self): ... assert package.module.Class1 is self.MockClass1 ... assert package.module.Class2 is self.MockClass2 ... >>> MyTest('test_something').run() Caution: If you use this technique you must ensure that the patching is “undone” by calling ‘stop’. This can be fiddlier than you might think, because if an exception is raised in the ‘setUp’ then ‘tearDown’ is not called. *note unittest.TestCase.addCleanup(): 2a2. makes this easier: >>> class MyTest(unittest.TestCase): ... def setUp(self): ... patcher = patch('package.module.Class') ... self.MockClass = patcher.start() ... self.addCleanup(patcher.stop) ... ... def test_something(self): ... assert package.module.Class is self.MockClass ... As an added bonus you no longer need to keep a reference to the ‘patcher’ object. It is also possible to stop all patches which have been started by using *note patch.stopall(): 30d0. -- Function: patch.stopall () Stop all active patches. Only stops patches started with ‘start’.  File: python.info, Node: patch builtins, Next: TEST_PREFIX, Prev: patch methods start and stop, Up: The patchers 5.26.5.13 patch builtins ........................ You can patch any builtins within a module. The following example patches builtin *note ord(): 10c6.: >>> @patch('__main__.ord') ... def test(mock_ord): ... mock_ord.return_value = 101 ... print(ord('c')) ... >>> test() 101  File: python.info, Node: TEST_PREFIX, Next: Nesting Patch Decorators, Prev: patch builtins, Up: The patchers 5.26.5.14 TEST_PREFIX ..................... All of the patchers can be used as class decorators. When used in this way they wrap every test method on the class. The patchers recognise methods that start with ‘'test'’ as being test methods. This is the same way that the *note unittest.TestLoader: 782. finds test methods by default. It is possible that you want to use a different prefix for your tests. You can inform the patchers of the different prefix by setting ‘patch.TEST_PREFIX’: >>> patch.TEST_PREFIX = 'foo' >>> value = 3 >>> >>> @patch('__main__.value', 'not three') ... class Thing: ... def foo_one(self): ... print(value) ... def foo_two(self): ... print(value) ... >>> >>> Thing().foo_one() not three >>> Thing().foo_two() not three >>> value 3  File: python.info, Node: Nesting Patch Decorators, Next: Where to patch, Prev: TEST_PREFIX, Up: The patchers 5.26.5.15 Nesting Patch Decorators .................................. If you want to perform multiple patches then you can simply stack up the decorators. You can stack up multiple patch decorators using this pattern: >>> @patch.object(SomeClass, 'class_method') ... @patch.object(SomeClass, 'static_method') ... def test(mock1, mock2): ... assert SomeClass.static_method is mock1 ... assert SomeClass.class_method is mock2 ... SomeClass.static_method('foo') ... SomeClass.class_method('bar') ... return mock1, mock2 ... >>> mock1, mock2 = test() >>> mock1.assert_called_once_with('foo') >>> mock2.assert_called_once_with('bar') Note that the decorators are applied from the bottom upwards. This is the standard way that Python applies decorators. The order of the created mocks passed into your test function matches this order.  File: python.info, Node: Where to patch, Next: Patching Descriptors and Proxy Objects, Prev: Nesting Patch Decorators, Up: The patchers 5.26.5.16 Where to patch ........................ *note patch(): 788. works by (temporarily) changing the object that a `name' points to with another one. There can be many names pointing to any individual object, so for patching to work you must ensure that you patch the name used by the system under test. The basic principle is that you patch where an object is `looked up', which is not necessarily the same place as where it is defined. A couple of examples will help to clarify this. Imagine we have a project that we want to test with the following structure: a.py -> Defines SomeClass b.py -> from a import SomeClass -> some_function instantiates SomeClass Now we want to test ‘some_function’ but we want to mock out ‘SomeClass’ using *note patch(): 788. The problem is that when we import module b, which we will have to do then it imports ‘SomeClass’ from module a. If we use *note patch(): 788. to mock out ‘a.SomeClass’ then it will have no effect on our test; module b already has a reference to the `real' ‘SomeClass’ and it looks like our patching had no effect. The key is to patch out ‘SomeClass’ where it is used (or where it is looked up). In this case ‘some_function’ will actually look up ‘SomeClass’ in module b, where we have imported it. The patching should look like: @patch('b.SomeClass') However, consider the alternative scenario where instead of ‘from a import SomeClass’ module b does ‘import a’ and ‘some_function’ uses ‘a.SomeClass’. Both of these import forms are common. In this case the class we want to patch is being looked up in the module and so we have to patch ‘a.SomeClass’ instead: @patch('a.SomeClass')  File: python.info, Node: Patching Descriptors and Proxy Objects, Prev: Where to patch, Up: The patchers 5.26.5.17 Patching Descriptors and Proxy Objects ................................................ Both *note patch: 30c6. and *note patch.object: 30c8. correctly patch and restore descriptors: class methods, static methods and properties. You should patch these on the `class' rather than an instance. They also work with `some' objects that proxy attribute access, like the django settings object(1). ---------- Footnotes ---------- (1) http://www.voidspace.org.uk/python/weblog/arch_d7_2010_12_04.shtml#e1198  File: python.info, Node: MagicMock and magic method support, Next: Helpers, Prev: The patchers, Up: unittest mock — mock object library 5.26.5.18 MagicMock and magic method support ............................................ * Menu: * Mocking Magic Methods:: * Magic Mock::  File: python.info, Node: Mocking Magic Methods, Next: Magic Mock, Up: MagicMock and magic method support 5.26.5.19 Mocking Magic Methods ............................... *note Mock: 249. supports mocking the Python protocol methods, also known as “magic methods”. This allows mock objects to replace containers or other objects that implement Python protocols. Because magic methods are looked up differently from normal methods (1), this support has been specially implemented. This means that only specific magic methods are supported. The supported list includes `almost' all of them. If there are any missing that you need please let us know. You mock magic methods by setting the method you are interested in to a function or a mock instance. If you are using a function then it `must' take ‘self’ as the first argument (2). >>> def __str__(self): ... return 'fooble' ... >>> mock = Mock() >>> mock.__str__ = __str__ >>> str(mock) 'fooble' >>> mock = Mock() >>> mock.__str__ = Mock() >>> mock.__str__.return_value = 'fooble' >>> str(mock) 'fooble' >>> mock = Mock() >>> mock.__iter__ = Mock(return_value=iter([])) >>> list(mock) [] One use case for this is for mocking objects used as context managers in a *note with: 6e9. statement: >>> mock = Mock() >>> mock.__enter__ = Mock(return_value='foo') >>> mock.__exit__ = Mock(return_value=False) >>> with mock as m: ... assert m == 'foo' ... >>> mock.__enter__.assert_called_with() >>> mock.__exit__.assert_called_with(None, None, None) Calls to magic methods do not appear in *note method_calls: 30a9, but they are recorded in *note mock_calls: 30a6. Note: If you use the `spec' keyword argument to create a mock then attempting to set a magic method that isn’t in the spec will raise an *note AttributeError: 39b. The full list of supported magic methods is: * ‘__hash__’, ‘__sizeof__’, ‘__repr__’ and ‘__str__’ * ‘__dir__’, ‘__format__’ and ‘__subclasses__’ * ‘__round__’, ‘__floor__’, ‘__trunc__’ and ‘__ceil__’ * Comparisons: ‘__lt__’, ‘__gt__’, ‘__le__’, ‘__ge__’, ‘__eq__’ and ‘__ne__’ * Container methods: ‘__getitem__’, ‘__setitem__’, ‘__delitem__’, ‘__contains__’, ‘__len__’, ‘__iter__’, ‘__reversed__’ and ‘__missing__’ * Context manager: ‘__enter__’, ‘__exit__’, ‘__aenter__’ and ‘__aexit__’ * Unary numeric methods: ‘__neg__’, ‘__pos__’ and ‘__invert__’ * The numeric methods (including right hand and in-place variants): ‘__add__’, ‘__sub__’, ‘__mul__’, ‘__matmul__’, ‘__div__’, ‘__truediv__’, ‘__floordiv__’, ‘__mod__’, ‘__divmod__’, ‘__lshift__’, ‘__rshift__’, ‘__and__’, ‘__xor__’, ‘__or__’, and ‘__pow__’ * Numeric conversion methods: ‘__complex__’, ‘__int__’, ‘__float__’ and ‘__index__’ * Descriptor methods: ‘__get__’, ‘__set__’ and ‘__delete__’ * Pickling: ‘__reduce__’, ‘__reduce_ex__’, ‘__getinitargs__’, ‘__getnewargs__’, ‘__getstate__’ and ‘__setstate__’ * File system path representation: ‘__fspath__’ * Asynchronous iteration methods: ‘__aiter__’ and ‘__anext__’ Changed in version 3.8: Added support for *note os.PathLike.__fspath__(): 4ec. Changed in version 3.8: Added support for ‘__aenter__’, ‘__aexit__’, ‘__aiter__’ and ‘__anext__’. The following methods exist but are `not' supported as they are either in use by mock, can’t be set dynamically, or can cause problems: * ‘__getattr__’, ‘__setattr__’, ‘__init__’ and ‘__new__’ * ‘__prepare__’, ‘__instancecheck__’, ‘__subclasscheck__’, ‘__del__’ ---------- Footnotes ---------- (1) (2) Magic methods `should' be looked up on the class rather than the instance. Different versions of Python are inconsistent about applying this rule. The supported protocol methods should work with all supported versions of Python. (2) (3) The function is basically hooked up to the class, but each ‘Mock’ instance is kept isolated from the others.  File: python.info, Node: Magic Mock, Prev: Mocking Magic Methods, Up: MagicMock and magic method support 5.26.5.20 Magic Mock .................... There are two ‘MagicMock’ variants: *note MagicMock: 785. and *note NonCallableMagicMock: 309d. -- Class: unittest.mock.MagicMock (*args, **kw) ‘MagicMock’ is a subclass of *note Mock: 249. with default implementations of most of the magic methods. You can use ‘MagicMock’ without having to configure the magic methods yourself. The constructor parameters have the same meaning as for *note Mock: 249. If you use the `spec' or `spec_set' arguments then `only' magic methods that exist in the spec will be created. -- Class: unittest.mock.NonCallableMagicMock (*args, **kw) A non-callable version of *note MagicMock: 785. The constructor parameters have the same meaning as for *note MagicMock: 785, with the exception of `return_value' and `side_effect' which have no meaning on a non-callable mock. The magic methods are setup with *note MagicMock: 785. objects, so you can configure them and use them in the usual way: >>> mock = MagicMock() >>> mock[3] = 'fish' >>> mock.__setitem__.assert_called_with(3, 'fish') >>> mock.__getitem__.return_value = 'result' >>> mock[2] 'result' By default many of the protocol methods are required to return objects of a specific type. These methods are preconfigured with a default return value, so that they can be used without you having to do anything if you aren’t interested in the return value. You can still `set' the return value manually if you want to change the default. Methods and their defaults: * ‘__lt__’: ‘NotImplemented’ * ‘__gt__’: ‘NotImplemented’ * ‘__le__’: ‘NotImplemented’ * ‘__ge__’: ‘NotImplemented’ * ‘__int__’: ‘1’ * ‘__contains__’: ‘False’ * ‘__len__’: ‘0’ * ‘__iter__’: ‘iter([])’ * ‘__exit__’: ‘False’ * ‘__aexit__’: ‘False’ * ‘__complex__’: ‘1j’ * ‘__float__’: ‘1.0’ * ‘__bool__’: ‘True’ * ‘__index__’: ‘1’ * ‘__hash__’: default hash for the mock * ‘__str__’: default str for the mock * ‘__sizeof__’: default sizeof for the mock For example: >>> mock = MagicMock() >>> int(mock) 1 >>> len(mock) 0 >>> list(mock) [] >>> object() in mock False The two equality methods, *note __eq__(): 33f. and *note __ne__(): e56, are special. They do the default equality comparison on identity, using the *note side_effect: 309e. attribute, unless you change their return value to return something else: >>> MagicMock() == 3 False >>> MagicMock() != 3 True >>> mock = MagicMock() >>> mock.__eq__.return_value = True >>> mock == 3 True The return value of ‘MagicMock.__iter__()’ can be any iterable object and isn’t required to be an iterator: >>> mock = MagicMock() >>> mock.__iter__.return_value = ['a', 'b', 'c'] >>> list(mock) ['a', 'b', 'c'] >>> list(mock) ['a', 'b', 'c'] If the return value `is' an iterator, then iterating over it once will consume it and subsequent iterations will result in an empty list: >>> mock.__iter__.return_value = iter(['a', 'b', 'c']) >>> list(mock) ['a', 'b', 'c'] >>> list(mock) [] ‘MagicMock’ has all of the supported magic methods configured except for some of the obscure and obsolete ones. You can still set these up if you want. Magic methods that are supported but not setup by default in ‘MagicMock’ are: * ‘__subclasses__’ * ‘__dir__’ * ‘__format__’ * ‘__get__’, ‘__set__’ and ‘__delete__’ * ‘__reversed__’ and ‘__missing__’ * ‘__reduce__’, ‘__reduce_ex__’, ‘__getinitargs__’, ‘__getnewargs__’, ‘__getstate__’ and ‘__setstate__’ * ‘__getformat__’ and ‘__setformat__’  File: python.info, Node: Helpers, Prev: MagicMock and magic method support, Up: unittest mock — mock object library 5.26.5.21 Helpers ................. * Menu: * sentinel:: * DEFAULT:: * call:: * create_autospec:: * ANY:: * FILTER_DIR:: * mock_open:: * Autospeccing:: * Sealing mocks::  File: python.info, Node: sentinel, Next: DEFAULT, Up: Helpers 5.26.5.22 sentinel .................. -- Data: unittest.mock.sentinel The ‘sentinel’ object provides a convenient way of providing unique objects for your tests. Attributes are created on demand when you access them by name. Accessing the same attribute will always return the same object. The objects returned have a sensible repr so that test failure messages are readable. Changed in version 3.7: The ‘sentinel’ attributes now preserve their identity when they are *note copied: 26. or *note pickled: ca. Sometimes when testing you need to test that a specific object is passed as an argument to another method, or returned. It can be common to create named sentinel objects to test this. *note sentinel: 40a. provides a convenient way of creating and testing the identity of objects like this. In this example we monkey patch ‘method’ to return ‘sentinel.some_object’: >>> real = ProductionClass() >>> real.method = Mock(name="method") >>> real.method.return_value = sentinel.some_object >>> result = real.method() >>> assert result is sentinel.some_object >>> sentinel.some_object sentinel.some_object  File: python.info, Node: DEFAULT, Next: call, Prev: sentinel, Up: Helpers 5.26.5.23 DEFAULT ................. -- Data: unittest.mock.DEFAULT The *note DEFAULT: 309f. object is a pre-created sentinel (actually ‘sentinel.DEFAULT’). It can be used by *note side_effect: 309e. functions to indicate that the normal return value should be used.  File: python.info, Node: call, Next: create_autospec, Prev: DEFAULT, Up: Helpers 5.26.5.24 call .............. -- Function: unittest.mock.call (*args, **kwargs) *note call(): 30b1. is a helper object for making simpler assertions, for comparing with *note call_args: 30af, *note call_args_list: 30b0, *note mock_calls: 30a6. and *note method_calls: 30a9. *note call(): 30b1. can also be used with *note assert_has_calls(): 30a5. >>> m = MagicMock(return_value=None) >>> m(1, 2, a='foo', b='bar') >>> m() >>> m.call_args_list == [call(1, 2, a='foo', b='bar'), call()] True -- Method: call.call_list () For a call object that represents multiple calls, *note call_list(): 30dd. returns a list of all the intermediate calls as well as the final call. ‘call_list’ is particularly useful for making assertions on “chained calls”. A chained call is multiple calls on a single line of code. This results in multiple entries in *note mock_calls: 30a6. on a mock. Manually constructing the sequence of calls can be tedious. *note call_list(): 30dd. can construct the sequence of calls from the same chained call: >>> m = MagicMock() >>> m(1).method(arg='foo').other('bar')(2.0) <MagicMock name='mock().method().other()()' id='...'> >>> kall = call(1).method(arg='foo').other('bar')(2.0) >>> kall.call_list() [call(1), call().method(arg='foo'), call().method().other('bar'), call().method().other()(2.0)] >>> m.mock_calls == kall.call_list() True A ‘call’ object is either a tuple of (positional args, keyword args) or (name, positional args, keyword args) depending on how it was constructed. When you construct them yourself this isn’t particularly interesting, but the ‘call’ objects that are in the *note Mock.call_args: 30af, *note Mock.call_args_list: 30b0. and *note Mock.mock_calls: 30a6. attributes can be introspected to get at the individual arguments they contain. The ‘call’ objects in *note Mock.call_args: 30af. and *note Mock.call_args_list: 30b0. are two-tuples of (positional args, keyword args) whereas the ‘call’ objects in *note Mock.mock_calls: 30a6, along with ones you construct yourself, are three-tuples of (name, positional args, keyword args). You can use their “tupleness” to pull out the individual arguments for more complex introspection and assertions. The positional arguments are a tuple (an empty tuple if there are no positional arguments) and the keyword arguments are a dictionary: >>> m = MagicMock(return_value=None) >>> m(1, 2, 3, arg='one', arg2='two') >>> kall = m.call_args >>> kall.args (1, 2, 3) >>> kall.kwargs {'arg': 'one', 'arg2': 'two'} >>> kall.args is kall[0] True >>> kall.kwargs is kall[1] True >>> m = MagicMock() >>> m.foo(4, 5, 6, arg='two', arg2='three') <MagicMock name='mock.foo()' id='...'> >>> kall = m.mock_calls[0] >>> name, args, kwargs = kall >>> name 'foo' >>> args (4, 5, 6) >>> kwargs {'arg': 'two', 'arg2': 'three'} >>> name is m.mock_calls[0][0] True  File: python.info, Node: create_autospec, Next: ANY, Prev: call, Up: Helpers 5.26.5.25 create_autospec ......................... -- Function: unittest.mock.create_autospec (spec, spec_set=False, instance=False, **kwargs) Create a mock object using another object as a spec. Attributes on the mock will use the corresponding attribute on the `spec' object as their spec. Functions or methods being mocked will have their arguments checked to ensure that they are called with the correct signature. If `spec_set' is ‘True’ then attempting to set attributes that don’t exist on the spec object will raise an *note AttributeError: 39b. If a class is used as a spec then the return value of the mock (the instance of the class) will have the same spec. You can use a class as the spec for an instance object by passing ‘instance=True’. The returned mock will only be callable if instances of the mock are callable. *note create_autospec(): 309a. also takes arbitrary keyword arguments that are passed to the constructor of the created mock. See *note Autospeccing: 3099. for examples of how to use auto-speccing with *note create_autospec(): 309a. and the `autospec' argument to *note patch(): 788. Changed in version 3.8: *note create_autospec(): 309a. now returns an *note AsyncMock: 248. if the target is an async function.  File: python.info, Node: ANY, Next: FILTER_DIR, Prev: create_autospec, Up: Helpers 5.26.5.26 ANY ............. -- Data: unittest.mock.ANY Sometimes you may need to make assertions about `some' of the arguments in a call to mock, but either not care about some of the arguments or want to pull them individually out of *note call_args: 30af. and make more complex assertions on them. To ignore certain arguments you can pass in objects that compare equal to `everything'. Calls to *note assert_called_with(): 30a2. and *note assert_called_once_with(): 30a3. will then succeed no matter what was passed in. >>> mock = Mock(return_value=None) >>> mock('foo', bar=object()) >>> mock.assert_called_once_with('foo', bar=ANY) *note ANY: 30e0. can also be used in comparisons with call lists like *note mock_calls: 30a6.: >>> m = MagicMock(return_value=None) >>> m(1) >>> m(1, 2) >>> m(object()) >>> m.mock_calls == [call(1), call(1, 2), ANY] True  File: python.info, Node: FILTER_DIR, Next: mock_open, Prev: ANY, Up: Helpers 5.26.5.27 FILTER_DIR .................... -- Data: unittest.mock.FILTER_DIR *note FILTER_DIR: 30ab. is a module level variable that controls the way mock objects respond to *note dir(): d33. (only for Python 2.6 or more recent). The default is ‘True’, which uses the filtering described below, to only show useful members. If you dislike this filtering, or need to switch it off for diagnostic purposes, then set ‘mock.FILTER_DIR = False’. With filtering on, ‘dir(some_mock)’ shows only useful attributes and will include any dynamically created attributes that wouldn’t normally be shown. If the mock was created with a `spec' (or `autospec' of course) then all the attributes from the original are shown, even if they haven’t been accessed yet: >>> dir(Mock()) ['assert_any_call', 'assert_called', 'assert_called_once', 'assert_called_once_with', 'assert_called_with', 'assert_has_calls', 'assert_not_called', 'attach_mock', ... >>> from urllib import request >>> dir(Mock(spec=request)) ['AbstractBasicAuthHandler', 'AbstractDigestAuthHandler', 'AbstractHTTPHandler', 'BaseHandler', ... Many of the not-very-useful (private to *note Mock: 249. rather than the thing being mocked) underscore and double underscore prefixed attributes have been filtered from the result of calling *note dir(): d33. on a *note Mock: 249. If you dislike this behaviour you can switch it off by setting the module level switch *note FILTER_DIR: 30ab.: >>> from unittest import mock >>> mock.FILTER_DIR = False >>> dir(mock.Mock()) ['_NonCallableMock__get_return_value', '_NonCallableMock__get_side_effect', '_NonCallableMock__return_value_doc', '_NonCallableMock__set_return_value', '_NonCallableMock__set_side_effect', '__call__', '__class__', ... Alternatively you can just use ‘vars(my_mock)’ (instance members) and ‘dir(type(my_mock))’ (type members) to bypass the filtering irrespective of ‘mock.FILTER_DIR’.  File: python.info, Node: mock_open, Next: Autospeccing, Prev: FILTER_DIR, Up: Helpers 5.26.5.28 mock_open ................... -- Function: unittest.mock.mock_open (mock=None, read_data=None) A helper function to create a mock to replace the use of *note open(): 4f0. It works for *note open(): 4f0. called directly or used as a context manager. The `mock' argument is the mock object to configure. If ‘None’ (the default) then a *note MagicMock: 785. will be created for you, with the API limited to methods or attributes available on standard file handles. `read_data' is a string for the ‘read()’, *note readline(): 13ae, and *note readlines(): 1438. methods of the file handle to return. Calls to those methods will take data from `read_data' until it is depleted. The mock of these methods is pretty simplistic: every time the `mock' is called, the `read_data' is rewound to the start. If you need more control over the data that you are feeding to the tested code you will need to customize this mock for yourself. When that is insufficient, one of the in-memory filesystem packages on PyPI(1) can offer a realistic filesystem for testing. Changed in version 3.4: Added *note readline(): 13ae. and *note readlines(): 1438. support. The mock of ‘read()’ changed to consume `read_data' rather than returning it on each call. Changed in version 3.5: `read_data' is now reset on each call to the `mock'. Changed in version 3.8: Added *note __iter__(): 50f. to implementation so that iteration (such as in for loops) correctly consumes `read_data'. Using *note open(): 4f0. as a context manager is a great way to ensure your file handles are closed properly and is becoming common: with open('/some/path', 'w') as f: f.write('something') The issue is that even if you mock out the call to *note open(): 4f0. it is the `returned object' that is used as a context manager (and has *note __enter__(): c95. and *note __exit__(): c96. called). Mocking context managers with a *note MagicMock: 785. is common enough and fiddly enough that a helper function is useful. >>> m = mock_open() >>> with patch('__main__.open', m): ... with open('foo', 'w') as h: ... h.write('some stuff') ... >>> m.mock_calls [call('foo', 'w'), call().__enter__(), call().write('some stuff'), call().__exit__(None, None, None)] >>> m.assert_called_once_with('foo', 'w') >>> handle = m() >>> handle.write.assert_called_once_with('some stuff') And for reading files: >>> with patch('__main__.open', mock_open(read_data='bibble')) as m: ... with open('foo') as h: ... result = h.read() ... >>> m.assert_called_once_with('foo') >>> assert result == 'bibble' ---------- Footnotes ---------- (1) https://pypi.org  File: python.info, Node: Autospeccing, Next: Sealing mocks, Prev: mock_open, Up: Helpers 5.26.5.29 Autospeccing ...................... Autospeccing is based on the existing ‘spec’ feature of mock. It limits the api of mocks to the api of an original object (the spec), but it is recursive (implemented lazily) so that attributes of mocks only have the same api as the attributes of the spec. In addition mocked functions / methods have the same call signature as the original so they raise a *note TypeError: 192. if they are called incorrectly. Before I explain how auto-speccing works, here’s why it is needed. *note Mock: 249. is a very powerful and flexible object, but it suffers from two flaws when used to mock out objects from a system under test. One of these flaws is specific to the *note Mock: 249. api and the other is a more general problem with using mock objects. First the problem specific to *note Mock: 249. *note Mock: 249. has two assert methods that are extremely handy: *note assert_called_with(): 30a2. and *note assert_called_once_with(): 30a3. >>> mock = Mock(name='Thing', return_value=None) >>> mock(1, 2, 3) >>> mock.assert_called_once_with(1, 2, 3) >>> mock(1, 2, 3) >>> mock.assert_called_once_with(1, 2, 3) Traceback (most recent call last): ... AssertionError: Expected 'mock' to be called once. Called 2 times. Because mocks auto-create attributes on demand, and allow you to call them with arbitrary arguments, if you misspell one of these assert methods then your assertion is gone: >>> mock = Mock(name='Thing', return_value=None) >>> mock(1, 2, 3) >>> mock.assret_called_once_with(4, 5, 6) Your tests can pass silently and incorrectly because of the typo. The second issue is more general to mocking. If you refactor some of your code, rename members and so on, any tests for code that is still using the `old api' but uses mocks instead of the real objects will still pass. This means your tests can all pass even though your code is broken. Note that this is another reason why you need integration tests as well as unit tests. Testing everything in isolation is all fine and dandy, but if you don’t test how your units are “wired together” there is still lots of room for bugs that tests might have caught. ‘mock’ already provides a feature to help with this, called speccing. If you use a class or instance as the ‘spec’ for a mock then you can only access attributes on the mock that exist on the real class: >>> from urllib import request >>> mock = Mock(spec=request.Request) >>> mock.assret_called_with Traceback (most recent call last): ... AttributeError: Mock object has no attribute 'assret_called_with' The spec only applies to the mock itself, so we still have the same issue with any methods on the mock: >>> mock.has_data() <mock.Mock object at 0x...> >>> mock.has_data.assret_called_with() Auto-speccing solves this problem. You can either pass ‘autospec=True’ to *note patch(): 788. / *note patch.object(): 30c9. or use the *note create_autospec(): 309a. function to create a mock with a spec. If you use the ‘autospec=True’ argument to *note patch(): 788. then the object that is being replaced will be used as the spec object. Because the speccing is done “lazily” (the spec is created as attributes on the mock are accessed) you can use it with very complex or deeply nested objects (like modules that import modules that import modules) without a big performance hit. Here’s an example of it in use: >>> from urllib import request >>> patcher = patch('__main__.request', autospec=True) >>> mock_request = patcher.start() >>> request is mock_request True >>> mock_request.Request <MagicMock name='request.Request' spec='Request' id='...'> You can see that ‘request.Request’ has a spec. ‘request.Request’ takes two arguments in the constructor (one of which is `self'). Here’s what happens if we try to call it incorrectly: >>> req = request.Request() Traceback (most recent call last): ... TypeError: <lambda>() takes at least 2 arguments (1 given) The spec also applies to instantiated classes (i.e. the return value of specced mocks): >>> req = request.Request('foo') >>> req <NonCallableMagicMock name='request.Request()' spec='Request' id='...'> ‘Request’ objects are not callable, so the return value of instantiating our mocked out ‘request.Request’ is a non-callable mock. With the spec in place any typos in our asserts will raise the correct error: >>> req.add_header('spam', 'eggs') <MagicMock name='request.Request().add_header()' id='...'> >>> req.add_header.assret_called_with Traceback (most recent call last): ... AttributeError: Mock object has no attribute 'assret_called_with' >>> req.add_header.assert_called_with('spam', 'eggs') In many cases you will just be able to add ‘autospec=True’ to your existing *note patch(): 788. calls and then be protected against bugs due to typos and api changes. As well as using `autospec' through *note patch(): 788. there is a *note create_autospec(): 309a. for creating autospecced mocks directly: >>> from urllib import request >>> mock_request = create_autospec(request) >>> mock_request.Request('foo', 'bar') <NonCallableMagicMock name='mock.Request()' spec='Request' id='...'> This isn’t without caveats and limitations however, which is why it is not the default behaviour. In order to know what attributes are available on the spec object, autospec has to introspect (access attributes) the spec. As you traverse attributes on the mock a corresponding traversal of the original object is happening under the hood. If any of your specced objects have properties or descriptors that can trigger code execution then you may not be able to use autospec. On the other hand it is much better to design your objects so that introspection is safe (1). A more serious problem is that it is common for instance attributes to be created in the *note __init__(): d5e. method and not to exist on the class at all. `autospec' can’t know about any dynamically created attributes and restricts the api to visible attributes. >>> class Something: ... def __init__(self): ... self.a = 33 ... >>> with patch('__main__.Something', autospec=True): ... thing = Something() ... thing.a ... Traceback (most recent call last): ... AttributeError: Mock object has no attribute 'a' There are a few different ways of resolving this problem. The easiest, but not necessarily the least annoying, way is to simply set the required attributes on the mock after creation. Just because `autospec' doesn’t allow you to fetch attributes that don’t exist on the spec it doesn’t prevent you setting them: >>> with patch('__main__.Something', autospec=True): ... thing = Something() ... thing.a = 33 ... There is a more aggressive version of both `spec' and `autospec' that `does' prevent you setting non-existent attributes. This is useful if you want to ensure your code only `sets' valid attributes too, but obviously it prevents this particular scenario: >>> with patch('__main__.Something', autospec=True, spec_set=True): ... thing = Something() ... thing.a = 33 ... Traceback (most recent call last): ... AttributeError: Mock object has no attribute 'a' Probably the best way of solving the problem is to add class attributes as default values for instance members initialised in *note __init__(): d5e. Note that if you are only setting default attributes in *note __init__(): d5e. then providing them via class attributes (shared between instances of course) is faster too. e.g. class Something: a = 33 This brings up another issue. It is relatively common to provide a default value of ‘None’ for members that will later be an object of a different type. ‘None’ would be useless as a spec because it wouldn’t let you access `any' attributes or methods on it. As ‘None’ is `never' going to be useful as a spec, and probably indicates a member that will normally of some other type, autospec doesn’t use a spec for members that are set to ‘None’. These will just be ordinary mocks (well - MagicMocks): >>> class Something: ... member = None ... >>> mock = create_autospec(Something) >>> mock.member.foo.bar.baz() <MagicMock name='mock.member.foo.bar.baz()' id='...'> If modifying your production classes to add defaults isn’t to your liking then there are more options. One of these is simply to use an instance as the spec rather than the class. The other is to create a subclass of the production class and add the defaults to the subclass without affecting the production class. Both of these require you to use an alternative object as the spec. Thankfully *note patch(): 788. supports this - you can simply pass the alternative object as the `autospec' argument: >>> class Something: ... def __init__(self): ... self.a = 33 ... >>> class SomethingForTest(Something): ... a = 33 ... >>> p = patch('__main__.Something', autospec=SomethingForTest) >>> mock = p.start() >>> mock.a <NonCallableMagicMock name='Something.a' spec='int' id='...'> ---------- Footnotes ---------- (1) (4) This only applies to classes or already instantiated objects. Calling a mocked class to create a mock instance `does not' create a real instance. It is only attribute lookups - along with calls to *note dir(): d33. - that are done.  File: python.info, Node: Sealing mocks, Prev: Autospeccing, Up: Helpers 5.26.5.30 Sealing mocks ....................... -- Function: unittest.mock.seal (mock) Seal will disable the automatic creation of mocks when accessing an attribute of the mock being sealed or any of its attributes that are already mocks recursively. If a mock instance with a name or a spec is assigned to an attribute it won’t be considered in the sealing chain. This allows one to prevent seal from fixing part of the mock object. >>> mock = Mock() >>> mock.submock.attribute1 = 2 >>> mock.not_submock = mock.Mock(name="sample_name") >>> seal(mock) >>> mock.new_attribute # This will raise AttributeError. >>> mock.submock.attribute2 # This will raise AttributeError. >>> mock.not_submock.attribute2 # This won't raise. New in version 3.7.  File: python.info, Node: unittest mock — getting started, Next: 2to3 - Automated Python 2 to 3 code translation, Prev: unittest mock — mock object library, Up: Development Tools 5.26.6 ‘unittest.mock’ — getting started ---------------------------------------- New in version 3.3. * Menu: * Using Mock:: * Patch Decorators:: * Further Examples::  File: python.info, Node: Using Mock, Next: Patch Decorators, Up: unittest mock — getting started 5.26.6.1 Using Mock ................... * Menu: * Mock Patching Methods:: * Mock for Method Calls on an Object:: * Mocking Classes:: * Naming your mocks:: * Tracking all Calls:: * Setting Return Values and Attributes:: * Raising exceptions with mocks:: * Side effect functions and iterables:: * Mocking asynchronous iterators:: * Mocking asynchronous context manager:: * Creating a Mock from an Existing Object::  File: python.info, Node: Mock Patching Methods, Next: Mock for Method Calls on an Object, Up: Using Mock 5.26.6.2 Mock Patching Methods .............................. Common uses for *note Mock: 249. objects include: * Patching methods * Recording method calls on objects You might want to replace a method on an object to check that it is called with the correct arguments by another part of the system: >>> real = SomeClass() >>> real.method = MagicMock(name='method') >>> real.method(3, 4, 5, key='value') <MagicMock name='method()' id='...'> Once our mock has been used (‘real.method’ in this example) it has methods and attributes that allow you to make assertions about how it has been used. Note: In most of these examples the *note Mock: 249. and *note MagicMock: 785. classes are interchangeable. As the ‘MagicMock’ is the more capable class it makes a sensible one to use by default. Once the mock has been called its *note called: 30ad. attribute is set to ‘True’. More importantly we can use the *note assert_called_with(): 30a2. or *note assert_called_once_with(): 30a3. method to check that it was called with the correct arguments. This example tests that calling ‘ProductionClass().method’ results in a call to the ‘something’ method: >>> class ProductionClass: ... def method(self): ... self.something(1, 2, 3) ... def something(self, a, b, c): ... pass ... >>> real = ProductionClass() >>> real.something = MagicMock() >>> real.method() >>> real.something.assert_called_once_with(1, 2, 3)  File: python.info, Node: Mock for Method Calls on an Object, Next: Mocking Classes, Prev: Mock Patching Methods, Up: Using Mock 5.26.6.3 Mock for Method Calls on an Object ........................................... In the last example we patched a method directly on an object to check that it was called correctly. Another common use case is to pass an object into a method (or some part of the system under test) and then check that it is used in the correct way. The simple ‘ProductionClass’ below has a ‘closer’ method. If it is called with an object then it calls ‘close’ on it. >>> class ProductionClass: ... def closer(self, something): ... something.close() ... So to test it we need to pass in an object with a ‘close’ method and check that it was called correctly. >>> real = ProductionClass() >>> mock = Mock() >>> real.closer(mock) >>> mock.close.assert_called_with() We don’t have to do any work to provide the ‘close’ method on our mock. Accessing close creates it. So, if ‘close’ hasn’t already been called then accessing it in the test will create it, but *note assert_called_with(): 30a2. will raise a failure exception.  File: python.info, Node: Mocking Classes, Next: Naming your mocks, Prev: Mock for Method Calls on an Object, Up: Using Mock 5.26.6.4 Mocking Classes ........................ A common use case is to mock out classes instantiated by your code under test. When you patch a class, then that class is replaced with a mock. Instances are created by `calling the class'. This means you access the “mock instance” by looking at the return value of the mocked class. In the example below we have a function ‘some_function’ that instantiates ‘Foo’ and calls a method on it. The call to *note patch(): 788. replaces the class ‘Foo’ with a mock. The ‘Foo’ instance is the result of calling the mock, so it is configured by modifying the mock *note return_value: 30a0. >>> def some_function(): ... instance = module.Foo() ... return instance.method() ... >>> with patch('module.Foo') as mock: ... instance = mock.return_value ... instance.method.return_value = 'the result' ... result = some_function() ... assert result == 'the result'  File: python.info, Node: Naming your mocks, Next: Tracking all Calls, Prev: Mocking Classes, Up: Using Mock 5.26.6.5 Naming your mocks .......................... It can be useful to give your mocks a name. The name is shown in the repr of the mock and can be helpful when the mock appears in test failure messages. The name is also propagated to attributes or methods of the mock: >>> mock = MagicMock(name='foo') >>> mock <MagicMock name='foo' id='...'> >>> mock.method <MagicMock name='foo.method' id='...'>  File: python.info, Node: Tracking all Calls, Next: Setting Return Values and Attributes, Prev: Naming your mocks, Up: Using Mock 5.26.6.6 Tracking all Calls ........................... Often you want to track more than a single call to a method. The *note mock_calls: 30a6. attribute records all calls to child attributes of the mock - and also to their children. >>> mock = MagicMock() >>> mock.method() <MagicMock name='mock.method()' id='...'> >>> mock.attribute.method(10, x=53) <MagicMock name='mock.attribute.method()' id='...'> >>> mock.mock_calls [call.method(), call.attribute.method(10, x=53)] If you make an assertion about ‘mock_calls’ and any unexpected methods have been called, then the assertion will fail. This is useful because as well as asserting that the calls you expected have been made, you are also checking that they were made in the right order and with no additional calls: You use the *note call: 30b1. object to construct lists for comparing with ‘mock_calls’: >>> expected = [call.method(), call.attribute.method(10, x=53)] >>> mock.mock_calls == expected True However, parameters to calls that return mocks are not recorded, which means it is not possible to track nested calls where the parameters used to create ancestors are important: >>> m = Mock() >>> m.factory(important=True).deliver() <Mock name='mock.factory().deliver()' id='...'> >>> m.mock_calls[-1] == call.factory(important=False).deliver() True  File: python.info, Node: Setting Return Values and Attributes, Next: Raising exceptions with mocks, Prev: Tracking all Calls, Up: Using Mock 5.26.6.7 Setting Return Values and Attributes ............................................. Setting the return values on a mock object is trivially easy: >>> mock = Mock() >>> mock.return_value = 3 >>> mock() 3 Of course you can do the same for methods on the mock: >>> mock = Mock() >>> mock.method.return_value = 3 >>> mock.method() 3 The return value can also be set in the constructor: >>> mock = Mock(return_value=3) >>> mock() 3 If you need an attribute setting on your mock, just do it: >>> mock = Mock() >>> mock.x = 3 >>> mock.x 3 Sometimes you want to mock up a more complex situation, like for example ‘mock.connection.cursor().execute("SELECT 1")’. If we wanted this call to return a list, then we have to configure the result of the nested call. We can use *note call: 30b1. to construct the set of calls in a “chained call” like this for easy assertion afterwards: >>> mock = Mock() >>> cursor = mock.connection.cursor.return_value >>> cursor.execute.return_value = ['foo'] >>> mock.connection.cursor().execute("SELECT 1") ['foo'] >>> expected = call.connection.cursor().execute("SELECT 1").call_list() >>> mock.mock_calls [call.connection.cursor(), call.connection.cursor().execute('SELECT 1')] >>> mock.mock_calls == expected True It is the call to ‘.call_list()’ that turns our call object into a list of calls representing the chained calls.  File: python.info, Node: Raising exceptions with mocks, Next: Side effect functions and iterables, Prev: Setting Return Values and Attributes, Up: Using Mock 5.26.6.8 Raising exceptions with mocks ...................................... A useful attribute is *note side_effect: 309e. If you set this to an exception class or instance then the exception will be raised when the mock is called. >>> mock = Mock(side_effect=Exception('Boom!')) >>> mock() Traceback (most recent call last): ... Exception: Boom!  File: python.info, Node: Side effect functions and iterables, Next: Mocking asynchronous iterators, Prev: Raising exceptions with mocks, Up: Using Mock 5.26.6.9 Side effect functions and iterables ............................................ ‘side_effect’ can also be set to a function or an iterable. The use case for ‘side_effect’ as an iterable is where your mock is going to be called several times, and you want each call to return a different value. When you set ‘side_effect’ to an iterable every call to the mock returns the next value from the iterable: >>> mock = MagicMock(side_effect=[4, 5, 6]) >>> mock() 4 >>> mock() 5 >>> mock() 6 For more advanced use cases, like dynamically varying the return values depending on what the mock is called with, ‘side_effect’ can be a function. The function will be called with the same arguments as the mock. Whatever the function returns is what the call returns: >>> vals = {(1, 2): 1, (2, 3): 2} >>> def side_effect(*args): ... return vals[args] ... >>> mock = MagicMock(side_effect=side_effect) >>> mock(1, 2) 1 >>> mock(2, 3) 2  File: python.info, Node: Mocking asynchronous iterators, Next: Mocking asynchronous context manager, Prev: Side effect functions and iterables, Up: Using Mock 5.26.6.10 Mocking asynchronous iterators ........................................ Since Python 3.8, ‘AsyncMock’ and ‘MagicMock’ have support to mock *note Asynchronous Iterators: 646. through ‘__aiter__’. The *note return_value: 30a0. attribute of ‘__aiter__’ can be used to set the return values to be used for iteration. >>> mock = MagicMock() # AsyncMock also works here >>> mock.__aiter__.return_value = [1, 2, 3] >>> async def main(): ... return [i async for i in mock] ... >>> asyncio.run(main()) [1, 2, 3]  File: python.info, Node: Mocking asynchronous context manager, Next: Creating a Mock from an Existing Object, Prev: Mocking asynchronous iterators, Up: Using Mock 5.26.6.11 Mocking asynchronous context manager .............................................. Since Python 3.8, ‘AsyncMock’ and ‘MagicMock’ have support to mock *note Asynchronous Context Managers: 1139. through ‘__aenter__’ and ‘__aexit__’. By default, ‘__aenter__’ and ‘__aexit__’ are ‘AsyncMock’ instances that return an async function. >>> class AsyncContextManager: ... async def __aenter__(self): ... return self ... async def __aexit__(self, exc_type, exc, tb): ... pass ... >>> mock_instance = MagicMock(AsyncContextManager()) # AsyncMock also works here >>> async def main(): ... async with mock_instance as result: ... pass ... >>> asyncio.run(main()) >>> mock_instance.__aenter__.assert_awaited_once() >>> mock_instance.__aexit__.assert_awaited_once()  File: python.info, Node: Creating a Mock from an Existing Object, Prev: Mocking asynchronous context manager, Up: Using Mock 5.26.6.12 Creating a Mock from an Existing Object ................................................. One problem with over use of mocking is that it couples your tests to the implementation of your mocks rather than your real code. Suppose you have a class that implements ‘some_method’. In a test for another class, you provide a mock of this object that `also' provides ‘some_method’. If later you refactor the first class, so that it no longer has ‘some_method’ - then your tests will continue to pass even though your code is now broken! *note Mock: 249. allows you to provide an object as a specification for the mock, using the `spec' keyword argument. Accessing methods / attributes on the mock that don’t exist on your specification object will immediately raise an attribute error. If you change the implementation of your specification, then tests that use that class will start failing immediately without you having to instantiate the class in those tests. >>> mock = Mock(spec=SomeClass) >>> mock.old_method() Traceback (most recent call last): ... AttributeError: object has no attribute 'old_method' Using a specification also enables a smarter matching of calls made to the mock, regardless of whether some parameters were passed as positional or named arguments: >>> def f(a, b, c): pass ... >>> mock = Mock(spec=f) >>> mock(1, 2, 3) <Mock name='mock()' id='140161580456576'> >>> mock.assert_called_with(a=1, b=2, c=3) If you want this smarter matching to also work with method calls on the mock, you can use *note auto-speccing: 3099. If you want a stronger form of specification that prevents the setting of arbitrary attributes as well as the getting of them then you can use `spec_set' instead of `spec'.  File: python.info, Node: Patch Decorators, Next: Further Examples, Prev: Using Mock, Up: unittest mock — getting started 5.26.6.13 Patch Decorators .......................... Note: With *note patch(): 788. it matters that you patch objects in the namespace where they are looked up. This is normally straightforward, but for a quick guide read *note where to patch: 3096. A common need in tests is to patch a class attribute or a module attribute, for example patching a builtin or patching a class in a module to test that it is instantiated. Modules and classes are effectively global, so patching on them has to be undone after the test or the patch will persist into other tests and cause hard to diagnose problems. mock provides three convenient decorators for this: *note patch(): 788, *note patch.object(): 30c9. and *note patch.dict(): 3097. ‘patch’ takes a single string, of the form ‘package.module.Class.attribute’ to specify the attribute you are patching. It also optionally takes a value that you want the attribute (or class or whatever) to be replaced with. ‘patch.object’ takes an object and the name of the attribute you would like patched, plus optionally the value to patch it with. ‘patch.object’: >>> original = SomeClass.attribute >>> @patch.object(SomeClass, 'attribute', sentinel.attribute) ... def test(): ... assert SomeClass.attribute == sentinel.attribute ... >>> test() >>> assert SomeClass.attribute == original >>> @patch('package.module.attribute', sentinel.attribute) ... def test(): ... from package.module import attribute ... assert attribute is sentinel.attribute ... >>> test() If you are patching a module (including *note builtins: 13.) then use *note patch(): 788. instead of *note patch.object(): 30c9.: >>> mock = MagicMock(return_value=sentinel.file_handle) >>> with patch('builtins.open', mock): ... handle = open('filename', 'r') ... >>> mock.assert_called_with('filename', 'r') >>> assert handle == sentinel.file_handle, "incorrect file handle returned" The module name can be ‘dotted’, in the form ‘package.module’ if needed: >>> @patch('package.module.ClassName.attribute', sentinel.attribute) ... def test(): ... from package.module import ClassName ... assert ClassName.attribute == sentinel.attribute ... >>> test() A nice pattern is to actually decorate test methods themselves: >>> class MyTest(unittest.TestCase): ... @patch.object(SomeClass, 'attribute', sentinel.attribute) ... def test_something(self): ... self.assertEqual(SomeClass.attribute, sentinel.attribute) ... >>> original = SomeClass.attribute >>> MyTest('test_something').test_something() >>> assert SomeClass.attribute == original If you want to patch with a Mock, you can use *note patch(): 788. with only one argument (or *note patch.object(): 30c9. with two arguments). The mock will be created for you and passed into the test function / method: >>> class MyTest(unittest.TestCase): ... @patch.object(SomeClass, 'static_method') ... def test_something(self, mock_method): ... SomeClass.static_method() ... mock_method.assert_called_with() ... >>> MyTest('test_something').test_something() You can stack up multiple patch decorators using this pattern: >>> class MyTest(unittest.TestCase): ... @patch('package.module.ClassName1') ... @patch('package.module.ClassName2') ... def test_something(self, MockClass2, MockClass1): ... self.assertIs(package.module.ClassName1, MockClass1) ... self.assertIs(package.module.ClassName2, MockClass2) ... >>> MyTest('test_something').test_something() When you nest patch decorators the mocks are passed in to the decorated function in the same order they applied (the normal `Python' order that decorators are applied). This means from the bottom up, so in the example above the mock for ‘test_module.ClassName2’ is passed in first. There is also *note patch.dict(): 3097. for setting values in a dictionary just during a scope and restoring the dictionary to its original state when the test ends: >>> foo = {'key': 'value'} >>> original = foo.copy() >>> with patch.dict(foo, {'newkey': 'newvalue'}, clear=True): ... assert foo == {'newkey': 'newvalue'} ... >>> assert foo == original ‘patch’, ‘patch.object’ and ‘patch.dict’ can all be used as context managers. Where you use *note patch(): 788. to create a mock for you, you can get a reference to the mock using the “as” form of the with statement: >>> class ProductionClass: ... def method(self): ... pass ... >>> with patch.object(ProductionClass, 'method') as mock_method: ... mock_method.return_value = None ... real = ProductionClass() ... real.method(1, 2, 3) ... >>> mock_method.assert_called_with(1, 2, 3) As an alternative ‘patch’, ‘patch.object’ and ‘patch.dict’ can be used as class decorators. When used in this way it is the same as applying the decorator individually to every method whose name starts with “test”.  File: python.info, Node: Further Examples, Prev: Patch Decorators, Up: unittest mock — getting started 5.26.6.14 Further Examples .......................... Here are some more examples for some slightly more advanced scenarios. * Menu: * Mocking chained calls:: * Partial mocking:: * Mocking a Generator Method:: * Applying the same patch to every test method:: * Mocking Unbound Methods:: * Checking multiple calls with mock:: * Coping with mutable arguments:: * Nesting Patches:: * Mocking a dictionary with MagicMock:: * Mock subclasses and their attributes:: * Mocking imports with patch.dict: Mocking imports with patch dict. * Tracking order of calls and less verbose call assertions:: * More complex argument matching::  File: python.info, Node: Mocking chained calls, Next: Partial mocking, Up: Further Examples 5.26.6.15 Mocking chained calls ............................... Mocking chained calls is actually straightforward with mock once you understand the *note return_value: 30a0. attribute. When a mock is called for the first time, or you fetch its ‘return_value’ before it has been called, a new *note Mock: 249. is created. This means that you can see how the object returned from a call to a mocked object has been used by interrogating the ‘return_value’ mock: >>> mock = Mock() >>> mock().foo(a=2, b=3) <Mock name='mock().foo()' id='...'> >>> mock.return_value.foo.assert_called_with(a=2, b=3) From here it is a simple step to configure and then make assertions about chained calls. Of course another alternative is writing your code in a more testable way in the first place… So, suppose we have some code that looks a little bit like this: >>> class Something: ... def __init__(self): ... self.backend = BackendProvider() ... def method(self): ... response = self.backend.get_endpoint('foobar').create_call('spam', 'eggs').start_call() ... # more code Assuming that ‘BackendProvider’ is already well tested, how do we test ‘method()’? Specifically, we want to test that the code section ‘# more code’ uses the response object in the correct way. As this chain of calls is made from an instance attribute we can monkey patch the ‘backend’ attribute on a ‘Something’ instance. In this particular case we are only interested in the return value from the final call to ‘start_call’ so we don’t have much configuration to do. Let’s assume the object it returns is ‘file-like’, so we’ll ensure that our response object uses the builtin *note open(): 4f0. as its ‘spec’. To do this we create a mock instance as our mock backend and create a mock response object for it. To set the response as the return value for that final ‘start_call’ we could do this: mock_backend.get_endpoint.return_value.create_call.return_value.start_call.return_value = mock_response We can do that in a slightly nicer way using the *note configure_mock(): 30a1. method to directly set the return value for us: >>> something = Something() >>> mock_response = Mock(spec=open) >>> mock_backend = Mock() >>> config = {'get_endpoint.return_value.create_call.return_value.start_call.return_value': mock_response} >>> mock_backend.configure_mock(**config) With these we monkey patch the “mock backend” in place and can make the real call: >>> something.backend = mock_backend >>> something.method() Using *note mock_calls: 30a6. we can check the chained call with a single assert. A chained call is several calls in one line of code, so there will be several entries in ‘mock_calls’. We can use *note call.call_list(): 30dd. to create this list of calls for us: >>> chained = call.get_endpoint('foobar').create_call('spam', 'eggs').start_call() >>> call_list = chained.call_list() >>> assert mock_backend.mock_calls == call_list  File: python.info, Node: Partial mocking, Next: Mocking a Generator Method, Prev: Mocking chained calls, Up: Further Examples 5.26.6.16 Partial mocking ......................... In some tests I wanted to mock out a call to *note datetime.date.today(): 1551. to return a known date, but I didn’t want to prevent the code under test from creating new date objects. Unfortunately *note datetime.date: 193. is written in C, and so I couldn’t just monkey-patch out the static ‘date.today()’ method. I found a simple way of doing this that involved effectively wrapping the date class with a mock, but passing through calls to the constructor to the real class (and returning real instances). The *note patch decorator: 788. is used here to mock out the ‘date’ class in the module under test. The ‘side_effect’ attribute on the mock date class is then set to a lambda function that returns a real date. When the mock date class is called a real date will be constructed and returned by ‘side_effect’. >>> from datetime import date >>> with patch('mymodule.date') as mock_date: ... mock_date.today.return_value = date(2010, 10, 8) ... mock_date.side_effect = lambda *args, **kw: date(*args, **kw) ... ... assert mymodule.date.today() == date(2010, 10, 8) ... assert mymodule.date(2009, 6, 8) == date(2009, 6, 8) Note that we don’t patch *note datetime.date: 193. globally, we patch ‘date’ in the module that `uses' it. See *note where to patch: 3096. When ‘date.today()’ is called a known date is returned, but calls to the ‘date(...)’ constructor still return normal dates. Without this you can find yourself having to calculate an expected result using exactly the same algorithm as the code under test, which is a classic testing anti-pattern. Calls to the date constructor are recorded in the ‘mock_date’ attributes (‘call_count’ and friends) which may also be useful for your tests. An alternative way of dealing with mocking dates, or other builtin classes, is discussed in this blog entry(1). ---------- Footnotes ---------- (1) https://williambert.online/2011/07/how-to-unit-testing-in-django-with-mocking-and-patching/  File: python.info, Node: Mocking a Generator Method, Next: Applying the same patch to every test method, Prev: Partial mocking, Up: Further Examples 5.26.6.17 Mocking a Generator Method .................................... A Python generator is a function or method that uses the *note yield: 18f. statement to return a series of values when iterated over (1). A generator method / function is called to return the generator object. It is the generator object that is then iterated over. The protocol method for iteration is *note __iter__(): 12d4, so we can mock this using a *note MagicMock: 785. Here’s an example class with an “iter” method implemented as a generator: >>> class Foo: ... def iter(self): ... for i in [1, 2, 3]: ... yield i ... >>> foo = Foo() >>> list(foo.iter()) [1, 2, 3] How would we mock this class, and in particular its “iter” method? To configure the values returned from the iteration (implicit in the call to *note list: 262.), we need to configure the object returned by the call to ‘foo.iter()’. >>> mock_foo = MagicMock() >>> mock_foo.iter.return_value = iter([1, 2, 3]) >>> list(mock_foo.iter()) [1, 2, 3] ---------- Footnotes ---------- (1) (1) There are also generator expressions and more advanced uses (http://www.dabeaz.com/coroutines/index.html) of generators, but we aren’t concerned about them here. A very good introduction to generators and how powerful they are is: Generator Tricks for Systems Programmers (http://www.dabeaz.com/generators/).  File: python.info, Node: Applying the same patch to every test method, Next: Mocking Unbound Methods, Prev: Mocking a Generator Method, Up: Further Examples 5.26.6.18 Applying the same patch to every test method ...................................................... If you want several patches in place for multiple test methods the obvious way is to apply the patch decorators to every method. This can feel like unnecessary repetition. For Python 2.6 or more recent you can use *note patch(): 788. (in all its various forms) as a class decorator. This applies the patches to all test methods on the class. A test method is identified by methods whose names start with ‘test’: >>> @patch('mymodule.SomeClass') ... class MyTest(unittest.TestCase): ... ... def test_one(self, MockSomeClass): ... self.assertIs(mymodule.SomeClass, MockSomeClass) ... ... def test_two(self, MockSomeClass): ... self.assertIs(mymodule.SomeClass, MockSomeClass) ... ... def not_a_test(self): ... return 'something' ... >>> MyTest('test_one').test_one() >>> MyTest('test_two').test_two() >>> MyTest('test_two').not_a_test() 'something' An alternative way of managing patches is to use the *note patch methods; start and stop: 30cf. These allow you to move the patching into your ‘setUp’ and ‘tearDown’ methods. >>> class MyTest(unittest.TestCase): ... def setUp(self): ... self.patcher = patch('mymodule.foo') ... self.mock_foo = self.patcher.start() ... ... def test_foo(self): ... self.assertIs(mymodule.foo, self.mock_foo) ... ... def tearDown(self): ... self.patcher.stop() ... >>> MyTest('test_foo').run() If you use this technique you must ensure that the patching is “undone” by calling ‘stop’. This can be fiddlier than you might think, because if an exception is raised in the setUp then tearDown is not called. *note unittest.TestCase.addCleanup(): 2a2. makes this easier: >>> class MyTest(unittest.TestCase): ... def setUp(self): ... patcher = patch('mymodule.foo') ... self.addCleanup(patcher.stop) ... self.mock_foo = patcher.start() ... ... def test_foo(self): ... self.assertIs(mymodule.foo, self.mock_foo) ... >>> MyTest('test_foo').run()  File: python.info, Node: Mocking Unbound Methods, Next: Checking multiple calls with mock, Prev: Applying the same patch to every test method, Up: Further Examples 5.26.6.19 Mocking Unbound Methods ................................. Whilst writing tests today I needed to patch an `unbound method' (patching the method on the class rather than on the instance). I needed self to be passed in as the first argument because I want to make asserts about which objects were calling this particular method. The issue is that you can’t patch with a mock for this, because if you replace an unbound method with a mock it doesn’t become a bound method when fetched from the instance, and so it doesn’t get self passed in. The workaround is to patch the unbound method with a real function instead. The *note patch(): 788. decorator makes it so simple to patch out methods with a mock that having to create a real function becomes a nuisance. If you pass ‘autospec=True’ to patch then it does the patching with a `real' function object. This function object has the same signature as the one it is replacing, but delegates to a mock under the hood. You still get your mock auto-created in exactly the same way as before. What it means though, is that if you use it to patch out an unbound method on a class the mocked function will be turned into a bound method if it is fetched from an instance. It will have ‘self’ passed in as the first argument, which is exactly what I wanted: >>> class Foo: ... def foo(self): ... pass ... >>> with patch.object(Foo, 'foo', autospec=True) as mock_foo: ... mock_foo.return_value = 'foo' ... foo = Foo() ... foo.foo() ... 'foo' >>> mock_foo.assert_called_once_with(foo) If we don’t use ‘autospec=True’ then the unbound method is patched out with a Mock instance instead, and isn’t called with ‘self’.  File: python.info, Node: Checking multiple calls with mock, Next: Coping with mutable arguments, Prev: Mocking Unbound Methods, Up: Further Examples 5.26.6.20 Checking multiple calls with mock ........................................... mock has a nice API for making assertions about how your mock objects are used. >>> mock = Mock() >>> mock.foo_bar.return_value = None >>> mock.foo_bar('baz', spam='eggs') >>> mock.foo_bar.assert_called_with('baz', spam='eggs') If your mock is only being called once you can use the ‘assert_called_once_with()’ method that also asserts that the ‘call_count’ is one. >>> mock.foo_bar.assert_called_once_with('baz', spam='eggs') >>> mock.foo_bar() >>> mock.foo_bar.assert_called_once_with('baz', spam='eggs') Traceback (most recent call last): ... AssertionError: Expected to be called once. Called 2 times. Both ‘assert_called_with’ and ‘assert_called_once_with’ make assertions about the `most recent' call. If your mock is going to be called several times, and you want to make assertions about `all' those calls you can use *note call_args_list: 30b0.: >>> mock = Mock(return_value=None) >>> mock(1, 2, 3) >>> mock(4, 5, 6) >>> mock() >>> mock.call_args_list [call(1, 2, 3), call(4, 5, 6), call()] The *note call: 30b1. helper makes it easy to make assertions about these calls. You can build up a list of expected calls and compare it to ‘call_args_list’. This looks remarkably similar to the repr of the ‘call_args_list’: >>> expected = [call(1, 2, 3), call(4, 5, 6), call()] >>> mock.call_args_list == expected True  File: python.info, Node: Coping with mutable arguments, Next: Nesting Patches, Prev: Checking multiple calls with mock, Up: Further Examples 5.26.6.21 Coping with mutable arguments ....................................... Another situation is rare, but can bite you, is when your mock is called with mutable arguments. ‘call_args’ and ‘call_args_list’ store `references' to the arguments. If the arguments are mutated by the code under test then you can no longer make assertions about what the values were when the mock was called. Here’s some example code that shows the problem. Imagine the following functions defined in ‘mymodule’: def frob(val): pass def grob(val): "First frob and then clear val" frob(val) val.clear() When we try to test that ‘grob’ calls ‘frob’ with the correct argument look what happens: >>> with patch('mymodule.frob') as mock_frob: ... val = {6} ... mymodule.grob(val) ... >>> val set() >>> mock_frob.assert_called_with({6}) Traceback (most recent call last): ... AssertionError: Expected: (({6},), {}) Called with: ((set(),), {}) One possibility would be for mock to copy the arguments you pass in. This could then cause problems if you do assertions that rely on object identity for equality. Here’s one solution that uses the ‘side_effect’ functionality. If you provide a ‘side_effect’ function for a mock then ‘side_effect’ will be called with the same args as the mock. This gives us an opportunity to copy the arguments and store them for later assertions. In this example I’m using `another' mock to store the arguments so that I can use the mock methods for doing the assertion. Again a helper function sets this up for me. >>> from copy import deepcopy >>> from unittest.mock import Mock, patch, DEFAULT >>> def copy_call_args(mock): ... new_mock = Mock() ... def side_effect(*args, **kwargs): ... args = deepcopy(args) ... kwargs = deepcopy(kwargs) ... new_mock(*args, **kwargs) ... return DEFAULT ... mock.side_effect = side_effect ... return new_mock ... >>> with patch('mymodule.frob') as mock_frob: ... new_mock = copy_call_args(mock_frob) ... val = {6} ... mymodule.grob(val) ... >>> new_mock.assert_called_with({6}) >>> new_mock.call_args call({6}) ‘copy_call_args’ is called with the mock that will be called. It returns a new mock that we do the assertion on. The ‘side_effect’ function makes a copy of the args and calls our ‘new_mock’ with the copy. Note: If your mock is only going to be used once there is an easier way of checking arguments at the point they are called. You can simply do the checking inside a ‘side_effect’ function. >>> def side_effect(arg): ... assert arg == {6} ... >>> mock = Mock(side_effect=side_effect) >>> mock({6}) >>> mock(set()) Traceback (most recent call last): ... AssertionError An alternative approach is to create a subclass of *note Mock: 249. or *note MagicMock: 785. that copies (using *note copy.deepcopy(): 3cc.) the arguments. Here’s an example implementation: >>> from copy import deepcopy >>> class CopyingMock(MagicMock): ... def __call__(self, /, *args, **kwargs): ... args = deepcopy(args) ... kwargs = deepcopy(kwargs) ... return super(CopyingMock, self).__call__(*args, **kwargs) ... >>> c = CopyingMock(return_value=None) >>> arg = set() >>> c(arg) >>> arg.add(1) >>> c.assert_called_with(set()) >>> c.assert_called_with(arg) Traceback (most recent call last): ... AssertionError: Expected call: mock({1}) Actual call: mock(set()) >>> c.foo <CopyingMock name='mock.foo' id='...'> When you subclass ‘Mock’ or ‘MagicMock’ all dynamically created attributes, and the ‘return_value’ will use your subclass automatically. That means all children of a ‘CopyingMock’ will also have the type ‘CopyingMock’.  File: python.info, Node: Nesting Patches, Next: Mocking a dictionary with MagicMock, Prev: Coping with mutable arguments, Up: Further Examples 5.26.6.22 Nesting Patches ......................... Using patch as a context manager is nice, but if you do multiple patches you can end up with nested with statements indenting further and further to the right: >>> class MyTest(unittest.TestCase): ... ... def test_foo(self): ... with patch('mymodule.Foo') as mock_foo: ... with patch('mymodule.Bar') as mock_bar: ... with patch('mymodule.Spam') as mock_spam: ... assert mymodule.Foo is mock_foo ... assert mymodule.Bar is mock_bar ... assert mymodule.Spam is mock_spam ... >>> original = mymodule.Foo >>> MyTest('test_foo').test_foo() >>> assert mymodule.Foo is original With unittest ‘cleanup’ functions and the *note patch methods; start and stop: 30cf. we can achieve the same effect without the nested indentation. A simple helper method, ‘create_patch’, puts the patch in place and returns the created mock for us: >>> class MyTest(unittest.TestCase): ... ... def create_patch(self, name): ... patcher = patch(name) ... thing = patcher.start() ... self.addCleanup(patcher.stop) ... return thing ... ... def test_foo(self): ... mock_foo = self.create_patch('mymodule.Foo') ... mock_bar = self.create_patch('mymodule.Bar') ... mock_spam = self.create_patch('mymodule.Spam') ... ... assert mymodule.Foo is mock_foo ... assert mymodule.Bar is mock_bar ... assert mymodule.Spam is mock_spam ... >>> original = mymodule.Foo >>> MyTest('test_foo').run() >>> assert mymodule.Foo is original  File: python.info, Node: Mocking a dictionary with MagicMock, Next: Mock subclasses and their attributes, Prev: Nesting Patches, Up: Further Examples 5.26.6.23 Mocking a dictionary with MagicMock ............................................. You may want to mock a dictionary, or other container object, recording all access to it whilst having it still behave like a dictionary. We can do this with *note MagicMock: 785, which will behave like a dictionary, and using *note side_effect: 309e. to delegate dictionary access to a real underlying dictionary that is under our control. When the *note __getitem__(): 27c. and *note __setitem__(): c62. methods of our ‘MagicMock’ are called (normal dictionary access) then ‘side_effect’ is called with the key (and in the case of ‘__setitem__’ the value too). We can also control what is returned. After the ‘MagicMock’ has been used we can use attributes like *note call_args_list: 30b0. to assert about how the dictionary was used: >>> my_dict = {'a': 1, 'b': 2, 'c': 3} >>> def getitem(name): ... return my_dict[name] ... >>> def setitem(name, val): ... my_dict[name] = val ... >>> mock = MagicMock() >>> mock.__getitem__.side_effect = getitem >>> mock.__setitem__.side_effect = setitem Note: An alternative to using ‘MagicMock’ is to use ‘Mock’ and `only' provide the magic methods you specifically want: >>> mock = Mock() >>> mock.__getitem__ = Mock(side_effect=getitem) >>> mock.__setitem__ = Mock(side_effect=setitem) A `third' option is to use ‘MagicMock’ but passing in ‘dict’ as the `spec' (or `spec_set') argument so that the ‘MagicMock’ created only has dictionary magic methods available: >>> mock = MagicMock(spec_set=dict) >>> mock.__getitem__.side_effect = getitem >>> mock.__setitem__.side_effect = setitem With these side effect functions in place, the ‘mock’ will behave like a normal dictionary but recording the access. It even raises a *note KeyError: 2c7. if you try to access a key that doesn’t exist. >>> mock['a'] 1 >>> mock['c'] 3 >>> mock['d'] Traceback (most recent call last): ... KeyError: 'd' >>> mock['b'] = 'fish' >>> mock['d'] = 'eggs' >>> mock['b'] 'fish' >>> mock['d'] 'eggs' After it has been used you can make assertions about the access using the normal mock methods and attributes: >>> mock.__getitem__.call_args_list [call('a'), call('c'), call('d'), call('b'), call('d')] >>> mock.__setitem__.call_args_list [call('b', 'fish'), call('d', 'eggs')] >>> my_dict {'a': 1, 'b': 'fish', 'c': 3, 'd': 'eggs'}  File: python.info, Node: Mock subclasses and their attributes, Next: Mocking imports with patch dict, Prev: Mocking a dictionary with MagicMock, Up: Further Examples 5.26.6.24 Mock subclasses and their attributes .............................................. There are various reasons why you might want to subclass *note Mock: 249. One reason might be to add helper methods. Here’s a silly example: >>> class MyMock(MagicMock): ... def has_been_called(self): ... return self.called ... >>> mymock = MyMock(return_value=None) >>> mymock <MyMock id='...'> >>> mymock.has_been_called() False >>> mymock() >>> mymock.has_been_called() True The standard behaviour for ‘Mock’ instances is that attributes and the return value mocks are of the same type as the mock they are accessed on. This ensures that ‘Mock’ attributes are ‘Mocks’ and ‘MagicMock’ attributes are ‘MagicMocks’ (1). So if you’re subclassing to add helper methods then they’ll also be available on the attributes and return value mock of instances of your subclass. >>> mymock.foo <MyMock name='mock.foo' id='...'> >>> mymock.foo.has_been_called() False >>> mymock.foo() <MyMock name='mock.foo()' id='...'> >>> mymock.foo.has_been_called() True Sometimes this is inconvenient. For example, one user(2) is subclassing mock to created a Twisted adaptor(3). Having this applied to attributes too actually causes errors. ‘Mock’ (in all its flavours) uses a method called ‘_get_child_mock’ to create these “sub-mocks” for attributes and return values. You can prevent your subclass being used for attributes by overriding this method. The signature is that it takes arbitrary keyword arguments (‘**kwargs’) which are then passed onto the mock constructor: >>> class Subclass(MagicMock): ... def _get_child_mock(self, /, **kwargs): ... return MagicMock(**kwargs) ... >>> mymock = Subclass() >>> mymock.foo <MagicMock name='mock.foo' id='...'> >>> assert isinstance(mymock, Subclass) >>> assert not isinstance(mymock.foo, Subclass) >>> assert not isinstance(mymock(), Subclass) ---------- Footnotes ---------- (1) (2) An exception to this rule are the non-callable mocks. Attributes use the callable variant because otherwise non-callable mocks couldn’t have callable methods. (2) https://code.google.com/archive/p/mock/issues/105 (3) https://twistedmatrix.com/documents/11.0.0/api/twisted.python.components.html  File: python.info, Node: Mocking imports with patch dict, Next: Tracking order of calls and less verbose call assertions, Prev: Mock subclasses and their attributes, Up: Further Examples 5.26.6.25 Mocking imports with patch.dict ......................................... One situation where mocking can be hard is where you have a local import inside a function. These are harder to mock because they aren’t using an object from the module namespace that we can patch out. Generally local imports are to be avoided. They are sometimes done to prevent circular dependencies, for which there is `usually' a much better way to solve the problem (refactor the code) or to prevent “up front costs” by delaying the import. This can also be solved in better ways than an unconditional local import (store the module as a class or module attribute and only do the import on first use). That aside there is a way to use ‘mock’ to affect the results of an import. Importing fetches an `object' from the *note sys.modules: 1152. dictionary. Note that it fetches an `object', which need not be a module. Importing a module for the first time results in a module object being put in ‘sys.modules’, so usually when you import something you get a module back. This need not be the case however. This means you can use *note patch.dict(): 3097. to `temporarily' put a mock in place in *note sys.modules: 1152. Any imports whilst this patch is active will fetch the mock. When the patch is complete (the decorated function exits, the with statement body is complete or ‘patcher.stop()’ is called) then whatever was there previously will be restored safely. Here’s an example that mocks out the ‘fooble’ module. >>> import sys >>> mock = Mock() >>> with patch.dict('sys.modules', {'fooble': mock}): ... import fooble ... fooble.blob() ... <Mock name='mock.blob()' id='...'> >>> assert 'fooble' not in sys.modules >>> mock.blob.assert_called_once_with() As you can see the ‘import fooble’ succeeds, but on exit there is no ‘fooble’ left in *note sys.modules: 1152. This also works for the ‘from module import name’ form: >>> mock = Mock() >>> with patch.dict('sys.modules', {'fooble': mock}): ... from fooble import blob ... blob.blip() ... <Mock name='mock.blob.blip()' id='...'> >>> mock.blob.blip.assert_called_once_with() With slightly more work you can also mock package imports: >>> mock = Mock() >>> modules = {'package': mock, 'package.module': mock.module} >>> with patch.dict('sys.modules', modules): ... from package.module import fooble ... fooble() ... <Mock name='mock.module.fooble()' id='...'> >>> mock.module.fooble.assert_called_once_with()  File: python.info, Node: Tracking order of calls and less verbose call assertions, Next: More complex argument matching, Prev: Mocking imports with patch dict, Up: Further Examples 5.26.6.26 Tracking order of calls and less verbose call assertions .................................................................. The *note Mock: 249. class allows you to track the `order' of method calls on your mock objects through the *note method_calls: 30a9. attribute. This doesn’t allow you to track the order of calls between separate mock objects, however we can use *note mock_calls: 30a6. to achieve the same effect. Because mocks track calls to child mocks in ‘mock_calls’, and accessing an arbitrary attribute of a mock creates a child mock, we can create our separate mocks from a parent one. Calls to those child mock will then all be recorded, in order, in the ‘mock_calls’ of the parent: >>> manager = Mock() >>> mock_foo = manager.foo >>> mock_bar = manager.bar >>> mock_foo.something() <Mock name='mock.foo.something()' id='...'> >>> mock_bar.other.thing() <Mock name='mock.bar.other.thing()' id='...'> >>> manager.mock_calls [call.foo.something(), call.bar.other.thing()] We can then assert about the calls, including the order, by comparing with the ‘mock_calls’ attribute on the manager mock: >>> expected_calls = [call.foo.something(), call.bar.other.thing()] >>> manager.mock_calls == expected_calls True If ‘patch’ is creating, and putting in place, your mocks then you can attach them to a manager mock using the *note attach_mock(): 30a8. method. After attaching calls will be recorded in ‘mock_calls’ of the manager. >>> manager = MagicMock() >>> with patch('mymodule.Class1') as MockClass1: ... with patch('mymodule.Class2') as MockClass2: ... manager.attach_mock(MockClass1, 'MockClass1') ... manager.attach_mock(MockClass2, 'MockClass2') ... MockClass1().foo() ... MockClass2().bar() <MagicMock name='mock.MockClass1().foo()' id='...'> <MagicMock name='mock.MockClass2().bar()' id='...'> >>> manager.mock_calls [call.MockClass1(), call.MockClass1().foo(), call.MockClass2(), call.MockClass2().bar()] If many calls have been made, but you’re only interested in a particular sequence of them then an alternative is to use the *note assert_has_calls(): 30a5. method. This takes a list of calls (constructed with the *note call: 30b1. object). If that sequence of calls are in *note mock_calls: 30a6. then the assert succeeds. >>> m = MagicMock() >>> m().foo().bar().baz() <MagicMock name='mock().foo().bar().baz()' id='...'> >>> m.one().two().three() <MagicMock name='mock.one().two().three()' id='...'> >>> calls = call.one().two().three().call_list() >>> m.assert_has_calls(calls) Even though the chained call ‘m.one().two().three()’ aren’t the only calls that have been made to the mock, the assert still succeeds. Sometimes a mock may have several calls made to it, and you are only interested in asserting about `some' of those calls. You may not even care about the order. In this case you can pass ‘any_order=True’ to ‘assert_has_calls’: >>> m = MagicMock() >>> m(1), m.two(2, 3), m.seven(7), m.fifty('50') (...) >>> calls = [call.fifty('50'), call(1), call.seven(7)] >>> m.assert_has_calls(calls, any_order=True)  File: python.info, Node: More complex argument matching, Prev: Tracking order of calls and less verbose call assertions, Up: Further Examples 5.26.6.27 More complex argument matching ........................................ Using the same basic concept as *note ANY: 30e0. we can implement matchers to do more complex assertions on objects used as arguments to mocks. Suppose we expect some object to be passed to a mock that by default compares equal based on object identity (which is the Python default for user defined classes). To use *note assert_called_with(): 30a2. we would need to pass in the exact same object. If we are only interested in some of the attributes of this object then we can create a matcher that will check these attributes for us. You can see in this example how a ‘standard’ call to ‘assert_called_with’ isn’t sufficient: >>> class Foo: ... def __init__(self, a, b): ... self.a, self.b = a, b ... >>> mock = Mock(return_value=None) >>> mock(Foo(1, 2)) >>> mock.assert_called_with(Foo(1, 2)) Traceback (most recent call last): ... AssertionError: Expected: call(<__main__.Foo object at 0x...>) Actual call: call(<__main__.Foo object at 0x...>) A comparison function for our ‘Foo’ class might look something like this: >>> def compare(self, other): ... if not type(self) == type(other): ... return False ... if self.a != other.a: ... return False ... if self.b != other.b: ... return False ... return True ... And a matcher object that can use comparison functions like this for its equality operation would look something like this: >>> class Matcher: ... def __init__(self, compare, some_obj): ... self.compare = compare ... self.some_obj = some_obj ... def __eq__(self, other): ... return self.compare(self.some_obj, other) ... Putting all this together: >>> match_foo = Matcher(compare, Foo(1, 2)) >>> mock.assert_called_with(match_foo) The ‘Matcher’ is instantiated with our compare function and the ‘Foo’ object we want to compare against. In ‘assert_called_with’ the ‘Matcher’ equality method will be called, which compares the object the mock was called with against the one we created our matcher with. If they match then ‘assert_called_with’ passes, and if they don’t an *note AssertionError: 1223. is raised: >>> match_wrong = Matcher(compare, Foo(3, 4)) >>> mock.assert_called_with(match_wrong) Traceback (most recent call last): ... AssertionError: Expected: ((<Matcher object at 0x...>,), {}) Called with: ((<Foo object at 0x...>,), {}) With a bit of tweaking you could have the comparison function raise the *note AssertionError: 1223. directly and provide a more useful failure message. As of version 1.5, the Python testing library PyHamcrest(1) provides similar functionality, that may be useful here, in the form of its equality matcher (hamcrest.library.integration.match_equality(2)). ---------- Footnotes ---------- (1) https://pyhamcrest.readthedocs.io/ (2) https://pyhamcrest.readthedocs.io/en/release-1.8/integration/#module-hamcrest.library.integration.match_equality  File: python.info, Node: 2to3 - Automated Python 2 to 3 code translation, Next: test — Regression tests package for Python, Prev: unittest mock — getting started, Up: Development Tools 5.26.7 2to3 - Automated Python 2 to 3 code translation ------------------------------------------------------ 2to3 is a Python program that reads Python 2.x source code and applies a series of `fixers' to transform it into valid Python 3.x code. The standard library contains a rich set of fixers that will handle almost all code. 2to3 supporting library *note lib2to3: a7. is, however, a flexible and generic library, so it is possible to write your own fixers for 2to3. *note lib2to3: a7. could also be adapted to custom applications in which Python code needs to be edited automatically. * Menu: * Using 2to3:: * Fixers:: * lib2to3 - 2to3’s library::  File: python.info, Node: Using 2to3, Next: Fixers, Up: 2to3 - Automated Python 2 to 3 code translation 5.26.7.1 Using 2to3 ................... 2to3 will usually be installed with the Python interpreter as a script. It is also located in the ‘Tools/scripts’ directory of the Python root. 2to3’s basic arguments are a list of files or directories to transform. The directories are recursively traversed for Python sources. Here is a sample Python 2.x source file, ‘example.py’: def greet(name): print "Hello, {0}!".format(name) print "What's your name?" name = raw_input() greet(name) It can be converted to Python 3.x code via 2to3 on the command line: $ 2to3 example.py A diff against the original source file is printed. 2to3 can also write the needed modifications right back to the source file. (A backup of the original file is made unless ‘-n’ is also given.) Writing the changes back is enabled with the ‘-w’ flag: $ 2to3 -w example.py After transformation, ‘example.py’ looks like this: def greet(name): print("Hello, {0}!".format(name)) print("What's your name?") name = input() greet(name) Comments and exact indentation are preserved throughout the translation process. By default, 2to3 runs a set of *note predefined fixers: 3109. The ‘-l’ flag lists all available fixers. An explicit set of fixers to run can be given with ‘-f’. Likewise the ‘-x’ explicitly disables a fixer. The following example runs only the ‘imports’ and ‘has_key’ fixers: $ 2to3 -f imports -f has_key example.py This command runs every fixer except the ‘apply’ fixer: $ 2to3 -x apply example.py Some fixers are `explicit', meaning they aren’t run by default and must be listed on the command line to be run. Here, in addition to the default fixers, the ‘idioms’ fixer is run: $ 2to3 -f all -f idioms example.py Notice how passing ‘all’ enables all default fixers. Sometimes 2to3 will find a place in your source code that needs to be changed, but 2to3 cannot fix automatically. In this case, 2to3 will print a warning beneath the diff for a file. You should address the warning in order to have compliant 3.x code. 2to3 can also refactor doctests. To enable this mode, use the ‘-d’ flag. Note that `only' doctests will be refactored. This also doesn’t require the module to be valid Python. For example, doctest like examples in a reST document could also be refactored with this option. The ‘-v’ option enables output of more information on the translation process. Since some print statements can be parsed as function calls or statements, 2to3 cannot always read files containing the print function. When 2to3 detects the presence of the ‘from __future__ import print_function’ compiler directive, it modifies its internal grammar to interpret *note print(): 886. as a function. This change can also be enabled manually with the ‘-p’ flag. Use ‘-p’ to run fixers on code that already has had its print statements converted. The ‘-o’ or ‘--output-dir’ option allows specification of an alternate directory for processed output files to be written to. The ‘-n’ flag is required when using this as backup files do not make sense when not overwriting the input files. New in version 3.2.3: The ‘-o’ option was added. The ‘-W’ or ‘--write-unchanged-files’ flag tells 2to3 to always write output files even if no changes were required to the file. This is most useful with ‘-o’ so that an entire Python source tree is copied with translation from one directory to another. This option implies the ‘-w’ flag as it would not make sense otherwise. New in version 3.2.3: The ‘-W’ flag was added. The ‘--add-suffix’ option specifies a string to append to all output filenames. The ‘-n’ flag is required when specifying this as backups are not necessary when writing to different filenames. Example: $ 2to3 -n -W --add-suffix=3 example.py Will cause a converted file named ‘example.py3’ to be written. New in version 3.2.3: The ‘--add-suffix’ option was added. To translate an entire project from one directory tree to another use: $ 2to3 --output-dir=python3-version/mycode -W -n python2-version/mycode  File: python.info, Node: Fixers, Next: lib2to3 - 2to3’s library, Prev: Using 2to3, Up: 2to3 - Automated Python 2 to 3 code translation 5.26.7.2 Fixers ............... Each step of transforming code is encapsulated in a fixer. The command ‘2to3 -l’ lists them. As *note documented above: 3107, each can be turned on and off individually. They are described here in more detail. -- 2to3fixer: apply Removes usage of ‘apply()’. For example ‘apply(function, *args, **kwargs)’ is converted to ‘function(*args, **kwargs)’. -- 2to3fixer: asserts Replaces deprecated *note unittest: 11b. method names with the correct ones. From To ------------------------------------------------------------------------------------ ‘failUnlessEqual(a, b)’ *note assertEqual(a, b): bb5. ‘assertEquals(a, b)’ *note assertEqual(a, b): bb5. ‘failIfEqual(a, b)’ *note assertNotEqual(a, b): bb6. ‘assertNotEquals(a, b)’ *note assertNotEqual(a, b): bb6. ‘failUnless(a)’ *note assertTrue(a): bb4. ‘assert_(a)’ *note assertTrue(a): bb4. ‘failIf(a)’ *note assertFalse(a): cc7. ‘failUnlessRaises(exc, cal)’ *note assertRaises(exc, cal): aba. ‘failUnlessAlmostEqual(a, b)’ *note assertAlmostEqual(a, b): bb7. ‘assertAlmostEquals(a, b)’ *note assertAlmostEqual(a, b): bb7. ‘failIfAlmostEqual(a, b)’ *note assertNotAlmostEqual(a, b): bb8. ‘assertNotAlmostEquals(a, b)’ *note assertNotAlmostEqual(a, b): bb8. -- 2to3fixer: basestring Converts ‘basestring’ to *note str: 330. -- 2to3fixer: buffer Converts ‘buffer’ to *note memoryview: 25c. This fixer is optional because the *note memoryview: 25c. API is similar but not exactly the same as that of ‘buffer’. -- 2to3fixer: dict Fixes dictionary iteration methods. ‘dict.iteritems()’ is converted to *note dict.items(): c2b, ‘dict.iterkeys()’ to *note dict.keys(): c2a, and ‘dict.itervalues()’ to *note dict.values(): c2c. Similarly, ‘dict.viewitems()’, ‘dict.viewkeys()’ and ‘dict.viewvalues()’ are converted respectively to *note dict.items(): c2b, *note dict.keys(): c2a. and *note dict.values(): c2c. It also wraps existing usages of *note dict.items(): c2b, *note dict.keys(): c2a, and *note dict.values(): c2c. in a call to *note list: 262. -- 2to3fixer: except Converts ‘except X, T’ to ‘except X as T’. -- 2to3fixer: exec Converts the ‘exec’ statement to the *note exec(): c44. function. -- 2to3fixer: execfile Removes usage of ‘execfile()’. The argument to ‘execfile()’ is wrapped in calls to *note open(): 4f0, *note compile(): 1b4, and *note exec(): c44. -- 2to3fixer: exitfunc Changes assignment of ‘sys.exitfunc’ to use of the *note atexit: c. module. -- 2to3fixer: filter Wraps *note filter(): c2e. usage in a *note list: 262. call. -- 2to3fixer: funcattrs Fixes function attributes that have been renamed. For example, ‘my_function.func_closure’ is converted to ‘my_function.__closure__’. -- 2to3fixer: future Removes ‘from __future__ import new_feature’ statements. -- 2to3fixer: getcwdu Renames ‘os.getcwdu()’ to *note os.getcwd(): 188d. -- 2to3fixer: has_key Changes ‘dict.has_key(key)’ to ‘key in dict’. -- 2to3fixer: idioms This optional fixer performs several transformations that make Python code more idiomatic. Type comparisons like ‘type(x) is SomeClass’ and ‘type(x) == SomeClass’ are converted to ‘isinstance(x, SomeClass)’. ‘while 1’ becomes ‘while True’. This fixer also tries to make use of *note sorted(): 444. in appropriate places. For example, this block L = list(some_iterable) L.sort() is changed to L = sorted(some_iterable) -- 2to3fixer: import Detects sibling imports and converts them to relative imports. -- 2to3fixer: imports Handles module renames in the standard library. -- 2to3fixer: imports2 Handles other modules renames in the standard library. It is separate from the *note imports: 311b. fixer only because of technical limitations. -- 2to3fixer: input Converts ‘input(prompt)’ to ‘eval(input(prompt))’. -- 2to3fixer: intern Converts ‘intern()’ to *note sys.intern(): c6e. -- 2to3fixer: isinstance Fixes duplicate types in the second argument of *note isinstance(): 44f. For example, ‘isinstance(x, (int, int))’ is converted to ‘isinstance(x, int)’ and ‘isinstance(x, (int, float, int))’ is converted to ‘isinstance(x, (int, float))’. -- 2to3fixer: itertools_imports Removes imports of ‘itertools.ifilter()’, ‘itertools.izip()’, and ‘itertools.imap()’. Imports of ‘itertools.ifilterfalse()’ are also changed to *note itertools.filterfalse(): 1296. -- 2to3fixer: itertools Changes usage of ‘itertools.ifilter()’, ‘itertools.izip()’, and ‘itertools.imap()’ to their built-in equivalents. ‘itertools.ifilterfalse()’ is changed to *note itertools.filterfalse(): 1296. -- 2to3fixer: long Renames ‘long’ to *note int: 184. -- 2to3fixer: map Wraps *note map(): c2d. in a *note list: 262. call. It also changes ‘map(None, x)’ to ‘list(x)’. Using ‘from future_builtins import map’ disables this fixer. -- 2to3fixer: metaclass Converts the old metaclass syntax (‘__metaclass__ = Meta’ in the class body) to the new (‘class X(metaclass=Meta)’). -- 2to3fixer: methodattrs Fixes old method attribute names. For example, ‘meth.im_func’ is converted to ‘meth.__func__’. -- 2to3fixer: ne Converts the old not-equal syntax, ‘<>’, to ‘!=’. -- 2to3fixer: next Converts the use of iterator’s ‘next()’ methods to the *note next(): 682. function. It also renames *note next(): 682. methods to *note __next__(): c64. -- 2to3fixer: nonzero Renames ‘__nonzero__()’ to *note __bool__(): c68. -- 2to3fixer: numliterals Converts octal literals into the new syntax. -- 2to3fixer: operator Converts calls to various functions in the *note operator: c2. module to other, but equivalent, function calls. When needed, the appropriate ‘import’ statements are added, e.g. ‘import collections.abc’. The following mapping are made: From To ----------------------------------------------------------------------------------------- ‘operator.isCallable(obj)’ ‘callable(obj)’ ‘operator.sequenceIncludes(obj)’ ‘operator.contains(obj)’ ‘operator.isSequenceType(obj)’ ‘isinstance(obj, collections.abc.Sequence)’ ‘operator.isMappingType(obj)’ ‘isinstance(obj, collections.abc.Mapping)’ ‘operator.isNumberType(obj)’ ‘isinstance(obj, numbers.Number)’ ‘operator.repeat(obj, n)’ ‘operator.mul(obj, n)’ ‘operator.irepeat(obj, n)’ ‘operator.imul(obj, n)’ -- 2to3fixer: paren Add extra parenthesis where they are required in list comprehensions. For example, ‘[x for x in 1, 2]’ becomes ‘[x for x in (1, 2)]’. -- 2to3fixer: print Converts the ‘print’ statement to the *note print(): 886. function. -- 2to3fixer: raise Converts ‘raise E, V’ to ‘raise E(V)’, and ‘raise E, V, T’ to ‘raise E(V).with_traceback(T)’. If ‘E’ is a tuple, the translation will be incorrect because substituting tuples for exceptions has been removed in 3.0. -- 2to3fixer: raw_input Converts ‘raw_input()’ to *note input(): c6b. -- 2to3fixer: reduce Handles the move of ‘reduce()’ to *note functools.reduce(): c6f. -- 2to3fixer: reload Converts ‘reload()’ to *note importlib.reload(): 399. -- 2to3fixer: renames Changes ‘sys.maxint’ to *note sys.maxsize: b43. -- 2to3fixer: repr Replaces backtick repr with the *note repr(): 7cc. function. -- 2to3fixer: set_literal Replaces use of the *note set: b6f. constructor with set literals. This fixer is optional. -- 2to3fixer: standarderror Renames ‘StandardError’ to *note Exception: 1a9. -- 2to3fixer: sys_exc Changes the deprecated ‘sys.exc_value’, ‘sys.exc_type’, ‘sys.exc_traceback’ to use *note sys.exc_info(): c5f. -- 2to3fixer: throw Fixes the API change in generator’s ‘throw()’ method. -- 2to3fixer: tuple_params Removes implicit tuple parameter unpacking. This fixer inserts temporary variables. -- 2to3fixer: types Fixes code broken from the removal of some members in the *note types: 118. module. -- 2to3fixer: unicode Renames ‘unicode’ to *note str: 330. -- 2to3fixer: urllib Handles the rename of *note urllib: 11d. and ‘urllib2’ to the *note urllib: 11d. package. -- 2to3fixer: ws_comma Removes excess whitespace from comma separated items. This fixer is optional. -- 2to3fixer: xrange Renames ‘xrange()’ to *note range(): 9be. and wraps existing *note range(): 9be. calls with *note list: 262. -- 2to3fixer: xreadlines Changes ‘for x in file.xreadlines()’ to ‘for x in file’. -- 2to3fixer: zip Wraps *note zip(): c32. usage in a *note list: 262. call. This is disabled when ‘from future_builtins import zip’ appears.  File: python.info, Node: lib2to3 - 2to3’s library, Prev: Fixers, Up: 2to3 - Automated Python 2 to 3 code translation 5.26.7.3 ‘lib2to3’ - 2to3’s library ................................... `Source code:' Lib/lib2to3/(1) __________________________________________________________________ Note: The *note lib2to3: a7. API should be considered unstable and may change drastically in the future. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/lib2to3/  File: python.info, Node: test — Regression tests package for Python, Next: test support — Utilities for the Python test suite, Prev: 2to3 - Automated Python 2 to 3 code translation, Up: Development Tools 5.26.8 ‘test’ — Regression tests package for Python --------------------------------------------------- Note: The *note test: 105. package is meant for internal use by Python only. It is documented for the benefit of the core developers of Python. Any use of this package outside of Python’s standard library is discouraged as code mentioned here can change or be removed without notice between releases of Python. __________________________________________________________________ The *note test: 105. package contains all regression tests for Python as well as the modules *note test.support: 106. and ‘test.regrtest’. *note test.support: 106. is used to enhance your tests while ‘test.regrtest’ drives the testing suite. Each module in the *note test: 105. package whose name starts with ‘test_’ is a testing suite for a specific module or feature. All new tests should be written using the *note unittest: 11b. or *note doctest: 67. module. Some older tests are written using a “traditional” testing style that compares output printed to ‘sys.stdout’; this style of test is considered deprecated. See also ........ Module *note unittest: 11b. Writing PyUnit regression tests. Module *note doctest: 67. Tests embedded in documentation strings. * Menu: * Writing Unit Tests for the test package:: * Running tests using the command-line interface::  File: python.info, Node: Writing Unit Tests for the test package, Next: Running tests using the command-line interface, Up: test — Regression tests package for Python 5.26.8.1 Writing Unit Tests for the ‘test’ package .................................................. It is preferred that tests that use the *note unittest: 11b. module follow a few guidelines. One is to name the test module by starting it with ‘test_’ and end it with the name of the module being tested. The test methods in the test module should start with ‘test_’ and end with a description of what the method is testing. This is needed so that the methods are recognized by the test driver as test methods. Also, no documentation string for the method should be included. A comment (such as ‘# Tests function returns only True or False’) should be used to provide documentation for test methods. This is done because documentation strings get printed out if they exist and thus what test is being run is not stated. A basic boilerplate is often used: import unittest from test import support class MyTestCase1(unittest.TestCase): # Only use setUp() and tearDown() if necessary def setUp(self): ... code to execute in preparation for tests ... def tearDown(self): ... code to execute to clean up after tests ... def test_feature_one(self): # Test feature one. ... testing code ... def test_feature_two(self): # Test feature two. ... testing code ... ... more test methods ... class MyTestCase2(unittest.TestCase): ... same structure as MyTestCase1 ... ... more test classes ... if __name__ == '__main__': unittest.main() This code pattern allows the testing suite to be run by ‘test.regrtest’, on its own as a script that supports the *note unittest: 11b. CLI, or via the ‘python -m unittest’ CLI. The goal for regression testing is to try to break code. This leads to a few guidelines to be followed: * The testing suite should exercise all classes, functions, and constants. This includes not just the external API that is to be presented to the outside world but also “private” code. * Whitebox testing (examining the code being tested when the tests are being written) is preferred. Blackbox testing (testing only the published user interface) is not complete enough to make sure all boundary and edge cases are tested. * Make sure all possible values are tested including invalid ones. This makes sure that not only all valid values are acceptable but also that improper values are handled correctly. * Exhaust as many code paths as possible. Test where branching occurs and thus tailor input to make sure as many different paths through the code are taken. * Add an explicit test for any bugs discovered for the tested code. This will make sure that the error does not crop up again if the code is changed in the future. * Make sure to clean up after your tests (such as close and remove all temporary files). * If a test is dependent on a specific condition of the operating system then verify the condition already exists before attempting the test. * Import as few modules as possible and do it as soon as possible. This minimizes external dependencies of tests and also minimizes possible anomalous behavior from side-effects of importing a module. * Try to maximize code reuse. On occasion, tests will vary by something as small as what type of input is used. Minimize code duplication by subclassing a basic test class with a class that specifies the input: class TestFuncAcceptsSequencesMixin: func = mySuperWhammyFunction def test_func(self): self.func(self.arg) class AcceptLists(TestFuncAcceptsSequencesMixin, unittest.TestCase): arg = [1, 2, 3] class AcceptStrings(TestFuncAcceptsSequencesMixin, unittest.TestCase): arg = 'abc' class AcceptTuples(TestFuncAcceptsSequencesMixin, unittest.TestCase): arg = (1, 2, 3) When using this pattern, remember that all classes that inherit from *note unittest.TestCase: 8ff. are run as tests. The ‘Mixin’ class in the example above does not have any data and so can’t be run by itself, thus it does not inherit from *note unittest.TestCase: 8ff. See also ........ Test Driven Development A book by Kent Beck on writing tests before code.  File: python.info, Node: Running tests using the command-line interface, Prev: Writing Unit Tests for the test package, Up: test — Regression tests package for Python 5.26.8.2 Running tests using the command-line interface ....................................................... The *note test: 105. package can be run as a script to drive Python’s regression test suite, thanks to the *note -m: 337. option: ‘python -m test’. Under the hood, it uses ‘test.regrtest’; the call ‘python -m test.regrtest’ used in previous Python versions still works. Running the script by itself automatically starts running all regression tests in the *note test: 105. package. It does this by finding all modules in the package whose name starts with ‘test_’, importing them, and executing the function ‘test_main()’ if present or loading the tests via unittest.TestLoader.loadTestsFromModule if ‘test_main’ does not exist. The names of tests to execute may also be passed to the script. Specifying a single regression test (‘python -m test test_spam’) will minimize output and only print whether the test passed or failed. Running *note test: 105. directly allows what resources are available for tests to use to be set. You do this by using the ‘-u’ command-line option. Specifying ‘all’ as the value for the ‘-u’ option enables all possible resources: ‘python -m test -uall’. If all but one resource is desired (a more common case), a comma-separated list of resources that are not desired may be listed after ‘all’. The command ‘python -m test -uall,-audio,-largefile’ will run *note test: 105. with all resources except the ‘audio’ and ‘largefile’ resources. For a list of all resources and more command-line options, run ‘python -m test -h’. Some other ways to execute the regression tests depend on what platform the tests are being executed on. On Unix, you can run ‘make test’ at the top-level directory where Python was built. On Windows, executing ‘rt.bat’ from your ‘PCbuild’ directory will run all regression tests.  File: python.info, Node: test support — Utilities for the Python test suite, Next: test support script_helper — Utilities for the Python execution tests, Prev: test — Regression tests package for Python, Up: Development Tools 5.26.9 ‘test.support’ — Utilities for the Python test suite ----------------------------------------------------------- The *note test.support: 106. module provides support for Python’s regression test suite. Note: *note test.support: 106. is not a public module. It is documented here to help Python developers write tests. The API of this module is subject to change without backwards compatibility concerns between releases. This module defines the following exceptions: -- Exception: test.support.TestFailed Exception to be raised when a test fails. This is deprecated in favor of *note unittest: 11b.-based tests and *note unittest.TestCase: 8ff.’s assertion methods. -- Exception: test.support.ResourceDenied Subclass of *note unittest.SkipTest: 903. Raised when a resource (such as a network connection) is not available. Raised by the *note requires(): 3148. function. The *note test.support: 106. module defines the following constants: -- Data: test.support.verbose ‘True’ when verbose output is enabled. Should be checked when more detailed information is desired about a running test. `verbose' is set by ‘test.regrtest’. -- Data: test.support.is_jython ‘True’ if the running interpreter is Jython. -- Data: test.support.is_android ‘True’ if the system is Android. -- Data: test.support.unix_shell Path for shell if not on Windows; otherwise ‘None’. -- Data: test.support.FS_NONASCII A non-ASCII character encodable by *note os.fsencode(): 4ef. -- Data: test.support.TESTFN Set to a name that is safe to use as the name of a temporary file. Any temporary file that is created should be closed and unlinked (removed). -- Data: test.support.TESTFN_UNICODE Set to a non-ASCII name for a temporary file. -- Data: test.support.TESTFN_ENCODING Set to *note sys.getfilesystemencoding(): 4f6. -- Data: test.support.TESTFN_UNENCODABLE Set to a filename (str type) that should not be able to be encoded by file system encoding in strict mode. It may be ‘None’ if it’s not possible to generate such a filename. -- Data: test.support.TESTFN_UNDECODABLE Set to a filename (bytes type) that should not be able to be decoded by file system encoding in strict mode. It may be ‘None’ if it’s not possible to generate such a filename. -- Data: test.support.TESTFN_NONASCII Set to a filename containing the *note FS_NONASCII: 314d. character. -- Data: test.support.IPV6_ENABLED Set to ‘True’ if IPV6 is enabled on this host, ‘False’ otherwise. -- Data: test.support.SAVEDCWD Set to *note os.getcwd(): 188d. -- Data: test.support.PGO Set when tests can be skipped when they are not useful for PGO. -- Data: test.support.PIPE_MAX_SIZE A constant that is likely larger than the underlying OS pipe buffer size, to make writes blocking. -- Data: test.support.SOCK_MAX_SIZE A constant that is likely larger than the underlying OS socket buffer size, to make writes blocking. -- Data: test.support.TEST_SUPPORT_DIR Set to the top level directory that contains *note test.support: 106. -- Data: test.support.TEST_HOME_DIR Set to the top level directory for the test package. -- Data: test.support.TEST_DATA_DIR Set to the ‘data’ directory within the test package. -- Data: test.support.MAX_Py_ssize_t Set to *note sys.maxsize: b43. for big memory tests. -- Data: test.support.max_memuse Set by *note set_memlimit(): 315e. as the memory limit for big memory tests. Limited by *note MAX_Py_ssize_t: 315c. -- Data: test.support.real_max_memuse Set by *note set_memlimit(): 315e. as the memory limit for big memory tests. Not limited by *note MAX_Py_ssize_t: 315c. -- Data: test.support.MISSING_C_DOCSTRINGS Return ‘True’ if running on CPython, not on Windows, and configuration not set with ‘WITH_DOC_STRINGS’. -- Data: test.support.HAVE_DOCSTRINGS Check for presence of docstrings. -- Data: test.support.TEST_HTTP_URL Define the URL of a dedicated HTTP server for the network tests. -- Data: test.support.ALWAYS_EQ Object that is equal to anything. Used to test mixed type comparison. -- Data: test.support.LARGEST Object that is greater than anything (except itself). Used to test mixed type comparison. -- Data: test.support.SMALLEST Object that is less than anything (except itself). Used to test mixed type comparison. The *note test.support: 106. module defines the following functions: -- Function: test.support.forget (module_name) Remove the module named `module_name' from ‘sys.modules’ and delete any byte-compiled files of the module. -- Function: test.support.unload (name) Delete `name' from ‘sys.modules’. -- Function: test.support.unlink (filename) Call *note os.unlink(): a3c. on `filename'. On Windows platforms, this is wrapped with a wait loop that checks for the existence fo the file. -- Function: test.support.rmdir (filename) Call *note os.rmdir(): a3a. on `filename'. On Windows platforms, this is wrapped with a wait loop that checks for the existence of the file. -- Function: test.support.rmtree (path) Call *note shutil.rmtree(): 21c. on `path' or call *note os.lstat(): 1f2. and *note os.rmdir(): a3a. to remove a path and its contents. On Windows platforms, this is wrapped with a wait loop that checks for the existence of the files. -- Function: test.support.make_legacy_pyc (source) Move a PEP 3147(1)/ PEP 488(2) pyc file to its legacy pyc location and return the file system path to the legacy pyc file. The `source' value is the file system path to the source file. It does not need to exist, however the PEP 3147/488 pyc file must exist. -- Function: test.support.is_resource_enabled (resource) Return ‘True’ if `resource' is enabled and available. The list of available resources is only set when ‘test.regrtest’ is executing the tests. -- Function: test.support.python_is_optimized () Return ‘True’ if Python was not built with ‘-O0’ or ‘-Og’. -- Function: test.support.with_pymalloc () Return ‘_testcapi.WITH_PYMALLOC’. -- Function: test.support.requires (resource, msg=None) Raise *note ResourceDenied: 3147. if `resource' is not available. `msg' is the argument to *note ResourceDenied: 3147. if it is raised. Always returns ‘True’ if called by a function whose ‘__name__’ is ‘'__main__'’. Used when tests are executed by ‘test.regrtest’. -- Function: test.support.system_must_validate_cert (f) Raise *note unittest.SkipTest: 903. on TLS certification validation failures. -- Function: test.support.sortdict (dict) Return a repr of `dict' with keys sorted. -- Function: test.support.findfile (filename, subdir=None) Return the path to the file named `filename'. If no match is found `filename' is returned. This does not equal a failure since it could be the path to the file. Setting `subdir' indicates a relative path to use to find the file rather than looking directly in the path directories. -- Function: test.support.create_empty_file (filename) Create an empty file with `filename'. If it already exists, truncate it. -- Function: test.support.fd_count () Count the number of open file descriptors. -- Function: test.support.match_test (test) Match `test' to patterns set in *note set_match_tests(): 3175. -- Function: test.support.set_match_tests (patterns) Define match test with regular expression `patterns'. -- Function: test.support.run_unittest (*classes) Execute *note unittest.TestCase: 8ff. subclasses passed to the function. The function scans the classes for methods starting with the prefix ‘test_’ and executes the tests individually. It is also legal to pass strings as parameters; these should be keys in ‘sys.modules’. Each associated module will be scanned by ‘unittest.TestLoader.loadTestsFromModule()’. This is usually seen in the following ‘test_main()’ function: def test_main(): support.run_unittest(__name__) This will run all tests defined in the named module. -- Function: test.support.run_doctest (module, verbosity=None, optionflags=0) Run *note doctest.testmod(): dd0. on the given `module'. Return ‘(failure_count, test_count)’. If `verbosity' is ‘None’, *note doctest.testmod(): dd0. is run with verbosity set to *note verbose: 3149. Otherwise, it is run with verbosity set to ‘None’. `optionflags' is passed as ‘optionflags’ to *note doctest.testmod(): dd0. -- Function: test.support.setswitchinterval (interval) Set the *note sys.setswitchinterval(): beb. to the given `interval'. Defines a minimum interval for Android systems to prevent the system from hanging. -- Function: test.support.check_impl_detail (**guards) Use this check to guard CPython’s implementation-specific tests or to run them only on the implementations guarded by the arguments: check_impl_detail() # Only on CPython (default). check_impl_detail(jython=True) # Only on Jython. check_impl_detail(cpython=False) # Everywhere except CPython. -- Function: test.support.check_warnings (*filters, quiet=True) A convenience wrapper for *note warnings.catch_warnings(): 317b. that makes it easier to test that a warning was correctly raised. It is approximately equivalent to calling ‘warnings.catch_warnings(record=True)’ with *note warnings.simplefilter(): 317c. set to ‘always’ and with the option to automatically validate the results that are recorded. ‘check_warnings’ accepts 2-tuples of the form ‘("message regexp", WarningCategory)’ as positional arguments. If one or more `filters' are provided, or if the optional keyword argument `quiet' is ‘False’, it checks to make sure the warnings are as expected: each specified filter must match at least one of the warnings raised by the enclosed code or the test fails, and if any warnings are raised that do not match any of the specified filters the test fails. To disable the first of these checks, set `quiet' to ‘True’. If no arguments are specified, it defaults to: check_warnings(("", Warning), quiet=True) In this case all warnings are caught and no errors are raised. On entry to the context manager, a ‘WarningRecorder’ instance is returned. The underlying warnings list from *note catch_warnings(): 317b. is available via the recorder object’s *note warnings: 126. attribute. As a convenience, the attributes of the object representing the most recent warning can also be accessed directly through the recorder object (see example below). If no warning has been raised, then any of the attributes that would otherwise be expected on an object representing a warning will return ‘None’. The recorder object also has a ‘reset()’ method, which clears the warnings list. The context manager is designed to be used like this: with check_warnings(("assertion is always true", SyntaxWarning), ("", UserWarning)): exec('assert(False, "Hey!")') warnings.warn(UserWarning("Hide me!")) In this case if either warning was not raised, or some other warning was raised, *note check_warnings(): 317a. would raise an error. When a test needs to look more deeply into the warnings, rather than just checking whether or not they occurred, code like this can be used: with check_warnings(quiet=True) as w: warnings.warn("foo") assert str(w.args[0]) == "foo" warnings.warn("bar") assert str(w.args[0]) == "bar" assert str(w.warnings[0].args[0]) == "foo" assert str(w.warnings[1].args[0]) == "bar" w.reset() assert len(w.warnings) == 0 Here all warnings will be caught, and the test code tests the captured warnings directly. Changed in version 3.2: New optional arguments `filters' and `quiet'. -- Function: test.support.check_no_resource_warning (testcase) Context manager to check that no *note ResourceWarning: 4d0. was raised. You must remove the object which may emit *note ResourceWarning: 4d0. before the end of the context manager. -- Function: test.support.set_memlimit (limit) Set the values for *note max_memuse: 315d. and *note real_max_memuse: 315f. for big memory tests. -- Function: test.support.record_original_stdout (stdout) Store the value from `stdout'. It is meant to hold the stdout at the time the regrtest began. -- Function: test.support.get_original_stdout () Return the original stdout set by *note record_original_stdout(): 317e. or ‘sys.stdout’ if it’s not set. -- Function: test.support.strip_python_strerr (stderr) Strip the `stderr' of a Python process from potential debug output emitted by the interpreter. This will typically be run on the result of *note subprocess.Popen.communicate(): 2142. -- Function: test.support.args_from_interpreter_flags () Return a list of command line arguments reproducing the current settings in ‘sys.flags’ and ‘sys.warnoptions’. -- Function: test.support.optim_args_from_interpreter_flags () Return a list of command line arguments reproducing the current optimization settings in ‘sys.flags’. -- Function: test.support.captured_stdin () -- Function: test.support.captured_stdout () -- Function: test.support.captured_stderr () A context managers that temporarily replaces the named stream with *note io.StringIO: 82d. object. Example use with output streams: with captured_stdout() as stdout, captured_stderr() as stderr: print("hello") print("error", file=sys.stderr) assert stdout.getvalue() == "hello\n" assert stderr.getvalue() == "error\n" Example use with input stream: with captured_stdin() as stdin: stdin.write('hello\n') stdin.seek(0) # call test code that consumes from sys.stdin captured = input() self.assertEqual(captured, "hello") -- Function: test.support.temp_dir (path=None, quiet=False) A context manager that creates a temporary directory at `path' and yields the directory. If `path' is ‘None’, the temporary directory is created using *note tempfile.mkdtemp(): 1927. If `quiet' is ‘False’, the context manager raises an exception on error. Otherwise, if `path' is specified and cannot be created, only a warning is issued. -- Function: test.support.change_cwd (path, quiet=False) A context manager that temporarily changes the current working directory to `path' and yields the directory. If `quiet' is ‘False’, the context manager raises an exception on error. Otherwise, it issues only a warning and keeps the current working directory the same. -- Function: test.support.temp_cwd (name='tempcwd', quiet=False) A context manager that temporarily creates a new directory and changes the current working directory (CWD). The context manager creates a temporary directory in the current directory with name `name' before temporarily changing the current working directory. If `name' is ‘None’, the temporary directory is created using *note tempfile.mkdtemp(): 1927. If `quiet' is ‘False’ and it is not possible to create or change the CWD, an error is raised. Otherwise, only a warning is raised and the original CWD is used. -- Function: test.support.temp_umask (umask) A context manager that temporarily sets the process umask. -- Function: test.support.transient_internet (resource_name, *, timeout=30.0, errnos=()) A context manager that raises *note ResourceDenied: 3147. when various issues with the internet connection manifest themselves as exceptions. -- Function: test.support.disable_faulthandler () A context manager that replaces ‘sys.stderr’ with ‘sys.__stderr__’. -- Function: test.support.gc_collect () Force as many objects as possible to be collected. This is needed because timely deallocation is not guaranteed by the garbage collector. This means that ‘__del__’ methods may be called later than expected and weakrefs may remain alive for longer than expected. -- Function: test.support.disable_gc () A context manager that disables the garbage collector upon entry and reenables it upon exit. -- Function: test.support.swap_attr (obj, attr, new_val) Context manager to swap out an attribute with a new object. Usage: with swap_attr(obj, "attr", 5): ... This will set ‘obj.attr’ to 5 for the duration of the ‘with’ block, restoring the old value at the end of the block. If ‘attr’ doesn’t exist on ‘obj’, it will be created and then deleted at the end of the block. The old value (or ‘None’ if it doesn’t exist) will be assigned to the target of the “as” clause, if there is one. -- Function: test.support.swap_item (obj, attr, new_val) Context manager to swap out an item with a new object. Usage: with swap_item(obj, "item", 5): ... This will set ‘obj["item"]’ to 5 for the duration of the ‘with’ block, restoring the old value at the end of the block. If ‘item’ doesn’t exist on ‘obj’, it will be created and then deleted at the end of the block. The old value (or ‘None’ if it doesn’t exist) will be assigned to the target of the “as” clause, if there is one. -- Function: test.support.wait_threads_exit (timeout=60.0) Context manager to wait until all threads created in the ‘with’ statement exit. -- Function: test.support.start_threads (threads, unlock=None) Context manager to start `threads'. It attempts to join the threads upon exit. -- Function: test.support.calcobjsize (fmt) Return *note struct.calcsize(): 14b8. for ‘nP{fmt}0n’ or, if ‘gettotalrefcount’ exists, ‘2PnP{fmt}0P’. -- Function: test.support.calcvobjsize (fmt) Return *note struct.calcsize(): 14b8. for ‘nPn{fmt}0n’ or, if ‘gettotalrefcount’ exists, ‘2PnPn{fmt}0P’. -- Function: test.support.checksizeof (test, o, size) For testcase `test', assert that the ‘sys.getsizeof’ for `o' plus the GC header size equals `size'. -- Function: test.support.can_symlink () Return ‘True’ if the OS supports symbolic links, ‘False’ otherwise. -- Function: test.support.can_xattr () Return ‘True’ if the OS supports xattr, ‘False’ otherwise. -- Function: @test.support.skip_unless_symlink A decorator for running tests that require support for symbolic links. -- Function: @test.support.skip_unless_xattr A decorator for running tests that require support for xattr. -- Function: @test.support.skip_unless_bind_unix_socket A decorator for running tests that require a functional bind() for Unix sockets. -- Function: @test.support.anticipate_failure (condition) A decorator to conditionally mark tests with *note unittest.expectedFailure(): 3049. Any use of this decorator should have an associated comment identifying the relevant tracker issue. -- Function: @test.support.run_with_locale (catstr, *locales) A decorator for running a function in a different locale, correctly resetting it after it has finished. `catstr' is the locale category as a string (for example ‘"LC_ALL"’). The `locales' passed will be tried sequentially, and the first valid locale will be used. -- Function: @test.support.run_with_tz (tz) A decorator for running a function in a specific timezone, correctly resetting it after it has finished. -- Function: @test.support.requires_freebsd_version (*min_version) Decorator for the minimum version when running test on FreeBSD. If the FreeBSD version is less than the minimum, raise *note unittest.SkipTest: 903. -- Function: @test.support.requires_linux_version (*min_version) Decorator for the minimum version when running test on Linux. If the Linux version is less than the minimum, raise *note unittest.SkipTest: 903. -- Function: @test.support.requires_mac_version (*min_version) Decorator for the minimum version when running test on Mac OS X. If the MAC OS X version is less than the minimum, raise *note unittest.SkipTest: 903. -- Function: @test.support.requires_IEEE_754 Decorator for skipping tests on non-IEEE 754 platforms. -- Function: @test.support.requires_zlib Decorator for skipping tests if *note zlib: 144. doesn’t exist. -- Function: @test.support.requires_gzip Decorator for skipping tests if *note gzip: 8c. doesn’t exist. -- Function: @test.support.requires_bz2 Decorator for skipping tests if *note bz2: 14. doesn’t exist. -- Function: @test.support.requires_lzma Decorator for skipping tests if *note lzma: ad. doesn’t exist. -- Function: @test.support.requires_resource (resource) Decorator for skipping tests if `resource' is not available. -- Function: @test.support.requires_docstrings Decorator for only running the test if *note HAVE_DOCSTRINGS: 3161. -- Function: @test.support.cpython_only (test) Decorator for tests only applicable to CPython. -- Function: @test.support.impl_detail (msg=None, **guards) Decorator for invoking *note check_impl_detail(): 3179. on `guards'. If that returns ‘False’, then uses `msg' as the reason for skipping the test. -- Function: @test.support.no_tracing (func) Decorator to temporarily turn off tracing for the duration of the test. -- Function: @test.support.refcount_test (test) Decorator for tests which involve reference counting. The decorator does not run the test if it is not run by CPython. Any trace function is unset for the duration of the test to prevent unexpected refcounts caused by the trace function. -- Function: @test.support.reap_threads (func) Decorator to ensure the threads are cleaned up even if the test fails. -- Function: @test.support.bigmemtest (size, memuse, dry_run=True) Decorator for bigmem tests. `size' is a requested size for the test (in arbitrary, test-interpreted units.) `memuse' is the number of bytes per unit for the test, or a good estimate of it. For example, a test that needs two byte buffers, of 4 GiB each, could be decorated with ‘@bigmemtest(size=_4G, memuse=2)’. The `size' argument is normally passed to the decorated test method as an extra argument. If `dry_run' is ‘True’, the value passed to the test method may be less than the requested value. If `dry_run' is ‘False’, it means the test doesn’t support dummy runs when ‘-M’ is not specified. -- Function: @test.support.bigaddrspacetest (f) Decorator for tests that fill the address space. `f' is the function to wrap. -- Function: test.support.make_bad_fd () Create an invalid file descriptor by opening and closing a temporary file, and returning its descriptor. -- Function: test.support.check_syntax_error (testcase, statement, errtext='', *, lineno=None, offset=None) Test for syntax errors in `statement' by attempting to compile `statement'. `testcase' is the *note unittest: 11b. instance for the test. `errtext' is the regular expression which should match the string representation of the raised *note SyntaxError: 458. If `lineno' is not ‘None’, compares to the line of the exception. If `offset' is not ‘None’, compares to the offset of the exception. -- Function: test.support.check_syntax_warning (testcase, statement, errtext='', *, lineno=1, offset=None) Test for syntax warning in `statement' by attempting to compile `statement'. Test also that the *note SyntaxWarning: 191. is emitted only once, and that it will be converted to a *note SyntaxError: 458. when turned into error. `testcase' is the *note unittest: 11b. instance for the test. `errtext' is the regular expression which should match the string representation of the emitted *note SyntaxWarning: 191. and raised *note SyntaxError: 458. If `lineno' is not ‘None’, compares to the line of the warning and exception. If `offset' is not ‘None’, compares to the offset of the exception. New in version 3.8. -- Function: test.support.open_urlresource (url, *args, **kw) Open `url'. If open fails, raises *note TestFailed: 3146. -- Function: test.support.import_module (name, deprecated=False, *, required_on()) This function imports and returns the named module. Unlike a normal import, this function raises *note unittest.SkipTest: 903. if the module cannot be imported. Module and package deprecation messages are suppressed during this import if `deprecated' is ‘True’. If a module is required on a platform but optional for others, set `required_on' to an iterable of platform prefixes which will be compared against *note sys.platform: 2b1. New in version 3.1. -- Function: test.support.import_fresh_module (name, fresh=(), blocked=(), deprecated=False) This function imports and returns a fresh copy of the named Python module by removing the named module from ‘sys.modules’ before doing the import. Note that unlike ‘reload()’, the original module is not affected by this operation. `fresh' is an iterable of additional module names that are also removed from the ‘sys.modules’ cache before doing the import. `blocked' is an iterable of module names that are replaced with ‘None’ in the module cache during the import to ensure that attempts to import them raise *note ImportError: 334. The named module and any modules named in the `fresh' and `blocked' parameters are saved before starting the import and then reinserted into ‘sys.modules’ when the fresh import is complete. Module and package deprecation messages are suppressed during this import if `deprecated' is ‘True’. This function will raise *note ImportError: 334. if the named module cannot be imported. Example use: # Get copies of the warnings module for testing without affecting the # version being used by the rest of the test suite. One copy uses the # C implementation, the other is forced to use the pure Python fallback # implementation py_warnings = import_fresh_module('warnings', blocked=['_warnings']) c_warnings = import_fresh_module('warnings', fresh=['_warnings']) New in version 3.1. -- Function: test.support.modules_setup () Return a copy of *note sys.modules: 1152. -- Function: test.support.modules_cleanup (oldmodules) Remove modules except for `oldmodules' and ‘encodings’ in order to preserve internal cache. -- Function: test.support.threading_setup () Return current thread count and copy of dangling threads. -- Function: test.support.threading_cleanup (*original_values) Cleanup up threads not specified in `original_values'. Designed to emit a warning if a test leaves running threads in the background. -- Function: test.support.join_thread (thread, timeout=30.0) Join a `thread' within `timeout'. Raise an *note AssertionError: 1223. if thread is still alive after `timeout' seconds. -- Function: test.support.reap_children () Use this at the end of ‘test_main’ whenever sub-processes are started. This will help ensure that no extra children (zombies) stick around to hog resources and create problems when looking for refleaks. -- Function: test.support.get_attribute (obj, name) Get an attribute, raising *note unittest.SkipTest: 903. if *note AttributeError: 39b. is raised. -- Function: test.support.bind_port (sock, host=HOST) Bind the socket to a free port and return the port number. Relies on ephemeral ports in order to ensure we are using an unbound port. This is important as many tests may be running simultaneously, especially in a buildbot environment. This method raises an exception if the ‘sock.family’ is *note AF_INET: 229d. and ‘sock.type’ is *note SOCK_STREAM: c8a, and the socket has ‘SO_REUSEADDR’ or ‘SO_REUSEPORT’ set on it. Tests should never set these socket options for TCP/IP sockets. The only case for setting these options is testing multicasting via multiple UDP sockets. Additionally, if the ‘SO_EXCLUSIVEADDRUSE’ socket option is available (i.e. on Windows), it will be set on the socket. This will prevent anyone else from binding to our host/port for the duration of the test. -- Function: test.support.bind_unix_socket (sock, addr) Bind a unix socket, raising *note unittest.SkipTest: 903. if *note PermissionError: 5ff. is raised. -- Function: test.support.catch_threading_exception () Context manager catching *note threading.Thread: 235. exception using *note threading.excepthook(): 231. Attributes set when an exception is catched: * ‘exc_type’ * ‘exc_value’ * ‘exc_traceback’ * ‘thread’ See *note threading.excepthook(): 231. documentation. These attributes are deleted at the context manager exit. Usage: with support.catch_threading_exception() as cm: # code spawning a thread which raises an exception ... # check the thread exception, use cm attributes: # exc_type, exc_value, exc_traceback, thread ... # exc_type, exc_value, exc_traceback, thread attributes of cm no longer # exists at this point # (to avoid reference cycles) New in version 3.8. -- Function: test.support.catch_unraisable_exception () Context manager catching unraisable exception using *note sys.unraisablehook(): 22d. Storing the exception value (‘cm.unraisable.exc_value’) creates a reference cycle. The reference cycle is broken explicitly when the context manager exits. Storing the object (‘cm.unraisable.object’) can resurrect it if it is set to an object which is being finalized. Exiting the context manager clears the stored object. Usage: with support.catch_unraisable_exception() as cm: # code creating an "unraisable exception" ... # check the unraisable exception: use cm.unraisable ... # cm.unraisable attribute no longer exists at this point # (to break a reference cycle) New in version 3.8. -- Function: test.support.find_unused_port (family=socket.AF_INET, socktype=socket.SOCK_STREAM) Returns an unused port that should be suitable for binding. This is achieved by creating a temporary socket with the same family and type as the ‘sock’ parameter (default is *note AF_INET: 229d, *note SOCK_STREAM: c8a.), and binding it to the specified host address (defaults to ‘0.0.0.0’) with the port set to 0, eliciting an unused ephemeral port from the OS. The temporary socket is then closed and deleted, and the ephemeral port is returned. Either this method or *note bind_port(): 31bb. should be used for any tests where a server socket needs to be bound to a particular port for the duration of the test. Which one to use depends on whether the calling code is creating a Python socket, or if an unused port needs to be provided in a constructor or passed to an external program (i.e. the ‘-accept’ argument to openssl’s s_server mode). Always prefer *note bind_port(): 31bb. over *note find_unused_port(): 31bf. where possible. Using a hard coded port is discouraged since it can make multiple instances of the test impossible to run simultaneously, which is a problem for buildbots. -- Function: test.support.load_package_tests (pkg_dir, loader, standard_tests, pattern) Generic implementation of the *note unittest: 11b. ‘load_tests’ protocol for use in test packages. `pkg_dir' is the root directory of the package; `loader', `standard_tests', and `pattern' are the arguments expected by ‘load_tests’. In simple cases, the test package’s ‘__init__.py’ can be the following: import os from test.support import load_package_tests def load_tests(*args): return load_package_tests(os.path.dirname(__file__), *args) -- Function: test.support.fs_is_case_insensitive (directory) Return ‘True’ if the file system for `directory' is case-insensitive. -- Function: test.support.detect_api_mismatch (ref_api, other_api, *, ignore=()) Returns the set of attributes, functions or methods of `ref_api' not found on `other_api', except for a defined list of items to be ignored in this check specified in `ignore'. By default this skips private attributes beginning with ‘_’ but includes all magic methods, i.e. those starting and ending in ‘__’. New in version 3.5. -- Function: test.support.patch (test_instance, object_to_patch, attr_name, new_value) Override `object_to_patch.attr_name' with `new_value'. Also add cleanup procedure to `test_instance' to restore `object_to_patch' for `attr_name'. The `attr_name' should be a valid attribute for `object_to_patch'. -- Function: test.support.run_in_subinterp (code) Run `code' in subinterpreter. Raise *note unittest.SkipTest: 903. if *note tracemalloc: 114. is enabled. -- Function: test.support.check_free_after_iterating (test, iter, cls, args=()) Assert that `iter' is deallocated after iterating. -- Function: test.support.missing_compiler_executable (cmd_names=[]) Check for the existence of the compiler executables whose names are listed in `cmd_names' or all the compiler executables when `cmd_names' is empty and return the first missing executable or ‘None’ when none is found missing. -- Function: test.support.check__all__ (test_case, module, name_of_module=None, extra=(), blacklist=()) Assert that the ‘__all__’ variable of `module' contains all public names. The module’s public names (its API) are detected automatically based on whether they match the public name convention and were defined in `module'. The `name_of_module' argument can specify (as a string or tuple thereof) what module(s) an API could be defined in order to be detected as a public API. One case for this is when `module' imports part of its public API from other modules, possibly a C backend (like ‘csv’ and its ‘_csv’). The `extra' argument can be a set of names that wouldn’t otherwise be automatically detected as “public”, like objects without a proper ‘__module__’ attribute. If provided, it will be added to the automatically detected ones. The `blacklist' argument can be a set of names that must not be treated as part of the public API even though their names indicate otherwise. Example use: import bar import foo import unittest from test import support class MiscTestCase(unittest.TestCase): def test__all__(self): support.check__all__(self, foo) class OtherTestCase(unittest.TestCase): def test__all__(self): extra = {'BAR_CONST', 'FOO_CONST'} blacklist = {'baz'} # Undocumented name. # bar imports part of its API from _bar. support.check__all__(self, bar, ('bar', '_bar'), extra=extra, blacklist=blacklist) New in version 3.6. The *note test.support: 106. module defines the following classes: -- Class: test.support.TransientResource (exc, **kwargs) Instances are a context manager that raises *note ResourceDenied: 3147. if the specified exception type is raised. Any keyword arguments are treated as attribute/value pairs to be compared against any exception raised within the *note with: 6e9. statement. Only if all pairs match properly against attributes on the exception is *note ResourceDenied: 3147. raised. -- Class: test.support.EnvironmentVarGuard Class used to temporarily set or unset environment variables. Instances can be used as a context manager and have a complete dictionary interface for querying/modifying the underlying ‘os.environ’. After exit from the context manager all changes to environment variables done through this instance will be rolled back. Changed in version 3.1: Added dictionary interface. -- Method: EnvironmentVarGuard.set (envvar, value) Temporarily set the environment variable ‘envvar’ to the value of ‘value’. -- Method: EnvironmentVarGuard.unset (envvar) Temporarily unset the environment variable ‘envvar’. -- Class: test.support.SuppressCrashReport A context manager used to try to prevent crash dialog popups on tests that are expected to crash a subprocess. On Windows, it disables Windows Error Reporting dialogs using SetErrorMode(3). On UNIX, *note resource.setrlimit(): 31cd. is used to set *note resource.RLIMIT_CORE: 31ce.’s soft limit to 0 to prevent coredump file creation. On both platforms, the old value is restored by *note __exit__(): c96. -- Class: test.support.CleanImport (*module_names) A context manager to force import to return a new module reference. This is useful for testing module-level behaviors, such as the emission of a DeprecationWarning on import. Example usage: with CleanImport('foo'): importlib.import_module('foo') # New reference. -- Class: test.support.DirsOnSysPath (*paths) A context manager to temporarily add directories to sys.path. This makes a copy of *note sys.path: 488, appends any directories given as positional arguments, then reverts *note sys.path: 488. to the copied settings when the context ends. Note that `all' *note sys.path: 488. modifications in the body of the context manager, including replacement of the object, will be reverted at the end of the block. -- Class: test.support.SaveSignals Class to save and restore signal handlers registered by the Python signal handler. -- Class: test.support.Matcher -- Method: matches (self, d, **kwargs) Try to match a single dict with the supplied arguments. -- Method: match_value (self, k, dv, v) Try to match a single stored value (`dv') with a supplied value (`v'). -- Class: test.support.WarningsRecorder Class used to record warnings for unit tests. See documentation of *note check_warnings(): 317a. above for more details. -- Class: test.support.BasicTestRunner -- Method: run (test) Run `test' and return the result. -- Class: test.support.TestHandler (logging.handlers.BufferingHandler) Class for logging support. -- Class: test.support.FakePath (path) Simple *note path-like object: 36a. It implements the ‘__fspath__()’ method which just returns the `path' argument. If `path' is an exception, it will be raised in ‘__fspath__()’. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147 (2) https://www.python.org/dev/peps/pep-0488 (3) https://msdn.microsoft.com/en-us/library/windows/desktop/ms680621.aspx  File: python.info, Node: test support script_helper — Utilities for the Python execution tests, Prev: test support — Utilities for the Python test suite, Up: Development Tools 5.26.10 ‘test.support.script_helper’ — Utilities for the Python execution tests ------------------------------------------------------------------------------- The *note test.support.script_helper: 107. module provides support for Python’s script execution tests. -- Function: test.support.script_helper.interpreter_requires_environment () Return ‘True’ if ‘sys.executable interpreter’ requires environment variables in order to be able to run at all. This is designed to be used with ‘@unittest.skipIf()’ to annotate tests that need to use an ‘assert_python*()’ function to launch an isolated mode (‘-I’) or no environment mode (‘-E’) sub-interpreter process. A normal build & test does not run into this situation but it can happen when trying to run the standard library test suite from an interpreter that doesn’t have an obvious home with Python’s current home finding logic. Setting *note PYTHONHOME: 4d6. is one way to get most of the testsuite to run in that situation. *note PYTHONPATH: 953. or ‘PYTHONUSERSITE’ are other common environment variables that might impact whether or not the interpreter can start. -- Function: test.support.script_helper.run_python_until_end (*args, **env_vars) Set up the environment based on `env_vars' for running the interpreter in a subprocess. The values can include ‘__isolated’, ‘__cleanenv’, ‘__cwd’, and ‘TERM’. -- Function: test.support.script_helper.assert_python_ok (*args, **env_vars) Assert that running the interpreter with `args' and optional environment variables `env_vars' succeeds (‘rc == 0’) and return a ‘(return code, stdout, stderr)’ tuple. If the ‘__cleanenv’ keyword is set, `env_vars' is used as a fresh environment. Python is started in isolated mode (command line option ‘-I’), except if the ‘__isolated’ keyword is set to ‘False’. -- Function: test.support.script_helper.assert_python_failure (*args, **env_vars) Assert that running the interpreter with `args' and optional environment variables `env_vars' fails (‘rc != 0’) and return a ‘(return code, stdout, stderr)’ tuple. See *note assert_python_ok(): 31dd. for more options. -- Function: test.support.script_helper.spawn_python (*args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, **kw) Run a Python subprocess with the given arguments. `kw' is extra keyword args to pass to *note subprocess.Popen(): 2b9. Returns a *note subprocess.Popen: 2b9. object. -- Function: test.support.script_helper.kill_python (p) Run the given *note subprocess.Popen: 2b9. process until completion and return stdout. -- Function: test.support.script_helper.make_script (script_dir, script_basename, source, omit_suffix=False) Create script containing `source' in path `script_dir' and `script_basename'. If `omit_suffix' is ‘False’, append ‘.py’ to the name. Return the full script path. -- Function: test.support.script_helper.make_zip_script (zip_dir, zip_basename, script_name, name_in_zip=None) Create zip file at `zip_dir' and `zip_basename' with extension ‘zip’ which contains the files in `script_name'. `name_in_zip' is the archive name. Return a tuple containing ‘(full path, full path of archive name)’. -- Function: test.support.script_helper.make_pkg (pkg_dir, init_source='') Create a directory named `pkg_dir' containing an ‘__init__’ file with `init_source' as its contents. -- Function: test.support.script_helper.make_zip_pkg (zip_dir, zip_basename, pkg_name, script_basename, source, depth=1, compiled=False) Create a zip package directory with a path of `zip_dir' and `zip_basename' containing an empty ‘__init__’ file and a file `script_basename' containing the `source'. If `compiled' is ‘True’, both source files will be compiled and added to the zip package. Return a tuple of the full zip path and the archive name for the zip file. See also the Python development mode: the *note -X: 155. ‘dev’ option and *note PYTHONDEVMODE: 32c. environment variable.  File: python.info, Node: Debugging and Profiling, Next: Software Packaging and Distribution, Prev: Development Tools, Up: The Python Standard Library 5.27 Debugging and Profiling ============================ These libraries help you with Python development: the debugger enables you to step through code, analyze stack frames and set breakpoints etc., and the profilers run code and give you a detailed breakdown of execution times, allowing you to identify bottlenecks in your programs. Auditing events provide visibility into runtime behaviors that would otherwise require intrusive debugging or patching. * Menu: * Audit events table:: * bdb — Debugger framework:: * faulthandler — Dump the Python traceback:: * pdb — The Python Debugger:: * The Python Profilers:: * timeit — Measure execution time of small code snippets:: * trace — Trace or track Python statement execution:: * tracemalloc — Trace memory allocations::  File: python.info, Node: Audit events table, Next: bdb — Debugger framework, Up: Debugging and Profiling 5.27.1 Audit events table ------------------------- This table contains all events raised by *note sys.audit(): 31ea. or *note PySys_Audit(): 31eb. calls throughout the CPython runtime and the standard library. These calls were added in 3.8.0 or later. See *note sys.addaudithook(): 31ec. and *note PySys_AddAuditHook(): 31ed. for information on handling these events. `CPython implementation detail:' This table is generated from the CPython documentation, and may not represent events raised by other implementations. See your runtime specific documentation for actual events raised. Audit event Arguments References ------------------------------------------------------------------------------------------------------------------- array.__new__ ‘typecode’, ‘initializer’ *note [1]: 451. builtins.breakpoint ‘breakpointhook’ *note [1]: 2f9. builtins.id ‘id’ *note [1]: d86. builtins.input ‘prompt’ *note [1]: c6b. builtins.input/result ‘result’ *note [1]: c6b. code.__new__ ‘code’, ‘filename’, ‘name’, ‘argcount’, *note [1]: 198. ‘posonlyargcount’, ‘kwonlyargcount’, ‘nlocals’, ‘stacksize’, ‘flags’ compile ‘source’, ‘filename’ *note [1]: 1b4. cpython.PyInterpreterState_Clear *note [1]: 31ee. cpython.PyInterpreterState_New *note [1]: 31ef. cpython._PySys_ClearAuditHooks *note [1]: 5c9. cpython.run_command ‘command’ *note [1]: e9e. cpython.run_file ‘filename’ *note [1]: 31f0. cpython.run_interactivehook ‘hook’ *note [1]: 8e4. cpython.run_module ‘module-name’ *note [1]: 337. cpython.run_startup ‘filename’ *note [1]: 8e5. cpython.run_stdin *note [1]: 31f1. ctypes.addressof ‘obj’ *note [1]: 2004. ctypes.call_function ‘func_pointer’, ‘arguments’ *note [1]: 1ff9. ctypes.cdata ‘address’ *note [1]: 2017. ctypes.cdata/buffer ‘pointer’, ‘size’, ‘offset’ *note [1]: 2015.*note [2]: 2016. ctypes.create_string_buffer ‘init’, ‘size’ *note [1]: 1fb4. ctypes.create_unicode_buffer ‘init’, ‘size’ *note [1]: 1fb5. ctypes.dlopen ‘name’ *note [1]: 1ff6. ctypes.dlsym ‘library’, ‘name’ *note [1]: 1ff6. ctypes.dlsym/handle ‘handle’, ‘name’ *note [1]: 1ff6. ctypes.get_errno *note [1]: 1ff0. ctypes.get_last_error *note [1]: 1ff2. ctypes.seh_exception ‘code’ *note [1]: 1ff9. ctypes.set_errno ‘errno’ *note [1]: 1ff1. ctypes.set_last_error ‘error’ *note [1]: 1ff3. ctypes.string_at ‘address’, ‘size’ *note [1]: 200d. ctypes.wstring_at ‘address’, ‘size’ *note [1]: 200f. ensurepip.bootstrap ‘root’ *note [1]: 31f2. exec ‘code_object’ *note [1]: b90.*note [2]: c44. fcntl.fcntl ‘fd’, ‘cmd’, ‘arg’ *note [1]: 2393. fcntl.flock ‘fd’, ‘operation’ *note [1]: 31f3. fcntl.ioctl ‘fd’, ‘request’, ‘arg’ *note [1]: dde. fcntl.lockf ‘fd’, ‘cmd’, ‘len’, ‘start’, ‘whence’ *note [1]: d52. ftplib.connect ‘self’, ‘host’, ‘port’ *note [1]: 2a21. ftplib.sendcmd ‘self’, ‘cmd’ *note [1]: 2a25.*note [2]: 2a26. function.__new__ ‘code’ *note [1]: 1658. gc.get_objects ‘generation’ *note [1]: 1cd. gc.get_referents ‘objs’ *note [1]: 31f4. gc.get_referrers ‘objs’ *note [1]: 31f5. glob.glob ‘pathname’, ‘recursive’ *note [1]: 5c6.*note [2]: 5c7. imaplib.open ‘self’, ‘host’, ‘port’ *note [1]: 2a71. imaplib.send ‘self’, ‘data’ *note [1]: 2a74. import ‘module’, ‘filename’, ‘sys.path’, ‘sys.meta_path’, *note [1]: c1d. ‘sys.path_hooks’ mmap.__new__ ‘fileno’, ‘length’, ‘access’, ‘offset’ *note [1]: 1ec. msvcrt.get_osfhandle ‘fd’ *note [1]: 31f6. msvcrt.locking ‘fd’, ‘mode’, ‘nbytes’ *note [1]: 31f7. msvcrt.open_osfhandle ‘handle’, ‘flags’ *note [1]: 31f8. nntplib.connect ‘self’, ‘host’, ‘port’ *note [1]: a2c.*note [2]: ba5. nntplib.putline ‘self’, ‘line’ *note [1]: a2c.*note [2]: ba5. object.__delattr__ ‘obj’, ‘name’ *note [1]: 10d1. object.__getattr__ ‘obj’, ‘name’ *note [1]: 449. object.__setattr__ ‘obj’, ‘name’, ‘value’ *note [1]: e2c. open ‘file’, ‘mode’, ‘flags’ *note [1]: 4f0.*note [2]: 65a.*note [3]: 665. os.add_dll_directory ‘path’ *note [1]: 1c2. os.chdir ‘path’ *note [1]: a3f.*note [2]: 65b. os.chflags ‘path’, ‘flags’ *note [1]: a32.*note [2]: 1c22. os.chmod ‘path’, ‘mode’, ‘dir_fd’ *note [1]: a33.*note [2]: 65c.*note [3]: 1c23. os.chown ‘path’, ‘uid’, ‘gid’, ‘dir_fd’ *note [1]: a34.*note [2]: 65d.*note [3]: 1c24. os.exec ‘path’, ‘args’, ‘env’ *note [1]: 1c60. os.fork *note [1]: 961. os.forkpty *note [1]: 1c78. os.getxattr ‘path’, ‘attribute’ *note [1]: a4b. os.kill ‘pid’, ‘sig’ *note [1]: cf3. os.killpg ‘pgid’, ‘sig’ *note [1]: 1c7b. os.link ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’ *note [1]: a35. os.listdir ‘path’ *note [1]: a41. os.listxattr ‘path’ *note [1]: a4c. os.lockf ‘fd’, ‘cmd’, ‘len’ *note [1]: a5a. os.mkdir ‘path’, ‘mode’, ‘dir_fd’ *note [1]: 3bd.*note [2]: a36. os.posix_spawn ‘path’, ‘argv’, ‘env’ *note [1]: 257.*note [2]: 1c7d. os.putenv ‘key’, ‘value’ *note [1]: 1bb6. os.remove ‘path’, ‘dir_fd’ *note [1]: a37.*note [2]: 1c2b.*note [3]: a3c. os.removexattr ‘path’, ‘attribute’ *note [1]: a4d. os.rename ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’ *note [1]: a38.*note [2]: 1c2c.*note [3]: a39. os.rmdir ‘path’, ‘dir_fd’ *note [1]: a3a. os.scandir ‘path’ *note [1]: 25f. os.setxattr ‘path’, ‘attribute’, ‘value’, ‘flags’ *note [1]: a4e. os.spawn ‘mode’, ‘path’, ‘args’, ‘env’ *note [1]: 1c1a. os.startfile ‘path’, ‘operation’ *note [1]: 1c8e. os.symlink ‘src’, ‘dst’, ‘dir_fd’ *note [1]: a3b. os.system ‘command’ *note [1]: dc1. os.truncate ‘fd’, ‘length’ *note [1]: 662.*note [2]: 724. os.unsetenv ‘key’ *note [1]: d43. os.utime ‘path’, ‘times’, ‘ns’, ‘dir_fd’ *note [1]: a3d. pdb.Pdb *note [1]: 56c. pickle.find_class ‘module’, ‘name’ *note [1]: 1983. poplib.connect ‘self’, ‘host’, ‘port’ *note [1]: 2a3c.*note [2]: bc1. poplib.putline ‘self’, ‘line’ *note [1]: 2a3c.*note [2]: bc1. pty.spawn ‘argv’ *note [1]: 898. resource.prlimit ‘pid’, ‘resource’, ‘limits’ *note [1]: 89f. resource.setrlimit ‘resource’, ‘limits’ *note [1]: 31cd. setopencodehook *note [1]: 1cc1. shutil.chown ‘path’, ‘user’, ‘group’ *note [1]: a76. shutil.copyfile ‘src’, ‘dst’ *note [1]: 259.*note [2]: 25a.*note [3]: 258. shutil.copymode ‘src’, ‘dst’ *note [1]: 259.*note [2]: 1947. shutil.copystat ‘src’, ‘dst’ *note [1]: 25a.*note [2]: a77. shutil.copytree ‘src’, ‘dst’ *note [1]: 21a. shutil.make_archive ‘base_name’, ‘format’, ‘root_dir’, ‘base_dir’ *note [1]: 21b. shutil.move ‘src’, ‘dst’ *note [1]: 25b. shutil.rmtree ‘path’ *note [1]: 21c. shutil.unpack_archive ‘filename’, ‘extract_dir’, ‘format’ *note [1]: b97. signal.pthread_kill ‘thread_id’, ‘signalnum’ *note [1]: a7a. smtplib.connect ‘self’, ‘host’, ‘port’ *note [1]: 2aba. smtplib.send ‘self’, ‘data’ *note [1]: a81. socket.__new__ ‘self’, ‘family’, ‘type’, ‘protocol’ *note [1]: 674. socket.bind ‘self’, ‘address’ *note [1]: 238d. socket.connect ‘self’, ‘address’ *note [1]: 676.*note [2]: 238f. socket.getaddrinfo ‘host’, ‘port’, ‘family’, ‘type’, ‘protocol’ *note [1]: 22b1. socket.gethostbyaddr ‘ip_address’ *note [1]: 2364. socket.gethostbyname ‘hostname’ *note [1]: 2382.*note [2]: 2363. socket.gethostname *note [1]: 1bd6. socket.getnameinfo ‘sockaddr’ *note [1]: 22b2. socket.getservbyname ‘servicename’, ‘protocolname’ *note [1]: 2384. socket.getservbyport ‘port’, ‘protocolname’ *note [1]: 2385. socket.sendmsg ‘self’, ‘address’ *note [1]: 67c. socket.sendto ‘self’, ‘address’ *note [1]: 67d. socket.sethostname ‘name’ *note [1]: a87. sqlite3.connect ‘database’ *note [1]: 3da. subprocess.Popen ‘executable’, ‘args’, ‘cwd’, ‘env’ *note [1]: 2b9. sys._current_frames *note [1]: d9b. sys._getframe *note [1]: e64. sys.addaudithook *note [1]: 31ed.*note [2]: 31ec. sys.excepthook ‘hook’, ‘type’, ‘value’, ‘traceback’ *note [1]: e63. sys.set_asyncgen_hooks_finalizer *note [1]: 11b2. sys.set_asyncgen_hooks_firstiter *note [1]: 11b2. sys.setprofile *note [1]: e3d. sys.settrace *note [1]: e3e. sys.unraisablehook ‘hook’, ‘unraisable’ *note [1]: 22d. syslog.closelog *note [1]: 31f9. syslog.openlog ‘ident’, ‘logoption’, ‘facility’ *note [1]: 31fa. syslog.setlogmask ‘maskpri’ *note [1]: 31fb. syslog.syslog ‘priority’, ‘message’ *note [1]: 31fc. telnetlib.Telnet.open ‘self’, ‘host’, ‘port’ *note [1]: 2ae8. telnetlib.Telnet.write ‘self’, ‘buffer’ *note [1]: 2af8. tempfile.mkdtemp ‘fullpath’ *note [1]: bc8.*note [2]: 1927. tempfile.mkstemp ‘fullpath’ *note [1]: d49.*note [2]: 1925.*note [3]: 1926. urllib.Request ‘fullurl’, ‘data’, ‘headers’, ‘method’ *note [1]: 78c. webbrowser.open ‘url’ *note [1]: 28d1. winreg.ConnectRegistry ‘computer_name’, ‘key’ *note [1]: 31fd. winreg.CreateKey ‘key’, ‘sub_key’, ‘access’ *note [1]: 31fe.*note [2]: 31ff. winreg.DeleteKey ‘key’, ‘sub_key’, ‘access’ *note [1]: 3200.*note [2]: 3201. winreg.DeleteValue ‘key’, ‘value’ *note [1]: 3202. winreg.DisableReflectionKey ‘key’ *note [1]: 3203. winreg.EnableReflectionKey ‘key’ *note [1]: 3204. winreg.EnumKey ‘key’, ‘index’ *note [1]: 3205. winreg.EnumValue ‘key’, ‘index’ *note [1]: 3206. winreg.ExpandEnvironmentStrings ‘str’ *note [1]: 3207. winreg.LoadKey ‘key’, ‘sub_key’, ‘file_name’ *note [1]: 3208. winreg.OpenKey ‘key’, ‘sub_key’, ‘access’ *note [1]: 3209. winreg.OpenKey/result ‘key’ *note [1]: 31fe.*note [2]: 31ff.*note [3]: 3209. winreg.PyHKEY.Detach ‘key’ *note [1]: 320a. winreg.QueryInfoKey ‘key’ *note [1]: 320b. winreg.QueryReflectionKey ‘key’ *note [1]: 320c. winreg.QueryValue ‘key’, ‘sub_key’, ‘value_name’ *note [1]: 320d.*note [2]: 320e. winreg.SaveKey ‘key’, ‘file_name’ *note [1]: 320f. winreg.SetValue ‘key’, ‘sub_key’, ‘type’, ‘value’ *note [1]: 3210.*note [2]: 3211. The following events are raised internally and do not correspond to any public API of CPython: Audit event Arguments ------------------------------------------------------------------------------- _winapi.CreateFile ‘file_name’, ‘desired_access’, ‘share_mode’, ‘creation_disposition’, ‘flags_and_attributes’ _winapi.CreateJunction ‘src_path’, ‘dst_path’ _winapi.CreateNamedPipe ‘name’, ‘open_mode’, ‘pipe_mode’ _winapi.CreatePipe _winapi.CreateProcess ‘application_name’, ‘command_line’, ‘current_directory’ _winapi.OpenProcess ‘process_id’, ‘desired_access’ _winapi.TerminateProcess ‘handle’, ‘exit_code’ ctypes.PyObj_FromPtr ‘obj’  File: python.info, Node: bdb — Debugger framework, Next: faulthandler — Dump the Python traceback, Prev: Audit events table, Up: Debugging and Profiling 5.27.2 ‘bdb’ — Debugger framework --------------------------------- `Source code:' Lib/bdb.py(1) __________________________________________________________________ The *note bdb: f. module handles basic debugger functions, like setting breakpoints or managing execution via the debugger. The following exception is defined: -- Exception: bdb.BdbQuit Exception raised by the *note Bdb: c98. class for quitting the debugger. The *note bdb: f. module also defines two classes: -- Class: bdb.Breakpoint (self, file, line, temporary=0, cond=None, funcname=None) This class implements temporary breakpoints, ignore counts, disabling and (re-)enabling, and conditionals. Breakpoints are indexed by number through a list called ‘bpbynumber’ and by ‘(file, line)’ pairs through ‘bplist’. The former points to a single instance of class *note Breakpoint: 3215. The latter points to a list of such instances since there may be more than one breakpoint per line. When creating a breakpoint, its associated filename should be in canonical form. If a `funcname' is defined, a breakpoint hit will be counted when the first line of that function is executed. A conditional breakpoint always counts a hit. *note Breakpoint: 3215. instances have the following methods: -- Method: deleteMe () Delete the breakpoint from the list associated to a file/line. If it is the last breakpoint in that position, it also deletes the entry for the file/line. -- Method: enable () Mark the breakpoint as enabled. -- Method: disable () Mark the breakpoint as disabled. -- Method: bpformat () Return a string with all the information about the breakpoint, nicely formatted: * The breakpoint number. * If it is temporary or not. * Its file,line position. * The condition that causes a break. * If it must be ignored the next N times. * The breakpoint hit count. New in version 3.2. -- Method: bpprint (out=None) Print the output of *note bpformat(): 3219. to the file `out', or if it is ‘None’, to standard output. -- Class: bdb.Bdb (skip=None) The *note Bdb: c98. class acts as a generic Python debugger base class. This class takes care of the details of the trace facility; a derived class should implement user interaction. The standard debugger class (*note pdb.Pdb: 56c.) is an example. The `skip' argument, if given, must be an iterable of glob-style module name patterns. The debugger will not step into frames that originate in a module that matches one of these patterns. Whether a frame is considered to originate in a certain module is determined by the ‘__name__’ in the frame globals. New in version 3.1: The `skip' argument. The following methods of *note Bdb: c98. normally don’t need to be overridden. -- Method: canonic (filename) Auxiliary method for getting a filename in a canonical form, that is, as a case-normalized (on case-insensitive filesystems) absolute path, stripped of surrounding angle brackets. -- Method: reset () Set the ‘botframe’, ‘stopframe’, ‘returnframe’ and ‘quitting’ attributes with values ready to start debugging. -- Method: trace_dispatch (frame, event, arg) This function is installed as the trace function of debugged frames. Its return value is the new trace function (in most cases, that is, itself). The default implementation decides how to dispatch a frame, depending on the type of event (passed as a string) that is about to be executed. `event' can be one of the following: * ‘"line"’: A new line of code is going to be executed. * ‘"call"’: A function is about to be called, or another code block entered. * ‘"return"’: A function or other code block is about to return. * ‘"exception"’: An exception has occurred. * ‘"c_call"’: A C function is about to be called. * ‘"c_return"’: A C function has returned. * ‘"c_exception"’: A C function has raised an exception. For the Python events, specialized functions (see below) are called. For the C events, no action is taken. The `arg' parameter depends on the previous event. See the documentation for *note sys.settrace(): e3e. for more information on the trace function. For more information on code and frame objects, refer to *note The standard type hierarchy: 10c0. -- Method: dispatch_line (frame) If the debugger should stop on the current line, invoke the *note user_line(): 321f. method (which should be overridden in subclasses). Raise a *note BdbQuit: 3214. exception if the ‘Bdb.quitting’ flag is set (which can be set from *note user_line(): 321f.). Return a reference to the *note trace_dispatch(): 321d. method for further tracing in that scope. -- Method: dispatch_call (frame, arg) If the debugger should stop on this function call, invoke the *note user_call(): 3221. method (which should be overridden in subclasses). Raise a *note BdbQuit: 3214. exception if the ‘Bdb.quitting’ flag is set (which can be set from *note user_call(): 3221.). Return a reference to the *note trace_dispatch(): 321d. method for further tracing in that scope. -- Method: dispatch_return (frame, arg) If the debugger should stop on this function return, invoke the *note user_return(): 3223. method (which should be overridden in subclasses). Raise a *note BdbQuit: 3214. exception if the ‘Bdb.quitting’ flag is set (which can be set from *note user_return(): 3223.). Return a reference to the *note trace_dispatch(): 321d. method for further tracing in that scope. -- Method: dispatch_exception (frame, arg) If the debugger should stop at this exception, invokes the *note user_exception(): 3225. method (which should be overridden in subclasses). Raise a *note BdbQuit: 3214. exception if the ‘Bdb.quitting’ flag is set (which can be set from *note user_exception(): 3225.). Return a reference to the *note trace_dispatch(): 321d. method for further tracing in that scope. Normally derived classes don’t override the following methods, but they may if they want to redefine the definition of stopping and breakpoints. -- Method: stop_here (frame) This method checks if the `frame' is somewhere below ‘botframe’ in the call stack. ‘botframe’ is the frame in which debugging started. -- Method: break_here (frame) This method checks if there is a breakpoint in the filename and line belonging to `frame' or, at least, in the current function. If the breakpoint is a temporary one, this method deletes it. -- Method: break_anywhere (frame) This method checks if there is a breakpoint in the filename of the current frame. Derived classes should override these methods to gain control over debugger operation. -- Method: user_call (frame, argument_list) This method is called from *note dispatch_call(): 3220. when there is the possibility that a break might be necessary anywhere inside the called function. -- Method: user_line (frame) This method is called from *note dispatch_line(): 321e. when either *note stop_here(): 3226. or *note break_here(): 3227. yields ‘True’. -- Method: user_return (frame, return_value) This method is called from *note dispatch_return(): 3222. when *note stop_here(): 3226. yields ‘True’. -- Method: user_exception (frame, exc_info) This method is called from *note dispatch_exception(): 3224. when *note stop_here(): 3226. yields ‘True’. -- Method: do_clear (arg) Handle how a breakpoint must be removed when it is a temporary one. This method must be implemented by derived classes. Derived classes and clients can call the following methods to affect the stepping state. -- Method: set_step () Stop after one line of code. -- Method: set_next (frame) Stop on the next line in or below the given frame. -- Method: set_return (frame) Stop when returning from the given frame. -- Method: set_until (frame) Stop when the line with the line no greater than the current one is reached or when returning from current frame. -- Method: set_trace ([frame]) Start debugging from `frame'. If `frame' is not specified, debugging starts from caller’s frame. -- Method: set_continue () Stop only at breakpoints or when finished. If there are no breakpoints, set the system trace function to ‘None’. -- Method: set_quit () Set the ‘quitting’ attribute to ‘True’. This raises *note BdbQuit: 3214. in the next call to one of the ‘dispatch_*()’ methods. Derived classes and clients can call the following methods to manipulate breakpoints. These methods return a string containing an error message if something went wrong, or ‘None’ if all is well. -- Method: set_break (filename, lineno, temporary=0, cond, funcname) Set a new breakpoint. If the `lineno' line doesn’t exist for the `filename' passed as argument, return an error message. The `filename' should be in canonical form, as described in the *note canonic(): 321b. method. -- Method: clear_break (filename, lineno) Delete the breakpoints in `filename' and `lineno'. If none were set, an error message is returned. -- Method: clear_bpbynumber (arg) Delete the breakpoint which has the index `arg' in the ‘Breakpoint.bpbynumber’. If `arg' is not numeric or out of range, return an error message. -- Method: clear_all_file_breaks (filename) Delete all breakpoints in `filename'. If none were set, an error message is returned. -- Method: clear_all_breaks () Delete all existing breakpoints. -- Method: get_bpbynumber (arg) Return a breakpoint specified by the given number. If `arg' is a string, it will be converted to a number. If `arg' is a non-numeric string, if the given breakpoint never existed or has been deleted, a *note ValueError: 1fb. is raised. New in version 3.2. -- Method: get_break (filename, lineno) Check if there is a breakpoint for `lineno' of `filename'. -- Method: get_breaks (filename, lineno) Return all breakpoints for `lineno' in `filename', or an empty list if none are set. -- Method: get_file_breaks (filename) Return all breakpoints in `filename', or an empty list if none are set. -- Method: get_all_breaks () Return all breakpoints that are set. Derived classes and clients can call the following methods to get a data structure representing a stack trace. -- Method: get_stack (f, t) Get a list of records for a frame and all higher (calling) and lower frames, and the size of the higher part. -- Method: format_stack_entry (frame_lineno, lprefix=': ') Return a string with information about a stack entry, identified by a ‘(frame, lineno)’ tuple: * The canonical form of the filename which contains the frame. * The function name, or ‘"<lambda>"’. * The input arguments. * The return value. * The line of code (if it exists). The following two methods can be called by clients to use a debugger to debug a *note statement: 1847, given as a string. -- Method: run (cmd, globals=None, locals=None) Debug a statement executed via the *note exec(): c44. function. `globals' defaults to ‘__main__.__dict__’, `locals' defaults to `globals'. -- Method: runeval (expr, globals=None, locals=None) Debug an expression executed via the *note eval(): b90. function. `globals' and `locals' have the same meaning as in *note run(): 323d. -- Method: runctx (cmd, globals, locals) For backwards compatibility. Calls the *note run(): 323d. method. -- Method: runcall (func, *args, **kwds) Debug a single function call, and return its result. Finally, the module defines the following functions: -- Function: bdb.checkfuncname (b, frame) Check whether we should break here, depending on the way the breakpoint `b' was set. If it was set via line number, it checks if ‘b.line’ is the same as the one in the frame also passed as argument. If the breakpoint was set via function name, we have to check we are in the right frame (the right function) and if we are in its first executable line. -- Function: bdb.effective (file, line, frame) Determine if there is an effective (active) breakpoint at this line of code. Return a tuple of the breakpoint and a boolean that indicates if it is ok to delete a temporary breakpoint. Return ‘(None, None)’ if there is no matching breakpoint. -- Function: bdb.set_trace () Start debugging with a *note Bdb: c98. instance from caller’s frame. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/bdb.py  File: python.info, Node: faulthandler — Dump the Python traceback, Next: pdb — The Python Debugger, Prev: bdb — Debugger framework, Up: Debugging and Profiling 5.27.3 ‘faulthandler’ — Dump the Python traceback ------------------------------------------------- New in version 3.3. __________________________________________________________________ This module contains functions to dump Python tracebacks explicitly, on a fault, after a timeout, or on a user signal. Call *note faulthandler.enable(): 548. to install fault handlers for the ‘SIGSEGV’, ‘SIGFPE’, ‘SIGABRT’, ‘SIGBUS’, and ‘SIGILL’ signals. You can also enable them at startup by setting the *note PYTHONFAULTHANDLER: 9c8. environment variable or by using the *note -X: 155. ‘faulthandler’ command line option. The fault handler is compatible with system fault handlers like Apport or the Windows fault handler. The module uses an alternative stack for signal handlers if the ‘sigaltstack()’ function is available. This allows it to dump the traceback even on a stack overflow. The fault handler is called on catastrophic cases and therefore can only use signal-safe functions (e.g. it cannot allocate memory on the heap). Because of this limitation traceback dumping is minimal compared to normal Python tracebacks: * Only ASCII is supported. The ‘backslashreplace’ error handler is used on encoding. * Each string is limited to 500 characters. * Only the filename, the function name and the line number are displayed. (no source code) * It is limited to 100 frames and 100 threads. * The order is reversed: the most recent call is shown first. By default, the Python traceback is written to *note sys.stderr: 30f. To see tracebacks, applications must be run in the terminal. A log file can alternatively be passed to *note faulthandler.enable(): 548. The module is implemented in C, so tracebacks can be dumped on a crash or when Python is deadlocked. * Menu: * Dumping the traceback:: * Fault handler state:: * Dumping the tracebacks after a timeout:: * Dumping the traceback on a user signal:: * Issue with file descriptors:: * Example: Example<15>.  File: python.info, Node: Dumping the traceback, Next: Fault handler state, Up: faulthandler — Dump the Python traceback 5.27.3.1 Dumping the traceback .............................. -- Function: faulthandler.dump_traceback (file=sys.stderr, all_threads=True) Dump the tracebacks of all threads into `file'. If `all_threads' is ‘False’, dump only the current thread. Changed in version 3.5: Added support for passing file descriptor to this function.  File: python.info, Node: Fault handler state, Next: Dumping the tracebacks after a timeout, Prev: Dumping the traceback, Up: faulthandler — Dump the Python traceback 5.27.3.2 Fault handler state ............................ -- Function: faulthandler.enable (file=sys.stderr, all_threads=True) Enable the fault handler: install handlers for the ‘SIGSEGV’, ‘SIGFPE’, ‘SIGABRT’, ‘SIGBUS’ and ‘SIGILL’ signals to dump the Python traceback. If `all_threads' is ‘True’, produce tracebacks for every running thread. Otherwise, dump only the current thread. The `file' must be kept open until the fault handler is disabled: see *note issue with file descriptors: 3247. Changed in version 3.5: Added support for passing file descriptor to this function. Changed in version 3.6: On Windows, a handler for Windows exception is also installed. -- Function: faulthandler.disable () Disable the fault handler: uninstall the signal handlers installed by *note enable(): 548. -- Function: faulthandler.is_enabled () Check if the fault handler is enabled.  File: python.info, Node: Dumping the tracebacks after a timeout, Next: Dumping the traceback on a user signal, Prev: Fault handler state, Up: faulthandler — Dump the Python traceback 5.27.3.3 Dumping the tracebacks after a timeout ............................................... -- Function: faulthandler.dump_traceback_later (timeout, repeat=False, file=sys.stderr, exit=False) Dump the tracebacks of all threads, after a timeout of `timeout' seconds, or every `timeout' seconds if `repeat' is ‘True’. If `exit' is ‘True’, call ‘_exit()’ with status=1 after dumping the tracebacks. (Note ‘_exit()’ exits the process immediately, which means it doesn’t do any cleanup like flushing file buffers.) If the function is called twice, the new call replaces previous parameters and resets the timeout. The timer has a sub-second resolution. The `file' must be kept open until the traceback is dumped or *note cancel_dump_traceback_later(): 324b. is called: see *note issue with file descriptors: 3247. This function is implemented using a watchdog thread. Changed in version 3.7: This function is now always available. Changed in version 3.5: Added support for passing file descriptor to this function. -- Function: faulthandler.cancel_dump_traceback_later () Cancel the last call to *note dump_traceback_later(): 6d9.  File: python.info, Node: Dumping the traceback on a user signal, Next: Issue with file descriptors, Prev: Dumping the tracebacks after a timeout, Up: faulthandler — Dump the Python traceback 5.27.3.4 Dumping the traceback on a user signal ............................................... -- Function: faulthandler.register (signum, file=sys.stderr, all_threads=True, chain=False) Register a user signal: install a handler for the `signum' signal to dump the traceback of all threads, or of the current thread if `all_threads' is ‘False’, into `file'. Call the previous handler if chain is ‘True’. The `file' must be kept open until the signal is unregistered by *note unregister(): 324d.: see *note issue with file descriptors: 3247. Not available on Windows. Changed in version 3.5: Added support for passing file descriptor to this function. -- Function: faulthandler.unregister (signum) Unregister a user signal: uninstall the handler of the `signum' signal installed by *note register(): 6d7. Return ‘True’ if the signal was registered, ‘False’ otherwise. Not available on Windows.  File: python.info, Node: Issue with file descriptors, Next: Example<15>, Prev: Dumping the traceback on a user signal, Up: faulthandler — Dump the Python traceback 5.27.3.5 Issue with file descriptors .................................... *note enable(): 548, *note dump_traceback_later(): 6d9. and *note register(): 6d7. keep the file descriptor of their `file' argument. If the file is closed and its file descriptor is reused by a new file, or if *note os.dup2(): 3be. is used to replace the file descriptor, the traceback will be written into a different file. Call these functions again each time that the file is replaced.  File: python.info, Node: Example<15>, Prev: Issue with file descriptors, Up: faulthandler — Dump the Python traceback 5.27.3.6 Example ................ Example of a segmentation fault on Linux with and without enabling the fault handler: $ python3 -c "import ctypes; ctypes.string_at(0)" Segmentation fault $ python3 -q -X faulthandler >>> import ctypes >>> ctypes.string_at(0) Fatal Python error: Segmentation fault Current thread 0x00007fb899f39700 (most recent call first): File "/home/python/cpython/Lib/ctypes/__init__.py", line 486 in string_at File "<stdin>", line 1 in <module> Segmentation fault  File: python.info, Node: pdb — The Python Debugger, Next: The Python Profilers, Prev: faulthandler — Dump the Python traceback, Up: Debugging and Profiling 5.27.4 ‘pdb’ — The Python Debugger ---------------------------------- `Source code:' Lib/pdb.py(1) __________________________________________________________________ The module *note pdb: c9. defines an interactive source code debugger for Python programs. It supports setting (conditional) breakpoints and single stepping at the source line level, inspection of stack frames, source code listing, and evaluation of arbitrary Python code in the context of any stack frame. It also supports post-mortem debugging and can be called under program control. The debugger is extensible – it is actually defined as the class *note Pdb: 56c. This is currently undocumented but easily understood by reading the source. The extension interface uses the modules *note bdb: f. and *note cmd: 1a. The debugger’s prompt is ‘(Pdb)’. Typical usage to run a program under control of the debugger is: >>> import pdb >>> import mymodule >>> pdb.run('mymodule.test()') > <string>(0)?() (Pdb) continue > <string>(1)?() (Pdb) continue NameError: 'spam' > <string>(1)?() (Pdb) Changed in version 3.3: Tab-completion via the *note readline: de. module is available for commands and command arguments, e.g. the current global and local names are offered as arguments of the ‘p’ command. ‘pdb.py’ can also be invoked as a script to debug other scripts. For example: python3 -m pdb myscript.py When invoked as a script, pdb will automatically enter post-mortem debugging if the program being debugged exits abnormally. After post-mortem debugging (or after normal exit of the program), pdb will restart the program. Automatic restarting preserves pdb’s state (such as breakpoints) and in most cases is more useful than quitting the debugger upon program’s exit. New in version 3.2: ‘pdb.py’ now accepts a ‘-c’ option that executes commands as if given in a ‘.pdbrc’ file, see *note Debugger Commands: 3253. New in version 3.7: ‘pdb.py’ now accepts a ‘-m’ option that execute modules similar to the way ‘python3 -m’ does. As with a script, the debugger will pause execution just before the first line of the module. The typical usage to break into the debugger from a running program is to insert import pdb; pdb.set_trace() at the location you want to break into the debugger. You can then step through the code following this statement, and continue running without the debugger using the *note continue: 3254. command. New in version 3.7: The built-in *note breakpoint(): 2f9, when called with defaults, can be used instead of ‘import pdb; pdb.set_trace()’. The typical usage to inspect a crashed program is: >>> import pdb >>> import mymodule >>> mymodule.test() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "./mymodule.py", line 4, in test test2() File "./mymodule.py", line 3, in test2 print(spam) NameError: spam >>> pdb.pm() > ./mymodule.py(3)test2() -> print(spam) (Pdb) The module defines the following functions; each enters the debugger in a slightly different way: -- Function: pdb.run (statement, globals=None, locals=None) Execute the `statement' (given as a string or a code object) under debugger control. The debugger prompt appears before any code is executed; you can set breakpoints and type *note continue: 3254, or you can step through the statement using *note step: 3255. or *note next: 3256. (all these commands are explained below). The optional `globals' and `locals' arguments specify the environment in which the code is executed; by default the dictionary of the module *note __main__: 1. is used. (See the explanation of the built-in *note exec(): c44. or *note eval(): b90. functions.) -- Function: pdb.runeval (expression, globals=None, locals=None) Evaluate the `expression' (given as a string or a code object) under debugger control. When *note runeval(): 3257. returns, it returns the value of the expression. Otherwise this function is similar to *note run(): 3022. -- Function: pdb.runcall (function, *args, **kwds) Call the `function' (a function or method object, not a string) with the given arguments. When *note runcall(): 3258. returns, it returns whatever the function call returned. The debugger prompt appears as soon as the function is entered. -- Function: pdb.set_trace (*, header=None) Enter the debugger at the calling stack frame. This is useful to hard-code a breakpoint at a given point in a program, even if the code is not otherwise being debugged (e.g. when an assertion fails). If given, `header' is printed to the console just before debugging begins. Changed in version 3.7: The keyword-only argument `header'. -- Function: pdb.post_mortem (traceback=None) Enter post-mortem debugging of the given `traceback' object. If no `traceback' is given, it uses the one of the exception that is currently being handled (an exception must be being handled if the default is to be used). -- Function: pdb.pm () Enter post-mortem debugging of the traceback found in *note sys.last_traceback: 325a. The ‘run*’ functions and *note set_trace(): 3c2. are aliases for instantiating the *note Pdb: 56c. class and calling the method of the same name. If you want to access further features, you have to do this yourself: -- Class: pdb.Pdb (completekey='tab', stdin=None, stdout=None, skip=None, nosigint=False, readrc=True) *note Pdb: 56c. is the debugger class. The `completekey', `stdin' and `stdout' arguments are passed to the underlying *note cmd.Cmd: 2e48. class; see the description there. The `skip' argument, if given, must be an iterable of glob-style module name patterns. The debugger will not step into frames that originate in a module that matches one of these patterns. (2) By default, Pdb sets a handler for the SIGINT signal (which is sent when the user presses ‘Ctrl-C’ on the console) when you give a ‘continue’ command. This allows you to break into the debugger again by pressing ‘Ctrl-C’. If you want Pdb not to touch the SIGINT handler, set `nosigint' to true. The `readrc' argument defaults to true and controls whether Pdb will load .pdbrc files from the filesystem. Example call to enable tracing with `skip': import pdb; pdb.Pdb(skip=['django.*']).set_trace() Raises an *note auditing event: fd1. ‘pdb.Pdb’ with no arguments. New in version 3.1: The `skip' argument. New in version 3.2: The `nosigint' argument. Previously, a SIGINT handler was never set by Pdb. Changed in version 3.6: The `readrc' argument. -- Method: run (statement, globals=None, locals=None) -- Method: runeval (expression, globals=None, locals=None) -- Method: runcall (function, *args, **kwds) -- Method: set_trace () See the documentation for the functions explained above. * Menu: * Debugger Commands:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pdb.py (2) (1) Whether a frame is considered to originate in a certain module is determined by the ‘__name__’ in the frame globals.  File: python.info, Node: Debugger Commands, Up: pdb — The Python Debugger 5.27.4.1 Debugger Commands .......................... The commands recognized by the debugger are listed below. Most commands can be abbreviated to one or two letters as indicated; e.g. ‘h(elp)’ means that either ‘h’ or ‘help’ can be used to enter the help command (but not ‘he’ or ‘hel’, nor ‘H’ or ‘Help’ or ‘HELP’). Arguments to commands must be separated by whitespace (spaces or tabs). Optional arguments are enclosed in square brackets (‘[]’) in the command syntax; the square brackets must not be typed. Alternatives in the command syntax are separated by a vertical bar (‘|’). Entering a blank line repeats the last command entered. Exception: if the last command was a *note list: 3260. command, the next 11 lines are listed. Commands that the debugger doesn’t recognize are assumed to be Python statements and are executed in the context of the program being debugged. Python statements can also be prefixed with an exclamation point (‘!’). This is a powerful way to inspect the program being debugged; it is even possible to change a variable or call a function. When an exception occurs in such a statement, the exception name is printed but the debugger’s state is not changed. The debugger supports *note aliases: 3261. Aliases can have parameters which allows one a certain level of adaptability to the context under examination. Multiple commands may be entered on a single line, separated by ‘;;’. (A single ‘;’ is not used as it is the separator for multiple commands in a line that is passed to the Python parser.) No intelligence is applied to separating the commands; the input is split at the first ‘;;’ pair, even if it is in the middle of a quoted string. If a file ‘.pdbrc’ exists in the user’s home directory or in the current directory, it is read in and executed as if it had been typed at the debugger prompt. This is particularly useful for aliases. If both files exist, the one in the home directory is read first and aliases defined there can be overridden by the local file. Changed in version 3.2: ‘.pdbrc’ can now contain commands that continue debugging, such as *note continue: 3254. or *note next: 3256. Previously, these commands had no effect. -- Pdbcommand: h(elp) [command] Without argument, print the list of available commands. With a `command' as argument, print help about that command. ‘help pdb’ displays the full documentation (the docstring of the *note pdb: c9. module). Since the `command' argument must be an identifier, ‘help exec’ must be entered to get help on the ‘!’ command. -- Pdbcommand: w(here) Print a stack trace, with the most recent frame at the bottom. An arrow indicates the current frame, which determines the context of most commands. -- Pdbcommand: d(own) [count] Move the current frame `count' (default one) levels down in the stack trace (to a newer frame). -- Pdbcommand: u(p) [count] Move the current frame `count' (default one) levels up in the stack trace (to an older frame). -- Pdbcommand: b(reak) [([filename:]lineno | function) [, condition]] With a `lineno' argument, set a break there in the current file. With a `function' argument, set a break at the first executable statement within that function. The line number may be prefixed with a filename and a colon, to specify a breakpoint in another file (probably one that hasn’t been loaded yet). The file is searched on *note sys.path: 488. Note that each breakpoint is assigned a number to which all the other breakpoint commands refer. If a second argument is present, it is an expression which must evaluate to true before the breakpoint is honored. Without argument, list all breaks, including for each breakpoint, the number of times that breakpoint has been hit, the current ignore count, and the associated condition if any. -- Pdbcommand: tbreak [([filename:]lineno | function) [, condition]] Temporary breakpoint, which is removed automatically when it is first hit. The arguments are the same as for *note break: 3266. -- Pdbcommand: cl(ear) [filename:lineno | bpnumber [bpnumber ...]] With a `filename:lineno' argument, clear all the breakpoints at this line. With a space separated list of breakpoint numbers, clear those breakpoints. Without argument, clear all breaks (but first ask confirmation). -- Pdbcommand: disable [bpnumber [bpnumber ...]] Disable the breakpoints given as a space separated list of breakpoint numbers. Disabling a breakpoint means it cannot cause the program to stop execution, but unlike clearing a breakpoint, it remains in the list of breakpoints and can be (re-)enabled. -- Pdbcommand: enable [bpnumber [bpnumber ...]] Enable the breakpoints specified. -- Pdbcommand: ignore bpnumber [count] Set the ignore count for the given breakpoint number. If count is omitted, the ignore count is set to 0. A breakpoint becomes active when the ignore count is zero. When non-zero, the count is decremented each time the breakpoint is reached and the breakpoint is not disabled and any associated condition evaluates to true. -- Pdbcommand: condition bpnumber [condition] Set a new `condition' for the breakpoint, an expression which must evaluate to true before the breakpoint is honored. If `condition' is absent, any existing condition is removed; i.e., the breakpoint is made unconditional. -- Pdbcommand: commands [bpnumber] Specify a list of commands for breakpoint number `bpnumber'. The commands themselves appear on the following lines. Type a line containing just ‘end’ to terminate the commands. An example: (Pdb) commands 1 (com) p some_variable (com) end (Pdb) To remove all commands from a breakpoint, type ‘commands’ and follow it immediately with ‘end’; that is, give no commands. With no `bpnumber' argument, ‘commands’ refers to the last breakpoint set. You can use breakpoint commands to start your program up again. Simply use the *note continue: 3254. command, or *note step: 3255, or any other command that resumes execution. Specifying any command resuming execution (currently *note continue: 3254, *note step: 3255, *note next: 3256, *note return: 326e, *note jump: 326f, *note quit: 3270. and their abbreviations) terminates the command list (as if that command was immediately followed by end). This is because any time you resume execution (even with a simple next or step), you may encounter another breakpoint—which could have its own command list, leading to ambiguities about which list to execute. If you use the ‘silent’ command in the command list, the usual message about stopping at a breakpoint is not printed. This may be desirable for breakpoints that are to print a specific message and then continue. If none of the other commands print anything, you see no sign that the breakpoint was reached. -- Pdbcommand: s(tep) Execute the current line, stop at the first possible occasion (either in a function that is called or on the next line in the current function). -- Pdbcommand: n(ext) Continue execution until the next line in the current function is reached or it returns. (The difference between *note next: 3256. and *note step: 3255. is that *note step: 3255. stops inside a called function, while *note next: 3256. executes called functions at (nearly) full speed, only stopping at the next line in the current function.) -- Pdbcommand: unt(il) [lineno] Without argument, continue execution until the line with a number greater than the current one is reached. With a line number, continue execution until a line with a number greater or equal to that is reached. In both cases, also stop when the current frame returns. Changed in version 3.2: Allow giving an explicit line number. -- Pdbcommand: r(eturn) Continue execution until the current function returns. -- Pdbcommand: c(ont(inue)) Continue execution, only stop when a breakpoint is encountered. -- Pdbcommand: j(ump) lineno Set the next line that will be executed. Only available in the bottom-most frame. This lets you jump back and execute code again, or jump forward to skip code that you don’t want to run. It should be noted that not all jumps are allowed – for instance it is not possible to jump into the middle of a *note for: c30. loop or out of a *note finally: 182. clause. -- Pdbcommand: l(ist) [first[, last]] List source code for the current file. Without arguments, list 11 lines around the current line or continue the previous listing. With ‘.’ as argument, list 11 lines around the current line. With one argument, list 11 lines around at that line. With two arguments, list the given range; if the second argument is less than the first, it is interpreted as a count. The current line in the current frame is indicated by ‘->’. If an exception is being debugged, the line where the exception was originally raised or propagated is indicated by ‘>>’, if it differs from the current line. New in version 3.2: The ‘>>’ marker. -- Pdbcommand: ll | longlist List all source code for the current function or frame. Interesting lines are marked as for *note list: 3260. New in version 3.2. -- Pdbcommand: a(rgs) Print the argument list of the current function. -- Pdbcommand: p expression Evaluate the `expression' in the current context and print its value. Note: ‘print()’ can also be used, but is not a debugger command — this executes the Python *note print(): 886. function. -- Pdbcommand: pp expression Like the *note p: 887. command, except the value of the expression is pretty-printed using the *note pprint: d2. module. -- Pdbcommand: whatis expression Print the type of the `expression'. -- Pdbcommand: source expression Try to get source code for the given object and display it. New in version 3.2. -- Pdbcommand: display [expression] Display the value of the expression if it changed, each time execution stops in the current frame. Without expression, list all display expressions for the current frame. New in version 3.2. -- Pdbcommand: undisplay [expression] Do not display the expression any more in the current frame. Without expression, clear all display expressions for the current frame. New in version 3.2. -- Pdbcommand: interact Start an interactive interpreter (using the *note code: 1b. module) whose global namespace contains all the (global and local) names found in the current scope. New in version 3.2. -- Pdbcommand: alias [name [command]] Create an alias called `name' that executes `command'. The command must `not' be enclosed in quotes. Replaceable parameters can be indicated by ‘%1’, ‘%2’, and so on, while ‘%*’ is replaced by all the parameters. If no command is given, the current alias for `name' is shown. If no arguments are given, all aliases are listed. Aliases may be nested and can contain anything that can be legally typed at the pdb prompt. Note that internal pdb commands `can' be overridden by aliases. Such a command is then hidden until the alias is removed. Aliasing is recursively applied to the first word of the command line; all other words in the line are left alone. As an example, here are two useful aliases (especially when placed in the ‘.pdbrc’ file): # Print instance variables (usage "pi classInst") alias pi for k in %1.__dict__.keys(): print("%1.",k,"=",%1.__dict__[k]) # Print instance variables in self alias ps pi self -- Pdbcommand: unalias name Delete the specified alias. -- Pdbcommand: ! statement Execute the (one-line) `statement' in the context of the current stack frame. The exclamation point can be omitted unless the first word of the statement resembles a debugger command. To set a global variable, you can prefix the assignment command with a *note global: ed8. statement on the same line, e.g.: (Pdb) global list_options; list_options = ['-l'] (Pdb) -- Pdbcommand: run [args ...] -- Pdbcommand: restart [args ...] Restart the debugged Python program. If an argument is supplied, it is split with *note shlex: e8. and the result is used as the new *note sys.argv: bfb. History, breakpoints, actions and debugger options are preserved. *note restart: 327e. is an alias for *note run: 327d. -- Pdbcommand: q(uit) Quit from the debugger. The program being executed is aborted. -- Pdbcommand: debug code Enter a recursive debugger that steps through the code argument (which is an arbitrary expression or statement to be executed in the current environment). -- Pdbcommand: retval Print the return value for the last return of a function.  File: python.info, Node: The Python Profilers, Next: timeit — Measure execution time of small code snippets, Prev: pdb — The Python Debugger, Up: Debugging and Profiling 5.27.5 The Python Profilers --------------------------- `Source code:' Lib/profile.py(1) and Lib/pstats.py(2) __________________________________________________________________ * Menu: * Introduction to the profilers:: * Instant User’s Manual:: * profile and cProfile Module Reference:: * The Stats Class:: * What Is Deterministic Profiling?:: * Limitations:: * Calibration:: * Using a custom timer:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/profile.py (2) https://github.com/python/cpython/tree/3.8/Lib/pstats.py  File: python.info, Node: Introduction to the profilers, Next: Instant User’s Manual, Up: The Python Profilers 5.27.5.1 Introduction to the profilers ...................................... *note cProfile: 28. and *note profile: d3. provide `deterministic profiling' of Python programs. A `profile' is a set of statistics that describes how often and for how long various parts of the program executed. These statistics can be formatted into reports via the *note pstats: d4. module. The Python standard library provides two different implementations of the same profiling interface: 1. *note cProfile: 28. is recommended for most users; it’s a C extension with reasonable overhead that makes it suitable for profiling long-running programs. Based on ‘lsprof’, contributed by Brett Rosen and Ted Czotter. 2. *note profile: d3, a pure Python module whose interface is imitated by *note cProfile: 28, but which adds significant overhead to profiled programs. If you’re trying to extend the profiler in some way, the task might be easier with this module. Originally designed and written by Jim Roskind. Note: The profiler modules are designed to provide an execution profile for a given program, not for benchmarking purposes (for that, there is *note timeit: 10b. for reasonably accurate results). This particularly applies to benchmarking Python code against C code: the profilers introduce overhead for Python code, but not for C-level functions, and so the C code would seem faster than any Python one.  File: python.info, Node: Instant User’s Manual, Next: profile and cProfile Module Reference, Prev: Introduction to the profilers, Up: The Python Profilers 5.27.5.2 Instant User’s Manual .............................. This section is provided for users that “don’t want to read the manual.” It provides a very brief overview, and allows a user to rapidly perform profiling on an existing application. To profile a function that takes a single argument, you can do: import cProfile import re cProfile.run('re.compile("foo|bar")') (Use *note profile: d3. instead of *note cProfile: 28. if the latter is not available on your system.) The above action would run *note re.compile(): 44a. and print profile results like the following: 197 function calls (192 primitive calls) in 0.002 seconds Ordered by: standard name ncalls tottime percall cumtime percall filename:lineno(function) 1 0.000 0.000 0.001 0.001 <string>:1(<module>) 1 0.000 0.000 0.001 0.001 re.py:212(compile) 1 0.000 0.000 0.001 0.001 re.py:268(_compile) 1 0.000 0.000 0.000 0.000 sre_compile.py:172(_compile_charset) 1 0.000 0.000 0.000 0.000 sre_compile.py:201(_optimize_charset) 4 0.000 0.000 0.000 0.000 sre_compile.py:25(_identityfunction) 3/1 0.000 0.000 0.000 0.000 sre_compile.py:33(_compile) The first line indicates that 197 calls were monitored. Of those calls, 192 were `primitive', meaning that the call was not induced via recursion. The next line: ‘Ordered by: standard name’, indicates that the text string in the far right column was used to sort the output. The column headings include: ncalls for the number of calls. tottime for the total time spent in the given function (and excluding time made in calls to sub-functions) percall is the quotient of ‘tottime’ divided by ‘ncalls’ cumtime is the cumulative time spent in this and all subfunctions (from invocation till exit). This figure is accurate `even' for recursive functions. percall is the quotient of ‘cumtime’ divided by primitive calls filename:lineno(function) provides the respective data of each function When there are two numbers in the first column (for example ‘3/1’), it means that the function recursed. The second value is the number of primitive calls and the former is the total number of calls. Note that when the function does not recurse, these two values are the same, and only the single figure is printed. Instead of printing the output at the end of the profile run, you can save the results to a file by specifying a filename to the ‘run()’ function: import cProfile import re cProfile.run('re.compile("foo|bar")', 'restats') The *note pstats.Stats: 3288. class reads profile results from a file and formats them in various ways. The files *note cProfile: 28. and *note profile: d3. can also be invoked as a script to profile another script. For example: python -m cProfile [-o output_file] [-s sort_order] (-m module | myscript.py) ‘-o’ writes the profile results to a file instead of to stdout ‘-s’ specifies one of the *note sort_stats(): 3289. sort values to sort the output by. This only applies when ‘-o’ is not supplied. ‘-m’ specifies that a module is being profiled instead of a script. New in version 3.7: Added the ‘-m’ option to *note cProfile: 28. New in version 3.8: Added the ‘-m’ option to *note profile: d3. The *note pstats: d4. module’s *note Stats: 3288. class has a variety of methods for manipulating and printing the data saved into a profile results file: import pstats from pstats import SortKey p = pstats.Stats('restats') p.strip_dirs().sort_stats(-1).print_stats() The *note strip_dirs(): 328a. method removed the extraneous path from all the module names. The *note sort_stats(): 3289. method sorted all the entries according to the standard module/line/name string that is printed. The *note print_stats(): 328b. method printed out all the statistics. You might try the following sort calls: p.sort_stats(SortKey.NAME) p.print_stats() The first call will actually sort the list by function name, and the second call will print out the statistics. The following are some interesting calls to experiment with: p.sort_stats(SortKey.CUMULATIVE).print_stats(10) This sorts the profile by cumulative time in a function, and then only prints the ten most significant lines. If you want to understand what algorithms are taking time, the above line is what you would use. If you were looking to see what functions were looping a lot, and taking a lot of time, you would do: p.sort_stats(SortKey.TIME).print_stats(10) to sort according to time spent within each function, and then print the statistics for the top ten functions. You might also try: p.sort_stats(SortKey.FILENAME).print_stats('__init__') This will sort all the statistics by file name, and then print out statistics for only the class init methods (since they are spelled with ‘__init__’ in them). As one final example, you could try: p.sort_stats(SortKey.TIME, SortKey.CUMULATIVE).print_stats(.5, 'init') This line sorts statistics with a primary key of time, and a secondary key of cumulative time, and then prints out some of the statistics. To be specific, the list is first culled down to 50% (re: ‘.5’) of its original size, then only lines containing ‘init’ are maintained, and that sub-sub-list is printed. If you wondered what functions called the above functions, you could now (‘p’ is still sorted according to the last criteria) do: p.print_callers(.5, 'init') and you would get a list of callers for each of the listed functions. If you want more functionality, you’re going to have to read the manual, or guess what the following functions do: p.print_callees() p.add('restats') Invoked as a script, the *note pstats: d4. module is a statistics browser for reading and examining profile dumps. It has a simple line-oriented interface (implemented using *note cmd: 1a.) and interactive help.  File: python.info, Node: profile and cProfile Module Reference, Next: The Stats Class, Prev: Instant User’s Manual, Up: The Python Profilers 5.27.5.3 ‘profile’ and ‘cProfile’ Module Reference .................................................. Both the *note profile: d3. and *note cProfile: 28. modules provide the following functions: -- Function: profile.run (command, filename=None, sort=-1) This function takes a single argument that can be passed to the *note exec(): c44. function, and an optional file name. In all cases this routine executes: exec(command, __main__.__dict__, __main__.__dict__) and gathers profiling statistics from the execution. If no file name is present, then this function automatically creates a *note Stats: 3288. instance and prints a simple profiling report. If the sort value is specified, it is passed to this *note Stats: 3288. instance to control how the results are sorted. -- Function: profile.runctx (command, globals, locals, filename=None, sort=-1) This function is similar to *note run(): 328d, with added arguments to supply the globals and locals dictionaries for the `command' string. This routine executes: exec(command, globals, locals) and gathers profiling statistics as in the *note run(): 328d. function above. -- Class: profile.Profile (timer=None, timeunit=0.0, subcalls=True, builtins=True) This class is normally only used if more precise control over profiling is needed than what the ‘cProfile.run()’ function provides. A custom timer can be supplied for measuring how long code takes to run via the `timer' argument. This must be a function that returns a single number representing the current time. If the number is an integer, the `timeunit' specifies a multiplier that specifies the duration of each unit of time. For example, if the timer returns times measured in thousands of seconds, the time unit would be ‘.001’. Directly using the *note Profile: 1bb. class allows formatting profile results without writing the profile data to a file: import cProfile, pstats, io from pstats import SortKey pr = cProfile.Profile() pr.enable() # ... do something ... pr.disable() s = io.StringIO() sortby = SortKey.CUMULATIVE ps = pstats.Stats(pr, stream=s).sort_stats(sortby) ps.print_stats() print(s.getvalue()) The *note Profile: 1bb. class can also be used as a context manager (supported only in *note cProfile: 28. module. see *note Context Manager Types: 112a.): import cProfile with cProfile.Profile() as pr: # ... do something ... pr.print_stats() Changed in version 3.8: Added context manager support. -- Method: enable () Start collecting profiling data. Only in *note cProfile: 28. -- Method: disable () Stop collecting profiling data. Only in *note cProfile: 28. -- Method: create_stats () Stop collecting profiling data and record the results internally as the current profile. -- Method: print_stats (sort=-1) Create a *note Stats: 3288. object based on the current profile and print the results to stdout. -- Method: dump_stats (filename) Write the results of the current profile to `filename'. -- Method: run (cmd) Profile the cmd via *note exec(): c44. -- Method: runctx (cmd, globals, locals) Profile the cmd via *note exec(): c44. with the specified global and local environment. -- Method: runcall (func, *args, **kwargs) Profile ‘func(*args, **kwargs)’ Note that profiling will only work if the called command/function actually returns. If the interpreter is terminated (e.g. via a *note sys.exit(): ce2. call during the called command/function execution) no profiling results will be printed.  File: python.info, Node: The Stats Class, Next: What Is Deterministic Profiling?, Prev: profile and cProfile Module Reference, Up: The Python Profilers 5.27.5.4 The ‘Stats’ Class .......................... Analysis of the profiler data is done using the *note Stats: 3288. class. -- Class: pstats.Stats (*filenames or profile, stream=sys.stdout) This class constructor creates an instance of a “statistics object” from a `filename' (or list of filenames) or from a ‘Profile’ instance. Output will be printed to the stream specified by `stream'. The file selected by the above constructor must have been created by the corresponding version of *note profile: d3. or *note cProfile: 28. To be specific, there is `no' file compatibility guaranteed with future versions of this profiler, and there is no compatibility with files produced by other profilers, or the same profiler run on a different operating system. If several files are provided, all the statistics for identical functions will be coalesced, so that an overall view of several processes can be considered in a single report. If additional files need to be combined with data in an existing *note Stats: 3288. object, the *note add(): 3298. method can be used. Instead of reading the profile data from a file, a ‘cProfile.Profile’ or *note profile.Profile: 1bb. object can be used as the profile data source. *note Stats: 3288. objects have the following methods: -- Method: strip_dirs () This method for the *note Stats: 3288. class removes all leading path information from file names. It is very useful in reducing the size of the printout to fit within (close to) 80 columns. This method modifies the object, and the stripped information is lost. After performing a strip operation, the object is considered to have its entries in a “random” order, as it was just after object initialization and loading. If *note strip_dirs(): 328a. causes two function names to be indistinguishable (they are on the same line of the same filename, and have the same function name), then the statistics for these two entries are accumulated into a single entry. -- Method: add (*filenames) This method of the *note Stats: 3288. class accumulates additional profiling information into the current profiling object. Its arguments should refer to filenames created by the corresponding version of *note profile.run(): 328d. or ‘cProfile.run()’. Statistics for identically named (re: file, line, name) functions are automatically accumulated into single function statistics. -- Method: dump_stats (filename) Save the data loaded into the *note Stats: 3288. object to a file named `filename'. The file is created if it does not exist, and is overwritten if it already exists. This is equivalent to the method of the same name on the *note profile.Profile: 1bb. and ‘cProfile.Profile’ classes. -- Method: sort_stats (*keys) This method modifies the *note Stats: 3288. object by sorting it according to the supplied criteria. The argument can be either a string or a SortKey enum identifying the basis of a sort (example: ‘'time'’, ‘'name'’, ‘SortKey.TIME’ or ‘SortKey.NAME’). The SortKey enums argument have advantage over the string argument in that it is more robust and less error prone. When more than one key is provided, then additional keys are used as secondary criteria when there is equality in all keys selected before them. For example, ‘sort_stats(SortKey.NAME, SortKey.FILE)’ will sort all the entries according to their function name, and resolve all ties (identical function names) by sorting by file name. For the string argument, abbreviations can be used for any key names, as long as the abbreviation is unambiguous. The following are the valid string and SortKey: Valid String Arg Valid enum Arg Meaning ---------------------------------------------------------------------------- ‘'calls'’ SortKey.CALLS call count ‘'cumulative'’ SortKey.CUMULATIVE cumulative time ‘'cumtime'’ N/A cumulative time ‘'file'’ N/A file name ‘'filename'’ SortKey.FILENAME file name ‘'module'’ N/A file name ‘'ncalls'’ N/A call count ‘'pcalls'’ SortKey.PCALLS primitive call count ‘'line'’ SortKey.LINE line number ‘'name'’ SortKey.NAME function name ‘'nfl'’ SortKey.NFL name/file/line ‘'stdname'’ SortKey.STDNAME standard name ‘'time'’ SortKey.TIME internal time ‘'tottime'’ N/A internal time Note that all sorts on statistics are in descending order (placing most time consuming items first), where as name, file, and line number searches are in ascending order (alphabetical). The subtle distinction between ‘SortKey.NFL’ and ‘SortKey.STDNAME’ is that the standard name is a sort of the name as printed, which means that the embedded line numbers get compared in an odd way. For example, lines 3, 20, and 40 would (if the file names were the same) appear in the string order 20, 3 and 40. In contrast, ‘SortKey.NFL’ does a numeric compare of the line numbers. In fact, ‘sort_stats(SortKey.NFL)’ is the same as ‘sort_stats(SortKey.NAME, SortKey.FILENAME, SortKey.LINE)’. For backward-compatibility reasons, the numeric arguments ‘-1’, ‘0’, ‘1’, and ‘2’ are permitted. They are interpreted as ‘'stdname'’, ‘'calls'’, ‘'time'’, and ‘'cumulative'’ respectively. If this old style format (numeric) is used, only one sort key (the numeric key) will be used, and additional arguments will be silently ignored. New in version 3.7: Added the SortKey enum. -- Method: reverse_order () This method for the *note Stats: 3288. class reverses the ordering of the basic list within the object. Note that by default ascending vs descending order is properly selected based on the sort key of choice. -- Method: print_stats (*restrictions) This method for the *note Stats: 3288. class prints out a report as described in the *note profile.run(): 328d. definition. The order of the printing is based on the last *note sort_stats(): 3289. operation done on the object (subject to caveats in *note add(): 3298. and *note strip_dirs(): 328a.). The arguments provided (if any) can be used to limit the list down to the significant entries. Initially, the list is taken to be the complete set of profiled functions. Each restriction is either an integer (to select a count of lines), or a decimal fraction between 0.0 and 1.0 inclusive (to select a percentage of lines), or a string that will interpreted as a regular expression (to pattern match the standard name that is printed). If several restrictions are provided, then they are applied sequentially. For example: print_stats(.1, 'foo:') would first limit the printing to first 10% of list, and then only print functions that were part of filename ‘.*foo:’. In contrast, the command: print_stats('foo:', .1) would limit the list to all functions having file names ‘.*foo:’, and then proceed to only print the first 10% of them. -- Method: print_callers (*restrictions) This method for the *note Stats: 3288. class prints a list of all functions that called each function in the profiled database. The ordering is identical to that provided by *note print_stats(): 328b, and the definition of the restricting argument is also identical. Each caller is reported on its own line. The format differs slightly depending on the profiler that produced the stats: * With *note profile: d3, a number is shown in parentheses after each caller to show how many times this specific call was made. For convenience, a second non-parenthesized number repeats the cumulative time spent in the function at the right. * With *note cProfile: 28, each caller is preceded by three numbers: the number of times this specific call was made, and the total and cumulative times spent in the current function while it was invoked by this specific caller. -- Method: print_callees (*restrictions) This method for the *note Stats: 3288. class prints a list of all function that were called by the indicated function. Aside from this reversal of direction of calls (re: called vs was called by), the arguments and ordering are identical to the *note print_callers(): 329b. method.  File: python.info, Node: What Is Deterministic Profiling?, Next: Limitations, Prev: The Stats Class, Up: The Python Profilers 5.27.5.5 What Is Deterministic Profiling? ......................................... `Deterministic profiling' is meant to reflect the fact that all `function call', `function return', and `exception' events are monitored, and precise timings are made for the intervals between these events (during which time the user’s code is executing). In contrast, `statistical profiling' (which is not done by this module) randomly samples the effective instruction pointer, and deduces where time is being spent. The latter technique traditionally involves less overhead (as the code does not need to be instrumented), but provides only relative indications of where time is being spent. In Python, since there is an interpreter active during execution, the presence of instrumented code is not required in order to do deterministic profiling. Python automatically provides a `hook' (optional callback) for each event. In addition, the interpreted nature of Python tends to add so much overhead to execution, that deterministic profiling tends to only add small processing overhead in typical applications. The result is that deterministic profiling is not that expensive, yet provides extensive run time statistics about the execution of a Python program. Call count statistics can be used to identify bugs in code (surprising counts), and to identify possible inline-expansion points (high call counts). Internal time statistics can be used to identify “hot loops” that should be carefully optimized. Cumulative time statistics should be used to identify high level errors in the selection of algorithms. Note that the unusual handling of cumulative times in this profiler allows statistics for recursive implementations of algorithms to be directly compared to iterative implementations.  File: python.info, Node: Limitations, Next: Calibration, Prev: What Is Deterministic Profiling?, Up: The Python Profilers 5.27.5.6 Limitations .................... One limitation has to do with accuracy of timing information. There is a fundamental problem with deterministic profilers involving accuracy. The most obvious restriction is that the underlying “clock” is only ticking at a rate (typically) of about .001 seconds. Hence no measurements will be more accurate than the underlying clock. If enough measurements are taken, then the “error” will tend to average out. Unfortunately, removing this first error induces a second source of error. The second problem is that it “takes a while” from when an event is dispatched until the profiler’s call to get the time actually `gets' the state of the clock. Similarly, there is a certain lag when exiting the profiler event handler from the time that the clock’s value was obtained (and then squirreled away), until the user’s code is once again executing. As a result, functions that are called many times, or call many functions, will typically accumulate this error. The error that accumulates in this fashion is typically less than the accuracy of the clock (less than one clock tick), but it `can' accumulate and become very significant. The problem is more important with *note profile: d3. than with the lower-overhead *note cProfile: 28. For this reason, *note profile: d3. provides a means of calibrating itself for a given platform so that this error can be probabilistically (on the average) removed. After the profiler is calibrated, it will be more accurate (in a least square sense), but it will sometimes produce negative numbers (when call counts are exceptionally low, and the gods of probability work against you :-). ) Do `not' be alarmed by negative numbers in the profile. They should `only' appear if you have calibrated your profiler, and the results are actually better than without calibration.  File: python.info, Node: Calibration, Next: Using a custom timer, Prev: Limitations, Up: The Python Profilers 5.27.5.7 Calibration .................... The profiler of the *note profile: d3. module subtracts a constant from each event handling time to compensate for the overhead of calling the time function, and socking away the results. By default, the constant is 0. The following procedure can be used to obtain a better constant for a given platform (see *note Limitations: 32a0.). import profile pr = profile.Profile() for i in range(5): print(pr.calibrate(10000)) The method executes the number of Python calls given by the argument, directly and again under the profiler, measuring the time for both. It then computes the hidden overhead per profiler event, and returns that as a float. For example, on a 1.8Ghz Intel Core i5 running Mac OS X, and using Python’s time.process_time() as the timer, the magical number is about 4.04e-6. The object of this exercise is to get a fairly consistent result. If your computer is `very' fast, or your timer function has poor resolution, you might have to pass 100000, or even 1000000, to get consistent results. When you have a consistent answer, there are three ways you can use it: import profile # 1. Apply computed bias to all Profile instances created hereafter. profile.Profile.bias = your_computed_bias # 2. Apply computed bias to a specific Profile instance. pr = profile.Profile() pr.bias = your_computed_bias # 3. Specify computed bias in instance constructor. pr = profile.Profile(bias=your_computed_bias) If you have a choice, you are better off choosing a smaller constant, and then your results will “less often” show up as negative in profile statistics.  File: python.info, Node: Using a custom timer, Prev: Calibration, Up: The Python Profilers 5.27.5.8 Using a custom timer ............................. If you want to change how current time is determined (for example, to force use of wall-clock time or elapsed process time), pass the timing function you want to the ‘Profile’ class constructor: pr = profile.Profile(your_time_func) The resulting profiler will then call ‘your_time_func’. Depending on whether you are using *note profile.Profile: 1bb. or ‘cProfile.Profile’, ‘your_time_func’’s return value will be interpreted differently: *note profile.Profile: 1bb. ‘your_time_func’ should return a single number, or a list of numbers whose sum is the current time (like what *note os.times(): a5c. returns). If the function returns a single time number, or the list of returned numbers has length 2, then you will get an especially fast version of the dispatch routine. Be warned that you should calibrate the profiler class for the timer function that you choose (see *note Calibration: 32a2.). For most machines, a timer that returns a lone integer value will provide the best results in terms of low overhead during profiling. (*note os.times(): a5c. is `pretty' bad, as it returns a tuple of floating point values). If you want to substitute a better timer in the cleanest fashion, derive a class and hardwire a replacement dispatch method that best handles your timer call, along with the appropriate calibration constant. ‘cProfile.Profile’ ‘your_time_func’ should return a single number. If it returns integers, you can also invoke the class constructor with a second argument specifying the real duration of one unit of time. For example, if ‘your_integer_time_func’ returns times measured in thousands of seconds, you would construct the ‘Profile’ instance as follows: pr = cProfile.Profile(your_integer_time_func, 0.001) As the ‘cProfile.Profile’ class cannot be calibrated, custom timer functions should be used with care and should be as fast as possible. For the best results with a custom timer, it might be necessary to hard-code it in the C source of the internal ‘_lsprof’ module. Python 3.3 adds several new functions in *note time: 10a. that can be used to make precise measurements of process or wall-clock time. For example, see *note time.perf_counter(): 2aa.  File: python.info, Node: timeit — Measure execution time of small code snippets, Next: trace — Trace or track Python statement execution, Prev: The Python Profilers, Up: Debugging and Profiling 5.27.6 ‘timeit’ — Measure execution time of small code snippets --------------------------------------------------------------- `Source code:' Lib/timeit.py(1) __________________________________________________________________ This module provides a simple way to time small bits of Python code. It has both a *note Command-Line Interface: 32a7. as well as a *note callable: 32a8. one. It avoids a number of common traps for measuring execution times. See also Tim Peters’ introduction to the “Algorithms” chapter in the `Python Cookbook', published by O’Reilly. * Menu: * Basic Examples: Basic Examples<2>. * Python Interface:: * Command-Line Interface: Command-Line Interface<4>. * Examples: Examples<25>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/timeit.py  File: python.info, Node: Basic Examples<2>, Next: Python Interface, Up: timeit — Measure execution time of small code snippets 5.27.6.1 Basic Examples ....................... The following example shows how the *note Command-Line Interface: 32a7. can be used to compare three different expressions: $ python3 -m timeit '"-".join(str(n) for n in range(100))' 10000 loops, best of 5: 30.2 usec per loop $ python3 -m timeit '"-".join([str(n) for n in range(100)])' 10000 loops, best of 5: 27.5 usec per loop $ python3 -m timeit '"-".join(map(str, range(100)))' 10000 loops, best of 5: 23.2 usec per loop This can be achieved from the *note Python Interface: 32a8. with: >>> import timeit >>> timeit.timeit('"-".join(str(n) for n in range(100))', number=10000) 0.3018611848820001 >>> timeit.timeit('"-".join([str(n) for n in range(100)])', number=10000) 0.2727368790656328 >>> timeit.timeit('"-".join(map(str, range(100)))', number=10000) 0.23702679807320237 A callable can also be passed from the *note Python Interface: 32a8.: >>> timeit.timeit(lambda: "-".join(map(str, range(100))), number=10000) 0.19665591977536678 Note however that *note timeit(): 771. will automatically determine the number of repetitions only when the command-line interface is used. In the *note Examples: 32aa. section you can find more advanced examples.  File: python.info, Node: Python Interface, Next: Command-Line Interface<4>, Prev: Basic Examples<2>, Up: timeit — Measure execution time of small code snippets 5.27.6.2 Python Interface ......................... The module defines three convenience functions and a public class: -- Function: timeit.timeit (stmt='pass', setup='pass', timer=<default timer>, number=1000000, globals=None) Create a *note Timer: 32ac. instance with the given statement, `setup' code and `timer' function and run its *note timeit(): 59c. method with `number' executions. The optional `globals' argument specifies a namespace in which to execute the code. Changed in version 3.5: The optional `globals' parameter was added. -- Function: timeit.repeat (stmt='pass', setup='pass', timer=<default timer>, repeat=5, number=1000000, globals=None) Create a *note Timer: 32ac. instance with the given statement, `setup' code and `timer' function and run its *note repeat(): 32ae. method with the given `repeat' count and `number' executions. The optional `globals' argument specifies a namespace in which to execute the code. Changed in version 3.5: The optional `globals' parameter was added. Changed in version 3.7: Default value of `repeat' changed from 3 to 5. -- Function: timeit.default_timer () The default timer, which is always *note time.perf_counter(): 2aa. Changed in version 3.3: *note time.perf_counter(): 2aa. is now the default timer. -- Class: timeit.Timer (stmt='pass', setup='pass', timer=<timer function>, globals=None) Class for timing execution speed of small code snippets. The constructor takes a statement to be timed, an additional statement used for setup, and a timer function. Both statements default to ‘'pass'’; the timer function is platform-dependent (see the module doc string). `stmt' and `setup' may also contain multiple statements separated by ‘;’ or newlines, as long as they don’t contain multi-line string literals. The statement will by default be executed within timeit’s namespace; this behavior can be controlled by passing a namespace to `globals'. To measure the execution time of the first statement, use the *note timeit(): 59c. method. The *note repeat(): 32ae. and *note autorange(): 59b. methods are convenience methods to call *note timeit(): 59c. multiple times. The execution time of `setup' is excluded from the overall timed execution run. The `stmt' and `setup' parameters can also take objects that are callable without arguments. This will embed calls to them in a timer function that will then be executed by *note timeit(): 59c. Note that the timing overhead is a little larger in this case because of the extra function calls. Changed in version 3.5: The optional `globals' parameter was added. -- Method: timeit (number=1000000) Time `number' executions of the main statement. This executes the setup statement once, and then returns the time it takes to execute the main statement a number of times, measured in seconds as a float. The argument is the number of times through the loop, defaulting to one million. The main statement, the setup statement and the timer function to be used are passed to the constructor. Note: By default, *note timeit(): 59c. temporarily turns off *note garbage collection: f9f. during the timing. The advantage of this approach is that it makes independent timings more comparable. The disadvantage is that GC may be an important component of the performance of the function being measured. If so, GC can be re-enabled as the first statement in the `setup' string. For example: timeit.Timer('for i in range(10): oct(i)', 'gc.enable()').timeit() -- Method: autorange (callback=None) Automatically determine how many times to call *note timeit(): 59c. This is a convenience function that calls *note timeit(): 59c. repeatedly so that the total time >= 0.2 second, returning the eventual (number of loops, time taken for that number of loops). It calls *note timeit(): 59c. with increasing numbers from the sequence 1, 2, 5, 10, 20, 50, … until the time taken is at least 0.2 second. If `callback' is given and is not ‘None’, it will be called after each trial with two arguments: ‘callback(number, time_taken)’. New in version 3.6. -- Method: repeat (repeat=5, number=1000000) Call *note timeit(): 59c. a few times. This is a convenience function that calls the *note timeit(): 59c. repeatedly, returning a list of results. The first argument specifies how many times to call *note timeit(): 59c. The second argument specifies the `number' argument for *note timeit(): 59c. Note: It’s tempting to calculate mean and standard deviation from the result vector and report these. However, this is not very useful. In a typical case, the lowest value gives a lower bound for how fast your machine can run the given code snippet; higher values in the result vector are typically not caused by variability in Python’s speed, but by other processes interfering with your timing accuracy. So the *note min(): 809. of the result is probably the only number you should be interested in. After that, you should look at the entire vector and apply common sense rather than statistics. Changed in version 3.7: Default value of `repeat' changed from 3 to 5. -- Method: print_exc (file=None) Helper to print a traceback from the timed code. Typical use: t = Timer(...) # outside the try/except try: t.timeit(...) # or t.repeat(...) except Exception: t.print_exc() The advantage over the standard traceback is that source lines in the compiled template will be displayed. The optional `file' argument directs where the traceback is sent; it defaults to *note sys.stderr: 30f.  File: python.info, Node: Command-Line Interface<4>, Next: Examples<25>, Prev: Python Interface, Up: timeit — Measure execution time of small code snippets 5.27.6.3 Command-Line Interface ............................... When called as a program from the command line, the following form is used: python -m timeit [-n N] [-r N] [-u U] [-s S] [-h] [statement ...] Where the following options are understood: -- Program Option: -n N, --number=N how many times to execute ‘statement’ -- Program Option: -r N, --repeat=N how many times to repeat the timer (default 5) -- Program Option: -s S, --setup=S statement to be executed once initially (default ‘pass’) -- Program Option: -p, --process measure process time, not wallclock time, using *note time.process_time(): 2ab. instead of *note time.perf_counter(): 2aa, which is the default New in version 3.3. -- Program Option: -u, --unit=U specify a time unit for timer output; can select nsec, usec, msec, or sec New in version 3.5. -- Program Option: -v, --verbose print raw timing results; repeat for more digits precision -- Program Option: -h, --help print a short usage message and exit A multi-line statement may be given by specifying each line as a separate statement argument; indented lines are possible by enclosing an argument in quotes and using leading spaces. Multiple *note -s: 32b4. options are treated similarly. If *note -n: 32b2. is not given, a suitable number of loops is calculated by trying increasing numbers from the sequence 1, 2, 5, 10, 20, 50, … until the total time is at least 0.2 seconds. *note default_timer(): 32af. measurements can be affected by other programs running on the same machine, so the best thing to do when accurate timing is necessary is to repeat the timing a few times and use the best time. The *note -r: 32b3. option is good for this; the default of 5 repetitions is probably enough in most cases. You can use *note time.process_time(): 2ab. to measure CPU time. Note: There is a certain baseline overhead associated with executing a pass statement. The code here doesn’t try to hide it, but you should be aware of it. The baseline overhead can be measured by invoking the program without arguments, and it might differ between Python versions.  File: python.info, Node: Examples<25>, Prev: Command-Line Interface<4>, Up: timeit — Measure execution time of small code snippets 5.27.6.4 Examples ................. It is possible to provide a setup statement that is executed only once at the beginning: $ python -m timeit -s 'text = "sample string"; char = "g"' 'char in text' 5000000 loops, best of 5: 0.0877 usec per loop $ python -m timeit -s 'text = "sample string"; char = "g"' 'text.find(char)' 1000000 loops, best of 5: 0.342 usec per loop >>> import timeit >>> timeit.timeit('char in text', setup='text = "sample string"; char = "g"') 0.41440500499993504 >>> timeit.timeit('text.find(char)', setup='text = "sample string"; char = "g"') 1.7246671520006203 The same can be done using the *note Timer: 32ac. class and its methods: >>> import timeit >>> t = timeit.Timer('char in text', setup='text = "sample string"; char = "g"') >>> t.timeit() 0.3955516149999312 >>> t.repeat() [0.40183617287970225, 0.37027556854118704, 0.38344867356679524, 0.3712595970846668, 0.37866875250654886] The following examples show how to time expressions that contain multiple lines. Here we compare the cost of using *note hasattr(): 447. vs. *note try: d72./*note except: b3e. to test for missing and present object attributes: $ python -m timeit 'try:' ' str.__bool__' 'except AttributeError:' ' pass' 20000 loops, best of 5: 15.7 usec per loop $ python -m timeit 'if hasattr(str, "__bool__"): pass' 50000 loops, best of 5: 4.26 usec per loop $ python -m timeit 'try:' ' int.__bool__' 'except AttributeError:' ' pass' 200000 loops, best of 5: 1.43 usec per loop $ python -m timeit 'if hasattr(int, "__bool__"): pass' 100000 loops, best of 5: 2.23 usec per loop >>> import timeit >>> # attribute is missing >>> s = """\ ... try: ... str.__bool__ ... except AttributeError: ... pass ... """ >>> timeit.timeit(stmt=s, number=100000) 0.9138244460009446 >>> s = "if hasattr(str, '__bool__'): pass" >>> timeit.timeit(stmt=s, number=100000) 0.5829014980008651 >>> >>> # attribute is present >>> s = """\ ... try: ... int.__bool__ ... except AttributeError: ... pass ... """ >>> timeit.timeit(stmt=s, number=100000) 0.04215312199994514 >>> s = "if hasattr(int, '__bool__'): pass" >>> timeit.timeit(stmt=s, number=100000) 0.08588060699912603 To give the *note timeit: 10b. module access to functions you define, you can pass a `setup' parameter which contains an import statement: def test(): """Stupid test function""" L = [i for i in range(100)] if __name__ == '__main__': import timeit print(timeit.timeit("test()", setup="from __main__ import test")) Another option is to pass *note globals(): 128c. to the `globals' parameter, which will cause the code to be executed within your current global namespace. This can be more convenient than individually specifying imports: def f(x): return x**2 def g(x): return x**4 def h(x): return x**8 import timeit print(timeit.timeit('[func(42) for func in (f,g,h)]', globals=globals()))  File: python.info, Node: trace — Trace or track Python statement execution, Next: tracemalloc — Trace memory allocations, Prev: timeit — Measure execution time of small code snippets, Up: Debugging and Profiling 5.27.7 ‘trace’ — Trace or track Python statement execution ---------------------------------------------------------- `Source code:' Lib/trace.py(1) __________________________________________________________________ The *note trace: 112. module allows you to trace program execution, generate annotated statement coverage listings, print caller/callee relationships and list functions executed during a program run. It can be used in another program or from the command line. See also ........ Coverage.py(2) A popular third-party coverage tool that provides HTML output along with advanced features such as branch coverage. * Menu: * Command-Line Usage:: * Programmatic Interface:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/trace.py (2) https://coverage.readthedocs.io/  File: python.info, Node: Command-Line Usage, Next: Programmatic Interface, Up: trace — Trace or track Python statement execution 5.27.7.1 Command-Line Usage ........................... The *note trace: 112. module can be invoked from the command line. It can be as simple as python -m trace --count -C . somefile.py ... The above will execute ‘somefile.py’ and generate annotated listings of all Python modules imported during the execution into the current directory. -- Program Option: --help Display usage and exit. -- Program Option: --version Display the version of the module and exit. New in version 3.8: Added ‘--module’ option that allows to run an executable module. * Menu: * Main options:: * Modifiers:: * Filters::  File: python.info, Node: Main options, Next: Modifiers, Up: Command-Line Usage 5.27.7.2 Main options ..................... At least one of the following options must be specified when invoking *note trace: 112. The *note –listfuncs: 32c1. option is mutually exclusive with the *note –trace: 32c2. and *note –count: 32c3. options. When *note –listfuncs: 32c1. is provided, neither *note –count: 32c3. nor *note –trace: 32c2. are accepted, and vice versa. -- Program Option: -c, --count Produce a set of annotated listing files upon program completion that shows how many times each statement was executed. See also *note –coverdir: 32c4, *note –file: 32c5. and *note –no-report: 32c6. below. -- Program Option: -t, --trace Display lines as they are executed. -- Program Option: -l, --listfuncs Display the functions executed by running the program. -- Program Option: -r, --report Produce an annotated list from an earlier program run that used the *note –count: 32c3. and *note –file: 32c5. option. This does not execute any code. -- Program Option: -T, --trackcalls Display the calling relationships exposed by running the program.  File: python.info, Node: Modifiers, Next: Filters, Prev: Main options, Up: Command-Line Usage 5.27.7.3 Modifiers .................. -- Program Option: -f, --file=<file> Name of a file to accumulate counts over several tracing runs. Should be used with the *note –count: 32c3. option. -- Program Option: -C, --coverdir=<dir> Directory where the report files go. The coverage report for ‘package.module’ is written to file ‘`dir'/`package'/`module'.cover’. -- Program Option: -m, --missing When generating annotated listings, mark lines which were not executed with ‘>>>>>>’. -- Program Option: -s, --summary When using *note –count: 32c3. or *note –report: 32c7, write a brief summary to stdout for each file processed. -- Program Option: -R, --no-report Do not generate annotated listings. This is useful if you intend to make several runs with *note –count: 32c3, and then produce a single set of annotated listings at the end. -- Program Option: -g, --timing Prefix each line with the time since the program started. Only used while tracing.  File: python.info, Node: Filters, Prev: Modifiers, Up: Command-Line Usage 5.27.7.4 Filters ................ These options may be repeated multiple times. -- Program Option: --ignore-module=<mod> Ignore each of the given module names and its submodules (if it is a package). The argument can be a list of names separated by a comma. -- Program Option: --ignore-dir=<dir> Ignore all modules and packages in the named directory and subdirectories. The argument can be a list of directories separated by *note os.pathsep: ff0.  File: python.info, Node: Programmatic Interface, Prev: Command-Line Usage, Up: trace — Trace or track Python statement execution 5.27.7.5 Programmatic Interface ............................... -- Class: trace.Trace (count=1, trace=1, countfuncs=0, countcallers=0, ignoremods=(), ignoredirs=(), infile=None, outfile=None, timing=False) Create an object to trace execution of a single statement or expression. All parameters are optional. `count' enables counting of line numbers. `trace' enables line execution tracing. `countfuncs' enables listing of the functions called during the run. `countcallers' enables call relationship tracking. `ignoremods' is a list of modules or packages to ignore. `ignoredirs' is a list of directories whose modules or packages should be ignored. `infile' is the name of the file from which to read stored count information. `outfile' is the name of the file in which to write updated count information. `timing' enables a timestamp relative to when tracing was started to be displayed. -- Method: run (cmd) Execute the command and gather statistics from the execution with the current tracing parameters. `cmd' must be a string or code object, suitable for passing into *note exec(): c44. -- Method: runctx (cmd, globals=None, locals=None) Execute the command and gather statistics from the execution with the current tracing parameters, in the defined global and local environments. If not defined, `globals' and `locals' default to empty dictionaries. -- Method: runfunc (func, *args, **kwds) Call `func' with the given arguments under control of the *note Trace: 32d2. object with the current tracing parameters. -- Method: results () Return a *note CoverageResults: 32d6. object that contains the cumulative results of all previous calls to ‘run’, ‘runctx’ and ‘runfunc’ for the given *note Trace: 32d2. instance. Does not reset the accumulated trace results. -- Class: trace.CoverageResults A container for coverage results, created by *note Trace.results(): 32d5. Should not be created directly by the user. -- Method: update (other) Merge in data from another *note CoverageResults: 32d6. object. -- Method: write_results (show_missing=True, summary=False, coverdir=None) Write coverage results. Set `show_missing' to show lines that had no hits. Set `summary' to include in the output the coverage summary per module. `coverdir' specifies the directory into which the coverage result files will be output. If ‘None’, the results for each source file are placed in its directory. A simple example demonstrating the use of the programmatic interface: import sys import trace # create a Trace object, telling it what to ignore, and whether to # do tracing or line-counting or both. tracer = trace.Trace( ignoredirs=[sys.prefix, sys.exec_prefix], trace=0, count=1) # run the new command using the given tracer tracer.run('main()') # make a report, placing output in the current directory r = tracer.results() r.write_results(show_missing=True, coverdir=".")  File: python.info, Node: tracemalloc — Trace memory allocations, Prev: trace — Trace or track Python statement execution, Up: Debugging and Profiling 5.27.8 ‘tracemalloc’ — Trace memory allocations ----------------------------------------------- New in version 3.4. `Source code:' Lib/tracemalloc.py(1) __________________________________________________________________ The tracemalloc module is a debug tool to trace memory blocks allocated by Python. It provides the following information: * Traceback where an object was allocated * Statistics on allocated memory blocks per filename and per line number: total size, number and average size of allocated memory blocks * Compute the differences between two snapshots to detect memory leaks To trace most memory blocks allocated by Python, the module should be started as early as possible by setting the *note PYTHONTRACEMALLOC: ff6. environment variable to ‘1’, or by using *note -X: 155. ‘tracemalloc’ command line option. The *note tracemalloc.start(): fea. function can be called at runtime to start tracing Python memory allocations. By default, a trace of an allocated memory block only stores the most recent frame (1 frame). To store 25 frames at startup: set the *note PYTHONTRACEMALLOC: ff6. environment variable to ‘25’, or use the *note -X: 155. ‘tracemalloc=25’ command line option. * Menu: * Examples: Examples<26>. * API:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tracemalloc.py  File: python.info, Node: Examples<26>, Next: API, Up: tracemalloc — Trace memory allocations 5.27.8.1 Examples ................. * Menu: * Display the top 10:: * Compute differences:: * Get the traceback of a memory block:: * Pretty top::  File: python.info, Node: Display the top 10, Next: Compute differences, Up: Examples<26> 5.27.8.2 Display the top 10 ........................... Display the 10 files allocating the most memory: import tracemalloc tracemalloc.start() # ... run your application ... snapshot = tracemalloc.take_snapshot() top_stats = snapshot.statistics('lineno') print("[ Top 10 ]") for stat in top_stats[:10]: print(stat) Example of output of the Python test suite: [ Top 10 ] <frozen importlib._bootstrap>:716: size=4855 KiB, count=39328, average=126 B <frozen importlib._bootstrap>:284: size=521 KiB, count=3199, average=167 B /usr/lib/python3.4/collections/__init__.py:368: size=244 KiB, count=2315, average=108 B /usr/lib/python3.4/unittest/case.py:381: size=185 KiB, count=779, average=243 B /usr/lib/python3.4/unittest/case.py:402: size=154 KiB, count=378, average=416 B /usr/lib/python3.4/abc.py:133: size=88.7 KiB, count=347, average=262 B <frozen importlib._bootstrap>:1446: size=70.4 KiB, count=911, average=79 B <frozen importlib._bootstrap>:1454: size=52.0 KiB, count=25, average=2131 B <string>:5: size=49.7 KiB, count=148, average=344 B /usr/lib/python3.4/sysconfig.py:411: size=48.0 KiB, count=1, average=48.0 KiB We can see that Python loaded ‘4855 KiB’ data (bytecode and constants) from modules and that the *note collections: 1e. module allocated ‘244 KiB’ to build *note namedtuple: 1b7. types. See *note Snapshot.statistics(): 32dd. for more options.  File: python.info, Node: Compute differences, Next: Get the traceback of a memory block, Prev: Display the top 10, Up: Examples<26> 5.27.8.3 Compute differences ............................ Take two snapshots and display the differences: import tracemalloc tracemalloc.start() # ... start your application ... snapshot1 = tracemalloc.take_snapshot() # ... call the function leaking memory ... snapshot2 = tracemalloc.take_snapshot() top_stats = snapshot2.compare_to(snapshot1, 'lineno') print("[ Top 10 differences ]") for stat in top_stats[:10]: print(stat) Example of output before/after running some tests of the Python test suite: [ Top 10 differences ] <frozen importlib._bootstrap>:716: size=8173 KiB (+4428 KiB), count=71332 (+39369), average=117 B /usr/lib/python3.4/linecache.py:127: size=940 KiB (+940 KiB), count=8106 (+8106), average=119 B /usr/lib/python3.4/unittest/case.py:571: size=298 KiB (+298 KiB), count=589 (+589), average=519 B <frozen importlib._bootstrap>:284: size=1005 KiB (+166 KiB), count=7423 (+1526), average=139 B /usr/lib/python3.4/mimetypes.py:217: size=112 KiB (+112 KiB), count=1334 (+1334), average=86 B /usr/lib/python3.4/http/server.py:848: size=96.0 KiB (+96.0 KiB), count=1 (+1), average=96.0 KiB /usr/lib/python3.4/inspect.py:1465: size=83.5 KiB (+83.5 KiB), count=109 (+109), average=784 B /usr/lib/python3.4/unittest/mock.py:491: size=77.7 KiB (+77.7 KiB), count=143 (+143), average=557 B /usr/lib/python3.4/urllib/parse.py:476: size=71.8 KiB (+71.8 KiB), count=969 (+969), average=76 B /usr/lib/python3.4/contextlib.py:38: size=67.2 KiB (+67.2 KiB), count=126 (+126), average=546 B We can see that Python has loaded ‘8173 KiB’ of module data (bytecode and constants), and that this is ‘4428 KiB’ more than had been loaded before the tests, when the previous snapshot was taken. Similarly, the *note linecache: a8. module has cached ‘940 KiB’ of Python source code to format tracebacks, all of it since the previous snapshot. If the system has little free memory, snapshots can be written on disk using the *note Snapshot.dump(): 32df. method to analyze the snapshot offline. Then use the *note Snapshot.load(): 32e0. method reload the snapshot.  File: python.info, Node: Get the traceback of a memory block, Next: Pretty top, Prev: Compute differences, Up: Examples<26> 5.27.8.4 Get the traceback of a memory block ............................................ Code to display the traceback of the biggest memory block: import tracemalloc # Store 25 frames tracemalloc.start(25) # ... run your application ... snapshot = tracemalloc.take_snapshot() top_stats = snapshot.statistics('traceback') # pick the biggest memory block stat = top_stats[0] print("%s memory blocks: %.1f KiB" % (stat.count, stat.size / 1024)) for line in stat.traceback.format(): print(line) Example of output of the Python test suite (traceback limited to 25 frames): 903 memory blocks: 870.1 KiB File "<frozen importlib._bootstrap>", line 716 File "<frozen importlib._bootstrap>", line 1036 File "<frozen importlib._bootstrap>", line 934 File "<frozen importlib._bootstrap>", line 1068 File "<frozen importlib._bootstrap>", line 619 File "<frozen importlib._bootstrap>", line 1581 File "<frozen importlib._bootstrap>", line 1614 File "/usr/lib/python3.4/doctest.py", line 101 import pdb File "<frozen importlib._bootstrap>", line 284 File "<frozen importlib._bootstrap>", line 938 File "<frozen importlib._bootstrap>", line 1068 File "<frozen importlib._bootstrap>", line 619 File "<frozen importlib._bootstrap>", line 1581 File "<frozen importlib._bootstrap>", line 1614 File "/usr/lib/python3.4/test/support/__init__.py", line 1728 import doctest File "/usr/lib/python3.4/test/test_pickletools.py", line 21 support.run_doctest(pickletools) File "/usr/lib/python3.4/test/regrtest.py", line 1276 test_runner() File "/usr/lib/python3.4/test/regrtest.py", line 976 display_failure=not verbose) File "/usr/lib/python3.4/test/regrtest.py", line 761 match_tests=ns.match_tests) File "/usr/lib/python3.4/test/regrtest.py", line 1563 main() File "/usr/lib/python3.4/test/__main__.py", line 3 regrtest.main_in_temp_cwd() File "/usr/lib/python3.4/runpy.py", line 73 exec(code, run_globals) File "/usr/lib/python3.4/runpy.py", line 160 "__main__", fname, loader, pkg_name) We can see that the most memory was allocated in the *note importlib: 9b. module to load data (bytecode and constants) from modules: ‘870.1 KiB’. The traceback is where the *note importlib: 9b. loaded data most recently: on the ‘import pdb’ line of the *note doctest: 67. module. The traceback may change if a new module is loaded.  File: python.info, Node: Pretty top, Prev: Get the traceback of a memory block, Up: Examples<26> 5.27.8.5 Pretty top ................... Code to display the 10 lines allocating the most memory with a pretty output, ignoring ‘<frozen importlib._bootstrap>’ and ‘<unknown>’ files: import linecache import os import tracemalloc def display_top(snapshot, key_type='lineno', limit=10): snapshot = snapshot.filter_traces(( tracemalloc.Filter(False, "<frozen importlib._bootstrap>"), tracemalloc.Filter(False, "<unknown>"), )) top_stats = snapshot.statistics(key_type) print("Top %s lines" % limit) for index, stat in enumerate(top_stats[:limit], 1): frame = stat.traceback[0] print("#%s: %s:%s: %.1f KiB" % (index, frame.filename, frame.lineno, stat.size / 1024)) line = linecache.getline(frame.filename, frame.lineno).strip() if line: print(' %s' % line) other = top_stats[limit:] if other: size = sum(stat.size for stat in other) print("%s other: %.1f KiB" % (len(other), size / 1024)) total = sum(stat.size for stat in top_stats) print("Total allocated size: %.1f KiB" % (total / 1024)) tracemalloc.start() # ... run your application ... snapshot = tracemalloc.take_snapshot() display_top(snapshot) Example of output of the Python test suite: Top 10 lines #1: Lib/base64.py:414: 419.8 KiB _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars] #2: Lib/base64.py:306: 419.8 KiB _a85chars2 = [(a + b) for a in _a85chars for b in _a85chars] #3: collections/__init__.py:368: 293.6 KiB exec(class_definition, namespace) #4: Lib/abc.py:133: 115.2 KiB cls = super().__new__(mcls, name, bases, namespace) #5: unittest/case.py:574: 103.1 KiB testMethod() #6: Lib/linecache.py:127: 95.4 KiB lines = fp.readlines() #7: urllib/parse.py:476: 71.8 KiB for a in _hexdig for b in _hexdig} #8: <string>:5: 62.0 KiB #9: Lib/_weakrefset.py:37: 60.0 KiB self.data = set() #10: Lib/base64.py:142: 59.8 KiB _b32tab2 = [a + b for a in _b32tab for b in _b32tab] 6220 other: 3602.8 KiB Total allocated size: 5303.1 KiB See *note Snapshot.statistics(): 32dd. for more options.  File: python.info, Node: API, Prev: Examples<26>, Up: tracemalloc — Trace memory allocations 5.27.8.6 API ............ * Menu: * Functions: Functions<9>. * DomainFilter:: * Filter:: * Frame:: * Snapshot:: * Statistic:: * StatisticDiff:: * Trace:: * Traceback::  File: python.info, Node: Functions<9>, Next: DomainFilter, Up: API 5.27.8.7 Functions .................. -- Function: tracemalloc.clear_traces () Clear traces of memory blocks allocated by Python. See also *note stop(): 32e6. -- Function: tracemalloc.get_object_traceback (obj) Get the traceback where the Python object `obj' was allocated. Return a *note Traceback: 3ff. instance, or ‘None’ if the *note tracemalloc: 114. module is not tracing memory allocations or did not trace the allocation of the object. See also *note gc.get_referrers(): 31f5. and *note sys.getsizeof(): 32e8. functions. -- Function: tracemalloc.get_traceback_limit () Get the maximum number of frames stored in the traceback of a trace. The *note tracemalloc: 114. module must be tracing memory allocations to get the limit, otherwise an exception is raised. The limit is set by the *note start(): fea. function. -- Function: tracemalloc.get_traced_memory () Get the current size and peak size of memory blocks traced by the *note tracemalloc: 114. module as a tuple: ‘(current: int, peak: int)’. -- Function: tracemalloc.get_tracemalloc_memory () Get the memory usage in bytes of the *note tracemalloc: 114. module used to store traces of memory blocks. Return an *note int: 184. -- Function: tracemalloc.is_tracing () ‘True’ if the *note tracemalloc: 114. module is tracing Python memory allocations, ‘False’ otherwise. See also *note start(): fea. and *note stop(): 32e6. functions. -- Function: tracemalloc.start (nframe: int=1) Start tracing Python memory allocations: install hooks on Python memory allocators. Collected tracebacks of traces will be limited to `nframe' frames. By default, a trace of a memory block only stores the most recent frame: the limit is ‘1’. `nframe' must be greater or equal to ‘1’. Storing more than ‘1’ frame is only useful to compute statistics grouped by ‘'traceback'’ or to compute cumulative statistics: see the *note Snapshot.compare_to(): 32ed. and *note Snapshot.statistics(): 32dd. methods. Storing more frames increases the memory and CPU overhead of the *note tracemalloc: 114. module. Use the *note get_tracemalloc_memory(): 32eb. function to measure how much memory is used by the *note tracemalloc: 114. module. The *note PYTHONTRACEMALLOC: ff6. environment variable (‘PYTHONTRACEMALLOC=NFRAME’) and the *note -X: 155. ‘tracemalloc=NFRAME’ command line option can be used to start tracing at startup. See also *note stop(): 32e6, *note is_tracing(): 32ec. and *note get_traceback_limit(): 32e9. functions. -- Function: tracemalloc.stop () Stop tracing Python memory allocations: uninstall hooks on Python memory allocators. Also clears all previously collected traces of memory blocks allocated by Python. Call *note take_snapshot(): 32ee. function to take a snapshot of traces before clearing them. See also *note start(): fea, *note is_tracing(): 32ec. and *note clear_traces(): 32e5. functions. -- Function: tracemalloc.take_snapshot () Take a snapshot of traces of memory blocks allocated by Python. Return a new *note Snapshot: 32ef. instance. The snapshot does not include memory blocks allocated before the *note tracemalloc: 114. module started to trace memory allocations. Tracebacks of traces are limited to *note get_traceback_limit(): 32e9. frames. Use the `nframe' parameter of the *note start(): fea. function to store more frames. The *note tracemalloc: 114. module must be tracing memory allocations to take a snapshot, see the *note start(): fea. function. See also the *note get_object_traceback(): 32e7. function.  File: python.info, Node: DomainFilter, Next: Filter, Prev: Functions<9>, Up: API 5.27.8.8 DomainFilter ..................... -- Class: tracemalloc.DomainFilter (inclusive: bool, domain: int) Filter traces of memory blocks by their address space (domain). New in version 3.6. -- Attribute: inclusive If `inclusive' is ‘True’ (include), match memory blocks allocated in the address space *note domain: 32f2. If `inclusive' is ‘False’ (exclude), match memory blocks not allocated in the address space *note domain: 32f2. -- Attribute: domain Address space of a memory block (‘int’). Read-only property.  File: python.info, Node: Filter, Next: Frame, Prev: DomainFilter, Up: API 5.27.8.9 Filter ............... -- Class: tracemalloc.Filter (inclusive: bool, filename_pattern: str, lineno: int=None, all_frames: bool=False, domain: int=None) Filter on traces of memory blocks. See the *note fnmatch.fnmatch(): 1935. function for the syntax of `filename_pattern'. The ‘'.pyc'’ file extension is replaced with ‘'.py'’. Examples: * ‘Filter(True, subprocess.__file__)’ only includes traces of the *note subprocess: f9. module * ‘Filter(False, tracemalloc.__file__)’ excludes traces of the *note tracemalloc: 114. module * ‘Filter(False, "<unknown>")’ excludes empty tracebacks Changed in version 3.5: The ‘'.pyo'’ file extension is no longer replaced with ‘'.py'’. Changed in version 3.6: Added the *note domain: 32f5. attribute. -- Attribute: domain Address space of a memory block (‘int’ or ‘None’). tracemalloc uses the domain ‘0’ to trace memory allocations made by Python. C extensions can use other domains to trace other resources. -- Attribute: inclusive If `inclusive' is ‘True’ (include), only match memory blocks allocated in a file with a name matching *note filename_pattern: 32f7. at line number *note lineno: 32f8. If `inclusive' is ‘False’ (exclude), ignore memory blocks allocated in a file with a name matching *note filename_pattern: 32f7. at line number *note lineno: 32f8. -- Attribute: lineno Line number (‘int’) of the filter. If `lineno' is ‘None’, the filter matches any line number. -- Attribute: filename_pattern Filename pattern of the filter (‘str’). Read-only property. -- Attribute: all_frames If `all_frames' is ‘True’, all frames of the traceback are checked. If `all_frames' is ‘False’, only the most recent frame is checked. This attribute has no effect if the traceback limit is ‘1’. See the *note get_traceback_limit(): 32e9. function and *note Snapshot.traceback_limit: 32fa. attribute.  File: python.info, Node: Frame, Next: Snapshot, Prev: Filter, Up: API 5.27.8.10 Frame ............... -- Class: tracemalloc.Frame Frame of a traceback. The *note Traceback: 3ff. class is a sequence of *note Frame: 32fc. instances. -- Attribute: filename Filename (‘str’). -- Attribute: lineno Line number (‘int’).  File: python.info, Node: Snapshot, Next: Statistic, Prev: Frame, Up: API 5.27.8.11 Snapshot .................. -- Class: tracemalloc.Snapshot Snapshot of traces of memory blocks allocated by Python. The *note take_snapshot(): 32ee. function creates a snapshot instance. -- Method: compare_to (old_snapshot: Snapshot, key_type: str, cumulative: bool=False) Compute the differences with an old snapshot. Get statistics as a sorted list of *note StatisticDiff: 3300. instances grouped by `key_type'. See the *note Snapshot.statistics(): 32dd. method for `key_type' and `cumulative' parameters. The result is sorted from the biggest to the smallest by: absolute value of *note StatisticDiff.size_diff: 3301, *note StatisticDiff.size: 3302, absolute value of *note StatisticDiff.count_diff: 3303, *note Statistic.count: 3304. and then by *note StatisticDiff.traceback: 3305. -- Method: dump (filename) Write the snapshot into a file. Use *note load(): 32e0. to reload the snapshot. -- Method: filter_traces (filters) Create a new *note Snapshot: 32ef. instance with a filtered *note traces: 3307. sequence, `filters' is a list of *note DomainFilter: 5a0. and *note Filter: 32f4. instances. If `filters' is an empty list, return a new *note Snapshot: 32ef. instance with a copy of the traces. All inclusive filters are applied at once, a trace is ignored if no inclusive filters match it. A trace is ignored if at least one exclusive filter matches it. Changed in version 3.6: *note DomainFilter: 5a0. instances are now also accepted in `filters'. -- Method: classmethod load (filename) Load a snapshot from a file. See also *note dump(): 32df. -- Method: statistics (key_type: str, cumulative: bool=False) Get statistics as a sorted list of *note Statistic: 3308. instances grouped by `key_type': key_type description ------------------------------------------------------- ‘'filename'’ filename ‘'lineno'’ filename and line number ‘'traceback'’ traceback If `cumulative' is ‘True’, cumulate size and count of memory blocks of all frames of the traceback of a trace, not only the most recent frame. The cumulative mode can only be used with `key_type' equals to ‘'filename'’ and ‘'lineno'’. The result is sorted from the biggest to the smallest by: *note Statistic.size: 3309, *note Statistic.count: 3304. and then by *note Statistic.traceback: 330a. -- Attribute: traceback_limit Maximum number of frames stored in the traceback of *note traces: 3307.: result of the *note get_traceback_limit(): 32e9. when the snapshot was taken. -- Attribute: traces Traces of all memory blocks allocated by Python: sequence of *note Trace: 330b. instances. The sequence has an undefined order. Use the *note Snapshot.statistics(): 32dd. method to get a sorted list of statistics.  File: python.info, Node: Statistic, Next: StatisticDiff, Prev: Snapshot, Up: API 5.27.8.12 Statistic ................... -- Class: tracemalloc.Statistic Statistic on memory allocations. *note Snapshot.statistics(): 32dd. returns a list of *note Statistic: 3308. instances. See also the *note StatisticDiff: 3300. class. -- Attribute: count Number of memory blocks (‘int’). -- Attribute: size Total size of memory blocks in bytes (‘int’). -- Attribute: traceback Traceback where the memory block was allocated, *note Traceback: 3ff. instance.  File: python.info, Node: StatisticDiff, Next: Trace, Prev: Statistic, Up: API 5.27.8.13 StatisticDiff ....................... -- Class: tracemalloc.StatisticDiff Statistic difference on memory allocations between an old and a new *note Snapshot: 32ef. instance. *note Snapshot.compare_to(): 32ed. returns a list of *note StatisticDiff: 3300. instances. See also the *note Statistic: 3308. class. -- Attribute: count Number of memory blocks in the new snapshot (‘int’): ‘0’ if the memory blocks have been released in the new snapshot. -- Attribute: count_diff Difference of number of memory blocks between the old and the new snapshots (‘int’): ‘0’ if the memory blocks have been allocated in the new snapshot. -- Attribute: size Total size of memory blocks in bytes in the new snapshot (‘int’): ‘0’ if the memory blocks have been released in the new snapshot. -- Attribute: size_diff Difference of total size of memory blocks in bytes between the old and the new snapshots (‘int’): ‘0’ if the memory blocks have been allocated in the new snapshot. -- Attribute: traceback Traceback where the memory blocks were allocated, *note Traceback: 3ff. instance.  File: python.info, Node: Trace, Next: Traceback, Prev: StatisticDiff, Up: API 5.27.8.14 Trace ............... -- Class: tracemalloc.Trace Trace of a memory block. The *note Snapshot.traces: 3307. attribute is a sequence of *note Trace: 330b. instances. Changed in version 3.6: Added the *note domain: 3310. attribute. -- Attribute: domain Address space of a memory block (‘int’). Read-only property. tracemalloc uses the domain ‘0’ to trace memory allocations made by Python. C extensions can use other domains to trace other resources. -- Attribute: size Size of the memory block in bytes (‘int’). -- Attribute: traceback Traceback where the memory block was allocated, *note Traceback: 3ff. instance.  File: python.info, Node: Traceback, Prev: Trace, Up: API 5.27.8.15 Traceback ................... -- Class: tracemalloc.Traceback Sequence of *note Frame: 32fc. instances sorted from the oldest frame to the most recent frame. A traceback contains at least ‘1’ frame. If the ‘tracemalloc’ module failed to get a frame, the filename ‘"<unknown>"’ at line number ‘0’ is used. When a snapshot is taken, tracebacks of traces are limited to *note get_traceback_limit(): 32e9. frames. See the *note take_snapshot(): 32ee. function. The *note Trace.traceback: 3312. attribute is an instance of *note Traceback: 3ff. instance. Changed in version 3.7: Frames are now sorted from the oldest to the most recent, instead of most recent to oldest. -- Method: format (limit=None, most_recent_first=False) Format the traceback as a list of lines with newlines. Use the *note linecache: a8. module to retrieve lines from the source code. If `limit' is set, format the `limit' most recent frames if `limit' is positive. Otherwise, format the ‘abs(limit)’ oldest frames. If `most_recent_first' is ‘True’, the order of the formatted frames is reversed, returning the most recent frame first instead of last. Similar to the *note traceback.format_tb(): 3314. function, except that *note format(): 400. does not include newlines. Example: print("Traceback (most recent call first):") for line in traceback: print(line) Output: Traceback (most recent call first): File "test.py", line 9 obj = Object() File "test.py", line 12 tb = tracemalloc.get_object_traceback(f())  File: python.info, Node: Software Packaging and Distribution, Next: Python Runtime Services, Prev: Debugging and Profiling, Up: The Python Standard Library 5.28 Software Packaging and Distribution ======================================== These libraries help you with publishing and installing Python software. While these modules are designed to work in conjunction with the Python Package Index(1), they can also be used with a local index server, or without any index server at all. * Menu: * distutils — Building and installing Python modules:: * ensurepip — Bootstrapping the pip installer:: * venv — Creation of virtual environments:: * zipapp — Manage executable Python zip archives:: ---------- Footnotes ---------- (1) https://pypi.org  File: python.info, Node: distutils — Building and installing Python modules, Next: ensurepip — Bootstrapping the pip installer, Up: Software Packaging and Distribution 5.28.1 ‘distutils’ — Building and installing Python modules ----------------------------------------------------------- __________________________________________________________________ The *note distutils: 39. package provides support for building and installing additional modules into a Python installation. The new modules may be either 100%-pure Python, or may be extension modules written in C, or may be collections of Python packages which include modules coded in both Python and C. Most Python users will `not' want to use this module directly, but instead use the cross-version tools maintained by the Python Packaging Authority. In particular, setuptools(1) is an enhanced alternative to *note distutils: 39. that provides: * support for declaring project dependencies * additional mechanisms for configuring which files to include in source releases (including plugins for integration with version control systems) * the ability to declare project “entry points”, which can be used as the basis for application plugin systems * the ability to automatically generate Windows command line executables at installation time rather than needing to prebuild them * consistent behaviour across all supported Python versions The recommended pip(2) installer runs all ‘setup.py’ scripts with ‘setuptools’, even if the script itself only imports ‘distutils’. Refer to the Python Packaging User Guide(3) for more information. For the benefits of packaging tool authors and users seeking a deeper understanding of the details of the current packaging and distribution system, the legacy *note distutils: 39. based user documentation and API reference remain available: * *note Installing Python Modules (Legacy version): 7f7. * *note Distributing Python Modules (Legacy version): 7f8. ---------- Footnotes ---------- (1) https://setuptools.readthedocs.io/en/latest/ (2) https://pip.pypa.io/ (3) https://packaging.python.org  File: python.info, Node: ensurepip — Bootstrapping the pip installer, Next: venv — Creation of virtual environments, Prev: distutils — Building and installing Python modules, Up: Software Packaging and Distribution 5.28.2 ‘ensurepip’ — Bootstrapping the ‘pip’ installer ------------------------------------------------------ New in version 3.4. __________________________________________________________________ The *note ensurepip: 7a. package provides support for bootstrapping the ‘pip’ installer into an existing Python installation or virtual environment. This bootstrapping approach reflects the fact that ‘pip’ is an independent project with its own release cycle, and the latest available stable version is bundled with maintenance and feature releases of the CPython reference interpreter. In most cases, end users of Python shouldn’t need to invoke this module directly (as ‘pip’ should be bootstrapped by default), but it may be needed if installing ‘pip’ was skipped when installing Python (or when creating a virtual environment) or after explicitly uninstalling ‘pip’. Note: This module `does not' access the internet. All of the components needed to bootstrap ‘pip’ are included as internal parts of the package. See also ........ *note Installing Python Modules: 7f5. The end user guide for installing Python packages PEP 453(1): Explicit bootstrapping of pip in Python installations The original rationale and specification for this module. * Menu: * Command line interface:: * Module API:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0453  File: python.info, Node: Command line interface, Next: Module API, Up: ensurepip — Bootstrapping the pip installer 5.28.2.1 Command line interface ............................... The command line interface is invoked using the interpreter’s ‘-m’ switch. The simplest possible invocation is: python -m ensurepip This invocation will install ‘pip’ if it is not already installed, but otherwise does nothing. To ensure the installed version of ‘pip’ is at least as recent as the one bundled with ‘ensurepip’, pass the ‘--upgrade’ option: python -m ensurepip --upgrade By default, ‘pip’ is installed into the current virtual environment (if one is active) or into the system site packages (if there is no active virtual environment). The installation location can be controlled through two additional command line options: * ‘--root <dir>’: Installs ‘pip’ relative to the given root directory rather than the root of the currently active virtual environment (if any) or the default root for the current Python installation. * ‘--user’: Installs ‘pip’ into the user site packages directory rather than globally for the current Python installation (this option is not permitted inside an active virtual environment). By default, the scripts ‘pipX’ and ‘pipX.Y’ will be installed (where X.Y stands for the version of Python used to invoke ‘ensurepip’). The scripts installed can be controlled through two additional command line options: * ‘--altinstall’: if an alternate installation is requested, the ‘pipX’ script will `not' be installed. * ‘--default-pip’: if a “default pip” installation is requested, the ‘pip’ script will be installed in addition to the two regular scripts. Providing both of the script selection options will trigger an exception.  File: python.info, Node: Module API, Prev: Command line interface, Up: ensurepip — Bootstrapping the pip installer 5.28.2.2 Module API ................... *note ensurepip: 7a. exposes two functions for programmatic use: -- Function: ensurepip.version () Returns a string specifying the bundled version of pip that will be installed when bootstrapping an environment. -- Function: ensurepip.bootstrap (root=None, upgrade=False, user=False, altinstall=False, default_pip=False, verbosity=0) Bootstraps ‘pip’ into the current or designated environment. `root' specifies an alternative root directory to install relative to. If `root' is ‘None’, then installation uses the default install location for the current environment. `upgrade' indicates whether or not to upgrade an existing installation of an earlier version of ‘pip’ to the bundled version. `user' indicates whether to use the user scheme rather than installing globally. By default, the scripts ‘pipX’ and ‘pipX.Y’ will be installed (where X.Y stands for the current version of Python). If `altinstall' is set, then ‘pipX’ will `not' be installed. If `default_pip' is set, then ‘pip’ will be installed in addition to the two regular scripts. Setting both `altinstall' and `default_pip' will trigger *note ValueError: 1fb. `verbosity' controls the level of output to *note sys.stdout: 30e. from the bootstrapping operation. Raises an *note auditing event: fd1. ‘ensurepip.bootstrap’ with argument ‘root’. Note: The bootstrapping process has side effects on both ‘sys.path’ and ‘os.environ’. Invoking the command line interface in a subprocess instead allows these side effects to be avoided. Note: The bootstrapping process may install additional modules required by ‘pip’, but other software should not assume those dependencies will always be present by default (as the dependencies may be removed in a future version of ‘pip’).  File: python.info, Node: venv — Creation of virtual environments, Next: zipapp — Manage executable Python zip archives, Prev: ensurepip — Bootstrapping the pip installer, Up: Software Packaging and Distribution 5.28.3 ‘venv’ — Creation of virtual environments ------------------------------------------------ New in version 3.3. `Source code:' Lib/venv/(1) __________________________________________________________________ The *note venv: 125. module provides support for creating lightweight “virtual environments” with their own site directories, optionally isolated from system site directories. Each virtual environment has its own Python binary (which matches the version of the binary that was used to create this environment) and can have its own independent set of installed Python packages in its site directories. See PEP 405(2) for more information about Python virtual environments. See also ........ Python Packaging User Guide: Creating and using virtual environments(3) * Menu: * Creating virtual environments:: * API: API<2>. * An example of extending EnvBuilder:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/venv/ (2) https://www.python.org/dev/peps/pep-0405 (3) https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/#creating-a-virtual-environment  File: python.info, Node: Creating virtual environments, Next: API<2>, Up: venv — Creation of virtual environments 5.28.3.1 Creating virtual environments ...................................... Creation of *note virtual environments: 3321. is done by executing the command ‘venv’: python3 -m venv /path/to/new/virtual/environment Running this command creates the target directory (creating any parent directories that don’t exist already) and places a ‘pyvenv.cfg’ file in it with a ‘home’ key pointing to the Python installation from which the command was run (a common name for the target directory is ‘.venv’). It also creates a ‘bin’ (or ‘Scripts’ on Windows) subdirectory containing a copy/symlink of the Python binary/binaries (as appropriate for the platform or arguments used at environment creation time). It also creates an (initially empty) ‘lib/pythonX.Y/site-packages’ subdirectory (on Windows, this is ‘Lib\site-packages’). If an existing directory is specified, it will be re-used. Deprecated since version 3.6: ‘pyvenv’ was the recommended tool for creating virtual environments for Python 3.3 and 3.4, and is deprecated in Python 3.6(1). Changed in version 3.5: The use of ‘venv’ is now recommended for creating virtual environments. On Windows, invoke the ‘venv’ command as follows: c:\>c:\Python35\python -m venv c:\path\to\myenv Alternatively, if you configured the ‘PATH’ and ‘PATHEXT’ variables for your *note Python installation: 2d9.: c:\>python -m venv c:\path\to\myenv The command, if run with ‘-h’, will show the available options: usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear] [--upgrade] [--without-pip] [--prompt PROMPT] ENV_DIR [ENV_DIR ...] Creates virtual Python environments in one or more target directories. positional arguments: ENV_DIR A directory to create the environment in. optional arguments: -h, --help show this help message and exit --system-site-packages Give the virtual environment access to the system site-packages dir. --symlinks Try to use symlinks rather than copies, when symlinks are not the default for the platform. --copies Try to use copies rather than symlinks, even when symlinks are the default for the platform. --clear Delete the contents of the environment directory if it already exists, before environment creation. --upgrade Upgrade the environment directory to use this version of Python, assuming Python has been upgraded in-place. --without-pip Skips installing or upgrading pip in the virtual environment (pip is bootstrapped by default) --prompt PROMPT Provides an alternative prompt prefix for this environment. Once an environment has been created, you may wish to activate it, e.g. by sourcing an activate script in its bin directory. Changed in version 3.4: Installs pip by default, added the ‘--without-pip’ and ‘--copies’ options Changed in version 3.4: In earlier versions, if the target directory already existed, an error was raised, unless the ‘--clear’ or ‘--upgrade’ option was provided. Note: While symlinks are supported on Windows, they are not recommended. Of particular note is that double-clicking ‘python.exe’ in File Explorer will resolve the symlink eagerly and ignore the virtual environment. Note: On Microsoft Windows, it may be required to enable the ‘Activate.ps1’ script by setting the execution policy for the user. You can do this by issuing the following PowerShell command: PS C:> Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser See About Execution Policies(2) for more information. The created ‘pyvenv.cfg’ file also includes the ‘include-system-site-packages’ key, set to ‘true’ if ‘venv’ is run with the ‘--system-site-packages’ option, ‘false’ otherwise. Unless the ‘--without-pip’ option is given, *note ensurepip: 7a. will be invoked to bootstrap ‘pip’ into the virtual environment. Multiple paths can be given to ‘venv’, in which case an identical virtual environment will be created, according to the given options, at each provided path. Once a virtual environment has been created, it can be “activated” using a script in the virtual environment’s binary directory. The invocation of the script is platform-specific (‘<venv>’ must be replaced by the path of the directory containing the virtual environment): Platform Shell Command to activate virtual environment -------------------------------------------------------------------------------------- POSIX bash/zsh $ source <venv>/bin/activate fish $ . <venv>/bin/activate.fish csh/tcsh $ source <venv>/bin/activate.csh PowerShell Core $ <venv>/bin/Activate.ps1 Windows cmd.exe C:\> <venv>\Scripts\activate.bat PowerShell PS C:\> <venv>\Scripts\Activate.ps1 When a virtual environment is active, the ‘VIRTUAL_ENV’ environment variable is set to the path of the virtual environment. This can be used to check if one is running inside a virtual environment. You don’t specifically `need' to activate an environment; activation just prepends the virtual environment’s binary directory to your path, so that “python” invokes the virtual environment’s Python interpreter and you can run installed scripts without having to use their full path. However, all scripts installed in a virtual environment should be runnable without activating it, and run with the virtual environment’s Python automatically. You can deactivate a virtual environment by typing “deactivate” in your shell. The exact mechanism is platform-specific and is an internal implementation detail (typically a script or shell function will be used). New in version 3.4: ‘fish’ and ‘csh’ activation scripts. New in version 3.8: PowerShell activation scripts installed under POSIX for PowerShell Core support. Note: A virtual environment is a Python environment such that the Python interpreter, libraries and scripts installed into it are isolated from those installed in other virtual environments, and (by default) any libraries installed in a “system” Python, i.e., one which is installed as part of your operating system. A virtual environment is a directory tree which contains Python executable files and other files which indicate that it is a virtual environment. Common installation tools such as setuptools(3) and pip(4) work as expected with virtual environments. In other words, when a virtual environment is active, they install Python packages into the virtual environment without needing to be told to do so explicitly. When a virtual environment is active (i.e., the virtual environment’s Python interpreter is running), the attributes *note sys.prefix: 3322. and *note sys.exec_prefix: 3323. point to the base directory of the virtual environment, whereas *note sys.base_prefix: 2d50. and *note sys.base_exec_prefix: 3324. point to the non-virtual environment Python installation which was used to create the virtual environment. If a virtual environment is not active, then *note sys.prefix: 3322. is the same as *note sys.base_prefix: 2d50. and *note sys.exec_prefix: 3323. is the same as *note sys.base_exec_prefix: 3324. (they all point to a non-virtual environment Python installation). When a virtual environment is active, any options that change the installation path will be ignored from all *note distutils: 39. configuration files to prevent projects being inadvertently installed outside of the virtual environment. When working in a command shell, users can make a virtual environment active by running an ‘activate’ script in the virtual environment’s executables directory (the precise filename and command to use the file is shell-dependent), which prepends the virtual environment’s directory for executables to the ‘PATH’ environment variable for the running shell. There should be no need in other circumstances to activate a virtual environment; scripts installed into virtual environments have a “shebang” line which points to the virtual environment’s Python interpreter. This means that the script will run with that interpreter regardless of the value of ‘PATH’. On Windows, “shebang” line processing is supported if you have the Python Launcher for Windows installed (this was added to Python in 3.3 - see PEP 397(5) for more details). Thus, double-clicking an installed script in a Windows Explorer window should run the script with the correct interpreter without there needing to be any reference to its virtual environment in ‘PATH’. ---------- Footnotes ---------- (1) https://docs.python.org/dev/whatsnew/3.6.html#deprecated-features (2) https://go.microsoft.com/fwlink/?LinkID=135170 (3) https://pypi.org/project/setuptools/ (4) https://pypi.org/project/pip/ (5) https://www.python.org/dev/peps/pep-0397  File: python.info, Node: API<2>, Next: An example of extending EnvBuilder, Prev: Creating virtual environments, Up: venv — Creation of virtual environments 5.28.3.2 API ............ The high-level method described above makes use of a simple API which provides mechanisms for third-party virtual environment creators to customize environment creation according to their needs, the *note EnvBuilder: 908. class. -- Class: venv.EnvBuilder (system_site_packages=False, clear=False, symlinks=False, upgrade=False, with_pip=False, prompt=None) The *note EnvBuilder: 908. class accepts the following keyword arguments on instantiation: * ‘system_site_packages’ – a Boolean value indicating that the system Python site-packages should be available to the environment (defaults to ‘False’). * ‘clear’ – a Boolean value which, if true, will delete the contents of any existing target directory, before creating the environment. * ‘symlinks’ – a Boolean value indicating whether to attempt to symlink the Python binary rather than copying. * ‘upgrade’ – a Boolean value which, if true, will upgrade an existing environment with the running Python - for use when that Python has been upgraded in-place (defaults to ‘False’). * ‘with_pip’ – a Boolean value which, if true, ensures pip is installed in the virtual environment. This uses *note ensurepip: 7a. with the ‘--default-pip’ option. * ‘prompt’ – a String to be used after virtual environment is activated (defaults to ‘None’ which means directory name of the environment would be used). Changed in version 3.4: Added the ‘with_pip’ parameter New in version 3.6: Added the ‘prompt’ parameter Creators of third-party virtual environment tools will be free to use the provided *note EnvBuilder: 908. class as a base class. The returned env-builder is an object which has a method, ‘create’: -- Method: create (env_dir) Create a virtual environment by specifying the target directory (absolute or relative to the current directory) which is to contain the virtual environment. The ‘create’ method will either create the environment in the specified directory, or raise an appropriate exception. The ‘create’ method of the *note EnvBuilder: 908. class illustrates the hooks available for subclass customization: def create(self, env_dir): """ Create a virtualized Python environment in a directory. env_dir is the target directory to create an environment in. """ env_dir = os.path.abspath(env_dir) context = self.ensure_directories(env_dir) self.create_configuration(context) self.setup_python(context) self.setup_scripts(context) self.post_setup(context) Each of the methods *note ensure_directories(): 3327, *note create_configuration(): 3328, *note setup_python(): 3329, *note setup_scripts(): 332a. and *note post_setup(): 332b. can be overridden. -- Method: ensure_directories (env_dir) Creates the environment directory and all necessary directories, and returns a context object. This is just a holder for attributes (such as paths), for use by the other methods. The directories are allowed to exist already, as long as either ‘clear’ or ‘upgrade’ were specified to allow operating on an existing environment directory. -- Method: create_configuration (context) Creates the ‘pyvenv.cfg’ configuration file in the environment. -- Method: setup_python (context) Creates a copy or symlink to the Python executable in the environment. On POSIX systems, if a specific executable ‘python3.x’ was used, symlinks to ‘python’ and ‘python3’ will be created pointing to that executable, unless files with those names already exist. -- Method: setup_scripts (context) Installs activation scripts appropriate to the platform into the virtual environment. -- Method: post_setup (context) A placeholder method which can be overridden in third party implementations to pre-install packages in the virtual environment or perform other post-creation steps. Changed in version 3.7.2: Windows now uses redirector scripts for ‘python[w].exe’ instead of copying the actual binaries. In 3.7.2 only *note setup_python(): 3329. does nothing unless running from a build in the source tree. Changed in version 3.7.3: Windows copies the redirector scripts as part of *note setup_python(): 3329. instead of *note setup_scripts(): 332a. This was not the case in 3.7.2. When using symlinks, the original executables will be linked. In addition, *note EnvBuilder: 908. provides this utility method that can be called from *note setup_scripts(): 332a. or *note post_setup(): 332b. in subclasses to assist in installing custom scripts into the virtual environment. -- Method: install_scripts (context, path) `path' is the path to a directory that should contain subdirectories “common”, “posix”, “nt”, each containing scripts destined for the bin directory in the environment. The contents of “common” and the directory corresponding to *note os.name: 1bb0. are copied after some text replacement of placeholders: * ‘__VENV_DIR__’ is replaced with the absolute path of the environment directory. * ‘__VENV_NAME__’ is replaced with the environment name (final path segment of environment directory). * ‘__VENV_PROMPT__’ is replaced with the prompt (the environment name surrounded by parentheses and with a following space) * ‘__VENV_BIN_NAME__’ is replaced with the name of the bin directory (either ‘bin’ or ‘Scripts’). * ‘__VENV_PYTHON__’ is replaced with the absolute path of the environment’s executable. The directories are allowed to exist (for when an existing environment is being upgraded). There is also a module-level convenience function: -- Function: venv.create (env_dir, system_site_packages=False, clear=False, symlinks=False, with_pip=False, prompt=None) Create an *note EnvBuilder: 908. with the given keyword arguments, and call its *note create(): 3326. method with the `env_dir' argument. New in version 3.3. Changed in version 3.4: Added the ‘with_pip’ parameter Changed in version 3.6: Added the ‘prompt’ parameter  File: python.info, Node: An example of extending EnvBuilder, Prev: API<2>, Up: venv — Creation of virtual environments 5.28.3.3 An example of extending ‘EnvBuilder’ ............................................. The following script shows how to extend *note EnvBuilder: 908. by implementing a subclass which installs setuptools and pip into a created virtual environment: import os import os.path from subprocess import Popen, PIPE import sys from threading import Thread from urllib.parse import urlparse from urllib.request import urlretrieve import venv class ExtendedEnvBuilder(venv.EnvBuilder): """ This builder installs setuptools and pip so that you can pip or easy_install other packages into the created virtual environment. :param nodist: If true, setuptools and pip are not installed into the created virtual environment. :param nopip: If true, pip is not installed into the created virtual environment. :param progress: If setuptools or pip are installed, the progress of the installation can be monitored by passing a progress callable. If specified, it is called with two arguments: a string indicating some progress, and a context indicating where the string is coming from. The context argument can have one of three values: 'main', indicating that it is called from virtualize() itself, and 'stdout' and 'stderr', which are obtained by reading lines from the output streams of a subprocess which is used to install the app. If a callable is not specified, default progress information is output to sys.stderr. """ def __init__(self, *args, **kwargs): self.nodist = kwargs.pop('nodist', False) self.nopip = kwargs.pop('nopip', False) self.progress = kwargs.pop('progress', None) self.verbose = kwargs.pop('verbose', False) super().__init__(*args, **kwargs) def post_setup(self, context): """ Set up any packages which need to be pre-installed into the virtual environment being created. :param context: The information for the virtual environment creation request being processed. """ os.environ['VIRTUAL_ENV'] = context.env_dir if not self.nodist: self.install_setuptools(context) # Can't install pip without setuptools if not self.nopip and not self.nodist: self.install_pip(context) def reader(self, stream, context): """ Read lines from a subprocess' output stream and either pass to a progress callable (if specified) or write progress information to sys.stderr. """ progress = self.progress while True: s = stream.readline() if not s: break if progress is not None: progress(s, context) else: if not self.verbose: sys.stderr.write('.') else: sys.stderr.write(s.decode('utf-8')) sys.stderr.flush() stream.close() def install_script(self, context, name, url): _, _, path, _, _, _ = urlparse(url) fn = os.path.split(path)[-1] binpath = context.bin_path distpath = os.path.join(binpath, fn) # Download script into the virtual environment's binaries folder urlretrieve(url, distpath) progress = self.progress if self.verbose: term = '\n' else: term = '' if progress is not None: progress('Installing %s ...%s' % (name, term), 'main') else: sys.stderr.write('Installing %s ...%s' % (name, term)) sys.stderr.flush() # Install in the virtual environment args = [context.env_exe, fn] p = Popen(args, stdout=PIPE, stderr=PIPE, cwd=binpath) t1 = Thread(target=self.reader, args=(p.stdout, 'stdout')) t1.start() t2 = Thread(target=self.reader, args=(p.stderr, 'stderr')) t2.start() p.wait() t1.join() t2.join() if progress is not None: progress('done.', 'main') else: sys.stderr.write('done.\n') # Clean up - no longer needed os.unlink(distpath) def install_setuptools(self, context): """ Install setuptools in the virtual environment. :param context: The information for the virtual environment creation request being processed. """ url = 'https://bitbucket.org/pypa/setuptools/downloads/ez_setup.py' self.install_script(context, 'setuptools', url) # clear up the setuptools archive which gets downloaded pred = lambda o: o.startswith('setuptools-') and o.endswith('.tar.gz') files = filter(pred, os.listdir(context.bin_path)) for f in files: f = os.path.join(context.bin_path, f) os.unlink(f) def install_pip(self, context): """ Install pip in the virtual environment. :param context: The information for the virtual environment creation request being processed. """ url = 'https://bootstrap.pypa.io/get-pip.py' self.install_script(context, 'pip', url) def main(args=None): compatible = True if sys.version_info < (3, 3): compatible = False elif not hasattr(sys, 'base_prefix'): compatible = False if not compatible: raise ValueError('This script is only for use with ' 'Python 3.3 or later') else: import argparse parser = argparse.ArgumentParser(prog=__name__, description='Creates virtual Python ' 'environments in one or ' 'more target ' 'directories.') parser.add_argument('dirs', metavar='ENV_DIR', nargs='+', help='A directory in which to create the 'virtual environment.') parser.add_argument('--no-setuptools', default=False, action='store_true', dest='nodist', help="Don't install setuptools or pip in the " "virtual environment.") parser.add_argument('--no-pip', default=False, action='store_true', dest='nopip', help="Don't install pip in the virtual " "environment.") parser.add_argument('--system-site-packages', default=False, action='store_true', dest='system_site', help='Give the virtual environment access to the ' 'system site-packages dir.') if os.name == 'nt': use_symlinks = False else: use_symlinks = True parser.add_argument('--symlinks', default=use_symlinks, action='store_true', dest='symlinks', help='Try to use symlinks rather than copies, ' 'when symlinks are not the default for ' 'the platform.') parser.add_argument('--clear', default=False, action='store_true', dest='clear', help='Delete the contents of the ' 'virtual environment ' 'directory if it already ' 'exists, before virtual ' 'environment creation.') parser.add_argument('--upgrade', default=False, action='store_true', dest='upgrade', help='Upgrade the virtual ' 'environment directory to ' 'use this version of ' 'Python, assuming Python ' 'has been upgraded ' 'in-place.') parser.add_argument('--verbose', default=False, action='store_true', dest='verbose', help='Display the output ' 'from the scripts which ' 'install setuptools and pip.') options = parser.parse_args(args) if options.upgrade and options.clear: raise ValueError('you cannot supply --upgrade and --clear together.') builder = ExtendedEnvBuilder(system_site_packages=options.system_site, clear=options.clear, symlinks=options.symlinks, upgrade=options.upgrade, nodist=options.nodist, nopip=options.nopip, verbose=options.verbose) for d in options.dirs: builder.create(d) if __name__ == '__main__': rc = 1 try: main() rc = 0 except Exception as e: print('Error: %s' % e, file=sys.stderr) sys.exit(rc) This script is also available for download online(1). ---------- Footnotes ---------- (1) https://gist.github.com/vsajip/4673395  File: python.info, Node: zipapp — Manage executable Python zip archives, Prev: venv — Creation of virtual environments, Up: Software Packaging and Distribution 5.28.4 ‘zipapp’ — Manage executable Python zip archives ------------------------------------------------------- New in version 3.5. `Source code:' Lib/zipapp.py(1) __________________________________________________________________ This module provides tools to manage the creation of zip files containing Python code, which can be *note executed directly by the Python interpreter: fd0. The module provides both a *note Command-Line Interface: 3331. and a *note Python API: 3332. * Menu: * Basic Example:: * Command-Line Interface: Command-Line Interface<5>. * Python API:: * Examples: Examples<27>. * Specifying the Interpreter:: * Creating Standalone Applications with zipapp:: * The Python Zip Application Archive Format:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/zipapp.py  File: python.info, Node: Basic Example, Next: Command-Line Interface<5>, Up: zipapp — Manage executable Python zip archives 5.28.4.1 Basic Example ...................... The following example shows how the *note Command-Line Interface: 3331. can be used to create an executable archive from a directory containing Python code. When run, the archive will execute the ‘main’ function from the module ‘myapp’ in the archive. $ python -m zipapp myapp -m "myapp:main" $ python myapp.pyz <output from myapp>  File: python.info, Node: Command-Line Interface<5>, Next: Python API, Prev: Basic Example, Up: zipapp — Manage executable Python zip archives 5.28.4.2 Command-Line Interface ............................... When called as a program from the command line, the following form is used: $ python -m zipapp source [options] If `source' is a directory, this will create an archive from the contents of `source'. If `source' is a file, it should be an archive, and it will be copied to the target archive (or the contents of its shebang line will be displayed if the –info option is specified). The following options are understood: -- Program Option: -o <output>, --output=<output> Write the output to a file named `output'. If this option is not specified, the output filename will be the same as the input `source', with the extension ‘.pyz’ added. If an explicit filename is given, it is used as is (so a ‘.pyz’ extension should be included if required). An output filename must be specified if the `source' is an archive (and in that case, `output' must not be the same as `source'). -- Program Option: -p <interpreter>, --python=<interpreter> Add a ‘#!’ line to the archive specifying `interpreter' as the command to run. Also, on POSIX, make the archive executable. The default is to write no ‘#!’ line, and not make the file executable. -- Program Option: -m <mainfn>, --main=<mainfn> Write a ‘__main__.py’ file to the archive that executes `mainfn'. The `mainfn' argument should have the form “pkg.mod:fn”, where “pkg.mod” is a package/module in the archive, and “fn” is a callable in the given module. The ‘__main__.py’ file will execute that callable. *note –main: 3337. cannot be specified when copying an archive. -- Program Option: -c, --compress Compress files with the deflate method, reducing the size of the output file. By default, files are stored uncompressed in the archive. *note –compress: 3338. has no effect when copying an archive. New in version 3.7. -- Program Option: --info Display the interpreter embedded in the archive, for diagnostic purposes. In this case, any other options are ignored and SOURCE must be an archive, not a directory. -- Program Option: -h, --help Print a short usage message and exit.  File: python.info, Node: Python API, Next: Examples<27>, Prev: Command-Line Interface<5>, Up: zipapp — Manage executable Python zip archives 5.28.4.3 Python API ................... The module defines two convenience functions: -- Function: zipapp.create_archive (source, target=None, interpreter=None, main=None, filter=None, compressed=False) Create an application archive from `source'. The source can be any of the following: * The name of a directory, or a *note path-like object: 36a. referring to a directory, in which case a new application archive will be created from the content of that directory. * The name of an existing application archive file, or a *note path-like object: 36a. referring to such a file, in which case the file is copied to the target (modifying it to reflect the value given for the `interpreter' argument). The file name should include the ‘.pyz’ extension, if required. * A file object open for reading in bytes mode. The content of the file should be an application archive, and the file object is assumed to be positioned at the start of the archive. The `target' argument determines where the resulting archive will be written: * If it is the name of a file, or a *note path-like object: 36a, the archive will be written to that file. * If it is an open file object, the archive will be written to that file object, which must be open for writing in bytes mode. * If the target is omitted (or ‘None’), the source must be a directory and the target will be a file with the same name as the source, with a ‘.pyz’ extension added. The `interpreter' argument specifies the name of the Python interpreter with which the archive will be executed. It is written as a “shebang” line at the start of the archive. On POSIX, this will be interpreted by the OS, and on Windows it will be handled by the Python launcher. Omitting the `interpreter' results in no shebang line being written. If an interpreter is specified, and the target is a filename, the executable bit of the target file will be set. The `main' argument specifies the name of a callable which will be used as the main program for the archive. It can only be specified if the source is a directory, and the source does not already contain a ‘__main__.py’ file. The `main' argument should take the form “pkg.module:callable” and the archive will be run by importing “pkg.module” and executing the given callable with no arguments. It is an error to omit `main' if the source is a directory and does not contain a ‘__main__.py’ file, as otherwise the resulting archive would not be executable. The optional `filter' argument specifies a callback function that is passed a Path object representing the path to the file being added (relative to the source directory). It should return ‘True’ if the file is to be added. The optional `compressed' argument determines whether files are compressed. If set to ‘True’, files in the archive are compressed with the deflate method; otherwise, files are stored uncompressed. This argument has no effect when copying an existing archive. If a file object is specified for `source' or `target', it is the caller’s responsibility to close it after calling create_archive. When copying an existing archive, file objects supplied only need ‘read’ and ‘readline’, or ‘write’ methods. When creating an archive from a directory, if the target is a file object it will be passed to the ‘zipfile.ZipFile’ class, and must supply the methods needed by that class. New in version 3.7: Added the `filter' and `compressed' arguments. -- Function: zipapp.get_interpreter (archive) Return the interpreter specified in the ‘#!’ line at the start of the archive. If there is no ‘#!’ line, return *note None: 157. The `archive' argument can be a filename or a file-like object open for reading in bytes mode. It is assumed to be at the start of the archive.  File: python.info, Node: Examples<27>, Next: Specifying the Interpreter, Prev: Python API, Up: zipapp — Manage executable Python zip archives 5.28.4.4 Examples ................. Pack up a directory into an archive, and run it. $ python -m zipapp myapp $ python myapp.pyz <output from myapp> The same can be done using the *note create_archive(): 41d. function: >>> import zipapp >>> zipapp.create_archive('myapp', 'myapp.pyz') To make the application directly executable on POSIX, specify an interpreter to use. $ python -m zipapp myapp -p "/usr/bin/env python" $ ./myapp.pyz <output from myapp> To replace the shebang line on an existing archive, create a modified archive using the *note create_archive(): 41d. function: >>> import zipapp >>> zipapp.create_archive('old_archive.pyz', 'new_archive.pyz', '/usr/bin/python3') To update the file in place, do the replacement in memory using a ‘BytesIO’ object, and then overwrite the source afterwards. Note that there is a risk when overwriting a file in place that an error will result in the loss of the original file. This code does not protect against such errors, but production code should do so. Also, this method will only work if the archive fits in memory: >>> import zipapp >>> import io >>> temp = io.BytesIO() >>> zipapp.create_archive('myapp.pyz', temp, '/usr/bin/python2') >>> with open('myapp.pyz', 'wb') as f: >>> f.write(temp.getvalue())  File: python.info, Node: Specifying the Interpreter, Next: Creating Standalone Applications with zipapp, Prev: Examples<27>, Up: zipapp — Manage executable Python zip archives 5.28.4.5 Specifying the Interpreter ................................... Note that if you specify an interpreter and then distribute your application archive, you need to ensure that the interpreter used is portable. The Python launcher for Windows supports most common forms of POSIX ‘#!’ line, but there are other issues to consider: * If you use “/usr/bin/env python” (or other forms of the “python” command, such as “/usr/bin/python”), you need to consider that your users may have either Python 2 or Python 3 as their default, and write your code to work under both versions. * If you use an explicit version, for example “/usr/bin/env python3” your application will not work for users who do not have that version. (This may be what you want if you have not made your code Python 2 compatible). * There is no way to say “python X.Y or later”, so be careful of using an exact version like “/usr/bin/env python3.4” as you will need to change your shebang line for users of Python 3.5, for example. Typically, you should use an “/usr/bin/env python2” or “/usr/bin/env python3”, depending on whether your code is written for Python 2 or 3.  File: python.info, Node: Creating Standalone Applications with zipapp, Next: The Python Zip Application Archive Format, Prev: Specifying the Interpreter, Up: zipapp — Manage executable Python zip archives 5.28.4.6 Creating Standalone Applications with zipapp ..................................................... Using the *note zipapp: 141. module, it is possible to create self-contained Python programs, which can be distributed to end users who only need to have a suitable version of Python installed on their system. The key to doing this is to bundle all of the application’s dependencies into the archive, along with the application code. The steps to create a standalone archive are as follows: 1. Create your application in a directory as normal, so you have a ‘myapp’ directory containing a ‘__main__.py’ file, and any supporting application code. 2. Install all of your application’s dependencies into the ‘myapp’ directory, using pip: $ python -m pip install -r requirements.txt --target myapp (this assumes you have your project requirements in a ‘requirements.txt’ file - if not, you can just list the dependencies manually on the pip command line). 3. Optionally, delete the ‘.dist-info’ directories created by pip in the ‘myapp’ directory. These hold metadata for pip to manage the packages, and as you won’t be making any further use of pip they aren’t required - although it won’t do any harm if you leave them. 4. Package the application using: $ python -m zipapp -p "interpreter" myapp This will produce a standalone executable, which can be run on any machine with the appropriate interpreter available. See *note Specifying the Interpreter: 3340. for details. It can be shipped to users as a single file. On Unix, the ‘myapp.pyz’ file is executable as it stands. You can rename the file to remove the ‘.pyz’ extension if you prefer a “plain” command name. On Windows, the ‘myapp.pyz[w]’ file is executable by virtue of the fact that the Python interpreter registers the ‘.pyz’ and ‘.pyzw’ file extensions when installed. * Menu: * Making a Windows executable:: * Caveats::  File: python.info, Node: Making a Windows executable, Next: Caveats, Up: Creating Standalone Applications with zipapp 5.28.4.7 Making a Windows executable .................................... On Windows, registration of the ‘.pyz’ extension is optional, and furthermore, there are certain places that don’t recognise registered extensions “transparently” (the simplest example is that ‘subprocess.run(['myapp'])’ won’t find your application - you need to explicitly specify the extension). On Windows, therefore, it is often preferable to create an executable from the zipapp. This is relatively easy, although it does require a C compiler. The basic approach relies on the fact that zipfiles can have arbitrary data prepended, and Windows exe files can have arbitrary data appended. So by creating a suitable launcher and tacking the ‘.pyz’ file onto the end of it, you end up with a single-file executable that runs your application. A suitable launcher can be as simple as the following: #define Py_LIMITED_API 1 #include "Python.h" #define WIN32_LEAN_AND_MEAN #include <windows.h> #ifdef WINDOWS int WINAPI wWinMain( HINSTANCE hInstance, /* handle to current instance */ HINSTANCE hPrevInstance, /* handle to previous instance */ LPWSTR lpCmdLine, /* pointer to command line */ int nCmdShow /* show state of window */ ) #else int wmain() #endif { wchar_t **myargv = _alloca((__argc + 1) * sizeof(wchar_t*)); myargv[0] = __wargv[0]; memcpy(myargv + 1, __wargv, __argc * sizeof(wchar_t *)); return Py_Main(__argc+1, myargv); } If you define the ‘WINDOWS’ preprocessor symbol, this will generate a GUI executable, and without it, a console executable. To compile the executable, you can either just use the standard MSVC command line tools, or you can take advantage of the fact that distutils knows how to compile Python source: >>> from distutils.ccompiler import new_compiler >>> import distutils.sysconfig >>> import sys >>> import os >>> from pathlib import Path >>> def compile(src): >>> src = Path(src) >>> cc = new_compiler() >>> exe = src.stem >>> cc.add_include_dir(distutils.sysconfig.get_python_inc()) >>> cc.add_library_dir(os.path.join(sys.base_exec_prefix, 'libs')) >>> # First the CLI executable >>> objs = cc.compile([str(src)]) >>> cc.link_executable(objs, exe) >>> # Now the GUI executable >>> cc.define_macro('WINDOWS') >>> objs = cc.compile([str(src)]) >>> cc.link_executable(objs, exe + 'w') >>> if __name__ == "__main__": >>> compile("zastub.c") The resulting launcher uses the “Limited ABI”, so it will run unchanged with any version of Python 3.x. All it needs is for Python (‘python3.dll’) to be on the user’s ‘PATH’. For a fully standalone distribution, you can distribute the launcher with your application appended, bundled with the Python “embedded” distribution. This will run on any PC with the appropriate architecture (32 bit or 64 bit).  File: python.info, Node: Caveats, Prev: Making a Windows executable, Up: Creating Standalone Applications with zipapp 5.28.4.8 Caveats ................ There are some limitations to the process of bundling your application into a single file. In most, if not all, cases they can be addressed without needing major changes to your application. 1. If your application depends on a package that includes a C extension, that package cannot be run from a zip file (this is an OS limitation, as executable code must be present in the filesystem for the OS loader to load it). In this case, you can exclude that dependency from the zipfile, and either require your users to have it installed, or ship it alongside your zipfile and add code to your ‘__main__.py’ to include the directory containing the unzipped module in ‘sys.path’. In this case, you will need to make sure to ship appropriate binaries for your target architecture(s) (and potentially pick the correct version to add to ‘sys.path’ at runtime, based on the user’s machine). 2. If you are shipping a Windows executable as described above, you either need to ensure that your users have ‘python3.dll’ on their PATH (which is not the default behaviour of the installer) or you should bundle your application with the embedded distribution. 3. The suggested launcher above uses the Python embedding API. This means that in your application, ‘sys.executable’ will be your application, and `not' a conventional Python interpreter. Your code and its dependencies need to be prepared for this possibility. For example, if your application uses the *note multiprocessing: b7. module, it will need to call *note multiprocessing.set_executable(): 20b7. to let the module know where to find the standard Python interpreter.  File: python.info, Node: The Python Zip Application Archive Format, Prev: Creating Standalone Applications with zipapp, Up: zipapp — Manage executable Python zip archives 5.28.4.9 The Python Zip Application Archive Format .................................................. Python has been able to execute zip files which contain a ‘__main__.py’ file since version 2.6. In order to be executed by Python, an application archive simply has to be a standard zip file containing a ‘__main__.py’ file which will be run as the entry point for the application. As usual for any Python script, the parent of the script (in this case the zip file) will be placed on *note sys.path: 488. and thus further modules can be imported from the zip file. The zip file format allows arbitrary data to be prepended to a zip file. The zip application format uses this ability to prepend a standard POSIX “shebang” line to the file (‘#!/path/to/interpreter’). Formally, the Python zip application format is therefore: 1. An optional shebang line, containing the characters ‘b'#!'’ followed by an interpreter name, and then a newline (‘b'\n'’) character. The interpreter name can be anything acceptable to the OS “shebang” processing, or the Python launcher on Windows. The interpreter should be encoded in UTF-8 on Windows, and in *note sys.getfilesystemencoding(): 4f6. on POSIX. 2. Standard zipfile data, as generated by the *note zipfile: 142. module. The zipfile content `must' include a file called ‘__main__.py’ (which must be in the “root” of the zipfile - i.e., it cannot be in a subdirectory). The zipfile data can be compressed or uncompressed. If an application archive has a shebang line, it may have the executable bit set on POSIX systems, to allow it to be executed directly. There is no requirement that the tools in this module are used to create application archives - the module is a convenience, but archives in the above format created by any means are acceptable to Python.  File: python.info, Node: Python Runtime Services, Next: Custom Python Interpreters, Prev: Software Packaging and Distribution, Up: The Python Standard Library 5.29 Python Runtime Services ============================ The modules described in this chapter provide a wide range of services related to the Python interpreter and its interaction with its environment. Here’s an overview: * Menu: * sys — System-specific parameters and functions:: * sysconfig — Provide access to Python’s configuration information:: * builtins — Built-in objects:: * __main__ — Top-level script environment:: * warnings — Warning control:: * dataclasses — Data Classes:: * contextlib — Utilities for with-statement contexts:: * abc — Abstract Base Classes:: * atexit — Exit handlers:: * traceback — Print or retrieve a stack traceback:: * __future__ — Future statement definitions:: * gc — Garbage Collector interface:: * inspect — Inspect live objects:: * site — Site-specific configuration hook::  File: python.info, Node: sys — System-specific parameters and functions, Next: sysconfig — Provide access to Python’s configuration information, Up: Python Runtime Services 5.29.1 ‘sys’ — System-specific parameters and functions ------------------------------------------------------- __________________________________________________________________ This module provides access to some variables used or maintained by the interpreter and to functions that interact strongly with the interpreter. It is always available. -- Data: sys.abiflags On POSIX systems where Python was built with the standard ‘configure’ script, this contains the ABI flags as specified by PEP 3149(1). Changed in version 3.8: Default flags became an empty string (‘m’ flag for pymalloc has been removed). New in version 3.2. -- Function: sys.addaudithook (hook) Append the callable `hook' to the list of active auditing hooks for the current interpreter. When an auditing event is raised through the *note sys.audit(): 31ea. function, each hook will be called in the order it was added with the event name and the tuple of arguments. Native hooks added by *note PySys_AddAuditHook(): 31ed. are called first, followed by hooks added in the current interpreter. Hooks can then log the event, raise an exception to abort the operation, or terminate the process entirely. Calling *note sys.addaudithook(): 31ec. will itself raise an auditing event named ‘sys.addaudithook’ with no arguments. If any existing hooks raise an exception derived from *note RuntimeError: 2ba, the new hook will not be added and the exception suppressed. As a result, callers cannot assume that their hook has been added unless they control all existing hooks. See the *note audit events table: 31e7. for all events raised by CPython, and PEP 578(2) for the original design discussion. New in version 3.8. Changed in version 3.8.1: Exceptions derived from *note Exception: 1a9. but not *note RuntimeError: 2ba. are no longer suppressed. `CPython implementation detail:' When tracing is enabled (see *note settrace(): e3e.), Python hooks are only traced if the callable has a ‘__cantrace__’ member that is set to a true value. Otherwise, trace functions will skip the hook. -- Data: sys.argv The list of command line arguments passed to a Python script. ‘argv[0]’ is the script name (it is operating system dependent whether this is a full pathname or not). If the command was executed using the *note -c: e9e. command line option to the interpreter, ‘argv[0]’ is set to the string ‘'-c'’. If no script name was passed to the Python interpreter, ‘argv[0]’ is the empty string. To loop over the standard input, or the list of files given on the command line, see the *note fileinput: 80. module. Note: On Unix, command line arguments are passed by bytes from OS. Python decodes them with filesystem encoding and “surrogateescape” error handler. When you need original bytes, you can get it by ‘[os.fsencode(arg) for arg in sys.argv]’. -- Function: sys.audit (event, *args) Raise an auditing event and trigger any active auditing hooks. `event' is a string identifying the event, and `args' may contain optional arguments with more information about the event. The number and types of arguments for a given event are considered a public and stable API and should not be modified between releases. For example, one auditing event is named ‘os.chdir’. This event has one argument called `path' that will contain the requested new working directory. *note sys.audit(): 31ea. will call the existing auditing hooks, passing the event name and arguments, and will re-raise the first exception from any hook. In general, if an exception is raised, it should not be handled and the process should be terminated as quickly as possible. This allows hook implementations to decide how to respond to particular events: they can merely log the event or abort the operation by raising an exception. Hooks are added using the *note sys.addaudithook(): 31ec. or *note PySys_AddAuditHook(): 31ed. functions. The native equivalent of this function is *note PySys_Audit(): 31eb. Using the native function is preferred when possible. See the *note audit events table: 31e7. for all events raised by CPython. New in version 3.8. -- Data: sys.base_exec_prefix Set during Python startup, before ‘site.py’ is run, to the same value as *note exec_prefix: 3323. If not running in a *note virtual environment: 3321, the values will stay the same; if ‘site.py’ finds that a virtual environment is in use, the values of *note prefix: 3322. and *note exec_prefix: 3323. will be changed to point to the virtual environment, whereas *note base_prefix: 2d50. and *note base_exec_prefix: 3324. will remain pointing to the base Python installation (the one which the virtual environment was created from). New in version 3.3. -- Data: sys.base_prefix Set during Python startup, before ‘site.py’ is run, to the same value as *note prefix: 3322. If not running in a *note virtual environment: 3321, the values will stay the same; if ‘site.py’ finds that a virtual environment is in use, the values of *note prefix: 3322. and *note exec_prefix: 3323. will be changed to point to the virtual environment, whereas *note base_prefix: 2d50. and *note base_exec_prefix: 3324. will remain pointing to the base Python installation (the one which the virtual environment was created from). New in version 3.3. -- Data: sys.byteorder An indicator of the native byte order. This will have the value ‘'big'’ on big-endian (most-significant byte first) platforms, and ‘'little'’ on little-endian (least-significant byte first) platforms. -- Data: sys.builtin_module_names A tuple of strings giving the names of all modules that are compiled into this Python interpreter. (This information is not available in any other way — ‘modules.keys()’ only lists the imported modules.) -- Function: sys.call_tracing (func, args) Call ‘func(*args)’, while tracing is enabled. The tracing state is saved, and restored afterwards. This is intended to be called from a debugger from a checkpoint, to recursively debug some other code. -- Data: sys.copyright A string containing the copyright pertaining to the Python interpreter. -- Function: sys._clear_type_cache () Clear the internal type cache. The type cache is used to speed up attribute and method lookups. Use the function `only' to drop unnecessary references during reference leak debugging. This function should be used for internal and specialized purposes only. -- Function: sys._current_frames () Return a dictionary mapping each thread’s identifier to the topmost stack frame currently active in that thread at the time the function is called. Note that functions in the *note traceback: 113. module can build the call stack given such a frame. This is most useful for debugging deadlock: this function does not require the deadlocked threads’ cooperation, and such threads’ call stacks are frozen for as long as they remain deadlocked. The frame returned for a non-deadlocked thread may bear no relationship to that thread’s current activity by the time calling code examines the frame. This function should be used for internal and specialized purposes only. Raises an *note auditing event: fd1. ‘sys._current_frames’ with no arguments. -- Function: sys.breakpointhook () This hook function is called by built-in *note breakpoint(): 2f9. By default, it drops you into the *note pdb: c9. debugger, but it can be set to any other function so that you can choose which debugger gets used. The signature of this function is dependent on what it calls. For example, the default binding (e.g. ‘pdb.set_trace()’) expects no arguments, but you might bind it to a function that expects additional arguments (positional and/or keyword). The built-in ‘breakpoint()’ function passes its ‘*args’ and ‘**kws’ straight through. Whatever ‘breakpointhooks()’ returns is returned from ‘breakpoint()’. The default implementation first consults the environment variable *note PYTHONBREAKPOINT: 314. If that is set to ‘"0"’ then this function returns immediately; i.e. it is a no-op. If the environment variable is not set, or is set to the empty string, ‘pdb.set_trace()’ is called. Otherwise this variable should name a function to run, using Python’s dotted-import nomenclature, e.g. ‘package.subpackage.module.function’. In this case, ‘package.subpackage.module’ would be imported and the resulting module must have a callable named ‘function()’. This is run, passing in ‘*args’ and ‘**kws’, and whatever ‘function()’ returns, ‘sys.breakpointhook()’ returns to the built-in *note breakpoint(): 2f9. function. Note that if anything goes wrong while importing the callable named by *note PYTHONBREAKPOINT: 314, a *note RuntimeWarning: 2c0. is reported and the breakpoint is ignored. Also note that if ‘sys.breakpointhook()’ is overridden programmatically, *note PYTHONBREAKPOINT: 314. is `not' consulted. New in version 3.7. -- Function: sys._debugmallocstats () Print low-level information to stderr about the state of CPython’s memory allocator. If Python is configured –with-pydebug, it also performs some expensive internal consistency checks. New in version 3.3. `CPython implementation detail:' This function is specific to CPython. The exact output format is not defined here, and may change. -- Data: sys.dllhandle Integer specifying the handle of the Python DLL. *note Availability: ffb.: Windows. -- Function: sys.displayhook (value) If `value' is not ‘None’, this function prints ‘repr(value)’ to ‘sys.stdout’, and saves `value' in ‘builtins._’. If ‘repr(value)’ is not encodable to ‘sys.stdout.encoding’ with ‘sys.stdout.errors’ error handler (which is probably ‘'strict'’), encode it to ‘sys.stdout.encoding’ with ‘'backslashreplace'’ error handler. ‘sys.displayhook’ is called on the result of evaluating an *note expression: 3350. entered in an interactive Python session. The display of these values can be customized by assigning another one-argument function to ‘sys.displayhook’. Pseudo-code: def displayhook(value): if value is None: return # Set '_' to None to avoid recursion builtins._ = None text = repr(value) try: sys.stdout.write(text) except UnicodeEncodeError: bytes = text.encode(sys.stdout.encoding, 'backslashreplace') if hasattr(sys.stdout, 'buffer'): sys.stdout.buffer.write(bytes) else: text = bytes.decode(sys.stdout.encoding, 'strict') sys.stdout.write(text) sys.stdout.write("\n") builtins._ = value Changed in version 3.2: Use ‘'backslashreplace'’ error handler on *note UnicodeEncodeError: 1fc. -- Data: sys.dont_write_bytecode If this is true, Python won’t try to write ‘.pyc’ files on the import of source modules. This value is initially set to ‘True’ or ‘False’ depending on the *note -B: d38. command line option and the *note PYTHONDONTWRITEBYTECODE: d39. environment variable, but you can set it yourself to control bytecode file generation. -- Data: sys.pycache_prefix If this is set (not ‘None’), Python will write bytecode-cache ‘.pyc’ files to (and read them from) a parallel directory tree rooted at this directory, rather than from ‘__pycache__’ directories in the source code tree. Any ‘__pycache__’ directories in the source code tree will be ignored and new ‘.pyc’ files written within the pycache prefix. Thus if you use *note compileall: 21. as a pre-build step, you must ensure you run it with the same pycache prefix (if any) that you will use at runtime. A relative path is interpreted relative to the current working directory. This value is initially set based on the value of the *note -X: 155. ‘pycache_prefix=PATH’ command-line option or the *note PYTHONPYCACHEPREFIX: 154. environment variable (command-line takes precedence). If neither are set, it is ‘None’. New in version 3.8. -- Function: sys.excepthook (type, value, traceback) This function prints out a given traceback and exception to ‘sys.stderr’. When an exception is raised and uncaught, the interpreter calls ‘sys.excepthook’ with three arguments, the exception class, exception instance, and a traceback object. In an interactive session this happens just before control is returned to the prompt; in a Python program this happens just before the program exits. The handling of such top-level exceptions can be customized by assigning another three-argument function to ‘sys.excepthook’. Raise an auditing event ‘sys.excepthook’ with arguments ‘hook’, ‘type’, ‘value’, ‘traceback’ when an uncaught exception occurs. If no hook has been set, ‘hook’ may be ‘None’. If any hook raises an exception derived from *note RuntimeError: 2ba. the call to the hook will be suppressed. Otherwise, the audit hook exception will be reported as unraisable and ‘sys.excepthook’ will be called. See also ........ The *note sys.unraisablehook(): 22d. function handles unraisable exceptions and the *note threading.excepthook(): 231. function handles exception raised by *note threading.Thread.run(): 232. -- Data: sys.__breakpointhook__ -- Data: sys.__displayhook__ -- Data: sys.__excepthook__ -- Data: sys.__unraisablehook__ These objects contain the original values of ‘breakpointhook’, ‘displayhook’, ‘excepthook’, and ‘unraisablehook’ at the start of the program. They are saved so that ‘breakpointhook’, ‘displayhook’ and ‘excepthook’, ‘unraisablehook’ can be restored in case they happen to get replaced with broken or alternative objects. New in version 3.7: __breakpointhook__ New in version 3.8: __unraisablehook__ -- Function: sys.exc_info () This function returns a tuple of three values that give information about the exception that is currently being handled. The information returned is specific both to the current thread and to the current stack frame. If the current stack frame is not handling an exception, the information is taken from the calling stack frame, or its caller, and so on until a stack frame is found that is handling an exception. Here, “handling an exception” is defined as “executing an except clause.” For any stack frame, only information about the exception being currently handled is accessible. If no exception is being handled anywhere on the stack, a tuple containing three ‘None’ values is returned. Otherwise, the values returned are ‘(type, value, traceback)’. Their meaning is: `type' gets the type of the exception being handled (a subclass of *note BaseException: 1a8.); `value' gets the exception instance (an instance of the exception type); `traceback' gets a *note traceback object: 336. which encapsulates the call stack at the point where the exception originally occurred. -- Data: sys.exec_prefix A string giving the site-specific directory prefix where the platform-dependent Python files are installed; by default, this is also ‘'/usr/local'’. This can be set at build time with the ‘--exec-prefix’ argument to the ‘configure’ script. Specifically, all configuration files (e.g. the ‘pyconfig.h’ header file) are installed in the directory ‘`exec_prefix'/lib/python`X.Y'/config’, and shared library modules are installed in ‘`exec_prefix'/lib/python`X.Y'/lib-dynload’, where `X.Y' is the version number of Python, for example ‘3.2’. Note: If a *note virtual environment: 3321. is in effect, this value will be changed in ‘site.py’ to point to the virtual environment. The value for the Python installation will still be available, via *note base_exec_prefix: 3324. -- Data: sys.executable A string giving the absolute path of the executable binary for the Python interpreter, on systems where this makes sense. If Python is unable to retrieve the real path to its executable, *note sys.executable: 274. will be an empty string or ‘None’. -- Function: sys.exit ([arg]) Exit from Python. This is implemented by raising the *note SystemExit: 5fc. exception, so cleanup actions specified by finally clauses of *note try: d72. statements are honored, and it is possible to intercept the exit attempt at an outer level. The optional argument `arg' can be an integer giving the exit status (defaulting to zero), or another type of object. If it is an integer, zero is considered “successful termination” and any nonzero value is considered “abnormal termination” by shells and the like. Most systems require it to be in the range 0–127, and produce undefined results otherwise. Some systems have a convention for assigning specific meanings to specific exit codes, but these are generally underdeveloped; Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors. If another type of object is passed, ‘None’ is equivalent to passing zero, and any other object is printed to *note stderr: 30f. and results in an exit code of 1. In particular, ‘sys.exit("some error message")’ is a quick way to exit a program when an error occurs. Since *note exit(): 12b9. ultimately “only” raises an exception, it will only exit the process when called from the main thread, and the exception is not intercepted. Changed in version 3.6: If an error occurs in the cleanup after the Python interpreter has caught *note SystemExit: 5fc. (such as an error flushing buffered data in the standard streams), the exit status is changed to 120. -- Data: sys.flags The *note named tuple: aa3. `flags' exposes the status of command line flags. The attributes are read only. attribute flag -------------------------------------------------------------------- ‘debug’ *note -d: fda. *note inspect: a0. *note -i: e1f. ‘interactive’ *note -i: e1f. ‘isolated’ *note -I: fd2. ‘optimize’ *note -O: 68b. or *note -OO: 68c. *note dont_write_bytecode: 3351. *note -B: d38. ‘no_user_site’ *note -s: d15. ‘no_site’ *note -S: b24. ‘ignore_environment’ *note -E: fdc. ‘verbose’ *note -v: d88. ‘bytes_warning’ *note -b: 415. ‘quiet’ *note -q: fdf. ‘hash_randomization’ *note -R: fe0. ‘dev_mode’ *note -X: 155. ‘dev’ ‘utf8_mode’ *note -X: 155. ‘utf8’ Changed in version 3.2: Added ‘quiet’ attribute for the new *note -q: fdf. flag. New in version 3.2.3: The ‘hash_randomization’ attribute. Changed in version 3.3: Removed obsolete ‘division_warning’ attribute. Changed in version 3.4: Added ‘isolated’ attribute for *note -I: fd2. ‘isolated’ flag. Changed in version 3.7: Added ‘dev_mode’ attribute for the new *note -X: 155. ‘dev’ flag and ‘utf8_mode’ attribute for the new *note -X: 155. ‘utf8’ flag. -- Data: sys.float_info A *note named tuple: aa3. holding information about the float type. It contains low level information about the precision and internal representation. The values correspond to the various floating-point constants defined in the standard header file ‘float.h’ for the ‘C’ programming language; see section 5.2.4.2.2 of the 1999 ISO/IEC C standard *note [C99]: 3356, ‘Characteristics of floating types’, for details. attribute float.h macro explanation ------------------------------------------------------------------------------------------------------ ‘epsilon’ DBL_EPSILON difference between 1.0 and the least value greater than 1.0 that is representable as a float ‘dig’ DBL_DIG maximum number of decimal digits that can be faithfully represented in a float; see below ‘mant_dig’ DBL_MANT_DIG float precision: the number of base-‘radix’ digits in the significand of a float *note max: 80a. DBL_MAX maximum representable positive finite float ‘max_exp’ DBL_MAX_EXP maximum integer `e' such that ‘radix**(e-1)’ is a representable finite float ‘max_10_exp’ DBL_MAX_10_EXP maximum integer `e' such that ‘10**e’ is in the range of representable finite floats *note min: 809. DBL_MIN minimum representable positive `normalized' float ‘min_exp’ DBL_MIN_EXP minimum integer `e' such that ‘radix**(e-1)’ is a normalized float ‘min_10_exp’ DBL_MIN_10_EXP minimum integer `e' such that ‘10**e’ is a normalized float ‘radix’ FLT_RADIX radix of exponent representation ‘rounds’ FLT_ROUNDS integer constant representing the rounding mode used for arithmetic operations. This reflects the value of the system FLT_ROUNDS macro at interpreter startup time. See section 5.2.4.2.2 of the C99 standard for an explanation of the possible values and their meanings. The attribute ‘sys.float_info.dig’ needs further explanation. If ‘s’ is any string representing a decimal number with at most ‘sys.float_info.dig’ significant digits, then converting ‘s’ to a float and back again will recover a string representing the same decimal value: >>> import sys >>> sys.float_info.dig 15 >>> s = '3.14159265358979' # decimal string with 15 significant digits >>> format(float(s), '.15g') # convert to float and back -> same value '3.14159265358979' But for strings with more than ‘sys.float_info.dig’ significant digits, this isn’t always true: >>> s = '9876543211234567' # 16 significant digits is too many! >>> format(float(s), '.16g') # conversion changes value '9876543211234568' -- Data: sys.float_repr_style A string indicating how the *note repr(): 7cc. function behaves for floats. If the string has value ‘'short'’ then for a finite float ‘x’, ‘repr(x)’ aims to produce a short string with the property that ‘float(repr(x)) == x’. This is the usual behaviour in Python 3.1 and later. Otherwise, ‘float_repr_style’ has value ‘'legacy'’ and ‘repr(x)’ behaves in the same way as it did in versions of Python prior to 3.1. New in version 3.1. -- Function: sys.getallocatedblocks () Return the number of memory blocks currently allocated by the interpreter, regardless of their size. This function is mainly useful for tracking and debugging memory leaks. Because of the interpreter’s internal caches, the result can vary from call to call; you may have to call *note _clear_type_cache(): 334d. and *note gc.collect(): 22e. to get more predictable results. If a Python build or implementation cannot reasonably compute this information, *note getallocatedblocks(): 8e2. is allowed to return 0 instead. New in version 3.4. -- Function: sys.getandroidapilevel () Return the build time API version of Android as an integer. *note Availability: ffb.: Android. New in version 3.7. -- Function: sys.getcheckinterval () Return the interpreter’s “check interval”; see *note setcheckinterval(): 3357. Deprecated since version 3.2: Use *note getswitchinterval(): 3358. instead. -- Function: sys.getdefaultencoding () Return the name of the current default string encoding used by the Unicode implementation. -- Function: sys.getdlopenflags () Return the current value of the flags that are used for ‘dlopen()’ calls. Symbolic names for the flag values can be found in the *note os: c4. module (‘RTLD_xxx’ constants, e.g. *note os.RTLD_LAZY: a5f.). *note Availability: ffb.: Unix. -- Function: sys.getfilesystemencoding () Return the name of the encoding used to convert between Unicode filenames and bytes filenames. For best compatibility, str should be used for filenames in all cases, although representing filenames as bytes is also supported. Functions accepting or returning filenames should support either str or bytes and internally convert to the system’s preferred representation. This encoding is always ASCII-compatible. *note os.fsencode(): 4ef. and *note os.fsdecode(): 4ee. should be used to ensure that the correct encoding and errors mode are used. * In the UTF-8 mode, the encoding is ‘utf-8’ on any platform. * On macOS, the encoding is ‘'utf-8'’. * On Unix, the encoding is the locale encoding. * On Windows, the encoding may be ‘'utf-8'’ or ‘'mbcs'’, depending on user configuration. * On Android, the encoding is ‘'utf-8'’. * On VxWorks, the encoding is ‘'utf-8'’. Changed in version 3.2: *note getfilesystemencoding(): 4f6. result cannot be ‘None’ anymore. Changed in version 3.6: Windows is no longer guaranteed to return ‘'mbcs'’. See PEP 529(3) and *note _enablelegacywindowsfsencoding(): 4f8. for more information. Changed in version 3.7: Return ‘utf-8’ in the UTF-8 mode. -- Function: sys.getfilesystemencodeerrors () Return the name of the error mode used to convert between Unicode filenames and bytes filenames. The encoding name is returned from *note getfilesystemencoding(): 4f6. *note os.fsencode(): 4ef. and *note os.fsdecode(): 4ee. should be used to ensure that the correct encoding and errors mode are used. New in version 3.6. -- Function: sys.getrefcount (object) Return the reference count of the `object'. The count returned is generally one higher than you might expect, because it includes the (temporary) reference as an argument to *note getrefcount(): 335a. -- Function: sys.getrecursionlimit () Return the current value of the recursion limit, the maximum depth of the Python interpreter stack. This limit prevents infinite recursion from causing an overflow of the C stack and crashing Python. It can be set by *note setrecursionlimit(): e7b. -- Function: sys.getsizeof (object[, default]) Return the size of an object in bytes. The object can be any type of object. All built-in objects will return correct results, but this does not have to hold true for third-party extensions as it is implementation specific. Only the memory consumption directly attributed to the object is accounted for, not the memory consumption of objects it refers to. If given, `default' will be returned if the object does not provide means to retrieve the size. Otherwise a *note TypeError: 192. will be raised. *note getsizeof(): 32e8. calls the object’s ‘__sizeof__’ method and adds an additional garbage collector overhead if the object is managed by the garbage collector. See recursive sizeof recipe(4) for an example of using *note getsizeof(): 32e8. recursively to find the size of containers and all their contents. -- Function: sys.getswitchinterval () Return the interpreter’s “thread switch interval”; see *note setswitchinterval(): beb. New in version 3.2. -- Function: sys._getframe ([depth]) Return a frame object from the call stack. If optional integer `depth' is given, return the frame object that many calls below the top of the stack. If that is deeper than the call stack, *note ValueError: 1fb. is raised. The default for `depth' is zero, returning the frame at the top of the call stack. Raises an *note auditing event: fd1. ‘sys._getframe’ with no arguments. `CPython implementation detail:' This function should be used for internal and specialized purposes only. It is not guaranteed to exist in all implementations of Python. -- Function: sys.getprofile () Get the profiler function as set by *note setprofile(): e3d. -- Function: sys.gettrace () Get the trace function as set by *note settrace(): e3e. `CPython implementation detail:' The *note gettrace(): d48. function is intended only for implementing debuggers, profilers, coverage tools and the like. Its behavior is part of the implementation platform, rather than part of the language definition, and thus may not be available in all Python implementations. -- Function: sys.getwindowsversion () Return a named tuple describing the Windows version currently running. The named elements are `major', `minor', `build', `platform', `service_pack', `service_pack_minor', `service_pack_major', `suite_mask', `product_type' and `platform_version'. `service_pack' contains a string, `platform_version' a 3-tuple and all other values are integers. The components can also be accessed by name, so ‘sys.getwindowsversion()[0]’ is equivalent to ‘sys.getwindowsversion().major’. For compatibility with prior versions, only the first 5 elements are retrievable by indexing. `platform' will be ‘2 (VER_PLATFORM_WIN32_NT)’. `product_type' may be one of the following values: Constant Meaning ---------------------------------------------------------------------------------- ‘1 (VER_NT_WORKSTATION)’ The system is a workstation. ‘2 (VER_NT_DOMAIN_CONTROLLER)’ The system is a domain controller. ‘3 (VER_NT_SERVER)’ The system is a server, but not a domain controller. This function wraps the Win32 ‘GetVersionEx()’ function; see the Microsoft documentation on ‘OSVERSIONINFOEX()’ for more information about these fields. `platform_version' returns the accurate major version, minor version and build number of the current operating system, rather than the version that is being emulated for the process. It is intended for use in logging rather than for feature detection. *note Availability: ffb.: Windows. Changed in version 3.2: Changed to a named tuple and added `service_pack_minor', `service_pack_major', `suite_mask', and `product_type'. Changed in version 3.6: Added `platform_version' -- Function: sys.get_asyncgen_hooks () Returns an `asyncgen_hooks' object, which is similar to a *note namedtuple: 1b7. of the form ‘(firstiter, finalizer)’, where `firstiter' and `finalizer' are expected to be either ‘None’ or functions which take an *note asynchronous generator iterator: 335c. as an argument, and are used to schedule finalization of an asynchronous generator by an event loop. New in version 3.6: See PEP 525(5) for more details. Note: This function has been added on a provisional basis (see PEP 411(6) for details.) -- Function: sys.get_coroutine_origin_tracking_depth () Get the current coroutine origin tracking depth, as set by *note set_coroutine_origin_tracking_depth(): 3f3. New in version 3.7. Note: This function has been added on a provisional basis (see PEP 411(7) for details.) Use it only for debugging purposes. -- Data: sys.hash_info A *note named tuple: aa3. giving parameters of the numeric hash implementation. For more details about hashing of numeric types, see *note Hashing of numeric types: 12d2. attribute explanation --------------------------------------------------------------------------------- ‘width’ width in bits used for hash values ‘modulus’ prime modulus P used for numeric hash scheme ‘inf’ hash value returned for a positive infinity ‘nan’ hash value returned for a nan ‘imag’ multiplier used for the imaginary part of a complex number ‘algorithm’ name of the algorithm for hashing of str, bytes, and memoryview ‘hash_bits’ internal output size of the hash algorithm ‘seed_bits’ size of the seed key of the hash algorithm New in version 3.2. Changed in version 3.4: Added `algorithm', `hash_bits' and `seed_bits' -- Data: sys.hexversion The version number encoded as a single integer. This is guaranteed to increase with each version, including proper support for non-production releases. For example, to test that the Python interpreter is at least version 1.5.2, use: if sys.hexversion >= 0x010502F0: # use some advanced feature ... else: # use an alternative implementation or warn the user ... This is called ‘hexversion’ since it only really looks meaningful when viewed as the result of passing it to the built-in *note hex(): c66. function. The *note named tuple: aa3. *note sys.version_info: b1a. may be used for a more human-friendly encoding of the same information. More details of ‘hexversion’ can be found at *note API and ABI Versioning: 335e. -- Data: sys.implementation An object containing information about the implementation of the currently running Python interpreter. The following attributes are required to exist in all Python implementations. `name' is the implementation’s identifier, e.g. ‘'cpython'’. The actual string is defined by the Python implementation, but it is guaranteed to be lower case. `version' is a named tuple, in the same format as *note sys.version_info: b1a. It represents the version of the Python `implementation'. This has a distinct meaning from the specific version of the Python `language' to which the currently running interpreter conforms, which ‘sys.version_info’ represents. For example, for PyPy 1.8 ‘sys.implementation.version’ might be ‘sys.version_info(1, 8, 0, 'final', 0)’, whereas ‘sys.version_info’ would be ‘sys.version_info(2, 7, 2, 'final', 0)’. For CPython they are the same value, since it is the reference implementation. `hexversion' is the implementation version in hexadecimal format, like *note sys.hexversion: 335d. `cache_tag' is the tag used by the import machinery in the filenames of cached modules. By convention, it would be a composite of the implementation’s name and version, like ‘'cpython-33'’. However, a Python implementation may use some other value if appropriate. If ‘cache_tag’ is set to ‘None’, it indicates that module caching should be disabled. *note sys.implementation: 9aa. may contain additional attributes specific to the Python implementation. These non-standard attributes must start with an underscore, and are not described here. Regardless of its contents, *note sys.implementation: 9aa. will not change during a run of the interpreter, nor between implementation versions. (It may change between Python language versions, however.) See PEP 421(8) for more information. New in version 3.3. Note: The addition of new required attributes must go through the normal PEP process. See PEP 421(9) for more information. -- Data: sys.int_info A *note named tuple: aa3. that holds information about Python’s internal representation of integers. The attributes are read only. Attribute Explanation --------------------------------------------------------------------------------- ‘bits_per_digit’ number of bits held in each digit. Python integers are stored internally in base ‘2**int_info.bits_per_digit’ ‘sizeof_digit’ size in bytes of the C type used to represent a digit New in version 3.1. -- Data: sys.__interactivehook__ When this attribute exists, its value is automatically called (with no arguments) when the interpreter is launched in *note interactive mode: 8e3. This is done after the *note PYTHONSTARTUP: 8e5. file is read, so that you can set this hook there. The *note site: eb. module *note sets this: 8e6. Raises an *note auditing event: fd1. ‘cpython.run_interactivehook’ with the hook object as the argument when the hook is called on startup. New in version 3.4. -- Function: sys.intern (string) Enter `string' in the table of “interned” strings and return the interned string – which is `string' itself or a copy. Interning strings is useful to gain a little performance on dictionary lookup – if the keys in a dictionary are interned, and the lookup key is interned, the key comparisons (after hashing) can be done by a pointer compare instead of a string compare. Normally, the names used in Python programs are automatically interned, and the dictionaries used to hold module, class or instance attributes have interned keys. Interned strings are not immortal; you must keep a reference to the return value of *note intern(): c6e. around to benefit from it. -- Function: sys.is_finalizing () Return *note True: 499. if the Python interpreter is *note shutting down: 763, *note False: 388. otherwise. New in version 3.5. -- Data: sys.last_type -- Data: sys.last_value -- Data: sys.last_traceback These three variables are not always defined; they are set when an exception is not handled and the interpreter prints an error message and a stack traceback. Their intended use is to allow an interactive user to import a debugger module and engage in post-mortem debugging without having to re-execute the command that caused the error. (Typical use is ‘import pdb; pdb.pm()’ to enter the post-mortem debugger; see *note pdb: c9. module for more information.) The meaning of the variables is the same as that of the return values from *note exc_info(): c5f. above. -- Data: sys.maxsize An integer giving the maximum value a variable of type ‘Py_ssize_t’ can take. It’s usually ‘2**31 - 1’ on a 32-bit platform and ‘2**63 - 1’ on a 64-bit platform. -- Data: sys.maxunicode An integer giving the value of the largest Unicode code point, i.e. ‘1114111’ (‘0x10FFFF’ in hexadecimal). Changed in version 3.3: Before PEP 393(10), ‘sys.maxunicode’ used to be either ‘0xFFFF’ or ‘0x10FFFF’, depending on the configuration option that specified whether Unicode characters were stored as UCS-2 or UCS-4. -- Data: sys.meta_path A list of *note meta path finder: 9b1. objects that have their *note find_spec(): 463. methods called to see if one of the objects can find the module to be imported. The *note find_spec(): 463. method is called with at least the absolute name of the module being imported. If the module to be imported is contained in a package, then the parent package’s *note __path__: f23. attribute is passed in as a second argument. The method returns a *note module spec: 3360, or ‘None’ if the module cannot be found. See also ........ *note importlib.abc.MetaPathFinder: 9b3. The abstract base class defining the interface of finder objects on *note meta_path: 5e6. *note importlib.machinery.ModuleSpec: 116b. The concrete class which *note find_spec(): 463. should return instances of. Changed in version 3.4: *note Module specs: 3360. were introduced in Python 3.4, by PEP 451(11). Earlier versions of Python looked for a method called *note find_module(): 462. This is still called as a fallback if a *note meta_path: 5e6. entry doesn’t have a *note find_spec(): 463. method. -- Data: sys.modules This is a dictionary that maps module names to modules which have already been loaded. This can be manipulated to force reloading of modules and other tricks. However, replacing the dictionary will not necessarily work as expected and deleting essential items from the dictionary may cause Python to fail. -- Data: sys.path A list of strings that specifies the search path for modules. Initialized from the environment variable *note PYTHONPATH: 953, plus an installation-dependent default. As initialized upon program startup, the first item of this list, ‘path[0]’, is the directory containing the script that was used to invoke the Python interpreter. If the script directory is not available (e.g. if the interpreter is invoked interactively or if the script is read from standard input), ‘path[0]’ is the empty string, which directs Python to search modules in the current directory first. Notice that the script directory is inserted `before' the entries inserted as a result of *note PYTHONPATH: 953. A program is free to modify this list for its own purposes. Only strings and bytes should be added to *note sys.path: 488.; all other data types are ignored during import. See also ........ Module *note site: eb. This describes how to use .pth files to extend *note sys.path: 488. -- Data: sys.path_hooks A list of callables that take a path argument to try to create a *note finder: 115f. for the path. If a finder can be created, it is to be returned by the callable, else raise *note ImportError: 334. Originally specified in PEP 302(12). -- Data: sys.path_importer_cache A dictionary acting as a cache for *note finder: 115f. objects. The keys are paths that have been passed to *note sys.path_hooks: 95c. and the values are the finders that are found. If a path is a valid file system path but no finder is found on *note sys.path_hooks: 95c. then ‘None’ is stored. Originally specified in PEP 302(13). Changed in version 3.3: ‘None’ is stored instead of *note imp.NullImporter: 9bb. when no finder is found. -- Data: sys.platform This string contains a platform identifier that can be used to append platform-specific components to *note sys.path: 488, for instance. For Unix systems, except on Linux and AIX, this is the lowercased OS name as returned by ‘uname -s’ with the first part of the version as returned by ‘uname -r’ appended, e.g. ‘'sunos5'’ or ‘'freebsd8'’, `at the time when Python was built'. Unless you want to test for a specific system version, it is therefore recommended to use the following idiom: if sys.platform.startswith('freebsd'): # FreeBSD-specific code here... elif sys.platform.startswith('linux'): # Linux-specific code here... elif sys.platform.startswith('aix'): # AIX-specific code here... For other systems, the values are: System ‘platform’ value ----------------------------------------------------- AIX ‘'aix'’ Linux ‘'linux'’ Windows ‘'win32'’ Windows/Cygwin ‘'cygwin'’ macOS ‘'darwin'’ Changed in version 3.3: On Linux, *note sys.platform: 2b1. doesn’t contain the major version anymore. It is always ‘'linux'’, instead of ‘'linux2'’ or ‘'linux3'’. Since older Python versions include the version number, it is recommended to always use the ‘startswith’ idiom presented above. Changed in version 3.8: On AIX, *note sys.platform: 2b1. doesn’t contain the major version anymore. It is always ‘'aix'’, instead of ‘'aix5'’ or ‘'aix7'’. Since older Python versions include the version number, it is recommended to always use the ‘startswith’ idiom presented above. See also ........ *note os.name: 1bb0. has a coarser granularity. *note os.uname(): a5d. gives system-dependent version information. The *note platform: ce. module provides detailed checks for the system’s identity. -- Data: sys.prefix A string giving the site-specific directory prefix where the platform independent Python files are installed; by default, this is the string ‘'/usr/local'’. This can be set at build time with the ‘--prefix’ argument to the ‘configure’ script. The main collection of Python library modules is installed in the directory ‘`prefix'/lib/python`X.Y'’ while the platform independent header files (all except ‘pyconfig.h’) are stored in ‘`prefix'/include/python`X.Y'’, where `X.Y' is the version number of Python, for example ‘3.2’. Note: If a *note virtual environment: 3321. is in effect, this value will be changed in ‘site.py’ to point to the virtual environment. The value for the Python installation will still be available, via *note base_prefix: 2d50. -- Data: sys.ps1 -- Data: sys.ps2 Strings specifying the primary and secondary prompt of the interpreter. These are only defined if the interpreter is in interactive mode. Their initial values in this case are ‘'>>> '’ and ‘'... '’. If a non-string object is assigned to either variable, its *note str(): 330. is re-evaluated each time the interpreter prepares to read a new interactive command; this can be used to implement a dynamic prompt. -- Function: sys.setcheckinterval (interval) Set the interpreter’s “check interval”. This integer value determines how often the interpreter checks for periodic things such as thread switches and signal handlers. The default is ‘100’, meaning the check is performed every 100 Python virtual instructions. Setting it to a larger value may increase performance for programs using threads. Setting it to a value ‘<=’ 0 checks every virtual instruction, maximizing responsiveness as well as overhead. Deprecated since version 3.2: This function doesn’t have an effect anymore, as the internal logic for thread switching and asynchronous tasks has been rewritten. Use *note setswitchinterval(): beb. instead. -- Function: sys.setdlopenflags (n) Set the flags used by the interpreter for ‘dlopen()’ calls, such as when the interpreter loads extension modules. Among other things, this will enable a lazy resolving of symbols when importing a module, if called as ‘sys.setdlopenflags(0)’. To share symbols across extension modules, call as ‘sys.setdlopenflags(os.RTLD_GLOBAL)’. Symbolic names for the flag values can be found in the *note os: c4. module (‘RTLD_xxx’ constants, e.g. *note os.RTLD_LAZY: a5f.). *note Availability: ffb.: Unix. -- Function: sys.setprofile (profilefunc) Set the system’s profile function, which allows you to implement a Python source code profiler in Python. See chapter *note The Python Profilers: 3282. for more information on the Python profiler. The system’s profile function is called similarly to the system’s trace function (see *note settrace(): e3e.), but it is called with different events, for example it isn’t called for each executed line of code (only on call and return, but the return event is reported even when an exception has been set). The function is thread-specific, but there is no way for the profiler to know about context switches between threads, so it does not make sense to use this in the presence of multiple threads. Also, its return value is not used, so it can simply return ‘None’. Error in the profile function will cause itself unset. Profile functions should have three arguments: `frame', `event', and `arg'. `frame' is the current stack frame. `event' is a string: ‘'call'’, ‘'return'’, ‘'c_call'’, ‘'c_return'’, or ‘'c_exception'’. `arg' depends on the event type. Raises an *note auditing event: fd1. ‘sys.setprofile’ with no arguments. The events have the following meaning: ‘'call'’ A function is called (or some other code block entered). The profile function is called; `arg' is ‘None’. ‘'return'’ A function (or other code block) is about to return. The profile function is called; `arg' is the value that will be returned, or ‘None’ if the event is caused by an exception being raised. ‘'c_call'’ A C function is about to be called. This may be an extension function or a built-in. `arg' is the C function object. ‘'c_return'’ A C function has returned. `arg' is the C function object. ‘'c_exception'’ A C function has raised an exception. `arg' is the C function object. -- Function: sys.setrecursionlimit (limit) Set the maximum depth of the Python interpreter stack to `limit'. This limit prevents infinite recursion from causing an overflow of the C stack and crashing Python. The highest possible limit is platform-dependent. A user may need to set the limit higher when they have a program that requires deep recursion and a platform that supports a higher limit. This should be done with care, because a too-high limit can lead to a crash. If the new limit is too low at the current recursion depth, a *note RecursionError: 634. exception is raised. Changed in version 3.5.1: A *note RecursionError: 634. exception is now raised if the new limit is too low at the current recursion depth. -- Function: sys.setswitchinterval (interval) Set the interpreter’s thread switch interval (in seconds). This floating-point value determines the ideal duration of the “timeslices” allocated to concurrently running Python threads. Please note that the actual value can be higher, especially if long-running internal functions or methods are used. Also, which thread becomes scheduled at the end of the interval is the operating system’s decision. The interpreter doesn’t have its own scheduler. New in version 3.2. -- Function: sys.settrace (tracefunc) Set the system’s trace function, which allows you to implement a Python source code debugger in Python. The function is thread-specific; for a debugger to support multiple threads, it must register a trace function using *note settrace(): e3e. for each thread being debugged or use *note threading.settrace(): 203d. Trace functions should have three arguments: `frame', `event', and `arg'. `frame' is the current stack frame. `event' is a string: ‘'call'’, ‘'line'’, ‘'return'’, ‘'exception'’ or ‘'opcode'’. `arg' depends on the event type. The trace function is invoked (with `event' set to ‘'call'’) whenever a new local scope is entered; it should return a reference to a local trace function to be used for the new scope, or ‘None’ if the scope shouldn’t be traced. The local trace function should return a reference to itself (or to another function for further tracing in that scope), or ‘None’ to turn off tracing in that scope. If there is any error occurred in the trace function, it will be unset, just like ‘settrace(None)’ is called. The events have the following meaning: ‘'call'’ A function is called (or some other code block entered). The global trace function is called; `arg' is ‘None’; the return value specifies the local trace function. ‘'line'’ The interpreter is about to execute a new line of code or re-execute the condition of a loop. The local trace function is called; `arg' is ‘None’; the return value specifies the new local trace function. See ‘Objects/lnotab_notes.txt’ for a detailed explanation of how this works. Per-line events may be disabled for a frame by setting ‘f_trace_lines’ to *note False: 388. on that frame. ‘'return'’ A function (or other code block) is about to return. The local trace function is called; `arg' is the value that will be returned, or ‘None’ if the event is caused by an exception being raised. The trace function’s return value is ignored. ‘'exception'’ An exception has occurred. The local trace function is called; `arg' is a tuple ‘(exception, value, traceback)’; the return value specifies the new local trace function. ‘'opcode'’ The interpreter is about to execute a new opcode (see *note dis: 38. for opcode details). The local trace function is called; `arg' is ‘None’; the return value specifies the new local trace function. Per-opcode events are not emitted by default: they must be explicitly requested by setting ‘f_trace_opcodes’ to *note True: 499. on the frame. Note that as an exception is propagated down the chain of callers, an ‘'exception'’ event is generated at each level. For more fine-grained usage, it’s possible to set a trace function by assigning ‘frame.f_trace = tracefunc’ explicitly, rather than relying on it being set indirectly via the return value from an already installed trace function. This is also required for activating the trace function on the current frame, which *note settrace(): e3e. doesn’t do. Note that in order for this to work, a global tracing function must have been installed with *note settrace(): e3e. in order to enable the runtime tracing machinery, but it doesn’t need to be the same tracing function (e.g. it could be a low overhead tracing function that simply returns ‘None’ to disable itself immediately on each frame). For more information on code and frame objects, refer to *note The standard type hierarchy: 10c0. Raises an *note auditing event: fd1. ‘sys.settrace’ with no arguments. `CPython implementation detail:' The *note settrace(): e3e. function is intended only for implementing debuggers, profilers, coverage tools and the like. Its behavior is part of the implementation platform, rather than part of the language definition, and thus may not be available in all Python implementations. Changed in version 3.7: ‘'opcode'’ event type added; ‘f_trace_lines’ and ‘f_trace_opcodes’ attributes added to frames -- Function: sys.set_asyncgen_hooks (firstiter, finalizer) Accepts two optional keyword arguments which are callables that accept an *note asynchronous generator iterator: 335c. as an argument. The `firstiter' callable will be called when an asynchronous generator is iterated for the first time. The `finalizer' will be called when an asynchronous generator is about to be garbage collected. Raises an *note auditing event: fd1. ‘sys.set_asyncgen_hooks_firstiter’ with no arguments. Raises an *note auditing event: fd1. ‘sys.set_asyncgen_hooks_finalizer’ with no arguments. Two auditing events are raised because the underlying API consists of two calls, each of which must raise its own event. New in version 3.6: See PEP 525(14) for more details, and for a reference example of a `finalizer' method see the implementation of ‘asyncio.Loop.shutdown_asyncgens’ in Lib/asyncio/base_events.py(15) Note: This function has been added on a provisional basis (see PEP 411(16) for details.) -- Function: sys.set_coroutine_origin_tracking_depth (depth) Allows enabling or disabling coroutine origin tracking. When enabled, the ‘cr_origin’ attribute on coroutine objects will contain a tuple of (filename, line number, function name) tuples describing the traceback where the coroutine object was created, with the most recent call first. When disabled, ‘cr_origin’ will be None. To enable, pass a `depth' value greater than zero; this sets the number of frames whose information will be captured. To disable, pass set `depth' to zero. This setting is thread-specific. New in version 3.7. Note: This function has been added on a provisional basis (see PEP 411(17) for details.) Use it only for debugging purposes. -- Function: sys._enablelegacywindowsfsencoding () Changes the default filesystem encoding and errors mode to ‘mbcs’ and ‘replace’ respectively, for consistency with versions of Python prior to 3.6. This is equivalent to defining the *note PYTHONLEGACYWINDOWSFSENCODING: 4f7. environment variable before launching Python. *note Availability: ffb.: Windows. New in version 3.6: See PEP 529(18) for more details. -- Data: sys.stdin -- Data: sys.stdout -- Data: sys.stderr *note File objects: b42. used by the interpreter for standard input, output and errors: * ‘stdin’ is used for all interactive input (including calls to *note input(): c6b.); * ‘stdout’ is used for the output of *note print(): 886. and *note expression: 3350. statements and for the prompts of *note input(): c6b.; * The interpreter’s own prompts and its error messages go to ‘stderr’. These streams are regular *note text files: f3a. like those returned by the *note open(): 4f0. function. Their parameters are chosen as follows: * The character encoding is platform-dependent. Non-Windows platforms use the locale encoding (see *note locale.getpreferredencoding(): 3a5.). On Windows, UTF-8 is used for the console device. Non-character devices such as disk files and pipes use the system locale encoding (i.e. the ANSI codepage). Non-console character devices such as NUL (i.e. where ‘isatty()’ returns ‘True’) use the value of the console input and output codepages at startup, respectively for stdin and stdout/stderr. This defaults to the system locale encoding if the process is not initially attached to a console. The special behaviour of the console can be overridden by setting the environment variable PYTHONLEGACYWINDOWSSTDIO before starting Python. In that case, the console codepages are used as for any other character device. Under all platforms, you can override the character encoding by setting the *note PYTHONIOENCODING: 92f. environment variable before starting Python or by using the new *note -X: 155. ‘utf8’ command line option and *note PYTHONUTF8: 311. environment variable. However, for the Windows console, this only applies when *note PYTHONLEGACYWINDOWSSTDIO: 4fa. is also set. * When interactive, ‘stdout’ and ‘stderr’ streams are line-buffered. Otherwise, they are block-buffered like regular text files. You can override this value with the *note -u: fe3. command-line option. Note: To write or read binary data from/to the standard streams, use the underlying binary *note buffer: c3a. object. For example, to write bytes to *note stdout: 30e, use ‘sys.stdout.buffer.write(b'abc')’. However, if you are writing a library (and do not control in which context its code will be executed), be aware that the standard streams may be replaced with file-like objects like *note io.StringIO: 82d. which do not support the ‘buffer’ attribute. -- Data: sys.__stdin__ -- Data: sys.__stdout__ -- Data: sys.__stderr__ These objects contain the original values of ‘stdin’, ‘stderr’ and ‘stdout’ at the start of the program. They are used during finalization, and could be useful to print to the actual standard stream no matter if the ‘sys.std*’ object has been redirected. It can also be used to restore the actual files to known working file objects in case they have been overwritten with a broken object. However, the preferred way to do this is to explicitly save the previous stream before replacing it, and restore the saved object. Note: Under some conditions ‘stdin’, ‘stdout’ and ‘stderr’ as well as the original values ‘__stdin__’, ‘__stdout__’ and ‘__stderr__’ can be ‘None’. It is usually the case for Windows GUI apps that aren’t connected to a console and Python apps started with ‘pythonw’. -- Data: sys.thread_info A *note named tuple: aa3. holding information about the thread implementation. Attribute Explanation ------------------------------------------------------------------------------------- ‘name’ Name of the thread implementation: * ‘'nt'’: Windows threads * ‘'pthread'’: POSIX threads * ‘'solaris'’: Solaris threads ‘lock’ Name of the lock implementation: * ‘'semaphore'’: a lock uses a semaphore * ‘'mutex+cond'’: a lock uses a mutex and a condition variable * ‘None’ if this information is unknown *note version: 5d3. Name and version of the thread library. It is a string, or ‘None’ if this information is unknown. New in version 3.3. -- Data: sys.tracebacklimit When this variable is set to an integer value, it determines the maximum number of levels of traceback information printed when an unhandled exception occurs. The default is ‘1000’. When set to ‘0’ or less, all traceback information is suppressed and only the exception type and value are printed. -- Function: sys.unraisablehook (unraisable, /) Handle an unraisable exception. Called when an exception has occurred but there is no way for Python to handle it. For example, when a destructor raises an exception or during garbage collection (*note gc.collect(): 22e.). The `unraisable' argument has the following attributes: * `exc_type': Exception type. * `exc_value': Exception value, can be ‘None’. * `exc_traceback': Exception traceback, can be ‘None’. * `err_msg': Error message, can be ‘None’. * `object': Object causing the exception, can be ‘None’. The default hook formats `err_msg' and `object' as: ‘f'{err_msg}: {object!r}'’; use “Exception ignored in” error message if `err_msg' is ‘None’. *note sys.unraisablehook(): 22d. can be overridden to control how unraisable exceptions are handled. Storing `exc_value' using a custom hook can create a reference cycle. It should be cleared explicitly to break the reference cycle when the exception is no longer needed. Storing `object' using a custom hook can resurrect it if it is set to an object which is being finalized. Avoid storing `object' after the custom hook completes to avoid resurrecting objects. See also *note excepthook(): e63. which handles uncaught exceptions. Raise an auditing event ‘sys.unraisablehook’ with arguments ‘hook’, ‘unraisable’ when an exception that cannot be handled occurs. The ‘unraisable’ object is the same as what will be passed to the hook. If no hook has been set, ‘hook’ may be ‘None’. New in version 3.8. -- Data: sys.version A string containing the version number of the Python interpreter plus additional information on the build number and compiler used. This string is displayed when the interactive interpreter is started. Do not extract version information out of it, rather, use *note version_info: b1a. and the functions provided by the *note platform: ce. module. -- Data: sys.api_version The C API version for this interpreter. Programmers may find this useful when debugging version conflicts between Python and extension modules. -- Data: sys.version_info A tuple containing the five components of the version number: `major', `minor', `micro', `releaselevel', and `serial'. All values except `releaselevel' are integers; the release level is ‘'alpha'’, ‘'beta'’, ‘'candidate'’, or ‘'final'’. The ‘version_info’ value corresponding to the Python version 2.0 is ‘(2, 0, 0, 'final', 0)’. The components can also be accessed by name, so ‘sys.version_info[0]’ is equivalent to ‘sys.version_info.major’ and so on. Changed in version 3.1: Added named component attributes. -- Data: sys.warnoptions This is an implementation detail of the warnings framework; do not modify this value. Refer to the *note warnings: 126. module for more information on the warnings framework. -- Data: sys.winver The version number used to form registry keys on Windows platforms. This is stored as string resource 1000 in the Python DLL. The value is normally the first three characters of *note version: 5d3. It is provided in the *note sys: fd. module for informational purposes; modifying this value has no effect on the registry keys used by Python. *note Availability: ffb.: Windows. -- Data: sys._xoptions A dictionary of the various implementation-specific flags passed through the *note -X: 155. command-line option. Option names are either mapped to their values, if given explicitly, or to *note True: 499. Example: $ ./python -Xa=b -Xc Python 3.2a3+ (py3k, Oct 16 2010, 20:14:50) [GCC 4.4.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import sys >>> sys._xoptions {'a': 'b', 'c': True} `CPython implementation detail:' This is a CPython-specific way of accessing options passed through *note -X: 155. Other implementations may export them through other means, or not at all. New in version 3.2. Citations ......... (C99) ISO/IEC 9899:1999. “Programming languages – C.” A public draft of this standard is available at ‘http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf’. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3149 (2) https://www.python.org/dev/peps/pep-0578 (3) https://www.python.org/dev/peps/pep-0529 (4) https://code.activestate.com/recipes/577504 (5) https://www.python.org/dev/peps/pep-0525 (6) https://www.python.org/dev/peps/pep-0411 (7) https://www.python.org/dev/peps/pep-0411 (8) https://www.python.org/dev/peps/pep-0421 (9) https://www.python.org/dev/peps/pep-0421 (10) https://www.python.org/dev/peps/pep-0393 (11) https://www.python.org/dev/peps/pep-0451 (12) https://www.python.org/dev/peps/pep-0302 (13) https://www.python.org/dev/peps/pep-0302 (14) https://www.python.org/dev/peps/pep-0525 (15) https://github.com/python/cpython/tree/3.8/Lib/asyncio/base_events.py (16) https://www.python.org/dev/peps/pep-0411 (17) https://www.python.org/dev/peps/pep-0411 (18) https://www.python.org/dev/peps/pep-0529  File: python.info, Node: sysconfig — Provide access to Python’s configuration information, Next: builtins — Built-in objects, Prev: sys — System-specific parameters and functions, Up: Python Runtime Services 5.29.2 ‘sysconfig’ — Provide access to Python’s configuration information ------------------------------------------------------------------------- New in version 3.2. `Source code:' Lib/sysconfig.py(1) __________________________________________________________________ The *note sysconfig: fe. module provides access to Python’s configuration information like the list of installation paths and the configuration variables relevant for the current platform. * Menu: * Configuration variables:: * Installation paths:: * Other functions: Other functions<3>. * Using sysconfig as a script:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/sysconfig.py  File: python.info, Node: Configuration variables, Next: Installation paths, Up: sysconfig — Provide access to Python’s configuration information 5.29.2.1 Configuration variables ................................ A Python distribution contains a ‘Makefile’ and a ‘pyconfig.h’ header file that are necessary to build both the Python binary itself and third-party C extensions compiled using *note distutils: 39. *note sysconfig: fe. puts all variables found in these files in a dictionary that can be accessed using *note get_config_vars(): 965. or *note get_config_var(): 964. Notice that on Windows, it’s a much smaller set. -- Function: sysconfig.get_config_vars (*args) With no arguments, return a dictionary of all configuration variables relevant for the current platform. With arguments, return a list of values that result from looking up each argument in the configuration variable dictionary. For each argument, if the value is not found, return ‘None’. -- Function: sysconfig.get_config_var (name) Return the value of a single variable `name'. Equivalent to ‘get_config_vars().get(name)’. If `name' is not found, return ‘None’. Example of usage: >>> import sysconfig >>> sysconfig.get_config_var('Py_ENABLE_SHARED') 0 >>> sysconfig.get_config_var('LIBDIR') '/usr/local/lib' >>> sysconfig.get_config_vars('AR', 'CXX') ['ar', 'g++']  File: python.info, Node: Installation paths, Next: Other functions<3>, Prev: Configuration variables, Up: sysconfig — Provide access to Python’s configuration information 5.29.2.2 Installation paths ........................... Python uses an installation scheme that differs depending on the platform and on the installation options. These schemes are stored in *note sysconfig: fe. under unique identifiers based on the value returned by *note os.name: 1bb0. Every new component that is installed using *note distutils: 39. or a Distutils-based system will follow the same scheme to copy its file in the right places. Python currently supports seven schemes: - `posix_prefix': scheme for POSIX platforms like Linux or Mac OS X. This is the default scheme used when Python or a component is installed. - `posix_home': scheme for POSIX platforms used when a `home' option is used upon installation. This scheme is used when a component is installed through Distutils with a specific home prefix. - `posix_user': scheme for POSIX platforms used when a component is installed through Distutils and the `user' option is used. This scheme defines paths located under the user home directory. - `nt': scheme for NT platforms like Windows. - `nt_user': scheme for NT platforms, when the `user' option is used. Each scheme is itself composed of a series of paths and each path has a unique identifier. Python currently uses eight paths: - `stdlib': directory containing the standard Python library files that are not platform-specific. - `platstdlib': directory containing the standard Python library files that are platform-specific. - `platlib': directory for site-specific, platform-specific files. - `purelib': directory for site-specific, non-platform-specific files. - `include': directory for non-platform-specific header files. - `platinclude': directory for platform-specific header files. - `scripts': directory for script files. - `data': directory for data files. *note sysconfig: fe. provides some functions to determine these paths. -- Function: sysconfig.get_scheme_names () Return a tuple containing all schemes currently supported in *note sysconfig: fe. -- Function: sysconfig.get_path_names () Return a tuple containing all path names currently supported in *note sysconfig: fe. -- Function: sysconfig.get_path (name[, scheme[, vars[, expand]]]) Return an installation path corresponding to the path `name', from the install scheme named `scheme'. `name' has to be a value from the list returned by *note get_path_names(): 336b. *note sysconfig: fe. stores installation paths corresponding to each path name, for each platform, with variables to be expanded. For instance the `stdlib' path for the `nt' scheme is: ‘{base}/Lib’. *note get_path(): cbe. will use the variables returned by *note get_config_vars(): 965. to expand the path. All variables have default values for each platform so one may call this function and get the default value. If `scheme' is provided, it must be a value from the list returned by *note get_scheme_names(): 336a. Otherwise, the default scheme for the current platform is used. If `vars' is provided, it must be a dictionary of variables that will update the dictionary return by *note get_config_vars(): 965. If `expand' is set to ‘False’, the path will not be expanded using the variables. If `name' is not found, return ‘None’. -- Function: sysconfig.get_paths ([scheme[, vars[, expand]]]) Return a dictionary containing all installation paths corresponding to an installation scheme. See *note get_path(): cbe. for more information. If `scheme' is not provided, will use the default scheme for the current platform. If `vars' is provided, it must be a dictionary of variables that will update the dictionary used to expand the paths. If `expand' is set to false, the paths will not be expanded. If `scheme' is not an existing scheme, *note get_paths(): bd9. will raise a *note KeyError: 2c7.  File: python.info, Node: Other functions<3>, Next: Using sysconfig as a script, Prev: Installation paths, Up: sysconfig — Provide access to Python’s configuration information 5.29.2.3 Other functions ........................ -- Function: sysconfig.get_python_version () Return the ‘MAJOR.MINOR’ Python version number as a string. Similar to ‘'%d.%d' % sys.version_info[:2]’. -- Function: sysconfig.get_platform () Return a string that identifies the current platform. This is used mainly to distinguish platform-specific build directories and platform-specific built distributions. Typically includes the OS name and version and the architecture (as supplied by ‘os.uname()’), although the exact information included depends on the OS; e.g., on Linux, the kernel version isn’t particularly important. Examples of returned values: - linux-i586 - linux-alpha (?) - solaris-2.6-sun4u Windows will return one of: - win-amd64 (64bit Windows on AMD64, aka x86_64, Intel64, and EM64T) - win32 (all others - specifically, sys.platform is returned) Mac OS X can return: - macosx-10.6-ppc - macosx-10.4-ppc64 - macosx-10.3-i386 - macosx-10.4-fat For other non-POSIX platforms, currently just returns *note sys.platform: 2b1. -- Function: sysconfig.is_python_build () Return ‘True’ if the running Python interpreter was built from source and is being run from its built location, and not from a location resulting from e.g. running ‘make install’ or installing via a binary installer. -- Function: sysconfig.parse_config_h (fp[, vars]) Parse a ‘config.h’-style file. `fp' is a file-like object pointing to the ‘config.h’-like file. A dictionary containing name/value pairs is returned. If an optional dictionary is passed in as the second argument, it is used instead of a new dictionary, and updated with the values read in the file. -- Function: sysconfig.get_config_h_filename () Return the path of ‘pyconfig.h’. -- Function: sysconfig.get_makefile_filename () Return the path of ‘Makefile’.  File: python.info, Node: Using sysconfig as a script, Prev: Other functions<3>, Up: sysconfig — Provide access to Python’s configuration information 5.29.2.4 Using ‘sysconfig’ as a script ...................................... You can use *note sysconfig: fe. as a script with Python’s `-m' option: $ python -m sysconfig Platform: "macosx-10.4-i386" Python version: "3.2" Current installation scheme: "posix_prefix" Paths: data = "/usr/local" include = "/Users/tarek/Dev/svn.python.org/py3k/Include" platinclude = "." platlib = "/usr/local/lib/python3.2/site-packages" platstdlib = "/usr/local/lib/python3.2" purelib = "/usr/local/lib/python3.2/site-packages" scripts = "/usr/local/bin" stdlib = "/usr/local/lib/python3.2" Variables: AC_APPLE_UNIVERSAL_BUILD = "0" AIX_GENUINE_CPLUSPLUS = "0" AR = "ar" ARFLAGS = "rc" ... This call will print in the standard output the information returned by *note get_platform(): bd7, *note get_python_version(): bd8, *note get_path(): cbe. and *note get_config_vars(): 965.  File: python.info, Node: builtins — Built-in objects, Next: __main__ — Top-level script environment, Prev: sysconfig — Provide access to Python’s configuration information, Up: Python Runtime Services 5.29.3 ‘builtins’ — Built-in objects ------------------------------------ __________________________________________________________________ This module provides direct access to all ‘built-in’ identifiers of Python; for example, ‘builtins.open’ is the full name for the built-in function *note open(): 4f0. See *note Built-in Functions: bf3. and *note Built-in Constants: 12b5. for documentation. This module is not normally accessed explicitly by most applications, but can be useful in modules that provide objects with the same name as a built-in value, but in which the built-in of that name is also needed. For example, in a module that wants to implement an *note open(): 4f0. function that wraps the built-in *note open(): 4f0, this module can be used directly: import builtins def open(path): f = builtins.open(path, 'r') return UpperCaser(f) class UpperCaser: '''Wrapper around a file that converts output to upper-case.''' def __init__(self, f): self._f = f def read(self, count=-1): return self._f.read(count).upper() # ... As an implementation detail, most modules have the name ‘__builtins__’ made available as part of their globals. The value of ‘__builtins__’ is normally either this module or the value of this module’s *note __dict__: 4fc. attribute. Since this is an implementation detail, it may not be used by alternate implementations of Python.  File: python.info, Node: __main__ — Top-level script environment, Next: warnings — Warning control, Prev: builtins — Built-in objects, Up: Python Runtime Services 5.29.4 ‘__main__’ — Top-level script environment ------------------------------------------------ __________________________________________________________________ ‘'__main__'’ is the name of the scope in which top-level code executes. A module’s __name__ is set equal to ‘'__main__'’ when read from standard input, a script, or from an interactive prompt. A module can discover whether or not it is running in the main scope by checking its own ‘__name__’, which allows a common idiom for conditionally executing code in a module when it is run as a script or with ‘python -m’ but not when it is imported: if __name__ == "__main__": # execute only if run as a script main() For a package, the same effect can be achieved by including a ‘__main__.py’ module, the contents of which will be executed when the module is run with ‘-m’.  File: python.info, Node: warnings — Warning control, Next: dataclasses — Data Classes, Prev: __main__ — Top-level script environment, Up: Python Runtime Services 5.29.5 ‘warnings’ — Warning control ----------------------------------- `Source code:' Lib/warnings.py(1) __________________________________________________________________ Warning messages are typically issued in situations where it is useful to alert the user of some condition in a program, where that condition (normally) doesn’t warrant raising an exception and terminating the program. For example, one might want to issue a warning when a program uses an obsolete module. Python programmers issue warnings by calling the *note warn(): e58. function defined in this module. (C programmers use *note PyErr_WarnEx(): db1.; see *note Exception Handling: 3377. for details). Warning messages are normally written to *note sys.stderr: 30f, but their disposition can be changed flexibly, from ignoring all warnings to turning them into exceptions. The disposition of warnings can vary based on the *note warning category: 13c1, the text of the warning message, and the source location where it is issued. Repetitions of a particular warning for the same source location are typically suppressed. There are two stages in warning control: first, each time a warning is issued, a determination is made whether a message should be issued or not; next, if a message is to be issued, it is formatted and printed using a user-settable hook. The determination whether to issue a warning message is controlled by the *note warning filter: fe7, which is a sequence of matching rules and actions. Rules can be added to the filter by calling *note filterwarnings(): e07. and reset to its default state by calling *note resetwarnings(): 3378. The printing of warning messages is done by calling *note showwarning(): 3379, which may be overridden; the default implementation of this function formats the message by calling *note formatwarning(): 1dad, which is also available for use by custom implementations. See also ........ *note logging.captureWarnings(): 1dac. allows you to handle all warnings with the standard logging infrastructure. * Menu: * Warning Categories:: * The Warnings Filter:: * Temporarily Suppressing Warnings:: * Testing Warnings:: * Updating Code For New Versions of Dependencies:: * Available Functions:: * Available Context Managers:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/warnings.py  File: python.info, Node: Warning Categories, Next: The Warnings Filter, Up: warnings — Warning control 5.29.5.1 Warning Categories ........................... There are a number of built-in exceptions that represent warning categories. This categorization is useful to be able to filter out groups of warnings. While these are technically *note built-in exceptions: 13bf, they are documented here, because conceptually they belong to the warnings mechanism. User code can define additional warning categories by subclassing one of the standard warning categories. A warning category must always be a subclass of the *note Warning: 13c2. class. The following warnings category classes are currently defined: Class Description ------------------------------------------------------------------------------------------- *note Warning: 13c2. This is the base class of all warning category classes. It is a subclass of *note Exception: 1a9. *note UserWarning: 13c3. The default category for *note warn(): e58. *note DeprecationWarning: 278. Base category for warnings about deprecated features when those warnings are intended for other Python developers (ignored by default, unless triggered by code in ‘__main__’). *note SyntaxWarning: 191. Base category for warnings about dubious syntactic features. *note RuntimeWarning: 2c0. Base category for warnings about dubious runtime features. *note FutureWarning: 325. Base category for warnings about deprecated features when those warnings are intended for end users of applications that are written in Python. *note PendingDeprecationWarning: 279. Base category for warnings about features that will be deprecated in the future (ignored by default). *note ImportWarning: 5d8. Base category for warnings triggered during the process of importing a module (ignored by default). *note UnicodeWarning: d87. Base category for warnings related to Unicode. *note BytesWarning: 4b5. Base category for warnings related to *note bytes: 331. and *note bytearray: 332. *note ResourceWarning: 4d0. Base category for warnings related to resource usage. Changed in version 3.7: Previously *note DeprecationWarning: 278. and *note FutureWarning: 325. were distinguished based on whether a feature was being removed entirely or changing its behaviour. They are now distinguished based on their intended audience and the way they’re handled by the default warnings filters.  File: python.info, Node: The Warnings Filter, Next: Temporarily Suppressing Warnings, Prev: Warning Categories, Up: warnings — Warning control 5.29.5.2 The Warnings Filter ............................ The warnings filter controls whether warnings are ignored, displayed, or turned into errors (raising an exception). Conceptually, the warnings filter maintains an ordered list of filter specifications; any specific warning is matched against each filter specification in the list in turn until a match is found; the filter determines the disposition of the match. Each entry is a tuple of the form (`action', `message', `category', `module', `lineno'), where: * `action' is one of the following strings: Value Disposition ----------------------------------------------------------------------- ‘"default"’ print the first occurrence of matching warnings for each location (module + line number) where the warning is issued ‘"error"’ turn matching warnings into exceptions ‘"ignore"’ never print matching warnings ‘"always"’ always print matching warnings ‘"module"’ print the first occurrence of matching warnings for each module where the warning is issued (regardless of line number) ‘"once"’ print only the first occurrence of matching warnings, regardless of location * `message' is a string containing a regular expression that the start of the warning message must match. The expression is compiled to always be case-insensitive. * `category' is a class (a subclass of *note Warning: 13c2.) of which the warning category must be a subclass in order to match. * `module' is a string containing a regular expression that the module name must match. The expression is compiled to be case-sensitive. * `lineno' is an integer that the line number where the warning occurred must match, or ‘0’ to match all line numbers. Since the *note Warning: 13c2. class is derived from the built-in *note Exception: 1a9. class, to turn a warning into an error we simply raise ‘category(message)’. If a warning is reported and doesn’t match any registered filter then the “default” action is applied (hence its name). * Menu: * Describing Warning Filters:: * Default Warning Filter:: * Overriding the default filter::  File: python.info, Node: Describing Warning Filters, Next: Default Warning Filter, Up: The Warnings Filter 5.29.5.3 Describing Warning Filters ................................... The warnings filter is initialized by *note -W: 417. options passed to the Python interpreter command line and the *note PYTHONWARNINGS: 418. environment variable. The interpreter saves the arguments for all supplied entries without interpretation in *note sys.warnoptions: 416.; the *note warnings: 126. module parses these when it is first imported (invalid options are ignored, after printing a message to *note sys.stderr: 30f.). Individual warnings filters are specified as a sequence of fields separated by colons: action:message:category:module:line The meaning of each of these fields is as described in *note The Warnings Filter: fe7. When listing multiple filters on a single line (as for *note PYTHONWARNINGS: 418.), the individual filters are separated by commas and the filters listed later take precedence over those listed before them (as they’re applied left-to-right, and the most recently applied filters take precedence over earlier ones). Commonly used warning filters apply to either all warnings, warnings in a particular category, or warnings raised by particular modules or packages. Some examples: default # Show all warnings (even those ignored by default) ignore # Ignore all warnings error # Convert all warnings to errors error::ResourceWarning # Treat ResourceWarning messages as errors default::DeprecationWarning # Show DeprecationWarning messages ignore,default:::mymodule # Only report warnings triggered by "mymodule" error:::mymodule[.*] # Convert warnings to errors in "mymodule" # and any subpackages of "mymodule"  File: python.info, Node: Default Warning Filter, Next: Overriding the default filter, Prev: Describing Warning Filters, Up: The Warnings Filter 5.29.5.4 Default Warning Filter ............................... By default, Python installs several warning filters, which can be overridden by the *note -W: 417. command-line option, the *note PYTHONWARNINGS: 418. environment variable and calls to *note filterwarnings(): e07. In regular release builds, the default warning filter has the following entries (in order of precedence): default::DeprecationWarning:__main__ ignore::DeprecationWarning ignore::PendingDeprecationWarning ignore::ImportWarning ignore::ResourceWarning In debug builds, the list of default warning filters is empty. Changed in version 3.2: *note DeprecationWarning: 278. is now ignored by default in addition to *note PendingDeprecationWarning: 279. Changed in version 3.7: *note DeprecationWarning: 278. is once again shown by default when triggered directly by code in ‘__main__’. Changed in version 3.7: *note BytesWarning: 4b5. no longer appears in the default filter list and is instead configured via *note sys.warnoptions: 416. when *note -b: 415. is specified twice.  File: python.info, Node: Overriding the default filter, Prev: Default Warning Filter, Up: The Warnings Filter 5.29.5.5 Overriding the default filter ...................................... Developers of applications written in Python may wish to hide `all' Python level warnings from their users by default, and only display them when running tests or otherwise working on the application. The *note sys.warnoptions: 416. attribute used to pass filter configurations to the interpreter can be used as a marker to indicate whether or not warnings should be disabled: import sys if not sys.warnoptions: import warnings warnings.simplefilter("ignore") Developers of test runners for Python code are advised to instead ensure that `all' warnings are displayed by default for the code under test, using code like: import sys if not sys.warnoptions: import os, warnings warnings.simplefilter("default") # Change the filter in this process os.environ["PYTHONWARNINGS"] = "default" # Also affect subprocesses Finally, developers of interactive shells that run user code in a namespace other than ‘__main__’ are advised to ensure that *note DeprecationWarning: 278. messages are made visible by default, using code like the following (where ‘user_ns’ is the module used to execute code entered interactively): import warnings warnings.filterwarnings("default", category=DeprecationWarning, module=user_ns.get("__name__"))  File: python.info, Node: Temporarily Suppressing Warnings, Next: Testing Warnings, Prev: The Warnings Filter, Up: warnings — Warning control 5.29.5.6 Temporarily Suppressing Warnings ......................................... If you are using code that you know will raise a warning, such as a deprecated function, but do not want to see the warning (even when warnings have been explicitly configured via the command line), then it is possible to suppress the warning using the *note catch_warnings: 317b. context manager: import warnings def fxn(): warnings.warn("deprecated", DeprecationWarning) with warnings.catch_warnings(): warnings.simplefilter("ignore") fxn() While within the context manager all warnings will simply be ignored. This allows you to use known-deprecated code without having to see the warning while not suppressing the warning for other code that might not be aware of its use of deprecated code. Note: this can only be guaranteed in a single-threaded application. If two or more threads use the *note catch_warnings: 317b. context manager at the same time, the behavior is undefined.  File: python.info, Node: Testing Warnings, Next: Updating Code For New Versions of Dependencies, Prev: Temporarily Suppressing Warnings, Up: warnings — Warning control 5.29.5.7 Testing Warnings ......................... To test warnings raised by code, use the *note catch_warnings: 317b. context manager. With it you can temporarily mutate the warnings filter to facilitate your testing. For instance, do the following to capture all raised warnings to check: import warnings def fxn(): warnings.warn("deprecated", DeprecationWarning) with warnings.catch_warnings(record=True) as w: # Cause all warnings to always be triggered. warnings.simplefilter("always") # Trigger a warning. fxn() # Verify some things assert len(w) == 1 assert issubclass(w[-1].category, DeprecationWarning) assert "deprecated" in str(w[-1].message) One can also cause all warnings to be exceptions by using ‘error’ instead of ‘always’. One thing to be aware of is that if a warning has already been raised because of a ‘once’/‘default’ rule, then no matter what filters are set the warning will not be seen again unless the warnings registry related to the warning has been cleared. Once the context manager exits, the warnings filter is restored to its state when the context was entered. This prevents tests from changing the warnings filter in unexpected ways between tests and leading to indeterminate test results. The *note showwarning(): 3379. function in the module is also restored to its original value. Note: this can only be guaranteed in a single-threaded application. If two or more threads use the *note catch_warnings: 317b. context manager at the same time, the behavior is undefined. When testing multiple operations that raise the same kind of warning, it is important to test them in a manner that confirms each operation is raising a new warning (e.g. set warnings to be raised as exceptions and check the operations raise exceptions, check that the length of the warning list continues to increase after each operation, or else delete the previous entries from the warnings list before each new operation).  File: python.info, Node: Updating Code For New Versions of Dependencies, Next: Available Functions, Prev: Testing Warnings, Up: warnings — Warning control 5.29.5.8 Updating Code For New Versions of Dependencies ....................................................... Warning categories that are primarily of interest to Python developers (rather than end users of applications written in Python) are ignored by default. Notably, this “ignored by default” list includes *note DeprecationWarning: 278. (for every module except ‘__main__’), which means developers should make sure to test their code with typically ignored warnings made visible in order to receive timely notifications of future breaking API changes (whether in the standard library or third party packages). In the ideal case, the code will have a suitable test suite, and the test runner will take care of implicitly enabling all warnings when running tests (the test runner provided by the *note unittest: 11b. module does this). In less ideal cases, applications can be checked for use of deprecated interfaces by passing *note -Wd: 417. to the Python interpreter (this is shorthand for ‘-W default’) or setting ‘PYTHONWARNINGS=default’ in the environment. This enables default handling for all warnings, including those that are ignored by default. To change what action is taken for encountered warnings you can change what argument is passed to *note -W: 417. (e.g. ‘-W error’). See the *note -W: 417. flag for more details on what is possible.  File: python.info, Node: Available Functions, Next: Available Context Managers, Prev: Updating Code For New Versions of Dependencies, Up: warnings — Warning control 5.29.5.9 Available Functions ............................ -- Function: warnings.warn (message, category=None, stacklevel=1, source=None) Issue a warning, or maybe ignore it or raise an exception. The `category' argument, if given, must be a *note warning category class: 13c1.; it defaults to *note UserWarning: 13c3. Alternatively, `message' can be a *note Warning: 13c2. instance, in which case `category' will be ignored and ‘message.__class__’ will be used. In this case, the message text will be ‘str(message)’. This function raises an exception if the particular warning issued is changed into an error by the *note warnings filter: fe7. The `stacklevel' argument can be used by wrapper functions written in Python, like this: def deprecation(message): warnings.warn(message, DeprecationWarning, stacklevel=2) This makes the warning refer to ‘deprecation()’’s caller, rather than to the source of ‘deprecation()’ itself (since the latter would defeat the purpose of the warning message). `source', if supplied, is the destroyed object which emitted a *note ResourceWarning: 4d0. Changed in version 3.6: Added `source' parameter. -- Function: warnings.warn_explicit (message, category, filename, lineno, module=None, registry=None, module_globals=None, source=None) This is a low-level interface to the functionality of *note warn(): e58, passing in explicitly the message, category, filename and line number, and optionally the module name and the registry (which should be the ‘__warningregistry__’ dictionary of the module). The module name defaults to the filename with ‘.py’ stripped; if no registry is passed, the warning is never suppressed. `message' must be a string and `category' a subclass of *note Warning: 13c2. or `message' may be a *note Warning: 13c2. instance, in which case `category' will be ignored. `module_globals', if supplied, should be the global namespace in use by the code for which the warning is issued. (This argument is used to support displaying source for modules found in zipfiles or other non-filesystem import sources). `source', if supplied, is the destroyed object which emitted a *note ResourceWarning: 4d0. Changed in version 3.6: Add the `source' parameter. -- Function: warnings.showwarning (message, category, filename, lineno, file=None, line=None) Write a warning to a file. The default implementation calls ‘formatwarning(message, category, filename, lineno, line)’ and writes the resulting string to `file', which defaults to *note sys.stderr: 30f. You may replace this function with any callable by assigning to ‘warnings.showwarning’. `line' is a line of source code to be included in the warning message; if `line' is not supplied, *note showwarning(): 3379. will try to read the line specified by `filename' and `lineno'. -- Function: warnings.formatwarning (message, category, filename, lineno, line=None) Format a warning the standard way. This returns a string which may contain embedded newlines and ends in a newline. `line' is a line of source code to be included in the warning message; if `line' is not supplied, *note formatwarning(): 1dad. will try to read the line specified by `filename' and `lineno'. -- Function: warnings.filterwarnings (action, message='', category=Warning, module='', lineno=0, append=False) Insert an entry into the list of *note warnings filter specifications: fe7. The entry is inserted at the front by default; if `append' is true, it is inserted at the end. This checks the types of the arguments, compiles the `message' and `module' regular expressions, and inserts them as a tuple in the list of warnings filters. Entries closer to the front of the list override entries later in the list, if both match a particular warning. Omitted arguments default to a value that matches everything. -- Function: warnings.simplefilter (action, category=Warning, lineno=0, append=False) Insert a simple entry into the list of *note warnings filter specifications: fe7. The meaning of the function parameters is as for *note filterwarnings(): e07, but regular expressions are not needed as the filter inserted always matches any message in any module as long as the category and line number match. -- Function: warnings.resetwarnings () Reset the warnings filter. This discards the effect of all previous calls to *note filterwarnings(): e07, including that of the *note -W: 417. command line options and calls to *note simplefilter(): 317c.  File: python.info, Node: Available Context Managers, Prev: Available Functions, Up: warnings — Warning control 5.29.5.10 Available Context Managers .................................... -- Class: warnings.catch_warnings (*, record=False, module=None) A context manager that copies and, upon exit, restores the warnings filter and the *note showwarning(): 3379. function. If the `record' argument is *note False: 388. (the default) the context manager returns *note None: 157. on entry. If `record' is *note True: 499, a list is returned that is progressively populated with objects as seen by a custom *note showwarning(): 3379. function (which also suppresses output to ‘sys.stdout’). Each object in the list has attributes with the same names as the arguments to *note showwarning(): 3379. The `module' argument takes a module that will be used instead of the module returned when you import *note warnings: 126. whose filter will be protected. This argument exists primarily for testing the *note warnings: 126. module itself. Note: The *note catch_warnings: 317b. manager works by replacing and then later restoring the module’s *note showwarning(): 3379. function and internal list of filter specifications. This means the context manager is modifying global state and therefore is not thread-safe.  File: python.info, Node: dataclasses — Data Classes, Next: contextlib — Utilities for with-statement contexts, Prev: warnings — Warning control, Up: Python Runtime Services 5.29.6 ‘dataclasses’ — Data Classes ----------------------------------- `Source code:' Lib/dataclasses.py(1) __________________________________________________________________ This module provides a decorator and functions for automatically adding generated *note special method: 338b.s such as *note __init__(): d5e. and *note __repr__(): 33e. to user-defined classes. It was originally described in PEP 557(2). The member variables to use in these generated methods are defined using PEP 526(3) type annotations. For example this code: from dataclasses import dataclass @dataclass class InventoryItem: """Class for keeping track of an item in inventory.""" name: str unit_price: float quantity_on_hand: int = 0 def total_cost(self) -> float: return self.unit_price * self.quantity_on_hand Will add, among other things, a *note __init__(): d5e. that looks like: def __init__(self, name: str, unit_price: float, quantity_on_hand: int=0): self.name = name self.unit_price = unit_price self.quantity_on_hand = quantity_on_hand Note that this method is automatically added to the class: it is not directly specified in the ‘InventoryItem’ definition shown above. New in version 3.7. * Menu: * Module-level decorators, classes, and functions: Module-level decorators classes and functions. * Post-init processing:: * Class variables:: * Init-only variables:: * Frozen instances:: * Inheritance: Inheritance<2>. * Default factory functions:: * Mutable default values:: * Exceptions: Exceptions<17>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/dataclasses.py (2) https://www.python.org/dev/peps/pep-0557 (3) https://www.python.org/dev/peps/pep-0526  File: python.info, Node: Module-level decorators classes and functions, Next: Post-init processing, Up: dataclasses — Data Classes 5.29.6.1 Module-level decorators, classes, and functions ........................................................ -- Function: @dataclasses.dataclass (*, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False) This function is a *note decorator: 283. that is used to add generated *note special method: 338b.s to classes, as described below. The *note dataclass(): 33d. decorator examines the class to find ‘field’s. A ‘field’ is defined as class variable that has a *note type annotation: 61f. With two exceptions described below, nothing in *note dataclass(): 33d. examines the type specified in the variable annotation. The order of the fields in all of the generated methods is the order in which they appear in the class definition. The *note dataclass(): 33d. decorator will add various “dunder” methods to the class, described below. If any of the added methods already exist on the class, the behavior depends on the parameter, as documented below. The decorator returns the same class that is called on; no new class is created. If *note dataclass(): 33d. is used just as a simple decorator with no parameters, it acts as if it has the default values documented in this signature. That is, these three uses of *note dataclass(): 33d. are equivalent: @dataclass class C: ... @dataclass() class C: ... @dataclass(init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False) class C: ... The parameters to *note dataclass(): 33d. are: - ‘init’: If true (the default), a *note __init__(): d5e. method will be generated. If the class already defines *note __init__(): d5e, this parameter is ignored. - ‘repr’: If true (the default), a *note __repr__(): 33e. method will be generated. The generated repr string will have the class name and the name and repr of each field, in the order they are defined in the class. Fields that are marked as being excluded from the repr are not included. For example: ‘InventoryItem(name='widget', unit_price=3.0, quantity_on_hand=10)’. If the class already defines *note __repr__(): 33e, this parameter is ignored. - ‘eq’: If true (the default), an *note __eq__(): 33f. method will be generated. This method compares the class as if it were a tuple of its fields, in order. Both instances in the comparison must be of the identical type. If the class already defines *note __eq__(): 33f, this parameter is ignored. - ‘order’: If true (the default is ‘False’), *note __lt__(): c34, *note __le__(): ca0, *note __gt__(): ca1, and *note __ge__(): ca2. methods will be generated. These compare the class as if it were a tuple of its fields, in order. Both instances in the comparison must be of the identical type. If ‘order’ is true and ‘eq’ is false, a *note ValueError: 1fb. is raised. If the class already defines any of *note __lt__(): c34, *note __le__(): ca0, *note __gt__(): ca1, or *note __ge__(): ca2, then *note TypeError: 192. is raised. - ‘unsafe_hash’: If ‘False’ (the default), a *note __hash__(): 340. method is generated according to how ‘eq’ and ‘frozen’ are set. *note __hash__(): 340. is used by built-in *note hash(): 9c4, and when objects are added to hashed collections such as dictionaries and sets. Having a *note __hash__(): 340. implies that instances of the class are immutable. Mutability is a complicated property that depends on the programmer’s intent, the existence and behavior of *note __eq__(): 33f, and the values of the ‘eq’ and ‘frozen’ flags in the *note dataclass(): 33d. decorator. By default, *note dataclass(): 33d. will not implicitly add a *note __hash__(): 340. method unless it is safe to do so. Neither will it add or change an existing explicitly defined *note __hash__(): 340. method. Setting the class attribute ‘__hash__ = None’ has a specific meaning to Python, as described in the *note __hash__(): 340. documentation. If *note __hash__(): 340. is not explicitly defined, or if it is set to ‘None’, then *note dataclass(): 33d. `may' add an implicit *note __hash__(): 340. method. Although not recommended, you can force *note dataclass(): 33d. to create a *note __hash__(): 340. method with ‘unsafe_hash=True’. This might be the case if your class is logically immutable but can nonetheless be mutated. This is a specialized use case and should be considered carefully. Here are the rules governing implicit creation of a *note __hash__(): 340. method. Note that you cannot both have an explicit *note __hash__(): 340. method in your dataclass and set ‘unsafe_hash=True’; this will result in a *note TypeError: 192. If ‘eq’ and ‘frozen’ are both true, by default *note dataclass(): 33d. will generate a *note __hash__(): 340. method for you. If ‘eq’ is true and ‘frozen’ is false, *note __hash__(): 340. will be set to ‘None’, marking it unhashable (which it is, since it is mutable). If ‘eq’ is false, *note __hash__(): 340. will be left untouched meaning the *note __hash__(): 340. method of the superclass will be used (if the superclass is *note object: 2b0, this means it will fall back to id-based hashing). - ‘frozen’: If true (the default is ‘False’), assigning to fields will generate an exception. This emulates read-only frozen instances. If *note __setattr__(): e2c. or *note __delattr__(): 10d1. is defined in the class, then *note TypeError: 192. is raised. See the discussion below. ‘field’s may optionally specify a default value, using normal Python syntax: @dataclass class C: a: int # 'a' has no default value b: int = 0 # assign a default value for 'b' In this example, both ‘a’ and ‘b’ will be included in the added *note __init__(): d5e. method, which will be defined as: def __init__(self, a: int, b: int = 0): *note TypeError: 192. will be raised if a field without a default value follows a field with a default value. This is true either when this occurs in a single class, or as a result of class inheritance. -- Function: dataclasses.field (*, default=MISSING, default_factory=MISSING, repr=True, hash=None, init=True, compare=True, metadata=None) For common and simple use cases, no other functionality is required. There are, however, some dataclass features that require additional per-field information. To satisfy this need for additional information, you can replace the default field value with a call to the provided *note field(): 338d. function. For example: @dataclass class C: mylist: List[int] = field(default_factory=list) c = C() c.mylist += [1, 2, 3] As shown above, the ‘MISSING’ value is a sentinel object used to detect if the ‘default’ and ‘default_factory’ parameters are provided. This sentinel is used because ‘None’ is a valid value for ‘default’. No code should directly use the ‘MISSING’ value. The parameters to *note field(): 338d. are: - ‘default’: If provided, this will be the default value for this field. This is needed because the *note field(): 338d. call itself replaces the normal position of the default value. - ‘default_factory’: If provided, it must be a zero-argument callable that will be called when a default value is needed for this field. Among other purposes, this can be used to specify fields with mutable default values, as discussed below. It is an error to specify both ‘default’ and ‘default_factory’. - ‘init’: If true (the default), this field is included as a parameter to the generated *note __init__(): d5e. method. - ‘repr’: If true (the default), this field is included in the string returned by the generated *note __repr__(): 33e. method. - ‘compare’: If true (the default), this field is included in the generated equality and comparison methods (*note __eq__(): 33f, *note __gt__(): ca1, et al.). - ‘hash’: This can be a bool or ‘None’. If true, this field is included in the generated *note __hash__(): 340. method. If ‘None’ (the default), use the value of ‘compare’: this would normally be the expected behavior. A field should be considered in the hash if it’s used for comparisons. Setting this value to anything other than ‘None’ is discouraged. One possible reason to set ‘hash=False’ but ‘compare=True’ would be if a field is expensive to compute a hash value for, that field is needed for equality testing, and there are other fields that contribute to the type’s hash value. Even if a field is excluded from the hash, it will still be used for comparisons. - ‘metadata’: This can be a mapping or None. None is treated as an empty dict. This value is wrapped in *note MappingProxyType(): ab6. to make it read-only, and exposed on the *note Field: 338e. object. It is not used at all by Data Classes, and is provided as a third-party extension mechanism. Multiple third-parties can each have their own key, to use as a namespace in the metadata. If the default value of a field is specified by a call to *note field(): 338d, then the class attribute for this field will be replaced by the specified ‘default’ value. If no ‘default’ is provided, then the class attribute will be deleted. The intent is that after the *note dataclass(): 33d. decorator runs, the class attributes will all contain the default values for the fields, just as if the default value itself were specified. For example, after: @dataclass class C: x: int y: int = field(repr=False) z: int = field(repr=False, default=10) t: int = 20 The class attribute ‘C.z’ will be ‘10’, the class attribute ‘C.t’ will be ‘20’, and the class attributes ‘C.x’ and ‘C.y’ will not be set. -- Class: dataclasses.Field *note Field: 338e. objects describe each defined field. These objects are created internally, and are returned by the *note fields(): 338f. module-level method (see below). Users should never instantiate a *note Field: 338e. object directly. Its documented attributes are: - ‘name’: The name of the field. - ‘type’: The type of the field. - ‘default’, ‘default_factory’, ‘init’, ‘repr’, ‘hash’, ‘compare’, and ‘metadata’ have the identical meaning and values as they do in the *note field(): 338d. declaration. Other attributes may exist, but they are private and must not be inspected or relied on. -- Function: dataclasses.fields (class_or_instance) Returns a tuple of *note Field: 338e. objects that define the fields for this dataclass. Accepts either a dataclass, or an instance of a dataclass. Raises *note TypeError: 192. if not passed a dataclass or instance of one. Does not return pseudo-fields which are ‘ClassVar’ or ‘InitVar’. -- Function: dataclasses.asdict (instance, *, dict_factory=dict) Converts the dataclass ‘instance’ to a dict (by using the factory function ‘dict_factory’). Each dataclass is converted to a dict of its fields, as ‘name: value’ pairs. dataclasses, dicts, lists, and tuples are recursed into. For example: @dataclass class Point: x: int y: int @dataclass class C: mylist: List[Point] p = Point(10, 20) assert asdict(p) == {'x': 10, 'y': 20} c = C([Point(0, 0), Point(10, 4)]) assert asdict(c) == {'mylist': [{'x': 0, 'y': 0}, {'x': 10, 'y': 4}]} Raises *note TypeError: 192. if ‘instance’ is not a dataclass instance. -- Function: dataclasses.astuple (instance, *, tuple_factory=tuple) Converts the dataclass ‘instance’ to a tuple (by using the factory function ‘tuple_factory’). Each dataclass is converted to a tuple of its field values. dataclasses, dicts, lists, and tuples are recursed into. Continuing from the previous example: assert astuple(p) == (10, 20) assert astuple(c) == ([(0, 0), (10, 4)],) Raises *note TypeError: 192. if ‘instance’ is not a dataclass instance. -- Function: dataclasses.make_dataclass (cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False) Creates a new dataclass with name ‘cls_name’, fields as defined in ‘fields’, base classes as given in ‘bases’, and initialized with a namespace as given in ‘namespace’. ‘fields’ is an iterable whose elements are each either ‘name’, ‘(name, type)’, or ‘(name, type, Field)’. If just ‘name’ is supplied, ‘typing.Any’ is used for ‘type’. The values of ‘init’, ‘repr’, ‘eq’, ‘order’, ‘unsafe_hash’, and ‘frozen’ have the same meaning as they do in *note dataclass(): 33d. This function is not strictly required, because any Python mechanism for creating a new class with ‘__annotations__’ can then apply the *note dataclass(): 33d. function to convert that class to a dataclass. This function is provided as a convenience. For example: C = make_dataclass('C', [('x', int), 'y', ('z', int, field(default=5))], namespace={'add_one': lambda self: self.x + 1}) Is equivalent to: @dataclass class C: x: int y: 'typing.Any' z: int = 5 def add_one(self): return self.x + 1 -- Function: dataclasses.replace (instance, **changes) Creates a new object of the same type of ‘instance’, replacing fields with values from ‘changes’. If ‘instance’ is not a Data Class, raises *note TypeError: 192. If values in ‘changes’ do not specify fields, raises *note TypeError: 192. The newly returned object is created by calling the *note __init__(): d5e. method of the dataclass. This ensures that ‘__post_init__()’, if present, is also called. Init-only variables without default values, if any exist, must be specified on the call to *note replace(): 3393. so that they can be passed to *note __init__(): d5e. and ‘__post_init__()’. It is an error for ‘changes’ to contain any fields that are defined as having ‘init=False’. A *note ValueError: 1fb. will be raised in this case. Be forewarned about how ‘init=False’ fields work during a call to *note replace(): 3393. They are not copied from the source object, but rather are initialized in ‘__post_init__()’, if they’re initialized at all. It is expected that ‘init=False’ fields will be rarely and judiciously used. If they are used, it might be wise to have alternate class constructors, or perhaps a custom ‘replace()’ (or similarly named) method which handles instance copying. -- Function: dataclasses.is_dataclass (class_or_instance) Return ‘True’ if its parameter is a dataclass or an instance of one, otherwise return ‘False’. If you need to know if a class is an instance of a dataclass (and not a dataclass itself), then add a further check for ‘not isinstance(obj, type)’: def is_dataclass_instance(obj): return is_dataclass(obj) and not isinstance(obj, type)  File: python.info, Node: Post-init processing, Next: Class variables, Prev: Module-level decorators classes and functions, Up: dataclasses — Data Classes 5.29.6.2 Post-init processing ............................. The generated *note __init__(): d5e. code will call a method named ‘__post_init__()’, if ‘__post_init__()’ is defined on the class. It will normally be called as ‘self.__post_init__()’. However, if any ‘InitVar’ fields are defined, they will also be passed to ‘__post_init__()’ in the order they were defined in the class. If no *note __init__(): d5e. method is generated, then ‘__post_init__()’ will not automatically be called. Among other uses, this allows for initializing field values that depend on one or more other fields. For example: @dataclass class C: a: float b: float c: float = field(init=False) def __post_init__(self): self.c = self.a + self.b See the section below on init-only variables for ways to pass parameters to ‘__post_init__()’. Also see the warning about how *note replace(): 3393. handles ‘init=False’ fields.  File: python.info, Node: Class variables, Next: Init-only variables, Prev: Post-init processing, Up: dataclasses — Data Classes 5.29.6.3 Class variables ........................ One of two places where *note dataclass(): 33d. actually inspects the type of a field is to determine if a field is a class variable as defined in PEP 526(1). It does this by checking if the type of the field is ‘typing.ClassVar’. If a field is a ‘ClassVar’, it is excluded from consideration as a field and is ignored by the dataclass mechanisms. Such ‘ClassVar’ pseudo-fields are not returned by the module-level *note fields(): 338f. function. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0526  File: python.info, Node: Init-only variables, Next: Frozen instances, Prev: Class variables, Up: dataclasses — Data Classes 5.29.6.4 Init-only variables ............................ The other place where *note dataclass(): 33d. inspects a type annotation is to determine if a field is an init-only variable. It does this by seeing if the type of a field is of type ‘dataclasses.InitVar’. If a field is an ‘InitVar’, it is considered a pseudo-field called an init-only field. As it is not a true field, it is not returned by the module-level *note fields(): 338f. function. Init-only fields are added as parameters to the generated *note __init__(): d5e. method, and are passed to the optional ‘__post_init__()’ method. They are not otherwise used by dataclasses. For example, suppose a field will be initialized from a database, if a value is not provided when creating the class: @dataclass class C: i: int j: int = None database: InitVar[DatabaseType] = None def __post_init__(self, database): if self.j is None and database is not None: self.j = database.lookup('j') c = C(10, database=my_database) In this case, *note fields(): 338f. will return *note Field: 338e. objects for ‘i’ and ‘j’, but not for ‘database’.  File: python.info, Node: Frozen instances, Next: Inheritance<2>, Prev: Init-only variables, Up: dataclasses — Data Classes 5.29.6.5 Frozen instances ......................... It is not possible to create truly immutable Python objects. However, by passing ‘frozen=True’ to the *note dataclass(): 33d. decorator you can emulate immutability. In that case, dataclasses will add *note __setattr__(): e2c. and *note __delattr__(): 10d1. methods to the class. These methods will raise a *note FrozenInstanceError: 3399. when invoked. There is a tiny performance penalty when using ‘frozen=True’: *note __init__(): d5e. cannot use simple assignment to initialize fields, and must use *note object.__setattr__(): e2c.  File: python.info, Node: Inheritance<2>, Next: Default factory functions, Prev: Frozen instances, Up: dataclasses — Data Classes 5.29.6.6 Inheritance .................... When the dataclass is being created by the *note dataclass(): 33d. decorator, it looks through all of the class’s base classes in reverse MRO (that is, starting at *note object: 2b0.) and, for each dataclass that it finds, adds the fields from that base class to an ordered mapping of fields. After all of the base class fields are added, it adds its own fields to the ordered mapping. All of the generated methods will use this combined, calculated ordered mapping of fields. Because the fields are in insertion order, derived classes override base classes. An example: @dataclass class Base: x: Any = 15.0 y: int = 0 @dataclass class C(Base): z: int = 10 x: int = 15 The final list of fields is, in order, ‘x’, ‘y’, ‘z’. The final type of ‘x’ is ‘int’, as specified in class ‘C’. The generated *note __init__(): d5e. method for ‘C’ will look like: def __init__(self, x: int = 15, y: int = 0, z: int = 10):  File: python.info, Node: Default factory functions, Next: Mutable default values, Prev: Inheritance<2>, Up: dataclasses — Data Classes 5.29.6.7 Default factory functions .................................. If a *note field(): 338d. specifies a ‘default_factory’, it is called with zero arguments when a default value for the field is needed. For example, to create a new instance of a list, use: mylist: list = field(default_factory=list) If a field is excluded from *note __init__(): d5e. (using ‘init=False’) and the field also specifies ‘default_factory’, then the default factory function will always be called from the generated *note __init__(): d5e. function. This happens because there is no other way to give the field an initial value.  File: python.info, Node: Mutable default values, Next: Exceptions<17>, Prev: Default factory functions, Up: dataclasses — Data Classes 5.29.6.8 Mutable default values ............................... Python stores default member variable values in class attributes. Consider this example, not using dataclasses: class C: x = [] def add(self, element): self.x.append(element) o1 = C() o2 = C() o1.add(1) o2.add(2) assert o1.x == [1, 2] assert o1.x is o2.x Note that the two instances of class ‘C’ share the same class variable ‘x’, as expected. Using dataclasses, `if' this code was valid: @dataclass class D: x: List = [] def add(self, element): self.x += element it would generate code similar to: class D: x = [] def __init__(self, x=x): self.x = x def add(self, element): self.x += element assert D().x is D().x This has the same issue as the original example using class ‘C’. That is, two instances of class ‘D’ that do not specify a value for ‘x’ when creating a class instance will share the same copy of ‘x’. Because dataclasses just use normal Python class creation they also share this behavior. There is no general way for Data Classes to detect this condition. Instead, dataclasses will raise a *note TypeError: 192. if it detects a default parameter of type ‘list’, ‘dict’, or ‘set’. This is a partial solution, but it does protect against many common errors. Using default factory functions is a way to create new instances of mutable types as default values for fields: @dataclass class D: x: list = field(default_factory=list) assert D().x is not D().x  File: python.info, Node: Exceptions<17>, Prev: Mutable default values, Up: dataclasses — Data Classes 5.29.6.9 Exceptions ................... -- Exception: dataclasses.FrozenInstanceError Raised when an implicitly defined *note __setattr__(): e2c. or *note __delattr__(): 10d1. is called on a dataclass which was defined with ‘frozen=True’.  File: python.info, Node: contextlib — Utilities for with-statement contexts, Next: abc — Abstract Base Classes, Prev: dataclasses — Data Classes, Up: Python Runtime Services 5.29.7 ‘contextlib’ — Utilities for ‘with’-statement contexts ------------------------------------------------------------- `Source code:' Lib/contextlib.py(1) __________________________________________________________________ This module provides utilities for common tasks involving the *note with: 6e9. statement. For more information see also *note Context Manager Types: 112a. and *note With Statement Context Managers: 1128. * Menu: * Utilities:: * Examples and Recipes: Examples and Recipes<2>. * Single use, reusable and reentrant context managers: Single use reusable and reentrant context managers. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/contextlib.py  File: python.info, Node: Utilities, Next: Examples and Recipes<2>, Up: contextlib — Utilities for with-statement contexts 5.29.7.1 Utilities .................. Functions and classes provided: -- Class: contextlib.AbstractContextManager An *note abstract base class: b33. for classes that implement *note object.__enter__(): c95. and *note object.__exit__(): c96. A default implementation for *note object.__enter__(): c95. is provided which returns ‘self’ while *note object.__exit__(): c96. is an abstract method which by default returns ‘None’. See also the definition of *note Context Manager Types: 112a. New in version 3.6. -- Class: contextlib.AbstractAsyncContextManager An *note abstract base class: b33. for classes that implement *note object.__aenter__(): 113b. and *note object.__aexit__(): 113c. A default implementation for *note object.__aenter__(): 113b. is provided which returns ‘self’ while *note object.__aexit__(): 113c. is an abstract method which by default returns ‘None’. See also the definition of *note Asynchronous Context Managers: 1139. New in version 3.7. -- Function: @contextlib.contextmanager This function is a *note decorator: 283. that can be used to define a factory function for *note with: 6e9. statement context managers, without needing to create a class or separate *note __enter__(): c95. and *note __exit__(): c96. methods. While many objects natively support use in with statements, sometimes a resource needs to be managed that isn’t a context manager in its own right, and doesn’t implement a ‘close()’ method for use with ‘contextlib.closing’ An abstract example would be the following to ensure correct resource management: from contextlib import contextmanager @contextmanager def managed_resource(*args, **kwds): # Code to acquire resource, e.g.: resource = acquire_resource(*args, **kwds) try: yield resource finally: # Code to release resource, e.g.: release_resource(resource) >>> with managed_resource(timeout=3600) as resource: ... # Resource is released at the end of this block, ... # even if code in the block raises an exception The function being decorated must return a *note generator: 9a2.-iterator when called. This iterator must yield exactly one value, which will be bound to the targets in the *note with: 6e9. statement’s ‘as’ clause, if any. At the point where the generator yields, the block nested in the *note with: 6e9. statement is executed. The generator is then resumed after the block is exited. If an unhandled exception occurs in the block, it is reraised inside the generator at the point where the yield occurred. Thus, you can use a *note try: d72.…*note except: b3e.…*note finally: 182. statement to trap the error (if any), or ensure that some cleanup takes place. If an exception is trapped merely in order to log it or to perform some action (rather than to suppress it entirely), the generator must reraise that exception. Otherwise the generator context manager will indicate to the ‘with’ statement that the exception has been handled, and execution will resume with the statement immediately following the ‘with’ statement. *note contextmanager(): b7e. uses *note ContextDecorator: b7d. so the context managers it creates can be used as decorators as well as in *note with: 6e9. statements. When used as a decorator, a new generator instance is implicitly created on each function call (this allows the otherwise “one-shot” context managers created by *note contextmanager(): b7e. to meet the requirement that context managers support multiple invocations in order to be used as decorators). Changed in version 3.2: Use of *note ContextDecorator: b7d. -- Function: @contextlib.asynccontextmanager Similar to *note contextmanager(): b7e, but creates an *note asynchronous context manager: 1139. This function is a *note decorator: 283. that can be used to define a factory function for *note async with: 643. statement asynchronous context managers, without needing to create a class or separate *note __aenter__(): 113b. and *note __aexit__(): 113c. methods. It must be applied to an *note asynchronous generator: 11a9. function. A simple example: from contextlib import asynccontextmanager @asynccontextmanager async def get_connection(): conn = await acquire_db_connection() try: yield conn finally: await release_db_connection(conn) async def get_all_users(): async with get_connection() as conn: return conn.query('SELECT ...') New in version 3.7. -- Function: contextlib.closing (thing) Return a context manager that closes `thing' upon completion of the block. This is basically equivalent to: from contextlib import contextmanager @contextmanager def closing(thing): try: yield thing finally: thing.close() And lets you write code like this: from contextlib import closing from urllib.request import urlopen with closing(urlopen('http://www.python.org')) as page: for line in page: print(line) without needing to explicitly close ‘page’. Even if an error occurs, ‘page.close()’ will be called when the *note with: 6e9. block is exited. -- Function: contextlib.nullcontext (enter_result=None) Return a context manager that returns `enter_result' from ‘__enter__’, but otherwise does nothing. It is intended to be used as a stand-in for an optional context manager, for example: def myfunction(arg, ignore_exceptions=False): if ignore_exceptions: # Use suppress to ignore all exceptions. cm = contextlib.suppress(Exception) else: # Do not ignore any exceptions, cm has no effect. cm = contextlib.nullcontext() with cm: # Do something An example using `enter_result': def process_file(file_or_path): if isinstance(file_or_path, str): # If string, open file cm = open(file_or_path) else: # Caller is responsible for closing file cm = nullcontext(file_or_path) with cm as file: # Perform processing on the file New in version 3.7. -- Function: contextlib.suppress (*exceptions) Return a context manager that suppresses any of the specified exceptions if they occur in the body of a with statement and then resumes execution with the first statement following the end of the with statement. As with any other mechanism that completely suppresses exceptions, this context manager should be used only to cover very specific errors where silently continuing with program execution is known to be the right thing to do. For example: from contextlib import suppress with suppress(FileNotFoundError): os.remove('somefile.tmp') with suppress(FileNotFoundError): os.remove('someotherfile.tmp') This code is equivalent to: try: os.remove('somefile.tmp') except FileNotFoundError: pass try: os.remove('someotherfile.tmp') except FileNotFoundError: pass This context manager is *note reentrant: 33a3. New in version 3.4. -- Function: contextlib.redirect_stdout (new_target) Context manager for temporarily redirecting *note sys.stdout: 30e. to another file or file-like object. This tool adds flexibility to existing functions or classes whose output is hardwired to stdout. For example, the output of *note help(): 572. normally is sent to `sys.stdout'. You can capture that output in a string by redirecting the output to an *note io.StringIO: 82d. object: f = io.StringIO() with redirect_stdout(f): help(pow) s = f.getvalue() To send the output of *note help(): 572. to a file on disk, redirect the output to a regular file: with open('help.txt', 'w') as f: with redirect_stdout(f): help(pow) To send the output of *note help(): 572. to `sys.stderr': with redirect_stdout(sys.stderr): help(pow) Note that the global side effect on *note sys.stdout: 30e. means that this context manager is not suitable for use in library code and most threaded applications. It also has no effect on the output of subprocesses. However, it is still a useful approach for many utility scripts. This context manager is *note reentrant: 33a3. New in version 3.4. -- Function: contextlib.redirect_stderr (new_target) Similar to *note redirect_stdout(): 6c2. but redirecting *note sys.stderr: 30f. to another file or file-like object. This context manager is *note reentrant: 33a3. New in version 3.5. -- Class: contextlib.ContextDecorator A base class that enables a context manager to also be used as a decorator. Context managers inheriting from ‘ContextDecorator’ have to implement ‘__enter__’ and ‘__exit__’ as normal. ‘__exit__’ retains its optional exception handling even when used as a decorator. ‘ContextDecorator’ is used by *note contextmanager(): b7e, so you get this functionality automatically. Example of ‘ContextDecorator’: from contextlib import ContextDecorator class mycontext(ContextDecorator): def __enter__(self): print('Starting') return self def __exit__(self, *exc): print('Finishing') return False >>> @mycontext() ... def function(): ... print('The bit in the middle') ... >>> function() Starting The bit in the middle Finishing >>> with mycontext(): ... print('The bit in the middle') ... Starting The bit in the middle Finishing This change is just syntactic sugar for any construct of the following form: def f(): with cm(): # Do stuff ‘ContextDecorator’ lets you instead write: @cm() def f(): # Do stuff It makes it clear that the ‘cm’ applies to the whole function, rather than just a piece of it (and saving an indentation level is nice, too). Existing context managers that already have a base class can be extended by using ‘ContextDecorator’ as a mixin class: from contextlib import ContextDecorator class mycontext(ContextBaseClass, ContextDecorator): def __enter__(self): return self def __exit__(self, *exc): return False Note: As the decorated function must be able to be called multiple times, the underlying context manager must support use in multiple *note with: 6e9. statements. If this is not the case, then the original construct with the explicit ‘with’ statement inside the function should be used. New in version 3.2. -- Class: contextlib.ExitStack A context manager that is designed to make it easy to programmatically combine other context managers and cleanup functions, especially those that are optional or otherwise driven by input data. For example, a set of files may easily be handled in a single with statement as follows: with ExitStack() as stack: files = [stack.enter_context(open(fname)) for fname in filenames] # All opened files will automatically be closed at the end of # the with statement, even if attempts to open files later # in the list raise an exception Each instance maintains a stack of registered callbacks that are called in reverse order when the instance is closed (either explicitly or implicitly at the end of a *note with: 6e9. statement). Note that callbacks are `not' invoked implicitly when the context stack instance is garbage collected. This stack model is used so that context managers that acquire their resources in their ‘__init__’ method (such as file objects) can be handled correctly. Since registered callbacks are invoked in the reverse order of registration, this ends up behaving as if multiple nested *note with: 6e9. statements had been used with the registered set of callbacks. This even extends to exception handling - if an inner callback suppresses or replaces an exception, then outer callbacks will be passed arguments based on that updated state. This is a relatively low level API that takes care of the details of correctly unwinding the stack of exit callbacks. It provides a suitable foundation for higher level context managers that manipulate the exit stack in application specific ways. New in version 3.3. -- Method: enter_context (cm) Enters a new context manager and adds its *note __exit__(): c96. method to the callback stack. The return value is the result of the context manager’s own *note __enter__(): c95. method. These context managers may suppress exceptions just as they normally would if used directly as part of a *note with: 6e9. statement. -- Method: push (exit) Adds a context manager’s *note __exit__(): c96. method to the callback stack. As ‘__enter__’ is `not' invoked, this method can be used to cover part of an *note __enter__(): c95. implementation with a context manager’s own *note __exit__(): c96. method. If passed an object that is not a context manager, this method assumes it is a callback with the same signature as a context manager’s *note __exit__(): c96. method and adds it directly to the callback stack. By returning true values, these callbacks can suppress exceptions the same way context manager *note __exit__(): c96. methods can. The passed in object is returned from the function, allowing this method to be used as a function decorator. -- Method: callback (callback, *args, **kwds) Accepts an arbitrary callback function and arguments and adds it to the callback stack. Unlike the other methods, callbacks added this way cannot suppress exceptions (as they are never passed the exception details). The passed in callback is returned from the function, allowing this method to be used as a function decorator. -- Method: pop_all () Transfers the callback stack to a fresh *note ExitStack: 376. instance and returns it. No callbacks are invoked by this operation - instead, they will now be invoked when the new stack is closed (either explicitly or implicitly at the end of a *note with: 6e9. statement). For example, a group of files can be opened as an “all or nothing” operation as follows: with ExitStack() as stack: files = [stack.enter_context(open(fname)) for fname in filenames] # Hold onto the close method, but don't call it yet. close_files = stack.pop_all().close # If opening any file fails, all previously opened files will be # closed automatically. If all files are opened successfully, # they will remain open even after the with statement ends. # close_files() can then be invoked explicitly to close them all. -- Method: close () Immediately unwinds the callback stack, invoking callbacks in the reverse order of registration. For any context managers and exit callbacks registered, the arguments passed in will indicate that no exception occurred. -- Class: contextlib.AsyncExitStack An *note asynchronous context manager: 1139, similar to *note ExitStack: 376, that supports combining both synchronous and asynchronous context managers, as well as having coroutines for cleanup logic. The ‘close()’ method is not implemented, *note aclose(): 33a8. must be used instead. -- Method: enter_async_context (cm) Similar to ‘enter_context()’ but expects an asynchronous context manager. -- Method: push_async_exit (exit) Similar to ‘push()’ but expects either an asynchronous context manager or a coroutine function. -- Method: push_async_callback (callback, *args, **kwds) Similar to ‘callback()’ but expects a coroutine function. -- Method: aclose () Similar to ‘close()’ but properly handles awaitables. Continuing the example for *note asynccontextmanager(): 377.: async with AsyncExitStack() as stack: connections = [await stack.enter_async_context(get_connection()) for i in range(5)] # All opened connections will automatically be released at the end of # the async with statement, even if attempts to open a connection # later in the list raise an exception. New in version 3.7.  File: python.info, Node: Examples and Recipes<2>, Next: Single use reusable and reentrant context managers, Prev: Utilities, Up: contextlib — Utilities for with-statement contexts 5.29.7.2 Examples and Recipes ............................. This section describes some examples and recipes for making effective use of the tools provided by *note contextlib: 24. * Menu: * Supporting a variable number of context managers:: * Catching exceptions from __enter__ methods:: * Cleaning up in an __enter__ implementation:: * Replacing any use of try-finally and flag variables:: * Using a context manager as a function decorator::  File: python.info, Node: Supporting a variable number of context managers, Next: Catching exceptions from __enter__ methods, Up: Examples and Recipes<2> 5.29.7.3 Supporting a variable number of context managers ......................................................... The primary use case for *note ExitStack: 376. is the one given in the class documentation: supporting a variable number of context managers and other cleanup operations in a single *note with: 6e9. statement. The variability may come from the number of context managers needed being driven by user input (such as opening a user specified collection of files), or from some of the context managers being optional: with ExitStack() as stack: for resource in resources: stack.enter_context(resource) if need_special_resource(): special = acquire_special_resource() stack.callback(release_special_resource, special) # Perform operations that use the acquired resources As shown, *note ExitStack: 376. also makes it quite easy to use *note with: 6e9. statements to manage arbitrary resources that don’t natively support the context management protocol.  File: python.info, Node: Catching exceptions from __enter__ methods, Next: Cleaning up in an __enter__ implementation, Prev: Supporting a variable number of context managers, Up: Examples and Recipes<2> 5.29.7.4 Catching exceptions from ‘__enter__’ methods ..................................................... It is occasionally desirable to catch exceptions from an ‘__enter__’ method implementation, `without' inadvertently catching exceptions from the *note with: 6e9. statement body or the context manager’s ‘__exit__’ method. By using *note ExitStack: 376. the steps in the context management protocol can be separated slightly in order to allow this: stack = ExitStack() try: x = stack.enter_context(cm) except Exception: # handle __enter__ exception else: with stack: # Handle normal case Actually needing to do this is likely to indicate that the underlying API should be providing a direct resource management interface for use with *note try: d72./*note except: b3e./*note finally: 182. statements, but not all APIs are well designed in that regard. When a context manager is the only resource management API provided, then *note ExitStack: 376. can make it easier to handle various situations that can’t be handled directly in a *note with: 6e9. statement.  File: python.info, Node: Cleaning up in an __enter__ implementation, Next: Replacing any use of try-finally and flag variables, Prev: Catching exceptions from __enter__ methods, Up: Examples and Recipes<2> 5.29.7.5 Cleaning up in an ‘__enter__’ implementation ..................................................... As noted in the documentation of *note ExitStack.push(): 33a5, this method can be useful in cleaning up an already allocated resource if later steps in the *note __enter__(): c95. implementation fail. Here’s an example of doing this for a context manager that accepts resource acquisition and release functions, along with an optional validation function, and maps them to the context management protocol: from contextlib import contextmanager, AbstractContextManager, ExitStack class ResourceManager(AbstractContextManager): def __init__(self, acquire_resource, release_resource, check_resource_ok=None): self.acquire_resource = acquire_resource self.release_resource = release_resource if check_resource_ok is None: def check_resource_ok(resource): return True self.check_resource_ok = check_resource_ok @contextmanager def _cleanup_on_error(self): with ExitStack() as stack: stack.push(self) yield # The validation check passed and didn't raise an exception # Accordingly, we want to keep the resource, and pass it # back to our caller stack.pop_all() def __enter__(self): resource = self.acquire_resource() with self._cleanup_on_error(): if not self.check_resource_ok(resource): msg = "Failed validation for {!r}" raise RuntimeError(msg.format(resource)) return resource def __exit__(self, *exc_details): # We don't need to duplicate any of our resource release logic self.release_resource()  File: python.info, Node: Replacing any use of try-finally and flag variables, Next: Using a context manager as a function decorator, Prev: Cleaning up in an __enter__ implementation, Up: Examples and Recipes<2> 5.29.7.6 Replacing any use of ‘try-finally’ and flag variables .............................................................. A pattern you will sometimes see is a ‘try-finally’ statement with a flag variable to indicate whether or not the body of the ‘finally’ clause should be executed. In its simplest form (that can’t already be handled just by using an ‘except’ clause instead), it looks something like this: cleanup_needed = True try: result = perform_operation() if result: cleanup_needed = False finally: if cleanup_needed: cleanup_resources() As with any ‘try’ statement based code, this can cause problems for development and review, because the setup code and the cleanup code can end up being separated by arbitrarily long sections of code. *note ExitStack: 376. makes it possible to instead register a callback for execution at the end of a ‘with’ statement, and then later decide to skip executing that callback: from contextlib import ExitStack with ExitStack() as stack: stack.callback(cleanup_resources) result = perform_operation() if result: stack.pop_all() This allows the intended cleanup up behaviour to be made explicit up front, rather than requiring a separate flag variable. If a particular application uses this pattern a lot, it can be simplified even further by means of a small helper class: from contextlib import ExitStack class Callback(ExitStack): def __init__(self, callback, /, *args, **kwds): super(Callback, self).__init__() self.callback(callback, *args, **kwds) def cancel(self): self.pop_all() with Callback(cleanup_resources) as cb: result = perform_operation() if result: cb.cancel() If the resource cleanup isn’t already neatly bundled into a standalone function, then it is still possible to use the decorator form of *note ExitStack.callback(): 2a5. to declare the resource cleanup in advance: from contextlib import ExitStack with ExitStack() as stack: @stack.callback def cleanup_resources(): ... result = perform_operation() if result: stack.pop_all() Due to the way the decorator protocol works, a callback function declared this way cannot take any parameters. Instead, any resources to be released must be accessed as closure variables.  File: python.info, Node: Using a context manager as a function decorator, Prev: Replacing any use of try-finally and flag variables, Up: Examples and Recipes<2> 5.29.7.7 Using a context manager as a function decorator ........................................................ *note ContextDecorator: b7d. makes it possible to use a context manager in both an ordinary ‘with’ statement and also as a function decorator. For example, it is sometimes useful to wrap functions or groups of statements with a logger that can track the time of entry and time of exit. Rather than writing both a function decorator and a context manager for the task, inheriting from *note ContextDecorator: b7d. provides both capabilities in a single definition: from contextlib import ContextDecorator import logging logging.basicConfig(level=logging.INFO) class track_entry_and_exit(ContextDecorator): def __init__(self, name): self.name = name def __enter__(self): logging.info('Entering: %s', self.name) def __exit__(self, exc_type, exc, exc_tb): logging.info('Exiting: %s', self.name) Instances of this class can be used as both a context manager: with track_entry_and_exit('widget loader'): print('Some time consuming activity goes here') load_widget() And also as a function decorator: @track_entry_and_exit('widget loader') def activity(): print('Some time consuming activity goes here') load_widget() Note that there is one additional limitation when using context managers as function decorators: there’s no way to access the return value of *note __enter__(): c95. If that value is needed, then it is still necessary to use an explicit ‘with’ statement. See also ........ PEP 343(1) - The “with” statement The specification, background, and examples for the Python *note with: 6e9. statement. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0343  File: python.info, Node: Single use reusable and reentrant context managers, Prev: Examples and Recipes<2>, Up: contextlib — Utilities for with-statement contexts 5.29.7.8 Single use, reusable and reentrant context managers ............................................................ Most context managers are written in a way that means they can only be used effectively in a *note with: 6e9. statement once. These single use context managers must be created afresh each time they’re used - attempting to use them a second time will trigger an exception or otherwise not work correctly. This common limitation means that it is generally advisable to create context managers directly in the header of the *note with: 6e9. statement where they are used (as shown in all of the usage examples above). Files are an example of effectively single use context managers, since the first *note with: 6e9. statement will close the file, preventing any further IO operations using that file object. Context managers created using *note contextmanager(): b7e. are also single use context managers, and will complain about the underlying generator failing to yield if an attempt is made to use them a second time: >>> from contextlib import contextmanager >>> @contextmanager ... def singleuse(): ... print("Before") ... yield ... print("After") ... >>> cm = singleuse() >>> with cm: ... pass ... Before After >>> with cm: ... pass ... Traceback (most recent call last): ... RuntimeError: generator didn't yield * Menu: * Reentrant context managers:: * Reusable context managers::  File: python.info, Node: Reentrant context managers, Next: Reusable context managers, Up: Single use reusable and reentrant context managers 5.29.7.9 Reentrant context managers ................................... More sophisticated context managers may be “reentrant”. These context managers can not only be used in multiple *note with: 6e9. statements, but may also be used `inside' a ‘with’ statement that is already using the same context manager. *note threading.RLock: bef. is an example of a reentrant context manager, as are *note suppress(): 82c. and *note redirect_stdout(): 6c2. Here’s a very simple example of reentrant use: >>> from contextlib import redirect_stdout >>> from io import StringIO >>> stream = StringIO() >>> write_to_stream = redirect_stdout(stream) >>> with write_to_stream: ... print("This is written to the stream rather than stdout") ... with write_to_stream: ... print("This is also written to the stream") ... >>> print("This is written directly to stdout") This is written directly to stdout >>> print(stream.getvalue()) This is written to the stream rather than stdout This is also written to the stream Real world examples of reentrancy are more likely to involve multiple functions calling each other and hence be far more complicated than this example. Note also that being reentrant is `not' the same thing as being thread safe. *note redirect_stdout(): 6c2, for example, is definitely not thread safe, as it makes a global modification to the system state by binding *note sys.stdout: 30e. to a different stream.  File: python.info, Node: Reusable context managers, Prev: Reentrant context managers, Up: Single use reusable and reentrant context managers 5.29.7.10 Reusable context managers ................................... Distinct from both single use and reentrant context managers are “reusable” context managers (or, to be completely explicit, “reusable, but not reentrant” context managers, since reentrant context managers are also reusable). These context managers support being used multiple times, but will fail (or otherwise not work correctly) if the specific context manager instance has already been used in a containing with statement. *note threading.Lock: 2050. is an example of a reusable, but not reentrant, context manager (for a reentrant lock, it is necessary to use *note threading.RLock: bef. instead). Another example of a reusable, but not reentrant, context manager is *note ExitStack: 376, as it invokes `all' currently registered callbacks when leaving any with statement, regardless of where those callbacks were added: >>> from contextlib import ExitStack >>> stack = ExitStack() >>> with stack: ... stack.callback(print, "Callback: from first context") ... print("Leaving first context") ... Leaving first context Callback: from first context >>> with stack: ... stack.callback(print, "Callback: from second context") ... print("Leaving second context") ... Leaving second context Callback: from second context >>> with stack: ... stack.callback(print, "Callback: from outer context") ... with stack: ... stack.callback(print, "Callback: from inner context") ... print("Leaving inner context") ... print("Leaving outer context") ... Leaving inner context Callback: from inner context Callback: from outer context Leaving outer context As the output from the example shows, reusing a single stack object across multiple with statements works correctly, but attempting to nest them will cause the stack to be cleared at the end of the innermost with statement, which is unlikely to be desirable behaviour. Using separate *note ExitStack: 376. instances instead of reusing a single instance avoids that problem: >>> from contextlib import ExitStack >>> with ExitStack() as outer_stack: ... outer_stack.callback(print, "Callback: from outer context") ... with ExitStack() as inner_stack: ... inner_stack.callback(print, "Callback: from inner context") ... print("Leaving inner context") ... print("Leaving outer context") ... Leaving inner context Callback: from inner context Leaving outer context Callback: from outer context  File: python.info, Node: abc — Abstract Base Classes, Next: atexit — Exit handlers, Prev: contextlib — Utilities for with-statement contexts, Up: Python Runtime Services 5.29.8 ‘abc’ — Abstract Base Classes ------------------------------------ `Source code:' Lib/abc.py(1) __________________________________________________________________ This module provides the infrastructure for defining *note abstract base classes: b33. (ABCs) in Python, as outlined in PEP 3119(2); see the PEP for why this was added to Python. (See also PEP 3141(3) and the *note numbers: c1. module regarding a type hierarchy for numbers based on ABCs.) The *note collections: 1e. module has some concrete classes that derive from ABCs; these can, of course, be further derived. In addition, the *note collections.abc: 1f. submodule has some ABCs that can be used to test whether a class or instance provides a particular interface, for example, if it is hashable or if it is a mapping. This module provides the metaclass *note ABCMeta: 819. for defining ABCs and a helper class *note ABC: 818. to alternatively define ABCs through inheritance: -- Class: abc.ABC A helper class that has *note ABCMeta: 819. as its metaclass. With this class, an abstract base class can be created by simply deriving from *note ABC: 818. avoiding sometimes confusing metaclass usage, for example: from abc import ABC class MyABC(ABC): pass Note that the type of *note ABC: 818. is still *note ABCMeta: 819, therefore inheriting from *note ABC: 818. requires the usual precautions regarding metaclass usage, as multiple inheritance may lead to metaclass conflicts. One may also define an abstract base class by passing the metaclass keyword and using *note ABCMeta: 819. directly, for example: from abc import ABCMeta class MyABC(metaclass=ABCMeta): pass New in version 3.4. -- Class: abc.ABCMeta Metaclass for defining Abstract Base Classes (ABCs). Use this metaclass to create an ABC. An ABC can be subclassed directly, and then acts as a mix-in class. You can also register unrelated concrete classes (even built-in classes) and unrelated ABCs as “virtual subclasses” – these and their descendants will be considered subclasses of the registering ABC by the built-in *note issubclass(): 450. function, but the registering ABC won’t show up in their MRO (Method Resolution Order) nor will method implementations defined by the registering ABC be callable (not even via *note super(): 4e2.). (4) Classes created with a metaclass of *note ABCMeta: 819. have the following method: -- Method: register (subclass) Register `subclass' as a “virtual subclass” of this ABC. For example: from abc import ABC class MyABC(ABC): pass MyABC.register(tuple) assert issubclass(tuple, MyABC) assert isinstance((), MyABC) Changed in version 3.3: Returns the registered subclass, to allow usage as a class decorator. Changed in version 3.4: To detect calls to *note register(): 9d1, you can use the *note get_cache_token(): 817. function. You can also override this method in an abstract base class: -- Method: __subclasshook__ (subclass) (Must be defined as a class method.) Check whether `subclass' is considered a subclass of this ABC. This means that you can customize the behavior of ‘issubclass’ further without the need to call *note register(): 9d1. on every class you want to consider a subclass of the ABC. (This class method is called from the ‘__subclasscheck__()’ method of the ABC.) This method should return ‘True’, ‘False’ or ‘NotImplemented’. If it returns ‘True’, the `subclass' is considered a subclass of this ABC. If it returns ‘False’, the `subclass' is not considered a subclass of this ABC, even if it would normally be one. If it returns ‘NotImplemented’, the subclass check is continued with the usual mechanism. For a demonstration of these concepts, look at this example ABC definition: class Foo: def __getitem__(self, index): ... def __len__(self): ... def get_iterator(self): return iter(self) class MyIterable(ABC): @abstractmethod def __iter__(self): while False: yield None def get_iterator(self): return self.__iter__() @classmethod def __subclasshook__(cls, C): if cls is MyIterable: if any("__iter__" in B.__dict__ for B in C.__mro__): return True return NotImplemented MyIterable.register(Foo) The ABC ‘MyIterable’ defines the standard iterable method, *note __iter__(): 12d5, as an abstract method. The implementation given here can still be called from subclasses. The ‘get_iterator()’ method is also part of the ‘MyIterable’ abstract base class, but it does not have to be overridden in non-abstract derived classes. The *note __subclasshook__(): 33b7. class method defined here says that any class that has an *note __iter__(): 12d5. method in its *note __dict__: 4fc. (or in that of one of its base classes, accessed via the *note __mro__: 12af. list) is considered a ‘MyIterable’ too. Finally, the last line makes ‘Foo’ a virtual subclass of ‘MyIterable’, even though it does not define an *note __iter__(): 12d5. method (it uses the old-style iterable protocol, defined in terms of *note __len__(): dcb. and *note __getitem__(): 27c.). Note that this will not make ‘get_iterator’ available as a method of ‘Foo’, so it is provided separately. The *note abc: 4. module also provides the following decorator: -- Function: @abc.abstractmethod A decorator indicating abstract methods. Using this decorator requires that the class’s metaclass is *note ABCMeta: 819. or is derived from it. A class that has a metaclass derived from *note ABCMeta: 819. cannot be instantiated unless all of its abstract methods and properties are overridden. The abstract methods can be called using any of the normal ‘super’ call mechanisms. *note abstractmethod(): 9ce. may be used to declare abstract methods for properties and descriptors. Dynamically adding abstract methods to a class, or attempting to modify the abstraction status of a method or class once it is created, are not supported. The *note abstractmethod(): 9ce. only affects subclasses derived using regular inheritance; “virtual subclasses” registered with the ABC’s ‘register()’ method are not affected. When *note abstractmethod(): 9ce. is applied in combination with other method descriptors, it should be applied as the innermost decorator, as shown in the following usage examples: class C(ABC): @abstractmethod def my_abstract_method(self, ...): ... @classmethod @abstractmethod def my_abstract_classmethod(cls, ...): ... @staticmethod @abstractmethod def my_abstract_staticmethod(...): ... @property @abstractmethod def my_abstract_property(self): ... @my_abstract_property.setter @abstractmethod def my_abstract_property(self, val): ... @abstractmethod def _get_x(self): ... @abstractmethod def _set_x(self, val): ... x = property(_get_x, _set_x) In order to correctly interoperate with the abstract base class machinery, the descriptor must identify itself as abstract using ‘__isabstractmethod__’. In general, this attribute should be ‘True’ if any of the methods used to compose the descriptor are abstract. For example, Python’s built-in *note property: 1d7. does the equivalent of: class Descriptor: ... @property def __isabstractmethod__(self): return any(getattr(f, '__isabstractmethod__', False) for f in (self._fget, self._fset, self._fdel)) Note: Unlike Java abstract methods, these abstract methods may have an implementation. This implementation can be called via the *note super(): 4e2. mechanism from the class that overrides it. This could be useful as an end-point for a super-call in a framework that uses cooperative multiple-inheritance. The *note abc: 4. module also supports the following legacy decorators: -- Function: @abc.abstractclassmethod New in version 3.2. Deprecated since version 3.3: It is now possible to use *note classmethod: 1d8. with *note abstractmethod(): 9ce, making this decorator redundant. A subclass of the built-in *note classmethod(): 1d8, indicating an abstract classmethod. Otherwise it is similar to *note abstractmethod(): 9ce. This special case is deprecated, as the *note classmethod(): 1d8. decorator is now correctly identified as abstract when applied to an abstract method: class C(ABC): @classmethod @abstractmethod def my_abstract_classmethod(cls, ...): ... -- Function: @abc.abstractstaticmethod New in version 3.2. Deprecated since version 3.3: It is now possible to use *note staticmethod: 1d9. with *note abstractmethod(): 9ce, making this decorator redundant. A subclass of the built-in *note staticmethod(): 1d9, indicating an abstract staticmethod. Otherwise it is similar to *note abstractmethod(): 9ce. This special case is deprecated, as the *note staticmethod(): 1d9. decorator is now correctly identified as abstract when applied to an abstract method: class C(ABC): @staticmethod @abstractmethod def my_abstract_staticmethod(...): ... -- Function: @abc.abstractproperty Deprecated since version 3.3: It is now possible to use *note property: 1d7, ‘property.getter()’, ‘property.setter()’ and ‘property.deleter()’ with *note abstractmethod(): 9ce, making this decorator redundant. A subclass of the built-in *note property(): 1d7, indicating an abstract property. This special case is deprecated, as the *note property(): 1d7. decorator is now correctly identified as abstract when applied to an abstract method: class C(ABC): @property @abstractmethod def my_abstract_property(self): ... The above example defines a read-only property; you can also define a read-write abstract property by appropriately marking one or more of the underlying methods as abstract: class C(ABC): @property def x(self): ... @x.setter @abstractmethod def x(self, val): ... If only some components are abstract, only those components need to be updated to create a concrete property in a subclass: class D(C): @C.x.setter def x(self, val): ... The *note abc: 4. module also provides the following functions: -- Function: abc.get_cache_token () Returns the current abstract base class cache token. The token is an opaque object (that supports equality testing) identifying the current version of the abstract base class cache for virtual subclasses. The token changes with every call to *note ABCMeta.register(): 9d1. on any ABC. New in version 3.4. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/abc.py (2) https://www.python.org/dev/peps/pep-3119 (3) https://www.python.org/dev/peps/pep-3141 (4) (1) C++ programmers should note that Python’s virtual base class concept is not the same as C++’s.  File: python.info, Node: atexit — Exit handlers, Next: traceback — Print or retrieve a stack traceback, Prev: abc — Abstract Base Classes, Up: Python Runtime Services 5.29.9 ‘atexit’ — Exit handlers ------------------------------- __________________________________________________________________ The *note atexit: c. module defines functions to register and unregister cleanup functions. Functions thus registered are automatically executed upon normal interpreter termination. *note atexit: c. runs these functions in the `reverse' order in which they were registered; if you register ‘A’, ‘B’, and ‘C’, at interpreter termination time they will be run in the order ‘C’, ‘B’, ‘A’. `Note:' The functions registered via this module are not called when the program is killed by a signal not handled by Python, when a Python fatal internal error is detected, or when *note os._exit(): 13b6. is called. Changed in version 3.7: When used with C-API subinterpreters, registered functions are local to the interpreter they were registered in. -- Function: atexit.register (func, *args, **kwargs) Register `func' as a function to be executed at termination. Any optional arguments that are to be passed to `func' must be passed as arguments to *note register(): e85. It is possible to register the same function and arguments more than once. At normal program termination (for instance, if *note sys.exit(): ce2. is called or the main module’s execution completes), all functions registered are called in last in, first out order. The assumption is that lower level modules will normally be imported before higher level modules and thus must be cleaned up later. If an exception is raised during execution of the exit handlers, a traceback is printed (unless *note SystemExit: 5fc. is raised) and the exception information is saved. After all exit handlers have had a chance to run the last exception to be raised is re-raised. This function returns `func', which makes it possible to use it as a decorator. -- Function: atexit.unregister (func) Remove `func' from the list of functions to be run at interpreter shutdown. After calling *note unregister(): 33ba, `func' is guaranteed not to be called when the interpreter shuts down, even if it was registered more than once. *note unregister(): 33ba. silently does nothing if `func' was not previously registered. See also ........ Module *note readline: de. Useful example of *note atexit: c. to read and write *note readline: de. history files. * Menu: * atexit Example::  File: python.info, Node: atexit Example, Up: atexit — Exit handlers 5.29.9.1 ‘atexit’ Example ......................... The following simple example demonstrates how a module can initialize a counter from a file when it is imported and save the counter’s updated value automatically when the program terminates without relying on the application making an explicit call into this module at termination. try: with open("counterfile") as infile: _count = int(infile.read()) except FileNotFoundError: _count = 0 def incrcounter(n): global _count _count = _count + n def savecounter(): with open("counterfile", "w") as outfile: outfile.write("%d" % _count) import atexit atexit.register(savecounter) Positional and keyword arguments may also be passed to *note register(): e85. to be passed along to the registered function when it is called: def goodbye(name, adjective): print('Goodbye, %s, it was %s to meet you.' % (name, adjective)) import atexit atexit.register(goodbye, 'Donny', 'nice') # or: atexit.register(goodbye, adjective='nice', name='Donny') Usage as a *note decorator: 283.: import atexit @atexit.register def goodbye(): print("You are now leaving the Python sector.") This only works with functions that can be called without arguments.  File: python.info, Node: traceback — Print or retrieve a stack traceback, Next: __future__ — Future statement definitions, Prev: atexit — Exit handlers, Up: Python Runtime Services 5.29.10 ‘traceback’ — Print or retrieve a stack traceback --------------------------------------------------------- `Source code:' Lib/traceback.py(1) __________________________________________________________________ This module provides a standard interface to extract, format and print stack traces of Python programs. It exactly mimics the behavior of the Python interpreter when it prints a stack trace. This is useful when you want to print stack traces under program control, such as in a “wrapper” around the interpreter. The module uses traceback objects — this is the object type that is stored in the *note sys.last_traceback: 325a. variable and returned as the third item from *note sys.exc_info(): c5f. The module defines the following functions: -- Function: traceback.print_tb (tb, limit=None, file=None) Print up to `limit' stack trace entries from traceback object `tb' (starting from the caller’s frame) if `limit' is positive. Otherwise, print the last ‘abs(limit)’ entries. If `limit' is omitted or ‘None’, all entries are printed. If `file' is omitted or ‘None’, the output goes to ‘sys.stderr’; otherwise it should be an open file or file-like object to receive the output. Changed in version 3.5: Added negative `limit' support. -- Function: traceback.print_exception (etype, value, tb, limit=None, file=None, chain=True) Print exception information and stack trace entries from traceback object `tb' to `file'. This differs from *note print_tb(): 779. in the following ways: * if `tb' is not ‘None’, it prints a header ‘Traceback (most recent call last):’ * it prints the exception `etype' and `value' after the stack trace * if `type(value)' is *note SyntaxError: 458. and `value' has the appropriate format, it prints the line where the syntax error occurred with a caret indicating the approximate position of the error. The optional `limit' argument has the same meaning as for *note print_tb(): 779. If `chain' is true (the default), then chained exceptions (the ‘__cause__’ or ‘__context__’ attributes of the exception) will be printed as well, like the interpreter itself does when printing an unhandled exception. Changed in version 3.5: The `etype' argument is ignored and inferred from the type of `value'. -- Function: traceback.print_exc (limit=None, file=None, chain=True) This is a shorthand for ‘print_exception(*sys.exc_info(), limit, file, chain)’. -- Function: traceback.print_last (limit=None, file=None, chain=True) This is a shorthand for ‘print_exception(sys.last_type, sys.last_value, sys.last_traceback, limit, file, chain)’. In general it will work only after an exception has reached an interactive prompt (see *note sys.last_type: c5a.). -- Function: traceback.print_stack (f=None, limit=None, file=None) Print up to `limit' stack trace entries (starting from the invocation point) if `limit' is positive. Otherwise, print the last ‘abs(limit)’ entries. If `limit' is omitted or ‘None’, all entries are printed. The optional `f' argument can be used to specify an alternate stack frame to start. The optional `file' argument has the same meaning as for *note print_tb(): 779. Changed in version 3.5: Added negative `limit' support. -- Function: traceback.extract_tb (tb, limit=None) Return a *note StackSummary: 777. object representing a list of “pre-processed” stack trace entries extracted from the traceback object `tb'. It is useful for alternate formatting of stack traces. The optional `limit' argument has the same meaning as for *note print_tb(): 779. A “pre-processed” stack trace entry is a *note FrameSummary: 778. object containing attributes ‘filename’, ‘lineno’, ‘name’, and ‘line’ representing the information that is usually printed for a stack trace. The ‘line’ is a string with leading and trailing whitespace stripped; if the source is not available it is ‘None’. -- Function: traceback.extract_stack (f=None, limit=None) Extract the raw traceback from the current stack frame. The return value has the same format as for *note extract_tb(): 33c1. The optional `f' and `limit' arguments have the same meaning as for *note print_stack(): 77a. -- Function: traceback.format_list (extracted_list) Given a list of tuples or *note FrameSummary: 778. objects as returned by *note extract_tb(): 33c1. or *note extract_stack(): 33c2, return a list of strings ready for printing. Each string in the resulting list corresponds to the item with the same index in the argument list. Each string ends in a newline; the strings may contain internal newlines as well, for those items whose source text line is not ‘None’. -- Function: traceback.format_exception_only (etype, value) Format the exception part of a traceback. The arguments are the exception type and value such as given by ‘sys.last_type’ and ‘sys.last_value’. The return value is a list of strings, each ending in a newline. Normally, the list contains a single string; however, for *note SyntaxError: 458. exceptions, it contains several lines that (when printed) display detailed information about where the syntax error occurred. The message indicating which exception occurred is the always last string in the list. -- Function: traceback.format_exception (etype, value, tb, limit=None, chain=True) Format a stack trace and the exception information. The arguments have the same meaning as the corresponding arguments to *note print_exception(): 1d8b. The return value is a list of strings, each ending in a newline and some containing internal newlines. When these lines are concatenated and printed, exactly the same text is printed as does *note print_exception(): 1d8b. Changed in version 3.5: The `etype' argument is ignored and inferred from the type of `value'. -- Function: traceback.format_exc (limit=None, chain=True) This is like ‘print_exc(limit)’ but returns a string instead of printing to a file. -- Function: traceback.format_tb (tb, limit=None) A shorthand for ‘format_list(extract_tb(tb, limit))’. -- Function: traceback.format_stack (f=None, limit=None) A shorthand for ‘format_list(extract_stack(f, limit))’. -- Function: traceback.clear_frames (tb) Clears the local variables of all the stack frames in a traceback `tb' by calling the ‘clear()’ method of each frame object. New in version 3.4. -- Function: traceback.walk_stack (f) Walk a stack following ‘f.f_back’ from the given frame, yielding the frame and line number for each frame. If `f' is ‘None’, the current stack is used. This helper is used with *note StackSummary.extract(): 33c7. New in version 3.5. -- Function: traceback.walk_tb (tb) Walk a traceback following ‘tb_next’ yielding the frame and line number for each frame. This helper is used with *note StackSummary.extract(): 33c7. New in version 3.5. The module also defines the following classes: * Menu: * TracebackException Objects:: * StackSummary Objects:: * FrameSummary Objects:: * Traceback Examples:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/traceback.py  File: python.info, Node: TracebackException Objects, Next: StackSummary Objects, Up: traceback — Print or retrieve a stack traceback 5.29.10.1 ‘TracebackException’ Objects ...................................... New in version 3.5. *note TracebackException: 776. objects are created from actual exceptions to capture data for later printing in a lightweight fashion. -- Class: traceback.TracebackException (exc_type, exc_value, exc_traceback, *, limit=None, lookup_lines=True, capture_locals=False) Capture an exception for later rendering. `limit', `lookup_lines' and `capture_locals' are as for the *note StackSummary: 777. class. Note that when locals are captured, they are also shown in the traceback. -- Attribute: __cause__ A *note TracebackException: 776. of the original ‘__cause__’. -- Attribute: __context__ A *note TracebackException: 776. of the original ‘__context__’. -- Attribute: __suppress_context__ The ‘__suppress_context__’ value from the original exception. -- Attribute: stack A *note StackSummary: 777. representing the traceback. -- Attribute: exc_type The class of the original traceback. -- Attribute: filename For syntax errors - the file name where the error occurred. -- Attribute: lineno For syntax errors - the line number where the error occurred. -- Attribute: text For syntax errors - the text where the error occurred. -- Attribute: offset For syntax errors - the offset into the text where the error occurred. -- Attribute: msg For syntax errors - the compiler error message. -- Method: classmethod from_exception (exc, *, limit=None, lookup_lines=True, capture_locals=False) Capture an exception for later rendering. `limit', `lookup_lines' and `capture_locals' are as for the *note StackSummary: 777. class. Note that when locals are captured, they are also shown in the traceback. -- Method: format (*, chain=True) Format the exception. If `chain' is not ‘True’, ‘__cause__’ and ‘__context__’ will not be formatted. The return value is a generator of strings, each ending in a newline and some containing internal newlines. *note print_exception(): 1d8b. is a wrapper around this method which just prints the lines to a file. The message indicating which exception occurred is always the last string in the output. -- Method: format_exception_only () Format the exception part of the traceback. The return value is a generator of strings, each ending in a newline. Normally, the generator emits a single string; however, for *note SyntaxError: 458. exceptions, it emits several lines that (when printed) display detailed information about where the syntax error occurred. The message indicating which exception occurred is always the last string in the output.  File: python.info, Node: StackSummary Objects, Next: FrameSummary Objects, Prev: TracebackException Objects, Up: traceback — Print or retrieve a stack traceback 5.29.10.2 ‘StackSummary’ Objects ................................ New in version 3.5. *note StackSummary: 777. objects represent a call stack ready for formatting. -- Class: traceback.StackSummary -- Method: classmethod extract (frame_gen, *, limit=None, lookup_lines=True, capture_locals=False) Construct a *note StackSummary: 777. object from a frame generator (such as is returned by *note walk_stack(): 774. or *note walk_tb(): 775.). If `limit' is supplied, only this many frames are taken from `frame_gen'. If `lookup_lines' is ‘False’, the returned *note FrameSummary: 778. objects will not have read their lines in yet, making the cost of creating the *note StackSummary: 777. cheaper (which may be valuable if it may not actually get formatted). If `capture_locals' is ‘True’ the local variables in each *note FrameSummary: 778. are captured as object representations. -- Method: classmethod from_list (a_list) Construct a *note StackSummary: 777. object from a supplied list of *note FrameSummary: 778. objects or old-style list of tuples. Each tuple should be a 4-tuple with filename, lineno, name, line as the elements. -- Method: format () Returns a list of strings ready for printing. Each string in the resulting list corresponds to a single frame from the stack. Each string ends in a newline; the strings may contain internal newlines as well, for those items with source text lines. For long sequences of the same frame and line, the first few repetitions are shown, followed by a summary line stating the exact number of further repetitions. Changed in version 3.6: Long sequences of repeated frames are now abbreviated.  File: python.info, Node: FrameSummary Objects, Next: Traceback Examples, Prev: StackSummary Objects, Up: traceback — Print or retrieve a stack traceback 5.29.10.3 ‘FrameSummary’ Objects ................................ New in version 3.5. *note FrameSummary: 778. objects represent a single frame in a traceback. -- Class: traceback.FrameSummary (filename, lineno, name, lookup_line=True, locals=None, line=None) Represent a single frame in the traceback or stack that is being formatted or printed. It may optionally have a stringified version of the frames locals included in it. If `lookup_line' is ‘False’, the source code is not looked up until the *note FrameSummary: 778. has the ‘line’ attribute accessed (which also happens when casting it to a tuple). ‘line’ may be directly provided, and will prevent line lookups happening at all. `locals' is an optional local variable dictionary, and if supplied the variable representations are stored in the summary for later display.  File: python.info, Node: Traceback Examples, Prev: FrameSummary Objects, Up: traceback — Print or retrieve a stack traceback 5.29.10.4 Traceback Examples ............................ This simple example implements a basic read-eval-print loop, similar to (but less useful than) the standard Python interactive interpreter loop. For a more complete implementation of the interpreter loop, refer to the *note code: 1b. module. import sys, traceback def run_user_code(envdir): source = input(">>> ") try: exec(source, envdir) except Exception: print("Exception in user code:") print("-"*60) traceback.print_exc(file=sys.stdout) print("-"*60) envdir = {} while True: run_user_code(envdir) The following example demonstrates the different ways to print and format the exception and traceback: import sys, traceback def lumberjack(): bright_side_of_death() def bright_side_of_death(): return tuple()[0] try: lumberjack() except IndexError: exc_type, exc_value, exc_traceback = sys.exc_info() print("*** print_tb:") traceback.print_tb(exc_traceback, limit=1, file=sys.stdout) print("*** print_exception:") # exc_type below is ignored on 3.5 and later traceback.print_exception(exc_type, exc_value, exc_traceback, limit=2, file=sys.stdout) print("*** print_exc:") traceback.print_exc(limit=2, file=sys.stdout) print("*** format_exc, first and last line:") formatted_lines = traceback.format_exc().splitlines() print(formatted_lines[0]) print(formatted_lines[-1]) print("*** format_exception:") # exc_type below is ignored on 3.5 and later print(repr(traceback.format_exception(exc_type, exc_value, exc_traceback))) print("*** extract_tb:") print(repr(traceback.extract_tb(exc_traceback))) print("*** format_tb:") print(repr(traceback.format_tb(exc_traceback))) print("*** tb_lineno:", exc_traceback.tb_lineno) The output for the example would look similar to this: *** print_tb: File "<doctest...>", line 10, in <module> lumberjack() *** print_exception: Traceback (most recent call last): File "<doctest...>", line 10, in <module> lumberjack() File "<doctest...>", line 4, in lumberjack bright_side_of_death() IndexError: tuple index out of range *** print_exc: Traceback (most recent call last): File "<doctest...>", line 10, in <module> lumberjack() File "<doctest...>", line 4, in lumberjack bright_side_of_death() IndexError: tuple index out of range *** format_exc, first and last line: Traceback (most recent call last): IndexError: tuple index out of range *** format_exception: ['Traceback (most recent call last):\n', ' File "<doctest...>", line 10, in <module>\n lumberjack()\n', ' File "<doctest...>", line 4, in lumberjack\n bright_side_of_death()\n', ' File "<doctest...>", line 7, in bright_side_of_death\n return tuple()[0]\n', 'IndexError: tuple index out of range\n'] *** extract_tb: [<FrameSummary file <doctest...>, line 10 in <module>>, <FrameSummary file <doctest...>, line 4 in lumberjack>, <FrameSummary file <doctest...>, line 7 in bright_side_of_death>] *** format_tb: [' File "<doctest...>", line 10, in <module>\n lumberjack()\n', ' File "<doctest...>", line 4, in lumberjack\n bright_side_of_death()\n', ' File "<doctest...>", line 7, in bright_side_of_death\n return tuple()[0]\n'] *** tb_lineno: 10 The following example shows the different ways to print and format the stack: >>> import traceback >>> def another_function(): ... lumberstack() ... >>> def lumberstack(): ... traceback.print_stack() ... print(repr(traceback.extract_stack())) ... print(repr(traceback.format_stack())) ... >>> another_function() File "<doctest>", line 10, in <module> another_function() File "<doctest>", line 3, in another_function lumberstack() File "<doctest>", line 6, in lumberstack traceback.print_stack() [('<doctest>', 10, '<module>', 'another_function()'), ('<doctest>', 3, 'another_function', 'lumberstack()'), ('<doctest>', 7, 'lumberstack', 'print(repr(traceback.extract_stack()))')] [' File "<doctest>", line 10, in <module>\n another_function()\n', ' File "<doctest>", line 3, in another_function\n lumberstack()\n', ' File "<doctest>", line 8, in lumberstack\n print(repr(traceback.format_stack()))\n'] This last example demonstrates the final few formatting functions: >>> import traceback >>> traceback.format_list([('spam.py', 3, '<module>', 'spam.eggs()'), ... ('eggs.py', 42, 'eggs', 'return "bacon"')]) [' File "spam.py", line 3, in <module>\n spam.eggs()\n', ' File "eggs.py", line 42, in eggs\n return "bacon"\n'] >>> an_error = IndexError('tuple index out of range') >>> traceback.format_exception_only(type(an_error), an_error) ['IndexError: tuple index out of range\n']  File: python.info, Node: __future__ — Future statement definitions, Next: gc — Garbage Collector interface, Prev: traceback — Print or retrieve a stack traceback, Up: Python Runtime Services 5.29.11 ‘__future__’ — Future statement definitions --------------------------------------------------- `Source code:' Lib/__future__.py(1) __________________________________________________________________ *note __future__: 0. is a real module, and serves three purposes: * To avoid confusing existing tools that analyze import statements and expect to find the modules they’re importing. * To ensure that *note future statements: 1236. run under releases prior to 2.1 at least yield runtime exceptions (the import of *note __future__: 0. will fail, because there was no module of that name prior to 2.1). * To document when incompatible changes were introduced, and when they will be — or were — made mandatory. This is a form of executable documentation, and can be inspected programmatically via importing *note __future__: 0. and examining its contents. Each statement in ‘__future__.py’ is of the form: FeatureName = _Feature(OptionalRelease, MandatoryRelease, CompilerFlag) where, normally, `OptionalRelease' is less than `MandatoryRelease', and both are 5-tuples of the same form as *note sys.version_info: b1a.: (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int PY_MINOR_VERSION, # the 1; an int PY_MICRO_VERSION, # the 0; an int PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string PY_RELEASE_SERIAL # the 3; an int ) `OptionalRelease' records the first release in which the feature was accepted. In the case of a `MandatoryRelease' that has not yet occurred, `MandatoryRelease' predicts the release in which the feature will become part of the language. Else `MandatoryRelease' records when the feature became part of the language; in releases at or after that, modules no longer need a future statement to use the feature in question, but may continue to use such imports. `MandatoryRelease' may also be ‘None’, meaning that a planned feature got dropped. Instances of class ‘_Feature’ have two corresponding methods, ‘getOptionalRelease()’ and ‘getMandatoryRelease()’. `CompilerFlag' is the (bitfield) flag that should be passed in the fourth argument to the built-in function *note compile(): 1b4. to enable the feature in dynamically compiled code. This flag is stored in the ‘compiler_flag’ attribute on ‘_Feature’ instances. No feature description will ever be deleted from *note __future__: 0. Since its introduction in Python 2.1 the following features have found their way into the language using this mechanism: feature optional in mandatory in effect -------------------------------------------------------------------------------------------------------------- nested_scopes 2.1.0b1 2.2 PEP 227(2): `Statically Nested Scopes' generators 2.2.0a1 2.3 PEP 255(3): `Simple Generators' division 2.2.0a2 3.0 PEP 238(4): `Changing the Division Operator' absolute_import 2.5.0a1 3.0 PEP 328(5): `Imports: Multi-Line and Absolute/Relative' with_statement 2.5.0a1 2.6 PEP 343(6): `The “with” Statement' print_function 2.6.0a2 3.0 PEP 3105(7): `Make print a function' unicode_literals 2.6.0a2 3.0 PEP 3112(8): `Bytes literals in Python 3000' generator_stop 3.5.0b1 3.7 PEP 479(9): `StopIteration handling inside generators' annotations 3.7.0b1 3.10 PEP 563(10): `Postponed evaluation of annotations' See also ........ *note Future statements: 1236. How the compiler treats future imports. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/__future__.py (2) https://www.python.org/dev/peps/pep-0227 (3) https://www.python.org/dev/peps/pep-0255 (4) https://www.python.org/dev/peps/pep-0238 (5) https://www.python.org/dev/peps/pep-0328 (6) https://www.python.org/dev/peps/pep-0343 (7) https://www.python.org/dev/peps/pep-3105 (8) https://www.python.org/dev/peps/pep-3112 (9) https://www.python.org/dev/peps/pep-0479 (10) https://www.python.org/dev/peps/pep-0563  File: python.info, Node: gc — Garbage Collector interface, Next: inspect — Inspect live objects, Prev: __future__ — Future statement definitions, Up: Python Runtime Services 5.29.12 ‘gc’ — Garbage Collector interface ------------------------------------------ __________________________________________________________________ This module provides an interface to the optional garbage collector. It provides the ability to disable the collector, tune the collection frequency, and set debugging options. It also provides access to unreachable objects that the collector found but cannot free. Since the collector supplements the reference counting already used in Python, you can disable the collector if you are sure your program does not create reference cycles. Automatic collection can be disabled by calling ‘gc.disable()’. To debug a leaking program call ‘gc.set_debug(gc.DEBUG_LEAK)’. Notice that this includes ‘gc.DEBUG_SAVEALL’, causing garbage-collected objects to be saved in gc.garbage for inspection. The *note gc: 86. module provides the following functions: -- Function: gc.enable () Enable automatic garbage collection. -- Function: gc.disable () Disable automatic garbage collection. -- Function: gc.isenabled () Return ‘True’ if automatic collection is enabled. -- Function: gc.collect (generation=2) With no arguments, run a full collection. The optional argument `generation' may be an integer specifying which generation to collect (from 0 to 2). A *note ValueError: 1fb. is raised if the generation number is invalid. The number of unreachable objects found is returned. The free lists maintained for a number of built-in types are cleared whenever a full collection or collection of the highest generation (2) is run. Not all items in some free lists may be freed due to the particular implementation, in particular *note float: 187. -- Function: gc.set_debug (flags) Set the garbage collection debugging flags. Debugging information will be written to ‘sys.stderr’. See below for a list of debugging flags which can be combined using bit operations to control debugging. -- Function: gc.get_debug () Return the debugging flags currently set. -- Function: gc.get_objects (generation=None) Returns a list of all objects tracked by the collector, excluding the list returned. If `generation' is not None, return only the objects tracked by the collector that are in that generation. Changed in version 3.8: New `generation' parameter. Raises an *note auditing event: fd1. ‘gc.get_objects’ with argument ‘generation’. -- Function: gc.get_stats () Return a list of three per-generation dictionaries containing collection statistics since interpreter start. The number of keys may change in the future, but currently each dictionary will contain the following items: * ‘collections’ is the number of times this generation was collected; * ‘collected’ is the total number of objects collected inside this generation; * ‘uncollectable’ is the total number of objects which were found to be uncollectable (and were therefore moved to the *note garbage: b40. list) inside this generation. New in version 3.4. -- Function: gc.set_threshold (threshold0[, threshold1[, threshold2]]) Set the garbage collection thresholds (the collection frequency). Setting `threshold0' to zero disables collection. The GC classifies objects into three generations depending on how many collection sweeps they have survived. New objects are placed in the youngest generation (generation ‘0’). If an object survives a collection it is moved into the next older generation. Since generation ‘2’ is the oldest generation, objects in that generation remain there after a collection. In order to decide when to run, the collector keeps track of the number object allocations and deallocations since the last collection. When the number of allocations minus the number of deallocations exceeds `threshold0', collection starts. Initially only generation ‘0’ is examined. If generation ‘0’ has been examined more than `threshold1' times since generation ‘1’ has been examined, then generation ‘1’ is examined as well. With the third generation, things are a bit more complicated, see Collecting the oldest generation(1) for more information. -- Function: gc.get_count () Return the current collection counts as a tuple of ‘(count0, count1, count2)’. -- Function: gc.get_threshold () Return the current collection thresholds as a tuple of ‘(threshold0, threshold1, threshold2)’. -- Function: gc.get_referrers (*objs) Return the list of objects that directly refer to any of objs. This function will only locate those containers which support garbage collection; extension types which do refer to other objects but do not support garbage collection will not be found. Note that objects which have already been dereferenced, but which live in cycles and have not yet been collected by the garbage collector can be listed among the resulting referrers. To get only currently live objects, call *note collect(): 22e. before calling *note get_referrers(): 31f5. Warning: Care must be taken when using objects returned by *note get_referrers(): 31f5. because some of them could still be under construction and hence in a temporarily invalid state. Avoid using *note get_referrers(): 31f5. for any purpose other than debugging. Raises an *note auditing event: fd1. ‘gc.get_referrers’ with argument ‘objs’. -- Function: gc.get_referents (*objs) Return a list of objects directly referred to by any of the arguments. The referents returned are those objects visited by the arguments’ C-level *note tp_traverse: 33e8. methods (if any), and may not be all objects actually directly reachable. *note tp_traverse: 33e8. methods are supported only by objects that support garbage collection, and are only required to visit objects that may be involved in a cycle. So, for example, if an integer is directly reachable from an argument, that integer object may or may not appear in the result list. Raises an *note auditing event: fd1. ‘gc.get_referents’ with argument ‘objs’. -- Function: gc.is_tracked (obj) Returns ‘True’ if the object is currently tracked by the garbage collector, ‘False’ otherwise. As a general rule, instances of atomic types aren’t tracked and instances of non-atomic types (containers, user-defined objects…) are. However, some type-specific optimizations can be present in order to suppress the garbage collector footprint of simple instances (e.g. dicts containing only atomic keys and values): >>> gc.is_tracked(0) False >>> gc.is_tracked("a") False >>> gc.is_tracked([]) True >>> gc.is_tracked({}) False >>> gc.is_tracked({"a": 1}) False >>> gc.is_tracked({"a": []}) True New in version 3.1. -- Function: gc.freeze () Freeze all the objects tracked by gc - move them to a permanent generation and ignore all the future collections. This can be used before a POSIX fork() call to make the gc copy-on-write friendly or to speed up collection. Also collection before a POSIX fork() call may free pages for future allocation which can cause copy-on-write too so it’s advised to disable gc in parent process and freeze before fork and enable gc in child process. New in version 3.7. -- Function: gc.unfreeze () Unfreeze the objects in the permanent generation, put them back into the oldest generation. New in version 3.7. -- Function: gc.get_freeze_count () Return the number of objects in the permanent generation. New in version 3.7. The following variables are provided for read-only access (you can mutate the values but should not rebind them): -- Data: gc.garbage A list of objects which the collector found to be unreachable but could not be freed (uncollectable objects). Starting with Python 3.4, this list should be empty most of the time, except when using instances of C extension types with a non-‘NULL’ ‘tp_del’ slot. If *note DEBUG_SAVEALL: 33e9. is set, then all unreachable objects will be added to this list rather than freed. Changed in version 3.2: If this list is non-empty at *note interpreter shutdown: 763, a *note ResourceWarning: 4d0. is emitted, which is silent by default. If *note DEBUG_UNCOLLECTABLE: b41. is set, in addition all uncollectable objects are printed. Changed in version 3.4: Following PEP 442(2), objects with a *note __del__(): 91f. method don’t end up in *note gc.garbage: b40. anymore. -- Data: gc.callbacks A list of callbacks that will be invoked by the garbage collector before and after collection. The callbacks will be called with two arguments, `phase' and `info'. `phase' can be one of two values: “start”: The garbage collection is about to start. “stop”: The garbage collection has finished. `info' is a dict providing more information for the callback. The following keys are currently defined: “generation”: The oldest generation being collected. “collected”: When `phase' is “stop”, the number of objects successfully collected. “uncollectable”: When `phase' is “stop”, the number of objects that could not be collected and were put in *note garbage: b40. Applications can add their own callbacks to this list. The primary use cases are: Gathering statistics about garbage collection, such as how often various generations are collected, and how long the collection takes. Allowing applications to identify and clear their own uncollectable types when they appear in *note garbage: b40. New in version 3.3. The following constants are provided for use with *note set_debug(): 33e3.: -- Data: gc.DEBUG_STATS Print statistics during collection. This information can be useful when tuning the collection frequency. -- Data: gc.DEBUG_COLLECTABLE Print information on collectable objects found. -- Data: gc.DEBUG_UNCOLLECTABLE Print information of uncollectable objects found (objects which are not reachable but cannot be freed by the collector). These objects will be added to the ‘garbage’ list. Changed in version 3.2: Also print the contents of the *note garbage: b40. list at *note interpreter shutdown: 763, if it isn’t empty. -- Data: gc.DEBUG_SAVEALL When set, all unreachable objects found will be appended to `garbage' rather than being freed. This can be useful for debugging a leaking program. -- Data: gc.DEBUG_LEAK The debugging flags necessary for the collector to print information about a leaking program (equal to ‘DEBUG_COLLECTABLE | DEBUG_UNCOLLECTABLE | DEBUG_SAVEALL’). ---------- Footnotes ---------- (1) https://devguide.python.org/garbage_collector/#collecting-the-oldest-generation (2) https://www.python.org/dev/peps/pep-0442  File: python.info, Node: inspect — Inspect live objects, Next: site — Site-specific configuration hook, Prev: gc — Garbage Collector interface, Up: Python Runtime Services 5.29.13 ‘inspect’ — Inspect live objects ---------------------------------------- `Source code:' Lib/inspect.py(1) __________________________________________________________________ The *note inspect: a0. module provides several useful functions to help get information about live objects such as modules, classes, methods, functions, tracebacks, frame objects, and code objects. For example, it can help you examine the contents of a class, retrieve the source code of a method, extract and format the argument list for a function, or get all the information you need to display a detailed traceback. There are four main kinds of services provided by this module: type checking, getting source code, inspecting classes and functions, and examining the interpreter stack. * Menu: * Types and members:: * Retrieving source code:: * Introspecting callables with the Signature object:: * Classes and functions: Classes and functions<2>. * The interpreter stack:: * Fetching attributes statically:: * Current State of Generators and Coroutines:: * Code Objects Bit Flags:: * Command Line Interface: Command Line Interface<3>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/inspect.py  File: python.info, Node: Types and members, Next: Retrieving source code, Up: inspect — Inspect live objects 5.29.13.1 Types and members ........................... The *note getmembers(): 33f1. function retrieves the members of an object such as a class or module. The functions whose names begin with “is” are mainly provided as convenient choices for the second argument to *note getmembers(): 33f1. They also help you determine when you can expect to find the following special attributes: Type Attribute Description ------------------------------------------------------------------------ module __doc__ documentation string __file__ filename (missing for built-in modules) class __doc__ documentation string __name__ name with which this class was defined __qualname__ qualified name __module__ name of module in which this class was defined method __doc__ documentation string __name__ name with which this method was defined __qualname__ qualified name __func__ function object containing implementation of method __self__ instance to which this method is bound, or ‘None’ __module__ name of module in which this method was defined function __doc__ documentation string __name__ name with which this function was defined __qualname__ qualified name __code__ code object containing compiled function *note bytecode: 614. __defaults__ tuple of any default values for positional or keyword parameters __kwdefaults__ mapping of any default values for keyword-only parameters __globals__ global namespace in which this function was defined __annotations__ mapping of parameters names to annotations; ‘"return"’ key is reserved for return annotations. __module__ name of module in which this function was defined traceback tb_frame frame object at this level tb_lasti index of last attempted instruction in bytecode tb_lineno current line number in Python source code tb_next next inner traceback object (called by this level) frame f_back next outer frame object (this frame’s caller) f_builtins builtins namespace seen by this frame f_code code object being executed in this frame f_globals global namespace seen by this frame f_lasti index of last attempted instruction in bytecode f_lineno current line number in Python source code f_locals local namespace seen by this frame f_trace tracing function for this frame, or ‘None’ code co_argcount number of arguments (not including keyword only arguments, * or ** args) co_code string of raw compiled bytecode co_cellvars tuple of names of cell variables (referenced by containing scopes) co_consts tuple of constants used in the bytecode co_filename name of file in which this code object was created co_firstlineno number of first line in Python source code co_flags bitmap of ‘CO_*’ flags, read more *note here: 33f2. co_lnotab encoded mapping of line numbers to bytecode indices co_freevars tuple of names of free variables (referenced via a function’s closure) co_posonlyargcount number of positional only arguments co_kwonlyargcount number of keyword only arguments (not including ** arg) co_name name with which this code object was defined co_names tuple of names of local variables co_nlocals number of local variables co_stacksize virtual machine stack space required co_varnames tuple of names of arguments and local variables generator __name__ name __qualname__ qualified name gi_frame frame gi_running is the generator running? gi_code code gi_yieldfrom object being iterated by ‘yield from’, or ‘None’ coroutine __name__ name __qualname__ qualified name cr_await object being awaited on, or ‘None’ cr_frame frame cr_running is the coroutine running? cr_code code cr_origin where coroutine was created, or ‘None’. See *note sys.set_coroutine_origin_tracking_depth(): 3f3. builtin __doc__ documentation string __name__ original name of this function or method __qualname__ qualified name __self__ instance to which a method is bound, or ‘None’ Changed in version 3.5: Add ‘__qualname__’ and ‘gi_yieldfrom’ attributes to generators. The ‘__name__’ attribute of generators is now set from the function name, instead of the code name, and it can now be modified. Changed in version 3.7: Add ‘cr_origin’ attribute to coroutines. -- Function: inspect.getmembers (object[, predicate]) Return all the members of an object in a list of ‘(name, value)’ pairs sorted by name. If the optional `predicate' argument—which will be called with the ‘value’ object of each member—is supplied, only members for which the predicate returns a true value are included. Note: *note getmembers(): 33f1. will only return class attributes defined in the metaclass when the argument is a class and those attributes have been listed in the metaclass’ custom *note __dir__(): 31b. -- Function: inspect.getmodulename (path) Return the name of the module named by the file `path', without including the names of enclosing packages. The file extension is checked against all of the entries in *note importlib.machinery.all_suffixes(): 33f3. If it matches, the final path component is returned with the extension removed. Otherwise, ‘None’ is returned. Note that this function `only' returns a meaningful name for actual Python modules - paths that potentially refer to Python packages will still return ‘None’. Changed in version 3.3: The function is based directly on *note importlib: 9b. -- Function: inspect.ismodule (object) Return ‘True’ if the object is a module. -- Function: inspect.isclass (object) Return ‘True’ if the object is a class, whether built-in or created in Python code. -- Function: inspect.ismethod (object) Return ‘True’ if the object is a bound method written in Python. -- Function: inspect.isfunction (object) Return ‘True’ if the object is a Python function, which includes functions created by a *note lambda: 33f8. expression. -- Function: inspect.isgeneratorfunction (object) Return ‘True’ if the object is a Python generator function. Changed in version 3.8: Functions wrapped in *note functools.partial(): 7c8. now return ‘True’ if the wrapped function is a Python generator function. -- Function: inspect.isgenerator (object) Return ‘True’ if the object is a generator. -- Function: inspect.iscoroutinefunction (object) Return ‘True’ if the object is a *note coroutine function: 63f. (a function defined with an *note async def: 284. syntax). New in version 3.5. Changed in version 3.8: Functions wrapped in *note functools.partial(): 7c8. now return ‘True’ if the wrapped function is a *note coroutine function: 63f. -- Function: inspect.iscoroutine (object) Return ‘True’ if the object is a *note coroutine: 1a6. created by an *note async def: 284. function. New in version 3.5. -- Function: inspect.isawaitable (object) Return ‘True’ if the object can be used in *note await: 1a3. expression. Can also be used to distinguish generator-based coroutines from regular generators: def gen(): yield @types.coroutine def gen_coro(): yield assert not isawaitable(gen()) assert isawaitable(gen_coro()) New in version 3.5. -- Function: inspect.isasyncgenfunction (object) Return ‘True’ if the object is an *note asynchronous generator: 11a9. function, for example: >>> async def agen(): ... yield 1 ... >>> inspect.isasyncgenfunction(agen) True New in version 3.6. Changed in version 3.8: Functions wrapped in *note functools.partial(): 7c8. now return ‘True’ if the wrapped function is a *note asynchronous generator: 11a9. function. -- Function: inspect.isasyncgen (object) Return ‘True’ if the object is an *note asynchronous generator iterator: 335c. created by an *note asynchronous generator: 11a9. function. New in version 3.6. -- Function: inspect.istraceback (object) Return ‘True’ if the object is a traceback. -- Function: inspect.isframe (object) Return ‘True’ if the object is a frame. -- Function: inspect.iscode (object) Return ‘True’ if the object is a code. -- Function: inspect.isbuiltin (object) Return ‘True’ if the object is a built-in function or a bound built-in method. -- Function: inspect.isroutine (object) Return ‘True’ if the object is a user-defined or built-in function or method. -- Function: inspect.isabstract (object) Return ‘True’ if the object is an abstract base class. -- Function: inspect.ismethoddescriptor (object) Return ‘True’ if the object is a method descriptor, but not if *note ismethod(): 33f6, *note isclass(): 33f5, *note isfunction(): 33f7. or *note isbuiltin(): 3400. are true. This, for example, is true of ‘int.__add__’. An object passing this test has a *note __get__(): 10dd. method but not a *note __set__(): 10e1. method, but beyond that the set of attributes varies. A *note __name__: c67. attribute is usually sensible, and ‘__doc__’ often is. Methods implemented via descriptors that also pass one of the other tests return ‘False’ from the *note ismethoddescriptor(): 3403. test, simply because the other tests promise more – you can, e.g., count on having the ‘__func__’ attribute (etc) when an object passes *note ismethod(): 33f6. -- Function: inspect.isdatadescriptor (object) Return ‘True’ if the object is a data descriptor. Data descriptors have a *note __set__: 10e1. or a *note __delete__: 10e2. method. Examples are properties (defined in Python), getsets, and members. The latter two are defined in C and there are more specific tests available for those types, which is robust across Python implementations. Typically, data descriptors will also have *note __name__: c67. and ‘__doc__’ attributes (properties, getsets, and members have both of these attributes), but this is not guaranteed. -- Function: inspect.isgetsetdescriptor (object) Return ‘True’ if the object is a getset descriptor. `CPython implementation detail:' getsets are attributes defined in extension modules via *note PyGetSetDef: 427. structures. For Python implementations without such types, this method will always return ‘False’. -- Function: inspect.ismemberdescriptor (object) Return ‘True’ if the object is a member descriptor. `CPython implementation detail:' Member descriptors are attributes defined in extension modules via *note PyMemberDef: 426. structures. For Python implementations without such types, this method will always return ‘False’.  File: python.info, Node: Retrieving source code, Next: Introspecting callables with the Signature object, Prev: Types and members, Up: inspect — Inspect live objects 5.29.13.2 Retrieving source code ................................ -- Function: inspect.getdoc (object) Get the documentation string for an object, cleaned up with *note cleandoc(): 3409. If the documentation string for an object is not provided and the object is a class, a method, a property or a descriptor, retrieve the documentation string from the inheritance hierarchy. Changed in version 3.5: Documentation strings are now inherited if not overridden. -- Function: inspect.getcomments (object) Return in a single string any lines of comments immediately preceding the object’s source code (for a class, function, or method), or at the top of the Python source file (if the object is a module). If the object’s source code is unavailable, return ‘None’. This could happen if the object has been defined in C or the interactive shell. -- Function: inspect.getfile (object) Return the name of the (text or binary) file in which an object was defined. This will fail with a *note TypeError: 192. if the object is a built-in module, class, or function. -- Function: inspect.getmodule (object) Try to guess which module an object was defined in. -- Function: inspect.getsourcefile (object) Return the name of the Python source file in which an object was defined. This will fail with a *note TypeError: 192. if the object is a built-in module, class, or function. -- Function: inspect.getsourcelines (object) Return a list of source lines and starting line number for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a list of the lines corresponding to the object and the line number indicates where in the original source file the first line of code was found. An *note OSError: 1d3. is raised if the source code cannot be retrieved. Changed in version 3.3: *note OSError: 1d3. is raised instead of *note IOError: 992, now an alias of the former. -- Function: inspect.getsource (object) Return the text of the source code for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a single string. An *note OSError: 1d3. is raised if the source code cannot be retrieved. Changed in version 3.3: *note OSError: 1d3. is raised instead of *note IOError: 992, now an alias of the former. -- Function: inspect.cleandoc (doc) Clean up indentation from docstrings that are indented to line up with blocks of code. All leading whitespace is removed from the first line. Any leading whitespace that can be uniformly removed from the second line onwards is removed. Empty lines at the beginning and end are subsequently removed. Also, all tabs are expanded to spaces.  File: python.info, Node: Introspecting callables with the Signature object, Next: Classes and functions<2>, Prev: Retrieving source code, Up: inspect — Inspect live objects 5.29.13.3 Introspecting callables with the Signature object ........................................................... New in version 3.3. The Signature object represents the call signature of a callable object and its return annotation. To retrieve a Signature object, use the *note signature(): 55b. function. -- Function: inspect.signature (callable, *, follow_wrapped=True) Return a *note Signature: 6f3. object for the given ‘callable’: >>> from inspect import signature >>> def foo(a, *, b:int, **kwargs): ... pass >>> sig = signature(foo) >>> str(sig) '(a, *, b:int, **kwargs)' >>> str(sig.parameters['b']) 'b:int' >>> sig.parameters['b'].annotation <class 'int'> Accepts a wide range of Python callables, from plain functions and classes to *note functools.partial(): 7c8. objects. Raises *note ValueError: 1fb. if no signature can be provided, and *note TypeError: 192. if that type of object is not supported. A slash(/) in the signature of a function denotes that the parameters prior to it are positional-only. For more info, see *note the FAQ entry on positional-only parameters: 129d. New in version 3.5: ‘follow_wrapped’ parameter. Pass ‘False’ to get a signature of ‘callable’ specifically (‘callable.__wrapped__’ will not be used to unwrap decorated callables.) Note: Some callables may not be introspectable in certain implementations of Python. For example, in CPython, some built-in functions defined in C provide no metadata about their arguments. -- Class: inspect.Signature (parameters=None, *, return_annotation=Signature.empty) A Signature object represents the call signature of a function and its return annotation. For each parameter accepted by the function it stores a *note Parameter: 6f4. object in its *note parameters: 3411. collection. The optional `parameters' argument is a sequence of *note Parameter: 6f4. objects, which is validated to check that there are no parameters with duplicate names, and that the parameters are in the right order, i.e. positional-only first, then positional-or-keyword, and that parameters with defaults follow parameters without defaults. The optional `return_annotation' argument, can be an arbitrary Python object, is the “return” annotation of the callable. Signature objects are `immutable'. Use *note Signature.replace(): 3412. to make a modified copy. Changed in version 3.5: Signature objects are picklable and hashable. -- Attribute: empty A special class-level marker to specify absence of a return annotation. -- Attribute: parameters An ordered mapping of parameters’ names to the corresponding *note Parameter: 6f4. objects. Parameters appear in strict definition order, including keyword-only parameters. Changed in version 3.7: Python only explicitly guaranteed that it preserved the declaration order of keyword-only parameters as of version 3.7, although in practice this order had always been preserved in Python 3. -- Attribute: return_annotation The “return” annotation for the callable. If the callable has no “return” annotation, this attribute is set to *note Signature.empty: 3413. -- Method: bind (*args, **kwargs) Create a mapping from positional and keyword arguments to parameters. Returns *note BoundArguments: 9a8. if ‘*args’ and ‘**kwargs’ match the signature, or raises a *note TypeError: 192. -- Method: bind_partial (*args, **kwargs) Works the same way as *note Signature.bind(): 3415, but allows the omission of some required arguments (mimics *note functools.partial(): 7c8. behavior.) Returns *note BoundArguments: 9a8, or raises a *note TypeError: 192. if the passed arguments do not match the signature. -- Method: replace (*[, parameters][, return_annotation]) Create a new Signature instance based on the instance replace was invoked on. It is possible to pass different ‘parameters’ and/or ‘return_annotation’ to override the corresponding properties of the base signature. To remove return_annotation from the copied Signature, pass in *note Signature.empty: 3413. >>> def test(a, b): ... pass >>> sig = signature(test) >>> new_sig = sig.replace(return_annotation="new return anno") >>> str(new_sig) "(a, b) -> 'new return anno'" -- Method: classmethod from_callable (obj, *, follow_wrapped=True) Return a *note Signature: 6f3. (or its subclass) object for a given callable ‘obj’. Pass ‘follow_wrapped=False’ to get a signature of ‘obj’ without unwrapping its ‘__wrapped__’ chain. This method simplifies subclassing of *note Signature: 6f3.: class MySignature(Signature): pass sig = MySignature.from_callable(min) assert isinstance(sig, MySignature) New in version 3.5. -- Class: inspect.Parameter (name, kind, *, default=Parameter.empty, annotation=Parameter.empty) Parameter objects are `immutable'. Instead of modifying a Parameter object, you can use *note Parameter.replace(): 3417. to create a modified copy. Changed in version 3.5: Parameter objects are picklable and hashable. -- Attribute: empty A special class-level marker to specify absence of default values and annotations. -- Attribute: name The name of the parameter as a string. The name must be a valid Python identifier. `CPython implementation detail:' CPython generates implicit parameter names of the form ‘.0’ on the code objects used to implement comprehensions and generator expressions. Changed in version 3.6: These parameter names are exposed by this module as names like ‘implicit0’. -- Attribute: default The default value for the parameter. If the parameter has no default value, this attribute is set to *note Parameter.empty: 3418. -- Attribute: annotation The annotation for the parameter. If the parameter has no annotation, this attribute is set to *note Parameter.empty: 3418. -- Attribute: kind Describes how argument values are bound to the parameter. Possible values (accessible via *note Parameter: 6f4, like ‘Parameter.KEYWORD_ONLY’): Name Meaning -------------------------------------------------------------------------------- `POSITIONAL_ONLY' Value must be supplied as a positional argument. Positional only parameters are those which appear before a ‘/’ entry (if present) in a Python function definition. `POSITIONAL_OR_KEYWORD' Value may be supplied as either a keyword or positional argument (this is the standard binding behaviour for functions implemented in Python.) `VAR_POSITIONAL' A tuple of positional arguments that aren’t bound to any other parameter. This corresponds to a ‘*args’ parameter in a Python function definition. `KEYWORD_ONLY' Value must be supplied as a keyword argument. Keyword only parameters are those which appear after a ‘*’ or ‘*args’ entry in a Python function definition. `VAR_KEYWORD' A dict of keyword arguments that aren’t bound to any other parameter. This corresponds to a ‘**kwargs’ parameter in a Python function definition. Example: print all keyword-only arguments without default values: >>> def foo(a, b, *, c, d=10): ... pass >>> sig = signature(foo) >>> for param in sig.parameters.values(): ... if (param.kind == param.KEYWORD_ONLY and ... param.default is param.empty): ... print('Parameter:', param) Parameter: c -- Attribute: kind.description Describes a enum value of Parameter.kind. New in version 3.8. Example: print all descriptions of arguments: >>> def foo(a, b, *, c, d=10): ... pass >>> sig = signature(foo) >>> for param in sig.parameters.values(): ... print(param.kind.description) positional or keyword positional or keyword keyword-only keyword-only -- Method: replace (*[, name][, kind][, default][, annotation]) Create a new Parameter instance based on the instance replaced was invoked on. To override a *note Parameter: 6f4. attribute, pass the corresponding argument. To remove a default value or/and an annotation from a Parameter, pass *note Parameter.empty: 3418. >>> from inspect import Parameter >>> param = Parameter('foo', Parameter.KEYWORD_ONLY, default=42) >>> str(param) 'foo=42' >>> str(param.replace()) # Will create a shallow copy of 'param' 'foo=42' >>> str(param.replace(default=Parameter.empty, annotation='spam')) "foo:'spam'" Changed in version 3.4: In Python 3.3 Parameter objects were allowed to have ‘name’ set to ‘None’ if their ‘kind’ was set to ‘POSITIONAL_ONLY’. This is no longer permitted. -- Class: inspect.BoundArguments Result of a *note Signature.bind(): 3415. or *note Signature.bind_partial(): 3416. call. Holds the mapping of arguments to the function’s parameters. -- Attribute: arguments An ordered, mutable mapping (*note collections.OrderedDict: 1b9.) of parameters’ names to arguments’ values. Contains only explicitly bound arguments. Changes in *note arguments: 341e. will reflect in *note args: 341f. and *note kwargs: 3420. Should be used in conjunction with *note Signature.parameters: 3411. for any argument processing purposes. Note: Arguments for which *note Signature.bind(): 3415. or *note Signature.bind_partial(): 3416. relied on a default value are skipped. However, if needed, use *note BoundArguments.apply_defaults(): 6f5. to add them. -- Attribute: args A tuple of positional arguments values. Dynamically computed from the *note arguments: 341e. attribute. -- Attribute: kwargs A dict of keyword arguments values. Dynamically computed from the *note arguments: 341e. attribute. -- Attribute: signature A reference to the parent *note Signature: 6f3. object. -- Method: apply_defaults () Set default values for missing arguments. For variable-positional arguments (‘*args’) the default is an empty tuple. For variable-keyword arguments (‘**kwargs’) the default is an empty dict. >>> def foo(a, b='ham', *args): pass >>> ba = inspect.signature(foo).bind('spam') >>> ba.apply_defaults() >>> ba.arguments OrderedDict([('a', 'spam'), ('b', 'ham'), ('args', ())]) New in version 3.5. The *note args: 341f. and *note kwargs: 3420. properties can be used to invoke functions: def test(a, *, b): ... sig = signature(test) ba = sig.bind(10, b=20) test(*ba.args, **ba.kwargs) See also ........ PEP 362(1) - Function Signature Object. The detailed specification, implementation details and examples. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0362  File: python.info, Node: Classes and functions<2>, Next: The interpreter stack, Prev: Introspecting callables with the Signature object, Up: inspect — Inspect live objects 5.29.13.4 Classes and functions ............................... -- Function: inspect.getclasstree (classes, unique=False) Arrange the given list of classes into a hierarchy of nested lists. Where a nested list appears, it contains classes derived from the class whose entry immediately precedes the list. Each entry is a 2-tuple containing a class and a tuple of its base classes. If the `unique' argument is true, exactly one entry appears in the returned structure for each class in the given list. Otherwise, classes using multiple inheritance and their descendants will appear multiple times. -- Function: inspect.getargspec (func) Get the names and default values of a Python function’s parameters. A *note named tuple: aa3. ‘ArgSpec(args, varargs, keywords, defaults)’ is returned. `args' is a list of the parameter names. `varargs' and `keywords' are the names of the ‘*’ and ‘**’ parameters or ‘None’. `defaults' is a tuple of default argument values or ‘None’ if there are no default arguments; if this tuple has `n' elements, they correspond to the last `n' elements listed in `args'. Deprecated since version 3.0: Use *note getfullargspec(): 55d. for an updated API that is usually a drop-in replacement, but also correctly handles function annotations and keyword-only parameters. Alternatively, use *note signature(): 55b. and *note Signature Object: 340f, which provide a more structured introspection API for callables. -- Function: inspect.getfullargspec (func) Get the names and default values of a Python function’s parameters. A *note named tuple: aa3. is returned: ‘FullArgSpec(args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, annotations)’ `args' is a list of the positional parameter names. `varargs' is the name of the ‘*’ parameter or ‘None’ if arbitrary positional arguments are not accepted. `varkw' is the name of the ‘**’ parameter or ‘None’ if arbitrary keyword arguments are not accepted. `defaults' is an `n'-tuple of default argument values corresponding to the last `n' positional parameters, or ‘None’ if there are no such defaults defined. `kwonlyargs' is a list of keyword-only parameter names in declaration order. `kwonlydefaults' is a dictionary mapping parameter names from `kwonlyargs' to the default values used if no argument is supplied. `annotations' is a dictionary mapping parameter names to annotations. The special key ‘"return"’ is used to report the function return value annotation (if any). Note that *note signature(): 55b. and *note Signature Object: 340f. provide the recommended API for callable introspection, and support additional behaviours (like positional-only arguments) that are sometimes encountered in extension module APIs. This function is retained primarily for use in code that needs to maintain compatibility with the Python 2 ‘inspect’ module API. Changed in version 3.4: This function is now based on *note signature(): 55b, but still ignores ‘__wrapped__’ attributes and includes the already bound first parameter in the signature output for bound methods. Changed in version 3.6: This method was previously documented as deprecated in favour of *note signature(): 55b. in Python 3.5, but that decision has been reversed in order to restore a clearly supported standard interface for single-source Python 2/3 code migrating away from the legacy *note getargspec(): 55c. API. Changed in version 3.7: Python only explicitly guaranteed that it preserved the declaration order of keyword-only parameters as of version 3.7, although in practice this order had always been preserved in Python 3. -- Function: inspect.getargvalues (frame) Get information about arguments passed into a particular frame. A *note named tuple: aa3. ‘ArgInfo(args, varargs, keywords, locals)’ is returned. `args' is a list of the argument names. `varargs' and `keywords' are the names of the ‘*’ and ‘**’ arguments or ‘None’. `locals' is the locals dictionary of the given frame. Note: This function was inadvertently marked as deprecated in Python 3.5. -- Function: inspect.formatargspec (args[, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, annotations[, formatarg, formatvarargs, formatvarkw, formatvalue, formatreturns, formatannotations]]) Format a pretty argument spec from the values returned by *note getfullargspec(): 55d. The first seven arguments are (‘args’, ‘varargs’, ‘varkw’, ‘defaults’, ‘kwonlyargs’, ‘kwonlydefaults’, ‘annotations’). The other six arguments are functions that are called to turn argument names, ‘*’ argument name, ‘**’ argument name, default values, return annotation and individual annotations into strings, respectively. For example: >>> from inspect import formatargspec, getfullargspec >>> def f(a: int, b: float): ... pass ... >>> formatargspec(*getfullargspec(f)) '(a: int, b: float)' Deprecated since version 3.5: Use *note signature(): 55b. and *note Signature Object: 340f, which provide a better introspecting API for callables. -- Function: inspect.formatargvalues (args[, varargs, varkw, locals, formatarg, formatvarargs, formatvarkw, formatvalue]) Format a pretty argument spec from the four values returned by *note getargvalues(): 7b8. The format* arguments are the corresponding optional formatting functions that are called to turn names and values into strings. Note: This function was inadvertently marked as deprecated in Python 3.5. -- Function: inspect.getmro (cls) Return a tuple of class cls’s base classes, including cls, in method resolution order. No class appears more than once in this tuple. Note that the method resolution order depends on cls’s type. Unless a very peculiar user-defined metatype is in use, cls will be the first element of the tuple. -- Function: inspect.getcallargs (func, /, *args, **kwds) Bind the `args' and `kwds' to the argument names of the Python function or method `func', as if it was called with them. For bound methods, bind also the first argument (typically named ‘self’) to the associated instance. A dict is returned, mapping the argument names (including the names of the ‘*’ and ‘**’ arguments, if any) to their values from `args' and `kwds'. In case of invoking `func' incorrectly, i.e. whenever ‘func(*args, **kwds)’ would raise an exception because of incompatible signature, an exception of the same type and the same or similar message is raised. For example: >>> from inspect import getcallargs >>> def f(a, b=1, *pos, **named): ... pass >>> getcallargs(f, 1, 2, 3) == {'a': 1, 'named': {}, 'b': 2, 'pos': (3,)} True >>> getcallargs(f, a=2, x=4) == {'a': 2, 'named': {'x': 4}, 'b': 1, 'pos': ()} True >>> getcallargs(f) Traceback (most recent call last): ... TypeError: f() missing 1 required positional argument: 'a' New in version 3.2. Deprecated since version 3.5: Use *note Signature.bind(): 3415. and *note Signature.bind_partial(): 3416. instead. -- Function: inspect.getclosurevars (func) Get the mapping of external name references in a Python function or method `func' to their current values. A *note named tuple: aa3. ‘ClosureVars(nonlocals, globals, builtins, unbound)’ is returned. `nonlocals' maps referenced names to lexical closure variables, `globals' to the function’s module globals and `builtins' to the builtins visible from the function body. `unbound' is the set of names referenced in the function that could not be resolved at all given the current module globals and builtins. *note TypeError: 192. is raised if `func' is not a Python function or method. New in version 3.3. -- Function: inspect.unwrap (func, *, stop=None) Get the object wrapped by `func'. It follows the chain of ‘__wrapped__’ attributes returning the last object in the chain. `stop' is an optional callback accepting an object in the wrapper chain as its sole argument that allows the unwrapping to be terminated early if the callback returns a true value. If the callback never returns a true value, the last object in the chain is returned as usual. For example, *note signature(): 55b. uses this to stop unwrapping if any object in the chain has a ‘__signature__’ attribute defined. *note ValueError: 1fb. is raised if a cycle is encountered. New in version 3.4.  File: python.info, Node: The interpreter stack, Next: Fetching attributes statically, Prev: Classes and functions<2>, Up: inspect — Inspect live objects 5.29.13.5 The interpreter stack ............................... When the following functions return “frame records,” each record is a *note named tuple: aa3. ‘FrameInfo(frame, filename, lineno, function, code_context, index)’. The tuple contains the frame object, the filename, the line number of the current line, the function name, a list of lines of context from the source code, and the index of the current line within that list. Changed in version 3.5: Return a named tuple instead of a tuple. Note: Keeping references to frame objects, as found in the first element of the frame records these functions return, can cause your program to create reference cycles. Once a reference cycle has been created, the lifespan of all objects which can be accessed from the objects which form the cycle can become much longer even if Python’s optional cycle detector is enabled. If such cycles must be created, it is important to ensure they are explicitly broken to avoid the delayed destruction of objects and increased memory consumption which occurs. Though the cycle detector will catch these, destruction of the frames (and local variables) can be made deterministic by removing the cycle in a *note finally: 182. clause. This is also important if the cycle detector was disabled when Python was compiled or using *note gc.disable(): 33e1. For example: def handle_stackframe_without_leak(): frame = inspect.currentframe() try: # do something with the frame finally: del frame If you want to keep the frame around (for example to print a traceback later), you can also break reference cycles by using the *note frame.clear(): 80b. method. The optional `context' argument supported by most of these functions specifies the number of lines of context to return, which are centered around the current line. -- Function: inspect.getframeinfo (frame, context=1) Get information about a frame or traceback object. A *note named tuple: aa3. ‘Traceback(filename, lineno, function, code_context, index)’ is returned. -- Function: inspect.getouterframes (frame, context=1) Get a list of frame records for a frame and all outer frames. These frames represent the calls that lead to the creation of `frame'. The first entry in the returned list represents `frame'; the last entry represents the outermost call on `frame'’s stack. Changed in version 3.5: A list of *note named tuples: aa3. ‘FrameInfo(frame, filename, lineno, function, code_context, index)’ is returned. -- Function: inspect.getinnerframes (traceback, context=1) Get a list of frame records for a traceback’s frame and all inner frames. These frames represent calls made as a consequence of `frame'. The first entry in the list represents `traceback'; the last entry represents where the exception was raised. Changed in version 3.5: A list of *note named tuples: aa3. ‘FrameInfo(frame, filename, lineno, function, code_context, index)’ is returned. -- Function: inspect.currentframe () Return the frame object for the caller’s stack frame. `CPython implementation detail:' This function relies on Python stack frame support in the interpreter, which isn’t guaranteed to exist in all implementations of Python. If running in an implementation without Python stack frame support this function returns ‘None’. -- Function: inspect.stack (context=1) Return a list of frame records for the caller’s stack. The first entry in the returned list represents the caller; the last entry represents the outermost call on the stack. Changed in version 3.5: A list of *note named tuples: aa3. ‘FrameInfo(frame, filename, lineno, function, code_context, index)’ is returned. -- Function: inspect.trace (context=1) Return a list of frame records for the stack between the current frame and the frame in which an exception currently being handled was raised in. The first entry in the list represents the caller; the last entry represents where the exception was raised. Changed in version 3.5: A list of *note named tuples: aa3. ‘FrameInfo(frame, filename, lineno, function, code_context, index)’ is returned.  File: python.info, Node: Fetching attributes statically, Next: Current State of Generators and Coroutines, Prev: The interpreter stack, Up: inspect — Inspect live objects 5.29.13.6 Fetching attributes statically ........................................ Both *note getattr(): 448. and *note hasattr(): 447. can trigger code execution when fetching or checking for the existence of attributes. Descriptors, like properties, will be invoked and *note __getattr__(): 31a. and *note __getattribute__(): 449. may be called. For cases where you want passive introspection, like documentation tools, this can be inconvenient. *note getattr_static(): bcb. has the same signature as *note getattr(): 448. but avoids executing code when it fetches attributes. -- Function: inspect.getattr_static (obj, attr, default=None) Retrieve attributes without triggering dynamic lookup via the descriptor protocol, *note __getattr__(): 31a. or *note __getattribute__(): 449. Note: this function may not be able to retrieve all attributes that getattr can fetch (like dynamically created attributes) and may find attributes that getattr can’t (like descriptors that raise AttributeError). It can also return descriptors objects instead of instance members. If the instance *note __dict__: 4fc. is shadowed by another member (for example a property) then this function will be unable to find instance members. New in version 3.2. *note getattr_static(): bcb. does not resolve descriptors, for example slot descriptors or getset descriptors on objects implemented in C. The descriptor object is returned instead of the underlying attribute. You can handle these with code like the following. Note that for arbitrary getset descriptors invoking these may trigger code execution: # example code for resolving the builtin descriptor types class _foo: __slots__ = ['foo'] slot_descriptor = type(_foo.foo) getset_descriptor = type(type(open(__file__)).name) wrapper_descriptor = type(str.__dict__['__add__']) descriptor_types = (slot_descriptor, getset_descriptor, wrapper_descriptor) result = getattr_static(some_object, 'foo') if type(result) in descriptor_types: try: result = result.__get__() except AttributeError: # descriptors can raise AttributeError to # indicate there is no underlying value # in which case the descriptor itself will # have to do pass  File: python.info, Node: Current State of Generators and Coroutines, Next: Code Objects Bit Flags, Prev: Fetching attributes statically, Up: inspect — Inspect live objects 5.29.13.7 Current State of Generators and Coroutines .................................................... When implementing coroutine schedulers and for other advanced uses of generators, it is useful to determine whether a generator is currently executing, is waiting to start or resume or execution, or has already terminated. *note getgeneratorstate(): bca. allows the current state of a generator to be determined easily. -- Function: inspect.getgeneratorstate (generator) Get current state of a generator-iterator. Possible states are: * GEN_CREATED: Waiting to start execution. * GEN_RUNNING: Currently being executed by the interpreter. * GEN_SUSPENDED: Currently suspended at a yield expression. * GEN_CLOSED: Execution has completed. New in version 3.2. -- Function: inspect.getcoroutinestate (coroutine) Get current state of a coroutine object. The function is intended to be used with coroutine objects created by *note async def: 284. functions, but will accept any coroutine-like object that has ‘cr_running’ and ‘cr_frame’ attributes. Possible states are: * CORO_CREATED: Waiting to start execution. * CORO_RUNNING: Currently being executed by the interpreter. * CORO_SUSPENDED: Currently suspended at an await expression. * CORO_CLOSED: Execution has completed. New in version 3.5. The current internal state of the generator can also be queried. This is mostly useful for testing purposes, to ensure that internal state is being updated as expected: -- Function: inspect.getgeneratorlocals (generator) Get the mapping of live local variables in `generator' to their current values. A dictionary is returned that maps from variable names to values. This is the equivalent of calling *note locals(): 455. in the body of the generator, and all the same caveats apply. If `generator' is a *note generator: 9a2. with no currently associated frame, then an empty dictionary is returned. *note TypeError: 192. is raised if `generator' is not a Python generator object. `CPython implementation detail:' This function relies on the generator exposing a Python stack frame for introspection, which isn’t guaranteed to be the case in all implementations of Python. In such cases, this function will always return an empty dictionary. New in version 3.3. -- Function: inspect.getcoroutinelocals (coroutine) This function is analogous to *note getgeneratorlocals(): a1a, but works for coroutine objects created by *note async def: 284. functions. New in version 3.5.  File: python.info, Node: Code Objects Bit Flags, Next: Command Line Interface<3>, Prev: Current State of Generators and Coroutines, Up: inspect — Inspect live objects 5.29.13.8 Code Objects Bit Flags ................................ Python code objects have a ‘co_flags’ attribute, which is a bitmap of the following flags: -- Data: inspect.CO_OPTIMIZED The code object is optimized, using fast locals. -- Data: inspect.CO_NEWLOCALS If set, a new dict will be created for the frame’s ‘f_locals’ when the code object is executed. -- Data: inspect.CO_VARARGS The code object has a variable positional parameter (‘*args’-like). -- Data: inspect.CO_VARKEYWORDS The code object has a variable keyword parameter (‘**kwargs’-like). -- Data: inspect.CO_NESTED The flag is set when the code object is a nested function. -- Data: inspect.CO_GENERATOR The flag is set when the code object is a generator function, i.e. a generator object is returned when the code object is executed. -- Data: inspect.CO_NOFREE The flag is set if there are no free or cell variables. -- Data: inspect.CO_COROUTINE The flag is set when the code object is a coroutine function. When the code object is executed it returns a coroutine object. See PEP 492(1) for more details. New in version 3.5. -- Data: inspect.CO_ITERABLE_COROUTINE The flag is used to transform generators into generator-based coroutines. Generator objects with this flag can be used in ‘await’ expression, and can ‘yield from’ coroutine objects. See PEP 492(2) for more details. New in version 3.5. -- Data: inspect.CO_ASYNC_GENERATOR The flag is set when the code object is an asynchronous generator function. When the code object is executed it returns an asynchronous generator object. See PEP 525(3) for more details. New in version 3.6. Note: The flags are specific to CPython, and may not be defined in other Python implementations. Furthermore, the flags are an implementation detail, and can be removed or deprecated in future Python releases. It’s recommended to use public APIs from the *note inspect: a0. module for any introspection needs. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0492 (2) https://www.python.org/dev/peps/pep-0492 (3) https://www.python.org/dev/peps/pep-0525  File: python.info, Node: Command Line Interface<3>, Prev: Code Objects Bit Flags, Up: inspect — Inspect live objects 5.29.13.9 Command Line Interface ................................ The *note inspect: a0. module also provides a basic introspection capability from the command line. By default, accepts the name of a module and prints the source of that module. A class or function within the module can be printed instead by appended a colon and the qualified name of the target object. -- Program Option: --details Print information about the specified object rather than the source code  File: python.info, Node: site — Site-specific configuration hook, Prev: inspect — Inspect live objects, Up: Python Runtime Services 5.29.14 ‘site’ — Site-specific configuration hook ------------------------------------------------- `Source code:' Lib/site.py(1) __________________________________________________________________ `This module is automatically imported during initialization.' The automatic import can be suppressed using the interpreter’s *note -S: b24. option. Importing this module will append site-specific paths to the module search path and add a few builtins, unless *note -S: b24. was used. In that case, this module can be safely imported with no automatic modifications to the module search path or additions to the builtins. To explicitly trigger the usual site-specific additions, call the *note site.main(): fe2. function. Changed in version 3.3: Importing the module used to trigger paths manipulation even when using *note -S: b24. It starts by constructing up to four directories from a head and a tail part. For the head part, it uses ‘sys.prefix’ and ‘sys.exec_prefix’; empty heads are skipped. For the tail part, it uses the empty string and then ‘lib/site-packages’ (on Windows) or ‘lib/python`X.Y'/site-packages’ (on Unix and Macintosh). For each of the distinct head-tail combinations, it sees if it refers to an existing directory, and if so, adds it to ‘sys.path’ and also inspects the newly added path for configuration files. Changed in version 3.5: Support for the “site-python” directory has been removed. If a file named “pyvenv.cfg” exists one directory above sys.executable, sys.prefix and sys.exec_prefix are set to that directory and it is also checked for site-packages (sys.base_prefix and sys.base_exec_prefix will always be the “real” prefixes of the Python installation). If “pyvenv.cfg” (a bootstrap configuration file) contains the key “include-system-site-packages” set to anything other than “true” (case-insensitive), the system-level prefixes will not be searched for site-packages; otherwise they will. A path configuration file is a file whose name has the form ‘`name'.pth’ and exists in one of the four directories mentioned above; its contents are additional items (one per line) to be added to ‘sys.path’. Non-existing items are never added to ‘sys.path’, and no check is made that the item refers to a directory rather than a file. No item is added to ‘sys.path’ more than once. Blank lines and lines beginning with ‘#’ are skipped. Lines starting with ‘import’ (followed by space or tab) are executed. Note: An executable line in a ‘.pth’ file is run at every Python startup, regardless of whether a particular module is actually going to be used. Its impact should thus be kept to a minimum. The primary intended purpose of executable lines is to make the corresponding module(s) importable (load 3rd-party import hooks, adjust ‘PATH’ etc). Any other initialization is supposed to be done upon a module’s actual import, if and when it happens. Limiting a code chunk to a single line is a deliberate measure to discourage putting anything more complex here. For example, suppose ‘sys.prefix’ and ‘sys.exec_prefix’ are set to ‘/usr/local’. The Python X.Y library is then installed in ‘/usr/local/lib/python`X.Y'’. Suppose this has a subdirectory ‘/usr/local/lib/python`X.Y'/site-packages’ with three subsubdirectories, ‘foo’, ‘bar’ and ‘spam’, and two path configuration files, ‘foo.pth’ and ‘bar.pth’. Assume ‘foo.pth’ contains the following: # foo package configuration foo bar bletch and ‘bar.pth’ contains: # bar package configuration bar Then the following version-specific directories are added to ‘sys.path’, in this order: /usr/local/lib/pythonX.Y/site-packages/bar /usr/local/lib/pythonX.Y/site-packages/foo Note that ‘bletch’ is omitted because it doesn’t exist; the ‘bar’ directory precedes the ‘foo’ directory because ‘bar.pth’ comes alphabetically before ‘foo.pth’; and ‘spam’ is omitted because it is not mentioned in either path configuration file. After these path manipulations, an attempt is made to import a module named ‘sitecustomize’, which can perform arbitrary site-specific customizations. It is typically created by a system administrator in the site-packages directory. If this import fails with an *note ImportError: 334. or its subclass exception, and the exception’s ‘name’ attribute equals to ‘'sitecustomize'’, it is silently ignored. If Python is started without output streams available, as with ‘pythonw.exe’ on Windows (which is used by default to start IDLE), attempted output from ‘sitecustomize’ is ignored. Any other exception causes a silent and perhaps mysterious failure of the process. After this, an attempt is made to import a module named ‘usercustomize’, which can perform arbitrary user-specific customizations, if *note ENABLE_USER_SITE: 343b. is true. This file is intended to be created in the user site-packages directory (see below), which is part of ‘sys.path’ unless disabled by *note -s: d15. If this import fails with an *note ImportError: 334. or its subclass exception, and the exception’s ‘name’ attribute equals to ‘'usercustomize'’, it is silently ignored. Note that for some non-Unix systems, ‘sys.prefix’ and ‘sys.exec_prefix’ are empty, and the path manipulations are skipped; however the import of ‘sitecustomize’ and ‘usercustomize’ is still attempted. * Menu: * Readline configuration:: * Module contents: Module contents<3>. * Command Line Interface: Command Line Interface<4>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/site.py  File: python.info, Node: Readline configuration, Next: Module contents<3>, Up: site — Site-specific configuration hook 5.29.14.1 Readline configuration ................................ On systems that support *note readline: de, this module will also import and configure the *note rlcompleter: e1. module, if Python is started in *note interactive mode: 8e3. and without the *note -S: b24. option. The default behavior is enable tab-completion and to use ‘~/.python_history’ as the history save file. To disable it, delete (or override) the *note sys.__interactivehook__: 8e4. attribute in your ‘sitecustomize’ or ‘usercustomize’ module or your *note PYTHONSTARTUP: 8e5. file. Changed in version 3.4: Activation of rlcompleter and history was made automatic.  File: python.info, Node: Module contents<3>, Next: Command Line Interface<4>, Prev: Readline configuration, Up: site — Site-specific configuration hook 5.29.14.2 Module contents ......................... -- Data: site.PREFIXES A list of prefixes for site-packages directories. -- Data: site.ENABLE_USER_SITE Flag showing the status of the user site-packages directory. ‘True’ means that it is enabled and was added to ‘sys.path’. ‘False’ means that it was disabled by user request (with *note -s: d15. or *note PYTHONNOUSERSITE: d16.). ‘None’ means it was disabled for security reasons (mismatch between user or group id and effective id) or by an administrator. -- Data: site.USER_SITE Path to the user site-packages for the running Python. Can be ‘None’ if *note getusersitepackages(): bd5. hasn’t been called yet. Default value is ‘~/.local/lib/python`X.Y'/site-packages’ for UNIX and non-framework Mac OS X builds, ‘~/Library/Python/`X.Y'/lib/python/site-packages’ for Mac framework builds, and ‘`%APPDATA%'\Python\Python`XY'\site-packages’ on Windows. This directory is a site directory, which means that ‘.pth’ files in it will be processed. -- Data: site.USER_BASE Path to the base directory for the user site-packages. Can be ‘None’ if *note getuserbase(): bd4. hasn’t been called yet. Default value is ‘~/.local’ for UNIX and Mac OS X non-framework builds, ‘~/Library/Python/`X.Y'’ for Mac framework builds, and ‘`%APPDATA%'\Python’ for Windows. This value is used by Distutils to compute the installation directories for scripts, data files, Python modules, etc. for the *note user installation scheme: ff4. See also *note PYTHONUSERBASE: d14. -- Function: site.main () Adds all the standard site-specific directories to the module search path. This function is called automatically when this module is imported, unless the Python interpreter was started with the *note -S: b24. flag. Changed in version 3.3: This function used to be called unconditionally. -- Function: site.addsitedir (sitedir, known_paths=None) Add a directory to sys.path and process its ‘.pth’ files. Typically used in ‘sitecustomize’ or ‘usercustomize’ (see above). -- Function: site.getsitepackages () Return a list containing all global site-packages directories. New in version 3.2. -- Function: site.getuserbase () Return the path of the user base directory, *note USER_BASE: ff3. If it is not initialized yet, this function will also set it, respecting *note PYTHONUSERBASE: d14. New in version 3.2. -- Function: site.getusersitepackages () Return the path of the user-specific site-packages directory, *note USER_SITE: fe1. If it is not initialized yet, this function will also set it, respecting *note USER_BASE: ff3. To determine if the user-specific site-packages was added to ‘sys.path’ *note ENABLE_USER_SITE: 343b. should be used. New in version 3.2.  File: python.info, Node: Command Line Interface<4>, Prev: Module contents<3>, Up: site — Site-specific configuration hook 5.29.14.3 Command Line Interface ................................ The *note site: eb. module also provides a way to get the user directories from the command line: $ python3 -m site --user-site /home/user/.local/lib/python3.3/site-packages If it is called without arguments, it will print the contents of *note sys.path: 488. on the standard output, followed by the value of *note USER_BASE: ff3. and whether the directory exists, then the same thing for *note USER_SITE: fe1, and finally the value of *note ENABLE_USER_SITE: 343b. -- Program Option: --user-base Print the path to the user base directory. -- Program Option: --user-site Print the path to the user site-packages directory. If both options are given, user base and user site will be printed (always in this order), separated by *note os.pathsep: ff0. If any option is given, the script will exit with one of these values: ‘0’ if the user site-packages directory is enabled, ‘1’ if it was disabled by the user, ‘2’ if it is disabled for security reasons or by an administrator, and a value greater than 2 if there is an error. See also ........ PEP 370(1) – Per user site-packages directory ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0370  File: python.info, Node: Custom Python Interpreters, Next: Importing Modules, Prev: Python Runtime Services, Up: The Python Standard Library 5.30 Custom Python Interpreters =============================== The modules described in this chapter allow writing interfaces similar to Python’s interactive interpreter. If you want a Python interpreter that supports some special feature in addition to the Python language, you should look at the *note code: 1b. module. (The *note codeop: 1d. module is lower-level, used to support compiling a possibly-incomplete chunk of Python code.) The full list of modules described in this chapter is: * Menu: * code — Interpreter base classes:: * codeop — Compile Python code::  File: python.info, Node: code — Interpreter base classes, Next: codeop — Compile Python code, Up: Custom Python Interpreters 5.30.1 ‘code’ — Interpreter base classes ---------------------------------------- `Source code:' Lib/code.py(1) __________________________________________________________________ The ‘code’ module provides facilities to implement read-eval-print loops in Python. Two classes and convenience functions are included which can be used to build applications which provide an interactive interpreter prompt. -- Class: code.InteractiveInterpreter (locals=None) This class deals with parsing and interpreter state (the user’s namespace); it does not deal with input buffering or prompting or input file naming (the filename is always passed in explicitly). The optional `locals' argument specifies the dictionary in which code will be executed; it defaults to a newly created dictionary with key ‘'__name__'’ set to ‘'__console__'’ and key ‘'__doc__'’ set to ‘None’. -- Class: code.InteractiveConsole (locals=None, filename="<console>") Closely emulate the behavior of the interactive Python interpreter. This class builds on *note InteractiveInterpreter: 3449. and adds prompting using the familiar ‘sys.ps1’ and ‘sys.ps2’, and input buffering. -- Function: code.interact (banner=None, readfunc=None, local=None, exitmsg=None) Convenience function to run a read-eval-print loop. This creates a new instance of *note InteractiveConsole: 14a9. and sets `readfunc' to be used as the *note InteractiveConsole.raw_input(): 344b. method, if provided. If `local' is provided, it is passed to the *note InteractiveConsole: 14a9. constructor for use as the default namespace for the interpreter loop. The *note interact(): 344a. method of the instance is then run with `banner' and `exitmsg' passed as the banner and exit message to use, if provided. The console object is discarded after use. Changed in version 3.6: Added `exitmsg' parameter. -- Function: code.compile_command (source, filename="<input>", symbol="single") This function is useful for programs that want to emulate Python’s interpreter main loop (a.k.a. the read-eval-print loop). The tricky part is to determine when the user has entered an incomplete command that can be completed by entering more text (as opposed to a complete command or a syntax error). This function `almost' always makes the same decision as the real interpreter main loop. `source' is the source string; `filename' is the optional filename from which source was read, defaulting to ‘'<input>'’; and `symbol' is the optional grammar start symbol, which should be ‘'single'’ (the default), ‘'eval'’ or ‘'exec'’. Returns a code object (the same as ‘compile(source, filename, symbol)’) if the command is complete and valid; ‘None’ if the command is incomplete; raises *note SyntaxError: 458. if the command is complete and contains a syntax error, or raises *note OverflowError: 960. or *note ValueError: 1fb. if the command contains an invalid literal. * Menu: * Interactive Interpreter Objects:: * Interactive Console Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/code.py  File: python.info, Node: Interactive Interpreter Objects, Next: Interactive Console Objects, Up: code — Interpreter base classes 5.30.1.1 Interactive Interpreter Objects ........................................ -- Method: InteractiveInterpreter.runsource (source, filename="<input>", symbol="single") Compile and run some source in the interpreter. Arguments are the same as for *note compile_command(): 344c.; the default for `filename' is ‘'<input>'’, and for `symbol' is ‘'single'’. One of several things can happen: * The input is incorrect; *note compile_command(): 344c. raised an exception (*note SyntaxError: 458. or *note OverflowError: 960.). A syntax traceback will be printed by calling the *note showsyntaxerror(): 3450. method. *note runsource(): 344f. returns ‘False’. * The input is incomplete, and more input is required; *note compile_command(): 344c. returned ‘None’. *note runsource(): 344f. returns ‘True’. * The input is complete; *note compile_command(): 344c. returned a code object. The code is executed by calling the *note runcode(): 3451. (which also handles run-time exceptions, except for *note SystemExit: 5fc.). *note runsource(): 344f. returns ‘False’. The return value can be used to decide whether to use ‘sys.ps1’ or ‘sys.ps2’ to prompt the next line. -- Method: InteractiveInterpreter.runcode (code) Execute a code object. When an exception occurs, *note showtraceback(): 6a7. is called to display a traceback. All exceptions are caught except *note SystemExit: 5fc, which is allowed to propagate. A note about *note KeyboardInterrupt: 197.: this exception may occur elsewhere in this code, and may not always be caught. The caller should be prepared to deal with it. -- Method: InteractiveInterpreter.showsyntaxerror (filename=None) Display the syntax error that just occurred. This does not display a stack trace because there isn’t one for syntax errors. If `filename' is given, it is stuffed into the exception instead of the default filename provided by Python’s parser, because it always uses ‘'<string>'’ when reading from a string. The output is written by the *note write(): 3452. method. -- Method: InteractiveInterpreter.showtraceback () Display the exception that just occurred. We remove the first stack item because it is within the interpreter object implementation. The output is written by the *note write(): 3452. method. Changed in version 3.5: The full chained traceback is displayed instead of just the primary traceback. -- Method: InteractiveInterpreter.write (data) Write a string to the standard error stream (‘sys.stderr’). Derived classes should override this to provide the appropriate output handling as needed.  File: python.info, Node: Interactive Console Objects, Prev: Interactive Interpreter Objects, Up: code — Interpreter base classes 5.30.1.2 Interactive Console Objects .................................... The *note InteractiveConsole: 14a9. class is a subclass of *note InteractiveInterpreter: 3449, and so offers all the methods of the interpreter objects as well as the following additions. -- Method: InteractiveConsole.interact (banner=None, exitmsg=None) Closely emulate the interactive Python console. The optional `banner' argument specify the banner to print before the first interaction; by default it prints a banner similar to the one printed by the standard Python interpreter, followed by the class name of the console object in parentheses (so as not to confuse this with the real interpreter – since it’s so close!). The optional `exitmsg' argument specifies an exit message printed when exiting. Pass the empty string to suppress the exit message. If `exitmsg' is not given or ‘None’, a default message is printed. Changed in version 3.4: To suppress printing any banner, pass an empty string. Changed in version 3.6: Print an exit message when exiting. -- Method: InteractiveConsole.push (line) Push a line of source text to the interpreter. The line should not have a trailing newline; it may have internal newlines. The line is appended to a buffer and the interpreter’s ‘runsource()’ method is called with the concatenated contents of the buffer as source. If this indicates that the command was executed or invalid, the buffer is reset; otherwise, the command is incomplete, and the buffer is left as it was after the line was appended. The return value is ‘True’ if more input is required, ‘False’ if the line was dealt with in some way (this is the same as ‘runsource()’). -- Method: InteractiveConsole.resetbuffer () Remove any unhandled source text from the input buffer. -- Method: InteractiveConsole.raw_input (prompt="") Write a prompt and read a line. The returned line does not include the trailing newline. When the user enters the EOF key sequence, *note EOFError: c6c. is raised. The base implementation reads from ‘sys.stdin’; a subclass may replace this with a different implementation.  File: python.info, Node: codeop — Compile Python code, Prev: code — Interpreter base classes, Up: Custom Python Interpreters 5.30.2 ‘codeop’ — Compile Python code ------------------------------------- `Source code:' Lib/codeop.py(1) __________________________________________________________________ The *note codeop: 1d. module provides utilities upon which the Python read-eval-print loop can be emulated, as is done in the *note code: 1b. module. As a result, you probably don’t want to use the module directly; if you want to include such a loop in your program you probably want to use the *note code: 1b. module instead. There are two parts to this job: 1. Being able to tell if a line of input completes a Python statement: in short, telling whether to print ‘‘>>>’’ or ‘‘...’’ next. 2. Remembering which future statements the user has entered, so subsequent input can be compiled with these in effect. The *note codeop: 1d. module provides a way of doing each of these things, and a way of doing them both. To do just the former: -- Function: codeop.compile_command (source, filename="<input>", symbol="single") Tries to compile `source', which should be a string of Python code and return a code object if `source' is valid Python code. In that case, the filename attribute of the code object will be `filename', which defaults to ‘'<input>'’. Returns ‘None’ if `source' is `not' valid Python code, but is a prefix of valid Python code. If there is a problem with `source', an exception will be raised. *note SyntaxError: 458. is raised if there is invalid Python syntax, and *note OverflowError: 960. or *note ValueError: 1fb. if there is an invalid literal. The `symbol' argument determines whether `source' is compiled as a statement (‘'single'’, the default), as a sequence of statements (‘'exec'’) or as an *note expression: 3350. (‘'eval'’). Any other value will cause *note ValueError: 1fb. to be raised. Note: It is possible (but not likely) that the parser stops parsing with a successful outcome before reaching the end of the source; in this case, trailing symbols may be ignored instead of causing an error. For example, a backslash followed by two newlines may be followed by arbitrary garbage. This will be fixed once the API for the parser is better. -- Class: codeop.Compile Instances of this class have *note __call__(): 10ce. methods identical in signature to the built-in function *note compile(): 1b4, but with the difference that if the instance compiles program text containing a *note __future__: 0. statement, the instance ‘remembers’ and compiles all subsequent program texts with the statement in force. -- Class: codeop.CommandCompiler Instances of this class have *note __call__(): 10ce. methods identical in signature to *note compile_command(): 345a.; the difference is that if the instance compiles program text containing a ‘__future__’ statement, the instance ‘remembers’ and compiles all subsequent program texts with the statement in force. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/codeop.py  File: python.info, Node: Importing Modules, Next: Python Language Services, Prev: Custom Python Interpreters, Up: The Python Standard Library 5.31 Importing Modules ====================== The modules described in this chapter provide new ways to import other Python modules and hooks for customizing the import process. The full list of modules described in this chapter is: * Menu: * zipimport — Import modules from Zip archives:: * pkgutil — Package extension utility:: * modulefinder — Find modules used by a script:: * runpy — Locating and executing Python modules:: * importlib — The implementation of import:: * Using importlib.metadata: Using importlib metadata.  File: python.info, Node: zipimport — Import modules from Zip archives, Next: pkgutil — Package extension utility, Up: Importing Modules 5.31.1 ‘zipimport’ — Import modules from Zip archives ----------------------------------------------------- `Source code:' Lib/zipimport.py(1) __________________________________________________________________ This module adds the ability to import Python modules (‘*.py’, ‘*.pyc’) and packages from ZIP-format archives. It is usually not needed to use the *note zipimport: 143. module explicitly; it is automatically used by the built-in *note import: c1d. mechanism for *note sys.path: 488. items that are paths to ZIP archives. Typically, *note sys.path: 488. is a list of directory names as strings. This module also allows an item of *note sys.path: 488. to be a string naming a ZIP file archive. The ZIP archive can contain a subdirectory structure to support package imports, and a path within the archive can be specified to only import from a subdirectory. For example, the path ‘example.zip/lib/’ would only import from the ‘lib/’ subdirectory within the archive. Any files may be present in the ZIP archive, but only files ‘.py’ and ‘.pyc’ are available for import. ZIP import of dynamic modules (‘.pyd’, ‘.so’) is disallowed. Note that if an archive only contains ‘.py’ files, Python will not attempt to modify the archive by adding the corresponding ‘.pyc’ file, meaning that if a ZIP archive doesn’t contain ‘.pyc’ files, importing may be rather slow. Changed in version 3.8: Previously, ZIP archives with an archive comment were not supported. See also ........ PKZIP Application Note(2) Documentation on the ZIP file format by Phil Katz, the creator of the format and algorithms used. PEP 273(3) - Import Modules from Zip Archives Written by James C. Ahlstrom, who also provided an implementation. Python 2.3 follows the specification in PEP 273(4), but uses an implementation written by Just van Rossum that uses the import hooks described in PEP 302(5). PEP 302(6) - New Import Hooks The PEP to add the import hooks that help this module work. This module defines an exception: -- Exception: zipimport.ZipImportError Exception raised by zipimporter objects. It’s a subclass of *note ImportError: 334, so it can be caught as *note ImportError: 334, too. * Menu: * zipimporter Objects:: * Examples: Examples<28>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/zipimport.py (2) https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT (3) https://www.python.org/dev/peps/pep-0273 (4) https://www.python.org/dev/peps/pep-0273 (5) https://www.python.org/dev/peps/pep-0302 (6) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: zipimporter Objects, Next: Examples<28>, Up: zipimport — Import modules from Zip archives 5.31.1.1 zipimporter Objects ............................ *note zipimporter: 3465. is the class for importing ZIP files. -- Class: zipimport.zipimporter (archivepath) Create a new zipimporter instance. `archivepath' must be a path to a ZIP file, or to a specific path within a ZIP file. For example, an `archivepath' of ‘foo/bar.zip/lib’ will look for modules in the ‘lib’ directory inside the ZIP file ‘foo/bar.zip’ (provided that it exists). *note ZipImportError: 3462. is raised if `archivepath' doesn’t point to a valid ZIP archive. -- Method: find_module (fullname[, path]) Search for a module specified by `fullname'. `fullname' must be the fully qualified (dotted) module name. It returns the zipimporter instance itself if the module was found, or *note None: 157. if it wasn’t. The optional `path' argument is ignored—it’s there for compatibility with the importer protocol. -- Method: get_code (fullname) Return the code object for the specified module. Raise *note ZipImportError: 3462. if the module couldn’t be found. -- Method: get_data (pathname) Return the data associated with `pathname'. Raise *note OSError: 1d3. if the file wasn’t found. Changed in version 3.3: *note IOError: 992. used to be raised instead of *note OSError: 1d3. -- Method: get_filename (fullname) Return the value ‘__file__’ would be set to if the specified module was imported. Raise *note ZipImportError: 3462. if the module couldn’t be found. New in version 3.1. -- Method: get_source (fullname) Return the source code for the specified module. Raise *note ZipImportError: 3462. if the module couldn’t be found, return *note None: 157. if the archive does contain the module, but has no source for it. -- Method: is_package (fullname) Return ‘True’ if the module specified by `fullname' is a package. Raise *note ZipImportError: 3462. if the module couldn’t be found. -- Method: load_module (fullname) Load the module specified by `fullname'. `fullname' must be the fully qualified (dotted) module name. It returns the imported module, or raises *note ZipImportError: 3462. if it wasn’t found. -- Attribute: archive The file name of the importer’s associated ZIP file, without a possible subpath. -- Attribute: prefix The subpath within the ZIP file where modules are searched. This is the empty string for zipimporter objects which point to the root of the ZIP file. The *note archive: 346d. and *note prefix: 346e. attributes, when combined with a slash, equal the original `archivepath' argument given to the *note zipimporter: 3465. constructor.  File: python.info, Node: Examples<28>, Prev: zipimporter Objects, Up: zipimport — Import modules from Zip archives 5.31.1.2 Examples ................. Here is an example that imports a module from a ZIP archive - note that the *note zipimport: 143. module is not explicitly used. $ unzip -l example.zip Archive: example.zip Length Date Time Name -------- ---- ---- ---- 8467 11-26-02 22:30 jwzthreading.py -------- ------- 8467 1 file $ ./python Python 2.3 (#1, Aug 1 2003, 19:54:32) >>> import sys >>> sys.path.insert(0, 'example.zip') # Add .zip file to front of path >>> import jwzthreading >>> jwzthreading.__file__ 'example.zip/jwzthreading.py'  File: python.info, Node: pkgutil — Package extension utility, Next: modulefinder — Find modules used by a script, Prev: zipimport — Import modules from Zip archives, Up: Importing Modules 5.31.2 ‘pkgutil’ — Package extension utility -------------------------------------------- `Source code:' Lib/pkgutil.py(1) __________________________________________________________________ This module provides utilities for the import system, in particular package support. -- Class: pkgutil.ModuleInfo (module_finder, name, ispkg) A namedtuple that holds a brief summary of a module’s info. New in version 3.6. -- Function: pkgutil.extend_path (path, name) Extend the search path for the modules which comprise a package. Intended use is to place the following code in a package’s ‘__init__.py’: from pkgutil import extend_path __path__ = extend_path(__path__, __name__) This will add to the package’s ‘__path__’ all subdirectories of directories on ‘sys.path’ named after the package. This is useful if one wants to distribute different parts of a single logical package as multiple directories. It also looks for ‘*.pkg’ files beginning where ‘*’ matches the `name' argument. This feature is similar to ‘*.pth’ files (see the *note site: eb. module for more information), except that it doesn’t special-case lines starting with ‘import’. A ‘*.pkg’ file is trusted at face value: apart from checking for duplicates, all entries found in a ‘*.pkg’ file are added to the path, regardless of whether they exist on the filesystem. (This is a feature.) If the input path is not a list (as is the case for frozen packages) it is returned unchanged. The input path is not modified; an extended copy is returned. Items are only appended to the copy at the end. It is assumed that *note sys.path: 488. is a sequence. Items of *note sys.path: 488. that are not strings referring to existing directories are ignored. Unicode items on *note sys.path: 488. that cause errors when used as filenames may cause this function to raise an exception (in line with *note os.path.isdir(): 1f8. behavior). -- Class: pkgutil.ImpImporter (dirname=None) PEP 302(2) Finder that wraps Python’s “classic” import algorithm. If `dirname' is a string, a PEP 302(3) finder is created that searches that directory. If `dirname' is ‘None’, a PEP 302(4) finder is created that searches the current *note sys.path: 488, plus any modules that are frozen or built-in. Note that *note ImpImporter: 3474. does not currently support being used by placement on *note sys.meta_path: 5e6. Deprecated since version 3.3: This emulation is no longer needed, as the standard import mechanism is now fully PEP 302(5) compliant and available in *note importlib: 9b. -- Class: pkgutil.ImpLoader (fullname, file, filename, etc) *note Loader: 1160. that wraps Python’s “classic” import algorithm. Deprecated since version 3.3: This emulation is no longer needed, as the standard import mechanism is now fully PEP 302(6) compliant and available in *note importlib: 9b. -- Function: pkgutil.find_loader (fullname) Retrieve a module *note loader: 1160. for the given `fullname'. This is a backwards compatibility wrapper around *note importlib.util.find_spec(): 938. that converts most failures to *note ImportError: 334. and only returns the loader rather than the full ‘ModuleSpec’. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(7) import emulation. Changed in version 3.4: Updated to be based on PEP 451(8) -- Function: pkgutil.get_importer (path_item) Retrieve a *note finder: 115f. for the given `path_item'. The returned finder is cached in *note sys.path_importer_cache: 49d. if it was newly created by a path hook. The cache (or part of it) can be cleared manually if a rescan of *note sys.path_hooks: 95c. is necessary. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(9) import emulation. -- Function: pkgutil.get_loader (module_or_name) Get a *note loader: 1160. object for `module_or_name'. If the module or package is accessible via the normal import mechanism, a wrapper around the relevant part of that machinery is returned. Returns ‘None’ if the module cannot be found or imported. If the named module is not already imported, its containing package (if any) is imported, in order to establish the package ‘__path__’. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(10) import emulation. Changed in version 3.4: Updated to be based on PEP 451(11) -- Function: pkgutil.iter_importers (fullname='') Yield *note finder: 115f. objects for the given module name. If fullname contains a ‘.’, the finders will be for the package containing fullname, otherwise they will be all registered top level finders (i.e. those on both sys.meta_path and sys.path_hooks). If the named module is in a package, that package is imported as a side effect of invoking this function. If no module name is specified, all top level finders are produced. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(12) import emulation. -- Function: pkgutil.iter_modules (path=None, prefix='') Yields *note ModuleInfo: 60d. for all submodules on `path', or, if `path' is ‘None’, all top-level modules on ‘sys.path’. `path' should be either ‘None’ or a list of paths to look for modules in. `prefix' is a string to output on the front of every module name on output. Note: Only works for a *note finder: 115f. which defines an ‘iter_modules()’ method. This interface is non-standard, so the module also provides implementations for *note importlib.machinery.FileFinder: 9b6. and *note zipimport.zipimporter: 3465. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(13) import emulation. -- Function: pkgutil.walk_packages (path=None, prefix='', onerror=None) Yields *note ModuleInfo: 60d. for all modules recursively on `path', or, if `path' is ‘None’, all accessible modules. `path' should be either ‘None’ or a list of paths to look for modules in. `prefix' is a string to output on the front of every module name on output. Note that this function must import all `packages' (`not' all modules!) on the given `path', in order to access the ‘__path__’ attribute to find submodules. `onerror' is a function which gets called with one argument (the name of the package which was being imported) if any exception occurs while trying to import a package. If no `onerror' function is supplied, *note ImportError: 334.s are caught and ignored, while all other exceptions are propagated, terminating the search. Examples: # list all modules python can access walk_packages() # list all submodules of ctypes walk_packages(ctypes.__path__, ctypes.__name__ + '.') Note: Only works for a *note finder: 115f. which defines an ‘iter_modules()’ method. This interface is non-standard, so the module also provides implementations for *note importlib.machinery.FileFinder: 9b6. and *note zipimport.zipimporter: 3465. Changed in version 3.3: Updated to be based directly on *note importlib: 9b. rather than relying on the package internal PEP 302(14) import emulation. -- Function: pkgutil.get_data (package, resource) Get a resource from a package. This is a wrapper for the *note loader: 1160. *note get_data: 347a. API. The `package' argument should be the name of a package, in standard module format (‘foo.bar’). The `resource' argument should be in the form of a relative filename, using ‘/’ as the path separator. The parent directory name ‘..’ is not allowed, and nor is a rooted name (starting with a ‘/’). The function returns a binary string that is the contents of the specified resource. For packages located in the filesystem, which have already been imported, this is the rough equivalent of: d = os.path.dirname(sys.modules[package].__file__) data = open(os.path.join(d, resource), 'rb').read() If the package cannot be located or loaded, or it uses a *note loader: 1160. which does not support *note get_data: 347a, then ‘None’ is returned. In particular, the *note loader: 1160. for *note namespace packages: 1158. does not support *note get_data: 347a. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pkgutil.py (2) https://www.python.org/dev/peps/pep-0302 (3) https://www.python.org/dev/peps/pep-0302 (4) https://www.python.org/dev/peps/pep-0302 (5) https://www.python.org/dev/peps/pep-0302 (6) https://www.python.org/dev/peps/pep-0302 (7) https://www.python.org/dev/peps/pep-0302 (8) https://www.python.org/dev/peps/pep-0451 (9) https://www.python.org/dev/peps/pep-0302 (10) https://www.python.org/dev/peps/pep-0302 (11) https://www.python.org/dev/peps/pep-0451 (12) https://www.python.org/dev/peps/pep-0302 (13) https://www.python.org/dev/peps/pep-0302 (14) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: modulefinder — Find modules used by a script, Next: runpy — Locating and executing Python modules, Prev: pkgutil — Package extension utility, Up: Importing Modules 5.31.3 ‘modulefinder’ — Find modules used by a script ----------------------------------------------------- `Source code:' Lib/modulefinder.py(1) __________________________________________________________________ This module provides a *note ModuleFinder: 347d. class that can be used to determine the set of modules imported by a script. ‘modulefinder.py’ can also be run as a script, giving the filename of a Python script as its argument, after which a report of the imported modules will be printed. -- Function: modulefinder.AddPackagePath (pkg_name, path) Record that the package named `pkg_name' can be found in the specified `path'. -- Function: modulefinder.ReplacePackage (oldname, newname) Allows specifying that the module named `oldname' is in fact the package named `newname'. -- Class: modulefinder.ModuleFinder (path=None, debug=0, excludes=[], replace_paths=[]) This class provides *note run_script(): 3480. and *note report(): 3481. methods to determine the set of modules imported by a script. `path' can be a list of directories to search for modules; if not specified, ‘sys.path’ is used. `debug' sets the debugging level; higher values make the class print debugging messages about what it’s doing. `excludes' is a list of module names to exclude from the analysis. `replace_paths' is a list of ‘(oldpath, newpath)’ tuples that will be replaced in module paths. -- Method: report () Print a report to standard output that lists the modules imported by the script and their paths, as well as modules that are missing or seem to be missing. -- Method: run_script (pathname) Analyze the contents of the `pathname' file, which must contain Python code. -- Attribute: modules A dictionary mapping module names to modules. See *note Example usage of ModuleFinder: 3483. * Menu: * Example usage of ModuleFinder:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/modulefinder.py  File: python.info, Node: Example usage of ModuleFinder, Up: modulefinder — Find modules used by a script 5.31.3.1 Example usage of ‘ModuleFinder’ ........................................ The script that is going to get analyzed later on (bacon.py): import re, itertools try: import baconhameggs except ImportError: pass try: import guido.python.ham except ImportError: pass The script that will output the report of bacon.py: from modulefinder import ModuleFinder finder = ModuleFinder() finder.run_script('bacon.py') print('Loaded modules:') for name, mod in finder.modules.items(): print('%s: ' % name, end='') print(','.join(list(mod.globalnames.keys())[:3])) print('-'*50) print('Modules not imported:') print('\n'.join(finder.badmodules.keys())) Sample output (may vary depending on the architecture): Loaded modules: _types: copyreg: _inverted_registry,_slotnames,__all__ sre_compile: isstring,_sre,_optimize_unicode _sre: sre_constants: REPEAT_ONE,makedict,AT_END_LINE sys: re: __module__,finditer,_expand itertools: __main__: re,itertools,baconhameggs sre_parse: _PATTERNENDERS,SRE_FLAG_UNICODE array: types: __module__,IntType,TypeType --------------------------------------------------- Modules not imported: guido.python.ham baconhameggs  File: python.info, Node: runpy — Locating and executing Python modules, Next: importlib — The implementation of import, Prev: modulefinder — Find modules used by a script, Up: Importing Modules 5.31.4 ‘runpy’ — Locating and executing Python modules ------------------------------------------------------ `Source code:' Lib/runpy.py(1) __________________________________________________________________ The *note runpy: e2. module is used to locate and run Python modules without importing them first. Its main use is to implement the *note -m: 337. command line switch that allows scripts to be located using the Python module namespace rather than the filesystem. Note that this is `not' a sandbox module - all code is executed in the current process, and any side effects (such as cached imports of other modules) will remain in place after the functions have returned. Furthermore, any functions and classes defined by the executed code are not guaranteed to work correctly after a *note runpy: e2. function has returned. If that limitation is not acceptable for a given use case, *note importlib: 9b. is likely to be a more suitable choice than this module. The *note runpy: e2. module provides two functions: -- Function: runpy.run_module (mod_name, init_globals=None, run_name=None, alter_sys=False) Execute the code of the specified module and return the resulting module globals dictionary. The module’s code is first located using the standard import mechanism (refer to PEP 302(2) for details) and then executed in a fresh module namespace. The `mod_name' argument should be an absolute module name. If the module name refers to a package rather than a normal module, then that package is imported and the ‘__main__’ submodule within that package is then executed and the resulting module globals dictionary returned. The optional dictionary argument `init_globals' may be used to pre-populate the module’s globals dictionary before the code is executed. The supplied dictionary will not be modified. If any of the special global variables below are defined in the supplied dictionary, those definitions are overridden by *note run_module(): fd3. The special global variables ‘__name__’, ‘__spec__’, ‘__file__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ are set in the globals dictionary before the module code is executed (Note that this is a minimal set of variables - other variables may be set implicitly as an interpreter implementation detail). ‘__name__’ is set to `run_name' if this optional argument is not *note None: 157, to ‘mod_name + '.__main__'’ if the named module is a package and to the `mod_name' argument otherwise. ‘__spec__’ will be set appropriately for the `actually' imported module (that is, ‘__spec__.name’ will always be `mod_name' or ‘mod_name + '.__main__’, never `run_name'). ‘__file__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ are *note set as normal: 1167. based on the module spec. If the argument `alter_sys' is supplied and evaluates to *note True: 499, then ‘sys.argv[0]’ is updated with the value of ‘__file__’ and ‘sys.modules[__name__]’ is updated with a temporary module object for the module being executed. Both ‘sys.argv[0]’ and ‘sys.modules[__name__]’ are restored to their original values before the function returns. Note that this manipulation of *note sys: fd. is not thread-safe. Other threads may see the partially initialised module, as well as the altered list of arguments. It is recommended that the *note sys: fd. module be left alone when invoking this function from threaded code. See also ........ The *note -m: 337. option offering equivalent functionality from the command line. Changed in version 3.1: Added ability to execute packages by looking for a ‘__main__’ submodule. Changed in version 3.2: Added ‘__cached__’ global variable (see PEP 3147(3)). Changed in version 3.4: Updated to take advantage of the module spec feature added by PEP 451(4). This allows ‘__cached__’ to be set correctly for modules run this way, as well as ensuring the real module name is always accessible as ‘__spec__.name’. -- Function: runpy.run_path (file_path, init_globals=None, run_name=None) Execute the code at the named filesystem location and return the resulting module globals dictionary. As with a script name supplied to the CPython command line, the supplied path may refer to a Python source file, a compiled bytecode file or a valid sys.path entry containing a ‘__main__’ module (e.g. a zipfile containing a top-level ‘__main__.py’ file). For a simple script, the specified code is simply executed in a fresh module namespace. For a valid sys.path entry (typically a zipfile or directory), the entry is first added to the beginning of ‘sys.path’. The function then looks for and executes a *note __main__: 1. module using the updated path. Note that there is no special protection against invoking an existing *note __main__: 1. entry located elsewhere on ‘sys.path’ if there is no such module at the specified location. The optional dictionary argument `init_globals' may be used to pre-populate the module’s globals dictionary before the code is executed. The supplied dictionary will not be modified. If any of the special global variables below are defined in the supplied dictionary, those definitions are overridden by *note run_path(): cb1. The special global variables ‘__name__’, ‘__spec__’, ‘__file__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ are set in the globals dictionary before the module code is executed (Note that this is a minimal set of variables - other variables may be set implicitly as an interpreter implementation detail). ‘__name__’ is set to `run_name' if this optional argument is not *note None: 157. and to ‘'<run_path>'’ otherwise. If the supplied path directly references a script file (whether as source or as precompiled byte code), then ‘__file__’ will be set to the supplied path, and ‘__spec__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ will all be set to *note None: 157. If the supplied path is a reference to a valid sys.path entry, then ‘__spec__’ will be set appropriately for the imported ‘__main__’ module (that is, ‘__spec__.name’ will always be ‘__main__’). ‘__file__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ will be *note set as normal: 1167. based on the module spec. A number of alterations are also made to the *note sys: fd. module. Firstly, ‘sys.path’ may be altered as described above. ‘sys.argv[0]’ is updated with the value of ‘file_path’ and ‘sys.modules[__name__]’ is updated with a temporary module object for the module being executed. All modifications to items in *note sys: fd. are reverted before the function returns. Note that, unlike *note run_module(): fd3, the alterations made to *note sys: fd. are not optional in this function as these adjustments are essential to allowing the execution of sys.path entries. As the thread-safety limitations still apply, use of this function in threaded code should be either serialised with the import lock or delegated to a separate process. See also ........ *note Interface options: fd0. for equivalent functionality on the command line (‘python path/to/script’). New in version 3.2. Changed in version 3.4: Updated to take advantage of the module spec feature added by PEP 451(5). This allows ‘__cached__’ to be set correctly in the case where ‘__main__’ is imported from a valid sys.path entry rather than being executed directly. See also ........ PEP 338(6) – Executing modules as scripts PEP written and implemented by Nick Coghlan. PEP 366(7) – Main module explicit relative imports PEP written and implemented by Nick Coghlan. PEP 451(8) – A ModuleSpec Type for the Import System PEP written and implemented by Eric Snow *note Command line and environment: e9f. - CPython command line details The *note importlib.import_module(): b13. function ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/runpy.py (2) https://www.python.org/dev/peps/pep-0302 (3) https://www.python.org/dev/peps/pep-3147 (4) https://www.python.org/dev/peps/pep-0451 (5) https://www.python.org/dev/peps/pep-0451 (6) https://www.python.org/dev/peps/pep-0338 (7) https://www.python.org/dev/peps/pep-0366 (8) https://www.python.org/dev/peps/pep-0451  File: python.info, Node: importlib — The implementation of import, Next: Using importlib metadata, Prev: runpy — Locating and executing Python modules, Up: Importing Modules 5.31.5 ‘importlib’ — The implementation of ‘import’ --------------------------------------------------- New in version 3.1. `Source code:' Lib/importlib/__init__.py(1) __________________________________________________________________ * Menu: * Introduction: Introduction<12>. * Functions: Functions<10>. * importlib.abc – Abstract base classes related to import: importlib abc – Abstract base classes related to import. * importlib.resources – Resources: importlib resources – Resources. * importlib.machinery – Importers and path hooks: importlib machinery – Importers and path hooks. * importlib.util – Utility code for importers: importlib util – Utility code for importers. * Examples: Examples<29>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/importlib/__init__.py  File: python.info, Node: Introduction<12>, Next: Functions<10>, Up: importlib — The implementation of import 5.31.5.1 Introduction ..................... The purpose of the *note importlib: 9b. package is two-fold. One is to provide the implementation of the *note import: c1d. statement (and thus, by extension, the *note __import__(): 610. function) in Python source code. This provides an implementation of ‘import’ which is portable to any Python interpreter. This also provides an implementation which is easier to comprehend than one implemented in a programming language other than Python. Two, the components to implement *note import: c1d. are exposed in this package, making it easier for users to create their own custom objects (known generically as an *note importer: 1161.) to participate in the import process. See also ........ *note The import statement: c1d. The language reference for the *note import: c1d. statement. Packages specification(1) Original specification of packages. Some semantics have changed since the writing of this document (e.g. redirecting based on ‘None’ in *note sys.modules: 1152.). The *note __import__(): 9ae. function The *note import: c1d. statement is syntactic sugar for this function. PEP 235(2) Import on Case-Insensitive Platforms PEP 263(3) Defining Python Source Code Encodings PEP 302(4) New Import Hooks PEP 328(5) Imports: Multi-Line and Absolute/Relative PEP 366(6) Main module explicit relative imports PEP 420(7) Implicit namespace packages PEP 451(8) A ModuleSpec Type for the Import System PEP 488(9) Elimination of PYO files PEP 489(10) Multi-phase extension module initialization PEP 552(11) Deterministic pycs PEP 3120(12) Using UTF-8 as the Default Source Encoding PEP 3147(13) PYC Repository Directories ---------- Footnotes ---------- (1) https://www.python.org/doc/essays/packages/ (2) https://www.python.org/dev/peps/pep-0235 (3) https://www.python.org/dev/peps/pep-0263 (4) https://www.python.org/dev/peps/pep-0302 (5) https://www.python.org/dev/peps/pep-0328 (6) https://www.python.org/dev/peps/pep-0366 (7) https://www.python.org/dev/peps/pep-0420 (8) https://www.python.org/dev/peps/pep-0451 (9) https://www.python.org/dev/peps/pep-0488 (10) https://www.python.org/dev/peps/pep-0489 (11) https://www.python.org/dev/peps/pep-0552 (12) https://www.python.org/dev/peps/pep-3120 (13) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: Functions<10>, Next: importlib abc – Abstract base classes related to import, Prev: Introduction<12>, Up: importlib — The implementation of import 5.31.5.2 Functions .................. -- Function: importlib.__import__ (name, globals=None, locals=None, fromlist=(), level=0) An implementation of the built-in *note __import__(): 610. function. Note: Programmatic importing of modules should use *note import_module(): b13. instead of this function. -- Function: importlib.import_module (name, package=None) Import a module. The `name' argument specifies what module to import in absolute or relative terms (e.g. either ‘pkg.mod’ or ‘..mod’). If the name is specified in relative terms, then the `package' argument must be set to the name of the package which is to act as the anchor for resolving the package name (e.g. ‘import_module('..mod', 'pkg.subpkg')’ will import ‘pkg.mod’). The *note import_module(): b13. function acts as a simplifying wrapper around *note importlib.__import__(): 9ae. This means all semantics of the function are derived from *note importlib.__import__(): 9ae. The most important difference between these two functions is that *note import_module(): b13. returns the specified package or module (e.g. ‘pkg.mod’), while *note __import__(): 610. returns the top-level package or module (e.g. ‘pkg’). If you are dynamically importing a module that was created since the interpreter began execution (e.g., created a Python source file), you may need to call *note invalidate_caches(): 49c. in order for the new module to be noticed by the import system. Changed in version 3.3: Parent packages are automatically imported. -- Function: importlib.find_loader (name, path=None) Find the loader for a module, optionally within the specified `path'. If the module is in *note sys.modules: 1152, then ‘sys.modules[name].__loader__’ is returned (unless the loader would be ‘None’ or is not set, in which case *note ValueError: 1fb. is raised). Otherwise a search using *note sys.meta_path: 5e6. is done. ‘None’ is returned if no loader is found. A dotted name does not have its parents implicitly imported as that requires loading them and that may not be desired. To properly import a submodule you will need to import all parent packages of the submodule and use the correct argument to `path'. New in version 3.3. Changed in version 3.4: If ‘__loader__’ is not set, raise *note ValueError: 1fb, just like when the attribute is set to ‘None’. Deprecated since version 3.4: Use *note importlib.util.find_spec(): 938. instead. -- Function: importlib.invalidate_caches () Invalidate the internal caches of finders stored at *note sys.meta_path: 5e6. If a finder implements ‘invalidate_caches()’ then it will be called to perform the invalidation. This function should be called if any modules are created/installed while your program is running to guarantee all finders will notice the new module’s existence. New in version 3.3. -- Function: importlib.reload (module) Reload a previously imported `module'. The argument must be a module object, so it must have been successfully imported before. This is useful if you have edited the module source file using an external editor and want to try out the new version without leaving the Python interpreter. The return value is the module object (which can be different if re-importing causes a different object to be placed in *note sys.modules: 1152.). When *note reload(): 399. is executed: * Python module’s code is recompiled and the module-level code re-executed, defining a new set of objects which are bound to names in the module’s dictionary by reusing the *note loader: 1160. which originally loaded the module. The ‘init’ function of extension modules is not called a second time. * As with all other objects in Python the old objects are only reclaimed after their reference counts drop to zero. * The names in the module namespace are updated to point to any new or changed objects. * Other references to the old objects (such as names external to the module) are not rebound to refer to the new objects and must be updated in each namespace where they occur if that is desired. There are a number of other caveats: When a module is reloaded, its dictionary (containing the module’s global variables) is retained. Redefinitions of names will override the old definitions, so this is generally not a problem. If the new version of a module does not define a name that was defined by the old version, the old definition remains. This feature can be used to the module’s advantage if it maintains a global table or cache of objects — with a *note try: d72. statement it can test for the table’s presence and skip its initialization if desired: try: cache except NameError: cache = {} It is generally not very useful to reload built-in or dynamically loaded modules. Reloading *note sys: fd, *note __main__: 1, *note builtins: 13. and other key modules is not recommended. In many cases extension modules are not designed to be initialized more than once, and may fail in arbitrary ways when reloaded. If a module imports objects from another module using *note from: c45. … *note import: c1d. …, calling *note reload(): 399. for the other module does not redefine the objects imported from it — one way around this is to re-execute the ‘from’ statement, another is to use ‘import’ and qualified names (`module.name') instead. If a module instantiates instances of a class, reloading the module that defines the class does not affect the method definitions of the instances — they continue to use the old class definition. The same is true for derived classes. New in version 3.4. Changed in version 3.7: *note ModuleNotFoundError: 39a. is raised when the module being reloaded lacks a ‘ModuleSpec’.  File: python.info, Node: importlib abc – Abstract base classes related to import, Next: importlib resources – Resources, Prev: Functions<10>, Up: importlib — The implementation of import 5.31.5.3 ‘importlib.abc’ – Abstract base classes related to import .................................................................. `Source code:' Lib/importlib/abc.py(1) __________________________________________________________________ The *note importlib.abc: 9c. module contains all of the core abstract base classes used by *note import: c1d. Some subclasses of the core abstract base classes are also provided to help in implementing the core ABCs. ABC hierarchy: object +-- Finder (deprecated) | +-- MetaPathFinder | +-- PathEntryFinder +-- Loader +-- ResourceLoader --------+ +-- InspectLoader | +-- ExecutionLoader --+ +-- FileLoader +-- SourceLoader -- Class: importlib.abc.Finder An abstract base class representing a *note finder: 115f. Deprecated since version 3.3: Use *note MetaPathFinder: 9b3. or *note PathEntryFinder: 9b4. instead. -- Method: abstractmethod find_module (fullname, path=None) An abstract method for finding a *note loader: 1160. for the specified module. Originally specified in PEP 302(2), this method was meant for use in *note sys.meta_path: 5e6. and in the path-based import subsystem. Changed in version 3.4: Returns ‘None’ when called instead of raising *note NotImplementedError: 60e. -- Class: importlib.abc.MetaPathFinder An abstract base class representing a *note meta path finder: 9b1. For compatibility, this is a subclass of *note Finder: 9b5. New in version 3.3. -- Method: find_spec (fullname, path, target=None) An abstract method for finding a *note spec: 3360. for the specified module. If this is a top-level import, `path' will be ‘None’. Otherwise, this is a search for a subpackage or module and `path' will be the value of *note __path__: f23. from the parent package. If a spec cannot be found, ‘None’ is returned. When passed in, ‘target’ is a module object that the finder may use to make a more educated guess about what spec to return. *note importlib.util.spec_from_loader(): 348d. may be useful for implementing concrete ‘MetaPathFinders’. New in version 3.4. -- Method: find_module (fullname, path) A legacy method for finding a *note loader: 1160. for the specified module. If this is a top-level import, `path' will be ‘None’. Otherwise, this is a search for a subpackage or module and `path' will be the value of *note __path__: f23. from the parent package. If a loader cannot be found, ‘None’ is returned. If *note find_spec(): 463. is defined, backwards-compatible functionality is provided. Changed in version 3.4: Returns ‘None’ when called instead of raising *note NotImplementedError: 60e. Can use *note find_spec(): 463. to provide functionality. Deprecated since version 3.4: Use *note find_spec(): 463. instead. -- Method: invalidate_caches () An optional method which, when called, should invalidate any internal cache used by the finder. Used by *note importlib.invalidate_caches(): 49c. when invalidating the caches of all finders on *note sys.meta_path: 5e6. Changed in version 3.4: Returns ‘None’ when called instead of ‘NotImplemented’. -- Class: importlib.abc.PathEntryFinder An abstract base class representing a *note path entry finder: 9b2. Though it bears some similarities to *note MetaPathFinder: 9b3, ‘PathEntryFinder’ is meant for use only within the path-based import subsystem provided by ‘PathFinder’. This ABC is a subclass of *note Finder: 9b5. for compatibility reasons only. New in version 3.3. -- Method: find_spec (fullname, target=None) An abstract method for finding a *note spec: 3360. for the specified module. The finder will search for the module only within the *note path entry: 1175. to which it is assigned. If a spec cannot be found, ‘None’ is returned. When passed in, ‘target’ is a module object that the finder may use to make a more educated guess about what spec to return. *note importlib.util.spec_from_loader(): 348d. may be useful for implementing concrete ‘PathEntryFinders’. New in version 3.4. -- Method: find_loader (fullname) A legacy method for finding a *note loader: 1160. for the specified module. Returns a 2-tuple of ‘(loader, portion)’ where ‘portion’ is a sequence of file system locations contributing to part of a namespace package. The loader may be ‘None’ while specifying ‘portion’ to signify the contribution of the file system locations to a namespace package. An empty list can be used for ‘portion’ to signify the loader is not part of a namespace package. If ‘loader’ is ‘None’ and ‘portion’ is the empty list then no loader or location for a namespace package were found (i.e. failure to find anything for the module). If *note find_spec(): 465. is defined then backwards-compatible functionality is provided. Changed in version 3.4: Returns ‘(None, [])’ instead of raising *note NotImplementedError: 60e. Uses *note find_spec(): 465. when available to provide functionality. Deprecated since version 3.4: Use *note find_spec(): 465. instead. -- Method: find_module (fullname) A concrete implementation of *note Finder.find_module(): 348c. which is equivalent to ‘self.find_loader(fullname)[0]’. Deprecated since version 3.4: Use *note find_spec(): 465. instead. -- Method: invalidate_caches () An optional method which, when called, should invalidate any internal cache used by the finder. Used by ‘PathFinder.invalidate_caches()’ when invalidating the caches of all cached finders. -- Class: importlib.abc.Loader An abstract base class for a *note loader: 1160. See PEP 302(3) for the exact definition for a loader. Loaders that wish to support resource reading should implement a ‘get_resource_reader(fullname)’ method as specified by *note importlib.abc.ResourceReader: 342. Changed in version 3.7: Introduced the optional ‘get_resource_reader()’ method. -- Method: create_module (spec) A method that returns the module object to use when importing a module. This method may return ‘None’, indicating that default module creation semantics should take place. New in version 3.4. Changed in version 3.5: Starting in Python 3.6, this method will not be optional when *note exec_module(): 5e4. is defined. -- Method: exec_module (module) An abstract method that executes the module in its own namespace when a module is imported or reloaded. The module should already be initialized when ‘exec_module()’ is called. When this method exists, *note create_module(): 554. must be defined. New in version 3.4. Changed in version 3.6: *note create_module(): 554. must also be defined. -- Method: load_module (fullname) A legacy method for loading a module. If the module cannot be loaded, *note ImportError: 334. is raised, otherwise the loaded module is returned. If the requested module already exists in *note sys.modules: 1152, that module should be used and reloaded. Otherwise the loader should create a new module and insert it into *note sys.modules: 1152. before any loading begins, to prevent recursion from the import. If the loader inserted a module and the load fails, it must be removed by the loader from *note sys.modules: 1152.; modules already in *note sys.modules: 1152. before the loader began execution should be left alone (see *note importlib.util.module_for_loader(): 942.). The loader should set several attributes on the module. (Note that some of these attributes can change when a module is reloaded): - *note __name__: d12. The name of the module. - *note __file__: 10d0. The path to where the module data is stored (not set for built-in modules). - *note __cached__: b32. The path to where a compiled version of the module is/should be stored (not set when the attribute would be inappropriate). - *note __path__: f23. A list of strings specifying the search path within a package. This attribute is not set on modules. - *note __package__: 955. The fully-qualified name of the package under which the module was loaded as a submodule (or the empty string for top-level modules). For packages, it is the same as *note __name__: d12. The *note importlib.util.module_for_loader(): 942. decorator can handle the details for *note __package__: 955. - *note __loader__: 956. The loader used to load the module. The *note importlib.util.module_for_loader(): 942. decorator can handle the details for *note __package__: 955. When *note exec_module(): 5e4. is available then backwards-compatible functionality is provided. Changed in version 3.4: Raise *note ImportError: 334. when called instead of *note NotImplementedError: 60e. Functionality provided when *note exec_module(): 5e4. is available. Deprecated since version 3.4: The recommended API for loading a module is *note exec_module(): 5e4. (and *note create_module(): 554.). Loaders should implement it instead of load_module(). The import machinery takes care of all the other responsibilities of load_module() when exec_module() is implemented. -- Method: module_repr (module) A legacy method which when implemented calculates and returns the given module’s repr, as a string. The module type’s default repr() will use the result of this method as appropriate. New in version 3.3. Changed in version 3.4: Made optional instead of an abstractmethod. Deprecated since version 3.4: The import machinery now takes care of this automatically. -- Class: importlib.abc.ResourceReader An *note abstract base class: b33. to provide the ability to read `resources'. From the perspective of this ABC, a `resource' is a binary artifact that is shipped within a package. Typically this is something like a data file that lives next to the ‘__init__.py’ file of the package. The purpose of this class is to help abstract out the accessing of such data files so that it does not matter if the package and its data file(s) are stored in a e.g. zip file versus on the file system. For any of methods of this class, a `resource' argument is expected to be a *note path-like object: 36a. which represents conceptually just a file name. This means that no subdirectory paths should be included in the `resource' argument. This is because the location of the package the reader is for, acts as the “directory”. Hence the metaphor for directories and file names is packages and resources, respectively. This is also why instances of this class are expected to directly correlate to a specific package (instead of potentially representing multiple packages or a module). Loaders that wish to support resource reading are expected to provide a method called ‘get_resource_reader(fullname)’ which returns an object implementing this ABC’s interface. If the module specified by fullname is not a package, this method should return *note None: 157. An object compatible with this ABC should only be returned when the specified module is a package. New in version 3.7. -- Method: abstractmethod open_resource (resource) Returns an opened, *note file-like object: 1928. for binary reading of the `resource'. If the resource cannot be found, *note FileNotFoundError: 7c0. is raised. -- Method: abstractmethod resource_path (resource) Returns the file system path to the `resource'. If the resource does not concretely exist on the file system, raise *note FileNotFoundError: 7c0. -- Method: abstractmethod is_resource (name) Returns ‘True’ if the named `name' is considered a resource. *note FileNotFoundError: 7c0. is raised if `name' does not exist. -- Method: abstractmethod contents () Returns an *note iterable: bac. of strings over the contents of the package. Do note that it is not required that all names returned by the iterator be actual resources, e.g. it is acceptable to return names for which *note is_resource(): 3492. would be false. Allowing non-resource names to be returned is to allow for situations where how a package and its resources are stored are known a priori and the non-resource names would be useful. For instance, returning subdirectory names is allowed so that when it is known that the package and resources are stored on the file system then those subdirectory names can be used directly. The abstract method returns an iterable of no items. -- Class: importlib.abc.ResourceLoader An abstract base class for a *note loader: 1160. which implements the optional PEP 302(4) protocol for loading arbitrary resources from the storage back-end. Deprecated since version 3.7: This ABC is deprecated in favour of supporting resource loading through *note importlib.abc.ResourceReader: 342. -- Method: abstractmethod get_data (path) An abstract method to return the bytes for the data located at `path'. Loaders that have a file-like storage back-end that allows storing arbitrary data can implement this abstract method to give direct access to the data stored. *note OSError: 1d3. is to be raised if the `path' cannot be found. The `path' is expected to be constructed using a module’s *note __file__: 10d0. attribute or an item from a package’s *note __path__: f23. Changed in version 3.4: Raises *note OSError: 1d3. instead of *note NotImplementedError: 60e. -- Class: importlib.abc.InspectLoader An abstract base class for a *note loader: 1160. which implements the optional PEP 302(5) protocol for loaders that inspect modules. -- Method: get_code (fullname) Return the code object for a module, or ‘None’ if the module does not have a code object (as would be the case, for example, for a built-in module). Raise an *note ImportError: 334. if loader cannot find the requested module. Note: While the method has a default implementation, it is suggested that it be overridden if possible for performance. Changed in version 3.4: No longer abstract and a concrete implementation is provided. -- Method: abstractmethod get_source (fullname) An abstract method to return the source of a module. It is returned as a text string using *note universal newlines: 5f4, translating all recognized line separators into ‘'\n'’ characters. Returns ‘None’ if no source is available (e.g. a built-in module). Raises *note ImportError: 334. if the loader cannot find the module specified. Changed in version 3.4: Raises *note ImportError: 334. instead of *note NotImplementedError: 60e. -- Method: is_package (fullname) An abstract method to return a true value if the module is a package, a false value otherwise. *note ImportError: 334. is raised if the *note loader: 1160. cannot find the module. Changed in version 3.4: Raises *note ImportError: 334. instead of *note NotImplementedError: 60e. -- Method: static source_to_code (data, path='<string>') Create a code object from Python source. The `data' argument can be whatever the *note compile(): 1b4. function supports (i.e. string or bytes). The `path' argument should be the “path” to where the source code originated from, which can be an abstract concept (e.g. location in a zip file). With the subsequent code object one can execute it in a module by running ‘exec(code, module.__dict__)’. New in version 3.4. Changed in version 3.5: Made the method static. -- Method: exec_module (module) Implementation of *note Loader.exec_module(): 5e4. New in version 3.4. -- Method: load_module (fullname) Implementation of *note Loader.load_module(): 5e3. Deprecated since version 3.4: use *note exec_module(): 93f. instead. -- Class: importlib.abc.ExecutionLoader An abstract base class which inherits from *note InspectLoader: 860. that, when implemented, helps a module to be executed as a script. The ABC represents an optional PEP 302(6) protocol. -- Method: abstractmethod get_filename (fullname) An abstract method that is to return the value of *note __file__: 10d0. for the specified module. If no path is available, *note ImportError: 334. is raised. If source code is available, then the method should return the path to the source file, regardless of whether a bytecode was used to load the module. Changed in version 3.4: Raises *note ImportError: 334. instead of *note NotImplementedError: 60e. -- Class: importlib.abc.FileLoader (fullname, path) An abstract base class which inherits from *note ResourceLoader: 466. and *note ExecutionLoader: 3495, providing concrete implementations of *note ResourceLoader.get_data(): 347a. and *note ExecutionLoader.get_filename(): 3496. The `fullname' argument is a fully resolved name of the module the loader is to handle. The `path' argument is the path to the file for the module. New in version 3.3. -- Attribute: name The name of the module the loader can handle. -- Attribute: path Path to the file of the module. -- Method: load_module (fullname) Calls super’s ‘load_module()’. Deprecated since version 3.4: Use *note Loader.exec_module(): 5e4. instead. -- Method: abstractmethod get_filename (fullname) Returns *note path: 3498. -- Method: abstractmethod get_data (path) Reads `path' as a binary file and returns the bytes from it. -- Class: importlib.abc.SourceLoader An abstract base class for implementing source (and optionally bytecode) file loading. The class inherits from both *note ResourceLoader: 466. and *note ExecutionLoader: 3495, requiring the implementation of: * *note ResourceLoader.get_data(): 347a. * *note ExecutionLoader.get_filename(): 3496. Should only return the path to the source file; sourceless loading is not supported. The abstract methods defined by this class are to add optional bytecode file support. Not implementing these optional methods (or causing them to raise *note NotImplementedError: 60e.) causes the loader to only work with source code. Implementing the methods allows the loader to work with source `and' bytecode files; it does not allow for `sourceless' loading where only bytecode is provided. Bytecode files are an optimization to speed up loading by removing the parsing step of Python’s compiler, and so no bytecode-specific API is exposed. -- Method: path_stats (path) Optional abstract method which returns a *note dict: 1b8. containing metadata about the specified path. Supported dictionary keys are: - ‘'mtime'’ (mandatory): an integer or floating-point number representing the modification time of the source code; - ‘'size'’ (optional): the size in bytes of the source code. Any other keys in the dictionary are ignored, to allow for future extensions. If the path cannot be handled, *note OSError: 1d3. is raised. New in version 3.3. Changed in version 3.4: Raise *note OSError: 1d3. instead of *note NotImplementedError: 60e. -- Method: path_mtime (path) Optional abstract method which returns the modification time for the specified path. Deprecated since version 3.3: This method is deprecated in favour of *note path_stats(): aec. You don’t have to implement it, but it is still available for compatibility purposes. Raise *note OSError: 1d3. if the path cannot be handled. Changed in version 3.4: Raise *note OSError: 1d3. instead of *note NotImplementedError: 60e. -- Method: set_data (path, data) Optional abstract method which writes the specified bytes to a file path. Any intermediate directories which do not exist are to be created automatically. When writing to the path fails because the path is read-only (*note errno.EACCES: 1f28./*note PermissionError: 5ff.), do not propagate the exception. Changed in version 3.4: No longer raises *note NotImplementedError: 60e. when called. -- Method: get_code (fullname) Concrete implementation of *note InspectLoader.get_code(): 861. -- Method: exec_module (module) Concrete implementation of *note Loader.exec_module(): 5e4. New in version 3.4. -- Method: load_module (fullname) Concrete implementation of *note Loader.load_module(): 5e3. Deprecated since version 3.4: Use *note exec_module(): 940. instead. -- Method: get_source (fullname) Concrete implementation of *note InspectLoader.get_source(): 865. -- Method: is_package (fullname) Concrete implementation of *note InspectLoader.is_package(): 3494. A module is determined to be a package if its file path (as provided by *note ExecutionLoader.get_filename(): 3496.) is a file named ‘__init__’ when the file extension is removed `and' the module name itself does not end in ‘__init__’. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/importlib/abc.py (2) https://www.python.org/dev/peps/pep-0302 (3) https://www.python.org/dev/peps/pep-0302 (4) https://www.python.org/dev/peps/pep-0302 (5) https://www.python.org/dev/peps/pep-0302 (6) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: importlib resources – Resources, Next: importlib machinery – Importers and path hooks, Prev: importlib abc – Abstract base classes related to import, Up: importlib — The implementation of import 5.31.5.4 ‘importlib.resources’ – Resources .......................................... `Source code:' Lib/importlib/resources.py(1) __________________________________________________________________ New in version 3.7. This module leverages Python’s import system to provide access to `resources' within `packages'. If you can import a package, you can access resources within that package. Resources can be opened or read, in either binary or text mode. Resources are roughly akin to files inside directories, though it’s important to keep in mind that this is just a metaphor. Resources and packages `do not' have to exist as physical files and directories on the file system. Note: This module provides functionality similar to pkg_resources(2) Basic Resource Access(3) without the performance overhead of that package. This makes reading resources included in packages easier, with more stable and consistent semantics. The standalone backport of this module provides more information on using importlib.resources(4) and migrating from pkg_resources to importlib.resources(5). Loaders that wish to support resource reading should implement a ‘get_resource_reader(fullname)’ method as specified by *note importlib.abc.ResourceReader: 342. The following types are defined. -- Data: importlib.resources.Package The ‘Package’ type is defined as ‘Union[str, ModuleType]’. This means that where the function describes accepting a ‘Package’, you can pass in either a string or a module. Module objects must have a resolvable ‘__spec__.submodule_search_locations’ that is not ‘None’. -- Data: importlib.resources.Resource This type describes the resource names passed into the various functions in this package. This is defined as ‘Union[str, os.PathLike]’. The following functions are available. -- Function: importlib.resources.open_binary (package, resource) Open for binary reading the `resource' within `package'. `package' is either a name or a module object which conforms to the ‘Package’ requirements. `resource' is the name of the resource to open within `package'; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). This function returns a ‘typing.BinaryIO’ instance, a binary I/O stream open for reading. -- Function: importlib.resources.open_text (package, resource, encoding='utf-8', errors='strict') Open for text reading the `resource' within `package'. By default, the resource is opened for reading as UTF-8. `package' is either a name or a module object which conforms to the ‘Package’ requirements. `resource' is the name of the resource to open within `package'; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). `encoding' and `errors' have the same meaning as with built-in *note open(): 4f0. This function returns a ‘typing.TextIO’ instance, a text I/O stream open for reading. -- Function: importlib.resources.read_binary (package, resource) Read and return the contents of the `resource' within `package' as ‘bytes’. `package' is either a name or a module object which conforms to the ‘Package’ requirements. `resource' is the name of the resource to open within `package'; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). This function returns the contents of the resource as *note bytes: 331. -- Function: importlib.resources.read_text (package, resource, encoding='utf-8', errors='strict') Read and return the contents of `resource' within `package' as a ‘str’. By default, the contents are read as strict UTF-8. `package' is either a name or a module object which conforms to the ‘Package’ requirements. `resource' is the name of the resource to open within `package'; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). `encoding' and `errors' have the same meaning as with built-in *note open(): 4f0. This function returns the contents of the resource as *note str: 330. -- Function: importlib.resources.path (package, resource) Return the path to the `resource' as an actual file system path. This function returns a context manager for use in a *note with: 6e9. statement. The context manager provides a *note pathlib.Path: 201. object. Exiting the context manager cleans up any temporary file created when the resource needs to be extracted from e.g. a zip file. `package' is either a name or a module object which conforms to the ‘Package’ requirements. `resource' is the name of the resource to open within `package'; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). -- Function: importlib.resources.is_resource (package, name) Return ‘True’ if there is a resource named `name' in the package, otherwise ‘False’. Remember that directories are `not' resources! `package' is either a name or a module object which conforms to the ‘Package’ requirements. -- Function: importlib.resources.contents (package) Return an iterable over the named items within the package. The iterable returns *note str: 330. resources (e.g. files) and non-resources (e.g. directories). The iterable does not recurse into subdirectories. `package' is either a name or a module object which conforms to the ‘Package’ requirements. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/importlib/resources.py (2) https://setuptools.readthedocs.io/en/latest/pkg_resources.html (3) http://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access (4) http://importlib-resources.readthedocs.io/en/latest/using.html (5) http://importlib-resources.readthedocs.io/en/latest/migration.html  File: python.info, Node: importlib machinery – Importers and path hooks, Next: importlib util – Utility code for importers, Prev: importlib resources – Resources, Up: importlib — The implementation of import 5.31.5.5 ‘importlib.machinery’ – Importers and path hooks ......................................................... `Source code:' Lib/importlib/machinery.py(1) __________________________________________________________________ This module contains the various objects that help *note import: c1d. find and load modules. -- Attribute: importlib.machinery.SOURCE_SUFFIXES A list of strings representing the recognized file suffixes for source modules. New in version 3.3. -- Attribute: importlib.machinery.DEBUG_BYTECODE_SUFFIXES A list of strings representing the file suffixes for non-optimized bytecode modules. New in version 3.3. Deprecated since version 3.5: Use *note BYTECODE_SUFFIXES: 34ac. instead. -- Attribute: importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES A list of strings representing the file suffixes for optimized bytecode modules. New in version 3.3. Deprecated since version 3.5: Use *note BYTECODE_SUFFIXES: 34ac. instead. -- Attribute: importlib.machinery.BYTECODE_SUFFIXES A list of strings representing the recognized file suffixes for bytecode modules (including the leading dot). New in version 3.3. Changed in version 3.5: The value is no longer dependent on ‘__debug__’. -- Attribute: importlib.machinery.EXTENSION_SUFFIXES A list of strings representing the recognized file suffixes for extension modules. New in version 3.3. -- Function: importlib.machinery.all_suffixes () Returns a combined list of strings representing all file suffixes for modules recognized by the standard import machinery. This is a helper for code which simply needs to know if a filesystem path potentially refers to a module without needing any details on the kind of module (for example, *note inspect.getmodulename(): 5f2.). New in version 3.3. -- Class: importlib.machinery.BuiltinImporter An *note importer: 1161. for built-in modules. All known built-in modules are listed in *note sys.builtin_module_names: 334a. This class implements the *note importlib.abc.MetaPathFinder: 9b3. and *note importlib.abc.InspectLoader: 860. ABCs. Only class methods are defined by this class to alleviate the need for instantiation. Changed in version 3.5: As part of PEP 489(2), the builtin importer now implements ‘Loader.create_module()’ and ‘Loader.exec_module()’ -- Class: importlib.machinery.FrozenImporter An *note importer: 1161. for frozen modules. This class implements the *note importlib.abc.MetaPathFinder: 9b3. and *note importlib.abc.InspectLoader: 860. ABCs. Only class methods are defined by this class to alleviate the need for instantiation. Changed in version 3.4: Gained ‘create_module()’ and ‘exec_module()’ methods. -- Class: importlib.machinery.WindowsRegistryFinder *note Finder: 115f. for modules declared in the Windows registry. This class implements the *note importlib.abc.MetaPathFinder: 9b3. ABC. Only class methods are defined by this class to alleviate the need for instantiation. New in version 3.3. Deprecated since version 3.6: Use *note site: eb. configuration instead. Future versions of Python may not enable this finder by default. -- Class: importlib.machinery.PathFinder A *note Finder: 115f. for *note sys.path: 488. and package ‘__path__’ attributes. This class implements the *note importlib.abc.MetaPathFinder: 9b3. ABC. Only class methods are defined by this class to alleviate the need for instantiation. -- Method: classmethod find_spec (fullname, path=None, target=None) Class method that attempts to find a *note spec: 3360. for the module specified by `fullname' on *note sys.path: 488. or, if defined, on `path'. For each path entry that is searched, *note sys.path_importer_cache: 49d. is checked. If a non-false object is found then it is used as the *note path entry finder: 9b2. to look for the module being searched for. If no entry is found in *note sys.path_importer_cache: 49d, then *note sys.path_hooks: 95c. is searched for a finder for the path entry and, if found, is stored in *note sys.path_importer_cache: 49d. along with being queried about the module. If no finder is ever found then ‘None’ is both stored in the cache and returned. New in version 3.4. Changed in version 3.5: If the current working directory – represented by an empty string – is no longer valid then ‘None’ is returned but no value is cached in *note sys.path_importer_cache: 49d. -- Method: classmethod find_module (fullname, path=None) A legacy wrapper around *note find_spec(): 93a. Deprecated since version 3.4: Use *note find_spec(): 93a. instead. -- Method: classmethod invalidate_caches () Calls *note importlib.abc.PathEntryFinder.invalidate_caches(): 348f. on all finders stored in *note sys.path_importer_cache: 49d. that define the method. Otherwise entries in *note sys.path_importer_cache: 49d. set to ‘None’ are deleted. Changed in version 3.7: Entries of ‘None’ in *note sys.path_importer_cache: 49d. are deleted. Changed in version 3.4: Calls objects in *note sys.path_hooks: 95c. with the current working directory for ‘''’ (i.e. the empty string). -- Class: importlib.machinery.FileFinder (path, *loader_details) A concrete implementation of *note importlib.abc.PathEntryFinder: 9b4. which caches results from the file system. The `path' argument is the directory for which the finder is in charge of searching. The `loader_details' argument is a variable number of 2-item tuples each containing a loader and a sequence of file suffixes the loader recognizes. The loaders are expected to be callables which accept two arguments of the module’s name and the path to the file found. The finder will cache the directory contents as necessary, making stat calls for each module search to verify the cache is not outdated. Because cache staleness relies upon the granularity of the operating system’s state information of the file system, there is a potential race condition of searching for a module, creating a new file, and then searching for the module the new file represents. If the operations happen fast enough to fit within the granularity of stat calls, then the module search will fail. To prevent this from happening, when you create a module dynamically, make sure to call *note importlib.invalidate_caches(): 49c. New in version 3.3. -- Attribute: path The path the finder will search in. -- Method: find_spec (fullname, target=None) Attempt to find the spec to handle `fullname' within *note path: 34af. New in version 3.4. -- Method: find_loader (fullname) Attempt to find the loader to handle `fullname' within *note path: 34af. -- Method: invalidate_caches () Clear out the internal cache. -- Method: classmethod path_hook (*loader_details) A class method which returns a closure for use on *note sys.path_hooks: 95c. An instance of *note FileFinder: 9b6. is returned by the closure using the path argument given to the closure directly and `loader_details' indirectly. If the argument to the closure is not an existing directory, *note ImportError: 334. is raised. -- Class: importlib.machinery.SourceFileLoader (fullname, path) A concrete implementation of *note importlib.abc.SourceLoader: 349b. by subclassing *note importlib.abc.FileLoader: 9b7. and providing some concrete implementations of other methods. New in version 3.3. -- Attribute: name The name of the module that this loader will handle. -- Attribute: path The path to the source file. -- Method: is_package (fullname) Return ‘True’ if *note path: 34b4. appears to be for a package. -- Method: path_stats (path) Concrete implementation of *note importlib.abc.SourceLoader.path_stats(): aec. -- Method: set_data (path, data) Concrete implementation of *note importlib.abc.SourceLoader.set_data(): 349c. -- Method: load_module (name=None) Concrete implementation of *note importlib.abc.Loader.load_module(): 5e3. where specifying the name of the module to load is optional. Deprecated since version 3.6: Use *note importlib.abc.Loader.exec_module(): 5e4. instead. -- Class: importlib.machinery.SourcelessFileLoader (fullname, path) A concrete implementation of *note importlib.abc.FileLoader: 9b7. which can import bytecode files (i.e. no source code files exist). Please note that direct use of bytecode files (and thus not source code files) inhibits your modules from being usable by all Python implementations or new versions of Python which change the bytecode format. New in version 3.3. -- Attribute: name The name of the module the loader will handle. -- Attribute: path The path to the bytecode file. -- Method: is_package (fullname) Determines if the module is a package based on *note path: 34b9. -- Method: get_code (fullname) Returns the code object for *note name: 34b8. created from *note path: 34b9. -- Method: get_source (fullname) Returns ‘None’ as bytecode files have no source when this loader is used. -- Method: load_module (name=None) Concrete implementation of *note importlib.abc.Loader.load_module(): 5e3. where specifying the name of the module to load is optional. Deprecated since version 3.6: Use *note importlib.abc.Loader.exec_module(): 5e4. instead. -- Class: importlib.machinery.ExtensionFileLoader (fullname, path) A concrete implementation of *note importlib.abc.ExecutionLoader: 3495. for extension modules. The `fullname' argument specifies the name of the module the loader is to support. The `path' argument is the path to the extension module’s file. New in version 3.3. -- Attribute: name Name of the module the loader supports. -- Attribute: path Path to the extension module. -- Method: create_module (spec) Creates the module object from the given specification in accordance with PEP 489(3). New in version 3.5. -- Method: exec_module (module) Initializes the given module object in accordance with PEP 489(4). New in version 3.5. -- Method: is_package (fullname) Returns ‘True’ if the file path points to a package’s ‘__init__’ module based on *note EXTENSION_SUFFIXES: 34ae. -- Method: get_code (fullname) Returns ‘None’ as extension modules lack a code object. -- Method: get_source (fullname) Returns ‘None’ as extension modules do not have source code. -- Method: get_filename (fullname) Returns *note path: 34be. New in version 3.4. -- Class: importlib.machinery.ModuleSpec (name, loader, *, origin=None, loader_state=None, is_package=None) A specification for a module’s import-system-related state. This is typically exposed as the module’s ‘__spec__’ attribute. In the descriptions below, the names in parentheses give the corresponding attribute available directly on the module object. E.g. ‘module.__spec__.origin == module.__file__’. Note however that while the `values' are usually equivalent, they can differ since there is no synchronization between the two objects. Thus it is possible to update the module’s ‘__path__’ at runtime, and this will not be automatically reflected in ‘__spec__.submodule_search_locations’. New in version 3.4. -- Attribute: name (‘__name__’) A string for the fully-qualified name of the module. -- Attribute: loader (‘__loader__’) The *note Loader: 1160. that should be used when loading the module. *note Finders: 115f. should always set this. -- Attribute: origin (‘__file__’) Name of the place from which the module is loaded, e.g. “builtin” for built-in modules and the filename for modules loaded from source. Normally “origin” should be set, but it may be ‘None’ (the default) which indicates it is unspecified (e.g. for namespace packages). -- Attribute: submodule_search_locations (‘__path__’) List of strings for where to find submodules, if a package (‘None’ otherwise). -- Attribute: loader_state Container of extra module-specific data for use during loading (or ‘None’). -- Attribute: cached (‘__cached__’) String for where the compiled module should be stored (or ‘None’). -- Attribute: parent (‘__package__’) (Read-only) The fully-qualified name of the package under which the module should be loaded as a submodule (or the empty string for top-level modules). For packages, it is the same as *note __name__: d12. -- Attribute: has_location Boolean indicating whether or not the module’s “origin” attribute refers to a loadable location. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/importlib/machinery.py (2) https://www.python.org/dev/peps/pep-0489 (3) https://www.python.org/dev/peps/pep-0489 (4) https://www.python.org/dev/peps/pep-0489  File: python.info, Node: importlib util – Utility code for importers, Next: Examples<29>, Prev: importlib machinery – Importers and path hooks, Up: importlib — The implementation of import 5.31.5.6 ‘importlib.util’ – Utility code for importers ...................................................... `Source code:' Lib/importlib/util.py(1) __________________________________________________________________ This module contains the various objects that help in the construction of an *note importer: 1161. -- Attribute: importlib.util.MAGIC_NUMBER The bytes which represent the bytecode version number. If you need help with loading/writing bytecode then consider *note importlib.abc.SourceLoader: 349b. New in version 3.4. -- Function: importlib.util.cache_from_source (path, debug_override=None, *, optimization=None) Return the PEP 3147(2)/ PEP 488(3) path to the byte-compiled file associated with the source `path'. For example, if `path' is ‘/foo/bar/baz.py’ the return value would be ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ for Python 3.2. The ‘cpython-32’ string comes from the current magic tag (see ‘get_tag()’; if ‘sys.implementation.cache_tag’ is not defined then *note NotImplementedError: 60e. will be raised). The `optimization' parameter is used to specify the optimization level of the bytecode file. An empty string represents no optimization, so ‘/foo/bar/baz.py’ with an `optimization' of ‘''’ will result in a bytecode path of ‘/foo/bar/__pycache__/baz.cpython-32.pyc’. ‘None’ causes the interpreter’s optimization level to be used. Any other value’s string representation is used, so ‘/foo/bar/baz.py’ with an `optimization' of ‘2’ will lead to the bytecode path of ‘/foo/bar/__pycache__/baz.cpython-32.opt-2.pyc’. The string representation of `optimization' can only be alphanumeric, else *note ValueError: 1fb. is raised. The `debug_override' parameter is deprecated and can be used to override the system’s value for ‘__debug__’. A ‘True’ value is the equivalent of setting `optimization' to the empty string. A ‘False’ value is the same as setting `optimization' to ‘1’. If both `debug_override' an `optimization' are not ‘None’ then *note TypeError: 192. is raised. New in version 3.4. Changed in version 3.5: The `optimization' parameter was added and the `debug_override' parameter was deprecated. Changed in version 3.6: Accepts a *note path-like object: 36a. -- Function: importlib.util.source_from_cache (path) Given the `path' to a PEP 3147(4) file name, return the associated source code file path. For example, if `path' is ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ the returned path would be ‘/foo/bar/baz.py’. `path' need not exist, however if it does not conform to PEP 3147(5) or PEP 488(6) format, a *note ValueError: 1fb. is raised. If ‘sys.implementation.cache_tag’ is not defined, *note NotImplementedError: 60e. is raised. New in version 3.4. Changed in version 3.6: Accepts a *note path-like object: 36a. -- Function: importlib.util.decode_source (source_bytes) Decode the given bytes representing source code and return it as a string with universal newlines (as required by *note importlib.abc.InspectLoader.get_source(): 865.). New in version 3.4. -- Function: importlib.util.resolve_name (name, package) Resolve a relative module name to an absolute one. If `name' has no leading dots, then `name' is simply returned. This allows for usage such as ‘importlib.util.resolve_name('sys', __spec__.parent)’ without doing a check to see if the `package' argument is needed. *note ValueError: 1fb. is raised if `name' is a relative module name but package is a false value (e.g. ‘None’ or the empty string). *note ValueError: 1fb. is also raised a relative name would escape its containing package (e.g. requesting ‘..bacon’ from within the ‘spam’ package). New in version 3.3. -- Function: importlib.util.find_spec (name, package=None) Find the *note spec: 3360. for a module, optionally relative to the specified `package' name. If the module is in *note sys.modules: 1152, then ‘sys.modules[name].__spec__’ is returned (unless the spec would be ‘None’ or is not set, in which case *note ValueError: 1fb. is raised). Otherwise a search using *note sys.meta_path: 5e6. is done. ‘None’ is returned if no spec is found. If `name' is for a submodule (contains a dot), the parent module is automatically imported. `name' and `package' work the same as for ‘import_module()’. New in version 3.4. Changed in version 3.7: Raises *note ModuleNotFoundError: 39a. instead of *note AttributeError: 39b. if `package' is in fact not a package (i.e. lacks a *note __path__: f23. attribute). -- Function: importlib.util.module_from_spec (spec) Create a new module based on `spec' and *note spec.loader.create_module: 554. If *note spec.loader.create_module: 554. does not return ‘None’, then any pre-existing attributes will not be reset. Also, no *note AttributeError: 39b. will be raised if triggered while accessing `spec' or setting an attribute on the module. This function is preferred over using *note types.ModuleType: 6f1. to create a new module as `spec' is used to set as many import-controlled attributes on the module as possible. New in version 3.5. -- Function: @importlib.util.module_for_loader A *note decorator: 283. for *note importlib.abc.Loader.load_module(): 5e3. to handle selecting the proper module object to load with. The decorated method is expected to have a call signature taking two positional arguments (e.g. ‘load_module(self, module)’) for which the second argument will be the module `object' to be used by the loader. Note that the decorator will not work on static methods because of the assumption of two arguments. The decorated method will take in the `name' of the module to be loaded as expected for a *note loader: 1160. If the module is not found in *note sys.modules: 1152. then a new one is constructed. Regardless of where the module came from, *note __loader__: 956. set to `self' and *note __package__: 955. is set based on what *note importlib.abc.InspectLoader.is_package(): 3494. returns (if available). These attributes are set unconditionally to support reloading. If an exception is raised by the decorated method and a module was added to *note sys.modules: 1152, then the module will be removed to prevent a partially initialized module from being in left in *note sys.modules: 1152. If the module was already in *note sys.modules: 1152. then it is left alone. Changed in version 3.3: *note __loader__: 956. and *note __package__: 955. are automatically set (when possible). Changed in version 3.4: Set *note __name__: d12, *note __loader__: 956. *note __package__: 955. unconditionally to support reloading. Deprecated since version 3.4: The import machinery now directly performs all the functionality provided by this function. -- Function: @importlib.util.set_loader A *note decorator: 283. for *note importlib.abc.Loader.load_module(): 5e3. to set the *note __loader__: 956. attribute on the returned module. If the attribute is already set the decorator does nothing. It is assumed that the first positional argument to the wrapped method (i.e. ‘self’) is what *note __loader__: 956. should be set to. Changed in version 3.4: Set ‘__loader__’ if set to ‘None’, as if the attribute does not exist. Deprecated since version 3.4: The import machinery takes care of this automatically. -- Function: @importlib.util.set_package A *note decorator: 283. for *note importlib.abc.Loader.load_module(): 5e3. to set the *note __package__: 955. attribute on the returned module. If *note __package__: 955. is set and has a value other than ‘None’ it will not be changed. Deprecated since version 3.4: The import machinery takes care of this automatically. -- Function: importlib.util.spec_from_loader (name, loader, *, origin=None, is_package=None) A factory function for creating a ‘ModuleSpec’ instance based on a loader. The parameters have the same meaning as they do for ModuleSpec. The function uses available *note loader: 1160. APIs, such as ‘InspectLoader.is_package()’, to fill in any missing information on the spec. New in version 3.4. -- Function: importlib.util.spec_from_file_location (name, location, *, loader=None, submodule_search_locations=None) A factory function for creating a ‘ModuleSpec’ instance based on the path to a file. Missing information will be filled in on the spec by making use of loader APIs and by the implication that the module will be file-based. New in version 3.4. Changed in version 3.6: Accepts a *note path-like object: 36a. -- Function: importlib.util.source_hash (source_bytes) Return the hash of `source_bytes' as bytes. A hash-based ‘.pyc’ file embeds the *note source_hash(): 34cb. of the corresponding source file’s contents in its header. New in version 3.7. -- Class: importlib.util.LazyLoader (loader) A class which postpones the execution of the loader of a module until the module has an attribute accessed. This class `only' works with loaders that define *note exec_module(): 5e4. as control over what module type is used for the module is required. For those same reasons, the loader’s *note create_module(): 554. method must return ‘None’ or a type for which its ‘__class__’ attribute can be mutated along with not using *note slots: 34cc. Finally, modules which substitute the object placed into *note sys.modules: 1152. will not work as there is no way to properly replace the module references throughout the interpreter safely; *note ValueError: 1fb. is raised if such a substitution is detected. Note: For projects where startup time is critical, this class allows for potentially minimizing the cost of loading a module if it is never used. For projects where startup time is not essential then use of this class is `heavily' discouraged due to error messages created during loading being postponed and thus occurring out of context. New in version 3.5. Changed in version 3.6: Began calling *note create_module(): 554, removing the compatibility warning for *note importlib.machinery.BuiltinImporter: 555. and *note importlib.machinery.ExtensionFileLoader: 556. -- Method: classmethod factory (loader) A static method which returns a callable that creates a lazy loader. This is meant to be used in situations where the loader is passed by class instead of by instance. suffixes = importlib.machinery.SOURCE_SUFFIXES loader = importlib.machinery.SourceFileLoader lazy_loader = importlib.util.LazyLoader.factory(loader) finder = importlib.machinery.FileFinder(path, (lazy_loader, suffixes)) ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/importlib/util.py (2) https://www.python.org/dev/peps/pep-3147 (3) https://www.python.org/dev/peps/pep-0488 (4) https://www.python.org/dev/peps/pep-3147 (5) https://www.python.org/dev/peps/pep-3147 (6) https://www.python.org/dev/peps/pep-0488  File: python.info, Node: Examples<29>, Prev: importlib util – Utility code for importers, Up: importlib — The implementation of import 5.31.5.7 Examples ................. * Menu: * Importing programmatically:: * Checking if a module can be imported:: * Importing a source file directly:: * Setting up an importer:: * Approximating importlib.import_module(): Approximating importlib import_module.  File: python.info, Node: Importing programmatically, Next: Checking if a module can be imported, Up: Examples<29> 5.31.5.8 Importing programmatically ................................... To programmatically import a module, use *note importlib.import_module(): b13. import importlib itertools = importlib.import_module('itertools')  File: python.info, Node: Checking if a module can be imported, Next: Importing a source file directly, Prev: Importing programmatically, Up: Examples<29> 5.31.5.9 Checking if a module can be imported ............................................. If you need to find out if a module can be imported without actually doing the import, then you should use *note importlib.util.find_spec(): 938. import importlib.util import sys # For illustrative purposes. name = 'itertools' if name in sys.modules: print(f"{name!r} already in sys.modules") elif (spec := importlib.util.find_spec(name)) is not None: # If you chose to perform the actual import ... module = importlib.util.module_from_spec(spec) sys.modules[name] = module spec.loader.exec_module(module) print(f"{name!r} has been imported") else: print(f"can't find the {name!r} module")  File: python.info, Node: Importing a source file directly, Next: Setting up an importer, Prev: Checking if a module can be imported, Up: Examples<29> 5.31.5.10 Importing a source file directly .......................................... To import a Python source file directly, use the following recipe (Python 3.5 and newer only): import importlib.util import sys # For illustrative purposes. import tokenize file_path = tokenize.__file__ module_name = tokenize.__name__ spec = importlib.util.spec_from_file_location(module_name, file_path) module = importlib.util.module_from_spec(spec) sys.modules[module_name] = module spec.loader.exec_module(module)  File: python.info, Node: Setting up an importer, Next: Approximating importlib import_module, Prev: Importing a source file directly, Up: Examples<29> 5.31.5.11 Setting up an importer ................................ For deep customizations of import, you typically want to implement an *note importer: 1161. This means managing both the *note finder: 115f. and *note loader: 1160. side of things. For finders there are two flavours to choose from depending on your needs: a *note meta path finder: 9b1. or a *note path entry finder: 9b2. The former is what you would put on *note sys.meta_path: 5e6. while the latter is what you create using a *note path entry hook: 1177. on *note sys.path_hooks: 95c. which works with *note sys.path: 488. entries to potentially create a finder. This example will show you how to register your own importers so that import will use them (for creating an importer for yourself, read the documentation for the appropriate classes defined within this package): import importlib.machinery import sys # For illustrative purposes only. SpamMetaPathFinder = importlib.machinery.PathFinder SpamPathEntryFinder = importlib.machinery.FileFinder loader_details = (importlib.machinery.SourceFileLoader, importlib.machinery.SOURCE_SUFFIXES) # Setting up a meta path finder. # Make sure to put the finder in the proper location in the list in terms of # priority. sys.meta_path.append(SpamMetaPathFinder) # Setting up a path entry finder. # Make sure to put the path hook in the proper location in the list in terms # of priority. sys.path_hooks.append(SpamPathEntryFinder.path_hook(loader_details))  File: python.info, Node: Approximating importlib import_module, Prev: Setting up an importer, Up: Examples<29> 5.31.5.12 Approximating ‘importlib.import_module()’ ................................................... Import itself is implemented in Python code, making it possible to expose most of the import machinery through importlib. The following helps illustrate the various APIs that importlib exposes by providing an approximate implementation of *note importlib.import_module(): b13. (Python 3.4 and newer for the importlib usage, Python 3.6 and newer for other parts of the code). import importlib.util import sys def import_module(name, package=None): """An approximate implementation of import.""" absolute_name = importlib.util.resolve_name(name, package) try: return sys.modules[absolute_name] except KeyError: pass path = None if '.' in absolute_name: parent_name, _, child_name = absolute_name.rpartition('.') parent_module = import_module(parent_name) path = parent_module.__spec__.submodule_search_locations for finder in sys.meta_path: spec = finder.find_spec(absolute_name, path) if spec is not None: break else: msg = f'No module named {absolute_name!r}' raise ModuleNotFoundError(msg, name=absolute_name) module = importlib.util.module_from_spec(spec) sys.modules[absolute_name] = module spec.loader.exec_module(module) if path is not None: setattr(parent_module, child_name, module) return module  File: python.info, Node: Using importlib metadata, Prev: importlib — The implementation of import, Up: Importing Modules 5.31.6 Using ‘importlib.metadata’ --------------------------------- Note: This functionality is provisional and may deviate from the usual version semantics of the standard library. ‘importlib.metadata’ is a library that provides for access to installed package metadata. Built in part on Python’s import system, this library intends to replace similar functionality in the entry point API(1) and metadata API(2) of ‘pkg_resources’. Along with *note importlib.resources: 9e. in Python 3.7 and newer (backported as importlib_resources(3) for older versions of Python), this can eliminate the need to use the older and less efficient ‘pkg_resources’ package. By “installed package” we generally mean a third-party package installed into Python’s ‘site-packages’ directory via tools such as pip(4). Specifically, it means a package with either a discoverable ‘dist-info’ or ‘egg-info’ directory, and metadata defined by PEP 566(5) or its older specifications. By default, package metadata can live on the file system or in zip archives on *note sys.path: 488. Through an extension mechanism, the metadata can live almost anywhere. * Menu: * Overview: Overview<2>. * Functional API: Functional API<2>. * Distributions:: * Extending the search algorithm:: ---------- Footnotes ---------- (1) https://setuptools.readthedocs.io/en/latest/pkg_resources.html#entry-points (2) https://setuptools.readthedocs.io/en/latest/pkg_resources.html#metadata-api (3) https://importlib-resources.readthedocs.io/en/latest/index.html (4) https://pypi.org/project/pip/ (5) https://www.python.org/dev/peps/pep-0566  File: python.info, Node: Overview<2>, Next: Functional API<2>, Up: Using importlib metadata 5.31.6.1 Overview ................. Let’s say you wanted to get the version string for a package you’ve installed using ‘pip’. We start by creating a virtual environment and installing something into it: $ python3 -m venv example $ source example/bin/activate (example) $ pip install wheel You can get the version string for ‘wheel’ by running the following: (example) $ python >>> from importlib.metadata import version >>> version('wheel') '0.32.3' You can also get the set of entry points keyed by group, such as ‘console_scripts’, ‘distutils.commands’ and others. Each group contains a sequence of *note EntryPoint: 34d9. objects. You can get the *note metadata for a distribution: 34da.: >>> list(metadata('wheel')) ['Metadata-Version', 'Name', 'Version', 'Summary', 'Home-page', 'Author', 'Author-email', 'Maintainer', 'Maintainer-email', 'License', 'Project-URL', 'Project-URL', 'Project-URL', 'Keywords', 'Platform', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Requires-Python', 'Provides-Extra', 'Requires-Dist', 'Requires-Dist'] You can also get a *note distribution’s version number: 34db, list its *note constituent files: 34dc, and get a list of the distribution’s *note Distribution requirements: 34dd.  File: python.info, Node: Functional API<2>, Next: Distributions, Prev: Overview<2>, Up: Using importlib metadata 5.31.6.2 Functional API ....................... This package provides the following functionality via its public API. * Menu: * Entry points:: * Distribution metadata:: * Distribution versions:: * Distribution files:: * Distribution requirements::  File: python.info, Node: Entry points, Next: Distribution metadata, Up: Functional API<2> 5.31.6.3 Entry points ..................... The ‘entry_points()’ function returns a dictionary of all entry points, keyed by group. Entry points are represented by ‘EntryPoint’ instances; each ‘EntryPoint’ has a ‘.name’, ‘.group’, and ‘.value’ attributes and a ‘.load()’ method to resolve the value. >>> eps = entry_points() >>> list(eps) ['console_scripts', 'distutils.commands', 'distutils.setup_keywords', 'egg_info.writers', 'setuptools.installation'] >>> scripts = eps['console_scripts'] >>> wheel = [ep for ep in scripts if ep.name == 'wheel'][0] >>> wheel EntryPoint(name='wheel', value='wheel.cli:main', group='console_scripts') >>> main = wheel.load() >>> main <function main at 0x103528488> The ‘group’ and ‘name’ are arbitrary values defined by the package author and usually a client will wish to resolve all entry points for a particular group. Read the setuptools docs(1) for more information on entrypoints, their definition, and usage. ---------- Footnotes ---------- (1) https://setuptools.readthedocs.io/en/latest/setuptools.html#dynamic-discovery-of-services-and-plugins  File: python.info, Node: Distribution metadata, Next: Distribution versions, Prev: Entry points, Up: Functional API<2> 5.31.6.4 Distribution metadata .............................. Every distribution includes some metadata, which you can extract using the ‘metadata()’ function: >>> wheel_metadata = metadata('wheel') The keys of the returned data structure (1) name the metadata keywords, and their values are returned unparsed from the distribution metadata: >>> wheel_metadata['Requires-Python'] '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*' ---------- Footnotes ---------- (1) (1) Technically, the returned distribution metadata object is an *note email.message.EmailMessage: 542. instance, but this is an implementation detail, and not part of the stable API. You should only use dictionary-like methods and syntax to access the metadata contents.  File: python.info, Node: Distribution versions, Next: Distribution files, Prev: Distribution metadata, Up: Functional API<2> 5.31.6.5 Distribution versions .............................. The ‘version()’ function is the quickest way to get a distribution’s version number, as a string: >>> version('wheel') '0.32.3'  File: python.info, Node: Distribution files, Next: Distribution requirements, Prev: Distribution versions, Up: Functional API<2> 5.31.6.6 Distribution files ........................... You can also get the full set of files contained within a distribution. The ‘files()’ function takes a distribution package name and returns all of the files installed by this distribution. Each file object returned is a ‘PackagePath’, a *note pathlib.Path: 201. derived object with additional ‘dist’, ‘size’, and ‘hash’ properties as indicated by the metadata. For example: >>> util = [p for p in files('wheel') if 'util.py' in str(p)][0] >>> util PackagePath('wheel/util.py') >>> util.size 859 >>> util.dist <importlib.metadata._hooks.PathDistribution object at 0x101e0cef0> >>> util.hash <FileHash mode: sha256 value: bYkw5oMccfazVCoYQwKkkemoVyMAFoR34mmKBx8R1NI> Once you have the file, you can also read its contents: >>> print(util.read_text()) import base64 import sys ... def as_bytes(s): if isinstance(s, text_type): return s.encode('utf-8') return s In the case where the metadata file listing files (RECORD or SOURCES.txt) is missing, ‘files()’ will return ‘None’. The caller may wish to wrap calls to ‘files()’ in always_iterable(1) or otherwise guard against this condition if the target distribution is not known to have the metadata present. ---------- Footnotes ---------- (1) https://more-itertools.readthedocs.io/en/stable/api.html#more_itertools.always_iterable  File: python.info, Node: Distribution requirements, Prev: Distribution files, Up: Functional API<2> 5.31.6.7 Distribution requirements .................................. To get the full set of requirements for a distribution, use the ‘requires()’ function: >>> requires('wheel') ["pytest (>=3.0.0) ; extra == 'test'", "pytest-cov ; extra == 'test'"]  File: python.info, Node: Distributions, Next: Extending the search algorithm, Prev: Functional API<2>, Up: Using importlib metadata 5.31.6.8 Distributions ...................... While the above API is the most common and convenient usage, you can get all of that information from the ‘Distribution’ class. A ‘Distribution’ is an abstract object that represents the metadata for a Python package. You can get the ‘Distribution’ instance: >>> from importlib.metadata import distribution >>> dist = distribution('wheel') Thus, an alternative way to get the version number is through the ‘Distribution’ instance: >>> dist.version '0.32.3' There are all kinds of additional metadata available on the ‘Distribution’ instance: >>> dist.metadata['Requires-Python'] '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*' >>> dist.metadata['License'] 'MIT' The full set of available metadata is not described here. See PEP 566(1) for additional details. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0566  File: python.info, Node: Extending the search algorithm, Prev: Distributions, Up: Using importlib metadata 5.31.6.9 Extending the search algorithm ....................................... Because package metadata is not available through *note sys.path: 488. searches, or package loaders directly, the metadata for a package is found through import system *note finders: 115d. To find a distribution package’s metadata, ‘importlib.metadata’ queries the list of *note meta path finders: 9b1. on *note sys.meta_path: 5e6. The default ‘PathFinder’ for Python includes a hook that calls into ‘importlib.metadata.MetadataPathFinder’ for finding distributions loaded from typical file-system-based paths. The abstract class *note importlib.abc.MetaPathFinder: 9b3. defines the interface expected of finders by Python’s import system. ‘importlib.metadata’ extends this protocol by looking for an optional ‘find_distributions’ callable on the finders from *note sys.meta_path: 5e6. and presents this extended interface as the ‘DistributionFinder’ abstract base class, which defines this abstract method: @abc.abstractmethod def find_distributions(context=DistributionFinder.Context()): """Return an iterable of all Distribution instances capable of loading the metadata for packages for the indicated ``context``. """ The ‘DistributionFinder.Context’ object provides ‘.path’ and ‘.name’ properties indicating the path to search and names to match and may supply other relevant context. What this means in practice is that to support finding distribution package metadata in locations other than the file system, subclass ‘Distribution’ and implement the abstract methods. Then from a custom finder, return instances of this derived ‘Distribution’ in the ‘find_distributions()’ method.  File: python.info, Node: Python Language Services, Next: Miscellaneous Services, Prev: Importing Modules, Up: The Python Standard Library 5.32 Python Language Services ============================= Python provides a number of modules to assist in working with the Python language. These modules support tokenizing, parsing, syntax analysis, bytecode disassembly, and various other facilities. These modules include: * Menu: * parser — Access Python parse trees:: * ast — Abstract Syntax Trees:: * symtable — Access to the compiler’s symbol tables:: * symbol — Constants used with Python parse trees:: * token — Constants used with Python parse trees:: * keyword — Testing for Python keywords:: * tokenize — Tokenizer for Python source:: * tabnanny — Detection of ambiguous indentation:: * pyclbr — Python module browser support:: * py_compile — Compile Python source files:: * compileall — Byte-compile Python libraries:: * dis — Disassembler for Python bytecode:: * pickletools — Tools for pickle developers::  File: python.info, Node: parser — Access Python parse trees, Next: ast — Abstract Syntax Trees, Up: Python Language Services 5.32.1 ‘parser’ — Access Python parse trees ------------------------------------------- __________________________________________________________________ The *note parser: c7. module provides an interface to Python’s internal parser and byte-code compiler. The primary purpose for this interface is to allow Python code to edit the parse tree of a Python expression and create executable code from this. This is better than trying to parse and modify an arbitrary Python code fragment as a string because parsing is performed in a manner identical to the code forming the application. It is also faster. Note: From Python 2.5 onward, it’s much more convenient to cut in at the Abstract Syntax Tree (AST) generation and compilation stage, using the *note ast: 8. module. There are a few things to note about this module which are important to making use of the data structures created. This is not a tutorial on editing the parse trees for Python code, but some examples of using the *note parser: c7. module are presented. Most importantly, a good understanding of the Python grammar processed by the internal parser is required. For full information on the language syntax, refer to *note The Python Language Reference: e8f. The parser itself is created from a grammar specification defined in the file ‘Grammar/Grammar’ in the standard Python distribution. The parse trees stored in the ST objects created by this module are the actual output from the internal parser when created by the *note expr(): 34eb. or *note suite(): 34ec. functions, described below. The ST objects created by *note sequence2st(): 34ed. faithfully simulate those structures. Be aware that the values of the sequences which are considered “correct” will vary from one version of Python to another as the formal grammar for the language is revised. However, transporting code from one Python version to another as source text will always allow correct parse trees to be created in the target version, with the only restriction being that migrating to an older version of the interpreter will not support more recent language constructs. The parse trees are not typically compatible from one version to another, though source code has usually been forward-compatible within a major release series. Each element of the sequences returned by *note st2list(): 34ee. or *note st2tuple(): 34ef. has a simple form. Sequences representing non-terminal elements in the grammar always have a length greater than one. The first element is an integer which identifies a production in the grammar. These integers are given symbolic names in the C header file ‘Include/graminit.h’ and the Python module *note symbol: fb. Each additional element of the sequence represents a component of the production as recognized in the input string: these are always sequences which have the same form as the parent. An important aspect of this structure which should be noted is that keywords used to identify the parent node type, such as the keyword *note if: de7. in an ‘if_stmt’, are included in the node tree without any special treatment. For example, the ‘if’ keyword is represented by the tuple ‘(1, 'if')’, where ‘1’ is the numeric value associated with all ‘NAME’ tokens, including variable and function names defined by the user. In an alternate form returned when line number information is requested, the same token might be represented as ‘(1, 'if', 12)’, where the ‘12’ represents the line number at which the terminal symbol was found. Terminal elements are represented in much the same way, but without any child elements and the addition of the source text which was identified. The example of the *note if: de7. keyword above is representative. The various types of terminal symbols are defined in the C header file ‘Include/token.h’ and the Python module *note token: 110. The ST objects are not required to support the functionality of this module, but are provided for three purposes: to allow an application to amortize the cost of processing complex parse trees, to provide a parse tree representation which conserves memory space when compared to the Python list or tuple representation, and to ease the creation of additional modules in C which manipulate parse trees. A simple “wrapper” class may be created in Python to hide the use of ST objects. The *note parser: c7. module defines functions for a few distinct purposes. The most important purposes are to create ST objects and to convert ST objects to other representations such as parse trees and compiled code objects, but there are also functions which serve to query the type of parse tree represented by an ST object. See also ........ Module *note symbol: fb. Useful constants representing internal nodes of the parse tree. Module *note token: 110. Useful constants representing leaf nodes of the parse tree and functions for testing node values. * Menu: * Creating ST Objects:: * Converting ST Objects:: * Queries on ST Objects:: * Exceptions and Error Handling:: * ST Objects:: * Example; Emulation of compile(): Example Emulation of compile.  File: python.info, Node: Creating ST Objects, Next: Converting ST Objects, Up: parser — Access Python parse trees 5.32.1.1 Creating ST Objects ............................ ST objects may be created from source code or from a parse tree. When creating an ST object from source, different functions are used to create the ‘'eval'’ and ‘'exec'’ forms. -- Function: parser.expr (source) The *note expr(): 34eb. function parses the parameter `source' as if it were an input to ‘compile(source, 'file.py', 'eval')’. If the parse succeeds, an ST object is created to hold the internal parse tree representation, otherwise an appropriate exception is raised. -- Function: parser.suite (source) The *note suite(): 34ec. function parses the parameter `source' as if it were an input to ‘compile(source, 'file.py', 'exec')’. If the parse succeeds, an ST object is created to hold the internal parse tree representation, otherwise an appropriate exception is raised. -- Function: parser.sequence2st (sequence) This function accepts a parse tree represented as a sequence and builds an internal representation if possible. If it can validate that the tree conforms to the Python grammar and all nodes are valid node types in the host version of Python, an ST object is created from the internal representation and returned to the called. If there is a problem creating the internal representation, or if the tree cannot be validated, a *note ParserError: 34f2. exception is raised. An ST object created this way should not be assumed to compile correctly; normal exceptions raised by compilation may still be initiated when the ST object is passed to *note compilest(): 34f3. This may indicate problems not related to syntax (such as a *note MemoryError: 13af. exception), but may also be due to constructs such as the result of parsing ‘del f(0)’, which escapes the Python parser but is checked by the bytecode compiler. Sequences representing terminal tokens may be represented as either two-element lists of the form ‘(1, 'name')’ or as three-element lists of the form ‘(1, 'name', 56)’. If the third element is present, it is assumed to be a valid line number. The line number may be specified for any subset of the terminal symbols in the input tree. -- Function: parser.tuple2st (sequence) This is the same function as *note sequence2st(): 34ed. This entry point is maintained for backward compatibility.  File: python.info, Node: Converting ST Objects, Next: Queries on ST Objects, Prev: Creating ST Objects, Up: parser — Access Python parse trees 5.32.1.2 Converting ST Objects .............................. ST objects, regardless of the input used to create them, may be converted to parse trees represented as list- or tuple- trees, or may be compiled into executable code objects. Parse trees may be extracted with or without line numbering information. -- Function: parser.st2list (st, line_info=False, col_info=False) This function accepts an ST object from the caller in `st' and returns a Python list representing the equivalent parse tree. The resulting list representation can be used for inspection or the creation of a new parse tree in list form. This function does not fail so long as memory is available to build the list representation. If the parse tree will only be used for inspection, *note st2tuple(): 34ef. should be used instead to reduce memory consumption and fragmentation. When the list representation is required, this function is significantly faster than retrieving a tuple representation and converting that to nested lists. If `line_info' is true, line number information will be included for all terminal tokens as a third element of the list representing the token. Note that the line number provided specifies the line on which the token `ends'. This information is omitted if the flag is false or omitted. -- Function: parser.st2tuple (st, line_info=False, col_info=False) This function accepts an ST object from the caller in `st' and returns a Python tuple representing the equivalent parse tree. Other than returning a tuple instead of a list, this function is identical to *note st2list(): 34ee. If `line_info' is true, line number information will be included for all terminal tokens as a third element of the list representing the token. This information is omitted if the flag is false or omitted. -- Function: parser.compilest (st, filename='<syntax-tree>') The Python byte compiler can be invoked on an ST object to produce code objects which can be used as part of a call to the built-in *note exec(): c44. or *note eval(): b90. functions. This function provides the interface to the compiler, passing the internal parse tree from `st' to the parser, using the source file name specified by the `filename' parameter. The default value supplied for `filename' indicates that the source was an ST object. Compiling an ST object may result in exceptions related to compilation; an example would be a *note SyntaxError: 458. caused by the parse tree for ‘del f(0)’: this statement is considered legal within the formal grammar for Python but is not a legal language construct. The *note SyntaxError: 458. raised for this condition is actually generated by the Python byte-compiler normally, which is why it can be raised at this point by the *note parser: c7. module. Most causes of compilation failure can be diagnosed programmatically by inspection of the parse tree.  File: python.info, Node: Queries on ST Objects, Next: Exceptions and Error Handling, Prev: Converting ST Objects, Up: parser — Access Python parse trees 5.32.1.3 Queries on ST Objects .............................. Two functions are provided which allow an application to determine if an ST was created as an expression or a suite. Neither of these functions can be used to determine if an ST was created from source code via *note expr(): 34eb. or *note suite(): 34ec. or from a parse tree via *note sequence2st(): 34ed. -- Function: parser.isexpr (st) When `st' represents an ‘'eval'’ form, this function returns ‘True’, otherwise it returns ‘False’. This is useful, since code objects normally cannot be queried for this information using existing built-in functions. Note that the code objects created by *note compilest(): 34f3. cannot be queried like this either, and are identical to those created by the built-in *note compile(): 1b4. function. -- Function: parser.issuite (st) This function mirrors *note isexpr(): 34f9. in that it reports whether an ST object represents an ‘'exec'’ form, commonly known as a “suite.” It is not safe to assume that this function is equivalent to ‘not isexpr(st)’, as additional syntactic fragments may be supported in the future.  File: python.info, Node: Exceptions and Error Handling, Next: ST Objects, Prev: Queries on ST Objects, Up: parser — Access Python parse trees 5.32.1.4 Exceptions and Error Handling ...................................... The parser module defines a single exception, but may also pass other built-in exceptions from other portions of the Python runtime environment. See each function for information about the exceptions it can raise. -- Exception: parser.ParserError Exception raised when a failure occurs within the parser module. This is generally produced for validation failures rather than the built-in *note SyntaxError: 458. raised during normal parsing. The exception argument is either a string describing the reason of the failure or a tuple containing a sequence causing the failure from a parse tree passed to *note sequence2st(): 34ed. and an explanatory string. Calls to *note sequence2st(): 34ed. need to be able to handle either type of exception, while calls to other functions in the module will only need to be aware of the simple string values. Note that the functions *note compilest(): 34f3, *note expr(): 34eb, and *note suite(): 34ec. may raise exceptions which are normally raised by the parsing and compilation process. These include the built in exceptions *note MemoryError: 13af, *note OverflowError: 960, *note SyntaxError: 458, and *note SystemError: 5fb. In these cases, these exceptions carry all the meaning normally associated with them. Refer to the descriptions of each function for detailed information.  File: python.info, Node: ST Objects, Next: Example Emulation of compile, Prev: Exceptions and Error Handling, Up: parser — Access Python parse trees 5.32.1.5 ST Objects ................... Ordered and equality comparisons are supported between ST objects. Pickling of ST objects (using the *note pickle: ca. module) is also supported. -- Data: parser.STType The type of the objects returned by *note expr(): 34eb, *note suite(): 34ec. and *note sequence2st(): 34ed. ST objects have the following methods: -- Method: ST.compile (filename='<syntax-tree>') Same as ‘compilest(st, filename)’. -- Method: ST.isexpr () Same as ‘isexpr(st)’. -- Method: ST.issuite () Same as ‘issuite(st)’. -- Method: ST.tolist (line_info=False, col_info=False) Same as ‘st2list(st, line_info, col_info)’. -- Method: ST.totuple (line_info=False, col_info=False) Same as ‘st2tuple(st, line_info, col_info)’.  File: python.info, Node: Example Emulation of compile, Prev: ST Objects, Up: parser — Access Python parse trees 5.32.1.6 Example: Emulation of ‘compile()’ .......................................... While many useful operations may take place between parsing and bytecode generation, the simplest operation is to do nothing. For this purpose, using the *note parser: c7. module to produce an intermediate data structure is equivalent to the code >>> code = compile('a + 5', 'file.py', 'eval') >>> a = 5 >>> eval(code) 10 The equivalent operation using the *note parser: c7. module is somewhat longer, and allows the intermediate internal parse tree to be retained as an ST object: >>> import parser >>> st = parser.expr('a + 5') >>> code = st.compile('file.py') >>> a = 5 >>> eval(code) 10 An application which needs both ST and code objects can package this code into readily available functions: import parser def load_suite(source_string): st = parser.suite(source_string) return st, st.compile() def load_expression(source_string): st = parser.expr(source_string) return st, st.compile()  File: python.info, Node: ast — Abstract Syntax Trees, Next: symtable — Access to the compiler’s symbol tables, Prev: parser — Access Python parse trees, Up: Python Language Services 5.32.2 ‘ast’ — Abstract Syntax Trees ------------------------------------ `Source code:' Lib/ast.py(1) __________________________________________________________________ The *note ast: 8. module helps Python applications to process trees of the Python abstract syntax grammar. The abstract syntax itself might change with each Python release; this module helps to find out programmatically what the current grammar looks like. An abstract syntax tree can be generated by passing ‘ast.PyCF_ONLY_AST’ as a flag to the *note compile(): 1b4. built-in function, or using the *note parse(): 1a1. helper provided in this module. The result will be a tree of objects whose classes all inherit from *note ast.AST: 3508. An abstract syntax tree can be compiled into a Python code object using the built-in *note compile(): 1b4. function. * Menu: * Node classes:: * Abstract Grammar:: * ast Helpers:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/ast.py  File: python.info, Node: Node classes, Next: Abstract Grammar, Up: ast — Abstract Syntax Trees 5.32.2.1 Node classes ..................... -- Class: ast.AST This is the base of all AST node classes. The actual node classes are derived from the ‘Parser/Python.asdl’ file, which is reproduced *note below: 350a. They are defined in the ‘_ast’ C module and re-exported in *note ast: 8. There is one class defined for each left-hand side symbol in the abstract grammar (for example, ‘ast.stmt’ or ‘ast.expr’). In addition, there is one class defined for each constructor on the right-hand side; these classes inherit from the classes for the left-hand side trees. For example, ‘ast.BinOp’ inherits from ‘ast.expr’. For production rules with alternatives (aka “sums”), the left-hand side class is abstract: only instances of specific constructor nodes are ever created. -- Attribute: _fields Each concrete class has an attribute *note _fields: 350b. which gives the names of all child nodes. Each instance of a concrete class has one attribute for each child node, of the type as defined in the grammar. For example, ‘ast.BinOp’ instances have an attribute ‘left’ of type ‘ast.expr’. If these attributes are marked as optional in the grammar (using a question mark), the value might be ‘None’. If the attributes can have zero-or-more values (marked with an asterisk), the values are represented as Python lists. All possible attributes must be present and have valid values when compiling an AST with *note compile(): 1b4. -- Attribute: lineno -- Attribute: col_offset -- Attribute: end_lineno -- Attribute: end_col_offset Instances of ‘ast.expr’ and ‘ast.stmt’ subclasses have *note lineno: 350c, *note col_offset: 350d, *note lineno: 350c, and *note col_offset: 350d. attributes. The *note lineno: 350c. and *note end_lineno: 350e. are the first and last line numbers of source text span (1-indexed so the first line is line 1) and the *note col_offset: 350d. and *note end_col_offset: 350f. are the corresponding UTF-8 byte offsets of the first and last tokens that generated the node. The UTF-8 offset is recorded because the parser uses UTF-8 internally. Note that the end positions are not required by the compiler and are therefore optional. The end offset is `after' the last symbol, for example one can get the source segment of a one-line expression node using ‘source_line[node.col_offset : node.end_col_offset]’. The constructor of a class ‘ast.T’ parses its arguments as follows: * If there are positional arguments, there must be as many as there are items in ‘T._fields’; they will be assigned as attributes of these names. * If there are keyword arguments, they will set the attributes of the same names to the given values. For example, to create and populate an ‘ast.UnaryOp’ node, you could use node = ast.UnaryOp() node.op = ast.USub() node.operand = ast.Constant() node.operand.value = 5 node.operand.lineno = 0 node.operand.col_offset = 0 node.lineno = 0 node.col_offset = 0 or the more compact node = ast.UnaryOp(ast.USub(), ast.Constant(5, lineno=0, col_offset=0), lineno=0, col_offset=0) Changed in version 3.8: Class ‘ast.Constant’ is now used for all constants. Deprecated since version 3.8: Old classes ‘ast.Num’, ‘ast.Str’, ‘ast.Bytes’, ‘ast.NameConstant’ and ‘ast.Ellipsis’ are still available, but they will be removed in future Python releases. In the meanwhile, instantiating them will return an instance of a different class.  File: python.info, Node: Abstract Grammar, Next: ast Helpers, Prev: Node classes, Up: ast — Abstract Syntax Trees 5.32.2.2 Abstract Grammar ......................... The abstract grammar is currently defined as follows: -- ASDL's 5 builtin types are: -- identifier, int, string, object, constant module Python { mod = Module(stmt* body, type_ignore *type_ignores) | Interactive(stmt* body) | Expression(expr body) | FunctionType(expr* argtypes, expr returns) -- not really an actual node but useful in Jython's typesystem. | Suite(stmt* body) stmt = FunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment) | AsyncFunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment) | ClassDef(identifier name, expr* bases, keyword* keywords, stmt* body, expr* decorator_list) | Return(expr? value) | Delete(expr* targets) | Assign(expr* targets, expr value, string? type_comment) | AugAssign(expr target, operator op, expr value) -- 'simple' indicates that we annotate simple name without parens | AnnAssign(expr target, expr annotation, expr? value, int simple) -- use 'orelse' because else is a keyword in target languages | For(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment) | AsyncFor(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment) | While(expr test, stmt* body, stmt* orelse) | If(expr test, stmt* body, stmt* orelse) | With(withitem* items, stmt* body, string? type_comment) | AsyncWith(withitem* items, stmt* body, string? type_comment) | Raise(expr? exc, expr? cause) | Try(stmt* body, excepthandler* handlers, stmt* orelse, stmt* finalbody) | Assert(expr test, expr? msg) | Import(alias* names) | ImportFrom(identifier? module, alias* names, int? level) | Global(identifier* names) | Nonlocal(identifier* names) | Expr(expr value) | Pass | Break | Continue -- XXX Jython will be different -- col_offset is the byte offset in the utf8 string the parser uses attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset) -- BoolOp() can use left & right? expr = BoolOp(boolop op, expr* values) | NamedExpr(expr target, expr value) | BinOp(expr left, operator op, expr right) | UnaryOp(unaryop op, expr operand) | Lambda(arguments args, expr body) | IfExp(expr test, expr body, expr orelse) | Dict(expr* keys, expr* values) | Set(expr* elts) | ListComp(expr elt, comprehension* generators) | SetComp(expr elt, comprehension* generators) | DictComp(expr key, expr value, comprehension* generators) | GeneratorExp(expr elt, comprehension* generators) -- the grammar constrains where yield expressions can occur | Await(expr value) | Yield(expr? value) | YieldFrom(expr value) -- need sequences for compare to distinguish between -- x < 4 < 3 and (x < 4) < 3 | Compare(expr left, cmpop* ops, expr* comparators) | Call(expr func, expr* args, keyword* keywords) | FormattedValue(expr value, int? conversion, expr? format_spec) | JoinedStr(expr* values) | Constant(constant value, string? kind) -- the following expression can appear in assignment context | Attribute(expr value, identifier attr, expr_context ctx) | Subscript(expr value, slice slice, expr_context ctx) | Starred(expr value, expr_context ctx) | Name(identifier id, expr_context ctx) | List(expr* elts, expr_context ctx) | Tuple(expr* elts, expr_context ctx) -- col_offset is the byte offset in the utf8 string the parser uses attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset) expr_context = Load | Store | Del | AugLoad | AugStore | Param slice = Slice(expr? lower, expr? upper, expr? step) | ExtSlice(slice* dims) | Index(expr value) boolop = And | Or operator = Add | Sub | Mult | MatMult | Div | Mod | Pow | LShift | RShift | BitOr | BitXor | BitAnd | FloorDiv unaryop = Invert | Not | UAdd | USub cmpop = Eq | NotEq | Lt | LtE | Gt | GtE | Is | IsNot | In | NotIn comprehension = (expr target, expr iter, expr* ifs, int is_async) excepthandler = ExceptHandler(expr? type, identifier? name, stmt* body) attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset) arguments = (arg* posonlyargs, arg* args, arg? vararg, arg* kwonlyargs, expr* kw_defaults, arg? kwarg, expr* defaults) arg = (identifier arg, expr? annotation, string? type_comment) attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset) -- keyword arguments supplied to call (NULL identifier for **kwargs) keyword = (identifier? arg, expr value) -- import name with optional 'as' alias. alias = (identifier name, identifier? asname) withitem = (expr context_expr, expr? optional_vars) type_ignore = TypeIgnore(int lineno, string tag) }  File: python.info, Node: ast Helpers, Prev: Abstract Grammar, Up: ast — Abstract Syntax Trees 5.32.2.3 ‘ast’ Helpers ...................... Apart from the node classes, the *note ast: 8. module defines these utility functions and classes for traversing abstract syntax trees: -- Function: ast.parse (source, filename='<unknown>', mode='exec', *, type_comments=False, feature_version=None) Parse the source into an AST node. Equivalent to ‘compile(source, filename, mode, ast.PyCF_ONLY_AST)’. If ‘type_comments=True’ is given, the parser is modified to check and return type comments as specified by PEP 484(1) and PEP 526(2). This is equivalent to adding ‘ast.PyCF_TYPE_COMMENTS’ to the flags passed to *note compile(): 1b4. This will report syntax errors for misplaced type comments. Without this flag, type comments will be ignored, and the ‘type_comment’ field on selected AST nodes will always be ‘None’. In addition, the locations of ‘# type: ignore’ comments will be returned as the ‘type_ignores’ attribute of ‘Module’ (otherwise it is always an empty list). In addition, if ‘mode’ is ‘'func_type'’, the input syntax is modified to correspond to PEP 484(3) “signature type comments”, e.g. ‘(str, int) -> List[str]’. Also, setting ‘feature_version’ to a tuple ‘(major, minor)’ will attempt to parse using that Python version’s grammar. Currently ‘major’ must equal to ‘3’. For example, setting ‘feature_version=(3, 4)’ will allow the use of ‘async’ and ‘await’ as variable names. The lowest supported version is ‘(3, 4)’; the highest is ‘sys.version_info[0:2]’. Warning: It is possible to crash the Python interpreter with a sufficiently large/complex string due to stack depth limitations in Python’s AST compiler. Changed in version 3.8: Added ‘type_comments’, ‘mode='func_type'’ and ‘feature_version’. -- Function: ast.literal_eval (node_or_string) Safely evaluate an expression node or a string containing a Python literal or container display. The string or node provided may only consist of the following Python literal structures: strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and ‘None’. This can be used for safely evaluating strings containing Python values from untrusted sources without the need to parse the values oneself. It is not capable of evaluating arbitrarily complex expressions, for example involving operators or indexing. Warning: It is possible to crash the Python interpreter with a sufficiently large/complex string due to stack depth limitations in Python’s AST compiler. Changed in version 3.2: Now allows bytes and set literals. -- Function: ast.get_docstring (node, clean=True) Return the docstring of the given `node' (which must be a ‘FunctionDef’, ‘AsyncFunctionDef’, ‘ClassDef’, or ‘Module’ node), or ‘None’ if it has no docstring. If `clean' is true, clean up the docstring’s indentation with *note inspect.cleandoc(): 3409. Changed in version 3.5: ‘AsyncFunctionDef’ is now supported. -- Function: ast.get_source_segment (source, node, *, padded=False) Get source code segment of the `source' that generated `node'. If some location information (‘lineno’, ‘end_lineno’, ‘col_offset’, or ‘end_col_offset’) is missing, return ‘None’. If `padded' is ‘True’, the first line of a multi-line statement will be padded with spaces to match its original position. New in version 3.8. -- Function: ast.fix_missing_locations (node) When you compile a node tree with *note compile(): 1b4, the compiler expects ‘lineno’ and ‘col_offset’ attributes for every node that supports them. This is rather tedious to fill in for generated nodes, so this helper adds these attributes recursively where not already set, by setting them to the values of the parent node. It works recursively starting at `node'. -- Function: ast.increment_lineno (node, n=1) Increment the line number and end line number of each node in the tree starting at `node' by `n'. This is useful to “move code” to a different location in a file. -- Function: ast.copy_location (new_node, old_node) Copy source location (‘lineno’, ‘col_offset’, ‘end_lineno’, and ‘end_col_offset’) from `old_node' to `new_node' if possible, and return `new_node'. -- Function: ast.iter_fields (node) Yield a tuple of ‘(fieldname, value)’ for each field in ‘node._fields’ that is present on `node'. -- Function: ast.iter_child_nodes (node) Yield all direct child nodes of `node', that is, all fields that are nodes and all items of fields that are lists of nodes. -- Function: ast.walk (node) Recursively yield all descendant nodes in the tree starting at `node' (including `node' itself), in no specified order. This is useful if you only want to modify nodes in place and don’t care about the context. -- Class: ast.NodeVisitor A node visitor base class that walks the abstract syntax tree and calls a visitor function for every node found. This function may return a value which is forwarded by the *note visit(): 3519. method. This class is meant to be subclassed, with the subclass adding visitor methods. -- Method: visit (node) Visit a node. The default implementation calls the method called ‘self.visit_`classname'’ where `classname' is the name of the node class, or *note generic_visit(): 351a. if that method doesn’t exist. -- Method: generic_visit (node) This visitor calls *note visit(): 3519. on all children of the node. Note that child nodes of nodes that have a custom visitor method won’t be visited unless the visitor calls *note generic_visit(): 351a. or visits them itself. Don’t use the *note NodeVisitor: 281. if you want to apply changes to nodes during traversal. For this a special visitor exists (*note NodeTransformer: 351b.) that allows modifications. Deprecated since version 3.8: Methods ‘visit_Num()’, ‘visit_Str()’, ‘visit_Bytes()’, ‘visit_NameConstant()’ and ‘visit_Ellipsis()’ are deprecated now and will not be called in future Python versions. Add the ‘visit_Constant()’ method to handle all constant nodes. -- Class: ast.NodeTransformer A *note NodeVisitor: 281. subclass that walks the abstract syntax tree and allows modification of nodes. The *note NodeTransformer: 351b. will walk the AST and use the return value of the visitor methods to replace or remove the old node. If the return value of the visitor method is ‘None’, the node will be removed from its location, otherwise it is replaced with the return value. The return value may be the original node in which case no replacement takes place. Here is an example transformer that rewrites all occurrences of name lookups (‘foo’) to ‘data['foo']’: class RewriteName(NodeTransformer): def visit_Name(self, node): return Subscript( value=Name(id='data', ctx=Load()), slice=Index(value=Constant(value=node.id)), ctx=node.ctx ) Keep in mind that if the node you’re operating on has child nodes you must either transform the child nodes yourself or call the ‘generic_visit()’ method for the node first. For nodes that were part of a collection of statements (that applies to all statement nodes), the visitor may also return a list of nodes rather than just a single node. If *note NodeTransformer: 351b. introduces new nodes (that weren’t part of original tree) without giving them location information (such as ‘lineno’), *note fix_missing_locations(): 3513. should be called with the new sub-tree to recalculate the location information: tree = ast.parse('foo', mode='eval') new_tree = fix_missing_locations(RewriteName().visit(tree)) Usually you use the transformer like this: node = YourTransformer().visit(node) -- Function: ast.dump (node, annotate_fields=True, include_attributes=False) Return a formatted dump of the tree in `node'. This is mainly useful for debugging purposes. If `annotate_fields' is true (by default), the returned string will show the names and the values for fields. If `annotate_fields' is false, the result string will be more compact by omitting unambiguous field names. Attributes such as line numbers and column offsets are not dumped by default. If this is wanted, `include_attributes' can be set to true. See also ........ Green Tree Snakes(4), an external documentation resource, has good details on working with Python ASTs. ASTTokens(5) annotates Python ASTs with the positions of tokens and text in the source code that generated them. This is helpful for tools that make source code transformations. leoAst.py(6) unifies the token-based and parse-tree-based views of python programs by inserting two-way links between tokens and ast nodes. LibCST(7) parses code as a Concrete Syntax Tree that looks like an ast tree and keeps all formatting details. It’s useful for building automated refactoring (codemod) applications and linters. Parso(8) is a Python parser that supports error recovery and round-trip parsing for different Python versions (in multiple Python versions). Parso is also able to list multiple syntax errors in your python file. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0526 (3) https://www.python.org/dev/peps/pep-0484 (4) https://greentreesnakes.readthedocs.io/ (5) https://asttokens.readthedocs.io/en/latest/user-guide.html (6) http://leoeditor.com/appendices.html#leoast-py (7) https://libcst.readthedocs.io/ (8) https://parso.readthedocs.io  File: python.info, Node: symtable — Access to the compiler’s symbol tables, Next: symbol — Constants used with Python parse trees, Prev: ast — Abstract Syntax Trees, Up: Python Language Services 5.32.3 ‘symtable’ — Access to the compiler’s symbol tables ---------------------------------------------------------- `Source code:' Lib/symtable.py(1) __________________________________________________________________ Symbol tables are generated by the compiler from AST just before bytecode is generated. The symbol table is responsible for calculating the scope of every identifier in the code. *note symtable: fc. provides an interface to examine these tables. * Menu: * Generating Symbol Tables:: * Examining Symbol Tables:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/symtable.py  File: python.info, Node: Generating Symbol Tables, Next: Examining Symbol Tables, Up: symtable — Access to the compiler’s symbol tables 5.32.3.1 Generating Symbol Tables ................................. -- Function: symtable.symtable (code, filename, compile_type) Return the toplevel *note SymbolTable: 3521. for the Python source `code'. `filename' is the name of the file containing the code. `compile_type' is like the `mode' argument to *note compile(): 1b4.  File: python.info, Node: Examining Symbol Tables, Prev: Generating Symbol Tables, Up: symtable — Access to the compiler’s symbol tables 5.32.3.2 Examining Symbol Tables ................................ -- Class: symtable.SymbolTable A namespace table for a block. The constructor is not public. -- Method: get_type () Return the type of the symbol table. Possible values are ‘'class'’, ‘'module'’, and ‘'function'’. -- Method: get_id () Return the table’s identifier. -- Method: get_name () Return the table’s name. This is the name of the class if the table is for a class, the name of the function if the table is for a function, or ‘'top'’ if the table is global (*note get_type(): 3523. returns ‘'module'’). -- Method: get_lineno () Return the number of the first line in the block this table represents. -- Method: is_optimized () Return ‘True’ if the locals in this table can be optimized. -- Method: is_nested () Return ‘True’ if the block is a nested class or function. -- Method: has_children () Return ‘True’ if the block has nested namespaces within it. These can be obtained with *note get_children(): 352a. -- Method: has_exec () Return ‘True’ if the block uses ‘exec’. -- Method: get_identifiers () Return a list of names of symbols in this table. -- Method: lookup (name) Lookup `name' in the table and return a *note Symbol: 352e. instance. -- Method: get_symbols () Return a list of *note Symbol: 352e. instances for names in the table. -- Method: get_children () Return a list of the nested symbol tables. -- Class: symtable.Function A namespace for a function or method. This class inherits *note SymbolTable: 3521. -- Method: get_parameters () Return a tuple containing names of parameters to this function. -- Method: get_locals () Return a tuple containing names of locals in this function. -- Method: get_globals () Return a tuple containing names of globals in this function. -- Method: get_nonlocals () Return a tuple containing names of nonlocals in this function. -- Method: get_frees () Return a tuple containing names of free variables in this function. -- Class: symtable.Class A namespace of a class. This class inherits *note SymbolTable: 3521. -- Method: get_methods () Return a tuple containing the names of methods declared in the class. -- Class: symtable.Symbol An entry in a *note SymbolTable: 3521. corresponding to an identifier in the source. The constructor is not public. -- Method: get_name () Return the symbol’s name. -- Method: is_referenced () Return ‘True’ if the symbol is used in its block. -- Method: is_imported () Return ‘True’ if the symbol is created from an import statement. -- Method: is_parameter () Return ‘True’ if the symbol is a parameter. -- Method: is_global () Return ‘True’ if the symbol is global. -- Method: is_nonlocal () Return ‘True’ if the symbol is nonlocal. -- Method: is_declared_global () Return ‘True’ if the symbol is declared global with a global statement. -- Method: is_local () Return ‘True’ if the symbol is local to its block. -- Method: is_annotated () Return ‘True’ if the symbol is annotated. New in version 3.6. -- Method: is_free () Return ‘True’ if the symbol is referenced in its block, but not assigned to. -- Method: is_assigned () Return ‘True’ if the symbol is assigned to in its block. -- Method: is_namespace () Return ‘True’ if name binding introduces new namespace. If the name is used as the target of a function or class statement, this will be true. For example: >>> table = symtable.symtable("def some_func(): pass", "string", "exec") >>> table.lookup("some_func").is_namespace() True Note that a single name can be bound to multiple objects. If the result is ‘True’, the name may also be bound to other objects, like an int or list, that does not introduce a new namespace. -- Method: get_namespaces () Return a list of namespaces bound to this name. -- Method: get_namespace () Return the namespace bound to this name. If more than one namespace is bound, *note ValueError: 1fb. is raised.  File: python.info, Node: symbol — Constants used with Python parse trees, Next: token — Constants used with Python parse trees, Prev: symtable — Access to the compiler’s symbol tables, Up: Python Language Services 5.32.4 ‘symbol’ — Constants used with Python parse trees -------------------------------------------------------- `Source code:' Lib/symbol.py(1) __________________________________________________________________ This module provides constants which represent the numeric values of internal nodes of the parse tree. Unlike most Python constants, these use lower-case names. Refer to the file ‘Grammar/Grammar’ in the Python distribution for the definitions of the names in the context of the language grammar. The specific numeric values which the names map to may change between Python versions. This module also provides one additional data object: -- Data: symbol.sym_name Dictionary mapping the numeric values of the constants defined in this module back to name strings, allowing more human-readable representation of parse trees to be generated. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/symbol.py  File: python.info, Node: token — Constants used with Python parse trees, Next: keyword — Testing for Python keywords, Prev: symbol — Constants used with Python parse trees, Up: Python Language Services 5.32.5 ‘token’ — Constants used with Python parse trees ------------------------------------------------------- `Source code:' Lib/token.py(1) __________________________________________________________________ This module provides constants which represent the numeric values of leaf nodes of the parse tree (terminal tokens). Refer to the file ‘Grammar/Grammar’ in the Python distribution for the definitions of the names in the context of the language grammar. The specific numeric values which the names map to may change between Python versions. The module also provides a mapping from numeric codes to names and some functions. The functions mirror definitions in the Python C header files. -- Data: token.tok_name Dictionary mapping the numeric values of the constants defined in this module back to name strings, allowing more human-readable representation of parse trees to be generated. -- Function: token.ISTERMINAL (x) Return ‘True’ for terminal token values. -- Function: token.ISNONTERMINAL (x) Return ‘True’ for non-terminal token values. -- Function: token.ISEOF (x) Return ‘True’ if `x' is the marker indicating the end of input. The token constants are: -- Data: token.ENDMARKER -- Data: token.NAME -- Data: token.NUMBER -- Data: token.STRING -- Data: token.NEWLINE -- Data: token.INDENT -- Data: token.DEDENT -- Data: token.LPAR Token value for ‘"("’. -- Data: token.RPAR Token value for ‘")"’. -- Data: token.LSQB Token value for ‘"["’. -- Data: token.RSQB Token value for ‘"]"’. -- Data: token.COLON Token value for ‘":"’. -- Data: token.COMMA Token value for ‘","’. -- Data: token.SEMI Token value for ‘";"’. -- Data: token.PLUS Token value for ‘"+"’. -- Data: token.MINUS Token value for ‘"-"’. -- Data: token.STAR Token value for ‘"*"’. -- Data: token.SLASH Token value for ‘"/"’. -- Data: token.VBAR Token value for ‘"|"’. -- Data: token.AMPER Token value for ‘"&"’. -- Data: token.LESS Token value for ‘"<"’. -- Data: token.GREATER Token value for ‘">"’. -- Data: token.EQUAL Token value for ‘"="’. -- Data: token.DOT Token value for ‘"."’. -- Data: token.PERCENT Token value for ‘"%"’. -- Data: token.LBRACE Token value for ‘"{"’. -- Data: token.RBRACE Token value for ‘"}"’. -- Data: token.EQEQUAL Token value for ‘"=="’. -- Data: token.NOTEQUAL Token value for ‘"!="’. -- Data: token.LESSEQUAL Token value for ‘"<="’. -- Data: token.GREATEREQUAL Token value for ‘">="’. -- Data: token.TILDE Token value for ‘"~"’. -- Data: token.CIRCUMFLEX Token value for ‘"^"’. -- Data: token.LEFTSHIFT Token value for ‘"<<"’. -- Data: token.RIGHTSHIFT Token value for ‘">>"’. -- Data: token.DOUBLESTAR Token value for ‘"**"’. -- Data: token.PLUSEQUAL Token value for ‘"+="’. -- Data: token.MINEQUAL Token value for ‘"-="’. -- Data: token.STAREQUAL Token value for ‘"*="’. -- Data: token.SLASHEQUAL Token value for ‘"/="’. -- Data: token.PERCENTEQUAL Token value for ‘"%="’. -- Data: token.AMPEREQUAL Token value for ‘"&="’. -- Data: token.VBAREQUAL Token value for ‘"|="’. -- Data: token.CIRCUMFLEXEQUAL Token value for ‘"^="’. -- Data: token.LEFTSHIFTEQUAL Token value for ‘"<<="’. -- Data: token.RIGHTSHIFTEQUAL Token value for ‘">>="’. -- Data: token.DOUBLESTAREQUAL Token value for ‘"**="’. -- Data: token.DOUBLESLASH Token value for ‘"//"’. -- Data: token.DOUBLESLASHEQUAL Token value for ‘"//="’. -- Data: token.AT Token value for ‘"@"’. -- Data: token.ATEQUAL Token value for ‘"@="’. -- Data: token.RARROW Token value for ‘"->"’. -- Data: token.ELLIPSIS Token value for ‘"..."’. -- Data: token.COLONEQUAL Token value for ‘":="’. -- Data: token.OP -- Data: token.AWAIT -- Data: token.ASYNC -- Data: token.TYPE_IGNORE -- Data: token.TYPE_COMMENT -- Data: token.ERRORTOKEN -- Data: token.N_TOKENS -- Data: token.NT_OFFSET The following token type values aren’t used by the C tokenizer but are needed for the *note tokenize: 111. module. -- Data: token.COMMENT Token value used to indicate a comment. -- Data: token.NL Token value used to indicate a non-terminating newline. The *note NEWLINE: 3552. token indicates the end of a logical line of Python code; ‘NL’ tokens are generated when a logical line of code is continued over multiple physical lines. -- Data: token.ENCODING Token value that indicates the encoding used to decode the source bytes into text. The first token returned by *note tokenize.tokenize(): c5b. will always be an ‘ENCODING’ token. -- Data: token.TYPE_COMMENT Token value indicating that a type comment was recognized. Such tokens are only produced when *note ast.parse(): 1a1. is invoked with ‘type_comments=True’. Changed in version 3.5: Added *note AWAIT: 3585. and *note ASYNC: 3586. tokens. Changed in version 3.7: Added *note COMMENT: 358c, *note NL: 358d. and *note ENCODING: 358e. tokens. Changed in version 3.7: Removed *note AWAIT: 3585. and *note ASYNC: 3586. tokens. “async” and “await” are now tokenized as *note NAME: 354f. tokens. Changed in version 3.8: Added *note TYPE_COMMENT: 3588, *note TYPE_IGNORE: 3587, *note COLONEQUAL: 3583. Added *note AWAIT: 3585. and *note ASYNC: 3586. tokens back (they’re needed to support parsing older Python versions for *note ast.parse(): 1a1. with ‘feature_version’ set to 6 or lower). ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/token.py  File: python.info, Node: keyword — Testing for Python keywords, Next: tokenize — Tokenizer for Python source, Prev: token — Constants used with Python parse trees, Up: Python Language Services 5.32.6 ‘keyword’ — Testing for Python keywords ---------------------------------------------- `Source code:' Lib/keyword.py(1) __________________________________________________________________ This module allows a Python program to determine if a string is a *note keyword: 1079. -- Function: keyword.iskeyword (s) Return ‘True’ if `s' is a Python *note keyword: 1079. -- Data: keyword.kwlist Sequence containing all the *note keywords: 1079. defined for the interpreter. If any keywords are defined to only be active when particular *note __future__: 0. statements are in effect, these will be included as well. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/keyword.py  File: python.info, Node: tokenize — Tokenizer for Python source, Next: tabnanny — Detection of ambiguous indentation, Prev: keyword — Testing for Python keywords, Up: Python Language Services 5.32.7 ‘tokenize’ — Tokenizer for Python source ----------------------------------------------- `Source code:' Lib/tokenize.py(1) __________________________________________________________________ The *note tokenize: 111. module provides a lexical scanner for Python source code, implemented in Python. The scanner in this module returns comments as tokens as well, making it useful for implementing “pretty-printers”, including colorizers for on-screen displays. To simplify token stream handling, all *note operator: 10b6. and *note delimiter: 10b7. tokens and *note Ellipsis: 12b6. are returned using the generic *note OP: 3584. token type. The exact type can be determined by checking the ‘exact_type’ property on the *note named tuple: aa3. returned from *note tokenize.tokenize(): c5b. * Menu: * Tokenizing Input:: * Command-Line Usage: Command-Line Usage<2>. * Examples: Examples<30>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tokenize.py  File: python.info, Node: Tokenizing Input, Next: Command-Line Usage<2>, Up: tokenize — Tokenizer for Python source 5.32.7.1 Tokenizing Input ......................... The primary entry point is a *note generator: 9a2.: -- Function: tokenize.tokenize (readline) The *note tokenize(): c5b. generator requires one argument, `readline', which must be a callable object which provides the same interface as the *note io.IOBase.readline(): 13ae. method of file objects. Each call to the function should return one line of input as bytes. The generator produces 5-tuples with these members: the token type; the token string; a 2-tuple ‘(srow, scol)’ of ints specifying the row and column where the token begins in the source; a 2-tuple ‘(erow, ecol)’ of ints specifying the row and column where the token ends in the source; and the line on which the token was found. The line passed (the last tuple item) is the `physical' line. The 5 tuple is returned as a *note named tuple: aa3. with the field names: ‘type string start end line’. The returned *note named tuple: aa3. has an additional property named ‘exact_type’ that contains the exact operator type for *note OP: 3584. tokens. For all other token types ‘exact_type’ equals the named tuple ‘type’ field. Changed in version 3.1: Added support for named tuples. Changed in version 3.3: Added support for ‘exact_type’. *note tokenize(): c5b. determines the source encoding of the file by looking for a UTF-8 BOM or encoding cookie, according to PEP 263(1). -- Function: tokenize.generate_tokens (readline) Tokenize a source reading unicode strings instead of bytes. Like *note tokenize(): c5b, the `readline' argument is a callable returning a single line of input. However, *note generate_tokens(): 3595. expects `readline' to return a str object rather than bytes. The result is an iterator yielding named tuples, exactly like *note tokenize(): c5b. It does not yield an *note ENCODING: 358e. token. All constants from the *note token: 110. module are also exported from *note tokenize: 111. Another function is provided to reverse the tokenization process. This is useful for creating tools that tokenize a script, modify the token stream, and write back the modified script. -- Function: tokenize.untokenize (iterable) Converts tokens back into Python source code. The `iterable' must return sequences with at least two elements, the token type and the token string. Any additional sequence elements are ignored. The reconstructed script is returned as a single string. The result is guaranteed to tokenize back to match the input so that the conversion is lossless and round-trips are assured. The guarantee applies only to the token type and token string as the spacing between tokens (column positions) may change. It returns bytes, encoded using the *note ENCODING: 358e. token, which is the first token sequence output by *note tokenize(): c5b. If there is no encoding token in the input, it returns a str instead. *note tokenize(): c5b. needs to detect the encoding of source files it tokenizes. The function it uses to do this is available: -- Function: tokenize.detect_encoding (readline) The *note detect_encoding(): 1940. function is used to detect the encoding that should be used to decode a Python source file. It requires one argument, readline, in the same way as the *note tokenize(): c5b. generator. It will call readline a maximum of twice, and return the encoding used (as a string) and a list of any lines (not decoded from bytes) it has read in. It detects the encoding from the presence of a UTF-8 BOM or an encoding cookie as specified in PEP 263(2). If both a BOM and a cookie are present, but disagree, a *note SyntaxError: 458. will be raised. Note that if the BOM is found, ‘'utf-8-sig'’ will be returned as an encoding. If no encoding is specified, then the default of ‘'utf-8'’ will be returned. Use *note open(): 193f. to open Python source files: it uses *note detect_encoding(): 1940. to detect the file encoding. -- Function: tokenize.open (filename) Open a file in read only mode using the encoding detected by *note detect_encoding(): 1940. New in version 3.2. -- Exception: tokenize.TokenError Raised when either a docstring or expression that may be split over several lines is not completed anywhere in the file, for example: """Beginning of docstring or: [1, 2, 3 Note that unclosed single-quoted strings do not cause an error to be raised. They are tokenized as *note ERRORTOKEN: 3589, followed by the tokenization of their contents. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0263 (2) https://www.python.org/dev/peps/pep-0263  File: python.info, Node: Command-Line Usage<2>, Next: Examples<30>, Prev: Tokenizing Input, Up: tokenize — Tokenizer for Python source 5.32.7.2 Command-Line Usage ........................... New in version 3.3. The *note tokenize: 111. module can be executed as a script from the command line. It is as simple as: python -m tokenize [-e] [filename.py] The following options are accepted: -- Program Option: -h, --help show this help message and exit -- Program Option: -e, --exact display token names using the exact type If ‘filename.py’ is specified its contents are tokenized to stdout. Otherwise, tokenization is performed on stdin.  File: python.info, Node: Examples<30>, Prev: Command-Line Usage<2>, Up: tokenize — Tokenizer for Python source 5.32.7.3 Examples ................. Example of a script rewriter that transforms float literals into Decimal objects: from tokenize import tokenize, untokenize, NUMBER, STRING, NAME, OP from io import BytesIO def decistmt(s): """Substitute Decimals for floats in a string of statements. >>> from decimal import Decimal >>> s = 'print(+21.3e-5*-.1234/81.7)' >>> decistmt(s) "print (+Decimal ('21.3e-5')*-Decimal ('.1234')/Decimal ('81.7'))" The format of the exponent is inherited from the platform C library. Known cases are "e-007" (Windows) and "e-07" (not Windows). Since we're only showing 12 digits, and the 13th isn't close to 5, the rest of the output should be platform-independent. >>> exec(s) #doctest: +ELLIPSIS -3.21716034272e-0...7 Output from calculations with Decimal should be identical across all platforms. >>> exec(decistmt(s)) -3.217160342717258261933904529E-7 """ result = [] g = tokenize(BytesIO(s.encode('utf-8')).readline) # tokenize the string for toknum, tokval, _, _, _ in g: if toknum == NUMBER and '.' in tokval: # replace NUMBER tokens result.extend([ (NAME, 'Decimal'), (OP, '('), (STRING, repr(tokval)), (OP, ')') ]) else: result.append((toknum, tokval)) return untokenize(result).decode('utf-8') Example of tokenizing from the command line. The script: def say_hello(): print("Hello, World!") say_hello() will be tokenized to the following output where the first column is the range of the line/column coordinates where the token is found, the second column is the name of the token, and the final column is the value of the token (if any) $ python -m tokenize hello.py 0,0-0,0: ENCODING 'utf-8' 1,0-1,3: NAME 'def' 1,4-1,13: NAME 'say_hello' 1,13-1,14: OP '(' 1,14-1,15: OP ')' 1,15-1,16: OP ':' 1,16-1,17: NEWLINE '\n' 2,0-2,4: INDENT ' ' 2,4-2,9: NAME 'print' 2,9-2,10: OP '(' 2,10-2,25: STRING '"Hello, World!"' 2,25-2,26: OP ')' 2,26-2,27: NEWLINE '\n' 3,0-3,1: NL '\n' 4,0-4,0: DEDENT '' 4,0-4,9: NAME 'say_hello' 4,9-4,10: OP '(' 4,10-4,11: OP ')' 4,11-4,12: NEWLINE '\n' 5,0-5,0: ENDMARKER '' The exact token type names can be displayed using the *note -e: 359b. option: $ python -m tokenize -e hello.py 0,0-0,0: ENCODING 'utf-8' 1,0-1,3: NAME 'def' 1,4-1,13: NAME 'say_hello' 1,13-1,14: LPAR '(' 1,14-1,15: RPAR ')' 1,15-1,16: COLON ':' 1,16-1,17: NEWLINE '\n' 2,0-2,4: INDENT ' ' 2,4-2,9: NAME 'print' 2,9-2,10: LPAR '(' 2,10-2,25: STRING '"Hello, World!"' 2,25-2,26: RPAR ')' 2,26-2,27: NEWLINE '\n' 3,0-3,1: NL '\n' 4,0-4,0: DEDENT '' 4,0-4,9: NAME 'say_hello' 4,9-4,10: LPAR '(' 4,10-4,11: RPAR ')' 4,11-4,12: NEWLINE '\n' 5,0-5,0: ENDMARKER '' Example of tokenizing a file programmatically, reading unicode strings instead of bytes with *note generate_tokens(): 3595.: import tokenize with tokenize.open('hello.py') as f: tokens = tokenize.generate_tokens(f.readline) for token in tokens: print(token) Or reading bytes directly with *note tokenize(): c5b.: import tokenize with open('hello.py', 'rb') as f: tokens = tokenize.tokenize(f.readline) for token in tokens: print(token)  File: python.info, Node: tabnanny — Detection of ambiguous indentation, Next: pyclbr — Python module browser support, Prev: tokenize — Tokenizer for Python source, Up: Python Language Services 5.32.8 ‘tabnanny’ — Detection of ambiguous indentation ------------------------------------------------------ `Source code:' Lib/tabnanny.py(1) __________________________________________________________________ For the time being this module is intended to be called as a script. However it is possible to import it into an IDE and use the function *note check(): 359f. described below. Note: The API provided by this module is likely to change in future releases; such changes may not be backward compatible. -- Function: tabnanny.check (file_or_dir) If `file_or_dir' is a directory and not a symbolic link, then recursively descend the directory tree named by `file_or_dir', checking all ‘.py’ files along the way. If `file_or_dir' is an ordinary Python source file, it is checked for whitespace related problems. The diagnostic messages are written to standard output using the *note print(): 886. function. -- Data: tabnanny.verbose Flag indicating whether to print verbose messages. This is incremented by the ‘-v’ option if called as a script. -- Data: tabnanny.filename_only Flag indicating whether to print only the filenames of files containing whitespace related problems. This is set to true by the ‘-q’ option if called as a script. -- Exception: tabnanny.NannyNag Raised by *note process_tokens(): 35a3. if detecting an ambiguous indent. Captured and handled in *note check(): 359f. -- Function: tabnanny.process_tokens (tokens) This function is used by *note check(): 359f. to process tokens generated by the *note tokenize: 111. module. See also ........ Module *note tokenize: 111. Lexical scanner for Python source code. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tabnanny.py  File: python.info, Node: pyclbr — Python module browser support, Next: py_compile — Compile Python source files, Prev: tabnanny — Detection of ambiguous indentation, Up: Python Language Services 5.32.9 ‘pyclbr’ — Python module browser support ----------------------------------------------- `Source code:' Lib/pyclbr.py(1) __________________________________________________________________ The *note pyclbr: d8. module provides limited information about the functions, classes, and methods defined in a Python-coded module. The information is sufficient to implement a module browser. The information is extracted from the Python source code rather than by importing the module, so this module is safe to use with untrusted code. This restriction makes it impossible to use this module with modules not implemented in Python, including all standard and optional extension modules. -- Function: pyclbr.readmodule (module, path=None) Return a dictionary mapping module-level class names to class descriptors. If possible, descriptors for imported base classes are included. Parameter `module' is a string with the name of the module to read; it may be the name of a module within a package. If given, `path' is a sequence of directory paths prepended to ‘sys.path’, which is used to locate the module source code. This function is the original interface and is only kept for back compatibility. It returns a filtered version of the following. -- Function: pyclbr.readmodule_ex (module, path=None) Return a dictionary-based tree containing a function or class descriptors for each function and class defined in the module with a ‘def’ or ‘class’ statement. The returned dictionary maps module-level function and class names to their descriptors. Nested objects are entered into the children dictionary of their parent. As with readmodule, `module' names the module to be read and `path' is prepended to sys.path. If the module being read is a package, the returned dictionary has a key ‘'__path__'’ whose value is a list containing the package search path. New in version 3.7: Descriptors for nested definitions. They are accessed through the new children attribute. Each has a new parent attribute. The descriptors returned by these functions are instances of Function and Class classes. Users are not expected to create instances of these classes. * Menu: * Function Objects:: * Class Objects: Class Objects<2>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pyclbr.py  File: python.info, Node: Function Objects, Next: Class Objects<2>, Up: pyclbr — Python module browser support 5.32.9.1 Function Objects ......................... Class ‘Function’ instances describe functions defined by def statements. They have the following attributes: -- Attribute: Function.file Name of the file in which the function is defined. -- Attribute: Function.module The name of the module defining the function described. -- Attribute: Function.name The name of the function. -- Attribute: Function.lineno The line number in the file where the definition starts. -- Attribute: Function.parent For top-level functions, None. For nested functions, the parent. New in version 3.7. -- Attribute: Function.children A dictionary mapping names to descriptors for nested functions and classes. New in version 3.7.  File: python.info, Node: Class Objects<2>, Prev: Function Objects, Up: pyclbr — Python module browser support 5.32.9.2 Class Objects ...................... Class ‘Class’ instances describe classes defined by class statements. They have the same attributes as Functions and two more. -- Attribute: Class.file Name of the file in which the class is defined. -- Attribute: Class.module The name of the module defining the class described. -- Attribute: Class.name The name of the class. -- Attribute: Class.lineno The line number in the file where the definition starts. -- Attribute: Class.parent For top-level classes, None. For nested classes, the parent. New in version 3.7. -- Attribute: Class.children A dictionary mapping names to descriptors for nested functions and classes. New in version 3.7. -- Attribute: Class.super A list of ‘Class’ objects which describe the immediate base classes of the class being described. Classes which are named as superclasses but which are not discoverable by *note readmodule_ex(): 35a7. are listed as a string with the class name instead of as ‘Class’ objects. -- Attribute: Class.methods A dictionary mapping method names to line numbers. This can be derived from the newer children dictionary, but remains for back-compatibility.  File: python.info, Node: py_compile — Compile Python source files, Next: compileall — Byte-compile Python libraries, Prev: pyclbr — Python module browser support, Up: Python Language Services 5.32.10 ‘py_compile’ — Compile Python source files -------------------------------------------------- `Source code:' Lib/py_compile.py(1) __________________________________________________________________ The *note py_compile: d7. module provides a function to generate a byte-code file from a source file, and another function used when the module source file is invoked as a script. Though not often needed, this function can be useful when installing modules for shared use, especially if some of the users may not have permission to write the byte-code cache files in the directory containing the source code. -- Exception: py_compile.PyCompileError Exception raised when an error occurs while attempting to compile the file. -- Function: py_compile.compile (file, cfile=None, dfile=None, doraise=False, optimize=-1, invalidation_mode=PycInvalidationMode.TIMESTAMP, quiet=0) Compile a source file to byte-code and write out the byte-code cache file. The source code is loaded from the file named `file'. The byte-code is written to `cfile', which defaults to the PEP 3147(2)/ PEP 488(3) path, ending in ‘.pyc’. For example, if `file' is ‘/foo/bar/baz.py’ `cfile' will default to ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ for Python 3.2. If `dfile' is specified, it is used as the name of the source file in error messages instead of `file'. If `doraise' is true, a *note PyCompileError: 35bc. is raised when an error is encountered while compiling `file'. If `doraise' is false (the default), an error string is written to ‘sys.stderr’, but no exception is raised. This function returns the path to byte-compiled file, i.e. whatever `cfile' value was used. The `doraise' and `quiet' arguments determine how errors are handled while compiling file. If `quiet' is 0 or 1, and `doraise' is false, the default behaviour is enabled: an error string is written to ‘sys.stderr’, and the function returns ‘None’ instead of a path. If `doraise' is true, a *note PyCompileError: 35bc. is raised instead. However if `quiet' is 2, no message is written, and `doraise' has no effect. If the path that `cfile' becomes (either explicitly specified or computed) is a symlink or non-regular file, *note FileExistsError: 958. will be raised. This is to act as a warning that import will turn those paths into regular files if it is allowed to write byte-compiled files to those paths. This is a side-effect of import using file renaming to place the final byte-compiled file into place to prevent concurrent file writing issues. `optimize' controls the optimization level and is passed to the built-in *note compile(): 1b4. function. The default of ‘-1’ selects the optimization level of the current interpreter. `invalidation_mode' should be a member of the *note PycInvalidationMode: 35bd. enum and controls how the generated bytecode cache is invalidated at runtime. The default is *note PycInvalidationMode.CHECKED_HASH: 35be. if the ‘SOURCE_DATE_EPOCH’ environment variable is set, otherwise the default is *note PycInvalidationMode.TIMESTAMP: 35bf. Changed in version 3.2: Changed default value of `cfile' to be PEP 3147(4)-compliant. Previous default was `file' + ‘'c'’ (‘'o'’ if optimization was enabled). Also added the `optimize' parameter. Changed in version 3.4: Changed code to use *note importlib: 9b. for the byte-code cache file writing. This means file creation/writing semantics now match what *note importlib: 9b. does, e.g. permissions, write-and-move semantics, etc. Also added the caveat that *note FileExistsError: 958. is raised if `cfile' is a symlink or non-regular file. Changed in version 3.7: The `invalidation_mode' parameter was added as specified in PEP 552(5). If the ‘SOURCE_DATE_EPOCH’ environment variable is set, `invalidation_mode' will be forced to *note PycInvalidationMode.CHECKED_HASH: 35be. Changed in version 3.7.2: The ‘SOURCE_DATE_EPOCH’ environment variable no longer overrides the value of the `invalidation_mode' argument, and determines its default value instead. Changed in version 3.8: The `quiet' parameter was added. -- Class: py_compile.PycInvalidationMode A enumeration of possible methods the interpreter can use to determine whether a bytecode file is up to date with a source file. The ‘.pyc’ file indicates the desired invalidation mode in its header. See *note Cached bytecode invalidation: 329. for more information on how Python invalidates ‘.pyc’ files at runtime. New in version 3.7. -- Attribute: TIMESTAMP The ‘.pyc’ file includes the timestamp and size of the source file, which Python will compare against the metadata of the source file at runtime to determine if the ‘.pyc’ file needs to be regenerated. -- Attribute: CHECKED_HASH The ‘.pyc’ file includes a hash of the source file content, which Python will compare against the source at runtime to determine if the ‘.pyc’ file needs to be regenerated. -- Attribute: UNCHECKED_HASH Like *note CHECKED_HASH: 35be, the ‘.pyc’ file includes a hash of the source file content. However, Python will at runtime assume the ‘.pyc’ file is up to date and not validate the ‘.pyc’ against the source file at all. This option is useful when the ‘.pycs’ are kept up to date by some system external to Python like a build system. -- Function: py_compile.main (args=None) Compile several source files. The files named in `args' (or on the command line, if `args' is ‘None’) are compiled and the resulting byte-code is cached in the normal manner. This function does not search a directory structure to locate source files; it only compiles files named explicitly. If ‘'-'’ is the only parameter in args, the list of files is taken from standard input. Changed in version 3.2: Added support for ‘'-'’. When this module is run as a script, the *note main(): 35c1. is used to compile all the files named on the command line. The exit status is nonzero if one of the files could not be compiled. See also ........ Module *note compileall: 21. Utilities to compile all Python source files in a directory tree. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/py_compile.py (2) https://www.python.org/dev/peps/pep-3147 (3) https://www.python.org/dev/peps/pep-0488 (4) https://www.python.org/dev/peps/pep-3147 (5) https://www.python.org/dev/peps/pep-0552  File: python.info, Node: compileall — Byte-compile Python libraries, Next: dis — Disassembler for Python bytecode, Prev: py_compile — Compile Python source files, Up: Python Language Services 5.32.11 ‘compileall’ — Byte-compile Python libraries ---------------------------------------------------- `Source code:' Lib/compileall.py(1) __________________________________________________________________ This module provides some utility functions to support installing Python libraries. These functions compile Python source files in a directory tree. This module can be used to create the cached byte-code files at library installation time, which makes them available for use even by users who don’t have write permission to the library directories. * Menu: * Command-line use:: * Public functions:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/compileall.py  File: python.info, Node: Command-line use, Next: Public functions, Up: compileall — Byte-compile Python libraries 5.32.11.1 Command-line use .......................... This module can work as a script (using ‘python -m compileall’) to compile Python sources. -- Program Option: directory ... -- Program Option: file ... Positional arguments are files to compile or directories that contain source files, traversed recursively. If no argument is given, behave as if the command line was ‘-l <directories from sys.path>’. -- Program Option: -l Do not recurse into subdirectories, only compile source code files directly contained in the named or implied directories. -- Program Option: -f Force rebuild even if timestamps are up-to-date. -- Program Option: -q Do not print the list of files compiled. If passed once, error messages will still be printed. If passed twice (‘-qq’), all output is suppressed. -- Program Option: -d destdir Directory prepended to the path to each file being compiled. This will appear in compilation time tracebacks, and is also compiled in to the byte-code file, where it will be used in tracebacks and other messages in cases where the source file does not exist at the time the byte-code file is executed. -- Program Option: -x regex regex is used to search the full path to each file considered for compilation, and if the regex produces a match, the file is skipped. -- Program Option: -i list Read the file ‘list’ and add each line that it contains to the list of files and directories to compile. If ‘list’ is ‘-’, read lines from ‘stdin’. -- Program Option: -b Write the byte-code files to their legacy locations and names, which may overwrite byte-code files created by another version of Python. The default is to write files to their PEP 3147(1) locations and names, which allows byte-code files from multiple versions of Python to coexist. -- Program Option: -r Control the maximum recursion level for subdirectories. If this is given, then ‘-l’ option will not be taken into account. ‘python -m compileall <directory> -r 0’ is equivalent to ‘python -m compileall <directory> -l’. -- Program Option: -j N Use `N' workers to compile the files within the given directory. If ‘0’ is used, then the result of *note os.cpu_count(): 87f. will be used. -- Program Option: --invalidation-mode [timestamp|checked-hash|unchecked-hash] Control how the generated byte-code files are invalidated at runtime. The ‘timestamp’ value, means that ‘.pyc’ files with the source timestamp and size embedded will be generated. The ‘checked-hash’ and ‘unchecked-hash’ values cause hash-based pycs to be generated. Hash-based pycs embed a hash of the source file contents rather than a timestamp. See *note Cached bytecode invalidation: 329. for more information on how Python validates bytecode cache files at runtime. The default is ‘timestamp’ if the ‘SOURCE_DATE_EPOCH’ environment variable is not set, and ‘checked-hash’ if the ‘SOURCE_DATE_EPOCH’ environment variable is set. Changed in version 3.2: Added the ‘-i’, ‘-b’ and ‘-h’ options. Changed in version 3.5: Added the ‘-j’, ‘-r’, and ‘-qq’ options. ‘-q’ option was changed to a multilevel value. ‘-b’ will always produce a byte-code file ending in ‘.pyc’, never ‘.pyo’. Changed in version 3.7: Added the ‘--invalidation-mode’ option. There is no command-line option to control the optimization level used by the *note compile(): 1b4. function, because the Python interpreter itself already provides the option: ‘python -O -m compileall’. Similarly, the *note compile(): 1b4. function respects the *note sys.pycache_prefix: 156. setting. The generated bytecode cache will only be useful if *note compile(): 1b4. is run with the same *note sys.pycache_prefix: 156. (if any) that will be used at runtime. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: Public functions, Prev: Command-line use, Up: compileall — Byte-compile Python libraries 5.32.11.2 Public functions .......................... -- Function: compileall.compile_dir (dir, maxlevels=10, ddir=None, force=False, rx=None, quiet=0, legacy=False, optimize=-1, workers=1, invalidation_mode=None) Recursively descend the directory tree named by `dir', compiling all ‘.py’ files along the way. Return a true value if all the files compiled successfully, and a false value otherwise. The `maxlevels' parameter is used to limit the depth of the recursion; it defaults to ‘10’. If `ddir' is given, it is prepended to the path to each file being compiled for use in compilation time tracebacks, and is also compiled in to the byte-code file, where it will be used in tracebacks and other messages in cases where the source file does not exist at the time the byte-code file is executed. If `force' is true, modules are re-compiled even if the timestamps are up to date. If `rx' is given, its search method is called on the complete path to each file considered for compilation, and if it returns a true value, the file is skipped. If `quiet' is ‘False’ or ‘0’ (the default), the filenames and other information are printed to standard out. Set to ‘1’, only errors are printed. Set to ‘2’, all output is suppressed. If `legacy' is true, byte-code files are written to their legacy locations and names, which may overwrite byte-code files created by another version of Python. The default is to write files to their PEP 3147(1) locations and names, which allows byte-code files from multiple versions of Python to coexist. `optimize' specifies the optimization level for the compiler. It is passed to the built-in *note compile(): 1b4. function. The argument `workers' specifies how many workers are used to compile files in parallel. The default is to not use multiple workers. If the platform can’t use multiple workers and `workers' argument is given, then sequential compilation will be used as a fallback. If `workers' is 0, the number of cores in the system is used. If `workers' is lower than ‘0’, a *note ValueError: 1fb. will be raised. `invalidation_mode' should be a member of the *note py_compile.PycInvalidationMode: 35bd. enum and controls how the generated pycs are invalidated at runtime. Changed in version 3.2: Added the `legacy' and `optimize' parameter. Changed in version 3.5: Added the `workers' parameter. Changed in version 3.5: `quiet' parameter was changed to a multilevel value. Changed in version 3.5: The `legacy' parameter only writes out ‘.pyc’ files, not ‘.pyo’ files no matter what the value of `optimize' is. Changed in version 3.6: Accepts a *note path-like object: 36a. Changed in version 3.7: The `invalidation_mode' parameter was added. Changed in version 3.7.2: The `invalidation_mode' parameter’s default value is updated to None. Changed in version 3.8: Setting `workers' to 0 now chooses the optimal number of cores. -- Function: compileall.compile_file (fullname, ddir=None, force=False, rx=None, quiet=0, legacy=False, optimize=-1, invalidation_mode=None) Compile the file with path `fullname'. Return a true value if the file compiled successfully, and a false value otherwise. If `ddir' is given, it is prepended to the path to the file being compiled for use in compilation time tracebacks, and is also compiled in to the byte-code file, where it will be used in tracebacks and other messages in cases where the source file does not exist at the time the byte-code file is executed. If `rx' is given, its search method is passed the full path name to the file being compiled, and if it returns a true value, the file is not compiled and ‘True’ is returned. If `quiet' is ‘False’ or ‘0’ (the default), the filenames and other information are printed to standard out. Set to ‘1’, only errors are printed. Set to ‘2’, all output is suppressed. If `legacy' is true, byte-code files are written to their legacy locations and names, which may overwrite byte-code files created by another version of Python. The default is to write files to their PEP 3147(2) locations and names, which allows byte-code files from multiple versions of Python to coexist. `optimize' specifies the optimization level for the compiler. It is passed to the built-in *note compile(): 1b4. function. `invalidation_mode' should be a member of the *note py_compile.PycInvalidationMode: 35bd. enum and controls how the generated pycs are invalidated at runtime. New in version 3.2. Changed in version 3.5: `quiet' parameter was changed to a multilevel value. Changed in version 3.5: The `legacy' parameter only writes out ‘.pyc’ files, not ‘.pyo’ files no matter what the value of `optimize' is. Changed in version 3.7: The `invalidation_mode' parameter was added. Changed in version 3.7.2: The `invalidation_mode' parameter’s default value is updated to None. -- Function: compileall.compile_path (skip_curdir=True, maxlevels=0, force=False, quiet=0, legacy=False, optimize=-1, invalidation_mode=None) Byte-compile all the ‘.py’ files found along ‘sys.path’. Return a true value if all the files compiled successfully, and a false value otherwise. If `skip_curdir' is true (the default), the current directory is not included in the search. All other parameters are passed to the *note compile_dir(): 372. function. Note that unlike the other compile functions, ‘maxlevels’ defaults to ‘0’. Changed in version 3.2: Added the `legacy' and `optimize' parameter. Changed in version 3.5: `quiet' parameter was changed to a multilevel value. Changed in version 3.5: The `legacy' parameter only writes out ‘.pyc’ files, not ‘.pyo’ files no matter what the value of `optimize' is. Changed in version 3.7: The `invalidation_mode' parameter was added. Changed in version 3.7.2: The `invalidation_mode' parameter’s default value is updated to None. To force a recompile of all the ‘.py’ files in the ‘Lib/’ subdirectory and all its subdirectories: import compileall compileall.compile_dir('Lib/', force=True) # Perform same compilation, excluding files in .svn directories. import re compileall.compile_dir('Lib/', rx=re.compile(r'[/\\][.]svn'), force=True) # pathlib.Path objects can also be used. import pathlib compileall.compile_dir(pathlib.Path('Lib/'), force=True) See also ........ Module *note py_compile: d7. Byte-compile a single source file. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147 (2) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: dis — Disassembler for Python bytecode, Next: pickletools — Tools for pickle developers, Prev: compileall — Byte-compile Python libraries, Up: Python Language Services 5.32.12 ‘dis’ — Disassembler for Python bytecode ------------------------------------------------ `Source code:' Lib/dis.py(1) __________________________________________________________________ The *note dis: 38. module supports the analysis of CPython *note bytecode: 614. by disassembling it. The CPython bytecode which this module takes as an input is defined in the file ‘Include/opcode.h’ and used by the compiler and the interpreter. `CPython implementation detail:' Bytecode is an implementation detail of the CPython interpreter. No guarantees are made that bytecode will not be added, removed, or changed between versions of Python. Use of this module should not be considered to work across Python VMs or Python releases. Changed in version 3.6: Use 2 bytes for each instruction. Previously the number of bytes varied by instruction. Example: Given the function ‘myfunc()’: def myfunc(alist): return len(alist) the following command can be used to display the disassembly of ‘myfunc()’: >>> dis.dis(myfunc) 2 0 LOAD_GLOBAL 0 (len) 2 LOAD_FAST 0 (alist) 4 CALL_FUNCTION 1 6 RETURN_VALUE (The “2” is a line number). * Menu: * Bytecode analysis:: * Analysis functions:: * Python Bytecode Instructions:: * Opcode collections:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/dis.py  File: python.info, Node: Bytecode analysis, Next: Analysis functions, Up: dis — Disassembler for Python bytecode 5.32.12.1 Bytecode analysis ........................... New in version 3.4. The bytecode analysis API allows pieces of Python code to be wrapped in a *note Bytecode: 837. object that provides easy access to details of the compiled code. -- Class: dis.Bytecode (x, *, first_line=None, current_offset=None) Analyse the bytecode corresponding to a function, generator, asynchronous generator, coroutine, method, string of source code, or a code object (as returned by *note compile(): 1b4.). This is a convenience wrapper around many of the functions listed below, most notably *note get_instructions(): 836, as iterating over a *note Bytecode: 837. instance yields the bytecode operations as *note Instruction: 835. instances. If `first_line' is not ‘None’, it indicates the line number that should be reported for the first source line in the disassembled code. Otherwise, the source line information (if any) is taken directly from the disassembled code object. If `current_offset' is not ‘None’, it refers to an instruction offset in the disassembled code. Setting this means *note dis(): 838. will display a “current instruction” marker against the specified opcode. -- Method: classmethod from_traceback (tb) Construct a *note Bytecode: 837. instance from the given traceback, setting `current_offset' to the instruction responsible for the exception. -- Data: codeobj The compiled code object. -- Data: first_line The first source line of the code object (if available) -- Method: dis () Return a formatted view of the bytecode operations (the same as printed by *note dis.dis(): 384, but returned as a multi-line string). -- Method: info () Return a formatted multi-line string with detailed information about the code object, like *note code_info(): bce. Changed in version 3.7: This can now handle coroutine and asynchronous generator objects. Example: >>> bytecode = dis.Bytecode(myfunc) >>> for instr in bytecode: ... print(instr.opname) ... LOAD_GLOBAL LOAD_FAST CALL_FUNCTION RETURN_VALUE  File: python.info, Node: Analysis functions, Next: Python Bytecode Instructions, Prev: Bytecode analysis, Up: dis — Disassembler for Python bytecode 5.32.12.2 Analysis functions ............................ The *note dis: 38. module also defines the following analysis functions that convert the input directly to the desired output. They can be useful if only a single operation is being performed, so the intermediate analysis object isn’t useful: -- Function: dis.code_info (x) Return a formatted multi-line string with detailed code object information for the supplied function, generator, asynchronous generator, coroutine, method, source code string or code object. Note that the exact contents of code info strings are highly implementation dependent and they may change arbitrarily across Python VMs or Python releases. New in version 3.2. Changed in version 3.7: This can now handle coroutine and asynchronous generator objects. -- Function: dis.show_code (x, *, file=None) Print detailed code object information for the supplied function, method, source code string or code object to `file' (or ‘sys.stdout’ if `file' is not specified). This is a convenient shorthand for ‘print(code_info(x), file=file)’, intended for interactive exploration at the interpreter prompt. New in version 3.2. Changed in version 3.4: Added `file' parameter. -- Function: dis.dis (x=None, *, file=None, depth=None) Disassemble the `x' object. `x' can denote either a module, a class, a method, a function, a generator, an asynchronous generator, a coroutine, a code object, a string of source code or a byte sequence of raw bytecode. For a module, it disassembles all functions. For a class, it disassembles all methods (including class and static methods). For a code object or sequence of raw bytecode, it prints one line per bytecode instruction. It also recursively disassembles nested code objects (the code of comprehensions, generator expressions and nested functions, and the code used for building nested classes). Strings are first compiled to code objects with the *note compile(): 1b4. built-in function before being disassembled. If no object is provided, this function disassembles the last traceback. The disassembly is written as text to the supplied `file' argument if provided and to ‘sys.stdout’ otherwise. The maximal depth of recursion is limited by `depth' unless it is ‘None’. ‘depth=0’ means no recursion. Changed in version 3.4: Added `file' parameter. Changed in version 3.7: Implemented recursive disassembling and added `depth' parameter. Changed in version 3.7: This can now handle coroutine and asynchronous generator objects. -- Function: dis.distb (tb=None, *, file=None) Disassemble the top-of-stack function of a traceback, using the last traceback if none was passed. The instruction causing the exception is indicated. The disassembly is written as text to the supplied `file' argument if provided and to ‘sys.stdout’ otherwise. Changed in version 3.4: Added `file' parameter. -- Function: dis.disassemble (code, lasti=-1, *, file=None) -- Function: dis.disco (code, lasti=-1, *, file=None) Disassemble a code object, indicating the last instruction if `lasti' was provided. The output is divided in the following columns: 1. the line number, for the first instruction of each line 2. the current instruction, indicated as ‘-->’, 3. a labelled instruction, indicated with ‘>>’, 4. the address of the instruction, 5. the operation code name, 6. operation parameters, and 7. interpretation of the parameters in parentheses. The parameter interpretation recognizes local and global variable names, constant values, branch targets, and compare operators. The disassembly is written as text to the supplied `file' argument if provided and to ‘sys.stdout’ otherwise. Changed in version 3.4: Added `file' parameter. -- Function: dis.get_instructions (x, *, first_line=None) Return an iterator over the instructions in the supplied function, method, source code string or code object. The iterator generates a series of *note Instruction: 835. named tuples giving the details of each operation in the supplied code. If `first_line' is not ‘None’, it indicates the line number that should be reported for the first source line in the disassembled code. Otherwise, the source line information (if any) is taken directly from the disassembled code object. New in version 3.4. -- Function: dis.findlinestarts (code) This generator function uses the ‘co_firstlineno’ and ‘co_lnotab’ attributes of the code object `code' to find the offsets which are starts of lines in the source code. They are generated as ‘(offset, lineno)’ pairs. See Objects/lnotab_notes.txt(1) for the ‘co_lnotab’ format and how to decode it. Changed in version 3.6: Line numbers can be decreasing. Before, they were always increasing. -- Function: dis.findlabels (code) Detect all offsets in the raw compiled bytecode string `code' which are jump targets, and return a list of these offsets. -- Function: dis.stack_effect (opcode, oparg=None, *, jump=None) Compute the stack effect of `opcode' with argument `oparg'. If the code has a jump target and `jump' is ‘True’, *note stack_effect(): 83a. will return the stack effect of jumping. If `jump' is ‘False’, it will return the stack effect of not jumping. And if `jump' is ‘None’ (default), it will return the maximal stack effect of both cases. New in version 3.4. Changed in version 3.8: Added `jump' parameter. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Objects/lnotab_notes.txt  File: python.info, Node: Python Bytecode Instructions, Next: Opcode collections, Prev: Analysis functions, Up: dis — Disassembler for Python bytecode 5.32.12.3 Python Bytecode Instructions ...................................... The *note get_instructions(): 836. function and *note Bytecode: 837. class provide details of bytecode instructions as *note Instruction: 835. instances: -- Class: dis.Instruction Details for a bytecode operation -- Data: opcode numeric code for operation, corresponding to the opcode values listed below and the bytecode values in the *note Opcode collections: 35df. -- Data: opname human readable name for operation -- Data: arg numeric argument to operation (if any), otherwise ‘None’ -- Data: argval resolved arg value (if known), otherwise same as arg -- Data: argrepr human readable description of operation argument -- Data: offset start index of operation within bytecode sequence -- Data: starts_line line started by this opcode (if any), otherwise ‘None’ -- Data: is_jump_target ‘True’ if other code jumps to here, otherwise ‘False’ New in version 3.4. The Python compiler currently generates the following bytecode instructions. `General instructions' -- Opcode: NOP Do nothing code. Used as a placeholder by the bytecode optimizer. -- Opcode: POP_TOP Removes the top-of-stack (TOS) item. -- Opcode: ROT_TWO Swaps the two top-most stack items. -- Opcode: ROT_THREE Lifts second and third stack item one position up, moves top down to position three. -- Opcode: ROT_FOUR Lifts second, third and fourth stack items one position up, moves top down to position four. New in version 3.8. -- Opcode: DUP_TOP Duplicates the reference on top of the stack. New in version 3.2. -- Opcode: DUP_TOP_TWO Duplicates the two references on top of the stack, leaving them in the same order. New in version 3.2. `Unary operations' Unary operations take the top of the stack, apply the operation, and push the result back on the stack. -- Opcode: UNARY_POSITIVE Implements ‘TOS = +TOS’. -- Opcode: UNARY_NEGATIVE Implements ‘TOS = -TOS’. -- Opcode: UNARY_NOT Implements ‘TOS = not TOS’. -- Opcode: UNARY_INVERT Implements ‘TOS = ~TOS’. -- Opcode: GET_ITER Implements ‘TOS = iter(TOS)’. -- Opcode: GET_YIELD_FROM_ITER If ‘TOS’ is a *note generator iterator: 457. or *note coroutine: 1a6. object it is left as is. Otherwise, implements ‘TOS = iter(TOS)’. New in version 3.5. `Binary operations' Binary operations remove the top of the stack (TOS) and the second top-most stack item (TOS1) from the stack. They perform the operation, and put the result back on the stack. -- Opcode: BINARY_POWER Implements ‘TOS = TOS1 ** TOS’. -- Opcode: BINARY_MULTIPLY Implements ‘TOS = TOS1 * TOS’. -- Opcode: BINARY_MATRIX_MULTIPLY Implements ‘TOS = TOS1 @ TOS’. New in version 3.5. -- Opcode: BINARY_FLOOR_DIVIDE Implements ‘TOS = TOS1 // TOS’. -- Opcode: BINARY_TRUE_DIVIDE Implements ‘TOS = TOS1 / TOS’. -- Opcode: BINARY_MODULO Implements ‘TOS = TOS1 % TOS’. -- Opcode: BINARY_ADD Implements ‘TOS = TOS1 + TOS’. -- Opcode: BINARY_SUBTRACT Implements ‘TOS = TOS1 - TOS’. -- Opcode: BINARY_SUBSCR Implements ‘TOS = TOS1[TOS]’. -- Opcode: BINARY_LSHIFT Implements ‘TOS = TOS1 << TOS’. -- Opcode: BINARY_RSHIFT Implements ‘TOS = TOS1 >> TOS’. -- Opcode: BINARY_AND Implements ‘TOS = TOS1 & TOS’. -- Opcode: BINARY_XOR Implements ‘TOS = TOS1 ^ TOS’. -- Opcode: BINARY_OR Implements ‘TOS = TOS1 | TOS’. `In-place operations' In-place operations are like binary operations, in that they remove TOS and TOS1, and push the result back on the stack, but the operation is done in-place when TOS1 supports it, and the resulting TOS may be (but does not have to be) the original TOS1. -- Opcode: INPLACE_POWER Implements in-place ‘TOS = TOS1 ** TOS’. -- Opcode: INPLACE_MULTIPLY Implements in-place ‘TOS = TOS1 * TOS’. -- Opcode: INPLACE_MATRIX_MULTIPLY Implements in-place ‘TOS = TOS1 @ TOS’. New in version 3.5. -- Opcode: INPLACE_FLOOR_DIVIDE Implements in-place ‘TOS = TOS1 // TOS’. -- Opcode: INPLACE_TRUE_DIVIDE Implements in-place ‘TOS = TOS1 / TOS’. -- Opcode: INPLACE_MODULO Implements in-place ‘TOS = TOS1 % TOS’. -- Opcode: INPLACE_ADD Implements in-place ‘TOS = TOS1 + TOS’. -- Opcode: INPLACE_SUBTRACT Implements in-place ‘TOS = TOS1 - TOS’. -- Opcode: INPLACE_LSHIFT Implements in-place ‘TOS = TOS1 << TOS’. -- Opcode: INPLACE_RSHIFT Implements in-place ‘TOS = TOS1 >> TOS’. -- Opcode: INPLACE_AND Implements in-place ‘TOS = TOS1 & TOS’. -- Opcode: INPLACE_XOR Implements in-place ‘TOS = TOS1 ^ TOS’. -- Opcode: INPLACE_OR Implements in-place ‘TOS = TOS1 | TOS’. -- Opcode: STORE_SUBSCR Implements ‘TOS1[TOS] = TOS2’. -- Opcode: DELETE_SUBSCR Implements ‘del TOS1[TOS]’. `Coroutine opcodes' -- Opcode: GET_AWAITABLE Implements ‘TOS = get_awaitable(TOS)’, where ‘get_awaitable(o)’ returns ‘o’ if ‘o’ is a coroutine object or a generator object with the CO_ITERABLE_COROUTINE flag, or resolves ‘o.__await__’. New in version 3.5. -- Opcode: GET_AITER Implements ‘TOS = TOS.__aiter__()’. New in version 3.5. Changed in version 3.7: Returning awaitable objects from ‘__aiter__’ is no longer supported. -- Opcode: GET_ANEXT Implements ‘PUSH(get_awaitable(TOS.__anext__()))’. See ‘GET_AWAITABLE’ for details about ‘get_awaitable’ New in version 3.5. -- Opcode: END_ASYNC_FOR Terminates an *note async for: 2e3. loop. Handles an exception raised when awaiting a next item. If TOS is *note StopAsyncIteration: 10cd. pop 7 values from the stack and restore the exception state using the second three of them. Otherwise re-raise the exception using the three values from the stack. An exception handler block is removed from the block stack. New in version 3.8. -- Opcode: BEFORE_ASYNC_WITH Resolves ‘__aenter__’ and ‘__aexit__’ from the object on top of the stack. Pushes ‘__aexit__’ and result of ‘__aenter__()’ to the stack. New in version 3.5. -- Opcode: SETUP_ASYNC_WITH Creates a new frame object. New in version 3.5. `Miscellaneous opcodes' -- Opcode: PRINT_EXPR Implements the expression statement for the interactive mode. TOS is removed from the stack and printed. In non-interactive mode, an expression statement is terminated with *note POP_TOP: 35e8. -- Opcode: SET_ADD (i) Calls ‘set.add(TOS1[-i], TOS)’. Used to implement set comprehensions. -- Opcode: LIST_APPEND (i) Calls ‘list.append(TOS1[-i], TOS)’. Used to implement list comprehensions. -- Opcode: MAP_ADD (i) Calls ‘dict.__setitem__(TOS1[-i], TOS1, TOS)’. Used to implement dict comprehensions. New in version 3.1. Changed in version 3.8: Map value is TOS and map key is TOS1. Before, those were reversed. For all of the *note SET_ADD: 3616, *note LIST_APPEND: 3617. and *note MAP_ADD: 2e4. instructions, while the added value or key/value pair is popped off, the container object remains on the stack so that it is available for further iterations of the loop. -- Opcode: RETURN_VALUE Returns with TOS to the caller of the function. -- Opcode: YIELD_VALUE Pops TOS and yields it from a *note generator: 9a2. -- Opcode: YIELD_FROM Pops TOS and delegates to it as a subiterator from a *note generator: 9a2. New in version 3.3. -- Opcode: SETUP_ANNOTATIONS Checks whether ‘__annotations__’ is defined in ‘locals()’, if not it is set up to an empty ‘dict’. This opcode is only emitted if a class or module body contains *note variable annotations: 61f. statically. New in version 3.6. -- Opcode: IMPORT_STAR Loads all symbols not starting with ‘'_'’ directly from the module TOS to the local namespace. The module is popped after loading all names. This opcode implements ‘from module import *’. -- Opcode: POP_BLOCK Removes one block from the block stack. Per frame, there is a stack of blocks, denoting *note try: d72. statements, and such. -- Opcode: POP_EXCEPT Removes one block from the block stack. The popped block must be an exception handler block, as implicitly created when entering an except handler. In addition to popping extraneous values from the frame stack, the last three popped values are used to restore the exception state. -- Opcode: POP_FINALLY (preserve_tos) Cleans up the value stack and the block stack. If `preserve_tos' is not ‘0’ TOS first is popped from the stack and pushed on the stack after performing other stack operations: * If TOS is ‘NULL’ or an integer (pushed by *note BEGIN_FINALLY: 2dd. or *note CALL_FINALLY: 2de.) it is popped from the stack. * If TOS is an exception type (pushed when an exception has been raised) 6 values are popped from the stack, the last three popped values are used to restore the exception state. An exception handler block is removed from the block stack. It is similar to *note END_FINALLY: 2e0, but doesn’t change the bytecode counter nor raise an exception. Used for implementing *note break: 2db, *note continue: 181. and *note return: 190. in the *note finally: 182. block. New in version 3.8. -- Opcode: BEGIN_FINALLY Pushes ‘NULL’ onto the stack for using it in *note END_FINALLY: 2e0, *note POP_FINALLY: 2df, *note WITH_CLEANUP_START: 2e1. and *note WITH_CLEANUP_FINISH: 361e. Starts the *note finally: 182. block. New in version 3.8. -- Opcode: END_FINALLY Terminates a *note finally: 182. clause. The interpreter recalls whether the exception has to be re-raised or execution has to be continued depending on the value of TOS. * If TOS is ‘NULL’ (pushed by *note BEGIN_FINALLY: 2dd.) continue from the next instruction. TOS is popped. * If TOS is an integer (pushed by *note CALL_FINALLY: 2de.), sets the bytecode counter to TOS. TOS is popped. * If TOS is an exception type (pushed when an exception has been raised) 6 values are popped from the stack, the first three popped values are used to re-raise the exception and the last three popped values are used to restore the exception state. An exception handler block is removed from the block stack. -- Opcode: LOAD_BUILD_CLASS Pushes ‘builtins.__build_class__()’ onto the stack. It is later called by *note CALL_FUNCTION: 619. to construct a class. -- Opcode: SETUP_WITH (delta) This opcode performs several operations before a with block starts. First, it loads *note __exit__(): c96. from the context manager and pushes it onto the stack for later use by *note WITH_CLEANUP_START: 2e1. Then, *note __enter__(): c95. is called, and a finally block pointing to `delta' is pushed. Finally, the result of calling the ‘__enter__()’ method is pushed onto the stack. The next opcode will either ignore it (*note POP_TOP: 35e8.), or store it in (a) variable(s) (*note STORE_FAST: 3621, *note STORE_NAME: 3622, or *note UNPACK_SEQUENCE: 3623.). New in version 3.2. -- Opcode: WITH_CLEANUP_START Starts cleaning up the stack when a *note with: 6e9. statement block exits. At the top of the stack are either ‘NULL’ (pushed by *note BEGIN_FINALLY: 2dd.) or 6 values pushed if an exception has been raised in the with block. Below is the context manager’s *note __exit__(): c96. or *note __aexit__(): 113c. bound method. If TOS is ‘NULL’, calls ‘SECOND(None, None, None)’, removes the function from the stack, leaving TOS, and pushes ‘None’ to the stack. Otherwise calls ‘SEVENTH(TOP, SECOND, THIRD)’, shifts the bottom 3 values of the stack down, replaces the empty spot with ‘NULL’ and pushes TOS. Finally pushes the result of the call. -- Opcode: WITH_CLEANUP_FINISH Finishes cleaning up the stack when a *note with: 6e9. statement block exits. TOS is result of ‘__exit__()’ or ‘__aexit__()’ function call pushed by *note WITH_CLEANUP_START: 2e1. SECOND is ‘None’ or an exception type (pushed when an exception has been raised). Pops two values from the stack. If SECOND is not None and TOS is true unwinds the EXCEPT_HANDLER block which was created when the exception was caught and pushes ‘NULL’ to the stack. All of the following opcodes use their arguments. -- Opcode: STORE_NAME (namei) Implements ‘name = TOS’. `namei' is the index of `name' in the attribute ‘co_names’ of the code object. The compiler tries to use *note STORE_FAST: 3621. or *note STORE_GLOBAL: 3624. if possible. -- Opcode: DELETE_NAME (namei) Implements ‘del name’, where `namei' is the index into ‘co_names’ attribute of the code object. -- Opcode: UNPACK_SEQUENCE (count) Unpacks TOS into `count' individual values, which are put onto the stack right-to-left. -- Opcode: UNPACK_EX (counts) Implements assignment with a starred target: Unpacks an iterable in TOS into individual values, where the total number of values can be smaller than the number of items in the iterable: one of the new values will be a list of all leftover items. The low byte of `counts' is the number of values before the list value, the high byte of `counts' the number of values after it. The resulting values are put onto the stack right-to-left. -- Opcode: STORE_ATTR (namei) Implements ‘TOS.name = TOS1’, where `namei' is the index of name in ‘co_names’. -- Opcode: DELETE_ATTR (namei) Implements ‘del TOS.name’, using `namei' as index into ‘co_names’. -- Opcode: STORE_GLOBAL (namei) Works as *note STORE_NAME: 3622, but stores the name as a global. -- Opcode: DELETE_GLOBAL (namei) Works as *note DELETE_NAME: 3625, but deletes a global name. -- Opcode: LOAD_CONST (consti) Pushes ‘co_consts[consti]’ onto the stack. -- Opcode: LOAD_NAME (namei) Pushes the value associated with ‘co_names[namei]’ onto the stack. -- Opcode: BUILD_TUPLE (count) Creates a tuple consuming `count' items from the stack, and pushes the resulting tuple onto the stack. -- Opcode: BUILD_LIST (count) Works as *note BUILD_TUPLE: 362c, but creates a list. -- Opcode: BUILD_SET (count) Works as *note BUILD_TUPLE: 362c, but creates a set. -- Opcode: BUILD_MAP (count) Pushes a new dictionary object onto the stack. Pops ‘2 * count’ items so that the dictionary holds `count' entries: ‘{..., TOS3: TOS2, TOS1: TOS}’. Changed in version 3.5: The dictionary is created from stack items instead of creating an empty dictionary pre-sized to hold `count' items. -- Opcode: BUILD_CONST_KEY_MAP (count) The version of *note BUILD_MAP: 362f. specialized for constant keys. Pops the top element on the stack which contains a tuple of keys, then starting from ‘TOS1’, pops `count' values to form values in the built dictionary. New in version 3.6. -- Opcode: BUILD_STRING (count) Concatenates `count' strings from the stack and pushes the resulting string onto the stack. New in version 3.6. -- Opcode: BUILD_TUPLE_UNPACK (count) Pops `count' iterables from the stack, joins them in a single tuple, and pushes the result. Implements iterable unpacking in tuple displays ‘(*x, *y, *z)’. New in version 3.5. -- Opcode: BUILD_TUPLE_UNPACK_WITH_CALL (count) This is similar to *note BUILD_TUPLE_UNPACK: 3630, but is used for ‘f(*x, *y, *z)’ call syntax. The stack item at position ‘count + 1’ should be the corresponding callable ‘f’. New in version 3.6. -- Opcode: BUILD_LIST_UNPACK (count) This is similar to *note BUILD_TUPLE_UNPACK: 3630, but pushes a list instead of tuple. Implements iterable unpacking in list displays ‘[*x, *y, *z]’. New in version 3.5. -- Opcode: BUILD_SET_UNPACK (count) This is similar to *note BUILD_TUPLE_UNPACK: 3630, but pushes a set instead of tuple. Implements iterable unpacking in set displays ‘{*x, *y, *z}’. New in version 3.5. -- Opcode: BUILD_MAP_UNPACK (count) Pops `count' mappings from the stack, merges them into a single dictionary, and pushes the result. Implements dictionary unpacking in dictionary displays ‘{**x, **y, **z}’. New in version 3.5. -- Opcode: BUILD_MAP_UNPACK_WITH_CALL (count) This is similar to *note BUILD_MAP_UNPACK: 3633, but is used for ‘f(**x, **y, **z)’ call syntax. The stack item at position ‘count + 2’ should be the corresponding callable ‘f’. New in version 3.5. Changed in version 3.6: The position of the callable is determined by adding 2 to the opcode argument instead of encoding it in the second byte of the argument. -- Opcode: LOAD_ATTR (namei) Replaces TOS with ‘getattr(TOS, co_names[namei])’. -- Opcode: COMPARE_OP (opname) Performs a Boolean operation. The operation name can be found in ‘cmp_op[opname]’. -- Opcode: IMPORT_NAME (namei) Imports the module ‘co_names[namei]’. TOS and TOS1 are popped and provide the `fromlist' and `level' arguments of *note __import__(): 610. The module object is pushed onto the stack. The current namespace is not affected: for a proper import statement, a subsequent *note STORE_FAST: 3621. instruction modifies the namespace. -- Opcode: IMPORT_FROM (namei) Loads the attribute ‘co_names[namei]’ from the module found in TOS. The resulting object is pushed onto the stack, to be subsequently stored by a *note STORE_FAST: 3621. instruction. -- Opcode: JUMP_FORWARD (delta) Increments bytecode counter by `delta'. -- Opcode: POP_JUMP_IF_TRUE (target) If TOS is true, sets the bytecode counter to `target'. TOS is popped. New in version 3.1. -- Opcode: POP_JUMP_IF_FALSE (target) If TOS is false, sets the bytecode counter to `target'. TOS is popped. New in version 3.1. -- Opcode: JUMP_IF_TRUE_OR_POP (target) If TOS is true, sets the bytecode counter to `target' and leaves TOS on the stack. Otherwise (TOS is false), TOS is popped. New in version 3.1. -- Opcode: JUMP_IF_FALSE_OR_POP (target) If TOS is false, sets the bytecode counter to `target' and leaves TOS on the stack. Otherwise (TOS is true), TOS is popped. New in version 3.1. -- Opcode: JUMP_ABSOLUTE (target) Set bytecode counter to `target'. -- Opcode: FOR_ITER (delta) TOS is an *note iterator: 112e. Call its *note __next__(): c64. method. If this yields a new value, push it on the stack (leaving the iterator below it). If the iterator indicates it is exhausted TOS is popped, and the byte code counter is incremented by `delta'. -- Opcode: LOAD_GLOBAL (namei) Loads the global named ‘co_names[namei]’ onto the stack. -- Opcode: SETUP_FINALLY (delta) Pushes a try block from a try-finally or try-except clause onto the block stack. `delta' points to the finally block or the first except block. -- Opcode: CALL_FINALLY (delta) Pushes the address of the next instruction onto the stack and increments bytecode counter by `delta'. Used for calling the finally block as a “subroutine”. New in version 3.8. -- Opcode: LOAD_FAST (var_num) Pushes a reference to the local ‘co_varnames[var_num]’ onto the stack. -- Opcode: STORE_FAST (var_num) Stores TOS into the local ‘co_varnames[var_num]’. -- Opcode: DELETE_FAST (var_num) Deletes local ‘co_varnames[var_num]’. -- Opcode: LOAD_CLOSURE (i) Pushes a reference to the cell contained in slot `i' of the cell and free variable storage. The name of the variable is ‘co_cellvars[i]’ if `i' is less than the length of `co_cellvars'. Otherwise it is ‘co_freevars[i - len(co_cellvars)]’. -- Opcode: LOAD_DEREF (i) Loads the cell contained in slot `i' of the cell and free variable storage. Pushes a reference to the object the cell contains on the stack. -- Opcode: LOAD_CLASSDEREF (i) Much like *note LOAD_DEREF: 3644. but first checks the locals dictionary before consulting the cell. This is used for loading free variables in class bodies. New in version 3.4. -- Opcode: STORE_DEREF (i) Stores TOS into the cell contained in slot `i' of the cell and free variable storage. -- Opcode: DELETE_DEREF (i) Empties the cell contained in slot `i' of the cell and free variable storage. Used by the *note del: f02. statement. New in version 3.2. -- Opcode: RAISE_VARARGS (argc) Raises an exception using one of the 3 forms of the ‘raise’ statement, depending on the value of `argc': * 0: ‘raise’ (re-raise previous exception) * 1: ‘raise TOS’ (raise exception instance or type at ‘TOS’) * 2: ‘raise TOS1 from TOS’ (raise exception instance or type at ‘TOS1’ with ‘__cause__’ set to ‘TOS’) -- Opcode: CALL_FUNCTION (argc) Calls a callable object with positional arguments. `argc' indicates the number of positional arguments. The top of the stack contains positional arguments, with the right-most argument on top. Below the arguments is a callable object to call. ‘CALL_FUNCTION’ pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object. Changed in version 3.6: This opcode is used only for calls with positional arguments. -- Opcode: CALL_FUNCTION_KW (argc) Calls a callable object with positional (if any) and keyword arguments. `argc' indicates the total number of positional and keyword arguments. The top element on the stack contains a tuple of keyword argument names. Below that are keyword arguments in the order corresponding to the tuple. Below that are positional arguments, with the right-most parameter on top. Below the arguments is a callable object to call. ‘CALL_FUNCTION_KW’ pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object. Changed in version 3.6: Keyword arguments are packed in a tuple instead of a dictionary, `argc' indicates the total number of arguments. -- Opcode: CALL_FUNCTION_EX (flags) Calls a callable object with variable set of positional and keyword arguments. If the lowest bit of `flags' is set, the top of the stack contains a mapping object containing additional keyword arguments. Below that is an iterable object containing positional arguments and a callable object to call. *note BUILD_MAP_UNPACK_WITH_CALL: 61b. and *note BUILD_TUPLE_UNPACK_WITH_CALL: 61d. can be used for merging multiple mapping objects and iterables containing arguments. Before the callable is called, the mapping object and iterable object are each “unpacked” and their contents passed in as keyword and positional arguments respectively. ‘CALL_FUNCTION_EX’ pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object. New in version 3.6. -- Opcode: LOAD_METHOD (namei) Loads a method named ‘co_names[namei]’ from the TOS object. TOS is popped. This bytecode distinguishes two cases: if TOS has a method with the correct name, the bytecode pushes the unbound method and TOS. TOS will be used as the first argument (‘self’) by *note CALL_METHOD: 4ae. when calling the unbound method. Otherwise, ‘NULL’ and the object return by the attribute lookup are pushed. New in version 3.7. -- Opcode: CALL_METHOD (argc) Calls a method. `argc' is the number of positional arguments. Keyword arguments are not supported. This opcode is designed to be used with *note LOAD_METHOD: 4ad. Positional arguments are on top of the stack. Below them, the two items described in *note LOAD_METHOD: 4ad. are on the stack (either ‘self’ and an unbound method object or ‘NULL’ and an arbitrary callable). All of them are popped and the return value is pushed. New in version 3.7. -- Opcode: MAKE_FUNCTION (flags) Pushes a new function object on the stack. From bottom to top, the consumed stack must consist of values if the argument carries a specified flag value * ‘0x01’ a tuple of default values for positional-only and positional-or-keyword parameters in positional order * ‘0x02’ a dictionary of keyword-only parameters’ default values * ‘0x04’ an annotation dictionary * ‘0x08’ a tuple containing cells for free variables, making a closure * the code associated with the function (at TOS1) * the *note qualified name: 10ca. of the function (at TOS) -- Opcode: BUILD_SLICE (argc) Pushes a slice object on the stack. `argc' must be 2 or 3. If it is 2, ‘slice(TOS1, TOS)’ is pushed; if it is 3, ‘slice(TOS2, TOS1, TOS)’ is pushed. See the *note slice(): e04. built-in function for more information. -- Opcode: EXTENDED_ARG (ext) Prefixes any opcode which has an argument too big to fit into the default one byte. `ext' holds an additional byte which act as higher bits in the argument. For each opcode, at most three prefixal ‘EXTENDED_ARG’ are allowed, forming an argument from two-byte to four-byte. -- Opcode: FORMAT_VALUE (flags) Used for implementing formatted literal strings (f-strings). Pops an optional `fmt_spec' from the stack, then a required `value'. `flags' is interpreted as follows: * ‘(flags & 0x03) == 0x00’: `value' is formatted as-is. * ‘(flags & 0x03) == 0x01’: call *note str(): 330. on `value' before formatting it. * ‘(flags & 0x03) == 0x02’: call *note repr(): 7cc. on `value' before formatting it. * ‘(flags & 0x03) == 0x03’: call *note ascii(): d4c. on `value' before formatting it. * ‘(flags & 0x04) == 0x04’: pop `fmt_spec' from the stack and use it, else use an empty `fmt_spec'. Formatting is performed using ‘PyObject_Format()’. The result is pushed on the stack. New in version 3.6. -- Opcode: HAVE_ARGUMENT This is not really an opcode. It identifies the dividing line between opcodes which don’t use their argument and those that do (‘< HAVE_ARGUMENT’ and ‘>= HAVE_ARGUMENT’, respectively). Changed in version 3.6: Now every instruction has an argument, but opcodes ‘< HAVE_ARGUMENT’ ignore it. Before, only opcodes ‘>= HAVE_ARGUMENT’ had an argument.  File: python.info, Node: Opcode collections, Prev: Python Bytecode Instructions, Up: dis — Disassembler for Python bytecode 5.32.12.4 Opcode collections ............................ These collections are provided for automatic introspection of bytecode instructions: -- Data: dis.opname Sequence of operation names, indexable using the bytecode. -- Data: dis.opmap Dictionary mapping operation names to bytecodes. -- Data: dis.cmp_op Sequence of all compare operation names. -- Data: dis.hasconst Sequence of bytecodes that access a constant. -- Data: dis.hasfree Sequence of bytecodes that access a free variable (note that ‘free’ in this context refers to names in the current scope that are referenced by inner scopes or names in outer scopes that are referenced from this scope. It does `not' include references to global or builtin scopes). -- Data: dis.hasname Sequence of bytecodes that access an attribute by name. -- Data: dis.hasjrel Sequence of bytecodes that have a relative jump target. -- Data: dis.hasjabs Sequence of bytecodes that have an absolute jump target. -- Data: dis.haslocal Sequence of bytecodes that access a local variable. -- Data: dis.hascompare Sequence of bytecodes of Boolean operations.  File: python.info, Node: pickletools — Tools for pickle developers, Prev: dis — Disassembler for Python bytecode, Up: Python Language Services 5.32.13 ‘pickletools’ — Tools for pickle developers --------------------------------------------------- `Source code:' Lib/pickletools.py(1) __________________________________________________________________ This module contains various constants relating to the intimate details of the *note pickle: ca. module, some lengthy comments about the implementation, and a few useful functions for analyzing pickled data. The contents of this module are useful for Python core developers who are working on the *note pickle: ca.; ordinary users of the *note pickle: ca. module probably won’t find the *note pickletools: cb. module relevant. * Menu: * Command line usage: Command line usage<2>. * Programmatic Interface: Programmatic Interface<2>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pickletools.py  File: python.info, Node: Command line usage<2>, Next: Programmatic Interface<2>, Up: pickletools — Tools for pickle developers 5.32.13.1 Command line usage ............................ New in version 3.2. When invoked from the command line, ‘python -m pickletools’ will disassemble the contents of one or more pickle files. Note that if you want to see the Python object stored in the pickle rather than the details of pickle format, you may want to use ‘-m pickle’ instead. However, when the pickle file that you want to examine comes from an untrusted source, ‘-m pickletools’ is a safer option because it does not execute pickle bytecode. For example, with a tuple ‘(1, 2)’ pickled in file ‘x.pickle’: $ python -m pickle x.pickle (1, 2) $ python -m pickletools x.pickle 0: \x80 PROTO 3 2: K BININT1 1 4: K BININT1 2 6: \x86 TUPLE2 7: q BINPUT 0 9: . STOP highest protocol among opcodes = 2 * Menu: * Command line options: Command line options<3>.  File: python.info, Node: Command line options<3>, Up: Command line usage<2> 5.32.13.2 Command line options .............................. -- Program Option: -a, --annotate Annotate each line with a short opcode description. -- Program Option: -o, --output=<file> Name of a file where the output should be written. -- Program Option: -l, --indentlevel=<num> The number of blanks by which to indent a new MARK level. -- Program Option: -m, --memo When multiple objects are disassembled, preserve memo between disassemblies. -- Program Option: -p, --preamble=<preamble> When more than one pickle file are specified, print given preamble before each disassembly.  File: python.info, Node: Programmatic Interface<2>, Prev: Command line usage<2>, Up: pickletools — Tools for pickle developers 5.32.13.3 Programmatic Interface ................................ -- Function: pickletools.dis (pickle, out=None, memo=None, indentlevel=4, annotate=0) Outputs a symbolic disassembly of the pickle to the file-like object `out', defaulting to ‘sys.stdout’. `pickle' can be a string or a file-like object. `memo' can be a Python dictionary that will be used as the pickle’s memo; it can be used to perform disassemblies across multiple pickles created by the same pickler. Successive levels, indicated by ‘MARK’ opcodes in the stream, are indented by `indentlevel' spaces. If a nonzero value is given to `annotate', each opcode in the output is annotated with a short description. The value of `annotate' is used as a hint for the column where annotation should start. New in version 3.2: The `annotate' argument. -- Function: pickletools.genops (pickle) Provides an *note iterator: 112e. over all of the opcodes in a pickle, returning a sequence of ‘(opcode, arg, pos)’ triples. `opcode' is an instance of an ‘OpcodeInfo’ class; `arg' is the decoded value, as a Python object, of the opcode’s argument; `pos' is the position at which this opcode is located. `pickle' can be a string or a file-like object. -- Function: pickletools.optimize (picklestring) Returns a new equivalent pickle string after eliminating unused ‘PUT’ opcodes. The optimized pickle is shorter, takes less transmission time, requires less storage space, and unpickles more efficiently.  File: python.info, Node: Miscellaneous Services, Next: MS Windows Specific Services, Prev: Python Language Services, Up: The Python Standard Library 5.33 Miscellaneous Services =========================== The modules described in this chapter provide miscellaneous services that are available in all Python versions. Here’s an overview: * Menu: * formatter — Generic output formatting::  File: python.info, Node: formatter — Generic output formatting, Up: Miscellaneous Services 5.33.1 ‘formatter’ — Generic output formatting ---------------------------------------------- Deprecated since version 3.4: Due to lack of usage, the formatter module has been deprecated. __________________________________________________________________ This module supports two interface definitions, each with multiple implementations: The `formatter' interface, and the `writer' interface which is required by the formatter interface. Formatter objects transform an abstract flow of formatting events into specific output events on writer objects. Formatters manage several stack structures to allow various properties of a writer object to be changed and restored; writers need not be able to handle relative changes nor any sort of “change back” operation. Specific writer properties which may be controlled via formatter objects are horizontal alignment, font, and left margin indentations. A mechanism is provided which supports providing arbitrary, non-exclusive style settings to a writer as well. Additional interfaces facilitate formatting events which are not reversible, such as paragraph separation. Writer objects encapsulate device interfaces. Abstract devices, such as file formats, are supported as well as physical devices. The provided implementations all work with abstract devices. The interface makes available mechanisms for setting the properties which formatter objects manage and inserting data into the output. * Menu: * The Formatter Interface:: * Formatter Implementations:: * The Writer Interface:: * Writer Implementations::  File: python.info, Node: The Formatter Interface, Next: Formatter Implementations, Up: formatter — Generic output formatting 5.33.1.1 The Formatter Interface ................................ Interfaces to create formatters are dependent on the specific formatter class being instantiated. The interfaces described below are the required interfaces which all formatters must support once initialized. One data element is defined at the module level: -- Data: formatter.AS_IS Value which can be used in the font specification passed to the ‘push_font()’ method described below, or as the new value to any other ‘push_property()’ method. Pushing the ‘AS_IS’ value allows the corresponding ‘pop_property()’ method to be called without having to track whether the property was changed. The following attributes are defined for formatter instance objects: -- Attribute: formatter.writer The writer instance with which the formatter interacts. -- Method: formatter.end_paragraph (blanklines) Close any open paragraphs and insert at least `blanklines' before the next paragraph. -- Method: formatter.add_line_break () Add a hard line break if one does not already exist. This does not break the logical paragraph. -- Method: formatter.add_hor_rule (*args, **kw) Insert a horizontal rule in the output. A hard break is inserted if there is data in the current paragraph, but the logical paragraph is not broken. The arguments and keywords are passed on to the writer’s ‘send_line_break()’ method. -- Method: formatter.add_flowing_data (data) Provide data which should be formatted with collapsed whitespace. Whitespace from preceding and successive calls to *note add_flowing_data(): 366d. is considered as well when the whitespace collapse is performed. The data which is passed to this method is expected to be word-wrapped by the output device. Note that any word-wrapping still must be performed by the writer object due to the need to rely on device and font information. -- Method: formatter.add_literal_data (data) Provide data which should be passed to the writer unchanged. Whitespace, including newline and tab characters, are considered legal in the value of `data'. -- Method: formatter.add_label_data (format, counter) Insert a label which should be placed to the left of the current left margin. This should be used for constructing bulleted or numbered lists. If the `format' value is a string, it is interpreted as a format specification for `counter', which should be an integer. The result of this formatting becomes the value of the label; if `format' is not a string it is used as the label value directly. The label value is passed as the only argument to the writer’s ‘send_label_data()’ method. Interpretation of non-string label values is dependent on the associated writer. Format specifications are strings which, in combination with a counter value, are used to compute label values. Each character in the format string is copied to the label value, with some characters recognized to indicate a transform on the counter value. Specifically, the character ‘'1'’ represents the counter value formatter as an Arabic number, the characters ‘'A'’ and ‘'a'’ represent alphabetic representations of the counter value in upper and lower case, respectively, and ‘'I'’ and ‘'i'’ represent the counter value in Roman numerals, in upper and lower case. Note that the alphabetic and roman transforms require that the counter value be greater than zero. -- Method: formatter.flush_softspace () Send any pending whitespace buffered from a previous call to *note add_flowing_data(): 366d. to the associated writer object. This should be called before any direct manipulation of the writer object. -- Method: formatter.push_alignment (align) Push a new alignment setting onto the alignment stack. This may be *note AS_IS: 3668. if no change is desired. If the alignment value is changed from the previous setting, the writer’s ‘new_alignment()’ method is called with the `align' value. -- Method: formatter.pop_alignment () Restore the previous alignment. -- Method: formatter.push_font ((size, italic, bold, teletype)) Change some or all font properties of the writer object. Properties which are not set to *note AS_IS: 3668. are set to the values passed in while others are maintained at their current settings. The writer’s ‘new_font()’ method is called with the fully resolved font specification. -- Method: formatter.pop_font () Restore the previous font. -- Method: formatter.push_margin (margin) Increase the number of left margin indentations by one, associating the logical tag `margin' with the new indentation. The initial margin level is ‘0’. Changed values of the logical tag must be true values; false values other than *note AS_IS: 3668. are not sufficient to change the margin. -- Method: formatter.pop_margin () Restore the previous margin. -- Method: formatter.push_style (*styles) Push any number of arbitrary style specifications. All styles are pushed onto the styles stack in order. A tuple representing the entire stack, including *note AS_IS: 3668. values, is passed to the writer’s ‘new_styles()’ method. -- Method: formatter.pop_style (n=1) Pop the last `n' style specifications passed to *note push_style(): 3677. A tuple representing the revised stack, including *note AS_IS: 3668. values, is passed to the writer’s ‘new_styles()’ method. -- Method: formatter.set_spacing (spacing) Set the spacing style for the writer. -- Method: formatter.assert_line_data (flag=1) Inform the formatter that data has been added to the current paragraph out-of-band. This should be used when the writer has been manipulated directly. The optional `flag' argument can be set to false if the writer manipulations produced a hard line break at the end of the output.  File: python.info, Node: Formatter Implementations, Next: The Writer Interface, Prev: The Formatter Interface, Up: formatter — Generic output formatting 5.33.1.2 Formatter Implementations .................................. Two implementations of formatter objects are provided by this module. Most applications may use one of these classes without modification or subclassing. -- Class: formatter.NullFormatter (writer=None) A formatter which does nothing. If `writer' is omitted, a *note NullWriter: 367e. instance is created. No methods of the writer are called by *note NullFormatter: 367d. instances. Implementations should inherit from this class if implementing a writer interface but don’t need to inherit any implementation. -- Class: formatter.AbstractFormatter (writer) The standard formatter. This implementation has demonstrated wide applicability to many writers, and may be used directly in most circumstances. It has been used to implement a full-featured World Wide Web browser.  File: python.info, Node: The Writer Interface, Next: Writer Implementations, Prev: Formatter Implementations, Up: formatter — Generic output formatting 5.33.1.3 The Writer Interface ............................. Interfaces to create writers are dependent on the specific writer class being instantiated. The interfaces described below are the required interfaces which all writers must support once initialized. Note that while most applications can use the *note AbstractFormatter: 367f. class as a formatter, the writer must typically be provided by the application. -- Method: writer.flush () Flush any buffered output or device control events. -- Method: writer.new_alignment (align) Set the alignment style. The `align' value can be any object, but by convention is a string or ‘None’, where ‘None’ indicates that the writer’s “preferred” alignment should be used. Conventional `align' values are ‘'left'’, ‘'center'’, ‘'right'’, and ‘'justify'’. -- Method: writer.new_font (font) Set the font style. The value of `font' will be ‘None’, indicating that the device’s default font should be used, or a tuple of the form ‘(size, italic, bold, teletype)’. Size will be a string indicating the size of font that should be used; specific strings and their interpretation must be defined by the application. The `italic', `bold', and `teletype' values are Boolean values specifying which of those font attributes should be used. -- Method: writer.new_margin (margin, level) Set the margin level to the integer `level' and the logical tag to `margin'. Interpretation of the logical tag is at the writer’s discretion; the only restriction on the value of the logical tag is that it not be a false value for non-zero values of `level'. -- Method: writer.new_spacing (spacing) Set the spacing style to `spacing'. -- Method: writer.new_styles (styles) Set additional styles. The `styles' value is a tuple of arbitrary values; the value *note AS_IS: 3668. should be ignored. The `styles' tuple may be interpreted either as a set or as a stack depending on the requirements of the application and writer implementation. -- Method: writer.send_line_break () Break the current line. -- Method: writer.send_paragraph (blankline) Produce a paragraph separation of at least `blankline' blank lines, or the equivalent. The `blankline' value will be an integer. Note that the implementation will receive a call to *note send_line_break(): 3688. before this call if a line break is needed; this method should not include ending the last line of the paragraph. It is only responsible for vertical spacing between paragraphs. -- Method: writer.send_hor_rule (*args, **kw) Display a horizontal rule on the output device. The arguments to this method are entirely application- and writer-specific, and should be interpreted with care. The method implementation may assume that a line break has already been issued via *note send_line_break(): 3688. -- Method: writer.send_flowing_data (data) Output character data which may be word-wrapped and re-flowed as needed. Within any sequence of calls to this method, the writer may assume that spans of multiple whitespace characters have been collapsed to single space characters. -- Method: writer.send_literal_data (data) Output character data which has already been formatted for display. Generally, this should be interpreted to mean that line breaks indicated by newline characters should be preserved and no new line breaks should be introduced. The data may contain embedded newline and tab characters, unlike data provided to the ‘send_formatted_data()’ interface. -- Method: writer.send_label_data (data) Set `data' to the left of the current left margin, if possible. The value of `data' is not restricted; treatment of non-string values is entirely application- and writer-dependent. This method will only be called at the beginning of a line.  File: python.info, Node: Writer Implementations, Prev: The Writer Interface, Up: formatter — Generic output formatting 5.33.1.4 Writer Implementations ............................... Three implementations of the writer object interface are provided as examples by this module. Most applications will need to derive new writer classes from the *note NullWriter: 367e. class. -- Class: formatter.NullWriter A writer which only provides the interface definition; no actions are taken on any methods. This should be the base class for all writers which do not need to inherit any implementation methods. -- Class: formatter.AbstractWriter A writer which can be used in debugging formatters, but not much else. Each method simply announces itself by printing its name and arguments on standard output. -- Class: formatter.DumbWriter (file=None, maxcol=72) Simple writer class which writes output on the *note file object: b42. passed in as `file' or, if `file' is omitted, on standard output. The output is simply word-wrapped to the number of columns specified by `maxcol'. This class is suitable for reflowing a sequence of paragraphs.  File: python.info, Node: MS Windows Specific Services, Next: Unix Specific Services, Prev: Miscellaneous Services, Up: The Python Standard Library 5.34 MS Windows Specific Services ================================= This chapter describes modules that are only available on MS Windows platforms. * Menu: * msilib — Read and write Microsoft Installer files:: * msvcrt — Useful routines from the MS VC++ runtime:: * winreg — Windows registry access:: * winsound — Sound-playing interface for Windows::  File: python.info, Node: msilib — Read and write Microsoft Installer files, Next: msvcrt — Useful routines from the MS VC++ runtime, Up: MS Windows Specific Services 5.34.1 ‘msilib’ — Read and write Microsoft Installer files ---------------------------------------------------------- `Source code:' Lib/msilib/__init__.py(1) __________________________________________________________________ The *note msilib: b5. supports the creation of Microsoft Installer (‘.msi’) files. Because these files often contain an embedded “cabinet” file (‘.cab’), it also exposes an API to create CAB files. Support for reading ‘.cab’ files is currently not implemented; read support for the ‘.msi’ database is possible. This package aims to provide complete access to all tables in an ‘.msi’ file, therefore, it is a fairly low-level API. Two primary applications of this package are the *note distutils: 39. command ‘bdist_msi’, and the creation of Python installer package itself (although that currently uses a different version of ‘msilib’). The package contents can be roughly split into four parts: low-level CAB routines, low-level MSI routines, higher-level MSI routines, and standard table structures. -- Function: msilib.FCICreate (cabname, files) Create a new CAB file named `cabname'. `files' must be a list of tuples, each containing the name of the file on disk, and the name of the file inside the CAB file. The files are added to the CAB file in the order they appear in the list. All files are added into a single CAB file, using the MSZIP compression algorithm. Callbacks to Python for the various steps of MSI creation are currently not exposed. -- Function: msilib.UuidCreate () Return the string representation of a new unique identifier. This wraps the Windows API functions ‘UuidCreate()’ and ‘UuidToString()’. -- Function: msilib.OpenDatabase (path, persist) Return a new database object by calling MsiOpenDatabase. `path' is the file name of the MSI file; `persist' can be one of the constants ‘MSIDBOPEN_CREATEDIRECT’, ‘MSIDBOPEN_CREATE’, ‘MSIDBOPEN_DIRECT’, ‘MSIDBOPEN_READONLY’, or ‘MSIDBOPEN_TRANSACT’, and may include the flag ‘MSIDBOPEN_PATCHFILE’. See the Microsoft documentation for the meaning of these flags; depending on the flags, an existing database is opened, or a new one created. -- Function: msilib.CreateRecord (count) Return a new record object by calling ‘MSICreateRecord()’. `count' is the number of fields of the record. -- Function: msilib.init_database (name, schema, ProductName, ProductCode, ProductVersion, Manufacturer) Create and return a new database `name', initialize it with `schema', and set the properties `ProductName', `ProductCode', `ProductVersion', and `Manufacturer'. `schema' must be a module object containing ‘tables’ and ‘_Validation_records’ attributes; typically, *note msilib.schema: 369b. should be used. The database will contain just the schema and the validation records when this function returns. -- Function: msilib.add_data (database, table, records) Add all `records' to the table named `table' in `database'. The `table' argument must be one of the predefined tables in the MSI schema, e.g. ‘'Feature'’, ‘'File'’, ‘'Component'’, ‘'Dialog'’, ‘'Control'’, etc. `records' should be a list of tuples, each one containing all fields of a record according to the schema of the table. For optional fields, ‘None’ can be passed. Field values can be ints, strings, or instances of the Binary class. -- Class: msilib.Binary (filename) Represents entries in the Binary table; inserting such an object using *note add_data(): 369c. reads the file named `filename' into the table. -- Function: msilib.add_tables (database, module) Add all table content from `module' to `database'. `module' must contain an attribute `tables' listing all tables for which content should be added, and one attribute per table that has the actual content. This is typically used to install the sequence tables. -- Function: msilib.add_stream (database, name, path) Add the file `path' into the ‘_Stream’ table of `database', with the stream name `name'. -- Function: msilib.gen_uuid () Return a new UUID, in the format that MSI typically requires (i.e. in curly braces, and with all hexdigits in upper-case). See also ........ FCICreate(2) UuidCreate(3) UuidToString(4) * Menu: * Database Objects:: * View Objects:: * Summary Information Objects:: * Record Objects:: * Errors:: * CAB Objects:: * Directory Objects:: * Features: Features<3>. * GUI classes:: * Precomputed tables:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/msilib/__init__.py (2) https://msdn.microsoft.com/en-us/library/bb432265.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa379205.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa379352.aspx  File: python.info, Node: Database Objects, Next: View Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.1 Database Objects ......................... -- Method: Database.OpenView (sql) Return a view object, by calling ‘MSIDatabaseOpenView()’. `sql' is the SQL statement to execute. -- Method: Database.Commit () Commit the changes pending in the current transaction, by calling ‘MSIDatabaseCommit()’. -- Method: Database.GetSummaryInformation (count) Return a new summary information object, by calling ‘MsiGetSummaryInformation()’. `count' is the maximum number of updated values. -- Method: Database.Close () Close the database object, through ‘MsiCloseHandle()’. New in version 3.7. See also ........ MSIDatabaseOpenView(1) MSIDatabaseCommit(2) MSIGetSummaryInformation(3) MsiCloseHandle(4) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370082.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370075.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370301.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370067.aspx  File: python.info, Node: View Objects, Next: Summary Information Objects, Prev: Database Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.2 View Objects ..................... -- Method: View.Execute (params) Execute the SQL query of the view, through ‘MSIViewExecute()’. If `params' is not ‘None’, it is a record describing actual values of the parameter tokens in the query. -- Method: View.GetColumnInfo (kind) Return a record describing the columns of the view, through calling ‘MsiViewGetColumnInfo()’. `kind' can be either ‘MSICOLINFO_NAMES’ or ‘MSICOLINFO_TYPES’. -- Method: View.Fetch () Return a result record of the query, through calling ‘MsiViewFetch()’. -- Method: View.Modify (kind, data) Modify the view, by calling ‘MsiViewModify()’. `kind' can be one of ‘MSIMODIFY_SEEK’, ‘MSIMODIFY_REFRESH’, ‘MSIMODIFY_INSERT’, ‘MSIMODIFY_UPDATE’, ‘MSIMODIFY_ASSIGN’, ‘MSIMODIFY_REPLACE’, ‘MSIMODIFY_MERGE’, ‘MSIMODIFY_DELETE’, ‘MSIMODIFY_INSERT_TEMPORARY’, ‘MSIMODIFY_VALIDATE’, ‘MSIMODIFY_VALIDATE_NEW’, ‘MSIMODIFY_VALIDATE_FIELD’, or ‘MSIMODIFY_VALIDATE_DELETE’. `data' must be a record describing the new data. -- Method: View.Close () Close the view, through ‘MsiViewClose()’. See also ........ MsiViewExecute(1) MSIViewGetColumnInfo(2) MsiViewFetch(3) MsiViewModify(4) MsiViewClose(5) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370513.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370516.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370514.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370519.aspx (5) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370510.aspx  File: python.info, Node: Summary Information Objects, Next: Record Objects, Prev: View Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.3 Summary Information Objects .................................... -- Method: SummaryInformation.GetProperty (field) Return a property of the summary, through ‘MsiSummaryInfoGetProperty()’. `field' is the name of the property, and can be one of the constants ‘PID_CODEPAGE’, ‘PID_TITLE’, ‘PID_SUBJECT’, ‘PID_AUTHOR’, ‘PID_KEYWORDS’, ‘PID_COMMENTS’, ‘PID_TEMPLATE’, ‘PID_LASTAUTHOR’, ‘PID_REVNUMBER’, ‘PID_LASTPRINTED’, ‘PID_CREATE_DTM’, ‘PID_LASTSAVE_DTM’, ‘PID_PAGECOUNT’, ‘PID_WORDCOUNT’, ‘PID_CHARCOUNT’, ‘PID_APPNAME’, or ‘PID_SECURITY’. -- Method: SummaryInformation.GetPropertyCount () Return the number of summary properties, through ‘MsiSummaryInfoGetPropertyCount()’. -- Method: SummaryInformation.SetProperty (field, value) Set a property through ‘MsiSummaryInfoSetProperty()’. `field' can have the same values as in *note GetProperty(): 36af, `value' is the new value of the property. Possible value types are integer and string. -- Method: SummaryInformation.Persist () Write the modified properties to the summary information stream, using ‘MsiSummaryInfoPersist()’. See also ........ MsiSummaryInfoGetProperty(1) MsiSummaryInfoGetPropertyCount(2) MsiSummaryInfoSetProperty(3) MsiSummaryInfoPersist(4) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370409.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370488.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370491.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370490.aspx  File: python.info, Node: Record Objects, Next: Errors, Prev: Summary Information Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.4 Record Objects ....................... -- Method: Record.GetFieldCount () Return the number of fields of the record, through ‘MsiRecordGetFieldCount()’. -- Method: Record.GetInteger (field) Return the value of `field' as an integer where possible. `field' must be an integer. -- Method: Record.GetString (field) Return the value of `field' as a string where possible. `field' must be an integer. -- Method: Record.SetString (field, value) Set `field' to `value' through ‘MsiRecordSetString()’. `field' must be an integer; `value' a string. -- Method: Record.SetStream (field, value) Set `field' to the contents of the file named `value', through ‘MsiRecordSetStream()’. `field' must be an integer; `value' a string. -- Method: Record.SetInteger (field, value) Set `field' to `value' through ‘MsiRecordSetInteger()’. Both `field' and `value' must be an integer. -- Method: Record.ClearData () Set all fields of the record to 0, through ‘MsiRecordClearData()’. See also ........ MsiRecordGetFieldCount(1) MsiRecordSetString(2) MsiRecordSetStream(3) MsiRecordSetInteger(4) MsiRecordClearData(5) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370366.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370373.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370372.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370371.aspx (5) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370364.aspx  File: python.info, Node: Errors, Next: CAB Objects, Prev: Record Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.5 Errors ............... All wrappers around MSI functions raise ‘MSIError’; the string inside the exception will contain more detail.  File: python.info, Node: CAB Objects, Next: Directory Objects, Prev: Errors, Up: msilib — Read and write Microsoft Installer files 5.34.1.6 CAB Objects .................... -- Class: msilib.CAB (name) The class *note CAB: 36c0. represents a CAB file. During MSI construction, files will be added simultaneously to the ‘Files’ table, and to a CAB file. Then, when all files have been added, the CAB file can be written, then added to the MSI file. `name' is the name of the CAB file in the MSI file. -- Method: append (full, file, logical) Add the file with the pathname `full' to the CAB file, under the name `logical'. If there is already a file named `logical', a new file name is created. Return the index of the file in the CAB file, and the new name of the file inside the CAB file. -- Method: commit (database) Generate a CAB file, add it as a stream to the MSI file, put it into the ‘Media’ table, and remove the generated file from the disk.  File: python.info, Node: Directory Objects, Next: Features<3>, Prev: CAB Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.7 Directory Objects .......................... -- Class: msilib.Directory (database, cab, basedir, physical, logical, default[, componentflags]) Create a new directory in the Directory table. There is a current component at each point in time for the directory, which is either explicitly created through *note start_component(): 36c6, or implicitly when files are added for the first time. Files are added into the current component, and into the cab file. To create a directory, a base directory object needs to be specified (can be ‘None’), the path to the physical directory, and a logical directory name. `default' specifies the DefaultDir slot in the directory table. `componentflags' specifies the default flags that new components get. -- Method: start_component (component=None, feature=None, flags=None, keyfile=None, uuid=None) Add an entry to the Component table, and make this component the current component for this directory. If no component name is given, the directory name is used. If no `feature' is given, the current feature is used. If no `flags' are given, the directory’s default flags are used. If no `keyfile' is given, the KeyPath is left null in the Component table. -- Method: add_file (file, src=None, version=None, language=None) Add a file to the current component of the directory, starting a new one if there is no current component. By default, the file name in the source and the file table will be identical. If the `src' file is specified, it is interpreted relative to the current directory. Optionally, a `version' and a `language' can be specified for the entry in the File table. -- Method: glob (pattern, exclude=None) Add a list of files to the current component as specified in the glob pattern. Individual files can be excluded in the `exclude' list. -- Method: remove_pyc () Remove ‘.pyc’ files on uninstall. See also ........ Directory Table(1) File Table(2) Component Table(3) FeatureComponents Table(4) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368295.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368596.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368007.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368579.aspx  File: python.info, Node: Features<3>, Next: GUI classes, Prev: Directory Objects, Up: msilib — Read and write Microsoft Installer files 5.34.1.8 Features ................. -- Class: msilib.Feature (db, id, title, desc, display, level=1, parent=None, directory=None, attributes=0) Add a new record to the ‘Feature’ table, using the values `id', `parent.id', `title', `desc', `display', `level', `directory', and `attributes'. The resulting feature object can be passed to the ‘start_component()’ method of *note Directory: 36c5. -- Method: set_current () Make this feature the current feature of *note msilib: b5. New components are automatically added to the default feature, unless a feature is explicitly specified. See also ........ Feature Table(1) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368585.aspx  File: python.info, Node: GUI classes, Next: Precomputed tables, Prev: Features<3>, Up: msilib — Read and write Microsoft Installer files 5.34.1.9 GUI classes .................... *note msilib: b5. provides several classes that wrap the GUI tables in an MSI database. However, no standard user interface is provided; use *note bdist_msi: 41. to create MSI files with a user-interface for installing Python packages. -- Class: msilib.Control (dlg, name) Base class of the dialog controls. `dlg' is the dialog object the control belongs to, and `name' is the control’s name. -- Method: event (event, argument, condition=1, ordering=None) Make an entry into the ‘ControlEvent’ table for this control. -- Method: mapping (event, attribute) Make an entry into the ‘EventMapping’ table for this control. -- Method: condition (action, condition) Make an entry into the ‘ControlCondition’ table for this control. -- Class: msilib.RadioButtonGroup (dlg, name, property) Create a radio button control named `name'. `property' is the installer property that gets set when a radio button is selected. -- Method: add (name, x, y, width, height, text, value=None) Add a radio button named `name' to the group, at the coordinates `x', `y', `width', `height', and with the label `text'. If `value' is ‘None’, it defaults to `name'. -- Class: msilib.Dialog (db, name, x, y, w, h, attr, title, first, default, cancel) Return a new *note Dialog: 36d6. object. An entry in the ‘Dialog’ table is made, with the specified coordinates, dialog attributes, title, name of the first, default, and cancel controls. -- Method: control (name, type, x, y, width, height, attributes, property, text, control_next, help) Return a new *note Control: 36d0. object. An entry in the ‘Control’ table is made with the specified parameters. This is a generic method; for specific types, specialized methods are provided. -- Method: text (name, x, y, width, height, attributes, text) Add and return a ‘Text’ control. -- Method: bitmap (name, x, y, width, height, text) Add and return a ‘Bitmap’ control. -- Method: line (name, x, y, width, height) Add and return a ‘Line’ control. -- Method: pushbutton (name, x, y, width, height, attributes, text, next_control) Add and return a ‘PushButton’ control. -- Method: radiogroup (name, x, y, width, height, attributes, property, text, next_control) Add and return a ‘RadioButtonGroup’ control. -- Method: checkbox (name, x, y, width, height, attributes, property, text, next_control) Add and return a ‘CheckBox’ control. See also ........ Dialog Table(1) Control Table(2) Control Types(3) ControlCondition Table(4) ControlEvent Table(5) EventMapping Table(6) RadioButton Table(7) ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368286.aspx (2) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368044.aspx (3) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368039.aspx (4) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368035.aspx (5) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368037.aspx (6) https://msdn.microsoft.com/en-us/library/windows/desktop/aa368559.aspx (7) https://msdn.microsoft.com/en-us/library/windows/desktop/aa370962.aspx  File: python.info, Node: Precomputed tables, Prev: GUI classes, Up: msilib — Read and write Microsoft Installer files 5.34.1.10 Precomputed tables ............................ *note msilib: b5. provides a few subpackages that contain only schema and table definitions. Currently, these definitions are based on MSI version 2.0. -- Data: msilib.schema This is the standard MSI schema for MSI 2.0, with the `tables' variable providing a list of table definitions, and `_Validation_records' providing the data for MSI validation. -- Data: msilib.sequence This module contains table contents for the standard sequence tables: `AdminExecuteSequence', `AdminUISequence', `AdvtExecuteSequence', `InstallExecuteSequence', and `InstallUISequence'. -- Data: msilib.text This module contains definitions for the UIText and ActionText tables, for the standard installer actions.  File: python.info, Node: msvcrt — Useful routines from the MS VC++ runtime, Next: winreg — Windows registry access, Prev: msilib — Read and write Microsoft Installer files, Up: MS Windows Specific Services 5.34.2 ‘msvcrt’ — Useful routines from the MS VC++ runtime ---------------------------------------------------------- __________________________________________________________________ These functions provide access to some useful capabilities on Windows platforms. Some higher-level modules use these functions to build the Windows implementations of their services. For example, the *note getpass: 88. module uses this in the implementation of the *note getpass(): 88. function. Further documentation on these functions can be found in the Platform API documentation. The module implements both the normal and wide char variants of the console I/O api. The normal API deals only with ASCII characters and is of limited use for internationalized applications. The wide char API should be used where ever possible. Changed in version 3.3: Operations in this module now raise *note OSError: 1d3. where *note IOError: 992. was raised. * Menu: * File Operations:: * Console I/O:: * Other Functions::  File: python.info, Node: File Operations, Next: Console I/O, Up: msvcrt — Useful routines from the MS VC++ runtime 5.34.2.1 File Operations ........................ -- Function: msvcrt.locking (fd, mode, nbytes) Lock part of a file based on file descriptor `fd' from the C runtime. Raises *note OSError: 1d3. on failure. The locked region of the file extends from the current file position for `nbytes' bytes, and may continue beyond the end of the file. `mode' must be one of the ‘LK_*’ constants listed below. Multiple regions in a file may be locked at the same time, but may not overlap. Adjacent regions are not merged; they must be unlocked individually. Raises an *note auditing event: fd1. ‘msvcrt.locking’ with arguments ‘fd’, ‘mode’, ‘nbytes’. -- Data: msvcrt.LK_LOCK -- Data: msvcrt.LK_RLCK Locks the specified bytes. If the bytes cannot be locked, the program immediately tries again after 1 second. If, after 10 attempts, the bytes cannot be locked, *note OSError: 1d3. is raised. -- Data: msvcrt.LK_NBLCK -- Data: msvcrt.LK_NBRLCK Locks the specified bytes. If the bytes cannot be locked, *note OSError: 1d3. is raised. -- Data: msvcrt.LK_UNLCK Unlocks the specified bytes, which must have been previously locked. -- Function: msvcrt.setmode (fd, flags) Set the line-end translation mode for the file descriptor `fd'. To set it to text mode, `flags' should be *note os.O_TEXT: 1bfc.; for binary, it should be *note os.O_BINARY: 1bed. -- Function: msvcrt.open_osfhandle (handle, flags) Create a C runtime file descriptor from the file handle `handle'. The `flags' parameter should be a bitwise OR of *note os.O_APPEND: 1bef, *note os.O_RDONLY: 1beb, and *note os.O_TEXT: 1bfc. The returned file descriptor may be used as a parameter to *note os.fdopen(): 10d2. to create a file object. Raises an *note auditing event: fd1. ‘msvcrt.open_osfhandle’ with arguments ‘handle’, ‘flags’. -- Function: msvcrt.get_osfhandle (fd) Return the file handle for the file descriptor `fd'. Raises *note OSError: 1d3. if `fd' is not recognized. Raises an *note auditing event: fd1. ‘msvcrt.get_osfhandle’ with argument ‘fd’.  File: python.info, Node: Console I/O, Next: Other Functions, Prev: File Operations, Up: msvcrt — Useful routines from the MS VC++ runtime 5.34.2.2 Console I/O .................... -- Function: msvcrt.kbhit () Return ‘True’ if a keypress is waiting to be read. -- Function: msvcrt.getch () Read a keypress and return the resulting character as a byte string. Nothing is echoed to the console. This call will block if a keypress is not already available, but will not wait for ‘Enter’ to be pressed. If the pressed key was a special function key, this will return ‘'\000'’ or ‘'\xe0'’; the next call will return the keycode. The ‘Control-C’ keypress cannot be read with this function. -- Function: msvcrt.getwch () Wide char variant of *note getch(): 36ef, returning a Unicode value. -- Function: msvcrt.getche () Similar to *note getch(): 36ef, but the keypress will be echoed if it represents a printable character. -- Function: msvcrt.getwche () Wide char variant of *note getche(): 36f1, returning a Unicode value. -- Function: msvcrt.putch (char) Print the byte string `char' to the console without buffering. -- Function: msvcrt.putwch (unicode_char) Wide char variant of *note putch(): 36f3, accepting a Unicode value. -- Function: msvcrt.ungetch (char) Cause the byte string `char' to be “pushed back” into the console buffer; it will be the next character read by *note getch(): 36ef. or *note getche(): 36f1. -- Function: msvcrt.ungetwch (unicode_char) Wide char variant of *note ungetch(): 36f5, accepting a Unicode value.  File: python.info, Node: Other Functions, Prev: Console I/O, Up: msvcrt — Useful routines from the MS VC++ runtime 5.34.2.3 Other Functions ........................ -- Function: msvcrt.heapmin () Force the ‘malloc()’ heap to clean itself up and return unused blocks to the operating system. On failure, this raises *note OSError: 1d3.  File: python.info, Node: winreg — Windows registry access, Next: winsound — Sound-playing interface for Windows, Prev: msvcrt — Useful routines from the MS VC++ runtime, Up: MS Windows Specific Services 5.34.3 ‘winreg’ — Windows registry access ----------------------------------------- __________________________________________________________________ These functions expose the Windows registry API to Python. Instead of using an integer as the registry handle, a *note handle object: 36fc. is used to ensure that the handles are closed correctly, even if the programmer neglects to explicitly close them. Changed in version 3.3: Several functions in this module used to raise a *note WindowsError: 994, which is now an alias of *note OSError: 1d3. * Menu: * Functions: Functions<11>. * Constants: Constants<10>. * Registry Handle Objects::  File: python.info, Node: Functions<11>, Next: Constants<10>, Up: winreg — Windows registry access 5.34.3.1 Functions .................. This module offers the following functions: -- Function: winreg.CloseKey (hkey) Closes a previously opened registry key. The `hkey' argument specifies a previously opened key. Note: If `hkey' is not closed using this method (or via *note hkey.Close(): 3701.), it is closed when the `hkey' object is destroyed by Python. -- Function: winreg.ConnectRegistry (computer_name, key) Establishes a connection to a predefined registry handle on another computer, and returns a *note handle object: 36fc. `computer_name' is the name of the remote computer, of the form ‘r"\\computername"’. If ‘None’, the local computer is used. `key' is the predefined handle to connect to. The return value is the handle of the opened key. If the function fails, an *note OSError: 1d3. exception is raised. Raises an *note auditing event: fd1. ‘winreg.ConnectRegistry’ with arguments ‘computer_name’, ‘key’. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.CreateKey (key, sub_key) Creates or opens the specified key, returning a *note handle object: 36fc. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that names the key this method opens or creates. If `key' is one of the predefined keys, `sub_key' may be ‘None’. In that case, the handle returned is the same key handle passed in to the function. If the key already exists, this function opens the existing key. The return value is the handle of the opened key. If the function fails, an *note OSError: 1d3. exception is raised. Raises an *note auditing event: fd1. ‘winreg.CreateKey’ with arguments ‘key’, ‘sub_key’, ‘access’. Raises an *note auditing event: fd1. ‘winreg.OpenKey/result’ with argument ‘key’. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.CreateKeyEx (key, sub_key, reserved=0, access=KEY_WRITE) Creates or opens the specified key, returning a *note handle object: 36fc. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that names the key this method opens or creates. `reserved' is a reserved integer, and must be zero. The default is zero. `access' is an integer that specifies an access mask that describes the desired security access for the key. Default is *note KEY_WRITE: 3703. See *note Access Rights: 3704. for other allowed values. If `key' is one of the predefined keys, `sub_key' may be ‘None’. In that case, the handle returned is the same key handle passed in to the function. If the key already exists, this function opens the existing key. The return value is the handle of the opened key. If the function fails, an *note OSError: 1d3. exception is raised. Raises an *note auditing event: fd1. ‘winreg.CreateKey’ with arguments ‘key’, ‘sub_key’, ‘access’. Raises an *note auditing event: fd1. ‘winreg.OpenKey/result’ with argument ‘key’. New in version 3.2. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.DeleteKey (key, sub_key) Deletes the specified key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that must be a subkey of the key identified by the `key' parameter. This value must not be ‘None’, and the key may not have subkeys. `This method can not delete keys with subkeys.' If the method succeeds, the entire key, including all of its values, is removed. If the method fails, an *note OSError: 1d3. exception is raised. Raises an *note auditing event: fd1. ‘winreg.DeleteKey’ with arguments ‘key’, ‘sub_key’, ‘access’. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.DeleteKeyEx (key, sub_key, access=KEY_WOW64_64KEY, reserved=0) Deletes the specified key. Note: The *note DeleteKeyEx(): 3201. function is implemented with the RegDeleteKeyEx Windows API function, which is specific to 64-bit versions of Windows. See the RegDeleteKeyEx documentation(1). `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that must be a subkey of the key identified by the `key' parameter. This value must not be ‘None’, and the key may not have subkeys. `reserved' is a reserved integer, and must be zero. The default is zero. `access' is an integer that specifies an access mask that describes the desired security access for the key. Default is *note KEY_WOW64_64KEY: 3705. See *note Access Rights: 3704. for other allowed values. `This method can not delete keys with subkeys.' If the method succeeds, the entire key, including all of its values, is removed. If the method fails, an *note OSError: 1d3. exception is raised. On unsupported Windows versions, *note NotImplementedError: 60e. is raised. Raises an *note auditing event: fd1. ‘winreg.DeleteKey’ with arguments ‘key’, ‘sub_key’, ‘access’. New in version 3.2. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.DeleteValue (key, value) Removes a named value from a registry key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `value' is a string that identifies the value to remove. Raises an *note auditing event: fd1. ‘winreg.DeleteValue’ with arguments ‘key’, ‘value’. -- Function: winreg.EnumKey (key, index) Enumerates subkeys of an open registry key, returning a string. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `index' is an integer that identifies the index of the key to retrieve. The function retrieves the name of one subkey each time it is called. It is typically called repeatedly until an *note OSError: 1d3. exception is raised, indicating, no more values are available. Raises an *note auditing event: fd1. ‘winreg.EnumKey’ with arguments ‘key’, ‘index’. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.EnumValue (key, index) Enumerates values of an open registry key, returning a tuple. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `index' is an integer that identifies the index of the value to retrieve. The function retrieves the name of one subkey each time it is called. It is typically called repeatedly, until an *note OSError: 1d3. exception is raised, indicating no more values. The result is a tuple of 3 items: Index Meaning ------------------------------------------------------------- ‘0’ A string that identifies the value name ‘1’ An object that holds the value data, and whose type depends on the underlying registry type ‘2’ An integer that identifies the type of the value data (see table in docs for *note SetValueEx(): 3211.) Raises an *note auditing event: fd1. ‘winreg.EnumValue’ with arguments ‘key’, ‘index’. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.ExpandEnvironmentStrings (str) Expands environment variable placeholders ‘%NAME%’ in strings like *note REG_EXPAND_SZ: 3706.: >>> ExpandEnvironmentStrings('%windir%') 'C:\\Windows' Raises an *note auditing event: fd1. ‘winreg.ExpandEnvironmentStrings’ with argument ‘str’. -- Function: winreg.FlushKey (key) Writes all the attributes of a key to the registry. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. It is not necessary to call *note FlushKey(): 3707. to change a key. Registry changes are flushed to disk by the registry using its lazy flusher. Registry changes are also flushed to disk at system shutdown. Unlike *note CloseKey(): 3700, the *note FlushKey(): 3707. method returns only when all the data has been written to the registry. An application should only call *note FlushKey(): 3707. if it requires absolute certainty that registry changes are on disk. Note: If you don’t know whether a *note FlushKey(): 3707. call is required, it probably isn’t. -- Function: winreg.LoadKey (key, sub_key, file_name) Creates a subkey under the specified key and stores registration information from a specified file into that subkey. `key' is a handle returned by *note ConnectRegistry(): 31fd. or one of the constants *note HKEY_USERS: 3708. or *note HKEY_LOCAL_MACHINE: 3709. `sub_key' is a string that identifies the subkey to load. `file_name' is the name of the file to load registry data from. This file must have been created with the *note SaveKey(): 320f. function. Under the file allocation table (FAT) file system, the filename may not have an extension. A call to *note LoadKey(): 3208. fails if the calling process does not have the ‘SE_RESTORE_PRIVILEGE’ privilege. Note that privileges are different from permissions – see the RegLoadKey documentation(2) for more details. If `key' is a handle returned by *note ConnectRegistry(): 31fd, then the path specified in `file_name' is relative to the remote computer. Raises an *note auditing event: fd1. ‘winreg.LoadKey’ with arguments ‘key’, ‘sub_key’, ‘file_name’. -- Function: winreg.OpenKey (key, sub_key, reserved=0, access=KEY_READ) -- Function: winreg.OpenKeyEx (key, sub_key, reserved=0, access=KEY_READ) Opens the specified key, returning a *note handle object: 36fc. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that identifies the sub_key to open. `reserved' is a reserved integer, and must be zero. The default is zero. `access' is an integer that specifies an access mask that describes the desired security access for the key. Default is *note KEY_READ: 370b. See *note Access Rights: 3704. for other allowed values. The result is a new handle to the specified key. If the function fails, *note OSError: 1d3. is raised. Raises an *note auditing event: fd1. ‘winreg.OpenKey’ with arguments ‘key’, ‘sub_key’, ‘access’. Raises an *note auditing event: fd1. ‘winreg.OpenKey/result’ with argument ‘key’. Changed in version 3.2: Allow the use of named arguments. Changed in version 3.3: See *note above: 36fd. -- Function: winreg.QueryInfoKey (key) Returns information about a key, as a tuple. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. The result is a tuple of 3 items: Index Meaning -------------------------------------------------------------- ‘0’ An integer giving the number of sub keys this key has. ‘1’ An integer giving the number of values this key has. ‘2’ An integer giving when the key was last modified (if available) as 100’s of nanoseconds since Jan 1, 1601. Raises an *note auditing event: fd1. ‘winreg.QueryInfoKey’ with argument ‘key’. -- Function: winreg.QueryValue (key, sub_key) Retrieves the unnamed value for a key, as a string. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that holds the name of the subkey with which the value is associated. If this parameter is ‘None’ or empty, the function retrieves the value set by the *note SetValue(): 3210. method for the key identified by `key'. Values in the registry have name, type, and data components. This method retrieves the data for a key’s first value that has a ‘NULL’ name. But the underlying API call doesn’t return the type, so always use *note QueryValueEx(): 320e. if possible. Raises an *note auditing event: fd1. ‘winreg.QueryValue’ with arguments ‘key’, ‘sub_key’, ‘value_name’. -- Function: winreg.QueryValueEx (key, value_name) Retrieves the type and data for a specified value name associated with an open registry key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `value_name' is a string indicating the value to query. The result is a tuple of 2 items: Index Meaning ---------------------------------------------------------- ‘0’ The value of the registry item. ‘1’ An integer giving the registry type for this value (see table in docs for *note SetValueEx(): 3211.) Raises an *note auditing event: fd1. ‘winreg.QueryValue’ with arguments ‘key’, ‘sub_key’, ‘value_name’. -- Function: winreg.SaveKey (key, file_name) Saves the specified key, and all its subkeys to the specified file. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `file_name' is the name of the file to save registry data to. This file cannot already exist. If this filename includes an extension, it cannot be used on file allocation table (FAT) file systems by the *note LoadKey(): 3208. method. If `key' represents a key on a remote computer, the path described by `file_name' is relative to the remote computer. The caller of this method must possess the ‘SeBackupPrivilege’ security privilege. Note that privileges are different than permissions – see the Conflicts Between User Rights and Permissions documentation(3) for more details. This function passes ‘NULL’ for `security_attributes' to the API. Raises an *note auditing event: fd1. ‘winreg.SaveKey’ with arguments ‘key’, ‘file_name’. -- Function: winreg.SetValue (key, sub_key, type, value) Associates a value with a specified key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `sub_key' is a string that names the subkey with which the value is associated. `type' is an integer that specifies the type of the data. Currently this must be *note REG_SZ: 370c, meaning only strings are supported. Use the *note SetValueEx(): 3211. function for support for other data types. `value' is a string that specifies the new value. If the key specified by the `sub_key' parameter does not exist, the SetValue function creates it. Value lengths are limited by available memory. Long values (more than 2048 bytes) should be stored as files with the filenames stored in the configuration registry. This helps the registry perform efficiently. The key identified by the `key' parameter must have been opened with *note KEY_SET_VALUE: 370d. access. Raises an *note auditing event: fd1. ‘winreg.SetValue’ with arguments ‘key’, ‘sub_key’, ‘type’, ‘value’. -- Function: winreg.SetValueEx (key, value_name, reserved, type, value) Stores data in the value field of an open registry key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. `value_name' is a string that names the subkey with which the value is associated. `reserved' can be anything – zero is always passed to the API. `type' is an integer that specifies the type of the data. See *note Value Types: 370e. for the available types. `value' is a string that specifies the new value. This method can also set additional value and type information for the specified key. The key identified by the key parameter must have been opened with *note KEY_SET_VALUE: 370d. access. To open the key, use the *note CreateKey(): 31fe. or *note OpenKey(): 3209. methods. Value lengths are limited by available memory. Long values (more than 2048 bytes) should be stored as files with the filenames stored in the configuration registry. This helps the registry perform efficiently. Raises an *note auditing event: fd1. ‘winreg.SetValue’ with arguments ‘key’, ‘sub_key’, ‘type’, ‘value’. -- Function: winreg.DisableReflectionKey (key) Disables registry reflection for 32-bit processes running on a 64-bit operating system. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. Will generally raise *note NotImplementedError: 60e. if executed on a 32-bit operating system. If the key is not on the reflection list, the function succeeds but has no effect. Disabling reflection for a key does not affect reflection of any subkeys. Raises an *note auditing event: fd1. ‘winreg.DisableReflectionKey’ with argument ‘key’. -- Function: winreg.EnableReflectionKey (key) Restores registry reflection for the specified disabled key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. Will generally raise *note NotImplementedError: 60e. if executed on a 32-bit operating system. Restoring reflection for a key does not affect reflection of any subkeys. Raises an *note auditing event: fd1. ‘winreg.EnableReflectionKey’ with argument ‘key’. -- Function: winreg.QueryReflectionKey (key) Determines the reflection state for the specified key. `key' is an already open key, or one of the predefined *note HKEY_* constants: 3702. Returns ‘True’ if reflection is disabled. Will generally raise *note NotImplementedError: 60e. if executed on a 32-bit operating system. Raises an *note auditing event: fd1. ‘winreg.QueryReflectionKey’ with argument ‘key’. ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/ms724847%28VS.85%29.aspx (2) https://msdn.microsoft.com/en-us/library/ms724889%28v=VS.85%29.aspx (3) https://msdn.microsoft.com/en-us/library/ms724878%28v=VS.85%29.aspx  File: python.info, Node: Constants<10>, Next: Registry Handle Objects, Prev: Functions<11>, Up: winreg — Windows registry access 5.34.3.2 Constants .................. The following constants are defined for use in many ‘_winreg’ functions. * Menu: * HKEY_* Constants:: * Access Rights:: * Value Types::  File: python.info, Node: HKEY_* Constants, Next: Access Rights, Up: Constants<10> 5.34.3.3 HKEY_* Constants ......................... -- Data: winreg.HKEY_CLASSES_ROOT Registry entries subordinate to this key define types (or classes) of documents and the properties associated with those types. Shell and COM applications use the information stored under this key. -- Data: winreg.HKEY_CURRENT_USER Registry entries subordinate to this key define the preferences of the current user. These preferences include the settings of environment variables, data about program groups, colors, printers, network connections, and application preferences. -- Data: winreg.HKEY_LOCAL_MACHINE Registry entries subordinate to this key define the physical state of the computer, including data about the bus type, system memory, and installed hardware and software. -- Data: winreg.HKEY_USERS Registry entries subordinate to this key define the default user configuration for new users on the local computer and the user configuration for the current user. -- Data: winreg.HKEY_PERFORMANCE_DATA Registry entries subordinate to this key allow you to access performance data. The data is not actually stored in the registry; the registry functions cause the system to collect the data from its source. -- Data: winreg.HKEY_CURRENT_CONFIG Contains information about the current hardware profile of the local computer system. -- Data: winreg.HKEY_DYN_DATA This key is not used in versions of Windows after 98.  File: python.info, Node: Access Rights, Next: Value Types, Prev: HKEY_* Constants, Up: Constants<10> 5.34.3.4 Access Rights ...................... For more information, see Registry Key Security and Access(1). -- Data: winreg.KEY_ALL_ACCESS Combines the STANDARD_RIGHTS_REQUIRED, *note KEY_QUERY_VALUE: 3719, *note KEY_SET_VALUE: 370d, *note KEY_CREATE_SUB_KEY: 371a, *note KEY_ENUMERATE_SUB_KEYS: 371b, *note KEY_NOTIFY: 371c, and *note KEY_CREATE_LINK: 371d. access rights. -- Data: winreg.KEY_WRITE Combines the STANDARD_RIGHTS_WRITE, *note KEY_SET_VALUE: 370d, and *note KEY_CREATE_SUB_KEY: 371a. access rights. -- Data: winreg.KEY_READ Combines the STANDARD_RIGHTS_READ, *note KEY_QUERY_VALUE: 3719, *note KEY_ENUMERATE_SUB_KEYS: 371b, and *note KEY_NOTIFY: 371c. values. -- Data: winreg.KEY_EXECUTE Equivalent to *note KEY_READ: 370b. -- Data: winreg.KEY_QUERY_VALUE Required to query the values of a registry key. -- Data: winreg.KEY_SET_VALUE Required to create, delete, or set a registry value. -- Data: winreg.KEY_CREATE_SUB_KEY Required to create a subkey of a registry key. -- Data: winreg.KEY_ENUMERATE_SUB_KEYS Required to enumerate the subkeys of a registry key. -- Data: winreg.KEY_NOTIFY Required to request change notifications for a registry key or for subkeys of a registry key. -- Data: winreg.KEY_CREATE_LINK Reserved for system use. * Menu: * 64-bit Specific:: ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/ms724878%28v=VS.85%29.aspx  File: python.info, Node: 64-bit Specific, Up: Access Rights 5.34.3.5 64-bit Specific ........................ For more information, see Accessing an Alternate Registry View(1). -- Data: winreg.KEY_WOW64_64KEY Indicates that an application on 64-bit Windows should operate on the 64-bit registry view. -- Data: winreg.KEY_WOW64_32KEY Indicates that an application on 64-bit Windows should operate on the 32-bit registry view. ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/aa384129(v=VS.85).aspx  File: python.info, Node: Value Types, Prev: Access Rights, Up: Constants<10> 5.34.3.6 Value Types .................... For more information, see Registry Value Types(1). -- Data: winreg.REG_BINARY Binary data in any form. -- Data: winreg.REG_DWORD 32-bit number. -- Data: winreg.REG_DWORD_LITTLE_ENDIAN A 32-bit number in little-endian format. Equivalent to *note REG_DWORD: 3724. -- Data: winreg.REG_DWORD_BIG_ENDIAN A 32-bit number in big-endian format. -- Data: winreg.REG_EXPAND_SZ Null-terminated string containing references to environment variables (‘%PATH%’). -- Data: winreg.REG_LINK A Unicode symbolic link. -- Data: winreg.REG_MULTI_SZ A sequence of null-terminated strings, terminated by two null characters. (Python handles this termination automatically.) -- Data: winreg.REG_NONE No defined value type. -- Data: winreg.REG_QWORD A 64-bit number. New in version 3.6. -- Data: winreg.REG_QWORD_LITTLE_ENDIAN A 64-bit number in little-endian format. Equivalent to *note REG_QWORD: 5b2. New in version 3.6. -- Data: winreg.REG_RESOURCE_LIST A device-driver resource list. -- Data: winreg.REG_FULL_RESOURCE_DESCRIPTOR A hardware setting. -- Data: winreg.REG_RESOURCE_REQUIREMENTS_LIST A hardware resource list. -- Data: winreg.REG_SZ A null-terminated string. ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/ms724884%28v=VS.85%29.aspx  File: python.info, Node: Registry Handle Objects, Prev: Constants<10>, Up: winreg — Windows registry access 5.34.3.7 Registry Handle Objects ................................ This object wraps a Windows HKEY object, automatically closing it when the object is destroyed. To guarantee cleanup, you can call either the *note Close(): 3701. method on the object, or the *note CloseKey(): 3700. function. All registry functions in this module return one of these objects. All registry functions in this module which accept a handle object also accept an integer, however, use of the handle object is encouraged. Handle objects provide semantics for *note __bool__(): c68. – thus if handle: print("Yes") will print ‘Yes’ if the handle is currently valid (has not been closed or detached). The object also support comparison semantics, so handle objects will compare true if they both reference the same underlying Windows handle value. Handle objects can be converted to an integer (e.g., using the built-in *note int(): 184. function), in which case the underlying Windows handle value is returned. You can also use the *note Detach(): 320a. method to return the integer handle, and also disconnect the Windows handle from the handle object. -- Method: PyHKEY.Close () Closes the underlying Windows handle. If the handle is already closed, no error is raised. -- Method: PyHKEY.Detach () Detaches the Windows handle from the handle object. The result is an integer that holds the value of the handle before it is detached. If the handle is already detached or closed, this will return zero. After calling this function, the handle is effectively invalidated, but the handle is not closed. You would call this function when you need the underlying Win32 handle to exist beyond the lifetime of the handle object. Raises an *note auditing event: fd1. ‘winreg.PyHKEY.Detach’ with argument ‘key’. -- Method: PyHKEY.__enter__ () -- Method: PyHKEY.__exit__ (*exc_info) The HKEY object implements *note __enter__(): c95. and *note __exit__(): c96. and thus supports the context protocol for the *note with: 6e9. statement: with OpenKey(HKEY_LOCAL_MACHINE, "foo") as key: ... # work with key will automatically close `key' when control leaves the *note with: 6e9. block.  File: python.info, Node: winsound — Sound-playing interface for Windows, Prev: winreg — Windows registry access, Up: MS Windows Specific Services 5.34.4 ‘winsound’ — Sound-playing interface for Windows ------------------------------------------------------- __________________________________________________________________ The *note winsound: 12b. module provides access to the basic sound-playing machinery provided by Windows platforms. It includes functions and several constants. -- Function: winsound.Beep (frequency, duration) Beep the PC’s speaker. The `frequency' parameter specifies frequency, in hertz, of the sound, and must be in the range 37 through 32,767. The `duration' parameter specifies the number of milliseconds the sound should last. If the system is not able to beep the speaker, *note RuntimeError: 2ba. is raised. -- Function: winsound.PlaySound (sound, flags) Call the underlying ‘PlaySound()’ function from the Platform API. The `sound' parameter may be a filename, a system sound alias, audio data as a *note bytes-like object: 5e8, or ‘None’. Its interpretation depends on the value of `flags', which can be a bitwise ORed combination of the constants described below. If the `sound' parameter is ‘None’, any currently playing waveform sound is stopped. If the system indicates an error, *note RuntimeError: 2ba. is raised. -- Function: winsound.MessageBeep (type=MB_OK) Call the underlying ‘MessageBeep()’ function from the Platform API. This plays a sound as specified in the registry. The `type' argument specifies which sound to play; possible values are ‘-1’, ‘MB_ICONASTERISK’, ‘MB_ICONEXCLAMATION’, ‘MB_ICONHAND’, ‘MB_ICONQUESTION’, and ‘MB_OK’, all described below. The value ‘-1’ produces a “simple beep”; this is the final fallback if a sound cannot be played otherwise. If the system indicates an error, *note RuntimeError: 2ba. is raised. -- Data: winsound.SND_FILENAME The `sound' parameter is the name of a WAV file. Do not use with *note SND_ALIAS: 3734. -- Data: winsound.SND_ALIAS The `sound' parameter is a sound association name from the registry. If the registry contains no such name, play the system default sound unless *note SND_NODEFAULT: 3735. is also specified. If no default sound is registered, raise *note RuntimeError: 2ba. Do not use with *note SND_FILENAME: 3733. All Win32 systems support at least the following; most systems support many more: *note PlaySound(): 5b6. Corresponding Control Panel Sound name `name' ---------------------------------------------------------------------------- ‘'SystemAsterisk'’ Asterisk ‘'SystemExclamation'’ Exclamation ‘'SystemExit'’ Exit Windows ‘'SystemHand'’ Critical Stop ‘'SystemQuestion'’ Question For example: import winsound # Play Windows exit sound. winsound.PlaySound("SystemExit", winsound.SND_ALIAS) # Probably play Windows default sound, if any is registered (because # "*" probably isn't the registered name of any sound). winsound.PlaySound("*", winsound.SND_ALIAS) -- Data: winsound.SND_LOOP Play the sound repeatedly. The *note SND_ASYNC: 3737. flag must also be used to avoid blocking. Cannot be used with *note SND_MEMORY: 3738. -- Data: winsound.SND_MEMORY The `sound' parameter to *note PlaySound(): 5b6. is a memory image of a WAV file, as a *note bytes-like object: 5e8. Note: This module does not support playing from a memory image asynchronously, so a combination of this flag and *note SND_ASYNC: 3737. will raise *note RuntimeError: 2ba. -- Data: winsound.SND_PURGE Stop playing all instances of the specified sound. Note: This flag is not supported on modern Windows platforms. -- Data: winsound.SND_ASYNC Return immediately, allowing sounds to play asynchronously. -- Data: winsound.SND_NODEFAULT If the specified sound cannot be found, do not play the system default sound. -- Data: winsound.SND_NOSTOP Do not interrupt sounds currently playing. -- Data: winsound.SND_NOWAIT Return immediately if the sound driver is busy. Note: This flag is not supported on modern Windows platforms. -- Data: winsound.MB_ICONASTERISK Play the ‘SystemDefault’ sound. -- Data: winsound.MB_ICONEXCLAMATION Play the ‘SystemExclamation’ sound. -- Data: winsound.MB_ICONHAND Play the ‘SystemHand’ sound. -- Data: winsound.MB_ICONQUESTION Play the ‘SystemQuestion’ sound. -- Data: winsound.MB_OK Play the ‘SystemDefault’ sound.  File: python.info, Node: Unix Specific Services, Next: Superseded Modules, Prev: MS Windows Specific Services, Up: The Python Standard Library 5.35 Unix Specific Services =========================== The modules described in this chapter provide interfaces to features that are unique to the Unix operating system, or in some cases to some or many variants of it. Here’s an overview: * Menu: * posix — The most common POSIX system calls:: * pwd — The password database:: * spwd — The shadow password database:: * grp — The group database:: * crypt — Function to check Unix passwords:: * termios — POSIX style tty control:: * tty — Terminal control functions:: * pty — Pseudo-terminal utilities:: * fcntl — The fcntl and ioctl system calls:: * pipes — Interface to shell pipelines:: * resource — Resource usage information:: * nis — Interface to Sun’s NIS (Yellow Pages): nis — Interface to Sun’s NIS Yellow Pages. * syslog — Unix syslog library routines::  File: python.info, Node: posix — The most common POSIX system calls, Next: pwd — The password database, Up: Unix Specific Services 5.35.1 ‘posix’ — The most common POSIX system calls --------------------------------------------------- __________________________________________________________________ This module provides access to operating system functionality that is standardized by the C Standard and the POSIX standard (a thinly disguised Unix interface). `Do not import this module directly.' Instead, import the module *note os: c4, which provides a `portable' version of this interface. On Unix, the *note os: c4. module provides a superset of the *note posix: d1. interface. On non-Unix operating systems the *note posix: d1. module is not available, but a subset is always available through the *note os: c4. interface. Once *note os: c4. is imported, there is `no' performance penalty in using it instead of *note posix: d1. In addition, *note os: c4. provides some additional functionality, such as automatically calling *note putenv(): 1bb6. when an entry in ‘os.environ’ is changed. Errors are reported as exceptions; the usual exceptions are given for type errors, while errors reported by the system calls raise *note OSError: 1d3. * Menu: * Large File Support:: * Notable Module Contents::  File: python.info, Node: Large File Support, Next: Notable Module Contents, Up: posix — The most common POSIX system calls 5.35.1.1 Large File Support ........................... Several operating systems (including AIX, HP-UX, Irix and Solaris) provide support for files that are larger than 2 GiB from a C programming model where ‘int’ and ‘long’ are 32-bit values. This is typically accomplished by defining the relevant size and offset types as 64-bit values. Such files are sometimes referred to as `large files'. Large file support is enabled in Python when the size of an ‘off_t’ is larger than a ‘long’ and the ‘long long’ is at least as large as an ‘off_t’. It may be necessary to configure and compile Python with certain compiler flags to enable this mode. For example, it is enabled by default with recent versions of Irix, but with Solaris 2.6 and 2.7 you need to do something like: CFLAGS="`getconf LFS_CFLAGS`" OPT="-g -O2 $CFLAGS" \ ./configure On large-file-capable Linux systems, this might work: CFLAGS='-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64' OPT="-g -O2 $CFLAGS" \ ./configure  File: python.info, Node: Notable Module Contents, Prev: Large File Support, Up: posix — The most common POSIX system calls 5.35.1.2 Notable Module Contents ................................ In addition to many functions described in the *note os: c4. module documentation, *note posix: d1. defines the following data item: -- Data: posix.environ A dictionary representing the string environment at the time the interpreter was started. Keys and values are bytes on Unix and str on Windows. For example, ‘environ[b'HOME']’ (‘environ['HOME']’ on Windows) is the pathname of your home directory, equivalent to ‘getenv("HOME")’ in C. Modifying this dictionary does not affect the string environment passed on by *note execv(): 1bc9, *note popen(): 2a9. or *note system(): dc1.; if you need to change the environment, pass ‘environ’ to *note execve(): a40. or add variable assignments and export statements to the command string for *note system(): dc1. or *note popen(): 2a9. Changed in version 3.2: On Unix, keys and values are bytes. Note: The *note os: c4. module provides an alternate implementation of ‘environ’ which updates the environment on modification. Note also that updating *note os.environ: b37. will render this dictionary obsolete. Use of the *note os: c4. module version of this is recommended over direct access to the *note posix: d1. module.  File: python.info, Node: pwd — The password database, Next: spwd — The shadow password database, Prev: posix — The most common POSIX system calls, Up: Unix Specific Services 5.35.2 ‘pwd’ — The password database ------------------------------------ __________________________________________________________________ This module provides access to the Unix user account and password database. It is available on all Unix versions. Password database entries are reported as a tuple-like object, whose attributes correspond to the members of the ‘passwd’ structure (Attribute field below, see ‘<pwd.h>’): Index Attribute Meaning ------------------------------------------------------------------ 0 ‘pw_name’ Login name 1 ‘pw_passwd’ Optional encrypted password 2 ‘pw_uid’ Numerical user ID 3 ‘pw_gid’ Numerical group ID 4 ‘pw_gecos’ User name or comment field 5 ‘pw_dir’ User home directory 6 ‘pw_shell’ User command interpreter The uid and gid items are integers, all others are strings. *note KeyError: 2c7. is raised if the entry asked for cannot be found. Note: In traditional Unix the field ‘pw_passwd’ usually contains a password encrypted with a DES derived algorithm (see module *note crypt: 29.). However most modern unices use a so-called `shadow password' system. On those unices the `pw_passwd' field only contains an asterisk (‘'*'’) or the letter ‘'x'’ where the encrypted password is stored in a file ‘/etc/shadow’ which is not world readable. Whether the `pw_passwd' field contains anything useful is system-dependent. If available, the *note spwd: f1. module should be used where access to the encrypted password is required. It defines the following items: -- Function: pwd.getpwuid (uid) Return the password database entry for the given numeric user ID. -- Function: pwd.getpwnam (name) Return the password database entry for the given user name. -- Function: pwd.getpwall () Return a list of all available password database entries, in arbitrary order. See also ........ Module *note grp: 8b. An interface to the group database, similar to this. Module *note spwd: f1. An interface to the shadow password database, similar to this.  File: python.info, Node: spwd — The shadow password database, Next: grp — The group database, Prev: pwd — The password database, Up: Unix Specific Services 5.35.3 ‘spwd’ — The shadow password database -------------------------------------------- __________________________________________________________________ This module provides access to the Unix shadow password database. It is available on various Unix versions. You must have enough privileges to access the shadow password database (this usually means you have to be root). Shadow password database entries are reported as a tuple-like object, whose attributes correspond to the members of the ‘spwd’ structure (Attribute field below, see ‘<shadow.h>’): Index Attribute Meaning ---------------------------------------------------------------------- 0 ‘sp_namp’ Login name 1 ‘sp_pwdp’ Encrypted password 2 ‘sp_lstchg’ Date of last change 3 ‘sp_min’ Minimal number of days between changes 4 ‘sp_max’ Maximum number of days between changes 5 ‘sp_warn’ Number of days before password expires to warn user about it 6 ‘sp_inact’ Number of days after password expires until account is disabled 7 ‘sp_expire’ Number of days since 1970-01-01 when account expires 8 ‘sp_flag’ Reserved The sp_namp and sp_pwdp items are strings, all others are integers. *note KeyError: 2c7. is raised if the entry asked for cannot be found. The following functions are defined: -- Function: spwd.getspnam (name) Return the shadow password database entry for the given user name. Changed in version 3.6: Raises a *note PermissionError: 5ff. instead of *note KeyError: 2c7. if the user doesn’t have privileges. -- Function: spwd.getspall () Return a list of all available shadow password database entries, in arbitrary order. See also ........ Module *note grp: 8b. An interface to the group database, similar to this. Module *note pwd: d6. An interface to the normal password database, similar to this.  File: python.info, Node: grp — The group database, Next: crypt — Function to check Unix passwords, Prev: spwd — The shadow password database, Up: Unix Specific Services 5.35.4 ‘grp’ — The group database --------------------------------- __________________________________________________________________ This module provides access to the Unix group database. It is available on all Unix versions. Group database entries are reported as a tuple-like object, whose attributes correspond to the members of the ‘group’ structure (Attribute field below, see ‘<pwd.h>’): Index Attribute Meaning ------------------------------------------------------------------ 0 gr_name the name of the group 1 gr_passwd the (encrypted) group password; often empty 2 gr_gid the numerical group ID 3 gr_mem all the group member’s user names The gid is an integer, name and password are strings, and the member list is a list of strings. (Note that most users are not explicitly listed as members of the group they are in according to the password database. Check both databases to get complete membership information. Also note that a ‘gr_name’ that starts with a ‘+’ or ‘-’ is likely to be a YP/NIS reference and may not be accessible via *note getgrnam(): 3755. or *note getgrgid(): 5df.) It defines the following items: -- Function: grp.getgrgid (gid) Return the group database entry for the given numeric group ID. *note KeyError: 2c7. is raised if the entry asked for cannot be found. Deprecated since version 3.6: Since Python 3.6 the support of non-integer arguments like floats or strings in *note getgrgid(): 5df. is deprecated. -- Function: grp.getgrnam (name) Return the group database entry for the given group name. *note KeyError: 2c7. is raised if the entry asked for cannot be found. -- Function: grp.getgrall () Return a list of all available group entries, in arbitrary order. See also ........ Module *note pwd: d6. An interface to the user database, similar to this. Module *note spwd: f1. An interface to the shadow password database, similar to this.  File: python.info, Node: crypt — Function to check Unix passwords, Next: termios — POSIX style tty control, Prev: grp — The group database, Up: Unix Specific Services 5.35.5 ‘crypt’ — Function to check Unix passwords ------------------------------------------------- `Source code:' Lib/crypt.py(1) __________________________________________________________________ This module implements an interface to the ‘crypt(3)’ routine, which is a one-way hash function based upon a modified DES algorithm; see the Unix man page for further details. Possible uses include storing hashed passwords so you can check passwords without storing the actual password, or attempting to crack Unix passwords with a dictionary. Notice that the behavior of this module depends on the actual implementation of the ‘crypt(3)’ routine in the running system. Therefore, any extensions available on the current implementation will also be available on this module. *note Availability: ffb.: Unix. Not available on VxWorks. * Menu: * Hashing Methods:: * Module Attributes:: * Module Functions: Module Functions<2>. * Examples: Examples<31>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/crypt.py  File: python.info, Node: Hashing Methods, Next: Module Attributes, Up: crypt — Function to check Unix passwords 5.35.5.1 Hashing Methods ........................ New in version 3.3. The *note crypt: 29. module defines the list of hashing methods (not all methods are available on all platforms): -- Data: crypt.METHOD_SHA512 A Modular Crypt Format method with 16 character salt and 86 character hash based on the SHA-512 hash function. This is the strongest method. -- Data: crypt.METHOD_SHA256 Another Modular Crypt Format method with 16 character salt and 43 character hash based on the SHA-256 hash function. -- Data: crypt.METHOD_BLOWFISH Another Modular Crypt Format method with 22 character salt and 31 character hash based on the Blowfish cipher. New in version 3.7. -- Data: crypt.METHOD_MD5 Another Modular Crypt Format method with 8 character salt and 22 character hash based on the MD5 hash function. -- Data: crypt.METHOD_CRYPT The traditional method with a 2 character salt and 13 characters of hash. This is the weakest method.  File: python.info, Node: Module Attributes, Next: Module Functions<2>, Prev: Hashing Methods, Up: crypt — Function to check Unix passwords 5.35.5.2 Module Attributes .......................... New in version 3.3. -- Attribute: crypt.methods A list of available password hashing algorithms, as ‘crypt.METHOD_*’ objects. This list is sorted from strongest to weakest.  File: python.info, Node: Module Functions<2>, Next: Examples<31>, Prev: Module Attributes, Up: crypt — Function to check Unix passwords 5.35.5.3 Module Functions ......................... The *note crypt: 29. module defines the following functions: -- Function: crypt.crypt (word, salt=None) `word' will usually be a user’s password as typed at a prompt or in a graphical interface. The optional `salt' is either a string as returned from *note mksalt(): 37c, one of the ‘crypt.METHOD_*’ values (though not all may be available on all platforms), or a full encrypted password including salt, as returned by this function. If `salt' is not provided, the strongest method will be used (as returned by *note methods(): 375f.). Checking a password is usually done by passing the plain-text password as `word' and the full results of a previous *note crypt(): 29. call, which should be the same as the results of this call. `salt' (either a random 2 or 16 character string, possibly prefixed with ‘$digit$’ to indicate the method) which will be used to perturb the encryption algorithm. The characters in `salt' must be in the set ‘[./a-zA-Z0-9]’, with the exception of Modular Crypt Format which prefixes a ‘$digit$’. Returns the hashed password as a string, which will be composed of characters from the same alphabet as the salt. Since a few ‘crypt(3)’ extensions allow different values, with different sizes in the `salt', it is recommended to use the full crypted password as salt when checking for a password. Changed in version 3.3: Accept ‘crypt.METHOD_*’ values in addition to strings for `salt'. -- Function: crypt.mksalt (method=None, *, rounds=None) Return a randomly generated salt of the specified method. If no `method' is given, the strongest method available as returned by *note methods(): 375f. is used. The return value is a string suitable for passing as the `salt' argument to *note crypt(): 29. `rounds' specifies the number of rounds for ‘METHOD_SHA256’, ‘METHOD_SHA512’ and ‘METHOD_BLOWFISH’. For ‘METHOD_SHA256’ and ‘METHOD_SHA512’ it must be an integer between ‘1000’ and ‘999_999_999’, the default is ‘5000’. For ‘METHOD_BLOWFISH’ it must be a power of two between ‘16’ (2^4) and ‘2_147_483_648’ (2^31), the default is ‘4096’ (2^12). New in version 3.3. Changed in version 3.7: Added the `rounds' parameter.  File: python.info, Node: Examples<31>, Prev: Module Functions<2>, Up: crypt — Function to check Unix passwords 5.35.5.4 Examples ................. A simple example illustrating typical use (a constant-time comparison operation is needed to limit exposure to timing attacks. *note hmac.compare_digest(): a0c. is suitable for this purpose): import pwd import crypt import getpass from hmac import compare_digest as compare_hash def login(): username = input('Python login: ') cryptedpasswd = pwd.getpwnam(username)[1] if cryptedpasswd: if cryptedpasswd == 'x' or cryptedpasswd == '*': raise ValueError('no support for shadow passwords') cleartext = getpass.getpass() return compare_hash(crypt.crypt(cleartext, cryptedpasswd), cryptedpasswd) else: return True To generate a hash of a password using the strongest available method and check it against the original: import crypt from hmac import compare_digest as compare_hash hashed = crypt.crypt(plaintext) if not compare_hash(hashed, crypt.crypt(plaintext, hashed)): raise ValueError("hashed version doesn't validate against original")  File: python.info, Node: termios — POSIX style tty control, Next: tty — Terminal control functions, Prev: crypt — Function to check Unix passwords, Up: Unix Specific Services 5.35.6 ‘termios’ — POSIX style tty control ------------------------------------------ __________________________________________________________________ This module provides an interface to the POSIX calls for tty I/O control. For a complete description of these calls, see ‘termios(3)’ Unix manual page. It is only available for those Unix versions that support POSIX `termios' style tty I/O control configured during installation. All functions in this module take a file descriptor `fd' as their first argument. This can be an integer file descriptor, such as returned by ‘sys.stdin.fileno()’, or a *note file object: b42, such as ‘sys.stdin’ itself. This module also defines all the constants needed to work with the functions provided here; these have the same name as their counterparts in C. Please refer to your system documentation for more information on using these terminal control interfaces. The module defines the following functions: -- Function: termios.tcgetattr (fd) Return a list containing the tty attributes for file descriptor `fd', as follows: ‘[iflag, oflag, cflag, lflag, ispeed, ospeed, cc]’ where `cc' is a list of the tty special characters (each a string of length 1, except the items with indices ‘VMIN’ and ‘VTIME’, which are integers when these fields are defined). The interpretation of the flags and the speeds as well as the indexing in the `cc' array must be done using the symbolic constants defined in the *note termios: 104. module. -- Function: termios.tcsetattr (fd, when, attributes) Set the tty attributes for file descriptor `fd' from the `attributes', which is a list like the one returned by *note tcgetattr(): 3765. The `when' argument determines when the attributes are changed: ‘TCSANOW’ to change immediately, ‘TCSADRAIN’ to change after transmitting all queued output, or ‘TCSAFLUSH’ to change after transmitting all queued output and discarding all queued input. -- Function: termios.tcsendbreak (fd, duration) Send a break on file descriptor `fd'. A zero `duration' sends a break for 0.25–0.5 seconds; a nonzero `duration' has a system dependent meaning. -- Function: termios.tcdrain (fd) Wait until all output written to file descriptor `fd' has been transmitted. -- Function: termios.tcflush (fd, queue) Discard queued data on file descriptor `fd'. The `queue' selector specifies which queue: ‘TCIFLUSH’ for the input queue, ‘TCOFLUSH’ for the output queue, or ‘TCIOFLUSH’ for both queues. -- Function: termios.tcflow (fd, action) Suspend or resume input or output on file descriptor `fd'. The `action' argument can be ‘TCOOFF’ to suspend output, ‘TCOON’ to restart output, ‘TCIOFF’ to suspend input, or ‘TCION’ to restart input. See also ........ Module *note tty: 115. Convenience functions for common terminal control operations. * Menu: * Example: Example<16>.  File: python.info, Node: Example<16>, Up: termios — POSIX style tty control 5.35.6.1 Example ................ Here’s a function that prompts for a password with echoing turned off. Note the technique using a separate *note tcgetattr(): 3765. call and a *note try: d72. … *note finally: 182. statement to ensure that the old tty attributes are restored exactly no matter what happens: def getpass(prompt="Password: "): import termios, sys fd = sys.stdin.fileno() old = termios.tcgetattr(fd) new = termios.tcgetattr(fd) new[3] = new[3] & ~termios.ECHO # lflags try: termios.tcsetattr(fd, termios.TCSADRAIN, new) passwd = input(prompt) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old) return passwd  File: python.info, Node: tty — Terminal control functions, Next: pty — Pseudo-terminal utilities, Prev: termios — POSIX style tty control, Up: Unix Specific Services 5.35.7 ‘tty’ — Terminal control functions ----------------------------------------- `Source code:' Lib/tty.py(1) __________________________________________________________________ The *note tty: 115. module defines functions for putting the tty into cbreak and raw modes. Because it requires the *note termios: 104. module, it will work only on Unix. The *note tty: 115. module defines the following functions: -- Function: tty.setraw (fd, when=termios.TCSAFLUSH) Change the mode of the file descriptor `fd' to raw. If `when' is omitted, it defaults to ‘termios.TCSAFLUSH’, and is passed to *note termios.tcsetattr(): 3766. -- Function: tty.setcbreak (fd, when=termios.TCSAFLUSH) Change the mode of file descriptor `fd' to cbreak. If `when' is omitted, it defaults to ‘termios.TCSAFLUSH’, and is passed to *note termios.tcsetattr(): 3766. See also ........ Module *note termios: 104. Low-level terminal control interface. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/tty.py  File: python.info, Node: pty — Pseudo-terminal utilities, Next: fcntl — The fcntl and ioctl system calls, Prev: tty — Terminal control functions, Up: Unix Specific Services 5.35.8 ‘pty’ — Pseudo-terminal utilities ---------------------------------------- `Source code:' Lib/pty.py(1) __________________________________________________________________ The *note pty: d5. module defines operations for handling the pseudo-terminal concept: starting another process and being able to write to and read from its controlling terminal programmatically. Because pseudo-terminal handling is highly platform dependent, there is code to do it only for Linux. (The Linux code is supposed to work on other platforms, but hasn’t been tested yet.) The *note pty: d5. module defines the following functions: -- Function: pty.fork () Fork. Connect the child’s controlling terminal to a pseudo-terminal. Return value is ‘(pid, fd)’. Note that the child gets `pid' 0, and the `fd' is `invalid'. The parent’s return value is the `pid' of the child, and `fd' is a file descriptor connected to the child’s controlling terminal (and also to the child’s standard input and output). -- Function: pty.openpty () Open a new pseudo-terminal pair, using *note os.openpty(): 1c02. if possible, or emulation code for generic Unix systems. Return a pair of file descriptors ‘(master, slave)’, for the master and the slave end, respectively. -- Function: pty.spawn (argv[, master_read[, stdin_read]]) Spawn a process, and connect its controlling terminal with the current process’s standard io. This is often used to baffle programs which insist on reading from the controlling terminal. It is expected that the process spawned behind the pty will eventually terminate, and when it does `spawn' will return. The functions `master_read' and `stdin_read' are passed a file descriptor which they should read from, and they should always return a byte string. In order to force spawn to return before the child process exits an *note OSError: 1d3. should be thrown. The default implementation for both functions will read and return up to 1024 bytes each time the function is called. The `master_read' callback is passed the pseudoterminal’s master file descriptor to read output from the child process, and `stdin_read' is passed file descriptor 0, to read from the parent process’s standard input. Returning an empty byte string from either callback is interpreted as an end-of-file (EOF) condition, and that callback will not be called after that. If `stdin_read' signals EOF the controlling terminal can no longer communicate with the parent process OR the child process. Unless the child process will quit without any input, `spawn' will then loop forever. If `master_read' signals EOF the same behavior results (on linux at least). If both callbacks signal EOF then `spawn' will probably never return, unless `select' throws an error on your platform when passed three empty lists. This is a bug, documented in issue 26228(2). Raises an *note auditing event: fd1. ‘pty.spawn’ with argument ‘argv’. Changed in version 3.4: *note spawn(): 898. now returns the status value from *note os.waitpid(): 66d. on the child process. * Menu: * Example: Example<17>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pty.py (2) https://bugs.python.org/issue26228  File: python.info, Node: Example<17>, Up: pty — Pseudo-terminal utilities 5.35.8.1 Example ................ The following program acts like the Unix command ‘script(1)’, using a pseudo-terminal to record all input and output of a terminal session in a “typescript”. import argparse import os import pty import sys import time parser = argparse.ArgumentParser() parser.add_argument('-a', dest='append', action='store_true') parser.add_argument('-p', dest='use_python', action='store_true') parser.add_argument('filename', nargs='?', default='typescript') options = parser.parse_args() shell = sys.executable if options.use_python else os.environ.get('SHELL', 'sh') filename = options.filename mode = 'ab' if options.append else 'wb' with open(filename, mode) as script: def read(fd): data = os.read(fd, 1024) script.write(data) return data print('Script started, file is', filename) script.write(('Script started on %s\n' % time.asctime()).encode()) pty.spawn(shell, read) script.write(('Script done on %s\n' % time.asctime()).encode()) print('Script done, file is', filename)  File: python.info, Node: fcntl — The fcntl and ioctl system calls, Next: pipes — Interface to shell pipelines, Prev: pty — Pseudo-terminal utilities, Up: Unix Specific Services 5.35.9 ‘fcntl’ — The ‘fcntl’ and ‘ioctl’ system calls ----------------------------------------------------- __________________________________________________________________ This module performs file control and I/O control on file descriptors. It is an interface to the ‘fcntl()’ and ‘ioctl()’ Unix routines. For a complete description of these calls, see ‘fcntl(2)’ and ‘ioctl(2)’ Unix manual pages. All functions in this module take a file descriptor `fd' as their first argument. This can be an integer file descriptor, such as returned by ‘sys.stdin.fileno()’, or an *note io.IOBase: 1db. object, such as ‘sys.stdin’ itself, which provides a *note fileno(): 1bdb. that returns a genuine file descriptor. Changed in version 3.3: Operations in this module used to raise an *note IOError: 992. where they now raise an *note OSError: 1d3. Changed in version 3.8: The fcntl module now contains ‘F_ADD_SEALS’, ‘F_GET_SEALS’, and ‘F_SEAL_*’ constants for sealing of *note os.memfd_create(): 1f0. file descriptors. The module defines the following functions: -- Function: fcntl.fcntl (fd, cmd, arg=0) Perform the operation `cmd' on file descriptor `fd' (file objects providing a *note fileno(): 1bdb. method are accepted as well). The values used for `cmd' are operating system dependent, and are available as constants in the *note fcntl: 7e. module, using the same names as used in the relevant C header files. The argument `arg' can either be an integer value, or a *note bytes: 331. object. With an integer value, the return value of this function is the integer return value of the C ‘fcntl()’ call. When the argument is bytes it represents a binary structure, e.g. created by *note struct.pack(): c0b. The binary data is copied to a buffer whose address is passed to the C ‘fcntl()’ call. The return value after a successful call is the contents of the buffer, converted to a *note bytes: 331. object. The length of the returned object will be the same as the length of the `arg' argument. This is limited to 1024 bytes. If the information returned in the buffer by the operating system is larger than 1024 bytes, this is most likely to result in a segmentation violation or a more subtle data corruption. If the ‘fcntl()’ fails, an *note OSError: 1d3. is raised. Raises an *note auditing event: fd1. ‘fcntl.fcntl’ with arguments ‘fd’, ‘cmd’, ‘arg’. -- Function: fcntl.ioctl (fd, request, arg=0, mutate_flag=True) This function is identical to the *note fcntl(): 2393. function, except that the argument handling is even more complicated. The `request' parameter is limited to values that can fit in 32-bits. Additional constants of interest for use as the `request' argument can be found in the *note termios: 104. module, under the same names as used in the relevant C header files. The parameter `arg' can be one of an integer, an object supporting the read-only buffer interface (like *note bytes: 331.) or an object supporting the read-write buffer interface (like *note bytearray: 332.). In all but the last case, behaviour is as for the *note fcntl(): 2393. function. If a mutable buffer is passed, then the behaviour is determined by the value of the `mutate_flag' parameter. If it is false, the buffer’s mutability is ignored and behaviour is as for a read-only buffer, except that the 1024 byte limit mentioned above is avoided – so long as the buffer you pass is at least as long as what the operating system wants to put there, things should work. If `mutate_flag' is true (the default), then the buffer is (in effect) passed to the underlying *note ioctl(): dde. system call, the latter’s return code is passed back to the calling Python, and the buffer’s new contents reflect the action of the *note ioctl(): dde. This is a slight simplification, because if the supplied buffer is less than 1024 bytes long it is first copied into a static buffer 1024 bytes long which is then passed to *note ioctl(): dde. and copied back into the supplied buffer. If the ‘ioctl()’ fails, an *note OSError: 1d3. exception is raised. An example: >>> import array, fcntl, struct, termios, os >>> os.getpgrp() 13341 >>> struct.unpack('h', fcntl.ioctl(0, termios.TIOCGPGRP, " "))[0] 13341 >>> buf = array.array('h', [0]) >>> fcntl.ioctl(0, termios.TIOCGPGRP, buf, 1) 0 >>> buf array('h', [13341]) Raises an *note auditing event: fd1. ‘fcntl.ioctl’ with arguments ‘fd’, ‘request’, ‘arg’. -- Function: fcntl.flock (fd, operation) Perform the lock operation `operation' on file descriptor `fd' (file objects providing a *note fileno(): 1bdb. method are accepted as well). See the Unix manual ‘flock(2)’ for details. (On some systems, this function is emulated using ‘fcntl()’.) If the ‘flock()’ fails, an *note OSError: 1d3. exception is raised. Raises an *note auditing event: fd1. ‘fcntl.flock’ with arguments ‘fd’, ‘operation’. -- Function: fcntl.lockf (fd, cmd, len=0, start=0, whence=0) This is essentially a wrapper around the *note fcntl(): 2393. locking calls. `fd' is the file descriptor (file objects providing a *note fileno(): 1bdb. method are accepted as well) of the file to lock or unlock, and `cmd' is one of the following values: * ‘LOCK_UN’ – unlock * ‘LOCK_SH’ – acquire a shared lock * ‘LOCK_EX’ – acquire an exclusive lock When `cmd' is ‘LOCK_SH’ or ‘LOCK_EX’, it can also be bitwise ORed with ‘LOCK_NB’ to avoid blocking on lock acquisition. If ‘LOCK_NB’ is used and the lock cannot be acquired, an *note OSError: 1d3. will be raised and the exception will have an `errno' attribute set to ‘EACCES’ or ‘EAGAIN’ (depending on the operating system; for portability, check for both values). On at least some systems, ‘LOCK_EX’ can only be used if the file descriptor refers to a file opened for writing. `len' is the number of bytes to lock, `start' is the byte offset at which the lock starts, relative to `whence', and `whence' is as with *note io.IOBase.seek(): 1a62, specifically: * ‘0’ – relative to the start of the file (*note os.SEEK_SET: d94.) * ‘1’ – relative to the current buffer position (*note os.SEEK_CUR: d95.) * ‘2’ – relative to the end of the file (*note os.SEEK_END: d96.) The default for `start' is 0, which means to start at the beginning of the file. The default for `len' is 0 which means to lock to the end of the file. The default for `whence' is also 0. Raises an *note auditing event: fd1. ‘fcntl.lockf’ with arguments ‘fd’, ‘cmd’, ‘len’, ‘start’, ‘whence’. Examples (all on a SVR4 compliant system): import struct, fcntl, os f = open(...) rv = fcntl.fcntl(f, fcntl.F_SETFL, os.O_NDELAY) lockdata = struct.pack('hhllhh', fcntl.F_WRLCK, 0, 0, 0, 0, 0) rv = fcntl.fcntl(f, fcntl.F_SETLKW, lockdata) Note that in the first example the return value variable `rv' will hold an integer value; in the second example it will hold a *note bytes: 331. object. The structure lay-out for the `lockdata' variable is system dependent — therefore using the *note flock(): 31f3. call may be better. See also ........ Module *note os: c4. If the locking flags *note O_SHLOCK: d97. and *note O_EXLOCK: d98. are present in the *note os: c4. module (on BSD only), the *note os.open(): 665. function provides an alternative to the *note lockf(): d52. and *note flock(): 31f3. functions.  File: python.info, Node: pipes — Interface to shell pipelines, Next: resource — Resource usage information, Prev: fcntl — The fcntl and ioctl system calls, Up: Unix Specific Services 5.35.10 ‘pipes’ — Interface to shell pipelines ---------------------------------------------- `Source code:' Lib/pipes.py(1) __________________________________________________________________ The *note pipes: cc. module defines a class to abstract the concept of a `pipeline' — a sequence of converters from one file to another. Because the module uses ‘/bin/sh’ command lines, a POSIX or compatible shell for *note os.system(): dc1. and *note os.popen(): 2a9. is required. The *note pipes: cc. module defines the following class: -- Class: pipes.Template An abstraction of a pipeline. Example: >>> import pipes >>> t = pipes.Template() >>> t.append('tr a-z A-Z', '--') >>> f = t.open('pipefile', 'w') >>> f.write('hello world') >>> f.close() >>> open('pipefile').read() 'HELLO WORLD' * Menu: * Template Objects:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/pipes.py  File: python.info, Node: Template Objects, Up: pipes — Interface to shell pipelines 5.35.10.1 Template Objects .......................... Template objects following methods: -- Method: Template.reset () Restore a pipeline template to its initial state. -- Method: Template.clone () Return a new, equivalent, pipeline template. -- Method: Template.debug (flag) If `flag' is true, turn debugging on. Otherwise, turn debugging off. When debugging is on, commands to be executed are printed, and the shell is given ‘set -x’ command to be more verbose. -- Method: Template.append (cmd, kind) Append a new action at the end. The `cmd' variable must be a valid bourne shell command. The `kind' variable consists of two letters. The first letter can be either of ‘'-'’ (which means the command reads its standard input), ‘'f'’ (which means the commands reads a given file on the command line) or ‘'.'’ (which means the commands reads no input, and hence must be first.) Similarly, the second letter can be either of ‘'-'’ (which means the command writes to standard output), ‘'f'’ (which means the command writes a file on the command line) or ‘'.'’ (which means the command does not write anything, and hence must be last.) -- Method: Template.prepend (cmd, kind) Add a new action at the beginning. See *note append(): 3780. for explanations of the arguments. -- Method: Template.open (file, mode) Return a file-like object, open to `file', but read from or written to by the pipeline. Note that only one of ‘'r'’, ‘'w'’ may be given. -- Method: Template.copy (infile, outfile) Copy `infile' to `outfile' through the pipe.  File: python.info, Node: resource — Resource usage information, Next: nis — Interface to Sun’s NIS Yellow Pages, Prev: pipes — Interface to shell pipelines, Up: Unix Specific Services 5.35.11 ‘resource’ — Resource usage information ----------------------------------------------- __________________________________________________________________ This module provides basic mechanisms for measuring and controlling system resources utilized by a program. Symbolic constants are used to specify particular system resources and to request usage information about either the current process or its children. An *note OSError: 1d3. is raised on syscall failure. -- Exception: resource.error A deprecated alias of *note OSError: 1d3. Changed in version 3.3: Following PEP 3151(1), this class was made an alias of *note OSError: 1d3. * Menu: * Resource Limits:: * Resource Usage:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3151  File: python.info, Node: Resource Limits, Next: Resource Usage, Up: resource — Resource usage information 5.35.11.1 Resource Limits ......................... Resources usage can be limited using the *note setrlimit(): 31cd. function described below. Each resource is controlled by a pair of limits: a soft limit and a hard limit. The soft limit is the current limit, and may be lowered or raised by a process over time. The soft limit can never exceed the hard limit. The hard limit can be lowered to any value greater than the soft limit, but not raised. (Only processes with the effective UID of the super-user can raise a hard limit.) The specific resources that can be limited are system dependent. They are described in the ‘getrlimit(2)’ man page. The resources listed below are supported when the underlying operating system supports them; resources which cannot be checked or controlled by the operating system are not defined in this module for those platforms. -- Data: resource.RLIM_INFINITY Constant used to represent the limit for an unlimited resource. -- Function: resource.getrlimit (resource) Returns a tuple ‘(soft, hard)’ with the current soft and hard limits of `resource'. Raises *note ValueError: 1fb. if an invalid resource is specified, or *note error: 3786. if the underlying system call fails unexpectedly. -- Function: resource.setrlimit (resource, limits) Sets new limits of consumption of `resource'. The `limits' argument must be a tuple ‘(soft, hard)’ of two integers describing the new limits. A value of *note RLIM_INFINITY: 3788. can be used to request a limit that is unlimited. Raises *note ValueError: 1fb. if an invalid resource is specified, if the new soft limit exceeds the hard limit, or if a process tries to raise its hard limit. Specifying a limit of *note RLIM_INFINITY: 3788. when the hard or system limit for that resource is not unlimited will result in a *note ValueError: 1fb. A process with the effective UID of super-user can request any valid limit value, including unlimited, but *note ValueError: 1fb. will still be raised if the requested limit exceeds the system imposed limit. ‘setrlimit’ may also raise *note error: 3786. if the underlying system call fails. VxWorks only supports setting *note RLIMIT_NOFILE: 378a. Raises an *note auditing event: fd1. ‘resource.setrlimit’ with arguments ‘resource’, ‘limits’. -- Function: resource.prlimit (pid, resource[, limits]) Combines *note setrlimit(): 31cd. and *note getrlimit(): 3789. in one function and supports to get and set the resources limits of an arbitrary process. If `pid' is 0, then the call applies to the current process. `resource' and `limits' have the same meaning as in *note setrlimit(): 31cd, except that `limits' is optional. When `limits' is not given the function returns the `resource' limit of the process `pid'. When `limits' is given the `resource' limit of the process is set and the former resource limit is returned. Raises *note ProcessLookupError: 99b. when `pid' can’t be found and *note PermissionError: 5ff. when the user doesn’t have ‘CAP_SYS_RESOURCE’ for the process. Raises an *note auditing event: fd1. ‘resource.prlimit’ with arguments ‘pid’, ‘resource’, ‘limits’. *note Availability: ffb.: Linux 2.6.36 or later with glibc 2.13 or later. New in version 3.4. These symbols define resources whose consumption can be controlled using the *note setrlimit(): 31cd. and *note getrlimit(): 3789. functions described below. The values of these symbols are exactly the constants used by C programs. The Unix man page for ‘getrlimit(2)’ lists the available resources. Note that not all systems use the same symbol or same value to denote the same resource. This module does not attempt to mask platform differences — symbols not defined for a platform will not be available from this module on that platform. -- Data: resource.RLIMIT_CORE The maximum size (in bytes) of a core file that the current process can create. This may result in the creation of a partial core file if a larger core would be required to contain the entire process image. -- Data: resource.RLIMIT_CPU The maximum amount of processor time (in seconds) that a process can use. If this limit is exceeded, a ‘SIGXCPU’ signal is sent to the process. (See the *note signal: ea. module documentation for information about how to catch this signal and do something useful, e.g. flush open files to disk.) -- Data: resource.RLIMIT_FSIZE The maximum size of a file which the process may create. -- Data: resource.RLIMIT_DATA The maximum size (in bytes) of the process’s heap. -- Data: resource.RLIMIT_STACK The maximum size (in bytes) of the call stack for the current process. This only affects the stack of the main thread in a multi-threaded process. -- Data: resource.RLIMIT_RSS The maximum resident set size that should be made available to the process. -- Data: resource.RLIMIT_NPROC The maximum number of processes the current process may create. -- Data: resource.RLIMIT_NOFILE The maximum number of open file descriptors for the current process. -- Data: resource.RLIMIT_OFILE The BSD name for *note RLIMIT_NOFILE: 378a. -- Data: resource.RLIMIT_MEMLOCK The maximum address space which may be locked in memory. -- Data: resource.RLIMIT_VMEM The largest area of mapped memory which the process may occupy. -- Data: resource.RLIMIT_AS The maximum area (in bytes) of address space which may be taken by the process. -- Data: resource.RLIMIT_MSGQUEUE The number of bytes that can be allocated for POSIX message queues. *note Availability: ffb.: Linux 2.6.8 or later. New in version 3.4. -- Data: resource.RLIMIT_NICE The ceiling for the process’s nice level (calculated as 20 - rlim_cur). *note Availability: ffb.: Linux 2.6.12 or later. New in version 3.4. -- Data: resource.RLIMIT_RTPRIO The ceiling of the real-time priority. *note Availability: ffb.: Linux 2.6.12 or later. New in version 3.4. -- Data: resource.RLIMIT_RTTIME The time limit (in microseconds) on CPU time that a process can spend under real-time scheduling without making a blocking syscall. *note Availability: ffb.: Linux 2.6.25 or later. New in version 3.4. -- Data: resource.RLIMIT_SIGPENDING The number of signals which the process may queue. *note Availability: ffb.: Linux 2.6.8 or later. New in version 3.4. -- Data: resource.RLIMIT_SBSIZE The maximum size (in bytes) of socket buffer usage for this user. This limits the amount of network memory, and hence the amount of mbufs, that this user may hold at any time. *note Availability: ffb.: FreeBSD 9 or later. New in version 3.4. -- Data: resource.RLIMIT_SWAP The maximum size (in bytes) of the swap space that may be reserved or used by all of this user id’s processes. This limit is enforced only if bit 1 of the vm.overcommit sysctl is set. Please see tuning(7)(1) for a complete description of this sysctl. *note Availability: ffb.: FreeBSD 9 or later. New in version 3.4. -- Data: resource.RLIMIT_NPTS The maximum number of pseudo-terminals created by this user id. *note Availability: ffb.: FreeBSD 9 or later. New in version 3.4. ---------- Footnotes ---------- (1) https://www.freebsd.org/cgi/man.cgi?query=tuning&sektion=7  File: python.info, Node: Resource Usage, Prev: Resource Limits, Up: resource — Resource usage information 5.35.11.2 Resource Usage ........................ These functions are used to retrieve resource usage information: -- Function: resource.getrusage (who) This function returns an object that describes the resources consumed by either the current process or its children, as specified by the `who' parameter. The `who' parameter should be specified using one of the ‘RUSAGE_*’ constants described below. A simple example: from resource import * import time # a non CPU-bound task time.sleep(3) print(getrusage(RUSAGE_SELF)) # a CPU-bound task for i in range(10 ** 8): _ = 1 + 1 print(getrusage(RUSAGE_SELF)) The fields of the return value each describe how a particular system resource has been used, e.g. amount of time spent running is user mode or number of times the process was swapped out of main memory. Some values are dependent on the clock tick internal, e.g. the amount of memory the process is using. For backward compatibility, the return value is also accessible as a tuple of 16 elements. The fields ‘ru_utime’ and ‘ru_stime’ of the return value are floating point values representing the amount of time spent executing in user mode and the amount of time spent executing in system mode, respectively. The remaining values are integers. Consult the ‘getrusage(2)’ man page for detailed information about these values. A brief summary is presented here: Index Field Resource ----------------------------------------------------------------------------------- ‘0’ ‘ru_utime’ time in user mode (float seconds) ‘1’ ‘ru_stime’ time in system mode (float seconds) ‘2’ ‘ru_maxrss’ maximum resident set size ‘3’ ‘ru_ixrss’ shared memory size ‘4’ ‘ru_idrss’ unshared memory size ‘5’ ‘ru_isrss’ unshared stack size ‘6’ ‘ru_minflt’ page faults not requiring I/O ‘7’ ‘ru_majflt’ page faults requiring I/O ‘8’ ‘ru_nswap’ number of swap outs ‘9’ ‘ru_inblock’ block input operations ‘10’ ‘ru_oublock’ block output operations ‘11’ ‘ru_msgsnd’ messages sent ‘12’ ‘ru_msgrcv’ messages received ‘13’ ‘ru_nsignals’ signals received ‘14’ ‘ru_nvcsw’ voluntary context switches ‘15’ ‘ru_nivcsw’ involuntary context switches This function will raise a *note ValueError: 1fb. if an invalid `who' parameter is specified. It may also raise *note error: 3786. exception in unusual circumstances. -- Function: resource.getpagesize () Returns the number of bytes in a system page. (This need not be the same as the hardware page size.) The following ‘RUSAGE_*’ symbols are passed to the *note getrusage(): d99. function to specify which processes information should be provided for. -- Data: resource.RUSAGE_SELF Pass to *note getrusage(): d99. to request resources consumed by the calling process, which is the sum of resources used by all threads in the process. -- Data: resource.RUSAGE_CHILDREN Pass to *note getrusage(): d99. to request resources consumed by child processes of the calling process which have been terminated and waited for. -- Data: resource.RUSAGE_BOTH Pass to *note getrusage(): d99. to request resources consumed by both the current process and child processes. May not be available on all systems. -- Data: resource.RUSAGE_THREAD Pass to *note getrusage(): d99. to request resources consumed by the current thread. May not be available on all systems. New in version 3.2.  File: python.info, Node: nis — Interface to Sun’s NIS Yellow Pages, Next: syslog — Unix syslog library routines, Prev: resource — Resource usage information, Up: Unix Specific Services 5.35.12 ‘nis’ — Interface to Sun’s NIS (Yellow Pages) ----------------------------------------------------- __________________________________________________________________ The *note nis: bf. module gives a thin wrapper around the NIS library, useful for central administration of several hosts. Because NIS exists only on Unix systems, this module is only available for Unix. The *note nis: bf. module defines the following functions: -- Function: nis.match (key, mapname, domain=default_domain) Return the match for `key' in map `mapname', or raise an error (*note nis.error: 379d.) if there is none. Both should be strings, `key' is 8-bit clean. Return value is an arbitrary array of bytes (may contain ‘NULL’ and other joys). Note that `mapname' is first checked if it is an alias to another name. The `domain' argument allows overriding the NIS domain used for the lookup. If unspecified, lookup is in the default NIS domain. -- Function: nis.cat (mapname, domain=default_domain) Return a dictionary mapping `key' to `value' such that ‘match(key, mapname)==value’. Note that both keys and values of the dictionary are arbitrary arrays of bytes. Note that `mapname' is first checked if it is an alias to another name. The `domain' argument allows overriding the NIS domain used for the lookup. If unspecified, lookup is in the default NIS domain. -- Function: nis.maps (domain=default_domain) Return a list of all valid maps. The `domain' argument allows overriding the NIS domain used for the lookup. If unspecified, lookup is in the default NIS domain. -- Function: nis.get_default_domain () Return the system default NIS domain. The *note nis: bf. module defines the following exception: -- Exception: nis.error An error raised when a NIS function returns an error code.  File: python.info, Node: syslog — Unix syslog library routines, Prev: nis — Interface to Sun’s NIS Yellow Pages, Up: Unix Specific Services 5.35.13 ‘syslog’ — Unix syslog library routines ----------------------------------------------- __________________________________________________________________ This module provides an interface to the Unix ‘syslog’ library routines. Refer to the Unix manual pages for a detailed description of the ‘syslog’ facility. This module wraps the system ‘syslog’ family of routines. A pure Python library that can speak to a syslog server is available in the *note logging.handlers: ac. module as ‘SysLogHandler’. The module defines the following functions: -- Function: syslog.syslog (message) -- Function: syslog.syslog (priority, message) Send the string `message' to the system logger. A trailing newline is added if necessary. Each message is tagged with a priority composed of a `facility' and a `level'. The optional `priority' argument, which defaults to ‘LOG_INFO’, determines the message priority. If the facility is not encoded in `priority' using logical-or (‘LOG_INFO | LOG_USER’), the value given in the *note openlog(): 31fa. call is used. If *note openlog(): 31fa. has not been called prior to the call to *note syslog(): ff, ‘openlog()’ will be called with no arguments. Raises an *note auditing event: fd1. ‘syslog.syslog’ with arguments ‘priority’, ‘message’. -- Function: syslog.openlog ([ident[, logoption[, facility]]]) Logging options of subsequent *note syslog(): ff. calls can be set by calling *note openlog(): 31fa. *note syslog(): ff. will call *note openlog(): 31fa. with no arguments if the log is not currently open. The optional `ident' keyword argument is a string which is prepended to every message, and defaults to ‘sys.argv[0]’ with leading path components stripped. The optional `logoption' keyword argument (default is 0) is a bit field – see below for possible values to combine. The optional `facility' keyword argument (default is ‘LOG_USER’) sets the default facility for messages which do not have a facility explicitly encoded. Raises an *note auditing event: fd1. ‘syslog.openlog’ with arguments ‘ident’, ‘logoption’, ‘facility’. Changed in version 3.2: In previous versions, keyword arguments were not allowed, and `ident' was required. The default for `ident' was dependent on the system libraries, and often was ‘python’ instead of the name of the Python program file. -- Function: syslog.closelog () Reset the syslog module values and call the system library ‘closelog()’. This causes the module to behave as it does when initially imported. For example, *note openlog(): 31fa. will be called on the first *note syslog(): ff. call (if *note openlog(): 31fa. hasn’t already been called), and `ident' and other *note openlog(): 31fa. parameters are reset to defaults. Raises an *note auditing event: fd1. ‘syslog.closelog’ with no arguments. -- Function: syslog.setlogmask (maskpri) Set the priority mask to `maskpri' and return the previous mask value. Calls to *note syslog(): ff. with a priority level not set in `maskpri' are ignored. The default is to log all priorities. The function ‘LOG_MASK(pri)’ calculates the mask for the individual priority `pri'. The function ‘LOG_UPTO(pri)’ calculates the mask for all priorities up to and including `pri'. Raises an *note auditing event: fd1. ‘syslog.setlogmask’ with argument ‘maskpri’. The module defines the following constants: Priority levels (high to low): ‘LOG_EMERG’, ‘LOG_ALERT’, ‘LOG_CRIT’, ‘LOG_ERR’, ‘LOG_WARNING’, ‘LOG_NOTICE’, ‘LOG_INFO’, ‘LOG_DEBUG’. Facilities: ‘LOG_KERN’, ‘LOG_USER’, ‘LOG_MAIL’, ‘LOG_DAEMON’, ‘LOG_AUTH’, ‘LOG_LPR’, ‘LOG_NEWS’, ‘LOG_UUCP’, ‘LOG_CRON’, ‘LOG_SYSLOG’, ‘LOG_LOCAL0’ to ‘LOG_LOCAL7’, and, if defined in ‘<syslog.h>’, ‘LOG_AUTHPRIV’. Log options: ‘LOG_PID’, ‘LOG_CONS’, ‘LOG_NDELAY’, and, if defined in ‘<syslog.h>’, ‘LOG_ODELAY’, ‘LOG_NOWAIT’, and ‘LOG_PERROR’. * Menu: * Examples: Examples<32>.  File: python.info, Node: Examples<32>, Up: syslog — Unix syslog library routines 5.35.13.1 Examples .................. * Menu: * Simple example::  File: python.info, Node: Simple example, Up: Examples<32> 5.35.13.2 Simple example ........................ A simple set of examples: import syslog syslog.syslog('Processing started') if error: syslog.syslog(syslog.LOG_ERR, 'Processing started') An example of setting some log options, these would include the process ID in logged messages, and write the messages to the destination facility used for mail logging: syslog.openlog(logoption=syslog.LOG_PID, facility=syslog.LOG_MAIL) syslog.syslog('E-mail processing initiated...')  File: python.info, Node: Superseded Modules, Next: Undocumented Modules, Prev: Unix Specific Services, Up: The Python Standard Library 5.36 Superseded Modules ======================= The modules described in this chapter are deprecated and only kept for backwards compatibility. They have been superseded by other modules. * Menu: * optparse — Parser for command line options:: * imp — Access the import internals::  File: python.info, Node: optparse — Parser for command line options, Next: imp — Access the import internals, Up: Superseded Modules 5.36.1 ‘optparse’ — Parser for command line options --------------------------------------------------- `Source code:' Lib/optparse.py(1) Deprecated since version 3.2: The *note optparse: c3. module is deprecated and will not be developed further; development will continue with the *note argparse: 6. module. __________________________________________________________________ *note optparse: c3. is a more convenient, flexible, and powerful library for parsing command-line options than the old *note getopt: 87. module. *note optparse: c3. uses a more declarative style of command-line parsing: you create an instance of *note OptionParser: 37a9, populate it with options, and parse the command line. *note optparse: c3. allows users to specify options in the conventional GNU/POSIX syntax, and additionally generates usage and help messages for you. Here’s an example of using *note optparse: c3. in a simple script: from optparse import OptionParser ... parser = OptionParser() parser.add_option("-f", "--file", dest="filename", help="write report to FILE", metavar="FILE") parser.add_option("-q", "--quiet", action="store_false", dest="verbose", default=True, help="don't print status messages to stdout") (options, args) = parser.parse_args() With these few lines of code, users of your script can now do the “usual thing” on the command-line, for example: <yourscript> --file=outfile -q As it parses the command line, *note optparse: c3. sets attributes of the ‘options’ object returned by ‘parse_args()’ based on user-supplied command-line values. When ‘parse_args()’ returns from parsing this command line, ‘options.filename’ will be ‘"outfile"’ and ‘options.verbose’ will be ‘False’. *note optparse: c3. supports both long and short options, allows short options to be merged together, and allows options to be associated with their arguments in a variety of ways. Thus, the following command lines are all equivalent to the above example: <yourscript> -f outfile --quiet <yourscript> --quiet --file outfile <yourscript> -q -foutfile <yourscript> -qfoutfile Additionally, users can run one of the following <yourscript> -h <yourscript> --help and *note optparse: c3. will print out a brief summary of your script’s options: Usage: <yourscript> [options] Options: -h, --help show this help message and exit -f FILE, --file=FILE write report to FILE -q, --quiet don't print status messages to stdout where the value of `yourscript' is determined at runtime (normally from ‘sys.argv[0]’). * Menu: * Background:: * Tutorial: Tutorial<2>. * Reference Guide:: * Option Callbacks:: * Extending optparse:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/optparse.py  File: python.info, Node: Background, Next: Tutorial<2>, Up: optparse — Parser for command line options 5.36.1.1 Background ................... *note optparse: c3. was explicitly designed to encourage the creation of programs with straightforward, conventional command-line interfaces. To that end, it supports only the most common command-line syntax and semantics conventionally used under Unix. If you are unfamiliar with these conventions, read this section to acquaint yourself with them. * Menu: * Terminology:: * What are options for?:: * What are positional arguments for?::  File: python.info, Node: Terminology, Next: What are options for?, Up: Background 5.36.1.2 Terminology .................... argument a string entered on the command-line, and passed by the shell to ‘execl()’ or ‘execv()’. In Python, arguments are elements of ‘sys.argv[1:]’ (‘sys.argv[0]’ is the name of the program being executed). Unix shells also use the term “word”. It is occasionally desirable to substitute an argument list other than ‘sys.argv[1:]’, so you should read “argument” as “an element of ‘sys.argv[1:]’, or of some other list provided as a substitute for ‘sys.argv[1:]’”. option an argument used to supply extra information to guide or customize the execution of a program. There are many different syntaxes for options; the traditional Unix syntax is a hyphen (“-”) followed by a single letter, e.g. ‘-x’ or ‘-F’. Also, traditional Unix syntax allows multiple options to be merged into a single argument, e.g. ‘-x -F’ is equivalent to ‘-xF’. The GNU project introduced ‘--’ followed by a series of hyphen-separated words, e.g. ‘--file’ or ‘--dry-run’. These are the only two option syntaxes provided by *note optparse: c3. Some other option syntaxes that the world has seen include: * a hyphen followed by a few letters, e.g. ‘-pf’ (this is `not' the same as multiple options merged into a single argument) * a hyphen followed by a whole word, e.g. ‘-file’ (this is technically equivalent to the previous syntax, but they aren’t usually seen in the same program) * a plus sign followed by a single letter, or a few letters, or a word, e.g. ‘+f’, ‘+rgb’ * a slash followed by a letter, or a few letters, or a word, e.g. ‘/f’, ‘/file’ These option syntaxes are not supported by *note optparse: c3, and they never will be. This is deliberate: the first three are non-standard on any environment, and the last only makes sense if you’re exclusively targeting VMS, MS-DOS, and/or Windows. option argument an argument that follows an option, is closely associated with that option, and is consumed from the argument list when that option is. With *note optparse: c3, option arguments may either be in a separate argument from their option: -f foo --file foo or included in the same argument: -ffoo --file=foo Typically, a given option either takes an argument or it doesn’t. Lots of people want an “optional option arguments” feature, meaning that some options will take an argument if they see it, and won’t if they don’t. This is somewhat controversial, because it makes parsing ambiguous: if ‘-a’ takes an optional argument and ‘-b’ is another option entirely, how do we interpret ‘-ab’? Because of this ambiguity, *note optparse: c3. does not support this feature. positional argument something leftover in the argument list after options have been parsed, i.e. after options and their arguments have been parsed and removed from the argument list. required option an option that must be supplied on the command-line; note that the phrase “required option” is self-contradictory in English. *note optparse: c3. doesn’t prevent you from implementing required options, but doesn’t give you much help at it either. For example, consider this hypothetical command-line: prog -v --report report.txt foo bar ‘-v’ and ‘--report’ are both options. Assuming that ‘--report’ takes one argument, ‘report.txt’ is an option argument. ‘foo’ and ‘bar’ are positional arguments.  File: python.info, Node: What are options for?, Next: What are positional arguments for?, Prev: Terminology, Up: Background 5.36.1.3 What are options for? .............................. Options are used to provide extra information to tune or customize the execution of a program. In case it wasn’t clear, options are usually `optional'. A program should be able to run just fine with no options whatsoever. (Pick a random program from the Unix or GNU toolsets. Can it run without any options at all and still make sense? The main exceptions are ‘find’, ‘tar’, and ‘dd’—all of which are mutant oddballs that have been rightly criticized for their non-standard syntax and confusing interfaces.) Lots of people want their programs to have “required options”. Think about it. If it’s required, then it’s `not optional'! If there is a piece of information that your program absolutely requires in order to run successfully, that’s what positional arguments are for. As an example of good command-line interface design, consider the humble ‘cp’ utility, for copying files. It doesn’t make much sense to try to copy files without supplying a destination and at least one source. Hence, ‘cp’ fails if you run it with no arguments. However, it has a flexible, useful syntax that does not require any options at all: cp SOURCE DEST cp SOURCE ... DEST-DIR You can get pretty far with just that. Most ‘cp’ implementations provide a bunch of options to tweak exactly how the files are copied: you can preserve mode and modification time, avoid following symlinks, ask before clobbering existing files, etc. But none of this distracts from the core mission of ‘cp’, which is to copy either one file to another, or several files to another directory.  File: python.info, Node: What are positional arguments for?, Prev: What are options for?, Up: Background 5.36.1.4 What are positional arguments for? ........................................... Positional arguments are for those pieces of information that your program absolutely, positively requires to run. A good user interface should have as few absolute requirements as possible. If your program requires 17 distinct pieces of information in order to run successfully, it doesn’t much matter `how' you get that information from the user—most people will give up and walk away before they successfully run the program. This applies whether the user interface is a command-line, a configuration file, or a GUI: if you make that many demands on your users, most of them will simply give up. In short, try to minimize the amount of information that users are absolutely required to supply—use sensible defaults whenever possible. Of course, you also want to make your programs reasonably flexible. That’s what options are for. Again, it doesn’t matter if they are entries in a config file, widgets in the “Preferences” dialog of a GUI, or command-line options—the more options you implement, the more flexible your program is, and the more complicated its implementation becomes. Too much flexibility has drawbacks as well, of course; too many options can overwhelm users and make your code much harder to maintain.  File: python.info, Node: Tutorial<2>, Next: Reference Guide, Prev: Background, Up: optparse — Parser for command line options 5.36.1.5 Tutorial ................. While *note optparse: c3. is quite flexible and powerful, it’s also straightforward to use in most cases. This section covers the code patterns that are common to any *note optparse: c3.-based program. First, you need to import the OptionParser class; then, early in the main program, create an OptionParser instance: from optparse import OptionParser ... parser = OptionParser() Then you can start defining options. The basic syntax is: parser.add_option(opt_str, ..., attr=value, ...) Each option has one or more option strings, such as ‘-f’ or ‘--file’, and several option attributes that tell *note optparse: c3. what to expect and what to do when it encounters that option on the command line. Typically, each option will have one short option string and one long option string, e.g.: parser.add_option("-f", "--file", ...) You’re free to define as many short option strings and as many long option strings as you like (including zero), as long as there is at least one option string overall. The option strings passed to *note OptionParser.add_option(): 1d4f. are effectively labels for the option defined by that call. For brevity, we will frequently refer to `encountering an option' on the command line; in reality, *note optparse: c3. encounters `option strings' and looks up options from them. Once all of your options are defined, instruct *note optparse: c3. to parse your program’s command line: (options, args) = parser.parse_args() (If you like, you can pass a custom argument list to ‘parse_args()’, but that’s rarely necessary: by default it uses ‘sys.argv[1:]’.) ‘parse_args()’ returns two values: * ‘options’, an object containing values for all of your options—e.g. if ‘--file’ takes a single string argument, then ‘options.file’ will be the filename supplied by the user, or ‘None’ if the user did not supply that option * ‘args’, the list of positional arguments leftover after parsing options This tutorial section only covers the four most important option attributes: *note action: 37b4, *note type: 37b5, *note dest: 37b6. (destination), and *note help: 37b7. Of these, *note action: 37b4. is the most fundamental. * Menu: * Understanding option actions:: * The store action:: * Handling boolean (flag) options: Handling boolean flag options. * Other actions:: * Default values:: * Generating help:: * Printing a version string:: * How optparse handles errors:: * Putting it all together::  File: python.info, Node: Understanding option actions, Next: The store action, Up: Tutorial<2> 5.36.1.6 Understanding option actions ..................................... Actions tell *note optparse: c3. what to do when it encounters an option on the command line. There is a fixed set of actions hard-coded into *note optparse: c3.; adding new actions is an advanced topic covered in section *note Extending optparse: 37ba. Most actions tell *note optparse: c3. to store a value in some variable—for example, take a string from the command line and store it in an attribute of ‘options’. If you don’t specify an option action, *note optparse: c3. defaults to ‘store’.  File: python.info, Node: The store action, Next: Handling boolean flag options, Prev: Understanding option actions, Up: Tutorial<2> 5.36.1.7 The store action ......................... The most common option action is ‘store’, which tells *note optparse: c3. to take the next argument (or the remainder of the current argument), ensure that it is of the correct type, and store it to your chosen destination. For example: parser.add_option("-f", "--file", action="store", type="string", dest="filename") Now let’s make up a fake command line and ask *note optparse: c3. to parse it: args = ["-f", "foo.txt"] (options, args) = parser.parse_args(args) When *note optparse: c3. sees the option string ‘-f’, it consumes the next argument, ‘foo.txt’, and stores it in ‘options.filename’. So, after this call to ‘parse_args()’, ‘options.filename’ is ‘"foo.txt"’. Some other option types supported by *note optparse: c3. are ‘int’ and ‘float’. Here’s an option that expects an integer argument: parser.add_option("-n", type="int", dest="num") Note that this option has no long option string, which is perfectly acceptable. Also, there’s no explicit action, since the default is ‘store’. Let’s parse another fake command-line. This time, we’ll jam the option argument right up against the option: since ‘-n42’ (one argument) is equivalent to ‘-n 42’ (two arguments), the code (options, args) = parser.parse_args(["-n42"]) print(options.num) will print ‘42’. If you don’t specify a type, *note optparse: c3. assumes ‘string’. Combined with the fact that the default action is ‘store’, that means our first example can be a lot shorter: parser.add_option("-f", "--file", dest="filename") If you don’t supply a destination, *note optparse: c3. figures out a sensible default from the option strings: if the first long option string is ‘--foo-bar’, then the default destination is ‘foo_bar’. If there are no long option strings, *note optparse: c3. looks at the first short option string: the default destination for ‘-f’ is ‘f’. *note optparse: c3. also includes the built-in ‘complex’ type. Adding types is covered in section *note Extending optparse: 37ba.  File: python.info, Node: Handling boolean flag options, Next: Other actions, Prev: The store action, Up: Tutorial<2> 5.36.1.8 Handling boolean (flag) options ........................................ Flag options—set a variable to true or false when a particular option is seen—are quite common. *note optparse: c3. supports them with two separate actions, ‘store_true’ and ‘store_false’. For example, you might have a ‘verbose’ flag that is turned on with ‘-v’ and off with ‘-q’: parser.add_option("-v", action="store_true", dest="verbose") parser.add_option("-q", action="store_false", dest="verbose") Here we have two different options with the same destination, which is perfectly OK. (It just means you have to be a bit careful when setting default values—see below.) When *note optparse: c3. encounters ‘-v’ on the command line, it sets ‘options.verbose’ to ‘True’; when it encounters ‘-q’, ‘options.verbose’ is set to ‘False’.  File: python.info, Node: Other actions, Next: Default values, Prev: Handling boolean flag options, Up: Tutorial<2> 5.36.1.9 Other actions ...................... Some other actions supported by *note optparse: c3. are: ‘"store_const"’ store a constant value ‘"append"’ append this option’s argument to a list ‘"count"’ increment a counter by one ‘"callback"’ call a specified function These are covered in section *note Reference Guide: 37c1, and section *note Option Callbacks: 37c2.  File: python.info, Node: Default values, Next: Generating help, Prev: Other actions, Up: Tutorial<2> 5.36.1.10 Default values ........................ All of the above examples involve setting some variable (the “destination”) when certain command-line options are seen. What happens if those options are never seen? Since we didn’t supply any defaults, they are all set to ‘None’. This is usually fine, but sometimes you want more control. *note optparse: c3. lets you supply a default value for each destination, which is assigned before the command line is parsed. First, consider the verbose/quiet example. If we want *note optparse: c3. to set ‘verbose’ to ‘True’ unless ‘-q’ is seen, then we can do this: parser.add_option("-v", action="store_true", dest="verbose", default=True) parser.add_option("-q", action="store_false", dest="verbose") Since default values apply to the `destination' rather than to any particular option, and these two options happen to have the same destination, this is exactly equivalent: parser.add_option("-v", action="store_true", dest="verbose") parser.add_option("-q", action="store_false", dest="verbose", default=True) Consider this: parser.add_option("-v", action="store_true", dest="verbose", default=False) parser.add_option("-q", action="store_false", dest="verbose", default=True) Again, the default value for ‘verbose’ will be ‘True’: the last default value supplied for any particular destination is the one that counts. A clearer way to specify default values is the ‘set_defaults()’ method of OptionParser, which you can call at any time before calling ‘parse_args()’: parser.set_defaults(verbose=True) parser.add_option(...) (options, args) = parser.parse_args() As before, the last value specified for a given option destination is the one that counts. For clarity, try to use one method or the other of setting default values, not both.  File: python.info, Node: Generating help, Next: Printing a version string, Prev: Default values, Up: Tutorial<2> 5.36.1.11 Generating help ......................... *note optparse: c3.’s ability to generate help and usage text automatically is useful for creating user-friendly command-line interfaces. All you have to do is supply a *note help: 37b7. value for each option, and optionally a short usage message for your whole program. Here’s an OptionParser populated with user-friendly (documented) options: usage = "usage: %prog [options] arg1 arg2" parser = OptionParser(usage=usage) parser.add_option("-v", "--verbose", action="store_true", dest="verbose", default=True, help="make lots of noise [default]") parser.add_option("-q", "--quiet", action="store_false", dest="verbose", help="be vewwy quiet (I'm hunting wabbits)") parser.add_option("-f", "--filename", metavar="FILE", help="write output to FILE") parser.add_option("-m", "--mode", default="intermediate", help="interaction mode: novice, intermediate, " "or expert [default: %default]") If *note optparse: c3. encounters either ‘-h’ or ‘--help’ on the command-line, or if you just call ‘parser.print_help()’, it prints the following to standard output: Usage: <yourscript> [options] arg1 arg2 Options: -h, --help show this help message and exit -v, --verbose make lots of noise [default] -q, --quiet be vewwy quiet (I'm hunting wabbits) -f FILE, --filename=FILE write output to FILE -m MODE, --mode=MODE interaction mode: novice, intermediate, or expert [default: intermediate] (If the help output is triggered by a help option, *note optparse: c3. exits after printing the help text.) There’s a lot going on here to help *note optparse: c3. generate the best possible help message: * the script defines its own usage message: usage = "usage: %prog [options] arg1 arg2" *note optparse: c3. expands ‘%prog’ in the usage string to the name of the current program, i.e. ‘os.path.basename(sys.argv[0])’. The expanded string is then printed before the detailed option help. If you don’t supply a usage string, *note optparse: c3. uses a bland but sensible default: ‘"Usage: %prog [options]"’, which is fine if your script doesn’t take any positional arguments. * every option defines a help string, and doesn’t worry about line-wrapping—*note optparse: c3. takes care of wrapping lines and making the help output look good. * options that take a value indicate this fact in their automatically-generated help message, e.g. for the “mode” option: -m MODE, --mode=MODE Here, “MODE” is called the meta-variable: it stands for the argument that the user is expected to supply to ‘-m’/‘--mode’. By default, *note optparse: c3. converts the destination variable name to uppercase and uses that for the meta-variable. Sometimes, that’s not what you want—for example, the ‘--filename’ option explicitly sets ‘metavar="FILE"’, resulting in this automatically-generated option description: -f FILE, --filename=FILE This is important for more than just saving space, though: the manually written help text uses the meta-variable ‘FILE’ to clue the user in that there’s a connection between the semi-formal syntax ‘-f FILE’ and the informal semantic description “write output to FILE”. This is a simple but effective way to make your help text a lot clearer and more useful for end users. * options that have a default value can include ‘%default’ in the help string—*note optparse: c3. will replace it with *note str(): 330. of the option’s default value. If an option has no default value (or the default value is ‘None’), ‘%default’ expands to ‘none’. * Menu: * Grouping Options::  File: python.info, Node: Grouping Options, Up: Generating help 5.36.1.12 Grouping Options .......................... When dealing with many options, it is convenient to group these options for better help output. An *note OptionParser: 37a9. can contain several option groups, each of which can contain several options. An option group is obtained using the class *note OptionGroup: 37c8.: -- Class: optparse.OptionGroup (parser, title, description=None) where * parser is the *note OptionParser: 37a9. instance the group will be inserted in to * title is the group title * description, optional, is a long description of the group *note OptionGroup: 37c8. inherits from ‘OptionContainer’ (like *note OptionParser: 37a9.) and so the ‘add_option()’ method can be used to add an option to the group. Once all the options are declared, using the *note OptionParser: 37a9. method ‘add_option_group()’ the group is added to the previously defined parser. Continuing with the parser defined in the previous section, adding an *note OptionGroup: 37c8. to a parser is easy: group = OptionGroup(parser, "Dangerous Options", "Caution: use these options at your own risk. " "It is believed that some of them bite.") group.add_option("-g", action="store_true", help="Group option.") parser.add_option_group(group) This would result in the following help output: Usage: <yourscript> [options] arg1 arg2 Options: -h, --help show this help message and exit -v, --verbose make lots of noise [default] -q, --quiet be vewwy quiet (I'm hunting wabbits) -f FILE, --filename=FILE write output to FILE -m MODE, --mode=MODE interaction mode: novice, intermediate, or expert [default: intermediate] Dangerous Options: Caution: use these options at your own risk. It is believed that some of them bite. -g Group option. A bit more complete example might involve using more than one group: still extending the previous example: group = OptionGroup(parser, "Dangerous Options", "Caution: use these options at your own risk. " "It is believed that some of them bite.") group.add_option("-g", action="store_true", help="Group option.") parser.add_option_group(group) group = OptionGroup(parser, "Debug Options") group.add_option("-d", "--debug", action="store_true", help="Print debug information") group.add_option("-s", "--sql", action="store_true", help="Print all SQL statements executed") group.add_option("-e", action="store_true", help="Print every action done") parser.add_option_group(group) that results in the following output: Usage: <yourscript> [options] arg1 arg2 Options: -h, --help show this help message and exit -v, --verbose make lots of noise [default] -q, --quiet be vewwy quiet (I'm hunting wabbits) -f FILE, --filename=FILE write output to FILE -m MODE, --mode=MODE interaction mode: novice, intermediate, or expert [default: intermediate] Dangerous Options: Caution: use these options at your own risk. It is believed that some of them bite. -g Group option. Debug Options: -d, --debug Print debug information -s, --sql Print all SQL statements executed -e Print every action done Another interesting method, in particular when working programmatically with option groups is: -- Method: OptionParser.get_option_group (opt_str) Return the *note OptionGroup: 37c8. to which the short or long option string `opt_str' (e.g. ‘'-o'’ or ‘'--option'’) belongs. If there’s no such *note OptionGroup: 37c8, return ‘None’.  File: python.info, Node: Printing a version string, Next: How optparse handles errors, Prev: Generating help, Up: Tutorial<2> 5.36.1.13 Printing a version string ................................... Similar to the brief usage string, *note optparse: c3. can also print a version string for your program. You have to supply the string as the ‘version’ argument to OptionParser: parser = OptionParser(usage="%prog [-f] [-q]", version="%prog 1.0") ‘%prog’ is expanded just like it is in ‘usage’. Apart from that, ‘version’ can contain anything you like. When you supply it, *note optparse: c3. automatically adds a ‘--version’ option to your parser. If it encounters this option on the command line, it expands your ‘version’ string (by replacing ‘%prog’), prints it to stdout, and exits. For example, if your script is called ‘/usr/bin/foo’: $ /usr/bin/foo --version foo 1.0 The following two methods can be used to print and get the ‘version’ string: -- Method: OptionParser.print_version (file=None) Print the version message for the current program (‘self.version’) to `file' (default stdout). As with *note print_usage(): 37cd, any occurrence of ‘%prog’ in ‘self.version’ is replaced with the name of the current program. Does nothing if ‘self.version’ is empty or undefined. -- Method: OptionParser.get_version () Same as *note print_version(): 37cc. but returns the version string instead of printing it.  File: python.info, Node: How optparse handles errors, Next: Putting it all together, Prev: Printing a version string, Up: Tutorial<2> 5.36.1.14 How ‘optparse’ handles errors ....................................... There are two broad classes of errors that *note optparse: c3. has to worry about: programmer errors and user errors. Programmer errors are usually erroneous calls to *note OptionParser.add_option(): 1d4f, e.g. invalid option strings, unknown option attributes, missing option attributes, etc. These are dealt with in the usual way: raise an exception (either ‘optparse.OptionError’ or *note TypeError: 192.) and let the program crash. Handling user errors is much more important, since they are guaranteed to happen no matter how stable your code is. *note optparse: c3. can automatically detect some user errors, such as bad option arguments (passing ‘-n 4x’ where ‘-n’ takes an integer argument), missing arguments (‘-n’ at the end of the command line, where ‘-n’ takes an argument of any type). Also, you can call ‘OptionParser.error()’ to signal an application-defined error condition: (options, args) = parser.parse_args() ... if options.a and options.b: parser.error("options -a and -b are mutually exclusive") In either case, *note optparse: c3. handles the error the same way: it prints the program’s usage message and an error message to standard error and exits with error status 2. Consider the first example above, where the user passes ‘4x’ to an option that takes an integer: $ /usr/bin/foo -n 4x Usage: foo [options] foo: error: option -n: invalid integer value: '4x' Or, where the user fails to pass a value at all: $ /usr/bin/foo -n Usage: foo [options] foo: error: -n option requires an argument *note optparse: c3.-generated error messages take care always to mention the option involved in the error; be sure to do the same when calling ‘OptionParser.error()’ from your application code. If *note optparse: c3.’s default error-handling behaviour does not suit your needs, you’ll need to subclass OptionParser and override its ‘exit()’ and/or ‘error()’ methods.  File: python.info, Node: Putting it all together, Prev: How optparse handles errors, Up: Tutorial<2> 5.36.1.15 Putting it all together ................................. Here’s what *note optparse: c3.-based scripts usually look like: from optparse import OptionParser ... def main(): usage = "usage: %prog [options] arg" parser = OptionParser(usage) parser.add_option("-f", "--file", dest="filename", help="read data from FILENAME") parser.add_option("-v", "--verbose", action="store_true", dest="verbose") parser.add_option("-q", "--quiet", action="store_false", dest="verbose") ... (options, args) = parser.parse_args() if len(args) != 1: parser.error("incorrect number of arguments") if options.verbose: print("reading %s..." % options.filename) ... if __name__ == "__main__": main()  File: python.info, Node: Reference Guide, Next: Option Callbacks, Prev: Tutorial<2>, Up: optparse — Parser for command line options 5.36.1.16 Reference Guide ......................... * Menu: * Creating the parser:: * Populating the parser:: * Defining options:: * Option attributes:: * Standard option actions:: * Standard option types:: * Parsing arguments: Parsing arguments<2>. * Querying and manipulating your option parser:: * Conflicts between options:: * Cleanup: Cleanup<2>. * Other methods::  File: python.info, Node: Creating the parser, Next: Populating the parser, Up: Reference Guide 5.36.1.17 Creating the parser ............................. The first step in using *note optparse: c3. is to create an OptionParser instance. -- Class: optparse.OptionParser (...) The OptionParser constructor has no required arguments, but a number of optional keyword arguments. You should always pass them as keyword arguments, i.e. do not rely on the order in which the arguments are declared. ‘usage’ (default: ‘"%prog [options]"’) The usage summary to print when your program is run incorrectly or with a help option. When *note optparse: c3. prints the usage string, it expands ‘%prog’ to ‘os.path.basename(sys.argv[0])’ (or to ‘prog’ if you passed that keyword argument). To suppress a usage message, pass the special value ‘optparse.SUPPRESS_USAGE’. ‘option_list’ (default: ‘[]’) A list of Option objects to populate the parser with. The options in ‘option_list’ are added after any options in ‘standard_option_list’ (a class attribute that may be set by OptionParser subclasses), but before any version or help options. Deprecated; use *note add_option(): 1d4f. after creating the parser instead. ‘option_class’ (default: optparse.Option) Class to use when adding options to the parser in *note add_option(): 1d4f. ‘version’ (default: ‘None’) A version string to print when the user supplies a version option. If you supply a true value for ‘version’, *note optparse: c3. automatically adds a version option with the single option string ‘--version’. The substring ‘%prog’ is expanded the same as for ‘usage’. ‘conflict_handler’ (default: ‘"error"’) Specifies what to do when options with conflicting option strings are added to the parser; see section *note Conflicts between options: 37d6. ‘description’ (default: ‘None’) A paragraph of text giving a brief overview of your program. *note optparse: c3. reformats this paragraph to fit the current terminal width and prints it when the user requests help (after ‘usage’, but before the list of options). ‘formatter’ (default: a new ‘IndentedHelpFormatter’) An instance of optparse.HelpFormatter that will be used for printing help text. *note optparse: c3. provides two concrete classes for this purpose: IndentedHelpFormatter and TitledHelpFormatter. ‘add_help_option’ (default: ‘True’) If true, *note optparse: c3. will add a help option (with option strings ‘-h’ and ‘--help’) to the parser. ‘prog’ The string to use when expanding ‘%prog’ in ‘usage’ and ‘version’ instead of ‘os.path.basename(sys.argv[0])’. ‘epilog’ (default: ‘None’) A paragraph of help text to print after the option help.  File: python.info, Node: Populating the parser, Next: Defining options, Prev: Creating the parser, Up: Reference Guide 5.36.1.18 Populating the parser ............................... There are several ways to populate the parser with options. The preferred way is by using *note OptionParser.add_option(): 1d4f, as shown in section *note Tutorial: 37b2. ‘add_option()’ can be called in one of two ways: * pass it an Option instance (as returned by ‘make_option()’) * pass it any combination of positional and keyword arguments that are acceptable to ‘make_option()’ (i.e., to the Option constructor), and it will create the Option instance for you The other alternative is to pass a list of pre-constructed Option instances to the OptionParser constructor, as in: option_list = [ make_option("-f", "--filename", action="store", type="string", dest="filename"), make_option("-q", "--quiet", action="store_false", dest="verbose"), ] parser = OptionParser(option_list=option_list) (‘make_option()’ is a factory function for creating Option instances; currently it is an alias for the Option constructor. A future version of *note optparse: c3. may split Option into several classes, and ‘make_option()’ will pick the right class to instantiate. Do not instantiate Option directly.)  File: python.info, Node: Defining options, Next: Option attributes, Prev: Populating the parser, Up: Reference Guide 5.36.1.19 Defining options .......................... Each Option instance represents a set of synonymous command-line option strings, e.g. ‘-f’ and ‘--file’. You can specify any number of short or long option strings, but you must specify at least one overall option string. The canonical way to create an ‘Option’ instance is with the ‘add_option()’ method of *note OptionParser: 37a9. -- Method: OptionParser.add_option (option) -- Method: OptionParser.add_option (*opt_str, attr=value, ...) To define an option with only a short option string: parser.add_option("-f", attr=value, ...) And to define an option with only a long option string: parser.add_option("--foo", attr=value, ...) The keyword arguments define attributes of the new Option object. The most important option attribute is *note action: 37b4, and it largely determines which other attributes are relevant or required. If you pass irrelevant option attributes, or fail to pass required ones, *note optparse: c3. raises an ‘OptionError’ exception explaining your mistake. An option’s `action' determines what *note optparse: c3. does when it encounters this option on the command-line. The standard option actions hard-coded into *note optparse: c3. are: ‘"store"’ store this option’s argument (default) ‘"store_const"’ store a constant value ‘"store_true"’ store ‘True’ ‘"store_false"’ store ‘False’ ‘"append"’ append this option’s argument to a list ‘"append_const"’ append a constant value to a list ‘"count"’ increment a counter by one ‘"callback"’ call a specified function ‘"help"’ print a usage message including all options and the documentation for them (If you don’t supply an action, the default is ‘"store"’. For this action, you may also supply *note type: 37b5. and *note dest: 37b6. option attributes; see *note Standard option actions: 37db.) As you can see, most actions involve storing or updating a value somewhere. *note optparse: c3. always creates a special object for this, conventionally called ‘options’ (it happens to be an instance of ‘optparse.Values’). Option arguments (and various other values) are stored as attributes of this object, according to the *note dest: 37b6. (destination) option attribute. For example, when you call parser.parse_args() one of the first things *note optparse: c3. does is create the ‘options’ object: options = Values() If one of the options in this parser is defined with parser.add_option("-f", "--file", action="store", type="string", dest="filename") and the command-line being parsed includes any of the following: -ffoo -f foo --file=foo --file foo then *note optparse: c3, on seeing this option, will do the equivalent of options.filename = "foo" The *note type: 37b5. and *note dest: 37b6. option attributes are almost as important as *note action: 37b4, but *note action: 37b4. is the only one that makes sense for `all' options.  File: python.info, Node: Option attributes, Next: Standard option actions, Prev: Defining options, Up: Reference Guide 5.36.1.20 Option attributes ........................... The following option attributes may be passed as keyword arguments to *note OptionParser.add_option(): 1d4f. If you pass an option attribute that is not relevant to a particular option, or fail to pass a required option attribute, *note optparse: c3. raises ‘OptionError’. -- Attribute: Option.action (default: ‘"store"’) Determines *note optparse: c3.’s behaviour when this option is seen on the command line; the available options are documented *note here: 37db. -- Attribute: Option.type (default: ‘"string"’) The argument type expected by this option (e.g., ‘"string"’ or ‘"int"’); the available option types are documented *note here: 37de. -- Attribute: Option.dest (default: derived from option strings) If the option’s action implies writing or modifying a value somewhere, this tells *note optparse: c3. where to write it: *note dest: 37b6. names an attribute of the ‘options’ object that *note optparse: c3. builds as it parses the command line. -- Attribute: Option.default The value to use for this option’s destination if the option is not seen on the command line. See also *note OptionParser.set_defaults(): 37e0. -- Attribute: Option.nargs (default: 1) How many arguments of type *note type: 37b5. should be consumed when this option is seen. If > 1, *note optparse: c3. will store a tuple of values to *note dest: 37b6. -- Attribute: Option.const For actions that store a constant value, the constant value to store. -- Attribute: Option.choices For options of type ‘"choice"’, the list of strings the user may choose from. -- Attribute: Option.callback For options with action ‘"callback"’, the callable to call when this option is seen. See section *note Option Callbacks: 37c2. for detail on the arguments passed to the callable. -- Attribute: Option.callback_args -- Attribute: Option.callback_kwargs Additional positional and keyword arguments to pass to ‘callback’ after the four standard callback arguments. -- Attribute: Option.help Help text to print for this option when listing all available options after the user supplies a *note help: 37b7. option (such as ‘--help’). If no help text is supplied, the option will be listed without help text. To hide this option, use the special value ‘optparse.SUPPRESS_HELP’. -- Attribute: Option.metavar (default: derived from option strings) Stand-in for the option argument(s) to use when printing help text. See section *note Tutorial: 37b2. for an example.  File: python.info, Node: Standard option actions, Next: Standard option types, Prev: Option attributes, Up: Reference Guide 5.36.1.21 Standard option actions ................................. The various option actions all have slightly different requirements and effects. Most actions have several relevant option attributes which you may specify to guide *note optparse: c3.’s behaviour; a few have required attributes, which you must specify for any option using that action. * ‘"store"’ [relevant: *note type: 37b5, *note dest: 37b6, *note nargs: 37e1, *note choices: 37e3.] The option must be followed by an argument, which is converted to a value according to *note type: 37b5. and stored in *note dest: 37b6. If *note nargs: 37e1. > 1, multiple arguments will be consumed from the command line; all will be converted according to *note type: 37b5. and stored to *note dest: 37b6. as a tuple. See the *note Standard option types: 37de. section. If *note choices: 37e3. is supplied (a list or tuple of strings), the type defaults to ‘"choice"’. If *note type: 37b5. is not supplied, it defaults to ‘"string"’. If *note dest: 37b6. is not supplied, *note optparse: c3. derives a destination from the first long option string (e.g., ‘--foo-bar’ implies ‘foo_bar’). If there are no long option strings, *note optparse: c3. derives a destination from the first short option string (e.g., ‘-f’ implies ‘f’). Example: parser.add_option("-f") parser.add_option("-p", type="float", nargs=3, dest="point") As it parses the command line -f foo.txt -p 1 -3.5 4 -fbar.txt *note optparse: c3. will set options.f = "foo.txt" options.point = (1.0, -3.5, 4.0) options.f = "bar.txt" * ‘"store_const"’ [required: *note const: 37e2.; relevant: *note dest: 37b6.] The value *note const: 37e2. is stored in *note dest: 37b6. Example: parser.add_option("-q", "--quiet", action="store_const", const=0, dest="verbose") parser.add_option("-v", "--verbose", action="store_const", const=1, dest="verbose") parser.add_option("--noisy", action="store_const", const=2, dest="verbose") If ‘--noisy’ is seen, *note optparse: c3. will set options.verbose = 2 * ‘"store_true"’ [relevant: *note dest: 37b6.] A special case of ‘"store_const"’ that stores ‘True’ to *note dest: 37b6. * ‘"store_false"’ [relevant: *note dest: 37b6.] Like ‘"store_true"’, but stores ‘False’. Example: parser.add_option("--clobber", action="store_true", dest="clobber") parser.add_option("--no-clobber", action="store_false", dest="clobber") * ‘"append"’ [relevant: *note type: 37b5, *note dest: 37b6, *note nargs: 37e1, *note choices: 37e3.] The option must be followed by an argument, which is appended to the list in *note dest: 37b6. If no default value for *note dest: 37b6. is supplied, an empty list is automatically created when *note optparse: c3. first encounters this option on the command-line. If *note nargs: 37e1. > 1, multiple arguments are consumed, and a tuple of length *note nargs: 37e1. is appended to *note dest: 37b6. The defaults for *note type: 37b5. and *note dest: 37b6. are the same as for the ‘"store"’ action. Example: parser.add_option("-t", "--tracks", action="append", type="int") If ‘-t3’ is seen on the command-line, *note optparse: c3. does the equivalent of: options.tracks = [] options.tracks.append(int("3")) If, a little later on, ‘--tracks=4’ is seen, it does: options.tracks.append(int("4")) The ‘append’ action calls the ‘append’ method on the current value of the option. This means that any default value specified must have an ‘append’ method. It also means that if the default value is non-empty, the default elements will be present in the parsed value for the option, with any values from the command line appended after those default values: >>> parser.add_option("--files", action="append", default=['~/.mypkg/defaults']) >>> opts, args = parser.parse_args(['--files', 'overrides.mypkg']) >>> opts.files ['~/.mypkg/defaults', 'overrides.mypkg'] * ‘"append_const"’ [required: *note const: 37e2.; relevant: *note dest: 37b6.] Like ‘"store_const"’, but the value *note const: 37e2. is appended to *note dest: 37b6.; as with ‘"append"’, *note dest: 37b6. defaults to ‘None’, and an empty list is automatically created the first time the option is encountered. * ‘"count"’ [relevant: *note dest: 37b6.] Increment the integer stored at *note dest: 37b6. If no default value is supplied, *note dest: 37b6. is set to zero before being incremented the first time. Example: parser.add_option("-v", action="count", dest="verbosity") The first time ‘-v’ is seen on the command line, *note optparse: c3. does the equivalent of: options.verbosity = 0 options.verbosity += 1 Every subsequent occurrence of ‘-v’ results in options.verbosity += 1 * ‘"callback"’ [required: *note callback: 37e4.; relevant: *note type: 37b5, *note nargs: 37e1, *note callback_args: 37e5, *note callback_kwargs: 37e6.] Call the function specified by *note callback: 37e4, which is called as func(option, opt_str, value, parser, *args, **kwargs) See section *note Option Callbacks: 37c2. for more detail. * ‘"help"’ Prints a complete help message for all the options in the current option parser. The help message is constructed from the ‘usage’ string passed to OptionParser’s constructor and the *note help: 37b7. string passed to every option. If no *note help: 37b7. string is supplied for an option, it will still be listed in the help message. To omit an option entirely, use the special value ‘optparse.SUPPRESS_HELP’. *note optparse: c3. automatically adds a *note help: 37b7. option to all OptionParsers, so you do not normally need to create one. Example: from optparse import OptionParser, SUPPRESS_HELP # usually, a help option is added automatically, but that can # be suppressed using the add_help_option argument parser = OptionParser(add_help_option=False) parser.add_option("-h", "--help", action="help") parser.add_option("-v", action="store_true", dest="verbose", help="Be moderately verbose") parser.add_option("--file", dest="filename", help="Input file to read data from") parser.add_option("--secret", help=SUPPRESS_HELP) If *note optparse: c3. sees either ‘-h’ or ‘--help’ on the command line, it will print something like the following help message to stdout (assuming ‘sys.argv[0]’ is ‘"foo.py"’): Usage: foo.py [options] Options: -h, --help Show this help message and exit -v Be moderately verbose --file=FILENAME Input file to read data from After printing the help message, *note optparse: c3. terminates your process with ‘sys.exit(0)’. * ‘"version"’ Prints the version number supplied to the OptionParser to stdout and exits. The version number is actually formatted and printed by the ‘print_version()’ method of OptionParser. Generally only relevant if the ‘version’ argument is supplied to the OptionParser constructor. As with *note help: 37b7. options, you will rarely create ‘version’ options, since *note optparse: c3. automatically adds them when needed.  File: python.info, Node: Standard option types, Next: Parsing arguments<2>, Prev: Standard option actions, Up: Reference Guide 5.36.1.22 Standard option types ............................... *note optparse: c3. has five built-in option types: ‘"string"’, ‘"int"’, ‘"choice"’, ‘"float"’ and ‘"complex"’. If you need to add new option types, see section *note Extending optparse: 37ba. Arguments to string options are not checked or converted in any way: the text on the command line is stored in the destination (or passed to the callback) as-is. Integer arguments (type ‘"int"’) are parsed as follows: * if the number starts with ‘0x’, it is parsed as a hexadecimal number * if the number starts with ‘0’, it is parsed as an octal number * if the number starts with ‘0b’, it is parsed as a binary number * otherwise, the number is parsed as a decimal number The conversion is done by calling *note int(): 184. with the appropriate base (2, 8, 10, or 16). If this fails, so will *note optparse: c3, although with a more useful error message. ‘"float"’ and ‘"complex"’ option arguments are converted directly with *note float(): 187. and *note complex(): 189, with similar error-handling. ‘"choice"’ options are a subtype of ‘"string"’ options. The *note choices: 37e3. option attribute (a sequence of strings) defines the set of allowed option arguments. ‘optparse.check_choice()’ compares user-supplied option arguments against this master list and raises ‘OptionValueError’ if an invalid string is given.  File: python.info, Node: Parsing arguments<2>, Next: Querying and manipulating your option parser, Prev: Standard option types, Up: Reference Guide 5.36.1.23 Parsing arguments ........................... The whole point of creating and populating an OptionParser is to call its ‘parse_args()’ method: (options, args) = parser.parse_args(args=None, values=None) where the input parameters are ‘args’ the list of arguments to process (default: ‘sys.argv[1:]’) ‘values’ an ‘optparse.Values’ object to store option arguments in (default: a new instance of ‘Values’) – if you give an existing object, the option defaults will not be initialized on it and the return values are ‘options’ the same object that was passed in as ‘values’, or the optparse.Values instance created by *note optparse: c3. ‘args’ the leftover positional arguments after all options have been processed The most common usage is to supply neither keyword argument. If you supply ‘values’, it will be modified with repeated *note setattr(): 1285. calls (roughly one for every option argument stored to an option destination) and returned by ‘parse_args()’. If ‘parse_args()’ encounters any errors in the argument list, it calls the OptionParser’s ‘error()’ method with an appropriate end-user error message. This ultimately terminates your process with an exit status of 2 (the traditional Unix exit status for command-line errors).  File: python.info, Node: Querying and manipulating your option parser, Next: Conflicts between options, Prev: Parsing arguments<2>, Up: Reference Guide 5.36.1.24 Querying and manipulating your option parser ...................................................... The default behavior of the option parser can be customized slightly, and you can also poke around your option parser and see what’s there. OptionParser provides several methods to help you out: -- Method: OptionParser.disable_interspersed_args () Set parsing to stop on the first non-option. For example, if ‘-a’ and ‘-b’ are both simple options that take no arguments, *note optparse: c3. normally accepts this syntax: prog -a arg1 -b arg2 and treats it as equivalent to prog -a -b arg1 arg2 To disable this feature, call *note disable_interspersed_args(): 1d50. This restores traditional Unix syntax, where option parsing stops with the first non-option argument. Use this if you have a command processor which runs another command which has options of its own and you want to make sure these options don’t get confused. For example, each command might have a different set of options. -- Method: OptionParser.enable_interspersed_args () Set parsing to not stop on the first non-option, allowing interspersing switches with command arguments. This is the default behavior. -- Method: OptionParser.get_option (opt_str) Returns the Option instance with the option string `opt_str', or ‘None’ if no options have that option string. -- Method: OptionParser.has_option (opt_str) Return ‘True’ if the OptionParser has an option with option string `opt_str' (e.g., ‘-q’ or ‘--verbose’). -- Method: OptionParser.remove_option (opt_str) If the *note OptionParser: 37a9. has an option corresponding to `opt_str', that option is removed. If that option provided any other option strings, all of those option strings become invalid. If `opt_str' does not occur in any option belonging to this *note OptionParser: 37a9, raises *note ValueError: 1fb.  File: python.info, Node: Conflicts between options, Next: Cleanup<2>, Prev: Querying and manipulating your option parser, Up: Reference Guide 5.36.1.25 Conflicts between options ................................... If you’re not careful, it’s easy to define options with conflicting option strings: parser.add_option("-n", "--dry-run", ...) ... parser.add_option("-n", "--noisy", ...) (This is particularly true if you’ve defined your own OptionParser subclass with some standard options.) Every time you add an option, *note optparse: c3. checks for conflicts with existing options. If it finds any, it invokes the current conflict-handling mechanism. You can set the conflict-handling mechanism either in the constructor: parser = OptionParser(..., conflict_handler=handler) or with a separate call: parser.set_conflict_handler(handler) The available conflict handlers are: ‘"error"’ (default) assume option conflicts are a programming error and raise ‘OptionConflictError’ ‘"resolve"’ resolve option conflicts intelligently (see below) As an example, let’s define an *note OptionParser: 37a9. that resolves conflicts intelligently and add conflicting options to it: parser = OptionParser(conflict_handler="resolve") parser.add_option("-n", "--dry-run", ..., help="do no harm") parser.add_option("-n", "--noisy", ..., help="be noisy") At this point, *note optparse: c3. detects that a previously-added option is already using the ‘-n’ option string. Since ‘conflict_handler’ is ‘"resolve"’, it resolves the situation by removing ‘-n’ from the earlier option’s list of option strings. Now ‘--dry-run’ is the only way for the user to activate that option. If the user asks for help, the help message will reflect that: Options: --dry-run do no harm ... -n, --noisy be noisy It’s possible to whittle away the option strings for a previously-added option until there are none left, and the user has no way of invoking that option from the command-line. In that case, *note optparse: c3. removes that option completely, so it doesn’t show up in help text or anywhere else. Carrying on with our existing OptionParser: parser.add_option("--dry-run", ..., help="new dry-run option") At this point, the original ‘-n’/‘--dry-run’ option is no longer accessible, so *note optparse: c3. removes it, leaving this help text: Options: ... -n, --noisy be noisy --dry-run new dry-run option  File: python.info, Node: Cleanup<2>, Next: Other methods, Prev: Conflicts between options, Up: Reference Guide 5.36.1.26 Cleanup ................. OptionParser instances have several cyclic references. This should not be a problem for Python’s garbage collector, but you may wish to break the cyclic references explicitly by calling ‘destroy()’ on your OptionParser once you are done with it. This is particularly useful in long-running applications where large object graphs are reachable from your OptionParser.  File: python.info, Node: Other methods, Prev: Cleanup<2>, Up: Reference Guide 5.36.1.27 Other methods ....................... OptionParser supports several other public methods: -- Method: OptionParser.set_usage (usage) Set the usage string according to the rules described above for the ‘usage’ constructor keyword argument. Passing ‘None’ sets the default usage string; use ‘optparse.SUPPRESS_USAGE’ to suppress a usage message. -- Method: OptionParser.print_usage (file=None) Print the usage message for the current program (‘self.usage’) to `file' (default stdout). Any occurrence of the string ‘%prog’ in ‘self.usage’ is replaced with the name of the current program. Does nothing if ‘self.usage’ is empty or not defined. -- Method: OptionParser.get_usage () Same as *note print_usage(): 37cd. but returns the usage string instead of printing it. -- Method: OptionParser.set_defaults (dest=value, ...) Set default values for several option destinations at once. Using *note set_defaults(): 37e0. is the preferred way to set default values for options, since multiple options can share the same destination. For example, if several “mode” options all set the same destination, any one of them can set the default, and the last one wins: parser.add_option("--advanced", action="store_const", dest="mode", const="advanced", default="novice") # overridden below parser.add_option("--novice", action="store_const", dest="mode", const="novice", default="advanced") # overrides above setting To avoid this confusion, use *note set_defaults(): 37e0.: parser.set_defaults(mode="advanced") parser.add_option("--advanced", action="store_const", dest="mode", const="advanced") parser.add_option("--novice", action="store_const", dest="mode", const="novice")  File: python.info, Node: Option Callbacks, Next: Extending optparse, Prev: Reference Guide, Up: optparse — Parser for command line options 5.36.1.28 Option Callbacks .......................... When *note optparse: c3.’s built-in actions and types aren’t quite enough for your needs, you have two choices: extend *note optparse: c3. or define a callback option. Extending *note optparse: c3. is more general, but overkill for a lot of simple cases. Quite often a simple callback is all you need. There are two steps to defining a callback option: * define the option itself using the ‘"callback"’ action * write the callback; this is a function (or method) that takes at least four arguments, as described below * Menu: * Defining a callback option:: * How callbacks are called:: * Raising errors in a callback:: * Callback example 1; trivial callback: Callback example 1 trivial callback. * Callback example 2; check option order: Callback example 2 check option order. * Callback example 3; check option order (generalized): Callback example 3 check option order generalized. * Callback example 4; check arbitrary condition: Callback example 4 check arbitrary condition. * Callback example 5; fixed arguments: Callback example 5 fixed arguments. * Callback example 6; variable arguments: Callback example 6 variable arguments.  File: python.info, Node: Defining a callback option, Next: How callbacks are called, Up: Option Callbacks 5.36.1.29 Defining a callback option .................................... As always, the easiest way to define a callback option is by using the *note OptionParser.add_option(): 1d4f. method. Apart from *note action: 37b4, the only option attribute you must specify is ‘callback’, the function to call: parser.add_option("-c", action="callback", callback=my_callback) ‘callback’ is a function (or other callable object), so you must have already defined ‘my_callback()’ when you create this callback option. In this simple case, *note optparse: c3. doesn’t even know if ‘-c’ takes any arguments, which usually means that the option takes no arguments—the mere presence of ‘-c’ on the command-line is all it needs to know. In some circumstances, though, you might want your callback to consume an arbitrary number of command-line arguments. This is where writing callbacks gets tricky; it’s covered later in this section. *note optparse: c3. always passes four particular arguments to your callback, and it will only pass additional arguments if you specify them via *note callback_args: 37e5. and *note callback_kwargs: 37e6. Thus, the minimal callback function signature is: def my_callback(option, opt, value, parser): The four arguments to a callback are described below. There are several other option attributes that you can supply when you define a callback option: *note type: 37b5. has its usual meaning: as with the ‘"store"’ or ‘"append"’ actions, it instructs *note optparse: c3. to consume one argument and convert it to *note type: 37b5. Rather than storing the converted value(s) anywhere, though, *note optparse: c3. passes it to your callback function. *note nargs: 37e1. also has its usual meaning: if it is supplied and > 1, *note optparse: c3. will consume *note nargs: 37e1. arguments, each of which must be convertible to *note type: 37b5. It then passes a tuple of converted values to your callback. *note callback_args: 37e5. a tuple of extra positional arguments to pass to the callback *note callback_kwargs: 37e6. a dictionary of extra keyword arguments to pass to the callback  File: python.info, Node: How callbacks are called, Next: Raising errors in a callback, Prev: Defining a callback option, Up: Option Callbacks 5.36.1.30 How callbacks are called .................................. All callbacks are called as follows: func(option, opt_str, value, parser, *args, **kwargs) where ‘option’ is the Option instance that’s calling the callback ‘opt_str’ is the option string seen on the command-line that’s triggering the callback. (If an abbreviated long option was used, ‘opt_str’ will be the full, canonical option string—e.g. if the user puts ‘--foo’ on the command-line as an abbreviation for ‘--foobar’, then ‘opt_str’ will be ‘"--foobar"’.) ‘value’ is the argument to this option seen on the command-line. *note optparse: c3. will only expect an argument if *note type: 37b5. is set; the type of ‘value’ will be the type implied by the option’s type. If *note type: 37b5. for this option is ‘None’ (no argument expected), then ‘value’ will be ‘None’. If *note nargs: 37e1. > 1, ‘value’ will be a tuple of values of the appropriate type. ‘parser’ is the OptionParser instance driving the whole thing, mainly useful because you can access some other interesting data through its instance attributes: ‘parser.largs’ the current list of leftover arguments, ie. arguments that have been consumed but are neither options nor option arguments. Feel free to modify ‘parser.largs’, e.g. by adding more arguments to it. (This list will become ‘args’, the second return value of ‘parse_args()’.) ‘parser.rargs’ the current list of remaining arguments, ie. with ‘opt_str’ and ‘value’ (if applicable) removed, and only the arguments following them still there. Feel free to modify ‘parser.rargs’, e.g. by consuming more arguments. ‘parser.values’ the object where option values are by default stored (an instance of optparse.OptionValues). This lets callbacks use the same mechanism as the rest of *note optparse: c3. for storing option values; you don’t need to mess around with globals or closures. You can also access or modify the value(s) of any options already encountered on the command-line. ‘args’ is a tuple of arbitrary positional arguments supplied via the *note callback_args: 37e5. option attribute. ‘kwargs’ is a dictionary of arbitrary keyword arguments supplied via *note callback_kwargs: 37e6.  File: python.info, Node: Raising errors in a callback, Next: Callback example 1 trivial callback, Prev: How callbacks are called, Up: Option Callbacks 5.36.1.31 Raising errors in a callback ...................................... The callback function should raise ‘OptionValueError’ if there are any problems with the option or its argument(s). *note optparse: c3. catches this and terminates the program, printing the error message you supply to stderr. Your message should be clear, concise, accurate, and mention the option at fault. Otherwise, the user will have a hard time figuring out what they did wrong.  File: python.info, Node: Callback example 1 trivial callback, Next: Callback example 2 check option order, Prev: Raising errors in a callback, Up: Option Callbacks 5.36.1.32 Callback example 1: trivial callback .............................................. Here’s an example of a callback option that takes no arguments, and simply records that the option was seen: def record_foo_seen(option, opt_str, value, parser): parser.values.saw_foo = True parser.add_option("--foo", action="callback", callback=record_foo_seen) Of course, you could do that with the ‘"store_true"’ action.  File: python.info, Node: Callback example 2 check option order, Next: Callback example 3 check option order generalized, Prev: Callback example 1 trivial callback, Up: Option Callbacks 5.36.1.33 Callback example 2: check option order ................................................ Here’s a slightly more interesting example: record the fact that ‘-a’ is seen, but blow up if it comes after ‘-b’ in the command-line. def check_order(option, opt_str, value, parser): if parser.values.b: raise OptionValueError("can't use -a after -b") parser.values.a = 1 ... parser.add_option("-a", action="callback", callback=check_order) parser.add_option("-b", action="store_true", dest="b")  File: python.info, Node: Callback example 3 check option order generalized, Next: Callback example 4 check arbitrary condition, Prev: Callback example 2 check option order, Up: Option Callbacks 5.36.1.34 Callback example 3: check option order (generalized) .............................................................. If you want to re-use this callback for several similar options (set a flag, but blow up if ‘-b’ has already been seen), it needs a bit of work: the error message and the flag that it sets must be generalized. def check_order(option, opt_str, value, parser): if parser.values.b: raise OptionValueError("can't use %s after -b" % opt_str) setattr(parser.values, option.dest, 1) ... parser.add_option("-a", action="callback", callback=check_order, dest='a') parser.add_option("-b", action="store_true", dest="b") parser.add_option("-c", action="callback", callback=check_order, dest='c')  File: python.info, Node: Callback example 4 check arbitrary condition, Next: Callback example 5 fixed arguments, Prev: Callback example 3 check option order generalized, Up: Option Callbacks 5.36.1.35 Callback example 4: check arbitrary condition ....................................................... Of course, you could put any condition in there—you’re not limited to checking the values of already-defined options. For example, if you have options that should not be called when the moon is full, all you have to do is this: def check_moon(option, opt_str, value, parser): if is_moon_full(): raise OptionValueError("%s option invalid when moon is full" % opt_str) setattr(parser.values, option.dest, 1) ... parser.add_option("--foo", action="callback", callback=check_moon, dest="foo") (The definition of ‘is_moon_full()’ is left as an exercise for the reader.)  File: python.info, Node: Callback example 5 fixed arguments, Next: Callback example 6 variable arguments, Prev: Callback example 4 check arbitrary condition, Up: Option Callbacks 5.36.1.36 Callback example 5: fixed arguments ............................................. Things get slightly more interesting when you define callback options that take a fixed number of arguments. Specifying that a callback option takes arguments is similar to defining a ‘"store"’ or ‘"append"’ option: if you define *note type: 37b5, then the option takes one argument that must be convertible to that type; if you further define *note nargs: 37e1, then the option takes *note nargs: 37e1. arguments. Here’s an example that just emulates the standard ‘"store"’ action: def store_value(option, opt_str, value, parser): setattr(parser.values, option.dest, value) ... parser.add_option("--foo", action="callback", callback=store_value, type="int", nargs=3, dest="foo") Note that *note optparse: c3. takes care of consuming 3 arguments and converting them to integers for you; all you have to do is store them. (Or whatever; obviously you don’t need a callback for this example.)  File: python.info, Node: Callback example 6 variable arguments, Prev: Callback example 5 fixed arguments, Up: Option Callbacks 5.36.1.37 Callback example 6: variable arguments ................................................ Things get hairy when you want an option to take a variable number of arguments. For this case, you must write a callback, as *note optparse: c3. doesn’t provide any built-in capabilities for it. And you have to deal with certain intricacies of conventional Unix command-line parsing that *note optparse: c3. normally handles for you. In particular, callbacks should implement the conventional rules for bare ‘--’ and ‘-’ arguments: * either ‘--’ or ‘-’ can be option arguments * bare ‘--’ (if not the argument to some option): halt command-line processing and discard the ‘--’ * bare ‘-’ (if not the argument to some option): halt command-line processing but keep the ‘-’ (append it to ‘parser.largs’) If you want an option that takes a variable number of arguments, there are several subtle, tricky issues to worry about. The exact implementation you choose will be based on which trade-offs you’re willing to make for your application (which is why *note optparse: c3. doesn’t support this sort of thing directly). Nevertheless, here’s a stab at a callback for an option with variable arguments: def vararg_callback(option, opt_str, value, parser): assert value is None value = [] def floatable(str): try: float(str) return True except ValueError: return False for arg in parser.rargs: # stop on --foo like options if arg[:2] == "--" and len(arg) > 2: break # stop on -a, but not on -3 or -3.0 if arg[:1] == "-" and len(arg) > 1 and not floatable(arg): break value.append(arg) del parser.rargs[:len(value)] setattr(parser.values, option.dest, value) ... parser.add_option("-c", "--callback", dest="vararg_attr", action="callback", callback=vararg_callback)  File: python.info, Node: Extending optparse, Prev: Option Callbacks, Up: optparse — Parser for command line options 5.36.1.38 Extending ‘optparse’ .............................. Since the two major controlling factors in how *note optparse: c3. interprets command-line options are the action and type of each option, the most likely direction of extension is to add new actions and new types. * Menu: * Adding new types:: * Adding new actions::  File: python.info, Node: Adding new types, Next: Adding new actions, Up: Extending optparse 5.36.1.39 Adding new types .......................... To add new types, you need to define your own subclass of *note optparse: c3.’s ‘Option’ class. This class has a couple of attributes that define *note optparse: c3.’s types: *note TYPES: 380f. and *note TYPE_CHECKER: 3810. -- Attribute: Option.TYPES A tuple of type names; in your subclass, simply define a new tuple *note TYPES: 380f. that builds on the standard one. -- Attribute: Option.TYPE_CHECKER A dictionary mapping type names to type-checking functions. A type-checking function has the following signature: def check_mytype(option, opt, value) where ‘option’ is an ‘Option’ instance, ‘opt’ is an option string (e.g., ‘-f’), and ‘value’ is the string from the command line that must be checked and converted to your desired type. ‘check_mytype()’ should return an object of the hypothetical type ‘mytype’. The value returned by a type-checking function will wind up in the OptionValues instance returned by ‘OptionParser.parse_args()’, or be passed to a callback as the ‘value’ parameter. Your type-checking function should raise ‘OptionValueError’ if it encounters any problems. ‘OptionValueError’ takes a single string argument, which is passed as-is to *note OptionParser: 37a9.’s ‘error()’ method, which in turn prepends the program name and the string ‘"error:"’ and prints everything to stderr before terminating the process. Here’s a silly example that demonstrates adding a ‘"complex"’ option type to parse Python-style complex numbers on the command line. (This is even sillier than it used to be, because *note optparse: c3. 1.3 added built-in support for complex numbers, but never mind.) First, the necessary imports: from copy import copy from optparse import Option, OptionValueError You need to define your type-checker first, since it’s referred to later (in the *note TYPE_CHECKER: 3810. class attribute of your Option subclass): def check_complex(option, opt, value): try: return complex(value) except ValueError: raise OptionValueError( "option %s: invalid complex value: %r" % (opt, value)) Finally, the Option subclass: class MyOption (Option): TYPES = Option.TYPES + ("complex",) TYPE_CHECKER = copy(Option.TYPE_CHECKER) TYPE_CHECKER["complex"] = check_complex (If we didn’t make a *note copy(): 26. of *note Option.TYPE_CHECKER: 3810, we would end up modifying the *note TYPE_CHECKER: 3810. attribute of *note optparse: c3.’s Option class. This being Python, nothing stops you from doing that except good manners and common sense.) That’s it! Now you can write a script that uses the new option type just like any other *note optparse: c3.-based script, except you have to instruct your OptionParser to use MyOption instead of Option: parser = OptionParser(option_class=MyOption) parser.add_option("-c", type="complex") Alternately, you can build your own option list and pass it to OptionParser; if you don’t use ‘add_option()’ in the above way, you don’t need to tell OptionParser which option class to use: option_list = [MyOption("-c", action="store", type="complex", dest="c")] parser = OptionParser(option_list=option_list)  File: python.info, Node: Adding new actions, Prev: Adding new types, Up: Extending optparse 5.36.1.40 Adding new actions ............................ Adding new actions is a bit trickier, because you have to understand that *note optparse: c3. has a couple of classifications for actions: “store” actions actions that result in *note optparse: c3. storing a value to an attribute of the current OptionValues instance; these options require a *note dest: 37b6. attribute to be supplied to the Option constructor. “typed” actions actions that take a value from the command line and expect it to be of a certain type; or rather, a string that can be converted to a certain type. These options require a *note type: 37b5. attribute to the Option constructor. These are overlapping sets: some default “store” actions are ‘"store"’, ‘"store_const"’, ‘"append"’, and ‘"count"’, while the default “typed” actions are ‘"store"’, ‘"append"’, and ‘"callback"’. When you add an action, you need to categorize it by listing it in at least one of the following class attributes of Option (all are lists of strings): -- Attribute: Option.ACTIONS All actions must be listed in ACTIONS. -- Attribute: Option.STORE_ACTIONS “store” actions are additionally listed here. -- Attribute: Option.TYPED_ACTIONS “typed” actions are additionally listed here. -- Attribute: Option.ALWAYS_TYPED_ACTIONS Actions that always take a type (i.e. whose options always take a value) are additionally listed here. The only effect of this is that *note optparse: c3. assigns the default type, ‘"string"’, to options with no explicit type whose action is listed in *note ALWAYS_TYPED_ACTIONS: 3816. In order to actually implement your new action, you must override Option’s ‘take_action()’ method and add a case that recognizes your action. For example, let’s add an ‘"extend"’ action. This is similar to the standard ‘"append"’ action, but instead of taking a single value from the command-line and appending it to an existing list, ‘"extend"’ will take multiple values in a single comma-delimited string, and extend an existing list with them. That is, if ‘--names’ is an ‘"extend"’ option of type ‘"string"’, the command line --names=foo,bar --names blah --names ding,dong would result in a list ["foo", "bar", "blah", "ding", "dong"] Again we define a subclass of Option: class MyOption(Option): ACTIONS = Option.ACTIONS + ("extend",) STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",) TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",) ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",) def take_action(self, action, dest, opt, value, values, parser): if action == "extend": lvalue = value.split(",") values.ensure_value(dest, []).extend(lvalue) else: Option.take_action( self, action, dest, opt, value, values, parser) Features of note: * ‘"extend"’ both expects a value on the command-line and stores that value somewhere, so it goes in both *note STORE_ACTIONS: 3814. and *note TYPED_ACTIONS: 3815. * to ensure that *note optparse: c3. assigns the default type of ‘"string"’ to ‘"extend"’ actions, we put the ‘"extend"’ action in *note ALWAYS_TYPED_ACTIONS: 3816. as well. * ‘MyOption.take_action()’ implements just this one new action, and passes control back to ‘Option.take_action()’ for the standard *note optparse: c3. actions. * ‘values’ is an instance of the optparse_parser.Values class, which provides the very useful ‘ensure_value()’ method. ‘ensure_value()’ is essentially *note getattr(): 448. with a safety valve; it is called as values.ensure_value(attr, value) If the ‘attr’ attribute of ‘values’ doesn’t exist or is ‘None’, then ensure_value() first sets it to ‘value’, and then returns ‘value. This is very handy for actions like ‘"extend"’, ‘"append"’, and ‘"count"’, all of which accumulate data in a variable and expect that variable to be of a certain type (a list for the first two, an integer for the latter). Using ‘ensure_value()’ means that scripts using your action don’t have to worry about setting a default value for the option destinations in question; they can just leave the default as ‘None’ and ‘ensure_value()’ will take care of getting it right when it’s needed.  File: python.info, Node: imp — Access the import internals, Prev: optparse — Parser for command line options, Up: Superseded Modules 5.36.2 ‘imp’ — Access the import internals ------------------------------------------ `Source code:' Lib/imp.py(1) Deprecated since version 3.4: The *note imp: 9a. module is deprecated in favor of *note importlib: 9b. __________________________________________________________________ This module provides an interface to the mechanisms used to implement the *note import: c1d. statement. It defines the following constants and functions: -- Function: imp.get_magic () Return the magic string value used to recognize byte-compiled code files (‘.pyc’ files). (This value may be different for each Python version.) Deprecated since version 3.4: Use *note importlib.util.MAGIC_NUMBER: 862. instead. -- Function: imp.get_suffixes () Return a list of 3-element tuples, each describing a particular type of module. Each triple has the form ‘(suffix, mode, type)’, where `suffix' is a string to be appended to the module name to form the filename to search for, `mode' is the mode string to pass to the built-in *note open(): 4f0. function to open the file (this can be ‘'r'’ for text files or ‘'rb'’ for binary files), and `type' is the file type, which has one of the values *note PY_SOURCE: 381a, *note PY_COMPILED: 381b, or *note C_EXTENSION: 381c, described below. Deprecated since version 3.3: Use the constants defined on *note importlib.machinery: 9d. instead. -- Function: imp.find_module (name[, path]) Try to find the module `name'. If `path' is omitted or ‘None’, the list of directory names given by ‘sys.path’ is searched, but first a few special places are searched: the function tries to find a built-in module with the given name (*note C_BUILTIN: 381e.), then a frozen module (*note PY_FROZEN: 381f.), and on some systems some other places are looked in as well (on Windows, it looks in the registry which may point to a specific file). Otherwise, `path' must be a list of directory names; each directory is searched for files with any of the suffixes returned by *note get_suffixes(): 3819. above. Invalid names in the list are silently ignored (but all list items must be strings). If search is successful, the return value is a 3-element tuple ‘(file, pathname, description)’: `file' is an open *note file object: b42. positioned at the beginning, `pathname' is the pathname of the file found, and `description' is a 3-element tuple as contained in the list returned by *note get_suffixes(): 3819. describing the kind of module found. If the module is built-in or frozen then `file' and `pathname' are both ‘None’ and the `description' tuple contains empty strings for its suffix and mode; the module type is indicated as given in parentheses above. If the search is unsuccessful, *note ImportError: 334. is raised. Other exceptions indicate problems with the arguments or environment. If the module is a package, `file' is ‘None’, `pathname' is the package path and the last item in the `description' tuple is *note PKG_DIRECTORY: 3820. This function does not handle hierarchical module names (names containing dots). In order to find `P.M', that is, submodule `M' of package `P', use *note find_module(): 381d. and *note load_module(): 3821. to find and load package `P', and then use *note find_module(): 381d. with the `path' argument set to ‘P.__path__’. When `P' itself has a dotted name, apply this recipe recursively. Deprecated since version 3.3: Use *note importlib.util.find_spec(): 938. instead unless Python 3.3 compatibility is required, in which case use *note importlib.find_loader(): 937. For example usage of the former case, see the *note Examples: 34cf. section of the *note importlib: 9b. documentation. -- Function: imp.load_module (name, file, pathname, description) Load a module that was previously found by *note find_module(): 381d. (or by an otherwise conducted search yielding compatible results). This function does more than importing the module: if the module was already imported, it will reload the module! The `name' argument indicates the full module name (including the package name, if this is a submodule of a package). The `file' argument is an open file, and `pathname' is the corresponding file name; these can be ‘None’ and ‘''’, respectively, when the module is a package or not being loaded from a file. The `description' argument is a tuple, as would be returned by *note get_suffixes(): 3819, describing what kind of module must be loaded. If the load is successful, the return value is the module object; otherwise, an exception (usually *note ImportError: 334.) is raised. `Important:' the caller is responsible for closing the `file' argument, if it was not ‘None’, even when an exception is raised. This is best done using a *note try: d72. … *note finally: 182. statement. Deprecated since version 3.3: If previously used in conjunction with *note imp.find_module(): 381d. then consider using *note importlib.import_module(): b13, otherwise use the loader returned by the replacement you chose for *note imp.find_module(): 381d. If you called *note imp.load_module(): 3821. and related functions directly with file path arguments then use a combination of *note importlib.util.spec_from_file_location(): 559. and *note importlib.util.module_from_spec(): 6f0. See the *note Examples: 34cf. section of the *note importlib: 9b. documentation for details of the various approaches. -- Function: imp.new_module (name) Return a new empty module object called `name'. This object is `not' inserted in ‘sys.modules’. Deprecated since version 3.4: Use *note importlib.util.module_from_spec(): 6f0. instead. -- Function: imp.reload (module) Reload a previously imported `module'. The argument must be a module object, so it must have been successfully imported before. This is useful if you have edited the module source file using an external editor and want to try out the new version without leaving the Python interpreter. The return value is the module object (the same as the `module' argument). When ‘reload(module)’ is executed: * Python modules’ code is recompiled and the module-level code reexecuted, defining a new set of objects which are bound to names in the module’s dictionary. The ‘init’ function of extension modules is not called a second time. * As with all other objects in Python the old objects are only reclaimed after their reference counts drop to zero. * The names in the module namespace are updated to point to any new or changed objects. * Other references to the old objects (such as names external to the module) are not rebound to refer to the new objects and must be updated in each namespace where they occur if that is desired. There are a number of other caveats: When a module is reloaded, its dictionary (containing the module’s global variables) is retained. Redefinitions of names will override the old definitions, so this is generally not a problem. If the new version of a module does not define a name that was defined by the old version, the old definition remains. This feature can be used to the module’s advantage if it maintains a global table or cache of objects — with a *note try: d72. statement it can test for the table’s presence and skip its initialization if desired: try: cache except NameError: cache = {} It is legal though generally not very useful to reload built-in or dynamically loaded modules, except for *note sys: fd, *note __main__: 1. and *note builtins: 13. In many cases, however, extension modules are not designed to be initialized more than once, and may fail in arbitrary ways when reloaded. If a module imports objects from another module using *note from: c45. … *note import: c1d. …, calling *note reload(): c70. for the other module does not redefine the objects imported from it — one way around this is to re-execute the ‘from’ statement, another is to use ‘import’ and qualified names (`module'.*name*) instead. If a module instantiates instances of a class, reloading the module that defines the class does not affect the method definitions of the instances — they continue to use the old class definition. The same is true for derived classes. Changed in version 3.3: Relies on both ‘__name__’ and ‘__loader__’ being defined on the module being reloaded instead of just ‘__name__’. Deprecated since version 3.4: Use *note importlib.reload(): 399. instead. The following functions are conveniences for handling PEP 3147(2) byte-compiled file paths. New in version 3.2. -- Function: imp.cache_from_source (path, debug_override=None) Return the PEP 3147(3) path to the byte-compiled file associated with the source `path'. For example, if `path' is ‘/foo/bar/baz.py’ the return value would be ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ for Python 3.2. The ‘cpython-32’ string comes from the current magic tag (see *note get_tag(): 3824.; if ‘sys.implementation.cache_tag’ is not defined then *note NotImplementedError: 60e. will be raised). By passing in ‘True’ or ‘False’ for `debug_override' you can override the system’s value for ‘__debug__’, leading to optimized bytecode. `path' need not exist. Changed in version 3.3: If ‘sys.implementation.cache_tag’ is ‘None’, then *note NotImplementedError: 60e. is raised. Deprecated since version 3.4: Use *note importlib.util.cache_from_source(): 557. instead. Changed in version 3.5: The `debug_override' parameter no longer creates a ‘.pyo’ file. -- Function: imp.source_from_cache (path) Given the `path' to a PEP 3147(4) file name, return the associated source code file path. For example, if `path' is ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ the returned path would be ‘/foo/bar/baz.py’. `path' need not exist, however if it does not conform to PEP 3147(5) format, a *note ValueError: 1fb. is raised. If ‘sys.implementation.cache_tag’ is not defined, *note NotImplementedError: 60e. is raised. Changed in version 3.3: Raise *note NotImplementedError: 60e. when ‘sys.implementation.cache_tag’ is not defined. Deprecated since version 3.4: Use *note importlib.util.source_from_cache(): 558. instead. -- Function: imp.get_tag () Return the PEP 3147(6) magic tag string matching this version of Python’s magic number, as returned by *note get_magic(): 863. Deprecated since version 3.4: Use ‘sys.implementation.cache_tag’ directly starting in Python 3.3. The following functions help interact with the import system’s internal locking mechanism. Locking semantics of imports are an implementation detail which may vary from release to release. However, Python ensures that circular imports work without any deadlocks. -- Function: imp.lock_held () Return ‘True’ if the global import lock is currently held, else ‘False’. On platforms without threads, always return ‘False’. On platforms with threads, a thread executing an import first holds a global import lock, then sets up a per-module lock for the rest of the import. This blocks other threads from importing the same module until the original import completes, preventing other threads from seeing incomplete module objects constructed by the original thread. An exception is made for circular imports, which by construction have to expose an incomplete module object at some point. Changed in version 3.3: The locking scheme has changed to per-module locks for the most part. A global import lock is kept for some critical tasks, such as initializing the per-module locks. Deprecated since version 3.4. -- Function: imp.acquire_lock () Acquire the interpreter’s global import lock for the current thread. This lock should be used by import hooks to ensure thread-safety when importing modules. Once a thread has acquired the import lock, the same thread may acquire it again without blocking; the thread must release it once for each time it has acquired it. On platforms without threads, this function does nothing. Changed in version 3.3: The locking scheme has changed to per-module locks for the most part. A global import lock is kept for some critical tasks, such as initializing the per-module locks. Deprecated since version 3.4. -- Function: imp.release_lock () Release the interpreter’s global import lock. On platforms without threads, this function does nothing. Changed in version 3.3: The locking scheme has changed to per-module locks for the most part. A global import lock is kept for some critical tasks, such as initializing the per-module locks. Deprecated since version 3.4. The following constants with integer values, defined in this module, are used to indicate the search result of *note find_module(): 381d. -- Data: imp.PY_SOURCE The module was found as a source file. Deprecated since version 3.3. -- Data: imp.PY_COMPILED The module was found as a compiled code object file. Deprecated since version 3.3. -- Data: imp.C_EXTENSION The module was found as dynamically loadable shared library. Deprecated since version 3.3. -- Data: imp.PKG_DIRECTORY The module was found as a package directory. Deprecated since version 3.3. -- Data: imp.C_BUILTIN The module was found as a built-in module. Deprecated since version 3.3. -- Data: imp.PY_FROZEN The module was found as a frozen module. Deprecated since version 3.3. -- Class: imp.NullImporter (path_string) The *note NullImporter: 9bb. type is a PEP 302(7) import hook that handles non-directory path strings by failing to find any modules. Calling this type with an existing directory or empty string raises *note ImportError: 334. Otherwise, a *note NullImporter: 9bb. instance is returned. Instances have only one method: -- Method: find_module (fullname[, path]) This method always returns ‘None’, indicating that the requested module could not be found. Changed in version 3.3: ‘None’ is inserted into ‘sys.path_importer_cache’ instead of an instance of *note NullImporter: 9bb. Deprecated since version 3.4: Insert ‘None’ into ‘sys.path_importer_cache’ instead. * Menu: * Examples: Examples<33>. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/imp.py (2) https://www.python.org/dev/peps/pep-3147 (3) https://www.python.org/dev/peps/pep-3147 (4) https://www.python.org/dev/peps/pep-3147 (5) https://www.python.org/dev/peps/pep-3147 (6) https://www.python.org/dev/peps/pep-3147 (7) https://www.python.org/dev/peps/pep-0302  File: python.info, Node: Examples<33>, Up: imp — Access the import internals 5.36.2.1 Examples ................. The following function emulates what was the standard import statement up to Python 1.4 (no hierarchical module names). (This `implementation' wouldn’t work in that version, since *note find_module(): 381d. has been extended and *note load_module(): 3821. has been added in 1.4.) import imp import sys def __import__(name, globals=None, locals=None, fromlist=None): # Fast path: see if the module has already been imported. try: return sys.modules[name] except KeyError: pass # If any of the following calls raises an exception, # there's a problem we can't handle -- let the caller handle it. fp, pathname, description = imp.find_module(name) try: return imp.load_module(name, fp, pathname, description) finally: # Since we may exit via an exception, close fp explicitly. if fp: fp.close()  File: python.info, Node: Undocumented Modules, Prev: Superseded Modules, Up: The Python Standard Library 5.37 Undocumented Modules ========================= Here’s a quick listing of modules that are currently undocumented, but that should be documented. Feel free to contribute documentation for them! (Send via email to <docs@python.org>.) The idea and original contents for this chapter were taken from a posting by Fredrik Lundh; the specific contents of this chapter have been substantially revised. * Menu: * Platform specific modules::  File: python.info, Node: Platform specific modules, Up: Undocumented Modules 5.37.1 Platform specific modules -------------------------------- These modules are used to implement the *note os.path: c5. module, and are not documented beyond this mention. There’s little need to document these. ‘ntpath’ — Implementation of *note os.path: c5. on Win32 and Win64 platforms. ‘posixpath’ — Implementation of *note os.path: c5. on POSIX.  File: python.info, Node: Extending and Embedding the Python Interpreter, Next: Python/C API Reference Manual, Prev: The Python Standard Library, Up: Top 6 Extending and Embedding the Python Interpreter ************************************************ This document describes how to write modules in C or C++ to extend the Python interpreter with new modules. Those modules can not only define new functions but also new object types and their methods. The document also describes how to embed the Python interpreter in another application, for use as an extension language. Finally, it shows how to compile and link extension modules so that they can be loaded dynamically (at run time) into the interpreter, if the underlying operating system supports this feature. This document assumes basic knowledge about Python. For an informal introduction to the language, see *note The Python Tutorial: e8d. *note The Python Language Reference: e8f. gives a more formal definition of the language. *note The Python Standard Library: e8e. documents the existing object types, functions and modules (both built-in and written in Python) that give the language its wide application range. For a detailed description of the whole Python/C API, see the separate *note Python/C API Reference Manual: e91. * Menu: * Recommended third party tools:: * Creating extensions without third party tools:: * Embedding the CPython runtime in a larger application::  File: python.info, Node: Recommended third party tools, Next: Creating extensions without third party tools, Up: Extending and Embedding the Python Interpreter 6.1 Recommended third party tools ================================= This guide only covers the basic tools for creating extensions provided as part of this version of CPython. Third party tools like Cython(1), cffi(2), SWIG(3) and Numba(4) offer both simpler and more sophisticated approaches to creating C and C++ extensions for Python. See also ........ Python Packaging User Guide: Binary Extensions(5) The Python Packaging User Guide not only covers several available tools that simplify the creation of binary extensions, but also discusses the various reasons why creating an extension module may be desirable in the first place. ---------- Footnotes ---------- (1) http://cython.org/ (2) https://cffi.readthedocs.io (3) http://www.swig.org (4) https://numba.pydata.org/ (5) https://packaging.python.org/guides/packaging-binary-extensions/  File: python.info, Node: Creating extensions without third party tools, Next: Embedding the CPython runtime in a larger application, Prev: Recommended third party tools, Up: Extending and Embedding the Python Interpreter 6.2 Creating extensions without third party tools ================================================= This section of the guide covers creating C and C++ extensions without assistance from third party tools. It is intended primarily for creators of those tools, rather than being a recommended way to create your own C extensions. * Menu: * Extending Python with C or C++:: * Defining Extension Types; Tutorial: Defining Extension Types Tutorial. * Defining Extension Types; Assorted Topics: Defining Extension Types Assorted Topics. * Building C and C++ Extensions:: * Building C and C++ Extensions on Windows::  File: python.info, Node: Extending Python with C or C++, Next: Defining Extension Types Tutorial, Up: Creating extensions without third party tools 6.2.1 Extending Python with C or C++ ------------------------------------ It is quite easy to add new built-in modules to Python, if you know how to program in C. Such `extension modules' can do two things that can’t be done directly in Python: they can implement new built-in object types, and they can call C library functions and system calls. To support extensions, the Python API (Application Programmers Interface) defines a set of functions, macros and variables that provide access to most aspects of the Python run-time system. The Python API is incorporated in a C source file by including the header ‘"Python.h"’. The compilation of an extension module depends on its intended use as well as on your system setup; details are given in later chapters. Note: The C extension interface is specific to CPython, and extension modules do not work on other Python implementations. In many cases, it is possible to avoid writing C extensions and preserve portability to other implementations. For example, if your use case is calling C library functions or system calls, you should consider using the *note ctypes: 2b. module or the cffi(1) library rather than writing custom C code. These modules let you write Python code to interface with C code and are more portable between implementations of Python than writing and compiling a C extension module. * Menu: * A Simple Example:: * Intermezzo; Errors and Exceptions: Intermezzo Errors and Exceptions. * Back to the Example:: * The Module’s Method Table and Initialization Function:: * Compilation and Linkage:: * Calling Python Functions from C:: * Extracting Parameters in Extension Functions:: * Keyword Parameters for Extension Functions:: * Building Arbitrary Values:: * Reference Counts:: * Writing Extensions in C++:: * Providing a C API for an Extension Module:: ---------- Footnotes ---------- (1) https://cffi.readthedocs.io/  File: python.info, Node: A Simple Example, Next: Intermezzo Errors and Exceptions, Up: Extending Python with C or C++ 6.2.1.1 A Simple Example ........................ Let’s create an extension module called ‘spam’ (the favorite food of Monty Python fans…) and let’s say we want to create a Python interface to the C library function ‘system()’ (1). This function takes a null-terminated character string as argument and returns an integer. We want this function to be callable from Python as follows: >>> import spam >>> status = spam.system("ls -l") Begin by creating a file ‘spammodule.c’. (Historically, if a module is called ‘spam’, the C file containing its implementation is called ‘spammodule.c’; if the module name is very long, like ‘spammify’, the module name can be just ‘spammify.c’.) The first two lines of our file can be: #define PY_SSIZE_T_CLEAN #include <Python.h> which pulls in the Python API (you can add a comment describing the purpose of the module and a copyright notice if you like). Note: Since Python may define some pre-processor definitions which affect the standard headers on some systems, you `must' include ‘Python.h’ before any standard headers are included. It is recommended to always define ‘PY_SSIZE_T_CLEAN’ before including ‘Python.h’. See *note Extracting Parameters in Extension Functions: 3839. for a description of this macro. All user-visible symbols defined by ‘Python.h’ have a prefix of ‘Py’ or ‘PY’, except those defined in standard header files. For convenience, and since they are used extensively by the Python interpreter, ‘"Python.h"’ includes a few standard header files: ‘<stdio.h>’, ‘<string.h>’, ‘<errno.h>’, and ‘<stdlib.h>’. If the latter header file does not exist on your system, it declares the functions ‘malloc()’, ‘free()’ and ‘realloc()’ directly. The next thing we add to our module file is the C function that will be called when the Python expression ‘spam.system(string)’ is evaluated (we’ll see shortly how it ends up being called): static PyObject * spam_system(PyObject *self, PyObject *args) { const char *command; int sts; if (!PyArg_ParseTuple(args, "s", &command)) return NULL; sts = system(command); return PyLong_FromLong(sts); } There is a straightforward translation from the argument list in Python (for example, the single expression ‘"ls -l"’) to the arguments passed to the C function. The C function always has two arguments, conventionally named `self' and `args'. The `self' argument points to the module object for module-level functions; for a method it would point to the object instance. The `args' argument will be a pointer to a Python tuple object containing the arguments. Each item of the tuple corresponds to an argument in the call’s argument list. The arguments are Python objects — in order to do anything with them in our C function we have to convert them to C values. The function *note PyArg_ParseTuple(): 26a. in the Python API checks the argument types and converts them to C values. It uses a template string to determine the required types of the arguments as well as the types of the C variables into which to store the converted values. More about this later. *note PyArg_ParseTuple(): 26a. returns true (nonzero) if all arguments have the right type and its components have been stored in the variables whose addresses are passed. It returns false (zero) if an invalid argument list was passed. In the latter case it also raises an appropriate exception so the calling function can return ‘NULL’ immediately (as we saw in the example). ---------- Footnotes ---------- (1) (1) An interface for this function already exists in the standard module *note os: c4. — it was chosen as a simple and straightforward example.  File: python.info, Node: Intermezzo Errors and Exceptions, Next: Back to the Example, Prev: A Simple Example, Up: Extending Python with C or C++ 6.2.1.2 Intermezzo: Errors and Exceptions ......................................... An important convention throughout the Python interpreter is the following: when a function fails, it should set an exception condition and return an error value (usually a ‘NULL’ pointer). Exceptions are stored in a static global variable inside the interpreter; if this variable is ‘NULL’ no exception has occurred. A second global variable stores the “associated value” of the exception (the second argument to *note raise: c42.). A third variable contains the stack traceback in case the error originated in Python code. These three variables are the C equivalents of the result in Python of *note sys.exc_info(): c5f. (see the section on module *note sys: fd. in the Python Library Reference). It is important to know about them to understand how errors are passed around. The Python API defines a number of functions to set various types of exceptions. The most common one is *note PyErr_SetString(): 383c. Its arguments are an exception object and a C string. The exception object is usually a predefined object like ‘PyExc_ZeroDivisionError’. The C string indicates the cause of the error and is converted to a Python string object and stored as the “associated value” of the exception. Another useful function is *note PyErr_SetFromErrno(): 383d, which only takes an exception argument and constructs the associated value by inspection of the global variable ‘errno’. The most general function is *note PyErr_SetObject(): 383e, which takes two object arguments, the exception and its associated value. You don’t need to *note Py_INCREF(): 265. the objects passed to any of these functions. You can test non-destructively whether an exception has been set with *note PyErr_Occurred(): 383f. This returns the current exception object, or ‘NULL’ if no exception has occurred. You normally don’t need to call *note PyErr_Occurred(): 383f. to see whether an error occurred in a function call, since you should be able to tell from the return value. When a function `f' that calls another function `g' detects that the latter fails, `f' should itself return an error value (usually ‘NULL’ or ‘-1’). It should `not' call one of the ‘PyErr_*()’ functions — one has already been called by `g'. `f'’s caller is then supposed to also return an error indication to `its' caller, again `without' calling ‘PyErr_*()’, and so on — the most detailed cause of the error was already reported by the function that first detected it. Once the error reaches the Python interpreter’s main loop, this aborts the currently executing Python code and tries to find an exception handler specified by the Python programmer. (There are situations where a module can actually give a more detailed error message by calling another ‘PyErr_*()’ function, and in such cases it is fine to do so. As a general rule, however, this is not necessary, and can cause information about the cause of the error to be lost: most operations can fail for a variety of reasons.) To ignore an exception set by a function call that failed, the exception condition must be cleared explicitly by calling *note PyErr_Clear(): 96b. The only time C code should call *note PyErr_Clear(): 96b. is if it doesn’t want to pass the error on to the interpreter but wants to handle it completely by itself (possibly by trying something else, or pretending nothing went wrong). Every failing ‘malloc()’ call must be turned into an exception — the direct caller of ‘malloc()’ (or ‘realloc()’) must call *note PyErr_NoMemory(): 3840. and return a failure indicator itself. All the object-creating functions (for example, *note PyLong_FromLong(): 3841.) already do this, so this note is only relevant to those who call ‘malloc()’ directly. Also note that, with the important exception of *note PyArg_ParseTuple(): 26a. and friends, functions that return an integer status usually return a positive value or zero for success and ‘-1’ for failure, like Unix system calls. Finally, be careful to clean up garbage (by making *note Py_XDECREF(): 268. or *note Py_DECREF(): 266. calls for objects you have already created) when you return an error indicator! The choice of which exception to raise is entirely yours. There are predeclared C objects corresponding to all built-in Python exceptions, such as ‘PyExc_ZeroDivisionError’, which you can use directly. Of course, you should choose exceptions wisely — don’t use ‘PyExc_TypeError’ to mean that a file couldn’t be opened (that should probably be ‘PyExc_IOError’). If something’s wrong with the argument list, the *note PyArg_ParseTuple(): 26a. function usually raises ‘PyExc_TypeError’. If you have an argument whose value must be in a particular range or must satisfy other conditions, ‘PyExc_ValueError’ is appropriate. You can also define a new exception that is unique to your module. For this, you usually declare a static object variable at the beginning of your file: static PyObject *SpamError; and initialize it in your module’s initialization function (‘PyInit_spam()’) with an exception object: PyMODINIT_FUNC PyInit_spam(void) { PyObject *m; m = PyModule_Create(&spammodule); if (m == NULL) return NULL; SpamError = PyErr_NewException("spam.error", NULL, NULL); Py_XINCREF(SpamError); if (PyModule_AddObject(m, "error", SpamError) < 0) { Py_XDECREF(SpamError); Py_CLEAR(SpamError); Py_DECREF(m); return NULL; } return m; } Note that the Python name for the exception object is ‘spam.error’. The *note PyErr_NewException(): c00. function may create a class with the base class being *note Exception: 1a9. (unless another class is passed in instead of ‘NULL’), described in *note Built-in Exceptions: f43. Note also that the ‘SpamError’ variable retains a reference to the newly created exception class; this is intentional! Since the exception could be removed from the module by external code, an owned reference to the class is needed to ensure that it will not be discarded, causing ‘SpamError’ to become a dangling pointer. Should it become a dangling pointer, C code which raises the exception could cause a core dump or other unintended side effects. We discuss the use of ‘PyMODINIT_FUNC’ as a function return type later in this sample. The ‘spam.error’ exception can be raised in your extension module using a call to *note PyErr_SetString(): 383c. as shown below: static PyObject * spam_system(PyObject *self, PyObject *args) { const char *command; int sts; if (!PyArg_ParseTuple(args, "s", &command)) return NULL; sts = system(command); if (sts < 0) { PyErr_SetString(SpamError, "System command failed"); return NULL; } return PyLong_FromLong(sts); }  File: python.info, Node: Back to the Example, Next: The Module’s Method Table and Initialization Function, Prev: Intermezzo Errors and Exceptions, Up: Extending Python with C or C++ 6.2.1.3 Back to the Example ........................... Going back to our example function, you should now be able to understand this statement: if (!PyArg_ParseTuple(args, "s", &command)) return NULL; It returns ‘NULL’ (the error indicator for functions returning object pointers) if an error is detected in the argument list, relying on the exception set by *note PyArg_ParseTuple(): 26a. Otherwise the string value of the argument has been copied to the local variable ‘command’. This is a pointer assignment and you are not supposed to modify the string to which it points (so in Standard C, the variable ‘command’ should properly be declared as ‘const char *command’). The next statement is a call to the Unix function ‘system()’, passing it the string we just got from *note PyArg_ParseTuple(): 26a.: sts = system(command); Our ‘spam.system()’ function must return the value of ‘sts’ as a Python object. This is done using the function *note PyLong_FromLong(): 3841. return PyLong_FromLong(sts); In this case, it will return an integer object. (Yes, even integers are objects on the heap in Python!) If you have a C function that returns no useful argument (a function returning ‘void’), the corresponding Python function must return ‘None’. You need this idiom to do so (which is implemented by the *note Py_RETURN_NONE: dd6. macro): Py_INCREF(Py_None); return Py_None; *note Py_None: 3844. is the C name for the special Python object ‘None’. It is a genuine Python object rather than a ‘NULL’ pointer, which means “error” in most contexts, as we have seen.  File: python.info, Node: The Module’s Method Table and Initialization Function, Next: Compilation and Linkage, Prev: Back to the Example, Up: Extending Python with C or C++ 6.2.1.4 The Module’s Method Table and Initialization Function ............................................................. I promised to show how ‘spam_system()’ is called from Python programs. First, we need to list its name and address in a “method table”: static PyMethodDef SpamMethods[] = { ... {"system", spam_system, METH_VARARGS, "Execute a shell command."}, ... {NULL, NULL, 0, NULL} /* Sentinel */ }; Note the third entry (‘METH_VARARGS’). This is a flag telling the interpreter the calling convention to be used for the C function. It should normally always be ‘METH_VARARGS’ or ‘METH_VARARGS | METH_KEYWORDS’; a value of ‘0’ means that an obsolete variant of *note PyArg_ParseTuple(): 26a. is used. When using only ‘METH_VARARGS’, the function should expect the Python-level parameters to be passed in as a tuple acceptable for parsing via *note PyArg_ParseTuple(): 26a.; more information on this function is provided below. The ‘METH_KEYWORDS’ bit may be set in the third field if keyword arguments should be passed to the function. In this case, the C function should accept a third ‘PyObject *’ parameter which will be a dictionary of keywords. Use *note PyArg_ParseTupleAndKeywords(): 5ca. to parse the arguments to such a function. The method table must be referenced in the module definition structure: static struct PyModuleDef spammodule = { PyModuleDef_HEAD_INIT, "spam", /* name of module */ spam_doc, /* module documentation, may be NULL */ -1, /* size of per-interpreter state of the module, or -1 if the module keeps state in global variables. */ SpamMethods }; This structure, in turn, must be passed to the interpreter in the module’s initialization function. The initialization function must be named ‘PyInit_name()’, where `name' is the name of the module, and should be the only non-‘static’ item defined in the module file: PyMODINIT_FUNC PyInit_spam(void) { return PyModule_Create(&spammodule); } Note that PyMODINIT_FUNC declares the function as ‘PyObject *’ return type, declares any special linkage declarations required by the platform, and for C++ declares the function as ‘extern "C"’. When the Python program imports module ‘spam’ for the first time, ‘PyInit_spam()’ is called. (See below for comments about embedding Python.) It calls *note PyModule_Create(): 3847, which returns a module object, and inserts built-in function objects into the newly created module based upon the table (an array of *note PyMethodDef: e1b. structures) found in the module definition. *note PyModule_Create(): 3847. returns a pointer to the module object that it creates. It may abort with a fatal error for certain errors, or return ‘NULL’ if the module could not be initialized satisfactorily. The init function must return the module object to its caller, so that it then gets inserted into ‘sys.modules’. When embedding Python, the ‘PyInit_spam()’ function is not called automatically unless there’s an entry in the ‘PyImport_Inittab’ table. To add the module to the initialization table, use *note PyImport_AppendInittab(): 3848, optionally followed by an import of the module: int main(int argc, char *argv[]) { wchar_t *program = Py_DecodeLocale(argv[0], NULL); if (program == NULL) { fprintf(stderr, "Fatal error: cannot decode argv[0]\n"); exit(1); } /* Add a built-in module, before Py_Initialize */ if (PyImport_AppendInittab("spam", PyInit_spam) == -1) { fprintf(stderr, "Error: could not extend in-built modules table\n"); exit(1); } /* Pass argv[0] to the Python interpreter */ Py_SetProgramName(program); /* Initialize the Python interpreter. Required. If this step fails, it will be a fatal error. */ Py_Initialize(); /* Optionally import the module; alternatively, import can be deferred until the embedded script imports it. */ pmodule = PyImport_ImportModule("spam"); if (!pmodule) { PyErr_Print(); fprintf(stderr, "Error: could not import module 'spam'\n"); } ... PyMem_RawFree(program); return 0; } Note: Removing entries from ‘sys.modules’ or importing compiled modules into multiple interpreters within a process (or following a ‘fork()’ without an intervening ‘exec()’) can create problems for some extension modules. Extension module authors should exercise caution when initializing internal data structures. A more substantial example module is included in the Python source distribution as ‘Modules/xxmodule.c’. This file may be used as a template or simply read as an example. Note: Unlike our ‘spam’ example, ‘xxmodule’ uses `multi-phase initialization' (new in Python 3.5), where a PyModuleDef structure is returned from ‘PyInit_spam’, and creation of the module is left to the import machinery. For details on multi-phase initialization, see PEP 489(1). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0489  File: python.info, Node: Compilation and Linkage, Next: Calling Python Functions from C, Prev: The Module’s Method Table and Initialization Function, Up: Extending Python with C or C++ 6.2.1.5 Compilation and Linkage ............................... There are two more things to do before you can use your new extension: compiling and linking it with the Python system. If you use dynamic loading, the details may depend on the style of dynamic loading your system uses; see the chapters about building extension modules (chapter *note Building C and C++ Extensions: 384b.) and additional information that pertains only to building on Windows (chapter *note Building C and C++ Extensions on Windows: 1039.) for more information about this. If you can’t use dynamic loading, or if you want to make your module a permanent part of the Python interpreter, you will have to change the configuration setup and rebuild the interpreter. Luckily, this is very simple on Unix: just place your file (‘spammodule.c’ for example) in the ‘Modules/’ directory of an unpacked source distribution, add a line to the file ‘Modules/Setup.local’ describing your file: spam spammodule.o and rebuild the interpreter by running ‘make’ in the toplevel directory. You can also run ‘make’ in the ‘Modules/’ subdirectory, but then you must first rebuild ‘Makefile’ there by running ‘‘make’ Makefile’. (This is necessary each time you change the ‘Setup’ file.) If your module requires additional libraries to link with, these can be listed on the line in the configuration file as well, for instance: spam spammodule.o -lX11  File: python.info, Node: Calling Python Functions from C, Next: Extracting Parameters in Extension Functions, Prev: Compilation and Linkage, Up: Extending Python with C or C++ 6.2.1.6 Calling Python Functions from C ....................................... So far we have concentrated on making C functions callable from Python. The reverse is also useful: calling Python functions from C. This is especially the case for libraries that support so-called “callback” functions. If a C interface makes use of callbacks, the equivalent Python often needs to provide a callback mechanism to the Python programmer; the implementation will require calling the Python callback functions from a C callback. Other uses are also imaginable. Fortunately, the Python interpreter is easily called recursively, and there is a standard interface to call a Python function. (I won’t dwell on how to call the Python parser with a particular string as input — if you’re interested, have a look at the implementation of the *note -c: e9e. command line option in ‘Modules/main.c’ from the Python source code.) Calling a Python function is easy. First, the Python program must somehow pass you the Python function object. You should provide a function (or some other interface) to do this. When this function is called, save a pointer to the Python function object (be careful to *note Py_INCREF(): 265. it!) in a global variable — or wherever you see fit. For example, the following function might be part of a module definition: static PyObject *my_callback = NULL; static PyObject * my_set_callback(PyObject *dummy, PyObject *args) { PyObject *result = NULL; PyObject *temp; if (PyArg_ParseTuple(args, "O:set_callback", &temp)) { if (!PyCallable_Check(temp)) { PyErr_SetString(PyExc_TypeError, "parameter must be callable"); return NULL; } Py_XINCREF(temp); /* Add a reference to new callback */ Py_XDECREF(my_callback); /* Dispose of previous callback */ my_callback = temp; /* Remember new callback */ /* Boilerplate to return "None" */ Py_INCREF(Py_None); result = Py_None; } return result; } This function must be registered with the interpreter using the *note METH_VARARGS: e48. flag; this is described in section *note The Module’s Method Table and Initialization Function: 3845. The *note PyArg_ParseTuple(): 26a. function and its arguments are documented in section *note Extracting Parameters in Extension Functions: 3839. The macros *note Py_XINCREF(): 267. and *note Py_XDECREF(): 268. increment/decrement the reference count of an object and are safe in the presence of ‘NULL’ pointers (but note that `temp' will not be ‘NULL’ in this context). More info on them in section *note Reference Counts: 384e. Later, when it is time to call the function, you call the C function *note PyObject_CallObject(): 384f. This function has two arguments, both pointers to arbitrary Python objects: the Python function, and the argument list. The argument list must always be a tuple object, whose length is the number of arguments. To call the Python function with no arguments, pass in ‘NULL’, or an empty tuple; to call it with one argument, pass a singleton tuple. *note Py_BuildValue(): 2ce. returns a tuple when its format string consists of zero or more format codes between parentheses. For example: int arg; PyObject *arglist; PyObject *result; ... arg = 123; ... /* Time to call the callback */ arglist = Py_BuildValue("(i)", arg); result = PyObject_CallObject(my_callback, arglist); Py_DECREF(arglist); *note PyObject_CallObject(): 384f. returns a Python object pointer: this is the return value of the Python function. *note PyObject_CallObject(): 384f. is “reference-count-neutral” with respect to its arguments. In the example a new tuple was created to serve as the argument list, which is *note Py_DECREF(): 266.-ed immediately after the *note PyObject_CallObject(): 384f. call. The return value of *note PyObject_CallObject(): 384f. is “new”: either it is a brand new object, or it is an existing object whose reference count has been incremented. So, unless you want to save it in a global variable, you should somehow *note Py_DECREF(): 266. the result, even (especially!) if you are not interested in its value. Before you do this, however, it is important to check that the return value isn’t ‘NULL’. If it is, the Python function terminated by raising an exception. If the C code that called *note PyObject_CallObject(): 384f. is called from Python, it should now return an error indication to its Python caller, so the interpreter can print a stack trace, or the calling Python code can handle the exception. If this is not possible or desirable, the exception should be cleared by calling *note PyErr_Clear(): 96b. For example: if (result == NULL) return NULL; /* Pass error back */ ...use result... Py_DECREF(result); Depending on the desired interface to the Python callback function, you may also have to provide an argument list to *note PyObject_CallObject(): 384f. In some cases the argument list is also provided by the Python program, through the same interface that specified the callback function. It can then be saved and used in the same manner as the function object. In other cases, you may have to construct a new tuple to pass as the argument list. The simplest way to do this is to call *note Py_BuildValue(): 2ce. For example, if you want to pass an integral event code, you might use the following code: PyObject *arglist; ... arglist = Py_BuildValue("(l)", eventcode); result = PyObject_CallObject(my_callback, arglist); Py_DECREF(arglist); if (result == NULL) return NULL; /* Pass error back */ /* Here maybe use the result */ Py_DECREF(result); Note the placement of ‘Py_DECREF(arglist)’ immediately after the call, before the error check! Also note that strictly speaking this code is not complete: *note Py_BuildValue(): 2ce. may run out of memory, and this should be checked. You may also call a function with keyword arguments by using *note PyObject_Call(): 3850, which supports arguments and keyword arguments. As in the above example, we use *note Py_BuildValue(): 2ce. to construct the dictionary. PyObject *dict; ... dict = Py_BuildValue("{s:i}", "name", val); result = PyObject_Call(my_callback, NULL, dict); Py_DECREF(dict); if (result == NULL) return NULL; /* Pass error back */ /* Here maybe use the result */ Py_DECREF(result);  File: python.info, Node: Extracting Parameters in Extension Functions, Next: Keyword Parameters for Extension Functions, Prev: Calling Python Functions from C, Up: Extending Python with C or C++ 6.2.1.7 Extracting Parameters in Extension Functions .................................................... The *note PyArg_ParseTuple(): 26a. function is declared as follows: int PyArg_ParseTuple(PyObject *arg, const char *format, ...); The `arg' argument must be a tuple object containing an argument list passed from Python to a C function. The `format' argument must be a format string, whose syntax is explained in *note Parsing arguments and building values: 2d0. in the Python/C API Reference Manual. The remaining arguments must be addresses of variables whose type is determined by the format string. Note that while *note PyArg_ParseTuple(): 26a. checks that the Python arguments have the required types, it cannot check the validity of the addresses of C variables passed to the call: if you make mistakes there, your code will probably crash or at least overwrite random bits in memory. So be careful! Note that any Python object references which are provided to the caller are `borrowed' references; do not decrement their reference count! Some example calls: #define PY_SSIZE_T_CLEAN /* Make "s#" use Py_ssize_t rather than int. */ #include <Python.h> int ok; int i, j; long k, l; const char *s; Py_ssize_t size; ok = PyArg_ParseTuple(args, ""); /* No arguments */ /* Python call: f() */ ok = PyArg_ParseTuple(args, "s", &s); /* A string */ /* Possible Python call: f('whoops!') */ ok = PyArg_ParseTuple(args, "lls", &k, &l, &s); /* Two longs and a string */ /* Possible Python call: f(1, 2, 'three') */ ok = PyArg_ParseTuple(args, "(ii)s#", &i, &j, &s, &size); /* A pair of ints and a string, whose size is also returned */ /* Possible Python call: f((1, 2), 'three') */ { const char *file; const char *mode = "r"; int bufsize = 0; ok = PyArg_ParseTuple(args, "s|si", &file, &mode, &bufsize); /* A string, and optionally another string and an integer */ /* Possible Python calls: f('spam') f('spam', 'w') f('spam', 'wb', 100000) */ } { int left, top, right, bottom, h, v; ok = PyArg_ParseTuple(args, "((ii)(ii))(ii)", &left, &top, &right, &bottom, &h, &v); /* A rectangle and a point */ /* Possible Python call: f(((0, 0), (400, 300)), (10, 10)) */ } { Py_complex c; ok = PyArg_ParseTuple(args, "D:myfunction", &c); /* a complex, also providing a function name for errors */ /* Possible Python call: myfunction(1+2j) */ }  File: python.info, Node: Keyword Parameters for Extension Functions, Next: Building Arbitrary Values, Prev: Extracting Parameters in Extension Functions, Up: Extending Python with C or C++ 6.2.1.8 Keyword Parameters for Extension Functions .................................................. The *note PyArg_ParseTupleAndKeywords(): 5ca. function is declared as follows: int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict, const char *format, char *kwlist[], ...); The `arg' and `format' parameters are identical to those of the *note PyArg_ParseTuple(): 26a. function. The `kwdict' parameter is the dictionary of keywords received as the third parameter from the Python runtime. The `kwlist' parameter is a ‘NULL’-terminated list of strings which identify the parameters; the names are matched with the type information from `format' from left to right. On success, *note PyArg_ParseTupleAndKeywords(): 5ca. returns true, otherwise it returns false and raises an appropriate exception. Note: Nested tuples cannot be parsed when using keyword arguments! Keyword parameters passed in which are not present in the `kwlist' will cause *note TypeError: 192. to be raised. Here is an example module which uses keywords, based on an example by Geoff Philbrick (<philbrick@hks.com>): #define PY_SSIZE_T_CLEAN /* Make "s#" use Py_ssize_t rather than int. */ #include <Python.h> static PyObject * keywdarg_parrot(PyObject *self, PyObject *args, PyObject *keywds) { int voltage; const char *state = "a stiff"; const char *action = "voom"; const char *type = "Norwegian Blue"; static char *kwlist[] = {"voltage", "state", "action", "type", NULL}; if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist, &voltage, &state, &action, &type)) return NULL; printf("-- This parrot wouldn't %s if you put %i Volts through it.\n", action, voltage); printf("-- Lovely plumage, the %s -- It's %s!\n", type, state); Py_RETURN_NONE; } static PyMethodDef keywdarg_methods[] = { /* The cast of the function is necessary since PyCFunction values * only take two PyObject* parameters, and keywdarg_parrot() takes * three. */ {"parrot", (PyCFunction)(void(*)(void))keywdarg_parrot, METH_VARARGS | METH_KEYWORDS, "Print a lovely skit to standard output."}, {NULL, NULL, 0, NULL} /* sentinel */ }; static struct PyModuleDef keywdargmodule = { PyModuleDef_HEAD_INIT, "keywdarg", NULL, -1, keywdarg_methods }; PyMODINIT_FUNC PyInit_keywdarg(void) { return PyModule_Create(&keywdargmodule); }  File: python.info, Node: Building Arbitrary Values, Next: Reference Counts, Prev: Keyword Parameters for Extension Functions, Up: Extending Python with C or C++ 6.2.1.9 Building Arbitrary Values ................................. This function is the counterpart to *note PyArg_ParseTuple(): 26a. It is declared as follows: PyObject *Py_BuildValue(const char *format, ...); It recognizes a set of format units similar to the ones recognized by *note PyArg_ParseTuple(): 26a, but the arguments (which are input to the function, not output) must not be pointers, just values. It returns a new Python object, suitable for returning from a C function called from Python. One difference with *note PyArg_ParseTuple(): 26a.: while the latter requires its first argument to be a tuple (since Python argument lists are always represented as tuples internally), *note Py_BuildValue(): 2ce. does not always build a tuple. It builds a tuple only if its format string contains two or more format units. If the format string is empty, it returns ‘None’; if it contains exactly one format unit, it returns whatever object is described by that format unit. To force it to return a tuple of size 0 or one, parenthesize the format string. Examples (to the left the call, to the right the resulting Python value): Py_BuildValue("") None Py_BuildValue("i", 123) 123 Py_BuildValue("iii", 123, 456, 789) (123, 456, 789) Py_BuildValue("s", "hello") 'hello' Py_BuildValue("y", "hello") b'hello' Py_BuildValue("ss", "hello", "world") ('hello', 'world') Py_BuildValue("s#", "hello", 4) 'hell' Py_BuildValue("y#", "hello", 4) b'hell' Py_BuildValue("()") () Py_BuildValue("(i)", 123) (123,) Py_BuildValue("(ii)", 123, 456) (123, 456) Py_BuildValue("(i,i)", 123, 456) (123, 456) Py_BuildValue("[i,i]", 123, 456) [123, 456] Py_BuildValue("{s:i,s:i}", "abc", 123, "def", 456) {'abc': 123, 'def': 456} Py_BuildValue("((ii)(ii)) (ii)", 1, 2, 3, 4, 5, 6) (((1, 2), (3, 4)), (5, 6))  File: python.info, Node: Reference Counts, Next: Writing Extensions in C++, Prev: Building Arbitrary Values, Up: Extending Python with C or C++ 6.2.1.10 Reference Counts ......................... In languages like C or C++, the programmer is responsible for dynamic allocation and deallocation of memory on the heap. In C, this is done using the functions ‘malloc()’ and ‘free()’. In C++, the operators ‘new’ and ‘delete’ are used with essentially the same meaning and we’ll restrict the following discussion to the C case. Every block of memory allocated with ‘malloc()’ should eventually be returned to the pool of available memory by exactly one call to ‘free()’. It is important to call ‘free()’ at the right time. If a block’s address is forgotten but ‘free()’ is not called for it, the memory it occupies cannot be reused until the program terminates. This is called a `memory leak'. On the other hand, if a program calls ‘free()’ for a block and then continues to use the block, it creates a conflict with re-use of the block through another ‘malloc()’ call. This is called `using freed memory'. It has the same bad consequences as referencing uninitialized data — core dumps, wrong results, mysterious crashes. Common causes of memory leaks are unusual paths through the code. For instance, a function may allocate a block of memory, do some calculation, and then free the block again. Now a change in the requirements for the function may add a test to the calculation that detects an error condition and can return prematurely from the function. It’s easy to forget to free the allocated memory block when taking this premature exit, especially when it is added later to the code. Such leaks, once introduced, often go undetected for a long time: the error exit is taken only in a small fraction of all calls, and most modern machines have plenty of virtual memory, so the leak only becomes apparent in a long-running process that uses the leaking function frequently. Therefore, it’s important to prevent leaks from happening by having a coding convention or strategy that minimizes this kind of errors. Since Python makes heavy use of ‘malloc()’ and ‘free()’, it needs a strategy to avoid memory leaks as well as the use of freed memory. The chosen method is called `reference counting'. The principle is simple: every object contains a counter, which is incremented when a reference to the object is stored somewhere, and which is decremented when a reference to it is deleted. When the counter reaches zero, the last reference to the object has been deleted and the object is freed. An alternative strategy is called `automatic garbage collection'. (Sometimes, reference counting is also referred to as a garbage collection strategy, hence my use of “automatic” to distinguish the two.) The big advantage of automatic garbage collection is that the user doesn’t need to call ‘free()’ explicitly. (Another claimed advantage is an improvement in speed or memory usage — this is no hard fact however.) The disadvantage is that for C, there is no truly portable automatic garbage collector, while reference counting can be implemented portably (as long as the functions ‘malloc()’ and ‘free()’ are available — which the C Standard guarantees). Maybe some day a sufficiently portable automatic garbage collector will be available for C. Until then, we’ll have to live with reference counts. While Python uses the traditional reference counting implementation, it also offers a cycle detector that works to detect reference cycles. This allows applications to not worry about creating direct or indirect circular references; these are the weakness of garbage collection implemented using only reference counting. Reference cycles consist of objects which contain (possibly indirect) references to themselves, so that each object in the cycle has a reference count which is non-zero. Typical reference counting implementations are not able to reclaim the memory belonging to any objects in a reference cycle, or referenced from the objects in the cycle, even though there are no further references to the cycle itself. The cycle detector is able to detect garbage cycles and can reclaim them. The *note gc: 86. module exposes a way to run the detector (the *note collect(): 22e. function), as well as configuration interfaces and the ability to disable the detector at runtime. The cycle detector is considered an optional component; though it is included by default, it can be disabled at build time using the ‘--without-cycle-gc’ option to the ‘configure’ script on Unix platforms (including Mac OS X). If the cycle detector is disabled in this way, the *note gc: 86. module will not be available. * Menu: * Reference Counting in Python:: * Ownership Rules:: * Thin Ice:: * NULL Pointers::  File: python.info, Node: Reference Counting in Python, Next: Ownership Rules, Up: Reference Counts 6.2.1.11 Reference Counting in Python ..................................... There are two macros, ‘Py_INCREF(x)’ and ‘Py_DECREF(x)’, which handle the incrementing and decrementing of the reference count. *note Py_DECREF(): 266. also frees the object when the count reaches zero. For flexibility, it doesn’t call ‘free()’ directly — rather, it makes a call through a function pointer in the object’s `type object'. For this purpose (and others), every object also contains a pointer to its type object. The big question now remains: when to use ‘Py_INCREF(x)’ and ‘Py_DECREF(x)’? Let’s first introduce some terms. Nobody “owns” an object; however, you can `own a reference' to an object. An object’s reference count is now defined as the number of owned references to it. The owner of a reference is responsible for calling *note Py_DECREF(): 266. when the reference is no longer needed. Ownership of a reference can be transferred. There are three ways to dispose of an owned reference: pass it on, store it, or call *note Py_DECREF(): 266. Forgetting to dispose of an owned reference creates a memory leak. It is also possible to `borrow' (1) a reference to an object. The borrower of a reference should not call *note Py_DECREF(): 266. The borrower must not hold on to the object longer than the owner from which it was borrowed. Using a borrowed reference after the owner has disposed of it risks using freed memory and should be avoided completely (2). The advantage of borrowing over owning a reference is that you don’t need to take care of disposing of the reference on all possible paths through the code — in other words, with a borrowed reference you don’t run the risk of leaking when a premature exit is taken. The disadvantage of borrowing over owning is that there are some subtle situations where in seemingly correct code a borrowed reference can be used after the owner from which it was borrowed has in fact disposed of it. A borrowed reference can be changed into an owned reference by calling *note Py_INCREF(): 265. This does not affect the status of the owner from which the reference was borrowed — it creates a new owned reference, and gives full owner responsibilities (the new owner must dispose of the reference properly, as well as the previous owner). ---------- Footnotes ---------- (1) (2) The metaphor of “borrowing” a reference is not completely correct: the owner still has a copy of the reference. (2) (3) Checking that the reference count is at least 1 `does not work' — the reference count itself could be in freed memory and may thus be reused for another object!  File: python.info, Node: Ownership Rules, Next: Thin Ice, Prev: Reference Counting in Python, Up: Reference Counts 6.2.1.12 Ownership Rules ........................ Whenever an object reference is passed into or out of a function, it is part of the function’s interface specification whether ownership is transferred with the reference or not. Most functions that return a reference to an object pass on ownership with the reference. In particular, all functions whose function it is to create a new object, such as *note PyLong_FromLong(): 3841. and *note Py_BuildValue(): 2ce, pass ownership to the receiver. Even if the object is not actually new, you still receive ownership of a new reference to that object. For instance, *note PyLong_FromLong(): 3841. maintains a cache of popular values and can return a reference to a cached item. Many functions that extract objects from other objects also transfer ownership with the reference, for instance *note PyObject_GetAttrString(): 385b. The picture is less clear, here, however, since a few common routines are exceptions: *note PyTuple_GetItem(): 385c, *note PyList_GetItem(): 385d, *note PyDict_GetItem(): 385e, and *note PyDict_GetItemString(): 385f. all return references that you borrow from the tuple, list or dictionary. The function *note PyImport_AddModule(): 3860. also returns a borrowed reference, even though it may actually create the object it returns: this is possible because an owned reference to the object is stored in ‘sys.modules’. When you pass an object reference into another function, in general, the function borrows the reference from you — if it needs to store it, it will use *note Py_INCREF(): 265. to become an independent owner. There are exactly two important exceptions to this rule: *note PyTuple_SetItem(): 3861. and *note PyList_SetItem(): 3862. These functions take over ownership of the item passed to them — even if they fail! (Note that *note PyDict_SetItem(): 3863. and friends don’t take over ownership — they are “normal.”) When a C function is called from Python, it borrows references to its arguments from the caller. The caller owns a reference to the object, so the borrowed reference’s lifetime is guaranteed until the function returns. Only when such a borrowed reference must be stored or passed on, it must be turned into an owned reference by calling *note Py_INCREF(): 265. The object reference returned from a C function that is called from Python must be an owned reference — ownership is transferred from the function to its caller.  File: python.info, Node: Thin Ice, Next: NULL Pointers, Prev: Ownership Rules, Up: Reference Counts 6.2.1.13 Thin Ice ................. There are a few situations where seemingly harmless use of a borrowed reference can lead to problems. These all have to do with implicit invocations of the interpreter, which can cause the owner of a reference to dispose of it. The first and most important case to know about is using *note Py_DECREF(): 266. on an unrelated object while borrowing a reference to a list item. For instance: void bug(PyObject *list) { PyObject *item = PyList_GetItem(list, 0); PyList_SetItem(list, 1, PyLong_FromLong(0L)); PyObject_Print(item, stdout, 0); /* BUG! */ } This function first borrows a reference to ‘list[0]’, then replaces ‘list[1]’ with the value ‘0’, and finally prints the borrowed reference. Looks harmless, right? But it’s not! Let’s follow the control flow into *note PyList_SetItem(): 3862. The list owns references to all its items, so when item 1 is replaced, it has to dispose of the original item 1. Now let’s suppose the original item 1 was an instance of a user-defined class, and let’s further suppose that the class defined a *note __del__(): 91f. method. If this class instance has a reference count of 1, disposing of it will call its *note __del__(): 91f. method. Since it is written in Python, the *note __del__(): 91f. method can execute arbitrary Python code. Could it perhaps do something to invalidate the reference to ‘item’ in ‘bug()’? You bet! Assuming that the list passed into ‘bug()’ is accessible to the *note __del__(): 91f. method, it could execute a statement to the effect of ‘del list[0]’, and assuming this was the last reference to that object, it would free the memory associated with it, thereby invalidating ‘item’. The solution, once you know the source of the problem, is easy: temporarily increment the reference count. The correct version of the function reads: void no_bug(PyObject *list) { PyObject *item = PyList_GetItem(list, 0); Py_INCREF(item); PyList_SetItem(list, 1, PyLong_FromLong(0L)); PyObject_Print(item, stdout, 0); Py_DECREF(item); } This is a true story. An older version of Python contained variants of this bug and someone spent a considerable amount of time in a C debugger to figure out why his *note __del__(): 91f. methods would fail… The second case of problems with a borrowed reference is a variant involving threads. Normally, multiple threads in the Python interpreter can’t get in each other’s way, because there is a global lock protecting Python’s entire object space. However, it is possible to temporarily release this lock using the macro *note Py_BEGIN_ALLOW_THREADS: 3866, and to re-acquire it using *note Py_END_ALLOW_THREADS: 2b5. This is common around blocking I/O calls, to let other threads use the processor while waiting for the I/O to complete. Obviously, the following function has the same problem as the previous one: void bug(PyObject *list) { PyObject *item = PyList_GetItem(list, 0); Py_BEGIN_ALLOW_THREADS ...some blocking I/O call... Py_END_ALLOW_THREADS PyObject_Print(item, stdout, 0); /* BUG! */ }  File: python.info, Node: NULL Pointers, Prev: Thin Ice, Up: Reference Counts 6.2.1.14 NULL Pointers ...................... In general, functions that take object references as arguments do not expect you to pass them ‘NULL’ pointers, and will dump core (or cause later core dumps) if you do so. Functions that return object references generally return ‘NULL’ only to indicate that an exception occurred. The reason for not testing for ‘NULL’ arguments is that functions often pass the objects they receive on to other function — if each function were to test for ‘NULL’, there would be a lot of redundant tests and the code would run more slowly. It is better to test for ‘NULL’ only at the “source:” when a pointer that may be ‘NULL’ is received, for example, from ‘malloc()’ or from a function that may raise an exception. The macros *note Py_INCREF(): 265. and *note Py_DECREF(): 266. do not check for ‘NULL’ pointers — however, their variants *note Py_XINCREF(): 267. and *note Py_XDECREF(): 268. do. The macros for checking for a particular object type (‘Pytype_Check()’) don’t check for ‘NULL’ pointers — again, there is much code that calls several of these in a row to test an object against various different expected types, and this would generate redundant tests. There are no variants with ‘NULL’ checking. The C function calling mechanism guarantees that the argument list passed to C functions (‘args’ in the examples) is never ‘NULL’ — in fact it guarantees that it is always a tuple (1). It is a severe error to ever let a ‘NULL’ pointer “escape” to the Python user. ---------- Footnotes ---------- (1) (4) These guarantees don’t hold when you use the “old” style calling convention — this is still found in much existing code.  File: python.info, Node: Writing Extensions in C++, Next: Providing a C API for an Extension Module, Prev: Reference Counts, Up: Extending Python with C or C++ 6.2.1.15 Writing Extensions in C++ .................................. It is possible to write extension modules in C++. Some restrictions apply. If the main program (the Python interpreter) is compiled and linked by the C compiler, global or static objects with constructors cannot be used. This is not a problem if the main program is linked by the C++ compiler. Functions that will be called by the Python interpreter (in particular, module initialization functions) have to be declared using ‘extern "C"’. It is unnecessary to enclose the Python header files in ‘extern "C" {...}’ — they use this form already if the symbol ‘__cplusplus’ is defined (all recent C++ compilers define this symbol).  File: python.info, Node: Providing a C API for an Extension Module, Prev: Writing Extensions in C++, Up: Extending Python with C or C++ 6.2.1.16 Providing a C API for an Extension Module .................................................. Many extension modules just provide new functions and types to be used from Python, but sometimes the code in an extension module can be useful for other extension modules. For example, an extension module could implement a type “collection” which works like lists without order. Just like the standard Python list type has a C API which permits extension modules to create and manipulate lists, this new collection type should have a set of C functions for direct manipulation from other extension modules. At first sight this seems easy: just write the functions (without declaring them ‘static’, of course), provide an appropriate header file, and document the C API. And in fact this would work if all extension modules were always linked statically with the Python interpreter. When modules are used as shared libraries, however, the symbols defined in one module may not be visible to another module. The details of visibility depend on the operating system; some systems use one global namespace for the Python interpreter and all extension modules (Windows, for example), whereas others require an explicit list of imported symbols at module link time (AIX is one example), or offer a choice of different strategies (most Unices). And even if symbols are globally visible, the module whose functions one wishes to call might not have been loaded yet! Portability therefore requires not to make any assumptions about symbol visibility. This means that all symbols in extension modules should be declared ‘static’, except for the module’s initialization function, in order to avoid name clashes with other extension modules (as discussed in section *note The Module’s Method Table and Initialization Function: 3845.). And it means that symbols that `should' be accessible from other extension modules must be exported in a different way. Python provides a special mechanism to pass C-level information (pointers) from one extension module to another one: Capsules. A Capsule is a Python data type which stores a pointer (‘void *’). Capsules can only be created and accessed via their C API, but they can be passed around like any other Python object. In particular, they can be assigned to a name in an extension module’s namespace. Other extension modules can then import this module, retrieve the value of this name, and then retrieve the pointer from the Capsule. There are many ways in which Capsules can be used to export the C API of an extension module. Each function could get its own Capsule, or all C API pointers could be stored in an array whose address is published in a Capsule. And the various tasks of storing and retrieving the pointers can be distributed in different ways between the module providing the code and the client modules. Whichever method you choose, it’s important to name your Capsules properly. The function *note PyCapsule_New(): 386c. takes a name parameter (‘const char *’); you’re permitted to pass in a ‘NULL’ name, but we strongly encourage you to specify a name. Properly named Capsules provide a degree of runtime type-safety; there is no feasible way to tell one unnamed Capsule from another. In particular, Capsules used to expose C APIs should be given a name following this convention: modulename.attributename The convenience function *note PyCapsule_Import(): 386d. makes it easy to load a C API provided via a Capsule, but only if the Capsule’s name matches this convention. This behavior gives C API users a high degree of certainty that the Capsule they load contains the correct C API. The following example demonstrates an approach that puts most of the burden on the writer of the exporting module, which is appropriate for commonly used library modules. It stores all C API pointers (just one in the example!) in an array of ‘void’ pointers which becomes the value of a Capsule. The header file corresponding to the module provides a macro that takes care of importing the module and retrieving its C API pointers; client modules only have to call this macro before accessing the C API. The exporting module is a modification of the ‘spam’ module from section *note A Simple Example: 3838. The function ‘spam.system()’ does not call the C library function ‘system()’ directly, but a function ‘PySpam_System()’, which would of course do something more complicated in reality (such as adding “spam” to every command). This function ‘PySpam_System()’ is also exported to other extension modules. The function ‘PySpam_System()’ is a plain C function, declared ‘static’ like everything else: static int PySpam_System(const char *command) { return system(command); } The function ‘spam_system()’ is modified in a trivial way: static PyObject * spam_system(PyObject *self, PyObject *args) { const char *command; int sts; if (!PyArg_ParseTuple(args, "s", &command)) return NULL; sts = PySpam_System(command); return PyLong_FromLong(sts); } In the beginning of the module, right after the line #include <Python.h> two more lines must be added: #define SPAM_MODULE #include "spammodule.h" The ‘#define’ is used to tell the header file that it is being included in the exporting module, not a client module. Finally, the module’s initialization function must take care of initializing the C API pointer array: PyMODINIT_FUNC PyInit_spam(void) { PyObject *m; static void *PySpam_API[PySpam_API_pointers]; PyObject *c_api_object; m = PyModule_Create(&spammodule); if (m == NULL) return NULL; /* Initialize the C API pointer array */ PySpam_API[PySpam_System_NUM] = (void *)PySpam_System; /* Create a Capsule containing the API pointer array's address */ c_api_object = PyCapsule_New((void *)PySpam_API, "spam._C_API", NULL); if (PyModule_AddObject(m, "_C_API", c_api_object) < 0) { Py_XDECREF(c_api_object); Py_DECREF(m); return NULL; } return m; } Note that ‘PySpam_API’ is declared ‘static’; otherwise the pointer array would disappear when ‘PyInit_spam()’ terminates! The bulk of the work is in the header file ‘spammodule.h’, which looks like this: #ifndef Py_SPAMMODULE_H #define Py_SPAMMODULE_H #ifdef __cplusplus extern "C" { #endif /* Header file for spammodule */ /* C API functions */ #define PySpam_System_NUM 0 #define PySpam_System_RETURN int #define PySpam_System_PROTO (const char *command) /* Total number of C API pointers */ #define PySpam_API_pointers 1 #ifdef SPAM_MODULE /* This section is used when compiling spammodule.c */ static PySpam_System_RETURN PySpam_System PySpam_System_PROTO; #else /* This section is used in modules that use spammodule's API */ static void **PySpam_API; #define PySpam_System \ (*(PySpam_System_RETURN (*)PySpam_System_PROTO) PySpam_API[PySpam_System_NUM]) /* Return -1 on error, 0 on success. * PyCapsule_Import will set an exception if there's an error. */ static int import_spam(void) { PySpam_API = (void **)PyCapsule_Import("spam._C_API", 0); return (PySpam_API != NULL) ? 0 : -1; } #endif #ifdef __cplusplus } #endif #endif /* !defined(Py_SPAMMODULE_H) */ All that a client module must do in order to have access to the function ‘PySpam_System()’ is to call the function (or rather macro) ‘import_spam()’ in its initialization function: PyMODINIT_FUNC PyInit_client(void) { PyObject *m; m = PyModule_Create(&clientmodule); if (m == NULL) return NULL; if (import_spam() < 0) return NULL; /* additional initialization can happen here */ return m; } The main disadvantage of this approach is that the file ‘spammodule.h’ is rather complicated. However, the basic structure is the same for each function that is exported, so it has to be learned only once. Finally it should be mentioned that Capsules offer additional functionality, which is especially useful for memory allocation and deallocation of the pointer stored in a Capsule. The details are described in the Python/C API Reference Manual in the section *note Capsules: 386e. and in the implementation of Capsules (files ‘Include/pycapsule.h’ and ‘Objects/pycapsule.c’ in the Python source code distribution).  File: python.info, Node: Defining Extension Types Tutorial, Next: Defining Extension Types Assorted Topics, Prev: Extending Python with C or C++, Up: Creating extensions without third party tools 6.2.2 Defining Extension Types: Tutorial ---------------------------------------- Python allows the writer of a C extension module to define new types that can be manipulated from Python code, much like the built-in *note str: 330. and *note list: 262. types. The code for all extension types follows a pattern, but there are some details that you need to understand before you can get started. This document is a gentle introduction to the topic. * Menu: * The Basics:: * Adding data and methods to the Basic example:: * Providing finer control over data attributes:: * Supporting cyclic garbage collection:: * Subclassing other types::  File: python.info, Node: The Basics, Next: Adding data and methods to the Basic example, Up: Defining Extension Types Tutorial 6.2.2.1 The Basics .................. The *note CPython: 10d7. runtime sees all Python objects as variables of type *note PyObject*: 4ba, which serves as a “base type” for all Python objects. The *note PyObject: 4ba. structure itself only contains the object’s *note reference count: 3874. and a pointer to the object’s “type object”. This is where the action is; the type object determines which (C) functions get called by the interpreter when, for instance, an attribute gets looked up on an object, a method called, or it is multiplied by another object. These C functions are called “type methods”. So, if you want to define a new extension type, you need to create a new type object. This sort of thing can only be explained by example, so here’s a minimal, but complete, module that defines a new type named ‘Custom’ inside a C extension module ‘custom’: Note: What we’re showing here is the traditional way of defining `static' extension types. It should be adequate for most uses. The C API also allows defining heap-allocated extension types using the *note PyType_FromSpec(): 2d1. function, which isn’t covered in this tutorial. #define PY_SSIZE_T_CLEAN #include <Python.h> typedef struct { PyObject_HEAD /* Type-specific fields go here. */ } CustomObject; static PyTypeObject CustomType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "custom.Custom", .tp_doc = "Custom objects", .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT, .tp_new = PyType_GenericNew, }; static PyModuleDef custommodule = { PyModuleDef_HEAD_INIT, .m_name = "custom", .m_doc = "Example module that creates an extension type.", .m_size = -1, }; PyMODINIT_FUNC PyInit_custom(void) { PyObject *m; if (PyType_Ready(&CustomType) < 0) return NULL; m = PyModule_Create(&custommodule); if (m == NULL) return NULL; Py_INCREF(&CustomType); if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) { Py_DECREF(&CustomType); Py_DECREF(m); return NULL; } return m; } Now that’s quite a bit to take in at once, but hopefully bits will seem familiar from the previous chapter. This file defines three things: 1. What a ‘Custom’ `object' contains: this is the ‘CustomObject’ struct, which is allocated once for each ‘Custom’ instance. 2. How the ‘Custom’ `type' behaves: this is the ‘CustomType’ struct, which defines a set of flags and function pointers that the interpreter inspects when specific operations are requested. 3. How to initialize the ‘custom’ module: this is the ‘PyInit_custom’ function and the associated ‘custommodule’ struct. The first bit is: typedef struct { PyObject_HEAD } CustomObject; This is what a Custom object will contain. ‘PyObject_HEAD’ is mandatory at the start of each object struct and defines a field called ‘ob_base’ of type *note PyObject: 4ba, containing a pointer to a type object and a reference count (these can be accessed using the macros *note Py_REFCNT: 3875. and *note Py_TYPE: 3876. respectively). The reason for the macro is to abstract away the layout and to enable additional fields in debug builds. Note: There is no semicolon above after the *note PyObject_HEAD: c72. macro. Be wary of adding one by accident: some compilers will complain. Of course, objects generally store additional data besides the standard ‘PyObject_HEAD’ boilerplate; for example, here is the definition for standard Python floats: typedef struct { PyObject_HEAD double ob_fval; } PyFloatObject; The second bit is the definition of the type object. static PyTypeObject CustomType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "custom.Custom", .tp_doc = "Custom objects", .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT, .tp_new = PyType_GenericNew, }; Note: We recommend using C99-style designated initializers as above, to avoid listing all the *note PyTypeObject: 2d6. fields that you don’t care about and also to avoid caring about the fields’ declaration order. The actual definition of *note PyTypeObject: 2d6. in ‘object.h’ has many more *note fields: 3877. than the definition above. The remaining fields will be filled with zeros by the C compiler, and it’s common practice to not specify them explicitly unless you need them. We’re going to pick it apart, one field at a time: PyVarObject_HEAD_INIT(NULL, 0) This line is mandatory boilerplate to initialize the ‘ob_base’ field mentioned above. .tp_name = "custom.Custom", The name of our type. This will appear in the default textual representation of our objects and in some error messages, for example: >>> "" + custom.Custom() Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: can only concatenate str (not "custom.Custom") to str Note that the name is a dotted name that includes both the module name and the name of the type within the module. The module in this case is ‘custom’ and the type is ‘Custom’, so we set the type name to ‘custom.Custom’. Using the real dotted import path is important to make your type compatible with the *note pydoc: d9. and *note pickle: ca. modules. .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, This is so that Python knows how much memory to allocate when creating new ‘Custom’ instances. *note tp_itemsize: 3878. is only used for variable-sized objects and should otherwise be zero. Note: If you want your type to be subclassable from Python, and your type has the same *note tp_basicsize: 3879. as its base type, you may have problems with multiple inheritance. A Python subclass of your type will have to list your type first in its *note __bases__: e09, or else it will not be able to call your type’s *note __new__(): 889. method without getting an error. You can avoid this problem by ensuring that your type has a larger value for *note tp_basicsize: 3879. than its base type does. Most of the time, this will be true anyway, because either your base type will be *note object: 2b0, or else you will be adding data members to your base type, and therefore increasing its size. We set the class flags to *note Py_TPFLAGS_DEFAULT: 387a. .tp_flags = Py_TPFLAGS_DEFAULT, All types should include this constant in their flags. It enables all of the members defined until at least Python 3.3. If you need further members, you will need to OR the corresponding flags. We provide a doc string for the type in *note tp_doc: 387b. .tp_doc = "Custom objects", To enable object creation, we have to provide a *note tp_new: 387c. handler. This is the equivalent of the Python method *note __new__(): 889, but has to be specified explicitly. In this case, we can just use the default implementation provided by the API function *note PyType_GenericNew(): 387d. .tp_new = PyType_GenericNew, Everything else in the file should be familiar, except for some code in ‘PyInit_custom()’: if (PyType_Ready(&CustomType) < 0) return; This initializes the ‘Custom’ type, filling in a number of members to the appropriate default values, including ‘ob_type’ that we initially set to ‘NULL’. Py_INCREF(&CustomType); if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) { Py_DECREF(&CustomType); Py_DECREF(m); return NULL; } This adds the type to the module dictionary. This allows us to create ‘Custom’ instances by calling the ‘Custom’ class: >>> import custom >>> mycustom = custom.Custom() That’s it! All that remains is to build it; put the above code in a file called ‘custom.c’ and: from distutils.core import setup, Extension setup(name="custom", version="1.0", ext_modules=[Extension("custom", ["custom.c"])]) in a file called ‘setup.py’; then typing $ python setup.py build at a shell should produce a file ‘custom.so’ in a subdirectory; move to that directory and fire up Python — you should be able to ‘import custom’ and play around with Custom objects. That wasn’t so hard, was it? Of course, the current Custom type is pretty uninteresting. It has no data and doesn’t do anything. It can’t even be subclassed. Note: While this documentation showcases the standard *note distutils: 39. module for building C extensions, it is recommended in real-world use cases to use the newer and better-maintained ‘setuptools’ library. Documentation on how to do this is out of scope for this document and can be found in the Python Packaging User’s Guide(1). ---------- Footnotes ---------- (1) https://packaging.python.org/tutorials/distributing-packages/  File: python.info, Node: Adding data and methods to the Basic example, Next: Providing finer control over data attributes, Prev: The Basics, Up: Defining Extension Types Tutorial 6.2.2.2 Adding data and methods to the Basic example .................................................... Let’s extend the basic example to add some data and methods. Let’s also make the type usable as a base class. We’ll create a new module, ‘custom2’ that adds these capabilities: #define PY_SSIZE_T_CLEAN #include <Python.h> #include "structmember.h" typedef struct { PyObject_HEAD PyObject *first; /* first name */ PyObject *last; /* last name */ int number; } CustomObject; static void Custom_dealloc(CustomObject *self) { Py_XDECREF(self->first); Py_XDECREF(self->last); Py_TYPE(self)->tp_free((PyObject *) self); } static PyObject * Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds) { CustomObject *self; self = (CustomObject *) type->tp_alloc(type, 0); if (self != NULL) { self->first = PyUnicode_FromString(""); if (self->first == NULL) { Py_DECREF(self); return NULL; } self->last = PyUnicode_FromString(""); if (self->last == NULL) { Py_DECREF(self); return NULL; } self->number = 0; } return (PyObject *) self; } static int Custom_init(CustomObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"first", "last", "number", NULL}; PyObject *first = NULL, *last = NULL, *tmp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist, &first, &last, &self->number)) return -1; if (first) { tmp = self->first; Py_INCREF(first); self->first = first; Py_XDECREF(tmp); } if (last) { tmp = self->last; Py_INCREF(last); self->last = last; Py_XDECREF(tmp); } return 0; } static PyMemberDef Custom_members[] = { {"first", T_OBJECT_EX, offsetof(CustomObject, first), 0, "first name"}, {"last", T_OBJECT_EX, offsetof(CustomObject, last), 0, "last name"}, {"number", T_INT, offsetof(CustomObject, number), 0, "custom number"}, {NULL} /* Sentinel */ }; static PyObject * Custom_name(CustomObject *self, PyObject *Py_UNUSED(ignored)) { if (self->first == NULL) { PyErr_SetString(PyExc_AttributeError, "first"); return NULL; } if (self->last == NULL) { PyErr_SetString(PyExc_AttributeError, "last"); return NULL; } return PyUnicode_FromFormat("%S %S", self->first, self->last); } static PyMethodDef Custom_methods[] = { {"name", (PyCFunction) Custom_name, METH_NOARGS, "Return the name, combining the first and last name" }, {NULL} /* Sentinel */ }; static PyTypeObject CustomType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "custom2.Custom", .tp_doc = "Custom objects", .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, .tp_new = Custom_new, .tp_init = (initproc) Custom_init, .tp_dealloc = (destructor) Custom_dealloc, .tp_members = Custom_members, .tp_methods = Custom_methods, }; static PyModuleDef custommodule = { PyModuleDef_HEAD_INIT, .m_name = "custom2", .m_doc = "Example module that creates an extension type.", .m_size = -1, }; PyMODINIT_FUNC PyInit_custom2(void) { PyObject *m; if (PyType_Ready(&CustomType) < 0) return NULL; m = PyModule_Create(&custommodule); if (m == NULL) return NULL; Py_INCREF(&CustomType); if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) { Py_DECREF(&CustomType); Py_DECREF(m); return NULL; } return m; } This version of the module has a number of changes. We’ve added an extra include: #include <structmember.h> This include provides declarations that we use to handle attributes, as described a bit later. The ‘Custom’ type now has three data attributes in its C struct, `first', `last', and `number'. The `first' and `last' variables are Python strings containing first and last names. The `number' attribute is a C integer. The object structure is updated accordingly: typedef struct { PyObject_HEAD PyObject *first; /* first name */ PyObject *last; /* last name */ int number; } CustomObject; Because we now have data to manage, we have to be more careful about object allocation and deallocation. At a minimum, we need a deallocation method: static void Custom_dealloc(CustomObject *self) { Py_XDECREF(self->first); Py_XDECREF(self->last); Py_TYPE(self)->tp_free((PyObject *) self); } which is assigned to the *note tp_dealloc: 387f. member: .tp_dealloc = (destructor) Custom_dealloc, This method first clears the reference counts of the two Python attributes. *note Py_XDECREF(): 268. correctly handles the case where its argument is ‘NULL’ (which might happen here if ‘tp_new’ failed midway). It then calls the *note tp_free: 3880. member of the object’s type (computed by ‘Py_TYPE(self)’) to free the object’s memory. Note that the object’s type might not be ‘CustomType’, because the object may be an instance of a subclass. Note: The explicit cast to ‘destructor’ above is needed because we defined ‘Custom_dealloc’ to take a ‘CustomObject *’ argument, but the ‘tp_dealloc’ function pointer expects to receive a ‘PyObject *’ argument. Otherwise, the compiler will emit a warning. This is object-oriented polymorphism, in C! We want to make sure that the first and last names are initialized to empty strings, so we provide a ‘tp_new’ implementation: static PyObject * Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds) { CustomObject *self; self = (CustomObject *) type->tp_alloc(type, 0); if (self != NULL) { self->first = PyUnicode_FromString(""); if (self->first == NULL) { Py_DECREF(self); return NULL; } self->last = PyUnicode_FromString(""); if (self->last == NULL) { Py_DECREF(self); return NULL; } self->number = 0; } return (PyObject *) self; } and install it in the *note tp_new: 387c. member: .tp_new = Custom_new, The ‘tp_new’ handler is responsible for creating (as opposed to initializing) objects of the type. It is exposed in Python as the *note __new__(): 889. method. It is not required to define a ‘tp_new’ member, and indeed many extension types will simply reuse *note PyType_GenericNew(): 387d. as done in the first version of the ‘Custom’ type above. In this case, we use the ‘tp_new’ handler to initialize the ‘first’ and ‘last’ attributes to non-‘NULL’ default values. ‘tp_new’ is passed the type being instantiated (not necessarily ‘CustomType’, if a subclass is instantiated) and any arguments passed when the type was called, and is expected to return the instance created. ‘tp_new’ handlers always accept positional and keyword arguments, but they often ignore the arguments, leaving the argument handling to initializer (a.k.a. ‘tp_init’ in C or ‘__init__’ in Python) methods. Note: ‘tp_new’ shouldn’t call ‘tp_init’ explicitly, as the interpreter will do it itself. The ‘tp_new’ implementation calls the *note tp_alloc: 3881. slot to allocate memory: self = (CustomObject *) type->tp_alloc(type, 0); Since memory allocation may fail, we must check the *note tp_alloc: 3881. result against ‘NULL’ before proceeding. Note: We didn’t fill the *note tp_alloc: 3881. slot ourselves. Rather *note PyType_Ready(): 3882. fills it for us by inheriting it from our base class, which is *note object: 2b0. by default. Most types use the default allocation strategy. Note: If you are creating a co-operative *note tp_new: 387c. (one that calls a base type’s *note tp_new: 387c. or *note __new__(): 889.), you must `not' try to determine what method to call using method resolution order at runtime. Always statically determine what type you are going to call, and call its *note tp_new: 387c. directly, or via ‘type->tp_base->tp_new’. If you do not do this, Python subclasses of your type that also inherit from other Python-defined classes may not work correctly. (Specifically, you may not be able to create instances of such subclasses without getting a *note TypeError: 192.) We also define an initialization function which accepts arguments to provide initial values for our instance: static int Custom_init(CustomObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"first", "last", "number", NULL}; PyObject *first = NULL, *last = NULL, *tmp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist, &first, &last, &self->number)) return -1; if (first) { tmp = self->first; Py_INCREF(first); self->first = first; Py_XDECREF(tmp); } if (last) { tmp = self->last; Py_INCREF(last); self->last = last; Py_XDECREF(tmp); } return 0; } by filling the *note tp_init: 3883. slot. .tp_init = (initproc) Custom_init, The *note tp_init: 3883. slot is exposed in Python as the *note __init__(): d5e. method. It is used to initialize an object after it’s created. Initializers always accept positional and keyword arguments, and they should return either ‘0’ on success or ‘-1’ on error. Unlike the ‘tp_new’ handler, there is no guarantee that ‘tp_init’ is called at all (for example, the *note pickle: ca. module by default doesn’t call *note __init__(): d5e. on unpickled instances). It can also be called multiple times. Anyone can call the *note __init__(): d5e. method on our objects. For this reason, we have to be extra careful when assigning the new attribute values. We might be tempted, for example to assign the ‘first’ member like this: if (first) { Py_XDECREF(self->first); Py_INCREF(first); self->first = first; } But this would be risky. Our type doesn’t restrict the type of the ‘first’ member, so it could be any kind of object. It could have a destructor that causes code to be executed that tries to access the ‘first’ member; or that destructor could release the *note Global interpreter Lock: bea. and let arbitrary code run in other threads that accesses and modifies our object. To be paranoid and protect ourselves against this possibility, we almost always reassign members before decrementing their reference counts. When don’t we have to do this? * when we absolutely know that the reference count is greater than 1; * when we know that deallocation of the object (1) will neither release the *note GIL: bea. nor cause any calls back into our type’s code; * when decrementing a reference count in a *note tp_dealloc: 387f. handler on a type which doesn’t support cyclic garbage collection (2). We want to expose our instance variables as attributes. There are a number of ways to do that. The simplest way is to define member definitions: static PyMemberDef Custom_members[] = { {"first", T_OBJECT_EX, offsetof(CustomObject, first), 0, "first name"}, {"last", T_OBJECT_EX, offsetof(CustomObject, last), 0, "last name"}, {"number", T_INT, offsetof(CustomObject, number), 0, "custom number"}, {NULL} /* Sentinel */ }; and put the definitions in the *note tp_members: 3884. slot: .tp_members = Custom_members, Each member definition has a member name, type, offset, access flags and documentation string. See the *note Generic Attribute Management: 3885. section below for details. A disadvantage of this approach is that it doesn’t provide a way to restrict the types of objects that can be assigned to the Python attributes. We expect the first and last names to be strings, but any Python objects can be assigned. Further, the attributes can be deleted, setting the C pointers to ‘NULL’. Even though we can make sure the members are initialized to non-‘NULL’ values, the members can be set to ‘NULL’ if the attributes are deleted. We define a single method, ‘Custom.name()’, that outputs the objects name as the concatenation of the first and last names. static PyObject * Custom_name(CustomObject *self, PyObject *Py_UNUSED(ignored)) { if (self->first == NULL) { PyErr_SetString(PyExc_AttributeError, "first"); return NULL; } if (self->last == NULL) { PyErr_SetString(PyExc_AttributeError, "last"); return NULL; } return PyUnicode_FromFormat("%S %S", self->first, self->last); } The method is implemented as a C function that takes a ‘Custom’ (or ‘Custom’ subclass) instance as the first argument. Methods always take an instance as the first argument. Methods often take positional and keyword arguments as well, but in this case we don’t take any and don’t need to accept a positional argument tuple or keyword argument dictionary. This method is equivalent to the Python method: def name(self): return "%s %s" % (self.first, self.last) Note that we have to check for the possibility that our ‘first’ and ‘last’ members are ‘NULL’. This is because they can be deleted, in which case they are set to ‘NULL’. It would be better to prevent deletion of these attributes and to restrict the attribute values to be strings. We’ll see how to do that in the next section. Now that we’ve defined the method, we need to create an array of method definitions: static PyMethodDef Custom_methods[] = { {"name", (PyCFunction) Custom_name, METH_NOARGS, "Return the name, combining the first and last name" }, {NULL} /* Sentinel */ }; (note that we used the *note METH_NOARGS: e18. flag to indicate that the method is expecting no arguments other than `self') and assign it to the *note tp_methods: 3886. slot: .tp_methods = Custom_methods, Finally, we’ll make our type usable as a base class for subclassing. We’ve written our methods carefully so far so that they don’t make any assumptions about the type of the object being created or used, so all we need to do is to add the *note Py_TPFLAGS_BASETYPE: 3887. to our class flag definition: .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, We rename ‘PyInit_custom()’ to ‘PyInit_custom2()’, update the module name in the *note PyModuleDef: 3888. struct, and update the full class name in the *note PyTypeObject: 2d6. struct. Finally, we update our ‘setup.py’ file to build the new module: from distutils.core import setup, Extension setup(name="custom", version="1.0", ext_modules=[ Extension("custom", ["custom.c"]), Extension("custom2", ["custom2.c"]), ]) ---------- Footnotes ---------- (1) (1) This is true when we know that the object is a basic type, like a string or a float. (2) (2) We relied on this in the *note tp_dealloc: 387f. handler in this example, because our type doesn’t support garbage collection.  File: python.info, Node: Providing finer control over data attributes, Next: Supporting cyclic garbage collection, Prev: Adding data and methods to the Basic example, Up: Defining Extension Types Tutorial 6.2.2.3 Providing finer control over data attributes .................................................... In this section, we’ll provide finer control over how the ‘first’ and ‘last’ attributes are set in the ‘Custom’ example. In the previous version of our module, the instance variables ‘first’ and ‘last’ could be set to non-string values or even deleted. We want to make sure that these attributes always contain strings. #define PY_SSIZE_T_CLEAN #include <Python.h> #include "structmember.h" typedef struct { PyObject_HEAD PyObject *first; /* first name */ PyObject *last; /* last name */ int number; } CustomObject; static void Custom_dealloc(CustomObject *self) { Py_XDECREF(self->first); Py_XDECREF(self->last); Py_TYPE(self)->tp_free((PyObject *) self); } static PyObject * Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds) { CustomObject *self; self = (CustomObject *) type->tp_alloc(type, 0); if (self != NULL) { self->first = PyUnicode_FromString(""); if (self->first == NULL) { Py_DECREF(self); return NULL; } self->last = PyUnicode_FromString(""); if (self->last == NULL) { Py_DECREF(self); return NULL; } self->number = 0; } return (PyObject *) self; } static int Custom_init(CustomObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"first", "last", "number", NULL}; PyObject *first = NULL, *last = NULL, *tmp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist, &first, &last, &self->number)) return -1; if (first) { tmp = self->first; Py_INCREF(first); self->first = first; Py_DECREF(tmp); } if (last) { tmp = self->last; Py_INCREF(last); self->last = last; Py_DECREF(tmp); } return 0; } static PyMemberDef Custom_members[] = { {"number", T_INT, offsetof(CustomObject, number), 0, "custom number"}, {NULL} /* Sentinel */ }; static PyObject * Custom_getfirst(CustomObject *self, void *closure) { Py_INCREF(self->first); return self->first; } static int Custom_setfirst(CustomObject *self, PyObject *value, void *closure) { PyObject *tmp; if (value == NULL) { PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute"); return -1; } if (!PyUnicode_Check(value)) { PyErr_SetString(PyExc_TypeError, "The first attribute value must be a string"); return -1; } tmp = self->first; Py_INCREF(value); self->first = value; Py_DECREF(tmp); return 0; } static PyObject * Custom_getlast(CustomObject *self, void *closure) { Py_INCREF(self->last); return self->last; } static int Custom_setlast(CustomObject *self, PyObject *value, void *closure) { PyObject *tmp; if (value == NULL) { PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute"); return -1; } if (!PyUnicode_Check(value)) { PyErr_SetString(PyExc_TypeError, "The last attribute value must be a string"); return -1; } tmp = self->last; Py_INCREF(value); self->last = value; Py_DECREF(tmp); return 0; } static PyGetSetDef Custom_getsetters[] = { {"first", (getter) Custom_getfirst, (setter) Custom_setfirst, "first name", NULL}, {"last", (getter) Custom_getlast, (setter) Custom_setlast, "last name", NULL}, {NULL} /* Sentinel */ }; static PyObject * Custom_name(CustomObject *self, PyObject *Py_UNUSED(ignored)) { return PyUnicode_FromFormat("%S %S", self->first, self->last); } static PyMethodDef Custom_methods[] = { {"name", (PyCFunction) Custom_name, METH_NOARGS, "Return the name, combining the first and last name" }, {NULL} /* Sentinel */ }; static PyTypeObject CustomType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "custom3.Custom", .tp_doc = "Custom objects", .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, .tp_new = Custom_new, .tp_init = (initproc) Custom_init, .tp_dealloc = (destructor) Custom_dealloc, .tp_members = Custom_members, .tp_methods = Custom_methods, .tp_getset = Custom_getsetters, }; static PyModuleDef custommodule = { PyModuleDef_HEAD_INIT, .m_name = "custom3", .m_doc = "Example module that creates an extension type.", .m_size = -1, }; PyMODINIT_FUNC PyInit_custom3(void) { PyObject *m; if (PyType_Ready(&CustomType) < 0) return NULL; m = PyModule_Create(&custommodule); if (m == NULL) return NULL; Py_INCREF(&CustomType); if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) { Py_DECREF(&CustomType); Py_DECREF(m); return NULL; } return m; } To provide greater control, over the ‘first’ and ‘last’ attributes, we’ll use custom getter and setter functions. Here are the functions for getting and setting the ‘first’ attribute: static PyObject * Custom_getfirst(CustomObject *self, void *closure) { Py_INCREF(self->first); return self->first; } static int Custom_setfirst(CustomObject *self, PyObject *value, void *closure) { PyObject *tmp; if (value == NULL) { PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute"); return -1; } if (!PyUnicode_Check(value)) { PyErr_SetString(PyExc_TypeError, "The first attribute value must be a string"); return -1; } tmp = self->first; Py_INCREF(value); self->first = value; Py_DECREF(tmp); return 0; } The getter function is passed a ‘Custom’ object and a “closure”, which is a void pointer. In this case, the closure is ignored. (The closure supports an advanced usage in which definition data is passed to the getter and setter. This could, for example, be used to allow a single set of getter and setter functions that decide the attribute to get or set based on data in the closure.) The setter function is passed the ‘Custom’ object, the new value, and the closure. The new value may be ‘NULL’, in which case the attribute is being deleted. In our setter, we raise an error if the attribute is deleted or if its new value is not a string. We create an array of *note PyGetSetDef: 427. structures: static PyGetSetDef Custom_getsetters[] = { {"first", (getter) Custom_getfirst, (setter) Custom_setfirst, "first name", NULL}, {"last", (getter) Custom_getlast, (setter) Custom_setlast, "last name", NULL}, {NULL} /* Sentinel */ }; and register it in the *note tp_getset: 388a. slot: .tp_getset = Custom_getsetters, The last item in a *note PyGetSetDef: 427. structure is the “closure” mentioned above. In this case, we aren’t using a closure, so we just pass ‘NULL’. We also remove the member definitions for these attributes: static PyMemberDef Custom_members[] = { {"number", T_INT, offsetof(CustomObject, number), 0, "custom number"}, {NULL} /* Sentinel */ }; We also need to update the *note tp_init: 3883. handler to only allow strings (1) to be passed: static int Custom_init(CustomObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"first", "last", "number", NULL}; PyObject *first = NULL, *last = NULL, *tmp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist, &first, &last, &self->number)) return -1; if (first) { tmp = self->first; Py_INCREF(first); self->first = first; Py_DECREF(tmp); } if (last) { tmp = self->last; Py_INCREF(last); self->last = last; Py_DECREF(tmp); } return 0; } With these changes, we can assure that the ‘first’ and ‘last’ members are never ‘NULL’ so we can remove checks for ‘NULL’ values in almost all cases. This means that most of the *note Py_XDECREF(): 268. calls can be converted to *note Py_DECREF(): 266. calls. The only place we can’t change these calls is in the ‘tp_dealloc’ implementation, where there is the possibility that the initialization of these members failed in ‘tp_new’. We also rename the module initialization function and module name in the initialization function, as we did before, and we add an extra definition to the ‘setup.py’ file. ---------- Footnotes ---------- (1) (3) We now know that the first and last members are strings, so perhaps we could be less careful about decrementing their reference counts, however, we accept instances of string subclasses. Even though deallocating normal strings won’t call back into our objects, we can’t guarantee that deallocating an instance of a string subclass won’t call back into our objects.  File: python.info, Node: Supporting cyclic garbage collection, Next: Subclassing other types, Prev: Providing finer control over data attributes, Up: Defining Extension Types Tutorial 6.2.2.4 Supporting cyclic garbage collection ............................................ Python has a *note cyclic garbage collector (GC): f9f. that can identify unneeded objects even when their reference counts are not zero. This can happen when objects are involved in cycles. For example, consider: >>> l = [] >>> l.append(l) >>> del l In this example, we create a list that contains itself. When we delete it, it still has a reference from itself. Its reference count doesn’t drop to zero. Fortunately, Python’s cyclic garbage collector will eventually figure out that the list is garbage and free it. In the second version of the ‘Custom’ example, we allowed any kind of object to be stored in the ‘first’ or ‘last’ attributes (1). Besides, in the second and third versions, we allowed subclassing ‘Custom’, and subclasses may add arbitrary attributes. For any of those two reasons, ‘Custom’ objects can participate in cycles: >>> import custom3 >>> class Derived(custom3.Custom): pass ... >>> n = Derived() >>> n.some_attribute = n To allow a ‘Custom’ instance participating in a reference cycle to be properly detected and collected by the cyclic GC, our ‘Custom’ type needs to fill two additional slots and to enable a flag that enables these slots: #define PY_SSIZE_T_CLEAN #include <Python.h> #include "structmember.h" typedef struct { PyObject_HEAD PyObject *first; /* first name */ PyObject *last; /* last name */ int number; } CustomObject; static int Custom_traverse(CustomObject *self, visitproc visit, void *arg) { Py_VISIT(self->first); Py_VISIT(self->last); return 0; } static int Custom_clear(CustomObject *self) { Py_CLEAR(self->first); Py_CLEAR(self->last); return 0; } static void Custom_dealloc(CustomObject *self) { PyObject_GC_UnTrack(self); Custom_clear(self); Py_TYPE(self)->tp_free((PyObject *) self); } static PyObject * Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds) { CustomObject *self; self = (CustomObject *) type->tp_alloc(type, 0); if (self != NULL) { self->first = PyUnicode_FromString(""); if (self->first == NULL) { Py_DECREF(self); return NULL; } self->last = PyUnicode_FromString(""); if (self->last == NULL) { Py_DECREF(self); return NULL; } self->number = 0; } return (PyObject *) self; } static int Custom_init(CustomObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"first", "last", "number", NULL}; PyObject *first = NULL, *last = NULL, *tmp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist, &first, &last, &self->number)) return -1; if (first) { tmp = self->first; Py_INCREF(first); self->first = first; Py_DECREF(tmp); } if (last) { tmp = self->last; Py_INCREF(last); self->last = last; Py_DECREF(tmp); } return 0; } static PyMemberDef Custom_members[] = { {"number", T_INT, offsetof(CustomObject, number), 0, "custom number"}, {NULL} /* Sentinel */ }; static PyObject * Custom_getfirst(CustomObject *self, void *closure) { Py_INCREF(self->first); return self->first; } static int Custom_setfirst(CustomObject *self, PyObject *value, void *closure) { if (value == NULL) { PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute"); return -1; } if (!PyUnicode_Check(value)) { PyErr_SetString(PyExc_TypeError, "The first attribute value must be a string"); return -1; } Py_INCREF(value); Py_CLEAR(self->first); self->first = value; return 0; } static PyObject * Custom_getlast(CustomObject *self, void *closure) { Py_INCREF(self->last); return self->last; } static int Custom_setlast(CustomObject *self, PyObject *value, void *closure) { if (value == NULL) { PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute"); return -1; } if (!PyUnicode_Check(value)) { PyErr_SetString(PyExc_TypeError, "The last attribute value must be a string"); return -1; } Py_INCREF(value); Py_CLEAR(self->last); self->last = value; return 0; } static PyGetSetDef Custom_getsetters[] = { {"first", (getter) Custom_getfirst, (setter) Custom_setfirst, "first name", NULL}, {"last", (getter) Custom_getlast, (setter) Custom_setlast, "last name", NULL}, {NULL} /* Sentinel */ }; static PyObject * Custom_name(CustomObject *self, PyObject *Py_UNUSED(ignored)) { return PyUnicode_FromFormat("%S %S", self->first, self->last); } static PyMethodDef Custom_methods[] = { {"name", (PyCFunction) Custom_name, METH_NOARGS, "Return the name, combining the first and last name" }, {NULL} /* Sentinel */ }; static PyTypeObject CustomType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "custom4.Custom", .tp_doc = "Custom objects", .tp_basicsize = sizeof(CustomObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, .tp_new = Custom_new, .tp_init = (initproc) Custom_init, .tp_dealloc = (destructor) Custom_dealloc, .tp_traverse = (traverseproc) Custom_traverse, .tp_clear = (inquiry) Custom_clear, .tp_members = Custom_members, .tp_methods = Custom_methods, .tp_getset = Custom_getsetters, }; static PyModuleDef custommodule = { PyModuleDef_HEAD_INIT, .m_name = "custom4", .m_doc = "Example module that creates an extension type.", .m_size = -1, }; PyMODINIT_FUNC PyInit_custom4(void) { PyObject *m; if (PyType_Ready(&CustomType) < 0) return NULL; m = PyModule_Create(&custommodule); if (m == NULL) return NULL; Py_INCREF(&CustomType); if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) { Py_DECREF(&CustomType); Py_DECREF(m); return NULL; } return m; } First, the traversal method lets the cyclic GC know about subobjects that could participate in cycles: static int Custom_traverse(CustomObject *self, visitproc visit, void *arg) { int vret; if (self->first) { vret = visit(self->first, arg); if (vret != 0) return vret; } if (self->last) { vret = visit(self->last, arg); if (vret != 0) return vret; } return 0; } For each subobject that can participate in cycles, we need to call the ‘visit()’ function, which is passed to the traversal method. The ‘visit()’ function takes as arguments the subobject and the extra argument `arg' passed to the traversal method. It returns an integer value that must be returned if it is non-zero. Python provides a *note Py_VISIT(): 388c. macro that automates calling visit functions. With *note Py_VISIT(): 388c, we can minimize the amount of boilerplate in ‘Custom_traverse’: static int Custom_traverse(CustomObject *self, visitproc visit, void *arg) { Py_VISIT(self->first); Py_VISIT(self->last); return 0; } Note: The *note tp_traverse: 33e8. implementation must name its arguments exactly `visit' and `arg' in order to use *note Py_VISIT(): 388c. Second, we need to provide a method for clearing any subobjects that can participate in cycles: static int Custom_clear(CustomObject *self) { Py_CLEAR(self->first); Py_CLEAR(self->last); return 0; } Notice the use of the *note Py_CLEAR(): 388d. macro. It is the recommended and safe way to clear data attributes of arbitrary types while decrementing their reference counts. If you were to call *note Py_XDECREF(): 268. instead on the attribute before setting it to ‘NULL’, there is a possibility that the attribute’s destructor would call back into code that reads the attribute again (`especially' if there is a reference cycle). Note: You could emulate *note Py_CLEAR(): 388d. by writing: PyObject *tmp; tmp = self->first; self->first = NULL; Py_XDECREF(tmp); Nevertheless, it is much easier and less error-prone to always use *note Py_CLEAR(): 388d. when deleting an attribute. Don’t try to micro-optimize at the expense of robustness! The deallocator ‘Custom_dealloc’ may call arbitrary code when clearing attributes. It means the circular GC can be triggered inside the function. Since the GC assumes reference count is not zero, we need to untrack the object from the GC by calling *note PyObject_GC_UnTrack(): e45. before clearing members. Here is our reimplemented deallocator using *note PyObject_GC_UnTrack(): e45. and ‘Custom_clear’: static void Custom_dealloc(CustomObject *self) { PyObject_GC_UnTrack(self); Custom_clear(self); Py_TYPE(self)->tp_free((PyObject *) self); } Finally, we add the *note Py_TPFLAGS_HAVE_GC: 388e. flag to the class flags: .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, That’s pretty much it. If we had written custom *note tp_alloc: 3881. or *note tp_free: 3880. handlers, we’d need to modify them for cyclic garbage collection. Most extensions will use the versions automatically provided. ---------- Footnotes ---------- (1) (4) Also, even with our attributes restricted to strings instances, the user could pass arbitrary *note str: 330. subclasses and therefore still create reference cycles.  File: python.info, Node: Subclassing other types, Prev: Supporting cyclic garbage collection, Up: Defining Extension Types Tutorial 6.2.2.5 Subclassing other types ............................... It is possible to create new extension types that are derived from existing types. It is easiest to inherit from the built in types, since an extension can easily use the *note PyTypeObject: 2d6. it needs. It can be difficult to share these *note PyTypeObject: 2d6. structures between extension modules. In this example we will create a ‘SubList’ type that inherits from the built-in *note list: 262. type. The new type will be completely compatible with regular lists, but will have an additional ‘increment()’ method that increases an internal counter: >>> import sublist >>> s = sublist.SubList(range(3)) >>> s.extend(s) >>> print(len(s)) 6 >>> print(s.increment()) 1 >>> print(s.increment()) 2 #define PY_SSIZE_T_CLEAN #include <Python.h> typedef struct { PyListObject list; int state; } SubListObject; static PyObject * SubList_increment(SubListObject *self, PyObject *unused) { self->state++; return PyLong_FromLong(self->state); } static PyMethodDef SubList_methods[] = { {"increment", (PyCFunction) SubList_increment, METH_NOARGS, PyDoc_STR("increment state counter")}, {NULL}, }; static int SubList_init(SubListObject *self, PyObject *args, PyObject *kwds) { if (PyList_Type.tp_init((PyObject *) self, args, kwds) < 0) return -1; self->state = 0; return 0; } static PyTypeObject SubListType = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "sublist.SubList", .tp_doc = "SubList objects", .tp_basicsize = sizeof(SubListObject), .tp_itemsize = 0, .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, .tp_init = (initproc) SubList_init, .tp_methods = SubList_methods, }; static PyModuleDef sublistmodule = { PyModuleDef_HEAD_INIT, .m_name = "sublist", .m_doc = "Example module that creates an extension type.", .m_size = -1, }; PyMODINIT_FUNC PyInit_sublist(void) { PyObject *m; SubListType.tp_base = &PyList_Type; if (PyType_Ready(&SubListType) < 0) return NULL; m = PyModule_Create(&sublistmodule); if (m == NULL) return NULL; Py_INCREF(&SubListType); if (PyModule_AddObject(m, "SubList", (PyObject *) &SubListType) < 0) { Py_DECREF(&SubListType); Py_DECREF(m); return NULL; } return m; } As you can see, the source code closely resembles the ‘Custom’ examples in previous sections. We will break down the main differences between them. typedef struct { PyListObject list; int state; } SubListObject; The primary difference for derived type objects is that the base type’s object structure must be the first value. The base type will already include the *note PyObject_HEAD(): c72. at the beginning of its structure. When a Python object is a ‘SubList’ instance, its ‘PyObject *’ pointer can be safely cast to both ‘PyListObject *’ and ‘SubListObject *’: static int SubList_init(SubListObject *self, PyObject *args, PyObject *kwds) { if (PyList_Type.tp_init((PyObject *) self, args, kwds) < 0) return -1; self->state = 0; return 0; } We see above how to call through to the *note __init__: d5e. method of the base type. This pattern is important when writing a type with custom *note tp_new: 387c. and *note tp_dealloc: 387f. members. The *note tp_new: 387c. handler should not actually create the memory for the object with its *note tp_alloc: 3881, but let the base class handle it by calling its own *note tp_new: 387c. The *note PyTypeObject: 2d6. struct supports a *note tp_base: 3890. specifying the type’s concrete base class. Due to cross-platform compiler issues, you can’t fill that field directly with a reference to *note PyList_Type: 3891.; it should be done later in the module initialization function: PyMODINIT_FUNC PyInit_sublist(void) { PyObject* m; SubListType.tp_base = &PyList_Type; if (PyType_Ready(&SubListType) < 0) return NULL; m = PyModule_Create(&sublistmodule); if (m == NULL) return NULL; Py_INCREF(&SubListType); if (PyModule_AddObject(m, "SubList", (PyObject *) &SubListType) < 0) { Py_DECREF(&SubListType); Py_DECREF(m); return NULL; } return m; } Before calling *note PyType_Ready(): 3882, the type structure must have the *note tp_base: 3890. slot filled in. When we are deriving an existing type, it is not necessary to fill out the *note tp_alloc: 3881. slot with *note PyType_GenericNew(): 387d. – the allocation function from the base type will be inherited. After that, calling *note PyType_Ready(): 3882. and adding the type object to the module is the same as with the basic ‘Custom’ examples.  File: python.info, Node: Defining Extension Types Assorted Topics, Next: Building C and C++ Extensions, Prev: Defining Extension Types Tutorial, Up: Creating extensions without third party tools 6.2.3 Defining Extension Types: Assorted Topics ----------------------------------------------- This section aims to give a quick fly-by on the various type methods you can implement and what they do. Here is the definition of *note PyTypeObject: 2d6, with some fields only used in debug builds omitted: typedef struct _typeobject { PyObject_VAR_HEAD const char *tp_name; /* For printing, in format "<module>.<name>" */ Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */ /* Methods to implement standard operations */ destructor tp_dealloc; Py_ssize_t tp_vectorcall_offset; getattrfunc tp_getattr; setattrfunc tp_setattr; PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2) or tp_reserved (Python 3) */ reprfunc tp_repr; /* Method suites for standard classes */ PyNumberMethods *tp_as_number; PySequenceMethods *tp_as_sequence; PyMappingMethods *tp_as_mapping; /* More standard operations (here for binary compatibility) */ hashfunc tp_hash; ternaryfunc tp_call; reprfunc tp_str; getattrofunc tp_getattro; setattrofunc tp_setattro; /* Functions to access object as input/output buffer */ PyBufferProcs *tp_as_buffer; /* Flags to define presence of optional/expanded features */ unsigned long tp_flags; const char *tp_doc; /* Documentation string */ /* call function for all accessible objects */ traverseproc tp_traverse; /* delete references to contained objects */ inquiry tp_clear; /* rich comparisons */ richcmpfunc tp_richcompare; /* weak reference enabler */ Py_ssize_t tp_weaklistoffset; /* Iterators */ getiterfunc tp_iter; iternextfunc tp_iternext; /* Attribute descriptor and subclassing stuff */ struct PyMethodDef *tp_methods; struct PyMemberDef *tp_members; struct PyGetSetDef *tp_getset; struct _typeobject *tp_base; PyObject *tp_dict; descrgetfunc tp_descr_get; descrsetfunc tp_descr_set; Py_ssize_t tp_dictoffset; initproc tp_init; allocfunc tp_alloc; newfunc tp_new; freefunc tp_free; /* Low-level free-memory routine */ inquiry tp_is_gc; /* For PyObject_IS_GC */ PyObject *tp_bases; PyObject *tp_mro; /* method resolution order */ PyObject *tp_cache; PyObject *tp_subclasses; PyObject *tp_weaklist; destructor tp_del; /* Type attribute cache version tag. Added in version 2.6 */ unsigned int tp_version_tag; destructor tp_finalize; } PyTypeObject; Now that’s a `lot' of methods. Don’t worry too much though – if you have a type you want to define, the chances are very good that you will only implement a handful of these. As you probably expect by now, we’re going to go over this and give more information about the various handlers. We won’t go in the order they are defined in the structure, because there is a lot of historical baggage that impacts the ordering of the fields. It’s often easiest to find an example that includes the fields you need and then change the values to suit your new type. const char *tp_name; /* For printing */ The name of the type – as mentioned in the previous chapter, this will appear in various places, almost entirely for diagnostic purposes. Try to choose something that will be helpful in such a situation! Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */ These fields tell the runtime how much memory to allocate when new objects of this type are created. Python has some built-in support for variable length structures (think: strings, tuples) which is where the *note tp_itemsize: 3878. field comes in. This will be dealt with later. const char *tp_doc; Here you can put a string (or its address) that you want returned when the Python script references ‘obj.__doc__’ to retrieve the doc string. Now we come to the basic type methods – the ones most extension types will implement. * Menu: * Finalization and De-allocation:: * Object Presentation:: * Attribute Management:: * Object Comparison:: * Abstract Protocol Support:: * Weak Reference Support:: * More Suggestions::  File: python.info, Node: Finalization and De-allocation, Next: Object Presentation, Up: Defining Extension Types Assorted Topics 6.2.3.1 Finalization and De-allocation ...................................... destructor tp_dealloc; This function is called when the reference count of the instance of your type is reduced to zero and the Python interpreter wants to reclaim it. If your type has memory to free or other clean-up to perform, you can put it here. The object itself needs to be freed here as well. Here is an example of this function: static void newdatatype_dealloc(newdatatypeobject *obj) { free(obj->obj_UnderlyingDatatypePtr); Py_TYPE(obj)->tp_free(obj); } One important requirement of the deallocator function is that it leaves any pending exceptions alone. This is important since deallocators are frequently called as the interpreter unwinds the Python stack; when the stack is unwound due to an exception (rather than normal returns), nothing is done to protect the deallocators from seeing that an exception has already been set. Any actions which a deallocator performs which may cause additional Python code to be executed may detect that an exception has been set. This can lead to misleading errors from the interpreter. The proper way to protect against this is to save a pending exception before performing the unsafe action, and restoring it when done. This can be done using the *note PyErr_Fetch(): 96a. and *note PyErr_Restore(): 3897. functions: static void my_dealloc(PyObject *obj) { MyObject *self = (MyObject *) obj; PyObject *cbresult; if (self->my_callback != NULL) { PyObject *err_type, *err_value, *err_traceback; /* This saves the current exception state */ PyErr_Fetch(&err_type, &err_value, &err_traceback); cbresult = PyObject_CallObject(self->my_callback, NULL); if (cbresult == NULL) PyErr_WriteUnraisable(self->my_callback); else Py_DECREF(cbresult); /* This restores the saved exception state */ PyErr_Restore(err_type, err_value, err_traceback); Py_DECREF(self->my_callback); } Py_TYPE(obj)->tp_free((PyObject*)self); } Note: There are limitations to what you can safely do in a deallocator function. First, if your type supports garbage collection (using *note tp_traverse: 33e8. and/or *note tp_clear: 3898.), some of the object’s members can have been cleared or finalized by the time *note tp_dealloc: 387f. is called. Second, in *note tp_dealloc: 387f, your object is in an unstable state: its reference count is equal to zero. Any call to a non-trivial object or API (as in the example above) might end up calling *note tp_dealloc: 387f. again, causing a double free and a crash. Starting with Python 3.4, it is recommended not to put any complex finalization code in *note tp_dealloc: 387f, and instead use the new *note tp_finalize: 2d7. type method. See also ........ PEP 442(1) explains the new finalization scheme. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0442  File: python.info, Node: Object Presentation, Next: Attribute Management, Prev: Finalization and De-allocation, Up: Defining Extension Types Assorted Topics 6.2.3.2 Object Presentation ........................... In Python, there are two ways to generate a textual representation of an object: the *note repr(): 7cc. function, and the *note str(): 330. function. (The *note print(): 886. function just calls *note str(): 330.) These handlers are both optional. reprfunc tp_repr; reprfunc tp_str; The *note tp_repr: 389a. handler should return a string object containing a representation of the instance for which it is called. Here is a simple example: static PyObject * newdatatype_repr(newdatatypeobject * obj) { return PyUnicode_FromFormat("Repr-ified_newdatatype{{size:%d}}", obj->obj_UnderlyingDatatypePtr->size); } If no *note tp_repr: 389a. handler is specified, the interpreter will supply a representation that uses the type’s *note tp_name: 389b. and a uniquely-identifying value for the object. The *note tp_str: 389c. handler is to *note str(): 330. what the *note tp_repr: 389a. handler described above is to *note repr(): 7cc.; that is, it is called when Python code calls *note str(): 330. on an instance of your object. Its implementation is very similar to the *note tp_repr: 389a. function, but the resulting string is intended for human consumption. If *note tp_str: 389c. is not specified, the *note tp_repr: 389a. handler is used instead. Here is a simple example: static PyObject * newdatatype_str(newdatatypeobject * obj) { return PyUnicode_FromFormat("Stringified_newdatatype{{size:%d}}", obj->obj_UnderlyingDatatypePtr->size); }  File: python.info, Node: Attribute Management, Next: Object Comparison, Prev: Object Presentation, Up: Defining Extension Types Assorted Topics 6.2.3.3 Attribute Management ............................ For every object which can support attributes, the corresponding type must provide the functions that control how the attributes are resolved. There needs to be a function which can retrieve attributes (if any are defined), and another to set attributes (if setting attributes is allowed). Removing an attribute is a special case, for which the new value passed to the handler is ‘NULL’. Python supports two pairs of attribute handlers; a type that supports attributes only needs to implement the functions for one pair. The difference is that one pair takes the name of the attribute as a ‘char*’, while the other accepts a *note PyObject*: 4ba. Each type can use whichever pair makes more sense for the implementation’s convenience. getattrfunc tp_getattr; /* char * version */ setattrfunc tp_setattr; /* ... */ getattrofunc tp_getattro; /* PyObject * version */ setattrofunc tp_setattro; If accessing attributes of an object is always a simple operation (this will be explained shortly), there are generic implementations which can be used to provide the *note PyObject*: 4ba. version of the attribute management functions. The actual need for type-specific attribute handlers almost completely disappeared starting with Python 2.2, though there are many examples which have not been updated to use some of the new generic mechanism that is available. * Menu: * Generic Attribute Management:: * Type-specific Attribute Management::  File: python.info, Node: Generic Attribute Management, Next: Type-specific Attribute Management, Up: Attribute Management 6.2.3.4 Generic Attribute Management .................................... Most extension types only use `simple' attributes. So, what makes the attributes simple? There are only a couple of conditions that must be met: 1. The name of the attributes must be known when *note PyType_Ready(): 3882. is called. 2. No special processing is needed to record that an attribute was looked up or set, nor do actions need to be taken based on the value. Note that this list does not place any restrictions on the values of the attributes, when the values are computed, or how relevant data is stored. When *note PyType_Ready(): 3882. is called, it uses three tables referenced by the type object to create *note descriptor: 12b0.s which are placed in the dictionary of the type object. Each descriptor controls access to one attribute of the instance object. Each of the tables is optional; if all three are ‘NULL’, instances of the type will only have attributes that are inherited from their base type, and should leave the *note tp_getattro: 389f. and *note tp_setattro: 38a0. fields ‘NULL’ as well, allowing the base type to handle attributes. The tables are declared as three fields of the type object: struct PyMethodDef *tp_methods; struct PyMemberDef *tp_members; struct PyGetSetDef *tp_getset; If *note tp_methods: 3886. is not ‘NULL’, it must refer to an array of *note PyMethodDef: e1b. structures. Each entry in the table is an instance of this structure: typedef struct PyMethodDef { const char *ml_name; /* method name */ PyCFunction ml_meth; /* implementation function */ int ml_flags; /* flags */ const char *ml_doc; /* docstring */ } PyMethodDef; One entry should be defined for each method provided by the type; no entries are needed for methods inherited from a base type. One additional entry is needed at the end; it is a sentinel that marks the end of the array. The ‘ml_name’ field of the sentinel must be ‘NULL’. The second table is used to define attributes which map directly to data stored in the instance. A variety of primitive C types are supported, and access may be read-only or read-write. The structures in the table are defined as: typedef struct PyMemberDef { const char *name; int type; int offset; int flags; const char *doc; } PyMemberDef; For each entry in the table, a *note descriptor: 12b0. will be constructed and added to the type which will be able to extract a value from the instance structure. The *note type: 608. field should contain one of the type codes defined in the ‘structmember.h’ header; the value will be used to determine how to convert Python values to and from C values. The ‘flags’ field is used to store flags which control how the attribute can be accessed. The following flag constants are defined in ‘structmember.h’; they may be combined using bitwise-OR. Constant Meaning ----------------------------------------------------------------------------------- ‘READONLY’ Never writable. ‘READ_RESTRICTED’ Not readable in restricted mode. ‘WRITE_RESTRICTED’ Not writable in restricted mode. ‘RESTRICTED’ Not readable or writable in restricted mode. An interesting advantage of using the *note tp_members: 3884. table to build descriptors that are used at runtime is that any attribute defined this way can have an associated doc string simply by providing the text in the table. An application can use the introspection API to retrieve the descriptor from the class object, and get the doc string using its ‘__doc__’ attribute. As with the *note tp_methods: 3886. table, a sentinel entry with a ‘name’ value of ‘NULL’ is required.  File: python.info, Node: Type-specific Attribute Management, Prev: Generic Attribute Management, Up: Attribute Management 6.2.3.5 Type-specific Attribute Management .......................................... For simplicity, only the ‘char*’ version will be demonstrated here; the type of the name parameter is the only difference between the ‘char*’ and *note PyObject*: 4ba. flavors of the interface. This example effectively does the same thing as the generic example above, but does not use the generic support added in Python 2.2. It explains how the handler functions are called, so that if you do need to extend their functionality, you’ll understand what needs to be done. The *note tp_getattr: 38a2. handler is called when the object requires an attribute look-up. It is called in the same situations where the *note __getattr__(): 31a. method of a class would be called. Here is an example: static PyObject * newdatatype_getattr(newdatatypeobject *obj, char *name) { if (strcmp(name, "data") == 0) { return PyLong_FromLong(obj->data); } PyErr_Format(PyExc_AttributeError, "'%.50s' object has no attribute '%.400s'", tp->tp_name, name); return NULL; } The *note tp_setattr: 38a3. handler is called when the *note __setattr__(): e2c. or *note __delattr__(): 10d1. method of a class instance would be called. When an attribute should be deleted, the third parameter will be ‘NULL’. Here is an example that simply raises an exception; if this were really all you wanted, the *note tp_setattr: 38a3. handler should be set to ‘NULL’. static int newdatatype_setattr(newdatatypeobject *obj, char *name, PyObject *v) { PyErr_Format(PyExc_RuntimeError, "Read-only attribute: %s", name); return -1; }  File: python.info, Node: Object Comparison, Next: Abstract Protocol Support, Prev: Attribute Management, Up: Defining Extension Types Assorted Topics 6.2.3.6 Object Comparison ......................... richcmpfunc tp_richcompare; The *note tp_richcompare: 38a5. handler is called when comparisons are needed. It is analogous to the *note rich comparison methods: 10da, like *note __lt__(): c34, and also called by *note PyObject_RichCompare(): 38a6. and *note PyObject_RichCompareBool(): 38a7. This function is called with two Python objects and the operator as arguments, where the operator is one of ‘Py_EQ’, ‘Py_NE’, ‘Py_LE’, ‘Py_GT’, ‘Py_LT’ or ‘Py_GT’. It should compare the two objects with respect to the specified operator and return ‘Py_True’ or ‘Py_False’ if the comparison is successful, ‘Py_NotImplemented’ to indicate that comparison is not implemented and the other object’s comparison method should be tried, or ‘NULL’ if an exception was set. Here is a sample implementation, for a datatype that is considered equal if the size of an internal pointer is equal: static PyObject * newdatatype_richcmp(PyObject *obj1, PyObject *obj2, int op) { PyObject *result; int c, size1, size2; /* code to make sure that both arguments are of type newdatatype omitted */ size1 = obj1->obj_UnderlyingDatatypePtr->size; size2 = obj2->obj_UnderlyingDatatypePtr->size; switch (op) { case Py_LT: c = size1 < size2; break; case Py_LE: c = size1 <= size2; break; case Py_EQ: c = size1 == size2; break; case Py_NE: c = size1 != size2; break; case Py_GT: c = size1 > size2; break; case Py_GE: c = size1 >= size2; break; } result = c ? Py_True : Py_False; Py_INCREF(result); return result; }  File: python.info, Node: Abstract Protocol Support, Next: Weak Reference Support, Prev: Object Comparison, Up: Defining Extension Types Assorted Topics 6.2.3.7 Abstract Protocol Support ................................. Python supports a variety of `abstract' ‘protocols;’ the specific interfaces provided to use these interfaces are documented in *note Abstract Objects Layer: 38a9. A number of these abstract interfaces were defined early in the development of the Python implementation. In particular, the number, mapping, and sequence protocols have been part of Python since the beginning. Other protocols have been added over time. For protocols which depend on several handler routines from the type implementation, the older protocols have been defined as optional blocks of handlers referenced by the type object. For newer protocols there are additional slots in the main type object, with a flag bit being set to indicate that the slots are present and should be checked by the interpreter. (The flag bit does not indicate that the slot values are non-‘NULL’. The flag may be set to indicate the presence of a slot, but a slot may still be unfilled.) PyNumberMethods *tp_as_number; PySequenceMethods *tp_as_sequence; PyMappingMethods *tp_as_mapping; If you wish your object to be able to act like a number, a sequence, or a mapping object, then you place the address of a structure that implements the C type *note PyNumberMethods: d81, *note PySequenceMethods: 38aa, or *note PyMappingMethods: 38ab, respectively. It is up to you to fill in this structure with appropriate values. You can find examples of the use of each of these in the ‘Objects’ directory of the Python source distribution. hashfunc tp_hash; This function, if you choose to provide it, should return a hash number for an instance of your data type. Here is a simple example: static Py_hash_t newdatatype_hash(newdatatypeobject *obj) { Py_hash_t result; result = obj->some_size + 32767 * obj->some_number; if (result == -1) result = -2; return result; } ‘Py_hash_t’ is a signed integer type with a platform-varying width. Returning ‘-1’ from *note tp_hash: 38ac. indicates an error, which is why you should be careful to avoid returning it when hash computation is successful, as seen above. ternaryfunc tp_call; This function is called when an instance of your data type is “called”, for example, if ‘obj1’ is an instance of your data type and the Python script contains ‘obj1('hello')’, the *note tp_call: 38ad. handler is invoked. This function takes three arguments: 1. `self' is the instance of the data type which is the subject of the call. If the call is ‘obj1('hello')’, then `self' is ‘obj1’. 2. `args' is a tuple containing the arguments to the call. You can use *note PyArg_ParseTuple(): 26a. to extract the arguments. 3. `kwds' is a dictionary of keyword arguments that were passed. If this is non-‘NULL’ and you support keyword arguments, use *note PyArg_ParseTupleAndKeywords(): 5ca. to extract the arguments. If you do not want to support keyword arguments and this is non-‘NULL’, raise a *note TypeError: 192. with a message saying that keyword arguments are not supported. Here is a toy ‘tp_call’ implementation: static PyObject * newdatatype_call(newdatatypeobject *self, PyObject *args, PyObject *kwds) { PyObject *result; const char *arg1; const char *arg2; const char *arg3; if (!PyArg_ParseTuple(args, "sss:call", &arg1, &arg2, &arg3)) { return NULL; } result = PyUnicode_FromFormat( "Returning -- value: [%d] arg1: [%s] arg2: [%s] arg3: [%s]\n", obj->obj_UnderlyingDatatypePtr->size, arg1, arg2, arg3); return result; } /* Iterators */ getiterfunc tp_iter; iternextfunc tp_iternext; These functions provide support for the iterator protocol. Both handlers take exactly one parameter, the instance for which they are being called, and return a new reference. In the case of an error, they should set an exception and return ‘NULL’. *note tp_iter: e30. corresponds to the Python *note __iter__(): 50f. method, while *note tp_iternext: e31. corresponds to the Python *note __next__(): c64. method. Any *note iterable: bac. object must implement the *note tp_iter: e30. handler, which must return an *note iterator: 112e. object. Here the same guidelines apply as for Python classes: * For collections (such as lists and tuples) which can support multiple independent iterators, a new iterator should be created and returned by each call to *note tp_iter: e30. * Objects which can only be iterated over once (usually due to side effects of iteration, such as file objects) can implement *note tp_iter: e30. by returning a new reference to themselves – and should also therefore implement the *note tp_iternext: e31. handler. Any *note iterator: 112e. object should implement both *note tp_iter: e30. and *note tp_iternext: e31. An iterator’s *note tp_iter: e30. handler should return a new reference to the iterator. Its *note tp_iternext: e31. handler should return a new reference to the next object in the iteration, if there is one. If the iteration has reached the end, *note tp_iternext: e31. may return ‘NULL’ without setting an exception, or it may set *note StopIteration: 486. `in addition' to returning ‘NULL’; avoiding the exception can yield slightly better performance. If an actual error occurs, *note tp_iternext: e31. should always set an exception and return ‘NULL’.  File: python.info, Node: Weak Reference Support, Next: More Suggestions, Prev: Abstract Protocol Support, Up: Defining Extension Types Assorted Topics 6.2.3.8 Weak Reference Support .............................. One of the goals of Python’s weak reference implementation is to allow any type to participate in the weak reference mechanism without incurring the overhead on performance-critical objects (such as numbers). See also ........ Documentation for the *note weakref: 128. module. For an object to be weakly referencable, the extension type must do two things: 1. Include a *note PyObject*: 4ba. field in the C object structure dedicated to the weak reference mechanism. The object’s constructor should leave it ‘NULL’ (which is automatic when using the default *note tp_alloc: 3881.). 2. Set the *note tp_weaklistoffset: 38af. type member to the offset of the aforementioned field in the C object structure, so that the interpreter knows how to access and modify that field. Concretely, here is how a trivial object structure would be augmented with the required field: typedef struct { PyObject_HEAD PyObject *weakreflist; /* List of weak references */ } TrivialObject; And the corresponding member in the statically-declared type object: static PyTypeObject TrivialType = { PyVarObject_HEAD_INIT(NULL, 0) /* ... other members omitted for brevity ... */ .tp_weaklistoffset = offsetof(TrivialObject, weakreflist), }; The only further addition is that ‘tp_dealloc’ needs to clear any weak references (by calling ‘PyObject_ClearWeakRefs()’) if the field is non-‘NULL’: static void Trivial_dealloc(TrivialObject *self) { /* Clear weakrefs first before calling any destructors */ if (self->weakreflist != NULL) PyObject_ClearWeakRefs((PyObject *) self); /* ... remainder of destruction code omitted for brevity ... */ Py_TYPE(self)->tp_free((PyObject *) self); }  File: python.info, Node: More Suggestions, Prev: Weak Reference Support, Up: Defining Extension Types Assorted Topics 6.2.3.9 More Suggestions ........................ In order to learn how to implement any specific method for your new data type, get the *note CPython: 10d7. source code. Go to the ‘Objects’ directory, then search the C source files for ‘tp_’ plus the function you want (for example, ‘tp_richcompare’). You will find examples of the function you want to implement. When you need to verify that an object is a concrete instance of the type you are implementing, use the *note PyObject_TypeCheck(): 38b1. function. A sample of its use might be something like the following: if (!PyObject_TypeCheck(some_object, &MyType)) { PyErr_SetString(PyExc_TypeError, "arg #1 not a mything"); return NULL; } See also ........ Download CPython source releases. ‘https://www.python.org/downloads/source/’ The CPython project on GitHub, where the CPython source code is developed. ‘https://github.com/python/cpython’  File: python.info, Node: Building C and C++ Extensions, Next: Building C and C++ Extensions on Windows, Prev: Defining Extension Types Assorted Topics, Up: Creating extensions without third party tools 6.2.4 Building C and C++ Extensions ----------------------------------- A C extension for CPython is a shared library (e.g. a ‘.so’ file on Linux, ‘.pyd’ on Windows), which exports an `initialization function'. To be importable, the shared library must be available on *note PYTHONPATH: 953, and must be named after the module name, with an appropriate extension. When using distutils, the correct filename is generated automatically. The initialization function has the signature: -- C Function: PyObject* PyInit_modulename (void) It returns either a fully-initialized module, or a *note PyModuleDef: 3888. instance. See *note Initializing C modules: 38b5. for details. For modules with ASCII-only names, the function must be named ‘PyInit_<modulename>’, with ‘<modulename>’ replaced by the name of the module. When using *note Multi-phase initialization: 38b6, non-ASCII module names are allowed. In this case, the initialization function name is ‘PyInitU_<modulename>’, with ‘<modulename>’ encoded using Python’s `punycode' encoding with hyphens replaced by underscores. In Python: def initfunc_name(name): try: suffix = b'_' + name.encode('ascii') except UnicodeEncodeError: suffix = b'U_' + name.encode('punycode').replace(b'-', b'_') return b'PyInit' + suffix It is possible to export multiple modules from a single shared library by defining multiple initialization functions. However, importing them requires using symbolic links or a custom importer, because by default only the function corresponding to the filename is found. See the `“Multiple modules in one library”' section in PEP 489(1) for details. * Menu: * Building C and C++ Extensions with distutils:: * Distributing your extension modules:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0489  File: python.info, Node: Building C and C++ Extensions with distutils, Next: Distributing your extension modules, Up: Building C and C++ Extensions 6.2.4.1 Building C and C++ Extensions with distutils .................................................... Extension modules can be built using distutils, which is included in Python. Since distutils also supports creation of binary packages, users don’t necessarily need a compiler and distutils to install the extension. A distutils package contains a driver script, ‘setup.py’. This is a plain Python file, which, in the most simple case, could look like this: from distutils.core import setup, Extension module1 = Extension('demo', sources = ['demo.c']) setup (name = 'PackageName', version = '1.0', description = 'This is a demo package', ext_modules = [module1]) With this ‘setup.py’, and a file ‘demo.c’, running python setup.py build will compile ‘demo.c’, and produce an extension module named ‘demo’ in the ‘build’ directory. Depending on the system, the module file will end up in a subdirectory ‘build/lib.system’, and may have a name like ‘demo.so’ or ‘demo.pyd’. In the ‘setup.py’, all execution is performed by calling the ‘setup’ function. This takes a variable number of keyword arguments, of which the example above uses only a subset. Specifically, the example specifies meta-information to build packages, and it specifies the contents of the package. Normally, a package will contain additional modules, like Python source modules, documentation, subpackages, etc. Please refer to the distutils documentation in *note Distributing Python Modules (Legacy version): 7f8. to learn more about the features of distutils; this section explains building extension modules only. It is common to pre-compute arguments to ‘setup()’, to better structure the driver script. In the example above, the ‘ext_modules’ argument to *note setup(): 38b8. is a list of extension modules, each of which is an instance of the ‘Extension’. In the example, the instance defines an extension named ‘demo’ which is build by compiling a single source file, ‘demo.c’. In many cases, building an extension is more complex, since additional preprocessor defines and libraries may be needed. This is demonstrated in the example below. from distutils.core import setup, Extension module1 = Extension('demo', define_macros = [('MAJOR_VERSION', '1'), ('MINOR_VERSION', '0')], include_dirs = ['/usr/local/include'], libraries = ['tcl83'], library_dirs = ['/usr/local/lib'], sources = ['demo.c']) setup (name = 'PackageName', version = '1.0', description = 'This is a demo package', author = 'Martin v. Loewis', author_email = 'martin@v.loewis.de', url = 'https://docs.python.org/extending/building', long_description = ''' This is really just a demo package. ''', ext_modules = [module1]) In this example, *note setup(): 38b8. is called with additional meta-information, which is recommended when distribution packages have to be built. For the extension itself, it specifies preprocessor defines, include directories, library directories, and libraries. Depending on the compiler, distutils passes this information in different ways to the compiler. For example, on Unix, this may result in the compilation commands gcc -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -fPIC -DMAJOR_VERSION=1 -DMINOR_VERSION=0 -I/usr/local/include -I/usr/local/include/python2.2 -c demo.c -o build/temp.linux-i686-2.2/demo.o gcc -shared build/temp.linux-i686-2.2/demo.o -L/usr/local/lib -ltcl83 -o build/lib.linux-i686-2.2/demo.so These lines are for demonstration purposes only; distutils users should trust that distutils gets the invocations right.  File: python.info, Node: Distributing your extension modules, Prev: Building C and C++ Extensions with distutils, Up: Building C and C++ Extensions 6.2.4.2 Distributing your extension modules ........................................... When an extension has been successfully built, there are three ways to use it. End-users will typically want to install the module, they do so by running python setup.py install Module maintainers should produce source packages; to do so, they run python setup.py sdist In some cases, additional files need to be included in a source distribution; this is done through a ‘MANIFEST.in’ file; see *note Specifying the files to distribute: 38bb. for details. If the source distribution has been built successfully, maintainers can also create binary distributions. Depending on the platform, one of the following commands can be used to do so. python setup.py bdist_wininst python setup.py bdist_rpm python setup.py bdist_dumb  File: python.info, Node: Building C and C++ Extensions on Windows, Prev: Building C and C++ Extensions, Up: Creating extensions without third party tools 6.2.5 Building C and C++ Extensions on Windows ---------------------------------------------- This chapter briefly explains how to create a Windows extension module for Python using Microsoft Visual C++, and follows with more detailed background information on how it works. The explanatory material is useful for both the Windows programmer learning to build Python extensions and the Unix programmer interested in producing software which can be successfully built on both Unix and Windows. Module authors are encouraged to use the distutils approach for building extension modules, instead of the one described in this section. You will still need the C compiler that was used to build Python; typically Microsoft Visual C++. Note: This chapter mentions a number of filenames that include an encoded Python version number. These filenames are represented with the version number shown as ‘XY’; in practice, ‘'X'’ will be the major version number and ‘'Y'’ will be the minor version number of the Python release you’re working with. For example, if you are using Python 2.2.1, ‘XY’ will actually be ‘22’. * Menu: * A Cookbook Approach:: * Differences Between Unix and Windows:: * Using DLLs in Practice::  File: python.info, Node: A Cookbook Approach, Next: Differences Between Unix and Windows, Up: Building C and C++ Extensions on Windows 6.2.5.1 A Cookbook Approach ........................... There are two approaches to building extension modules on Windows, just as there are on Unix: use the *note distutils: 39. package to control the build process, or do things manually. The distutils approach works well for most extensions; documentation on using *note distutils: 39. to build and package extension modules is available in *note Distributing Python Modules (Legacy version): 7f8. If you find you really need to do things manually, it may be instructive to study the project file for the winsound(1) standard library module. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/PCbuild/winsound.vcxproj  File: python.info, Node: Differences Between Unix and Windows, Next: Using DLLs in Practice, Prev: A Cookbook Approach, Up: Building C and C++ Extensions on Windows 6.2.5.2 Differences Between Unix and Windows ............................................ Unix and Windows use completely different paradigms for run-time loading of code. Before you try to build a module that can be dynamically loaded, be aware of how your system works. In Unix, a shared object (‘.so’) file contains code to be used by the program, and also the names of functions and data that it expects to find in the program. When the file is joined to the program, all references to those functions and data in the file’s code are changed to point to the actual locations in the program where the functions and data are placed in memory. This is basically a link operation. In Windows, a dynamic-link library (‘.dll’) file has no dangling references. Instead, an access to functions or data goes through a lookup table. So the DLL code does not have to be fixed up at runtime to refer to the program’s memory; instead, the code already uses the DLL’s lookup table, and the lookup table is modified at runtime to point to the functions and data. In Unix, there is only one type of library file (‘.a’) which contains code from several object files (‘.o’). During the link step to create a shared object file (‘.so’), the linker may find that it doesn’t know where an identifier is defined. The linker will look for it in the object files in the libraries; if it finds it, it will include all the code from that object file. In Windows, there are two types of library, a static library and an import library (both called ‘.lib’). A static library is like a Unix ‘.a’ file; it contains code to be included as necessary. An import library is basically used only to reassure the linker that a certain identifier is legal, and will be present in the program when the DLL is loaded. So the linker uses the information from the import library to build the lookup table for using identifiers that are not included in the DLL. When an application or a DLL is linked, an import library may be generated, which will need to be used for all future DLLs that depend on the symbols in the application or DLL. Suppose you are building two dynamic-load modules, B and C, which should share another block of code A. On Unix, you would `not' pass ‘A.a’ to the linker for ‘B.so’ and ‘C.so’; that would cause it to be included twice, so that B and C would each have their own copy. In Windows, building ‘A.dll’ will also build ‘A.lib’. You `do' pass ‘A.lib’ to the linker for B and C. ‘A.lib’ does not contain code; it just contains information which will be used at runtime to access A’s code. In Windows, using an import library is sort of like using ‘import spam’; it gives you access to spam’s names, but does not create a separate copy. On Unix, linking with a library is more like ‘from spam import *’; it does create a separate copy.  File: python.info, Node: Using DLLs in Practice, Prev: Differences Between Unix and Windows, Up: Building C and C++ Extensions on Windows 6.2.5.3 Using DLLs in Practice .............................. Windows Python is built in Microsoft Visual C++; using other compilers may or may not work (though Borland seems to). The rest of this section is MSVC++ specific. When creating DLLs in Windows, you must pass ‘pythonXY.lib’ to the linker. To build two DLLs, spam and ni (which uses C functions found in spam), you could use these commands: cl /LD /I/python/include spam.c ../libs/pythonXY.lib cl /LD /I/python/include ni.c spam.lib ../libs/pythonXY.lib The first command created three files: ‘spam.obj’, ‘spam.dll’ and ‘spam.lib’. ‘Spam.dll’ does not contain any Python functions (such as *note PyArg_ParseTuple(): 26a.), but it does know how to find the Python code thanks to ‘pythonXY.lib’. The second command created ‘ni.dll’ (and ‘.obj’ and ‘.lib’), which knows how to find the necessary functions from spam, and also from the Python executable. Not every identifier is exported to the lookup table. If you want any other modules (including Python) to be able to see your identifiers, you have to say ‘_declspec(dllexport)’, as in ‘void _declspec(dllexport) initspam(void)’ or ‘PyObject _declspec(dllexport) *NiGetSpamData(void)’. Developer Studio will throw in a lot of import libraries that you do not really need, adding about 100K to your executable. To get rid of them, use the Project Settings dialog, Link tab, to specify `ignore default libraries'. Add the correct ‘msvcrtxx.lib’ to the list of libraries.  File: python.info, Node: Embedding the CPython runtime in a larger application, Prev: Creating extensions without third party tools, Up: Extending and Embedding the Python Interpreter 6.3 Embedding the CPython runtime in a larger application ========================================================= Sometimes, rather than creating an extension that runs inside the Python interpreter as the main application, it is desirable to instead embed the CPython runtime inside a larger application. This section covers some of the details involved in doing that successfully. * Menu: * Embedding Python in Another Application::  File: python.info, Node: Embedding Python in Another Application, Up: Embedding the CPython runtime in a larger application 6.3.1 Embedding Python in Another Application --------------------------------------------- The previous chapters discussed how to extend Python, that is, how to extend the functionality of Python by attaching a library of C functions to it. It is also possible to do it the other way around: enrich your C/C++ application by embedding Python in it. Embedding provides your application with the ability to implement some of the functionality of your application in Python rather than C or C++. This can be used for many purposes; one example would be to allow users to tailor the application to their needs by writing some scripts in Python. You can also use it yourself if some of the functionality can be written in Python more easily. Embedding Python is similar to extending it, but not quite. The difference is that when you extend Python, the main program of the application is still the Python interpreter, while if you embed Python, the main program may have nothing to do with Python — instead, some parts of the application occasionally call the Python interpreter to run some Python code. So if you are embedding Python, you are providing your own main program. One of the things this main program has to do is initialize the Python interpreter. At the very least, you have to call the function *note Py_Initialize(): 439. There are optional calls to pass command line arguments to Python. Then later you can call the interpreter from any part of the application. There are several different ways to call the interpreter: you can pass a string containing Python statements to *note PyRun_SimpleString(): 38c8, or you can pass a stdio file pointer and a file name (for identification in error messages only) to *note PyRun_SimpleFile(): 38c9. You can also call the lower-level operations described in the previous chapters to construct and use Python objects. See also ........ *note Python/C API Reference Manual: e91. The details of Python’s C interface are given in this manual. A great deal of necessary information can be found here. * Menu: * Very High Level Embedding:: * Beyond Very High Level Embedding; An overview: Beyond Very High Level Embedding An overview. * Pure Embedding:: * Extending Embedded Python:: * Embedding Python in C++:: * Compiling and Linking under Unix-like systems::  File: python.info, Node: Very High Level Embedding, Next: Beyond Very High Level Embedding An overview, Up: Embedding Python in Another Application 6.3.1.1 Very High Level Embedding ................................. The simplest form of embedding Python is the use of the very high level interface. This interface is intended to execute a Python script without needing to interact with the application directly. This can for example be used to perform some operation on a file. #define PY_SSIZE_T_CLEAN #include <Python.h> int main(int argc, char *argv[]) { wchar_t *program = Py_DecodeLocale(argv[0], NULL); if (program == NULL) { fprintf(stderr, "Fatal error: cannot decode argv[0]\n"); exit(1); } Py_SetProgramName(program); /* optional but recommended */ Py_Initialize(); PyRun_SimpleString("from time import time,ctime\n" "print('Today is', ctime(time()))\n"); if (Py_FinalizeEx() < 0) { exit(120); } PyMem_RawFree(program); return 0; } The *note Py_SetProgramName(): 1031. function should be called before *note Py_Initialize(): 439. to inform the interpreter about paths to Python run-time libraries. Next, the Python interpreter is initialized with *note Py_Initialize(): 439, followed by the execution of a hard-coded Python script that prints the date and time. Afterwards, the *note Py_FinalizeEx(): 5c9. call shuts the interpreter down, followed by the end of the program. In a real program, you may want to get the Python script from another source, perhaps a text-editor routine, a file, or a database. Getting the Python code from a file can better be done by using the *note PyRun_SimpleFile(): 38c9. function, which saves you the trouble of allocating memory space and loading the file contents.  File: python.info, Node: Beyond Very High Level Embedding An overview, Next: Pure Embedding, Prev: Very High Level Embedding, Up: Embedding Python in Another Application 6.3.1.2 Beyond Very High Level Embedding: An overview ..................................................... The high level interface gives you the ability to execute arbitrary pieces of Python code from your application, but exchanging data values is quite cumbersome to say the least. If you want that, you should use lower level calls. At the cost of having to write more C code, you can achieve almost anything. It should be noted that extending Python and embedding Python is quite the same activity, despite the different intent. Most topics discussed in the previous chapters are still valid. To show this, consider what the extension code from Python to C really does: 1. Convert data values from Python to C, 2. Perform a function call to a C routine using the converted values, and 3. Convert the data values from the call from C to Python. When embedding Python, the interface code does: 1. Convert data values from C to Python, 2. Perform a function call to a Python interface routine using the converted values, and 3. Convert the data values from the call from Python to C. As you can see, the data conversion steps are simply swapped to accommodate the different direction of the cross-language transfer. The only difference is the routine that you call between both data conversions. When extending, you call a C routine, when embedding, you call a Python routine. This chapter will not discuss how to convert data from Python to C and vice versa. Also, proper use of references and dealing with errors is assumed to be understood. Since these aspects do not differ from extending the interpreter, you can refer to earlier chapters for the required information.  File: python.info, Node: Pure Embedding, Next: Extending Embedded Python, Prev: Beyond Very High Level Embedding An overview, Up: Embedding Python in Another Application 6.3.1.3 Pure Embedding ...................... The first program aims to execute a function in a Python script. Like in the section about the very high level interface, the Python interpreter does not directly interact with the application (but that will change in the next section). The code to run a function defined in a Python script is: #define PY_SSIZE_T_CLEAN #include <Python.h> int main(int argc, char *argv[]) { PyObject *pName, *pModule, *pFunc; PyObject *pArgs, *pValue; int i; if (argc < 3) { fprintf(stderr,"Usage: call pythonfile funcname [args]\n"); return 1; } Py_Initialize(); pName = PyUnicode_DecodeFSDefault(argv[1]); /* Error checking of pName left out */ pModule = PyImport_Import(pName); Py_DECREF(pName); if (pModule != NULL) { pFunc = PyObject_GetAttrString(pModule, argv[2]); /* pFunc is a new reference */ if (pFunc && PyCallable_Check(pFunc)) { pArgs = PyTuple_New(argc - 3); for (i = 0; i < argc - 3; ++i) { pValue = PyLong_FromLong(atoi(argv[i + 3])); if (!pValue) { Py_DECREF(pArgs); Py_DECREF(pModule); fprintf(stderr, "Cannot convert argument\n"); return 1; } /* pValue reference stolen here: */ PyTuple_SetItem(pArgs, i, pValue); } pValue = PyObject_CallObject(pFunc, pArgs); Py_DECREF(pArgs); if (pValue != NULL) { printf("Result of call: %ld\n", PyLong_AsLong(pValue)); Py_DECREF(pValue); } else { Py_DECREF(pFunc); Py_DECREF(pModule); PyErr_Print(); fprintf(stderr,"Call failed\n"); return 1; } } else { if (PyErr_Occurred()) PyErr_Print(); fprintf(stderr, "Cannot find function \"%s\"\n", argv[2]); } Py_XDECREF(pFunc); Py_DECREF(pModule); } else { PyErr_Print(); fprintf(stderr, "Failed to load \"%s\"\n", argv[1]); return 1; } if (Py_FinalizeEx() < 0) { return 120; } return 0; } This code loads a Python script using ‘argv[1]’, and calls the function named in ‘argv[2]’. Its integer arguments are the other values of the ‘argv’ array. If you *note compile and link: 38d0. this program (let’s call the finished executable ‘call’), and use it to execute a Python script, such as: def multiply(a,b): print("Will compute", a, "times", b) c = 0 for i in range(0, a): c = c + b return c then the result should be: $ call multiply multiply 3 2 Will compute 3 times 2 Result of call: 6 Although the program is quite large for its functionality, most of the code is for data conversion between Python and C, and for error reporting. The interesting part with respect to embedding Python starts with Py_Initialize(); pName = PyUnicode_DecodeFSDefault(argv[1]); /* Error checking of pName left out */ pModule = PyImport_Import(pName); After initializing the interpreter, the script is loaded using *note PyImport_Import(): d5f. This routine needs a Python string as its argument, which is constructed using the *note PyUnicode_FromString(): 38d1. data conversion routine. pFunc = PyObject_GetAttrString(pModule, argv[2]); /* pFunc is a new reference */ if (pFunc && PyCallable_Check(pFunc)) { ... } Py_XDECREF(pFunc); Once the script is loaded, the name we’re looking for is retrieved using *note PyObject_GetAttrString(): 385b. If the name exists, and the object returned is callable, you can safely assume that it is a function. The program then proceeds by constructing a tuple of arguments as normal. The call to the Python function is then made with: pValue = PyObject_CallObject(pFunc, pArgs); Upon return of the function, ‘pValue’ is either ‘NULL’ or it contains a reference to the return value of the function. Be sure to release the reference after examining the value.  File: python.info, Node: Extending Embedded Python, Next: Embedding Python in C++, Prev: Pure Embedding, Up: Embedding Python in Another Application 6.3.1.4 Extending Embedded Python ................................. Until now, the embedded Python interpreter had no access to functionality from the application itself. The Python API allows this by extending the embedded interpreter. That is, the embedded interpreter gets extended with routines provided by the application. While it sounds complex, it is not so bad. Simply forget for a while that the application starts the Python interpreter. Instead, consider the application to be a set of subroutines, and write some glue code that gives Python access to those routines, just like you would write a normal Python extension. For example: static int numargs=0; /* Return the number of arguments of the application command line */ static PyObject* emb_numargs(PyObject *self, PyObject *args) { if(!PyArg_ParseTuple(args, ":numargs")) return NULL; return PyLong_FromLong(numargs); } static PyMethodDef EmbMethods[] = { {"numargs", emb_numargs, METH_VARARGS, "Return the number of arguments received by the process."}, {NULL, NULL, 0, NULL} }; static PyModuleDef EmbModule = { PyModuleDef_HEAD_INIT, "emb", NULL, -1, EmbMethods, NULL, NULL, NULL, NULL }; static PyObject* PyInit_emb(void) { return PyModule_Create(&EmbModule); } Insert the above code just above the ‘main()’ function. Also, insert the following two statements before the call to *note Py_Initialize(): 439.: numargs = argc; PyImport_AppendInittab("emb", &PyInit_emb); These two lines initialize the ‘numargs’ variable, and make the ‘emb.numargs()’ function accessible to the embedded Python interpreter. With these extensions, the Python script can do things like import emb print("Number of arguments", emb.numargs()) In a real application, the methods will expose an API of the application to Python.  File: python.info, Node: Embedding Python in C++, Next: Compiling and Linking under Unix-like systems, Prev: Extending Embedded Python, Up: Embedding Python in Another Application 6.3.1.5 Embedding Python in C++ ............................... It is also possible to embed Python in a C++ program; precisely how this is done will depend on the details of the C++ system used; in general you will need to write the main program in C++, and use the C++ compiler to compile and link your program. There is no need to recompile Python itself using C++.  File: python.info, Node: Compiling and Linking under Unix-like systems, Prev: Embedding Python in C++, Up: Embedding Python in Another Application 6.3.1.6 Compiling and Linking under Unix-like systems ..................................................... It is not necessarily trivial to find the right flags to pass to your compiler (and linker) in order to embed the Python interpreter into your application, particularly because Python needs to load library modules implemented as C dynamic extensions (‘.so’ files) linked against it. To find out the required compiler and linker flags, you can execute the ‘python`X.Y'-config’ script which is generated as part of the installation process (a ‘python3-config’ script may also be available). This script has several options, of which the following will be directly useful to you: * ‘pythonX.Y-config --cflags’ will give you the recommended flags when compiling: $ /opt/bin/python3.4-config --cflags -I/opt/include/python3.4m -I/opt/include/python3.4m -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes * ‘pythonX.Y-config --ldflags’ will give you the recommended flags when linking: $ /opt/bin/python3.4-config --ldflags -L/opt/lib/python3.4/config-3.4m -lpthread -ldl -lutil -lm -lpython3.4m -Xlinker -export-dynamic Note: To avoid confusion between several Python installations (and especially between the system Python and your own compiled Python), it is recommended that you use the absolute path to ‘python`X.Y'-config’, as in the above example. If this procedure doesn’t work for you (it is not guaranteed to work for all Unix-like platforms; however, we welcome *note bug reports: 38d7.) you will have to read your system’s documentation about dynamic linking and/or examine Python’s ‘Makefile’ (use *note sysconfig.get_makefile_filename(): 336f. to find its location) and compilation options. In this case, the *note sysconfig: fe. module is a useful tool to programmatically extract the configuration values that you will want to combine together. For example: >>> import sysconfig >>> sysconfig.get_config_var('LIBS') '-lpthread -ldl -lutil' >>> sysconfig.get_config_var('LINKFORSHARED') '-Xlinker -export-dynamic'  File: python.info, Node: Python/C API Reference Manual, Next: Distributing Python Modules, Prev: Extending and Embedding the Python Interpreter, Up: Top 7 Python/C API Reference Manual ******************************* This manual documents the API used by C and C++ programmers who want to write extension modules or embed Python. It is a companion to *note Extending and Embedding the Python Interpreter: e90, which describes the general principles of extension writing but does not document the API functions in detail. * Menu: * Introduction: Introduction<13>. * Stable Application Binary Interface:: * The Very High Level Layer:: * Reference Counting:: * Exception Handling:: * Utilities: Utilities<2>. * Abstract Objects Layer:: * Concrete Objects Layer:: * Initialization, Finalization, and Threads: Initialization Finalization and Threads. * Python Initialization Configuration:: * Memory Management:: * Object Implementation Support:: * API and ABI Versioning::  File: python.info, Node: Introduction<13>, Next: Stable Application Binary Interface, Up: Python/C API Reference Manual 7.1 Introduction ================ The Application Programmer’s Interface to Python gives C and C++ programmers access to the Python interpreter at a variety of levels. The API is equally usable from C++, but for brevity it is generally referred to as the Python/C API. There are two fundamentally different reasons for using the Python/C API. The first reason is to write `extension modules' for specific purposes; these are C modules that extend the Python interpreter. This is probably the most common use. The second reason is to use Python as a component in a larger application; this technique is generally referred to as `embedding' Python in an application. Writing an extension module is a relatively well-understood process, where a “cookbook” approach works well. There are several tools that automate the process to some extent. While people have embedded Python in other applications since its early existence, the process of embedding Python is less straightforward than writing an extension. Many API functions are useful independent of whether you’re embedding or extending Python; moreover, most applications that embed Python will need to provide a custom extension as well, so it’s probably a good idea to become familiar with writing an extension before attempting to embed Python in a real application. * Menu: * Coding standards:: * Include Files:: * Useful macros:: * Objects, Types and Reference Counts: Objects Types and Reference Counts. * Exceptions: Exceptions<18>. * Embedding Python: Embedding Python<2>. * Debugging Builds::  File: python.info, Node: Coding standards, Next: Include Files, Up: Introduction<13> 7.1.1 Coding standards ---------------------- If you’re writing C code for inclusion in CPython, you `must' follow the guidelines and standards defined in PEP 7(1). These guidelines apply regardless of the version of Python you are contributing to. Following these conventions is not necessary for your own third party extension modules, unless you eventually expect to contribute them to Python. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0007  File: python.info, Node: Include Files, Next: Useful macros, Prev: Coding standards, Up: Introduction<13> 7.1.2 Include Files ------------------- All function, type and macro definitions needed to use the Python/C API are included in your code by the following line: #define PY_SSIZE_T_CLEAN #include <Python.h> This implies inclusion of the following standard headers: ‘<stdio.h>’, ‘<string.h>’, ‘<errno.h>’, ‘<limits.h>’, ‘<assert.h>’ and ‘<stdlib.h>’ (if available). Note: Since Python may define some pre-processor definitions which affect the standard headers on some systems, you `must' include ‘Python.h’ before any standard headers are included. It is recommended to always define ‘PY_SSIZE_T_CLEAN’ before including ‘Python.h’. See *note Parsing arguments and building values: 2d0. for a description of this macro. All user visible names defined by Python.h (except those defined by the included standard headers) have one of the prefixes ‘Py’ or ‘_Py’. Names beginning with ‘_Py’ are for internal use by the Python implementation and should not be used by extension writers. Structure member names do not have a reserved prefix. Note: User code should never define names that begin with ‘Py’ or ‘_Py’. This confuses the reader, and jeopardizes the portability of the user code to future Python versions, which may define additional names beginning with one of these prefixes. The header files are typically installed with Python. On Unix, these are located in the directories ‘`prefix'/include/pythonversion/’ and ‘`exec_prefix'/include/pythonversion/’, where ‘prefix’ and ‘exec_prefix’ are defined by the corresponding parameters to Python’s ‘configure’ script and `version' is ‘'%d.%d' % sys.version_info[:2]’. On Windows, the headers are installed in ‘`prefix'/include’, where ‘prefix’ is the installation directory specified to the installer. To include the headers, place both directories (if different) on your compiler’s search path for includes. Do `not' place the parent directories on the search path and then use ‘#include <pythonX.Y/Python.h>’; this will break on multi-platform builds since the platform independent headers under ‘prefix’ include the platform specific headers from ‘exec_prefix’. C++ users should note that although the API is defined entirely using C, the header files properly declare the entry points to be ‘extern "C"’. As a result, there is no need to do anything special to use the API from C++.  File: python.info, Node: Useful macros, Next: Objects Types and Reference Counts, Prev: Include Files, Up: Introduction<13> 7.1.3 Useful macros ------------------- Several useful macros are defined in the Python header files. Many are defined closer to where they are useful (e.g. *note Py_RETURN_NONE: dd6.). Others of a more general utility are defined here. This is not necessarily a complete listing. -- C Macro: Py_UNREACHABLE () Use this when you have a code path that you do not expect to be reached. For example, in the ‘default:’ clause in a ‘switch’ statement for which all possible values are covered in ‘case’ statements. Use this in places where you might be tempted to put an ‘assert(0)’ or ‘abort()’ call. New in version 3.7. -- C Macro: Py_ABS (x) Return the absolute value of ‘x’. New in version 3.3. -- C Macro: Py_MIN (x, y) Return the minimum value between ‘x’ and ‘y’. New in version 3.3. -- C Macro: Py_MAX (x, y) Return the maximum value between ‘x’ and ‘y’. New in version 3.3. -- C Macro: Py_STRINGIFY (x) Convert ‘x’ to a C string. E.g. ‘Py_STRINGIFY(123)’ returns ‘"123"’. New in version 3.4. -- C Macro: Py_MEMBER_SIZE (type, member) Return the size of a structure (‘type’) ‘member’ in bytes. New in version 3.6. -- C Macro: Py_CHARMASK (c) Argument must be a character or an integer in the range [-128, 127] or [0, 255]. This macro returns ‘c’ cast to an ‘unsigned char’. -- C Macro: Py_GETENV (s) Like ‘getenv(s)’, but returns ‘NULL’ if *note -E: fdc. was passed on the command line (i.e. if ‘Py_IgnoreEnvironmentFlag’ is set). -- C Macro: Py_UNUSED (arg) Use this for unused arguments in a function definition to silence compiler warnings. Example: ‘int func(int a, int Py_UNUSED(b)) { return a; }’. New in version 3.4. -- C Macro: Py_DEPRECATED (version) Use this for deprecated declarations. The macro must be placed before the symbol name. Example: Py_DEPRECATED(3.8) PyAPI_FUNC(int) Py_OldFunction(void); Changed in version 3.8: MSVC support was added. -- C Macro: PyDoc_STRVAR (name, str) Creates a variable with name ‘name’ that can be used in docstrings. If Python is built without docstrings, the value will be empty. Use *note PyDoc_STRVAR: 38ea. for docstrings to support building Python without docstrings, as specified in PEP 7(1). Example: PyDoc_STRVAR(pop_doc, "Remove and return the rightmost element."); static PyMethodDef deque_methods[] = { // ... {"pop", (PyCFunction)deque_pop, METH_NOARGS, pop_doc}, // ... } -- C Macro: PyDoc_STR (str) Creates a docstring for the given input string or an empty string if docstrings are disabled. Use *note PyDoc_STR: 38eb. in specifying docstrings to support building Python without docstrings, as specified in PEP 7(2). Example: static PyMethodDef pysqlite_row_methods[] = { {"keys", (PyCFunction)pysqlite_row_keys, METH_NOARGS, PyDoc_STR("Returns the keys of the row.")}, {NULL, NULL} }; ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0007 (2) https://www.python.org/dev/peps/pep-0007  File: python.info, Node: Objects Types and Reference Counts, Next: Exceptions<18>, Prev: Useful macros, Up: Introduction<13> 7.1.4 Objects, Types and Reference Counts ----------------------------------------- Most Python/C API functions have one or more arguments as well as a return value of type *note PyObject*: 4ba. This type is a pointer to an opaque data type representing an arbitrary Python object. Since all Python object types are treated the same way by the Python language in most situations (e.g., assignments, scope rules, and argument passing), it is only fitting that they should be represented by a single C type. Almost all Python objects live on the heap: you never declare an automatic or static variable of type *note PyObject: 4ba, only pointer variables of type *note PyObject*: 4ba. can be declared. The sole exception are the type objects; since these must never be deallocated, they are typically static *note PyTypeObject: 2d6. objects. All Python objects (even Python integers) have a `type' and a `reference count'. An object’s type determines what kind of object it is (e.g., an integer, a list, or a user-defined function; there are many more as explained in *note The standard type hierarchy: 10c0.). For each of the well-known types there is a macro to check whether an object is of that type; for instance, ‘PyList_Check(a)’ is true if (and only if) the object pointed to by `a' is a Python list. * Menu: * Reference Counts: Reference Counts<2>. * Types::  File: python.info, Node: Reference Counts<2>, Next: Types, Up: Objects Types and Reference Counts 7.1.4.1 Reference Counts ........................ The reference count is important because today’s computers have a finite (and often severely limited) memory size; it counts how many different places there are that have a reference to an object. Such a place could be another object, or a global (or static) C variable, or a local variable in some C function. When an object’s reference count becomes zero, the object is deallocated. If it contains references to other objects, their reference count is decremented. Those other objects may be deallocated in turn, if this decrement makes their reference count become zero, and so on. (There’s an obvious problem with objects that reference each other here; for now, the solution is “don’t do that.”) Reference counts are always manipulated explicitly. The normal way is to use the macro *note Py_INCREF(): 265. to increment an object’s reference count by one, and *note Py_DECREF(): 266. to decrement it by one. The *note Py_DECREF(): 266. macro is considerably more complex than the incref one, since it must check whether the reference count becomes zero and then cause the object’s deallocator to be called. The deallocator is a function pointer contained in the object’s type structure. The type-specific deallocator takes care of decrementing the reference counts for other objects contained in the object if this is a compound object type, such as a list, as well as performing any additional finalization that’s needed. There’s no chance that the reference count can overflow; at least as many bits are used to hold the reference count as there are distinct memory locations in virtual memory (assuming ‘sizeof(Py_ssize_t) >= sizeof(void*)’). Thus, the reference count increment is a simple operation. It is not necessary to increment an object’s reference count for every local variable that contains a pointer to an object. In theory, the object’s reference count goes up by one when the variable is made to point to it and it goes down by one when the variable goes out of scope. However, these two cancel each other out, so at the end the reference count hasn’t changed. The only real reason to use the reference count is to prevent the object from being deallocated as long as our variable is pointing to it. If we know that there is at least one other reference to the object that lives at least as long as our variable, there is no need to increment the reference count temporarily. An important situation where this arises is in objects that are passed as arguments to C functions in an extension module that are called from Python; the call mechanism guarantees to hold a reference to every argument for the duration of the call. However, a common pitfall is to extract an object from a list and hold on to it for a while without incrementing its reference count. Some other operation might conceivably remove the object from the list, decrementing its reference count and possibly deallocating it. The real danger is that innocent-looking operations may invoke arbitrary Python code which could do this; there is a code path which allows control to flow back to the user from a *note Py_DECREF(): 266, so almost any operation is potentially dangerous. A safe approach is to always use the generic operations (functions whose name begins with ‘PyObject_’, ‘PyNumber_’, ‘PySequence_’ or ‘PyMapping_’). These operations always increment the reference count of the object they return. This leaves the caller with the responsibility to call *note Py_DECREF(): 266. when they are done with the result; this soon becomes second nature. * Menu: * Reference Count Details::  File: python.info, Node: Reference Count Details, Up: Reference Counts<2> 7.1.4.2 Reference Count Details ............................... The reference count behavior of functions in the Python/C API is best explained in terms of `ownership of references'. Ownership pertains to references, never to objects (objects are not owned: they are always shared). “Owning a reference” means being responsible for calling Py_DECREF on it when the reference is no longer needed. Ownership can also be transferred, meaning that the code that receives ownership of the reference then becomes responsible for eventually decref’ing it by calling *note Py_DECREF(): 266. or *note Py_XDECREF(): 268. when it’s no longer needed—or passing on this responsibility (usually to its caller). When a function passes ownership of a reference on to its caller, the caller is said to receive a `new' reference. When no ownership is transferred, the caller is said to `borrow' the reference. Nothing needs to be done for a borrowed reference. Conversely, when a calling function passes in a reference to an object, there are two possibilities: the function `steals' a reference to the object, or it does not. `Stealing a reference' means that when you pass a reference to a function, that function assumes that it now owns that reference, and you are not responsible for it any longer. Few functions steal references; the two notable exceptions are *note PyList_SetItem(): 3862. and *note PyTuple_SetItem(): 3861, which steal a reference to the item (but not to the tuple or list into which the item is put!). These functions were designed to steal a reference because of a common idiom for populating a tuple or list with newly created objects; for example, the code to create the tuple ‘(1, 2, "three")’ could look like this (forgetting about error handling for the moment; a better way to code this is shown below): PyObject *t; t = PyTuple_New(3); PyTuple_SetItem(t, 0, PyLong_FromLong(1L)); PyTuple_SetItem(t, 1, PyLong_FromLong(2L)); PyTuple_SetItem(t, 2, PyUnicode_FromString("three")); Here, *note PyLong_FromLong(): 3841. returns a new reference which is immediately stolen by *note PyTuple_SetItem(): 3861. When you want to keep using an object although the reference to it will be stolen, use *note Py_INCREF(): 265. to grab another reference before calling the reference-stealing function. Incidentally, *note PyTuple_SetItem(): 3861. is the `only' way to set tuple items; *note PySequence_SetItem(): 38f2. and *note PyObject_SetItem(): 38f3. refuse to do this since tuples are an immutable data type. You should only use *note PyTuple_SetItem(): 3861. for tuples that you are creating yourself. Equivalent code for populating a list can be written using *note PyList_New(): 38f4. and *note PyList_SetItem(): 3862. However, in practice, you will rarely use these ways of creating and populating a tuple or list. There’s a generic function, *note Py_BuildValue(): 2ce, that can create most common objects from C values, directed by a `format string'. For example, the above two blocks of code could be replaced by the following (which also takes care of the error checking): PyObject *tuple, *list; tuple = Py_BuildValue("(iis)", 1, 2, "three"); list = Py_BuildValue("[iis]", 1, 2, "three"); It is much more common to use *note PyObject_SetItem(): 38f3. and friends with items whose references you are only borrowing, like arguments that were passed in to the function you are writing. In that case, their behaviour regarding reference counts is much saner, since you don’t have to increment a reference count so you can give a reference away (“have it be stolen”). For example, this function sets all items of a list (actually, any mutable sequence) to a given item: int set_all(PyObject *target, PyObject *item) { Py_ssize_t i, n; n = PyObject_Length(target); if (n < 0) return -1; for (i = 0; i < n; i++) { PyObject *index = PyLong_FromSsize_t(i); if (!index) return -1; if (PyObject_SetItem(target, index, item) < 0) { Py_DECREF(index); return -1; } Py_DECREF(index); } return 0; } The situation is slightly different for function return values. While passing a reference to most functions does not change your ownership responsibilities for that reference, many functions that return a reference to an object give you ownership of the reference. The reason is simple: in many cases, the returned object is created on the fly, and the reference you get is the only reference to the object. Therefore, the generic functions that return object references, like *note PyObject_GetItem(): 38f5. and *note PySequence_GetItem(): 38f6, always return a new reference (the caller becomes the owner of the reference). It is important to realize that whether you own a reference returned by a function depends on which function you call only — `the plumage' (the type of the object passed as an argument to the function) `doesn’t enter into it!' Thus, if you extract an item from a list using *note PyList_GetItem(): 385d, you don’t own the reference — but if you obtain the same item from the same list using *note PySequence_GetItem(): 38f6. (which happens to take exactly the same arguments), you do own a reference to the returned object. Here is an example of how you could write a function that computes the sum of the items in a list of integers; once using *note PyList_GetItem(): 385d, and once using *note PySequence_GetItem(): 38f6. long sum_list(PyObject *list) { Py_ssize_t i, n; long total = 0, value; PyObject *item; n = PyList_Size(list); if (n < 0) return -1; /* Not a list */ for (i = 0; i < n; i++) { item = PyList_GetItem(list, i); /* Can't fail */ if (!PyLong_Check(item)) continue; /* Skip non-integers */ value = PyLong_AsLong(item); if (value == -1 && PyErr_Occurred()) /* Integer too big to fit in a C long, bail out */ return -1; total += value; } return total; } long sum_sequence(PyObject *sequence) { Py_ssize_t i, n; long total = 0, value; PyObject *item; n = PySequence_Length(sequence); if (n < 0) return -1; /* Has no length */ for (i = 0; i < n; i++) { item = PySequence_GetItem(sequence, i); if (item == NULL) return -1; /* Not a sequence, or other failure */ if (PyLong_Check(item)) { value = PyLong_AsLong(item); Py_DECREF(item); if (value == -1 && PyErr_Occurred()) /* Integer too big to fit in a C long, bail out */ return -1; total += value; } else { Py_DECREF(item); /* Discard reference ownership */ } } return total; }  File: python.info, Node: Types, Prev: Reference Counts<2>, Up: Objects Types and Reference Counts 7.1.4.3 Types ............. There are few other data types that play a significant role in the Python/C API; most are simple C types such as ‘int’, ‘long’, ‘double’ and ‘char*’. A few structure types are used to describe static tables used to list the functions exported by a module or the data attributes of a new object type, and another is used to describe the value of a complex number. These will be discussed together with the functions that use them.  File: python.info, Node: Exceptions<18>, Next: Embedding Python<2>, Prev: Objects Types and Reference Counts, Up: Introduction<13> 7.1.5 Exceptions ---------------- The Python programmer only needs to deal with exceptions if specific error handling is required; unhandled exceptions are automatically propagated to the caller, then to the caller’s caller, and so on, until they reach the top-level interpreter, where they are reported to the user accompanied by a stack traceback. For C programmers, however, error checking always has to be explicit. All functions in the Python/C API can raise exceptions, unless an explicit claim is made otherwise in a function’s documentation. In general, when a function encounters an error, it sets an exception, discards any object references that it owns, and returns an error indicator. If not documented otherwise, this indicator is either ‘NULL’ or ‘-1’, depending on the function’s return type. A few functions return a Boolean true/false result, with false indicating an error. Very few functions return no explicit error indicator or have an ambiguous return value, and require explicit testing for errors with *note PyErr_Occurred(): 383f. These exceptions are always explicitly documented. Exception state is maintained in per-thread storage (this is equivalent to using global storage in an unthreaded application). A thread can be in one of two states: an exception has occurred, or not. The function *note PyErr_Occurred(): 383f. can be used to check for this: it returns a borrowed reference to the exception type object when an exception has occurred, and ‘NULL’ otherwise. There are a number of functions to set the exception state: *note PyErr_SetString(): 383c. is the most common (though not the most general) function to set the exception state, and *note PyErr_Clear(): 96b. clears the exception state. The full exception state consists of three objects (all of which can be ‘NULL’): the exception type, the corresponding exception value, and the traceback. These have the same meanings as the Python result of ‘sys.exc_info()’; however, they are not the same: the Python objects represent the last exception being handled by a Python *note try: d72. … *note except: b3e. statement, while the C level exception state only exists while an exception is being passed on between C functions until it reaches the Python bytecode interpreter’s main loop, which takes care of transferring it to ‘sys.exc_info()’ and friends. Note that starting with Python 1.5, the preferred, thread-safe way to access the exception state from Python code is to call the function *note sys.exc_info(): c5f, which returns the per-thread exception state for Python code. Also, the semantics of both ways to access the exception state have changed so that a function which catches an exception will save and restore its thread’s exception state so as to preserve the exception state of its caller. This prevents common bugs in exception handling code caused by an innocent-looking function overwriting the exception being handled; it also reduces the often unwanted lifetime extension for objects that are referenced by the stack frames in the traceback. As a general principle, a function that calls another function to perform some task should check whether the called function raised an exception, and if so, pass the exception state on to its caller. It should discard any object references that it owns, and return an error indicator, but it should `not' set another exception — that would overwrite the exception that was just raised, and lose important information about the exact cause of the error. A simple example of detecting exceptions and passing them on is shown in the ‘sum_sequence()’ example above. It so happens that this example doesn’t need to clean up any owned references when it detects an error. The following example function shows some error cleanup. First, to remind you why you like Python, we show the equivalent Python code: def incr_item(dict, key): try: item = dict[key] except KeyError: item = 0 dict[key] = item + 1 Here is the corresponding C code, in all its glory: int incr_item(PyObject *dict, PyObject *key) { /* Objects all initialized to NULL for Py_XDECREF */ PyObject *item = NULL, *const_one = NULL, *incremented_item = NULL; int rv = -1; /* Return value initialized to -1 (failure) */ item = PyObject_GetItem(dict, key); if (item == NULL) { /* Handle KeyError only: */ if (!PyErr_ExceptionMatches(PyExc_KeyError)) goto error; /* Clear the error and use zero: */ PyErr_Clear(); item = PyLong_FromLong(0L); if (item == NULL) goto error; } const_one = PyLong_FromLong(1L); if (const_one == NULL) goto error; incremented_item = PyNumber_Add(item, const_one); if (incremented_item == NULL) goto error; if (PyObject_SetItem(dict, key, incremented_item) < 0) goto error; rv = 0; /* Success */ /* Continue with cleanup code */ error: /* Cleanup code, shared by success and failure path */ /* Use Py_XDECREF() to ignore NULL references */ Py_XDECREF(item); Py_XDECREF(const_one); Py_XDECREF(incremented_item); return rv; /* -1 for error, 0 for success */ } This example represents an endorsed use of the ‘goto’ statement in C! It illustrates the use of *note PyErr_ExceptionMatches(): 38fb. and *note PyErr_Clear(): 96b. to handle specific exceptions, and the use of *note Py_XDECREF(): 268. to dispose of owned references that may be ‘NULL’ (note the ‘'X'’ in the name; *note Py_DECREF(): 266. would crash when confronted with a ‘NULL’ reference). It is important that the variables used to hold owned references are initialized to ‘NULL’ for this to work; likewise, the proposed return value is initialized to ‘-1’ (failure) and only set to success after the final call made is successful.  File: python.info, Node: Embedding Python<2>, Next: Debugging Builds, Prev: Exceptions<18>, Up: Introduction<13> 7.1.6 Embedding Python ---------------------- The one important task that only embedders (as opposed to extension writers) of the Python interpreter have to worry about is the initialization, and possibly the finalization, of the Python interpreter. Most functionality of the interpreter can only be used after the interpreter has been initialized. The basic initialization function is *note Py_Initialize(): 439. This initializes the table of loaded modules, and creates the fundamental modules *note builtins: 13, *note __main__: 1, and *note sys: fd. It also initializes the module search path (‘sys.path’). *note Py_Initialize(): 439. does not set the “script argument list” (‘sys.argv’). If this variable is needed by Python code that will be executed later, it must be set explicitly with a call to ‘PySys_SetArgvEx(argc, argv, updatepath)’ after the call to *note Py_Initialize(): 439. On most systems (in particular, on Unix and Windows, although the details are slightly different), *note Py_Initialize(): 439. calculates the module search path based upon its best guess for the location of the standard Python interpreter executable, assuming that the Python library is found in a fixed location relative to the Python interpreter executable. In particular, it looks for a directory named ‘lib/python`X.Y'’ relative to the parent directory where the executable named ‘python’ is found on the shell command search path (the environment variable ‘PATH’). For instance, if the Python executable is found in ‘/usr/local/bin/python’, it will assume that the libraries are in ‘/usr/local/lib/python`X.Y'’. (In fact, this particular path is also the “fallback” location, used when no executable file named ‘python’ is found along ‘PATH’.) The user can override this behavior by setting the environment variable *note PYTHONHOME: 4d6, or insert additional directories in front of the standard path by setting *note PYTHONPATH: 953. The embedding application can steer the search by calling ‘Py_SetProgramName(file)’ `before' calling *note Py_Initialize(): 439. Note that *note PYTHONHOME: 4d6. still overrides this and *note PYTHONPATH: 953. is still inserted in front of the standard path. An application that requires total control has to provide its own implementation of *note Py_GetPath(): 38fe, *note Py_GetPrefix(): 38ff, *note Py_GetExecPrefix(): 3900, and *note Py_GetProgramFullPath(): 275. (all defined in ‘Modules/getpath.c’). Sometimes, it is desirable to “uninitialize” Python. For instance, the application may want to start over (make another call to *note Py_Initialize(): 439.) or the application is simply done with its use of Python and wants to free memory allocated by Python. This can be accomplished by calling *note Py_FinalizeEx(): 5c9. The function *note Py_IsInitialized(): 3901. returns true if Python is currently in the initialized state. More information about these functions is given in a later chapter. Notice that *note Py_FinalizeEx(): 5c9. does `not' free all memory allocated by the Python interpreter, e.g. memory allocated by extension modules currently cannot be released.  File: python.info, Node: Debugging Builds, Prev: Embedding Python<2>, Up: Introduction<13> 7.1.7 Debugging Builds ---------------------- Python can be built with several macros to enable extra checks of the interpreter and extension modules. These checks tend to add a large amount of overhead to the runtime so they are not enabled by default. A full list of the various types of debugging builds is in the file ‘Misc/SpecialBuilds.txt’ in the Python source distribution. Builds are available that support tracing of reference counts, debugging the memory allocator, or low-level profiling of the main interpreter loop. Only the most frequently-used builds will be described in the remainder of this section. Compiling the interpreter with the ‘Py_DEBUG’ macro defined produces what is generally meant by “a debug build” of Python. ‘Py_DEBUG’ is enabled in the Unix build by adding ‘--with-pydebug’ to the ‘./configure’ command. It is also implied by the presence of the not-Python-specific ‘_DEBUG’ macro. When ‘Py_DEBUG’ is enabled in the Unix build, compiler optimization is disabled. In addition to the reference count debugging described below, the following extra checks are performed: * Extra checks are added to the object allocator. * Extra checks are added to the parser and compiler. * Downcasts from wide types to narrow types are checked for loss of information. * A number of assertions are added to the dictionary and set implementations. In addition, the set object acquires a ‘test_c_api()’ method. * Sanity checks of the input arguments are added to frame creation. * The storage for ints is initialized with a known invalid pattern to catch reference to uninitialized digits. * Low-level tracing and extra exception checking are added to the runtime virtual machine. * Extra checks are added to the memory arena implementation. * Extra debugging is added to the thread module. There may be additional checks not mentioned here. Defining ‘Py_TRACE_REFS’ enables reference tracing. When defined, a circular doubly linked list of active objects is maintained by adding two extra fields to every *note PyObject: 4ba. Total allocations are tracked as well. Upon exit, all existing references are printed. (In interactive mode this happens after every statement run by the interpreter.) Implied by ‘Py_DEBUG’. Please refer to ‘Misc/SpecialBuilds.txt’ in the Python source distribution for more detailed information.  File: python.info, Node: Stable Application Binary Interface, Next: The Very High Level Layer, Prev: Introduction<13>, Up: Python/C API Reference Manual 7.2 Stable Application Binary Interface ======================================= Traditionally, the C API of Python will change with every release. Most changes will be source-compatible, typically by only adding API, rather than changing existing API or removing API (although some interfaces do get removed after being deprecated first). Unfortunately, the API compatibility does not extend to binary compatibility (the ABI). The reason is primarily the evolution of struct definitions, where addition of a new field, or changing the type of a field, might not break the API, but can break the ABI. As a consequence, extension modules need to be recompiled for every Python release (although an exception is possible on Unix when none of the affected interfaces are used). In addition, on Windows, extension modules link with a specific pythonXY.dll and need to be recompiled to link with a newer one. Since Python 3.2, a subset of the API has been declared to guarantee a stable ABI. Extension modules wishing to use this API (called “limited API”) need to define ‘Py_LIMITED_API’. A number of interpreter details then become hidden from the extension module; in return, a module is built that works on any 3.x version (x>=2) without recompilation. In some cases, the stable ABI needs to be extended with new functions. Extension modules wishing to use these new APIs need to set ‘Py_LIMITED_API’ to the ‘PY_VERSION_HEX’ value (see *note API and ABI Versioning: 335e.) of the minimum Python version they want to support (e.g. ‘0x03030000’ for Python 3.3). Such modules will work on all subsequent Python releases, but fail to load (because of missing symbols) on the older releases. As of Python 3.2, the set of functions available to the limited API is documented in PEP 384(1). In the C API documentation, API elements that are not part of the limited API are marked as “Not part of the limited API.” ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0384  File: python.info, Node: The Very High Level Layer, Next: Reference Counting, Prev: Stable Application Binary Interface, Up: Python/C API Reference Manual 7.3 The Very High Level Layer ============================= The functions in this chapter will let you execute Python source code given in a file or a buffer, but they will not let you interact in a more detailed way with the interpreter. Several of these functions accept a start symbol from the grammar as a parameter. The available start symbols are ‘Py_eval_input’, ‘Py_file_input’, and ‘Py_single_input’. These are described following the functions which accept them as parameters. Note also that several of these functions take ‘FILE*’ parameters. One particular issue which needs to be handled carefully is that the ‘FILE’ structure for different C libraries can be different and incompatible. Under Windows (at least), it is possible for dynamically linked extensions to actually use different libraries, so care should be taken that ‘FILE*’ parameters are only passed to these functions if it is certain that they were created by the same library that the Python runtime is using. -- C Function: int Py_Main (int argc, wchar_t **argv) The main program for the standard interpreter. This is made available for programs which embed Python. The `argc' and `argv' parameters should be prepared exactly as those which are passed to a C program’s ‘main()’ function (converted to wchar_t according to the user’s locale). It is important to note that the argument list may be modified (but the contents of the strings pointed to by the argument list are not). The return value will be ‘0’ if the interpreter exits normally (i.e., without an exception), ‘1’ if the interpreter exits due to an exception, or ‘2’ if the parameter list does not represent a valid Python command line. Note that if an otherwise unhandled *note SystemExit: 5fc. is raised, this function will not return ‘1’, but exit the process, as long as ‘Py_InspectFlag’ is not set. -- C Function: int Py_BytesMain (int argc, char **argv) Similar to *note Py_Main(): 4b7. but `argv' is an array of bytes strings. New in version 3.8. -- C Function: int PyRun_AnyFile (FILE *fp, const char *filename) This is a simplified interface to *note PyRun_AnyFileExFlags(): 390b. below, leaving `closeit' set to ‘0’ and `flags' set to ‘NULL’. -- C Function: int PyRun_AnyFileFlags (FILE *fp, const char *filename, PyCompilerFlags *flags) This is a simplified interface to *note PyRun_AnyFileExFlags(): 390b. below, leaving the `closeit' argument set to ‘0’. -- C Function: int PyRun_AnyFileEx (FILE *fp, const char *filename, int closeit) This is a simplified interface to *note PyRun_AnyFileExFlags(): 390b. below, leaving the `flags' argument set to ‘NULL’. -- C Function: int PyRun_AnyFileExFlags (FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags) If `fp' refers to a file associated with an interactive device (console or terminal input or Unix pseudo-terminal), return the value of *note PyRun_InteractiveLoop(): 390e, otherwise return the result of *note PyRun_SimpleFile(): 38c9. `filename' is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). If `filename' is ‘NULL’, this function uses ‘"???"’ as the filename. -- C Function: int PyRun_SimpleString (const char *command) This is a simplified interface to *note PyRun_SimpleStringFlags(): 390f. below, leaving the *note PyCompilerFlags: 2cc.* argument set to ‘NULL’. -- C Function: int PyRun_SimpleStringFlags (const char *command, PyCompilerFlags *flags) Executes the Python source code from `command' in the *note __main__: 1. module according to the `flags' argument. If *note __main__: 1. does not already exist, it is created. Returns ‘0’ on success or ‘-1’ if an exception was raised. If there was an error, there is no way to get the exception information. For the meaning of `flags', see below. Note that if an otherwise unhandled *note SystemExit: 5fc. is raised, this function will not return ‘-1’, but exit the process, as long as ‘Py_InspectFlag’ is not set. -- C Function: int PyRun_SimpleFile (FILE *fp, const char *filename) This is a simplified interface to *note PyRun_SimpleFileExFlags(): 3910. below, leaving `closeit' set to ‘0’ and `flags' set to ‘NULL’. -- C Function: int PyRun_SimpleFileEx (FILE *fp, const char *filename, int closeit) This is a simplified interface to *note PyRun_SimpleFileExFlags(): 3910. below, leaving `flags' set to ‘NULL’. -- C Function: int PyRun_SimpleFileExFlags (FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags) Similar to *note PyRun_SimpleStringFlags(): 390f, but the Python source code is read from `fp' instead of an in-memory string. `filename' should be the name of the file, it is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). If `closeit' is true, the file is closed before PyRun_SimpleFileExFlags returns. Note: On Windows, `fp' should be opened as binary mode (e.g. ‘fopen(filename, "rb")’. Otherwise, Python may not handle script file with LF line ending correctly. -- C Function: int PyRun_InteractiveOne (FILE *fp, const char *filename) This is a simplified interface to *note PyRun_InteractiveOneFlags(): 3913. below, leaving `flags' set to ‘NULL’. -- C Function: int PyRun_InteractiveOneFlags (FILE *fp, const char *filename, PyCompilerFlags *flags) Read and execute a single statement from a file associated with an interactive device according to the `flags' argument. The user will be prompted using ‘sys.ps1’ and ‘sys.ps2’. `filename' is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). Returns ‘0’ when the input was executed successfully, ‘-1’ if there was an exception, or an error code from the ‘errcode.h’ include file distributed as part of Python if there was a parse error. (Note that ‘errcode.h’ is not included by ‘Python.h’, so must be included specifically if needed.) -- C Function: int PyRun_InteractiveLoop (FILE *fp, const char *filename) This is a simplified interface to *note PyRun_InteractiveLoopFlags(): 3914. below, leaving `flags' set to ‘NULL’. -- C Function: int PyRun_InteractiveLoopFlags (FILE *fp, const char *filename, PyCompilerFlags *flags) Read and execute statements from a file associated with an interactive device until EOF is reached. The user will be prompted using ‘sys.ps1’ and ‘sys.ps2’. `filename' is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). Returns ‘0’ at EOF or a negative number upon failure. -- C Variable: int (*PyOS_InputHook) (void) Can be set to point to a function with the prototype ‘int func(void)’. The function will be called when Python’s interpreter prompt is about to become idle and wait for user input from the terminal. The return value is ignored. Overriding this hook can be used to integrate the interpreter’s prompt with other event loops, as done in the ‘Modules/_tkinter.c’ in the Python source code. -- C Variable: char* (*PyOS_ReadlineFunctionPointer) (FILE *, FILE *, const char *) Can be set to point to a function with the prototype ‘char *func(FILE *stdin, FILE *stdout, char *prompt)’, overriding the default function used to read a single line of input at the interpreter’s prompt. The function is expected to output the string `prompt' if it’s not ‘NULL’, and then read a line of input from the provided standard input file, returning the resulting string. For example, The *note readline: de. module sets this hook to provide line-editing and tab-completion features. The result must be a string allocated by *note PyMem_RawMalloc(): 96d. or *note PyMem_RawRealloc(): 96e, or ‘NULL’ if an error occurred. Changed in version 3.4: The result must be allocated by *note PyMem_RawMalloc(): 96d. or *note PyMem_RawRealloc(): 96e, instead of being allocated by *note PyMem_Malloc(): 505. or *note PyMem_Realloc(): 96f. -- C Function: struct _node* PyParser_SimpleParseString (const char *str, int start) This is a simplified interface to *note PyParser_SimpleParseStringFlagsFilename(): 3917. below, leaving `filename' set to ‘NULL’ and `flags' set to ‘0’. -- C Function: struct _node* PyParser_SimpleParseStringFlags (const char *str, int start, int flags) This is a simplified interface to *note PyParser_SimpleParseStringFlagsFilename(): 3917. below, leaving `filename' set to ‘NULL’. -- C Function: struct _node* PyParser_SimpleParseStringFlagsFilename (const char *str, const char *filename, int start, int flags) Parse Python source code from `str' using the start token `start' according to the `flags' argument. The result can be used to create a code object which can be evaluated efficiently. This is useful if a code fragment must be evaluated many times. `filename' is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). -- C Function: struct _node* PyParser_SimpleParseFile (FILE *fp, const char *filename, int start) This is a simplified interface to *note PyParser_SimpleParseFileFlags(): 391a. below, leaving `flags' set to ‘0’. -- C Function: struct _node* PyParser_SimpleParseFileFlags (FILE *fp, const char *filename, int start, int flags) Similar to *note PyParser_SimpleParseStringFlagsFilename(): 3917, but the Python source code is read from `fp' instead of an in-memory string. -- C Function: PyObject* PyRun_String (const char *str, int start, PyObject *globals, PyObject *locals) `Return value: New reference.' This is a simplified interface to *note PyRun_StringFlags(): 391c. below, leaving `flags' set to ‘NULL’. -- C Function: PyObject* PyRun_StringFlags (const char *str, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags) `Return value: New reference.' Execute Python source code from `str' in the context specified by the objects `globals' and `locals' with the compiler flags specified by `flags'. `globals' must be a dictionary; `locals' can be any object that implements the mapping protocol. The parameter `start' specifies the start token that should be used to parse the source code. Returns the result of executing the code as a Python object, or ‘NULL’ if an exception was raised. -- C Function: PyObject* PyRun_File (FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals) `Return value: New reference.' This is a simplified interface to *note PyRun_FileExFlags(): 391e. below, leaving `closeit' set to ‘0’ and `flags' set to ‘NULL’. -- C Function: PyObject* PyRun_FileEx (FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit) `Return value: New reference.' This is a simplified interface to *note PyRun_FileExFlags(): 391e. below, leaving `flags' set to ‘NULL’. -- C Function: PyObject* PyRun_FileFlags (FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags) `Return value: New reference.' This is a simplified interface to *note PyRun_FileExFlags(): 391e. below, leaving `closeit' set to ‘0’. -- C Function: PyObject* PyRun_FileExFlags (FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit, PyCompilerFlags *flags) `Return value: New reference.' Similar to *note PyRun_StringFlags(): 391c, but the Python source code is read from `fp' instead of an in-memory string. `filename' should be the name of the file, it is decoded from the filesystem encoding (*note sys.getfilesystemencoding(): 4f6.). If `closeit' is true, the file is closed before *note PyRun_FileExFlags(): 391e. returns. -- C Function: PyObject* Py_CompileString (const char *str, const char *filename, int start) `Return value: New reference.' This is a simplified interface to *note Py_CompileStringFlags(): 3922. below, leaving `flags' set to ‘NULL’. -- C Function: PyObject* Py_CompileStringFlags (const char *str, const char *filename, int start, PyCompilerFlags *flags) `Return value: New reference.' This is a simplified interface to *note Py_CompileStringExFlags(): 3923. below, with `optimize' set to ‘-1’. -- C Function: PyObject* Py_CompileStringObject (const char *str, PyObject *filename, int start, PyCompilerFlags *flags, int optimize) `Return value: New reference.' Parse and compile the Python source code in `str', returning the resulting code object. The start token is given by `start'; this can be used to constrain the code which can be compiled and should be ‘Py_eval_input’, ‘Py_file_input’, or ‘Py_single_input’. The filename specified by `filename' is used to construct the code object and may appear in tracebacks or *note SyntaxError: 458. exception messages. This returns ‘NULL’ if the code cannot be parsed or compiled. The integer `optimize' specifies the optimization level of the compiler; a value of ‘-1’ selects the optimization level of the interpreter as given by *note -O: 68b. options. Explicit levels are ‘0’ (no optimization; ‘__debug__’ is true), ‘1’ (asserts are removed, ‘__debug__’ is false) or ‘2’ (docstrings are removed too). New in version 3.4. -- C Function: PyObject* Py_CompileStringExFlags (const char *str, const char *filename, int start, PyCompilerFlags *flags, int optimize) `Return value: New reference.' Like *note Py_CompileStringObject(): 3924, but `filename' is a byte string decoded from the filesystem encoding (*note os.fsdecode(): 4ee.). New in version 3.2. -- C Function: PyObject* PyEval_EvalCode (PyObject *co, PyObject *globals, PyObject *locals) `Return value: New reference.' This is a simplified interface to *note PyEval_EvalCodeEx(): 3926, with just the code object, and global and local variables. The other arguments are set to ‘NULL’. -- C Function: PyObject* PyEval_EvalCodeEx (PyObject *co, PyObject *globals, PyObject *locals, PyObject *const *args, int argcount, PyObject *const *kws, int kwcount, PyObject *const *defs, int defcount, PyObject *kwdefs, PyObject *closure) `Return value: New reference.' Evaluate a precompiled code object, given a particular environment for its evaluation. This environment consists of a dictionary of global variables, a mapping object of local variables, arrays of arguments, keywords and defaults, a dictionary of default values for *note keyword-only: 2ac. arguments and a closure tuple of cells. -- C Type: PyFrameObject The C structure of the objects used to describe frame objects. The fields of this type are subject to change at any time. -- C Function: PyObject* PyEval_EvalFrame (PyFrameObject *f) `Return value: New reference.' Evaluate an execution frame. This is a simplified interface to *note PyEval_EvalFrameEx(): 967, for backward compatibility. -- C Function: PyObject* PyEval_EvalFrameEx (PyFrameObject *f, int throwflag) `Return value: New reference.' This is the main, unvarnished function of Python interpretation. The code object associated with the execution frame `f' is executed, interpreting bytecode and executing calls as needed. The additional `throwflag' parameter can mostly be ignored - if true, then it causes an exception to immediately be thrown; this is used for the *note throw(): 1134. methods of generator objects. Changed in version 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception. -- C Function: int PyEval_MergeCompilerFlags (PyCompilerFlags *cf) This function changes the flags of the current evaluation frame, and returns true on success, false on failure. -- C Variable: int Py_eval_input The start symbol from the Python grammar for isolated expressions; for use with *note Py_CompileString(): 3921. -- C Variable: int Py_file_input The start symbol from the Python grammar for sequences of statements as read from a file or other source; for use with *note Py_CompileString(): 3921. This is the symbol to use when compiling arbitrarily long Python source code. -- C Variable: int Py_single_input The start symbol from the Python grammar for a single statement; for use with *note Py_CompileString(): 3921. This is the symbol used for the interactive interpreter loop. -- C Type: struct PyCompilerFlags This is the structure used to hold compiler flags. In cases where code is only being compiled, it is passed as ‘int flags’, and in cases where code is being executed, it is passed as ‘PyCompilerFlags *flags’. In this case, ‘from __future__ import’ can modify `flags'. Whenever ‘PyCompilerFlags *flags’ is ‘NULL’, ‘cf_flags’ is treated as equal to ‘0’, and any modification due to ‘from __future__ import’ is discarded. -- C Member: int cf_flags Compiler flags. -- C Member: int cf_feature_version `cf_feature_version' is the minor Python version. It should be initialized to ‘PY_MINOR_VERSION’. The field is ignored by default, it is used if and only if ‘PyCF_ONLY_AST’ flag is set in `cf_flags'. Changed in version 3.8: Added `cf_feature_version' field. -- C Variable: int CO_FUTURE_DIVISION This bit can be set in `flags' to cause division operator ‘/’ to be interpreted as “true division” according to PEP 238(1). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0238  File: python.info, Node: Reference Counting, Next: Exception Handling, Prev: The Very High Level Layer, Up: Python/C API Reference Manual 7.4 Reference Counting ====================== The macros in this section are used for managing reference counts of Python objects. -- C Function: void Py_INCREF (PyObject *o) Increment the reference count for object `o'. The object must not be ‘NULL’; if you aren’t sure that it isn’t ‘NULL’, use *note Py_XINCREF(): 267. -- C Function: void Py_XINCREF (PyObject *o) Increment the reference count for object `o'. The object may be ‘NULL’, in which case the macro has no effect. -- C Function: void Py_DECREF (PyObject *o) Decrement the reference count for object `o'. The object must not be ‘NULL’; if you aren’t sure that it isn’t ‘NULL’, use *note Py_XDECREF(): 268. If the reference count reaches zero, the object’s type’s deallocation function (which must not be ‘NULL’) is invoked. Warning: The deallocation function can cause arbitrary Python code to be invoked (e.g. when a class instance with a *note __del__(): 91f. method is deallocated). While exceptions in such code are not propagated, the executed code has free access to all Python global variables. This means that any object that is reachable from a global variable should be in a consistent state before *note Py_DECREF(): 266. is invoked. For example, code to delete an object from a list should copy a reference to the deleted object in a temporary variable, update the list data structure, and then call *note Py_DECREF(): 266. for the temporary variable. -- C Function: void Py_XDECREF (PyObject *o) Decrement the reference count for object `o'. The object may be ‘NULL’, in which case the macro has no effect; otherwise the effect is the same as for *note Py_DECREF(): 266, and the same warning applies. -- C Function: void Py_CLEAR (PyObject *o) Decrement the reference count for object `o'. The object may be ‘NULL’, in which case the macro has no effect; otherwise the effect is the same as for *note Py_DECREF(): 266, except that the argument is also set to ‘NULL’. The warning for *note Py_DECREF(): 266. does not apply with respect to the object passed because the macro carefully uses a temporary variable and sets the argument to ‘NULL’ before decrementing its reference count. It is a good idea to use this macro whenever decrementing the reference count of an object that might be traversed during garbage collection. The following functions are for runtime dynamic embedding of Python: ‘Py_IncRef(PyObject *o)’, ‘Py_DecRef(PyObject *o)’. They are simply exported function versions of *note Py_XINCREF(): 267. and *note Py_XDECREF(): 268, respectively. The following functions or macros are only for use within the interpreter core: ‘_Py_Dealloc()’, ‘_Py_ForgetReference()’, ‘_Py_NewReference()’, as well as the global variable ‘_Py_RefTotal’.  File: python.info, Node: Exception Handling, Next: Utilities<2>, Prev: Reference Counting, Up: Python/C API Reference Manual 7.5 Exception Handling ====================== The functions described in this chapter will let you handle and raise Python exceptions. It is important to understand some of the basics of Python exception handling. It works somewhat like the POSIX ‘errno’ variable: there is a global indicator (per thread) of the last error that occurred. Most C API functions don’t clear this on success, but will set it to indicate the cause of the error on failure. Most C API functions also return an error indicator, usually ‘NULL’ if they are supposed to return a pointer, or ‘-1’ if they return an integer (exception: the ‘PyArg_*()’ functions return ‘1’ for success and ‘0’ for failure). Concretely, the error indicator consists of three object pointers: the exception’s type, the exception’s value, and the traceback object. Any of those pointers can be ‘NULL’ if non-set (although some combinations are forbidden, for example you can’t have a non-‘NULL’ traceback if the exception type is ‘NULL’). When a function must fail because some function it called failed, it generally doesn’t set the error indicator; the function it called already set it. It is responsible for either handling the error and clearing the exception or returning after cleaning up any resources it holds (such as object references or memory allocations); it should `not' continue normally if it is not prepared to handle the error. If returning due to an error, it is important to indicate to the caller that an error has been set. If the error is not handled or carefully propagated, additional calls into the Python/C API may not behave as intended and may fail in mysterious ways. Note: The error indicator is `not' the result of *note sys.exc_info(): c5f. The former corresponds to an exception that is not yet caught (and is therefore still propagating), while the latter returns an exception after it is caught (and has therefore stopped propagating). * Menu: * Printing and clearing:: * Raising exceptions:: * Issuing warnings:: * Querying the error indicator:: * Signal Handling: Signal Handling<2>. * Exception Classes:: * Exception Objects:: * Unicode Exception Objects:: * Recursion Control:: * Standard Exceptions:: * Standard Warning Categories::  File: python.info, Node: Printing and clearing, Next: Raising exceptions, Up: Exception Handling 7.5.1 Printing and clearing --------------------------- -- C Function: void PyErr_Clear () Clear the error indicator. If the error indicator is not set, there is no effect. -- C Function: void PyErr_PrintEx (int set_sys_last_vars) Print a standard traceback to ‘sys.stderr’ and clear the error indicator. `Unless' the error is a ‘SystemExit’, in that case no traceback is printed and the Python process will exit with the error code specified by the ‘SystemExit’ instance. Call this function `only' when the error indicator is set. Otherwise it will cause a fatal error! If `set_sys_last_vars' is nonzero, the variables *note sys.last_type: c5a, *note sys.last_value: 335f. and *note sys.last_traceback: 325a. will be set to the type, value and traceback of the printed exception, respectively. -- C Function: void PyErr_Print () Alias for ‘PyErr_PrintEx(1)’. -- C Function: void PyErr_WriteUnraisable (PyObject *obj) Call *note sys.unraisablehook(): 22d. using the current exception and `obj' argument. This utility function prints a warning message to ‘sys.stderr’ when an exception has been set but it is impossible for the interpreter to actually raise the exception. It is used, for example, when an exception occurs in an *note __del__(): 91f. method. The function is called with a single argument `obj' that identifies the context in which the unraisable exception occurred. If possible, the repr of `obj' will be printed in the warning message. An exception must be set when calling this function.  File: python.info, Node: Raising exceptions, Next: Issuing warnings, Prev: Printing and clearing, Up: Exception Handling 7.5.2 Raising exceptions ------------------------ These functions help you set the current thread’s error indicator. For convenience, some of these functions will always return a ‘NULL’ pointer for use in a ‘return’ statement. -- C Function: void PyErr_SetString (PyObject *type, const char *message) This is the most common way to set the error indicator. The first argument specifies the exception type; it is normally one of the standard exceptions, e.g. ‘PyExc_RuntimeError’. You need not increment its reference count. The second argument is an error message; it is decoded from ‘'utf-8’’. -- C Function: void PyErr_SetObject (PyObject *type, PyObject *value) This function is similar to *note PyErr_SetString(): 383c. but lets you specify an arbitrary Python object for the “value” of the exception. -- C Function: PyObject* PyErr_Format (PyObject *exception, const char *format, ...) `Return value: Always NULL.' This function sets the error indicator and returns ‘NULL’. `exception' should be a Python exception class. The `format' and subsequent parameters help format the error message; they have the same meaning and values as in *note PyUnicode_FromFormat(): 7cb. `format' is an ASCII-encoded string. -- C Function: PyObject* PyErr_FormatV (PyObject *exception, const char *format, va_list vargs) `Return value: Always NULL.' Same as *note PyErr_Format(): 7aa, but taking a ‘va_list’ argument rather than a variable number of arguments. New in version 3.5. -- C Function: void PyErr_SetNone (PyObject *type) This is a shorthand for ‘PyErr_SetObject(type, Py_None)’. -- C Function: int PyErr_BadArgument () This is a shorthand for ‘PyErr_SetString(PyExc_TypeError, message)’, where `message' indicates that a built-in operation was invoked with an illegal argument. It is mostly for internal use. -- C Function: PyObject* PyErr_NoMemory () `Return value: Always NULL.' This is a shorthand for ‘PyErr_SetNone(PyExc_MemoryError)’; it returns ‘NULL’ so an object allocation function can write ‘return PyErr_NoMemory();’ when it runs out of memory. -- C Function: PyObject* PyErr_SetFromErrno (PyObject *type) `Return value: Always NULL.' This is a convenience function to raise an exception when a C library function has returned an error and set the C variable ‘errno’. It constructs a tuple object whose first item is the integer ‘errno’ value and whose second item is the corresponding error message (gotten from ‘strerror()’), and then calls ‘PyErr_SetObject(type, object)’. On Unix, when the ‘errno’ value is ‘EINTR’, indicating an interrupted system call, this calls *note PyErr_CheckSignals(): 393b, and if that set the error indicator, leaves it set to that. The function always returns ‘NULL’, so a wrapper function around a system call can write ‘return PyErr_SetFromErrno(type);’ when the system call returns an error. -- C Function: PyObject* PyErr_SetFromErrnoWithFilenameObject (PyObject *type, PyObject *filenameObject) `Return value: Always NULL.' Similar to *note PyErr_SetFromErrno(): 383d, with the additional behavior that if `filenameObject' is not ‘NULL’, it is passed to the constructor of `type' as a third parameter. In the case of *note OSError: 1d3. exception, this is used to define the ‘filename’ attribute of the exception instance. -- C Function: PyObject* PyErr_SetFromErrnoWithFilenameObjects (PyObject *type, PyObject *filenameObject, PyObject *filenameObject2) `Return value: Always NULL.' Similar to *note PyErr_SetFromErrnoWithFilenameObject(): 393c, but takes a second filename object, for raising errors when a function that takes two filenames fails. New in version 3.4. -- C Function: PyObject* PyErr_SetFromErrnoWithFilename (PyObject *type, const char *filename) `Return value: Always NULL.' Similar to *note PyErr_SetFromErrnoWithFilenameObject(): 393c, but the filename is given as a C string. `filename' is decoded from the filesystem encoding (*note os.fsdecode(): 4ee.). -- C Function: PyObject* PyErr_SetFromWindowsErr (int ierr) `Return value: Always NULL.' This is a convenience function to raise *note WindowsError: 994. If called with `ierr' of ‘0’, the error code returned by a call to ‘GetLastError()’ is used instead. It calls the Win32 function ‘FormatMessage()’ to retrieve the Windows description of error code given by `ierr' or ‘GetLastError()’, then it constructs a tuple object whose first item is the `ierr' value and whose second item is the corresponding error message (gotten from ‘FormatMessage()’), and then calls ‘PyErr_SetObject(PyExc_WindowsError, object)’. This function always returns ‘NULL’. *note Availability: ffb.: Windows. -- C Function: PyObject* PyErr_SetExcFromWindowsErr (PyObject *type, int ierr) `Return value: Always NULL.' Similar to *note PyErr_SetFromWindowsErr(): 393f, with an additional parameter specifying the exception type to be raised. *note Availability: ffb.: Windows. -- C Function: PyObject* PyErr_SetFromWindowsErrWithFilename (int ierr, const char *filename) `Return value: Always NULL.' Similar to ‘PyErr_SetFromWindowsErrWithFilenameObject()’, but the filename is given as a C string. `filename' is decoded from the filesystem encoding (*note os.fsdecode(): 4ee.). *note Availability: ffb.: Windows. -- C Function: PyObject* PyErr_SetExcFromWindowsErrWithFilenameObject (PyObject *type, int ierr, PyObject *filename) `Return value: Always NULL.' Similar to ‘PyErr_SetFromWindowsErrWithFilenameObject()’, with an additional parameter specifying the exception type to be raised. *note Availability: ffb.: Windows. -- C Function: PyObject* PyErr_SetExcFromWindowsErrWithFilenameObjects (PyObject *type, int ierr, PyObject *filename, PyObject *filename2) `Return value: Always NULL.' Similar to *note PyErr_SetExcFromWindowsErrWithFilenameObject(): 3942, but accepts a second filename object. *note Availability: ffb.: Windows. New in version 3.4. -- C Function: PyObject* PyErr_SetExcFromWindowsErrWithFilename (PyObject *type, int ierr, const char *filename) `Return value: Always NULL.' Similar to *note PyErr_SetFromWindowsErrWithFilename(): 3941, with an additional parameter specifying the exception type to be raised. *note Availability: ffb.: Windows. -- C Function: PyObject* PyErr_SetImportError (PyObject *msg, PyObject *name, PyObject *path) `Return value: Always NULL.' This is a convenience function to raise *note ImportError: 334. `msg' will be set as the exception’s message string. `name' and `path', both of which can be ‘NULL’, will be set as the *note ImportError: 334.’s respective ‘name’ and ‘path’ attributes. New in version 3.3. -- C Function: void PyErr_SyntaxLocationObject (PyObject *filename, int lineno, int col_offset) Set file, line, and offset information for the current exception. If the current exception is not a *note SyntaxError: 458, then it sets additional attributes, which make the exception printing subsystem think the exception is a *note SyntaxError: 458. New in version 3.4. -- C Function: void PyErr_SyntaxLocationEx (const char *filename, int lineno, int col_offset) Like *note PyErr_SyntaxLocationObject(): 3945, but `filename' is a byte string decoded from the filesystem encoding (*note os.fsdecode(): 4ee.). New in version 3.2. -- C Function: void PyErr_SyntaxLocation (const char *filename, int lineno) Like *note PyErr_SyntaxLocationEx(): 3946, but the col_offset parameter is omitted. -- C Function: void PyErr_BadInternalCall () This is a shorthand for ‘PyErr_SetString(PyExc_SystemError, message)’, where `message' indicates that an internal operation (e.g. a Python/C API function) was invoked with an illegal argument. It is mostly for internal use.  File: python.info, Node: Issuing warnings, Next: Querying the error indicator, Prev: Raising exceptions, Up: Exception Handling 7.5.3 Issuing warnings ---------------------- Use these functions to issue warnings from C code. They mirror similar functions exported by the Python *note warnings: 126. module. They normally print a warning message to `sys.stderr'; however, it is also possible that the user has specified that warnings are to be turned into errors, and in that case they will raise an exception. It is also possible that the functions raise an exception because of a problem with the warning machinery. The return value is ‘0’ if no exception is raised, or ‘-1’ if an exception is raised. (It is not possible to determine whether a warning message is actually printed, nor what the reason is for the exception; this is intentional.) If an exception is raised, the caller should do its normal exception handling (for example, *note Py_DECREF(): 266. owned references and return an error value). -- C Function: int PyErr_WarnEx (PyObject *category, const char *message, Py_ssize_t stack_level) Issue a warning message. The `category' argument is a warning category (see below) or ‘NULL’; the `message' argument is a UTF-8 encoded string. `stack_level' is a positive number giving a number of stack frames; the warning will be issued from the currently executing line of code in that stack frame. A `stack_level' of 1 is the function calling *note PyErr_WarnEx(): db1, 2 is the function above that, and so forth. Warning categories must be subclasses of ‘PyExc_Warning’; ‘PyExc_Warning’ is a subclass of ‘PyExc_Exception’; the default warning category is ‘PyExc_RuntimeWarning’. The standard Python warning categories are available as global variables whose names are enumerated at *note Standard Warning Categories: 394a. For information about warning control, see the documentation for the *note warnings: 126. module and the *note -W: 417. option in the command line documentation. There is no C API for warning control. -- C Function: PyObject* PyErr_SetImportErrorSubclass (PyObject *exception, PyObject *msg, PyObject *name, PyObject *path) `Return value: Always NULL.' Much like *note PyErr_SetImportError(): 5f8. but this function allows for specifying a subclass of *note ImportError: 334. to raise. New in version 3.6. -- C Function: int PyErr_WarnExplicitObject (PyObject *category, PyObject *message, PyObject *filename, int lineno, PyObject *module, PyObject *registry) Issue a warning message with explicit control over all warning attributes. This is a straightforward wrapper around the Python function *note warnings.warn_explicit(): 5b0, see there for more information. The `module' and `registry' arguments may be set to ‘NULL’ to get the default effect described there. New in version 3.4. -- C Function: int PyErr_WarnExplicit (PyObject *category, const char *message, const char *filename, int lineno, const char *module, PyObject *registry) Similar to *note PyErr_WarnExplicitObject(): 394b. except that `message' and `module' are UTF-8 encoded strings, and `filename' is decoded from the filesystem encoding (*note os.fsdecode(): 4ee.). -- C Function: int PyErr_WarnFormat (PyObject *category, Py_ssize_t stack_level, const char *format, ...) Function similar to *note PyErr_WarnEx(): db1, but use *note PyUnicode_FromFormat(): 7cb. to format the warning message. `format' is an ASCII-encoded string. New in version 3.2. -- C Function: int PyErr_ResourceWarning (PyObject *source, Py_ssize_t stack_level, const char *format, ...) Function similar to *note PyErr_WarnFormat(): 394d, but `category' is *note ResourceWarning: 4d0. and it passes `source' to ‘warnings.WarningMessage()’. New in version 3.6.  File: python.info, Node: Querying the error indicator, Next: Signal Handling<2>, Prev: Issuing warnings, Up: Exception Handling 7.5.4 Querying the error indicator ---------------------------------- -- C Function: PyObject* PyErr_Occurred () `Return value: Borrowed reference.' Test whether the error indicator is set. If set, return the exception `type' (the first argument to the last call to one of the ‘PyErr_Set*()’ functions or to *note PyErr_Restore(): 3897.). If not set, return ‘NULL’. You do not own a reference to the return value, so you do not need to *note Py_DECREF(): 266. it. Note: Do not compare the return value to a specific exception; use *note PyErr_ExceptionMatches(): 38fb. instead, shown below. (The comparison could easily fail since the exception may be an instance instead of a class, in the case of a class exception, or it may be a subclass of the expected exception.) -- C Function: int PyErr_ExceptionMatches (PyObject *exc) Equivalent to ‘PyErr_GivenExceptionMatches(PyErr_Occurred(), exc)’. This should only be called when an exception is actually set; a memory access violation will occur if no exception has been raised. -- C Function: int PyErr_GivenExceptionMatches (PyObject *given, PyObject *exc) Return true if the `given' exception matches the exception type in `exc'. If `exc' is a class object, this also returns true when `given' is an instance of a subclass. If `exc' is a tuple, all exception types in the tuple (and recursively in subtuples) are searched for a match. -- C Function: void PyErr_Fetch (PyObject **ptype, PyObject **pvalue, PyObject **ptraceback) Retrieve the error indicator into three variables whose addresses are passed. If the error indicator is not set, set all three variables to ‘NULL’. If it is set, it will be cleared and you own a reference to each object retrieved. The value and traceback object may be ‘NULL’ even when the type object is not. Note: This function is normally only used by code that needs to catch exceptions or by code that needs to save and restore the error indicator temporarily, e.g.: { PyObject *type, *value, *traceback; PyErr_Fetch(&type, &value, &traceback); /* ... code that might produce other errors ... */ PyErr_Restore(type, value, traceback); } -- C Function: void PyErr_Restore (PyObject *type, PyObject *value, PyObject *traceback) Set the error indicator from the three objects. If the error indicator is already set, it is cleared first. If the objects are ‘NULL’, the error indicator is cleared. Do not pass a ‘NULL’ type and non-‘NULL’ value or traceback. The exception type should be a class. Do not pass an invalid exception type or value. (Violating these rules will cause subtle problems later.) This call takes away a reference to each object: you must own a reference to each object before the call and after the call you no longer own these references. (If you don’t understand this, don’t use this function. I warned you.) Note: This function is normally only used by code that needs to save and restore the error indicator temporarily. Use *note PyErr_Fetch(): 96a. to save the current error indicator. -- C Function: void PyErr_NormalizeException (PyObject**exc, PyObject**val, PyObject**tb) Under certain circumstances, the values returned by *note PyErr_Fetch(): 96a. below can be “unnormalized”, meaning that ‘*exc’ is a class object but ‘*val’ is not an instance of the same class. This function can be used to instantiate the class in that case. If the values are already normalized, nothing happens. The delayed normalization is implemented to improve performance. Note: This function `does not' implicitly set the ‘__traceback__’ attribute on the exception value. If setting the traceback appropriately is desired, the following additional snippet is needed: if (tb != NULL) { PyException_SetTraceback(val, tb); } -- C Function: void PyErr_GetExcInfo (PyObject **ptype, PyObject **pvalue, PyObject **ptraceback) Retrieve the exception info, as known from ‘sys.exc_info()’. This refers to an exception that was `already caught', not to an exception that was freshly raised. Returns new references for the three objects, any of which may be ‘NULL’. Does not modify the exception info state. Note: This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use *note PyErr_SetExcInfo(): 3952. to restore or clear the exception state. New in version 3.3. -- C Function: void PyErr_SetExcInfo (PyObject *type, PyObject *value, PyObject *traceback) Set the exception info, as known from ‘sys.exc_info()’. This refers to an exception that was `already caught', not to an exception that was freshly raised. This function steals the references of the arguments. To clear the exception state, pass ‘NULL’ for all three arguments. For general rules about the three arguments, see *note PyErr_Restore(): 3897. Note: This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use *note PyErr_GetExcInfo(): 3951. to read the exception state. New in version 3.3.  File: python.info, Node: Signal Handling<2>, Next: Exception Classes, Prev: Querying the error indicator, Up: Exception Handling 7.5.5 Signal Handling --------------------- -- C Function: int PyErr_CheckSignals () This function interacts with Python’s signal handling. It checks whether a signal has been sent to the processes and if so, invokes the corresponding signal handler. If the *note signal: ea. module is supported, this can invoke a signal handler written in Python. In all cases, the default effect for ‘SIGINT’ is to raise the *note KeyboardInterrupt: 197. exception. If an exception is raised the error indicator is set and the function returns ‘-1’; otherwise the function returns ‘0’. The error indicator may or may not be cleared if it was previously set. -- C Function: void PyErr_SetInterrupt () Simulate the effect of a ‘SIGINT’ signal arriving. The next time *note PyErr_CheckSignals(): 393b. is called, the Python signal handler for ‘SIGINT’ will be called. If ‘SIGINT’ isn’t handled by Python (it was set to *note signal.SIG_DFL: 21c4. or *note signal.SIG_IGN: 21c5.), this function does nothing. -- C Function: int PySignal_SetWakeupFd (int fd) This utility function specifies a file descriptor to which the signal number is written as a single byte whenever a signal is received. `fd' must be non-blocking. It returns the previous such file descriptor. The value ‘-1’ disables the feature; this is the initial state. This is equivalent to *note signal.set_wakeup_fd(): 3ce. in Python, but without any error checking. `fd' should be a valid file descriptor. The function should only be called from the main thread. Changed in version 3.5: On Windows, the function now also supports socket handles.  File: python.info, Node: Exception Classes, Next: Exception Objects, Prev: Signal Handling<2>, Up: Exception Handling 7.5.6 Exception Classes ----------------------- -- C Function: PyObject* PyErr_NewException (const char *name, PyObject *base, PyObject *dict) `Return value: New reference.' This utility function creates and returns a new exception class. The `name' argument must be the name of the new exception, a C string of the form ‘module.classname’. The `base' and `dict' arguments are normally ‘NULL’. This creates a class object derived from *note Exception: 1a9. (accessible in C as ‘PyExc_Exception’). The ‘__module__’ attribute of the new class is set to the first part (up to the last dot) of the `name' argument, and the class name is set to the last part (after the last dot). The `base' argument can be used to specify alternate base classes; it can either be only one class or a tuple of classes. The `dict' argument can be used to specify a dictionary of class variables and methods. -- C Function: PyObject* PyErr_NewExceptionWithDoc (const char *name, const char *doc, PyObject *base, PyObject *dict) `Return value: New reference.' Same as *note PyErr_NewException(): c00, except that the new exception class can easily be given a docstring: If `doc' is non-‘NULL’, it will be used as the docstring for the exception class. New in version 3.2.  File: python.info, Node: Exception Objects, Next: Unicode Exception Objects, Prev: Exception Classes, Up: Exception Handling 7.5.7 Exception Objects ----------------------- -- C Function: PyObject* PyException_GetTraceback (PyObject *ex) `Return value: New reference.' Return the traceback associated with the exception as a new reference, as accessible from Python through ‘__traceback__’. If there is no traceback associated, this returns ‘NULL’. -- C Function: int PyException_SetTraceback (PyObject *ex, PyObject *tb) Set the traceback associated with the exception to `tb'. Use ‘Py_None’ to clear it. -- C Function: PyObject* PyException_GetContext (PyObject *ex) `Return value: New reference.' Return the context (another exception instance during whose handling `ex' was raised) associated with the exception as a new reference, as accessible from Python through ‘__context__’. If there is no context associated, this returns ‘NULL’. -- C Function: void PyException_SetContext (PyObject *ex, PyObject *ctx) Set the context associated with the exception to `ctx'. Use ‘NULL’ to clear it. There is no type check to make sure that `ctx' is an exception instance. This steals a reference to `ctx'. -- C Function: PyObject* PyException_GetCause (PyObject *ex) `Return value: New reference.' Return the cause (either an exception instance, or *note None: 157, set by ‘raise ... from ...’) associated with the exception as a new reference, as accessible from Python through ‘__cause__’. -- C Function: void PyException_SetCause (PyObject *ex, PyObject *cause) Set the cause associated with the exception to `cause'. Use ‘NULL’ to clear it. There is no type check to make sure that `cause' is either an exception instance or *note None: 157. This steals a reference to `cause'. ‘__suppress_context__’ is implicitly set to ‘True’ by this function.  File: python.info, Node: Unicode Exception Objects, Next: Recursion Control, Prev: Exception Objects, Up: Exception Handling 7.5.8 Unicode Exception Objects ------------------------------- The following functions are used to create and modify Unicode exceptions from C. -- C Function: PyObject* PyUnicodeDecodeError_Create (const char *encoding, const char *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason) `Return value: New reference.' Create a *note UnicodeDecodeError: 1fd. object with the attributes `encoding', `object', `length', `start', `end' and `reason'. `encoding' and `reason' are UTF-8 encoded strings. -- C Function: PyObject* PyUnicodeEncodeError_Create (const char *encoding, const Py_UNICODE *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason) `Return value: New reference.' Create a *note UnicodeEncodeError: 1fc. object with the attributes `encoding', `object', `length', `start', `end' and `reason'. `encoding' and `reason' are UTF-8 encoded strings. Deprecated since version 3.3: 3.11 ‘Py_UNICODE’ is deprecated since Python 3.3. Please migrate to ‘PyObject_CallFunction(PyExc_UnicodeEncodeError, "sOnns", ...)’. -- C Function: PyObject* PyUnicodeTranslateError_Create (const Py_UNICODE *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason) `Return value: New reference.' Create a *note UnicodeTranslateError: 13bd. object with the attributes `object', `length', `start', `end' and `reason'. `reason' is a UTF-8 encoded string. Deprecated since version 3.3: 3.11 ‘Py_UNICODE’ is deprecated since Python 3.3. Please migrate to ‘PyObject_CallFunction(PyExc_UnicodeTranslateError, "Onns", ...)’. -- C Function: PyObject* PyUnicodeDecodeError_GetEncoding (PyObject *exc) -- C Function: PyObject* PyUnicodeEncodeError_GetEncoding (PyObject *exc) `Return value: New reference.' Return the `encoding' attribute of the given exception object. -- C Function: PyObject* PyUnicodeDecodeError_GetObject (PyObject *exc) -- C Function: PyObject* PyUnicodeEncodeError_GetObject (PyObject *exc) -- C Function: PyObject* PyUnicodeTranslateError_GetObject (PyObject *exc) `Return value: New reference.' Return the `object' attribute of the given exception object. -- C Function: int PyUnicodeDecodeError_GetStart (PyObject *exc, Py_ssize_t *start) -- C Function: int PyUnicodeEncodeError_GetStart (PyObject *exc, Py_ssize_t *start) -- C Function: int PyUnicodeTranslateError_GetStart (PyObject *exc, Py_ssize_t *start) Get the `start' attribute of the given exception object and place it into `*start'. `start' must not be ‘NULL’. Return ‘0’ on success, ‘-1’ on failure. -- C Function: int PyUnicodeDecodeError_SetStart (PyObject *exc, Py_ssize_t start) -- C Function: int PyUnicodeEncodeError_SetStart (PyObject *exc, Py_ssize_t start) -- C Function: int PyUnicodeTranslateError_SetStart (PyObject *exc, Py_ssize_t start) Set the `start' attribute of the given exception object to `start'. Return ‘0’ on success, ‘-1’ on failure. -- C Function: int PyUnicodeDecodeError_GetEnd (PyObject *exc, Py_ssize_t *end) -- C Function: int PyUnicodeEncodeError_GetEnd (PyObject *exc, Py_ssize_t *end) -- C Function: int PyUnicodeTranslateError_GetEnd (PyObject *exc, Py_ssize_t *end) Get the `end' attribute of the given exception object and place it into `*end'. `end' must not be ‘NULL’. Return ‘0’ on success, ‘-1’ on failure. -- C Function: int PyUnicodeDecodeError_SetEnd (PyObject *exc, Py_ssize_t end) -- C Function: int PyUnicodeEncodeError_SetEnd (PyObject *exc, Py_ssize_t end) -- C Function: int PyUnicodeTranslateError_SetEnd (PyObject *exc, Py_ssize_t end) Set the `end' attribute of the given exception object to `end'. Return ‘0’ on success, ‘-1’ on failure. -- C Function: PyObject* PyUnicodeDecodeError_GetReason (PyObject *exc) -- C Function: PyObject* PyUnicodeEncodeError_GetReason (PyObject *exc) -- C Function: PyObject* PyUnicodeTranslateError_GetReason (PyObject *exc) `Return value: New reference.' Return the `reason' attribute of the given exception object. -- C Function: int PyUnicodeDecodeError_SetReason (PyObject *exc, const char *reason) -- C Function: int PyUnicodeEncodeError_SetReason (PyObject *exc, const char *reason) -- C Function: int PyUnicodeTranslateError_SetReason (PyObject *exc, const char *reason) Set the `reason' attribute of the given exception object to `reason'. Return ‘0’ on success, ‘-1’ on failure.  File: python.info, Node: Recursion Control, Next: Standard Exceptions, Prev: Unicode Exception Objects, Up: Exception Handling 7.5.9 Recursion Control ----------------------- These two functions provide a way to perform safe recursive calls at the C level, both in the core and in extension modules. They are needed if the recursive code does not necessarily invoke Python code (which tracks its recursion depth automatically). -- C Function: int Py_EnterRecursiveCall (const char *where) Marks a point where a recursive C-level call is about to be performed. If ‘USE_STACKCHECK’ is defined, this function checks if the OS stack overflowed using *note PyOS_CheckStack(): 397b. In this is the case, it sets a *note MemoryError: 13af. and returns a nonzero value. The function then checks if the recursion limit is reached. If this is the case, a *note RecursionError: 634. is set and a nonzero value is returned. Otherwise, zero is returned. `where' should be a string such as ‘" in instance check"’ to be concatenated to the *note RecursionError: 634. message caused by the recursion depth limit. -- C Function: void Py_LeaveRecursiveCall () Ends a *note Py_EnterRecursiveCall(): 397a. Must be called once for each `successful' invocation of *note Py_EnterRecursiveCall(): 397a. Properly implementing *note tp_repr: 389a. for container types requires special recursion handling. In addition to protecting the stack, *note tp_repr: 389a. also needs to track objects to prevent cycles. The following two functions facilitate this functionality. Effectively, these are the C equivalent to *note reprlib.recursive_repr(): b70. -- C Function: int Py_ReprEnter (PyObject *object) Called at the beginning of the *note tp_repr: 389a. implementation to detect cycles. If the object has already been processed, the function returns a positive integer. In that case the *note tp_repr: 389a. implementation should return a string object indicating a cycle. As examples, *note dict: 1b8. objects return ‘{...}’ and *note list: 262. objects return ‘[...]’. The function will return a negative integer if the recursion limit is reached. In that case the *note tp_repr: 389a. implementation should typically return ‘NULL’. Otherwise, the function returns zero and the *note tp_repr: 389a. implementation can continue normally. -- C Function: void Py_ReprLeave (PyObject *object) Ends a *note Py_ReprEnter(): 397d. Must be called once for each invocation of *note Py_ReprEnter(): 397d. that returns zero.  File: python.info, Node: Standard Exceptions, Next: Standard Warning Categories, Prev: Recursion Control, Up: Exception Handling 7.5.10 Standard Exceptions -------------------------- All standard Python exceptions are available as global variables whose names are ‘PyExc_’ followed by the Python exception name. These have the type *note PyObject*: 4ba.; they are all class objects. For completeness, here are all the variables: C Name Python Name Notes --------------------------------------------------------------------------------------------------- ‘PyExc_BaseException’ *note BaseException: 1a8. (1) ‘PyExc_Exception’ *note Exception: 1a9. (1) ‘PyExc_ArithmeticError’ *note ArithmeticError: 13a9. (1) ‘PyExc_AssertionError’ *note AssertionError: 1223. ‘PyExc_AttributeError’ *note AttributeError: 39b. ‘PyExc_BlockingIOError’ *note BlockingIOError: 997. ‘PyExc_BrokenPipeError’ *note BrokenPipeError: 99d. ‘PyExc_BufferError’ *note BufferError: 13ab. ‘PyExc_ChildProcessError’ *note ChildProcessError: 998. ‘PyExc_ConnectionAbortedError’ *note ConnectionAbortedError: 99e. ‘PyExc_ConnectionError’ *note ConnectionError: 6e6. ‘PyExc_ConnectionRefusedError’ *note ConnectionRefusedError: 99f. ‘PyExc_ConnectionResetError’ *note ConnectionResetError: 9a0. ‘PyExc_EOFError’ *note EOFError: c6c. ‘PyExc_FileExistsError’ *note FileExistsError: 958. ‘PyExc_FileNotFoundError’ *note FileNotFoundError: 7c0. ‘PyExc_FloatingPointError’ *note FloatingPointError: 13aa. ‘PyExc_GeneratorExit’ *note GeneratorExit: d32. ‘PyExc_ImportError’ *note ImportError: 334. ‘PyExc_IndentationError’ *note IndentationError: e78. ‘PyExc_IndexError’ *note IndexError: e75. ‘PyExc_InterruptedError’ *note InterruptedError: 659. ‘PyExc_IsADirectoryError’ *note IsADirectoryError: 999. ‘PyExc_KeyError’ *note KeyError: 2c7. ‘PyExc_KeyboardInterrupt’ *note KeyboardInterrupt: 197. ‘PyExc_LookupError’ *note LookupError: 1308. (1) ‘PyExc_MemoryError’ *note MemoryError: 13af. ‘PyExc_ModuleNotFoundError’ *note ModuleNotFoundError: 39a. ‘PyExc_NameError’ *note NameError: d7b. ‘PyExc_NotADirectoryError’ *note NotADirectoryError: 99a. ‘PyExc_NotImplementedError’ *note NotImplementedError: 60e. ‘PyExc_OSError’ *note OSError: 1d3. (1) ‘PyExc_OverflowError’ *note OverflowError: 960. ‘PyExc_PermissionError’ *note PermissionError: 5ff. ‘PyExc_ProcessLookupError’ *note ProcessLookupError: 99b. ‘PyExc_RecursionError’ *note RecursionError: 634. ‘PyExc_ReferenceError’ *note ReferenceError: e4d. (2) ‘PyExc_RuntimeError’ *note RuntimeError: 2ba. ‘PyExc_StopAsyncIteration’ *note StopAsyncIteration: 10cd. ‘PyExc_StopIteration’ *note StopIteration: 486. ‘PyExc_SyntaxError’ *note SyntaxError: 458. ‘PyExc_SystemError’ *note SystemError: 5fb. ‘PyExc_SystemExit’ *note SystemExit: 5fc. ‘PyExc_TabError’ *note TabError: e77. ‘PyExc_TimeoutError’ *note TimeoutError: 99c. ‘PyExc_TypeError’ *note TypeError: 192. ‘PyExc_UnboundLocalError’ *note UnboundLocalError: e76. ‘PyExc_UnicodeDecodeError’ *note UnicodeDecodeError: 1fd. ‘PyExc_UnicodeEncodeError’ *note UnicodeEncodeError: 1fc. ‘PyExc_UnicodeError’ *note UnicodeError: c3b. ‘PyExc_UnicodeTranslateError’ *note UnicodeTranslateError: 13bd. ‘PyExc_ValueError’ *note ValueError: 1fb. ‘PyExc_ZeroDivisionError’ *note ZeroDivisionError: f42. New in version 3.3: ‘PyExc_BlockingIOError’, ‘PyExc_BrokenPipeError’, ‘PyExc_ChildProcessError’, ‘PyExc_ConnectionError’, ‘PyExc_ConnectionAbortedError’, ‘PyExc_ConnectionRefusedError’, ‘PyExc_ConnectionResetError’, ‘PyExc_FileExistsError’, ‘PyExc_FileNotFoundError’, ‘PyExc_InterruptedError’, ‘PyExc_IsADirectoryError’, ‘PyExc_NotADirectoryError’, ‘PyExc_PermissionError’, ‘PyExc_ProcessLookupError’ and ‘PyExc_TimeoutError’ were introduced following PEP 3151(1). New in version 3.5: ‘PyExc_StopAsyncIteration’ and ‘PyExc_RecursionError’. New in version 3.6: ‘PyExc_ModuleNotFoundError’. These are compatibility aliases to ‘PyExc_OSError’: C Name Notes --------------------------------------------------------- ‘PyExc_EnvironmentError’ ‘PyExc_IOError’ ‘PyExc_WindowsError’ (3) Changed in version 3.3: These aliases used to be separate exception types. Notes: 1. This is a base class for other standard exceptions. 2. Only defined on Windows; protect code that uses this by testing that the preprocessor macro ‘MS_WINDOWS’ is defined. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3151  File: python.info, Node: Standard Warning Categories, Prev: Standard Exceptions, Up: Exception Handling 7.5.11 Standard Warning Categories ---------------------------------- All standard Python warning categories are available as global variables whose names are ‘PyExc_’ followed by the Python exception name. These have the type *note PyObject*: 4ba.; they are all class objects. For completeness, here are all the variables: C Name Python Name Notes ---------------------------------------------------------------------------------------------------- ‘PyExc_Warning’ *note Warning: 13c2. (1) ‘PyExc_BytesWarning’ *note BytesWarning: 4b5. ‘PyExc_DeprecationWarning’ *note DeprecationWarning: 278. ‘PyExc_FutureWarning’ *note FutureWarning: 325. ‘PyExc_ImportWarning’ *note ImportWarning: 5d8. ‘PyExc_PendingDeprecationWarning’ *note PendingDeprecationWarning: 279. ‘PyExc_ResourceWarning’ *note ResourceWarning: 4d0. ‘PyExc_RuntimeWarning’ *note RuntimeWarning: 2c0. ‘PyExc_SyntaxWarning’ *note SyntaxWarning: 191. ‘PyExc_UnicodeWarning’ *note UnicodeWarning: d87. ‘PyExc_UserWarning’ *note UserWarning: 13c3. New in version 3.2: ‘PyExc_ResourceWarning’. Notes: 1. This is a base class for other standard warning categories.  File: python.info, Node: Utilities<2>, Next: Abstract Objects Layer, Prev: Exception Handling, Up: Python/C API Reference Manual 7.6 Utilities ============= The functions in this chapter perform various utility tasks, ranging from helping C code be more portable across platforms, using Python modules from C, and parsing function arguments and constructing Python values from C values. * Menu: * Operating System Utilities:: * System Functions:: * Process Control:: * Importing Modules: Importing Modules<2>. * Data marshalling support:: * Parsing arguments and building values:: * String conversion and formatting:: * Reflection:: * Codec registry and support functions::  File: python.info, Node: Operating System Utilities, Next: System Functions, Up: Utilities<2> 7.6.1 Operating System Utilities -------------------------------- -- C Function: PyObject* PyOS_FSPath (PyObject *path) `Return value: New reference.' Return the file system representation for `path'. If the object is a *note str: 330. or *note bytes: 331. object, then its reference count is incremented. If the object implements the *note os.PathLike: 4eb. interface, then *note __fspath__(): 4ec. is returned as long as it is a *note str: 330. or *note bytes: 331. object. Otherwise *note TypeError: 192. is raised and ‘NULL’ is returned. New in version 3.6. -- C Function: int Py_FdIsInteractive (FILE *fp, const char *filename) Return true (nonzero) if the standard I/O file `fp' with name `filename' is deemed interactive. This is the case for files for which ‘isatty(fileno(fp))’ is true. If the global flag *note Py_InteractiveFlag: 3989. is true, this function also returns true if the `filename' pointer is ‘NULL’ or if the name is equal to one of the strings ‘'<stdin>'’ or ‘'???'’. -- C Function: void PyOS_BeforeFork () Function to prepare some internal state before a process fork. This should be called before calling ‘fork()’ or any similar function that clones the current process. Only available on systems where ‘fork()’ is defined. Warning: The C ‘fork()’ call should only be made from the *note “main” thread: 398a. (of the *note “main” interpreter: 398b.). The same is true for ‘PyOS_BeforeFork()’. New in version 3.7. -- C Function: void PyOS_AfterFork_Parent () Function to update some internal state after a process fork. This should be called from the parent process after calling ‘fork()’ or any similar function that clones the current process, regardless of whether process cloning was successful. Only available on systems where ‘fork()’ is defined. Warning: The C ‘fork()’ call should only be made from the *note “main” thread: 398a. (of the *note “main” interpreter: 398b.). The same is true for ‘PyOS_AfterFork_Parent()’. New in version 3.7. -- C Function: void PyOS_AfterFork_Child () Function to update internal interpreter state after a process fork. This must be called from the child process after calling ‘fork()’, or any similar function that clones the current process, if there is any chance the process will call back into the Python interpreter. Only available on systems where ‘fork()’ is defined. Warning: The C ‘fork()’ call should only be made from the *note “main” thread: 398a. (of the *note “main” interpreter: 398b.). The same is true for ‘PyOS_AfterFork_Child()’. New in version 3.7. See also ........ *note os.register_at_fork(): 3b6. allows registering custom Python functions to be called by *note PyOS_BeforeFork(): 432, *note PyOS_AfterFork_Parent(): 433. and *note PyOS_AfterFork_Child(): 2cd. -- C Function: void PyOS_AfterFork () Function to update some internal state after a process fork; this should be called in the new process if the Python interpreter will continue to be used. If a new executable is loaded into the new process, this function does not need to be called. Deprecated since version 3.7: This function is superseded by *note PyOS_AfterFork_Child(): 2cd. -- C Function: int PyOS_CheckStack () Return true when the interpreter runs out of stack space. This is a reliable check, but is only available when ‘USE_STACKCHECK’ is defined (currently on Windows using the Microsoft Visual C++ compiler). ‘USE_STACKCHECK’ will be defined automatically; you should never change the definition in your own code. -- C Function: PyOS_sighandler_t PyOS_getsig (int i) Return the current signal handler for signal `i'. This is a thin wrapper around either ‘sigaction()’ or ‘signal()’. Do not call those functions directly! ‘PyOS_sighandler_t’ is a typedef alias for ‘void (*)(int)’. -- C Function: PyOS_sighandler_t PyOS_setsig (int i, PyOS_sighandler_t h) Set the signal handler for signal `i' to be `h'; return the old signal handler. This is a thin wrapper around either ‘sigaction()’ or ‘signal()’. Do not call those functions directly! ‘PyOS_sighandler_t’ is a typedef alias for ‘void (*)(int)’. -- C Function: wchar_t* Py_DecodeLocale (const char* arg, size_t *size) Decode a byte string from the locale encoding with the *note surrogateescape error handler: 14f1.: undecodable bytes are decoded as characters in range U+DC80..U+DCFF. If a byte sequence can be decoded as a surrogate character, escape the bytes using the surrogateescape error handler instead of decoding them. Encoding, highest priority to lowest priority: * ‘UTF-8’ on macOS, Android, and VxWorks; * ‘UTF-8’ on Windows if *note Py_LegacyWindowsFSEncodingFlag: 398e. is zero; * ‘UTF-8’ if the Python UTF-8 mode is enabled; * ‘ASCII’ if the ‘LC_CTYPE’ locale is ‘"C"’, ‘nl_langinfo(CODESET)’ returns the ‘ASCII’ encoding (or an alias), and ‘mbstowcs()’ and ‘wcstombs()’ functions uses the ‘ISO-8859-1’ encoding. * the current locale encoding. Return a pointer to a newly allocated wide character string, use *note PyMem_RawFree(): 398f. to free the memory. If size is not ‘NULL’, write the number of wide characters excluding the null character into ‘*size’ Return ‘NULL’ on decoding error or memory allocation error. If `size' is not ‘NULL’, ‘*size’ is set to ‘(size_t)-1’ on memory error or set to ‘(size_t)-2’ on decoding error. Decoding errors should never happen, unless there is a bug in the C library. Use the *note Py_EncodeLocale(): 43d. function to encode the character string back to a byte string. See also ........ The *note PyUnicode_DecodeFSDefaultAndSize(): 3990. and *note PyUnicode_DecodeLocaleAndSize(): 43e. functions. New in version 3.5. Changed in version 3.7: The function now uses the UTF-8 encoding in the UTF-8 mode. Changed in version 3.8: The function now uses the UTF-8 encoding on Windows if *note Py_LegacyWindowsFSEncodingFlag: 398e. is zero; -- C Function: char* Py_EncodeLocale (const wchar_t *text, size_t *error_pos) Encode a wide character string to the locale encoding with the *note surrogateescape error handler: 14f1.: surrogate characters in the range U+DC80..U+DCFF are converted to bytes 0x80..0xFF. Encoding, highest priority to lowest priority: * ‘UTF-8’ on macOS, Android, and VxWorks; * ‘UTF-8’ on Windows if *note Py_LegacyWindowsFSEncodingFlag: 398e. is zero; * ‘UTF-8’ if the Python UTF-8 mode is enabled; * ‘ASCII’ if the ‘LC_CTYPE’ locale is ‘"C"’, ‘nl_langinfo(CODESET)’ returns the ‘ASCII’ encoding (or an alias), and ‘mbstowcs()’ and ‘wcstombs()’ functions uses the ‘ISO-8859-1’ encoding. * the current locale encoding. The function uses the UTF-8 encoding in the Python UTF-8 mode. Return a pointer to a newly allocated byte string, use *note PyMem_Free(): da9. to free the memory. Return ‘NULL’ on encoding error or memory allocation error If error_pos is not ‘NULL’, ‘*error_pos’ is set to ‘(size_t)-1’ on success, or set to the index of the invalid character on encoding error. Use the *note Py_DecodeLocale(): 43c. function to decode the bytes string back to a wide character string. See also ........ The *note PyUnicode_EncodeFSDefault(): 3991. and *note PyUnicode_EncodeLocale(): 43f. functions. New in version 3.5. Changed in version 3.7: The function now uses the UTF-8 encoding in the UTF-8 mode. Changed in version 3.8: The function now uses the UTF-8 encoding on Windows if *note Py_LegacyWindowsFSEncodingFlag: 398e. is zero;  File: python.info, Node: System Functions, Next: Process Control, Prev: Operating System Utilities, Up: Utilities<2> 7.6.2 System Functions ---------------------- These are utility functions that make functionality from the *note sys: fd. module accessible to C code. They all work with the current interpreter thread’s *note sys: fd. module’s dict, which is contained in the internal thread state structure. -- C Function: PyObject *PySys_GetObject (const char *name) `Return value: Borrowed reference.' Return the object `name' from the *note sys: fd. module or ‘NULL’ if it does not exist, without setting an exception. -- C Function: int PySys_SetObject (const char *name, PyObject *v) Set `name' in the *note sys: fd. module to `v' unless `v' is ‘NULL’, in which case `name' is deleted from the sys module. Returns ‘0’ on success, ‘-1’ on error. -- C Function: void PySys_ResetWarnOptions () Reset *note sys.warnoptions: 416. to an empty list. This function may be called prior to *note Py_Initialize(): 439. -- C Function: void PySys_AddWarnOption (const wchar_t *s) Append `s' to *note sys.warnoptions: 416. This function must be called prior to *note Py_Initialize(): 439. in order to affect the warnings filter list. -- C Function: void PySys_AddWarnOptionUnicode (PyObject *unicode) Append `unicode' to *note sys.warnoptions: 416. Note: this function is not currently usable from outside the CPython implementation, as it must be called prior to the implicit import of *note warnings: 126. in *note Py_Initialize(): 439. to be effective, but can’t be called until enough of the runtime has been initialized to permit the creation of Unicode objects. -- C Function: void PySys_SetPath (const wchar_t *path) Set *note sys.path: 488. to a list object of paths found in `path' which should be a list of paths separated with the platform’s search path delimiter (‘:’ on Unix, ‘;’ on Windows). -- C Function: void PySys_WriteStdout (const char *format, ...) Write the output string described by `format' to *note sys.stdout: 30e. No exceptions are raised, even if truncation occurs (see below). `format' should limit the total size of the formatted output string to 1000 bytes or less – after 1000 bytes, the output string is truncated. In particular, this means that no unrestricted “%s” formats should occur; these should be limited using “%.<N>s” where <N> is a decimal number calculated so that <N> plus the maximum size of other formatted text does not exceed 1000 bytes. Also watch out for “%f”, which can print hundreds of digits for very large numbers. If a problem occurs, or *note sys.stdout: 30e. is unset, the formatted message is written to the real (C level) `stdout'. -- C Function: void PySys_WriteStderr (const char *format, ...) As *note PySys_WriteStdout(): 3998, but write to *note sys.stderr: 30f. or `stderr' instead. -- C Function: void PySys_FormatStdout (const char *format, ...) Function similar to PySys_WriteStdout() but format the message using *note PyUnicode_FromFormatV(): 399b. and don’t truncate the message to an arbitrary length. New in version 3.2. -- C Function: void PySys_FormatStderr (const char *format, ...) As *note PySys_FormatStdout(): 399a, but write to *note sys.stderr: 30f. or `stderr' instead. New in version 3.2. -- C Function: void PySys_AddXOption (const wchar_t *s) Parse `s' as a set of *note -X: 155. options and add them to the current options mapping as returned by *note PySys_GetXOptions(): 399e. This function may be called prior to *note Py_Initialize(): 439. New in version 3.2. -- C Function: PyObject *PySys_GetXOptions () `Return value: Borrowed reference.' Return the current dictionary of *note -X: 155. options, similarly to *note sys._xoptions: fec. On error, ‘NULL’ is returned and an exception is set. New in version 3.2. -- C Function: int PySys_Audit (const char *event, const char *format, ...) Raise an auditing event with any active hooks. Return zero for success and non-zero with an exception set on failure. If any hooks have been added, `format' and other arguments will be used to construct a tuple to pass. Apart from ‘N’, the same format characters as used in *note Py_BuildValue(): 2ce. are available. If the built value is not a tuple, it will be added into a single-element tuple. (The ‘N’ format option consumes a reference, but since there is no way to know whether arguments to this function will be consumed, using it may cause reference leaks.) Note that ‘#’ format characters should always be treated as ‘Py_ssize_t’, regardless of whether ‘PY_SSIZE_T_CLEAN’ was defined. *note sys.audit(): 31ea. performs the same function from Python code. New in version 3.8. Changed in version 3.8.2: Require ‘Py_ssize_t’ for ‘#’ format characters. Previously, an unavoidable deprecation warning was raised. -- C Function: int PySys_AddAuditHook (Py_AuditHookFunction hook, void *userData) Append the callable `hook' to the list of active auditing hooks. Return zero for success and non-zero on failure. If the runtime has been initialized, also set an error on failure. Hooks added through this API are called for all interpreters created by the runtime. The `userData' pointer is passed into the hook function. Since hook functions may be called from different runtimes, this pointer should not refer directly to Python state. This function is safe to call before *note Py_Initialize(): 439. When called after runtime initialization, existing audit hooks are notified and may silently abort the operation by raising an error subclassed from *note Exception: 1a9. (other errors will not be silenced). The hook function is of type ‘int (*)(const char *event, PyObject *args, void *userData)’, where `args' is guaranteed to be a *note PyTupleObject: 399f. The hook function is always called with the GIL held by the Python interpreter that raised the event. See PEP 578(1) for a detailed description of auditing. Functions in the runtime and standard library that raise events are listed in the *note audit events table: 31e7. Details are in each function’s documentation. If the interpreter is initialized, this function raises a auditing event ‘sys.addaudithook’ with no arguments. If any existing hooks raise an exception derived from *note Exception: 1a9, the new hook will not be added and the exception is cleared. As a result, callers cannot assume that their hook has been added unless they control all existing hooks. New in version 3.8. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0578  File: python.info, Node: Process Control, Next: Importing Modules<2>, Prev: System Functions, Up: Utilities<2> 7.6.3 Process Control --------------------- -- C Function: void Py_FatalError (const char *message) Print a fatal error message and kill the process. No cleanup is performed. This function should only be invoked when a condition is detected that would make it dangerous to continue using the Python interpreter; e.g., when the object administration appears to be corrupted. On Unix, the standard C library function ‘abort()’ is called which will attempt to produce a ‘core’ file. -- C Function: void Py_Exit (int status) Exit the current process. This calls *note Py_FinalizeEx(): 5c9. and then calls the standard C library function ‘exit(status)’. If *note Py_FinalizeEx(): 5c9. indicates an error, the exit status is set to 120. Changed in version 3.6: Errors from finalization no longer ignored. -- C Function: int Py_AtExit (void (*func)()) Register a cleanup function to be called by *note Py_FinalizeEx(): 5c9. The cleanup function will be called with no arguments and should return no value. At most 32 cleanup functions can be registered. When the registration is successful, *note Py_AtExit(): 39a3. returns ‘0’; on failure, it returns ‘-1’. The cleanup function registered last is called first. Each cleanup function will be called at most once. Since Python’s internal finalization will have completed before the cleanup function, no Python APIs should be called by `func'.  File: python.info, Node: Importing Modules<2>, Next: Data marshalling support, Prev: Process Control, Up: Utilities<2> 7.6.4 Importing Modules ----------------------- -- C Function: PyObject* PyImport_ImportModule (const char *name) `Return value: New reference.' This is a simplified interface to *note PyImport_ImportModuleEx(): b21. below, leaving the `globals' and `locals' arguments set to ‘NULL’ and `level' set to 0. When the `name' argument contains a dot (when it specifies a submodule of a package), the `fromlist' argument is set to the list ‘['*']’ so that the return value is the named module rather than the top-level package containing it as would otherwise be the case. (Unfortunately, this has an additional side effect when `name' in fact specifies a subpackage instead of a submodule: the submodules specified in the package’s ‘__all__’ variable are loaded.) Return a new reference to the imported module, or ‘NULL’ with an exception set on failure. A failing import of a module doesn’t leave the module in *note sys.modules: 1152. This function always uses absolute imports. -- C Function: PyObject* PyImport_ImportModuleNoBlock (const char *name) `Return value: New reference.' This function is a deprecated alias of *note PyImport_ImportModule(): c73. Changed in version 3.3: This function used to fail immediately when the import lock was held by another thread. In Python 3.3 though, the locking scheme switched to per-module locks for most purposes, so this function’s special behaviour isn’t needed anymore. -- C Function: PyObject* PyImport_ImportModuleEx (const char *name, PyObject *globals, PyObject *locals, PyObject *fromlist) `Return value: New reference.' Import a module. This is best described by referring to the built-in Python function *note __import__(): 610. The return value is a new reference to the imported module or top-level package, or ‘NULL’ with an exception set on failure. Like for *note __import__(): 610, the return value when a submodule of a package was requested is normally the top-level package, unless a non-empty `fromlist' was given. Failing imports remove incomplete module objects, like with *note PyImport_ImportModule(): c73. -- C Function: PyObject* PyImport_ImportModuleLevelObject (PyObject *name, PyObject *globals, PyObject *locals, PyObject *fromlist, int level) `Return value: New reference.' Import a module. This is best described by referring to the built-in Python function *note __import__(): 610, as the standard *note __import__(): 610. function calls this function directly. The return value is a new reference to the imported module or top-level package, or ‘NULL’ with an exception set on failure. Like for *note __import__(): 610, the return value when a submodule of a package was requested is normally the top-level package, unless a non-empty `fromlist' was given. New in version 3.3. -- C Function: PyObject* PyImport_ImportModuleLevel (const char *name, PyObject *globals, PyObject *locals, PyObject *fromlist, int level) `Return value: New reference.' Similar to *note PyImport_ImportModuleLevelObject(): 39a7, but the name is a UTF-8 encoded string instead of a Unicode object. Changed in version 3.3: Negative values for `level' are no longer accepted. -- C Function: PyObject* PyImport_Import (PyObject *name) `Return value: New reference.' This is a higher-level interface that calls the current “import hook function” (with an explicit `level' of 0, meaning absolute import). It invokes the *note __import__(): 610. function from the ‘__builtins__’ of the current globals. This means that the import is done using whatever import hooks are installed in the current environment. This function always uses absolute imports. -- C Function: PyObject* PyImport_ReloadModule (PyObject *m) `Return value: New reference.' Reload a module. Return a new reference to the reloaded module, or ‘NULL’ with an exception set on failure (the module still exists in this case). -- C Function: PyObject* PyImport_AddModuleObject (PyObject *name) `Return value: Borrowed reference.' Return the module object corresponding to a module name. The `name' argument may be of the form ‘package.module’. First check the modules dictionary if there’s one there, and if not, create a new one and insert it in the modules dictionary. Return ‘NULL’ with an exception set on failure. Note: This function does not load or import the module; if the module wasn’t already loaded, you will get an empty module object. Use *note PyImport_ImportModule(): c73. or one of its variants to import a module. Package structures implied by a dotted name for `name' are not created if not already present. New in version 3.3. -- C Function: PyObject* PyImport_AddModule (const char *name) `Return value: Borrowed reference.' Similar to *note PyImport_AddModuleObject(): 39a9, but the name is a UTF-8 encoded string instead of a Unicode object. -- C Function: PyObject* PyImport_ExecCodeModule (const char *name, PyObject *co) `Return value: New reference.' Given a module name (possibly of the form ‘package.module’) and a code object read from a Python bytecode file or obtained from the built-in function *note compile(): 1b4, load the module. Return a new reference to the module object, or ‘NULL’ with an exception set if an error occurred. `name' is removed from *note sys.modules: 1152. in error cases, even if `name' was already in *note sys.modules: 1152. on entry to *note PyImport_ExecCodeModule(): 39aa. Leaving incompletely initialized modules in *note sys.modules: 1152. is dangerous, as imports of such modules have no way to know that the module object is an unknown (and probably damaged with respect to the module author’s intents) state. The module’s *note __spec__: 116d. and *note __loader__: 956. will be set, if not set already, with the appropriate values. The spec’s loader will be set to the module’s ‘__loader__’ (if set) and to an instance of ‘SourceFileLoader’ otherwise. The module’s *note __file__: 10d0. attribute will be set to the code object’s ‘co_filename’. If applicable, *note __cached__: b32. will also be set. This function will reload the module if it was already imported. See *note PyImport_ReloadModule(): 39a8. for the intended way to reload a module. If `name' points to a dotted name of the form ‘package.module’, any package structures not already created will still not be created. See also *note PyImport_ExecCodeModuleEx(): 39ab. and *note PyImport_ExecCodeModuleWithPathnames(): 39ac. -- C Function: PyObject* PyImport_ExecCodeModuleEx (const char *name, PyObject *co, const char *pathname) `Return value: New reference.' Like *note PyImport_ExecCodeModule(): 39aa, but the *note __file__: 10d0. attribute of the module object is set to `pathname' if it is non-‘NULL’. See also *note PyImport_ExecCodeModuleWithPathnames(): 39ac. -- C Function: PyObject* PyImport_ExecCodeModuleObject (PyObject *name, PyObject *co, PyObject *pathname, PyObject *cpathname) `Return value: New reference.' Like *note PyImport_ExecCodeModuleEx(): 39ab, but the *note __cached__: b32. attribute of the module object is set to `cpathname' if it is non-‘NULL’. Of the three functions, this is the preferred one to use. New in version 3.3. -- C Function: PyObject* PyImport_ExecCodeModuleWithPathnames (const char *name, PyObject *co, const char *pathname, const char *cpathname) `Return value: New reference.' Like *note PyImport_ExecCodeModuleObject(): 39ad, but `name', `pathname' and `cpathname' are UTF-8 encoded strings. Attempts are also made to figure out what the value for `pathname' should be from `cpathname' if the former is set to ‘NULL’. New in version 3.2. Changed in version 3.3: Uses *note imp.source_from_cache(): 3825. in calculating the source path if only the bytecode path is provided. -- C Function: long PyImport_GetMagicNumber () Return the magic number for Python bytecode files (a.k.a. ‘.pyc’ file). The magic number should be present in the first four bytes of the bytecode file, in little-endian byte order. Returns ‘-1’ on error. Changed in version 3.3: Return value of ‘-1’ upon failure. -- C Function: const char * PyImport_GetMagicTag () Return the magic tag string for PEP 3147(1) format Python bytecode file names. Keep in mind that the value at ‘sys.implementation.cache_tag’ is authoritative and should be used instead of this function. New in version 3.2. -- C Function: PyObject* PyImport_GetModuleDict () `Return value: Borrowed reference.' Return the dictionary used for the module administration (a.k.a. ‘sys.modules’). Note that this is a per-interpreter variable. -- C Function: PyObject* PyImport_GetModule (PyObject *name) `Return value: New reference.' Return the already imported module with the given name. If the module has not been imported yet then returns ‘NULL’ but does not set an error. Returns ‘NULL’ and sets an error if the lookup failed. New in version 3.7. -- C Function: PyObject* PyImport_GetImporter (PyObject *path) `Return value: New reference.' Return a finder object for a *note sys.path: 488./‘pkg.__path__’ item `path', possibly by fetching it from the *note sys.path_importer_cache: 49d. dict. If it wasn’t yet cached, traverse *note sys.path_hooks: 95c. until a hook is found that can handle the path item. Return ‘None’ if no hook could; this tells our caller that the *note path based finder: 1165. could not find a finder for this path item. Cache the result in *note sys.path_importer_cache: 49d. Return a new reference to the finder object. -- C Function: void _PyImport_Init () Initialize the import mechanism. For internal use only. -- C Function: void PyImport_Cleanup () Empty the module table. For internal use only. -- C Function: void _PyImport_Fini () Finalize the import mechanism. For internal use only. -- C Function: int PyImport_ImportFrozenModuleObject (PyObject *name) `Return value: New reference.' Load a frozen module named `name'. Return ‘1’ for success, ‘0’ if the module is not found, and ‘-1’ with an exception set if the initialization failed. To access the imported module on a successful load, use *note PyImport_ImportModule(): c73. (Note the misnomer — this function would reload the module if it was already imported.) New in version 3.3. Changed in version 3.4: The ‘__file__’ attribute is no longer set on the module. -- C Function: int PyImport_ImportFrozenModule (const char *name) Similar to *note PyImport_ImportFrozenModuleObject(): 39b4, but the name is a UTF-8 encoded string instead of a Unicode object. -- C Type: struct _frozen This is the structure type definition for frozen module descriptors, as generated by the ‘freeze’ utility (see ‘Tools/freeze/’ in the Python source distribution). Its definition, found in ‘Include/import.h’, is: struct _frozen { const char *name; const unsigned char *code; int size; }; -- C Variable: const struct _frozen* PyImport_FrozenModules This pointer is initialized to point to an array of ‘struct _frozen’ records, terminated by one whose members are all ‘NULL’ or zero. When a frozen module is imported, it is searched in this table. Third-party code could play tricks with this to provide a dynamically created collection of frozen modules. -- C Function: int PyImport_AppendInittab (const char *name, PyObject* (*initfunc)(void)) Add a single module to the existing table of built-in modules. This is a convenience wrapper around *note PyImport_ExtendInittab(): 39b7, returning ‘-1’ if the table could not be extended. The new module can be imported by the name `name', and uses the function `initfunc' as the initialization function called on the first attempted import. This should be called before *note Py_Initialize(): 439. -- C Type: struct _inittab Structure describing a single entry in the list of built-in modules. Each of these structures gives the name and initialization function for a module built into the interpreter. The name is an ASCII encoded string. Programs which embed Python may use an array of these structures in conjunction with *note PyImport_ExtendInittab(): 39b7. to provide additional built-in modules. The structure is defined in ‘Include/import.h’ as: struct _inittab { const char *name; /* ASCII encoded string */ PyObject* (*initfunc)(void); }; -- C Function: int PyImport_ExtendInittab (struct _inittab *newtab) Add a collection of modules to the table of built-in modules. The `newtab' array must end with a sentinel entry which contains ‘NULL’ for the ‘name’ field; failure to provide the sentinel value can result in a memory fault. Returns ‘0’ on success or ‘-1’ if insufficient memory could be allocated to extend the internal table. In the event of failure, no modules are added to the internal table. This should be called before *note Py_Initialize(): 439. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: Data marshalling support, Next: Parsing arguments and building values, Prev: Importing Modules<2>, Up: Utilities<2> 7.6.5 Data marshalling support ------------------------------ These routines allow C code to work with serialized objects using the same data format as the *note marshal: b0. module. There are functions to write data into the serialization format, and additional functions that can be used to read the data back. Files used to store marshalled data must be opened in binary mode. Numeric values are stored with the least significant byte first. The module supports two versions of the data format: version 0 is the historical version, version 1 shares interned strings in the file, and upon unmarshalling. Version 2 uses a binary format for floating point numbers. ‘Py_MARSHAL_VERSION’ indicates the current file format (currently 2). -- C Function: void PyMarshal_WriteLongToFile (long value, FILE *file, int version) Marshal a ‘long’ integer, `value', to `file'. This will only write the least-significant 32 bits of `value'; regardless of the size of the native ‘long’ type. `version' indicates the file format. -- C Function: void PyMarshal_WriteObjectToFile (PyObject *value, FILE *file, int version) Marshal a Python object, `value', to `file'. `version' indicates the file format. -- C Function: PyObject* PyMarshal_WriteObjectToString (PyObject *value, int version) `Return value: New reference.' Return a bytes object containing the marshalled representation of `value'. `version' indicates the file format. The following functions allow marshalled values to be read back in. -- C Function: long PyMarshal_ReadLongFromFile (FILE *file) Return a C ‘long’ from the data stream in a ‘FILE*’ opened for reading. Only a 32-bit value can be read in using this function, regardless of the native size of ‘long’. On error, sets the appropriate exception (*note EOFError: c6c.) and returns ‘-1’. -- C Function: int PyMarshal_ReadShortFromFile (FILE *file) Return a C ‘short’ from the data stream in a ‘FILE*’ opened for reading. Only a 16-bit value can be read in using this function, regardless of the native size of ‘short’. On error, sets the appropriate exception (*note EOFError: c6c.) and returns ‘-1’. -- C Function: PyObject* PyMarshal_ReadObjectFromFile (FILE *file) `Return value: New reference.' Return a Python object from the data stream in a ‘FILE*’ opened for reading. On error, sets the appropriate exception (*note EOFError: c6c, *note ValueError: 1fb. or *note TypeError: 192.) and returns ‘NULL’. -- C Function: PyObject* PyMarshal_ReadLastObjectFromFile (FILE *file) `Return value: New reference.' Return a Python object from the data stream in a ‘FILE*’ opened for reading. Unlike *note PyMarshal_ReadObjectFromFile(): 39c1, this function assumes that no further objects will be read from the file, allowing it to aggressively load file data into memory so that the de-serialization can operate from data in memory rather than reading a byte at a time from the file. Only use these variant if you are certain that you won’t be reading anything else from the file. On error, sets the appropriate exception (*note EOFError: c6c, *note ValueError: 1fb. or *note TypeError: 192.) and returns ‘NULL’. -- C Function: PyObject* PyMarshal_ReadObjectFromString (const char *data, Py_ssize_t len) `Return value: New reference.' Return a Python object from the data stream in a byte buffer containing `len' bytes pointed to by `data'. On error, sets the appropriate exception (*note EOFError: c6c, *note ValueError: 1fb. or *note TypeError: 192.) and returns ‘NULL’.  File: python.info, Node: Parsing arguments and building values, Next: String conversion and formatting, Prev: Data marshalling support, Up: Utilities<2> 7.6.6 Parsing arguments and building values ------------------------------------------- These functions are useful when creating your own extensions functions and methods. Additional information and examples are available in *note Extending and Embedding the Python Interpreter: e90. The first three of these functions described, *note PyArg_ParseTuple(): 26a, *note PyArg_ParseTupleAndKeywords(): 5ca, and *note PyArg_Parse(): 39c6, all use `format strings' which are used to tell the function about the expected arguments. The format strings use the same syntax for each of these functions. * Menu: * Parsing arguments: Parsing arguments<3>. * Building values::  File: python.info, Node: Parsing arguments<3>, Next: Building values, Up: Parsing arguments and building values 7.6.6.1 Parsing arguments ......................... A format string consists of zero or more “format units.” A format unit describes one Python object; it is usually a single character or a parenthesized sequence of format units. With a few exceptions, a format unit that is not a parenthesized sequence normally corresponds to a single address argument to these functions. In the following description, the quoted form is the format unit; the entry in (round) parentheses is the Python object type that matches the format unit; and the entry in [square] brackets is the type of the C variable(s) whose address should be passed. * Menu: * Strings and buffers:: * Numbers: Numbers<2>. * Other objects:: * API Functions::  File: python.info, Node: Strings and buffers, Next: Numbers<2>, Up: Parsing arguments<3> 7.6.6.2 Strings and buffers ........................... These formats allow accessing an object as a contiguous chunk of memory. You don’t have to provide raw storage for the returned unicode or bytes area. In general, when a format sets a pointer to a buffer, the buffer is managed by the corresponding Python object, and the buffer shares the lifetime of this object. You won’t have to release any memory yourself. The only exceptions are ‘es’, ‘es#’, ‘et’ and ‘et#’. However, when a *note Py_buffer: b1b. structure gets filled, the underlying buffer is locked so that the caller can subsequently use the buffer even inside a *note Py_BEGIN_ALLOW_THREADS: 3866. block without the risk of mutable data being resized or destroyed. As a result, `you have to call' *note PyBuffer_Release(): d54. after you have finished processing the data (or in any early abort case). Unless otherwise stated, buffers are not NUL-terminated. Some formats require a read-only *note bytes-like object: 5e8, and set a pointer instead of a buffer structure. They work by checking that the object’s *note PyBufferProcs.bf_releasebuffer: 39c9. field is ‘NULL’, which disallows mutable objects such as *note bytearray: 332. Note: For all ‘#’ variants of formats (‘s#’, ‘y#’, etc.), the type of the length argument (int or ‘Py_ssize_t’) is controlled by defining the macro ‘PY_SSIZE_T_CLEAN’ before including ‘Python.h’. If the macro was defined, length is a ‘Py_ssize_t’ rather than an ‘int’. This behavior will change in a future Python version to only support ‘Py_ssize_t’ and drop ‘int’ support. It is best to always define ‘PY_SSIZE_T_CLEAN’. ‘s’ (*note str: 330.) [const char *] Convert a Unicode object to a C pointer to a character string. A pointer to an existing string is stored in the character pointer variable whose address you pass. The C string is NUL-terminated. The Python string must not contain embedded null code points; if it does, a *note ValueError: 1fb. exception is raised. Unicode objects are converted to C strings using ‘'utf-8'’ encoding. If this conversion fails, a *note UnicodeError: c3b. is raised. Note: This format does not accept *note bytes-like objects: 5e8. If you want to accept filesystem paths and convert them to C character strings, it is preferable to use the ‘O&’ format with *note PyUnicode_FSConverter(): 5ce. as `converter'. Changed in version 3.5: Previously, *note TypeError: 192. was raised when embedded null code points were encountered in the Python string. ‘s*’ (*note str: 330. or *note bytes-like object: 5e8.) [Py_buffer] This format accepts Unicode objects as well as bytes-like objects. It fills a *note Py_buffer: b1b. structure provided by the caller. In this case the resulting C string may contain embedded NUL bytes. Unicode objects are converted to C strings using ‘'utf-8'’ encoding. ‘s#’ (*note str: 330, read-only *note bytes-like object: 5e8.) [const char *, int or ‘Py_ssize_t’] Like ‘s*’, except that it doesn’t accept mutable objects. The result is stored into two C variables, the first one a pointer to a C string, the second one its length. The string may contain embedded null bytes. Unicode objects are converted to C strings using ‘'utf-8'’ encoding. ‘z’ (*note str: 330. or ‘None’) [const char *] Like ‘s’, but the Python object may also be ‘None’, in which case the C pointer is set to ‘NULL’. ‘z*’ (*note str: 330, *note bytes-like object: 5e8. or ‘None’) [Py_buffer] Like ‘s*’, but the Python object may also be ‘None’, in which case the ‘buf’ member of the *note Py_buffer: b1b. structure is set to ‘NULL’. ‘z#’ (*note str: 330, read-only *note bytes-like object: 5e8. or ‘None’) [const char *, int or ‘Py_ssize_t’] Like ‘s#’, but the Python object may also be ‘None’, in which case the C pointer is set to ‘NULL’. ‘y’ (read-only *note bytes-like object: 5e8.) [const char *] This format converts a bytes-like object to a C pointer to a character string; it does not accept Unicode objects. The bytes buffer must not contain embedded null bytes; if it does, a *note ValueError: 1fb. exception is raised. Changed in version 3.5: Previously, *note TypeError: 192. was raised when embedded null bytes were encountered in the bytes buffer. ‘y*’ (*note bytes-like object: 5e8.) [Py_buffer] This variant on ‘s*’ doesn’t accept Unicode objects, only bytes-like objects. `This is the recommended way to accept binary data.' ‘y#’ (read-only *note bytes-like object: 5e8.) [const char *, int or ‘Py_ssize_t’] This variant on ‘s#’ doesn’t accept Unicode objects, only bytes-like objects. ‘S’ (*note bytes: 331.) [PyBytesObject *] Requires that the Python object is a *note bytes: 331. object, without attempting any conversion. Raises *note TypeError: 192. if the object is not a bytes object. The C variable may also be declared as *note PyObject*: 4ba. ‘Y’ (*note bytearray: 332.) [PyByteArrayObject *] Requires that the Python object is a *note bytearray: 332. object, without attempting any conversion. Raises *note TypeError: 192. if the object is not a *note bytearray: 332. object. The C variable may also be declared as *note PyObject*: 4ba. ‘u’ (*note str: 330.) [const Py_UNICODE *] Convert a Python Unicode object to a C pointer to a NUL-terminated buffer of Unicode characters. You must pass the address of a *note Py_UNICODE: aee. pointer variable, which will be filled with the pointer to an existing Unicode buffer. Please note that the width of a *note Py_UNICODE: aee. character depends on compilation options (it is either 16 or 32 bits). The Python string must not contain embedded null code points; if it does, a *note ValueError: 1fb. exception is raised. Changed in version 3.5: Previously, *note TypeError: 192. was raised when embedded null code points were encountered in the Python string. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsWideCharString(): 438. ‘u#’ (*note str: 330.) [const Py_UNICODE *, int or ‘Py_ssize_t’] This variant on ‘u’ stores into two C variables, the first one a pointer to a Unicode data buffer, the second one its length. This variant allows null code points. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsWideCharString(): 438. ‘Z’ (*note str: 330. or ‘None’) [const Py_UNICODE *] Like ‘u’, but the Python object may also be ‘None’, in which case the *note Py_UNICODE: aee. pointer is set to ‘NULL’. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsWideCharString(): 438. ‘Z#’ (*note str: 330. or ‘None’) [const Py_UNICODE *, int or ‘Py_ssize_t’] Like ‘u#’, but the Python object may also be ‘None’, in which case the *note Py_UNICODE: aee. pointer is set to ‘NULL’. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsWideCharString(): 438. ‘U’ (*note str: 330.) [PyObject *] Requires that the Python object is a Unicode object, without attempting any conversion. Raises *note TypeError: 192. if the object is not a Unicode object. The C variable may also be declared as *note PyObject*: 4ba. ‘w*’ (read-write *note bytes-like object: 5e8.) [Py_buffer] This format accepts any object which implements the read-write buffer interface. It fills a *note Py_buffer: b1b. structure provided by the caller. The buffer may contain embedded null bytes. The caller have to call *note PyBuffer_Release(): d54. when it is done with the buffer. ‘es’ (*note str: 330.) [const char *encoding, char **buffer] This variant on ‘s’ is used for encoding Unicode into a character buffer. It only works for encoded data without embedded NUL bytes. This format requires two arguments. The first is only used as input, and must be a ‘const char*’ which points to the name of an encoding as a NUL-terminated string, or ‘NULL’, in which case ‘'utf-8'’ encoding is used. An exception is raised if the named encoding is not known to Python. The second argument must be a ‘char**’; the value of the pointer it references will be set to a buffer with the contents of the argument text. The text will be encoded in the encoding specified by the first argument. *note PyArg_ParseTuple(): 26a. will allocate a buffer of the needed size, copy the encoded data into this buffer and adjust `*buffer' to reference the newly allocated storage. The caller is responsible for calling *note PyMem_Free(): da9. to free the allocated buffer after use. ‘et’ (*note str: 330, *note bytes: 331. or *note bytearray: 332.) [const char *encoding, char **buffer] Same as ‘es’ except that byte string objects are passed through without recoding them. Instead, the implementation assumes that the byte string object uses the encoding passed in as parameter. ‘es#’ (*note str: 330.) [const char *encoding, char **buffer, int or ‘Py_ssize_t’ *buffer_length] This variant on ‘s#’ is used for encoding Unicode into a character buffer. Unlike the ‘es’ format, this variant allows input data which contains NUL characters. It requires three arguments. The first is only used as input, and must be a ‘const char*’ which points to the name of an encoding as a NUL-terminated string, or ‘NULL’, in which case ‘'utf-8'’ encoding is used. An exception is raised if the named encoding is not known to Python. The second argument must be a ‘char**’; the value of the pointer it references will be set to a buffer with the contents of the argument text. The text will be encoded in the encoding specified by the first argument. The third argument must be a pointer to an integer; the referenced integer will be set to the number of bytes in the output buffer. There are two modes of operation: If `*buffer' points a ‘NULL’ pointer, the function will allocate a buffer of the needed size, copy the encoded data into this buffer and set `*buffer' to reference the newly allocated storage. The caller is responsible for calling *note PyMem_Free(): da9. to free the allocated buffer after usage. If `*buffer' points to a non-‘NULL’ pointer (an already allocated buffer), *note PyArg_ParseTuple(): 26a. will use this location as the buffer and interpret the initial value of `*buffer_length' as the buffer size. It will then copy the encoded data into the buffer and NUL-terminate it. If the buffer is not large enough, a *note ValueError: 1fb. will be set. In both cases, `*buffer_length' is set to the length of the encoded data without the trailing NUL byte. ‘et#’ (*note str: 330, *note bytes: 331. or *note bytearray: 332.) [const char *encoding, char **buffer, int or ‘Py_ssize_t’ *buffer_length] Same as ‘es#’ except that byte string objects are passed through without recoding them. Instead, the implementation assumes that the byte string object uses the encoding passed in as parameter.  File: python.info, Node: Numbers<2>, Next: Other objects, Prev: Strings and buffers, Up: Parsing arguments<3> 7.6.6.3 Numbers ............... ‘b’ (*note int: 184.) [unsigned char] Convert a nonnegative Python integer to an unsigned tiny int, stored in a C ‘unsigned char’. ‘B’ (*note int: 184.) [unsigned char] Convert a Python integer to a tiny int without overflow checking, stored in a C ‘unsigned char’. ‘h’ (*note int: 184.) [short int] Convert a Python integer to a C ‘short int’. ‘H’ (*note int: 184.) [unsigned short int] Convert a Python integer to a C ‘unsigned short int’, without overflow checking. ‘i’ (*note int: 184.) [int] Convert a Python integer to a plain C ‘int’. ‘I’ (*note int: 184.) [unsigned int] Convert a Python integer to a C ‘unsigned int’, without overflow checking. ‘l’ (*note int: 184.) [long int] Convert a Python integer to a C ‘long int’. ‘k’ (*note int: 184.) [unsigned long] Convert a Python integer to a C ‘unsigned long’ without overflow checking. ‘L’ (*note int: 184.) [long long] Convert a Python integer to a C ‘long long’. ‘K’ (*note int: 184.) [unsigned long long] Convert a Python integer to a C ‘unsigned long long’ without overflow checking. ‘n’ (*note int: 184.) [Py_ssize_t] Convert a Python integer to a C ‘Py_ssize_t’. ‘c’ (*note bytes: 331. or *note bytearray: 332. of length 1) [char] Convert a Python byte, represented as a *note bytes: 331. or *note bytearray: 332. object of length 1, to a C ‘char’. Changed in version 3.3: Allow *note bytearray: 332. objects. ‘C’ (*note str: 330. of length 1) [int] Convert a Python character, represented as a *note str: 330. object of length 1, to a C ‘int’. ‘f’ (*note float: 187.) [float] Convert a Python floating point number to a C ‘float’. ‘d’ (*note float: 187.) [double] Convert a Python floating point number to a C ‘double’. ‘D’ (*note complex: 189.) [Py_complex] Convert a Python complex number to a C *note Py_complex: 39cb. structure.  File: python.info, Node: Other objects, Next: API Functions, Prev: Numbers<2>, Up: Parsing arguments<3> 7.6.6.4 Other objects ..................... ‘O’ (object) [PyObject *] Store a Python object (without any conversion) in a C object pointer. The C program thus receives the actual object that was passed. The object’s reference count is not increased. The pointer stored is not ‘NULL’. ‘O!’ (object) [`typeobject', PyObject *] Store a Python object in a C object pointer. This is similar to ‘O’, but takes two C arguments: the first is the address of a Python type object, the second is the address of the C variable (of type *note PyObject*: 4ba.) into which the object pointer is stored. If the Python object does not have the required type, *note TypeError: 192. is raised. ‘O&’ (object) [`converter', `anything'] Convert a Python object to a C variable through a `converter' function. This takes two arguments: the first is a function, the second is the address of a C variable (of arbitrary type), converted to ‘void *’. The `converter' function in turn is called as follows: status = converter(object, address); where `object' is the Python object to be converted and `address' is the ‘void*’ argument that was passed to the *note PyArg_Parse*(): 39c6. function. The returned `status' should be ‘1’ for a successful conversion and ‘0’ if the conversion has failed. When the conversion fails, the `converter' function should raise an exception and leave the content of `address' unmodified. If the `converter' returns ‘Py_CLEANUP_SUPPORTED’, it may get called a second time if the argument parsing eventually fails, giving the converter a chance to release any memory that it had already allocated. In this second call, the `object' parameter will be ‘NULL’; `address' will have the same value as in the original call. Changed in version 3.1: ‘Py_CLEANUP_SUPPORTED’ was added. ‘p’ (*note bool: 183.) [int] Tests the value passed in for truth (a boolean `p'redicate) and converts the result to its equivalent C true/false integer value. Sets the int to ‘1’ if the expression was true and ‘0’ if it was false. This accepts any valid Python value. See *note Truth Value Testing: 128d. for more information about how Python tests values for truth. New in version 3.3. ‘(items)’ (*note tuple: 47e.) [`matching-items'] The object must be a Python sequence whose length is the number of format units in `items'. The C arguments must correspond to the individual format units in `items'. Format units for sequences may be nested. It is possible to pass “long” integers (integers whose value exceeds the platform’s ‘LONG_MAX’) however no proper range checking is done — the most significant bits are silently truncated when the receiving field is too small to receive the value (actually, the semantics are inherited from downcasts in C — your mileage may vary). A few other characters have a meaning in a format string. These may not occur inside nested parentheses. They are: ‘|’ Indicates that the remaining arguments in the Python argument list are optional. The C variables corresponding to optional arguments should be initialized to their default value — when an optional argument is not specified, *note PyArg_ParseTuple(): 26a. does not touch the contents of the corresponding C variable(s). ‘$’ *note PyArg_ParseTupleAndKeywords(): 5ca. only: Indicates that the remaining arguments in the Python argument list are keyword-only. Currently, all keyword-only arguments must also be optional arguments, so ‘|’ must always be specified before ‘$’ in the format string. New in version 3.3. ‘:’ The list of format units ends here; the string after the colon is used as the function name in error messages (the “associated value” of the exception that *note PyArg_ParseTuple(): 26a. raises). ‘;’ The list of format units ends here; the string after the semicolon is used as the error message `instead' of the default error message. ‘:’ and ‘;’ mutually exclude each other. Note that any Python object references which are provided to the caller are `borrowed' references; do not decrement their reference count! Additional arguments passed to these functions must be addresses of variables whose type is determined by the format string; these are used to store values from the input tuple. There are a few cases, as described in the list of format units above, where these parameters are used as input values; they should match what is specified for the corresponding format unit in that case. For the conversion to succeed, the `arg' object must match the format and the format must be exhausted. On success, the *note PyArg_Parse*(): 39c6. functions return true, otherwise they return false and raise an appropriate exception. When the *note PyArg_Parse*(): 39c6. functions fail due to conversion failure in one of the format units, the variables at the addresses corresponding to that and the following format units are left untouched.  File: python.info, Node: API Functions, Prev: Other objects, Up: Parsing arguments<3> 7.6.6.5 API Functions ..................... -- C Function: int PyArg_ParseTuple (PyObject *args, const char *format, ...) Parse the parameters of a function that takes only positional parameters into local variables. Returns true on success; on failure, it returns false and raises the appropriate exception. -- C Function: int PyArg_VaParse (PyObject *args, const char *format, va_list vargs) Identical to *note PyArg_ParseTuple(): 26a, except that it accepts a va_list rather than a variable number of arguments. -- C Function: int PyArg_ParseTupleAndKeywords (PyObject *args, PyObject *kw, const char *format, char *keywords[], ...) Parse the parameters of a function that takes both positional and keyword parameters into local variables. The `keywords' argument is a ‘NULL’-terminated array of keyword parameter names. Empty names denote *note positional-only parameters: 2a7. Returns true on success; on failure, it returns false and raises the appropriate exception. Changed in version 3.6: Added support for *note positional-only parameters: 2a7. -- C Function: int PyArg_VaParseTupleAndKeywords (PyObject *args, PyObject *kw, const char *format, char *keywords[], va_list vargs) Identical to *note PyArg_ParseTupleAndKeywords(): 5ca, except that it accepts a va_list rather than a variable number of arguments. -- C Function: int PyArg_ValidateKeywordArguments (PyObject *) Ensure that the keys in the keywords argument dictionary are strings. This is only needed if *note PyArg_ParseTupleAndKeywords(): 5ca. is not used, since the latter already does this check. New in version 3.2. -- C Function: int PyArg_Parse (PyObject *args, const char *format, ...) Function used to deconstruct the argument lists of “old-style” functions — these are functions which use the ‘METH_OLDARGS’ parameter parsing method, which has been removed in Python 3. This is not recommended for use in parameter parsing in new code, and most code in the standard interpreter has been modified to no longer use this for that purpose. It does remain a convenient way to decompose other tuples, however, and may continue to be used for that purpose. -- C Function: int PyArg_UnpackTuple (PyObject *args, const char *name, Py_ssize_t min, Py_ssize_t max, ...) A simpler form of parameter retrieval which does not use a format string to specify the types of the arguments. Functions which use this method to retrieve their parameters should be declared as *note METH_VARARGS: e48. in function or method tables. The tuple containing the actual parameters should be passed as `args'; it must actually be a tuple. The length of the tuple must be at least `min' and no more than `max'; `min' and `max' may be equal. Additional arguments must be passed to the function, each of which should be a pointer to a *note PyObject*: 4ba. variable; these will be filled in with the values from `args'; they will contain borrowed references. The variables which correspond to optional parameters not given by `args' will not be filled in; these should be initialized by the caller. This function returns true on success and false if `args' is not a tuple or contains the wrong number of elements; an exception will be set if there was a failure. This is an example of the use of this function, taken from the sources for the ‘_weakref’ helper module for weak references: static PyObject * weakref_ref(PyObject *self, PyObject *args) { PyObject *object; PyObject *callback = NULL; PyObject *result = NULL; if (PyArg_UnpackTuple(args, "ref", 1, 2, &object, &callback)) { result = PyWeakref_NewRef(object, callback); } return result; } The call to *note PyArg_UnpackTuple(): e46. in this example is entirely equivalent to this call to *note PyArg_ParseTuple(): 26a.: PyArg_ParseTuple(args, "O|O:ref", &object, &callback)  File: python.info, Node: Building values, Prev: Parsing arguments<3>, Up: Parsing arguments and building values 7.6.6.6 Building values ....................... -- C Function: PyObject* Py_BuildValue (const char *format, ...) `Return value: New reference.' Create a new value based on a format string similar to those accepted by the *note PyArg_Parse*(): 39c6. family of functions and a sequence of values. Returns the value or ‘NULL’ in the case of an error; an exception will be raised if ‘NULL’ is returned. *note Py_BuildValue(): 2ce. does not always build a tuple. It builds a tuple only if its format string contains two or more format units. If the format string is empty, it returns ‘None’; if it contains exactly one format unit, it returns whatever object is described by that format unit. To force it to return a tuple of size 0 or one, parenthesize the format string. When memory buffers are passed as parameters to supply data to build objects, as for the ‘s’ and ‘s#’ formats, the required data is copied. Buffers provided by the caller are never referenced by the objects created by *note Py_BuildValue(): 2ce. In other words, if your code invokes ‘malloc()’ and passes the allocated memory to *note Py_BuildValue(): 2ce, your code is responsible for calling ‘free()’ for that memory once *note Py_BuildValue(): 2ce. returns. In the following description, the quoted form is the format unit; the entry in (round) parentheses is the Python object type that the format unit will return; and the entry in [square] brackets is the type of the C value(s) to be passed. The characters space, tab, colon and comma are ignored in format strings (but not within format units such as ‘s#’). This can be used to make long format strings a tad more readable. ‘s’ (*note str: 330. or ‘None’) [const char *] Convert a null-terminated C string to a Python *note str: 330. object using ‘'utf-8'’ encoding. If the C string pointer is ‘NULL’, ‘None’ is used. ‘s#’ (*note str: 330. or ‘None’) [const char *, int or ‘Py_ssize_t’] Convert a C string and its length to a Python *note str: 330. object using ‘'utf-8'’ encoding. If the C string pointer is ‘NULL’, the length is ignored and ‘None’ is returned. ‘y’ (*note bytes: 331.) [const char *] This converts a C string to a Python *note bytes: 331. object. If the C string pointer is ‘NULL’, ‘None’ is returned. ‘y#’ (*note bytes: 331.) [const char *, int or ‘Py_ssize_t’] This converts a C string and its lengths to a Python object. If the C string pointer is ‘NULL’, ‘None’ is returned. ‘z’ (*note str: 330. or ‘None’) [const char *] Same as ‘s’. ‘z#’ (*note str: 330. or ‘None’) [const char *, int or ‘Py_ssize_t’] Same as ‘s#’. ‘u’ (*note str: 330.) [const wchar_t *] Convert a null-terminated ‘wchar_t’ buffer of Unicode (UTF-16 or UCS-4) data to a Python Unicode object. If the Unicode buffer pointer is ‘NULL’, ‘None’ is returned. ‘u#’ (*note str: 330.) [const wchar_t *, int or ‘Py_ssize_t’] Convert a Unicode (UTF-16 or UCS-4) data buffer and its length to a Python Unicode object. If the Unicode buffer pointer is ‘NULL’, the length is ignored and ‘None’ is returned. ‘U’ (*note str: 330. or ‘None’) [const char *] Same as ‘s’. ‘U#’ (*note str: 330. or ‘None’) [const char *, int or ‘Py_ssize_t’] Same as ‘s#’. ‘i’ (*note int: 184.) [int] Convert a plain C ‘int’ to a Python integer object. ‘b’ (*note int: 184.) [char] Convert a plain C ‘char’ to a Python integer object. ‘h’ (*note int: 184.) [short int] Convert a plain C ‘short int’ to a Python integer object. ‘l’ (*note int: 184.) [long int] Convert a C ‘long int’ to a Python integer object. ‘B’ (*note int: 184.) [unsigned char] Convert a C ‘unsigned char’ to a Python integer object. ‘H’ (*note int: 184.) [unsigned short int] Convert a C ‘unsigned short int’ to a Python integer object. ‘I’ (*note int: 184.) [unsigned int] Convert a C ‘unsigned int’ to a Python integer object. ‘k’ (*note int: 184.) [unsigned long] Convert a C ‘unsigned long’ to a Python integer object. ‘L’ (*note int: 184.) [long long] Convert a C ‘long long’ to a Python integer object. ‘K’ (*note int: 184.) [unsigned long long] Convert a C ‘unsigned long long’ to a Python integer object. ‘n’ (*note int: 184.) [Py_ssize_t] Convert a C ‘Py_ssize_t’ to a Python integer. ‘c’ (*note bytes: 331. of length 1) [char] Convert a C ‘int’ representing a byte to a Python *note bytes: 331. object of length 1. ‘C’ (*note str: 330. of length 1) [int] Convert a C ‘int’ representing a character to Python *note str: 330. object of length 1. ‘d’ (*note float: 187.) [double] Convert a C ‘double’ to a Python floating point number. ‘f’ (*note float: 187.) [float] Convert a C ‘float’ to a Python floating point number. ‘D’ (*note complex: 189.) [Py_complex *] Convert a C *note Py_complex: 39cb. structure to a Python complex number. ‘O’ (object) [PyObject *] Pass a Python object untouched (except for its reference count, which is incremented by one). If the object passed in is a ‘NULL’ pointer, it is assumed that this was caused because the call producing the argument found an error and set an exception. Therefore, *note Py_BuildValue(): 2ce. will return ‘NULL’ but won’t raise an exception. If no exception has been raised yet, *note SystemError: 5fb. is set. ‘S’ (object) [PyObject *] Same as ‘O’. ‘N’ (object) [PyObject *] Same as ‘O’, except it doesn’t increment the reference count on the object. Useful when the object is created by a call to an object constructor in the argument list. ‘O&’ (object) [`converter', `anything'] Convert `anything' to a Python object through a `converter' function. The function is called with `anything' (which should be compatible with ‘void*’) as its argument and should return a “new” Python object, or ‘NULL’ if an error occurred. ‘(items)’ (*note tuple: 47e.) [`matching-items'] Convert a sequence of C values to a Python tuple with the same number of items. ‘[items]’ (*note list: 262.) [`matching-items'] Convert a sequence of C values to a Python list with the same number of items. ‘{items}’ (*note dict: 1b8.) [`matching-items'] Convert a sequence of C values to a Python dictionary. Each pair of consecutive C values adds one item to the dictionary, serving as key and value, respectively. If there is an error in the format string, the *note SystemError: 5fb. exception is set and ‘NULL’ returned. -- C Function: PyObject* Py_VaBuildValue (const char *format, va_list vargs) `Return value: New reference.' Identical to *note Py_BuildValue(): 2ce, except that it accepts a va_list rather than a variable number of arguments.  File: python.info, Node: String conversion and formatting, Next: Reflection, Prev: Parsing arguments and building values, Up: Utilities<2> 7.6.7 String conversion and formatting -------------------------------------- Functions for number conversion and formatted string output. -- C Function: int PyOS_snprintf (char *str, size_t size, const char *format, ...) Output not more than `size' bytes to `str' according to the format string `format' and the extra arguments. See the Unix man page ‘snprintf(3)’. -- C Function: int PyOS_vsnprintf (char *str, size_t size, const char *format, va_list va) Output not more than `size' bytes to `str' according to the format string `format' and the variable argument list `va'. Unix man page ‘vsnprintf(3)’. *note PyOS_snprintf(): e49. and *note PyOS_vsnprintf(): e4a. wrap the Standard C library functions ‘snprintf()’ and ‘vsnprintf()’. Their purpose is to guarantee consistent behavior in corner cases, which the Standard C functions do not. The wrappers ensure that ‘str[size-1]’ is always ‘'\0'’ upon return. They never write more than `size' bytes (including the trailing ‘'\0'’) into str. Both functions require that ‘str != NULL’, ‘size > 0’ and ‘format != NULL’. If the platform doesn’t have ‘vsnprintf()’ and the buffer size needed to avoid truncation exceeds `size' by more than 512 bytes, Python aborts with a *note Py_FatalError(): 39a2. The return value (`rv') for these functions should be interpreted as follows: * When ‘0 <= rv < size’, the output conversion was successful and `rv' characters were written to `str' (excluding the trailing ‘'\0'’ byte at ‘str[rv]’). * When ‘rv >= size’, the output conversion was truncated and a buffer with ‘rv + 1’ bytes would have been needed to succeed. ‘str[size-1]’ is ‘'\0'’ in this case. * When ‘rv < 0’, “something bad happened.” ‘str[size-1]’ is ‘'\0'’ in this case too, but the rest of `str' is undefined. The exact cause of the error depends on the underlying platform. The following functions provide locale-independent string to number conversions. -- C Function: double PyOS_string_to_double (const char *s, char **endptr, PyObject *overflow_exception) Convert a string ‘s’ to a ‘double’, raising a Python exception on failure. The set of accepted strings corresponds to the set of strings accepted by Python’s *note float(): 187. constructor, except that ‘s’ must not have leading or trailing whitespace. The conversion is independent of the current locale. If ‘endptr’ is ‘NULL’, convert the whole string. Raise *note ValueError: 1fb. and return ‘-1.0’ if the string is not a valid representation of a floating-point number. If endptr is not ‘NULL’, convert as much of the string as possible and set ‘*endptr’ to point to the first unconverted character. If no initial segment of the string is the valid representation of a floating-point number, set ‘*endptr’ to point to the beginning of the string, raise ValueError, and return ‘-1.0’. If ‘s’ represents a value that is too large to store in a float (for example, ‘"1e500"’ is such a string on many platforms) then if ‘overflow_exception’ is ‘NULL’ return ‘Py_HUGE_VAL’ (with an appropriate sign) and don’t set any exception. Otherwise, ‘overflow_exception’ must point to a Python exception object; raise that exception and return ‘-1.0’. In both cases, set ‘*endptr’ to point to the first character after the converted value. If any other error occurs during the conversion (for example an out-of-memory error), set the appropriate Python exception and return ‘-1.0’. New in version 3.1. -- C Function: char* PyOS_double_to_string (double val, char format_code, int precision, int flags, int *ptype) Convert a ‘double’ `val' to a string using supplied `format_code', `precision', and `flags'. `format_code' must be one of ‘'e'’, ‘'E'’, ‘'f'’, ‘'F'’, ‘'g'’, ‘'G'’ or ‘'r'’. For ‘'r'’, the supplied `precision' must be 0 and is ignored. The ‘'r'’ format code specifies the standard *note repr(): 7cc. format. `flags' can be zero or more of the values ‘Py_DTSF_SIGN’, ‘Py_DTSF_ADD_DOT_0’, or ‘Py_DTSF_ALT’, or-ed together: * ‘Py_DTSF_SIGN’ means to always precede the returned string with a sign character, even if `val' is non-negative. * ‘Py_DTSF_ADD_DOT_0’ means to ensure that the returned string will not look like an integer. * ‘Py_DTSF_ALT’ means to apply “alternate” formatting rules. See the documentation for the *note PyOS_snprintf(): e49. ‘'#'’ specifier for details. If `ptype' is non-‘NULL’, then the value it points to will be set to one of ‘Py_DTST_FINITE’, ‘Py_DTST_INFINITE’, or ‘Py_DTST_NAN’, signifying that `val' is a finite number, an infinite number, or not a number, respectively. The return value is a pointer to `buffer' with the converted string or ‘NULL’ if the conversion failed. The caller is responsible for freeing the returned string by calling *note PyMem_Free(): da9. New in version 3.1. -- C Function: int PyOS_stricmp (const char *s1, const char *s2) Case insensitive comparison of strings. The function works almost identically to ‘strcmp()’ except that it ignores the case. -- C Function: int PyOS_strnicmp (const char *s1, const char *s2, Py_ssize_t size) Case insensitive comparison of strings. The function works almost identically to ‘strncmp()’ except that it ignores the case.  File: python.info, Node: Reflection, Next: Codec registry and support functions, Prev: String conversion and formatting, Up: Utilities<2> 7.6.8 Reflection ---------------- -- C Function: PyObject* PyEval_GetBuiltins () `Return value: Borrowed reference.' Return a dictionary of the builtins in the current execution frame, or the interpreter of the thread state if no frame is currently executing. -- C Function: PyObject* PyEval_GetLocals () `Return value: Borrowed reference.' Return a dictionary of the local variables in the current execution frame, or ‘NULL’ if no frame is currently executing. -- C Function: PyObject* PyEval_GetGlobals () `Return value: Borrowed reference.' Return a dictionary of the global variables in the current execution frame, or ‘NULL’ if no frame is currently executing. -- C Function: PyFrameObject* PyEval_GetFrame () `Return value: Borrowed reference.' Return the current thread state’s frame, which is ‘NULL’ if no frame is currently executing. -- C Function: int PyFrame_GetLineNumber (PyFrameObject *frame) Return the line number that `frame' is currently executing. -- C Function: const char* PyEval_GetFuncName (PyObject *func) Return the name of `func' if it is a function, class or instance object, else the name of `func's type. -- C Function: const char* PyEval_GetFuncDesc (PyObject *func) Return a description string, depending on the type of `func'. Return values include “()” for functions and methods, ” constructor”, ” instance”, and ” object”. Concatenated with the result of *note PyEval_GetFuncName(): 39e0, the result will be a description of `func'.  File: python.info, Node: Codec registry and support functions, Prev: Reflection, Up: Utilities<2> 7.6.9 Codec registry and support functions ------------------------------------------ -- C Function: int PyCodec_Register (PyObject *search_function) Register a new codec search function. As side effect, this tries to load the ‘encodings’ package, if not yet done, to make sure that it is always first in the list of search functions. -- C Function: int PyCodec_KnownEncoding (const char *encoding) Return ‘1’ or ‘0’ depending on whether there is a registered codec for the given `encoding'. This function always succeeds. -- C Function: PyObject* PyCodec_Encode (PyObject *object, const char *encoding, const char *errors) `Return value: New reference.' Generic codec based encoding API. `object' is passed through the encoder function found for the given `encoding' using the error handling method defined by `errors'. `errors' may be ‘NULL’ to use the default method defined for the codec. Raises a *note LookupError: 1308. if no encoder can be found. -- C Function: PyObject* PyCodec_Decode (PyObject *object, const char *encoding, const char *errors) `Return value: New reference.' Generic codec based decoding API. `object' is passed through the decoder function found for the given `encoding' using the error handling method defined by `errors'. `errors' may be ‘NULL’ to use the default method defined for the codec. Raises a *note LookupError: 1308. if no encoder can be found. * Menu: * Codec lookup API:: * Registry API for Unicode encoding error handlers::  File: python.info, Node: Codec lookup API, Next: Registry API for Unicode encoding error handlers, Up: Codec registry and support functions 7.6.9.1 Codec lookup API ........................ In the following functions, the `encoding' string is looked up converted to all lower-case characters, which makes encodings looked up through this mechanism effectively case-insensitive. If no codec is found, a *note KeyError: 2c7. is set and ‘NULL’ returned. -- C Function: PyObject* PyCodec_Encoder (const char *encoding) `Return value: New reference.' Get an encoder function for the given `encoding'. -- C Function: PyObject* PyCodec_Decoder (const char *encoding) `Return value: New reference.' Get a decoder function for the given `encoding'. -- C Function: PyObject* PyCodec_IncrementalEncoder (const char *encoding, const char *errors) `Return value: New reference.' Get an *note IncrementalEncoder: 14d4. object for the given `encoding'. -- C Function: PyObject* PyCodec_IncrementalDecoder (const char *encoding, const char *errors) `Return value: New reference.' Get an *note IncrementalDecoder: 14d5. object for the given `encoding'. -- C Function: PyObject* PyCodec_StreamReader (const char *encoding, PyObject *stream, const char *errors) `Return value: New reference.' Get a *note StreamReader: 14d9. factory function for the given `encoding'. -- C Function: PyObject* PyCodec_StreamWriter (const char *encoding, PyObject *stream, const char *errors) `Return value: New reference.' Get a *note StreamWriter: 14d8. factory function for the given `encoding'.  File: python.info, Node: Registry API for Unicode encoding error handlers, Prev: Codec lookup API, Up: Codec registry and support functions 7.6.9.2 Registry API for Unicode encoding error handlers ........................................................ -- C Function: int PyCodec_RegisterError (const char *name, PyObject *error) Register the error handling callback function `error' under the given `name'. This callback function will be called by a codec when it encounters unencodable characters/undecodable bytes and `name' is specified as the error parameter in the call to the encode/decode function. The callback gets a single argument, an instance of *note UnicodeEncodeError: 1fc, *note UnicodeDecodeError: 1fd. or *note UnicodeTranslateError: 13bd. that holds information about the problematic sequence of characters or bytes and their offset in the original string (see *note Unicode Exception Objects: 395e. for functions to extract this information). The callback must either raise the given exception, or return a two-item tuple containing the replacement for the problematic sequence, and an integer giving the offset in the original string at which encoding/decoding should be resumed. Return ‘0’ on success, ‘-1’ on error. -- C Function: PyObject* PyCodec_LookupError (const char *name) `Return value: New reference.' Lookup the error handling callback function registered under `name'. As a special case ‘NULL’ can be passed, in which case the error handling callback for “strict” will be returned. -- C Function: PyObject* PyCodec_StrictErrors (PyObject *exc) `Return value: Always NULL.' Raise `exc' as an exception. -- C Function: PyObject* PyCodec_IgnoreErrors (PyObject *exc) `Return value: New reference.' Ignore the unicode error, skipping the faulty input. -- C Function: PyObject* PyCodec_ReplaceErrors (PyObject *exc) `Return value: New reference.' Replace the unicode encode error with ‘?’ or ‘U+FFFD’. -- C Function: PyObject* PyCodec_XMLCharRefReplaceErrors (PyObject *exc) `Return value: New reference.' Replace the unicode encode error with XML character references. -- C Function: PyObject* PyCodec_BackslashReplaceErrors (PyObject *exc) `Return value: New reference.' Replace the unicode encode error with backslash escapes (‘\x’, ‘\u’ and ‘\U’). -- C Function: PyObject* PyCodec_NameReplaceErrors (PyObject *exc) `Return value: New reference.' Replace the unicode encode error with ‘\N{...}’ escapes. New in version 3.5.  File: python.info, Node: Abstract Objects Layer, Next: Concrete Objects Layer, Prev: Utilities<2>, Up: Python/C API Reference Manual 7.7 Abstract Objects Layer ========================== The functions in this chapter interact with Python objects regardless of their type, or with wide classes of object types (e.g. all numerical types, or all sequence types). When used on object types for which they do not apply, they will raise a Python exception. It is not possible to use these functions on objects that are not properly initialized, such as a list object that has been created by *note PyList_New(): 38f4, but whose items have not been set to some non-‘NULL’ value yet. * Menu: * Object Protocol:: * Number Protocol:: * Sequence Protocol:: * Mapping Protocol:: * Iterator Protocol:: * Buffer Protocol:: * Old Buffer Protocol::  File: python.info, Node: Object Protocol, Next: Number Protocol, Up: Abstract Objects Layer 7.7.1 Object Protocol --------------------- -- C Variable: PyObject* Py_NotImplemented The ‘NotImplemented’ singleton, used to signal that an operation is not implemented for the given type combination. -- C Macro: Py_RETURN_NOTIMPLEMENTED Properly handle returning *note Py_NotImplemented: 39fc. from within a C function (that is, increment the reference count of NotImplemented and return it). -- C Function: int PyObject_Print (PyObject *o, FILE *fp, int flags) Print an object `o', on file `fp'. Returns ‘-1’ on error. The flags argument is used to enable certain printing options. The only option currently supported is ‘Py_PRINT_RAW’; if given, the *note str(): 330. of the object is written instead of the *note repr(): 7cc. -- C Function: int PyObject_HasAttr (PyObject *o, PyObject *attr_name) Returns ‘1’ if `o' has the attribute `attr_name', and ‘0’ otherwise. This is equivalent to the Python expression ‘hasattr(o, attr_name)’. This function always succeeds. Note that exceptions which occur while calling *note __getattr__(): 31a. and *note __getattribute__(): 449. methods will get suppressed. To get error reporting use *note PyObject_GetAttr(): 3a00. instead. -- C Function: int PyObject_HasAttrString (PyObject *o, const char *attr_name) Returns ‘1’ if `o' has the attribute `attr_name', and ‘0’ otherwise. This is equivalent to the Python expression ‘hasattr(o, attr_name)’. This function always succeeds. Note that exceptions which occur while calling *note __getattr__(): 31a. and *note __getattribute__(): 449. methods and creating a temporary string object will get suppressed. To get error reporting use *note PyObject_GetAttrString(): 385b. instead. -- C Function: PyObject* PyObject_GetAttr (PyObject *o, PyObject *attr_name) `Return value: New reference.' Retrieve an attribute named `attr_name' from object `o'. Returns the attribute value on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o.attr_name’. -- C Function: PyObject* PyObject_GetAttrString (PyObject *o, const char *attr_name) `Return value: New reference.' Retrieve an attribute named `attr_name' from object `o'. Returns the attribute value on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o.attr_name’. -- C Function: PyObject* PyObject_GenericGetAttr (PyObject *o, PyObject *name) `Return value: New reference.' Generic attribute getter function that is meant to be put into a type object’s ‘tp_getattro’ slot. It looks for a descriptor in the dictionary of classes in the object’s MRO as well as an attribute in the object’s *note __dict__: 4fc. (if present). As outlined in *note Implementing Descriptors: 4e9, data descriptors take preference over instance attributes, while non-data descriptors don’t. Otherwise, an *note AttributeError: 39b. is raised. -- C Function: int PyObject_SetAttr (PyObject *o, PyObject *attr_name, PyObject *v) Set the value of the attribute named `attr_name', for object `o', to the value `v'. Raise an exception and return ‘-1’ on failure; return ‘0’ on success. This is the equivalent of the Python statement ‘o.attr_name = v’. If `v' is ‘NULL’, the attribute is deleted, however this feature is deprecated in favour of using *note PyObject_DelAttr(): 3a04. -- C Function: int PyObject_SetAttrString (PyObject *o, const char *attr_name, PyObject *v) Set the value of the attribute named `attr_name', for object `o', to the value `v'. Raise an exception and return ‘-1’ on failure; return ‘0’ on success. This is the equivalent of the Python statement ‘o.attr_name = v’. If `v' is ‘NULL’, the attribute is deleted, however this feature is deprecated in favour of using *note PyObject_DelAttrString(): 3a06. -- C Function: int PyObject_GenericSetAttr (PyObject *o, PyObject *name, PyObject *value) Generic attribute setter and deleter function that is meant to be put into a type object’s *note tp_setattro: 38a0. slot. It looks for a data descriptor in the dictionary of classes in the object’s MRO, and if found it takes preference over setting or deleting the attribute in the instance dictionary. Otherwise, the attribute is set or deleted in the object’s *note __dict__: 4fc. (if present). On success, ‘0’ is returned, otherwise an *note AttributeError: 39b. is raised and ‘-1’ is returned. -- C Function: int PyObject_DelAttr (PyObject *o, PyObject *attr_name) Delete attribute named `attr_name', for object `o'. Returns ‘-1’ on failure. This is the equivalent of the Python statement ‘del o.attr_name’. -- C Function: int PyObject_DelAttrString (PyObject *o, const char *attr_name) Delete attribute named `attr_name', for object `o'. Returns ‘-1’ on failure. This is the equivalent of the Python statement ‘del o.attr_name’. -- C Function: PyObject* PyObject_GenericGetDict (PyObject *o, void *context) `Return value: New reference.' A generic implementation for the getter of a ‘__dict__’ descriptor. It creates the dictionary if necessary. New in version 3.3. -- C Function: int PyObject_GenericSetDict (PyObject *o, PyObject *value, void *context) A generic implementation for the setter of a ‘__dict__’ descriptor. This implementation does not allow the dictionary to be deleted. New in version 3.3. -- C Function: PyObject* PyObject_RichCompare (PyObject *o1, PyObject *o2, int opid) `Return value: New reference.' Compare the values of `o1' and `o2' using the operation specified by `opid', which must be one of ‘Py_LT’, ‘Py_LE’, ‘Py_EQ’, ‘Py_NE’, ‘Py_GT’, or ‘Py_GE’, corresponding to ‘<’, ‘<=’, ‘==’, ‘!=’, ‘>’, or ‘>=’ respectively. This is the equivalent of the Python expression ‘o1 op o2’, where ‘op’ is the operator corresponding to `opid'. Returns the value of the comparison on success, or ‘NULL’ on failure. -- C Function: int PyObject_RichCompareBool (PyObject *o1, PyObject *o2, int opid) Compare the values of `o1' and `o2' using the operation specified by `opid', which must be one of ‘Py_LT’, ‘Py_LE’, ‘Py_EQ’, ‘Py_NE’, ‘Py_GT’, or ‘Py_GE’, corresponding to ‘<’, ‘<=’, ‘==’, ‘!=’, ‘>’, or ‘>=’ respectively. Returns ‘-1’ on error, ‘0’ if the result is false, ‘1’ otherwise. This is the equivalent of the Python expression ‘o1 op o2’, where ‘op’ is the operator corresponding to `opid'. Note: If `o1' and `o2' are the same object, *note PyObject_RichCompareBool(): 38a7. will always return ‘1’ for ‘Py_EQ’ and ‘0’ for ‘Py_NE’. -- C Function: PyObject* PyObject_Repr (PyObject *o) `Return value: New reference.' Compute a string representation of object `o'. Returns the string representation on success, ‘NULL’ on failure. This is the equivalent of the Python expression ‘repr(o)’. Called by the *note repr(): 7cc. built-in function. Changed in version 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception. -- C Function: PyObject* PyObject_ASCII (PyObject *o) `Return value: New reference.' As *note PyObject_Repr(): 968, compute a string representation of object `o', but escape the non-ASCII characters in the string returned by *note PyObject_Repr(): 968. with ‘\x’, ‘\u’ or ‘\U’ escapes. This generates a string similar to that returned by *note PyObject_Repr(): 968. in Python 2. Called by the *note ascii(): d4c. built-in function. -- C Function: PyObject* PyObject_Str (PyObject *o) `Return value: New reference.' Compute a string representation of object `o'. Returns the string representation on success, ‘NULL’ on failure. This is the equivalent of the Python expression ‘str(o)’. Called by the *note str(): 330. built-in function and, therefore, by the *note print(): 886. function. Changed in version 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception. -- C Function: PyObject* PyObject_Bytes (PyObject *o) `Return value: New reference.' Compute a bytes representation of object `o'. ‘NULL’ is returned on failure and a bytes object on success. This is equivalent to the Python expression ‘bytes(o)’, when `o' is not an integer. Unlike ‘bytes(o)’, a TypeError is raised when `o' is an integer instead of a zero-initialized bytes object. -- C Function: int PyObject_IsSubclass (PyObject *derived, PyObject *cls) Return ‘1’ if the class `derived' is identical to or derived from the class `cls', otherwise return ‘0’. In case of an error, return ‘-1’. If `cls' is a tuple, the check will be done against every entry in `cls'. The result will be ‘1’ when at least one of the checks returns ‘1’, otherwise it will be ‘0’. If `cls' has a *note __subclasscheck__(): 10f3. method, it will be called to determine the subclass status as described in PEP 3119(1). Otherwise, `derived' is a subclass of `cls' if it is a direct or indirect subclass, i.e. contained in ‘cls.__mro__’. Normally only class objects, i.e. instances of *note type: 608. or a derived class, are considered classes. However, objects can override this by having a ‘__bases__’ attribute (which must be a tuple of base classes). -- C Function: int PyObject_IsInstance (PyObject *inst, PyObject *cls) Return ‘1’ if `inst' is an instance of the class `cls' or a subclass of `cls', or ‘0’ if not. On error, returns ‘-1’ and sets an exception. If `cls' is a tuple, the check will be done against every entry in `cls'. The result will be ‘1’ when at least one of the checks returns ‘1’, otherwise it will be ‘0’. If `cls' has a *note __instancecheck__(): 10f2. method, it will be called to determine the subclass status as described in PEP 3119(2). Otherwise, `inst' is an instance of `cls' if its class is a subclass of `cls'. An instance `inst' can override what is considered its class by having a ‘__class__’ attribute. An object `cls' can override if it is considered a class, and what its base classes are, by having a ‘__bases__’ attribute (which must be a tuple of base classes). -- C Function: int PyCallable_Check (PyObject *o) Determine if the object `o' is callable. Return ‘1’ if the object is callable and ‘0’ otherwise. This function always succeeds. -- C Function: PyObject* PyObject_Call (PyObject *callable, PyObject *args, PyObject *kwargs) `Return value: New reference.' Call a callable Python object `callable', with arguments given by the tuple `args', and named arguments given by the dictionary `kwargs'. `args' must not be ‘NULL’, use an empty tuple if no arguments are needed. If no named arguments are needed, `kwargs' can be ‘NULL’. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This is the equivalent of the Python expression: ‘callable(*args, **kwargs)’. -- C Function: PyObject* PyObject_CallObject (PyObject *callable, PyObject *args) `Return value: New reference.' Call a callable Python object `callable', with arguments given by the tuple `args'. If no arguments are needed, then `args' can be ‘NULL’. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This is the equivalent of the Python expression: ‘callable(*args)’. -- C Function: PyObject* PyObject_CallFunction (PyObject *callable, const char *format, ...) `Return value: New reference.' Call a callable Python object `callable', with a variable number of C arguments. The C arguments are described using a *note Py_BuildValue(): 2ce. style format string. The format can be ‘NULL’, indicating that no arguments are provided. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This is the equivalent of the Python expression: ‘callable(*args)’. Note that if you only pass *note PyObject *: 4ba. args, *note PyObject_CallFunctionObjArgs(): 3a0d. is a faster alternative. Changed in version 3.4: The type of `format' was changed from ‘char *’. -- C Function: PyObject* PyObject_CallMethod (PyObject *obj, const char *name, const char *format, ...) `Return value: New reference.' Call the method named `name' of object `obj' with a variable number of C arguments. The C arguments are described by a *note Py_BuildValue(): 2ce. format string that should produce a tuple. The format can be ‘NULL’, indicating that no arguments are provided. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This is the equivalent of the Python expression: ‘obj.name(arg1, arg2, ...)’. Note that if you only pass *note PyObject *: 4ba. args, *note PyObject_CallMethodObjArgs(): 3a0f. is a faster alternative. Changed in version 3.4: The types of `name' and `format' were changed from ‘char *’. -- C Function: PyObject* PyObject_CallFunctionObjArgs (PyObject *callable, ...) `Return value: New reference.' Call a callable Python object `callable', with a variable number of *note PyObject*: 4ba. arguments. The arguments are provided as a variable number of parameters followed by ‘NULL’. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This is the equivalent of the Python expression: ‘callable(arg1, arg2, ...)’. -- C Function: PyObject* PyObject_CallMethodObjArgs (PyObject *obj, PyObject *name, ...) `Return value: New reference.' Calls a method of the Python object `obj', where the name of the method is given as a Python string object in `name'. It is called with a variable number of *note PyObject*: 4ba. arguments. The arguments are provided as a variable number of parameters followed by ‘NULL’. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. -- C Function: PyObject* _PyObject_Vectorcall (PyObject *callable, PyObject *const *args, size_t nargsf, PyObject *kwnames) Call a callable Python object `callable', using *note vectorcall: 3a11. if possible. `args' is a C array with the positional arguments. `nargsf' is the number of positional arguments plus optionally the flag ‘PY_VECTORCALL_ARGUMENTS_OFFSET’ (see below). To get actual number of arguments, use *note PyVectorcall_NARGS(nargsf): 3a12. `kwnames' can be either ‘NULL’ (no keyword arguments) or a tuple of keyword names. In the latter case, the values of the keyword arguments are stored in `args' after the positional arguments. The number of keyword arguments does not influence `nargsf'. `kwnames' must contain only objects of type ‘str’ (not a subclass), and all keys must be unique. Return the result of the call on success, or raise an exception and return ‘NULL’ on failure. This uses the vectorcall protocol if the callable supports it; otherwise, the arguments are converted to use *note tp_call: 38ad. Note: This function is provisional and expected to become public in Python 3.9, with a different name and, possibly, changed semantics. If you use the function, plan for updating your code for Python 3.9. New in version 3.8. -- C Macro: PY_VECTORCALL_ARGUMENTS_OFFSET If set in a vectorcall `nargsf' argument, the callee is allowed to temporarily change ‘args[-1]’. In other words, `args' points to argument 1 (not 0) in the allocated vector. The callee must restore the value of ‘args[-1]’ before returning. Whenever they can do so cheaply (without additional allocation), callers are encouraged to use ‘PY_VECTORCALL_ARGUMENTS_OFFSET’. Doing so will allow callables such as bound methods to make their onward calls (which include a prepended `self' argument) cheaply. New in version 3.8. -- C Function: Py_ssize_t PyVectorcall_NARGS (size_t nargsf) Given a vectorcall `nargsf' argument, return the actual number of arguments. Currently equivalent to ‘nargsf & ~PY_VECTORCALL_ARGUMENTS_OFFSET’. New in version 3.8. -- C Function: PyObject* _PyObject_FastCallDict (PyObject *callable, PyObject *const *args, size_t nargsf, PyObject *kwdict) Same as *note _PyObject_Vectorcall(): 3a10. except that the keyword arguments are passed as a dictionary in `kwdict'. This may be ‘NULL’ if there are no keyword arguments. For callables supporting *note vectorcall: 3a11, the arguments are internally converted to the vectorcall convention. Therefore, this function adds some overhead compared to *note _PyObject_Vectorcall(): 3a10. It should only be used if the caller already has a dictionary ready to use. Note: This function is provisional and expected to become public in Python 3.9, with a different name and, possibly, changed semantics. If you use the function, plan for updating your code for Python 3.9. New in version 3.8. -- C Function: Py_hash_t PyObject_Hash (PyObject *o) Compute and return the hash value of an object `o'. On failure, return ‘-1’. This is the equivalent of the Python expression ‘hash(o)’. Changed in version 3.2: The return type is now Py_hash_t. This is a signed integer the same size as Py_ssize_t. -- C Function: Py_hash_t PyObject_HashNotImplemented (PyObject *o) Set a *note TypeError: 192. indicating that ‘type(o)’ is not hashable and return ‘-1’. This function receives special treatment when stored in a ‘tp_hash’ slot, allowing a type to explicitly indicate to the interpreter that it is not hashable. -- C Function: int PyObject_IsTrue (PyObject *o) Returns ‘1’ if the object `o' is considered to be true, and ‘0’ otherwise. This is equivalent to the Python expression ‘not not o’. On failure, return ‘-1’. -- C Function: int PyObject_Not (PyObject *o) Returns ‘0’ if the object `o' is considered to be true, and ‘1’ otherwise. This is equivalent to the Python expression ‘not o’. On failure, return ‘-1’. -- C Function: PyObject* PyObject_Type (PyObject *o) `Return value: New reference.' When `o' is non-‘NULL’, returns a type object corresponding to the object type of object `o'. On failure, raises *note SystemError: 5fb. and returns ‘NULL’. This is equivalent to the Python expression ‘type(o)’. This function increments the reference count of the return value. There’s really no reason to use this function instead of the common expression ‘o->ob_type’, which returns a pointer of type *note PyTypeObject*: 2d6, except when the incremented reference count is needed. -- C Function: int PyObject_TypeCheck (PyObject *o, PyTypeObject *type) Return true if the object `o' is of type `type' or a subtype of `type'. Both parameters must be non-‘NULL’. -- C Function: Py_ssize_t PyObject_Size (PyObject *o) -- C Function: Py_ssize_t PyObject_Length (PyObject *o) Return the length of object `o'. If the object `o' provides either the sequence and mapping protocols, the sequence length is returned. On error, ‘-1’ is returned. This is the equivalent to the Python expression ‘len(o)’. -- C Function: Py_ssize_t PyObject_LengthHint (PyObject *o, Py_ssize_t default) Return an estimated length for the object `o'. First try to return its actual length, then an estimate using *note __length_hint__(): 80c, and finally return the default value. On error return ‘-1’. This is the equivalent to the Python expression ‘operator.length_hint(o, default)’. New in version 3.4. -- C Function: PyObject* PyObject_GetItem (PyObject *o, PyObject *key) `Return value: New reference.' Return element of `o' corresponding to the object `key' or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o[key]’. -- C Function: int PyObject_SetItem (PyObject *o, PyObject *key, PyObject *v) Map the object `key' to the value `v'. Raise an exception and return ‘-1’ on failure; return ‘0’ on success. This is the equivalent of the Python statement ‘o[key] = v’. This function `does not' steal a reference to `v'. -- C Function: int PyObject_DelItem (PyObject *o, PyObject *key) Remove the mapping for the object `key' from the object `o'. Return ‘-1’ on failure. This is equivalent to the Python statement ‘del o[key]’. -- C Function: PyObject* PyObject_Dir (PyObject *o) `Return value: New reference.' This is equivalent to the Python expression ‘dir(o)’, returning a (possibly empty) list of strings appropriate for the object argument, or ‘NULL’ if there was an error. If the argument is ‘NULL’, this is like the Python ‘dir()’, returning the names of the current locals; in this case, if no execution frame is active then ‘NULL’ is returned but *note PyErr_Occurred(): 383f. will return false. -- C Function: PyObject* PyObject_GetIter (PyObject *o) `Return value: New reference.' This is equivalent to the Python expression ‘iter(o)’. It returns a new iterator for the object argument, or the object itself if the object is already an iterator. Raises *note TypeError: 192. and returns ‘NULL’ if the object cannot be iterated. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3119 (2) https://www.python.org/dev/peps/pep-3119  File: python.info, Node: Number Protocol, Next: Sequence Protocol, Prev: Object Protocol, Up: Abstract Objects Layer 7.7.2 Number Protocol --------------------- -- C Function: int PyNumber_Check (PyObject *o) Returns ‘1’ if the object `o' provides numeric protocols, and false otherwise. This function always succeeds. Changed in version 3.8: Returns ‘1’ if `o' is an index integer. -- C Function: PyObject* PyNumber_Add (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of adding `o1' and `o2', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 + o2’. -- C Function: PyObject* PyNumber_Subtract (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of subtracting `o2' from `o1', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 - o2’. -- C Function: PyObject* PyNumber_Multiply (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of multiplying `o1' and `o2', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 * o2’. -- C Function: PyObject* PyNumber_MatrixMultiply (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of matrix multiplication on `o1' and `o2', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 @ o2’. New in version 3.5. -- C Function: PyObject* PyNumber_FloorDivide (PyObject *o1, PyObject *o2) `Return value: New reference.' Return the floor of `o1' divided by `o2', or ‘NULL’ on failure. This is equivalent to the “classic” division of integers. -- C Function: PyObject* PyNumber_TrueDivide (PyObject *o1, PyObject *o2) `Return value: New reference.' Return a reasonable approximation for the mathematical value of `o1' divided by `o2', or ‘NULL’ on failure. The return value is “approximate” because binary floating point numbers are approximate; it is not possible to represent all real numbers in base two. This function can return a floating point value when passed two integers. -- C Function: PyObject* PyNumber_Remainder (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the remainder of dividing `o1' by `o2', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 % o2’. -- C Function: PyObject* PyNumber_Divmod (PyObject *o1, PyObject *o2) `Return value: New reference.' See the built-in function *note divmod(): 152. Returns ‘NULL’ on failure. This is the equivalent of the Python expression ‘divmod(o1, o2)’. -- C Function: PyObject* PyNumber_Power (PyObject *o1, PyObject *o2, PyObject *o3) `Return value: New reference.' See the built-in function *note pow(): 19a. Returns ‘NULL’ on failure. This is the equivalent of the Python expression ‘pow(o1, o2, o3)’, where `o3' is optional. If `o3' is to be ignored, pass *note Py_None: 3844. in its place (passing ‘NULL’ for `o3' would cause an illegal memory access). -- C Function: PyObject* PyNumber_Negative (PyObject *o) `Return value: New reference.' Returns the negation of `o' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘-o’. -- C Function: PyObject* PyNumber_Positive (PyObject *o) `Return value: New reference.' Returns `o' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘+o’. -- C Function: PyObject* PyNumber_Absolute (PyObject *o) `Return value: New reference.' Returns the absolute value of `o', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘abs(o)’. -- C Function: PyObject* PyNumber_Invert (PyObject *o) `Return value: New reference.' Returns the bitwise negation of `o' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘~o’. -- C Function: PyObject* PyNumber_Lshift (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of left shifting `o1' by `o2' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 << o2’. -- C Function: PyObject* PyNumber_Rshift (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of right shifting `o1' by `o2' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 >> o2’. -- C Function: PyObject* PyNumber_And (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise and” of `o1' and `o2' on success and ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 & o2’. -- C Function: PyObject* PyNumber_Xor (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise exclusive or” of `o1' by `o2' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 ^ o2’. -- C Function: PyObject* PyNumber_Or (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise or” of `o1' and `o2' on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 | o2’. -- C Function: PyObject* PyNumber_InPlaceAdd (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of adding `o1' and `o2', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 += o2’. -- C Function: PyObject* PyNumber_InPlaceSubtract (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of subtracting `o2' from `o1', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 -= o2’. -- C Function: PyObject* PyNumber_InPlaceMultiply (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of multiplying `o1' and `o2', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 *= o2’. -- C Function: PyObject* PyNumber_InPlaceMatrixMultiply (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of matrix multiplication on `o1' and `o2', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 @= o2’. New in version 3.5. -- C Function: PyObject* PyNumber_InPlaceFloorDivide (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the mathematical floor of dividing `o1' by `o2', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 //= o2’. -- C Function: PyObject* PyNumber_InPlaceTrueDivide (PyObject *o1, PyObject *o2) `Return value: New reference.' Return a reasonable approximation for the mathematical value of `o1' divided by `o2', or ‘NULL’ on failure. The return value is “approximate” because binary floating point numbers are approximate; it is not possible to represent all real numbers in base two. This function can return a floating point value when passed two integers. The operation is done `in-place' when `o1' supports it. -- C Function: PyObject* PyNumber_InPlaceRemainder (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the remainder of dividing `o1' by `o2', or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 %= o2’. -- C Function: PyObject* PyNumber_InPlacePower (PyObject *o1, PyObject *o2, PyObject *o3) `Return value: New reference.' See the built-in function *note pow(): 19a. Returns ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 **= o2’ when o3 is *note Py_None: 3844, or an in-place variant of ‘pow(o1, o2, o3)’ otherwise. If `o3' is to be ignored, pass *note Py_None: 3844. in its place (passing ‘NULL’ for `o3' would cause an illegal memory access). -- C Function: PyObject* PyNumber_InPlaceLshift (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of left shifting `o1' by `o2' on success, or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 <<= o2’. -- C Function: PyObject* PyNumber_InPlaceRshift (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the result of right shifting `o1' by `o2' on success, or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 >>= o2’. -- C Function: PyObject* PyNumber_InPlaceAnd (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise and” of `o1' and `o2' on success and ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 &= o2’. -- C Function: PyObject* PyNumber_InPlaceXor (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise exclusive or” of `o1' by `o2' on success, or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 ^= o2’. -- C Function: PyObject* PyNumber_InPlaceOr (PyObject *o1, PyObject *o2) `Return value: New reference.' Returns the “bitwise or” of `o1' and `o2' on success, or ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python statement ‘o1 |= o2’. -- C Function: PyObject* PyNumber_Long (PyObject *o) `Return value: New reference.' Returns the `o' converted to an integer object on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘int(o)’. -- C Function: PyObject* PyNumber_Float (PyObject *o) `Return value: New reference.' Returns the `o' converted to a float object on success, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘float(o)’. -- C Function: PyObject* PyNumber_Index (PyObject *o) `Return value: New reference.' Returns the `o' converted to a Python int on success or ‘NULL’ with a *note TypeError: 192. exception raised on failure. -- C Function: PyObject* PyNumber_ToBase (PyObject *n, int base) `Return value: New reference.' Returns the integer `n' converted to base `base' as a string. The `base' argument must be one of 2, 8, 10, or 16. For base 2, 8, or 16, the returned string is prefixed with a base marker of ‘'0b'’, ‘'0o'’, or ‘'0x'’, respectively. If `n' is not a Python int, it is converted with *note PyNumber_Index(): 3a3e. first. -- C Function: Py_ssize_t PyNumber_AsSsize_t (PyObject *o, PyObject *exc) Returns `o' converted to a Py_ssize_t value if `o' can be interpreted as an integer. If the call fails, an exception is raised and ‘-1’ is returned. If `o' can be converted to a Python int but the attempt to convert to a Py_ssize_t value would raise an *note OverflowError: 960, then the `exc' argument is the type of exception that will be raised (usually *note IndexError: e75. or *note OverflowError: 960.). If `exc' is ‘NULL’, then the exception is cleared and the value is clipped to ‘PY_SSIZE_T_MIN’ for a negative integer or ‘PY_SSIZE_T_MAX’ for a positive integer. -- C Function: int PyIndex_Check (PyObject *o) Returns ‘1’ if `o' is an index integer (has the nb_index slot of the tp_as_number structure filled in), and ‘0’ otherwise. This function always succeeds.  File: python.info, Node: Sequence Protocol, Next: Mapping Protocol, Prev: Number Protocol, Up: Abstract Objects Layer 7.7.3 Sequence Protocol ----------------------- -- C Function: int PySequence_Check (PyObject *o) Return ‘1’ if the object provides sequence protocol, and ‘0’ otherwise. Note that it returns ‘1’ for Python classes with a *note __getitem__(): 27c. method unless they are *note dict: 1b8. subclasses since in general case it is impossible to determine what the type of keys it supports. This function always succeeds. -- C Function: Py_ssize_t PySequence_Size (PyObject *o) -- C Function: Py_ssize_t PySequence_Length (PyObject *o) Returns the number of objects in sequence `o' on success, and ‘-1’ on failure. This is equivalent to the Python expression ‘len(o)’. -- C Function: PyObject* PySequence_Concat (PyObject *o1, PyObject *o2) `Return value: New reference.' Return the concatenation of `o1' and `o2' on success, and ‘NULL’ on failure. This is the equivalent of the Python expression ‘o1 + o2’. -- C Function: PyObject* PySequence_Repeat (PyObject *o, Py_ssize_t count) `Return value: New reference.' Return the result of repeating sequence object `o' `count' times, or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o * count’. -- C Function: PyObject* PySequence_InPlaceConcat (PyObject *o1, PyObject *o2) `Return value: New reference.' Return the concatenation of `o1' and `o2' on success, and ‘NULL’ on failure. The operation is done `in-place' when `o1' supports it. This is the equivalent of the Python expression ‘o1 += o2’. -- C Function: PyObject* PySequence_InPlaceRepeat (PyObject *o, Py_ssize_t count) `Return value: New reference.' Return the result of repeating sequence object `o' `count' times, or ‘NULL’ on failure. The operation is done `in-place' when `o' supports it. This is the equivalent of the Python expression ‘o *= count’. -- C Function: PyObject* PySequence_GetItem (PyObject *o, Py_ssize_t i) `Return value: New reference.' Return the `i'th element of `o', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o[i]’. -- C Function: PyObject* PySequence_GetSlice (PyObject *o, Py_ssize_t i1, Py_ssize_t i2) `Return value: New reference.' Return the slice of sequence object `o' between `i1' and `i2', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o[i1:i2]’. -- C Function: int PySequence_SetItem (PyObject *o, Py_ssize_t i, PyObject *v) Assign object `v' to the `i'th element of `o'. Raise an exception and return ‘-1’ on failure; return ‘0’ on success. This is the equivalent of the Python statement ‘o[i] = v’. This function `does not' steal a reference to `v'. If `v' is ‘NULL’, the element is deleted, however this feature is deprecated in favour of using *note PySequence_DelItem(): 3a4d. -- C Function: int PySequence_DelItem (PyObject *o, Py_ssize_t i) Delete the `i'th element of object `o'. Returns ‘-1’ on failure. This is the equivalent of the Python statement ‘del o[i]’. -- C Function: int PySequence_SetSlice (PyObject *o, Py_ssize_t i1, Py_ssize_t i2, PyObject *v) Assign the sequence object `v' to the slice in sequence object `o' from `i1' to `i2'. This is the equivalent of the Python statement ‘o[i1:i2] = v’. -- C Function: int PySequence_DelSlice (PyObject *o, Py_ssize_t i1, Py_ssize_t i2) Delete the slice in sequence object `o' from `i1' to `i2'. Returns ‘-1’ on failure. This is the equivalent of the Python statement ‘del o[i1:i2]’. -- C Function: Py_ssize_t PySequence_Count (PyObject *o, PyObject *value) Return the number of occurrences of `value' in `o', that is, return the number of keys for which ‘o[key] == value’. On failure, return ‘-1’. This is equivalent to the Python expression ‘o.count(value)’. -- C Function: int PySequence_Contains (PyObject *o, PyObject *value) Determine if `o' contains `value'. If an item in `o' is equal to `value', return ‘1’, otherwise return ‘0’. On error, return ‘-1’. This is equivalent to the Python expression ‘value in o’. -- C Function: Py_ssize_t PySequence_Index (PyObject *o, PyObject *value) Return the first index `i' for which ‘o[i] == value’. On error, return ‘-1’. This is equivalent to the Python expression ‘o.index(value)’. -- C Function: PyObject* PySequence_List (PyObject *o) `Return value: New reference.' Return a list object with the same contents as the sequence or iterable `o', or ‘NULL’ on failure. The returned list is guaranteed to be new. This is equivalent to the Python expression ‘list(o)’. -- C Function: PyObject* PySequence_Tuple (PyObject *o) `Return value: New reference.' Return a tuple object with the same contents as the sequence or iterable `o', or ‘NULL’ on failure. If `o' is a tuple, a new reference will be returned, otherwise a tuple will be constructed with the appropriate contents. This is equivalent to the Python expression ‘tuple(o)’. -- C Function: PyObject* PySequence_Fast (PyObject *o, const char *m) `Return value: New reference.' Return the sequence or iterable `o' as an object usable by the other ‘PySequence_Fast*’ family of functions. If the object is not a sequence or iterable, raises *note TypeError: 192. with `m' as the message text. Returns ‘NULL’ on failure. The ‘PySequence_Fast*’ functions are thus named because they assume `o' is a *note PyTupleObject: 399f. or a *note PyListObject: 3a56. and access the data fields of `o' directly. As a CPython implementation detail, if `o' is already a sequence or list, it will be returned. -- C Function: Py_ssize_t PySequence_Fast_GET_SIZE (PyObject *o) Returns the length of `o', assuming that `o' was returned by *note PySequence_Fast(): 3a55. and that `o' is not ‘NULL’. The size can also be gotten by calling *note PySequence_Size(): 3a46. on `o', but *note PySequence_Fast_GET_SIZE(): 3a57. is faster because it can assume `o' is a list or tuple. -- C Function: PyObject* PySequence_Fast_GET_ITEM (PyObject *o, Py_ssize_t i) `Return value: Borrowed reference.' Return the `i'th element of `o', assuming that `o' was returned by *note PySequence_Fast(): 3a55, `o' is not ‘NULL’, and that `i' is within bounds. -- C Function: PyObject** PySequence_Fast_ITEMS (PyObject *o) Return the underlying array of PyObject pointers. Assumes that `o' was returned by *note PySequence_Fast(): 3a55. and `o' is not ‘NULL’. Note, if a list gets resized, the reallocation may relocate the items array. So, only use the underlying array pointer in contexts where the sequence cannot change. -- C Function: PyObject* PySequence_ITEM (PyObject *o, Py_ssize_t i) `Return value: New reference.' Return the `i'th element of `o' or ‘NULL’ on failure. Faster form of *note PySequence_GetItem(): 38f6. but without checking that *note PySequence_Check(): 3a45. on `o' is true and without adjustment for negative indices.  File: python.info, Node: Mapping Protocol, Next: Iterator Protocol, Prev: Sequence Protocol, Up: Abstract Objects Layer 7.7.4 Mapping Protocol ---------------------- See also *note PyObject_GetItem(): 38f5, *note PyObject_SetItem(): 38f3. and *note PyObject_DelItem(): 3a1b. -- C Function: int PyMapping_Check (PyObject *o) Return ‘1’ if the object provides mapping protocol or supports slicing, and ‘0’ otherwise. Note that it returns ‘1’ for Python classes with a *note __getitem__(): 27c. method since in general case it is impossible to determine what type of keys it supports. This function always succeeds. -- C Function: Py_ssize_t PyMapping_Size (PyObject *o) -- C Function: Py_ssize_t PyMapping_Length (PyObject *o) Returns the number of keys in object `o' on success, and ‘-1’ on failure. This is equivalent to the Python expression ‘len(o)’. -- C Function: PyObject* PyMapping_GetItemString (PyObject *o, const char *key) `Return value: New reference.' Return element of `o' corresponding to the string `key' or ‘NULL’ on failure. This is the equivalent of the Python expression ‘o[key]’. See also *note PyObject_GetItem(): 38f5. -- C Function: int PyMapping_SetItemString (PyObject *o, const char *key, PyObject *v) Map the string `key' to the value `v' in object `o'. Returns ‘-1’ on failure. This is the equivalent of the Python statement ‘o[key] = v’. See also *note PyObject_SetItem(): 38f3. This function `does not' steal a reference to `v'. -- C Function: int PyMapping_DelItem (PyObject *o, PyObject *key) Remove the mapping for the object `key' from the object `o'. Return ‘-1’ on failure. This is equivalent to the Python statement ‘del o[key]’. This is an alias of *note PyObject_DelItem(): 3a1b. -- C Function: int PyMapping_DelItemString (PyObject *o, const char *key) Remove the mapping for the string `key' from the object `o'. Return ‘-1’ on failure. This is equivalent to the Python statement ‘del o[key]’. -- C Function: int PyMapping_HasKey (PyObject *o, PyObject *key) Return ‘1’ if the mapping object has the key `key' and ‘0’ otherwise. This is equivalent to the Python expression ‘key in o’. This function always succeeds. Note that exceptions which occur while calling the *note __getitem__(): 27c. method will get suppressed. To get error reporting use *note PyObject_GetItem(): 38f5. instead. -- C Function: int PyMapping_HasKeyString (PyObject *o, const char *key) Return ‘1’ if the mapping object has the key `key' and ‘0’ otherwise. This is equivalent to the Python expression ‘key in o’. This function always succeeds. Note that exceptions which occur while calling the *note __getitem__(): 27c. method and creating a temporary string object will get suppressed. To get error reporting use *note PyMapping_GetItemString(): 3a61. instead. -- C Function: PyObject* PyMapping_Keys (PyObject *o) `Return value: New reference.' On success, return a list of the keys in object `o'. On failure, return ‘NULL’. Changed in version 3.7: Previously, the function returned a list or a tuple. -- C Function: PyObject* PyMapping_Values (PyObject *o) `Return value: New reference.' On success, return a list of the values in object `o'. On failure, return ‘NULL’. Changed in version 3.7: Previously, the function returned a list or a tuple. -- C Function: PyObject* PyMapping_Items (PyObject *o) `Return value: New reference.' On success, return a list of the items in object `o', where each item is a tuple containing a key-value pair. On failure, return ‘NULL’. Changed in version 3.7: Previously, the function returned a list or a tuple.  File: python.info, Node: Iterator Protocol, Next: Buffer Protocol, Prev: Mapping Protocol, Up: Abstract Objects Layer 7.7.5 Iterator Protocol ----------------------- There are two functions specifically for working with iterators. -- C Function: int PyIter_Check (PyObject *o) Return true if the object `o' supports the iterator protocol. -- C Function: PyObject* PyIter_Next (PyObject *o) `Return value: New reference.' Return the next value from the iteration `o'. The object must be an iterator (it is up to the caller to check this). If there are no remaining values, returns ‘NULL’ with no exception set. If an error occurs while retrieving the item, returns ‘NULL’ and passes along the exception. To write a loop which iterates over an iterator, the C code should look something like this: PyObject *iterator = PyObject_GetIter(obj); PyObject *item; if (iterator == NULL) { /* propagate error */ } while ((item = PyIter_Next(iterator))) { /* do something with item */ ... /* release reference when done */ Py_DECREF(item); } Py_DECREF(iterator); if (PyErr_Occurred()) { /* propagate error */ } else { /* continue doing useful work */ }  File: python.info, Node: Buffer Protocol, Next: Old Buffer Protocol, Prev: Iterator Protocol, Up: Abstract Objects Layer 7.7.6 Buffer Protocol --------------------- Certain objects available in Python wrap access to an underlying memory array or `buffer'. Such objects include the built-in *note bytes: 331. and *note bytearray: 332, and some extension types like *note array.array: 451. Third-party libraries may define their own types for special purposes, such as image processing or numeric analysis. While each of these types have their own semantics, they share the common characteristic of being backed by a possibly large memory buffer. It is then desirable, in some situations, to access that buffer directly and without intermediate copying. Python provides such a facility at the C level in the form of the *note buffer protocol: 1291. This protocol has two sides: - on the producer side, a type can export a “buffer interface” which allows objects of that type to expose information about their underlying buffer. This interface is described in the section *note Buffer Object Structures: 3a6e.; - on the consumer side, several means are available to obtain a pointer to the raw underlying data of an object (for example a method parameter). Simple objects such as *note bytes: 331. and *note bytearray: 332. expose their underlying buffer in byte-oriented form. Other forms are possible; for example, the elements exposed by an *note array.array: 451. can be multi-byte values. An example consumer of the buffer interface is the *note write(): 589. method of file objects: any object that can export a series of bytes through the buffer interface can be written to a file. While ‘write()’ only needs read-only access to the internal contents of the object passed to it, other methods such as *note readinto(): 1ccf. need write access to the contents of their argument. The buffer interface allows objects to selectively allow or reject exporting of read-write and read-only buffers. There are two ways for a consumer of the buffer interface to acquire a buffer over a target object: * call *note PyObject_GetBuffer(): d25. with the right parameters; * call *note PyArg_ParseTuple(): 26a. (or one of its siblings) with one of the ‘y*’, ‘w*’ or ‘s*’ *note format codes: 2d0. In both cases, *note PyBuffer_Release(): d54. must be called when the buffer isn’t needed anymore. Failure to do so could lead to various issues such as resource leaks. * Menu: * Buffer structure:: * Buffer request types:: * Complex arrays:: * Buffer-related functions::  File: python.info, Node: Buffer structure, Next: Buffer request types, Up: Buffer Protocol 7.7.6.1 Buffer structure ........................ Buffer structures (or simply “buffers”) are useful as a way to expose the binary data from another object to the Python programmer. They can also be used as a zero-copy slicing mechanism. Using their ability to reference a block of memory, it is possible to expose any data to the Python programmer quite easily. The memory could be a large, constant array in a C extension, it could be a raw block of memory for manipulation before passing to an operating system library, or it could be used to pass around structured data in its native, in-memory format. Contrary to most data types exposed by the Python interpreter, buffers are not *note PyObject: 4ba. pointers but rather simple C structures. This allows them to be created and copied very simply. When a generic wrapper around a buffer is needed, a *note memoryview: 3a71. object can be created. For short instructions how to write an exporting object, see *note Buffer Object Structures: 3a6e. For obtaining a buffer, see *note PyObject_GetBuffer(): d25. -- C Type: Py_buffer -- C Member: void *buf A pointer to the start of the logical structure described by the buffer fields. This can be any location within the underlying physical memory block of the exporter. For example, with negative *note strides: 3a73. the value may point to the end of the memory block. For *note contiguous: 1360. arrays, the value points to the beginning of the memory block. -- C Member: void *obj A new reference to the exporting object. The reference is owned by the consumer and automatically decremented and set to ‘NULL’ by *note PyBuffer_Release(): d54. The field is the equivalent of the return value of any standard C-API function. As a special case, for `temporary' buffers that are wrapped by *note PyMemoryView_FromBuffer(): 3a75. or *note PyBuffer_FillInfo(): 3a76. this field is ‘NULL’. In general, exporting objects MUST NOT use this scheme. -- C Member: Py_ssize_t len ‘product(shape) * itemsize’. For contiguous arrays, this is the length of the underlying memory block. For non-contiguous arrays, it is the length that the logical structure would have if it were copied to a contiguous representation. Accessing ‘((char *)buf)[0] up to ((char *)buf)[len-1]’ is only valid if the buffer has been obtained by a request that guarantees contiguity. In most cases such a request will be *note PyBUF_SIMPLE: 3a78. or *note PyBUF_WRITABLE: 3a79. -- C Member: int readonly An indicator of whether the buffer is read-only. This field is controlled by the *note PyBUF_WRITABLE: 3a79. flag. -- C Member: Py_ssize_t itemsize Item size in bytes of a single element. Same as the value of *note struct.calcsize(): 14b8. called on non-‘NULL’ *note format: 3a7c. values. Important exception: If a consumer requests a buffer without the *note PyBUF_FORMAT: 3a7d. flag, *note format: 3a7c. will be set to ‘NULL’, but *note itemsize: 3a7b. still has the value for the original format. If *note shape: 3a7e. is present, the equality ‘product(shape) * itemsize == len’ still holds and the consumer can use *note itemsize: 3a7b. to navigate the buffer. If *note shape: 3a7e. is ‘NULL’ as a result of a *note PyBUF_SIMPLE: 3a78. or a *note PyBUF_WRITABLE: 3a79. request, the consumer must disregard *note itemsize: 3a7b. and assume ‘itemsize == 1’. -- C Member: const char *format A `NUL' terminated string in *note struct: f8. module style syntax describing the contents of a single item. If this is ‘NULL’, ‘"B"’ (unsigned bytes) is assumed. This field is controlled by the *note PyBUF_FORMAT: 3a7d. flag. -- C Member: int ndim The number of dimensions the memory represents as an n-dimensional array. If it is ‘0’, *note buf: 3a72. points to a single item representing a scalar. In this case, *note shape: 3a7e, *note strides: 3a73. and *note suboffsets: 3a80. MUST be ‘NULL’. The macro ‘PyBUF_MAX_NDIM’ limits the maximum number of dimensions to 64. Exporters MUST respect this limit, consumers of multi-dimensional buffers SHOULD be able to handle up to ‘PyBUF_MAX_NDIM’ dimensions. -- C Member: Py_ssize_t *shape An array of ‘Py_ssize_t’ of length *note ndim: 3a7f. indicating the shape of the memory as an n-dimensional array. Note that ‘shape[0] * ... * shape[ndim-1] * itemsize’ MUST be equal to *note len: 3a77. Shape values are restricted to ‘shape[n] >= 0’. The case ‘shape[n] == 0’ requires special attention. See *note complex arrays: 3a81. for further information. The shape array is read-only for the consumer. -- C Member: Py_ssize_t *strides An array of ‘Py_ssize_t’ of length *note ndim: 3a7f. giving the number of bytes to skip to get to a new element in each dimension. Stride values can be any integer. For regular arrays, strides are usually positive, but a consumer MUST be able to handle the case ‘strides[n] <= 0’. See *note complex arrays: 3a81. for further information. The strides array is read-only for the consumer. -- C Member: Py_ssize_t *suboffsets An array of ‘Py_ssize_t’ of length *note ndim: 3a7f. If ‘suboffsets[n] >= 0’, the values stored along the nth dimension are pointers and the suboffset value dictates how many bytes to add to each pointer after de-referencing. A suboffset value that is negative indicates that no de-referencing should occur (striding in a contiguous memory block). If all suboffsets are negative (i.e. no de-referencing is needed), then this field must be ‘NULL’ (the default value). This type of array representation is used by the Python Imaging Library (PIL). See *note complex arrays: 3a81. for further information how to access elements of such an array. The suboffsets array is read-only for the consumer. -- C Member: void *internal This is for use internally by the exporting object. For example, this might be re-cast as an integer by the exporter and used to store flags about whether or not the shape, strides, and suboffsets arrays must be freed when the buffer is released. The consumer MUST NOT alter this value.  File: python.info, Node: Buffer request types, Next: Complex arrays, Prev: Buffer structure, Up: Buffer Protocol 7.7.6.2 Buffer request types ............................ Buffers are usually obtained by sending a buffer request to an exporting object via *note PyObject_GetBuffer(): d25. Since the complexity of the logical structure of the memory can vary drastically, the consumer uses the `flags' argument to specify the exact buffer type it can handle. All *note Py_buffer: b1b. fields are unambiguously defined by the request type. * Menu: * request-independent fields:: * readonly, format: readonly format. * shape, strides, suboffsets: shape strides suboffsets. * contiguity requests:: * compound requests::  File: python.info, Node: request-independent fields, Next: readonly format, Up: Buffer request types 7.7.6.3 request-independent fields .................................. The following fields are not influenced by `flags' and must always be filled in with the correct values: *note obj: 3a74, *note buf: 3a72, *note len: 3a77, *note itemsize: 3a7b, *note ndim: 3a7f.  File: python.info, Node: readonly format, Next: shape strides suboffsets, Prev: request-independent fields, Up: Buffer request types 7.7.6.4 readonly, format ........................ -- C Macro: PyBUF_WRITABLE Controls the *note readonly: 3a7a. field. If set, the exporter MUST provide a writable buffer or else report failure. Otherwise, the exporter MAY provide either a read-only or writable buffer, but the choice MUST be consistent for all consumers. -- C Macro: PyBUF_FORMAT Controls the *note format: 3a7c. field. If set, this field MUST be filled in correctly. Otherwise, this field MUST be ‘NULL’. *note PyBUF_WRITABLE: 3a79. can be |’d to any of the flags in the next section. Since *note PyBUF_SIMPLE: 3a78. is defined as 0, *note PyBUF_WRITABLE: 3a79. can be used as a stand-alone flag to request a simple writable buffer. *note PyBUF_FORMAT: 3a7d. can be |’d to any of the flags except *note PyBUF_SIMPLE: 3a78. The latter already implies format ‘B’ (unsigned bytes).  File: python.info, Node: shape strides suboffsets, Next: contiguity requests, Prev: readonly format, Up: Buffer request types 7.7.6.5 shape, strides, suboffsets .................................. The flags that control the logical structure of the memory are listed in decreasing order of complexity. Note that each flag contains all bits of the flags below it. Request shape strides suboffsets ----------------------------------------------------------------------------- -- C Macro: PyBUF_INDIRECT yes yes if needed -- C Macro: PyBUF_STRIDES yes yes NULL -- C Macro: PyBUF_ND yes NULL NULL -- C Macro: PyBUF_SIMPLE NULL NULL NULL  File: python.info, Node: contiguity requests, Next: compound requests, Prev: shape strides suboffsets, Up: Buffer request types 7.7.6.6 contiguity requests ........................... C or Fortran *note contiguity: 1360. can be explicitly requested, with and without stride information. Without stride information, the buffer must be C-contiguous. Request shape strides suboffsets contig ------------------------------------------------------------------------------------------------ -- C Macro: PyBUF_C_CONTIGUOUS yes yes NULL C -- C Macro: PyBUF_F_CONTIGUOUS yes yes NULL F -- C Macro: PyBUF_ANY_CONTIGUOUS yes yes NULL C or F *note PyBUF_ND: 3a8a. yes NULL NULL C  File: python.info, Node: compound requests, Prev: contiguity requests, Up: Buffer request types 7.7.6.7 compound requests ......................... All possible requests are fully defined by some combination of the flags in the previous section. For convenience, the buffer protocol provides frequently used combinations as single flags. In the following table `U' stands for undefined contiguity. The consumer would have to call *note PyBuffer_IsContiguous(): 3a90. to determine contiguity. Request shape strides suboffsets contig readonly format ------------------------------------------------------------------------------------------------------------------------ -- C Macro: PyBUF_FULL yes yes if needed U 0 yes -- C Macro: PyBUF_FULL_RO yes yes if needed U 1 or 0 yes -- C Macro: PyBUF_RECORDS yes yes NULL U 0 yes -- C Macro: PyBUF_RECORDS_RO yes yes NULL U 1 or 0 yes -- C Macro: PyBUF_STRIDED yes yes NULL U 0 NULL -- C Macro: PyBUF_STRIDED_RO yes yes NULL U 1 or 0 NULL -- C Macro: PyBUF_CONTIG yes NULL NULL C 0 NULL -- C Macro: PyBUF_CONTIG_RO yes NULL NULL C 1 or 0 NULL  File: python.info, Node: Complex arrays, Next: Buffer-related functions, Prev: Buffer request types, Up: Buffer Protocol 7.7.6.8 Complex arrays ...................... * Menu: * NumPy-style; shape and strides: NumPy-style shape and strides. * PIL-style; shape, strides and suboffsets: PIL-style shape strides and suboffsets.  File: python.info, Node: NumPy-style shape and strides, Next: PIL-style shape strides and suboffsets, Up: Complex arrays 7.7.6.9 NumPy-style: shape and strides ...................................... The logical structure of NumPy-style arrays is defined by *note itemsize: 3a7b, *note ndim: 3a7f, *note shape: 3a7e. and *note strides: 3a73. If ‘ndim == 0’, the memory location pointed to by *note buf: 3a72. is interpreted as a scalar of size *note itemsize: 3a7b. In that case, both *note shape: 3a7e. and *note strides: 3a73. are ‘NULL’. If *note strides: 3a73. is ‘NULL’, the array is interpreted as a standard n-dimensional C-array. Otherwise, the consumer must access an n-dimensional array as follows: ptr = (char *)buf + indices[0] * strides[0] + ... + indices[n-1] * strides[n-1]; item = *((typeof(item) *)ptr); As noted above, *note buf: 3a72. can point to any location within the actual memory block. An exporter can check the validity of a buffer with this function: def verify_structure(memlen, itemsize, ndim, shape, strides, offset): """Verify that the parameters represent a valid array within the bounds of the allocated memory: char *mem: start of the physical memory block memlen: length of the physical memory block offset: (char *)buf - mem """ if offset % itemsize: return False if offset < 0 or offset+itemsize > memlen: return False if any(v % itemsize for v in strides): return False if ndim <= 0: return ndim == 0 and not shape and not strides if 0 in shape: return True imin = sum(strides[j]*(shape[j]-1) for j in range(ndim) if strides[j] <= 0) imax = sum(strides[j]*(shape[j]-1) for j in range(ndim) if strides[j] > 0) return 0 <= offset+imin and offset+imax+itemsize <= memlen  File: python.info, Node: PIL-style shape strides and suboffsets, Prev: NumPy-style shape and strides, Up: Complex arrays 7.7.6.10 PIL-style: shape, strides and suboffsets ................................................. In addition to the regular items, PIL-style arrays can contain pointers that must be followed in order to get to the next element in a dimension. For example, the regular three-dimensional C-array ‘char v[2][2][3]’ can also be viewed as an array of 2 pointers to 2 two-dimensional arrays: ‘char (*v[2])[2][3]’. In suboffsets representation, those two pointers can be embedded at the start of *note buf: 3a72, pointing to two ‘char x[2][3]’ arrays that can be located anywhere in memory. Here is a function that returns a pointer to the element in an N-D array pointed to by an N-dimensional index when there are both non-‘NULL’ strides and suboffsets: void *get_item_pointer(int ndim, void *buf, Py_ssize_t *strides, Py_ssize_t *suboffsets, Py_ssize_t *indices) { char *pointer = (char*)buf; int i; for (i = 0; i < ndim; i++) { pointer += strides[i] * indices[i]; if (suboffsets[i] >=0 ) { pointer = *((char**)pointer) + suboffsets[i]; } } return (void*)pointer; }  File: python.info, Node: Buffer-related functions, Prev: Complex arrays, Up: Buffer Protocol 7.7.6.11 Buffer-related functions ................................. -- C Function: int PyObject_CheckBuffer (PyObject *obj) Return ‘1’ if `obj' supports the buffer interface otherwise ‘0’. When ‘1’ is returned, it doesn’t guarantee that *note PyObject_GetBuffer(): d25. will succeed. This function always succeeds. -- C Function: int PyObject_GetBuffer (PyObject *exporter, Py_buffer *view, int flags) Send a request to `exporter' to fill in `view' as specified by `flags'. If the exporter cannot provide a buffer of the exact type, it MUST raise ‘PyExc_BufferError’, set ‘view->obj’ to ‘NULL’ and return ‘-1’. On success, fill in `view', set ‘view->obj’ to a new reference to `exporter' and return 0. In the case of chained buffer providers that redirect requests to a single object, ‘view->obj’ MAY refer to this object instead of `exporter' (See *note Buffer Object Structures: 3a6e.). Successful calls to *note PyObject_GetBuffer(): d25. must be paired with calls to *note PyBuffer_Release(): d54, similar to ‘malloc()’ and ‘free()’. Thus, after the consumer is done with the buffer, *note PyBuffer_Release(): d54. must be called exactly once. -- C Function: void PyBuffer_Release (Py_buffer *view) Release the buffer `view' and decrement the reference count for ‘view->obj’. This function MUST be called when the buffer is no longer being used, otherwise reference leaks may occur. It is an error to call this function on a buffer that was not obtained via *note PyObject_GetBuffer(): d25. -- C Function: Py_ssize_t PyBuffer_SizeFromFormat (const char *) Return the implied *note itemsize: 3a7b. from *note format: 3a7c. This function is not yet implemented. -- C Function: int PyBuffer_IsContiguous (Py_buffer *view, char order) Return ‘1’ if the memory defined by the `view' is C-style (`order' is ‘'C'’) or Fortran-style (`order' is ‘'F'’) *note contiguous: 1360. or either one (`order' is ‘'A'’). Return ‘0’ otherwise. This function always succeeds. -- C Function: void* PyBuffer_GetPointer (Py_buffer *view, Py_ssize_t *indices) Get the memory area pointed to by the `indices' inside the given `view'. `indices' must point to an array of ‘view->ndim’ indices. -- C Function: int PyBuffer_FromContiguous (Py_buffer *view, void *buf, Py_ssize_t len, char fort) Copy contiguous `len' bytes from `buf' to `view'. `fort' can be ‘'C'’ or ‘'F'’ (for C-style or Fortran-style ordering). ‘0’ is returned on success, ‘-1’ on error. -- C Function: int PyBuffer_ToContiguous (void *buf, Py_buffer *src, Py_ssize_t len, char order) Copy `len' bytes from `src' to its contiguous representation in `buf'. `order' can be ‘'C'’ or ‘'F'’ or ‘'A'’ (for C-style or Fortran-style ordering or either one). ‘0’ is returned on success, ‘-1’ on error. This function fails if `len' != `src->len'. -- C Function: void PyBuffer_FillContiguousStrides (int ndims, Py_ssize_t *shape, Py_ssize_t *strides, int itemsize, char order) Fill the `strides' array with byte-strides of a *note contiguous: 1360. (C-style if `order' is ‘'C'’ or Fortran-style if `order' is ‘'F'’) array of the given shape with the given number of bytes per element. -- C Function: int PyBuffer_FillInfo (Py_buffer *view, PyObject *exporter, void *buf, Py_ssize_t len, int readonly, int flags) Handle buffer requests for an exporter that wants to expose `buf' of size `len' with writability set according to `readonly'. `buf' is interpreted as a sequence of unsigned bytes. The `flags' argument indicates the request type. This function always fills in `view' as specified by flags, unless `buf' has been designated as read-only and *note PyBUF_WRITABLE: 3a79. is set in `flags'. On success, set ‘view->obj’ to a new reference to `exporter' and return 0. Otherwise, raise ‘PyExc_BufferError’, set ‘view->obj’ to ‘NULL’ and return ‘-1’; If this function is used as part of a *note getbufferproc: 3a6e, `exporter' MUST be set to the exporting object and `flags' must be passed unmodified. Otherwise, `exporter' MUST be ‘NULL’.  File: python.info, Node: Old Buffer Protocol, Prev: Buffer Protocol, Up: Abstract Objects Layer 7.7.7 Old Buffer Protocol ------------------------- Deprecated since version 3.0. These functions were part of the “old buffer protocol” API in Python 2. In Python 3, this protocol doesn’t exist anymore but the functions are still exposed to ease porting 2.x code. They act as a compatibility wrapper around the *note new buffer protocol: 1291, but they don’t give you control over the lifetime of the resources acquired when a buffer is exported. Therefore, it is recommended that you call *note PyObject_GetBuffer(): d25. (or the ‘y*’ or ‘w*’ *note format codes: 2d0. with the *note PyArg_ParseTuple(): 26a. family of functions) to get a buffer view over an object, and *note PyBuffer_Release(): d54. when the buffer view can be released. -- C Function: int PyObject_AsCharBuffer (PyObject *obj, const char **buffer, Py_ssize_t *buffer_len) Returns a pointer to a read-only memory location usable as character-based input. The `obj' argument must support the single-segment character buffer interface. On success, returns ‘0’, sets `buffer' to the memory location and `buffer_len' to the buffer length. Returns ‘-1’ and sets a *note TypeError: 192. on error. -- C Function: int PyObject_AsReadBuffer (PyObject *obj, const void **buffer, Py_ssize_t *buffer_len) Returns a pointer to a read-only memory location containing arbitrary data. The `obj' argument must support the single-segment readable buffer interface. On success, returns ‘0’, sets `buffer' to the memory location and `buffer_len' to the buffer length. Returns ‘-1’ and sets a *note TypeError: 192. on error. -- C Function: int PyObject_CheckReadBuffer (PyObject *o) Returns ‘1’ if `o' supports the single-segment readable buffer interface. Otherwise returns ‘0’. This function always succeeds. Note that this function tries to get and release a buffer, and exceptions which occur while calling corresponding functions will get suppressed. To get error reporting use *note PyObject_GetBuffer(): d25. instead. -- C Function: int PyObject_AsWriteBuffer (PyObject *obj, void **buffer, Py_ssize_t *buffer_len) Returns a pointer to a writable memory location. The `obj' argument must support the single-segment, character buffer interface. On success, returns ‘0’, sets `buffer' to the memory location and `buffer_len' to the buffer length. Returns ‘-1’ and sets a *note TypeError: 192. on error.  File: python.info, Node: Concrete Objects Layer, Next: Initialization Finalization and Threads, Prev: Abstract Objects Layer, Up: Python/C API Reference Manual 7.8 Concrete Objects Layer ========================== The functions in this chapter are specific to certain Python object types. Passing them an object of the wrong type is not a good idea; if you receive an object from a Python program and you are not sure that it has the right type, you must perform a type check first; for example, to check that an object is a dictionary, use *note PyDict_Check(): 3aab. The chapter is structured like the “family tree” of Python object types. Warning: While the functions described in this chapter carefully check the type of the objects which are passed in, many of them do not check for ‘NULL’ being passed instead of a valid object. Allowing ‘NULL’ to be passed in can cause memory access violations and immediate termination of the interpreter. * Menu: * Fundamental Objects:: * Numeric Objects:: * Sequence Objects:: * Container Objects:: * Function Objects: Function Objects<2>. * Other Objects::  File: python.info, Node: Fundamental Objects, Next: Numeric Objects, Up: Concrete Objects Layer 7.8.1 Fundamental Objects ------------------------- This section describes Python type objects and the singleton object ‘None’. * Menu: * Type Objects: Type Objects<2>. * The None Object::  File: python.info, Node: Type Objects<2>, Next: The None Object, Up: Fundamental Objects 7.8.1.1 Type Objects .................... -- C Type: PyTypeObject The C structure of the objects used to describe built-in types. -- C Variable: PyObject* PyType_Type This is the type object for type objects; it is the same object as *note type: 608. in the Python layer. -- C Function: int PyType_Check (PyObject *o) Return true if the object `o' is a type object, including instances of types derived from the standard type object. Return false in all other cases. -- C Function: int PyType_CheckExact (PyObject *o) Return true if the object `o' is a type object, but not a subtype of the standard type object. Return false in all other cases. -- C Function: unsigned int PyType_ClearCache () Clear the internal lookup cache. Return the current version tag. -- C Function: unsigned long PyType_GetFlags (PyTypeObject* type) Return the *note tp_flags: 3ab6. member of `type'. This function is primarily meant for use with ‘Py_LIMITED_API’; the individual flag bits are guaranteed to be stable across Python releases, but access to *note tp_flags: 3ab6. itself is not part of the limited API. New in version 3.2. Changed in version 3.4: The return type is now ‘unsigned long’ rather than ‘long’. -- C Function: void PyType_Modified (PyTypeObject *type) Invalidate the internal lookup cache for the type and all of its subtypes. This function must be called after any manual modification of the attributes or base classes of the type. -- C Function: int PyType_HasFeature (PyTypeObject *o, int feature) Return true if the type object `o' sets the feature `feature'. Type features are denoted by single bit flags. -- C Function: int PyType_IS_GC (PyTypeObject *o) Return true if the type object includes support for the cycle detector; this tests the type flag *note Py_TPFLAGS_HAVE_GC: 388e. -- C Function: int PyType_IsSubtype (PyTypeObject *a, PyTypeObject *b) Return true if `a' is a subtype of `b'. This function only checks for actual subtypes, which means that *note __subclasscheck__(): 10f3. is not called on `b'. Call *note PyObject_IsSubclass(): 79e. to do the same check that *note issubclass(): 450. would do. -- C Function: PyObject* PyType_GenericAlloc (PyTypeObject *type, Py_ssize_t nitems) `Return value: New reference.' Generic handler for the *note tp_alloc: 3881. slot of a type object. Use Python’s default memory allocation mechanism to allocate a new instance and initialize all its contents to ‘NULL’. -- C Function: PyObject* PyType_GenericNew (PyTypeObject *type, PyObject *args, PyObject *kwds) `Return value: New reference.' Generic handler for the *note tp_new: 387c. slot of a type object. Create a new instance using the type’s *note tp_alloc: 3881. slot. -- C Function: int PyType_Ready (PyTypeObject *type) Finalize a type object. This should be called on all type objects to finish their initialization. This function is responsible for adding inherited slots from a type’s base class. Return ‘0’ on success, or return ‘-1’ and sets an exception on error. -- C Function: void* PyType_GetSlot (PyTypeObject *type, int slot) Return the function pointer stored in the given slot. If the result is ‘NULL’, this indicates that either the slot is ‘NULL’, or that the function was called with invalid parameters. Callers will typically cast the result pointer into the appropriate function type. See ‘PyType_Slot.slot’ for possible values of the `slot' argument. An exception is raised if `type' is not a heap type. New in version 3.4. * Menu: * Creating Heap-Allocated Types::  File: python.info, Node: Creating Heap-Allocated Types, Up: Type Objects<2> 7.8.1.2 Creating Heap-Allocated Types ..................................... The following functions and structs are used to create *note heap types: 3abc. -- C Function: PyObject* PyType_FromSpecWithBases (PyType_Spec *spec, PyObject *bases) `Return value: New reference.' Creates and returns a heap type object from the `spec' (*note Py_TPFLAGS_HEAPTYPE: 3abe.). If `bases' is a tuple, the created heap type contains all types contained in it as base types. If `bases' is ‘NULL’, the `Py_tp_bases' slot is used instead. If that also is ‘NULL’, the `Py_tp_base' slot is used instead. If that also is ‘NULL’, the new type derives from *note object: 2b0. This function calls *note PyType_Ready(): 3882. on the new type. New in version 3.3. -- C Function: PyObject* PyType_FromSpec (PyType_Spec *spec) `Return value: New reference.' Equivalent to ‘PyType_FromSpecWithBases(spec, NULL)’. -- C Type: PyType_Spec Structure defining a type’s behavior. -- C Member: const char* PyType_Spec.name Name of the type, used to set *note PyTypeObject.tp_name: 389b. -- C Member: int PyType_Spec.basicsize -- C Member: int PyType_Spec.itemsize Size of the instance in bytes, used to set *note PyTypeObject.tp_basicsize: 3879. and *note PyTypeObject.tp_itemsize: 3878. -- C Member: int PyType_Spec.flags Type flags, used to set *note PyTypeObject.tp_flags: 3ab6. If the ‘Py_TPFLAGS_HEAPTYPE’ flag is not set, *note PyType_FromSpecWithBases(): 3abd. sets it automatically. -- C Member: PyType_Slot *PyType_Spec.slots Array of *note PyType_Slot: 3ac5. structures. Terminated by the special slot value ‘{0, NULL}’. -- C Type: PyType_Slot Structure defining optional functionality of a type, containing a slot ID and a value pointer. -- C Member: int PyType_Slot.slot A slot ID. Slot IDs are named like the field names of the structures *note PyTypeObject: 2d6, *note PyNumberMethods: d81, *note PySequenceMethods: 38aa, *note PyMappingMethods: 38ab. and *note PyAsyncMethods: 3ac7. with an added ‘Py_’ prefix. For example, use: * ‘Py_tp_dealloc’ to set *note PyTypeObject.tp_dealloc: 387f. * ‘Py_nb_add’ to set *note PyNumberMethods.nb_add: 3ac8. * ‘Py_sq_length’ to set *note PySequenceMethods.sq_length: 3ac9. The following fields cannot be set using *note PyType_Spec: 3abf. and *note PyType_Slot: 3ac5.: * *note tp_dict: 3aca. * *note tp_mro: 3acb. * *note tp_cache: 3acc. * *note tp_subclasses: 3acd. * *note tp_weaklist: 3ace. * ‘tp_print’ * *note tp_weaklistoffset: 38af. * *note tp_dictoffset: 3acf. * *note bf_getbuffer: 3ad0. * *note bf_releasebuffer: 39c9. Setting ‘Py_tp_bases’ or ‘Py_tp_base’ may be problematic on some platforms. To avoid issues, use the `bases' argument of ‘PyType_FromSpecWithBases()’ instead. -- C Member: void *PyType_Slot.pfunc The desired value of the slot. In most cases, this is a pointer to a function. May not be ‘NULL’.  File: python.info, Node: The None Object, Prev: Type Objects<2>, Up: Fundamental Objects 7.8.1.3 The ‘None’ Object ......................... Note that the *note PyTypeObject: 2d6. for ‘None’ is not directly exposed in the Python/C API. Since ‘None’ is a singleton, testing for object identity (using ‘==’ in C) is sufficient. There is no ‘PyNone_Check()’ function for the same reason. -- C Variable: PyObject* Py_None The Python ‘None’ object, denoting lack of value. This object has no methods. It needs to be treated just like any other object with respect to reference counts. -- C Macro: Py_RETURN_NONE Properly handle returning *note Py_None: 3844. from within a C function (that is, increment the reference count of ‘None’ and return it.)  File: python.info, Node: Numeric Objects, Next: Sequence Objects, Prev: Fundamental Objects, Up: Concrete Objects Layer 7.8.2 Numeric Objects --------------------- * Menu: * Integer Objects:: * Boolean Objects:: * Floating Point Objects:: * Complex Number Objects::  File: python.info, Node: Integer Objects, Next: Boolean Objects, Up: Numeric Objects 7.8.2.1 Integer Objects ....................... All integers are implemented as “long” integer objects of arbitrary size. On error, most ‘PyLong_As*’ APIs return ‘(return type)-1’ which cannot be distinguished from a number. Use *note PyErr_Occurred(): 383f. to disambiguate. -- C Type: PyLongObject This subtype of *note PyObject: 4ba. represents a Python integer object. -- C Variable: PyTypeObject PyLong_Type This instance of *note PyTypeObject: 2d6. represents the Python integer type. This is the same object as *note int: 184. in the Python layer. -- C Function: int PyLong_Check (PyObject *p) Return true if its argument is a *note PyLongObject: 3ada. or a subtype of *note PyLongObject: 3ada. -- C Function: int PyLong_CheckExact (PyObject *p) Return true if its argument is a *note PyLongObject: 3ada, but not a subtype of *note PyLongObject: 3ada. -- C Function: PyObject* PyLong_FromLong (long v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from `v', or ‘NULL’ on failure. The current implementation keeps an array of integer objects for all integers between ‘-5’ and ‘256’, when you create an int in that range you actually just get back a reference to the existing object. So it should be possible to change the value of ‘1’. I suspect the behaviour of Python in this case is undefined. :-) -- C Function: PyObject* PyLong_FromUnsignedLong (unsigned long v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from a C ‘unsigned long’, or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromSsize_t (Py_ssize_t v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from a C ‘Py_ssize_t’, or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromSize_t (size_t v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from a C ‘size_t’, or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromLongLong (long long v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from a C ‘long long’, or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromUnsignedLongLong (unsigned long long v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from a C ‘unsigned long long’, or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromDouble (double v) `Return value: New reference.' Return a new *note PyLongObject: 3ada. object from the integer part of `v', or ‘NULL’ on failure. -- C Function: PyObject* PyLong_FromString (const char *str, char **pend, int base) `Return value: New reference.' Return a new *note PyLongObject: 3ada. based on the string value in `str', which is interpreted according to the radix in `base'. If `pend' is non-‘NULL’, `*pend' will point to the first character in `str' which follows the representation of the number. If `base' is ‘0’, `str' is interpreted using the *note Integer literals: 109f. definition; in this case, leading zeros in a non-zero decimal number raises a *note ValueError: 1fb. If `base' is not ‘0’, it must be between ‘2’ and ‘36’, inclusive. Leading spaces and single underscores after a base specifier and between digits are ignored. If there are no digits, *note ValueError: 1fb. will be raised. -- C Function: PyObject* PyLong_FromUnicode (Py_UNICODE *u, Py_ssize_t length, int base) `Return value: New reference.' Convert a sequence of Unicode digits to a Python integer value. Deprecated since version 3.3, will be removed in version 3.10: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyLong_FromUnicodeObject(): 3ae6. -- C Function: PyObject* PyLong_FromUnicodeObject (PyObject *u, int base) `Return value: New reference.' Convert a sequence of Unicode digits in the string `u' to a Python integer value. New in version 3.3. -- C Function: PyObject* PyLong_FromVoidPtr (void *p) `Return value: New reference.' Create a Python integer from the pointer `p'. The pointer value can be retrieved from the resulting value using *note PyLong_AsVoidPtr(): 3ae8. -- C Function: long PyLong_AsLong (PyObject *obj) Return a C ‘long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `obj' is out of range for a ‘long’. Returns ‘-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: long PyLong_AsLongAndOverflow (PyObject *obj, int *overflow) Return a C ‘long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. If the value of `obj' is greater than ‘LONG_MAX’ or less than ‘LONG_MIN’, set `*overflow' to ‘1’ or ‘-1’, respectively, and return ‘-1’; otherwise, set `*overflow' to ‘0’. If any other exception occurs set `*overflow' to ‘0’ and return ‘-1’ as usual. Returns ‘-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: long long PyLong_AsLongLong (PyObject *obj) Return a C ‘long long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `obj' is out of range for a ‘long long’. Returns ‘-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: long long PyLong_AsLongLongAndOverflow (PyObject *obj, int *overflow) Return a C ‘long long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. If the value of `obj' is greater than ‘PY_LLONG_MAX’ or less than ‘PY_LLONG_MIN’, set `*overflow' to ‘1’ or ‘-1’, respectively, and return ‘-1’; otherwise, set `*overflow' to ‘0’. If any other exception occurs set `*overflow' to ‘0’ and return ‘-1’ as usual. Returns ‘-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. New in version 3.2. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: Py_ssize_t PyLong_AsSsize_t (PyObject *pylong) Return a C ‘Py_ssize_t’ representation of `pylong'. `pylong' must be an instance of *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `pylong' is out of range for a ‘Py_ssize_t’. Returns ‘-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: unsigned long PyLong_AsUnsignedLong (PyObject *pylong) Return a C ‘unsigned long’ representation of `pylong'. `pylong' must be an instance of *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `pylong' is out of range for a ‘unsigned long’. Returns ‘(unsigned long)-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: size_t PyLong_AsSize_t (PyObject *pylong) Return a C ‘size_t’ representation of `pylong'. `pylong' must be an instance of *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `pylong' is out of range for a ‘size_t’. Returns ‘(size_t)-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: unsigned long long PyLong_AsUnsignedLongLong (PyObject *pylong) Return a C ‘unsigned long long’ representation of `pylong'. `pylong' must be an instance of *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `pylong' is out of range for an ‘unsigned long long’. Returns ‘(unsigned long long)-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.1: A negative `pylong' now raises *note OverflowError: 960, not *note TypeError: 192. -- C Function: unsigned long PyLong_AsUnsignedLongMask (PyObject *obj) Return a C ‘unsigned long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. If the value of `obj' is out of range for an ‘unsigned long’, return the reduction of that value modulo ‘ULONG_MAX + 1’. Returns ‘(unsigned long)-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: unsigned long long PyLong_AsUnsignedLongLongMask (PyObject *obj) Return a C ‘unsigned long long’ representation of `obj'. If `obj' is not an instance of *note PyLongObject: 3ada, first call its *note __index__(): 18a. or *note __int__(): 18b. method (if present) to convert it to a *note PyLongObject: 3ada. If the value of `obj' is out of range for an ‘unsigned long long’, return the reduction of that value modulo ‘PY_ULLONG_MAX + 1’. Returns ‘(unsigned long long)-1’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. Changed in version 3.8: Use *note __index__(): 18a. if available. Deprecated since version 3.8: Using *note __int__(): 18b. is deprecated. -- C Function: double PyLong_AsDouble (PyObject *pylong) Return a C ‘double’ representation of `pylong'. `pylong' must be an instance of *note PyLongObject: 3ada. Raise *note OverflowError: 960. if the value of `pylong' is out of range for a ‘double’. Returns ‘-1.0’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: void* PyLong_AsVoidPtr (PyObject *pylong) Convert a Python integer `pylong' to a C ‘void’ pointer. If `pylong' cannot be converted, an *note OverflowError: 960. will be raised. This is only assured to produce a usable ‘void’ pointer for values created with *note PyLong_FromVoidPtr(): 3ae7. Returns ‘NULL’ on error. Use *note PyErr_Occurred(): 383f. to disambiguate.  File: python.info, Node: Boolean Objects, Next: Floating Point Objects, Prev: Integer Objects, Up: Numeric Objects 7.8.2.2 Boolean Objects ....................... Booleans in Python are implemented as a subclass of integers. There are only two booleans, ‘Py_False’ and ‘Py_True’. As such, the normal creation and deletion functions don’t apply to booleans. The following macros are available, however. -- C Function: int PyBool_Check (PyObject *o) Return true if `o' is of type ‘PyBool_Type’. -- C Variable: PyObject* Py_False The Python ‘False’ object. This object has no methods. It needs to be treated just like any other object with respect to reference counts. -- C Variable: PyObject* Py_True The Python ‘True’ object. This object has no methods. It needs to be treated just like any other object with respect to reference counts. -- C Macro: Py_RETURN_FALSE Return ‘Py_False’ from a function, properly incrementing its reference count. -- C Macro: Py_RETURN_TRUE Return ‘Py_True’ from a function, properly incrementing its reference count. -- C Function: PyObject* PyBool_FromLong (long v) `Return value: New reference.' Return a new reference to ‘Py_True’ or ‘Py_False’ depending on the truth value of `v'.  File: python.info, Node: Floating Point Objects, Next: Complex Number Objects, Prev: Boolean Objects, Up: Numeric Objects 7.8.2.3 Floating Point Objects .............................. -- C Type: PyFloatObject This subtype of *note PyObject: 4ba. represents a Python floating point object. -- C Variable: PyTypeObject PyFloat_Type This instance of *note PyTypeObject: 2d6. represents the Python floating point type. This is the same object as *note float: 187. in the Python layer. -- C Function: int PyFloat_Check (PyObject *p) Return true if its argument is a *note PyFloatObject: 3afa. or a subtype of *note PyFloatObject: 3afa. -- C Function: int PyFloat_CheckExact (PyObject *p) Return true if its argument is a *note PyFloatObject: 3afa, but not a subtype of *note PyFloatObject: 3afa. -- C Function: PyObject* PyFloat_FromString (PyObject *str) `Return value: New reference.' Create a *note PyFloatObject: 3afa. object based on the string value in `str', or ‘NULL’ on failure. -- C Function: PyObject* PyFloat_FromDouble (double v) `Return value: New reference.' Create a *note PyFloatObject: 3afa. object from `v', or ‘NULL’ on failure. -- C Function: double PyFloat_AsDouble (PyObject *pyfloat) Return a C ‘double’ representation of the contents of `pyfloat'. If `pyfloat' is not a Python floating point object but has a *note __float__(): 18c. method, this method will first be called to convert `pyfloat' into a float. If ‘__float__()’ is not defined then it falls back to *note __index__(): 18a. This method returns ‘-1.0’ upon failure, so one should call *note PyErr_Occurred(): 383f. to check for errors. Changed in version 3.8: Use *note __index__(): 18a. if available. -- C Function: double PyFloat_AS_DOUBLE (PyObject *pyfloat) Return a C ‘double’ representation of the contents of `pyfloat', but without error checking. -- C Function: PyObject* PyFloat_GetInfo (void) `Return value: New reference.' Return a structseq instance which contains information about the precision, minimum and maximum values of a float. It’s a thin wrapper around the header file ‘float.h’. -- C Function: double PyFloat_GetMax () Return the maximum representable finite float `DBL_MAX' as C ‘double’. -- C Function: double PyFloat_GetMin () Return the minimum normalized positive float `DBL_MIN' as C ‘double’. -- C Function: int PyFloat_ClearFreeList () Clear the float free list. Return the number of items that could not be freed.  File: python.info, Node: Complex Number Objects, Prev: Floating Point Objects, Up: Numeric Objects 7.8.2.4 Complex Number Objects .............................. Python’s complex number objects are implemented as two distinct types when viewed from the C API: one is the Python object exposed to Python programs, and the other is a C structure which represents the actual complex number value. The API provides functions for working with both. * Menu: * Complex Numbers as C Structures:: * Complex Numbers as Python Objects::  File: python.info, Node: Complex Numbers as C Structures, Next: Complex Numbers as Python Objects, Up: Complex Number Objects 7.8.2.5 Complex Numbers as C Structures ....................................... Note that the functions which accept these structures as parameters and return them as results do so `by value' rather than dereferencing them through pointers. This is consistent throughout the API. -- C Type: Py_complex The C structure which corresponds to the value portion of a Python complex number object. Most of the functions for dealing with complex number objects use structures of this type as input or output values, as appropriate. It is defined as: typedef struct { double real; double imag; } Py_complex; -- C Function: Py_complex _Py_c_sum (Py_complex left, Py_complex right) Return the sum of two complex numbers, using the C *note Py_complex: 39cb. representation. -- C Function: Py_complex _Py_c_diff (Py_complex left, Py_complex right) Return the difference between two complex numbers, using the C *note Py_complex: 39cb. representation. -- C Function: Py_complex _Py_c_neg (Py_complex complex) Return the negation of the complex number `complex', using the C *note Py_complex: 39cb. representation. -- C Function: Py_complex _Py_c_prod (Py_complex left, Py_complex right) Return the product of two complex numbers, using the C *note Py_complex: 39cb. representation. -- C Function: Py_complex _Py_c_quot (Py_complex dividend, Py_complex divisor) Return the quotient of two complex numbers, using the C *note Py_complex: 39cb. representation. If `divisor' is null, this method returns zero and sets ‘errno’ to ‘EDOM’. -- C Function: Py_complex _Py_c_pow (Py_complex num, Py_complex exp) Return the exponentiation of `num' by `exp', using the C *note Py_complex: 39cb. representation. If `num' is null and `exp' is not a positive real number, this method returns zero and sets ‘errno’ to ‘EDOM’.  File: python.info, Node: Complex Numbers as Python Objects, Prev: Complex Numbers as C Structures, Up: Complex Number Objects 7.8.2.6 Complex Numbers as Python Objects ......................................... -- C Type: PyComplexObject This subtype of *note PyObject: 4ba. represents a Python complex number object. -- C Variable: PyTypeObject PyComplex_Type This instance of *note PyTypeObject: 2d6. represents the Python complex number type. It is the same object as *note complex: 189. in the Python layer. -- C Function: int PyComplex_Check (PyObject *p) Return true if its argument is a *note PyComplexObject: 3b0d. or a subtype of *note PyComplexObject: 3b0d. -- C Function: int PyComplex_CheckExact (PyObject *p) Return true if its argument is a *note PyComplexObject: 3b0d, but not a subtype of *note PyComplexObject: 3b0d. -- C Function: PyObject* PyComplex_FromCComplex (Py_complex v) `Return value: New reference.' Create a new Python complex number object from a C *note Py_complex: 39cb. value. -- C Function: PyObject* PyComplex_FromDoubles (double real, double imag) `Return value: New reference.' Return a new *note PyComplexObject: 3b0d. object from `real' and `imag'. -- C Function: double PyComplex_RealAsDouble (PyObject *op) Return the real part of `op' as a C ‘double’. -- C Function: double PyComplex_ImagAsDouble (PyObject *op) Return the imaginary part of `op' as a C ‘double’. -- C Function: Py_complex PyComplex_AsCComplex (PyObject *op) Return the *note Py_complex: 39cb. value of the complex number `op'. If `op' is not a Python complex number object but has a *note __complex__(): 18d. method, this method will first be called to convert `op' to a Python complex number object. If ‘__complex__()’ is not defined then it falls back to *note __float__(): 18c. If ‘__float__()’ is not defined then it falls back to *note __index__(): 18a. Upon failure, this method returns ‘-1.0’ as a real value. Changed in version 3.8: Use *note __index__(): 18a. if available.  File: python.info, Node: Sequence Objects, Next: Container Objects, Prev: Numeric Objects, Up: Concrete Objects Layer 7.8.3 Sequence Objects ---------------------- Generic operations on sequence objects were discussed in the previous chapter; this section deals with the specific kinds of sequence objects that are intrinsic to the Python language. * Menu: * Bytes Objects: Bytes Objects<2>. * Byte Array Objects:: * Unicode Objects and Codecs:: * Tuple Objects:: * Struct Sequence Objects:: * List Objects::  File: python.info, Node: Bytes Objects<2>, Next: Byte Array Objects, Up: Sequence Objects 7.8.3.1 Bytes Objects ..................... These functions raise *note TypeError: 192. when expecting a bytes parameter and are called with a non-bytes parameter. -- C Type: PyBytesObject This subtype of *note PyObject: 4ba. represents a Python bytes object. -- C Variable: PyTypeObject PyBytes_Type This instance of *note PyTypeObject: 2d6. represents the Python bytes type; it is the same object as *note bytes: 331. in the Python layer. -- C Function: int PyBytes_Check (PyObject *o) Return true if the object `o' is a bytes object or an instance of a subtype of the bytes type. -- C Function: int PyBytes_CheckExact (PyObject *o) Return true if the object `o' is a bytes object, but not an instance of a subtype of the bytes type. -- C Function: PyObject* PyBytes_FromString (const char *v) `Return value: New reference.' Return a new bytes object with a copy of the string `v' as value on success, and ‘NULL’ on failure. The parameter `v' must not be ‘NULL’; it will not be checked. -- C Function: PyObject* PyBytes_FromStringAndSize (const char *v, Py_ssize_t len) `Return value: New reference.' Return a new bytes object with a copy of the string `v' as value and length `len' on success, and ‘NULL’ on failure. If `v' is ‘NULL’, the contents of the bytes object are uninitialized. -- C Function: PyObject* PyBytes_FromFormat (const char *format, ...) `Return value: New reference.' Take a C ‘printf()’-style `format' string and a variable number of arguments, calculate the size of the resulting Python bytes object and return a bytes object with the values formatted into it. The variable arguments must be C types and must correspond exactly to the format characters in the `format' string. The following format characters are allowed: Format Characters Type Comment --------------------------------------------------------------------------------- ‘%%’ `n/a' The literal % character. ‘%c’ int A single byte, represented as a C int. ‘%d’ int Equivalent to ‘printf("%d")’. (1) ‘%u’ unsigned int Equivalent to ‘printf("%u")’. (2) ‘%ld’ long Equivalent to ‘printf("%ld")’. (3) ‘%lu’ unsigned long Equivalent to ‘printf("%lu")’. (4) ‘%zd’ Py_ssize_t Equivalent to ‘printf("%zd")’. (5) ‘%zu’ size_t Equivalent to ‘printf("%zu")’. (6) ‘%i’ int Equivalent to ‘printf("%i")’. (7) ‘%x’ int Equivalent to ‘printf("%x")’. (8) ‘%s’ const char* A null-terminated C character array. ‘%p’ const void* The hex representation of a C pointer. Mostly equivalent to ‘printf("%p")’ except that it is guaranteed to start with the literal ‘0x’ regardless of what the platform’s ‘printf’ yields. An unrecognized format character causes all the rest of the format string to be copied as-is to the result object, and any extra arguments discarded. -- C Function: PyObject* PyBytes_FromFormatV (const char *format, va_list vargs) `Return value: New reference.' Identical to *note PyBytes_FromFormat(): 3b1d. except that it takes exactly two arguments. -- C Function: PyObject* PyBytes_FromObject (PyObject *o) `Return value: New reference.' Return the bytes representation of object `o' that implements the buffer protocol. -- C Function: Py_ssize_t PyBytes_Size (PyObject *o) Return the length of the bytes in bytes object `o'. -- C Function: Py_ssize_t PyBytes_GET_SIZE (PyObject *o) Macro form of *note PyBytes_Size(): 3b20. but without error checking. -- C Function: char* PyBytes_AsString (PyObject *o) Return a pointer to the contents of `o'. The pointer refers to the internal buffer of `o', which consists of ‘len(o) + 1’ bytes. The last byte in the buffer is always null, regardless of whether there are any other null bytes. The data must not be modified in any way, unless the object was just created using ‘PyBytes_FromStringAndSize(NULL, size)’. It must not be deallocated. If `o' is not a bytes object at all, *note PyBytes_AsString(): 3b22. returns ‘NULL’ and raises *note TypeError: 192. -- C Function: char* PyBytes_AS_STRING (PyObject *string) Macro form of *note PyBytes_AsString(): 3b22. but without error checking. -- C Function: int PyBytes_AsStringAndSize (PyObject *obj, char **buffer, Py_ssize_t *length) Return the null-terminated contents of the object `obj' through the output variables `buffer' and `length'. If `length' is ‘NULL’, the bytes object may not contain embedded null bytes; if it does, the function returns ‘-1’ and a *note ValueError: 1fb. is raised. The buffer refers to an internal buffer of `obj', which includes an additional null byte at the end (not counted in `length'). The data must not be modified in any way, unless the object was just created using ‘PyBytes_FromStringAndSize(NULL, size)’. It must not be deallocated. If `obj' is not a bytes object at all, *note PyBytes_AsStringAndSize(): 3b24. returns ‘-1’ and raises *note TypeError: 192. Changed in version 3.5: Previously, *note TypeError: 192. was raised when embedded null bytes were encountered in the bytes object. -- C Function: void PyBytes_Concat (PyObject **bytes, PyObject *newpart) Create a new bytes object in `*bytes' containing the contents of `newpart' appended to `bytes'; the caller will own the new reference. The reference to the old value of `bytes' will be stolen. If the new object cannot be created, the old reference to `bytes' will still be discarded and the value of `*bytes' will be set to ‘NULL’; the appropriate exception will be set. -- C Function: void PyBytes_ConcatAndDel (PyObject **bytes, PyObject *newpart) Create a new bytes object in `*bytes' containing the contents of `newpart' appended to `bytes'. This version decrements the reference count of `newpart'. -- C Function: int _PyBytes_Resize (PyObject **bytes, Py_ssize_t newsize) A way to resize a bytes object even though it is “immutable”. Only use this to build up a brand new bytes object; don’t use this if the bytes may already be known in other parts of the code. It is an error to call this function if the refcount on the input bytes object is not one. Pass the address of an existing bytes object as an lvalue (it may be written into), and the new size desired. On success, `*bytes' holds the resized bytes object and ‘0’ is returned; the address in `*bytes' may differ from its input value. If the reallocation fails, the original bytes object at `*bytes' is deallocated, `*bytes' is set to ‘NULL’, *note MemoryError: 13af. is set, and ‘-1’ is returned. ---------- Footnotes ---------- (1) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (2) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (3) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (4) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (5) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (6) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (7) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given. (8) (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given.  File: python.info, Node: Byte Array Objects, Next: Unicode Objects and Codecs, Prev: Bytes Objects<2>, Up: Sequence Objects 7.8.3.2 Byte Array Objects .......................... -- C Type: PyByteArrayObject This subtype of *note PyObject: 4ba. represents a Python bytearray object. -- C Variable: PyTypeObject PyByteArray_Type This instance of *note PyTypeObject: 2d6. represents the Python bytearray type; it is the same object as *note bytearray: 332. in the Python layer. * Menu: * Type check macros:: * Direct API functions:: * Macros::  File: python.info, Node: Type check macros, Next: Direct API functions, Up: Byte Array Objects 7.8.3.3 Type check macros ......................... -- C Function: int PyByteArray_Check (PyObject *o) Return true if the object `o' is a bytearray object or an instance of a subtype of the bytearray type. -- C Function: int PyByteArray_CheckExact (PyObject *o) Return true if the object `o' is a bytearray object, but not an instance of a subtype of the bytearray type.  File: python.info, Node: Direct API functions, Next: Macros, Prev: Type check macros, Up: Byte Array Objects 7.8.3.4 Direct API functions ............................ -- C Function: PyObject* PyByteArray_FromObject (PyObject *o) `Return value: New reference.' Return a new bytearray object from any object, `o', that implements the *note buffer protocol: 1291. -- C Function: PyObject* PyByteArray_FromStringAndSize (const char *string, Py_ssize_t len) `Return value: New reference.' Create a new bytearray object from `string' and its length, `len'. On failure, ‘NULL’ is returned. -- C Function: PyObject* PyByteArray_Concat (PyObject *a, PyObject *b) `Return value: New reference.' Concat bytearrays `a' and `b' and return a new bytearray with the result. -- C Function: Py_ssize_t PyByteArray_Size (PyObject *bytearray) Return the size of `bytearray' after checking for a ‘NULL’ pointer. -- C Function: char* PyByteArray_AsString (PyObject *bytearray) Return the contents of `bytearray' as a char array after checking for a ‘NULL’ pointer. The returned array always has an extra null byte appended. -- C Function: int PyByteArray_Resize (PyObject *bytearray, Py_ssize_t len) Resize the internal buffer of `bytearray' to `len'.  File: python.info, Node: Macros, Prev: Direct API functions, Up: Byte Array Objects 7.8.3.5 Macros .............. These macros trade safety for speed and they don’t check pointers. -- C Function: char* PyByteArray_AS_STRING (PyObject *bytearray) Macro version of *note PyByteArray_AsString(): 3b33. -- C Function: Py_ssize_t PyByteArray_GET_SIZE (PyObject *bytearray) Macro version of *note PyByteArray_Size(): 3b32.  File: python.info, Node: Unicode Objects and Codecs, Next: Tuple Objects, Prev: Byte Array Objects, Up: Sequence Objects 7.8.3.6 Unicode Objects and Codecs .................................. * Menu: * Unicode Objects:: * Built-in Codecs:: * Methods and Slot Functions::  File: python.info, Node: Unicode Objects, Next: Built-in Codecs, Up: Unicode Objects and Codecs 7.8.3.7 Unicode Objects ....................... Since the implementation of PEP 393(1) in Python 3.3, Unicode objects internally use a variety of representations, in order to allow handling the complete range of Unicode characters while staying memory efficient. There are special cases for strings where all code points are below 128, 256, or 65536; otherwise, code points must be below 1114112 (which is the full Unicode range). *note Py_UNICODE*: aee. and UTF-8 representations are created on demand and cached in the Unicode object. The *note Py_UNICODE*: aee. representation is deprecated and inefficient. Due to the transition between the old APIs and the new APIs, Unicode objects can internally be in two states depending on how they were created: * “canonical” Unicode objects are all objects created by a non-deprecated Unicode API. They use the most efficient representation allowed by the implementation. * “legacy” Unicode objects have been created through one of the deprecated APIs (typically *note PyUnicode_FromUnicode(): aef.) and only bear the *note Py_UNICODE*: aee. representation; you will have to call *note PyUnicode_READY(): ad6. on them before calling any other API. Note: The “legacy” Unicode object will be removed in Python 3.12 with deprecated APIs. All Unicode objects will be “canonical” since then. See PEP 623(2) for more information. * Menu: * Unicode Type:: * Unicode Character Properties:: * Creating and accessing Unicode strings:: * Deprecated Py_UNICODE APIs:: * Locale Encoding:: * File System Encoding:: * wchar_t Support:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393 (2) https://www.python.org/dev/peps/pep-0623  File: python.info, Node: Unicode Type, Next: Unicode Character Properties, Up: Unicode Objects 7.8.3.8 Unicode Type .................... These are the basic Unicode object types used for the Unicode implementation in Python: -- C Type: Py_UCS4 -- C Type: Py_UCS2 -- C Type: Py_UCS1 These types are typedefs for unsigned integer types wide enough to contain characters of 32 bits, 16 bits and 8 bits, respectively. When dealing with single Unicode characters, use *note Py_UCS4: ad3. New in version 3.3. -- C Type: Py_UNICODE This is a typedef of ‘wchar_t’, which is a 16-bit type or 32-bit type depending on the platform. Changed in version 3.3: In previous versions, this was a 16-bit type or a 32-bit type depending on whether you selected a “narrow” or “wide” Unicode version of Python at build time. -- C Type: PyASCIIObject -- C Type: PyCompactUnicodeObject -- C Type: PyUnicodeObject These subtypes of *note PyObject: 4ba. represent a Python Unicode object. In almost all cases, they shouldn’t be used directly, since all API functions that deal with Unicode objects take and return *note PyObject: 4ba. pointers. New in version 3.3. -- C Variable: PyTypeObject PyUnicode_Type This instance of *note PyTypeObject: 2d6. represents the Python Unicode type. It is exposed to Python code as ‘str’. The following APIs are really C macros and can be used to do fast checks and to access internal read-only data of Unicode objects: -- C Function: int PyUnicode_Check (PyObject *o) Return true if the object `o' is a Unicode object or an instance of a Unicode subtype. -- C Function: int PyUnicode_CheckExact (PyObject *o) Return true if the object `o' is a Unicode object, but not an instance of a subtype. -- C Function: int PyUnicode_READY (PyObject *o) Ensure the string object `o' is in the “canonical” representation. This is required before using any of the access macros described below. Returns ‘0’ on success and ‘-1’ with an exception set on failure, which in particular happens if memory allocation fails. New in version 3.3. Deprecated since version 3.10, will be removed in version 3.12: This API will be removed with *note PyUnicode_FromUnicode(): aef. -- C Function: Py_ssize_t PyUnicode_GET_LENGTH (PyObject *o) Return the length of the Unicode string, in code points. `o' has to be a Unicode object in the “canonical” representation (not checked). New in version 3.3. -- C Function: Py_UCS1* PyUnicode_1BYTE_DATA (PyObject *o) -- C Function: Py_UCS2* PyUnicode_2BYTE_DATA (PyObject *o) -- C Function: Py_UCS4* PyUnicode_4BYTE_DATA (PyObject *o) Return a pointer to the canonical representation cast to UCS1, UCS2 or UCS4 integer types for direct character access. No checks are performed if the canonical representation has the correct character size; use *note PyUnicode_KIND(): ade. to select the right macro. Make sure *note PyUnicode_READY(): ad6. has been called before accessing this. New in version 3.3. -- C Macro: PyUnicode_WCHAR_KIND -- C Macro: PyUnicode_1BYTE_KIND -- C Macro: PyUnicode_2BYTE_KIND -- C Macro: PyUnicode_4BYTE_KIND Return values of the *note PyUnicode_KIND(): ade. macro. New in version 3.3. Deprecated since version 3.10, will be removed in version 3.12: ‘PyUnicode_WCHAR_KIND’ is deprecated. -- C Function: int PyUnicode_KIND (PyObject *o) Return one of the PyUnicode kind constants (see above) that indicate how many bytes per character this Unicode object uses to store its data. `o' has to be a Unicode object in the “canonical” representation (not checked). New in version 3.3. -- C Function: void* PyUnicode_DATA (PyObject *o) Return a void pointer to the raw Unicode buffer. `o' has to be a Unicode object in the “canonical” representation (not checked). New in version 3.3. -- C Function: void PyUnicode_WRITE (int kind, void *data, Py_ssize_t index, Py_UCS4 value) Write into a canonical representation `data' (as obtained with *note PyUnicode_DATA(): ada.). This macro does not do any sanity checks and is intended for usage in loops. The caller should cache the `kind' value and `data' pointer as obtained from other macro calls. `index' is the index in the string (starts at 0) and `value' is the new code point value which should be written to that location. New in version 3.3. -- C Function: Py_UCS4 PyUnicode_READ (int kind, void *data, Py_ssize_t index) Read a code point from a canonical representation `data' (as obtained with *note PyUnicode_DATA(): ada.). No checks or ready calls are performed. New in version 3.3. -- C Function: Py_UCS4 PyUnicode_READ_CHAR (PyObject *o, Py_ssize_t index) Read a character from a Unicode object `o', which must be in the “canonical” representation. This is less efficient than *note PyUnicode_READ(): ae3. if you do multiple consecutive reads. New in version 3.3. -- C Macro: PyUnicode_MAX_CHAR_VALUE (o) Return the maximum code point that is suitable for creating another string based on `o', which must be in the “canonical” representation. This is always an approximation but more efficient than iterating over the string. New in version 3.3. -- C Function: int PyUnicode_ClearFreeList () Clear the free list. Return the total number of freed items. -- C Function: Py_ssize_t PyUnicode_GET_SIZE (PyObject *o) Return the size of the deprecated *note Py_UNICODE: aee. representation, in code units (this includes surrogate pairs as 2 units). `o' has to be a Unicode object (not checked). Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_GET_LENGTH(): acc. -- C Function: Py_ssize_t PyUnicode_GET_DATA_SIZE (PyObject *o) Return the size of the deprecated *note Py_UNICODE: aee. representation in bytes. `o' has to be a Unicode object (not checked). Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_GET_LENGTH(): acc. -- C Function: Py_UNICODE* PyUnicode_AS_UNICODE (PyObject *o) -- C Function: const char* PyUnicode_AS_DATA (PyObject *o) Return a pointer to a *note Py_UNICODE: aee. representation of the object. The returned buffer is always terminated with an extra null code point. It may also contain embedded null code points, which would cause the string to be truncated when used in most C functions. The ‘AS_DATA’ form casts the pointer to ‘const char *’. The `o' argument has to be a Unicode object (not checked). Changed in version 3.3: This macro is now inefficient – because in many cases the *note Py_UNICODE: aee. representation does not exist and needs to be created – and can fail (return ‘NULL’ with an exception set). Try to port the code to use the new ‘PyUnicode_nBYTE_DATA()’ macros or use *note PyUnicode_WRITE(): ae5. or *note PyUnicode_READ(): ae3. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using the ‘PyUnicode_nBYTE_DATA()’ family of macros.  File: python.info, Node: Unicode Character Properties, Next: Creating and accessing Unicode strings, Prev: Unicode Type, Up: Unicode Objects 7.8.3.9 Unicode Character Properties .................................... Unicode provides many different character properties. The most often needed ones are available through these macros which are mapped to C functions depending on the Python configuration. -- C Function: int Py_UNICODE_ISSPACE (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a whitespace character. -- C Function: int Py_UNICODE_ISLOWER (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a lowercase character. -- C Function: int Py_UNICODE_ISUPPER (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is an uppercase character. -- C Function: int Py_UNICODE_ISTITLE (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a titlecase character. -- C Function: int Py_UNICODE_ISLINEBREAK (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a linebreak character. -- C Function: int Py_UNICODE_ISDECIMAL (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a decimal character. -- C Function: int Py_UNICODE_ISDIGIT (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a digit character. -- C Function: int Py_UNICODE_ISNUMERIC (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a numeric character. -- C Function: int Py_UNICODE_ISALPHA (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is an alphabetic character. -- C Function: int Py_UNICODE_ISALNUM (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is an alphanumeric character. -- C Function: int Py_UNICODE_ISPRINTABLE (Py_UNICODE ch) Return ‘1’ or ‘0’ depending on whether `ch' is a printable character. Nonprintable characters are those characters defined in the Unicode character database as “Other” or “Separator”, excepting the ASCII space (0x20) which is considered printable. (Note that printable characters in this context are those which should not be escaped when *note repr(): 7cc. is invoked on a string. It has no bearing on the handling of strings written to *note sys.stdout: 30e. or *note sys.stderr: 30f.) These APIs can be used for fast direct character conversions: -- C Function: Py_UNICODE Py_UNICODE_TOLOWER (Py_UNICODE ch) Return the character `ch' converted to lower case. Deprecated since version 3.3: This function uses simple case mappings. -- C Function: Py_UNICODE Py_UNICODE_TOUPPER (Py_UNICODE ch) Return the character `ch' converted to upper case. Deprecated since version 3.3: This function uses simple case mappings. -- C Function: Py_UNICODE Py_UNICODE_TOTITLE (Py_UNICODE ch) Return the character `ch' converted to title case. Deprecated since version 3.3: This function uses simple case mappings. -- C Function: int Py_UNICODE_TODECIMAL (Py_UNICODE ch) Return the character `ch' converted to a decimal positive integer. Return ‘-1’ if this is not possible. This macro does not raise exceptions. -- C Function: int Py_UNICODE_TODIGIT (Py_UNICODE ch) Return the character `ch' converted to a single digit integer. Return ‘-1’ if this is not possible. This macro does not raise exceptions. -- C Function: double Py_UNICODE_TONUMERIC (Py_UNICODE ch) Return the character `ch' converted to a double. Return ‘-1.0’ if this is not possible. This macro does not raise exceptions. These APIs can be used to work with surrogates: -- C Macro: Py_UNICODE_IS_SURROGATE (ch) Check if `ch' is a surrogate (‘0xD800 <= ch <= 0xDFFF’). -- C Macro: Py_UNICODE_IS_HIGH_SURROGATE (ch) Check if `ch' is a high surrogate (‘0xD800 <= ch <= 0xDBFF’). -- C Macro: Py_UNICODE_IS_LOW_SURROGATE (ch) Check if `ch' is a low surrogate (‘0xDC00 <= ch <= 0xDFFF’). -- C Macro: Py_UNICODE_JOIN_SURROGATES (high, low) Join two surrogate characters and return a single Py_UCS4 value. `high' and `low' are respectively the leading and trailing surrogates in a surrogate pair.  File: python.info, Node: Creating and accessing Unicode strings, Next: Deprecated Py_UNICODE APIs, Prev: Unicode Character Properties, Up: Unicode Objects 7.8.3.10 Creating and accessing Unicode strings ............................................... To create Unicode objects and access their basic sequence properties, use these APIs: -- C Function: PyObject* PyUnicode_New (Py_ssize_t size, Py_UCS4 maxchar) `Return value: New reference.' Create a new Unicode object. `maxchar' should be the true maximum code point to be placed in the string. As an approximation, it can be rounded up to the nearest value in the sequence 127, 255, 65535, 1114111. This is the recommended way to allocate a new Unicode object. Objects created using this function are not resizable. New in version 3.3. -- C Function: PyObject* PyUnicode_FromKindAndData (int kind, const void *buffer, Py_ssize_t size) `Return value: New reference.' Create a new Unicode object with the given `kind' (possible values are *note PyUnicode_1BYTE_KIND: ae0. etc., as returned by *note PyUnicode_KIND(): ade.). The `buffer' must point to an array of `size' units of 1, 2 or 4 bytes per character, as given by the kind. New in version 3.3. -- C Function: PyObject* PyUnicode_FromStringAndSize (const char *u, Py_ssize_t size) `Return value: New reference.' Create a Unicode object from the char buffer `u'. The bytes will be interpreted as being UTF-8 encoded. The buffer is copied into the new object. If the buffer is not ‘NULL’, the return value might be a shared object, i.e. modification of the data is not allowed. If `u' is ‘NULL’, this function behaves like *note PyUnicode_FromUnicode(): aef. with the buffer set to ‘NULL’. This usage is deprecated in favor of *note PyUnicode_New(): acd, and will be removed in Python 3.12. -- C Function: PyObject *PyUnicode_FromString (const char *u) `Return value: New reference.' Create a Unicode object from a UTF-8 encoded null-terminated char buffer `u'. -- C Function: PyObject* PyUnicode_FromFormat (const char *format, ...) `Return value: New reference.' Take a C ‘printf()’-style `format' string and a variable number of arguments, calculate the size of the resulting Python Unicode string and return a string with the values formatted into it. The variable arguments must be C types and must correspond exactly to the format characters in the `format' ASCII-encoded string. The following format characters are allowed: Format Characters Type Comment ----------------------------------------------------------------------------------------- ‘%%’ `n/a' The literal % character. ‘%c’ int A single character, represented as a C int. ‘%d’ int Equivalent to ‘printf("%d")’. (1) ‘%u’ unsigned int Equivalent to ‘printf("%u")’. (2) ‘%ld’ long Equivalent to ‘printf("%ld")’. (3) ‘%li’ long Equivalent to ‘printf("%li")’. (4) ‘%lu’ unsigned long Equivalent to ‘printf("%lu")’. (5) ‘%lld’ long long Equivalent to ‘printf("%lld")’. (6) ‘%lli’ long long Equivalent to ‘printf("%lli")’. (7) ‘%llu’ unsigned long long Equivalent to ‘printf("%llu")’. (8) ‘%zd’ Py_ssize_t Equivalent to ‘printf("%zd")’. (9) ‘%zi’ Py_ssize_t Equivalent to ‘printf("%zi")’. (10) ‘%zu’ size_t Equivalent to ‘printf("%zu")’. (11) ‘%i’ int Equivalent to ‘printf("%i")’. (12) ‘%x’ int Equivalent to ‘printf("%x")’. (13) ‘%s’ const char* A null-terminated C character array. ‘%p’ const void* The hex representation of a C pointer. Mostly equivalent to ‘printf("%p")’ except that it is guaranteed to start with the literal ‘0x’ regardless of what the platform’s ‘printf’ yields. ‘%A’ PyObject* The result of calling *note ascii(): d4c. ‘%U’ PyObject* A Unicode object. ‘%V’ PyObject*, const char* A Unicode object (which may be ‘NULL’) and a null-terminated C character array as a second parameter (which will be used, if the first parameter is ‘NULL’). ‘%S’ PyObject* The result of calling *note PyObject_Str(): 969. ‘%R’ PyObject* The result of calling *note PyObject_Repr(): 968. An unrecognized format character causes all the rest of the format string to be copied as-is to the result string, and any extra arguments discarded. Note: The width formatter unit is number of characters rather than bytes. The precision formatter unit is number of bytes for ‘"%s"’ and ‘"%V"’ (if the ‘PyObject*’ argument is ‘NULL’), and a number of characters for ‘"%A"’, ‘"%U"’, ‘"%S"’, ‘"%R"’ and ‘"%V"’ (if the ‘PyObject*’ argument is not ‘NULL’). Changed in version 3.2: Support for ‘"%lld"’ and ‘"%llu"’ added. Changed in version 3.3: Support for ‘"%li"’, ‘"%lli"’ and ‘"%zi"’ added. Changed in version 3.4: Support width and precision formatter for ‘"%s"’, ‘"%A"’, ‘"%U"’, ‘"%V"’, ‘"%S"’, ‘"%R"’ added. -- C Function: PyObject* PyUnicode_FromFormatV (const char *format, va_list vargs) `Return value: New reference.' Identical to *note PyUnicode_FromFormat(): 7cb. except that it takes exactly two arguments. -- C Function: PyObject* PyUnicode_FromEncodedObject (PyObject *obj, const char *encoding, const char *errors) `Return value: New reference.' Decode an encoded object `obj' to a Unicode object. *note bytes: 331, *note bytearray: 332. and other *note bytes-like objects: 5e8. are decoded according to the given `encoding' and using the error handling defined by `errors'. Both can be ‘NULL’ to have the interface use the default values (see *note Built-in Codecs: 3b5a. for details). All other objects, including Unicode objects, cause a *note TypeError: 192. to be set. The API returns ‘NULL’ if there was an error. The caller is responsible for decref’ing the returned objects. -- C Function: Py_ssize_t PyUnicode_GetLength (PyObject *unicode) Return the length of the Unicode object, in code points. New in version 3.3. -- C Function: Py_ssize_t PyUnicode_CopyCharacters (PyObject *to, Py_ssize_t to_start, PyObject *from, Py_ssize_t from_start, Py_ssize_t how_many) Copy characters from one Unicode object into another. This function performs character conversion when necessary and falls back to ‘memcpy()’ if possible. Returns ‘-1’ and sets an exception on error, otherwise returns the number of copied characters. New in version 3.3. -- C Function: Py_ssize_t PyUnicode_Fill (PyObject *unicode, Py_ssize_t start, Py_ssize_t length, Py_UCS4 fill_char) Fill a string with a character: write `fill_char' into ‘unicode[start:start+length]’. Fail if `fill_char' is bigger than the string maximum character, or if the string has more than 1 reference. Return the number of written character, or return ‘-1’ and raise an exception on error. New in version 3.3. -- C Function: int PyUnicode_WriteChar (PyObject *unicode, Py_ssize_t index, Py_UCS4 character) Write a character to a string. The string must have been created through *note PyUnicode_New(): acd. Since Unicode strings are supposed to be immutable, the string must not be shared, or have been hashed yet. This function checks that `unicode' is a Unicode object, that the index is not out of bounds, and that the object can be modified safely (i.e. that it its reference count is one). New in version 3.3. -- C Function: Py_UCS4 PyUnicode_ReadChar (PyObject *unicode, Py_ssize_t index) Read a character from a string. This function checks that `unicode' is a Unicode object and the index is not out of bounds, in contrast to the macro version *note PyUnicode_READ_CHAR(): ae4. New in version 3.3. -- C Function: PyObject* PyUnicode_Substring (PyObject *str, Py_ssize_t start, Py_ssize_t end) `Return value: New reference.' Return a substring of `str', from character index `start' (included) to character index `end' (excluded). Negative indices are not supported. New in version 3.3. -- C Function: Py_UCS4* PyUnicode_AsUCS4 (PyObject *u, Py_UCS4 *buffer, Py_ssize_t buflen, int copy_null) Copy the string `u' into a UCS4 buffer, including a null character, if `copy_null' is set. Returns ‘NULL’ and sets an exception on error (in particular, a *note SystemError: 5fb. if `buflen' is smaller than the length of `u'). `buffer' is returned on success. New in version 3.3. -- C Function: Py_UCS4* PyUnicode_AsUCS4Copy (PyObject *u) Copy the string `u' into a new UCS4 buffer that is allocated using *note PyMem_Malloc(): 505. If this fails, ‘NULL’ is returned with a *note MemoryError: 13af. set. The returned buffer always has an extra null code point appended. New in version 3.3. ---------- Footnotes ---------- (1) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (2) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (3) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (4) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (5) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (6) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (7) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (8) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (9) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (10) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (11) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (12) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given. (13) (1) For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd, zi, zu, i, x): the 0-conversion flag has effect even when a precision is given.  File: python.info, Node: Deprecated Py_UNICODE APIs, Next: Locale Encoding, Prev: Creating and accessing Unicode strings, Up: Unicode Objects 7.8.3.11 Deprecated Py_UNICODE APIs ................................... Deprecated since version 3.3, will be removed in version 3.12. These API functions are deprecated with the implementation of PEP 393(1). Extension modules can continue using them, as they will not be removed in Python 3.x, but need to be aware that their use can now cause performance and memory hits. -- C Function: PyObject* PyUnicode_FromUnicode (const Py_UNICODE *u, Py_ssize_t size) `Return value: New reference.' Create a Unicode object from the Py_UNICODE buffer `u' of the given size. `u' may be ‘NULL’ which causes the contents to be undefined. It is the user’s responsibility to fill in the needed data. The buffer is copied into the new object. If the buffer is not ‘NULL’, the return value might be a shared object. Therefore, modification of the resulting Unicode object is only allowed when `u' is ‘NULL’. If the buffer is ‘NULL’, *note PyUnicode_READY(): ad6. must be called once the string content has been filled before using any of the access macros such as *note PyUnicode_KIND(): ade. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_FromKindAndData(): ad7, *note PyUnicode_FromWideChar(): af0, or *note PyUnicode_New(): acd. -- C Function: Py_UNICODE* PyUnicode_AsUnicode (PyObject *unicode) Return a read-only pointer to the Unicode object’s internal *note Py_UNICODE: aee. buffer, or ‘NULL’ on error. This will create the *note Py_UNICODE*: aee. representation of the object if it is not yet available. The buffer is always terminated with an extra null code point. Note that the resulting *note Py_UNICODE: aee. string may also contain embedded null code points, which would cause the string to be truncated when used in most C functions. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_AsUCS4(): ad8, *note PyUnicode_AsWideChar(): 3b5c, *note PyUnicode_ReadChar(): acf. or similar new APIs. Deprecated since version 3.3, will be removed in version 3.10. -- C Function: PyObject* PyUnicode_TransformDecimalToASCII (Py_UNICODE *s, Py_ssize_t size) `Return value: New reference.' Create a Unicode object by replacing all decimal digits in *note Py_UNICODE: aee. buffer of the given `size' by ASCII digits 0–9 according to their decimal value. Return ‘NULL’ if an exception occurs. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note Py_UNICODE_TODECIMAL(): 3b50. -- C Function: Py_UNICODE* PyUnicode_AsUnicodeAndSize (PyObject *unicode, Py_ssize_t *size) Like *note PyUnicode_AsUnicode(): af2, but also saves the *note Py_UNICODE(): aee. array length (excluding the extra null terminator) in `size'. Note that the resulting *note Py_UNICODE*: aee. string may contain embedded null code points, which would cause the string to be truncated when used in most C functions. New in version 3.3. Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_AsUCS4(): ad8, *note PyUnicode_AsWideChar(): 3b5c, *note PyUnicode_ReadChar(): acf. or similar new APIs. -- C Function: Py_UNICODE* PyUnicode_AsUnicodeCopy (PyObject *unicode) Create a copy of a Unicode string ending with a null code point. Return ‘NULL’ and raise a *note MemoryError: 13af. exception on memory allocation failure, otherwise return a new allocated buffer (use *note PyMem_Free(): da9. to free the buffer). Note that the resulting *note Py_UNICODE*: aee. string may contain embedded null code points, which would cause the string to be truncated when used in most C functions. New in version 3.2. Please migrate to using *note PyUnicode_AsUCS4Copy(): ad9. or similar new APIs. -- C Function: Py_ssize_t PyUnicode_GetSize (PyObject *unicode) Return the size of the deprecated *note Py_UNICODE: aee. representation, in code units (this includes surrogate pairs as 2 units). Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Unicode API, please migrate to using *note PyUnicode_GET_LENGTH(): acc. -- C Function: PyObject* PyUnicode_FromObject (PyObject *obj) `Return value: New reference.' Copy an instance of a Unicode subtype to a new true Unicode object if necessary. If `obj' is already a true Unicode object (not a subtype), return the reference with incremented refcount. Objects other than Unicode or its subtypes will cause a *note TypeError: 192. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0393  File: python.info, Node: Locale Encoding, Next: File System Encoding, Prev: Deprecated Py_UNICODE APIs, Up: Unicode Objects 7.8.3.12 Locale Encoding ........................ The current locale encoding can be used to decode text from the operating system. -- C Function: PyObject* PyUnicode_DecodeLocaleAndSize (const char *str, Py_ssize_t len, const char *errors) `Return value: New reference.' Decode a string from UTF-8 on Android and VxWorks, or from the current locale encoding on other platforms. The supported error handlers are ‘"strict"’ and ‘"surrogateescape"’ ( PEP 383(1)). The decoder uses ‘"strict"’ error handler if `errors' is ‘NULL’. `str' must end with a null character but cannot contain embedded null characters. Use *note PyUnicode_DecodeFSDefaultAndSize(): 3990. to decode a string from ‘Py_FileSystemDefaultEncoding’ (the locale encoding read at Python startup). This function ignores the Python UTF-8 mode. See also ........ The *note Py_DecodeLocale(): 43c. function. New in version 3.3. Changed in version 3.7: The function now also uses the current locale encoding for the ‘surrogateescape’ error handler, except on Android. Previously, *note Py_DecodeLocale(): 43c. was used for the ‘surrogateescape’, and the current locale encoding was used for ‘strict’. -- C Function: PyObject* PyUnicode_DecodeLocale (const char *str, const char *errors) `Return value: New reference.' Similar to *note PyUnicode_DecodeLocaleAndSize(): 43e, but compute the string length using ‘strlen()’. New in version 3.3. -- C Function: PyObject* PyUnicode_EncodeLocale (PyObject *unicode, const char *errors) `Return value: New reference.' Encode a Unicode object to UTF-8 on Android and VxWorks, or to the current locale encoding on other platforms. The supported error handlers are ‘"strict"’ and ‘"surrogateescape"’ ( PEP 383(2)). The encoder uses ‘"strict"’ error handler if `errors' is ‘NULL’. Return a *note bytes: 331. object. `unicode' cannot contain embedded null characters. Use *note PyUnicode_EncodeFSDefault(): 3991. to encode a string to ‘Py_FileSystemDefaultEncoding’ (the locale encoding read at Python startup). This function ignores the Python UTF-8 mode. See also ........ The *note Py_EncodeLocale(): 43d. function. New in version 3.3. Changed in version 3.7: The function now also uses the current locale encoding for the ‘surrogateescape’ error handler, except on Android. Previously, *note Py_EncodeLocale(): 43d. was used for the ‘surrogateescape’, and the current locale encoding was used for ‘strict’. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0383 (2) https://www.python.org/dev/peps/pep-0383  File: python.info, Node: File System Encoding, Next: wchar_t Support, Prev: Locale Encoding, Up: Unicode Objects 7.8.3.13 File System Encoding ............................. To encode and decode file names and other environment strings, ‘Py_FileSystemDefaultEncoding’ should be used as the encoding, and ‘Py_FileSystemDefaultEncodeErrors’ should be used as the error handler ( PEP 383(1) and PEP 529(2)). To encode file names to *note bytes: 331. during argument parsing, the ‘"O&"’ converter should be used, passing *note PyUnicode_FSConverter(): 5ce. as the conversion function: -- C Function: int PyUnicode_FSConverter (PyObject* obj, void* result) ParseTuple converter: encode *note str: 330. objects – obtained directly or through the *note os.PathLike: 4eb. interface – to *note bytes: 331. using *note PyUnicode_EncodeFSDefault(): 3991.; *note bytes: 331. objects are output as-is. `result' must be a *note PyBytesObject*: d1e. which must be released when it is no longer used. New in version 3.1. Changed in version 3.6: Accepts a *note path-like object: 36a. To decode file names to *note str: 330. during argument parsing, the ‘"O&"’ converter should be used, passing *note PyUnicode_FSDecoder(): 5cf. as the conversion function: -- C Function: int PyUnicode_FSDecoder (PyObject* obj, void* result) ParseTuple converter: decode *note bytes: 331. objects – obtained either directly or indirectly through the *note os.PathLike: 4eb. interface – to *note str: 330. using *note PyUnicode_DecodeFSDefaultAndSize(): 3990.; *note str: 330. objects are output as-is. `result' must be a *note PyUnicodeObject*: 3b3c. which must be released when it is no longer used. New in version 3.2. Changed in version 3.6: Accepts a *note path-like object: 36a. -- C Function: PyObject* PyUnicode_DecodeFSDefaultAndSize (const char *s, Py_ssize_t size) `Return value: New reference.' Decode a string using ‘Py_FileSystemDefaultEncoding’ and the ‘Py_FileSystemDefaultEncodeErrors’ error handler. If ‘Py_FileSystemDefaultEncoding’ is not set, fall back to the locale encoding. ‘Py_FileSystemDefaultEncoding’ is initialized at startup from the locale encoding and cannot be modified later. If you need to decode a string from the current locale encoding, use *note PyUnicode_DecodeLocaleAndSize(): 43e. See also ........ The *note Py_DecodeLocale(): 43c. function. Changed in version 3.6: Use ‘Py_FileSystemDefaultEncodeErrors’ error handler. -- C Function: PyObject* PyUnicode_DecodeFSDefault (const char *s) `Return value: New reference.' Decode a null-terminated string using ‘Py_FileSystemDefaultEncoding’ and the ‘Py_FileSystemDefaultEncodeErrors’ error handler. If ‘Py_FileSystemDefaultEncoding’ is not set, fall back to the locale encoding. Use *note PyUnicode_DecodeFSDefaultAndSize(): 3990. if you know the string length. Changed in version 3.6: Use ‘Py_FileSystemDefaultEncodeErrors’ error handler. -- C Function: PyObject* PyUnicode_EncodeFSDefault (PyObject *unicode) `Return value: New reference.' Encode a Unicode object to ‘Py_FileSystemDefaultEncoding’ with the ‘Py_FileSystemDefaultEncodeErrors’ error handler, and return *note bytes: 331. Note that the resulting *note bytes: 331. object may contain null bytes. If ‘Py_FileSystemDefaultEncoding’ is not set, fall back to the locale encoding. ‘Py_FileSystemDefaultEncoding’ is initialized at startup from the locale encoding and cannot be modified later. If you need to encode a string to the current locale encoding, use *note PyUnicode_EncodeLocale(): 43f. See also ........ The *note Py_EncodeLocale(): 43d. function. New in version 3.2. Changed in version 3.6: Use ‘Py_FileSystemDefaultEncodeErrors’ error handler. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0383 (2) https://www.python.org/dev/peps/pep-0529  File: python.info, Node: wchar_t Support, Prev: File System Encoding, Up: Unicode Objects 7.8.3.14 wchar_t Support ........................ ‘wchar_t’ support for platforms which support it: -- C Function: PyObject* PyUnicode_FromWideChar (const wchar_t *w, Py_ssize_t size) `Return value: New reference.' Create a Unicode object from the ‘wchar_t’ buffer `w' of the given `size'. Passing ‘-1’ as the `size' indicates that the function must itself compute the length, using wcslen. Return ‘NULL’ on failure. -- C Function: Py_ssize_t PyUnicode_AsWideChar (PyObject *unicode, wchar_t *w, Py_ssize_t size) Copy the Unicode object contents into the ‘wchar_t’ buffer `w'. At most `size' ‘wchar_t’ characters are copied (excluding a possibly trailing null termination character). Return the number of ‘wchar_t’ characters copied or ‘-1’ in case of an error. Note that the resulting ‘wchar_t*’ string may or may not be null-terminated. It is the responsibility of the caller to make sure that the ‘wchar_t*’ string is null-terminated in case this is required by the application. Also, note that the ‘wchar_t*’ string might contain null characters, which would cause the string to be truncated when used with most C functions. -- C Function: wchar_t* PyUnicode_AsWideCharString (PyObject *unicode, Py_ssize_t *size) Convert the Unicode object to a wide character string. The output string always ends with a null character. If `size' is not ‘NULL’, write the number of wide characters (excluding the trailing null termination character) into `*size'. Note that the resulting ‘wchar_t’ string might contain null characters, which would cause the string to be truncated when used with most C functions. If `size' is ‘NULL’ and the ‘wchar_t*’ string contains null characters a *note ValueError: 1fb. is raised. Returns a buffer allocated by ‘PyMem_Alloc()’ (use *note PyMem_Free(): da9. to free it) on success. On error, returns ‘NULL’ and `*size' is undefined. Raises a *note MemoryError: 13af. if memory allocation is failed. New in version 3.2. Changed in version 3.7: Raises a *note ValueError: 1fb. if `size' is ‘NULL’ and the ‘wchar_t*’ string contains null characters.  File: python.info, Node: Built-in Codecs, Next: Methods and Slot Functions, Prev: Unicode Objects, Up: Unicode Objects and Codecs 7.8.3.15 Built-in Codecs ........................ Python provides a set of built-in codecs which are written in C for speed. All of these codecs are directly usable via the following functions. Many of the following APIs take two arguments encoding and errors, and they have the same semantics as the ones of the built-in *note str(): 330. string object constructor. Setting encoding to ‘NULL’ causes the default encoding to be used which is ASCII. The file system calls should use *note PyUnicode_FSConverter(): 5ce. for encoding file names. This uses the variable ‘Py_FileSystemDefaultEncoding’ internally. This variable should be treated as read-only: on some systems, it will be a pointer to a static string, on others, it will change at run-time (such as when the application invokes setlocale). Error handling is set by errors which may also be set to ‘NULL’ meaning to use the default handling defined for the codec. Default error handling for all built-in codecs is “strict” (*note ValueError: 1fb. is raised). The codecs all use a similar interface. Only deviation from the following generic ones are documented for simplicity. * Menu: * Generic Codecs:: * UTF-8 Codecs:: * UTF-32 Codecs:: * UTF-16 Codecs:: * UTF-7 Codecs:: * Unicode-Escape Codecs:: * Raw-Unicode-Escape Codecs:: * Latin-1 Codecs:: * ASCII Codecs:: * Character Map Codecs:: * MBCS codecs for Windows:: * Methods & Slots::  File: python.info, Node: Generic Codecs, Next: UTF-8 Codecs, Up: Built-in Codecs 7.8.3.16 Generic Codecs ....................... These are the generic codec APIs: -- C Function: PyObject* PyUnicode_Decode (const char *s, Py_ssize_t size, const char *encoding, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the encoded string `s'. `encoding' and `errors' have the same meaning as the parameters of the same name in the *note str(): 330. built-in function. The codec to be used is looked up using the Python codec registry. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_AsEncodedString (PyObject *unicode, const char *encoding, const char *errors) `Return value: New reference.' Encode a Unicode object and return the result as Python bytes object. `encoding' and `errors' have the same meaning as the parameters of the same name in the Unicode *note encode(): c37. method. The codec to be used is looked up using the Python codec registry. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_Encode (const Py_UNICODE *s, Py_ssize_t size, const char *encoding, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer `s' of the given `size' and return a Python bytes object. `encoding' and `errors' have the same meaning as the parameters of the same name in the Unicode *note encode(): c37. method. The codec to be used is looked up using the Python codec registry. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: UTF-8 Codecs, Next: UTF-32 Codecs, Prev: Generic Codecs, Up: Built-in Codecs 7.8.3.17 UTF-8 Codecs ..................... These are the UTF-8 codec APIs: -- C Function: PyObject* PyUnicode_DecodeUTF8 (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the UTF-8 encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_DecodeUTF8Stateful (const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed) `Return value: New reference.' If `consumed' is ‘NULL’, behave like *note PyUnicode_DecodeUTF8(): 3b68. If `consumed' is not ‘NULL’, trailing incomplete UTF-8 byte sequences will not be treated as an error. Those bytes will not be decoded and the number of bytes that have been decoded will be stored in `consumed'. -- C Function: PyObject* PyUnicode_AsUTF8String (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using UTF-8 and return the result as Python bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: const char* PyUnicode_AsUTF8AndSize (PyObject *unicode, Py_ssize_t *size) Return a pointer to the UTF-8 encoding of the Unicode object, and store the size of the encoded representation (in bytes) in `size'. The `size' argument can be ‘NULL’; in this case no size will be stored. The returned buffer always has an extra null byte appended (not included in `size'), regardless of whether there are any other null code points. In the case of an error, ‘NULL’ is returned with an exception set and no `size' is stored. This caches the UTF-8 representation of the string in the Unicode object, and subsequent calls will return a pointer to the same buffer. The caller is not responsible for deallocating the buffer. New in version 3.3. Changed in version 3.7: The return type is now ‘const char *’ rather of ‘char *’. -- C Function: const char* PyUnicode_AsUTF8 (PyObject *unicode) As *note PyUnicode_AsUTF8AndSize(): 42a, but does not store the size. New in version 3.3. Changed in version 3.7: The return type is now ‘const char *’ rather of ‘char *’. -- C Function: PyObject* PyUnicode_EncodeUTF8 (const Py_UNICODE *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer `s' of the given `size' using UTF-8 and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsUTF8String(): aff, *note PyUnicode_AsUTF8AndSize(): 42a. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: UTF-32 Codecs, Next: UTF-16 Codecs, Prev: UTF-8 Codecs, Up: Built-in Codecs 7.8.3.18 UTF-32 Codecs ...................... These are the UTF-32 codec APIs: -- C Function: PyObject* PyUnicode_DecodeUTF32 (const char *s, Py_ssize_t size, const char *errors, int *byteorder) `Return value: New reference.' Decode `size' bytes from a UTF-32 encoded buffer string and return the corresponding Unicode object. `errors' (if non-‘NULL’) defines the error handling. It defaults to “strict”. If `byteorder' is non-‘NULL’, the decoder starts decoding using the given byte order: *byteorder == -1: little endian *byteorder == 0: native order *byteorder == 1: big endian If ‘*byteorder’ is zero, and the first four bytes of the input data are a byte order mark (BOM), the decoder switches to this byte order and the BOM is not copied into the resulting Unicode string. If ‘*byteorder’ is ‘-1’ or ‘1’, any byte order mark is copied to the output. After completion, `*byteorder' is set to the current byte order at the end of input data. If `byteorder' is ‘NULL’, the codec starts in native order mode. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_DecodeUTF32Stateful (const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed) `Return value: New reference.' If `consumed' is ‘NULL’, behave like *note PyUnicode_DecodeUTF32(): 3b6b. If `consumed' is not ‘NULL’, *note PyUnicode_DecodeUTF32Stateful(): 3b6c. will not treat trailing incomplete UTF-32 byte sequences (such as a number of bytes not divisible by four) as an error. Those bytes will not be decoded and the number of bytes that have been decoded will be stored in `consumed'. -- C Function: PyObject* PyUnicode_AsUTF32String (PyObject *unicode) `Return value: New reference.' Return a Python byte string using the UTF-32 encoding in native byte order. The string always starts with a BOM mark. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeUTF32 (const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder) `Return value: New reference.' Return a Python bytes object holding the UTF-32 encoded value of the Unicode data in `s'. Output is written according to the following byte order: byteorder == -1: little endian byteorder == 0: native byte order (writes a BOM mark) byteorder == 1: big endian If byteorder is ‘0’, the output string will always start with the Unicode BOM mark (U+FEFF). In the other two modes, no BOM mark is prepended. If ‘Py_UNICODE_WIDE’ is not defined, surrogate pairs will be output as a single code point. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsUTF32String(): 3b6d. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: UTF-16 Codecs, Next: UTF-7 Codecs, Prev: UTF-32 Codecs, Up: Built-in Codecs 7.8.3.19 UTF-16 Codecs ...................... These are the UTF-16 codec APIs: -- C Function: PyObject* PyUnicode_DecodeUTF16 (const char *s, Py_ssize_t size, const char *errors, int *byteorder) `Return value: New reference.' Decode `size' bytes from a UTF-16 encoded buffer string and return the corresponding Unicode object. `errors' (if non-‘NULL’) defines the error handling. It defaults to “strict”. If `byteorder' is non-‘NULL’, the decoder starts decoding using the given byte order: *byteorder == -1: little endian *byteorder == 0: native order *byteorder == 1: big endian If ‘*byteorder’ is zero, and the first two bytes of the input data are a byte order mark (BOM), the decoder switches to this byte order and the BOM is not copied into the resulting Unicode string. If ‘*byteorder’ is ‘-1’ or ‘1’, any byte order mark is copied to the output (where it will result in either a ‘\ufeff’ or a ‘\ufffe’ character). After completion, `*byteorder' is set to the current byte order at the end of input data. If `byteorder' is ‘NULL’, the codec starts in native order mode. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_DecodeUTF16Stateful (const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed) `Return value: New reference.' If `consumed' is ‘NULL’, behave like *note PyUnicode_DecodeUTF16(): 3b6f. If `consumed' is not ‘NULL’, *note PyUnicode_DecodeUTF16Stateful(): 3b70. will not treat trailing incomplete UTF-16 byte sequences (such as an odd number of bytes or a split surrogate pair) as an error. Those bytes will not be decoded and the number of bytes that have been decoded will be stored in `consumed'. -- C Function: PyObject* PyUnicode_AsUTF16String (PyObject *unicode) `Return value: New reference.' Return a Python byte string using the UTF-16 encoding in native byte order. The string always starts with a BOM mark. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeUTF16 (const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder) `Return value: New reference.' Return a Python bytes object holding the UTF-16 encoded value of the Unicode data in `s'. Output is written according to the following byte order: byteorder == -1: little endian byteorder == 0: native byte order (writes a BOM mark) byteorder == 1: big endian If byteorder is ‘0’, the output string will always start with the Unicode BOM mark (U+FEFF). In the other two modes, no BOM mark is prepended. If ‘Py_UNICODE_WIDE’ is defined, a single *note Py_UNICODE: aee. value may get represented as a surrogate pair. If it is not defined, each *note Py_UNICODE: aee. values is interpreted as a UCS-2 character. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsUTF16String(): 3b71. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: UTF-7 Codecs, Next: Unicode-Escape Codecs, Prev: UTF-16 Codecs, Up: Built-in Codecs 7.8.3.20 UTF-7 Codecs ..................... These are the UTF-7 codec APIs: -- C Function: PyObject* PyUnicode_DecodeUTF7 (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the UTF-7 encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_DecodeUTF7Stateful (const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed) `Return value: New reference.' If `consumed' is ‘NULL’, behave like *note PyUnicode_DecodeUTF7(): 3b73. If `consumed' is not ‘NULL’, trailing incomplete UTF-7 base-64 sections will not be treated as an error. Those bytes will not be decoded and the number of bytes that have been decoded will be stored in `consumed'. -- C Function: PyObject* PyUnicode_EncodeUTF7 (const Py_UNICODE *s, Py_ssize_t size, int base64SetO, int base64WhiteSpace, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given size using UTF-7 and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. If `base64SetO' is nonzero, “Set O” (punctuation that has no otherwise special meaning) will be encoded in base-64. If `base64WhiteSpace' is nonzero, whitespace will be encoded in base-64. Both are set to zero for the Python “utf-7” codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: Unicode-Escape Codecs, Next: Raw-Unicode-Escape Codecs, Prev: UTF-7 Codecs, Up: Built-in Codecs 7.8.3.21 Unicode-Escape Codecs .............................. These are the “Unicode Escape” codec APIs: -- C Function: PyObject* PyUnicode_DecodeUnicodeEscape (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the Unicode-Escape encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_AsUnicodeEscapeString (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using Unicode-Escape and return the result as a bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeUnicodeEscape (const Py_UNICODE *s, Py_ssize_t size) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using Unicode-Escape and return a bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsUnicodeEscapeString(): b03.  File: python.info, Node: Raw-Unicode-Escape Codecs, Next: Latin-1 Codecs, Prev: Unicode-Escape Codecs, Up: Built-in Codecs 7.8.3.22 Raw-Unicode-Escape Codecs .................................. These are the “Raw Unicode Escape” codec APIs: -- C Function: PyObject* PyUnicode_DecodeRawUnicodeEscape (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the Raw-Unicode-Escape encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_AsRawUnicodeEscapeString (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using Raw-Unicode-Escape and return the result as a bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeRawUnicodeEscape (const Py_UNICODE *s, Py_ssize_t size) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using Raw-Unicode-Escape and return a bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsRawUnicodeEscapeString(): b05. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: Latin-1 Codecs, Next: ASCII Codecs, Prev: Raw-Unicode-Escape Codecs, Up: Built-in Codecs 7.8.3.23 Latin-1 Codecs ....................... These are the Latin-1 codec APIs: Latin-1 corresponds to the first 256 Unicode ordinals and only these are accepted by the codecs during encoding. -- C Function: PyObject* PyUnicode_DecodeLatin1 (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the Latin-1 encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_AsLatin1String (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using Latin-1 and return the result as Python bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeLatin1 (const Py_UNICODE *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using Latin-1 and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsLatin1String(): b07. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: ASCII Codecs, Next: Character Map Codecs, Prev: Latin-1 Codecs, Up: Built-in Codecs 7.8.3.24 ASCII Codecs ..................... These are the ASCII codec APIs. Only 7-bit ASCII data is accepted. All other codes generate errors. -- C Function: PyObject* PyUnicode_DecodeASCII (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the ASCII encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_AsASCIIString (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using ASCII and return the result as Python bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeASCII (const Py_UNICODE *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using ASCII and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsASCIIString(): b09. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: Character Map Codecs, Next: MBCS codecs for Windows, Prev: ASCII Codecs, Up: Built-in Codecs 7.8.3.25 Character Map Codecs ............................. This codec is special in that it can be used to implement many different codecs (and this is in fact what was done to obtain most of the standard codecs included in the ‘encodings’ package). The codec uses mapping to encode and decode characters. The mapping objects provided must support the *note __getitem__(): 27c. mapping interface; dictionaries and sequences work well. These are the mapping codec APIs: -- C Function: PyObject* PyUnicode_DecodeCharmap (const char *data, Py_ssize_t size, PyObject *mapping, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the encoded string `s' using the given `mapping' object. Return ‘NULL’ if an exception was raised by the codec. If `mapping' is ‘NULL’, Latin-1 decoding will be applied. Else `mapping' must map bytes ordinals (integers in the range from 0 to 255) to Unicode strings, integers (which are then interpreted as Unicode ordinals) or ‘None’. Unmapped data bytes – ones which cause a *note LookupError: 1308, as well as ones which get mapped to ‘None’, ‘0xFFFE’ or ‘'\ufffe'’, are treated as undefined mappings and cause an error. -- C Function: PyObject* PyUnicode_AsCharmapString (PyObject *unicode, PyObject *mapping) `Return value: New reference.' Encode a Unicode object using the given `mapping' object and return the result as a bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. The `mapping' object must map Unicode ordinal integers to bytes objects, integers in the range from 0 to 255 or ‘None’. Unmapped character ordinals (ones which cause a *note LookupError: 1308.) as well as mapped to ‘None’ are treated as “undefined mapping” and cause an error. -- C Function: PyObject* PyUnicode_EncodeCharmap (const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using the given `mapping' object and return the result as a bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsCharmapString(): 3b7f. or *note PyUnicode_AsEncodedString(): 3b66. The following codec API is special in that maps Unicode to Unicode. -- C Function: PyObject* PyUnicode_Translate (PyObject *str, PyObject *table, const char *errors) `Return value: New reference.' Translate a string by applying a character mapping table to it and return the resulting Unicode object. Return ‘NULL’ if an exception was raised by the codec. The mapping table must map Unicode ordinal integers to Unicode ordinal integers or ‘None’ (causing deletion of the character). Mapping tables need only provide the *note __getitem__(): 27c. interface; dictionaries and sequences work well. Unmapped character ordinals (ones which cause a *note LookupError: 1308.) are left untouched and are copied as-is. `errors' has the usual meaning for codecs. It may be ‘NULL’ which indicates to use the default error handling. -- C Function: PyObject* PyUnicode_TranslateCharmap (const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors) `Return value: New reference.' Translate a *note Py_UNICODE: aee. buffer of the given `size' by applying a character `mapping' table to it and return the resulting Unicode object. Return ‘NULL’ when an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 3.11: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_Translate(): 3b80. or *note generic codec based API: 5ee.  File: python.info, Node: MBCS codecs for Windows, Next: Methods & Slots, Prev: Character Map Codecs, Up: Built-in Codecs 7.8.3.26 MBCS codecs for Windows ................................ These are the MBCS codec APIs. They are currently only available on Windows and use the Win32 MBCS converters to implement the conversions. Note that MBCS (or DBCS) is a class of encodings, not just one. The target encoding is defined by the user settings on the machine running the codec. -- C Function: PyObject* PyUnicode_DecodeMBCS (const char *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Create a Unicode object by decoding `size' bytes of the MBCS encoded string `s'. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_DecodeMBCSStateful (const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed) `Return value: New reference.' If `consumed' is ‘NULL’, behave like *note PyUnicode_DecodeMBCS(): 3b82. If `consumed' is not ‘NULL’, *note PyUnicode_DecodeMBCSStateful(): 3b83. will not decode trailing lead byte and the number of bytes that have been decoded will be stored in `consumed'. -- C Function: PyObject* PyUnicode_AsMBCSString (PyObject *unicode) `Return value: New reference.' Encode a Unicode object using MBCS and return the result as Python bytes object. Error handling is “strict”. Return ‘NULL’ if an exception was raised by the codec. -- C Function: PyObject* PyUnicode_EncodeCodePage (int code_page, PyObject *unicode, const char *errors) `Return value: New reference.' Encode the Unicode object using the specified code page and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. Use ‘CP_ACP’ code page to get the MBCS encoder. New in version 3.3. -- C Function: PyObject* PyUnicode_EncodeMBCS (const Py_UNICODE *s, Py_ssize_t size, const char *errors) `Return value: New reference.' Encode the *note Py_UNICODE: aee. buffer of the given `size' using MBCS and return a Python bytes object. Return ‘NULL’ if an exception was raised by the codec. Deprecated since version 3.3, will be removed in version 4.0: Part of the old-style *note Py_UNICODE: aee. API; please migrate to using *note PyUnicode_AsMBCSString(): b0d, *note PyUnicode_EncodeCodePage(): b0e. or *note PyUnicode_AsEncodedString(): 3b66.  File: python.info, Node: Methods & Slots, Prev: MBCS codecs for Windows, Up: Built-in Codecs 7.8.3.27 Methods & Slots ........................  File: python.info, Node: Methods and Slot Functions, Prev: Built-in Codecs, Up: Unicode Objects and Codecs 7.8.3.28 Methods and Slot Functions ................................... The following APIs are capable of handling Unicode objects and strings on input (we refer to them as strings in the descriptions) and return Unicode objects or integers as appropriate. They all return ‘NULL’ or ‘-1’ if an exception occurs. -- C Function: PyObject* PyUnicode_Concat (PyObject *left, PyObject *right) `Return value: New reference.' Concat two strings giving a new Unicode string. -- C Function: PyObject* PyUnicode_Split (PyObject *s, PyObject *sep, Py_ssize_t maxsplit) `Return value: New reference.' Split a string giving a list of Unicode strings. If `sep' is ‘NULL’, splitting will be done at all whitespace substrings. Otherwise, splits occur at the given separator. At most `maxsplit' splits will be done. If negative, no limit is set. Separators are not included in the resulting list. -- C Function: PyObject* PyUnicode_Splitlines (PyObject *s, int keepend) `Return value: New reference.' Split a Unicode string at line breaks, returning a list of Unicode strings. CRLF is considered to be one line break. If `keepend' is ‘0’, the Line break characters are not included in the resulting strings. -- C Function: PyObject* PyUnicode_Join (PyObject *separator, PyObject *seq) `Return value: New reference.' Join a sequence of strings using the given `separator' and return the resulting Unicode string. -- C Function: Py_ssize_t PyUnicode_Tailmatch (PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction) Return ‘1’ if `substr' matches ‘str[start:end]’ at the given tail end (`direction' == ‘-1’ means to do a prefix match, `direction' == ‘1’ a suffix match), ‘0’ otherwise. Return ‘-1’ if an error occurred. -- C Function: Py_ssize_t PyUnicode_Find (PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction) Return the first position of `substr' in ‘str[start:end]’ using the given `direction' (`direction' == ‘1’ means to do a forward search, `direction' == ‘-1’ a backward search). The return value is the index of the first match; a value of ‘-1’ indicates that no match was found, and ‘-2’ indicates that an error occurred and an exception has been set. -- C Function: Py_ssize_t PyUnicode_FindChar (PyObject *str, Py_UCS4 ch, Py_ssize_t start, Py_ssize_t end, int direction) Return the first position of the character `ch' in ‘str[start:end]’ using the given `direction' (`direction' == ‘1’ means to do a forward search, `direction' == ‘-1’ a backward search). The return value is the index of the first match; a value of ‘-1’ indicates that no match was found, and ‘-2’ indicates that an error occurred and an exception has been set. New in version 3.3. Changed in version 3.7: `start' and `end' are now adjusted to behave like ‘str[start:end]’. -- C Function: Py_ssize_t PyUnicode_Count (PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end) Return the number of non-overlapping occurrences of `substr' in ‘str[start:end]’. Return ‘-1’ if an error occurred. -- C Function: PyObject* PyUnicode_Replace (PyObject *str, PyObject *substr, PyObject *replstr, Py_ssize_t maxcount) `Return value: New reference.' Replace at most `maxcount' occurrences of `substr' in `str' with `replstr' and return the resulting Unicode object. `maxcount' == ‘-1’ means replace all occurrences. -- C Function: int PyUnicode_Compare (PyObject *left, PyObject *right) Compare two strings and return ‘-1’, ‘0’, ‘1’ for less than, equal, and greater than, respectively. This function returns ‘-1’ upon failure, so one should call *note PyErr_Occurred(): 383f. to check for errors. -- C Function: int PyUnicode_CompareWithASCIIString (PyObject *uni, const char *string) Compare a Unicode object, `uni', with `string' and return ‘-1’, ‘0’, ‘1’ for less than, equal, and greater than, respectively. It is best to pass only ASCII-encoded strings, but the function interprets the input string as ISO-8859-1 if it contains non-ASCII characters. This function does not raise exceptions. -- C Function: PyObject* PyUnicode_RichCompare (PyObject *left, PyObject *right, int op) `Return value: New reference.' Rich compare two Unicode strings and return one of the following: * ‘NULL’ in case an exception was raised * ‘Py_True’ or ‘Py_False’ for successful comparisons * ‘Py_NotImplemented’ in case the type combination is unknown Possible values for `op' are ‘Py_GT’, ‘Py_GE’, ‘Py_EQ’, ‘Py_NE’, ‘Py_LT’, and ‘Py_LE’. -- C Function: PyObject* PyUnicode_Format (PyObject *format, PyObject *args) `Return value: New reference.' Return a new string object from `format' and `args'; this is analogous to ‘format % args’. -- C Function: int PyUnicode_Contains (PyObject *container, PyObject *element) Check whether `element' is contained in `container' and return true or false accordingly. `element' has to coerce to a one element Unicode string. ‘-1’ is returned if there was an error. -- C Function: void PyUnicode_InternInPlace (PyObject **string) Intern the argument `*string' in place. The argument must be the address of a pointer variable pointing to a Python Unicode string object. If there is an existing interned string that is the same as `*string', it sets `*string' to it (decrementing the reference count of the old string object and incrementing the reference count of the interned string object), otherwise it leaves `*string' alone and interns it (incrementing its reference count). (Clarification: even though there is a lot of talk about reference counts, think of this function as reference-count-neutral; you own the object after the call if and only if you owned it before the call.) -- C Function: PyObject* PyUnicode_InternFromString (const char *v) `Return value: New reference.' A combination of *note PyUnicode_FromString(): 38d1. and *note PyUnicode_InternInPlace(): 3b8f, returning either a new Unicode string object that has been interned, or a new (“owned”) reference to an earlier interned string object with the same value.  File: python.info, Node: Tuple Objects, Next: Struct Sequence Objects, Prev: Unicode Objects and Codecs, Up: Sequence Objects 7.8.3.29 Tuple Objects ...................... -- C Type: PyTupleObject This subtype of *note PyObject: 4ba. represents a Python tuple object. -- C Variable: PyTypeObject PyTuple_Type This instance of *note PyTypeObject: 2d6. represents the Python tuple type; it is the same object as *note tuple: 47e. in the Python layer. -- C Function: int PyTuple_Check (PyObject *p) Return true if `p' is a tuple object or an instance of a subtype of the tuple type. -- C Function: int PyTuple_CheckExact (PyObject *p) Return true if `p' is a tuple object, but not an instance of a subtype of the tuple type. -- C Function: PyObject* PyTuple_New (Py_ssize_t len) `Return value: New reference.' Return a new tuple object of size `len', or ‘NULL’ on failure. -- C Function: PyObject* PyTuple_Pack (Py_ssize_t n, ...) `Return value: New reference.' Return a new tuple object of size `n', or ‘NULL’ on failure. The tuple values are initialized to the subsequent `n' C arguments pointing to Python objects. ‘PyTuple_Pack(2, a, b)’ is equivalent to ‘Py_BuildValue("(OO)", a, b)’. -- C Function: Py_ssize_t PyTuple_Size (PyObject *p) Take a pointer to a tuple object, and return the size of that tuple. -- C Function: Py_ssize_t PyTuple_GET_SIZE (PyObject *p) Return the size of the tuple `p', which must be non-‘NULL’ and point to a tuple; no error checking is performed. -- C Function: PyObject* PyTuple_GetItem (PyObject *p, Py_ssize_t pos) `Return value: Borrowed reference.' Return the object at position `pos' in the tuple pointed to by `p'. If `pos' is out of bounds, return ‘NULL’ and set an *note IndexError: e75. exception. -- C Function: PyObject* PyTuple_GET_ITEM (PyObject *p, Py_ssize_t pos) `Return value: Borrowed reference.' Like *note PyTuple_GetItem(): 385c, but does no checking of its arguments. -- C Function: PyObject* PyTuple_GetSlice (PyObject *p, Py_ssize_t low, Py_ssize_t high) `Return value: New reference.' Return the slice of the tuple pointed to by `p' between `low' and `high', or ‘NULL’ on failure. This is the equivalent of the Python expression ‘p[low:high]’. Indexing from the end of the list is not supported. -- C Function: int PyTuple_SetItem (PyObject *p, Py_ssize_t pos, PyObject *o) Insert a reference to object `o' at position `pos' of the tuple pointed to by `p'. Return ‘0’ on success. If `pos' is out of bounds, return ‘-1’ and set an *note IndexError: e75. exception. Note: This function “steals” a reference to `o' and discards a reference to an item already in the tuple at the affected position. -- C Function: void PyTuple_SET_ITEM (PyObject *p, Py_ssize_t pos, PyObject *o) Like *note PyTuple_SetItem(): 3861, but does no error checking, and should `only' be used to fill in brand new tuples. Note: This macro “steals” a reference to `o', and, unlike *note PyTuple_SetItem(): 3861, does `not' discard a reference to any item that is being replaced; any reference in the tuple at position `pos' will be leaked. -- C Function: int _PyTuple_Resize (PyObject **p, Py_ssize_t newsize) Can be used to resize a tuple. `newsize' will be the new length of the tuple. Because tuples are `supposed' to be immutable, this should only be used if there is only one reference to the object. Do `not' use this if the tuple may already be known to some other part of the code. The tuple will always grow or shrink at the end. Think of this as destroying the old tuple and creating a new one, only more efficiently. Returns ‘0’ on success. Client code should never assume that the resulting value of ‘*p’ will be the same as before calling this function. If the object referenced by ‘*p’ is replaced, the original ‘*p’ is destroyed. On failure, returns ‘-1’ and sets ‘*p’ to ‘NULL’, and raises *note MemoryError: 13af. or *note SystemError: 5fb. -- C Function: int PyTuple_ClearFreeList () Clear the free list. Return the total number of freed items.  File: python.info, Node: Struct Sequence Objects, Next: List Objects, Prev: Tuple Objects, Up: Sequence Objects 7.8.3.30 Struct Sequence Objects ................................ Struct sequence objects are the C equivalent of *note namedtuple(): 1b7. objects, i.e. a sequence whose items can also be accessed through attributes. To create a struct sequence, you first have to create a specific struct sequence type. -- C Function: PyTypeObject* PyStructSequence_NewType (PyStructSequence_Desc *desc) `Return value: New reference.' Create a new struct sequence type from the data in `desc', described below. Instances of the resulting type can be created with *note PyStructSequence_New(): 3ba1. -- C Function: void PyStructSequence_InitType (PyTypeObject *type, PyStructSequence_Desc *desc) Initializes a struct sequence type `type' from `desc' in place. -- C Function: int PyStructSequence_InitType2 (PyTypeObject *type, PyStructSequence_Desc *desc) The same as ‘PyStructSequence_InitType’, but returns ‘0’ on success and ‘-1’ on failure. New in version 3.4. -- C Type: PyStructSequence_Desc Contains the meta information of a struct sequence type to create. Field C Type Meaning ------------------------------------------------------------------------------------------------------ ‘name’ ‘const char *’ name of the struct sequence type ‘doc’ ‘const char *’ pointer to docstring for the type or ‘NULL’ to omit ‘fields’ ‘PyStructSequence_Field *’ pointer to ‘NULL’-terminated array with field names of the new type ‘n_in_sequence’ ‘int’ number of fields visible to the Python side (if used as tuple) -- C Type: PyStructSequence_Field Describes a field of a struct sequence. As a struct sequence is modeled as a tuple, all fields are typed as *note PyObject*: 4ba. The index in the ‘fields’ array of the *note PyStructSequence_Desc: 429. determines which field of the struct sequence is described. Field C Type Meaning ------------------------------------------------------------------------------------- ‘name’ ‘const char *’ name for the field or ‘NULL’ to end the list of named fields, set to *note PyStructSequence_UnnamedField: 3ba2. to leave unnamed ‘doc’ ‘const char *’ field docstring or ‘NULL’ to omit -- C Variable: char* PyStructSequence_UnnamedField Special value for a field name to leave it unnamed. -- C Function: PyObject* PyStructSequence_New (PyTypeObject *type) `Return value: New reference.' Creates an instance of `type', which must have been created with *note PyStructSequence_NewType(): 3ba0. -- C Function: PyObject* PyStructSequence_GetItem (PyObject *p, Py_ssize_t pos) `Return value: Borrowed reference.' Return the object at position `pos' in the struct sequence pointed to by `p'. No bounds checking is performed. -- C Function: PyObject* PyStructSequence_GET_ITEM (PyObject *p, Py_ssize_t pos) `Return value: Borrowed reference.' Macro equivalent of *note PyStructSequence_GetItem(): 3ba3. -- C Function: void PyStructSequence_SetItem (PyObject *p, Py_ssize_t pos, PyObject *o) Sets the field at index `pos' of the struct sequence `p' to value `o'. Like *note PyTuple_SET_ITEM(): 3b9d, this should only be used to fill in brand new instances. Note: This function “steals” a reference to `o'. -- C Function: void PyStructSequence_SET_ITEM (PyObject *p, Py_ssize_t *pos, PyObject *o) Macro equivalent of *note PyStructSequence_SetItem(): 3ba5. Note: This function “steals” a reference to `o'.  File: python.info, Node: List Objects, Prev: Struct Sequence Objects, Up: Sequence Objects 7.8.3.31 List Objects ..................... -- C Type: PyListObject This subtype of *note PyObject: 4ba. represents a Python list object. -- C Variable: PyTypeObject PyList_Type This instance of *note PyTypeObject: 2d6. represents the Python list type. This is the same object as *note list: 262. in the Python layer. -- C Function: int PyList_Check (PyObject *p) Return true if `p' is a list object or an instance of a subtype of the list type. -- C Function: int PyList_CheckExact (PyObject *p) Return true if `p' is a list object, but not an instance of a subtype of the list type. -- C Function: PyObject* PyList_New (Py_ssize_t len) `Return value: New reference.' Return a new list of length `len' on success, or ‘NULL’ on failure. Note: If `len' is greater than zero, the returned list object’s items are set to ‘NULL’. Thus you cannot use abstract API functions such as *note PySequence_SetItem(): 38f2. or expose the object to Python code before setting all items to a real object with *note PyList_SetItem(): 3862. -- C Function: Py_ssize_t PyList_Size (PyObject *list) Return the length of the list object in `list'; this is equivalent to ‘len(list)’ on a list object. -- C Function: Py_ssize_t PyList_GET_SIZE (PyObject *list) Macro form of *note PyList_Size(): d7e. without error checking. -- C Function: PyObject* PyList_GetItem (PyObject *list, Py_ssize_t index) `Return value: Borrowed reference.' Return the object at position `index' in the list pointed to by `list'. The position must be non-negative; indexing from the end of the list is not supported. If `index' is out of bounds (<0 or >=len(list)), return ‘NULL’ and set an *note IndexError: e75. exception. -- C Function: PyObject* PyList_GET_ITEM (PyObject *list, Py_ssize_t i) `Return value: Borrowed reference.' Macro form of *note PyList_GetItem(): 385d. without error checking. -- C Function: int PyList_SetItem (PyObject *list, Py_ssize_t index, PyObject *item) Set the item at index `index' in list to `item'. Return ‘0’ on success. If `index' is out of bounds, return ‘-1’ and set an *note IndexError: e75. exception. Note: This function “steals” a reference to `item' and discards a reference to an item already in the list at the affected position. -- C Function: void PyList_SET_ITEM (PyObject *list, Py_ssize_t i, PyObject *o) Macro form of *note PyList_SetItem(): 3862. without error checking. This is normally only used to fill in new lists where there is no previous content. Note: This macro “steals” a reference to `item', and, unlike *note PyList_SetItem(): 3862, does `not' discard a reference to any item that is being replaced; any reference in `list' at position `i' will be leaked. -- C Function: int PyList_Insert (PyObject *list, Py_ssize_t index, PyObject *item) Insert the item `item' into list `list' in front of index `index'. Return ‘0’ if successful; return ‘-1’ and set an exception if unsuccessful. Analogous to ‘list.insert(index, item)’. -- C Function: int PyList_Append (PyObject *list, PyObject *item) Append the object `item' at the end of list `list'. Return ‘0’ if successful; return ‘-1’ and set an exception if unsuccessful. Analogous to ‘list.append(item)’. -- C Function: PyObject* PyList_GetSlice (PyObject *list, Py_ssize_t low, Py_ssize_t high) `Return value: New reference.' Return a list of the objects in `list' containing the objects `between' `low' and `high'. Return ‘NULL’ and set an exception if unsuccessful. Analogous to ‘list[low:high]’. Indexing from the end of the list is not supported. -- C Function: int PyList_SetSlice (PyObject *list, Py_ssize_t low, Py_ssize_t high, PyObject *itemlist) Set the slice of `list' between `low' and `high' to the contents of `itemlist'. Analogous to ‘list[low:high] = itemlist’. The `itemlist' may be ‘NULL’, indicating the assignment of an empty list (slice deletion). Return ‘0’ on success, ‘-1’ on failure. Indexing from the end of the list is not supported. -- C Function: int PyList_Sort (PyObject *list) Sort the items of `list' in place. Return ‘0’ on success, ‘-1’ on failure. This is equivalent to ‘list.sort()’. -- C Function: int PyList_Reverse (PyObject *list) Reverse the items of `list' in place. Return ‘0’ on success, ‘-1’ on failure. This is the equivalent of ‘list.reverse()’. -- C Function: PyObject* PyList_AsTuple (PyObject *list) `Return value: New reference.' Return a new tuple object containing the contents of `list'; equivalent to ‘tuple(list)’. -- C Function: int PyList_ClearFreeList () Clear the free list. Return the total number of freed items. New in version 3.3.  File: python.info, Node: Container Objects, Next: Function Objects<2>, Prev: Sequence Objects, Up: Concrete Objects Layer 7.8.4 Container Objects ----------------------- * Menu: * Dictionary Objects:: * Set Objects::  File: python.info, Node: Dictionary Objects, Next: Set Objects, Up: Container Objects 7.8.4.1 Dictionary Objects .......................... -- C Type: PyDictObject This subtype of *note PyObject: 4ba. represents a Python dictionary object. -- C Variable: PyTypeObject PyDict_Type This instance of *note PyTypeObject: 2d6. represents the Python dictionary type. This is the same object as *note dict: 1b8. in the Python layer. -- C Function: int PyDict_Check (PyObject *p) Return true if `p' is a dict object or an instance of a subtype of the dict type. -- C Function: int PyDict_CheckExact (PyObject *p) Return true if `p' is a dict object, but not an instance of a subtype of the dict type. -- C Function: PyObject* PyDict_New () `Return value: New reference.' Return a new empty dictionary, or ‘NULL’ on failure. -- C Function: PyObject* PyDictProxy_New (PyObject *mapping) `Return value: New reference.' Return a *note types.MappingProxyType: ab6. object for a mapping which enforces read-only behavior. This is normally used to create a view to prevent modification of the dictionary for non-dynamic class types. -- C Function: void PyDict_Clear (PyObject *p) Empty an existing dictionary of all key-value pairs. -- C Function: int PyDict_Contains (PyObject *p, PyObject *key) Determine if dictionary `p' contains `key'. If an item in `p' is matches `key', return ‘1’, otherwise return ‘0’. On error, return ‘-1’. This is equivalent to the Python expression ‘key in p’. -- C Function: PyObject* PyDict_Copy (PyObject *p) `Return value: New reference.' Return a new dictionary that contains the same key-value pairs as `p'. -- C Function: int PyDict_SetItem (PyObject *p, PyObject *key, PyObject *val) Insert `val' into the dictionary `p' with a key of `key'. `key' must be *note hashable: 10c8.; if it isn’t, *note TypeError: 192. will be raised. Return ‘0’ on success or ‘-1’ on failure. This function `does not' steal a reference to `val'. -- C Function: int PyDict_SetItemString (PyObject *p, const char *key, PyObject *val) Insert `val' into the dictionary `p' using `key' as a key. `key' should be a ‘const char*’. The key object is created using ‘PyUnicode_FromString(key)’. Return ‘0’ on success or ‘-1’ on failure. This function `does not' steal a reference to `val'. -- C Function: int PyDict_DelItem (PyObject *p, PyObject *key) Remove the entry in dictionary `p' with key `key'. `key' must be hashable; if it isn’t, *note TypeError: 192. is raised. If `key' is not in the dictionary, *note KeyError: 2c7. is raised. Return ‘0’ on success or ‘-1’ on failure. -- C Function: int PyDict_DelItemString (PyObject *p, const char *key) Remove the entry in dictionary `p' which has a key specified by the string `key'. If `key' is not in the dictionary, *note KeyError: 2c7. is raised. Return ‘0’ on success or ‘-1’ on failure. -- C Function: PyObject* PyDict_GetItem (PyObject *p, PyObject *key) `Return value: Borrowed reference.' Return the object from dictionary `p' which has a key `key'. Return ‘NULL’ if the key `key' is not present, but `without' setting an exception. Note that exceptions which occur while calling *note __hash__(): 340. and *note __eq__(): 33f. methods will get suppressed. To get error reporting use *note PyDict_GetItemWithError(): 3bc7. instead. -- C Function: PyObject* PyDict_GetItemWithError (PyObject *p, PyObject *key) `Return value: Borrowed reference.' Variant of *note PyDict_GetItem(): 385e. that does not suppress exceptions. Return ‘NULL’ `with' an exception set if an exception occurred. Return ‘NULL’ `without' an exception set if the key wasn’t present. -- C Function: PyObject* PyDict_GetItemString (PyObject *p, const char *key) `Return value: Borrowed reference.' This is the same as *note PyDict_GetItem(): 385e, but `key' is specified as a ‘const char*’, rather than a *note PyObject*: 4ba. Note that exceptions which occur while calling *note __hash__(): 340. and *note __eq__(): 33f. methods and creating a temporary string object will get suppressed. To get error reporting use *note PyDict_GetItemWithError(): 3bc7. instead. -- C Function: PyObject* PyDict_SetDefault (PyObject *p, PyObject *key, PyObject *defaultobj) `Return value: Borrowed reference.' This is the same as the Python-level *note dict.setdefault(): 9bf. If present, it returns the value corresponding to `key' from the dictionary `p'. If the key is not in the dict, it is inserted with value `defaultobj' and `defaultobj' is returned. This function evaluates the hash function of `key' only once, instead of evaluating it independently for the lookup and the insertion. New in version 3.4. -- C Function: PyObject* PyDict_Items (PyObject *p) `Return value: New reference.' Return a *note PyListObject: 3a56. containing all the items from the dictionary. -- C Function: PyObject* PyDict_Keys (PyObject *p) `Return value: New reference.' Return a *note PyListObject: 3a56. containing all the keys from the dictionary. -- C Function: PyObject* PyDict_Values (PyObject *p) `Return value: New reference.' Return a *note PyListObject: 3a56. containing all the values from the dictionary `p'. -- C Function: Py_ssize_t PyDict_Size (PyObject *p) Return the number of items in the dictionary. This is equivalent to ‘len(p)’ on a dictionary. -- C Function: int PyDict_Next (PyObject *p, Py_ssize_t *ppos, PyObject **pkey, PyObject **pvalue) Iterate over all key-value pairs in the dictionary `p'. The ‘Py_ssize_t’ referred to by `ppos' must be initialized to ‘0’ prior to the first call to this function to start the iteration; the function returns true for each pair in the dictionary, and false once all pairs have been reported. The parameters `pkey' and `pvalue' should either point to *note PyObject*: 4ba. variables that will be filled in with each key and value, respectively, or may be ‘NULL’. Any references returned through them are borrowed. `ppos' should not be altered during iteration. Its value represents offsets within the internal dictionary structure, and since the structure is sparse, the offsets are not consecutive. For example: PyObject *key, *value; Py_ssize_t pos = 0; while (PyDict_Next(self->dict, &pos, &key, &value)) { /* do something interesting with the values... */ ... } The dictionary `p' should not be mutated during iteration. It is safe to modify the values of the keys as you iterate over the dictionary, but only so long as the set of keys does not change. For example: PyObject *key, *value; Py_ssize_t pos = 0; while (PyDict_Next(self->dict, &pos, &key, &value)) { long i = PyLong_AsLong(value); if (i == -1 && PyErr_Occurred()) { return -1; } PyObject *o = PyLong_FromLong(i + 1); if (o == NULL) return -1; if (PyDict_SetItem(self->dict, key, o) < 0) { Py_DECREF(o); return -1; } Py_DECREF(o); } -- C Function: int PyDict_Merge (PyObject *a, PyObject *b, int override) Iterate over mapping object `b' adding key-value pairs to dictionary `a'. `b' may be a dictionary, or any object supporting *note PyMapping_Keys(): 42c. and *note PyObject_GetItem(): 38f5. If `override' is true, existing pairs in `a' will be replaced if a matching key is found in `b', otherwise pairs will only be added if there is not a matching key in `a'. Return ‘0’ on success or ‘-1’ if an exception was raised. -- C Function: int PyDict_Update (PyObject *a, PyObject *b) This is the same as ‘PyDict_Merge(a, b, 1)’ in C, and is similar to ‘a.update(b)’ in Python except that *note PyDict_Update(): 3bcf. doesn’t fall back to the iterating over a sequence of key value pairs if the second argument has no “keys” attribute. Return ‘0’ on success or ‘-1’ if an exception was raised. -- C Function: int PyDict_MergeFromSeq2 (PyObject *a, PyObject *seq2, int override) Update or merge into dictionary `a', from the key-value pairs in `seq2'. `seq2' must be an iterable object producing iterable objects of length 2, viewed as key-value pairs. In case of duplicate keys, the last wins if `override' is true, else the first wins. Return ‘0’ on success or ‘-1’ if an exception was raised. Equivalent Python (except for the return value): def PyDict_MergeFromSeq2(a, seq2, override): for key, value in seq2: if override or key not in a: a[key] = value -- C Function: int PyDict_ClearFreeList () Clear the free list. Return the total number of freed items. New in version 3.3.  File: python.info, Node: Set Objects, Prev: Dictionary Objects, Up: Container Objects 7.8.4.2 Set Objects ................... This section details the public API for *note set: b6f. and *note frozenset: bee. objects. Any functionality not listed below is best accessed using the either the abstract object protocol (including *note PyObject_CallMethod(): 3a0e, *note PyObject_RichCompareBool(): 38a7, *note PyObject_Hash(): 3a15, *note PyObject_Repr(): 968, *note PyObject_IsTrue(): 3a16, *note PyObject_Print(): 39fe, and *note PyObject_GetIter(): 3a1d.) or the abstract number protocol (including *note PyNumber_And(): 3a2f, *note PyNumber_Subtract(): 3a22, *note PyNumber_Or(): 3a31, *note PyNumber_Xor(): 3a30, *note PyNumber_InPlaceAnd(): 3a3b, *note PyNumber_InPlaceSubtract(): 3a33, *note PyNumber_InPlaceOr(): 3a3d, and *note PyNumber_InPlaceXor(): 3a3c.). -- C Type: PySetObject This subtype of *note PyObject: 4ba. is used to hold the internal data for both *note set: b6f. and *note frozenset: bee. objects. It is like a *note PyDictObject: 3bbc. in that it is a fixed size for small sets (much like tuple storage) and will point to a separate, variable sized block of memory for medium and large sized sets (much like list storage). None of the fields of this structure should be considered public and are subject to change. All access should be done through the documented API rather than by manipulating the values in the structure. -- C Variable: PyTypeObject PySet_Type This is an instance of *note PyTypeObject: 2d6. representing the Python *note set: b6f. type. -- C Variable: PyTypeObject PyFrozenSet_Type This is an instance of *note PyTypeObject: 2d6. representing the Python *note frozenset: bee. type. The following type check macros work on pointers to any Python object. Likewise, the constructor functions work with any iterable Python object. -- C Function: int PySet_Check (PyObject *p) Return true if `p' is a *note set: b6f. object or an instance of a subtype. -- C Function: int PyFrozenSet_Check (PyObject *p) Return true if `p' is a *note frozenset: bee. object or an instance of a subtype. -- C Function: int PyAnySet_Check (PyObject *p) Return true if `p' is a *note set: b6f. object, a *note frozenset: bee. object, or an instance of a subtype. -- C Function: int PyAnySet_CheckExact (PyObject *p) Return true if `p' is a *note set: b6f. object or a *note frozenset: bee. object but not an instance of a subtype. -- C Function: int PyFrozenSet_CheckExact (PyObject *p) Return true if `p' is a *note frozenset: bee. object but not an instance of a subtype. -- C Function: PyObject* PySet_New (PyObject *iterable) `Return value: New reference.' Return a new *note set: b6f. containing objects returned by the `iterable'. The `iterable' may be ‘NULL’ to create a new empty set. Return the new set on success or ‘NULL’ on failure. Raise *note TypeError: 192. if `iterable' is not actually iterable. The constructor is also useful for copying a set (‘c=set(s)’). -- C Function: PyObject* PyFrozenSet_New (PyObject *iterable) `Return value: New reference.' Return a new *note frozenset: bee. containing objects returned by the `iterable'. The `iterable' may be ‘NULL’ to create a new empty frozenset. Return the new set on success or ‘NULL’ on failure. Raise *note TypeError: 192. if `iterable' is not actually iterable. The following functions and macros are available for instances of *note set: b6f. or *note frozenset: bee. or instances of their subtypes. -- C Function: Py_ssize_t PySet_Size (PyObject *anyset) Return the length of a *note set: b6f. or *note frozenset: bee. object. Equivalent to ‘len(anyset)’. Raises a ‘PyExc_SystemError’ if `anyset' is not a *note set: b6f, *note frozenset: bee, or an instance of a subtype. -- C Function: Py_ssize_t PySet_GET_SIZE (PyObject *anyset) Macro form of *note PySet_Size(): db0. without error checking. -- C Function: int PySet_Contains (PyObject *anyset, PyObject *key) Return ‘1’ if found, ‘0’ if not found, and ‘-1’ if an error is encountered. Unlike the Python *note __contains__(): d28. method, this function does not automatically convert unhashable sets into temporary frozensets. Raise a *note TypeError: 192. if the `key' is unhashable. Raise ‘PyExc_SystemError’ if `anyset' is not a *note set: b6f, *note frozenset: bee, or an instance of a subtype. -- C Function: int PySet_Add (PyObject *set, PyObject *key) Add `key' to a *note set: b6f. instance. Also works with *note frozenset: bee. instances (like *note PyTuple_SetItem(): 3861. it can be used to fill-in the values of brand new frozensets before they are exposed to other code). Return ‘0’ on success or ‘-1’ on failure. Raise a *note TypeError: 192. if the `key' is unhashable. Raise a *note MemoryError: 13af. if there is no room to grow. Raise a *note SystemError: 5fb. if `set' is not an instance of *note set: b6f. or its subtype. The following functions are available for instances of *note set: b6f. or its subtypes but not for instances of *note frozenset: bee. or its subtypes. -- C Function: int PySet_Discard (PyObject *set, PyObject *key) Return ‘1’ if found and removed, ‘0’ if not found (no action taken), and ‘-1’ if an error is encountered. Does not raise *note KeyError: 2c7. for missing keys. Raise a *note TypeError: 192. if the `key' is unhashable. Unlike the Python ‘discard()’ method, this function does not automatically convert unhashable sets into temporary frozensets. Raise ‘PyExc_SystemError’ if `set' is not an instance of *note set: b6f. or its subtype. -- C Function: PyObject* PySet_Pop (PyObject *set) `Return value: New reference.' Return a new reference to an arbitrary object in the `set', and removes the object from the `set'. Return ‘NULL’ on failure. Raise *note KeyError: 2c7. if the set is empty. Raise a *note SystemError: 5fb. if `set' is not an instance of *note set: b6f. or its subtype. -- C Function: int PySet_Clear (PyObject *set) Empty an existing set of all elements. -- C Function: int PySet_ClearFreeList () Clear the free list. Return the total number of freed items. New in version 3.3.  File: python.info, Node: Function Objects<2>, Next: Other Objects, Prev: Container Objects, Up: Concrete Objects Layer 7.8.5 Function Objects ---------------------- * Menu: * Function Objects: Function Objects<3>. * Instance Method Objects:: * Method Objects: Method Objects<2>. * Cell Objects:: * Code Objects: Code Objects<2>.  File: python.info, Node: Function Objects<3>, Next: Instance Method Objects, Up: Function Objects<2> 7.8.5.1 Function Objects ........................ There are a few functions specific to Python functions. -- C Type: PyFunctionObject The C structure used for functions. -- C Variable: PyTypeObject PyFunction_Type This is an instance of *note PyTypeObject: 2d6. and represents the Python function type. It is exposed to Python programmers as ‘types.FunctionType’. -- C Function: int PyFunction_Check (PyObject *o) Return true if `o' is a function object (has type *note PyFunction_Type: 3be7.). The parameter must not be ‘NULL’. -- C Function: PyObject* PyFunction_New (PyObject *code, PyObject *globals) `Return value: New reference.' Return a new function object associated with the code object `code'. `globals' must be a dictionary with the global variables accessible to the function. The function’s docstring and name are retrieved from the code object. `__module__' is retrieved from `globals'. The argument defaults, annotations and closure are set to ‘NULL’. `__qualname__' is set to the same value as the function’s name. -- C Function: PyObject* PyFunction_NewWithQualName (PyObject *code, PyObject *globals, PyObject *qualname) `Return value: New reference.' As *note PyFunction_New(): 3be9, but also allows setting the function object’s ‘__qualname__’ attribute. `qualname' should be a unicode object or ‘NULL’; if ‘NULL’, the ‘__qualname__’ attribute is set to the same value as its ‘__name__’ attribute. New in version 3.3. -- C Function: PyObject* PyFunction_GetCode (PyObject *op) `Return value: Borrowed reference.' Return the code object associated with the function object `op'. -- C Function: PyObject* PyFunction_GetGlobals (PyObject *op) `Return value: Borrowed reference.' Return the globals dictionary associated with the function object `op'. -- C Function: PyObject* PyFunction_GetModule (PyObject *op) `Return value: Borrowed reference.' Return the `__module__' attribute of the function object `op'. This is normally a string containing the module name, but can be set to any other object by Python code. -- C Function: PyObject* PyFunction_GetDefaults (PyObject *op) `Return value: Borrowed reference.' Return the argument default values of the function object `op'. This can be a tuple of arguments or ‘NULL’. -- C Function: int PyFunction_SetDefaults (PyObject *op, PyObject *defaults) Set the argument default values for the function object `op'. `defaults' must be ‘Py_None’ or a tuple. Raises *note SystemError: 5fb. and returns ‘-1’ on failure. -- C Function: PyObject* PyFunction_GetClosure (PyObject *op) `Return value: Borrowed reference.' Return the closure associated with the function object `op'. This can be ‘NULL’ or a tuple of cell objects. -- C Function: int PyFunction_SetClosure (PyObject *op, PyObject *closure) Set the closure associated with the function object `op'. `closure' must be ‘Py_None’ or a tuple of cell objects. Raises *note SystemError: 5fb. and returns ‘-1’ on failure. -- C Function: PyObject *PyFunction_GetAnnotations (PyObject *op) `Return value: Borrowed reference.' Return the annotations of the function object `op'. This can be a mutable dictionary or ‘NULL’. -- C Function: int PyFunction_SetAnnotations (PyObject *op, PyObject *annotations) Set the annotations for the function object `op'. `annotations' must be a dictionary or ‘Py_None’. Raises *note SystemError: 5fb. and returns ‘-1’ on failure.  File: python.info, Node: Instance Method Objects, Next: Method Objects<2>, Prev: Function Objects<3>, Up: Function Objects<2> 7.8.5.2 Instance Method Objects ............................... An instance method is a wrapper for a *note PyCFunction: ddb. and the new way to bind a *note PyCFunction: ddb. to a class object. It replaces the former call ‘PyMethod_New(func, NULL, class)’. -- C Variable: PyTypeObject PyInstanceMethod_Type This instance of *note PyTypeObject: 2d6. represents the Python instance method type. It is not exposed to Python programs. -- C Function: int PyInstanceMethod_Check (PyObject *o) Return true if `o' is an instance method object (has type *note PyInstanceMethod_Type: 3bf7.). The parameter must not be ‘NULL’. -- C Function: PyObject* PyInstanceMethod_New (PyObject *func) `Return value: New reference.' Return a new instance method object, with `func' being any callable object `func' is the function that will be called when the instance method is called. -- C Function: PyObject* PyInstanceMethod_Function (PyObject *im) `Return value: Borrowed reference.' Return the function object associated with the instance method `im'. -- C Function: PyObject* PyInstanceMethod_GET_FUNCTION (PyObject *im) `Return value: Borrowed reference.' Macro version of *note PyInstanceMethod_Function(): 3bfa. which avoids error checking.  File: python.info, Node: Method Objects<2>, Next: Cell Objects, Prev: Instance Method Objects, Up: Function Objects<2> 7.8.5.3 Method Objects ...................... Methods are bound function objects. Methods are always bound to an instance of a user-defined class. Unbound methods (methods bound to a class object) are no longer available. -- C Variable: PyTypeObject PyMethod_Type This instance of *note PyTypeObject: 2d6. represents the Python method type. This is exposed to Python programs as ‘types.MethodType’. -- C Function: int PyMethod_Check (PyObject *o) Return true if `o' is a method object (has type *note PyMethod_Type: 3bfe.). The parameter must not be ‘NULL’. -- C Function: PyObject* PyMethod_New (PyObject *func, PyObject *self) `Return value: New reference.' Return a new method object, with `func' being any callable object and `self' the instance the method should be bound. `func' is the function that will be called when the method is called. `self' must not be ‘NULL’. -- C Function: PyObject* PyMethod_Function (PyObject *meth) `Return value: Borrowed reference.' Return the function object associated with the method `meth'. -- C Function: PyObject* PyMethod_GET_FUNCTION (PyObject *meth) `Return value: Borrowed reference.' Macro version of *note PyMethod_Function(): 3c01. which avoids error checking. -- C Function: PyObject* PyMethod_Self (PyObject *meth) `Return value: Borrowed reference.' Return the instance associated with the method `meth'. -- C Function: PyObject* PyMethod_GET_SELF (PyObject *meth) `Return value: Borrowed reference.' Macro version of *note PyMethod_Self(): 3c03. which avoids error checking. -- C Function: int PyMethod_ClearFreeList () Clear the free list. Return the total number of freed items.  File: python.info, Node: Cell Objects, Next: Code Objects<2>, Prev: Method Objects<2>, Up: Function Objects<2> 7.8.5.4 Cell Objects .................... “Cell” objects are used to implement variables referenced by multiple scopes. For each such variable, a cell object is created to store the value; the local variables of each stack frame that references the value contains a reference to the cells from outer scopes which also use that variable. When the value is accessed, the value contained in the cell is used instead of the cell object itself. This de-referencing of the cell object requires support from the generated byte-code; these are not automatically de-referenced when accessed. Cell objects are not likely to be useful elsewhere. -- C Type: PyCellObject The C structure used for cell objects. -- C Variable: PyTypeObject PyCell_Type The type object corresponding to cell objects. -- C Function: int PyCell_Check (ob) Return true if `ob' is a cell object; `ob' must not be ‘NULL’. -- C Function: PyObject* PyCell_New (PyObject *ob) `Return value: New reference.' Create and return a new cell object containing the value `ob'. The parameter may be ‘NULL’. -- C Function: PyObject* PyCell_Get (PyObject *cell) `Return value: New reference.' Return the contents of the cell `cell'. -- C Function: PyObject* PyCell_GET (PyObject *cell) `Return value: Borrowed reference.' Return the contents of the cell `cell', but without checking that `cell' is non-‘NULL’ and a cell object. -- C Function: int PyCell_Set (PyObject *cell, PyObject *value) Set the contents of the cell object `cell' to `value'. This releases the reference to any current content of the cell. `value' may be ‘NULL’. `cell' must be non-‘NULL’; if it is not a cell object, ‘-1’ will be returned. On success, ‘0’ will be returned. -- C Function: void PyCell_SET (PyObject *cell, PyObject *value) Sets the value of the cell object `cell' to `value'. No reference counts are adjusted, and no checks are made for safety; `cell' must be non-‘NULL’ and must be a cell object.  File: python.info, Node: Code Objects<2>, Prev: Cell Objects, Up: Function Objects<2> 7.8.5.5 Code Objects .................... Code objects are a low-level detail of the CPython implementation. Each one represents a chunk of executable code that hasn’t yet been bound into a function. -- C Type: PyCodeObject The C structure of the objects used to describe code objects. The fields of this type are subject to change at any time. -- C Variable: PyTypeObject PyCode_Type This is an instance of *note PyTypeObject: 2d6. representing the Python *note code: 1b. type. -- C Function: int PyCode_Check (PyObject *co) Return true if `co' is a *note code: 1b. object. -- C Function: int PyCode_GetNumFree (PyCodeObject *co) Return the number of free variables in `co'. -- C Function: PyCodeObject* PyCode_New (int argcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *lnotab) `Return value: New reference.' Return a new code object. If you need a dummy code object to create a frame, use *note PyCode_NewEmpty(): cea. instead. Calling *note PyCode_New(): 272. directly can bind you to a precise Python version since the definition of the bytecode changes often. -- C Function: PyCodeObject* PyCode_NewWithPosOnlyArgs (int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *lnotab) `Return value: New reference.' Similar to *note PyCode_New(): 272, but with an extra “posonlyargcount” for positional-only arguments. New in version 3.8. -- C Function: PyCodeObject* PyCode_NewEmpty (const char *filename, const char *funcname, int firstlineno) `Return value: New reference.' Return a new empty code object with the specified filename, function name, and first line number. It is illegal to *note exec(): c44. or *note eval(): b90. the resulting code object.  File: python.info, Node: Other Objects, Prev: Function Objects<2>, Up: Concrete Objects Layer 7.8.6 Other Objects ------------------- * Menu: * File Objects:: * Module Objects:: * Iterator Objects:: * Descriptor Objects:: * Slice Objects:: * Ellipsis Object:: * MemoryView objects:: * Weak Reference Objects: Weak Reference Objects<2>. * Capsules: Capsules<2>. * Generator Objects:: * Coroutine Objects: Coroutine Objects<2>. * Context Variables Objects:: * DateTime Objects: DateTime Objects<2>.  File: python.info, Node: File Objects, Next: Module Objects, Up: Other Objects 7.8.6.1 File Objects .................... These APIs are a minimal emulation of the Python 2 C API for built-in file objects, which used to rely on the buffered I/O (‘FILE*’) support from the C standard library. In Python 3, files and streams use the new *note io: a1. module, which defines several layers over the low-level unbuffered I/O of the operating system. The functions described below are convenience C wrappers over these new APIs, and meant mostly for internal error reporting in the interpreter; third-party code is advised to access the *note io: a1. APIs instead. -- C Function: PyObject* PyFile_FromFd (int fd, const char *name, const char *mode, int buffering, const char *encoding, const char *errors, const char *newline, int closefd) `Return value: New reference.' Create a Python file object from the file descriptor of an already opened file `fd'. The arguments `name', `encoding', `errors' and `newline' can be ‘NULL’ to use the defaults; `buffering' can be `-1' to use the default. `name' is ignored and kept for backward compatibility. Return ‘NULL’ on failure. For a more comprehensive description of the arguments, please refer to the *note io.open(): 65a. function documentation. Warning: Since Python streams have their own buffering layer, mixing them with OS-level file descriptors can produce various issues (such as unexpected ordering of data). Changed in version 3.2: Ignore `name' attribute. -- C Function: int PyObject_AsFileDescriptor (PyObject *p) Return the file descriptor associated with `p' as an ‘int’. If the object is an integer, its value is returned. If not, the object’s *note fileno(): 1bdb. method is called if it exists; the method must return an integer, which is returned as the file descriptor value. Sets an exception and returns ‘-1’ on failure. -- C Function: PyObject* PyFile_GetLine (PyObject *p, int n) `Return value: New reference.' Equivalent to ‘p.readline([n])’, this function reads one line from the object `p'. `p' may be a file object or any object with a *note readline(): 13ae. method. If `n' is ‘0’, exactly one line is read, regardless of the length of the line. If `n' is greater than ‘0’, no more than `n' bytes will be read from the file; a partial line can be returned. In both cases, an empty string is returned if the end of the file is reached immediately. If `n' is less than ‘0’, however, one line is read regardless of length, but *note EOFError: c6c. is raised if the end of the file is reached immediately. -- C Function: int PyFile_SetOpenCodeHook (Py_OpenCodeHookFunction handler) Overrides the normal behavior of *note io.open_code(): 1cc0. to pass its parameter through the provided handler. The handler is a function of type ‘PyObject *(*)(PyObject *path, void *userData)’, where `path' is guaranteed to be *note PyUnicodeObject: 3b3c. The `userData' pointer is passed into the hook function. Since hook functions may be called from different runtimes, this pointer should not refer directly to Python state. As this hook is intentionally used during import, avoid importing new modules during its execution unless they are known to be frozen or available in ‘sys.modules’. Once a hook has been set, it cannot be removed or replaced, and later calls to *note PyFile_SetOpenCodeHook(): 1cc1. will fail. On failure, the function returns -1 and sets an exception if the interpreter has been initialized. This function is safe to call before *note Py_Initialize(): 439. Raises an *note auditing event: fd1. ‘setopencodehook’ with no arguments. New in version 3.8. -- C Function: int PyFile_WriteObject (PyObject *obj, PyObject *p, int flags) Write object `obj' to file object `p'. The only supported flag for `flags' is ‘Py_PRINT_RAW’; if given, the *note str(): 330. of the object is written instead of the *note repr(): 7cc. Return ‘0’ on success or ‘-1’ on failure; the appropriate exception will be set. -- C Function: int PyFile_WriteString (const char *s, PyObject *p) Write string `s' to file object `p'. Return ‘0’ on success or ‘-1’ on failure; the appropriate exception will be set.  File: python.info, Node: Module Objects, Next: Iterator Objects, Prev: File Objects, Up: Other Objects 7.8.6.2 Module Objects ...................... -- C Variable: PyTypeObject PyModule_Type This instance of *note PyTypeObject: 2d6. represents the Python module type. This is exposed to Python programs as ‘types.ModuleType’. -- C Function: int PyModule_Check (PyObject *p) Return true if `p' is a module object, or a subtype of a module object. -- C Function: int PyModule_CheckExact (PyObject *p) Return true if `p' is a module object, but not a subtype of *note PyModule_Type: 3c24. -- C Function: PyObject* PyModule_NewObject (PyObject *name) `Return value: New reference.' Return a new module object with the *note __name__: d12. attribute set to `name'. The module’s *note __name__: d12, ‘__doc__’, *note __package__: 955, and *note __loader__: 956. attributes are filled in (all but *note __name__: d12. are set to ‘None’); the caller is responsible for providing a *note __file__: 10d0. attribute. New in version 3.3. Changed in version 3.4: *note __package__: 955. and *note __loader__: 956. are set to ‘None’. -- C Function: PyObject* PyModule_New (const char *name) `Return value: New reference.' Similar to *note PyModule_NewObject(): 3c27, but the name is a UTF-8 encoded string instead of a Unicode object. -- C Function: PyObject* PyModule_GetDict (PyObject *module) `Return value: Borrowed reference.' Return the dictionary object that implements `module'’s namespace; this object is the same as the *note __dict__: 4fc. attribute of the module object. If `module' is not a module object (or a subtype of a module object), *note SystemError: 5fb. is raised and ‘NULL’ is returned. It is recommended extensions use other ‘PyModule_*()’ and ‘PyObject_*()’ functions rather than directly manipulate a module’s *note __dict__: 4fc. -- C Function: PyObject* PyModule_GetNameObject (PyObject *module) `Return value: New reference.' Return `module'’s *note __name__: d12. value. If the module does not provide one, or if it is not a string, *note SystemError: 5fb. is raised and ‘NULL’ is returned. New in version 3.3. -- C Function: const char* PyModule_GetName (PyObject *module) Similar to *note PyModule_GetNameObject(): 3c2a. but return the name encoded to ‘'utf-8'’. -- C Function: void* PyModule_GetState (PyObject *module) Return the “state” of the module, that is, a pointer to the block of memory allocated at module creation time, or ‘NULL’. See *note PyModuleDef.m_size: 3c2d. -- C Function: PyModuleDef* PyModule_GetDef (PyObject *module) Return a pointer to the *note PyModuleDef: 3888. struct from which the module was created, or ‘NULL’ if the module wasn’t created from a definition. -- C Function: PyObject* PyModule_GetFilenameObject (PyObject *module) `Return value: New reference.' Return the name of the file from which `module' was loaded using `module'’s *note __file__: 10d0. attribute. If this is not defined, or if it is not a unicode string, raise *note SystemError: 5fb. and return ‘NULL’; otherwise return a reference to a Unicode object. New in version 3.2. -- C Function: const char* PyModule_GetFilename (PyObject *module) Similar to *note PyModule_GetFilenameObject(): 3c2f. but return the filename encoded to ‘utf-8’. Deprecated since version 3.2: *note PyModule_GetFilename(): 3c30. raises ‘UnicodeEncodeError’ on unencodable filenames, use *note PyModule_GetFilenameObject(): 3c2f. instead. * Menu: * Initializing C modules:: * Module lookup::  File: python.info, Node: Initializing C modules, Next: Module lookup, Up: Module Objects 7.8.6.3 Initializing C modules .............................. Modules objects are usually created from extension modules (shared libraries which export an initialization function), or compiled-in modules (where the initialization function is added using *note PyImport_AppendInittab(): 3848.). See *note Building C and C++ Extensions: 384b. or *note Extending Embedded Python: 38d3. for details. The initialization function can either pass a module definition instance to *note PyModule_Create(): 3847, and return the resulting module object, or request “multi-phase initialization” by returning the definition struct itself. -- C Type: PyModuleDef The module definition struct, which holds all information needed to create a module object. There is usually only one statically initialized variable of this type for each module. -- C Member: PyModuleDef_Base m_base Always initialize this member to ‘PyModuleDef_HEAD_INIT’. -- C Member: const char *m_name Name for the new module. -- C Member: const char *m_doc Docstring for the module; usually a docstring variable created with *note PyDoc_STRVAR: 38ea. is used. -- C Member: Py_ssize_t m_size Module state may be kept in a per-module memory area that can be retrieved with *note PyModule_GetState(): 3c2c, rather than in static globals. This makes modules safe for use in multiple sub-interpreters. This memory area is allocated based on `m_size' on module creation, and freed when the module object is deallocated, after the ‘m_free’ function has been called, if present. Setting ‘m_size’ to ‘-1’ means that the module does not support sub-interpreters, because it has global state. Setting it to a non-negative value means that the module can be re-initialized and specifies the additional amount of memory it requires for its state. Non-negative ‘m_size’ is required for multi-phase initialization. See PEP 3121(1) for more details. -- C Member: PyMethodDef* m_methods A pointer to a table of module-level functions, described by *note PyMethodDef: e1b. values. Can be ‘NULL’ if no functions are present. -- C Member: PyModuleDef_Slot* m_slots An array of slot definitions for multi-phase initialization, terminated by a ‘{0, NULL}’ entry. When using single-phase initialization, `m_slots' must be ‘NULL’. Changed in version 3.5: Prior to version 3.5, this member was always set to ‘NULL’, and was defined as: -- C Member: inquiry m_reload -- C Member: traverseproc m_traverse A traversal function to call during GC traversal of the module object, or ‘NULL’ if not needed. This function may be called before module state is allocated (*note PyModule_GetState(): 3c2c. may return ‘NULL’), and before the *note Py_mod_exec: 3c39. function is executed. -- C Member: inquiry m_clear A clear function to call during GC clearing of the module object, or ‘NULL’ if not needed. This function may be called before module state is allocated (*note PyModule_GetState(): 3c2c. may return ‘NULL’), and before the *note Py_mod_exec: 3c39. function is executed. -- C Member: freefunc m_free A function to call during deallocation of the module object, or ‘NULL’ if not needed. This function may be called before module state is allocated (*note PyModule_GetState(): 3c2c. may return ‘NULL’), and before the *note Py_mod_exec: 3c39. function is executed. * Menu: * Single-phase initialization:: * Multi-phase initialization:: * Low-level module creation functions:: * Support functions:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3121  File: python.info, Node: Single-phase initialization, Next: Multi-phase initialization, Up: Initializing C modules 7.8.6.4 Single-phase initialization ................................... The module initialization function may create and return the module object directly. This is referred to as “single-phase initialization”, and uses one of the following two module creation functions: -- C Function: PyObject* PyModule_Create (PyModuleDef *def) `Return value: New reference.' Create a new module object, given the definition in `def'. This behaves like *note PyModule_Create2(): 3c3d. with `module_api_version' set to ‘PYTHON_API_VERSION’. -- C Function: PyObject* PyModule_Create2 (PyModuleDef *def, int module_api_version) `Return value: New reference.' Create a new module object, given the definition in `def', assuming the API version `module_api_version'. If that version does not match the version of the running interpreter, a *note RuntimeWarning: 2c0. is emitted. Note: Most uses of this function should be using *note PyModule_Create(): 3847. instead; only use this if you are sure you need it. Before it is returned from in the initialization function, the resulting module object is typically populated using functions like *note PyModule_AddObject(): 3c3e.  File: python.info, Node: Multi-phase initialization, Next: Low-level module creation functions, Prev: Single-phase initialization, Up: Initializing C modules 7.8.6.5 Multi-phase initialization .................................. An alternate way to specify extensions is to request “multi-phase initialization”. Extension modules created this way behave more like Python modules: the initialization is split between the `creation phase', when the module object is created, and the `execution phase', when it is populated. The distinction is similar to the *note __new__(): 889. and *note __init__(): d5e. methods of classes. Unlike modules created using single-phase initialization, these modules are not singletons: if the `sys.modules' entry is removed and the module is re-imported, a new module object is created, and the old module is subject to normal garbage collection – as with Python modules. By default, multiple modules created from the same definition should be independent: changes to one should not affect the others. This means that all state should be specific to the module object (using e.g. using *note PyModule_GetState(): 3c2c.), or its contents (such as the module’s *note __dict__: 4fc. or individual classes created with *note PyType_FromSpec(): 2d1.). All modules created using multi-phase initialization are expected to support *note sub-interpreters: 398b. Making sure multiple modules are independent is typically enough to achieve this. To request multi-phase initialization, the initialization function (PyInit_modulename) returns a *note PyModuleDef: 3888. instance with non-empty *note m_slots: 3c36. Before it is returned, the ‘PyModuleDef’ instance must be initialized with the following function: -- C Function: PyObject* PyModuleDef_Init (PyModuleDef *def) `Return value: Borrowed reference.' Ensures a module definition is a properly initialized Python object that correctly reports its type and reference count. Returns `def' cast to ‘PyObject*’, or ‘NULL’ if an error occurred. New in version 3.5. The `m_slots' member of the module definition must point to an array of ‘PyModuleDef_Slot’ structures: -- C Type: PyModuleDef_Slot -- C Member: int slot A slot ID, chosen from the available values explained below. -- C Member: void* value Value of the slot, whose meaning depends on the slot ID. New in version 3.5. The `m_slots' array must be terminated by a slot with id 0. The available slot types are: -- C Macro: Py_mod_create Specifies a function that is called to create the module object itself. The `value' pointer of this slot must point to a function of the signature: -- C Function: PyObject* create_module (PyObject *spec, PyModuleDef *def) The function receives a *note ModuleSpec: 116b. instance, as defined in PEP 451(1), and the module definition. It should return a new module object, or set an error and return ‘NULL’. This function should be kept minimal. In particular, it should not call arbitrary Python code, as trying to import the same module again may result in an infinite loop. Multiple ‘Py_mod_create’ slots may not be specified in one module definition. If ‘Py_mod_create’ is not specified, the import machinery will create a normal module object using *note PyModule_New(): 3c28. The name is taken from `spec', not the definition, to allow extension modules to dynamically adjust to their place in the module hierarchy and be imported under different names through symlinks, all while sharing a single module definition. There is no requirement for the returned object to be an instance of *note PyModule_Type: 3c24. Any type can be used, as long as it supports setting and getting import-related attributes. However, only ‘PyModule_Type’ instances may be returned if the ‘PyModuleDef’ has non-‘NULL’ ‘m_traverse’, ‘m_clear’, ‘m_free’; non-zero ‘m_size’; or slots other than ‘Py_mod_create’. -- C Macro: Py_mod_exec Specifies a function that is called to `execute' the module. This is equivalent to executing the code of a Python module: typically, this function adds classes and constants to the module. The signature of the function is: -- C Function: int exec_module (PyObject* module) If multiple ‘Py_mod_exec’ slots are specified, they are processed in the order they appear in the `m_slots' array. See PEP 489(2) for more details on multi-phase initialization. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0451 (2) https://www.python.org/dev/peps/pep-0489  File: python.info, Node: Low-level module creation functions, Next: Support functions, Prev: Multi-phase initialization, Up: Initializing C modules 7.8.6.6 Low-level module creation functions ........................................... The following functions are called under the hood when using multi-phase initialization. They can be used directly, for example when creating module objects dynamically. Note that both ‘PyModule_FromDefAndSpec’ and ‘PyModule_ExecDef’ must be called to fully initialize a module. -- C Function: PyObject * PyModule_FromDefAndSpec (PyModuleDef *def, PyObject *spec) `Return value: New reference.' Create a new module object, given the definition in `module' and the ModuleSpec `spec'. This behaves like *note PyModule_FromDefAndSpec2(): 7ac. with `module_api_version' set to ‘PYTHON_API_VERSION’. New in version 3.5. -- C Function: PyObject * PyModule_FromDefAndSpec2 (PyModuleDef *def, PyObject *spec, int module_api_version) `Return value: New reference.' Create a new module object, given the definition in `module' and the ModuleSpec `spec', assuming the API version `module_api_version'. If that version does not match the version of the running interpreter, a *note RuntimeWarning: 2c0. is emitted. Note: Most uses of this function should be using *note PyModule_FromDefAndSpec(): 7ab. instead; only use this if you are sure you need it. New in version 3.5. -- C Function: int PyModule_ExecDef (PyObject *module, PyModuleDef *def) Process any execution slots (*note Py_mod_exec: 3c39.) given in `def'. New in version 3.5. -- C Function: int PyModule_SetDocString (PyObject *module, const char *docstring) Set the docstring for `module' to `docstring'. This function is called automatically when creating a module from ‘PyModuleDef’, using either ‘PyModule_Create’ or ‘PyModule_FromDefAndSpec’. New in version 3.5. -- C Function: int PyModule_AddFunctions (PyObject *module, PyMethodDef *functions) Add the functions from the ‘NULL’ terminated `functions' array to `module'. Refer to the *note PyMethodDef: e1b. documentation for details on individual entries (due to the lack of a shared module namespace, module level “functions” implemented in C typically receive the module as their first parameter, making them similar to instance methods on Python classes). This function is called automatically when creating a module from ‘PyModuleDef’, using either ‘PyModule_Create’ or ‘PyModule_FromDefAndSpec’. New in version 3.5.  File: python.info, Node: Support functions, Prev: Low-level module creation functions, Up: Initializing C modules 7.8.6.7 Support functions ......................... The module initialization function (if using single phase initialization) or a function called from a module execution slot (if using multi-phase initialization), can use the following functions to help initialize the module state: -- C Function: int PyModule_AddObject (PyObject *module, const char *name, PyObject *value) Add an object to `module' as `name'. This is a convenience function which can be used from the module’s initialization function. This steals a reference to `value' on success. Return ‘-1’ on error, ‘0’ on success. Note: Unlike other functions that steal references, ‘PyModule_AddObject()’ only decrements the reference count of `value' `on success'. This means that its return value must be checked, and calling code must *note Py_DECREF(): 266. `value' manually on error. Example usage: Py_INCREF(spam); if (PyModule_AddObject(module, "spam", spam) < 0) { Py_DECREF(module); Py_DECREF(spam); return NULL; } -- C Function: int PyModule_AddIntConstant (PyObject *module, const char *name, long value) Add an integer constant to `module' as `name'. This convenience function can be used from the module’s initialization function. Return ‘-1’ on error, ‘0’ on success. -- C Function: int PyModule_AddStringConstant (PyObject *module, const char *name, const char *value) Add a string constant to `module' as `name'. This convenience function can be used from the module’s initialization function. The string `value' must be ‘NULL’-terminated. Return ‘-1’ on error, ‘0’ on success. -- C Function: int PyModule_AddIntMacro (PyObject *module, macro) Add an int constant to `module'. The name and the value are taken from `macro'. For example ‘PyModule_AddIntMacro(module, AF_INET)’ adds the int constant `AF_INET' with the value of `AF_INET' to `module'. Return ‘-1’ on error, ‘0’ on success. -- C Function: int PyModule_AddStringMacro (PyObject *module, macro) Add a string constant to `module'.  File: python.info, Node: Module lookup, Prev: Initializing C modules, Up: Module Objects 7.8.6.8 Module lookup ..................... Single-phase initialization creates singleton modules that can be looked up in the context of the current interpreter. This allows the module object to be retrieved later with only a reference to the module definition. These functions will not work on modules created using multi-phase initialization, since multiple such modules can be created from a single definition. -- C Function: PyObject* PyState_FindModule (PyModuleDef *def) `Return value: Borrowed reference.' Returns the module object that was created from `def' for the current interpreter. This method requires that the module object has been attached to the interpreter state with *note PyState_AddModule(): 3c50. beforehand. In case the corresponding module object is not found or has not been attached to the interpreter state yet, it returns ‘NULL’. -- C Function: int PyState_AddModule (PyObject *module, PyModuleDef *def) Attaches the module object passed to the function to the interpreter state. This allows the module object to be accessible via *note PyState_FindModule(): 3c4f. Only effective on modules created using single-phase initialization. Python calls ‘PyState_AddModule’ automatically after importing a module, so it is unnecessary (but harmless) to call it from module initialization code. An explicit call is needed only if the module’s own init code subsequently calls ‘PyState_FindModule’. The function is mainly intended for implementing alternative import mechanisms (either by calling it directly, or by referring to its implementation for details of the required state updates). Return 0 on success or -1 on failure. New in version 3.3. -- C Function: int PyState_RemoveModule (PyModuleDef *def) Removes the module object created from `def' from the interpreter state. Return 0 on success or -1 on failure. New in version 3.3.  File: python.info, Node: Iterator Objects, Next: Descriptor Objects, Prev: Module Objects, Up: Other Objects 7.8.6.9 Iterator Objects ........................ Python provides two general-purpose iterator objects. The first, a sequence iterator, works with an arbitrary sequence supporting the *note __getitem__(): 27c. method. The second works with a callable object and a sentinel value, calling the callable for each item in the sequence, and ending the iteration when the sentinel value is returned. -- C Variable: PyTypeObject PySeqIter_Type Type object for iterator objects returned by *note PySeqIter_New(): 3c56. and the one-argument form of the *note iter(): d27. built-in function for built-in sequence types. -- C Function: int PySeqIter_Check (op) Return true if the type of `op' is *note PySeqIter_Type: 3c55. -- C Function: PyObject* PySeqIter_New (PyObject *seq) `Return value: New reference.' Return an iterator that works with a general sequence object, `seq'. The iteration ends when the sequence raises *note IndexError: e75. for the subscripting operation. -- C Variable: PyTypeObject PyCallIter_Type Type object for iterator objects returned by *note PyCallIter_New(): 3c59. and the two-argument form of the *note iter(): d27. built-in function. -- C Function: int PyCallIter_Check (op) Return true if the type of `op' is *note PyCallIter_Type: 3c58. -- C Function: PyObject* PyCallIter_New (PyObject *callable, PyObject *sentinel) `Return value: New reference.' Return a new iterator. The first parameter, `callable', can be any Python callable object that can be called with no parameters; each call to it should return the next item in the iteration. When `callable' returns a value equal to `sentinel', the iteration will be terminated.  File: python.info, Node: Descriptor Objects, Next: Slice Objects, Prev: Iterator Objects, Up: Other Objects 7.8.6.10 Descriptor Objects ........................... “Descriptors” are objects that describe some attribute of an object. They are found in the dictionary of type objects. -- C Variable: PyTypeObject PyProperty_Type The type object for the built-in descriptor types. -- C Function: PyObject* PyDescr_NewGetSet (PyTypeObject *type, struct PyGetSetDef *getset) `Return value: New reference.' -- C Function: PyObject* PyDescr_NewMember (PyTypeObject *type, struct PyMemberDef *meth) `Return value: New reference.' -- C Function: PyObject* PyDescr_NewMethod (PyTypeObject *type, struct PyMethodDef *meth) `Return value: New reference.' -- C Function: PyObject* PyDescr_NewWrapper (PyTypeObject *type, struct wrapperbase *wrapper, void *wrapped) `Return value: New reference.' -- C Function: PyObject* PyDescr_NewClassMethod (PyTypeObject *type, PyMethodDef *method) `Return value: New reference.' -- C Function: int PyDescr_IsData (PyObject *descr) Return true if the descriptor objects `descr' describes a data attribute, or false if it describes a method. `descr' must be a descriptor object; there is no error checking. -- C Function: PyObject* PyWrapper_New (PyObject *, PyObject *) `Return value: New reference.'  File: python.info, Node: Slice Objects, Next: Ellipsis Object, Prev: Descriptor Objects, Up: Other Objects 7.8.6.11 Slice Objects ...................... -- C Variable: PyTypeObject PySlice_Type The type object for slice objects. This is the same as *note slice: e04. in the Python layer. -- C Function: int PySlice_Check (PyObject *ob) Return true if `ob' is a slice object; `ob' must not be ‘NULL’. -- C Function: PyObject* PySlice_New (PyObject *start, PyObject *stop, PyObject *step) `Return value: New reference.' Return a new slice object with the given values. The `start', `stop', and `step' parameters are used as the values of the slice object attributes of the same names. Any of the values may be ‘NULL’, in which case the ‘None’ will be used for the corresponding attribute. Return ‘NULL’ if the new object could not be allocated. -- C Function: int PySlice_GetIndices (PyObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step) Retrieve the start, stop and step indices from the slice object `slice', assuming a sequence of length `length'. Treats indices greater than `length' as errors. Returns ‘0’ on success and ‘-1’ on error with no exception set (unless one of the indices was not *note None: 157. and failed to be converted to an integer, in which case ‘-1’ is returned with an exception set). You probably do not want to use this function. Changed in version 3.2: The parameter type for the `slice' parameter was ‘PySliceObject*’ before. -- C Function: int PySlice_GetIndicesEx (PyObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, Py_ssize_t *slicelength) Usable replacement for *note PySlice_GetIndices(): 3c6c. Retrieve the start, stop, and step indices from the slice object `slice' assuming a sequence of length `length', and store the length of the slice in `slicelength'. Out of bounds indices are clipped in a manner consistent with the handling of normal slices. Returns ‘0’ on success and ‘-1’ on error with exception set. Note: This function is considered not safe for resizable sequences. Its invocation should be replaced by a combination of *note PySlice_Unpack(): 42f. and *note PySlice_AdjustIndices(): 430. where if (PySlice_GetIndicesEx(slice, length, &start, &stop, &step, &slicelength) < 0) { // return error } is replaced by if (PySlice_Unpack(slice, &start, &stop, &step) < 0) { // return error } slicelength = PySlice_AdjustIndices(length, &start, &stop, step); Changed in version 3.2: The parameter type for the `slice' parameter was ‘PySliceObject*’ before. Changed in version 3.6.1: If ‘Py_LIMITED_API’ is not set or set to the value between ‘0x03050400’ and ‘0x03060000’ (not including) or ‘0x03060100’ or higher ‘PySlice_GetIndicesEx()’ is implemented as a macro using ‘PySlice_Unpack()’ and ‘PySlice_AdjustIndices()’. Arguments `start', `stop' and `step' are evaluated more than once. Deprecated since version 3.6.1: If ‘Py_LIMITED_API’ is set to the value less than ‘0x03050400’ or between ‘0x03060000’ and ‘0x03060100’ (not including) ‘PySlice_GetIndicesEx()’ is a deprecated function. -- C Function: int PySlice_Unpack (PyObject *slice, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step) Extract the start, stop and step data members from a slice object as C integers. Silently reduce values larger than ‘PY_SSIZE_T_MAX’ to ‘PY_SSIZE_T_MAX’, silently boost the start and stop values less than ‘PY_SSIZE_T_MIN’ to ‘PY_SSIZE_T_MIN’, and silently boost the step values less than ‘-PY_SSIZE_T_MAX’ to ‘-PY_SSIZE_T_MAX’. Return ‘-1’ on error, ‘0’ on success. New in version 3.6.1. -- C Function: Py_ssize_t PySlice_AdjustIndices (Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t step) Adjust start/end slice indices assuming a sequence of the specified length. Out of bounds indices are clipped in a manner consistent with the handling of normal slices. Return the length of the slice. Always successful. Doesn’t call Python code. New in version 3.6.1.  File: python.info, Node: Ellipsis Object, Next: MemoryView objects, Prev: Slice Objects, Up: Other Objects 7.8.6.12 Ellipsis Object ........................ -- C Variable: PyObject *Py_Ellipsis The Python ‘Ellipsis’ object. This object has no methods. It needs to be treated just like any other object with respect to reference counts. Like *note Py_None: 3844. it is a singleton object.  File: python.info, Node: MemoryView objects, Next: Weak Reference Objects<2>, Prev: Ellipsis Object, Up: Other Objects 7.8.6.13 MemoryView objects ........................... A *note memoryview: 25c. object exposes the C level *note buffer interface: 1291. as a Python object which can then be passed around like any other object. -- C Function: PyObject *PyMemoryView_FromObject (PyObject *obj) `Return value: New reference.' Create a memoryview object from an object that provides the buffer interface. If `obj' supports writable buffer exports, the memoryview object will be read/write, otherwise it may be either read-only or read/write at the discretion of the exporter. -- C Function: PyObject *PyMemoryView_FromMemory (char *mem, Py_ssize_t size, int flags) `Return value: New reference.' Create a memoryview object using `mem' as the underlying buffer. `flags' can be one of ‘PyBUF_READ’ or ‘PyBUF_WRITE’. New in version 3.3. -- C Function: PyObject *PyMemoryView_FromBuffer (Py_buffer *view) `Return value: New reference.' Create a memoryview object wrapping the given buffer structure `view'. For simple byte buffers, *note PyMemoryView_FromMemory(): ac9. is the preferred function. -- C Function: PyObject *PyMemoryView_GetContiguous (PyObject *obj, int buffertype, char order) `Return value: New reference.' Create a memoryview object to a *note contiguous: 1360. chunk of memory (in either ‘C’ or ‘F’ortran `order') from an object that defines the buffer interface. If memory is contiguous, the memoryview object points to the original memory. Otherwise, a copy is made and the memoryview points to a new bytes object. -- C Function: int PyMemoryView_Check (PyObject *obj) Return true if the object `obj' is a memoryview object. It is not currently allowed to create subclasses of *note memoryview: 25c. -- C Function: Py_buffer *PyMemoryView_GET_BUFFER (PyObject *mview) Return a pointer to the memoryview’s private copy of the exporter’s buffer. `mview' `must' be a memoryview instance; this macro doesn’t check its type, you must do it yourself or you will risk crashes. -- C Function: Py_buffer *PyMemoryView_GET_BASE (PyObject *mview) Return either a pointer to the exporting object that the memoryview is based on or ‘NULL’ if the memoryview has been created by one of the functions *note PyMemoryView_FromMemory(): ac9. or *note PyMemoryView_FromBuffer(): 3a75. `mview' `must' be a memoryview instance.  File: python.info, Node: Weak Reference Objects<2>, Next: Capsules<2>, Prev: MemoryView objects, Up: Other Objects 7.8.6.14 Weak Reference Objects ............................... Python supports `weak references' as first-class objects. There are two specific object types which directly implement weak references. The first is a simple reference object, and the second acts as a proxy for the original object as much as it can. -- C Function: int PyWeakref_Check (ob) Return true if `ob' is either a reference or proxy object. -- C Function: int PyWeakref_CheckRef (ob) Return true if `ob' is a reference object. -- C Function: int PyWeakref_CheckProxy (ob) Return true if `ob' is a proxy object. -- C Function: PyObject* PyWeakref_NewRef (PyObject *ob, PyObject *callback) `Return value: New reference.' Return a weak reference object for the object `ob'. This will always return a new reference, but is not guaranteed to create a new object; an existing reference object may be returned. The second parameter, `callback', can be a callable object that receives notification when `ob' is garbage collected; it should accept a single parameter, which will be the weak reference object itself. `callback' may also be ‘None’ or ‘NULL’. If `ob' is not a weakly-referencable object, or if `callback' is not callable, ‘None’, or ‘NULL’, this will return ‘NULL’ and raise *note TypeError: 192. -- C Function: PyObject* PyWeakref_NewProxy (PyObject *ob, PyObject *callback) `Return value: New reference.' Return a weak reference proxy object for the object `ob'. This will always return a new reference, but is not guaranteed to create a new object; an existing proxy object may be returned. The second parameter, `callback', can be a callable object that receives notification when `ob' is garbage collected; it should accept a single parameter, which will be the weak reference object itself. `callback' may also be ‘None’ or ‘NULL’. If `ob' is not a weakly-referencable object, or if `callback' is not callable, ‘None’, or ‘NULL’, this will return ‘NULL’ and raise *note TypeError: 192. -- C Function: PyObject* PyWeakref_GetObject (PyObject *ref) `Return value: Borrowed reference.' Return the referenced object from a weak reference, `ref'. If the referent is no longer live, returns ‘Py_None’. Note: This function returns a `borrowed reference' to the referenced object. This means that you should always call *note Py_INCREF(): 265. on the object except if you know that it cannot be destroyed while you are still using it. -- C Function: PyObject* PyWeakref_GET_OBJECT (PyObject *ref) `Return value: Borrowed reference.' Similar to *note PyWeakref_GetObject(): 3c7e, but implemented as a macro that does no error checking.  File: python.info, Node: Capsules<2>, Next: Generator Objects, Prev: Weak Reference Objects<2>, Up: Other Objects 7.8.6.15 Capsules ................. Refer to *note Providing a C API for an Extension Module: cf1. for more information on using these objects. New in version 3.1. -- C Type: PyCapsule This subtype of *note PyObject: 4ba. represents an opaque value, useful for C extension modules who need to pass an opaque value (as a ‘void*’ pointer) through Python code to other C code. It is often used to make a C function pointer defined in one module available to other modules, so the regular import mechanism can be used to access C APIs defined in dynamically loaded modules. -- C Type: PyCapsule_Destructor The type of a destructor callback for a capsule. Defined as: typedef void (*PyCapsule_Destructor)(PyObject *); See *note PyCapsule_New(): 386c. for the semantics of PyCapsule_Destructor callbacks. -- C Function: int PyCapsule_CheckExact (PyObject *p) Return true if its argument is a *note PyCapsule: c07. -- C Function: PyObject* PyCapsule_New (void *pointer, const char *name, PyCapsule_Destructor destructor) `Return value: New reference.' Create a *note PyCapsule: c07. encapsulating the `pointer'. The `pointer' argument may not be ‘NULL’. On failure, set an exception and return ‘NULL’. The `name' string may either be ‘NULL’ or a pointer to a valid C string. If non-‘NULL’, this string must outlive the capsule. (Though it is permitted to free it inside the `destructor'.) If the `destructor' argument is not ‘NULL’, it will be called with the capsule as its argument when it is destroyed. If this capsule will be stored as an attribute of a module, the `name' should be specified as ‘modulename.attributename’. This will enable other modules to import the capsule using *note PyCapsule_Import(): 386d. -- C Function: void* PyCapsule_GetPointer (PyObject *capsule, const char *name) Retrieve the `pointer' stored in the capsule. On failure, set an exception and return ‘NULL’. The `name' parameter must compare exactly to the name stored in the capsule. If the name stored in the capsule is ‘NULL’, the `name' passed in must also be ‘NULL’. Python uses the C function ‘strcmp()’ to compare capsule names. -- C Function: PyCapsule_Destructor PyCapsule_GetDestructor (PyObject *capsule) Return the current destructor stored in the capsule. On failure, set an exception and return ‘NULL’. It is legal for a capsule to have a ‘NULL’ destructor. This makes a ‘NULL’ return code somewhat ambiguous; use *note PyCapsule_IsValid(): cf0. or *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: void* PyCapsule_GetContext (PyObject *capsule) Return the current context stored in the capsule. On failure, set an exception and return ‘NULL’. It is legal for a capsule to have a ‘NULL’ context. This makes a ‘NULL’ return code somewhat ambiguous; use *note PyCapsule_IsValid(): cf0. or *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: const char* PyCapsule_GetName (PyObject *capsule) Return the current name stored in the capsule. On failure, set an exception and return ‘NULL’. It is legal for a capsule to have a ‘NULL’ name. This makes a ‘NULL’ return code somewhat ambiguous; use *note PyCapsule_IsValid(): cf0. or *note PyErr_Occurred(): 383f. to disambiguate. -- C Function: void* PyCapsule_Import (const char *name, int no_block) Import a pointer to a C object from a capsule attribute in a module. The `name' parameter should specify the full name to the attribute, as in ‘module.attribute’. The `name' stored in the capsule must match this string exactly. If `no_block' is true, import the module without blocking (using *note PyImport_ImportModuleNoBlock(): 9c1.). If `no_block' is false, import the module conventionally (using *note PyImport_ImportModule(): c73.). Return the capsule’s internal `pointer' on success. On failure, set an exception and return ‘NULL’. -- C Function: int PyCapsule_IsValid (PyObject *capsule, const char *name) Determines whether or not `capsule' is a valid capsule. A valid capsule is non-‘NULL’, passes *note PyCapsule_CheckExact(): 3c83, has a non-‘NULL’ pointer stored in it, and its internal name matches the `name' parameter. (See *note PyCapsule_GetPointer(): 3c84. for information on how capsule names are compared.) In other words, if *note PyCapsule_IsValid(): cf0. returns a true value, calls to any of the accessors (any function starting with ‘PyCapsule_Get()’) are guaranteed to succeed. Return a nonzero value if the object is valid and matches the name passed in. Return ‘0’ otherwise. This function will not fail. -- C Function: int PyCapsule_SetContext (PyObject *capsule, void *context) Set the context pointer inside `capsule' to `context'. Return ‘0’ on success. Return nonzero and set an exception on failure. -- C Function: int PyCapsule_SetDestructor (PyObject *capsule, PyCapsule_Destructor destructor) Set the destructor inside `capsule' to `destructor'. Return ‘0’ on success. Return nonzero and set an exception on failure. -- C Function: int PyCapsule_SetName (PyObject *capsule, const char *name) Set the name inside `capsule' to `name'. If non-‘NULL’, the name must outlive the capsule. If the previous `name' stored in the capsule was not ‘NULL’, no attempt is made to free it. Return ‘0’ on success. Return nonzero and set an exception on failure. -- C Function: int PyCapsule_SetPointer (PyObject *capsule, void *pointer) Set the void pointer inside `capsule' to `pointer'. The pointer may not be ‘NULL’. Return ‘0’ on success. Return nonzero and set an exception on failure.  File: python.info, Node: Generator Objects, Next: Coroutine Objects<2>, Prev: Capsules<2>, Up: Other Objects 7.8.6.16 Generator Objects .......................... Generator objects are what Python uses to implement generator iterators. They are normally created by iterating over a function that yields values, rather than explicitly calling *note PyGen_New(): 3c8f. or *note PyGen_NewWithQualName(): 3c90. -- C Type: PyGenObject The C structure used for generator objects. -- C Variable: PyTypeObject PyGen_Type The type object corresponding to generator objects. -- C Function: int PyGen_Check (PyObject *ob) Return true if `ob' is a generator object; `ob' must not be ‘NULL’. -- C Function: int PyGen_CheckExact (PyObject *ob) Return true if `ob'’s type is *note PyGen_Type: 3c92.; `ob' must not be ‘NULL’. -- C Function: PyObject* PyGen_New (PyFrameObject *frame) `Return value: New reference.' Create and return a new generator object based on the `frame' object. A reference to `frame' is stolen by this function. The argument must not be ‘NULL’. -- C Function: PyObject* PyGen_NewWithQualName (PyFrameObject *frame, PyObject *name, PyObject *qualname) `Return value: New reference.' Create and return a new generator object based on the `frame' object, with ‘__name__’ and ‘__qualname__’ set to `name' and `qualname'. A reference to `frame' is stolen by this function. The `frame' argument must not be ‘NULL’.  File: python.info, Node: Coroutine Objects<2>, Next: Context Variables Objects, Prev: Generator Objects, Up: Other Objects 7.8.6.17 Coroutine Objects .......................... New in version 3.5. Coroutine objects are what functions declared with an ‘async’ keyword return. -- C Type: PyCoroObject The C structure used for coroutine objects. -- C Variable: PyTypeObject PyCoro_Type The type object corresponding to coroutine objects. -- C Function: int PyCoro_CheckExact (PyObject *ob) Return true if `ob'’s type is *note PyCoro_Type: 3c98.; `ob' must not be ‘NULL’. -- C Function: PyObject* PyCoro_New (PyFrameObject *frame, PyObject *name, PyObject *qualname) `Return value: New reference.' Create and return a new coroutine object based on the `frame' object, with ‘__name__’ and ‘__qualname__’ set to `name' and `qualname'. A reference to `frame' is stolen by this function. The `frame' argument must not be ‘NULL’.  File: python.info, Node: Context Variables Objects, Next: DateTime Objects<2>, Prev: Coroutine Objects<2>, Up: Other Objects 7.8.6.18 Context Variables Objects .................................. Note Changed in version 3.7.1:: In Python 3.7.1 the signatures of all context variables C APIs were `changed' to use *note PyObject: 4ba. pointers instead of *note PyContext: 3c9d, *note PyContextVar: 3c9e, and *note PyContextToken: 3c9f, e.g.: // in 3.7.0: PyContext *PyContext_New(void); // in 3.7.1+: PyObject *PyContext_New(void); See bpo-34762(1) for more details. New in version 3.7. This section details the public C API for the *note contextvars: 25. module. -- C Type: PyContext The C structure used to represent a *note contextvars.Context: 21ab. object. -- C Type: PyContextVar The C structure used to represent a *note contextvars.ContextVar: 21a9. object. -- C Type: PyContextToken The C structure used to represent a ‘contextvars.Token’ object. -- C Variable: PyTypeObject PyContext_Type The type object representing the `context' type. -- C Variable: PyTypeObject PyContextVar_Type The type object representing the `context variable' type. -- C Variable: PyTypeObject PyContextToken_Type The type object representing the `context variable token' type. Type-check macros: -- C Function: int PyContext_CheckExact (PyObject *o) Return true if `o' is of type *note PyContext_Type: 3ca0. `o' must not be ‘NULL’. This function always succeeds. -- C Function: int PyContextVar_CheckExact (PyObject *o) Return true if `o' is of type *note PyContextVar_Type: 3ca1. `o' must not be ‘NULL’. This function always succeeds. -- C Function: int PyContextToken_CheckExact (PyObject *o) Return true if `o' is of type *note PyContextToken_Type: 3ca2. `o' must not be ‘NULL’. This function always succeeds. Context object management functions: -- C Function: PyObject *PyContext_New (void) `Return value: New reference.' Create a new empty context object. Returns ‘NULL’ if an error has occurred. -- C Function: PyObject *PyContext_Copy (PyObject *ctx) `Return value: New reference.' Create a shallow copy of the passed `ctx' context object. Returns ‘NULL’ if an error has occurred. -- C Function: PyObject *PyContext_CopyCurrent (void) `Return value: New reference.' Create a shallow copy of the current thread context. Returns ‘NULL’ if an error has occurred. -- C Function: int PyContext_Enter (PyObject *ctx) Set `ctx' as the current context for the current thread. Returns ‘0’ on success, and ‘-1’ on error. -- C Function: int PyContext_Exit (PyObject *ctx) Deactivate the `ctx' context and restore the previous context as the current context for the current thread. Returns ‘0’ on success, and ‘-1’ on error. -- C Function: int PyContext_ClearFreeList () Clear the context variable free list. Return the total number of freed items. This function always succeeds. Context variable functions: -- C Function: PyObject *PyContextVar_New (const char *name, PyObject *def) `Return value: New reference.' Create a new ‘ContextVar’ object. The `name' parameter is used for introspection and debug purposes. The `def' parameter may optionally specify the default value for the context variable. If an error has occurred, this function returns ‘NULL’. -- C Function: int PyContextVar_Get (PyObject *var, PyObject *default_value, PyObject **value) Get the value of a context variable. Returns ‘-1’ if an error has occurred during lookup, and ‘0’ if no error occurred, whether or not a value was found. If the context variable was found, `value' will be a pointer to it. If the context variable was `not' found, `value' will point to: - `default_value', if not ‘NULL’; - the default value of `var', if not ‘NULL’; - ‘NULL’ If the value was found, the function will create a new reference to it. -- C Function: PyObject *PyContextVar_Set (PyObject *var, PyObject *value) `Return value: New reference.' Set the value of `var' to `value' in the current context. Returns a pointer to a *note PyObject: 4ba. object, or ‘NULL’ if an error has occurred. -- C Function: int PyContextVar_Reset (PyObject *var, PyObject *token) Reset the state of the `var' context variable to that it was in before *note PyContextVar_Set(): 3cae. that returned the `token' was called. This function returns ‘0’ on success and ‘-1’ on error. ---------- Footnotes ---------- (1) https://bugs.python.org/issue34762  File: python.info, Node: DateTime Objects<2>, Prev: Context Variables Objects, Up: Other Objects 7.8.6.19 DateTime Objects ......................... Various date and time objects are supplied by the *note datetime: 31. module. Before using any of these functions, the header file ‘datetime.h’ must be included in your source (note that this is not included by ‘Python.h’), and the macro ‘PyDateTime_IMPORT’ must be invoked, usually as part of the module initialisation function. The macro puts a pointer to a C structure into a static variable, ‘PyDateTimeAPI’, that is used by the following macros. Macro for access to the UTC singleton: -- C Variable: PyObject* PyDateTime_TimeZone_UTC Returns the time zone singleton representing UTC, the same object as *note datetime.timezone.utc: 1599. New in version 3.7. Type-check macros: -- C Function: int PyDate_Check (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DateType’ or a subtype of ‘PyDateTime_DateType’. `ob' must not be ‘NULL’. -- C Function: int PyDate_CheckExact (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DateType’. `ob' must not be ‘NULL’. -- C Function: int PyDateTime_Check (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DateTimeType’ or a subtype of ‘PyDateTime_DateTimeType’. `ob' must not be ‘NULL’. -- C Function: int PyDateTime_CheckExact (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DateTimeType’. `ob' must not be ‘NULL’. -- C Function: int PyTime_Check (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_TimeType’ or a subtype of ‘PyDateTime_TimeType’. `ob' must not be ‘NULL’. -- C Function: int PyTime_CheckExact (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_TimeType’. `ob' must not be ‘NULL’. -- C Function: int PyDelta_Check (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DeltaType’ or a subtype of ‘PyDateTime_DeltaType’. `ob' must not be ‘NULL’. -- C Function: int PyDelta_CheckExact (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_DeltaType’. `ob' must not be ‘NULL’. -- C Function: int PyTZInfo_Check (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_TZInfoType’ or a subtype of ‘PyDateTime_TZInfoType’. `ob' must not be ‘NULL’. -- C Function: int PyTZInfo_CheckExact (PyObject *ob) Return true if `ob' is of type ‘PyDateTime_TZInfoType’. `ob' must not be ‘NULL’. Macros to create objects: -- C Function: PyObject* PyDate_FromDate (int year, int month, int day) `Return value: New reference.' Return a *note datetime.date: 193. object with the specified year, month and day. -- C Function: PyObject* PyDateTime_FromDateAndTime (int year, int month, int day, int hour, int minute, int second, int usecond) `Return value: New reference.' Return a *note datetime.datetime: 194. object with the specified year, month, day, hour, minute, second and microsecond. -- C Function: PyObject* PyDateTime_FromDateAndTimeAndFold (int year, int month, int day, int hour, int minute, int second, int usecond, int fold) `Return value: New reference.' Return a *note datetime.datetime: 194. object with the specified year, month, day, hour, minute, second, microsecond and fold. New in version 3.6. -- C Function: PyObject* PyTime_FromTime (int hour, int minute, int second, int usecond) `Return value: New reference.' Return a *note datetime.time: 4f3. object with the specified hour, minute, second and microsecond. -- C Function: PyObject* PyTime_FromTimeAndFold (int hour, int minute, int second, int usecond, int fold) `Return value: New reference.' Return a *note datetime.time: 4f3. object with the specified hour, minute, second, microsecond and fold. New in version 3.6. -- C Function: PyObject* PyDelta_FromDSU (int days, int seconds, int useconds) `Return value: New reference.' Return a *note datetime.timedelta: 195. object representing the given number of days, seconds and microseconds. Normalization is performed so that the resulting number of microseconds and seconds lie in the ranges documented for *note datetime.timedelta: 195. objects. -- C Function: PyObject* PyTimeZone_FromOffset (PyDateTime_DeltaType* offset) `Return value: New reference.' Return a *note datetime.timezone: a01. object with an unnamed fixed offset represented by the `offset' argument. New in version 3.7. -- C Function: PyObject* PyTimeZone_FromOffsetAndName (PyDateTime_DeltaType* offset, PyUnicode* name) `Return value: New reference.' Return a *note datetime.timezone: a01. object with a fixed offset represented by the `offset' argument and with tzname `name'. New in version 3.7. Macros to extract fields from date objects. The argument must be an instance of ‘PyDateTime_Date’, including subclasses (such as ‘PyDateTime_DateTime’). The argument must not be ‘NULL’, and the type is not checked: -- C Function: int PyDateTime_GET_YEAR (PyDateTime_Date *o) Return the year, as a positive int. -- C Function: int PyDateTime_GET_MONTH (PyDateTime_Date *o) Return the month, as an int from 1 through 12. -- C Function: int PyDateTime_GET_DAY (PyDateTime_Date *o) Return the day, as an int from 1 through 31. Macros to extract fields from datetime objects. The argument must be an instance of ‘PyDateTime_DateTime’, including subclasses. The argument must not be ‘NULL’, and the type is not checked: -- C Function: int PyDateTime_DATE_GET_HOUR (PyDateTime_DateTime *o) Return the hour, as an int from 0 through 23. -- C Function: int PyDateTime_DATE_GET_MINUTE (PyDateTime_DateTime *o) Return the minute, as an int from 0 through 59. -- C Function: int PyDateTime_DATE_GET_SECOND (PyDateTime_DateTime *o) Return the second, as an int from 0 through 59. -- C Function: int PyDateTime_DATE_GET_MICROSECOND (PyDateTime_DateTime *o) Return the microsecond, as an int from 0 through 999999. Macros to extract fields from time objects. The argument must be an instance of ‘PyDateTime_Time’, including subclasses. The argument must not be ‘NULL’, and the type is not checked: -- C Function: int PyDateTime_TIME_GET_HOUR (PyDateTime_Time *o) Return the hour, as an int from 0 through 23. -- C Function: int PyDateTime_TIME_GET_MINUTE (PyDateTime_Time *o) Return the minute, as an int from 0 through 59. -- C Function: int PyDateTime_TIME_GET_SECOND (PyDateTime_Time *o) Return the second, as an int from 0 through 59. -- C Function: int PyDateTime_TIME_GET_MICROSECOND (PyDateTime_Time *o) Return the microsecond, as an int from 0 through 999999. Macros to extract fields from time delta objects. The argument must be an instance of ‘PyDateTime_Delta’, including subclasses. The argument must not be ‘NULL’, and the type is not checked: -- C Function: int PyDateTime_DELTA_GET_DAYS (PyDateTime_Delta *o) Return the number of days, as an int from -999999999 to 999999999. New in version 3.3. -- C Function: int PyDateTime_DELTA_GET_SECONDS (PyDateTime_Delta *o) Return the number of seconds, as an int from 0 through 86399. New in version 3.3. -- C Function: int PyDateTime_DELTA_GET_MICROSECONDS (PyDateTime_Delta *o) Return the number of microseconds, as an int from 0 through 999999. New in version 3.3. Macros for the convenience of modules implementing the DB API: -- C Function: PyObject* PyDateTime_FromTimestamp (PyObject *args) `Return value: New reference.' Create and return a new *note datetime.datetime: 194. object given an argument tuple suitable for passing to *note datetime.datetime.fromtimestamp(): 156a. -- C Function: PyObject* PyDate_FromTimestamp (PyObject *args) `Return value: New reference.' Create and return a new *note datetime.date: 193. object given an argument tuple suitable for passing to *note datetime.date.fromtimestamp(): 1552.  File: python.info, Node: Initialization Finalization and Threads, Next: Python Initialization Configuration, Prev: Concrete Objects Layer, Up: Python/C API Reference Manual 7.9 Initialization, Finalization, and Threads ============================================= See also *note Python Initialization Configuration: 17d. * Menu: * Before Python Initialization:: * Global configuration variables:: * Initializing and finalizing the interpreter:: * Process-wide parameters:: * Thread State and the Global Interpreter Lock:: * Sub-interpreter support:: * Asynchronous Notifications:: * Profiling and Tracing:: * Advanced Debugger Support:: * Thread Local Storage Support::  File: python.info, Node: Before Python Initialization, Next: Global configuration variables, Up: Initialization Finalization and Threads 7.9.1 Before Python Initialization ---------------------------------- In an application embedding Python, the *note Py_Initialize(): 439. function must be called before using any other Python/C API functions; with the exception of a few functions and the *note global configuration variables: 3cd7. The following functions can be safely called before Python is initialized: * Configuration functions: * *note PyImport_AppendInittab(): 3848. * *note PyImport_ExtendInittab(): 39b7. * ‘PyInitFrozenExtensions()’ * *note PyMem_SetAllocator(): 3cd8. * *note PyMem_SetupDebugHooks(): 50a. * *note PyObject_SetArenaAllocator(): 3cd9. * *note Py_SetPath(): 273. * *note Py_SetProgramName(): 1031. * *note Py_SetPythonHome(): 3cda. * *note Py_SetStandardStreamEncoding(): 925. * *note PySys_AddWarnOption(): 4b3. * *note PySys_AddXOption(): 399d. * *note PySys_ResetWarnOptions(): 3996. * Informative functions: * *note Py_IsInitialized(): 3901. * *note PyMem_GetAllocator(): 3cdb. * *note PyObject_GetArenaAllocator(): 3cdc. * *note Py_GetBuildInfo(): d9a. * *note Py_GetCompiler(): 3cdd. * *note Py_GetCopyright(): 3cde. * *note Py_GetPlatform(): 3cdf. * *note Py_GetVersion(): 3ce0. * Utilities: * *note Py_DecodeLocale(): 43c. * Memory allocators: * *note PyMem_RawMalloc(): 96d. * *note PyMem_RawRealloc(): 96e. * *note PyMem_RawCalloc(): 7a5. * *note PyMem_RawFree(): 398f. Note: The following functions `should not be called' before *note Py_Initialize(): 439.: *note Py_EncodeLocale(): 43d, *note Py_GetPath(): 38fe, *note Py_GetPrefix(): 38ff, *note Py_GetExecPrefix(): 3900, *note Py_GetProgramFullPath(): 275, *note Py_GetPythonHome(): 3ce1, *note Py_GetProgramName(): 276. and *note PyEval_InitThreads(): c12.  File: python.info, Node: Global configuration variables, Next: Initializing and finalizing the interpreter, Prev: Before Python Initialization, Up: Initialization Finalization and Threads 7.9.2 Global configuration variables ------------------------------------ Python has variables for the global configuration to control different features and options. By default, these flags are controlled by *note command line options: fd0. When a flag is set by an option, the value of the flag is the number of times that the option was set. For example, ‘-b’ sets *note Py_BytesWarningFlag: 4b4. to 1 and ‘-bb’ sets *note Py_BytesWarningFlag: 4b4. to 2. -- C Variable: int Py_BytesWarningFlag Issue a warning when comparing *note bytes: 331. or *note bytearray: 332. with *note str: 330. or *note bytes: 331. with *note int: 184. Issue an error if greater or equal to ‘2’. Set by the *note -b: 415. option. -- C Variable: int Py_DebugFlag Turn on parser debugging output (for expert only, depending on compilation options). Set by the *note -d: fda. option and the *note PYTHONDEBUG: fdb. environment variable. -- C Variable: int Py_DontWriteBytecodeFlag If set to non-zero, Python won’t try to write ‘.pyc’ files on the import of source modules. Set by the *note -B: d38. option and the *note PYTHONDONTWRITEBYTECODE: d39. environment variable. -- C Variable: int Py_FrozenFlag Suppress error messages when calculating the module search path in *note Py_GetPath(): 38fe. Private flag used by ‘_freeze_importlib’ and ‘frozenmain’ programs. -- C Variable: int Py_HashRandomizationFlag Set to ‘1’ if the *note PYTHONHASHSEED: 9c5. environment variable is set to a non-empty string. If the flag is non-zero, read the *note PYTHONHASHSEED: 9c5. environment variable to initialize the secret hash seed. -- C Variable: int Py_IgnoreEnvironmentFlag Ignore all ‘PYTHON*’ environment variables, e.g. *note PYTHONPATH: 953. and *note PYTHONHOME: 4d6, that might be set. Set by the *note -E: fdc. and *note -I: fd2. options. -- C Variable: int Py_InspectFlag When a script is passed as first argument or the *note -c: e9e. option is used, enter interactive mode after executing the script or the command, even when *note sys.stdin: 30d. does not appear to be a terminal. Set by the *note -i: e1f. option and the *note PYTHONINSPECT: e1e. environment variable. -- C Variable: int Py_InteractiveFlag Set by the *note -i: e1f. option. -- C Variable: int Py_IsolatedFlag Run Python in isolated mode. In isolated mode *note sys.path: 488. contains neither the script’s directory nor the user’s site-packages directory. Set by the *note -I: fd2. option. New in version 3.4. -- C Variable: int Py_LegacyWindowsFSEncodingFlag If the flag is non-zero, use the ‘mbcs’ encoding instead of the UTF-8 encoding for the filesystem encoding. Set to ‘1’ if the *note PYTHONLEGACYWINDOWSFSENCODING: 4f7. environment variable is set to a non-empty string. See PEP 529(1) for more details. *note Availability: ffb.: Windows. -- C Variable: int Py_LegacyWindowsStdioFlag If the flag is non-zero, use *note io.FileIO: ca4. instead of ‘WindowsConsoleIO’ for *note sys: fd. standard streams. Set to ‘1’ if the *note PYTHONLEGACYWINDOWSSTDIO: 4fa. environment variable is set to a non-empty string. See PEP 528(2) for more details. *note Availability: ffb.: Windows. -- C Variable: int Py_NoSiteFlag Disable the import of the module *note site: eb. and the site-dependent manipulations of *note sys.path: 488. that it entails. Also disable these manipulations if *note site: eb. is explicitly imported later (call *note site.main(): fe2. if you want them to be triggered). Set by the *note -S: b24. option. -- C Variable: int Py_NoUserSiteDirectory Don’t add the *note user site-packages directory: fe1. to *note sys.path: 488. Set by the *note -s: d15. and *note -I: fd2. options, and the *note PYTHONNOUSERSITE: d16. environment variable. -- C Variable: int Py_OptimizeFlag Set by the *note -O: 68b. option and the *note PYTHONOPTIMIZE: fde. environment variable. -- C Variable: int Py_QuietFlag Don’t display the copyright and version messages even in interactive mode. Set by the *note -q: fdf. option. New in version 3.2. -- C Variable: int Py_UnbufferedStdioFlag Force the stdout and stderr streams to be unbuffered. Set by the *note -u: fe3. option and the *note PYTHONUNBUFFERED: fe4. environment variable. -- C Variable: int Py_VerboseFlag Print a message each time a module is initialized, showing the place (filename or built-in module) from which it is loaded. If greater or equal to ‘2’, print a message for each file that is checked for when searching for a module. Also provides information on module cleanup at exit. Set by the *note -v: d88. option and the *note PYTHONVERBOSE: fe5. environment variable. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0529 (2) https://www.python.org/dev/peps/pep-0528  File: python.info, Node: Initializing and finalizing the interpreter, Next: Process-wide parameters, Prev: Global configuration variables, Up: Initialization Finalization and Threads 7.9.3 Initializing and finalizing the interpreter ------------------------------------------------- -- C Function: void Py_Initialize () Initialize the Python interpreter. In an application embedding Python, this should be called before using any other Python/C API functions; see *note Before Python Initialization: 43a. for the few exceptions. This initializes the table of loaded modules (‘sys.modules’), and creates the fundamental modules *note builtins: 13, *note __main__: 1. and *note sys: fd. It also initializes the module search path (‘sys.path’). It does not set ‘sys.argv’; use *note PySys_SetArgvEx(): bfa. for that. This is a no-op when called for a second time (without calling *note Py_FinalizeEx(): 5c9. first). There is no return value; it is a fatal error if the initialization fails. Note: On Windows, changes the console mode from ‘O_TEXT’ to ‘O_BINARY’, which will also affect non-Python uses of the console using the C Runtime. -- C Function: void Py_InitializeEx (int initsigs) This function works like *note Py_Initialize(): 439. if `initsigs' is ‘1’. If `initsigs' is ‘0’, it skips initialization registration of signal handlers, which might be useful when Python is embedded. -- C Function: int Py_IsInitialized () Return true (nonzero) when the Python interpreter has been initialized, false (zero) if not. After *note Py_FinalizeEx(): 5c9. is called, this returns false until *note Py_Initialize(): 439. is called again. -- C Function: int Py_FinalizeEx () Undo all initializations made by *note Py_Initialize(): 439. and subsequent use of Python/C API functions, and destroy all sub-interpreters (see *note Py_NewInterpreter(): 3cf1. below) that were created and not yet destroyed since the last call to *note Py_Initialize(): 439. Ideally, this frees all memory allocated by the Python interpreter. This is a no-op when called for a second time (without calling *note Py_Initialize(): 439. again first). Normally the return value is ‘0’. If there were errors during finalization (flushing buffered data), ‘-1’ is returned. This function is provided for a number of reasons. An embedding application might want to restart Python without having to restart the application itself. An application that has loaded the Python interpreter from a dynamically loadable library (or DLL) might want to free all memory allocated by Python before unloading the DLL. During a hunt for memory leaks in an application a developer might want to free all memory allocated by Python before exiting from the application. `Bugs and caveats:' The destruction of modules and objects in modules is done in random order; this may cause destructors (*note __del__(): 91f. methods) to fail when they depend on other objects (even functions) or modules. Dynamically loaded extension modules loaded by Python are not unloaded. Small amounts of memory allocated by the Python interpreter may not be freed (if you find a leak, please report it). Memory tied up in circular references between objects is not freed. Some memory allocated by extension modules may not be freed. Some extensions may not work properly if their initialization routine is called more than once; this can happen if an application calls *note Py_Initialize(): 439. and *note Py_FinalizeEx(): 5c9. more than once. Raises an *note auditing event: fd1. ‘cpython._PySys_ClearAuditHooks’ with no arguments. New in version 3.6. -- C Function: void Py_Finalize () This is a backwards-compatible version of *note Py_FinalizeEx(): 5c9. that disregards the return value.  File: python.info, Node: Process-wide parameters, Next: Thread State and the Global Interpreter Lock, Prev: Initializing and finalizing the interpreter, Up: Initialization Finalization and Threads 7.9.4 Process-wide parameters ----------------------------- -- C Function: int Py_SetStandardStreamEncoding (const char *encoding, const char *errors) This function should be called before *note Py_Initialize(): 439, if it is called at all. It specifies which encoding and error handling to use with standard IO, with the same meanings as in *note str.encode(): c37. It overrides *note PYTHONIOENCODING: 92f. values, and allows embedding code to control IO encoding when the environment variable does not work. `encoding' and/or `errors' may be ‘NULL’ to use *note PYTHONIOENCODING: 92f. and/or default values (depending on other settings). Note that *note sys.stderr: 30f. always uses the “backslashreplace” error handler, regardless of this (or any other) setting. If *note Py_FinalizeEx(): 5c9. is called, this function will need to be called again in order to affect subsequent calls to *note Py_Initialize(): 439. Returns ‘0’ if successful, a nonzero value on error (e.g. calling after the interpreter has already been initialized). New in version 3.4. -- C Function: void Py_SetProgramName (const wchar_t *name) This function should be called before *note Py_Initialize(): 439. is called for the first time, if it is called at all. It tells the interpreter the value of the ‘argv[0]’ argument to the ‘main()’ function of the program (converted to wide characters). This is used by *note Py_GetPath(): 38fe. and some other functions below to find the Python run-time libraries relative to the interpreter executable. The default value is ‘'python'’. The argument should point to a zero-terminated wide character string in static storage whose contents will not change for the duration of the program’s execution. No code in the Python interpreter will change the contents of this storage. Use *note Py_DecodeLocale(): 43c. to decode a bytes string to get a ‘wchar_*’ string. -- C Function: wchar* Py_GetProgramName () Return the program name set with *note Py_SetProgramName(): 1031, or the default. The returned string points into static storage; the caller should not modify its value. -- C Function: wchar_t* Py_GetPrefix () Return the `prefix' for installed platform-independent files. This is derived through a number of complicated rules from the program name set with *note Py_SetProgramName(): 1031. and some environment variables; for example, if the program name is ‘'/usr/local/bin/python'’, the prefix is ‘'/usr/local'’. The returned string points into static storage; the caller should not modify its value. This corresponds to the ‘prefix’ variable in the top-level ‘Makefile’ and the ‘--prefix’ argument to the ‘configure’ script at build time. The value is available to Python code as ‘sys.prefix’. It is only useful on Unix. See also the next function. -- C Function: wchar_t* Py_GetExecPrefix () Return the `exec-prefix' for installed platform-`dependent' files. This is derived through a number of complicated rules from the program name set with *note Py_SetProgramName(): 1031. and some environment variables; for example, if the program name is ‘'/usr/local/bin/python'’, the exec-prefix is ‘'/usr/local'’. The returned string points into static storage; the caller should not modify its value. This corresponds to the ‘exec_prefix’ variable in the top-level ‘Makefile’ and the ‘--exec-prefix’ argument to the ‘configure’ script at build time. The value is available to Python code as ‘sys.exec_prefix’. It is only useful on Unix. Background: The exec-prefix differs from the prefix when platform dependent files (such as executables and shared libraries) are installed in a different directory tree. In a typical installation, platform dependent files may be installed in the ‘/usr/local/plat’ subtree while platform independent may be installed in ‘/usr/local’. Generally speaking, a platform is a combination of hardware and software families, e.g. Sparc machines running the Solaris 2.x operating system are considered the same platform, but Intel machines running Solaris 2.x are another platform, and Intel machines running Linux are yet another platform. Different major revisions of the same operating system generally also form different platforms. Non-Unix operating systems are a different story; the installation strategies on those systems are so different that the prefix and exec-prefix are meaningless, and set to the empty string. Note that compiled Python bytecode files are platform independent (but not independent from the Python version by which they were compiled!). System administrators will know how to configure the ‘mount’ or ‘automount’ programs to share ‘/usr/local’ between platforms while having ‘/usr/local/plat’ be a different filesystem for each platform. -- C Function: wchar_t* Py_GetProgramFullPath () Return the full program name of the Python executable; this is computed as a side-effect of deriving the default module search path from the program name (set by *note Py_SetProgramName(): 1031. above). The returned string points into static storage; the caller should not modify its value. The value is available to Python code as ‘sys.executable’. -- C Function: wchar_t* Py_GetPath () Return the default module search path; this is computed from the program name (set by *note Py_SetProgramName(): 1031. above) and some environment variables. The returned string consists of a series of directory names separated by a platform dependent delimiter character. The delimiter character is ‘':'’ on Unix and Mac OS X, ‘';'’ on Windows. The returned string points into static storage; the caller should not modify its value. The list *note sys.path: 488. is initialized with this value on interpreter startup; it can be (and usually is) modified later to change the search path for loading modules. -- C Function: void Py_SetPath (const wchar_t *) Set the default module search path. If this function is called before *note Py_Initialize(): 439, then *note Py_GetPath(): 38fe. won’t attempt to compute a default search path but uses the one provided instead. This is useful if Python is embedded by an application that has full knowledge of the location of all modules. The path components should be separated by the platform dependent delimiter character, which is ‘':'’ on Unix and Mac OS X, ‘';'’ on Windows. This also causes *note sys.executable: 274. to be set to the program full path (see *note Py_GetProgramFullPath(): 275.) and for *note sys.prefix: 3322. and *note sys.exec_prefix: 3323. to be empty. It is up to the caller to modify these if required after calling *note Py_Initialize(): 439. Use *note Py_DecodeLocale(): 43c. to decode a bytes string to get a ‘wchar_*’ string. The path argument is copied internally, so the caller may free it after the call completes. Changed in version 3.8: The program full path is now used for *note sys.executable: 274, instead of the program name. -- C Function: const char* Py_GetVersion () Return the version of this Python interpreter. This is a string that looks something like "3.0a5+ (py3k:63103M, May 12 2008, 00:53:55) \n[GCC 4.2.3]" The first word (up to the first space character) is the current Python version; the first three characters are the major and minor version separated by a period. The returned string points into static storage; the caller should not modify its value. The value is available to Python code as *note sys.version: 5d3. -- C Function: const char* Py_GetPlatform () Return the platform identifier for the current platform. On Unix, this is formed from the “official” name of the operating system, converted to lower case, followed by the major revision number; e.g., for Solaris 2.x, which is also known as SunOS 5.x, the value is ‘'sunos5'’. On Mac OS X, it is ‘'darwin'’. On Windows, it is ‘'win'’. The returned string points into static storage; the caller should not modify its value. The value is available to Python code as ‘sys.platform’. -- C Function: const char* Py_GetCopyright () Return the official copyright string for the current Python version, for example ‘'Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam'’ The returned string points into static storage; the caller should not modify its value. The value is available to Python code as ‘sys.copyright’. -- C Function: const char* Py_GetCompiler () Return an indication of the compiler used to build the current Python version, in square brackets, for example: "[GCC 2.7.2.2]" The returned string points into static storage; the caller should not modify its value. The value is available to Python code as part of the variable ‘sys.version’. -- C Function: const char* Py_GetBuildInfo () Return information about the sequence number and build date and time of the current Python interpreter instance, for example "#67, Aug 1 1997, 22:34:28" The returned string points into static storage; the caller should not modify its value. The value is available to Python code as part of the variable ‘sys.version’. -- C Function: void PySys_SetArgvEx (int argc, wchar_t **argv, int updatepath) Set *note sys.argv: bfb. based on `argc' and `argv'. These parameters are similar to those passed to the program’s ‘main()’ function with the difference that the first entry should refer to the script file to be executed rather than the executable hosting the Python interpreter. If there isn’t a script that will be run, the first entry in `argv' can be an empty string. If this function fails to initialize *note sys.argv: bfb, a fatal condition is signalled using *note Py_FatalError(): 39a2. If `updatepath' is zero, this is all the function does. If `updatepath' is non-zero, the function also modifies *note sys.path: 488. according to the following algorithm: - If the name of an existing script is passed in ‘argv[0]’, the absolute path of the directory where the script is located is prepended to *note sys.path: 488. - Otherwise (that is, if `argc' is ‘0’ or ‘argv[0]’ doesn’t point to an existing file name), an empty string is prepended to *note sys.path: 488, which is the same as prepending the current working directory (‘"."’). Use *note Py_DecodeLocale(): 43c. to decode a bytes string to get a ‘wchar_*’ string. Note: It is recommended that applications embedding the Python interpreter for purposes other than executing a single script pass ‘0’ as `updatepath', and update *note sys.path: 488. themselves if desired. See CVE-2008-5983(1). On versions before 3.1.3, you can achieve the same effect by manually popping the first *note sys.path: 488. element after having called *note PySys_SetArgv(): cec, for example using: PyRun_SimpleString("import sys; sys.path.pop(0)\n"); New in version 3.1.3. -- C Function: void PySys_SetArgv (int argc, wchar_t **argv) This function works like *note PySys_SetArgvEx(): bfa. with `updatepath' set to ‘1’ unless the ‘python’ interpreter was started with the *note -I: fd2. Use *note Py_DecodeLocale(): 43c. to decode a bytes string to get a ‘wchar_*’ string. Changed in version 3.4: The `updatepath' value depends on *note -I: fd2. -- C Function: void Py_SetPythonHome (const wchar_t *home) Set the default “home” directory, that is, the location of the standard Python libraries. See *note PYTHONHOME: 4d6. for the meaning of the argument string. The argument should point to a zero-terminated character string in static storage whose contents will not change for the duration of the program’s execution. No code in the Python interpreter will change the contents of this storage. Use *note Py_DecodeLocale(): 43c. to decode a bytes string to get a ‘wchar_*’ string. -- C Function: w_char* Py_GetPythonHome () Return the default “home”, that is, the value set by a previous call to *note Py_SetPythonHome(): 3cda, or the value of the *note PYTHONHOME: 4d6. environment variable if it is set. ---------- Footnotes ---------- (1) https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983  File: python.info, Node: Thread State and the Global Interpreter Lock, Next: Sub-interpreter support, Prev: Process-wide parameters, Up: Initialization Finalization and Threads 7.9.5 Thread State and the Global Interpreter Lock -------------------------------------------------- The Python interpreter is not fully thread-safe. In order to support multi-threaded Python programs, there’s a global lock, called the *note global interpreter lock: 506. or *note GIL: bea, that must be held by the current thread before it can safely access Python objects. Without the lock, even the simplest operations could cause problems in a multi-threaded program: for example, when two threads simultaneously increment the reference count of the same object, the reference count could end up being incremented only once instead of twice. Therefore, the rule exists that only the thread that has acquired the *note GIL: bea. may operate on Python objects or call Python/C API functions. In order to emulate concurrency of execution, the interpreter regularly tries to switch threads (see *note sys.setswitchinterval(): beb.). The lock is also released around potentially blocking I/O operations like reading or writing a file, so that other Python threads can run in the meantime. The Python interpreter keeps some thread-specific bookkeeping information inside a data structure called *note PyThreadState: 3cf5. There’s also one global variable pointing to the current *note PyThreadState: 3cf5.: it can be retrieved using *note PyThreadState_Get(): 3cf6. * Menu: * Releasing the GIL from extension code:: * Non-Python created threads:: * Cautions about fork(): Cautions about fork. * High-level API:: * Low-level API::  File: python.info, Node: Releasing the GIL from extension code, Next: Non-Python created threads, Up: Thread State and the Global Interpreter Lock 7.9.5.1 Releasing the GIL from extension code ............................................. Most extension code manipulating the *note GIL: bea. has the following simple structure: Save the thread state in a local variable. Release the global interpreter lock. ... Do some blocking I/O operation ... Reacquire the global interpreter lock. Restore the thread state from the local variable. This is so common that a pair of macros exists to simplify it: Py_BEGIN_ALLOW_THREADS ... Do some blocking I/O operation ... Py_END_ALLOW_THREADS The *note Py_BEGIN_ALLOW_THREADS: 3866. macro opens a new block and declares a hidden local variable; the *note Py_END_ALLOW_THREADS: 2b5. macro closes the block. The block above expands to the following code: PyThreadState *_save; _save = PyEval_SaveThread(); ... Do some blocking I/O operation ... PyEval_RestoreThread(_save); Here is how these functions work: the global interpreter lock is used to protect the pointer to the current thread state. When releasing the lock and saving the thread state, the current thread state pointer must be retrieved before the lock is released (since another thread could immediately acquire the lock and store its own thread state in the global variable). Conversely, when acquiring the lock and restoring the thread state, the lock must be acquired before storing the thread state pointer. Note: Calling system I/O functions is the most common use case for releasing the GIL, but it can also be useful before calling long-running computations which don’t need access to Python objects, such as compression or cryptographic functions operating over memory buffers. For example, the standard *note zlib: 144. and *note hashlib: 8d. modules release the GIL when compressing or hashing data.  File: python.info, Node: Non-Python created threads, Next: Cautions about fork, Prev: Releasing the GIL from extension code, Up: Thread State and the Global Interpreter Lock 7.9.5.2 Non-Python created threads .................................. When threads are created using the dedicated Python APIs (such as the *note threading: 109. module), a thread state is automatically associated to them and the code showed above is therefore correct. However, when threads are created from C (for example by a third-party library with its own thread management), they don’t hold the GIL, nor is there a thread state structure for them. If you need to call Python code from these threads (often this will be part of a callback API provided by the aforementioned third-party library), you must first register these threads with the interpreter by creating a thread state data structure, then acquiring the GIL, and finally storing their thread state pointer, before you can start using the Python/C API. When you are done, you should reset the thread state pointer, release the GIL, and finally free the thread state data structure. The *note PyGILState_Ensure(): 2b6. and *note PyGILState_Release(): 3cfa. functions do all of the above automatically. The typical idiom for calling into Python from a C thread is: PyGILState_STATE gstate; gstate = PyGILState_Ensure(); /* Perform Python actions here. */ result = CallSomeFunction(); /* evaluate result or handle exception */ /* Release the thread. No Python API allowed beyond this point. */ PyGILState_Release(gstate); Note that the ‘PyGILState_*()’ functions assume there is only one global interpreter (created automatically by *note Py_Initialize(): 439.). Python supports the creation of additional interpreters (using *note Py_NewInterpreter(): 3cf1.), but mixing multiple interpreters and the ‘PyGILState_*()’ API is unsupported.  File: python.info, Node: Cautions about fork, Next: High-level API, Prev: Non-Python created threads, Up: Thread State and the Global Interpreter Lock 7.9.5.3 Cautions about fork() ............................. Another important thing to note about threads is their behaviour in the face of the C ‘fork()’ call. On most systems with ‘fork()’, after a process forks only the thread that issued the fork will exist. This has a concrete impact both on how locks must be handled and on all stored state in CPython’s runtime. The fact that only the “current” thread remains means any locks held by other threads will never be released. Python solves this for *note os.fork(): 961. by acquiring the locks it uses internally before the fork, and releasing them afterwards. In addition, it resets any *note Lock Objects: 204d. in the child. When extending or embedding Python, there is no way to inform Python of additional (non-Python) locks that need to be acquired before or reset after a fork. OS facilities such as ‘pthread_atfork()’ would need to be used to accomplish the same thing. Additionally, when extending or embedding Python, calling ‘fork()’ directly rather than through *note os.fork(): 961. (and returning to or calling into Python) may result in a deadlock by one of Python’s internal locks being held by a thread that is defunct after the fork. *note PyOS_AfterFork_Child(): 2cd. tries to reset the necessary locks, but is not always able to. The fact that all other threads go away also means that CPython’s runtime state there must be cleaned up properly, which *note os.fork(): 961. does. This means finalizing all other *note PyThreadState: 3cf5. objects belonging to the current interpreter and all other *note PyInterpreterState: 2c2. objects. Due to this and the special nature of the *note “main” interpreter: 398b, ‘fork()’ should only be called in that interpreter’s “main” thread, where the CPython global runtime was originally initialized. The only exception is if ‘exec()’ will be called immediately after.  File: python.info, Node: High-level API, Next: Low-level API, Prev: Cautions about fork, Up: Thread State and the Global Interpreter Lock 7.9.5.4 High-level API ...................... These are the most commonly used types and functions when writing C extension code, or when embedding the Python interpreter: -- C Type: PyInterpreterState This data structure represents the state shared by a number of cooperating threads. Threads belonging to the same interpreter share their module administration and a few other internal items. There are no public members in this structure. Threads belonging to different interpreters initially share nothing, except process state like available memory, open file descriptors and such. The global interpreter lock is also shared by all threads, regardless of to which interpreter they belong. -- C Type: PyThreadState This data structure represents the state of a single thread. The only public data member is ‘interp’ (*note PyInterpreterState *: 2c2.), which points to this thread’s interpreter state. -- C Function: void PyEval_InitThreads () Initialize and acquire the global interpreter lock. It should be called in the main thread before creating a second thread or engaging in any other thread operations such as ‘PyEval_ReleaseThread(tstate)’. It is not needed before calling *note PyEval_SaveThread(): c11. or *note PyEval_RestoreThread(): 2b4. This is a no-op when called for a second time. Changed in version 3.7: This function is now called by *note Py_Initialize(): 439, so you don’t have to call it yourself anymore. Changed in version 3.2: This function cannot be called before *note Py_Initialize(): 439. anymore. -- C Function: int PyEval_ThreadsInitialized () Returns a non-zero value if *note PyEval_InitThreads(): c12. has been called. This function can be called without holding the GIL, and therefore can be used to avoid calls to the locking API when running single-threaded. Changed in version 3.7: The *note GIL: bea. is now initialized by *note Py_Initialize(): 439. -- C Function: PyThreadState* PyEval_SaveThread () Release the global interpreter lock (if it has been created) and reset the thread state to ‘NULL’, returning the previous thread state (which is not ‘NULL’). If the lock has been created, the current thread must have acquired it. -- C Function: void PyEval_RestoreThread (PyThreadState *tstate) Acquire the global interpreter lock (if it has been created) and set the thread state to `tstate', which must not be ‘NULL’. If the lock has been created, the current thread must not have acquired it, otherwise deadlock ensues. Note: Calling this function from a thread when the runtime is finalizing will terminate the thread, even if the thread was not created by Python. You can use ‘_Py_IsFinalizing()’ or *note sys.is_finalizing(): 762. to check if the interpreter is in process of being finalized before calling this function to avoid unwanted termination. -- C Function: PyThreadState* PyThreadState_Get () Return the current thread state. The global interpreter lock must be held. When the current thread state is ‘NULL’, this issues a fatal error (so that the caller needn’t check for ‘NULL’). -- C Function: PyThreadState* PyThreadState_Swap (PyThreadState *tstate) Swap the current thread state with the thread state given by the argument `tstate', which may be ‘NULL’. The global interpreter lock must be held and is not released. The following functions use thread-local storage, and are not compatible with sub-interpreters: -- C Function: PyGILState_STATE PyGILState_Ensure () Ensure that the current thread is ready to call the Python C API regardless of the current state of Python, or of the global interpreter lock. This may be called as many times as desired by a thread as long as each call is matched with a call to *note PyGILState_Release(): 3cfa. In general, other thread-related APIs may be used between *note PyGILState_Ensure(): 2b6. and *note PyGILState_Release(): 3cfa. calls as long as the thread state is restored to its previous state before the Release(). For example, normal usage of the *note Py_BEGIN_ALLOW_THREADS: 3866. and *note Py_END_ALLOW_THREADS: 2b5. macros is acceptable. The return value is an opaque “handle” to the thread state when *note PyGILState_Ensure(): 2b6. was called, and must be passed to *note PyGILState_Release(): 3cfa. to ensure Python is left in the same state. Even though recursive calls are allowed, these handles `cannot' be shared - each unique call to *note PyGILState_Ensure(): 2b6. must save the handle for its call to *note PyGILState_Release(): 3cfa. When the function returns, the current thread will hold the GIL and be able to call arbitrary Python code. Failure is a fatal error. Note: Calling this function from a thread when the runtime is finalizing will terminate the thread, even if the thread was not created by Python. You can use ‘_Py_IsFinalizing()’ or *note sys.is_finalizing(): 762. to check if the interpreter is in process of being finalized before calling this function to avoid unwanted termination. -- C Function: void PyGILState_Release (PyGILState_STATE) Release any resources previously acquired. After this call, Python’s state will be the same as it was prior to the corresponding *note PyGILState_Ensure(): 2b6. call (but generally this state will be unknown to the caller, hence the use of the GILState API). Every call to *note PyGILState_Ensure(): 2b6. must be matched by a call to *note PyGILState_Release(): 3cfa. on the same thread. -- C Function: PyThreadState* PyGILState_GetThisThreadState () Get the current thread state for this thread. May return ‘NULL’ if no GILState API has been used on the current thread. Note that the main thread always has such a thread-state, even if no auto-thread-state call has been made on the main thread. This is mainly a helper/diagnostic function. -- C Function: int PyGILState_Check () Return ‘1’ if the current thread is holding the GIL and ‘0’ otherwise. This function can be called from any thread at any time. Only if it has had its Python thread state initialized and currently is holding the GIL will it return ‘1’. This is mainly a helper/diagnostic function. It can be useful for example in callback contexts or memory allocation functions when knowing that the GIL is locked can allow the caller to perform sensitive actions or otherwise behave differently. New in version 3.4. The following macros are normally used without a trailing semicolon; look for example usage in the Python source distribution. -- C Macro: Py_BEGIN_ALLOW_THREADS This macro expands to ‘{ PyThreadState *_save; _save = PyEval_SaveThread();’. Note that it contains an opening brace; it must be matched with a following *note Py_END_ALLOW_THREADS: 2b5. macro. See above for further discussion of this macro. -- C Macro: Py_END_ALLOW_THREADS This macro expands to ‘PyEval_RestoreThread(_save); }’. Note that it contains a closing brace; it must be matched with an earlier *note Py_BEGIN_ALLOW_THREADS: 3866. macro. See above for further discussion of this macro. -- C Macro: Py_BLOCK_THREADS This macro expands to ‘PyEval_RestoreThread(_save);’: it is equivalent to *note Py_END_ALLOW_THREADS: 2b5. without the closing brace. -- C Macro: Py_UNBLOCK_THREADS This macro expands to ‘_save = PyEval_SaveThread();’: it is equivalent to *note Py_BEGIN_ALLOW_THREADS: 3866. without the opening brace and variable declaration.  File: python.info, Node: Low-level API, Prev: High-level API, Up: Thread State and the Global Interpreter Lock 7.9.5.5 Low-level API ..................... All of the following functions must be called after *note Py_Initialize(): 439. Changed in version 3.7: *note Py_Initialize(): 439. now initializes the *note GIL: bea. -- C Function: PyInterpreterState* PyInterpreterState_New () Create a new interpreter state object. The global interpreter lock need not be held, but may be held if it is necessary to serialize calls to this function. Raises an *note auditing event: fd1. ‘cpython.PyInterpreterState_New’ with no arguments. -- C Function: void PyInterpreterState_Clear (PyInterpreterState *interp) Reset all information in an interpreter state object. The global interpreter lock must be held. Raises an *note auditing event: fd1. ‘cpython.PyInterpreterState_Clear’ with no arguments. -- C Function: void PyInterpreterState_Delete (PyInterpreterState *interp) Destroy an interpreter state object. The global interpreter lock need not be held. The interpreter state must have been reset with a previous call to *note PyInterpreterState_Clear(): 31ee. -- C Function: PyThreadState* PyThreadState_New (PyInterpreterState *interp) Create a new thread state object belonging to the given interpreter object. The global interpreter lock need not be held, but may be held if it is necessary to serialize calls to this function. -- C Function: void PyThreadState_Clear (PyThreadState *tstate) Reset all information in a thread state object. The global interpreter lock must be held. -- C Function: void PyThreadState_Delete (PyThreadState *tstate) Destroy a thread state object. The global interpreter lock need not be held. The thread state must have been reset with a previous call to *note PyThreadState_Clear(): 3d05. -- C Function: PY_INT64_T PyInterpreterState_GetID (PyInterpreterState *interp) Return the interpreter’s unique ID. If there was any error in doing so then ‘-1’ is returned and an error is set. New in version 3.7. -- C Function: PyObject* PyInterpreterState_GetDict (PyInterpreterState *interp) Return a dictionary in which interpreter-specific data may be stored. If this function returns ‘NULL’ then no exception has been raised and the caller should assume no interpreter-specific dict is available. This is not a replacement for *note PyModule_GetState(): 3c2c, which extensions should use to store interpreter-specific state information. New in version 3.8. -- C Function: PyObject* PyThreadState_GetDict () `Return value: Borrowed reference.' Return a dictionary in which extensions can store thread-specific state information. Each extension should use a unique key to use to store state in the dictionary. It is okay to call this function when no current thread state is available. If this function returns ‘NULL’, no exception has been raised and the caller should assume no current thread state is available. -- C Function: int PyThreadState_SetAsyncExc (unsigned long id, PyObject *exc) Asynchronously raise an exception in a thread. The `id' argument is the thread id of the target thread; `exc' is the exception object to be raised. This function does not steal any references to `exc'. To prevent naive misuse, you must write your own C extension to call this. Must be called with the GIL held. Returns the number of thread states modified; this is normally one, but will be zero if the thread id isn’t found. If `exc' is ‘NULL’, the pending exception (if any) for the thread is cleared. This raises no exceptions. Changed in version 3.7: The type of the `id' parameter changed from ‘long’ to ‘unsigned long’. -- C Function: void PyEval_AcquireThread (PyThreadState *tstate) Acquire the global interpreter lock and set the current thread state to `tstate', which should not be ‘NULL’. The lock must have been created earlier. If this thread already has the lock, deadlock ensues. Note: Calling this function from a thread when the runtime is finalizing will terminate the thread, even if the thread was not created by Python. You can use ‘_Py_IsFinalizing()’ or *note sys.is_finalizing(): 762. to check if the interpreter is in process of being finalized before calling this function to avoid unwanted termination. Changed in version 3.8: Updated to be consistent with *note PyEval_RestoreThread(): 2b4, *note Py_END_ALLOW_THREADS(): 2b5, and *note PyGILState_Ensure(): 2b6, and terminate the current thread if called while the interpreter is finalizing. *note PyEval_RestoreThread(): 2b4. is a higher-level function which is always available (even when threads have not been initialized). -- C Function: void PyEval_ReleaseThread (PyThreadState *tstate) Reset the current thread state to ‘NULL’ and release the global interpreter lock. The lock must have been created earlier and must be held by the current thread. The `tstate' argument, which must not be ‘NULL’, is only used to check that it represents the current thread state — if it isn’t, a fatal error is reported. *note PyEval_SaveThread(): c11. is a higher-level function which is always available (even when threads have not been initialized). -- C Function: void PyEval_AcquireLock () Acquire the global interpreter lock. The lock must have been created earlier. If this thread already has the lock, a deadlock ensues. Deprecated since version 3.2: This function does not update the current thread state. Please use *note PyEval_RestoreThread(): 2b4. or *note PyEval_AcquireThread(): 2b3. instead. Note: Calling this function from a thread when the runtime is finalizing will terminate the thread, even if the thread was not created by Python. You can use ‘_Py_IsFinalizing()’ or *note sys.is_finalizing(): 762. to check if the interpreter is in process of being finalized before calling this function to avoid unwanted termination. Changed in version 3.8: Updated to be consistent with *note PyEval_RestoreThread(): 2b4, *note Py_END_ALLOW_THREADS(): 2b5, and *note PyGILState_Ensure(): 2b6, and terminate the current thread if called while the interpreter is finalizing. -- C Function: void PyEval_ReleaseLock () Release the global interpreter lock. The lock must have been created earlier. Deprecated since version 3.2: This function does not update the current thread state. Please use *note PyEval_SaveThread(): c11. or *note PyEval_ReleaseThread(): 3d09. instead.  File: python.info, Node: Sub-interpreter support, Next: Asynchronous Notifications, Prev: Thread State and the Global Interpreter Lock, Up: Initialization Finalization and Threads 7.9.6 Sub-interpreter support ----------------------------- While in most uses, you will only embed a single Python interpreter, there are cases where you need to create several independent interpreters in the same process and perhaps even in the same thread. Sub-interpreters allow you to do that. The “main” interpreter is the first one created when the runtime initializes. It is usually the only Python interpreter in a process. Unlike sub-interpreters, the main interpreter has unique process-global responsibilities like signal handling. It is also responsible for execution during runtime initialization and is usually the active interpreter during runtime finalization. The *note PyInterpreterState_Main(): 3d0b. function returns a pointer to its state. You can switch between sub-interpreters using the *note PyThreadState_Swap(): 3cfd. function. You can create and destroy them using the following functions: -- C Function: PyThreadState* Py_NewInterpreter () Create a new sub-interpreter. This is an (almost) totally separate environment for the execution of Python code. In particular, the new interpreter has separate, independent versions of all imported modules, including the fundamental modules *note builtins: 13, *note __main__: 1. and *note sys: fd. The table of loaded modules (‘sys.modules’) and the module search path (‘sys.path’) are also separate. The new environment has no ‘sys.argv’ variable. It has new standard I/O stream file objects ‘sys.stdin’, ‘sys.stdout’ and ‘sys.stderr’ (however these refer to the same underlying file descriptors). The return value points to the first thread state created in the new sub-interpreter. This thread state is made in the current thread state. Note that no actual thread is created; see the discussion of thread states below. If creation of the new interpreter is unsuccessful, ‘NULL’ is returned; no exception is set since the exception state is stored in the current thread state and there may not be a current thread state. (Like all other Python/C API functions, the global interpreter lock must be held before calling this function and is still held when it returns; however, unlike most other Python/C API functions, there needn’t be a current thread state on entry.) Extension modules are shared between (sub-)interpreters as follows: * For modules using multi-phase initialization, e.g. *note PyModule_FromDefAndSpec(): 7ab, a separate module object is created and initialized for each interpreter. Only C-level static and global variables are shared between these module objects. * For modules using single-phase initialization, e.g. *note PyModule_Create(): 3847, the first time a particular extension is imported, it is initialized normally, and a (shallow) copy of its module’s dictionary is squirreled away. When the same extension is imported by another (sub-)interpreter, a new module is initialized and filled with the contents of this copy; the extension’s ‘init’ function is not called. Objects in the module’s dictionary thus end up shared across (sub-)interpreters, which might cause unwanted behavior (see *note Bugs and caveats: 3d0c. below). Note that this is different from what happens when an extension is imported after the interpreter has been completely re-initialized by calling *note Py_FinalizeEx(): 5c9. and *note Py_Initialize(): 439.; in that case, the extension’s ‘initmodule’ function `is' called again. As with multi-phase initialization, this means that only C-level static and global variables are shared between these modules. -- C Function: void Py_EndInterpreter (PyThreadState *tstate) Destroy the (sub-)interpreter represented by the given thread state. The given thread state must be the current thread state. See the discussion of thread states below. When the call returns, the current thread state is ‘NULL’. All thread states associated with this interpreter are destroyed. (The global interpreter lock must be held before calling this function and is still held when it returns.) *note Py_FinalizeEx(): 5c9. will destroy all sub-interpreters that haven’t been explicitly destroyed at that point. * Menu: * Bugs and caveats::  File: python.info, Node: Bugs and caveats, Up: Sub-interpreter support 7.9.6.1 Bugs and caveats ........................ Because sub-interpreters (and the main interpreter) are part of the same process, the insulation between them isn’t perfect — for example, using low-level file operations like *note os.close(): 3d2. they can (accidentally or maliciously) affect each other’s open files. Because of the way extensions are shared between (sub-)interpreters, some extensions may not work properly; this is especially likely when using single-phase initialization or (static) global variables. It is possible to insert objects created in one sub-interpreter into a namespace of another (sub-)interpreter; this should be avoided if possible. Special care should be taken to avoid sharing user-defined functions, methods, instances or classes between sub-interpreters, since import operations executed by such objects may affect the wrong (sub-)interpreter’s dictionary of loaded modules. It is equally important to avoid sharing objects from which the above are reachable. Also note that combining this functionality with ‘PyGILState_*()’ APIs is delicate, because these APIs assume a bijection between Python thread states and OS-level threads, an assumption broken by the presence of sub-interpreters. It is highly recommended that you don’t switch sub-interpreters between a pair of matching *note PyGILState_Ensure(): 2b6. and *note PyGILState_Release(): 3cfa. calls. Furthermore, extensions (such as *note ctypes: 2b.) using these APIs to allow calling of Python code from non-Python created threads will probably be broken when using sub-interpreters.  File: python.info, Node: Asynchronous Notifications, Next: Profiling and Tracing, Prev: Sub-interpreter support, Up: Initialization Finalization and Threads 7.9.7 Asynchronous Notifications -------------------------------- A mechanism is provided to make asynchronous notifications to the main interpreter thread. These notifications take the form of a function pointer and a void pointer argument. -- C Function: int Py_AddPendingCall (int (*func)(void *), void *arg) Schedule a function to be called from the main interpreter thread. On success, ‘0’ is returned and `func' is queued for being called in the main thread. On failure, ‘-1’ is returned without setting any exception. When successfully queued, `func' will be `eventually' called from the main interpreter thread with the argument `arg'. It will be called asynchronously with respect to normally running Python code, but with both these conditions met: * on a *note bytecode: 614. boundary; * with the main thread holding the *note global interpreter lock: 506. (`func' can therefore use the full C API). `func' must return ‘0’ on success, or ‘-1’ on failure with an exception set. `func' won’t be interrupted to perform another asynchronous notification recursively, but it can still be interrupted to switch threads if the global interpreter lock is released. This function doesn’t need a current thread state to run, and it doesn’t need the global interpreter lock. Warning: This is a low-level function, only useful for very special cases. There is no guarantee that `func' will be called as quick as possible. If the main thread is busy executing a system call, `func' won’t be called before the system call returns. This function is generally `not' suitable for calling Python code from arbitrary C threads. Instead, use the *note PyGILState API: 3cf8. New in version 3.1.  File: python.info, Node: Profiling and Tracing, Next: Advanced Debugger Support, Prev: Asynchronous Notifications, Up: Initialization Finalization and Threads 7.9.8 Profiling and Tracing --------------------------- The Python interpreter provides some low-level support for attaching profiling and execution tracing facilities. These are used for profiling, debugging, and coverage analysis tools. This C interface allows the profiling or tracing code to avoid the overhead of calling through Python-level callable objects, making a direct C function call instead. The essential attributes of the facility have not changed; the interface allows trace functions to be installed per-thread, and the basic events reported to the trace function are the same as had been reported to the Python-level trace functions in previous versions. -- C Type: int (*Py_tracefunc) (PyObject *obj, PyFrameObject *frame, int what, PyObject *arg) The type of the trace function registered using *note PyEval_SetProfile(): e3b. and *note PyEval_SetTrace(): e3c. The first parameter is the object passed to the registration function as `obj', `frame' is the frame object to which the event pertains, `what' is one of the constants ‘PyTrace_CALL’, ‘PyTrace_EXCEPTION’, ‘PyTrace_LINE’, ‘PyTrace_RETURN’, ‘PyTrace_C_CALL’, ‘PyTrace_C_EXCEPTION’, ‘PyTrace_C_RETURN’, or ‘PyTrace_OPCODE’, and `arg' depends on the value of `what': Value of `what' Meaning of `arg' -------------------------------------------------------------------------------- ‘PyTrace_CALL’ Always *note Py_None: 3844. ‘PyTrace_EXCEPTION’ Exception information as returned by *note sys.exc_info(): c5f. ‘PyTrace_LINE’ Always *note Py_None: 3844. ‘PyTrace_RETURN’ Value being returned to the caller, or ‘NULL’ if caused by an exception. ‘PyTrace_C_CALL’ Function object being called. ‘PyTrace_C_EXCEPTION’ Function object being called. ‘PyTrace_C_RETURN’ Function object being called. ‘PyTrace_OPCODE’ Always *note Py_None: 3844. -- C Variable: int PyTrace_CALL The value of the `what' parameter to a *note Py_tracefunc: 3d11. function when a new call to a function or method is being reported, or a new entry into a generator. Note that the creation of the iterator for a generator function is not reported as there is no control transfer to the Python bytecode in the corresponding frame. -- C Variable: int PyTrace_EXCEPTION The value of the `what' parameter to a *note Py_tracefunc: 3d11. function when an exception has been raised. The callback function is called with this value for `what' when after any bytecode is processed after which the exception becomes set within the frame being executed. The effect of this is that as exception propagation causes the Python stack to unwind, the callback is called upon return to each frame as the exception propagates. Only trace functions receives these events; they are not needed by the profiler. -- C Variable: int PyTrace_LINE The value passed as the `what' parameter to a *note Py_tracefunc: 3d11. function (but not a profiling function) when a line-number event is being reported. It may be disabled for a frame by setting ‘f_trace_lines’ to `0' on that frame. -- C Variable: int PyTrace_RETURN The value for the `what' parameter to *note Py_tracefunc: 3d11. functions when a call is about to return. -- C Variable: int PyTrace_C_CALL The value for the `what' parameter to *note Py_tracefunc: 3d11. functions when a C function is about to be called. -- C Variable: int PyTrace_C_EXCEPTION The value for the `what' parameter to *note Py_tracefunc: 3d11. functions when a C function has raised an exception. -- C Variable: int PyTrace_C_RETURN The value for the `what' parameter to *note Py_tracefunc: 3d11. functions when a C function has returned. -- C Variable: int PyTrace_OPCODE The value for the `what' parameter to *note Py_tracefunc: 3d11. functions (but not profiling functions) when a new opcode is about to be executed. This event is not emitted by default: it must be explicitly requested by setting ‘f_trace_opcodes’ to `1' on the frame. -- C Function: void PyEval_SetProfile (Py_tracefunc func, PyObject *obj) Set the profiler function to `func'. The `obj' parameter is passed to the function as its first parameter, and may be any Python object, or ‘NULL’. If the profile function needs to maintain state, using a different value for `obj' for each thread provides a convenient and thread-safe place to store it. The profile function is called for all monitored events except ‘PyTrace_LINE’ ‘PyTrace_OPCODE’ and ‘PyTrace_EXCEPTION’. -- C Function: void PyEval_SetTrace (Py_tracefunc func, PyObject *obj) Set the tracing function to `func'. This is similar to *note PyEval_SetProfile(): e3b, except the tracing function does receive line-number events and per-opcode events, but does not receive any event related to C function objects being called. Any trace function registered using *note PyEval_SetTrace(): e3c. will not receive ‘PyTrace_C_CALL’, ‘PyTrace_C_EXCEPTION’ or ‘PyTrace_C_RETURN’ as a value for the `what' parameter.  File: python.info, Node: Advanced Debugger Support, Next: Thread Local Storage Support, Prev: Profiling and Tracing, Up: Initialization Finalization and Threads 7.9.9 Advanced Debugger Support ------------------------------- These functions are only intended to be used by advanced debugging tools. -- C Function: PyInterpreterState* PyInterpreterState_Head () Return the interpreter state object at the head of the list of all such objects. -- C Function: PyInterpreterState* PyInterpreterState_Main () Return the main interpreter state object. -- C Function: PyInterpreterState* PyInterpreterState_Next (PyInterpreterState *interp) Return the next interpreter state object after `interp' from the list of all such objects. -- C Function: PyThreadState * PyInterpreterState_ThreadHead (PyInterpreterState *interp) Return the pointer to the first *note PyThreadState: 3cf5. object in the list of threads associated with the interpreter `interp'. -- C Function: PyThreadState* PyThreadState_Next (PyThreadState *tstate) Return the next thread state object after `tstate' from the list of all such objects belonging to the same *note PyInterpreterState: 2c2. object.  File: python.info, Node: Thread Local Storage Support, Prev: Advanced Debugger Support, Up: Initialization Finalization and Threads 7.9.10 Thread Local Storage Support ----------------------------------- The Python interpreter provides low-level support for thread-local storage (TLS) which wraps the underlying native TLS implementation to support the Python-level thread local storage API (*note threading.local: 1fdc.). The CPython C level APIs are similar to those offered by pthreads and Windows: use a thread key and functions to associate a ‘void*’ value per thread. The GIL does `not' need to be held when calling these functions; they supply their own locking. Note that ‘Python.h’ does not include the declaration of the TLS APIs, you need to include ‘pythread.h’ to use thread-local storage. Note: None of these API functions handle memory management on behalf of the ‘void*’ values. You need to allocate and deallocate them yourself. If the ‘void*’ values happen to be *note PyObject*: 4ba, these functions don’t do refcount operations on them either. * Menu: * Thread Specific Storage (TSS) API: Thread Specific Storage TSS API. * Thread Local Storage (TLS) API: Thread Local Storage TLS API.  File: python.info, Node: Thread Specific Storage TSS API, Next: Thread Local Storage TLS API, Up: Thread Local Storage Support 7.9.10.1 Thread Specific Storage (TSS) API .......................................... TSS API is introduced to supersede the use of the existing TLS API within the CPython interpreter. This API uses a new type *note Py_tss_t: 318. instead of ‘int’ to represent thread keys. New in version 3.7. See also ........ “A New C-API for Thread-Local Storage in CPython” ( PEP 539(1)) -- C Type: Py_tss_t This data structure represents the state of a thread key, the definition of which may depend on the underlying TLS implementation, and it has an internal field representing the key’s initialization state. There are no public members in this structure. When *note Py_LIMITED_API: 3905. is not defined, static allocation of this type by *note Py_tss_NEEDS_INIT: 3d1f. is allowed. -- C Macro: Py_tss_NEEDS_INIT This macro expands to the initializer for *note Py_tss_t: 318. variables. Note that this macro won’t be defined with *note Py_LIMITED_API: 3905. * Menu: * Dynamic Allocation:: * Methods: Methods<4>. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0539  File: python.info, Node: Dynamic Allocation, Next: Methods<4>, Up: Thread Specific Storage TSS API 7.9.10.2 Dynamic Allocation ........................... Dynamic allocation of the *note Py_tss_t: 318, required in extension modules built with *note Py_LIMITED_API: 3905, where static allocation of this type is not possible due to its implementation being opaque at build time. -- C Function: Py_tss_t* PyThread_tss_alloc () Return a value which is the same state as a value initialized with *note Py_tss_NEEDS_INIT: 3d1f, or ‘NULL’ in the case of dynamic allocation failure. -- C Function: void PyThread_tss_free (Py_tss_t *key) Free the given `key' allocated by *note PyThread_tss_alloc(): 3d21, after first calling *note PyThread_tss_delete(): 3d23. to ensure any associated thread locals have been unassigned. This is a no-op if the `key' argument is ‘NULL’. Note: A freed key becomes a dangling pointer, you should reset the key to ‘NULL’.  File: python.info, Node: Methods<4>, Prev: Dynamic Allocation, Up: Thread Specific Storage TSS API 7.9.10.3 Methods ................ The parameter `key' of these functions must not be ‘NULL’. Moreover, the behaviors of *note PyThread_tss_set(): 3d25. and *note PyThread_tss_get(): 3d26. are undefined if the given *note Py_tss_t: 318. has not been initialized by *note PyThread_tss_create(): 3d27. -- C Function: int PyThread_tss_is_created (Py_tss_t *key) Return a non-zero value if the given *note Py_tss_t: 318. has been initialized by *note PyThread_tss_create(): 3d27. -- C Function: int PyThread_tss_create (Py_tss_t *key) Return a zero value on successful initialization of a TSS key. The behavior is undefined if the value pointed to by the `key' argument is not initialized by *note Py_tss_NEEDS_INIT: 3d1f. This function can be called repeatedly on the same key – calling it on an already initialized key is a no-op and immediately returns success. -- C Function: void PyThread_tss_delete (Py_tss_t *key) Destroy a TSS key to forget the values associated with the key across all threads, and change the key’s initialization state to uninitialized. A destroyed key is able to be initialized again by *note PyThread_tss_create(): 3d27. This function can be called repeatedly on the same key – calling it on an already destroyed key is a no-op. -- C Function: int PyThread_tss_set (Py_tss_t *key, void *value) Return a zero value to indicate successfully associating a ‘void*’ value with a TSS key in the current thread. Each thread has a distinct mapping of the key to a ‘void*’ value. -- C Function: void* PyThread_tss_get (Py_tss_t *key) Return the ‘void*’ value associated with a TSS key in the current thread. This returns ‘NULL’ if no value is associated with the key in the current thread.  File: python.info, Node: Thread Local Storage TLS API, Prev: Thread Specific Storage TSS API, Up: Thread Local Storage Support 7.9.10.4 Thread Local Storage (TLS) API ....................................... Deprecated since version 3.7: This API is superseded by *note Thread Specific Storage (TSS) API: 317. Note: This version of the API does not support platforms where the native TLS key is defined in a way that cannot be safely cast to ‘int’. On such platforms, *note PyThread_create_key(): 3d2a. will return immediately with a failure status, and the other TLS functions will all be no-ops on such platforms. Due to the compatibility problem noted above, this version of the API should not be used in new code. -- C Function: int PyThread_create_key () -- C Function: void PyThread_delete_key (int key) -- C Function: int PyThread_set_key_value (int key, void *value) -- C Function: void* PyThread_get_key_value (int key) -- C Function: void PyThread_delete_key_value (int key) -- C Function: void PyThread_ReInitTLS ()  File: python.info, Node: Python Initialization Configuration, Next: Memory Management, Prev: Initialization Finalization and Threads, Up: Python/C API Reference Manual 7.10 Python Initialization Configuration ======================================== New in version 3.8. Structures: * *note PyConfig: 15f. * *note PyPreConfig: 160. * *note PyStatus: 161. * *note PyWideStringList: 162. Functions: * *note PyConfig_Clear(): 163. * *note PyConfig_InitIsolatedConfig(): 164. * *note PyConfig_InitPythonConfig(): 165. * *note PyConfig_Read(): 166. * *note PyConfig_SetArgv(): 167. * *note PyConfig_SetBytesArgv(): 168. * *note PyConfig_SetBytesString(): 169. * *note PyConfig_SetString(): 16a. * *note PyConfig_SetWideStringList(): 3d31. * *note PyPreConfig_InitIsolatedConfig(): 16b. * *note PyPreConfig_InitPythonConfig(): 16c. * *note PyStatus_Error(): 16d. * *note PyStatus_Exception(): 16e. * *note PyStatus_Exit(): 16f. * *note PyStatus_IsError(): 170. * *note PyStatus_IsExit(): 171. * *note PyStatus_NoMemory(): 172. * *note PyStatus_Ok(): 173. * *note PyWideStringList_Append(): 174. * *note PyWideStringList_Insert(): 175. * *note Py_ExitStatusException(): 177. * *note Py_InitializeFromConfig(): 178. * *note Py_PreInitialize(): 179. * *note Py_PreInitializeFromArgs(): 17a. * *note Py_PreInitializeFromBytesArgs(): 17b. * *note Py_RunMain(): 17c. The preconfiguration (‘PyPreConfig’ type) is stored in ‘_PyRuntime.preconfig’ and the configuration (‘PyConfig’ type) is stored in ‘PyInterpreterState.config’. See also *note Initialization, Finalization, and Threads: 3cd4. See also ........ PEP 587(1) “Python Initialization Configuration”. * Menu: * PyWideStringList:: * PyStatus:: * PyPreConfig:: * Preinitialization with PyPreConfig:: * PyConfig:: * Initialization with PyConfig:: * Isolated Configuration:: * Python Configuration:: * Path Configuration:: * Py_RunMain(): Py_RunMain. * Multi-Phase Initialization Private Provisional API:: ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0587  File: python.info, Node: PyWideStringList, Next: PyStatus, Up: Python Initialization Configuration 7.10.1 PyWideStringList ----------------------- -- C Type: PyWideStringList List of ‘wchar_t*’ strings. If `length' is non-zero, `items' must be non-‘NULL’ and all strings must be non-‘NULL’. Methods: -- C Function: PyStatus PyWideStringList_Append (PyWideStringList *list, const wchar_t *item) Append `item' to `list'. Python must be preinitialized to call this function. -- C Function: PyStatus PyWideStringList_Insert (PyWideStringList *list, Py_ssize_t index, const wchar_t *item) Insert `item' into `list' at `index'. If `index' is greater than or equal to `list' length, append `item' to `list'. `index' must be greater than or equal to 0. Python must be preinitialized to call this function. Structure fields: -- C Member: Py_ssize_t length List length. -- C Member: wchar_t** items List items.  File: python.info, Node: PyStatus, Next: PyPreConfig, Prev: PyWideStringList, Up: Python Initialization Configuration 7.10.2 PyStatus --------------- -- C Type: PyStatus Structure to store an initialization function status: success, error or exit. For an error, it can store the C function name which created the error. Structure fields: -- C Member: int exitcode Exit code. Argument passed to ‘exit()’. -- C Member: const char *err_msg Error message. -- C Member: const char *func Name of the function which created an error, can be ‘NULL’. Functions to create a status: -- C Function: PyStatus PyStatus_Ok (void) Success. -- C Function: PyStatus PyStatus_Error (const char *err_msg) Initialization error with a message. -- C Function: PyStatus PyStatus_NoMemory (void) Memory allocation failure (out of memory). -- C Function: PyStatus PyStatus_Exit (int exitcode) Exit Python with the specified exit code. Functions to handle a status: -- C Function: int PyStatus_Exception (PyStatus status) Is the status an error or an exit? If true, the exception must be handled; by calling *note Py_ExitStatusException(): 177. for example. -- C Function: int PyStatus_IsError (PyStatus status) Is the result an error? -- C Function: int PyStatus_IsExit (PyStatus status) Is the result an exit? -- C Function: void Py_ExitStatusException (PyStatus status) Call ‘exit(exitcode)’ if `status' is an exit. Print the error message and exit with a non-zero exit code if `status' is an error. Must only be called if ‘PyStatus_Exception(status)’ is non-zero. Note: Internally, Python uses macros which set ‘PyStatus.func’, whereas functions to create a status set ‘func’ to ‘NULL’. Example: PyStatus alloc(void **ptr, size_t size) { *ptr = PyMem_RawMalloc(size); if (*ptr == NULL) { return PyStatus_NoMemory(); } return PyStatus_Ok(); } int main(int argc, char **argv) { void *ptr; PyStatus status = alloc(&ptr, 16); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } PyMem_Free(ptr); return 0; }  File: python.info, Node: PyPreConfig, Next: Preinitialization with PyPreConfig, Prev: PyStatus, Up: Python Initialization Configuration 7.10.3 PyPreConfig ------------------ -- C Type: PyPreConfig Structure used to preinitialize Python: * Set the Python memory allocator * Configure the LC_CTYPE locale * Set the UTF-8 mode Function to initialize a preconfiguration: -- C Function: void PyPreConfig_InitPythonConfig (PyPreConfig *preconfig) Initialize the preconfiguration with *note Python Configuration: 3d3a. -- C Function: void PyPreConfig_InitIsolatedConfig (PyPreConfig *preconfig) Initialize the preconfiguration with *note Isolated Configuration: 3d3b. Structure fields: -- C Member: int allocator Name of the memory allocator: * ‘PYMEM_ALLOCATOR_NOT_SET’ (‘0’): don’t change memory allocators (use defaults) * ‘PYMEM_ALLOCATOR_DEFAULT’ (‘1’): default memory allocators * ‘PYMEM_ALLOCATOR_DEBUG’ (‘2’): default memory allocators with debug hooks * ‘PYMEM_ALLOCATOR_MALLOC’ (‘3’): force usage of ‘malloc()’ * ‘PYMEM_ALLOCATOR_MALLOC_DEBUG’ (‘4’): force usage of ‘malloc()’ with debug hooks * ‘PYMEM_ALLOCATOR_PYMALLOC’ (‘5’): *note Python pymalloc memory allocator: 5c1. * ‘PYMEM_ALLOCATOR_PYMALLOC_DEBUG’ (‘6’): *note Python pymalloc memory allocator: 5c1. with debug hooks ‘PYMEM_ALLOCATOR_PYMALLOC’ and ‘PYMEM_ALLOCATOR_PYMALLOC_DEBUG’ are not supported if Python is configured using ‘--without-pymalloc’ See *note Memory Management: 3d3d. -- C Member: int configure_locale Set the LC_CTYPE locale to the user preferred locale? If equals to 0, set ‘coerce_c_locale’ and ‘coerce_c_locale_warn’ to 0. -- C Member: int coerce_c_locale If equals to 2, coerce the C locale; if equals to 1, read the LC_CTYPE locale to decide if it should be coerced. -- C Member: int coerce_c_locale_warn If non-zero, emit a warning if the C locale is coerced. -- C Member: int dev_mode See *note PyConfig.dev_mode: 3d42. -- C Member: int isolated See *note PyConfig.isolated: 3d44. -- C Member: int legacy_windows_fs_encoding (Windows only) If non-zero, disable UTF-8 Mode, set the Python filesystem encoding to ‘mbcs’, set the filesystem error handler to ‘replace’. Only available on Windows. ‘#ifdef MS_WINDOWS’ macro can be used for Windows specific code. -- C Member: int parse_argv If non-zero, *note Py_PreInitializeFromArgs(): 17a. and *note Py_PreInitializeFromBytesArgs(): 17b. parse their ‘argv’ argument the same way the regular Python parses command line arguments: see *note Command Line Arguments: 92b. -- C Member: int use_environment See *note PyConfig.use_environment: 3d48. -- C Member: int utf8_mode If non-zero, enable the UTF-8 mode.  File: python.info, Node: Preinitialization with PyPreConfig, Next: PyConfig, Prev: PyPreConfig, Up: Python Initialization Configuration 7.10.4 Preinitialization with PyPreConfig ----------------------------------------- Functions to preinitialize Python: -- C Function: PyStatus Py_PreInitialize (const PyPreConfig *preconfig) Preinitialize Python from `preconfig' preconfiguration. -- C Function: PyStatus Py_PreInitializeFromBytesArgs (const PyPreConfig *preconfig, int argc, char * const *argv) Preinitialize Python from `preconfig' preconfiguration and command line arguments (bytes strings). -- C Function: PyStatus Py_PreInitializeFromArgs (const PyPreConfig *preconfig, int argc, wchar_t * const * argv) Preinitialize Python from `preconfig' preconfiguration and command line arguments (wide strings). The caller is responsible to handle exceptions (error or exit) using *note PyStatus_Exception(): 16e. and *note Py_ExitStatusException(): 177. For *note Python Configuration: 3d3a. (*note PyPreConfig_InitPythonConfig(): 16c.), if Python is initialized with command line arguments, the command line arguments must also be passed to preinitialize Python, since they have an effect on the pre-configuration like encodings. For example, the *note -X utf8: 155. command line option enables the UTF-8 Mode. ‘PyMem_SetAllocator()’ can be called after *note Py_PreInitialize(): 179. and before *note Py_InitializeFromConfig(): 178. to install a custom memory allocator. It can be called before *note Py_PreInitialize(): 179. if *note PyPreConfig.allocator: 3d3c. is set to ‘PYMEM_ALLOCATOR_NOT_SET’. Python memory allocation functions like *note PyMem_RawMalloc(): 96d. must not be used before Python preinitialization, whereas calling directly ‘malloc()’ and ‘free()’ is always safe. *note Py_DecodeLocale(): 43c. must not be called before the preinitialization. Example using the preinitialization to enable the UTF-8 Mode: PyStatus status; PyPreConfig preconfig; PyPreConfig_InitPythonConfig(&preconfig); preconfig.utf8_mode = 1; status = Py_PreInitialize(&preconfig); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } /* at this point, Python will speak UTF-8 */ Py_Initialize(); /* ... use Python API here ... */ Py_Finalize();  File: python.info, Node: PyConfig, Next: Initialization with PyConfig, Prev: Preinitialization with PyPreConfig, Up: Python Initialization Configuration 7.10.5 PyConfig --------------- -- C Type: PyConfig Structure containing most parameters to configure Python. Structure methods: -- C Function: void PyConfig_InitPythonConfig (PyConfig *config) Initialize configuration with *note Python Configuration: 3d3a. -- C Function: void PyConfig_InitIsolatedConfig (PyConfig *config) Initialize configuration with *note Isolated Configuration: 3d3b. -- C Function: PyStatus PyConfig_SetString (PyConfig *config, wchar_t * const *config_str, const wchar_t *str) Copy the wide character string `str' into ‘*config_str’. Preinitialize Python if needed. -- C Function: PyStatus PyConfig_SetBytesString (PyConfig *config, wchar_t * const *config_str, const char *str) Decode `str' using ‘Py_DecodeLocale()’ and set the result into ‘*config_str’. Preinitialize Python if needed. -- C Function: PyStatus PyConfig_SetArgv (PyConfig *config, int argc, wchar_t * const *argv) Set command line arguments from wide character strings. Preinitialize Python if needed. -- C Function: PyStatus PyConfig_SetBytesArgv (PyConfig *config, int argc, char * const *argv) Set command line arguments: decode bytes using *note Py_DecodeLocale(): 43c. Preinitialize Python if needed. -- C Function: PyStatus PyConfig_SetWideStringList (PyConfig *config, PyWideStringList *list, Py_ssize_t length, wchar_t **items) Set the list of wide strings `list' to `length' and `items'. Preinitialize Python if needed. -- C Function: PyStatus PyConfig_Read (PyConfig *config) Read all Python configuration. Fields which are already initialized are left unchanged. Preinitialize Python if needed. -- C Function: void PyConfig_Clear (PyConfig *config) Release configuration memory. Most ‘PyConfig’ methods preinitialize Python if needed. In that case, the Python preinitialization configuration in based on the *note PyConfig: 15f. If configuration fields which are in common with *note PyPreConfig: 160. are tuned, they must be set before calling a *note PyConfig: 15f. method: * *note dev_mode: 3d42. * *note isolated: 3d44. * *note parse_argv: 3d4c. * *note use_environment: 3d48. Moreover, if *note PyConfig_SetArgv(): 167. or *note PyConfig_SetBytesArgv(): 168. is used, this method must be called first, before other methods, since the preinitialization configuration depends on command line arguments (if ‘parse_argv’ is non-zero). The caller of these methods is responsible to handle exceptions (error or exit) using ‘PyStatus_Exception()’ and ‘Py_ExitStatusException()’. Structure fields: -- C Member: PyWideStringList argv Command line arguments, *note sys.argv: bfb. See *note parse_argv: 3d4c. to parse *note argv: 3d4d. the same way the regular Python parses Python command line arguments. If *note argv: 3d4d. is empty, an empty string is added to ensure that *note sys.argv: bfb. always exists and is never empty. -- C Member: wchar_t* base_exec_prefix *note sys.base_exec_prefix: 3324. -- C Member: wchar_t* base_executable ‘sys._base_executable’: ‘__PYVENV_LAUNCHER__’ environment variable value, or copy of *note PyConfig.executable: 3d50. -- C Member: wchar_t* base_prefix *note sys.base_prefix: 2d50. -- C Member: int buffered_stdio If equals to 0, enable unbuffered mode, making the stdout and stderr streams unbuffered. stdin is always opened in buffered mode. -- C Member: int bytes_warning If equals to 1, issue a warning when comparing *note bytes: 331. or *note bytearray: 332. with *note str: 330, or comparing *note bytes: 331. with *note int: 184. If equal or greater to 2, raise a *note BytesWarning: 4b5. exception. -- C Member: wchar_t* check_hash_pycs_mode Control the validation behavior of hash-based ‘.pyc’ files (see PEP 552(1)): *note –check-hash-based-pycs: fd9. command line option value. Valid values: ‘always’, ‘never’ and ‘default’. The default value is: ‘default’. -- C Member: int configure_c_stdio If non-zero, configure C standard streams (‘stdio’, ‘stdout’, ‘stdout’). For example, set their mode to ‘O_BINARY’ on Windows. -- C Member: int dev_mode Development mode: see *note -X dev: 155. -- C Member: int dump_refs If non-zero, dump all objects which are still alive at exit. Require a debug build of Python (‘Py_REF_DEBUG’ macro must be defined). -- C Member: wchar_t* exec_prefix *note sys.exec_prefix: 3323. -- C Member: wchar_t* executable *note sys.executable: 274. -- C Member: int faulthandler If non-zero, call *note faulthandler.enable(): 548. at startup. -- C Member: wchar_t* filesystem_encoding Filesystem encoding, *note sys.getfilesystemencoding(): 4f6. -- C Member: wchar_t* filesystem_errors Filesystem encoding errors, *note sys.getfilesystemencodeerrors(): 594. -- C Member: unsigned long hash_seed -- C Member: int use_hash_seed Randomized hash function seed. If *note use_hash_seed: 3d5c. is zero, a seed is chosen randomly at Pythonstartup, and *note hash_seed: 3d5b. is ignored. -- C Member: wchar_t* home Python home directory. Initialized from *note PYTHONHOME: 4d6. environment variable value by default. -- C Member: int import_time If non-zero, profile import time. -- C Member: int inspect Enter interactive mode after executing a script or a command. -- C Member: int install_signal_handlers Install signal handlers? -- C Member: int interactive Interactive mode. -- C Member: int isolated If greater than 0, enable isolated mode: * *note sys.path: 488. contains neither the script’s directory (computed from ‘argv[0]’ or the current directory) nor the user’s site-packages directory. * Python REPL doesn’t import *note readline: de. nor enable default readline configuration on interactive prompts. * Set *note use_environment: 3d48. and *note user_site_directory: 3d62. to 0. -- C Member: int legacy_windows_stdio If non-zero, use *note io.FileIO: ca4. instead of ‘io.WindowsConsoleIO’ for *note sys.stdin: 30d, *note sys.stdout: 30e. and *note sys.stderr: 30f. Only available on Windows. ‘#ifdef MS_WINDOWS’ macro can be used for Windows specific code. -- C Member: int malloc_stats If non-zero, dump statistics on *note Python pymalloc memory allocator: 5c1. at exit. The option is ignored if Python is built using ‘--without-pymalloc’. -- C Member: wchar_t* pythonpath_env Module search paths as a string separated by ‘DELIM’ (‘os.path.pathsep’). Initialized from *note PYTHONPATH: 953. environment variable value by default. -- C Member: PyWideStringList module_search_paths -- C Member: int module_search_paths_set *note sys.path: 488. If *note module_search_paths_set: 3d67. is equal to 0, the *note module_search_paths: 3d66. is overridden by the function calculating the *note Path Configuration: 3d68. -- C Member: int optimization_level Compilation optimization level: * 0: Peephole optimizer (and ‘__debug__’ is set to ‘True’) * 1: Remove assertions, set ‘__debug__’ to ‘False’ * 2: Strip docstrings -- C Member: int parse_argv If non-zero, parse *note argv: 3d4d. the same way the regular Python command line arguments, and strip Python arguments from *note argv: 3d4d.: see *note Command Line Arguments: 92b. -- C Member: int parser_debug If non-zero, turn on parser debugging output (for expert only, depending on compilation options). -- C Member: int pathconfig_warnings If equal to 0, suppress warnings when calculating the *note Path Configuration: 3d68. (Unix only, Windows does not log any warning). Otherwise, warnings are written into ‘stderr’. -- C Member: wchar_t* prefix *note sys.prefix: 3322. -- C Member: wchar_t* program_name Program name. Used to initialize *note executable: 3d50, and in early error messages. -- C Member: wchar_t* pycache_prefix *note sys.pycache_prefix: 156.: ‘.pyc’ cache prefix. If ‘NULL’, *note sys.pycache_prefix: 156. is set to ‘None’. -- C Member: int quiet Quiet mode. For example, don’t display the copyright and version messages in interactive mode. -- C Member: wchar_t* run_command ‘python3 -c COMMAND’ argument. Used by *note Py_RunMain(): 17c. -- C Member: wchar_t* run_filename ‘python3 FILENAME’ argument. Used by *note Py_RunMain(): 17c. -- C Member: wchar_t* run_module ‘python3 -m MODULE’ argument. Used by *note Py_RunMain(): 17c. -- C Member: int show_alloc_count Show allocation counts at exit? Set to 1 by *note -X showalloccount: 155. command line option. Need a special Python build with ‘COUNT_ALLOCS’ macro defined. -- C Member: int show_ref_count Show total reference count at exit? Set to 1 by *note -X showrefcount: 155. command line option. Need a debug build of Python (‘Py_REF_DEBUG’ macro must be defined). -- C Member: int site_import Import the *note site: eb. module at startup? -- C Member: int skip_source_first_line Skip the first line of the source? -- C Member: wchar_t* stdio_encoding -- C Member: wchar_t* stdio_errors Encoding and encoding errors of *note sys.stdin: 30d, *note sys.stdout: 30e. and *note sys.stderr: 30f. -- C Member: int tracemalloc If non-zero, call *note tracemalloc.start(): fea. at startup. -- C Member: int use_environment If greater than 0, use *note environment variables: fef. -- C Member: int user_site_directory If non-zero, add user site directory to *note sys.path: 488. -- C Member: int verbose If non-zero, enable verbose mode. -- C Member: PyWideStringList warnoptions *note sys.warnoptions: 416.: options of the *note warnings: 126. module to build warnings filters: lowest to highest priority. The *note warnings: 126. module adds *note sys.warnoptions: 416. in the reverse order: the last *note PyConfig.warnoptions: 3d7b. item becomes the first item of ‘warnings.filters’ which is checked first (highest priority). -- C Member: int write_bytecode If non-zero, write ‘.pyc’ files. *note sys.dont_write_bytecode: 3351. is initialized to the inverted value of *note write_bytecode: 3d7c. -- C Member: PyWideStringList xoptions *note sys._xoptions: fec. If ‘parse_argv’ is non-zero, ‘argv’ arguments are parsed the same way the regular Python parses command line arguments, and Python arguments are stripped from ‘argv’: see *note Command Line Arguments: 92b. The ‘xoptions’ options are parsed to set other options: see *note -X: 155. option. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0552  File: python.info, Node: Initialization with PyConfig, Next: Isolated Configuration, Prev: PyConfig, Up: Python Initialization Configuration 7.10.6 Initialization with PyConfig ----------------------------------- Function to initialize Python: -- C Function: PyStatus Py_InitializeFromConfig (const PyConfig *config) Initialize Python from `config' configuration. The caller is responsible to handle exceptions (error or exit) using *note PyStatus_Exception(): 16e. and *note Py_ExitStatusException(): 177. If ‘PyImport_FrozenModules’, ‘PyImport_AppendInittab()’ or ‘PyImport_ExtendInittab()’ are used, they must be set or called after Python preinitialization and before the Python initialization. Example setting the program name: void init_python(void) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); /* Set the program name. Implicitly preinitialize Python. */ status = PyConfig_SetString(&config, &config.program_name, L"/path/to/my_program"); if (PyStatus_Exception(status)) { goto fail; } status = Py_InitializeFromConfig(&config); if (PyStatus_Exception(status)) { goto fail; } PyConfig_Clear(&config); return; fail: PyConfig_Clear(&config); Py_ExitStatusException(status); } More complete example modifying the default configuration, read the configuration, and then override some parameters: PyStatus init_python(const char *program_name) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); /* Set the program name before reading the configuration (decode byte string from the locale encoding). Implicitly preinitialize Python. */ status = PyConfig_SetBytesString(&config, &config.program_name, program_name); if (PyStatus_Exception(status)) { goto done; } /* Read all configuration at once */ status = PyConfig_Read(&config); if (PyStatus_Exception(status)) { goto done; } /* Append our custom search path to sys.path */ status = PyWideStringList_Append(&config.module_search_paths, L"/path/to/more/modules"); if (PyStatus_Exception(status)) { goto done; } /* Override executable computed by PyConfig_Read() */ status = PyConfig_SetString(&config, &config.executable, L"/path/to/my_executable"); if (PyStatus_Exception(status)) { goto done; } status = Py_InitializeFromConfig(&config); done: PyConfig_Clear(&config); return status; }  File: python.info, Node: Isolated Configuration, Next: Python Configuration, Prev: Initialization with PyConfig, Up: Python Initialization Configuration 7.10.7 Isolated Configuration ----------------------------- *note PyPreConfig_InitIsolatedConfig(): 16b. and *note PyConfig_InitIsolatedConfig(): 164. functions create a configuration to isolate Python from the system. For example, to embed Python into an application. This configuration ignores global configuration variables, environments variables, command line arguments (*note PyConfig.argv: 3d4d. is not parsed) and user site directory. The C standard streams (ex: ‘stdout’) and the LC_CTYPE locale are left unchanged. Signal handlers are not installed. Configuration files are still used with this configuration. Set the *note Path Configuration: 3d68. (“output fields”) to ignore these configuration files and avoid the function computing the default path configuration.  File: python.info, Node: Python Configuration, Next: Path Configuration, Prev: Isolated Configuration, Up: Python Initialization Configuration 7.10.8 Python Configuration --------------------------- *note PyPreConfig_InitPythonConfig(): 16c. and *note PyConfig_InitPythonConfig(): 165. functions create a configuration to build a customized Python which behaves as the regular Python. Environments variables and command line arguments are used to configure Python, whereas global configuration variables are ignored. This function enables C locale coercion ( PEP 538(1)) and UTF-8 Mode ( PEP 540(2)) depending on the LC_CTYPE locale, *note PYTHONUTF8: 311. and *note PYTHONCOERCECLOCALE: 30c. environment variables. Example of customized Python always running in isolated mode: int main(int argc, char **argv) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); config.isolated = 1; /* Decode command line arguments. Implicitly preinitialize Python (in isolated mode). */ status = PyConfig_SetBytesArgv(&config, argc, argv); if (PyStatus_Exception(status)) { goto fail; } status = Py_InitializeFromConfig(&config); if (PyStatus_Exception(status)) { goto fail; } PyConfig_Clear(&config); return Py_RunMain(); fail: PyConfig_Clear(&config); if (PyStatus_IsExit(status)) { return status.exitcode; } /* Display the error message and exit the process with non-zero exit code */ Py_ExitStatusException(status); } ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0538 (2) https://www.python.org/dev/peps/pep-0540  File: python.info, Node: Path Configuration, Next: Py_RunMain, Prev: Python Configuration, Up: Python Initialization Configuration 7.10.9 Path Configuration ------------------------- *note PyConfig: 15f. contains multiple fields for the path configuration: * Path configuration inputs: * *note PyConfig.home: 3d5d. * *note PyConfig.pathconfig_warnings: 3d6b. * *note PyConfig.program_name: 3d6d. * *note PyConfig.pythonpath_env: 3d65. * current working directory: to get absolute paths * ‘PATH’ environment variable to get the program full path (from *note PyConfig.program_name: 3d6d.) * ‘__PYVENV_LAUNCHER__’ environment variable * (Windows only) Application paths in the registry under “SoftwarePythonPythonCoreX.YPythonPath” of HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE (where X.Y is the Python version). * Path configuration output fields: * *note PyConfig.base_exec_prefix: 3d4e. * *note PyConfig.base_executable: 3d4f. * *note PyConfig.base_prefix: 3d51. * *note PyConfig.exec_prefix: 3d57. * *note PyConfig.executable: 3d50. * *note PyConfig.module_search_paths_set: 3d67, *note PyConfig.module_search_paths: 3d66. * *note PyConfig.prefix: 3d6c. If at least one “output field” is not set, Python calculates the path configuration to fill unset fields. If *note module_search_paths_set: 3d67. is equal to 0, *note module_search_paths: 3d66. is overridden and *note module_search_paths_set: 3d67. is set to 1. It is possible to completely ignore the function calculating the default path configuration by setting explicitly all path configuration output fields listed above. A string is considered as set even if it is non-empty. ‘module_search_paths’ is considered as set if ‘module_search_paths_set’ is set to 1. In this case, path configuration input fields are ignored as well. Set *note pathconfig_warnings: 3d6b. to 0 to suppress warnings when calculating the path configuration (Unix only, Windows does not log any warning). If *note base_prefix: 3d51. or *note base_exec_prefix: 3d4e. fields are not set, they inherit their value from *note prefix: 3d6c. and *note exec_prefix: 3d57. respectively. *note Py_RunMain(): 17c. and *note Py_Main(): 4b7. modify *note sys.path: 488.: * If *note run_filename: 3d71. is set and is a directory which contains a ‘__main__.py’ script, prepend *note run_filename: 3d71. to *note sys.path: 488. * If *note isolated: 3d44. is zero: * If *note run_module: 3d72. is set, prepend the current directory to *note sys.path: 488. Do nothing if the current directory cannot be read. * If *note run_filename: 3d71. is set, prepend the directory of the filename to *note sys.path: 488. * Otherwise, prepend an empty string to *note sys.path: 488. If *note site_import: 3d75. is non-zero, *note sys.path: 488. can be modified by the *note site: eb. module. If *note user_site_directory: 3d62. is non-zero and the user’s site-package directory exists, the *note site: eb. module appends the user’s site-package directory to *note sys.path: 488. The following configuration files are used by the path configuration: * ‘pyvenv.cfg’ * ‘python._pth’ (Windows only) * ‘pybuilddir.txt’ (Unix only) The ‘__PYVENV_LAUNCHER__’ environment variable is used to set *note PyConfig.base_executable: 3d4f.  File: python.info, Node: Py_RunMain, Next: Multi-Phase Initialization Private Provisional API, Prev: Path Configuration, Up: Python Initialization Configuration 7.10.10 Py_RunMain() -------------------- -- C Function: int Py_RunMain (void) Execute the command (*note PyConfig.run_command: 3d70.), the script (*note PyConfig.run_filename: 3d71.) or the module (*note PyConfig.run_module: 3d72.) specified on the command line or in the configuration. By default and when if *note -i: e1f. option is used, run the REPL. Finally, finalizes Python and returns an exit status that can be passed to the ‘exit()’ function. See *note Python Configuration: 3d3a. for an example of customized Python always running in isolated mode using *note Py_RunMain(): 17c.  File: python.info, Node: Multi-Phase Initialization Private Provisional API, Prev: Py_RunMain, Up: Python Initialization Configuration 7.10.11 Multi-Phase Initialization Private Provisional API ---------------------------------------------------------- This section is a private provisional API introducing multi-phase initialization, the core feature of the PEP 432(1): * “Core” initialization phase, “bare minimum Python”: * Builtin types; * Builtin exceptions; * Builtin and frozen modules; * The *note sys: fd. module is only partially initialized (ex: *note sys.path: 488. doesn’t exist yet). * “Main” initialization phase, Python is fully initialized: * Install and configure *note importlib: 9b.; * Apply the *note Path Configuration: 3d68.; * Install signal handlers; * Finish *note sys: fd. module initialization (ex: create *note sys.stdout: 30e. and *note sys.path: 488.); * Enable optional features like *note faulthandler: 7d. and *note tracemalloc: 114.; * Import the *note site: eb. module; * etc. Private provisional API: * ‘PyConfig._init_main’: if set to 0, *note Py_InitializeFromConfig(): 178. stops at the “Core” initialization phase. -- C Function: PyStatus _Py_InitializeMain (void) Move to the “Main” initialization phase, finish the Python initialization. No module is imported during the “Core” phase and the ‘importlib’ module is not configured: the *note Path Configuration: 3d68. is only applied during the “Main” phase. It may allow to customize Python in Python to override or tune the *note Path Configuration: 3d68, maybe install a custom *note sys.meta_path: 5e6. importer or an import hook, etc. It may become possible to calculatin the *note Path Configuration: 3d68. in Python, after the Core phase and before the Main phase, which is one of the PEP 432(2) motivation. The “Core” phase is not properly defined: what should be and what should not be available at this phase is not specified yet. The API is marked as private and provisional: the API can be modified or even be removed anytime until a proper public API is designed. Example running Python code between “Core” and “Main” initialization phases: void init_python(void) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); config._init_main = 0; /* ... customize 'config' configuration ... */ status = Py_InitializeFromConfig(&config); PyConfig_Clear(&config); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } /* Use sys.stderr because sys.stdout is only created by _Py_InitializeMain() */ int res = PyRun_SimpleString( "import sys; " "print('Run Python code before _Py_InitializeMain', " "file=sys.stderr)"); if (res < 0) { exit(1); } /* ... put more configuration code here ... */ status = _Py_InitializeMain(); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } } ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0432 (2) https://www.python.org/dev/peps/pep-0432  File: python.info, Node: Memory Management, Next: Object Implementation Support, Prev: Python Initialization Configuration, Up: Python/C API Reference Manual 7.11 Memory Management ====================== * Menu: * Overview: Overview<3>. * Raw Memory Interface:: * Memory Interface:: * Object allocators:: * Default Memory Allocators:: * Customize Memory Allocators:: * The pymalloc allocator:: * tracemalloc C API:: * Examples: Examples<34>.  File: python.info, Node: Overview<3>, Next: Raw Memory Interface, Up: Memory Management 7.11.1 Overview --------------- Memory management in Python involves a private heap containing all Python objects and data structures. The management of this private heap is ensured internally by the `Python memory manager'. The Python memory manager has different components which deal with various dynamic storage management aspects, like sharing, segmentation, preallocation or caching. At the lowest level, a raw memory allocator ensures that there is enough room in the private heap for storing all Python-related data by interacting with the memory manager of the operating system. On top of the raw memory allocator, several object-specific allocators operate on the same heap and implement distinct memory management policies adapted to the peculiarities of every object type. For example, integer objects are managed differently within the heap than strings, tuples or dictionaries because integers imply different storage requirements and speed/space tradeoffs. The Python memory manager thus delegates some of the work to the object-specific allocators, but ensures that the latter operate within the bounds of the private heap. It is important to understand that the management of the Python heap is performed by the interpreter itself and that the user has no control over it, even if they regularly manipulate object pointers to memory blocks inside that heap. The allocation of heap space for Python objects and other internal buffers is performed on demand by the Python memory manager through the Python/C API functions listed in this document. To avoid memory corruption, extension writers should never try to operate on Python objects with the functions exported by the C library: ‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’. This will result in mixed calls between the C allocator and the Python memory manager with fatal consequences, because they implement different algorithms and operate on different heaps. However, one may safely allocate and release memory blocks with the C library allocator for individual purposes, as shown in the following example: PyObject *res; char *buf = (char *) malloc(BUFSIZ); /* for I/O */ if (buf == NULL) return PyErr_NoMemory(); ...Do some I/O operation involving buf... res = PyBytes_FromString(buf); free(buf); /* malloc'ed */ return res; In this example, the memory request for the I/O buffer is handled by the C library allocator. The Python memory manager is involved only in the allocation of the bytes object returned as a result. In most situations, however, it is recommended to allocate memory from the Python heap specifically because the latter is under control of the Python memory manager. For example, this is required when the interpreter is extended with new object types written in C. Another reason for using the Python heap is the desire to `inform' the Python memory manager about the memory needs of the extension module. Even when the requested memory is used exclusively for internal, highly-specific purposes, delegating all memory requests to the Python memory manager causes the interpreter to have a more accurate image of its memory footprint as a whole. Consequently, under certain circumstances, the Python memory manager may or may not trigger appropriate actions, like garbage collection, memory compaction or other preventive procedures. Note that by using the C library allocator as shown in the previous example, the allocated memory for the I/O buffer escapes completely the Python memory manager. See also ........ The *note PYTHONMALLOC: 503. environment variable can be used to configure the memory allocators used by Python. The *note PYTHONMALLOCSTATS: ffa. environment variable can be used to print statistics of the *note pymalloc memory allocator: 5c1. every time a new pymalloc object arena is created, and on shutdown.  File: python.info, Node: Raw Memory Interface, Next: Memory Interface, Prev: Overview<3>, Up: Memory Management 7.11.2 Raw Memory Interface --------------------------- The following function sets are wrappers to the system allocator. These functions are thread-safe, the *note GIL: 506. does not need to be held. The *note default raw memory allocator: ff8. uses the following functions: ‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’; call ‘malloc(1)’ (or ‘calloc(1, 1)’) when requesting zero bytes. New in version 3.4. -- C Function: void* PyMem_RawMalloc (size_t n) Allocates `n' bytes and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. Requesting zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyMem_RawMalloc(1)’ had been called instead. The memory will not have been initialized in any way. -- C Function: void* PyMem_RawCalloc (size_t nelem, size_t elsize) Allocates `nelem' elements each whose size in bytes is `elsize' and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. The memory is initialized to zeros. Requesting zero elements or elements of size zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyMem_RawCalloc(1, 1)’ had been called instead. New in version 3.5. -- C Function: void* PyMem_RawRealloc (void *p, size_t n) Resizes the memory block pointed to by `p' to `n' bytes. The contents will be unchanged to the minimum of the old and the new sizes. If `p' is ‘NULL’, the call is equivalent to ‘PyMem_RawMalloc(n)’; else if `n' is equal to zero, the memory block is resized but is not freed, and the returned pointer is non-‘NULL’. Unless `p' is ‘NULL’, it must have been returned by a previous call to *note PyMem_RawMalloc(): 96d, *note PyMem_RawRealloc(): 96e. or *note PyMem_RawCalloc(): 7a5. If the request fails, *note PyMem_RawRealloc(): 96e. returns ‘NULL’ and `p' remains a valid pointer to the previous memory area. -- C Function: void PyMem_RawFree (void *p) Frees the memory block pointed to by `p', which must have been returned by a previous call to *note PyMem_RawMalloc(): 96d, *note PyMem_RawRealloc(): 96e. or *note PyMem_RawCalloc(): 7a5. Otherwise, or if ‘PyMem_RawFree(p)’ has been called before, undefined behavior occurs. If `p' is ‘NULL’, no operation is performed.  File: python.info, Node: Memory Interface, Next: Object allocators, Prev: Raw Memory Interface, Up: Memory Management 7.11.3 Memory Interface ----------------------- The following function sets, modeled after the ANSI C standard, but specifying behavior when requesting zero bytes, are available for allocating and releasing memory from the Python heap. The *note default memory allocator: ff8. uses the *note pymalloc memory allocator: 5c1. Warning: The *note GIL: 506. must be held when using these functions. Changed in version 3.6: The default allocator is now pymalloc instead of system ‘malloc()’. -- C Function: void* PyMem_Malloc (size_t n) Allocates `n' bytes and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. Requesting zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyMem_Malloc(1)’ had been called instead. The memory will not have been initialized in any way. -- C Function: void* PyMem_Calloc (size_t nelem, size_t elsize) Allocates `nelem' elements each whose size in bytes is `elsize' and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. The memory is initialized to zeros. Requesting zero elements or elements of size zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyMem_Calloc(1, 1)’ had been called instead. New in version 3.5. -- C Function: void* PyMem_Realloc (void *p, size_t n) Resizes the memory block pointed to by `p' to `n' bytes. The contents will be unchanged to the minimum of the old and the new sizes. If `p' is ‘NULL’, the call is equivalent to ‘PyMem_Malloc(n)’; else if `n' is equal to zero, the memory block is resized but is not freed, and the returned pointer is non-‘NULL’. Unless `p' is ‘NULL’, it must have been returned by a previous call to *note PyMem_Malloc(): 505, *note PyMem_Realloc(): 96f. or *note PyMem_Calloc(): 7a6. If the request fails, *note PyMem_Realloc(): 96f. returns ‘NULL’ and `p' remains a valid pointer to the previous memory area. -- C Function: void PyMem_Free (void *p) Frees the memory block pointed to by `p', which must have been returned by a previous call to *note PyMem_Malloc(): 505, *note PyMem_Realloc(): 96f. or *note PyMem_Calloc(): 7a6. Otherwise, or if ‘PyMem_Free(p)’ has been called before, undefined behavior occurs. If `p' is ‘NULL’, no operation is performed. The following type-oriented macros are provided for convenience. Note that `TYPE' refers to any C type. -- C Function: TYPE* PyMem_New (TYPE, size_t n) Same as *note PyMem_Malloc(): 505, but allocates ‘(n * sizeof(TYPE))’ bytes of memory. Returns a pointer cast to ‘TYPE*’. The memory will not have been initialized in any way. -- C Function: TYPE* PyMem_Resize (void *p, TYPE, size_t n) Same as *note PyMem_Realloc(): 96f, but the memory block is resized to ‘(n * sizeof(TYPE))’ bytes. Returns a pointer cast to ‘TYPE*’. On return, `p' will be a pointer to the new memory area, or ‘NULL’ in the event of failure. This is a C preprocessor macro; `p' is always reassigned. Save the original value of `p' to avoid losing memory when handling errors. -- C Function: void PyMem_Del (void *p) Same as *note PyMem_Free(): da9. In addition, the following macro sets are provided for calling the Python memory allocator directly, without involving the C API functions listed above. However, note that their use does not preserve binary compatibility across Python versions and is therefore deprecated in extension modules. * ‘PyMem_MALLOC(size)’ * ‘PyMem_NEW(type, size)’ * ‘PyMem_REALLOC(ptr, size)’ * ‘PyMem_RESIZE(ptr, type, size)’ * ‘PyMem_FREE(ptr)’ * ‘PyMem_DEL(ptr)’  File: python.info, Node: Object allocators, Next: Default Memory Allocators, Prev: Memory Interface, Up: Memory Management 7.11.4 Object allocators ------------------------ The following function sets, modeled after the ANSI C standard, but specifying behavior when requesting zero bytes, are available for allocating and releasing memory from the Python heap. The *note default object allocator: ff8. uses the *note pymalloc memory allocator: 5c1. Warning: The *note GIL: 506. must be held when using these functions. -- C Function: void* PyObject_Malloc (size_t n) Allocates `n' bytes and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. Requesting zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyObject_Malloc(1)’ had been called instead. The memory will not have been initialized in any way. -- C Function: void* PyObject_Calloc (size_t nelem, size_t elsize) Allocates `nelem' elements each whose size in bytes is `elsize' and returns a pointer of type ‘void*’ to the allocated memory, or ‘NULL’ if the request fails. The memory is initialized to zeros. Requesting zero elements or elements of size zero bytes returns a distinct non-‘NULL’ pointer if possible, as if ‘PyObject_Calloc(1, 1)’ had been called instead. New in version 3.5. -- C Function: void* PyObject_Realloc (void *p, size_t n) Resizes the memory block pointed to by `p' to `n' bytes. The contents will be unchanged to the minimum of the old and the new sizes. If `p' is ‘NULL’, the call is equivalent to ‘PyObject_Malloc(n)’; else if `n' is equal to zero, the memory block is resized but is not freed, and the returned pointer is non-‘NULL’. Unless `p' is ‘NULL’, it must have been returned by a previous call to *note PyObject_Malloc(): 508, *note PyObject_Realloc(): daa. or *note PyObject_Calloc(): 7a7. If the request fails, *note PyObject_Realloc(): daa. returns ‘NULL’ and `p' remains a valid pointer to the previous memory area. -- C Function: void PyObject_Free (void *p) Frees the memory block pointed to by `p', which must have been returned by a previous call to *note PyObject_Malloc(): 508, *note PyObject_Realloc(): daa. or *note PyObject_Calloc(): 7a7. Otherwise, or if ‘PyObject_Free(p)’ has been called before, undefined behavior occurs. If `p' is ‘NULL’, no operation is performed.  File: python.info, Node: Default Memory Allocators, Next: Customize Memory Allocators, Prev: Object allocators, Up: Memory Management 7.11.5 Default Memory Allocators -------------------------------- Default memory allocators: Configuration Name PyMem_RawMalloc PyMem_Malloc PyObject_Malloc --------------------------------------------------------------------------------------------------------------------------------------- Release build ‘"pymalloc"’ ‘malloc’ ‘pymalloc’ ‘pymalloc’ Debug build ‘"pymalloc_debug"’ ‘malloc’ + debug ‘pymalloc’ + debug ‘pymalloc’ + debug Release build, without pymalloc ‘"malloc"’ ‘malloc’ ‘malloc’ ‘malloc’ Debug build, without pymalloc ‘"malloc_debug"’ ‘malloc’ + debug ‘malloc’ + debug ‘malloc’ + debug Legend: * Name: value for *note PYTHONMALLOC: 503. environment variable * ‘malloc’: system allocators from the standard C library, C functions: ‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’ * ‘pymalloc’: *note pymalloc memory allocator: 5c1. * “+ debug”: with debug hooks installed by *note PyMem_SetupDebugHooks(): 50a.  File: python.info, Node: Customize Memory Allocators, Next: The pymalloc allocator, Prev: Default Memory Allocators, Up: Memory Management 7.11.6 Customize Memory Allocators ---------------------------------- New in version 3.4. -- C Type: PyMemAllocatorEx Structure used to describe a memory block allocator. The structure has four fields: Field Meaning ----------------------------------------------------------------------------------------------------------- ‘void *ctx’ user context passed as first argument ‘void* malloc(void *ctx, size_t size)’ allocate a memory block ‘void* calloc(void *ctx, size_t nelem, size_t elsize)’ allocate a memory block initialized with zeros ‘void* realloc(void *ctx, void *ptr, size_t new_size)’ allocate or resize a memory block ‘void free(void *ctx, void *ptr)’ free a memory block Changed in version 3.5: The ‘PyMemAllocator’ structure was renamed to *note PyMemAllocatorEx: 7ca. and a new ‘calloc’ field was added. -- C Type: PyMemAllocatorDomain Enum used to identify an allocator domain. Domains: -- C Macro: PYMEM_DOMAIN_RAW Functions: * *note PyMem_RawMalloc(): 96d. * *note PyMem_RawRealloc(): 96e. * *note PyMem_RawCalloc(): 7a5. * *note PyMem_RawFree(): 398f. -- C Macro: PYMEM_DOMAIN_MEM Functions: * *note PyMem_Malloc(): 505, * *note PyMem_Realloc(): 96f. * *note PyMem_Calloc(): 7a6. * *note PyMem_Free(): da9. -- C Macro: PYMEM_DOMAIN_OBJ Functions: * *note PyObject_Malloc(): 508. * *note PyObject_Realloc(): daa. * *note PyObject_Calloc(): 7a7. * *note PyObject_Free(): 504. -- C Function: void PyMem_GetAllocator (PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator) Get the memory block allocator of the specified domain. -- C Function: void PyMem_SetAllocator (PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator) Set the memory block allocator of the specified domain. The new allocator must return a distinct non-‘NULL’ pointer when requesting zero bytes. For the *note PYMEM_DOMAIN_RAW: ff9. domain, the allocator must be thread-safe: the *note GIL: 506. is not held when the allocator is called. If the new allocator is not a hook (does not call the previous allocator), the *note PyMem_SetupDebugHooks(): 50a. function must be called to reinstall the debug hooks on top on the new allocator. -- C Function: void PyMem_SetupDebugHooks (void) Setup hooks to detect bugs in the Python memory allocator functions. Newly allocated memory is filled with the byte ‘0xCD’ (‘CLEANBYTE’), freed memory is filled with the byte ‘0xDD’ (‘DEADBYTE’). Memory blocks are surrounded by “forbidden bytes” (‘FORBIDDENBYTE’: byte ‘0xFD’). Runtime checks: - Detect API violations, ex: *note PyObject_Free(): 504. called on a buffer allocated by *note PyMem_Malloc(): 505. - Detect write before the start of the buffer (buffer underflow) - Detect write after the end of the buffer (buffer overflow) - Check that the *note GIL: 506. is held when allocator functions of *note PYMEM_DOMAIN_OBJ: 507. (ex: *note PyObject_Malloc(): 508.) and *note PYMEM_DOMAIN_MEM: 509. (ex: *note PyMem_Malloc(): 505.) domains are called On error, the debug hooks use the *note tracemalloc: 114. module to get the traceback where a memory block was allocated. The traceback is only displayed if *note tracemalloc: 114. is tracing Python memory allocations and the memory block was traced. These hooks are *note installed by default: ff8. if Python is compiled in debug mode. The *note PYTHONMALLOC: 503. environment variable can be used to install debug hooks on a Python compiled in release mode. Changed in version 3.6: This function now also works on Python compiled in release mode. On error, the debug hooks now use *note tracemalloc: 114. to get the traceback where a memory block was allocated. The debug hooks now also check if the GIL is held when functions of *note PYMEM_DOMAIN_OBJ: 507. and *note PYMEM_DOMAIN_MEM: 509. domains are called. Changed in version 3.8: Byte patterns ‘0xCB’ (‘CLEANBYTE’), ‘0xDB’ (‘DEADBYTE’) and ‘0xFB’ (‘FORBIDDENBYTE’) have been replaced with ‘0xCD’, ‘0xDD’ and ‘0xFD’ to use the same values than Windows CRT debug ‘malloc()’ and ‘free()’.  File: python.info, Node: The pymalloc allocator, Next: tracemalloc C API, Prev: Customize Memory Allocators, Up: Memory Management 7.11.7 The pymalloc allocator ----------------------------- Python has a `pymalloc' allocator optimized for small objects (smaller or equal to 512 bytes) with a short lifetime. It uses memory mappings called “arenas” with a fixed size of 256 KiB. It falls back to *note PyMem_RawMalloc(): 96d. and *note PyMem_RawRealloc(): 96e. for allocations larger than 512 bytes. `pymalloc' is the *note default allocator: ff8. of the *note PYMEM_DOMAIN_MEM: 509. (ex: *note PyMem_Malloc(): 505.) and *note PYMEM_DOMAIN_OBJ: 507. (ex: *note PyObject_Malloc(): 508.) domains. The arena allocator uses the following functions: * ‘VirtualAlloc()’ and ‘VirtualFree()’ on Windows, * ‘mmap()’ and ‘munmap()’ if available, * ‘malloc()’ and ‘free()’ otherwise. * Menu: * Customize pymalloc Arena Allocator::  File: python.info, Node: Customize pymalloc Arena Allocator, Up: The pymalloc allocator 7.11.7.1 Customize pymalloc Arena Allocator ........................................... New in version 3.4. -- C Type: PyObjectArenaAllocator Structure used to describe an arena allocator. The structure has three fields: Field Meaning --------------------------------------------------------------------------------------------------- ‘void *ctx’ user context passed as first argument ‘void* alloc(void *ctx, size_t size)’ allocate an arena of size bytes ‘void free(void *ctx, void *ptr, size_t size)’ free an arena -- C Function: void PyObject_GetArenaAllocator (PyObjectArenaAllocator *allocator) Get the arena allocator. -- C Function: void PyObject_SetArenaAllocator (PyObjectArenaAllocator *allocator) Set the arena allocator.  File: python.info, Node: tracemalloc C API, Next: Examples<34>, Prev: The pymalloc allocator, Up: Memory Management 7.11.8 tracemalloc C API ------------------------ New in version 3.7. -- C Function: int PyTraceMalloc_Track (unsigned int domain, uintptr_t ptr, size_t size) Track an allocated memory block in the *note tracemalloc: 114. module. Return ‘0’ on success, return ‘-1’ on error (failed to allocate memory to store the trace). Return ‘-2’ if tracemalloc is disabled. If memory block is already tracked, update the existing trace. -- C Function: int PyTraceMalloc_Untrack (unsigned int domain, uintptr_t ptr) Untrack an allocated memory block in the *note tracemalloc: 114. module. Do nothing if the block was not tracked. Return ‘-2’ if tracemalloc is disabled, otherwise return ‘0’.  File: python.info, Node: Examples<34>, Prev: tracemalloc C API, Up: Memory Management 7.11.9 Examples --------------- Here is the example from section *note Overview: 3d87, rewritten so that the I/O buffer is allocated from the Python heap by using the first function set: PyObject *res; char *buf = (char *) PyMem_Malloc(BUFSIZ); /* for I/O */ if (buf == NULL) return PyErr_NoMemory(); /* ...Do some I/O operation involving buf... */ res = PyBytes_FromString(buf); PyMem_Free(buf); /* allocated with PyMem_Malloc */ return res; The same code using the type-oriented function set: PyObject *res; char *buf = PyMem_New(char, BUFSIZ); /* for I/O */ if (buf == NULL) return PyErr_NoMemory(); /* ...Do some I/O operation involving buf... */ res = PyBytes_FromString(buf); PyMem_Del(buf); /* allocated with PyMem_New */ return res; Note that in the two examples above, the buffer is always manipulated via functions belonging to the same set. Indeed, it is required to use the same memory API family for a given memory block, so that the risk of mixing different allocators is reduced to a minimum. The following code sequence contains two errors, one of which is labeled as `fatal' because it mixes two different allocators operating on different heaps. char *buf1 = PyMem_New(char, BUFSIZ); char *buf2 = (char *) malloc(BUFSIZ); char *buf3 = (char *) PyMem_Malloc(BUFSIZ); ... PyMem_Del(buf3); /* Wrong -- should be PyMem_Free() */ free(buf2); /* Right -- allocated via malloc() */ free(buf1); /* Fatal -- should be PyMem_Del() */ In addition to the functions aimed at handling raw memory blocks from the Python heap, objects in Python are allocated and released with *note PyObject_New(): 2d2, *note PyObject_NewVar(): 2d3. and *note PyObject_Del(): e16. These will be explained in the next chapter on defining and implementing new object types in C.  File: python.info, Node: Object Implementation Support, Next: API and ABI Versioning, Prev: Memory Management, Up: Python/C API Reference Manual 7.12 Object Implementation Support ================================== This chapter describes the functions, types, and macros used when defining new object types. * Menu: * Allocating Objects on the Heap:: * Common Object Structures:: * Type Objects: Type Objects<3>. * Number Object Structures:: * Mapping Object Structures:: * Sequence Object Structures:: * Buffer Object Structures:: * Async Object Structures:: * Slot Type typedefs:: * Examples: Examples<35>. * Supporting Cyclic Garbage Collection::  File: python.info, Node: Allocating Objects on the Heap, Next: Common Object Structures, Up: Object Implementation Support 7.12.1 Allocating Objects on the Heap ------------------------------------- -- C Function: PyObject* _PyObject_New (PyTypeObject *type) `Return value: New reference.' -- C Function: PyVarObject* _PyObject_NewVar (PyTypeObject *type, Py_ssize_t size) `Return value: New reference.' -- C Function: PyObject* PyObject_Init (PyObject *op, PyTypeObject *type) `Return value: Borrowed reference.' Initialize a newly-allocated object `op' with its type and initial reference. Returns the initialized object. If `type' indicates that the object participates in the cyclic garbage detector, it is added to the detector’s set of observed objects. Other fields of the object are not affected. -- C Function: PyVarObject* PyObject_InitVar (PyVarObject *op, PyTypeObject *type, Py_ssize_t size) `Return value: Borrowed reference.' This does everything *note PyObject_Init(): 26f. does, and also initializes the length information for a variable-size object. -- C Function: TYPE* PyObject_New (TYPE, PyTypeObject *type) `Return value: New reference.' Allocate a new Python object using the C structure type `TYPE' and the Python type object `type'. Fields not defined by the Python object header are not initialized; the object’s reference count will be one. The size of the memory allocation is determined from the *note tp_basicsize: 3879. field of the type object. -- C Function: TYPE* PyObject_NewVar (TYPE, PyTypeObject *type, Py_ssize_t size) `Return value: New reference.' Allocate a new Python object using the C structure type `TYPE' and the Python type object `type'. Fields not defined by the Python object header are not initialized. The allocated memory allows for the `TYPE' structure plus `size' fields of the size given by the *note tp_itemsize: 3878. field of `type'. This is useful for implementing objects like tuples, which are able to determine their size at construction time. Embedding the array of fields into the same allocation decreases the number of allocations, improving the memory management efficiency. -- C Function: void PyObject_Del (void *op) Releases memory allocated to an object using *note PyObject_New(): 2d2. or *note PyObject_NewVar(): 2d3. This is normally called from the *note tp_dealloc: 387f. handler specified in the object’s type. The fields of the object should not be accessed after this call as the memory is no longer a valid Python object. -- C Variable: PyObject _Py_NoneStruct Object which is visible in Python as ‘None’. This should only be accessed using the *note Py_None: 3844. macro, which evaluates to a pointer to this object. See also ........ *note PyModule_Create(): 3847. To allocate and create extension modules.  File: python.info, Node: Common Object Structures, Next: Type Objects<3>, Prev: Allocating Objects on the Heap, Up: Object Implementation Support 7.12.2 Common Object Structures ------------------------------- There are a large number of structures which are used in the definition of object types for Python. This section describes these structures and how they are used. All Python objects ultimately share a small number of fields at the beginning of the object’s representation in memory. These are represented by the *note PyObject: 4ba. and *note PyVarObject: 3da6. types, which are defined, in turn, by the expansions of some macros also used, whether directly or indirectly, in the definition of all other Python objects. -- C Type: PyObject All object types are extensions of this type. This is a type which contains the information Python needs to treat a pointer to an object as an object. In a normal “release” build, it contains only the object’s reference count and a pointer to the corresponding type object. Nothing is actually declared to be a *note PyObject: 4ba, but every pointer to a Python object can be cast to a *note PyObject*: 4ba. Access to the members must be done by using the macros *note Py_REFCNT: 3875. and *note Py_TYPE: 3876. -- C Type: PyVarObject This is an extension of *note PyObject: 4ba. that adds the ‘ob_size’ field. This is only used for objects that have some notion of `length'. This type does not often appear in the Python/C API. Access to the members must be done by using the macros *note Py_REFCNT: 3875, *note Py_TYPE: 3876, and *note Py_SIZE: 3da7. -- C Macro: PyObject_HEAD This is a macro used when declaring new types which represent objects without a varying length. The PyObject_HEAD macro expands to: PyObject ob_base; See documentation of *note PyObject: 4ba. above. -- C Macro: PyObject_VAR_HEAD This is a macro used when declaring new types which represent objects with a length that varies from instance to instance. The PyObject_VAR_HEAD macro expands to: PyVarObject ob_base; See documentation of *note PyVarObject: 3da6. above. -- C Macro: Py_TYPE (o) This macro is used to access the ‘ob_type’ member of a Python object. It expands to: (((PyObject*)(o))->ob_type) -- C Macro: Py_REFCNT (o) This macro is used to access the ‘ob_refcnt’ member of a Python object. It expands to: (((PyObject*)(o))->ob_refcnt) -- C Macro: Py_SIZE (o) This macro is used to access the ‘ob_size’ member of a Python object. It expands to: (((PyVarObject*)(o))->ob_size) -- C Macro: PyObject_HEAD_INIT (type) This is a macro which expands to initialization values for a new *note PyObject: 4ba. type. This macro expands to: _PyObject_EXTRA_INIT 1, type, -- C Macro: PyVarObject_HEAD_INIT (type, size) This is a macro which expands to initialization values for a new *note PyVarObject: 3da6. type, including the ‘ob_size’ field. This macro expands to: _PyObject_EXTRA_INIT 1, type, size, -- C Type: PyCFunction Type of the functions used to implement most Python callables in C. Functions of this type take two *note PyObject*: 4ba. parameters and return one such value. If the return value is ‘NULL’, an exception shall have been set. If not ‘NULL’, the return value is interpreted as the return value of the function as exposed in Python. The function must return a new reference. -- C Type: PyCFunctionWithKeywords Type of the functions used to implement Python callables in C with signature ‘METH_VARARGS | METH_KEYWORDS’. -- C Type: _PyCFunctionFast Type of the functions used to implement Python callables in C with signature *note METH_FASTCALL: 3dad. -- C Type: _PyCFunctionFastWithKeywords Type of the functions used to implement Python callables in C with signature ‘METH_FASTCALL | METH_KEYWORDS’. -- C Type: PyMethodDef Structure used to describe a method of an extension type. This structure has four fields: Field C Type Meaning ------------------------------------------------------------------------------- ‘ml_name’ const char * name of the method ‘ml_meth’ PyCFunction pointer to the C implementation ‘ml_flags’ int flag bits indicating how the call should be constructed ‘ml_doc’ const char * points to the contents of the docstring The ‘ml_meth’ is a C function pointer. The functions may be of different types, but they always return *note PyObject*: 4ba. If the function is not of the *note PyCFunction: ddb, the compiler will require a cast in the method table. Even though *note PyCFunction: ddb. defines the first parameter as *note PyObject*: 4ba, it is common that the method implementation uses the specific C type of the `self' object. The ‘ml_flags’ field is a bitfield which can include the following flags. The individual flags indicate either a calling convention or a binding convention. There are four basic calling conventions for positional arguments and two of them can be combined with ‘METH_KEYWORDS’ to support also keyword arguments. So there are a total of 6 calling conventions: -- Data: METH_VARARGS This is the typical calling convention, where the methods have the type *note PyCFunction: ddb. The function expects two *note PyObject*: 4ba. values. The first one is the `self' object for methods; for module functions, it is the module object. The second parameter (often called `args') is a tuple object representing all arguments. This parameter is typically processed using *note PyArg_ParseTuple(): 26a. or *note PyArg_UnpackTuple(): e46. -- Data: METH_VARARGS | METH_KEYWORDS Methods with these flags must be of type *note PyCFunctionWithKeywords: 3dab. The function expects three parameters: `self', `args', `kwargs' where `kwargs' is a dictionary of all the keyword arguments or possibly ‘NULL’ if there are no keyword arguments. The parameters are typically processed using *note PyArg_ParseTupleAndKeywords(): 5ca. -- Data: METH_FASTCALL Fast calling convention supporting only positional arguments. The methods have the type *note _PyCFunctionFast: 3dac. The first parameter is `self', the second parameter is a C array of *note PyObject*: 4ba. values indicating the arguments and the third parameter is the number of arguments (the length of the array). This is not part of the *note limited API: 3905. New in version 3.7. -- Data: METH_FASTCALL | METH_KEYWORDS Extension of *note METH_FASTCALL: 3dad. supporting also keyword arguments, with methods of type *note _PyCFunctionFastWithKeywords: 3dae. Keyword arguments are passed the same way as in the vectorcall protocol: there is an additional fourth *note PyObject*: 4ba. parameter which is a tuple representing the names of the keyword arguments or possibly ‘NULL’ if there are no keywords. The values of the keyword arguments are stored in the `args' array, after the positional arguments. This is not part of the *note limited API: 3905. New in version 3.7. -- Data: METH_NOARGS Methods without parameters don’t need to check whether arguments are given if they are listed with the *note METH_NOARGS: e18. flag. They need to be of type *note PyCFunction: ddb. The first parameter is typically named `self' and will hold a reference to the module or object instance. In all cases the second parameter will be ‘NULL’. -- Data: METH_O Methods with a single object argument can be listed with the *note METH_O: e47. flag, instead of invoking *note PyArg_ParseTuple(): 26a. with a ‘"O"’ argument. They have the type *note PyCFunction: ddb, with the `self' parameter, and a *note PyObject*: 4ba. parameter representing the single argument. These two constants are not used to indicate the calling convention but the binding when use with methods of classes. These may not be used for functions defined for modules. At most one of these flags may be set for any given method. -- Data: METH_CLASS The method will be passed the type object as the first parameter rather than an instance of the type. This is used to create `class methods', similar to what is created when using the *note classmethod(): 1d8. built-in function. -- Data: METH_STATIC The method will be passed ‘NULL’ as the first parameter rather than an instance of the type. This is used to create `static methods', similar to what is created when using the *note staticmethod(): 1d9. built-in function. One other constant controls whether a method is loaded in place of another definition with the same method name. -- Data: METH_COEXIST The method will be loaded in place of existing definitions. Without `METH_COEXIST', the default is to skip repeated definitions. Since slot wrappers are loaded before the method table, the existence of a `sq_contains' slot, for example, would generate a wrapped method named *note __contains__(): d28. and preclude the loading of a corresponding PyCFunction with the same name. With the flag defined, the PyCFunction will be loaded in place of the wrapper object and will co-exist with the slot. This is helpful because calls to PyCFunctions are optimized more than wrapper object calls. -- C Type: PyMemberDef Structure which describes an attribute of a type which corresponds to a C struct member. Its fields are: Field C Type Meaning ------------------------------------------------------------------------------- ‘name’ const char * name of the member ‘type’ int the type of the member in the C struct ‘offset’ Py_ssize_t the offset in bytes that the member is located on the type’s object struct ‘flags’ int flag bits indicating if the field should be read-only or writable ‘doc’ const char * points to the contents of the docstring ‘type’ can be one of many ‘T_’ macros corresponding to various C types. When the member is accessed in Python, it will be converted to the equivalent Python type. Macro name C type ------------------------------------------- T_SHORT short T_INT int T_LONG long T_FLOAT float T_DOUBLE double T_STRING const char * T_OBJECT PyObject * T_OBJECT_EX PyObject * T_CHAR char T_BYTE char T_UBYTE unsigned char T_UINT unsigned int T_USHORT unsigned short T_ULONG unsigned long T_BOOL char T_LONGLONG long long T_ULONGLONG unsigned long long T_PYSSIZET Py_ssize_t ‘T_OBJECT’ and ‘T_OBJECT_EX’ differ in that ‘T_OBJECT’ returns ‘None’ if the member is ‘NULL’ and ‘T_OBJECT_EX’ raises an *note AttributeError: 39b. Try to use ‘T_OBJECT_EX’ over ‘T_OBJECT’ because ‘T_OBJECT_EX’ handles use of the *note del: f02. statement on that attribute more correctly than ‘T_OBJECT’. ‘flags’ can be ‘0’ for write and read access or ‘READONLY’ for read-only access. Using ‘T_STRING’ for *note type: 608. implies ‘READONLY’. ‘T_STRING’ data is interpreted as UTF-8. Only ‘T_OBJECT’ and ‘T_OBJECT_EX’ members can be deleted. (They are set to ‘NULL’). -- C Type: PyGetSetDef Structure to define property-like access for a type. See also description of the *note PyTypeObject.tp_getset: 388a. slot. Field C Type Meaning --------------------------------------------------------------------------------- name const char * attribute name get getter C Function to get the attribute set setter optional C function to set or delete the attribute, if omitted the attribute is readonly doc const char * optional docstring closure void * optional function pointer, providing additional data for getter and setter The ‘get’ function takes one *note PyObject*: 4ba. parameter (the instance) and a function pointer (the associated ‘closure’): typedef PyObject *(*getter)(PyObject *, void *); It should return a new reference on success or ‘NULL’ with a set exception on failure. ‘set’ functions take two *note PyObject*: 4ba. parameters (the instance and the value to be set) and a function pointer (the associated ‘closure’): typedef int (*setter)(PyObject *, PyObject *, void *); In case the attribute should be deleted the second parameter is ‘NULL’. Should return ‘0’ on success or ‘-1’ with a set exception on failure.  File: python.info, Node: Type Objects<3>, Next: Number Object Structures, Prev: Common Object Structures, Up: Object Implementation Support 7.12.3 Type Objects ------------------- Perhaps one of the most important structures of the Python object system is the structure that defines a new type: the *note PyTypeObject: 2d6. structure. Type objects can be handled using any of the ‘PyObject_*()’ or ‘PyType_*()’ functions, but do not offer much that’s interesting to most Python applications. These objects are fundamental to how objects behave, so they are very important to the interpreter itself and to any extension module that implements new types. Type objects are fairly large compared to most of the standard types. The reason for the size is that each type object stores a large number of values, mostly C function pointers, each of which implements a small part of the type’s functionality. The fields of the type object are examined in detail in this section. The fields will be described in the order in which they occur in the structure. In addition to the following quick reference, the *note Examples: 3db2. section provides at-a-glance insight into the meaning and use of *note PyTypeObject: 2d6. * Menu: * Quick Reference:: * PyTypeObject Definition:: * PyObject Slots:: * PyVarObject Slots:: * PyTypeObject Slots:: * Heap Types::  File: python.info, Node: Quick Reference, Next: PyTypeObject Definition, Up: Type Objects<3> 7.12.3.1 Quick Reference ........................ * Menu: * “tp slots”:: * sub-slots:: * slot typedefs::  File: python.info, Node: “tp slots”, Next: sub-slots, Up: Quick Reference 7.12.3.2 “tp slots” ................... PyTypeObject Slot *note Type: 3db6. special Info (1) methods/attrs (2) --------------------------------------------------------------------------------------------- O T D I <R> const char * __name__ X X *note tp_name: 389b. *note tp_basicsize: 3879.Py_ssize_t X X X *note tp_itemsize: 3878.Py_ssize_t X X *note tp_dealloc: 387f.*note destructor: 3db7. X X X *note tp_vectorcall_offset: 3a11.Py_ssize_t ? (*note tp_getattr: 38a2.)*note getattrfunc: 3db8.__getattribute__, G __getattr__ (*note tp_setattr: 38a3.)*note setattrfunc: 3db9.__setattr__, G __delattr__ *note tp_as_async: 3dba.*note PyAsyncMethods: 3ac7.*note sub-slots: 3dbb. % * *note tp_repr: 389a. *note reprfunc: 3dbc. __repr__ X X X *note tp_as_number: 3dbd.*note PyNumberMethods: d81.*note sub-slots: 3dbb. % * *note tp_as_sequence: 3dbe.*note PySequenceMethods: 38aa.*note sub-slots: 3dbb. % * *note tp_as_mapping: 3dbf.*note PyMappingMethods: 38ab.*note sub-slots: 3dbb. % * *note tp_hash: 38ac. *note hashfunc: 3dc0. __hash__ X G *note tp_call: 38ad. *note ternaryfunc: 3dc1.__call__ X X *note tp_str: 389c. *note reprfunc: 3dbc. __str__ X X *note tp_getattro: 389f.*note getattrofunc: 3dc2.__getattribute__, X X G __getattr__ *note tp_setattro: 38a0.*note setattrofunc: 3dc3.__setattr__, X X G __delattr__ *note tp_as_buffer: 3dc4.*note PyBufferProcs: 3dc5. % * *note tp_flags: 3ab6. unsigned long X X ? *note tp_doc: 387b. const char * __doc__ X X *note tp_traverse: 33e8.*note traverseproc: 3dc6. X G *note tp_clear: 3898. *note inquiry: 3dc7. X G *note tp_richcompare: 38a5.*note richcmpfunc: 3dc8.__lt__, __le__, X G __eq__, __ne__, __gt__, __ge__ *note tp_weaklistoffset: 38af.Py_ssize_t X ? *note tp_iter: e30. *note getiterfunc: 3dc9.__iter__ X *note tp_iternext: e31.*note iternextfunc: 3dca.__next__ X *note tp_methods: 3886.*note PyMethodDef: e1b. X X [] *note tp_members: 3884.*note PyMemberDef: 426. X [] *note tp_getset: 388a. *note PyGetSetDef: 427. X X [] *note tp_base: 3890. *note PyTypeObject: 2d6.__base__ X * *note tp_dict: 3aca. *note PyObject: 4ba. __dict__ ? * *note tp_descr_get: 3dcb.*note descrgetfunc: 3dcc.__get__ X *note tp_descr_set: 3dcd.*note descrsetfunc: 3dce.__set__, __delete__ X *note tp_dictoffset: 3acf.Py_ssize_t X ? *note tp_init: 3883. *note initproc: 3dcf. __init__ X X X *note tp_alloc: 3881. *note allocfunc: 3dd0. X ? ? *note tp_new: 387c. *note newfunc: 3dd1. __new__ X X ? ? *note tp_free: 3880. *note freefunc: 3dd2. X X ? ? *note tp_is_gc: 3dd3. *note inquiry: 3dc7. X X <*note tp_bases: 3dd4.>*note PyObject: 4ba. __bases__ ~ * <*note tp_mro: 3acb.> *note PyObject: 4ba. __mro__ ~ * [*note tp_cache: 3acc.]*note PyObject: 4ba. * [*note tp_subclasses: 3acd.]*note PyObject: 4ba.__subclasses__ * [*note tp_weaklist: 3ace.]*note PyObject: 4ba. * (*note tp_del: 3dd5.) *note destructor: 3db7. [*note tp_version_tag: 3dd6.]unsigned int *note tp_finalize: 2d7.*note destructor: 3db7.__del__ X If ‘COUNT_ALLOCS’ is defined then the following (internal-only) fields exist as well: * *note tp_allocs: 3dd7. * *note tp_frees: 3dd8. * *note tp_maxalloc: 3dd9. * *note tp_prev: 3dda. * *note tp_next: 3ddb. ---------- Footnotes ---------- (1) (1) A slot name in parentheses indicates it is (effectively) deprecated. Names in angle brackets should be treated as read-only. Names in square brackets are for internal use only. “<R>” (as a prefix) means the field is required (must be non-‘NULL’). (2) (2) Columns: `“O”': set on ‘PyBaseObject_Type’ `“T”': set on *note PyType_Type: 3ab1. `“D”': default (if slot is set to ‘NULL’) X - PyType_Ready sets this value if it is NULL ~ - PyType_Ready always sets this value (it should be NULL) ? - PyType_Ready may set this value depending on other slots Also see the inheritance column ("I"). `“I”': inheritance X - type slot is inherited via PyType_Ready if defined with a NULL value % - the slots of the sub-struct are inherited individually G - inherited, but only in combination with other slots; see the slot's description ? - it's complicated; see the slot's description Note that some slots are effectively inherited through the normal attribute lookup chain.  File: python.info, Node: sub-slots, Next: slot typedefs, Prev: “tp slots”, Up: Quick Reference 7.12.3.3 sub-slots .................. Slot *note Type: 3db6. special methods ---------------------------------------------------------------------- *note am_await: 3ddd. *note unaryfunc: 3dde.__await__ *note am_aiter: 3ddf. *note unaryfunc: 3dde.__aiter__ *note am_anext: 3de0. *note unaryfunc: 3dde.__anext__ *note nb_add: 3ac8. *note binaryfunc: 3de1.__add__ __radd__ *note nb_inplace_add: 3de2. *note binaryfunc: 3de1.__iadd__ *note nb_subtract: 3de3. *note binaryfunc: 3de1.__sub__ __rsub__ *note nb_inplace_subtract: 3de4.*note binaryfunc: 3de1.__sub__ *note nb_multiply: 3de5. *note binaryfunc: 3de1.__mul__ __rmul__ *note nb_inplace_multiply: 3de6.*note binaryfunc: 3de1.__mul__ *note nb_remainder: 3de7. *note binaryfunc: 3de1.__mod__ __rmod__ *note nb_inplace_remainder: 3de8.*note binaryfunc: 3de1.__mod__ *note nb_divmod: 3de9. *note binaryfunc: 3de1.__divmod__ __rdivmod__ *note nb_power: 3dea. *note ternaryfunc: 3dc1.__pow__ __rpow__ *note nb_inplace_power: 3deb. *note ternaryfunc: 3dc1.__pow__ *note nb_negative: 3dec. *note unaryfunc: 3dde.__neg__ *note nb_positive: 3ded. *note unaryfunc: 3dde.__pos__ *note nb_absolute: 3dee. *note unaryfunc: 3dde.__abs__ *note nb_bool: 3def. *note inquiry: 3dc7. __bool__ *note nb_invert: 3df0. *note unaryfunc: 3dde.__invert__ *note nb_lshift: 3df1. *note binaryfunc: 3de1.__lshift__ __rlshift__ *note nb_inplace_lshift: 3df2. *note binaryfunc: 3de1.__lshift__ *note nb_rshift: 3df3. *note binaryfunc: 3de1.__rshift__ __rrshift__ *note nb_inplace_rshift: 3df4. *note binaryfunc: 3de1.__rshift__ *note nb_and: 3df5. *note binaryfunc: 3de1.__and__ __rand__ *note nb_inplace_and: 3df6. *note binaryfunc: 3de1.__and__ *note nb_xor: 3df7. *note binaryfunc: 3de1.__xor__ __rxor__ *note nb_inplace_xor: 3df8. *note binaryfunc: 3de1.__xor__ *note nb_or: 3df9. *note binaryfunc: 3de1.__or__ __ror__ *note nb_inplace_or: 3dfa. *note binaryfunc: 3de1.__or__ *note nb_int: 3dfb. *note unaryfunc: 3dde.__int__ *note nb_reserved: 3dfc. void * *note nb_float: 3dfd. *note unaryfunc: 3dde.__float__ *note nb_floor_divide: 3dfe. *note binaryfunc: 3de1.__floordiv__ *note nb_inplace_floor_divide: 3dff.*note binaryfunc: 3de1.__floordiv__ *note nb_true_divide: 3e00. *note binaryfunc: 3de1.__truediv__ *note nb_inplace_true_divide: 3e01.*note binaryfunc: 3de1.__truediv__ *note nb_index: 3e02. *note unaryfunc: 3dde.__index__ *note nb_matrix_multiply: 3e03.*note binaryfunc: 3de1.__matmul__ __rmatmul__ *note nb_inplace_matrix_multiply: 3e04.*note binaryfunc: 3de1.__matmul__ *note mp_length: 3e05. *note lenfunc: 3e06. __len__ *note mp_subscript: 3e07. *note binaryfunc: 3de1.__getitem__ *note mp_ass_subscript: 3e08. *note objobjargproc: 3e09.__setitem__, __delitem__ *note sq_length: 3ac9. *note lenfunc: 3e06. __len__ *note sq_concat: 3e0a. *note binaryfunc: 3de1.__add__ *note sq_repeat: 3e0b. *note ssizeargfunc: 3e0c.__mul__ *note sq_item: 3e0d. *note ssizeargfunc: 3e0c.__getitem__ *note sq_ass_item: 3e0e. *note ssizeobjargproc: 3e0f.__setitem__ __delitem__ *note sq_contains: 3e10. *note objobjproc: 3e11.__contains__ *note sq_inplace_concat: 3e12. *note binaryfunc: 3de1.__iadd__ *note sq_inplace_repeat: 3e13. *note ssizeargfunc: 3e0c.__imul__ *note bf_getbuffer: 3ad0. *note getbufferproc(): 3e14. *note bf_releasebuffer: 39c9. *note releasebufferproc(): 3e15.  File: python.info, Node: slot typedefs, Prev: sub-slots, Up: Quick Reference 7.12.3.4 slot typedefs ...................... typedef Parameter Types Return Type ----------------------------------------------------------------------------------------------- *note allocfunc: 3dd0. *note PyTypeObject: 2d6. * *note PyObject: 4ba. * Py_ssize_t *note destructor: 3db7. void * void *note freefunc: 3dd2. void * void *note traverseproc: 3dc6. void * int *note visitproc: 3e17. void * *note newfunc: 3dd1. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note initproc: 3dcf. *note PyObject: 4ba. * int *note PyObject: 4ba. * *note PyObject: 4ba. * *note reprfunc: 3dbc. *note PyObject: 4ba. * *note PyObject: 4ba. * *note getattrfunc: 3db8. *note PyObject: 4ba. * *note PyObject: 4ba. * const char * *note setattrfunc: 3db9. *note PyObject: 4ba. * int const char * *note PyObject: 4ba. * *note getattrofunc: 3dc2. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note setattrofunc: 3dc3. *note PyObject: 4ba. * int *note PyObject: 4ba. * *note PyObject: 4ba. * *note descrgetfunc: 3dcc. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note descrsetfunc: 3dce. *note PyObject: 4ba. * int *note PyObject: 4ba. * *note PyObject: 4ba. * *note hashfunc: 3dc0. *note PyObject: 4ba. * Py_hash_t *note richcmpfunc: 3dc8. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * int *note getiterfunc: 3dc9. *note PyObject: 4ba. * *note PyObject: 4ba. * *note iternextfunc: 3dca. *note PyObject: 4ba. * *note PyObject: 4ba. * *note lenfunc: 3e06. *note PyObject: 4ba. * Py_ssize_t *note getbufferproc: 3e14. *note PyObject: 4ba. * int *note Py_buffer: b1b. * int *note releasebufferproc: 3e15. *note PyObject: 4ba. * void *note Py_buffer: b1b. * *note inquiry: 3dc7. void * int *note unaryfunc: 3dde. *note PyObject: 4ba. * *note PyObject: 4ba. * *note binaryfunc: 3de1. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note ternaryfunc: 3dc1. *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note PyObject: 4ba. * *note ssizeargfunc: 3e0c. *note PyObject: 4ba. * *note PyObject: 4ba. * Py_ssize_t *note ssizeobjargproc: 3e0f. *note PyObject: 4ba. * int Py_ssize_t *note objobjproc: 3e11. *note PyObject: 4ba. * int *note PyObject: 4ba. * *note objobjargproc: 3e09. *note PyObject: 4ba. * int *note PyObject: 4ba. * *note PyObject: 4ba. * See *note Slot Type typedefs: 3e18. below for more detail.  File: python.info, Node: PyTypeObject Definition, Next: PyObject Slots, Prev: Quick Reference, Up: Type Objects<3> 7.12.3.5 PyTypeObject Definition ................................ The structure definition for *note PyTypeObject: 2d6. can be found in ‘Include/object.h’. For convenience of reference, this repeats the definition found there: typedef struct _typeobject { PyObject_VAR_HEAD const char *tp_name; /* For printing, in format "<module>.<name>" */ Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */ /* Methods to implement standard operations */ destructor tp_dealloc; Py_ssize_t tp_vectorcall_offset; getattrfunc tp_getattr; setattrfunc tp_setattr; PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2) or tp_reserved (Python 3) */ reprfunc tp_repr; /* Method suites for standard classes */ PyNumberMethods *tp_as_number; PySequenceMethods *tp_as_sequence; PyMappingMethods *tp_as_mapping; /* More standard operations (here for binary compatibility) */ hashfunc tp_hash; ternaryfunc tp_call; reprfunc tp_str; getattrofunc tp_getattro; setattrofunc tp_setattro; /* Functions to access object as input/output buffer */ PyBufferProcs *tp_as_buffer; /* Flags to define presence of optional/expanded features */ unsigned long tp_flags; const char *tp_doc; /* Documentation string */ /* call function for all accessible objects */ traverseproc tp_traverse; /* delete references to contained objects */ inquiry tp_clear; /* rich comparisons */ richcmpfunc tp_richcompare; /* weak reference enabler */ Py_ssize_t tp_weaklistoffset; /* Iterators */ getiterfunc tp_iter; iternextfunc tp_iternext; /* Attribute descriptor and subclassing stuff */ struct PyMethodDef *tp_methods; struct PyMemberDef *tp_members; struct PyGetSetDef *tp_getset; struct _typeobject *tp_base; PyObject *tp_dict; descrgetfunc tp_descr_get; descrsetfunc tp_descr_set; Py_ssize_t tp_dictoffset; initproc tp_init; allocfunc tp_alloc; newfunc tp_new; freefunc tp_free; /* Low-level free-memory routine */ inquiry tp_is_gc; /* For PyObject_IS_GC */ PyObject *tp_bases; PyObject *tp_mro; /* method resolution order */ PyObject *tp_cache; PyObject *tp_subclasses; PyObject *tp_weaklist; destructor tp_del; /* Type attribute cache version tag. Added in version 2.6 */ unsigned int tp_version_tag; destructor tp_finalize; } PyTypeObject;  File: python.info, Node: PyObject Slots, Next: PyVarObject Slots, Prev: PyTypeObject Definition, Up: Type Objects<3> 7.12.3.6 PyObject Slots ....................... The type object structure extends the *note PyVarObject: 3da6. structure. The ‘ob_size’ field is used for dynamic types (created by ‘type_new()’, usually called from a class statement). Note that *note PyType_Type: 3ab1. (the metatype) initializes *note tp_itemsize: 3878, which means that its instances (i.e. type objects) `must' have the ‘ob_size’ field. -- C Member: PyObject* PyObject._ob_next -- C Member: PyObject* PyObject._ob_prev These fields are only present when the macro ‘Py_TRACE_REFS’ is defined. Their initialization to ‘NULL’ is taken care of by the ‘PyObject_HEAD_INIT’ macro. For statically allocated objects, these fields always remain ‘NULL’. For dynamically allocated objects, these two fields are used to link the object into a doubly-linked list of `all' live objects on the heap. This could be used for various debugging purposes; currently the only use is to print the objects that are still alive at the end of a run when the environment variable *note PYTHONDUMPREFS: 159. is set. `Inheritance:' These fields are not inherited by subtypes. -- C Member: Py_ssize_t PyObject.ob_refcnt This is the type object’s reference count, initialized to ‘1’ by the ‘PyObject_HEAD_INIT’ macro. Note that for statically allocated type objects, the type’s instances (objects whose ‘ob_type’ points back to the type) do `not' count as references. But for dynamically allocated type objects, the instances `do' count as references. `Inheritance:' This field is not inherited by subtypes. -- C Member: PyTypeObject* PyObject.ob_type This is the type’s type, in other words its metatype. It is initialized by the argument to the ‘PyObject_HEAD_INIT’ macro, and its value should normally be ‘&PyType_Type’. However, for dynamically loadable extension modules that must be usable on Windows (at least), the compiler complains that this is not a valid initializer. Therefore, the convention is to pass ‘NULL’ to the ‘PyObject_HEAD_INIT’ macro and to initialize this field explicitly at the start of the module’s initialization function, before doing anything else. This is typically done like this: Foo_Type.ob_type = &PyType_Type; This should be done before any instances of the type are created. *note PyType_Ready(): 3882. checks if ‘ob_type’ is ‘NULL’, and if so, initializes it to the ‘ob_type’ field of the base class. *note PyType_Ready(): 3882. will not change this field if it is non-zero. `Inheritance:' This field is inherited by subtypes.  File: python.info, Node: PyVarObject Slots, Next: PyTypeObject Slots, Prev: PyObject Slots, Up: Type Objects<3> 7.12.3.7 PyVarObject Slots .......................... -- C Member: Py_ssize_t PyVarObject.ob_size For statically allocated type objects, this should be initialized to zero. For dynamically allocated type objects, this field has a special internal meaning. `Inheritance:' This field is not inherited by subtypes.  File: python.info, Node: PyTypeObject Slots, Next: Heap Types, Prev: PyVarObject Slots, Up: Type Objects<3> 7.12.3.8 PyTypeObject Slots ........................... Each slot has a section describing inheritance. If *note PyType_Ready(): 3882. may set a value when the field is set to ‘NULL’ then there will also be a “Default” section. (Note that many fields set on ‘PyBaseObject_Type’ and *note PyType_Type: 3ab1. effectively act as defaults.) -- C Member: const char* PyTypeObject.tp_name Pointer to a NUL-terminated string containing the name of the type. For types that are accessible as module globals, the string should be the full module name, followed by a dot, followed by the type name; for built-in types, it should be just the type name. If the module is a submodule of a package, the full package name is part of the full module name. For example, a type named ‘T’ defined in module ‘M’ in subpackage ‘Q’ in package ‘P’ should have the *note tp_name: 389b. initializer ‘"P.Q.M.T"’. For dynamically allocated type objects, this should just be the type name, and the module name explicitly stored in the type dict as the value for key ‘'__module__'’. For statically allocated type objects, the tp_name field should contain a dot. Everything before the last dot is made accessible as the ‘__module__’ attribute, and everything after the last dot is made accessible as the *note __name__: c67. attribute. If no dot is present, the entire *note tp_name: 389b. field is made accessible as the *note __name__: c67. attribute, and the ‘__module__’ attribute is undefined (unless explicitly set in the dictionary, as explained above). This means your type will be impossible to pickle. Additionally, it will not be listed in module documentations created with pydoc. This field must not be ‘NULL’. It is the only required field in *note PyTypeObject(): 2d6. (other than potentially *note tp_itemsize: 3878.). `Inheritance:' This field is not inherited by subtypes. -- C Member: Py_ssize_t PyTypeObject.tp_basicsize -- C Member: Py_ssize_t PyTypeObject.tp_itemsize These fields allow calculating the size in bytes of instances of the type. There are two kinds of types: types with fixed-length instances have a zero *note tp_itemsize: 3878. field, types with variable-length instances have a non-zero *note tp_itemsize: 3878. field. For a type with fixed-length instances, all instances have the same size, given in *note tp_basicsize: 3879. For a type with variable-length instances, the instances must have an ‘ob_size’ field, and the instance size is *note tp_basicsize: 3879. plus N times *note tp_itemsize: 3878, where N is the “length” of the object. The value of N is typically stored in the instance’s ‘ob_size’ field. There are exceptions: for example, ints use a negative ‘ob_size’ to indicate a negative number, and N is ‘abs(ob_size)’ there. Also, the presence of an ‘ob_size’ field in the instance layout doesn’t mean that the instance structure is variable-length (for example, the structure for the list type has fixed-length instances, yet those instances have a meaningful ‘ob_size’ field). The basic size includes the fields in the instance declared by the macro *note PyObject_HEAD: c72. or *note PyObject_VAR_HEAD: 3da8. (whichever is used to declare the instance struct) and this in turn includes the ‘_ob_prev’ and ‘_ob_next’ fields if they are present. This means that the only correct way to get an initializer for the *note tp_basicsize: 3879. is to use the ‘sizeof’ operator on the struct used to declare the instance layout. The basic size does not include the GC header size. A note about alignment: if the variable items require a particular alignment, this should be taken care of by the value of *note tp_basicsize: 3879. Example: suppose a type implements an array of ‘double’. *note tp_itemsize: 3878. is ‘sizeof(double)’. It is the programmer’s responsibility that *note tp_basicsize: 3879. is a multiple of ‘sizeof(double)’ (assuming this is the alignment requirement for ‘double’). For any type with variable-length instances, this field must not be ‘NULL’. `Inheritance:' These fields are inherited separately by subtypes. If the base type has a non-zero *note tp_itemsize: 3878, it is generally not safe to set *note tp_itemsize: 3878. to a different non-zero value in a subtype (though this depends on the implementation of the base type). -- C Member: destructor PyTypeObject.tp_dealloc A pointer to the instance destructor function. This function must be defined unless the type guarantees that its instances will never be deallocated (as is the case for the singletons ‘None’ and ‘Ellipsis’). The function signature is: void tp_dealloc(PyObject *self); The destructor function is called by the *note Py_DECREF(): 266. and *note Py_XDECREF(): 268. macros when the new reference count is zero. At this point, the instance is still in existence, but there are no references to it. The destructor function should free all references which the instance owns, free all memory buffers owned by the instance (using the freeing function corresponding to the allocation function used to allocate the buffer), and call the type’s *note tp_free: 3880. function. If the type is not subtypable (doesn’t have the *note Py_TPFLAGS_BASETYPE: 3887. flag bit set), it is permissible to call the object deallocator directly instead of via *note tp_free: 3880. The object deallocator should be the one used to allocate the instance; this is normally *note PyObject_Del(): e16. if the instance was allocated using *note PyObject_New(): 2d2. or ‘PyObject_VarNew()’, or *note PyObject_GC_Del(): e43. if the instance was allocated using *note PyObject_GC_New(): 2d4. or *note PyObject_GC_NewVar(): 2d5. Finally, if the type is heap allocated (*note Py_TPFLAGS_HEAPTYPE: 3abe.), the deallocator should decrement the reference count for its type object after calling the type deallocator. In order to avoid dangling pointers, the recommended way to achieve this is: static void foo_dealloc(foo_object *self) { PyTypeObject *tp = Py_TYPE(self); // free references and buffers here tp->tp_free(self); Py_DECREF(tp); } `Inheritance:' This field is inherited by subtypes. -- C Member: Py_ssize_t PyTypeObject.tp_vectorcall_offset An optional offset to a per-instance function that implements calling the object using the `vectorcall' protocol, a more efficient alternative of the simpler *note tp_call: 38ad. This field is only used if the flag *note _Py_TPFLAGS_HAVE_VECTORCALL: 3e22. is set. If so, this must be a positive integer containing the offset in the instance of a *note vectorcallfunc: 3e23. pointer. The signature is the same as for *note _PyObject_Vectorcall(): 3a10.: PyObject *vectorcallfunc(PyObject *callable, PyObject *const *args, size_t nargsf, PyObject *kwnames) The `vectorcallfunc' pointer may be zero, in which case the instance behaves as if *note _Py_TPFLAGS_HAVE_VECTORCALL: 3e22. was not set: calling the instance falls back to *note tp_call: 38ad. Any class that sets ‘_Py_TPFLAGS_HAVE_VECTORCALL’ must also set *note tp_call: 38ad. and make sure its behaviour is consistent with the `vectorcallfunc' function. This can be done by setting `tp_call' to ‘PyVectorcall_Call’: -- C Function: PyObject *PyVectorcall_Call (PyObject *callable, PyObject *tuple, PyObject *dict) Call `callable'’s `vectorcallfunc' with positional and keyword arguments given in a tuple and dict, respectively. This function is intended to be used in the ‘tp_call’ slot. It does not fall back to ‘tp_call’ and it currently does not check the ‘_Py_TPFLAGS_HAVE_VECTORCALL’ flag. To call an object, use one of the *note PyObject_Call: 3850. functions instead. Note: It is not recommended for *note heap types: 3abc. to implement the vectorcall protocol. When a user sets ‘__call__’ in Python code, only ‘tp_call’ is updated, possibly making it inconsistent with the vectorcall function. Note: The semantics of the ‘tp_vectorcall_offset’ slot are provisional and expected to be finalized in Python 3.9. If you use vectorcall, plan for updating your code for Python 3.9. Changed in version 3.8: This slot was used for print formatting in Python 2.x. In Python 3.0 to 3.7, it was reserved and named ‘tp_print’. `Inheritance:' This field is inherited by subtypes together with *note tp_call: 38ad.: a subtype inherits *note tp_vectorcall_offset: 3a11. from its base type when the subtype’s *note tp_call: 38ad. is ‘NULL’. Note that *note heap types: 3e25. (including subclasses defined in Python) do not inherit the *note _Py_TPFLAGS_HAVE_VECTORCALL: 3e22. flag. -- C Member: getattrfunc PyTypeObject.tp_getattr An optional pointer to the get-attribute-string function. This field is deprecated. When it is defined, it should point to a function that acts the same as the *note tp_getattro: 389f. function, but taking a C string instead of a Python string object to give the attribute name. `Inheritance:' Group: ‘tp_getattr’, ‘tp_getattro’ This field is inherited by subtypes together with *note tp_getattro: 389f.: a subtype inherits both *note tp_getattr: 38a2. and *note tp_getattro: 389f. from its base type when the subtype’s *note tp_getattr: 38a2. and *note tp_getattro: 389f. are both ‘NULL’. -- C Member: setattrfunc PyTypeObject.tp_setattr An optional pointer to the function for setting and deleting attributes. This field is deprecated. When it is defined, it should point to a function that acts the same as the *note tp_setattro: 38a0. function, but taking a C string instead of a Python string object to give the attribute name. `Inheritance:' Group: ‘tp_setattr’, ‘tp_setattro’ This field is inherited by subtypes together with *note tp_setattro: 38a0.: a subtype inherits both *note tp_setattr: 38a3. and *note tp_setattro: 38a0. from its base type when the subtype’s *note tp_setattr: 38a3. and *note tp_setattro: 38a0. are both ‘NULL’. -- C Member: PyAsyncMethods* PyTypeObject.tp_as_async Pointer to an additional structure that contains fields relevant only to objects which implement *note awaitable: 519. and *note asynchronous iterator: 645. protocols at the C-level. See *note Async Object Structures: 3e26. for details. New in version 3.5: Formerly known as ‘tp_compare’ and ‘tp_reserved’. `Inheritance:' The *note tp_as_async: 3dba. field is not inherited, but the contained fields are inherited individually. -- C Member: reprfunc PyTypeObject.tp_repr An optional pointer to a function that implements the built-in function *note repr(): 7cc. The signature is the same as for *note PyObject_Repr(): 968.: PyObject *tp_repr(PyObject *self); The function must return a string or a Unicode object. Ideally, this function should return a string that, when passed to *note eval(): b90, given a suitable environment, returns an object with the same value. If this is not feasible, it should return a string starting with ‘'<'’ and ending with ‘'>'’ from which both the type and the value of the object can be deduced. `Inheritance:' This field is inherited by subtypes. `Default:' When this field is not set, a string of the form ‘<%s object at %p>’ is returned, where ‘%s’ is replaced by the type name, and ‘%p’ by the object’s memory address. -- C Member: PyNumberMethods* PyTypeObject.tp_as_number Pointer to an additional structure that contains fields relevant only to objects which implement the number protocol. These fields are documented in *note Number Object Structures: 3e27. `Inheritance:' The *note tp_as_number: 3dbd. field is not inherited, but the contained fields are inherited individually. -- C Member: PySequenceMethods* PyTypeObject.tp_as_sequence Pointer to an additional structure that contains fields relevant only to objects which implement the sequence protocol. These fields are documented in *note Sequence Object Structures: 3e28. `Inheritance:' The *note tp_as_sequence: 3dbe. field is not inherited, but the contained fields are inherited individually. -- C Member: PyMappingMethods* PyTypeObject.tp_as_mapping Pointer to an additional structure that contains fields relevant only to objects which implement the mapping protocol. These fields are documented in *note Mapping Object Structures: 3e29. `Inheritance:' The *note tp_as_mapping: 3dbf. field is not inherited, but the contained fields are inherited individually. -- C Member: hashfunc PyTypeObject.tp_hash An optional pointer to a function that implements the built-in function *note hash(): 9c4. The signature is the same as for *note PyObject_Hash(): 3a15.: Py_hash_t tp_hash(PyObject *); The value ‘-1’ should not be returned as a normal return value; when an error occurs during the computation of the hash value, the function should set an exception and return ‘-1’. When this field is not set (`and' ‘tp_richcompare’ is not set), an attempt to take the hash of the object raises *note TypeError: 192. This is the same as setting it to *note PyObject_HashNotImplemented(): d31. This field can be set explicitly to *note PyObject_HashNotImplemented(): d31. to block inheritance of the hash method from a parent type. This is interpreted as the equivalent of ‘__hash__ = None’ at the Python level, causing ‘isinstance(o, collections.Hashable)’ to correctly return ‘False’. Note that the converse is also true - setting ‘__hash__ = None’ on a class at the Python level will result in the ‘tp_hash’ slot being set to *note PyObject_HashNotImplemented(): d31. `Inheritance:' Group: ‘tp_hash’, ‘tp_richcompare’ This field is inherited by subtypes together with *note tp_richcompare: 38a5.: a subtype inherits both of *note tp_richcompare: 38a5. and *note tp_hash: 38ac, when the subtype’s *note tp_richcompare: 38a5. and *note tp_hash: 38ac. are both ‘NULL’. -- C Member: ternaryfunc PyTypeObject.tp_call An optional pointer to a function that implements calling the object. This should be ‘NULL’ if the object is not callable. The signature is the same as for *note PyObject_Call(): 3850.: PyObject *tp_call(PyObject *self, PyObject *args, PyObject *kwargs); `Inheritance:' This field is inherited by subtypes. -- C Member: reprfunc PyTypeObject.tp_str An optional pointer to a function that implements the built-in operation *note str(): 330. (Note that *note str: 330. is a type now, and *note str(): 330. calls the constructor for that type. This constructor calls *note PyObject_Str(): 969. to do the actual work, and *note PyObject_Str(): 969. will call this handler.) The signature is the same as for *note PyObject_Str(): 969.: PyObject *tp_str(PyObject *self); The function must return a string or a Unicode object. It should be a “friendly” string representation of the object, as this is the representation that will be used, among other things, by the *note print(): 886. function. `Inheritance:' This field is inherited by subtypes. `Default:' When this field is not set, *note PyObject_Repr(): 968. is called to return a string representation. -- C Member: getattrofunc PyTypeObject.tp_getattro An optional pointer to the get-attribute function. The signature is the same as for *note PyObject_GetAttr(): 3a00.: PyObject *tp_getattro(PyObject *self, PyObject *attr); It is usually convenient to set this field to *note PyObject_GenericGetAttr(): 3a02, which implements the normal way of looking for object attributes. `Inheritance:' Group: ‘tp_getattr’, ‘tp_getattro’ This field is inherited by subtypes together with *note tp_getattr: 38a2.: a subtype inherits both *note tp_getattr: 38a2. and *note tp_getattro: 389f. from its base type when the subtype’s *note tp_getattr: 38a2. and *note tp_getattro: 389f. are both ‘NULL’. `Default:' ‘PyBaseObject_Type’ uses *note PyObject_GenericGetAttr(): 3a02. -- C Member: setattrofunc PyTypeObject.tp_setattro An optional pointer to the function for setting and deleting attributes. The signature is the same as for *note PyObject_SetAttr(): 3a03.: PyObject *tp_setattro(PyObject *self, PyObject *attr, PyObject *value); In addition, setting `value' to ‘NULL’ to delete an attribute must be supported. It is usually convenient to set this field to *note PyObject_GenericSetAttr(): 3a07, which implements the normal way of setting object attributes. `Inheritance:' Group: ‘tp_setattr’, ‘tp_setattro’ This field is inherited by subtypes together with *note tp_setattr: 38a3.: a subtype inherits both *note tp_setattr: 38a3. and *note tp_setattro: 38a0. from its base type when the subtype’s *note tp_setattr: 38a3. and *note tp_setattro: 38a0. are both ‘NULL’. `Default:' ‘PyBaseObject_Type’ uses *note PyObject_GenericSetAttr(): 3a07. -- C Member: PyBufferProcs* PyTypeObject.tp_as_buffer Pointer to an additional structure that contains fields relevant only to objects which implement the buffer interface. These fields are documented in *note Buffer Object Structures: 3a6e. `Inheritance:' The *note tp_as_buffer: 3dc4. field is not inherited, but the contained fields are inherited individually. -- C Member: unsigned long PyTypeObject.tp_flags This field is a bit mask of various flags. Some flags indicate variant semantics for certain situations; others are used to indicate that certain fields in the type object (or in the extension structures referenced via *note tp_as_number: 3dbd, *note tp_as_sequence: 3dbe, *note tp_as_mapping: 3dbf, and *note tp_as_buffer: 3dc4.) that were historically not always present are valid; if such a flag bit is clear, the type fields it guards must not be accessed and must be considered to have a zero or ‘NULL’ value instead. `Inheritance:' Inheritance of this field is complicated. Most flag bits are inherited individually, i.e. if the base type has a flag bit set, the subtype inherits this flag bit. The flag bits that pertain to extension structures are strictly inherited if the extension structure is inherited, i.e. the base type’s value of the flag bit is copied into the subtype together with a pointer to the extension structure. The *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is inherited together with the *note tp_traverse: 33e8. and *note tp_clear: 3898. fields, i.e. if the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is clear in the subtype and the *note tp_traverse: 33e8. and *note tp_clear: 3898. fields in the subtype exist and have ‘NULL’ values. `Default:' ‘PyBaseObject_Type’ uses ‘Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE’. `Bit Masks:' The following bit masks are currently defined; these can be ORed together using the ‘|’ operator to form the value of the *note tp_flags: 3ab6. field. The macro *note PyType_HasFeature(): 3ab8. takes a type and a flags value, `tp' and `f', and checks whether ‘tp->tp_flags & f’ is non-zero. -- Data: Py_TPFLAGS_HEAPTYPE This bit is set when the type object itself is allocated on the heap, for example, types created dynamically using *note PyType_FromSpec(): 2d1. In this case, the ‘ob_type’ field of its instances is considered a reference to the type, and the type object is INCREF’ed when a new instance is created, and DECREF’ed when an instance is destroyed (this does not apply to instances of subtypes; only the type referenced by the instance’s ob_type gets INCREF’ed or DECREF’ed). `Inheritance:' ??? -- Data: Py_TPFLAGS_BASETYPE This bit is set when the type can be used as the base type of another type. If this bit is clear, the type cannot be subtyped (similar to a “final” class in Java). `Inheritance:' ??? -- Data: Py_TPFLAGS_READY This bit is set when the type object has been fully initialized by *note PyType_Ready(): 3882. `Inheritance:' ??? -- Data: Py_TPFLAGS_READYING This bit is set while *note PyType_Ready(): 3882. is in the process of initializing the type object. `Inheritance:' ??? -- Data: Py_TPFLAGS_HAVE_GC This bit is set when the object supports garbage collection. If this bit is set, instances must be created using *note PyObject_GC_New(): 2d4. and destroyed using *note PyObject_GC_Del(): e43. More information in section *note Supporting Cyclic Garbage Collection: 3e2c. This bit also implies that the GC-related fields *note tp_traverse: 33e8. and *note tp_clear: 3898. are present in the type object. `Inheritance:' Group: *note Py_TPFLAGS_HAVE_GC: 388e, ‘tp_traverse’, ‘tp_clear’ The *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is inherited together with the ‘tp_traverse’ and ‘tp_clear’ fields, i.e. if the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is clear in the subtype and the ‘tp_traverse’ and ‘tp_clear’ fields in the subtype exist and have ‘NULL’ values. -- Data: Py_TPFLAGS_DEFAULT This is a bitmask of all the bits that pertain to the existence of certain fields in the type object and its extension structures. Currently, it includes the following bits: ‘Py_TPFLAGS_HAVE_STACKLESS_EXTENSION’, ‘Py_TPFLAGS_HAVE_VERSION_TAG’. `Inheritance:' ??? -- Data: Py_TPFLAGS_METHOD_DESCRIPTOR This bit indicates that objects behave like unbound methods. If this flag is set for ‘type(meth)’, then: - ‘meth.__get__(obj, cls)(*args, **kwds)’ (with ‘obj’ not None) must be equivalent to ‘meth(obj, *args, **kwds)’. - ‘meth.__get__(None, cls)(*args, **kwds)’ must be equivalent to ‘meth(*args, **kwds)’. This flag enables an optimization for typical method calls like ‘obj.meth()’: it avoids creating a temporary “bound method” object for ‘obj.meth’. New in version 3.8. `Inheritance:' This flag is never inherited by heap types. For extension types, it is inherited whenever *note tp_descr_get: 3dcb. is inherited. -- Data: Py_TPFLAGS_LONG_SUBCLASS -- Data: Py_TPFLAGS_LIST_SUBCLASS -- Data: Py_TPFLAGS_TUPLE_SUBCLASS -- Data: Py_TPFLAGS_BYTES_SUBCLASS -- Data: Py_TPFLAGS_UNICODE_SUBCLASS -- Data: Py_TPFLAGS_DICT_SUBCLASS -- Data: Py_TPFLAGS_BASE_EXC_SUBCLASS -- Data: Py_TPFLAGS_TYPE_SUBCLASS These flags are used by functions such as *note PyLong_Check(): 3adc. to quickly determine if a type is a subclass of a built-in type; such specific checks are faster than a generic check, like *note PyObject_IsInstance(): 79d. Custom types that inherit from built-ins should have their *note tp_flags: 3ab6. set appropriately, or the code that interacts with such types will behave differently depending on what kind of check is used. -- Data: Py_TPFLAGS_HAVE_FINALIZE This bit is set when the *note tp_finalize: 2d7. slot is present in the type structure. New in version 3.4. Deprecated since version 3.8: This flag isn’t necessary anymore, as the interpreter assumes the *note tp_finalize: 2d7. slot is always present in the type structure. -- Data: _Py_TPFLAGS_HAVE_VECTORCALL This bit is set when the class implements the vectorcall protocol. See *note tp_vectorcall_offset: 3a11. for details. `Inheritance:' This bit is set on `static' subtypes if ‘tp_flags’ is not overridden: a subtype inherits ‘_Py_TPFLAGS_HAVE_VECTORCALL’ from its base type when the subtype’s *note tp_call: 38ad. is ‘NULL’ and the subtype’s ‘Py_TPFLAGS_HEAPTYPE’ is not set. *note Heap types: 3e25. do not inherit ‘_Py_TPFLAGS_HAVE_VECTORCALL’. Note: This flag is provisional and expected to become public in Python 3.9, with a different name and, possibly, changed semantics. If you use vectorcall, plan for updating your code for Python 3.9. New in version 3.8. -- C Member: const char* PyTypeObject.tp_doc An optional pointer to a NUL-terminated C string giving the docstring for this type object. This is exposed as the ‘__doc__’ attribute on the type and instances of the type. `Inheritance:' This field is `not' inherited by subtypes. -- C Member: traverseproc PyTypeObject.tp_traverse An optional pointer to a traversal function for the garbage collector. This is only used if the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is set. The signature is: int tp_traverse(PyObject *self, visitproc visit, void *arg); More information about Python’s garbage collection scheme can be found in section *note Supporting Cyclic Garbage Collection: 3e2c. The *note tp_traverse: 33e8. pointer is used by the garbage collector to detect reference cycles. A typical implementation of a *note tp_traverse: 33e8. function simply calls *note Py_VISIT(): 388c. on each of the instance’s members that are Python objects that the instance owns. For example, this is function ‘local_traverse()’ from the *note _thread: 3. extension module: static int local_traverse(localobject *self, visitproc visit, void *arg) { Py_VISIT(self->args); Py_VISIT(self->kw); Py_VISIT(self->dict); return 0; } Note that *note Py_VISIT(): 388c. is called only on those members that can participate in reference cycles. Although there is also a ‘self->key’ member, it can only be ‘NULL’ or a Python string and therefore cannot be part of a reference cycle. On the other hand, even if you know a member can never be part of a cycle, as a debugging aid you may want to visit it anyway just so the *note gc: 86. module’s *note get_referents(): 31f4. function will include it. Warning: When implementing *note tp_traverse: 33e8, only the members that the instance `owns' (by having strong references to them) must be visited. For instance, if an object supports weak references via the *note tp_weaklist: 3ace. slot, the pointer supporting the linked list (what `tp_weaklist' points to) must `not' be visited as the instance does not directly own the weak references to itself (the weakreference list is there to support the weak reference machinery, but the instance has no strong reference to the elements inside it, as they are allowed to be removed even if the instance is still alive). Note that *note Py_VISIT(): 388c. requires the `visit' and `arg' parameters to ‘local_traverse()’ to have these specific names; don’t name them just anything. `Inheritance:' Group: *note Py_TPFLAGS_HAVE_GC: 388e, ‘tp_traverse’, ‘tp_clear’ This field is inherited by subtypes together with *note tp_clear: 3898. and the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit: the flag bit, *note tp_traverse: 33e8, and *note tp_clear: 3898. are all inherited from the base type if they are all zero in the subtype. -- C Member: inquiry PyTypeObject.tp_clear An optional pointer to a clear function for the garbage collector. This is only used if the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit is set. The signature is: int tp_clear(PyObject *); The *note tp_clear: 3898. member function is used to break reference cycles in cyclic garbage detected by the garbage collector. Taken together, all *note tp_clear: 3898. functions in the system must combine to break all reference cycles. This is subtle, and if in any doubt supply a *note tp_clear: 3898. function. For example, the tuple type does not implement a *note tp_clear: 3898. function, because it’s possible to prove that no reference cycle can be composed entirely of tuples. Therefore the *note tp_clear: 3898. functions of other types must be sufficient to break any cycle containing a tuple. This isn’t immediately obvious, and there’s rarely a good reason to avoid implementing *note tp_clear: 3898. Implementations of *note tp_clear: 3898. should drop the instance’s references to those of its members that may be Python objects, and set its pointers to those members to ‘NULL’, as in the following example: static int local_clear(localobject *self) { Py_CLEAR(self->key); Py_CLEAR(self->args); Py_CLEAR(self->kw); Py_CLEAR(self->dict); return 0; } The *note Py_CLEAR(): 388d. macro should be used, because clearing references is delicate: the reference to the contained object must not be decremented until after the pointer to the contained object is set to ‘NULL’. This is because decrementing the reference count may cause the contained object to become trash, triggering a chain of reclamation activity that may include invoking arbitrary Python code (due to finalizers, or weakref callbacks, associated with the contained object). If it’s possible for such code to reference `self' again, it’s important that the pointer to the contained object be ‘NULL’ at that time, so that `self' knows the contained object can no longer be used. The *note Py_CLEAR(): 388d. macro performs the operations in a safe order. Because the goal of *note tp_clear: 3898. functions is to break reference cycles, it’s not necessary to clear contained objects like Python strings or Python integers, which can’t participate in reference cycles. On the other hand, it may be convenient to clear all contained Python objects, and write the type’s *note tp_dealloc: 387f. function to invoke *note tp_clear: 3898. More information about Python’s garbage collection scheme can be found in section *note Supporting Cyclic Garbage Collection: 3e2c. `Inheritance:' Group: *note Py_TPFLAGS_HAVE_GC: 388e, ‘tp_traverse’, ‘tp_clear’ This field is inherited by subtypes together with *note tp_traverse: 33e8. and the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit: the flag bit, *note tp_traverse: 33e8, and *note tp_clear: 3898. are all inherited from the base type if they are all zero in the subtype. -- C Member: richcmpfunc PyTypeObject.tp_richcompare An optional pointer to the rich comparison function, whose signature is: PyObject *tp_richcompare(PyObject *self, PyObject *other, int op); The first parameter is guaranteed to be an instance of the type that is defined by *note PyTypeObject: 2d6. The function should return the result of the comparison (usually ‘Py_True’ or ‘Py_False’). If the comparison is undefined, it must return ‘Py_NotImplemented’, if another error occurred it must return ‘NULL’ and set an exception condition. The following constants are defined to be used as the third argument for *note tp_richcompare: 38a5. and for *note PyObject_RichCompare(): 38a6.: Constant Comparison -------------------------------------- ‘Py_LT’ ‘<’ ‘Py_LE’ ‘<=’ ‘Py_EQ’ ‘==’ ‘Py_NE’ ‘!=’ ‘Py_GT’ ‘>’ ‘Py_GE’ ‘>=’ The following macro is defined to ease writing rich comparison functions: -- C Macro: Py_RETURN_RICHCOMPARE (VAL_A, VAL_B, op) Return ‘Py_True’ or ‘Py_False’ from the function, depending on the result of a comparison. VAL_A and VAL_B must be orderable by C comparison operators (for example, they may be C ints or floats). The third argument specifies the requested operation, as for *note PyObject_RichCompare(): 38a6. The return value’s reference count is properly incremented. On error, sets an exception and returns ‘NULL’ from the function. New in version 3.7. `Inheritance:' Group: ‘tp_hash’, ‘tp_richcompare’ This field is inherited by subtypes together with *note tp_hash: 38ac.: a subtype inherits *note tp_richcompare: 38a5. and *note tp_hash: 38ac. when the subtype’s *note tp_richcompare: 38a5. and *note tp_hash: 38ac. are both ‘NULL’. `Default:' ‘PyBaseObject_Type’ provides a ‘tp_richcompare’ implementation, which may be inherited. However, if only ‘tp_hash’ is defined, not even the inherited function is used and instances of the type will not be able to participate in any comparisons. -- C Member: Py_ssize_t PyTypeObject.tp_weaklistoffset If the instances of this type are weakly referenceable, this field is greater than zero and contains the offset in the instance structure of the weak reference list head (ignoring the GC header, if present); this offset is used by ‘PyObject_ClearWeakRefs()’ and the ‘PyWeakref_*()’ functions. The instance structure needs to include a field of type *note PyObject*: 4ba. which is initialized to ‘NULL’. Do not confuse this field with *note tp_weaklist: 3ace.; that is the list head for weak references to the type object itself. `Inheritance:' This field is inherited by subtypes, but see the rules listed below. A subtype may override this offset; this means that the subtype uses a different weak reference list head than the base type. Since the list head is always found via *note tp_weaklistoffset: 38af, this should not be a problem. When a type defined by a class statement has no *note __slots__: e2d. declaration, and none of its base types are weakly referenceable, the type is made weakly referenceable by adding a weak reference list head slot to the instance layout and setting the *note tp_weaklistoffset: 38af. of that slot’s offset. When a type’s *note __slots__: e2d. declaration contains a slot named ‘__weakref__’, that slot becomes the weak reference list head for instances of the type, and the slot’s offset is stored in the type’s *note tp_weaklistoffset: 38af. When a type’s *note __slots__: e2d. declaration does not contain a slot named ‘__weakref__’, the type inherits its *note tp_weaklistoffset: 38af. from its base type. -- C Member: getiterfunc PyTypeObject.tp_iter An optional pointer to a function that returns an iterator for the object. Its presence normally signals that the instances of this type are iterable (although sequences may be iterable without this function). This function has the same signature as *note PyObject_GetIter(): 3a1d.: PyObject *tp_iter(PyObject *self); `Inheritance:' This field is inherited by subtypes. -- C Member: iternextfunc PyTypeObject.tp_iternext An optional pointer to a function that returns the next item in an iterator. The signature is: PyObject *tp_iternext(PyObject *self); When the iterator is exhausted, it must return ‘NULL’; a *note StopIteration: 486. exception may or may not be set. When another error occurs, it must return ‘NULL’ too. Its presence signals that the instances of this type are iterators. Iterator types should also define the *note tp_iter: e30. function, and that function should return the iterator instance itself (not a new iterator instance). This function has the same signature as *note PyIter_Next(): 3a6b. `Inheritance:' This field is inherited by subtypes. -- C Member: struct PyMethodDef* PyTypeObject.tp_methods An optional pointer to a static ‘NULL’-terminated array of *note PyMethodDef: e1b. structures, declaring regular methods of this type. For each entry in the array, an entry is added to the type’s dictionary (see *note tp_dict: 3aca. below) containing a method descriptor. `Inheritance:' This field is not inherited by subtypes (methods are inherited through a different mechanism). -- C Member: struct PyMemberDef* PyTypeObject.tp_members An optional pointer to a static ‘NULL’-terminated array of *note PyMemberDef: 426. structures, declaring regular data members (fields or slots) of instances of this type. For each entry in the array, an entry is added to the type’s dictionary (see *note tp_dict: 3aca. below) containing a member descriptor. `Inheritance:' This field is not inherited by subtypes (members are inherited through a different mechanism). -- C Member: struct PyGetSetDef* PyTypeObject.tp_getset An optional pointer to a static ‘NULL’-terminated array of *note PyGetSetDef: 427. structures, declaring computed attributes of instances of this type. For each entry in the array, an entry is added to the type’s dictionary (see *note tp_dict: 3aca. below) containing a getset descriptor. `Inheritance:' This field is not inherited by subtypes (computed attributes are inherited through a different mechanism). -- C Member: PyTypeObject* PyTypeObject.tp_base An optional pointer to a base type from which type properties are inherited. At this level, only single inheritance is supported; multiple inheritance require dynamically creating a type object by calling the metatype. Note: Slot initialization is subject to the rules of initializing globals. C99 requires the initializers to be “address constants”. Function designators like *note PyType_GenericNew(): 387d, with implicit conversion to a pointer, are valid C99 address constants. However, the unary ‘&’ operator applied to a non-static variable like ‘PyBaseObject_Type()’ is not required to produce an address constant. Compilers may support this (gcc does), MSVC does not. Both compilers are strictly standard conforming in this particular behavior. Consequently, *note tp_base: 3890. should be set in the extension module’s init function. `Inheritance:' This field is not inherited by subtypes (obviously). `Default:' This field defaults to ‘&PyBaseObject_Type’ (which to Python programmers is known as the type *note object: 2b0.). -- C Member: PyObject* PyTypeObject.tp_dict The type’s dictionary is stored here by *note PyType_Ready(): 3882. This field should normally be initialized to ‘NULL’ before PyType_Ready is called; it may also be initialized to a dictionary containing initial attributes for the type. Once *note PyType_Ready(): 3882. has initialized the type, extra attributes for the type may be added to this dictionary only if they don’t correspond to overloaded operations (like *note __add__(): 10f9.). `Inheritance:' This field is not inherited by subtypes (though the attributes defined in here are inherited through a different mechanism). `Default:' If this field is ‘NULL’, *note PyType_Ready(): 3882. will assign a new dictionary to it. Warning: It is not safe to use *note PyDict_SetItem(): 3863. on or otherwise modify *note tp_dict: 3aca. with the dictionary C-API. -- C Member: descrgetfunc PyTypeObject.tp_descr_get An optional pointer to a “descriptor get” function. The function signature is: PyObject * tp_descr_get(PyObject *self, PyObject *obj, PyObject *type); `Inheritance:' This field is inherited by subtypes. -- C Member: descrsetfunc PyTypeObject.tp_descr_set An optional pointer to a function for setting and deleting a descriptor’s value. The function signature is: int tp_descr_set(PyObject *self, PyObject *obj, PyObject *value); The `value' argument is set to ‘NULL’ to delete the value. `Inheritance:' This field is inherited by subtypes. -- C Member: Py_ssize_t PyTypeObject.tp_dictoffset If the instances of this type have a dictionary containing instance variables, this field is non-zero and contains the offset in the instances of the type of the instance variable dictionary; this offset is used by *note PyObject_GenericGetAttr(): 3a02. Do not confuse this field with *note tp_dict: 3aca.; that is the dictionary for attributes of the type object itself. If the value of this field is greater than zero, it specifies the offset from the start of the instance structure. If the value is less than zero, it specifies the offset from the `end' of the instance structure. A negative offset is more expensive to use, and should only be used when the instance structure contains a variable-length part. This is used for example to add an instance variable dictionary to subtypes of *note str: 330. or *note tuple: 47e. Note that the *note tp_basicsize: 3879. field should account for the dictionary added to the end in that case, even though the dictionary is not included in the basic object layout. On a system with a pointer size of 4 bytes, *note tp_dictoffset: 3acf. should be set to ‘-4’ to indicate that the dictionary is at the very end of the structure. The real dictionary offset in an instance can be computed from a negative *note tp_dictoffset: 3acf. as follows: dictoffset = tp_basicsize + abs(ob_size)*tp_itemsize + tp_dictoffset if dictoffset is not aligned on sizeof(void*): round up to sizeof(void*) where *note tp_basicsize: 3879, *note tp_itemsize: 3878. and *note tp_dictoffset: 3acf. are taken from the type object, and ‘ob_size’ is taken from the instance. The absolute value is taken because ints use the sign of ‘ob_size’ to store the sign of the number. (There’s never a need to do this calculation yourself; it is done for you by ‘_PyObject_GetDictPtr()’.) `Inheritance:' This field is inherited by subtypes, but see the rules listed below. A subtype may override this offset; this means that the subtype instances store the dictionary at a difference offset than the base type. Since the dictionary is always found via *note tp_dictoffset: 3acf, this should not be a problem. When a type defined by a class statement has no *note __slots__: e2d. declaration, and none of its base types has an instance variable dictionary, a dictionary slot is added to the instance layout and the *note tp_dictoffset: 3acf. is set to that slot’s offset. When a type defined by a class statement has a *note __slots__: e2d. declaration, the type inherits its *note tp_dictoffset: 3acf. from its base type. (Adding a slot named *note __dict__: 4fc. to the *note __slots__: e2d. declaration does not have the expected effect, it just causes confusion. Maybe this should be added as a feature just like ‘__weakref__’ though.) `Default:' This slot has no default. For static types, if the field is ‘NULL’ then no *note __dict__: 4fc. gets created for instances. -- C Member: initproc PyTypeObject.tp_init An optional pointer to an instance initialization function. This function corresponds to the *note __init__(): d5e. method of classes. Like *note __init__(): d5e, it is possible to create an instance without calling *note __init__(): d5e, and it is possible to reinitialize an instance by calling its *note __init__(): d5e. method again. The function signature is: int tp_init(PyObject *self, PyObject *args, PyObject *kwds); The self argument is the instance to be initialized; the `args' and `kwds' arguments represent positional and keyword arguments of the call to *note __init__(): d5e. The *note tp_init: 3883. function, if not ‘NULL’, is called when an instance is created normally by calling its type, after the type’s *note tp_new: 387c. function has returned an instance of the type. If the *note tp_new: 387c. function returns an instance of some other type that is not a subtype of the original type, no *note tp_init: 3883. function is called; if *note tp_new: 387c. returns an instance of a subtype of the original type, the subtype’s *note tp_init: 3883. is called. Returns ‘0’ on success, ‘-1’ and sets an exception on error. `Inheritance:' This field is inherited by subtypes. `Default:' For static types this field does not have a default. -- C Member: allocfunc PyTypeObject.tp_alloc An optional pointer to an instance allocation function. The function signature is: PyObject *tp_alloc(PyTypeObject *self, Py_ssize_t nitems); `Inheritance:' This field is inherited by static subtypes, but not by dynamic subtypes (subtypes created by a class statement). `Default:' For dynamic subtypes, this field is always set to *note PyType_GenericAlloc(): 270, to force a standard heap allocation strategy. For static subtypes, ‘PyBaseObject_Type’ uses *note PyType_GenericAlloc(): 270. That is the recommended value for all statically defined types. -- C Member: newfunc PyTypeObject.tp_new An optional pointer to an instance creation function. The function signature is: PyObject *tp_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds); The subtype argument is the type of the object being created; the `args' and `kwds' arguments represent positional and keyword arguments of the call to the type. Note that subtype doesn’t have to equal the type whose *note tp_new: 387c. function is called; it may be a subtype of that type (but not an unrelated type). The *note tp_new: 387c. function should call ‘subtype->tp_alloc(subtype, nitems)’ to allocate space for the object, and then do only as much further initialization as is absolutely necessary. Initialization that can safely be ignored or repeated should be placed in the *note tp_init: 3883. handler. A good rule of thumb is that for immutable types, all initialization should take place in *note tp_new: 387c, while for mutable types, most initialization should be deferred to *note tp_init: 3883. `Inheritance:' This field is inherited by subtypes, except it is not inherited by static types whose *note tp_base: 3890. is ‘NULL’ or ‘&PyBaseObject_Type’. `Default:' For static types this field has no default. This means if the slot is defined as ‘NULL’, the type cannot be called to create new instances; presumably there is some other way to create instances, like a factory function. -- C Member: freefunc PyTypeObject.tp_free An optional pointer to an instance deallocation function. Its signature is: void tp_free(void *self); An initializer that is compatible with this signature is *note PyObject_Free(): 504. `Inheritance:' This field is inherited by static subtypes, but not by dynamic subtypes (subtypes created by a class statement) `Default:' In dynamic subtypes, this field is set to a deallocator suitable to match *note PyType_GenericAlloc(): 270. and the value of the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit. For static subtypes, ‘PyBaseObject_Type’ uses PyObject_Del. -- C Member: inquiry PyTypeObject.tp_is_gc An optional pointer to a function called by the garbage collector. The garbage collector needs to know whether a particular object is collectible or not. Normally, it is sufficient to look at the object’s type’s *note tp_flags: 3ab6. field, and check the *note Py_TPFLAGS_HAVE_GC: 388e. flag bit. But some types have a mixture of statically and dynamically allocated instances, and the statically allocated instances are not collectible. Such types should define this function; it should return ‘1’ for a collectible instance, and ‘0’ for a non-collectible instance. The signature is: int tp_is_gc(PyObject *self); (The only example of this are types themselves. The metatype, *note PyType_Type: 3ab1, defines this function to distinguish between statically and dynamically allocated types.) `Inheritance:' This field is inherited by subtypes. `Default:' This slot has no default. If this field is ‘NULL’, *note Py_TPFLAGS_HAVE_GC: 388e. is used as the functional equivalent. -- C Member: PyObject* PyTypeObject.tp_bases Tuple of base types. This is set for types created by a class statement. It should be ‘NULL’ for statically defined types. `Inheritance:' This field is not inherited. -- C Member: PyObject* PyTypeObject.tp_mro Tuple containing the expanded set of base types, starting with the type itself and ending with *note object: 2b0, in Method Resolution Order. `Inheritance:' This field is not inherited; it is calculated fresh by *note PyType_Ready(): 3882. -- C Member: PyObject* PyTypeObject.tp_cache Unused. Internal use only. `Inheritance:' This field is not inherited. -- C Member: PyObject* PyTypeObject.tp_subclasses List of weak references to subclasses. Internal use only. `Inheritance:' This field is not inherited. -- C Member: PyObject* PyTypeObject.tp_weaklist Weak reference list head, for weak references to this type object. Not inherited. Internal use only. `Inheritance:' This field is not inherited. -- C Member: destructor PyTypeObject.tp_del This field is deprecated. Use *note tp_finalize: 2d7. instead. -- C Member: unsigned int PyTypeObject.tp_version_tag Used to index into the method cache. Internal use only. `Inheritance:' This field is not inherited. -- C Member: destructor PyTypeObject.tp_finalize An optional pointer to an instance finalization function. Its signature is: void tp_finalize(PyObject *self); If *note tp_finalize: 2d7. is set, the interpreter calls it once when finalizing an instance. It is called either from the garbage collector (if the instance is part of an isolated reference cycle) or just before the object is deallocated. Either way, it is guaranteed to be called before attempting to break reference cycles, ensuring that it finds the object in a sane state. *note tp_finalize: 2d7. should not mutate the current exception status; therefore, a recommended way to write a non-trivial finalizer is: static void local_finalize(PyObject *self) { PyObject *error_type, *error_value, *error_traceback; /* Save the current exception, if any. */ PyErr_Fetch(&error_type, &error_value, &error_traceback); /* ... */ /* Restore the saved exception. */ PyErr_Restore(error_type, error_value, error_traceback); } For this field to be taken into account (even through inheritance), you must also set the *note Py_TPFLAGS_HAVE_FINALIZE: 2d8. flags bit. `Inheritance:' This field is inherited by subtypes. New in version 3.4. See also ........ “Safe object finalization” ( PEP 442(1)) The remaining fields are only defined if the feature test macro ‘COUNT_ALLOCS’ is defined, and are for internal use only. They are documented here for completeness. None of these fields are inherited by subtypes. -- C Member: Py_ssize_t PyTypeObject.tp_allocs Number of allocations. -- C Member: Py_ssize_t PyTypeObject.tp_frees Number of frees. -- C Member: Py_ssize_t PyTypeObject.tp_maxalloc Maximum simultaneously allocated objects. -- C Member: PyTypeObject* PyTypeObject.tp_prev Pointer to the previous type object with a non-zero *note tp_allocs: 3dd7. field. -- C Member: PyTypeObject* PyTypeObject.tp_next Pointer to the next type object with a non-zero *note tp_allocs: 3dd7. field. Also, note that, in a garbage collected Python, *note tp_dealloc: 387f. may be called from any Python thread, not just the thread which created the object (if the object becomes part of a refcount cycle, that cycle might be collected by a garbage collection on any thread). This is not a problem for Python API calls, since the thread on which tp_dealloc is called will own the Global Interpreter Lock (GIL). However, if the object being destroyed in turn destroys objects from some other C or C++ library, care should be taken to ensure that destroying those objects on the thread which called tp_dealloc will not violate any assumptions of the library. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0442  File: python.info, Node: Heap Types, Prev: PyTypeObject Slots, Up: Type Objects<3> 7.12.3.9 Heap Types ................... Traditionally, types defined in C code are `static', that is, a static *note PyTypeObject: 2d6. structure is defined directly in code and initialized using *note PyType_Ready(): 3882. This results in types that are limited relative to types defined in Python: * Static types are limited to one base, i.e. they cannot use multiple inheritance. * Static type objects (but not necessarily their instances) are immutable. It is not possible to add or modify the type object’s attributes from Python. * Static type objects are shared across *note sub-interpreters: 398b, so they should not include any subinterpreter-specific state. Also, since *note PyTypeObject: 2d6. is not part of the *note stable ABI: 3905, any extension modules using static types must be compiled for a specific Python minor version. An alternative to static types is `heap-allocated types', or `heap types' for short, which correspond closely to classes created by Python’s ‘class’ statement. This is done by filling a *note PyType_Spec: 3abf. structure and calling *note PyType_FromSpecWithBases(): 3abd.  File: python.info, Node: Number Object Structures, Next: Mapping Object Structures, Prev: Type Objects<3>, Up: Object Implementation Support 7.12.4 Number Object Structures ------------------------------- -- C Type: PyNumberMethods This structure holds pointers to the functions which an object uses to implement the number protocol. Each function is used by the function of similar name documented in the *note Number Protocol: 3a1f. section. Here is the structure definition: typedef struct { binaryfunc nb_add; binaryfunc nb_subtract; binaryfunc nb_multiply; binaryfunc nb_remainder; binaryfunc nb_divmod; ternaryfunc nb_power; unaryfunc nb_negative; unaryfunc nb_positive; unaryfunc nb_absolute; inquiry nb_bool; unaryfunc nb_invert; binaryfunc nb_lshift; binaryfunc nb_rshift; binaryfunc nb_and; binaryfunc nb_xor; binaryfunc nb_or; unaryfunc nb_int; void *nb_reserved; unaryfunc nb_float; binaryfunc nb_inplace_add; binaryfunc nb_inplace_subtract; binaryfunc nb_inplace_multiply; binaryfunc nb_inplace_remainder; ternaryfunc nb_inplace_power; binaryfunc nb_inplace_lshift; binaryfunc nb_inplace_rshift; binaryfunc nb_inplace_and; binaryfunc nb_inplace_xor; binaryfunc nb_inplace_or; binaryfunc nb_floor_divide; binaryfunc nb_true_divide; binaryfunc nb_inplace_floor_divide; binaryfunc nb_inplace_true_divide; unaryfunc nb_index; binaryfunc nb_matrix_multiply; binaryfunc nb_inplace_matrix_multiply; } PyNumberMethods; Note: Binary and ternary functions must check the type of all their operands, and implement the necessary conversions (at least one of the operands is an instance of the defined type). If the operation is not defined for the given operands, binary and ternary functions must return ‘Py_NotImplemented’, if another error occurred they must return ‘NULL’ and set an exception. Note: The ‘nb_reserved’ field should always be ‘NULL’. It was previously called ‘nb_long’, and was renamed in Python 3.0.1. -- C Member: binaryfunc PyNumberMethods.nb_add -- C Member: binaryfunc PyNumberMethods.nb_subtract -- C Member: binaryfunc PyNumberMethods.nb_multiply -- C Member: binaryfunc PyNumberMethods.nb_remainder -- C Member: binaryfunc PyNumberMethods.nb_divmod -- C Member: ternaryfunc PyNumberMethods.nb_power -- C Member: unaryfunc PyNumberMethods.nb_negative -- C Member: unaryfunc PyNumberMethods.nb_positive -- C Member: unaryfunc PyNumberMethods.nb_absolute -- C Member: inquiry PyNumberMethods.nb_bool -- C Member: unaryfunc PyNumberMethods.nb_invert -- C Member: binaryfunc PyNumberMethods.nb_lshift -- C Member: binaryfunc PyNumberMethods.nb_rshift -- C Member: binaryfunc PyNumberMethods.nb_and -- C Member: binaryfunc PyNumberMethods.nb_xor -- C Member: binaryfunc PyNumberMethods.nb_or -- C Member: unaryfunc PyNumberMethods.nb_int -- C Member: void *PyNumberMethods.nb_reserved -- C Member: unaryfunc PyNumberMethods.nb_float -- C Member: binaryfunc PyNumberMethods.nb_inplace_add -- C Member: binaryfunc PyNumberMethods.nb_inplace_subtract -- C Member: binaryfunc PyNumberMethods.nb_inplace_multiply -- C Member: binaryfunc PyNumberMethods.nb_inplace_remainder -- C Member: ternaryfunc PyNumberMethods.nb_inplace_power -- C Member: binaryfunc PyNumberMethods.nb_inplace_lshift -- C Member: binaryfunc PyNumberMethods.nb_inplace_rshift -- C Member: binaryfunc PyNumberMethods.nb_inplace_and -- C Member: binaryfunc PyNumberMethods.nb_inplace_xor -- C Member: binaryfunc PyNumberMethods.nb_inplace_or -- C Member: binaryfunc PyNumberMethods.nb_floor_divide -- C Member: binaryfunc PyNumberMethods.nb_true_divide -- C Member: binaryfunc PyNumberMethods.nb_inplace_floor_divide -- C Member: binaryfunc PyNumberMethods.nb_inplace_true_divide -- C Member: unaryfunc PyNumberMethods.nb_index -- C Member: binaryfunc PyNumberMethods.nb_matrix_multiply -- C Member: binaryfunc PyNumberMethods.nb_inplace_matrix_multiply  File: python.info, Node: Mapping Object Structures, Next: Sequence Object Structures, Prev: Number Object Structures, Up: Object Implementation Support 7.12.5 Mapping Object Structures -------------------------------- -- C Type: PyMappingMethods This structure holds pointers to the functions which an object uses to implement the mapping protocol. It has three members: -- C Member: lenfunc PyMappingMethods.mp_length This function is used by *note PyMapping_Size(): 3a5f. and *note PyObject_Size(): 3a19, and has the same signature. This slot may be set to ‘NULL’ if the object has no defined length. -- C Member: binaryfunc PyMappingMethods.mp_subscript This function is used by *note PyObject_GetItem(): 38f5. and *note PySequence_GetSlice(): 3a4c, and has the same signature as ‘PyObject_GetItem()’. This slot must be filled for the *note PyMapping_Check(): 3a5e. function to return ‘1’, it can be ‘NULL’ otherwise. -- C Member: objobjargproc PyMappingMethods.mp_ass_subscript This function is used by *note PyObject_SetItem(): 38f3, *note PyObject_DelItem(): 3a1b, ‘PyObject_SetSlice()’ and ‘PyObject_DelSlice()’. It has the same signature as ‘PyObject_SetItem()’, but `v' can also be set to ‘NULL’ to delete an item. If this slot is ‘NULL’, the object does not support item assignment and deletion.  File: python.info, Node: Sequence Object Structures, Next: Buffer Object Structures, Prev: Mapping Object Structures, Up: Object Implementation Support 7.12.6 Sequence Object Structures --------------------------------- -- C Type: PySequenceMethods This structure holds pointers to the functions which an object uses to implement the sequence protocol. -- C Member: lenfunc PySequenceMethods.sq_length This function is used by *note PySequence_Size(): 3a46. and *note PyObject_Size(): 3a19, and has the same signature. It is also used for handling negative indices via the *note sq_item: 3e0d. and the *note sq_ass_item: 3e0e. slots. -- C Member: binaryfunc PySequenceMethods.sq_concat This function is used by *note PySequence_Concat(): 3a48. and has the same signature. It is also used by the ‘+’ operator, after trying the numeric addition via the *note nb_add: 3ac8. slot. -- C Member: ssizeargfunc PySequenceMethods.sq_repeat This function is used by *note PySequence_Repeat(): 3a49. and has the same signature. It is also used by the ‘*’ operator, after trying numeric multiplication via the *note nb_multiply: 3de5. slot. -- C Member: ssizeargfunc PySequenceMethods.sq_item This function is used by *note PySequence_GetItem(): 38f6. and has the same signature. It is also used by *note PyObject_GetItem(): 38f5, after trying the subscription via the *note mp_subscript: 3e07. slot. This slot must be filled for the *note PySequence_Check(): 3a45. function to return ‘1’, it can be ‘NULL’ otherwise. Negative indexes are handled as follows: if the ‘sq_length’ slot is filled, it is called and the sequence length is used to compute a positive index which is passed to ‘sq_item’. If ‘sq_length’ is ‘NULL’, the index is passed as is to the function. -- C Member: ssizeobjargproc PySequenceMethods.sq_ass_item This function is used by *note PySequence_SetItem(): 38f2. and has the same signature. It is also used by *note PyObject_SetItem(): 38f3. and *note PyObject_DelItem(): 3a1b, after trying the item assignment and deletion via the *note mp_ass_subscript: 3e08. slot. This slot may be left to ‘NULL’ if the object does not support item assignment and deletion. -- C Member: objobjproc PySequenceMethods.sq_contains This function may be used by *note PySequence_Contains(): 3a51. and has the same signature. This slot may be left to ‘NULL’, in this case ‘PySequence_Contains()’ simply traverses the sequence until it finds a match. -- C Member: binaryfunc PySequenceMethods.sq_inplace_concat This function is used by *note PySequence_InPlaceConcat(): 3a4a. and has the same signature. It should modify its first operand, and return it. This slot may be left to ‘NULL’, in this case ‘PySequence_InPlaceConcat()’ will fall back to *note PySequence_Concat(): 3a48. It is also used by the augmented assignment ‘+=’, after trying numeric in-place addition via the *note nb_inplace_add: 3de2. slot. -- C Member: ssizeargfunc PySequenceMethods.sq_inplace_repeat This function is used by *note PySequence_InPlaceRepeat(): 3a4b. and has the same signature. It should modify its first operand, and return it. This slot may be left to ‘NULL’, in this case ‘PySequence_InPlaceRepeat()’ will fall back to *note PySequence_Repeat(): 3a49. It is also used by the augmented assignment ‘*=’, after trying numeric in-place multiplication via the *note nb_inplace_multiply: 3de6. slot.  File: python.info, Node: Buffer Object Structures, Next: Async Object Structures, Prev: Sequence Object Structures, Up: Object Implementation Support 7.12.7 Buffer Object Structures ------------------------------- -- C Type: PyBufferProcs This structure holds pointers to the functions required by the *note Buffer protocol: 1291. The protocol defines how an exporter object can expose its internal data to consumer objects. -- C Member: getbufferproc PyBufferProcs.bf_getbuffer The signature of this function is: int (PyObject *exporter, Py_buffer *view, int flags); Handle a request to `exporter' to fill in `view' as specified by `flags'. Except for point (3), an implementation of this function MUST take these steps: 1. Check if the request can be met. If not, raise ‘PyExc_BufferError’, set ‘view->obj’ to ‘NULL’ and return ‘-1’. 2. Fill in the requested fields. 3. Increment an internal counter for the number of exports. 4. Set ‘view->obj’ to `exporter' and increment ‘view->obj’. 5. Return ‘0’. If `exporter' is part of a chain or tree of buffer providers, two main schemes can be used: * Re-export: Each member of the tree acts as the exporting object and sets ‘view->obj’ to a new reference to itself. * Redirect: The buffer request is redirected to the root object of the tree. Here, ‘view->obj’ will be a new reference to the root object. The individual fields of `view' are described in section *note Buffer structure: 3a6f, the rules how an exporter must react to specific requests are in section *note Buffer request types: 3a83. All memory pointed to in the *note Py_buffer: b1b. structure belongs to the exporter and must remain valid until there are no consumers left. *note format: 3a7c, *note shape: 3a7e, *note strides: 3a73, *note suboffsets: 3a80. and *note internal: 3a82. are read-only for the consumer. *note PyBuffer_FillInfo(): 3a76. provides an easy way of exposing a simple bytes buffer while dealing correctly with all request types. *note PyObject_GetBuffer(): d25. is the interface for the consumer that wraps this function. -- C Member: releasebufferproc PyBufferProcs.bf_releasebuffer The signature of this function is: void (PyObject *exporter, Py_buffer *view); Handle a request to release the resources of the buffer. If no resources need to be released, *note PyBufferProcs.bf_releasebuffer: 39c9. may be ‘NULL’. Otherwise, a standard implementation of this function will take these optional steps: 1. Decrement an internal counter for the number of exports. 2. If the counter is ‘0’, free all memory associated with `view'. The exporter MUST use the *note internal: 3a82. field to keep track of buffer-specific resources. This field is guaranteed to remain constant, while a consumer MAY pass a copy of the original buffer as the `view' argument. This function MUST NOT decrement ‘view->obj’, since that is done automatically in *note PyBuffer_Release(): d54. (this scheme is useful for breaking reference cycles). *note PyBuffer_Release(): d54. is the interface for the consumer that wraps this function.  File: python.info, Node: Async Object Structures, Next: Slot Type typedefs, Prev: Buffer Object Structures, Up: Object Implementation Support 7.12.8 Async Object Structures ------------------------------ New in version 3.5. -- C Type: PyAsyncMethods This structure holds pointers to the functions required to implement *note awaitable: 519. and *note asynchronous iterator: 645. objects. Here is the structure definition: typedef struct { unaryfunc am_await; unaryfunc am_aiter; unaryfunc am_anext; } PyAsyncMethods; -- C Member: unaryfunc PyAsyncMethods.am_await The signature of this function is: PyObject *am_await(PyObject *self); The returned object must be an iterator, i.e. *note PyIter_Check(): 3a6a. must return ‘1’ for it. This slot may be set to ‘NULL’ if an object is not an *note awaitable: 519. -- C Member: unaryfunc PyAsyncMethods.am_aiter The signature of this function is: PyObject *am_aiter(PyObject *self); Must return an *note awaitable: 519. object. See *note __anext__(): 1138. for details. This slot may be set to ‘NULL’ if an object does not implement asynchronous iteration protocol. -- C Member: unaryfunc PyAsyncMethods.am_anext The signature of this function is: PyObject *am_anext(PyObject *self); Must return an *note awaitable: 519. object. See *note __anext__(): 1138. for details. This slot may be set to ‘NULL’.  File: python.info, Node: Slot Type typedefs, Next: Examples<35>, Prev: Async Object Structures, Up: Object Implementation Support 7.12.9 Slot Type typedefs ------------------------- -- C Type: PyObject *(*allocfunc) (PyTypeObject *cls, Py_ssize_t nitems) The purpose of this function is to separate memory allocation from memory initialization. It should return a pointer to a block of memory of adequate length for the instance, suitably aligned, and initialized to zeros, but with ‘ob_refcnt’ set to ‘1’ and ‘ob_type’ set to the type argument. If the type’s *note tp_itemsize: 3878. is non-zero, the object’s ‘ob_size’ field should be initialized to `nitems' and the length of the allocated memory block should be ‘tp_basicsize + nitems*tp_itemsize’, rounded up to a multiple of ‘sizeof(void*)’; otherwise, `nitems' is not used and the length of the block should be *note tp_basicsize: 3879. This function should not do any other instance initialization, not even to allocate additional memory; that should be done by *note tp_new: 387c. -- C Type: void (*destructor) (PyObject *) -- C Type: PyObject *(*vectorcallfunc) (PyObject *callable, PyObject *const *args, size_t nargsf, PyObject *kwnames) See *note tp_vectorcall_offset: 3a11. Arguments to ‘vectorcallfunc’ are the same as for *note _PyObject_Vectorcall(): 3a10. New in version 3.8. -- C Type: void (*freefunc) (void *) See *note tp_free: 3880. -- C Type: PyObject *(*newfunc) (PyObject *, PyObject *, PyObject *) See *note tp_new: 387c. -- C Type: int (*initproc) (PyObject *, PyObject *, PyObject *) See *note tp_init: 3883. -- C Type: PyObject *(*reprfunc) (PyObject *) See *note tp_repr: 389a. -- C Type: PyObject *(*getattrfunc) (PyObject *self, char *attr) Return the value of the named attribute for the object. -- C Type: int (*setattrfunc) (PyObject *self, char *attr, PyObject *value) Set the value of the named attribute for the object. The value argument is set to ‘NULL’ to delete the attribute. -- C Type: PyObject *(*getattrofunc) (PyObject *self, PyObject *attr) Return the value of the named attribute for the object. See *note tp_getattro: 389f. -- C Type: int (*setattrofunc) (PyObject *self, PyObject *attr, PyObject *value) Set the value of the named attribute for the object. The value argument is set to ‘NULL’ to delete the attribute. See *note tp_setattro: 38a0. -- C Type: PyObject *(*descrgetfunc) (PyObject *, PyObject *, PyObject *) See ‘tp_descrget’. -- C Type: int (*descrsetfunc) (PyObject *, PyObject *, PyObject *) See ‘tp_descrset’. -- C Type: Py_hash_t (*hashfunc) (PyObject *) See *note tp_hash: 38ac. -- C Type: PyObject *(*richcmpfunc) (PyObject *, PyObject *, int) See *note tp_richcompare: 38a5. -- C Type: PyObject *(*getiterfunc) (PyObject *) See *note tp_iter: e30. -- C Type: PyObject *(*iternextfunc) (PyObject *) See *note tp_iternext: e31. -- C Type: Py_ssize_t (*lenfunc) (PyObject *) -- C Type: int (*getbufferproc) (PyObject *, Py_buffer *, int) -- C Type: void (*releasebufferproc) (PyObject *, Py_buffer *) -- C Type: PyObject *(*unaryfunc) (PyObject *) -- C Type: PyObject *(*binaryfunc) (PyObject *, PyObject *) -- C Type: PyObject *(*ternaryfunc) (PyObject *, PyObject *, PyObject *) -- C Type: PyObject *(*ssizeargfunc) (PyObject *, Py_ssize_t) -- C Type: int (*ssizeobjargproc) (PyObject *, Py_ssize_t) -- C Type: int (*objobjproc) (PyObject *, PyObject *) -- C Type: int (*objobjargproc) (PyObject *, PyObject *, PyObject *)  File: python.info, Node: Examples<35>, Next: Supporting Cyclic Garbage Collection, Prev: Slot Type typedefs, Up: Object Implementation Support 7.12.10 Examples ---------------- The following are simple examples of Python type definitions. They include common usage you may encounter. Some demonstrate tricky corner cases. For more examples, practical info, and a tutorial, see *note Defining Extension Types; Tutorial: 3871. and *note Defining Extension Types; Assorted Topics: 3894. A basic static type: typedef struct { PyObject_HEAD const char *data; } MyObject; static PyTypeObject MyObject_Type = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "mymod.MyObject", .tp_basicsize = sizeof(MyObject), .tp_doc = "My objects", .tp_new = myobj_new, .tp_dealloc = (destructor)myobj_dealloc, .tp_repr = (reprfunc)myobj_repr, }; You may also find older code (especially in the CPython code base) with a more verbose initializer: static PyTypeObject MyObject_Type = { PyVarObject_HEAD_INIT(NULL, 0) "mymod.MyObject", /* tp_name */ sizeof(MyObject), /* tp_basicsize */ 0, /* tp_itemsize */ (destructor)myobj_dealloc, /* tp_dealloc */ 0, /* tp_vectorcall_offset */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_as_async */ (reprfunc)myobj_repr, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ 0, /* tp_call */ 0, /* tp_str */ 0, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ 0, /* tp_flags */ "My objects", /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ 0, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ 0, /* tp_init */ 0, /* tp_alloc */ myobj_new, /* tp_new */ }; A type that supports weakrefs, instance dicts, and hashing: typedef struct { PyObject_HEAD const char *data; PyObject *inst_dict; PyObject *weakreflist; } MyObject; static PyTypeObject MyObject_Type = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "mymod.MyObject", .tp_basicsize = sizeof(MyObject), .tp_doc = "My objects", .tp_weaklistoffset = offsetof(MyObject, weakreflist), .tp_dictoffset = offsetof(MyObject, inst_dict), .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, .tp_new = myobj_new, .tp_traverse = (traverseproc)myobj_traverse, .tp_clear = (inquiry)myobj_clear, .tp_alloc = PyType_GenericNew, .tp_dealloc = (destructor)myobj_dealloc, .tp_repr = (reprfunc)myobj_repr, .tp_hash = (hashfunc)myobj_hash, .tp_richcompare = PyBaseObject_Type.tp_richcompare, }; A str subclass that cannot be subclassed and cannot be called to create instances (e.g. uses a separate factory func): typedef struct { PyUnicodeObject raw; char *extra; } MyStr; static PyTypeObject MyStr_Type = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "mymod.MyStr", .tp_basicsize = sizeof(MyStr), .tp_base = NULL, // set to &PyUnicode_Type in module init .tp_doc = "my custom str", .tp_flags = Py_TPFLAGS_DEFAULT, .tp_new = NULL, .tp_repr = (reprfunc)myobj_repr, }; The simplest static type (with fixed-length instances): typedef struct { PyObject_HEAD } MyObject; static PyTypeObject MyObject_Type = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "mymod.MyObject", }; The simplest static type (with variable-length instances): typedef struct { PyObject_VAR_HEAD const char *data[1]; } MyObject; static PyTypeObject MyObject_Type = { PyVarObject_HEAD_INIT(NULL, 0) .tp_name = "mymod.MyObject", .tp_basicsize = sizeof(MyObject) - sizeof(char *), .tp_itemsize = sizeof(char *), };  File: python.info, Node: Supporting Cyclic Garbage Collection, Prev: Examples<35>, Up: Object Implementation Support 7.12.11 Supporting Cyclic Garbage Collection -------------------------------------------- Python’s support for detecting and collecting garbage which involves circular references requires support from object types which are “containers” for other objects which may also be containers. Types which do not store references to other objects, or which only store references to atomic types (such as numbers or strings), do not need to provide any explicit support for garbage collection. To create a container type, the *note tp_flags: 3ab6. field of the type object must include the *note Py_TPFLAGS_HAVE_GC: 388e. and provide an implementation of the *note tp_traverse: 33e8. handler. If instances of the type are mutable, a *note tp_clear: 3898. implementation must also be provided. -- Data: Py_TPFLAGS_HAVE_GC Objects with a type with this flag set must conform with the rules documented here. For convenience these objects will be referred to as container objects. Constructors for container types must conform to two rules: 1. The memory for the object must be allocated using *note PyObject_GC_New(): 2d4. or *note PyObject_GC_NewVar(): 2d5. 2. Once all the fields which may contain references to other containers are initialized, it must call *note PyObject_GC_Track(): e44. -- C Function: TYPE* PyObject_GC_New (TYPE, PyTypeObject *type) Analogous to *note PyObject_New(): 2d2. but for container objects with the *note Py_TPFLAGS_HAVE_GC: 388e. flag set. -- C Function: TYPE* PyObject_GC_NewVar (TYPE, PyTypeObject *type, Py_ssize_t size) Analogous to *note PyObject_NewVar(): 2d3. but for container objects with the *note Py_TPFLAGS_HAVE_GC: 388e. flag set. -- C Function: TYPE* PyObject_GC_Resize (TYPE, PyVarObject *op, Py_ssize_t newsize) Resize an object allocated by *note PyObject_NewVar(): 2d3. Returns the resized object or ‘NULL’ on failure. `op' must not be tracked by the collector yet. -- C Function: void PyObject_GC_Track (PyObject *op) Adds the object `op' to the set of container objects tracked by the collector. The collector can run at unexpected times so objects must be valid while being tracked. This should be called once all the fields followed by the *note tp_traverse: 33e8. handler become valid, usually near the end of the constructor. Similarly, the deallocator for the object must conform to a similar pair of rules: 1. Before fields which refer to other containers are invalidated, *note PyObject_GC_UnTrack(): e45. must be called. 2. The object’s memory must be deallocated using *note PyObject_GC_Del(): e43. -- C Function: void PyObject_GC_Del (void *op) Releases memory allocated to an object using *note PyObject_GC_New(): 2d4. or *note PyObject_GC_NewVar(): 2d5. -- C Function: void PyObject_GC_UnTrack (void *op) Remove the object `op' from the set of container objects tracked by the collector. Note that *note PyObject_GC_Track(): e44. can be called again on this object to add it back to the set of tracked objects. The deallocator (*note tp_dealloc: 387f. handler) should call this for the object before any of the fields used by the *note tp_traverse: 33e8. handler become invalid. Changed in version 3.8: The ‘_PyObject_GC_TRACK()’ and ‘_PyObject_GC_UNTRACK()’ macros have been removed from the public C API. The *note tp_traverse: 33e8. handler accepts a function parameter of this type: -- C Type: int (*visitproc) (PyObject *object, void *arg) Type of the visitor function passed to the *note tp_traverse: 33e8. handler. The function should be called with an object to traverse as `object' and the third parameter to the *note tp_traverse: 33e8. handler as `arg'. The Python core uses several visitor functions to implement cyclic garbage detection; it’s not expected that users will need to write their own visitor functions. The *note tp_traverse: 33e8. handler must have the following type: -- C Type: int (*traverseproc) (PyObject *self, visitproc visit, void *arg) Traversal function for a container object. Implementations must call the `visit' function for each object directly contained by `self', with the parameters to `visit' being the contained object and the `arg' value passed to the handler. The `visit' function must not be called with a ‘NULL’ object argument. If `visit' returns a non-zero value that value should be returned immediately. To simplify writing *note tp_traverse: 33e8. handlers, a *note Py_VISIT(): 388c. macro is provided. In order to use this macro, the *note tp_traverse: 33e8. implementation must name its arguments exactly `visit' and `arg': -- C Function: void Py_VISIT (PyObject *o) If `o' is not ‘NULL’, call the `visit' callback, with arguments `o' and `arg'. If `visit' returns a non-zero value, then return it. Using this macro, *note tp_traverse: 33e8. handlers look like: static int my_traverse(Noddy *self, visitproc visit, void *arg) { Py_VISIT(self->foo); Py_VISIT(self->bar); return 0; } The *note tp_clear: 3898. handler must be of the *note inquiry: 3dc7. type, or ‘NULL’ if the object is immutable. -- C Type: int (*inquiry) (PyObject *self) Drop references that may have created reference cycles. Immutable objects do not have to define this method since they can never directly create reference cycles. Note that the object must still be valid after calling this method (don’t just call *note Py_DECREF(): 266. on a reference). The collector will call this method if it detects that this object is involved in a reference cycle.  File: python.info, Node: API and ABI Versioning, Prev: Object Implementation Support, Up: Python/C API Reference Manual 7.13 API and ABI Versioning =========================== ‘PY_VERSION_HEX’ is the Python version number encoded in a single integer. For example if the ‘PY_VERSION_HEX’ is set to ‘0x030401a2’, the underlying version information can be found by treating it as a 32 bit number in the following manner: Bytes Bits (big endian order) Meaning ----------------------------------------------------------------------------------------------- ‘1’ ‘1-8’ ‘PY_MAJOR_VERSION’ (the ‘3’ in ‘3.4.1a2’) ‘2’ ‘9-16’ ‘PY_MINOR_VERSION’ (the ‘4’ in ‘3.4.1a2’) ‘3’ ‘17-24’ ‘PY_MICRO_VERSION’ (the ‘1’ in ‘3.4.1a2’) ‘4’ ‘25-28’ ‘PY_RELEASE_LEVEL’ (‘0xA’ for alpha, ‘0xB’ for beta, ‘0xC’ for release candidate and ‘0xF’ for final), in this case it is alpha. ‘29-32’ ‘PY_RELEASE_SERIAL’ (the ‘2’ in ‘3.4.1a2’, zero for final releases) Thus ‘3.4.1a2’ is hexversion ‘0x030401a2’. All the given macros are defined in Include/patchlevel.h(1). ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Include/patchlevel.h  File: python.info, Node: Distributing Python Modules, Next: Installing Python Modules, Prev: Python/C API Reference Manual, Up: Top 8 Distributing Python Modules ***************************** Email: <distutils-sig@python.org> As a popular open source development project, Python has an active supporting community of contributors and users that also make their software available for other Python developers to use under open source license terms. This allows Python users to share and collaborate effectively, benefiting from the solutions others have already created to common (and sometimes even rare!) problems, as well as potentially contributing their own solutions to the common pool. This guide covers the distribution part of the process. For a guide to installing other Python projects, refer to the *note installation guide: 7f5. Note: For corporate and other institutional users, be aware that many organisations have their own policies around using and contributing to open source software. Please take such policies into account when making use of the distribution and installation tools provided with Python. * Menu: * Key terms:: * Open source licensing and collaboration:: * Installing the tools:: * Reading the Python Packaging User Guide:: * How do I…?::  File: python.info, Node: Key terms, Next: Open source licensing and collaboration, Up: Distributing Python Modules 8.1 Key terms ============= * the Python Packaging Index(1) is a public repository of open source licensed packages made available for use by other Python users * the Python Packaging Authority(2) are the group of developers and documentation authors responsible for the maintenance and evolution of the standard packaging tools and the associated metadata and file format standards. They maintain a variety of tools, documentation and issue trackers on both GitHub(3) and Bitbucket(4). * *note distutils: 39. is the original build and distribution system first added to the Python standard library in 1998. While direct use of *note distutils: 39. is being phased out, it still laid the foundation for the current packaging and distribution infrastructure, and it not only remains part of the standard library, but its name lives on in other ways (such as the name of the mailing list used to coordinate Python packaging standards development). * setuptools(5) is a (largely) drop-in replacement for *note distutils: 39. first published in 2004. Its most notable addition over the unmodified *note distutils: 39. tools was the ability to declare dependencies on other packages. It is currently recommended as a more regularly updated alternative to *note distutils: 39. that offers consistent support for more recent packaging standards across a wide range of Python versions. * wheel(6) (in this context) is a project that adds the ‘bdist_wheel’ command to *note distutils: 39./setuptools(7). This produces a cross platform binary packaging format (called “wheels” or “wheel files” and defined in PEP 427(8)) that allows Python libraries, even those including binary extensions, to be installed on a system without needing to be built locally. ---------- Footnotes ---------- (1) https://pypi.org (2) https://www.pypa.io/ (3) https://github.com/pypa (4) https://bitbucket.org/pypa/ (5) https://setuptools.readthedocs.io/en/latest/ (6) https://wheel.readthedocs.io/ (7) https://setuptools.readthedocs.io/en/latest/ (8) https://www.python.org/dev/peps/pep-0427  File: python.info, Node: Open source licensing and collaboration, Next: Installing the tools, Prev: Key terms, Up: Distributing Python Modules 8.2 Open source licensing and collaboration =========================================== In most parts of the world, software is automatically covered by copyright. This means that other developers require explicit permission to copy, use, modify and redistribute the software. Open source licensing is a way of explicitly granting such permission in a relatively consistent way, allowing developers to share and collaborate efficiently by making common solutions to various problems freely available. This leaves many developers free to spend more time focusing on the problems that are relatively unique to their specific situation. The distribution tools provided with Python are designed to make it reasonably straightforward for developers to make their own contributions back to that common pool of software if they choose to do so. The same distribution tools can also be used to distribute software within an organisation, regardless of whether that software is published as open source software or not.  File: python.info, Node: Installing the tools, Next: Reading the Python Packaging User Guide, Prev: Open source licensing and collaboration, Up: Distributing Python Modules 8.3 Installing the tools ======================== The standard library does not include build tools that support modern Python packaging standards, as the core development team has found that it is important to have standard tools that work consistently, even on older versions of Python. The currently recommended build and distribution tools can be installed by invoking the ‘pip’ module at the command line: python -m pip install setuptools wheel twine Note: For POSIX users (including Mac OS X and Linux users), these instructions assume the use of a *note virtual environment: fa8. For Windows users, these instructions assume that the option to adjust the system PATH environment variable was selected when installing Python. The Python Packaging User Guide includes more details on the currently recommended tools(1). ---------- Footnotes ---------- (1) https://packaging.python.org/guides/tool-recommendations/#packaging-tool-recommendations  File: python.info, Node: Reading the Python Packaging User Guide, Next: How do I…?, Prev: Installing the tools, Up: Distributing Python Modules 8.4 Reading the Python Packaging User Guide =========================================== The Python Packaging User Guide covers the various key steps and elements involved in creating and publishing a project: * Project structure(1) * Building and packaging the project(2) * Uploading the project to the Python Packaging Index(3) * The .pypirc file(4) ---------- Footnotes ---------- (1) https://packaging.python.org/tutorials/distributing-packages/ (2) https://packaging.python.org/tutorials/distributing-packages/#packaging-your-project (3) https://packaging.python.org/tutorials/distributing-packages/#uploading-your-project-to-pypi (4) https://packaging.python.org/specifications/pypirc/  File: python.info, Node: How do I…?, Prev: Reading the Python Packaging User Guide, Up: Distributing Python Modules 8.5 How do I…? ============== These are quick answers or links for some common tasks. * Menu: * … choose a name for my project?:: * … create and distribute binary extensions?::  File: python.info, Node: … choose a name for my project?, Next: … create and distribute binary extensions?, Up: How do I…? 8.5.1 … choose a name for my project? ------------------------------------- This isn’t an easy topic, but here are a few tips: * check the Python Packaging Index to see if the name is already in use * check popular hosting sites like GitHub, Bitbucket, etc to see if there is already a project with that name * check what comes up in a web search for the name you’re considering * avoid particularly common words, especially ones with multiple meanings, as they can make it difficult for users to find your software when searching for it  File: python.info, Node: … create and distribute binary extensions?, Prev: … choose a name for my project?, Up: How do I…? 8.5.2 … create and distribute binary extensions? ------------------------------------------------ This is actually quite a complex topic, with a variety of alternatives available depending on exactly what you’re aiming to achieve. See the Python Packaging User Guide for more information and recommendations. See also ........ Python Packaging User Guide: Binary Extensions(1) ---------- Footnotes ---------- (1) https://packaging.python.org/guides/packaging-binary-extensions/  File: python.info, Node: Installing Python Modules, Next: Python HOWTOs, Prev: Distributing Python Modules, Up: Top 9 Installing Python Modules *************************** Email: <distutils-sig@python.org> As a popular open source development project, Python has an active supporting community of contributors and users that also make their software available for other Python developers to use under open source license terms. This allows Python users to share and collaborate effectively, benefiting from the solutions others have already created to common (and sometimes even rare!) problems, as well as potentially contributing their own solutions to the common pool. This guide covers the installation part of the process. For a guide to creating and sharing your own Python projects, refer to the *note distribution guide: 7f6. Note: For corporate and other institutional users, be aware that many organisations have their own policies around using and contributing to open source software. Please take such policies into account when making use of the distribution and installation tools provided with Python. * Menu: * Key terms: Key terms<2>. * Basic usage:: * How do I …?:: * Common installation issues::  File: python.info, Node: Key terms<2>, Next: Basic usage, Up: Installing Python Modules 9.1 Key terms ============= * ‘pip’ is the preferred installer program. Starting with Python 3.4, it is included by default with the Python binary installers. * A `virtual environment' is a semi-isolated Python environment that allows packages to be installed for use by a particular application, rather than being installed system wide. * ‘venv’ is the standard tool for creating virtual environments, and has been part of Python since Python 3.3. Starting with Python 3.4, it defaults to installing ‘pip’ into all created virtual environments. * ‘virtualenv’ is a third party alternative (and predecessor) to ‘venv’. It allows virtual environments to be used on versions of Python prior to 3.4, which either don’t provide ‘venv’ at all, or aren’t able to automatically install ‘pip’ into created environments. * The Python Packaging Index(1) is a public repository of open source licensed packages made available for use by other Python users. * the Python Packaging Authority(2) is the group of developers and documentation authors responsible for the maintenance and evolution of the standard packaging tools and the associated metadata and file format standards. They maintain a variety of tools, documentation, and issue trackers on both GitHub(3) and Bitbucket(4). * ‘distutils’ is the original build and distribution system first added to the Python standard library in 1998. While direct use of ‘distutils’ is being phased out, it still laid the foundation for the current packaging and distribution infrastructure, and it not only remains part of the standard library, but its name lives on in other ways (such as the name of the mailing list used to coordinate Python packaging standards development). Changed in version 3.5: The use of ‘venv’ is now recommended for creating virtual environments. See also ........ Python Packaging User Guide: Creating and using virtual environments(5) ---------- Footnotes ---------- (1) https://pypi.org (2) https://www.pypa.io/ (3) https://github.com/pypa (4) https://bitbucket.org/pypa/ (5) https://packaging.python.org/installing/#creating-virtual-environments  File: python.info, Node: Basic usage, Next: How do I …?, Prev: Key terms<2>, Up: Installing Python Modules 9.2 Basic usage =============== The standard packaging tools are all designed to be used from the command line. The following command will install the latest version of a module and its dependencies from the Python Packaging Index: python -m pip install SomePackage Note: For POSIX users (including Mac OS X and Linux users), the examples in this guide assume the use of a *note virtual environment: fa8. For Windows users, the examples in this guide assume that the option to adjust the system PATH environment variable was selected when installing Python. It’s also possible to specify an exact or minimum version directly on the command line. When using comparator operators such as ‘>’, ‘<’ or some other special character which get interpreted by shell, the package name and the version should be enclosed within double quotes: python -m pip install SomePackage==1.0.4 # specific version python -m pip install "SomePackage>=1.0.4" # minimum version Normally, if a suitable module is already installed, attempting to install it again will have no effect. Upgrading existing modules must be requested explicitly: python -m pip install --upgrade SomePackage More information and resources regarding ‘pip’ and its capabilities can be found in the Python Packaging User Guide(1). Creation of virtual environments is done through the *note venv: 125. module. Installing packages into an active virtual environment uses the commands shown above. See also ........ Python Packaging User Guide: Installing Python Distribution Packages(2) ---------- Footnotes ---------- (1) https://packaging.python.org (2) https://packaging.python.org/installing/  File: python.info, Node: How do I …?, Next: Common installation issues, Prev: Basic usage, Up: Installing Python Modules 9.3 How do I …? =============== These are quick answers or links for some common tasks. * Menu: * … install pip in versions of Python prior to Python 3.4?: … install pip in versions of Python prior to Python 3 4?. * … install packages just for the current user?:: * … install scientific Python packages?:: * … work with multiple versions of Python installed in parallel?::  File: python.info, Node: … install pip in versions of Python prior to Python 3 4?, Next: … install packages just for the current user?, Up: How do I …? 9.3.1 … install ‘pip’ in versions of Python prior to Python 3.4? ---------------------------------------------------------------- Python only started bundling ‘pip’ with Python 3.4. For earlier versions, ‘pip’ needs to be “bootstrapped” as described in the Python Packaging User Guide. See also ........ Python Packaging User Guide: Requirements for Installing Packages(1) ---------- Footnotes ---------- (1) https://packaging.python.org/installing/#requirements-for-installing-packages  File: python.info, Node: … install packages just for the current user?, Next: … install scientific Python packages?, Prev: … install pip in versions of Python prior to Python 3 4?, Up: How do I …? 9.3.2 … install packages just for the current user? --------------------------------------------------- Passing the ‘--user’ option to ‘python -m pip install’ will install a package just for the current user, rather than for all users of the system.  File: python.info, Node: … install scientific Python packages?, Next: … work with multiple versions of Python installed in parallel?, Prev: … install packages just for the current user?, Up: How do I …? 9.3.3 … install scientific Python packages? ------------------------------------------- A number of scientific Python packages have complex binary dependencies, and aren’t currently easy to install using ‘pip’ directly. At this point in time, it will often be easier for users to install these packages by other means(1) rather than attempting to install them with ‘pip’. See also ........ Python Packaging User Guide: Installing Scientific Packages(2) ---------- Footnotes ---------- (1) https://packaging.python.org/science/ (2) https://packaging.python.org/science/  File: python.info, Node: … work with multiple versions of Python installed in parallel?, Prev: … install scientific Python packages?, Up: How do I …? 9.3.4 … work with multiple versions of Python installed in parallel? -------------------------------------------------------------------- On Linux, Mac OS X, and other POSIX systems, use the versioned Python commands in combination with the ‘-m’ switch to run the appropriate copy of ‘pip’: python2 -m pip install SomePackage # default Python 2 python2.7 -m pip install SomePackage # specifically Python 2.7 python3 -m pip install SomePackage # default Python 3 python3.4 -m pip install SomePackage # specifically Python 3.4 Appropriately versioned ‘pip’ commands may also be available. On Windows, use the ‘py’ Python launcher in combination with the ‘-m’ switch: py -2 -m pip install SomePackage # default Python 2 py -2.7 -m pip install SomePackage # specifically Python 2.7 py -3 -m pip install SomePackage # default Python 3 py -3.4 -m pip install SomePackage # specifically Python 3.4  File: python.info, Node: Common installation issues, Prev: How do I …?, Up: Installing Python Modules 9.4 Common installation issues ============================== * Menu: * Installing into the system Python on Linux:: * Pip not installed:: * Installing binary extensions::  File: python.info, Node: Installing into the system Python on Linux, Next: Pip not installed, Up: Common installation issues 9.4.1 Installing into the system Python on Linux ------------------------------------------------ On Linux systems, a Python installation will typically be included as part of the distribution. Installing into this Python installation requires root access to the system, and may interfere with the operation of the system package manager and other components of the system if a component is unexpectedly upgraded using ‘pip’. On such systems, it is often better to use a virtual environment or a per-user installation when installing packages with ‘pip’.  File: python.info, Node: Pip not installed, Next: Installing binary extensions, Prev: Installing into the system Python on Linux, Up: Common installation issues 9.4.2 Pip not installed ----------------------- It is possible that ‘pip’ does not get installed by default. One potential fix is: python -m ensurepip --default-pip There are also additional resources for installing pip.(1) ---------- Footnotes ---------- (1) https://packaging.python.org/tutorials/installing-packages/#install-pip-setuptools-and-wheel  File: python.info, Node: Installing binary extensions, Prev: Pip not installed, Up: Common installation issues 9.4.3 Installing binary extensions ---------------------------------- Python has typically relied heavily on source based distribution, with end users being expected to compile extension modules from source as part of the installation process. With the introduction of support for the binary ‘wheel’ format, and the ability to publish wheels for at least Windows and Mac OS X through the Python Packaging Index, this problem is expected to diminish over time, as users are more regularly able to install pre-built extensions rather than needing to build them themselves. Some of the solutions for installing scientific software(1) that are not yet available as pre-built ‘wheel’ files may also help with obtaining other binary extensions without needing to build them locally. See also ........ Python Packaging User Guide: Binary Extensions(2) ---------- Footnotes ---------- (1) https://packaging.python.org/science/ (2) https://packaging.python.org/extensions/  File: python.info, Node: Python HOWTOs, Next: Python Frequently Asked Questions, Prev: Installing Python Modules, Up: Top 10 Python HOWTOs **************** Python HOWTOs are documents that cover a single, specific topic, and attempt to cover it fairly completely. Modelled on the Linux Documentation Project’s HOWTO collection, this collection is an effort to foster documentation that’s more detailed than the Python Library Reference. Currently, the HOWTOs are: * Menu: * Porting Python 2 Code to Python 3:: * Porting Extension Modules to Python 3:: * Curses Programming with Python:: * Descriptor HowTo Guide:: * Functional Programming HOWTO:: * Logging HOWTO:: * Logging Cookbook:: * Regular Expression HOWTO:: * Socket Programming HOWTO:: * Sorting HOW TO:: * Unicode HOWTO:: * HOWTO Fetch Internet Resources Using The urllib Package:: * Argparse Tutorial:: * An introduction to the ipaddress module:: * Argument Clinic How-To:: * Instrumenting CPython with DTrace and SystemTap::  File: python.info, Node: Porting Python 2 Code to Python 3, Next: Porting Extension Modules to Python 3, Up: Python HOWTOs 10.1 Porting Python 2 Code to Python 3 ====================================== author: Brett Cannon Abstract ........ With Python 3 being the future of Python while Python 2 is still in active use, it is good to have your project available for both major releases of Python. This guide is meant to help you figure out how best to support both Python 2 & 3 simultaneously. If you are looking to port an extension module instead of pure Python code, please see *note Porting Extension Modules to Python 3: c77. If you would like to read one core Python developer’s take on why Python 3 came into existence, you can read Nick Coghlan’s Python 3 Q & A(1) or Brett Cannon’s Why Python 3 exists(2). For help with porting, you can email the python-porting(3) mailing list with questions. * Menu: * The Short Explanation:: * Details:: ---------- Footnotes ---------- (1) https://ncoghlan-devs-python-notes.readthedocs.io/en/latest/python3/questions_and_answers.html (2) https://snarky.ca/why-python-3-exists (3) https://mail.python.org/mailman/listinfo/python-porting  File: python.info, Node: The Short Explanation, Next: Details, Up: Porting Python 2 Code to Python 3 10.1.1 The Short Explanation ---------------------------- To make your project be single-source Python 2/3 compatible, the basic steps are: 1. Only worry about supporting Python 2.7 2. Make sure you have good test coverage (coverage.py(1) can help; ‘pip install coverage’) 3. Learn the differences between Python 2 & 3 4. Use Futurize(2) (or Modernize(3)) to update your code (e.g. ‘pip install future’) 5. Use Pylint(4) to help make sure you don’t regress on your Python 3 support (‘pip install pylint’) 6. Use caniusepython3(5) to find out which of your dependencies are blocking your use of Python 3 (‘pip install caniusepython3’) 7. Once your dependencies are no longer blocking you, use continuous integration to make sure you stay compatible with Python 2 & 3 (tox(6) can help test against multiple versions of Python; ‘pip install tox’) 8. Consider using optional static type checking to make sure your type usage works in both Python 2 & 3 (e.g. use mypy(7) to check your typing under both Python 2 & Python 3). ---------- Footnotes ---------- (1) https://pypi.org/project/coverage (2) http://python-future.org/automatic_conversion.html (3) https://python-modernize.readthedocs.io/ (4) https://pypi.org/project/pylint (5) https://pypi.org/project/caniusepython3 (6) https://pypi.org/project/tox (7) http://mypy-lang.org/  File: python.info, Node: Details, Prev: The Short Explanation, Up: Porting Python 2 Code to Python 3 10.1.2 Details -------------- A key point about supporting Python 2 & 3 simultaneously is that you can start `today'! Even if your dependencies are not supporting Python 3 yet that does not mean you can’t modernize your code `now' to support Python 3. Most changes required to support Python 3 lead to cleaner code using newer practices even in Python 2 code. Another key point is that modernizing your Python 2 code to also support Python 3 is largely automated for you. While you might have to make some API decisions thanks to Python 3 clarifying text data versus binary data, the lower-level work is now mostly done for you and thus can at least benefit from the automated changes immediately. Keep those key points in mind while you read on about the details of porting your code to support Python 2 & 3 simultaneously. * Menu: * Drop support for Python 2.6 and older: Drop support for Python 2 6 and older. * Make sure you specify the proper version support in your setup.py file: Make sure you specify the proper version support in your setup py file. * Have good test coverage:: * Learn the differences between Python 2 & 3:: * Update your code:: * Prevent compatibility regressions:: * Check which dependencies block your transition:: * Update your setup.py file to denote Python 3 compatibility: Update your setup py file to denote Python 3 compatibility. * Use continuous integration to stay compatible:: * Consider using optional static type checking::  File: python.info, Node: Drop support for Python 2 6 and older, Next: Make sure you specify the proper version support in your setup py file, Up: Details 10.1.2.1 Drop support for Python 2.6 and older .............................................. While you can make Python 2.5 work with Python 3, it is `much' easier if you only have to work with Python 2.7. If dropping Python 2.5 is not an option then the six(1) project can help you support Python 2.5 & 3 simultaneously (‘pip install six’). Do realize, though, that nearly all the projects listed in this HOWTO will not be available to you. If you are able to skip Python 2.5 and older, then the required changes to your code should continue to look and feel like idiomatic Python code. At worst you will have to use a function instead of a method in some instances or have to import a function instead of using a built-in one, but otherwise the overall transformation should not feel foreign to you. But you should aim for only supporting Python 2.7. Python 2.6 is no longer freely supported and thus is not receiving bugfixes. This means `you' will have to work around any issues you come across with Python 2.6. There are also some tools mentioned in this HOWTO which do not support Python 2.6 (e.g., Pylint(2)), and this will become more commonplace as time goes on. It will simply be easier for you if you only support the versions of Python that you have to support. ---------- Footnotes ---------- (1) https://pypi.org/project/six (2) https://pypi.org/project/pylint  File: python.info, Node: Make sure you specify the proper version support in your setup py file, Next: Have good test coverage, Prev: Drop support for Python 2 6 and older, Up: Details 10.1.2.2 Make sure you specify the proper version support in your ‘setup.py’ file ................................................................................. In your ‘setup.py’ file you should have the proper trove classifier(1) specifying what versions of Python you support. As your project does not support Python 3 yet you should at least have ‘Programming Language :: Python :: 2 :: Only’ specified. Ideally you should also specify each major/minor version of Python that you do support, e.g. ‘Programming Language :: Python :: 2.7’. ---------- Footnotes ---------- (1) https://pypi.org/classifiers  File: python.info, Node: Have good test coverage, Next: Learn the differences between Python 2 & 3, Prev: Make sure you specify the proper version support in your setup py file, Up: Details 10.1.2.3 Have good test coverage ................................ Once you have your code supporting the oldest version of Python 2 you want it to, you will want to make sure your test suite has good coverage. A good rule of thumb is that if you want to be confident enough in your test suite that any failures that appear after having tools rewrite your code are actual bugs in the tools and not in your code. If you want a number to aim for, try to get over 80% coverage (and don’t feel bad if you find it hard to get better than 90% coverage). If you don’t already have a tool to measure test coverage then coverage.py(1) is recommended. ---------- Footnotes ---------- (1) https://pypi.org/project/coverage  File: python.info, Node: Learn the differences between Python 2 & 3, Next: Update your code, Prev: Have good test coverage, Up: Details 10.1.2.4 Learn the differences between Python 2 & 3 ................................................... Once you have your code well-tested you are ready to begin porting your code to Python 3! But to fully understand how your code is going to change and what you want to look out for while you code, you will want to learn what changes Python 3 makes in terms of Python 2. Typically the two best ways of doing that is reading the *note “What’s New”: 149. doc for each release of Python 3 and the Porting to Python 3(1) book (which is free online). There is also a handy cheat sheet(2) from the Python-Future project. ---------- Footnotes ---------- (1) http://python3porting.com/ (2) http://python-future.org/compatible_idioms.html  File: python.info, Node: Update your code, Next: Prevent compatibility regressions, Prev: Learn the differences between Python 2 & 3, Up: Details 10.1.2.5 Update your code ......................... Once you feel like you know what is different in Python 3 compared to Python 2, it’s time to update your code! You have a choice between two tools in porting your code automatically: Futurize(1) and Modernize(2). Which tool you choose will depend on how much like Python 3 you want your code to be. Futurize(3) does its best to make Python 3 idioms and practices exist in Python 2, e.g. backporting the ‘bytes’ type from Python 3 so that you have semantic parity between the major versions of Python. Modernize(4), on the other hand, is more conservative and targets a Python 2/3 subset of Python, directly relying on six(5) to help provide compatibility. As Python 3 is the future, it might be best to consider Futurize to begin adjusting to any new practices that Python 3 introduces which you are not accustomed to yet. Regardless of which tool you choose, they will update your code to run under Python 3 while staying compatible with the version of Python 2 you started with. Depending on how conservative you want to be, you may want to run the tool over your test suite first and visually inspect the diff to make sure the transformation is accurate. After you have transformed your test suite and verified that all the tests still pass as expected, then you can transform your application code knowing that any tests which fail is a translation failure. Unfortunately the tools can’t automate everything to make your code work under Python 3 and so there are a handful of things you will need to update manually to get full Python 3 support (which of these steps are necessary vary between the tools). Read the documentation for the tool you choose to use to see what it fixes by default and what it can do optionally to know what will (not) be fixed for you and what you may have to fix on your own (e.g. using ‘io.open()’ over the built-in ‘open()’ function is off by default in Modernize). Luckily, though, there are only a couple of things to watch out for which can be considered large issues that may be hard to debug if not watched for. * Menu: * Division:: * Text versus binary data:: * Use feature detection instead of version detection:: ---------- Footnotes ---------- (1) http://python-future.org/automatic_conversion.html (2) https://python-modernize.readthedocs.io/ (3) http://python-future.org/automatic_conversion.html (4) https://python-modernize.readthedocs.io/ (5) https://pypi.org/project/six  File: python.info, Node: Division, Next: Text versus binary data, Up: Update your code 10.1.2.6 Division ................. In Python 3, ‘5 / 2 == 2.5’ and not ‘2’; all division between ‘int’ values result in a ‘float’. This change has actually been planned since Python 2.2 which was released in 2002. Since then users have been encouraged to add ‘from __future__ import division’ to any and all files which use the ‘/’ and ‘//’ operators or to be running the interpreter with the ‘-Q’ flag. If you have not been doing this then you will need to go through your code and do two things: 1. Add ‘from __future__ import division’ to your files 2. Update any division operator as necessary to either use ‘//’ to use floor division or continue using ‘/’ and expect a float The reason that ‘/’ isn’t simply translated to ‘//’ automatically is that if an object defines a ‘__truediv__’ method but not ‘__floordiv__’ then your code would begin to fail (e.g. a user-defined class that uses ‘/’ to signify some operation but not ‘//’ for the same thing or at all).  File: python.info, Node: Text versus binary data, Next: Use feature detection instead of version detection, Prev: Division, Up: Update your code 10.1.2.7 Text versus binary data ................................ In Python 2 you could use the ‘str’ type for both text and binary data. Unfortunately this confluence of two different concepts could lead to brittle code which sometimes worked for either kind of data, sometimes not. It also could lead to confusing APIs if people didn’t explicitly state that something that accepted ‘str’ accepted either text or binary data instead of one specific type. This complicated the situation especially for anyone supporting multiple languages as APIs wouldn’t bother explicitly supporting ‘unicode’ when they claimed text data support. To make the distinction between text and binary data clearer and more pronounced, Python 3 did what most languages created in the age of the internet have done and made text and binary data distinct types that cannot blindly be mixed together (Python predates widespread access to the internet). For any code that deals only with text or only binary data, this separation doesn’t pose an issue. But for code that has to deal with both, it does mean you might have to now care about when you are using text compared to binary data, which is why this cannot be entirely automated. To start, you will need to decide which APIs take text and which take binary (it is `highly' recommended you don’t design APIs that can take both due to the difficulty of keeping the code working; as stated earlier it is difficult to do well). In Python 2 this means making sure the APIs that take text can work with ‘unicode’ and those that work with binary data work with the ‘bytes’ type from Python 3 (which is a subset of ‘str’ in Python 2 and acts as an alias for ‘bytes’ type in Python 2). Usually the biggest issue is realizing which methods exist on which types in Python 2 & 3 simultaneously (for text that’s ‘unicode’ in Python 2 and ‘str’ in Python 3, for binary that’s ‘str’/‘bytes’ in Python 2 and ‘bytes’ in Python 3). The following table lists the `unique' methods of each data type across Python 2 & 3 (e.g., the ‘decode()’ method is usable on the equivalent binary data type in either Python 2 or 3, but it can’t be used by the textual data type consistently between Python 2 and 3 because ‘str’ in Python 3 doesn’t have the method). Do note that as of Python 3.5 the ‘__mod__’ method was added to the bytes type. `Text data' `Binary data' decode encode format isdecimal isnumeric Making the distinction easier to handle can be accomplished by encoding and decoding between binary data and text at the edge of your code. This means that when you receive text in binary data, you should immediately decode it. And if your code needs to send text as binary data then encode it as late as possible. This allows your code to work with only text internally and thus eliminates having to keep track of what type of data you are working with. The next issue is making sure you know whether the string literals in your code represent text or binary data. You should add a ‘b’ prefix to any literal that presents binary data. For text you should add a ‘u’ prefix to the text literal. (there is a *note __future__: 0. import to force all unspecified literals to be Unicode, but usage has shown it isn’t as effective as adding a ‘b’ or ‘u’ prefix to all literals explicitly) As part of this dichotomy you also need to be careful about opening files. Unless you have been working on Windows, there is a chance you have not always bothered to add the ‘b’ mode when opening a binary file (e.g., ‘rb’ for binary reading). Under Python 3, binary files and text files are clearly distinct and mutually incompatible; see the *note io: a1. module for details. Therefore, you `must' make a decision of whether a file will be used for binary access (allowing binary data to be read and/or written) or textual access (allowing text data to be read and/or written). You should also use *note io.open(): 65a. for opening files instead of the built-in *note open(): 4f0. function as the *note io: a1. module is consistent from Python 2 to 3 while the built-in *note open(): 4f0. function is not (in Python 3 it’s actually *note io.open(): 65a.). Do not bother with the outdated practice of using *note codecs.open(): ffe. as that’s only necessary for keeping compatibility with Python 2.5. The constructors of both ‘str’ and ‘bytes’ have different semantics for the same arguments between Python 2 & 3. Passing an integer to ‘bytes’ in Python 2 will give you the string representation of the integer: ‘bytes(3) == '3'’. But in Python 3, an integer argument to ‘bytes’ will give you a bytes object as long as the integer specified, filled with null bytes: ‘bytes(3) == b'\x00\x00\x00'’. A similar worry is necessary when passing a bytes object to ‘str’. In Python 2 you just get the bytes object back: ‘str(b'3') == b'3'’. But in Python 3 you get the string representation of the bytes object: ‘str(b'3') == "b'3'"’. Finally, the indexing of binary data requires careful handling (slicing does `not' require any special handling). In Python 2, ‘b'123'[1] == b'2'’ while in Python 3 ‘b'123'[1] == 50’. Because binary data is simply a collection of binary numbers, Python 3 returns the integer value for the byte you index on. But in Python 2 because ‘bytes == str’, indexing returns a one-item slice of bytes. The six(1) project has a function named ‘six.indexbytes()’ which will return an integer like in Python 3: ‘six.indexbytes(b'123', 1)’. To summarize: 1. Decide which of your APIs take text and which take binary data 2. Make sure that your code that works with text also works with ‘unicode’ and code for binary data works with ‘bytes’ in Python 2 (see the table above for what methods you cannot use for each type) 3. Mark all binary literals with a ‘b’ prefix, textual literals with a ‘u’ prefix 4. Decode binary data to text as soon as possible, encode text as binary data as late as possible 5. Open files using *note io.open(): 65a. and make sure to specify the ‘b’ mode when appropriate 6. Be careful when indexing into binary data ---------- Footnotes ---------- (1) https://pypi.org/project/six  File: python.info, Node: Use feature detection instead of version detection, Prev: Text versus binary data, Up: Update your code 10.1.2.8 Use feature detection instead of version detection ........................................................... Inevitably you will have code that has to choose what to do based on what version of Python is running. The best way to do this is with feature detection of whether the version of Python you’re running under supports what you need. If for some reason that doesn’t work then you should make the version check be against Python 2 and not Python 3. To help explain this, let’s look at an example. Let’s pretend that you need access to a feature of *note importlib: 9b. that is available in Python’s standard library since Python 3.3 and available for Python 2 through importlib2(1) on PyPI. You might be tempted to write code to access e.g. the *note importlib.abc: 9c. module by doing the following: import sys if sys.version_info[0] == 3: from importlib import abc else: from importlib2 import abc The problem with this code is what happens when Python 4 comes out? It would be better to treat Python 2 as the exceptional case instead of Python 3 and assume that future Python versions will be more compatible with Python 3 than Python 2: import sys if sys.version_info[0] > 2: from importlib import abc else: from importlib2 import abc The best solution, though, is to do no version detection at all and instead rely on feature detection. That avoids any potential issues of getting the version detection wrong and helps keep you future-compatible: try: from importlib import abc except ImportError: from importlib2 import abc ---------- Footnotes ---------- (1) https://pypi.org/project/importlib2  File: python.info, Node: Prevent compatibility regressions, Next: Check which dependencies block your transition, Prev: Update your code, Up: Details 10.1.2.9 Prevent compatibility regressions .......................................... Once you have fully translated your code to be compatible with Python 3, you will want to make sure your code doesn’t regress and stop working under Python 3. This is especially true if you have a dependency which is blocking you from actually running under Python 3 at the moment. To help with staying compatible, any new modules you create should have at least the following block of code at the top of it: from __future__ import absolute_import from __future__ import division from __future__ import print_function You can also run Python 2 with the ‘-3’ flag to be warned about various compatibility issues your code triggers during execution. If you turn warnings into errors with ‘-Werror’ then you can make sure that you don’t accidentally miss a warning. You can also use the Pylint(1) project and its ‘--py3k’ flag to lint your code to receive warnings when your code begins to deviate from Python 3 compatibility. This also prevents you from having to run Modernize(2) or Futurize(3) over your code regularly to catch compatibility regressions. This does require you only support Python 2.7 and Python 3.4 or newer as that is Pylint’s minimum Python version support. ---------- Footnotes ---------- (1) https://pypi.org/project/pylint (2) https://python-modernize.readthedocs.io/ (3) http://python-future.org/automatic_conversion.html  File: python.info, Node: Check which dependencies block your transition, Next: Update your setup py file to denote Python 3 compatibility, Prev: Prevent compatibility regressions, Up: Details 10.1.2.10 Check which dependencies block your transition ........................................................ `After' you have made your code compatible with Python 3 you should begin to care about whether your dependencies have also been ported. The caniusepython3(1) project was created to help you determine which projects – directly or indirectly – are blocking you from supporting Python 3. There is both a command-line tool as well as a web interface at ‘https://caniusepython3.com’. The project also provides code which you can integrate into your test suite so that you will have a failing test when you no longer have dependencies blocking you from using Python 3. This allows you to avoid having to manually check your dependencies and to be notified quickly when you can start running on Python 3. ---------- Footnotes ---------- (1) https://pypi.org/project/caniusepython3  File: python.info, Node: Update your setup py file to denote Python 3 compatibility, Next: Use continuous integration to stay compatible, Prev: Check which dependencies block your transition, Up: Details 10.1.2.11 Update your ‘setup.py’ file to denote Python 3 compatibility ...................................................................... Once your code works under Python 3, you should update the classifiers in your ‘setup.py’ to contain ‘Programming Language :: Python :: 3’ and to not specify sole Python 2 support. This will tell anyone using your code that you support Python 2 `and' 3. Ideally you will also want to add classifiers for each major/minor version of Python you now support.  File: python.info, Node: Use continuous integration to stay compatible, Next: Consider using optional static type checking, Prev: Update your setup py file to denote Python 3 compatibility, Up: Details 10.1.2.12 Use continuous integration to stay compatible ....................................................... Once you are able to fully run under Python 3 you will want to make sure your code always works under both Python 2 & 3. Probably the best tool for running your tests under multiple Python interpreters is tox(1). You can then integrate tox with your continuous integration system so that you never accidentally break Python 2 or 3 support. You may also want to use the ‘-bb’ flag with the Python 3 interpreter to trigger an exception when you are comparing bytes to strings or bytes to an int (the latter is available starting in Python 3.5). By default type-differing comparisons simply return ‘False’, but if you made a mistake in your separation of text/binary data handling or indexing on bytes you wouldn’t easily find the mistake. This flag will raise an exception when these kinds of comparisons occur, making the mistake much easier to track down. And that’s mostly it! At this point your code base is compatible with both Python 2 and 3 simultaneously. Your testing will also be set up so that you don’t accidentally break Python 2 or 3 compatibility regardless of which version you typically run your tests under while developing. ---------- Footnotes ---------- (1) https://pypi.org/project/tox  File: python.info, Node: Consider using optional static type checking, Prev: Use continuous integration to stay compatible, Up: Details 10.1.2.13 Consider using optional static type checking ...................................................... Another way to help port your code is to use a static type checker like mypy(1) or pytype(2) on your code. These tools can be used to analyze your code as if it’s being run under Python 2, then you can run the tool a second time as if your code is running under Python 3. By running a static type checker twice like this you can discover if you’re e.g. misusing binary data type in one version of Python compared to another. If you add optional type hints to your code you can also explicitly state whether your APIs use textual or binary data, helping to make sure everything functions as expected in both versions of Python. ---------- Footnotes ---------- (1) http://mypy-lang.org/ (2) https://github.com/google/pytype  File: python.info, Node: Porting Extension Modules to Python 3, Next: Curses Programming with Python, Prev: Porting Python 2 Code to Python 3, Up: Python HOWTOs 10.2 Porting Extension Modules to Python 3 ========================================== We recommend the following resources for porting extension modules to Python 3: * The Migrating C extensions(1) chapter from `Supporting Python 3: An in-depth guide', a book on moving from Python 2 to Python 3 in general, guides the reader through porting an extension module. * The Porting guide(2) from the `py3c' project provides opinionated suggestions with supporting code. * The Cython(3) and CFFI(4) libraries offer abstractions over Python’s C API. Extensions generally need to be re-written to use one of them, but the library then handles differences between various Python versions and implementations. ---------- Footnotes ---------- (1) http://python3porting.com/cextensions.html (2) https://py3c.readthedocs.io/en/latest/guide.html (3) http://cython.org/ (4) https://cffi.readthedocs.io/en/latest/  File: python.info, Node: Curses Programming with Python, Next: Descriptor HowTo Guide, Prev: Porting Extension Modules to Python 3, Up: Python HOWTOs 10.3 Curses Programming with Python =================================== Author: A.M. Kuchling, Eric S. Raymond Release: 2.04 Abstract ........ This document describes how to use the *note curses: 2c. extension module to control text-mode displays. * Menu: * What is curses?:: * Starting and ending a curses application:: * Windows and Pads:: * Displaying Text:: * User Input:: * For More Information::  File: python.info, Node: What is curses?, Next: Starting and ending a curses application, Up: Curses Programming with Python 10.3.1 What is curses? ---------------------- The curses library supplies a terminal-independent screen-painting and keyboard-handling facility for text-based terminals; such terminals include VT100s, the Linux console, and the simulated terminal provided by various programs. Display terminals support various control codes to perform common operations such as moving the cursor, scrolling the screen, and erasing areas. Different terminals use widely differing codes, and often have their own minor quirks. In a world of graphical displays, one might ask “why bother”? It’s true that character-cell display terminals are an obsolete technology, but there are niches in which being able to do fancy things with them are still valuable. One niche is on small-footprint or embedded Unixes that don’t run an X server. Another is tools such as OS installers and kernel configurators that may have to run before any graphical support is available. The curses library provides fairly basic functionality, providing the programmer with an abstraction of a display containing multiple non-overlapping windows of text. The contents of a window can be changed in various ways—adding text, erasing it, changing its appearance—and the curses library will figure out what control codes need to be sent to the terminal to produce the right output. curses doesn’t provide many user-interface concepts such as buttons, checkboxes, or dialogs; if you need such features, consider a user interface library such as Urwid(1). The curses library was originally written for BSD Unix; the later System V versions of Unix from AT&T added many enhancements and new functions. BSD curses is no longer maintained, having been replaced by ncurses, which is an open-source implementation of the AT&T interface. If you’re using an open-source Unix such as Linux or FreeBSD, your system almost certainly uses ncurses. Since most current commercial Unix versions are based on System V code, all the functions described here will probably be available. The older versions of curses carried by some proprietary Unixes may not support everything, though. The Windows version of Python doesn’t include the *note curses: 2c. module. A ported version called UniCurses(2) is available. You could also try the Console module(3) written by Fredrik Lundh, which doesn’t use the same API as curses but provides cursor-addressable text output and full support for mouse and keyboard input. * Menu: * The Python curses module:: ---------- Footnotes ---------- (1) https://pypi.org/project/urwid/ (2) https://pypi.org/project/UniCurses (3) http://effbot.org/zone/console-index.htm  File: python.info, Node: The Python curses module, Up: What is curses? 10.3.1.1 The Python curses module ................................. The Python module is a fairly simple wrapper over the C functions provided by curses; if you’re already familiar with curses programming in C, it’s really easy to transfer that knowledge to Python. The biggest difference is that the Python interface makes things simpler by merging different C functions such as ‘addstr()’, ‘mvaddstr()’, and ‘mvwaddstr()’ into a single *note addstr(): 1e42. method. You’ll see this covered in more detail later. This HOWTO is an introduction to writing text-mode programs with curses and Python. It doesn’t attempt to be a complete guide to the curses API; for that, see the Python library guide’s section on ncurses, and the C manual pages for ncurses. It will, however, give you the basic ideas.  File: python.info, Node: Starting and ending a curses application, Next: Windows and Pads, Prev: What is curses?, Up: Curses Programming with Python 10.3.2 Starting and ending a curses application ----------------------------------------------- Before doing anything, curses must be initialized. This is done by calling the *note initscr(): 1e48. function, which will determine the terminal type, send any required setup codes to the terminal, and create various internal data structures. If successful, ‘initscr()’ returns a window object representing the entire screen; this is usually called ‘stdscr’ after the name of the corresponding C variable. import curses stdscr = curses.initscr() Usually curses applications turn off automatic echoing of keys to the screen, in order to be able to read keys and only display them under certain circumstances. This requires calling the *note noecho(): 1e67. function. curses.noecho() Applications will also commonly need to react to keys instantly, without requiring the Enter key to be pressed; this is called cbreak mode, as opposed to the usual buffered input mode. curses.cbreak() Terminals usually return special keys, such as the cursor keys or navigation keys such as Page Up and Home, as a multibyte escape sequence. While you could write your application to expect such sequences and process them accordingly, curses can do it for you, returning a special value such as ‘curses.KEY_LEFT’. To get curses to do the job, you’ll have to enable keypad mode. stdscr.keypad(True) Terminating a curses application is much easier than starting one. You’ll need to call: curses.nocbreak() stdscr.keypad(False) curses.echo() to reverse the curses-friendly terminal settings. Then call the *note endwin(): 1e45. function to restore the terminal to its original operating mode. curses.endwin() A common problem when debugging a curses application is to get your terminal messed up when the application dies without restoring the terminal to its previous state. In Python this commonly happens when your code is buggy and raises an uncaught exception. Keys are no longer echoed to the screen when you type them, for example, which makes using the shell difficult. In Python you can avoid these complications and make debugging much easier by importing the *note curses.wrapper(): 2a1. function and using it like this: from curses import wrapper def main(stdscr): # Clear screen stdscr.clear() # This raises ZeroDivisionError when i == 10. for i in range(0, 11): v = i-10 stdscr.addstr(i, 0, '10 divided by {} is {}'.format(v, 10/v)) stdscr.refresh() stdscr.getkey() wrapper(main) The *note wrapper(): 2a1. function takes a callable object and does the initializations described above, also initializing colors if color support is present. ‘wrapper()’ then runs your provided callable. Once the callable returns, ‘wrapper()’ will restore the original state of the terminal. The callable is called inside a *note try: d72.…*note except: b3e. that catches exceptions, restores the state of the terminal, and then re-raises the exception. Therefore your terminal won’t be left in a funny state on exception and you’ll be able to read the exception’s message and traceback.  File: python.info, Node: Windows and Pads, Next: Displaying Text, Prev: Starting and ending a curses application, Up: Curses Programming with Python 10.3.3 Windows and Pads ----------------------- Windows are the basic abstraction in curses. A window object represents a rectangular area of the screen, and supports methods to display text, erase it, allow the user to input strings, and so forth. The ‘stdscr’ object returned by the *note initscr(): 1e48. function is a window object that covers the entire screen. Many programs may need only this single window, but you might wish to divide the screen into smaller windows, in order to redraw or clear them separately. The *note newwin(): 1e65. function creates a new window of a given size, returning the new window object. begin_x = 20; begin_y = 7 height = 5; width = 40 win = curses.newwin(height, width, begin_y, begin_x) Note that the coordinate system used in curses is unusual. Coordinates are always passed in the order `y,x', and the top-left corner of a window is coordinate (0,0). This breaks the normal convention for handling coordinates where the `x' coordinate comes first. This is an unfortunate difference from most other computer applications, but it’s been part of curses since it was first written, and it’s too late to change things now. Your application can determine the size of the screen by using the ‘curses.LINES’ and ‘curses.COLS’ variables to obtain the `y' and `x' sizes. Legal coordinates will then extend from ‘(0,0)’ to ‘(curses.LINES - 1, curses.COLS - 1)’. When you call a method to display or erase text, the effect doesn’t immediately show up on the display. Instead you must call the *note refresh(): 1e43. method of window objects to update the screen. This is because curses was originally written with slow 300-baud terminal connections in mind; with these terminals, minimizing the time required to redraw the screen was very important. Instead curses accumulates changes to the screen and displays them in the most efficient manner when you call ‘refresh()’. For example, if your program displays some text in a window and then clears the window, there’s no need to send the original text because they’re never visible. In practice, explicitly telling curses to redraw a window doesn’t really complicate programming with curses much. Most programs go into a flurry of activity, and then pause waiting for a keypress or some other action on the part of the user. All you have to do is to be sure that the screen has been redrawn before pausing to wait for user input, by first calling ‘stdscr.refresh()’ or the ‘refresh()’ method of some other relevant window. A pad is a special case of a window; it can be larger than the actual display screen, and only a portion of the pad displayed at a time. Creating a pad requires the pad’s height and width, while refreshing a pad requires giving the coordinates of the on-screen area where a subsection of the pad will be displayed. pad = curses.newpad(100, 100) # These loops fill the pad with letters; addch() is # explained in the next section for y in range(0, 99): for x in range(0, 99): pad.addch(y,x, ord('a') + (x*x+y*y) % 26) # Displays a section of the pad in the middle of the screen. # (0,0) : coordinate of upper-left corner of pad area to display. # (5,5) : coordinate of upper-left corner of window area to be filled # with pad content. # (20, 75) : coordinate of lower-right corner of window area to be # : filled with pad content. pad.refresh( 0,0, 5,5, 20,75) The ‘refresh()’ call displays a section of the pad in the rectangle extending from coordinate (5,5) to coordinate (20,75) on the screen; the upper left corner of the displayed section is coordinate (0,0) on the pad. Beyond that difference, pads are exactly like ordinary windows and support the same methods. If you have multiple windows and pads on screen there is a more efficient way to update the screen and prevent annoying screen flicker as each part of the screen gets updated. ‘refresh()’ actually does two things: 1. Calls the *note noutrefresh(): 1e41. method of each window to update an underlying data structure representing the desired state of the screen. 2. Calls the function *note doupdate(): 1e40. function to change the physical screen to match the desired state recorded in the data structure. Instead you can call ‘noutrefresh()’ on a number of windows to update the data structure, and then call ‘doupdate()’ to update the screen.  File: python.info, Node: Displaying Text, Next: User Input, Prev: Windows and Pads, Up: Curses Programming with Python 10.3.4 Displaying Text ---------------------- From a C programmer’s point of view, curses may sometimes look like a twisty maze of functions, all subtly different. For example, ‘addstr()’ displays a string at the current cursor location in the ‘stdscr’ window, while ‘mvaddstr()’ moves to a given y,x coordinate first before displaying the string. ‘waddstr()’ is just like ‘addstr()’, but allows specifying a window to use instead of using ‘stdscr’ by default. ‘mvwaddstr()’ allows specifying both a window and a coordinate. Fortunately the Python interface hides all these details. ‘stdscr’ is a window object like any other, and methods such as *note addstr(): 1e42. accept multiple argument forms. Usually there are four different forms. Form Description ------------------------------------------------------------------------------------------ `str' or `ch' Display the string `str' or character `ch' at the current position `str' or `ch', `attr' Display the string `str' or character `ch', using attribute `attr' at the current position `y', `x', `str' or `ch' Move to position `y,x' within the window, and display `str' or `ch' `y', `x', `str' or `ch', `attr' Move to position `y,x' within the window, and display `str' or `ch', using attribute `attr' Attributes allow displaying text in highlighted forms such as boldface, underline, reverse code, or in color. They’ll be explained in more detail in the next subsection. The *note addstr(): 1e42. method takes a Python string or bytestring as the value to be displayed. The contents of bytestrings are sent to the terminal as-is. Strings are encoded to bytes using the value of the window’s ‘encoding’ attribute; this defaults to the default system encoding as returned by *note locale.getpreferredencoding(): 3a5. The *note addch(): 1e80. methods take a character, which can be either a string of length 1, a bytestring of length 1, or an integer. Constants are provided for extension characters; these constants are integers greater than 255. For example, ‘ACS_PLMINUS’ is a +/- symbol, and ‘ACS_ULCORNER’ is the upper left corner of a box (handy for drawing borders). You can also use the appropriate Unicode character. Windows remember where the cursor was left after the last operation, so if you leave out the `y,x' coordinates, the string or character will be displayed wherever the last operation left off. You can also move the cursor with the ‘move(y,x)’ method. Because some terminals always display a flashing cursor, you may want to ensure that the cursor is positioned in some location where it won’t be distracting; it can be confusing to have the cursor blinking at some apparently random location. If your application doesn’t need a blinking cursor at all, you can call ‘curs_set(False)’ to make it invisible. For compatibility with older curses versions, there’s a ‘leaveok(bool)’ function that’s a synonym for *note curs_set(): 1e3a. When `bool' is true, the curses library will attempt to suppress the flashing cursor, and you won’t need to worry about leaving it in odd locations. * Menu: * Attributes and Color::  File: python.info, Node: Attributes and Color, Up: Displaying Text 10.3.4.1 Attributes and Color ............................. Characters can be displayed in different ways. Status lines in a text-based application are commonly shown in reverse video, or a text viewer may need to highlight certain words. curses supports this by allowing you to specify an attribute for each cell on the screen. An attribute is an integer, each bit representing a different attribute. You can try to display text with multiple attribute bits set, but curses doesn’t guarantee that all the possible combinations are available, or that they’re all visually distinct. That depends on the ability of the terminal being used, so it’s safest to stick to the most commonly available attributes, listed here. Attribute Description ---------------------------------------------------------------------- ‘A_BLINK’ Blinking text ‘A_BOLD’ Extra bright or bold text ‘A_DIM’ Half bright text ‘A_REVERSE’ Reverse-video text ‘A_STANDOUT’ The best highlighting mode available ‘A_UNDERLINE’ Underlined text So, to display a reverse-video status line on the top line of the screen, you could code: stdscr.addstr(0, 0, "Current mode: Typing mode", curses.A_REVERSE) stdscr.refresh() The curses library also supports color on those terminals that provide it. The most common such terminal is probably the Linux console, followed by color xterms. To use color, you must call the *note start_color(): 1e73. function soon after calling *note initscr(): 1e48, to initialize the default color set (the *note curses.wrapper(): 2a1. function does this automatically). Once that’s done, the *note has_colors(): 1e50. function returns TRUE if the terminal in use can actually display color. (Note: curses uses the American spelling ‘color’, instead of the Canadian/British spelling ‘colour’. If you’re used to the British spelling, you’ll have to resign yourself to misspelling it for the sake of these functions.) The curses library maintains a finite number of color pairs, containing a foreground (or text) color and a background color. You can get the attribute value corresponding to a color pair with the *note color_pair(): 1e38. function; this can be bitwise-OR’ed with other attributes such as ‘A_REVERSE’, but again, such combinations are not guaranteed to work on all terminals. An example, which displays a line of text using color pair 1: stdscr.addstr("Pretty text", curses.color_pair(1)) stdscr.refresh() As I said before, a color pair consists of a foreground and background color. The ‘init_pair(n, f, b)’ function changes the definition of color pair `n', to foreground color f and background color b. Color pair 0 is hard-wired to white on black, and cannot be changed. Colors are numbered, and ‘start_color()’ initializes 8 basic colors when it activates color mode. They are: 0:black, 1:red, 2:green, 3:yellow, 4:blue, 5:magenta, 6:cyan, and 7:white. The *note curses: 2c. module defines named constants for each of these colors: ‘curses.COLOR_BLACK’, ‘curses.COLOR_RED’, and so forth. Let’s put all this together. To change color 1 to red text on a white background, you would call: curses.init_pair(1, curses.COLOR_RED, curses.COLOR_WHITE) When you change a color pair, any text already displayed using that color pair will change to the new colors. You can also display new text in this color with: stdscr.addstr(0,0, "RED ALERT!", curses.color_pair(1)) Very fancy terminals can change the definitions of the actual colors to a given RGB value. This lets you change color 1, which is usually red, to purple or blue or any other color you like. Unfortunately, the Linux console doesn’t support this, so I’m unable to try it out, and can’t provide any examples. You can check if your terminal can do this by calling *note can_change_color(): 1e34, which returns ‘True’ if the capability is there. If you’re lucky enough to have such a talented terminal, consult your system’s man pages for more information.  File: python.info, Node: User Input, Next: For More Information, Prev: Displaying Text, Up: Curses Programming with Python 10.3.5 User Input ----------------- The C curses library offers only very simple input mechanisms. Python’s *note curses: 2c. module adds a basic text-input widget. (Other libraries such as Urwid(1) have more extensive collections of widgets.) There are two methods for getting input from a window: * *note getch(): 1e4c. refreshes the screen and then waits for the user to hit a key, displaying the key if *note echo(): 1e44. has been called earlier. You can optionally specify a coordinate to which the cursor should be moved before pausing. * *note getkey(): 1e99. does the same thing but converts the integer to a string. Individual characters are returned as 1-character strings, and special keys such as function keys return longer strings containing a key name such as ‘KEY_UP’ or ‘^G’. It’s possible to not wait for the user using the *note nodelay(): 1eaf. window method. After ‘nodelay(True)’, ‘getch()’ and ‘getkey()’ for the window become non-blocking. To signal that no input is ready, ‘getch()’ returns ‘curses.ERR’ (a value of -1) and ‘getkey()’ raises an exception. There’s also a *note halfdelay(): 1e54. function, which can be used to (in effect) set a timer on each ‘getch()’; if no input becomes available within a specified delay (measured in tenths of a second), curses raises an exception. The ‘getch()’ method returns an integer; if it’s between 0 and 255, it represents the ASCII code of the key pressed. Values greater than 255 are special keys such as Page Up, Home, or the cursor keys. You can compare the value returned to constants such as ‘curses.KEY_PPAGE’, ‘curses.KEY_HOME’, or ‘curses.KEY_LEFT’. The main loop of your program may look something like this: while True: c = stdscr.getch() if c == ord('p'): PrintDocument() elif c == ord('q'): break # Exit the while loop elif c == curses.KEY_HOME: x = y = 0 The *note curses.ascii: 2d. module supplies ASCII class membership functions that take either integer or 1-character string arguments; these may be useful in writing more readable tests for such loops. It also supplies conversion functions that take either integer or 1-character-string arguments and return the same type. For example, *note curses.ascii.ctrl(): 1ee3. returns the control character corresponding to its argument. There’s also a method to retrieve an entire string, *note getstr(): 1e9c. It isn’t used very often, because its functionality is quite limited; the only editing keys available are the backspace key and the Enter key, which terminates the string. It can optionally be limited to a fixed number of characters. curses.echo() # Enable echoing of characters # Get a 15-character string, with the cursor on the top line s = stdscr.getstr(0,0, 15) The *note curses.textpad: 2f. module supplies a text box that supports an Emacs-like set of keybindings. Various methods of the *note Textbox: 1ec9. class support editing with input validation and gathering the edit results either with or without trailing spaces. Here’s an example: import curses from curses.textpad import Textbox, rectangle def main(stdscr): stdscr.addstr(0, 0, "Enter IM message: (hit Ctrl-G to send)") editwin = curses.newwin(5,30, 2,1) rectangle(stdscr, 1,0, 1+5+1, 1+30+1) stdscr.refresh() box = Textbox(editwin) # Let the user edit until Ctrl-G is struck. box.edit() # Get resulting contents message = box.gather() See the library documentation on *note curses.textpad: 2f. for more details. ---------- Footnotes ---------- (1) https://pypi.org/project/urwid/  File: python.info, Node: For More Information, Prev: User Input, Up: Curses Programming with Python 10.3.6 For More Information --------------------------- This HOWTO doesn’t cover some advanced topics, such as reading the contents of the screen or capturing mouse events from an xterm instance, but the Python library page for the *note curses: 2c. module is now reasonably complete. You should browse it next. If you’re in doubt about the detailed behavior of the curses functions, consult the manual pages for your curses implementation, whether it’s ncurses or a proprietary Unix vendor’s. The manual pages will document any quirks, and provide complete lists of all the functions, attributes, and ‘ACS_*’ characters available to you. Because the curses API is so large, some functions aren’t supported in the Python interface. Often this isn’t because they’re difficult to implement, but because no one has needed them yet. Also, Python doesn’t yet support the menu library associated with ncurses. Patches adding support for these would be welcome; see the Python Developer’s Guide(1) to learn more about submitting patches to Python. * Writing Programs with NCURSES(2): a lengthy tutorial for C programmers. * The ncurses man page(3) * The ncurses FAQ(4) * "Use curses... don’t swear"(5): video of a PyCon 2013 talk on controlling terminals using curses or Urwid. * "Console Applications with Urwid"(6): video of a PyCon CA 2012 talk demonstrating some applications written using Urwid. ---------- Footnotes ---------- (1) https://devguide.python.org/ (2) http://invisible-island.net/ncurses/ncurses-intro.html (3) https://linux.die.net/man/3/ncurses (4) http://invisible-island.net/ncurses/ncurses.faq.html (5) https://www.youtube.com/watch?v=eN1eZtjLEnU (6) http://www.pyvideo.org/video/1568/console-applications-with-urwid  File: python.info, Node: Descriptor HowTo Guide, Next: Functional Programming HOWTO, Prev: Curses Programming with Python, Up: Python HOWTOs 10.4 Descriptor HowTo Guide =========================== Author: Raymond Hettinger Contact: <python at rcn dot com> * Menu: * Abstract:: * Definition and Introduction:: * Descriptor Protocol:: * Invoking Descriptors: Invoking Descriptors<2>. * Descriptor Example:: * Properties:: * Functions and Methods:: * Static Methods and Class Methods::  File: python.info, Node: Abstract, Next: Definition and Introduction, Up: Descriptor HowTo Guide 10.4.1 Abstract --------------- Defines descriptors, summarizes the protocol, and shows how descriptors are called. Examines a custom descriptor and several built-in Python descriptors including functions, properties, static methods, and class methods. Shows how each works by giving a pure Python equivalent and a sample application. Learning about descriptors not only provides access to a larger toolset, it creates a deeper understanding of how Python works and an appreciation for the elegance of its design.  File: python.info, Node: Definition and Introduction, Next: Descriptor Protocol, Prev: Abstract, Up: Descriptor HowTo Guide 10.4.2 Definition and Introduction ---------------------------------- In general, a descriptor is an object attribute with “binding behavior”, one whose attribute access has been overridden by methods in the descriptor protocol. Those methods are *note __get__(): 10dd, *note __set__(): 10e1, and *note __delete__(): 10e2. If any of those methods are defined for an object, it is said to be a descriptor. The default behavior for attribute access is to get, set, or delete the attribute from an object’s dictionary. For instance, ‘a.x’ has a lookup chain starting with ‘a.__dict__['x']’, then ‘type(a).__dict__['x']’, and continuing through the base classes of ‘type(a)’ excluding metaclasses. If the looked-up value is an object defining one of the descriptor methods, then Python may override the default behavior and invoke the descriptor method instead. Where this occurs in the precedence chain depends on which descriptor methods were defined. Descriptors are a powerful, general purpose protocol. They are the mechanism behind properties, methods, static methods, class methods, and *note super(): 4e2. They are used throughout Python itself to implement the new style classes introduced in version 2.2. Descriptors simplify the underlying C-code and offer a flexible set of new tools for everyday Python programs.  File: python.info, Node: Descriptor Protocol, Next: Invoking Descriptors<2>, Prev: Definition and Introduction, Up: Descriptor HowTo Guide 10.4.3 Descriptor Protocol -------------------------- ‘descr.__get__(self, obj, type=None) -> value’ ‘descr.__set__(self, obj, value) -> None’ ‘descr.__delete__(self, obj) -> None’ That is all there is to it. Define any of these methods and an object is considered a descriptor and can override default behavior upon being looked up as an attribute. If an object defines *note __set__(): 10e1. or *note __delete__(): 10e2, it is considered a data descriptor. Descriptors that only define *note __get__(): 10dd. are called non-data descriptors (they are typically used for methods but other uses are possible). Data and non-data descriptors differ in how overrides are calculated with respect to entries in an instance’s dictionary. If an instance’s dictionary has an entry with the same name as a data descriptor, the data descriptor takes precedence. If an instance’s dictionary has an entry with the same name as a non-data descriptor, the dictionary entry takes precedence. To make a read-only data descriptor, define both *note __get__(): 10dd. and *note __set__(): 10e1. with the *note __set__(): 10e1. raising an *note AttributeError: 39b. when called. Defining the *note __set__(): 10e1. method with an exception raising placeholder is enough to make it a data descriptor.  File: python.info, Node: Invoking Descriptors<2>, Next: Descriptor Example, Prev: Descriptor Protocol, Up: Descriptor HowTo Guide 10.4.4 Invoking Descriptors --------------------------- A descriptor can be called directly by its method name. For example, ‘d.__get__(obj)’. Alternatively, it is more common for a descriptor to be invoked automatically upon attribute access. For example, ‘obj.d’ looks up ‘d’ in the dictionary of ‘obj’. If ‘d’ defines the method *note __get__(): 10dd, then ‘d.__get__(obj)’ is invoked according to the precedence rules listed below. The details of invocation depend on whether ‘obj’ is an object or a class. For objects, the machinery is in *note object.__getattribute__(): 449. which transforms ‘b.x’ into ‘type(b).__dict__['x'].__get__(b, type(b))’. The implementation works through a precedence chain that gives data descriptors priority over instance variables, instance variables priority over non-data descriptors, and assigns lowest priority to *note __getattr__(): 31a. if provided. The full C implementation can be found in *note PyObject_GenericGetAttr(): 3a02. in Objects/object.c(1). For classes, the machinery is in ‘type.__getattribute__()’ which transforms ‘B.x’ into ‘B.__dict__['x'].__get__(None, B)’. In pure Python, it looks like: def __getattribute__(self, key): "Emulate type_getattro() in Objects/typeobject.c" v = object.__getattribute__(self, key) if hasattr(v, '__get__'): return v.__get__(None, self) return v The important points to remember are: * descriptors are invoked by the *note __getattribute__(): 449. method * overriding *note __getattribute__(): 449. prevents automatic descriptor calls * *note object.__getattribute__(): 449. and ‘type.__getattribute__()’ make different calls to *note __get__(): 10dd. * data descriptors always override instance dictionaries. * non-data descriptors may be overridden by instance dictionaries. The object returned by ‘super()’ also has a custom *note __getattribute__(): 449. method for invoking descriptors. The attribute lookup ‘super(B, obj).m’ searches ‘obj.__class__.__mro__’ for the base class ‘A’ immediately following ‘B’ and then returns ‘A.__dict__['m'].__get__(obj, B)’. If not a descriptor, ‘m’ is returned unchanged. If not in the dictionary, ‘m’ reverts to a search using *note object.__getattribute__(): 449. The implementation details are in ‘super_getattro()’ in Objects/typeobject.c(2). and a pure Python equivalent can be found in Guido’s Tutorial(3). The details above show that the mechanism for descriptors is embedded in the *note __getattribute__(): 449. methods for *note object: 2b0, *note type: 608, and *note super(): 4e2. Classes inherit this machinery when they derive from *note object: 2b0. or if they have a meta-class providing similar functionality. Likewise, classes can turn-off descriptor invocation by overriding *note __getattribute__(): 449. ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Objects/object.c (2) https://github.com/python/cpython/tree/3.8/Objects/typeobject.c (3) https://www.python.org/download/releases/2.2.3/descrintro/#cooperation  File: python.info, Node: Descriptor Example, Next: Properties, Prev: Invoking Descriptors<2>, Up: Descriptor HowTo Guide 10.4.5 Descriptor Example ------------------------- The following code creates a class whose objects are data descriptors which print a message for each get or set. Overriding *note __getattribute__(): 449. is alternate approach that could do this for every attribute. However, this descriptor is useful for monitoring just a few chosen attributes: class RevealAccess(object): """A data descriptor that sets and returns values normally and prints a message logging their access. """ def __init__(self, initval=None, name='var'): self.val = initval self.name = name def __get__(self, obj, objtype): print('Retrieving', self.name) return self.val def __set__(self, obj, val): print('Updating', self.name) self.val = val >>> class MyClass(object): ... x = RevealAccess(10, 'var "x"') ... y = 5 ... >>> m = MyClass() >>> m.x Retrieving var "x" 10 >>> m.x = 20 Updating var "x" >>> m.x Retrieving var "x" 20 >>> m.y 5 The protocol is simple and offers exciting possibilities. Several use cases are so common that they have been packaged into individual function calls. Properties, bound methods, static methods, and class methods are all based on the descriptor protocol.  File: python.info, Node: Properties, Next: Functions and Methods, Prev: Descriptor Example, Up: Descriptor HowTo Guide 10.4.6 Properties ----------------- Calling *note property(): 1d7. is a succinct way of building a data descriptor that triggers function calls upon access to an attribute. Its signature is: property(fget=None, fset=None, fdel=None, doc=None) -> property attribute The documentation shows a typical use to define a managed attribute ‘x’: class C(object): def getx(self): return self.__x def setx(self, value): self.__x = value def delx(self): del self.__x x = property(getx, setx, delx, "I'm the 'x' property.") To see how *note property(): 1d7. is implemented in terms of the descriptor protocol, here is a pure Python equivalent: class Property(object): "Emulate PyProperty_Type() in Objects/descrobject.c" def __init__(self, fget=None, fset=None, fdel=None, doc=None): self.fget = fget self.fset = fset self.fdel = fdel if doc is None and fget is not None: doc = fget.__doc__ self.__doc__ = doc def __get__(self, obj, objtype=None): if obj is None: return self if self.fget is None: raise AttributeError("unreadable attribute") return self.fget(obj) def __set__(self, obj, value): if self.fset is None: raise AttributeError("can't set attribute") self.fset(obj, value) def __delete__(self, obj): if self.fdel is None: raise AttributeError("can't delete attribute") self.fdel(obj) def getter(self, fget): return type(self)(fget, self.fset, self.fdel, self.__doc__) def setter(self, fset): return type(self)(self.fget, fset, self.fdel, self.__doc__) def deleter(self, fdel): return type(self)(self.fget, self.fset, fdel, self.__doc__) The *note property(): 1d7. builtin helps whenever a user interface has granted attribute access and then subsequent changes require the intervention of a method. For instance, a spreadsheet class may grant access to a cell value through ‘Cell('b10').value’. Subsequent improvements to the program require the cell to be recalculated on every access; however, the programmer does not want to affect existing client code accessing the attribute directly. The solution is to wrap access to the value attribute in a property data descriptor: class Cell(object): . . . def getvalue(self): "Recalculate the cell before returning value" self.recalc() return self._value value = property(getvalue)  File: python.info, Node: Functions and Methods, Next: Static Methods and Class Methods, Prev: Properties, Up: Descriptor HowTo Guide 10.4.7 Functions and Methods ---------------------------- Python’s object oriented features are built upon a function based environment. Using non-data descriptors, the two are merged seamlessly. Class dictionaries store methods as functions. In a class definition, methods are written using *note def: dbe. or *note lambda: c2f, the usual tools for creating functions. Methods only differ from regular functions in that the first argument is reserved for the object instance. By Python convention, the instance reference is called `self' but may be called `this' or any other variable name. To support method calls, functions include the *note __get__(): 10dd. method for binding methods during attribute access. This means that all functions are non-data descriptors which return bound methods when they are invoked from an object. In pure Python, it works like this: class Function(object): . . . def __get__(self, obj, objtype=None): "Simulate func_descr_get() in Objects/funcobject.c" if obj is None: return self return types.MethodType(self, obj) Running the interpreter shows how the function descriptor works in practice: >>> class D(object): ... def f(self, x): ... return x ... >>> d = D() # Access through the class dictionary does not invoke __get__. # It just returns the underlying function object. >>> D.__dict__['f'] <function D.f at 0x00C45070> # Dotted access from a class calls __get__() which just returns # the underlying function unchanged. >>> D.f <function D.f at 0x00C45070> # The function has a __qualname__ attribute to support introspection >>> D.f.__qualname__ 'D.f' # Dotted access from an instance calls __get__() which returns the # function wrapped in a bound method object >>> d.f <bound method D.f of <__main__.D object at 0x00B18C90>> # Internally, the bound method stores the underlying function and # the bound instance. >>> d.f.__func__ <function D.f at 0x1012e5ae8> >>> d.f.__self__ <__main__.D object at 0x1012e1f98>  File: python.info, Node: Static Methods and Class Methods, Prev: Functions and Methods, Up: Descriptor HowTo Guide 10.4.8 Static Methods and Class Methods --------------------------------------- Non-data descriptors provide a simple mechanism for variations on the usual patterns of binding functions into methods. To recap, functions have a *note __get__(): 10dd. method so that they can be converted to a method when accessed as attributes. The non-data descriptor transforms an ‘obj.f(*args)’ call into ‘f(obj, *args)’. Calling ‘klass.f(*args)’ becomes ‘f(*args)’. This chart summarizes the binding and its two most useful variants: Transformation Called from an Object Called from a Class ------------------------------------------------------------------------ function f(obj, *args) f(*args) staticmethod f(*args) f(*args) classmethod f(type(obj), *args) f(klass, *args) Static methods return the underlying function without changes. Calling either ‘c.f’ or ‘C.f’ is the equivalent of a direct lookup into ‘object.__getattribute__(c, "f")’ or ‘object.__getattribute__(C, "f")’. As a result, the function becomes identically accessible from either an object or a class. Good candidates for static methods are methods that do not reference the ‘self’ variable. For instance, a statistics package may include a container class for experimental data. The class provides normal methods for computing the average, mean, median, and other descriptive statistics that depend on the data. However, there may be useful functions which are conceptually related but do not depend on the data. For instance, ‘erf(x)’ is handy conversion routine that comes up in statistical work but does not directly depend on a particular dataset. It can be called either from an object or the class: ‘s.erf(1.5) --> .9332’ or ‘Sample.erf(1.5) --> .9332’. Since staticmethods return the underlying function with no changes, the example calls are unexciting: >>> class E(object): ... def f(x): ... print(x) ... f = staticmethod(f) ... >>> E.f(3) 3 >>> E().f(3) 3 Using the non-data descriptor protocol, a pure Python version of *note staticmethod(): 1d9. would look like this: class StaticMethod(object): "Emulate PyStaticMethod_Type() in Objects/funcobject.c" def __init__(self, f): self.f = f def __get__(self, obj, objtype=None): return self.f Unlike static methods, class methods prepend the class reference to the argument list before calling the function. This format is the same for whether the caller is an object or a class: >>> class E(object): ... def f(klass, x): ... return klass.__name__, x ... f = classmethod(f) ... >>> print(E.f(3)) ('E', 3) >>> print(E().f(3)) ('E', 3) This behavior is useful whenever the function only needs to have a class reference and does not care about any underlying data. One use for classmethods is to create alternate class constructors. In Python 2.3, the classmethod *note dict.fromkeys(): 137f. creates a new dictionary from a list of keys. The pure Python equivalent is: class Dict(object): . . . def fromkeys(klass, iterable, value=None): "Emulate dict_fromkeys() in Objects/dictobject.c" d = klass() for key in iterable: d[key] = value return d fromkeys = classmethod(fromkeys) Now a new dictionary of unique keys can be constructed like this: >>> Dict.fromkeys('abracadabra') {'a': None, 'r': None, 'b': None, 'c': None, 'd': None} Using the non-data descriptor protocol, a pure Python version of *note classmethod(): 1d8. would look like this: class ClassMethod(object): "Emulate PyClassMethod_Type() in Objects/funcobject.c" def __init__(self, f): self.f = f def __get__(self, obj, klass=None): if klass is None: klass = type(obj) def newfunc(*args): return self.f(klass, *args) return newfunc  File: python.info, Node: Functional Programming HOWTO, Next: Logging HOWTO, Prev: Descriptor HowTo Guide, Up: Python HOWTOs 10.5 Functional Programming HOWTO ================================= Author: A. M. Kuchling Release: 0.32 In this document, we’ll take a tour of Python’s features suitable for implementing programs in a functional style. After an introduction to the concepts of functional programming, we’ll look at language features such as *note iterator: 112e.s and *note generator: 9a2.s and relevant library modules such as *note itertools: a3. and *note functools: 85. * Menu: * Introduction: Introduction<14>. * Iterators: Iterators<2>. * Generator expressions and list comprehensions:: * Generators: Generators<2>. * Built-in functions:: * The itertools module:: * The functools module:: * Small functions and the lambda expression:: * Revision History and Acknowledgements:: * References: References<2>.  File: python.info, Node: Introduction<14>, Next: Iterators<2>, Up: Functional Programming HOWTO 10.5.1 Introduction ------------------- This section explains the basic concept of functional programming; if you’re just interested in learning about Python language features, skip to the next section on *note Iterators: 3e89. Programming languages support decomposing problems in several different ways: * Most programming languages are `procedural': programs are lists of instructions that tell the computer what to do with the program’s input. C, Pascal, and even Unix shells are procedural languages. * In `declarative' languages, you write a specification that describes the problem to be solved, and the language implementation figures out how to perform the computation efficiently. SQL is the declarative language you’re most likely to be familiar with; a SQL query describes the data set you want to retrieve, and the SQL engine decides whether to scan tables or use indexes, which subclauses should be performed first, etc. * `Object-oriented' programs manipulate collections of objects. Objects have internal state and support methods that query or modify this internal state in some way. Smalltalk and Java are object-oriented languages. C++ and Python are languages that support object-oriented programming, but don’t force the use of object-oriented features. * `Functional' programming decomposes a problem into a set of functions. Ideally, functions only take inputs and produce outputs, and don’t have any internal state that affects the output produced for a given input. Well-known functional languages include the ML family (Standard ML, OCaml, and other variants) and Haskell. The designers of some computer languages choose to emphasize one particular approach to programming. This often makes it difficult to write programs that use a different approach. Other languages are multi-paradigm languages that support several different approaches. Lisp, C++, and Python are multi-paradigm; you can write programs or libraries that are largely procedural, object-oriented, or functional in all of these languages. In a large program, different sections might be written using different approaches; the GUI might be object-oriented while the processing logic is procedural or functional, for example. In a functional program, input flows through a set of functions. Each function operates on its input and produces some output. Functional style discourages functions with side effects that modify internal state or make other changes that aren’t visible in the function’s return value. Functions that have no side effects at all are called `purely functional'. Avoiding side effects means not using data structures that get updated as a program runs; every function’s output must only depend on its input. Some languages are very strict about purity and don’t even have assignment statements such as ‘a=3’ or ‘c = a + b’, but it’s difficult to avoid all side effects. Printing to the screen or writing to a disk file are side effects, for example. For example, in Python a call to the *note print(): 886. or *note time.sleep(): 680. function both return no useful value; they’re only called for their side effects of sending some text to the screen or pausing execution for a second. Python programs written in functional style usually won’t go to the extreme of avoiding all I/O or all assignments; instead, they’ll provide a functional-appearing interface but will use non-functional features internally. For example, the implementation of a function will still use assignments to local variables, but won’t modify global variables or have other side effects. Functional programming can be considered the opposite of object-oriented programming. Objects are little capsules containing some internal state along with a collection of method calls that let you modify this state, and programs consist of making the right set of state changes. Functional programming wants to avoid state changes as much as possible and works with data flowing between functions. In Python you might combine the two approaches by writing functions that take and return instances representing objects in your application (e-mail messages, transactions, etc.). Functional design may seem like an odd constraint to work under. Why should you avoid objects and side effects? There are theoretical and practical advantages to the functional style: * Formal provability. * Modularity. * Composability. * Ease of debugging and testing. * Menu: * Formal provability:: * Modularity:: * Ease of debugging and testing:: * Composability::  File: python.info, Node: Formal provability, Next: Modularity, Up: Introduction<14> 10.5.1.1 Formal provability ........................... A theoretical benefit is that it’s easier to construct a mathematical proof that a functional program is correct. For a long time researchers have been interested in finding ways to mathematically prove programs correct. This is different from testing a program on numerous inputs and concluding that its output is usually correct, or reading a program’s source code and concluding that the code looks right; the goal is instead a rigorous proof that a program produces the right result for all possible inputs. The technique used to prove programs correct is to write down `invariants', properties of the input data and of the program’s variables that are always true. For each line of code, you then show that if invariants X and Y are true `before' the line is executed, the slightly different invariants X’ and Y’ are true `after' the line is executed. This continues until you reach the end of the program, at which point the invariants should match the desired conditions on the program’s output. Functional programming’s avoidance of assignments arose because assignments are difficult to handle with this technique; assignments can break invariants that were true before the assignment without producing any new invariants that can be propagated onward. Unfortunately, proving programs correct is largely impractical and not relevant to Python software. Even trivial programs require proofs that are several pages long; the proof of correctness for a moderately complicated program would be enormous, and few or none of the programs you use daily (the Python interpreter, your XML parser, your web browser) could be proven correct. Even if you wrote down or generated a proof, there would then be the question of verifying the proof; maybe there’s an error in it, and you wrongly believe you’ve proved the program correct.  File: python.info, Node: Modularity, Next: Ease of debugging and testing, Prev: Formal provability, Up: Introduction<14> 10.5.1.2 Modularity ................... A more practical benefit of functional programming is that it forces you to break apart your problem into small pieces. Programs are more modular as a result. It’s easier to specify and write a small function that does one thing than a large function that performs a complicated transformation. Small functions are also easier to read and to check for errors.  File: python.info, Node: Ease of debugging and testing, Next: Composability, Prev: Modularity, Up: Introduction<14> 10.5.1.3 Ease of debugging and testing ...................................... Testing and debugging a functional-style program is easier. Debugging is simplified because functions are generally small and clearly specified. When a program doesn’t work, each function is an interface point where you can check that the data are correct. You can look at the intermediate inputs and outputs to quickly isolate the function that’s responsible for a bug. Testing is easier because each function is a potential subject for a unit test. Functions don’t depend on system state that needs to be replicated before running a test; instead you only have to synthesize the right input and then check that the output matches expectations.  File: python.info, Node: Composability, Prev: Ease of debugging and testing, Up: Introduction<14> 10.5.1.4 Composability ...................... As you work on a functional-style program, you’ll write a number of functions with varying inputs and outputs. Some of these functions will be unavoidably specialized to a particular application, but others will be useful in a wide variety of programs. For example, a function that takes a directory path and returns all the XML files in the directory, or a function that takes a filename and returns its contents, can be applied to many different situations. Over time you’ll form a personal library of utilities. Often you’ll assemble new programs by arranging existing functions in a new configuration and writing a few functions specialized for the current task.  File: python.info, Node: Iterators<2>, Next: Generator expressions and list comprehensions, Prev: Introduction<14>, Up: Functional Programming HOWTO 10.5.2 Iterators ---------------- I’ll start by looking at a Python language feature that’s an important foundation for writing functional-style programs: iterators. An iterator is an object representing a stream of data; this object returns the data one element at a time. A Python iterator must support a method called *note __next__(): c64. that takes no arguments and always returns the next element of the stream. If there are no more elements in the stream, *note __next__(): c64. must raise the *note StopIteration: 486. exception. Iterators don’t have to be finite, though; it’s perfectly reasonable to write an iterator that produces an infinite stream of data. The built-in *note iter(): d27. function takes an arbitrary object and tries to return an iterator that will return the object’s contents or elements, raising *note TypeError: 192. if the object doesn’t support iteration. Several of Python’s built-in data types support iteration, the most common being lists and dictionaries. An object is called *note iterable: bac. if you can get an iterator for it. You can experiment with the iteration interface manually: >>> L = [1, 2, 3] >>> it = iter(L) >>> it <...iterator object at ...> >>> it.__next__() # same as next(it) 1 >>> next(it) 2 >>> next(it) 3 >>> next(it) Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration >>> Python expects iterable objects in several different contexts, the most important being the *note for: c30. statement. In the statement ‘for X in Y’, Y must be an iterator or some object for which *note iter(): d27. can create an iterator. These two statements are equivalent: for i in iter(obj): print(i) for i in obj: print(i) Iterators can be materialized as lists or tuples by using the *note list(): 262. or *note tuple(): 47e. constructor functions: >>> L = [1, 2, 3] >>> iterator = iter(L) >>> t = tuple(iterator) >>> t (1, 2, 3) Sequence unpacking also supports iterators: if you know an iterator will return N elements, you can unpack them into an N-tuple: >>> L = [1, 2, 3] >>> iterator = iter(L) >>> a, b, c = iterator >>> a, b, c (1, 2, 3) Built-in functions such as *note max(): 80a. and *note min(): 809. can take a single iterator argument and will return the largest or smallest element. The ‘"in"’ and ‘"not in"’ operators also support iterators: ‘X in iterator’ is true if X is found in the stream returned by the iterator. You’ll run into obvious problems if the iterator is infinite; *note max(): 80a, *note min(): 809. will never return, and if the element X never appears in the stream, the ‘"in"’ and ‘"not in"’ operators won’t return either. Note that you can only go forward in an iterator; there’s no way to get the previous element, reset the iterator, or make a copy of it. Iterator objects can optionally provide these additional capabilities, but the iterator protocol only specifies the *note __next__(): c64. method. Functions may therefore consume all of the iterator’s output, and if you need to do something different with the same stream, you’ll have to create a new iterator. * Menu: * Data Types That Support Iterators::  File: python.info, Node: Data Types That Support Iterators, Up: Iterators<2> 10.5.2.1 Data Types That Support Iterators .......................................... We’ve already seen how lists and tuples support iterators. In fact, any Python sequence type, such as strings, will automatically support creation of an iterator. Calling *note iter(): d27. on a dictionary returns an iterator that will loop over the dictionary’s keys: >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6, ... 'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12} >>> for key in m: ... print(key, m[key]) Jan 1 Feb 2 Mar 3 Apr 4 May 5 Jun 6 Jul 7 Aug 8 Sep 9 Oct 10 Nov 11 Dec 12 Note that starting with Python 3.7, dictionary iteration order is guaranteed to be the same as the insertion order. In earlier versions, the behaviour was unspecified and could vary between implementations. Applying *note iter(): d27. to a dictionary always loops over the keys, but dictionaries have methods that return other iterators. If you want to iterate over values or key/value pairs, you can explicitly call the *note values(): c2c. or *note items(): c2b. methods to get an appropriate iterator. The *note dict(): 1b8. constructor can accept an iterator that returns a finite stream of ‘(key, value)’ tuples: >>> L = [('Italy', 'Rome'), ('France', 'Paris'), ('US', 'Washington DC')] >>> dict(iter(L)) {'Italy': 'Rome', 'France': 'Paris', 'US': 'Washington DC'} Files also support iteration by calling the *note readline(): 18b9. method until there are no more lines in the file. This means you can read each line of a file like this: for line in file: # do something for each line ... Sets can take their contents from an iterable and let you iterate over the set’s elements: S = {2, 3, 5, 7, 11, 13} for i in S: print(i)  File: python.info, Node: Generator expressions and list comprehensions, Next: Generators<2>, Prev: Iterators<2>, Up: Functional Programming HOWTO 10.5.3 Generator expressions and list comprehensions ---------------------------------------------------- Two common operations on an iterator’s output are 1) performing some operation for every element, 2) selecting a subset of elements that meet some condition. For example, given a list of strings, you might want to strip off trailing whitespace from each line or extract all the strings containing a given substring. List comprehensions and generator expressions (short form: “listcomps” and “genexps”) are a concise notation for such operations, borrowed from the functional programming language Haskell (‘https://www.haskell.org/’). You can strip all the whitespace from a stream of strings with the following code: line_list = [' line 1\n', 'line 2 \n', ...] # Generator expression -- returns iterator stripped_iter = (line.strip() for line in line_list) # List comprehension -- returns list stripped_list = [line.strip() for line in line_list] You can select only certain elements by adding an ‘"if"’ condition: stripped_list = [line.strip() for line in line_list if line != ""] With a list comprehension, you get back a Python list; ‘stripped_list’ is a list containing the resulting lines, not an iterator. Generator expressions return an iterator that computes the values as necessary, not needing to materialize all the values at once. This means that list comprehensions aren’t useful if you’re working with iterators that return an infinite stream or a very large amount of data. Generator expressions are preferable in these situations. Generator expressions are surrounded by parentheses (“()”) and list comprehensions are surrounded by square brackets (“[]”). Generator expressions have the form: ( expression for expr in sequence1 if condition1 for expr2 in sequence2 if condition2 for expr3 in sequence3 ... if condition3 for exprN in sequenceN if conditionN ) Again, for a list comprehension only the outside brackets are different (square brackets instead of parentheses). The elements of the generated output will be the successive values of ‘expression’. The ‘if’ clauses are all optional; if present, ‘expression’ is only evaluated and added to the result when ‘condition’ is true. Generator expressions always have to be written inside parentheses, but the parentheses signalling a function call also count. If you want to create an iterator that will be immediately passed to a function you can write: obj_total = sum(obj.count for obj in list_all_objects()) The ‘for...in’ clauses contain the sequences to be iterated over. The sequences do not have to be the same length, because they are iterated over from left to right, `not' in parallel. For each element in ‘sequence1’, ‘sequence2’ is looped over from the beginning. ‘sequence3’ is then looped over for each resulting pair of elements from ‘sequence1’ and ‘sequence2’. To put it another way, a list comprehension or generator expression is equivalent to the following Python code: for expr1 in sequence1: if not (condition1): continue # Skip this element for expr2 in sequence2: if not (condition2): continue # Skip this element ... for exprN in sequenceN: if not (conditionN): continue # Skip this element # Output the value of # the expression. This means that when there are multiple ‘for...in’ clauses but no ‘if’ clauses, the length of the resulting output will be equal to the product of the lengths of all the sequences. If you have two lists of length 3, the output list is 9 elements long: >>> seq1 = 'abc' >>> seq2 = (1, 2, 3) >>> [(x, y) for x in seq1 for y in seq2] [('a', 1), ('a', 2), ('a', 3), ('b', 1), ('b', 2), ('b', 3), ('c', 1), ('c', 2), ('c', 3)] To avoid introducing an ambiguity into Python’s grammar, if ‘expression’ is creating a tuple, it must be surrounded with parentheses. The first list comprehension below is a syntax error, while the second one is correct: # Syntax error [x, y for x in seq1 for y in seq2] # Correct [(x, y) for x in seq1 for y in seq2]  File: python.info, Node: Generators<2>, Next: Built-in functions, Prev: Generator expressions and list comprehensions, Up: Functional Programming HOWTO 10.5.4 Generators ----------------- Generators are a special class of functions that simplify the task of writing iterators. Regular functions compute a value and return it, but generators return an iterator that returns a stream of values. You’re doubtless familiar with how regular function calls work in Python or C. When you call a function, it gets a private namespace where its local variables are created. When the function reaches a ‘return’ statement, the local variables are destroyed and the value is returned to the caller. A later call to the same function creates a new private namespace and a fresh set of local variables. But, what if the local variables weren’t thrown away on exiting a function? What if you could later resume the function where it left off? This is what generators provide; they can be thought of as resumable functions. Here’s the simplest example of a generator function: >>> def generate_ints(N): ... for i in range(N): ... yield i Any function containing a *note yield: 18f. keyword is a generator function; this is detected by Python’s *note bytecode: 614. compiler which compiles the function specially as a result. When you call a generator function, it doesn’t return a single value; instead it returns a generator object that supports the iterator protocol. On executing the ‘yield’ expression, the generator outputs the value of ‘i’, similar to a ‘return’ statement. The big difference between ‘yield’ and a ‘return’ statement is that on reaching a ‘yield’ the generator’s state of execution is suspended and local variables are preserved. On the next call to the generator’s *note __next__(): f6f. method, the function will resume executing. Here’s a sample usage of the ‘generate_ints()’ generator: >>> gen = generate_ints(3) >>> gen <generator object generate_ints at ...> >>> next(gen) 0 >>> next(gen) 1 >>> next(gen) 2 >>> next(gen) Traceback (most recent call last): File "stdin", line 1, in <module> File "stdin", line 2, in generate_ints StopIteration You could equally write ‘for i in generate_ints(5)’, or ‘a, b, c = generate_ints(3)’. Inside a generator function, ‘return value’ causes ‘StopIteration(value)’ to be raised from the *note __next__(): f6f. method. Once this happens, or the bottom of the function is reached, the procession of values ends and the generator cannot yield any further values. You could achieve the effect of generators manually by writing your own class and storing all the local variables of the generator as instance variables. For example, returning a list of integers could be done by setting ‘self.count’ to 0, and having the *note __next__(): c64. method increment ‘self.count’ and return it. However, for a moderately complicated generator, writing a corresponding class can be much messier. The test suite included with Python’s library, Lib/test/test_generators.py(1), contains a number of more interesting examples. Here’s one generator that implements an in-order traversal of a tree using generators recursively. # A recursive generator that generates Tree leaves in in-order. def inorder(t): if t: for x in inorder(t.left): yield x yield t.label for x in inorder(t.right): yield x Two other examples in ‘test_generators.py’ produce solutions for the N-Queens problem (placing N queens on an NxN chess board so that no queen threatens another) and the Knight’s Tour (finding a route that takes a knight to every square of an NxN chessboard without visiting any square twice). * Menu: * Passing values into a generator:: ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Lib/test/test_generators.py  File: python.info, Node: Passing values into a generator, Up: Generators<2> 10.5.4.1 Passing values into a generator ........................................ In Python 2.4 and earlier, generators only produced output. Once a generator’s code was invoked to create an iterator, there was no way to pass any new information into the function when its execution is resumed. You could hack together this ability by making the generator look at a global variable or by passing in some mutable object that callers then modify, but these approaches are messy. In Python 2.5 there’s a simple way to pass values into a generator. *note yield: 18f. became an expression, returning a value that can be assigned to a variable or otherwise operated on: val = (yield i) I recommend that you `always' put parentheses around a ‘yield’ expression when you’re doing something with the returned value, as in the above example. The parentheses aren’t always necessary, but it’s easier to always add them instead of having to remember when they’re needed. ( PEP 342(1) explains the exact rules, which are that a ‘yield’-expression must always be parenthesized except when it occurs at the top-level expression on the right-hand side of an assignment. This means you can write ‘val = yield i’ but have to use parentheses when there’s an operation, as in ‘val = (yield i) + 12’.) Values are sent into a generator by calling its *note send(value): 1132. method. This method resumes the generator’s code and the ‘yield’ expression returns the specified value. If the regular *note __next__(): f6f. method is called, the ‘yield’ returns ‘None’. Here’s a simple counter that increments by 1 and allows changing the value of the internal counter. def counter(maximum): i = 0 while i < maximum: val = (yield i) # If value provided, change counter if val is not None: i = val else: i += 1 And here’s an example of changing the counter: >>> it = counter(10) >>> next(it) 0 >>> next(it) 1 >>> it.send(8) 8 >>> next(it) 9 >>> next(it) Traceback (most recent call last): File "t.py", line 15, in <module> it.next() StopIteration Because ‘yield’ will often be returning ‘None’, you should always check for this case. Don’t just use its value in expressions unless you’re sure that the *note send(): 1132. method will be the only method used to resume your generator function. In addition to *note send(): 1132, there are two other methods on generators: * *note throw(type, value=None, traceback=None): 1134. is used to raise an exception inside the generator; the exception is raised by the ‘yield’ expression where the generator’s execution is paused. * *note close(): 1136. raises a *note GeneratorExit: d32. exception inside the generator to terminate the iteration. On receiving this exception, the generator’s code must either raise *note GeneratorExit: d32. or *note StopIteration: 486.; catching the exception and doing anything else is illegal and will trigger a *note RuntimeError: 2ba. *note close(): 1136. will also be called by Python’s garbage collector when the generator is garbage-collected. If you need to run cleanup code when a *note GeneratorExit: d32. occurs, I suggest using a ‘try: ... finally:’ suite instead of catching *note GeneratorExit: d32. The cumulative effect of these changes is to turn generators from one-way producers of information into both producers and consumers. Generators also become `coroutines', a more generalized form of subroutines. Subroutines are entered at one point and exited at another point (the top of the function, and a ‘return’ statement), but coroutines can be entered, exited, and resumed at many different points (the ‘yield’ statements). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0342  File: python.info, Node: Built-in functions, Next: The itertools module, Prev: Generators<2>, Up: Functional Programming HOWTO 10.5.5 Built-in functions ------------------------- Let’s look in more detail at built-in functions often used with iterators. Two of Python’s built-in functions, *note map(): c2d. and *note filter(): c2e. duplicate the features of generator expressions: *note map(f, iterA, iterB, ...): c2d. returns an iterator over the sequence ‘f(iterA[0], iterB[0]), f(iterA[1], iterB[1]), f(iterA[2], iterB[2]), ...’. >>> def upper(s): ... return s.upper() >>> list(map(upper, ['sentence', 'fragment'])) ['SENTENCE', 'FRAGMENT'] >>> [upper(s) for s in ['sentence', 'fragment']] ['SENTENCE', 'FRAGMENT'] You can of course achieve the same effect with a list comprehension. *note filter(predicate, iter): c2e. returns an iterator over all the sequence elements that meet a certain condition, and is similarly duplicated by list comprehensions. A `predicate' is a function that returns the truth value of some condition; for use with *note filter(): c2e, the predicate must take a single value. >>> def is_even(x): ... return (x % 2) == 0 >>> list(filter(is_even, range(10))) [0, 2, 4, 6, 8] This can also be written as a list comprehension: >>> list(x for x in range(10) if is_even(x)) [0, 2, 4, 6, 8] *note enumerate(iter, start=0): de3. counts off the elements in the iterable returning 2-tuples containing the count (from `start') and each element. >>> for item in enumerate(['subject', 'verb', 'object']): ... print(item) (0, 'subject') (1, 'verb') (2, 'object') *note enumerate(): de3. is often used when looping through a list and recording the indexes at which certain conditions are met: f = open('data.txt', 'r') for i, line in enumerate(f): if line.strip() == '': print('Blank line at line #%i' % i) *note sorted(iterable, key=None, reverse=False): 444. collects all the elements of the iterable into a list, sorts the list, and returns the sorted result. The `key' and `reverse' arguments are passed through to the constructed list’s *note sort(): 445. method. >>> import random >>> # Generate 8 random numbers between [0, 10000) >>> rand_list = random.sample(range(10000), 8) >>> rand_list [769, 7953, 9828, 6431, 8442, 9878, 6213, 2207] >>> sorted(rand_list) [769, 2207, 6213, 6431, 7953, 8442, 9828, 9878] >>> sorted(rand_list, reverse=True) [9878, 9828, 8442, 7953, 6431, 6213, 2207, 769] (For a more detailed discussion of sorting, see the *note Sorting HOW TO: 12ab.) The *note any(iter): d84. and *note all(iter): d85. built-ins look at the truth values of an iterable’s contents. *note any(): d84. returns ‘True’ if any element in the iterable is a true value, and *note all(): d85. returns ‘True’ if all of the elements are true values: >>> any([0, 1, 0]) True >>> any([0, 0, 0]) False >>> any([1, 1, 1]) True >>> all([0, 1, 0]) False >>> all([0, 0, 0]) False >>> all([1, 1, 1]) True *note zip(iterA, iterB, ...): c32. takes one element from each iterable and returns them in a tuple: zip(['a', 'b', 'c'], (1, 2, 3)) => ('a', 1), ('b', 2), ('c', 3) It doesn’t construct an in-memory list and exhaust all the input iterators before returning; instead tuples are constructed and returned only if they’re requested. (The technical term for this behaviour is lazy evaluation(1).) This iterator is intended to be used with iterables that are all of the same length. If the iterables are of different lengths, the resulting stream will be the same length as the shortest iterable. zip(['a', 'b'], (1, 2, 3)) => ('a', 1), ('b', 2) You should avoid doing this, though, because an element may be taken from the longer iterators and discarded. This means you can’t go on to use the iterators further because you risk skipping a discarded element. ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Lazy_evaluation  File: python.info, Node: The itertools module, Next: The functools module, Prev: Built-in functions, Up: Functional Programming HOWTO 10.5.6 The itertools module --------------------------- The *note itertools: a3. module contains a number of commonly-used iterators as well as functions for combining several iterators. This section will introduce the module’s contents by showing small examples. The module’s functions fall into a few broad classes: * Functions that create a new iterator based on an existing iterator. * Functions for treating an iterator’s elements as function arguments. * Functions for selecting portions of an iterator’s output. * A function for grouping an iterator’s output. * Menu: * Creating new iterators:: * Calling functions on elements:: * Selecting elements:: * Combinatoric functions:: * Grouping elements::  File: python.info, Node: Creating new iterators, Next: Calling functions on elements, Up: The itertools module 10.5.6.1 Creating new iterators ............................... *note itertools.count(start, step): c1b. returns an infinite stream of evenly spaced values. You can optionally supply the starting number, which defaults to 0, and the interval between numbers, which defaults to 1: itertools.count() => 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ... itertools.count(10) => 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ... itertools.count(10, 5) => 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, ... *note itertools.cycle(iter): 17ef. saves a copy of the contents of a provided iterable and returns a new iterator that returns its elements from first to last. The new iterator will repeat these elements infinitely. itertools.cycle([1, 2, 3, 4, 5]) => 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, ... *note itertools.repeat(elem, [n]): 17f0. returns the provided element `n' times, or returns the element endlessly if `n' is not provided. itertools.repeat('abc') => abc, abc, abc, abc, abc, abc, abc, abc, abc, abc, ... itertools.repeat('abc', 5) => abc, abc, abc, abc, abc *note itertools.chain(iterA, iterB, ...): 12ad. takes an arbitrary number of iterables as input, and returns all the elements of the first iterator, then all the elements of the second, and so on, until all of the iterables have been exhausted. itertools.chain(['a', 'b', 'c'], (1, 2, 3)) => a, b, c, 1, 2, 3 *note itertools.islice(iter, [start], stop, [step]): 3a2. returns a stream that’s a slice of the iterator. With a single `stop' argument, it will return the first `stop' elements. If you supply a starting index, you’ll get `stop-start' elements, and if you supply a value for `step', elements will be skipped accordingly. Unlike Python’s string and list slicing, you can’t use negative values for `start', `stop', or `step'. itertools.islice(range(10), 8) => 0, 1, 2, 3, 4, 5, 6, 7 itertools.islice(range(10), 2, 8) => 2, 3, 4, 5, 6, 7 itertools.islice(range(10), 2, 8, 2) => 2, 4, 6 *note itertools.tee(iter, [n]): 17f5. replicates an iterator; it returns `n' independent iterators that will all return the contents of the source iterator. If you don’t supply a value for `n', the default is 2. Replicating iterators requires saving some of the contents of the source iterator, so this can consume significant memory if the iterator is large and one of the new iterators is consumed more than the others. itertools.tee( itertools.count() ) => iterA, iterB where iterA -> 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ... and iterB -> 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ...  File: python.info, Node: Calling functions on elements, Next: Selecting elements, Prev: Creating new iterators, Up: The itertools module 10.5.6.2 Calling functions on elements ...................................... The *note operator: c2. module contains a set of functions corresponding to Python’s operators. Some examples are *note operator.add(a, b): 1817. (adds two values), *note operator.ne(a, b): 1807. (same as ‘a != b’), and *note operator.attrgetter(’id’): 71b. (returns a callable that fetches the ‘.id’ attribute). *note itertools.starmap(func, iter): a28. assumes that the iterable will return a stream of tuples, and calls `func' using these tuples as the arguments: itertools.starmap(os.path.join, [('/bin', 'python'), ('/usr', 'bin', 'java'), ('/usr', 'bin', 'perl'), ('/usr', 'bin', 'ruby')]) => /bin/python, /usr/bin/java, /usr/bin/perl, /usr/bin/ruby  File: python.info, Node: Selecting elements, Next: Combinatoric functions, Prev: Calling functions on elements, Up: The itertools module 10.5.6.3 Selecting elements ........................... Another group of functions chooses a subset of an iterator’s elements based on a predicate. *note itertools.filterfalse(predicate, iter): 1296. is the opposite of *note filter(): c2e, returning all elements for which the predicate returns false: itertools.filterfalse(is_even, itertools.count()) => 1, 3, 5, 7, 9, 11, 13, 15, ... *note itertools.takewhile(predicate, iter): 17f4. returns elements for as long as the predicate returns true. Once the predicate returns false, the iterator will signal the end of its results. def less_than_10(x): return x < 10 itertools.takewhile(less_than_10, itertools.count()) => 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 itertools.takewhile(is_even, itertools.count()) => 0 *note itertools.dropwhile(predicate, iter): 17f2. discards elements while the predicate returns true, and then returns the rest of the iterable’s results. itertools.dropwhile(less_than_10, itertools.count()) => 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ... itertools.dropwhile(is_even, itertools.count()) => 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ... *note itertools.compress(data, selectors): c1a. takes two iterators and returns only those elements of `data' for which the corresponding element of `selectors' is true, stopping whenever either one is exhausted: itertools.compress([1, 2, 3, 4, 5], [True, True, False, False, True]) => 1, 2, 5  File: python.info, Node: Combinatoric functions, Next: Grouping elements, Prev: Selecting elements, Up: The itertools module 10.5.6.4 Combinatoric functions ............................... The *note itertools.combinations(iterable, r): ca6. returns an iterator giving all possible `r'-tuple combinations of the elements contained in `iterable'. itertools.combinations([1, 2, 3, 4, 5], 2) => (1, 2), (1, 3), (1, 4), (1, 5), (2, 3), (2, 4), (2, 5), (3, 4), (3, 5), (4, 5) itertools.combinations([1, 2, 3, 4, 5], 3) => (1, 2, 3), (1, 2, 4), (1, 2, 5), (1, 3, 4), (1, 3, 5), (1, 4, 5), (2, 3, 4), (2, 3, 5), (2, 4, 5), (3, 4, 5) The elements within each tuple remain in the same order as `iterable' returned them. For example, the number 1 is always before 2, 3, 4, or 5 in the examples above. A similar function, *note itertools.permutations(iterable, r=None): 17f6, removes this constraint on the order, returning all possible arrangements of length `r': itertools.permutations([1, 2, 3, 4, 5], 2) => (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4) itertools.permutations([1, 2, 3, 4, 5]) => (1, 2, 3, 4, 5), (1, 2, 3, 5, 4), (1, 2, 4, 3, 5), ... (5, 4, 3, 2, 1) If you don’t supply a value for `r' the length of the iterable is used, meaning that all the elements are permuted. Note that these functions produce all of the possible combinations by position and don’t require that the contents of `iterable' are unique: itertools.permutations('aba', 3) => ('a', 'b', 'a'), ('a', 'a', 'b'), ('b', 'a', 'a'), ('b', 'a', 'a'), ('a', 'a', 'b'), ('a', 'b', 'a') The identical tuple ‘('a', 'a', 'b')’ occurs twice, but the two ‘a’ strings came from different positions. The *note itertools.combinations_with_replacement(iterable, r): c19. function relaxes a different constraint: elements can be repeated within a single tuple. Conceptually an element is selected for the first position of each tuple and then is replaced before the second element is selected. itertools.combinations_with_replacement([1, 2, 3, 4, 5], 2) => (1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 3), (3, 4), (3, 5), (4, 4), (4, 5), (5, 5)  File: python.info, Node: Grouping elements, Prev: Combinatoric functions, Up: The itertools module 10.5.6.5 Grouping elements .......................... The last function I’ll discuss, *note itertools.groupby(iter, key_func=None): 17f3, is the most complicated. ‘key_func(elem)’ is a function that can compute a key value for each element returned by the iterable. If you don’t supply a key function, the key is simply each element itself. *note groupby(): 17f3. collects all the consecutive elements from the underlying iterable that have the same key value, and returns a stream of 2-tuples containing a key value and an iterator for the elements with that key. city_list = [('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL'), ('Anchorage', 'AK'), ('Nome', 'AK'), ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ'), ... ] def get_state(city_state): return city_state[1] itertools.groupby(city_list, get_state) => ('AL', iterator-1), ('AK', iterator-2), ('AZ', iterator-3), ... where iterator-1 => ('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL') iterator-2 => ('Anchorage', 'AK'), ('Nome', 'AK') iterator-3 => ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ') *note groupby(): 17f3. assumes that the underlying iterable’s contents will already be sorted based on the key. Note that the returned iterators also use the underlying iterable, so you have to consume the results of iterator-1 before requesting iterator-2 and its corresponding key.  File: python.info, Node: The functools module, Next: Small functions and the lambda expression, Prev: The itertools module, Up: Functional Programming HOWTO 10.5.7 The functools module --------------------------- The *note functools: 85. module in Python 2.5 contains some higher-order functions. A `higher-order function' takes one or more functions as input and returns a new function. The most useful tool in this module is the *note functools.partial(): 7c8. function. For programs written in a functional style, you’ll sometimes want to construct variants of existing functions that have some of the parameters filled in. Consider a Python function ‘f(a, b, c)’; you may wish to create a new function ‘g(b, c)’ that’s equivalent to ‘f(1, b, c)’; you’re filling in a value for one of ‘f()’’s parameters. This is called “partial function application”. The constructor for *note partial(): 7c8. takes the arguments ‘(function, arg1, arg2, ..., kwarg1=value1, kwarg2=value2)’. The resulting object is callable, so you can just call it to invoke ‘function’ with the filled-in arguments. Here’s a small but realistic example: import functools def log(message, subsystem): """Write the contents of 'message' to the specified subsystem.""" print('%s: %s' % (subsystem, message)) ... server_log = functools.partial(log, subsystem='server') server_log('Unable to open socket') *note functools.reduce(func, iter, [initial_value]): c6f. cumulatively performs an operation on all the iterable’s elements and, therefore, can’t be applied to infinite iterables. `func' must be a function that takes two elements and returns a single value. *note functools.reduce(): c6f. takes the first two elements A and B returned by the iterator and calculates ‘func(A, B)’. It then requests the third element, C, calculates ‘func(func(A, B), C)’, combines this result with the fourth element returned, and continues until the iterable is exhausted. If the iterable returns no values at all, a *note TypeError: 192. exception is raised. If the initial value is supplied, it’s used as a starting point and ‘func(initial_value, A)’ is the first calculation. >>> import operator, functools >>> functools.reduce(operator.concat, ['A', 'BB', 'C']) 'ABBC' >>> functools.reduce(operator.concat, []) Traceback (most recent call last): ... TypeError: reduce() of empty sequence with no initial value >>> functools.reduce(operator.mul, [1, 2, 3], 1) 6 >>> functools.reduce(operator.mul, [], 1) 1 If you use *note operator.add(): 1817. with *note functools.reduce(): c6f, you’ll add up all the elements of the iterable. This case is so common that there’s a special built-in called *note sum(): 1e5. to compute it: >>> import functools, operator >>> functools.reduce(operator.add, [1, 2, 3, 4], 0) 10 >>> sum([1, 2, 3, 4]) 10 >>> sum([]) 0 For many uses of *note functools.reduce(): c6f, though, it can be clearer to just write the obvious *note for: c30. loop: import functools # Instead of: product = functools.reduce(operator.mul, [1, 2, 3], 1) # You can write: product = 1 for i in [1, 2, 3]: product *= i A related function is *note itertools.accumulate(iterable, func=operator.add): 1dd. It performs the same calculation, but instead of returning only the final result, ‘accumulate()’ returns an iterator that also yields each partial result: itertools.accumulate([1, 2, 3, 4, 5]) => 1, 3, 6, 10, 15 itertools.accumulate([1, 2, 3, 4, 5], operator.mul) => 1, 2, 6, 24, 120 * Menu: * The operator module::  File: python.info, Node: The operator module, Up: The functools module 10.5.7.1 The operator module ............................ The *note operator: c2. module was mentioned earlier. It contains a set of functions corresponding to Python’s operators. These functions are often useful in functional-style code because they save you from writing trivial functions that perform a single operation. Some of the functions in this module are: * Math operations: ‘add()’, ‘sub()’, ‘mul()’, ‘floordiv()’, ‘abs()’, … * Logical operations: ‘not_()’, ‘truth()’. * Bitwise operations: ‘and_()’, ‘or_()’, ‘invert()’. * Comparisons: ‘eq()’, ‘ne()’, ‘lt()’, ‘le()’, ‘gt()’, and ‘ge()’. * Object identity: ‘is_()’, ‘is_not()’. Consult the operator module’s documentation for a complete list.  File: python.info, Node: Small functions and the lambda expression, Next: Revision History and Acknowledgements, Prev: The functools module, Up: Functional Programming HOWTO 10.5.8 Small functions and the lambda expression ------------------------------------------------ When writing functional-style programs, you’ll often need little functions that act as predicates or that combine elements in some way. If there’s a Python built-in or a module function that’s suitable, you don’t need to define a new function at all: stripped_lines = [line.strip() for line in lines] existing_files = filter(os.path.exists, file_list) If the function you need doesn’t exist, you need to write it. One way to write small functions is to use the *note lambda: c2f. expression. ‘lambda’ takes a number of parameters and an expression combining these parameters, and creates an anonymous function that returns the value of the expression: adder = lambda x, y: x+y print_assign = lambda name, value: name + '=' + str(value) An alternative is to just use the ‘def’ statement and define a function in the usual way: def adder(x, y): return x + y def print_assign(name, value): return name + '=' + str(value) Which alternative is preferable? That’s a style question; my usual course is to avoid using ‘lambda’. One reason for my preference is that ‘lambda’ is quite limited in the functions it can define. The result has to be computable as a single expression, which means you can’t have multiway ‘if... elif... else’ comparisons or ‘try... except’ statements. If you try to do too much in a ‘lambda’ statement, you’ll end up with an overly complicated expression that’s hard to read. Quick, what’s the following code doing? import functools total = functools.reduce(lambda a, b: (0, a[1] + b[1]), items)[1] You can figure it out, but it takes time to disentangle the expression to figure out what’s going on. Using a short nested ‘def’ statements makes things a little bit better: import functools def combine(a, b): return 0, a[1] + b[1] total = functools.reduce(combine, items)[1] But it would be best of all if I had simply used a ‘for’ loop: total = 0 for a, b in items: total += b Or the *note sum(): 1e5. built-in and a generator expression: total = sum(b for a, b in items) Many uses of *note functools.reduce(): c6f. are clearer when written as ‘for’ loops. Fredrik Lundh once suggested the following set of rules for refactoring uses of ‘lambda’: 1. Write a lambda function. 2. Write a comment explaining what the heck that lambda does. 3. Study the comment for a while, and think of a name that captures the essence of the comment. 4. Convert the lambda to a def statement, using that name. 5. Remove the comment. I really like these rules, but you’re free to disagree about whether this lambda-free style is better.  File: python.info, Node: Revision History and Acknowledgements, Next: References<2>, Prev: Small functions and the lambda expression, Up: Functional Programming HOWTO 10.5.9 Revision History and Acknowledgements -------------------------------------------- The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: Ian Bicking, Nick Coghlan, Nick Efford, Raymond Hettinger, Jim Jewett, Mike Krell, Leandro Lameiro, Jussi Salmela, Collin Winter, Blake Winton. Version 0.1: posted June 30 2006. Version 0.11: posted July 1 2006. Typo fixes. Version 0.2: posted July 10 2006. Merged genexp and listcomp sections into one. Typo fixes. Version 0.21: Added more references suggested on the tutor mailing list. Version 0.30: Adds a section on the ‘functional’ module written by Collin Winter; adds short section on the operator module; a few other edits.  File: python.info, Node: References<2>, Prev: Revision History and Acknowledgements, Up: Functional Programming HOWTO 10.5.10 References ------------------ * Menu: * General:: * Python-specific:: * Python documentation::  File: python.info, Node: General, Next: Python-specific, Up: References<2> 10.5.10.1 General ................. `Structure and Interpretation of Computer Programs', by Harold Abelson and Gerald Jay Sussman with Julie Sussman. Full text at ‘https://mitpress.mit.edu/sicp/’. In this classic textbook of computer science, chapters 2 and 3 discuss the use of sequences and streams to organize the data flow inside a program. The book uses Scheme for its examples, but many of the design approaches described in these chapters are applicable to functional-style Python code. ‘http://www.defmacro.org/ramblings/fp.html’: A general introduction to functional programming that uses Java examples and has a lengthy historical introduction. ‘https://en.wikipedia.org/wiki/Functional_programming’: General Wikipedia entry describing functional programming. ‘https://en.wikipedia.org/wiki/Coroutine’: Entry for coroutines. ‘https://en.wikipedia.org/wiki/Currying’: Entry for the concept of currying.  File: python.info, Node: Python-specific, Next: Python documentation, Prev: General, Up: References<2> 10.5.10.2 Python-specific ......................... ‘http://gnosis.cx/TPiP/’: The first chapter of David Mertz’s book ‘Text Processing in Python’ discusses functional programming for text processing, in the section titled “Utilizing Higher-Order Functions in Text Processing”. Mertz also wrote a 3-part series of articles on functional programming for IBM’s DeveloperWorks site; see part 1(1), part 2(2), and part 3(3), ---------- Footnotes ---------- (1) https://developer.ibm.com/articles/l-prog/ (2) https://developer.ibm.com/tutorials/l-prog2/ (3) https://developer.ibm.com/tutorials/l-prog3/  File: python.info, Node: Python documentation, Prev: Python-specific, Up: References<2> 10.5.10.3 Python documentation .............................. Documentation for the *note itertools: a3. module. Documentation for the *note functools: 85. module. Documentation for the *note operator: c2. module. PEP 289(1): “Generator Expressions” PEP 342(2): “Coroutines via Enhanced Generators” describes the new generator features in Python 2.5. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0289 (2) https://www.python.org/dev/peps/pep-0342  File: python.info, Node: Logging HOWTO, Next: Logging Cookbook, Prev: Functional Programming HOWTO, Up: Python HOWTOs 10.6 Logging HOWTO ================== Author: Vinay Sajip <vinay_sajip at red-dove dot com> * Menu: * Basic Logging Tutorial:: * Advanced Logging Tutorial:: * Logging Levels: Logging Levels<2>. * Useful Handlers:: * Exceptions raised during logging:: * Using arbitrary objects as messages:: * Optimization::  File: python.info, Node: Basic Logging Tutorial, Next: Advanced Logging Tutorial, Up: Logging HOWTO 10.6.1 Basic Logging Tutorial ----------------------------- Logging is a means of tracking events that happen when some software runs. The software’s developer adds logging calls to their code to indicate that certain events have occurred. An event is described by a descriptive message which can optionally contain variable data (i.e. data that is potentially different for each occurrence of the event). Events also have an importance which the developer ascribes to the event; the importance can also be called the `level' or `severity'. * Menu: * When to use logging:: * A simple example:: * Logging to a file:: * Logging from multiple modules:: * Logging variable data:: * Changing the format of displayed messages:: * Displaying the date/time in messages:: * Next Steps::  File: python.info, Node: When to use logging, Next: A simple example, Up: Basic Logging Tutorial 10.6.1.1 When to use logging ............................ Logging provides a set of convenience functions for simple logging usage. These are *note debug(): 1d64, *note info(): 1d8f, *note warning(): 1da1, *note error(): 1da2. and *note critical(): 1da3. To determine when to use logging, see the table below, which states, for each of a set of common tasks, the best tool to use for it. Task you want to perform The best tool for the task ------------------------------------------------------------------------------------- Display console output for ordinary *note print(): 886. usage of a command line script or program Report events that occur during normal *note logging.info(): 1d8f. (or operation of a program (e.g. for *note logging.debug(): 1d64. for very status monitoring or fault detailed output for diagnostic purposes) investigation) Issue a warning regarding a particular *note warnings.warn(): e58. in library runtime event code if the issue is avoidable and the client application should be modified to eliminate the warning *note logging.warning(): 1da1. if there is nothing the client application can do about the situation, but the event should still be noted Report an error regarding a particular Raise an exception runtime event Report suppression of an error without *note logging.error(): 1da2, raising an exception (e.g. error *note logging.exception(): 1da4. or handler in a long-running server *note logging.critical(): 1da3. as process) appropriate for the specific error and application domain The logging functions are named after the level or severity of the events they are used to track. The standard levels and their applicability are described below (in increasing order of severity): Level When it’s used --------------------------------------------------------------------- ‘DEBUG’ Detailed information, typically of interest only when diagnosing problems. ‘INFO’ Confirmation that things are working as expected. ‘WARNING’ An indication that something unexpected happened, or indicative of some problem in the near future (e.g. ‘disk space low’). The software is still working as expected. ‘ERROR’ Due to a more serious problem, the software has not been able to perform some function. ‘CRITICAL’ A serious error, indicating that the program itself may be unable to continue running. The default level is ‘WARNING’, which means that only events of this level and above will be tracked, unless the logging package is configured to do otherwise. Events that are tracked can be handled in different ways. The simplest way of handling tracked events is to print them to the console. Another common way is to write them to a disk file.  File: python.info, Node: A simple example, Next: Logging to a file, Prev: When to use logging, Up: Basic Logging Tutorial 10.6.1.2 A simple example ......................... A very simple example is: import logging logging.warning('Watch out!') # will print a message to the console logging.info('I told you so') # will not print anything If you type these lines into a script and run it, you’ll see: WARNING:root:Watch out! printed out on the console. The ‘INFO’ message doesn’t appear because the default level is ‘WARNING’. The printed message includes the indication of the level and the description of the event provided in the logging call, i.e. ‘Watch out!’. Don’t worry about the ‘root’ part for now: it will be explained later. The actual output can be formatted quite flexibly if you need that; formatting options will also be explained later.  File: python.info, Node: Logging to a file, Next: Logging from multiple modules, Prev: A simple example, Up: Basic Logging Tutorial 10.6.1.3 Logging to a file .......................... A very common situation is that of recording logging events in a file, so let’s look at that next. Be sure to try the following in a newly-started Python interpreter, and don’t just continue from the session described above: import logging logging.basicConfig(filename='example.log',level=logging.DEBUG) logging.debug('This message should go to the log file') logging.info('So should this') logging.warning('And this, too') And now if we open the file and look at what we have, we should find the log messages: DEBUG:root:This message should go to the log file INFO:root:So should this WARNING:root:And this, too This example also shows how you can set the logging level which acts as the threshold for tracking. In this case, because we set the threshold to ‘DEBUG’, all of the messages were printed. If you want to set the logging level from a command-line option such as: --log=INFO and you have the value of the parameter passed for ‘--log’ in some variable `loglevel', you can use: getattr(logging, loglevel.upper()) to get the value which you’ll pass to *note basicConfig(): 1e0. via the `level' argument. You may want to error check any user input value, perhaps as in the following example: # assuming loglevel is bound to the string value obtained from the # command line argument. Convert to upper case to allow the user to # specify --log=DEBUG or --log=debug numeric_level = getattr(logging, loglevel.upper(), None) if not isinstance(numeric_level, int): raise ValueError('Invalid log level: %s' % loglevel) logging.basicConfig(level=numeric_level, ...) The call to *note basicConfig(): 1e0. should come `before' any calls to *note debug(): 1d64, *note info(): 1d8f. etc. As it’s intended as a one-off simple configuration facility, only the first call will actually do anything: subsequent calls are effectively no-ops. If you run the above script several times, the messages from successive runs are appended to the file `example.log'. If you want each run to start afresh, not remembering the messages from earlier runs, you can specify the `filemode' argument, by changing the call in the above example to: logging.basicConfig(filename='example.log', filemode='w', level=logging.DEBUG) The output will be the same as before, but the log file is no longer appended to, so the messages from earlier runs are lost.  File: python.info, Node: Logging from multiple modules, Next: Logging variable data, Prev: Logging to a file, Up: Basic Logging Tutorial 10.6.1.4 Logging from multiple modules ...................................... If your program consists of multiple modules, here’s an example of how you could organize logging in it: # myapp.py import logging import mylib def main(): logging.basicConfig(filename='myapp.log', level=logging.INFO) logging.info('Started') mylib.do_something() logging.info('Finished') if __name__ == '__main__': main() # mylib.py import logging def do_something(): logging.info('Doing something') If you run `myapp.py', you should see this in `myapp.log': INFO:root:Started INFO:root:Doing something INFO:root:Finished which is hopefully what you were expecting to see. You can generalize this to multiple modules, using the pattern in `mylib.py'. Note that for this simple usage pattern, you won’t know, by looking in the log file, `where' in your application your messages came from, apart from looking at the event description. If you want to track the location of your messages, you’ll need to refer to the documentation beyond the tutorial level – see *note Advanced Logging Tutorial: b73.  File: python.info, Node: Logging variable data, Next: Changing the format of displayed messages, Prev: Logging from multiple modules, Up: Basic Logging Tutorial 10.6.1.5 Logging variable data .............................. To log variable data, use a format string for the event description message and append the variable data as arguments. For example: import logging logging.warning('%s before you %s', 'Look', 'leap!') will display: WARNING:root:Look before you leap! As you can see, merging of variable data into the event description message uses the old, %-style of string formatting. This is for backwards compatibility: the logging package pre-dates newer formatting options such as *note str.format(): 4da. and *note string.Template: 3eb. These newer formatting options `are' supported, but exploring them is outside the scope of this tutorial: see *note Using particular formatting styles throughout your application: 1d87. for more information.  File: python.info, Node: Changing the format of displayed messages, Next: Displaying the date/time in messages, Prev: Logging variable data, Up: Basic Logging Tutorial 10.6.1.6 Changing the format of displayed messages .................................................. To change the format which is used to display messages, you need to specify the format you want to use: import logging logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG) logging.debug('This message should appear on the console') logging.info('So should this') logging.warning('And this, too') which would print: DEBUG:This message should appear on the console INFO:So should this WARNING:And this, too Notice that the ‘root’ which appeared in earlier examples has disappeared. For a full set of things that can appear in format strings, you can refer to the documentation for *note LogRecord attributes: 1d85, but for simple usage, you just need the `levelname' (severity), `message' (event description, including variable data) and perhaps to display when the event occurred. This is described in the next section.  File: python.info, Node: Displaying the date/time in messages, Next: Next Steps, Prev: Changing the format of displayed messages, Up: Basic Logging Tutorial 10.6.1.7 Displaying the date/time in messages ............................................. To display the date and time of an event, you would place ‘%(asctime)s’ in your format string: import logging logging.basicConfig(format='%(asctime)s %(message)s') logging.warning('is when this event was logged.') which should print something like this: 2010-12-12 11:41:42,612 is when this event was logged. The default format for date/time display (shown above) is like ISO8601 or RFC 3339(1). If you need more control over the formatting of the date/time, provide a `datefmt' argument to ‘basicConfig’, as in this example: import logging logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p') logging.warning('is when this event was logged.') which would display something like this: 12/12/2010 11:46:36 AM is when this event was logged. The format of the `datefmt' argument is the same as supported by *note time.strftime(): b65. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc3339.html  File: python.info, Node: Next Steps, Prev: Displaying the date/time in messages, Up: Basic Logging Tutorial 10.6.1.8 Next Steps ................... That concludes the basic tutorial. It should be enough to get you up and running with logging. There’s a lot more that the logging package offers, but to get the best out of it, you’ll need to invest a little more of your time in reading the following sections. If you’re ready for that, grab some of your favourite beverage and carry on. If your logging needs are simple, then use the above examples to incorporate logging into your own scripts, and if you run into problems or don’t understand something, please post a question on the comp.lang.python Usenet group (available at ‘https://groups.google.com/forum/#!forum/comp.lang.python’) and you should receive help before too long. Still here? You can carry on reading the next few sections, which provide a slightly more advanced/in-depth tutorial than the basic one above. After that, you can take a look at the *note Logging Cookbook: b74.  File: python.info, Node: Advanced Logging Tutorial, Next: Logging Levels<2>, Prev: Basic Logging Tutorial, Up: Logging HOWTO 10.6.2 Advanced Logging Tutorial -------------------------------- The logging library takes a modular approach and offers several categories of components: loggers, handlers, filters, and formatters. * Loggers expose the interface that application code directly uses. * Handlers send the log records (created by loggers) to the appropriate destination. * Filters provide a finer grained facility for determining which log records to output. * Formatters specify the layout of log records in the final output. Log event information is passed between loggers, handlers, filters and formatters in a *note LogRecord: 906. instance. Logging is performed by calling methods on instances of the *note Logger: 3a7. class (hereafter called `loggers'). Each instance has a name, and they are conceptually arranged in a namespace hierarchy using dots (periods) as separators. For example, a logger named ‘scan’ is the parent of loggers ‘scan.text’, ‘scan.html’ and ‘scan.pdf’. Logger names can be anything you want, and indicate the area of an application in which a logged message originates. A good convention to use when naming loggers is to use a module-level logger, in each module which uses logging, named as follows: logger = logging.getLogger(__name__) This means that logger names track the package/module hierarchy, and it’s intuitively obvious where events are logged just from the logger name. The root of the hierarchy of loggers is called the root logger. That’s the logger used by the functions *note debug(): 1d64, *note info(): 1d8f, *note warning(): 1da1, *note error(): 1da2. and *note critical(): 1da3, which just call the same-named method of the root logger. The functions and the methods have the same signatures. The root logger’s name is printed as ‘root’ in the logged output. It is, of course, possible to log messages to different destinations. Support is included in the package for writing log messages to files, HTTP GET/POST locations, email via SMTP, generic sockets, queues, or OS-specific logging mechanisms such as syslog or the Windows NT event log. Destinations are served by `handler' classes. You can create your own log destination class if you have special requirements not met by any of the built-in handler classes. By default, no destination is set for any logging messages. You can specify a destination (such as console or file) by using *note basicConfig(): 1e0. as in the tutorial examples. If you call the functions *note debug(): 1d64, *note info(): 1d8f, *note warning(): 1da1, *note error(): 1da2. and *note critical(): 1da3, they will check to see if no destination is set; and if one is not set, they will set a destination of the console (‘sys.stderr’) and a default format for the displayed message before delegating to the root logger to do the actual message output. The default format set by *note basicConfig(): 1e0. for messages is: severity:logger name:message You can change this by passing a format string to *note basicConfig(): 1e0. with the `format' keyword argument. For all options regarding how a format string is constructed, see *note Formatter Objects: 1d83. * Menu: * Logging Flow:: * Loggers:: * Handlers:: * Formatters:: * Configuring Logging:: * What happens if no configuration is provided:: * Configuring Logging for a Library::  File: python.info, Node: Logging Flow, Next: Loggers, Up: Advanced Logging Tutorial 10.6.2.1 Logging Flow ..................... The flow of log event information in loggers and handlers is illustrated in the following diagram. [python-figures/logging_flow]  File: python.info, Node: Loggers, Next: Handlers, Prev: Logging Flow, Up: Advanced Logging Tutorial 10.6.2.2 Loggers ................ *note Logger: 3a7. objects have a threefold job. First, they expose several methods to application code so that applications can log messages at runtime. Second, logger objects determine which log messages to act upon based upon severity (the default filtering facility) or filter objects. Third, logger objects pass along relevant log messages to all interested log handlers. The most widely used methods on logger objects fall into two categories: configuration and message sending. These are the most common configuration methods: * *note Logger.setLevel(): 1d5d. specifies the lowest-severity log message a logger will handle, where debug is the lowest built-in severity level and critical is the highest built-in severity. For example, if the severity level is INFO, the logger will handle only INFO, WARNING, ERROR, and CRITICAL messages and will ignore DEBUG messages. * *note Logger.addHandler(): 1d6a. and *note Logger.removeHandler(): 1d6b. add and remove handler objects from the logger object. Handlers are covered in more detail in *note Handlers: 3eb1. * *note Logger.addFilter(): 1d67. and *note Logger.removeFilter(): 1d68. add and remove filter objects from the logger object. Filters are covered in more detail in *note Filter Objects: 1d8c. You don’t need to always call these methods on every logger you create. See the last two paragraphs in this section. With the logger object configured, the following methods create log messages: * *note Logger.debug(): 710, *note Logger.info(): 1d63, *note Logger.warning(): 1d65, *note Logger.error(): 1d66, and *note Logger.critical(): 70f. all create log records with a message and a level that corresponds to their respective method names. The message is actually a format string, which may contain the standard string substitution syntax of ‘%s’, ‘%d’, ‘%f’, and so on. The rest of their arguments is a list of objects that correspond with the substitution fields in the message. With regard to ‘**kwargs’, the logging methods care only about a keyword of ‘exc_info’ and use it to determine whether to log exception information. * *note Logger.exception(): 70e. creates a log message similar to *note Logger.error(): 1d66. The difference is that *note Logger.exception(): 70e. dumps a stack trace along with it. Call this method only from an exception handler. * *note Logger.log(): 70d. takes a log level as an explicit argument. This is a little more verbose for logging messages than using the log level convenience methods listed above, but this is how to log at custom log levels. *note getLogger(): 1d5b. returns a reference to a logger instance with the specified name if it is provided, or ‘root’ if not. The names are period-separated hierarchical structures. Multiple calls to *note getLogger(): 1d5b. with the same name will return a reference to the same logger object. Loggers that are further down in the hierarchical list are children of loggers higher up in the list. For example, given a logger with a name of ‘foo’, loggers with names of ‘foo.bar’, ‘foo.bar.baz’, and ‘foo.bam’ are all descendants of ‘foo’. Loggers have a concept of `effective level'. If a level is not explicitly set on a logger, the level of its parent is used instead as its effective level. If the parent has no explicit level set, `its' parent is examined, and so on - all ancestors are searched until an explicitly set level is found. The root logger always has an explicit level set (‘WARNING’ by default). When deciding whether to process an event, the effective level of the logger is used to determine whether the event is passed to the logger’s handlers. Child loggers propagate messages up to the handlers associated with their ancestor loggers. Because of this, it is unnecessary to define and configure handlers for all the loggers an application uses. It is sufficient to configure handlers for a top-level logger and create child loggers as needed. (You can, however, turn off propagation by setting the `propagate' attribute of a logger to ‘False’.)  File: python.info, Node: Handlers, Next: Formatters, Prev: Loggers, Up: Advanced Logging Tutorial 10.6.2.3 Handlers ................. *note Handler: 1d62. objects are responsible for dispatching the appropriate log messages (based on the log messages’ severity) to the handler’s specified destination. *note Logger: 3a7. objects can add zero or more handler objects to themselves with an *note addHandler(): 1d6a. method. As an example scenario, an application may want to send all log messages to a log file, all log messages of error or higher to stdout, and all messages of critical to an email address. This scenario requires three individual handlers where each handler is responsible for sending messages of a specific severity to a specific location. The standard library includes quite a few handler types (see *note Useful Handlers: 3eb3.); the tutorials use mainly *note StreamHandler: b75. and *note FileHandler: 1dc8. in its examples. There are very few methods in a handler for application developers to concern themselves with. The only handler methods that seem relevant for application developers who are using the built-in handler objects (that is, not creating custom handlers) are the following configuration methods: * The *note setLevel(): 1d77. method, just as in logger objects, specifies the lowest severity that will be dispatched to the appropriate destination. Why are there two ‘setLevel()’ methods? The level set in the logger determines which severity of messages it will pass to its handlers. The level set in each handler determines which messages that handler will send on. * *note setFormatter(): 1d78. selects a Formatter object for this handler to use. * *note addFilter(): 1d79. and *note removeFilter(): 1d7a. respectively configure and deconfigure filter objects on handlers. Application code should not directly instantiate and use instances of *note Handler: 1d62. Instead, the *note Handler: 1d62. class is a base class that defines the interface that all handlers should have and establishes some default behavior that child classes can use (or override).  File: python.info, Node: Formatters, Next: Configuring Logging, Prev: Handlers, Up: Advanced Logging Tutorial 10.6.2.4 Formatters ................... Formatter objects configure the final order, structure, and contents of the log message. Unlike the base *note logging.Handler: 1d62. class, application code may instantiate formatter classes, although you could likely subclass the formatter if your application needs special behavior. The constructor takes three optional arguments – a message format string, a date format string and a style indicator. -- Method: logging.Formatter.__init__ (fmt=None, datefmt=None, style='%') If there is no message format string, the default is to use the raw message. If there is no date format string, the default date format is: %Y-%m-%d %H:%M:%S with the milliseconds tacked on at the end. The ‘style’ is one of ‘%’, ‘{’ or ‘$’. If one of these is not specified, then ‘%’ will be used. If the ‘style’ is ‘%’, the message format string uses ‘%(<dictionary key>)s’ styled string substitution; the possible keys are documented in *note LogRecord attributes: 1d85. If the style is ‘{’, the message format string is assumed to be compatible with *note str.format(): 4da. (using keyword arguments), while if the style is ‘$’ then the message format string should conform to what is expected by *note string.Template.substitute(): f94. Changed in version 3.2: Added the ‘style’ parameter. The following message format string will log the time in a human-readable format, the severity of the message, and the contents of the message, in that order: '%(asctime)s - %(levelname)s - %(message)s' Formatters use a user-configurable function to convert the creation time of a record to a tuple. By default, *note time.localtime(): 155c. is used; to change this for a particular formatter instance, set the ‘converter’ attribute of the instance to a function with the same signature as *note time.localtime(): 155c. or *note time.gmtime(): b3f. To change it for all formatters, for example if you want all logging times to be shown in GMT, set the ‘converter’ attribute in the Formatter class (to ‘time.gmtime’ for GMT display).  File: python.info, Node: Configuring Logging, Next: What happens if no configuration is provided, Prev: Formatters, Up: Advanced Logging Tutorial 10.6.2.5 Configuring Logging ............................ Programmers can configure logging in three ways: 1. Creating loggers, handlers, and formatters explicitly using Python code that calls the configuration methods listed above. 2. Creating a logging config file and reading it using the *note fileConfig(): 3a9. function. 3. Creating a dictionary of configuration information and passing it to the *note dictConfig(): b2b. function. For the reference documentation on the last two options, see *note Configuration functions: c88. The following example configures a very simple logger, a console handler, and a simple formatter using Python code: import logging # create logger logger = logging.getLogger('simple_example') logger.setLevel(logging.DEBUG) # create console handler and set level to debug ch = logging.StreamHandler() ch.setLevel(logging.DEBUG) # create formatter formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') # add formatter to ch ch.setFormatter(formatter) # add ch to logger logger.addHandler(ch) # 'application' code logger.debug('debug message') logger.info('info message') logger.warning('warn message') logger.error('error message') logger.critical('critical message') Running this module from the command line produces the following output: $ python simple_logging_module.py 2005-03-19 15:10:26,618 - simple_example - DEBUG - debug message 2005-03-19 15:10:26,620 - simple_example - INFO - info message 2005-03-19 15:10:26,695 - simple_example - WARNING - warn message 2005-03-19 15:10:26,697 - simple_example - ERROR - error message 2005-03-19 15:10:26,773 - simple_example - CRITICAL - critical message The following Python module creates a logger, handler, and formatter nearly identical to those in the example listed above, with the only difference being the names of the objects: import logging import logging.config logging.config.fileConfig('logging.conf') # create logger logger = logging.getLogger('simpleExample') # 'application' code logger.debug('debug message') logger.info('info message') logger.warning('warn message') logger.error('error message') logger.critical('critical message') Here is the logging.conf file: [loggers] keys=root,simpleExample [handlers] keys=consoleHandler [formatters] keys=simpleFormatter [logger_root] level=DEBUG handlers=consoleHandler [logger_simpleExample] level=DEBUG handlers=consoleHandler qualname=simpleExample propagate=0 [handler_consoleHandler] class=StreamHandler level=DEBUG formatter=simpleFormatter args=(sys.stdout,) [formatter_simpleFormatter] format=%(asctime)s - %(name)s - %(levelname)s - %(message)s datefmt= The output is nearly identical to that of the non-config-file-based example: $ python simple_logging_config.py 2005-03-19 15:38:55,977 - simpleExample - DEBUG - debug message 2005-03-19 15:38:55,979 - simpleExample - INFO - info message 2005-03-19 15:38:56,054 - simpleExample - WARNING - warn message 2005-03-19 15:38:56,055 - simpleExample - ERROR - error message 2005-03-19 15:38:56,130 - simpleExample - CRITICAL - critical message You can see that the config file approach has a few advantages over the Python code approach, mainly separation of configuration and code and the ability of noncoders to easily modify the logging properties. Warning: The *note fileConfig(): 3a9. function takes a default parameter, ‘disable_existing_loggers’, which defaults to ‘True’ for reasons of backward compatibility. This may or may not be what you want, since it will cause any non-root loggers existing before the *note fileConfig(): 3a9. call to be disabled unless they (or an ancestor) are explicitly named in the configuration. Please refer to the reference documentation for more information, and specify ‘False’ for this parameter if you wish. The dictionary passed to *note dictConfig(): b2b. can also specify a Boolean value with key ‘disable_existing_loggers’, which if not specified explicitly in the dictionary also defaults to being interpreted as ‘True’. This leads to the logger-disabling behaviour described above, which may not be what you want - in which case, provide the key explicitly with a value of ‘False’. Note that the class names referenced in config files need to be either relative to the logging module, or absolute values which can be resolved using normal import mechanisms. Thus, you could use either *note WatchedFileHandler: 1dd9. (relative to the logging module) or ‘mypackage.mymodule.MyHandler’ (for a class defined in package ‘mypackage’ and module ‘mymodule’, where ‘mypackage’ is available on the Python import path). In Python 3.2, a new means of configuring logging has been introduced, using dictionaries to hold configuration information. This provides a superset of the functionality of the config-file-based approach outlined above, and is the recommended configuration method for new applications and deployments. Because a Python dictionary is used to hold configuration information, and since you can populate that dictionary using different means, you have more options for configuration. For example, you can use a configuration file in JSON format, or, if you have access to YAML processing functionality, a file in YAML format, to populate the configuration dictionary. Or, of course, you can construct the dictionary in Python code, receive it in pickled form over a socket, or use whatever approach makes sense for your application. Here’s an example of the same configuration as above, in YAML format for the new dictionary-based approach: version: 1 formatters: simple: format: '%(asctime)s - %(name)s - %(levelname)s - %(message)s' handlers: console: class: logging.StreamHandler level: DEBUG formatter: simple stream: ext://sys.stdout loggers: simpleExample: level: DEBUG handlers: [console] propagate: no root: level: DEBUG handlers: [console] For more information about logging using a dictionary, see *note Configuration functions: c88.  File: python.info, Node: What happens if no configuration is provided, Next: Configuring Logging for a Library, Prev: Configuring Logging, Up: Advanced Logging Tutorial 10.6.2.6 What happens if no configuration is provided ..................................................... If no logging configuration is provided, it is possible to have a situation where a logging event needs to be output, but no handlers can be found to output the event. The behaviour of the logging package in these circumstances is dependent on the Python version. For versions of Python prior to 3.2, the behaviour is as follows: * If `logging.raiseExceptions' is ‘False’ (production mode), the event is silently dropped. * If `logging.raiseExceptions' is ‘True’ (development mode), a message ‘No handlers could be found for logger X.Y.Z’ is printed once. In Python 3.2 and later, the behaviour is as follows: * The event is output using a ‘handler of last resort’, stored in ‘logging.lastResort’. This internal handler is not associated with any logger, and acts like a *note StreamHandler: b75. which writes the event description message to the current value of ‘sys.stderr’ (therefore respecting any redirections which may be in effect). No formatting is done on the message - just the bare event description message is printed. The handler’s level is set to ‘WARNING’, so all events at this and greater severities will be output. To obtain the pre-3.2 behaviour, ‘logging.lastResort’ can be set to ‘None’.  File: python.info, Node: Configuring Logging for a Library, Prev: What happens if no configuration is provided, Up: Advanced Logging Tutorial 10.6.2.7 Configuring Logging for a Library .......................................... When developing a library which uses logging, you should take care to document how the library uses logging - for example, the names of loggers used. Some consideration also needs to be given to its logging configuration. If the using application does not use logging, and library code makes logging calls, then (as described in the previous section) events of severity ‘WARNING’ and greater will be printed to ‘sys.stderr’. This is regarded as the best default behaviour. If for some reason you `don’t' want these messages printed in the absence of any logging configuration, you can attach a do-nothing handler to the top-level logger for your library. This avoids the message being printed, since a handler will always be found for the library’s events: it just doesn’t produce any output. If the library user configures logging for application use, presumably that configuration will add some handlers, and if levels are suitably configured then logging calls made in library code will send output to those handlers, as normal. A do-nothing handler is included in the logging package: *note NullHandler: c1c. (since Python 3.1). An instance of this handler could be added to the top-level logger of the logging namespace used by the library (`if' you want to prevent your library’s logged events being output to ‘sys.stderr’ in the absence of logging configuration). If all logging by a library `foo' is done using loggers with names matching ‘foo.x’, ‘foo.x.y’, etc. then the code: import logging logging.getLogger('foo').addHandler(logging.NullHandler()) should have the desired effect. If an organisation produces a number of libraries, then the logger name specified can be ‘orgname.foo’ rather than just ‘foo’. Note: It is strongly advised that you `do not add any handlers other than' *note NullHandler: c1c. `to your library’s loggers'. This is because the configuration of handlers is the prerogative of the application developer who uses your library. The application developer knows their target audience and what handlers are most appropriate for their application: if you add handlers ‘under the hood’, you might well interfere with their ability to carry out unit tests and deliver logs which suit their requirements.  File: python.info, Node: Logging Levels<2>, Next: Useful Handlers, Prev: Advanced Logging Tutorial, Up: Logging HOWTO 10.6.3 Logging Levels --------------------- The numeric values of logging levels are given in the following table. These are primarily of interest if you want to define your own levels, and need them to have specific values relative to the predefined levels. If you define a level with the same numeric value, it overwrites the predefined value; the predefined name is lost. Level Numeric value --------------------------------------- ‘CRITICAL’ 50 ‘ERROR’ 40 ‘WARNING’ 30 ‘INFO’ 20 ‘DEBUG’ 10 ‘NOTSET’ 0 Levels can also be associated with loggers, being set either by the developer or through loading a saved logging configuration. When a logging method is called on a logger, the logger compares its own level with the level associated with the method call. If the logger’s level is higher than the method call’s, no logging message is actually generated. This is the basic mechanism controlling the verbosity of logging output. Logging messages are encoded as instances of the *note LogRecord: 906. class. When a logger decides to actually log an event, a *note LogRecord: 906. instance is created from the logging message. Logging messages are subjected to a dispatch mechanism through the use of `handlers', which are instances of subclasses of the *note Handler: 1d62. class. Handlers are responsible for ensuring that a logged message (in the form of a *note LogRecord: 906.) ends up in a particular location (or set of locations) which is useful for the target audience for that message (such as end users, support desk staff, system administrators, developers). Handlers are passed *note LogRecord: 906. instances intended for particular destinations. Each logger can have zero, one or more handlers associated with it (via the *note addHandler(): 1d6a. method of *note Logger: 3a7.). In addition to any handlers directly associated with a logger, `all handlers associated with all ancestors of the logger' are called to dispatch the message (unless the `propagate' flag for a logger is set to a false value, at which point the passing to ancestor handlers stops). Just as for loggers, handlers can have levels associated with them. A handler’s level acts as a filter in the same way as a logger’s level does. If a handler decides to actually dispatch an event, the *note emit(): 1d81. method is used to send the message to its destination. Most user-defined subclasses of *note Handler: 1d62. will need to override this *note emit(): 1d81. * Menu: * Custom Levels::  File: python.info, Node: Custom Levels, Up: Logging Levels<2> 10.6.3.1 Custom Levels ...................... Defining your own levels is possible, but should not be necessary, as the existing levels have been chosen on the basis of practical experience. However, if you are convinced that you need custom levels, great care should be exercised when doing this, and it is possibly `a very bad idea to define custom levels if you are developing a library'. That’s because if multiple library authors all define their own custom levels, there is a chance that the logging output from such multiple libraries used together will be difficult for the using developer to control and/or interpret, because a given numeric value might mean different things for different libraries.  File: python.info, Node: Useful Handlers, Next: Exceptions raised during logging, Prev: Logging Levels<2>, Up: Logging HOWTO 10.6.4 Useful Handlers ---------------------- In addition to the base *note Handler: 1d62. class, many useful subclasses are provided: 1. *note StreamHandler: b75. instances send messages to streams (file-like objects). 2. *note FileHandler: 1dc8. instances send messages to disk files. 3. *note BaseRotatingHandler: 1ddd. is the base class for handlers that rotate log files at a certain point. It is not meant to be instantiated directly. Instead, use *note RotatingFileHandler: 1db9. or *note TimedRotatingFileHandler: 86e. 4. *note RotatingFileHandler: 1db9. instances send messages to disk files, with support for maximum log file sizes and log file rotation. 5. *note TimedRotatingFileHandler: 86e. instances send messages to disk files, rotating the log file at certain timed intervals. 6. *note SocketHandler: 86f. instances send messages to TCP/IP sockets. Since 3.4, Unix domain sockets are also supported. 7. *note DatagramHandler: 870. instances send messages to UDP sockets. Since 3.4, Unix domain sockets are also supported. 8. *note SMTPHandler: 1e09. instances send messages to a designated email address. 9. *note SysLogHandler: a1e. instances send messages to a Unix syslog daemon, possibly on a remote machine. 10. *note NTEventLogHandler: 1e01. instances send messages to a Windows NT/2000/XP event log. 11. *note MemoryHandler: 1dc2. instances send messages to a buffer in memory, which is flushed whenever specific criteria are met. 12. *note HTTPHandler: 711. instances send messages to an HTTP server using either ‘GET’ or ‘POST’ semantics. 13. *note WatchedFileHandler: 1dd9. instances watch the file they are logging to. If the file changes, it is closed and reopened using the file name. This handler is only useful on Unix-like systems; Windows does not support the underlying mechanism used. 14. *note QueueHandler: 1e1c. instances send messages to a queue, such as those implemented in the *note queue: da. or *note multiprocessing: b7. modules. 15. *note NullHandler: c1c. instances do nothing with error messages. They are used by library developers who want to use logging, but want to avoid the ‘No handlers could be found for logger XXX’ message which can be displayed if the library user has not configured logging. See *note Configuring Logging for a Library: 1dd6. for more information. New in version 3.1: The *note NullHandler: c1c. class. New in version 3.2: The *note QueueHandler: 1e1c. class. The *note NullHandler: c1c, *note StreamHandler: b75. and *note FileHandler: 1dc8. classes are defined in the core logging package. The other handlers are defined in a sub-module, *note logging.handlers: ac. (There is also another sub-module, *note logging.config: ab, for configuration functionality.) Logged messages are formatted for presentation through instances of the *note Formatter: 1d61. class. They are initialized with a format string suitable for use with the % operator and a dictionary. For formatting multiple messages in a batch, instances of ‘BufferingFormatter’ can be used. In addition to the format string (which is applied to each message in the batch), there is provision for header and trailer format strings. When filtering based on logger level and/or handler level is not enough, instances of *note Filter: b77. can be added to both *note Logger: 3a7. and *note Handler: 1d62. instances (through their *note addFilter(): 1d79. method). Before deciding to process a message further, both loggers and handlers consult all their filters for permission. If any filter returns a false value, the message is not processed further. The basic *note Filter: b77. functionality allows filtering by specific logger name. If this feature is used, messages sent to the named logger and its children are allowed through the filter, and all others dropped.  File: python.info, Node: Exceptions raised during logging, Next: Using arbitrary objects as messages, Prev: Useful Handlers, Up: Logging HOWTO 10.6.5 Exceptions raised during logging --------------------------------------- The logging package is designed to swallow exceptions which occur while logging in production. This is so that errors which occur while handling logging events - such as logging misconfiguration, network or other similar errors - do not cause the application using logging to terminate prematurely. *note SystemExit: 5fc. and *note KeyboardInterrupt: 197. exceptions are never swallowed. Other exceptions which occur during the *note emit(): 1d81. method of a *note Handler: 1d62. subclass are passed to its *note handleError(): 1d80. method. The default implementation of *note handleError(): 1d80. in *note Handler: 1d62. checks to see if a module-level variable, ‘raiseExceptions’, is set. If set, a traceback is printed to *note sys.stderr: 30f. If not set, the exception is swallowed. Note: The default value of ‘raiseExceptions’ is ‘True’. This is because during development, you typically want to be notified of any exceptions that occur. It’s advised that you set ‘raiseExceptions’ to ‘False’ for production usage.  File: python.info, Node: Using arbitrary objects as messages, Next: Optimization, Prev: Exceptions raised during logging, Up: Logging HOWTO 10.6.6 Using arbitrary objects as messages ------------------------------------------ In the preceding sections and examples, it has been assumed that the message passed when logging the event is a string. However, this is not the only possibility. You can pass an arbitrary object as a message, and its *note __str__(): e37. method will be called when the logging system needs to convert it to a string representation. In fact, if you want to, you can avoid computing a string representation altogether - for example, the *note SocketHandler: 86f. emits an event by pickling it and sending it over the wire.  File: python.info, Node: Optimization, Prev: Using arbitrary objects as messages, Up: Logging HOWTO 10.6.7 Optimization ------------------- Formatting of message arguments is deferred until it cannot be avoided. However, computing the arguments passed to the logging method can also be expensive, and you may want to avoid doing it if the logger will just throw away your event. To decide what to do, you can call the *note isEnabledFor(): 1d60. method which takes a level argument and returns true if the event would be created by the Logger for that level of call. You can write code like this: if logger.isEnabledFor(logging.DEBUG): logger.debug('Message with %s, %s', expensive_func1(), expensive_func2()) so that if the logger’s threshold is set above ‘DEBUG’, the calls to ‘expensive_func1()’ and ‘expensive_func2()’ are never made. Note: In some cases, *note isEnabledFor(): 1d60. can itself be more expensive than you’d like (e.g. for deeply nested loggers where an explicit level is only set high up in the logger hierarchy). In such cases (or if you want to avoid calling a method in tight loops), you can cache the result of a call to *note isEnabledFor(): 1d60. in a local or instance variable, and use that instead of calling the method each time. Such a cached value would only need to be recomputed when the logging configuration changes dynamically while the application is running (which is not all that common). There are other optimizations which can be made for specific applications which need more precise control over what logging information is collected. Here’s a list of things you can do to avoid processing during logging which you don’t need: What you don’t want to collect How to avoid collecting it ------------------------------------------------------------------------------------------------- Information about where calls were made from. Set ‘logging._srcfile’ to ‘None’. This avoids calling *note sys._getframe(): e64, which may help to speed up your code in environments like PyPy (which can’t speed up code that uses *note sys._getframe(): e64.), if and when PyPy supports Python 3.x. Threading information. Set ‘logging.logThreads’ to ‘0’. Process information. Set ‘logging.logProcesses’ to ‘0’. Also note that the core logging module only includes the basic handlers. If you don’t import *note logging.handlers: ac. and *note logging.config: ab, they won’t take up any memory. See also ........ Module *note logging: aa. API reference for the logging module. Module *note logging.config: ab. Configuration API for the logging module. Module *note logging.handlers: ac. Useful handlers included with the logging module. *note A logging cookbook: b74.  File: python.info, Node: Logging Cookbook, Next: Regular Expression HOWTO, Prev: Logging HOWTO, Up: Python HOWTOs 10.7 Logging Cookbook ===================== Author: Vinay Sajip <vinay_sajip at red-dove dot com> This page contains a number of recipes related to logging, which have been found useful in the past. * Menu: * Using logging in multiple modules:: * Logging from multiple threads:: * Multiple handlers and formatters:: * Logging to multiple destinations:: * Configuration server example:: * Dealing with handlers that block:: * Sending and receiving logging events across a network:: * Adding contextual information to your logging output:: * Logging to a single file from multiple processes:: * Using file rotation:: * Use of alternative formatting styles:: * Customizing LogRecord:: * Subclassing QueueHandler - a ZeroMQ example:: * Subclassing QueueListener - a ZeroMQ example:: * An example dictionary-based configuration:: * Using a rotator and namer to customize log rotation processing:: * A more elaborate multiprocessing example:: * Inserting a BOM into messages sent to a SysLogHandler:: * Implementing structured logging:: * Customizing handlers with dictConfig(): Customizing handlers with dictConfig. * Using particular formatting styles throughout your application:: * Configuring filters with dictConfig(): Configuring filters with dictConfig. * Customized exception formatting:: * Speaking logging messages:: * Buffering logging messages and outputting them conditionally:: * Formatting times using UTC (GMT) via configuration: Formatting times using UTC GMT via configuration. * Using a context manager for selective logging:: * A CLI application starter template:: * A Qt GUI for logging::  File: python.info, Node: Using logging in multiple modules, Next: Logging from multiple threads, Up: Logging Cookbook 10.7.1 Using logging in multiple modules ---------------------------------------- Multiple calls to ‘logging.getLogger('someLogger')’ return a reference to the same logger object. This is true not only within the same module, but also across modules as long as it is in the same Python interpreter process. It is true for references to the same object; additionally, application code can define and configure a parent logger in one module and create (but not configure) a child logger in a separate module, and all logger calls to the child will pass up to the parent. Here is a main module: import logging import auxiliary_module # create logger with 'spam_application' logger = logging.getLogger('spam_application') logger.setLevel(logging.DEBUG) # create file handler which logs even debug messages fh = logging.FileHandler('spam.log') fh.setLevel(logging.DEBUG) # create console handler with a higher log level ch = logging.StreamHandler() ch.setLevel(logging.ERROR) # create formatter and add it to the handlers formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') fh.setFormatter(formatter) ch.setFormatter(formatter) # add the handlers to the logger logger.addHandler(fh) logger.addHandler(ch) logger.info('creating an instance of auxiliary_module.Auxiliary') a = auxiliary_module.Auxiliary() logger.info('created an instance of auxiliary_module.Auxiliary') logger.info('calling auxiliary_module.Auxiliary.do_something') a.do_something() logger.info('finished auxiliary_module.Auxiliary.do_something') logger.info('calling auxiliary_module.some_function()') auxiliary_module.some_function() logger.info('done with auxiliary_module.some_function()') Here is the auxiliary module: import logging # create logger module_logger = logging.getLogger('spam_application.auxiliary') class Auxiliary: def __init__(self): self.logger = logging.getLogger('spam_application.auxiliary.Auxiliary') self.logger.info('creating an instance of Auxiliary') def do_something(self): self.logger.info('doing something') a = 1 + 1 self.logger.info('done doing something') def some_function(): module_logger.info('received a call to "some_function"') The output looks like this: 2005-03-23 23:47:11,663 - spam_application - INFO - creating an instance of auxiliary_module.Auxiliary 2005-03-23 23:47:11,665 - spam_application.auxiliary.Auxiliary - INFO - creating an instance of Auxiliary 2005-03-23 23:47:11,665 - spam_application - INFO - created an instance of auxiliary_module.Auxiliary 2005-03-23 23:47:11,668 - spam_application - INFO - calling auxiliary_module.Auxiliary.do_something 2005-03-23 23:47:11,668 - spam_application.auxiliary.Auxiliary - INFO - doing something 2005-03-23 23:47:11,669 - spam_application.auxiliary.Auxiliary - INFO - done doing something 2005-03-23 23:47:11,670 - spam_application - INFO - finished auxiliary_module.Auxiliary.do_something 2005-03-23 23:47:11,671 - spam_application - INFO - calling auxiliary_module.some_function() 2005-03-23 23:47:11,672 - spam_application.auxiliary - INFO - received a call to 'some_function' 2005-03-23 23:47:11,673 - spam_application - INFO - done with auxiliary_module.some_function()  File: python.info, Node: Logging from multiple threads, Next: Multiple handlers and formatters, Prev: Using logging in multiple modules, Up: Logging Cookbook 10.7.2 Logging from multiple threads ------------------------------------ Logging from multiple threads requires no special effort. The following example shows logging from the main (initial) thread and another thread: import logging import threading import time def worker(arg): while not arg['stop']: logging.debug('Hi from myfunc') time.sleep(0.5) def main(): logging.basicConfig(level=logging.DEBUG, format='%(relativeCreated)6d %(threadName)s %(message)s') info = {'stop': False} thread = threading.Thread(target=worker, args=(info,)) thread.start() while True: try: logging.debug('Hello from main') time.sleep(0.75) except KeyboardInterrupt: info['stop'] = True break thread.join() if __name__ == '__main__': main() When run, the script should print something like the following: 0 Thread-1 Hi from myfunc 3 MainThread Hello from main 505 Thread-1 Hi from myfunc 755 MainThread Hello from main 1007 Thread-1 Hi from myfunc 1507 MainThread Hello from main 1508 Thread-1 Hi from myfunc 2010 Thread-1 Hi from myfunc 2258 MainThread Hello from main 2512 Thread-1 Hi from myfunc 3009 MainThread Hello from main 3013 Thread-1 Hi from myfunc 3515 Thread-1 Hi from myfunc 3761 MainThread Hello from main 4017 Thread-1 Hi from myfunc 4513 MainThread Hello from main 4518 Thread-1 Hi from myfunc This shows the logging output interspersed as one might expect. This approach works for more threads than shown here, of course.  File: python.info, Node: Multiple handlers and formatters, Next: Logging to multiple destinations, Prev: Logging from multiple threads, Up: Logging Cookbook 10.7.3 Multiple handlers and formatters --------------------------------------- Loggers are plain Python objects. The *note addHandler(): 1d6a. method has no minimum or maximum quota for the number of handlers you may add. Sometimes it will be beneficial for an application to log all messages of all severities to a text file while simultaneously logging errors or above to the console. To set this up, simply configure the appropriate handlers. The logging calls in the application code will remain unchanged. Here is a slight modification to the previous simple module-based configuration example: import logging logger = logging.getLogger('simple_example') logger.setLevel(logging.DEBUG) # create file handler which logs even debug messages fh = logging.FileHandler('spam.log') fh.setLevel(logging.DEBUG) # create console handler with a higher log level ch = logging.StreamHandler() ch.setLevel(logging.ERROR) # create formatter and add it to the handlers formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') ch.setFormatter(formatter) fh.setFormatter(formatter) # add the handlers to logger logger.addHandler(ch) logger.addHandler(fh) # 'application' code logger.debug('debug message') logger.info('info message') logger.warning('warn message') logger.error('error message') logger.critical('critical message') Notice that the ‘application’ code does not care about multiple handlers. All that changed was the addition and configuration of a new handler named `fh'. The ability to create new handlers with higher- or lower-severity filters can be very helpful when writing and testing an application. Instead of using many ‘print’ statements for debugging, use ‘logger.debug’: Unlike the print statements, which you will have to delete or comment out later, the logger.debug statements can remain intact in the source code and remain dormant until you need them again. At that time, the only change that needs to happen is to modify the severity level of the logger and/or handler to debug.  File: python.info, Node: Logging to multiple destinations, Next: Configuration server example, Prev: Multiple handlers and formatters, Up: Logging Cookbook 10.7.4 Logging to multiple destinations --------------------------------------- Let’s say you want to log to console and file with different message formats and in differing circumstances. Say you want to log messages with levels of DEBUG and higher to file, and those messages at level INFO and higher to the console. Let’s also assume that the file should contain timestamps, but the console messages should not. Here’s how you can achieve this: import logging # set up logging to file - see previous section for more details logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s', datefmt='%m-%d %H:%M', filename='/temp/myapp.log', filemode='w') # define a Handler which writes INFO messages or higher to the sys.stderr console = logging.StreamHandler() console.setLevel(logging.INFO) # set a format which is simpler for console use formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s') # tell the handler to use this format console.setFormatter(formatter) # add the handler to the root logger logging.getLogger('').addHandler(console) # Now, we can log to the root logger, or any other logger. First the root... logging.info('Jackdaws love my big sphinx of quartz.') # Now, define a couple of other loggers which might represent areas in your # application: logger1 = logging.getLogger('myapp.area1') logger2 = logging.getLogger('myapp.area2') logger1.debug('Quick zephyrs blow, vexing daft Jim.') logger1.info('How quickly daft jumping zebras vex.') logger2.warning('Jail zesty vixen who grabbed pay from quack.') logger2.error('The five boxing wizards jump quickly.') When you run this, on the console you will see root : INFO Jackdaws love my big sphinx of quartz. myapp.area1 : INFO How quickly daft jumping zebras vex. myapp.area2 : WARNING Jail zesty vixen who grabbed pay from quack. myapp.area2 : ERROR The five boxing wizards jump quickly. and in the file you will see something like 10-22 22:19 root INFO Jackdaws love my big sphinx of quartz. 10-22 22:19 myapp.area1 DEBUG Quick zephyrs blow, vexing daft Jim. 10-22 22:19 myapp.area1 INFO How quickly daft jumping zebras vex. 10-22 22:19 myapp.area2 WARNING Jail zesty vixen who grabbed pay from quack. 10-22 22:19 myapp.area2 ERROR The five boxing wizards jump quickly. As you can see, the DEBUG message only shows up in the file. The other messages are sent to both destinations. This example uses console and file handlers, but you can use any number and combination of handlers you choose.  File: python.info, Node: Configuration server example, Next: Dealing with handlers that block, Prev: Logging to multiple destinations, Up: Logging Cookbook 10.7.5 Configuration server example ----------------------------------- Here is an example of a module using the logging configuration server: import logging import logging.config import time import os # read initial config file logging.config.fileConfig('logging.conf') # create and start listener on port 9999 t = logging.config.listen(9999) t.start() logger = logging.getLogger('simpleExample') try: # loop through logging calls to see the difference # new configurations make, until Ctrl+C is pressed while True: logger.debug('debug message') logger.info('info message') logger.warning('warn message') logger.error('error message') logger.critical('critical message') time.sleep(5) except KeyboardInterrupt: # cleanup logging.config.stopListening() t.join() And here is a script that takes a filename and sends that file to the server, properly preceded with the binary-encoded length, as the new logging configuration: #!/usr/bin/env python import socket, sys, struct with open(sys.argv[1], 'rb') as f: data_to_send = f.read() HOST = 'localhost' PORT = 9999 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print('connecting...') s.connect((HOST, PORT)) print('sending config...') s.send(struct.pack('>L', len(data_to_send))) s.send(data_to_send) s.close() print('complete')  File: python.info, Node: Dealing with handlers that block, Next: Sending and receiving logging events across a network, Prev: Configuration server example, Up: Logging Cookbook 10.7.6 Dealing with handlers that block --------------------------------------- Sometimes you have to get your logging handlers to do their work without blocking the thread you’re logging from. This is common in Web applications, though of course it also occurs in other scenarios. A common culprit which demonstrates sluggish behaviour is the *note SMTPHandler: 1e09.: sending emails can take a long time, for a number of reasons outside the developer’s control (for example, a poorly performing mail or network infrastructure). But almost any network-based handler can block: Even a *note SocketHandler: 86f. operation may do a DNS query under the hood which is too slow (and this query can be deep in the socket library code, below the Python layer, and outside your control). One solution is to use a two-part approach. For the first part, attach only a *note QueueHandler: 1e1c. to those loggers which are accessed from performance-critical threads. They simply write to their queue, which can be sized to a large enough capacity or initialized with no upper bound to their size. The write to the queue will typically be accepted quickly, though you will probably need to catch the *note queue.Full: 20a1. exception as a precaution in your code. If you are a library developer who has performance-critical threads in their code, be sure to document this (together with a suggestion to attach only ‘QueueHandlers’ to your loggers) for the benefit of other developers who will use your code. The second part of the solution is *note QueueListener: 712, which has been designed as the counterpart to *note QueueHandler: 1e1c. A *note QueueListener: 712. is very simple: it’s passed a queue and some handlers, and it fires up an internal thread which listens to its queue for LogRecords sent from ‘QueueHandlers’ (or any other source of ‘LogRecords’, for that matter). The ‘LogRecords’ are removed from the queue and passed to the handlers for processing. The advantage of having a separate *note QueueListener: 712. class is that you can use the same instance to service multiple ‘QueueHandlers’. This is more resource-friendly than, say, having threaded versions of the existing handler classes, which would eat up one thread per handler for no particular benefit. An example of using these two classes follows (imports omitted): que = queue.Queue(-1) # no limit on size queue_handler = QueueHandler(que) handler = logging.StreamHandler() listener = QueueListener(que, handler) root = logging.getLogger() root.addHandler(queue_handler) formatter = logging.Formatter('%(threadName)s: %(message)s') handler.setFormatter(formatter) listener.start() # The log output will display the thread which generated # the event (the main thread) rather than the internal # thread which monitors the internal queue. This is what # you want to happen. root.warning('Look out!') listener.stop() which, when run, will produce: MainThread: Look out! Changed in version 3.5: Prior to Python 3.5, the *note QueueListener: 712. always passed every message received from the queue to every handler it was initialized with. (This was because it was assumed that level filtering was all done on the other side, where the queue is filled.) From 3.5 onwards, this behaviour can be changed by passing a keyword argument ‘respect_handler_level=True’ to the listener’s constructor. When this is done, the listener compares the level of each message with the handler’s level, and only passes a message to a handler if it’s appropriate to do so.  File: python.info, Node: Sending and receiving logging events across a network, Next: Adding contextual information to your logging output, Prev: Dealing with handlers that block, Up: Logging Cookbook 10.7.7 Sending and receiving logging events across a network ------------------------------------------------------------ Let’s say you want to send logging events across a network, and handle them at the receiving end. A simple way of doing this is attaching a *note SocketHandler: 86f. instance to the root logger at the sending end: import logging, logging.handlers rootLogger = logging.getLogger('') rootLogger.setLevel(logging.DEBUG) socketHandler = logging.handlers.SocketHandler('localhost', logging.handlers.DEFAULT_TCP_LOGGING_PORT) # don't bother with a formatter, since a socket handler sends the event as # an unformatted pickle rootLogger.addHandler(socketHandler) # Now, we can log to the root logger, or any other logger. First the root... logging.info('Jackdaws love my big sphinx of quartz.') # Now, define a couple of other loggers which might represent areas in your # application: logger1 = logging.getLogger('myapp.area1') logger2 = logging.getLogger('myapp.area2') logger1.debug('Quick zephyrs blow, vexing daft Jim.') logger1.info('How quickly daft jumping zebras vex.') logger2.warning('Jail zesty vixen who grabbed pay from quack.') logger2.error('The five boxing wizards jump quickly.') At the receiving end, you can set up a receiver using the *note socketserver: f0. module. Here is a basic working example: import pickle import logging import logging.handlers import socketserver import struct class LogRecordStreamHandler(socketserver.StreamRequestHandler): """Handler for a streaming logging request. This basically logs the record using whatever logging policy is configured locally. """ def handle(self): """ Handle multiple requests - each expected to be a 4-byte length, followed by the LogRecord in pickle format. Logs the record according to whatever policy is configured locally. """ while True: chunk = self.connection.recv(4) if len(chunk) < 4: break slen = struct.unpack('>L', chunk)[0] chunk = self.connection.recv(slen) while len(chunk) < slen: chunk = chunk + self.connection.recv(slen - len(chunk)) obj = self.unPickle(chunk) record = logging.makeLogRecord(obj) self.handleLogRecord(record) def unPickle(self, data): return pickle.loads(data) def handleLogRecord(self, record): # if a name is specified, we use the named logger rather than the one # implied by the record. if self.server.logname is not None: name = self.server.logname else: name = record.name logger = logging.getLogger(name) # N.B. EVERY record gets logged. This is because Logger.handle # is normally called AFTER logger-level filtering. If you want # to do filtering, do it at the client end to save wasting # cycles and network bandwidth! logger.handle(record) class LogRecordSocketReceiver(socketserver.ThreadingTCPServer): """ Simple TCP socket-based logging receiver suitable for testing. """ allow_reuse_address = True def __init__(self, host='localhost', port=logging.handlers.DEFAULT_TCP_LOGGING_PORT, handler=LogRecordStreamHandler): socketserver.ThreadingTCPServer.__init__(self, (host, port), handler) self.abort = 0 self.timeout = 1 self.logname = None def serve_until_stopped(self): import select abort = 0 while not abort: rd, wr, ex = select.select([self.socket.fileno()], [], [], self.timeout) if rd: self.handle_request() abort = self.abort def main(): logging.basicConfig( format='%(relativeCreated)5d %(name)-15s %(levelname)-8s %(message)s') tcpserver = LogRecordSocketReceiver() print('About to start TCP server...') tcpserver.serve_until_stopped() if __name__ == '__main__': main() First run the server, and then the client. On the client side, nothing is printed on the console; on the server side, you should see something like: About to start TCP server... 59 root INFO Jackdaws love my big sphinx of quartz. 59 myapp.area1 DEBUG Quick zephyrs blow, vexing daft Jim. 69 myapp.area1 INFO How quickly daft jumping zebras vex. 69 myapp.area2 WARNING Jail zesty vixen who grabbed pay from quack. 69 myapp.area2 ERROR The five boxing wizards jump quickly. Note that there are some security issues with pickle in some scenarios. If these affect you, you can use an alternative serialization scheme by overriding the ‘makePickle()’ method and implementing your alternative there, as well as adapting the above script to use your alternative serialization.  File: python.info, Node: Adding contextual information to your logging output, Next: Logging to a single file from multiple processes, Prev: Sending and receiving logging events across a network, Up: Logging Cookbook 10.7.8 Adding contextual information to your logging output ----------------------------------------------------------- Sometimes you want logging output to contain contextual information in addition to the parameters passed to the logging call. For example, in a networked application, it may be desirable to log client-specific information in the log (e.g. remote client’s username, or IP address). Although you could use the `extra' parameter to achieve this, it’s not always convenient to pass the information in this way. While it might be tempting to create ‘Logger’ instances on a per-connection basis, this is not a good idea because these instances are not garbage collected. While this is not a problem in practice, when the number of ‘Logger’ instances is dependent on the level of granularity you want to use in logging an application, it could be hard to manage if the number of ‘Logger’ instances becomes effectively unbounded. * Menu: * Using LoggerAdapters to impart contextual information:: * Using Filters to impart contextual information::  File: python.info, Node: Using LoggerAdapters to impart contextual information, Next: Using Filters to impart contextual information, Up: Adding contextual information to your logging output 10.7.8.1 Using LoggerAdapters to impart contextual information .............................................................. An easy way in which you can pass contextual information to be output along with logging event information is to use the ‘LoggerAdapter’ class. This class is designed to look like a ‘Logger’, so that you can call ‘debug()’, ‘info()’, ‘warning()’, ‘error()’, ‘exception()’, ‘critical()’ and ‘log()’. These methods have the same signatures as their counterparts in ‘Logger’, so you can use the two types of instances interchangeably. When you create an instance of ‘LoggerAdapter’, you pass it a ‘Logger’ instance and a dict-like object which contains your contextual information. When you call one of the logging methods on an instance of ‘LoggerAdapter’, it delegates the call to the underlying instance of ‘Logger’ passed to its constructor, and arranges to pass the contextual information in the delegated call. Here’s a snippet from the code of ‘LoggerAdapter’: def debug(self, msg, /, *args, **kwargs): """ Delegate a debug call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.debug(msg, *args, **kwargs) The ‘process()’ method of ‘LoggerAdapter’ is where the contextual information is added to the logging output. It’s passed the message and keyword arguments of the logging call, and it passes back (potentially) modified versions of these to use in the call to the underlying logger. The default implementation of this method leaves the message alone, but inserts an ‘extra’ key in the keyword argument whose value is the dict-like object passed to the constructor. Of course, if you had passed an ‘extra’ keyword argument in the call to the adapter, it will be silently overwritten. The advantage of using ‘extra’ is that the values in the dict-like object are merged into the ‘LogRecord’ instance’s __dict__, allowing you to use customized strings with your ‘Formatter’ instances which know about the keys of the dict-like object. If you need a different method, e.g. if you want to prepend or append the contextual information to the message string, you just need to subclass ‘LoggerAdapter’ and override ‘process()’ to do what you need. Here is a simple example: class CustomAdapter(logging.LoggerAdapter): """ This example adapter expects the passed in dict-like object to have a 'connid' key, whose value in brackets is prepended to the log message. """ def process(self, msg, kwargs): return '[%s] %s' % (self.extra['connid'], msg), kwargs which you can use like this: logger = logging.getLogger(__name__) adapter = CustomAdapter(logger, {'connid': some_conn_id}) Then any events that you log to the adapter will have the value of ‘some_conn_id’ prepended to the log messages. * Menu: * Using objects other than dicts to pass contextual information::  File: python.info, Node: Using objects other than dicts to pass contextual information, Up: Using LoggerAdapters to impart contextual information 10.7.8.2 Using objects other than dicts to pass contextual information ...................................................................... You don’t need to pass an actual dict to a ‘LoggerAdapter’ - you could pass an instance of a class which implements ‘__getitem__’ and ‘__iter__’ so that it looks like a dict to logging. This would be useful if you want to generate values dynamically (whereas the values in a dict would be constant).  File: python.info, Node: Using Filters to impart contextual information, Prev: Using LoggerAdapters to impart contextual information, Up: Adding contextual information to your logging output 10.7.8.3 Using Filters to impart contextual information ....................................................... You can also add contextual information to log output using a user-defined ‘Filter’. ‘Filter’ instances are allowed to modify the ‘LogRecords’ passed to them, including adding additional attributes which can then be output using a suitable format string, or if needed a custom ‘Formatter’. For example in a web application, the request being processed (or at least, the interesting parts of it) can be stored in a threadlocal (*note threading.local: 1fdc.) variable, and then accessed from a ‘Filter’ to add, say, information from the request - say, the remote IP address and remote user’s username - to the ‘LogRecord’, using the attribute names ‘ip’ and ‘user’ as in the ‘LoggerAdapter’ example above. In that case, the same format string can be used to get similar output to that shown above. Here’s an example script: import logging from random import choice class ContextFilter(logging.Filter): """ This is a filter which injects contextual information into the log. Rather than use actual contextual information, we just use random data in this demo. """ USERS = ['jim', 'fred', 'sheila'] IPS = ['123.231.231.123', '127.0.0.1', '192.168.0.1'] def filter(self, record): record.ip = choice(ContextFilter.IPS) record.user = choice(ContextFilter.USERS) return True if __name__ == '__main__': levels = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL) logging.basicConfig(level=logging.DEBUG, format='%(asctime)-15s %(name)-5s %(levelname)-8s IP: %(ip)-15s User: %(user)-8s %(message)s') a1 = logging.getLogger('a.b.c') a2 = logging.getLogger('d.e.f') f = ContextFilter() a1.addFilter(f) a2.addFilter(f) a1.debug('A debug message') a1.info('An info message with %s', 'some parameters') for x in range(10): lvl = choice(levels) lvlname = logging.getLevelName(lvl) a2.log(lvl, 'A message at %s level with %d %s', lvlname, 2, 'parameters') which, when run, produces something like: 2010-09-06 22:38:15,292 a.b.c DEBUG IP: 123.231.231.123 User: fred A debug message 2010-09-06 22:38:15,300 a.b.c INFO IP: 192.168.0.1 User: sheila An info message with some parameters 2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 127.0.0.1 User: sheila A message at CRITICAL level with 2 parameters 2010-09-06 22:38:15,300 d.e.f ERROR IP: 127.0.0.1 User: jim A message at ERROR level with 2 parameters 2010-09-06 22:38:15,300 d.e.f DEBUG IP: 127.0.0.1 User: sheila A message at DEBUG level with 2 parameters 2010-09-06 22:38:15,300 d.e.f ERROR IP: 123.231.231.123 User: fred A message at ERROR level with 2 parameters 2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 192.168.0.1 User: jim A message at CRITICAL level with 2 parameters 2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 127.0.0.1 User: sheila A message at CRITICAL level with 2 parameters 2010-09-06 22:38:15,300 d.e.f DEBUG IP: 192.168.0.1 User: jim A message at DEBUG level with 2 parameters 2010-09-06 22:38:15,301 d.e.f ERROR IP: 127.0.0.1 User: sheila A message at ERROR level with 2 parameters 2010-09-06 22:38:15,301 d.e.f DEBUG IP: 123.231.231.123 User: fred A message at DEBUG level with 2 parameters 2010-09-06 22:38:15,301 d.e.f INFO IP: 123.231.231.123 User: fred A message at INFO level with 2 parameters  File: python.info, Node: Logging to a single file from multiple processes, Next: Using file rotation, Prev: Adding contextual information to your logging output, Up: Logging Cookbook 10.7.9 Logging to a single file from multiple processes ------------------------------------------------------- Although logging is thread-safe, and logging to a single file from multiple threads in a single process `is' supported, logging to a single file from `multiple processes' is `not' supported, because there is no standard way to serialize access to a single file across multiple processes in Python. If you need to log to a single file from multiple processes, one way of doing this is to have all the processes log to a ‘SocketHandler’, and have a separate process which implements a socket server which reads from the socket and logs to file. (If you prefer, you can dedicate one thread in one of the existing processes to perform this function.) *note This section: 3ec9. documents this approach in more detail and includes a working socket receiver which can be used as a starting point for you to adapt in your own applications. You could also write your own handler which uses the *note Lock: 2082. class from the *note multiprocessing: b7. module to serialize access to the file from your processes. The existing ‘FileHandler’ and subclasses do not make use of *note multiprocessing: b7. at present, though they may do so in the future. Note that at present, the *note multiprocessing: b7. module does not provide working lock functionality on all platforms (see ‘https://bugs.python.org/issue3770’). Alternatively, you can use a ‘Queue’ and a *note QueueHandler: 1e1c. to send all logging events to one of the processes in your multi-process application. The following example script demonstrates how you can do this; in the example a separate listener process listens for events sent by other processes and logs them according to its own logging configuration. Although the example only demonstrates one way of doing it (for example, you may want to use a listener thread rather than a separate listener process – the implementation would be analogous) it does allow for completely different logging configurations for the listener and the other processes in your application, and can be used as the basis for code meeting your own specific requirements: # You'll need these imports in your own code import logging import logging.handlers import multiprocessing # Next two import lines for this demo only from random import choice, random import time # # Because you'll want to define the logging configurations for listener and workers, the # listener and worker process functions take a configurer parameter which is a callable # for configuring logging for that process. These functions are also passed the queue, # which they use for communication. # # In practice, you can configure the listener however you want, but note that in this # simple example, the listener does not apply level or filter logic to received records. # In practice, you would probably want to do this logic in the worker processes, to avoid # sending events which would be filtered out between processes. # # The size of the rotated files is made small so you can see the results easily. def listener_configurer(): root = logging.getLogger() h = logging.handlers.RotatingFileHandler('mptest.log', 'a', 300, 10) f = logging.Formatter('%(asctime)s %(processName)-10s %(name)s %(levelname)-8s %(message)s') h.setFormatter(f) root.addHandler(h) # This is the listener process top-level loop: wait for logging events # (LogRecords)on the queue and handle them, quit when you get a None for a # LogRecord. def listener_process(queue, configurer): configurer() while True: try: record = queue.get() if record is None: # We send this as a sentinel to tell the listener to quit. break logger = logging.getLogger(record.name) logger.handle(record) # No level or filter logic applied - just do it! except Exception: import sys, traceback print('Whoops! Problem:', file=sys.stderr) traceback.print_exc(file=sys.stderr) # Arrays used for random selections in this demo LEVELS = [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL] LOGGERS = ['a.b.c', 'd.e.f'] MESSAGES = [ 'Random message #1', 'Random message #2', 'Random message #3', ] # The worker configuration is done at the start of the worker process run. # Note that on Windows you can't rely on fork semantics, so each process # will run the logging configuration code when it starts. def worker_configurer(queue): h = logging.handlers.QueueHandler(queue) # Just the one handler needed root = logging.getLogger() root.addHandler(h) # send all messages, for demo; no other level or filter logic applied. root.setLevel(logging.DEBUG) # This is the worker process top-level loop, which just logs ten events with # random intervening delays before terminating. # The print messages are just so you know it's doing something! def worker_process(queue, configurer): configurer(queue) name = multiprocessing.current_process().name print('Worker started: %s' % name) for i in range(10): time.sleep(random()) logger = logging.getLogger(choice(LOGGERS)) level = choice(LEVELS) message = choice(MESSAGES) logger.log(level, message) print('Worker finished: %s' % name) # Here's where the demo gets orchestrated. Create the queue, create and start # the listener, create ten workers and start them, wait for them to finish, # then send a None to the queue to tell the listener to finish. def main(): queue = multiprocessing.Queue(-1) listener = multiprocessing.Process(target=listener_process, args=(queue, listener_configurer)) listener.start() workers = [] for i in range(10): worker = multiprocessing.Process(target=worker_process, args=(queue, worker_configurer)) workers.append(worker) worker.start() for w in workers: w.join() queue.put_nowait(None) listener.join() if __name__ == '__main__': main() A variant of the above script keeps the logging in the main process, in a separate thread: import logging import logging.config import logging.handlers from multiprocessing import Process, Queue import random import threading import time def logger_thread(q): while True: record = q.get() if record is None: break logger = logging.getLogger(record.name) logger.handle(record) def worker_process(q): qh = logging.handlers.QueueHandler(q) root = logging.getLogger() root.setLevel(logging.DEBUG) root.addHandler(qh) levels = [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL] loggers = ['foo', 'foo.bar', 'foo.bar.baz', 'spam', 'spam.ham', 'spam.ham.eggs'] for i in range(100): lvl = random.choice(levels) logger = logging.getLogger(random.choice(loggers)) logger.log(lvl, 'Message no. %d', i) if __name__ == '__main__': q = Queue() d = { 'version': 1, 'formatters': { 'detailed': { 'class': 'logging.Formatter', 'format': '%(asctime)s %(name)-15s %(levelname)-8s %(processName)-10s %(message)s' } }, 'handlers': { 'console': { 'class': 'logging.StreamHandler', 'level': 'INFO', }, 'file': { 'class': 'logging.FileHandler', 'filename': 'mplog.log', 'mode': 'w', 'formatter': 'detailed', }, 'foofile': { 'class': 'logging.FileHandler', 'filename': 'mplog-foo.log', 'mode': 'w', 'formatter': 'detailed', }, 'errors': { 'class': 'logging.FileHandler', 'filename': 'mplog-errors.log', 'mode': 'w', 'level': 'ERROR', 'formatter': 'detailed', }, }, 'loggers': { 'foo': { 'handlers': ['foofile'] } }, 'root': { 'level': 'DEBUG', 'handlers': ['console', 'file', 'errors'] }, } workers = [] for i in range(5): wp = Process(target=worker_process, name='worker %d' % (i + 1), args=(q,)) workers.append(wp) wp.start() logging.config.dictConfig(d) lp = threading.Thread(target=logger_thread, args=(q,)) lp.start() # At this point, the main process could do some useful work of its own # Once it's done that, it can wait for the workers to terminate... for wp in workers: wp.join() # And now tell the logging thread to finish up, too q.put(None) lp.join() This variant shows how you can e.g. apply configuration for particular loggers - e.g. the ‘foo’ logger has a special handler which stores all events in the ‘foo’ subsystem in a file ‘mplog-foo.log’. This will be used by the logging machinery in the main process (even though the logging events are generated in the worker processes) to direct the messages to the appropriate destinations. * Menu: * Using concurrent.futures.ProcessPoolExecutor: Using concurrent futures ProcessPoolExecutor.  File: python.info, Node: Using concurrent futures ProcessPoolExecutor, Up: Logging to a single file from multiple processes 10.7.9.1 Using concurrent.futures.ProcessPoolExecutor ..................................................... If you want to use *note concurrent.futures.ProcessPoolExecutor: 2a4. to start your worker processes, you need to create the queue slightly differently. Instead of queue = multiprocessing.Queue(-1) you should use queue = multiprocessing.Manager().Queue(-1) # also works with the examples above and you can then replace the worker creation from this: workers = [] for i in range(10): worker = multiprocessing.Process(target=worker_process, args=(queue, worker_configurer)) workers.append(worker) worker.start() for w in workers: w.join() to this (remembering to first import *note concurrent.futures: 22.): with concurrent.futures.ProcessPoolExecutor(max_workers=10) as executor: for i in range(10): executor.submit(worker_process, queue, worker_configurer)  File: python.info, Node: Using file rotation, Next: Use of alternative formatting styles, Prev: Logging to a single file from multiple processes, Up: Logging Cookbook 10.7.10 Using file rotation --------------------------- Sometimes you want to let a log file grow to a certain size, then open a new file and log to that. You may want to keep a certain number of these files, and when that many files have been created, rotate the files so that the number of files and the size of the files both remain bounded. For this usage pattern, the logging package provides a ‘RotatingFileHandler’: import glob import logging import logging.handlers LOG_FILENAME = 'logging_rotatingfile_example.out' # Set up a specific logger with our desired output level my_logger = logging.getLogger('MyLogger') my_logger.setLevel(logging.DEBUG) # Add the log message handler to the logger handler = logging.handlers.RotatingFileHandler( LOG_FILENAME, maxBytes=20, backupCount=5) my_logger.addHandler(handler) # Log some messages for i in range(20): my_logger.debug('i = %d' % i) # See what files are created logfiles = glob.glob('%s*' % LOG_FILENAME) for filename in logfiles: print(filename) The result should be 6 separate files, each with part of the log history for the application: logging_rotatingfile_example.out logging_rotatingfile_example.out.1 logging_rotatingfile_example.out.2 logging_rotatingfile_example.out.3 logging_rotatingfile_example.out.4 logging_rotatingfile_example.out.5 The most current file is always ‘logging_rotatingfile_example.out’, and each time it reaches the size limit it is renamed with the suffix ‘.1’. Each of the existing backup files is renamed to increment the suffix (‘.1’ becomes ‘.2’, etc.) and the ‘.6’ file is erased. Obviously this example sets the log length much too small as an extreme example. You would want to set `maxBytes' to an appropriate value.  File: python.info, Node: Use of alternative formatting styles, Next: Customizing LogRecord, Prev: Using file rotation, Up: Logging Cookbook 10.7.11 Use of alternative formatting styles -------------------------------------------- When logging was added to the Python standard library, the only way of formatting messages with variable content was to use the %-formatting method. Since then, Python has gained two new formatting approaches: *note string.Template: 3eb. (added in Python 2.4) and *note str.format(): 4da. (added in Python 2.6). Logging (as of 3.2) provides improved support for these two additional formatting styles. The ‘Formatter’ class been enhanced to take an additional, optional keyword parameter named ‘style’. This defaults to ‘'%'’, but other possible values are ‘'{'’ and ‘'$'’, which correspond to the other two formatting styles. Backwards compatibility is maintained by default (as you would expect), but by explicitly specifying a style parameter, you get the ability to specify format strings which work with *note str.format(): 4da. or *note string.Template: 3eb. Here’s an example console session to show the possibilities: >>> import logging >>> root = logging.getLogger() >>> root.setLevel(logging.DEBUG) >>> handler = logging.StreamHandler() >>> bf = logging.Formatter('{asctime} {name} {levelname:8s} {message}', ... style='{') >>> handler.setFormatter(bf) >>> root.addHandler(handler) >>> logger = logging.getLogger('foo.bar') >>> logger.debug('This is a DEBUG message') 2010-10-28 15:11:55,341 foo.bar DEBUG This is a DEBUG message >>> logger.critical('This is a CRITICAL message') 2010-10-28 15:12:11,526 foo.bar CRITICAL This is a CRITICAL message >>> df = logging.Formatter('$asctime $name ${levelname} $message', ... style='$') >>> handler.setFormatter(df) >>> logger.debug('This is a DEBUG message') 2010-10-28 15:13:06,924 foo.bar DEBUG This is a DEBUG message >>> logger.critical('This is a CRITICAL message') 2010-10-28 15:13:11,494 foo.bar CRITICAL This is a CRITICAL message >>> Note that the formatting of logging messages for final output to logs is completely independent of how an individual logging message is constructed. That can still use %-formatting, as shown here: >>> logger.error('This is an%s %s %s', 'other,', 'ERROR,', 'message') 2010-10-28 15:19:29,833 foo.bar ERROR This is another, ERROR, message >>> Logging calls (‘logger.debug()’, ‘logger.info()’ etc.) only take positional parameters for the actual logging message itself, with keyword parameters used only for determining options for how to handle the actual logging call (e.g. the ‘exc_info’ keyword parameter to indicate that traceback information should be logged, or the ‘extra’ keyword parameter to indicate additional contextual information to be added to the log). So you cannot directly make logging calls using *note str.format(): 4da. or *note string.Template: 3eb. syntax, because internally the logging package uses %-formatting to merge the format string and the variable arguments. There would be no changing this while preserving backward compatibility, since all logging calls which are out there in existing code will be using %-format strings. There is, however, a way that you can use {}- and $- formatting to construct your individual log messages. Recall that for a message you can use an arbitrary object as a message format string, and that the logging package will call ‘str()’ on that object to get the actual format string. Consider the following two classes: class BraceMessage: def __init__(self, fmt, /, *args, **kwargs): self.fmt = fmt self.args = args self.kwargs = kwargs def __str__(self): return self.fmt.format(*self.args, **self.kwargs) class DollarMessage: def __init__(self, fmt, /, **kwargs): self.fmt = fmt self.kwargs = kwargs def __str__(self): from string import Template return Template(self.fmt).substitute(**self.kwargs) Either of these can be used in place of a format string, to allow {}- or $-formatting to be used to build the actual “message” part which appears in the formatted log output in place of “%(message)s” or “{message}” or “$message”. It’s a little unwieldy to use the class names whenever you want to log something, but it’s quite palatable if you use an alias such as __ (double underscore — not to be confused with _, the single underscore used as a synonym/alias for *note gettext.gettext(): dcd. or its brethren). The above classes are not included in Python, though they’re easy enough to copy and paste into your own code. They can be used as follows (assuming that they’re declared in a module called ‘wherever’): >>> from wherever import BraceMessage as __ >>> print(__('Message with {0} {name}', 2, name='placeholders')) Message with 2 placeholders >>> class Point: pass ... >>> p = Point() >>> p.x = 0.5 >>> p.y = 0.5 >>> print(__('Message with coordinates: ({point.x:.2f}, {point.y:.2f})', ... point=p)) Message with coordinates: (0.50, 0.50) >>> from wherever import DollarMessage as __ >>> print(__('Message with $num $what', num=2, what='placeholders')) Message with 2 placeholders >>> While the above examples use ‘print()’ to show how the formatting works, you would of course use ‘logger.debug()’ or similar to actually log using this approach. One thing to note is that you pay no significant performance penalty with this approach: the actual formatting happens not when you make the logging call, but when (and if) the logged message is actually about to be output to a log by a handler. So the only slightly unusual thing which might trip you up is that the parentheses go around the format string and the arguments, not just the format string. That’s because the __ notation is just syntax sugar for a constructor call to one of the XXXMessage classes. If you prefer, you can use a ‘LoggerAdapter’ to achieve a similar effect to the above, as in the following example: import logging class Message: def __init__(self, fmt, args): self.fmt = fmt self.args = args def __str__(self): return self.fmt.format(*self.args) class StyleAdapter(logging.LoggerAdapter): def __init__(self, logger, extra=None): super(StyleAdapter, self).__init__(logger, extra or {}) def log(self, level, msg, /, *args, **kwargs): if self.isEnabledFor(level): msg, kwargs = self.process(msg, kwargs) self.logger._log(level, Message(msg, args), (), **kwargs) logger = StyleAdapter(logging.getLogger(__name__)) def main(): logger.debug('Hello, {}', 'world!') if __name__ == '__main__': logging.basicConfig(level=logging.DEBUG) main() The above script should log the message ‘Hello, world!’ when run with Python 3.2 or later.  File: python.info, Node: Customizing LogRecord, Next: Subclassing QueueHandler - a ZeroMQ example, Prev: Use of alternative formatting styles, Up: Logging Cookbook 10.7.12 Customizing ‘LogRecord’ ------------------------------- Every logging event is represented by a *note LogRecord: 906. instance. When an event is logged and not filtered out by a logger’s level, a *note LogRecord: 906. is created, populated with information about the event and then passed to the handlers for that logger (and its ancestors, up to and including the logger where further propagation up the hierarchy is disabled). Before Python 3.2, there were only two places where this creation was done: * *note Logger.makeRecord(): 1d6e, which is called in the normal process of logging an event. This invoked *note LogRecord: 906. directly to create an instance. * *note makeLogRecord(): 1d93, which is called with a dictionary containing attributes to be added to the LogRecord. This is typically invoked when a suitable dictionary has been received over the network (e.g. in pickle form via a *note SocketHandler: 86f, or in JSON form via an *note HTTPHandler: 711.). This has usually meant that if you need to do anything special with a *note LogRecord: 906, you’ve had to do one of the following. * Create your own *note Logger: 3a7. subclass, which overrides *note Logger.makeRecord(): 1d6e, and set it using *note setLoggerClass(): 1da0. before any loggers that you care about are instantiated. * Add a *note Filter: b77. to a logger or handler, which does the necessary special manipulation you need when its *note filter(): 1d8e. method is called. The first approach would be a little unwieldy in the scenario where (say) several different libraries wanted to do different things. Each would attempt to set its own *note Logger: 3a7. subclass, and the one which did this last would win. The second approach works reasonably well for many cases, but does not allow you to e.g. use a specialized subclass of *note LogRecord: 906. Library developers can set a suitable filter on their loggers, but they would have to remember to do this every time they introduced a new logger (which they would do simply by adding new packages or modules and doing logger = logging.getLogger(__name__) at module level). It’s probably one too many things to think about. Developers could also add the filter to a *note NullHandler: c1c. attached to their top-level logger, but this would not be invoked if an application developer attached a handler to a lower-level library logger — so output from that handler would not reflect the intentions of the library developer. In Python 3.2 and later, *note LogRecord: 906. creation is done through a factory, which you can specify. The factory is just a callable you can set with *note setLogRecordFactory(): 1d96, and interrogate with *note getLogRecordFactory(): 1d95. The factory is invoked with the same signature as the *note LogRecord: 906. constructor, as *note LogRecord: 906. is the default setting for the factory. This approach allows a custom factory to control all aspects of LogRecord creation. For example, you could return a subclass, or just add some additional attributes to the record once created, using a pattern similar to this: old_factory = logging.getLogRecordFactory() def record_factory(*args, **kwargs): record = old_factory(*args, **kwargs) record.custom_attribute = 0xdecafbad return record logging.setLogRecordFactory(record_factory) This pattern allows different libraries to chain factories together, and as long as they don’t overwrite each other’s attributes or unintentionally overwrite the attributes provided as standard, there should be no surprises. However, it should be borne in mind that each link in the chain adds run-time overhead to all logging operations, and the technique should only be used when the use of a *note Filter: b77. does not provide the desired result.  File: python.info, Node: Subclassing QueueHandler - a ZeroMQ example, Next: Subclassing QueueListener - a ZeroMQ example, Prev: Customizing LogRecord, Up: Logging Cookbook 10.7.13 Subclassing QueueHandler - a ZeroMQ example --------------------------------------------------- You can use a ‘QueueHandler’ subclass to send messages to other kinds of queues, for example a ZeroMQ ‘publish’ socket. In the example below,the socket is created separately and passed to the handler (as its ‘queue’): import zmq # using pyzmq, the Python binding for ZeroMQ import json # for serializing records portably ctx = zmq.Context() sock = zmq.Socket(ctx, zmq.PUB) # or zmq.PUSH, or other suitable value sock.bind('tcp://*:5556') # or wherever class ZeroMQSocketHandler(QueueHandler): def enqueue(self, record): self.queue.send_json(record.__dict__) handler = ZeroMQSocketHandler(sock) Of course there are other ways of organizing this, for example passing in the data needed by the handler to create the socket: class ZeroMQSocketHandler(QueueHandler): def __init__(self, uri, socktype=zmq.PUB, ctx=None): self.ctx = ctx or zmq.Context() socket = zmq.Socket(self.ctx, socktype) socket.bind(uri) super().__init__(socket) def enqueue(self, record): self.queue.send_json(record.__dict__) def close(self): self.queue.close()  File: python.info, Node: Subclassing QueueListener - a ZeroMQ example, Next: An example dictionary-based configuration, Prev: Subclassing QueueHandler - a ZeroMQ example, Up: Logging Cookbook 10.7.14 Subclassing QueueListener - a ZeroMQ example ---------------------------------------------------- You can also subclass ‘QueueListener’ to get messages from other kinds of queues, for example a ZeroMQ ‘subscribe’ socket. Here’s an example: class ZeroMQSocketListener(QueueListener): def __init__(self, uri, /, *handlers, **kwargs): self.ctx = kwargs.get('ctx') or zmq.Context() socket = zmq.Socket(self.ctx, zmq.SUB) socket.setsockopt_string(zmq.SUBSCRIBE, '') # subscribe to everything socket.connect(uri) super().__init__(socket, *handlers, **kwargs) def dequeue(self): msg = self.queue.recv_json() return logging.makeLogRecord(msg) See also ........ Module *note logging: aa. API reference for the logging module. Module *note logging.config: ab. Configuration API for the logging module. Module *note logging.handlers: ac. Useful handlers included with the logging module. *note A basic logging tutorial: b72. *note A more advanced logging tutorial: b73.  File: python.info, Node: An example dictionary-based configuration, Next: Using a rotator and namer to customize log rotation processing, Prev: Subclassing QueueListener - a ZeroMQ example, Up: Logging Cookbook 10.7.15 An example dictionary-based configuration ------------------------------------------------- Below is an example of a logging configuration dictionary - it’s taken from the documentation on the Django project(1). This dictionary is passed to *note dictConfig(): b2b. to put the configuration into effect: LOGGING = { 'version': 1, 'disable_existing_loggers': True, 'formatters': { 'verbose': { 'format': '%(levelname)s %(asctime)s %(module)s %(process)d %(thread)d %(message)s' }, 'simple': { 'format': '%(levelname)s %(message)s' }, }, 'filters': { 'special': { '()': 'project.logging.SpecialFilter', 'foo': 'bar', } }, 'handlers': { 'null': { 'level':'DEBUG', 'class':'django.utils.log.NullHandler', }, 'console':{ 'level':'DEBUG', 'class':'logging.StreamHandler', 'formatter': 'simple' }, 'mail_admins': { 'level': 'ERROR', 'class': 'django.utils.log.AdminEmailHandler', 'filters': ['special'] } }, 'loggers': { 'django': { 'handlers':['null'], 'propagate': True, 'level':'INFO', }, 'django.request': { 'handlers': ['mail_admins'], 'level': 'ERROR', 'propagate': False, }, 'myproject.custom': { 'handlers': ['console', 'mail_admins'], 'level': 'INFO', 'filters': ['special'] } } } For more information about this configuration, you can see the relevant section(2) of the Django documentation. ---------- Footnotes ---------- (1) https://docs.djangoproject.com/en/stable/topics/logging/#configuring-logging (2) https://docs.djangoproject.com/en/stable/topics/logging/#configuring-logging  File: python.info, Node: Using a rotator and namer to customize log rotation processing, Next: A more elaborate multiprocessing example, Prev: An example dictionary-based configuration, Up: Logging Cookbook 10.7.16 Using a rotator and namer to customize log rotation processing ---------------------------------------------------------------------- An example of how you can define a namer and rotator is given in the following snippet, which shows zlib-based compression of the log file: def namer(name): return name + ".gz" def rotator(source, dest): with open(source, "rb") as sf: data = sf.read() compressed = zlib.compress(data, 9) with open(dest, "wb") as df: df.write(compressed) os.remove(source) rh = logging.handlers.RotatingFileHandler(...) rh.rotator = rotator rh.namer = namer These are not “true” .gz files, as they are bare compressed data, with no “container” such as you’d find in an actual gzip file. This snippet is just for illustration purposes.  File: python.info, Node: A more elaborate multiprocessing example, Next: Inserting a BOM into messages sent to a SysLogHandler, Prev: Using a rotator and namer to customize log rotation processing, Up: Logging Cookbook 10.7.17 A more elaborate multiprocessing example ------------------------------------------------ The following working example shows how logging can be used with multiprocessing using configuration files. The configurations are fairly simple, but serve to illustrate how more complex ones could be implemented in a real multiprocessing scenario. In the example, the main process spawns a listener process and some worker processes. Each of the main process, the listener and the workers have three separate configurations (the workers all share the same configuration). We can see logging in the main process, how the workers log to a QueueHandler and how the listener implements a QueueListener and a more complex logging configuration, and arranges to dispatch events received via the queue to the handlers specified in the configuration. Note that these configurations are purely illustrative, but you should be able to adapt this example to your own scenario. Here’s the script - the docstrings and the comments hopefully explain how it works: import logging import logging.config import logging.handlers from multiprocessing import Process, Queue, Event, current_process import os import random import time class MyHandler: """ A simple handler for logging events. It runs in the listener process and dispatches events to loggers based on the name in the received record, which then get dispatched, by the logging system, to the handlers configured for those loggers. """ def handle(self, record): if record.name == "root": logger = logging.getLogger() else: logger = logging.getLogger(record.name) if logger.isEnabledFor(record.levelno): # The process name is transformed just to show that it's the listener # doing the logging to files and console record.processName = '%s (for %s)' % (current_process().name, record.processName) logger.handle(record) def listener_process(q, stop_event, config): """ This could be done in the main process, but is just done in a separate process for illustrative purposes. This initialises logging according to the specified configuration, starts the listener and waits for the main process to signal completion via the event. The listener is then stopped, and the process exits. """ logging.config.dictConfig(config) listener = logging.handlers.QueueListener(q, MyHandler()) listener.start() if os.name == 'posix': # On POSIX, the setup logger will have been configured in the # parent process, but should have been disabled following the # dictConfig call. # On Windows, since fork isn't used, the setup logger won't # exist in the child, so it would be created and the message # would appear - hence the "if posix" clause. logger = logging.getLogger('setup') logger.critical('Should not appear, because of disabled logger ...') stop_event.wait() listener.stop() def worker_process(config): """ A number of these are spawned for the purpose of illustration. In practice, they could be a heterogeneous bunch of processes rather than ones which are identical to each other. This initialises logging according to the specified configuration, and logs a hundred messages with random levels to randomly selected loggers. A small sleep is added to allow other processes a chance to run. This is not strictly needed, but it mixes the output from the different processes a bit more than if it's left out. """ logging.config.dictConfig(config) levels = [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL] loggers = ['foo', 'foo.bar', 'foo.bar.baz', 'spam', 'spam.ham', 'spam.ham.eggs'] if os.name == 'posix': # On POSIX, the setup logger will have been configured in the # parent process, but should have been disabled following the # dictConfig call. # On Windows, since fork isn't used, the setup logger won't # exist in the child, so it would be created and the message # would appear - hence the "if posix" clause. logger = logging.getLogger('setup') logger.critical('Should not appear, because of disabled logger ...') for i in range(100): lvl = random.choice(levels) logger = logging.getLogger(random.choice(loggers)) logger.log(lvl, 'Message no. %d', i) time.sleep(0.01) def main(): q = Queue() # The main process gets a simple configuration which prints to the console. config_initial = { 'version': 1, 'handlers': { 'console': { 'class': 'logging.StreamHandler', 'level': 'INFO' } }, 'root': { 'handlers': ['console'], 'level': 'DEBUG' } } # The worker process configuration is just a QueueHandler attached to the # root logger, which allows all messages to be sent to the queue. # We disable existing loggers to disable the "setup" logger used in the # parent process. This is needed on POSIX because the logger will # be there in the child following a fork(). config_worker = { 'version': 1, 'disable_existing_loggers': True, 'handlers': { 'queue': { 'class': 'logging.handlers.QueueHandler', 'queue': q } }, 'root': { 'handlers': ['queue'], 'level': 'DEBUG' } } # The listener process configuration shows that the full flexibility of # logging configuration is available to dispatch events to handlers however # you want. # We disable existing loggers to disable the "setup" logger used in the # parent process. This is needed on POSIX because the logger will # be there in the child following a fork(). config_listener = { 'version': 1, 'disable_existing_loggers': True, 'formatters': { 'detailed': { 'class': 'logging.Formatter', 'format': '%(asctime)s %(name)-15s %(levelname)-8s %(processName)-10s %(message)s' }, 'simple': { 'class': 'logging.Formatter', 'format': '%(name)-15s %(levelname)-8s %(processName)-10s %(message)s' } }, 'handlers': { 'console': { 'class': 'logging.StreamHandler', 'formatter': 'simple', 'level': 'INFO' }, 'file': { 'class': 'logging.FileHandler', 'filename': 'mplog.log', 'mode': 'w', 'formatter': 'detailed' }, 'foofile': { 'class': 'logging.FileHandler', 'filename': 'mplog-foo.log', 'mode': 'w', 'formatter': 'detailed' }, 'errors': { 'class': 'logging.FileHandler', 'filename': 'mplog-errors.log', 'mode': 'w', 'formatter': 'detailed', 'level': 'ERROR' } }, 'loggers': { 'foo': { 'handlers': ['foofile'] } }, 'root': { 'handlers': ['console', 'file', 'errors'], 'level': 'DEBUG' } } # Log some initial events, just to show that logging in the parent works # normally. logging.config.dictConfig(config_initial) logger = logging.getLogger('setup') logger.info('About to create workers ...') workers = [] for i in range(5): wp = Process(target=worker_process, name='worker %d' % (i + 1), args=(config_worker,)) workers.append(wp) wp.start() logger.info('Started worker: %s', wp.name) logger.info('About to create listener ...') stop_event = Event() lp = Process(target=listener_process, name='listener', args=(q, stop_event, config_listener)) lp.start() logger.info('Started listener') # We now hang around for the workers to finish their work. for wp in workers: wp.join() # Workers all done, listening can now stop. # Logging in the parent still works normally. logger.info('Telling listener to stop ...') stop_event.set() lp.join() logger.info('All done.') if __name__ == '__main__': main()  File: python.info, Node: Inserting a BOM into messages sent to a SysLogHandler, Next: Implementing structured logging, Prev: A more elaborate multiprocessing example, Up: Logging Cookbook 10.7.18 Inserting a BOM into messages sent to a SysLogHandler ------------------------------------------------------------- RFC 5424(1) requires that a Unicode message be sent to a syslog daemon as a set of bytes which have the following structure: an optional pure-ASCII component, followed by a UTF-8 Byte Order Mark (BOM), followed by Unicode encoded using UTF-8. (See the relevant section of the specification(2).) In Python 3.1, code was added to *note SysLogHandler: a1e. to insert a BOM into the message, but unfortunately, it was implemented incorrectly, with the BOM appearing at the beginning of the message and hence not allowing any pure-ASCII component to appear before it. As this behaviour is broken, the incorrect BOM insertion code is being removed from Python 3.2.4 and later. However, it is not being replaced, and if you want to produce RFC 5424(3)-compliant messages which include a BOM, an optional pure-ASCII sequence before it and arbitrary Unicode after it, encoded using UTF-8, then you need to do the following: 1. Attach a *note Formatter: 1d61. instance to your *note SysLogHandler: a1e. instance, with a format string such as: 'ASCII section\ufeffUnicode section' The Unicode code point U+FEFF, when encoded using UTF-8, will be encoded as a UTF-8 BOM – the byte-string ‘b'\xef\xbb\xbf'’. 2. Replace the ASCII section with whatever placeholders you like, but make sure that the data that appears in there after substitution is always ASCII (that way, it will remain unchanged after UTF-8 encoding). 3. Replace the Unicode section with whatever placeholders you like; if the data which appears there after substitution contains characters outside the ASCII range, that’s fine – it will be encoded using UTF-8. The formatted message `will' be encoded using UTF-8 encoding by ‘SysLogHandler’. If you follow the above rules, you should be able to produce RFC 5424(4)-compliant messages. If you don’t, logging may not complain, but your messages will not be RFC 5424-compliant, and your syslog daemon may complain. ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc5424.html (2) https://tools.ietf.org/html/rfc5424.html#section-6 (3) https://tools.ietf.org/html/rfc5424.html (4) https://tools.ietf.org/html/rfc5424.html  File: python.info, Node: Implementing structured logging, Next: Customizing handlers with dictConfig, Prev: Inserting a BOM into messages sent to a SysLogHandler, Up: Logging Cookbook 10.7.19 Implementing structured logging --------------------------------------- Although most logging messages are intended for reading by humans, and thus not readily machine-parseable, there might be circumstances where you want to output messages in a structured format which `is' capable of being parsed by a program (without needing complex regular expressions to parse the log message). This is straightforward to achieve using the logging package. There are a number of ways in which this could be achieved, but the following is a simple approach which uses JSON to serialise the event in a machine-parseable manner: import json import logging class StructuredMessage: def __init__(self, message, /, **kwargs): self.message = message self.kwargs = kwargs def __str__(self): return '%s >>> %s' % (self.message, json.dumps(self.kwargs)) _ = StructuredMessage # optional, to improve readability logging.basicConfig(level=logging.INFO, format='%(message)s') logging.info(_('message 1', foo='bar', bar='baz', num=123, fnum=123.456)) If the above script is run, it prints: message 1 >>> {"fnum": 123.456, "num": 123, "bar": "baz", "foo": "bar"} Note that the order of items might be different according to the version of Python used. If you need more specialised processing, you can use a custom JSON encoder, as in the following complete example: from __future__ import unicode_literals import json import logging # This next bit is to ensure the script runs unchanged on 2.x and 3.x try: unicode except NameError: unicode = str class Encoder(json.JSONEncoder): def default(self, o): if isinstance(o, set): return tuple(o) elif isinstance(o, unicode): return o.encode('unicode_escape').decode('ascii') return super(Encoder, self).default(o) class StructuredMessage: def __init__(self, message, /, **kwargs): self.message = message self.kwargs = kwargs def __str__(self): s = Encoder().encode(self.kwargs) return '%s >>> %s' % (self.message, s) _ = StructuredMessage # optional, to improve readability def main(): logging.basicConfig(level=logging.INFO, format='%(message)s') logging.info(_('message 1', set_value={1, 2, 3}, snowman='\u2603')) if __name__ == '__main__': main() When the above script is run, it prints: message 1 >>> {"snowman": "\u2603", "set_value": [1, 2, 3]} Note that the order of items might be different according to the version of Python used.  File: python.info, Node: Customizing handlers with dictConfig, Next: Using particular formatting styles throughout your application, Prev: Implementing structured logging, Up: Logging Cookbook 10.7.20 Customizing handlers with ‘dictConfig()’ ------------------------------------------------ There are times when you want to customize logging handlers in particular ways, and if you use *note dictConfig(): b2b. you may be able to do this without subclassing. As an example, consider that you may want to set the ownership of a log file. On POSIX, this is easily done using *note shutil.chown(): a76, but the file handlers in the stdlib don’t offer built-in support. You can customize handler creation using a plain function such as: def owned_file_handler(filename, mode='a', encoding=None, owner=None): if owner: if not os.path.exists(filename): open(filename, 'a').close() shutil.chown(filename, *owner) return logging.FileHandler(filename, mode, encoding) You can then specify, in a logging configuration passed to *note dictConfig(): b2b, that a logging handler be created by calling this function: LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'formatters': { 'default': { 'format': '%(asctime)s %(levelname)s %(name)s %(message)s' }, }, 'handlers': { 'file':{ # The values below are popped from this dictionary and # used to create the handler, set the handler's level and # its formatter. '()': owned_file_handler, 'level':'DEBUG', 'formatter': 'default', # The values below are passed to the handler creator callable # as keyword arguments. 'owner': ['pulse', 'pulse'], 'filename': 'chowntest.log', 'mode': 'w', 'encoding': 'utf-8', }, }, 'root': { 'handlers': ['file'], 'level': 'DEBUG', }, } In this example I am setting the ownership using the ‘pulse’ user and group, just for the purposes of illustration. Putting it together into a working script, ‘chowntest.py’: import logging, logging.config, os, shutil def owned_file_handler(filename, mode='a', encoding=None, owner=None): if owner: if not os.path.exists(filename): open(filename, 'a').close() shutil.chown(filename, *owner) return logging.FileHandler(filename, mode, encoding) LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'formatters': { 'default': { 'format': '%(asctime)s %(levelname)s %(name)s %(message)s' }, }, 'handlers': { 'file':{ # The values below are popped from this dictionary and # used to create the handler, set the handler's level and # its formatter. '()': owned_file_handler, 'level':'DEBUG', 'formatter': 'default', # The values below are passed to the handler creator callable # as keyword arguments. 'owner': ['pulse', 'pulse'], 'filename': 'chowntest.log', 'mode': 'w', 'encoding': 'utf-8', }, }, 'root': { 'handlers': ['file'], 'level': 'DEBUG', }, } logging.config.dictConfig(LOGGING) logger = logging.getLogger('mylogger') logger.debug('A debug message') To run this, you will probably need to run as ‘root’: $ sudo python3.3 chowntest.py $ cat chowntest.log 2013-11-05 09:34:51,128 DEBUG mylogger A debug message $ ls -l chowntest.log -rw-r--r-- 1 pulse pulse 55 2013-11-05 09:34 chowntest.log Note that this example uses Python 3.3 because that’s where *note shutil.chown(): a76. makes an appearance. This approach should work with any Python version that supports *note dictConfig(): b2b. - namely, Python 2.7, 3.2 or later. With pre-3.3 versions, you would need to implement the actual ownership change using e.g. *note os.chown(): a34. In practice, the handler-creating function may be in a utility module somewhere in your project. Instead of the line in the configuration: '()': owned_file_handler, you could use e.g.: '()': 'ext://project.util.owned_file_handler', where ‘project.util’ can be replaced with the actual name of the package where the function resides. In the above working script, using ‘'ext://__main__.owned_file_handler'’ should work. Here, the actual callable is resolved by *note dictConfig(): b2b. from the ‘ext://’ specification. This example hopefully also points the way to how you could implement other types of file change - e.g. setting specific POSIX permission bits - in the same way, using *note os.chmod(): a33. Of course, the approach could also be extended to types of handler other than a *note FileHandler: 1dc8. - for example, one of the rotating file handlers, or a different type of handler altogether.  File: python.info, Node: Using particular formatting styles throughout your application, Next: Configuring filters with dictConfig, Prev: Customizing handlers with dictConfig, Up: Logging Cookbook 10.7.21 Using particular formatting styles throughout your application ---------------------------------------------------------------------- In Python 3.2, the *note Formatter: 1d61. gained a ‘style’ keyword parameter which, while defaulting to ‘%’ for backward compatibility, allowed the specification of ‘{’ or ‘$’ to support the formatting approaches supported by *note str.format(): 4da. and *note string.Template: 3eb. Note that this governs the formatting of logging messages for final output to logs, and is completely orthogonal to how an individual logging message is constructed. Logging calls (*note debug(): 710, *note info(): 1d63. etc.) only take positional parameters for the actual logging message itself, with keyword parameters used only for determining options for how to handle the logging call (e.g. the ‘exc_info’ keyword parameter to indicate that traceback information should be logged, or the ‘extra’ keyword parameter to indicate additional contextual information to be added to the log). So you cannot directly make logging calls using *note str.format(): 4da. or *note string.Template: 3eb. syntax, because internally the logging package uses %-formatting to merge the format string and the variable arguments. There would no changing this while preserving backward compatibility, since all logging calls which are out there in existing code will be using %-format strings. There have been suggestions to associate format styles with specific loggers, but that approach also runs into backward compatibility problems because any existing code could be using a given logger name and using %-formatting. For logging to work interoperably between any third-party libraries and your code, decisions about formatting need to be made at the level of the individual logging call. This opens up a couple of ways in which alternative formatting styles can be accommodated. * Menu: * Using LogRecord factories:: * Using custom message objects::  File: python.info, Node: Using LogRecord factories, Next: Using custom message objects, Up: Using particular formatting styles throughout your application 10.7.21.1 Using LogRecord factories ................................... In Python 3.2, along with the *note Formatter: 1d61. changes mentioned above, the logging package gained the ability to allow users to set their own *note LogRecord: 906. subclasses, using the *note setLogRecordFactory(): 1d96. function. You can use this to set your own subclass of *note LogRecord: 906, which does the Right Thing by overriding the *note getMessage(): 1d94. method. The base class implementation of this method is where the ‘msg % args’ formatting happens, and where you can substitute your alternate formatting; however, you should be careful to support all formatting styles and allow %-formatting as the default, to ensure interoperability with other code. Care should also be taken to call ‘str(self.msg)’, just as the base implementation does. Refer to the reference documentation on *note setLogRecordFactory(): 1d96. and *note LogRecord: 906. for more information.  File: python.info, Node: Using custom message objects, Prev: Using LogRecord factories, Up: Using particular formatting styles throughout your application 10.7.21.2 Using custom message objects ...................................... There is another, perhaps simpler way that you can use {}- and $- formatting to construct your individual log messages. You may recall (from *note Using arbitrary objects as messages: 1d98.) that when logging you can use an arbitrary object as a message format string, and that the logging package will call *note str(): 330. on that object to get the actual format string. Consider the following two classes: class BraceMessage: def __init__(self, fmt, /, *args, **kwargs): self.fmt = fmt self.args = args self.kwargs = kwargs def __str__(self): return self.fmt.format(*self.args, **self.kwargs) class DollarMessage: def __init__(self, fmt, /, **kwargs): self.fmt = fmt self.kwargs = kwargs def __str__(self): from string import Template return Template(self.fmt).substitute(**self.kwargs) Either of these can be used in place of a format string, to allow {}- or $-formatting to be used to build the actual “message” part which appears in the formatted log output in place of “%(message)s” or “{message}” or “$message”. If you find it a little unwieldy to use the class names whenever you want to log something, you can make it more palatable if you use an alias such as ‘M’ or ‘_’ for the message (or perhaps ‘__’, if you are using ‘_’ for localization). Examples of this approach are given below. Firstly, formatting with *note str.format(): 4da.: >>> __ = BraceMessage >>> print(__('Message with {0} {1}', 2, 'placeholders')) Message with 2 placeholders >>> class Point: pass ... >>> p = Point() >>> p.x = 0.5 >>> p.y = 0.5 >>> print(__('Message with coordinates: ({point.x:.2f}, {point.y:.2f})', point=p)) Message with coordinates: (0.50, 0.50) Secondly, formatting with *note string.Template: 3eb.: >>> __ = DollarMessage >>> print(__('Message with $num $what', num=2, what='placeholders')) Message with 2 placeholders >>> One thing to note is that you pay no significant performance penalty with this approach: the actual formatting happens not when you make the logging call, but when (and if) the logged message is actually about to be output to a log by a handler. So the only slightly unusual thing which might trip you up is that the parentheses go around the format string and the arguments, not just the format string. That’s because the __ notation is just syntax sugar for a constructor call to one of the ‘XXXMessage’ classes shown above.  File: python.info, Node: Configuring filters with dictConfig, Next: Customized exception formatting, Prev: Using particular formatting styles throughout your application, Up: Logging Cookbook 10.7.22 Configuring filters with ‘dictConfig()’ ----------------------------------------------- You `can' configure filters using *note dictConfig(): b2b, though it might not be obvious at first glance how to do it (hence this recipe). Since *note Filter: b77. is the only filter class included in the standard library, and it is unlikely to cater to many requirements (it’s only there as a base class), you will typically need to define your own *note Filter: b77. subclass with an overridden *note filter(): 1d8e. method. To do this, specify the ‘()’ key in the configuration dictionary for the filter, specifying a callable which will be used to create the filter (a class is the most obvious, but you can provide any callable which returns a *note Filter: b77. instance). Here is a complete example: import logging import logging.config import sys class MyFilter(logging.Filter): def __init__(self, param=None): self.param = param def filter(self, record): if self.param is None: allow = True else: allow = self.param not in record.msg if allow: record.msg = 'changed: ' + record.msg return allow LOGGING = { 'version': 1, 'filters': { 'myfilter': { '()': MyFilter, 'param': 'noshow', } }, 'handlers': { 'console': { 'class': 'logging.StreamHandler', 'filters': ['myfilter'] } }, 'root': { 'level': 'DEBUG', 'handlers': ['console'] }, } if __name__ == '__main__': logging.config.dictConfig(LOGGING) logging.debug('hello') logging.debug('hello - noshow') This example shows how you can pass configuration data to the callable which constructs the instance, in the form of keyword parameters. When run, the above script will print: changed: hello which shows that the filter is working as configured. A couple of extra points to note: * If you can’t refer to the callable directly in the configuration (e.g. if it lives in a different module, and you can’t import it directly where the configuration dictionary is), you can use the form ‘ext://...’ as described in *note Access to external objects: 1dbf. For example, you could have used the text ‘'ext://__main__.MyFilter'’ instead of ‘MyFilter’ in the above example. * As well as for filters, this technique can also be used to configure custom handlers and formatters. See *note User-defined objects: 1db8. for more information on how logging supports using user-defined objects in its configuration, and see the other cookbook recipe *note Customizing handlers with dictConfig(): 3edf. above.  File: python.info, Node: Customized exception formatting, Next: Speaking logging messages, Prev: Configuring filters with dictConfig, Up: Logging Cookbook 10.7.23 Customized exception formatting --------------------------------------- There might be times when you want to do customized exception formatting - for argument’s sake, let’s say you want exactly one line per logged event, even when exception information is present. You can do this with a custom formatter class, as shown in the following example: import logging class OneLineExceptionFormatter(logging.Formatter): def formatException(self, exc_info): """ Format an exception so that it prints on a single line. """ result = super(OneLineExceptionFormatter, self).formatException(exc_info) return repr(result) # or format into one line however you want to def format(self, record): s = super(OneLineExceptionFormatter, self).format(record) if record.exc_text: s = s.replace('\n', '') + '|' return s def configure_logging(): fh = logging.FileHandler('output.txt', 'w') f = OneLineExceptionFormatter('%(asctime)s|%(levelname)s|%(message)s|', '%d/%m/%Y %H:%M:%S') fh.setFormatter(f) root = logging.getLogger() root.setLevel(logging.DEBUG) root.addHandler(fh) def main(): configure_logging() logging.info('Sample message') try: x = 1 / 0 except ZeroDivisionError as e: logging.exception('ZeroDivisionError: %s', e) if __name__ == '__main__': main() When run, this produces a file with exactly two lines: 28/01/2015 07:21:23|INFO|Sample message| 28/01/2015 07:21:23|ERROR|ZeroDivisionError: integer division or modulo by zero|'Traceback (most recent call last):\n File "logtest7.py", line 30, in main\n x = 1 / 0\nZeroDivisionError: integer division or modulo by zero'| While the above treatment is simplistic, it points the way to how exception information can be formatted to your liking. The *note traceback: 113. module may be helpful for more specialized needs.  File: python.info, Node: Speaking logging messages, Next: Buffering logging messages and outputting them conditionally, Prev: Customized exception formatting, Up: Logging Cookbook 10.7.24 Speaking logging messages --------------------------------- There might be situations when it is desirable to have logging messages rendered in an audible rather than a visible format. This is easy to do if you have text-to-speech (TTS) functionality available in your system, even if it doesn’t have a Python binding. Most TTS systems have a command line program you can run, and this can be invoked from a handler using *note subprocess: f9. It’s assumed here that TTS command line programs won’t expect to interact with users or take a long time to complete, and that the frequency of logged messages will be not so high as to swamp the user with messages, and that it’s acceptable to have the messages spoken one at a time rather than concurrently, The example implementation below waits for one message to be spoken before the next is processed, and this might cause other handlers to be kept waiting. Here is a short example showing the approach, which assumes that the ‘espeak’ TTS package is available: import logging import subprocess import sys class TTSHandler(logging.Handler): def emit(self, record): msg = self.format(record) # Speak slowly in a female English voice cmd = ['espeak', '-s150', '-ven+f3', msg] p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) # wait for the program to finish p.communicate() def configure_logging(): h = TTSHandler() root = logging.getLogger() root.addHandler(h) # the default formatter just returns the message root.setLevel(logging.DEBUG) def main(): logging.info('Hello') logging.debug('Goodbye') if __name__ == '__main__': configure_logging() sys.exit(main()) When run, this script should say “Hello” and then “Goodbye” in a female voice. The above approach can, of course, be adapted to other TTS systems and even other systems altogether which can process messages via external programs run from a command line.  File: python.info, Node: Buffering logging messages and outputting them conditionally, Next: Formatting times using UTC GMT via configuration, Prev: Speaking logging messages, Up: Logging Cookbook 10.7.25 Buffering logging messages and outputting them conditionally -------------------------------------------------------------------- There might be situations where you want to log messages in a temporary area and only output them if a certain condition occurs. For example, you may want to start logging debug events in a function, and if the function completes without errors, you don’t want to clutter the log with the collected debug information, but if there is an error, you want all the debug information to be output as well as the error. Here is an example which shows how you could do this using a decorator for your functions where you want logging to behave this way. It makes use of the *note logging.handlers.MemoryHandler: 1dc2, which allows buffering of logged events until some condition occurs, at which point the buffered events are ‘flushed’ - passed to another handler (the ‘target’ handler) for processing. By default, the ‘MemoryHandler’ flushed when its buffer gets filled up or an event whose level is greater than or equal to a specified threshold is seen. You can use this recipe with a more specialised subclass of ‘MemoryHandler’ if you want custom flushing behavior. The example script has a simple function, ‘foo’, which just cycles through all the logging levels, writing to ‘sys.stderr’ to say what level it’s about to log at, and then actually logging a message at that level. You can pass a parameter to ‘foo’ which, if true, will log at ERROR and CRITICAL levels - otherwise, it only logs at DEBUG, INFO and WARNING levels. The script just arranges to decorate ‘foo’ with a decorator which will do the conditional logging that’s required. The decorator takes a logger as a parameter and attaches a memory handler for the duration of the call to the decorated function. The decorator can be additionally parameterised using a target handler, a level at which flushing should occur, and a capacity for the buffer (number of records buffered). These default to a *note StreamHandler: b75. which writes to ‘sys.stderr’, ‘logging.ERROR’ and ‘100’ respectively. Here’s the script: import logging from logging.handlers import MemoryHandler import sys logger = logging.getLogger(__name__) logger.addHandler(logging.NullHandler()) def log_if_errors(logger, target_handler=None, flush_level=None, capacity=None): if target_handler is None: target_handler = logging.StreamHandler() if flush_level is None: flush_level = logging.ERROR if capacity is None: capacity = 100 handler = MemoryHandler(capacity, flushLevel=flush_level, target=target_handler) def decorator(fn): def wrapper(*args, **kwargs): logger.addHandler(handler) try: return fn(*args, **kwargs) except Exception: logger.exception('call failed') raise finally: super(MemoryHandler, handler).flush() logger.removeHandler(handler) return wrapper return decorator def write_line(s): sys.stderr.write('%s\n' % s) def foo(fail=False): write_line('about to log at DEBUG ...') logger.debug('Actually logged at DEBUG') write_line('about to log at INFO ...') logger.info('Actually logged at INFO') write_line('about to log at WARNING ...') logger.warning('Actually logged at WARNING') if fail: write_line('about to log at ERROR ...') logger.error('Actually logged at ERROR') write_line('about to log at CRITICAL ...') logger.critical('Actually logged at CRITICAL') return fail decorated_foo = log_if_errors(logger)(foo) if __name__ == '__main__': logger.setLevel(logging.DEBUG) write_line('Calling undecorated foo with False') assert not foo(False) write_line('Calling undecorated foo with True') assert foo(True) write_line('Calling decorated foo with False') assert not decorated_foo(False) write_line('Calling decorated foo with True') assert decorated_foo(True) When this script is run, the following output should be observed: Calling undecorated foo with False about to log at DEBUG ... about to log at INFO ... about to log at WARNING ... Calling undecorated foo with True about to log at DEBUG ... about to log at INFO ... about to log at WARNING ... about to log at ERROR ... about to log at CRITICAL ... Calling decorated foo with False about to log at DEBUG ... about to log at INFO ... about to log at WARNING ... Calling decorated foo with True about to log at DEBUG ... about to log at INFO ... about to log at WARNING ... about to log at ERROR ... Actually logged at DEBUG Actually logged at INFO Actually logged at WARNING Actually logged at ERROR about to log at CRITICAL ... Actually logged at CRITICAL As you can see, actual logging output only occurs when an event is logged whose severity is ERROR or greater, but in that case, any previous events at lower severities are also logged. You can of course use the conventional means of decoration: @log_if_errors(logger) def foo(fail=False): ...  File: python.info, Node: Formatting times using UTC GMT via configuration, Next: Using a context manager for selective logging, Prev: Buffering logging messages and outputting them conditionally, Up: Logging Cookbook 10.7.26 Formatting times using UTC (GMT) via configuration ---------------------------------------------------------- Sometimes you want to format times using UTC, which can be done using a class such as ‘UTCFormatter’, shown below: import logging import time class UTCFormatter(logging.Formatter): converter = time.gmtime and you can then use the ‘UTCFormatter’ in your code instead of *note Formatter: 1d61. If you want to do that via configuration, you can use the *note dictConfig(): b2b. API with an approach illustrated by the following complete example: import logging import logging.config import time class UTCFormatter(logging.Formatter): converter = time.gmtime LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'formatters': { 'utc': { '()': UTCFormatter, 'format': '%(asctime)s %(message)s', }, 'local': { 'format': '%(asctime)s %(message)s', } }, 'handlers': { 'console1': { 'class': 'logging.StreamHandler', 'formatter': 'utc', }, 'console2': { 'class': 'logging.StreamHandler', 'formatter': 'local', }, }, 'root': { 'handlers': ['console1', 'console2'], } } if __name__ == '__main__': logging.config.dictConfig(LOGGING) logging.warning('The local time is %s', time.asctime()) When this script is run, it should print something like: 2015-10-17 12:53:29,501 The local time is Sat Oct 17 13:53:29 2015 2015-10-17 13:53:29,501 The local time is Sat Oct 17 13:53:29 2015 showing how the time is formatted both as local time and UTC, one for each handler.  File: python.info, Node: Using a context manager for selective logging, Next: A CLI application starter template, Prev: Formatting times using UTC GMT via configuration, Up: Logging Cookbook 10.7.27 Using a context manager for selective logging ----------------------------------------------------- There are times when it would be useful to temporarily change the logging configuration and revert it back after doing something. For this, a context manager is the most obvious way of saving and restoring the logging context. Here is a simple example of such a context manager, which allows you to optionally change the logging level and add a logging handler purely in the scope of the context manager: import logging import sys class LoggingContext: def __init__(self, logger, level=None, handler=None, close=True): self.logger = logger self.level = level self.handler = handler self.close = close def __enter__(self): if self.level is not None: self.old_level = self.logger.level self.logger.setLevel(self.level) if self.handler: self.logger.addHandler(self.handler) def __exit__(self, et, ev, tb): if self.level is not None: self.logger.setLevel(self.old_level) if self.handler: self.logger.removeHandler(self.handler) if self.handler and self.close: self.handler.close() # implicit return of None => don't swallow exceptions If you specify a level value, the logger’s level is set to that value in the scope of the with block covered by the context manager. If you specify a handler, it is added to the logger on entry to the block and removed on exit from the block. You can also ask the manager to close the handler for you on block exit - you could do this if you don’t need the handler any more. To illustrate how it works, we can add the following block of code to the above: if __name__ == '__main__': logger = logging.getLogger('foo') logger.addHandler(logging.StreamHandler()) logger.setLevel(logging.INFO) logger.info('1. This should appear just once on stderr.') logger.debug('2. This should not appear.') with LoggingContext(logger, level=logging.DEBUG): logger.debug('3. This should appear once on stderr.') logger.debug('4. This should not appear.') h = logging.StreamHandler(sys.stdout) with LoggingContext(logger, level=logging.DEBUG, handler=h, close=True): logger.debug('5. This should appear twice - once on stderr and once on stdout.') logger.info('6. This should appear just once on stderr.') logger.debug('7. This should not appear.') We initially set the logger’s level to ‘INFO’, so message #1 appears and message #2 doesn’t. We then change the level to ‘DEBUG’ temporarily in the following ‘with’ block, and so message #3 appears. After the block exits, the logger’s level is restored to ‘INFO’ and so message #4 doesn’t appear. In the next ‘with’ block, we set the level to ‘DEBUG’ again but also add a handler writing to ‘sys.stdout’. Thus, message #5 appears twice on the console (once via ‘stderr’ and once via ‘stdout’). After the ‘with’ statement’s completion, the status is as it was before so message #6 appears (like message #1) whereas message #7 doesn’t (just like message #2). If we run the resulting script, the result is as follows: $ python logctx.py 1. This should appear just once on stderr. 3. This should appear once on stderr. 5. This should appear twice - once on stderr and once on stdout. 5. This should appear twice - once on stderr and once on stdout. 6. This should appear just once on stderr. If we run it again, but pipe ‘stderr’ to ‘/dev/null’, we see the following, which is the only message written to ‘stdout’: $ python logctx.py 2>/dev/null 5. This should appear twice - once on stderr and once on stdout. Once again, but piping ‘stdout’ to ‘/dev/null’, we get: $ python logctx.py >/dev/null 1. This should appear just once on stderr. 3. This should appear once on stderr. 5. This should appear twice - once on stderr and once on stdout. 6. This should appear just once on stderr. In this case, the message #5 printed to ‘stdout’ doesn’t appear, as expected. Of course, the approach described here can be generalised, for example to attach logging filters temporarily. Note that the above code works in Python 2 as well as Python 3.  File: python.info, Node: A CLI application starter template, Next: A Qt GUI for logging, Prev: Using a context manager for selective logging, Up: Logging Cookbook 10.7.28 A CLI application starter template ------------------------------------------ Here’s an example which shows how you can: * Use a logging level based on command-line arguments * Dispatch to multiple subcommands in separate files, all logging at the same level in a consistent way * Make use of simple, minimal configuration Suppose we have a command-line application whose job is to stop, start or restart some services. This could be organised for the purposes of illustration as a file ‘app.py’ that is the main script for the application, with individual commands implemented in ‘start.py’, ‘stop.py’ and ‘restart.py’. Suppose further that we want to control the verbosity of the application via a command-line argument, defaulting to ‘logging.INFO’. Here’s one way that ‘app.py’ could be written: import argparse import importlib import logging import os import sys def main(args=None): scriptname = os.path.basename(__file__) parser = argparse.ArgumentParser(scriptname) levels = ('DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL') parser.add_argument('--log-level', default='INFO', choices=levels) subparsers = parser.add_subparsers(dest='command', help='Available commands:') start_cmd = subparsers.add_parser('start', help='Start a service') start_cmd.add_argument('name', metavar='NAME', help='Name of service to start') stop_cmd = subparsers.add_parser('stop', help='Stop one or more services') stop_cmd.add_argument('names', metavar='NAME', nargs='+', help='Name of service to stop') restart_cmd = subparsers.add_parser('restart', help='Restart one or more services') restart_cmd.add_argument('names', metavar='NAME', nargs='+', help='Name of service to restart') options = parser.parse_args() # the code to dispatch commands could all be in this file. For the purposes # of illustration only, we implement each command in a separate module. try: mod = importlib.import_module(options.command) cmd = getattr(mod, 'command') except (ImportError, AttributeError): print('Unable to find the code for command \'%s\'' % options.command) return 1 # Could get fancy here and load configuration from file or dictionary logging.basicConfig(level=options.log_level, format='%(levelname)s %(name)s %(message)s') cmd(options) if __name__ == '__main__': sys.exit(main()) And the ‘start’, ‘stop’ and ‘restart’ commands can be implemented in separate modules, like so for starting: # start.py import logging logger = logging.getLogger(__name__) def command(options): logger.debug('About to start %s', options.name) # actually do the command processing here ... logger.info('Started the \'%s\' service.', options.name) and thus for stopping: # stop.py import logging logger = logging.getLogger(__name__) def command(options): n = len(options.names) if n == 1: plural = '' services = '\'%s\'' % options.names[0] else: plural = 's' services = ', '.join('\'%s\'' % name for name in options.names) i = services.rfind(', ') services = services[:i] + ' and ' + services[i + 2:] logger.debug('About to stop %s', services) # actually do the command processing here ... logger.info('Stopped the %s service%s.', services, plural) and similarly for restarting: # restart.py import logging logger = logging.getLogger(__name__) def command(options): n = len(options.names) if n == 1: plural = '' services = '\'%s\'' % options.names[0] else: plural = 's' services = ', '.join('\'%s\'' % name for name in options.names) i = services.rfind(', ') services = services[:i] + ' and ' + services[i + 2:] logger.debug('About to restart %s', services) # actually do the command processing here ... logger.info('Restarted the %s service%s.', services, plural) If we run this application with the default log level, we get output like this: $ python app.py start foo INFO start Started the 'foo' service. $ python app.py stop foo bar INFO stop Stopped the 'foo' and 'bar' services. $ python app.py restart foo bar baz INFO restart Restarted the 'foo', 'bar' and 'baz' services. The first word is the logging level, and the second word is the module or package name of the place where the event was logged. If we change the logging level, then we can change the information sent to the log. For example, if we want more information: $ python app.py --log-level DEBUG start foo DEBUG start About to start foo INFO start Started the 'foo' service. $ python app.py --log-level DEBUG stop foo bar DEBUG stop About to stop 'foo' and 'bar' INFO stop Stopped the 'foo' and 'bar' services. $ python app.py --log-level DEBUG restart foo bar baz DEBUG restart About to restart 'foo', 'bar' and 'baz' INFO restart Restarted the 'foo', 'bar' and 'baz' services. And if we want less: $ python app.py --log-level WARNING start foo $ python app.py --log-level WARNING stop foo bar $ python app.py --log-level WARNING restart foo bar baz In this case, the commands don’t print anything to the console, since nothing at ‘WARNING’ level or above is logged by them.  File: python.info, Node: A Qt GUI for logging, Prev: A CLI application starter template, Up: Logging Cookbook 10.7.29 A Qt GUI for logging ---------------------------- A question that comes up from time to time is about how to log to a GUI application. The Qt(1) framework is a popular cross-platform UI framework with Python bindings using PySide2(2) or PyQt5(3) libraries. The following example shows how to log to a Qt GUI. This introduces a simple ‘QtHandler’ class which takes a callable, which should be a slot in the main thread that does GUI updates. A worker thread is also created to show how you can log to the GUI from both the UI itself (via a button for manual logging) as well as a worker thread doing work in the background (here, just logging messages at random levels with random short delays in between). The worker thread is implemented using Qt’s ‘QThread’ class rather than the *note threading: 109. module, as there are circumstances where one has to use ‘QThread’, which offers better integration with other ‘Qt’ components. The code should work with recent releases of either ‘PySide2’ or ‘PyQt5’. You should be able to adapt the approach to earlier versions of Qt. Please refer to the comments in the code snippet for more detailed information. import datetime import logging import random import sys import time # Deal with minor differences between PySide2 and PyQt5 try: from PySide2 import QtCore, QtGui, QtWidgets Signal = QtCore.Signal Slot = QtCore.Slot except ImportError: from PyQt5 import QtCore, QtGui, QtWidgets Signal = QtCore.pyqtSignal Slot = QtCore.pyqtSlot logger = logging.getLogger(__name__) # # Signals need to be contained in a QObject or subclass in order to be correctly # initialized. # class Signaller(QtCore.QObject): signal = Signal(str, logging.LogRecord) # # Output to a Qt GUI is only supposed to happen on the main thread. So, this # handler is designed to take a slot function which is set up to run in the main # thread. In this example, the function takes a string argument which is a # formatted log message, and the log record which generated it. The formatted # string is just a convenience - you could format a string for output any way # you like in the slot function itself. # # You specify the slot function to do whatever GUI updates you want. The handler # doesn't know or care about specific UI elements. # class QtHandler(logging.Handler): def __init__(self, slotfunc, *args, **kwargs): super(QtHandler, self).__init__(*args, **kwargs) self.signaller = Signaller() self.signaller.signal.connect(slotfunc) def emit(self, record): s = self.format(record) self.signaller.signal.emit(s, record) # # This example uses QThreads, which means that the threads at the Python level # are named something like "Dummy-1". The function below gets the Qt name of the # current thread. # def ctname(): return QtCore.QThread.currentThread().objectName() # # Used to generate random levels for logging. # LEVELS = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL) # # This worker class represents work that is done in a thread separate to the # main thread. The way the thread is kicked off to do work is via a button press # that connects to a slot in the worker. # # Because the default threadName value in the LogRecord isn't much use, we add # a qThreadName which contains the QThread name as computed above, and pass that # value in an "extra" dictionary which is used to update the LogRecord with the # QThread name. # # This example worker just outputs messages sequentially, interspersed with # random delays of the order of a few seconds. # class Worker(QtCore.QObject): @Slot() def start(self): extra = {'qThreadName': ctname() } logger.debug('Started work', extra=extra) i = 1 # Let the thread run until interrupted. This allows reasonably clean # thread termination. while not QtCore.QThread.currentThread().isInterruptionRequested(): delay = 0.5 + random.random() * 2 time.sleep(delay) level = random.choice(LEVELS) logger.log(level, 'Message after delay of %3.1f: %d', delay, i, extra=extra) i += 1 # # Implement a simple UI for this cookbook example. This contains: # # * A read-only text edit window which holds formatted log messages # * A button to start work and log stuff in a separate thread # * A button to log something from the main thread # * A button to clear the log window # class Window(QtWidgets.QWidget): COLORS = { logging.DEBUG: 'black', logging.INFO: 'blue', logging.WARNING: 'orange', logging.ERROR: 'red', logging.CRITICAL: 'purple', } def __init__(self, app): super(Window, self).__init__() self.app = app self.textedit = te = QtWidgets.QPlainTextEdit(self) # Set whatever the default monospace font is for the platform f = QtGui.QFont('nosuchfont') f.setStyleHint(f.Monospace) te.setFont(f) te.setReadOnly(True) PB = QtWidgets.QPushButton self.work_button = PB('Start background work', self) self.log_button = PB('Log a message at a random level', self) self.clear_button = PB('Clear log window', self) self.handler = h = QtHandler(self.update_status) # Remember to use qThreadName rather than threadName in the format string. fs = '%(asctime)s %(qThreadName)-12s %(levelname)-8s %(message)s' formatter = logging.Formatter(fs) h.setFormatter(formatter) logger.addHandler(h) # Set up to terminate the QThread when we exit app.aboutToQuit.connect(self.force_quit) # Lay out all the widgets layout = QtWidgets.QVBoxLayout(self) layout.addWidget(te) layout.addWidget(self.work_button) layout.addWidget(self.log_button) layout.addWidget(self.clear_button) self.setFixedSize(900, 400) # Connect the non-worker slots and signals self.log_button.clicked.connect(self.manual_update) self.clear_button.clicked.connect(self.clear_display) # Start a new worker thread and connect the slots for the worker self.start_thread() self.work_button.clicked.connect(self.worker.start) # Once started, the button should be disabled self.work_button.clicked.connect(lambda : self.work_button.setEnabled(False)) def start_thread(self): self.worker = Worker() self.worker_thread = QtCore.QThread() self.worker.setObjectName('Worker') self.worker_thread.setObjectName('WorkerThread') # for qThreadName self.worker.moveToThread(self.worker_thread) # This will start an event loop in the worker thread self.worker_thread.start() def kill_thread(self): # Just tell the worker to stop, then tell it to quit and wait for that # to happen self.worker_thread.requestInterruption() if self.worker_thread.isRunning(): self.worker_thread.quit() self.worker_thread.wait() else: print('worker has already exited.') def force_quit(self): # For use when the window is closed if self.worker_thread.isRunning(): self.kill_thread() # The functions below update the UI and run in the main thread because # that's where the slots are set up @Slot(str, logging.LogRecord) def update_status(self, status, record): color = self.COLORS.get(record.levelno, 'black') s = '<pre><font color="%s">%s</font></pre>' % (color, status) self.textedit.appendHtml(s) @Slot() def manual_update(self): # This function uses the formatted message passed in, but also uses # information from the record to format the message in an appropriate # color according to its severity (level). level = random.choice(LEVELS) extra = {'qThreadName': ctname() } logger.log(level, 'Manually logged!', extra=extra) @Slot() def clear_display(self): self.textedit.clear() def main(): QtCore.QThread.currentThread().setObjectName('MainThread') logging.getLogger().setLevel(logging.DEBUG) app = QtWidgets.QApplication(sys.argv) example = Window(app) example.show() sys.exit(app.exec_()) if __name__=='__main__': main() ---------- Footnotes ---------- (1) https://www.qt.io/ (2) https://pypi.org/project/PySide2/ (3) https://pypi.org/project/PyQt5/  File: python.info, Node: Regular Expression HOWTO, Next: Socket Programming HOWTO, Prev: Logging Cookbook, Up: Python HOWTOs 10.8 Regular Expression HOWTO ============================= Author: A.M. Kuchling <<amk@amk.ca>> Abstract ........ This document is an introductory tutorial to using regular expressions in Python with the *note re: dd. module. It provides a gentler introduction than the corresponding section in the Library Reference. * Menu: * Introduction: Introduction<15>. * Simple Patterns:: * Using Regular Expressions:: * More Pattern Power:: * Modifying Strings:: * Common Problems:: * Feedback::  File: python.info, Node: Introduction<15>, Next: Simple Patterns, Up: Regular Expression HOWTO 10.8.1 Introduction ------------------- Regular expressions (called REs, or regexes, or regex patterns) are essentially a tiny, highly specialized programming language embedded inside Python and made available through the *note re: dd. module. Using this little language, you specify the rules for the set of possible strings that you want to match; this set might contain English sentences, or e-mail addresses, or TeX commands, or anything you like. You can then ask questions such as “Does this string match the pattern?”, or “Is there a match for the pattern anywhere in this string?”. You can also use REs to modify a string or to split it apart in various ways. Regular expression patterns are compiled into a series of bytecodes which are then executed by a matching engine written in C. For advanced use, it may be necessary to pay careful attention to how the engine will execute a given RE, and write the RE in a certain way in order to produce bytecode that runs faster. Optimization isn’t covered in this document, because it requires that you have a good understanding of the matching engine’s internals. The regular expression language is relatively small and restricted, so not all possible string processing tasks can be done using regular expressions. There are also tasks that `can' be done with regular expressions, but the expressions turn out to be very complicated. In these cases, you may be better off writing Python code to do the processing; while Python code will be slower than an elaborate regular expression, it will also probably be more understandable.  File: python.info, Node: Simple Patterns, Next: Using Regular Expressions, Prev: Introduction<15>, Up: Regular Expression HOWTO 10.8.2 Simple Patterns ---------------------- We’ll start by learning about the simplest possible regular expressions. Since regular expressions are used to operate on strings, we’ll begin with the most common task: matching characters. For a detailed explanation of the computer science underlying regular expressions (deterministic and non-deterministic finite automata), you can refer to almost any textbook on writing compilers. * Menu: * Matching Characters:: * Repeating Things::  File: python.info, Node: Matching Characters, Next: Repeating Things, Up: Simple Patterns 10.8.2.1 Matching Characters ............................ Most letters and characters will simply match themselves. For example, the regular expression ‘test’ will match the string ‘test’ exactly. (You can enable a case-insensitive mode that would let this RE match ‘Test’ or ‘TEST’ as well; more about this later.) There are exceptions to this rule; some characters are special `metacharacters', and don’t match themselves. Instead, they signal that some out-of-the-ordinary thing should be matched, or they affect other portions of the RE by repeating them or changing their meaning. Much of this document is devoted to discussing various metacharacters and what they do. Here’s a complete list of the metacharacters; their meanings will be discussed in the rest of this HOWTO. . ^ $ * + ? { } [ ] \ | ( ) The first metacharacters we’ll look at are ‘[’ and ‘]’. They’re used for specifying a character class, which is a set of characters that you wish to match. Characters can be listed individually, or a range of characters can be indicated by giving two characters and separating them by a ‘'-'’. For example, ‘[abc]’ will match any of the characters ‘a’, ‘b’, or ‘c’; this is the same as ‘[a-c]’, which uses a range to express the same set of characters. If you wanted to match only lowercase letters, your RE would be ‘[a-z]’. Metacharacters are not active inside classes. For example, ‘[akm$]’ will match any of the characters ‘'a'’, ‘'k'’, ‘'m'’, or ‘'$'’; ‘'$'’ is usually a metacharacter, but inside a character class it’s stripped of its special nature. You can match the characters not listed within the class by `complementing' the set. This is indicated by including a ‘'^'’ as the first character of the class. For example, ‘[^5]’ will match any character except ‘'5'’. If the caret appears elsewhere in a character class, it does not have special meaning. For example: ‘[5^]’ will match either a ‘'5'’ or a ‘'^'’. Perhaps the most important metacharacter is the backslash, ‘\’. As in Python string literals, the backslash can be followed by various characters to signal various special sequences. It’s also used to escape all the metacharacters so you can still match them in patterns; for example, if you need to match a ‘[’ or ‘\’, you can precede them with a backslash to remove their special meaning: ‘\[’ or ‘\\’. Some of the special sequences beginning with ‘'\'’ represent predefined sets of characters that are often useful, such as the set of digits, the set of letters, or the set of anything that isn’t whitespace. Let’s take an example: ‘\w’ matches any alphanumeric character. If the regex pattern is expressed in bytes, this is equivalent to the class ‘[a-zA-Z0-9_]’. If the regex pattern is a string, ‘\w’ will match all the characters marked as letters in the Unicode database provided by the *note unicodedata: 11a. module. You can use the more restricted definition of ‘\w’ in a string pattern by supplying the *note re.ASCII: 3c8. flag when compiling the regular expression. The following list of special sequences isn’t complete. For a complete list of sequences and expanded class definitions for Unicode string patterns, see the last part of *note Regular Expression Syntax: 13f5. in the Standard Library reference. In general, the Unicode versions match any character that’s in the appropriate category in the Unicode database. ‘\d’ Matches any decimal digit; this is equivalent to the class ‘[0-9]’. ‘\D’ Matches any non-digit character; this is equivalent to the class ‘[^0-9]’. ‘\s’ Matches any whitespace character; this is equivalent to the class ‘[ \t\n\r\f\v]’. ‘\S’ Matches any non-whitespace character; this is equivalent to the class ‘[^ \t\n\r\f\v]’. ‘\w’ Matches any alphanumeric character; this is equivalent to the class ‘[a-zA-Z0-9_]’. ‘\W’ Matches any non-alphanumeric character; this is equivalent to the class ‘[^a-zA-Z0-9_]’. These sequences can be included inside a character class. For example, ‘[\s,.]’ is a character class that will match any whitespace character, or ‘','’ or ‘'.'’. The final metacharacter in this section is ‘.’. It matches anything except a newline character, and there’s an alternate mode (*note re.DOTALL: 13f9.) where it will match even a newline. ‘.’ is often used where you want to match “any character”.  File: python.info, Node: Repeating Things, Prev: Matching Characters, Up: Simple Patterns 10.8.2.2 Repeating Things ......................... Being able to match varying sets of characters is the first thing regular expressions can do that isn’t already possible with the methods available on strings. However, if that was the only additional capability of regexes, they wouldn’t be much of an advance. Another capability is that you can specify that portions of the RE must be repeated a certain number of times. The first metacharacter for repeating things that we’ll look at is ‘*’. ‘*’ doesn’t match the literal character ‘'*'’; instead, it specifies that the previous character can be matched zero or more times, instead of exactly once. For example, ‘ca*t’ will match ‘'ct'’ (0 ‘'a'’ characters), ‘'cat'’ (1 ‘'a'’), ‘'caaat'’ (3 ‘'a'’ characters), and so forth. Repetitions such as ‘*’ are `greedy'; when repeating a RE, the matching engine will try to repeat it as many times as possible. If later portions of the pattern don’t match, the matching engine will then back up and try again with fewer repetitions. A step-by-step example will make this more obvious. Let’s consider the expression ‘a[bcd]*b’. This matches the letter ‘'a'’, zero or more letters from the class ‘[bcd]’, and finally ends with a ‘'b'’. Now imagine matching this RE against the string ‘'abcbd'’. Step Matched Explanation ----------------------------------------------------------------- 1 ‘a’ The ‘a’ in the RE matches. 2 ‘abcbd’ The engine matches ‘[bcd]*’, going as far as it can, which is to the end of the string. 3 `Failure' The engine tries to match ‘b’, but the current position is at the end of the string, so it fails. 4 ‘abcb’ Back up, so that ‘[bcd]*’ matches one less character. 5 `Failure' Try ‘b’ again, but the current position is at the last character, which is a ‘'d'’. 6 ‘abc’ Back up again, so that ‘[bcd]*’ is only matching ‘bc’. 6 ‘abcb’ Try ‘b’ again. This time the character at the current position is ‘'b'’, so it succeeds. The end of the RE has now been reached, and it has matched ‘'abcb'’. This demonstrates how the matching engine goes as far as it can at first, and if no match is found it will then progressively back up and retry the rest of the RE again and again. It will back up until it has tried zero matches for ‘[bcd]*’, and if that subsequently fails, the engine will conclude that the string doesn’t match the RE at all. Another repeating metacharacter is ‘+’, which matches one or more times. Pay careful attention to the difference between ‘*’ and ‘+’; ‘*’ matches `zero' or more times, so whatever’s being repeated may not be present at all, while ‘+’ requires at least `one' occurrence. To use a similar example, ‘ca+t’ will match ‘'cat'’ (1 ‘'a'’), ‘'caaat'’ (3 ‘'a'’s), but won’t match ‘'ct'’. There are two more repeating qualifiers. The question mark character, ‘?’, matches either once or zero times; you can think of it as marking something as being optional. For example, ‘home-?brew’ matches either ‘'homebrew'’ or ‘'home-brew'’. The most complicated repeated qualifier is ‘{m,n}’, where `m' and `n' are decimal integers. This qualifier means there must be at least `m' repetitions, and at most `n'. For example, ‘a/{1,3}b’ will match ‘'a/b'’, ‘'a//b'’, and ‘'a///b'’. It won’t match ‘'ab'’, which has no slashes, or ‘'a////b'’, which has four. You can omit either `m' or `n'; in that case, a reasonable value is assumed for the missing value. Omitting `m' is interpreted as a lower limit of 0, while omitting `n' results in an upper bound of infinity. Readers of a reductionist bent may notice that the three other qualifiers can all be expressed using this notation. ‘{0,}’ is the same as ‘*’, ‘{1,}’ is equivalent to ‘+’, and ‘{0,1}’ is the same as ‘?’. It’s better to use ‘*’, ‘+’, or ‘?’ when you can, simply because they’re shorter and easier to read.  File: python.info, Node: Using Regular Expressions, Next: More Pattern Power, Prev: Simple Patterns, Up: Regular Expression HOWTO 10.8.3 Using Regular Expressions -------------------------------- Now that we’ve looked at some simple regular expressions, how do we actually use them in Python? The *note re: dd. module provides an interface to the regular expression engine, allowing you to compile REs into objects and then perform matches with them. * Menu: * Compiling Regular Expressions:: * The Backslash Plague:: * Performing Matches:: * Module-Level Functions: Module-Level Functions<2>. * Compilation Flags::  File: python.info, Node: Compiling Regular Expressions, Next: The Backslash Plague, Up: Using Regular Expressions 10.8.3.1 Compiling Regular Expressions ...................................... Regular expressions are compiled into pattern objects, which have methods for various operations such as searching for pattern matches or performing string substitutions. >>> import re >>> p = re.compile('ab*') >>> p re.compile('ab*') *note re.compile(): 44a. also accepts an optional `flags' argument, used to enable various special features and syntax variations. We’ll go over the available settings later, but for now a single example will do: >>> p = re.compile('ab*', re.IGNORECASE) The RE is passed to *note re.compile(): 44a. as a string. REs are handled as strings because regular expressions aren’t part of the core Python language, and no special syntax was created for expressing them. (There are applications that don’t need REs at all, so there’s no need to bloat the language specification by including them.) Instead, the *note re: dd. module is simply a C extension module included with Python, just like the *note socket: ef. or *note zlib: 144. modules. Putting REs in strings keeps the Python language simpler, but has one disadvantage which is the topic of the next section.  File: python.info, Node: The Backslash Plague, Next: Performing Matches, Prev: Compiling Regular Expressions, Up: Using Regular Expressions 10.8.3.2 The Backslash Plague ............................. As stated earlier, regular expressions use the backslash character (‘'\'’) to indicate special forms or to allow special characters to be used without invoking their special meaning. This conflicts with Python’s usage of the same character for the same purpose in string literals. Let’s say you want to write a RE that matches the string ‘\section’, which might be found in a LaTeX file. To figure out what to write in the program code, start with the desired string to be matched. Next, you must escape any backslashes and other metacharacters by preceding them with a backslash, resulting in the string ‘\\section’. The resulting string that must be passed to *note re.compile(): 44a. must be ‘\\section’. However, to express this as a Python string literal, both backslashes must be escaped `again'. Characters Stage ----------------------------------------------------------------------- ‘\section’ Text string to be matched ‘\\section’ Escaped backslash for *note re.compile(): 44a. ‘"\\\\section"’ Escaped backslashes for a string literal In short, to match a literal backslash, one has to write ‘'\\\\'’ as the RE string, because the regular expression must be ‘\\’, and each backslash must be expressed as ‘\\’ inside a regular Python string literal. In REs that feature backslashes repeatedly, this leads to lots of repeated backslashes and makes the resulting strings difficult to understand. The solution is to use Python’s raw string notation for regular expressions; backslashes are not handled in any special way in a string literal prefixed with ‘'r'’, so ‘r"\n"’ is a two-character string containing ‘'\'’ and ‘'n'’, while ‘"\n"’ is a one-character string containing a newline. Regular expressions will often be written in Python code using this raw string notation. In addition, special escape sequences that are valid in regular expressions, but not valid as Python string literals, now result in a *note DeprecationWarning: 278. and will eventually become a *note SyntaxError: 458, which means the sequences will be invalid if raw string notation or escaping the backslashes isn’t used. Regular String Raw string ----------------------------------------------- ‘"ab*"’ ‘r"ab*"’ ‘"\\\\section"’ ‘r"\\section"’ ‘"\\w+\\s+\\1"’ ‘r"\w+\s+\1"’  File: python.info, Node: Performing Matches, Next: Module-Level Functions<2>, Prev: The Backslash Plague, Up: Using Regular Expressions 10.8.3.3 Performing Matches ........................... Once you have an object representing a compiled regular expression, what do you do with it? Pattern objects have several methods and attributes. Only the most significant ones will be covered here; consult the *note re: dd. docs for a complete listing. Method/Attribute Purpose --------------------------------------------------------------------------- ‘match()’ Determine if the RE matches at the beginning of the string. ‘search()’ Scan through a string, looking for any location where this RE matches. ‘findall()’ Find all substrings where the RE matches, and returns them as a list. ‘finditer()’ Find all substrings where the RE matches, and returns them as an *note iterator: 112e. *note match(): 1404. and *note search(): 1405. return ‘None’ if no match can be found. If they’re successful, a *note match object: 89d. instance is returned, containing information about the match: where it starts and ends, the substring it matched, and more. You can learn about this by interactively experimenting with the *note re: dd. module. If you have *note tkinter: 10c. available, you may also want to look at Tools/demo/redemo.py(1), a demonstration program included with the Python distribution. It allows you to enter REs and strings, and displays whether the RE matches or fails. ‘redemo.py’ can be quite useful when trying to debug a complicated RE. This HOWTO uses the standard Python interpreter for its examples. First, run the Python interpreter, import the *note re: dd. module, and compile a RE: >>> import re >>> p = re.compile('[a-z]+') >>> p re.compile('[a-z]+') Now, you can try matching various strings against the RE ‘[a-z]+’. An empty string shouldn’t match at all, since ‘+’ means ‘one or more repetitions’. *note match(): 1404. should return ‘None’ in this case, which will cause the interpreter to print no output. You can explicitly print the result of ‘match()’ to make this clear. >>> p.match("") >>> print(p.match("")) None Now, let’s try it on a string that it should match, such as ‘tempo’. In this case, *note match(): 1404. will return a *note match object: 89d, so you should store the result in a variable for later use. >>> m = p.match('tempo') >>> m <re.Match object; span=(0, 5), match='tempo'> Now you can query the *note match object: 89d. for information about the matching string. Match object instances also have several methods and attributes; the most important ones are: Method/Attribute Purpose ------------------------------------------------------------------------ ‘group()’ Return the string matched by the RE ‘start()’ Return the starting position of the match ‘end()’ Return the ending position of the match ‘span()’ Return a tuple containing the (start, end) positions of the match Trying these methods will soon clarify their meaning: >>> m.group() 'tempo' >>> m.start(), m.end() (0, 5) >>> m.span() (0, 5) *note group(): 1419. returns the substring that was matched by the RE. *note start(): 141d. and *note end(): 141e. return the starting and ending index of the match. *note span(): 141f. returns both start and end indexes in a single tuple. Since the *note match(): 1404. method only checks if the RE matches at the start of a string, ‘start()’ will always be zero. However, the *note search(): 1405. method of patterns scans through the string, so the match may not start at zero in that case. >>> print(p.match('::: message')) None >>> m = p.search('::: message'); print(m) <re.Match object; span=(4, 11), match='message'> >>> m.group() 'message' >>> m.span() (4, 11) In actual programs, the most common style is to store the *note match object: 89d. in a variable, and then check if it was ‘None’. This usually looks like: p = re.compile( ... ) m = p.match( 'string goes here' ) if m: print('Match found: ', m.group()) else: print('No match') Two pattern methods return all of the matches for a pattern. *note findall(): 140f. returns a list of matching strings: >>> p = re.compile(r'\d+') >>> p.findall('12 drummers drumming, 11 pipers piping, 10 lords a-leaping') ['12', '11', '10'] The ‘r’ prefix, making the literal a raw string literal, is needed in this example because escape sequences in a normal “cooked” string literal that are not recognized by Python, as opposed to regular expressions, now result in a *note DeprecationWarning: 278. and will eventually become a *note SyntaxError: 458. See *note The Backslash Plague: 3efd. *note findall(): 140f. has to create the entire list before it can be returned as the result. The *note finditer(): 1410. method returns a sequence of *note match object: 89d. instances as an *note iterator: 112e.: >>> iterator = p.finditer('12 drummers drumming, 11 ... 10 ...') >>> iterator <callable_iterator object at 0x...> >>> for match in iterator: ... print(match.span()) ... (0, 2) (22, 24) (29, 31) ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Tools/demo/redemo.py  File: python.info, Node: Module-Level Functions<2>, Next: Compilation Flags, Prev: Performing Matches, Up: Using Regular Expressions 10.8.3.4 Module-Level Functions ............................... You don’t have to create a pattern object and call its methods; the *note re: dd. module also provides top-level functions called *note match(): bb3, *note search(): bb2, *note findall(): 963, *note sub(): 47b, and so forth. These functions take the same arguments as the corresponding pattern method with the RE string added as the first argument, and still return either ‘None’ or a *note match object: 89d. instance. >>> print(re.match(r'From\s+', 'Fromage amk')) None >>> re.match(r'From\s+', 'From amk Thu May 14 19:12:10 1998') <re.Match object; span=(0, 5), match='From '> Under the hood, these functions simply create a pattern object for you and call the appropriate method on it. They also store the compiled object in a cache, so future calls using the same RE won’t need to parse the pattern again and again. Should you use these module-level functions, or should you get the pattern and call its methods yourself? If you’re accessing a regex within a loop, pre-compiling it will save a few function calls. Outside of loops, there’s not much difference thanks to the internal cache.  File: python.info, Node: Compilation Flags, Prev: Module-Level Functions<2>, Up: Using Regular Expressions 10.8.3.5 Compilation Flags .......................... Compilation flags let you modify some aspects of how regular expressions work. Flags are available in the *note re: dd. module under two names, a long name such as ‘IGNORECASE’ and a short, one-letter form such as ‘I’. (If you’re familiar with Perl’s pattern modifiers, the one-letter forms use the same letters; the short form of *note re.VERBOSE: 1408. is *note re.X: 1400, for example.) Multiple flags can be specified by bitwise OR-ing them; ‘re.I | re.M’ sets both the ‘I’ and ‘M’ flags, for example. Here’s a table of the available flags, followed by a more detailed explanation of each one. Flag Meaning --------------------------------------------------------------------------------------- ‘ASCII’, ‘A’ Makes several escapes like ‘\w’, ‘\b’, ‘\s’ and ‘\d’ match only on ASCII characters with the respective property. ‘DOTALL’, ‘S’ Make ‘.’ match any character, including newlines. ‘IGNORECASE’, ‘I’ Do case-insensitive matches. ‘LOCALE’, ‘L’ Do a locale-aware match. ‘MULTILINE’, ‘M’ Multi-line matching, affecting ‘^’ and ‘$’. ‘VERBOSE’, ‘X’ (for ‘extended’) Enable verbose REs, which can be organized more cleanly and understandably. -- Data: I -- Data: IGNORECASE Perform case-insensitive matching; character class and literal strings will match letters by ignoring case. For example, ‘[A-Z]’ will match lowercase letters, too. Full Unicode matching also works unless the ‘ASCII’ flag is used to disable non-ASCII matches. When the Unicode patterns ‘[a-z]’ or ‘[A-Z]’ are used in combination with the ‘IGNORECASE’ flag, they will match the 52 ASCII letters and 4 additional non-ASCII letters: ‘İ’ (U+0130, Latin capital letter I with dot above), ‘ı’ (U+0131, Latin small letter dotless i), ‘ſ’ (U+017F, Latin small letter long s) and ‘K’ (U+212A, Kelvin sign). ‘Spam’ will match ‘'Spam'’, ‘'spam'’, ‘'spAM'’, or ‘'ſpam'’ (the latter is matched only in Unicode mode). This lowercasing doesn’t take the current locale into account; it will if you also set the ‘LOCALE’ flag. -- Data: L -- Data: LOCALE Make ‘\w’, ‘\W’, ‘\b’, ‘\B’ and case-insensitive matching dependent on the current locale instead of the Unicode database. Locales are a feature of the C library intended to help in writing programs that take account of language differences. For example, if you’re processing encoded French text, you’d want to be able to write ‘\w+’ to match words, but ‘\w’ only matches the character class ‘[A-Za-z]’ in bytes patterns; it won’t match bytes corresponding to ‘é’ or ‘ç’. If your system is configured properly and a French locale is selected, certain C functions will tell the program that the byte corresponding to ‘é’ should also be considered a letter. Setting the ‘LOCALE’ flag when compiling a regular expression will cause the resulting compiled object to use these C functions for ‘\w’; this is slower, but also enables ‘\w+’ to match French words as you’d expect. The use of this flag is discouraged in Python 3 as the locale mechanism is very unreliable, it only handles one “culture” at a time, and it only works with 8-bit locales. Unicode matching is already enabled by default in Python 3 for Unicode (str) patterns, and it is able to handle different locales/languages. -- Data: M -- Data: MULTILINE (‘^’ and ‘$’ haven’t been explained yet; they’ll be introduced in section *note More Metacharacters: 3f01.) Usually ‘^’ matches only at the beginning of the string, and ‘$’ matches only at the end of the string and immediately before the newline (if any) at the end of the string. When this flag is specified, ‘^’ matches at the beginning of the string and at the beginning of each line within the string, immediately following each newline. Similarly, the ‘$’ metacharacter matches either at the end of the string and at the end of each line (immediately preceding each newline). -- Data: S -- Data: DOTALL Makes the ‘'.'’ special character match any character at all, including a newline; without this flag, ‘'.'’ will match anything `except' a newline. -- Data: A -- Data: ASCII Make ‘\w’, ‘\W’, ‘\b’, ‘\B’, ‘\s’ and ‘\S’ perform ASCII-only matching instead of full Unicode matching. This is only meaningful for Unicode patterns, and is ignored for byte patterns. -- Data: X -- Data: VERBOSE This flag allows you to write regular expressions that are more readable by granting you more flexibility in how you can format them. When this flag has been specified, whitespace within the RE string is ignored, except when the whitespace is in a character class or preceded by an unescaped backslash; this lets you organize and indent the RE more clearly. This flag also lets you put comments within a RE that will be ignored by the engine; comments are marked by a ‘'#'’ that’s neither in a character class or preceded by an unescaped backslash. For example, here’s a RE that uses *note re.VERBOSE: 1408.; see how much easier it is to read? charref = re.compile(r""" &[#] # Start of a numeric entity reference ( 0[0-7]+ # Octal form | [0-9]+ # Decimal form | x[0-9a-fA-F]+ # Hexadecimal form ) ; # Trailing semicolon """, re.VERBOSE) Without the verbose setting, the RE would look like this: charref = re.compile("&#(0[0-7]+" "|[0-9]+" "|x[0-9a-fA-F]+);") In the above example, Python’s automatic concatenation of string literals has been used to break up the RE into smaller pieces, but it’s still more difficult to understand than the version using *note re.VERBOSE: 1408.  File: python.info, Node: More Pattern Power, Next: Modifying Strings, Prev: Using Regular Expressions, Up: Regular Expression HOWTO 10.8.4 More Pattern Power ------------------------- So far we’ve only covered a part of the features of regular expressions. In this section, we’ll cover some new metacharacters, and how to use groups to retrieve portions of the text that was matched. * Menu: * More Metacharacters:: * Grouping:: * Non-capturing and Named Groups:: * Lookahead Assertions::  File: python.info, Node: More Metacharacters, Next: Grouping, Up: More Pattern Power 10.8.4.1 More Metacharacters ............................ There are some metacharacters that we haven’t covered yet. Most of them will be covered in this section. Some of the remaining metacharacters to be discussed are `zero-width assertions'. They don’t cause the engine to advance through the string; instead, they consume no characters at all, and simply succeed or fail. For example, ‘\b’ is an assertion that the current position is located at a word boundary; the position isn’t changed by the ‘\b’ at all. This means that zero-width assertions should never be repeated, because if they match once at a given location, they can obviously be matched an infinite number of times. ‘|’ Alternation, or the “or” operator. If `A' and `B' are regular expressions, ‘A|B’ will match any string that matches either `A' or `B'. ‘|’ has very low precedence in order to make it work reasonably when you’re alternating multi-character strings. ‘Crow|Servo’ will match either ‘'Crow'’ or ‘'Servo'’, not ‘'Cro'’, a ‘'w'’ or an ‘'S'’, and ‘'ervo'’. To match a literal ‘'|'’, use ‘\|’, or enclose it inside a character class, as in ‘[|]’. ‘^’ Matches at the beginning of lines. Unless the ‘MULTILINE’ flag has been set, this will only match at the beginning of the string. In ‘MULTILINE’ mode, this also matches immediately after each newline within the string. For example, if you wish to match the word ‘From’ only at the beginning of a line, the RE to use is ‘^From’. >>> print(re.search('^From', 'From Here to Eternity')) <re.Match object; span=(0, 4), match='From'> >>> print(re.search('^From', 'Reciting From Memory')) None To match a literal ‘'^'’, use ‘\^’. ‘$’ Matches at the end of a line, which is defined as either the end of the string, or any location followed by a newline character. >>> print(re.search('}$', '{block}')) <re.Match object; span=(6, 7), match='}'> >>> print(re.search('}$', '{block} ')) None >>> print(re.search('}$', '{block}\n')) <re.Match object; span=(6, 7), match='}'> To match a literal ‘'$'’, use ‘\$’ or enclose it inside a character class, as in ‘[$]’. ‘\A’ Matches only at the start of the string. When not in ‘MULTILINE’ mode, ‘\A’ and ‘^’ are effectively the same. In ‘MULTILINE’ mode, they’re different: ‘\A’ still matches only at the beginning of the string, but ‘^’ may match at any location inside the string that follows a newline character. ‘\Z’ Matches only at the end of the string. ‘\b’ Word boundary. This is a zero-width assertion that matches only at the beginning or end of a word. A word is defined as a sequence of alphanumeric characters, so the end of a word is indicated by whitespace or a non-alphanumeric character. The following example matches ‘class’ only when it’s a complete word; it won’t match when it’s contained inside another word. >>> p = re.compile(r'\bclass\b') >>> print(p.search('no class at all')) <re.Match object; span=(3, 8), match='class'> >>> print(p.search('the declassified algorithm')) None >>> print(p.search('one subclass is')) None There are two subtleties you should remember when using this special sequence. First, this is the worst collision between Python’s string literals and regular expression sequences. In Python’s string literals, ‘\b’ is the backspace character, ASCII value 8. If you’re not using raw strings, then Python will convert the ‘\b’ to a backspace, and your RE won’t match as you expect it to. The following example looks the same as our previous RE, but omits the ‘'r'’ in front of the RE string. >>> p = re.compile('\bclass\b') >>> print(p.search('no class at all')) None >>> print(p.search('\b' + 'class' + '\b')) <re.Match object; span=(0, 7), match='\x08class\x08'> Second, inside a character class, where there’s no use for this assertion, ‘\b’ represents the backspace character, for compatibility with Python’s string literals. ‘\B’ Another zero-width assertion, this is the opposite of ‘\b’, only matching when the current position is not at a word boundary.  File: python.info, Node: Grouping, Next: Non-capturing and Named Groups, Prev: More Metacharacters, Up: More Pattern Power 10.8.4.2 Grouping ................. Frequently you need to obtain more information than just whether the RE matched or not. Regular expressions are often used to dissect strings by writing a RE divided into several subgroups which match different components of interest. For example, an RFC-822 header line is divided into a header name and a value, separated by a ‘':'’, like this: From: author@example.com User-Agent: Thunderbird 1.5.0.9 (X11/20061227) MIME-Version: 1.0 To: editor@example.com This can be handled by writing a regular expression which matches an entire header line, and has one group which matches the header name, and another group which matches the header’s value. Groups are marked by the ‘'('’, ‘')'’ metacharacters. ‘'('’ and ‘')'’ have much the same meaning as they do in mathematical expressions; they group together the expressions contained inside them, and you can repeat the contents of a group with a repeating qualifier, such as ‘*’, ‘+’, ‘?’, or ‘{m,n}’. For example, ‘(ab)*’ will match zero or more repetitions of ‘ab’. >>> p = re.compile('(ab)*') >>> print(p.match('ababababab').span()) (0, 10) Groups indicated with ‘'('’, ‘')'’ also capture the starting and ending index of the text that they match; this can be retrieved by passing an argument to *note group(): 1419, *note start(): 141d, *note end(): 141e, and *note span(): 141f. Groups are numbered starting with 0. Group 0 is always present; it’s the whole RE, so *note match object: 89d. methods all have group 0 as their default argument. Later we’ll see how to express groups that don’t capture the span of text that they match. >>> p = re.compile('(a)b') >>> m = p.match('ab') >>> m.group() 'ab' >>> m.group(0) 'ab' Subgroups are numbered from left to right, from 1 upward. Groups can be nested; to determine the number, just count the opening parenthesis characters, going from left to right. >>> p = re.compile('(a(b)c)d') >>> m = p.match('abcd') >>> m.group(0) 'abcd' >>> m.group(1) 'abc' >>> m.group(2) 'b' *note group(): 1419. can be passed multiple group numbers at a time, in which case it will return a tuple containing the corresponding values for those groups. >>> m.group(2,1,2) ('b', 'abc', 'b') The *note groups(): 141b. method returns a tuple containing the strings for all the subgroups, from 1 up to however many there are. >>> m.groups() ('abc', 'b') Backreferences in a pattern allow you to specify that the contents of an earlier capturing group must also be found at the current location in the string. For example, ‘\1’ will succeed if the exact contents of group 1 can be found at the current position, and fails otherwise. Remember that Python’s string literals also use a backslash followed by numbers to allow including arbitrary characters in a string, so be sure to use a raw string when incorporating backreferences in a RE. For example, the following RE detects doubled words in a string. >>> p = re.compile(r'\b(\w+)\s+\1\b') >>> p.search('Paris in the the spring').group() 'the the' Backreferences like this aren’t often useful for just searching through a string — there are few text formats which repeat data in this way — but you’ll soon find out that they’re `very' useful when performing string substitutions.  File: python.info, Node: Non-capturing and Named Groups, Next: Lookahead Assertions, Prev: Grouping, Up: More Pattern Power 10.8.4.3 Non-capturing and Named Groups ....................................... Elaborate REs may use many groups, both to capture substrings of interest, and to group and structure the RE itself. In complex REs, it becomes difficult to keep track of the group numbers. There are two features which help with this problem. Both of them use a common syntax for regular expression extensions, so we’ll look at that first. Perl 5 is well known for its powerful additions to standard regular expressions. For these new features the Perl developers couldn’t choose new single-keystroke metacharacters or new special sequences beginning with ‘\’ without making Perl’s regular expressions confusingly different from standard REs. If they chose ‘&’ as a new metacharacter, for example, old expressions would be assuming that ‘&’ was a regular character and wouldn’t have escaped it by writing ‘\&’ or ‘[&]’. The solution chosen by the Perl developers was to use ‘(?...)’ as the extension syntax. ‘?’ immediately after a parenthesis was a syntax error because the ‘?’ would have nothing to repeat, so this didn’t introduce any compatibility problems. The characters immediately after the ‘?’ indicate what extension is being used, so ‘(?=foo)’ is one thing (a positive lookahead assertion) and ‘(?:foo)’ is something else (a non-capturing group containing the subexpression ‘foo’). Python supports several of Perl’s extensions and adds an extension syntax to Perl’s extension syntax. If the first character after the question mark is a ‘P’, you know that it’s an extension that’s specific to Python. Now that we’ve looked at the general extension syntax, we can return to the features that simplify working with groups in complex REs. Sometimes you’ll want to use a group to denote a part of a regular expression, but aren’t interested in retrieving the group’s contents. You can make this fact explicit by using a non-capturing group: ‘(?:...)’, where you can replace the ‘...’ with any other regular expression. >>> m = re.match("([abc])+", "abc") >>> m.groups() ('c',) >>> m = re.match("(?:[abc])+", "abc") >>> m.groups() () Except for the fact that you can’t retrieve the contents of what the group matched, a non-capturing group behaves exactly the same as a capturing group; you can put anything inside it, repeat it with a repetition metacharacter such as ‘*’, and nest it within other groups (capturing or non-capturing). ‘(?:...)’ is particularly useful when modifying an existing pattern, since you can add new groups without changing how all the other groups are numbered. It should be mentioned that there’s no performance difference in searching between capturing and non-capturing groups; neither form is any faster than the other. A more significant feature is named groups: instead of referring to them by numbers, groups can be referenced by a name. The syntax for a named group is one of the Python-specific extensions: ‘(?P<name>...)’. `name' is, obviously, the name of the group. Named groups behave exactly like capturing groups, and additionally associate a name with a group. The *note match object: 89d. methods that deal with capturing groups all accept either integers that refer to the group by number or strings that contain the desired group’s name. Named groups are still given numbers, so you can retrieve information about a group in two ways: >>> p = re.compile(r'(?P<word>\b\w+\b)') >>> m = p.search( '(((( Lots of punctuation )))' ) >>> m.group('word') 'Lots' >>> m.group(1) 'Lots' Additionally, you can retrieve named groups as a dictionary with *note groupdict(): 141c.: >>> m = re.match(r'(?P<first>\w+) (?P<last>\w+)', 'Jane Doe') >>> m.groupdict() {'first': 'Jane', 'last': 'Doe'} Named groups are handy because they let you use easily-remembered names, instead of having to remember numbers. Here’s an example RE from the *note imaplib: 98. module: InternalDate = re.compile(r'INTERNALDATE "' r'(?P<day>[ 123][0-9])-(?P<mon>[A-Z][a-z][a-z])-' r'(?P<year>[0-9][0-9][0-9][0-9])' r' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])' r' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])' r'"') It’s obviously much easier to retrieve ‘m.group('zonem')’, instead of having to remember to retrieve group 9. The syntax for backreferences in an expression such as ‘(...)\1’ refers to the number of the group. There’s naturally a variant that uses the group name instead of the number. This is another Python extension: ‘(?P=name)’ indicates that the contents of the group called `name' should again be matched at the current point. The regular expression for finding doubled words, ‘\b(\w+)\s+\1\b’ can also be written as ‘\b(?P<word>\w+)\s+(?P=word)\b’: >>> p = re.compile(r'\b(?P<word>\w+)\s+(?P=word)\b') >>> p.search('Paris in the the spring').group() 'the the'  File: python.info, Node: Lookahead Assertions, Prev: Non-capturing and Named Groups, Up: More Pattern Power 10.8.4.4 Lookahead Assertions ............................. Another zero-width assertion is the lookahead assertion. Lookahead assertions are available in both positive and negative form, and look like this: ‘(?=...)’ Positive lookahead assertion. This succeeds if the contained regular expression, represented here by ‘...’, successfully matches at the current location, and fails otherwise. But, once the contained expression has been tried, the matching engine doesn’t advance at all; the rest of the pattern is tried right where the assertion started. ‘(?!...)’ Negative lookahead assertion. This is the opposite of the positive assertion; it succeeds if the contained expression `doesn’t' match at the current position in the string. To make this concrete, let’s look at a case where a lookahead is useful. Consider a simple pattern to match a filename and split it apart into a base name and an extension, separated by a ‘.’. For example, in ‘news.rc’, ‘news’ is the base name, and ‘rc’ is the filename’s extension. The pattern to match this is quite simple: ‘.*[.].*$’ Notice that the ‘.’ needs to be treated specially because it’s a metacharacter, so it’s inside a character class to only match that specific character. Also notice the trailing ‘$’; this is added to ensure that all the rest of the string must be included in the extension. This regular expression matches ‘foo.bar’ and ‘autoexec.bat’ and ‘sendmail.cf’ and ‘printers.conf’. Now, consider complicating the problem a bit; what if you want to match filenames where the extension is not ‘bat’? Some incorrect attempts: ‘.*[.][^b].*$’ The first attempt above tries to exclude ‘bat’ by requiring that the first character of the extension is not a ‘b’. This is wrong, because the pattern also doesn’t match ‘foo.bar’. ‘.*[.]([^b]..|.[^a].|..[^t])$’ The expression gets messier when you try to patch up the first solution by requiring one of the following cases to match: the first character of the extension isn’t ‘b’; the second character isn’t ‘a’; or the third character isn’t ‘t’. This accepts ‘foo.bar’ and rejects ‘autoexec.bat’, but it requires a three-letter extension and won’t accept a filename with a two-letter extension such as ‘sendmail.cf’. We’ll complicate the pattern again in an effort to fix it. ‘.*[.]([^b].?.?|.[^a]?.?|..?[^t]?)$’ In the third attempt, the second and third letters are all made optional in order to allow matching extensions shorter than three characters, such as ‘sendmail.cf’. The pattern’s getting really complicated now, which makes it hard to read and understand. Worse, if the problem changes and you want to exclude both ‘bat’ and ‘exe’ as extensions, the pattern would get even more complicated and confusing. A negative lookahead cuts through all this confusion: ‘.*[.](?!bat$)[^.]*$’ The negative lookahead means: if the expression ‘bat’ doesn’t match at this point, try the rest of the pattern; if ‘bat$’ does match, the whole pattern will fail. The trailing ‘$’ is required to ensure that something like ‘sample.batch’, where the extension only starts with ‘bat’, will be allowed. The ‘[^.]*’ makes sure that the pattern works when there are multiple dots in the filename. Excluding another filename extension is now easy; simply add it as an alternative inside the assertion. The following pattern excludes filenames that end in either ‘bat’ or ‘exe’: ‘.*[.](?!bat$|exe$)[^.]*$’  File: python.info, Node: Modifying Strings, Next: Common Problems, Prev: More Pattern Power, Up: Regular Expression HOWTO 10.8.5 Modifying Strings ------------------------ Up to this point, we’ve simply performed searches against a static string. Regular expressions are also commonly used to modify strings in various ways, using the following pattern methods: Method/Attribute Purpose --------------------------------------------------------------------------- ‘split()’ Split the string into a list, splitting it wherever the RE matches ‘sub()’ Find all substrings where the RE matches, and replace them with a different string ‘subn()’ Does the same thing as ‘sub()’, but returns the new string and the number of replacements * Menu: * Splitting Strings:: * Search and Replace::  File: python.info, Node: Splitting Strings, Next: Search and Replace, Up: Modifying Strings 10.8.5.1 Splitting Strings .......................... The *note split(): 140e. method of a pattern splits a string apart wherever the RE matches, returning a list of the pieces. It’s similar to the *note split(): 7a1. method of strings but provides much more generality in the delimiters that you can split by; string ‘split()’ only supports splitting by whitespace or by a fixed string. As you’d expect, there’s a module-level *note re.split(): 3ca. function, too. -- Method: .split (string[, maxsplit=0]) Split `string' by the matches of the regular expression. If capturing parentheses are used in the RE, then their contents will also be returned as part of the resulting list. If `maxsplit' is nonzero, at most `maxsplit' splits are performed. You can limit the number of splits made, by passing a value for `maxsplit'. When `maxsplit' is nonzero, at most `maxsplit' splits will be made, and the remainder of the string is returned as the final element of the list. In the following example, the delimiter is any sequence of non-alphanumeric characters. >>> p = re.compile(r'\W+') >>> p.split('This is a test, short and sweet, of split().') ['This', 'is', 'a', 'test', 'short', 'and', 'sweet', 'of', 'split', ''] >>> p.split('This is a test, short and sweet, of split().', 3) ['This', 'is', 'a', 'test, short and sweet, of split().'] Sometimes you’re not only interested in what the text between delimiters is, but also need to know what the delimiter was. If capturing parentheses are used in the RE, then their values are also returned as part of the list. Compare the following calls: >>> p = re.compile(r'\W+') >>> p2 = re.compile(r'(\W+)') >>> p.split('This... is a test.') ['This', 'is', 'a', 'test', ''] >>> p2.split('This... is a test.') ['This', '... ', 'is', ' ', 'a', ' ', 'test', '.', ''] The module-level function *note re.split(): 3ca. adds the RE to be used as the first argument, but is otherwise the same. >>> re.split(r'[\W]+', 'Words, words, words.') ['Words', 'words', 'words', ''] >>> re.split(r'([\W]+)', 'Words, words, words.') ['Words', ', ', 'words', ', ', 'words', '.', ''] >>> re.split(r'[\W]+', 'Words, words, words.', 1) ['Words', 'words, words.']  File: python.info, Node: Search and Replace, Prev: Splitting Strings, Up: Modifying Strings 10.8.5.2 Search and Replace ........................... Another common task is to find all the matches for a pattern, and replace them with a different string. The *note sub(): 1411. method takes a replacement value, which can be either a string or a function, and the string to be processed. -- Method: .sub (replacement, string[, count=0]) Returns the string obtained by replacing the leftmost non-overlapping occurrences of the RE in `string' by the replacement `replacement'. If the pattern isn’t found, `string' is returned unchanged. The optional argument `count' is the maximum number of pattern occurrences to be replaced; `count' must be a non-negative integer. The default value of 0 means to replace all occurrences. Here’s a simple example of using the *note sub(): 1411. method. It replaces colour names with the word ‘colour’: >>> p = re.compile('(blue|white|red)') >>> p.sub('colour', 'blue socks and red shoes') 'colour socks and colour shoes' >>> p.sub('colour', 'blue socks and red shoes', count=1) 'colour socks and red shoes' The *note subn(): 1412. method does the same work, but returns a 2-tuple containing the new string value and the number of replacements that were performed: >>> p = re.compile('(blue|white|red)') >>> p.subn('colour', 'blue socks and red shoes') ('colour socks and colour shoes', 2) >>> p.subn('colour', 'no colours at all') ('no colours at all', 0) Empty matches are replaced only when they’re not adjacent to a previous empty match. >>> p = re.compile('x*') >>> p.sub('-', 'abxd') '-a-b--d-' If `replacement' is a string, any backslash escapes in it are processed. That is, ‘\n’ is converted to a single newline character, ‘\r’ is converted to a carriage return, and so forth. Unknown escapes such as ‘\&’ are left alone. Backreferences, such as ‘\6’, are replaced with the substring matched by the corresponding group in the RE. This lets you incorporate portions of the original text in the resulting replacement string. This example matches the word ‘section’ followed by a string enclosed in ‘{’, ‘}’, and changes ‘section’ to ‘subsection’: >>> p = re.compile('section{ ( [^}]* ) }', re.VERBOSE) >>> p.sub(r'subsection{\1}','section{First} section{second}') 'subsection{First} subsection{second}' There’s also a syntax for referring to named groups as defined by the ‘(?P<name>...)’ syntax. ‘\g<name>’ will use the substring matched by the group named ‘name’, and ‘\g<number>’ uses the corresponding group number. ‘\g<2>’ is therefore equivalent to ‘\2’, but isn’t ambiguous in a replacement string such as ‘\g<2>0’. (‘\20’ would be interpreted as a reference to group 20, not a reference to group 2 followed by the literal character ‘'0'’.) The following substitutions are all equivalent, but use all three variations of the replacement string. >>> p = re.compile('section{ (?P<name> [^}]* ) }', re.VERBOSE) >>> p.sub(r'subsection{\1}','section{First}') 'subsection{First}' >>> p.sub(r'subsection{\g<1>}','section{First}') 'subsection{First}' >>> p.sub(r'subsection{\g<name>}','section{First}') 'subsection{First}' `replacement' can also be a function, which gives you even more control. If `replacement' is a function, the function is called for every non-overlapping occurrence of `pattern'. On each call, the function is passed a *note match object: 89d. argument for the match and can use this information to compute the desired replacement string and return it. In the following example, the replacement function translates decimals into hexadecimal: >>> def hexrepl(match): ... "Return the hex string for a decimal number" ... value = int(match.group()) ... return hex(value) ... >>> p = re.compile(r'\d+') >>> p.sub(hexrepl, 'Call 65490 for printing, 49152 for user code.') 'Call 0xffd2 for printing, 0xc000 for user code.' When using the module-level *note re.sub(): 47b. function, the pattern is passed as the first argument. The pattern may be provided as an object or as a string; if you need to specify regular expression flags, you must either use a pattern object as the first parameter, or use embedded modifiers in the pattern string, e.g. ‘sub("(?i)b+", "x", "bbbb BBBB")’ returns ‘'x x'’.  File: python.info, Node: Common Problems, Next: Feedback, Prev: Modifying Strings, Up: Regular Expression HOWTO 10.8.6 Common Problems ---------------------- Regular expressions are a powerful tool for some applications, but in some ways their behaviour isn’t intuitive and at times they don’t behave the way you may expect them to. This section will point out some of the most common pitfalls. * Menu: * Use String Methods:: * match() versus search(): match versus search. * Greedy versus Non-Greedy:: * Using re.VERBOSE: Using re VERBOSE.  File: python.info, Node: Use String Methods, Next: match versus search, Up: Common Problems 10.8.6.1 Use String Methods ........................... Sometimes using the *note re: dd. module is a mistake. If you’re matching a fixed string, or a single character class, and you’re not using any *note re: dd. features such as the *note IGNORECASE: 1407. flag, then the full power of regular expressions may not be required. Strings have several methods for performing operations with fixed strings and they’re usually much faster, because the implementation is a single small C loop that’s been optimized for the purpose, instead of the large, more generalized regular expression engine. One example might be replacing a single fixed string with another one; for example, you might replace ‘word’ with ‘deed’. *note re.sub(): 47b. seems like the function to use for this, but consider the *note replace(): 12ff. method. Note that ‘replace()’ will also replace ‘word’ inside words, turning ‘swordfish’ into ‘sdeedfish’, but the naive RE ‘word’ would have done that, too. (To avoid performing the substitution on parts of words, the pattern would have to be ‘\bword\b’, in order to require that ‘word’ have a word boundary on either side. This takes the job beyond ‘replace()’’s abilities.) Another common task is deleting every occurrence of a single character from a string or replacing it with another single character. You might do this with something like ‘re.sub('\n', ' ', S)’, but *note translate(): 12fe. is capable of doing both tasks and will be faster than any regular expression operation can be. In short, before turning to the *note re: dd. module, consider whether your problem can be solved with a faster and simpler string method.  File: python.info, Node: match versus search, Next: Greedy versus Non-Greedy, Prev: Use String Methods, Up: Common Problems 10.8.6.2 match() versus search() ................................ The *note match(): bb3. function only checks if the RE matches at the beginning of the string while *note search(): bb2. will scan forward through the string for a match. It’s important to keep this distinction in mind. Remember, ‘match()’ will only report a successful match which will start at 0; if the match wouldn’t start at zero, ‘match()’ will `not' report it. >>> print(re.match('super', 'superstition').span()) (0, 5) >>> print(re.match('super', 'insuperable')) None On the other hand, *note search(): bb2. will scan forward through the string, reporting the first match it finds. >>> print(re.search('super', 'superstition').span()) (0, 5) >>> print(re.search('super', 'insuperable').span()) (2, 7) Sometimes you’ll be tempted to keep using *note re.match(): bb3, and just add ‘.*’ to the front of your RE. Resist this temptation and use *note re.search(): bb2. instead. The regular expression compiler does some analysis of REs in order to speed up the process of looking for a match. One such analysis figures out what the first character of a match must be; for example, a pattern starting with ‘Crow’ must match starting with a ‘'C'’. The analysis lets the engine quickly scan through the string looking for the starting character, only trying the full match if a ‘'C'’ is found. Adding ‘.*’ defeats this optimization, requiring scanning to the end of the string and then backtracking to find a match for the rest of the RE. Use *note re.search(): bb2. instead.  File: python.info, Node: Greedy versus Non-Greedy, Next: Using re VERBOSE, Prev: match versus search, Up: Common Problems 10.8.6.3 Greedy versus Non-Greedy ................................. When repeating a regular expression, as in ‘a*’, the resulting action is to consume as much of the pattern as possible. This fact often bites you when you’re trying to match a pair of balanced delimiters, such as the angle brackets surrounding an HTML tag. The naive pattern for matching a single HTML tag doesn’t work because of the greedy nature of ‘.*’. >>> s = '<html><head><title>Title' >>> len(s) 32 >>> print(re.match('<.*>', s).span()) (0, 32) >>> print(re.match('<.*>', s).group()) Title The RE matches the ‘'<'’ in ‘''’, and the ‘.*’ consumes the rest of the string. There’s still more left in the RE, though, and the ‘>’ can’t match at the end of the string, so the regular expression engine has to backtrack character by character until it finds a match for the ‘>’. The final match extends from the ‘'<'’ in ‘''’ to the ‘'>'’ in ‘''’, which isn’t what you want. In this case, the solution is to use the non-greedy qualifiers ‘*?’, ‘+?’, ‘??’, or ‘{m,n}?’, which match as `little' text as possible. In the above example, the ‘'>'’ is tried immediately after the first ‘'<'’ matches, and when it fails, the engine advances a character at a time, retrying the ‘'>'’ at every step. This produces just the right result: >>> print(re.match('<.*?>', s).group()) (Note that parsing HTML or XML with regular expressions is painful. Quick-and-dirty patterns will handle common cases, but HTML and XML have special cases that will break the obvious regular expression; by the time you’ve written a regular expression that handles all of the possible cases, the patterns will be `very' complicated. Use an HTML or XML parser module for such tasks.)  File: python.info, Node: Using re VERBOSE, Prev: Greedy versus Non-Greedy, Up: Common Problems 10.8.6.4 Using re.VERBOSE ......................... By now you’ve probably noticed that regular expressions are a very compact notation, but they’re not terribly readable. REs of moderate complexity can become lengthy collections of backslashes, parentheses, and metacharacters, making them difficult to read and understand. For such REs, specifying the *note re.VERBOSE: 1408. flag when compiling the regular expression can be helpful, because it allows you to format the regular expression more clearly. The ‘re.VERBOSE’ flag has several effects. Whitespace in the regular expression that `isn’t' inside a character class is ignored. This means that an expression such as ‘dog | cat’ is equivalent to the less readable ‘dog|cat’, but ‘[a b]’ will still match the characters ‘'a'’, ‘'b'’, or a space. In addition, you can also put comments inside a RE; comments extend from a ‘#’ character to the next newline. When used with triple-quoted strings, this enables REs to be formatted more neatly: pat = re.compile(r""" \s* # Skip leading whitespace (?P

    [^:]+) # Header name \s* : # Whitespace, and a colon (?P.*?) # The header's value -- *? used to # lose the following trailing whitespace \s*$ # Trailing whitespace to end-of-line """, re.VERBOSE) This is far more readable than: pat = re.compile(r"\s*(?P
    [^:]+)\s*:(?P.*?)\s*$")  File: python.info, Node: Feedback, Prev: Common Problems, Up: Regular Expression HOWTO 10.8.7 Feedback --------------- Regular expressions are a complicated topic. Did this document help you understand them? Were there parts that were unclear, or Problems you encountered that weren’t covered here? If so, please send suggestions for improvements to the author. The most complete book on regular expressions is almost certainly Jeffrey Friedl’s Mastering Regular Expressions, published by O’Reilly. Unfortunately, it exclusively concentrates on Perl and Java’s flavours of regular expressions, and doesn’t contain any Python material at all, so it won’t be useful as a reference for programming in Python. (The first edition covered Python’s now-removed ‘regex’ module, which won’t help you much.) Consider checking it out from your library.  File: python.info, Node: Socket Programming HOWTO, Next: Sorting HOW TO, Prev: Regular Expression HOWTO, Up: Python HOWTOs 10.9 Socket Programming HOWTO ============================= Author: Gordon McMillan Abstract ........ Sockets are used nearly everywhere, but are one of the most severely misunderstood technologies around. This is a 10,000 foot overview of sockets. It’s not really a tutorial - you’ll still have work to do in getting things operational. It doesn’t cover the fine points (and there are a lot of them), but I hope it will give you enough background to begin using them decently. * Menu: * Sockets:: * Creating a Socket:: * Using a Socket:: * Disconnecting:: * Non-blocking Sockets::  File: python.info, Node: Sockets, Next: Creating a Socket, Up: Socket Programming HOWTO 10.9.1 Sockets -------------- I’m only going to talk about INET (i.e. IPv4) sockets, but they account for at least 99% of the sockets in use. And I’ll only talk about STREAM (i.e. TCP) sockets - unless you really know what you’re doing (in which case this HOWTO isn’t for you!), you’ll get better behavior and performance from a STREAM socket than anything else. I will try to clear up the mystery of what a socket is, as well as some hints on how to work with blocking and non-blocking sockets. But I’ll start by talking about blocking sockets. You’ll need to know how they work before dealing with non-blocking sockets. Part of the trouble with understanding these things is that “socket” can mean a number of subtly different things, depending on context. So first, let’s make a distinction between a “client” socket - an endpoint of a conversation, and a “server” socket, which is more like a switchboard operator. The client application (your browser, for example) uses “client” sockets exclusively; the web server it’s talking to uses both “server” sockets and “client” sockets. * Menu: * History::  File: python.info, Node: History, Up: Sockets 10.9.1.1 History ................ Of the various forms of IPC (Inter Process Communication), sockets are by far the most popular. On any given platform, there are likely to be other forms of IPC that are faster, but for cross-platform communication, sockets are about the only game in town. They were invented in Berkeley as part of the BSD flavor of Unix. They spread like wildfire with the Internet. With good reason — the combination of sockets with INET makes talking to arbitrary machines around the world unbelievably easy (at least compared to other schemes).  File: python.info, Node: Creating a Socket, Next: Using a Socket, Prev: Sockets, Up: Socket Programming HOWTO 10.9.2 Creating a Socket ------------------------ Roughly speaking, when you clicked on the link that brought you to this page, your browser did something like the following: # create an INET, STREAMing socket s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # now connect to the web server on port 80 - the normal http port s.connect(("www.python.org", 80)) When the ‘connect’ completes, the socket ‘s’ can be used to send in a request for the text of the page. The same socket will read the reply, and then be destroyed. That’s right, destroyed. Client sockets are normally only used for one exchange (or a small set of sequential exchanges). What happens in the web server is a bit more complex. First, the web server creates a “server socket”: # create an INET, STREAMing socket serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # bind the socket to a public host, and a well-known port serversocket.bind((socket.gethostname(), 80)) # become a server socket serversocket.listen(5) A couple things to notice: we used ‘socket.gethostname()’ so that the socket would be visible to the outside world. If we had used ‘s.bind(('localhost', 80))’ or ‘s.bind(('127.0.0.1', 80))’ we would still have a “server” socket, but one that was only visible within the same machine. ‘s.bind(('', 80))’ specifies that the socket is reachable by any address the machine happens to have. A second thing to note: low number ports are usually reserved for “well known” services (HTTP, SNMP etc). If you’re playing around, use a nice high number (4 digits). Finally, the argument to ‘listen’ tells the socket library that we want it to queue up as many as 5 connect requests (the normal max) before refusing outside connections. If the rest of the code is written properly, that should be plenty. Now that we have a “server” socket, listening on port 80, we can enter the mainloop of the web server: while True: # accept connections from outside (clientsocket, address) = serversocket.accept() # now do something with the clientsocket # in this case, we'll pretend this is a threaded server ct = client_thread(clientsocket) ct.run() There’s actually 3 general ways in which this loop could work - dispatching a thread to handle ‘clientsocket’, create a new process to handle ‘clientsocket’, or restructure this app to use non-blocking sockets, and multiplex between our “server” socket and any active ‘clientsocket’s using ‘select’. More about that later. The important thing to understand now is this: this is `all' a “server” socket does. It doesn’t send any data. It doesn’t receive any data. It just produces “client” sockets. Each ‘clientsocket’ is created in response to some `other' “client” socket doing a ‘connect()’ to the host and port we’re bound to. As soon as we’ve created that ‘clientsocket’, we go back to listening for more connections. The two “clients” are free to chat it up - they are using some dynamically allocated port which will be recycled when the conversation ends. * Menu: * IPC::  File: python.info, Node: IPC, Up: Creating a Socket 10.9.2.1 IPC ............ If you need fast IPC between two processes on one machine, you should look into pipes or shared memory. If you do decide to use AF_INET sockets, bind the “server” socket to ‘'localhost'’. On most platforms, this will take a shortcut around a couple of layers of network code and be quite a bit faster. See also ........ The *note multiprocessing: b7. integrates cross-platform IPC into a higher-level API.  File: python.info, Node: Using a Socket, Next: Disconnecting, Prev: Creating a Socket, Up: Socket Programming HOWTO 10.9.3 Using a Socket --------------------- The first thing to note, is that the web browser’s “client” socket and the web server’s “client” socket are identical beasts. That is, this is a “peer to peer” conversation. Or to put it another way, `as the designer, you will have to decide what the rules of etiquette are for a conversation'. Normally, the ‘connect’ing socket starts the conversation, by sending in a request, or perhaps a signon. But that’s a design decision - it’s not a rule of sockets. Now there are two sets of verbs to use for communication. You can use ‘send’ and ‘recv’, or you can transform your client socket into a file-like beast and use ‘read’ and ‘write’. The latter is the way Java presents its sockets. I’m not going to talk about it here, except to warn you that you need to use ‘flush’ on sockets. These are buffered “files”, and a common mistake is to ‘write’ something, and then ‘read’ for a reply. Without a ‘flush’ in there, you may wait forever for the reply, because the request may still be in your output buffer. Now we come to the major stumbling block of sockets - ‘send’ and ‘recv’ operate on the network buffers. They do not necessarily handle all the bytes you hand them (or expect from them), because their major focus is handling the network buffers. In general, they return when the associated network buffers have been filled (‘send’) or emptied (‘recv’). They then tell you how many bytes they handled. It is `your' responsibility to call them again until your message has been completely dealt with. When a ‘recv’ returns 0 bytes, it means the other side has closed (or is in the process of closing) the connection. You will not receive any more data on this connection. Ever. You may be able to send data successfully; I’ll talk more about this later. A protocol like HTTP uses a socket for only one transfer. The client sends a request, then reads a reply. That’s it. The socket is discarded. This means that a client can detect the end of the reply by receiving 0 bytes. But if you plan to reuse your socket for further transfers, you need to realize that `there is no' EOT (End of Transfer) `on a socket.' I repeat: if a socket ‘send’ or ‘recv’ returns after handling 0 bytes, the connection has been broken. If the connection has `not' been broken, you may wait on a ‘recv’ forever, because the socket will `not' tell you that there’s nothing more to read (for now). Now if you think about that a bit, you’ll come to realize a fundamental truth of sockets: `messages must either be fixed length' (yuck), `or be delimited' (shrug), `or indicate how long they are' (much better), `or end by shutting down the connection'. The choice is entirely yours, (but some ways are righter than others). Assuming you don’t want to end the connection, the simplest solution is a fixed length message: class MySocket: """demonstration class only - coded for clarity, not efficiency """ def __init__(self, sock=None): if sock is None: self.sock = socket.socket( socket.AF_INET, socket.SOCK_STREAM) else: self.sock = sock def connect(self, host, port): self.sock.connect((host, port)) def mysend(self, msg): totalsent = 0 while totalsent < MSGLEN: sent = self.sock.send(msg[totalsent:]) if sent == 0: raise RuntimeError("socket connection broken") totalsent = totalsent + sent def myreceive(self): chunks = [] bytes_recd = 0 while bytes_recd < MSGLEN: chunk = self.sock.recv(min(MSGLEN - bytes_recd, 2048)) if chunk == b'': raise RuntimeError("socket connection broken") chunks.append(chunk) bytes_recd = bytes_recd + len(chunk) return b''.join(chunks) The sending code here is usable for almost any messaging scheme - in Python you send strings, and you can use ‘len()’ to determine its length (even if it has embedded ‘\0’ characters). It’s mostly the receiving code that gets more complex. (And in C, it’s not much worse, except you can’t use ‘strlen’ if the message has embedded ‘\0’s.) The easiest enhancement is to make the first character of the message an indicator of message type, and have the type determine the length. Now you have two ‘recv’s - the first to get (at least) that first character so you can look up the length, and the second in a loop to get the rest. If you decide to go the delimited route, you’ll be receiving in some arbitrary chunk size, (4096 or 8192 is frequently a good match for network buffer sizes), and scanning what you’ve received for a delimiter. One complication to be aware of: if your conversational protocol allows multiple messages to be sent back to back (without some kind of reply), and you pass ‘recv’ an arbitrary chunk size, you may end up reading the start of a following message. You’ll need to put that aside and hold onto it, until it’s needed. Prefixing the message with its length (say, as 5 numeric characters) gets more complex, because (believe it or not), you may not get all 5 characters in one ‘recv’. In playing around, you’ll get away with it; but in high network loads, your code will very quickly break unless you use two ‘recv’ loops - the first to determine the length, the second to get the data part of the message. Nasty. This is also when you’ll discover that ‘send’ does not always manage to get rid of everything in one pass. And despite having read this, you will eventually get bit by it! In the interests of space, building your character, (and preserving my competitive position), these enhancements are left as an exercise for the reader. Lets move on to cleaning up. * Menu: * Binary Data::  File: python.info, Node: Binary Data, Up: Using a Socket 10.9.3.1 Binary Data .................... It is perfectly possible to send binary data over a socket. The major problem is that not all machines use the same formats for binary data. For example, a Motorola chip will represent a 16 bit integer with the value 1 as the two hex bytes 00 01. Intel and DEC, however, are byte-reversed - that same 1 is 01 00. Socket libraries have calls for converting 16 and 32 bit integers - ‘ntohl, htonl, ntohs, htons’ where “n” means `network' and “h” means `host', “s” means `short' and “l” means `long'. Where network order is host order, these do nothing, but where the machine is byte-reversed, these swap the bytes around appropriately. In these days of 32 bit machines, the ascii representation of binary data is frequently smaller than the binary representation. That’s because a surprising amount of the time, all those longs have the value 0, or maybe 1. The string “0” would be two bytes, while binary is four. Of course, this doesn’t fit well with fixed-length messages. Decisions, decisions.  File: python.info, Node: Disconnecting, Next: Non-blocking Sockets, Prev: Using a Socket, Up: Socket Programming HOWTO 10.9.4 Disconnecting -------------------- Strictly speaking, you’re supposed to use ‘shutdown’ on a socket before you ‘close’ it. The ‘shutdown’ is an advisory to the socket at the other end. Depending on the argument you pass it, it can mean “I’m not going to send anymore, but I’ll still listen”, or “I’m not listening, good riddance!”. Most socket libraries, however, are so used to programmers neglecting to use this piece of etiquette that normally a ‘close’ is the same as ‘shutdown(); close()’. So in most situations, an explicit ‘shutdown’ is not needed. One way to use ‘shutdown’ effectively is in an HTTP-like exchange. The client sends a request and then does a ‘shutdown(1)’. This tells the server “This client is done sending, but can still receive.” The server can detect “EOF” by a receive of 0 bytes. It can assume it has the complete request. The server sends a reply. If the ‘send’ completes successfully then, indeed, the client was still receiving. Python takes the automatic shutdown a step further, and says that when a socket is garbage collected, it will automatically do a ‘close’ if it’s needed. But relying on this is a very bad habit. If your socket just disappears without doing a ‘close’, the socket at the other end may hang indefinitely, thinking you’re just being slow. `Please' ‘close’ your sockets when you’re done. * Menu: * When Sockets Die::  File: python.info, Node: When Sockets Die, Up: Disconnecting 10.9.4.1 When Sockets Die ......................... Probably the worst thing about using blocking sockets is what happens when the other side comes down hard (without doing a ‘close’). Your socket is likely to hang. TCP is a reliable protocol, and it will wait a long, long time before giving up on a connection. If you’re using threads, the entire thread is essentially dead. There’s not much you can do about it. As long as you aren’t doing something dumb, like holding a lock while doing a blocking read, the thread isn’t really consuming much in the way of resources. Do `not' try to kill the thread - part of the reason that threads are more efficient than processes is that they avoid the overhead associated with the automatic recycling of resources. In other words, if you do manage to kill the thread, your whole process is likely to be screwed up.  File: python.info, Node: Non-blocking Sockets, Prev: Disconnecting, Up: Socket Programming HOWTO 10.9.5 Non-blocking Sockets --------------------------- If you’ve understood the preceding, you already know most of what you need to know about the mechanics of using sockets. You’ll still use the same calls, in much the same ways. It’s just that, if you do it right, your app will be almost inside-out. In Python, you use ‘socket.setblocking(0)’ to make it non-blocking. In C, it’s more complex, (for one thing, you’ll need to choose between the BSD flavor ‘O_NONBLOCK’ and the almost indistinguishable POSIX flavor ‘O_NDELAY’, which is completely different from ‘TCP_NODELAY’), but it’s the exact same idea. You do this after creating the socket, but before using it. (Actually, if you’re nuts, you can switch back and forth.) The major mechanical difference is that ‘send’, ‘recv’, ‘connect’ and ‘accept’ can return without having done anything. You have (of course) a number of choices. You can check return code and error codes and generally drive yourself crazy. If you don’t believe me, try it sometime. Your app will grow large, buggy and suck CPU. So let’s skip the brain-dead solutions and do it right. Use ‘select’. In C, coding ‘select’ is fairly complex. In Python, it’s a piece of cake, but it’s close enough to the C version that if you understand ‘select’ in Python, you’ll have little trouble with it in C: ready_to_read, ready_to_write, in_error = \ select.select( potential_readers, potential_writers, potential_errs, timeout) You pass ‘select’ three lists: the first contains all sockets that you might want to try reading; the second all the sockets you might want to try writing to, and the last (normally left empty) those that you want to check for errors. You should note that a socket can go into more than one list. The ‘select’ call is blocking, but you can give it a timeout. This is generally a sensible thing to do - give it a nice long timeout (say a minute) unless you have good reason to do otherwise. In return, you will get three lists. They contain the sockets that are actually readable, writable and in error. Each of these lists is a subset (possibly empty) of the corresponding list you passed in. If a socket is in the output readable list, you can be as-close-to-certain-as-we-ever-get-in-this-business that a ‘recv’ on that socket will return `something'. Same idea for the writable list. You’ll be able to send `something'. Maybe not all you want to, but `something' is better than nothing. (Actually, any reasonably healthy socket will return as writable - it just means outbound network buffer space is available.) If you have a “server” socket, put it in the potential_readers list. If it comes out in the readable list, your ‘accept’ will (almost certainly) work. If you have created a new socket to ‘connect’ to someone else, put it in the potential_writers list. If it shows up in the writable list, you have a decent chance that it has connected. Actually, ‘select’ can be handy even with blocking sockets. It’s one way of determining whether you will block - the socket returns as readable when there’s something in the buffers. However, this still doesn’t help with the problem of determining whether the other end is done, or just busy with something else. `Portability alert': On Unix, ‘select’ works both with the sockets and files. Don’t try this on Windows. On Windows, ‘select’ works with sockets only. Also note that in C, many of the more advanced socket options are done differently on Windows. In fact, on Windows I usually use threads (which work very, very well) with my sockets.  File: python.info, Node: Sorting HOW TO, Next: Unicode HOWTO, Prev: Socket Programming HOWTO, Up: Python HOWTOs 10.10 Sorting HOW TO ==================== Author: Andrew Dalke and Raymond Hettinger Release: 0.1 Python lists have a built-in *note list.sort(): 445. method that modifies the list in-place. There is also a *note sorted(): 444. built-in function that builds a new sorted list from an iterable. In this document, we explore the various techniques for sorting data using Python. * Menu: * Sorting Basics:: * Key Functions:: * Operator Module Functions:: * Ascending and Descending:: * Sort Stability and Complex Sorts:: * The Old Way Using Decorate-Sort-Undecorate:: * The Old Way Using the cmp Parameter:: * Odd and Ends::  File: python.info, Node: Sorting Basics, Next: Key Functions, Up: Sorting HOW TO 10.10.1 Sorting Basics ---------------------- A simple ascending sort is very easy: just call the *note sorted(): 444. function. It returns a new sorted list: >>> sorted([5, 2, 3, 1, 4]) [1, 2, 3, 4, 5] You can also use the *note list.sort(): 445. method. It modifies the list in-place (and returns ‘None’ to avoid confusion). Usually it’s less convenient than *note sorted(): 444. - but if you don’t need the original list, it’s slightly more efficient. >>> a = [5, 2, 3, 1, 4] >>> a.sort() >>> a [1, 2, 3, 4, 5] Another difference is that the *note list.sort(): 445. method is only defined for lists. In contrast, the *note sorted(): 444. function accepts any iterable. >>> sorted({1: 'D', 2: 'B', 3: 'B', 4: 'E', 5: 'A'}) [1, 2, 3, 4, 5]  File: python.info, Node: Key Functions, Next: Operator Module Functions, Prev: Sorting Basics, Up: Sorting HOW TO 10.10.2 Key Functions --------------------- Both *note list.sort(): 445. and *note sorted(): 444. have a `key' parameter to specify a function to be called on each list element prior to making comparisons. For example, here’s a case-insensitive string comparison: >>> sorted("This is a test string from Andrew".split(), key=str.lower) ['a', 'Andrew', 'from', 'is', 'string', 'test', 'This'] The value of the `key' parameter should be a function that takes a single argument and returns a key to use for sorting purposes. This technique is fast because the key function is called exactly once for each input record. A common pattern is to sort complex objects using some of the object’s indices as keys. For example: >>> student_tuples = [ ... ('john', 'A', 15), ... ('jane', 'B', 12), ... ('dave', 'B', 10), ... ] >>> sorted(student_tuples, key=lambda student: student[2]) # sort by age [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] The same technique works for objects with named attributes. For example: >>> class Student: ... def __init__(self, name, grade, age): ... self.name = name ... self.grade = grade ... self.age = age ... def __repr__(self): ... return repr((self.name, self.grade, self.age)) >>> student_objects = [ ... Student('john', 'A', 15), ... Student('jane', 'B', 12), ... Student('dave', 'B', 10), ... ] >>> sorted(student_objects, key=lambda student: student.age) # sort by age [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]  File: python.info, Node: Operator Module Functions, Next: Ascending and Descending, Prev: Key Functions, Up: Sorting HOW TO 10.10.3 Operator Module Functions --------------------------------- The key-function patterns shown above are very common, so Python provides convenience functions to make accessor functions easier and faster. The *note operator: c2. module has *note itemgetter(): 261, *note attrgetter(): 71b, and a *note methodcaller(): 71c. function. Using those functions, the above examples become simpler and faster: >>> from operator import itemgetter, attrgetter >>> sorted(student_tuples, key=itemgetter(2)) [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] >>> sorted(student_objects, key=attrgetter('age')) [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] The operator module functions allow multiple levels of sorting. For example, to sort by `grade' then by `age': >>> sorted(student_tuples, key=itemgetter(1,2)) [('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)] >>> sorted(student_objects, key=attrgetter('grade', 'age')) [('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]  File: python.info, Node: Ascending and Descending, Next: Sort Stability and Complex Sorts, Prev: Operator Module Functions, Up: Sorting HOW TO 10.10.4 Ascending and Descending -------------------------------- Both *note list.sort(): 445. and *note sorted(): 444. accept a `reverse' parameter with a boolean value. This is used to flag descending sorts. For example, to get the student data in reverse `age' order: >>> sorted(student_tuples, key=itemgetter(2), reverse=True) [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)] >>> sorted(student_objects, key=attrgetter('age'), reverse=True) [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]  File: python.info, Node: Sort Stability and Complex Sorts, Next: The Old Way Using Decorate-Sort-Undecorate, Prev: Ascending and Descending, Up: Sorting HOW TO 10.10.5 Sort Stability and Complex Sorts ---------------------------------------- Sorts are guaranteed to be stable(1). That means that when multiple records have the same key, their original order is preserved. >>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)] >>> sorted(data, key=itemgetter(0)) [('blue', 1), ('blue', 2), ('red', 1), ('red', 2)] Notice how the two records for `blue' retain their original order so that ‘('blue', 1)’ is guaranteed to precede ‘('blue', 2)’. This wonderful property lets you build complex sorts in a series of sorting steps. For example, to sort the student data by descending `grade' and then ascending `age', do the `age' sort first and then sort again using `grade': >>> s = sorted(student_objects, key=attrgetter('age')) # sort on secondary key >>> sorted(s, key=attrgetter('grade'), reverse=True) # now sort on primary key, descending [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] This can be abstracted out into a wrapper function that can take a list and tuples of field and order to sort them on multiple passes. >>> def multisort(xs, specs): ... for key, reverse in reversed(specs): ... xs.sort(key=attrgetter(key), reverse=reverse) ... return xs >>> multisort(list(student_objects), (('grade', True), ('age', False))) [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] The Timsort(2) algorithm used in Python does multiple sorts efficiently because it can take advantage of any ordering already present in a dataset. ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Sorting_algorithm#Stability (2) https://en.wikipedia.org/wiki/Timsort  File: python.info, Node: The Old Way Using Decorate-Sort-Undecorate, Next: The Old Way Using the cmp Parameter, Prev: Sort Stability and Complex Sorts, Up: Sorting HOW TO 10.10.6 The Old Way Using Decorate-Sort-Undecorate -------------------------------------------------- This idiom is called Decorate-Sort-Undecorate after its three steps: * First, the initial list is decorated with new values that control the sort order. * Second, the decorated list is sorted. * Finally, the decorations are removed, creating a list that contains only the initial values in the new order. For example, to sort the student data by `grade' using the DSU approach: >>> decorated = [(student.grade, i, student) for i, student in enumerate(student_objects)] >>> decorated.sort() >>> [student for grade, i, student in decorated] # undecorate [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)] This idiom works because tuples are compared lexicographically; the first items are compared; if they are the same then the second items are compared, and so on. It is not strictly necessary in all cases to include the index `i' in the decorated list, but including it gives two benefits: * The sort is stable – if two items have the same key, their order will be preserved in the sorted list. * The original items do not have to be comparable because the ordering of the decorated tuples will be determined by at most the first two items. So for example the original list could contain complex numbers which cannot be sorted directly. Another name for this idiom is Schwartzian transform(1), after Randal L. Schwartz, who popularized it among Perl programmers. Now that Python sorting provides key-functions, this technique is not often needed. ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Schwartzian_transform  File: python.info, Node: The Old Way Using the cmp Parameter, Next: Odd and Ends, Prev: The Old Way Using Decorate-Sort-Undecorate, Up: Sorting HOW TO 10.10.7 The Old Way Using the `cmp' Parameter --------------------------------------------- Many constructs given in this HOWTO assume Python 2.4 or later. Before that, there was no *note sorted(): 444. builtin and *note list.sort(): 445. took no keyword arguments. Instead, all of the Py2.x versions supported a `cmp' parameter to handle user specified comparison functions. In Py3.0, the `cmp' parameter was removed entirely (as part of a larger effort to simplify and unify the language, eliminating the conflict between rich comparisons and the ‘__cmp__()’ magic method). In Py2.x, sort allowed an optional function which can be called for doing the comparisons. That function should take two arguments to be compared and then return a negative value for less-than, return zero if they are equal, or return a positive value for greater-than. For example, we can do: >>> def numeric_compare(x, y): ... return x - y >>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare) [1, 2, 3, 4, 5] Or you can reverse the order of comparison with: >>> def reverse_numeric(x, y): ... return y - x >>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric) [5, 4, 3, 2, 1] When porting code from Python 2.x to 3.x, the situation can arise when you have the user supplying a comparison function and you need to convert that to a key function. The following wrapper makes that easy to do: def cmp_to_key(mycmp): 'Convert a cmp= function into a key= function' class K: def __init__(self, obj, *args): self.obj = obj def __lt__(self, other): return mycmp(self.obj, other.obj) < 0 def __gt__(self, other): return mycmp(self.obj, other.obj) > 0 def __eq__(self, other): return mycmp(self.obj, other.obj) == 0 def __le__(self, other): return mycmp(self.obj, other.obj) <= 0 def __ge__(self, other): return mycmp(self.obj, other.obj) >= 0 def __ne__(self, other): return mycmp(self.obj, other.obj) != 0 return K To convert to a key function, just wrap the old comparison function: >>> sorted([5, 2, 4, 1, 3], key=cmp_to_key(reverse_numeric)) [5, 4, 3, 2, 1] In Python 3.2, the *note functools.cmp_to_key(): b56. function was added to the *note functools: 85. module in the standard library.  File: python.info, Node: Odd and Ends, Prev: The Old Way Using the cmp Parameter, Up: Sorting HOW TO 10.10.8 Odd and Ends -------------------- * For locale aware sorting, use *note locale.strxfrm(): 2d93. for a key function or *note locale.strcoll(): 2d91. for a comparison function. * The `reverse' parameter still maintains sort stability (so that records with equal keys retain the original order). Interestingly, that effect can be simulated without the parameter by using the builtin *note reversed(): 18e. function twice: >>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)] >>> standard_way = sorted(data, key=itemgetter(0), reverse=True) >>> double_reversed = list(reversed(sorted(reversed(data), key=itemgetter(0)))) >>> assert standard_way == double_reversed >>> standard_way [('red', 1), ('red', 2), ('blue', 1), ('blue', 2)] * The sort routines are guaranteed to use *note __lt__(): c34. when making comparisons between two objects. So, it is easy to add a standard sort order to a class by defining an *note __lt__(): c34. method: >>> Student.__lt__ = lambda self, other: self.age < other.age >>> sorted(student_objects) [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] * Key functions need not depend directly on the objects being sorted. A key function can also access external resources. For instance, if the student grades are stored in a dictionary, they can be used to sort a separate list of student names: >>> students = ['dave', 'john', 'jane'] >>> newgrades = {'john': 'F', 'jane':'A', 'dave': 'C'} >>> sorted(students, key=newgrades.__getitem__) ['jane', 'dave', 'john']  File: python.info, Node: Unicode HOWTO, Next: HOWTO Fetch Internet Resources Using The urllib Package, Prev: Sorting HOW TO, Up: Python HOWTOs 10.11 Unicode HOWTO =================== Release: 1.12 This HOWTO discusses Python’s support for the Unicode specification for representing textual data, and explains various problems that people commonly encounter when trying to work with Unicode. * Menu: * Introduction to Unicode:: * Python’s Unicode Support:: * Reading and Writing Unicode Data:: * Acknowledgements: Acknowledgements<10>.  File: python.info, Node: Introduction to Unicode, Next: Python’s Unicode Support, Up: Unicode HOWTO 10.11.1 Introduction to Unicode ------------------------------- * Menu: * Definitions:: * Encodings:: * References: References<3>.  File: python.info, Node: Definitions, Next: Encodings, Up: Introduction to Unicode 10.11.1.1 Definitions ..................... Today’s programs need to be able to handle a wide variety of characters. Applications are often internationalized to display messages and output in a variety of user-selectable languages; the same program might need to output an error message in English, French, Japanese, Hebrew, or Russian. Web content can be written in any of these languages and can also include a variety of emoji symbols. Python’s string type uses the Unicode Standard for representing characters, which lets Python programs work with all these different possible characters. Unicode (‘https://www.unicode.org/’) is a specification that aims to list every character used by human languages and give each character its own unique code. The Unicode specifications are continually revised and updated to add new languages and symbols. A `character' is the smallest possible component of a text. ‘A’, ‘B’, ‘C’, etc., are all different characters. So are ‘È’ and ‘Í’. Characters vary depending on the language or context you’re talking about. For example, there’s a character for “Roman Numeral One”, ‘Ⅰ’, that’s separate from the uppercase letter ‘I’. They’ll usually look the same, but these are two different characters that have different meanings. The Unicode standard describes how characters are represented by `code points'. A code point value is an integer in the range 0 to 0x10FFFF (about 1.1 million values, with some 110 thousand assigned so far). In the standard and in this document, a code point is written using the notation ‘U+265E’ to mean the character with value ‘0x265e’ (9,822 in decimal). The Unicode standard contains a lot of tables listing characters and their corresponding code points: 0061 'a'; LATIN SMALL LETTER A 0062 'b'; LATIN SMALL LETTER B 0063 'c'; LATIN SMALL LETTER C ... 007B '{'; LEFT CURLY BRACKET ... 2167 'Ⅷ'; ROMAN NUMERAL EIGHT 2168 'Ⅸ'; ROMAN NUMERAL NINE ... 265E '♞'; BLACK CHESS KNIGHT 265F '♟'; BLACK CHESS PAWN ... 1F600 '😀'; GRINNING FACE 1F609 '😉'; WINKING FACE ... Strictly, these definitions imply that it’s meaningless to say ‘this is character ‘U+265E’’. ‘U+265E’ is a code point, which represents some particular character; in this case, it represents the character ‘BLACK CHESS KNIGHT’, ‘♞’. In informal contexts, this distinction between code points and characters will sometimes be forgotten. A character is represented on a screen or on paper by a set of graphical elements that’s called a `glyph'. The glyph for an uppercase A, for example, is two diagonal strokes and a horizontal stroke, though the exact details will depend on the font being used. Most Python code doesn’t need to worry about glyphs; figuring out the correct glyph to display is generally the job of a GUI toolkit or a terminal’s font renderer.  File: python.info, Node: Encodings, Next: References<3>, Prev: Definitions, Up: Introduction to Unicode 10.11.1.2 Encodings ................... To summarize the previous section: a Unicode string is a sequence of code points, which are numbers from 0 through ‘0x10FFFF’ (1,114,111 decimal). This sequence of code points needs to be represented in memory as a set of `code units', and `code units' are then mapped to 8-bit bytes. The rules for translating a Unicode string into a sequence of bytes are called a `character encoding', or just an `encoding'. The first encoding you might think of is using 32-bit integers as the code unit, and then using the CPU’s representation of 32-bit integers. In this representation, the string “Python” might look like this: P y t h o n 0x50 00 00 00 79 00 00 00 74 00 00 00 68 00 00 00 6f 00 00 00 6e 00 00 00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 This representation is straightforward but using it presents a number of problems. 1. It’s not portable; different processors order the bytes differently. 2. It’s very wasteful of space. In most texts, the majority of the code points are less than 127, or less than 255, so a lot of space is occupied by ‘0x00’ bytes. The above string takes 24 bytes compared to the 6 bytes needed for an ASCII representation. Increased RAM usage doesn’t matter too much (desktop computers have gigabytes of RAM, and strings aren’t usually that large), but expanding our usage of disk and network bandwidth by a factor of 4 is intolerable. 3. It’s not compatible with existing C functions such as ‘strlen()’, so a new family of wide string functions would need to be used. Therefore this encoding isn’t used very much, and people instead choose other encodings that are more efficient and convenient, such as UTF-8. UTF-8 is one of the most commonly used encodings, and Python often defaults to using it. UTF stands for “Unicode Transformation Format”, and the ‘8’ means that 8-bit values are used in the encoding. (There are also UTF-16 and UTF-32 encodings, but they are less frequently used than UTF-8.) UTF-8 uses the following rules: 1. If the code point is < 128, it’s represented by the corresponding byte value. 2. If the code point is >= 128, it’s turned into a sequence of two, three, or four bytes, where each byte of the sequence is between 128 and 255. UTF-8 has several convenient properties: 1. It can handle any Unicode code point. 2. A Unicode string is turned into a sequence of bytes that contains embedded zero bytes only where they represent the null character (U+0000). This means that UTF-8 strings can be processed by C functions such as ‘strcpy()’ and sent through protocols that can’t handle zero bytes for anything other than end-of-string markers. 3. A string of ASCII text is also valid UTF-8 text. 4. UTF-8 is fairly compact; the majority of commonly used characters can be represented with one or two bytes. 5. If bytes are corrupted or lost, it’s possible to determine the start of the next UTF-8-encoded code point and resynchronize. It’s also unlikely that random 8-bit data will look like valid UTF-8. 6. UTF-8 is a byte oriented encoding. The encoding specifies that each character is represented by a specific sequence of one or more bytes. This avoids the byte-ordering issues that can occur with integer and word oriented encodings, like UTF-16 and UTF-32, where the sequence of bytes varies depending on the hardware on which the string was encoded.  File: python.info, Node: References<3>, Prev: Encodings, Up: Introduction to Unicode 10.11.1.3 References .................... The Unicode Consortium site(1) has character charts, a glossary, and PDF versions of the Unicode specification. Be prepared for some difficult reading. A chronology(2) of the origin and development of Unicode is also available on the site. On the Computerphile Youtube channel, Tom Scott briefly discusses the history of Unicode and UTF-8(3) (9 minutes 36 seconds). To help understand the standard, Jukka Korpela has written an introductory guide(4) to reading the Unicode character tables. Another good introductory article(5) was written by Joel Spolsky. If this introduction didn’t make things clear to you, you should try reading this alternate article before continuing. Wikipedia entries are often helpful; see the entries for “character encoding(6)” and UTF-8(7), for example. ---------- Footnotes ---------- (1) http://www.unicode.org (2) http://www.unicode.org/history/ (3) https://www.youtube.com/watch?v=MijmeoH9LT4 (4) http://jkorpela.fi/unicode/guide.html (5) https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/ (6) https://en.wikipedia.org/wiki/Character_encoding (7) https://en.wikipedia.org/wiki/UTF-8  File: python.info, Node: Python’s Unicode Support, Next: Reading and Writing Unicode Data, Prev: Introduction to Unicode, Up: Unicode HOWTO 10.11.2 Python’s Unicode Support -------------------------------- Now that you’ve learned the rudiments of Unicode, we can look at Python’s Unicode features. * Menu: * The String Type:: * Converting to Bytes:: * Unicode Literals in Python Source Code:: * Unicode Properties:: * Comparing Strings:: * Unicode Regular Expressions:: * References: References<4>.  File: python.info, Node: The String Type, Next: Converting to Bytes, Up: Python’s Unicode Support 10.11.2.1 The String Type ......................... Since Python 3.0, the language’s *note str: 330. type contains Unicode characters, meaning any string created using ‘"unicode rocks!"’, ‘'unicode rocks!'’, or the triple-quoted string syntax is stored as Unicode. The default encoding for Python source code is UTF-8, so you can simply include a Unicode character in a string literal: try: with open('/tmp/input.txt', 'r') as f: ... except OSError: # 'File not found' error message. print("Fichier non trouvé") Side note: Python 3 also supports using Unicode characters in identifiers: répertoire = "/tmp/records.log" with open(répertoire, "w") as f: f.write("test\n") If you can’t enter a particular character in your editor or want to keep the source code ASCII-only for some reason, you can also use escape sequences in string literals. (Depending on your system, you may see the actual capital-delta glyph instead of a u escape.) >>> "\N{GREEK CAPITAL LETTER DELTA}" # Using the character name '\u0394' >>> "\u0394" # Using a 16-bit hex value '\u0394' >>> "\U00000394" # Using a 32-bit hex value '\u0394' In addition, one can create a string using the *note decode(): c38. method of *note bytes: 331. This method takes an `encoding' argument, such as ‘UTF-8’, and optionally an `errors' argument. The `errors' argument specifies the response when the input string can’t be converted according to the encoding’s rules. Legal values for this argument are ‘'strict'’ (raise a *note UnicodeDecodeError: 1fd. exception), ‘'replace'’ (use ‘U+FFFD’, ‘REPLACEMENT CHARACTER’), ‘'ignore'’ (just leave the character out of the Unicode result), or ‘'backslashreplace'’ (inserts a ‘\xNN’ escape sequence). The following examples show the differences: >>> b'\x80abc'.decode("utf-8", "strict") Traceback (most recent call last): ... UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position 0: invalid start byte >>> b'\x80abc'.decode("utf-8", "replace") '\ufffdabc' >>> b'\x80abc'.decode("utf-8", "backslashreplace") '\\x80abc' >>> b'\x80abc'.decode("utf-8", "ignore") 'abc' Encodings are specified as strings containing the encoding’s name. Python comes with roughly 100 different encodings; see the Python Library Reference at *note Standard Encodings: 68f. for a list. Some encodings have multiple names; for example, ‘'latin-1'’, ‘'iso_8859_1'’ and ‘'8859’’ are all synonyms for the same encoding. One-character Unicode strings can also be created with the *note chr(): 10c7. built-in function, which takes integers and returns a Unicode string of length 1 that contains the corresponding code point. The reverse operation is the built-in *note ord(): 10c6. function that takes a one-character Unicode string and returns the code point value: >>> chr(57344) '\ue000' >>> ord('\ue000') 57344  File: python.info, Node: Converting to Bytes, Next: Unicode Literals in Python Source Code, Prev: The String Type, Up: Python’s Unicode Support 10.11.2.2 Converting to Bytes ............................. The opposite method of *note bytes.decode(): c38. is *note str.encode(): c37, which returns a *note bytes: 331. representation of the Unicode string, encoded in the requested `encoding'. The `errors' parameter is the same as the parameter of the *note decode(): c38. method but supports a few more possible handlers. As well as ‘'strict'’, ‘'ignore'’, and ‘'replace'’ (which in this case inserts a question mark instead of the unencodable character), there is also ‘'xmlcharrefreplace'’ (inserts an XML character reference), ‘backslashreplace’ (inserts a ‘\uNNNN’ escape sequence) and ‘namereplace’ (inserts a ‘\N{...}’ escape sequence). The following example shows the different results: >>> u = chr(40960) + 'abcd' + chr(1972) >>> u.encode('utf-8') b'\xea\x80\x80abcd\xde\xb4' >>> u.encode('ascii') Traceback (most recent call last): ... UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in position 0: ordinal not in range(128) >>> u.encode('ascii', 'ignore') b'abcd' >>> u.encode('ascii', 'replace') b'?abcd?' >>> u.encode('ascii', 'xmlcharrefreplace') b'ꀀabcd޴' >>> u.encode('ascii', 'backslashreplace') b'\\ua000abcd\\u07b4' >>> u.encode('ascii', 'namereplace') b'\\N{YI SYLLABLE IT}abcd\\u07b4' The low-level routines for registering and accessing the available encodings are found in the *note codecs: 1c. module. Implementing new encodings also requires understanding the *note codecs: 1c. module. However, the encoding and decoding functions returned by this module are usually more low-level than is comfortable, and writing new encodings is a specialized task, so the module won’t be covered in this HOWTO.  File: python.info, Node: Unicode Literals in Python Source Code, Next: Unicode Properties, Prev: Converting to Bytes, Up: Python’s Unicode Support 10.11.2.3 Unicode Literals in Python Source Code ................................................ In Python source code, specific Unicode code points can be written using the ‘\u’ escape sequence, which is followed by four hex digits giving the code point. The ‘\U’ escape sequence is similar, but expects eight hex digits, not four: >>> s = "a\xac\u1234\u20ac\U00008000" ... # ^^^^ two-digit hex escape ... # ^^^^^^ four-digit Unicode escape ... # ^^^^^^^^^^ eight-digit Unicode escape >>> [ord(c) for c in s] [97, 172, 4660, 8364, 32768] Using escape sequences for code points greater than 127 is fine in small doses, but becomes an annoyance if you’re using many accented characters, as you would in a program with messages in French or some other accent-using language. You can also assemble strings using the *note chr(): 10c7. built-in function, but this is even more tedious. Ideally, you’d want to be able to write literals in your language’s natural encoding. You could then edit Python source code with your favorite editor which would display the accented characters naturally, and have the right characters used at runtime. Python supports writing source code in UTF-8 by default, but you can use almost any encoding if you declare the encoding being used. This is done by including a special comment as either the first or second line of the source file: #!/usr/bin/env python # -*- coding: latin-1 -*- u = 'abcdé' print(ord(u[-1])) The syntax is inspired by Emacs’s notation for specifying variables local to a file. Emacs supports many different variables, but Python only supports ‘coding’. The ‘-*-’ symbols indicate to Emacs that the comment is special; they have no significance to Python but are a convention. Python looks for ‘coding: name’ or ‘coding=name’ in the comment. If you don’t include such a comment, the default encoding used will be UTF-8 as already mentioned. See also PEP 263(1) for more information. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0263  File: python.info, Node: Unicode Properties, Next: Comparing Strings, Prev: Unicode Literals in Python Source Code, Up: Python’s Unicode Support 10.11.2.4 Unicode Properties ............................ The Unicode specification includes a database of information about code points. For each defined code point, the information includes the character’s name, its category, the numeric value if applicable (for characters representing numeric concepts such as the Roman numerals, fractions such as one-third and four-fifths, etc.). There are also display-related properties, such as how to use the code point in bidirectional text. The following program displays some information about several characters, and prints the numeric value of one particular character: import unicodedata u = chr(233) + chr(0x0bf2) + chr(3972) + chr(6000) + chr(13231) for i, c in enumerate(u): print(i, '%04x' % ord(c), unicodedata.category(c), end=" ") print(unicodedata.name(c)) # Get numeric value of second character print(unicodedata.numeric(u[1])) When run, this prints: 0 00e9 Ll LATIN SMALL LETTER E WITH ACUTE 1 0bf2 No TAMIL NUMBER ONE THOUSAND 2 0f84 Mn TIBETAN MARK HALANTA 3 1770 Lo TAGBANWA LETTER SA 4 33af So SQUARE RAD OVER S SQUARED 1000.0 The category codes are abbreviations describing the nature of the character. These are grouped into categories such as “Letter”, “Number”, “Punctuation”, or “Symbol”, which in turn are broken up into subcategories. To take the codes from the above output, ‘'Ll'’ means ‘Letter, lowercase’, ‘'No'’ means “Number, other”, ‘'Mn'’ is “Mark, nonspacing”, and ‘'So'’ is “Symbol, other”. See the General Category Values section of the Unicode Character Database documentation(1) for a list of category codes. ---------- Footnotes ---------- (1) http://www.unicode.org/reports/tr44/#General_Category_Values  File: python.info, Node: Comparing Strings, Next: Unicode Regular Expressions, Prev: Unicode Properties, Up: Python’s Unicode Support 10.11.2.5 Comparing Strings ........................... Unicode adds some complication to comparing strings, because the same set of characters can be represented by different sequences of code points. For example, a letter like ‘ê’ can be represented as a single code point U+00EA, or as U+0065 U+0302, which is the code point for ‘e’ followed by a code point for ‘COMBINING CIRCUMFLEX ACCENT’. These will produce the same output when printed, but one is a string of length 1 and the other is of length 2. One tool for a case-insensitive comparison is the *note casefold(): 6b0. string method that converts a string to a case-insensitive form following an algorithm described by the Unicode Standard. This algorithm has special handling for characters such as the German letter ‘ß’ (code point U+00DF), which becomes the pair of lowercase letters ‘ss’. >>> street = 'Gürzenichstraße' >>> street.casefold() 'gürzenichstrasse' A second tool is the *note unicodedata: 11a. module’s *note normalize(): 11ed. function that converts strings to one of several normal forms, where letters followed by a combining character are replaced with single characters. ‘normalize()’ can be used to perform string comparisons that won’t falsely report inequality if two strings use combining characters differently: import unicodedata def compare_strs(s1, s2): def NFD(s): return unicodedata.normalize('NFD', s) return NFD(s1) == NFD(s2) single_char = 'ê' multiple_chars = '\N{LATIN SMALL LETTER E}\N{COMBINING CIRCUMFLEX ACCENT}' print('length of first string=', len(single_char)) print('length of second string=', len(multiple_chars)) print(compare_strs(single_char, multiple_chars)) When run, this outputs: $ python3 compare-strs.py length of first string= 1 length of second string= 2 True The first argument to the *note normalize(): 11ed. function is a string giving the desired normalization form, which can be one of ‘NFC’, ‘NFKC’, ‘NFD’, and ‘NFKD’. The Unicode Standard also specifies how to do caseless comparisons: import unicodedata def compare_caseless(s1, s2): def NFD(s): return unicodedata.normalize('NFD', s) return NFD(NFD(s1).casefold()) == NFD(NFD(s2).casefold()) # Example usage single_char = 'ê' multiple_chars = '\N{LATIN CAPITAL LETTER E}\N{COMBINING CIRCUMFLEX ACCENT}' print(compare_caseless(single_char, multiple_chars)) This will print ‘True’. (Why is ‘NFD()’ invoked twice? Because there are a few characters that make ‘casefold()’ return a non-normalized string, so the result needs to be normalized again. See section 3.13 of the Unicode Standard for a discussion and an example.)  File: python.info, Node: Unicode Regular Expressions, Next: References<4>, Prev: Comparing Strings, Up: Python’s Unicode Support 10.11.2.6 Unicode Regular Expressions ..................................... The regular expressions supported by the *note re: dd. module can be provided either as bytes or strings. Some of the special character sequences such as ‘\d’ and ‘\w’ have different meanings depending on whether the pattern is supplied as bytes or a string. For example, ‘\d’ will match the characters ‘[0-9]’ in bytes but in strings will match any character that’s in the ‘'Nd'’ category. The string in this example has the number 57 written in both Thai and Arabic numerals: import re p = re.compile(r'\d+') s = "Over \u0e55\u0e57 57 flavours" m = p.search(s) print(repr(m.group())) When executed, ‘\d+’ will match the Thai numerals and print them out. If you supply the *note re.ASCII: 3c8. flag to *note compile(): 44a, ‘\d+’ will match the substring “57” instead. Similarly, ‘\w’ matches a wide variety of Unicode characters but only ‘[a-zA-Z0-9_]’ in bytes or if *note re.ASCII: 3c8. is supplied, and ‘\s’ will match either Unicode whitespace characters or ‘[ \t\n\r\f\v]’.  File: python.info, Node: References<4>, Prev: Unicode Regular Expressions, Up: Python’s Unicode Support 10.11.2.7 References .................... Some good alternative discussions of Python’s Unicode support are: * Processing Text Files in Python 3(1), by Nick Coghlan. * Pragmatic Unicode(2), a PyCon 2012 presentation by Ned Batchelder. The *note str: 330. type is described in the Python library reference at *note Text Sequence Type — str: eb7. The documentation for the *note unicodedata: 11a. module. The documentation for the *note codecs: 1c. module. Marc-André Lemburg gave a presentation titled "Python and Unicode" (PDF slides)(3) at EuroPython 2002. The slides are an excellent overview of the design of Python 2’s Unicode features (where the Unicode string type is called ‘unicode’ and literals start with ‘u’). ---------- Footnotes ---------- (1) http://python-notes.curiousefficiency.org/en/latest/python3/text_file_processing.html (2) https://nedbatchelder.com/text/unipain.html (3) https://downloads.egenix.com/python/Unicode-EPC2002-Talk.pdf  File: python.info, Node: Reading and Writing Unicode Data, Next: Acknowledgements<10>, Prev: Python’s Unicode Support, Up: Unicode HOWTO 10.11.3 Reading and Writing Unicode Data ---------------------------------------- Once you’ve written some code that works with Unicode data, the next problem is input/output. How do you get Unicode strings into your program, and how do you convert Unicode into a form suitable for storage or transmission? It’s possible that you may not need to do anything depending on your input sources and output destinations; you should check whether the libraries used in your application support Unicode natively. XML parsers often return Unicode data, for example. Many relational databases also support Unicode-valued columns and can return Unicode values from an SQL query. Unicode data is usually converted to a particular encoding before it gets written to disk or sent over a socket. It’s possible to do all the work yourself: open a file, read an 8-bit bytes object from it, and convert the bytes with ‘bytes.decode(encoding)’. However, the manual approach is not recommended. One problem is the multi-byte nature of encodings; one Unicode character can be represented by several bytes. If you want to read the file in arbitrary-sized chunks (say, 1024 or 4096 bytes), you need to write error-handling code to catch the case where only part of the bytes encoding a single Unicode character are read at the end of a chunk. One solution would be to read the entire file into memory and then perform the decoding, but that prevents you from working with files that are extremely large; if you need to read a 2 GiB file, you need 2 GiB of RAM. (More, really, since for at least a moment you’d need to have both the encoded string and its Unicode version in memory.) The solution would be to use the low-level decoding interface to catch the case of partial coding sequences. The work of implementing this has already been done for you: the built-in *note open(): 4f0. function can return a file-like object that assumes the file’s contents are in a specified encoding and accepts Unicode parameters for methods such as *note read(): 1ce1. and *note write(): 1ce4. This works through *note open(): 4f0.’s `encoding' and `errors' parameters which are interpreted just like those in *note str.encode(): c37. and *note bytes.decode(): c38. Reading Unicode from a file is therefore simple: with open('unicode.txt', encoding='utf-8') as f: for line in f: print(repr(line)) It’s also possible to open files in update mode, allowing both reading and writing: with open('test', encoding='utf-8', mode='w+') as f: f.write('\u4500 blah blah blah\n') f.seek(0) print(repr(f.readline()[:1])) The Unicode character ‘U+FEFF’ is used as a byte-order mark (BOM), and is often written as the first character of a file in order to assist with autodetection of the file’s byte ordering. Some encodings, such as UTF-16, expect a BOM to be present at the start of a file; when such an encoding is used, the BOM will be automatically written as the first character and will be silently dropped when the file is read. There are variants of these encodings, such as ‘utf-16-le’ and ‘utf-16-be’ for little-endian and big-endian encodings, that specify one particular byte ordering and don’t skip the BOM. In some areas, it is also convention to use a “BOM” at the start of UTF-8 encoded files; the name is misleading since UTF-8 is not byte-order dependent. The mark simply announces that the file is encoded in UTF-8. For reading such files, use the ‘utf-8-sig’ codec to automatically skip the mark if present. * Menu: * Unicode filenames:: * Tips for Writing Unicode-aware Programs:: * References: References<5>.  File: python.info, Node: Unicode filenames, Next: Tips for Writing Unicode-aware Programs, Up: Reading and Writing Unicode Data 10.11.3.1 Unicode filenames ........................... Most of the operating systems in common use today support filenames that contain arbitrary Unicode characters. Usually this is implemented by converting the Unicode string into some encoding that varies depending on the system. Today Python is converging on using UTF-8: Python on MacOS has used UTF-8 for several versions, and Python 3.6 switched to using UTF-8 on Windows as well. On Unix systems, there will only be a filesystem encoding if you’ve set the ‘LANG’ or ‘LC_CTYPE’ environment variables; if you haven’t, the default encoding is again UTF-8. The *note sys.getfilesystemencoding(): 4f6. function returns the encoding to use on your current system, in case you want to do the encoding manually, but there’s not much reason to bother. When opening a file for reading or writing, you can usually just provide the Unicode string as the filename, and it will be automatically converted to the right encoding for you: filename = 'filename\u4500abc' with open(filename, 'w') as f: f.write('blah\n') Functions in the *note os: c4. module such as *note os.stat(): 1f1. will also accept Unicode filenames. The *note os.listdir(): a41. function returns filenames, which raises an issue: should it return the Unicode version of filenames, or should it return bytes containing the encoded versions? *note os.listdir(): a41. can do both, depending on whether you provided the directory path as bytes or a Unicode string. If you pass a Unicode string as the path, filenames will be decoded using the filesystem’s encoding and a list of Unicode strings will be returned, while passing a byte path will return the filenames as bytes. For example, assuming the default filesystem encoding is UTF-8, running the following program: fn = 'filename\u4500abc' f = open(fn, 'w') f.close() import os print(os.listdir(b'.')) print(os.listdir('.')) will produce the following output: $ python listdir-test.py [b'filename\xe4\x94\x80abc', ...] ['filename\u4500abc', ...] The first list contains UTF-8-encoded filenames, and the second list contains the Unicode versions. Note that on most occasions, you should can just stick with using Unicode with these APIs. The bytes APIs should only be used on systems where undecodable file names can be present; that’s pretty much only Unix systems now.  File: python.info, Node: Tips for Writing Unicode-aware Programs, Next: References<5>, Prev: Unicode filenames, Up: Reading and Writing Unicode Data 10.11.3.2 Tips for Writing Unicode-aware Programs ................................................. This section provides some suggestions on writing software that deals with Unicode. The most important tip is: Software should only work with Unicode strings internally, decoding the input data as soon as possible and encoding the output only at the end. If you attempt to write processing functions that accept both Unicode and byte strings, you will find your program vulnerable to bugs wherever you combine the two different kinds of strings. There is no automatic encoding or decoding: if you do e.g. ‘str + bytes’, a *note TypeError: 192. will be raised. When using data coming from a web browser or some other untrusted source, a common technique is to check for illegal characters in a string before using the string in a generated command line or storing it in a database. If you’re doing this, be careful to check the decoded string, not the encoded bytes data; some encodings may have interesting properties, such as not being bijective or not being fully ASCII-compatible. This is especially true if the input data also specifies the encoding, since the attacker can then choose a clever way to hide malicious text in the encoded bytestream. * Menu: * Converting Between File Encodings:: * Files in an Unknown Encoding::  File: python.info, Node: Converting Between File Encodings, Next: Files in an Unknown Encoding, Up: Tips for Writing Unicode-aware Programs 10.11.3.3 Converting Between File Encodings ........................................... The *note StreamRecoder: 14e3. class can transparently convert between encodings, taking a stream that returns data in encoding #1 and behaving like a stream returning data in encoding #2. For example, if you have an input file `f' that’s in Latin-1, you can wrap it with a *note StreamRecoder: 14e3. to return bytes encoded in UTF-8: new_f = codecs.StreamRecoder(f, # en/decoder: used by read() to encode its results and # by write() to decode its input. codecs.getencoder('utf-8'), codecs.getdecoder('utf-8'), # reader/writer: used to read and write to the stream. codecs.getreader('latin-1'), codecs.getwriter('latin-1') )  File: python.info, Node: Files in an Unknown Encoding, Prev: Converting Between File Encodings, Up: Tips for Writing Unicode-aware Programs 10.11.3.4 Files in an Unknown Encoding ...................................... What can you do if you need to make a change to a file, but don’t know the file’s encoding? If you know the encoding is ASCII-compatible and only want to examine or modify the ASCII parts, you can open the file with the ‘surrogateescape’ error handler: with open(fname, 'r', encoding="ascii", errors="surrogateescape") as f: data = f.read() # make changes to the string 'data' with open(fname + '.new', 'w', encoding="ascii", errors="surrogateescape") as f: f.write(data) The ‘surrogateescape’ error handler will decode any non-ASCII bytes as code points in a special range running from U+DC80 to U+DCFF. These code points will then turn back into the same bytes when the ‘surrogateescape’ error handler is used to encode the data and write it back out.  File: python.info, Node: References<5>, Prev: Tips for Writing Unicode-aware Programs, Up: Reading and Writing Unicode Data 10.11.3.5 References .................... One section of Mastering Python 3 Input/Output(1), a PyCon 2010 talk by David Beazley, discusses text processing and binary data handling. The PDF slides for Marc-André Lemburg’s presentation "Writing Unicode-aware Applications in Python"(2) discuss questions of character encodings as well as how to internationalize and localize an application. These slides cover Python 2.x only. The Guts of Unicode in Python(3) is a PyCon 2013 talk by Benjamin Peterson that discusses the internal Unicode representation in Python 3.3. ---------- Footnotes ---------- (1) http://pyvideo.org/video/289/pycon-2010–mastering-python-3-i-o (2) https://downloads.egenix.com/python/LSM2005-Developing-Unicode-aware-applications-in-Python.pdf (3) http://pyvideo.org/video/1768/the-guts-of-unicode-in-python  File: python.info, Node: Acknowledgements<10>, Prev: Reading and Writing Unicode Data, Up: Unicode HOWTO 10.11.4 Acknowledgements ------------------------ The initial draft of this document was written by Andrew Kuchling. It has since been revised further by Alexander Belopolsky, Georg Brandl, Andrew Kuchling, and Ezio Melotti. Thanks to the following people who have noted errors or offered suggestions on this article: Éric Araujo, Nicholas Bastin, Nick Coghlan, Marius Gedminas, Kent Johnson, Ken Krugler, Marc-André Lemburg, Martin von Löwis, Terry J. Reedy, Serhiy Storchaka, Eryk Sun, Chad Whitacre, Graham Wideman.  File: python.info, Node: HOWTO Fetch Internet Resources Using The urllib Package, Next: Argparse Tutorial, Prev: Unicode HOWTO, Up: Python HOWTOs 10.12 HOWTO Fetch Internet Resources Using The urllib Package ============================================================= Author: Michael Foord(1) Note: There is a French translation of an earlier revision of this HOWTO, available at urllib2 - Le Manuel manquant(2). * Menu: * Introduction: Introduction<16>. * Fetching URLs:: * Handling Exceptions: Handling Exceptions<2>. * info and geturl:: * Openers and Handlers:: * Basic Authentication:: * Proxies:: * Sockets and Layers:: * Footnotes:: ---------- Footnotes ---------- (1) http://www.voidspace.org.uk/python/index.shtml (2) http://www.voidspace.org.uk/python/articles/urllib2_francais.shtml  File: python.info, Node: Introduction<16>, Next: Fetching URLs, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.1 Introduction -------------------- Related Articles ................ You may also find useful the following article on fetching web resources with Python: * Basic Authentication(1) A tutorial on `Basic Authentication', with examples in Python. `urllib.request' is a Python module for fetching URLs (Uniform Resource Locators). It offers a very simple interface, in the form of the `urlopen' function. This is capable of fetching URLs using a variety of different protocols. It also offers a slightly more complex interface for handling common situations - like basic authentication, cookies, proxies and so on. These are provided by objects called handlers and openers. urllib.request supports fetching URLs for many “URL schemes” (identified by the string before the ‘":"’ in URL - for example ‘"ftp"’ is the URL scheme of ‘"ftp://python.org/"’) using their associated network protocols (e.g. FTP, HTTP). This tutorial focuses on the most common case, HTTP. For straightforward situations `urlopen' is very easy to use. But as soon as you encounter errors or non-trivial cases when opening HTTP URLs, you will need some understanding of the HyperText Transfer Protocol. The most comprehensive and authoritative reference to HTTP is RFC 2616(2). This is a technical document and not intended to be easy to read. This HOWTO aims to illustrate using `urllib', with enough detail about HTTP to help you through. It is not intended to replace the *note urllib.request: 120. docs, but is supplementary to them. ---------- Footnotes ---------- (1) http://www.voidspace.org.uk/python/articles/authentication.shtml (2) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: Fetching URLs, Next: Handling Exceptions<2>, Prev: Introduction<16>, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.2 Fetching URLs --------------------- The simplest way to use urllib.request is as follows: import urllib.request with urllib.request.urlopen('http://python.org/') as response: html = response.read() If you wish to retrieve a resource via URL and store it in a temporary location, you can do so via the *note shutil.copyfileobj(): 25d. and *note tempfile.NamedTemporaryFile(): d49. functions: import shutil import tempfile import urllib.request with urllib.request.urlopen('http://python.org/') as response: with tempfile.NamedTemporaryFile(delete=False) as tmp_file: shutil.copyfileobj(response, tmp_file) with open(tmp_file.name) as html: pass Many uses of urllib will be that simple (note that instead of an ‘http:’ URL we could have used a URL starting with ‘ftp:’, ‘file:’, etc.). However, it’s the purpose of this tutorial to explain the more complicated cases, concentrating on HTTP. HTTP is based on requests and responses - the client makes requests and servers send responses. urllib.request mirrors this with a ‘Request’ object which represents the HTTP request you are making. In its simplest form you create a Request object that specifies the URL you want to fetch. Calling ‘urlopen’ with this Request object returns a response object for the URL requested. This response is a file-like object, which means you can for example call ‘.read()’ on the response: import urllib.request req = urllib.request.Request('http://www.voidspace.org.uk') with urllib.request.urlopen(req) as response: the_page = response.read() Note that urllib.request makes use of the same Request interface to handle all URL schemes. For example, you can make an FTP request like so: req = urllib.request.Request('ftp://example.com/') In the case of HTTP, there are two extra things that Request objects allow you to do: First, you can pass data to be sent to the server. Second, you can pass extra information (“metadata”) `about' the data or about the request itself, to the server - this information is sent as HTTP “headers”. Let’s look at each of these in turn. * Menu: * Data:: * Headers::  File: python.info, Node: Data, Next: Headers, Up: Fetching URLs 10.12.2.1 Data .............. Sometimes you want to send data to a URL (often the URL will refer to a CGI (Common Gateway Interface) script or other web application). With HTTP, this is often done using what’s known as a `POST' request. This is often what your browser does when you submit a HTML form that you filled in on the web. Not all POSTs have to come from forms: you can use a POST to transmit arbitrary data to your own application. In the common case of HTML forms, the data needs to be encoded in a standard way, and then passed to the Request object as the ‘data’ argument. The encoding is done using a function from the *note urllib.parse: 11f. library. import urllib.parse import urllib.request url = 'http://www.someserver.com/cgi-bin/register.cgi' values = {'name' : 'Michael Foord', 'location' : 'Northampton', 'language' : 'Python' } data = urllib.parse.urlencode(values) data = data.encode('ascii') # data should be bytes req = urllib.request.Request(url, data) with urllib.request.urlopen(req) as response: the_page = response.read() Note that other encodings are sometimes required (e.g. for file upload from HTML forms - see HTML Specification, Form Submission(1) for more details). If you do not pass the ‘data’ argument, urllib uses a `GET' request. One way in which GET and POST requests differ is that POST requests often have “side-effects”: they change the state of the system in some way (for example by placing an order with the website for a hundredweight of tinned spam to be delivered to your door). Though the HTTP standard makes it clear that POSTs are intended to `always' cause side-effects, and GET requests `never' to cause side-effects, nothing prevents a GET request from having side-effects, nor a POST requests from having no side-effects. Data can also be passed in an HTTP GET request by encoding it in the URL itself. This is done as follows: >>> import urllib.request >>> import urllib.parse >>> data = {} >>> data['name'] = 'Somebody Here' >>> data['location'] = 'Northampton' >>> data['language'] = 'Python' >>> url_values = urllib.parse.urlencode(data) >>> print(url_values) # The order may differ from below. name=Somebody+Here&language=Python&location=Northampton >>> url = 'http://www.example.com/example.cgi' >>> full_url = url + '?' + url_values >>> data = urllib.request.urlopen(full_url) Notice that the full URL is created by adding a ‘?’ to the URL, followed by the encoded values. ---------- Footnotes ---------- (1) https://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13  File: python.info, Node: Headers, Prev: Data, Up: Fetching URLs 10.12.2.2 Headers ................. We’ll discuss here one particular HTTP header, to illustrate how to add headers to your HTTP request. Some websites (1) dislike being browsed by programs, or send different versions to different browsers (2). By default urllib identifies itself as ‘Python-urllib/x.y’ (where ‘x’ and ‘y’ are the major and minor version numbers of the Python release, e.g. ‘Python-urllib/2.5’), which may confuse the site, or just plain not work. The way a browser identifies itself is through the ‘User-Agent’ header (3). When you create a Request object you can pass a dictionary of headers in. The following example makes the same request as above, but identifies itself as a version of Internet Explorer (4). import urllib.parse import urllib.request url = 'http://www.someserver.com/cgi-bin/register.cgi' user_agent = 'Mozilla/5.0 (Windows NT 6.1; Win64; x64)' values = {'name': 'Michael Foord', 'location': 'Northampton', 'language': 'Python' } headers = {'User-Agent': user_agent} data = urllib.parse.urlencode(values) data = data.encode('ascii') req = urllib.request.Request(url, data, headers) with urllib.request.urlopen(req) as response: the_page = response.read() The response also has two useful methods. See the section on *note info and geturl: 3f40. which comes after we have a look at what happens when things go wrong. ---------- Footnotes ---------- (1) (1) Google for example. (2) (2) Browser sniffing is a very bad practice for website design - building sites using web standards is much more sensible. Unfortunately a lot of sites still send different versions to different browsers. (3) (3) The user agent for MSIE 6 is `‘Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)’' (4) (4) For details of more HTTP request headers, see Quick Reference to HTTP Headers (http://jkorpela.fi/http.html).  File: python.info, Node: Handling Exceptions<2>, Next: info and geturl, Prev: Fetching URLs, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.3 Handling Exceptions --------------------------- `urlopen' raises ‘URLError’ when it cannot handle a response (though as usual with Python APIs, built-in exceptions such as *note ValueError: 1fb, *note TypeError: 192. etc. may also be raised). ‘HTTPError’ is the subclass of ‘URLError’ raised in the specific case of HTTP URLs. The exception classes are exported from the *note urllib.error: 11e. module. * Menu: * URLError:: * HTTPError:: * Wrapping it Up::  File: python.info, Node: URLError, Next: HTTPError, Up: Handling Exceptions<2> 10.12.3.1 URLError .................. Often, URLError is raised because there is no network connection (no route to the specified server), or the specified server doesn’t exist. In this case, the exception raised will have a ‘reason’ attribute, which is a tuple containing an error code and a text error message. e.g. >>> req = urllib.request.Request('http://www.pretend_server.org') >>> try: urllib.request.urlopen(req) ... except urllib.error.URLError as e: ... print(e.reason) ... (4, 'getaddrinfo failed')  File: python.info, Node: HTTPError, Next: Wrapping it Up, Prev: URLError, Up: Handling Exceptions<2> 10.12.3.2 HTTPError ................... Every HTTP response from the server contains a numeric “status code”. Sometimes the status code indicates that the server is unable to fulfil the request. The default handlers will handle some of these responses for you (for example, if the response is a “redirection” that requests the client fetch the document from a different URL, urllib will handle that for you). For those it can’t handle, urlopen will raise an ‘HTTPError’. Typical errors include ‘404’ (page not found), ‘403’ (request forbidden), and ‘401’ (authentication required). See section 10 of RFC 2616(1) for a reference on all the HTTP error codes. The ‘HTTPError’ instance raised will have an integer ‘code’ attribute, which corresponds to the error sent by the server. * Menu: * Error Codes:: ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: Error Codes, Up: HTTPError 10.12.3.3 Error Codes ..................... Because the default handlers handle redirects (codes in the 300 range), and codes in the 100–299 range indicate success, you will usually only see error codes in the 400–599 range. *note http.server.BaseHTTPRequestHandler.responses: 29d9. is a useful dictionary of response codes in that shows all the response codes used by RFC 2616(1). The dictionary is reproduced here for convenience # Table mapping response codes to messages; entries have the # form {code: (shortmessage, longmessage)}. responses = { 100: ('Continue', 'Request received, please continue'), 101: ('Switching Protocols', 'Switching to new protocol; obey Upgrade header'), 200: ('OK', 'Request fulfilled, document follows'), 201: ('Created', 'Document created, URL follows'), 202: ('Accepted', 'Request accepted, processing continues off-line'), 203: ('Non-Authoritative Information', 'Request fulfilled from cache'), 204: ('No Content', 'Request fulfilled, nothing follows'), 205: ('Reset Content', 'Clear input form for further input.'), 206: ('Partial Content', 'Partial content follows.'), 300: ('Multiple Choices', 'Object has several resources -- see URI list'), 301: ('Moved Permanently', 'Object moved permanently -- see URI list'), 302: ('Found', 'Object moved temporarily -- see URI list'), 303: ('See Other', 'Object moved -- see Method and URL list'), 304: ('Not Modified', 'Document has not changed since given time'), 305: ('Use Proxy', 'You must use proxy specified in Location to access this ' 'resource.'), 307: ('Temporary Redirect', 'Object moved temporarily -- see URI list'), 400: ('Bad Request', 'Bad request syntax or unsupported method'), 401: ('Unauthorized', 'No permission -- see authorization schemes'), 402: ('Payment Required', 'No payment -- see charging schemes'), 403: ('Forbidden', 'Request forbidden -- authorization will not help'), 404: ('Not Found', 'Nothing matches the given URI'), 405: ('Method Not Allowed', 'Specified method is invalid for this server.'), 406: ('Not Acceptable', 'URI not available in preferred format.'), 407: ('Proxy Authentication Required', 'You must authenticate with ' 'this proxy before proceeding.'), 408: ('Request Timeout', 'Request timed out; try again later.'), 409: ('Conflict', 'Request conflict.'), 410: ('Gone', 'URI no longer exists and has been permanently removed.'), 411: ('Length Required', 'Client must specify Content-Length.'), 412: ('Precondition Failed', 'Precondition in headers is false.'), 413: ('Request Entity Too Large', 'Entity is too large.'), 414: ('Request-URI Too Long', 'URI is too long.'), 415: ('Unsupported Media Type', 'Entity body in unsupported format.'), 416: ('Requested Range Not Satisfiable', 'Cannot satisfy request range.'), 417: ('Expectation Failed', 'Expect condition could not be satisfied.'), 500: ('Internal Server Error', 'Server got itself in trouble'), 501: ('Not Implemented', 'Server does not support this operation'), 502: ('Bad Gateway', 'Invalid responses from another server/proxy.'), 503: ('Service Unavailable', 'The server cannot process the request due to a high load'), 504: ('Gateway Timeout', 'The gateway server did not receive a timely response'), 505: ('HTTP Version Not Supported', 'Cannot fulfill request.'), } When an error is raised the server responds by returning an HTTP error code `and' an error page. You can use the ‘HTTPError’ instance as a response on the page returned. This means that as well as the code attribute, it also has read, geturl, and info, methods as returned by the ‘urllib.response’ module: >>> req = urllib.request.Request('http://www.python.org/fish.html') >>> try: ... urllib.request.urlopen(req) ... except urllib.error.HTTPError as e: ... print(e.code) ... print(e.read()) ... 404 b'\n\n\nPage Not Found\n ... ---------- Footnotes ---------- (1) https://tools.ietf.org/html/rfc2616.html  File: python.info, Node: Wrapping it Up, Prev: HTTPError, Up: Handling Exceptions<2> 10.12.3.4 Wrapping it Up ........................ So if you want to be prepared for ‘HTTPError’ `or' ‘URLError’ there are two basic approaches. I prefer the second approach. * Menu: * Number 1:: * Number 2::  File: python.info, Node: Number 1, Next: Number 2, Up: Wrapping it Up 10.12.3.5 Number 1 .................. from urllib.request import Request, urlopen from urllib.error import URLError, HTTPError req = Request(someurl) try: response = urlopen(req) except HTTPError as e: print('The server couldn\'t fulfill the request.') print('Error code: ', e.code) except URLError as e: print('We failed to reach a server.') print('Reason: ', e.reason) else: # everything is fine Note: The ‘except HTTPError’ `must' come first, otherwise ‘except URLError’ will `also' catch an ‘HTTPError’.  File: python.info, Node: Number 2, Prev: Number 1, Up: Wrapping it Up 10.12.3.6 Number 2 .................. from urllib.request import Request, urlopen from urllib.error import URLError req = Request(someurl) try: response = urlopen(req) except URLError as e: if hasattr(e, 'reason'): print('We failed to reach a server.') print('Reason: ', e.reason) elif hasattr(e, 'code'): print('The server couldn\'t fulfill the request.') print('Error code: ', e.code) else: # everything is fine  File: python.info, Node: info and geturl, Next: Openers and Handlers, Prev: Handling Exceptions<2>, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.4 info and geturl ----------------------- The response returned by urlopen (or the ‘HTTPError’ instance) has two useful methods ‘info()’ and ‘geturl()’ and is defined in the module *note urllib.response: 121.. `geturl' - this returns the real URL of the page fetched. This is useful because ‘urlopen’ (or the opener object used) may have followed a redirect. The URL of the page fetched may not be the same as the URL requested. `info' - this returns a dictionary-like object that describes the page fetched, particularly the headers sent by the server. It is currently an ‘http.client.HTTPMessage’ instance. Typical headers include ‘Content-length’, ‘Content-type’, and so on. See the Quick Reference to HTTP Headers(1) for a useful listing of HTTP headers with brief explanations of their meaning and use. ---------- Footnotes ---------- (1) http://jkorpela.fi/http.html  File: python.info, Node: Openers and Handlers, Next: Basic Authentication, Prev: info and geturl, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.5 Openers and Handlers ---------------------------- When you fetch a URL you use an opener (an instance of the perhaps confusingly-named *note urllib.request.OpenerDirector: 2938.). Normally we have been using the default opener - via ‘urlopen’ - but you can create custom openers. Openers use handlers. All the “heavy lifting” is done by the handlers. Each handler knows how to open URLs for a particular URL scheme (http, ftp, etc.), or how to handle an aspect of URL opening, for example HTTP redirections or HTTP cookies. You will want to create openers if you want to fetch URLs with specific handlers installed, for example to get an opener that handles cookies, or to get an opener that does not handle redirections. To create an opener, instantiate an ‘OpenerDirector’, and then call ‘.add_handler(some_handler_instance)’ repeatedly. Alternatively, you can use ‘build_opener’, which is a convenience function for creating opener objects with a single function call. ‘build_opener’ adds several handlers by default, but provides a quick way to add more and/or override the default handlers. Other sorts of handlers you might want to can handle proxies, authentication, and other common but slightly specialised situations. ‘install_opener’ can be used to make an ‘opener’ object the (global) default opener. This means that calls to ‘urlopen’ will use the opener you have installed. Opener objects have an ‘open’ method, which can be called directly to fetch urls in the same way as the ‘urlopen’ function: there’s no need to call ‘install_opener’, except as a convenience.  File: python.info, Node: Basic Authentication, Next: Proxies, Prev: Openers and Handlers, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.6 Basic Authentication ---------------------------- To illustrate creating and installing a handler we will use the ‘HTTPBasicAuthHandler’. For a more detailed discussion of this subject – including an explanation of how Basic Authentication works - see the Basic Authentication Tutorial(1). When authentication is required, the server sends a header (as well as the 401 error code) requesting authentication. This specifies the authentication scheme and a ‘realm’. The header looks like: ‘WWW-Authenticate: SCHEME realm="REALM"’. e.g. WWW-Authenticate: Basic realm="cPanel Users" The client should then retry the request with the appropriate name and password for the realm included as a header in the request. This is ‘basic authentication’. In order to simplify this process we can create an instance of ‘HTTPBasicAuthHandler’ and an opener to use this handler. The ‘HTTPBasicAuthHandler’ uses an object called a password manager to handle the mapping of URLs and realms to passwords and usernames. If you know what the realm is (from the authentication header sent by the server), then you can use a ‘HTTPPasswordMgr’. Frequently one doesn’t care what the realm is. In that case, it is convenient to use ‘HTTPPasswordMgrWithDefaultRealm’. This allows you to specify a default username and password for a URL. This will be supplied in the absence of you providing an alternative combination for a specific realm. We indicate this by providing ‘None’ as the realm argument to the ‘add_password’ method. The top-level URL is the first URL that requires authentication. URLs “deeper” than the URL you pass to .add_password() will also match. # create a password manager password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm() # Add the username and password. # If we knew the realm, we could use it instead of None. top_level_url = "http://example.com/foo/" password_mgr.add_password(None, top_level_url, username, password) handler = urllib.request.HTTPBasicAuthHandler(password_mgr) # create "opener" (OpenerDirector instance) opener = urllib.request.build_opener(handler) # use the opener to fetch a URL opener.open(a_url) # Install the opener. # Now all calls to urllib.request.urlopen use our opener. urllib.request.install_opener(opener) Note: In the above example we only supplied our ‘HTTPBasicAuthHandler’ to ‘build_opener’. By default openers have the handlers for normal situations – ‘ProxyHandler’ (if a proxy setting such as an ‘http_proxy’ environment variable is set), ‘UnknownHandler’, ‘HTTPHandler’, ‘HTTPDefaultErrorHandler’, ‘HTTPRedirectHandler’, ‘FTPHandler’, ‘FileHandler’, ‘DataHandler’, ‘HTTPErrorProcessor’. ‘top_level_url’ is in fact `either' a full URL (including the ‘http:’ scheme component and the hostname and optionally the port number) e.g. ‘"http://example.com/"’ `or' an “authority” (i.e. the hostname, optionally including the port number) e.g. ‘"example.com"’ or ‘"example.com:8080"’ (the latter example includes a port number). The authority, if present, must NOT contain the “userinfo” component - for example ‘"joe:password@example.com"’ is not correct. ---------- Footnotes ---------- (1) http://www.voidspace.org.uk/python/articles/authentication.shtml  File: python.info, Node: Proxies, Next: Sockets and Layers, Prev: Basic Authentication, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.7 Proxies --------------- `urllib' will auto-detect your proxy settings and use those. This is through the ‘ProxyHandler’, which is part of the normal handler chain when a proxy setting is detected. Normally that’s a good thing, but there are occasions when it may not be helpful (1). One way to do this is to setup our own ‘ProxyHandler’, with no proxies defined. This is done using similar steps to setting up a Basic Authentication(2) handler: >>> proxy_support = urllib.request.ProxyHandler({}) >>> opener = urllib.request.build_opener(proxy_support) >>> urllib.request.install_opener(opener) Note: Currently ‘urllib.request’ `does not' support fetching of ‘https’ locations through a proxy. However, this can be enabled by extending urllib.request as shown in the recipe (3). Note: ‘HTTP_PROXY’ will be ignored if a variable ‘REQUEST_METHOD’ is set; see the documentation on *note getproxies(): 2947. ---------- Footnotes ---------- (1) (5) In my case I have to use a proxy to access the internet at work. If you attempt to fetch `localhost' URLs through this proxy it blocks them. IE is set to use the proxy, which urllib picks up on. In order to test scripts with a localhost server, I have to prevent urllib from using the proxy. (2) http://www.voidspace.org.uk/python/articles/authentication.shtml (3) (6) urllib opener for SSL proxy (CONNECT method): ASPN Cookbook Recipe (https://code.activestate.com/recipes/456195/).  File: python.info, Node: Sockets and Layers, Next: Footnotes, Prev: Proxies, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.8 Sockets and Layers -------------------------- The Python support for fetching resources from the web is layered. urllib uses the *note http.client: 94. library, which in turn uses the socket library. As of Python 2.3 you can specify how long a socket should wait for a response before timing out. This can be useful in applications which have to fetch web pages. By default the socket module has `no timeout' and can hang. Currently, the socket timeout is not exposed at the http.client or urllib.request levels. However, you can set the default timeout globally for all sockets using import socket import urllib.request # timeout in seconds timeout = 10 socket.setdefaulttimeout(timeout) # this call to urllib.request.urlopen now uses the default timeout # we have set in the socket module req = urllib.request.Request('http://www.voidspace.org.uk') response = urllib.request.urlopen(req) __________________________________________________________________  File: python.info, Node: Footnotes, Prev: Sockets and Layers, Up: HOWTO Fetch Internet Resources Using The urllib Package 10.12.9 Footnotes ----------------- This document was reviewed and revised by John Lee.  File: python.info, Node: Argparse Tutorial, Next: An introduction to the ipaddress module, Prev: HOWTO Fetch Internet Resources Using The urllib Package, Up: Python HOWTOs 10.13 Argparse Tutorial ======================= author: Tshepang Lekhonkhobe This tutorial is intended to be a gentle introduction to *note argparse: 6, the recommended command-line parsing module in the Python standard library. Note: There are two other modules that fulfill the same task, namely *note getopt: 87. (an equivalent for ‘getopt()’ from the C language) and the deprecated *note optparse: c3. Note also that *note argparse: 6. is based on *note optparse: c3, and therefore very similar in terms of usage. * Menu: * Concepts:: * The basics:: * Introducing Positional arguments:: * Introducing Optional arguments:: * Combining Positional and Optional arguments:: * Getting a little more advanced:: * Conclusion::  File: python.info, Node: Concepts, Next: The basics, Up: Argparse Tutorial 10.13.1 Concepts ---------------- Let’s show the sort of functionality that we are going to explore in this introductory tutorial by making use of the ‘ls’ command: $ ls cpython devguide prog.py pypy rm-unused-function.patch $ ls pypy ctypes_configure demo dotviewer include lib_pypy lib-python ... $ ls -l total 20 drwxr-xr-x 19 wena wena 4096 Feb 18 18:51 cpython drwxr-xr-x 4 wena wena 4096 Feb 8 12:04 devguide -rwxr-xr-x 1 wena wena 535 Feb 19 00:05 prog.py drwxr-xr-x 14 wena wena 4096 Feb 7 00:59 pypy -rw-r--r-- 1 wena wena 741 Feb 18 01:01 rm-unused-function.patch $ ls --help Usage: ls [OPTION]... [FILE]... List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuvSUX nor --sort is specified. ... A few concepts we can learn from the four commands: * The ‘ls’ command is useful when run without any options at all. It defaults to displaying the contents of the current directory. * If we want beyond what it provides by default, we tell it a bit more. In this case, we want it to display a different directory, ‘pypy’. What we did is specify what is known as a positional argument. It’s named so because the program should know what to do with the value, solely based on where it appears on the command line. This concept is more relevant to a command like ‘cp’, whose most basic usage is ‘cp SRC DEST’. The first position is `what you want copied,' and the second position is `where you want it copied to'. * Now, say we want to change behaviour of the program. In our example, we display more info for each file instead of just showing the file names. The ‘-l’ in that case is known as an optional argument. * That’s a snippet of the help text. It’s very useful in that you can come across a program you have never used before, and can figure out how it works simply by reading its help text.  File: python.info, Node: The basics, Next: Introducing Positional arguments, Prev: Concepts, Up: Argparse Tutorial 10.13.2 The basics ------------------ Let us start with a very simple example which does (almost) nothing: import argparse parser = argparse.ArgumentParser() parser.parse_args() Following is a result of running the code: $ python3 prog.py $ python3 prog.py --help usage: prog.py [-h] optional arguments: -h, --help show this help message and exit $ python3 prog.py --verbose usage: prog.py [-h] prog.py: error: unrecognized arguments: --verbose $ python3 prog.py foo usage: prog.py [-h] prog.py: error: unrecognized arguments: foo Here is what is happening: * Running the script without any options results in nothing displayed to stdout. Not so useful. * The second one starts to display the usefulness of the *note argparse: 6. module. We have done almost nothing, but already we get a nice help message. * The ‘--help’ option, which can also be shortened to ‘-h’, is the only option we get for free (i.e. no need to specify it). Specifying anything else results in an error. But even then, we do get a useful usage message, also for free.  File: python.info, Node: Introducing Positional arguments, Next: Introducing Optional arguments, Prev: The basics, Up: Argparse Tutorial 10.13.3 Introducing Positional arguments ---------------------------------------- An example: import argparse parser = argparse.ArgumentParser() parser.add_argument("echo") args = parser.parse_args() print(args.echo) And running the code: $ python3 prog.py usage: prog.py [-h] echo prog.py: error: the following arguments are required: echo $ python3 prog.py --help usage: prog.py [-h] echo positional arguments: echo optional arguments: -h, --help show this help message and exit $ python3 prog.py foo foo Here is what’s happening: * We’ve added the ‘add_argument()’ method, which is what we use to specify which command-line options the program is willing to accept. In this case, I’ve named it ‘echo’ so that it’s in line with its function. * Calling our program now requires us to specify an option. * The ‘parse_args()’ method actually returns some data from the options specified, in this case, ‘echo’. * The variable is some form of ‘magic’ that *note argparse: 6. performs for free (i.e. no need to specify which variable that value is stored in). You will also notice that its name matches the string argument given to the method, ‘echo’. Note however that, although the help display looks nice and all, it currently is not as helpful as it can be. For example we see that we got ‘echo’ as a positional argument, but we don’t know what it does, other than by guessing or by reading the source code. So, let’s make it a bit more useful: import argparse parser = argparse.ArgumentParser() parser.add_argument("echo", help="echo the string you use here") args = parser.parse_args() print(args.echo) And we get: $ python3 prog.py -h usage: prog.py [-h] echo positional arguments: echo echo the string you use here optional arguments: -h, --help show this help message and exit Now, how about doing something even more useful: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", help="display a square of a given number") args = parser.parse_args() print(args.square**2) Following is a result of running the code: $ python3 prog.py 4 Traceback (most recent call last): File "prog.py", line 5, in print(args.square**2) TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int' That didn’t go so well. That’s because *note argparse: 6. treats the options we give it as strings, unless we tell it otherwise. So, let’s tell *note argparse: 6. to treat that input as an integer: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", help="display a square of a given number", type=int) args = parser.parse_args() print(args.square**2) Following is a result of running the code: $ python3 prog.py 4 16 $ python3 prog.py four usage: prog.py [-h] square prog.py: error: argument square: invalid int value: 'four' That went well. The program now even helpfully quits on bad illegal input before proceeding.  File: python.info, Node: Introducing Optional arguments, Next: Combining Positional and Optional arguments, Prev: Introducing Positional arguments, Up: Argparse Tutorial 10.13.4 Introducing Optional arguments -------------------------------------- So far we have been playing with positional arguments. Let us have a look on how to add optional ones: import argparse parser = argparse.ArgumentParser() parser.add_argument("--verbosity", help="increase output verbosity") args = parser.parse_args() if args.verbosity: print("verbosity turned on") And the output: $ python3 prog.py --verbosity 1 verbosity turned on $ python3 prog.py $ python3 prog.py --help usage: prog.py [-h] [--verbosity VERBOSITY] optional arguments: -h, --help show this help message and exit --verbosity VERBOSITY increase output verbosity $ python3 prog.py --verbosity usage: prog.py [-h] [--verbosity VERBOSITY] prog.py: error: argument --verbosity: expected one argument Here is what is happening: * The program is written so as to display something when ‘--verbosity’ is specified and display nothing when not. * To show that the option is actually optional, there is no error when running the program without it. Note that by default, if an optional argument isn’t used, the relevant variable, in this case ‘args.verbosity’, is given ‘None’ as a value, which is the reason it fails the truth test of the *note if: de7. statement. * The help message is a bit different. * When using the ‘--verbosity’ option, one must also specify some value, any value. The above example accepts arbitrary integer values for ‘--verbosity’, but for our simple program, only two values are actually useful, ‘True’ or ‘False’. Let’s modify the code accordingly: import argparse parser = argparse.ArgumentParser() parser.add_argument("--verbose", help="increase output verbosity", action="store_true") args = parser.parse_args() if args.verbose: print("verbosity turned on") And the output: $ python3 prog.py --verbose verbosity turned on $ python3 prog.py --verbose 1 usage: prog.py [-h] [--verbose] prog.py: error: unrecognized arguments: 1 $ python3 prog.py --help usage: prog.py [-h] [--verbose] optional arguments: -h, --help show this help message and exit --verbose increase output verbosity Here is what is happening: * The option is now more of a flag than something that requires a value. We even changed the name of the option to match that idea. Note that we now specify a new keyword, ‘action’, and give it the value ‘"store_true"’. This means that, if the option is specified, assign the value ‘True’ to ‘args.verbose’. Not specifying it implies ‘False’. * It complains when you specify a value, in true spirit of what flags actually are. * Notice the different help text. * Menu: * Short options::  File: python.info, Node: Short options, Up: Introducing Optional arguments 10.13.4.1 Short options ....................... If you are familiar with command line usage, you will notice that I haven’t yet touched on the topic of short versions of the options. It’s quite simple: import argparse parser = argparse.ArgumentParser() parser.add_argument("-v", "--verbose", help="increase output verbosity", action="store_true") args = parser.parse_args() if args.verbose: print("verbosity turned on") And here goes: $ python3 prog.py -v verbosity turned on $ python3 prog.py --help usage: prog.py [-h] [-v] optional arguments: -h, --help show this help message and exit -v, --verbose increase output verbosity Note that the new ability is also reflected in the help text.  File: python.info, Node: Combining Positional and Optional arguments, Next: Getting a little more advanced, Prev: Introducing Optional arguments, Up: Argparse Tutorial 10.13.5 Combining Positional and Optional arguments --------------------------------------------------- Our program keeps growing in complexity: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display a square of a given number") parser.add_argument("-v", "--verbose", action="store_true", help="increase output verbosity") args = parser.parse_args() answer = args.square**2 if args.verbose: print("the square of {} equals {}".format(args.square, answer)) else: print(answer) And now the output: $ python3 prog.py usage: prog.py [-h] [-v] square prog.py: error: the following arguments are required: square $ python3 prog.py 4 16 $ python3 prog.py 4 --verbose the square of 4 equals 16 $ python3 prog.py --verbose 4 the square of 4 equals 16 * We’ve brought back a positional argument, hence the complaint. * Note that the order does not matter. How about we give this program of ours back the ability to have multiple verbosity values, and actually get to use them: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display a square of a given number") parser.add_argument("-v", "--verbosity", type=int, help="increase output verbosity") args = parser.parse_args() answer = args.square**2 if args.verbosity == 2: print("the square of {} equals {}".format(args.square, answer)) elif args.verbosity == 1: print("{}^2 == {}".format(args.square, answer)) else: print(answer) And the output: $ python3 prog.py 4 16 $ python3 prog.py 4 -v usage: prog.py [-h] [-v VERBOSITY] square prog.py: error: argument -v/--verbosity: expected one argument $ python3 prog.py 4 -v 1 4^2 == 16 $ python3 prog.py 4 -v 2 the square of 4 equals 16 $ python3 prog.py 4 -v 3 16 These all look good except the last one, which exposes a bug in our program. Let’s fix it by restricting the values the ‘--verbosity’ option can accept: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display a square of a given number") parser.add_argument("-v", "--verbosity", type=int, choices=[0, 1, 2], help="increase output verbosity") args = parser.parse_args() answer = args.square**2 if args.verbosity == 2: print("the square of {} equals {}".format(args.square, answer)) elif args.verbosity == 1: print("{}^2 == {}".format(args.square, answer)) else: print(answer) And the output: $ python3 prog.py 4 -v 3 usage: prog.py [-h] [-v {0,1,2}] square prog.py: error: argument -v/--verbosity: invalid choice: 3 (choose from 0, 1, 2) $ python3 prog.py 4 -h usage: prog.py [-h] [-v {0,1,2}] square positional arguments: square display a square of a given number optional arguments: -h, --help show this help message and exit -v {0,1,2}, --verbosity {0,1,2} increase output verbosity Note that the change also reflects both in the error message as well as the help string. Now, let’s use a different approach of playing with verbosity, which is pretty common. It also matches the way the CPython executable handles its own verbosity argument (check the output of ‘python --help’): import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display the square of a given number") parser.add_argument("-v", "--verbosity", action="count", help="increase output verbosity") args = parser.parse_args() answer = args.square**2 if args.verbosity == 2: print("the square of {} equals {}".format(args.square, answer)) elif args.verbosity == 1: print("{}^2 == {}".format(args.square, answer)) else: print(answer) We have introduced another action, “count”, to count the number of occurrences of a specific optional arguments: $ python3 prog.py 4 16 $ python3 prog.py 4 -v 4^2 == 16 $ python3 prog.py 4 -vv the square of 4 equals 16 $ python3 prog.py 4 --verbosity --verbosity the square of 4 equals 16 $ python3 prog.py 4 -v 1 usage: prog.py [-h] [-v] square prog.py: error: unrecognized arguments: 1 $ python3 prog.py 4 -h usage: prog.py [-h] [-v] square positional arguments: square display a square of a given number optional arguments: -h, --help show this help message and exit -v, --verbosity increase output verbosity $ python3 prog.py 4 -vvv 16 * Yes, it’s now more of a flag (similar to ‘action="store_true"’) in the previous version of our script. That should explain the complaint. * It also behaves similar to “store_true” action. * Now here’s a demonstration of what the “count” action gives. You’ve probably seen this sort of usage before. * And if you don’t specify the ‘-v’ flag, that flag is considered to have ‘None’ value. * As should be expected, specifying the long form of the flag, we should get the same output. * Sadly, our help output isn’t very informative on the new ability our script has acquired, but that can always be fixed by improving the documentation for our script (e.g. via the ‘help’ keyword argument). * That last output exposes a bug in our program. Let’s fix: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display a square of a given number") parser.add_argument("-v", "--verbosity", action="count", help="increase output verbosity") args = parser.parse_args() answer = args.square**2 # bugfix: replace == with >= if args.verbosity >= 2: print("the square of {} equals {}".format(args.square, answer)) elif args.verbosity >= 1: print("{}^2 == {}".format(args.square, answer)) else: print(answer) And this is what it gives: $ python3 prog.py 4 -vvv the square of 4 equals 16 $ python3 prog.py 4 -vvvv the square of 4 equals 16 $ python3 prog.py 4 Traceback (most recent call last): File "prog.py", line 11, in if args.verbosity >= 2: TypeError: '>=' not supported between instances of 'NoneType' and 'int' * First output went well, and fixes the bug we had before. That is, we want any value >= 2 to be as verbose as possible. * Third output not so good. Let’s fix that bug: import argparse parser = argparse.ArgumentParser() parser.add_argument("square", type=int, help="display a square of a given number") parser.add_argument("-v", "--verbosity", action="count", default=0, help="increase output verbosity") args = parser.parse_args() answer = args.square**2 if args.verbosity >= 2: print("the square of {} equals {}".format(args.square, answer)) elif args.verbosity >= 1: print("{}^2 == {}".format(args.square, answer)) else: print(answer) We’ve just introduced yet another keyword, ‘default’. We’ve set it to ‘0’ in order to make it comparable to the other int values. Remember that by default, if an optional argument isn’t specified, it gets the ‘None’ value, and that cannot be compared to an int value (hence the *note TypeError: 192. exception). And: $ python3 prog.py 4 16 You can go quite far just with what we’ve learned so far, and we have only scratched the surface. The *note argparse: 6. module is very powerful, and we’ll explore a bit more of it before we end this tutorial.  File: python.info, Node: Getting a little more advanced, Next: Conclusion, Prev: Combining Positional and Optional arguments, Up: Argparse Tutorial 10.13.6 Getting a little more advanced -------------------------------------- What if we wanted to expand our tiny program to perform other powers, not just squares: import argparse parser = argparse.ArgumentParser() parser.add_argument("x", type=int, help="the base") parser.add_argument("y", type=int, help="the exponent") parser.add_argument("-v", "--verbosity", action="count", default=0) args = parser.parse_args() answer = args.x**args.y if args.verbosity >= 2: print("{} to the power {} equals {}".format(args.x, args.y, answer)) elif args.verbosity >= 1: print("{}^{} == {}".format(args.x, args.y, answer)) else: print(answer) Output: $ python3 prog.py usage: prog.py [-h] [-v] x y prog.py: error: the following arguments are required: x, y $ python3 prog.py -h usage: prog.py [-h] [-v] x y positional arguments: x the base y the exponent optional arguments: -h, --help show this help message and exit -v, --verbosity $ python3 prog.py 4 2 -v 4^2 == 16 Notice that so far we’ve been using verbosity level to `change' the text that gets displayed. The following example instead uses verbosity level to display `more' text instead: import argparse parser = argparse.ArgumentParser() parser.add_argument("x", type=int, help="the base") parser.add_argument("y", type=int, help="the exponent") parser.add_argument("-v", "--verbosity", action="count", default=0) args = parser.parse_args() answer = args.x**args.y if args.verbosity >= 2: print("Running '{}'".format(__file__)) if args.verbosity >= 1: print("{}^{} == ".format(args.x, args.y), end="") print(answer) Output: $ python3 prog.py 4 2 16 $ python3 prog.py 4 2 -v 4^2 == 16 $ python3 prog.py 4 2 -vv Running 'prog.py' 4^2 == 16 * Menu: * Conflicting options::  File: python.info, Node: Conflicting options, Up: Getting a little more advanced 10.13.6.1 Conflicting options ............................. So far, we have been working with two methods of an *note argparse.ArgumentParser: 695. instance. Let’s introduce a third one, ‘add_mutually_exclusive_group()’. It allows for us to specify options that conflict with each other. Let’s also change the rest of the program so that the new functionality makes more sense: we’ll introduce the ‘--quiet’ option, which will be the opposite of the ‘--verbose’ one: import argparse parser = argparse.ArgumentParser() group = parser.add_mutually_exclusive_group() group.add_argument("-v", "--verbose", action="store_true") group.add_argument("-q", "--quiet", action="store_true") parser.add_argument("x", type=int, help="the base") parser.add_argument("y", type=int, help="the exponent") args = parser.parse_args() answer = args.x**args.y if args.quiet: print(answer) elif args.verbose: print("{} to the power {} equals {}".format(args.x, args.y, answer)) else: print("{}^{} == {}".format(args.x, args.y, answer)) Our program is now simpler, and we’ve lost some functionality for the sake of demonstration. Anyways, here’s the output: $ python3 prog.py 4 2 4^2 == 16 $ python3 prog.py 4 2 -q 16 $ python3 prog.py 4 2 -v 4 to the power 2 equals 16 $ python3 prog.py 4 2 -vq usage: prog.py [-h] [-v | -q] x y prog.py: error: argument -q/--quiet: not allowed with argument -v/--verbose $ python3 prog.py 4 2 -v --quiet usage: prog.py [-h] [-v | -q] x y prog.py: error: argument -q/--quiet: not allowed with argument -v/--verbose That should be easy to follow. I’ve added that last output so you can see the sort of flexibility you get, i.e. mixing long form options with short form ones. Before we conclude, you probably want to tell your users the main purpose of your program, just in case they don’t know: import argparse parser = argparse.ArgumentParser(description="calculate X to the power of Y") group = parser.add_mutually_exclusive_group() group.add_argument("-v", "--verbose", action="store_true") group.add_argument("-q", "--quiet", action="store_true") parser.add_argument("x", type=int, help="the base") parser.add_argument("y", type=int, help="the exponent") args = parser.parse_args() answer = args.x**args.y if args.quiet: print(answer) elif args.verbose: print("{} to the power {} equals {}".format(args.x, args.y, answer)) else: print("{}^{} == {}".format(args.x, args.y, answer)) Note that slight difference in the usage text. Note the ‘[-v | -q]’, which tells us that we can either use ‘-v’ or ‘-q’, but not both at the same time: $ python3 prog.py --help usage: prog.py [-h] [-v | -q] x y calculate X to the power of Y positional arguments: x the base y the exponent optional arguments: -h, --help show this help message and exit -v, --verbose -q, --quiet  File: python.info, Node: Conclusion, Prev: Getting a little more advanced, Up: Argparse Tutorial 10.13.7 Conclusion ------------------ The *note argparse: 6. module offers a lot more than shown here. Its docs are quite detailed and thorough, and full of examples. Having gone through this tutorial, you should easily digest them without feeling overwhelmed.  File: python.info, Node: An introduction to the ipaddress module, Next: Argument Clinic How-To, Prev: Argparse Tutorial, Up: Python HOWTOs 10.14 An introduction to the ipaddress module ============================================= author: Peter Moody author: Nick Coghlan Overview ........ This document aims to provide a gentle introduction to the *note ipaddress: a2. module. It is aimed primarily at users that aren’t already familiar with IP networking terminology, but may also be useful to network engineers wanting an overview of how *note ipaddress: a2. represents IP network addressing concepts. * Menu: * Creating Address/Network/Interface objects:: * Inspecting Address/Network/Interface Objects:: * Networks as lists of Addresses:: * Comparisons: Comparisons<4>. * Using IP Addresses with other modules:: * Getting more detail when instance creation fails::  File: python.info, Node: Creating Address/Network/Interface objects, Next: Inspecting Address/Network/Interface Objects, Up: An introduction to the ipaddress module 10.14.1 Creating Address/Network/Interface objects -------------------------------------------------- Since *note ipaddress: a2. is a module for inspecting and manipulating IP addresses, the first thing you’ll want to do is create some objects. You can use *note ipaddress: a2. to create objects from strings and integers. * Menu: * A Note on IP Versions:: * IP Host Addresses:: * Defining Networks:: * Host Interfaces::  File: python.info, Node: A Note on IP Versions, Next: IP Host Addresses, Up: Creating Address/Network/Interface objects 10.14.1.1 A Note on IP Versions ............................... For readers that aren’t particularly familiar with IP addressing, it’s important to know that the Internet Protocol is currently in the process of moving from version 4 of the protocol to version 6. This transition is occurring largely because version 4 of the protocol doesn’t provide enough addresses to handle the needs of the whole world, especially given the increasing number of devices with direct connections to the internet. Explaining the details of the differences between the two versions of the protocol is beyond the scope of this introduction, but readers need to at least be aware that these two versions exist, and it will sometimes be necessary to force the use of one version or the other.  File: python.info, Node: IP Host Addresses, Next: Defining Networks, Prev: A Note on IP Versions, Up: Creating Address/Network/Interface objects 10.14.1.2 IP Host Addresses ........................... Addresses, often referred to as “host addresses” are the most basic unit when working with IP addressing. The simplest way to create addresses is to use the *note ipaddress.ip_address(): 2c16. factory function, which automatically determines whether to create an IPv4 or IPv6 address based on the passed in value: >>> ipaddress.ip_address('192.0.2.1') IPv4Address('192.0.2.1') >>> ipaddress.ip_address('2001:DB8::1') IPv6Address('2001:db8::1') Addresses can also be created directly from integers. Values that will fit within 32 bits are assumed to be IPv4 addresses: >>> ipaddress.ip_address(3221225985) IPv4Address('192.0.2.1') >>> ipaddress.ip_address(42540766411282592856903984951653826561) IPv6Address('2001:db8::1') To force the use of IPv4 or IPv6 addresses, the relevant classes can be invoked directly. This is particularly useful to force creation of IPv6 addresses for small integers: >>> ipaddress.ip_address(1) IPv4Address('0.0.0.1') >>> ipaddress.IPv4Address(1) IPv4Address('0.0.0.1') >>> ipaddress.IPv6Address(1) IPv6Address('::1')  File: python.info, Node: Defining Networks, Next: Host Interfaces, Prev: IP Host Addresses, Up: Creating Address/Network/Interface objects 10.14.1.3 Defining Networks ........................... Host addresses are usually grouped together into IP networks, so *note ipaddress: a2. provides a way to create, inspect and manipulate network definitions. IP network objects are constructed from strings that define the range of host addresses that are part of that network. The simplest form for that information is a “network address/network prefix” pair, where the prefix defines the number of leading bits that are compared to determine whether or not an address is part of the network and the network address defines the expected value of those bits. As for addresses, a factory function is provided that determines the correct IP version automatically: >>> ipaddress.ip_network('192.0.2.0/24') IPv4Network('192.0.2.0/24') >>> ipaddress.ip_network('2001:db8::0/96') IPv6Network('2001:db8::/96') Network objects cannot have any host bits set. The practical effect of this is that ‘192.0.2.1/24’ does not describe a network. Such definitions are referred to as interface objects since the ip-on-a-network notation is commonly used to describe network interfaces of a computer on a given network and are described further in the next section. By default, attempting to create a network object with host bits set will result in *note ValueError: 1fb. being raised. To request that the additional bits instead be coerced to zero, the flag ‘strict=False’ can be passed to the constructor: >>> ipaddress.ip_network('192.0.2.1/24') Traceback (most recent call last): ... ValueError: 192.0.2.1/24 has host bits set >>> ipaddress.ip_network('192.0.2.1/24', strict=False) IPv4Network('192.0.2.0/24') While the string form offers significantly more flexibility, networks can also be defined with integers, just like host addresses. In this case, the network is considered to contain only the single address identified by the integer, so the network prefix includes the entire network address: >>> ipaddress.ip_network(3221225984) IPv4Network('192.0.2.0/32') >>> ipaddress.ip_network(42540766411282592856903984951653826560) IPv6Network('2001:db8::/128') As with addresses, creation of a particular kind of network can be forced by calling the class constructor directly instead of using the factory function.  File: python.info, Node: Host Interfaces, Prev: Defining Networks, Up: Creating Address/Network/Interface objects 10.14.1.4 Host Interfaces ......................... As mentioned just above, if you need to describe an address on a particular network, neither the address nor the network classes are sufficient. Notation like ‘192.0.2.1/24’ is commonly used by network engineers and the people who write tools for firewalls and routers as shorthand for “the host ‘192.0.2.1’ on the network ‘192.0.2.0/24’”, Accordingly, *note ipaddress: a2. provides a set of hybrid classes that associate an address with a particular network. The interface for creation is identical to that for defining network objects, except that the address portion isn’t constrained to being a network address. >>> ipaddress.ip_interface('192.0.2.1/24') IPv4Interface('192.0.2.1/24') >>> ipaddress.ip_interface('2001:db8::1/96') IPv6Interface('2001:db8::1/96') Integer inputs are accepted (as with networks), and use of a particular IP version can be forced by calling the relevant constructor directly.  File: python.info, Node: Inspecting Address/Network/Interface Objects, Next: Networks as lists of Addresses, Prev: Creating Address/Network/Interface objects, Up: An introduction to the ipaddress module 10.14.2 Inspecting Address/Network/Interface Objects ---------------------------------------------------- You’ve gone to the trouble of creating an IPv(4|6)(Address|Network|Interface) object, so you probably want to get information about it. *note ipaddress: a2. tries to make doing this easy and intuitive. Extracting the IP version: >>> addr4 = ipaddress.ip_address('192.0.2.1') >>> addr6 = ipaddress.ip_address('2001:db8::1') >>> addr6.version 6 >>> addr4.version 4 Obtaining the network from an interface: >>> host4 = ipaddress.ip_interface('192.0.2.1/24') >>> host4.network IPv4Network('192.0.2.0/24') >>> host6 = ipaddress.ip_interface('2001:db8::1/96') >>> host6.network IPv6Network('2001:db8::/96') Finding out how many individual addresses are in a network: >>> net4 = ipaddress.ip_network('192.0.2.0/24') >>> net4.num_addresses 256 >>> net6 = ipaddress.ip_network('2001:db8::0/96') >>> net6.num_addresses 4294967296 Iterating through the “usable” addresses on a network: >>> net4 = ipaddress.ip_network('192.0.2.0/24') >>> for x in net4.hosts(): ... print(x) 192.0.2.1 192.0.2.2 192.0.2.3 192.0.2.4 ... 192.0.2.252 192.0.2.253 192.0.2.254 Obtaining the netmask (i.e. set bits corresponding to the network prefix) or the hostmask (any bits that are not part of the netmask): >>> net4 = ipaddress.ip_network('192.0.2.0/24') >>> net4.netmask IPv4Address('255.255.255.0') >>> net4.hostmask IPv4Address('0.0.0.255') >>> net6 = ipaddress.ip_network('2001:db8::0/96') >>> net6.netmask IPv6Address('ffff:ffff:ffff:ffff:ffff:ffff::') >>> net6.hostmask IPv6Address('::ffff:ffff') Exploding or compressing the address: >>> addr6.exploded '2001:0db8:0000:0000:0000:0000:0000:0001' >>> addr6.compressed '2001:db8::1' >>> net6.exploded '2001:0db8:0000:0000:0000:0000:0000:0000/96' >>> net6.compressed '2001:db8::/96' While IPv4 doesn’t support explosion or compression, the associated objects still provide the relevant properties so that version neutral code can easily ensure the most concise or most verbose form is used for IPv6 addresses while still correctly handling IPv4 addresses.  File: python.info, Node: Networks as lists of Addresses, Next: Comparisons<4>, Prev: Inspecting Address/Network/Interface Objects, Up: An introduction to the ipaddress module 10.14.3 Networks as lists of Addresses -------------------------------------- It’s sometimes useful to treat networks as lists. This means it is possible to index them like this: >>> net4[1] IPv4Address('192.0.2.1') >>> net4[-1] IPv4Address('192.0.2.255') >>> net6[1] IPv6Address('2001:db8::1') >>> net6[-1] IPv6Address('2001:db8::ffff:ffff') It also means that network objects lend themselves to using the list membership test syntax like this: if address in network: # do something Containment testing is done efficiently based on the network prefix: >>> addr4 = ipaddress.ip_address('192.0.2.1') >>> addr4 in ipaddress.ip_network('192.0.2.0/24') True >>> addr4 in ipaddress.ip_network('192.0.3.0/24') False  File: python.info, Node: Comparisons<4>, Next: Using IP Addresses with other modules, Prev: Networks as lists of Addresses, Up: An introduction to the ipaddress module 10.14.4 Comparisons ------------------- *note ipaddress: a2. provides some simple, hopefully intuitive ways to compare objects, where it makes sense: >>> ipaddress.ip_address('192.0.2.1') < ipaddress.ip_address('192.0.2.2') True A *note TypeError: 192. exception is raised if you try to compare objects of different versions or different types.  File: python.info, Node: Using IP Addresses with other modules, Next: Getting more detail when instance creation fails, Prev: Comparisons<4>, Up: An introduction to the ipaddress module 10.14.5 Using IP Addresses with other modules --------------------------------------------- Other modules that use IP addresses (such as *note socket: ef.) usually won’t accept objects from this module directly. Instead, they must be coerced to an integer or string that the other module will accept: >>> addr4 = ipaddress.ip_address('192.0.2.1') >>> str(addr4) '192.0.2.1' >>> int(addr4) 3221225985  File: python.info, Node: Getting more detail when instance creation fails, Prev: Using IP Addresses with other modules, Up: An introduction to the ipaddress module 10.14.6 Getting more detail when instance creation fails -------------------------------------------------------- When creating address/network/interface objects using the version-agnostic factory functions, any errors will be reported as *note ValueError: 1fb. with a generic error message that simply says the passed in value was not recognized as an object of that type. The lack of a specific error is because it’s necessary to know whether the value is `supposed' to be IPv4 or IPv6 in order to provide more detail on why it has been rejected. To support use cases where it is useful to have access to this additional detail, the individual class constructors actually raise the *note ValueError: 1fb. subclasses *note ipaddress.AddressValueError: 2c1f. and *note ipaddress.NetmaskValueError: 2c44. to indicate exactly which part of the definition failed to parse correctly. The error messages are significantly more detailed when using the class constructors directly. For example: >>> ipaddress.ip_address("192.168.0.256") Traceback (most recent call last): ... ValueError: '192.168.0.256' does not appear to be an IPv4 or IPv6 address >>> ipaddress.IPv4Address("192.168.0.256") Traceback (most recent call last): ... ipaddress.AddressValueError: Octet 256 (> 255) not permitted in '192.168.0.256' >>> ipaddress.ip_network("192.168.0.1/64") Traceback (most recent call last): ... ValueError: '192.168.0.1/64' does not appear to be an IPv4 or IPv6 network >>> ipaddress.IPv4Network("192.168.0.1/64") Traceback (most recent call last): ... ipaddress.NetmaskValueError: '64' is not a valid netmask However, both of the module specific exceptions have *note ValueError: 1fb. as their parent class, so if you’re not concerned with the particular type of error, you can still write code like the following: try: network = ipaddress.IPv4Network(address) except ValueError: print('address/netmask is invalid for IPv4:', address)  File: python.info, Node: Argument Clinic How-To, Next: Instrumenting CPython with DTrace and SystemTap, Prev: An introduction to the ipaddress module, Up: Python HOWTOs 10.15 Argument Clinic How-To ============================ author: Larry Hastings Abstract ........ Argument Clinic is a preprocessor for CPython C files. Its purpose is to automate all the boilerplate involved with writing argument parsing code for “builtins”. This document shows you how to convert your first C function to work with Argument Clinic, and then introduces some advanced topics on Argument Clinic usage. Currently Argument Clinic is considered internal-only for CPython. Its use is not supported for files outside CPython, and no guarantees are made regarding backwards compatibility for future versions. In other words: if you maintain an external C extension for CPython, you’re welcome to experiment with Argument Clinic in your own code. But the version of Argument Clinic that ships with the next version of CPython `could' be totally incompatible and break all your code. * Menu: * The Goals Of Argument Clinic:: * Basic Concepts And Usage:: * Converting Your First Function:: * Advanced Topics::  File: python.info, Node: The Goals Of Argument Clinic, Next: Basic Concepts And Usage, Up: Argument Clinic How-To 10.15.1 The Goals Of Argument Clinic ------------------------------------ Argument Clinic’s primary goal is to take over responsibility for all argument parsing code inside CPython. This means that, when you convert a function to work with Argument Clinic, that function should no longer do any of its own argument parsing—the code generated by Argument Clinic should be a “black box” to you, where CPython calls in at the top, and your code gets called at the bottom, with ‘PyObject *args’ (and maybe ‘PyObject *kwargs’) magically converted into the C variables and types you need. In order for Argument Clinic to accomplish its primary goal, it must be easy to use. Currently, working with CPython’s argument parsing library is a chore, requiring maintaining redundant information in a surprising number of places. When you use Argument Clinic, you don’t have to repeat yourself. Obviously, no one would want to use Argument Clinic unless it’s solving their problem—and without creating new problems of its own. So it’s paramount that Argument Clinic generate correct code. It’d be nice if the code was faster, too, but at the very least it should not introduce a major speed regression. (Eventually Argument Clinic `should' make a major speedup possible—we could rewrite its code generator to produce tailor-made argument parsing code, rather than calling the general-purpose CPython argument parsing library. That would make for the fastest argument parsing possible!) Additionally, Argument Clinic must be flexible enough to work with any approach to argument parsing. Python has some functions with some very strange parsing behaviors; Argument Clinic’s goal is to support all of them. Finally, the original motivation for Argument Clinic was to provide introspection “signatures” for CPython builtins. It used to be, the introspection query functions would throw an exception if you passed in a builtin. With Argument Clinic, that’s a thing of the past! One idea you should keep in mind, as you work with Argument Clinic: the more information you give it, the better job it’ll be able to do. Argument Clinic is admittedly relatively simple right now. But as it evolves it will get more sophisticated, and it should be able to do many interesting and smart things with all the information you give it.  File: python.info, Node: Basic Concepts And Usage, Next: Converting Your First Function, Prev: The Goals Of Argument Clinic, Up: Argument Clinic How-To 10.15.2 Basic Concepts And Usage -------------------------------- Argument Clinic ships with CPython; you’ll find it in ‘Tools/clinic/clinic.py’. If you run that script, specifying a C file as an argument: $ python3 Tools/clinic/clinic.py foo.c Argument Clinic will scan over the file looking for lines that look exactly like this: /*[clinic input] When it finds one, it reads everything up to a line that looks exactly like this: [clinic start generated code]*/ Everything in between these two lines is input for Argument Clinic. All of these lines, including the beginning and ending comment lines, are collectively called an Argument Clinic “block”. When Argument Clinic parses one of these blocks, it generates output. This output is rewritten into the C file immediately after the block, followed by a comment containing a checksum. The Argument Clinic block now looks like this: /*[clinic input] ... clinic input goes here ... [clinic start generated code]*/ ... clinic output goes here ... /*[clinic end generated code: checksum=...]*/ If you run Argument Clinic on the same file a second time, Argument Clinic will discard the old output and write out the new output with a fresh checksum line. However, if the input hasn’t changed, the output won’t change either. You should never modify the output portion of an Argument Clinic block. Instead, change the input until it produces the output you want. (That’s the purpose of the checksum—to detect if someone changed the output, as these edits would be lost the next time Argument Clinic writes out fresh output.) For the sake of clarity, here’s the terminology we’ll use with Argument Clinic: * The first line of the comment (‘/*[clinic input]’) is the `start line'. * The last line of the initial comment (‘[clinic start generated code]*/’) is the `end line'. * The last line (‘/*[clinic end generated code: checksum=...]*/’) is the `checksum line'. * In between the start line and the end line is the `input'. * In between the end line and the checksum line is the `output'. * All the text collectively, from the start line to the checksum line inclusively, is the `block'. (A block that hasn’t been successfully processed by Argument Clinic yet doesn’t have output or a checksum line, but it’s still considered a block.)  File: python.info, Node: Converting Your First Function, Next: Advanced Topics, Prev: Basic Concepts And Usage, Up: Argument Clinic How-To 10.15.3 Converting Your First Function -------------------------------------- The best way to get a sense of how Argument Clinic works is to convert a function to work with it. Here, then, are the bare minimum steps you’d need to follow to convert a function to work with Argument Clinic. Note that for code you plan to check in to CPython, you really should take the conversion farther, using some of the advanced concepts you’ll see later on in the document (like “return converters” and “self converters”). But we’ll keep it simple for this walkthrough so you can learn. Let’s dive in! 0. Make sure you’re working with a freshly updated checkout of the CPython trunk. 1. Find a Python builtin that calls either *note PyArg_ParseTuple(): 26a. or *note PyArg_ParseTupleAndKeywords(): 5ca, and hasn’t been converted to work with Argument Clinic yet. For my example I’m using ‘_pickle.Pickler.dump()’. 2. If the call to the ‘PyArg_Parse’ function uses any of the following format units: O& O! es es# et et# or if it has multiple calls to *note PyArg_ParseTuple(): 26a, you should choose a different function. Argument Clinic `does' support all of these scenarios. But these are advanced topics—let’s do something simpler for your first function. Also, if the function has multiple calls to *note PyArg_ParseTuple(): 26a. or *note PyArg_ParseTupleAndKeywords(): 5ca. where it supports different types for the same argument, or if the function uses something besides PyArg_Parse functions to parse its arguments, it probably isn’t suitable for conversion to Argument Clinic. Argument Clinic doesn’t support generic functions or polymorphic parameters. 3. Add the following boilerplate above the function, creating our block: /*[clinic input] [clinic start generated code]*/ 4. Cut the docstring and paste it in between the ‘[clinic]’ lines, removing all the junk that makes it a properly quoted C string. When you’re done you should have just the text, based at the left margin, with no line wider than 80 characters. (Argument Clinic will preserve indents inside the docstring.) If the old docstring had a first line that looked like a function signature, throw that line away. (The docstring doesn’t need it anymore—when you use ‘help()’ on your builtin in the future, the first line will be built automatically based on the function’s signature.) Sample: /*[clinic input] Write a pickled representation of obj to the open file. [clinic start generated code]*/ 5. If your docstring doesn’t have a “summary” line, Argument Clinic will complain. So let’s make sure it has one. The “summary” line should be a paragraph consisting of a single 80-column line at the beginning of the docstring. (Our example docstring consists solely of a summary line, so the sample code doesn’t have to change for this step.) 6. Above the docstring, enter the name of the function, followed by a blank line. This should be the Python name of the function, and should be the full dotted path to the function—it should start with the name of the module, include any sub-modules, and if the function is a method on a class it should include the class name too. Sample: /*[clinic input] _pickle.Pickler.dump Write a pickled representation of obj to the open file. [clinic start generated code]*/ 7. If this is the first time that module or class has been used with Argument Clinic in this C file, you must declare the module and/or class. Proper Argument Clinic hygiene prefers declaring these in a separate block somewhere near the top of the C file, in the same way that include files and statics go at the top. (In our sample code we’ll just show the two blocks next to each other.) The name of the class and module should be the same as the one seen by Python. Check the name defined in the *note PyModuleDef: 3888. or *note PyTypeObject: 2d6. as appropriate. When you declare a class, you must also specify two aspects of its type in C: the type declaration you’d use for a pointer to an instance of this class, and a pointer to the *note PyTypeObject: 2d6. for this class. Sample: /*[clinic input] module _pickle class _pickle.Pickler "PicklerObject *" "&Pickler_Type" [clinic start generated code]*/ /*[clinic input] _pickle.Pickler.dump Write a pickled representation of obj to the open file. [clinic start generated code]*/ 8. Declare each of the parameters to the function. Each parameter should get its own line. All the parameter lines should be indented from the function name and the docstring. The general form of these parameter lines is as follows: name_of_parameter: converter If the parameter has a default value, add that after the converter: name_of_parameter: converter = default_value Argument Clinic’s support for “default values” is quite sophisticated; please see *note the section below on default values: 3f69. for more information. Add a blank line below the parameters. What’s a “converter”? It establishes both the type of the variable used in C, and the method to convert the Python value into a C value at runtime. For now you’re going to use what’s called a “legacy converter”—a convenience syntax intended to make porting old code into Argument Clinic easier. For each parameter, copy the “format unit” for that parameter from the ‘PyArg_Parse()’ format argument and specify `that' as its converter, as a quoted string. (“format unit” is the formal name for the one-to-three character substring of the ‘format’ parameter that tells the argument parsing function what the type of the variable is and how to convert it. For more on format units please see *note Parsing arguments and building values: 2d0.) For multicharacter format units like ‘z#’, use the entire two-or-three character string. Sample: /*[clinic input] module _pickle class _pickle.Pickler "PicklerObject *" "&Pickler_Type" [clinic start generated code]*/ /*[clinic input] _pickle.Pickler.dump obj: 'O' Write a pickled representation of obj to the open file. [clinic start generated code]*/ 9. If your function has ‘|’ in the format string, meaning some parameters have default values, you can ignore it. Argument Clinic infers which parameters are optional based on whether or not they have default values. If your function has ‘$’ in the format string, meaning it takes keyword-only arguments, specify ‘*’ on a line by itself before the first keyword-only argument, indented the same as the parameter lines. (‘_pickle.Pickler.dump’ has neither, so our sample is unchanged.) 10. If the existing C function calls *note PyArg_ParseTuple(): 26a. (as opposed to *note PyArg_ParseTupleAndKeywords(): 5ca.), then all its arguments are positional-only. To mark all parameters as positional-only in Argument Clinic, add a ‘/’ on a line by itself after the last parameter, indented the same as the parameter lines. Currently this is all-or-nothing; either all parameters are positional-only, or none of them are. (In the future Argument Clinic may relax this restriction.) Sample: /*[clinic input] module _pickle class _pickle.Pickler "PicklerObject *" "&Pickler_Type" [clinic start generated code]*/ /*[clinic input] _pickle.Pickler.dump obj: 'O' / Write a pickled representation of obj to the open file. [clinic start generated code]*/ 11. It’s helpful to write a per-parameter docstring for each parameter. But per-parameter docstrings are optional; you can skip this step if you prefer. Here’s how to add a per-parameter docstring. The first line of the per-parameter docstring must be indented further than the parameter definition. The left margin of this first line establishes the left margin for the whole per-parameter docstring; all the text you write will be outdented by this amount. You can write as much text as you like, across multiple lines if you wish. Sample: /*[clinic input] module _pickle class _pickle.Pickler "PicklerObject *" "&Pickler_Type" [clinic start generated code]*/ /*[clinic input] _pickle.Pickler.dump obj: 'O' The object to be pickled. / Write a pickled representation of obj to the open file. [clinic start generated code]*/ 12. Save and close the file, then run ‘Tools/clinic/clinic.py’ on it. With luck everything worked—your block now has output, and a ‘.c.h’ file has been generated! Reopen the file in your text editor to see: /*[clinic input] _pickle.Pickler.dump obj: 'O' The object to be pickled. / Write a pickled representation of obj to the open file. [clinic start generated code]*/ static PyObject * _pickle_Pickler_dump(PicklerObject *self, PyObject *obj) /*[clinic end generated code: output=87ecad1261e02ac7 input=552eb1c0f52260d9]*/ Obviously, if Argument Clinic didn’t produce any output, it’s because it found an error in your input. Keep fixing your errors and retrying until Argument Clinic processes your file without complaint. For readability, most of the glue code has been generated to a ‘.c.h’ file. You’ll need to include that in your original ‘.c’ file, typically right after the clinic module block: #include "clinic/_pickle.c.h" 13. Double-check that the argument-parsing code Argument Clinic generated looks basically the same as the existing code. First, ensure both places use the same argument-parsing function. The existing code must call either *note PyArg_ParseTuple(): 26a. or *note PyArg_ParseTupleAndKeywords(): 5ca.; ensure that the code generated by Argument Clinic calls the `exact' same function. Second, the format string passed in to *note PyArg_ParseTuple(): 26a. or *note PyArg_ParseTupleAndKeywords(): 5ca. should be `exactly' the same as the hand-written one in the existing function, up to the colon or semi-colon. (Argument Clinic always generates its format strings with a ‘:’ followed by the name of the function. If the existing code’s format string ends with ‘;’, to provide usage help, this change is harmless—don’t worry about it.) Third, for parameters whose format units require two arguments (like a length variable, or an encoding string, or a pointer to a conversion function), ensure that the second argument is `exactly' the same between the two invocations. Fourth, inside the output portion of the block you’ll find a preprocessor macro defining the appropriate static *note PyMethodDef: e1b. structure for this builtin: #define __PICKLE_PICKLER_DUMP_METHODDEF \ {"dump", (PyCFunction)__pickle_Pickler_dump, METH_O, __pickle_Pickler_dump__doc__}, This static structure should be `exactly' the same as the existing static *note PyMethodDef: e1b. structure for this builtin. If any of these items differ in `any way', adjust your Argument Clinic function specification and rerun ‘Tools/clinic/clinic.py’ until they `are' the same. 14. Notice that the last line of its output is the declaration of your “impl” function. This is where the builtin’s implementation goes. Delete the existing prototype of the function you’re modifying, but leave the opening curly brace. Now delete its argument parsing code and the declarations of all the variables it dumps the arguments into. Notice how the Python arguments are now arguments to this impl function; if the implementation used different names for these variables, fix it. Let’s reiterate, just because it’s kind of weird. Your code should now look like this: static return_type your_function_impl(...) /*[clinic end generated code: checksum=...]*/ { ... Argument Clinic generated the checksum line and the function prototype just above it. You should write the opening (and closing) curly braces for the function, and the implementation inside. Sample: /*[clinic input] module _pickle class _pickle.Pickler "PicklerObject *" "&Pickler_Type" [clinic start generated code]*/ /*[clinic end generated code: checksum=da39a3ee5e6b4b0d3255bfef95601890afd80709]*/ /*[clinic input] _pickle.Pickler.dump obj: 'O' The object to be pickled. / Write a pickled representation of obj to the open file. [clinic start generated code]*/ PyDoc_STRVAR(__pickle_Pickler_dump__doc__, "Write a pickled representation of obj to the open file.\n" "\n" ... static PyObject * _pickle_Pickler_dump_impl(PicklerObject *self, PyObject *obj) /*[clinic end generated code: checksum=3bd30745bf206a48f8b576a1da3d90f55a0a4187]*/ { /* Check whether the Pickler was initialized correctly (issue3664). Developers often forget to call __init__() in their subclasses, which would trigger a segfault without this check. */ if (self->write == NULL) { PyErr_Format(PicklingError, "Pickler.__init__() was not called by %s.__init__()", Py_TYPE(self)->tp_name); return NULL; } if (_Pickler_ClearBuffer(self) < 0) return NULL; ... 15. Remember the macro with the *note PyMethodDef: e1b. structure for this function? Find the existing *note PyMethodDef: e1b. structure for this function and replace it with a reference to the macro. (If the builtin is at module scope, this will probably be very near the end of the file; if the builtin is a class method, this will probably be below but relatively near to the implementation.) Note that the body of the macro contains a trailing comma. So when you replace the existing static *note PyMethodDef: e1b. structure with the macro, `don’t' add a comma to the end. Sample: static struct PyMethodDef Pickler_methods[] = { __PICKLE_PICKLER_DUMP_METHODDEF __PICKLE_PICKLER_CLEAR_MEMO_METHODDEF {NULL, NULL} /* sentinel */ }; 16. Compile, then run the relevant portions of the regression-test suite. This change should not introduce any new compile-time warnings or errors, and there should be no externally-visible change to Python’s behavior. Well, except for one difference: ‘inspect.signature()’ run on your function should now provide a valid signature! Congratulations, you’ve ported your first function to work with Argument Clinic!  File: python.info, Node: Advanced Topics, Prev: Converting Your First Function, Up: Argument Clinic How-To 10.15.4 Advanced Topics ----------------------- Now that you’ve had some experience working with Argument Clinic, it’s time for some advanced topics. * Menu: * Symbolic default values:: * Renaming the C functions and variables generated by Argument Clinic:: * Converting functions using PyArg_UnpackTuple:: * Optional Groups:: * Using real Argument Clinic converters, instead of “legacy converters”: Using real Argument Clinic converters instead of “legacy converters”. * Py_buffer:: * Advanced converters:: * Parameter default values:: * The NULL default value:: * Expressions specified as default values:: * Using a return converter:: * Cloning existing functions:: * Calling Python code:: * Using a “self converter”:: * Writing a custom converter:: * Writing a custom return converter:: * METH_O and METH_NOARGS:: * tp_new and tp_init functions:: * Changing and redirecting Clinic’s output:: * The #ifdef trick:: * Using Argument Clinic in Python files::  File: python.info, Node: Symbolic default values, Next: Renaming the C functions and variables generated by Argument Clinic, Up: Advanced Topics 10.15.4.1 Symbolic default values ................................. The default value you provide for a parameter can’t be any arbitrary expression. Currently the following are explicitly supported: * Numeric constants (integer and float) * String constants * ‘True’, ‘False’, and ‘None’ * Simple symbolic constants like ‘sys.maxsize’, which must start with the name of the module In case you’re curious, this is implemented in ‘from_builtin()’ in ‘Lib/inspect.py’. (In the future, this may need to get even more elaborate, to allow full expressions like ‘CONSTANT - 1’.)  File: python.info, Node: Renaming the C functions and variables generated by Argument Clinic, Next: Converting functions using PyArg_UnpackTuple, Prev: Symbolic default values, Up: Advanced Topics 10.15.4.2 Renaming the C functions and variables generated by Argument Clinic ............................................................................. Argument Clinic automatically names the functions it generates for you. Occasionally this may cause a problem, if the generated name collides with the name of an existing C function. There’s an easy solution: override the names used for the C functions. Just add the keyword ‘"as"’ to your function declaration line, followed by the function name you wish to use. Argument Clinic will use that function name for the base (generated) function, then add ‘"_impl"’ to the end and use that for the name of the impl function. For example, if we wanted to rename the C function names generated for ‘pickle.Pickler.dump’, it’d look like this: /*[clinic input] pickle.Pickler.dump as pickler_dumper ... The base function would now be named ‘pickler_dumper()’, and the impl function would now be named ‘pickler_dumper_impl()’. Similarly, you may have a problem where you want to give a parameter a specific Python name, but that name may be inconvenient in C. Argument Clinic allows you to give a parameter different names in Python and in C, using the same ‘"as"’ syntax: /*[clinic input] pickle.Pickler.dump obj: object file as file_obj: object protocol: object = NULL * fix_imports: bool = True Here, the name used in Python (in the signature and the ‘keywords’ array) would be ‘file’, but the C variable would be named ‘file_obj’. You can use this to rename the ‘self’ parameter too!  File: python.info, Node: Converting functions using PyArg_UnpackTuple, Next: Optional Groups, Prev: Renaming the C functions and variables generated by Argument Clinic, Up: Advanced Topics 10.15.4.3 Converting functions using PyArg_UnpackTuple ...................................................... To convert a function parsing its arguments with *note PyArg_UnpackTuple(): e46, simply write out all the arguments, specifying each as an ‘object’. You may specify the ‘type’ argument to cast the type as appropriate. All arguments should be marked positional-only (add a ‘/’ on a line by itself after the last argument). Currently the generated code will use *note PyArg_ParseTuple(): 26a, but this will change soon.  File: python.info, Node: Optional Groups, Next: Using real Argument Clinic converters instead of “legacy converters”, Prev: Converting functions using PyArg_UnpackTuple, Up: Advanced Topics 10.15.4.4 Optional Groups ......................... Some legacy functions have a tricky approach to parsing their arguments: they count the number of positional arguments, then use a ‘switch’ statement to call one of several different *note PyArg_ParseTuple(): 26a. calls depending on how many positional arguments there are. (These functions cannot accept keyword-only arguments.) This approach was used to simulate optional arguments back before *note PyArg_ParseTupleAndKeywords(): 5ca. was created. While functions using this approach can often be converted to use *note PyArg_ParseTupleAndKeywords(): 5ca, optional arguments, and default values, it’s not always possible. Some of these legacy functions have behaviors *note PyArg_ParseTupleAndKeywords(): 5ca. doesn’t directly support. The most obvious example is the builtin function ‘range()’, which has an optional argument on the `left' side of its required argument! Another example is ‘curses.window.addch()’, which has a group of two arguments that must always be specified together. (The arguments are called ‘x’ and ‘y’; if you call the function passing in ‘x’, you must also pass in ‘y’—and if you don’t pass in ‘x’ you may not pass in ‘y’ either.) In any case, the goal of Argument Clinic is to support argument parsing for all existing CPython builtins without changing their semantics. Therefore Argument Clinic supports this alternate approach to parsing, using what are called `optional groups'. Optional groups are groups of arguments that must all be passed in together. They can be to the left or the right of the required arguments. They can `only' be used with positional-only parameters. Note: Optional groups are `only' intended for use when converting functions that make multiple calls to *note PyArg_ParseTuple(): 26a.! Functions that use `any' other approach for parsing arguments should `almost never' be converted to Argument Clinic using optional groups. Functions using optional groups currently cannot have accurate signatures in Python, because Python just doesn’t understand the concept. Please avoid using optional groups wherever possible. To specify an optional group, add a ‘[’ on a line by itself before the parameters you wish to group together, and a ‘]’ on a line by itself after these parameters. As an example, here’s how ‘curses.window.addch’ uses optional groups to make the first two parameters and the last parameter optional: /*[clinic input] curses.window.addch [ x: int X-coordinate. y: int Y-coordinate. ] ch: object Character to add. [ attr: long Attributes for the character. ] / ... Notes: * For every optional group, one additional parameter will be passed into the impl function representing the group. The parameter will be an int named ‘group_{direction}_{number}’, where ‘{direction}’ is either ‘right’ or ‘left’ depending on whether the group is before or after the required parameters, and ‘{number}’ is a monotonically increasing number (starting at 1) indicating how far away the group is from the required parameters. When the impl is called, this parameter will be set to zero if this group was unused, and set to non-zero if this group was used. (By used or unused, I mean whether or not the parameters received arguments in this invocation.) * If there are no required arguments, the optional groups will behave as if they’re to the right of the required arguments. * In the case of ambiguity, the argument parsing code favors parameters on the left (before the required parameters). * Optional groups can only contain positional-only parameters. * Optional groups are `only' intended for legacy code. Please do not use optional groups for new code.  File: python.info, Node: Using real Argument Clinic converters instead of “legacy converters”, Next: Py_buffer, Prev: Optional Groups, Up: Advanced Topics 10.15.4.5 Using real Argument Clinic converters, instead of “legacy converters” ............................................................................... To save time, and to minimize how much you need to learn to achieve your first port to Argument Clinic, the walkthrough above tells you to use “legacy converters”. “Legacy converters” are a convenience, designed explicitly to make porting existing code to Argument Clinic easier. And to be clear, their use is acceptable when porting code for Python 3.4. However, in the long term we probably want all our blocks to use Argument Clinic’s real syntax for converters. Why? A couple reasons: * The proper converters are far easier to read and clearer in their intent. * There are some format units that are unsupported as “legacy converters”, because they require arguments, and the legacy converter syntax doesn’t support specifying arguments. * In the future we may have a new argument parsing library that isn’t restricted to what *note PyArg_ParseTuple(): 26a. supports; this flexibility won’t be available to parameters using legacy converters. Therefore, if you don’t mind a little extra effort, please use the normal converters instead of legacy converters. In a nutshell, the syntax for Argument Clinic (non-legacy) converters looks like a Python function call. However, if there are no explicit arguments to the function (all functions take their default values), you may omit the parentheses. Thus ‘bool’ and ‘bool()’ are exactly the same converters. All arguments to Argument Clinic converters are keyword-only. All Argument Clinic converters accept the following arguments: ‘c_default’ The default value for this parameter when defined in C. Specifically, this will be the initializer for the variable declared in the “parse function”. See *note the section on default values: 3f69. for how to use this. Specified as a string. ‘annotation’ The annotation value for this parameter. Not currently supported, because PEP 8(1) mandates that the Python library may not use annotations. In addition, some converters accept additional arguments. Here is a list of these arguments, along with their meanings: ‘accept’ A set of Python types (and possibly pseudo-types); this restricts the allowable Python argument to values of these types. (This is not a general-purpose facility; as a rule it only supports specific lists of types as shown in the legacy converter table.) To accept ‘None’, add ‘NoneType’ to this set. ‘bitwise’ Only supported for unsigned integers. The native integer value of this Python argument will be written to the parameter without any range checking, even for negative values. ‘converter’ Only supported by the ‘object’ converter. Specifies the name of a *note C “converter function”: 39cd. to use to convert this object to a native type. ‘encoding’ Only supported for strings. Specifies the encoding to use when converting this string from a Python str (Unicode) value into a C ‘char *’ value. ‘subclass_of’ Only supported for the ‘object’ converter. Requires that the Python value be a subclass of a Python type, as expressed in C. ‘type’ Only supported for the ‘object’ and ‘self’ converters. Specifies the C type that will be used to declare the variable. Default value is ‘"PyObject *"’. ‘zeroes’ Only supported for strings. If true, embedded NUL bytes (‘'\\0'’) are permitted inside the value. The length of the string will be passed in to the impl function, just after the string parameter, as a parameter named ‘_length’. Please note, not every possible combination of arguments will work. Usually these arguments are implemented by specific ‘PyArg_ParseTuple’ `format units', with specific behavior. For example, currently you cannot call ‘unsigned_short’ without also specifying ‘bitwise=True’. Although it’s perfectly reasonable to think this would work, these semantics don’t map to any existing format unit. So Argument Clinic doesn’t support it. (Or, at least, not yet.) Below is a table showing the mapping of legacy converters into real Argument Clinic converters. On the left is the legacy converter, on the right is the text you’d replace it with. ‘'B'’ ‘unsigned_char(bitwise=True)’ ‘'b'’ ‘unsigned_char’ ‘'c'’ ‘char’ ‘'C'’ ‘int(accept={str})’ ‘'d'’ ‘double’ ‘'D'’ ‘Py_complex’ ‘'es'’ ‘str(encoding='name_of_encoding')’ ‘'es#'’ ‘str(encoding='name_of_encoding', zeroes=True)’ ‘'et'’ ‘str(encoding='name_of_encoding', accept={bytes, bytearray, str})’ ‘'et#'’ ‘str(encoding='name_of_encoding', accept={bytes, bytearray, str}, zeroes=True)’ ‘'f'’ ‘float’ ‘'h'’ ‘short’ ‘'H'’ ‘unsigned_short(bitwise=True)’ ‘'i'’ ‘int’ ‘'I'’ ‘unsigned_int(bitwise=True)’ ‘'k'’ ‘unsigned_long(bitwise=True)’ ‘'K'’ ‘unsigned_long_long(bitwise=True)’ ‘'l'’ ‘long’ ‘'L'’ ‘long long’ ‘'n'’ ‘Py_ssize_t’ ‘'O'’ ‘object’ ‘'O!'’ ‘object(subclass_of='&PySomething_Type')’ ‘'O&'’ ‘object(converter='name_of_c_function')’ ‘'p'’ ‘bool’ ‘'S'’ ‘PyBytesObject’ ‘'s'’ ‘str’ ‘'s#'’ ‘str(zeroes=True)’ ‘'s*'’ ‘Py_buffer(accept={buffer, str})’ ‘'U'’ ‘unicode’ ‘'u'’ ‘Py_UNICODE’ ‘'u#'’ ‘Py_UNICODE(zeroes=True)’ ‘'w*'’ ‘Py_buffer(accept={rwbuffer})’ ‘'Y'’ ‘PyByteArrayObject’ ‘'y'’ ‘str(accept={bytes})’ ‘'y#'’ ‘str(accept={robuffer}, zeroes=True)’ ‘'y*'’ ‘Py_buffer’ ‘'Z'’ ‘Py_UNICODE(accept={str, NoneType})’ ‘'Z#'’ ‘Py_UNICODE(accept={str, NoneType}, zeroes=True)’ ‘'z'’ ‘str(accept={str, NoneType})’ ‘'z#'’ ‘str(accept={str, NoneType}, zeroes=True)’ ‘'z*'’ ‘Py_buffer(accept={buffer, str, NoneType})’ As an example, here’s our sample ‘pickle.Pickler.dump’ using the proper converter: /*[clinic input] pickle.Pickler.dump obj: object The object to be pickled. / Write a pickled representation of obj to the open file. [clinic start generated code]*/ One advantage of real converters is that they’re more flexible than legacy converters. For example, the ‘unsigned_int’ converter (and all the ‘unsigned_’ converters) can be specified without ‘bitwise=True’. Their default behavior performs range checking on the value, and they won’t accept negative numbers. You just can’t do that with a legacy converter! Argument Clinic will show you all the converters it has available. For each converter it’ll show you all the parameters it accepts, along with the default value for each parameter. Just run ‘Tools/clinic/clinic.py --converters’ to see the full list. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0008  File: python.info, Node: Py_buffer, Next: Advanced converters, Prev: Using real Argument Clinic converters instead of “legacy converters”, Up: Advanced Topics 10.15.4.6 Py_buffer ................... When using the ‘Py_buffer’ converter (or the ‘'s*'’, ‘'w*'’, ‘'*y'’, or ‘'z*'’ legacy converters), you `must' not call *note PyBuffer_Release(): d54. on the provided buffer. Argument Clinic generates code that does it for you (in the parsing function).  File: python.info, Node: Advanced converters, Next: Parameter default values, Prev: Py_buffer, Up: Advanced Topics 10.15.4.7 Advanced converters ............................. Remember those format units you skipped for your first time because they were advanced? Here’s how to handle those too. The trick is, all those format units take arguments—either conversion functions, or types, or strings specifying an encoding. (But “legacy converters” don’t support arguments. That’s why we skipped them for your first function.) The argument you specified to the format unit is now an argument to the converter; this argument is either ‘converter’ (for ‘O&’), ‘subclass_of’ (for ‘O!’), or ‘encoding’ (for all the format units that start with ‘e’). When using ‘subclass_of’, you may also want to use the other custom argument for ‘object()’: ‘type’, which lets you set the type actually used for the parameter. For example, if you want to ensure that the object is a subclass of ‘PyUnicode_Type’, you probably want to use the converter ‘object(type='PyUnicodeObject *', subclass_of='&PyUnicode_Type')’. One possible problem with using Argument Clinic: it takes away some possible flexibility for the format units starting with ‘e’. When writing a ‘PyArg_Parse’ call by hand, you could theoretically decide at runtime what encoding string to pass in to *note PyArg_ParseTuple(): 26a. But now this string must be hard-coded at Argument-Clinic-preprocessing-time. This limitation is deliberate; it made supporting this format unit much easier, and may allow for future optimizations. This restriction doesn’t seem unreasonable; CPython itself always passes in static hard-coded encoding strings for parameters whose format units start with ‘e’.  File: python.info, Node: Parameter default values, Next: The NULL default value, Prev: Advanced converters, Up: Advanced Topics 10.15.4.8 Parameter default values .................................. Default values for parameters can be any of a number of values. At their simplest, they can be string, int, or float literals: foo: str = "abc" bar: int = 123 bat: float = 45.6 They can also use any of Python’s built-in constants: yep: bool = True nope: bool = False nada: object = None There’s also special support for a default value of ‘NULL’, and for simple expressions, documented in the following sections.  File: python.info, Node: The NULL default value, Next: Expressions specified as default values, Prev: Parameter default values, Up: Advanced Topics 10.15.4.9 The ‘NULL’ default value .................................. For string and object parameters, you can set them to ‘None’ to indicate that there’s no default. However, that means the C variable will be initialized to ‘Py_None’. For convenience’s sakes, there’s a special value called ‘NULL’ for just this reason: from Python’s perspective it behaves like a default value of ‘None’, but the C variable is initialized with ‘NULL’.  File: python.info, Node: Expressions specified as default values, Next: Using a return converter, Prev: The NULL default value, Up: Advanced Topics 10.15.4.10 Expressions specified as default values .................................................. The default value for a parameter can be more than just a literal value. It can be an entire expression, using math operators and looking up attributes on objects. However, this support isn’t exactly simple, because of some non-obvious semantics. Consider the following example: foo: Py_ssize_t = sys.maxsize - 1 ‘sys.maxsize’ can have different values on different platforms. Therefore Argument Clinic can’t simply evaluate that expression locally and hard-code it in C. So it stores the default in such a way that it will get evaluated at runtime, when the user asks for the function’s signature. What namespace is available when the expression is evaluated? It’s evaluated in the context of the module the builtin came from. So, if your module has an attribute called “‘max_widgets’”, you may simply use it: foo: Py_ssize_t = max_widgets If the symbol isn’t found in the current module, it fails over to looking in ‘sys.modules’. That’s how it can find ‘sys.maxsize’ for example. (Since you don’t know in advance what modules the user will load into their interpreter, it’s best to restrict yourself to modules that are preloaded by Python itself.) Evaluating default values only at runtime means Argument Clinic can’t compute the correct equivalent C default value. So you need to tell it explicitly. When you use an expression, you must also specify the equivalent expression in C, using the ‘c_default’ parameter to the converter: foo: Py_ssize_t(c_default="PY_SSIZE_T_MAX - 1") = sys.maxsize - 1 Another complication: Argument Clinic can’t know in advance whether or not the expression you supply is valid. It parses it to make sure it looks legal, but it can’t `actually' know. You must be very careful when using expressions to specify values that are guaranteed to be valid at runtime! Finally, because expressions must be representable as static C values, there are many restrictions on legal expressions. Here’s a list of Python features you’re not permitted to use: * Function calls. * Inline if statements (‘3 if foo else 5’). * Automatic sequence unpacking (‘*[1, 2, 3]’). * List/set/dict comprehensions and generator expressions. * Tuple/list/set/dict literals.  File: python.info, Node: Using a return converter, Next: Cloning existing functions, Prev: Expressions specified as default values, Up: Advanced Topics 10.15.4.11 Using a return converter ................................... By default the impl function Argument Clinic generates for you returns ‘PyObject *’. But your C function often computes some C type, then converts it into the ‘PyObject *’ at the last moment. Argument Clinic handles converting your inputs from Python types into native C types—why not have it convert your return value from a native C type into a Python type too? That’s what a “return converter” does. It changes your impl function to return some C type, then adds code to the generated (non-impl) function to handle converting that value into the appropriate ‘PyObject *’. The syntax for return converters is similar to that of parameter converters. You specify the return converter like it was a return annotation on the function itself. Return converters behave much the same as parameter converters; they take arguments, the arguments are all keyword-only, and if you’re not changing any of the default arguments you can omit the parentheses. (If you use both ‘"as"’ `and' a return converter for your function, the ‘"as"’ should come before the return converter.) There’s one additional complication when using return converters: how do you indicate an error has occurred? Normally, a function returns a valid (non-‘NULL’) pointer for success, and ‘NULL’ for failure. But if you use an integer return converter, all integers are valid. How can Argument Clinic detect an error? Its solution: each return converter implicitly looks for a special value that indicates an error. If you return that value, and an error has been set (‘PyErr_Occurred()’ returns a true value), then the generated code will propagate the error. Otherwise it will encode the value you return like normal. Currently Argument Clinic supports only a few return converters: bool int unsigned int long unsigned int size_t Py_ssize_t float double DecodeFSDefault None of these take parameters. For the first three, return -1 to indicate error. For ‘DecodeFSDefault’, the return type is ‘const char *’; return a ‘NULL’ pointer to indicate an error. (There’s also an experimental ‘NoneType’ converter, which lets you return ‘Py_None’ on success or ‘NULL’ on failure, without having to increment the reference count on ‘Py_None’. I’m not sure it adds enough clarity to be worth using.) To see all the return converters Argument Clinic supports, along with their parameters (if any), just run ‘Tools/clinic/clinic.py --converters’ for the full list.  File: python.info, Node: Cloning existing functions, Next: Calling Python code, Prev: Using a return converter, Up: Advanced Topics 10.15.4.12 Cloning existing functions ..................................... If you have a number of functions that look similar, you may be able to use Clinic’s “clone” feature. When you clone an existing function, you reuse: * its parameters, including * their names, * their converters, with all parameters, * their default values, * their per-parameter docstrings, * their `kind' (whether they’re positional only, positional or keyword, or keyword only), and * its return converter. The only thing not copied from the original function is its docstring; the syntax allows you to specify a new docstring. Here’s the syntax for cloning a function: /*[clinic input] module.class.new_function [as c_basename] = module.class.existing_function Docstring for new_function goes here. [clinic start generated code]*/ (The functions can be in different modules or classes. I wrote ‘module.class’ in the sample just to illustrate that you must use the full path to `both' functions.) Sorry, there’s no syntax for partially-cloning a function, or cloning a function then modifying it. Cloning is an all-or nothing proposition. Also, the function you are cloning from must have been previously defined in the current file.  File: python.info, Node: Calling Python code, Next: Using a “self converter”, Prev: Cloning existing functions, Up: Advanced Topics 10.15.4.13 Calling Python code .............................. The rest of the advanced topics require you to write Python code which lives inside your C file and modifies Argument Clinic’s runtime state. This is simple: you simply define a Python block. A Python block uses different delimiter lines than an Argument Clinic function block. It looks like this: /*[python input] # python code goes here [python start generated code]*/ All the code inside the Python block is executed at the time it’s parsed. All text written to stdout inside the block is redirected into the “output” after the block. As an example, here’s a Python block that adds a static integer variable to the C code: /*[python input] print('static int __ignored_unused_variable__ = 0;') [python start generated code]*/ static int __ignored_unused_variable__ = 0; /*[python checksum:...]*/  File: python.info, Node: Using a “self converter”, Next: Writing a custom converter, Prev: Calling Python code, Up: Advanced Topics 10.15.4.14 Using a “self converter” ................................... Argument Clinic automatically adds a “self” parameter for you using a default converter. It automatically sets the ‘type’ of this parameter to the “pointer to an instance” you specified when you declared the type. However, you can override Argument Clinic’s converter and specify one yourself. Just add your own ‘self’ parameter as the first parameter in a block, and ensure that its converter is an instance of ‘self_converter’ or a subclass thereof. What’s the point? This lets you override the type of ‘self’, or give it a different default name. How do you specify the custom type you want to cast ‘self’ to? If you only have one or two functions with the same type for ‘self’, you can directly use Argument Clinic’s existing ‘self’ converter, passing in the type you want to use as the ‘type’ parameter: /*[clinic input] _pickle.Pickler.dump self: self(type="PicklerObject *") obj: object / Write a pickled representation of the given object to the open file. [clinic start generated code]*/ On the other hand, if you have a lot of functions that will use the same type for ‘self’, it’s best to create your own converter, subclassing ‘self_converter’ but overwriting the ‘type’ member: /*[python input] class PicklerObject_converter(self_converter): type = "PicklerObject *" [python start generated code]*/ /*[clinic input] _pickle.Pickler.dump self: PicklerObject obj: object / Write a pickled representation of the given object to the open file. [clinic start generated code]*/  File: python.info, Node: Writing a custom converter, Next: Writing a custom return converter, Prev: Using a “self converter”, Up: Advanced Topics 10.15.4.15 Writing a custom converter ..................................... As we hinted at in the previous section… you can write your own converters! A converter is simply a Python class that inherits from ‘CConverter’. The main purpose of a custom converter is if you have a parameter using the ‘O&’ format unit—parsing this parameter means calling a *note PyArg_ParseTuple(): 26a. “converter function”. Your converter class should be named ‘*something*_converter’. If the name follows this convention, then your converter class will be automatically registered with Argument Clinic; its name will be the name of your class with the ‘_converter’ suffix stripped off. (This is accomplished with a metaclass.) You shouldn’t subclass ‘CConverter.__init__’. Instead, you should write a ‘converter_init()’ function. ‘converter_init()’ always accepts a ‘self’ parameter; after that, all additional parameters `must' be keyword-only. Any arguments passed in to the converter in Argument Clinic will be passed along to your ‘converter_init()’. There are some additional members of ‘CConverter’ you may wish to specify in your subclass. Here’s the current list: ‘type’ The C type to use for this variable. ‘type’ should be a Python string specifying the type, e.g. ‘int’. If this is a pointer type, the type string should end with ‘' *'’. ‘default’ The Python default value for this parameter, as a Python value. Or the magic value ‘unspecified’ if there is no default. ‘py_default’ ‘default’ as it should appear in Python code, as a string. Or ‘None’ if there is no default. ‘c_default’ ‘default’ as it should appear in C code, as a string. Or ‘None’ if there is no default. ‘c_ignored_default’ The default value used to initialize the C variable when there is no default, but not specifying a default may result in an “uninitialized variable” warning. This can easily happen when using option groups—although properly-written code will never actually use this value, the variable does get passed in to the impl, and the C compiler will complain about the “use” of the uninitialized value. This value should always be a non-empty string. ‘converter’ The name of the C converter function, as a string. ‘impl_by_reference’ A boolean value. If true, Argument Clinic will add a ‘&’ in front of the name of the variable when passing it into the impl function. ‘parse_by_reference’ A boolean value. If true, Argument Clinic will add a ‘&’ in front of the name of the variable when passing it into *note PyArg_ParseTuple(): 26a. Here’s the simplest example of a custom converter, from ‘Modules/zlibmodule.c’: /*[python input] class ssize_t_converter(CConverter): type = 'Py_ssize_t' converter = 'ssize_t_converter' [python start generated code]*/ /*[python end generated code: output=da39a3ee5e6b4b0d input=35521e4e733823c7]*/ This block adds a converter to Argument Clinic named ‘ssize_t’. Parameters declared as ‘ssize_t’ will be declared as type ‘Py_ssize_t’, and will be parsed by the ‘'O&'’ format unit, which will call the ‘ssize_t_converter’ converter function. ‘ssize_t’ variables automatically support default values. More sophisticated custom converters can insert custom C code to handle initialization and cleanup. You can see more examples of custom converters in the CPython source tree; grep the C files for the string ‘CConverter’.  File: python.info, Node: Writing a custom return converter, Next: METH_O and METH_NOARGS, Prev: Writing a custom converter, Up: Advanced Topics 10.15.4.16 Writing a custom return converter ............................................ Writing a custom return converter is much like writing a custom converter. Except it’s somewhat simpler, because return converters are themselves much simpler. Return converters must subclass ‘CReturnConverter’. There are no examples yet of custom return converters, because they are not widely used yet. If you wish to write your own return converter, please read ‘Tools/clinic/clinic.py’, specifically the implementation of ‘CReturnConverter’ and all its subclasses.  File: python.info, Node: METH_O and METH_NOARGS, Next: tp_new and tp_init functions, Prev: Writing a custom return converter, Up: Advanced Topics 10.15.4.17 METH_O and METH_NOARGS ................................. To convert a function using ‘METH_O’, make sure the function’s single argument is using the ‘object’ converter, and mark the arguments as positional-only: /*[clinic input] meth_o_sample argument: object / [clinic start generated code]*/ To convert a function using ‘METH_NOARGS’, just don’t specify any arguments. You can still use a self converter, a return converter, and specify a ‘type’ argument to the object converter for ‘METH_O’.  File: python.info, Node: tp_new and tp_init functions, Next: Changing and redirecting Clinic’s output, Prev: METH_O and METH_NOARGS, Up: Advanced Topics 10.15.4.18 tp_new and tp_init functions ....................................... You can convert ‘tp_new’ and ‘tp_init’ functions. Just name them ‘__new__’ or ‘__init__’ as appropriate. Notes: * The function name generated for ‘__new__’ doesn’t end in ‘__new__’ like it would by default. It’s just the name of the class, converted into a valid C identifier. * No ‘PyMethodDef’ ‘#define’ is generated for these functions. * ‘__init__’ functions return ‘int’, not ‘PyObject *’. * Use the docstring as the class docstring. * Although ‘__new__’ and ‘__init__’ functions must always accept both the ‘args’ and ‘kwargs’ objects, when converting you may specify any signature for these functions that you like. (If your function doesn’t support keywords, the parsing function generated will throw an exception if it receives any.)  File: python.info, Node: Changing and redirecting Clinic’s output, Next: The #ifdef trick, Prev: tp_new and tp_init functions, Up: Advanced Topics 10.15.4.19 Changing and redirecting Clinic’s output ................................................... It can be inconvenient to have Clinic’s output interspersed with your conventional hand-edited C code. Luckily, Clinic is configurable: you can buffer up its output for printing later (or earlier!), or write its output to a separate file. You can also add a prefix or suffix to every line of Clinic’s generated output. While changing Clinic’s output in this manner can be a boon to readability, it may result in Clinic code using types before they are defined, or your code attempting to use Clinic-generated code before it is defined. These problems can be easily solved by rearranging the declarations in your file, or moving where Clinic’s generated code goes. (This is why the default behavior of Clinic is to output everything into the current block; while many people consider this hampers readability, it will never require rearranging your code to fix definition-before-use problems.) Let’s start with defining some terminology: `field' A field, in this context, is a subsection of Clinic’s output. For example, the ‘#define’ for the ‘PyMethodDef’ structure is a field, called ‘methoddef_define’. Clinic has seven different fields it can output per function definition: docstring_prototype docstring_definition methoddef_define impl_prototype parser_prototype parser_definition impl_definition All the names are of the form ‘"_"’, where ‘""’ is the semantic object represented (the parsing function, the impl function, the docstring, or the methoddef structure) and ‘""’ represents what kind of statement the field is. Field names that end in ‘"_prototype"’ represent forward declarations of that thing, without the actual body/data of the thing; field names that end in ‘"_definition"’ represent the actual definition of the thing, with the body/data of the thing. (‘"methoddef"’ is special, it’s the only one that ends with ‘"_define"’, representing that it’s a preprocessor #define.) `destination' A destination is a place Clinic can write output to. There are five built-in destinations: ‘block’ The default destination: printed in the output section of the current Clinic block. ‘buffer’ A text buffer where you can save text for later. Text sent here is appended to the end of any existing text. It’s an error to have any text left in the buffer when Clinic finishes processing a file. ‘file’ A separate “clinic file” that will be created automatically by Clinic. The filename chosen for the file is ‘{basename}.clinic{extension}’, where ‘basename’ and ‘extension’ were assigned the output from ‘os.path.splitext()’ run on the current file. (Example: the ‘file’ destination for ‘_pickle.c’ would be written to ‘_pickle.clinic.c’.) `Important: When using a' ‘file’ `destination, you' `must check in' `the generated file!' ‘two-pass’ A buffer like ‘buffer’. However, a two-pass buffer can only be dumped once, and it prints out all text sent to it during all processing, even from Clinic blocks `after' the dumping point. ‘suppress’ The text is suppressed—thrown away. Clinic defines five new directives that let you reconfigure its output. The first new directive is ‘dump’: dump This dumps the current contents of the named destination into the output of the current block, and empties it. This only works with ‘buffer’ and ‘two-pass’ destinations. The second new directive is ‘output’. The most basic form of ‘output’ is like this: output This tells Clinic to output `field' to `destination'. ‘output’ also supports a special meta-destination, called ‘everything’, which tells Clinic to output `all' fields to that `destination'. ‘output’ has a number of other functions: output push output pop output preset ‘output push’ and ‘output pop’ allow you to push and pop configurations on an internal configuration stack, so that you can temporarily modify the output configuration, then easily restore the previous configuration. Simply push before your change to save the current configuration, then pop when you wish to restore the previous configuration. ‘output preset’ sets Clinic’s output to one of several built-in preset configurations, as follows: ‘block’ Clinic’s original starting configuration. Writes everything immediately after the input block. Suppress the ‘parser_prototype’ and ‘docstring_prototype’, write everything else to ‘block’. ‘file’ Designed to write everything to the “clinic file” that it can. You then ‘#include’ this file near the top of your file. You may need to rearrange your file to make this work, though usually this just means creating forward declarations for various ‘typedef’ and ‘PyTypeObject’ definitions. Suppress the ‘parser_prototype’ and ‘docstring_prototype’, write the ‘impl_definition’ to ‘block’, and write everything else to ‘file’. The default filename is ‘"{dirname}/clinic/{basename}.h"’. ‘buffer’ Save up most of the output from Clinic, to be written into your file near the end. For Python files implementing modules or builtin types, it’s recommended that you dump the buffer just above the static structures for your module or builtin type; these are normally very near the end. Using ‘buffer’ may require even more editing than ‘file’, if your file has static ‘PyMethodDef’ arrays defined in the middle of the file. Suppress the ‘parser_prototype’, ‘impl_prototype’, and ‘docstring_prototype’, write the ‘impl_definition’ to ‘block’, and write everything else to ‘file’. ‘two-pass’ Similar to the ‘buffer’ preset, but writes forward declarations to the ‘two-pass’ buffer, and definitions to the ‘buffer’. This is similar to the ‘buffer’ preset, but may require less editing than ‘buffer’. Dump the ‘two-pass’ buffer near the top of your file, and dump the ‘buffer’ near the end just like you would when using the ‘buffer’ preset. Suppresses the ‘impl_prototype’, write the ‘impl_definition’ to ‘block’, write ‘docstring_prototype’, ‘methoddef_define’, and ‘parser_prototype’ to ‘two-pass’, write everything else to ‘buffer’. ‘partial-buffer’ Similar to the ‘buffer’ preset, but writes more things to ‘block’, only writing the really big chunks of generated code to ‘buffer’. This avoids the definition-before-use problem of ‘buffer’ completely, at the small cost of having slightly more stuff in the block’s output. Dump the ‘buffer’ near the end, just like you would when using the ‘buffer’ preset. Suppresses the ‘impl_prototype’, write the ‘docstring_definition’ and ‘parser_definition’ to ‘buffer’, write everything else to ‘block’. The third new directive is ‘destination’: destination [...] This performs an operation on the destination named ‘name’. There are two defined subcommands: ‘new’ and ‘clear’. The ‘new’ subcommand works like this: destination new This creates a new destination with name ‘’ and type ‘’. There are five destination types: ‘suppress’ Throws the text away. ‘block’ Writes the text to the current block. This is what Clinic originally did. ‘buffer’ A simple text buffer, like the “buffer” builtin destination above. ‘file’ A text file. The file destination takes an extra argument, a template to use for building the filename, like so: destination new The template can use three strings internally that will be replaced by bits of the filename: {path} The full path to the file, including directory and full filename. {dirname} The name of the directory the file is in. {basename} Just the name of the file, not including the directory. {basename_root} Basename with the extension clipped off (everything up to but not including the last ‘.’). {basename_extension} The last ‘.’ and everything after it. If the basename does not contain a period, this will be the empty string. If there are no periods in the filename, {basename} and {filename} are the same, and {extension} is empty. “{basename}{extension}” is always exactly the same as “{filename}”.” ‘two-pass’ A two-pass buffer, like the “two-pass” builtin destination above. The ‘clear’ subcommand works like this: destination clear It removes all the accumulated text up to this point in the destination. (I don’t know what you’d need this for, but I thought maybe it’d be useful while someone’s experimenting.) The fourth new directive is ‘set’: set line_prefix "string" set line_suffix "string" ‘set’ lets you set two internal variables in Clinic. ‘line_prefix’ is a string that will be prepended to every line of Clinic’s output; ‘line_suffix’ is a string that will be appended to every line of Clinic’s output. Both of these support two format strings: ‘{block comment start}’ Turns into the string ‘/*’, the start-comment text sequence for C files. ‘{block comment end}’ Turns into the string ‘*/’, the end-comment text sequence for C files. The final new directive is one you shouldn’t need to use directly, called ‘preserve’: preserve This tells Clinic that the current contents of the output should be kept, unmodified. This is used internally by Clinic when dumping output into ‘file’ files; wrapping it in a Clinic block lets Clinic use its existing checksum functionality to ensure the file was not modified by hand before it gets overwritten.  File: python.info, Node: The #ifdef trick, Next: Using Argument Clinic in Python files, Prev: Changing and redirecting Clinic’s output, Up: Advanced Topics 10.15.4.20 The #ifdef trick ........................... If you’re converting a function that isn’t available on all platforms, there’s a trick you can use to make life a little easier. The existing code probably looks like this: #ifdef HAVE_FUNCTIONNAME static module_functionname(...) { ... } #endif /* HAVE_FUNCTIONNAME */ And then in the ‘PyMethodDef’ structure at the bottom the existing code will have: #ifdef HAVE_FUNCTIONNAME {'functionname', ... }, #endif /* HAVE_FUNCTIONNAME */ In this scenario, you should enclose the body of your impl function inside the ‘#ifdef’, like so: #ifdef HAVE_FUNCTIONNAME /*[clinic input] module.functionname ... [clinic start generated code]*/ static module_functionname(...) { ... } #endif /* HAVE_FUNCTIONNAME */ Then, remove those three lines from the ‘PyMethodDef’ structure, replacing them with the macro Argument Clinic generated: MODULE_FUNCTIONNAME_METHODDEF (You can find the real name for this macro inside the generated code. Or you can calculate it yourself: it’s the name of your function as defined on the first line of your block, but with periods changed to underscores, uppercased, and ‘"_METHODDEF"’ added to the end.) Perhaps you’re wondering: what if ‘HAVE_FUNCTIONNAME’ isn’t defined? The ‘MODULE_FUNCTIONNAME_METHODDEF’ macro won’t be defined either! Here’s where Argument Clinic gets very clever. It actually detects that the Argument Clinic block might be deactivated by the ‘#ifdef’. When that happens, it generates a little extra code that looks like this: #ifndef MODULE_FUNCTIONNAME_METHODDEF #define MODULE_FUNCTIONNAME_METHODDEF #endif /* !defined(MODULE_FUNCTIONNAME_METHODDEF) */ That means the macro always works. If the function is defined, this turns into the correct structure, including the trailing comma. If the function is undefined, this turns into nothing. However, this causes one ticklish problem: where should Argument Clinic put this extra code when using the “block” output preset? It can’t go in the output block, because that could be deactivated by the ‘#ifdef’. (That’s the whole point!) In this situation, Argument Clinic writes the extra code to the “buffer” destination. This may mean that you get a complaint from Argument Clinic: Warning in file "Modules/posixmodule.c" on line 12357: Destination buffer 'buffer' not empty at end of file, emptying. When this happens, just open your file, find the ‘dump buffer’ block that Argument Clinic added to your file (it’ll be at the very bottom), then move it above the ‘PyMethodDef’ structure where that macro is used.  File: python.info, Node: Using Argument Clinic in Python files, Prev: The #ifdef trick, Up: Advanced Topics 10.15.4.21 Using Argument Clinic in Python files ................................................ It’s actually possible to use Argument Clinic to preprocess Python files. There’s no point to using Argument Clinic blocks, of course, as the output wouldn’t make any sense to the Python interpreter. But using Argument Clinic to run Python blocks lets you use Python as a Python preprocessor! Since Python comments are different from C comments, Argument Clinic blocks embedded in Python files look slightly different. They look like this: #/*[python input] #print("def foo(): pass") #[python start generated code]*/ def foo(): pass #/*[python checksum:...]*/  File: python.info, Node: Instrumenting CPython with DTrace and SystemTap, Prev: Argument Clinic How-To, Up: Python HOWTOs 10.16 Instrumenting CPython with DTrace and SystemTap ===================================================== author: David Malcolm author: Łukasz Langa DTrace and SystemTap are monitoring tools, each providing a way to inspect what the processes on a computer system are doing. They both use domain-specific languages allowing a user to write scripts which: - filter which processes are to be observed - gather data from the processes of interest - generate reports on the data As of Python 3.6, CPython can be built with embedded “markers”, also known as “probes”, that can be observed by a DTrace or SystemTap script, making it easier to monitor what the CPython processes on a system are doing. `CPython implementation detail:' DTrace markers are implementation details of the CPython interpreter. No guarantees are made about probe compatibility between versions of CPython. DTrace scripts can stop working or work incorrectly without warning when changing CPython versions. * Menu: * Enabling the static markers:: * Static DTrace probes:: * Static SystemTap markers:: * Available static markers:: * SystemTap Tapsets:: * Examples: Examples<36>.  File: python.info, Node: Enabling the static markers, Next: Static DTrace probes, Up: Instrumenting CPython with DTrace and SystemTap 10.16.1 Enabling the static markers ----------------------------------- macOS comes with built-in support for DTrace. On Linux, in order to build CPython with the embedded markers for SystemTap, the SystemTap development tools must be installed. On a Linux machine, this can be done via: $ yum install systemtap-sdt-devel or: $ sudo apt-get install systemtap-sdt-dev CPython must then be configured ‘--with-dtrace’: checking for --with-dtrace... yes On macOS, you can list available DTrace probes by running a Python process in the background and listing all probes made available by the Python provider: $ python3.6 -q & $ sudo dtrace -l -P python$! # or: dtrace -l -m python3.6 ID PROVIDER MODULE FUNCTION NAME 29564 python18035 python3.6 _PyEval_EvalFrameDefault function-entry 29565 python18035 python3.6 dtrace_function_entry function-entry 29566 python18035 python3.6 _PyEval_EvalFrameDefault function-return 29567 python18035 python3.6 dtrace_function_return function-return 29568 python18035 python3.6 collect gc-done 29569 python18035 python3.6 collect gc-start 29570 python18035 python3.6 _PyEval_EvalFrameDefault line 29571 python18035 python3.6 maybe_dtrace_line line On Linux, you can verify if the SystemTap static markers are present in the built binary by seeing if it contains a “.note.stapsdt” section. $ readelf -S ./python | grep .note.stapsdt [30] .note.stapsdt NOTE 0000000000000000 00308d78 If you’ve built Python as a shared library (with –enable-shared), you need to look instead within the shared library. For example: $ readelf -S libpython3.3dm.so.1.0 | grep .note.stapsdt [29] .note.stapsdt NOTE 0000000000000000 00365b68 Sufficiently modern readelf can print the metadata: $ readelf -n ./python Displaying notes found at file offset 0x00000254 with length 0x00000020: Owner Data size Description GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag) OS: Linux, ABI: 2.6.32 Displaying notes found at file offset 0x00000274 with length 0x00000024: Owner Data size Description GNU 0x00000014 NT_GNU_BUILD_ID (unique build ID bitstring) Build ID: df924a2b08a7e89f6e11251d4602022977af2670 Displaying notes found at file offset 0x002d6c30 with length 0x00000144: Owner Data size Description stapsdt 0x00000031 NT_STAPSDT (SystemTap probe descriptors) Provider: python Name: gc__start Location: 0x00000000004371c3, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bf6 Arguments: -4@%ebx stapsdt 0x00000030 NT_STAPSDT (SystemTap probe descriptors) Provider: python Name: gc__done Location: 0x00000000004374e1, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bf8 Arguments: -8@%rax stapsdt 0x00000045 NT_STAPSDT (SystemTap probe descriptors) Provider: python Name: function__entry Location: 0x000000000053db6c, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6be8 Arguments: 8@%rbp 8@%r12 -4@%eax stapsdt 0x00000046 NT_STAPSDT (SystemTap probe descriptors) Provider: python Name: function__return Location: 0x000000000053dba8, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bea Arguments: 8@%rbp 8@%r12 -4@%eax The above metadata contains information for SystemTap describing how it can patch strategically-placed machine code instructions to enable the tracing hooks used by a SystemTap script.  File: python.info, Node: Static DTrace probes, Next: Static SystemTap markers, Prev: Enabling the static markers, Up: Instrumenting CPython with DTrace and SystemTap 10.16.2 Static DTrace probes ---------------------------- The following example DTrace script can be used to show the call/return hierarchy of a Python script, only tracing within the invocation of a function called “start”. In other words, import-time function invocations are not going to be listed: self int indent; python$target:::function-entry /copyinstr(arg1) == "start"/ { self->trace = 1; } python$target:::function-entry /self->trace/ { printf("%d\t%*s:", timestamp, 15, probename); printf("%*s", self->indent, ""); printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2); self->indent++; } python$target:::function-return /self->trace/ { self->indent--; printf("%d\t%*s:", timestamp, 15, probename); printf("%*s", self->indent, ""); printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2); } python$target:::function-return /copyinstr(arg1) == "start"/ { self->trace = 0; } It can be invoked like this: $ sudo dtrace -q -s call_stack.d -c "python3.6 script.py" The output looks like this: 156641360502280 function-entry:call_stack.py:start:23 156641360518804 function-entry: call_stack.py:function_1:1 156641360532797 function-entry: call_stack.py:function_3:9 156641360546807 function-return: call_stack.py:function_3:10 156641360563367 function-return: call_stack.py:function_1:2 156641360578365 function-entry: call_stack.py:function_2:5 156641360591757 function-entry: call_stack.py:function_1:1 156641360605556 function-entry: call_stack.py:function_3:9 156641360617482 function-return: call_stack.py:function_3:10 156641360629814 function-return: call_stack.py:function_1:2 156641360642285 function-return: call_stack.py:function_2:6 156641360656770 function-entry: call_stack.py:function_3:9 156641360669707 function-return: call_stack.py:function_3:10 156641360687853 function-entry: call_stack.py:function_4:13 156641360700719 function-return: call_stack.py:function_4:14 156641360719640 function-entry: call_stack.py:function_5:18 156641360732567 function-return: call_stack.py:function_5:21 156641360747370 function-return:call_stack.py:start:28  File: python.info, Node: Static SystemTap markers, Next: Available static markers, Prev: Static DTrace probes, Up: Instrumenting CPython with DTrace and SystemTap 10.16.3 Static SystemTap markers -------------------------------- The low-level way to use the SystemTap integration is to use the static markers directly. This requires you to explicitly state the binary file containing them. For example, this SystemTap script can be used to show the call/return hierarchy of a Python script: probe process("python").mark("function__entry") { filename = user_string($arg1); funcname = user_string($arg2); lineno = $arg3; printf("%s => %s in %s:%d\\n", thread_indent(1), funcname, filename, lineno); } probe process("python").mark("function__return") { filename = user_string($arg1); funcname = user_string($arg2); lineno = $arg3; printf("%s <= %s in %s:%d\\n", thread_indent(-1), funcname, filename, lineno); } It can be invoked like this: $ stap \ show-call-hierarchy.stp \ -c "./python test.py" The output looks like this: 11408 python(8274): => __contains__ in Lib/_abcoll.py:362 11414 python(8274): => __getitem__ in Lib/os.py:425 11418 python(8274): => encode in Lib/os.py:490 11424 python(8274): <= encode in Lib/os.py:493 11428 python(8274): <= __getitem__ in Lib/os.py:426 11433 python(8274): <= __contains__ in Lib/_abcoll.py:366 where the columns are: - time in microseconds since start of script - name of executable - PID of process and the remainder indicates the call/return hierarchy as the script executes. For a ‘–enable-shared’ build of CPython, the markers are contained within the libpython shared library, and the probe’s dotted path needs to reflect this. For example, this line from the above example: probe process("python").mark("function__entry") { should instead read: probe process("python").library("libpython3.6dm.so.1.0").mark("function__entry") { (assuming a debug build of CPython 3.6)  File: python.info, Node: Available static markers, Next: SystemTap Tapsets, Prev: Static SystemTap markers, Up: Instrumenting CPython with DTrace and SystemTap 10.16.4 Available static markers -------------------------------- -- Object: function__entry(str filename, str funcname, int lineno) This marker indicates that execution of a Python function has begun. It is only triggered for pure-Python (bytecode) functions. The filename, function name, and line number are provided back to the tracing script as positional arguments, which must be accessed using ‘$arg1’, ‘$arg2’, ‘$arg3’: * ‘$arg1’ : ‘(const char *)’ filename, accessible using ‘user_string($arg1)’ * ‘$arg2’ : ‘(const char *)’ function name, accessible using ‘user_string($arg2)’ * ‘$arg3’ : ‘int’ line number -- Object: function__return(str filename, str funcname, int lineno) This marker is the converse of ‘function__entry()’, and indicates that execution of a Python function has ended (either via ‘return’, or via an exception). It is only triggered for pure-Python (bytecode) functions. The arguments are the same as for ‘function__entry()’ -- Object: line(str filename, str funcname, int lineno) This marker indicates a Python line is about to be executed. It is the equivalent of line-by-line tracing with a Python profiler. It is not triggered within C functions. The arguments are the same as for ‘function__entry()’. -- Object: gc__start(int generation) Fires when the Python interpreter starts a garbage collection cycle. ‘arg0’ is the generation to scan, like *note gc.collect(): 22e. -- Object: gc__done(long collected) Fires when the Python interpreter finishes a garbage collection cycle. ‘arg0’ is the number of collected objects. -- Object: import__find__load__start(str modulename) Fires before *note importlib: 9b. attempts to find and load the module. ‘arg0’ is the module name. New in version 3.7. -- Object: import__find__load__done(str modulename, int found) Fires after *note importlib: 9b.’s find_and_load function is called. ‘arg0’ is the module name, ‘arg1’ indicates if module was successfully loaded. New in version 3.7. -- Object: audit(str event, void *tuple) Fires when *note sys.audit(): 31ea. or *note PySys_Audit(): 31eb. is called. ‘arg0’ is the event name as C string, ‘arg1’ is a *note PyObject: 4ba. pointer to a tuple object. New in version 3.8.  File: python.info, Node: SystemTap Tapsets, Next: Examples<36>, Prev: Available static markers, Up: Instrumenting CPython with DTrace and SystemTap 10.16.5 SystemTap Tapsets ------------------------- The higher-level way to use the SystemTap integration is to use a “tapset”: SystemTap’s equivalent of a library, which hides some of the lower-level details of the static markers. Here is a tapset file, based on a non-shared build of CPython: /* Provide a higher-level wrapping around the function__entry and function__return markers: \*/ probe python.function.entry = process("python").mark("function__entry") { filename = user_string($arg1); funcname = user_string($arg2); lineno = $arg3; frameptr = $arg4 } probe python.function.return = process("python").mark("function__return") { filename = user_string($arg1); funcname = user_string($arg2); lineno = $arg3; frameptr = $arg4 } If this file is installed in SystemTap’s tapset directory (e.g. ‘/usr/share/systemtap/tapset’), then these additional probepoints become available: -- Object: python.function.entry(str filename, str funcname, int lineno, frameptr) This probe point indicates that execution of a Python function has begun. It is only triggered for pure-Python (bytecode) functions. -- Object: python.function.return(str filename, str funcname, int lineno, frameptr) This probe point is the converse of ‘python.function.return’, and indicates that execution of a Python function has ended (either via ‘return’, or via an exception). It is only triggered for pure-Python (bytecode) functions.  File: python.info, Node: Examples<36>, Prev: SystemTap Tapsets, Up: Instrumenting CPython with DTrace and SystemTap 10.16.6 Examples ---------------- This SystemTap script uses the tapset above to more cleanly implement the example given above of tracing the Python function-call hierarchy, without needing to directly name the static markers: probe python.function.entry { printf("%s => %s in %s:%d\n", thread_indent(1), funcname, filename, lineno); } probe python.function.return { printf("%s <= %s in %s:%d\n", thread_indent(-1), funcname, filename, lineno); } The following script uses the tapset above to provide a top-like view of all running CPython code, showing the top 20 most frequently-entered bytecode frames, each second, across the whole system: global fn_calls; probe python.function.entry { fn_calls[pid(), filename, funcname, lineno] += 1; } probe timer.ms(1000) { printf("\033[2J\033[1;1H") /* clear screen \*/ printf("%6s %80s %6s %30s %6s\n", "PID", "FILENAME", "LINE", "FUNCTION", "CALLS") foreach ([pid, filename, funcname, lineno] in fn_calls- limit 20) { printf("%6d %80s %6d %30s %6d\n", pid, filename, lineno, funcname, fn_calls[pid, filename, funcname, lineno]); } delete fn_calls; }  File: python.info, Node: Python Frequently Asked Questions, Next: Glossary, Prev: Python HOWTOs, Up: Top 11 Python Frequently Asked Questions ************************************ * Menu: * General Python FAQ:: * Programming FAQ:: * Design and History FAQ:: * Library and Extension FAQ:: * Extending/Embedding FAQ:: * Python on Windows FAQ:: * Graphic User Interface FAQ:: * “Why is Python Installed on my Computer?” FAQ::  File: python.info, Node: General Python FAQ, Next: Programming FAQ, Up: Python Frequently Asked Questions 11.1 General Python FAQ ======================= * Menu: * General Information:: * Python in the real world::  File: python.info, Node: General Information, Next: Python in the real world, Up: General Python FAQ 11.1.1 General Information -------------------------- * Menu: * What is Python?:: * What is the Python Software Foundation?:: * Are there copyright restrictions on the use of Python?:: * Why was Python created in the first place?:: * What is Python good for?:: * How does the Python version numbering scheme work?:: * How do I obtain a copy of the Python source?:: * How do I get documentation on Python?:: * I’ve never programmed before. Is there a Python tutorial?: I’ve never programmed before Is there a Python tutorial?. * Is there a newsgroup or mailing list devoted to Python?:: * How do I get a beta test version of Python?:: * How do I submit bug reports and patches for Python?:: * Are there any published articles about Python that I can reference?:: * Are there any books on Python?:: * Where in the world is www.python.org located?: Where in the world is www python org located?. * Why is it called Python?:: * Do I have to like “Monty Python’s Flying Circus”?::  File: python.info, Node: What is Python?, Next: What is the Python Software Foundation?, Up: General Information 11.1.1.1 What is Python? ........................ Python is an interpreted, interactive, object-oriented programming language. It incorporates modules, exceptions, dynamic typing, very high level dynamic data types, and classes. It supports multiple programming paradigms beyond object-oriented programming, such as procedural and functional programming. Python combines remarkable power with very clear syntax. It has interfaces to many system calls and libraries, as well as to various window systems, and is extensible in C or C++. It is also usable as an extension language for applications that need a programmable interface. Finally, Python is portable: it runs on many Unix variants including Linux and macOS, and on Windows. To find out more, start with *note The Python Tutorial: e8d. The Beginner’s Guide to Python(1) links to other introductory tutorials and resources for learning Python. ---------- Footnotes ---------- (1) https://wiki.python.org/moin/BeginnersGuide  File: python.info, Node: What is the Python Software Foundation?, Next: Are there copyright restrictions on the use of Python?, Prev: What is Python?, Up: General Information 11.1.1.2 What is the Python Software Foundation? ................................................ The Python Software Foundation is an independent non-profit organization that holds the copyright on Python versions 2.1 and newer. The PSF’s mission is to advance open source technology related to the Python programming language and to publicize the use of Python. The PSF’s home page is at ‘https://www.python.org/psf/’. Donations to the PSF are tax-exempt in the US. If you use Python and find it helpful, please contribute via the PSF donation page(1). ---------- Footnotes ---------- (1) https://www.python.org/psf/donations/  File: python.info, Node: Are there copyright restrictions on the use of Python?, Next: Why was Python created in the first place?, Prev: What is the Python Software Foundation?, Up: General Information 11.1.1.3 Are there copyright restrictions on the use of Python? ............................................................... You can do anything you want with the source, as long as you leave the copyrights in and display those copyrights in any documentation about Python that you produce. If you honor the copyright rules, it’s OK to use Python for commercial use, to sell copies of Python in source or binary form (modified or unmodified), or to sell products that incorporate Python in some form. We would still like to know about all commercial use of Python, of course. See the PSF license page(1) to find further explanations and a link to the full text of the license. The Python logo is trademarked, and in certain cases permission is required to use it. Consult the Trademark Usage Policy(2) for more information. ---------- Footnotes ---------- (1) https://www.python.org/psf/license/ (2) https://www.python.org/psf/trademarks/  File: python.info, Node: Why was Python created in the first place?, Next: What is Python good for?, Prev: Are there copyright restrictions on the use of Python?, Up: General Information 11.1.1.4 Why was Python created in the first place? ................................................... Here’s a `very' brief summary of what started it all, written by Guido van Rossum: I had extensive experience with implementing an interpreted language in the ABC group at CWI, and from working with this group I had learned a lot about language design. This is the origin of many Python features, including the use of indentation for statement grouping and the inclusion of very-high-level data types (although the details are all different in Python). I had a number of gripes about the ABC language, but also liked many of its features. It was impossible to extend the ABC language (or its implementation) to remedy my complaints – in fact its lack of extensibility was one of its biggest problems. I had some experience with using Modula-2+ and talked with the designers of Modula-3 and read the Modula-3 report. Modula-3 is the origin of the syntax and semantics used for exceptions, and some other Python features. I was working in the Amoeba distributed operating system group at CWI. We needed a better way to do system administration than by writing either C programs or Bourne shell scripts, since Amoeba had its own system call interface which wasn’t easily accessible from the Bourne shell. My experience with error handling in Amoeba made me acutely aware of the importance of exceptions as a programming language feature. It occurred to me that a scripting language with a syntax like ABC but with access to the Amoeba system calls would fill the need. I realized that it would be foolish to write an Amoeba-specific language, so I decided that I needed a language that was generally extensible. During the 1989 Christmas holidays, I had a lot of time on my hand, so I decided to give it a try. During the next year, while still mostly working on it in my own time, Python was used in the Amoeba project with increasing success, and the feedback from colleagues made me add many early improvements. In February 1991, after just over a year of development, I decided to post to USENET. The rest is in the ‘Misc/HISTORY’ file.  File: python.info, Node: What is Python good for?, Next: How does the Python version numbering scheme work?, Prev: Why was Python created in the first place?, Up: General Information 11.1.1.5 What is Python good for? ................................. Python is a high-level general-purpose programming language that can be applied to many different classes of problems. The language comes with a large standard library that covers areas such as string processing (regular expressions, Unicode, calculating differences between files), Internet protocols (HTTP, FTP, SMTP, XML-RPC, POP, IMAP, CGI programming), software engineering (unit testing, logging, profiling, parsing Python code), and operating system interfaces (system calls, filesystems, TCP/IP sockets). Look at the table of contents for *note The Python Standard Library: e8e. to get an idea of what’s available. A wide variety of third-party extensions are also available. Consult the Python Package Index(1) to find packages of interest to you. ---------- Footnotes ---------- (1) https://pypi.org  File: python.info, Node: How does the Python version numbering scheme work?, Next: How do I obtain a copy of the Python source?, Prev: What is Python good for?, Up: General Information 11.1.1.6 How does the Python version numbering scheme work? ........................................................... Python versions are numbered A.B.C or A.B. A is the major version number – it is only incremented for really major changes in the language. B is the minor version number, incremented for less earth-shattering changes. C is the micro-level – it is incremented for each bugfix release. See PEP 6(1) for more information about bugfix releases. Not all releases are bugfix releases. In the run-up to a new major release, a series of development releases are made, denoted as alpha, beta, or release candidate. Alphas are early releases in which interfaces aren’t yet finalized; it’s not unexpected to see an interface change between two alpha releases. Betas are more stable, preserving existing interfaces but possibly adding new modules, and release candidates are frozen, making no changes except as needed to fix critical bugs. Alpha, beta and release candidate versions have an additional suffix. The suffix for an alpha version is “aN” for some small number N, the suffix for a beta version is “bN” for some small number N, and the suffix for a release candidate version is “cN” for some small number N. In other words, all versions labeled 2.0aN precede the versions labeled 2.0bN, which precede versions labeled 2.0cN, and `those' precede 2.0. You may also find version numbers with a “+” suffix, e.g. “2.2+”. These are unreleased versions, built directly from the CPython development repository. In practice, after a final minor release is made, the version is incremented to the next minor version, which becomes the “a0” version, e.g. “2.4a0”. See also the documentation for *note sys.version: 5d3, *note sys.hexversion: 335d, and *note sys.version_info: b1a. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0006  File: python.info, Node: How do I obtain a copy of the Python source?, Next: How do I get documentation on Python?, Prev: How does the Python version numbering scheme work?, Up: General Information 11.1.1.7 How do I obtain a copy of the Python source? ..................................................... The latest Python source distribution is always available from python.org, at ‘https://www.python.org/downloads/’. The latest development sources can be obtained at ‘https://github.com/python/cpython/’. The source distribution is a gzipped tar file containing the complete C source, Sphinx-formatted documentation, Python library modules, example programs, and several useful pieces of freely distributable software. The source will compile and run out of the box on most UNIX platforms. Consult the Getting Started section of the Python Developer’s Guide(1) for more information on getting the source code and compiling it. ---------- Footnotes ---------- (1) https://devguide.python.org/setup/  File: python.info, Node: How do I get documentation on Python?, Next: I’ve never programmed before Is there a Python tutorial?, Prev: How do I obtain a copy of the Python source?, Up: General Information 11.1.1.8 How do I get documentation on Python? .............................................. The standard documentation for the current stable version of Python is available at ‘https://docs.python.org/3/’. PDF, plain text, and downloadable HTML versions are also available at ‘https://docs.python.org/3/download.html’. The documentation is written in reStructuredText and processed by the Sphinx documentation tool(1). The reStructuredText source for the documentation is part of the Python source distribution. ---------- Footnotes ---------- (1) http://sphinx-doc.org/  File: python.info, Node: I’ve never programmed before Is there a Python tutorial?, Next: Is there a newsgroup or mailing list devoted to Python?, Prev: How do I get documentation on Python?, Up: General Information 11.1.1.9 I’ve never programmed before. Is there a Python tutorial? .................................................................. There are numerous tutorials and books available. The standard documentation includes *note The Python Tutorial: e8d. Consult the Beginner’s Guide(1) to find information for beginning Python programmers, including lists of tutorials. ---------- Footnotes ---------- (1) https://wiki.python.org/moin/BeginnersGuide  File: python.info, Node: Is there a newsgroup or mailing list devoted to Python?, Next: How do I get a beta test version of Python?, Prev: I’ve never programmed before Is there a Python tutorial?, Up: General Information 11.1.1.10 Is there a newsgroup or mailing list devoted to Python? ................................................................. There is a newsgroup, ‘comp.lang.python’, and a mailing list, python-list(1). The newsgroup and mailing list are gatewayed into each other – if you can read news it’s unnecessary to subscribe to the mailing list. ‘comp.lang.python’ is high-traffic, receiving hundreds of postings every day, and Usenet readers are often more able to cope with this volume. Announcements of new software releases and events can be found in comp.lang.python.announce, a low-traffic moderated list that receives about five postings per day. It’s available as the python-announce mailing list(2). More info about other mailing lists and newsgroups can be found at ‘https://www.python.org/community/lists/’. ---------- Footnotes ---------- (1) https://mail.python.org/mailman/listinfo/python-list (2) https://mail.python.org/mailman/listinfo/python-announce-list  File: python.info, Node: How do I get a beta test version of Python?, Next: How do I submit bug reports and patches for Python?, Prev: Is there a newsgroup or mailing list devoted to Python?, Up: General Information 11.1.1.11 How do I get a beta test version of Python? ..................................................... Alpha and beta releases are available from ‘https://www.python.org/downloads/’. All releases are announced on the comp.lang.python and comp.lang.python.announce newsgroups and on the Python home page at ‘https://www.python.org/’; an RSS feed of news is available. You can also access the development version of Python through Git. See The Python Developer’s Guide(1) for details. ---------- Footnotes ---------- (1) https://devguide.python.org/  File: python.info, Node: How do I submit bug reports and patches for Python?, Next: Are there any published articles about Python that I can reference?, Prev: How do I get a beta test version of Python?, Up: General Information 11.1.1.12 How do I submit bug reports and patches for Python? ............................................................. To report a bug or submit a patch, please use the Roundup installation at ‘https://bugs.python.org/’. You must have a Roundup account to report bugs; this makes it possible for us to contact you if we have follow-up questions. It will also enable Roundup to send you updates as we act on your bug. If you had previously used SourceForge to report bugs to Python, you can obtain your Roundup password through Roundup’s password reset procedure(1). For more information on how Python is developed, consult the Python Developer’s Guide(2). ---------- Footnotes ---------- (1) https://bugs.python.org/user?@template=forgotten (2) https://devguide.python.org/  File: python.info, Node: Are there any published articles about Python that I can reference?, Next: Are there any books on Python?, Prev: How do I submit bug reports and patches for Python?, Up: General Information 11.1.1.13 Are there any published articles about Python that I can reference? ............................................................................. It’s probably best to cite your favorite book about Python. The very first article about Python was written in 1991 and is now quite outdated. Guido van Rossum and Jelke de Boer, “Interactively Testing Remote Servers Using the Python Programming Language”, CWI Quarterly, Volume 4, Issue 4 (December 1991), Amsterdam, pp 283–303.  File: python.info, Node: Are there any books on Python?, Next: Where in the world is www python org located?, Prev: Are there any published articles about Python that I can reference?, Up: General Information 11.1.1.14 Are there any books on Python? ........................................ Yes, there are many, and more are being published. See the python.org wiki at ‘https://wiki.python.org/moin/PythonBooks’ for a list. You can also search online bookstores for “Python” and filter out the Monty Python references; or perhaps search for “Python” and “language”.  File: python.info, Node: Where in the world is www python org located?, Next: Why is it called Python?, Prev: Are there any books on Python?, Up: General Information 11.1.1.15 Where in the world is www.python.org located? ....................................................... The Python project’s infrastructure is located all over the world and is managed by the Python Infrastructure Team. Details here(1). ---------- Footnotes ---------- (1) http://infra.psf.io  File: python.info, Node: Why is it called Python?, Next: Do I have to like “Monty Python’s Flying Circus”?, Prev: Where in the world is www python org located?, Up: General Information 11.1.1.16 Why is it called Python? .................................. When he began implementing Python, Guido van Rossum was also reading the published scripts from "Monty Python’s Flying Circus"(1), a BBC comedy series from the 1970s. Van Rossum thought he needed a name that was short, unique, and slightly mysterious, so he decided to call the language Python. ---------- Footnotes ---------- (1) https://en.wikipedia.org/wiki/Monty_Python  File: python.info, Node: Do I have to like “Monty Python’s Flying Circus”?, Prev: Why is it called Python?, Up: General Information 11.1.1.17 Do I have to like “Monty Python’s Flying Circus”? ........................................................... No, but it helps. :)  File: python.info, Node: Python in the real world, Prev: General Information, Up: General Python FAQ 11.1.2 Python in the real world ------------------------------- * Menu: * How stable is Python?:: * How many people are using Python?:: * Have any significant projects been done in Python?:: * What new developments are expected for Python in the future?:: * Is it reasonable to propose incompatible changes to Python?:: * Is Python a good language for beginning programmers?::  File: python.info, Node: How stable is Python?, Next: How many people are using Python?, Up: Python in the real world 11.1.2.1 How stable is Python? .............................. Very stable. New, stable releases have been coming out roughly every 6 to 18 months since 1991, and this seems likely to continue. As of version 3.9, Python will have a major new release every 12 months ( PEP 602(1)). The developers issue “bugfix” releases of older versions, so the stability of existing releases gradually improves. Bugfix releases, indicated by a third component of the version number (e.g. 3.5.3, 3.6.2), are managed for stability; only fixes for known problems are included in a bugfix release, and it’s guaranteed that interfaces will remain the same throughout a series of bugfix releases. The latest stable releases can always be found on the Python download page(2). There are two production-ready versions of Python: 2.x and 3.x. The recommended version is 3.x, which is supported by most widely used libraries. Although 2.x is still widely used, it will not be maintained after January 1, 2020(3). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0602 (2) https://www.python.org/downloads/ (3) https://www.python.org/dev/peps/pep-0373/  File: python.info, Node: How many people are using Python?, Next: Have any significant projects been done in Python?, Prev: How stable is Python?, Up: Python in the real world 11.1.2.2 How many people are using Python? .......................................... There are probably millions of users, though it’s difficult to obtain an exact count. Python is available for free download, so there are no sales figures, and it’s available from many different sites and packaged with many Linux distributions, so download statistics don’t tell the whole story either. The comp.lang.python newsgroup is very active, but not all Python users post to the group or even read it.  File: python.info, Node: Have any significant projects been done in Python?, Next: What new developments are expected for Python in the future?, Prev: How many people are using Python?, Up: Python in the real world 11.1.2.3 Have any significant projects been done in Python? ........................................................... See ‘https://www.python.org/about/success’ for a list of projects that use Python. Consulting the proceedings for past Python conferences(1) will reveal contributions from many different companies and organizations. High-profile Python projects include the Mailman mailing list manager(2) and the Zope application server(3). Several Linux distributions, most notably Red Hat(4), have written part or all of their installer and system administration software in Python. Companies that use Python internally include Google, Yahoo, and Lucasfilm Ltd. ---------- Footnotes ---------- (1) https://www.python.org/community/workshops/ (2) http://www.list.org (3) http://www.zope.org (4) https://www.redhat.com  File: python.info, Node: What new developments are expected for Python in the future?, Next: Is it reasonable to propose incompatible changes to Python?, Prev: Have any significant projects been done in Python?, Up: Python in the real world 11.1.2.4 What new developments are expected for Python in the future? ..................................................................... See ‘https://www.python.org/dev/peps/’ for the Python Enhancement Proposals (PEPs). PEPs are design documents describing a suggested new feature for Python, providing a concise technical specification and a rationale. Look for a PEP titled “Python X.Y Release Schedule”, where X.Y is a version that hasn’t been publicly released yet. New development is discussed on the python-dev mailing list(1). ---------- Footnotes ---------- (1) https://mail.python.org/mailman/listinfo/python-dev/  File: python.info, Node: Is it reasonable to propose incompatible changes to Python?, Next: Is Python a good language for beginning programmers?, Prev: What new developments are expected for Python in the future?, Up: Python in the real world 11.1.2.5 Is it reasonable to propose incompatible changes to Python? .................................................................... In general, no. There are already millions of lines of Python code around the world, so any change in the language that invalidates more than a very small fraction of existing programs has to be frowned upon. Even if you can provide a conversion program, there’s still the problem of updating all documentation; many books have been written about Python, and we don’t want to invalidate them all at a single stroke. Providing a gradual upgrade path is necessary if a feature has to be changed. PEP 5(1) describes the procedure followed for introducing backward-incompatible changes while minimizing disruption for users. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0005  File: python.info, Node: Is Python a good language for beginning programmers?, Prev: Is it reasonable to propose incompatible changes to Python?, Up: Python in the real world 11.1.2.6 Is Python a good language for beginning programmers? ............................................................. Yes. It is still common to start students with a procedural and statically typed language such as Pascal, C, or a subset of C++ or Java. Students may be better served by learning Python as their first language. Python has a very simple and consistent syntax and a large standard library and, most importantly, using Python in a beginning programming course lets students concentrate on important programming skills such as problem decomposition and data type design. With Python, students can be quickly introduced to basic concepts such as loops and procedures. They can probably even work with user-defined objects in their very first course. For a student who has never programmed before, using a statically typed language seems unnatural. It presents additional complexity that the student must master and slows the pace of the course. The students are trying to learn to think like a computer, decompose problems, design consistent interfaces, and encapsulate data. While learning to use a statically typed language is important in the long term, it is not necessarily the best topic to address in the students’ first programming course. Many other aspects of Python make it a good first language. Like Java, Python has a large standard library so that students can be assigned programming projects very early in the course that `do' something. Assignments aren’t restricted to the standard four-function calculator and check balancing programs. By using the standard library, students can gain the satisfaction of working on realistic applications as they learn the fundamentals of programming. Using the standard library also teaches students about code reuse. Third-party modules such as PyGame are also helpful in extending the students’ reach. Python’s interactive interpreter enables students to test language features while they’re programming. They can keep a window with the interpreter running while they enter their program’s source in another window. If they can’t remember the methods for a list, they can do something like this: >>> L = [] >>> dir(L) ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'] >>> [d for d in dir(L) if '__' not in d] ['append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'] >>> help(L.append) Help on built-in function append: append(...) L.append(object) -> None -- append object to end >>> L.append(1) >>> L [1] With the interpreter, documentation is never far from the student as they are programming. There are also good IDEs for Python. IDLE is a cross-platform IDE for Python that is written in Python using Tkinter. PythonWin is a Windows-specific IDE. Emacs users will be happy to know that there is a very good Python mode for Emacs. All of these programming environments provide syntax highlighting, auto-indenting, and access to the interactive interpreter while coding. Consult the Python wiki(1) for a full list of Python editing environments. If you want to discuss Python’s use in education, you may be interested in joining the edu-sig mailing list(2). ---------- Footnotes ---------- (1) https://wiki.python.org/moin/PythonEditors (2) https://www.python.org/community/sigs/current/edu-sig  File: python.info, Node: Programming FAQ, Next: Design and History FAQ, Prev: General Python FAQ, Up: Python Frequently Asked Questions 11.2 Programming FAQ ==================== * Menu: * General Questions:: * Core Language:: * Numbers and strings:: * Performance: Performance<4>. * Sequences (Tuples/Lists): Sequences Tuples/Lists. * Objects:: * Modules: Modules<3>.  File: python.info, Node: General Questions, Next: Core Language, Up: Programming FAQ 11.2.1 General Questions ------------------------ * Menu: * Is there a source code level debugger with breakpoints, single-stepping, etc.?: Is there a source code level debugger with breakpoints single-stepping etc ?. * Are there tools to help find bugs or perform static analysis?:: * How can I create a stand-alone binary from a Python script?:: * Are there coding standards or a style guide for Python programs?::  File: python.info, Node: Is there a source code level debugger with breakpoints single-stepping etc ?, Next: Are there tools to help find bugs or perform static analysis?, Up: General Questions 11.2.1.1 Is there a source code level debugger with breakpoints, single-stepping, etc.? ....................................................................................... Yes. Several debuggers for Python are described below, and the built-in function *note breakpoint(): 2f9. allows you to drop into any of them. The pdb module is a simple but adequate console-mode debugger for Python. It is part of the standard Python library, and is *note documented in the Library Reference Manual: c9. You can also write your own debugger by using the code for pdb as an example. The IDLE interactive development environment, which is part of the standard Python distribution (normally available as Tools/scripts/idle), includes a graphical debugger. PythonWin is a Python IDE that includes a GUI debugger based on pdb. The Pythonwin debugger colors breakpoints and has quite a few cool features such as debugging non-Pythonwin programs. Pythonwin is available as part of the Python for Windows Extensions(1) project and as a part of the ActivePython distribution (see ‘https://www.activestate.com/activepython’). Eric(2) is an IDE built on PyQt and the Scintilla editing component. Pydb is a version of the standard Python debugger pdb, modified for use with DDD (Data Display Debugger), a popular graphical debugger front end. Pydb can be found at ‘http://bashdb.sourceforge.net/pydb/’ and DDD can be found at ‘https://www.gnu.org/software/ddd’. There are a number of commercial Python IDEs that include graphical debuggers. They include: * Wing IDE (‘https://wingware.com/’) * Komodo IDE (‘https://komodoide.com/’) * PyCharm (‘https://www.jetbrains.com/pycharm/’) ---------- Footnotes ---------- (1) https://sourceforge.net/projects/pywin32/ (2) http://eric-ide.python-projects.org/  File: python.info, Node: Are there tools to help find bugs or perform static analysis?, Next: How can I create a stand-alone binary from a Python script?, Prev: Is there a source code level debugger with breakpoints single-stepping etc ?, Up: General Questions 11.2.1.2 Are there tools to help find bugs or perform static analysis? ...................................................................... Yes. Pylint(1) and Pyflakes(2) do basic checking that will help you catch bugs sooner. Static type checkers such as Mypy(3), Pyre(4), and Pytype(5) can check type hints in Python source code. ---------- Footnotes ---------- (1) https://www.pylint.org/ (2) https://github.com/PyCQA/pyflakes (3) http://mypy-lang.org/ (4) https://pyre-check.org/ (5) https://github.com/google/pytype  File: python.info, Node: How can I create a stand-alone binary from a Python script?, Next: Are there coding standards or a style guide for Python programs?, Prev: Are there tools to help find bugs or perform static analysis?, Up: General Questions 11.2.1.3 How can I create a stand-alone binary from a Python script? .................................................................... You don’t need the ability to compile Python to C code if all you want is a stand-alone program that users can download and run without having to install the Python distribution first. There are a number of tools that determine the set of modules required by a program and bind these modules together with a Python binary to produce a single executable. One is to use the freeze tool, which is included in the Python source tree as ‘Tools/freeze’. It converts Python byte code to C arrays; a C compiler you can embed all your modules into a new program, which is then linked with the standard Python modules. It works by scanning your source recursively for import statements (in both forms) and looking for the modules in the standard Python path as well as in the source directory (for built-in modules). It then turns the bytecode for modules written in Python into C code (array initializers that can be turned into code objects using the marshal module) and creates a custom-made config file that only contains those built-in modules which are actually used in the program. It then compiles the generated C code and links it with the rest of the Python interpreter to form a self-contained binary which acts exactly like your script. Obviously, freeze requires a C compiler. There are several other utilities which don’t. One is Thomas Heller’s py2exe (Windows only) at ‘http://www.py2exe.org/’ Another tool is Anthony Tuininga’s cx_Freeze(1). ---------- Footnotes ---------- (1) https://anthony-tuininga.github.io/cx_Freeze/  File: python.info, Node: Are there coding standards or a style guide for Python programs?, Prev: How can I create a stand-alone binary from a Python script?, Up: General Questions 11.2.1.4 Are there coding standards or a style guide for Python programs? ......................................................................... Yes. The coding style required for standard library modules is documented as PEP 8(1). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0008  File: python.info, Node: Core Language, Next: Numbers and strings, Prev: General Questions, Up: Programming FAQ 11.2.2 Core Language -------------------- * Menu: * Why am I getting an UnboundLocalError when the variable has a value?:: * What are the rules for local and global variables in Python?:: * Why do lambdas defined in a loop with different values all return the same result?:: * How do I share global variables across modules?:: * What are the “best practices” for using import in a module?:: * Why are default values shared between objects?:: * How can I pass optional or keyword parameters from one function to another?:: * What is the difference between arguments and parameters?:: * Why did changing list ‘y’ also change list ‘x’?:: * How do I write a function with output parameters (call by reference)?: How do I write a function with output parameters call by reference ?. * How do you make a higher order function in Python?:: * How do I copy an object in Python?:: * How can I find the methods or attributes of an object?:: * How can my code discover the name of an object?:: * What’s up with the comma operator’s precedence?:: * Is there an equivalent of C’s “?;” ternary operator?: Is there an equivalent of C’s “? ” ternary operator?. * Is it possible to write obfuscated one-liners in Python?:: * What does the slash(/) in the parameter list of a function mean?: What does the slash / in the parameter list of a function mean?.  File: python.info, Node: Why am I getting an UnboundLocalError when the variable has a value?, Next: What are the rules for local and global variables in Python?, Up: Core Language 11.2.2.1 Why am I getting an UnboundLocalError when the variable has a value? ............................................................................. It can be a surprise to get the UnboundLocalError in previously working code when it is modified by adding an assignment statement somewhere in the body of a function. This code: >>> x = 10 >>> def bar(): ... print(x) >>> bar() 10 works, but this code: >>> x = 10 >>> def foo(): ... print(x) ... x += 1 results in an UnboundLocalError: >>> foo() Traceback (most recent call last): ... UnboundLocalError: local variable 'x' referenced before assignment This is because when you make an assignment to a variable in a scope, that variable becomes local to that scope and shadows any similarly named variable in the outer scope. Since the last statement in foo assigns a new value to ‘x’, the compiler recognizes it as a local variable. Consequently when the earlier ‘print(x)’ attempts to print the uninitialized local variable and an error results. In the example above you can access the outer scope variable by declaring it global: >>> x = 10 >>> def foobar(): ... global x ... print(x) ... x += 1 >>> foobar() 10 This explicit declaration is required in order to remind you that (unlike the superficially analogous situation with class and instance variables) you are actually modifying the value of the variable in the outer scope: >>> print(x) 11 You can do a similar thing in a nested scope using the *note nonlocal: c3f. keyword: >>> def foo(): ... x = 10 ... def bar(): ... nonlocal x ... print(x) ... x += 1 ... bar() ... print(x) >>> foo() 10 11  File: python.info, Node: What are the rules for local and global variables in Python?, Next: Why do lambdas defined in a loop with different values all return the same result?, Prev: Why am I getting an UnboundLocalError when the variable has a value?, Up: Core Language 11.2.2.2 What are the rules for local and global variables in Python? ..................................................................... In Python, variables that are only referenced inside a function are implicitly global. If a variable is assigned a value anywhere within the function’s body, it’s assumed to be a local unless explicitly declared as global. Though a bit surprising at first, a moment’s consideration explains this. On one hand, requiring *note global: ed8. for assigned variables provides a bar against unintended side-effects. On the other hand, if ‘global’ was required for all global references, you’d be using ‘global’ all the time. You’d have to declare as global every reference to a built-in function or to a component of an imported module. This clutter would defeat the usefulness of the ‘global’ declaration for identifying side-effects.  File: python.info, Node: Why do lambdas defined in a loop with different values all return the same result?, Next: How do I share global variables across modules?, Prev: What are the rules for local and global variables in Python?, Up: Core Language 11.2.2.3 Why do lambdas defined in a loop with different values all return the same result? ........................................................................................... Assume you use a for loop to define a few different lambdas (or even plain functions), e.g.: >>> squares = [] >>> for x in range(5): ... squares.append(lambda: x**2) This gives you a list that contains 5 lambdas that calculate ‘x**2’. You might expect that, when called, they would return, respectively, ‘0’, ‘1’, ‘4’, ‘9’, and ‘16’. However, when you actually try you will see that they all return ‘16’: >>> squares[2]() 16 >>> squares[4]() 16 This happens because ‘x’ is not local to the lambdas, but is defined in the outer scope, and it is accessed when the lambda is called — not when it is defined. At the end of the loop, the value of ‘x’ is ‘4’, so all the functions now return ‘4**2’, i.e. ‘16’. You can also verify this by changing the value of ‘x’ and see how the results of the lambdas change: >>> x = 8 >>> squares[2]() 64 In order to avoid this, you need to save the values in variables local to the lambdas, so that they don’t rely on the value of the global ‘x’: >>> squares = [] >>> for x in range(5): ... squares.append(lambda n=x: n**2) Here, ‘n=x’ creates a new variable ‘n’ local to the lambda and computed when the lambda is defined so that it has the same value that ‘x’ had at that point in the loop. This means that the value of ‘n’ will be ‘0’ in the first lambda, ‘1’ in the second, ‘2’ in the third, and so on. Therefore each lambda will now return the correct result: >>> squares[2]() 4 >>> squares[4]() 16 Note that this behaviour is not peculiar to lambdas, but applies to regular functions too.  File: python.info, Node: How do I share global variables across modules?, Next: What are the “best practices” for using import in a module?, Prev: Why do lambdas defined in a loop with different values all return the same result?, Up: Core Language 11.2.2.4 How do I share global variables across modules? ........................................................ The canonical way to share information across modules within a single program is to create a special module (often called config or cfg). Just import the config module in all modules of your application; the module then becomes available as a global name. Because there is only one instance of each module, any changes made to the module object get reflected everywhere. For example: config.py: x = 0 # Default value of the 'x' configuration setting mod.py: import config config.x = 1 main.py: import config import mod print(config.x) Note that using a module is also the basis for implementing the Singleton design pattern, for the same reason.  File: python.info, Node: What are the “best practices” for using import in a module?, Next: Why are default values shared between objects?, Prev: How do I share global variables across modules?, Up: Core Language 11.2.2.5 What are the “best practices” for using import in a module? .................................................................... In general, don’t use ‘from modulename import *’. Doing so clutters the importer’s namespace, and makes it much harder for linters to detect undefined names. Import modules at the top of a file. Doing so makes it clear what other modules your code requires and avoids questions of whether the module name is in scope. Using one import per line makes it easy to add and delete module imports, but using multiple imports per line uses less screen space. It’s good practice if you import modules in the following order: 1. standard library modules – e.g. ‘sys’, ‘os’, ‘getopt’, ‘re’ 2. third-party library modules (anything installed in Python’s site-packages directory) – e.g. mx.DateTime, ZODB, PIL.Image, etc. 3. locally-developed modules It is sometimes necessary to move imports to a function or class to avoid problems with circular imports. Gordon McMillan says: Circular imports are fine where both modules use the “import ” form of import. They fail when the 2nd module wants to grab a name out of the first (“from module import name”) and the import is at the top level. That’s because names in the 1st are not yet available, because the first module is busy importing the 2nd. In this case, if the second module is only used in one function, then the import can easily be moved into that function. By the time the import is called, the first module will have finished initializing, and the second module can do its import. It may also be necessary to move imports out of the top level of code if some of the modules are platform-specific. In that case, it may not even be possible to import all of the modules at the top of the file. In this case, importing the correct modules in the corresponding platform-specific code is a good option. Only move imports into a local scope, such as inside a function definition, if it’s necessary to solve a problem such as avoiding a circular import or are trying to reduce the initialization time of a module. This technique is especially helpful if many of the imports are unnecessary depending on how the program executes. You may also want to move imports into a function if the modules are only ever used in that function. Note that loading a module the first time may be expensive because of the one time initialization of the module, but loading a module multiple times is virtually free, costing only a couple of dictionary lookups. Even if the module name has gone out of scope, the module is probably available in *note sys.modules: 1152.  File: python.info, Node: Why are default values shared between objects?, Next: How can I pass optional or keyword parameters from one function to another?, Prev: What are the “best practices” for using import in a module?, Up: Core Language 11.2.2.6 Why are default values shared between objects? ....................................................... This type of bug commonly bites neophyte programmers. Consider this function: def foo(mydict={}): # Danger: shared reference to one dict for all calls ... compute something ... mydict[key] = value return mydict The first time you call this function, ‘mydict’ contains a single item. The second time, ‘mydict’ contains two items because when ‘foo()’ begins executing, ‘mydict’ starts out with an item already in it. It is often expected that a function call creates new objects for default values. This is not what happens. Default values are created exactly once, when the function is defined. If that object is changed, like the dictionary in this example, subsequent calls to the function will refer to this changed object. By definition, immutable objects such as numbers, strings, tuples, and ‘None’, are safe from change. Changes to mutable objects such as dictionaries, lists, and class instances can lead to confusion. Because of this feature, it is good programming practice to not use mutable objects as default values. Instead, use ‘None’ as the default value and inside the function, check if the parameter is ‘None’ and create a new list/dictionary/whatever if it is. For example, don’t write: def foo(mydict={}): ... but: def foo(mydict=None): if mydict is None: mydict = {} # create a new dict for local namespace This feature can be useful. When you have a function that’s time-consuming to compute, a common technique is to cache the parameters and the resulting value of each call to the function, and return the cached value if the same value is requested again. This is called “memoizing”, and can be implemented like this: # Callers can only provide two parameters and optionally pass _cache by keyword def expensive(arg1, arg2, *, _cache={}): if (arg1, arg2) in _cache: return _cache[(arg1, arg2)] # Calculate the value result = ... expensive computation ... _cache[(arg1, arg2)] = result # Store result in the cache return result You could use a global variable containing a dictionary instead of the default value; it’s a matter of taste.  File: python.info, Node: How can I pass optional or keyword parameters from one function to another?, Next: What is the difference between arguments and parameters?, Prev: Why are default values shared between objects?, Up: Core Language 11.2.2.7 How can I pass optional or keyword parameters from one function to another? .................................................................................... Collect the arguments using the ‘*’ and ‘**’ specifiers in the function’s parameter list; this gives you the positional arguments as a tuple and the keyword arguments as a dictionary. You can then pass these arguments when calling another function by using ‘*’ and ‘**’: def f(x, *args, **kwargs): ... kwargs['width'] = '14.3c' ... g(x, *args, **kwargs)  File: python.info, Node: What is the difference between arguments and parameters?, Next: Why did changing list ‘y’ also change list ‘x’?, Prev: How can I pass optional or keyword parameters from one function to another?, Up: Core Language 11.2.2.8 What is the difference between arguments and parameters? ................................................................. *note Parameters: 11d2. are defined by the names that appear in a function definition, whereas *note arguments: 11ca. are the values actually passed to a function when calling it. Parameters define what types of arguments a function can accept. For example, given the function definition: def func(foo, bar=None, **kwargs): pass `foo', `bar' and `kwargs' are parameters of ‘func’. However, when calling ‘func’, for example: func(42, bar=314, extra=somevar) the values ‘42’, ‘314’, and ‘somevar’ are arguments.  File: python.info, Node: Why did changing list ‘y’ also change list ‘x’?, Next: How do I write a function with output parameters call by reference ?, Prev: What is the difference between arguments and parameters?, Up: Core Language 11.2.2.9 Why did changing list ‘y’ also change list ‘x’? ........................................................ If you wrote code like: >>> x = [] >>> y = x >>> y.append(10) >>> y [10] >>> x [10] you might be wondering why appending an element to ‘y’ changed ‘x’ too. There are two factors that produce this result: 1. Variables are simply names that refer to objects. Doing ‘y = x’ doesn’t create a copy of the list – it creates a new variable ‘y’ that refers to the same object ‘x’ refers to. This means that there is only one object (the list), and both ‘x’ and ‘y’ refer to it. 2. Lists are *note mutable: ebe, which means that you can change their content. After the call to ‘append()’, the content of the mutable object has changed from ‘[]’ to ‘[10]’. Since both the variables refer to the same object, using either name accesses the modified value ‘[10]’. If we instead assign an immutable object to ‘x’: >>> x = 5 # ints are immutable >>> y = x >>> x = x + 1 # 5 can't be mutated, we are creating a new object here >>> x 6 >>> y 5 we can see that in this case ‘x’ and ‘y’ are not equal anymore. This is because integers are *note immutable: eb6, and when we do ‘x = x + 1’ we are not mutating the int ‘5’ by incrementing its value; instead, we are creating a new object (the int ‘6’) and assigning it to ‘x’ (that is, changing which object ‘x’ refers to). After this assignment we have two objects (the ints ‘6’ and ‘5’) and two variables that refer to them (‘x’ now refers to ‘6’ but ‘y’ still refers to ‘5’). Some operations (for example ‘y.append(10)’ and ‘y.sort()’) mutate the object, whereas superficially similar operations (for example ‘y = y + [10]’ and ‘sorted(y)’) create a new object. In general in Python (and in all cases in the standard library) a method that mutates an object will return ‘None’ to help avoid getting the two types of operations confused. So if you mistakenly write ‘y.sort()’ thinking it will give you a sorted copy of ‘y’, you’ll instead end up with ‘None’, which will likely cause your program to generate an easily diagnosed error. However, there is one class of operations where the same operation sometimes has different behaviors with different types: the augmented assignment operators. For example, ‘+=’ mutates lists but not tuples or ints (‘a_list += [1, 2, 3]’ is equivalent to ‘a_list.extend([1, 2, 3])’ and mutates ‘a_list’, whereas ‘some_tuple += (1, 2, 3)’ and ‘some_int += 1’ create new objects). In other words: * If we have a mutable object (*note list: 262, *note dict: 1b8, *note set: b6f, etc.), we can use some specific operations to mutate it and all the variables that refer to it will see the change. * If we have an immutable object (*note str: 330, *note int: 184, *note tuple: 47e, etc.), all the variables that refer to it will always see the same value, but operations that transform that value into a new value always return a new object. If you want to know if two variables refer to the same object or not, you can use the *note is: 10be. operator, or the built-in function *note id(): d86.  File: python.info, Node: How do I write a function with output parameters call by reference ?, Next: How do you make a higher order function in Python?, Prev: Why did changing list ‘y’ also change list ‘x’?, Up: Core Language 11.2.2.10 How do I write a function with output parameters (call by reference)? ............................................................................... Remember that arguments are passed by assignment in Python. Since assignment just creates references to objects, there’s no alias between an argument name in the caller and callee, and so no call-by-reference per se. You can achieve the desired effect in a number of ways. 1. By returning a tuple of the results: >>> def func1(a, b): ... a = 'new-value' # a and b are local names ... b = b + 1 # assigned to new objects ... return a, b # return new values ... >>> x, y = 'old-value', 99 >>> func1(x, y) ('new-value', 100) This is almost always the clearest solution. 2. By using global variables. This isn’t thread-safe, and is not recommended. 3. By passing a mutable (changeable in-place) object: >>> def func2(a): ... a[0] = 'new-value' # 'a' references a mutable list ... a[1] = a[1] + 1 # changes a shared object ... >>> args = ['old-value', 99] >>> func2(args) >>> args ['new-value', 100] 4. By passing in a dictionary that gets mutated: >>> def func3(args): ... args['a'] = 'new-value' # args is a mutable dictionary ... args['b'] = args['b'] + 1 # change it in-place ... >>> args = {'a': 'old-value', 'b': 99} >>> func3(args) >>> args {'a': 'new-value', 'b': 100} 5. Or bundle up values in a class instance: >>> class Namespace: ... def __init__(self, /, **args): ... for key, value in args.items(): ... setattr(self, key, value) ... >>> def func4(args): ... args.a = 'new-value' # args is a mutable Namespace ... args.b = args.b + 1 # change object in-place ... >>> args = Namespace(a='old-value', b=99) >>> func4(args) >>> vars(args) {'a': 'new-value', 'b': 100} There’s almost never a good reason to get this complicated. Your best choice is to return a tuple containing the multiple results.  File: python.info, Node: How do you make a higher order function in Python?, Next: How do I copy an object in Python?, Prev: How do I write a function with output parameters call by reference ?, Up: Core Language 11.2.2.11 How do you make a higher order function in Python? ............................................................ You have two choices: you can use nested scopes or you can use callable objects. For example, suppose you wanted to define ‘linear(a,b)’ which returns a function ‘f(x)’ that computes the value ‘a*x+b’. Using nested scopes: def linear(a, b): def result(x): return a * x + b return result Or using a callable object: class linear: def __init__(self, a, b): self.a, self.b = a, b def __call__(self, x): return self.a * x + self.b In both cases, taxes = linear(0.3, 2) gives a callable object where ‘taxes(10e6) == 0.3 * 10e6 + 2’. The callable object approach has the disadvantage that it is a bit slower and results in slightly longer code. However, note that a collection of callables can share their signature via inheritance: class exponential(linear): # __init__ inherited def __call__(self, x): return self.a * (x ** self.b) Object can encapsulate state for several methods: class counter: value = 0 def set(self, x): self.value = x def up(self): self.value = self.value + 1 def down(self): self.value = self.value - 1 count = counter() inc, dec, reset = count.up, count.down, count.set Here ‘inc()’, ‘dec()’ and ‘reset()’ act like functions which share the same counting variable.  File: python.info, Node: How do I copy an object in Python?, Next: How can I find the methods or attributes of an object?, Prev: How do you make a higher order function in Python?, Up: Core Language 11.2.2.12 How do I copy an object in Python? ............................................ In general, try *note copy.copy(): 3cb. or *note copy.deepcopy(): 3cc. for the general case. Not all objects can be copied, but most can. Some objects can be copied more easily. Dictionaries have a *note copy(): 446. method: newdict = olddict.copy() Sequences can be copied by slicing: new_l = l[:]  File: python.info, Node: How can I find the methods or attributes of an object?, Next: How can my code discover the name of an object?, Prev: How do I copy an object in Python?, Up: Core Language 11.2.2.13 How can I find the methods or attributes of an object? ................................................................ For an instance x of a user-defined class, ‘dir(x)’ returns an alphabetized list of the names containing the instance attributes and methods and attributes defined by its class.  File: python.info, Node: How can my code discover the name of an object?, Next: What’s up with the comma operator’s precedence?, Prev: How can I find the methods or attributes of an object?, Up: Core Language 11.2.2.14 How can my code discover the name of an object? ......................................................... Generally speaking, it can’t, because objects don’t really have names. Essentially, assignment always binds a name to a value; the same is true of ‘def’ and ‘class’ statements, but in that case the value is a callable. Consider the following code: >>> class A: ... pass ... >>> B = A >>> a = B() >>> b = a >>> print(b) <__main__.A object at 0x16D07CC> >>> print(a) <__main__.A object at 0x16D07CC> Arguably the class has a name: even though it is bound to two names and invoked through the name B the created instance is still reported as an instance of class A. However, it is impossible to say whether the instance’s name is a or b, since both names are bound to the same value. Generally speaking it should not be necessary for your code to “know the names” of particular values. Unless you are deliberately writing introspective programs, this is usually an indication that a change of approach might be beneficial. In comp.lang.python, Fredrik Lundh once gave an excellent analogy in answer to this question: The same way as you get the name of that cat you found on your porch: the cat (object) itself cannot tell you its name, and it doesn’t really care – so the only way to find out what it’s called is to ask all your neighbours (namespaces) if it’s their cat (object)… ….and don’t be surprised if you’ll find that it’s known by many names, or no name at all!  File: python.info, Node: What’s up with the comma operator’s precedence?, Next: Is there an equivalent of C’s “? ” ternary operator?, Prev: How can my code discover the name of an object?, Up: Core Language 11.2.2.15 What’s up with the comma operator’s precedence? ......................................................... Comma is not an operator in Python. Consider this session: >>> "a" in "b", "a" (False, 'a') Since the comma is not an operator, but a separator between expressions the above is evaluated as if you had entered: ("a" in "b"), "a" not: "a" in ("b", "a") The same is true of the various assignment operators (‘=’, ‘+=’ etc). They are not truly operators but syntactic delimiters in assignment statements.  File: python.info, Node: Is there an equivalent of C’s “? ” ternary operator?, Next: Is it possible to write obfuscated one-liners in Python?, Prev: What’s up with the comma operator’s precedence?, Up: Core Language 11.2.2.16 Is there an equivalent of C’s “?:” ternary operator? .............................................................. Yes, there is. The syntax is as follows: [on_true] if [expression] else [on_false] x, y = 50, 25 small = x if x < y else y Before this syntax was introduced in Python 2.5, a common idiom was to use logical operators: [expression] and [on_true] or [on_false] However, this idiom is unsafe, as it can give wrong results when `on_true' has a false boolean value. Therefore, it is always better to use the ‘... if ... else ...’ form.  File: python.info, Node: Is it possible to write obfuscated one-liners in Python?, Next: What does the slash / in the parameter list of a function mean?, Prev: Is there an equivalent of C’s “? ” ternary operator?, Up: Core Language 11.2.2.17 Is it possible to write obfuscated one-liners in Python? .................................................................. Yes. Usually this is done by nesting *note lambda: c2f. within ‘lambda’. See the following three examples, due to Ulf Bartelt: from functools import reduce # Primes < 1000 print(list(filter(None,map(lambda y:y*reduce(lambda x,y:x*y!=0, map(lambda x,y=y:y%x,range(2,int(pow(y,0.5)+1))),1),range(2,1000))))) # First 10 Fibonacci numbers print(list(map(lambda x,f=lambda x,f:(f(x-1,f)+f(x-2,f)) if x>1 else 1: f(x,f), range(10)))) # Mandelbrot set print((lambda Ru,Ro,Iu,Io,IM,Sx,Sy:reduce(lambda x,y:x+y,map(lambda y, Iu=Iu,Io=Io,Ru=Ru,Ro=Ro,Sy=Sy,L=lambda yc,Iu=Iu,Io=Io,Ru=Ru,Ro=Ro,i=IM, Sx=Sx,Sy=Sy:reduce(lambda x,y:x+y,map(lambda x,xc=Ru,yc=yc,Ru=Ru,Ro=Ro, i=i,Sx=Sx,F=lambda xc,yc,x,y,k,f=lambda xc,yc,x,y,k,f:(k<=0)or (x*x+y*y >=4.0) or 1+f(xc,yc,x*x-y*y+xc,2.0*x*y+yc,k-1,f):f(xc,yc,x,y,k,f):chr( 64+F(Ru+x*(Ro-Ru)/Sx,yc,0,0,i)),range(Sx))):L(Iu+y*(Io-Iu)/Sy),range(Sy ))))(-2.1, 0.7, -1.2, 1.2, 30, 80, 24)) # \___ ___/ \___ ___/ | | |__ lines on screen # V V | |______ columns on screen # | | |__________ maximum of "iterations" # | |_________________ range on y axis # |____________________________ range on x axis Don’t try this at home, kids!  File: python.info, Node: What does the slash / in the parameter list of a function mean?, Prev: Is it possible to write obfuscated one-liners in Python?, Up: Core Language 11.2.2.18 What does the slash(/) in the parameter list of a function mean? .......................................................................... A slash in the argument list of a function denotes that the parameters prior to it are positional-only. Positional-only parameters are the ones without an externally-usable name. Upon calling a function that accepts positional-only parameters, arguments are mapped to parameters based solely on their position. For example, *note divmod(): 152. is a function that accepts positional-only parameters. Its documentation looks like this: >>> help(divmod) Help on built-in function divmod in module builtins: divmod(x, y, /) Return the tuple (x//y, x%y). Invariant: div*y + mod == x. The slash at the end of the parameter list means that both parameters are positional-only. Thus, calling *note divmod(): 152. with keyword arguments would lead to an error: >>> divmod(x=3, y=4) Traceback (most recent call last): File "", line 1, in TypeError: divmod() takes no keyword arguments  File: python.info, Node: Numbers and strings, Next: Performance<4>, Prev: Core Language, Up: Programming FAQ 11.2.3 Numbers and strings -------------------------- * Menu: * How do I specify hexadecimal and octal integers?:: * Why does -22 // 10 return -3?:: * How do I convert a string to a number?:: * How do I convert a number to a string?:: * How do I modify a string in place?:: * How do I use strings to call functions/methods?:: * Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings?: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?. * Is there a scanf() or sscanf() equivalent?: Is there a scanf or sscanf equivalent?. * What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?::  File: python.info, Node: How do I specify hexadecimal and octal integers?, Next: Why does -22 // 10 return -3?, Up: Numbers and strings 11.2.3.1 How do I specify hexadecimal and octal integers? ......................................................... To specify an octal digit, precede the octal value with a zero, and then a lower or uppercase “o”. For example, to set the variable “a” to the octal value “10” (8 in decimal), type: >>> a = 0o10 >>> a 8 Hexadecimal is just as easy. Simply precede the hexadecimal number with a zero, and then a lower or uppercase “x”. Hexadecimal digits can be specified in lower or uppercase. For example, in the Python interpreter: >>> a = 0xa5 >>> a 165 >>> b = 0XB2 >>> b 178  File: python.info, Node: Why does -22 // 10 return -3?, Next: How do I convert a string to a number?, Prev: How do I specify hexadecimal and octal integers?, Up: Numbers and strings 11.2.3.2 Why does -22 // 10 return -3? ...................................... It’s primarily driven by the desire that ‘i % j’ have the same sign as ‘j’. If you want that, and also want: i == (i // j) * j + (i % j) then integer division has to return the floor. C also requires that identity to hold, and then compilers that truncate ‘i // j’ need to make ‘i % j’ have the same sign as ‘i’. There are few real use cases for ‘i % j’ when ‘j’ is negative. When ‘j’ is positive, there are many, and in virtually all of them it’s more useful for ‘i % j’ to be ‘>= 0’. If the clock says 10 now, what did it say 200 hours ago? ‘-190 % 12 == 2’ is useful; ‘-190 % 12 == -10’ is a bug waiting to bite.  File: python.info, Node: How do I convert a string to a number?, Next: How do I convert a number to a string?, Prev: Why does -22 // 10 return -3?, Up: Numbers and strings 11.2.3.3 How do I convert a string to a number? ............................................... For integers, use the built-in *note int(): 184. type constructor, e.g. ‘int('144') == 144’. Similarly, *note float(): 187. converts to floating-point, e.g. ‘float('144') == 144.0’. By default, these interpret the number as decimal, so that ‘int('0144') == 144’ and ‘int('0x144')’ raises *note ValueError: 1fb. ‘int(string, base)’ takes the base to convert from as a second optional argument, so ‘int('0x144', 16) == 324’. If the base is specified as 0, the number is interpreted using Python’s rules: a leading ‘0o’ indicates octal, and ‘0x’ indicates a hex number. Do not use the built-in function *note eval(): b90. if all you need is to convert strings to numbers. *note eval(): b90. will be significantly slower and it presents a security risk: someone could pass you a Python expression that might have unwanted side effects. For example, someone could pass ‘__import__('os').system("rm -rf $HOME")’ which would erase your home directory. *note eval(): b90. also has the effect of interpreting numbers as Python expressions, so that e.g. ‘eval('09')’ gives a syntax error because Python does not allow leading ‘0’ in a decimal number (except ‘0’).  File: python.info, Node: How do I convert a number to a string?, Next: How do I modify a string in place?, Prev: How do I convert a string to a number?, Up: Numbers and strings 11.2.3.4 How do I convert a number to a string? ............................................... To convert, e.g., the number 144 to the string ‘144’, use the built-in type constructor *note str(): 330. If you want a hexadecimal or octal representation, use the built-in functions *note hex(): c66. or *note oct(): c65. For fancy formatting, see the *note Formatted string literals: 15c. and *note Format String Syntax: d1a. sections, e.g. ‘"{:04d}".format(144)’ yields ‘'0144'’ and ‘"{:.3f}".format(1.0/3.0)’ yields ‘'0.333'’.  File: python.info, Node: How do I modify a string in place?, Next: How do I use strings to call functions/methods?, Prev: How do I convert a number to a string?, Up: Numbers and strings 11.2.3.5 How do I modify a string in place? ........................................... You can’t, because strings are immutable. In most situations, you should simply construct a new string from the various parts you want to assemble it from. However, if you need an object with the ability to modify in-place unicode data, try using an *note io.StringIO: 82d. object or the *note array: 7. module: >>> import io >>> s = "Hello, world" >>> sio = io.StringIO(s) >>> sio.getvalue() 'Hello, world' >>> sio.seek(7) 7 >>> sio.write("there!") 6 >>> sio.getvalue() 'Hello, there!' >>> import array >>> a = array.array('u', s) >>> print(a) array('u', 'Hello, world') >>> a[0] = 'y' >>> print(a) array('u', 'yello, world') >>> a.tounicode() 'yello, world'  File: python.info, Node: How do I use strings to call functions/methods?, Next: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?, Prev: How do I modify a string in place?, Up: Numbers and strings 11.2.3.6 How do I use strings to call functions/methods? ........................................................ There are various techniques. * The best is to use a dictionary that maps strings to functions. The primary advantage of this technique is that the strings do not need to match the names of the functions. This is also the primary technique used to emulate a case construct: def a(): pass def b(): pass dispatch = {'go': a, 'stop': b} # Note lack of parens for funcs dispatch[get_input()]() # Note trailing parens to call function * Use the built-in function *note getattr(): 448.: import foo getattr(foo, 'bar')() Note that *note getattr(): 448. works on any object, including classes, class instances, modules, and so on. This is used in several places in the standard library, like this: class Foo: def do_foo(self): ... def do_bar(self): ... f = getattr(foo_instance, 'do_' + opname) f() * Use *note locals(): 455. or *note eval(): b90. to resolve the function name: def myFunc(): print("hello") fname = "myFunc" f = locals()[fname] f() f = eval(fname) f() Note: Using *note eval(): b90. is slow and dangerous. If you don’t have absolute control over the contents of the string, someone could pass a string that resulted in an arbitrary function being executed.  File: python.info, Node: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?, Next: Is there a scanf or sscanf equivalent?, Prev: How do I use strings to call functions/methods?, Up: Numbers and strings 11.2.3.7 Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings? .............................................................................................. You can use ‘S.rstrip("\r\n")’ to remove all occurrences of any line terminator from the end of the string ‘S’ without removing other trailing whitespace. If the string ‘S’ represents more than one line, with several empty lines at the end, the line terminators for all the blank lines will be removed: >>> lines = ("line 1 \r\n" ... "\r\n" ... "\r\n") >>> lines.rstrip("\n\r") 'line 1 ' Since this is typically only desired when reading text one line at a time, using ‘S.rstrip()’ this way works well.  File: python.info, Node: Is there a scanf or sscanf equivalent?, Next: What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?, Prev: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?, Up: Numbers and strings 11.2.3.8 Is there a scanf() or sscanf() equivalent? ................................................... Not as such. For simple input parsing, the easiest approach is usually to split the line into whitespace-delimited words using the *note split(): 7a1. method of string objects and then convert decimal strings to numeric values using *note int(): 184. or *note float(): 187. ‘split()’ supports an optional “sep” parameter which is useful if the line uses something other than whitespace as a separator. For more complicated input parsing, regular expressions are more powerful than C’s ‘sscanf()’ and better suited for the task.  File: python.info, Node: What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?, Prev: Is there a scanf or sscanf equivalent?, Up: Numbers and strings 11.2.3.9 What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean? ........................................................................... See the *note Unicode HOWTO: c3c.  File: python.info, Node: Performance<4>, Next: Sequences Tuples/Lists, Prev: Numbers and strings, Up: Programming FAQ 11.2.4 Performance ------------------ * Menu: * My program is too slow. How do I speed it up?: My program is too slow How do I speed it up?. * What is the most efficient way to concatenate many strings together?::  File: python.info, Node: My program is too slow How do I speed it up?, Next: What is the most efficient way to concatenate many strings together?, Up: Performance<4> 11.2.4.1 My program is too slow. How do I speed it up? ...................................................... That’s a tough one, in general. First, here are a list of things to remember before diving further: * Performance characteristics vary across Python implementations. This FAQ focuses on *note CPython: 10d7. * Behaviour can vary across operating systems, especially when talking about I/O or multi-threading. * You should always find the hot spots in your program `before' attempting to optimize any code (see the *note profile: d3. module). * Writing benchmark scripts will allow you to iterate quickly when searching for improvements (see the *note timeit: 10b. module). * It is highly recommended to have good code coverage (through unit testing or any other technique) before potentially introducing regressions hidden in sophisticated optimizations. That being said, there are many tricks to speed up Python code. Here are some general principles which go a long way towards reaching acceptable performance levels: * Making your algorithms faster (or changing to faster ones) can yield much larger benefits than trying to sprinkle micro-optimization tricks all over your code. * Use the right data structures. Study documentation for the *note Built-in Types: 12be. and the *note collections: 1e. module. * When the standard library provides a primitive for doing something, it is likely (although not guaranteed) to be faster than any alternative you may come up with. This is doubly true for primitives written in C, such as builtins and some extension types. For example, be sure to use either the *note list.sort(): 445. built-in method or the related *note sorted(): 444. function to do sorting (and see the *note Sorting HOW TO: 12ab. for examples of moderately advanced usage). * Abstractions tend to create indirections and force the interpreter to work more. If the levels of indirection outweigh the amount of useful work done, your program will be slower. You should avoid excessive abstraction, especially under the form of tiny functions or methods (which are also often detrimental to readability). If you have reached the limit of what pure Python can allow, there are tools to take you further away. For example, Cython(1) can compile a slightly modified version of Python code into a C extension, and can be used on many different platforms. Cython can take advantage of compilation (and optional type annotations) to make your code significantly faster than when interpreted. If you are confident in your C programming skills, you can also *note write a C extension module: e90. yourself. See also ........ The wiki page devoted to performance tips(2). ---------- Footnotes ---------- (1) http://cython.org (2) https://wiki.python.org/moin/PythonSpeed/PerformanceTips  File: python.info, Node: What is the most efficient way to concatenate many strings together?, Prev: My program is too slow How do I speed it up?, Up: Performance<4> 11.2.4.2 What is the most efficient way to concatenate many strings together? ............................................................................. *note str: 330. and *note bytes: 331. objects are immutable, therefore concatenating many strings together is inefficient as each concatenation creates a new object. In the general case, the total runtime cost is quadratic in the total string length. To accumulate many *note str: 330. objects, the recommended idiom is to place them into a list and call *note str.join(): 12dd. at the end: chunks = [] for s in my_strings: chunks.append(s) result = ''.join(chunks) (another reasonably efficient idiom is to use *note io.StringIO: 82d.) To accumulate many *note bytes: 331. objects, the recommended idiom is to extend a *note bytearray: 332. object using in-place concatenation (the ‘+=’ operator): result = bytearray() for b in my_bytes_objects: result += b  File: python.info, Node: Sequences Tuples/Lists, Next: Objects, Prev: Performance<4>, Up: Programming FAQ 11.2.5 Sequences (Tuples/Lists) ------------------------------- * Menu: * How do I convert between tuples and lists?:: * What’s a negative index?:: * How do I iterate over a sequence in reverse order?:: * How do you remove duplicates from a list?:: * How do you remove multiple items from a list:: * How do you make an array in Python?:: * How do I create a multidimensional list?:: * How do I apply a method to a sequence of objects?:: * Why does a_tuple[i] += [‘item’] raise an exception when the addition works?:: * I want to do a complicated sort; can you do a Schwartzian Transform in Python?: I want to do a complicated sort can you do a Schwartzian Transform in Python?. * How can I sort one list by values from another list?::  File: python.info, Node: How do I convert between tuples and lists?, Next: What’s a negative index?, Up: Sequences Tuples/Lists 11.2.5.1 How do I convert between tuples and lists? ................................................... The type constructor ‘tuple(seq)’ converts any sequence (actually, any iterable) into a tuple with the same items in the same order. For example, ‘tuple([1, 2, 3])’ yields ‘(1, 2, 3)’ and ‘tuple('abc')’ yields ‘('a', 'b', 'c')’. If the argument is a tuple, it does not make a copy but returns the same object, so it is cheap to call *note tuple(): 47e. when you aren’t sure that an object is already a tuple. The type constructor ‘list(seq)’ converts any sequence or iterable into a list with the same items in the same order. For example, ‘list((1, 2, 3))’ yields ‘[1, 2, 3]’ and ‘list('abc')’ yields ‘['a', 'b', 'c']’. If the argument is a list, it makes a copy just like ‘seq[:]’ would.  File: python.info, Node: What’s a negative index?, Next: How do I iterate over a sequence in reverse order?, Prev: How do I convert between tuples and lists?, Up: Sequences Tuples/Lists 11.2.5.2 What’s a negative index? ................................. Python sequences are indexed with positive numbers and negative numbers. For positive numbers 0 is the first index 1 is the second index and so forth. For negative indices -1 is the last index and -2 is the penultimate (next to last) index and so forth. Think of ‘seq[-n]’ as the same as ‘seq[len(seq)-n]’. Using negative indices can be very convenient. For example ‘S[:-1]’ is all of the string except for its last character, which is useful for removing the trailing newline from a string.  File: python.info, Node: How do I iterate over a sequence in reverse order?, Next: How do you remove duplicates from a list?, Prev: What’s a negative index?, Up: Sequences Tuples/Lists 11.2.5.3 How do I iterate over a sequence in reverse order? ........................................................... Use the *note reversed(): 18e. built-in function: for x in reversed(sequence): ... # do something with x ... This won’t touch your original sequence, but build a new copy with reversed order to iterate over.  File: python.info, Node: How do you remove duplicates from a list?, Next: How do you remove multiple items from a list, Prev: How do I iterate over a sequence in reverse order?, Up: Sequences Tuples/Lists 11.2.5.4 How do you remove duplicates from a list? .................................................. See the Python Cookbook for a long discussion of many ways to do this: ‘https://code.activestate.com/recipes/52560/’ If you don’t mind reordering the list, sort it and then scan from the end of the list, deleting duplicates as you go: if mylist: mylist.sort() last = mylist[-1] for i in range(len(mylist)-2, -1, -1): if last == mylist[i]: del mylist[i] else: last = mylist[i] If all elements of the list may be used as set keys (i.e. they are all *note hashable: 10c8.) this is often faster mylist = list(set(mylist)) This converts the list into a set, thereby removing duplicates, and then back into a list.  File: python.info, Node: How do you remove multiple items from a list, Next: How do you make an array in Python?, Prev: How do you remove duplicates from a list?, Up: Sequences Tuples/Lists 11.2.5.5 How do you remove multiple items from a list ..................................................... As with removing duplicates, explicitly iterating in reverse with a delete condition is one possibility. However, it is easier and faster to use slice replacement with an implicit or explicit forward iteration. Here are three variations.: mylist[:] = filter(keep_function, mylist) mylist[:] = (x for x in mylist if keep_condition) mylist[:] = [x for x in mylist if keep_condition] The list comprehension may be fastest.  File: python.info, Node: How do you make an array in Python?, Next: How do I create a multidimensional list?, Prev: How do you remove multiple items from a list, Up: Sequences Tuples/Lists 11.2.5.6 How do you make an array in Python? ............................................ Use a list: ["this", 1, "is", "an", "array"] Lists are equivalent to C or Pascal arrays in their time complexity; the primary difference is that a Python list can contain objects of many different types. The ‘array’ module also provides methods for creating arrays of fixed types with compact representations, but they are slower to index than lists. Also note that the Numeric extensions and others define array-like structures with various characteristics as well. To get Lisp-style linked lists, you can emulate cons cells using tuples: lisp_list = ("like", ("this", ("example", None) ) ) If mutability is desired, you could use lists instead of tuples. Here the analogue of lisp car is ‘lisp_list[0]’ and the analogue of cdr is ‘lisp_list[1]’. Only do this if you’re sure you really need to, because it’s usually a lot slower than using Python lists.  File: python.info, Node: How do I create a multidimensional list?, Next: How do I apply a method to a sequence of objects?, Prev: How do you make an array in Python?, Up: Sequences Tuples/Lists 11.2.5.7 How do I create a multidimensional list? ................................................. You probably tried to make a multidimensional array like this: >>> A = [[None] * 2] * 3 This looks correct if you print it: >>> A [[None, None], [None, None], [None, None]] But when you assign a value, it shows up in multiple places: >>> A[0][0] = 5 >>> A [[5, None], [5, None], [5, None]] The reason is that replicating a list with ‘*’ doesn’t create copies, it only creates references to the existing objects. The ‘*3’ creates a list containing 3 references to the same list of length two. Changes to one row will show in all rows, which is almost certainly not what you want. The suggested approach is to create a list of the desired length first and then fill in each element with a newly created list: A = [None] * 3 for i in range(3): A[i] = [None] * 2 This generates a list containing 3 different lists of length two. You can also use a list comprehension: w, h = 2, 3 A = [[None] * w for i in range(h)] Or, you can use an extension that provides a matrix datatype; NumPy(1) is the best known. ---------- Footnotes ---------- (1) http://www.numpy.org/  File: python.info, Node: How do I apply a method to a sequence of objects?, Next: Why does a_tuple[i] += [‘item’] raise an exception when the addition works?, Prev: How do I create a multidimensional list?, Up: Sequences Tuples/Lists 11.2.5.8 How do I apply a method to a sequence of objects? .......................................................... Use a list comprehension: result = [obj.method() for obj in mylist]  File: python.info, Node: Why does a_tuple[i] += [‘item’] raise an exception when the addition works?, Next: I want to do a complicated sort can you do a Schwartzian Transform in Python?, Prev: How do I apply a method to a sequence of objects?, Up: Sequences Tuples/Lists 11.2.5.9 Why does a_tuple[i] += [‘item’] raise an exception when the addition works? .................................................................................... This is because of a combination of the fact that augmented assignment operators are `assignment' operators, and the difference between mutable and immutable objects in Python. This discussion applies in general when augmented assignment operators are applied to elements of a tuple that point to mutable objects, but we’ll use a ‘list’ and ‘+=’ as our exemplar. If you wrote: >>> a_tuple = (1, 2) >>> a_tuple[0] += 1 Traceback (most recent call last): ... TypeError: 'tuple' object does not support item assignment The reason for the exception should be immediately clear: ‘1’ is added to the object ‘a_tuple[0]’ points to (‘1’), producing the result object, ‘2’, but when we attempt to assign the result of the computation, ‘2’, to element ‘0’ of the tuple, we get an error because we can’t change what an element of a tuple points to. Under the covers, what this augmented assignment statement is doing is approximately this: >>> result = a_tuple[0] + 1 >>> a_tuple[0] = result Traceback (most recent call last): ... TypeError: 'tuple' object does not support item assignment It is the assignment part of the operation that produces the error, since a tuple is immutable. When you write something like: >>> a_tuple = (['foo'], 'bar') >>> a_tuple[0] += ['item'] Traceback (most recent call last): ... TypeError: 'tuple' object does not support item assignment The exception is a bit more surprising, and even more surprising is the fact that even though there was an error, the append worked: >>> a_tuple[0] ['foo', 'item'] To see why this happens, you need to know that (a) if an object implements an ‘__iadd__’ magic method, it gets called when the ‘+=’ augmented assignment is executed, and its return value is what gets used in the assignment statement; and (b) for lists, ‘__iadd__’ is equivalent to calling ‘extend’ on the list and returning the list. That’s why we say that for lists, ‘+=’ is a “shorthand” for ‘list.extend’: >>> a_list = [] >>> a_list += [1] >>> a_list [1] This is equivalent to: >>> result = a_list.__iadd__([1]) >>> a_list = result The object pointed to by a_list has been mutated, and the pointer to the mutated object is assigned back to ‘a_list’. The end result of the assignment is a no-op, since it is a pointer to the same object that ‘a_list’ was previously pointing to, but the assignment still happens. Thus, in our tuple example what is happening is equivalent to: >>> result = a_tuple[0].__iadd__(['item']) >>> a_tuple[0] = result Traceback (most recent call last): ... TypeError: 'tuple' object does not support item assignment The ‘__iadd__’ succeeds, and thus the list is extended, but even though ‘result’ points to the same object that ‘a_tuple[0]’ already points to, that final assignment still results in an error, because tuples are immutable.  File: python.info, Node: I want to do a complicated sort can you do a Schwartzian Transform in Python?, Next: How can I sort one list by values from another list?, Prev: Why does a_tuple[i] += [‘item’] raise an exception when the addition works?, Up: Sequences Tuples/Lists 11.2.5.10 I want to do a complicated sort: can you do a Schwartzian Transform in Python? ........................................................................................ The technique, attributed to Randal Schwartz of the Perl community, sorts the elements of a list by a metric which maps each element to its “sort value”. In Python, use the ‘key’ argument for the *note list.sort(): 445. method: Isorted = L[:] Isorted.sort(key=lambda s: int(s[10:15]))  File: python.info, Node: How can I sort one list by values from another list?, Prev: I want to do a complicated sort can you do a Schwartzian Transform in Python?, Up: Sequences Tuples/Lists 11.2.5.11 How can I sort one list by values from another list? .............................................................. Merge them into an iterator of tuples, sort the resulting list, and then pick out the element you want. >>> list1 = ["what", "I'm", "sorting", "by"] >>> list2 = ["something", "else", "to", "sort"] >>> pairs = zip(list1, list2) >>> pairs = sorted(pairs) >>> pairs [("I'm", 'else'), ('by', 'sort'), ('sorting', 'to'), ('what', 'something')] >>> result = [x[1] for x in pairs] >>> result ['else', 'sort', 'to', 'something'] An alternative for the last step is: >>> result = [] >>> for p in pairs: result.append(p[1]) If you find this more legible, you might prefer to use this instead of the final list comprehension. However, it is almost twice as slow for long lists. Why? First, the ‘append()’ operation has to reallocate memory, and while it uses some tricks to avoid doing that each time, it still has to do it occasionally, and that costs quite a bit. Second, the expression “result.append” requires an extra attribute lookup, and third, there’s a speed reduction from having to make all those function calls.  File: python.info, Node: Objects, Next: Modules<3>, Prev: Sequences Tuples/Lists, Up: Programming FAQ 11.2.6 Objects -------------- * Menu: * What is a class?:: * What is a method?:: * What is self?:: * How do I check if an object is an instance of a given class or of a subclass of it?:: * What is delegation?:: * How do I call a method defined in a base class from a derived class that overrides it?:: * How can I organize my code to make it easier to change the base class?:: * How do I create static class data and static class methods?:: * How can I overload constructors (or methods) in Python?: How can I overload constructors or methods in Python?. * I try to use __spam and I get an error about _SomeClassName__spam.: I try to use __spam and I get an error about _SomeClassName__spam. * My class defines __del__ but it is not called when I delete the object.: My class defines __del__ but it is not called when I delete the object. * How do I get a list of all instances of a given class?:: * Why does the result of id() appear to be not unique?: Why does the result of id appear to be not unique?.  File: python.info, Node: What is a class?, Next: What is a method?, Up: Objects 11.2.6.1 What is a class? ......................... A class is the particular object type created by executing a class statement. Class objects are used as templates to create instance objects, which embody both the data (attributes) and code (methods) specific to a datatype. A class can be based on one or more other classes, called its base class(es). It then inherits the attributes and methods of its base classes. This allows an object model to be successively refined by inheritance. You might have a generic ‘Mailbox’ class that provides basic accessor methods for a mailbox, and subclasses such as ‘MboxMailbox’, ‘MaildirMailbox’, ‘OutlookMailbox’ that handle various specific mailbox formats.  File: python.info, Node: What is a method?, Next: What is self?, Prev: What is a class?, Up: Objects 11.2.6.2 What is a method? .......................... A method is a function on some object ‘x’ that you normally call as ‘x.name(arguments...)’. Methods are defined as functions inside the class definition: class C: def meth(self, arg): return arg * 2 + self.attribute  File: python.info, Node: What is self?, Next: How do I check if an object is an instance of a given class or of a subclass of it?, Prev: What is a method?, Up: Objects 11.2.6.3 What is self? ...................... Self is merely a conventional name for the first argument of a method. A method defined as ‘meth(self, a, b, c)’ should be called as ‘x.meth(a, b, c)’ for some instance ‘x’ of the class in which the definition occurs; the called method will think it is called as ‘meth(x, a, b, c)’. See also *note Why must ‘self’ be used explicitly in method definitions and calls?: 3fde.  File: python.info, Node: How do I check if an object is an instance of a given class or of a subclass of it?, Next: What is delegation?, Prev: What is self?, Up: Objects 11.2.6.4 How do I check if an object is an instance of a given class or of a subclass of it? ............................................................................................ Use the built-in function ‘isinstance(obj, cls)’. You can check if an object is an instance of any of a number of classes by providing a tuple instead of a single class, e.g. ‘isinstance(obj, (class1, class2, ...))’, and can also check whether an object is one of Python’s built-in types, e.g. ‘isinstance(obj, str)’ or ‘isinstance(obj, (int, float, complex))’. Note that most programs do not use *note isinstance(): 44f. on user-defined classes very often. If you are developing the classes yourself, a more proper object-oriented style is to define methods on the classes that encapsulate a particular behaviour, instead of checking the object’s class and doing a different thing based on what class it is. For example, if you have a function that does something: def search(obj): if isinstance(obj, Mailbox): ... # code to search a mailbox elif isinstance(obj, Document): ... # code to search a document elif ... A better approach is to define a ‘search()’ method on all the classes and just call it: class Mailbox: def search(self): ... # code to search a mailbox class Document: def search(self): ... # code to search a document obj.search()  File: python.info, Node: What is delegation?, Next: How do I call a method defined in a base class from a derived class that overrides it?, Prev: How do I check if an object is an instance of a given class or of a subclass of it?, Up: Objects 11.2.6.5 What is delegation? ............................ Delegation is an object oriented technique (also called a design pattern). Let’s say you have an object ‘x’ and want to change the behaviour of just one of its methods. You can create a new class that provides a new implementation of the method you’re interested in changing and delegates all other methods to the corresponding method of ‘x’. Python programmers can easily implement delegation. For example, the following class implements a class that behaves like a file but converts all written data to uppercase: class UpperOut: def __init__(self, outfile): self._outfile = outfile def write(self, s): self._outfile.write(s.upper()) def __getattr__(self, name): return getattr(self._outfile, name) Here the ‘UpperOut’ class redefines the ‘write()’ method to convert the argument string to uppercase before calling the underlying ‘self._outfile.write()’ method. All other methods are delegated to the underlying ‘self._outfile’ object. The delegation is accomplished via the ‘__getattr__’ method; consult *note the language reference: 10db. for more information about controlling attribute access. Note that for more general cases delegation can get trickier. When attributes must be set as well as retrieved, the class must define a *note __setattr__(): e2c. method too, and it must do so carefully. The basic implementation of *note __setattr__(): e2c. is roughly equivalent to the following: class X: ... def __setattr__(self, name, value): self.__dict__[name] = value ... Most *note __setattr__(): e2c. implementations must modify ‘self.__dict__’ to store local state for self without causing an infinite recursion.  File: python.info, Node: How do I call a method defined in a base class from a derived class that overrides it?, Next: How can I organize my code to make it easier to change the base class?, Prev: What is delegation?, Up: Objects 11.2.6.6 How do I call a method defined in a base class from a derived class that overrides it? ............................................................................................... Use the built-in *note super(): 4e2. function: class Derived(Base): def meth(self): super(Derived, self).meth() For version prior to 3.0, you may be using classic classes: For a class definition such as ‘class Derived(Base): ...’ you can call method ‘meth()’ defined in ‘Base’ (or one of ‘Base’’s base classes) as ‘Base.meth(self, arguments...)’. Here, ‘Base.meth’ is an unbound method, so you need to provide the ‘self’ argument.  File: python.info, Node: How can I organize my code to make it easier to change the base class?, Next: How do I create static class data and static class methods?, Prev: How do I call a method defined in a base class from a derived class that overrides it?, Up: Objects 11.2.6.7 How can I organize my code to make it easier to change the base class? ............................................................................... You could define an alias for the base class, assign the real base class to it before your class definition, and use the alias throughout your class. Then all you have to change is the value assigned to the alias. Incidentally, this trick is also handy if you want to decide dynamically (e.g. depending on availability of resources) which base class to use. Example: BaseAlias = class Derived(BaseAlias): def meth(self): BaseAlias.meth(self) ...  File: python.info, Node: How do I create static class data and static class methods?, Next: How can I overload constructors or methods in Python?, Prev: How can I organize my code to make it easier to change the base class?, Up: Objects 11.2.6.8 How do I create static class data and static class methods? .................................................................... Both static data and static methods (in the sense of C++ or Java) are supported in Python. For static data, simply define a class attribute. To assign a new value to the attribute, you have to explicitly use the class name in the assignment: class C: count = 0 # number of times C.__init__ called def __init__(self): C.count = C.count + 1 def getcount(self): return C.count # or return self.count ‘c.count’ also refers to ‘C.count’ for any ‘c’ such that ‘isinstance(c, C)’ holds, unless overridden by ‘c’ itself or by some class on the base-class search path from ‘c.__class__’ back to ‘C’. Caution: within a method of C, an assignment like ‘self.count = 42’ creates a new and unrelated instance named “count” in ‘self’’s own dict. Rebinding of a class-static data name must always specify the class whether inside a method or not: C.count = 314 Static methods are possible: class C: @staticmethod def static(arg1, arg2, arg3): # No 'self' parameter! ... However, a far more straightforward way to get the effect of a static method is via a simple module-level function: def getcount(): return C.count If your code is structured so as to define one class (or tightly related class hierarchy) per module, this supplies the desired encapsulation.  File: python.info, Node: How can I overload constructors or methods in Python?, Next: I try to use __spam and I get an error about _SomeClassName__spam, Prev: How do I create static class data and static class methods?, Up: Objects 11.2.6.9 How can I overload constructors (or methods) in Python? ................................................................ This answer actually applies to all methods, but the question usually comes up first in the context of constructors. In C++ you’d write class C { C() { cout << "No arguments\n"; } C(int i) { cout << "Argument is " << i << "\n"; } } In Python you have to write a single constructor that catches all cases using default arguments. For example: class C: def __init__(self, i=None): if i is None: print("No arguments") else: print("Argument is", i) This is not entirely equivalent, but close enough in practice. You could also try a variable-length argument list, e.g. def __init__(self, *args): ... The same approach works for all method definitions.  File: python.info, Node: I try to use __spam and I get an error about _SomeClassName__spam, Next: My class defines __del__ but it is not called when I delete the object, Prev: How can I overload constructors or methods in Python?, Up: Objects 11.2.6.10 I try to use __spam and I get an error about _SomeClassName__spam. ............................................................................ Variable names with double leading underscores are “mangled” to provide a simple but effective way to define class private variables. Any identifier of the form ‘__spam’ (at least two leading underscores, at most one trailing underscore) is textually replaced with ‘_classname__spam’, where ‘classname’ is the current class name with any leading underscores stripped. This doesn’t guarantee privacy: an outside user can still deliberately access the “_classname__spam” attribute, and private values are visible in the object’s ‘__dict__’. Many Python programmers never bother to use private variable names at all.  File: python.info, Node: My class defines __del__ but it is not called when I delete the object, Next: How do I get a list of all instances of a given class?, Prev: I try to use __spam and I get an error about _SomeClassName__spam, Up: Objects 11.2.6.11 My class defines __del__ but it is not called when I delete the object. ................................................................................. There are several possible reasons for this. The del statement does not necessarily call *note __del__(): 91f. – it simply decrements the object’s reference count, and if this reaches zero *note __del__(): 91f. is called. If your data structures contain circular links (e.g. a tree where each child has a parent reference and each parent has a list of children) the reference counts will never go back to zero. Once in a while Python runs an algorithm to detect such cycles, but the garbage collector might run some time after the last reference to your data structure vanishes, so your *note __del__(): 91f. method may be called at an inconvenient and random time. This is inconvenient if you’re trying to reproduce a problem. Worse, the order in which object’s *note __del__(): 91f. methods are executed is arbitrary. You can run *note gc.collect(): 22e. to force a collection, but there `are' pathological cases where objects will never be collected. Despite the cycle collector, it’s still a good idea to define an explicit ‘close()’ method on objects to be called whenever you’re done with them. The ‘close()’ method can then remove attributes that refer to subobjects. Don’t call *note __del__(): 91f. directly – *note __del__(): 91f. should call ‘close()’ and ‘close()’ should make sure that it can be called more than once for the same object. Another way to avoid cyclical references is to use the *note weakref: 128. module, which allows you to point to objects without incrementing their reference count. Tree data structures, for instance, should use weak references for their parent and sibling references (if they need them!). Finally, if your *note __del__(): 91f. method raises an exception, a warning message is printed to *note sys.stderr: 30f.  File: python.info, Node: How do I get a list of all instances of a given class?, Next: Why does the result of id appear to be not unique?, Prev: My class defines __del__ but it is not called when I delete the object, Up: Objects 11.2.6.12 How do I get a list of all instances of a given class? ................................................................ Python does not keep track of all instances of a class (or of a built-in type). You can program the class’s constructor to keep track of all instances by keeping a list of weak references to each instance.  File: python.info, Node: Why does the result of id appear to be not unique?, Prev: How do I get a list of all instances of a given class?, Up: Objects 11.2.6.13 Why does the result of ‘id()’ appear to be not unique? ................................................................ The *note id(): d86. builtin returns an integer that is guaranteed to be unique during the lifetime of the object. Since in CPython, this is the object’s memory address, it happens frequently that after an object is deleted from memory, the next freshly created object is allocated at the same position in memory. This is illustrated by this example: >>> id(1000) 13901272 >>> id(2000) 13901272 The two ids belong to different integer objects that are created before, and deleted immediately after execution of the ‘id()’ call. To be sure that objects whose id you want to examine are still alive, create another reference to the object: >>> a = 1000; b = 2000 >>> id(a) 13901272 >>> id(b) 13891296  File: python.info, Node: Modules<3>, Prev: Objects, Up: Programming FAQ 11.2.7 Modules -------------- * Menu: * How do I create a .pyc file?: How do I create a pyc file?. * How do I find the current module name?:: * How can I have modules that mutually import each other?:: * __import__(‘x.y.z’) returns ; how do I get z?: __import__ ‘x y z’ returns ; how do I get z?. * When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?: When I edit an imported module and reimport it the changes don’t show up Why does this happen?.  File: python.info, Node: How do I create a pyc file?, Next: How do I find the current module name?, Up: Modules<3> 11.2.7.1 How do I create a .pyc file? ..................................... When a module is imported for the first time (or when the source file has changed since the current compiled file was created) a ‘.pyc’ file containing the compiled code should be created in a ‘__pycache__’ subdirectory of the directory containing the ‘.py’ file. The ‘.pyc’ file will have a filename that starts with the same name as the ‘.py’ file, and ends with ‘.pyc’, with a middle component that depends on the particular ‘python’ binary that created it. (See PEP 3147(1) for details.) One reason that a ‘.pyc’ file may not be created is a permissions problem with the directory containing the source file, meaning that the ‘__pycache__’ subdirectory cannot be created. This can happen, for example, if you develop as one user but run as another, such as if you are testing with a web server. Unless the *note PYTHONDONTWRITEBYTECODE: d39. environment variable is set, creation of a .pyc file is automatic if you’re importing a module and Python has the ability (permissions, free space, etc…) to create a ‘__pycache__’ subdirectory and write the compiled module to that subdirectory. Running Python on a top level script is not considered an import and no ‘.pyc’ will be created. For example, if you have a top-level module ‘foo.py’ that imports another module ‘xyz.py’, when you run ‘foo’ (by typing ‘python foo.py’ as a shell command), a ‘.pyc’ will be created for ‘xyz’ because ‘xyz’ is imported, but no ‘.pyc’ file will be created for ‘foo’ since ‘foo.py’ isn’t being imported. If you need to create a ‘.pyc’ file for ‘foo’ – that is, to create a ‘.pyc’ file for a module that is not imported – you can, using the *note py_compile: d7. and *note compileall: 21. modules. The *note py_compile: d7. module can manually compile any module. One way is to use the ‘compile()’ function in that module interactively: >>> import py_compile >>> py_compile.compile('foo.py') This will write the ‘.pyc’ to a ‘__pycache__’ subdirectory in the same location as ‘foo.py’ (or you can override that with the optional parameter ‘cfile’). You can also automatically compile all files in a directory or directories using the *note compileall: 21. module. You can do it from the shell prompt by running ‘compileall.py’ and providing the path of a directory containing Python files to compile: python -m compileall . ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147  File: python.info, Node: How do I find the current module name?, Next: How can I have modules that mutually import each other?, Prev: How do I create a pyc file?, Up: Modules<3> 11.2.7.2 How do I find the current module name? ............................................... A module can find out its own module name by looking at the predefined global variable ‘__name__’. If this has the value ‘'__main__'’, the program is running as a script. Many modules that are usually used by importing them also provide a command-line interface or a self-test, and only execute this code after checking ‘__name__’: def main(): print('Running test...') ... if __name__ == '__main__': main()  File: python.info, Node: How can I have modules that mutually import each other?, Next: __import__ ‘x y z’ returns ; how do I get z?, Prev: How do I find the current module name?, Up: Modules<3> 11.2.7.3 How can I have modules that mutually import each other? ................................................................ Suppose you have the following modules: foo.py: from bar import bar_var foo_var = 1 bar.py: from foo import foo_var bar_var = 2 The problem is that the interpreter will perform the following steps: * main imports foo * Empty globals for foo are created * foo is compiled and starts executing * foo imports bar * Empty globals for bar are created * bar is compiled and starts executing * bar imports foo (which is a no-op since there already is a module named foo) * bar.foo_var = foo.foo_var The last step fails, because Python isn’t done with interpreting ‘foo’ yet and the global symbol dictionary for ‘foo’ is still empty. The same thing happens when you use ‘import foo’, and then try to access ‘foo.foo_var’ in global code. There are (at least) three possible workarounds for this problem. Guido van Rossum recommends avoiding all uses of ‘from import ...’, and placing all code inside functions. Initializations of global variables and class variables should use constants or built-in functions only. This means everything from an imported module is referenced as ‘.’. Jim Roskind suggests performing steps in the following order in each module: * exports (globals, functions, and classes that don’t need imported base classes) * ‘import’ statements * active code (including globals that are initialized from imported values). van Rossum doesn’t like this approach much because the imports appear in a strange place, but it does work. Matthias Urlichs recommends restructuring your code so that the recursive import is not necessary in the first place. These solutions are not mutually exclusive.  File: python.info, Node: __import__ ‘x y z’ returns ; how do I get z?, Next: When I edit an imported module and reimport it the changes don’t show up Why does this happen?, Prev: How can I have modules that mutually import each other?, Up: Modules<3> 11.2.7.4 __import__(‘x.y.z’) returns ; how do I get z? .................................................................. Consider using the convenience function *note import_module(): b13. from *note importlib: 9b. instead: z = importlib.import_module('x.y.z')  File: python.info, Node: When I edit an imported module and reimport it the changes don’t show up Why does this happen?, Prev: __import__ ‘x y z’ returns ; how do I get z?, Up: Modules<3> 11.2.7.5 When I edit an imported module and reimport it, the changes don’t show up. Why does this happen? ......................................................................................................... For reasons of efficiency as well as consistency, Python only reads the module file on the first time a module is imported. If it didn’t, in a program consisting of many modules where each one imports the same basic module, the basic module would be parsed and re-parsed many times. To force re-reading of a changed module, do this: import importlib import modname importlib.reload(modname) Warning: this technique is not 100% fool-proof. In particular, modules containing statements like from modname import some_objects will continue to work with the old version of the imported objects. If the module contains class definitions, existing class instances will `not' be updated to use the new class definition. This can result in the following paradoxical behaviour: >>> import importlib >>> import cls >>> c = cls.C() # Create an instance of C >>> importlib.reload(cls) >>> isinstance(c, cls.C) # isinstance is false?!? False The nature of the problem is made clear if you print out the “identity” of the class objects: >>> hex(id(c.__class__)) '0x7352a0' >>> hex(id(cls.C)) '0x4198d0'  File: python.info, Node: Design and History FAQ, Next: Library and Extension FAQ, Prev: Programming FAQ, Up: Python Frequently Asked Questions 11.3 Design and History FAQ =========================== * Menu: * Why does Python use indentation for grouping of statements?:: * Why am I getting strange results with simple arithmetic operations?:: * Why are floating-point calculations so inaccurate?:: * Why are Python strings immutable?:: * Why must ‘self’ be used explicitly in method definitions and calls?:: * Why can’t I use an assignment in an expression?:: * Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?: Why does Python use methods for some functionality e g list index but functions for other e g len list ?. * Why is join() a string method instead of a list or tuple method?: Why is join a string method instead of a list or tuple method?. * How fast are exceptions?:: * Why isn’t there a switch or case statement in Python?:: * Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?:: * Why can’t lambda expressions contain statements?:: * Can Python be compiled to machine code, C or some other language?: Can Python be compiled to machine code C or some other language?. * How does Python manage memory?:: * Why doesn’t CPython use a more traditional garbage collection scheme?:: * Why isn’t all memory freed when CPython exits?:: * Why are there separate tuple and list data types?:: * How are lists implemented in CPython?:: * How are dictionaries implemented in CPython?:: * Why must dictionary keys be immutable?:: * Why doesn’t list.sort() return the sorted list?: Why doesn’t list sort return the sorted list?. * How do you specify and enforce an interface spec in Python?:: * Why is there no goto?:: * Why can’t raw strings (r-strings) end with a backslash?: Why can’t raw strings r-strings end with a backslash?. * Why doesn’t Python have a “with” statement for attribute assignments?:: * Why are colons required for the if/while/def/class statements?:: * Why does Python allow commas at the end of lists and tuples?::  File: python.info, Node: Why does Python use indentation for grouping of statements?, Next: Why am I getting strange results with simple arithmetic operations?, Up: Design and History FAQ 11.3.1 Why does Python use indentation for grouping of statements? ------------------------------------------------------------------ Guido van Rossum believes that using indentation for grouping is extremely elegant and contributes a lot to the clarity of the average Python program. Most people learn to love this feature after a while. Since there are no begin/end brackets there cannot be a disagreement between grouping perceived by the parser and the human reader. Occasionally C programmers will encounter a fragment of code like this: if (x <= y) x++; y--; z++; Only the ‘x++’ statement is executed if the condition is true, but the indentation leads you to believe otherwise. Even experienced C programmers will sometimes stare at it a long time wondering why ‘y’ is being decremented even for ‘x > y’. Because there are no begin/end brackets, Python is much less prone to coding-style conflicts. In C there are many different ways to place the braces. If you’re used to reading and writing code that uses one style, you will feel at least slightly uneasy when reading (or being required to write) another style. Many coding styles place begin/end brackets on a line by themselves. This makes programs considerably longer and wastes valuable screen space, making it harder to get a good overview of a program. Ideally, a function should fit on one screen (say, 20–30 lines). 20 lines of Python can do a lot more work than 20 lines of C. This is not solely due to the lack of begin/end brackets – the lack of declarations and the high-level data types are also responsible – but the indentation-based syntax certainly helps.  File: python.info, Node: Why am I getting strange results with simple arithmetic operations?, Next: Why are floating-point calculations so inaccurate?, Prev: Why does Python use indentation for grouping of statements?, Up: Design and History FAQ 11.3.2 Why am I getting strange results with simple arithmetic operations? -------------------------------------------------------------------------- See the next question.  File: python.info, Node: Why are floating-point calculations so inaccurate?, Next: Why are Python strings immutable?, Prev: Why am I getting strange results with simple arithmetic operations?, Up: Design and History FAQ 11.3.3 Why are floating-point calculations so inaccurate? --------------------------------------------------------- Users are often surprised by results like this: >>> 1.2 - 1.0 0.19999999999999996 and think it is a bug in Python. It’s not. This has little to do with Python, and much more to do with how the underlying platform handles floating-point numbers. The *note float: 187. type in CPython uses a C ‘double’ for storage. A *note float: 187. object’s value is stored in binary floating-point with a fixed precision (typically 53 bits) and Python uses C operations, which in turn rely on the hardware implementation in the processor, to perform floating-point operations. This means that as far as floating-point operations are concerned, Python behaves like many popular languages including C and Java. Many numbers that can be written easily in decimal notation cannot be expressed exactly in binary floating-point. For example, after: >>> x = 1.2 the value stored for ‘x’ is a (very good) approximation to the decimal value ‘1.2’, but is not exactly equal to it. On a typical machine, the actual stored value is: 1.0011001100110011001100110011001100110011001100110011 (binary) which is exactly: 1.1999999999999999555910790149937383830547332763671875 (decimal) The typical precision of 53 bits provides Python floats with 15–16 decimal digits of accuracy. For a fuller explanation, please see the *note floating point arithmetic: fb8. chapter in the Python tutorial.  File: python.info, Node: Why are Python strings immutable?, Next: Why must ‘self’ be used explicitly in method definitions and calls?, Prev: Why are floating-point calculations so inaccurate?, Up: Design and History FAQ 11.3.4 Why are Python strings immutable? ---------------------------------------- There are several advantages. One is performance: knowing that a string is immutable means we can allocate space for it at creation time, and the storage requirements are fixed and unchanging. This is also one of the reasons for the distinction between tuples and lists. Another advantage is that strings in Python are considered as “elemental” as numbers. No amount of activity will change the value 8 to anything else, and in Python, no amount of activity will change the string “eight” to anything else.  File: python.info, Node: Why must ‘self’ be used explicitly in method definitions and calls?, Next: Why can’t I use an assignment in an expression?, Prev: Why are Python strings immutable?, Up: Design and History FAQ 11.3.5 Why must ‘self’ be used explicitly in method definitions and calls? -------------------------------------------------------------------------- The idea was borrowed from Modula-3. It turns out to be very useful, for a variety of reasons. First, it’s more obvious that you are using a method or instance attribute instead of a local variable. Reading ‘self.x’ or ‘self.meth()’ makes it absolutely clear that an instance variable or method is used even if you don’t know the class definition by heart. In C++, you can sort of tell by the lack of a local variable declaration (assuming globals are rare or easily recognizable) – but in Python, there are no local variable declarations, so you’d have to look up the class definition to be sure. Some C++ and Java coding standards call for instance attributes to have an ‘m_’ prefix, so this explicitness is still useful in those languages, too. Second, it means that no special syntax is necessary if you want to explicitly reference or call the method from a particular class. In C++, if you want to use a method from a base class which is overridden in a derived class, you have to use the ‘::’ operator – in Python you can write ‘baseclass.methodname(self, )’. This is particularly useful for *note __init__(): d5e. methods, and in general in cases where a derived class method wants to extend the base class method of the same name and thus has to call the base class method somehow. Finally, for instance variables it solves a syntactic problem with assignment: since local variables in Python are (by definition!) those variables to which a value is assigned in a function body (and that aren’t explicitly declared global), there has to be some way to tell the interpreter that an assignment was meant to assign to an instance variable instead of to a local variable, and it should preferably be syntactic (for efficiency reasons). C++ does this through declarations, but Python doesn’t have declarations and it would be a pity having to introduce them just for this purpose. Using the explicit ‘self.var’ solves this nicely. Similarly, for using instance variables, having to write ‘self.var’ means that references to unqualified names inside a method don’t have to search the instance’s directories. To put it another way, local variables and instance variables live in two different namespaces, and you need to tell Python which namespace to use.  File: python.info, Node: Why can’t I use an assignment in an expression?, Next: Why does Python use methods for some functionality e g list index but functions for other e g len list ?, Prev: Why must ‘self’ be used explicitly in method definitions and calls?, Up: Design and History FAQ 11.3.6 Why can’t I use an assignment in an expression? ------------------------------------------------------ Starting in Python 3.8, you can! Assignment expressions using the walrus operator ‘:=’ assign a variable in an expression: while chunk := fp.read(200): print(chunk) See PEP 572(1) for more information. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0572  File: python.info, Node: Why does Python use methods for some functionality e g list index but functions for other e g len list ?, Next: Why is join a string method instead of a list or tuple method?, Prev: Why can’t I use an assignment in an expression?, Up: Design and History FAQ 11.3.7 Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))? ----------------------------------------------------------------------------------------------------------------------- As Guido said: (a) For some operations, prefix notation just reads better than postfix – prefix (and infix!) operations have a long tradition in mathematics which likes notations where the visuals help the mathematician thinking about a problem. Compare the easy with which we rewrite a formula like x*(a+b) into x*a + x*b to the clumsiness of doing the same thing using a raw OO notation. (b) When I read code that says len(x) I `know' that it is asking for the length of something. This tells me two things: the result is an integer, and the argument is some kind of container. To the contrary, when I read x.len(), I have to already know that x is some kind of container implementing an interface or inheriting from a class that has a standard len(). Witness the confusion we occasionally have when a class that is not implementing a mapping has a get() or keys() method, or something that isn’t a file has a write() method. — ‘https://mail.python.org/pipermail/python-3000/2006-November/004643.html’  File: python.info, Node: Why is join a string method instead of a list or tuple method?, Next: How fast are exceptions?, Prev: Why does Python use methods for some functionality e g list index but functions for other e g len list ?, Up: Design and History FAQ 11.3.8 Why is join() a string method instead of a list or tuple method? ----------------------------------------------------------------------- Strings became much more like other standard types starting in Python 1.6, when methods were added which give the same functionality that has always been available using the functions of the string module. Most of these new methods have been widely accepted, but the one which appears to make some programmers feel uncomfortable is: ", ".join(['1', '2', '4', '8', '16']) which gives the result: "1, 2, 4, 8, 16" There are two common arguments against this usage. The first runs along the lines of: “It looks really ugly using a method of a string literal (string constant)”, to which the answer is that it might, but a string literal is just a fixed value. If the methods are to be allowed on names bound to strings there is no logical reason to make them unavailable on literals. The second objection is typically cast as: “I am really telling a sequence to join its members together with a string constant”. Sadly, you aren’t. For some reason there seems to be much less difficulty with having *note split(): 7a1. as a string method, since in that case it is easy to see that "1, 2, 4, 8, 16".split(", ") is an instruction to a string literal to return the substrings delimited by the given separator (or, by default, arbitrary runs of white space). *note join(): 12dd. is a string method because in using it you are telling the separator string to iterate over a sequence of strings and insert itself between adjacent elements. This method can be used with any argument which obeys the rules for sequence objects, including any new classes you might define yourself. Similar methods exist for bytes and bytearray objects.  File: python.info, Node: How fast are exceptions?, Next: Why isn’t there a switch or case statement in Python?, Prev: Why is join a string method instead of a list or tuple method?, Up: Design and History FAQ 11.3.9 How fast are exceptions? ------------------------------- A try/except block is extremely efficient if no exceptions are raised. Actually catching an exception is expensive. In versions of Python prior to 2.0 it was common to use this idiom: try: value = mydict[key] except KeyError: mydict[key] = getvalue(key) value = mydict[key] This only made sense when you expected the dict to have the key almost all the time. If that wasn’t the case, you coded it like this: if key in mydict: value = mydict[key] else: value = mydict[key] = getvalue(key) For this specific case, you could also use ‘value = dict.setdefault(key, getvalue(key))’, but only if the ‘getvalue()’ call is cheap enough because it is evaluated in all cases.  File: python.info, Node: Why isn’t there a switch or case statement in Python?, Next: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?, Prev: How fast are exceptions?, Up: Design and History FAQ 11.3.10 Why isn’t there a switch or case statement in Python? ------------------------------------------------------------- You can do this easily enough with a sequence of ‘if... elif... elif... else’. There have been some proposals for switch statement syntax, but there is no consensus (yet) on whether and how to do range tests. See PEP 275(1) for complete details and the current status. For cases where you need to choose from a very large number of possibilities, you can create a dictionary mapping case values to functions to call. For example: def function_1(...): ... functions = {'a': function_1, 'b': function_2, 'c': self.method_1, ...} func = functions[value] func() For calling methods on objects, you can simplify yet further by using the *note getattr(): 448. built-in to retrieve methods with a particular name: def visit_a(self, ...): ... ... def dispatch(self, value): method_name = 'visit_' + str(value) method = getattr(self, method_name) method() It’s suggested that you use a prefix for the method names, such as ‘visit_’ in this example. Without such a prefix, if values are coming from an untrusted source, an attacker would be able to call any method on your object. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0275  File: python.info, Node: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?, Next: Why can’t lambda expressions contain statements?, Prev: Why isn’t there a switch or case statement in Python?, Up: Design and History FAQ 11.3.11 Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation? ---------------------------------------------------------------------------------------------------------------- Answer 1: Unfortunately, the interpreter pushes at least one C stack frame for each Python stack frame. Also, extensions can call back into Python at almost random moments. Therefore, a complete threads implementation requires thread support for C. Answer 2: Fortunately, there is Stackless Python(1), which has a completely redesigned interpreter loop that avoids the C stack. ---------- Footnotes ---------- (1) https://github.com/stackless-dev/stackless/wiki  File: python.info, Node: Why can’t lambda expressions contain statements?, Next: Can Python be compiled to machine code C or some other language?, Prev: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?, Up: Design and History FAQ 11.3.12 Why can’t lambda expressions contain statements? -------------------------------------------------------- Python lambda expressions cannot contain statements because Python’s syntactic framework can’t handle statements nested inside expressions. However, in Python, this is not a serious problem. Unlike lambda forms in other languages, where they add functionality, Python lambdas are only a shorthand notation if you’re too lazy to define a function. Functions are already first class objects in Python, and can be declared in a local scope. Therefore the only advantage of using a lambda instead of a locally-defined function is that you don’t need to invent a name for the function – but that’s just a local variable to which the function object (which is exactly the same type of object that a lambda expression yields) is assigned!  File: python.info, Node: Can Python be compiled to machine code C or some other language?, Next: How does Python manage memory?, Prev: Why can’t lambda expressions contain statements?, Up: Design and History FAQ 11.3.13 Can Python be compiled to machine code, C or some other language? ------------------------------------------------------------------------- Cython(1) compiles a modified version of Python with optional annotations into C extensions. Nuitka(2) is an up-and-coming compiler of Python into C++ code, aiming to support the full Python language. For compiling to Java you can consider VOC(3). ---------- Footnotes ---------- (1) http://cython.org/ (2) http://www.nuitka.net/ (3) https://voc.readthedocs.io  File: python.info, Node: How does Python manage memory?, Next: Why doesn’t CPython use a more traditional garbage collection scheme?, Prev: Can Python be compiled to machine code C or some other language?, Up: Design and History FAQ 11.3.14 How does Python manage memory? -------------------------------------- The details of Python memory management depend on the implementation. The standard implementation of Python, *note CPython: 10d7, uses reference counting to detect inaccessible objects, and another mechanism to collect reference cycles, periodically executing a cycle detection algorithm which looks for inaccessible cycles and deletes the objects involved. The *note gc: 86. module provides functions to perform a garbage collection, obtain debugging statistics, and tune the collector’s parameters. Other implementations (such as Jython(1) or PyPy(2)), however, can rely on a different mechanism such as a full-blown garbage collector. This difference can cause some subtle porting problems if your Python code depends on the behavior of the reference counting implementation. In some Python implementations, the following code (which is fine in CPython) will probably run out of file descriptors: for file in very_long_list_of_files: f = open(file) c = f.read(1) Indeed, using CPython’s reference counting and destructor scheme, each new assignment to `f' closes the previous file. With a traditional GC, however, those file objects will only get collected (and closed) at varying and possibly long intervals. If you want to write code that will work with any Python implementation, you should explicitly close the file or use the *note with: 6e9. statement; this will work regardless of memory management scheme: for file in very_long_list_of_files: with open(file) as f: c = f.read(1) ---------- Footnotes ---------- (1) http://www.jython.org (2) http://www.pypy.org  File: python.info, Node: Why doesn’t CPython use a more traditional garbage collection scheme?, Next: Why isn’t all memory freed when CPython exits?, Prev: How does Python manage memory?, Up: Design and History FAQ 11.3.15 Why doesn’t CPython use a more traditional garbage collection scheme? ----------------------------------------------------------------------------- For one thing, this is not a C standard feature and hence it’s not portable. (Yes, we know about the Boehm GC library. It has bits of assembler code for `most' common platforms, not for all of them, and although it is mostly transparent, it isn’t completely transparent; patches are required to get Python to work with it.) Traditional GC also becomes a problem when Python is embedded into other applications. While in a standalone Python it’s fine to replace the standard malloc() and free() with versions provided by the GC library, an application embedding Python may want to have its `own' substitute for malloc() and free(), and may not want Python’s. Right now, CPython works with anything that implements malloc() and free() properly.  File: python.info, Node: Why isn’t all memory freed when CPython exits?, Next: Why are there separate tuple and list data types?, Prev: Why doesn’t CPython use a more traditional garbage collection scheme?, Up: Design and History FAQ 11.3.16 Why isn’t all memory freed when CPython exits? ------------------------------------------------------ Objects referenced from the global namespaces of Python modules are not always deallocated when Python exits. This may happen if there are circular references. There are also certain bits of memory that are allocated by the C library that are impossible to free (e.g. a tool like Purify will complain about these). Python is, however, aggressive about cleaning up memory on exit and does try to destroy every single object. If you want to force Python to delete certain things on deallocation use the *note atexit: c. module to run a function that will force those deletions.  File: python.info, Node: Why are there separate tuple and list data types?, Next: How are lists implemented in CPython?, Prev: Why isn’t all memory freed when CPython exits?, Up: Design and History FAQ 11.3.17 Why are there separate tuple and list data types? --------------------------------------------------------- Lists and tuples, while similar in many respects, are generally used in fundamentally different ways. Tuples can be thought of as being similar to Pascal records or C structs; they’re small collections of related data which may be of different types which are operated on as a group. For example, a Cartesian coordinate is appropriately represented as a tuple of two or three numbers. Lists, on the other hand, are more like arrays in other languages. They tend to hold a varying number of objects all of which have the same type and which are operated on one-by-one. For example, ‘os.listdir('.')’ returns a list of strings representing the files in the current directory. Functions which operate on this output would generally not break if you added another file or two to the directory. Tuples are immutable, meaning that once a tuple has been created, you can’t replace any of its elements with a new value. Lists are mutable, meaning that you can always change a list’s elements. Only immutable elements can be used as dictionary keys, and hence only tuples and not lists can be used as keys.  File: python.info, Node: How are lists implemented in CPython?, Next: How are dictionaries implemented in CPython?, Prev: Why are there separate tuple and list data types?, Up: Design and History FAQ 11.3.18 How are lists implemented in CPython? --------------------------------------------- CPython’s lists are really variable-length arrays, not Lisp-style linked lists. The implementation uses a contiguous array of references to other objects, and keeps a pointer to this array and the array’s length in a list head structure. This makes indexing a list ‘a[i]’ an operation whose cost is independent of the size of the list or the value of the index. When items are appended or inserted, the array of references is resized. Some cleverness is applied to improve the performance of appending items repeatedly; when the array must be grown, some extra space is allocated so the next few times don’t require an actual resize.  File: python.info, Node: How are dictionaries implemented in CPython?, Next: Why must dictionary keys be immutable?, Prev: How are lists implemented in CPython?, Up: Design and History FAQ 11.3.19 How are dictionaries implemented in CPython? ---------------------------------------------------- CPython’s dictionaries are implemented as resizable hash tables. Compared to B-trees, this gives better performance for lookup (the most common operation by far) under most circumstances, and the implementation is simpler. Dictionaries work by computing a hash code for each key stored in the dictionary using the *note hash(): 9c4. built-in function. The hash code varies widely depending on the key and a per-process seed; for example, “Python” could hash to -539294296 while “python”, a string that differs by a single bit, could hash to 1142331976. The hash code is then used to calculate a location in an internal array where the value will be stored. Assuming that you’re storing keys that all have different hash values, this means that dictionaries take constant time – O(1), in Big-O notation – to retrieve a key.  File: python.info, Node: Why must dictionary keys be immutable?, Next: Why doesn’t list sort return the sorted list?, Prev: How are dictionaries implemented in CPython?, Up: Design and History FAQ 11.3.20 Why must dictionary keys be immutable? ---------------------------------------------- The hash table implementation of dictionaries uses a hash value calculated from the key value to find the key. If the key were a mutable object, its value could change, and thus its hash could also change. But since whoever changes the key object can’t tell that it was being used as a dictionary key, it can’t move the entry around in the dictionary. Then, when you try to look up the same object in the dictionary it won’t be found because its hash value is different. If you tried to look up the old value it wouldn’t be found either, because the value of the object found in that hash bin would be different. If you want a dictionary indexed with a list, simply convert the list to a tuple first; the function ‘tuple(L)’ creates a tuple with the same entries as the list ‘L’. Tuples are immutable and can therefore be used as dictionary keys. Some unacceptable solutions that have been proposed: - Hash lists by their address (object ID). This doesn’t work because if you construct a new list with the same value it won’t be found; e.g.: mydict = {[1, 2]: '12'} print(mydict[[1, 2]]) would raise a *note KeyError: 2c7. exception because the id of the ‘[1, 2]’ used in the second line differs from that in the first line. In other words, dictionary keys should be compared using ‘==’, not using *note is: 10be. - Make a copy when using a list as a key. This doesn’t work because the list, being a mutable object, could contain a reference to itself, and then the copying code would run into an infinite loop. - Allow lists as keys but tell the user not to modify them. This would allow a class of hard-to-track bugs in programs when you forgot or modified a list by accident. It also invalidates an important invariant of dictionaries: every value in ‘d.keys()’ is usable as a key of the dictionary. - Mark lists as read-only once they are used as a dictionary key. The problem is that it’s not just the top-level object that could change its value; you could use a tuple containing a list as a key. Entering anything as a key into a dictionary would require marking all objects reachable from there as read-only – and again, self-referential objects could cause an infinite loop. There is a trick to get around this if you need to, but use it at your own risk: You can wrap a mutable structure inside a class instance which has both a *note __eq__(): 33f. and a *note __hash__(): 340. method. You must then make sure that the hash value for all such wrapper objects that reside in a dictionary (or other hash based structure), remain fixed while the object is in the dictionary (or other structure). class ListWrapper: def __init__(self, the_list): self.the_list = the_list def __eq__(self, other): return self.the_list == other.the_list def __hash__(self): l = self.the_list result = 98767 - len(l)*555 for i, el in enumerate(l): try: result = result + (hash(el) % 9999999) * 1001 + i except Exception: result = (result % 7777777) + i * 333 return result Note that the hash computation is complicated by the possibility that some members of the list may be unhashable and also by the possibility of arithmetic overflow. Furthermore it must always be the case that if ‘o1 == o2’ (ie ‘o1.__eq__(o2) is True’) then ‘hash(o1) == hash(o2)’ (ie, ‘o1.__hash__() == o2.__hash__()’), regardless of whether the object is in a dictionary or not. If you fail to meet these restrictions dictionaries and other hash based structures will misbehave. In the case of ListWrapper, whenever the wrapper object is in a dictionary the wrapped list must not change to avoid anomalies. Don’t do this unless you are prepared to think hard about the requirements and the consequences of not meeting them correctly. Consider yourself warned.  File: python.info, Node: Why doesn’t list sort return the sorted list?, Next: How do you specify and enforce an interface spec in Python?, Prev: Why must dictionary keys be immutable?, Up: Design and History FAQ 11.3.21 Why doesn’t list.sort() return the sorted list? ------------------------------------------------------- In situations where performance matters, making a copy of the list just to sort it would be wasteful. Therefore, *note list.sort(): 445. sorts the list in place. In order to remind you of that fact, it does not return the sorted list. This way, you won’t be fooled into accidentally overwriting a list when you need a sorted copy but also need to keep the unsorted version around. If you want to return a new list, use the built-in *note sorted(): 444. function instead. This function creates a new list from a provided iterable, sorts it and returns it. For example, here’s how to iterate over the keys of a dictionary in sorted order: for key in sorted(mydict): ... # do whatever with mydict[key]...  File: python.info, Node: How do you specify and enforce an interface spec in Python?, Next: Why is there no goto?, Prev: Why doesn’t list sort return the sorted list?, Up: Design and History FAQ 11.3.22 How do you specify and enforce an interface spec in Python? ------------------------------------------------------------------- An interface specification for a module as provided by languages such as C++ and Java describes the prototypes for the methods and functions of the module. Many feel that compile-time enforcement of interface specifications helps in the construction of large programs. Python 2.6 adds an *note abc: 4. module that lets you define Abstract Base Classes (ABCs). You can then use *note isinstance(): 44f. and *note issubclass(): 450. to check whether an instance or a class implements a particular ABC. The *note collections.abc: 1f. module defines a set of useful ABCs such as *note Iterable: 1601, *note Container: 15ff, and *note MutableMapping: 9ef. For Python, many of the advantages of interface specifications can be obtained by an appropriate test discipline for components. A good test suite for a module can both provide a regression test and serve as a module interface specification and a set of examples. Many Python modules can be run as a script to provide a simple “self test.” Even modules which use complex external interfaces can often be tested in isolation using trivial “stub” emulations of the external interface. The *note doctest: 67. and *note unittest: 11b. modules or third-party test frameworks can be used to construct exhaustive test suites that exercise every line of code in a module. An appropriate testing discipline can help build large complex applications in Python as well as having interface specifications would. In fact, it can be better because an interface specification cannot test certain properties of a program. For example, the ‘append()’ method is expected to add new elements to the end of some internal list; an interface specification cannot test that your ‘append()’ implementation will actually do this correctly, but it’s trivial to check this property in a test suite. Writing test suites is very helpful, and you might want to design your code with an eye to making it easily tested. One increasingly popular technique, test-directed development, calls for writing parts of the test suite first, before you write any of the actual code. Of course Python allows you to be sloppy and not write test cases at all.  File: python.info, Node: Why is there no goto?, Next: Why can’t raw strings r-strings end with a backslash?, Prev: How do you specify and enforce an interface spec in Python?, Up: Design and History FAQ 11.3.23 Why is there no goto? ----------------------------- In the 1970s people realized that unrestricted goto could lead to messy “spaghetti” code that was hard to understand and revise. In a high-level language, it is also unneeded as long as there are ways to branch (in Python, with ‘if’ statements and ‘or’, ‘and’, and ‘if-else’ expressions) and loop (with ‘while’ and ‘for’ statements, possibly containing ‘continue’ and ‘break’). One can also use exceptions to provide a “structured goto” that works even across function calls. Many feel that exceptions can conveniently emulate all reasonable uses of the “go” or “goto” constructs of C, Fortran, and other languages. For example: class label(Exception): pass # declare a label try: ... if condition: raise label() # goto label ... except label: # where to goto pass ... This doesn’t allow you to jump into the middle of a loop, but that’s usually considered an abuse of goto anyway. Use sparingly.  File: python.info, Node: Why can’t raw strings r-strings end with a backslash?, Next: Why doesn’t Python have a “with” statement for attribute assignments?, Prev: Why is there no goto?, Up: Design and History FAQ 11.3.24 Why can’t raw strings (r-strings) end with a backslash? --------------------------------------------------------------- More precisely, they can’t end with an odd number of backslashes: the unpaired backslash at the end escapes the closing quote character, leaving an unterminated string. Raw strings were designed to ease creating input for processors (chiefly regular expression engines) that want to do their own backslash escape processing. Such processors consider an unmatched trailing backslash to be an error anyway, so raw strings disallow that. In return, they allow you to pass on the string quote character by escaping it with a backslash. These rules work well when r-strings are used for their intended purpose. If you’re trying to build Windows pathnames, note that all Windows system calls accept forward slashes too: f = open("/mydir/file.txt") # works fine! If you’re trying to build a pathname for a DOS command, try e.g. one of dir = r"\this\is\my\dos\dir" "\\" dir = r"\this\is\my\dos\dir\ "[:-1] dir = "\\this\\is\\my\\dos\\dir\\"  File: python.info, Node: Why doesn’t Python have a “with” statement for attribute assignments?, Next: Why are colons required for the if/while/def/class statements?, Prev: Why can’t raw strings r-strings end with a backslash?, Up: Design and History FAQ 11.3.25 Why doesn’t Python have a “with” statement for attribute assignments? ----------------------------------------------------------------------------- Python has a ‘with’ statement that wraps the execution of a block, calling code on the entrance and exit from the block. Some language have a construct that looks like this: with obj: a = 1 # equivalent to obj.a = 1 total = total + 1 # obj.total = obj.total + 1 In Python, such a construct would be ambiguous. Other languages, such as Object Pascal, Delphi, and C++, use static types, so it’s possible to know, in an unambiguous way, what member is being assigned to. This is the main point of static typing – the compiler `always' knows the scope of every variable at compile time. Python uses dynamic types. It is impossible to know in advance which attribute will be referenced at runtime. Member attributes may be added or removed from objects on the fly. This makes it impossible to know, from a simple reading, what attribute is being referenced: a local one, a global one, or a member attribute? For instance, take the following incomplete snippet: def foo(a): with a: print(x) The snippet assumes that “a” must have a member attribute called “x”. However, there is nothing in Python that tells the interpreter this. What should happen if “a” is, let us say, an integer? If there is a global variable named “x”, will it be used inside the with block? As you see, the dynamic nature of Python makes such choices much harder. The primary benefit of “with” and similar language features (reduction of code volume) can, however, easily be achieved in Python by assignment. Instead of: function(args).mydict[index][index].a = 21 function(args).mydict[index][index].b = 42 function(args).mydict[index][index].c = 63 write this: ref = function(args).mydict[index][index] ref.a = 21 ref.b = 42 ref.c = 63 This also has the side-effect of increasing execution speed because name bindings are resolved at run-time in Python, and the second version only needs to perform the resolution once.  File: python.info, Node: Why are colons required for the if/while/def/class statements?, Next: Why does Python allow commas at the end of lists and tuples?, Prev: Why doesn’t Python have a “with” statement for attribute assignments?, Up: Design and History FAQ 11.3.26 Why are colons required for the if/while/def/class statements? ---------------------------------------------------------------------- The colon is required primarily to enhance readability (one of the results of the experimental ABC language). Consider this: if a == b print(a) versus if a == b: print(a) Notice how the second one is slightly easier to read. Notice further how a colon sets off the example in this FAQ answer; it’s a standard usage in English. Another minor reason is that the colon makes it easier for editors with syntax highlighting; they can look for colons to decide when indentation needs to be increased instead of having to do a more elaborate parsing of the program text.  File: python.info, Node: Why does Python allow commas at the end of lists and tuples?, Prev: Why are colons required for the if/while/def/class statements?, Up: Design and History FAQ 11.3.27 Why does Python allow commas at the end of lists and tuples? -------------------------------------------------------------------- Python lets you add a trailing comma at the end of lists, tuples, and dictionaries: [1, 2, 3,] ('a', 'b', 'c',) d = { "A": [1, 5], "B": [6, 7], # last trailing comma is optional but good style } There are several reasons to allow this. When you have a literal value for a list, tuple, or dictionary spread across multiple lines, it’s easier to add more elements because you don’t have to remember to add a comma to the previous line. The lines can also be reordered without creating a syntax error. Accidentally omitting the comma can lead to errors that are hard to diagnose. For example: x = [ "fee", "fie" "foo", "fum" ] This list looks like it has four elements, but it actually contains three: “fee”, “fiefoo” and “fum”. Always adding the comma avoids this source of error. Allowing the trailing comma may also make programmatic code generation easier.  File: python.info, Node: Library and Extension FAQ, Next: Extending/Embedding FAQ, Prev: Design and History FAQ, Up: Python Frequently Asked Questions 11.4 Library and Extension FAQ ============================== * Menu: * General Library Questions:: * Common tasks:: * Threads:: * Input and Output: Input and Output<2>. * Network/Internet Programming:: * Databases:: * Mathematics and Numerics::  File: python.info, Node: General Library Questions, Next: Common tasks, Up: Library and Extension FAQ 11.4.1 General Library Questions -------------------------------- * Menu: * How do I find a module or application to perform task X?:: * Where is the math.py (socket.py, regex.py, etc.) source file?: Where is the math py socket py regex py etc source file?. * How do I make a Python script executable on Unix?:: * Is there a curses/termcap package for Python?:: * Is there an equivalent to C’s onexit() in Python?: Is there an equivalent to C’s onexit in Python?. * Why don’t my signal handlers work?::  File: python.info, Node: How do I find a module or application to perform task X?, Next: Where is the math py socket py regex py etc source file?, Up: General Library Questions 11.4.1.1 How do I find a module or application to perform task X? ................................................................. Check *note the Library Reference: e8e. to see if there’s a relevant standard library module. (Eventually you’ll learn what’s in the standard library and will be able to skip this step.) For third-party packages, search the Python Package Index(1) or try Google(2) or another Web search engine. Searching for “Python” plus a keyword or two for your topic of interest will usually find something helpful. ---------- Footnotes ---------- (1) https://pypi.org (2) https://www.google.com  File: python.info, Node: Where is the math py socket py regex py etc source file?, Next: How do I make a Python script executable on Unix?, Prev: How do I find a module or application to perform task X?, Up: General Library Questions 11.4.1.2 Where is the math.py (socket.py, regex.py, etc.) source file? ...................................................................... If you can’t find a source file for a module it may be a built-in or dynamically loaded module implemented in C, C++ or other compiled language. In this case you may not have the source file or it may be something like ‘mathmodule.c’, somewhere in a C source directory (not on the Python Path). There are (at least) three kinds of modules in Python: 1. modules written in Python (.py); 2. modules written in C and dynamically loaded (.dll, .pyd, .so, .sl, etc); 3. modules written in C and linked with the interpreter; to get a list of these, type: import sys print(sys.builtin_module_names)  File: python.info, Node: How do I make a Python script executable on Unix?, Next: Is there a curses/termcap package for Python?, Prev: Where is the math py socket py regex py etc source file?, Up: General Library Questions 11.4.1.3 How do I make a Python script executable on Unix? .......................................................... You need to do two things: the script file’s mode must be executable and the first line must begin with ‘#!’ followed by the path of the Python interpreter. The first is done by executing ‘chmod +x scriptfile’ or perhaps ‘chmod 755 scriptfile’. The second can be done in a number of ways. The most straightforward way is to write #!/usr/local/bin/python as the very first line of your file, using the pathname for where the Python interpreter is installed on your platform. If you would like the script to be independent of where the Python interpreter lives, you can use the ‘env’ program. Almost all Unix variants support the following, assuming the Python interpreter is in a directory on the user’s ‘PATH’: #!/usr/bin/env python `Don’t' do this for CGI scripts. The ‘PATH’ variable for CGI scripts is often very minimal, so you need to use the actual absolute pathname of the interpreter. Occasionally, a user’s environment is so full that the ‘/usr/bin/env’ program fails; or there’s no env program at all. In that case, you can try the following hack (due to Alex Rezinsky): #! /bin/sh """:" exec python $0 ${1+"$@"} """ The minor disadvantage is that this defines the script’s __doc__ string. However, you can fix that by adding __doc__ = """...Whatever..."""  File: python.info, Node: Is there a curses/termcap package for Python?, Next: Is there an equivalent to C’s onexit in Python?, Prev: How do I make a Python script executable on Unix?, Up: General Library Questions 11.4.1.4 Is there a curses/termcap package for Python? ...................................................... For Unix variants: The standard Python source distribution comes with a curses module in the Modules(1) subdirectory, though it’s not compiled by default. (Note that this is not available in the Windows distribution – there is no curses module for Windows.) The *note curses: 2c. module supports basic curses features as well as many additional functions from ncurses and SYSV curses such as colour, alternative character set support, pads, and mouse support. This means the module isn’t compatible with operating systems that only have BSD curses, but there don’t seem to be any currently maintained OSes that fall into this category. For Windows: use the consolelib module(2). ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Modules (2) http://effbot.org/zone/console-index.htm  File: python.info, Node: Is there an equivalent to C’s onexit in Python?, Next: Why don’t my signal handlers work?, Prev: Is there a curses/termcap package for Python?, Up: General Library Questions 11.4.1.5 Is there an equivalent to C’s onexit() in Python? .......................................................... The *note atexit: c. module provides a register function that is similar to C’s ‘onexit()’.  File: python.info, Node: Why don’t my signal handlers work?, Prev: Is there an equivalent to C’s onexit in Python?, Up: General Library Questions 11.4.1.6 Why don’t my signal handlers work? ........................................... The most common problem is that the signal handler is declared with the wrong argument list. It is called as handler(signum, frame) so it should be declared with two arguments: def handler(signum, frame): ...  File: python.info, Node: Common tasks, Next: Threads, Prev: General Library Questions, Up: Library and Extension FAQ 11.4.2 Common tasks ------------------- * Menu: * How do I test a Python program or component?:: * How do I create documentation from doc strings?:: * How do I get a single keypress at a time?::  File: python.info, Node: How do I test a Python program or component?, Next: How do I create documentation from doc strings?, Up: Common tasks 11.4.2.1 How do I test a Python program or component? ..................................................... Python comes with two testing frameworks. The *note doctest: 67. module finds examples in the docstrings for a module and runs them, comparing the output with the expected output given in the docstring. The *note unittest: 11b. module is a fancier testing framework modelled on Java and Smalltalk testing frameworks. To make testing easier, you should use good modular design in your program. Your program should have almost all functionality encapsulated in either functions or class methods – and this sometimes has the surprising and delightful effect of making the program run faster (because local variable accesses are faster than global accesses). Furthermore the program should avoid depending on mutating global variables, since this makes testing much more difficult to do. The “global main logic” of your program may be as simple as if __name__ == "__main__": main_logic() at the bottom of the main module of your program. Once your program is organized as a tractable collection of functions and class behaviours you should write test functions that exercise the behaviours. A test suite that automates a sequence of tests can be associated with each module. This sounds like a lot of work, but since Python is so terse and flexible it’s surprisingly easy. You can make coding much more pleasant and fun by writing your test functions in parallel with the “production code”, since this makes it easy to find bugs and even design flaws earlier. “Support modules” that are not intended to be the main module of a program may include a self-test of the module. if __name__ == "__main__": self_test() Even programs that interact with complex external interfaces may be tested when the external interfaces are unavailable by using “fake” interfaces implemented in Python.  File: python.info, Node: How do I create documentation from doc strings?, Next: How do I get a single keypress at a time?, Prev: How do I test a Python program or component?, Up: Common tasks 11.4.2.2 How do I create documentation from doc strings? ........................................................ The *note pydoc: d9. module can create HTML from the doc strings in your Python source code. An alternative for creating API documentation purely from docstrings is epydoc(1). Sphinx(2) can also include docstring content. ---------- Footnotes ---------- (1) http://epydoc.sourceforge.net/ (2) http://sphinx-doc.org  File: python.info, Node: How do I get a single keypress at a time?, Prev: How do I create documentation from doc strings?, Up: Common tasks 11.4.2.3 How do I get a single keypress at a time? .................................................. For Unix variants there are several solutions. It’s straightforward to do this using curses, but curses is a fairly large module to learn.  File: python.info, Node: Threads, Next: Input and Output<2>, Prev: Common tasks, Up: Library and Extension FAQ 11.4.3 Threads -------------- * Menu: * How do I program using threads?:: * None of my threads seem to run; why?: None of my threads seem to run why?. * How do I parcel out work among a bunch of worker threads?:: * What kinds of global value mutation are thread-safe?:: * Can’t we get rid of the Global Interpreter Lock?::  File: python.info, Node: How do I program using threads?, Next: None of my threads seem to run why?, Up: Threads 11.4.3.1 How do I program using threads? ........................................ Be sure to use the *note threading: 109. module and not the *note _thread: 3. module. The *note threading: 109. module builds convenient abstractions on top of the low-level primitives provided by the *note _thread: 3. module. Aahz has a set of slides from his threading tutorial that are helpful; see ‘http://www.pythoncraft.com/OSCON2001/’.  File: python.info, Node: None of my threads seem to run why?, Next: How do I parcel out work among a bunch of worker threads?, Prev: How do I program using threads?, Up: Threads 11.4.3.2 None of my threads seem to run: why? ............................................. As soon as the main thread exits, all threads are killed. Your main thread is running too quickly, giving the threads no time to do any work. A simple fix is to add a sleep to the end of the program that’s long enough for all the threads to finish: import threading, time def thread_task(name, n): for i in range(n): print(name, i) for i in range(10): T = threading.Thread(target=thread_task, args=(str(i), i)) T.start() time.sleep(10) # <---------------------------! But now (on many platforms) the threads don’t run in parallel, but appear to run sequentially, one at a time! The reason is that the OS thread scheduler doesn’t start a new thread until the previous thread is blocked. A simple fix is to add a tiny sleep to the start of the run function: def thread_task(name, n): time.sleep(0.001) # <--------------------! for i in range(n): print(name, i) for i in range(10): T = threading.Thread(target=thread_task, args=(str(i), i)) T.start() time.sleep(10) Instead of trying to guess a good delay value for *note time.sleep(): 680, it’s better to use some kind of semaphore mechanism. One idea is to use the *note queue: da. module to create a queue object, let each thread append a token to the queue when it finishes, and let the main thread read as many tokens from the queue as there are threads.  File: python.info, Node: How do I parcel out work among a bunch of worker threads?, Next: What kinds of global value mutation are thread-safe?, Prev: None of my threads seem to run why?, Up: Threads 11.4.3.3 How do I parcel out work among a bunch of worker threads? .................................................................. The easiest way is to use the new *note concurrent.futures: 22. module, especially the *note ThreadPoolExecutor: 27a. class. Or, if you want fine control over the dispatching algorithm, you can write your own logic manually. Use the *note queue: da. module to create a queue containing a list of jobs. The *note Queue: d18. class maintains a list of objects and has a ‘.put(obj)’ method that adds items to the queue and a ‘.get()’ method to return them. The class will take care of the locking necessary to ensure that each job is handed out exactly once. Here’s a trivial example: import threading, queue, time # The worker thread gets jobs off the queue. When the queue is empty, it # assumes there will be no more work and exits. # (Realistically workers will run until terminated.) def worker(): print('Running worker') time.sleep(0.1) while True: try: arg = q.get(block=False) except queue.Empty: print('Worker', threading.currentThread(), end=' ') print('queue empty') break else: print('Worker', threading.currentThread(), end=' ') print('running with argument', arg) time.sleep(0.5) # Create queue q = queue.Queue() # Start a pool of 5 workers for i in range(5): t = threading.Thread(target=worker, name='worker %i' % (i+1)) t.start() # Begin adding work to the queue for i in range(50): q.put(i) # Give threads time to run print('Main thread sleeping') time.sleep(5) When run, this will produce the following output: Running worker Running worker Running worker Running worker Running worker Main thread sleeping Worker running with argument 0 Worker running with argument 1 Worker running with argument 2 Worker running with argument 3 Worker running with argument 4 Worker running with argument 5 ... Consult the module’s documentation for more details; the *note Queue: d18. class provides a featureful interface.  File: python.info, Node: What kinds of global value mutation are thread-safe?, Next: Can’t we get rid of the Global Interpreter Lock?, Prev: How do I parcel out work among a bunch of worker threads?, Up: Threads 11.4.3.4 What kinds of global value mutation are thread-safe? ............................................................. A *note global interpreter lock: 506. (GIL) is used internally to ensure that only one thread runs in the Python VM at a time. In general, Python offers to switch among threads only between bytecode instructions; how frequently it switches can be set via *note sys.setswitchinterval(): beb. Each bytecode instruction and therefore all the C implementation code reached from each instruction is therefore atomic from the point of view of a Python program. In theory, this means an exact accounting requires an exact understanding of the PVM bytecode implementation. In practice, it means that operations on shared variables of built-in data types (ints, lists, dicts, etc) that “look atomic” really are. For example, the following operations are all atomic (L, L1, L2 are lists, D, D1, D2 are dicts, x, y are objects, i, j are ints): L.append(x) L1.extend(L2) x = L[i] x = L.pop() L1[i:j] = L2 L.sort() x = y x.field = y D[x] = y D1.update(D2) D.keys() These aren’t: i = i+1 L.append(L[-1]) L[i] = L[j] D[x] = D[x] + 1 Operations that replace other objects may invoke those other objects’ *note __del__(): 91f. method when their reference count reaches zero, and that can affect things. This is especially true for the mass updates to dictionaries and lists. When in doubt, use a mutex!  File: python.info, Node: Can’t we get rid of the Global Interpreter Lock?, Prev: What kinds of global value mutation are thread-safe?, Up: Threads 11.4.3.5 Can’t we get rid of the Global Interpreter Lock? ......................................................... The *note global interpreter lock: 506. (GIL) is often seen as a hindrance to Python’s deployment on high-end multiprocessor server machines, because a multi-threaded Python program effectively only uses one CPU, due to the insistence that (almost) all Python code can only run while the GIL is held. Back in the days of Python 1.5, Greg Stein actually implemented a comprehensive patch set (the “free threading” patches) that removed the GIL and replaced it with fine-grained locking. Adam Olsen recently did a similar experiment in his python-safethread(1) project. Unfortunately, both experiments exhibited a sharp drop in single-thread performance (at least 30% slower), due to the amount of fine-grained locking necessary to compensate for the removal of the GIL. This doesn’t mean that you can’t make good use of Python on multi-CPU machines! You just have to be creative with dividing the work up between multiple `processes' rather than multiple `threads'. The *note ProcessPoolExecutor: 2a4. class in the new *note concurrent.futures: 22. module provides an easy way of doing so; the *note multiprocessing: b7. module provides a lower-level API in case you want more control over dispatching of tasks. Judicious use of C extensions will also help; if you use a C extension to perform a time-consuming task, the extension can release the GIL while the thread of execution is in the C code and allow other threads to get some work done. Some standard library modules such as *note zlib: 144. and *note hashlib: 8d. already do this. It has been suggested that the GIL should be a per-interpreter-state lock rather than truly global; interpreters then wouldn’t be able to share objects. Unfortunately, this isn’t likely to happen either. It would be a tremendous amount of work, because many object implementations currently have global state. For example, small integers and short strings are cached; these caches would have to be moved to the interpreter state. Other object types have their own free list; these free lists would have to be moved to the interpreter state. And so on. And I doubt that it can even be done in finite time, because the same problem exists for 3rd party extensions. It is likely that 3rd party extensions are being written at a faster rate than you can convert them to store all their global state in the interpreter state. And finally, once you have multiple interpreters not sharing any state, what have you gained over running each interpreter in a separate process? ---------- Footnotes ---------- (1) https://code.google.com/archive/p/python-safethread  File: python.info, Node: Input and Output<2>, Next: Network/Internet Programming, Prev: Threads, Up: Library and Extension FAQ 11.4.4 Input and Output ----------------------- * Menu: * How do I delete a file? (And other file questions…): How do I delete a file? And other file questions…. * How do I copy a file?:: * How do I read (or write) binary data?: How do I read or write binary data?. * I can’t seem to use os.read() on a pipe created with os.popen(); why?: I can’t seem to use os read on a pipe created with os popen ; why?. * How do I access the serial (RS232) port?: How do I access the serial RS232 port?. * Why doesn’t closing sys.stdout (stdin, stderr) really close it?: Why doesn’t closing sys stdout stdin stderr really close it?.  File: python.info, Node: How do I delete a file? And other file questions…, Next: How do I copy a file?, Up: Input and Output<2> 11.4.4.1 How do I delete a file? (And other file questions…) ............................................................ Use ‘os.remove(filename)’ or ‘os.unlink(filename)’; for documentation, see the *note os: c4. module. The two functions are identical; *note unlink(): a3c. is simply the name of the Unix system call for this function. To remove a directory, use *note os.rmdir(): a3a.; use *note os.mkdir(): a36. to create one. ‘os.makedirs(path)’ will create any intermediate directories in ‘path’ that don’t exist. ‘os.removedirs(path)’ will remove intermediate directories as long as they’re empty; if you want to delete an entire directory tree and its contents, use *note shutil.rmtree(): 21c. To rename a file, use ‘os.rename(old_path, new_path)’. To truncate a file, open it using ‘f = open(filename, "rb+")’, and use ‘f.truncate(offset)’; offset defaults to the current seek position. There’s also ‘os.ftruncate(fd, offset)’ for files opened with *note os.open(): 665, where `fd' is the file descriptor (a small integer). The *note shutil: e9. module also contains a number of functions to work on files including *note copyfile(): 258, *note copytree(): 21a, and *note rmtree(): 21c.  File: python.info, Node: How do I copy a file?, Next: How do I read or write binary data?, Prev: How do I delete a file? And other file questions…, Up: Input and Output<2> 11.4.4.2 How do I copy a file? .............................. The *note shutil: e9. module contains a *note copyfile(): 258. function. Note that on MacOS 9 it doesn’t copy the resource fork and Finder info.  File: python.info, Node: How do I read or write binary data?, Next: I can’t seem to use os read on a pipe created with os popen ; why?, Prev: How do I copy a file?, Up: Input and Output<2> 11.4.4.3 How do I read (or write) binary data? .............................................. To read or write complex binary data formats, it’s best to use the *note struct: f8. module. It allows you to take a string containing binary data (usually numbers) and convert it to Python objects; and vice versa. For example, the following code reads two 2-byte integers and one 4-byte integer in big-endian format from a file: import struct with open(filename, "rb") as f: s = f.read(8) x, y, z = struct.unpack(">hhl", s) The ‘>’ in the format string forces big-endian data; the letter ‘h’ reads one “short integer” (2 bytes), and ‘l’ reads one “long integer” (4 bytes) from the string. For data that is more regular (e.g. a homogeneous list of ints or floats), you can also use the *note array: 7. module. Note: To read and write binary data, it is mandatory to open the file in binary mode (here, passing ‘"rb"’ to *note open(): 4f0.). If you use ‘"r"’ instead (the default), the file will be open in text mode and ‘f.read()’ will return *note str: 330. objects rather than *note bytes: 331. objects.  File: python.info, Node: I can’t seem to use os read on a pipe created with os popen ; why?, Next: How do I access the serial RS232 port?, Prev: How do I read or write binary data?, Up: Input and Output<2> 11.4.4.4 I can’t seem to use os.read() on a pipe created with os.popen(); why? .............................................................................. *note os.read(): 668. is a low-level function which takes a file descriptor, a small integer representing the opened file. *note os.popen(): 2a9. creates a high-level file object, the same type returned by the built-in *note open(): 4f0. function. Thus, to read `n' bytes from a pipe `p' created with *note os.popen(): 2a9, you need to use ‘p.read(n)’.  File: python.info, Node: How do I access the serial RS232 port?, Next: Why doesn’t closing sys stdout stdin stderr really close it?, Prev: I can’t seem to use os read on a pipe created with os popen ; why?, Up: Input and Output<2> 11.4.4.5 How do I access the serial (RS232) port? ................................................. For Win32, POSIX (Linux, BSD, etc.), Jython: ‘http://pyserial.sourceforge.net’ For Unix, see a Usenet post by Mitch Chapman: ‘https://groups.google.com/groups?selm=34A04430.CF9@ohioee.com’  File: python.info, Node: Why doesn’t closing sys stdout stdin stderr really close it?, Prev: How do I access the serial RS232 port?, Up: Input and Output<2> 11.4.4.6 Why doesn’t closing sys.stdout (stdin, stderr) really close it? ........................................................................ Python *note file objects: b42. are a high-level layer of abstraction on low-level C file descriptors. For most file objects you create in Python via the built-in *note open(): 4f0. function, ‘f.close()’ marks the Python file object as being closed from Python’s point of view, and also arranges to close the underlying C file descriptor. This also happens automatically in ‘f’’s destructor, when ‘f’ becomes garbage. But stdin, stdout and stderr are treated specially by Python, because of the special status also given to them by C. Running ‘sys.stdout.close()’ marks the Python-level file object as being closed, but does `not' close the associated C file descriptor. To close the underlying C file descriptor for one of these three, you should first be sure that’s what you really want to do (e.g., you may confuse extension modules trying to do I/O). If it is, use *note os.close(): 3d2.: os.close(stdin.fileno()) os.close(stdout.fileno()) os.close(stderr.fileno()) Or you can use the numeric constants 0, 1 and 2, respectively.  File: python.info, Node: Network/Internet Programming, Next: Databases, Prev: Input and Output<2>, Up: Library and Extension FAQ 11.4.5 Network/Internet Programming ----------------------------------- * Menu: * What WWW tools are there for Python?:: * How can I mimic CGI form submission (METHOD=POST)?: How can I mimic CGI form submission METHOD=POST ?. * What module should I use to help with generating HTML?:: * How do I send mail from a Python script?:: * How do I avoid blocking in the connect() method of a socket?: How do I avoid blocking in the connect method of a socket?.  File: python.info, Node: What WWW tools are there for Python?, Next: How can I mimic CGI form submission METHOD=POST ?, Up: Network/Internet Programming 11.4.5.1 What WWW tools are there for Python? ............................................. See the chapters titled *note Internet Protocols and Support: 28cd. and *note Internet Data Handling: 24ca. in the Library Reference Manual. Python has many modules that will help you build server-side and client-side web systems. A summary of available frameworks is maintained by Paul Boddie at ‘https://wiki.python.org/moin/WebProgramming’. Cameron Laird maintains a useful set of pages about Python web technologies at ‘http://phaseit.net/claird/comp.lang.python/web_python’.  File: python.info, Node: How can I mimic CGI form submission METHOD=POST ?, Next: What module should I use to help with generating HTML?, Prev: What WWW tools are there for Python?, Up: Network/Internet Programming 11.4.5.2 How can I mimic CGI form submission (METHOD=POST)? ........................................................... I would like to retrieve web pages that are the result of POSTing a form. Is there existing code that would let me do this easily? Yes. Here’s a simple example that uses urllib.request: #!/usr/local/bin/python import urllib.request # build the query string qs = "First=Josephine&MI=Q&Last=Public" # connect and send the server a path req = urllib.request.urlopen('http://www.some-server.out-there' '/cgi-bin/some-cgi-script', data=qs) with req: msg, hdrs = req.read(), req.info() Note that in general for percent-encoded POST operations, query strings must be quoted using *note urllib.parse.urlencode(): 78b. For example, to send ‘name=Guy Steele, Jr.’: >>> import urllib.parse >>> urllib.parse.urlencode({'name': 'Guy Steele, Jr.'}) 'name=Guy+Steele%2C+Jr.' See also ........ *note HOWTO Fetch Internet Resources Using The urllib Package: 29b5. for extensive examples.  File: python.info, Node: What module should I use to help with generating HTML?, Next: How do I send mail from a Python script?, Prev: How can I mimic CGI form submission METHOD=POST ?, Up: Network/Internet Programming 11.4.5.3 What module should I use to help with generating HTML? ............................................................... You can find a collection of useful links on the Web Programming wiki page(1). ---------- Footnotes ---------- (1) https://wiki.python.org/moin/WebProgramming  File: python.info, Node: How do I send mail from a Python script?, Next: How do I avoid blocking in the connect method of a socket?, Prev: What module should I use to help with generating HTML?, Up: Network/Internet Programming 11.4.5.4 How do I send mail from a Python script? ................................................. Use the standard library module *note smtplib: ed. Here’s a very simple interactive mail sender that uses it. This method will work on any host that supports an SMTP listener. import sys, smtplib fromaddr = input("From: ") toaddrs = input("To: ").split(',') print("Enter message, end with ^D:") msg = '' while True: line = sys.stdin.readline() if not line: break msg += line # The actual mail send server = smtplib.SMTP('localhost') server.sendmail(fromaddr, toaddrs, msg) server.quit() A Unix-only alternative uses sendmail. The location of the sendmail program varies between systems; sometimes it is ‘/usr/lib/sendmail’, sometimes ‘/usr/sbin/sendmail’. The sendmail manual page will help you out. Here’s some sample code: import os SENDMAIL = "/usr/sbin/sendmail" # sendmail location p = os.popen("%s -t -i" % SENDMAIL, "w") p.write("To: receiver@example.com\n") p.write("Subject: test\n") p.write("\n") # blank line separating headers from body p.write("Some text\n") p.write("some more text\n") sts = p.close() if sts != 0: print("Sendmail exit status", sts)  File: python.info, Node: How do I avoid blocking in the connect method of a socket?, Prev: How do I send mail from a Python script?, Up: Network/Internet Programming 11.4.5.5 How do I avoid blocking in the connect() method of a socket? ..................................................................... The *note select: e5. module is commonly used to help with asynchronous I/O on sockets. To prevent the TCP connect from blocking, you can set the socket to non-blocking mode. Then when you do the ‘connect()’, you will either connect immediately (unlikely) or get an exception that contains the error number as ‘.errno’. ‘errno.EINPROGRESS’ indicates that the connection is in progress, but hasn’t finished yet. Different OSes will return different values, so you’re going to have to check what’s returned on your system. You can use the ‘connect_ex()’ method to avoid creating an exception. It will just return the errno value. To poll, you can call ‘connect_ex()’ again later – ‘0’ or ‘errno.EISCONN’ indicate that you’re connected – or you can pass this socket to select to check if it’s writable. Note: The *note asyncore: b. module presents a framework-like approach to the problem of writing non-blocking networking code. The third-party Twisted(1) library is a popular and feature-rich alternative. ---------- Footnotes ---------- (1) https://twistedmatrix.com/trac/  File: python.info, Node: Databases, Next: Mathematics and Numerics, Prev: Network/Internet Programming, Up: Library and Extension FAQ 11.4.6 Databases ---------------- * Menu: * Are there any interfaces to database packages in Python?:: * How do you implement persistent objects in Python?::  File: python.info, Node: Are there any interfaces to database packages in Python?, Next: How do you implement persistent objects in Python?, Up: Databases 11.4.6.1 Are there any interfaces to database packages in Python? ................................................................. Yes. Interfaces to disk-based hashes such as *note DBM: 35. and *note GDBM: 34. are also included with standard Python. There is also the *note sqlite3: f2. module, which provides a lightweight disk-based relational database. Support for most relational databases is available. See the DatabaseProgramming wiki page(1) for details. ---------- Footnotes ---------- (1) https://wiki.python.org/moin/DatabaseProgramming  File: python.info, Node: How do you implement persistent objects in Python?, Prev: Are there any interfaces to database packages in Python?, Up: Databases 11.4.6.2 How do you implement persistent objects in Python? ........................................................... The *note pickle: ca. library module solves this in a very general way (though you still can’t store things like open files, sockets or windows), and the *note shelve: e7. library module uses pickle and (g)dbm to create persistent mappings containing arbitrary Python objects.  File: python.info, Node: Mathematics and Numerics, Prev: Databases, Up: Library and Extension FAQ 11.4.7 Mathematics and Numerics ------------------------------- * Menu: * How do I generate random numbers in Python?::  File: python.info, Node: How do I generate random numbers in Python?, Up: Mathematics and Numerics 11.4.7.1 How do I generate random numbers in Python? .................................................... The standard module *note random: dc. implements a random number generator. Usage is simple: import random random.random() This returns a random floating point number in the range [0, 1). There are also many other specialized generators in this module, such as: * ‘randrange(a, b)’ chooses an integer in the range [a, b). * ‘uniform(a, b)’ chooses a floating point number in the range [a, b). * ‘normalvariate(mean, sdev)’ samples the normal (Gaussian) distribution. Some higher-level functions operate on sequences directly, such as: * ‘choice(S)’ chooses random element from a given sequence * ‘shuffle(L)’ shuffles a list in-place, i.e. permutes it randomly There’s also a ‘Random’ class you can instantiate to create independent multiple random number generators.  File: python.info, Node: Extending/Embedding FAQ, Next: Python on Windows FAQ, Prev: Library and Extension FAQ, Up: Python Frequently Asked Questions 11.5 Extending/Embedding FAQ ============================ * Menu: * Can I create my own functions in C?:: * Can I create my own functions in C++?:: * Writing C is hard; are there any alternatives?:: * How can I execute arbitrary Python statements from C?:: * How can I evaluate an arbitrary Python expression from C?:: * How do I extract C values from a Python object?:: * How do I use Py_BuildValue() to create a tuple of arbitrary length?: How do I use Py_BuildValue to create a tuple of arbitrary length?. * How do I call an object’s method from C?:: * How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?. * How do I access a module written in Python from C?:: * How do I interface to C++ objects from Python?:: * I added a module using the Setup file and the make fails; why?:: * How do I debug an extension?:: * I want to compile a Python module on my Linux system, but some files are missing. Why?: I want to compile a Python module on my Linux system but some files are missing Why?. * How do I tell “incomplete input” from “invalid input”?:: * How do I find undefined g++ symbols __builtin_new or __pure_virtual?:: * Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?.  File: python.info, Node: Can I create my own functions in C?, Next: Can I create my own functions in C++?, Up: Extending/Embedding FAQ 11.5.1 Can I create my own functions in C? ------------------------------------------ Yes, you can create built-in modules containing functions, variables, exceptions and even new types in C. This is explained in the document *note Extending and Embedding the Python Interpreter: e90. Most intermediate or advanced Python books will also cover this topic.  File: python.info, Node: Can I create my own functions in C++?, Next: Writing C is hard; are there any alternatives?, Prev: Can I create my own functions in C?, Up: Extending/Embedding FAQ 11.5.2 Can I create my own functions in C++? -------------------------------------------- Yes, using the C compatibility features found in C++. Place ‘extern "C" { ... }’ around the Python include files and put ‘extern "C"’ before each function that is going to be called by the Python interpreter. Global or static C++ objects with constructors are probably not a good idea.  File: python.info, Node: Writing C is hard; are there any alternatives?, Next: How can I execute arbitrary Python statements from C?, Prev: Can I create my own functions in C++?, Up: Extending/Embedding FAQ 11.5.3 Writing C is hard; are there any alternatives? ----------------------------------------------------- There are a number of alternatives to writing your own C extensions, depending on what you’re trying to do. Cython(1) and its relative Pyrex(2) are compilers that accept a slightly modified form of Python and generate the corresponding C code. Cython and Pyrex make it possible to write an extension without having to learn Python’s C API. If you need to interface to some C or C++ library for which no Python extension currently exists, you can try wrapping the library’s data types and functions with a tool such as SWIG(3). SIP(4), CXX(5) Boost(6), or Weave(7) are also alternatives for wrapping C++ libraries. ---------- Footnotes ---------- (1) http://cython.org (2) https://www.cosc.canterbury.ac.nz/greg.ewing/python/Pyrex/ (3) http://www.swig.org (4) https://riverbankcomputing.com/software/sip/intro (5) http://cxx.sourceforge.net/ (6) http://www.boost.org/libs/python/doc/index.html (7) https://github.com/scipy/weave  File: python.info, Node: How can I execute arbitrary Python statements from C?, Next: How can I evaluate an arbitrary Python expression from C?, Prev: Writing C is hard; are there any alternatives?, Up: Extending/Embedding FAQ 11.5.4 How can I execute arbitrary Python statements from C? ------------------------------------------------------------ The highest-level function to do this is *note PyRun_SimpleString(): 38c8. which takes a single string argument to be executed in the context of the module ‘__main__’ and returns ‘0’ for success and ‘-1’ when an exception occurred (including *note SyntaxError: 458.). If you want more control, use *note PyRun_String(): 391b.; see the source for *note PyRun_SimpleString(): 38c8. in ‘Python/pythonrun.c’.  File: python.info, Node: How can I evaluate an arbitrary Python expression from C?, Next: How do I extract C values from a Python object?, Prev: How can I execute arbitrary Python statements from C?, Up: Extending/Embedding FAQ 11.5.5 How can I evaluate an arbitrary Python expression from C? ---------------------------------------------------------------- Call the function *note PyRun_String(): 391b. from the previous question with the start symbol *note Py_eval_input: 3929.; it parses an expression, evaluates it and returns its value.  File: python.info, Node: How do I extract C values from a Python object?, Next: How do I use Py_BuildValue to create a tuple of arbitrary length?, Prev: How can I evaluate an arbitrary Python expression from C?, Up: Extending/Embedding FAQ 11.5.6 How do I extract C values from a Python object? ------------------------------------------------------ That depends on the object’s type. If it’s a tuple, *note PyTuple_Size(): 3b99. returns its length and *note PyTuple_GetItem(): 385c. returns the item at a specified index. Lists have similar functions, ‘PyListSize()’ and *note PyList_GetItem(): 385d. For bytes, *note PyBytes_Size(): 3b20. returns its length and *note PyBytes_AsStringAndSize(): 3b24. provides a pointer to its value and its length. Note that Python bytes objects may contain null bytes so C’s ‘strlen()’ should not be used. To test the type of an object, first make sure it isn’t ‘NULL’, and then use *note PyBytes_Check(): d1f, *note PyTuple_Check(): 3b95, *note PyList_Check(): 3baa, etc. There is also a high-level API to Python objects which is provided by the so-called ‘abstract’ interface – read ‘Include/abstract.h’ for further details. It allows interfacing with any kind of Python sequence using calls like *note PySequence_Length(): 3a47, *note PySequence_GetItem(): 38f6, etc. as well as many other useful protocols such as numbers (*note PyNumber_Index(): 3a3e. et al.) and mappings in the PyMapping APIs.  File: python.info, Node: How do I use Py_BuildValue to create a tuple of arbitrary length?, Next: How do I call an object’s method from C?, Prev: How do I extract C values from a Python object?, Up: Extending/Embedding FAQ 11.5.7 How do I use Py_BuildValue() to create a tuple of arbitrary length? -------------------------------------------------------------------------- You can’t. Use *note PyTuple_Pack(): 3b98. instead.  File: python.info, Node: How do I call an object’s method from C?, Next: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?, Prev: How do I use Py_BuildValue to create a tuple of arbitrary length?, Up: Extending/Embedding FAQ 11.5.8 How do I call an object’s method from C? ----------------------------------------------- The *note PyObject_CallMethod(): 3a0e. function can be used to call an arbitrary method of an object. The parameters are the object, the name of the method to call, a format string like that used with *note Py_BuildValue(): 2ce, and the argument values: PyObject * PyObject_CallMethod(PyObject *object, const char *method_name, const char *arg_format, ...); This works for any object that has methods – whether built-in or user-defined. You are responsible for eventually *note Py_DECREF(): 266.’ing the return value. To call, e.g., a file object’s “seek” method with arguments 10, 0 (assuming the file object pointer is “f”): res = PyObject_CallMethod(f, "seek", "(ii)", 10, 0); if (res == NULL) { ... an exception occurred ... } else { Py_DECREF(res); } Note that since *note PyObject_CallObject(): 384f. `always' wants a tuple for the argument list, to call a function without arguments, pass “()” for the format, and to call a function with one argument, surround the argument in parentheses, e.g. “(i)”.  File: python.info, Node: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?, Next: How do I access a module written in Python from C?, Prev: How do I call an object’s method from C?, Up: Extending/Embedding FAQ 11.5.9 How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)? ----------------------------------------------------------------------------------------------- In Python code, define an object that supports the ‘write()’ method. Assign this object to *note sys.stdout: 30e. and *note sys.stderr: 30f. Call print_error, or just allow the standard traceback mechanism to work. Then, the output will go wherever your ‘write()’ method sends it. The easiest way to do this is to use the *note io.StringIO: 82d. class: >>> import io, sys >>> sys.stdout = io.StringIO() >>> print('foo') >>> print('hello world!') >>> sys.stderr.write(sys.stdout.getvalue()) foo hello world! A custom object to do the same would look like this: >>> import io, sys >>> class StdoutCatcher(io.TextIOBase): ... def __init__(self): ... self.data = [] ... def write(self, stuff): ... self.data.append(stuff) ... >>> import sys >>> sys.stdout = StdoutCatcher() >>> print('foo') >>> print('hello world!') >>> sys.stderr.write(''.join(sys.stdout.data)) foo hello world!  File: python.info, Node: How do I access a module written in Python from C?, Next: How do I interface to C++ objects from Python?, Prev: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?, Up: Extending/Embedding FAQ 11.5.10 How do I access a module written in Python from C? ---------------------------------------------------------- You can get a pointer to the module object as follows: module = PyImport_ImportModule(""); If the module hasn’t been imported yet (i.e. it is not yet present in *note sys.modules: 1152.), this initializes the module; otherwise it simply returns the value of ‘sys.modules[""]’. Note that it doesn’t enter the module into any namespace – it only ensures it has been initialized and is stored in *note sys.modules: 1152. You can then access the module’s attributes (i.e. any name defined in the module) as follows: attr = PyObject_GetAttrString(module, ""); Calling *note PyObject_SetAttrString(): 3a05. to assign to variables in the module also works.  File: python.info, Node: How do I interface to C++ objects from Python?, Next: I added a module using the Setup file and the make fails; why?, Prev: How do I access a module written in Python from C?, Up: Extending/Embedding FAQ 11.5.11 How do I interface to C++ objects from Python? ------------------------------------------------------ Depending on your requirements, there are many approaches. To do this manually, begin by reading *note the “Extending and Embedding” document: e90. Realize that for the Python run-time system, there isn’t a whole lot of difference between C and C++ – so the strategy of building a new Python type around a C structure (pointer) type will also work for C++ objects. For C++ libraries, see *note Writing C is hard; are there any alternatives?: 4035.  File: python.info, Node: I added a module using the Setup file and the make fails; why?, Next: How do I debug an extension?, Prev: How do I interface to C++ objects from Python?, Up: Extending/Embedding FAQ 11.5.12 I added a module using the Setup file and the make fails; why? ---------------------------------------------------------------------- Setup must end in a newline, if there is no newline there, the build process fails. (Fixing this requires some ugly shell script hackery, and this bug is so minor that it doesn’t seem worth the effort.)  File: python.info, Node: How do I debug an extension?, Next: I want to compile a Python module on my Linux system but some files are missing Why?, Prev: I added a module using the Setup file and the make fails; why?, Up: Extending/Embedding FAQ 11.5.13 How do I debug an extension? ------------------------------------ When using GDB with dynamically loaded extensions, you can’t set a breakpoint in your extension until your extension is loaded. In your ‘.gdbinit’ file (or interactively), add the command: br _PyImport_LoadDynamicModule Then, when you run GDB: $ gdb /local/bin/python gdb) run myscript.py gdb) continue # repeat until your extension is loaded gdb) finish # so that your extension is loaded gdb) br myfunction.c:50 gdb) continue  File: python.info, Node: I want to compile a Python module on my Linux system but some files are missing Why?, Next: How do I tell “incomplete input” from “invalid input”?, Prev: How do I debug an extension?, Up: Extending/Embedding FAQ 11.5.14 I want to compile a Python module on my Linux system, but some files are missing. Why? ---------------------------------------------------------------------------------------------- Most packaged versions of Python don’t include the ‘/usr/lib/python2.`x'/config/’ directory, which contains various files required for compiling Python extensions. For Red Hat, install the python-devel RPM to get the necessary files. For Debian, run ‘apt-get install python-dev’.  File: python.info, Node: How do I tell “incomplete input” from “invalid input”?, Next: How do I find undefined g++ symbols __builtin_new or __pure_virtual?, Prev: I want to compile a Python module on my Linux system but some files are missing Why?, Up: Extending/Embedding FAQ 11.5.15 How do I tell “incomplete input” from “invalid input”? -------------------------------------------------------------- Sometimes you want to emulate the Python interactive interpreter’s behavior, where it gives you a continuation prompt when the input is incomplete (e.g. you typed the start of an “if” statement or you didn’t close your parentheses or triple string quotes), but it gives you a syntax error message immediately when the input is invalid. In Python you can use the *note codeop: 1d. module, which approximates the parser’s behavior sufficiently. IDLE uses this, for example. The easiest way to do it in C is to call *note PyRun_InteractiveLoop(): 390e. (perhaps in a separate thread) and let the Python interpreter handle the input for you. You can also set the *note PyOS_ReadlineFunctionPointer(): 96c. to point at your custom input function. See ‘Modules/readline.c’ and ‘Parser/myreadline.c’ for more hints. However sometimes you have to run the embedded Python interpreter in the same thread as your rest application and you can’t allow the *note PyRun_InteractiveLoop(): 390e. to stop while waiting for user input. The one solution then is to call ‘PyParser_ParseString()’ and test for ‘e.error’ equal to ‘E_EOF’, which means the input is incomplete. Here’s a sample code fragment, untested, inspired by code from Alex Farber: #define PY_SSIZE_T_CLEAN #include #include #include #include #include #include int testcomplete(char *code) /* code should end in \n */ /* return -1 for error, 0 for incomplete, 1 for complete */ { node *n; perrdetail e; n = PyParser_ParseString(code, &_PyParser_Grammar, Py_file_input, &e); if (n == NULL) { if (e.error == E_EOF) return 0; return -1; } PyNode_Free(n); return 1; } Another solution is trying to compile the received string with *note Py_CompileString(): 3921. If it compiles without errors, try to execute the returned code object by calling *note PyEval_EvalCode(): 3925. Otherwise save the input for later. If the compilation fails, find out if it’s an error or just more input is required - by extracting the message string from the exception tuple and comparing it to the string “unexpected EOF while parsing”. Here is a complete example using the GNU readline library (you may want to ignore `SIGINT' while calling readline()): #include #include #define PY_SSIZE_T_CLEAN #include #include #include #include int main (int argc, char* argv[]) { int i, j, done = 0; /* lengths of line, code */ char ps1[] = ">>> "; char ps2[] = "... "; char *prompt = ps1; char *msg, *line, *code = NULL; PyObject *src, *glb, *loc; PyObject *exc, *val, *trb, *obj, *dum; Py_Initialize (); loc = PyDict_New (); glb = PyDict_New (); PyDict_SetItemString (glb, "__builtins__", PyEval_GetBuiltins ()); while (!done) { line = readline (prompt); if (NULL == line) /* Ctrl-D pressed */ { done = 1; } else { i = strlen (line); if (i > 0) add_history (line); /* save non-empty lines */ if (NULL == code) /* nothing in code yet */ j = 0; else j = strlen (code); code = realloc (code, i + j + 2); if (NULL == code) /* out of memory */ exit (1); if (0 == j) /* code was empty, so */ code[0] = '\0'; /* keep strncat happy */ strncat (code, line, i); /* append line to code */ code[i + j] = '\n'; /* append '\n' to code */ code[i + j + 1] = '\0'; src = Py_CompileString (code, "", Py_single_input); if (NULL != src) /* compiled just fine - */ { if (ps1 == prompt || /* ">>> " or */ '\n' == code[i + j - 1]) /* "... " and double '\n' */ { /* so execute it */ dum = PyEval_EvalCode (src, glb, loc); Py_XDECREF (dum); Py_XDECREF (src); free (code); code = NULL; if (PyErr_Occurred ()) PyErr_Print (); prompt = ps1; } } /* syntax error or E_EOF? */ else if (PyErr_ExceptionMatches (PyExc_SyntaxError)) { PyErr_Fetch (&exc, &val, &trb); /* clears exception! */ if (PyArg_ParseTuple (val, "sO", &msg, &obj) && !strcmp (msg, "unexpected EOF while parsing")) /* E_EOF */ { Py_XDECREF (exc); Py_XDECREF (val); Py_XDECREF (trb); prompt = ps2; } else /* some other syntax error */ { PyErr_Restore (exc, val, trb); PyErr_Print (); free (code); code = NULL; prompt = ps1; } } else /* some non-syntax error */ { PyErr_Print (); free (code); code = NULL; prompt = ps1; } free (line); } } Py_XDECREF(glb); Py_XDECREF(loc); Py_Finalize(); exit(0); }  File: python.info, Node: How do I find undefined g++ symbols __builtin_new or __pure_virtual?, Next: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?, Prev: How do I tell “incomplete input” from “invalid input”?, Up: Extending/Embedding FAQ 11.5.16 How do I find undefined g++ symbols __builtin_new or __pure_virtual? ---------------------------------------------------------------------------- To dynamically load g++ extension modules, you must recompile Python, relink it using g++ (change LINKCC in the Python Modules Makefile), and link your extension module using g++ (e.g., ‘g++ -shared -o mymodule.so mymodule.o’).  File: python.info, Node: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?, Prev: How do I find undefined g++ symbols __builtin_new or __pure_virtual?, Up: Extending/Embedding FAQ 11.5.17 Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)? ------------------------------------------------------------------------------------------------------------------------ Yes, you can inherit from built-in classes such as *note int: 184, *note list: 262, *note dict: 1b8, etc. The Boost Python Library (BPL, ‘http://www.boost.org/libs/python/doc/index.html’) provides a way of doing this from C++ (i.e. you can inherit from an extension class written in C++ using the BPL).  File: python.info, Node: Python on Windows FAQ, Next: Graphic User Interface FAQ, Prev: Extending/Embedding FAQ, Up: Python Frequently Asked Questions 11.6 Python on Windows FAQ ========================== * Menu: * How do I run a Python program under Windows?:: * How do I make Python scripts executable?:: * Why does Python sometimes take so long to start?:: * How do I make an executable from a Python script?:: * Is a *.pyd file the same as a DLL?: Is a * pyd file the same as a DLL?. * How can I embed Python into a Windows application?:: * How do I keep editors from inserting tabs into my Python source?:: * How do I check for a keypress without blocking?::  File: python.info, Node: How do I run a Python program under Windows?, Next: How do I make Python scripts executable?, Up: Python on Windows FAQ 11.6.1 How do I run a Python program under Windows? --------------------------------------------------- This is not necessarily a straightforward question. If you are already familiar with running programs from the Windows command line then everything will seem obvious; otherwise, you might need a little more guidance. Unless you use some sort of integrated development environment, you will end up `typing' Windows commands into what is variously referred to as a “DOS window” or “Command prompt window”. Usually you can create such a window from your search bar by searching for ‘cmd’. You should be able to recognize when you have started such a window because you will see a Windows “command prompt”, which usually looks like this: C:\> The letter may be different, and there might be other things after it, so you might just as easily see something like: D:\YourName\Projects\Python> depending on how your computer has been set up and what else you have recently done with it. Once you have started such a window, you are well on the way to running Python programs. You need to realize that your Python scripts have to be processed by another program called the Python `interpreter'. The interpreter reads your script, compiles it into bytecodes, and then executes the bytecodes to run your program. So, how do you arrange for the interpreter to handle your Python? First, you need to make sure that your command window recognises the word “py” as an instruction to start the interpreter. If you have opened a command window, you should try entering the command ‘py’ and hitting return: C:\Users\YourName> py You should then see something like: Python 3.6.4 (v3.6.4:d48eceb, Dec 19 2017, 06:04:45) [MSC v.1900 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> You have started the interpreter in “interactive mode”. That means you can enter Python statements or expressions interactively and have them executed or evaluated while you wait. This is one of Python’s strongest features. Check it by entering a few expressions of your choice and seeing the results: >>> print("Hello") Hello >>> "Hello" * 3 'HelloHelloHello' Many people use the interactive mode as a convenient yet highly programmable calculator. When you want to end your interactive Python session, call the *note exit(): 12b9. function or hold the ‘Ctrl’ key down while you enter a ‘Z’, then hit the “‘Enter’” key to get back to your Windows command prompt. You may also find that you have a Start-menu entry such as Start ‣ Programs ‣ Python 3.x ‣ Python (command line) that results in you seeing the ‘>>>’ prompt in a new window. If so, the window will disappear after you call the *note exit(): 12b9. function or enter the ‘Ctrl-Z’ character; Windows is running a single “python” command in the window, and closes it when you terminate the interpreter. Now that we know the ‘py’ command is recognized, you can give your Python script to it. You’ll have to give either an absolute or a relative path to the Python script. Let’s say your Python script is located in your desktop and is named ‘hello.py’, and your command prompt is nicely opened in your home directory so you’re seeing something similar to: C:\Users\YourName> So now you’ll ask the ‘py’ command to give your script to Python by typing ‘py’ followed by your script path: C:\Users\YourName> py Desktop\hello.py hello  File: python.info, Node: How do I make Python scripts executable?, Next: Why does Python sometimes take so long to start?, Prev: How do I run a Python program under Windows?, Up: Python on Windows FAQ 11.6.2 How do I make Python scripts executable? ----------------------------------------------- On Windows, the standard Python installer already associates the .py extension with a file type (Python.File) and gives that file type an open command that runs the interpreter (‘D:\Program Files\Python\python.exe "%1" %*’). This is enough to make scripts executable from the command prompt as ‘foo.py’. If you’d rather be able to execute the script by simple typing ‘foo’ with no extension you need to add .py to the PATHEXT environment variable.  File: python.info, Node: Why does Python sometimes take so long to start?, Next: How do I make an executable from a Python script?, Prev: How do I make Python scripts executable?, Up: Python on Windows FAQ 11.6.3 Why does Python sometimes take so long to start? ------------------------------------------------------- Usually Python starts very quickly on Windows, but occasionally there are bug reports that Python suddenly begins to take a long time to start up. This is made even more puzzling because Python will work fine on other Windows systems which appear to be configured identically. The problem may be caused by a misconfiguration of virus checking software on the problem machine. Some virus scanners have been known to introduce startup overhead of two orders of magnitude when the scanner is configured to monitor all reads from the filesystem. Try checking the configuration of virus scanning software on your systems to ensure that they are indeed configured identically. McAfee, when configured to scan all file system read activity, is a particular offender.  File: python.info, Node: How do I make an executable from a Python script?, Next: Is a * pyd file the same as a DLL?, Prev: Why does Python sometimes take so long to start?, Up: Python on Windows FAQ 11.6.4 How do I make an executable from a Python script? -------------------------------------------------------- See cx_Freeze(1) for a distutils extension that allows you to create console and GUI executables from Python code. py2exe(2), the most popular extension for building Python 2.x-based executables, does not yet support Python 3 but a version that does is in development. ---------- Footnotes ---------- (1) https://cx-freeze.readthedocs.io/en/latest/ (2) http://www.py2exe.org/  File: python.info, Node: Is a * pyd file the same as a DLL?, Next: How can I embed Python into a Windows application?, Prev: How do I make an executable from a Python script?, Up: Python on Windows FAQ 11.6.5 Is a ‘*.pyd’ file the same as a DLL? ------------------------------------------- Yes, .pyd files are dll’s, but there are a few differences. If you have a DLL named ‘foo.pyd’, then it must have a function ‘PyInit_foo()’. You can then write Python “import foo”, and Python will search for foo.pyd (as well as foo.py, foo.pyc) and if it finds it, will attempt to call ‘PyInit_foo()’ to initialize it. You do not link your .exe with foo.lib, as that would cause Windows to require the DLL to be present. Note that the search path for foo.pyd is PYTHONPATH, not the same as the path that Windows uses to search for foo.dll. Also, foo.pyd need not be present to run your program, whereas if you linked your program with a dll, the dll is required. Of course, foo.pyd is required if you want to say ‘import foo’. In a DLL, linkage is declared in the source code with ‘__declspec(dllexport)’. In a .pyd, linkage is defined in a list of available functions.  File: python.info, Node: How can I embed Python into a Windows application?, Next: How do I keep editors from inserting tabs into my Python source?, Prev: Is a * pyd file the same as a DLL?, Up: Python on Windows FAQ 11.6.6 How can I embed Python into a Windows application? --------------------------------------------------------- Embedding the Python interpreter in a Windows app can be summarized as follows: 1. Do _not_ build Python into your .exe file directly. On Windows, Python must be a DLL to handle importing modules that are themselves DLL’s. (This is the first key undocumented fact.) Instead, link to ‘python`NN'.dll’; it is typically installed in ‘C:\Windows\System’. `NN' is the Python version, a number such as “33” for Python 3.3. You can link to Python in two different ways. Load-time linking means linking against ‘python`NN'.lib’, while run-time linking means linking against ‘python`NN'.dll’. (General note: ‘python`NN'.lib’ is the so-called “import lib” corresponding to ‘python`NN'.dll’. It merely defines symbols for the linker.) Run-time linking greatly simplifies link options; everything happens at run time. Your code must load ‘python`NN'.dll’ using the Windows ‘LoadLibraryEx()’ routine. The code must also use access routines and data in ‘python`NN'.dll’ (that is, Python’s C API’s) using pointers obtained by the Windows ‘GetProcAddress()’ routine. Macros can make using these pointers transparent to any C code that calls routines in Python’s C API. Borland note: convert ‘python`NN'.lib’ to OMF format using Coff2Omf.exe first. 2. If you use SWIG, it is easy to create a Python “extension module” that will make the app’s data and methods available to Python. SWIG will handle just about all the grungy details for you. The result is C code that you link `into' your .exe file (!) You do _not_ have to create a DLL file, and this also simplifies linking. 3. SWIG will create an init function (a C function) whose name depends on the name of the extension module. For example, if the name of the module is leo, the init function will be called initleo(). If you use SWIG shadow classes, as you should, the init function will be called initleoc(). This initializes a mostly hidden helper class used by the shadow class. The reason you can link the C code in step 2 into your .exe file is that calling the initialization function is equivalent to importing the module into Python! (This is the second key undocumented fact.) 4. In short, you can use the following code to initialize the Python interpreter with your extension module. #include "python.h" ... Py_Initialize(); // Initialize Python. initmyAppc(); // Initialize (import) the helper class. PyRun_SimpleString("import myApp"); // Import the shadow class. 5. There are two problems with Python’s C API which will become apparent if you use a compiler other than MSVC, the compiler used to build pythonNN.dll. Problem 1: The so-called “Very High Level” functions that take FILE * arguments will not work in a multi-compiler environment because each compiler’s notion of a struct FILE will be different. From an implementation standpoint these are very _low_ level functions. Problem 2: SWIG generates the following code when generating wrappers to void functions: Py_INCREF(Py_None); _resultobj = Py_None; return _resultobj; Alas, Py_None is a macro that expands to a reference to a complex data structure called _Py_NoneStruct inside pythonNN.dll. Again, this code will fail in a mult-compiler environment. Replace such code by: return Py_BuildValue(""); It may be possible to use SWIG’s ‘%typemap’ command to make the change automatically, though I have not been able to get this to work (I’m a complete SWIG newbie). 6. Using a Python shell script to put up a Python interpreter window from inside your Windows app is not a good idea; the resulting window will be independent of your app’s windowing system. Rather, you (or the wxPythonWindow class) should create a “native” interpreter window. It is easy to connect that window to the Python interpreter. You can redirect Python’s i/o to _any_ object that supports read and write, so all you need is a Python object (defined in your extension module) that contains read() and write() methods.  File: python.info, Node: How do I keep editors from inserting tabs into my Python source?, Next: How do I check for a keypress without blocking?, Prev: How can I embed Python into a Windows application?, Up: Python on Windows FAQ 11.6.7 How do I keep editors from inserting tabs into my Python source? ----------------------------------------------------------------------- The FAQ does not recommend using tabs, and the Python style guide, PEP 8(1), recommends 4 spaces for distributed Python code; this is also the Emacs python-mode default. Under any editor, mixing tabs and spaces is a bad idea. MSVC is no different in this respect, and is easily configured to use spaces: Take Tools ‣ Options ‣ Tabs, and for file type “Default” set “Tab size” and “Indent size” to 4, and select the “Insert spaces” radio button. Python raises *note IndentationError: e78. or *note TabError: e77. if mixed tabs and spaces are causing problems in leading whitespace. You may also run the *note tabnanny: 100. module to check a directory tree in batch mode. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0008  File: python.info, Node: How do I check for a keypress without blocking?, Prev: How do I keep editors from inserting tabs into my Python source?, Up: Python on Windows FAQ 11.6.8 How do I check for a keypress without blocking? ------------------------------------------------------ Use the *note msvcrt: b6. module. This is a standard Windows-specific extension module. It defines a function ‘kbhit()’ which checks whether a keyboard hit is present, and ‘getch()’ which gets one character without echoing it.  File: python.info, Node: Graphic User Interface FAQ, Next: “Why is Python Installed on my Computer?” FAQ, Prev: Python on Windows FAQ, Up: Python Frequently Asked Questions 11.7 Graphic User Interface FAQ =============================== * Menu: * General GUI Questions:: * What platform-independent GUI toolkits exist for Python?:: * What platform-specific GUI toolkits exist for Python?:: * Tkinter questions::  File: python.info, Node: General GUI Questions, Next: What platform-independent GUI toolkits exist for Python?, Up: Graphic User Interface FAQ 11.7.1 General GUI Questions ----------------------------  File: python.info, Node: What platform-independent GUI toolkits exist for Python?, Next: What platform-specific GUI toolkits exist for Python?, Prev: General GUI Questions, Up: Graphic User Interface FAQ 11.7.2 What platform-independent GUI toolkits exist for Python? --------------------------------------------------------------- Depending on what platform(s) you are aiming at, there are several. Some of them haven’t been ported to Python 3 yet. At least *note Tkinter: 4055. and *note Qt: 4056. are known to be Python 3-compatible. * Menu: * Tkinter:: * wxWidgets:: * Qt:: * Gtk+:: * Kivy:: * FLTK:: * OpenGL::  File: python.info, Node: Tkinter, Next: wxWidgets, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.1 Tkinter ................ Standard builds of Python include an object-oriented interface to the Tcl/Tk widget set, called *note tkinter: 2e7f. This is probably the easiest to install (since it comes included with most binary distributions(1) of Python) and use. For more info about Tk, including pointers to the source, see the Tcl/Tk home page(2). Tcl/Tk is fully portable to the Mac OS X, Windows, and Unix platforms. ---------- Footnotes ---------- (1) https://www.python.org/downloads/ (2) https://www.tcl.tk  File: python.info, Node: wxWidgets, Next: Qt, Prev: Tkinter, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.2 wxWidgets .................. wxWidgets (‘https://www.wxwidgets.org’) is a free, portable GUI class library written in C++ that provides a native look and feel on a number of platforms, with Windows, Mac OS X, GTK, X11, all listed as current stable targets. Language bindings are available for a number of languages including Python, Perl, Ruby, etc. wxPython(1) is the Python binding for wxwidgets. While it often lags slightly behind the official wxWidgets releases, it also offers a number of features via pure Python extensions that are not available in other language bindings. There is an active wxPython user and developer community. Both wxWidgets and wxPython are free, open source, software with permissive licences that allow their use in commercial products as well as in freeware or shareware. ---------- Footnotes ---------- (1) https://www.wxpython.org  File: python.info, Node: Qt, Next: Gtk+, Prev: wxWidgets, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.3 Qt ........... There are bindings available for the Qt toolkit (using either PyQt(1) or PySide(2)) and for KDE (PyKDE4(3)). PyQt is currently more mature than PySide, but you must buy a PyQt license from Riverbank Computing(4) if you want to write proprietary applications. PySide is free for all applications. Qt 4.5 upwards is licensed under the LGPL license; also, commercial licenses are available from The Qt Company(5). ---------- Footnotes ---------- (1) https://riverbankcomputing.com/software/pyqt/intro (2) https://wiki.qt.io/PySide (3) https://techbase.kde.org/Languages/Python/Using_PyKDE_4 (4) https://www.riverbankcomputing.com/commercial/license-faq (5) https://www.qt.io/licensing/  File: python.info, Node: Gtk+, Next: Kivy, Prev: Qt, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.4 Gtk+ ............. The GObject introspection bindings(1) for Python allow you to write GTK+ 3 applications. There is also a Python GTK+ 3 Tutorial(2). The older PyGtk bindings for the Gtk+ 2 toolkit(3) have been implemented by James Henstridge; see <‘http://www.pygtk.org’>. ---------- Footnotes ---------- (1) https://wiki.gnome.org/Projects/PyGObject (2) https://python-gtk-3-tutorial.readthedocs.io (3) https://www.gtk.org  File: python.info, Node: Kivy, Next: FLTK, Prev: Gtk+, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.5 Kivy ............. Kivy(1) is a cross-platform GUI library supporting both desktop operating systems (Windows, macOS, Linux) and mobile devices (Android, iOS). It is written in Python and Cython, and can use a range of windowing backends. Kivy is free and open source software distributed under the MIT license. ---------- Footnotes ---------- (1) https://kivy.org/  File: python.info, Node: FLTK, Next: OpenGL, Prev: Kivy, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.6 FLTK ............. Python bindings for the FLTK toolkit(1), a simple yet powerful and mature cross-platform windowing system, are available from the PyFLTK project(2). ---------- Footnotes ---------- (1) http://www.fltk.org (2) http://pyfltk.sourceforge.net  File: python.info, Node: OpenGL, Prev: FLTK, Up: What platform-independent GUI toolkits exist for Python? 11.7.2.7 OpenGL ............... For OpenGL bindings, see PyOpenGL(1). ---------- Footnotes ---------- (1) http://pyopengl.sourceforge.net  File: python.info, Node: What platform-specific GUI toolkits exist for Python?, Next: Tkinter questions, Prev: What platform-independent GUI toolkits exist for Python?, Up: Graphic User Interface FAQ 11.7.3 What platform-specific GUI toolkits exist for Python? ------------------------------------------------------------ By installing the PyObjc Objective-C bridge(1), Python programs can use Mac OS X’s Cocoa libraries. *note Pythonwin: 4047. by Mark Hammond includes an interface to the Microsoft Foundation Classes and a Python programming environment that’s written mostly in Python using the MFC classes. ---------- Footnotes ---------- (1) https://pypi.org/project/pyobjc/  File: python.info, Node: Tkinter questions, Prev: What platform-specific GUI toolkits exist for Python?, Up: Graphic User Interface FAQ 11.7.4 Tkinter questions ------------------------ * Menu: * How do I freeze Tkinter applications?:: * Can I have Tk events handled while waiting for I/O?:: * I can’t get key bindings to work in Tkinter; why?: I can’t get key bindings to work in Tkinter why?.  File: python.info, Node: How do I freeze Tkinter applications?, Next: Can I have Tk events handled while waiting for I/O?, Up: Tkinter questions 11.7.4.1 How do I freeze Tkinter applications? .............................................. Freeze is a tool to create stand-alone applications. When freezing Tkinter applications, the applications will not be truly stand-alone, as the application will still need the Tcl and Tk libraries. One solution is to ship the application with the Tcl and Tk libraries, and point to them at run-time using the ‘TCL_LIBRARY’ and ‘TK_LIBRARY’ environment variables. To get truly stand-alone applications, the Tcl scripts that form the library have to be integrated into the application as well. One tool supporting that is SAM (stand-alone modules), which is part of the Tix distribution (‘http://tix.sourceforge.net/’). Build Tix with SAM enabled, perform the appropriate call to ‘Tclsam_init()’, etc. inside Python’s ‘Modules/tkappinit.c’, and link with libtclsam and libtksam (you might include the Tix libraries as well).  File: python.info, Node: Can I have Tk events handled while waiting for I/O?, Next: I can’t get key bindings to work in Tkinter why?, Prev: How do I freeze Tkinter applications?, Up: Tkinter questions 11.7.4.2 Can I have Tk events handled while waiting for I/O? ............................................................ On platforms other than Windows, yes, and you don’t even need threads! But you’ll have to restructure your I/O code a bit. Tk has the equivalent of Xt’s ‘XtAddInput()’ call, which allows you to register a callback function which will be called from the Tk mainloop when I/O is possible on a file descriptor. See *note File Handlers: 2e99.  File: python.info, Node: I can’t get key bindings to work in Tkinter why?, Prev: Can I have Tk events handled while waiting for I/O?, Up: Tkinter questions 11.7.4.3 I can’t get key bindings to work in Tkinter: why? .......................................................... An often-heard complaint is that event handlers bound to events with the ‘bind()’ method don’t get handled even when the appropriate key is pressed. The most common cause is that the widget to which the binding applies doesn’t have “keyboard focus”. Check out the Tk documentation for the focus command. Usually a widget is given the keyboard focus by clicking in it (but not for labels; see the takefocus option).  File: python.info, Node: “Why is Python Installed on my Computer?” FAQ, Prev: Graphic User Interface FAQ, Up: Python Frequently Asked Questions 11.8 “Why is Python Installed on my Computer?” FAQ ================================================== * Menu: * What is Python?: What is Python?<2>. * Why is Python installed on my machine?:: * Can I delete Python?::  File: python.info, Node: What is Python?<2>, Next: Why is Python installed on my machine?, Up: “Why is Python Installed on my Computer?” FAQ 11.8.1 What is Python? ---------------------- Python is a programming language. It’s used for many different applications. It’s used in some high schools and colleges as an introductory programming language because Python is easy to learn, but it’s also used by professional software developers at places such as Google, NASA, and Lucasfilm Ltd. If you wish to learn more about Python, start with the Beginner’s Guide to Python(1). ---------- Footnotes ---------- (1) https://wiki.python.org/moin/BeginnersGuide  File: python.info, Node: Why is Python installed on my machine?, Next: Can I delete Python?, Prev: What is Python?<2>, Up: “Why is Python Installed on my Computer?” FAQ 11.8.2 Why is Python installed on my machine? --------------------------------------------- If you find Python installed on your system but don’t remember installing it, there are several possible ways it could have gotten there. * Perhaps another user on the computer wanted to learn programming and installed it; you’ll have to figure out who’s been using the machine and might have installed it. * A third-party application installed on the machine might have been written in Python and included a Python installation. There are many such applications, from GUI programs to network servers and administrative scripts. * Some Windows machines also have Python installed. At this writing we’re aware of computers from Hewlett-Packard and Compaq that include Python. Apparently some of HP/Compaq’s administrative tools are written in Python. * Many Unix-compatible operating systems, such as Mac OS X and some Linux distributions, have Python installed by default; it’s included in the base installation.  File: python.info, Node: Can I delete Python?, Prev: Why is Python installed on my machine?, Up: “Why is Python Installed on my Computer?” FAQ 11.8.3 Can I delete Python? --------------------------- That depends on where Python came from. If someone installed it deliberately, you can remove it without hurting anything. On Windows, use the Add/Remove Programs icon in the Control Panel. If Python was installed by a third-party application, you can also remove it, but that application will no longer work. You should use that application’s uninstaller rather than removing Python directly. If Python came with your operating system, removing it is not recommended. If you remove it, whatever tools were written in Python will no longer run, and some of them might be important to you. Reinstalling the whole system would then be required to fix things again.  File: python.info, Node: Glossary, Next: About these documents, Prev: Python Frequently Asked Questions, Up: Top 12 Glossary *********** ‘>>>’ The default Python prompt of the interactive shell. Often seen for code examples which can be executed interactively in the interpreter. ‘...’ Can refer to: * The default Python prompt of the interactive shell when entering the code for an indented code block, when within a pair of matching left and right delimiters (parentheses, square brackets, curly braces or triple quotes), or after specifying a decorator. * The *note Ellipsis: 12b6. built-in constant. 2to3 A tool that tries to convert Python 2.x code to Python 3.x code by handling most of the incompatibilities which can be detected by parsing the source and traversing the parse tree. 2to3 is available in the standard library as *note lib2to3: a7.; a standalone entry point is provided as ‘Tools/scripts/2to3’. See *note 2to3 - Automated Python 2 to 3 code translation: c76. abstract base class Abstract base classes complement *note duck-typing: 4069. by providing a way to define interfaces when other techniques like *note hasattr(): 447. would be clumsy or subtly wrong (for example with *note magic methods: 10de.). ABCs introduce virtual subclasses, which are classes that don’t inherit from a class but are still recognized by *note isinstance(): 44f. and *note issubclass(): 450.; see the *note abc: 4. module documentation. Python comes with many built-in ABCs for data structures (in the *note collections.abc: 1f. module), numbers (in the *note numbers: c1. module), streams (in the *note io: a1. module), import finders and loaders (in the *note importlib.abc: 9c. module). You can create your own ABCs with the *note abc: 4. module. annotation A label associated with a variable, a class attribute or a function parameter or return value, used by convention as a *note type hint: 406b. Annotations of local variables cannot be accessed at runtime, but annotations of global variables, class attributes, and functions are stored in the ‘__annotations__’ special attribute of modules, classes, and functions, respectively. See *note variable annotation: 61f, *note function annotation: ef1, PEP 484(1) and PEP 526(2), which describe this functionality. argument A value passed to a *note function: 11c9. (or *note method: 406c.) when calling the function. There are two kinds of argument: * `keyword argument': an argument preceded by an identifier (e.g. ‘name=’) in a function call or passed as a value in a dictionary preceded by ‘**’. For example, ‘3’ and ‘5’ are both keyword arguments in the following calls to *note complex(): 189.: complex(real=3, imag=5) complex(**{'real': 3, 'imag': 5}) * `positional argument': an argument that is not a keyword argument. Positional arguments can appear at the beginning of an argument list and/or be passed as elements of an *note iterable: bac. preceded by ‘*’. For example, ‘3’ and ‘5’ are both positional arguments in the following calls: complex(3, 5) complex(*(3, 5)) Arguments are assigned to the named local variables in a function body. See the *note Calls: 64c. section for the rules governing this assignment. Syntactically, any expression can be used to represent an argument; the evaluated value is assigned to the local variable. See also the *note parameter: 11d2. glossary entry, the FAQ question on *note the difference between arguments and parameters: 3fb4, and PEP 362(3). asynchronous context manager An object which controls the environment seen in an *note async with: 643. statement by defining *note __aenter__(): 113b. and *note __aexit__(): 113c. methods. Introduced by PEP 492(4). asynchronous generator A function which returns an *note asynchronous generator iterator: 335c. It looks like a coroutine function defined with *note async def: 284. except that it contains *note yield: 18f. expressions for producing a series of values usable in an *note async for: 2e3. loop. Usually refers to an asynchronous generator function, but may refer to an `asynchronous generator iterator' in some contexts. In cases where the intended meaning isn’t clear, using the full terms avoids ambiguity. An asynchronous generator function may contain *note await: 1a3. expressions as well as *note async for: 2e3, and *note async with: 643. statements. asynchronous generator iterator An object created by a *note asynchronous generator: 11a9. function. This is an *note asynchronous iterator: 645. which when called using the *note __anext__(): 1138. method returns an awaitable object which will execute the body of the asynchronous generator function until the next *note yield: 18f. expression. Each *note yield: 18f. temporarily suspends processing, remembering the location execution state (including local variables and pending try-statements). When the `asynchronous generator iterator' effectively resumes with another awaitable returned by *note __anext__(): 1138, it picks up where it left off. See PEP 492(5) and PEP 525(6). asynchronous iterable An object, that can be used in an *note async for: 2e3. statement. Must return an *note asynchronous iterator: 645. from its *note __aiter__(): 487. method. Introduced by PEP 492(7). asynchronous iterator An object that implements the *note __aiter__(): 487. and *note __anext__(): 1138. methods. ‘__anext__’ must return an *note awaitable: 519. object. *note async for: 2e3. resolves the awaitables returned by an asynchronous iterator’s *note __anext__(): 1138. method until it raises a *note StopAsyncIteration: 10cd. exception. Introduced by PEP 492(8). attribute A value associated with an object which is referenced by name using dotted expressions. For example, if an object `o' has an attribute `a' it would be referenced as `o.a'. awaitable An object that can be used in an *note await: 1a3. expression. Can be a *note coroutine: 1a6. or an object with an *note __await__(): 642. method. See also PEP 492(9). BDFL Benevolent Dictator For Life, a.k.a. Guido van Rossum(10), Python’s creator. binary file A *note file object: b42. able to read and write *note bytes-like objects: 5e8. Examples of binary files are files opened in binary mode (‘'rb'’, ‘'wb'’ or ‘'rb+'’), ‘sys.stdin.buffer’, ‘sys.stdout.buffer’, and instances of *note io.BytesIO: 79b. and *note gzip.GzipFile: 6dd. See also *note text file: f3a. for a file object able to read and write *note str: 330. objects. bytes-like object An object that supports the *note Buffer Protocol: 1291. and can export a C-*note contiguous: 1360. buffer. This includes all *note bytes: 331, *note bytearray: 332, and *note array.array: 451. objects, as well as many common *note memoryview: 25c. objects. Bytes-like objects can be used for various operations that work with binary data; these include compression, saving to a binary file, and sending over a socket. Some operations need the binary data to be mutable. The documentation often refers to these as “read-write bytes-like objects”. Example mutable buffer objects include *note bytearray: 332. and a *note memoryview: 25c. of a *note bytearray: 332. Other operations require the binary data to be stored in immutable objects (“read-only bytes-like objects”); examples of these include *note bytes: 331. and a *note memoryview: 25c. of a *note bytes: 331. object. bytecode Python source code is compiled into bytecode, the internal representation of a Python program in the CPython interpreter. The bytecode is also cached in ‘.pyc’ files so that executing the same file is faster the second time (recompilation from source to bytecode can be avoided). This “intermediate language” is said to run on a *note virtual machine: 247d. that executes the machine code corresponding to each bytecode. Do note that bytecodes are not expected to work between different Python virtual machines, nor to be stable between Python releases. A list of bytecode instructions can be found in the documentation for *note the dis module: 35dc. callback A subroutine function which is passed as an argument to be executed at some point in the future. class A template for creating user-defined objects. Class definitions normally contain method definitions which operate on instances of the class. class variable A variable defined in a class and intended to be modified only at class level (i.e., not in an instance of the class). coercion The implicit conversion of an instance of one type to another during an operation which involves two arguments of the same type. For example, ‘int(3.15)’ converts the floating point number to the integer ‘3’, but in ‘3+4.5’, each argument is of a different type (one int, one float), and both must be converted to the same type before they can be added or it will raise a *note TypeError: 192. Without coercion, all arguments of even compatible types would have to be normalized to the same value by the programmer, e.g., ‘float(3)+4.5’ rather than just ‘3+4.5’. complex number An extension of the familiar real number system in which all numbers are expressed as a sum of a real part and an imaginary part. Imaginary numbers are real multiples of the imaginary unit (the square root of ‘-1’), often written ‘i’ in mathematics or ‘j’ in engineering. Python has built-in support for complex numbers, which are written with this latter notation; the imaginary part is written with a ‘j’ suffix, e.g., ‘3+1j’. To get access to complex equivalents of the *note math: b1. module, use *note cmath: 19. Use of complex numbers is a fairly advanced mathematical feature. If you’re not aware of a need for them, it’s almost certain you can safely ignore them. context manager An object which controls the environment seen in a *note with: 6e9. statement by defining *note __enter__(): c95. and *note __exit__(): c96. methods. See PEP 343(11). context variable A variable which can have different values depending on its context. This is similar to Thread-Local Storage in which each execution thread may have a different value for a variable. However, with context variables, there may be several contexts in one execution thread and the main usage for context variables is to keep track of variables in concurrent asynchronous tasks. See *note contextvars: 25. contiguous A buffer is considered contiguous exactly if it is either `C-contiguous' or `Fortran contiguous'. Zero-dimensional buffers are C and Fortran contiguous. In one-dimensional arrays, the items must be laid out in memory next to each other, in order of increasing indexes starting from zero. In multidimensional C-contiguous arrays, the last index varies the fastest when visiting items in order of memory address. However, in Fortran contiguous arrays, the first index varies the fastest. coroutine Coroutines are a more generalized form of subroutines. Subroutines are entered at one point and exited at another point. Coroutines can be entered, exited, and resumed at many different points. They can be implemented with the *note async def: 284. statement. See also PEP 492(12). coroutine function A function which returns a *note coroutine: 1a6. object. A coroutine function may be defined with the *note async def: 284. statement, and may contain *note await: 1a3, *note async for: 2e3, and *note async with: 643. keywords. These were introduced by PEP 492(13). CPython The canonical implementation of the Python programming language, as distributed on python.org(14). The term “CPython” is used when necessary to distinguish this implementation from others such as Jython or IronPython. decorator A function returning another function, usually applied as a function transformation using the ‘@wrapper’ syntax. Common examples for decorators are *note classmethod(): 1d8. and *note staticmethod(): 1d9. The decorator syntax is merely syntactic sugar, the following two function definitions are semantically equivalent: def f(...): ... f = staticmethod(f) @staticmethod def f(...): ... The same concept exists for classes, but is less commonly used there. See the documentation for *note function definitions: ef0. and *note class definitions: c6a. for more about decorators. descriptor Any object which defines the methods *note __get__(): 10dd, *note __set__(): 10e1, or *note __delete__(): 10e2. When a class attribute is a descriptor, its special binding behavior is triggered upon attribute lookup. Normally, using `a.b' to get, set or delete an attribute looks up the object named `b' in the class dictionary for `a', but if `b' is a descriptor, the respective descriptor method gets called. Understanding descriptors is a key to a deep understanding of Python because they are the basis for many features including functions, methods, properties, class methods, static methods, and reference to super classes. For more information about descriptors’ methods, see *note Implementing Descriptors: 4e9. dictionary An associative array, where arbitrary keys are mapped to values. The keys can be any object with *note __hash__(): 340. and *note __eq__(): 33f. methods. Called a hash in Perl. dictionary comprehension A compact way to process all or part of the elements in an iterable and return a dictionary with the results. ‘results = {n: n ** 2 for n in range(10)}’ generates a dictionary containing key ‘n’ mapped to value ‘n ** 2’. See *note Displays for lists, sets and dictionaries: 1191. dictionary view The objects returned from *note dict.keys(): c2a, *note dict.values(): c2c, and *note dict.items(): c2b. are called dictionary views. They provide a dynamic view on the dictionary’s entries, which means that when the dictionary changes, the view reflects these changes. To force the dictionary view to become a full list use ‘list(dictview)’. See *note Dictionary view objects: 1381. docstring A string literal which appears as the first expression in a class, function or module. While ignored when the suite is executed, it is recognized by the compiler and put into the ‘__doc__’ attribute of the enclosing class, function or module. Since it is available via introspection, it is the canonical place for documentation of the object. duck-typing A programming style which does not look at an object’s type to determine if it has the right interface; instead, the method or attribute is simply called or used (“If it looks like a duck and quacks like a duck, it must be a duck.”) By emphasizing interfaces rather than specific types, well-designed code improves its flexibility by allowing polymorphic substitution. Duck-typing avoids tests using *note type(): 608. or *note isinstance(): 44f. (Note, however, that duck-typing can be complemented with *note abstract base classes: b33.) Instead, it typically employs *note hasattr(): 447. tests or *note EAFP: 1c20. programming. EAFP Easier to ask for forgiveness than permission. This common Python coding style assumes the existence of valid keys or attributes and catches exceptions if the assumption proves false. This clean and fast style is characterized by the presence of many *note try: d72. and *note except: b3e. statements. The technique contrasts with the *note LBYL: 4075. style common to many other languages such as C. expression A piece of syntax which can be evaluated to some value. In other words, an expression is an accumulation of expression elements like literals, names, attribute access, operators or function calls which all return a value. In contrast to many other languages, not all language constructs are expressions. There are also *note statement: 1847.s which cannot be used as expressions, such as *note while: ec1. Assignments are also statements, not expressions. extension module A module written in C or C++, using Python’s C API to interact with the core and with user code. f-string String literals prefixed with ‘'f'’ or ‘'F'’ are commonly called “f-strings” which is short for *note formatted string literals: 15c. See also PEP 498(15). file object An object exposing a file-oriented API (with methods such as ‘read()’ or ‘write()’) to an underlying resource. Depending on the way it was created, a file object can mediate access to a real on-disk file or to another type of storage or communication device (for example standard input/output, in-memory buffers, sockets, pipes, etc.). File objects are also called `file-like objects' or `streams'. There are actually three categories of file objects: raw *note binary files: 1966, buffered *note binary files: 1966. and *note text files: f3a. Their interfaces are defined in the *note io: a1. module. The canonical way to create a file object is by using the *note open(): 4f0. function. file-like object A synonym for *note file object: b42. finder An object that tries to find the *note loader: 1160. for a module that is being imported. Since Python 3.3, there are two types of finder: *note meta path finders: 9b1. for use with *note sys.meta_path: 5e6, and *note path entry finders: 9b2. for use with *note sys.path_hooks: 95c. See PEP 302(16), PEP 420(17) and PEP 451(18) for much more detail. floor division Mathematical division that rounds down to nearest integer. The floor division operator is ‘//’. For example, the expression ‘11 // 4’ evaluates to ‘2’ in contrast to the ‘2.75’ returned by float true division. Note that ‘(-11) // 4’ is ‘-3’ because that is ‘-2.75’ rounded `downward'. See PEP 238(19). function A series of statements which returns some value to a caller. It can also be passed zero or more *note arguments: 11ca. which may be used in the execution of the body. See also *note parameter: 11d2, *note method: 406c, and the *note Function definitions: ef0. section. function annotation An *note annotation: 406a. of a function parameter or return value. Function annotations are usually used for *note type hints: 406b.: for example, this function is expected to take two *note int: 184. arguments and is also expected to have an *note int: 184. return value: def sum_two_numbers(a: int, b: int) -> int: return a + b Function annotation syntax is explained in section *note Function definitions: ef0. See *note variable annotation: 61f. and PEP 484(20), which describe this functionality. __future__ A pseudo-module which programmers can use to enable new language features which are not compatible with the current interpreter. By importing the *note __future__: 0. module and evaluating its variables, you can see when a new feature was first added to the language and when it becomes the default: >>> import __future__ >>> __future__.division _Feature((2, 2, 0, 'alpha', 2), (3, 0, 0, 'alpha', 0), 8192) garbage collection The process of freeing memory when it is not used anymore. Python performs garbage collection via reference counting and a cyclic garbage collector that is able to detect and break reference cycles. The garbage collector can be controlled using the *note gc: 86. module. generator A function which returns a *note generator iterator: 457. It looks like a normal function except that it contains *note yield: 18f. expressions for producing a series of values usable in a for-loop or that can be retrieved one at a time with the *note next(): 682. function. Usually refers to a generator function, but may refer to a `generator iterator' in some contexts. In cases where the intended meaning isn’t clear, using the full terms avoids ambiguity. generator iterator An object created by a *note generator: 9a2. function. Each *note yield: 18f. temporarily suspends processing, remembering the location execution state (including local variables and pending try-statements). When the `generator iterator' resumes, it picks up where it left off (in contrast to functions which start fresh on every invocation). generator expression An expression that returns an iterator. It looks like a normal expression followed by a ‘for’ clause defining a loop variable, range, and an optional ‘if’ clause. The combined expression generates values for an enclosing function: >>> sum(i*i for i in range(10)) # sum of squares 0, 1, 4, ... 81 285 generic function A function composed of multiple functions implementing the same operation for different types. Which implementation should be used during a call is determined by the dispatch algorithm. See also the *note single dispatch: 1cb. glossary entry, the *note functools.singledispatch(): 38a. decorator, and PEP 443(21). GIL See *note global interpreter lock: 506. global interpreter lock The mechanism used by the *note CPython: 10d7. interpreter to assure that only one thread executes Python *note bytecode: 614. at a time. This simplifies the CPython implementation by making the object model (including critical built-in types such as *note dict: 1b8.) implicitly safe against concurrent access. Locking the entire interpreter makes it easier for the interpreter to be multi-threaded, at the expense of much of the parallelism afforded by multi-processor machines. However, some extension modules, either standard or third-party, are designed so as to release the GIL when doing computationally-intensive tasks such as compression or hashing. Also, the GIL is always released when doing I/O. Past efforts to create a “free-threaded” interpreter (one which locks shared data at a much finer granularity) have not been successful because performance suffered in the common single-processor case. It is believed that overcoming this performance issue would make the implementation much more complicated and therefore costlier to maintain. hash-based pyc A bytecode cache file that uses the hash rather than the last-modified time of the corresponding source file to determine its validity. See *note Cached bytecode invalidation: 329. hashable An object is `hashable' if it has a hash value which never changes during its lifetime (it needs a *note __hash__(): 340. method), and can be compared to other objects (it needs an *note __eq__(): 33f. method). Hashable objects which compare equal must have the same hash value. Hashability makes an object usable as a dictionary key and a set member, because these data structures use the hash value internally. Most of Python’s immutable built-in objects are hashable; mutable containers (such as lists or dictionaries) are not; immutable containers (such as tuples and frozensets) are only hashable if their elements are hashable. Objects which are instances of user-defined classes are hashable by default. They all compare unequal (except with themselves), and their hash value is derived from their *note id(): d86. IDLE An Integrated Development Environment for Python. IDLE is a basic editor and interpreter environment which ships with the standard distribution of Python. immutable An object with a fixed value. Immutable objects include numbers, strings and tuples. Such an object cannot be altered. A new object has to be created if a different value has to be stored. They play an important role in places where a constant hash value is needed, for example as a key in a dictionary. import path A list of locations (or *note path entries: 1175.) that are searched by the *note path based finder: 1165. for modules to import. During import, this list of locations usually comes from *note sys.path: 488, but for subpackages it may also come from the parent package’s ‘__path__’ attribute. importing The process by which Python code in one module is made available to Python code in another module. importer An object that both finds and loads a module; both a *note finder: 115f. and *note loader: 1160. object. interactive Python has an interactive interpreter which means you can enter statements and expressions at the interpreter prompt, immediately execute them and see their results. Just launch ‘python’ with no arguments (possibly by selecting it from your computer’s main menu). It is a very powerful way to test out new ideas or inspect modules and packages (remember ‘help(x)’). interpreted Python is an interpreted language, as opposed to a compiled one, though the distinction can be blurry because of the presence of the bytecode compiler. This means that source files can be run directly without explicitly creating an executable which is then run. Interpreted languages typically have a shorter development/debug cycle than compiled ones, though their programs generally also run more slowly. See also *note interactive: 407a. interpreter shutdown When asked to shut down, the Python interpreter enters a special phase where it gradually releases all allocated resources, such as modules and various critical internal structures. It also makes several calls to the *note garbage collector: f9f. This can trigger the execution of code in user-defined destructors or weakref callbacks. Code executed during the shutdown phase can encounter various exceptions as the resources it relies on may not function anymore (common examples are library modules or the warnings machinery). The main reason for interpreter shutdown is that the ‘__main__’ module or the script being run has finished executing. iterable An object capable of returning its members one at a time. Examples of iterables include all sequence types (such as *note list: 262, *note str: 330, and *note tuple: 47e.) and some non-sequence types like *note dict: 1b8, *note file objects: b42, and objects of any classes you define with an *note __iter__(): 50f. method or with a *note __getitem__(): 27c. method that implements *note Sequence: ebc. semantics. Iterables can be used in a *note for: c30. loop and in many other places where a sequence is needed (*note zip(): c32, *note map(): c2d, …). When an iterable object is passed as an argument to the built-in function *note iter(): d27, it returns an iterator for the object. This iterator is good for one pass over the set of values. When using iterables, it is usually not necessary to call *note iter(): d27. or deal with iterator objects yourself. The ‘for’ statement does that automatically for you, creating a temporary unnamed variable to hold the iterator for the duration of the loop. See also *note iterator: 112e, *note sequence: ebc, and *note generator: 9a2. iterator An object representing a stream of data. Repeated calls to the iterator’s *note __next__(): c64. method (or passing it to the built-in function *note next(): 682.) return successive items in the stream. When no more data are available a *note StopIteration: 486. exception is raised instead. At this point, the iterator object is exhausted and any further calls to its ‘__next__()’ method just raise *note StopIteration: 486. again. Iterators are required to have an *note __iter__(): 50f. method that returns the iterator object itself so every iterator is also iterable and may be used in most places where other iterables are accepted. One notable exception is code which attempts multiple iteration passes. A container object (such as a *note list: 262.) produces a fresh new iterator each time you pass it to the *note iter(): d27. function or use it in a *note for: c30. loop. Attempting this with an iterator will just return the same exhausted iterator object used in the previous iteration pass, making it appear like an empty container. More information can be found in *note Iterator Types: 10fe. key function A key function or collation function is a callable that returns a value used for sorting or ordering. For example, *note locale.strxfrm(): 2d93. is used to produce a sort key that is aware of locale specific sort conventions. A number of tools in Python accept key functions to control how elements are ordered or grouped. They include *note min(): 809, *note max(): 80a, *note sorted(): 444, *note list.sort(): 445, *note heapq.merge(): 6df, *note heapq.nsmallest(): 1613, *note heapq.nlargest(): 1612, and *note itertools.groupby(): 17f3. There are several ways to create a key function. For example. the *note str.lower(): 12ee. method can serve as a key function for case insensitive sorts. Alternatively, a key function can be built from a *note lambda: c2f. expression such as ‘lambda r: (r[0], r[2])’. Also, the *note operator: c2. module provides three key function constructors: *note attrgetter(): 71b, *note itemgetter(): 261, and *note methodcaller(): 71c. See the *note Sorting HOW TO: 12ab. for examples of how to create and use key functions. keyword argument See *note argument: 11ca. lambda An anonymous inline function consisting of a single *note expression: 3350. which is evaluated when the function is called. The syntax to create a lambda function is ‘lambda [parameters]: expression’ LBYL Look before you leap. This coding style explicitly tests for pre-conditions before making calls or lookups. This style contrasts with the *note EAFP: 1c20. approach and is characterized by the presence of many *note if: de7. statements. In a multi-threaded environment, the LBYL approach can risk introducing a race condition between “the looking” and “the leaping”. For example, the code, ‘if key in mapping: return mapping[key]’ can fail if another thread removes `key' from `mapping' after the test, but before the lookup. This issue can be solved with locks or by using the EAFP approach. list A built-in Python *note sequence: ebc. Despite its name it is more akin to an array in other languages than to a linked list since access to elements is O(1). list comprehension A compact way to process all or part of the elements in a sequence and return a list with the results. ‘result = ['{:#04x}'.format(x) for x in range(256) if x % 2 == 0]’ generates a list of strings containing even hex numbers (0x..) in the range from 0 to 255. The *note if: de7. clause is optional. If omitted, all elements in ‘range(256)’ are processed. loader An object that loads a module. It must define a method named ‘load_module()’. A loader is typically returned by a *note finder: 115f. See PEP 302(22) for details and *note importlib.abc.Loader: 7c2. for an *note abstract base class: b33. magic method An informal synonym for *note special method: 338b. mapping A container object that supports arbitrary key lookups and implements the methods specified in the *note Mapping: 15f3. or *note MutableMapping: 9ef. *note abstract base classes: 15d6. Examples include *note dict: 1b8, *note collections.defaultdict: b3a, *note collections.OrderedDict: 1b9. and *note collections.Counter: 9da. meta path finder A *note finder: 115f. returned by a search of *note sys.meta_path: 5e6. Meta path finders are related to, but different from *note path entry finders: 9b2. See *note importlib.abc.MetaPathFinder: 9b3. for the methods that meta path finders implement. metaclass The class of a class. Class definitions create a class name, a class dictionary, and a list of base classes. The metaclass is responsible for taking those three arguments and creating the class. Most object oriented programming languages provide a default implementation. What makes Python special is that it is possible to create custom metaclasses. Most users never need this tool, but when the need arises, metaclasses can provide powerful, elegant solutions. They have been used for logging attribute access, adding thread-safety, tracking object creation, implementing singletons, and many other tasks. More information can be found in *note Metaclasses: 10ea. method A function which is defined inside a class body. If called as an attribute of an instance of that class, the method will get the instance object as its first *note argument: 11ca. (which is usually called ‘self’). See *note function: 11c9. and *note nested scope: 1295. method resolution order Method Resolution Order is the order in which base classes are searched for a member during lookup. See The Python 2.3 Method Resolution Order(23) for details of the algorithm used by the Python interpreter since the 2.3 release. module An object that serves as an organizational unit of Python code. Modules have a namespace containing arbitrary Python objects. Modules are loaded into Python by the process of *note importing: 1151. See also *note package: 1155. module spec A namespace containing the import-related information used to load a module. An instance of *note importlib.machinery.ModuleSpec: 116b. MRO See *note method resolution order: 12ae. mutable Mutable objects can change their value but keep their *note id(): d86. See also *note immutable: eb6. named tuple The term “named tuple” applies to any type or class that inherits from tuple and whose indexable elements are also accessible using named attributes. The type or class may have other features as well. Several built-in types are named tuples, including the values returned by *note time.localtime(): 155c. and *note os.stat(): 1f1. Another example is *note sys.float_info: 12c6.: >>> sys.float_info[1] # indexed access 1024 >>> sys.float_info.max_exp # named field access 1024 >>> isinstance(sys.float_info, tuple) # kind of tuple True Some named tuples are built-in types (such as the above examples). Alternatively, a named tuple can be created from a regular class definition that inherits from *note tuple: 47e. and that defines named fields. Such a class can be written by hand or it can be created with the factory function *note collections.namedtuple(): 1b7. The latter technique also adds some extra methods that may not be found in hand-written or built-in named tuples. namespace The place where a variable is stored. Namespaces are implemented as dictionaries. There are the local, global and built-in namespaces as well as nested namespaces in objects (in methods). Namespaces support modularity by preventing naming conflicts. For instance, the functions *note builtins.open: 4f0. and *note os.open(): 665. are distinguished by their namespaces. Namespaces also aid readability and maintainability by making it clear which module implements a function. For instance, writing *note random.seed(): c08. or *note itertools.islice(): 3a2. makes it clear that those functions are implemented by the *note random: dc. and *note itertools: a3. modules, respectively. namespace package A PEP 420(24) *note package: 1155. which serves only as a container for subpackages. Namespace packages may have no physical representation, and specifically are not like a *note regular package: 1157. because they have no ‘__init__.py’ file. See also *note module: 1150. nested scope The ability to refer to a variable in an enclosing definition. For instance, a function defined inside another function can refer to variables in the outer function. Note that nested scopes by default work only for reference and not for assignment. Local variables both read and write in the innermost scope. Likewise, global variables read and write to the global namespace. The *note nonlocal: c3f. allows writing to outer scopes. new-style class Old name for the flavor of classes now used for all class objects. In earlier Python versions, only new-style classes could use Python’s newer, versatile features like *note __slots__: e2d, descriptors, properties, *note __getattribute__(): 449, class methods, and static methods. object Any data with state (attributes or value) and defined behavior (methods). Also the ultimate base class of any *note new-style class: 196e. package A Python *note module: 1150. which can contain submodules or recursively, subpackages. Technically, a package is a Python module with an ‘__path__’ attribute. See also *note regular package: 1157. and *note namespace package: 1158. parameter A named entity in a *note function: 11c9. (or method) definition that specifies an *note argument: 11ca. (or in some cases, arguments) that the function can accept. There are five kinds of parameter: * `positional-or-keyword': specifies an argument that can be passed either *note positionally: 11ca. or as a *note keyword argument: 11ca. This is the default kind of parameter, for example `foo' and `bar' in the following: def func(foo, bar=None): ... * `positional-only': specifies an argument that can be supplied only by position. Positional-only parameters can be defined by including a ‘/’ character in the parameter list of the function definition after them, for example `posonly1' and `posonly2' in the following: def func(posonly1, posonly2, /, positional_or_keyword): ... * `keyword-only': specifies an argument that can be supplied only by keyword. Keyword-only parameters can be defined by including a single var-positional parameter or bare ‘*’ in the parameter list of the function definition before them, for example `kw_only1' and `kw_only2' in the following: def func(arg, *, kw_only1, kw_only2): ... * `var-positional': specifies that an arbitrary sequence of positional arguments can be provided (in addition to any positional arguments already accepted by other parameters). Such a parameter can be defined by prepending the parameter name with ‘*’, for example `args' in the following: def func(*args, **kwargs): ... * `var-keyword': specifies that arbitrarily many keyword arguments can be provided (in addition to any keyword arguments already accepted by other parameters). Such a parameter can be defined by prepending the parameter name with ‘**’, for example `kwargs' in the example above. Parameters can specify both optional and required arguments, as well as default values for some optional arguments. See also the *note argument: 11ca. glossary entry, the FAQ question on *note the difference between arguments and parameters: 3fb4, the *note inspect.Parameter: 6f4. class, the *note Function definitions: ef0. section, and PEP 362(25). path entry A single location on the *note import path: 1162. which the *note path based finder: 1165. consults to find modules for importing. path entry finder A *note finder: 115f. returned by a callable on *note sys.path_hooks: 95c. (i.e. a *note path entry hook: 1177.) which knows how to locate modules given a *note path entry: 1175. See *note importlib.abc.PathEntryFinder: 9b4. for the methods that path entry finders implement. path entry hook A callable on the ‘sys.path_hook’ list which returns a *note path entry finder: 9b2. if it knows how to find modules on a specific *note path entry: 1175. path based finder One of the default *note meta path finders: 9b1. which searches an *note import path: 1162. for modules. path-like object An object representing a file system path. A path-like object is either a *note str: 330. or *note bytes: 331. object representing a path, or an object implementing the *note os.PathLike: 4eb. protocol. An object that supports the *note os.PathLike: 4eb. protocol can be converted to a *note str: 330. or *note bytes: 331. file system path by calling the *note os.fspath(): 4ed. function; *note os.fsdecode(): 4ee. and *note os.fsencode(): 4ef. can be used to guarantee a *note str: 330. or *note bytes: 331. result instead, respectively. Introduced by PEP 519(26). PEP Python Enhancement Proposal. A PEP is a design document providing information to the Python community, or describing a new feature for Python or its processes or environment. PEPs should provide a concise technical specification and a rationale for proposed features. PEPs are intended to be the primary mechanisms for proposing major new features, for collecting community input on an issue, and for documenting the design decisions that have gone into Python. The PEP author is responsible for building consensus within the community and documenting dissenting opinions. See PEP 1(27). portion A set of files in a single directory (possibly stored in a zip file) that contribute to a namespace package, as defined in PEP 420(28). positional argument See *note argument: 11ca. provisional API A provisional API is one which has been deliberately excluded from the standard library’s backwards compatibility guarantees. While major changes to such interfaces are not expected, as long as they are marked provisional, backwards incompatible changes (up to and including removal of the interface) may occur if deemed necessary by core developers. Such changes will not be made gratuitously – they will occur only if serious fundamental flaws are uncovered that were missed prior to the inclusion of the API. Even for provisional APIs, backwards incompatible changes are seen as a “solution of last resort” - every attempt will still be made to find a backwards compatible resolution to any identified problems. This process allows the standard library to continue to evolve over time, without locking in problematic design errors for extended periods of time. See PEP 411(29) for more details. provisional package See *note provisional API: 348. Python 3000 Nickname for the Python 3.x release line (coined long ago when the release of version 3 was something in the distant future.) This is also abbreviated “Py3k”. Pythonic An idea or piece of code which closely follows the most common idioms of the Python language, rather than implementing code using concepts common to other languages. For example, a common idiom in Python is to loop over all elements of an iterable using a *note for: c30. statement. Many other languages don’t have this type of construct, so people unfamiliar with Python sometimes use a numerical counter instead: for i in range(len(food)): print(food[i]) As opposed to the cleaner, Pythonic method: for piece in food: print(piece) qualified name A dotted name showing the “path” from a module’s global scope to a class, function or method defined in that module, as defined in PEP 3155(30). For top-level functions and classes, the qualified name is the same as the object’s name: >>> class C: ... class D: ... def meth(self): ... pass ... >>> C.__qualname__ 'C' >>> C.D.__qualname__ 'C.D' >>> C.D.meth.__qualname__ 'C.D.meth' When used to refer to modules, the `fully qualified name' means the entire dotted path to the module, including any parent packages, e.g. ‘email.mime.text’: >>> import email.mime.text >>> email.mime.text.__name__ 'email.mime.text' reference count The number of references to an object. When the reference count of an object drops to zero, it is deallocated. Reference counting is generally not visible to Python code, but it is a key element of the *note CPython: 10d7. implementation. The *note sys: fd. module defines a *note getrefcount(): 335a. function that programmers can call to return the reference count for a particular object. regular package A traditional *note package: 1155, such as a directory containing an ‘__init__.py’ file. See also *note namespace package: 1158. __slots__ A declaration inside a class that saves memory by pre-declaring space for instance attributes and eliminating instance dictionaries. Though popular, the technique is somewhat tricky to get right and is best reserved for rare cases where there are large numbers of instances in a memory-critical application. sequence An *note iterable: bac. which supports efficient element access using integer indices via the *note __getitem__(): 27c. special method and defines a *note __len__(): dcb. method that returns the length of the sequence. Some built-in sequence types are *note list: 262, *note str: 330, *note tuple: 47e, and *note bytes: 331. Note that *note dict: 1b8. also supports *note __getitem__(): 27c. and *note __len__(): dcb, but is considered a mapping rather than a sequence because the lookups use arbitrary *note immutable: eb6. keys rather than integers. The *note collections.abc.Sequence: 12db. abstract base class defines a much richer interface that goes beyond just *note __getitem__(): 27c. and *note __len__(): dcb, adding ‘count()’, ‘index()’, *note __contains__(): d28, and *note __reversed__(): 52f. Types that implement this expanded interface can be registered explicitly using *note register(): 9d1. set comprehension A compact way to process all or part of the elements in an iterable and return a set with the results. ‘results = {c for c in 'abracadabra' if c not in 'abc'}’ generates the set of strings ‘{'r', 'd'}’. See *note Displays for lists, sets and dictionaries: 1191. single dispatch A form of *note generic function: 1ca. dispatch where the implementation is chosen based on the type of a single argument. slice An object usually containing a portion of a *note sequence: ebc. A slice is created using the subscript notation, ‘[]’ with colons between numbers when several are given, such as in ‘variable_name[1:3:5]’. The bracket (subscript) notation uses *note slice: e04. objects internally. special method A method that is called implicitly by Python to execute a certain operation on a type, such as addition. Such methods have names starting and ending with double underscores. Special methods are documented in *note Special method names: 50e. statement A statement is part of a suite (a “block” of code). A statement is either an *note expression: 3350. or one of several constructs with a keyword, such as *note if: de7, *note while: ec1. or *note for: c30. text encoding A codec which encodes Unicode strings to bytes. text file A *note file object: b42. able to read and write *note str: 330. objects. Often, a text file actually accesses a byte-oriented datastream and handles the *note text encoding: 12a5. automatically. Examples of text files are files opened in text mode (‘'r'’ or ‘'w'’), *note sys.stdin: 30d, *note sys.stdout: 30e, and instances of *note io.StringIO: 82d. See also *note binary file: 1966. for a file object able to read and write *note bytes-like objects: 5e8. triple-quoted string A string which is bound by three instances of either a quotation mark (”) or an apostrophe (‘). While they don’t provide any functionality not available with single-quoted strings, they are useful for a number of reasons. They allow you to include unescaped single and double quotes within a string and they can span multiple lines without the use of the continuation character, making them especially useful when writing docstrings. type The type of a Python object determines what kind of object it is; every object has a type. An object’s type is accessible as its *note __class__: e0a. attribute or can be retrieved with ‘type(obj)’. type alias A synonym for a type, created by assigning the type to an identifier. Type aliases are useful for simplifying *note type hints: 406b. For example: from typing import List, Tuple def remove_gray_shades( colors: List[Tuple[int, int, int]]) -> List[Tuple[int, int, int]]: pass could be made more readable like this: from typing import List, Tuple Color = Tuple[int, int, int] def remove_gray_shades(colors: List[Color]) -> List[Color]: pass See *note typing: 119. and PEP 484(31), which describe this functionality. type hint An *note annotation: 406a. that specifies the expected type for a variable, a class attribute, or a function parameter or return value. Type hints are optional and are not enforced by Python but they are useful to static type analysis tools, and aid IDEs with code completion and refactoring. Type hints of global variables, class attributes, and functions, but not local variables, can be accessed using *note typing.get_type_hints(): 30a. See *note typing: 119. and PEP 484(32), which describe this functionality. universal newlines A manner of interpreting text streams in which all of the following are recognized as ending a line: the Unix end-of-line convention ‘'\n'’, the Windows convention ‘'\r\n'’, and the old Macintosh convention ‘'\r'’. See PEP 278(33) and PEP 3116(34), as well as *note bytes.splitlines(): 134e. for an additional use. variable annotation An *note annotation: 406a. of a variable or a class attribute. When annotating a variable or a class attribute, assignment is optional: class C: field: 'annotation' Variable annotations are usually used for *note type hints: 406b.: for example this variable is expected to take *note int: 184. values: count: int = 0 Variable annotation syntax is explained in section *note Annotated assignment statements: 121e. See *note function annotation: ef1, PEP 484(35) and PEP 526(36), which describe this functionality. virtual environment A cooperatively isolated runtime environment that allows Python users and applications to install and upgrade Python distribution packages without interfering with the behaviour of other Python applications running on the same system. See also *note venv: 125. virtual machine A computer defined entirely in software. Python’s virtual machine executes the *note bytecode: 614. emitted by the bytecode compiler. Zen of Python Listing of Python design principles and philosophies that are helpful in understanding and using the language. The listing can be found by typing “‘import this’” at the interactive prompt. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0484 (2) https://www.python.org/dev/peps/pep-0526 (3) https://www.python.org/dev/peps/pep-0362 (4) https://www.python.org/dev/peps/pep-0492 (5) https://www.python.org/dev/peps/pep-0492 (6) https://www.python.org/dev/peps/pep-0525 (7) https://www.python.org/dev/peps/pep-0492 (8) https://www.python.org/dev/peps/pep-0492 (9) https://www.python.org/dev/peps/pep-0492 (10) https://gvanrossum.github.io/ (11) https://www.python.org/dev/peps/pep-0343 (12) https://www.python.org/dev/peps/pep-0492 (13) https://www.python.org/dev/peps/pep-0492 (14) https://www.python.org (15) https://www.python.org/dev/peps/pep-0498 (16) https://www.python.org/dev/peps/pep-0302 (17) https://www.python.org/dev/peps/pep-0420 (18) https://www.python.org/dev/peps/pep-0451 (19) https://www.python.org/dev/peps/pep-0238 (20) https://www.python.org/dev/peps/pep-0484 (21) https://www.python.org/dev/peps/pep-0443 (22) https://www.python.org/dev/peps/pep-0302 (23) https://www.python.org/download/releases/2.3/mro/ (24) https://www.python.org/dev/peps/pep-0420 (25) https://www.python.org/dev/peps/pep-0362 (26) https://www.python.org/dev/peps/pep-0519 (27) https://www.python.org/dev/peps/pep-0001 (28) https://www.python.org/dev/peps/pep-0420 (29) https://www.python.org/dev/peps/pep-0411 (30) https://www.python.org/dev/peps/pep-3155 (31) https://www.python.org/dev/peps/pep-0484 (32) https://www.python.org/dev/peps/pep-0484 (33) https://www.python.org/dev/peps/pep-0278 (34) https://www.python.org/dev/peps/pep-3116 (35) https://www.python.org/dev/peps/pep-0484 (36) https://www.python.org/dev/peps/pep-0526  File: python.info, Node: About these documents, Next: Dealing with Bugs, Prev: Glossary, Up: Top 13 About these documents ************************ These documents are generated from reStructuredText(1) sources by Sphinx(2), a document processor specifically written for the Python documentation. Development of the documentation and its toolchain is an entirely volunteer effort, just like Python itself. If you want to contribute, please take a look at the *note Dealing with Bugs: 38d7. page for information on how to do so. New volunteers are always welcome! Many thanks go to: * Fred L. Drake, Jr., the creator of the original Python documentation toolset and writer of much of the content; * the Docutils(3) project for creating reStructuredText and the Docutils suite; * Fredrik Lundh for his Alternative Python Reference(4) project from which Sphinx got many good ideas. * Menu: * Contributors to the Python Documentation:: ---------- Footnotes ---------- (1) http://docutils.sourceforge.net/rst.html (2) http://sphinx-doc.org/ (3) http://docutils.sourceforge.net/ (4) http://effbot.org/zone/pyref.htm  File: python.info, Node: Contributors to the Python Documentation, Up: About these documents 13.1 Contributors to the Python Documentation ============================================= Many people have contributed to the Python language, the Python standard library, and the Python documentation. See Misc/ACKS(1) in the Python source distribution for a partial list of contributors. It is only with the input and contributions of the Python community that Python has such wonderful documentation – Thank You! ---------- Footnotes ---------- (1) https://github.com/python/cpython/tree/3.8/Misc/ACKS  File: python.info, Node: Dealing with Bugs, Next: Copyright, Prev: About these documents, Up: Top 14 Dealing with Bugs ******************** Python is a mature programming language which has established a reputation for stability. In order to maintain this reputation, the developers would like to know of any deficiencies you find in Python. It can be sometimes faster to fix bugs yourself and contribute patches to Python as it streamlines the process and involves less people. Learn how to *note contribute: 408e. * Menu: * Documentation bugs:: * Using the Python issue tracker:: * Getting started contributing to Python yourself::  File: python.info, Node: Documentation bugs, Next: Using the Python issue tracker, Up: Dealing with Bugs 14.1 Documentation bugs ======================= If you find a bug in this documentation or would like to propose an improvement, please submit a bug report on the *note tracker: 4090. If you have a suggestion on how to fix it, include that as well. If you’re short on time, you can also email documentation bug reports to (behavioral bugs can be sent to ). ‘docs@’ is a mailing list run by volunteers; your request will be noticed, though it may take a while to be processed. See also ........ Documentation bugs(1) A list of documentation bugs that have been submitted to the Python issue tracker. Issue Tracking(2) Overview of the process involved in reporting an improvement on the tracker. Helping with Documentation(3) Comprehensive guide for individuals that are interested in contributing to Python documentation. ---------- Footnotes ---------- (1) https://bugs.python.org/issue?@filter=status&@filter=components&components=4&status=1&@columns=id,activity,title,status&@sort=-activity (2) https://devguide.python.org/tracker/ (3) https://devguide.python.org/docquality/#helping-with-documentation  File: python.info, Node: Using the Python issue tracker, Next: Getting started contributing to Python yourself, Prev: Documentation bugs, Up: Dealing with Bugs 14.2 Using the Python issue tracker =================================== Bug reports for Python itself should be submitted via the Python Bug Tracker (‘https://bugs.python.org/’). The bug tracker offers a Web form which allows pertinent information to be entered and submitted to the developers. The first step in filing a report is to determine whether the problem has already been reported. The advantage in doing so, aside from saving the developers time, is that you learn what has been done to fix it; it may be that the problem has already been fixed for the next release, or additional information is needed (in which case you are welcome to provide it if you can!). To do this, search the bug database using the search box on the top of the page. If the problem you’re reporting is not already in the bug tracker, go back to the Python Bug Tracker and log in. If you don’t already have a tracker account, select the “Register” link or, if you use OpenID, one of the OpenID provider logos in the sidebar. It is not possible to submit a bug report anonymously. Being now logged in, you can submit a bug. Select the “Create New” link in the sidebar to open the bug reporting form. The submission form has a number of fields. For the “Title” field, enter a `very' short description of the problem; less than ten words is good. In the “Type” field, select the type of your problem; also select the “Component” and “Versions” to which the bug relates. In the “Comment” field, describe the problem in detail, including what you expected to happen and what did happen. Be sure to include whether any extension modules were involved, and what hardware and software platform you were using (including version information as appropriate). Each bug report will be assigned to a developer who will determine what needs to be done to correct the problem. You will receive an update each time action is taken on the bug. See also ........ How to Report Bugs Effectively(1) Article which goes into some detail about how to create a useful bug report. This describes what kind of information is useful and why it is useful. Bug Report Writing Guidelines(2) Information about writing a good bug report. Some of this is specific to the Mozilla project, but describes general good practices. ---------- Footnotes ---------- (1) https://www.chiark.greenend.org.uk/~sgtatham/bugs.html (2) https://developer.mozilla.org/en-US/docs/Mozilla/QA/Bug_writing_guidelines  File: python.info, Node: Getting started contributing to Python yourself, Prev: Using the Python issue tracker, Up: Dealing with Bugs 14.3 Getting started contributing to Python yourself ==================================================== Beyond just reporting bugs that you find, you are also welcome to submit patches to fix them. You can find more information on how to get started patching Python in the Python Developer’s Guide(1). If you have questions, the core-mentorship mailing list(2) is a friendly place to get answers to any and all questions pertaining to the process of fixing issues in Python. ---------- Footnotes ---------- (1) https://devguide.python.org/ (2) https://mail.python.org/mailman3/lists/core-mentorship.python.org/  File: python.info, Node: Copyright, Next: History and License, Prev: Dealing with Bugs, Up: Top 15 Copyright ************ Python and this documentation is: Copyright © 2001-2021 Python Software Foundation. All rights reserved. Copyright © 2000 BeOpen.com. All rights reserved. Copyright © 1995-2000 Corporation for National Research Initiatives. All rights reserved. Copyright © 1991-1995 Stichting Mathematisch Centrum. All rights reserved. __________________________________________________________________ See *note History and License: 4096. for complete license and permissions information.  File: python.info, Node: History and License, Next: Distributing Python Modules Legacy version, Prev: Copyright, Up: Top 16 History and License ********************** * Menu: * History of the software:: * Terms and conditions for accessing or otherwise using Python:: * Licenses and Acknowledgements for Incorporated Software::  File: python.info, Node: History of the software, Next: Terms and conditions for accessing or otherwise using Python, Up: History and License 16.1 History of the software ============================ Python was created in the early 1990s by Guido van Rossum at Stichting Mathematisch Centrum (CWI, see ‘https://www.cwi.nl/’) in the Netherlands as a successor of a language called ABC. Guido remains Python’s principal author, although it includes many contributions from others. In 1995, Guido continued his work on Python at the Corporation for National Research Initiatives (CNRI, see ‘https://www.cnri.reston.va.us/’) in Reston, Virginia where he released several versions of the software. In May 2000, Guido and the Python core development team moved to BeOpen.com to form the BeOpen PythonLabs team. In October of the same year, the PythonLabs team moved to Digital Creations (now Zope Corporation; see ‘https://www.zope.org/’). In 2001, the Python Software Foundation (PSF, see ‘https://www.python.org/psf/’) was formed, a non-profit organization created specifically to own Python-related Intellectual Property. Zope Corporation is a sponsoring member of the PSF. All Python releases are Open Source (see ‘https://opensource.org/’ for the Open Source Definition). Historically, most, but not all, Python releases have also been GPL-compatible; the table below summarizes the various releases. Release Derived from Year Owner GPL compatible? ------------------------------------------------------------------------------------------------ 0.9.0 thru 1.2 n/a 1991-1995 CWI yes 1.3 thru 1.5.2 1.2 1995-1999 CNRI yes 1.6 1.5.2 2000 CNRI no 2.0 1.6 2000 BeOpen.com no 1.6.1 1.6 2001 CNRI no 2.1 2.0+1.6.1 2001 PSF no 2.0.1 2.0+1.6.1 2001 PSF yes 2.1.1 2.1+2.0.1 2001 PSF yes 2.1.2 2.1.1 2002 PSF yes 2.1.3 2.1.2 2002 PSF yes 2.2 and above 2.1.1 2001-now PSF yes Note: GPL-compatible doesn’t mean that we’re distributing Python under the GPL. All Python licenses, unlike the GPL, let you distribute a modified version without making your changes open source. The GPL-compatible licenses make it possible to combine Python with other software that is released under the GPL; the others don’t. Thanks to the many outside volunteers who have worked under Guido’s direction to make these releases possible.  File: python.info, Node: Terms and conditions for accessing or otherwise using Python, Next: Licenses and Acknowledgements for Incorporated Software, Prev: History of the software, Up: History and License 16.2 Terms and conditions for accessing or otherwise using Python ================================================================= Python software and documentation are licensed under the *note PSF License Agreement: 409b. Starting with Python 3.8.6, examples, recipes, and other code in the documentation are dual licensed under the PSF License Agreement and the *note Zero-Clause BSD license: 409c. Some software incorporated into Python is under different licenses. The licenses are listed with code falling under that license. See *note Licenses and Acknowledgements for Incorporated Software: 409d. for an incomplete list of these licenses. * Menu: * PSF LICENSE AGREEMENT FOR PYTHON 3.8.9: PSF LICENSE AGREEMENT FOR PYTHON 3 8 9. * BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0: BEOPEN COM LICENSE AGREEMENT FOR PYTHON 2 0. * CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1: CNRI LICENSE AGREEMENT FOR PYTHON 1 6 1. * CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 2. * ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3.8.9 DOCUMENTATION: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 8 9 DOCUMENTATION.  File: python.info, Node: PSF LICENSE AGREEMENT FOR PYTHON 3 8 9, Next: BEOPEN COM LICENSE AGREEMENT FOR PYTHON 2 0, Up: Terms and conditions for accessing or otherwise using Python 16.2.1 PSF LICENSE AGREEMENT FOR PYTHON 3.8.9 --------------------------------------------- 1. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"), and the Individual or Organization ("Licensee") accessing and otherwise using Python 3.8.9 software in source or binary form and its associated documentation. 2. Subject to the terms and conditions of this License Agreement, PSF hereby grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce, analyze, test, perform and/or display publicly, prepare derivative works, distribute, and otherwise use Python 3.8.9 alone or in any derivative version, provided, however, that PSF's License Agreement and PSF's notice of copyright, i.e., "Copyright © 2001-2021 Python Software Foundation; All Rights Reserved" are retained in Python 3.8.9 alone or in any derivative version prepared by Licensee. 3. 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File: python.info, Node: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 2, Next: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 8 9 DOCUMENTATION, Prev: CNRI LICENSE AGREEMENT FOR PYTHON 1 6 1, Up: Terms and conditions for accessing or otherwise using Python 16.2.4 CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2 --------------------------------------------------------- Copyright © 1991 - 1995, Stichting Mathematisch Centrum Amsterdam, The Netherlands. All rights reserved. Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Stichting Mathematisch Centrum or CWI not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  File: python.info, Node: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 8 9 DOCUMENTATION, Prev: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 2, Up: Terms and conditions for accessing or otherwise using Python 16.2.5 ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3.8.9 DOCUMENTATION ------------------------------------------------------------------------- Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  File: python.info, Node: Licenses and Acknowledgements for Incorporated Software, Prev: Terms and conditions for accessing or otherwise using Python, Up: History and License 16.3 Licenses and Acknowledgements for Incorporated Software ============================================================ This section is an incomplete, but growing list of licenses and acknowledgements for third-party software incorporated in the Python distribution. * Menu: * Mersenne Twister:: * Sockets: Sockets<2>. * Asynchronous socket services:: * Cookie management:: * Execution tracing:: * UUencode and UUdecode functions:: * XML Remote Procedure Calls:: * test_epoll:: * Select kqueue:: * SipHash24:: * strtod and dtoa:: * OpenSSL:: * expat:: * libffi:: * zlib: zlib<3>. * cfuhash:: * libmpdec:: * W3C C14N test suite::  File: python.info, Node: Mersenne Twister, Next: Sockets<2>, Up: Licenses and Acknowledgements for Incorporated Software 16.3.1 Mersenne Twister ----------------------- The ‘_random’ module includes code based on a download from ‘http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html’. The following are the verbatim comments from the original code: A C-program for MT19937, with initialization improved 2002/1/26. Coded by Takuji Nishimura and Makoto Matsumoto. Before using, initialize the state by using init_genrand(seed) or init_by_array(init_key, key_length). Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. The names of its contributors may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Any feedback is very welcome. http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)  File: python.info, Node: Sockets<2>, Next: Asynchronous socket services, Prev: Mersenne Twister, Up: Licenses and Acknowledgements for Incorporated Software 16.3.2 Sockets -------------- The *note socket: ef. module uses the functions, ‘getaddrinfo()’, and ‘getnameinfo()’, which are coded in separate source files from the WIDE Project, ‘http://www.wide.ad.jp/’. Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the project nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  File: python.info, Node: Asynchronous socket services, Next: Cookie management, Prev: Sockets<2>, Up: Licenses and Acknowledgements for Incorporated Software 16.3.3 Asynchronous socket services ----------------------------------- The *note asynchat: 9. and *note asyncore: b. modules contain the following notice: Copyright 1996 by Sam Rushing All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Sam Rushing not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  File: python.info, Node: Cookie management, Next: Execution tracing, Prev: Asynchronous socket services, Up: Licenses and Acknowledgements for Incorporated Software 16.3.4 Cookie management ------------------------ The *note http.cookies: 96. module contains the following notice: Copyright 2000 by Timothy O'Malley All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Timothy O'Malley not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. Timothy O'Malley DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL Timothy O'Malley BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  File: python.info, Node: Execution tracing, Next: UUencode and UUdecode functions, Prev: Cookie management, Up: Licenses and Acknowledgements for Incorporated Software 16.3.5 Execution tracing ------------------------ The *note trace: 112. module contains the following notice: portions copyright 2001, Autonomous Zones Industries, Inc., all rights... err... reserved and offered to the public under the terms of the Python 2.2 license. Author: Zooko O'Whielacronx http://zooko.com/ mailto:zooko@zooko.com Copyright 2000, Mojam Media, Inc., all rights reserved. Author: Skip Montanaro Copyright 1999, Bioreason, Inc., all rights reserved. Author: Andrew Dalke Copyright 1995-1997, Automatrix, Inc., all rights reserved. Author: Skip Montanaro Copyright 1991-1995, Stichting Mathematisch Centrum, all rights reserved. Permission to use, copy, modify, and distribute this Python software and its associated documentation for any purpose without fee is hereby granted, provided that the above copyright notice appears in all copies, and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of neither Automatrix, Bioreason or Mojam Media be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.  File: python.info, Node: UUencode and UUdecode functions, Next: XML Remote Procedure Calls, Prev: Execution tracing, Up: Licenses and Acknowledgements for Incorporated Software 16.3.6 UUencode and UUdecode functions -------------------------------------- The *note uu: 123. module contains the following notice: Copyright 1994 by Lance Ellinghouse Cathedral City, California Republic, United States of America. All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Lance Ellinghouse not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. Modified by Jack Jansen, CWI, July 1995: - Use binascii module to do the actual line-by-line conversion between ascii and binary. This results in a 1000-fold speedup. The C version is still 5 times faster, though. - Arguments more compliant with Python standard  File: python.info, Node: XML Remote Procedure Calls, Next: test_epoll, Prev: UUencode and UUdecode functions, Up: Licenses and Acknowledgements for Incorporated Software 16.3.7 XML Remote Procedure Calls --------------------------------- The *note xmlrpc.client: 13f. module contains the following notice: The XML-RPC client interface is Copyright (c) 1999-2002 by Secret Labs AB Copyright (c) 1999-2002 by Fredrik Lundh By obtaining, using, and/or copying this software and/or its associated documentation, you agree that you have read, understood, and will comply with the following terms and conditions: Permission to use, copy, modify, and distribute this software and its associated documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appears in all copies, and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Secret Labs AB or the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT- ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  File: python.info, Node: test_epoll, Next: Select kqueue, Prev: XML Remote Procedure Calls, Up: Licenses and Acknowledgements for Incorporated Software 16.3.8 test_epoll ----------------- The ‘test_epoll’ module contains the following notice: Copyright (c) 2001-2006 Twisted Matrix Laboratories. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  File: python.info, Node: Select kqueue, Next: SipHash24, Prev: test_epoll, Up: Licenses and Acknowledgements for Incorporated Software 16.3.9 Select kqueue -------------------- The *note select: e5. module contains the following notice for the kqueue interface: Copyright (c) 2000 Doug White, 2006 James Knight, 2007 Christian Heimes All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  File: python.info, Node: SipHash24, Next: strtod and dtoa, Prev: Select kqueue, Up: Licenses and Acknowledgements for Incorporated Software 16.3.10 SipHash24 ----------------- The file ‘Python/pyhash.c’ contains Marek Majkowski’ implementation of Dan Bernstein’s SipHash24 algorithm. It contains the following note: Copyright (c) 2013 Marek Majkowski Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. Original location: https://github.com/majek/csiphash/ Solution inspired by code from: Samuel Neves (supercop/crypto_auth/siphash24/little) djb (supercop/crypto_auth/siphash24/little2) Jean-Philippe Aumasson (https://131002.net/siphash/siphash24.c)  File: python.info, Node: strtod and dtoa, Next: OpenSSL, Prev: SipHash24, Up: Licenses and Acknowledgements for Incorporated Software 16.3.11 strtod and dtoa ----------------------- The file ‘Python/dtoa.c’, which supplies C functions dtoa and strtod for conversion of C doubles to and from strings, is derived from the file of the same name by David M. Gay, currently available from ‘http://www.netlib.org/fp/’. The original file, as retrieved on March 16, 2009, contains the following copyright and licensing notice: /**************************************************************** * * The author of this software is David M. Gay. * * Copyright (c) 1991, 2000, 2001 by Lucent Technologies. * * Permission to use, copy, modify, and distribute this software for any * purpose without fee is hereby granted, provided that this entire notice * is included in all copies of any software which is or includes a copy * or modification of this software and in all copies of the supporting * documentation for such software. * * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. * ***************************************************************/  File: python.info, Node: OpenSSL, Next: expat, Prev: strtod and dtoa, Up: Licenses and Acknowledgements for Incorporated Software 16.3.12 OpenSSL --------------- The modules *note hashlib: 8d, *note posix: d1, *note ssl: f3, *note crypt: 29. use the OpenSSL library for added performance if made available by the operating system. Additionally, the Windows and Mac OS X installers for Python may include a copy of the OpenSSL libraries, so we include a copy of the OpenSSL license here: LICENSE ISSUES ============== The OpenSSL toolkit stays under a dual license, i.e. both the conditions of the OpenSSL License and the original SSLeay license apply to the toolkit. See below for the actual license texts. Actually both licenses are BSD-style Open Source licenses. In case of any license issues related to OpenSSL please contact openssl-core@openssl.org. OpenSSL License --------------- /* ==================================================================== * Copyright (c) 1998-2008 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ Original SSLeay License ----------------------- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */  File: python.info, Node: expat, Next: libffi, Prev: OpenSSL, Up: Licenses and Acknowledgements for Incorporated Software 16.3.13 expat ------------- The ‘pyexpat’ extension is built using an included copy of the expat sources unless the build is configured ‘--with-system-expat’: Copyright (c) 1998, 1999, 2000 Thai Open Source Software Center Ltd and Clark Cooper Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  File: python.info, Node: libffi, Next: zlib<3>, Prev: expat, Up: Licenses and Acknowledgements for Incorporated Software 16.3.14 libffi -------------- The ‘_ctypes’ extension is built using an included copy of the libffi sources unless the build is configured ‘--with-system-libffi’: Copyright (c) 1996-2008 Red Hat, Inc and others. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ``Software''), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  File: python.info, Node: zlib<3>, Next: cfuhash, Prev: libffi, Up: Licenses and Acknowledgements for Incorporated Software 16.3.15 zlib ------------ The *note zlib: 144. extension is built using an included copy of the zlib sources if the zlib version found on the system is too old to be used for the build: Copyright (C) 1995-2011 Jean-loup Gailly and Mark Adler This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. Jean-loup Gailly Mark Adler jloup@gzip.org madler@alumni.caltech.edu  File: python.info, Node: cfuhash, Next: libmpdec, Prev: zlib<3>, Up: Licenses and Acknowledgements for Incorporated Software 16.3.16 cfuhash --------------- The implementation of the hash table used by the *note tracemalloc: 114. is based on the cfuhash project: Copyright (c) 2005 Don Owens All rights reserved. This code is released under the BSD license: Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  File: python.info, Node: libmpdec, Next: W3C C14N test suite, Prev: cfuhash, Up: Licenses and Acknowledgements for Incorporated Software 16.3.17 libmpdec ---------------- The ‘_decimal’ module is built using an included copy of the libmpdec library unless the build is configured ‘--with-system-libmpdec’: Copyright (c) 2008-2016 Stefan Krah. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  File: python.info, Node: W3C C14N test suite, Prev: libmpdec, Up: Licenses and Acknowledgements for Incorporated Software 16.3.18 W3C C14N test suite --------------------------- The C14N 2.0 test suite in the *note test: 105. package (‘Lib/test/xmltestdata/c14n-20/’) was retrieved from the W3C website at ‘https://www.w3.org/TR/xml-c14n2-testcases/’ and is distributed under the 3-clause BSD license: Copyright (c) 2013 W3C(R) (MIT, ERCIM, Keio, Beihang), All Rights Reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of works must retain the original copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the original copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the W3C nor the names of its contributors may be used to endorse or promote products derived from this work without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  File: python.info, Node: Distributing Python Modules Legacy version, Next: Installing Python Modules Legacy version, Prev: History and License, Up: Top 17 Distributing Python Modules (Legacy version) *********************************************** Authors: Greg Ward, Anthony Baxter Email: See also ........ *note Distributing Python Modules: 7f6. The up to date module distribution documentations Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. Note: This guide only covers the basic tools for building and distributing extensions that are provided as part of this version of Python. Third party tools offer easier to use and more secure alternatives. Refer to the quick recommendations section(1) in the Python Packaging User Guide for more information. This document describes the Python Distribution Utilities (“Distutils”) from the module developer’s point of view, describing the underlying capabilities that ‘setuptools’ builds on to allow Python developers to make Python modules and extensions readily available to a wider audience. * Menu: * An Introduction to Distutils:: * Writing the Setup Script:: * Writing the Setup Configuration File:: * Creating a Source Distribution:: * Creating Built Distributions:: * Distutils Examples:: * Extending Distutils:: * Command Reference:: * API Reference:: ---------- Footnotes ---------- (1) https://packaging.python.org/guides/tool-recommendations/  File: python.info, Node: An Introduction to Distutils, Next: Writing the Setup Script, Up: Distributing Python Modules Legacy version 17.1 An Introduction to Distutils ================================= Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. This document covers using the Distutils to distribute your Python modules, concentrating on the role of developer/distributor: if you’re looking for information on installing Python modules, you should refer to the *note Installing Python Modules (Legacy version): 7f7. chapter. * Menu: * Concepts & Terminology:: * A Simple Example: A Simple Example<2>. * General Python terminology:: * Distutils-specific terminology::  File: python.info, Node: Concepts & Terminology, Next: A Simple Example<2>, Up: An Introduction to Distutils 17.1.1 Concepts & Terminology ----------------------------- Using the Distutils is quite simple, both for module developers and for users/administrators installing third-party modules. As a developer, your responsibilities (apart from writing solid, well-documented and well-tested code, of course!) are: * write a setup script (‘setup.py’ by convention) * (optional) write a setup configuration file * create a source distribution * (optional) create one or more built (binary) distributions Each of these tasks is covered in this document. Not all module developers have access to a multitude of platforms, so it’s not always feasible to expect them to create a multitude of built distributions. It is hoped that a class of intermediaries, called `packagers', will arise to address this need. Packagers will take source distributions released by module developers, build them on one or more platforms, and release the resulting built distributions. Thus, users on the most popular platforms will be able to install most popular Python module distributions in the most natural way for their platform, without having to run a single setup script or compile a line of code.  File: python.info, Node: A Simple Example<2>, Next: General Python terminology, Prev: Concepts & Terminology, Up: An Introduction to Distutils 17.1.2 A Simple Example ----------------------- The setup script is usually quite simple, although since it’s written in Python, there are no arbitrary limits to what you can do with it, though you should be careful about putting arbitrarily expensive operations in your setup script. Unlike, say, Autoconf-style configure scripts, the setup script may be run multiple times in the course of building and installing your module distribution. If all you want to do is distribute a module called ‘foo’, contained in a file ‘foo.py’, then your setup script can be as simple as this: from distutils.core import setup setup(name='foo', version='1.0', py_modules=['foo'], ) Some observations: * most information that you supply to the Distutils is supplied as keyword arguments to the ‘setup()’ function * those keyword arguments fall into two categories: package metadata (name, version number) and information about what’s in the package (a list of pure Python modules, in this case) * modules are specified by module name, not filename (the same will hold true for packages and extensions) * it’s recommended that you supply a little more metadata, in particular your name, email address and a URL for the project (see section *note Writing the Setup Script: 40bf. for an example) To create a source distribution for this module, you would create a setup script, ‘setup.py’, containing the above code, and run this command from a terminal: python setup.py sdist For Windows, open a command prompt window (Start ‣ Accessories) and change the command to: setup.py sdist ‘sdist’ will create an archive file (e.g., tarball on Unix, ZIP file on Windows) containing your setup script ‘setup.py’, and your module ‘foo.py’. The archive file will be named ‘foo-1.0.tar.gz’ (or ‘.zip’), and will unpack into a directory ‘foo-1.0’. If an end-user wishes to install your ‘foo’ module, all they have to do is download ‘foo-1.0.tar.gz’ (or ‘.zip’), unpack it, and—from the ‘foo-1.0’ directory—run python setup.py install which will ultimately copy ‘foo.py’ to the appropriate directory for third-party modules in their Python installation. This simple example demonstrates some fundamental concepts of the Distutils. First, both developers and installers have the same basic user interface, i.e. the setup script. The difference is which Distutils `commands' they use: the ‘sdist’ command is almost exclusively for module developers, while ‘install’ is more often for installers (although most developers will want to install their own code occasionally). If you want to make things really easy for your users, you can create one or more built distributions for them. For instance, if you are running on a Windows machine, and want to make things easy for other Windows users, you can create an executable installer (the most appropriate type of built distribution for this platform) with the ‘bdist_wininst’ command. For example: python setup.py bdist_wininst will create an executable installer, ‘foo-1.0.win32.exe’, in the current directory. Other useful built distribution formats are RPM, implemented by the ‘bdist_rpm’ command, Solaris ‘pkgtool’ (‘bdist_pkgtool’), and HP-UX ‘swinstall’ (‘bdist_sdux’). For example, the following command will create an RPM file called ‘foo-1.0.noarch.rpm’: python setup.py bdist_rpm (The ‘bdist_rpm’ command uses the ‘rpm’ executable, therefore this has to be run on an RPM-based system such as Red Hat Linux, SuSE Linux, or Mandrake Linux.) You can find out what distribution formats are available at any time by running python setup.py bdist --help-formats  File: python.info, Node: General Python terminology, Next: Distutils-specific terminology, Prev: A Simple Example<2>, Up: An Introduction to Distutils 17.1.3 General Python terminology --------------------------------- If you’re reading this document, you probably have a good idea of what modules, extensions, and so forth are. Nevertheless, just to be sure that everyone is operating from a common starting point, we offer the following glossary of common Python terms: module the basic unit of code reusability in Python: a block of code imported by some other code. Three types of modules concern us here: pure Python modules, extension modules, and packages. pure Python module a module written in Python and contained in a single ‘.py’ file (and possibly associated ‘.pyc’ files). Sometimes referred to as a “pure module.” extension module a module written in the low-level language of the Python implementation: C/C++ for Python, Java for Jython. Typically contained in a single dynamically loadable pre-compiled file, e.g. a shared object (‘.so’) file for Python extensions on Unix, a DLL (given the ‘.pyd’ extension) for Python extensions on Windows, or a Java class file for Jython extensions. (Note that currently, the Distutils only handles C/C++ extensions for Python.) package a module that contains other modules; typically contained in a directory in the filesystem and distinguished from other directories by the presence of a file ‘__init__.py’. root package the root of the hierarchy of packages. (This isn’t really a package, since it doesn’t have an ‘__init__.py’ file. But we have to call it something.) The vast majority of the standard library is in the root package, as are many small, standalone third-party modules that don’t belong to a larger module collection. Unlike regular packages, modules in the root package can be found in many directories: in fact, every directory listed in ‘sys.path’ contributes modules to the root package.  File: python.info, Node: Distutils-specific terminology, Prev: General Python terminology, Up: An Introduction to Distutils 17.1.4 Distutils-specific terminology ------------------------------------- The following terms apply more specifically to the domain of distributing Python modules using the Distutils: module distribution a collection of Python modules distributed together as a single downloadable resource and meant to be installed `en masse'. Examples of some well-known module distributions are NumPy, SciPy, Pillow, or mxBase. (This would be called a `package', except that term is already taken in the Python context: a single module distribution may contain zero, one, or many Python packages.) pure module distribution a module distribution that contains only pure Python modules and packages. Sometimes referred to as a “pure distribution.” non-pure module distribution a module distribution that contains at least one extension module. Sometimes referred to as a “non-pure distribution.” distribution root the top-level directory of your source tree (or source distribution); the directory where ‘setup.py’ exists. Generally ‘setup.py’ will be run from this directory.  File: python.info, Node: Writing the Setup Script, Next: Writing the Setup Configuration File, Prev: An Introduction to Distutils, Up: Distributing Python Modules Legacy version 17.2 Writing the Setup Script ============================= Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. The setup script is the centre of all activity in building, distributing, and installing modules using the Distutils. The main purpose of the setup script is to describe your module distribution to the Distutils, so that the various commands that operate on your modules do the right thing. As we saw in section *note A Simple Example: 40be. above, the setup script consists mainly of a call to ‘setup()’, and most information supplied to the Distutils by the module developer is supplied as keyword arguments to ‘setup()’. Here’s a slightly more involved example, which we’ll follow for the next couple of sections: the Distutils’ own setup script. (Keep in mind that although the Distutils are included with Python 1.6 and later, they also have an independent existence so that Python 1.5.2 users can use them to install other module distributions. The Distutils’ own setup script, shown here, is used to install the package into Python 1.5.2.) #!/usr/bin/env python from distutils.core import setup setup(name='Distutils', version='1.0', description='Python Distribution Utilities', author='Greg Ward', author_email='gward@python.net', url='https://www.python.org/sigs/distutils-sig/', packages=['distutils', 'distutils.command'], ) There are only two differences between this and the trivial one-file distribution presented in section *note A Simple Example: 40be.: more metadata, and the specification of pure Python modules by package, rather than by module. This is important since the Distutils consist of a couple of dozen modules split into (so far) two packages; an explicit list of every module would be tedious to generate and difficult to maintain. For more information on the additional meta-data, see section *note Additional meta-data: 40c6. Note that any pathnames (files or directories) supplied in the setup script should be written using the Unix convention, i.e. slash-separated. The Distutils will take care of converting this platform-neutral representation into whatever is appropriate on your current platform before actually using the pathname. This makes your setup script portable across operating systems, which of course is one of the major goals of the Distutils. In this spirit, all pathnames in this document are slash-separated. This, of course, only applies to pathnames given to Distutils functions. If you, for example, use standard Python functions such as *note glob.glob(): 5c6. or *note os.listdir(): a41. to specify files, you should be careful to write portable code instead of hardcoding path separators: glob.glob(os.path.join('mydir', 'subdir', '*.html')) os.listdir(os.path.join('mydir', 'subdir')) * Menu: * Listing whole packages:: * Listing individual modules:: * Describing extension modules:: * Relationships between Distributions and Packages:: * Installing Scripts:: * Installing Package Data:: * Installing Additional Files:: * Additional meta-data:: * Debugging the setup script::  File: python.info, Node: Listing whole packages, Next: Listing individual modules, Up: Writing the Setup Script 17.2.1 Listing whole packages ----------------------------- The ‘packages’ option tells the Distutils to process (build, distribute, install, etc.) all pure Python modules found in each package mentioned in the ‘packages’ list. In order to do this, of course, there has to be a correspondence between package names and directories in the filesystem. The default correspondence is the most obvious one, i.e. package *note distutils: 39. is found in the directory ‘distutils’ relative to the distribution root. Thus, when you say ‘packages = ['foo']’ in your setup script, you are promising that the Distutils will find a file ‘foo/__init__.py’ (which might be spelled differently on your system, but you get the idea) relative to the directory where your setup script lives. If you break this promise, the Distutils will issue a warning but still process the broken package anyway. If you use a different convention to lay out your source directory, that’s no problem: you just have to supply the ‘package_dir’ option to tell the Distutils about your convention. For example, say you keep all Python source under ‘lib’, so that modules in the “root package” (i.e., not in any package at all) are in ‘lib’, modules in the ‘foo’ package are in ‘lib/foo’, and so forth. Then you would put package_dir = {'': 'lib'} in your setup script. The keys to this dictionary are package names, and an empty package name stands for the root package. The values are directory names relative to your distribution root. In this case, when you say ‘packages = ['foo']’, you are promising that the file ‘lib/foo/__init__.py’ exists. Another possible convention is to put the ‘foo’ package right in ‘lib’, the ‘foo.bar’ package in ‘lib/bar’, etc. This would be written in the setup script as package_dir = {'foo': 'lib'} A ‘package: dir’ entry in the ‘package_dir’ dictionary implicitly applies to all packages below `package', so the ‘foo.bar’ case is automatically handled here. In this example, having ‘packages = ['foo', 'foo.bar']’ tells the Distutils to look for ‘lib/__init__.py’ and ‘lib/bar/__init__.py’. (Keep in mind that although ‘package_dir’ applies recursively, you must explicitly list all packages in ‘packages’: the Distutils will `not' recursively scan your source tree looking for any directory with an ‘__init__.py’ file.)  File: python.info, Node: Listing individual modules, Next: Describing extension modules, Prev: Listing whole packages, Up: Writing the Setup Script 17.2.2 Listing individual modules --------------------------------- For a small module distribution, you might prefer to list all modules rather than listing packages—especially the case of a single module that goes in the “root package” (i.e., no package at all). This simplest case was shown in section *note A Simple Example: 40be.; here is a slightly more involved example: py_modules = ['mod1', 'pkg.mod2'] This describes two modules, one of them in the “root” package, the other in the ‘pkg’ package. Again, the default package/directory layout implies that these two modules can be found in ‘mod1.py’ and ‘pkg/mod2.py’, and that ‘pkg/__init__.py’ exists as well. And again, you can override the package/directory correspondence using the ‘package_dir’ option.  File: python.info, Node: Describing extension modules, Next: Relationships between Distributions and Packages, Prev: Listing individual modules, Up: Writing the Setup Script 17.2.3 Describing extension modules ----------------------------------- Just as writing Python extension modules is a bit more complicated than writing pure Python modules, describing them to the Distutils is a bit more complicated. Unlike pure modules, it’s not enough just to list modules or packages and expect the Distutils to go out and find the right files; you have to specify the extension name, source file(s), and any compile/link requirements (include directories, libraries to link with, etc.). All of this is done through another keyword argument to ‘setup()’, the ‘ext_modules’ option. ‘ext_modules’ is just a list of *note Extension: 40cd. instances, each of which describes a single extension module. Suppose your distribution includes a single extension, called ‘foo’ and implemented by ‘foo.c’. If no additional instructions to the compiler/linker are needed, describing this extension is quite simple: Extension('foo', ['foo.c']) The ‘Extension’ class can be imported from *note distutils.core: 54. along with ‘setup()’. Thus, the setup script for a module distribution that contains only this one extension and nothing else might be: from distutils.core import setup, Extension setup(name='foo', version='1.0', ext_modules=[Extension('foo', ['foo.c'])], ) The ‘Extension’ class (actually, the underlying extension-building machinery implemented by the ‘build_ext’ command) supports a great deal of flexibility in describing Python extensions, which is explained in the following sections. * Menu: * Extension names and packages:: * Extension source files:: * Preprocessor options:: * Library options:: * Other options::  File: python.info, Node: Extension names and packages, Next: Extension source files, Up: Describing extension modules 17.2.3.1 Extension names and packages ..................................... The first argument to the *note Extension: 40cd. constructor is always the name of the extension, including any package names. For example, Extension('foo', ['src/foo1.c', 'src/foo2.c']) describes an extension that lives in the root package, while Extension('pkg.foo', ['src/foo1.c', 'src/foo2.c']) describes the same extension in the ‘pkg’ package. The source files and resulting object code are identical in both cases; the only difference is where in the filesystem (and therefore where in Python’s namespace hierarchy) the resulting extension lives. If you have a number of extensions all in the same package (or all under the same base package), use the ‘ext_package’ keyword argument to ‘setup()’. For example, setup(..., ext_package='pkg', ext_modules=[Extension('foo', ['foo.c']), Extension('subpkg.bar', ['bar.c'])], ) will compile ‘foo.c’ to the extension ‘pkg.foo’, and ‘bar.c’ to ‘pkg.subpkg.bar’.  File: python.info, Node: Extension source files, Next: Preprocessor options, Prev: Extension names and packages, Up: Describing extension modules 17.2.3.2 Extension source files ............................... The second argument to the *note Extension: 40cd. constructor is a list of source files. Since the Distutils currently only support C, C++, and Objective-C extensions, these are normally C/C++/Objective-C source files. (Be sure to use appropriate extensions to distinguish C++ source files: ‘.cc’ and ‘.cpp’ seem to be recognized by both Unix and Windows compilers.) However, you can also include SWIG interface (‘.i’) files in the list; the ‘build_ext’ command knows how to deal with SWIG extensions: it will run SWIG on the interface file and compile the resulting C/C++ file into your extension. This warning notwithstanding, options to SWIG can be currently passed like this: setup(..., ext_modules=[Extension('_foo', ['foo.i'], swig_opts=['-modern', '-I../include'])], py_modules=['foo'], ) Or on the commandline like this: > python setup.py build_ext --swig-opts="-modern -I../include" On some platforms, you can include non-source files that are processed by the compiler and included in your extension. Currently, this just means Windows message text (‘.mc’) files and resource definition (‘.rc’) files for Visual C++. These will be compiled to binary resource (‘.res’) files and linked into the executable.  File: python.info, Node: Preprocessor options, Next: Library options, Prev: Extension source files, Up: Describing extension modules 17.2.3.3 Preprocessor options ............................. Three optional arguments to *note Extension: 40cd. will help if you need to specify include directories to search or preprocessor macros to define/undefine: ‘include_dirs’, ‘define_macros’, and ‘undef_macros’. For example, if your extension requires header files in the ‘include’ directory under your distribution root, use the ‘include_dirs’ option: Extension('foo', ['foo.c'], include_dirs=['include']) You can specify absolute directories there; if you know that your extension will only be built on Unix systems with X11R6 installed to ‘/usr’, you can get away with Extension('foo', ['foo.c'], include_dirs=['/usr/include/X11']) You should avoid this sort of non-portable usage if you plan to distribute your code: it’s probably better to write C code like #include If you need to include header files from some other Python extension, you can take advantage of the fact that header files are installed in a consistent way by the Distutils ‘install_headers’ command. For example, the Numerical Python header files are installed (on a standard Unix installation) to ‘/usr/local/include/python1.5/Numerical’. (The exact location will differ according to your platform and Python installation.) Since the Python include directory—‘/usr/local/include/python1.5’ in this case—is always included in the search path when building Python extensions, the best approach is to write C code like #include If you must put the ‘Numerical’ include directory right into your header search path, though, you can find that directory using the Distutils *note distutils.sysconfig: 62. module: from distutils.sysconfig import get_python_inc incdir = os.path.join(get_python_inc(plat_specific=1), 'Numerical') setup(..., Extension(..., include_dirs=[incdir]), ) Even though this is quite portable—it will work on any Python installation, regardless of platform—it’s probably easier to just write your C code in the sensible way. You can define and undefine pre-processor macros with the ‘define_macros’ and ‘undef_macros’ options. ‘define_macros’ takes a list of ‘(name, value)’ tuples, where ‘name’ is the name of the macro to define (a string) and ‘value’ is its value: either a string or ‘None’. (Defining a macro ‘FOO’ to ‘None’ is the equivalent of a bare ‘#define FOO’ in your C source: with most compilers, this sets ‘FOO’ to the string ‘1’.) ‘undef_macros’ is just a list of macros to undefine. For example: Extension(..., define_macros=[('NDEBUG', '1'), ('HAVE_STRFTIME', None)], undef_macros=['HAVE_FOO', 'HAVE_BAR']) is the equivalent of having this at the top of every C source file: #define NDEBUG 1 #define HAVE_STRFTIME #undef HAVE_FOO #undef HAVE_BAR  File: python.info, Node: Library options, Next: Other options, Prev: Preprocessor options, Up: Describing extension modules 17.2.3.4 Library options ........................ You can also specify the libraries to link against when building your extension, and the directories to search for those libraries. The ‘libraries’ option is a list of libraries to link against, ‘library_dirs’ is a list of directories to search for libraries at link-time, and ‘runtime_library_dirs’ is a list of directories to search for shared (dynamically loaded) libraries at run-time. For example, if you need to link against libraries known to be in the standard library search path on target systems Extension(..., libraries=['gdbm', 'readline']) If you need to link with libraries in a non-standard location, you’ll have to include the location in ‘library_dirs’: Extension(..., library_dirs=['/usr/X11R6/lib'], libraries=['X11', 'Xt']) (Again, this sort of non-portable construct should be avoided if you intend to distribute your code.)  File: python.info, Node: Other options, Prev: Library options, Up: Describing extension modules 17.2.3.5 Other options ...................... There are still some other options which can be used to handle special cases. The ‘optional’ option is a boolean; if it is true, a build failure in the extension will not abort the build process, but instead simply not install the failing extension. The ‘extra_objects’ option is a list of object files to be passed to the linker. These files must not have extensions, as the default extension for the compiler is used. ‘extra_compile_args’ and ‘extra_link_args’ can be used to specify additional command line options for the respective compiler and linker command lines. ‘export_symbols’ is only useful on Windows. It can contain a list of symbols (functions or variables) to be exported. This option is not needed when building compiled extensions: Distutils will automatically add ‘initmodule’ to the list of exported symbols. The ‘depends’ option is a list of files that the extension depends on (for example header files). The build command will call the compiler on the sources to rebuild extension if any on this files has been modified since the previous build.  File: python.info, Node: Relationships between Distributions and Packages, Next: Installing Scripts, Prev: Describing extension modules, Up: Writing the Setup Script 17.2.4 Relationships between Distributions and Packages ------------------------------------------------------- A distribution may relate to packages in three specific ways: 1. It can require packages or modules. 2. It can provide packages or modules. 3. It can obsolete packages or modules. These relationships can be specified using keyword arguments to the *note distutils.core.setup(): 38b8. function. Dependencies on other Python modules and packages can be specified by supplying the `requires' keyword argument to ‘setup()’. The value must be a list of strings. Each string specifies a package that is required, and optionally what versions are sufficient. To specify that any version of a module or package is required, the string should consist entirely of the module or package name. Examples include ‘'mymodule'’ and ‘'xml.parsers.expat'’. If specific versions are required, a sequence of qualifiers can be supplied in parentheses. Each qualifier may consist of a comparison operator and a version number. The accepted comparison operators are: < > == <= >= != These can be combined by using multiple qualifiers separated by commas (and optional whitespace). In this case, all of the qualifiers must be matched; a logical AND is used to combine the evaluations. Let’s look at a bunch of examples: Requires Expression Explanation --------------------------------------------------------------------------------- ‘==1.0’ Only version ‘1.0’ is compatible ‘>1.0, !=1.5.1, <2.0’ Any version after ‘1.0’ and before ‘2.0’ is compatible, except ‘1.5.1’ Now that we can specify dependencies, we also need to be able to specify what we provide that other distributions can require. This is done using the `provides' keyword argument to ‘setup()’. The value for this keyword is a list of strings, each of which names a Python module or package, and optionally identifies the version. If the version is not specified, it is assumed to match that of the distribution. Some examples: Provides Expression Explanation ----------------------------------------------------------------------------- ‘mypkg’ Provide ‘mypkg’, using the distribution version ‘mypkg (1.1)’ Provide ‘mypkg’ version 1.1, regardless of the distribution version A package can declare that it obsoletes other packages using the `obsoletes' keyword argument. The value for this is similar to that of the `requires' keyword: a list of strings giving module or package specifiers. Each specifier consists of a module or package name optionally followed by one or more version qualifiers. Version qualifiers are given in parentheses after the module or package name. The versions identified by the qualifiers are those that are obsoleted by the distribution being described. If no qualifiers are given, all versions of the named module or package are understood to be obsoleted.  File: python.info, Node: Installing Scripts, Next: Installing Package Data, Prev: Relationships between Distributions and Packages, Up: Writing the Setup Script 17.2.5 Installing Scripts ------------------------- So far we have been dealing with pure and non-pure Python modules, which are usually not run by themselves but imported by scripts. Scripts are files containing Python source code, intended to be started from the command line. Scripts don’t require Distutils to do anything very complicated. The only clever feature is that if the first line of the script starts with ‘#!’ and contains the word “python”, the Distutils will adjust the first line to refer to the current interpreter location. By default, it is replaced with the current interpreter location. The ‘--executable’ (or ‘-e’) option will allow the interpreter path to be explicitly overridden. The ‘scripts’ option simply is a list of files to be handled in this way. From the PyXML setup script: setup(..., scripts=['scripts/xmlproc_parse', 'scripts/xmlproc_val'] ) Changed in version 3.1: All the scripts will also be added to the ‘MANIFEST’ file if no template is provided. See *note Specifying the files to distribute: 38bb.  File: python.info, Node: Installing Package Data, Next: Installing Additional Files, Prev: Installing Scripts, Up: Writing the Setup Script 17.2.6 Installing Package Data ------------------------------ Often, additional files need to be installed into a package. These files are often data that’s closely related to the package’s implementation, or text files containing documentation that might be of interest to programmers using the package. These files are called `package data'. Package data can be added to packages using the ‘package_data’ keyword argument to the ‘setup()’ function. The value must be a mapping from package name to a list of relative path names that should be copied into the package. The paths are interpreted as relative to the directory containing the package (information from the ‘package_dir’ mapping is used if appropriate); that is, the files are expected to be part of the package in the source directories. They may contain glob patterns as well. The path names may contain directory portions; any necessary directories will be created in the installation. For example, if a package should contain a subdirectory with several data files, the files can be arranged like this in the source tree: setup.py src/ mypkg/ __init__.py module.py data/ tables.dat spoons.dat forks.dat The corresponding call to ‘setup()’ might be: setup(..., packages=['mypkg'], package_dir={'mypkg': 'src/mypkg'}, package_data={'mypkg': ['data/*.dat']}, ) Changed in version 3.1: All the files that match ‘package_data’ will be added to the ‘MANIFEST’ file if no template is provided. See *note Specifying the files to distribute: 38bb.  File: python.info, Node: Installing Additional Files, Next: Additional meta-data, Prev: Installing Package Data, Up: Writing the Setup Script 17.2.7 Installing Additional Files ---------------------------------- The ‘data_files’ option can be used to specify additional files needed by the module distribution: configuration files, message catalogs, data files, anything which doesn’t fit in the previous categories. ‘data_files’ specifies a sequence of (`directory', `files') pairs in the following way: setup(..., data_files=[('bitmaps', ['bm/b1.gif', 'bm/b2.gif']), ('config', ['cfg/data.cfg'])], ) Each (`directory', `files') pair in the sequence specifies the installation directory and the files to install there. Each file name in `files' is interpreted relative to the ‘setup.py’ script at the top of the package source distribution. Note that you can specify the directory where the data files will be installed, but you cannot rename the data files themselves. The `directory' should be a relative path. It is interpreted relative to the installation prefix (Python’s ‘sys.prefix’ for system installations; ‘site.USER_BASE’ for user installations). Distutils allows `directory' to be an absolute installation path, but this is discouraged since it is incompatible with the wheel packaging format. No directory information from `files' is used to determine the final location of the installed file; only the name of the file is used. You can specify the ‘data_files’ options as a simple sequence of files without specifying a target directory, but this is not recommended, and the ‘install’ command will print a warning in this case. To install data files directly in the target directory, an empty string should be given as the directory. Changed in version 3.1: All the files that match ‘data_files’ will be added to the ‘MANIFEST’ file if no template is provided. See *note Specifying the files to distribute: 38bb.  File: python.info, Node: Additional meta-data, Next: Debugging the setup script, Prev: Installing Additional Files, Up: Writing the Setup Script 17.2.8 Additional meta-data --------------------------- The setup script may include additional meta-data beyond the name and version. This information includes: Meta-Data Description Value Notes ---------------------------------------------------------------------------------------------- ‘name’ name of the package short string (1) ‘version’ version of this release short string (1)(2) ‘author’ package author’s name short string (3) ‘author_email’ email address of the package email address (3) author ‘maintainer’ package maintainer’s name short string (3) ‘maintainer_email’ email address of the package email address (3) maintainer ‘url’ home page for the package URL (1) ‘description’ short, summary description of short string the package ‘long_description’ longer description of the long string (4) package ‘download_url’ location where the package URL may be downloaded ‘classifiers’ a list of classifiers list of strings (6)(7) ‘platforms’ a list of platforms list of strings (6)(8) ‘keywords’ a list of keywords list of strings (6)(8) ‘license’ license for the package short string (5) Notes: 1. These fields are required. 2. It is recommended that versions take the form `major.minor[.patch[.sub]]'. 3. Either the author or the maintainer must be identified. If maintainer is provided, distutils lists it as the author in ‘PKG-INFO’. 4. The ‘long_description’ field is used by PyPI when you publish a package, to build its project page. 5. The ‘license’ field is a text indicating the license covering the package where the license is not a selection from the “License” Trove classifiers. See the ‘Classifier’ field. Notice that there’s a ‘licence’ distribution option which is deprecated but still acts as an alias for ‘license’. 6. This field must be a list. 7. The valid classifiers are listed on PyPI(1). 8. To preserve backward compatibility, this field also accepts a string. If you pass a comma-separated string ‘'foo, bar'’, it will be converted to ‘['foo', 'bar']’, Otherwise, it will be converted to a list of one string. ‘short string’ A single line of text, not more than 200 characters. ‘long string’ Multiple lines of plain text in reStructuredText format (see ‘http://docutils.sourceforge.net/’). ‘list of strings’ See below. Encoding the version information is an art in itself. Python packages generally adhere to the version format `major.minor[.patch][sub]'. The major number is 0 for initial, experimental releases of software. It is incremented for releases that represent major milestones in a package. The minor number is incremented when important new features are added to the package. The patch number increments when bug-fix releases are made. Additional trailing version information is sometimes used to indicate sub-releases. These are “a1,a2,…,aN” (for alpha releases, where functionality and API may change), “b1,b2,…,bN” (for beta releases, which only fix bugs) and “pr1,pr2,…,prN” (for final pre-release release testing). Some examples: 0.1.0 the first, experimental release of a package 1.0.1a2 the second alpha release of the first patch version of 1.0 ‘classifiers’ must be specified in a list: setup(..., classifiers=[ 'Development Status :: 4 - Beta', 'Environment :: Console', 'Environment :: Web Environment', 'Intended Audience :: End Users/Desktop', 'Intended Audience :: Developers', 'Intended Audience :: System Administrators', 'License :: OSI Approved :: Python Software Foundation License', 'Operating System :: MacOS :: MacOS X', 'Operating System :: Microsoft :: Windows', 'Operating System :: POSIX', 'Programming Language :: Python', 'Topic :: Communications :: Email', 'Topic :: Office/Business', 'Topic :: Software Development :: Bug Tracking', ], ) Changed in version 3.7: *note setup: 38b8. now warns when ‘classifiers’, ‘keywords’ or ‘platforms’ fields are not specified as a list or a string. ---------- Footnotes ---------- (1) https://pypi.org/classifiers  File: python.info, Node: Debugging the setup script, Prev: Additional meta-data, Up: Writing the Setup Script 17.2.9 Debugging the setup script --------------------------------- Sometimes things go wrong, and the setup script doesn’t do what the developer wants. Distutils catches any exceptions when running the setup script, and print a simple error message before the script is terminated. The motivation for this behaviour is to not confuse administrators who don’t know much about Python and are trying to install a package. If they get a big long traceback from deep inside the guts of Distutils, they may think the package or the Python installation is broken because they don’t read all the way down to the bottom and see that it’s a permission problem. On the other hand, this doesn’t help the developer to find the cause of the failure. For this purpose, the ‘DISTUTILS_DEBUG’ environment variable can be set to anything except an empty string, and distutils will now print detailed information about what it is doing, dump the full traceback when an exception occurs, and print the whole command line when an external program (like a C compiler) fails.  File: python.info, Node: Writing the Setup Configuration File, Next: Creating a Source Distribution, Prev: Writing the Setup Script, Up: Distributing Python Modules Legacy version 17.3 Writing the Setup Configuration File ========================================= Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. Often, it’s not possible to write down everything needed to build a distribution `a priori': you may need to get some information from the user, or from the user’s system, in order to proceed. As long as that information is fairly simple—a list of directories to search for C header files or libraries, for example—then providing a configuration file, ‘setup.cfg’, for users to edit is a cheap and easy way to solicit it. Configuration files also let you provide default values for any command option, which the installer can then override either on the command-line or by editing the config file. The setup configuration file is a useful middle-ground between the setup script—which, ideally, would be opaque to installers (1)—and the command-line to the setup script, which is outside of your control and entirely up to the installer. In fact, ‘setup.cfg’ (and any other Distutils configuration files present on the target system) are processed after the contents of the setup script, but before the command-line. This has several useful consequences: * installers can override some of what you put in ‘setup.py’ by editing ‘setup.cfg’ * you can provide non-standard defaults for options that are not easily set in ‘setup.py’ * installers can override anything in ‘setup.cfg’ using the command-line options to ‘setup.py’ The basic syntax of the configuration file is simple: [command] option=value ... where `command' is one of the Distutils commands (e.g. ‘build_py’, ‘install’), and `option' is one of the options that command supports. Any number of options can be supplied for each command, and any number of command sections can be included in the file. Blank lines are ignored, as are comments, which run from a ‘'#'’ character until the end of the line. Long option values can be split across multiple lines simply by indenting the continuation lines. You can find out the list of options supported by a particular command with the universal ‘--help’ option, e.g. $ python setup.py --help build_ext [...] Options for 'build_ext' command: --build-lib (-b) directory for compiled extension modules --build-temp (-t) directory for temporary files (build by-products) --inplace (-i) ignore build-lib and put compiled extensions into the source directory alongside your pure Python modules --include-dirs (-I) list of directories to search for header files --define (-D) C preprocessor macros to define --undef (-U) C preprocessor macros to undefine --swig-opts list of SWIG command line options [...] Note that an option spelled ‘--foo-bar’ on the command-line is spelled ‘foo_bar’ in configuration files. For example, say you want your extensions to be built “in-place”—that is, you have an extension ‘pkg.ext’, and you want the compiled extension file (‘ext.so’ on Unix, say) to be put in the same source directory as your pure Python modules ‘pkg.mod1’ and ‘pkg.mod2’. You can always use the ‘--inplace’ option on the command-line to ensure this: python setup.py build_ext --inplace But this requires that you always specify the ‘build_ext’ command explicitly, and remember to provide ‘--inplace’. An easier way is to “set and forget” this option, by encoding it in ‘setup.cfg’, the configuration file for this distribution: [build_ext] inplace=1 This will affect all builds of this module distribution, whether or not you explicitly specify ‘build_ext’. If you include ‘setup.cfg’ in your source distribution, it will also affect end-user builds—which is probably a bad idea for this option, since always building extensions in-place would break installation of the module distribution. In certain peculiar cases, though, modules are built right in their installation directory, so this is conceivably a useful ability. (Distributing extensions that expect to be built in their installation directory is almost always a bad idea, though.) Another example: certain commands take a lot of options that don’t change from run to run; for example, ‘bdist_rpm’ needs to know everything required to generate a “spec” file for creating an RPM distribution. Some of this information comes from the setup script, and some is automatically generated by the Distutils (such as the list of files installed). But some of it has to be supplied as options to ‘bdist_rpm’, which would be very tedious to do on the command-line for every run. Hence, here is a snippet from the Distutils’ own ‘setup.cfg’: [bdist_rpm] release = 1 packager = Greg Ward doc_files = CHANGES.txt README.txt USAGE.txt doc/ examples/ Note that the ‘doc_files’ option is simply a whitespace-separated string split across multiple lines for readability. See also ........ *note Syntax of config files: 40e1. in “Installing Python Modules” More information on the configuration files is available in the manual for system administrators. ---------- Footnotes ---------- (1) (1) This ideal probably won’t be achieved until auto-configuration is fully supported by the Distutils.  File: python.info, Node: Creating a Source Distribution, Next: Creating Built Distributions, Prev: Writing the Setup Configuration File, Up: Distributing Python Modules Legacy version 17.4 Creating a Source Distribution =================================== Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. As shown in section *note A Simple Example: 40be, you use the ‘sdist’ command to create a source distribution. In the simplest case, python setup.py sdist (assuming you haven’t specified any ‘sdist’ options in the setup script or config file), ‘sdist’ creates the archive of the default format for the current platform. The default format is a gzip’ed tar file (‘.tar.gz’) on Unix, and ZIP file on Windows. You can specify as many formats as you like using the ‘--formats’ option, for example: python setup.py sdist --formats=gztar,zip to create a gzipped tarball and a zip file. The available formats are: Format Description Notes ------------------------------------------------------------ ‘zip’ zip file (‘.zip’) (1),(3) ‘gztar’ gzip’ed tar file (2) (‘.tar.gz’) ‘bztar’ bzip2’ed tar file (‘.tar.bz2’) ‘xztar’ xz’ed tar file (‘.tar.xz’) ‘ztar’ compressed tar file (4) (‘.tar.Z’) ‘tar’ tar file (‘.tar’) Changed in version 3.5: Added support for the ‘xztar’ format. Notes: 1. default on Windows 2. default on Unix 3. requires either external ‘zip’ utility or *note zipfile: 142. module (part of the standard Python library since Python 1.6) 4. requires the ‘compress’ program. Notice that this format is now pending for deprecation and will be removed in the future versions of Python. When using any ‘tar’ format (‘gztar’, ‘bztar’, ‘xztar’, ‘ztar’ or ‘tar’), under Unix you can specify the ‘owner’ and ‘group’ names that will be set for each member of the archive. For example, if you want all files of the archive to be owned by root: python setup.py sdist --owner=root --group=root * Menu: * Specifying the files to distribute:: * Manifest-related options::  File: python.info, Node: Specifying the files to distribute, Next: Manifest-related options, Up: Creating a Source Distribution 17.4.1 Specifying the files to distribute ----------------------------------------- If you don’t supply an explicit list of files (or instructions on how to generate one), the ‘sdist’ command puts a minimal default set into the source distribution: * all Python source files implied by the ‘py_modules’ and ‘packages’ options * all C source files mentioned in the ‘ext_modules’ or ‘libraries’ options * scripts identified by the ‘scripts’ option See *note Installing Scripts: 40d4. * anything that looks like a test script: ‘test/test*.py’ (currently, the Distutils don’t do anything with test scripts except include them in source distributions, but in the future there will be a standard for testing Python module distributions) * Any of the standard README files (‘README’, ‘README.txt’, or ‘README.rst’), ‘setup.py’ (or whatever you called your setup script), and ‘setup.cfg’. * all files that matches the ‘package_data’ metadata. See *note Installing Package Data: 40d6. * all files that matches the ‘data_files’ metadata. See *note Installing Additional Files: 40d8. Sometimes this is enough, but usually you will want to specify additional files to distribute. The typical way to do this is to write a `manifest template', called ‘MANIFEST.in’ by default. The manifest template is just a list of instructions for how to generate your manifest file, ‘MANIFEST’, which is the exact list of files to include in your source distribution. The ‘sdist’ command processes this template and generates a manifest based on its instructions and what it finds in the filesystem. If you prefer to roll your own manifest file, the format is simple: one filename per line, regular files (or symlinks to them) only. If you do supply your own ‘MANIFEST’, you must specify everything: the default set of files described above does not apply in this case. Changed in version 3.1: An existing generated ‘MANIFEST’ will be regenerated without ‘sdist’ comparing its modification time to the one of ‘MANIFEST.in’ or ‘setup.py’. Changed in version 3.1.3: ‘MANIFEST’ files start with a comment indicating they are generated. Files without this comment are not overwritten or removed. Changed in version 3.2.2: ‘sdist’ will read a ‘MANIFEST’ file if no ‘MANIFEST.in’ exists, like it used to do. Changed in version 3.7: ‘README.rst’ is now included in the list of distutils standard READMEs. The manifest template has one command per line, where each command specifies a set of files to include or exclude from the source distribution. For an example, again we turn to the Distutils’ own manifest template: include *.txt recursive-include examples *.txt *.py prune examples/sample?/build The meanings should be fairly clear: include all files in the distribution root matching ‘*.txt’, all files anywhere under the ‘examples’ directory matching ‘*.txt’ or ‘*.py’, and exclude all directories matching ‘examples/sample?/build’. All of this is done `after' the standard include set, so you can exclude files from the standard set with explicit instructions in the manifest template. (Or, you can use the ‘--no-defaults’ option to disable the standard set entirely.) There are several other commands available in the manifest template mini-language; see section *note Creating a source distribution; the sdist command: 40e6. The order of commands in the manifest template matters: initially, we have the list of default files as described above, and each command in the template adds to or removes from that list of files. Once we have fully processed the manifest template, we remove files that should not be included in the source distribution: * all files in the Distutils “build” tree (default ‘build/’) * all files in directories named ‘RCS’, ‘CVS’, ‘.svn’, ‘.hg’, ‘.git’, ‘.bzr’ or ‘_darcs’ Now we have our complete list of files, which is written to the manifest for future reference, and then used to build the source distribution archive(s). You can disable the default set of included files with the ‘--no-defaults’ option, and you can disable the standard exclude set with ‘--no-prune’. Following the Distutils’ own manifest template, let’s trace how the ‘sdist’ command builds the list of files to include in the Distutils source distribution: 1. include all Python source files in the ‘distutils’ and ‘distutils/command’ subdirectories (because packages corresponding to those two directories were mentioned in the ‘packages’ option in the setup script—see section *note Writing the Setup Script: 40bf.) 2. include ‘README.txt’, ‘setup.py’, and ‘setup.cfg’ (standard files) 3. include ‘test/test*.py’ (standard files) 4. include ‘*.txt’ in the distribution root (this will find ‘README.txt’ a second time, but such redundancies are weeded out later) 5. include anything matching ‘*.txt’ or ‘*.py’ in the sub-tree under ‘examples’, 6. exclude all files in the sub-trees starting at directories matching ‘examples/sample?/build’—this may exclude files included by the previous two steps, so it’s important that the ‘prune’ command in the manifest template comes after the ‘recursive-include’ command 7. exclude the entire ‘build’ tree, and any ‘RCS’, ‘CVS’, ‘.svn’, ‘.hg’, ‘.git’, ‘.bzr’ and ‘_darcs’ directories Just like in the setup script, file and directory names in the manifest template should always be slash-separated; the Distutils will take care of converting them to the standard representation on your platform. That way, the manifest template is portable across operating systems.  File: python.info, Node: Manifest-related options, Prev: Specifying the files to distribute, Up: Creating a Source Distribution 17.4.2 Manifest-related options ------------------------------- The normal course of operations for the ‘sdist’ command is as follows: * if the manifest file (‘MANIFEST’ by default) exists and the first line does not have a comment indicating it is generated from ‘MANIFEST.in’, then it is used as is, unaltered * if the manifest file doesn’t exist or has been previously automatically generated, read ‘MANIFEST.in’ and create the manifest * if neither ‘MANIFEST’ nor ‘MANIFEST.in’ exist, create a manifest with just the default file set * use the list of files now in ‘MANIFEST’ (either just generated or read in) to create the source distribution archive(s) There are a couple of options that modify this behaviour. First, use the ‘--no-defaults’ and ‘--no-prune’ to disable the standard “include” and “exclude” sets. Second, you might just want to (re)generate the manifest, but not create a source distribution: python setup.py sdist --manifest-only ‘-o’ is a shortcut for ‘--manifest-only’.  File: python.info, Node: Creating Built Distributions, Next: Distutils Examples, Prev: Creating a Source Distribution, Up: Distributing Python Modules Legacy version 17.5 Creating Built Distributions ================================= Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. A “built distribution” is what you’re probably used to thinking of either as a “binary package” or an “installer” (depending on your background). It’s not necessarily binary, though, because it might contain only Python source code and/or byte-code; and we don’t call it a package, because that word is already spoken for in Python. (And “installer” is a term specific to the world of mainstream desktop systems.) A built distribution is how you make life as easy as possible for installers of your module distribution: for users of RPM-based Linux systems, it’s a binary RPM; for Windows users, it’s an executable installer; for Debian-based Linux users, it’s a Debian package; and so forth. Obviously, no one person will be able to create built distributions for every platform under the sun, so the Distutils are designed to enable module developers to concentrate on their specialty—writing code and creating source distributions—while an intermediary species called `packagers' springs up to turn source distributions into built distributions for as many platforms as there are packagers. Of course, the module developer could be their own packager; or the packager could be a volunteer “out there” somewhere who has access to a platform which the original developer does not; or it could be software periodically grabbing new source distributions and turning them into built distributions for as many platforms as the software has access to. Regardless of who they are, a packager uses the setup script and the ‘bdist’ command family to generate built distributions. As a simple example, if I run the following command in the Distutils source tree: python setup.py bdist then the Distutils builds my module distribution (the Distutils itself in this case), does a “fake” installation (also in the ‘build’ directory), and creates the default type of built distribution for my platform. The default format for built distributions is a “dumb” tar file on Unix, and a simple executable installer on Windows. (That tar file is considered “dumb” because it has to be unpacked in a specific location to work.) Thus, the above command on a Unix system creates ‘Distutils-1.0.`plat'.tar.gz’; unpacking this tarball from the right place installs the Distutils just as though you had downloaded the source distribution and run ‘python setup.py install’. (The “right place” is either the root of the filesystem or Python’s ‘`prefix'’ directory, depending on the options given to the ‘bdist_dumb’ command; the default is to make dumb distributions relative to ‘`prefix'’.) Obviously, for pure Python distributions, this isn’t any simpler than just running ‘python setup.py install’—but for non-pure distributions, which include extensions that would need to be compiled, it can mean the difference between someone being able to use your extensions or not. And creating “smart” built distributions, such as an RPM package or an executable installer for Windows, is far more convenient for users even if your distribution doesn’t include any extensions. The ‘bdist’ command has a ‘--formats’ option, similar to the ‘sdist’ command, which you can use to select the types of built distribution to generate: for example, python setup.py bdist --format=zip would, when run on a Unix system, create ‘Distutils-1.0.`plat'.zip’—again, this archive would be unpacked from the root directory to install the Distutils. The available formats for built distributions are: Format Description Notes ------------------------------------------------------------------- ‘gztar’ gzipped tar file (‘.tar.gz’) (1) ‘bztar’ bzipped tar file (‘.tar.bz2’) ‘xztar’ xzipped tar file (‘.tar.xz’) ‘ztar’ compressed tar file (‘.tar.Z’) (3) ‘tar’ tar file (‘.tar’) ‘zip’ zip file (‘.zip’) (2),(4) ‘rpm’ RPM (5) ‘pkgtool’ Solaris ‘pkgtool’ ‘sdux’ HP-UX ‘swinstall’ ‘wininst’ self-extracting ZIP file for (4) Windows ‘msi’ Microsoft Installer. Changed in version 3.5: Added support for the ‘xztar’ format. Notes: 1. default on Unix 2. default on Windows 3. requires external ‘compress’ utility. 4. requires either external ‘zip’ utility or *note zipfile: 142. module (part of the standard Python library since Python 1.6) 5. requires external ‘rpm’ utility, version 3.0.4 or better (use ‘rpm --version’ to find out which version you have) You don’t have to use the ‘bdist’ command with the ‘--formats’ option; you can also use the command that directly implements the format you’re interested in. Some of these ‘bdist’ “sub-commands” actually generate several similar formats; for instance, the ‘bdist_dumb’ command generates all the “dumb” archive formats (‘tar’, ‘gztar’, ‘bztar’, ‘xztar’, ‘ztar’, and ‘zip’), and ‘bdist_rpm’ generates both binary and source RPMs. The ‘bdist’ sub-commands, and the formats generated by each, are: Command Formats ------------------------------------------------------------------------- ‘bdist_dumb’ tar, gztar, bztar, xztar, ztar, zip ‘bdist_rpm’ rpm, srpm ‘bdist_wininst’ wininst ‘bdist_msi’ msi Note: bdist_wininst is deprecated since Python 3.8. The following sections give details on the individual ‘bdist_*’ commands. * Menu: * Creating RPM packages:: * Creating Windows Installers:: * Cross-compiling on Windows:: * Vista User Access Control (UAC): Vista User Access Control UAC.  File: python.info, Node: Creating RPM packages, Next: Creating Windows Installers, Up: Creating Built Distributions 17.5.1 Creating RPM packages ---------------------------- The RPM format is used by many popular Linux distributions, including Red Hat, SuSE, and Mandrake. If one of these (or any of the other RPM-based Linux distributions) is your usual environment, creating RPM packages for other users of that same distribution is trivial. Depending on the complexity of your module distribution and differences between Linux distributions, you may also be able to create RPMs that work on different RPM-based distributions. The usual way to create an RPM of your module distribution is to run the ‘bdist_rpm’ command: python setup.py bdist_rpm or the ‘bdist’ command with the ‘--format’ option: python setup.py bdist --formats=rpm The former allows you to specify RPM-specific options; the latter allows you to easily specify multiple formats in one run. If you need to do both, you can explicitly specify multiple ‘bdist_*’ commands and their options: python setup.py bdist_rpm --packager="John Doe " \ bdist_wininst --target-version="2.0" Creating RPM packages is driven by a ‘.spec’ file, much as using the Distutils is driven by the setup script. To make your life easier, the ‘bdist_rpm’ command normally creates a ‘.spec’ file based on the information you supply in the setup script, on the command line, and in any Distutils configuration files. Various options and sections in the ‘.spec’ file are derived from options in the setup script as follows: RPM ‘.spec’ file option or section Distutils setup script option -------------------------------------------------------------------------------------------------- Name ‘name’ Summary (in preamble) ‘description’ Version ‘version’ Vendor ‘author’ and ‘author_email’, or — & ‘maintainer’ and ‘maintainer_email’ Copyright ‘license’ Url ‘url’ %description (section) ‘long_description’ Additionally, there are many options in ‘.spec’ files that don’t have corresponding options in the setup script. Most of these are handled through options to the ‘bdist_rpm’ command as follows: RPM ‘.spec’ file option or ‘bdist_rpm’ option default value section ---------------------------------------------------------------------------------------------------- Release ‘release’ “1” Group ‘group’ “Development/Libraries” Vendor ‘vendor’ (see above) Packager ‘packager’ (none) Provides ‘provides’ (none) Requires ‘requires’ (none) Conflicts ‘conflicts’ (none) Obsoletes ‘obsoletes’ (none) Distribution ‘distribution_name’ (none) BuildRequires ‘build_requires’ (none) Icon ‘icon’ (none) Obviously, supplying even a few of these options on the command-line would be tedious and error-prone, so it’s usually best to put them in the setup configuration file, ‘setup.cfg’—see section *note Writing the Setup Configuration File: 40de. If you distribute or package many Python module distributions, you might want to put options that apply to all of them in your personal Distutils configuration file (‘~/.pydistutils.cfg’). If you want to temporarily disable this file, you can pass the ‘--no-user-cfg’ option to ‘setup.py’. There are three steps to building a binary RPM package, all of which are handled automatically by the Distutils: 1. create a ‘.spec’ file, which describes the package (analogous to the Distutils setup script; in fact, much of the information in the setup script winds up in the ‘.spec’ file) 2. create the source RPM 3. create the “binary” RPM (which may or may not contain binary code, depending on whether your module distribution contains Python extensions) Normally, RPM bundles the last two steps together; when you use the Distutils, all three steps are typically bundled together. If you wish, you can separate these three steps. You can use the ‘--spec-only’ option to make ‘bdist_rpm’ just create the ‘.spec’ file and exit; in this case, the ‘.spec’ file will be written to the “distribution directory”—normally ‘dist/’, but customizable with the ‘--dist-dir’ option. (Normally, the ‘.spec’ file winds up deep in the “build tree,” in a temporary directory created by ‘bdist_rpm’.)  File: python.info, Node: Creating Windows Installers, Next: Cross-compiling on Windows, Prev: Creating RPM packages, Up: Creating Built Distributions 17.5.2 Creating Windows Installers ---------------------------------- Warning: bdist_wininst is deprecated since Python 3.8. Executable installers are the natural format for binary distributions on Windows. They display a nice graphical user interface, display some information about the module distribution to be installed taken from the metadata in the setup script, let the user select a few options, and start or cancel the installation. Since the metadata is taken from the setup script, creating Windows installers is usually as easy as running: python setup.py bdist_wininst or the ‘bdist’ command with the ‘--formats’ option: python setup.py bdist --formats=wininst If you have a pure module distribution (only containing pure Python modules and packages), the resulting installer will be version independent and have a name like ‘foo-1.0.win32.exe’. Note that creating ‘wininst’ binary distributions in only supported on Windows systems. If you have a non-pure distribution, the extensions can only be created on a Windows platform, and will be Python version dependent. The installer filename will reflect this and now has the form ‘foo-1.0.win32-py2.0.exe’. You have to create a separate installer for every Python version you want to support. The installer will try to compile pure modules into *note bytecode: 614. after installation on the target system in normal and optimizing mode. If you don’t want this to happen for some reason, you can run the ‘bdist_wininst’ command with the ‘--no-target-compile’ and/or the ‘--no-target-optimize’ option. By default the installer will display the cool “Python Powered” logo when it is run, but you can also supply your own 152x261 bitmap which must be a Windows ‘.bmp’ file with the ‘--bitmap’ option. The installer will also display a large title on the desktop background window when it is run, which is constructed from the name of your distribution and the version number. This can be changed to another text by using the ‘--title’ option. The installer file will be written to the “distribution directory” — normally ‘dist/’, but customizable with the ‘--dist-dir’ option.  File: python.info, Node: Cross-compiling on Windows, Next: Vista User Access Control UAC, Prev: Creating Windows Installers, Up: Creating Built Distributions 17.5.3 Cross-compiling on Windows --------------------------------- Starting with Python 2.6, distutils is capable of cross-compiling between Windows platforms. In practice, this means that with the correct tools installed, you can use a 32bit version of Windows to create 64bit extensions and vice-versa. To build for an alternate platform, specify the ‘--plat-name’ option to the build command. Valid values are currently ‘win32’, and ‘win-amd64’. For example, on a 32bit version of Windows, you could execute: python setup.py build --plat-name=win-amd64 to build a 64bit version of your extension. The Windows Installers also support this option, so the command: python setup.py build --plat-name=win-amd64 bdist_wininst would create a 64bit installation executable on your 32bit version of Windows. To cross-compile, you must download the Python source code and cross-compile Python itself for the platform you are targeting - it is not possible from a binary installation of Python (as the .lib etc file for other platforms are not included.) In practice, this means the user of a 32 bit operating system will need to use Visual Studio 2008 to open the ‘PCbuild/PCbuild.sln’ solution in the Python source tree and build the “x64” configuration of the ‘pythoncore’ project before cross-compiling extensions is possible. Note that by default, Visual Studio 2008 does not install 64bit compilers or tools. You may need to reexecute the Visual Studio setup process and select these tools (using Control Panel->[Add/Remove] Programs is a convenient way to check or modify your existing install.) * Menu: * The Postinstallation script::  File: python.info, Node: The Postinstallation script, Up: Cross-compiling on Windows 17.5.3.1 The Postinstallation script .................................... Starting with Python 2.3, a postinstallation script can be specified with the ‘--install-script’ option. The basename of the script must be specified, and the script filename must also be listed in the scripts argument to the setup function. This script will be run at installation time on the target system after all the files have been copied, with ‘argv[1]’ set to ‘-install’, and again at uninstallation time before the files are removed with ‘argv[1]’ set to ‘-remove’. The installation script runs embedded in the windows installer, every output (‘sys.stdout’, ‘sys.stderr’) is redirected into a buffer and will be displayed in the GUI after the script has finished. Some functions especially useful in this context are available as additional built-in functions in the installation script. -- Function: directory_created (path) -- Function: file_created (path) These functions should be called when a directory or file is created by the postinstall script at installation time. It will register `path' with the uninstaller, so that it will be removed when the distribution is uninstalled. To be safe, directories are only removed if they are empty. -- Function: get_special_folder_path (csidl_string) This function can be used to retrieve special folder locations on Windows like the Start Menu or the Desktop. It returns the full path to the folder. `csidl_string' must be one of the following strings: "CSIDL_APPDATA" "CSIDL_COMMON_STARTMENU" "CSIDL_STARTMENU" "CSIDL_COMMON_DESKTOPDIRECTORY" "CSIDL_DESKTOPDIRECTORY" "CSIDL_COMMON_STARTUP" "CSIDL_STARTUP" "CSIDL_COMMON_PROGRAMS" "CSIDL_PROGRAMS" "CSIDL_FONTS" If the folder cannot be retrieved, *note OSError: 1d3. is raised. Which folders are available depends on the exact Windows version, and probably also the configuration. For details refer to Microsoft’s documentation of the ‘SHGetSpecialFolderPath()’ function. -- Function: create_shortcut (target, description, filename[, arguments[, workdir[, iconpath[, iconindex]]]]) This function creates a shortcut. `target' is the path to the program to be started by the shortcut. `description' is the description of the shortcut. `filename' is the title of the shortcut that the user will see. `arguments' specifies the command line arguments, if any. `workdir' is the working directory for the program. `iconpath' is the file containing the icon for the shortcut, and `iconindex' is the index of the icon in the file `iconpath'. Again, for details consult the Microsoft documentation for the ‘IShellLink’ interface.  File: python.info, Node: Vista User Access Control UAC, Prev: Cross-compiling on Windows, Up: Creating Built Distributions 17.5.4 Vista User Access Control (UAC) -------------------------------------- Starting with Python 2.6, bdist_wininst supports a ‘--user-access-control’ option. The default is ‘none’ (meaning no UAC handling is done), and other valid values are ‘auto’ (meaning prompt for UAC elevation if Python was installed for all users) and ‘force’ (meaning always prompt for elevation). Note: bdist_wininst is deprecated since Python 3.8.  File: python.info, Node: Distutils Examples, Next: Extending Distutils, Prev: Creating Built Distributions, Up: Distributing Python Modules Legacy version 17.6 Distutils Examples ======================= Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. This chapter provides a number of basic examples to help get started with distutils. Additional information about using distutils can be found in the Distutils Cookbook. See also ........ Distutils Cookbook(1) Collection of recipes showing how to achieve more control over distutils. * Menu: * Pure Python distribution (by module): Pure Python distribution by module. * Pure Python distribution (by package): Pure Python distribution by package. * Single extension module:: * Checking a package:: * Reading the metadata:: ---------- Footnotes ---------- (1) https://wiki.python.org/moin/Distutils/Cookbook  File: python.info, Node: Pure Python distribution by module, Next: Pure Python distribution by package, Up: Distutils Examples 17.6.1 Pure Python distribution (by module) ------------------------------------------- If you’re just distributing a couple of modules, especially if they don’t live in a particular package, you can specify them individually using the ‘py_modules’ option in the setup script. In the simplest case, you’ll have two files to worry about: a setup script and the single module you’re distributing, ‘foo.py’ in this example: / setup.py foo.py (In all diagrams in this section, `' will refer to the distribution root directory.) A minimal setup script to describe this situation would be: from distutils.core import setup setup(name='foo', version='1.0', py_modules=['foo'], ) Note that the name of the distribution is specified independently with the ‘name’ option, and there’s no rule that says it has to be the same as the name of the sole module in the distribution (although that’s probably a good convention to follow). However, the distribution name is used to generate filenames, so you should stick to letters, digits, underscores, and hyphens. Since ‘py_modules’ is a list, you can of course specify multiple modules, eg. if you’re distributing modules ‘foo’ and ‘bar’, your setup might look like this: / setup.py foo.py bar.py and the setup script might be from distutils.core import setup setup(name='foobar', version='1.0', py_modules=['foo', 'bar'], ) You can put module source files into another directory, but if you have enough modules to do that, it’s probably easier to specify modules by package rather than listing them individually.  File: python.info, Node: Pure Python distribution by package, Next: Single extension module, Prev: Pure Python distribution by module, Up: Distutils Examples 17.6.2 Pure Python distribution (by package) -------------------------------------------- If you have more than a couple of modules to distribute, especially if they are in multiple packages, it’s probably easier to specify whole packages rather than individual modules. This works even if your modules are not in a package; you can just tell the Distutils to process modules from the root package, and that works the same as any other package (except that you don’t have to have an ‘__init__.py’ file). The setup script from the last example could also be written as from distutils.core import setup setup(name='foobar', version='1.0', packages=[''], ) (The empty string stands for the root package.) If those two files are moved into a subdirectory, but remain in the root package, e.g.: / setup.py src/ foo.py bar.py then you would still specify the root package, but you have to tell the Distutils where source files in the root package live: from distutils.core import setup setup(name='foobar', version='1.0', package_dir={'': 'src'}, packages=[''], ) More typically, though, you will want to distribute multiple modules in the same package (or in sub-packages). For example, if the ‘foo’ and ‘bar’ modules belong in package ‘foobar’, one way to layout your source tree is / setup.py foobar/ __init__.py foo.py bar.py This is in fact the default layout expected by the Distutils, and the one that requires the least work to describe in your setup script: from distutils.core import setup setup(name='foobar', version='1.0', packages=['foobar'], ) If you want to put modules in directories not named for their package, then you need to use the ‘package_dir’ option again. For example, if the ‘src’ directory holds modules in the ‘foobar’ package: / setup.py src/ __init__.py foo.py bar.py an appropriate setup script would be from distutils.core import setup setup(name='foobar', version='1.0', package_dir={'foobar': 'src'}, packages=['foobar'], ) Or, you might put modules from your main package right in the distribution root: / setup.py __init__.py foo.py bar.py in which case your setup script would be from distutils.core import setup setup(name='foobar', version='1.0', package_dir={'foobar': ''}, packages=['foobar'], ) (The empty string also stands for the current directory.) If you have sub-packages, they must be explicitly listed in ‘packages’, but any entries in ‘package_dir’ automatically extend to sub-packages. (In other words, the Distutils does `not' scan your source tree, trying to figure out which directories correspond to Python packages by looking for ‘__init__.py’ files.) Thus, if the default layout grows a sub-package: / setup.py foobar/ __init__.py foo.py bar.py subfoo/ __init__.py blah.py then the corresponding setup script would be from distutils.core import setup setup(name='foobar', version='1.0', packages=['foobar', 'foobar.subfoo'], )  File: python.info, Node: Single extension module, Next: Checking a package, Prev: Pure Python distribution by package, Up: Distutils Examples 17.6.3 Single extension module ------------------------------ Extension modules are specified using the ‘ext_modules’ option. ‘package_dir’ has no effect on where extension source files are found; it only affects the source for pure Python modules. The simplest case, a single extension module in a single C source file, is: / setup.py foo.c If the ‘foo’ extension belongs in the root package, the setup script for this could be from distutils.core import setup from distutils.extension import Extension setup(name='foobar', version='1.0', ext_modules=[Extension('foo', ['foo.c'])], ) If the extension actually belongs in a package, say ‘foopkg’, then With exactly the same source tree layout, this extension can be put in the ‘foopkg’ package simply by changing the name of the extension: from distutils.core import setup from distutils.extension import Extension setup(name='foobar', version='1.0', ext_modules=[Extension('foopkg.foo', ['foo.c'])], )  File: python.info, Node: Checking a package, Next: Reading the metadata, Prev: Single extension module, Up: Distutils Examples 17.6.4 Checking a package ------------------------- The ‘check’ command allows you to verify if your package meta-data meet the minimum requirements to build a distribution. To run it, just call it using your ‘setup.py’ script. If something is missing, ‘check’ will display a warning. Let’s take an example with a simple script: from distutils.core import setup setup(name='foobar') Running the ‘check’ command will display some warnings: $ python setup.py check running check warning: check: missing required meta-data: version, url warning: check: missing meta-data: either (author and author_email) or (maintainer and maintainer_email) must be supplied If you use the reStructuredText syntax in the ‘long_description’ field and docutils(1) is installed you can check if the syntax is fine with the ‘check’ command, using the ‘restructuredtext’ option. For example, if the ‘setup.py’ script is changed like this: from distutils.core import setup desc = """\ My description ============== This is the description of the ``foobar`` package. """ setup(name='foobar', version='1', author='tarek', author_email='tarek@ziade.org', url='http://example.com', long_description=desc) Where the long description is broken, ‘check’ will be able to detect it by using the ‘docutils’ parser: $ python setup.py check --restructuredtext running check warning: check: Title underline too short. (line 2) warning: check: Could not finish the parsing. ---------- Footnotes ---------- (1) http://docutils.sourceforge.net  File: python.info, Node: Reading the metadata, Prev: Checking a package, Up: Distutils Examples 17.6.5 Reading the metadata --------------------------- The *note distutils.core.setup(): 38b8. function provides a command-line interface that allows you to query the metadata fields of a project through the ‘setup.py’ script of a given project: $ python setup.py --name distribute This call reads the ‘name’ metadata by running the *note distutils.core.setup(): 38b8. function. Although, when a source or binary distribution is created with Distutils, the metadata fields are written in a static file called ‘PKG-INFO’. When a Distutils-based project is installed in Python, the ‘PKG-INFO’ file is copied alongside the modules and packages of the distribution under ‘NAME-VERSION-pyX.X.egg-info’, where ‘NAME’ is the name of the project, ‘VERSION’ its version as defined in the Metadata, and ‘pyX.X’ the major and minor version of Python like ‘2.7’ or ‘3.2’. You can read back this static file, by using the ‘distutils.dist.DistributionMetadata’ class and its ‘read_pkg_file()’ method: >>> from distutils.dist import DistributionMetadata >>> metadata = DistributionMetadata() >>> metadata.read_pkg_file(open('distribute-0.6.8-py2.7.egg-info')) >>> metadata.name 'distribute' >>> metadata.version '0.6.8' >>> metadata.description 'Easily download, build, install, upgrade, and uninstall Python packages' Notice that the class can also be instantiated with a metadata file path to loads its values: >>> pkg_info_path = 'distribute-0.6.8-py2.7.egg-info' >>> DistributionMetadata(pkg_info_path).name 'distribute'  File: python.info, Node: Extending Distutils, Next: Command Reference, Prev: Distutils Examples, Up: Distributing Python Modules Legacy version 17.7 Extending Distutils ======================== Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. Distutils can be extended in various ways. Most extensions take the form of new commands or replacements for existing commands. New commands may be written to support new types of platform-specific packaging, for example, while replacements for existing commands may be made to modify details of how the command operates on a package. Most extensions of the distutils are made within ‘setup.py’ scripts that want to modify existing commands; many simply add a few file extensions that should be copied into packages in addition to ‘.py’ files as a convenience. Most distutils command implementations are subclasses of the *note distutils.cmd.Command: 4107. class. New commands may directly inherit from ‘Command’, while replacements often derive from ‘Command’ indirectly, directly subclassing the command they are replacing. Commands are required to derive from ‘Command’. * Menu: * Integrating new commands:: * Adding new distribution types::  File: python.info, Node: Integrating new commands, Next: Adding new distribution types, Up: Extending Distutils 17.7.1 Integrating new commands ------------------------------- There are different ways to integrate new command implementations into distutils. The most difficult is to lobby for the inclusion of the new features in distutils itself, and wait for (and require) a version of Python that provides that support. This is really hard for many reasons. The most common, and possibly the most reasonable for most needs, is to include the new implementations with your ‘setup.py’ script, and cause the *note distutils.core.setup(): 38b8. function use them: from distutils.command.build_py import build_py as _build_py from distutils.core import setup class build_py(_build_py): """Specialized Python source builder.""" # implement whatever needs to be different... setup(cmdclass={'build_py': build_py}, ...) This approach is most valuable if the new implementations must be used to use a particular package, as everyone interested in the package will need to have the new command implementation. Beginning with Python 2.4, a third option is available, intended to allow new commands to be added which can support existing ‘setup.py’ scripts without requiring modifications to the Python installation. This is expected to allow third-party extensions to provide support for additional packaging systems, but the commands can be used for anything distutils commands can be used for. A new configuration option, ‘command_packages’ (command-line option ‘--command-packages’), can be used to specify additional packages to be searched for modules implementing commands. Like all distutils options, this can be specified on the command line or in a configuration file. This option can only be set in the ‘[global]’ section of a configuration file, or before any commands on the command line. If set in a configuration file, it can be overridden from the command line; setting it to an empty string on the command line causes the default to be used. This should never be set in a configuration file provided with a package. This new option can be used to add any number of packages to the list of packages searched for command implementations; multiple package names should be separated by commas. When not specified, the search is only performed in the *note distutils.command: 3e. package. When ‘setup.py’ is run with the option ‘--command-packages distcmds,buildcmds’, however, the packages *note distutils.command: 3e, ‘distcmds’, and ‘buildcmds’ will be searched in that order. New commands are expected to be implemented in modules of the same name as the command by classes sharing the same name. Given the example command line option above, the command ‘bdist_openpkg’ could be implemented by the class ‘distcmds.bdist_openpkg.bdist_openpkg’ or ‘buildcmds.bdist_openpkg.bdist_openpkg’.  File: python.info, Node: Adding new distribution types, Prev: Integrating new commands, Up: Extending Distutils 17.7.2 Adding new distribution types ------------------------------------ Commands that create distributions (files in the ‘dist/’ directory) need to add ‘(command, filename)’ pairs to ‘self.distribution.dist_files’ so that ‘upload’ can upload it to PyPI. The `filename' in the pair contains no path information, only the name of the file itself. In dry-run mode, pairs should still be added to represent what would have been created.  File: python.info, Node: Command Reference, Next: API Reference, Prev: Extending Distutils, Up: Distributing Python Modules Legacy version 17.8 Command Reference ====================== Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. * Menu: * Installing modules; the install command family: Installing modules the install command family. * Creating a source distribution; the sdist command: Creating a source distribution the sdist command.  File: python.info, Node: Installing modules the install command family, Next: Creating a source distribution the sdist command, Up: Command Reference 17.8.1 Installing modules: the ‘install’ command family ------------------------------------------------------- The install command ensures that the build commands have been run and then runs the subcommands ‘install_lib’, ‘install_data’ and ‘install_scripts’. * Menu: * install_data:: * install_scripts::  File: python.info, Node: install_data, Next: install_scripts, Up: Installing modules the install command family 17.8.1.1 ‘install_data’ ....................... This command installs all data files provided with the distribution.  File: python.info, Node: install_scripts, Prev: install_data, Up: Installing modules the install command family 17.8.1.2 ‘install_scripts’ .......................... This command installs all (Python) scripts in the distribution.  File: python.info, Node: Creating a source distribution the sdist command, Prev: Installing modules the install command family, Up: Command Reference 17.8.2 Creating a source distribution: the ‘sdist’ command ---------------------------------------------------------- The manifest template commands are: Command Description ---------------------------------------------------------------------------------------------------- ‘include pat1 pat2 ...’ include all files matching any of the listed patterns ‘exclude pat1 pat2 ...’ exclude all files matching any of the listed patterns ‘recursive-include dir pat1 pat2 ...’ include all files under `dir' matching any of the listed patterns ‘recursive-exclude dir pat1 pat2 ...’ exclude all files under `dir' matching any of the listed patterns ‘global-include pat1 pat2 ...’ include all files anywhere in the source tree matching — & any of the listed patterns ‘global-exclude pat1 pat2 ...’ exclude all files anywhere in the source tree matching — & any of the listed patterns ‘prune dir’ exclude all files under `dir' ‘graft dir’ include all files under `dir' The patterns here are Unix-style “glob” patterns: ‘*’ matches any sequence of regular filename characters, ‘?’ matches any single regular filename character, and ‘[range]’ matches any of the characters in `range' (e.g., ‘a-z’, ‘a-zA-Z’, ‘a-f0-9_.’). The definition of “regular filename character” is platform-specific: on Unix it is anything except slash; on Windows anything except backslash or colon.  File: python.info, Node: API Reference, Prev: Command Reference, Up: Distributing Python Modules Legacy version 17.9 API Reference ================== See also ........ New and changed setup.py arguments in setuptools(1) The ‘setuptools’ project adds new capabilities to the ‘setup’ function and other APIs, makes the API consistent across different Python versions, and is hence recommended over using ‘distutils’ directly. Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. * Menu: * distutils.core — Core Distutils functionality: distutils core — Core Distutils functionality. * distutils.ccompiler — CCompiler base class: distutils ccompiler — CCompiler base class. * distutils.unixccompiler — Unix C Compiler: distutils unixccompiler — Unix C Compiler. * distutils.msvccompiler — Microsoft Compiler: distutils msvccompiler — Microsoft Compiler. * distutils.bcppcompiler — Borland Compiler: distutils bcppcompiler — Borland Compiler. * distutils.cygwincompiler — Cygwin Compiler: distutils cygwincompiler — Cygwin Compiler. * distutils.archive_util — Archiving utilities: distutils archive_util — Archiving utilities. * distutils.dep_util — Dependency checking: distutils dep_util — Dependency checking. * distutils.dir_util — Directory tree operations: distutils dir_util — Directory tree operations. * distutils.file_util — Single file operations: distutils file_util — Single file operations. * distutils.util — Miscellaneous other utility functions: distutils util — Miscellaneous other utility functions. * distutils.dist — The Distribution class: distutils dist — The Distribution class. * distutils.extension — The Extension class: distutils extension — The Extension class. * distutils.debug — Distutils debug mode: distutils debug — Distutils debug mode. * distutils.errors — Distutils exceptions: distutils errors — Distutils exceptions. * distutils.fancy_getopt — Wrapper around the standard getopt module: distutils fancy_getopt — Wrapper around the standard getopt module. * distutils.filelist — The FileList class: distutils filelist — The FileList class. * distutils.log — Simple PEP 282-style logging: distutils log — Simple PEP 282-style logging. * distutils.spawn — Spawn a sub-process: distutils spawn — Spawn a sub-process. * distutils.sysconfig — System configuration information: distutils sysconfig — System configuration information. * distutils.text_file — The TextFile class: distutils text_file — The TextFile class. * distutils.version — Version number classes: distutils version — Version number classes. * distutils.cmd — Abstract base class for Distutils commands: distutils cmd — Abstract base class for Distutils commands. * Creating a new Distutils command:: * distutils.command — Individual Distutils commands: distutils command — Individual Distutils commands. * distutils.command.bdist — Build a binary installer: distutils command bdist — Build a binary installer. * distutils.command.bdist_packager — Abstract base class for packagers: distutils command bdist_packager — Abstract base class for packagers. * distutils.command.bdist_dumb — Build a “dumb” installer: distutils command bdist_dumb — Build a “dumb” installer. * distutils.command.bdist_msi — Build a Microsoft Installer binary package: distutils command bdist_msi — Build a Microsoft Installer binary package. * distutils.command.bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM. * distutils.command.bdist_wininst — Build a Windows installer: distutils command bdist_wininst — Build a Windows installer. * distutils.command.sdist — Build a source distribution: distutils command sdist — Build a source distribution. * distutils.command.build — Build all files of a package: distutils command build — Build all files of a package. * distutils.command.build_clib — Build any C libraries in a package: distutils command build_clib — Build any C libraries in a package. * distutils.command.build_ext — Build any extensions in a package: distutils command build_ext — Build any extensions in a package. * distutils.command.build_py — Build the .py/.pyc files of a package: distutils command build_py — Build the py/ pyc files of a package. * distutils.command.build_scripts — Build the scripts of a package: distutils command build_scripts — Build the scripts of a package. * distutils.command.clean — Clean a package build area: distutils command clean — Clean a package build area. * distutils.command.config — Perform package configuration: distutils command config — Perform package configuration. * distutils.command.install — Install a package: distutils command install — Install a package. * distutils.command.install_data — Install data files from a package: distutils command install_data — Install data files from a package. * distutils.command.install_headers — Install C/C++ header files from a package: distutils command install_headers — Install C/C++ header files from a package. * distutils.command.install_lib — Install library files from a package: distutils command install_lib — Install library files from a package. * distutils.command.install_scripts — Install script files from a package: distutils command install_scripts — Install script files from a package. * distutils.command.register — Register a module with the Python Package Index: distutils command register — Register a module with the Python Package Index. * distutils.command.check — Check the meta-data of a package: distutils command check — Check the meta-data of a package. ---------- Footnotes ---------- (1) https://setuptools.readthedocs.io/en/latest/setuptools.html#new-and-changed-setup-keywords  File: python.info, Node: distutils core — Core Distutils functionality, Next: distutils ccompiler — CCompiler base class, Up: API Reference 17.9.1 ‘distutils.core’ — Core Distutils functionality ------------------------------------------------------ The *note distutils.core: 54. module is the only module that needs to be installed to use the Distutils. It provides the *note setup(): 38b8. (which is called from the setup script). Indirectly provides the ‘distutils.dist.Distribution’ and *note distutils.cmd.Command: 4107. class. -- Function: distutils.core.setup (arguments) The basic do-everything function that does most everything you could ever ask for from a Distutils method. The setup function takes a large number of arguments. These are laid out in the following table. argument name value type -------------------------------------------------------------------------------------------------------------------------------- `name' The name of the package a string `version' The version number of the package; a string see *note distutils.version: 66. `description' A single line describing the a string package `long_description' Longer description of the package a string `author' The name of the package author a string `author_email' The email address of the package a string author `maintainer' The name of the current a string maintainer, if different from the author. Note that if the maintainer is provided, distutils will use it as the author in ‘PKG-INFO’ `maintainer_email' The email address of the current a string maintainer, if different from the author `url' A URL for the package (homepage) a string `download_url' A URL to download the package a string `packages' A list of Python packages that a list of strings distutils will manipulate `py_modules' A list of Python modules that a list of strings distutils will manipulate `scripts' A list of standalone script files a list of strings to be built and installed `ext_modules' A list of Python extensions to be a list of instances of *note distutils.core.Extension: 40cd. built `classifiers' A list of categories for the a list of strings; valid classifiers are listed on PyPI(1). package `distclass' the *note Distribution: 4118. a subclass of *note distutils.core.Distribution: 4118. class to use `script_name' The name of the setup.py script - a string defaults to ‘sys.argv[0]’ `script_args' Arguments to supply to the setup a list of strings script `options' default options for the setup a dictionary script `license' The license for the package a string `keywords' Descriptive meta-data, see PEP a list of strings or a comma-separated string 314(2) `platforms' a list of strings or a comma-separated string `cmdclass' A mapping of command names to a dictionary *note Command: 4119. subclasses `data_files' A list of data files to install a list `package_dir' A mapping of package to directory a dictionary names -- Function: distutils.core.run_setup (script_name[, script_args=None, stop_after='run']) Run a setup script in a somewhat controlled environment, and return the ‘distutils.dist.Distribution’ instance that drives things. This is useful if you need to find out the distribution meta-data (passed as keyword args from `script' to *note setup(): 38b8.), or the contents of the config files or command-line. `script_name' is a file that will be read and run with *note exec(): c44. ‘sys.argv[0]’ will be replaced with `script' for the duration of the call. `script_args' is a list of strings; if supplied, ‘sys.argv[1:]’ will be replaced by `script_args' for the duration of the call. `stop_after' tells *note setup(): 38b8. when to stop processing; possible values: value description ---------------------------------------------------------------------- `init' Stop after the *note Distribution: 4118. instance has been created and populated with the keyword arguments to *note setup(): 38b8. `config' Stop after config files have been parsed (and their data stored in the *note Distribution: 4118. instance) `commandline' Stop after the command-line (‘sys.argv[1:]’ or `script_args') have been parsed (and the data stored in the *note Distribution: 4118. instance.) `run' Stop after all commands have been run (the same as if *note setup(): 38b8. had been called in the usual way). This is the default value. In addition, the *note distutils.core: 54. module exposed a number of classes that live elsewhere. * ‘Extension’ from *note distutils.extension: 5b. * *note Command: 4107. from *note distutils.cmd: 3d. * ‘Distribution’ from *note distutils.dist: 59. A short description of each of these follows, but see the relevant module for the full reference. -- Class: distutils.core.Extension The Extension class describes a single C or C++ extension module in a setup script. It accepts the following keyword arguments in its constructor: argument name value type -------------------------------------------------------------------------------------------------- `name' the full name of the extension, a string including any packages — ie. `not' a filename or pathname, but Python dotted name `sources' list of source filenames, relative a list of strings to the distribution root (where the setup script lives), in Unix form (slash-separated) for portability. Source files may be C, C++, SWIG (.i), platform-specific resource files, or whatever else is recognized by the ‘build_ext’ command as source for a Python extension. `include_dirs' list of directories to search for a list of strings C/C++ header files (in Unix form for portability) `define_macros' list of macros to define; each a list of tuples macro is defined using a 2-tuple ‘(name, value)’, where `value' is either the string to define it to or ‘None’ to define it without a particular value (equivalent of ‘#define FOO’ in source or ‘-DFOO’ on Unix C compiler command line) `undef_macros' list of macros to undefine a list of strings explicitly `library_dirs' list of directories to search for a list of strings C/C++ libraries at link time `libraries' list of library names (not a list of strings filenames or paths) to link against `runtime_library_dirs' list of directories to search for a list of strings C/C++ libraries at run time (for shared extensions, this is when the extension is loaded) `extra_objects' list of extra files to link with a list of strings (eg. object files not implied by ‘sources’, static library that must be explicitly specified, binary resource files, etc.) `extra_compile_args' any extra platform- and a list of strings compiler-specific information to use when compiling the source files in ‘sources’. For platforms and compilers where a command line makes sense, this is typically a list of command-line arguments, but for other platforms it could be anything. `extra_link_args' any extra platform- and a list of strings compiler-specific information to use when linking object files together to create the extension (or to create a new static Python interpreter). Similar interpretation as for ‘extra_compile_args’. `export_symbols' list of symbols to be exported a list of strings from a shared extension. Not used on all platforms, and not generally necessary for Python extensions, which typically export exactly one symbol: ‘init’ + extension_name. `depends' list of files that the extension a list of strings depends on `language' extension language (i.e. ‘'c'’, a string ‘'c++'’, ‘'objc'’). Will be detected from the source extensions if not provided. `optional' specifies that a build failure in a boolean the extension should not abort the build process, but simply skip the extension. Changed in version 3.8: On Unix, C extensions are no longer linked to libpython except on Android and Cygwin. -- Class: distutils.core.Distribution A *note Distribution: 4118. describes how to build, install and package up a Python software package. See the *note setup(): 38b8. function for a list of keyword arguments accepted by the Distribution constructor. *note setup(): 38b8. creates a Distribution instance. Changed in version 3.7: *note Distribution: 4118. now warns if ‘classifiers’, ‘keywords’ and ‘platforms’ fields are not specified as a list or a string. -- Class: distutils.core.Command A *note Command: 4119. class (or rather, an instance of one of its subclasses) implement a single distutils command. ---------- Footnotes ---------- (1) https://pypi.org/classifiers (2) https://www.python.org/dev/peps/pep-0314  File: python.info, Node: distutils ccompiler — CCompiler base class, Next: distutils unixccompiler — Unix C Compiler, Prev: distutils core — Core Distutils functionality, Up: API Reference 17.9.2 ‘distutils.ccompiler’ — CCompiler base class --------------------------------------------------- This module provides the abstract base class for the *note CCompiler: 411c. classes. A *note CCompiler: 411c. instance can be used for all the compile and link steps needed to build a single project. Methods are provided to set options for the compiler — macro definitions, include directories, link path, libraries and the like. This module provides the following functions. -- Function: distutils.ccompiler.gen_lib_options (compiler, library_dirs, runtime_library_dirs, libraries) Generate linker options for searching library directories and linking with specific libraries. `libraries' and `library_dirs' are, respectively, lists of library names (not filenames!) and search directories. Returns a list of command-line options suitable for use with some compiler (depending on the two format strings passed in). -- Function: distutils.ccompiler.gen_preprocess_options (macros, include_dirs) Generate C pre-processor options (‘-D’, ‘-U’, ‘-I’) as used by at least two types of compilers: the typical Unix compiler and Visual C++. `macros' is the usual thing, a list of 1- or 2-tuples, where ‘(name,)’ means undefine (‘-U’) macro `name', and ‘(name, value)’ means define (‘-D’) macro `name' to `value'. `include_dirs' is just a list of directory names to be added to the header file search path (‘-I’). Returns a list of command-line options suitable for either Unix compilers or Visual C++. -- Function: distutils.ccompiler.get_default_compiler (osname, platform) Determine the default compiler to use for the given platform. `osname' should be one of the standard Python OS names (i.e. the ones returned by ‘os.name’) and `platform' the common value returned by ‘sys.platform’ for the platform in question. The default values are ‘os.name’ and ‘sys.platform’ in case the parameters are not given. -- Function: distutils.ccompiler.new_compiler (plat=None, compiler=None, verbose=0, dry_run=0, force=0) Factory function to generate an instance of some CCompiler subclass for the supplied platform/compiler combination. `plat' defaults to ‘os.name’ (eg. ‘'posix'’, ‘'nt'’), and `compiler' defaults to the default compiler for that platform. Currently only ‘'posix'’ and ‘'nt'’ are supported, and the default compilers are “traditional Unix interface” (‘UnixCCompiler’ class) and Visual C++ (‘MSVCCompiler’ class). Note that it’s perfectly possible to ask for a Unix compiler object under Windows, and a Microsoft compiler object under Unix—if you supply a value for `compiler', `plat' is ignored. -- Function: distutils.ccompiler.show_compilers () Print list of available compilers (used by the ‘--help-compiler’ options to ‘build’, ‘build_ext’, ‘build_clib’). -- Class: distutils.ccompiler.CCompiler ([verbose=0, dry_run=0, force=0]) The abstract base class *note CCompiler: 411c. defines the interface that must be implemented by real compiler classes. The class also has some utility methods used by several compiler classes. The basic idea behind a compiler abstraction class is that each instance can be used for all the compile/link steps in building a single project. Thus, attributes common to all of those compile and link steps — include directories, macros to define, libraries to link against, etc. — are attributes of the compiler instance. To allow for variability in how individual files are treated, most of those attributes may be varied on a per-compilation or per-link basis. The constructor for each subclass creates an instance of the Compiler object. Flags are `verbose' (show verbose output), `dry_run' (don’t actually execute the steps) and `force' (rebuild everything, regardless of dependencies). All of these flags default to ‘0’ (off). Note that you probably don’t want to instantiate *note CCompiler: 411c. or one of its subclasses directly - use the ‘distutils.CCompiler.new_compiler()’ factory function instead. The following methods allow you to manually alter compiler options for the instance of the Compiler class. -- Method: add_include_dir (dir) Add `dir' to the list of directories that will be searched for header files. The compiler is instructed to search directories in the order in which they are supplied by successive calls to *note add_include_dir(): 4122. -- Method: set_include_dirs (dirs) Set the list of directories that will be searched to `dirs' (a list of strings). Overrides any preceding calls to *note add_include_dir(): 4122.; subsequent calls to *note add_include_dir(): 4122. add to the list passed to *note set_include_dirs(): 4123. This does not affect any list of standard include directories that the compiler may search by default. -- Method: add_library (libname) Add `libname' to the list of libraries that will be included in all links driven by this compiler object. Note that `libname' should *not* be the name of a file containing a library, but the name of the library itself: the actual filename will be inferred by the linker, the compiler, or the compiler class (depending on the platform). The linker will be instructed to link against libraries in the order they were supplied to *note add_library(): 4124. and/or *note set_libraries(): 4125. It is perfectly valid to duplicate library names; the linker will be instructed to link against libraries as many times as they are mentioned. -- Method: set_libraries (libnames) Set the list of libraries to be included in all links driven by this compiler object to `libnames' (a list of strings). This does not affect any standard system libraries that the linker may include by default. -- Method: add_library_dir (dir) Add `dir' to the list of directories that will be searched for libraries specified to *note add_library(): 4124. and *note set_libraries(): 4125. The linker will be instructed to search for libraries in the order they are supplied to *note add_library_dir(): 4126. and/or *note set_library_dirs(): 4127. -- Method: set_library_dirs (dirs) Set the list of library search directories to `dirs' (a list of strings). This does not affect any standard library search path that the linker may search by default. -- Method: add_runtime_library_dir (dir) Add `dir' to the list of directories that will be searched for shared libraries at runtime. -- Method: set_runtime_library_dirs (dirs) Set the list of directories to search for shared libraries at runtime to `dirs' (a list of strings). This does not affect any standard search path that the runtime linker may search by default. -- Method: define_macro (name[, value=None]) Define a preprocessor macro for all compilations driven by this compiler object. The optional parameter `value' should be a string; if it is not supplied, then the macro will be defined without an explicit value and the exact outcome depends on the compiler used. -- Method: undefine_macro (name) Undefine a preprocessor macro for all compilations driven by this compiler object. If the same macro is defined by *note define_macro(): 412a. and undefined by *note undefine_macro(): 412b. the last call takes precedence (including multiple redefinitions or undefinitions). If the macro is redefined/undefined on a per-compilation basis (ie. in the call to *note compile(): 1b4.), then that takes precedence. -- Method: add_link_object (object) Add `object' to the list of object files (or analogues, such as explicitly named library files or the output of “resource compilers”) to be included in every link driven by this compiler object. -- Method: set_link_objects (objects) Set the list of object files (or analogues) to be included in every link to `objects'. This does not affect any standard object files that the linker may include by default (such as system libraries). The following methods implement methods for autodetection of compiler options, providing some functionality similar to GNU ‘autoconf’. -- Method: detect_language (sources) Detect the language of a given file, or list of files. Uses the instance attributes ‘language_map’ (a dictionary), and ‘language_order’ (a list) to do the job. -- Method: find_library_file (dirs, lib[, debug=0]) Search the specified list of directories for a static or shared library file `lib' and return the full path to that file. If `debug' is true, look for a debugging version (if that makes sense on the current platform). Return ‘None’ if `lib' wasn’t found in any of the specified directories. -- Method: has_function (funcname[, includes=None, include_dirs=None, libraries=None, library_dirs=None]) Return a boolean indicating whether `funcname' is supported on the current platform. The optional arguments can be used to augment the compilation environment by providing additional include files and paths and libraries and paths. -- Method: library_dir_option (dir) Return the compiler option to add `dir' to the list of directories searched for libraries. -- Method: library_option (lib) Return the compiler option to add `lib' to the list of libraries linked into the shared library or executable. -- Method: runtime_library_dir_option (dir) Return the compiler option to add `dir' to the list of directories searched for runtime libraries. -- Method: set_executables (**args) Define the executables (and options for them) that will be run to perform the various stages of compilation. The exact set of executables that may be specified here depends on the compiler class (via the ‘executables’ class attribute), but most will have: attribute description ------------------------------------------------------------------ `compiler' the C/C++ compiler `linker_so' linker used to create shared objects and libraries `linker_exe' linker used to create binary executables `archiver' static library creator On platforms with a command-line (Unix, DOS/Windows), each of these is a string that will be split into executable name and (optional) list of arguments. (Splitting the string is done similarly to how Unix shells operate: words are delimited by spaces, but quotes and backslashes can override this. See *note distutils.util.split_quoted(): 4135.) The following methods invoke stages in the build process. -- Method: compile (sources[, output_dir=None, macros=None, include_dirs=None, debug=0, extra_preargs=None, extra_postargs=None, depends=None]) Compile one or more source files. Generates object files (e.g. transforms a ‘.c’ file to a ‘.o’ file.) `sources' must be a list of filenames, most likely C/C++ files, but in reality anything that can be handled by a particular compiler and compiler class (eg. ‘MSVCCompiler’ can handle resource files in `sources'). Return a list of object filenames, one per source filename in `sources'. Depending on the implementation, not all source files will necessarily be compiled, but all corresponding object filenames will be returned. If `output_dir' is given, object files will be put under it, while retaining their original path component. That is, ‘foo/bar.c’ normally compiles to ‘foo/bar.o’ (for a Unix implementation); if `output_dir' is `build', then it would compile to ‘build/foo/bar.o’. `macros', if given, must be a list of macro definitions. A macro definition is either a ‘(name, value)’ 2-tuple or a ‘(name,)’ 1-tuple. The former defines a macro; if the value is ‘None’, the macro is defined without an explicit value. The 1-tuple case undefines a macro. Later definitions/redefinitions/undefinitions take precedence. `include_dirs', if given, must be a list of strings, the directories to add to the default include file search path for this compilation only. `debug' is a boolean; if true, the compiler will be instructed to output debug symbols in (or alongside) the object file(s). `extra_preargs' and `extra_postargs' are implementation-dependent. On platforms that have the notion of a command-line (e.g. Unix, DOS/Windows), they are most likely lists of strings: extra command-line arguments to prepend/append to the compiler command line. On other platforms, consult the implementation class documentation. In any event, they are intended as an escape hatch for those occasions when the abstract compiler framework doesn’t cut the mustard. `depends', if given, is a list of filenames that all targets depend on. If a source file is older than any file in depends, then the source file will be recompiled. This supports dependency tracking, but only at a coarse granularity. Raises ‘CompileError’ on failure. -- Method: create_static_lib (objects, output_libname[, output_dir=None, debug=0, target_lang=None]) Link a bunch of stuff together to create a static library file. The “bunch of stuff” consists of the list of object files supplied as `objects', the extra object files supplied to *note add_link_object(): 412c. and/or *note set_link_objects(): 412d, the libraries supplied to *note add_library(): 4124. and/or *note set_libraries(): 4125, and the libraries supplied as `libraries' (if any). `output_libname' should be a library name, not a filename; the filename will be inferred from the library name. `output_dir' is the directory where the library file will be put. `debug' is a boolean; if true, debugging information will be included in the library (note that on most platforms, it is the compile step where this matters: the `debug' flag is included here just for consistency). `target_lang' is the target language for which the given objects are being compiled. This allows specific linkage time treatment of certain languages. Raises ‘LibError’ on failure. -- Method: link (target_desc, objects, output_filename[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) Link a bunch of stuff together to create an executable or shared library file. The “bunch of stuff” consists of the list of object files supplied as `objects'. `output_filename' should be a filename. If `output_dir' is supplied, `output_filename' is relative to it (i.e. `output_filename' can provide directory components if needed). `libraries' is a list of libraries to link against. These are library names, not filenames, since they’re translated into filenames in a platform-specific way (eg. `foo' becomes ‘libfoo.a’ on Unix and ‘foo.lib’ on DOS/Windows). However, they can include a directory component, which means the linker will look in that specific directory rather than searching all the normal locations. `library_dirs', if supplied, should be a list of directories to search for libraries that were specified as bare library names (ie. no directory component). These are on top of the system default and those supplied to *note add_library_dir(): 4126. and/or *note set_library_dirs(): 4127. `runtime_library_dirs' is a list of directories that will be embedded into the shared library and used to search for other shared libraries that *it* depends on at run-time. (This may only be relevant on Unix.) `export_symbols' is a list of symbols that the shared library will export. (This appears to be relevant only on Windows.) `debug' is as for *note compile(): 1b4. and *note create_static_lib(): 4137, with the slight distinction that it actually matters on most platforms (as opposed to *note create_static_lib(): 4137, which includes a `debug' flag mostly for form’s sake). `extra_preargs' and `extra_postargs' are as for *note compile(): 1b4. (except of course that they supply command-line arguments for the particular linker being used). `target_lang' is the target language for which the given objects are being compiled. This allows specific linkage time treatment of certain languages. Raises ‘LinkError’ on failure. -- Method: link_executable (objects, output_progname[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, debug=0, extra_preargs=None, extra_postargs=None, target_lang=None]) Link an executable. `output_progname' is the name of the file executable, while `objects' are a list of object filenames to link in. Other arguments are as for the *note link(): 4138. method. -- Method: link_shared_lib (objects, output_libname[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) Link a shared library. `output_libname' is the name of the output library, while `objects' is a list of object filenames to link in. Other arguments are as for the *note link(): 4138. method. -- Method: link_shared_object (objects, output_filename[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) Link a shared object. `output_filename' is the name of the shared object that will be created, while `objects' is a list of object filenames to link in. Other arguments are as for the *note link(): 4138. method. -- Method: preprocess (source[, output_file=None, macros=None, include_dirs=None, extra_preargs=None, extra_postargs=None]) Preprocess a single C/C++ source file, named in `source'. Output will be written to file named `output_file', or `stdout' if `output_file' not supplied. `macros' is a list of macro definitions as for *note compile(): 1b4, which will augment the macros set with *note define_macro(): 412a. and *note undefine_macro(): 412b. `include_dirs' is a list of directory names that will be added to the default list, in the same way as *note add_include_dir(): 4122. Raises ‘PreprocessError’ on failure. The following utility methods are defined by the *note CCompiler: 411c. class, for use by the various concrete subclasses. -- Method: executable_filename (basename[, strip_dir=0, output_dir='']) Returns the filename of the executable for the given `basename'. Typically for non-Windows platforms this is the same as the basename, while Windows will get a ‘.exe’ added. -- Method: library_filename (libname[, lib_type='static', strip_dir=0, output_dir='']) Returns the filename for the given library name on the current platform. On Unix a library with `lib_type' of ‘'static'’ will typically be of the form ‘liblibname.a’, while a `lib_type' of ‘'dynamic'’ will be of the form ‘liblibname.so’. -- Method: object_filenames (source_filenames[, strip_dir=0, output_dir='']) Returns the name of the object files for the given source files. `source_filenames' should be a list of filenames. -- Method: shared_object_filename (basename[, strip_dir=0, output_dir='']) Returns the name of a shared object file for the given file name `basename'. -- Method: execute (func, args[, msg=None, level=1]) Invokes *note distutils.util.execute(): 4142. This method invokes a Python function `func' with the given arguments `args', after logging and taking into account the `dry_run' flag. -- Method: spawn (cmd) Invokes ‘distutils.util.spawn()’. This invokes an external process to run the given command. -- Method: mkpath (name[, mode=511]) Invokes *note distutils.dir_util.mkpath(): 4145. This creates a directory and any missing ancestor directories. -- Method: move_file (src, dst) Invokes *note distutils.file_util.move_file(): 4147. Renames `src' to `dst'. -- Method: announce (msg[, level=1]) Write a message using ‘distutils.log.debug()’. -- Method: warn (msg) Write a warning message `msg' to standard error. -- Method: debug_print (msg) If the `debug' flag is set on this *note CCompiler: 411c. instance, print `msg' to standard output, otherwise do nothing.  File: python.info, Node: distutils unixccompiler — Unix C Compiler, Next: distutils msvccompiler — Microsoft Compiler, Prev: distutils ccompiler — CCompiler base class, Up: API Reference 17.9.3 ‘distutils.unixccompiler’ — Unix C Compiler -------------------------------------------------- This module provides the ‘UnixCCompiler’ class, a subclass of ‘CCompiler’ that handles the typical Unix-style command-line C compiler: * macros defined with ‘-Dname[=value]’ * macros undefined with ‘-Uname’ * include search directories specified with ‘-Idir’ * libraries specified with ‘-llib’ * library search directories specified with ‘-Ldir’ * compile handled by ‘cc’ (or similar) executable with ‘-c’ option: compiles ‘.c’ to ‘.o’ * link static library handled by ‘ar’ command (possibly with ‘ranlib’) * link shared library handled by ‘cc’ ‘-shared’  File: python.info, Node: distutils msvccompiler — Microsoft Compiler, Next: distutils bcppcompiler — Borland Compiler, Prev: distutils unixccompiler — Unix C Compiler, Up: API Reference 17.9.4 ‘distutils.msvccompiler’ — Microsoft Compiler ---------------------------------------------------- This module provides ‘MSVCCompiler’, an implementation of the abstract ‘CCompiler’ class for Microsoft Visual Studio. Typically, extension modules need to be compiled with the same compiler that was used to compile Python. For Python 2.3 and earlier, the compiler was Visual Studio 6. For Python 2.4 and 2.5, the compiler is Visual Studio .NET 2003. ‘MSVCCompiler’ will normally choose the right compiler, linker etc. on its own. To override this choice, the environment variables `DISTUTILS_USE_SDK' and `MSSdk' must be both set. `MSSdk' indicates that the current environment has been setup by the SDK’s ‘SetEnv.Cmd’ script, or that the environment variables had been registered when the SDK was installed; `DISTUTILS_USE_SDK' indicates that the distutils user has made an explicit choice to override the compiler selection by ‘MSVCCompiler’.  File: python.info, Node: distutils bcppcompiler — Borland Compiler, Next: distutils cygwincompiler — Cygwin Compiler, Prev: distutils msvccompiler — Microsoft Compiler, Up: API Reference 17.9.5 ‘distutils.bcppcompiler’ — Borland Compiler -------------------------------------------------- This module provides ‘BorlandCCompiler’, a subclass of the abstract ‘CCompiler’ class for the Borland C++ compiler.  File: python.info, Node: distutils cygwincompiler — Cygwin Compiler, Next: distutils archive_util — Archiving utilities, Prev: distutils bcppcompiler — Borland Compiler, Up: API Reference 17.9.6 ‘distutils.cygwincompiler’ — Cygwin Compiler --------------------------------------------------- This module provides the ‘CygwinCCompiler’ class, a subclass of ‘UnixCCompiler’ that handles the Cygwin port of the GNU C compiler to Windows. It also contains the Mingw32CCompiler class which handles the mingw32 port of GCC (same as cygwin in no-cygwin mode).  File: python.info, Node: distutils archive_util — Archiving utilities, Next: distutils dep_util — Dependency checking, Prev: distutils cygwincompiler — Cygwin Compiler, Up: API Reference 17.9.7 ‘distutils.archive_util’ — Archiving utilities ----------------------------------------------------- This module provides a few functions for creating archive files, such as tarballs or zipfiles. -- Function: distutils.archive_util.make_archive (base_name, format[, root_dir=None, base_dir=None, verbose=0, dry_run=0]) Create an archive file (eg. ‘zip’ or ‘tar’). `base_name' is the name of the file to create, minus any format-specific extension; `format' is the archive format: one of ‘zip’, ‘tar’, ‘gztar’, ‘bztar’, ‘xztar’, or ‘ztar’. `root_dir' is a directory that will be the root directory of the archive; ie. we typically ‘chdir’ into `root_dir' before creating the archive. `base_dir' is the directory where we start archiving from; ie. `base_dir' will be the common prefix of all files and directories in the archive. `root_dir' and `base_dir' both default to the current directory. Returns the name of the archive file. Changed in version 3.5: Added support for the ‘xztar’ format. -- Function: distutils.archive_util.make_tarball (base_name, base_dir[, compress='gzip', verbose=0, dry_run=0]) ‘Create an (optional compressed) archive as a tar file from all files in and under `base_dir'. `compress' must be ‘'gzip'’ (the default), ‘'bzip2'’, ‘'xz'’, ‘'compress'’, or ‘None’. For the ‘'compress'’ method the compression utility named by ‘compress’ must be on the default program search path, so this is probably Unix-specific. The output tar file will be named ‘base_dir.tar’, possibly plus the appropriate compression extension (‘.gz’, ‘.bz2’, ‘.xz’ or ‘.Z’). Return the output filename. Changed in version 3.5: Added support for the ‘xz’ compression. -- Function: distutils.archive_util.make_zipfile (base_name, base_dir[, verbose=0, dry_run=0]) Create a zip file from all files in and under `base_dir'. The output zip file will be named `base_name' + ‘.zip’. Uses either the *note zipfile: 142. Python module (if available) or the InfoZIP ‘zip’ utility (if installed and found on the default search path). If neither tool is available, raises ‘DistutilsExecError’. Returns the name of the output zip file.  File: python.info, Node: distutils dep_util — Dependency checking, Next: distutils dir_util — Directory tree operations, Prev: distutils archive_util — Archiving utilities, Up: API Reference 17.9.8 ‘distutils.dep_util’ — Dependency checking ------------------------------------------------- This module provides functions for performing simple, timestamp-based dependency of files and groups of files; also, functions based entirely on such timestamp dependency analysis. -- Function: distutils.dep_util.newer (source, target) Return true if `source' exists and is more recently modified than `target', or if `source' exists and `target' doesn’t. Return false if both exist and `target' is the same age or newer than `source'. Raise ‘DistutilsFileError’ if `source' does not exist. -- Function: distutils.dep_util.newer_pairwise (sources, targets) Walk two filename lists in parallel, testing if each source is newer than its corresponding target. Return a pair of lists (`sources', `targets') where source is newer than target, according to the semantics of *note newer(): 4154. -- Function: distutils.dep_util.newer_group (sources, target[, missing='error']) Return true if `target' is out-of-date with respect to any file listed in `sources'. In other words, if `target' exists and is newer than every file in `sources', return false; otherwise return true. `missing' controls what we do when a source file is missing; the default (‘'error'’) is to blow up with an *note OSError: 1d3. from inside *note os.stat(): 1f1.; if it is ‘'ignore'’, we silently drop any missing source files; if it is ‘'newer'’, any missing source files make us assume that `target' is out-of-date (this is handy in “dry-run” mode: it’ll make you pretend to carry out commands that wouldn’t work because inputs are missing, but that doesn’t matter because you’re not actually going to run the commands).  File: python.info, Node: distutils dir_util — Directory tree operations, Next: distutils file_util — Single file operations, Prev: distutils dep_util — Dependency checking, Up: API Reference 17.9.9 ‘distutils.dir_util’ — Directory tree operations ------------------------------------------------------- This module provides functions for operating on directories and trees of directories. -- Function: distutils.dir_util.mkpath (name[, mode=0o777, verbose=0, dry_run=0]) Create a directory and any missing ancestor directories. If the directory already exists (or if `name' is the empty string, which means the current directory, which of course exists), then do nothing. Raise ‘DistutilsFileError’ if unable to create some directory along the way (eg. some sub-path exists, but is a file rather than a directory). If `verbose' is true, print a one-line summary of each mkdir to stdout. Return the list of directories actually created. -- Function: distutils.dir_util.create_tree (base_dir, files[, mode=0o777, verbose=0, dry_run=0]) Create all the empty directories under `base_dir' needed to put `files' there. `base_dir' is just the name of a directory which doesn’t necessarily exist yet; `files' is a list of filenames to be interpreted relative to `base_dir'. `base_dir' + the directory portion of every file in `files' will be created if it doesn’t already exist. `mode', `verbose' and `dry_run' flags are as for *note mkpath(): 4145. -- Function: distutils.dir_util.copy_tree (src, dst[, preserve_mode=1, preserve_times=1, preserve_symlinks=0, update=0, verbose=0, dry_run=0]) Copy an entire directory tree `src' to a new location `dst'. Both `src' and `dst' must be directory names. If `src' is not a directory, raise ‘DistutilsFileError’. If `dst' does not exist, it is created with *note mkpath(): 4145. The end result of the copy is that every file in `src' is copied to `dst', and directories under `src' are recursively copied to `dst'. Return the list of files that were copied or might have been copied, using their output name. The return value is unaffected by `update' or `dry_run': it is simply the list of all files under `src', with the names changed to be under `dst'. `preserve_mode' and `preserve_times' are the same as for *note distutils.file_util.copy_file(): 415a.; note that they only apply to regular files, not to directories. If `preserve_symlinks' is true, symlinks will be copied as symlinks (on platforms that support them!); otherwise (the default), the destination of the symlink will be copied. `update' and `verbose' are the same as for ‘copy_file()’. Files in `src' that begin with ‘.nfs’ are skipped (more information on these files is available in answer D2 of the NFS FAQ page(1)). Changed in version 3.3.1: NFS files are ignored. -- Function: distutils.dir_util.remove_tree (directory[, verbose=0, dry_run=0]) Recursively remove `directory' and all files and directories underneath it. Any errors are ignored (apart from being reported to ‘sys.stdout’ if `verbose' is true). ---------- Footnotes ---------- (1) http://nfs.sourceforge.net/#section_d  File: python.info, Node: distutils file_util — Single file operations, Next: distutils util — Miscellaneous other utility functions, Prev: distutils dir_util — Directory tree operations, Up: API Reference 17.9.10 ‘distutils.file_util’ — Single file operations ------------------------------------------------------ This module contains some utility functions for operating on individual files. -- Function: distutils.file_util.copy_file (src, dst[, preserve_mode=1, preserve_times=1, update=0, link=None, verbose=0, dry_run=0]) Copy file `src' to `dst'. If `dst' is a directory, then `src' is copied there with the same name; otherwise, it must be a filename. (If the file exists, it will be ruthlessly clobbered.) If `preserve_mode' is true (the default), the file’s mode (type and permission bits, or whatever is analogous on the current platform) is copied. If `preserve_times' is true (the default), the last-modified and last-access times are copied as well. If `update' is true, `src' will only be copied if `dst' does not exist, or if `dst' does exist but is older than `src'. `link' allows you to make hard links (using *note os.link(): a35.) or symbolic links (using *note os.symlink(): a3b.) instead of copying: set it to ‘'hard'’ or ‘'sym'’; if it is ‘None’ (the default), files are copied. Don’t set `link' on systems that don’t support it: *note copy_file(): 415a. doesn’t check if hard or symbolic linking is available. It uses ‘_copy_file_contents()’ to copy file contents. Return a tuple ‘(dest_name, copied)’: `dest_name' is the actual name of the output file, and `copied' is true if the file was copied (or would have been copied, if `dry_run' true). -- Function: distutils.file_util.move_file (src, dst[, verbose, dry_run]) Move file `src' to `dst'. If `dst' is a directory, the file will be moved into it with the same name; otherwise, `src' is just renamed to `dst'. Returns the new full name of the file. Warning: Handles cross-device moves on Unix using *note copy_file(): 415a. What about other systems? -- Function: distutils.file_util.write_file (filename, contents) Create a file called `filename' and write `contents' (a sequence of strings without line terminators) to it.  File: python.info, Node: distutils util — Miscellaneous other utility functions, Next: distutils dist — The Distribution class, Prev: distutils file_util — Single file operations, Up: API Reference 17.9.11 ‘distutils.util’ — Miscellaneous other utility functions ---------------------------------------------------------------- This module contains other assorted bits and pieces that don’t fit into any other utility module. -- Function: distutils.util.get_platform () Return a string that identifies the current platform. This is used mainly to distinguish platform-specific build directories and platform-specific built distributions. Typically includes the OS name and version and the architecture (as supplied by ‘os.uname()’), although the exact information included depends on the OS; e.g., on Linux, the kernel version isn’t particularly important. Examples of returned values: * ‘linux-i586’ * ‘linux-alpha’ * ‘solaris-2.6-sun4u’ For non-POSIX platforms, currently just returns ‘sys.platform’. For Mac OS X systems the OS version reflects the minimal version on which binaries will run (that is, the value of ‘MACOSX_DEPLOYMENT_TARGET’ during the build of Python), not the OS version of the current system. For universal binary builds on Mac OS X the architecture value reflects the universal binary status instead of the architecture of the current processor. For 32-bit universal binaries the architecture is ‘fat’, for 64-bit universal binaries the architecture is ‘fat64’, and for 4-way universal binaries the architecture is ‘universal’. Starting from Python 2.7 and Python 3.2 the architecture ‘fat3’ is used for a 3-way universal build (ppc, i386, x86_64) and ‘intel’ is used for a universal build with the i386 and x86_64 architectures Examples of returned values on Mac OS X: * ‘macosx-10.3-ppc’ * ‘macosx-10.3-fat’ * ‘macosx-10.5-universal’ * ‘macosx-10.6-intel’ -- Function: distutils.util.convert_path (pathname) Return ‘pathname’ as a name that will work on the native filesystem, i.e. split it on ‘/’ and put it back together again using the current directory separator. Needed because filenames in the setup script are always supplied in Unix style, and have to be converted to the local convention before we can actually use them in the filesystem. Raises *note ValueError: 1fb. on non-Unix-ish systems if `pathname' either starts or ends with a slash. -- Function: distutils.util.change_root (new_root, pathname) Return `pathname' with `new_root' prepended. If `pathname' is relative, this is equivalent to ‘os.path.join(new_root,pathname)’ Otherwise, it requires making `pathname' relative and then joining the two, which is tricky on DOS/Windows. -- Function: distutils.util.check_environ () Ensure that ‘os.environ’ has all the environment variables we guarantee that users can use in config files, command-line options, etc. Currently this includes: * ‘HOME’ - user’s home directory (Unix only) * ‘PLAT’ - description of the current platform, including hardware and OS (see *note get_platform(): 415f.) -- Function: distutils.util.subst_vars (s, local_vars) Perform shell/Perl-style variable substitution on `s'. Every occurrence of ‘$’ followed by a name is considered a variable, and variable is substituted by the value found in the `local_vars' dictionary, or in ‘os.environ’ if it’s not in `local_vars'. `os.environ' is first checked/augmented to guarantee that it contains certain values: see *note check_environ(): 4162. Raise *note ValueError: 1fb. for any variables not found in either `local_vars' or ‘os.environ’. Note that this is not a fully-fledged string interpolation function. A valid ‘$variable’ can consist only of upper and lower case letters, numbers and an underscore. No { } or ( ) style quoting is available. -- Function: distutils.util.split_quoted (s) Split a string up according to Unix shell-like rules for quotes and backslashes. In short: words are delimited by spaces, as long as those spaces are not escaped by a backslash, or inside a quoted string. Single and double quotes are equivalent, and the quote characters can be backslash-escaped. The backslash is stripped from any two-character escape sequence, leaving only the escaped character. The quote characters are stripped from any quoted string. Returns a list of words. -- Function: distutils.util.execute (func, args[, msg=None, verbose=0, dry_run=0]) Perform some action that affects the outside world (for instance, writing to the filesystem). Such actions are special because they are disabled by the `dry_run' flag. This method takes care of all that bureaucracy for you; all you have to do is supply the function to call and an argument tuple for it (to embody the “external action” being performed), and an optional message to print. -- Function: distutils.util.strtobool (val) Convert a string representation of truth to true (1) or false (0). True values are ‘y’, ‘yes’, ‘t’, ‘true’, ‘on’ and ‘1’; false values are ‘n’, ‘no’, ‘f’, ‘false’, ‘off’ and ‘0’. Raises *note ValueError: 1fb. if `val' is anything else. -- Function: distutils.util.byte_compile (py_files[, optimize=0, force=0, prefix=None, base_dir=None, verbose=1, dry_run=0, direct=None]) Byte-compile a collection of Python source files to ‘.pyc’ files in a ‘__pycache__’ subdirectory (see PEP 3147(1) and PEP 488(2)). `py_files' is a list of files to compile; any files that don’t end in ‘.py’ are silently skipped. `optimize' must be one of the following: * ‘0’ - don’t optimize * ‘1’ - normal optimization (like ‘python -O’) * ‘2’ - extra optimization (like ‘python -OO’) If `force' is true, all files are recompiled regardless of timestamps. The source filename encoded in each *note bytecode: 614. file defaults to the filenames listed in `py_files'; you can modify these with `prefix' and `basedir'. `prefix' is a string that will be stripped off of each source filename, and `base_dir' is a directory name that will be prepended (after `prefix' is stripped). You can supply either or both (or neither) of `prefix' and `base_dir', as you wish. If `dry_run' is true, doesn’t actually do anything that would affect the filesystem. Byte-compilation is either done directly in this interpreter process with the standard *note py_compile: d7. module, or indirectly by writing a temporary script and executing it. Normally, you should let *note byte_compile(): 4165. figure out to use direct compilation or not (see the source for details). The `direct' flag is used by the script generated in indirect mode; unless you know what you’re doing, leave it set to ‘None’. Changed in version 3.2.3: Create ‘.pyc’ files with an *note import magic tag: 3824. in their name, in a ‘__pycache__’ subdirectory instead of files without tag in the current directory. Changed in version 3.5: Create ‘.pyc’ files according to PEP 488(3). -- Function: distutils.util.rfc822_escape (header) Return a version of `header' escaped for inclusion in an RFC 822(4) header, by ensuring there are 8 spaces space after each newline. Note that it does no other modification of the string. ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-3147 (2) https://www.python.org/dev/peps/pep-0488 (3) https://www.python.org/dev/peps/pep-0488 (4) https://tools.ietf.org/html/rfc822.html  File: python.info, Node: distutils dist — The Distribution class, Next: distutils extension — The Extension class, Prev: distutils util — Miscellaneous other utility functions, Up: API Reference 17.9.12 ‘distutils.dist’ — The Distribution class ------------------------------------------------- This module provides the *note Distribution: 4118. class, which represents the module distribution being built/installed/distributed.  File: python.info, Node: distutils extension — The Extension class, Next: distutils debug — Distutils debug mode, Prev: distutils dist — The Distribution class, Up: API Reference 17.9.13 ‘distutils.extension’ — The Extension class --------------------------------------------------- This module provides the ‘Extension’ class, used to describe C/C++ extension modules in setup scripts.  File: python.info, Node: distutils debug — Distutils debug mode, Next: distutils errors — Distutils exceptions, Prev: distutils extension — The Extension class, Up: API Reference 17.9.14 ‘distutils.debug’ — Distutils debug mode ------------------------------------------------ This module provides the DEBUG flag.  File: python.info, Node: distutils errors — Distutils exceptions, Next: distutils fancy_getopt — Wrapper around the standard getopt module, Prev: distutils debug — Distutils debug mode, Up: API Reference 17.9.15 ‘distutils.errors’ — Distutils exceptions ------------------------------------------------- Provides exceptions used by the Distutils modules. Note that Distutils modules may raise standard exceptions; in particular, SystemExit is usually raised for errors that are obviously the end-user’s fault (eg. bad command-line arguments). This module is safe to use in ‘from ... import *’ mode; it only exports symbols whose names start with ‘Distutils’ and end with ‘Error’.  File: python.info, Node: distutils fancy_getopt — Wrapper around the standard getopt module, Next: distutils filelist — The FileList class, Prev: distutils errors — Distutils exceptions, Up: API Reference 17.9.16 ‘distutils.fancy_getopt’ — Wrapper around the standard getopt module ---------------------------------------------------------------------------- This module provides a wrapper around the standard *note getopt: 87. module that provides the following additional features: * short and long options are tied together * options have help strings, so *note fancy_getopt(): 416c. could potentially create a complete usage summary * options set attributes of a passed-in object * boolean options can have “negative aliases” — eg. if ‘--quiet’ is the “negative alias” of ‘--verbose’, then ‘--quiet’ on the command line sets `verbose' to false. -- Function: distutils.fancy_getopt.fancy_getopt (options, negative_opt, object, args) Wrapper function. `options' is a list of ‘(long_option, short_option, help_string)’ 3-tuples as described in the constructor for *note FancyGetopt: 416d. `negative_opt' should be a dictionary mapping option names to option names, both the key and value should be in the `options' list. `object' is an object which will be used to store values (see the *note getopt(): 87. method of the *note FancyGetopt: 416d. class). `args' is the argument list. Will use ‘sys.argv[1:]’ if you pass ‘None’ as `args'. -- Function: distutils.fancy_getopt.wrap_text (text, width) Wraps `text' to less than `width' wide. -- Class: distutils.fancy_getopt.FancyGetopt ([option_table=None]) The option_table is a list of 3-tuples: ‘(long_option, short_option, help_string)’ If an option takes an argument, its `long_option' should have ‘'='’ appended; `short_option' should just be a single character, no ‘':'’ in any case. `short_option' should be ‘None’ if a `long_option' doesn’t have a corresponding `short_option'. All option tuples must have long options. The *note FancyGetopt: 416d. class provides the following methods: -- Method: FancyGetopt.getopt ([args=None, object=None]) Parse command-line options in args. Store as attributes on `object'. If `args' is ‘None’ or not supplied, uses ‘sys.argv[1:]’. If `object' is ‘None’ or not supplied, creates a new ‘OptionDummy’ instance, stores option values there, and returns a tuple ‘(args, object)’. If `object' is supplied, it is modified in place and *note getopt(): 87. just returns `args'; in both cases, the returned `args' is a modified copy of the passed-in `args' list, which is left untouched. -- Method: FancyGetopt.get_option_order () Returns the list of ‘(option, value)’ tuples processed by the previous run of *note getopt(): 87. Raises *note RuntimeError: 2ba. if *note getopt(): 87. hasn’t been called yet. -- Method: FancyGetopt.generate_help ([header=None]) Generate help text (a list of strings, one per suggested line of output) from the option table for this *note FancyGetopt: 416d. object. If supplied, prints the supplied `header' at the top of the help.  File: python.info, Node: distutils filelist — The FileList class, Next: distutils log — Simple PEP 282-style logging, Prev: distutils fancy_getopt — Wrapper around the standard getopt module, Up: API Reference 17.9.17 ‘distutils.filelist’ — The FileList class ------------------------------------------------- This module provides the ‘FileList’ class, used for poking about the filesystem and building lists of files.  File: python.info, Node: distutils log — Simple PEP 282-style logging, Next: distutils spawn — Spawn a sub-process, Prev: distutils filelist — The FileList class, Up: API Reference 17.9.18 ‘distutils.log’ — Simple `PEP 282'-style logging --------------------------------------------------------  File: python.info, Node: distutils spawn — Spawn a sub-process, Next: distutils sysconfig — System configuration information, Prev: distutils log — Simple PEP 282-style logging, Up: API Reference 17.9.19 ‘distutils.spawn’ — Spawn a sub-process ----------------------------------------------- This module provides the ‘spawn()’ function, a front-end to various platform-specific functions for launching another program in a sub-process. Also provides ‘find_executable()’ to search the path for a given executable name.  File: python.info, Node: distutils sysconfig — System configuration information, Next: distutils text_file — The TextFile class, Prev: distutils spawn — Spawn a sub-process, Up: API Reference 17.9.20 ‘distutils.sysconfig’ — System configuration information ---------------------------------------------------------------- The *note distutils.sysconfig: 62. module provides access to Python’s low-level configuration information. The specific configuration variables available depend heavily on the platform and configuration. The specific variables depend on the build process for the specific version of Python being run; the variables are those found in the ‘Makefile’ and configuration header that are installed with Python on Unix systems. The configuration header is called ‘pyconfig.h’ for Python versions starting with 2.2, and ‘config.h’ for earlier versions of Python. Some additional functions are provided which perform some useful manipulations for other parts of the *note distutils: 39. package. -- Data: distutils.sysconfig.PREFIX The result of ‘os.path.normpath(sys.prefix)’. -- Data: distutils.sysconfig.EXEC_PREFIX The result of ‘os.path.normpath(sys.exec_prefix)’. -- Function: distutils.sysconfig.get_config_var (name) Return the value of a single variable. This is equivalent to ‘get_config_vars().get(name)’. -- Function: distutils.sysconfig.get_config_vars (...) Return a set of variable definitions. If there are no arguments, this returns a dictionary mapping names of configuration variables to values. If arguments are provided, they should be strings, and the return value will be a sequence giving the associated values. If a given name does not have a corresponding value, ‘None’ will be included for that variable. -- Function: distutils.sysconfig.get_config_h_filename () Return the full path name of the configuration header. For Unix, this will be the header generated by the ‘configure’ script; for other platforms the header will have been supplied directly by the Python source distribution. The file is a platform-specific text file. -- Function: distutils.sysconfig.get_makefile_filename () Return the full path name of the ‘Makefile’ used to build Python. For Unix, this will be a file generated by the ‘configure’ script; the meaning for other platforms will vary. The file is a platform-specific text file, if it exists. This function is only useful on POSIX platforms. -- Function: distutils.sysconfig.get_python_inc ([plat_specific[, prefix]]) Return the directory for either the general or platform-dependent C include files. If `plat_specific' is true, the platform-dependent include directory is returned; if false or omitted, the platform-independent directory is returned. If `prefix' is given, it is used as either the prefix instead of *note PREFIX: 4176, or as the exec-prefix instead of *note EXEC_PREFIX: 4177. if `plat_specific' is true. -- Function: distutils.sysconfig.get_python_lib ([plat_specific[, standard_lib[, prefix]]]) Return the directory for either the general or platform-dependent library installation. If `plat_specific' is true, the platform-dependent include directory is returned; if false or omitted, the platform-independent directory is returned. If `prefix' is given, it is used as either the prefix instead of *note PREFIX: 4176, or as the exec-prefix instead of *note EXEC_PREFIX: 4177. if `plat_specific' is true. If `standard_lib' is true, the directory for the standard library is returned rather than the directory for the installation of third-party extensions. The following function is only intended for use within the *note distutils: 39. package. -- Function: distutils.sysconfig.customize_compiler (compiler) Do any platform-specific customization of a *note distutils.ccompiler.CCompiler: 411c. instance. This function is only needed on Unix at this time, but should be called consistently to support forward-compatibility. It inserts the information that varies across Unix flavors and is stored in Python’s ‘Makefile’. This information includes the selected compiler, compiler and linker options, and the extension used by the linker for shared objects. This function is even more special-purpose, and should only be used from Python’s own build procedures. -- Function: distutils.sysconfig.set_python_build () Inform the *note distutils.sysconfig: 62. module that it is being used as part of the build process for Python. This changes a lot of relative locations for files, allowing them to be located in the build area rather than in an installed Python.  File: python.info, Node: distutils text_file — The TextFile class, Next: distutils version — Version number classes, Prev: distutils sysconfig — System configuration information, Up: API Reference 17.9.21 ‘distutils.text_file’ — The TextFile class -------------------------------------------------- This module provides the *note TextFile: 4181. class, which gives an interface to text files that (optionally) takes care of stripping comments, ignoring blank lines, and joining lines with backslashes. -- Class: distutils.text_file.TextFile ([filename=None, file=None, **options]) This class provides a file-like object that takes care of all the things you commonly want to do when processing a text file that has some line-by-line syntax: strip comments (as long as ‘#’ is your comment character), skip blank lines, join adjacent lines by escaping the newline (ie. backslash at end of line), strip leading and/or trailing whitespace. All of these are optional and independently controllable. The class provides a *note warn(): 4182. method so you can generate warning messages that report physical line number, even if the logical line in question spans multiple physical lines. Also provides *note unreadline(): 4183. for implementing line-at-a-time lookahead. *note TextFile: 4181. instances are create with either `filename', `file', or both. *note RuntimeError: 2ba. is raised if both are ‘None’. `filename' should be a string, and `file' a file object (or something that provides *note readline(): de. and *note close(): 4184. methods). It is recommended that you supply at least `filename', so that *note TextFile: 4181. can include it in warning messages. If `file' is not supplied, *note TextFile: 4181. creates its own using the *note open(): 4f0. built-in function. The options are all boolean, and affect the values returned by *note readline(): de. option name description default -------------------------------------------------------------------------- `strip_comments' strip from ‘'#'’ to end-of-line, true as well as any whitespace leading up to the ‘'#'’—unless it is escaped by a backslash `lstrip_ws' strip leading whitespace from each false line before returning it `rstrip_ws' strip trailing whitespace true (including line terminator!) from each line before returning it. `skip_blanks' skip lines that are empty *after* true stripping comments and whitespace. (If both lstrip_ws and rstrip_ws are false, then some lines may consist of solely whitespace: these will *not* be skipped, even if `skip_blanks' is true.) `join_lines' if a backslash is the last false non-newline character on a line after stripping comments and whitespace, join the following line to it to form one logical line; if N consecutive lines end with a backslash, then N+1 physical lines will be joined to form one logical line. `collapse_join' strip leading whitespace from false lines that are joined to their predecessor; only matters if ‘(join_lines and not lstrip_ws)’ Note that since `rstrip_ws' can strip the trailing newline, the semantics of *note readline(): de. must differ from those of the built-in file object’s *note readline(): de. method! In particular, *note readline(): de. returns ‘None’ for end-of-file: an empty string might just be a blank line (or an all-whitespace line), if `rstrip_ws' is true but `skip_blanks' is not. -- Method: open (filename) Open a new file `filename'. This overrides any `file' or `filename' constructor arguments. -- Method: close () Close the current file and forget everything we know about it (including the filename and the current line number). -- Method: warn (msg[, line=None]) Print (to stderr) a warning message tied to the current logical line in the current file. If the current logical line in the file spans multiple physical lines, the warning refers to the whole range, such as ‘"lines 3-5"’. If `line' is supplied, it overrides the current line number; it may be a list or tuple to indicate a range of physical lines, or an integer for a single physical line. -- Method: readline () Read and return a single logical line from the current file (or from an internal buffer if lines have previously been “unread” with *note unreadline(): 4183.). If the `join_lines' option is true, this may involve reading multiple physical lines concatenated into a single string. Updates the current line number, so calling *note warn(): 4182. after *note readline(): de. emits a warning about the physical line(s) just read. Returns ‘None’ on end-of-file, since the empty string can occur if `rstrip_ws' is true but `strip_blanks' is not. -- Method: readlines () Read and return the list of all logical lines remaining in the current file. This updates the current line number to the last line of the file. -- Method: unreadline (line) Push `line' (a string) onto an internal buffer that will be checked by future *note readline(): de. calls. Handy for implementing a parser with line-at-a-time lookahead. Note that lines that are “unread” with *note unreadline(): 4183. are not subsequently re-cleansed (whitespace stripped, or whatever) when read with *note readline(): de. If multiple calls are made to *note unreadline(): 4183. before a call to *note readline(): de, the lines will be returned most in most recent first order.  File: python.info, Node: distutils version — Version number classes, Next: distutils cmd — Abstract base class for Distutils commands, Prev: distutils text_file — The TextFile class, Up: API Reference 17.9.22 ‘distutils.version’ — Version number classes ----------------------------------------------------  File: python.info, Node: distutils cmd — Abstract base class for Distutils commands, Next: Creating a new Distutils command, Prev: distutils version — Version number classes, Up: API Reference 17.9.23 ‘distutils.cmd’ — Abstract base class for Distutils commands -------------------------------------------------------------------- This module supplies the abstract base class *note Command: 4107. -- Class: distutils.cmd.Command (dist) Abstract base class for defining command classes, the “worker bees” of the Distutils. A useful analogy for command classes is to think of them as subroutines with local variables called `options'. The options are declared in *note initialize_options(): 418a. and defined (given their final values) in *note finalize_options(): 418b, both of which must be defined by every command class. The distinction between the two is necessary because option values might come from the outside world (command line, config file, …), and any options dependent on other options must be computed after these outside influences have been processed — hence *note finalize_options(): 418b. The body of the subroutine, where it does all its work based on the values of its options, is the *note run(): 418c. method, which must also be implemented by every command class. The class constructor takes a single argument `dist', a *note Distribution: 4118. instance.  File: python.info, Node: Creating a new Distutils command, Next: distutils command — Individual Distutils commands, Prev: distutils cmd — Abstract base class for Distutils commands, Up: API Reference 17.9.24 Creating a new Distutils command ---------------------------------------- This section outlines the steps to create a new Distutils command. A new command lives in a module in the *note distutils.command: 3e. package. There is a sample template in that directory called ‘command_template’. Copy this file to a new module with the same name as the new command you’re implementing. This module should implement a class with the same name as the module (and the command). So, for instance, to create the command ‘peel_banana’ (so that users can run ‘setup.py peel_banana’), you’d copy ‘command_template’ to ‘distutils/command/peel_banana.py’, then edit it so that it’s implementing the class ‘peel_banana’, a subclass of *note distutils.cmd.Command: 4107. Subclasses of *note Command: 4107. must define the following methods. -- Method: Command.initialize_options () Set default values for all the options that this command supports. Note that these defaults may be overridden by other commands, by the setup script, by config files, or by the command-line. Thus, this is not the place to code dependencies between options; generally, *note initialize_options(): 418a. implementations are just a bunch of ‘self.foo = None’ assignments. -- Method: Command.finalize_options () Set final values for all the options that this command supports. This is always called as late as possible, ie. after any option assignments from the command-line or from other commands have been done. Thus, this is the place to code option dependencies: if `foo' depends on `bar', then it is safe to set `foo' from `bar' as long as `foo' still has the same value it was assigned in *note initialize_options(): 418a. -- Method: Command.run () A command’s raison d’etre: carry out the action it exists to perform, controlled by the options initialized in *note initialize_options(): 418a, customized by other commands, the setup script, the command-line, and config files, and finalized in *note finalize_options(): 418b. All terminal output and filesystem interaction should be done by *note run(): 418c. -- Attribute: Command.sub_commands `sub_commands' formalizes the notion of a “family” of commands, e.g. ‘install’ as the parent with sub-commands ‘install_lib’, ‘install_headers’, etc. The parent of a family of commands defines `sub_commands' as a class attribute; it’s a list of 2-tuples ‘(command_name, predicate)’, with `command_name' a string and `predicate' a function, a string or ‘None’. `predicate' is a method of the parent command that determines whether the corresponding command is applicable in the current situation. (E.g. ‘install_headers’ is only applicable if we have any C header files to install.) If `predicate' is ‘None’, that command is always applicable. `sub_commands' is usually defined at the `end' of a class, because predicates can be methods of the class, so they must already have been defined. The canonical example is the ‘install’ command.  File: python.info, Node: distutils command — Individual Distutils commands, Next: distutils command bdist — Build a binary installer, Prev: Creating a new Distutils command, Up: API Reference 17.9.25 ‘distutils.command’ — Individual Distutils commands -----------------------------------------------------------  File: python.info, Node: distutils command bdist — Build a binary installer, Next: distutils command bdist_packager — Abstract base class for packagers, Prev: distutils command — Individual Distutils commands, Up: API Reference 17.9.26 ‘distutils.command.bdist’ — Build a binary installer ------------------------------------------------------------  File: python.info, Node: distutils command bdist_packager — Abstract base class for packagers, Next: distutils command bdist_dumb — Build a “dumb” installer, Prev: distutils command bdist — Build a binary installer, Up: API Reference 17.9.27 ‘distutils.command.bdist_packager’ — Abstract base class for packagers ------------------------------------------------------------------------------  File: python.info, Node: distutils command bdist_dumb — Build a “dumb” installer, Next: distutils command bdist_msi — Build a Microsoft Installer binary package, Prev: distutils command bdist_packager — Abstract base class for packagers, Up: API Reference 17.9.28 ‘distutils.command.bdist_dumb’ — Build a “dumb” installer -----------------------------------------------------------------  File: python.info, Node: distutils command bdist_msi — Build a Microsoft Installer binary package, Next: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM, Prev: distutils command bdist_dumb — Build a “dumb” installer, Up: API Reference 17.9.29 ‘distutils.command.bdist_msi’ — Build a Microsoft Installer binary package ---------------------------------------------------------------------------------- -- Class: distutils.command.bdist_msi.bdist_msi Builds a Windows Installer(1) (.msi) binary package. In most cases, the ‘bdist_msi’ installer is a better choice than the ‘bdist_wininst’ installer, because it provides better support for Win64 platforms, allows administrators to perform non-interactive installations, and allows installation through group policies. ---------- Footnotes ---------- (1) https://msdn.microsoft.com/en-us/library/cc185688(VS.85).aspx  File: python.info, Node: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM, Next: distutils command bdist_wininst — Build a Windows installer, Prev: distutils command bdist_msi — Build a Microsoft Installer binary package, Up: API Reference 17.9.30 ‘distutils.command.bdist_rpm’ — Build a binary distribution as a Redhat RPM and SRPM --------------------------------------------------------------------------------------------  File: python.info, Node: distutils command bdist_wininst — Build a Windows installer, Next: distutils command sdist — Build a source distribution, Prev: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM, Up: API Reference 17.9.31 ‘distutils.command.bdist_wininst’ — Build a Windows installer --------------------------------------------------------------------- Deprecated since version 3.8: Use bdist_wheel (wheel packages) instead.  File: python.info, Node: distutils command sdist — Build a source distribution, Next: distutils command build — Build all files of a package, Prev: distutils command bdist_wininst — Build a Windows installer, Up: API Reference 17.9.32 ‘distutils.command.sdist’ — Build a source distribution ---------------------------------------------------------------  File: python.info, Node: distutils command build — Build all files of a package, Next: distutils command build_clib — Build any C libraries in a package, Prev: distutils command sdist — Build a source distribution, Up: API Reference 17.9.33 ‘distutils.command.build’ — Build all files of a package ----------------------------------------------------------------  File: python.info, Node: distutils command build_clib — Build any C libraries in a package, Next: distutils command build_ext — Build any extensions in a package, Prev: distutils command build — Build all files of a package, Up: API Reference 17.9.34 ‘distutils.command.build_clib’ — Build any C libraries in a package ---------------------------------------------------------------------------  File: python.info, Node: distutils command build_ext — Build any extensions in a package, Next: distutils command build_py — Build the py/ pyc files of a package, Prev: distutils command build_clib — Build any C libraries in a package, Up: API Reference 17.9.35 ‘distutils.command.build_ext’ — Build any extensions in a package -------------------------------------------------------------------------  File: python.info, Node: distutils command build_py — Build the py/ pyc files of a package, Next: distutils command build_scripts — Build the scripts of a package, Prev: distutils command build_ext — Build any extensions in a package, Up: API Reference 17.9.36 ‘distutils.command.build_py’ — Build the .py/.pyc files of a package ---------------------------------------------------------------------------- -- Class: distutils.command.build_py.build_py -- Class: distutils.command.build_py.build_py_2to3 Alternative implementation of build_py which also runs the 2to3 conversion library on each .py file that is going to be installed. To use this in a setup.py file for a distribution that is designed to run with both Python 2.x and 3.x, add: try: from distutils.command.build_py import build_py_2to3 as build_py except ImportError: from distutils.command.build_py import build_py to your setup.py, and later: cmdclass = {'build_py': build_py} to the invocation of setup().  File: python.info, Node: distutils command build_scripts — Build the scripts of a package, Next: distutils command clean — Clean a package build area, Prev: distutils command build_py — Build the py/ pyc files of a package, Up: API Reference 17.9.37 ‘distutils.command.build_scripts’ — Build the scripts of a package --------------------------------------------------------------------------  File: python.info, Node: distutils command clean — Clean a package build area, Next: distutils command config — Perform package configuration, Prev: distutils command build_scripts — Build the scripts of a package, Up: API Reference 17.9.38 ‘distutils.command.clean’ — Clean a package build area -------------------------------------------------------------- This command removes the temporary files created by ‘build’ and its subcommands, like intermediary compiled object files. With the ‘--all’ option, the complete build directory will be removed. Extension modules built *note in place: 40e0. will not be cleaned, as they are not in the build directory.  File: python.info, Node: distutils command config — Perform package configuration, Next: distutils command install — Install a package, Prev: distutils command clean — Clean a package build area, Up: API Reference 17.9.39 ‘distutils.command.config’ — Perform package configuration ------------------------------------------------------------------  File: python.info, Node: distutils command install — Install a package, Next: distutils command install_data — Install data files from a package, Prev: distutils command config — Perform package configuration, Up: API Reference 17.9.40 ‘distutils.command.install’ — Install a package -------------------------------------------------------  File: python.info, Node: distutils command install_data — Install data files from a package, Next: distutils command install_headers — Install C/C++ header files from a package, Prev: distutils command install — Install a package, Up: API Reference 17.9.41 ‘distutils.command.install_data’ — Install data files from a package ----------------------------------------------------------------------------  File: python.info, Node: distutils command install_headers — Install C/C++ header files from a package, Next: distutils command install_lib — Install library files from a package, Prev: distutils command install_data — Install data files from a package, Up: API Reference 17.9.42 ‘distutils.command.install_headers’ — Install C/C++ header files from a package ---------------------------------------------------------------------------------------  File: python.info, Node: distutils command install_lib — Install library files from a package, Next: distutils command install_scripts — Install script files from a package, Prev: distutils command install_headers — Install C/C++ header files from a package, Up: API Reference 17.9.43 ‘distutils.command.install_lib’ — Install library files from a package ------------------------------------------------------------------------------  File: python.info, Node: distutils command install_scripts — Install script files from a package, Next: distutils command register — Register a module with the Python Package Index, Prev: distutils command install_lib — Install library files from a package, Up: API Reference 17.9.44 ‘distutils.command.install_scripts’ — Install script files from a package ---------------------------------------------------------------------------------  File: python.info, Node: distutils command register — Register a module with the Python Package Index, Next: distutils command check — Check the meta-data of a package, Prev: distutils command install_scripts — Install script files from a package, Up: API Reference 17.9.45 ‘distutils.command.register’ — Register a module with the Python Package Index -------------------------------------------------------------------------------------- The ‘register’ command registers the package with the Python Package Index. This is described in more detail in PEP 301(1). ---------- Footnotes ---------- (1) https://www.python.org/dev/peps/pep-0301  File: python.info, Node: distutils command check — Check the meta-data of a package, Prev: distutils command register — Register a module with the Python Package Index, Up: API Reference 17.9.46 ‘distutils.command.check’ — Check the meta-data of a package -------------------------------------------------------------------- The ‘check’ command performs some tests on the meta-data of a package. For example, it verifies that all required meta-data are provided as the arguments passed to the ‘setup()’ function.  File: python.info, Node: Installing Python Modules Legacy version, Next: Python Module Index, Prev: Distributing Python Modules Legacy version, Up: Top 18 Installing Python Modules (Legacy version) ********************************************* Author: Greg Ward See also ........ *note Installing Python Modules: 7f5. The up to date module installation documentation. For regular Python usage, you almost certainly want that document rather than this one. Note: This document is being retained solely until the ‘setuptools’ documentation at ‘https://setuptools.readthedocs.io/en/latest/setuptools.html’ independently covers all of the relevant information currently included here. Note: This guide only covers the basic tools for building and distributing extensions that are provided as part of this version of Python. Third party tools offer easier to use and more secure alternatives. Refer to the quick recommendations section(1) in the Python Packaging User Guide for more information. * Menu: * Introduction: Introduction<17>. * Standard Build and Install:: * Alternate Installation:: * Custom Installation:: * Distutils Configuration Files:: * Building Extensions; Tips and Tricks: Building Extensions Tips and Tricks. ---------- Footnotes ---------- (1) https://packaging.python.org/guides/tool-recommendations/  File: python.info, Node: Introduction<17>, Next: Standard Build and Install, Up: Installing Python Modules Legacy version 18.1 Introduction ================= In Python 2.0, the ‘distutils’ API was first added to the standard library. This provided Linux distro maintainers with a standard way of converting Python projects into Linux distro packages, and system administrators with a standard way of installing them directly onto target systems. In the many years since Python 2.0 was released, tightly coupling the build system and package installer to the language runtime release cycle has turned out to be problematic, and it is now recommended that projects use the ‘pip’ package installer and the ‘setuptools’ build system, rather than using ‘distutils’ directly. See *note Installing Python Modules: 7f5. and *note Distributing Python Modules: 7f6. for more details. This legacy documentation is being retained only until we’re confident that the ‘setuptools’ documentation covers everything needed. * Menu: * Distutils based source distributions::  File: python.info, Node: Distutils based source distributions, Up: Introduction<17> 18.1.1 Distutils based source distributions ------------------------------------------- If you download a module source distribution, you can tell pretty quickly if it was packaged and distributed in the standard way, i.e. using the Distutils. First, the distribution’s name and version number will be featured prominently in the name of the downloaded archive, e.g. ‘foo-1.0.tar.gz’ or ‘widget-0.9.7.zip’. Next, the archive will unpack into a similarly-named directory: ‘foo-1.0’ or ‘widget-0.9.7’. Additionally, the distribution will contain a setup script ‘setup.py’, and a file named ‘README.txt’ or possibly just ‘README’, which should explain that building and installing the module distribution is a simple matter of running one command from a terminal: python setup.py install For Windows, this command should be run from a command prompt window (Start ‣ Accessories): setup.py install If all these things are true, then you already know how to build and install the modules you’ve just downloaded: Run the command above. Unless you need to install things in a non-standard way or customize the build process, you don’t really need this manual. Or rather, the above command is everything you need to get out of this manual.  File: python.info, Node: Standard Build and Install, Next: Alternate Installation, Prev: Introduction<17>, Up: Installing Python Modules Legacy version 18.2 Standard Build and Install =============================== As described in section *note Distutils based source distributions: 41ad, building and installing a module distribution using the Distutils is usually one simple command to run from a terminal: python setup.py install * Menu: * Platform variations:: * Splitting the job up:: * How building works:: * How installation works::  File: python.info, Node: Platform variations, Next: Splitting the job up, Up: Standard Build and Install 18.2.1 Platform variations -------------------------- You should always run the setup command from the distribution root directory, i.e. the top-level subdirectory that the module source distribution unpacks into. For example, if you’ve just downloaded a module source distribution ‘foo-1.0.tar.gz’ onto a Unix system, the normal thing to do is: gunzip -c foo-1.0.tar.gz | tar xf - # unpacks into directory foo-1.0 cd foo-1.0 python setup.py install On Windows, you’d probably download ‘foo-1.0.zip’. If you downloaded the archive file to ‘C:\Temp’, then it would unpack into ‘C:\Temp\foo-1.0’; you can use either an archive manipulator with a graphical user interface (such as WinZip) or a command-line tool (such as ‘unzip’ or ‘pkunzip’) to unpack the archive. Then, open a command prompt window and run: cd c:\Temp\foo-1.0 python setup.py install  File: python.info, Node: Splitting the job up, Next: How building works, Prev: Platform variations, Up: Standard Build and Install 18.2.2 Splitting the job up --------------------------- Running ‘setup.py install’ builds and installs all modules in one run. If you prefer to work incrementally—especially useful if you want to customize the build process, or if things are going wrong—you can use the setup script to do one thing at a time. This is particularly helpful when the build and install will be done by different users—for example, you might want to build a module distribution and hand it off to a system administrator for installation (or do it yourself, with super-user privileges). For example, you can build everything in one step, and then install everything in a second step, by invoking the setup script twice: python setup.py build python setup.py install If you do this, you will notice that running the ‘install’ command first runs the ‘build’ command, which—in this case—quickly notices that it has nothing to do, since everything in the ‘build’ directory is up-to-date. You may not need this ability to break things down often if all you do is install modules downloaded off the ‘net, but it’s very handy for more advanced tasks. If you get into distributing your own Python modules and extensions, you’ll run lots of individual Distutils commands on their own.  File: python.info, Node: How building works, Next: How installation works, Prev: Splitting the job up, Up: Standard Build and Install 18.2.3 How building works ------------------------- As implied above, the ‘build’ command is responsible for putting the files to install into a `build directory'. By default, this is ‘build’ under the distribution root; if you’re excessively concerned with speed, or want to keep the source tree pristine, you can change the build directory with the ‘--build-base’ option. For example: python setup.py build --build-base=/path/to/pybuild/foo-1.0 (Or you could do this permanently with a directive in your system or personal Distutils configuration file; see section *note Distutils Configuration Files: 41b6.) Normally, this isn’t necessary. The default layout for the build tree is as follows: --- build/ --- lib/ or --- build/ --- lib./ temp./ where ‘’ expands to a brief description of the current OS/hardware platform and Python version. The first form, with just a ‘lib’ directory, is used for “pure module distributions”—that is, module distributions that include only pure Python modules. If a module distribution contains any extensions (modules written in C/C++), then the second form, with two ‘’ directories, is used. In that case, the ‘temp.`plat'’ directory holds temporary files generated by the compile/link process that don’t actually get installed. In either case, the ‘lib’ (or ‘lib.`plat'’) directory contains all Python modules (pure Python and extensions) that will be installed. In the future, more directories will be added to handle Python scripts, documentation, binary executables, and whatever else is needed to handle the job of installing Python modules and applications.  File: python.info, Node: How installation works, Prev: How building works, Up: Standard Build and Install 18.2.4 How installation works ----------------------------- After the ‘build’ command runs (whether you run it explicitly, or the ‘install’ command does it for you), the work of the ‘install’ command is relatively simple: all it has to do is copy everything under ‘build/lib’ (or ‘build/lib.`plat'’) to your chosen installation directory. If you don’t choose an installation directory—i.e., if you just run ‘setup.py install’—then the ‘install’ command installs to the standard location for third-party Python modules. This location varies by platform and by how you built/installed Python itself. On Unix (and Mac OS X, which is also Unix-based), it also depends on whether the module distribution being installed is pure Python or contains extensions (“non-pure”): Platform Standard installation location Default value Notes --------------------------------------------------------------------------------------------------------------------------------------------------- Unix (pure) ‘`prefix'/lib/python`X.Y'/site-packages’ ‘/usr/local/lib/python`X.Y'/site-packages’ (1) Unix (non-pure) ‘`exec-prefix'/lib/python`X.Y'/site-packages’ ‘/usr/local/lib/python`X.Y'/site-packages’ (1) Windows ‘`prefix'\Lib\site-packages’ ‘C:\Python`XY'\Lib\site-packages’ (2) Notes: 1. Most Linux distributions include Python as a standard part of the system, so ‘`prefix'’ and ‘`exec-prefix'’ are usually both ‘/usr’ on Linux. If you build Python yourself on Linux (or any Unix-like system), the default ‘`prefix'’ and ‘`exec-prefix'’ are ‘/usr/local’. 2. The default installation directory on Windows was ‘C:\Program Files\Python’ under Python 1.6a1, 1.5.2, and earlier. ‘`prefix'’ and ‘`exec-prefix'’ stand for the directories that Python is installed to, and where it finds its libraries at run-time. They are always the same under Windows, and very often the same under Unix and Mac OS X. You can find out what your Python installation uses for ‘`prefix'’ and ‘`exec-prefix'’ by running Python in interactive mode and typing a few simple commands. Under Unix, just type ‘python’ at the shell prompt. Under Windows, choose Start ‣ Programs ‣ Python X.Y ‣ Python (command line). Once the interpreter is started, you type Python code at the prompt. For example, on my Linux system, I type the three Python statements shown below, and get the output as shown, to find out my ‘`prefix'’ and ‘`exec-prefix'’: Python 2.4 (#26, Aug 7 2004, 17:19:02) Type "help", "copyright", "credits" or "license" for more information. >>> import sys >>> sys.prefix '/usr' >>> sys.exec_prefix '/usr' A few other placeholders are used in this document: ‘`X.Y'’ stands for the version of Python, for example ‘3.2’; ‘`abiflags'’ will be replaced by the value of *note sys.abiflags: 264. or the empty string for platforms which don’t define ABI flags; ‘`distname'’ will be replaced by the name of the module distribution being installed. Dots and capitalization are important in the paths; for example, a value that uses ‘python3.2’ on UNIX will typically use ‘Python32’ on Windows. If you don’t want to install modules to the standard location, or if you don’t have permission to write there, then you need to read about alternate installations in section *note Alternate Installation: 41b9. If you want to customize your installation directories more heavily, see section *note Custom Installation: 41ba. on custom installations.  File: python.info, Node: Alternate Installation, Next: Custom Installation, Prev: Standard Build and Install, Up: Installing Python Modules Legacy version 18.3 Alternate Installation =========================== Often, it is necessary or desirable to install modules to a location other than the standard location for third-party Python modules. For example, on a Unix system you might not have permission to write to the standard third-party module directory. Or you might wish to try out a module before making it a standard part of your local Python installation. This is especially true when upgrading a distribution already present: you want to make sure your existing base of scripts still works with the new version before actually upgrading. The Distutils ‘install’ command is designed to make installing module distributions to an alternate location simple and painless. The basic idea is that you supply a base directory for the installation, and the ‘install’ command picks a set of directories (called an `installation scheme') under this base directory in which to install files. The details differ across platforms, so read whichever of the following sections applies to you. Note that the various alternate installation schemes are mutually exclusive: you can pass ‘--user’, or ‘--home’, or ‘--prefix’ and ‘--exec-prefix’, or ‘--install-base’ and ‘--install-platbase’, but you can’t mix from these groups. * Menu: * Alternate installation; the user scheme: Alternate installation the user scheme. * Alternate installation; the home scheme: Alternate installation the home scheme. * Alternate installation; Unix (the prefix scheme): Alternate installation Unix the prefix scheme. * Alternate installation; Windows (the prefix scheme): Alternate installation Windows the prefix scheme.  File: python.info, Node: Alternate installation the user scheme, Next: Alternate installation the home scheme, Up: Alternate Installation 18.3.1 Alternate installation: the user scheme ---------------------------------------------- This scheme is designed to be the most convenient solution for users that don’t have write permission to the global site-packages directory or don’t want to install into it. It is enabled with a simple option: python setup.py install --user Files will be installed into subdirectories of *note site.USER_BASE: ff3. (written as ‘`userbase'’ hereafter). This scheme installs pure Python modules and extension modules in the same location (also known as *note site.USER_SITE: fe1.). Here are the values for UNIX, including Mac OS X: Type of file Installation directory ------------------------------------------------------------------------------------ modules ‘`userbase'/lib/python`X.Y'/site-packages’ scripts ‘`userbase'/bin’ data ‘`userbase'’ C headers ‘`userbase'/include/python`X.Y'`abiflags'/`distname'’ And here are the values used on Windows: Type of file Installation directory ------------------------------------------------------------------------------------ modules ‘`userbase'\Python`XY'\site-packages’ scripts ‘`userbase'\Python`XY'\Scripts’ data ‘`userbase'’ C headers ‘`userbase'\Python`XY'\Include{distname}’ The advantage of using this scheme compared to the other ones described below is that the user site-packages directory is under normal conditions always included in *note sys.path: 488. (see *note site: eb. for more information), which means that there is no additional step to perform after running the ‘setup.py’ script to finalize the installation. The ‘build_ext’ command also has a ‘--user’ option to add ‘`userbase'/include’ to the compiler search path for header files and ‘`userbase'/lib’ to the compiler search path for libraries as well as to the runtime search path for shared C libraries (rpath).  File: python.info, Node: Alternate installation the home scheme, Next: Alternate installation Unix the prefix scheme, Prev: Alternate installation the user scheme, Up: Alternate Installation 18.3.2 Alternate installation: the home scheme ---------------------------------------------- The idea behind the “home scheme” is that you build and maintain a personal stash of Python modules. This scheme’s name is derived from the idea of a “home” directory on Unix, since it’s not unusual for a Unix user to make their home directory have a layout similar to ‘/usr/’ or ‘/usr/local/’. This scheme can be used by anyone, regardless of the operating system they are installing for. Installing a new module distribution is as simple as python setup.py install --home= where you can supply any directory you like for the ‘--home’ option. On Unix, lazy typists can just type a tilde (‘~’); the ‘install’ command will expand this to your home directory: python setup.py install --home=~ To make Python find the distributions installed with this scheme, you may have to *note modify Python’s search path: 41bf. or edit ‘sitecustomize’ (see *note site: eb.) to call *note site.addsitedir(): 343f. or edit *note sys.path: 488. The ‘--home’ option defines the installation base directory. Files are installed to the following directories under the installation base as follows: Type of file Installation directory ------------------------------------------------------------------------------------ modules ‘`home'/lib/python’ scripts ‘`home'/bin’ data ‘`home'’ C headers ‘`home'/include/python/`distname'’ (Mentally replace slashes with backslashes if you’re on Windows.)  File: python.info, Node: Alternate installation Unix the prefix scheme, Next: Alternate installation Windows the prefix scheme, Prev: Alternate installation the home scheme, Up: Alternate Installation 18.3.3 Alternate installation: Unix (the prefix scheme) ------------------------------------------------------- The “prefix scheme” is useful when you wish to use one Python installation to perform the build/install (i.e., to run the setup script), but install modules into the third-party module directory of a different Python installation (or something that looks like a different Python installation). If this sounds a trifle unusual, it is—that’s why the user and home schemes come before. However, there are at least two known cases where the prefix scheme will be useful. First, consider that many Linux distributions put Python in ‘/usr’, rather than the more traditional ‘/usr/local’. This is entirely appropriate, since in those cases Python is part of “the system” rather than a local add-on. However, if you are installing Python modules from source, you probably want them to go in ‘/usr/local/lib/python2.`X'’ rather than ‘/usr/lib/python2.`X'’. This can be done with /usr/bin/python setup.py install --prefix=/usr/local Another possibility is a network filesystem where the name used to write to a remote directory is different from the name used to read it: for example, the Python interpreter accessed as ‘/usr/local/bin/python’ might search for modules in ‘/usr/local/lib/python2.`X'’, but those modules would have to be installed to, say, ‘/mnt/`@server'/export/lib/python2.`X'’. This could be done with /usr/local/bin/python setup.py install --prefix=/mnt/@server/export In either case, the ‘--prefix’ option defines the installation base, and the ‘--exec-prefix’ option defines the platform-specific installation base, which is used for platform-specific files. (Currently, this just means non-pure module distributions, but could be expanded to C libraries, binary executables, etc.) If ‘--exec-prefix’ is not supplied, it defaults to ‘--prefix’. Files are installed as follows: Type of file Installation directory ------------------------------------------------------------------------------------- Python modules ‘`prefix'/lib/python`X.Y'/site-packages’ extension modules ‘`exec-prefix'/lib/python`X.Y'/site-packages’ scripts ‘`prefix'/bin’ data ‘`prefix'’ C headers ‘`prefix'/include/python`X.Y'`abiflags'/`distname'’ There is no requirement that ‘--prefix’ or ‘--exec-prefix’ actually point to an alternate Python installation; if the directories listed above do not already exist, they are created at installation time. Incidentally, the real reason the prefix scheme is important is simply that a standard Unix installation uses the prefix scheme, but with ‘--prefix’ and ‘--exec-prefix’ supplied by Python itself as ‘sys.prefix’ and ‘sys.exec_prefix’. Thus, you might think you’ll never use the prefix scheme, but every time you run ‘python setup.py install’ without any other options, you’re using it. Note that installing extensions to an alternate Python installation has no effect on how those extensions are built: in particular, the Python header files (‘Python.h’ and friends) installed with the Python interpreter used to run the setup script will be used in compiling extensions. It is your responsibility to ensure that the interpreter used to run extensions installed in this way is compatible with the interpreter used to build them. The best way to do this is to ensure that the two interpreters are the same version of Python (possibly different builds, or possibly copies of the same build). (Of course, if your ‘--prefix’ and ‘--exec-prefix’ don’t even point to an alternate Python installation, this is immaterial.)  File: python.info, Node: Alternate installation Windows the prefix scheme, Prev: Alternate installation Unix the prefix scheme, Up: Alternate Installation 18.3.4 Alternate installation: Windows (the prefix scheme) ---------------------------------------------------------- Windows has no concept of a user’s home directory, and since the standard Python installation under Windows is simpler than under Unix, the ‘--prefix’ option has traditionally been used to install additional packages in separate locations on Windows. python setup.py install --prefix="\Temp\Python" to install modules to the ‘\Temp\Python’ directory on the current drive. The installation base is defined by the ‘--prefix’ option; the ‘--exec-prefix’ option is not supported under Windows, which means that pure Python modules and extension modules are installed into the same location. Files are installed as follows: Type of file Installation directory ----------------------------------------------------------------------------------- modules ‘`prefix'\Lib\site-packages’ scripts ‘`prefix'\Scripts’ data ‘`prefix'’ C headers ‘`prefix'\Include{distname}’  File: python.info, Node: Custom Installation, Next: Distutils Configuration Files, Prev: Alternate Installation, Up: Installing Python Modules Legacy version 18.4 Custom Installation ======================== Sometimes, the alternate installation schemes described in section *note Alternate Installation: 41b9. just don’t do what you want. You might want to tweak just one or two directories while keeping everything under the same base directory, or you might want to completely redefine the installation scheme. In either case, you’re creating a `custom installation scheme'. To create a custom installation scheme, you start with one of the alternate schemes and override some of the installation directories used for the various types of files, using these options: Type of file Override option ------------------------------------------------------- Python modules ‘--install-purelib’ extension modules ‘--install-platlib’ all modules ‘--install-lib’ scripts ‘--install-scripts’ data ‘--install-data’ C headers ‘--install-headers’ These override options can be relative, absolute, or explicitly defined in terms of one of the installation base directories. (There are two installation base directories, and they are normally the same—they only differ when you use the Unix “prefix scheme” and supply different ‘--prefix’ and ‘--exec-prefix’ options; using ‘--install-lib’ will override values computed or given for ‘--install-purelib’ and ‘--install-platlib’, and is recommended for schemes that don’t make a difference between Python and extension modules.) For example, say you’re installing a module distribution to your home directory under Unix—but you want scripts to go in ‘~/scripts’ rather than ‘~/bin’. As you might expect, you can override this directory with the ‘--install-scripts’ option; in this case, it makes most sense to supply a relative path, which will be interpreted relative to the installation base directory (your home directory, in this case): python setup.py install --home=~ --install-scripts=scripts Another Unix example: suppose your Python installation was built and installed with a prefix of ‘/usr/local/python’, so under a standard installation scripts will wind up in ‘/usr/local/python/bin’. If you want them in ‘/usr/local/bin’ instead, you would supply this absolute directory for the ‘--install-scripts’ option: python setup.py install --install-scripts=/usr/local/bin (This performs an installation using the “prefix scheme”, where the prefix is whatever your Python interpreter was installed with— ‘/usr/local/python’ in this case.) If you maintain Python on Windows, you might want third-party modules to live in a subdirectory of ‘`prefix'’, rather than right in ‘`prefix'’ itself. This is almost as easy as customizing the script installation directory—you just have to remember that there are two types of modules to worry about, Python and extension modules, which can conveniently be both controlled by one option: python setup.py install --install-lib=Site The specified installation directory is relative to ‘`prefix'’. Of course, you also have to ensure that this directory is in Python’s module search path, such as by putting a ‘.pth’ file in a site directory (see *note site: eb.). See section *note Modifying Python’s Search Path: 41bf. to find out how to modify Python’s search path. If you want to define an entire installation scheme, you just have to supply all of the installation directory options. The recommended way to do this is to supply relative paths; for example, if you want to maintain all Python module-related files under ‘python’ in your home directory, and you want a separate directory for each platform that you use your home directory from, you might define the following installation scheme: python setup.py install --home=~ \ --install-purelib=python/lib \ --install-platlib=python/lib.$PLAT \ --install-scripts=python/scripts --install-data=python/data or, equivalently, python setup.py install --home=~/python \ --install-purelib=lib \ --install-platlib='lib.$PLAT' \ --install-scripts=scripts --install-data=data ‘$PLAT’ is not (necessarily) an environment variable—it will be expanded by the Distutils as it parses your command line options, just as it does when parsing your configuration file(s). Obviously, specifying the entire installation scheme every time you install a new module distribution would be very tedious. Thus, you can put these options into your Distutils config file (see section *note Distutils Configuration Files: 41b6.): [install] install-base=$HOME install-purelib=python/lib install-platlib=python/lib.$PLAT install-scripts=python/scripts install-data=python/data or, equivalently, [install] install-base=$HOME/python install-purelib=lib install-platlib=lib.$PLAT install-scripts=scripts install-data=data Note that these two are `not' equivalent if you supply a different installation base directory when you run the setup script. For example, python setup.py install --install-base=/tmp would install pure modules to ‘/tmp/python/lib’ in the first case, and to ‘/tmp/lib’ in the second case. (For the second case, you probably want to supply an installation base of ‘/tmp/python’.) You probably noticed the use of ‘$HOME’ and ‘$PLAT’ in the sample configuration file input. These are Distutils configuration variables, which bear a strong resemblance to environment variables. In fact, you can use environment variables in config files on platforms that have such a notion but the Distutils additionally define a few extra variables that may not be in your environment, such as ‘$PLAT’. (And of course, on systems that don’t have environment variables, such as Mac OS 9, the configuration variables supplied by the Distutils are the only ones you can use.) See section *note Distutils Configuration Files: 41b6. for details. Note: When a *note virtual environment: 3321. is activated, any options that change the installation path will be ignored from all distutils configuration files to prevent inadvertently installing projects outside of the virtual environment. * Menu: * Modifying Python’s Search Path::  File: python.info, Node: Modifying Python’s Search Path, Up: Custom Installation 18.4.1 Modifying Python’s Search Path ------------------------------------- When the Python interpreter executes an *note import: c1d. statement, it searches for both Python code and extension modules along a search path. A default value for the path is configured into the Python binary when the interpreter is built. You can determine the path by importing the *note sys: fd. module and printing the value of ‘sys.path’. $ python Python 2.2 (#11, Oct 3 2002, 13:31:27) [GCC 2.96 20000731 (Red Hat Linux 7.3 2.96-112)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import sys >>> sys.path ['', '/usr/local/lib/python2.3', '/usr/local/lib/python2.3/plat-linux2', '/usr/local/lib/python2.3/lib-tk', '/usr/local/lib/python2.3/lib-dynload', '/usr/local/lib/python2.3/site-packages'] >>> The null string in ‘sys.path’ represents the current working directory. The expected convention for locally installed packages is to put them in the ‘`…'/site-packages/’ directory, but you may want to install Python modules into some arbitrary directory. For example, your site may have a convention of keeping all software related to the web server under ‘/www’. Add-on Python modules might then belong in ‘/www/python’, and in order to import them, this directory must be added to ‘sys.path’. There are several different ways to add the directory. The most convenient way is to add a path configuration file to a directory that’s already on Python’s path, usually to the ‘.../site-packages/’ directory. Path configuration files have an extension of ‘.pth’, and each line must contain a single path that will be appended to ‘sys.path’. (Because the new paths are appended to ‘sys.path’, modules in the added directories will not override standard modules. This means you can’t use this mechanism for installing fixed versions of standard modules.) Paths can be absolute or relative, in which case they’re relative to the directory containing the ‘.pth’ file. See the documentation of the *note site: eb. module for more information. A slightly less convenient way is to edit the ‘site.py’ file in Python’s standard library, and modify ‘sys.path’. ‘site.py’ is automatically imported when the Python interpreter is executed, unless the *note -S: b24. switch is supplied to suppress this behaviour. So you could simply edit ‘site.py’ and add two lines to it: import sys sys.path.append('/www/python/') However, if you reinstall the same major version of Python (perhaps when upgrading from 2.2 to 2.2.2, for example) ‘site.py’ will be overwritten by the stock version. You’d have to remember that it was modified and save a copy before doing the installation. There are two environment variables that can modify ‘sys.path’. *note PYTHONHOME: 4d6. sets an alternate value for the prefix of the Python installation. For example, if *note PYTHONHOME: 4d6. is set to ‘/www/python’, the search path will be set to ‘['', '/www/python/lib/pythonX.Y/', '/www/python/lib/pythonX.Y/plat-linux2', ...]’. The *note PYTHONPATH: 953. variable can be set to a list of paths that will be added to the beginning of ‘sys.path’. For example, if *note PYTHONPATH: 953. is set to ‘/www/python:/opt/py’, the search path will begin with ‘['/www/python', '/opt/py']’. (Note that directories must exist in order to be added to ‘sys.path’; the *note site: eb. module removes paths that don’t exist.) Finally, ‘sys.path’ is just a regular Python list, so any Python application can modify it by adding or removing entries.  File: python.info, Node: Distutils Configuration Files, Next: Building Extensions Tips and Tricks, Prev: Custom Installation, Up: Installing Python Modules Legacy version 18.5 Distutils Configuration Files ================================== As mentioned above, you can use Distutils configuration files to record personal or site preferences for any Distutils options. That is, any option to any command can be stored in one of two or three (depending on your platform) configuration files, which will be consulted before the command-line is parsed. This means that configuration files will override default values, and the command-line will in turn override configuration files. Furthermore, if multiple configuration files apply, values from “earlier” files are overridden by “later” files. * Menu: * Location and names of config files:: * Syntax of config files::  File: python.info, Node: Location and names of config files, Next: Syntax of config files, Up: Distutils Configuration Files 18.5.1 Location and names of config files ----------------------------------------- The names and locations of the configuration files vary slightly across platforms. On Unix and Mac OS X, the three configuration files (in the order they are processed) are: Type of file Location and filename Notes ---------------------------------------------------------------------------------------------- system ‘`prefix'/lib/python`ver'/distutils/distutils.cfg’ (1) personal ‘$HOME/.pydistutils.cfg’ (2) local ‘setup.cfg’ (3) And on Windows, the configuration files are: Type of file Location and filename Notes ------------------------------------------------------------------------------------- system ‘`prefix'\Lib\distutils\distutils.cfg’ (4) personal ‘%HOME%\pydistutils.cfg’ (5) local ‘setup.cfg’ (3) On all platforms, the “personal” file can be temporarily disabled by passing the ‘–no-user-cfg’ option. Notes: 1. Strictly speaking, the system-wide configuration file lives in the directory where the Distutils are installed; under Python 1.6 and later on Unix, this is as shown. For Python 1.5.2, the Distutils will normally be installed to ‘`prefix'/lib/python1.5/site-packages/distutils’, so the system configuration file should be put there under Python 1.5.2. 2. On Unix, if the ‘HOME’ environment variable is not defined, the user’s home directory will be determined with the ‘getpwuid()’ function from the standard *note pwd: d6. module. This is done by the *note os.path.expanduser(): 1fe. function used by Distutils. 3. I.e., in the current directory (usually the location of the setup script). 4. (See also note (1).) Under Python 1.6 and later, Python’s default “installation prefix” is ‘C:\Python’, so the system configuration file is normally ‘C:\Python\Lib\distutils\distutils.cfg’. Under Python 1.5.2, the default prefix was ‘C:\Program Files\Python’, and the Distutils were not part of the standard library—so the system configuration file would be ‘C:\Program Files\Python\distutils\distutils.cfg’ in a standard Python 1.5.2 installation under Windows. 5. On Windows, if the ‘HOME’ environment variable is not defined, ‘USERPROFILE’ then ‘HOMEDRIVE’ and ‘HOMEPATH’ will be tried. This is done by the *note os.path.expanduser(): 1fe. function used by Distutils.  File: python.info, Node: Syntax of config files, Prev: Location and names of config files, Up: Distutils Configuration Files 18.5.2 Syntax of config files ----------------------------- The Distutils configuration files all have the same syntax. The config files are grouped into sections. There is one section for each Distutils command, plus a ‘global’ section for global options that affect every command. Each section consists of one option per line, specified as ‘option=value’. For example, the following is a complete config file that just forces all commands to run quietly by default: [global] verbose=0 If this is installed as the system config file, it will affect all processing of any Python module distribution by any user on the current system. If it is installed as your personal config file (on systems that support them), it will affect only module distributions processed by you. And if it is used as the ‘setup.cfg’ for a particular module distribution, it affects only that distribution. You could override the default “build base” directory and make the ‘build*’ commands always forcibly rebuild all files with the following: [build] build-base=blib force=1 which corresponds to the command-line arguments python setup.py build --build-base=blib --force except that including the ‘build’ command on the command-line means that command will be run. Including a particular command in config files has no such implication; it only means that if the command is run, the options in the config file will apply. (Or if other commands that derive values from it are run, they will use the values in the config file.) You can find out the complete list of options for any command using the ‘--help’ option, e.g.: python setup.py build --help and you can find out the complete list of global options by using ‘--help’ without a command: python setup.py --help See also the “Reference” section of the “Distributing Python Modules” manual.  File: python.info, Node: Building Extensions Tips and Tricks, Prev: Distutils Configuration Files, Up: Installing Python Modules Legacy version 18.6 Building Extensions: Tips and Tricks ========================================= Whenever possible, the Distutils try to use the configuration information made available by the Python interpreter used to run the ‘setup.py’ script. For example, the same compiler and linker flags used to compile Python will also be used for compiling extensions. Usually this will work well, but in complicated situations this might be inappropriate. This section discusses how to override the usual Distutils behaviour. * Menu: * Tweaking compiler/linker flags:: * Using non-Microsoft compilers on Windows::  File: python.info, Node: Tweaking compiler/linker flags, Next: Using non-Microsoft compilers on Windows, Up: Building Extensions Tips and Tricks 18.6.1 Tweaking compiler/linker flags ------------------------------------- Compiling a Python extension written in C or C++ will sometimes require specifying custom flags for the compiler and linker in order to use a particular library or produce a special kind of object code. This is especially true if the extension hasn’t been tested on your platform, or if you’re trying to cross-compile Python. In the most general case, the extension author might have foreseen that compiling the extensions would be complicated, and provided a ‘Setup’ file for you to edit. This will likely only be done if the module distribution contains many separate extension modules, or if they often require elaborate sets of compiler flags in order to work. A ‘Setup’ file, if present, is parsed in order to get a list of extensions to build. Each line in a ‘Setup’ describes a single module. Lines have the following structure: module ... [sourcefile ...] [cpparg ...] [library ...] Let’s examine each of the fields in turn. * `module' is the name of the extension module to be built, and should be a valid Python identifier. You can’t just change this in order to rename a module (edits to the source code would also be needed), so this should be left alone. * `sourcefile' is anything that’s likely to be a source code file, at least judging by the filename. Filenames ending in ‘.c’ are assumed to be written in C, filenames ending in ‘.C’, ‘.cc’, and ‘.c++’ are assumed to be C++, and filenames ending in ‘.m’ or ‘.mm’ are assumed to be in Objective C. * `cpparg' is an argument for the C preprocessor, and is anything starting with ‘-I’, ‘-D’, ‘-U’ or ‘-C’. * `library' is anything ending in ‘.a’ or beginning with ‘-l’ or ‘-L’. If a particular platform requires a special library on your platform, you can add it by editing the ‘Setup’ file and running ‘python setup.py build’. For example, if the module defined by the line foo foomodule.c must be linked with the math library ‘libm.a’ on your platform, simply add ‘-lm’ to the line: foo foomodule.c -lm Arbitrary switches intended for the compiler or the linker can be supplied with the ‘-Xcompiler’ `arg' and ‘-Xlinker’ `arg' options: foo foomodule.c -Xcompiler -o32 -Xlinker -shared -lm The next option after ‘-Xcompiler’ and ‘-Xlinker’ will be appended to the proper command line, so in the above example the compiler will be passed the ‘-o32’ option, and the linker will be passed ‘-shared’. If a compiler option requires an argument, you’ll have to supply multiple ‘-Xcompiler’ options; for example, to pass ‘-x c++’ the ‘Setup’ file would have to contain ‘-Xcompiler -x -Xcompiler c++’. Compiler flags can also be supplied through setting the ‘CFLAGS’ environment variable. If set, the contents of ‘CFLAGS’ will be added to the compiler flags specified in the ‘Setup’ file.  File: python.info, Node: Using non-Microsoft compilers on Windows, Prev: Tweaking compiler/linker flags, Up: Building Extensions Tips and Tricks 18.6.2 Using non-Microsoft compilers on Windows ----------------------------------------------- * Menu: * Borland/CodeGear C++:: * GNU C / Cygwin / MinGW::  File: python.info, Node: Borland/CodeGear C++, Next: GNU C / Cygwin / MinGW, Up: Using non-Microsoft compilers on Windows 18.6.2.1 Borland/CodeGear C++ ............................. This subsection describes the necessary steps to use Distutils with the Borland C++ compiler version 5.5. First you have to know that Borland’s object file format (OMF) is different from the format used by the Python version you can download from the Python or ActiveState Web site. (Python is built with Microsoft Visual C++, which uses COFF as the object file format.) For this reason you have to convert Python’s library ‘python25.lib’ into the Borland format. You can do this as follows: coff2omf python25.lib python25_bcpp.lib The ‘coff2omf’ program comes with the Borland compiler. The file ‘python25.lib’ is in the ‘Libs’ directory of your Python installation. If your extension uses other libraries (zlib, …) you have to convert them too. The converted files have to reside in the same directories as the normal libraries. How does Distutils manage to use these libraries with their changed names? If the extension needs a library (eg. ‘foo’) Distutils checks first if it finds a library with suffix ‘_bcpp’ (eg. ‘foo_bcpp.lib’) and then uses this library. In the case it doesn’t find such a special library it uses the default name (‘foo.lib’.) (1) To let Distutils compile your extension with Borland C++ you now have to type: python setup.py build --compiler=bcpp If you want to use the Borland C++ compiler as the default, you could specify this in your personal or system-wide configuration file for Distutils (see section *note Distutils Configuration Files: 41b6.) See also ........ C++Builder Compiler(2) Information about the free C++ compiler from Borland, including links to the download pages. Creating Python Extensions Using Borland’s Free Compiler(3) Document describing how to use Borland’s free command-line C++ compiler to build Python. ---------- Footnotes ---------- (1) (1) This also means you could replace all existing COFF-libraries with OMF-libraries of the same name. (2) https://www.embarcadero.com/products (3) http://www.cyberus.ca/~g_will/pyExtenDL.shtml  File: python.info, Node: GNU C / Cygwin / MinGW, Prev: Borland/CodeGear C++, Up: Using non-Microsoft compilers on Windows 18.6.2.2 GNU C / Cygwin / MinGW ............................... This section describes the necessary steps to use Distutils with the GNU C/C++ compilers in their Cygwin and MinGW distributions. (1) For a Python interpreter that was built with Cygwin, everything should work without any of these following steps. Not all extensions can be built with MinGW or Cygwin, but many can. Extensions most likely to not work are those that use C++ or depend on Microsoft Visual C extensions. To let Distutils compile your extension with Cygwin you have to type: python setup.py build --compiler=cygwin and for Cygwin in no-cygwin mode (2) or for MinGW type: python setup.py build --compiler=mingw32 If you want to use any of these options/compilers as default, you should consider writing it in your personal or system-wide configuration file for Distutils (see section *note Distutils Configuration Files: 41b6.) * Menu: * Older Versions of Python and MinGW:: ---------- Footnotes ---------- (1) (2) Check ‘https://www.sourceware.org/cygwin/’ for more information (2) (3) Then you have no POSIX emulation available, but you also don’t need ‘cygwin1.dll’.  File: python.info, Node: Older Versions of Python and MinGW, Up: GNU C / Cygwin / MinGW 18.6.2.3 Older Versions of Python and MinGW ........................................... The following instructions only apply if you’re using a version of Python inferior to 2.4.1 with a MinGW inferior to 3.0.0 (with binutils-2.13.90-20030111-1). These compilers require some special libraries. This task is more complex than for Borland’s C++, because there is no program to convert the library. First you have to create a list of symbols which the Python DLL exports. (You can find a good program for this task at ‘https://sourceforge.net/projects/mingw/files/MinGW/Extension/pexports/’). pexports python25.dll >python25.def The location of an installed ‘python25.dll’ will depend on the installation options and the version and language of Windows. In a “just for me” installation, it will appear in the root of the installation directory. In a shared installation, it will be located in the system directory. Then you can create from these information an import library for gcc. /cygwin/bin/dlltool --dllname python25.dll --def python25.def --output-lib libpython25.a The resulting library has to be placed in the same directory as ‘python25.lib’. (Should be the ‘libs’ directory under your Python installation directory.) If your extension uses other libraries (zlib,…) you might have to convert them too. The converted files have to reside in the same directories as the normal libraries do. See also ........ Building Python modules on MS Windows platform with MinGW(1) Information about building the required libraries for the MinGW environment. ---------- Footnotes ---------- (1) http://old.zope.org/Members/als/tips/win32_mingw_modules  File: python.info, Node: Python Module Index, Next: Index, Prev: Installing Python Modules Legacy version, Up: Top Python Module Index ******************* * Menu: * __future__: 0. Future statement definitions * __main__: 1. The environment where the top-level script is run. * _dummy_thread: 2. Drop-in replacement for the _thread module. * _thread: 3. Low-level threading API. * abc: 4. Abstract base classes according to :pep:‘3119‘. * aifc: 5. Read and write audio files in AIFF or AIFC format. * argparse: 6. Command-line option and argument parsing library. * array: 7. Space efficient arrays of uniformly typed numeric values. * ast: 8. Abstract Syntax Tree classes and manipulation. * asynchat: 9. Support for asynchronous command/response protocols. * asyncio: a. Asynchronous I/O. * asyncore: b. A base class for developing asynchronous socket handling services. * atexit: c. Register and execute cleanup functions. * audioop: d. Manipulate raw audio data. * base64: e. RFC 3548: Base16, Base32, Base64 Data Encodings; Base85 and Ascii85 * bdb: f. Debugger framework. * binascii: 10. Tools for converting between binary and various ASCII- encoded binary representations. * binhex: 11. Encode and decode files in binhex4 format. * bisect: 12. Array bisection algorithms for binary searching. * builtins: 13. The module that provides the built-in namespace. * bz2: 14. Interfaces for bzip2 compression and decompression. * calendar: 15. Functions for working with calendars, including some emulation of the Unix cal program. * cgi: 16. Helpers for running Python scripts via the Common Gateway Interface. * cgitb: 17. Configurable traceback handler for CGI scripts. * chunk: 18. Module to read IFF chunks. * cmath: 19. Mathematical functions for complex numbers. * cmd: 1a. Build line-oriented command interpreters. * code: 1b. Facilities to implement read-eval-print loops. * codecs: 1c. Encode and decode data and streams. * codeop: 1d. Compile (possibly incomplete) Python code. * collections: 1e. Container datatypes * collections.abc: 1f. Abstract base classes for containers * colorsys: 20. Conversion functions between RGB and other color systems. * compileall: 21. Tools for byte-compiling all Python source files in a directory tree. * concurrent.futures: 22. Execute computations concurrently using threads or processes. * configparser: 23. Configuration file parser. * contextlib: 24. Utilities for with-statement contexts. * contextvars: 25. Context Variables * copy: 26. Shallow and deep copy operations. * copyreg: 27. Register pickle support functions. * cProfile: 28. * crypt: 29. The crypt() function used to check Unix passwords. * csv: 2a. Write and read tabular data to and from delimited files. * ctypes: 2b. A foreign function library for Python. * curses: 2c. An interface to the curses library, providing portable terminal handling. * curses.ascii: 2d. Constants and set-membership functions for ASCII characters. * curses.panel: 2e. A panel stack extension that adds depth to curses windows. * curses.textpad: 2f. Emacs-like input editing in a curses window. * dataclasses: 30. Generate special methods on user-defined classes. * datetime: 31. Basic date and time types. * dbm: 32. Interfaces to various Unix "database" formats. * dbm.dumb: 33. Portable implementation of the simple DBM interface. * dbm.gnu: 34. GNU’s reinterpretation of dbm. * dbm.ndbm: 35. The standard "database" interface, based on ndbm. * decimal: 36. Implementation of the General Decimal Arithmetic Specification. * difflib: 37. Helpers for computing differences between objects. * dis: 38. Disassembler for Python bytecode. * distutils: 39. Support for building and installing Python modules into an existing Python installation. * distutils.archive_util: 3a. Utility functions for creating archive files (tarballs, zip files, ...) * distutils.bcppcompiler: 3b. * distutils.ccompiler: 3c. Abstract CCompiler class * distutils.cmd: 3d. Provides the abstract base class :class:‘~distutils.cmd.Command‘. This class is subclassed by the modules in the distutils.command subpackage. * distutils.command: 3e. Contains one module for each standard Distutils command. * distutils.command.bdist: 3f. Build a binary installer for a package * distutils.command.bdist_dumb: 40. Build a "dumb" installer - a simple archive of files * distutils.command.bdist_msi: 41. Build a binary distribution as a Windows MSI file * distutils.command.bdist_packager: 42. Abstract base class for packagers * distutils.command.bdist_rpm: 43. Build a binary distribution as a Redhat RPM and SRPM * distutils.command.bdist_wininst: 44. Build a Windows installer * distutils.command.build: 45. Build all files of a package * distutils.command.build_clib: 46. Build any C libraries in a package * distutils.command.build_ext: 47. Build any extensions in a package * distutils.command.build_py: 48. Build the .py/.pyc files of a package * distutils.command.build_scripts: 49. Build the scripts of a package * distutils.command.check: 4a. Check the meta-data of a package * distutils.command.clean: 4b. Clean a package build area * distutils.command.config: 4c. Perform package configuration * distutils.command.install: 4d. Install a package * distutils.command.install_data: 4e. Install data files from a package * distutils.command.install_headers: 4f. Install C/C++ header files from a package * distutils.command.install_lib: 50. Install library files from a package * distutils.command.install_scripts: 51. Install script files from a package * distutils.command.register: 52. Register a module with the Python Package Index * distutils.command.sdist: 53. Build a source distribution * distutils.core: 54. The core Distutils functionality * distutils.cygwinccompiler: 55. * distutils.debug: 56. Provides the debug flag for distutils * distutils.dep_util: 57. Utility functions for simple dependency checking * distutils.dir_util: 58. Utility functions for operating on directories and directory trees * distutils.dist: 59. Provides the Distribution class, which represents the module distribution being built/installed/distributed * distutils.errors: 5a. Provides standard distutils exceptions * distutils.extension: 5b. Provides the Extension class, used to describe C/C++ extension modules in setup scripts * distutils.fancy_getopt: 5c. Additional getopt functionality * distutils.file_util: 5d. Utility functions for operating on single files * distutils.filelist: 5e. The FileList class, used for poking about the file system and building lists of files. * distutils.log: 5f. A simple logging mechanism, :pep:‘282‘-style * distutils.msvccompiler: 60. Microsoft Compiler * distutils.spawn: 61. Provides the spawn() function * distutils.sysconfig: 62. Low-level access to configuration information of the Python interpreter. * distutils.text_file: 63. Provides the TextFile class, a simple interface to text files * distutils.unixccompiler: 64. UNIX C Compiler * distutils.util: 65. Miscellaneous other utility functions * distutils.version: 66. Implements classes that represent module version numbers. * doctest: 67. Test pieces of code within docstrings. * dummy_threading: 68. Drop-in replacement for the threading module. * email: 69. Package supporting the parsing, manipulating, and generating email messages. * email.charset: 6a. Character Sets * email.contentmanager: 6b. Storing and Retrieving Content from MIME Parts * email.encoders: 6c. Encoders for email message payloads. * email.errors: 6d. The exception classes used by the email package. * email.generator: 6e. Generate flat text email messages from a message structure. * email.header: 6f. Representing non-ASCII headers * email.headerregistry: 70. Automatic Parsing of headers based on the field name * email.iterators: 71. Iterate over a message object tree. * email.message: 72. The base class representing email messages. * email.mime: 73. Build MIME messages. * email.parser: 74. Parse flat text email messages to produce a message object structure. * email.policy: 75. Controlling the parsing and generating of messages * email.utils: 76. Miscellaneous email package utilities. * encodings.idna: 77. Internationalized Domain Names implementation * encodings.mbcs: 78. Windows ANSI codepage * encodings.utf_8_sig: 79. UTF-8 codec with BOM signature * ensurepip: 7a. Bootstrapping the "pip" installer into an existing Python installation or virtual environment. * enum: 7b. Implementation of an enumeration class. * errno: 7c. Standard errno system symbols. * faulthandler: 7d. Dump the Python traceback. * fcntl: 7e. The fcntl() and ioctl() system calls. * filecmp: 7f. Compare files efficiently. * fileinput: 80. Loop over standard input or a list of files. * fnmatch: 81. Unix shell style filename pattern matching. * formatter: 82. Generic output formatter and device interface. * fractions: 83. Rational numbers. * ftplib: 84. FTP protocol client (requires sockets). * functools: 85. Higher-order functions and operations on callable objects. * gc: 86. Interface to the cycle-detecting garbage collector. * getopt: 87. Portable parser for command line options; support both short and long option names. * getpass: 88. Portable reading of passwords and retrieval of the userid. * gettext: 89. Multilingual internationalization services. * glob: 8a. Unix shell style pathname pattern expansion. * grp: 8b. The group database (getgrnam() and friends). * gzip: 8c. Interfaces for gzip compression and decompression using file objects. * hashlib: 8d. Secure hash and message digest algorithms. * heapq: 8e. Heap queue algorithm (a.k.a. priority queue). * hmac: 8f. Keyed-Hashing for Message Authentication (HMAC) implementation * html: 90. Helpers for manipulating HTML. * html.entities: 91. Definitions of HTML general entities. * html.parser: 92. A simple parser that can handle HTML and XHTML. * http: 93. HTTP status codes and messages * http.client: 94. HTTP and HTTPS protocol client (requires sockets). * http.cookiejar: 95. Classes for automatic handling of HTTP cookies. * http.cookies: 96. Support for HTTP state management (cookies). * http.server: 97. HTTP server and request handlers. * imaplib: 98. IMAP4 protocol client (requires sockets). * imghdr: 99. Determine the type of image contained in a file or byte stream. * imp: 9a. Access the implementation of the import statement. * importlib: 9b. The implementation of the import machinery. * importlib.abc: 9c. Abstract base classes related to import * importlib.machinery: 9d. Importers and path hooks * importlib.resources: 9e. Package resource reading, opening, and access * importlib.util: 9f. Utility code for importers * inspect: a0. Extract information and source code from live objects. * io: a1. Core tools for working with streams. * ipaddress: a2. IPv4/IPv6 manipulation library. * itertools: a3. Functions creating iterators for efficient looping. * json: a4. Encode and decode the JSON format. * json.tool: a5. A command line to validate and pretty-print JSON. * keyword: a6. Test whether a string is a keyword in Python. * lib2to3: a7. The 2to3 library * linecache: a8. Provides random access to individual lines from text files. * locale: a9. Internationalization services. * logging: aa. Flexible event logging system for applications. * logging.config: ab. Configuration of the logging module. * logging.handlers: ac. Handlers for the logging module. * lzma: ad. A Python wrapper for the liblzma compression library. * mailbox: ae. Manipulate mailboxes in various formats * mailcap: af. Mailcap file handling. * marshal: b0. Convert Python objects to streams of bytes and back (with different constraints). * math: b1. Mathematical functions (sin() etc.). * mimetypes: b2. Mapping of filename extensions to MIME types. * mmap: b3. Interface to memory-mapped files for Unix and Windows. * modulefinder: b4. Find modules used by a script. * msilib: b5. Creation of Microsoft Installer files, and CAB files. * msvcrt: b6. Miscellaneous useful routines from the MS VC++ runtime. * multiprocessing: b7. Process-based parallelism. * multiprocessing.connection: b8. API for dealing with sockets. * multiprocessing.dummy: b9. Dumb wrapper around threading. * multiprocessing.managers: ba. Share data between process with shared objects. * multiprocessing.pool: bb. Create pools of processes. * multiprocessing.shared_memory: bc. Provides shared memory for direct access across processes. * multiprocessing.sharedctypes: bd. Allocate ctypes objects from shared memory. * netrc: be. Loading of .netrc files. * nis: bf. Interface to Sun’s NIS (Yellow Pages) library. * nntplib: c0. NNTP protocol client (requires sockets). * numbers: c1. Numeric abstract base classes (Complex, Real, Integral, etc.). * operator: c2. Functions corresponding to the standard operators. * optparse: c3. Command-line option parsing library. * os: c4. Miscellaneous operating system interfaces. * os.path: c5. Operations on pathnames. * ossaudiodev: c6. Access to OSS-compatible audio devices. * parser: c7. Access parse trees for Python source code. * pathlib: c8. Object-oriented filesystem paths * pdb: c9. The Python debugger for interactive interpreters. * pickle: ca. Convert Python objects to streams of bytes and back. * pickletools: cb. Contains extensive comments about the pickle protocols and pickle-machine opcodes, as well as some useful functions. * pipes: cc. A Python interface to Unix shell pipelines. * pkgutil: cd. Utilities for the import system. * platform: ce. Retrieves as much platform identifying data as possible. * plistlib: cf. Generate and parse Mac OS X plist files. * poplib: d0. POP3 protocol client (requires sockets). * posix: d1. The most common POSIX system calls (normally used via module os). * pprint: d2. Data pretty printer. * profile: d3. Python source profiler. * pstats: d4. Statistics object for use with the profiler. * pty: d5. Pseudo-Terminal Handling for Linux. * pwd: d6. The password database (getpwnam() and friends). * py_compile: d7. Generate byte-code files from Python source files. * pyclbr: d8. Supports information extraction for a Python module browser. * pydoc: d9. Documentation generator and online help system. * queue: da. A synchronized queue class. * quopri: db. Encode and decode files using the MIME quoted- printable encoding. * random: dc. Generate pseudo-random numbers with various common distributions. * re: dd. Regular expression operations. * readline: de. GNU readline support for Python. * reprlib: df. Alternate repr() implementation with size limits. * resource: e0. An interface to provide resource usage information on the current process. * rlcompleter: e1. Python identifier completion, suitable for the GNU readline library. * runpy: e2. Locate and run Python modules without importing them first. * sched: e3. General purpose event scheduler. * secrets: e4. Generate secure random numbers for managing secrets. * select: e5. Wait for I/O completion on multiple streams. * selectors: e6. High-level I/O multiplexing. * shelve: e7. Python object persistence. * shlex: e8. Simple lexical analysis for Unix shell-like languages. * shutil: e9. High-level file operations, including copying. * signal: ea. Set handlers for asynchronous events. * site: eb. Module responsible for site-specific configuration. * smtpd: ec. A SMTP server implementation in Python. * smtplib: ed. SMTP protocol client (requires sockets). * sndhdr: ee. Determine type of a sound file. * socket: ef. Low-level networking interface. * socketserver: f0. A framework for network servers. * spwd: f1. The shadow password database (getspnam() and friends). * sqlite3: f2. A DB-API 2.0 implementation using SQLite 3.x. * ssl: f3. TLS/SSL wrapper for socket objects * stat: f4. Utilities for interpreting the results of os.stat(), os.lstat() and os.fstat(). * statistics: f5. Mathematical statistics functions * string: f6. Common string operations. * stringprep: f7. String preparation, as per RFC 3453 * struct: f8. Interpret bytes as packed binary data. * subprocess: f9. Subprocess management. * sunau: fa. Provide an interface to the Sun AU sound format. * symbol: fb. Constants representing internal nodes of the parse tree. * symtable: fc. Interface to the compiler’s internal symbol tables. * sys: fd. Access system-specific parameters and functions. * sysconfig: fe. Python’s configuration information * syslog: ff. An interface to the Unix syslog library routines. * tabnanny: 100. Tool for detecting white space related problems in Python source files in a directory tree. * tarfile: 101. Read and write tar-format archive files. * telnetlib: 102. Telnet client class. * tempfile: 103. Generate temporary files and directories. * termios: 104. POSIX style tty control. * test: 105. Regression tests package containing the testing suite for Python. * test.support: 106. Support for Python’s regression test suite. * test.support.script_helper: 107. Support for Python’s script execution tests. * textwrap: 108. Text wrapping and filling * threading: 109. Thread-based parallelism. * time: 10a. Time access and conversions. * timeit: 10b. Measure the execution time of small code snippets. * tkinter: 10c. Interface to Tcl/Tk for graphical user interfaces * tkinter.scrolledtext: 10d. Text widget with a vertical scroll bar. * tkinter.tix: 10e. Tk Extension Widgets for Tkinter * tkinter.ttk: 10f. Tk themed widget set * token: 110. Constants representing terminal nodes of the parse tree. * tokenize: 111. Lexical scanner for Python source code. * trace: 112. Trace or track Python statement execution. * traceback: 113. Print or retrieve a stack traceback. * tracemalloc: 114. Trace memory allocations. * tty: 115. Utility functions that perform common terminal control operations. * turtle: 116. An educational framework for simple graphics applications * turtledemo: 117. A viewer for example turtle scripts * types: 118. Names for built-in types. * typing: 119. Support for type hints (see :pep:‘484‘). * unicodedata: 11a. Access the Unicode Database. * unittest: 11b. Unit testing framework for Python. * unittest.mock: 11c. Mock object library. * urllib: 11d. * urllib.error: 11e. Exception classes raised by urllib.request. * urllib.parse: 11f. Parse URLs into or assemble them from components. * urllib.request: 120. Extensible library for opening URLs. * urllib.response: 121. Response classes used by urllib. * urllib.robotparser: 122. Load a robots.txt file and answer questions about fetchability of other URLs. * uu: 123. Encode and decode files in uuencode format. * uuid: 124. UUID objects (universally unique identifiers) according to RFC 4122 * venv: 125. Creation of virtual environments. * warnings: 126. Issue warning messages and control their disposition. * wave: 127. Provide an interface to the WAV sound format. * weakref: 128. Support for weak references and weak dictionaries. * webbrowser: 129. Easy-to-use controller for Web browsers. * winreg: 12a. Routines and objects for manipulating the Windows registry. * winsound: 12b. Access to the sound-playing machinery for Windows. * wsgiref: 12c. WSGI Utilities and Reference Implementation. * wsgiref.handlers: 12d. WSGI server/gateway base classes. * wsgiref.headers: 12e. WSGI response header tools. * wsgiref.simple_server: 12f. A simple WSGI HTTP server. * wsgiref.util: 130. WSGI environment utilities. * wsgiref.validate: 131. WSGI conformance checker. * xdrlib: 132. Encoders and decoders for the External Data Representation (XDR). * xml: 133. Package containing XML processing modules * xml.dom: 134. Document Object Model API for Python. * xml.dom.minidom: 135. Minimal Document Object Model (DOM) implementation. * xml.dom.pulldom: 136. Support for building partial DOM trees from SAX events. * xml.etree.ElementTree: 137. Implementation of the ElementTree API. * xml.parsers.expat: 138. An interface to the Expat non-validating XML parser. * xml.parsers.expat.errors: 139. * xml.parsers.expat.model: 13a. * xml.sax: 13b. Package containing SAX2 base classes and convenience functions. * xml.sax.handler: 13c. Base classes for SAX event handlers. * xml.sax.saxutils: 13d. Convenience functions and classes for use with SAX. * xml.sax.xmlreader: 13e. Interface which SAX-compliant XML parsers must implement. * xmlrpc.client: 13f. XML-RPC client access. * xmlrpc.server: 140. Basic XML-RPC server implementations. * zipapp: 141. Manage executable Python zip archives * zipfile: 142. Read and write ZIP-format archive files. * zipimport: 143. Support for importing Python modules from ZIP archives. * zlib: 144. Low-level interface to compression and decompression routines compatible with gzip.  File: python.info, Node: Index, Prev: Python Module Index, Up: Top Index ***** [index] * Menu: * ! (exclamation); in a command interpreter: Cmd Objects. (line 27) * ! (exclamation); in curses module: curses ascii — Utilities for ASCII characters. (line 226) * ! (exclamation); in formatted string literal: String literal concatenation. (line 24) * ! (exclamation); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * ! (exclamation); in glob-style wildcards <1>: fnmatch — Unix filename pattern matching. (line 15) * ! (exclamation); in string formatting: Format String Syntax. (line 13) * ! (exclamation); in struct format strings: Byte Order Size and Alignment. (line 10) * ! (pdb command): Debugger Commands. (line 311) * " (double quote); string literal: Literals. (line 8) * """; string literal: String and Bytes literals. (line 36) * # (hash); comment: An Informal Introduction to Python. (line 14) * # (hash); comment <1>: Comments. (line 6) * # (hash); comment <2>: site — Site-specific configuration hook. (line 45) * # (hash); in doctests: Option Flags. (line 183) * # (hash); in printf-style formatting: printf-style String Formatting. (line 66) * # (hash); in printf-style formatting <1>: printf-style Bytes Formatting. (line 63) * # (hash); in regular expressions: Module Contents. (line 123) * # (hash); in string formatting: Format Specification Mini-Language. (line 87) * # (hash); source encoding declaration: Encoding declarations. (line 6) * $ (dollar); environment variables expansion: os path — Common pathname manipulations. (line 158) * $ (dollar); in regular expressions: Regular Expression Syntax. (line 57) * $ (dollar); in template strings: Template strings. (line 13) * $ (dollar); interpolation in configuration files: Interpolation of values. (line 40) * % (percent); datetime format: timezone Objects. (line 71) * % (percent); datetime format <1>: Functions<2>. (line 230) * % (percent); datetime format <2>: Functions<2>. (line 362) * % (percent); environment variables expansion (Windows): os path — Common pathname manipulations. (line 158) * % (percent); environment variables expansion (Windows) <1>: Functions<11>. (line 233) * % (percent); interpolation in configuration files: Interpolation of values. (line 10) * % (percent); printf-style formatting: printf-style String Formatting. (line 6) * % (percent); printf-style formatting <1>: printf-style Bytes Formatting. (line 6) * %=; augmented assignment: Augmented assignment statements. (line 6) * &=; augmented assignment: Augmented assignment statements. (line 6) * ’ (single quote); string literal: Literals. (line 8) * ’’’; string literal: String and Bytes literals. (line 36) * () (parentheses); call: Slicings. (line 38) * () (parentheses); class definition: Class definitions. (line 6) * () (parentheses); function definition: Function definitions. (line 6) * () (parentheses); generator expression: Generator expressions. (line 6) * () (parentheses); in assignment target list: Assignment statements. (line 35) * () (parentheses); in printf-style formatting: printf-style String Formatting. (line 26) * () (parentheses); in printf-style formatting <1>: printf-style Bytes Formatting. (line 23) * () (parentheses); in regular expressions: Regular Expression Syntax. (line 199) * () (parentheses); tuple display: Parenthesized forms. (line 6) * (?!; in regular expressions: Regular Expression Syntax. (line 316) * (?#; in regular expressions: Regular Expression Syntax. (line 305) * (?; in regular expressions: Regular Expression Syntax. (line 208) * (?;; in regular expressions: Regular Expression Syntax. (line 232) * (?: Calls. (line 74) * * (asterisk); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * * (asterisk); in glob-style wildcards <1>: fnmatch — Unix filename pattern matching. (line 15) * * (asterisk); in printf-style formatting: printf-style String Formatting. (line 26) * * (asterisk); in printf-style formatting <1>: printf-style Bytes Formatting. (line 23) * * (asterisk); in regular expressions: Regular Expression Syntax. (line 68) * **; function definition: Function definitions. (line 78) * **; in dictionary displays: Dictionary displays. (line 23) * **; in function calls: Unpacking Argument Lists. (line 19) * **; in function calls <1>: Calls. (line 100) * **; in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 41) * **=; augmented assignment: Augmented assignment statements. (line 6) * *=; augmented assignment: Augmented assignment statements. (line 6) * *?; in regular expressions: Regular Expression Syntax. (line 85) * + (plus); binary operator: Binary arithmetic operations. (line 60) * + (plus); binary operator <1>: Numeric Types — int float complex. (line 27) * + (plus); in argparse module: nargs. (line 68) * + (plus); in doctests: Option Flags. (line 183) * + (plus); in printf-style formatting: printf-style String Formatting. (line 66) * + (plus); in printf-style formatting <1>: printf-style Bytes Formatting. (line 63) * + (plus); in regular expressions: Regular Expression Syntax. (line 74) * + (plus); in string formatting: Format Specification Mini-Language. (line 71) * + (plus); unary operator: Unary arithmetic and bitwise operations. (line 13) * + (plus); unary operator <1>: Numeric Types — int float complex. (line 27) * +=; augmented assignment: Augmented assignment statements. (line 6) * +?; in regular expressions: Regular Expression Syntax. (line 85) * , (comma): Parenthesized forms. (line 20) * , (comma); argument list: Slicings. (line 38) * , (comma); expression list: List displays. (line 6) * , (comma); expression list <1>: Set displays. (line 6) * , (comma); expression list <2>: Expression lists. (line 6) * , (comma); expression list <3>: The assert statement. (line 6) * , (comma); expression list <4>: Class definitions. (line 6) * , (comma); identifier list: The global statement. (line 6) * , (comma); identifier list <1>: The nonlocal statement. (line 6) * , (comma); import statement: The import statement. (line 6) * , (comma); in dictionary displays: Dictionary displays. (line 6) * , (comma); in string formatting: Format Specification Mini-Language. (line 99) * , (comma); in target list: Assignment statements. (line 35) * , (comma); parameter list: Function definitions. (line 6) * , (comma); slicing: Slicings. (line 6) * , (comma); with statement: The with statement. (line 6) * - (minus); binary operator: Binary arithmetic operations. (line 66) * - (minus); binary operator <1>: Numeric Types — int float complex. (line 27) * - (minus); in doctests: Option Flags. (line 182) * - (minus); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * - (minus); in glob-style wildcards <1>: fnmatch — Unix filename pattern matching. (line 15) * - (minus); in printf-style formatting: printf-style String Formatting. (line 66) * - (minus); in printf-style formatting <1>: printf-style Bytes Formatting. (line 63) * - (minus); in regular expressions: Regular Expression Syntax. (line 143) * - (minus); in string formatting: Format Specification Mini-Language. (line 71) * - (minus); unary operator: Unary arithmetic and bitwise operations. (line 10) * - (minus); unary operator <1>: Numeric Types — int float complex. (line 27) * -=; augmented assignment: Augmented assignment statements. (line 6) * ->; function annotations: Function Annotations. (line 6) * ->; function annotations <1>: Function definitions. (line 89) * . (dot); attribute reference: Attribute references. (line 6) * . (dot); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * . (dot); in numeric literal: Integer literals. (line 40) * . (dot); in pathnames: Miscellaneous System Information. (line 81) * . (dot); in pathnames <1>: Miscellaneous System Information. (line 109) * . (dot); in printf-style formatting: printf-style String Formatting. (line 26) * . (dot); in printf-style formatting <1>: printf-style Bytes Formatting. (line 23) * . (dot); in regular expressions: Regular Expression Syntax. (line 46) * . (dot); in string formatting: Format String Syntax. (line 13) * . (dot); in Tkinter: A Very Quick Look at Tcl/Tk. (line 44) * ...: Glossary. (line 10) * ...; ellipsis literal: The standard type hierarchy. (line 41) * ...; ellipsis literal <1>: Built-in Constants. (line 52) * ...; ellipsis literal <2>: The Null Object. (line 12) * ...; in doctests: Option Flags. (line 49) * ...; interpreter prompt: How are Docstring Examples Recognized?. (line 26) * ...; interpreter prompt <1>: sys — System-specific parameters and functions. (line 1188) * ...; placeholder: textwrap — Text wrapping and filling. (line 266) * ...; placeholder <1>: pprint — Data pretty printer. (line 27) * ...; placeholder <2>: reprlib — Alternate repr implementation. (line 41) * ..; in pathnames: Miscellaneous System Information. (line 87) * .ini; file: configparser — Configuration file parser. (line 8) * .pdbrc; file: Debugger Commands. (line 37) * / (slash); in pathnames: Miscellaneous System Information. (line 93) * / (slash); in pathnames <1>: Miscellaneous System Information. (line 102) * //=; augmented assignment: Augmented assignment statements. (line 6) * /=; augmented assignment: Augmented assignment statements. (line 6) * 0b; integer literal: Numeric literals. (line 14) * 0o; integer literal: Numeric literals. (line 14) * 0x; integer literal: Numeric literals. (line 14) * 2-digit years: time — Time access and conversions. (line 35) * 2to3: Glossary. (line 23) * ; (colon); annotated variable: Annotated assignment statements. (line 6) * ; (colon); compound statement: The if statement. (line 6) * ; (colon); compound statement <1>: The while statement. (line 6) * ; (colon); compound statement <2>: The for statement. (line 6) * ; (colon); compound statement <3>: The try statement. (line 6) * ; (colon); compound statement <4>: The with statement. (line 6) * ; (colon); compound statement <5>: Function definitions. (line 6) * ; (colon); compound statement <6>: Class definitions. (line 6) * ; (colon); function annotations: Function Annotations. (line 6) * ; (colon); function annotations <1>: Function definitions. (line 89) * ; (colon); in dictionary expressions: Dictionary displays. (line 6) * ; (colon); in formatted string literal: String literal concatenation. (line 24) * ; (colon); in SQL statements: Cursor Objects. (line 11) * ; (colon); in string formatting: Format String Syntax. (line 13) * ; (colon); lambda expression: Lambdas. (line 6) * ; (colon); path separator (POSIX): Miscellaneous System Information. (line 115) * ; (colon); slicing: Slicings. (line 6) * ; (semicolon): Compound statements. (line 18) * ; (semicolon) <1>: Miscellaneous System Information. (line 115) * < (less); in string formatting: Format Specification Mini-Language. (line 42) * < (less); in struct format strings: Byte Order Size and Alignment. (line 10) * <<=; augmented assignment: Augmented assignment statements. (line 6) * : Option Flags. (line 30) * = (equals); assignment statement: Assignment statements. (line 6) * = (equals); class definition: Metaclasses. (line 6) * = (equals); for help in debugging using string literals: String literal concatenation. (line 23) * = (equals); function definition: Function definitions. (line 53) * = (equals); in function calls: Slicings. (line 37) * = (equals); in string formatting: Format Specification Mini-Language. (line 42) * = (equals); in struct format strings: Byte Order Size and Alignment. (line 10) * > (greater); in string formatting: Format Specification Mini-Language. (line 42) * > (greater); in struct format strings: Byte Order Size and Alignment. (line 10) * >>=; augmented assignment: Augmented assignment statements. (line 6) * >>>: Glossary. (line 6) * >>>; interpreter prompt: How are Docstring Examples Recognized?. (line 26) * >>>; interpreter prompt <1>: sys — System-specific parameters and functions. (line 1188) * ? (question mark); in a command interpreter: Cmd Objects. (line 27) * ? (question mark); in argparse module: nargs. (line 23) * ? (question mark); in AST grammar: Node classes. (line 22) * ? (question mark); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * ? (question mark); in glob-style wildcards <1>: fnmatch — Unix filename pattern matching. (line 15) * ? (question mark); in regular expressions: Regular Expression Syntax. (line 80) * ? (question mark); in SQL statements: Cursor Objects. (line 11) * ? (question mark); in struct format strings: Format Characters. (line 86) * ? (question mark); in struct format strings <1>: Format Characters. (line 161) * ? (question mark); replacement character: Error Handlers. (line 28) * ??; in regular expressions: Regular Expression Syntax. (line 85) * @ (at); class definition: Class definitions. (line 44) * @ (at); function definition: Function definitions. (line 33) * @ (at); in struct format strings: Byte Order Size and Alignment. (line 10) * [] (square brackets); in assignment target list: Assignment statements. (line 35) * [] (square brackets); in glob-style wildcards: glob — Unix style pathname pattern expansion. (line 10) * [] (square brackets); in glob-style wildcards <1>: fnmatch — Unix filename pattern matching. (line 15) * [] (square brackets); in regular expressions: Regular Expression Syntax. (line 136) * [] (square brackets); in string formatting: Format String Syntax. (line 13) * [] (square brackets); list expression: List displays. (line 6) * [] (square brackets); subscription: Subscriptions. (line 6) * \ (backslash); escape sequence: String and Bytes literals. (line 72) * \ (backslash); escape sequence <1>: Error Handlers. (line 28) * \ (backslash); in pathnames (Windows): Miscellaneous System Information. (line 93) * \ (backslash); in regular expressions: Regular Expression Syntax. (line 121) * \ (backslash); in regular expressions <1>: Regular Expression Syntax. (line 155) * \ (backslash); in regular expressions <2>: Regular Expression Syntax. (line 374) * \a; escape sequence: String and Bytes literals. (line 72) * \A; in regular expressions: Regular Expression Syntax. (line 386) * \a; in regular expressions: Regular Expression Syntax. (line 486) * \b; escape sequence: String and Bytes literals. (line 72) * \b; in regular expressions: Regular Expression Syntax. (line 390) * \B; in regular expressions: Regular Expression Syntax. (line 407) * \b; in regular expressions <1>: Regular Expression Syntax. (line 486) * \d; in regular expressions: Regular Expression Syntax. (line 418) * \D; in regular expressions: Regular Expression Syntax. (line 431) * \f; escape sequence: String and Bytes literals. (line 72) * \f; in regular expressions: Regular Expression Syntax. (line 486) * \g; in regular expressions: Module Contents. (line 282) * \n; escape sequence: String and Bytes literals. (line 72) * \N; escape sequence: String and Bytes literals. (line 72) * \N; escape sequence <1>: Error Handlers. (line 28) * \n; in regular expressions: Regular Expression Syntax. (line 486) * \N; in regular expressions: Regular Expression Syntax. (line 486) * \r; escape sequence: String and Bytes literals. (line 72) * \r; in regular expressions: Regular Expression Syntax. (line 486) * \s; in regular expressions: Regular Expression Syntax. (line 437) * \S; in regular expressions: Regular Expression Syntax. (line 452) * \t; escape sequence: String and Bytes literals. (line 72) * \t; in regular expressions: Regular Expression Syntax. (line 486) * \u; escape sequence: String and Bytes literals. (line 72) * \U; escape sequence: String and Bytes literals. (line 72) * \u; escape sequence <1>: Error Handlers. (line 28) * \U; escape sequence <1>: Error Handlers. (line 28) * \u; in regular expressions: Regular Expression Syntax. (line 486) * \U; in regular expressions: Regular Expression Syntax. (line 486) * \v; escape sequence: String and Bytes literals. (line 72) * \v; in regular expressions: Regular Expression Syntax. (line 486) * \w; in regular expressions: Regular Expression Syntax. (line 458) * \W; in regular expressions: Regular Expression Syntax. (line 474) * \x; escape sequence: String and Bytes literals. (line 72) * \x; escape sequence <1>: Error Handlers. (line 28) * \x; in regular expressions: Regular Expression Syntax. (line 486) * \Z; in regular expressions: Regular Expression Syntax. (line 482) * \\; escape sequence: String and Bytes literals. (line 72) * \\; in regular expressions: Regular Expression Syntax. (line 486) * ^ (caret); in curses module: curses ascii — Utilities for ASCII characters. (line 226) * ^ (caret); in regular expressions: Regular Expression Syntax. (line 52) * ^ (caret); in regular expressions <1>: Regular Expression Syntax. (line 160) * ^ (caret); in string formatting: Format Specification Mini-Language. (line 42) * ^ (caret); marker: What About Exceptions?. (line 93) * ^ (caret); marker <1>: traceback — Print or retrieve a stack traceback. (line 46) * ^=; augmented assignment: Augmented assignment statements. (line 6) * _ (underscore); gettext: GNU gettext API. (line 42) * _ (underscore); in numeric literal: Numeric literals. (line 13) * _ (underscore); in numeric literal <1>: Integer literals. (line 39) * _ (underscore); in string formatting: Format Specification Mini-Language. (line 105) * _, identifiers: Keywords. (line 18) * _anonymous_ (ctypes.Structure attribute): Structured data types. (line 74) * _asdict() (collections.somenamedtuple method): namedtuple Factory Function for Tuples with Named Fields. (line 107) * _b_base_ (ctypes._CData attribute): Data types. (line 71) * _b_needsfree_ (ctypes._CData attribute): Data types. (line 78) * _callmethod() (multiprocessing.managers.BaseProxy method): Proxy Objects. (line 96) * _CData (class in ctypes): Data types. (line 6) * _clear_type_cache() (in module sys): sys — System-specific parameters and functions. (line 158) * _current_frames() (in module sys): sys — System-specific parameters and functions. (line 167) * _debugmallocstats() (in module sys): sys — System-specific parameters and functions. (line 224) * _dummy_thread (module): _dummy_thread — Drop-in replacement for the _thread module. (line 6) * _enablelegacywindowsfsencoding() (in module sys): sys — System-specific parameters and functions. (line 1449) * _exit() (in module os): Process Management. (line 120) * _fields (ast.AST attribute): Node classes. (line 22) * _fields (collections.somenamedtuple attribute): namedtuple Factory Function for Tuples with Named Fields. (line 137) * _fields_ (ctypes.Structure attribute): Structured data types. (line 31) * _field_defaults (collections.somenamedtuple attribute): namedtuple Factory Function for Tuples with Named Fields. (line 150) * _flush() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 116) * _frozen (C type): Importing Modules<2>. (line 260) * _FuncPtr (class in ctypes): Foreign functions. (line 12) * _getframe() (in module sys): sys — System-specific parameters and functions. (line 724) * _getvalue() (multiprocessing.managers.BaseProxy method): Proxy Objects. (line 138) * _get_child_mock() (unittest.mock.Mock method): The Mock Class. (line 286) * _handle (ctypes.PyDLL attribute): Loading shared libraries. (line 145) * _inittab (C type): Importing Modules<2>. (line 292) * _length_ (ctypes.Array attribute): Arrays and pointers. (line 18) * _make() (collections.somenamedtuple class method): namedtuple Factory Function for Tuples with Named Fields. (line 98) * _makeResult() (unittest.TextTestRunner method): Loading and running tests. (line 466) * _name (ctypes.PyDLL attribute): Loading shared libraries. (line 149) * _objects (ctypes._CData attribute): Data types. (line 83) * _pack_ (ctypes.Structure attribute): Structured data types. (line 67) * _parse() (gettext.NullTranslations method): The NullTranslations class. (line 21) * _Pointer (class in ctypes): Arrays and pointers. (line 31) * _PyBytes_Resize (C function): Bytes Objects<2>. (line 182) * _PyCFunctionFast (C type): Common Object Structures. (line 109) * _PyCFunctionFastWithKeywords (C type): Common Object Structures. (line 114) * _PyImport_Fini (C function): Importing Modules<2>. (line 238) * _PyImport_Init (C function): Importing Modules<2>. (line 230) * _PyObject_FastCallDict (C function): Object Protocol. (line 403) * _PyObject_New (C function): Allocating Objects on the Heap. (line 6) * _PyObject_NewVar (C function): Allocating Objects on the Heap. (line 9) * _PyObject_Vectorcall (C function): Object Protocol. (line 348) * _PyTuple_Resize (C function): Tuple Objects. (line 88) * _Py_c_diff (C function): Complex Numbers as C Structures. (line 27) * _Py_c_neg (C function): Complex Numbers as C Structures. (line 33) * _Py_c_pow (C function): Complex Numbers as C Structures. (line 53) * _Py_c_prod (C function): Complex Numbers as C Structures. (line 38) * _Py_c_quot (C function): Complex Numbers as C Structures. (line 44) * _Py_c_sum (C function): Complex Numbers as C Structures. (line 22) * _Py_InitializeMain (C function): Multi-Phase Initialization Private Provisional API. (line 44) * _Py_NoneStruct (C variable): Allocating Objects on the Heap. (line 59) * _Py_TPFLAGS_HAVE_VECTORCALL (built-in variable): PyTypeObject Slots. (line 628) * _replace() (collections.somenamedtuple method): namedtuple Factory Function for Tuples with Named Fields. (line 125) * _setroot() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 15) * _SimpleCData (class in ctypes): Fundamental data types<2>. (line 6) * _structure() (in module email.iterators): email iterators Iterators. (line 44) * _thread (module): _thread — Low-level threading API. (line 6) * _type_ (ctypes.Array attribute): Arrays and pointers. (line 24) * _type_ (ctypes._Pointer attribute): Arrays and pointers. (line 46) * _write() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 108) * _xoptions (in module sys): sys — System-specific parameters and functions. (line 1679) * __, identifiers: Keywords. (line 17) * __abs__() (in module operator): operator — Standard operators as functions. (line 73) * __abs__() (object method): Emulating numeric types. (line 111) * __add__() (in module operator): operator — Standard operators as functions. (line 78) * __add__() (object method): Emulating numeric types. (line 11) * __aenter__() (object method): Asynchronous Context Managers. (line 12) * __aexit__() (object method): Asynchronous Context Managers. (line 17) * __aiter__() (object method): Asynchronous Iterators. (line 12) * __all__: Importing * From a Package. (line 6) * __all__ (optional module attribute): The import statement. (line 83) * __all__ (package variable): Importing Modules<2>. (line 7) * __and__() (in module operator): operator — Standard operators as functions. (line 83) * __and__() (object method): Emulating numeric types. (line 11) * __anext__() (agen method): Asynchronous generator-iterator methods. (line 10) * __anext__() (object method): Asynchronous Iterators. (line 16) * __annotations__ (class attribute): The standard type hierarchy. (line 588) * __annotations__ (function attribute): The standard type hierarchy. (line 304) * __annotations__ (module attribute): The standard type hierarchy. (line 536) * __await__() (object method): Awaitable Objects. (line 15) * __bases__ (class attribute): The standard type hierarchy. (line 588) * __bases__ (class attribute) <1>: Special Attributes. (line 19) * __bool__() (object method): Basic customization. (line 302) * __bool__() (object method) <1>: Emulating container types. (line 39) * __breakpointhook__ (in module sys): sys — System-specific parameters and functions. (line 336) * __bytes__() (email.message.EmailMessage method): email message Representing an email message. (line 129) * __bytes__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 138) * __bytes__() (object method): Basic customization. (line 144) * __cached__: Import-related module attributes. (line 69) * __callback__ (weakref.ref attribute): weakref — Weak references. (line 121) * __call__() (email.headerregistry.HeaderRegistry method): email headerregistry Custom Header Objects. (line 389) * __call__() (object method): Emulating callable objects. (line 6) * __call__() (object method) <1>: Calls. (line 147) * __call__() (weakref.finalize method): weakref — Weak references. (line 253) * __cause__ (exception attribute): The raise statement. (line 30) * __cause__ (traceback.TracebackException attribute): TracebackException Objects. (line 21) * __ceil__() (fractions.Fraction method): fractions — Rational numbers. (line 158) * __ceil__() (object method): Emulating numeric types. (line 141) * __classcell__ (class namespace entry): Creating the class object. (line 6) * __class_getitem__() (object class method): Emulating generic types. (line 9) * __class__ (instance attribute): The standard type hierarchy. (line 625) * __class__ (instance attribute) <1>: Special Attributes. (line 15) * __class__ (method cell): Creating the class object. (line 6) * __class__ (module attribute): Customizing module attribute access. (line 6) * __class__ (unittest.mock.Mock attribute): The Mock Class. (line 537) * __closure__ (function attribute): The standard type hierarchy. (line 304) * __code__ (function attribute): The standard type hierarchy. (line 304) * __code__ (function object attribute): Code Objects. (line 6) * __complex__() (object method): Emulating numeric types. (line 119) * __concat__() (in module operator): operator — Standard operators as functions. (line 172) * __contains__() (email.message.EmailMessage method): email message Representing an email message. (line 179) * __contains__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 300) * __contains__() (in module operator): operator — Standard operators as functions. (line 177) * __contains__() (mailbox.Mailbox method): Mailbox objects. (line 195) * __contains__() (object method): Emulating container types. (line 148) * __context__ (exception attribute): The raise statement. (line 30) * __context__ (traceback.TracebackException attribute): TracebackException Objects. (line 25) * __copy__() (copy protocol): copy — Shallow and deep copy operations. (line 73) * __debug__: The assert statement. (line 21) * __debug__ (built-in variable): Built-in Constants. (line 58) * __deepcopy__() (copy protocol): copy — Shallow and deep copy operations. (line 73) * __defaults__ (function attribute): The standard type hierarchy. (line 304) * __delattr__() (object method): Customizing attribute access. (line 68) * __delete__() (object method): Implementing Descriptors. (line 40) * __delitem__() (email.message.EmailMessage method): email message Representing an email message. (line 226) * __delitem__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 334) * __delitem__() (in module operator): operator — Standard operators as functions. (line 187) * __delitem__() (mailbox.Mailbox method): Mailbox objects. (line 76) * __delitem__() (mailbox.MH method): MH. (line 76) * __delitem__() (object method): Emulating container types. (line 102) * __del__() (io.IOBase method): I/O Base Classes. (line 164) * __del__() (object method): Basic customization. (line 54) * __dict__ (class attribute): The standard type hierarchy. (line 588) * __dict__ (function attribute): The standard type hierarchy. (line 304) * __dict__ (instance attribute): The standard type hierarchy. (line 625) * __dict__ (module attribute): The standard type hierarchy. (line 547) * __dict__ (module attribute) <1>: Module Objects. (line 42) * __dict__ (object attribute): Special Attributes. (line 10) * __dir__ (module attribute): Customizing module attribute access. (line 6) * __dir__() (object method): Customizing attribute access. (line 77) * __dir__() (unittest.mock.Mock method): The Mock Class. (line 277) * __displayhook__ (in module sys): sys — System-specific parameters and functions. (line 336) * __divmod__() (object method): Emulating numeric types. (line 11) * __doc__ (class attribute): The standard type hierarchy. (line 588) * __doc__ (function attribute): The standard type hierarchy. (line 304) * __doc__ (method attribute): The standard type hierarchy. (line 391) * __doc__ (module attribute): The standard type hierarchy. (line 536) * __doc__ (module attribute) <1>: Module Objects. (line 23) * __doc__ (types.ModuleType attribute): Standard Interpreter Types. (line 126) * __enter__() (contextmanager method): Context Manager Types. (line 12) * __enter__() (object method): With Statement Context Managers. (line 21) * __enter__() (winreg.PyHKEY method): Registry Handle Objects. (line 56) * __eq__() (email.charset.Charset method): email charset Representing character sets. (line 150) * __eq__() (email.header.Header method): email header Internationalized headers. (line 170) * __eq__() (in module operator): operator — Standard operators as functions. (line 24) * __eq__() (instance method): Comparisons<2>. (line 50) * __eq__() (memoryview method): Memory Views. (line 108) * __eq__() (object method): Basic customization. (line 173) * __excepthook__ (in module sys): sys — System-specific parameters and functions. (line 336) * __exit__() (contextmanager method): Context Manager Types. (line 32) * __exit__() (object method): With Statement Context Managers. (line 27) * __exit__() (winreg.PyHKEY method): Registry Handle Objects. (line 56) * __file__: Import-related module attributes. (line 67) * __file__ (module attribute): The standard type hierarchy. (line 536) * __file__ (module attribute) <1>: Module Objects. (line 23) * __file__ (module attribute) <2>: Module Objects. (line 81) * __float__() (object method): Emulating numeric types. (line 119) * __floordiv__() (in module operator): operator — Standard operators as functions. (line 88) * __floordiv__() (object method): Emulating numeric types. (line 11) * __floor__() (fractions.Fraction method): fractions — Rational numbers. (line 148) * __floor__() (object method): Emulating numeric types. (line 141) * __format__: Built-in Functions. (line 643) * __format__() (datetime.date method): date Objects. (line 274) * __format__() (datetime.datetime method): datetime Objects. (line 706) * __format__() (datetime.time method): time Objects. (line 215) * __format__() (object method): Basic customization. (line 150) * __fspath__() (os.PathLike method): Process Parameters. (line 120) * __func__ (method attribute): The standard type hierarchy. (line 391) * __future__: Glossary. (line 484) * __future__ (module): __future__ — Future statement definitions. (line 6) * __future__; future statement: Future statements. (line 6) * __getattribute__() (object method): Customizing attribute access. (line 32) * __getattr__ (module attribute): Customizing module attribute access. (line 6) * __getattr__() (object method): Customizing attribute access. (line 10) * __getitem__() (email.headerregistry.HeaderRegistry method): email headerregistry Custom Header Objects. (line 384) * __getitem__() (email.message.EmailMessage method): email message Representing an email message. (line 189) * __getitem__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 309) * __getitem__() (in module operator): operator — Standard operators as functions. (line 192) * __getitem__() (mailbox.Mailbox method): Mailbox objects. (line 140) * __getitem__() (mapping object method): Special method names. (line 6) * __getitem__() (object method): Emulating container types. (line 76) * __getitem__() (re.Match method): Match Objects. (line 83) * __getnewargs_ex__() (object method): Pickling Class Instances. (line 29) * __getnewargs__() (object method): Pickling Class Instances. (line 47) * __getstate__() (copy protocol): Handling Stateful Objects. (line 6) * __getstate__() (object method): Pickling Class Instances. (line 61) * __get__() (object method): Implementing Descriptors. (line 13) * __ge__() (in module operator): operator — Standard operators as functions. (line 24) * __ge__() (instance method): Comparisons<2>. (line 50) * __ge__() (object method): Basic customization. (line 173) * __globals__ (function attribute): The standard type hierarchy. (line 304) * __gt__() (in module operator): operator — Standard operators as functions. (line 24) * __gt__() (instance method): Comparisons<2>. (line 50) * __gt__() (object method): Basic customization. (line 173) * __hash__() (object method): Basic customization. (line 221) * __iadd__() (in module operator): In-place Operators. (line 36) * __iadd__() (object method): Emulating numeric types. (line 77) * __iand__() (in module operator): In-place Operators. (line 41) * __iand__() (object method): Emulating numeric types. (line 77) * __iconcat__() (in module operator): In-place Operators. (line 46) * __ifloordiv__() (in module operator): In-place Operators. (line 52) * __ifloordiv__() (object method): Emulating numeric types. (line 77) * __ilshift__() (in module operator): In-place Operators. (line 57) * __ilshift__() (object method): Emulating numeric types. (line 77) * __imatmul__() (in module operator): In-place Operators. (line 72) * __imatmul__() (object method): Emulating numeric types. (line 77) * __imod__() (in module operator): In-place Operators. (line 62) * __imod__() (object method): Emulating numeric types. (line 77) * __import__() (built-in function): Built-in Functions. (line 1772) * __import__() (in module importlib): Functions<10>. (line 6) * __imul__() (in module operator): In-place Operators. (line 67) * __imul__() (object method): Emulating numeric types. (line 77) * __index__() (in module operator): operator — Standard operators as functions. (line 93) * __index__() (object method): Emulating numeric types. (line 127) * __init_subclass__() (object class method): Customizing class creation. (line 13) * __init__() (difflib.HtmlDiff method): difflib — Helpers for computing deltas. (line 91) * __init__() (logging.Handler method): Handler Objects. (line 13) * __init__() (logging.logging.Formatter method): Formatters. (line 13) * __init__() (object method): Basic customization. (line 38) * __instancecheck__() (class method): Customizing instance and subclass checks. (line 15) * __interactivehook__ (in module sys): sys — System-specific parameters and functions. (line 953) * __int__() (object method): Emulating numeric types. (line 119) * __invert__() (in module operator): operator — Standard operators as functions. (line 98) * __invert__() (object method): Emulating numeric types. (line 111) * __inv__() (in module operator): operator — Standard operators as functions. (line 98) * __ior__() (in module operator): In-place Operators. (line 79) * __ior__() (object method): Emulating numeric types. (line 77) * __ipow__() (in module operator): In-place Operators. (line 84) * __ipow__() (object method): Emulating numeric types. (line 77) * __irshift__() (in module operator): In-place Operators. (line 89) * __irshift__() (object method): Emulating numeric types. (line 77) * __isub__() (in module operator): In-place Operators. (line 94) * __isub__() (object method): Emulating numeric types. (line 77) * __iter__() (container method): Iterator Types. (line 14) * __iter__() (iterator method): Iterator Types. (line 29) * __iter__() (mailbox.Mailbox method): Mailbox objects. (line 114) * __iter__() (object method): Emulating container types. (line 116) * __iter__() (unittest.TestSuite method): Grouping tests. (line 60) * __itruediv__() (in module operator): In-place Operators. (line 99) * __itruediv__() (object method): Emulating numeric types. (line 77) * __ixor__() (in module operator): In-place Operators. (line 104) * __ixor__() (object method): Emulating numeric types. (line 77) * __kwdefaults__ (function attribute): The standard type hierarchy. (line 304) * __length_hint__() (object method): Emulating container types. (line 52) * __len__() (email.message.EmailMessage method): email message Representing an email message. (line 175) * __len__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 296) * __len__() (mailbox.Mailbox method): Mailbox objects. (line 200) * __len__() (mapping object method): Basic customization. (line 304) * __len__() (object method): Emulating container types. (line 37) * __le__() (in module operator): operator — Standard operators as functions. (line 24) * __le__() (instance method): Comparisons<2>. (line 50) * __le__() (object method): Basic customization. (line 173) * __loader__: Import-related module attributes. (line 16) * __loader__ (module attribute): Module Objects. (line 23) * __loader__ (types.ModuleType attribute): Standard Interpreter Types. (line 130) * __lshift__() (in module operator): operator — Standard operators as functions. (line 106) * __lshift__() (object method): Emulating numeric types. (line 11) * __lt__() (in module operator): operator — Standard operators as functions. (line 24) * __lt__() (instance method): Comparisons<2>. (line 50) * __lt__() (object method): Basic customization. (line 173) * __main__ (module): __main__ — Top-level script environment. (line 6) * __matmul__() (in module operator): operator — Standard operators as functions. (line 121) * __matmul__() (object method): Emulating numeric types. (line 11) * __missing__(): Mapping Types — dict. (line 96) * __missing__() (collections.defaultdict method): defaultdict objects. (line 22) * __missing__() (object method): Emulating container types. (line 111) * __module__ (class attribute): The standard type hierarchy. (line 588) * __module__ (function attribute): The standard type hierarchy. (line 304) * __module__ (method attribute): The standard type hierarchy. (line 391) * __mod__() (in module operator): operator — Standard operators as functions. (line 111) * __mod__() (object method): Emulating numeric types. (line 11) * __mro__ (class attribute): Special Attributes. (line 35) * __mul__() (in module operator): operator — Standard operators as functions. (line 116) * __mul__() (object method): Emulating numeric types. (line 11) * __name__: Import-related module attributes. (line 10) * __name__ (class attribute): The standard type hierarchy. (line 588) * __name__ (definition attribute): Special Attributes. (line 23) * __name__ (function attribute): The standard type hierarchy. (line 304) * __name__ (method attribute): The standard type hierarchy. (line 391) * __name__ (module attribute): The standard type hierarchy. (line 536) * __name__ (module attribute) <1>: Module Objects. (line 23) * __name__ (module attribute) <2>: Module Objects. (line 55) * __name__ (types.ModuleType attribute): Standard Interpreter Types. (line 148) * __neg__() (in module operator): operator — Standard operators as functions. (line 128) * __neg__() (object method): Emulating numeric types. (line 111) * __new__() (object method): Basic customization. (line 6) * __next__() (csv.csvreader method): Reader Objects. (line 9) * __next__() (generator method): Generator-iterator methods. (line 12) * __next__() (iterator method): Iterator Types. (line 37) * __ne__() (email.charset.Charset method): email charset Representing character sets. (line 155) * __ne__() (email.header.Header method): email header Internationalized headers. (line 175) * __ne__() (in module operator): operator — Standard operators as functions. (line 24) * __ne__() (instance method): Comparisons<2>. (line 50) * __ne__() (object method): Basic customization. (line 173) * __not__() (in module operator): operator — Standard operators as functions. (line 49) * __or__() (in module operator): operator — Standard operators as functions. (line 133) * __or__() (object method): Emulating numeric types. (line 11) * __package__: Import-related module attributes. (line 23) * __package__ (module attribute): Module Objects. (line 23) * __package__ (types.ModuleType attribute): Standard Interpreter Types. (line 153) * __path__: Import-related module attributes. (line 56) * __pos__() (in module operator): operator — Standard operators as functions. (line 138) * __pos__() (object method): Emulating numeric types. (line 111) * __pow__() (in module operator): operator — Standard operators as functions. (line 143) * __pow__() (object method): Emulating numeric types. (line 11) * __prepare__ (metaclass method): Preparing the class namespace. (line 6) * __qualname__ (definition attribute): Special Attributes. (line 28) * __radd__() (object method): Emulating numeric types. (line 41) * __rand__() (object method): Emulating numeric types. (line 41) * __rdivmod__() (object method): Emulating numeric types. (line 41) * __reduce_ex__() (object method): Pickling Class Instances. (line 161) * __reduce__() (object method): Pickling Class Instances. (line 106) * __repr__() (multiprocessing.managers.BaseProxy method): Proxy Objects. (line 145) * __repr__() (netrc.netrc method): netrc Objects. (line 16) * __repr__() (object method): Basic customization. (line 113) * __reversed__() (object method): Emulating container types. (line 127) * __rfloordiv__() (object method): Emulating numeric types. (line 41) * __rlshift__() (object method): Emulating numeric types. (line 41) * __rmatmul__() (object method): Emulating numeric types. (line 41) * __rmod__() (object method): Emulating numeric types. (line 41) * __rmul__() (object method): Emulating numeric types. (line 41) * __ror__() (object method): Emulating numeric types. (line 41) * __round__() (fractions.Fraction method): fractions — Rational numbers. (line 163) * __round__() (object method): Emulating numeric types. (line 141) * __rpow__() (object method): Emulating numeric types. (line 41) * __rrshift__() (object method): Emulating numeric types. (line 41) * __rshift__() (in module operator): operator — Standard operators as functions. (line 148) * __rshift__() (object method): Emulating numeric types. (line 11) * __rsub__() (object method): Emulating numeric types. (line 41) * __rtruediv__() (object method): Emulating numeric types. (line 41) * __rxor__() (object method): Emulating numeric types. (line 41) * __self__ (method attribute): The standard type hierarchy. (line 391) * __setattr__() (object method): Customizing attribute access. (line 53) * __setitem__() (email.message.EmailMessage method): email message Representing an email message. (line 204) * __setitem__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 320) * __setitem__() (in module operator): operator — Standard operators as functions. (line 201) * __setitem__() (mailbox.Mailbox method): Mailbox objects. (line 90) * __setitem__() (mailbox.Maildir method): Maildir. (line 91) * __setitem__() (object method): Emulating container types. (line 93) * __setstate__() (copy protocol): Handling Stateful Objects. (line 6) * __setstate__() (object method): Pickling Class Instances. (line 70) * __set_name__() (object method): Implementing Descriptors. (line 45) * __set__() (object method): Implementing Descriptors. (line 31) * __slots__: Glossary. (line 1142) * __spec__: Import-related module attributes. (line 40) * __spec__ (types.ModuleType attribute): Standard Interpreter Types. (line 174) * __stderr__ (in module sys): sys — System-specific parameters and functions. (line 1526) * __stdin__ (in module sys): sys — System-specific parameters and functions. (line 1526) * __stdout__ (in module sys): sys — System-specific parameters and functions. (line 1526) * __str__() (datetime.date method): date Objects. (line 247) * __str__() (datetime.datetime method): datetime Objects. (line 676) * __str__() (datetime.time method): time Objects. (line 205) * __str__() (email.charset.Charset method): email charset Representing character sets. (line 145) * __str__() (email.header.Header method): email header Internationalized headers. (line 158) * __str__() (email.headerregistry.Address method): email headerregistry Custom Header Objects. (line 447) * __str__() (email.headerregistry.Group method): email headerregistry Custom Header Objects. (line 482) * __str__() (email.message.EmailMessage method): email message Representing an email message. (line 95) * __str__() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 101) * __str__() (multiprocessing.managers.BaseProxy method): Proxy Objects. (line 149) * __str__() (object method): Basic customization. (line 129) * __subclasscheck__() (class method): Customizing instance and subclass checks. (line 21) * __subclasses__() (class method): Special Attributes. (line 46) * __subclasshook__() (abc.ABCMeta method): abc — Abstract Base Classes. (line 92) * __sub__() (in module operator): operator — Standard operators as functions. (line 153) * __sub__() (object method): Emulating numeric types. (line 11) * __suppress_context__ (traceback.TracebackException attribute): TracebackException Objects. (line 30) * __traceback__ (exception attribute): The raise statement. (line 6) * __truediv__() (in module operator): operator — Standard operators as functions. (line 158) * __truediv__() (object method): Emulating numeric types. (line 11) * __trunc__() (object method): Emulating numeric types. (line 141) * __unraisablehook__ (in module sys): sys — System-specific parameters and functions. (line 336) * __xor__() (in module operator): operator — Standard operators as functions. (line 164) * __xor__() (object method): Emulating numeric types. (line 11) * {} (curly brackets); dictionary expression: Dictionary displays. (line 6) * {} (curly brackets); in formatted string literal: String literal concatenation. (line 24) * {} (curly brackets); in regular expressions: Regular Expression Syntax. (line 95) * {} (curly brackets); in string formatting: Format String Syntax. (line 13) * {} (curly brackets); set expression: Set displays. (line 6) * | (vertical bar); in regular expressions: Regular Expression Syntax. (line 186) * |=; augmented assignment: Augmented assignment statements. (line 6) * ~ (tilde); home directory expansion: os path — Common pathname manipulations. (line 135) * A (in module re): Module Contents. (line 44) * a-LAW: audioop — Manipulate raw audio data. (line 17) * A-LAW: aifc — Read and write AIFF and AIFC files. (line 160) * A-LAW <1>: sndhdr — Determine type of sound file. (line 8) * a2b_base64() (in module binascii): binascii — Convert between binary and ASCII. (line 41) * a2b_hex() (in module binascii): binascii — Convert between binary and ASCII. (line 161) * a2b_hqx() (in module binascii): binascii — Convert between binary and ASCII. (line 76) * a2b_qp() (in module binascii): binascii — Convert between binary and ASCII. (line 55) * a2b_uu() (in module binascii): binascii — Convert between binary and ASCII. (line 26) * a85decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 163) * a85encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 140) * ABC (class in abc): abc — Abstract Base Classes. (line 26) * abc (module): abc — Abstract Base Classes. (line 6) * ABCMeta (class in abc): abc — Abstract Base Classes. (line 52) * abiflags (in module sys): sys — System-specific parameters and functions. (line 12) * abort(): Process Control. (line 8) * abort() (asyncio.DatagramTransport method): Datagram Transports. (line 15) * abort() (asyncio.WriteTransport method): Write-only Transports. (line 6) * abort() (ftplib.FTP method): FTP Objects. (line 61) * abort() (in module os): Process Management. (line 16) * abort() (threading.Barrier method): Barrier Objects. (line 82) * above() (curses.panel.Panel method): Panel Objects. (line 13) * ABOVE_NORMAL_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 52) * abs() (built-in function): Built-in Functions. (line 55) * abs() (decimal.Context method): Context objects. (line 230) * abs() (in module operator): operator — Standard operators as functions. (line 73) * abspath() (in module os.path): os path — Common pathname manipulations. (line 54) * abstract base class: Glossary. (line 32) * AbstractAsyncContextManager (class in contextlib): Utilities. (line 19) * AbstractBasicAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 332) * AbstractChildWatcher (class in asyncio): Process Watchers. (line 39) * abstractclassmethod() (in module abc): abc — Abstract Base Classes. (line 237) * AbstractContextManager (class in contextlib): Utilities. (line 8) * AbstractDigestAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 371) * AbstractEventLoop (class in asyncio): Event Loop Implementations. (line 40) * AbstractEventLoopPolicy (class in asyncio): Policy Objects. (line 8) * AbstractFormatter (class in formatter): Formatter Implementations. (line 18) * abstractmethod() (in module abc): abc — Abstract Base Classes. (line 161) * abstractproperty() (in module abc): abc — Abstract Base Classes. (line 281) * AbstractSet (class in typing): Classes functions and decorators. (line 209) * abstractstaticmethod() (in module abc): abc — Abstract Base Classes. (line 259) * AbstractWriter (class in formatter): Writer Implementations. (line 16) * accept() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 231) * accept() (multiprocessing.connection.Listener method): Listeners and Clients. (line 84) * accept() (socket.socket method): Socket Objects. (line 13) * access() (in module os): Files and Directories. (line 51) * accumulate() (in module itertools): Itertool functions. (line 10) * aclose() (agen method): Asynchronous generator-iterator methods. (line 55) * aclose() (contextlib.AsyncExitStack method): Utilities. (line 477) * acos() (in module cmath): Trigonometric functions<2>. (line 6) * acos() (in module math): Trigonometric functions. (line 6) * acosh() (in module cmath): Hyperbolic functions<2>. (line 6) * acosh() (in module math): Hyperbolic functions. (line 9) * acquire() (asyncio.Condition method): Condition. (line 48) * acquire() (asyncio.Lock method): Lock. (line 36) * acquire() (asyncio.Semaphore method): Semaphore. (line 43) * acquire() (logging.Handler method): Handler Objects. (line 26) * acquire() (multiprocessing.Lock method): Synchronization primitives. (line 64) * acquire() (multiprocessing.RLock method): Synchronization primitives. (line 118) * acquire() (threading.Condition method): Condition Objects. (line 85) * acquire() (threading.Lock method): Lock Objects. (line 43) * acquire() (threading.RLock method): RLock Objects. (line 35) * acquire() (threading.Semaphore method): Semaphore Objects. (line 34) * acquire() (_thread.lock method): _thread — Low-level threading API. (line 126) * acquire_lock() (in module imp): imp — Access the import internals. (line 277) * Action (class in argparse): Action classes. (line 11) * action (optparse.Option attribute): Option attributes. (line 11) * ACTIONS (optparse.Option attribute): Adding new actions. (line 31) * active_children() (in module multiprocessing): Miscellaneous<3>. (line 6) * active_count() (in module threading): threading — Thread-based parallelism. (line 33) * add() (decimal.Context method): Context objects. (line 234) * add() (frozenset method): Set Types — set frozenset. (line 195) * add() (in module audioop): audioop — Manipulate raw audio data. (line 31) * add() (in module operator): operator — Standard operators as functions. (line 78) * add() (mailbox.Mailbox method): Mailbox objects. (line 59) * add() (mailbox.Maildir method): Maildir. (line 91) * add() (msilib.RadioButtonGroup method): GUI classes. (line 34) * add() (pstats.Stats method): The Stats Class. (line 49) * add() (tarfile.TarFile method): TarFile Objects. (line 200) * add() (tkinter.ttk.Notebook method): ttk Notebook. (line 8) * addAsyncCleanup() (unittest.IsolatedAsyncioTestCase method): Test cases. (line 840) * addaudithook() (in module sys): sys — System-specific parameters and functions. (line 23) * addch() (curses.window method): Window Objects. (line 9) * addClassCleanup() (unittest.TestCase class method): Test cases. (line 776) * addCleanup() (unittest.TestCase method): Test cases. (line 746) * addcomponent() (turtle.Shape method): Public classes. (line 66) * addError() (unittest.TestResult method): Loading and running tests. (line 352) * addExpectedFailure() (unittest.TestResult method): Loading and running tests. (line 388) * addFailure() (unittest.TestResult method): Loading and running tests. (line 363) * addfile() (tarfile.TarFile method): TarFile Objects. (line 218) * addFilter() (logging.Handler method): Handler Objects. (line 52) * addFilter() (logging.Logger method): Logger Objects. (line 251) * addHandler() (logging.Logger method): Logger Objects. (line 268) * addition: Binary arithmetic operations. (line 60) * addLevelName() (in module logging): Module-Level Functions. (line 190) * addModuleCleanup() (in module unittest): setUpModule and tearDownModule. (line 22) * addnstr() (curses.window method): Window Objects. (line 23) * AddPackagePath() (in module modulefinder): modulefinder — Find modules used by a script. (line 16) * addr (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 52) * Address (class in email.headerregistry): email headerregistry Custom Header Objects. (line 402) * address (email.headerregistry.SingleAddressHeader attribute): email headerregistry Custom Header Objects. (line 222) * address (multiprocessing.connection.Listener attribute): Listeners and Clients. (line 99) * address (multiprocessing.managers.BaseManager attribute): Managers. (line 120) * addresses (email.headerregistry.AddressHeader attribute): email headerregistry Custom Header Objects. (line 195) * addresses (email.headerregistry.Group attribute): email headerregistry Custom Header Objects. (line 477) * AddressHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 180) * addressof() (in module ctypes): Utility functions. (line 6) * AddressValueError: Custom Exceptions. (line 9) * address_exclude() (ipaddress.IPv4Network method): Network objects. (line 157) * address_exclude() (ipaddress.IPv6Network method): Network objects. (line 338) * address_family (socketserver.BaseServer attribute): Server Objects<2>. (line 65) * address_string() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 323) * addr_spec (email.headerregistry.Address attribute): email headerregistry Custom Header Objects. (line 441) * addshape() (in module turtle): Settings and special methods. (line 71) * addsitedir() (in module site): Module contents<3>. (line 51) * addSkip() (unittest.TestResult method): Loading and running tests. (line 380) * addstr() (curses.window method): Window Objects. (line 31) * addSubTest() (unittest.TestResult method): Loading and running tests. (line 406) * addSuccess() (unittest.TestResult method): Loading and running tests. (line 374) * addTest() (unittest.TestSuite method): Grouping tests. (line 25) * addTests() (unittest.TestSuite method): Grouping tests. (line 30) * addTypeEqualityFunc() (unittest.TestCase method): Test cases. (line 564) * addUnexpectedSuccess() (unittest.TestResult method): Loading and running tests. (line 398) * add_alias() (in module email.charset): email charset Representing character sets. (line 193) * add_alternative() (email.message.EmailMessage method): email message Representing an email message. (line 640) * add_argument() (argparse.ArgumentParser method): The add_argument method. (line 6) * add_argument_group() (argparse.ArgumentParser method): Argument groups. (line 6) * add_attachment() (email.message.EmailMessage method): email message Representing an email message. (line 652) * add_cgi_vars() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 132) * add_charset() (in module email.charset): email charset Representing character sets. (line 164) * add_child_handler() (asyncio.AbstractChildWatcher method): Process Watchers. (line 41) * add_codec() (in module email.charset): email charset Representing character sets. (line 202) * add_cookie_header() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 11) * add_data() (in module msilib): msilib — Read and write Microsoft Installer files. (line 74) * add_dll_directory() (in module os): Process Management. (line 24) * add_done_callback() (asyncio.Future method): Future Object. (line 77) * add_done_callback() (asyncio.Task method): Task Object. (line 148) * add_done_callback() (concurrent.futures.Future method): Future Objects. (line 70) * add_fallback() (gettext.NullTranslations method): The NullTranslations class. (line 28) * add_file() (msilib.Directory method): Directory Objects. (line 30) * add_flag() (mailbox.MaildirMessage method): MaildirMessage. (line 76) * add_flag() (mailbox.mboxMessage method): mboxMessage. (line 79) * add_flag() (mailbox.MMDFMessage method): MMDFMessage. (line 78) * add_flowing_data() (formatter.formatter method): The Formatter Interface. (line 43) * add_folder() (mailbox.Maildir method): Maildir. (line 71) * add_folder() (mailbox.MH method): MH. (line 42) * add_get_handler() (email.contentmanager.ContentManager method): email contentmanager Managing MIME Content. (line 75) * add_handler() (urllib.request.OpenerDirector method): OpenerDirector Objects. (line 8) * add_header() (email.message.EmailMessage method): email message Representing an email message. (line 260) * add_header() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 368) * add_header() (urllib.request.Request method): Request Objects. (line 79) * add_header() (wsgiref.headers.Headers method): wsgiref headers – WSGI response header tools. (line 61) * add_history() (in module readline): History list. (line 38) * add_hor_rule() (formatter.formatter method): The Formatter Interface. (line 36) * add_include_dir() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 96) * add_label() (mailbox.BabylMessage method): BabylMessage. (line 55) * add_label_data() (formatter.formatter method): The Formatter Interface. (line 59) * add_library() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 113) * add_library_dir() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 135) * add_line_break() (formatter.formatter method): The Formatter Interface. (line 31) * add_link_object() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 180) * add_literal_data() (formatter.formatter method): The Formatter Interface. (line 53) * add_mutually_exclusive_group() (argparse.ArgumentParser method): Mutual exclusion. (line 6) * add_option() (optparse.OptionParser method): Defining options. (line 14) * add_parent() (urllib.request.BaseHandler method): BaseHandler Objects. (line 10) * add_password() (urllib.request.HTTPPasswordMgr method): HTTPPasswordMgr Objects. (line 9) * add_password() (urllib.request.HTTPPasswordMgrWithPriorAuth method): HTTPPasswordMgrWithPriorAuth Objects. (line 10) * add_reader() (asyncio.loop method): Watching file descriptors. (line 6) * add_related() (email.message.EmailMessage method): email message Representing an email message. (line 627) * add_runtime_library_dir() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 150) * add_section() (configparser.ConfigParser method): ConfigParser Objects. (line 86) * add_section() (configparser.RawConfigParser method): RawConfigParser Objects. (line 26) * add_sequence() (mailbox.MHMessage method): MHMessage. (line 41) * add_set_handler() (email.contentmanager.ContentManager method): email contentmanager Managing MIME Content. (line 80) * add_signal_handler() (asyncio.loop method): Unix signals. (line 6) * add_stream() (in module msilib): msilib — Read and write Microsoft Installer files. (line 104) * add_subparsers() (argparse.ArgumentParser method): Sub-commands. (line 6) * add_tables() (in module msilib): msilib — Read and write Microsoft Installer files. (line 95) * add_type() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 107) * add_unredirected_header() (urllib.request.Request method): Request Objects. (line 90) * add_writer() (asyncio.loop method): Watching file descriptors. (line 16) * adjusted() (decimal.Decimal method): Decimal objects. (line 114) * adler32() (in module zlib): zlib — Compression compatible with gzip. (line 28) * ADPCM, Intel/DVI: audioop — Manipulate raw audio data. (line 17) * adpcm2lin() (in module audioop): audioop — Manipulate raw audio data. (line 38) * AF_ALG (in module socket): Constants<8>. (line 183) * AF_CAN (in module socket): Constants<8>. (line 93) * AF_INET (in module socket): Constants<8>. (line 11) * AF_INET6 (in module socket): Constants<8>. (line 11) * AF_LINK (in module socket): Constants<8>. (line 207) * AF_PACKET (in module socket): Constants<8>. (line 144) * AF_QIPCRTR (in module socket): Constants<8>. (line 235) * AF_RDS (in module socket): Constants<8>. (line 154) * AF_UNIX (in module socket): Constants<8>. (line 11) * AF_VSOCK (in module socket): Constants<8>. (line 194) * aifc (module): aifc — Read and write AIFF and AIFC files. (line 6) * aifc() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 134) * AIFF: aifc — Read and write AIFF and AIFC files. (line 8) * AIFF <1>: chunk — Read IFF chunked data. (line 8) * aiff() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 128) * AIFF-C: aifc — Read and write AIFF and AIFC files. (line 8) * AIFF-C <1>: chunk — Read IFF chunked data. (line 8) * alarm() (in module signal): Module contents<2>. (line 224) * alaw2lin() (in module audioop): audioop — Manipulate raw audio data. (line 45) * AlertDescription (class in ssl): Constants<9>. (line 486) * ALERT_DESCRIPTION_HANDSHAKE_FAILURE (in module ssl): Constants<9>. (line 472) * ALERT_DESCRIPTION_INTERNAL_ERROR (in module ssl): Constants<9>. (line 472) * algorithms_available (in module hashlib): Hash algorithms. (line 81) * algorithms_guaranteed (in module hashlib): Hash algorithms. (line 72) * alias (pdb command): Debugger Commands. (line 283) * alignment() (in module ctypes): Utility functions. (line 14) * alive (weakref.finalize attribute): weakref — Weak references. (line 270) * all() (built-in function): Built-in Functions. (line 62) * allocate_lock() (in module _thread): _thread — Low-level threading API. (line 68) * allocfunc (C type): Slot Type typedefs. (line 6) * allowed_domains() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 65) * allow_reuse_address (socketserver.BaseServer attribute): Server Objects<2>. (line 92) * all_errors (in module ftplib): ftplib — FTP protocol client. (line 135) * all_features (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 90) * all_frames (tracemalloc.Filter attribute): Filter. (line 57) * all_properties (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 122) * all_suffixes() (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 57) * all_tasks() (asyncio.Task class method): Task Object. (line 232) * all_tasks() (in module asyncio): Introspection. (line 16) * alt() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 218) * altsep (in module os): Miscellaneous System Information. (line 102) * altzone (in module time): Timezone Constants. (line 6) * ALT_DIGITS (in module locale): locale — Internationalization services. (line 296) * ALWAYS_EQ (in module test.support): test support — Utilities for the Python test suite. (line 145) * ALWAYS_TYPED_ACTIONS (optparse.Option attribute): Adding new actions. (line 43) * AMPER (in module token): token — Constants used with Python parse trees. (line 102) * AMPEREQUAL (in module token): token — Constants used with Python parse trees. (line 190) * and_() (in module operator): operator — Standard operators as functions. (line 83) * annotated; assignment: Annotated assignment statements. (line 6) * annotation: Glossary. (line 47) * annotation (inspect.Parameter attribute): Introspecting callables with the Signature object. (line 175) * announce() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 503) * anonymous; function: Lambdas. (line 6) * answer_challenge() (in module multiprocessing.connection): Listeners and Clients. (line 25) * anticipate_failure() (in module test.support): test support — Utilities for the Python test suite. (line 568) * Any (in module typing): Classes functions and decorators. (line 773) * ANY (in module unittest.mock): ANY. (line 6) * any() (built-in function): Built-in Functions. (line 73) * AnyStr (in module typing): Classes functions and decorators. (line 950) * api_version (in module sys): sys — System-specific parameters and functions. (line 1643) * apop() (poplib.POP3 method): POP3 Objects. (line 41) * APPDATA: PEP 370 Per-user site-packages Directory. (line 26) * append() (array.array method): array — Efficient arrays of numeric values. (line 113) * append() (collections.deque method): deque objects. (line 35) * append() (email.header.Header method): email header Internationalized headers. (line 96) * append() (imaplib.IMAP4 method): IMAP4 Objects. (line 33) * append() (msilib.CAB method): CAB Objects. (line 15) * append() (pipes.Template method): Template Objects. (line 22) * append() (sequence method): Mutable Sequence Types. (line 16) * append() (xml.etree.ElementTree.Element method): Element Objects. (line 87) * appendChild() (xml.dom.Node method): Node Objects. (line 115) * appendleft() (collections.deque method): deque objects. (line 39) * append_history_file() (in module readline): History file. (line 20) * application_uri() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 32) * apply (2to3 fixer): Fixers. (line 10) * apply() (multiprocessing.pool.Pool method): Process Pools. (line 63) * apply_async() (multiprocessing.pool.Pool method): Process Pools. (line 71) * apply_defaults() (inspect.BoundArguments method): Introspecting callables with the Signature object. (line 312) * architecture() (in module platform): Cross Platform. (line 6) * archive (zipimport.zipimporter attribute): zipimporter Objects. (line 69) * aRepr (in module reprlib): reprlib — Alternate repr implementation. (line 24) * argparse (module): argparse — Parser for command-line options arguments and sub-commands. (line 6) * args (BaseException attribute): Base classes. (line 17) * args (functools.partial attribute): partial Objects. (line 15) * args (inspect.BoundArguments attribute): Introspecting callables with the Signature object. (line 298) * args (pdb command): Debugger Commands. (line 229) * args (subprocess.CompletedProcess attribute): Using the subprocess Module. (line 96) * args (subprocess.Popen attribute): Popen Objects. (line 97) * args_from_interpreter_flags() (in module test.support): test support — Utilities for the Python test suite. (line 392) * argtypes (ctypes._FuncPtr attribute): Foreign functions. (line 36) * argument: Glossary. (line 61) * argument; call semantics: Slicings. (line 38) * argument; difference from parameter: How can I pass optional or keyword parameters from one function to another?. (line 17) * argument; function definition: Function definitions. (line 53) * ArgumentDefaultsHelpFormatter (class in argparse): formatter_class. (line 10) * ArgumentError: Foreign functions. (line 83) * ArgumentParser (class in argparse): ArgumentParser objects. (line 6) * arguments (inspect.BoundArguments attribute): Introspecting callables with the Signature object. (line 282) * argv (in module sys): sys — System-specific parameters and functions. (line 56) * argv (in module sys) <1>: Process-wide parameters. (line 217) * arithmetic: Numeric Types — int float complex. (line 27) * arithmetic; conversion: Arithmetic conversions. (line 6) * ArithmeticError: Base classes. (line 43) * array (class in array): array — Efficient arrays of numeric values. (line 75) * Array (class in ctypes): Arrays and pointers. (line 6) * array (module): array — Efficient arrays of numeric values. (line 6) * Array() (in module multiprocessing): Shared ctypes Objects. (line 42) * Array() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 51) * Array() (multiprocessing.managers.SyncManager method): Managers. (line 196) * arrays: array — Efficient arrays of numeric values. (line 6) * arraysize (sqlite3.Cursor attribute): Cursor Objects. (line 214) * article() (nntplib.NNTP method): Methods<3>. (line 241) * as; except clause: The try statement. (line 40) * as; import statement: The import statement. (line 38) * as; with statement: The with statement. (line 6) * ASCII: Notation. (line 31) * ASCII <1>: Literals. (line 8) * ASCII (in module re): Module Contents. (line 44) * ascii() (built-in function): Built-in Functions. (line 84) * ascii() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 209) * ascii_letters (in module string): String constants. (line 8) * ascii_lowercase (in module string): String constants. (line 14) * ascii_uppercase (in module string): String constants. (line 19) * asctime() (in module time): Functions<2>. (line 6) * asdict() (in module dataclasses): Module-level decorators classes and functions. (line 269) * asend() (agen method): Asynchronous generator-iterator methods. (line 28) * asin() (in module cmath): Trigonometric functions<2>. (line 13) * asin() (in module math): Trigonometric functions. (line 10) * asinh() (in module cmath): Hyperbolic functions<2>. (line 12) * asinh() (in module math): Hyperbolic functions. (line 13) * assertAlmostEqual() (unittest.TestCase method): Test cases. (line 484) * assertCountEqual() (unittest.TestCase method): Test cases. (line 543) * assertDictEqual() (unittest.TestCase method): Test cases. (line 652) * assertEqual() (unittest.TestCase method): Test cases. (line 177) * assertFalse() (unittest.TestCase method): Test cases. (line 202) * assertGreater() (unittest.TestCase method): Test cases. (line 509) * assertGreaterEqual() (unittest.TestCase method): Test cases. (line 509) * assertIn() (unittest.TestCase method): Test cases. (line 229) * AssertionError: Concrete exceptions. (line 8) * assertIs() (unittest.TestCase method): Test cases. (line 214) * assertIsInstance() (unittest.TestCase method): Test cases. (line 236) * assertIsNone() (unittest.TestCase method): Test cases. (line 222) * assertIsNot() (unittest.TestCase method): Test cases. (line 214) * assertIsNotNone() (unittest.TestCase method): Test cases. (line 222) * assertLess() (unittest.TestCase method): Test cases. (line 509) * assertLessEqual() (unittest.TestCase method): Test cases. (line 509) * assertListEqual() (unittest.TestCase method): Test cases. (line 629) * assertLogs() (unittest.TestCase method): Test cases. (line 405) * assertMultiLineEqual() (unittest.TestCase method): Test cases. (line 604) * assertNotAlmostEqual() (unittest.TestCase method): Test cases. (line 484) * assertNotEqual() (unittest.TestCase method): Test cases. (line 197) * assertNotIn() (unittest.TestCase method): Test cases. (line 229) * assertNotIsInstance() (unittest.TestCase method): Test cases. (line 236) * assertNotRegex() (unittest.TestCase method): Test cases. (line 522) * assertRaises() (unittest.TestCase method): Test cases. (line 271) * assertRaisesRegex() (unittest.TestCase method): Test cases. (line 312) * assertRegex() (unittest.TestCase method): Test cases. (line 522) * asserts (2to3 fixer): Fixers. (line 15) * assertSequenceEqual() (unittest.TestCase method): Test cases. (line 614) * assertSetEqual() (unittest.TestCase method): Test cases. (line 640) * assertTrue() (unittest.TestCase method): Test cases. (line 202) * assertTupleEqual() (unittest.TestCase method): Test cases. (line 629) * assertWarns() (unittest.TestCase method): Test cases. (line 339) * assertWarnsRegex() (unittest.TestCase method): Test cases. (line 380) * assert_any_await() (unittest.mock.AsyncMock method): The Mock Class. (line 809) * assert_any_call() (unittest.mock.Mock method): The Mock Class. (line 147) * assert_awaited() (unittest.mock.AsyncMock method): The Mock Class. (line 739) * assert_awaited_once() (unittest.mock.AsyncMock method): The Mock Class. (line 759) * assert_awaited_once_with() (unittest.mock.AsyncMock method): The Mock Class. (line 792) * assert_awaited_with() (unittest.mock.AsyncMock method): The Mock Class. (line 775) * assert_called() (unittest.mock.Mock method): The Mock Class. (line 95) * assert_called_once() (unittest.mock.Mock method): The Mock Class. (line 106) * assert_called_once_with() (unittest.mock.Mock method): The Mock Class. (line 133) * assert_called_with() (unittest.mock.Mock method): The Mock Class. (line 123) * assert_has_awaits() (unittest.mock.AsyncMock method): The Mock Class. (line 826) * assert_has_calls() (unittest.mock.Mock method): The Mock Class. (line 163) * assert_line_data() (formatter.formatter method): The Formatter Interface. (line 143) * assert_not_awaited() (unittest.mock.AsyncMock method): The Mock Class. (line 853) * assert_not_called() (unittest.mock.Mock method): The Mock Class. (line 184) * assert_python_failure() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 50) * assert_python_ok() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 37) * assignment; statement: The standard type hierarchy. (line 192) * assignment; statement <1>: Assignment statements. (line 6) * AST (class in ast): Node classes. (line 6) * ast (module): ast — Abstract Syntax Trees. (line 6) * astimezone() (datetime.datetime method): datetime Objects. (line 426) * astuple() (in module dataclasses): Module-level decorators classes and functions. (line 294) * ASYNC (in module token): token — Constants used with Python parse trees. (line 246) * async for; in comprehensions: Displays for lists sets and dictionaries. (line 14) * AsyncContextManager (class in typing): Classes functions and decorators. (line 340) * asynccontextmanager() (in module contextlib): Utilities. (line 91) * AsyncExitStack (class in contextlib): Utilities. (line 453) * AsyncGenerator (class in collections.abc): Collections Abstract Base Classes. (line 244) * AsyncGenerator (class in typing): Classes functions and decorators. (line 423) * AsyncGeneratorType (in module types): Standard Interpreter Types. (line 43) * asynchat (module): asynchat — Asynchronous socket command/response handler. (line 6) * asynchronous context manager: Glossary. (line 94) * asynchronous generator: Glossary. (line 100) * asynchronous generator iterator: Glossary. (line 117) * asynchronous generator; asynchronous iterator: The standard type hierarchy. (line 467) * asynchronous generator; function: The standard type hierarchy. (line 467) * asynchronous iterable: Glossary. (line 134) * asynchronous iterator: Glossary. (line 140) * asyncio (module): asyncio — Asynchronous I/O. (line 6) * asyncio.subprocess.DEVNULL (in module asyncio): Constants<7>. (line 23) * asyncio.subprocess.PIPE (in module asyncio): Constants<7>. (line 6) * asyncio.subprocess.Process (class in asyncio): Interacting with Subprocesses. (line 11) * asyncio.subprocess.STDOUT (in module asyncio): Constants<7>. (line 17) * AsyncIterable (class in collections.abc): Collections Abstract Base Classes. (line 230) * AsyncIterable (class in typing): Classes functions and decorators. (line 320) * AsyncIterator (class in collections.abc): Collections Abstract Base Classes. (line 237) * AsyncIterator (class in typing): Classes functions and decorators. (line 326) * AsyncMock (class in unittest.mock): The Mock Class. (line 667) * asyncore (module): asyncore — Asynchronous socket handler. (line 6) * AsyncResult (class in multiprocessing.pool): Process Pools. (line 191) * asyncSetUp() (unittest.IsolatedAsyncioTestCase method): Test cases. (line 816) * asyncTearDown() (unittest.IsolatedAsyncioTestCase method): Test cases. (line 825) * async_chat (class in asynchat): asynchat — Asynchronous socket command/response handler. (line 28) * async_chat.ac_in_buffer_size (in module asynchat): asynchat — Asynchronous socket command/response handler. (line 47) * async_chat.ac_out_buffer_size (in module asynchat): asynchat — Asynchronous socket command/response handler. (line 51) * as_bytes() (email.message.EmailMessage method): email message Representing an email message. (line 107) * as_bytes() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 106) * as_completed() (in module asyncio): Waiting Primitives. (line 86) * as_completed() (in module concurrent.futures): Module Functions. (line 43) * as_integer_ratio() (decimal.Decimal method): Decimal objects. (line 122) * as_integer_ratio() (float method): Additional Methods on Float. (line 9) * as_integer_ratio() (fractions.Fraction method): fractions — Rational numbers. (line 98) * as_integer_ratio() (int method): Additional Methods on Integer Types. (line 98) * AS_IS (in module formatter): The Formatter Interface. (line 12) * as_posix() (pathlib.PurePath method): Methods and properties. (line 142) * as_string() (email.message.EmailMessage method): email message Representing an email message. (line 61) * as_string() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 60) * as_tuple() (decimal.Decimal method): Decimal objects. (line 136) * as_uri() (pathlib.PurePath method): Methods and properties. (line 153) * AT (in module token): token — Constants used with Python parse trees. (line 222) * atan() (in module cmath): Trigonometric functions<2>. (line 18) * atan() (in module math): Trigonometric functions. (line 14) * atan2() (in module math): Trigonometric functions. (line 18) * atanh() (in module cmath): Hyperbolic functions<2>. (line 19) * atanh() (in module math): Hyperbolic functions. (line 17) * ATEQUAL (in module token): token — Constants used with Python parse trees. (line 226) * atexit (module): atexit — Exit handlers. (line 6) * atexit (weakref.finalize attribute): weakref — Weak references. (line 275) * athrow() (agen method): Asynchronous generator-iterator methods. (line 43) * atof() (in module locale): locale — Internationalization services. (line 448) * atoi() (in module locale): locale — Internationalization services. (line 453) * atom: Atoms. (line 6) * attach() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 167) * attach_loop() (asyncio.AbstractChildWatcher method): Process Watchers. (line 59) * attach_mock() (unittest.mock.Mock method): The Mock Class. (line 235) * AttlistDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 208) * attrgetter() (in module operator): operator — Standard operators as functions. (line 221) * attrib (xml.etree.ElementTree.Element attribute): Element Objects. (line 45) * attribute: The standard type hierarchy. (line 13) * attribute <1>: Glossary. (line 149) * attribute; assignment: Assignment statements. (line 6) * attribute; assignment <1>: Assignment statements. (line 78) * attribute; deletion: The del statement<2>. (line 20) * attribute; reference: Attribute references. (line 6) * AttributeError: Concrete exceptions. (line 12) * attributes (xml.dom.Node attribute): Node Objects. (line 26) * AttributesImpl (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 69) * AttributesNSImpl (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 80) * attroff() (curses.window method): Window Objects. (line 53) * attron() (curses.window method): Window Objects. (line 58) * attrset() (curses.window method): Window Objects. (line 63) * at_eof() (asyncio.StreamReader method): StreamReader. (line 64) * Audio Interchange File Format: aifc — Read and write AIFF and AIFC files. (line 8) * Audio Interchange File Format <1>: chunk — Read IFF chunked data. (line 8) * AUDIODEV: ossaudiodev — Access to OSS-compatible audio devices. (line 54) * audioop (module): audioop — Manipulate raw audio data. (line 6) * AUDIO_FILE_ENCODING_ADPCM_G721 (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_ADPCM_G722 (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_ADPCM_G723_3 (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_ADPCM_G723_5 (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_ALAW_8 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_ENCODING_DOUBLE (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_FLOAT (in module sunau): sunau — Read and write Sun AU files. (line 98) * AUDIO_FILE_ENCODING_LINEAR_16 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_ENCODING_LINEAR_24 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_ENCODING_LINEAR_32 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_ENCODING_LINEAR_8 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_ENCODING_MULAW_8 (in module sunau): sunau — Read and write Sun AU files. (line 88) * AUDIO_FILE_MAGIC (in module sunau): sunau — Read and write Sun AU files. (line 82) * audit events: Debugging and Profiling. (line 11) * audit() (in module sys): sys — System-specific parameters and functions. (line 74) * auditing: sys — System-specific parameters and functions. (line 76) * augmented; assignment: Augmented assignment statements. (line 6) * auth() (ftplib.FTP_TLS method): FTP_TLS Objects. (line 14) * auth() (smtplib.SMTP method): SMTP Objects. (line 141) * authenticate() (imaplib.IMAP4 method): IMAP4 Objects. (line 37) * AuthenticationError: Process and exceptions. (line 216) * authenticators() (netrc.netrc method): netrc Objects. (line 8) * authkey (multiprocessing.Process attribute): Process and exceptions. (line 118) * auto (class in enum): Module Contents<2>. (line 39) * autorange() (timeit.Timer method): Python Interface. (line 90) * avg() (in module audioop): audioop — Manipulate raw audio data. (line 51) * avgpp() (in module audioop): audioop — Manipulate raw audio data. (line 55) * avoids_symlink_attacks (shutil.rmtree attribute): Directory and files operations. (line 293) * AWAIT (in module token): token — Constants used with Python parse trees. (line 244) * await; in comprehensions: Displays for lists sets and dictionaries. (line 45) * awaitable: Glossary. (line 155) * Awaitable (class in collections.abc): Collections Abstract Base Classes. (line 194) * Awaitable (class in typing): Classes functions and decorators. (line 298) * await_args (unittest.mock.AsyncMock attribute): The Mock Class. (line 882) * await_args_list (unittest.mock.AsyncMock attribute): The Mock Class. (line 900) * await_count (unittest.mock.AsyncMock attribute): The Mock Class. (line 866) * b"; bytes literal: String and Bytes literals. (line 43) * b’; bytes literal: String and Bytes literals. (line 43) * b16decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 128) * b16encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 123) * b2a_base64() (in module binascii): binascii — Convert between binary and ASCII. (line 46) * b2a_hex() (in module binascii): binascii — Convert between binary and ASCII. (line 131) * b2a_hqx() (in module binascii): binascii — Convert between binary and ASCII. (line 100) * b2a_qp() (in module binascii): binascii — Convert between binary and ASCII. (line 62) * b2a_uu() (in module binascii): binascii — Convert between binary and ASCII. (line 32) * b32decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 103) * b32encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 98) * b64decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 55) * b64encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 43) * b85decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 195) * b85encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 184) * Babyl (class in mailbox): Babyl. (line 6) * BabylMessage (class in mailbox): BabylMessage. (line 6) * back() (in module turtle): Turtle motion. (line 24) * backslash character: Explicit line joining. (line 6) * backslashreplace_errors() (in module codecs): Error Handlers. (line 151) * backup() (sqlite3.Connection method): Connection Objects. (line 403) * backward() (in module turtle): Turtle motion. (line 24) * BadGzipFile: gzip — Support for gzip files. (line 63) * BadStatusLine: http client — HTTP protocol client. (line 174) * BadZipFile: zipfile — Work with ZIP archives. (line 24) * BadZipfile: zipfile — Work with ZIP archives. (line 30) * Balloon (class in tkinter.tix): Basic Widgets. (line 6) * Barrier (class in multiprocessing): Synchronization primitives. (line 13) * Barrier (class in threading): Barrier Objects. (line 36) * Barrier() (multiprocessing.managers.SyncManager method): Managers. (line 143) * base64 (module): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 6) * base64; encoding: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 8) * BaseCGIHandler (class in wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 53) * BaseCookie (class in http.cookies): http cookies — HTTP state management. (line 38) * BaseException: Base classes. (line 9) * BaseHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 272) * BaseHandler (class in wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 88) * BaseHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 37) * BaseHTTPRequestHandler (class in http.server): http server — HTTP servers. (line 46) * BaseManager (class in multiprocessing.managers): Managers. (line 23) * basename() (in module os.path): os path — Common pathname manipulations. (line 62) * BaseProtocol (class in asyncio): Base Protocols. (line 6) * BaseProxy (class in multiprocessing.managers): Proxy Objects. (line 92) * BaseRequestHandler (class in socketserver): Request Handler Objects. (line 6) * BaseRotatingHandler (class in logging.handlers): BaseRotatingHandler. (line 12) * BaseSelector (class in selectors): Classes<3>. (line 53) * BaseServer (class in socketserver): Server Objects<2>. (line 6) * basestring (2to3 fixer): Fixers. (line 60) * BaseTransport (class in asyncio): Transports Hierarchy. (line 6) * base_exec_prefix (in module sys): sys — System-specific parameters and functions. (line 105) * base_prefix (in module sys): sys — System-specific parameters and functions. (line 119) * basicConfig() (in module logging): Module-Level Functions. (line 244) * BasicContext (class in decimal): Context objects. (line 47) * BasicInterpolation (class in configparser): Interpolation of values. (line 10) * BasicTestRunner (class in test.support): test support — Utilities for the Python test suite. (line 1102) * baudrate() (in module curses): Functions<3>. (line 18) * bbox() (tkinter.ttk.Treeview method): ttk Treeview. (line 8) * BDADDR_ANY (in module socket): Constants<8>. (line 218) * BDADDR_LOCAL (in module socket): Constants<8>. (line 218) * Bdb (class in bdb): bdb — Debugger framework. (line 79) * bdb (module): bdb — Debugger framework. (line 6) * BdbQuit: bdb — Debugger framework. (line 15) * BDFL: Glossary. (line 161) * bdist_msi (class in distutils.command.bdist_msi): distutils command bdist_msi — Build a Microsoft Installer binary package. (line 6) * beep() (in module curses): Functions<3>. (line 26) * Beep() (in module winsound): winsound — Sound-playing interface for Windows. (line 12) * BEFORE_ASYNC_WITH (opcode): Python Bytecode Instructions. (line 295) * begin_fill() (in module turtle): Filling. (line 16) * BEGIN_FINALLY (opcode): Python Bytecode Instructions. (line 406) * begin_poly() (in module turtle): Special Turtle methods. (line 6) * below() (curses.panel.Panel method): Panel Objects. (line 17) * BELOW_NORMAL_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 59) * benchmarking: Functions<2>. (line 182) * benchmarking <1>: Functions<2>. (line 200) * benchmarking <2>: Functions<2>. (line 479) * Benchmarking: timeit — Measure execution time of small code snippets. (line 8) * betavariate() (in module random): Real-valued distributions. (line 33) * bgcolor() (in module turtle): Window control. (line 6) * bgpic() (in module turtle): Window control. (line 21) * bias() (in module audioop): audioop — Manipulate raw audio data. (line 61) * bidirectional() (in module unicodedata): unicodedata — Unicode Database. (line 54) * bigaddrspacetest() (in module test.support): test support — Utilities for the Python test suite. (line 676) * BigEndianStructure (class in ctypes): Structured data types. (line 10) * bigmemtest() (in module test.support): test support — Utilities for the Python test suite. (line 660) * bin() (built-in function): Built-in Functions. (line 92) * Binary (class in msilib): msilib — Read and write Microsoft Installer files. (line 89) * Binary (class in xmlrpc.client): Binary Objects. (line 6) * binary file: Glossary. (line 166) * binary literal: Numeric literals. (line 6) * binary mode: Built-in Functions. (line 1217) * binary semaphores: _thread — Low-level threading API. (line 6) * binary; arithmetic; operation: Binary arithmetic operations. (line 6) * binary; bitwise; operation: Binary bitwise operations. (line 6) * binary; literals: Numeric Types — int float complex. (line 19) * binaryfunc (C type): Slot Type typedefs. (line 111) * BinaryIO (class in typing): Classes functions and decorators. (line 471) * BINARY_ADD (opcode): Python Bytecode Instructions. (line 157) * BINARY_AND (opcode): Python Bytecode Instructions. (line 177) * BINARY_FLOOR_DIVIDE (opcode): Python Bytecode Instructions. (line 145) * BINARY_LSHIFT (opcode): Python Bytecode Instructions. (line 169) * BINARY_MATRIX_MULTIPLY (opcode): Python Bytecode Instructions. (line 139) * BINARY_MODULO (opcode): Python Bytecode Instructions. (line 153) * BINARY_MULTIPLY (opcode): Python Bytecode Instructions. (line 135) * BINARY_OR (opcode): Python Bytecode Instructions. (line 185) * BINARY_POWER (opcode): Python Bytecode Instructions. (line 131) * BINARY_RSHIFT (opcode): Python Bytecode Instructions. (line 173) * BINARY_SUBSCR (opcode): Python Bytecode Instructions. (line 165) * BINARY_SUBTRACT (opcode): Python Bytecode Instructions. (line 161) * BINARY_TRUE_DIVIDE (opcode): Python Bytecode Instructions. (line 149) * BINARY_XOR (opcode): Python Bytecode Instructions. (line 181) * binascii (module): binascii — Convert between binary and ASCII. (line 6) * bind (widgets): Bindings and Events. (line 6) * bind() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 222) * bind() (inspect.Signature method): Introspecting callables with the Signature object. (line 96) * bind() (socket.socket method): Socket Objects. (line 30) * binding; name: Binding of names. (line 6) * binding; name <1>: Assignment statements. (line 6) * bindtextdomain() (in module gettext): GNU gettext API. (line 14) * bindtextdomain() (in module locale): Access to message catalogs. (line 14) * bind_partial() (inspect.Signature method): Introspecting callables with the Signature object. (line 103) * bind_port() (in module test.support): test support — Utilities for the Python test suite. (line 804) * bind_textdomain_codeset() (in module gettext): GNU gettext API. (line 26) * bind_unix_socket() (in module test.support): test support — Utilities for the Python test suite. (line 821) * binhex (module): binhex — Encode and decode binhex4 files. (line 6) * binhex() (in module binhex): binhex — Encode and decode binhex4 files. (line 16) * bisect (module): bisect — Array bisection algorithm. (line 6) * bisect() (in module bisect): bisect — Array bisection algorithm. (line 34) * bisect_left() (in module bisect): bisect — Array bisection algorithm. (line 20) * bisect_right() (in module bisect): bisect — Array bisection algorithm. (line 34) * bitmap() (msilib.Dialog method): GUI classes. (line 60) * bitwise; and: Binary bitwise operations. (line 12) * bitwise; operations: Bitwise Operations on Integer Types. (line 6) * bitwise; or: Binary bitwise operations. (line 18) * bitwise; xor: Binary bitwise operations. (line 15) * bit_length() (int method): Additional Methods on Integer Types. (line 9) * bk() (in module turtle): Turtle motion. (line 24) * bkgd() (curses.window method): Window Objects. (line 68) * bkgdset() (curses.window method): Window Objects. (line 80) * blake2b() (in module hashlib): Creating hash objects. (line 8) * blake2b, blake2s: BLAKE2. (line 6) * blake2b.MAX_DIGEST_SIZE (in module hashlib): Constants<5>. (line 24) * blake2b.MAX_KEY_SIZE (in module hashlib): Constants<5>. (line 18) * blake2b.PERSON_SIZE (in module hashlib): Constants<5>. (line 12) * blake2b.SALT_SIZE (in module hashlib): Constants<5>. (line 6) * blake2s() (in module hashlib): Creating hash objects. (line 13) * blake2s.MAX_DIGEST_SIZE (in module hashlib): Constants<5>. (line 26) * blake2s.MAX_KEY_SIZE (in module hashlib): Constants<5>. (line 20) * blake2s.PERSON_SIZE (in module hashlib): Constants<5>. (line 14) * blake2s.SALT_SIZE (in module hashlib): Constants<5>. (line 8) * blank line: Blank lines. (line 6) * block: Structure of a program. (line 6) * blocked_domains() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 52) * BlockingIOError: OS exceptions. (line 9) * BlockingIOError <1>: High-level Module Interface. (line 38) * blocksize (http.client.HTTPConnection attribute): HTTPConnection Objects. (line 115) * block_size (hmac.HMAC attribute): hmac — Keyed-Hashing for Message Authentication. (line 94) * BNF: Notation. (line 6) * BNF <1>: Expressions. (line 6) * body() (nntplib.NNTP method): Methods<3>. (line 272) * body_encode() (email.charset.Charset method): email charset Representing character sets. (line 135) * body_encoding (email.charset.Charset attribute): email charset Representing character sets. (line 67) * body_line_iterator() (in module email.iterators): email iterators Iterators. (line 14) * BOM (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_BE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_LE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF16 (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF16_BE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF16_LE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF32 (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF32_BE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF32_LE (in module codecs): codecs — Codec registry and base classes. (line 241) * BOM_UTF8 (in module codecs): codecs — Codec registry and base classes. (line 241) * bool (built-in class): Built-in Functions. (line 114) * Boolean; operation: Boolean operations. (line 6) * Boolean; operations: Truth Value Testing. (line 6) * Boolean; operations <1>: Boolean Operations — and or not. (line 6) * Boolean; type: Built-in Functions. (line 124) * Boolean; values: Boolean Values. (line 15) * BOOLEAN_STATES (configparser.ConfigParser attribute): Customizing Parser Behaviour. (line 245) * bootstrap() (in module ensurepip): Module API. (line 13) * border() (curses.window method): Window Objects. (line 91) * bottom() (curses.panel.Panel method): Panel Objects. (line 21) * bottom_panel() (in module curses.panel): Functions<4>. (line 8) * BoundArguments (class in inspect): Introspecting callables with the Signature object. (line 276) * BoundaryError: email errors Exception and Defect classes. (line 38) * BoundedSemaphore (class in asyncio): BoundedSemaphore. (line 6) * BoundedSemaphore (class in multiprocessing): Synchronization primitives. (line 19) * BoundedSemaphore (class in threading): Semaphore Objects. (line 69) * BoundedSemaphore() (multiprocessing.managers.SyncManager method): Managers. (line 150) * box() (curses.window method): Window Objects. (line 130) * bpformat() (bdb.Breakpoint method): bdb — Debugger framework. (line 55) * bpprint() (bdb.Breakpoint method): bdb — Debugger framework. (line 74) * break (pdb command): Debugger Commands. (line 71) * Breakpoint (class in bdb): bdb — Debugger framework. (line 22) * breakpoint() (built-in function): Built-in Functions. (line 126) * breakpointhook() (in module sys): sys — System-specific parameters and functions. (line 187) * breakpoints: Help menu Shell and Editor. (line 29) * break_anywhere() (bdb.Bdb method): bdb — Debugger framework. (line 204) * break_here() (bdb.Bdb method): bdb — Debugger framework. (line 197) * break_long_words (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 238) * break_on_hyphens (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 248) * broadcast_address (ipaddress.IPv4Network attribute): Network objects. (line 91) * broadcast_address (ipaddress.IPv6Network attribute): Network objects. (line 308) * broken (threading.Barrier attribute): Barrier Objects. (line 101) * BrokenBarrierError: Barrier Objects. (line 106) * BrokenExecutor: Exception classes. (line 14) * BrokenPipeError: OS exceptions. (line 37) * BrokenProcessPool: Exception classes. (line 37) * BrokenThreadPool: Exception classes. (line 29) * BROWSER: webbrowser — Convenient Web-browser controller. (line 20) * BROWSER <1>: webbrowser — Convenient Web-browser controller. (line 95) * BsdDbShelf (class in shelve): Restrictions. (line 52) * buf (multiprocessing.shared_memory.SharedMemory attribute): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 87) * buffer (2to3 fixer): Fixers. (line 64) * buffer (io.TextIOBase attribute): Text I/O<2>. (line 30) * buffer (unittest.TestResult attribute): Loading and running tests. (line 277) * buffer interface; (see buffer protocol): Iterator Protocol. (line 45) * buffer object; (see buffer protocol): Iterator Protocol. (line 44) * buffer protocol: Iterator Protocol. (line 45) * buffer protocol; binary sequence types: printf-style String Formatting. (line 189) * buffer protocol; str (built-in class): Text Sequence Type — str. (line 60) * buffer size, I/O: Built-in Functions. (line 1217) * BufferedIOBase (class in io): I/O Base Classes. (line 223) * BufferedProtocol (class in asyncio): Base Protocols. (line 15) * BufferedRandom (class in io): Buffered Streams. (line 134) * BufferedReader (class in io): Buffered Streams. (line 56) * BufferedRWPair (class in io): Buffered Streams. (line 147) * BufferedWriter (class in io): Buffered Streams. (line 95) * BufferError: Base classes. (line 49) * BufferingHandler (class in logging.handlers): MemoryHandler. (line 19) * BufferTooShort: Process and exceptions. (line 208) * buffer_info() (array.array method): array — Efficient arrays of numeric values. (line 117) * buffer_size (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 84) * buffer_text (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 91) * buffer_updated() (asyncio.BufferedProtocol method): Buffered Streaming Protocols. (line 35) * buffer_used (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 100) * bufsize() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 214) * BUILD_CONST_KEY_MAP (opcode): Python Bytecode Instructions. (line 558) * BUILD_LIST (opcode): Python Bytecode Instructions. (line 540) * BUILD_LIST_UNPACK (opcode): Python Bytecode Instructions. (line 590) * BUILD_MAP (opcode): Python Bytecode Instructions. (line 548) * BUILD_MAP_UNPACK (opcode): Python Bytecode Instructions. (line 606) * BUILD_MAP_UNPACK_WITH_CALL (opcode): Python Bytecode Instructions. (line 614) * build_opener() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 125) * build_py (class in distutils.command.build_py): distutils command build_py — Build the py/ pyc files of a package. (line 6) * build_py_2to3 (class in distutils.command.build_py): distutils command build_py — Build the py/ pyc files of a package. (line 8) * BUILD_SET (opcode): Python Bytecode Instructions. (line 544) * BUILD_SET_UNPACK (opcode): Python Bytecode Instructions. (line 598) * BUILD_SLICE (opcode): Python Bytecode Instructions. (line 861) * BUILD_STRING (opcode): Python Bytecode Instructions. (line 567) * BUILD_TUPLE (opcode): Python Bytecode Instructions. (line 535) * BUILD_TUPLE_UNPACK (opcode): Python Bytecode Instructions. (line 574) * BUILD_TUPLE_UNPACK_WITH_CALL (opcode): Python Bytecode Instructions. (line 582) * built-in function; abs: Emulating numeric types. (line 116) * built-in function; abs <1>: Number Protocol. (line 86) * built-in function; ascii: Object Protocol. (line 177) * built-in function; bytes: Basic customization. (line 146) * built-in function; bytes <1>: Object Protocol. (line 198) * built-in function; call: Calls. (line 132) * built-in function; chr: The standard type hierarchy. (line 156) * built-in function; classmethod: Common Object Structures. (line 227) * built-in function; compile: The global statement. (line 27) * built-in function; compile <1>: Code Objects. (line 6) * built-in function; compile <2>: Standard Interpreter Types. (line 52) * built-in function; compile <3>: Queries on ST Objects. (line 14) * built-in function; compile <4>: Importing Modules<2>. (line 119) * built-in function; complex: Emulating numeric types. (line 123) * built-in function; complex <1>: Numeric Types — int float complex. (line 27) * built-in function; divmod: Emulating numeric types. (line 26) * built-in function; divmod <1>: Emulating numeric types. (line 56) * built-in function; divmod <2>: Number Protocol. (line 59) * built-in function; eval: The global statement. (line 27) * built-in function; eval <1>: Expression input. (line 6) * built-in function; eval <2>: Code Objects. (line 14) * built-in function; eval <3>: pprint — Data pretty printer. (line 132) * built-in function; eval <4>: PrettyPrinter Objects. (line 26) * built-in function; eval <5>: Converting ST Objects. (line 45) * built-in function; exec: The global statement. (line 27) * built-in function; exec <1>: Built-in Functions. (line 519) * built-in function; exec <2>: Code Objects. (line 14) * built-in function; exec <3>: Converting ST Objects. (line 45) * built-in function; float: Emulating numeric types. (line 123) * built-in function; float <1>: Numeric Types — int float complex. (line 27) * built-in function; float <2>: Number Protocol. (line 238) * built-in function; hash: Basic customization. (line 223) * built-in function; hash <1>: Immutable Sequence Types. (line 6) * built-in function; hash <2>: Object Protocol. (line 425) * built-in function; hash <3>: PyTypeObject Slots. (line 316) * built-in function; help: Operating System Interface. (line 20) * built-in function; id: Objects values and types. (line 11) * built-in function; int: Emulating numeric types. (line 123) * built-in function; int <1>: Numeric Types — int float complex. (line 27) * built-in function; int <2>: Number Protocol. (line 231) * built-in function; len: The standard type hierarchy. (line 127) * built-in function; len <1>: The standard type hierarchy. (line 219) * built-in function; len <2>: The standard type hierarchy. (line 249) * built-in function; len <3>: Emulating container types. (line 39) * built-in function; len <4>: Common Sequence Operations. (line 21) * built-in function; len <5>: Mapping Types — dict. (line 6) * built-in function; len <6>: Object Protocol. (line 471) * built-in function; len <7>: Sequence Protocol. (line 17) * built-in function; len <8>: Mapping Protocol. (line 20) * built-in function; len <9>: List Objects. (line 39) * built-in function; len <10>: Dictionary Objects. (line 136) * built-in function; len <11>: Set Objects. (line 90) * built-in function; max: Common Sequence Operations. (line 21) * built-in function; min: Common Sequence Operations. (line 21) * built-in function; open: Reading and Writing Files. (line 6) * built-in function; open <1>: The standard type hierarchy. (line 630) * built-in function; ord: The standard type hierarchy. (line 156) * built-in function; pow: Emulating numeric types. (line 26) * built-in function; pow <1>: Emulating numeric types. (line 26) * built-in function; pow <2>: Emulating numeric types. (line 56) * built-in function; pow <3>: Emulating numeric types. (line 66) * built-in function; pow <4>: Number Protocol. (line 68) * built-in function; pow <5>: Number Protocol. (line 183) * built-in function; print: Basic customization. (line 150) * built-in function; range: The for statement. (line 38) * built-in function; repr: Expression statements. (line 17) * built-in function; repr <1>: Finalization and De-allocation. (line 78) * built-in function; repr <2>: Object Protocol. (line 165) * built-in function; repr <3>: PyTypeObject Slots. (line 257) * built-in function; round: Emulating numeric types. (line 146) * built-in function; slice: The standard type hierarchy. (line 799) * built-in function; slice <1>: Python Bytecode Instructions. (line 863) * built-in function; staticmethod: Common Object Structures. (line 234) * built-in function; tuple: Sequence Protocol. (line 119) * built-in function; tuple <1>: List Objects. (line 126) * built-in function; type: Objects values and types. (line 11) * built-in function; type <1>: Metaclasses. (line 6) * built-in function; type <2>: Type Objects. (line 6) * built-in function; type <3>: Object Protocol. (line 452) * built-in function; __import__: Importing Modules<2>. (line 38) * built-in method; call: Calls. (line 132) * built-in; method: The standard type hierarchy. (line 498) * built-in; types: Built-in Types. (line 9) * BuiltinFunctionType (in module types): Standard Interpreter Types. (line 81) * BuiltinImporter (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 67) * BuiltinMethodType (in module types): Standard Interpreter Types. (line 81) * builtins (module): builtins — Built-in objects. (line 6) * builtin_module_names (in module sys): sys — System-specific parameters and functions. (line 140) * ButtonBox (class in tkinter.tix): Basic Widgets. (line 13) * bye() (in module turtle): Methods specific to Screen not inherited from TurtleScreen. (line 6) * byref() (in module ctypes): Utility functions. (line 19) * byte: The standard type hierarchy. (line 183) * bytearray: The standard type hierarchy. (line 207) * bytearray (built-in class): Bytearray Objects. (line 9) * bytearray; formatting: printf-style Bytes Formatting. (line 6) * bytearray; interpolation: printf-style Bytes Formatting. (line 6) * bytearray; methods: Bytes and Bytearray Operations. (line 6) * bytecode: The standard type hierarchy. (line 649) * bytecode <1>: Glossary. (line 196) * Bytecode (class in dis): Bytecode analysis. (line 12) * Bytecode.codeobj (in module dis): Bytecode analysis. (line 39) * Bytecode.first_line (in module dis): Bytecode analysis. (line 43) * BYTECODE_SUFFIXES (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 40) * byteorder (in module sys): sys — System-specific parameters and functions. (line 133) * bytes: The standard type hierarchy. (line 183) * bytes (built-in class): Bytes Objects. (line 12) * bytes (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 84) * bytes literal: Literals. (line 8) * bytes-like object: Glossary. (line 177) * bytes; formatting: printf-style Bytes Formatting. (line 6) * bytes; interpolation: printf-style Bytes Formatting. (line 6) * bytes; methods: Bytes and Bytearray Operations. (line 6) * bytes; str (built-in class): Text Sequence Type — str. (line 60) * BytesFeedParser (class in email.parser): FeedParser API. (line 28) * BytesGenerator (class in email.generator): email generator Generating MIME documents. (line 43) * BytesHeaderParser (class in email.parser): Parser API. (line 67) * BytesIO (class in io): Buffered Streams. (line 9) * BytesParser (class in email.parser): Parser API. (line 17) * ByteString (class in collections.abc): Collections Abstract Base Classes. (line 159) * ByteString (class in typing): Classes functions and decorators. (line 237) * byteswap() (array.array method): array — Efficient arrays of numeric values. (line 136) * byteswap() (in module audioop): audioop — Manipulate raw audio data. (line 66) * BytesWarning: Warnings. (line 54) * bytes_le (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 89) * byte_compile() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 127) * bz2 (module): bz2 — Support for bzip2 compression. (line 6) * BZ2Compressor (class in bz2): Incremental de compression. (line 6) * BZ2Decompressor (class in bz2): Incremental de compression. (line 33) * BZ2File (class in bz2): De compression of files. (line 40) * C: String and Bytes literals. (line 72) * C-contiguous: shape strides suboffsets. (line 26) * C-contiguous <1>: Glossary. (line 273) * C14NWriterTarget (class in xml.etree.ElementTree): TreeBuilder Objects. (line 93) * C; language: The standard type hierarchy. (line 6) * C; language <1>: The standard type hierarchy. (line 107) * C; language <2>: The standard type hierarchy. (line 485) * C; language <3>: Comparisons. (line 6) * C; language <4>: Numeric Types — int float complex. (line 6) * C; language <5>: Numeric Types — int float complex. (line 104) * C; structures: struct — Interpret bytes as packed binary data. (line 8) * CAB (class in msilib): CAB Objects. (line 6) * cached (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 403) * cached_property() (in module functools): functools — Higher-order functions and operations on callable objects. (line 16) * CacheFTPHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 430) * cache_from_source() (in module imp): imp — Access the import internals. (line 205) * cache_from_source() (in module importlib.util): importlib util – Utility code for importers. (line 21) * calcobjsize() (in module test.support): test support — Utilities for the Python test suite. (line 531) * calcsize() (in module struct): Functions and Exceptions. (line 55) * calcvobjsize() (in module test.support): test support — Utilities for the Python test suite. (line 536) * Calendar (class in calendar): calendar — General calendar-related functions. (line 27) * calendar (module): calendar — General calendar-related functions. (line 6) * calendar() (in module calendar): calendar — General calendar-related functions. (line 349) * call: Slicings. (line 38) * call() (in module subprocess): Older high-level API. (line 10) * call() (in module unittest.mock): call. (line 6) * call; instance: Emulating callable objects. (line 8) * Callable (class in collections.abc): Collections Abstract Base Classes. (line 116) * Callable (in module typing): Classes functions and decorators. (line 863) * callable() (built-in function): Built-in Functions. (line 193) * CallableProxyType (in module weakref): weakref — Weak references. (line 298) * callback: Glossary. (line 211) * callback (optparse.Option attribute): Option attributes. (line 60) * callback() (contextlib.ExitStack method): Utilities. (line 414) * callbacks (in module gc): gc — Garbage Collector interface. (line 229) * callback_args (optparse.Option attribute): Option attributes. (line 66) * callback_kwargs (optparse.Option attribute): Option attributes. (line 66) * called (unittest.mock.Mock attribute): The Mock Class. (line 296) * CalledProcessError: Using the subprocess Module. (line 190) * calloc(): Overview<3>. (line 33) * call_args (unittest.mock.Mock attribute): The Mock Class. (line 415) * call_args_list (unittest.mock.Mock attribute): The Mock Class. (line 459) * call_at() (asyncio.loop method): Scheduling delayed callbacks. (line 37) * call_count (unittest.mock.Mock attribute): The Mock Class. (line 308) * call_exception_handler() (asyncio.loop method): Error Handling API. (line 37) * CALL_FINALLY (opcode): Python Bytecode Instructions. (line 703) * CALL_FUNCTION (opcode): Python Bytecode Instructions. (line 769) * CALL_FUNCTION_EX (opcode): Python Bytecode Instructions. (line 799) * CALL_FUNCTION_KW (opcode): Python Bytecode Instructions. (line 782) * call_later() (asyncio.loop method): Scheduling delayed callbacks. (line 10) * call_list() (unittest.mock.call method): call. (line 20) * CALL_METHOD (opcode): Python Bytecode Instructions. (line 829) * call_soon() (asyncio.loop method): Scheduling callbacks. (line 6) * call_soon_threadsafe() (asyncio.loop method): Scheduling callbacks. (line 23) * call_tracing() (in module sys): sys — System-specific parameters and functions. (line 147) * cancel() (asyncio.Future method): Future Object. (line 109) * cancel() (asyncio.Handle method): Callback Handles. (line 11) * cancel() (asyncio.Task method): Task Object. (line 52) * cancel() (concurrent.futures.Future method): Future Objects. (line 16) * cancel() (sched.scheduler method): Scheduler Objects. (line 41) * cancel() (threading.Timer method): Timer Objects. (line 35) * cancelled() (asyncio.Future method): Future Object. (line 67) * cancelled() (asyncio.Handle method): Callback Handles. (line 16) * cancelled() (asyncio.Task method): Task Object. (line 104) * cancelled() (concurrent.futures.Future method): Future Objects. (line 24) * CancelledError: Exception classes. (line 6) * CancelledError <1>: Exceptions<9>. (line 17) * cancel_dump_traceback_later() (in module faulthandler): Dumping the tracebacks after a timeout. (line 29) * cancel_join_thread() (multiprocessing.Queue method): Pipes and Queues. (line 182) * CannotSendHeader: http client — HTTP protocol client. (line 166) * CannotSendRequest: http client — HTTP protocol client. (line 162) * canonic() (bdb.Bdb method): bdb — Debugger framework. (line 99) * canonical() (decimal.Context method): Context objects. (line 238) * canonical() (decimal.Decimal method): Decimal objects. (line 141) * canonicalize() (in module xml.etree.ElementTree): Functions<6>. (line 6) * CAN_BCM (in module socket): Constants<8>. (line 107) * can_change_color() (in module curses): Functions<3>. (line 30) * can_fetch() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 33) * CAN_ISOTP (in module socket): Constants<8>. (line 135) * CAN_RAW_FD_FRAMES (in module socket): Constants<8>. (line 122) * can_symlink() (in module test.support): test support — Utilities for the Python test suite. (line 546) * can_write_eof() (asyncio.StreamWriter method): StreamWriter. (line 47) * can_write_eof() (asyncio.WriteTransport method): Write-only Transports. (line 14) * can_xattr() (in module test.support): test support — Utilities for the Python test suite. (line 550) * capa() (poplib.POP3 method): POP3 Objects. (line 24) * capitalize() (bytearray method): Bytes and Bytearray Operations. (line 403) * capitalize() (bytes method): Bytes and Bytearray Operations. (line 403) * capitalize() (str method): String Methods<2>. (line 22) * captured_stderr() (in module test.support): test support — Utilities for the Python test suite. (line 402) * captured_stdin() (in module test.support): test support — Utilities for the Python test suite. (line 402) * captured_stdout() (in module test.support): test support — Utilities for the Python test suite. (line 402) * captureWarnings() (in module logging): Integration with the warnings module. (line 9) * capwords() (in module string): Helper functions. (line 6) * casefold() (str method): String Methods<2>. (line 32) * cast() (in module ctypes): Utility functions. (line 33) * cast() (in module typing): Classes functions and decorators. (line 618) * cast() (memoryview method): Memory Views. (line 269) * cat() (in module nis): nis — Interface to Sun’s NIS Yellow Pages. (line 29) * catch_threading_exception() (in module test.support): test support — Utilities for the Python test suite. (line 826) * catch_unraisable_exception() (in module test.support): test support — Utilities for the Python test suite. (line 861) * catch_warnings (class in warnings): Available Context Managers. (line 6) * category() (in module unicodedata): unicodedata — Unicode Database. (line 49) * cbreak() (in module curses): Functions<3>. (line 35) * CC: New Improved and Deprecated Modules<4>. (line 58) * ccc() (ftplib.FTP_TLS method): FTP_TLS Objects. (line 23) * CCompiler (class in distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 67) * cdf() (statistics.NormalDist method): NormalDist objects. (line 80) * CDLL (class in ctypes): Loading shared libraries. (line 9) * ceil() (in module math): Numeric Types — int float complex. (line 104) * ceil() (in module math) <1>: Number-theoretic and representation functions. (line 6) * CellType (in module types): Standard Interpreter Types. (line 70) * center() (bytearray method): Bytes and Bytearray Operations. (line 236) * center() (bytes method): Bytes and Bytearray Operations. (line 236) * center() (str method): String Methods<2>. (line 48) * CertificateError: Exceptions<12>. (line 94) * certificates: SSL Contexts. (line 669) * CERT_NONE (in module ssl): Constants<9>. (line 11) * CERT_OPTIONAL (in module ssl): Constants<9>. (line 25) * CERT_REQUIRED (in module ssl): Constants<9>. (line 43) * cert_store_stats() (ssl.SSLContext method): SSL Contexts. (line 67) * cert_time_to_seconds() (in module ssl): Certificate handling. (line 48) * CFLAGS: New Improved and Deprecated Modules<4>. (line 58) * CFLAGS <1>: Tweaking compiler/linker flags. (line 66) * CFLAGS <2>: Tweaking compiler/linker flags. (line 67) * CFUNCTYPE() (in module ctypes): Function prototypes. (line 15) * cgi (module): cgi — Common Gateway Interface support. (line 6) * CGI; debugging: Debugging CGI scripts. (line 6) * CGI; exceptions: cgitb — Traceback manager for CGI scripts. (line 8) * CGI; protocol: cgi — Common Gateway Interface support. (line 8) * CGI; security: Caring about security. (line 6) * CGI; tracebacks: cgitb — Traceback manager for CGI scripts. (line 8) * CGIHandler (class in wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 11) * CGIHTTPRequestHandler (class in http.server): http server — HTTP servers. (line 450) * cgitb (module): cgitb — Traceback manager for CGI scripts. (line 6) * CGIXMLRPCRequestHandler (class in xmlrpc.server): xmlrpc server — Basic XML-RPC servers. (line 45) * cgi_directories (http.server.CGIHTTPRequestHandler attribute): http server — HTTP servers. (line 476) * chain() (in module itertools): Itertool functions. (line 85) * chaining; comparisons: Comparisons. (line 17) * chaining; comparisons <1>: Comparisons<2>. (line 6) * ChainMap (class in collections): ChainMap objects. (line 16) * ChainMap (class in typing): Classes functions and decorators. (line 382) * change_cwd() (in module test.support): test support — Utilities for the Python test suite. (line 436) * change_root() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 64) * channels() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 133) * CHANNEL_BINDING_TYPES (in module ssl): Constants<9>. (line 433) * channel_class (smtpd.SMTPServer attribute): SMTPServer Objects. (line 80) * character: The standard type hierarchy. (line 156) * character <1>: Subscriptions. (line 38) * character <2>: unicodedata — Unicode Database. (line 6) * CharacterDataHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 240) * characters() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 129) * characters_written (BlockingIOError attribute): OS exceptions. (line 18) * Charset (class in email.charset): email charset Representing character sets. (line 24) * charset() (gettext.NullTranslations method): The NullTranslations class. (line 83) * CHAR_MAX (in module locale): locale — Internationalization services. (line 504) * chdir() (in module os): Files and Directories. (line 115) * check (lzma.LZMADecompressor attribute): Compressing and decompressing data in memory. (line 159) * check() (imaplib.IMAP4 method): IMAP4 Objects. (line 58) * check() (in module tabnanny): tabnanny — Detection of ambiguous indentation. (line 17) * checkbox() (msilib.Dialog method): GUI classes. (line 78) * checkcache() (in module linecache): linecache — Random access to text lines. (line 43) * CHECKED_HASH (py_compile.PycInvalidationMode attribute): py_compile — Compile Python source files. (line 108) * checkfuncname() (in module bdb): bdb — Debugger framework. (line 386) * CheckList (class in tkinter.tix): Hierarchical ListBox. (line 13) * checksizeof() (in module test.support): test support — Utilities for the Python test suite. (line 541) * checksum; Cyclic Redundancy Check: zlib — Compression compatible with gzip. (line 117) * check_call() (in module subprocess): Older high-level API. (line 36) * check_environ() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 71) * check_free_after_iterating() (in module test.support): test support — Utilities for the Python test suite. (line 956) * check_hostname (ssl.SSLContext attribute): SSL Contexts. (line 492) * check_impl_detail() (in module test.support): test support — Utilities for the Python test suite. (line 287) * check_no_resource_warning() (in module test.support): test support — Utilities for the Python test suite. (line 365) * check_output() (doctest.OutputChecker method): OutputChecker objects. (line 17) * check_output() (in module subprocess): Older high-level API. (line 64) * check_returncode() (subprocess.CompletedProcess method): Using the subprocess Module. (line 125) * check_syntax_error() (in module test.support): test support — Utilities for the Python test suite. (line 686) * check_syntax_warning() (in module test.support): test support — Utilities for the Python test suite. (line 697) * check_unused_args() (string.Formatter method): Custom String Formatting. (line 91) * check_warnings() (in module test.support): test support — Utilities for the Python test suite. (line 296) * check__all__() (in module test.support): test support — Utilities for the Python test suite. (line 968) * chflags() (in module os): Files and Directories. (line 134) * chgat() (curses.window method): Window Objects. (line 136) * childNodes (xml.dom.Node attribute): Node Objects. (line 49) * ChildProcessError: OS exceptions. (line 24) * children (pyclbr.Class attribute): Class Objects<2>. (line 31) * children (pyclbr.Function attribute): Function Objects. (line 31) * chmod() (in module os): Files and Directories. (line 175) * chmod() (pathlib.Path method): Methods<2>. (line 47) * choice() (in module random): Functions for sequences. (line 6) * choice() (in module secrets): Random numbers. (line 15) * choices (optparse.Option attribute): Option attributes. (line 55) * choices() (in module random): Functions for sequences. (line 11) * chown() (in module os): Files and Directories. (line 237) * chown() (in module shutil): Directory and files operations. (line 354) * chr() (built-in function): Built-in Functions. (line 205) * chroot() (in module os): Files and Directories. (line 260) * Chunk (class in chunk): chunk — Read IFF chunked data. (line 49) * chunk (module): chunk — Read IFF chunked data. (line 6) * cipher() (ssl.SSLSocket method): SSL Sockets. (line 209) * cipher; DES: crypt — Function to check Unix passwords. (line 8) * circle() (in module turtle): Turtle motion. (line 177) * CIRCUMFLEX (in module token): token — Constants used with Python parse trees. (line 154) * CIRCUMFLEXEQUAL (in module token): token — Constants used with Python parse trees. (line 198) * Clamped (class in decimal): Signals. (line 20) * class: Glossary. (line 216) * Class (class in symtable): Examining Symbol Tables. (line 93) * Class browser: File menu Shell and Editor. (line 22) * class instance; attribute: The standard type hierarchy. (line 600) * class instance; attribute; assignment: The standard type hierarchy. (line 616) * class instance; call: Calls. (line 141) * class object; call: The standard type hierarchy. (line 573) * class object; call <1>: The standard type hierarchy. (line 585) * class object; call <2>: Calls. (line 137) * class variable: Glossary. (line 222) * class; attribute: The standard type hierarchy. (line 573) * class; attribute; assignment: The standard type hierarchy. (line 582) * class; body: Executing the class body. (line 6) * class; constructor: Basic customization. (line 40) * class; definition: The return statement. (line 6) * class; definition <1>: Class definitions. (line 6) * class; instance: The standard type hierarchy. (line 600) * class; name: Class definitions. (line 6) * classmethod() (built-in function): Built-in Functions. (line 216) * ClassMethodDescriptorType (in module types): Standard Interpreter Types. (line 110) * ClassVar (in module typing): Classes functions and decorators. (line 903) * clause: Compound statements. (line 18) * CLD_CONTINUED (in module os): Process Management. (line 758) * CLD_DUMPED (in module os): Process Management. (line 758) * CLD_EXITED (in module os): Process Management. (line 758) * CLD_TRAPPED (in module os): Process Management. (line 758) * clean() (mailbox.Maildir method): Maildir. (line 82) * cleandoc() (in module inspect): Retrieving source code. (line 65) * CleanImport (class in test.support): test support — Utilities for the Python test suite. (line 1060) * cleanup functions: Process Control. (line 26) * clear (pdb command): Debugger Commands. (line 93) * Clear Breakpoint: Help menu Shell and Editor. (line 30) * clear() (asyncio.Event method): Event. (line 59) * clear() (collections.deque method): deque objects. (line 43) * clear() (curses.window method): Window Objects. (line 152) * clear() (dict method): Mapping Types — dict. (line 142) * clear() (email.message.EmailMessage method): email message Representing an email message. (line 668) * clear() (frame method): The standard type hierarchy. (line 741) * clear() (frozenset method): Set Types — set frozenset. (line 213) * clear() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 77) * clear() (in module turtle): Window control. (line 39) * clear() (mailbox.Mailbox method): Mailbox objects. (line 204) * clear() (sequence method): Mutable Sequence Types. (line 16) * clear() (threading.Event method): Event Objects. (line 33) * clear() (xml.etree.ElementTree.Element method): Element Objects. (line 58) * clearcache() (in module linecache): linecache — Random access to text lines. (line 38) * ClearData() (msilib.Record method): Record Objects. (line 37) * clearok() (curses.window method): Window Objects. (line 157) * clearscreen() (in module turtle): Window control. (line 39) * clearstamp() (in module turtle): Turtle motion. (line 249) * clearstamps() (in module turtle): Turtle motion. (line 268) * clear_all_breaks() (bdb.Bdb method): bdb — Debugger framework. (line 305) * clear_all_file_breaks() (bdb.Bdb method): bdb — Debugger framework. (line 300) * clear_bpbynumber() (bdb.Bdb method): bdb — Debugger framework. (line 294) * clear_break() (bdb.Bdb method): bdb — Debugger framework. (line 289) * clear_cache() (in module filecmp): filecmp — File and Directory Comparisons. (line 53) * clear_content() (email.message.EmailMessage method): email message Representing an email message. (line 672) * clear_flags() (decimal.Context method): Context objects. (line 152) * clear_frames() (in module traceback): traceback — Print or retrieve a stack traceback. (line 150) * clear_history() (in module readline): History list. (line 8) * clear_session_cookies() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 89) * clear_traces() (in module tracemalloc): Functions<9>. (line 6) * clear_traps() (decimal.Context method): Context objects. (line 156) * Client() (in module multiprocessing.connection): Listeners and Clients. (line 34) * client_address (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 66) * CLOCK_BOOTTIME (in module time): Clock ID Constants. (line 9) * clock_getres() (in module time): Functions<2>. (line 38) * clock_gettime() (in module time): Functions<2>. (line 48) * clock_gettime_ns() (in module time): Functions<2>. (line 58) * CLOCK_HIGHRES (in module time): Clock ID Constants. (line 23) * CLOCK_MONOTONIC (in module time): Clock ID Constants. (line 34) * CLOCK_MONOTONIC_RAW (in module time): Clock ID Constants. (line 43) * CLOCK_PROCESS_CPUTIME_ID (in module time): Clock ID Constants. (line 53) * CLOCK_PROF (in module time): Clock ID Constants. (line 61) * CLOCK_REALTIME (in module time): Clock ID Constants. (line 100) * clock_settime() (in module time): Functions<2>. (line 67) * clock_settime_ns() (in module time): Functions<2>. (line 76) * CLOCK_THREAD_CPUTIME_ID (in module time): Clock ID Constants. (line 69) * CLOCK_UPTIME (in module time): Clock ID Constants. (line 77) * CLOCK_UPTIME_RAW (in module time): Clock ID Constants. (line 87) * clone() (email.generator.BytesGenerator method): email generator Generating MIME documents. (line 112) * clone() (email.generator.Generator method): email generator Generating MIME documents. (line 208) * clone() (email.policy.Policy method): email policy Policy Objects. (line 207) * clone() (in module turtle): Special Turtle methods. (line 32) * clone() (pipes.Template method): Template Objects. (line 12) * cloneNode() (xml.dom.Node method): Node Objects. (line 147) * close() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 116) * close() (asyncio.AbstractChildWatcher method): Process Watchers. (line 77) * close() (asyncio.BaseTransport method): Base Transport. (line 6) * close() (asyncio.loop method): Running and stopping the loop. (line 43) * close() (asyncio.Server method): Server Objects. (line 29) * close() (asyncio.StreamWriter method): StreamWriter. (line 37) * close() (asyncio.SubprocessTransport method): Subprocess Transports. (line 59) * close() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 243) * close() (chunk.Chunk method): chunk — Read IFF chunked data. (line 78) * close() (contextlib.ExitStack method): Utilities. (line 446) * close() (coroutine method): Coroutine Objects. (line 45) * close() (dbm.dumb.dumbdbm method): dbm dumb — Portable DBM implementation. (line 83) * close() (dbm.gnu.gdbm method): dbm gnu — GNU’s reinterpretation of dbm. (line 118) * close() (dbm.ndbm.ndbm method): dbm ndbm — Interface based on ndbm. (line 66) * close() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 96) * close() (email.parser.BytesFeedParser method): FeedParser API. (line 65) * close() (ftplib.FTP method): FTP Objects. (line 246) * close() (generator method): Generator-iterator methods. (line 47) * close() (html.parser.HTMLParser method): HTMLParser Methods. (line 15) * close() (http.client.HTTPConnection method): HTTPConnection Objects. (line 111) * close() (imaplib.IMAP4 method): IMAP4 Objects. (line 62) * close() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 127) * close() (in module os): File Descriptor Operations. (line 21) * close() (in module os) <1>: Sub-interpreter support. (line 76) * close() (in module socket): Other functions<2>. (line 9) * close() (io.IOBase method): I/O Base Classes. (line 49) * close() (logging.FileHandler method): FileHandler. (line 23) * close() (logging.Handler method): Handler Objects. (line 73) * close() (logging.handlers.MemoryHandler method): MemoryHandler. (line 55) * close() (logging.handlers.NTEventLogHandler method): NTEventLogHandler. (line 29) * close() (logging.handlers.SocketHandler method): SocketHandler. (line 20) * close() (logging.handlers.SysLogHandler method): SysLogHandler. (line 39) * close() (mailbox.Mailbox method): Mailbox objects. (line 262) * close() (mailbox.Maildir method): Maildir. (line 113) * close() (mailbox.MH method): MH. (line 104) * close() (mmap.mmap method): mmap — Memory-mapped file support. (line 165) * Close() (msilib.Database method): Database Objects. (line 22) * Close() (msilib.View method): View Objects. (line 35) * close() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 35) * close() (multiprocessing.connection.Listener method): Listeners and Clients. (line 91) * close() (multiprocessing.pool.Pool method): Process Pools. (line 168) * close() (multiprocessing.Process method): Process and exceptions. (line 173) * close() (multiprocessing.Queue method): Pipes and Queues. (line 163) * close() (multiprocessing.shared_memory.SharedMemory method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 65) * close() (os.scandir method): Files and Directories. (line 783) * close() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 22) * close() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 8) * close() (select.devpoll method): /dev/poll Polling Objects. (line 12) * close() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 65) * close() (select.kqueue method): Kqueue Objects. (line 6) * close() (selectors.BaseSelector method): Classes<3>. (line 137) * close() (shelve.Shelf method): shelve — Python object persistence. (line 71) * close() (socket.socket method): Socket Objects. (line 39) * close() (sqlite3.Connection method): Connection Objects. (line 45) * close() (sqlite3.Cursor method): Cursor Objects. (line 169) * close() (sunau.AU_read method): AU_read Objects. (line 9) * close() (sunau.AU_write method): AU_write Objects. (line 59) * close() (tarfile.TarFile method): TarFile Objects. (line 248) * close() (telnetlib.Telnet method): Telnet Objects. (line 89) * close() (urllib.request.BaseHandler method): BaseHandler Objects. (line 14) * close() (wave.Wave_read method): Wave_read Objects. (line 9) * close() (wave.Wave_write method): Wave_write Objects. (line 23) * Close() (winreg.PyHKEY method): Registry Handle Objects. (line 34) * close() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 28) * close() (xml.etree.ElementTree.XMLParser method): XMLParser Objects. (line 20) * close() (xml.etree.ElementTree.XMLPullParser method): XMLPullParser Objects. (line 22) * close() (xml.sax.xmlreader.IncrementalParser method): IncrementalParser Objects. (line 13) * close() (zipfile.ZipFile method): ZipFile Objects. (line 86) * closed (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 65) * closed (io.IOBase attribute): I/O Base Classes. (line 59) * closed (mmap.mmap attribute): mmap — Memory-mapped file support. (line 171) * closed (ossaudiodev.oss_audio_device attribute): Audio Device Objects. (line 230) * closed (select.devpoll attribute): /dev/poll Polling Objects. (line 18) * closed (select.epoll attribute): Edge and Level Trigger Polling epoll Objects. (line 69) * closed (select.kqueue attribute): Kqueue Objects. (line 10) * CloseKey() (in module winreg): Functions<11>. (line 8) * closelog() (in module syslog): syslog — Unix syslog library routines. (line 59) * closerange() (in module os): File Descriptor Operations. (line 32) * close_connection (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 75) * close_when_done() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 73) * closing() (in module contextlib): Utilities. (line 121) * clrtobot() (curses.window method): Window Objects. (line 162) * clrtoeol() (curses.window method): Window Objects. (line 168) * cmath (module): cmath — Mathematical functions for complex numbers. (line 6) * Cmd (class in cmd): cmd — Support for line-oriented command interpreters. (line 15) * cmd (module): cmd — Support for line-oriented command interpreters. (line 6) * cmd (subprocess.CalledProcessError attribute): Using the subprocess Module. (line 201) * cmd (subprocess.TimeoutExpired attribute): Using the subprocess Module. (line 164) * cmdloop() (cmd.Cmd method): Cmd Objects. (line 8) * cmdqueue (cmd.Cmd attribute): Cmd Objects. (line 135) * cmp() (in module filecmp): filecmp — File and Directory Comparisons. (line 16) * cmpfiles() (in module filecmp): filecmp — File and Directory Comparisons. (line 33) * cmp_op (in module dis): Opcode collections. (line 17) * cmp_to_key() (in module functools): functools — Higher-order functions and operations on callable objects. (line 48) * CMSG_LEN() (in module socket): Other functions<2>. (line 297) * CMSG_SPACE() (in module socket): Other functions<2>. (line 312) * code (module): code — Interpreter base classes. (line 6) * code (SystemExit attribute): Concrete exceptions. (line 304) * code (urllib.error.HTTPError attribute): urllib error — Exception classes raised by urllib request. (line 38) * code (xml.etree.ElementTree.ParseError attribute): Exceptions<15>. (line 14) * code (xml.parsers.expat.ExpatError attribute): ExpatError Exceptions. (line 9) * code object: The standard type hierarchy. (line 649) * code object <1>: Methods. (line 42) * code object <2>: marshal — Internal Python object serialization. (line 30) * code object <3>: Cell Objects. (line 52) * code; block: Execution model. (line 6) * CodecInfo (class in codecs): codecs — Codec registry and base classes. (line 58) * Codecs: codecs — Codec registry and base classes. (line 8) * codecs (module): codecs — Codec registry and base classes. (line 6) * Codecs; decode: codecs — Codec registry and base classes. (line 8) * Codecs; encode: codecs — Codec registry and base classes. (line 8) * coded_value (http.cookies.Morsel attribute): Morsel Objects. (line 56) * codeop (module): codeop — Compile Python code. (line 6) * codepoint2name (in module html.entities): html entities — Definitions of HTML general entities. (line 35) * codes (in module xml.parsers.expat.errors): Expat error constants. (line 16) * CODESET (in module locale): locale — Internationalization services. (line 184) * CodeType (class in types): Standard Interpreter Types. (line 50) * code_info() (in module dis): Analysis functions. (line 11) * coding; style: Intermezzo Coding Style. (line 6) * coercion: Glossary. (line 227) * collapse_addresses() (in module ipaddress): Other Module Level Functions. (line 43) * collapse_rfc2231_value() (in module email.utils): email utils Miscellaneous utilities. (line 187) * collect() (in module gc): gc — Garbage Collector interface. (line 34) * Collection (class in collections.abc): Collections Abstract Base Classes. (line 131) * Collection (class in typing): Classes functions and decorators. (line 203) * collections (module): collections — Container datatypes. (line 6) * collections.abc (module): collections abc — Abstract Base Classes for Containers. (line 6) * collect_incoming_data() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 78) * colno (json.JSONDecodeError attribute): Exceptions<13>. (line 27) * colno (re.error attribute): Module Contents. (line 379) * COLON (in module token): token — Constants used with Python parse trees. (line 70) * COLONEQUAL (in module token): token — Constants used with Python parse trees. (line 238) * color() (in module turtle): Color control. (line 104) * colormode() (in module turtle): Settings and special methods. (line 34) * colorsys (module): colorsys — Conversions between color systems. (line 6) * color_content() (in module curses): Functions<3>. (line 45) * color_pair() (in module curses): Functions<3>. (line 53) * COLS: curses<2>. (line 7) * COLS <1>: Functions<3>. (line 526) * column() (tkinter.ttk.Treeview method): ttk Treeview. (line 35) * COLUMNS: Functions<3>. (line 550) * COLUMNS <1>: Functions<3>. (line 553) * columns (os.terminal_size attribute): Querying the size of a terminal. (line 30) * col_offset (ast.AST attribute): Node classes. (line 39) * comb() (in module math): Number-theoretic and representation functions. (line 12) * combinations() (in module itertools): Itertool functions. (line 110) * combinations_with_replacement() (in module itertools): Itertool functions. (line 161) * combine() (datetime.datetime class method): datetime Objects. (line 170) * combining() (in module unicodedata): unicodedata — Unicode Database. (line 59) * ComboBox (class in tkinter.tix): Basic Widgets. (line 18) * Combobox (class in tkinter.ttk): ttk Combobox. (line 6) * comma: Parenthesized forms. (line 20) * COMMA (in module token): token — Constants used with Python parse trees. (line 74) * Command (class in distutils.cmd): distutils cmd — Abstract base class for Distutils commands. (line 8) * Command (class in distutils.core): distutils core — Core Distutils functionality. (line 307) * command (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 88) * command line: Complete Python programs. (line 25) * command line option; -?: Generic options. (line 6) * command line option; -b: Miscellaneous options. (line 6) * command line option; -B: Miscellaneous options. (line 16) * command line option; -c : Interface options. (line 36) * command line option; –check-hash-based-pycs default|always|never: Miscellaneous options. (line 21) * command line option; -d: Miscellaneous options. (line 35) * command line option; -E: Miscellaneous options. (line 40) * command line option; -h: Generic options. (line 6) * command line option; –help: Generic options. (line 6) * command line option; -i: Miscellaneous options. (line 45) * command line option; -I: Miscellaneous options. (line 56) * command line option; -J: Options you shouldn’t use. (line 6) * command line option; -m : Interface options. (line 50) * command line option; -O: Miscellaneous options. (line 66) * command line option; -OO: Miscellaneous options. (line 76) * command line option; -q: Miscellaneous options. (line 85) * command line option; -R: Miscellaneous options. (line 92) * command line option; -s: Miscellaneous options. (line 117) * command line option; -S: Miscellaneous options. (line 127) * command line option; -u: Miscellaneous options. (line 135) * command line option; -V: Generic options. (line 12) * command line option; -v: Miscellaneous options. (line 145) * command line option; –version: Generic options. (line 12) * command line option; -W arg: Miscellaneous options. (line 152) * command line option; -x: Miscellaneous options. (line 191) * command line option; -X: Miscellaneous options. (line 196) * CommandCompiler (class in codeop): codeop — Compile Python code. (line 64) * commands (pdb command): Debugger Commands. (line 126) * comment: Comments. (line 6) * comment (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 58) * COMMENT (in module token): token — Constants used with Python parse trees. (line 261) * comment (zipfile.ZipFile attribute): ZipFile Objects. (line 308) * comment (zipfile.ZipInfo attribute): ZipInfo Objects. (line 88) * Comment() (in module xml.etree.ElementTree): Functions<6>. (line 72) * comment() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 49) * commenters (shlex.shlex attribute): shlex Objects. (line 85) * CommentHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 295) * comment_url (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 63) * commit() (msilib.CAB method): CAB Objects. (line 24) * Commit() (msilib.Database method): Database Objects. (line 11) * commit() (sqlite3.Connection method): Connection Objects. (line 32) * common (filecmp.dircmp attribute): The dircmp class. (line 59) * Common Gateway Interface: cgi — Common Gateway Interface support. (line 8) * commonpath() (in module os.path): os path — Common pathname manipulations. (line 73) * commonprefix() (in module os.path): os path — Common pathname manipulations. (line 88) * common_dirs (filecmp.dircmp attribute): The dircmp class. (line 71) * common_files (filecmp.dircmp attribute): The dircmp class. (line 75) * common_funny (filecmp.dircmp attribute): The dircmp class. (line 79) * common_types (in module mimetypes): mimetypes — Map filenames to MIME types. (line 144) * communicate() (asyncio.asyncio.subprocess.Process method): Interacting with Subprocesses. (line 50) * communicate() (subprocess.Popen method): Popen Objects. (line 35) * compare() (decimal.Context method): Context objects. (line 242) * compare() (decimal.Decimal method): Decimal objects. (line 147) * compare() (difflib.Differ method): Differ Objects. (line 38) * compare_digest() (in module hmac): hmac — Keyed-Hashing for Message Authentication. (line 109) * compare_digest() (in module secrets): Other functions. (line 6) * compare_networks() (ipaddress.IPv4Network method): Network objects. (line 234) * compare_networks() (ipaddress.IPv6Network method): Network objects. (line 348) * COMPARE_OP (opcode): Python Bytecode Instructions. (line 630) * compare_signal() (decimal.Context method): Context objects. (line 246) * compare_signal() (decimal.Decimal method): Decimal objects. (line 158) * compare_to() (tracemalloc.Snapshot method): Snapshot. (line 13) * compare_total() (decimal.Context method): Context objects. (line 250) * compare_total() (decimal.Decimal method): Decimal objects. (line 165) * compare_total_mag() (decimal.Context method): Context objects. (line 254) * compare_total_mag() (decimal.Decimal method): Decimal objects. (line 190) * comparison: Comparisons. (line 6) * comparisons: Basic customization. (line 180) * COMPARISON_FLAGS (in module doctest): Option Flags. (line 115) * Compat32 (class in email.policy): email policy Policy Objects. (line 547) * compat32 (in module email.policy): email policy Policy Objects. (line 602) * Compile (class in codeop): codeop — Compile Python code. (line 55) * compile() (built-in function): Built-in Functions. (line 243) * compile() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 269) * compile() (in module py_compile): py_compile — Compile Python source files. (line 24) * compile() (in module re): Module Contents. (line 14) * compile() (parser.ST method): ST Objects. (line 17) * compileall (module): compileall — Byte-compile Python libraries. (line 6) * compileall command line option; -b: Command-line use. (line 52) * compileall command line option; -d destdir: Command-line use. (line 32) * compileall command line option; -f: Command-line use. (line 22) * compileall command line option; -i list: Command-line use. (line 46) * compileall command line option; –invalidation-mode [timestamp|checked-hash|unchecked-hash]: Command-line use. (line 73) * compileall command line option; -j N: Command-line use. (line 67) * compileall command line option; -l: Command-line use. (line 17) * compileall command line option; -q: Command-line use. (line 26) * compileall command line option; -r: Command-line use. (line 60) * compileall command line option; -x regex: Command-line use. (line 40) * compileall command line option; directory ...: Command-line use. (line 9) * compileall command line option; file ...: Command-line use. (line 9) * compilest() (in module parser): Converting ST Objects. (line 43) * compile_command() (in module code): code — Interpreter base classes. (line 47) * compile_command() (in module codeop): codeop — Compile Python code. (line 29) * compile_dir() (in module compileall): Public functions. (line 6) * compile_file() (in module compileall): Public functions. (line 78) * compile_path() (in module compileall): Public functions. (line 127) * complete() (rlcompleter.Completer method): Completer Objects. (line 8) * completedefault() (cmd.Cmd method): Cmd Objects. (line 80) * CompletedProcess (class in subprocess): Using the subprocess Module. (line 91) * complete_statement() (in module sqlite3): Module functions and constants. (line 147) * complex (built-in class): Built-in Functions. (line 326) * Complex (class in numbers): The numeric tower. (line 6) * complex literal: Numeric literals. (line 6) * complex number: Glossary. (line 239) * complex number; literals: Numeric Types — int float complex. (line 19) * complex; number: The standard type hierarchy. (line 119) * compound; statement: Compound statements. (line 6) * comprehensions: Displays for lists sets and dictionaries. (line 6) * compress() (bz2.BZ2Compressor method): Incremental de compression. (line 15) * compress() (in module bz2): One-shot de compression. (line 6) * compress() (in module gzip): gzip — Support for gzip files. (line 172) * compress() (in module itertools): Itertool functions. (line 212) * compress() (in module lzma): Compressing and decompressing data in memory. (line 183) * compress() (in module zlib): zlib — Compression compatible with gzip. (line 45) * compress() (lzma.LZMACompressor method): Compressing and decompressing data in memory. (line 81) * compress() (zlib.Compress method): zlib — Compression compatible with gzip. (line 199) * compressed (ipaddress.IPv4Address attribute): Address objects. (line 52) * compressed (ipaddress.IPv4Network attribute): Network objects. (line 107) * compressed (ipaddress.IPv6Address attribute): Address objects. (line 147) * compressed (ipaddress.IPv6Network attribute): Network objects. (line 316) * compression() (ssl.SSLSocket method): SSL Sockets. (line 227) * CompressionError: tarfile — Read and write tar archive files. (line 191) * compressobj() (in module zlib): zlib — Compression compatible with gzip. (line 60) * compress_size (zipfile.ZipInfo attribute): ZipInfo Objects. (line 139) * compress_type (zipfile.ZipInfo attribute): ZipInfo Objects. (line 84) * COMSPEC: Process Management. (line 664) * COMSPEC <1>: Popen Constructor. (line 90) * concat() (in module operator): operator — Standard operators as functions. (line 172) * concatenation; operation: Common Sequence Operations. (line 21) * concurrent.futures (module): concurrent futures — Launching parallel tasks. (line 6) * Condition (class in asyncio): Condition. (line 6) * Condition (class in multiprocessing): Synchronization primitives. (line 32) * Condition (class in threading): Condition Objects. (line 72) * condition (pdb command): Debugger Commands. (line 119) * condition() (msilib.Control method): GUI classes. (line 24) * Condition() (multiprocessing.managers.SyncManager method): Managers. (line 155) * Conditional; expression: Boolean operations. (line 6) * conditional; expression: Conditional expressions. (line 6) * ConfigParser (class in configparser): ConfigParser Objects. (line 6) * configparser (module): configparser — Configuration file parser. (line 6) * configuration information: sysconfig — Provide access to Python’s configuration information. (line 10) * configuration; file: configparser — Configuration file parser. (line 8) * configure() (tkinter.ttk.Style method): Ttk Styling. (line 24) * configure_mock() (unittest.mock.Mock method): The Mock Class. (line 242) * confstr() (in module os): Miscellaneous System Information. (line 6) * confstr_names (in module os): Miscellaneous System Information. (line 28) * conjugate() (complex number method): Numeric Types — int float complex. (line 94) * conjugate() (decimal.Decimal method): Decimal objects. (line 202) * conjugate() (numbers.Complex method): The numeric tower. (line 23) * conn (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 48) * connect() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 194) * connect() (ftplib.FTP method): FTP Objects. (line 22) * connect() (http.client.HTTPConnection method): HTTPConnection Objects. (line 105) * connect() (in module sqlite3): Module functions and constants. (line 55) * connect() (multiprocessing.managers.BaseManager method): Managers. (line 59) * connect() (smtplib.SMTP method): SMTP Objects. (line 33) * connect() (socket.socket method): Socket Objects. (line 60) * Connection (class in multiprocessing.connection): Connection Objects<2>. (line 13) * Connection (class in sqlite3): Connection Objects. (line 6) * connection (sqlite3.Cursor attribute): Cursor Objects. (line 230) * ConnectionAbortedError: OS exceptions. (line 44) * ConnectionError: OS exceptions. (line 29) * ConnectionRefusedError: OS exceptions. (line 50) * ConnectionResetError: OS exceptions. (line 56) * connection_lost() (asyncio.BaseProtocol method): Base Protocol. (line 23) * connection_made() (asyncio.BaseProtocol method): Base Protocol. (line 15) * ConnectRegistry() (in module winreg): Functions<11>. (line 17) * connect_accepted_socket() (asyncio.loop method): Creating network servers. (line 116) * connect_ex() (socket.socket method): Socket Objects. (line 82) * connect_read_pipe() (asyncio.loop method): Working with pipes. (line 6) * connect_write_pipe() (asyncio.loop method): Working with pipes. (line 22) * const (optparse.Option attribute): Option attributes. (line 50) * constant: Literals. (line 6) * constructor() (in module copyreg): copyreg — Register pickle support functions. (line 17) * consumed (asyncio.LimitOverrunError attribute): Exceptions<9>. (line 65) * container: Objects values and types. (line 67) * container <1>: The standard type hierarchy. (line 573) * Container (class in collections.abc): Collections Abstract Base Classes. (line 104) * Container (class in typing): Classes functions and decorators. (line 191) * container; iteration over: Iterator Types. (line 6) * contains() (in module operator): operator — Standard operators as functions. (line 177) * ContentDispositionHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 280) * ContentHandler (class in xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 18) * ContentManager (class in email.contentmanager): email contentmanager Managing MIME Content. (line 12) * contents (ctypes._Pointer attribute): Arrays and pointers. (line 50) * contents() (importlib.abc.ResourceReader method): importlib abc – Abstract base classes related to import. (line 340) * contents() (in module importlib.resources): importlib resources – Resources. (line 127) * ContentTooShortError: urllib error — Exception classes raised by urllib request. (line 56) * ContentTransferEncoding (class in email.headerregistry): email headerregistry Custom Header Objects. (line 290) * ContentTypeHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 267) * content_disposition (email.headerregistry.ContentDispositionHeader attribute): email headerregistry Custom Header Objects. (line 285) * content_manager (email.policy.EmailPolicy attribute): email policy Policy Objects. (line 402) * content_type (email.headerregistry.ContentTypeHeader attribute): email headerregistry Custom Header Objects. (line 272) * Context (class in contextvars): Manual Context Management. (line 20) * Context (class in decimal): Context objects. (line 96) * context (ssl.SSLSocket attribute): SSL Sockets. (line 318) * context management protocol: Context Manager Types. (line 6) * context manager: With Statement Context Managers. (line 14) * context manager <1>: Context Manager Types. (line 6) * context manager <2>: Glossary. (line 253) * context variable: Glossary. (line 259) * ContextDecorator (class in contextlib): Utilities. (line 264) * contextlib (module): contextlib — Utilities for with-statement contexts. (line 6) * ContextManager (class in typing): Classes functions and decorators. (line 332) * contextmanager() (in module contextlib): Utilities. (line 30) * ContextVar (class in contextvars): Context Variables. (line 6) * contextvars (module): contextvars — Context Variables. (line 6) * contextvars.Token (class in contextvars): Context Variables. (line 75) * context_diff() (in module difflib): difflib — Helpers for computing deltas. (line 157) * contiguous: shape strides suboffsets. (line 26) * contiguous <1>: Glossary. (line 269) * contiguous (memoryview attribute): Memory Views. (line 482) * continue (pdb command): Debugger Commands. (line 192) * Control (class in msilib): GUI classes. (line 11) * Control (class in tkinter.tix): Basic Widgets. (line 24) * control() (msilib.Dialog method): GUI classes. (line 47) * control() (select.kqueue method): Kqueue Objects. (line 22) * controlnames (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 237) * controls() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 23) * ConversionError: Exceptions<6>. (line 13) * convert_arg_line_to_args() (argparse.ArgumentParser method): Customizing file parsing. (line 6) * convert_field() (string.Formatter method): Custom String Formatting. (line 108) * convert_path() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 54) * Cookie (class in http.cookiejar): http cookiejar — Cookie handling for HTTP clients. (line 109) * CookieError: http cookies — HTTP state management. (line 33) * CookieJar (class in http.cookiejar): http cookiejar — Cookie handling for HTTP clients. (line 45) * cookiejar (urllib.request.HTTPCookieProcessor attribute): HTTPCookieProcessor Objects. (line 8) * CookiePolicy (class in http.cookiejar): http cookiejar — Cookie handling for HTTP clients. (line 73) * Coordinated Universal Time: time — Time access and conversions. (line 40) * Copy: Help menu Shell and Editor. (line 30) * copy (module): copy — Shallow and deep copy operations. (line 6) * copy() (collections.deque method): deque objects. (line 47) * copy() (contextvars.Context method): Manual Context Management. (line 70) * copy() (decimal.Context method): Context objects. (line 162) * copy() (dict method): Mapping Types — dict. (line 146) * copy() (frozenset method): Set Types — set frozenset. (line 123) * copy() (hashlib.hash method): Hash algorithms. (line 141) * copy() (hmac.HMAC method): hmac — Keyed-Hashing for Message Authentication. (line 82) * copy() (http.cookies.Morsel method): Morsel Objects. (line 102) * copy() (imaplib.IMAP4 method): IMAP4 Objects. (line 68) * copy() (in module copy): copy — Shallow and deep copy operations. (line 18) * copy() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 83) * copy() (in module shutil): Directory and files operations. (line 121) * copy() (pipes.Template method): Template Objects. (line 48) * copy() (sequence method): Mutable Sequence Types. (line 16) * copy() (types.MappingProxyType method): Standard Interpreter Types. (line 245) * copy() (zlib.Compress method): zlib — Compression compatible with gzip. (line 220) * copy() (zlib.Decompress method): zlib — Compression compatible with gzip. (line 289) * copy2() (in module shutil): Directory and files operations. (line 152) * copy; protocol: Pickling Class Instances. (line 93) * copyfile() (in module shutil): Directory and files operations. (line 17) * copyfileobj() (in module shutil): Directory and files operations. (line 6) * copying files: shutil — High-level file operations. (line 8) * copymode() (in module shutil): Directory and files operations. (line 59) * copyreg (module): copyreg — Register pickle support functions. (line 6) * copyright (built-in variable): Constants added by the site module. (line 18) * copyright (in module sys): sys — System-specific parameters and functions. (line 153) * copyright (in module sys) <1>: Process-wide parameters. (line 188) * copysign() (in module math): Number-theoretic and representation functions. (line 30) * copystat() (in module shutil): Directory and files operations. (line 77) * copytree() (in module shutil): Directory and files operations. (line 191) * copy_abs() (decimal.Context method): Context objects. (line 259) * copy_abs() (decimal.Decimal method): Decimal objects. (line 207) * copy_context() (in module contextvars): Manual Context Management. (line 6) * copy_decimal() (decimal.Context method): Context objects. (line 166) * copy_file() (in module distutils.file_util): distutils file_util — Single file operations. (line 9) * copy_file_range() (in module os): File Descriptor Operations. (line 44) * copy_location() (in module ast): ast Helpers. (line 96) * copy_negate() (decimal.Context method): Context objects. (line 263) * copy_negate() (decimal.Decimal method): Decimal objects. (line 213) * copy_sign() (decimal.Context method): Context objects. (line 267) * copy_sign() (decimal.Decimal method): Decimal objects. (line 219) * copy_tree() (in module distutils.dir_util): distutils dir_util — Directory tree operations. (line 32) * coroutine: Special method lookup. (line 74) * coroutine <1>: Yield expressions. (line 51) * coroutine <2>: Glossary. (line 280) * Coroutine (class in collections.abc): Collections Abstract Base Classes. (line 212) * Coroutine (class in typing): Classes functions and decorators. (line 304) * coroutine function: Glossary. (line 288) * coroutine() (in module asyncio): Generator-based Coroutines. (line 16) * coroutine() (in module types): Coroutine Utility Functions. (line 6) * coroutine; function: The standard type hierarchy. (line 458) * CoroutineType (in module types): Standard Interpreter Types. (line 36) * cos() (in module cmath): Trigonometric functions<2>. (line 25) * cos() (in module math): Trigonometric functions. (line 28) * cosh() (in module cmath): Hyperbolic functions<2>. (line 26) * cosh() (in module math): Hyperbolic functions. (line 21) * count (tracemalloc.Statistic attribute): Statistic. (line 15) * count (tracemalloc.StatisticDiff attribute): StatisticDiff. (line 15) * count() (array.array method): array — Efficient arrays of numeric values. (line 144) * count() (bytearray method): Bytes and Bytearray Operations. (line 36) * count() (bytes method): Bytes and Bytearray Operations. (line 36) * count() (collections.deque method): deque objects. (line 53) * count() (in module itertools): Itertool functions. (line 225) * count() (multiprocessing.shared_memory.ShareableList method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 264) * count() (sequence method): Common Sequence Operations. (line 21) * count() (str method): String Methods<2>. (line 55) * Counter (class in collections): Counter objects. (line 23) * Counter (class in typing): Classes functions and decorators. (line 374) * countOf() (in module operator): operator — Standard operators as functions. (line 183) * countTestCases() (unittest.TestCase method): Test cases. (line 712) * countTestCases() (unittest.TestSuite method): Grouping tests. (line 55) * count_diff (tracemalloc.StatisticDiff attribute): StatisticDiff. (line 20) * CoverageResults (class in trace): Programmatic Interface. (line 47) * co_argcount (code object attribute): The standard type hierarchy. (line 662) * CO_ASYNC_GENERATOR (in module inspect): Code Objects Bit Flags. (line 56) * co_cellvars (code object attribute): The standard type hierarchy. (line 662) * co_code (code object attribute): The standard type hierarchy. (line 662) * co_consts (code object attribute): The standard type hierarchy. (line 662) * CO_COROUTINE (in module inspect): Code Objects Bit Flags. (line 39) * co_filename (code object attribute): The standard type hierarchy. (line 662) * co_firstlineno (code object attribute): The standard type hierarchy. (line 662) * co_flags (code object attribute): The standard type hierarchy. (line 662) * co_freevars (code object attribute): The standard type hierarchy. (line 662) * CO_FUTURE_DIVISION (C variable): The Very High Level Layer. (line 422) * CO_GENERATOR (in module inspect): Code Objects Bit Flags. (line 30) * CO_ITERABLE_COROUTINE (in module inspect): Code Objects Bit Flags. (line 47) * co_kwonlyargcount (code object attribute): The standard type hierarchy. (line 662) * co_lnotab (code object attribute): The standard type hierarchy. (line 662) * co_name (code object attribute): The standard type hierarchy. (line 662) * co_names (code object attribute): The standard type hierarchy. (line 662) * CO_NESTED (in module inspect): Code Objects Bit Flags. (line 26) * CO_NEWLOCALS (in module inspect): Code Objects Bit Flags. (line 13) * co_nlocals (code object attribute): The standard type hierarchy. (line 662) * CO_NOFREE (in module inspect): Code Objects Bit Flags. (line 35) * CO_OPTIMIZED (in module inspect): Code Objects Bit Flags. (line 9) * co_posonlyargcount (code object attribute): The standard type hierarchy. (line 662) * co_stacksize (code object attribute): The standard type hierarchy. (line 662) * CO_VARARGS (in module inspect): Code Objects Bit Flags. (line 18) * CO_VARKEYWORDS (in module inspect): Code Objects Bit Flags. (line 22) * co_varnames (code object attribute): The standard type hierarchy. (line 662) * CPP: New Improved and Deprecated Modules<4>. (line 59) * CPPFLAGS: New Improved and Deprecated Modules<4>. (line 59) * cProfile (module): profile and cProfile Module Reference. (line 6) * CPU time: Functions<2>. (line 200) * CPU time <1>: Functions<2>. (line 479) * cpu_count() (in module multiprocessing): Miscellaneous<3>. (line 13) * cpu_count() (in module os): Miscellaneous System Information. (line 37) * CPython: Glossary. (line 296) * cpython_only() (in module test.support): test support — Utilities for the Python test suite. (line 633) * crawl_delay() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 50) * CRC (zipfile.ZipInfo attribute): ZipInfo Objects. (line 135) * crc32() (in module binascii): binascii — Convert between binary and ASCII. (line 113) * crc32() (in module zlib): zlib — Compression compatible with gzip. (line 115) * crc_hqx() (in module binascii): binascii — Convert between binary and ASCII. (line 106) * create() (imaplib.IMAP4 method): IMAP4 Objects. (line 72) * create() (in module venv): API<2>. (line 155) * create() (venv.EnvBuilder method): API<2>. (line 49) * createAttribute() (xml.dom.Document method): Document Objects. (line 46) * createAttributeNS() (xml.dom.Document method): Document Objects. (line 53) * createComment() (xml.dom.Document method): Document Objects. (line 34) * createDocument() (xml.dom.DOMImplementation method): DOMImplementation Objects. (line 16) * createDocumentType() (xml.dom.DOMImplementation method): DOMImplementation Objects. (line 26) * createElement() (xml.dom.Document method): Document Objects. (line 14) * createElementNS() (xml.dom.Document method): Document Objects. (line 21) * createfilehandler() (tkinter.Widget.tk method): File Handlers. (line 27) * CreateKey() (in module winreg): Functions<11>. (line 35) * CreateKeyEx() (in module winreg): Functions<11>. (line 63) * createLock() (logging.Handler method): Handler Objects. (line 20) * createLock() (logging.NullHandler method): NullHandler. (line 24) * createProcessingInstruction() (xml.dom.Document method): Document Objects. (line 40) * CreateRecord() (in module msilib): msilib — Read and write Microsoft Installer files. (line 55) * createSocket() (logging.handlers.SocketHandler method): SocketHandler. (line 72) * createTextNode() (xml.dom.Document method): Document Objects. (line 28) * create_aggregate() (sqlite3.Connection method): Connection Objects. (line 109) * create_archive() (in module zipapp): Python API. (line 8) * create_autospec() (in module unittest.mock): create_autospec. (line 6) * CREATE_BREAKAWAY_FROM_JOB (in module subprocess): Windows Constants. (line 124) * create_collation() (sqlite3.Connection method): Connection Objects. (line 147) * create_configuration() (venv.EnvBuilder method): API<2>. (line 86) * create_connection() (asyncio.loop method): Opening network connections. (line 6) * create_connection() (in module socket): Creating sockets. (line 79) * create_datagram_endpoint() (asyncio.loop method): Opening network connections. (line 134) * create_decimal() (decimal.Context method): Context objects. (line 170) * create_decimal_from_float() (decimal.Context method): Context objects. (line 194) * create_default_context() (in module ssl): Context creation. (line 9) * CREATE_DEFAULT_ERROR_MODE (in module subprocess): Windows Constants. (line 114) * create_empty_file() (in module test.support): test support — Utilities for the Python test suite. (line 237) * create_function() (sqlite3.Connection method): Connection Objects. (line 73) * create_future() (asyncio.loop method): Creating Futures and Tasks. (line 6) * create_module (C function): Multi-phase initialization. (line 67) * create_module() (importlib.abc.Loader method): importlib abc – Abstract base classes related to import. (line 170) * create_module() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 319) * CREATE_NEW_CONSOLE (in module subprocess): Windows Constants. (line 38) * CREATE_NEW_PROCESS_GROUP (in module subprocess): Windows Constants. (line 43) * CREATE_NO_WINDOW (in module subprocess): Windows Constants. (line 99) * create_server() (asyncio.loop method): Creating network servers. (line 6) * create_server() (in module socket): Creating sockets. (line 103) * create_shortcut() (built-in function): The Postinstallation script. (line 62) * create_socket() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 184) * create_static_lib() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 323) * create_stats() (profile.Profile method): profile and cProfile Module Reference. (line 86) * create_string_buffer() (in module ctypes): Utility functions. (line 40) * create_subprocess_exec() (in module asyncio): Creating Subprocesses. (line 6) * create_subprocess_shell() (in module asyncio): Creating Subprocesses. (line 25) * create_system (zipfile.ZipInfo attribute): ZipInfo Objects. (line 99) * create_task() (asyncio.loop method): Creating Futures and Tasks. (line 17) * create_task() (in module asyncio): Creating Tasks. (line 6) * create_tree() (in module distutils.dir_util): distutils dir_util — Directory tree operations. (line 21) * create_unicode_buffer() (in module ctypes): Utility functions. (line 58) * create_unix_connection() (asyncio.loop method): Opening network connections. (line 212) * create_unix_server() (asyncio.loop method): Creating network servers. (line 94) * create_version (zipfile.ZipInfo attribute): ZipInfo Objects. (line 103) * credits (built-in variable): Constants added by the site module. (line 18) * critical() (in module logging): Module-Level Functions. (line 138) * critical() (logging.Logger method): Logger Objects. (line 234) * CRNCYSTR (in module locale): locale — Internationalization services. (line 257) * cross() (in module audioop): audioop — Manipulate raw audio data. (line 74) * crypt (module): crypt — Function to check Unix passwords. (line 6) * crypt() (in module crypt): Module Functions<2>. (line 8) * crypt(3): crypt — Function to check Unix passwords. (line 8) * crypt(3) <1>: crypt — Function to check Unix passwords. (line 16) * crypt(3) <2>: Module Functions<2>. (line 32) * cryptography: Cryptographic Services. (line 6) * cssclasses (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 193) * cssclasses_weekday_head (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 213) * cssclass_month (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 227) * cssclass_month_head (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 220) * cssclass_noday (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 206) * cssclass_year (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 234) * cssclass_year_head (calendar.HTMLCalendar attribute): calendar — General calendar-related functions. (line 241) * csv: csv — CSV File Reading and Writing. (line 8) * csv (module): csv — CSV File Reading and Writing. (line 6) * cte (email.headerregistry.ContentTransferEncoding attribute): email headerregistry Custom Header Objects. (line 294) * ctermid() (in module os): Process Parameters. (line 9) * cte_type (email.policy.Policy attribute): email policy Policy Objects. (line 159) * ctime() (datetime.date method): date Objects. (line 251) * ctime() (datetime.datetime method): datetime Objects. (line 681) * ctime() (in module time): Functions<2>. (line 85) * ctrl() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 213) * CTRL_BREAK_EVENT (in module signal): Module contents<2>. (line 155) * CTRL_C_EVENT (in module signal): Module contents<2>. (line 146) * ctypes (module): ctypes — A foreign function library for Python. (line 6) * curdir (in module os): Miscellaneous System Information. (line 81) * currency() (in module locale): locale — Internationalization services. (line 420) * current() (tkinter.ttk.Combobox method): ttk Combobox. (line 8) * CurrentByteIndex (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 157) * CurrentColumnNumber (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 161) * currentframe() (in module inspect): The interpreter stack. (line 74) * CurrentLineNumber (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 165) * current_process() (in module multiprocessing): Miscellaneous<3>. (line 28) * current_task() (asyncio.Task class method): Task Object. (line 244) * current_task() (in module asyncio): Introspection. (line 6) * current_thread() (in module threading): threading — Thread-based parallelism. (line 39) * curses (module): curses — Terminal handling for character-cell displays. (line 6) * curses.ascii (module): curses ascii — Utilities for ASCII characters. (line 6) * curses.panel (module): curses panel — A panel stack extension for curses. (line 6) * curses.textpad (module): curses textpad — Text input widget for curses programs. (line 6) * Cursor (class in sqlite3): Cursor Objects. (line 6) * cursor() (sqlite3.Connection method): Connection Objects. (line 26) * cursyncup() (curses.window method): Window Objects. (line 172) * curs_set() (in module curses): Functions<3>. (line 61) * customize_compiler() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 84) * Cut: Help menu Shell and Editor. (line 30) * cwd() (ftplib.FTP method): FTP Objects. (line 213) * cwd() (pathlib.Path class method): Methods<2>. (line 17) * cycle() (in module itertools): Itertool functions. (line 247) * Cyclic Redundancy Check: zlib — Compression compatible with gzip. (line 117) * c_bool (class in ctypes): Fundamental data types<2>. (line 202) * C_BUILTIN (in module imp): imp — Access the import internals. (line 333) * c_byte (class in ctypes): Fundamental data types<2>. (line 45) * c_char (class in ctypes): Fundamental data types<2>. (line 51) * c_char_p (class in ctypes): Fundamental data types<2>. (line 58) * c_contiguous (memoryview attribute): Memory Views. (line 468) * c_double (class in ctypes): Fundamental data types<2>. (line 65) * C_EXTENSION (in module imp): imp — Access the import internals. (line 321) * c_float (class in ctypes): Fundamental data types<2>. (line 76) * c_int (class in ctypes): Fundamental data types<2>. (line 81) * c_int16 (class in ctypes): Fundamental data types<2>. (line 93) * c_int32 (class in ctypes): Fundamental data types<2>. (line 98) * c_int64 (class in ctypes): Fundamental data types<2>. (line 103) * c_int8 (class in ctypes): Fundamental data types<2>. (line 88) * c_long (class in ctypes): Fundamental data types<2>. (line 108) * c_longdouble (class in ctypes): Fundamental data types<2>. (line 70) * c_longlong (class in ctypes): Fundamental data types<2>. (line 113) * c_short (class in ctypes): Fundamental data types<2>. (line 119) * c_size_t (class in ctypes): Fundamental data types<2>. (line 124) * c_ssize_t (class in ctypes): Fundamental data types<2>. (line 128) * c_ubyte (class in ctypes): Fundamental data types<2>. (line 134) * c_uint (class in ctypes): Fundamental data types<2>. (line 140) * c_uint16 (class in ctypes): Fundamental data types<2>. (line 152) * c_uint32 (class in ctypes): Fundamental data types<2>. (line 157) * c_uint64 (class in ctypes): Fundamental data types<2>. (line 162) * c_uint8 (class in ctypes): Fundamental data types<2>. (line 147) * c_ulong (class in ctypes): Fundamental data types<2>. (line 167) * c_ulonglong (class in ctypes): Fundamental data types<2>. (line 172) * c_ushort (class in ctypes): Fundamental data types<2>. (line 178) * c_void_p (class in ctypes): Fundamental data types<2>. (line 184) * c_wchar (class in ctypes): Fundamental data types<2>. (line 189) * c_wchar_p (class in ctypes): Fundamental data types<2>. (line 196) * daemon (multiprocessing.Process attribute): Process and exceptions. (line 87) * daemon (threading.Thread attribute): Thread Objects. (line 184) * dangling; else: Compound statements. (line 54) * data: Objects values and types. (line 6) * Data (class in plistlib): plistlib — Generate and parse Mac OS X plist files. (line 169) * data (collections.UserDict attribute): UserDict objects. (line 24) * data (collections.UserList attribute): UserList objects. (line 29) * data (collections.UserString attribute): UserString objects. (line 24) * data (select.kevent attribute): Kevent Objects. (line 175) * data (selectors.SelectorKey attribute): Classes<3>. (line 48) * data (urllib.request.Request attribute): Request Objects. (line 39) * data (xml.dom.Comment attribute): Comment Objects. (line 9) * data (xml.dom.ProcessingInstruction attribute): ProcessingInstruction Objects. (line 14) * data (xml.dom.Text attribute): Text and CDATASection Objects. (line 15) * data (xmlrpc.client.Binary attribute): Binary Objects. (line 12) * data() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 33) * data; tabular: csv — CSV File Reading and Writing. (line 8) * data; type: The standard type hierarchy. (line 6) * DatabaseError: Exceptions<4>. (line 15) * databases: dbm dumb — Portable DBM implementation. (line 8) * dataclass() (in module dataclasses): Module-level decorators classes and functions. (line 6) * dataclasses (module): dataclasses — Data Classes. (line 6) * DatagramHandler (class in logging.handlers): DatagramHandler. (line 10) * DatagramProtocol (class in asyncio): Base Protocols. (line 20) * DatagramRequestHandler (class in socketserver): Request Handler Objects. (line 42) * DatagramTransport (class in asyncio): Transports Hierarchy. (line 43) * datagram_received() (asyncio.DatagramProtocol method): Datagram Protocols. (line 9) * DataHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 420) * data_open() (urllib.request.DataHandler method): DataHandler Objects. (line 6) * data_received() (asyncio.Protocol method): Streaming Protocols. (line 13) * date (class in datetime): date Objects. (line 13) * date() (datetime.datetime method): datetime Objects. (line 391) * date() (nntplib.NNTP method): Methods<3>. (line 298) * DateHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 136) * datetime (class in datetime): datetime Objects. (line 17) * DateTime (class in xmlrpc.client): DateTime Objects. (line 6) * datetime (email.headerregistry.DateHeader attribute): email headerregistry Custom Header Objects. (line 145) * datetime (module): datetime — Basic date and time types. (line 6) * date_time (zipfile.ZipInfo attribute): ZipInfo Objects. (line 54) * date_time_string() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 310) * datum: Dictionary displays. (line 6) * day (datetime.date attribute): date Objects. (line 110) * day (datetime.datetime attribute): datetime Objects. (line 272) * daylight (in module time): Timezone Constants. (line 13) * Daylight Saving Time: time — Time access and conversions. (line 44) * day_abbr (in module calendar): calendar — General calendar-related functions. (line 371) * day_name (in module calendar): calendar — General calendar-related functions. (line 366) * DbfilenameShelf (class in shelve): Restrictions. (line 64) * dbm (module): dbm — Interfaces to Unix “databases”. (line 6) * dbm.dumb (module): dbm dumb — Portable DBM implementation. (line 6) * dbm.gnu (module): dbm gnu — GNU’s reinterpretation of dbm. (line 6) * dbm.ndbm (module): dbm ndbm — Interface based on ndbm. (line 6) * dcgettext() (in module locale): Access to message catalogs. (line 10) * deallocation, object: Finalization and De-allocation. (line 6) * debug (imaplib.IMAP4 attribute): IMAP4 Objects. (line 381) * DEBUG (in module re): Module Contents. (line 58) * debug (pdb command): Debugger Commands. (line 335) * debug (shlex.shlex attribute): shlex Objects. (line 162) * debug (zipfile.ZipFile attribute): ZipFile Objects. (line 302) * debug() (in module doctest): Debugging. (line 124) * debug() (in module logging): Module-Level Functions. (line 44) * debug() (logging.Logger method): Logger Objects. (line 118) * debug() (pipes.Template method): Template Objects. (line 16) * debug() (unittest.TestCase method): Test cases. (line 120) * debug() (unittest.TestSuite method): Grouping tests. (line 48) * debugger: Debug menu Shell window only. (line 15) * debugger <1>: sys — System-specific parameters and functions. (line 745) * debugger <2>: sys — System-specific parameters and functions. (line 1310) * debugger; configuration; file: Debugger Commands. (line 37) * debugging: pdb — The Python Debugger. (line 8) * debugging; assertions: The assert statement. (line 6) * DebuggingServer (class in smtpd): DebuggingServer Objects. (line 6) * debuglevel (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 59) * DebugRunner (class in doctest): Debugging. (line 168) * DEBUG_BYTECODE_SUFFIXES (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 20) * DEBUG_COLLECTABLE (in module gc): gc — Garbage Collector interface. (line 273) * DEBUG_LEAK (in module gc): gc — Garbage Collector interface. (line 293) * debug_print() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 511) * DEBUG_SAVEALL (in module gc): gc — Garbage Collector interface. (line 287) * debug_src() (in module doctest): Debugging. (line 147) * DEBUG_STATS (in module gc): gc — Garbage Collector interface. (line 268) * DEBUG_UNCOLLECTABLE (in module gc): gc — Garbage Collector interface. (line 277) * Decimal (class in decimal): Decimal objects. (line 6) * decimal (module): decimal — Decimal fixed point and floating point arithmetic. (line 6) * decimal literal: Numeric literals. (line 6) * decimal() (in module unicodedata): unicodedata — Unicode Database. (line 31) * DecimalException (class in decimal): Signals. (line 28) * decode (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 69) * decode() (bytearray method): Bytes and Bytearray Operations. (line 49) * decode() (bytes method): Bytes and Bytearray Operations. (line 49) * decode() (codecs.Codec method): Stateless Encoding and Decoding. (line 26) * decode() (codecs.IncrementalDecoder method): IncrementalDecoder Objects. (line 28) * decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 205) * decode() (in module codecs): codecs — Codec registry and base classes. (line 34) * decode() (in module quopri): quopri — Encode and decode MIME quoted-printable data. (line 19) * decode() (in module uu): uu — Encode and decode uuencode files. (line 37) * decode() (json.JSONDecoder method): Encoders and Decoders. (line 85) * decode() (xmlrpc.client.Binary method): Binary Objects. (line 20) * decode() (xmlrpc.client.DateTime method): DateTime Objects. (line 13) * decodebytes() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 212) * DecodedGenerator (class in email.generator): email generator Generating MIME documents. (line 232) * decodestring() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 220) * decodestring() (in module quopri): quopri — Encode and decode MIME quoted-printable data. (line 41) * decode_header() (in module email.header): email header Internationalized headers. (line 183) * decode_header() (in module nntplib): Utility functions<2>. (line 8) * decode_params() (in module email.utils): email utils Miscellaneous utilities. (line 204) * decode_rfc2231() (in module email.utils): email utils Miscellaneous utilities. (line 174) * decode_source() (in module importlib.util): importlib util – Utility code for importers. (line 72) * decomposition() (in module unicodedata): unicodedata — Unicode Database. (line 75) * decompress() (bz2.BZ2Decompressor method): Incremental de compression. (line 45) * decompress() (in module bz2): One-shot de compression. (line 16) * decompress() (in module gzip): gzip — Support for gzip files. (line 183) * decompress() (in module lzma): Compressing and decompressing data in memory. (line 192) * decompress() (in module zlib): zlib — Compression compatible with gzip. (line 131) * decompress() (lzma.LZMADecompressor method): Compressing and decompressing data in memory. (line 132) * decompress() (zlib.Decompress method): zlib — Compression compatible with gzip. (line 258) * decompressobj() (in module zlib): zlib — Compression compatible with gzip. (line 176) * decorator: Glossary. (line 303) * DEDENT (in module token): token — Constants used with Python parse trees. (line 52) * DEDENT token: Indentation. (line 33) * DEDENT token <1>: Compound statements. (line 54) * dedent() (in module textwrap): textwrap — Text wrapping and filling. (line 65) * deepcopy() (in module copy): copy — Shallow and deep copy operations. (line 22) * default (in module email.policy): email policy Policy Objects. (line 487) * DEFAULT (in module unittest.mock): DEFAULT. (line 6) * default (inspect.Parameter attribute): Introspecting callables with the Signature object. (line 169) * default (optparse.Option attribute): Option attributes. (line 36) * default() (cmd.Cmd method): Cmd Objects. (line 74) * default() (json.JSONEncoder method): Encoders and Decoders. (line 197) * default; parameter; value: Function definitions. (line 53) * DefaultContext (class in decimal): Context objects. (line 72) * DefaultCookiePolicy (class in http.cookiejar): http cookiejar — Cookie handling for HTTP clients. (line 78) * defaultdict (class in collections): defaultdict objects. (line 6) * DefaultDict (class in typing): Classes functions and decorators. (line 360) * DefaultEventLoopPolicy (class in asyncio): Policy Objects. (line 50) * DefaultHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 310) * DefaultHandlerExpand() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 317) * defaults() (configparser.ConfigParser method): ConfigParser Objects. (line 77) * DefaultSelector (class in selectors): Classes<3>. (line 161) * defaultTestLoader (in module unittest): Loading and running tests. (line 431) * defaultTestResult() (unittest.TestCase method): Test cases. (line 717) * DEFAULT_BUFFER_SIZE (in module io): High-level Module Interface. (line 6) * default_bufsize (in module xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees. (line 104) * default_exception_handler() (asyncio.loop method): Error Handling API. (line 26) * default_factory (collections.defaultdict attribute): defaultdict objects. (line 49) * DEFAULT_FORMAT (in module tarfile): tarfile — Read and write tar archive files. (line 234) * DEFAULT_IGNORES (in module filecmp): The dircmp class. (line 105) * default_open() (urllib.request.BaseHandler method): BaseHandler Objects. (line 30) * DEFAULT_PROTOCOL (in module pickle): Module Interface. (line 21) * default_timer() (in module timeit): Python Interface. (line 32) * defects (email.headerregistry.BaseHeader attribute): email headerregistry Custom Header Objects. (line 52) * defects (email.message.EmailMessage attribute): email message Representing an email message. (line 712) * defects (email.message.Message attribute): email message Message Representing an email message using the compat32 API. (line 724) * define_macro() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 162) * defpath (in module os): Miscellaneous System Information. (line 121) * DefragResult (class in urllib.parse): Structured Parse Results. (line 40) * DefragResultBytes (class in urllib.parse): Structured Parse Results. (line 65) * def_prog_mode() (in module curses): Functions<3>. (line 70) * def_shell_mode() (in module curses): Functions<3>. (line 77) * degrees() (in module math): Angular conversion. (line 6) * degrees() (in module turtle): Settings for measurement. (line 6) * delattr() (built-in function): Built-in Functions. (line 358) * delay() (in module turtle): Animation control. (line 6) * delayload (http.cookiejar.FileCookieJar attribute): CookieJar and FileCookieJar Objects. (line 158) * delay_output() (in module curses): Functions<3>. (line 85) * delch() (curses.window method): Window Objects. (line 177) * dele() (poplib.POP3 method): POP3 Objects. (line 67) * delete() (ftplib.FTP method): FTP Objects. (line 206) * delete() (imaplib.IMAP4 method): IMAP4 Objects. (line 76) * delete() (tkinter.ttk.Treeview method): ttk Treeview. (line 79) * deleteacl() (imaplib.IMAP4 method): IMAP4 Objects. (line 80) * deletefilehandler() (tkinter.Widget.tk method): File Handlers. (line 37) * DeleteKey() (in module winreg): Functions<11>. (line 102) * DeleteKeyEx() (in module winreg): Functions<11>. (line 124) * deleteln() (curses.window method): Window Objects. (line 181) * deleteMe() (bdb.Breakpoint method): bdb — Debugger framework. (line 41) * DeleteValue() (in module winreg): Functions<11>. (line 165) * DELETE_ATTR (opcode): Python Bytecode Instructions. (line 515) * DELETE_DEREF (opcode): Python Bytecode Instructions. (line 750) * DELETE_FAST (opcode): Python Bytecode Instructions. (line 720) * DELETE_GLOBAL (opcode): Python Bytecode Instructions. (line 523) * DELETE_NAME (opcode): Python Bytecode Instructions. (line 489) * DELETE_SUBSCR (opcode): Python Bytecode Instructions. (line 254) * deletion; target: The del statement<2>. (line 6) * deletion; target; list: The del statement<2>. (line 6) * delimiter (csv.Dialect attribute): Dialects and Formatting Parameters. (line 19) * delimiters: Delimiters. (line 6) * delitem() (in module operator): operator — Standard operators as functions. (line 187) * deliver_challenge() (in module multiprocessing.connection): Listeners and Clients. (line 15) * delocalize() (in module locale): locale — Internationalization services. (line 441) * del_param() (email.message.EmailMessage method): email message Representing an email message. (line 383) * del_param() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 543) * demo_app() (in module wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server. (line 36) * denominator (fractions.Fraction attribute): fractions — Rational numbers. (line 94) * denominator (numbers.Rational attribute): The numeric tower. (line 51) * DeprecationWarning: Warnings. (line 17) * deque (class in collections): deque objects. (line 6) * Deque (class in typing): Classes functions and decorators. (line 247) * dequeue() (logging.handlers.QueueListener method): QueueListener. (line 46) * derwin() (curses.window method): Window Objects. (line 186) * DER_cert_to_PEM_cert() (in module ssl): Certificate handling. (line 91) * descrgetfunc (C type): Slot Type typedefs. (line 78) * description (inspect.Parameter.kind attribute): Introspecting callables with the Signature object. (line 234) * description (sqlite3.Cursor attribute): Cursor Objects. (line 220) * description() (nntplib.NNTP method): Methods<3>. (line 149) * descriptions() (nntplib.NNTP method): Methods<3>. (line 135) * descriptor: Glossary. (line 325) * descrsetfunc (C type): Slot Type typedefs. (line 83) * dest (optparse.Option attribute): Option attributes. (line 27) * destructor: Basic customization. (line 56) * destructor <1>: Assignment statements. (line 73) * destructor (C type): Slot Type typedefs. (line 24) * detach() (io.BufferedIOBase method): I/O Base Classes. (line 256) * detach() (io.TextIOBase method): Text I/O<2>. (line 37) * detach() (socket.socket method): Socket Objects. (line 94) * detach() (tkinter.ttk.Treeview method): ttk Treeview. (line 85) * detach() (weakref.finalize method): weakref — Weak references. (line 259) * Detach() (winreg.PyHKEY method): Registry Handle Objects. (line 40) * DETACHED_PROCESS (in module subprocess): Windows Constants. (line 106) * detect_api_mismatch() (in module test.support): test support — Utilities for the Python test suite. (line 930) * detect_encoding() (in module tokenize): Tokenizing Input. (line 77) * detect_language() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 198) * deterministic profiling: Introduction to the profilers. (line 6) * device_encoding() (in module os): File Descriptor Operations. (line 67) * devnull (in module os): Miscellaneous System Information. (line 136) * DEVNULL (in module subprocess): Using the subprocess Module. (line 132) * devpoll() (in module select): select — Waiting for I/O completion. (line 31) * DevpollSelector (class in selectors): Classes<3>. (line 184) * dgettext() (in module gettext): GNU gettext API. (line 49) * dgettext() (in module locale): Access to message catalogs. (line 8) * Dialect (class in csv): Module Contents<3>. (line 176) * dialect (csv.csvreader attribute): Reader Objects. (line 18) * dialect (csv.csvwriter attribute): Writer Objects. (line 31) * Dialog (class in msilib): GUI classes. (line 40) * dict (2to3 fixer): Fixers. (line 70) * dict (built-in class): Mapping Types — dict. (line 27) * Dict (class in typing): Classes functions and decorators. (line 349) * dict() (multiprocessing.managers.SyncManager method): Managers. (line 205) * dictConfig() (in module logging.config): Configuration functions. (line 13) * dictionary: Glossary. (line 341) * dictionary comprehension: Glossary. (line 347) * dictionary view: Glossary. (line 355) * dictionary; comprehensions: Dictionary displays. (line 6) * dictionary; display: Dictionary displays. (line 6) * DictReader (class in csv): Module Contents<3>. (line 102) * DictWriter (class in csv): Module Contents<3>. (line 143) * Differ (class in difflib): difflib — Helpers for computing deltas. (line 50) * difference() (frozenset method): Set Types — set frozenset. (line 109) * difference_update() (frozenset method): Set Types — set frozenset. (line 182) * difflib (module): difflib — Helpers for computing deltas. (line 6) * diff_bytes() (in module difflib): difflib — Helpers for computing deltas. (line 339) * diff_files (filecmp.dircmp attribute): The dircmp class. (line 90) * digest() (hashlib.hash method): Hash algorithms. (line 128) * digest() (hashlib.shake method): SHAKE variable length digests. (line 11) * digest() (hmac.HMAC method): hmac — Keyed-Hashing for Message Authentication. (line 56) * digest() (in module hmac): hmac — Keyed-Hashing for Message Authentication. (line 31) * digest_size (hmac.HMAC attribute): hmac — Keyed-Hashing for Message Authentication. (line 90) * digit() (in module unicodedata): unicodedata — Unicode Database. (line 37) * digits (in module string): String constants. (line 24) * dir() (built-in function): Built-in Functions. (line 380) * dir() (ftplib.FTP method): FTP Objects. (line 189) * dircmp (class in filecmp): The dircmp class. (line 6) * Directory (class in msilib): Directory Objects. (line 6) * directory (http.server.SimpleHTTPRequestHandler attribute): http server — HTTP servers. (line 357) * directory; changing: Files and Directories. (line 117) * directory; creating: Files and Directories. (line 454) * directory; deleting: Directory and files operations. (line 257) * directory; deleting <1>: Files and Directories. (line 644) * directory; traversal: Files and Directories. (line 1493) * directory; traversal <1>: Files and Directories. (line 1589) * directory; walking: Files and Directories. (line 1493) * directory; walking <1>: Files and Directories. (line 1589) * directory_created() (built-in function): The Postinstallation script. (line 23) * DirEntry (class in os): Files and Directories. (line 821) * DirList (class in tkinter.tix): File Selectors. (line 6) * dirname() (in module os.path): os path — Common pathname manipulations. (line 106) * DirSelectBox (class in tkinter.tix): File Selectors. (line 26) * DirSelectDialog (class in tkinter.tix): File Selectors. (line 20) * DirsOnSysPath (class in test.support): test support — Utilities for the Python test suite. (line 1069) * DirTree (class in tkinter.tix): File Selectors. (line 13) * dis (module): dis — Disassembler for Python bytecode. (line 6) * dis() (dis.Bytecode method): Bytecode analysis. (line 47) * dis() (in module dis): Analysis functions. (line 40) * dis() (in module pickletools): Programmatic Interface<2>. (line 6) * disable (pdb command): Debugger Commands. (line 100) * disable() (bdb.Breakpoint method): bdb — Debugger framework. (line 51) * disable() (in module faulthandler): Fault handler state. (line 22) * disable() (in module gc): gc — Garbage Collector interface. (line 26) * disable() (in module logging): Module-Level Functions. (line 167) * disable() (profile.Profile method): profile and cProfile Module Reference. (line 82) * DisableReflectionKey() (in module winreg): Functions<11>. (line 487) * disable_faulthandler() (in module test.support): test support — Utilities for the Python test suite. (line 470) * disable_gc() (in module test.support): test support — Utilities for the Python test suite. (line 482) * disable_interspersed_args() (optparse.OptionParser method): Querying and manipulating your option parser. (line 10) * disassemble() (in module dis): Analysis functions. (line 81) * discard (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 54) * discard() (frozenset method): Set Types — set frozenset. (line 204) * discard() (mailbox.Mailbox method): Mailbox objects. (line 76) * discard() (mailbox.MH method): MH. (line 76) * discard_buffers() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 84) * disco() (in module dis): Analysis functions. (line 81) * discover() (unittest.TestLoader method): Loading and running tests. (line 117) * disk_usage() (in module shutil): Directory and files operations. (line 340) * dispatcher (class in asyncore): asyncore — Asynchronous socket handler. (line 67) * dispatcher_with_send (class in asyncore): asyncore — Asynchronous socket handler. (line 250) * dispatch_call() (bdb.Bdb method): bdb — Debugger framework. (line 157) * dispatch_exception() (bdb.Bdb method): bdb — Debugger framework. (line 177) * dispatch_line() (bdb.Bdb method): bdb — Debugger framework. (line 147) * dispatch_return() (bdb.Bdb method): bdb — Debugger framework. (line 167) * dispatch_table (pickle.Pickler attribute): Module Interface. (line 176) * display (pdb command): Debugger Commands. (line 257) * displayhook() (in module sys): sys — System-specific parameters and functions. (line 244) * display_name (email.headerregistry.Address attribute): email headerregistry Custom Header Objects. (line 426) * display_name (email.headerregistry.Group attribute): email headerregistry Custom Header Objects. (line 471) * dist() (in module math): Trigonometric functions. (line 32) * distance() (in module turtle): Tell Turtle’s state. (line 68) * distb() (in module dis): Analysis functions. (line 70) * Distribution (class in distutils.core): distutils core — Core Distutils functionality. (line 294) * distutils (module): distutils — Building and installing Python modules. (line 6) * distutils.archive_util (module): distutils archive_util — Archiving utilities. (line 6) * distutils.bcppcompiler (module): distutils bcppcompiler — Borland Compiler. (line 6) * distutils.ccompiler (module): distutils ccompiler — CCompiler base class. (line 6) * distutils.cmd (module): distutils cmd — Abstract base class for Distutils commands. (line 6) * distutils.command (module): distutils command — Individual Distutils commands. (line 5) * distutils.command.bdist (module): distutils command bdist — Build a binary installer. (line 5) * distutils.command.bdist_dumb (module): distutils command bdist_dumb — Build a “dumb” installer. (line 5) * distutils.command.bdist_msi (module): distutils command bdist_msi — Build a Microsoft Installer binary package. (line 6) * distutils.command.bdist_packager (module): distutils command bdist_packager — Abstract base class for packagers. (line 5) * distutils.command.bdist_rpm (module): distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM. (line 5) * distutils.command.bdist_wininst (module): distutils command bdist_wininst — Build a Windows installer. (line 6) * distutils.command.build (module): distutils command build — Build all files of a package. (line 5) * distutils.command.build_clib (module): distutils command build_clib — Build any C libraries in a package. (line 5) * distutils.command.build_ext (module): distutils command build_ext — Build any extensions in a package. (line 5) * distutils.command.build_py (module): distutils command build_py — Build the py/ pyc files of a package. (line 6) * distutils.command.build_scripts (module): distutils command build_scripts — Build the scripts of a package. (line 5) * distutils.command.check (module): distutils command check — Check the meta-data of a package. (line 6) * distutils.command.clean (module): distutils command clean — Clean a package build area. (line 6) * distutils.command.config (module): distutils command config — Perform package configuration. (line 5) * distutils.command.install (module): distutils command install — Install a package. (line 5) * distutils.command.install_data (module): distutils command install_data — Install data files from a package. (line 5) * distutils.command.install_headers (module): distutils command install_headers — Install C/C++ header files from a package. (line 5) * distutils.command.install_lib (module): distutils command install_lib — Install library files from a package. (line 5) * distutils.command.install_scripts (module): distutils command install_scripts — Install script files from a package. (line 5) * distutils.command.register (module): distutils command register — Register a module with the Python Package Index. (line 6) * distutils.command.sdist (module): distutils command sdist — Build a source distribution. (line 5) * distutils.core (module): distutils core — Core Distutils functionality. (line 6) * distutils.cygwinccompiler (module): distutils cygwincompiler — Cygwin Compiler. (line 6) * distutils.debug (module): distutils debug — Distutils debug mode. (line 6) * distutils.dep_util (module): distutils dep_util — Dependency checking. (line 6) * distutils.dir_util (module): distutils dir_util — Directory tree operations. (line 6) * distutils.dist (module): distutils dist — The Distribution class. (line 6) * distutils.errors (module): distutils errors — Distutils exceptions. (line 6) * distutils.extension (module): distutils extension — The Extension class. (line 6) * distutils.fancy_getopt (module): distutils fancy_getopt — Wrapper around the standard getopt module. (line 6) * distutils.filelist (module): distutils filelist — The FileList class. (line 6) * distutils.file_util (module): distutils file_util — Single file operations. (line 6) * distutils.log (module): distutils log — Simple PEP 282-style logging. (line 5) * distutils.msvccompiler (module): distutils msvccompiler — Microsoft Compiler. (line 6) * distutils.spawn (module): distutils spawn — Spawn a sub-process. (line 6) * distutils.sysconfig (module): distutils sysconfig — System configuration information. (line 6) * distutils.text_file (module): distutils text_file — The TextFile class. (line 6) * distutils.unixccompiler (module): distutils unixccompiler — Unix C Compiler. (line 6) * distutils.util (module): distutils util — Miscellaneous other utility functions. (line 6) * distutils.version (module): distutils version — Version number classes. (line 5) * DISTUTILS_DEBUG: Debugging the setup script. (line 19) * divide() (decimal.Context method): Context objects. (line 271) * divide_int() (decimal.Context method): Context objects. (line 275) * division: Binary arithmetic operations. (line 28) * DivisionByZero (class in decimal): Signals. (line 33) * divmod() (built-in function): Built-in Functions. (line 438) * divmod() (decimal.Context method): Context objects. (line 279) * DllCanUnloadNow() (in module ctypes): Utility functions. (line 76) * DllGetClassObject() (in module ctypes): Utility functions. (line 82) * dllhandle (in module sys): sys — System-specific parameters and functions. (line 238) * dngettext() (in module gettext): GNU gettext API. (line 68) * dnpgettext() (in module gettext): GNU gettext API. (line 79) * doc (json.JSONDecodeError attribute): Exceptions<13>. (line 15) * DocCGIXMLRPCRequestHandler (class in xmlrpc.server): Documenting XMLRPC server. (line 22) * DocFileSuite() (in module doctest): Unittest API. (line 24) * doClassCleanups() (unittest.TestCase class method): Test cases. (line 792) * doCleanups() (unittest.TestCase method): Test cases. (line 760) * docmd() (smtplib.SMTP method): SMTP Objects. (line 17) * docstring: Class definitions. (line 6) * docstring <1>: Glossary. (line 365) * docstring (doctest.DocTest attribute): DocTest Objects. (line 49) * docstrings: Defining Functions. (line 21) * docstrings <1>: Documentation Strings. (line 6) * DocTest (class in doctest): DocTest Objects. (line 6) * doctest (module): doctest — Test interactive Python examples. (line 6) * DocTestFailure: Debugging. (line 186) * DocTestFinder (class in doctest): DocTestFinder objects. (line 6) * DocTestParser (class in doctest): DocTestParser objects. (line 6) * DocTestRunner (class in doctest): DocTestRunner objects. (line 6) * DocTestSuite() (in module doctest): Unittest API. (line 99) * doctype() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 66) * documentation string: The standard type hierarchy. (line 703) * documentation strings: Defining Functions. (line 21) * documentation strings <1>: Documentation Strings. (line 6) * documentation; generation: pydoc — Documentation generator and online help system. (line 8) * documentation; online: pydoc — Documentation generator and online help system. (line 8) * documentElement (xml.dom.Document attribute): Document Objects. (line 10) * DocXMLRPCRequestHandler (class in xmlrpc.server): Documenting XMLRPC server. (line 27) * DocXMLRPCServer (class in xmlrpc.server): Documenting XMLRPC server. (line 11) * doc_header (cmd.Cmd attribute): Cmd Objects. (line 147) * domain (email.headerregistry.Address attribute): email headerregistry Custom Header Objects. (line 437) * domain (tracemalloc.DomainFilter attribute): DomainFilter. (line 20) * domain (tracemalloc.Filter attribute): Filter. (line 30) * domain (tracemalloc.Trace attribute): Trace. (line 15) * DomainFilter (class in tracemalloc): DomainFilter. (line 6) * DomainLiberal (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 156) * DomainRFC2965Match (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 149) * DomainStrict (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 161) * DomainStrictNoDots (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 136) * DomainStrictNonDomain (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 142) * domain_initial_dot (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 86) * domain_return_ok() (http.cookiejar.CookiePolicy method): CookiePolicy Objects. (line 27) * domain_specified (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 82) * DOMEventStream (class in xml.dom.pulldom): DOMEventStream Objects. (line 6) * DOMException: Exceptions<16>. (line 18) * doModuleCleanups() (in module unittest): setUpModule and tearDownModule. (line 35) * DomstringSizeErr: Exceptions<16>. (line 23) * done() (asyncio.Future method): Future Object. (line 59) * done() (asyncio.Task method): Task Object. (line 113) * done() (concurrent.futures.Future method): Future Objects. (line 33) * done() (in module turtle): Using screen events. (line 106) * done() (xdrlib.Unpacker method): Unpacker Objects. (line 26) * DONT_ACCEPT_BLANKLINE (in module doctest): Option Flags. (line 30) * DONT_ACCEPT_TRUE_FOR_1 (in module doctest): Option Flags. (line 18) * dont_write_bytecode (in module sys): sys — System-specific parameters and functions. (line 280) * doRollover() (logging.handlers.RotatingFileHandler method): RotatingFileHandler. (line 38) * doRollover() (logging.handlers.TimedRotatingFileHandler method): TimedRotatingFileHandler. (line 101) * DOT (in module token): token — Constants used with Python parse trees. (line 118) * dot() (in module turtle): Turtle motion. (line 218) * DOTALL (in module re): Module Contents. (line 113) * doublequote (csv.Dialect attribute): Dialects and Formatting Parameters. (line 24) * DOUBLESLASH (in module token): token — Constants used with Python parse trees. (line 214) * DOUBLESLASHEQUAL (in module token): token — Constants used with Python parse trees. (line 218) * DOUBLESTAR (in module token): token — Constants used with Python parse trees. (line 166) * DOUBLESTAREQUAL (in module token): token — Constants used with Python parse trees. (line 210) * doupdate() (in module curses): Functions<3>. (line 89) * down (pdb command): Debugger Commands. (line 61) * down() (in module turtle): Drawing state. (line 6) * do_clear() (bdb.Bdb method): bdb — Debugger framework. (line 234) * do_command() (curses.textpad.Textbox method): Textbox objects. (line 30) * do_GET() (http.server.SimpleHTTPRequestHandler method): http server — HTTP servers. (line 372) * do_handshake() (ssl.SSLSocket method): SSL Sockets. (line 121) * do_HEAD() (http.server.SimpleHTTPRequestHandler method): http server — HTTP servers. (line 365) * do_POST() (http.server.CGIHTTPRequestHandler method): http server — HTTP servers. (line 484) * dpgettext() (in module gettext): GNU gettext API. (line 75) * drain() (asyncio.StreamWriter method): StreamWriter. (line 66) * dropwhile() (in module itertools): Itertool functions. (line 266) * drop_whitespace (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 190) * dst() (datetime.datetime method): datetime Objects. (line 485) * dst() (datetime.time method): time Objects. (line 233) * dst() (datetime.timezone method): timezone Objects. (line 57) * dst() (datetime.tzinfo method): tzinfo Objects. (line 65) * DTDHandler (class in xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 24) * duck-typing: Glossary. (line 374) * DumbWriter (class in formatter): Writer Implementations. (line 22) * dummy_threading (module): dummy_threading — Drop-in replacement for the threading module. (line 6) * dump() (in module ast): ast Helpers. (line 199) * dump() (in module json): Basic Usage. (line 6) * dump() (in module marshal): marshal — Internal Python object serialization. (line 47) * dump() (in module pickle): Module Interface. (line 35) * dump() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 85) * dump() (in module xml.etree.ElementTree): Functions<6>. (line 86) * dump() (pickle.Pickler method): Module Interface. (line 155) * dump() (tracemalloc.Snapshot method): Snapshot. (line 29) * dumps() (in module json): Basic Usage. (line 78) * dumps() (in module marshal): marshal — Internal Python object serialization. (line 72) * dumps() (in module pickle): Module Interface. (line 47) * dumps() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 115) * dumps() (in module xmlrpc.client): Convenience Functions. (line 6) * dump_stats() (profile.Profile method): profile and cProfile Module Reference. (line 96) * dump_stats() (pstats.Stats method): The Stats Class. (line 59) * dump_traceback() (in module faulthandler): Dumping the traceback. (line 6) * dump_traceback_later() (in module faulthandler): Dumping the tracebacks after a timeout. (line 6) * dup() (in module os): File Descriptor Operations. (line 73) * dup() (socket.socket method): Socket Objects. (line 102) * dup2() (in module os): File Descriptor Operations. (line 85) * DuplicateOptionError: Exceptions<5>. (line 24) * DuplicateSectionError: Exceptions<5>. (line 14) * DUP_TOP (opcode): Python Bytecode Instructions. (line 79) * DUP_TOP_TWO (opcode): Python Bytecode Instructions. (line 85) * dwFlags (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 19) * DynamicClassAttribute() (in module types): Additional Utility Classes and Functions. (line 38) * D_FMT (in module locale): locale — Internationalization services. (line 195) * D_T_FMT (in module locale): locale — Internationalization services. (line 189) * e (in module cmath): Constants<3>. (line 10) * e (in module math): Constants<2>. (line 10) * E2BIG (in module errno): errno — Standard errno system symbols. (line 55) * e; in numeric literal: Integer literals. (line 40) * EACCES (in module errno): errno — Standard errno system symbols. (line 79) * EADDRINUSE (in module errno): errno — Standard errno system symbols. (line 419) * EADDRNOTAVAIL (in module errno): errno — Standard errno system symbols. (line 423) * EADV (in module errno): errno — Standard errno system symbols. (line 299) * EAFNOSUPPORT (in module errno): errno — Standard errno system symbols. (line 415) * EAFP: Glossary. (line 387) * EAGAIN (in module errno): errno — Standard errno system symbols. (line 71) * EALREADY (in module errno): errno — Standard errno system symbols. (line 483) * east_asian_width() (in module unicodedata): unicodedata — Unicode Database. (line 64) * EBADE (in module errno): errno — Standard errno system symbols. (line 235) * EBADF (in module errno): errno — Standard errno system symbols. (line 63) * EBADFD (in module errno): errno — Standard errno system symbols. (line 335) * EBADMSG (in module errno): errno — Standard errno system symbols. (line 323) * EBADR (in module errno): errno — Standard errno system symbols. (line 239) * EBADRQC (in module errno): errno — Standard errno system symbols. (line 251) * EBADSLT (in module errno): errno — Standard errno system symbols. (line 255) * EBFONT (in module errno): errno — Standard errno system symbols. (line 263) * EBUSY (in module errno): errno — Standard errno system symbols. (line 91) * ECHILD (in module errno): errno — Standard errno system symbols. (line 67) * echo() (in module curses): Functions<3>. (line 105) * echochar() (curses.window method): Window Objects. (line 196) * ECHRNG (in module errno): errno — Standard errno system symbols. (line 203) * ECOMM (in module errno): errno — Standard errno system symbols. (line 307) * ECONNABORTED (in module errno): errno — Standard errno system symbols. (line 439) * ECONNREFUSED (in module errno): errno — Standard errno system symbols. (line 471) * ECONNRESET (in module errno): errno — Standard errno system symbols. (line 443) * EDEADLK (in module errno): errno — Standard errno system symbols. (line 167) * EDEADLOCK (in module errno): errno — Standard errno system symbols. (line 259) * EDESTADDRREQ (in module errno): errno — Standard errno system symbols. (line 383) * edit() (curses.textpad.Textbox method): Textbox objects. (line 19) * EDOM (in module errno): errno — Standard errno system symbols. (line 159) * EDOTDOT (in module errno): errno — Standard errno system symbols. (line 319) * EDQUOT (in module errno): errno — Standard errno system symbols. (line 515) * EEXIST (in module errno): errno — Standard errno system symbols. (line 95) * EFAULT (in module errno): errno — Standard errno system symbols. (line 83) * EFBIG (in module errno): errno — Standard errno system symbols. (line 135) * effective() (in module bdb): bdb — Debugger framework. (line 397) * ehlo() (smtplib.SMTP method): SMTP Objects. (line 58) * ehlo_or_helo_if_needed() (smtplib.SMTP method): SMTP Objects. (line 75) * EHOSTDOWN (in module errno): errno — Standard errno system symbols. (line 475) * EHOSTUNREACH (in module errno): errno — Standard errno system symbols. (line 479) * EIDRM (in module errno): errno — Standard errno system symbols. (line 199) * EILSEQ (in module errno): errno — Standard errno system symbols. (line 363) * EINPROGRESS (in module errno): errno — Standard errno system symbols. (line 487) * EINTR (in module errno): errno — Standard errno system symbols. (line 38) * EINVAL (in module errno): errno — Standard errno system symbols. (line 115) * EIO (in module errno): errno — Standard errno system symbols. (line 47) * EISCONN (in module errno): errno — Standard errno system symbols. (line 451) * EISDIR (in module errno): errno — Standard errno system symbols. (line 111) * EISNAM (in module errno): errno — Standard errno system symbols. (line 507) * EL2HLT (in module errno): errno — Standard errno system symbols. (line 231) * EL2NSYNC (in module errno): errno — Standard errno system symbols. (line 207) * EL3HLT (in module errno): errno — Standard errno system symbols. (line 211) * EL3RST (in module errno): errno — Standard errno system symbols. (line 215) * Element (class in xml.etree.ElementTree): Element Objects. (line 6) * ElementDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 202) * elements() (collections.Counter method): Counter objects. (line 66) * ElementTree (class in xml.etree.ElementTree): ElementTree Objects. (line 6) * element_create() (tkinter.ttk.Style method): Ttk Styling. (line 131) * element_names() (tkinter.ttk.Style method): Ttk Styling. (line 183) * element_options() (tkinter.ttk.Style method): Ttk Styling. (line 187) * ELIBACC (in module errno): errno — Standard errno system symbols. (line 343) * ELIBBAD (in module errno): errno — Standard errno system symbols. (line 347) * ELIBEXEC (in module errno): errno — Standard errno system symbols. (line 359) * ELIBMAX (in module errno): errno — Standard errno system symbols. (line 355) * ELIBSCN (in module errno): errno — Standard errno system symbols. (line 351) * Ellinghouse, Lance: uu — Encode and decode uuencode files. (line 20) * Ellipsis (built-in variable): Built-in Constants. (line 52) * ELLIPSIS (in module doctest): Option Flags. (line 49) * ELLIPSIS (in module token): token — Constants used with Python parse trees. (line 234) * ELNRNG (in module errno): errno — Standard errno system symbols. (line 219) * ELOOP (in module errno): errno — Standard errno system symbols. (line 187) * else; conditional expression: Conditional expressions. (line 6) * email (module): email — An email and MIME handling package. (line 6) * email.charset (module): email charset Representing character sets. (line 6) * email.contentmanager (module): email contentmanager Managing MIME Content. (line 6) * email.encoders (module): email encoders Encoders. (line 6) * email.errors (module): email errors Exception and Defect classes. (line 6) * email.generator (module): email generator Generating MIME documents. (line 6) * email.header (module): email header Internationalized headers. (line 6) * email.headerregistry (module): email headerregistry Custom Header Objects. (line 6) * email.iterators (module): email iterators Iterators. (line 6) * email.message (module): email message Representing an email message. (line 6) * email.mime (module): email mime Creating email and MIME objects from scratch. (line 6) * email.parser (module): email parser Parsing email messages. (line 6) * email.policy (module): email policy Policy Objects. (line 6) * email.utils (module): email utils Miscellaneous utilities. (line 6) * EmailMessage (class in email.message): email message Representing an email message. (line 52) * EmailPolicy (class in email.policy): email policy Policy Objects. (line 343) * EMFILE (in module errno): errno — Standard errno system symbols. (line 123) * emit() (logging.FileHandler method): FileHandler. (line 27) * emit() (logging.Handler method): Handler Objects. (line 107) * emit() (logging.handlers.BufferingHandler method): MemoryHandler. (line 24) * emit() (logging.handlers.DatagramHandler method): DatagramHandler. (line 20) * emit() (logging.handlers.HTTPHandler method): HTTPHandler. (line 36) * emit() (logging.handlers.NTEventLogHandler method): NTEventLogHandler. (line 38) * emit() (logging.handlers.QueueHandler method): QueueHandler. (line 31) * emit() (logging.handlers.RotatingFileHandler method): RotatingFileHandler. (line 42) * emit() (logging.handlers.SMTPHandler method): SMTPHandler. (line 35) * emit() (logging.handlers.SocketHandler method): SocketHandler. (line 24) * emit() (logging.handlers.SysLogHandler method): SysLogHandler. (line 43) * emit() (logging.handlers.TimedRotatingFileHandler method): TimedRotatingFileHandler. (line 105) * emit() (logging.handlers.WatchedFileHandler method): WatchedFileHandler. (line 46) * emit() (logging.NullHandler method): NullHandler. (line 16) * emit() (logging.StreamHandler method): StreamHandler. (line 17) * EMLINK (in module errno): errno — Standard errno system symbols. (line 151) * Empty: queue — A synchronized queue class. (line 82) * empty (inspect.Parameter attribute): Introspecting callables with the Signature object. (line 152) * empty (inspect.Signature attribute): Introspecting callables with the Signature object. (line 74) * empty() (asyncio.Queue method): Queue. (line 28) * empty() (multiprocessing.Queue method): Pipes and Queues. (line 108) * empty() (multiprocessing.SimpleQueue method): Pipes and Queues. (line 209) * empty() (queue.Queue method): Queue Objects. (line 15) * empty() (queue.SimpleQueue method): SimpleQueue Objects. (line 14) * empty() (sched.scheduler method): Scheduler Objects. (line 47) * empty; list: List displays. (line 6) * empty; tuple: The standard type hierarchy. (line 172) * empty; tuple <1>: Parenthesized forms. (line 16) * emptyline() (cmd.Cmd method): Cmd Objects. (line 68) * EMPTY_NAMESPACE (in module xml.dom): Module Contents<4>. (line 35) * EMSGSIZE (in module errno): errno — Standard errno system symbols. (line 387) * EMULTIHOP (in module errno): errno — Standard errno system symbols. (line 315) * enable (pdb command): Debugger Commands. (line 107) * enable() (bdb.Breakpoint method): bdb — Debugger framework. (line 47) * enable() (imaplib.IMAP4 method): IMAP4 Objects. (line 84) * enable() (in module cgitb): cgitb — Traceback manager for CGI scripts. (line 30) * enable() (in module faulthandler): Fault handler state. (line 6) * enable() (in module gc): gc — Garbage Collector interface. (line 22) * enable() (profile.Profile method): profile and cProfile Module Reference. (line 78) * EnableReflectionKey() (in module winreg): Functions<11>. (line 505) * enable_callback_tracebacks() (in module sqlite3): Module functions and constants. (line 189) * enable_interspersed_args() (optparse.OptionParser method): Querying and manipulating your option parser. (line 31) * enable_load_extension() (sqlite3.Connection method): Connection Objects. (line 250) * enable_traversal() (tkinter.ttk.Notebook method): ttk Notebook. (line 75) * ENABLE_USER_SITE (in module site): Module contents<3>. (line 10) * ENAMETOOLONG (in module errno): errno — Standard errno system symbols. (line 171) * ENAVAIL (in module errno): errno — Standard errno system symbols. (line 503) * enclose() (curses.window method): Window Objects. (line 201) * encode (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 69) * encode() (codecs.Codec method): Stateless Encoding and Decoding. (line 9) * encode() (codecs.IncrementalEncoder method): IncrementalEncoder Objects. (line 28) * encode() (email.header.Header method): email header Internationalized headers. (line 125) * encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 226) * encode() (in module codecs): codecs — Codec registry and base classes. (line 23) * encode() (in module quopri): quopri — Encode and decode MIME quoted-printable data. (line 29) * encode() (in module uu): uu — Encode and decode uuencode files. (line 25) * encode() (json.JSONEncoder method): Encoders and Decoders. (line 216) * encode() (str method): String Methods<2>. (line 61) * encode() (xmlrpc.client.Binary method): Binary Objects. (line 25) * encode() (xmlrpc.client.DateTime method): DateTime Objects. (line 17) * encodebytes() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 236) * EncodedFile() (in module codecs): codecs — Codec registry and base classes. (line 194) * encodePriority() (logging.handlers.SysLogHandler method): SysLogHandler. (line 77) * encodestring() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 246) * encodestring() (in module quopri): quopri — Encode and decode MIME quoted-printable data. (line 46) * encode_7or8bit() (in module email.encoders): email encoders Encoders. (line 57) * encode_base64() (in module email.encoders): email encoders Encoders. (line 49) * encode_noop() (in module email.encoders): email encoders Encoders. (line 63) * encode_quopri() (in module email.encoders): email encoders Encoders. (line 42) * encode_rfc2231() (in module email.utils): email utils Miscellaneous utilities. (line 178) * encoding (curses.window attribute): Window Objects. (line 208) * ENCODING (in module tarfile): tarfile — Read and write tar archive files. (line 213) * ENCODING (in module token): token — Constants used with Python parse trees. (line 272) * encoding (io.TextIOBase attribute): Text I/O<2>. (line 15) * encoding (UnicodeError attribute): Concrete exceptions. (line 342) * encoding declarations (source file): Encoding declarations. (line 6) * encodings.idna (module): encodings idna — Internationalized Domain Names in Applications. (line 6) * encodings.mbcs (module): encodings mbcs — Windows ANSI codepage. (line 6) * encodings.utf_8_sig (module): encodings utf_8_sig — UTF-8 codec with BOM signature. (line 6) * encodings_map (in module mimetypes): mimetypes — Map filenames to MIME types. (line 136) * encodings_map (mimetypes.MimeTypes attribute): MimeTypes Objects. (line 33) * end (UnicodeError attribute): Concrete exceptions. (line 358) * end() (re.Match method): Match Objects. (line 132) * end() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 38) * EndCdataSectionHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 306) * EndDoctypeDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 197) * endDocument() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 40) * endElement() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 95) * EndElementHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 232) * endElementNS() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 121) * endheaders() (http.client.HTTPConnection method): HTTPConnection Objects. (line 143) * ENDMARKER (in module token): token — Constants used with Python parse trees. (line 40) * EndNamespaceDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 285) * endpos (re.Match attribute): Match Objects. (line 171) * endPrefixMapping() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 73) * endswith() (bytearray method): Bytes and Bytearray Operations. (line 67) * endswith() (bytes method): Bytes and Bytearray Operations. (line 67) * endswith() (str method): String Methods<2>. (line 75) * endwin() (in module curses): Functions<3>. (line 110) * END_ASYNC_FOR (opcode): Python Bytecode Instructions. (line 284) * end_col_offset (ast.AST attribute): Node classes. (line 39) * end_fill() (in module turtle): Filling. (line 20) * END_FINALLY (opcode): Python Bytecode Instructions. (line 415) * end_headers() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 265) * end_lineno (ast.AST attribute): Node classes. (line 39) * end_ns() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 85) * end_paragraph() (formatter.formatter method): The Formatter Interface. (line 26) * end_poly() (in module turtle): Special Turtle methods. (line 11) * ENETDOWN (in module errno): errno — Standard errno system symbols. (line 427) * ENETRESET (in module errno): errno — Standard errno system symbols. (line 435) * ENETUNREACH (in module errno): errno — Standard errno system symbols. (line 431) * ENFILE (in module errno): errno — Standard errno system symbols. (line 119) * ENOANO (in module errno): errno — Standard errno system symbols. (line 247) * ENOBUFS (in module errno): errno — Standard errno system symbols. (line 447) * ENOCSI (in module errno): errno — Standard errno system symbols. (line 227) * ENODATA (in module errno): errno — Standard errno system symbols. (line 271) * ENODEV (in module errno): errno — Standard errno system symbols. (line 103) * ENOENT (in module errno): errno — Standard errno system symbols. (line 30) * ENOEXEC (in module errno): errno — Standard errno system symbols. (line 59) * ENOLCK (in module errno): errno — Standard errno system symbols. (line 175) * ENOLINK (in module errno): errno — Standard errno system symbols. (line 295) * ENOMEM (in module errno): errno — Standard errno system symbols. (line 75) * ENOMSG (in module errno): errno — Standard errno system symbols. (line 195) * ENONET (in module errno): errno — Standard errno system symbols. (line 283) * ENOPKG (in module errno): errno — Standard errno system symbols. (line 287) * ENOPROTOOPT (in module errno): errno — Standard errno system symbols. (line 395) * ENOSPC (in module errno): errno — Standard errno system symbols. (line 139) * ENOSR (in module errno): errno — Standard errno system symbols. (line 279) * ENOSTR (in module errno): errno — Standard errno system symbols. (line 267) * ENOSYS (in module errno): errno — Standard errno system symbols. (line 179) * ENOTBLK (in module errno): errno — Standard errno system symbols. (line 87) * ENOTCONN (in module errno): errno — Standard errno system symbols. (line 455) * ENOTDIR (in module errno): errno — Standard errno system symbols. (line 107) * ENOTEMPTY (in module errno): errno — Standard errno system symbols. (line 183) * ENOTNAM (in module errno): errno — Standard errno system symbols. (line 499) * ENOTSOCK (in module errno): errno — Standard errno system symbols. (line 379) * ENOTTY (in module errno): errno — Standard errno system symbols. (line 127) * ENOTUNIQ (in module errno): errno — Standard errno system symbols. (line 331) * enqueue() (logging.handlers.QueueHandler method): QueueHandler. (line 53) * enqueue_sentinel() (logging.handlers.QueueListener method): QueueListener. (line 87) * ensurepip (module): ensurepip — Bootstrapping the pip installer. (line 6) * ensure_directories() (venv.EnvBuilder method): API<2>. (line 77) * ensure_future() (in module asyncio): Future Functions. (line 19) * enter() (sched.scheduler method): Scheduler Objects. (line 30) * enterabs() (sched.scheduler method): Scheduler Objects. (line 9) * enter_async_context() (contextlib.AsyncExitStack method): Utilities. (line 463) * enter_context() (contextlib.ExitStack method): Utilities. (line 382) * entities (xml.dom.DocumentType attribute): DocumentType Objects. (line 38) * EntityDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 258) * entitydefs (in module html.entities): html entities — Definitions of HTML general entities. (line 25) * EntityResolver (class in xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 31) * Enum (class in enum): Module Contents<2>. (line 11) * enum (module): enum — Support for enumerations. (line 6) * enumerate() (built-in function): Built-in Functions. (line 450) * enumerate() (in module threading): threading — Thread-based parallelism. (line 108) * EnumKey() (in module winreg): Functions<11>. (line 177) * EnumValue() (in module winreg): Functions<11>. (line 196) * enum_certificates() (in module ssl): Certificate handling. (line 129) * enum_crls() (in module ssl): Certificate handling. (line 152) * EnvBuilder (class in venv): API<2>. (line 11) * environ (in module os): Process Parameters. (line 16) * environ (in module posix): Notable Module Contents. (line 9) * environb (in module os): Process Parameters. (line 55) * environment: Resolution of names. (line 12) * environment variable; APPDATA: PEP 370 Per-user site-packages Directory. (line 26) * environment variable; AUDIODEV: ossaudiodev — Access to OSS-compatible audio devices. (line 54) * environment variable; BROWSER: webbrowser — Convenient Web-browser controller. (line 20) * environment variable; BROWSER <1>: webbrowser — Convenient Web-browser controller. (line 95) * environment variable; CC: New Improved and Deprecated Modules<4>. (line 58) * environment variable; CFLAGS: New Improved and Deprecated Modules<4>. (line 58) * environment variable; CFLAGS <1>: Tweaking compiler/linker flags. (line 66) * environment variable; CFLAGS <2>: Tweaking compiler/linker flags. (line 67) * environment variable; COLS: curses<2>. (line 7) * environment variable; COLS <1>: Functions<3>. (line 526) * environment variable; COLUMNS: Functions<3>. (line 550) * environment variable; COLUMNS <1>: Functions<3>. (line 553) * environment variable; COMSPEC: Process Management. (line 664) * environment variable; COMSPEC <1>: Popen Constructor. (line 90) * environment variable; CPP: New Improved and Deprecated Modules<4>. (line 59) * environment variable; CPPFLAGS: New Improved and Deprecated Modules<4>. (line 59) * environment variable; DISTUTILS_DEBUG: Debugging the setup script. (line 19) * environment variable; exec_prefix: Python-related paths and files. (line 7) * environment variable; exec_prefix <1>: Include Files. (line 37) * environment variable; exec_prefix <2>: Include Files. (line 48) * environment variable; HOME: os path. (line 15) * environment variable; HOME <1>: Changes in the Python API. (line 116) * environment variable; HOME <2>: os path — Common pathname manipulations. (line 140) * environment variable; HOME <3>: os path — Common pathname manipulations. (line 156) * environment variable; HOME <4>: distutils util — Miscellaneous other utility functions. (line 77) * environment variable; HOME <5>: Location and names of config files. (line 50) * environment variable; HOME <6>: Location and names of config files. (line 67) * environment variable; HOMEDRIVE: os path — Common pathname manipulations. (line 147) * environment variable; HOMEDRIVE <1>: Location and names of config files. (line 68) * environment variable; HOMEPATH: os path — Common pathname manipulations. (line 147) * environment variable; HOMEPATH <1>: Location and names of config files. (line 68) * environment variable; http_proxy: urllib request — Extensible library for opening URLs. (line 85) * environment variable; http_proxy <1>: Examples<21>. (line 97) * environment variable; http_proxy <2>: Basic Authentication. (line 62) * environment variable; IDLESTARTUP: Startup and code execution. (line 7) * environment variable; KDEDIR: webbrowser — Convenient Web-browser controller. (line 184) * environment variable; LANG: GNU gettext API. (line 21) * environment variable; LANG <1>: Class-based API. (line 26) * environment variable; LANG <2>: locale — Internationalization services. (line 49) * environment variable; LANG <3>: locale — Internationalization services. (line 310) * environment variable; LANG <4>: locale — Internationalization services. (line 314) * environment variable; LANGUAGE: GNU gettext API. (line 20) * environment variable; LANGUAGE <1>: Class-based API. (line 25) * environment variable; LC_ALL: GNU gettext API. (line 20) * environment variable; LC_ALL <1>: Class-based API. (line 25) * environment variable; LC_MESSAGES: GNU gettext API. (line 20) * environment variable; LC_MESSAGES <1>: Class-based API. (line 26) * environment variable; LDCXXSHARED: Build and C API Changes<8>. (line 153) * environment variable; LDFLAGS: New Improved and Deprecated Modules<4>. (line 59) * environment variable; LINES: curses<2>. (line 6) * environment variable; LINES <1>: Functions<3>. (line 125) * environment variable; LINES <2>: Functions<3>. (line 526) * environment variable; LINES <3>: Functions<3>. (line 550) * environment variable; LINES <4>: Functions<3>. (line 552) * environment variable; LNAME: getpass — Portable password input. (line 38) * environment variable; LOGNAME: Process Parameters. (line 221) * environment variable; LOGNAME <1>: getpass — Portable password input. (line 38) * environment variable; MIXERDEV: ossaudiodev — Access to OSS-compatible audio devices. (line 74) * environment variable; no_proxy: urllib request — Extensible library for opening URLs. (line 303) * environment variable; PAGER: pydoc — Documentation generator and online help system. (line 47) * environment variable; PATH: Changes in the Python API. (line 143) * environment variable; PATH <1>: Changes in ‘python’ Command Behavior<2>. (line 6) * environment variable; PATH <2>: Changes in ‘python’ Command Behavior<2>. (line 11) * environment variable; PATH <3>: Changes in ‘python’ Command Behavior<2>. (line 12) * environment variable; PATH <4>: The Module Search Path. (line 16) * environment variable; PATH <5>: Executable Python Scripts. (line 11) * environment variable; PATH <6>: Environment variables. (line 27) * environment variable; PATH <7>: Miscellaneous. (line 16) * environment variable; PATH <8>: Installation steps. (line 32) * environment variable; PATH <9>: Installation steps. (line 56) * environment variable; PATH <10>: Installing Without UI. (line 57) * environment variable; PATH <11>: Excursus Setting environment variables. (line 23) * environment variable; PATH <12>: Excursus Setting environment variables. (line 35) * environment variable; PATH <13>: Finding the Python executable. (line 14) * environment variable; PATH <14>: Finding the Python executable. (line 21) * environment variable; PATH <15>: Finding the Python executable. (line 22) * environment variable; PATH <16>: Python Launcher for Windows. (line 13) * environment variable; PATH <17>: From the command-line. (line 9) * environment variable; PATH <18>: From the command-line. (line 38) * environment variable; PATH <19>: Shebang Lines. (line 48) * environment variable; PATH <20>: Shebang Lines. (line 50) * environment variable; PATH <21>: Process Management. (line 45) * environment variable; PATH <22>: Process Management. (line 86) * environment variable; PATH <23>: Process Management. (line 89) * environment variable; PATH <24>: Process Management. (line 92) * environment variable; PATH <25>: Process Management. (line 453) * environment variable; PATH <26>: Process Management. (line 539) * environment variable; PATH <27>: Process Management. (line 543) * environment variable; PATH <28>: Process Management. (line 545) * environment variable; PATH <29>: Miscellaneous System Information. (line 118) * environment variable; PATH <30>: webbrowser — Convenient Web-browser controller. (line 214) * environment variable; PATH <31>: Installing your CGI script on a Unix system. (line 29) * environment variable; PATH <32>: Common problems and solutions. (line 23) * environment variable; PATH <33>: site — Site-specific configuration hook. (line 59) * environment variable; PATH <34>: Embedding Python<2>. (line 31) * environment variable; PATH <35>: Embedding Python<2>. (line 37) * environment variable; PATH <36>: How do I make a Python script executable on Unix?. (line 24) * environment variable; PATH <37>: How do I make a Python script executable on Unix?. (line 28) * environment variable; PATHEXT: Other Improvements<2>. (line 30) * environment variable; PATHEXT <1>: Installing Without UI. (line 58) * environment variable; PLAT: distutils util — Miscellaneous other utility functions. (line 79) * environment variable; POSIXLY_CORRECT: getopt — C-style parser for command line options. (line 71) * environment variable; prefix: Python-related paths and files. (line 7) * environment variable; prefix <1>: Include Files. (line 37) * environment variable; prefix <2>: Include Files. (line 40) * environment variable; prefix <3>: Include Files. (line 47) * environment variable; PYTHON*: Other Improvements<2>. (line 9) * environment variable; PYTHON* <1>: Interface options. (line 80) * environment variable; PYTHON* <2>: Interface options. (line 140) * environment variable; PYTHON* <3>: Miscellaneous options. (line 42) * environment variable; PYTHON* <4>: Miscellaneous options. (line 60) * environment variable; PYTHON* <5>: Global configuration variables. (line 56) * environment variable; PYTHONASYNCIODEBUG: Environment variables. (line 238) * environment variable; PYTHONASYNCIODEBUG <1>: Enabling debug mode. (line 10) * environment variable; PYTHONASYNCIODEBUG <2>: Debug Mode. (line 11) * environment variable; PYTHONBREAKPOINT: PEP 553 Built-in breakpoint. (line 13) * environment variable; PYTHONBREAKPOINT <1>: Environment variables. (line 66) * environment variable; PYTHONBREAKPOINT <2>: sys — System-specific parameters and functions. (line 202) * environment variable; PYTHONBREAKPOINT <3>: sys — System-specific parameters and functions. (line 216) * environment variable; PYTHONBREAKPOINT <4>: sys — System-specific parameters and functions. (line 220) * environment variable; PYTHONCASEOK: PEP 235 Importing Modules on Case-Insensitive Platforms. (line 17) * environment variable; PYTHONCASEOK <1>: Environment variables. (line 104) * environment variable; PYTHONCOERCECLOCALE: PEP 538 Legacy C Locale Coercion. (line 13) * environment variable; PYTHONCOERCECLOCALE <1>: Environment variables. (line 322) * environment variable; PYTHONCOERCECLOCALE <2>: Environment variables. (line 438) * environment variable; PYTHONCOERCECLOCALE <3>: Python Configuration. (line 15) * environment variable; PYTHONDEBUG: Miscellaneous options. (line 38) * environment variable; PYTHONDEBUG <1>: Environment variables. (line 79) * environment variable; PYTHONDEBUG <2>: Global configuration variables. (line 28) * environment variable; PYTHONDEVMODE: Development Runtime Mode -X dev. (line 6) * environment variable; PYTHONDEVMODE <1>: Environment variables. (line 378) * environment variable; PYTHONDEVMODE <2>: test support script_helper — Utilities for the Python execution tests. (line 106) * environment variable; PYTHONDOCS: pydoc — Documentation generator and online help system. (line 85) * environment variable; PYTHONDONTWRITEBYTECODE: Interpreter Changes<2>. (line 16) * environment variable; PYTHONDONTWRITEBYTECODE <1>: New and Improved Modules<2>. (line 625) * environment variable; PYTHONDONTWRITEBYTECODE <2>: Miscellaneous options. (line 19) * environment variable; PYTHONDONTWRITEBYTECODE <3>: Environment variables. (line 109) * environment variable; PYTHONDONTWRITEBYTECODE <4>: sys — System-specific parameters and functions. (line 285) * environment variable; PYTHONDONTWRITEBYTECODE <5>: Global configuration variables. (line 36) * environment variable; PYTHONDONTWRITEBYTECODE <6>: How do I create a pyc file?. (line 21) * environment variable; PYTHONDUMPREFS: Debug build uses the same ABI as release build. (line 14) * environment variable; PYTHONDUMPREFS <1>: Debug-mode variables. (line 14) * environment variable; PYTHONDUMPREFS <2>: PyObject Slots. (line 24) * environment variable; PYTHONEXECUTABLE: Environment variables. (line 182) * environment variable; PYTHONFAULTHANDLER: faulthandler<3>. (line 11) * environment variable; PYTHONFAULTHANDLER <1>: Environment variables. (line 209) * environment variable; PYTHONFAULTHANDLER <2>: faulthandler — Dump the Python traceback. (line 14) * environment variable; PYTHONHASHSEED: Builtin functions and types. (line 17) * environment variable; PYTHONHASHSEED <1>: Porting Python code. (line 6) * environment variable; PYTHONHASHSEED <2>: Miscellaneous options. (line 94) * environment variable; PYTHONHASHSEED <3>: Miscellaneous options. (line 110) * environment variable; PYTHONHASHSEED <4>: Environment variables. (line 124) * environment variable; PYTHONHASHSEED <5>: Environment variables. (line 129) * environment variable; PYTHONHASHSEED <6>: Basic customization. (line 298) * environment variable; PYTHONHASHSEED <7>: Global configuration variables. (line 48) * environment variable; PYTHONHASHSEED <8>: Global configuration variables. (line 51) * environment variable; PYTHONHOME: Summary – Release highlights<2>. (line 107) * environment variable; PYTHONHOME <1>: Miscellaneous options. (line 43) * environment variable; PYTHONHOME <2>: Environment variables. (line 11) * environment variable; PYTHONHOME <3>: Environment variables. (line 19) * environment variable; PYTHONHOME <4>: Environment variables. (line 21) * environment variable; PYTHONHOME <5>: Environment variables. (line 38) * environment variable; PYTHONHOME <6>: Finding modules. (line 50) * environment variable; PYTHONHOME <7>: Finding modules. (line 68) * environment variable; PYTHONHOME <8>: Finding modules. (line 102) * environment variable; PYTHONHOME <9>: test support script_helper — Utilities for the Python execution tests. (line 25) * environment variable; PYTHONHOME <10>: Embedding Python<2>. (line 38) * environment variable; PYTHONHOME <11>: Embedding Python<2>. (line 44) * environment variable; PYTHONHOME <12>: Global configuration variables. (line 57) * environment variable; PYTHONHOME <13>: Process-wide parameters. (line 270) * environment variable; PYTHONHOME <14>: Process-wide parameters. (line 284) * environment variable; PYTHONHOME <15>: PyConfig. (line 197) * environment variable; PYTHONHOME <16>: Modifying Python’s Search Path. (line 60) * environment variable; PYTHONHOME <17>: Modifying Python’s Search Path. (line 62) * environment variable; PYTHONINSPECT: Other Changes and Fixes<2>. (line 13) * environment variable; PYTHONINSPECT <1>: Miscellaneous options. (line 53) * environment variable; PYTHONINSPECT <2>: Environment variables. (line 85) * environment variable; PYTHONINSPECT <3>: Global configuration variables. (line 68) * environment variable; PYTHONIOENCODING: Other Improvements<2>. (line 75) * environment variable; PYTHONIOENCODING <1>: Interpreter Changes<2>. (line 23) * environment variable; PYTHONIOENCODING <2>: Environment variables. (line 142) * environment variable; PYTHONIOENCODING <3>: Environment variables. (line 359) * environment variable; PYTHONIOENCODING <4>: Environment variables. (line 426) * environment variable; PYTHONIOENCODING <5>: sys — System-specific parameters and functions. (line 1503) * environment variable; PYTHONIOENCODING <6>: Process-wide parameters. (line 14) * environment variable; PYTHONIOENCODING <7>: Process-wide parameters. (line 18) * environment variable; PYTHONLEGACYWINDOWSFSENCODING: PEP 529 Change Windows filesystem encoding to UTF-8. (line 18) * environment variable; PYTHONLEGACYWINDOWSFSENCODING <1>: Environment variables. (line 295) * environment variable; PYTHONLEGACYWINDOWSFSENCODING <2>: sys — System-specific parameters and functions. (line 1455) * environment variable; PYTHONLEGACYWINDOWSFSENCODING <3>: Global configuration variables. (line 90) * environment variable; PYTHONLEGACYWINDOWSSTDIO: PEP 528 Change Windows console encoding to UTF-8. (line 12) * environment variable; PYTHONLEGACYWINDOWSSTDIO <1>: Environment variables. (line 156) * environment variable; PYTHONLEGACYWINDOWSSTDIO <2>: Environment variables. (line 309) * environment variable; PYTHONLEGACYWINDOWSSTDIO <3>: sys — System-specific parameters and functions. (line 1507) * environment variable; PYTHONLEGACYWINDOWSSTDIO <4>: Global configuration variables. (line 102) * environment variable; PYTHONMALLOC: PYTHONMALLOC environment variable. (line 6) * environment variable; PYTHONMALLOC <1>: Changes in the C API<3>. (line 9) * environment variable; PYTHONMALLOC <2>: Environment variables. (line 245) * environment variable; PYTHONMALLOC <3>: Environment variables. (line 286) * environment variable; PYTHONMALLOC <4>: Overview<3>. (line 75) * environment variable; PYTHONMALLOC <5>: Default Memory Allocators. (line 26) * environment variable; PYTHONMALLOC <6>: Customize Memory Allocators. (line 129) * environment variable; PYTHONMALLOCSTATS: Environment variables. (line 280) * environment variable; PYTHONMALLOCSTATS <1>: Overview<3>. (line 78) * environment variable; PYTHONNOUSERSITE: PEP 370 Per-user site-packages Directory. (line 30) * environment variable; PYTHONNOUSERSITE <1>: Environment variables. (line 160) * environment variable; PYTHONNOUSERSITE <2>: Module contents<3>. (line 15) * environment variable; PYTHONNOUSERSITE <3>: Global configuration variables. (line 124) * environment variable; PYTHONOPTIMIZE: Miscellaneous options. (line 71) * environment variable; PYTHONOPTIMIZE <1>: Environment variables. (line 60) * environment variable; PYTHONOPTIMIZE <2>: Global configuration variables. (line 129) * environment variable; PYTHONPATH: Changes in ‘python’ Command Behavior<2>. (line 8) * environment variable; PYTHONPATH <1>: Changes in ‘python’ Command Behavior<2>. (line 9) * environment variable; PYTHONPATH <2>: The Module Search Path. (line 15) * environment variable; PYTHONPATH <3>: Standard Modules. (line 34) * environment variable; PYTHONPATH <4>: Standard Modules. (line 35) * environment variable; PYTHONPATH <5>: Miscellaneous options. (line 42) * environment variable; PYTHONPATH <6>: Environment variables. (line 24) * environment variable; PYTHONPATH <7>: Environment variables. (line 32) * environment variable; PYTHONPATH <8>: Environment variables. (line 39) * environment variable; PYTHONPATH <9>: Environment variables. (line 42) * environment variable; PYTHONPATH <10>: Excursus Setting environment variables. (line 38) * environment variable; PYTHONPATH <11>: Finding modules. (line 36) * environment variable; PYTHONPATH <12>: Finding modules. (line 59) * environment variable; PYTHONPATH <13>: Finding modules. (line 102) * environment variable; PYTHONPATH <14>: Configuration. (line 6) * environment variable; PYTHONPATH <15>: Installing your CGI script on a Unix system. (line 29) * environment variable; PYTHONPATH <16>: test support script_helper — Utilities for the Python execution tests. (line 26) * environment variable; PYTHONPATH <17>: sys — System-specific parameters and functions. (line 1062) * environment variable; PYTHONPATH <18>: sys — System-specific parameters and functions. (line 1072) * environment variable; PYTHONPATH <19>: Building C and C++ Extensions. (line 9) * environment variable; PYTHONPATH <20>: Embedding Python<2>. (line 39) * environment variable; PYTHONPATH <21>: Embedding Python<2>. (line 44) * environment variable; PYTHONPATH <22>: Global configuration variables. (line 56) * environment variable; PYTHONPATH <23>: PyConfig. (line 252) * environment variable; PYTHONPATH <24>: Modifying Python’s Search Path. (line 67) * environment variable; PYTHONPATH <25>: Modifying Python’s Search Path. (line 68) * environment variable; PYTHONPROFILEIMPORTTIME: Other Language Changes<2>. (line 47) * environment variable; PYTHONPROFILEIMPORTTIME <1>: Miscellaneous options. (line 223) * environment variable; PYTHONPROFILEIMPORTTIME <2>: Environment variables. (line 230) * environment variable; PYTHONPYCACHEPREFIX: Parallel filesystem cache for compiled bytecode files. (line 6) * environment variable; PYTHONPYCACHEPREFIX <1>: Miscellaneous options. (line 257) * environment variable; PYTHONPYCACHEPREFIX <2>: Environment variables. (line 115) * environment variable; PYTHONPYCACHEPREFIX <3>: sys — System-specific parameters and functions. (line 303) * environment variable; PYTHONSHOWALLOCCOUNT: Two new environment variables for debug mode. (line 11) * environment variable; PYTHONSHOWREFCOUNT: Two new environment variables for debug mode. (line 7) * environment variable; PYTHONSTARTUP: sys<6>. (line 17) * environment variable; PYTHONSTARTUP <1>: sys<6>. (line 21) * environment variable; PYTHONSTARTUP <2>: The Interactive Startup File. (line 8) * environment variable; PYTHONSTARTUP <3>: Miscellaneous options. (line 50) * environment variable; PYTHONSTARTUP <4>: Environment variables. (line 46) * environment variable; PYTHONSTARTUP <5>: Example. (line 10) * environment variable; PYTHONSTARTUP <6>: Startup and code execution. (line 7) * environment variable; PYTHONSTARTUP <7>: sys — System-specific parameters and functions. (line 957) * environment variable; PYTHONSTARTUP <8>: Readline configuration. (line 12) * environment variable; PYTHONTHREADDEBUG: Debug-mode variables. (line 8) * environment variable; PYTHONTRACEMALLOC: Environment variables. (line 219) * environment variable; PYTHONTRACEMALLOC <1>: tracemalloc — Trace memory allocations. (line 25) * environment variable; PYTHONTRACEMALLOC <2>: tracemalloc — Trace memory allocations. (line 32) * environment variable; PYTHONTRACEMALLOC <3>: Functions<9>. (line 68) * environment variable; PYTHONUNBUFFERED: Miscellaneous options. (line 140) * environment variable; PYTHONUNBUFFERED <1>: Environment variables. (line 93) * environment variable; PYTHONUNBUFFERED <2>: Global configuration variables. (line 145) * environment variable; PYTHONUSERBASE: PEP 370 Per-user site-packages Directory. (line 23) * environment variable; PYTHONUSERBASE <1>: Environment variables. (line 170) * environment variable; PYTHONUSERBASE <2>: Module contents<3>. (line 39) * environment variable; PYTHONUSERBASE <3>: Module contents<3>. (line 66) * environment variable; PYTHONUSERSITE: test support script_helper — Utilities for the Python execution tests. (line 26) * environment variable; PYTHONUTF8: PEP 540 Forced UTF-8 Runtime Mode. (line 6) * environment variable; PYTHONUTF8 <1>: Miscellaneous options. (line 252) * environment variable; PYTHONUTF8 <2>: Environment variables. (line 369) * environment variable; PYTHONUTF8 <3>: Environment variables. (line 386) * environment variable; PYTHONUTF8 <4>: UTF-8 mode. (line 17) * environment variable; PYTHONUTF8 <5>: sys — System-specific parameters and functions. (line 1505) * environment variable; PYTHONUTF8 <6>: Python Configuration. (line 14) * environment variable; PYTHONVERBOSE: Miscellaneous options. (line 151) * environment variable; PYTHONVERBOSE <1>: Environment variables. (line 98) * environment variable; PYTHONVERBOSE <2>: Global configuration variables. (line 156) * environment variable; PYTHONWARNINGS: warnings. (line 21) * environment variable; PYTHONWARNINGS <1>: Other Language Changes<7>. (line 158) * environment variable; PYTHONWARNINGS <2>: Changes to the Handling of Deprecation Warnings. (line 25) * environment variable; PYTHONWARNINGS <3>: Interpreter Changes. (line 6) * environment variable; PYTHONWARNINGS <4>: Miscellaneous options. (line 169) * environment variable; PYTHONWARNINGS <5>: Environment variables. (line 188) * environment variable; PYTHONWARNINGS <6>: Describing Warning Filters. (line 7) * environment variable; PYTHONWARNINGS <7>: Describing Warning Filters. (line 21) * environment variable; PYTHONWARNINGS <8>: Default Warning Filter. (line 7) * environment variable; PYTHON_DOM: Module Contents<4>. (line 23) * environment variable; PY_PYTHON: Customizing default Python versions. (line 18) * environment variable; SOURCE_DATE_EPOCH: py_compile<2>. (line 7) * environment variable; SOURCE_DATE_EPOCH <1>: py_compile — Compile Python source files. (line 65) * environment variable; SOURCE_DATE_EPOCH <2>: py_compile — Compile Python source files. (line 81) * environment variable; SOURCE_DATE_EPOCH <3>: py_compile — Compile Python source files. (line 85) * environment variable; SOURCE_DATE_EPOCH <4>: Command-line use. (line 85) * environment variable; SSLKEYLOGFILE: Context creation. (line 33) * environment variable; SSLKEYLOGFILE <1>: Context creation. (line 67) * environment variable; SSL_CERT_FILE: LibreSSL support. (line 15) * environment variable; SSL_CERT_PATH: LibreSSL support. (line 15) * environment variable; SystemRoot: Popen Constructor. (line 234) * environment variable; TCL_LIBRARY: How do I freeze Tkinter applications?. (line 11) * environment variable; TEMP: tempfile — Generate temporary files and directories. (line 239) * environment variable; TERM: Functions<3>. (line 440) * environment variable; TERM <1>: Functions<3>. (line 467) * environment variable; TK_LIBRARY: How do I freeze Tkinter applications?. (line 11) * environment variable; TMP: tempfile — Generate temporary files and directories. (line 241) * environment variable; TMPDIR: tempfile — Generate temporary files and directories. (line 237) * environment variable; TZ: Functions<2>. (line 508) * environment variable; TZ <1>: Functions<2>. (line 509) * environment variable; TZ <2>: Functions<2>. (line 517) * environment variable; TZ <3>: Functions<2>. (line 522) * environment variable; TZ <4>: Functions<2>. (line 524) * environment variable; TZ <5>: Functions<2>. (line 584) * environment variable; USER: getpass — Portable password input. (line 38) * environment variable; USERNAME: Process Parameters. (line 221) * environment variable; USERNAME <1>: getpass — Portable password input. (line 39) * environment variable; USERPROFILE: os path. (line 14) * environment variable; USERPROFILE <1>: Changes in the Python API. (line 115) * environment variable; USERPROFILE <2>: os path — Common pathname manipulations. (line 146) * environment variable; USERPROFILE <3>: Location and names of config files. (line 67) * environment variable; USER_BASE: New and Improved Modules. (line 469) * environment variable; VIRTUAL_ENV: Creating virtual environments. (line 129) * environment variables; deleting: Process Parameters. (line 501) * environment variables; setting: Process Parameters. (line 318) * EnvironmentError: Concrete exceptions. (line 394) * Environments; virtual: venv — Creation of virtual environments. (line 10) * EnvironmentVarGuard (class in test.support): test support — Utilities for the Python test suite. (line 1025) * ENXIO (in module errno): errno — Standard errno system symbols. (line 51) * eof (bz2.BZ2Decompressor attribute): Incremental de compression. (line 72) * eof (lzma.LZMADecompressor attribute): Compressing and decompressing data in memory. (line 165) * eof (shlex.shlex attribute): shlex Objects. (line 178) * eof (ssl.MemoryBIO attribute): Memory BIO Support<2>. (line 143) * eof (zlib.Decompress attribute): zlib — Compression compatible with gzip. (line 248) * EOFError: Concrete exceptions. (line 19) * EOFError (built-in exception): File Objects. (line 41) * eof_received() (asyncio.BufferedProtocol method): Buffered Streaming Protocols. (line 42) * eof_received() (asyncio.Protocol method): Streaming Protocols. (line 30) * EOPNOTSUPP (in module errno): errno — Standard errno system symbols. (line 407) * EOVERFLOW (in module errno): errno — Standard errno system symbols. (line 327) * EPERM (in module errno): errno — Standard errno system symbols. (line 26) * EPFNOSUPPORT (in module errno): errno — Standard errno system symbols. (line 411) * epilogue (email.message.EmailMessage attribute): email message Representing an email message. (line 704) * epilogue (email.message.Message attribute): email message Message Representing an email message using the compat32 API. (line 714) * EPIPE (in module errno): errno — Standard errno system symbols. (line 155) * epoch: time — Time access and conversions. (line 18) * epoll() (in module select): select — Waiting for I/O completion. (line 50) * EpollSelector (class in selectors): Classes<3>. (line 175) * EPROTO (in module errno): errno — Standard errno system symbols. (line 311) * EPROTONOSUPPORT (in module errno): errno — Standard errno system symbols. (line 399) * EPROTOTYPE (in module errno): errno — Standard errno system symbols. (line 391) * eq() (in module operator): operator — Standard operators as functions. (line 24) * EQEQUAL (in module token): token — Constants used with Python parse trees. (line 134) * EQUAL (in module token): token — Constants used with Python parse trees. (line 114) * ERA (in module locale): locale — Internationalization services. (line 264) * ERANGE (in module errno): errno — Standard errno system symbols. (line 163) * erase() (curses.window method): Window Objects. (line 218) * erasechar() (in module curses): Functions<3>. (line 114) * ERA_D_FMT (in module locale): locale — Internationalization services. (line 286) * ERA_D_T_FMT (in module locale): locale — Internationalization services. (line 281) * ERA_T_FMT (in module locale): locale — Internationalization services. (line 291) * EREMCHG (in module errno): errno — Standard errno system symbols. (line 339) * EREMOTE (in module errno): errno — Standard errno system symbols. (line 291) * EREMOTEIO (in module errno): errno — Standard errno system symbols. (line 511) * ERESTART (in module errno): errno — Standard errno system symbols. (line 367) * erf() (in module math): Special functions. (line 6) * erfc() (in module math): Special functions. (line 20) * EROFS (in module errno): errno — Standard errno system symbols. (line 147) * ERR (in module curses): Constants<6>. (line 8) * errcheck (ctypes._FuncPtr attribute): Foreign functions. (line 59) * errcode (xmlrpc.client.ProtocolError attribute): ProtocolError Objects. (line 17) * errmsg (xmlrpc.client.ProtocolError attribute): ProtocolError Objects. (line 21) * errno (module): errno — Standard errno system symbols. (line 6) * errno (OSError attribute): Concrete exceptions. (line 135) * error: Module Contents. (line 353) * error <1>: Functions and Exceptions. (line 8) * error <2>: copy — Shallow and deep copy operations. (line 26) * Error: Directory and files operations. (line 400) * error <3>: dbm — Interfaces to Unix “databases”. (line 16) * error <4>: dbm gnu — GNU’s reinterpretation of dbm. (line 21) * error <5>: dbm ndbm — Interface based on ndbm. (line 21) * error <6>: dbm dumb — Portable DBM implementation. (line 24) * Error <1>: Exceptions<4>. (line 10) * error <7>: zlib — Compression compatible with gzip. (line 24) * Error <2>: Module Contents<3>. (line 265) * Error <3>: Exceptions<5>. (line 6) * Error <4>: Exceptions<6>. (line 8) * error <8>: os — Miscellaneous operating system interfaces. (line 42) * error <9>: getopt — C-style parser for command line options. (line 85) * error <10>: Functions<3>. (line 8) * error <11>: _thread — Low-level threading API. (line 21) * error <12>: Exceptions<11>. (line 6) * error <13>: select — Waiting for I/O completion. (line 24) * Error <5>: Exceptions<14>. (line 9) * Error <6>: binhex — Encode and decode binhex4 files. (line 33) * Error <7>: binascii — Convert between binary and ASCII. (line 174) * Error <8>: uu — Encode and decode uuencode files. (line 51) * error <14>: xml parsers expat — Fast XML parsing using Expat. (line 31) * Error <9>: webbrowser — Convenient Web-browser controller. (line 44) * error <15>: audioop — Manipulate raw audio data. (line 26) * Error <10>: sunau — Read and write Sun AU files. (line 75) * Error <11>: wave — Read and write WAV files. (line 55) * Error <12>: locale — Internationalization services. (line 22) * error <16>: resource — Resource usage information. (line 17) * error <17>: nis — Interface to Sun’s NIS Yellow Pages. (line 54) * error handling: Exceptions<2>. (line 6) * error() (argparse.ArgumentParser method): Exiting methods. (line 18) * error() (in module logging): Module-Level Functions. (line 133) * error() (logging.Logger method): Logger Objects. (line 229) * error() (urllib.request.OpenerDirector method): OpenerDirector Objects. (line 58) * error() (xml.sax.handler.ErrorHandler method): ErrorHandler Objects. (line 16) * ErrorByteIndex (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 132) * errorcode (in module errno): errno — Standard errno system symbols. (line 13) * ErrorCode (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 136) * ErrorColumnNumber (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 142) * ErrorHandler (class in xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 38) * ErrorLineNumber (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 146) * errors: Exceptions<2>. (line 6) * errors (io.TextIOBase attribute): Text I/O<2>. (line 20) * errors (unittest.TestLoader attribute): Loading and running tests. (line 17) * errors (unittest.TestResult attribute): Loading and running tests. (line 237) * Errors; logging: logging — Logging facility for Python. (line 8) * ErrorString() (in module xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat. (line 42) * ERRORTOKEN (in module token): token — Constants used with Python parse trees. (line 252) * error_body (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 260) * error_content_type (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 149) * error_headers (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 253) * error_leader() (shlex.shlex method): shlex Objects. (line 69) * error_message_format (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 141) * error_output() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 225) * error_perm: ftplib — FTP protocol client. (line 124) * error_proto: ftplib — FTP protocol client. (line 129) * error_proto <1>: poplib — POP3 protocol client. (line 83) * error_received() (asyncio.DatagramProtocol method): Datagram Protocols. (line 15) * error_reply: ftplib — FTP protocol client. (line 114) * error_status (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 247) * error_temp: ftplib — FTP protocol client. (line 119) * escape (shlex.shlex attribute): shlex Objects. (line 110) * escape sequence: String and Bytes literals. (line 72) * escape() (in module glob): glob — Unix style pathname pattern expansion. (line 62) * escape() (in module html): html — HyperText Markup Language support. (line 12) * escape() (in module re): Module Contents. (line 316) * escape() (in module xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 14) * escapechar (csv.Dialect attribute): Dialects and Formatting Parameters. (line 35) * escapedquotes (shlex.shlex attribute): shlex Objects. (line 122) * ESHUTDOWN (in module errno): errno — Standard errno system symbols. (line 459) * ESOCKTNOSUPPORT (in module errno): errno — Standard errno system symbols. (line 403) * ESPIPE (in module errno): errno — Standard errno system symbols. (line 143) * ESRCH (in module errno): errno — Standard errno system symbols. (line 34) * ESRMNT (in module errno): errno — Standard errno system symbols. (line 303) * ESTALE (in module errno): errno — Standard errno system symbols. (line 491) * ESTRPIPE (in module errno): errno — Standard errno system symbols. (line 371) * ETIME (in module errno): errno — Standard errno system symbols. (line 275) * ETIMEDOUT (in module errno): errno — Standard errno system symbols. (line 467) * Etiny() (decimal.Context method): Context objects. (line 213) * ETOOMANYREFS (in module errno): errno — Standard errno system symbols. (line 463) * Etop() (decimal.Context method): Context objects. (line 219) * ETXTBSY (in module errno): errno — Standard errno system symbols. (line 131) * EUCLEAN (in module errno): errno — Standard errno system symbols. (line 495) * EUNATCH (in module errno): errno — Standard errno system symbols. (line 223) * EUSERS (in module errno): errno — Standard errno system symbols. (line 375) * eval() (built-in function): Built-in Functions. (line 473) * evaluation; order: Evaluation order. (line 6) * Event (class in asyncio): Event. (line 6) * Event (class in multiprocessing): Synchronization primitives. (line 42) * Event (class in threading): Event Objects. (line 14) * event scheduling: sched — Event scheduler. (line 8) * event() (msilib.Control method): GUI classes. (line 16) * Event() (multiprocessing.managers.SyncManager method): Managers. (line 166) * events (selectors.SelectorKey attribute): Classes<3>. (line 44) * events (widgets): Bindings and Events. (line 6) * EWOULDBLOCK (in module errno): errno — Standard errno system symbols. (line 191) * Example (class in doctest): Example Objects. (line 6) * example (doctest.DocTestFailure attribute): Debugging. (line 200) * example (doctest.UnexpectedException attribute): Debugging. (line 221) * examples (doctest.DocTest attribute): DocTest Objects. (line 17) * excel (class in csv): Module Contents<3>. (line 183) * excel_tab (class in csv): Module Contents<3>. (line 189) * except (2to3 fixer): Fixers. (line 82) * excepthook() (in module sys): cgitb — Traceback manager for CGI scripts. (line 33) * excepthook() (in module sys) <1>: sys — System-specific parameters and functions. (line 309) * excepthook() (in module threading): threading — Thread-based parallelism. (line 46) * exception: Exceptions<2>. (line 6) * exception <1>: The raise statement. (line 6) * Exception: Base classes. (line 37) * EXCEPTION (in module tkinter): File Handlers. (line 41) * exception handler: Exceptions<2>. (line 6) * exception() (asyncio.Future method): Future Object. (line 117) * exception() (asyncio.Task method): Task Object. (line 134) * exception() (concurrent.futures.Future method): Future Objects. (line 54) * exception() (in module logging): Module-Level Functions. (line 143) * exception() (logging.Logger method): Logger Objects. (line 244) * exception; AssertionError: The assert statement. (line 21) * exception; AttributeError: Attribute references. (line 10) * exception; chaining: The raise statement. (line 30) * exception; GeneratorExit: Generator-iterator methods. (line 47) * exception; GeneratorExit <1>: Asynchronous generator-iterator methods. (line 55) * exception; handler: The standard type hierarchy. (line 757) * exception; ImportError: The import statement. (line 6) * exception; NameError: Identifiers Names. (line 10) * exception; StopAsyncIteration: Asynchronous generator-iterator methods. (line 10) * exception; StopIteration: Generator-iterator methods. (line 12) * exception; StopIteration <1>: The yield statement. (line 6) * exception; TypeError: Unary arithmetic and bitwise operations. (line 19) * exception; ValueError: Shifting operations. (line 15) * exception; ZeroDivisionError: Binary arithmetic operations. (line 28) * exceptions; in CGI scripts: cgitb — Traceback manager for CGI scripts. (line 8) * exclusive; or: Binary bitwise operations. (line 15) * exc_info (doctest.UnexpectedException attribute): Debugging. (line 225) * exc_info (in module sys): The standard type hierarchy. (line 757) * exc_info() (in module sys): sys — System-specific parameters and functions. (line 352) * exc_info() (in module sys) <1>: Exceptions<18>. (line 45) * exc_msg (doctest.Example attribute): Example Objects. (line 31) * exc_type (traceback.TracebackException attribute): TracebackException Objects. (line 38) * EXDEV (in module errno): errno — Standard errno system symbols. (line 99) * exec (2to3 fixer): Fixers. (line 86) * exec() (built-in function): Built-in Functions. (line 519) * execfile (2to3 fixer): Fixers. (line 90) * execl() (in module os): Process Management. (line 53) * execle() (in module os): Process Management. (line 53) * execlp() (in module os): Process Management. (line 53) * execlpe() (in module os): Process Management. (line 53) * executable (in module sys): sys — System-specific parameters and functions. (line 391) * executable (in module sys) <1>: Process-wide parameters. (line 111) * Executable Zip Files: zipapp — Manage executable Python zip archives. (line 10) * executable_filename() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 451) * execute() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 481) * execute() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 109) * Execute() (msilib.View method): View Objects. (line 6) * execute() (sqlite3.Connection method): Connection Objects. (line 52) * execute() (sqlite3.Cursor method): Cursor Objects. (line 11) * executemany() (sqlite3.Connection method): Connection Objects. (line 59) * executemany() (sqlite3.Cursor method): Cursor Objects. (line 46) * executescript() (sqlite3.Connection method): Connection Objects. (line 66) * executescript() (sqlite3.Cursor method): Cursor Objects. (line 100) * execution model: Execution model. (line 6) * execution; frame: Structure of a program. (line 16) * execution; frame <1>: Class definitions. (line 6) * execution; stack: The standard type hierarchy. (line 757) * ExecutionLoader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 452) * Executor (class in concurrent.futures): Executor Objects. (line 6) * execv() (in module os): Process Management. (line 53) * execve() (in module os): Process Management. (line 53) * execvp() (in module os): Process Management. (line 53) * execvpe() (in module os): Process Management. (line 53) * exec_module (C function): Multi-phase initialization. (line 103) * exec_module() (importlib.abc.InspectLoader method): importlib abc – Abstract base classes related to import. (line 439) * exec_module() (importlib.abc.Loader method): importlib abc – Abstract base classes related to import. (line 182) * exec_module() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 586) * exec_module() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 326) * exec_prefix: Python-related paths and files. (line 7) * exec_prefix <1>: Include Files. (line 37) * exec_prefix <2>: Include Files. (line 48) * EXEC_PREFIX (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 23) * exec_prefix (in module sys): sys — System-specific parameters and functions. (line 374) * ExFileSelectBox (class in tkinter.tix): File Selectors. (line 34) * EXFULL (in module errno): errno — Standard errno system symbols. (line 243) * exists() (in module os.path): os path — Common pathname manipulations. (line 114) * exists() (pathlib.Path method): Methods<2>. (line 58) * exists() (tkinter.ttk.Treeview method): ttk Treeview. (line 95) * exists() (zipfile.Path method): Path Objects. (line 47) * exit (built-in variable): Constants added by the site module. (line 11) * exit(): Process Control. (line 17) * exit() (argparse.ArgumentParser method): Exiting methods. (line 6) * exit() (in module sys): sys — System-specific parameters and functions. (line 398) * exit() (in module _thread): _thread — Low-level threading API. (line 63) * exitcode (multiprocessing.Process attribute): Process and exceptions. (line 112) * exitfunc (2to3 fixer): Fixers. (line 96) * exitonclick() (in module turtle): Methods specific to Screen not inherited from TurtleScreen. (line 10) * ExitStack (class in contextlib): Utilities. (line 342) * exp() (decimal.Context method): Context objects. (line 284) * exp() (decimal.Decimal method): Decimal objects. (line 232) * exp() (in module cmath): Power and logarithmic functions<2>. (line 6) * exp() (in module math): Power and logarithmic functions. (line 6) * expand() (re.Match method): Match Objects. (line 17) * ExpandEnvironmentStrings() (in module winreg): Functions<11>. (line 233) * expandNode() (xml.dom.pulldom.DOMEventStream method): DOMEventStream Objects. (line 21) * expandtabs() (bytearray method): Bytes and Bytearray Operations. (line 414) * expandtabs() (bytes method): Bytes and Bytearray Operations. (line 414) * expandtabs() (str method): String Methods<2>. (line 82) * expanduser() (in module os.path): os path — Common pathname manipulations. (line 135) * expanduser() (pathlib.Path method): Methods<2>. (line 75) * expandvars() (in module os.path): os path — Common pathname manipulations. (line 158) * expand_tabs (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 156) * Expat: xml parsers expat — Fast XML parsing using Expat. (line 12) * ExpatError: xml parsers expat — Fast XML parsing using Expat. (line 25) * expect() (telnetlib.Telnet method): Telnet Objects. (line 121) * expected (asyncio.IncompleteReadError attribute): Exceptions<9>. (line 50) * expectedFailure() (in module unittest): Skipping tests and expected failures. (line 98) * expectedFailures (unittest.TestResult attribute): Loading and running tests. (line 257) * expires (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 49) * exploded (ipaddress.IPv4Address attribute): Address objects. (line 54) * exploded (ipaddress.IPv4Network attribute): Network objects. (line 109) * exploded (ipaddress.IPv6Address attribute): Address objects. (line 155) * exploded (ipaddress.IPv6Network attribute): Network objects. (line 318) * expm1() (in module math): Power and logarithmic functions. (line 12) * expovariate() (in module random): Real-valued distributions. (line 38) * expr() (in module parser): Creating ST Objects. (line 10) * expression: Expressions. (line 6) * expression <1>: Glossary. (line 397) * expression; list: Expression lists. (line 6) * expression; list <1>: Expression statements. (line 6) * expression; list <2>: Expression statements. (line 6) * expression; statement: Expression statements. (line 6) * expunge() (imaplib.IMAP4 method): IMAP4 Objects. (line 93) * extend() (array.array method): array — Efficient arrays of numeric values. (line 148) * extend() (collections.deque method): deque objects. (line 59) * extend() (sequence method): Mutable Sequence Types. (line 16) * extend() (xml.etree.ElementTree.Element method): Element Objects. (line 93) * ExtendedContext (class in decimal): Context objects. (line 58) * ExtendedInterpolation (class in configparser): Interpolation of values. (line 40) * EXTENDED_ARG (opcode): Python Bytecode Instructions. (line 868) * extendleft() (collections.deque method): deque objects. (line 64) * extend_path() (in module pkgutil): pkgutil — Package extension utility. (line 19) * Extension (class in distutils.core): distutils core — Core Distutils functionality. (line 176) * extension module: Glossary. (line 408) * extension; module: The standard type hierarchy. (line 6) * ExtensionFileLoader (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 300) * extensions_map (http.server.SimpleHTTPRequestHandler attribute): http server — HTTP servers. (line 349) * EXTENSION_SUFFIXES (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 50) * External Data Representation: Data stream format. (line 6) * External Data Representation <1>: xdrlib — Encode and decode XDR data. (line 8) * ExternalClashError: Exceptions<14>. (line 25) * ExternalEntityParserCreate() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 44) * ExternalEntityRefHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 333) * external_attr (zipfile.ZipInfo attribute): ZipInfo Objects. (line 127) * extra (zipfile.ZipInfo attribute): ZipInfo Objects. (line 93) * extract() (tarfile.TarFile method): TarFile Objects. (line 162) * extract() (traceback.StackSummary class method): StackSummary Objects. (line 13) * extract() (zipfile.ZipFile method): ZipFile Objects. (line 158) * extractall() (tarfile.TarFile method): TarFile Objects. (line 136) * extractall() (zipfile.ZipFile method): ZipFile Objects. (line 185) * ExtractError: tarfile — Read and write tar archive files. (line 201) * extractfile() (tarfile.TarFile method): TarFile Objects. (line 190) * extract_cookies() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 30) * extract_stack() (in module traceback): traceback — Print or retrieve a stack traceback. (line 96) * extract_tb() (in module traceback): traceback — Print or retrieve a stack traceback. (line 83) * extract_version (zipfile.ZipInfo attribute): ZipInfo Objects. (line 107) * extsep (in module os): Miscellaneous System Information. (line 109) * EX_CANTCREAT (in module os): Process Management. (line 202) * EX_CONFIG (in module os): Process Management. (line 238) * EX_DATAERR (in module os): Process Management. (line 151) * EX_IOERR (in module os): Process Management. (line 209) * EX_NOHOST (in module os): Process Management. (line 170) * EX_NOINPUT (in module os): Process Management. (line 157) * EX_NOPERM (in module os): Process Management. (line 231) * EX_NOTFOUND (in module os): Process Management. (line 245) * EX_NOUSER (in module os): Process Management. (line 164) * EX_OK (in module os): Process Management. (line 138) * EX_OSERR (in module os): Process Management. (line 188) * EX_OSFILE (in module os): Process Management. (line 195) * EX_PROTOCOL (in module os): Process Management. (line 224) * EX_SOFTWARE (in module os): Process Management. (line 182) * EX_TEMPFAIL (in module os): Process Management. (line 216) * EX_UNAVAILABLE (in module os): Process Management. (line 176) * EX_USAGE (in module os): Process Management. (line 144) * f"; formatted string literal: String and Bytes literals. (line 62) * f’; formatted string literal: String and Bytes literals. (line 62) * f-string: String literal concatenation. (line 24) * f-string <1>: Glossary. (line 413) * fabs() (in module math): Number-theoretic and representation functions. (line 36) * factorial() (in module math): Number-theoretic and representation functions. (line 40) * factory() (importlib.util.LazyLoader class method): importlib util – Utility code for importers. (line 255) * fail() (unittest.TestCase method): Test cases. (line 664) * failfast (unittest.TestResult attribute): Loading and running tests. (line 288) * failureException (unittest.TestCase attribute): Test cases. (line 669) * failures (unittest.TestResult attribute): Loading and running tests. (line 243) * FAIL_FAST (in module doctest): Option Flags. (line 151) * FakePath (class in test.support): test support — Utilities for the Python test suite. (line 1112) * False: The standard type hierarchy. (line 93) * false: Truth Value Testing. (line 6) * False <1>: Truth Value Testing. (line 23) * False <2>: Boolean Values. (line 15) * False (Built-in object): Truth Value Testing. (line 15) * False (built-in variable): Built-in Constants. (line 8) * family (socket.socket attribute): Socket Objects. (line 595) * FancyGetopt (class in distutils.fancy_getopt): distutils fancy_getopt — Wrapper around the standard getopt module. (line 36) * FancyURLopener (class in urllib.request): Legacy interface. (line 147) * fancy_getopt() (in module distutils.fancy_getopt): distutils fancy_getopt — Wrapper around the standard getopt module. (line 20) * fast (pickle.Pickler attribute): Module Interface. (line 214) * FastChildWatcher (class in asyncio): Process Watchers. (line 132) * fatalError() (xml.sax.handler.ErrorHandler method): ErrorHandler Objects. (line 24) * Fault (class in xmlrpc.client): Fault Objects. (line 6) * faultCode (xmlrpc.client.Fault attribute): Fault Objects. (line 11) * faulthandler (module): faulthandler — Dump the Python traceback. (line 6) * faultString (xmlrpc.client.Fault attribute): Fault Objects. (line 15) * fchdir() (in module os): Files and Directories. (line 268) * fchmod() (in module os): File Descriptor Operations. (line 97) * fchown() (in module os): File Descriptor Operations. (line 108) * FCICreate() (in module msilib): msilib — Read and write Microsoft Installer files. (line 26) * fcntl (module): fcntl — The fcntl and ioctl system calls. (line 6) * fcntl() (in module fcntl): fcntl — The fcntl and ioctl system calls. (line 28) * fd (selectors.SelectorKey attribute): Classes<3>. (line 40) * fd() (in module turtle): Turtle motion. (line 6) * fdatasync() (in module os): File Descriptor Operations. (line 120) * fdopen() (in module os): File Object Creation. (line 9) * fd_count() (in module test.support): test support — Utilities for the Python test suite. (line 242) * Feature (class in msilib): Features<3>. (line 6) * feature_external_ges (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 76) * feature_external_pes (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 83) * feature_namespaces (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 48) * feature_namespace_prefixes (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 55) * feature_string_interning (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 62) * feature_validation (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 69) * feed() (email.parser.BytesFeedParser method): FeedParser API. (line 56) * feed() (html.parser.HTMLParser method): HTMLParser Methods. (line 8) * feed() (xml.etree.ElementTree.XMLParser method): XMLParser Objects. (line 27) * feed() (xml.etree.ElementTree.XMLPullParser method): XMLPullParser Objects. (line 18) * feed() (xml.sax.xmlreader.IncrementalParser method): IncrementalParser Objects. (line 9) * FeedParser (class in email.parser): FeedParser API. (line 71) * fetch() (imaplib.IMAP4 method): IMAP4 Objects. (line 99) * Fetch() (msilib.View method): View Objects. (line 18) * fetchall() (sqlite3.Cursor method): Cursor Objects. (line 162) * fetchmany() (sqlite3.Cursor method): Cursor Objects. (line 142) * fetchone() (sqlite3.Cursor method): Cursor Objects. (line 137) * fflags (select.kevent attribute): Kevent Objects. (line 90) * Field (class in dataclasses): Module-level decorators classes and functions. (line 241) * field() (in module dataclasses): Module-level decorators classes and functions. (line 153) * fieldnames (csv.csvreader attribute): Reader Objects. (line 30) * fields (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 94) * fields() (in module dataclasses): Module-level decorators classes and functions. (line 261) * field_size_limit() (in module csv): Module Contents<3>. (line 95) * file (pyclbr.Class attribute): Class Objects<2>. (line 9) * file (pyclbr.Function attribute): Function Objects. (line 9) * file object: Glossary. (line 419) * file object; io module: Overview. (line 6) * file object; open() built-in function: Built-in Functions. (line 1023) * file-like object: Glossary. (line 435) * file; byte-code: py_compile — Compile Python source files. (line 8) * file; byte-code <1>: imp — Access the import internals. (line 19) * file; copying: shutil — High-level file operations. (line 8) * file; large files: Large File Support. (line 6) * file; mime.types: mimetypes — Map filenames to MIME types. (line 124) * file; modes: Built-in Functions. (line 1047) * filecmp (module): filecmp — File and Directory Comparisons. (line 6) * fileConfig() (in module logging.config): Configuration functions. (line 61) * FileCookieJar (class in http.cookiejar): http cookiejar — Cookie handling for HTTP clients. (line 56) * FileEntry (class in tkinter.tix): File Selectors. (line 50) * FileExistsError: OS exceptions. (line 61) * FileFinder (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 160) * FileHandler (class in logging): FileHandler. (line 10) * FileHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 416) * FileInput (class in fileinput): fileinput — Iterate over lines from multiple input streams. (line 134) * fileinput (module): fileinput — Iterate over lines from multiple input streams. (line 6) * FileIO (class in io): Raw File I/O. (line 6) * filelineno() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 99) * FileLoader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 471) * filemode() (in module stat): stat — Interpreting stat results. (line 121) * filename (doctest.DocTest attribute): DocTest Objects. (line 36) * filename (http.cookiejar.FileCookieJar attribute): CookieJar and FileCookieJar Objects. (line 153) * filename (OSError attribute): Concrete exceptions. (line 157) * filename (traceback.TracebackException attribute): TracebackException Objects. (line 42) * filename (tracemalloc.Frame attribute): Frame. (line 13) * filename (zipfile.ZipFile attribute): ZipFile Objects. (line 298) * filename (zipfile.ZipInfo attribute): ZipInfo Objects. (line 50) * filename() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 81) * filename2 (OSError attribute): Concrete exceptions. (line 157) * filenames; pathname expansion: glob — Unix style pathname pattern expansion. (line 8) * filenames; wildcard expansion: fnmatch — Unix filename pattern matching. (line 8) * filename_only (in module tabnanny): tabnanny — Detection of ambiguous indentation. (line 31) * filename_pattern (tracemalloc.Filter attribute): Filter. (line 53) * fileno() (http.client.HTTPResponse method): HTTPResponse Objects. (line 36) * fileno() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 86) * fileno() (io.IOBase method): I/O Base Classes. (line 63) * fileno() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 31) * fileno() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 28) * fileno() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 14) * fileno() (select.devpoll method): /dev/poll Polling Objects. (line 24) * fileno() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 73) * fileno() (select.kqueue method): Kqueue Objects. (line 14) * fileno() (selectors.DevpollSelector method): Classes<3>. (line 188) * fileno() (selectors.EpollSelector method): Classes<3>. (line 179) * fileno() (selectors.KqueueSelector method): Classes<3>. (line 199) * fileno() (socket.socket method): Socket Objects. (line 110) * fileno() (socketserver.BaseServer method): Server Objects<2>. (line 14) * fileno() (telnetlib.Telnet method): Telnet Objects. (line 97) * FileNotFoundError: OS exceptions. (line 66) * fileobj (selectors.SelectorKey attribute): Classes<3>. (line 36) * FileSelectBox (class in tkinter.tix): File Selectors. (line 42) * FileType (class in argparse): FileType objects. (line 6) * FileWrapper (class in wsgiref.util): wsgiref util – WSGI environment utilities. (line 114) * FILE_ATTRIBUTE_ARCHIVE (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_COMPRESSED (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_DEVICE (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_DIRECTORY (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_ENCRYPTED (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_HIDDEN (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_INTEGRITY_STREAM (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_NORMAL (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_NOT_CONTENT_INDEXED (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_NO_SCRUB_DATA (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_OFFLINE (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_READONLY (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_REPARSE_POINT (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_SPARSE_FILE (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_SYSTEM (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_TEMPORARY (in module stat): stat — Interpreting stat results. (line 394) * FILE_ATTRIBUTE_VIRTUAL (in module stat): stat — Interpreting stat results. (line 394) * file_created() (built-in function): The Postinstallation script. (line 23) * file_dispatcher (class in asyncore): asyncore — Asynchronous socket handler. (line 256) * file_open() (urllib.request.FileHandler method): FileHandler Objects. (line 6) * file_size (zipfile.ZipInfo attribute): ZipInfo Objects. (line 143) * file_wrapper (class in asyncore): asyncore — Asynchronous socket handler. (line 266) * fill() (in module textwrap): textwrap — Text wrapping and filling. (line 29) * fill() (textwrap.TextWrapper method): textwrap — Text wrapping and filling. (line 285) * fillcolor() (in module turtle): Color control. (line 58) * filling() (in module turtle): Filling. (line 6) * filter (2to3 fixer): Fixers. (line 101) * Filter (class in logging): Filter Objects. (line 13) * Filter (class in tracemalloc): Filter. (line 6) * filter (select.kevent attribute): Kevent Objects. (line 15) * filter() (built-in function): Built-in Functions. (line 565) * filter() (in module curses): Functions<3>. (line 121) * filter() (in module fnmatch): fnmatch — Unix filename pattern matching. (line 65) * filter() (logging.Filter method): Filter Objects. (line 20) * filter() (logging.Handler method): Handler Objects. (line 60) * filter() (logging.Logger method): Logger Objects. (line 259) * filterfalse() (in module itertools): Itertool functions. (line 284) * filterwarnings() (in module warnings): Available Functions. (line 77) * FILTER_DIR (in module unittest.mock): FILTER_DIR. (line 6) * filter_traces() (tracemalloc.Snapshot method): Snapshot. (line 35) * Final (in module typing): Classes functions and decorators. (line 931) * final() (in module typing): Classes functions and decorators. (line 691) * finalization, of objects: Finalization and De-allocation. (line 6) * finalize (class in weakref): weakref — Weak references. (line 226) * finalizer: Basic customization. (line 56) * finalize_options() (distutils.cmd.Command method): Creating a new Distutils command. (line 30) * find() (bytearray method): Bytes and Bytearray Operations. (line 78) * find() (bytes method): Bytes and Bytearray Operations. (line 78) * find() (doctest.DocTestFinder method): DocTestFinder objects. (line 32) * find() (in module gettext): Class-based API. (line 14) * find() (mmap.mmap method): mmap — Memory-mapped file support. (line 177) * find() (str method): String Methods<2>. (line 103) * find() (xml.etree.ElementTree.Element method): Element Objects. (line 101) * find() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 21) * findall() (in module re): Module Contents. (line 219) * findall() (re.Pattern method): Regular Expression Objects. (line 79) * findall() (xml.etree.ElementTree.Element method): Element Objects. (line 110) * findall() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 26) * findCaller() (logging.Logger method): Logger Objects. (line 276) * finder: Finders and loaders. (line 6) * finder <1>: Glossary. (line 439) * Finder (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 28) * finder; find_spec: The meta path. (line 6) * findfactor() (in module audioop): audioop — Manipulate raw audio data. (line 79) * findfile() (in module test.support): test support — Utilities for the Python test suite. (line 228) * findfit() (in module audioop): audioop — Manipulate raw audio data. (line 88) * finditer() (in module re): Module Contents. (line 231) * finditer() (re.Pattern method): Regular Expression Objects. (line 85) * findlabels() (in module dis): Analysis functions. (line 136) * findlinestarts() (in module dis): Analysis functions. (line 125) * findmatch() (in module mailcap): mailcap — Mailcap file handling. (line 24) * findmax() (in module audioop): audioop — Manipulate raw audio data. (line 99) * findtext() (xml.etree.ElementTree.Element method): Element Objects. (line 119) * findtext() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 31) * find_class() (pickle protocol): Restricting Globals. (line 6) * find_class() (pickle.Unpickler method): Module Interface. (line 286) * find_library() (in module ctypes.util): Utility functions. (line 89) * find_library_file() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 204) * find_loader() (importlib.abc.PathEntryFinder method): importlib abc – Abstract base classes related to import. (line 119) * find_loader() (importlib.machinery.FileFinder method): importlib machinery – Importers and path hooks. (line 197) * find_loader() (in module importlib): Functions<10>. (line 40) * find_loader() (in module pkgutil): pkgutil — Package extension utility. (line 77) * find_longest_match() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 64) * find_module() (imp.NullImporter method): imp — Access the import internals. (line 355) * find_module() (importlib.abc.Finder method): importlib abc – Abstract base classes related to import. (line 35) * find_module() (importlib.abc.MetaPathFinder method): importlib abc – Abstract base classes related to import. (line 67) * find_module() (importlib.abc.PathEntryFinder method): importlib abc – Abstract base classes related to import. (line 143) * find_module() (importlib.machinery.PathFinder class method): importlib machinery – Importers and path hooks. (line 139) * find_module() (in module imp): imp — Access the import internals. (line 41) * find_module() (zipimport.zipimporter method): zipimporter Objects. (line 19) * find_msvcrt() (in module ctypes.util): Utility functions. (line 98) * find_spec() (importlib.abc.MetaPathFinder method): importlib abc – Abstract base classes related to import. (line 52) * find_spec() (importlib.abc.PathEntryFinder method): importlib abc – Abstract base classes related to import. (line 106) * find_spec() (importlib.machinery.FileFinder method): importlib machinery – Importers and path hooks. (line 190) * find_spec() (importlib.machinery.PathFinder class method): importlib machinery – Importers and path hooks. (line 116) * find_spec() (in module importlib.util): importlib util – Utility code for importers. (line 97) * find_unused_port() (in module test.support): test support — Utilities for the Python test suite. (line 888) * find_user_password() (urllib.request.HTTPPasswordMgr method): HTTPPasswordMgr Objects. (line 16) * find_user_password() (urllib.request.HTTPPasswordMgrWithPriorAuth method): HTTPPasswordMgrWithPriorAuth Objects. (line 19) * finish() (socketserver.BaseRequestHandler method): Request Handler Objects. (line 35) * finish_request() (socketserver.BaseServer method): Server Objects<2>. (line 125) * firstChild (xml.dom.Node attribute): Node Objects. (line 54) * firstkey() (dbm.gnu.gdbm method): dbm gnu — GNU’s reinterpretation of dbm. (line 85) * firstweekday() (in module calendar): calendar — General calendar-related functions. (line 297) * fix_missing_locations() (in module ast): ast Helpers. (line 81) * fix_sentence_endings (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 211) * Flag (class in enum): Module Contents<2>. (line 28) * flags (in module sys): sys — System-specific parameters and functions. (line 429) * flags (re.Pattern attribute): Regular Expression Objects. (line 101) * flags (select.kevent attribute): Kevent Objects. (line 52) * flag_bits (zipfile.ZipInfo attribute): ZipInfo Objects. (line 115) * flash() (in module curses): Functions<3>. (line 132) * flatten() (email.generator.BytesGenerator method): email generator Generating MIME documents. (line 80) * flatten() (email.generator.Generator method): email generator Generating MIME documents. (line 175) * flattening; objects: pickle — Python object serialization. (line 8) * float (built-in class): Built-in Functions. (line 582) * floating point literal: Numeric literals. (line 6) * floating point; literals: Numeric Types — int float complex. (line 19) * floating point; number: The standard type hierarchy. (line 107) * FloatingPointError: Concrete exceptions. (line 26) * FloatOperation (class in decimal): Signals. (line 100) * float_info (in module sys): sys — System-specific parameters and functions. (line 499) * float_repr_style (in module sys): sys — System-specific parameters and functions. (line 578) * flock() (in module fcntl): fcntl — The fcntl and ioctl system calls. (line 108) * floor division: Glossary. (line 450) * floor() (in module math): Numeric Types — int float complex. (line 104) * floor() (in module math) <1>: Number-theoretic and representation functions. (line 45) * floordiv() (in module operator): operator — Standard operators as functions. (line 88) * flush() (bz2.BZ2Compressor method): Incremental de compression. (line 25) * flush() (formatter.writer method): The Writer Interface. (line 13) * flush() (io.BufferedWriter method): Buffered Streams. (line 121) * flush() (io.IOBase method): I/O Base Classes. (line 69) * flush() (logging.Handler method): Handler Objects. (line 68) * flush() (logging.handlers.BufferingHandler method): MemoryHandler. (line 30) * flush() (logging.handlers.MemoryHandler method): MemoryHandler. (line 60) * flush() (logging.StreamHandler method): StreamHandler. (line 25) * flush() (lzma.LZMACompressor method): Compressing and decompressing data in memory. (line 91) * flush() (mailbox.Mailbox method): Mailbox objects. (line 242) * flush() (mailbox.Maildir method): Maildir. (line 102) * flush() (mailbox.MH method): MH. (line 99) * flush() (mmap.mmap method): mmap — Memory-mapped file support. (line 187) * flush() (zlib.Compress method): zlib — Compression compatible with gzip. (line 207) * flush() (zlib.Decompress method): zlib — Compression compatible with gzip. (line 279) * flushinp() (in module curses): Functions<3>. (line 139) * FlushKey() (in module winreg): Functions<11>. (line 244) * flush_headers() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 274) * flush_softspace() (formatter.formatter method): The Formatter Interface. (line 83) * fma() (decimal.Context method): Context objects. (line 288) * fma() (decimal.Decimal method): Decimal objects. (line 270) * fmean() (in module statistics): Function details. (line 50) * fmod() (in module math): Number-theoretic and representation functions. (line 51) * FMT_BINARY (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 200) * FMT_XML (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 194) * fnmatch (module): fnmatch — Unix filename pattern matching. (line 6) * fnmatch() (in module fnmatch): fnmatch — Unix filename pattern matching. (line 40) * fnmatchcase() (in module fnmatch): fnmatch — Unix filename pattern matching. (line 59) * focus() (tkinter.ttk.Treeview method): ttk Treeview. (line 99) * fold (datetime.datetime attribute): datetime Objects. (line 298) * fold (datetime.time attribute): time Objects. (line 71) * fold() (email.headerregistry.BaseHeader method): email headerregistry Custom Header Objects. (line 72) * fold() (email.policy.Compat32 method): email policy Policy Objects. (line 584) * fold() (email.policy.EmailPolicy method): email policy Policy Objects. (line 450) * fold() (email.policy.Policy method): email policy Policy Objects. (line 319) * fold_binary() (email.policy.Compat32 method): email policy Policy Objects. (line 592) * fold_binary() (email.policy.EmailPolicy method): email policy Policy Objects. (line 470) * fold_binary() (email.policy.Policy method): email policy Policy Objects. (line 334) * for; in comprehensions: Displays for lists sets and dictionaries. (line 14) * forget() (in module test.support): test support — Utilities for the Python test suite. (line 162) * forget() (tkinter.ttk.Notebook method): ttk Notebook. (line 18) * fork() (in module os): Process Management. (line 251) * fork() (in module pty): pty — Pseudo-terminal utilities. (line 20) * ForkingMixIn (class in socketserver): Server Creation Notes. (line 28) * ForkingTCPServer (class in socketserver): Server Creation Notes. (line 62) * ForkingUDPServer (class in socketserver): Server Creation Notes. (line 62) * forkpty() (in module os): Process Management. (line 270) * Form (class in tkinter.tix): Form Geometry Manager. (line 9) * format (memoryview attribute): Memory Views. (line 416) * format (multiprocessing.shared_memory.ShareableList attribute): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 273) * format (struct.Struct attribute): Classes<2>. (line 55) * format() (built-in function): Built-in Functions. (line 643) * format() (built-in function); __str__() (object method): Basic customization. (line 129) * format() (in module locale): locale — Internationalization services. (line 407) * format() (logging.Formatter method): Formatter Objects. (line 49) * format() (logging.Handler method): Handler Objects. (line 102) * format() (pprint.PrettyPrinter method): PrettyPrinter Objects. (line 40) * format() (str method): String Methods<2>. (line 117) * format() (string.Formatter method): Custom String Formatting. (line 17) * format() (traceback.StackSummary method): StackSummary Objects. (line 36) * format() (traceback.TracebackException method): TracebackException Objects. (line 73) * format() (tracemalloc.Traceback method): Traceback. (line 25) * formataddr() (in module email.utils): email utils Miscellaneous utilities. (line 67) * formatargspec() (in module inspect): Classes and functions<2>. (line 92) * formatargvalues() (in module inspect): Classes and functions<2>. (line 121) * formatdate() (in module email.utils): email utils Miscellaneous utilities. (line 139) * FormatError: Exceptions<14>. (line 32) * FormatError() (in module ctypes): Utility functions. (line 108) * formatException() (logging.Formatter method): Formatter Objects. (line 110) * formatmonth() (calendar.HTMLCalendar method): calendar — General calendar-related functions. (line 169) * formatmonth() (calendar.TextCalendar method): calendar — General calendar-related functions. (line 134) * formatStack() (logging.Formatter method): Formatter Objects. (line 118) * formatted string literal: String literal concatenation. (line 24) * Formatter (class in logging): Formatter Objects. (line 26) * Formatter (class in string): Custom String Formatting. (line 13) * formatter (module): formatter — Generic output formatting. (line 6) * formatTime() (logging.Formatter method): Formatter Objects. (line 73) * formatting, string (%): printf-style String Formatting. (line 6) * formatting; bytearray (%): printf-style Bytes Formatting. (line 6) * formatting; bytes (%): printf-style Bytes Formatting. (line 6) * formatwarning() (in module warnings): Available Functions. (line 68) * formatyear() (calendar.HTMLCalendar method): calendar — General calendar-related functions. (line 175) * formatyear() (calendar.TextCalendar method): calendar — General calendar-related functions. (line 148) * formatyearpage() (calendar.HTMLCalendar method): calendar — General calendar-related functions. (line 180) * format_datetime() (in module email.utils): email utils Miscellaneous utilities. (line 160) * format_exc() (in module traceback): traceback — Print or retrieve a stack traceback. (line 137) * format_exception() (in module traceback): traceback — Print or retrieve a stack traceback. (line 124) * format_exception_only() (in module traceback): traceback — Print or retrieve a stack traceback. (line 113) * format_exception_only() (traceback.TracebackException method): TracebackException Objects. (line 88) * format_field() (string.Formatter method): Custom String Formatting. (line 102) * format_help() (argparse.ArgumentParser method): Printing help. (line 30) * format_list() (in module traceback): traceback — Print or retrieve a stack traceback. (line 103) * format_map() (str method): String Methods<2>. (line 147) * format_stack() (in module traceback): traceback — Print or retrieve a stack traceback. (line 146) * format_stack_entry() (bdb.Bdb method): bdb — Debugger framework. (line 344) * format_string() (in module locale): locale — Internationalization services. (line 390) * format_tb() (in module traceback): traceback — Print or retrieve a stack traceback. (line 142) * format_usage() (argparse.ArgumentParser method): Printing help. (line 25) * FORMAT_VALUE (opcode): Python Bytecode Instructions. (line 876) * Fortran contiguous: shape strides suboffsets. (line 25) * Fortran contiguous <1>: Glossary. (line 273) * forward() (in module turtle): Turtle motion. (line 6) * ForwardRef (class in typing): Classes functions and decorators. (line 597) * FOR_ITER (opcode): Python Bytecode Instructions. (line 686) * found_terminator() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 89) * fpathconf() (in module os): File Descriptor Operations. (line 129) * fqdn (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 90) * Fraction (class in fractions): fractions — Rational numbers. (line 16) * fractions (module): fractions — Rational numbers. (line 6) * Frame (class in tracemalloc): Frame. (line 6) * frame (tkinter.scrolledtext.ScrolledText attribute): tkinter scrolledtext — Scrolled Text Widget. (line 24) * FrameSummary (class in traceback): FrameSummary Objects. (line 11) * FrameType (in module types): Standard Interpreter Types. (line 190) * free(): Overview<3>. (line 33) * free; variable: Binding of names. (line 26) * freefunc (C type): Slot Type typedefs. (line 37) * freeze utility: Importing Modules<2>. (line 262) * freeze() (in module gc): gc — Garbage Collector interface. (line 182) * freeze_support() (in module multiprocessing): Miscellaneous<3>. (line 43) * frexp() (in module math): Number-theoretic and representation functions. (line 67) * from; import statement: Binding of names. (line 9) * from; import statement <1>: The import statement. (line 51) * from; yield from expression: Yield expressions. (line 63) * frombuf() (tarfile.TarInfo class method): TarInfo Objects. (line 19) * frombytes() (array.array method): array — Efficient arrays of numeric values. (line 156) * fromfd() (in module socket): Creating sockets. (line 146) * fromfd() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 77) * fromfd() (select.kqueue method): Kqueue Objects. (line 18) * fromfile() (array.array method): array — Efficient arrays of numeric values. (line 165) * fromhex() (bytearray class method): Bytearray Objects. (line 36) * fromhex() (bytes class method): Bytes Objects. (line 62) * fromhex() (float class method): Additional Methods on Float. (line 39) * fromisocalendar() (datetime.date class method): date Objects. (line 77) * fromisocalendar() (datetime.datetime class method): datetime Objects. (line 222) * fromisoformat() (datetime.date class method): date Objects. (line 63) * fromisoformat() (datetime.datetime class method): datetime Objects. (line 187) * fromisoformat() (datetime.time class method): time Objects. (line 113) * fromkeys() (collections.Counter method): Counter objects. (line 106) * fromkeys() (dict class method): Mapping Types — dict. (line 150) * fromlist() (array.array method): array — Efficient arrays of numeric values. (line 174) * fromordinal() (datetime.date class method): date Objects. (line 54) * fromordinal() (datetime.datetime class method): datetime Objects. (line 161) * fromshare() (in module socket): Creating sockets. (line 163) * fromstring() (array.array method): array — Efficient arrays of numeric values. (line 180) * fromstring() (in module xml.etree.ElementTree): Functions<6>. (line 99) * fromstringlist() (in module xml.etree.ElementTree): Functions<6>. (line 107) * fromtarfile() (tarfile.TarInfo class method): TarInfo Objects. (line 26) * fromtimestamp() (datetime.date class method): date Objects. (line 35) * fromtimestamp() (datetime.datetime class method): datetime Objects. (line 93) * fromunicode() (array.array method): array — Efficient arrays of numeric values. (line 186) * fromutc() (datetime.timezone method): timezone Objects. (line 61) * fromutc() (datetime.tzinfo method): tzinfo Objects. (line 163) * from_address() (ctypes._CData method): Data types. (line 42) * from_buffer() (ctypes._CData method): Data types. (line 19) * from_buffer_copy() (ctypes._CData method): Data types. (line 31) * from_bytes() (int class method): Additional Methods on Integer Types. (line 67) * from_callable() (inspect.Signature class method): Introspecting callables with the Signature object. (line 127) * from_decimal() (fractions.Fraction method): fractions — Rational numbers. (line 116) * from_exception() (traceback.TracebackException class method): TracebackException Objects. (line 63) * from_file() (zipfile.ZipInfo class method): ZipInfo Objects. (line 14) * from_float() (decimal.Decimal method): Decimal objects. (line 243) * from_float() (fractions.Fraction method): fractions — Rational numbers. (line 105) * from_iterable() (itertools.chain class method): Itertool functions. (line 98) * from_list() (traceback.StackSummary class method): StackSummary Objects. (line 29) * from_param() (ctypes._CData method): Data types. (line 51) * from_samples() (statistics.NormalDist class method): NormalDist objects. (line 45) * from_traceback() (dis.Bytecode class method): Bytecode analysis. (line 33) * FrozenImporter (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 80) * FrozenInstanceError: Exceptions<17>. (line 6) * frozenset (built-in class): Set Types — set frozenset. (line 33) * FrozenSet (class in typing): Classes functions and decorators. (line 278) * fsdecode() (in module os): Process Parameters. (line 88) * fsencode() (in module os): Process Parameters. (line 75) * fspath() (in module os): Process Parameters. (line 101) * fstat() (in module os): File Descriptor Operations. (line 151) * fstatvfs() (in module os): File Descriptor Operations. (line 163) * fstring: String literal concatenation. (line 24) * fsum() (in module math): Number-theoretic and representation functions. (line 75) * fsync() (in module os): File Descriptor Operations. (line 171) * fs_is_case_insensitive() (in module test.support): test support — Utilities for the Python test suite. (line 925) * FS_NONASCII (in module test.support): test support — Utilities for the Python test suite. (line 48) * FTP: urllib request Restrictions. (line 37) * FTP (class in ftplib): ftplib — FTP protocol client. (line 39) * FTP; ftplib (standard module): ftplib — FTP protocol client. (line 8) * FTP; protocol: urllib request Restrictions. (line 6) * FTP; protocol <1>: ftplib — FTP protocol client. (line 8) * FTPHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 426) * ftplib (module): ftplib — FTP protocol client. (line 6) * ftp_open() (urllib.request.FTPHandler method): FTPHandler Objects. (line 6) * FTP_TLS (class in ftplib): ftplib — FTP protocol client. (line 72) * ftruncate() (in module os): File Descriptor Operations. (line 184) * Full: queue — A synchronized queue class. (line 88) * full() (asyncio.Queue method): Queue. (line 32) * full() (multiprocessing.Queue method): Pipes and Queues. (line 114) * full() (queue.Queue method): Queue Objects. (line 22) * fullmatch() (in module re): Module Contents. (line 167) * fullmatch() (re.Pattern method): Regular Expression Objects. (line 56) * full_url (urllib.request.Request attribute): Request Objects. (line 11) * func (functools.partial attribute): partial Objects. (line 9) * funcattrs (2to3 fixer): Fixers. (line 105) * function: Glossary. (line 458) * Function (class in symtable): Examining Symbol Tables. (line 66) * function annotation: Glossary. (line 466) * function; annotations: Function Annotations. (line 6) * function; annotations <1>: Function definitions. (line 89) * function; argument: The standard type hierarchy. (line 292) * function; call: The standard type hierarchy. (line 292) * function; call <1>: Calls. (line 123) * function; call <2>: Calls. (line 132) * function; definition: The return statement. (line 6) * function; definition <1>: Function definitions. (line 6) * function; generator: The yield statement. (line 6) * function; name: Function definitions. (line 6) * function; name <1>: Function definitions. (line 6) * FunctionTestCase (class in unittest): Test cases. (line 895) * FunctionType (in module types): Standard Interpreter Types. (line 19) * functools (module): functools — Higher-order functions and operations on callable objects. (line 6) * funny_files (filecmp.dircmp attribute): The dircmp class. (line 95) * future (2to3 fixer): Fixers. (line 111) * Future (class in asyncio): Future Object. (line 6) * Future (class in concurrent.futures): Future Objects. (line 10) * future; statement: Future statements. (line 6) * FutureWarning: Warnings. (line 40) * fwalk() (in module os): Files and Directories. (line 1586) * f_back (frame attribute): The standard type hierarchy. (line 713) * f_builtins (frame attribute): The standard type hierarchy. (line 713) * f_code (frame attribute): The standard type hierarchy. (line 713) * f_contiguous (memoryview attribute): Memory Views. (line 475) * f_globals (frame attribute): The standard type hierarchy. (line 713) * f_lasti (frame attribute): The standard type hierarchy. (line 713) * f_lineno (frame attribute): The standard type hierarchy. (line 722) * f_locals (frame attribute): The standard type hierarchy. (line 713) * F_LOCK (in module os): File Descriptor Operations. (line 229) * F_OK (in module os): Files and Directories. (line 106) * F_TEST (in module os): File Descriptor Operations. (line 229) * F_TLOCK (in module os): File Descriptor Operations. (line 229) * f_trace (frame attribute): The standard type hierarchy. (line 722) * f_trace_lines (frame attribute): The standard type hierarchy. (line 722) * f_trace_opcodes (frame attribute): The standard type hierarchy. (line 722) * F_ULOCK (in module os): File Descriptor Operations. (line 229) * G.722: aifc — Read and write AIFF and AIFC files. (line 160) * gaierror: Exceptions<11>. (line 27) * gamma() (in module math): Special functions. (line 29) * gammavariate() (in module random): Real-valued distributions. (line 46) * garbage (in module gc): gc — Garbage Collector interface. (line 210) * garbage collection: Objects values and types. (line 37) * garbage collection <1>: Glossary. (line 498) * gather() (curses.textpad.Textbox method): Textbox objects. (line 109) * gather() (in module asyncio): Running Tasks Concurrently. (line 6) * gauss() (in module random): Real-valued distributions. (line 57) * gc (module): gc — Garbage Collector interface. (line 6) * gcd() (in module fractions): fractions — Rational numbers. (line 174) * gcd() (in module math): Number-theoretic and representation functions. (line 95) * gc_collect() (in module test.support): test support — Utilities for the Python test suite. (line 474) * ge() (in module operator): operator — Standard operators as functions. (line 24) * generate_help() (distutils.fancy_getopt.FancyGetopt method): distutils fancy_getopt — Wrapper around the standard getopt module. (line 68) * generate_tokens() (in module tokenize): Tokenizing Input. (line 38) * generator: Glossary. (line 507) * generator <1>: Glossary. (line 507) * Generator (class in collections.abc): Collections Abstract Base Classes. (line 150) * Generator (class in email.generator): email generator Generating MIME documents. (line 140) * Generator (class in typing): Classes functions and decorators. (line 391) * generator expression: Glossary. (line 529) * generator expression <1>: Glossary. (line 529) * generator iterator: Glossary. (line 517) * generator; expression: Generator expressions. (line 6) * generator; function: The standard type hierarchy. (line 444) * generator; function <1>: Yield expressions. (line 6) * generator; function <2>: The yield statement. (line 6) * generator; iterator: The standard type hierarchy. (line 444) * generator; iterator <1>: The yield statement. (line 6) * GeneratorExit: Concrete exceptions. (line 30) * GeneratorType (in module types): Standard Interpreter Types. (line 31) * Generic (class in typing): Classes functions and decorators. (line 47) * generic function: Glossary. (line 538) * generic; special; attribute: The standard type hierarchy. (line 13) * generic_visit() (ast.NodeVisitor method): ast Helpers. (line 136) * genops() (in module pickletools): Programmatic Interface<2>. (line 22) * gen_lib_options() (in module distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 14) * gen_preprocess_options() (in module distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 24) * gen_uuid() (in module msilib): msilib — Read and write Microsoft Installer files. (line 109) * geometric_mean() (in module statistics): Function details. (line 64) * get() (asyncio.Queue method): Queue. (line 40) * get() (configparser.ConfigParser method): ConfigParser Objects. (line 188) * get() (contextvars.Context method): Manual Context Management. (line 85) * get() (contextvars.ContextVar method): Context Variables. (line 30) * get() (dict method): Mapping Types — dict. (line 162) * get() (email.message.EmailMessage method): email message Representing an email message. (line 245) * get() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 353) * get() (in module webbrowser): webbrowser — Convenient Web-browser controller. (line 77) * get() (mailbox.Mailbox method): Mailbox objects. (line 140) * get() (multiprocessing.pool.AsyncResult method): Process Pools. (line 196) * get() (multiprocessing.Queue method): Pipes and Queues. (line 140) * get() (multiprocessing.SimpleQueue method): Pipes and Queues. (line 213) * get() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 60) * get() (queue.Queue method): Queue Objects. (line 44) * get() (queue.SimpleQueue method): SimpleQueue Objects. (line 40) * get() (tkinter.ttk.Combobox method): ttk Combobox. (line 15) * get() (tkinter.ttk.Spinbox method): ttk Spinbox. (line 8) * get() (types.MappingProxyType method): Standard Interpreter Types. (line 249) * get() (xml.etree.ElementTree.Element method): Element Objects. (line 64) * getacl() (imaplib.IMAP4 method): IMAP4 Objects. (line 106) * getaddresses() (in module email.utils): email utils Miscellaneous utilities. (line 81) * getaddrinfo() (asyncio.loop method): DNS. (line 6) * getaddrinfo() (in module socket): Other functions<2>. (line 17) * getallocatedblocks() (in module sys): sys — System-specific parameters and functions. (line 590) * getandroidapilevel() (in module sys): sys — System-specific parameters and functions. (line 605) * getannotation() (imaplib.IMAP4 method): IMAP4 Objects. (line 111) * getargspec() (in module inspect): Classes and functions<2>. (line 17) * getargvalues() (in module inspect): Classes and functions<2>. (line 81) * getatime() (in module os.path): os path — Common pathname manipulations. (line 170) * getattr() (built-in function): Built-in Functions. (line 676) * getattrfunc (C type): Slot Type typedefs. (line 53) * getAttribute() (xml.dom.Element method): Element Objects<2>. (line 31) * getAttributeNode() (xml.dom.Element method): Element Objects<2>. (line 37) * getAttributeNodeNS() (xml.dom.Element method): Element Objects<2>. (line 47) * getAttributeNS() (xml.dom.Element method): Element Objects<2>. (line 41) * getattrofunc (C type): Slot Type typedefs. (line 63) * getattr_static() (in module inspect): Fetching attributes statically. (line 16) * GetBase() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 31) * getbegyx() (curses.window method): Window Objects. (line 222) * getbkgd() (curses.window method): Window Objects. (line 226) * getblocking() (socket.socket method): Socket Objects. (line 153) * getboolean() (configparser.ConfigParser method): ConfigParser Objects. (line 222) * getbuffer() (io.BytesIO method): Buffered Streams. (line 21) * getbufferproc (C type): Slot Type typedefs. (line 105) * getByteStream() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 48) * getcallargs() (in module inspect): Classes and functions<2>. (line 140) * getcanvas() (in module turtle): Settings and special methods. (line 55) * getcapabilities() (nntplib.NNTP method): Methods<3>. (line 34) * getcaps() (in module mailcap): mailcap — Mailcap file handling. (line 62) * getch() (curses.window method): Window Objects. (line 231) * getch() (in module msvcrt): Console I/O. (line 10) * getCharacterStream() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 64) * getche() (in module msvcrt): Console I/O. (line 25) * getcheckinterval() (in module sys): sys — System-specific parameters and functions. (line 613) * getChild() (logging.Logger method): Logger Objects. (line 106) * getchildren() (xml.etree.ElementTree.Element method): Element Objects. (line 130) * getclasstree() (in module inspect): Classes and functions<2>. (line 6) * getclosurevars() (in module inspect): Classes and functions<2>. (line 170) * GetColumnInfo() (msilib.View method): View Objects. (line 12) * getColumnNumber() (xml.sax.xmlreader.Locator method): Locator Objects. (line 8) * getcomments() (in module inspect): Retrieving source code. (line 17) * getcompname() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 73) * getcompname() (sunau.AU_read method): AU_read Objects. (line 35) * getcompname() (wave.Wave_read method): Wave_read Objects. (line 35) * getcomptype() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 67) * getcomptype() (sunau.AU_read method): AU_read Objects. (line 30) * getcomptype() (wave.Wave_read method): Wave_read Objects. (line 31) * getContentHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 21) * getcontext() (in module decimal): Context objects. (line 14) * getcoroutinelocals() (in module inspect): Current State of Generators and Coroutines. (line 73) * getcoroutinestate() (in module inspect): Current State of Generators and Coroutines. (line 28) * getctime() (in module os.path): os path — Common pathname manipulations. (line 186) * getcwd() (in module os): Files and Directories. (line 280) * getcwdb() (in module os): Files and Directories. (line 284) * getcwdu (2to3 fixer): Fixers. (line 115) * getdecoder() (in module codecs): codecs — Codec registry and base classes. (line 107) * getdefaultencoding() (in module sys): sys — System-specific parameters and functions. (line 621) * getdefaultlocale() (in module locale): locale — Internationalization services. (line 301) * getdefaulttimeout() (in module socket): Other functions<2>. (line 332) * getdlopenflags() (in module sys): sys — System-specific parameters and functions. (line 626) * getdoc() (in module inspect): Retrieving source code. (line 6) * getDOMImplementation() (in module xml.dom): Module Contents<4>. (line 17) * getDTDHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 30) * getEffectiveLevel() (logging.Logger method): Logger Objects. (line 97) * getegid() (in module os): Process Parameters. (line 163) * getElementsByTagName() (xml.dom.Document method): Document Objects. (line 61) * getElementsByTagName() (xml.dom.Element method): Element Objects<2>. (line 14) * getElementsByTagNameNS() (xml.dom.Document method): Document Objects. (line 66) * getElementsByTagNameNS() (xml.dom.Element method): Element Objects<2>. (line 18) * getencoder() (in module codecs): codecs — Codec registry and base classes. (line 99) * getEncoding() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 32) * getEntityResolver() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 39) * getenv() (in module os): Process Parameters. (line 128) * getenvb() (in module os): Process Parameters. (line 140) * getErrorHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 50) * geteuid() (in module os): Process Parameters. (line 171) * getEvent() (xml.dom.pulldom.DOMEventStream method): DOMEventStream Objects. (line 11) * getEventCategory() (logging.handlers.NTEventLogHandler method): NTEventLogHandler. (line 43) * getEventType() (logging.handlers.NTEventLogHandler method): NTEventLogHandler. (line 49) * getException() (xml.sax.SAXException method): SAXException Objects. (line 13) * getFeature() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 69) * GetFieldCount() (msilib.Record method): Record Objects. (line 6) * getfile() (in module inspect): Retrieving source code. (line 26) * getfilesystemencodeerrors() (in module sys): sys — System-specific parameters and functions. (line 671) * getfilesystemencoding() (in module sys): sys — System-specific parameters and functions. (line 635) * getfirst() (cgi.FieldStorage method): Higher Level Interface. (line 56) * getfloat() (configparser.ConfigParser method): ConfigParser Objects. (line 215) * getfmts() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 80) * getfqdn() (in module socket): Other functions<2>. (line 71) * getframeinfo() (in module inspect): The interpreter stack. (line 46) * getframerate() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 59) * getframerate() (sunau.AU_read method): AU_read Objects. (line 22) * getframerate() (wave.Wave_read method): Wave_read Objects. (line 23) * getfullargspec() (in module inspect): Classes and functions<2>. (line 36) * getgeneratorlocals() (in module inspect): Current State of Generators and Coroutines. (line 53) * getgeneratorstate() (in module inspect): Current State of Generators and Coroutines. (line 12) * getgid() (in module os): Process Parameters. (line 177) * getgrall() (in module grp): grp — The group database. (line 57) * getgrgid() (in module grp): grp — The group database. (line 42) * getgrnam() (in module grp): grp — The group database. (line 52) * getgrouplist() (in module os): Process Parameters. (line 183) * getgroups() (in module os): Process Parameters. (line 193) * getheader() (http.client.HTTPResponse method): HTTPResponse Objects. (line 24) * getheaders() (http.client.HTTPResponse method): HTTPResponse Objects. (line 32) * gethostbyaddr() (in module socket): Process Parameters. (line 471) * gethostbyaddr() (in module socket) <1>: Other functions<2>. (line 120) * gethostbyname() (in module socket): Other functions<2>. (line 81) * gethostbyname_ex() (in module socket): Other functions<2>. (line 94) * gethostname() (in module socket): Process Parameters. (line 471) * gethostname() (in module socket) <1>: Other functions<2>. (line 109) * getincrementaldecoder() (in module codecs): codecs — Codec registry and base classes. (line 123) * getincrementalencoder() (in module codecs): codecs — Codec registry and base classes. (line 115) * getinfo() (zipfile.ZipFile method): ZipFile Objects. (line 91) * getinnerframes() (in module inspect): The interpreter stack. (line 63) * GetInputContext() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 37) * getint() (configparser.ConfigParser method): ConfigParser Objects. (line 208) * GetInteger() (msilib.Record method): Record Objects. (line 11) * getitem() (in module operator): operator — Standard operators as functions. (line 192) * getiterator() (xml.etree.ElementTree.Element method): Element Objects. (line 135) * getiterator() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 36) * getiterfunc (C type): Slot Type typedefs. (line 95) * getitimer() (in module signal): Module contents<2>. (line 370) * getkey() (curses.window method): Window Objects. (line 246) * GetLastError() (in module ctypes): Utility functions. (line 114) * getLength() (xml.sax.xmlreader.Attributes method): The Attributes Interface. (line 11) * getLevelName() (in module logging): Module-Level Functions. (line 203) * getline() (in module linecache): linecache — Random access to text lines. (line 23) * getLineNumber() (xml.sax.xmlreader.Locator method): Locator Objects. (line 12) * getlist() (cgi.FieldStorage method): Higher Level Interface. (line 67) * getloadavg() (in module os): Miscellaneous System Information. (line 48) * getlocale() (in module locale): locale — Internationalization services. (line 326) * getLogger() (in module logging): Module-Level Functions. (line 9) * getLoggerClass() (in module logging): Module-Level Functions. (line 21) * getlogin() (in module os): Process Parameters. (line 216) * getLogRecordFactory() (in module logging): Module-Level Functions. (line 32) * getmark() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 92) * getmark() (sunau.AU_read method): AU_read Objects. (line 77) * getmark() (wave.Wave_read method): Wave_read Objects. (line 62) * getmarkers() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 85) * getmarkers() (sunau.AU_read method): AU_read Objects. (line 73) * getmarkers() (wave.Wave_read method): Wave_read Objects. (line 58) * getmaxyx() (curses.window method): Window Objects. (line 253) * getmember() (tarfile.TarFile method): TarFile Objects. (line 101) * getmembers() (in module inspect): Types and members. (line 276) * getmembers() (tarfile.TarFile method): TarFile Objects. (line 109) * getMessage() (logging.LogRecord method): LogRecord Objects. (line 56) * getMessage() (xml.sax.SAXException method): SAXException Objects. (line 9) * getMessageID() (logging.handlers.NTEventLogHandler method): NTEventLogHandler. (line 60) * getmodule() (in module inspect): Retrieving source code. (line 32) * getmodulename() (in module inspect): Types and members. (line 289) * getmouse() (in module curses): Functions<3>. (line 145) * getmro() (in module inspect): Classes and functions<2>. (line 132) * getmtime() (in module os.path): os path — Common pathname manipulations. (line 177) * getname() (chunk.Chunk method): chunk — Read IFF chunked data. (line 69) * getName() (threading.Thread method): Thread Objects. (line 142) * getNameByQName() (xml.sax.xmlreader.AttributesNS method): The AttributesNS Interface. (line 16) * getnameinfo() (asyncio.loop method): DNS. (line 11) * getnameinfo() (in module socket): Other functions<2>. (line 134) * getnames() (tarfile.TarFile method): TarFile Objects. (line 115) * getNames() (xml.sax.xmlreader.Attributes method): The Attributes Interface. (line 15) * getnchannels() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 51) * getnchannels() (sunau.AU_read method): AU_read Objects. (line 14) * getnchannels() (wave.Wave_read method): Wave_read Objects. (line 15) * getnframes() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 63) * getnframes() (sunau.AU_read method): AU_read Objects. (line 26) * getnframes() (wave.Wave_read method): Wave_read Objects. (line 27) * getnode: uuid — UUID objects according to RFC 4122. (line 178) * getnode() (in module uuid): uuid — UUID objects according to RFC 4122. (line 160) * getopt (module): getopt — C-style parser for command line options. (line 6) * getopt() (distutils.fancy_getopt.FancyGetopt method): distutils fancy_getopt — Wrapper around the standard getopt module. (line 49) * getopt() (in module getopt): getopt — C-style parser for command line options. (line 25) * GetoptError: getopt — C-style parser for command line options. (line 74) * getouterframes() (in module inspect): The interpreter stack. (line 52) * getoutput() (in module subprocess): Legacy Shell Invocation Functions. (line 41) * getpagesize() (in module resource): Resource Usage. (line 101) * getparams() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 79) * getparams() (sunau.AU_read method): AU_read Objects. (line 41) * getparams() (wave.Wave_read method): Wave_read Objects. (line 40) * getparyx() (curses.window method): Window Objects. (line 257) * getpass (module): getpass — Portable password input. (line 6) * getpass() (in module getpass): getpass — Portable password input. (line 12) * GetPassWarning: getpass — Portable password input. (line 29) * getpeercert() (ssl.SSLSocket method): SSL Sockets. (line 139) * getpeername() (socket.socket method): Socket Objects. (line 127) * getpen() (in module turtle): Special Turtle methods. (line 40) * getpgid() (in module os): Process Parameters. (line 227) * getpgrp() (in module os): Process Parameters. (line 235) * getpid() (in module os): Process Parameters. (line 241) * getpos() (html.parser.HTMLParser method): HTMLParser Methods. (line 28) * getppid() (in module os): Process Parameters. (line 245) * getpreferredencoding() (in module locale): locale — Internationalization services. (line 337) * getpriority() (in module os): Process Parameters. (line 256) * getprofile() (in module sys): sys — System-specific parameters and functions. (line 739) * GetProperty() (msilib.SummaryInformation method): Summary Information Objects. (line 6) * getProperty() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 83) * GetPropertyCount() (msilib.SummaryInformation method): Summary Information Objects. (line 17) * getprotobyname() (in module socket): Other functions<2>. (line 152) * getproxies() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 160) * getPublicId() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 10) * getPublicId() (xml.sax.xmlreader.Locator method): Locator Objects. (line 16) * getpwall() (in module pwd): pwd — The password database. (line 65) * getpwnam() (in module pwd): pwd — The password database. (line 61) * getpwuid() (in module pwd): pwd — The password database. (line 57) * getQNameByName() (xml.sax.xmlreader.AttributesNS method): The AttributesNS Interface. (line 20) * getQNames() (xml.sax.xmlreader.AttributesNS method): The AttributesNS Interface. (line 24) * getquota() (imaplib.IMAP4 method): IMAP4 Objects. (line 116) * getquotaroot() (imaplib.IMAP4 method): IMAP4 Objects. (line 121) * getrandbits() (in module random): Bookkeeping functions. (line 41) * getrandom() (in module os): Random numbers<2>. (line 6) * getreader() (in module codecs): codecs — Codec registry and base classes. (line 131) * getrecursionlimit() (in module sys): sys — System-specific parameters and functions. (line 688) * getrefcount() (in module sys): sys — System-specific parameters and functions. (line 682) * getresgid() (in module os): Process Parameters. (line 291) * getresponse() (http.client.HTTPConnection method): HTTPConnection Objects. (line 59) * getresuid() (in module os): Process Parameters. (line 282) * getrlimit() (in module resource): Resource Limits. (line 24) * getroot() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 41) * getrusage() (in module resource): Resource Usage. (line 8) * getsample() (in module audioop): audioop — Manipulate raw audio data. (line 108) * getsampwidth() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 55) * getsampwidth() (sunau.AU_read method): AU_read Objects. (line 18) * getsampwidth() (wave.Wave_read method): Wave_read Objects. (line 19) * getscreen() (in module turtle): Special Turtle methods. (line 51) * getservbyname() (in module socket): Other functions<2>. (line 161) * getservbyport() (in module socket): Other functions<2>. (line 170) * GetSetDescriptorType (in module types): Standard Interpreter Types. (line 198) * getshapes() (in module turtle): Settings and special methods. (line 64) * getsid() (in module os): Process Parameters. (line 432) * getsignal() (in module signal): Module contents<2>. (line 238) * getsitepackages() (in module site): Module contents<3>. (line 56) * getsize() (chunk.Chunk method): chunk — Read IFF chunked data. (line 74) * getsize() (in module os.path): os path — Common pathname manipulations. (line 197) * getsizeof() (in module sys): sys — System-specific parameters and functions. (line 695) * getsockname() (socket.socket method): Socket Objects. (line 135) * getsockopt() (socket.socket method): Socket Objects. (line 141) * getsource() (in module inspect): Retrieving source code. (line 55) * getsourcefile() (in module inspect): Retrieving source code. (line 36) * getsourcelines() (in module inspect): Retrieving source code. (line 42) * getspall() (in module spwd): spwd — The shadow password database. (line 67) * getspnam() (in module spwd): spwd — The shadow password database. (line 59) * getstate() (codecs.IncrementalDecoder method): IncrementalDecoder Objects. (line 44) * getstate() (codecs.IncrementalEncoder method): IncrementalEncoder Objects. (line 42) * getstate() (in module random): Bookkeeping functions. (line 28) * getstatusoutput() (in module subprocess): Legacy Shell Invocation Functions. (line 11) * getstr() (curses.window method): Window Objects. (line 263) * GetString() (msilib.Record method): Record Objects. (line 16) * getSubject() (logging.handlers.SMTPHandler method): SMTPHandler. (line 39) * GetSummaryInformation() (msilib.Database method): Database Objects. (line 16) * getswitchinterval() (in module sys): sys — System-specific parameters and functions. (line 717) * getSystemId() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 18) * getSystemId() (xml.sax.xmlreader.Locator method): Locator Objects. (line 20) * getsyx() (in module curses): Functions<3>. (line 159) * gettarinfo() (tarfile.TarFile method): TarFile Objects. (line 226) * gettempdir() (in module tempfile): tempfile — Generate temporary files and directories. (line 228) * gettempdirb() (in module tempfile): tempfile — Generate temporary files and directories. (line 256) * gettempprefix() (in module tempfile): tempfile — Generate temporary files and directories. (line 262) * gettempprefixb() (in module tempfile): tempfile — Generate temporary files and directories. (line 267) * getTestCaseNames() (unittest.TestLoader method): Loading and running tests. (line 111) * gettext (module): gettext — Multilingual internationalization services. (line 6) * gettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 38) * gettext() (gettext.NullTranslations method): The NullTranslations class. (line 35) * gettext() (in module gettext): GNU gettext API. (line 42) * gettext() (in module locale): Access to message catalogs. (line 6) * gettimeout() (socket.socket method): Socket Objects. (line 162) * gettrace() (in module sys): sys — System-specific parameters and functions. (line 743) * getturtle() (in module turtle): Special Turtle methods. (line 40) * getType() (xml.sax.xmlreader.Attributes method): The Attributes Interface. (line 19) * getuid() (in module os): Process Parameters. (line 300) * geturl() (urllib.parse.urllib.parse.SplitResult method): Structured Parse Results. (line 12) * getuser() (in module getpass): getpass — Portable password input. (line 34) * getuserbase() (in module site): Module contents<3>. (line 62) * getusersitepackages() (in module site): Module contents<3>. (line 70) * getvalue() (io.BytesIO method): Buffered Streams. (line 38) * getvalue() (io.StringIO method): Text I/O<2>. (line 212) * getValue() (xml.sax.xmlreader.Attributes method): The Attributes Interface. (line 24) * getValueByQName() (xml.sax.xmlreader.AttributesNS method): The AttributesNS Interface. (line 12) * getwch() (in module msvcrt): Console I/O. (line 20) * getwche() (in module msvcrt): Console I/O. (line 30) * getweakrefcount() (in module weakref): weakref — Weak references. (line 148) * getweakrefs() (in module weakref): weakref — Weak references. (line 153) * getwelcome() (ftplib.FTP method): FTP Objects. (line 42) * getwelcome() (nntplib.NNTP method): Methods<3>. (line 28) * getwelcome() (poplib.POP3 method): POP3 Objects. (line 20) * getwin() (in module curses): Functions<3>. (line 165) * getwindowsversion() (in module sys): sys — System-specific parameters and functions. (line 754) * getwriter() (in module codecs): codecs — Codec registry and base classes. (line 139) * getxattr() (in module os): Linux extended attributes. (line 10) * getyx() (curses.window method): Window Objects. (line 274) * GET_AITER (opcode): Python Bytecode Instructions. (line 268) * get_all() (email.message.EmailMessage method): email message Representing an email message. (line 254) * get_all() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 362) * get_all() (wsgiref.headers.Headers method): wsgiref headers – WSGI response header tools. (line 51) * get_all_breaks() (bdb.Bdb method): bdb — Debugger framework. (line 332) * get_all_start_methods() (in module multiprocessing): Miscellaneous<3>. (line 70) * GET_ANEXT (opcode): Python Bytecode Instructions. (line 277) * get_app() (wsgiref.simple_server.WSGIServer method): wsgiref simple_server – a simple WSGI HTTP server. (line 66) * get_archive_formats() (in module shutil): Archiving operations. (line 57) * get_args() (in module typing): Classes functions and decorators. (line 642) * get_asyncgen_hooks() (in module sys): sys — System-specific parameters and functions. (line 802) * get_attribute() (in module test.support): test support — Utilities for the Python test suite. (line 799) * GET_AWAITABLE (opcode): Python Bytecode Instructions. (line 260) * get_begidx() (in module readline): Completion. (line 40) * get_blocking() (in module os): File Descriptor Operations. (line 197) * get_body() (email.message.EmailMessage method): email message Representing an email message. (line 518) * get_body_encoding() (email.charset.Charset method): email charset Representing character sets. (line 96) * get_boundary() (email.message.EmailMessage method): email message Representing an email message. (line 403) * get_boundary() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 579) * get_bpbynumber() (bdb.Bdb method): bdb — Debugger framework. (line 309) * get_break() (bdb.Bdb method): bdb — Debugger framework. (line 318) * get_breaks() (bdb.Bdb method): bdb — Debugger framework. (line 322) * get_buffer() (asyncio.BufferedProtocol method): Buffered Streaming Protocols. (line 23) * get_buffer() (xdrlib.Packer method): Packer Objects. (line 8) * get_buffer() (xdrlib.Unpacker method): Unpacker Objects. (line 22) * get_bytes() (mailbox.Mailbox method): Mailbox objects. (line 159) * get_cache_token() (in module abc): abc — Abstract Base Classes. (line 325) * get_ca_certs() (ssl.SSLContext method): SSL Contexts. (line 157) * get_channel_binding() (ssl.SSLSocket method): SSL Sockets. (line 238) * get_charset() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 265) * get_charsets() (email.message.EmailMessage method): email message Representing an email message. (line 431) * get_charsets() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 613) * get_children() (symtable.SymbolTable method): Examining Symbol Tables. (line 62) * get_children() (tkinter.ttk.Treeview method): ttk Treeview. (line 19) * get_child_watcher() (asyncio.AbstractEventLoopPolicy method): Policy Objects. (line 33) * get_child_watcher() (in module asyncio): Process Watchers. (line 25) * get_ciphers() (ssl.SSLContext method): SSL Contexts. (line 171) * get_clock_info() (in module time): Functions<2>. (line 97) * get_close_matches() (in module difflib): difflib — Helpers for computing deltas. (line 204) * get_code() (importlib.abc.InspectLoader method): importlib abc – Abstract base classes related to import. (line 387) * get_code() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 581) * get_code() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 338) * get_code() (importlib.machinery.SourcelessFileLoader method): importlib machinery – Importers and path hooks. (line 281) * get_code() (zipimport.zipimporter method): zipimporter Objects. (line 28) * get_completer() (in module readline): Completion. (line 29) * get_completer_delims() (in module readline): Completion. (line 48) * get_completion_type() (in module readline): Completion. (line 34) * get_config_h_filename() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 41) * get_config_h_filename() (in module sysconfig): Other functions<3>. (line 68) * get_config_var() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 27) * get_config_var() (in module sysconfig): Configuration variables. (line 26) * get_config_vars() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 32) * get_config_vars() (in module sysconfig): Configuration variables. (line 16) * get_content() (email.contentmanager.ContentManager method): email contentmanager Managing MIME Content. (line 19) * get_content() (email.message.EmailMessage method): email message Representing an email message. (line 582) * get_content() (in module email.contentmanager): Content Manager Instances. (line 24) * get_content_charset() (email.message.EmailMessage method): email message Representing an email message. (line 424) * get_content_charset() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 602) * get_content_disposition() (email.message.EmailMessage method): email message Representing an email message. (line 455) * get_content_disposition() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 627) * get_content_maintype() (email.message.EmailMessage method): email message Representing an email message. (line 324) * get_content_maintype() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 432) * get_content_subtype() (email.message.EmailMessage method): email message Representing an email message. (line 330) * get_content_subtype() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 438) * get_content_type() (email.message.EmailMessage method): email message Representing an email message. (line 308) * get_content_type() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 416) * get_context() (in module multiprocessing): Miscellaneous<3>. (line 80) * get_coro() (asyncio.Task method): Task Object. (line 204) * get_coroutine_origin_tracking_depth() (in module sys): sys — System-specific parameters and functions. (line 816) * get_count() (in module gc): gc — Garbage Collector interface. (line 110) * get_current_history_length() (in module readline): History list. (line 14) * get_data() (importlib.abc.FileLoader method): importlib abc – Abstract base classes related to import. (line 503) * get_data() (importlib.abc.ResourceLoader method): importlib abc – Abstract base classes related to import. (line 368) * get_data() (in module pkgutil): pkgutil — Package extension utility. (line 201) * get_data() (zipimport.zipimporter method): zipimporter Objects. (line 33) * get_date() (mailbox.MaildirMessage method): MaildirMessage. (line 92) * get_debug() (asyncio.loop method): Enabling debug mode. (line 6) * get_debug() (in module gc): gc — Garbage Collector interface. (line 55) * get_default() (argparse.ArgumentParser method): Parser defaults. (line 33) * get_default_compiler() (in module distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 36) * get_default_domain() (in module nis): nis — Interface to Sun’s NIS Yellow Pages. (line 48) * get_default_type() (email.message.EmailMessage method): email message Representing an email message. (line 335) * get_default_type() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 443) * get_default_verify_paths() (in module ssl): Certificate handling. (line 101) * get_dialect() (in module csv): Module Contents<3>. (line 85) * get_docstring() (in module ast): ast Helpers. (line 61) * get_doctest() (doctest.DocTestParser method): DocTestParser objects. (line 13) * get_endidx() (in module readline): Completion. (line 40) * get_environ() (wsgiref.simple_server.WSGIRequestHandler method): wsgiref simple_server – a simple WSGI HTTP server. (line 88) * get_errno() (in module ctypes): Utility functions. (line 121) * get_event_loop() (asyncio.AbstractEventLoopPolicy method): Policy Objects. (line 12) * get_event_loop() (in module asyncio): Event Loop. (line 39) * get_event_loop_policy() (in module asyncio): Getting and Setting the Policy. (line 9) * get_examples() (doctest.DocTestParser method): DocTestParser objects. (line 22) * get_exception_handler() (asyncio.loop method): Error Handling API. (line 19) * get_exec_path() (in module os): Process Parameters. (line 153) * get_extra_info() (asyncio.BaseTransport method): Base Transport. (line 20) * get_extra_info() (asyncio.StreamWriter method): StreamWriter. (line 61) * get_field() (string.Formatter method): Custom String Formatting. (line 55) * get_file() (mailbox.Babyl method): Babyl. (line 49) * get_file() (mailbox.Mailbox method): Mailbox objects. (line 175) * get_file() (mailbox.Maildir method): Maildir. (line 119) * get_file() (mailbox.mbox method): mbox. (line 33) * get_file() (mailbox.MH method): MH. (line 93) * get_file() (mailbox.MMDF method): MMDF. (line 29) * get_filename() (email.message.EmailMessage method): email message Representing an email message. (line 393) * get_filename() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 569) * get_filename() (importlib.abc.ExecutionLoader method): importlib abc – Abstract base classes related to import. (line 458) * get_filename() (importlib.abc.FileLoader method): importlib abc – Abstract base classes related to import. (line 499) * get_filename() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 346) * get_filename() (zipimport.zipimporter method): zipimporter Objects. (line 41) * get_file_breaks() (bdb.Bdb method): bdb — Debugger framework. (line 327) * get_flags() (mailbox.MaildirMessage method): MaildirMessage. (line 63) * get_flags() (mailbox.mboxMessage method): mboxMessage. (line 64) * get_flags() (mailbox.MMDFMessage method): MMDFMessage. (line 63) * get_folder() (mailbox.Maildir method): Maildir. (line 65) * get_folder() (mailbox.MH method): MH. (line 36) * get_frees() (symtable.Function method): Examining Symbol Tables. (line 88) * get_freeze_count() (in module gc): gc — Garbage Collector interface. (line 201) * get_from() (mailbox.mboxMessage method): mboxMessage. (line 47) * get_from() (mailbox.MMDFMessage method): MMDFMessage. (line 46) * get_full_url() (urllib.request.Request method): Request Objects. (line 106) * get_globals() (symtable.Function method): Examining Symbol Tables. (line 80) * get_grouped_opcodes() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 166) * get_handle_inheritable() (in module os): Inheritance of File Descriptors. (line 32) * get_header() (urllib.request.Request method): Request Objects. (line 120) * get_history_item() (in module readline): History list. (line 20) * get_history_length() (in module readline): History file. (line 30) * get_id() (symtable.SymbolTable method): Examining Symbol Tables. (line 15) * get_ident() (in module threading): threading — Thread-based parallelism. (line 85) * get_ident() (in module _thread): _thread — Low-level threading API. (line 73) * get_identifiers() (symtable.SymbolTable method): Examining Symbol Tables. (line 48) * get_importer() (in module pkgutil): pkgutil — Package extension utility. (line 92) * get_info() (mailbox.MaildirMessage method): MaildirMessage. (line 102) * get_inheritable() (in module os): Inheritance of File Descriptors. (line 23) * get_inheritable() (socket.socket method): Socket Objects. (line 119) * get_instructions() (in module dis): Analysis functions. (line 110) * get_interpreter() (in module zipapp): Python API. (line 82) * GET_ITER (opcode): Python Bytecode Instructions. (line 113) * get_key() (selectors.BaseSelector method): Classes<3>. (line 145) * get_labels() (mailbox.Babyl method): Babyl. (line 35) * get_labels() (mailbox.BabylMessage method): BabylMessage. (line 47) * get_last_error() (in module ctypes): Utility functions. (line 129) * get_lineno() (symtable.SymbolTable method): Examining Symbol Tables. (line 26) * get_line_buffer() (in module readline): Line buffer. (line 8) * get_loader() (in module pkgutil): pkgutil — Package extension utility. (line 106) * get_locals() (symtable.Function method): Examining Symbol Tables. (line 76) * get_logger() (in module multiprocessing): Logging<2>. (line 11) * get_loop() (asyncio.Future method): Future Object. (line 130) * get_loop() (asyncio.Server method): Server Objects. (line 41) * get_magic() (in module imp): imp — Access the import internals. (line 17) * get_makefile_filename() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 49) * get_makefile_filename() (in module sysconfig): Other functions<3>. (line 72) * get_map() (selectors.BaseSelector method): Classes<3>. (line 153) * get_matching_blocks() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 105) * get_message() (mailbox.Mailbox method): Mailbox objects. (line 152) * get_method() (urllib.request.Request method): Request Objects. (line 69) * get_methods() (symtable.Class method): Examining Symbol Tables. (line 98) * get_mixed_type_key() (in module ipaddress): Other Module Level Functions. (line 56) * get_name() (asyncio.Task method): Task Object. (line 210) * get_name() (symtable.Symbol method): Examining Symbol Tables. (line 108) * get_name() (symtable.SymbolTable method): Examining Symbol Tables. (line 19) * get_namespace() (symtable.Symbol method): Examining Symbol Tables. (line 179) * get_namespaces() (symtable.Symbol method): Examining Symbol Tables. (line 175) * get_native_id() (in module threading): threading — Thread-based parallelism. (line 95) * get_native_id() (in module _thread): _thread — Low-level threading API. (line 81) * get_nonlocals() (symtable.Function method): Examining Symbol Tables. (line 84) * get_nonstandard_attr() (http.cookiejar.Cookie method): Cookie Objects<2>. (line 98) * get_nowait() (asyncio.Queue method): Queue. (line 45) * get_nowait() (multiprocessing.Queue method): Pipes and Queues. (line 155) * get_nowait() (queue.Queue method): Queue Objects. (line 61) * get_nowait() (queue.SimpleQueue method): SimpleQueue Objects. (line 51) * get_objects() (in module gc): gc — Garbage Collector interface. (line 59) * get_object_traceback() (in module tracemalloc): Functions<9>. (line 12) * get_opcodes() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 123) * get_option() (optparse.OptionParser method): Querying and manipulating your option parser. (line 37) * get_option_group() (optparse.OptionParser method): Grouping Options. (line 103) * get_option_order() (distutils.fancy_getopt.FancyGetopt method): distutils fancy_getopt — Wrapper around the standard getopt module. (line 62) * get_origin() (in module typing): Classes functions and decorators. (line 640) * get_original_stdout() (in module test.support): test support — Utilities for the Python test suite. (line 381) * get_osfhandle() (in module msvcrt): File Operations. (line 55) * get_output_charset() (email.charset.Charset method): email charset Representing character sets. (line 111) * get_param() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 478) * get_parameters() (symtable.Function method): Examining Symbol Tables. (line 71) * get_params() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 457) * get_path() (in module sysconfig): Installation paths. (line 67) * get_paths() (in module sysconfig): Installation paths. (line 97) * get_path_names() (in module sysconfig): Installation paths. (line 62) * get_payload() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 180) * get_pid() (asyncio.SubprocessTransport method): Subprocess Transports. (line 6) * get_pipe_transport() (asyncio.SubprocessTransport method): Subprocess Transports. (line 10) * get_platform() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 9) * get_platform() (in module sysconfig): Other functions<3>. (line 11) * get_poly() (in module turtle): Special Turtle methods. (line 17) * get_position() (xdrlib.Unpacker method): Unpacker Objects. (line 12) * get_protocol() (asyncio.BaseTransport method): Base Transport. (line 87) * get_python_inc() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 57) * get_python_lib() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 68) * get_python_version() (in module sysconfig): Other functions<3>. (line 6) * get_recsrc() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 84) * get_referents() (in module gc): gc — Garbage Collector interface. (line 142) * get_referrers() (in module gc): gc — Garbage Collector interface. (line 120) * get_request() (socketserver.BaseServer method): Server Objects<2>. (line 131) * get_returncode() (asyncio.SubprocessTransport method): Subprocess Transports. (line 29) * get_running_loop() (in module asyncio): Event Loop. (line 29) * get_scheme() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 188) * get_scheme_names() (in module sysconfig): Installation paths. (line 57) * get_sequences() (mailbox.MH method): MH. (line 53) * get_sequences() (mailbox.MHMessage method): MHMessage. (line 32) * get_server() (multiprocessing.managers.BaseManager method): Managers. (line 46) * get_server_certificate() (in module ssl): Certificate handling. (line 71) * get_shapepoly() (in module turtle): Appearance. (line 189) * get_socket() (telnetlib.Telnet method): Telnet Objects. (line 93) * get_source() (importlib.abc.InspectLoader method): importlib abc – Abstract base classes related to import. (line 401) * get_source() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 599) * get_source() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 342) * get_source() (importlib.machinery.SourcelessFileLoader method): importlib machinery – Importers and path hooks. (line 286) * get_source() (zipimport.zipimporter method): zipimporter Objects. (line 49) * get_source_segment() (in module ast): ast Helpers. (line 70) * get_special_folder_path() (built-in function): The Postinstallation script. (line 32) * get_stack() (asyncio.Task method): Task Object. (line 168) * get_stack() (bdb.Bdb method): bdb — Debugger framework. (line 339) * get_starttag_text() (html.parser.HTMLParser method): HTMLParser Methods. (line 32) * get_start_method() (in module multiprocessing): Miscellaneous<3>. (line 92) * get_stats() (in module gc): gc — Garbage Collector interface. (line 70) * get_stderr() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 127) * get_stderr() (wsgiref.simple_server.WSGIRequestHandler method): wsgiref simple_server – a simple WSGI HTTP server. (line 98) * get_stdin() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 122) * get_string() (mailbox.Mailbox method): Mailbox objects. (line 167) * get_subdir() (mailbox.MaildirMessage method): MaildirMessage. (line 47) * get_suffixes() (in module imp): imp — Access the import internals. (line 26) * get_symbols() (symtable.SymbolTable method): Examining Symbol Tables. (line 57) * get_tag() (in module imp): imp — Access the import internals. (line 244) * get_task_factory() (asyncio.loop method): Creating Futures and Tasks. (line 42) * get_terminal_size() (in module os): Querying the size of a terminal. (line 8) * get_terminal_size() (in module shutil): Querying the size of the output terminal. (line 6) * get_terminator() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 97) * get_threshold() (in module gc): gc — Garbage Collector interface. (line 115) * get_token() (shlex.shlex method): shlex Objects. (line 8) * get_traceback_limit() (in module tracemalloc): Functions<9>. (line 22) * get_traced_memory() (in module tracemalloc): Functions<9>. (line 32) * get_tracemalloc_memory() (in module tracemalloc): Functions<9>. (line 38) * get_type() (symtable.SymbolTable method): Examining Symbol Tables. (line 10) * get_type_hints() (in module typing): Classes functions and decorators. (line 627) * get_unixfrom() (email.message.EmailMessage method): email message Representing an email message. (line 152) * get_unixfrom() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 162) * get_unpack_formats() (in module shutil): Archiving operations. (line 147) * get_usage() (optparse.OptionParser method): Other methods. (line 22) * get_value() (string.Formatter method): Custom String Formatting. (line 65) * get_version() (optparse.OptionParser method): Printing a version string. (line 34) * get_visible() (mailbox.BabylMessage method): BabylMessage. (line 63) * get_wch() (curses.window method): Window Objects. (line 238) * get_write_buffer_limits() (asyncio.WriteTransport method): Write-only Transports. (line 23) * get_write_buffer_size() (asyncio.WriteTransport method): Write-only Transports. (line 19) * GET_YIELD_FROM_ITER (opcode): Python Bytecode Instructions. (line 117) * gid (tarfile.TarInfo attribute): TarInfo Objects. (line 76) * GIL: Glossary. (line 546) * glob (module): glob — Unix style pathname pattern expansion. (line 6) * glob() (in module glob): glob — Unix style pathname pattern expansion. (line 29) * glob() (msilib.Directory method): Directory Objects. (line 39) * glob() (pathlib.Path method): Methods<2>. (line 86) * global interpreter lock: Thread State and the Global Interpreter Lock. (line 6) * global interpreter lock <1>: Glossary. (line 550) * global; name; binding: The global statement. (line 6) * global; namespace: The standard type hierarchy. (line 304) * globals() (built-in function): Built-in Functions. (line 685) * globs (doctest.DocTest attribute): DocTest Objects. (line 22) * gmtime() (in module time): Functions<2>. (line 131) * gname (tarfile.TarInfo attribute): TarInfo Objects. (line 84) * GNOME: The Catalog constructor. (line 6) * GNUTranslations (class in gettext): The GNUTranslations class. (line 33) * GNU_FORMAT (in module tarfile): tarfile — Read and write tar archive files. (line 226) * gnu_getopt() (in module getopt): getopt — C-style parser for command line options. (line 62) * got (doctest.DocTestFailure attribute): Debugging. (line 204) * goto() (in module turtle): Turtle motion. (line 74) * grammar: Notation. (line 6) * Graphical User Interface: Graphical User Interfaces with Tk. (line 6) * GREATER (in module token): token — Constants used with Python parse trees. (line 110) * GREATEREQUAL (in module token): token — Constants used with Python parse trees. (line 146) * Greenwich Mean Time: time — Time access and conversions. (line 40) * GRND_NONBLOCK (in module os): Random numbers<2>. (line 73) * GRND_RANDOM (in module os): Random numbers<2>. (line 86) * Group (class in email.headerregistry): email headerregistry Custom Header Objects. (line 457) * group() (nntplib.NNTP method): Methods<3>. (line 158) * group() (pathlib.Path method): Methods<2>. (line 109) * group() (re.Match method): Match Objects. (line 29) * groupby() (in module itertools): Itertool functions. (line 298) * groupdict() (re.Match method): Match Objects. (line 121) * groupindex (re.Pattern attribute): Regular Expression Objects. (line 112) * grouping: Indentation. (line 6) * groups (email.headerregistry.AddressHeader attribute): email headerregistry Custom Header Objects. (line 188) * groups (re.Pattern attribute): Regular Expression Objects. (line 108) * groups() (re.Match method): Match Objects. (line 98) * grp (module): grp — The group database. (line 6) * gt() (in module operator): operator — Standard operators as functions. (line 24) * guess_all_extensions() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 51) * guess_all_extensions() (mimetypes.MimeTypes method): MimeTypes Objects. (line 65) * guess_extension() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 63) * guess_extension() (mimetypes.MimeTypes method): MimeTypes Objects. (line 55) * guess_scheme() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 12) * guess_type() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 24) * guess_type() (mimetypes.MimeTypes method): MimeTypes Objects. (line 60) * GUI: Graphical User Interfaces with Tk. (line 6) * gzip (module): gzip — Support for gzip files. (line 6) * gzip command line option; –best: Command line options. (line 14) * gzip command line option; -d: Command line options. (line 18) * gzip command line option; –decompress: Command line options. (line 18) * gzip command line option; –fast: Command line options. (line 10) * gzip command line option; -h: Command line options. (line 22) * gzip command line option; –help: Command line options. (line 22) * gzip command line option; file: Command line options. (line 6) * GzipFile (class in gzip): gzip — Support for gzip files. (line 71) * halfdelay() (in module curses): Functions<3>. (line 195) * Handle (class in asyncio): Callback Handles. (line 6) * handle an exception: Exceptions<2>. (line 6) * handle() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 182) * handle() (logging.Handler method): Handler Objects. (line 81) * handle() (logging.handlers.QueueListener method): QueueListener. (line 63) * handle() (logging.Logger method): Logger Objects. (line 291) * handle() (logging.NullHandler method): NullHandler. (line 20) * handle() (socketserver.BaseRequestHandler method): Request Handler Objects. (line 20) * handle() (wsgiref.simple_server.WSGIRequestHandler method): wsgiref simple_server – a simple WSGI HTTP server. (line 103) * handleError() (logging.Handler method): Handler Objects. (line 88) * handleError() (logging.handlers.SocketHandler method): SocketHandler. (line 33) * Handler (class in logging): Handler Objects. (line 11) * handler() (in module cgitb): cgitb — Traceback manager for CGI scripts. (line 66) * handle_accept() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 143) * handle_accepted() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 153) * handle_charref() (html.parser.HTMLParser method): HTMLParser Methods. (line 93) * handle_close() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 134) * handle_comment() (html.parser.HTMLParser method): HTMLParser Methods. (line 102) * handle_connect() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 128) * handle_data() (html.parser.HTMLParser method): HTMLParser Methods. (line 80) * handle_decl() (html.parser.HTMLParser method): HTMLParser Methods. (line 115) * handle_defect() (email.policy.Policy method): email policy Policy Objects. (line 218) * handle_endtag() (html.parser.HTMLParser method): HTMLParser Methods. (line 64) * handle_entityref() (html.parser.HTMLParser method): HTMLParser Methods. (line 86) * handle_error() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 138) * handle_error() (socketserver.BaseServer method): Server Objects<2>. (line 137) * handle_expect_100() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 195) * handle_expt() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 122) * handle_one_request() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 189) * handle_pi() (html.parser.HTMLParser method): HTMLParser Methods. (line 123) * handle_read() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 107) * handle_request() (socketserver.BaseServer method): Server Objects<2>. (line 21) * handle_request() (xmlrpc.server.CGIXMLRPCRequestHandler method): CGIXMLRPCRequestHandler. (line 50) * handle_startendtag() (html.parser.HTMLParser method): HTMLParser Methods. (line 71) * handle_starttag() (html.parser.HTMLParser method): HTMLParser Methods. (line 45) * handle_timeout() (socketserver.BaseServer method): Server Objects<2>. (line 147) * handle_write() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 112) * harmonic_mean() (in module statistics): Function details. (line 84) * hasattr() (built-in function): Built-in Functions. (line 692) * hasAttribute() (xml.dom.Element method): Element Objects<2>. (line 22) * hasAttributeNS() (xml.dom.Element method): Element Objects<2>. (line 26) * hasAttributes() (xml.dom.Node method): Node Objects. (line 94) * hasChildNodes() (xml.dom.Node method): Node Objects. (line 98) * hascompare (in module dis): Opcode collections. (line 49) * hasconst (in module dis): Opcode collections. (line 21) * hasFeature() (xml.dom.DOMImplementation method): DOMImplementation Objects. (line 11) * hasfree (in module dis): Opcode collections. (line 25) * hash character: Comments. (line 6) * hash() (built-in function): Built-in Functions. (line 699) * hash-based pyc: Glossary. (line 573) * hash.block_size (in module hashlib): Hash algorithms. (line 99) * hash.digest_size (in module hashlib): Hash algorithms. (line 95) * hashable: Dictionary displays. (line 37) * hashable <1>: Glossary. (line 579) * Hashable (class in collections.abc): Collections Abstract Base Classes. (line 108) * Hashable (class in typing): Classes functions and decorators. (line 195) * hasHandlers() (logging.Logger method): Logger Objects. (line 306) * hashfunc (C type): Slot Type typedefs. (line 87) * hashlib (module): hashlib — Secure hashes and message digests. (line 6) * hash_info (in module sys): sys — System-specific parameters and functions. (line 826) * hasjabs (in module dis): Opcode collections. (line 41) * hasjrel (in module dis): Opcode collections. (line 37) * haslocal (in module dis): Opcode collections. (line 45) * hasname (in module dis): Opcode collections. (line 33) * HAS_ALPN (in module ssl): Constants<9>. (line 350) * has_children() (symtable.SymbolTable method): Examining Symbol Tables. (line 39) * has_colors() (in module curses): Functions<3>. (line 171) * has_dualstack_ipv6() (in module socket): Creating sockets. (line 139) * HAS_ECDH (in module ssl): Constants<9>. (line 366) * has_exec() (symtable.SymbolTable method): Examining Symbol Tables. (line 44) * has_extn() (smtplib.SMTP method): SMTP Objects. (line 85) * has_function() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 212) * has_header() (csv.Sniffer method): Module Contents<3>. (line 218) * has_header() (urllib.request.Request method): Request Objects. (line 94) * has_ic() (in module curses): Functions<3>. (line 176) * has_il() (in module curses): Functions<3>. (line 183) * has_ipv6 (in module socket): Constants<8>. (line 213) * has_key (2to3 fixer): Fixers. (line 119) * has_key() (in module curses): Functions<3>. (line 190) * has_location (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 418) * HAS_NEVER_CHECK_COMMON_NAME (in module ssl): Constants<9>. (line 358) * has_nonstandard_attr() (http.cookiejar.Cookie method): Cookie Objects<2>. (line 94) * HAS_NPN (in module ssl): Constants<9>. (line 381) * has_option() (configparser.ConfigParser method): ConfigParser Objects. (line 106) * has_option() (optparse.OptionParser method): Querying and manipulating your option parser. (line 42) * has_section() (configparser.ConfigParser method): ConfigParser Objects. (line 97) * HAS_SNI (in module ssl): Constants<9>. (line 374) * HAS_SSLv2 (in module ssl): Constants<9>. (line 391) * HAS_SSLv3 (in module ssl): Constants<9>. (line 398) * has_ticket (ssl.SSLSession attribute): SSL session. (line 20) * HAS_TLSv1 (in module ssl): Constants<9>. (line 405) * HAS_TLSv1_1 (in module ssl): Constants<9>. (line 412) * HAS_TLSv1_2 (in module ssl): Constants<9>. (line 419) * HAS_TLSv1_3 (in module ssl): Constants<9>. (line 426) * HAVE_ARGUMENT (opcode): Python Bytecode Instructions. (line 901) * HAVE_CONTEXTVAR (in module decimal): Constants<4>. (line 32) * HAVE_DOCSTRINGS (in module test.support): test support — Utilities for the Python test suite. (line 137) * HAVE_THREADS (in module decimal): Constants<4>. (line 25) * HCI_DATA_DIR (in module socket): Constants<8>. (line 226) * HCI_FILTER (in module socket): Constants<8>. (line 226) * HCI_TIME_STAMP (in module socket): Constants<8>. (line 226) * head() (nntplib.NNTP method): Methods<3>. (line 266) * Header (class in email.header): email header Internationalized headers. (line 60) * HeaderError: tarfile — Read and write tar archive files. (line 206) * HeaderParseError: email errors Exception and Defect classes. (line 26) * HeaderParser (class in email.parser): Parser API. (line 106) * HeaderRegistry (class in email.headerregistry): email headerregistry Custom Header Objects. (line 299) * Headers (class in wsgiref.headers): wsgiref headers – WSGI response header tools. (line 9) * headers (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 101) * headers (urllib.error.HTTPError attribute): urllib error — Exception classes raised by urllib request. (line 49) * headers (xmlrpc.client.ProtocolError attribute): ProtocolError Objects. (line 25) * header_encode() (email.charset.Charset method): email charset Representing character sets. (line 118) * header_encode_lines() (email.charset.Charset method): email charset Representing character sets. (line 125) * header_encoding (email.charset.Charset attribute): email charset Representing character sets. (line 59) * header_factory (email.policy.EmailPolicy attribute): email policy Policy Objects. (line 391) * header_fetch_parse() (email.policy.Compat32 method): email policy Policy Objects. (line 578) * header_fetch_parse() (email.policy.EmailPolicy method): email policy Policy Objects. (line 441) * header_fetch_parse() (email.policy.Policy method): email policy Policy Objects. (line 302) * header_items() (urllib.request.Request method): Request Objects. (line 125) * header_max_count() (email.policy.EmailPolicy method): email policy Policy Objects. (line 418) * header_max_count() (email.policy.Policy method): email policy Policy Objects. (line 243) * header_offset (zipfile.ZipInfo attribute): ZipInfo Objects. (line 131) * header_source_parse() (email.policy.Compat32 method): email policy Policy Objects. (line 566) * header_source_parse() (email.policy.EmailPolicy method): email policy Policy Objects. (line 424) * header_source_parse() (email.policy.Policy method): email policy Policy Objects. (line 265) * header_store_parse() (email.policy.Compat32 method): email policy Policy Objects. (line 574) * header_store_parse() (email.policy.EmailPolicy method): email policy Policy Objects. (line 432) * header_store_parse() (email.policy.Policy method): email policy Policy Objects. (line 286) * heading() (in module turtle): Tell Turtle’s state. (line 58) * heading() (tkinter.ttk.Treeview method): ttk Treeview. (line 105) * heapify() (in module heapq): heapq — Heap queue algorithm. (line 56) * heapmin() (in module msvcrt): Other Functions. (line 6) * heappop() (in module heapq): heapq — Heap queue algorithm. (line 42) * heappush() (in module heapq): heapq — Heap queue algorithm. (line 37) * heappushpop() (in module heapq): heapq — Heap queue algorithm. (line 49) * heapq (module): heapq — Heap queue algorithm. (line 6) * heapreplace() (in module heapq): heapq — Heap queue algorithm. (line 60) * helo() (smtplib.SMTP method): SMTP Objects. (line 47) * help (optparse.Option attribute): Option attributes. (line 72) * help (pdb command): Debugger Commands. (line 47) * help() (built-in function): Built-in Functions. (line 712) * help() (nntplib.NNTP method): Methods<3>. (line 214) * help; online: pydoc — Documentation generator and online help system. (line 8) * herror: Exceptions<11>. (line 13) * hex (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 127) * hex() (built-in function): Built-in Functions. (line 734) * hex() (bytearray method): Bytearray Objects. (line 52) * hex() (bytes method): Bytes Objects. (line 78) * hex() (float method): Additional Methods on Float. (line 33) * hex() (memoryview method): Memory Views. (line 184) * hexadecimal literal: Numeric literals. (line 6) * hexadecimal; literals: Numeric Types — int float complex. (line 19) * hexbin() (in module binhex): binhex — Encode and decode binhex4 files. (line 23) * hexdigest() (hashlib.hash method): Hash algorithms. (line 134) * hexdigest() (hashlib.shake method): SHAKE variable length digests. (line 17) * hexdigest() (hmac.HMAC method): hmac — Keyed-Hashing for Message Authentication. (line 69) * hexdigits (in module string): String constants. (line 28) * hexlify() (in module binascii): binascii — Convert between binary and ASCII. (line 131) * hexversion (in module sys): sys — System-specific parameters and functions. (line 867) * hidden() (curses.panel.Panel method): Panel Objects. (line 25) * hide() (curses.panel.Panel method): Panel Objects. (line 30) * hide() (tkinter.ttk.Notebook method): ttk Notebook. (line 23) * hideturtle() (in module turtle): Visibility. (line 6) * hide_cookie2 (http.cookiejar.CookiePolicy attribute): CookiePolicy Objects. (line 76) * HierarchyRequestErr: Exceptions<16>. (line 29) * HIGHEST_PROTOCOL (in module pickle): Module Interface. (line 14) * HIGH_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 66) * HKEY_CLASSES_ROOT (in module winreg): HKEY_* Constants. (line 6) * HKEY_CURRENT_CONFIG (in module winreg): HKEY_* Constants. (line 38) * HKEY_CURRENT_USER (in module winreg): HKEY_* Constants. (line 12) * HKEY_DYN_DATA (in module winreg): HKEY_* Constants. (line 43) * HKEY_LOCAL_MACHINE (in module winreg): HKEY_* Constants. (line 19) * HKEY_PERFORMANCE_DATA (in module winreg): HKEY_* Constants. (line 31) * HKEY_USERS (in module winreg): HKEY_* Constants. (line 25) * hline() (curses.window method): Window Objects. (line 279) * HList (class in tkinter.tix): Hierarchical ListBox. (line 6) * hls_to_rgb() (in module colorsys): colorsys — Conversions between color systems. (line 40) * hmac (module): hmac — Keyed-Hashing for Message Authentication. (line 6) * HOME: os path. (line 15) * HOME <1>: Changes in the Python API. (line 116) * HOME <2>: os path — Common pathname manipulations. (line 140) * HOME <3>: os path — Common pathname manipulations. (line 156) * HOME <4>: distutils util — Miscellaneous other utility functions. (line 77) * HOME <5>: Location and names of config files. (line 50) * HOME <6>: Location and names of config files. (line 67) * home() (in module turtle): Turtle motion. (line 161) * home() (pathlib.Path class method): Methods<2>. (line 25) * HOMEDRIVE: os path — Common pathname manipulations. (line 147) * HOMEDRIVE <1>: Location and names of config files. (line 68) * HOMEPATH: os path — Common pathname manipulations. (line 147) * HOMEPATH <1>: Location and names of config files. (line 68) * hooks; import: Import hooks. (line 6) * hooks; meta: Import hooks. (line 6) * hooks; path: Import hooks. (line 6) * hook_compressed() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 188) * hook_encoded() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 199) * host (urllib.request.Request attribute): Request Objects. (line 25) * hostmask (ipaddress.IPv4Network attribute): Network objects. (line 97) * hostmask (ipaddress.IPv6Network attribute): Network objects. (line 310) * hostname_checks_common_name (ssl.SSLContext attribute): SSL Contexts. (line 630) * hosts (netrc.netrc attribute): netrc Objects. (line 23) * hosts() (ipaddress.IPv4Network method): Network objects. (line 136) * hosts() (ipaddress.IPv6Network method): Network objects. (line 328) * hour (datetime.datetime attribute): datetime Objects. (line 277) * hour (datetime.time attribute): time Objects. (line 50) * HRESULT (class in ctypes): Fundamental data types<2>. (line 208) * hStdError (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 42) * hStdInput (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 27) * hStdOutput (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 35) * hsv_to_rgb() (in module colorsys): colorsys — Conversions between color systems. (line 48) * ht() (in module turtle): Visibility. (line 6) * HTML: html parser — Simple HTML and XHTML parser. (line 8) * HTML <1>: urllib request Restrictions. (line 29) * html (module): html — HyperText Markup Language support. (line 6) * html() (in module cgitb): cgitb — Traceback manager for CGI scripts. (line 57) * html.entities (module): html entities — Definitions of HTML general entities. (line 6) * html.parser (module): html parser — Simple HTML and XHTML parser. (line 6) * html5 (in module html.entities): html entities — Definitions of HTML general entities. (line 14) * HTMLCalendar (class in calendar): calendar — General calendar-related functions. (line 163) * HtmlDiff (class in difflib): difflib — Helpers for computing deltas. (line 81) * HTMLParser (class in html.parser): html parser — Simple HTML and XHTML parser. (line 14) * htonl() (in module socket): Other functions<2>. (line 199) * htons() (in module socket): Other functions<2>. (line 206) * HTTP (in module email.policy): email policy Policy Objects. (line 508) * http (module): http — HTTP modules. (line 6) * http.client (module): http client — HTTP protocol client. (line 6) * http.cookiejar (module): http cookiejar — Cookie handling for HTTP clients. (line 6) * http.cookies (module): http cookies — HTTP state management. (line 6) * http.server (module): http server — HTTP servers. (line 6) * HTTP; http (standard module): http — HTTP modules. (line 8) * HTTP; http.client (standard module): http client — HTTP protocol client. (line 8) * HTTP; protocol: cgi — Common Gateway Interface support. (line 8) * HTTP; protocol <1>: urllib request Restrictions. (line 6) * HTTP; protocol <2>: urllib request Restrictions. (line 29) * HTTP; protocol <3>: http — HTTP modules. (line 8) * HTTP; protocol <4>: http client — HTTP protocol client. (line 8) * HTTP; protocol <5>: http server — HTTP servers. (line 8) * HTTPBasicAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 355) * HTTPConnection (class in http.client): http client — HTTP protocol client. (line 26) * HTTPCookieProcessor (class in urllib.request): urllib request — Extensible library for opening URLs. (line 286) * httpd: http server — HTTP servers. (line 8) * HTTPDefaultErrorHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 277) * HTTPDigestAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 379) * HTTPError: urllib error — Exception classes raised by urllib request. (line 30) * HTTPErrorProcessor (class in urllib.request): urllib request — Extensible library for opening URLs. (line 439) * HTTPException: http client — HTTP protocol client. (line 128) * HTTPHandler (class in logging.handlers): HTTPHandler. (line 10) * HTTPHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 403) * HTTPPasswordMgr (class in urllib.request): urllib request — Extensible library for opening URLs. (line 312) * HTTPPasswordMgrWithDefaultRealm (class in urllib.request): urllib request — Extensible library for opening URLs. (line 316) * HTTPPasswordMgrWithPriorAuth (class in urllib.request): urllib request — Extensible library for opening URLs. (line 322) * HTTPRedirectHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 282) * HTTPResponse (class in http.client): http client — HTTP protocol client. (line 97) * HTTPSConnection (class in http.client): http client — HTTP protocol client. (line 57) * HTTPServer (class in http.server): http server — HTTP servers. (line 25) * HTTPSHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 407) * HTTPStatus (class in http): http — HTTP modules. (line 28) * https_open() (urllib.request.HTTPSHandler method): HTTPSHandler Objects. (line 6) * HTTPS_PORT (in module http.client): http client — HTTP protocol client. (line 201) * https_response() (urllib.request.HTTPErrorProcessor method): HTTPErrorProcessor Objects. (line 18) * http_error_301() (urllib.request.HTTPRedirectHandler method): HTTPRedirectHandler Objects. (line 35) * http_error_302() (urllib.request.HTTPRedirectHandler method): HTTPRedirectHandler Objects. (line 42) * http_error_303() (urllib.request.HTTPRedirectHandler method): HTTPRedirectHandler Objects. (line 48) * http_error_307() (urllib.request.HTTPRedirectHandler method): HTTPRedirectHandler Objects. (line 54) * http_error_401() (urllib.request.HTTPBasicAuthHandler method): HTTPBasicAuthHandler Objects. (line 6) * http_error_401() (urllib.request.HTTPDigestAuthHandler method): HTTPDigestAuthHandler Objects. (line 6) * http_error_407() (urllib.request.ProxyBasicAuthHandler method): ProxyBasicAuthHandler Objects. (line 6) * http_error_407() (urllib.request.ProxyDigestAuthHandler method): ProxyDigestAuthHandler Objects. (line 6) * http_error_auth_reqed() (urllib.request.AbstractBasicAuthHandler method): AbstractBasicAuthHandler Objects. (line 6) * http_error_auth_reqed() (urllib.request.AbstractDigestAuthHandler method): AbstractDigestAuthHandler Objects. (line 6) * http_error_default() (urllib.request.BaseHandler method): BaseHandler Objects. (line 65) * http_open() (urllib.request.HTTPHandler method): HTTPHandler Objects. (line 6) * HTTP_PORT (in module http.client): http client — HTTP protocol client. (line 197) * http_proxy: urllib request — Extensible library for opening URLs. (line 85) * http_proxy <1>: Examples<21>. (line 97) * http_proxy <2>: Basic Authentication. (line 62) * http_response() (urllib.request.HTTPErrorProcessor method): HTTPErrorProcessor Objects. (line 6) * http_version (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 300) * hypot() (in module math): Trigonometric functions. (line 44) * I (in module re): Module Contents. (line 63) * I/O control; buffering: Built-in Functions. (line 1217) * I/O control; buffering <1>: Socket Objects. (line 199) * iadd() (in module operator): In-place Operators. (line 36) * iand() (in module operator): In-place Operators. (line 41) * iconcat() (in module operator): In-place Operators. (line 46) * id (ssl.SSLSession attribute): SSL session. (line 12) * id() (built-in function): Built-in Functions. (line 765) * id() (unittest.TestCase method): Test cases. (line 727) * idcok() (curses.window method): Window Objects. (line 286) * ident (select.kevent attribute): Kevent Objects. (line 8) * ident (threading.Thread attribute): Thread Objects. (line 148) * identchars (cmd.Cmd attribute): Cmd Objects. (line 127) * identifier: Identifiers and keywords. (line 6) * identifier <1>: Identifiers Names. (line 6) * identify() (tkinter.ttk.Notebook method): ttk Notebook. (line 32) * identify() (tkinter.ttk.Treeview method): ttk Treeview. (line 143) * identify() (tkinter.ttk.Widget method): ttk Widget. (line 11) * identify_column() (tkinter.ttk.Treeview method): ttk Treeview. (line 153) * identify_element() (tkinter.ttk.Treeview method): ttk Treeview. (line 182) * identify_region() (tkinter.ttk.Treeview method): ttk Treeview. (line 160) * identify_row() (tkinter.ttk.Treeview method): ttk Treeview. (line 149) * identity of an object: Objects values and types. (line 11) * identity; test: Membership test operations. (line 40) * idioms (2to3 fixer): Fixers. (line 123) * IDLE: IDLE<3>. (line 8) * IDLE <1>: Glossary. (line 599) * IDLESTARTUP: Startup and code execution. (line 7) * IDLE_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 73) * idlok() (curses.window method): Window Objects. (line 294) * if; conditional expression: Conditional expressions. (line 6) * if; in comprehensions: Displays for lists sets and dictionaries. (line 14) * ifloordiv() (in module operator): In-place Operators. (line 52) * if_indextoname() (in module socket): Other functions<2>. (line 401) * if_nameindex() (in module socket): Other functions<2>. (line 358) * if_nametoindex() (in module socket): Other functions<2>. (line 383) * iglob() (in module glob): glob — Unix style pathname pattern expansion. (line 54) * ignorableWhitespace() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 150) * ignore (pdb command): Debugger Commands. (line 111) * IGNORECASE (in module re): Module Contents. (line 63) * ignore_errors() (in module codecs): Error Handlers. (line 140) * IGNORE_EXCEPTION_DETAIL (in module doctest): Option Flags. (line 58) * ignore_patterns() (in module shutil): Directory and files operations. (line 184) * ihave() (nntplib.NNTP method): Methods<3>. (line 291) * IISCGIHandler (class in wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 24) * ilshift() (in module operator): In-place Operators. (line 57) * imag (numbers.Complex attribute): The numeric tower. (line 19) * imaginary literal: Numeric literals. (line 6) * imap() (multiprocessing.pool.Pool method): Process Pools. (line 126) * IMAP4 (class in imaplib): imaplib — IMAP4 protocol client. (line 20) * IMAP4.abort: imaplib — IMAP4 protocol client. (line 49) * IMAP4.error: imaplib — IMAP4 protocol client. (line 44) * IMAP4.readonly: imaplib — IMAP4 protocol client. (line 56) * IMAP4; protocol: imaplib — IMAP4 protocol client. (line 8) * IMAP4_SSL (class in imaplib): imaplib — IMAP4 protocol client. (line 65) * IMAP4_SSL; protocol: imaplib — IMAP4 protocol client. (line 8) * IMAP4_stream (class in imaplib): imaplib — IMAP4 protocol client. (line 99) * IMAP4_stream; protocol: imaplib — IMAP4 protocol client. (line 8) * imaplib (module): imaplib — IMAP4 protocol client. (line 6) * imap_unordered() (multiprocessing.pool.Pool method): Process Pools. (line 141) * imatmul() (in module operator): In-place Operators. (line 72) * imghdr (module): imghdr — Determine the type of an image. (line 6) * immedok() (curses.window method): Window Objects. (line 300) * immutable: Glossary. (line 605) * immutable object: Objects values and types. (line 11) * immutable; data; type: Literals<2>. (line 17) * immutable; object: Literals<2>. (line 17) * immutable; object <1>: Dictionary displays. (line 37) * immutable; sequence; types: Immutable Sequence Types. (line 6) * imod() (in module operator): In-place Operators. (line 62) * imp (module): imp — Access the import internals. (line 6) * ImpImporter (class in pkgutil): pkgutil — Package extension utility. (line 53) * implementation (in module sys): sys — System-specific parameters and functions. (line 890) * ImpLoader (class in pkgutil): pkgutil — Package extension utility. (line 69) * impl_detail() (in module test.support): test support — Utilities for the Python test suite. (line 637) * import (2to3 fixer): Fixers. (line 139) * import hooks: Import hooks. (line 6) * import machinery: The import system. (line 6) * import path: Glossary. (line 613) * importer: Glossary. (line 626) * ImportError: Concrete exceptions. (line 38) * importing: Glossary. (line 621) * importlib (module): importlib — The implementation of import. (line 6) * importlib.abc (module): importlib abc – Abstract base classes related to import. (line 6) * importlib.machinery (module): importlib machinery – Importers and path hooks. (line 6) * importlib.resources (module): importlib resources – Resources. (line 6) * importlib.util (module): importlib util – Utility code for importers. (line 6) * imports (2to3 fixer): Fixers. (line 143) * imports2 (2to3 fixer): Fixers. (line 147) * ImportWarning: Warnings. (line 46) * import_fresh_module() (in module test.support): test support — Utilities for the Python test suite. (line 733) * IMPORT_FROM (opcode): Python Bytecode Instructions. (line 644) * import_module() (in module importlib): Functions<10>. (line 15) * import_module() (in module test.support): test support — Utilities for the Python test suite. (line 718) * IMPORT_NAME (opcode): Python Bytecode Instructions. (line 635) * IMPORT_STAR (opcode): Python Bytecode Instructions. (line 366) * ImproperConnectionState: http client — HTTP protocol client. (line 158) * imul() (in module operator): In-place Operators. (line 67) * inch() (curses.window method): Window Objects. (line 308) * inclusive (tracemalloc.DomainFilter attribute): DomainFilter. (line 12) * inclusive (tracemalloc.Filter attribute): Filter. (line 38) * inclusive; or: Binary bitwise operations. (line 18) * Incomplete: binascii — Convert between binary and ASCII. (line 178) * IncompleteRead: http client — HTTP protocol client. (line 154) * IncompleteReadError: Exceptions<9>. (line 42) * IncrementalDecoder (class in codecs): IncrementalDecoder Objects. (line 11) * incrementaldecoder (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 78) * IncrementalEncoder (class in codecs): IncrementalEncoder Objects. (line 11) * incrementalencoder (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 78) * IncrementalNewlineDecoder (class in io): Text I/O<2>. (line 234) * IncrementalParser (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 20) * increment_lineno() (in module ast): ast Helpers. (line 90) * incr_item(): Exceptions<18>. (line 78) * incr_item() <1>: Exceptions<18>. (line 123) * indent (doctest.Example attribute): Example Objects. (line 47) * INDENT (in module token): token — Constants used with Python parse trees. (line 50) * INDENT token: Indentation. (line 33) * indent() (in module textwrap): textwrap — Text wrapping and filling. (line 91) * indentation: Indentation. (line 6) * IndentationError: Concrete exceptions. (line 258) * index operation: The standard type hierarchy. (line 127) * index() (array.array method): array — Efficient arrays of numeric values. (line 193) * index() (bytearray method): Bytes and Bytearray Operations. (line 99) * index() (bytes method): Bytes and Bytearray Operations. (line 99) * index() (collections.deque method): deque objects. (line 70) * index() (in module operator): operator — Standard operators as functions. (line 93) * index() (multiprocessing.shared_memory.ShareableList method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 268) * index() (sequence method): Common Sequence Operations. (line 21) * index() (str method): String Methods<2>. (line 162) * index() (tkinter.ttk.Notebook method): ttk Notebook. (line 37) * index() (tkinter.ttk.Treeview method): ttk Treeview. (line 188) * IndexError: Concrete exceptions. (line 59) * indexOf() (in module operator): operator — Standard operators as functions. (line 197) * IndexSizeErr: Exceptions<16>. (line 34) * indices() (slice method): The standard type hierarchy. (line 809) * inet_aton() (in module socket): Other functions<2>. (line 219) * inet_ntoa() (in module socket): Other functions<2>. (line 239) * inet_ntop() (in module socket): Other functions<2>. (line 275) * inet_pton() (in module socket): Other functions<2>. (line 256) * Inexact (class in decimal): Signals. (line 42) * inf (in module cmath): Constants<3>. (line 20) * inf (in module math): Constants<2>. (line 24) * infile (shlex.shlex attribute): shlex Objects. (line 140) * Infinity: Built-in Functions. (line 584) * infj (in module cmath): Constants<3>. (line 26) * info() (dis.Bytecode method): Bytecode analysis. (line 53) * info() (gettext.NullTranslations method): The NullTranslations class. (line 78) * info() (in module logging): Module-Level Functions. (line 119) * info() (logging.Logger method): Logger Objects. (line 215) * infolist() (zipfile.ZipFile method): ZipFile Objects. (line 98) * inheritance: Class definitions. (line 6) * ini file: configparser — Configuration file parser. (line 8) * init() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 78) * inited (in module mimetypes): mimetypes — Map filenames to MIME types. (line 117) * initgroups() (in module os): Process Parameters. (line 306) * initialize_options() (distutils.cmd.Command method): Creating a new Distutils command. (line 21) * initial_indent (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 199) * initproc (C type): Slot Type typedefs. (line 45) * initscr() (in module curses): Functions<3>. (line 229) * init_color() (in module curses): Functions<3>. (line 204) * init_database() (in module msilib): msilib — Read and write Microsoft Installer files. (line 60) * init_pair() (in module curses): Functions<3>. (line 216) * inode() (os.DirEntry method): Files and Directories. (line 872) * INPLACE_ADD (opcode): Python Bytecode Instructions. (line 222) * INPLACE_AND (opcode): Python Bytecode Instructions. (line 238) * INPLACE_FLOOR_DIVIDE (opcode): Python Bytecode Instructions. (line 210) * INPLACE_LSHIFT (opcode): Python Bytecode Instructions. (line 230) * INPLACE_MATRIX_MULTIPLY (opcode): Python Bytecode Instructions. (line 204) * INPLACE_MODULO (opcode): Python Bytecode Instructions. (line 218) * INPLACE_MULTIPLY (opcode): Python Bytecode Instructions. (line 200) * INPLACE_OR (opcode): Python Bytecode Instructions. (line 246) * INPLACE_POWER (opcode): Python Bytecode Instructions. (line 196) * INPLACE_RSHIFT (opcode): Python Bytecode Instructions. (line 234) * INPLACE_SUBTRACT (opcode): Python Bytecode Instructions. (line 226) * INPLACE_TRUE_DIVIDE (opcode): Python Bytecode Instructions. (line 214) * INPLACE_XOR (opcode): Python Bytecode Instructions. (line 242) * input: Expression input. (line 6) * input (2to3 fixer): Fixers. (line 153) * input() (built-in function): Built-in Functions. (line 778) * input() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 54) * InputOnly (class in tkinter.tix): Miscellaneous Widgets. (line 6) * InputSource (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 51) * input_charset (email.charset.Charset attribute): email charset Representing character sets. (line 53) * input_codec (email.charset.Charset attribute): email charset Representing character sets. (line 82) * inquiry (C type): Supporting Cyclic Garbage Collection. (line 134) * insch() (curses.window method): Window Objects. (line 314) * insdelln() (curses.window method): Window Objects. (line 321) * insert() (array.array method): array — Efficient arrays of numeric values. (line 198) * insert() (collections.deque method): deque objects. (line 78) * insert() (sequence method): Mutable Sequence Types. (line 16) * insert() (tkinter.ttk.Notebook method): ttk Notebook. (line 42) * insert() (tkinter.ttk.Treeview method): ttk Treeview. (line 193) * insert() (xml.etree.ElementTree.Element method): Element Objects. (line 140) * insertBefore() (xml.dom.Node method): Node Objects. (line 121) * insertln() (curses.window method): Window Objects. (line 329) * insert_text() (in module readline): Line buffer. (line 13) * insnstr() (curses.window method): Window Objects. (line 334) * insort() (in module bisect): bisect — Array bisection algorithm. (line 52) * insort_left() (in module bisect): bisect — Array bisection algorithm. (line 45) * insort_right() (in module bisect): bisect — Array bisection algorithm. (line 52) * inspect (module): inspect — Inspect live objects. (line 6) * inspect command line option; –details: Command Line Interface<3>. (line 13) * InspectLoader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 382) * insstr() (curses.window method): Window Objects. (line 345) * install() (gettext.NullTranslations method): The NullTranslations class. (line 100) * install() (in module gettext): Class-based API. (line 72) * installHandler() (in module unittest): Signal Handling. (line 29) * install_opener() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 116) * install_scripts() (venv.EnvBuilder method): API<2>. (line 125) * instance; call: Calls. (line 147) * instate() (tkinter.ttk.Widget method): ttk Widget. (line 18) * instr() (curses.window method): Window Objects. (line 355) * instream (shlex.shlex attribute): shlex Objects. (line 146) * Instruction (class in dis): Python Bytecode Instructions. (line 10) * Instruction.arg (in module dis): Python Bytecode Instructions. (line 24) * Instruction.argrepr (in module dis): Python Bytecode Instructions. (line 32) * Instruction.argval (in module dis): Python Bytecode Instructions. (line 28) * Instruction.is_jump_target (in module dis): Python Bytecode Instructions. (line 44) * Instruction.offset (in module dis): Python Bytecode Instructions. (line 36) * Instruction.opcode (in module dis): Python Bytecode Instructions. (line 14) * Instruction.opname (in module dis): Python Bytecode Instructions. (line 20) * Instruction.starts_line (in module dis): Python Bytecode Instructions. (line 40) * int (built-in class): Built-in Functions. (line 801) * int (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 131) * Int2AP() (in module imaplib): imaplib — IMAP4 protocol client. (line 113) * integer: The standard type hierarchy. (line 156) * integer literal: Numeric literals. (line 6) * integer; literals: Numeric Types — int float complex. (line 19) * integer; representation: The standard type hierarchy. (line 101) * Integral (class in numbers): The numeric tower. (line 55) * Integrated Development Environment: IDLE<3>. (line 8) * IntegrityError: Exceptions<4>. (line 19) * Intel/DVI ADPCM: audioop — Manipulate raw audio data. (line 17) * IntEnum (class in enum): Module Contents<2>. (line 16) * interact (pdb command): Debugger Commands. (line 275) * interact() (code.InteractiveConsole method): Interactive Console Objects. (line 10) * interact() (in module code): code — Interpreter base classes. (line 32) * interact() (telnetlib.Telnet method): Telnet Objects. (line 113) * interactive: Glossary. (line 631) * interactive mode: Complete Python programs. (line 19) * InteractiveConsole (class in code): code — Interpreter base classes. (line 25) * InteractiveInterpreter (class in code): code — Interpreter base classes. (line 15) * intern (2to3 fixer): Fixers. (line 157) * intern() (in module sys): sys — System-specific parameters and functions. (line 967) * internal type: The standard type hierarchy. (line 645) * Internaldate2tuple() (in module imaplib): imaplib — IMAP4 protocol client. (line 107) * internalSubset (xml.dom.DocumentType attribute): DocumentType Objects. (line 27) * internal_attr (zipfile.ZipInfo attribute): ZipInfo Objects. (line 123) * Internet: Internet Protocols and Support. (line 6) * interpolated string literal: String literal concatenation. (line 24) * interpolation, string (%): printf-style String Formatting. (line 6) * interpolation; bytearray (%): printf-style Bytes Formatting. (line 6) * interpolation; bytes (%): printf-style Bytes Formatting. (line 6) * InterpolationDepthError: Exceptions<5>. (line 42) * InterpolationError: Exceptions<5>. (line 37) * InterpolationMissingOptionError: Exceptions<5>. (line 49) * InterpolationSyntaxError: Exceptions<5>. (line 54) * interpreted: Glossary. (line 640) * interpreter: Top-level components. (line 6) * interpreter lock: Thread State and the Global Interpreter Lock. (line 6) * interpreter prompts: sys — System-specific parameters and functions. (line 1188) * interpreter shutdown: Glossary. (line 650) * interpreter_requires_environment() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 9) * interrupt() (sqlite3.Connection method): Connection Objects. (line 188) * InterruptedError: OS exceptions. (line 71) * interrupt_main() (in module _thread): _thread — Low-level threading API. (line 53) * intersection() (frozenset method): Set Types — set frozenset. (line 102) * intersection_update() (frozenset method): Set Types — set frozenset. (line 175) * IntFlag (class in enum): Module Contents<2>. (line 21) * intro (cmd.Cmd attribute): Cmd Objects. (line 142) * int_info (in module sys): sys — System-specific parameters and functions. (line 933) * InuseAttributeErr: Exceptions<16>. (line 39) * inv() (in module operator): operator — Standard operators as functions. (line 98) * InvalidAccessErr: Exceptions<16>. (line 44) * invalidate_caches() (importlib.abc.MetaPathFinder method): importlib abc – Abstract base classes related to import. (line 86) * invalidate_caches() (importlib.abc.PathEntryFinder method): importlib abc – Abstract base classes related to import. (line 151) * invalidate_caches() (importlib.machinery.FileFinder method): importlib machinery – Importers and path hooks. (line 202) * invalidate_caches() (importlib.machinery.PathFinder class method): importlib machinery – Importers and path hooks. (line 146) * invalidate_caches() (in module importlib): Functions<10>. (line 62) * InvalidCharacterErr: Exceptions<16>. (line 49) * InvalidModificationErr: Exceptions<16>. (line 57) * InvalidOperation (class in decimal): Signals. (line 50) * InvalidStateErr: Exceptions<16>. (line 61) * InvalidStateError: Exception classes. (line 22) * InvalidStateError <1>: Exceptions<9>. (line 28) * InvalidURL: http client — HTTP protocol client. (line 137) * inversion: Unary arithmetic and bitwise operations. (line 15) * invert() (in module operator): operator — Standard operators as functions. (line 98) * invocation: The standard type hierarchy. (line 292) * inv_cdf() (statistics.NormalDist method): NormalDist objects. (line 86) * in_dll() (ctypes._CData method): Data types. (line 63) * in_table_a1() (in module stringprep): stringprep — Internet String Preparation. (line 40) * in_table_b1() (in module stringprep): stringprep — Internet String Preparation. (line 45) * in_table_c11() (in module stringprep): stringprep — Internet String Preparation. (line 60) * in_table_c11_c12() (in module stringprep): stringprep — Internet String Preparation. (line 69) * in_table_c12() (in module stringprep): stringprep — Internet String Preparation. (line 64) * in_table_c21() (in module stringprep): stringprep — Internet String Preparation. (line 74) * in_table_c21_c22() (in module stringprep): stringprep — Internet String Preparation. (line 84) * in_table_c22() (in module stringprep): stringprep — Internet String Preparation. (line 79) * in_table_c3() (in module stringprep): stringprep — Internet String Preparation. (line 89) * in_table_c4() (in module stringprep): stringprep — Internet String Preparation. (line 93) * in_table_c5() (in module stringprep): stringprep — Internet String Preparation. (line 98) * in_table_c6() (in module stringprep): stringprep — Internet String Preparation. (line 102) * in_table_c7() (in module stringprep): stringprep — Internet String Preparation. (line 107) * in_table_c8() (in module stringprep): stringprep — Internet String Preparation. (line 112) * in_table_c9() (in module stringprep): stringprep — Internet String Preparation. (line 117) * in_table_d1() (in module stringprep): stringprep — Internet String Preparation. (line 121) * in_table_d2() (in module stringprep): stringprep — Internet String Preparation. (line 126) * in_transaction (sqlite3.Connection attribute): Connection Objects. (line 18) * IO (class in typing): Classes functions and decorators. (line 471) * io (module): io — Core tools for working with streams. (line 6) * IOBase (class in io): I/O Base Classes. (line 6) * ioctl() (in module fcntl): fcntl — The fcntl and ioctl system calls. (line 54) * ioctl() (socket.socket method): Socket Objects. (line 168) * IOCTL_VM_SOCKETS_GET_LOCAL_CID (in module socket): Constants<8>. (line 194) * IOError: Concrete exceptions. (line 396) * ior() (in module operator): In-place Operators. (line 79) * IO_REPARSE_TAG_APPEXECLINK (in module stat): stat — Interpreting stat results. (line 418) * IO_REPARSE_TAG_MOUNT_POINT (in module stat): stat — Interpreting stat results. (line 418) * IO_REPARSE_TAG_SYMLINK (in module stat): stat — Interpreting stat results. (line 418) * ip (ipaddress.IPv4Interface attribute): Interface objects. (line 19) * ip (ipaddress.IPv6Interface attribute): Interface objects. (line 74) * ipaddress (module): ipaddress — IPv4/IPv6 manipulation library. (line 6) * ipow() (in module operator): In-place Operators. (line 84) * IPv4Address (class in ipaddress): Address objects. (line 13) * IPv4Interface (class in ipaddress): Interface objects. (line 9) * IPv4Network (class in ipaddress): Network objects. (line 13) * ipv4_mapped (ipaddress.IPv6Address attribute): Address objects. (line 195) * IPv6Address (class in ipaddress): Address objects. (line 124) * IPv6Interface (class in ipaddress): Interface objects. (line 64) * IPv6Network (class in ipaddress): Network objects. (line 250) * IPV6_ENABLED (in module test.support): test support — Utilities for the Python test suite. (line 83) * ip_address() (in module ipaddress): Convenience factory functions. (line 9) * ip_interface() (in module ipaddress): Convenience factory functions. (line 37) * ip_network() (in module ipaddress): Convenience factory functions. (line 23) * irshift() (in module operator): In-place Operators. (line 89) * isabs() (in module os.path): os path — Common pathname manipulations. (line 204) * isabstract() (in module inspect): Types and members. (line 419) * IsADirectoryError: OS exceptions. (line 81) * isalnum() (bytearray method): Bytes and Bytearray Operations. (line 441) * isalnum() (bytes method): Bytes and Bytearray Operations. (line 441) * isalnum() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 131) * isalnum() (str method): String Methods<2>. (line 167) * isalpha() (bytearray method): Bytes and Bytearray Operations. (line 459) * isalpha() (bytes method): Bytes and Bytearray Operations. (line 459) * isalpha() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 136) * isalpha() (str method): String Methods<2>. (line 174) * isascii() (bytearray method): Bytes and Bytearray Operations. (line 474) * isascii() (bytes method): Bytes and Bytearray Operations. (line 474) * isascii() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 141) * isascii() (str method): String Methods<2>. (line 184) * isasyncgen() (in module inspect): Types and members. (line 389) * isasyncgenfunction() (in module inspect): Types and members. (line 372) * isatty() (chunk.Chunk method): chunk — Read IFF chunked data. (line 88) * isatty() (in module os): File Descriptor Operations. (line 209) * isatty() (io.IOBase method): I/O Base Classes. (line 74) * isawaitable() (in module inspect): Types and members. (line 353) * isblank() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 145) * isblk() (tarfile.TarInfo method): TarInfo Objects. (line 120) * isbuiltin() (in module inspect): Types and members. (line 409) * ischr() (tarfile.TarInfo method): TarInfo Objects. (line 116) * isclass() (in module inspect): Types and members. (line 309) * isclose() (in module cmath): Classification functions. (line 23) * isclose() (in module math): Number-theoretic and representation functions. (line 104) * iscntrl() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 149) * iscode() (in module inspect): Types and members. (line 405) * iscoroutine() (in module asyncio): Generator-based Coroutines. (line 36) * iscoroutine() (in module inspect): Types and members. (line 346) * iscoroutinefunction() (in module asyncio): Generator-based Coroutines. (line 43) * iscoroutinefunction() (in module inspect): Types and members. (line 335) * isctrl() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 190) * isDaemon() (threading.Thread method): Thread Objects. (line 197) * isdatadescriptor() (in module inspect): Types and members. (line 441) * isdecimal() (str method): String Methods<2>. (line 192) * isdev() (tarfile.TarInfo method): TarInfo Objects. (line 128) * isdigit() (bytearray method): Bytes and Bytearray Operations. (line 482) * isdigit() (bytes method): Bytes and Bytearray Operations. (line 482) * isdigit() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 154) * isdigit() (str method): String Methods<2>. (line 200) * isdir() (in module os.path): os path — Common pathname manipulations. (line 220) * isdir() (tarfile.TarInfo method): TarInfo Objects. (line 104) * isdisjoint() (frozenset method): Set Types — set frozenset. (line 68) * isdown() (in module turtle): Drawing state. (line 86) * iselement() (in module xml.etree.ElementTree): Functions<6>. (line 118) * isenabled() (in module gc): gc — Garbage Collector interface. (line 30) * isEnabledFor() (logging.Logger method): Logger Objects. (line 89) * isendwin() (in module curses): Functions<3>. (line 242) * ISEOF() (in module token): token — Constants used with Python parse trees. (line 34) * isexpr() (in module parser): Queries on ST Objects. (line 12) * isexpr() (parser.ST method): ST Objects. (line 21) * isfifo() (tarfile.TarInfo method): TarInfo Objects. (line 124) * isfile() (in module os.path): os path — Common pathname manipulations. (line 212) * isfile() (tarfile.TarInfo method): TarInfo Objects. (line 96) * isfinite() (in module cmath): Classification functions. (line 6) * isfinite() (in module math): Number-theoretic and representation functions. (line 137) * isfirstline() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 106) * isframe() (in module inspect): Types and members. (line 401) * isfunction() (in module inspect): Types and members. (line 318) * isfuture() (in module asyncio): Future Functions. (line 6) * isgenerator() (in module inspect): Types and members. (line 331) * isgeneratorfunction() (in module inspect): Types and members. (line 323) * isgetsetdescriptor() (in module inspect): Types and members. (line 454) * isgraph() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 159) * isidentifier() (str method): String Methods<2>. (line 210) * isinf() (in module cmath): Classification functions. (line 13) * isinf() (in module math): Number-theoretic and representation functions. (line 144) * isinstance (2to3 fixer): Fixers. (line 161) * isinstance() (built-in function): Built-in Functions. (line 843) * iskeyword() (in module keyword): keyword — Testing for Python keywords. (line 13) * isleap() (in module calendar): calendar — General calendar-related functions. (line 301) * islice() (in module itertools): Itertool functions. (line 355) * islink() (in module os.path): os path — Common pathname manipulations. (line 228) * islnk() (tarfile.TarInfo method): TarInfo Objects. (line 112) * islower() (bytearray method): Bytes and Bytearray Operations. (line 496) * islower() (bytes method): Bytes and Bytearray Operations. (line 496) * islower() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 163) * islower() (str method): String Methods<2>. (line 228) * ismemberdescriptor() (in module inspect): Types and members. (line 463) * ismeta() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 194) * ismethod() (in module inspect): Types and members. (line 314) * ismethoddescriptor() (in module inspect): Types and members. (line 423) * ismodule() (in module inspect): Types and members. (line 305) * ismount() (in module os.path): os path — Common pathname manipulations. (line 236) * isnan() (in module cmath): Classification functions. (line 18) * isnan() (in module math): Number-theoretic and representation functions. (line 149) * ISNONTERMINAL() (in module token): token — Constants used with Python parse trees. (line 30) * isnumeric() (str method): String Methods<2>. (line 234) * isocalendar() (datetime.date method): date Objects. (line 213) * isocalendar() (datetime.datetime method): datetime Objects. (line 594) * isoformat() (datetime.date method): date Objects. (line 236) * isoformat() (datetime.datetime method): datetime Objects. (line 599) * isoformat() (datetime.time method): time Objects. (line 151) * IsolatedAsyncioTestCase (class in unittest): Test cases. (line 809) * isolation_level (sqlite3.Connection attribute): Connection Objects. (line 11) * isoweekday() (datetime.date method): date Objects. (line 206) * isoweekday() (datetime.datetime method): datetime Objects. (line 588) * isprint() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 167) * isprintable() (str method): String Methods<2>. (line 244) * ispunct() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 171) * isqrt() (in module math): Number-theoretic and representation functions. (line 154) * isreadable() (in module pprint): pprint — Data pretty printer. (line 130) * isreadable() (pprint.PrettyPrinter method): PrettyPrinter Objects. (line 24) * isrecursive() (in module pprint): pprint — Data pretty printer. (line 139) * isrecursive() (pprint.PrettyPrinter method): PrettyPrinter Objects. (line 32) * isreg() (tarfile.TarInfo method): TarInfo Objects. (line 100) * isReservedKey() (http.cookies.Morsel method): Morsel Objects. (line 68) * isroutine() (in module inspect): Types and members. (line 414) * isSameNode() (xml.dom.Node method): Node Objects. (line 102) * isspace() (bytearray method): Bytes and Bytearray Operations. (line 513) * isspace() (bytes method): Bytes and Bytearray Operations. (line 513) * isspace() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 176) * isspace() (str method): String Methods<2>. (line 256) * isstdin() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 111) * issubclass() (built-in function): Built-in Functions. (line 854) * issubset() (frozenset method): Set Types — set frozenset. (line 74) * issuite() (in module parser): Queries on ST Objects. (line 22) * issuite() (parser.ST method): ST Objects. (line 25) * issuperset() (frozenset method): Set Types — set frozenset. (line 85) * issym() (tarfile.TarInfo method): TarInfo Objects. (line 108) * ISTERMINAL() (in module token): token — Constants used with Python parse trees. (line 26) * istitle() (bytearray method): Bytes and Bytearray Operations. (line 521) * istitle() (bytes method): Bytes and Bytearray Operations. (line 521) * istitle() (str method): String Methods<2>. (line 266) * istraceback() (in module inspect): Types and members. (line 397) * isub() (in module operator): In-place Operators. (line 94) * isupper() (bytearray method): Bytes and Bytearray Operations. (line 535) * isupper() (bytes method): Bytes and Bytearray Operations. (line 535) * isupper() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 181) * isupper() (str method): String Methods<2>. (line 273) * isvisible() (in module turtle): Visibility. (line 22) * isxdigit() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 185) * is_() (in module operator): operator — Standard operators as functions. (line 63) * is_absolute() (pathlib.PurePath method): Methods and properties. (line 165) * is_active() (asyncio.AbstractChildWatcher method): Process Watchers. (line 68) * is_alive() (multiprocessing.Process method): Process and exceptions. (line 79) * is_alive() (threading.Thread method): Thread Objects. (line 175) * is_android (in module test.support): test support — Utilities for the Python test suite. (line 40) * is_annotated() (symtable.Symbol method): Examining Symbol Tables. (line 142) * is_assigned() (symtable.Symbol method): Examining Symbol Tables. (line 153) * is_attachment() (email.message.EmailMessage method): email message Representing an email message. (line 445) * is_authenticated() (urllib.request.HTTPPasswordMgrWithPriorAuth method): HTTPPasswordMgrWithPriorAuth Objects. (line 30) * is_blocked() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 60) * is_block_device() (pathlib.Path method): Methods<2>. (line 169) * is_canonical() (decimal.Context method): Context objects. (line 292) * is_canonical() (decimal.Decimal method): Decimal objects. (line 278) * IS_CHARACTER_JUNK() (in module difflib): difflib — Helpers for computing deltas. (line 364) * is_char_device() (pathlib.Path method): Methods<2>. (line 178) * is_check_supported() (in module lzma): Miscellaneous<2>. (line 6) * is_closed() (asyncio.loop method): Running and stopping the loop. (line 39) * is_closing() (asyncio.BaseTransport method): Base Transport. (line 16) * is_closing() (asyncio.StreamWriter method): StreamWriter. (line 81) * is_dataclass() (in module dataclasses): Module-level decorators classes and functions. (line 373) * is_declared_global() (symtable.Symbol method): Examining Symbol Tables. (line 133) * is_dir() (os.DirEntry method): Files and Directories. (line 883) * is_dir() (pathlib.Path method): Methods<2>. (line 114) * is_dir() (zipfile.Path method): Path Objects. (line 39) * is_dir() (zipfile.ZipInfo method): ZipInfo Objects. (line 42) * is_enabled() (in module faulthandler): Fault handler state. (line 27) * is_expired() (http.cookiejar.Cookie method): Cookie Objects<2>. (line 109) * is_fifo() (pathlib.Path method): Methods<2>. (line 161) * is_file() (os.DirEntry method): Files and Directories. (line 912) * is_file() (pathlib.Path method): Methods<2>. (line 123) * is_file() (zipfile.Path method): Path Objects. (line 43) * is_finalizing() (in module sys): sys — System-specific parameters and functions. (line 982) * is_finite() (decimal.Context method): Context objects. (line 296) * is_finite() (decimal.Decimal method): Decimal objects. (line 285) * is_free() (symtable.Symbol method): Examining Symbol Tables. (line 148) * is_global (ipaddress.IPv4Address attribute): Address objects. (line 97) * is_global (ipaddress.IPv6Address attribute): Address objects. (line 175) * is_global() (symtable.Symbol method): Examining Symbol Tables. (line 125) * is_hop_by_hop() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 109) * is_imported() (symtable.Symbol method): Examining Symbol Tables. (line 116) * is_infinite() (decimal.Context method): Context objects. (line 300) * is_infinite() (decimal.Decimal method): Decimal objects. (line 290) * is_integer() (float method): Additional Methods on Float. (line 16) * is_jython (in module test.support): test support — Utilities for the Python test suite. (line 36) * is_linetouched() (curses.window method): Window Objects. (line 365) * IS_LINE_JUNK() (in module difflib): difflib — Helpers for computing deltas. (line 357) * is_link_local (ipaddress.IPv4Address attribute): Address objects. (line 119) * is_link_local (ipaddress.IPv4Network attribute): Network objects. (line 80) * is_link_local (ipaddress.IPv6Address attribute): Address objects. (line 183) * is_link_local (ipaddress.IPv6Network attribute): Network objects. (line 304) * is_local() (symtable.Symbol method): Examining Symbol Tables. (line 138) * is_loopback (ipaddress.IPv4Address attribute): Address objects. (line 114) * is_loopback (ipaddress.IPv4Network attribute): Network objects. (line 78) * is_loopback (ipaddress.IPv6Address attribute): Address objects. (line 181) * is_loopback (ipaddress.IPv6Network attribute): Network objects. (line 302) * is_mount() (pathlib.Path method): Methods<2>. (line 132) * is_multicast (ipaddress.IPv4Address attribute): Address objects. (line 86) * is_multicast (ipaddress.IPv4Network attribute): Network objects. (line 70) * is_multicast (ipaddress.IPv6Address attribute): Address objects. (line 171) * is_multicast (ipaddress.IPv6Network attribute): Network objects. (line 294) * is_multipart() (email.message.EmailMessage method): email message Representing an email message. (line 134) * is_multipart() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 145) * is_namespace() (symtable.Symbol method): Examining Symbol Tables. (line 157) * is_nan() (decimal.Context method): Context objects. (line 304) * is_nan() (decimal.Decimal method): Decimal objects. (line 295) * is_nested() (symtable.SymbolTable method): Examining Symbol Tables. (line 35) * is_nonlocal() (symtable.Symbol method): Examining Symbol Tables. (line 129) * is_normal() (decimal.Context method): Context objects. (line 309) * is_normal() (decimal.Decimal method): Decimal objects. (line 300) * is_normalized() (in module unicodedata): unicodedata — Unicode Database. (line 117) * is_not() (in module operator): operator — Standard operators as functions. (line 67) * is_not_allowed() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 74) * is_optimized() (symtable.SymbolTable method): Examining Symbol Tables. (line 31) * is_package() (importlib.abc.InspectLoader method): importlib abc – Abstract base classes related to import. (line 413) * is_package() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 604) * is_package() (importlib.machinery.ExtensionFileLoader method): importlib machinery – Importers and path hooks. (line 333) * is_package() (importlib.machinery.SourceFileLoader method): importlib machinery – Importers and path hooks. (line 232) * is_package() (importlib.machinery.SourcelessFileLoader method): importlib machinery – Importers and path hooks. (line 276) * is_package() (zipimport.zipimporter method): zipimporter Objects. (line 56) * is_parameter() (symtable.Symbol method): Examining Symbol Tables. (line 121) * is_private (ipaddress.IPv4Address attribute): Address objects. (line 91) * is_private (ipaddress.IPv4Network attribute): Network objects. (line 72) * is_private (ipaddress.IPv6Address attribute): Address objects. (line 173) * is_private (ipaddress.IPv6Network attribute): Network objects. (line 296) * is_python_build() (in module sysconfig): Other functions<3>. (line 50) * is_qnan() (decimal.Context method): Context objects. (line 314) * is_qnan() (decimal.Decimal method): Decimal objects. (line 306) * is_reading() (asyncio.ReadTransport method): Read-only Transports. (line 6) * is_referenced() (symtable.Symbol method): Examining Symbol Tables. (line 112) * is_reserved (ipaddress.IPv4Address attribute): Address objects. (line 110) * is_reserved (ipaddress.IPv4Network attribute): Network objects. (line 76) * is_reserved (ipaddress.IPv6Address attribute): Address objects. (line 179) * is_reserved (ipaddress.IPv6Network attribute): Network objects. (line 300) * is_reserved() (pathlib.PurePath method): Methods and properties. (line 184) * is_resource() (importlib.abc.ResourceReader method): importlib abc – Abstract base classes related to import. (line 334) * is_resource() (in module importlib.resources): importlib resources – Resources. (line 120) * is_resource_enabled() (in module test.support): test support — Utilities for the Python test suite. (line 197) * is_running() (asyncio.loop method): Running and stopping the loop. (line 35) * is_safe (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 151) * is_serving() (asyncio.Server method): Server Objects. (line 89) * is_set() (asyncio.Event method): Event. (line 66) * is_set() (threading.Event method): Event Objects. (line 23) * is_signed() (decimal.Context method): Context objects. (line 319) * is_signed() (decimal.Decimal method): Decimal objects. (line 311) * is_site_local (ipaddress.IPv6Address attribute): Address objects. (line 187) * is_site_local (ipaddress.IPv6Network attribute): Network objects. (line 353) * is_snan() (decimal.Context method): Context objects. (line 323) * is_snan() (decimal.Decimal method): Decimal objects. (line 317) * is_socket() (pathlib.Path method): Methods<2>. (line 152) * is_subnormal() (decimal.Context method): Context objects. (line 328) * is_subnormal() (decimal.Decimal method): Decimal objects. (line 322) * is_symlink() (os.DirEntry method): Files and Directories. (line 928) * is_symlink() (pathlib.Path method): Methods<2>. (line 144) * is_tarfile() (in module tarfile): tarfile — Read and write tar archive files. (line 175) * is_term_resized() (in module curses): Functions<3>. (line 237) * is_tracing() (in module tracemalloc): Functions<9>. (line 43) * is_tracked() (in module gc): gc — Garbage Collector interface. (line 157) * is_unspecified (ipaddress.IPv4Address attribute): Address objects. (line 105) * is_unspecified (ipaddress.IPv4Network attribute): Network objects. (line 74) * is_unspecified (ipaddress.IPv6Address attribute): Address objects. (line 177) * is_unspecified (ipaddress.IPv6Network attribute): Network objects. (line 298) * is_wintouched() (curses.window method): Window Objects. (line 372) * is_zero() (decimal.Context method): Context objects. (line 332) * is_zero() (decimal.Decimal method): Decimal objects. (line 327) * is_zipfile() (in module zipfile): zipfile — Work with ZIP archives. (line 71) * item selection: The standard type hierarchy. (line 127) * item() (tkinter.ttk.Treeview method): ttk Treeview. (line 212) * item() (xml.dom.NamedNodeMap method): NamedNodeMap Objects. (line 12) * item() (xml.dom.NodeList method): NodeList Objects. (line 15) * itemgetter() (in module operator): operator — Standard operators as functions. (line 258) * items() (configparser.ConfigParser method): ConfigParser Objects. (line 235) * items() (contextvars.Context method): Manual Context Management. (line 108) * items() (dict method): Mapping Types — dict. (line 168) * items() (email.message.EmailMessage method): email message Representing an email message. (line 240) * items() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 348) * items() (mailbox.Mailbox method): Mailbox objects. (line 129) * items() (types.MappingProxyType method): Standard Interpreter Types. (line 256) * items() (xml.etree.ElementTree.Element method): Element Objects. (line 71) * itemsize (array.array attribute): array — Efficient arrays of numeric values. (line 108) * itemsize (memoryview attribute): Memory Views. (line 428) * ItemsView (class in collections.abc): Collections Abstract Base Classes. (line 187) * ItemsView (class in typing): Classes functions and decorators. (line 290) * iter() (built-in function): Built-in Functions. (line 862) * iter() (xml.etree.ElementTree.Element method): Element Objects. (line 146) * iter() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 45) * iterable: Glossary. (line 665) * Iterable (class in collections.abc): Collections Abstract Base Classes. (line 120) * Iterable (class in typing): Classes functions and decorators. (line 147) * iterable; unpacking: Expression lists. (line 16) * iterator: Glossary. (line 687) * Iterator (class in collections.abc): Collections Abstract Base Classes. (line 137) * Iterator (class in typing): Classes functions and decorators. (line 151) * iterator protocol: Iterator Types. (line 6) * iterdecode() (in module codecs): codecs — Codec registry and base classes. (line 225) * iterdir() (pathlib.Path method): Methods<2>. (line 187) * iterdir() (zipfile.Path method): Path Objects. (line 35) * iterdump() (sqlite3.Connection method): Connection Objects. (line 385) * iterencode() (in module codecs): codecs — Codec registry and base classes. (line 213) * iterencode() (json.JSONEncoder method): Encoders and Decoders. (line 224) * iterfind() (xml.etree.ElementTree.Element method): Element Objects. (line 157) * iterfind() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 52) * iteritems() (mailbox.Mailbox method): Mailbox objects. (line 129) * iterkeys() (mailbox.Mailbox method): Mailbox objects. (line 107) * itermonthdates() (calendar.Calendar method): calendar — General calendar-related functions. (line 45) * itermonthdays() (calendar.Calendar method): calendar — General calendar-related functions. (line 53) * itermonthdays2() (calendar.Calendar method): calendar — General calendar-related functions. (line 61) * itermonthdays3() (calendar.Calendar method): calendar — General calendar-related functions. (line 69) * itermonthdays4() (calendar.Calendar method): calendar — General calendar-related functions. (line 79) * iternextfunc (C type): Slot Type typedefs. (line 99) * iterparse() (in module xml.etree.ElementTree): Functions<6>. (line 124) * itertext() (xml.etree.ElementTree.Element method): Element Objects. (line 166) * itertools (2to3 fixer): Fixers. (line 174) * itertools (module): itertools — Functions creating iterators for efficient looping. (line 6) * itertools_imports (2to3 fixer): Fixers. (line 168) * itervalues() (mailbox.Mailbox method): Mailbox objects. (line 114) * iterweekdays() (calendar.Calendar method): calendar — General calendar-related functions. (line 39) * iter_attachments() (email.message.EmailMessage method): email message Representing an email message. (line 560) * iter_child_nodes() (in module ast): ast Helpers. (line 107) * iter_fields() (in module ast): ast Helpers. (line 102) * iter_importers() (in module pkgutil): pkgutil — Package extension utility. (line 123) * iter_modules() (in module pkgutil): pkgutil — Package extension utility. (line 141) * iter_parts() (email.message.EmailMessage method): email message Representing an email message. (line 576) * iter_unpack() (in module struct): Functions and Exceptions. (line 42) * iter_unpack() (struct.Struct method): Classes<2>. (line 47) * ItimerError: Module contents<2>. (line 211) * ITIMER_PROF (in module signal): Module contents<2>. (line 178) * ITIMER_REAL (in module signal): Module contents<2>. (line 168) * ITIMER_VIRTUAL (in module signal): Module contents<2>. (line 173) * itruediv() (in module operator): In-place Operators. (line 99) * ixor() (in module operator): In-place Operators. (line 104) * j; in numeric literal: Floating point literals. (line 28) * Jansen, Jack: uu — Encode and decode uuencode files. (line 20) * Java; language: The standard type hierarchy. (line 107) * java_ver() (in module platform): Java Platform. (line 6) * join() (asyncio.Queue method): Queue. (line 50) * join() (bytearray method): Bytes and Bytearray Operations. (line 111) * join() (bytes method): Bytes and Bytearray Operations. (line 111) * join() (in module os.path): os path — Common pathname manipulations. (line 254) * join() (in module shlex): shlex — Simple lexical analysis. (line 30) * join() (multiprocessing.JoinableQueue method): Pipes and Queues. (line 242) * join() (multiprocessing.pool.Pool method): Process Pools. (line 180) * join() (multiprocessing.Process method): Process and exceptions. (line 51) * join() (queue.Queue method): Queue Objects. (line 83) * join() (str method): String Methods<2>. (line 279) * join() (threading.Thread method): Thread Objects. (line 110) * JoinableQueue (class in multiprocessing): Pipes and Queues. (line 221) * joinpath() (pathlib.PurePath method): Methods and properties. (line 198) * join_thread() (in module test.support): test support — Utilities for the Python test suite. (line 787) * join_thread() (multiprocessing.Queue method): Pipes and Queues. (line 170) * json (module): json — JSON encoder and decoder. (line 6) * json.tool (module): Command Line Interface<2>. (line 6) * json.tool command line option; -h: Command line options<2>. (line 41) * json.tool command line option; –help: Command line options<2>. (line 41) * json.tool command line option; –json-lines: Command line options<2>. (line 35) * json.tool command line option; –sort-keys: Command line options<2>. (line 29) * json.tool command line option; infile: Command line options<2>. (line 6) * json.tool command line option; outfile: Command line options<2>. (line 24) * JSONDecodeError: Exceptions<13>. (line 6) * JSONDecoder (class in json): Encoders and Decoders. (line 6) * JSONEncoder (class in json): Encoders and Decoders. (line 102) * js_output() (http.cookies.BaseCookie method): Cookie Objects. (line 32) * js_output() (http.cookies.Morsel method): Morsel Objects. (line 79) * jump (pdb command): Debugger Commands. (line 196) * JUMP_ABSOLUTE (opcode): Python Bytecode Instructions. (line 682) * JUMP_FORWARD (opcode): Python Bytecode Instructions. (line 650) * JUMP_IF_FALSE_OR_POP (opcode): Python Bytecode Instructions. (line 675) * JUMP_IF_TRUE_OR_POP (opcode): Python Bytecode Instructions. (line 668) * kbhit() (in module msvcrt): Console I/O. (line 6) * KDEDIR: webbrowser — Convenient Web-browser controller. (line 184) * kevent() (in module select): select — Waiting for I/O completion. (line 103) * key: Dictionary displays. (line 6) * key (http.cookies.Morsel attribute): Morsel Objects. (line 60) * key function: Glossary. (line 709) * key/datum pair: Dictionary displays. (line 6) * KeyboardInterrupt: Concrete exceptions. (line 70) * KeyboardInterrupt (built-in exception): Signal Handling<2>. (line 8) * KeyboardInterrupt (built-in exception) <1>: Signal Handling<2>. (line 20) * KeyError: Concrete exceptions. (line 65) * keylog_filename (ssl.SSLContext attribute): SSL Contexts. (line 529) * keyname() (in module curses): Functions<3>. (line 247) * keypad() (curses.window method): Window Objects. (line 377) * keyrefs() (weakref.WeakKeyDictionary method): weakref — Weak references. (line 174) * keys() (contextvars.Context method): Manual Context Management. (line 100) * keys() (dict method): Mapping Types — dict. (line 173) * keys() (email.message.EmailMessage method): email message Representing an email message. (line 232) * keys() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 340) * keys() (mailbox.Mailbox method): Mailbox objects. (line 107) * keys() (sqlite3.Row method): Row Objects. (line 18) * keys() (types.MappingProxyType method): Standard Interpreter Types. (line 261) * keys() (xml.etree.ElementTree.Element method): Element Objects. (line 76) * KeysView (class in collections.abc): Collections Abstract Base Classes. (line 187) * KeysView (class in typing): Classes functions and decorators. (line 286) * keyword: Keywords. (line 6) * keyword (module): keyword — Testing for Python keywords. (line 6) * keyword argument: Glossary. (line 731) * keyword; as: The import statement. (line 6) * keyword; as <1>: The try statement. (line 6) * keyword; as <2>: The with statement. (line 6) * keyword; async: Coroutine function definition. (line 9) * keyword; await: Calls. (line 149) * keyword; await <1>: Coroutine function definition. (line 9) * keyword; elif: The if statement. (line 6) * keyword; else: The break statement. (line 12) * keyword; else <1>: The if statement. (line 6) * keyword; else <2>: The while statement. (line 6) * keyword; else <3>: The for statement. (line 6) * keyword; else <4>: The try statement. (line 6) * keyword; else <5>: The try statement. (line 79) * keyword; except: The try statement. (line 6) * keyword; finally: The return statement. (line 17) * keyword; finally <1>: The break statement. (line 18) * keyword; finally <2>: The continue statement. (line 6) * keyword; finally <3>: The try statement. (line 6) * keyword; finally <4>: The try statement. (line 85) * keyword; from: Yield expressions. (line 6) * keyword; from <1>: The import statement. (line 6) * keyword; in: The for statement. (line 6) * keyword; yield: Yield expressions. (line 6) * keywords (functools.partial attribute): partial Objects. (line 20) * KEY_ALL_ACCESS (in module winreg): Access Rights. (line 8) * KEY_CREATE_LINK (in module winreg): Access Rights. (line 51) * KEY_CREATE_SUB_KEY (in module winreg): Access Rights. (line 38) * KEY_ENUMERATE_SUB_KEYS (in module winreg): Access Rights. (line 42) * KEY_EXECUTE (in module winreg): Access Rights. (line 26) * KEY_NOTIFY (in module winreg): Access Rights. (line 46) * KEY_QUERY_VALUE (in module winreg): Access Rights. (line 30) * KEY_READ (in module winreg): Access Rights. (line 20) * KEY_SET_VALUE (in module winreg): Access Rights. (line 34) * KEY_WOW64_32KEY (in module winreg): 64-bit Specific. (line 13) * KEY_WOW64_64KEY (in module winreg): 64-bit Specific. (line 8) * KEY_WRITE (in module winreg): Access Rights. (line 15) * kill() (asyncio.asyncio.subprocess.Process method): Interacting with Subprocesses. (line 100) * kill() (asyncio.SubprocessTransport method): Subprocess Transports. (line 35) * kill() (in module os): Process Management. (line 287) * kill() (multiprocessing.Process method): Process and exceptions. (line 166) * kill() (subprocess.Popen method): Popen Objects. (line 89) * killchar() (in module curses): Functions<3>. (line 257) * killpg() (in module os): Process Management. (line 309) * kill_python() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 67) * kind (inspect.Parameter attribute): Introspecting callables with the Signature object. (line 181) * knownfiles (in module mimetypes): mimetypes — Map filenames to MIME types. (line 122) * kqueue() (in module select): select — Waiting for I/O completion. (line 92) * KqueueSelector (class in selectors): Classes<3>. (line 195) * kwargs (inspect.BoundArguments attribute): Introspecting callables with the Signature object. (line 303) * kwlist (in module keyword): keyword — Testing for Python keywords. (line 17) * L (in module re): Module Contents. (line 81) * LabelEntry (class in tkinter.tix): Basic Widgets. (line 31) * LabelFrame (class in tkinter.tix): Basic Widgets. (line 37) * lambda: Glossary. (line 735) * lambda; expression: Lambdas. (line 6) * lambda; expression <1>: Function definitions. (line 104) * lambda; form: Lambdas. (line 6) * LambdaType (in module types): Standard Interpreter Types. (line 19) * LANG: GNU gettext API. (line 21) * LANG <1>: Class-based API. (line 26) * LANG <2>: locale — Internationalization services. (line 49) * LANG <3>: locale — Internationalization services. (line 310) * LANG <4>: locale — Internationalization services. (line 314) * LANGUAGE: GNU gettext API. (line 20) * LANGUAGE <1>: Class-based API. (line 25) * large files: Large File Support. (line 6) * LARGEST (in module test.support): test support — Utilities for the Python test suite. (line 150) * LargeZipFile: zipfile — Work with ZIP archives. (line 37) * last() (nntplib.NNTP method): Methods<3>. (line 237) * lastChild (xml.dom.Node attribute): Node Objects. (line 59) * lastcmd (cmd.Cmd attribute): Cmd Objects. (line 131) * lastgroup (re.Match attribute): Match Objects. (line 186) * lastindex (re.Match attribute): Match Objects. (line 178) * lastResort (in module logging): Module-Level Attributes. (line 6) * lastrowid (sqlite3.Cursor attribute): Cursor Objects. (line 199) * last_accepted (multiprocessing.connection.Listener attribute): Listeners and Clients. (line 103) * last_traceback (in module sys): The standard type hierarchy. (line 757) * last_traceback (in module sys) <1>: sys — System-specific parameters and functions. (line 989) * last_type (in module sys): sys — System-specific parameters and functions. (line 989) * last_value (in module sys): sys — System-specific parameters and functions. (line 989) * layout() (tkinter.ttk.Style method): Ttk Styling. (line 96) * lazycache() (in module linecache): linecache — Random access to text lines. (line 50) * LazyLoader (class in importlib.util): importlib util – Utility code for importers. (line 225) * LBRACE (in module token): token — Constants used with Python parse trees. (line 126) * LBYL: Glossary. (line 742) * lchflags() (in module os): Files and Directories. (line 292) * lchmod() (in module os): Files and Directories. (line 306) * lchmod() (pathlib.Path method): Methods<2>. (line 208) * lchown() (in module os): Files and Directories. (line 321) * LC_ALL: GNU gettext API. (line 20) * LC_ALL <1>: Class-based API. (line 25) * LC_ALL (in module locale): locale — Internationalization services. (line 495) * LC_COLLATE (in module locale): locale — Internationalization services. (line 464) * LC_CTYPE (in module locale): locale — Internationalization services. (line 458) * LC_MESSAGES: GNU gettext API. (line 20) * LC_MESSAGES <1>: Class-based API. (line 26) * LC_MESSAGES (in module locale): locale — Internationalization services. (line 480) * LC_MONETARY (in module locale): locale — Internationalization services. (line 475) * LC_NUMERIC (in module locale): locale — Internationalization services. (line 487) * LC_TIME (in module locale): locale — Internationalization services. (line 470) * LDCXXSHARED: Build and C API Changes<8>. (line 153) * ldexp() (in module math): Number-theoretic and representation functions. (line 167) * LDFLAGS: New Improved and Deprecated Modules<4>. (line 59) * ldgettext() (in module gettext): GNU gettext API. (line 90) * ldngettext() (in module gettext): GNU gettext API. (line 94) * le() (in module operator): operator — Standard operators as functions. (line 24) * leading whitespace: Indentation. (line 6) * leapdays() (in module calendar): calendar — General calendar-related functions. (line 306) * leaveok() (curses.window method): Window Objects. (line 384) * left (filecmp.dircmp attribute): The dircmp class. (line 41) * left() (in module turtle): Turtle motion. (line 57) * LEFTSHIFT (in module token): token — Constants used with Python parse trees. (line 158) * LEFTSHIFTEQUAL (in module token): token — Constants used with Python parse trees. (line 202) * left_list (filecmp.dircmp attribute): The dircmp class. (line 49) * left_only (filecmp.dircmp attribute): The dircmp class. (line 63) * len() (built-in function): Built-in Functions. (line 889) * lenfunc (C type): Slot Type typedefs. (line 103) * length (xml.dom.NamedNodeMap attribute): NamedNodeMap Objects. (line 8) * length (xml.dom.NodeList attribute): NodeList Objects. (line 21) * length_hint() (in module operator): operator — Standard operators as functions. (line 206) * LESS (in module token): token — Constants used with Python parse trees. (line 106) * LESSEQUAL (in module token): token — Constants used with Python parse trees. (line 142) * lexical analysis: Lexical analysis. (line 6) * lexical definitions: Notation. (line 31) * lexists() (in module os.path): os path — Common pathname manipulations. (line 127) * lgamma() (in module math): Special functions. (line 35) * lgettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 93) * lgettext() (gettext.NullTranslations method): The NullTranslations class. (line 63) * lgettext() (in module gettext): GNU gettext API. (line 88) * lib2to3 (module): lib2to3 - 2to3’s library. (line 6) * libc_ver() (in module platform): Unix Platforms. (line 6) * library (in module dbm.ndbm): dbm ndbm — Interface based on ndbm. (line 27) * library (ssl.SSLError attribute): Exceptions<12>. (line 19) * LibraryLoader (class in ctypes): Loading shared libraries. (line 158) * library_dir_option() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 220) * library_filename() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 459) * library_option() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 225) * license (built-in variable): Constants added by the site module. (line 24) * LifoQueue (class in asyncio): LIFO Queue. (line 6) * LifoQueue (class in queue): queue — A synchronized queue class. (line 42) * light-weight processes: _thread — Low-level threading API. (line 6) * LimitOverrunError: Exceptions<9>. (line 59) * limit_denominator() (fractions.Fraction method): fractions — Rational numbers. (line 126) * lin2adpcm() (in module audioop): audioop — Manipulate raw audio data. (line 112) * lin2alaw() (in module audioop): audioop — Manipulate raw audio data. (line 126) * lin2lin() (in module audioop): audioop — Manipulate raw audio data. (line 133) * lin2ulaw() (in module audioop): audioop — Manipulate raw audio data. (line 148) * line continuation: Explicit line joining. (line 6) * line joining: Logical lines. (line 6) * line joining <1>: Explicit line joining. (line 6) * line structure: Line structure. (line 6) * line() (msilib.Dialog method): GUI classes. (line 64) * line-buffered I/O: Built-in Functions. (line 1217) * linecache (module): linecache — Random access to text lines. (line 6) * lineno (ast.AST attribute): Node classes. (line 39) * lineno (doctest.DocTest attribute): DocTest Objects. (line 42) * lineno (doctest.Example attribute): Example Objects. (line 41) * lineno (json.JSONDecodeError attribute): Exceptions<13>. (line 23) * lineno (pyclbr.Class attribute): Class Objects<2>. (line 21) * lineno (pyclbr.Function attribute): Function Objects. (line 21) * lineno (re.error attribute): Module Contents. (line 375) * lineno (shlex.shlex attribute): shlex Objects. (line 169) * lineno (traceback.TracebackException attribute): TracebackException Objects. (line 46) * lineno (tracemalloc.Filter attribute): Filter. (line 48) * lineno (tracemalloc.Frame attribute): Frame. (line 17) * lineno (xml.parsers.expat.ExpatError attribute): ExpatError Exceptions. (line 27) * lineno() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 92) * LINES: curses<2>. (line 6) * LINES <1>: Functions<3>. (line 125) * LINES <2>: Functions<3>. (line 526) * LINES <3>: Functions<3>. (line 550) * LINES <4>: Functions<3>. (line 552) * lines (os.terminal_size attribute): Querying the size of a terminal. (line 34) * linesep (email.policy.Policy attribute): email policy Policy Objects. (line 152) * linesep (in module os): Miscellaneous System Information. (line 127) * lineterminator (csv.Dialect attribute): Dialects and Formatting Parameters. (line 43) * LineTooLong: http client — HTTP protocol client. (line 179) * line_buffering (io.TextIOWrapper attribute): Text I/O<2>. (line 162) * line_num (csv.csvreader attribute): Reader Objects. (line 22) * link() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 349) * link() (in module os): Files and Directories. (line 335) * linkname (tarfile.TarInfo attribute): TarInfo Objects. (line 67) * link_executable() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 401) * link_shared_lib() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 411) * link_shared_object() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 422) * link_to() (pathlib.Path method): Methods<2>. (line 431) * list: Glossary. (line 756) * list (built-in class): Lists<2>. (line 10) * List (class in typing): Classes functions and decorators. (line 255) * list (pdb command): Debugger Commands. (line 206) * list comprehension: Glossary. (line 762) * list() (imaplib.IMAP4 method): IMAP4 Objects. (line 126) * list() (multiprocessing.managers.SyncManager method): Managers. (line 214) * list() (nntplib.NNTP method): Methods<3>. (line 104) * list() (poplib.POP3 method): POP3 Objects. (line 56) * list() (tarfile.TarFile method): TarFile Objects. (line 120) * list; comprehensions: List displays. (line 6) * list; display: List displays. (line 6) * listdir() (in module os): Files and Directories. (line 357) * listen() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 215) * listen() (in module logging.config): Configuration functions. (line 107) * listen() (in module turtle): Using screen events. (line 6) * listen() (socket.socket method): Socket Objects. (line 186) * Listener (class in multiprocessing.connection): Listeners and Clients. (line 50) * listMethods() (xmlrpc.client.ServerProxy.system method): ServerProxy Objects. (line 17) * ListNoteBook (class in tkinter.tix): Manager Widgets. (line 13) * listxattr() (in module os): Linux extended attributes. (line 26) * LIST_APPEND (opcode): Python Bytecode Instructions. (line 322) * list_dialects() (in module csv): Module Contents<3>. (line 91) * list_folders() (mailbox.Maildir method): Maildir. (line 61) * list_folders() (mailbox.MH method): MH. (line 32) * literal: Literals. (line 6) * literal <1>: Literals<2>. (line 6) * Literal (in module typing): Classes functions and decorators. (line 880) * literal_eval() (in module ast): ast Helpers. (line 43) * LittleEndianStructure (class in ctypes): Structured data types. (line 14) * ljust() (bytearray method): Bytes and Bytearray Operations. (line 248) * ljust() (bytes method): Bytes and Bytearray Operations. (line 248) * ljust() (str method): String Methods<2>. (line 287) * LK_LOCK (in module msvcrt): File Operations. (line 19) * LK_NBLCK (in module msvcrt): File Operations. (line 27) * LK_NBRLCK (in module msvcrt): File Operations. (line 27) * LK_RLCK (in module msvcrt): File Operations. (line 19) * LK_UNLCK (in module msvcrt): File Operations. (line 33) * ll (pdb command): Debugger Commands. (line 222) * LMTP (class in smtplib): smtplib — SMTP protocol client. (line 100) * ln() (decimal.Context method): Context objects. (line 336) * ln() (decimal.Decimal method): Decimal objects. (line 332) * LNAME: getpass — Portable password input. (line 38) * lngettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 95) * lngettext() (gettext.NullTranslations method): The NullTranslations class. (line 65) * lngettext() (in module gettext): GNU gettext API. (line 92) * load() (http.cookiejar.FileCookieJar method): CookieJar and FileCookieJar Objects. (line 125) * load() (http.cookies.BaseCookie method): Cookie Objects. (line 40) * load() (in module json): Basic Usage. (line 94) * load() (in module marshal): marshal — Internal Python object serialization. (line 60) * load() (in module pickle): Module Interface. (line 58) * load() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 44) * load() (pickle.Unpickler method): Module Interface. (line 267) * load() (tracemalloc.Snapshot class method): Snapshot. (line 50) * loader: Finders and loaders. (line 6) * loader <1>: Glossary. (line 771) * Loader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 158) * loader (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 374) * LoadError: http cookiejar — Cookie handling for HTTP clients. (line 34) * loader_state (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 398) * LoadKey() (in module winreg): Functions<11>. (line 263) * LoadLibrary() (ctypes.LibraryLoader method): Loading shared libraries. (line 169) * loads() (in module json): Basic Usage. (line 149) * loads() (in module marshal): marshal — Internal Python object serialization. (line 82) * loads() (in module pickle): Module Interface. (line 76) * loads() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 77) * loads() (in module xmlrpc.client): Convenience Functions. (line 19) * loadTestsFromModule() (unittest.TestLoader method): Loading and running tests. (line 41) * loadTestsFromName() (unittest.TestLoader method): Loading and running tests. (line 70) * loadTestsFromNames() (unittest.TestLoader method): Loading and running tests. (line 104) * loadTestsFromTestCase() (unittest.TestLoader method): Loading and running tests. (line 29) * LOAD_ATTR (opcode): Python Bytecode Instructions. (line 626) * LOAD_BUILD_CLASS (opcode): Python Bytecode Instructions. (line 433) * load_cert_chain() (ssl.SSLContext method): SSL Contexts. (line 80) * LOAD_CLASSDEREF (opcode): Python Bytecode Instructions. (line 737) * LOAD_CLOSURE (opcode): Python Bytecode Instructions. (line 724) * LOAD_CONST (opcode): Python Bytecode Instructions. (line 527) * load_default_certs() (ssl.SSLContext method): SSL Contexts. (line 111) * LOAD_DEREF (opcode): Python Bytecode Instructions. (line 731) * load_dh_params() (ssl.SSLContext method): SSL Contexts. (line 355) * load_extension() (sqlite3.Connection method): Connection Objects. (line 291) * LOAD_FAST (opcode): Python Bytecode Instructions. (line 711) * LOAD_GLOBAL (opcode): Python Bytecode Instructions. (line 693) * LOAD_METHOD (opcode): Python Bytecode Instructions. (line 818) * load_module() (importlib.abc.FileLoader method): importlib abc – Abstract base classes related to import. (line 492) * load_module() (importlib.abc.InspectLoader method): importlib abc – Abstract base classes related to import. (line 445) * load_module() (importlib.abc.Loader method): importlib abc – Abstract base classes related to import. (line 195) * load_module() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 592) * load_module() (importlib.machinery.SourceFileLoader method): importlib machinery – Importers and path hooks. (line 247) * load_module() (importlib.machinery.SourcelessFileLoader method): importlib machinery – Importers and path hooks. (line 291) * load_module() (in module imp): imp — Access the import internals. (line 90) * load_module() (zipimport.zipimporter method): zipimporter Objects. (line 62) * LOAD_NAME (opcode): Python Bytecode Instructions. (line 531) * load_package_tests() (in module test.support): test support — Utilities for the Python test suite. (line 910) * load_verify_locations() (ssl.SSLContext method): SSL Contexts. (line 128) * local (class in threading): Thread-Local Data. (line 15) * localcontext() (in module decimal): Context objects. (line 25) * LOCALE (in module re): Module Contents. (line 81) * locale (module): locale — Internationalization services. (line 6) * localeconv() (in module locale): locale — Internationalization services. (line 53) * LocaleHTMLCalendar (class in calendar): calendar — General calendar-related functions. (line 272) * LocaleTextCalendar (class in calendar): calendar — General calendar-related functions. (line 264) * localName (xml.dom.Attr attribute): Attr Objects. (line 13) * localName (xml.dom.Node attribute): Node Objects. (line 64) * locals() (built-in function): Built-in Functions. (line 901) * localtime() (in module email.utils): email utils Miscellaneous utilities. (line 13) * localtime() (in module time): Functions<2>. (line 141) * Locator (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 43) * Lock (class in asyncio): Lock. (line 6) * Lock (class in multiprocessing): Synchronization primitives. (line 46) * Lock (class in threading): Lock Objects. (line 33) * lock() (mailbox.Babyl method): Babyl. (line 59) * lock() (mailbox.Mailbox method): Mailbox objects. (line 249) * lock() (mailbox.Maildir method): Maildir. (line 107) * lock() (mailbox.mbox method): mbox. (line 39) * lock() (mailbox.MH method): MH. (line 84) * lock() (mailbox.MMDF method): MMDF. (line 35) * Lock() (multiprocessing.managers.SyncManager method): Managers. (line 171) * lock, interpreter: Thread State and the Global Interpreter Lock. (line 6) * locked() (asyncio.Condition method): Condition. (line 64) * locked() (asyncio.Lock method): Lock. (line 59) * locked() (asyncio.Semaphore method): Semaphore. (line 51) * locked() (threading.Lock method): Lock Objects. (line 87) * locked() (_thread.lock method): _thread — Low-level threading API. (line 156) * lockf() (in module fcntl): fcntl — The fcntl and ioctl system calls. (line 120) * lockf() (in module os): File Descriptor Operations. (line 214) * locking() (in module msvcrt): File Operations. (line 6) * LockType (in module _thread): _thread — Low-level threading API. (line 28) * lock_held() (in module imp): imp — Access the import internals. (line 257) * log() (in module cmath): Power and logarithmic functions<2>. (line 11) * log() (in module logging): Module-Level Functions. (line 150) * log() (in module math): Power and logarithmic functions. (line 28) * log() (logging.Logger method): Logger Objects. (line 239) * log10() (decimal.Context method): Context objects. (line 340) * log10() (decimal.Decimal method): Decimal objects. (line 338) * log10() (in module cmath): Power and logarithmic functions<2>. (line 18) * log10() (in module math): Power and logarithmic functions. (line 55) * log1p() (in module math): Power and logarithmic functions. (line 36) * log2() (in module math): Power and logarithmic functions. (line 41) * logb() (decimal.Context method): Context objects. (line 344) * logb() (decimal.Decimal method): Decimal objects. (line 344) * Logger (class in logging): Logger Objects. (line 23) * LoggerAdapter (class in logging): LoggerAdapter Objects. (line 11) * logging (module): logging — Logging facility for Python. (line 6) * logging.config (module): logging config — Logging configuration. (line 6) * logging.handlers (module): logging handlers — Logging handlers. (line 6) * logical line: Logical lines. (line 6) * logical_and() (decimal.Context method): Context objects. (line 348) * logical_and() (decimal.Decimal method): Decimal objects. (line 352) * logical_invert() (decimal.Context method): Context objects. (line 353) * logical_invert() (decimal.Decimal method): Decimal objects. (line 358) * logical_or() (decimal.Context method): Context objects. (line 357) * logical_or() (decimal.Decimal method): Decimal objects. (line 363) * logical_xor() (decimal.Context method): Context objects. (line 362) * logical_xor() (decimal.Decimal method): Decimal objects. (line 369) * login() (ftplib.FTP method): FTP Objects. (line 48) * login() (imaplib.IMAP4 method): IMAP4 Objects. (line 132) * login() (nntplib.NNTP method): Methods<3>. (line 48) * login() (smtplib.SMTP method): SMTP Objects. (line 102) * login_cram_md5() (imaplib.IMAP4 method): IMAP4 Objects. (line 137) * LOGNAME: Process Parameters. (line 221) * LOGNAME <1>: getpass — Portable password input. (line 38) * lognormvariate() (in module random): Real-valued distributions. (line 63) * logout() (imaplib.IMAP4 method): IMAP4 Objects. (line 143) * LogRecord (class in logging): LogRecord Objects. (line 11) * log_date_time_string() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 319) * log_error() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 288) * log_exception() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 209) * log_message() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 294) * log_request() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 281) * log_to_stderr() (in module multiprocessing): Logging<2>. (line 24) * long (2to3 fixer): Fixers. (line 181) * longMessage (unittest.TestCase attribute): Test cases. (line 678) * longname() (in module curses): Functions<3>. (line 264) * LONG_MAX: Integer Objects. (line 107) * lookup() (in module codecs): codecs — Codec registry and base classes. (line 47) * lookup() (in module unicodedata): unicodedata — Unicode Database. (line 16) * lookup() (symtable.SymbolTable method): Examining Symbol Tables. (line 52) * lookup() (tkinter.ttk.Style method): Ttk Styling. (line 81) * LookupError: Base classes. (line 54) * lookup_error() (in module codecs): Error Handlers. (line 117) * loop control; target: The break statement. (line 12) * loop() (in module asyncore): asyncore — Asynchronous socket handler. (line 49) * loop; over mutable sequence: The for statement. (line 44) * loop; statement: The break statement. (line 6) * loop; statement <1>: The continue statement. (line 6) * loop; statement <2>: The while statement. (line 6) * loop; statement <3>: The for statement. (line 6) * lower() (bytearray method): Bytes and Bytearray Operations. (line 553) * lower() (bytes method): Bytes and Bytearray Operations. (line 553) * lower() (str method): String Methods<2>. (line 294) * LPAR (in module token): token — Constants used with Python parse trees. (line 54) * lpAttributeList (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 60) * lru_cache() (in module functools): functools — Higher-order functions and operations on callable objects. (line 73) * lseek() (in module os): File Descriptor Operations. (line 240) * lshift() (in module operator): operator — Standard operators as functions. (line 106) * LSQB (in module token): token — Constants used with Python parse trees. (line 62) * lstat() (in module os): Files and Directories. (line 394) * lstat() (pathlib.Path method): Methods<2>. (line 214) * lstrip() (bytearray method): Bytes and Bytearray Operations. (line 260) * lstrip() (bytes method): Bytes and Bytearray Operations. (line 260) * lstrip() (str method): String Methods<2>. (line 302) * lsub() (imaplib.IMAP4 method): IMAP4 Objects. (line 150) * lt() (in module operator): operator — Standard operators as functions. (line 24) * lt() (in module turtle): Turtle motion. (line 57) * LWPCookieJar (class in http.cookiejar): FileCookieJar subclasses and co-operation with web browsers. (line 28) * lzma (module): lzma — Compression using the LZMA algorithm. (line 6) * LZMACompressor (class in lzma): Compressing and decompressing data in memory. (line 6) * LZMADecompressor (class in lzma): Compressing and decompressing data in memory. (line 100) * LZMAError: lzma — Compression using the LZMA algorithm. (line 24) * LZMAFile (class in lzma): Reading and writing compressed files. (line 45) * M (in module re): Module Contents. (line 101) * machine() (in module platform): Cross Platform. (line 36) * macros (netrc.netrc attribute): netrc Objects. (line 29) * mac_ver() (in module platform): Mac OS Platform. (line 6) * madvise() (mmap.mmap method): mmap — Memory-mapped file support. (line 205) * MADV_AUTOSYNC (in module mmap): MADV_* Constants. (line 6) * MADV_CORE (in module mmap): MADV_* Constants. (line 6) * MADV_DODUMP (in module mmap): MADV_* Constants. (line 6) * MADV_DOFORK (in module mmap): MADV_* Constants. (line 6) * MADV_DONTDUMP (in module mmap): MADV_* Constants. (line 6) * MADV_DONTFORK (in module mmap): MADV_* Constants. (line 6) * MADV_DONTNEED (in module mmap): MADV_* Constants. (line 6) * MADV_FREE (in module mmap): MADV_* Constants. (line 6) * MADV_HUGEPAGE (in module mmap): MADV_* Constants. (line 6) * MADV_HWPOISON (in module mmap): MADV_* Constants. (line 6) * MADV_MERGEABLE (in module mmap): MADV_* Constants. (line 6) * MADV_NOCORE (in module mmap): MADV_* Constants. (line 6) * MADV_NOHUGEPAGE (in module mmap): MADV_* Constants. (line 6) * MADV_NORMAL (in module mmap): MADV_* Constants. (line 6) * MADV_NOSYNC (in module mmap): MADV_* Constants. (line 6) * MADV_PROTECT (in module mmap): MADV_* Constants. (line 6) * MADV_RANDOM (in module mmap): MADV_* Constants. (line 6) * MADV_REMOVE (in module mmap): MADV_* Constants. (line 6) * MADV_SEQUENTIAL (in module mmap): MADV_* Constants. (line 6) * MADV_SOFT_OFFLINE (in module mmap): MADV_* Constants. (line 6) * MADV_UNMERGEABLE (in module mmap): MADV_* Constants. (line 6) * MADV_WILLNEED (in module mmap): MADV_* Constants. (line 6) * magic method: Glossary. (line 778) * magic; method: Glossary. (line 782) * MagicMock (class in unittest.mock): Magic Mock. (line 9) * MAGIC_NUMBER (in module importlib.util): importlib util – Utility code for importers. (line 13) * Mailbox (class in mailbox): Mailbox objects. (line 6) * mailbox (module): mailbox — Manipulate mailboxes in various formats. (line 6) * mailcap (module): mailcap — Mailcap file handling. (line 6) * Maildir (class in mailbox): Maildir. (line 6) * MaildirMessage (class in mailbox): MaildirMessage. (line 6) * mailfrom (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 74) * MailmanProxy (class in smtpd): MailmanProxy Objects. (line 6) * main(): Process-wide parameters. (line 9) * main() <1>: Process-wide parameters. (line 36) * main() <2>: Process-wide parameters. (line 217) * main() (in module py_compile): py_compile — Compile Python source files. (line 124) * main() (in module site): Module contents<3>. (line 41) * main() (in module unittest): Loading and running tests. (line 489) * mainloop() (in module turtle): Using screen events. (line 106) * maintype (email.headerregistry.ContentTypeHeader attribute): email headerregistry Custom Header Objects. (line 276) * main_thread() (in module threading): threading — Thread-based parallelism. (line 115) * major (email.headerregistry.MIMEVersionHeader attribute): email headerregistry Custom Header Objects. (line 247) * major() (in module os): Files and Directories. (line 533) * makedev() (in module os): Files and Directories. (line 543) * makedirs() (in module os): Files and Directories. (line 452) * makeelement() (xml.etree.ElementTree.Element method): Element Objects. (line 174) * makefile() (socket method): The standard type hierarchy. (line 630) * makefile() (socket.socket method): Socket Objects. (line 196) * makeLogRecord() (in module logging): Module-Level Functions. (line 236) * makePickle() (logging.handlers.SocketHandler method): SocketHandler. (line 45) * makeRecord() (logging.Logger method): Logger Objects. (line 300) * makeSocket() (logging.handlers.DatagramHandler method): DatagramHandler. (line 28) * makeSocket() (logging.handlers.SocketHandler method): SocketHandler. (line 39) * maketrans() (bytearray static method): Bytes and Bytearray Operations. (line 121) * maketrans() (bytes static method): Bytes and Bytearray Operations. (line 121) * maketrans() (str static method): String Methods<2>. (line 315) * make_alternative() (email.message.EmailMessage method): email message Representing an email message. (line 607) * make_archive() (in module distutils.archive_util): distutils archive_util — Archiving utilities. (line 9) * make_archive() (in module shutil): Archiving operations. (line 14) * make_bad_fd() (in module test.support): test support — Utilities for the Python test suite. (line 681) * make_cookies() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 60) * make_dataclass() (in module dataclasses): Module-level decorators classes and functions. (line 309) * make_file() (difflib.HtmlDiff method): difflib — Helpers for computing deltas. (line 111) * MAKE_FUNCTION (opcode): Python Bytecode Instructions. (line 841) * make_header() (in module email.header): email header Internationalized headers. (line 200) * make_legacy_pyc() (in module test.support): test support — Utilities for the Python test suite. (line 190) * make_mixed() (email.message.EmailMessage method): email message Representing an email message. (line 617) * make_msgid() (in module email.utils): email utils Miscellaneous utilities. (line 29) * make_parser() (in module xml.sax): xml sax — Support for SAX2 parsers. (line 28) * make_pkg() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 87) * make_related() (email.message.EmailMessage method): email message Representing an email message. (line 598) * make_script() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 72) * make_server() (in module wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server. (line 14) * make_table() (difflib.HtmlDiff method): difflib — Helpers for computing deltas. (line 143) * make_tarball() (in module distutils.archive_util): distutils archive_util — Archiving utilities. (line 25) * make_zipfile() (in module distutils.archive_util): distutils archive_util — Archiving utilities. (line 39) * make_zip_pkg() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 94) * make_zip_script() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 79) * malloc(): Overview<3>. (line 33) * mangle_from_ (email.policy.Compat32 attribute): email policy Policy Objects. (line 559) * mangle_from_ (email.policy.Policy attribute): email policy Policy Objects. (line 186) * map (2to3 fixer): Fixers. (line 185) * map() (built-in function): Built-in Functions. (line 913) * map() (concurrent.futures.Executor method): Executor Objects. (line 22) * map() (multiprocessing.pool.Pool method): Process Pools. (line 90) * map() (tkinter.ttk.Style method): Ttk Styling. (line 48) * mapLogRecord() (logging.handlers.HTTPHandler method): HTTPHandler. (line 27) * mapping: Glossary. (line 782) * Mapping (class in collections.abc): Collections Abstract Base Classes. (line 182) * Mapping (class in typing): Classes functions and decorators. (line 217) * mapping() (msilib.Control method): GUI classes. (line 20) * MappingProxyType (class in types): Standard Interpreter Types. (line 217) * MappingView (class in collections.abc): Collections Abstract Base Classes. (line 187) * MappingView (class in typing): Classes functions and decorators. (line 282) * mapPriority() (logging.handlers.SysLogHandler method): SysLogHandler. (line 183) * maps (collections.ChainMap attribute): ChainMap objects. (line 39) * maps() (in module nis): nis — Interface to Sun’s NIS Yellow Pages. (line 41) * MAP_ADD (opcode): Python Bytecode Instructions. (line 327) * map_async() (multiprocessing.pool.Pool method): Process Pools. (line 107) * map_table_b2() (in module stringprep): stringprep — Internet String Preparation. (line 50) * map_table_b3() (in module stringprep): stringprep — Internet String Preparation. (line 55) * map_to_type() (email.headerregistry.HeaderRegistry method): email headerregistry Custom Header Objects. (line 376) * marshal (module): marshal — Internal Python object serialization. (line 6) * marshalling; objects: pickle — Python object serialization. (line 8) * masking; operations: Bitwise Operations on Integer Types. (line 6) * Match (class in typing): Classes functions and decorators. (line 479) * match() (in module nis): nis — Interface to Sun’s NIS Yellow Pages. (line 16) * match() (in module re): Module Contents. (line 152) * match() (pathlib.PurePath method): Methods and properties. (line 212) * match() (re.Pattern method): Regular Expression Objects. (line 37) * Matcher (class in test.support): test support — Utilities for the Python test suite. (line 1086) * matches() (test.support.Matcher method): test support — Utilities for the Python test suite. (line 1088) * match_hostname() (in module ssl): Certificate handling. (line 6) * match_test() (in module test.support): test support — Utilities for the Python test suite. (line 246) * match_value() (test.support.Matcher method): test support — Utilities for the Python test suite. (line 1092) * math (module): math — Mathematical functions. (line 6) * matmul() (in module operator): operator — Standard operators as functions. (line 121) * matrix multiplication: Binary arithmetic operations. (line 23) * max (datetime.date attribute): date Objects. (line 91) * max (datetime.datetime attribute): datetime Objects. (line 252) * max (datetime.time attribute): time Objects. (line 37) * max (datetime.timedelta attribute): timedelta Objects. (line 78) * max() (built-in function): Built-in Functions. (line 923) * max() (decimal.Context method): Context objects. (line 367) * max() (decimal.Decimal method): Decimal objects. (line 375) * max() (in module audioop): audioop — Manipulate raw audio data. (line 155) * maxarray (reprlib.Repr attribute): Repr Objects. (line 15) * maxdeque (reprlib.Repr attribute): Repr Objects. (line 15) * maxdict (reprlib.Repr attribute): Repr Objects. (line 15) * maxDiff (unittest.TestCase attribute): Test cases. (line 695) * maxfrozenset (reprlib.Repr attribute): Repr Objects. (line 15) * MAXIMUM_SUPPORTED (ssl.TLSVersion attribute): Constants<9>. (line 527) * maximum_version (ssl.SSLContext attribute): SSL Contexts. (line 542) * maxlen (collections.deque attribute): deque objects. (line 120) * maxlevel (reprlib.Repr attribute): Repr Objects. (line 10) * maxlist (reprlib.Repr attribute): Repr Objects. (line 15) * maxlong (reprlib.Repr attribute): Repr Objects. (line 27) * maxother (reprlib.Repr attribute): Repr Objects. (line 40) * maxpp() (in module audioop): audioop — Manipulate raw audio data. (line 160) * maxset (reprlib.Repr attribute): Repr Objects. (line 15) * maxsize (asyncio.Queue attribute): Queue. (line 24) * maxsize (in module sys): sys — System-specific parameters and functions. (line 1005) * maxstring (reprlib.Repr attribute): Repr Objects. (line 32) * maxtuple (reprlib.Repr attribute): Repr Objects. (line 15) * maxunicode (in module sys): sys — System-specific parameters and functions. (line 1011) * MAXYEAR (in module datetime): Constants. (line 13) * max_count (email.headerregistry.BaseHeader attribute): email headerregistry Custom Header Objects. (line 60) * MAX_EMAX (in module decimal): Constants<4>. (line 16) * MAX_INTERPOLATION_DEPTH (in module configparser): ConfigParser Objects. (line 321) * max_lines (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 258) * max_line_length (email.policy.Policy attribute): email policy Policy Objects. (line 145) * max_mag() (decimal.Context method): Context objects. (line 371) * max_mag() (decimal.Decimal method): Decimal objects. (line 382) * max_memuse (in module test.support): test support — Utilities for the Python test suite. (line 122) * MAX_PREC (in module decimal): Constants<4>. (line 13) * max_prefixlen (ipaddress.IPv4Address attribute): Address objects. (line 43) * max_prefixlen (ipaddress.IPv4Network attribute): Network objects. (line 65) * max_prefixlen (ipaddress.IPv6Address attribute): Address objects. (line 169) * max_prefixlen (ipaddress.IPv6Network attribute): Network objects. (line 292) * MAX_Py_ssize_t (in module test.support): test support — Utilities for the Python test suite. (line 118) * mbox (class in mailbox): mbox. (line 6) * mboxMessage (class in mailbox): mboxMessage. (line 6) * MB_ICONASTERISK (in module winsound): winsound — Sound-playing interface for Windows. (line 128) * MB_ICONEXCLAMATION (in module winsound): winsound — Sound-playing interface for Windows. (line 132) * MB_ICONHAND (in module winsound): winsound — Sound-playing interface for Windows. (line 136) * MB_ICONQUESTION (in module winsound): winsound — Sound-playing interface for Windows. (line 140) * MB_OK (in module winsound): winsound — Sound-playing interface for Windows. (line 144) * mean (statistics.NormalDist attribute): NormalDist objects. (line 21) * mean() (in module statistics): Function details. (line 10) * median (statistics.NormalDist attribute): NormalDist objects. (line 26) * median() (in module statistics): Function details. (line 121) * median_grouped() (in module statistics): Function details. (line 184) * median_high() (in module statistics): Function details. (line 166) * median_low() (in module statistics): Function details. (line 148) * MemberDescriptorType (in module types): Standard Interpreter Types. (line 206) * membership; test: Membership test operations. (line 37) * memfd_create() (in module os): Files and Directories. (line 1643) * memmove() (in module ctypes): Utility functions. (line 137) * MemoryBIO (class in ssl): Memory BIO Support<2>. (line 134) * MemoryError: Concrete exceptions. (line 78) * MemoryHandler (class in logging.handlers): MemoryHandler. (line 40) * memoryview (built-in class): Memory Views. (line 10) * memset() (in module ctypes): Utility functions. (line 143) * merge() (in module heapq): heapq — Heap queue algorithm. (line 79) * Message (class in email.message): email message Message Representing an email message using the compat32 API. (line 49) * Message (class in mailbox): Message objects. (line 6) * message digest, MD5: hashlib — Secure hashes and message digests. (line 8) * MessageBeep() (in module winsound): winsound — Sound-playing interface for Windows. (line 31) * MessageClass (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 163) * MessageError: email errors Exception and Defect classes. (line 13) * MessageParseError: email errors Exception and Defect classes. (line 19) * messages (in module xml.parsers.expat.errors): Expat error constants. (line 22) * message_factory (email.policy.Policy attribute): email policy Policy Objects. (line 195) * message_from_binary_file() (in module email): Parser API. (line 129) * message_from_bytes() (in module email): Parser API. (line 116) * message_from_file() (in module email): Parser API. (line 152) * message_from_string() (in module email): Parser API. (line 142) * meta hooks: Import hooks. (line 6) * meta path finder: Glossary. (line 791) * meta() (in module curses): Functions<3>. (line 271) * metaclass: Metaclasses. (line 6) * metaclass <1>: Glossary. (line 800) * metaclass (2to3 fixer): Fixers. (line 191) * metaclass hint: Determining the appropriate metaclass. (line 6) * MetaPathFinder (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 45) * metavar (optparse.Option attribute): Option attributes. (line 80) * MetavarTypeHelpFormatter (class in argparse): formatter_class. (line 10) * meta_path (in module sys): sys — System-specific parameters and functions. (line 1021) * Meter (class in tkinter.tix): Basic Widgets. (line 44) * method: Glossary. (line 815) * method (urllib.request.Request attribute): Request Objects. (line 52) * method resolution order: Glossary. (line 823) * method; call: Calls. (line 132) * methodattrs (2to3 fixer): Fixers. (line 196) * methodcaller() (in module operator): operator — Standard operators as functions. (line 310) * MethodDescriptorType (in module types): Standard Interpreter Types. (line 103) * methodHelp() (xmlrpc.client.ServerProxy.system method): ServerProxy Objects. (line 43) * methods (in module crypt): Module Attributes. (line 8) * methods (pyclbr.Class attribute): Class Objects<2>. (line 46) * methodSignature() (xmlrpc.client.ServerProxy.system method): ServerProxy Objects. (line 22) * MethodType (in module types): Standard Interpreter Types. (line 77) * MethodType (in module types) <1>: Function Objects<3>. (line 14) * MethodType (in module types) <2>: Method Objects<2>. (line 12) * MethodWrapperType (in module types): Standard Interpreter Types. (line 96) * METHOD_BLOWFISH (in module crypt): Hashing Methods. (line 22) * method_calls (unittest.mock.Mock attribute): The Mock Class. (line 482) * METHOD_CRYPT (in module crypt): Hashing Methods. (line 34) * METHOD_MD5 (in module crypt): Hashing Methods. (line 29) * METHOD_SHA256 (in module crypt): Hashing Methods. (line 17) * METHOD_SHA512 (in module crypt): Hashing Methods. (line 11) * METH_CLASS (built-in variable): Common Object Structures. (line 225) * METH_COEXIST (built-in variable): Common Object Structures. (line 242) * METH_FASTCALL (built-in variable): Common Object Structures. (line 176) * METH_NOARGS (built-in variable): Common Object Structures. (line 203) * METH_O (built-in variable): Common Object Structures. (line 212) * METH_STATIC (built-in variable): Common Object Structures. (line 232) * METH_VARARGS (built-in variable): Common Object Structures. (line 157) * MFD_ALLOW_SEALING (in module os): Files and Directories. (line 1662) * MFD_CLOEXEC (in module os): Files and Directories. (line 1662) * MFD_HUGETLB (in module os): Files and Directories. (line 1662) * MFD_HUGE_16GB (in module os): Files and Directories. (line 1662) * MFD_HUGE_16MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_1GB (in module os): Files and Directories. (line 1662) * MFD_HUGE_1MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_256MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_2GB (in module os): Files and Directories. (line 1662) * MFD_HUGE_2MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_32MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_512KB (in module os): Files and Directories. (line 1662) * MFD_HUGE_512MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_64KB (in module os): Files and Directories. (line 1662) * MFD_HUGE_8MB (in module os): Files and Directories. (line 1662) * MFD_HUGE_MASK (in module os): Files and Directories. (line 1662) * MFD_HUGE_SHIFT (in module os): Files and Directories. (line 1662) * MH (class in mailbox): MH. (line 6) * MHMessage (class in mailbox): MHMessage. (line 6) * microsecond (datetime.datetime attribute): datetime Objects. (line 289) * microsecond (datetime.time attribute): time Objects. (line 62) * MIME; base64 encoding: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 8) * MIME; content type: mimetypes — Map filenames to MIME types. (line 8) * MIME; headers: mimetypes — Map filenames to MIME types. (line 26) * MIME; headers <1>: cgi — Common Gateway Interface support. (line 8) * MIME; quoted-printable encoding: quopri — Encode and decode MIME quoted-printable data. (line 8) * MIMEApplication (class in email.mime.application): email mime Creating email and MIME objects from scratch. (line 95) * MIMEAudio (class in email.mime.audio): email mime Creating email and MIME objects from scratch. (line 125) * MIMEBase (class in email.mime.base): email mime Creating email and MIME objects from scratch. (line 30) * MIMEImage (class in email.mime.image): email mime Creating email and MIME objects from scratch. (line 158) * MIMEMessage (class in email.mime.message): email mime Creating email and MIME objects from scratch. (line 191) * MIMEMultipart (class in email.mime.multipart): email mime Creating email and MIME objects from scratch. (line 66) * MIMENonMultipart (class in email.mime.nonmultipart): email mime Creating email and MIME objects from scratch. (line 55) * MIMEPart (class in email.message): email message Representing an email message. (line 718) * MIMEText (class in email.mime.text): email mime Creating email and MIME objects from scratch. (line 209) * MimeTypes (class in mimetypes): MimeTypes Objects. (line 10) * mimetypes (module): mimetypes — Map filenames to MIME types. (line 6) * MIMEVersionHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 234) * min (datetime.date attribute): date Objects. (line 87) * min (datetime.datetime attribute): datetime Objects. (line 247) * min (datetime.time attribute): time Objects. (line 33) * min (datetime.timedelta attribute): timedelta Objects. (line 73) * min() (built-in function): Built-in Functions. (line 955) * min() (decimal.Context method): Context objects. (line 375) * min() (decimal.Decimal method): Decimal objects. (line 387) * MINEQUAL (in module token): token — Constants used with Python parse trees. (line 174) * MINIMUM_SUPPORTED (ssl.TLSVersion attribute): Constants<9>. (line 525) * minimum_version (ssl.SSLContext attribute): SSL Contexts. (line 563) * minmax() (in module audioop): audioop — Manipulate raw audio data. (line 164) * minor (email.headerregistry.MIMEVersionHeader attribute): email headerregistry Custom Header Objects. (line 251) * minor() (in module os): Files and Directories. (line 538) * minus: Unary arithmetic and bitwise operations. (line 10) * MINUS (in module token): token — Constants used with Python parse trees. (line 86) * minus() (decimal.Context method): Context objects. (line 383) * minute (datetime.datetime attribute): datetime Objects. (line 281) * minute (datetime.time attribute): time Objects. (line 54) * MINYEAR (in module datetime): Constants. (line 8) * MIN_EMIN (in module decimal): Constants<4>. (line 19) * MIN_ETINY (in module decimal): Constants<4>. (line 22) * min_mag() (decimal.Context method): Context objects. (line 379) * min_mag() (decimal.Decimal method): Decimal objects. (line 394) * mirrored() (in module unicodedata): unicodedata — Unicode Database. (line 69) * misc_header (cmd.Cmd attribute): Cmd Objects. (line 152) * MISSING (contextvars.contextvars.Token.Token attribute): Context Variables. (line 94) * MissingSectionHeaderError: Exceptions<5>. (line 60) * missing_compiler_executable() (in module test.support): test support — Utilities for the Python test suite. (line 961) * MISSING_C_DOCSTRINGS (in module test.support): test support — Utilities for the Python test suite. (line 132) * MIXERDEV: ossaudiodev — Access to OSS-compatible audio devices. (line 74) * mkd() (ftplib.FTP method): FTP Objects. (line 217) * mkdir() (in module os): Files and Directories. (line 427) * mkdir() (pathlib.Path method): Methods<2>. (line 220) * mkdtemp() (in module tempfile): tempfile — Generate temporary files and directories. (line 200) * mkfifo() (in module os): Files and Directories. (line 492) * mknod() (in module os): Files and Directories. (line 513) * mkpath() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 493) * mkpath() (in module distutils.dir_util): distutils dir_util — Directory tree operations. (line 9) * mksalt() (in module crypt): Module Functions<2>. (line 39) * mkstemp() (in module tempfile): tempfile — Generate temporary files and directories. (line 142) * mktemp() (in module tempfile): Deprecated functions and variables. (line 15) * mktime() (in module time): Functions<2>. (line 148) * mktime_tz() (in module email.utils): email utils Miscellaneous utilities. (line 133) * mlsd() (ftplib.FTP method): FTP Objects. (line 165) * mmap (class in mmap): mmap — Memory-mapped file support. (line 48) * mmap (module): mmap — Memory-mapped file support. (line 6) * MMDF (class in mailbox): MMDF. (line 6) * MMDFMessage (class in mailbox): MMDFMessage. (line 6) * Mock (class in unittest.mock): The Mock Class. (line 24) * mock_add_spec() (unittest.mock.Mock method): The Mock Class. (line 226) * mock_calls (unittest.mock.Mock attribute): The Mock Class. (line 500) * mock_open() (in module unittest.mock): mock_open. (line 6) * mod() (in module operator): operator — Standard operators as functions. (line 111) * mode (io.FileIO attribute): Raw File I/O. (line 57) * mode (ossaudiodev.oss_audio_device attribute): Audio Device Objects. (line 238) * mode (statistics.NormalDist attribute): NormalDist objects. (line 31) * mode (tarfile.TarInfo attribute): TarInfo Objects. (line 55) * mode() (in module statistics): Function details. (line 229) * mode() (in module turtle): Settings and special methods. (line 6) * modf() (in module math): Number-theoretic and representation functions. (line 172) * modified() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 45) * Modify() (msilib.View method): View Objects. (line 23) * modify() (select.devpoll method): /dev/poll Polling Objects. (line 49) * modify() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 85) * modify() (select.poll method): Polling Objects. (line 60) * modify() (selectors.BaseSelector method): Classes<3>. (line 94) * module: Glossary. (line 830) * module (pyclbr.Class attribute): Class Objects<2>. (line 13) * module (pyclbr.Function attribute): Function Objects. (line 13) * module spec: Finders and loaders. (line 6) * module spec <1>: Glossary. (line 839) * module; array: The standard type hierarchy. (line 213) * module; array <1>: Binary Sequence Types — bytes bytearray memoryview. (line 6) * module; base64: binascii — Convert between binary and ASCII. (line 6) * module; bdb: pdb — The Python Debugger. (line 17) * module; binhex: binascii — Convert between binary and ASCII. (line 6) * module; builtins: The dir Function. (line 43) * module; builtins <1>: Complete Python programs. (line 6) * module; builtins <2>: Embedding Python<2>. (line 12) * module; builtins <3>: Initializing and finalizing the interpreter. (line 8) * module; builtins <4>: Sub-interpreter support. (line 26) * module; cmd: pdb — The Python Debugger. (line 17) * module; copy: copyreg — Register pickle support functions. (line 8) * module; crypt: pwd — The password database. (line 43) * module; dbm.gnu: The standard type hierarchy. (line 280) * module; dbm.gnu <1>: Restrictions. (line 6) * module; dbm.ndbm: The standard type hierarchy. (line 280) * module; dbm.ndbm <1>: Restrictions. (line 6) * module; errno: Concrete exceptions. (line 118) * module; glob: fnmatch — Unix filename pattern matching. (line 34) * module; imp: Built-in Functions. (line 1775) * module; importing: The import statement. (line 6) * module; io: The standard type hierarchy. (line 630) * module; json: Saving structured data with json. (line 6) * module; math: Numeric Types — int float complex. (line 104) * module; math <1>: Constants<3>. (line 47) * module; namespace: The standard type hierarchy. (line 536) * module; os: posix — The most common POSIX system calls. (line 12) * module; pickle: copy — Shallow and deep copy operations. (line 68) * module; pickle <1>: copyreg — Register pickle support functions. (line 8) * module; pickle <2>: shelve — Python object persistence. (line 8) * module; pickle <3>: marshal — Internal Python object serialization. (line 15) * module; pty: File Descriptor Operations. (line 355) * module; pwd: os path — Common pathname manipulations. (line 140) * module; pyexpat: xml parsers expat — Fast XML parsing using Expat. (line 20) * module; re: String Methods<2>. (line 6) * module; re <1>: fnmatch — Unix filename pattern matching. (line 8) * module; search; path: The Module Search Path. (line 6) * module; search; path <1>: linecache — Random access to text lines. (line 30) * module; search; path <2>: sys — System-specific parameters and functions. (line 1061) * module; search; path <3>: site — Site-specific configuration hook. (line 14) * module; search; path <4>: Embedding Python<2>. (line 12) * module; search; path <5>: Initializing and finalizing the interpreter. (line 8) * module; search; path <6>: Process-wide parameters. (line 120) * module; search; path <7>: Process-wide parameters. (line 133) * module; shelve: marshal — Internal Python object serialization. (line 15) * module; signal: _thread — Low-level threading API. (line 173) * module; signal <1>: Signal Handling<2>. (line 8) * module; sitecustomize: site — Site-specific configuration hook. (line 94) * module; socket: Internet Protocols and Support. (line 6) * module; stat: Files and Directories. (line 1002) * module; string: locale — Internationalization services. (line 460) * module; struct: Socket Objects. (line 551) * module; sys: Standard Modules. (line 6) * module; sys <1>: The try statement. (line 69) * module; sys <2>: Complete Python programs. (line 6) * module; sys <3>: Built-in Functions. (line 1217) * module; sys <4>: Embedding Python<2>. (line 12) * module; sys <5>: Initializing and finalizing the interpreter. (line 8) * module; sys <6>: Sub-interpreter support. (line 26) * module; types: Type Objects. (line 6) * module; urllib.request: http client — HTTP protocol client. (line 8) * module; usercustomize: site — Site-specific configuration hook. (line 105) * module; uu: binascii — Convert between binary and ASCII. (line 6) * module; _locale: locale — Internationalization services. (line 16) * module; _thread: High-level API. (line 45) * module; __main__: Resolution of names. (line 50) * module; __main__ <1>: Complete Python programs. (line 6) * module; __main__ <2>: Complete Python programs. (line 19) * module; __main__ <3>: runpy — Locating and executing Python modules. (line 30) * module; __main__ <4>: runpy — Locating and executing Python modules. (line 98) * module; __main__ <5>: Embedding Python<2>. (line 12) * module; __main__ <6>: Initializing and finalizing the interpreter. (line 8) * module; __main__ <7>: Sub-interpreter support. (line 26) * ModuleFinder (class in modulefinder): modulefinder — Find modules used by a script. (line 26) * modulefinder (module): modulefinder — Find modules used by a script. (line 6) * ModuleInfo (class in pkgutil): pkgutil — Package extension utility. (line 13) * ModuleNotFoundError: Concrete exceptions. (line 51) * modules (in module sys): sys — System-specific parameters and functions. (line 1051) * modules (in module sys) <1>: Importing Modules<2>. (line 7) * modules (in module sys) <2>: Initializing and finalizing the interpreter. (line 8) * modules (modulefinder.ModuleFinder attribute): modulefinder — Find modules used by a script. (line 49) * ModuleSpec (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 352) * modules_cleanup() (in module test.support): test support — Utilities for the Python test suite. (line 773) * modules_setup() (in module test.support): test support — Utilities for the Python test suite. (line 769) * ModuleType (class in types): Standard Interpreter Types. (line 117) * ModuleType (in module types): Module Objects. (line 8) * module_for_loader() (in module importlib.util): importlib util – Utility code for importers. (line 133) * module_from_spec() (in module importlib.util): importlib util – Utility code for importers. (line 117) * module_repr() (importlib.abc.Loader method): importlib abc – Abstract base classes related to import. (line 272) * modulo: Binary arithmetic operations. (line 35) * monotonic() (in module time): Functions<2>. (line 161) * monotonic_ns() (in module time): Functions<2>. (line 174) * month (datetime.date attribute): date Objects. (line 106) * month (datetime.datetime attribute): datetime Objects. (line 268) * month() (in module calendar): calendar — General calendar-related functions. (line 339) * monthcalendar() (in module calendar): calendar — General calendar-related functions. (line 328) * monthdatescalendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 89) * monthdays2calendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 95) * monthdayscalendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 101) * monthrange() (in module calendar): calendar — General calendar-related functions. (line 323) * month_abbr (in module calendar): calendar — General calendar-related functions. (line 383) * month_name (in module calendar): calendar — General calendar-related functions. (line 376) * Morsel (class in http.cookies): Morsel Objects. (line 6) * most_common() (collections.Counter method): Counter objects. (line 77) * mouseinterval() (in module curses): Functions<3>. (line 276) * mousemask() (in module curses): Functions<3>. (line 283) * move() (curses.panel.Panel method): Panel Objects. (line 35) * move() (curses.window method): Window Objects. (line 393) * move() (in module shutil): Directory and files operations. (line 302) * move() (mmap.mmap method): mmap — Memory-mapped file support. (line 218) * move() (tkinter.ttk.Treeview method): ttk Treeview. (line 221) * move_file() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 498) * move_file() (in module distutils.file_util): distutils file_util — Single file operations. (line 34) * move_to_end() (collections.OrderedDict method): OrderedDict objects. (line 53) * MozillaCookieJar (class in http.cookiejar): FileCookieJar subclasses and co-operation with web browsers. (line 9) * MRO: Glossary. (line 845) * mro() (class method): Special Attributes. (line 40) * msg (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 40) * msg (json.JSONDecodeError attribute): Exceptions<13>. (line 11) * msg (re.error attribute): Module Contents. (line 362) * msg (traceback.TracebackException attribute): TracebackException Objects. (line 59) * msg() (telnetlib.Telnet method): Telnet Objects. (line 78) * msi: msilib — Read and write Microsoft Installer files. (line 8) * msilib (module): msilib — Read and write Microsoft Installer files. (line 6) * msvcrt (module): msvcrt — Useful routines from the MS VC++ runtime. (line 6) * mtime (gzip.GzipFile attribute): gzip — Support for gzip files. (line 140) * mtime (tarfile.TarInfo attribute): TarInfo Objects. (line 51) * mtime() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 39) * mt_interact() (telnetlib.Telnet method): Telnet Objects. (line 117) * mul() (in module audioop): audioop — Manipulate raw audio data. (line 169) * mul() (in module operator): operator — Standard operators as functions. (line 116) * MultiCall (class in xmlrpc.client): MultiCall Objects. (line 9) * MULTILINE (in module re): Module Contents. (line 101) * MultiLoopChildWatcher (class in asyncio): Process Watchers. (line 100) * multimode() (in module statistics): Function details. (line 257) * MultipartConversionError: email errors Exception and Defect classes. (line 42) * multiplication: Binary arithmetic operations. (line 16) * multiply() (decimal.Context method): Context objects. (line 388) * multiprocessing (module): multiprocessing — Process-based parallelism. (line 6) * multiprocessing.connection (module): Listeners and Clients. (line 6) * multiprocessing.dummy (module): The multiprocessing dummy module. (line 6) * multiprocessing.Manager() (in module multiprocessing.sharedctypes): Managers. (line 12) * multiprocessing.managers (module): Managers. (line 18) * multiprocessing.pool (module): Process Pools. (line 6) * multiprocessing.sharedctypes (module): The multiprocessing sharedctypes module. (line 6) * multiprocessing.shared_memory (module): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 6) * mutable: Glossary. (line 849) * mutable object: Objects values and types. (line 11) * mutable sequence; loop over: The for statement. (line 44) * mutable; sequence; types: Mutable Sequence Types. (line 6) * MutableMapping (class in collections.abc): Collections Abstract Base Classes. (line 182) * MutableMapping (class in typing): Classes functions and decorators. (line 225) * MutableSequence (class in collections.abc): Collections Abstract Base Classes. (line 159) * MutableSequence (class in typing): Classes functions and decorators. (line 233) * MutableSet (class in collections.abc): Collections Abstract Base Classes. (line 177) * MutableSet (class in typing): Classes functions and decorators. (line 213) * mvderwin() (curses.window method): Window Objects. (line 397) * mvwin() (curses.window method): Window Objects. (line 404) * myrights() (imaplib.IMAP4 method): IMAP4 Objects. (line 157) * name: Identifiers and keywords. (line 6) * name <1>: Binding of names. (line 6) * name <2>: Identifiers Names. (line 6) * name (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 65) * name (contextvars.ContextVar attribute): Context Variables. (line 24) * name (doctest.DocTest attribute): DocTest Objects. (line 30) * name (email.headerregistry.BaseHeader attribute): email headerregistry Custom Header Objects. (line 45) * name (hashlib.hash attribute): Hash algorithms. (line 105) * name (hmac.HMAC attribute): hmac — Keyed-Hashing for Message Authentication. (line 100) * name (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 28) * name (importlib.abc.FileLoader attribute): importlib abc – Abstract base classes related to import. (line 484) * name (importlib.machinery.ExtensionFileLoader attribute): importlib machinery – Importers and path hooks. (line 311) * name (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 368) * name (importlib.machinery.SourceFileLoader attribute): importlib machinery – Importers and path hooks. (line 224) * name (importlib.machinery.SourcelessFileLoader attribute): importlib machinery – Importers and path hooks. (line 268) * name (in module os): os — Miscellaneous operating system interfaces. (line 46) * NAME (in module token): token — Constants used with Python parse trees. (line 42) * name (inspect.Parameter attribute): Introspecting callables with the Signature object. (line 157) * name (io.FileIO attribute): Raw File I/O. (line 61) * name (multiprocessing.Process attribute): Process and exceptions. (line 67) * name (multiprocessing.shared_memory.SharedMemory attribute): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 91) * name (os.DirEntry attribute): Files and Directories. (line 847) * name (ossaudiodev.oss_audio_device attribute): Audio Device Objects. (line 234) * name (pyclbr.Class attribute): Class Objects<2>. (line 17) * name (pyclbr.Function attribute): Function Objects. (line 17) * name (tarfile.TarInfo attribute): TarInfo Objects. (line 43) * name (threading.Thread attribute): Thread Objects. (line 136) * name (xml.dom.Attr attribute): Attr Objects. (line 8) * name (xml.dom.DocumentType attribute): DocumentType Objects. (line 33) * name (zipfile.Path attribute): Path Objects. (line 21) * name() (in module unicodedata): unicodedata — Unicode Database. (line 25) * name2codepoint (in module html.entities): html entities — Definitions of HTML general entities. (line 30) * name; binding: The import statement. (line 6) * name; binding <1>: The import statement. (line 51) * name; binding <2>: Function definitions. (line 6) * name; binding <3>: Function definitions. (line 6) * name; binding <4>: Class definitions. (line 6) * name; mangling: Private Variables. (line 13) * name; mangling <1>: Identifiers Names. (line 14) * Named Shared Memory: multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 10) * named tuple: Glossary. (line 854) * NamedTemporaryFile() (in module tempfile): tempfile — Generate temporary files and directories. (line 71) * NamedTuple (class in typing): Classes functions and decorators. (line 488) * namedtuple() (in module collections): namedtuple Factory Function for Tuples with Named Fields. (line 11) * NameError: Concrete exceptions. (line 89) * NameError (built-in exception): Resolution of names. (line 16) * namelist() (zipfile.ZipFile method): ZipFile Objects. (line 105) * nameprep() (in module encodings.idna): encodings idna — Internationalized Domain Names in Applications. (line 47) * namer (logging.handlers.BaseRotatingHandler attribute): BaseRotatingHandler. (line 17) * namereplace_errors() (in module codecs): Error Handlers. (line 157) * namespace: Naming and binding. (line 6) * namespace <1>: Glossary. (line 880) * Namespace (class in argparse): The Namespace object. (line 6) * Namespace (class in multiprocessing.managers): Managers. (line 226) * namespace package: Glossary. (line 894) * namespace() (imaplib.IMAP4 method): IMAP4 Objects. (line 162) * Namespace() (multiprocessing.managers.SyncManager method): Managers. (line 176) * NamespaceErr: Exceptions<16>. (line 66) * namespaceURI (xml.dom.Node attribute): Node Objects. (line 74) * NAMESPACE_DNS (in module uuid): uuid — UUID objects according to RFC 4122. (line 203) * NAMESPACE_OID (in module uuid): uuid — UUID objects according to RFC 4122. (line 212) * NAMESPACE_URL (in module uuid): uuid — UUID objects according to RFC 4122. (line 208) * NAMESPACE_X500 (in module uuid): uuid — UUID objects according to RFC 4122. (line 216) * NaN: Built-in Functions. (line 584) * nan (in module cmath): Constants<3>. (line 33) * nan (in module math): Constants<2>. (line 31) * nanj (in module cmath): Constants<3>. (line 40) * NannyNag: tabnanny — Detection of ambiguous indentation. (line 37) * napms() (in module curses): Functions<3>. (line 292) * nargs (optparse.Option attribute): Option attributes. (line 42) * native_id (threading.Thread attribute): Thread Objects. (line 156) * nbytes (memoryview attribute): Memory Views. (line 375) * ncurses_version (in module curses): Constants<6>. (line 23) * ndiff() (in module difflib): difflib — Helpers for computing deltas. (line 232) * ndim (memoryview attribute): Memory Views. (line 441) * ne (2to3 fixer): Fixers. (line 201) * ne() (in module operator): operator — Standard operators as functions. (line 24) * needs_input (bz2.BZ2Decompressor attribute): Incremental de compression. (line 85) * needs_input (lzma.LZMADecompressor attribute): Compressing and decompressing data in memory. (line 175) * neg() (in module operator): operator — Standard operators as functions. (line 128) * negation: Unary arithmetic and bitwise operations. (line 10) * nested scope: Glossary. (line 903) * netmask (ipaddress.IPv4Network attribute): Network objects. (line 101) * netmask (ipaddress.IPv6Network attribute): Network objects. (line 312) * NetmaskValueError: Custom Exceptions. (line 13) * netrc (class in netrc): netrc — netrc file processing. (line 13) * netrc (module): netrc — netrc file processing. (line 6) * NetrcParseError: netrc — netrc file processing. (line 36) * netscape (http.cookiejar.CookiePolicy attribute): CookiePolicy Objects. (line 68) * network (ipaddress.IPv4Interface attribute): Interface objects. (line 28) * network (ipaddress.IPv6Interface attribute): Interface objects. (line 76) * Network News Transfer Protocol: nntplib — NNTP protocol client. (line 8) * network_address (ipaddress.IPv4Network attribute): Network objects. (line 86) * network_address (ipaddress.IPv6Network attribute): Network objects. (line 306) * new() (in module hashlib): Hash algorithms. (line 55) * new() (in module hmac): hmac — Keyed-Hashing for Message Authentication. (line 12) * new-style class: Glossary. (line 913) * newer() (in module distutils.dep_util): distutils dep_util — Dependency checking. (line 10) * newer_group() (in module distutils.dep_util): distutils dep_util — Dependency checking. (line 24) * newer_pairwise() (in module distutils.dep_util): distutils dep_util — Dependency checking. (line 17) * newfunc (C type): Slot Type typedefs. (line 41) * newgroups() (nntplib.NNTP method): Methods<3>. (line 80) * NEWLINE (in module token): token — Constants used with Python parse trees. (line 48) * NEWLINE token: Logical lines. (line 6) * NEWLINE token <1>: Compound statements. (line 54) * newlines (io.TextIOBase attribute): Text I/O<2>. (line 24) * newnews() (nntplib.NNTP method): Methods<3>. (line 95) * newpad() (in module curses): Functions<3>. (line 296) * NewType() (in module typing): Classes functions and decorators. (line 607) * newwin() (in module curses): Functions<3>. (line 316) * new_alignment() (formatter.writer method): The Writer Interface. (line 17) * new_child() (collections.ChainMap method): ChainMap objects. (line 46) * new_class() (in module types): Dynamic Type Creation. (line 6) * new_compiler() (in module distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 48) * new_event_loop() (asyncio.AbstractEventLoopPolicy method): Policy Objects. (line 27) * new_event_loop() (in module asyncio): Event Loop. (line 61) * new_font() (formatter.writer method): The Writer Interface. (line 25) * new_margin() (formatter.writer method): The Writer Interface. (line 35) * new_module() (in module imp): imp — Access the import internals. (line 124) * new_panel() (in module curses.panel): Functions<4>. (line 12) * new_spacing() (formatter.writer method): The Writer Interface. (line 42) * new_styles() (formatter.writer method): The Writer Interface. (line 46) * next (2to3 fixer): Fixers. (line 205) * next (pdb command): Debugger Commands. (line 168) * next() (built-in function): Built-in Functions. (line 982) * next() (nntplib.NNTP method): Methods<3>. (line 233) * next() (tarfile.TarFile method): TarFile Objects. (line 130) * next() (tkinter.ttk.Treeview method): ttk Treeview. (line 232) * nextfile() (in module fileinput): fileinput — Iterate over lines from multiple input streams. (line 116) * nextkey() (dbm.gnu.gdbm method): dbm gnu — GNU’s reinterpretation of dbm. (line 93) * nextSibling (xml.dom.Node attribute): Node Objects. (line 42) * next_minus() (decimal.Context method): Context objects. (line 392) * next_minus() (decimal.Decimal method): Decimal objects. (line 399) * next_plus() (decimal.Context method): Context objects. (line 396) * next_plus() (decimal.Decimal method): Decimal objects. (line 405) * next_toward() (decimal.Context method): Context objects. (line 400) * next_toward() (decimal.Decimal method): Decimal objects. (line 411) * ngettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 47) * ngettext() (gettext.NullTranslations method): The NullTranslations class. (line 41) * ngettext() (in module gettext): GNU gettext API. (line 54) * nice() (in module os): Process Management. (line 318) * nis (module): nis — Interface to Sun’s NIS Yellow Pages. (line 6) * NL (in module token): token — Constants used with Python parse trees. (line 265) * nl() (in module curses): Functions<3>. (line 326) * nlargest() (in module heapq): heapq — Heap queue algorithm. (line 106) * nlst() (ftplib.FTP method): FTP Objects. (line 179) * nl_langinfo() (in module locale): locale — Internationalization services. (line 172) * NNTP (class in nntplib): nntplib — NNTP protocol client. (line 54) * NNTP; protocol: nntplib — NNTP protocol client. (line 8) * NNTPDataError: nntplib — NNTP protocol client. (line 153) * NNTPError: nntplib — NNTP protocol client. (line 122) * nntplib (module): nntplib — NNTP protocol client. (line 6) * NNTPPermanentError: nntplib — NNTP protocol client. (line 143) * NNTPProtocolError: nntplib — NNTP protocol client. (line 148) * NNTPReplyError: nntplib — NNTP protocol client. (line 133) * NNTPTemporaryError: nntplib — NNTP protocol client. (line 138) * nntp_implementation (nntplib.NNTP attribute): Attributes. (line 14) * NNTP_SSL (class in nntplib): nntplib — NNTP protocol client. (line 93) * nntp_version (nntplib.NNTP attribute): Attributes. (line 6) * nocbreak() (in module curses): Functions<3>. (line 332) * NoDataAllowedErr: Exceptions<16>. (line 83) * node() (in module platform): Cross Platform. (line 41) * nodelay() (curses.window method): Window Objects. (line 408) * nodeName (xml.dom.Node attribute): Node Objects. (line 79) * NodeTransformer (class in ast): ast Helpers. (line 154) * nodeType (xml.dom.Node attribute): Node Objects. (line 8) * nodeValue (xml.dom.Node attribute): Node Objects. (line 88) * NodeVisitor (class in ast): ast Helpers. (line 119) * noecho() (in module curses): Functions<3>. (line 337) * NOEXPR (in module locale): locale — Internationalization services. (line 251) * NoModificationAllowedErr: Exceptions<16>. (line 88) * nonblock() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 75) * NonCallableMagicMock (class in unittest.mock): Magic Mock. (line 21) * NonCallableMock (class in unittest.mock): The Mock Class. (line 558) * None (Built-in object): Truth Value Testing. (line 15) * None (built-in variable): Built-in Constants. (line 18) * nonl() (in module curses): Functions<3>. (line 341) * nonzero (2to3 fixer): Fixers. (line 211) * noop() (imaplib.IMAP4 method): IMAP4 Objects. (line 166) * noop() (poplib.POP3 method): POP3 Objects. (line 78) * NoOptionError: Exceptions<5>. (line 32) * NOP (opcode): Python Bytecode Instructions. (line 55) * noqiflush() (in module curses): Functions<3>. (line 351) * noraw() (in module curses): Functions<3>. (line 359) * NoReturn (in module typing): Classes functions and decorators. (line 781) * NormalDist (class in statistics): NormalDist objects. (line 13) * normalize() (decimal.Context method): Context objects. (line 404) * normalize() (decimal.Decimal method): Decimal objects. (line 419) * normalize() (in module locale): locale — Internationalization services. (line 356) * normalize() (in module unicodedata): unicodedata — Unicode Database. (line 81) * normalize() (xml.dom.Node method): Node Objects. (line 141) * NORMALIZE_WHITESPACE (in module doctest): Option Flags. (line 39) * normalvariate() (in module random): Real-valued distributions. (line 70) * NORMAL_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 80) * normcase() (in module os.path): os path — Common pathname manipulations. (line 275) * normpath() (in module os.path): os path — Common pathname manipulations. (line 284) * NoSectionError: Exceptions<5>. (line 10) * NoSuchMailboxError: Exceptions<14>. (line 13) * NotADirectoryError: OS exceptions. (line 86) * notation: Notation. (line 6) * notationDecl() (xml.sax.handler.DTDHandler method): DTDHandler Objects. (line 8) * NotationDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 272) * notations (xml.dom.DocumentType attribute): DocumentType Objects. (line 46) * NotConnected: http client — HTTP protocol client. (line 133) * NoteBook (class in tkinter.tix): Manager Widgets. (line 22) * Notebook (class in tkinter.ttk): ttk Notebook. (line 6) * NotEmptyError: Exceptions<14>. (line 20) * NOTEQUAL (in module token): token — Constants used with Python parse trees. (line 138) * NotFoundErr: Exceptions<16>. (line 72) * notify() (asyncio.Condition method): Condition. (line 55) * notify() (threading.Condition method): Condition Objects. (line 152) * notify_all() (asyncio.Condition method): Condition. (line 68) * notify_all() (threading.Condition method): Condition Objects. (line 172) * notimeout() (curses.window method): Window Objects. (line 412) * NotImplemented (built-in variable): Built-in Constants. (line 25) * NotImplementedError: Concrete exceptions. (line 95) * NotStandaloneHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 323) * NotSupportedErr: Exceptions<16>. (line 78) * NotSupportedError: Exceptions<4>. (line 40) * not_() (in module operator): operator — Standard operators as functions. (line 49) * noutrefresh() (curses.window method): Window Objects. (line 420) * now() (datetime.datetime class method): datetime Objects. (line 60) * no_proxy: urllib request — Extensible library for opening URLs. (line 303) * no_tracing() (in module test.support): test support — Utilities for the Python test suite. (line 643) * no_type_check() (in module typing): Classes functions and decorators. (line 716) * no_type_check_decorator() (in module typing): Classes functions and decorators. (line 726) * npgettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 79) * npgettext() (gettext.NullTranslations method): The NullTranslations class. (line 55) * npgettext() (in module gettext): GNU gettext API. (line 77) * NSIG (in module signal): Module contents<2>. (line 164) * nsmallest() (in module heapq): heapq — Heap queue algorithm. (line 114) * NTEventLogHandler (class in logging.handlers): NTEventLogHandler. (line 11) * ntohl() (in module socket): Other functions<2>. (line 179) * ntohs() (in module socket): Other functions<2>. (line 186) * ntransfercmd() (ftplib.FTP method): FTP Objects. (line 157) * NT_OFFSET (in module token): token — Constants used with Python parse trees. (line 256) * null; operation: The pass statement. (line 6) * null; operation <1>: The pass statement. (line 6) * nullcontext() (in module contextlib): Utilities. (line 147) * NullFormatter (class in formatter): Formatter Implementations. (line 10) * NullHandler (class in logging): NullHandler. (line 12) * NullImporter (class in imp): imp — Access the import internals. (line 345) * NullTranslations (class in gettext): The NullTranslations class. (line 13) * NullWriter (class in formatter): Writer Implementations. (line 10) * number: Numeric literals. (line 6) * Number (class in numbers): numbers — Numeric abstract base classes. (line 15) * NUMBER (in module token): token — Constants used with Python parse trees. (line 44) * numbers (module): numbers — Numeric abstract base classes. (line 6) * number_class() (decimal.Context method): Context objects. (line 408) * number_class() (decimal.Decimal method): Decimal objects. (line 428) * numerator (fractions.Fraction attribute): fractions — Rational numbers. (line 90) * numerator (numbers.Rational attribute): The numeric tower. (line 47) * numeric literal: Numeric literals. (line 6) * numeric() (in module unicodedata): unicodedata — Unicode Database. (line 43) * numeric; conversions: Numeric Types — int float complex. (line 104) * numeric; literals: Numeric Types — int float complex. (line 19) * Numerical Python: Built-in Functions. (line 1486) * numinput() (in module turtle): Input methods. (line 22) * numliterals (2to3 fixer): Fixers. (line 215) * num_addresses (ipaddress.IPv4Network attribute): Network objects. (line 128) * num_addresses (ipaddress.IPv6Network attribute): Network objects. (line 324) * num_tickets (ssl.SSLContext attribute): SSL Contexts. (line 573) * N_TOKENS (in module token): token — Constants used with Python parse trees. (line 254) * n_waiting (threading.Barrier attribute): Barrier Objects. (line 97) * obj (memoryview attribute): Memory Views. (line 364) * object: Objects values and types. (line 6) * object <1>: Glossary. (line 921) * object (built-in class): Built-in Functions. (line 989) * object (UnicodeError attribute): Concrete exceptions. (line 350) * object.__slots__ (built-in variable): __slots__. (line 13) * object; asynchronous-generator: Asynchronous generator functions. (line 55) * object; Boolean: The standard type hierarchy. (line 93) * object; Boolean <1>: Numeric Types — int float complex. (line 6) * object; built-in function: The standard type hierarchy. (line 485) * object; built-in function <1>: Calls. (line 132) * object; built-in method: The standard type hierarchy. (line 498) * object; built-in method <1>: Calls. (line 132) * object; bytearray: Mutable Sequence Types. (line 6) * object; bytearray <1>: Binary Sequence Types — bytes bytearray memoryview. (line 6) * object; bytearray <2>: Bytearray Objects. (line 6) * object; bytearray <3>: Byte Array Objects. (line 6) * object; bytes: Binary Sequence Types — bytes bytearray memoryview. (line 6) * object; bytes <1>: Bytes Objects. (line 6) * object; bytes <2>: Bytes Objects<2>. (line 9) * object; callable: The standard type hierarchy. (line 292) * object; callable <1>: Slicings. (line 38) * object; Capsule: Capsules<2>. (line 6) * object; class: The standard type hierarchy. (line 573) * object; class <1>: Calls. (line 137) * object; class <2>: Class definitions. (line 6) * object; class instance: The standard type hierarchy. (line 573) * object; class instance <1>: The standard type hierarchy. (line 600) * object; class instance <2>: Calls. (line 141) * object; code: The standard type hierarchy. (line 649) * object; code <1>: Methods. (line 43) * object; code <2>: marshal — Internal Python object serialization. (line 30) * object; code <3>: Cell Objects. (line 53) * object; complex: The standard type hierarchy. (line 119) * object; complex number: Numeric Types — int float complex. (line 6) * object; complex number <1>: Complex Number Objects. (line 6) * object; deallocation: Finalization and De-allocation. (line 6) * object; dictionary: The standard type hierarchy. (line 260) * object; dictionary <1>: The standard type hierarchy. (line 573) * object; dictionary <2>: Basic customization. (line 223) * object; dictionary <3>: Dictionary displays. (line 6) * object; dictionary <4>: Subscriptions. (line 6) * object; dictionary <5>: Assignment statements. (line 116) * object; dictionary <6>: Mapping Types — dict. (line 6) * object; dictionary <7>: Dictionary Objects. (line 6) * object; Ellipsis: The standard type hierarchy. (line 41) * object; file: Reading and Writing Files. (line 6) * object; file <1>: File Objects. (line 6) * object; finalization: Finalization and De-allocation. (line 6) * object; floating point: The standard type hierarchy. (line 107) * object; floating point <1>: Numeric Types — int float complex. (line 6) * object; floating point <2>: Floating Point Objects. (line 6) * object; frame: The standard type hierarchy. (line 709) * object; frozenset: The standard type hierarchy. (line 242) * object; frozenset <1>: Set Objects. (line 6) * object; function: The standard type hierarchy. (line 297) * object; function <1>: The standard type hierarchy. (line 485) * object; function <2>: Calls. (line 123) * object; function <3>: Calls. (line 132) * object; function <4>: Function definitions. (line 6) * object; function <5>: Function Objects<3>. (line 6) * object; generator: The standard type hierarchy. (line 687) * object; generator <1>: Generator expressions. (line 6) * object; generator <2>: Yield expressions. (line 108) * object; immutable: The standard type hierarchy. (line 146) * object; immutable sequence: The standard type hierarchy. (line 146) * object; instance: The standard type hierarchy. (line 573) * object; instance <1>: The standard type hierarchy. (line 600) * object; instance <2>: Calls. (line 141) * object; instancemethod: Instance Method Objects. (line 6) * object; integer: The standard type hierarchy. (line 77) * object; integer <1>: Numeric Types — int float complex. (line 6) * object; integer <2>: Integer Objects. (line 6) * object; io.StringIO: Text Sequence Type — str. (line 35) * object; list: The standard type hierarchy. (line 200) * object; list <1>: List displays. (line 6) * object; list <2>: Attribute references. (line 10) * object; list <3>: Subscriptions. (line 6) * object; list <4>: Slicings. (line 6) * object; list <5>: Assignment statements. (line 108) * object; list <6>: Mutable Sequence Types. (line 6) * object; list <7>: Lists<2>. (line 6) * object; list <8>: List Objects. (line 6) * object; long integer: Integer Objects. (line 6) * object; mapping: The standard type hierarchy. (line 249) * object; mapping <1>: The standard type hierarchy. (line 621) * object; mapping <2>: Subscriptions. (line 6) * object; mapping <3>: Assignment statements. (line 116) * object; mapping <4>: Mapping Types — dict. (line 6) * object; mapping <5>: Container Objects. (line 6) * object; memoryview: Binary Sequence Types — bytes bytearray memoryview. (line 6) * object; memoryview <1>: Ellipsis Object. (line 11) * object; method: Instance Objects. (line 31) * object; method <1>: The standard type hierarchy. (line 388) * object; method <2>: The standard type hierarchy. (line 498) * object; method <3>: Calls. (line 132) * object; method <4>: Methods. (line 6) * object; method <5>: Method Objects<2>. (line 6) * object; module: The standard type hierarchy. (line 521) * object; module <1>: Attribute references. (line 10) * object; module <2>: Module Objects. (line 6) * object; mutable: The standard type hierarchy. (line 192) * object; mutable <1>: Assignment statements. (line 6) * object; mutable <2>: Assignment statements. (line 103) * object; mutable sequence: The standard type hierarchy. (line 192) * object; None: The standard type hierarchy. (line 20) * object; None <1>: Expression statements. (line 17) * object; None <2>: The None Object. (line 6) * object; NotImplemented: The standard type hierarchy. (line 28) * object; numeric: The standard type hierarchy. (line 47) * object; numeric <1>: The standard type hierarchy. (line 621) * object; numeric <2>: Comparisons<2>. (line 43) * object; numeric <3>: Numeric Types — int float complex. (line 6) * object; numeric <4>: Numeric Objects. (line 6) * object; range: Ranges. (line 6) * object; sequence: The standard type hierarchy. (line 127) * object; sequence <1>: The standard type hierarchy. (line 621) * object; sequence <2>: Subscriptions. (line 6) * object; sequence <3>: Slicings. (line 6) * object; sequence <4>: Membership test operations. (line 37) * object; sequence <5>: Assignment statements. (line 108) * object; sequence <6>: The for statement. (line 6) * object; sequence <7>: Common Sequence Operations. (line 6) * object; sequence <8>: Sequence Objects. (line 6) * object; set: The standard type hierarchy. (line 236) * object; set <1>: Set displays. (line 6) * object; set <2>: Set Types — set frozenset. (line 6) * object; set <3>: Set Objects. (line 6) * object; set type: The standard type hierarchy. (line 219) * object; slice: Emulating container types. (line 64) * object; socket: socket — Low-level networking interface. (line 17) * object; string: Subscriptions. (line 6) * object; string <1>: Slicings. (line 6) * object; string <2>: Ranges. (line 124) * object; traceback: The standard type hierarchy. (line 757) * object; traceback <1>: The raise statement. (line 21) * object; traceback <2>: The try statement. (line 69) * object; traceback <3>: sys — System-specific parameters and functions. (line 365) * object; traceback <4>: traceback — Print or retrieve a stack traceback. (line 16) * object; tuple: The standard type hierarchy. (line 172) * object; tuple <1>: Subscriptions. (line 6) * object; tuple <2>: Slicings. (line 6) * object; tuple <3>: Expression lists. (line 11) * object; tuple <4>: Immutable Sequence Types. (line 6) * object; tuple <5>: Tuples. (line 6) * object; tuple <6>: Tuple Objects. (line 6) * object; type: Built-in Functions. (line 1666) * object; type <1>: Objects Types and Reference Counts. (line 6) * object; type <2>: Type Objects<2>. (line 6) * object; user-defined function: The standard type hierarchy. (line 297) * object; user-defined function <1>: Calls. (line 123) * object; user-defined function <2>: Function definitions. (line 6) * object; user-defined method: The standard type hierarchy. (line 388) * objects; comparing: Comparisons<2>. (line 43) * object_filenames() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 467) * objobjargproc (C type): Slot Type typedefs. (line 122) * objobjproc (C type): Slot Type typedefs. (line 120) * obufcount() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 218) * obuffree() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 223) * oct() (built-in function): Built-in Functions. (line 999) * octal literal: Numeric literals. (line 6) * octal; literals: Numeric Types — int float complex. (line 19) * octdigits (in module string): String constants. (line 32) * offset (traceback.TracebackException attribute): TracebackException Objects. (line 54) * offset (xml.parsers.expat.ExpatError attribute): ExpatError Exceptions. (line 32) * OK (in module curses): Constants<6>. (line 13) * old_value (contextvars.contextvars.Token.Token attribute): Context Variables. (line 87) * OleDLL (class in ctypes): Loading shared libraries. (line 32) * onclick() (in module turtle): Using screen events. (line 56) * ondrag() (in module turtle): Using events. (line 57) * onecmd() (cmd.Cmd method): Cmd Objects. (line 57) * onkey() (in module turtle): Using screen events. (line 12) * onkeypress() (in module turtle): Using screen events. (line 35) * onkeyrelease() (in module turtle): Using screen events. (line 12) * onrelease() (in module turtle): Using events. (line 30) * onscreenclick() (in module turtle): Using screen events. (line 56) * ontimer() (in module turtle): Using screen events. (line 86) * OP (in module token): token — Constants used with Python parse trees. (line 242) * open() (built-in function): Built-in Functions. (line 1023) * open() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 91) * open() (imaplib.IMAP4 method): IMAP4 Objects. (line 170) * open() (in module aifc): aifc — Read and write AIFF and AIFC files. (line 30) * open() (in module bz2): De compression of files. (line 6) * open() (in module codecs): codecs — Codec registry and base classes. (line 167) * open() (in module dbm): dbm — Interfaces to Unix “databases”. (line 35) * open() (in module dbm.dumb): dbm dumb — Portable DBM implementation. (line 30) * open() (in module dbm.gnu): dbm gnu — GNU’s reinterpretation of dbm. (line 27) * open() (in module dbm.ndbm): dbm ndbm — Interface based on ndbm. (line 31) * open() (in module gzip): gzip — Support for gzip files. (line 28) * open() (in module io): High-level Module Interface. (line 12) * open() (in module lzma): Reading and writing compressed files. (line 6) * open() (in module os): File Descriptor Operations. (line 259) * open() (in module ossaudiodev): ossaudiodev — Access to OSS-compatible audio devices. (line 42) * open() (in module shelve): shelve — Python object persistence. (line 17) * open() (in module sunau): sunau — Read and write Sun AU files. (line 48) * open() (in module tarfile): tarfile — Read and write tar archive files. (line 35) * open() (in module tokenize): Tokenizing Input. (line 100) * open() (in module wave): wave — Read and write WAV files. (line 17) * open() (in module webbrowser): webbrowser — Convenient Web-browser controller. (line 50) * open() (pathlib.Path method): Methods<2>. (line 245) * open() (pipes.Template method): Template Objects. (line 42) * open() (tarfile.TarFile class method): TarFile Objects. (line 96) * open() (telnetlib.Telnet method): Telnet Objects. (line 65) * open() (urllib.request.OpenerDirector method): OpenerDirector Objects. (line 46) * open() (urllib.request.URLopener method): Legacy interface. (line 98) * open() (webbrowser.controller method): Browser Controller Objects. (line 9) * open() (zipfile.Path method): Path Objects. (line 25) * open() (zipfile.ZipFile method): ZipFile Objects. (line 109) * OpenDatabase() (in module msilib): msilib — Read and write Microsoft Installer files. (line 45) * OpenerDirector (class in urllib.request): urllib request — Extensible library for opening URLs. (line 266) * openfp() (in module sunau): sunau — Read and write Sun AU files. (line 66) * openfp() (in module wave): wave — Read and write WAV files. (line 48) * OpenKey() (in module winreg): Functions<11>. (line 291) * OpenKeyEx() (in module winreg): Functions<11>. (line 291) * openlog() (in module syslog): syslog — Unix syslog library routines. (line 36) * openmixer() (in module ossaudiodev): ossaudiodev — Access to OSS-compatible audio devices. (line 70) * openpty() (in module os): File Descriptor Operations. (line 353) * openpty() (in module pty): pty — Pseudo-terminal utilities. (line 29) * OpenSSL; (use in module hashlib): Hash algorithms. (line 21) * OpenSSL; (use in module ssl): ssl — TLS/SSL wrapper for socket objects. (line 8) * OPENSSL_VERSION (in module ssl): Constants<9>. (line 441) * OPENSSL_VERSION_INFO (in module ssl): Constants<9>. (line 451) * OPENSSL_VERSION_NUMBER (in module ssl): Constants<9>. (line 461) * OpenView() (msilib.Database method): Database Objects. (line 6) * open_binary() (in module importlib.resources): importlib resources – Resources. (line 53) * open_code() (in module io): High-level Module Interface. (line 22) * open_connection() (in module asyncio): Streams. (line 42) * open_new() (in module webbrowser): webbrowser — Convenient Web-browser controller. (line 67) * open_new() (webbrowser.controller method): Browser Controller Objects. (line 15) * open_new_tab() (in module webbrowser): webbrowser — Convenient Web-browser controller. (line 72) * open_new_tab() (webbrowser.controller method): Browser Controller Objects. (line 21) * open_osfhandle() (in module msvcrt): File Operations. (line 44) * open_resource() (importlib.abc.ResourceReader method): importlib abc – Abstract base classes related to import. (line 319) * open_text() (in module importlib.resources): importlib resources – Resources. (line 64) * open_unix_connection() (in module asyncio): Streams. (line 98) * open_unknown() (urllib.request.URLopener method): Legacy interface. (line 109) * open_urlresource() (in module test.support): test support — Utilities for the Python test suite. (line 714) * OperationalError: Exceptions<4>. (line 32) * operations on; dictionary; type: Mapping Types — dict. (line 6) * operations on; integer; types: Bitwise Operations on Integer Types. (line 6) * operations on; list; type: Mutable Sequence Types. (line 16) * operations on; mapping; types: Mapping Types — dict. (line 6) * operations on; numeric; types: Numeric Types — int float complex. (line 94) * operations on; sequence; types: Common Sequence Operations. (line 21) * operations on; sequence; types <1>: Mutable Sequence Types. (line 16) * operator (2to3 fixer): Fixers. (line 219) * operator (module): operator — Standard operators as functions. (line 6) * operator; !=: Comparisons. (line 6) * operator; != <1>: Comparisons<2>. (line 6) * operator; % (percent): Binary arithmetic operations. (line 35) * operator; % (percent) <1>: Numeric Types — int float complex. (line 27) * operator; & (ampersand): Binary bitwise operations. (line 12) * operator; & (ampersand) <1>: Bitwise Operations on Integer Types. (line 6) * operator; * (asterisk): Binary arithmetic operations. (line 16) * operator; * (asterisk) <1>: Numeric Types — int float complex. (line 27) * operator; **: The power operator. (line 6) * operator; ** <1>: Numeric Types — int float complex. (line 27) * operator; + (plus): Unary arithmetic and bitwise operations. (line 13) * operator; + (plus) <1>: Binary arithmetic operations. (line 60) * operator; + (plus) <2>: Numeric Types — int float complex. (line 27) * operator; - (minus): Unary arithmetic and bitwise operations. (line 10) * operator; - (minus) <1>: Binary arithmetic operations. (line 66) * operator; - (minus) <2>: Numeric Types — int float complex. (line 27) * operator; / (slash): Binary arithmetic operations. (line 28) * operator; / (slash) <1>: Numeric Types — int float complex. (line 27) * operator; //: Binary arithmetic operations. (line 28) * operator; // <1>: Numeric Types — int float complex. (line 27) * operator; < (less): Comparisons. (line 6) * operator; < (less) <1>: Comparisons<2>. (line 6) * operator; <<: Shifting operations. (line 6) * operator; << <1>: Bitwise Operations on Integer Types. (line 6) * operator; <=: Comparisons. (line 6) * operator; <= <1>: Comparisons<2>. (line 6) * operator; ==: Comparisons. (line 6) * operator; == <1>: Comparisons<2>. (line 6) * operator; > (greater): Comparisons. (line 6) * operator; > (greater) <1>: Comparisons<2>. (line 6) * operator; >=: Comparisons. (line 6) * operator; >= <1>: Comparisons<2>. (line 6) * operator; >>: Shifting operations. (line 6) * operator; >> <1>: Bitwise Operations on Integer Types. (line 6) * operator; @ (at): Binary arithmetic operations. (line 23) * operator; and: Boolean operations. (line 21) * operator; and <1>: Truth Value Testing. (line 23) * operator; and <2>: Boolean Operations — and or not. (line 22) * operator; comparison: Comparisons<2>. (line 6) * operator; in: Membership test operations. (line 37) * operator; in <1>: Comparisons<2>. (line 64) * operator; in <2>: Common Sequence Operations. (line 21) * operator; is: Membership test operations. (line 40) * operator; is <1>: Comparisons<2>. (line 6) * operator; is not: Membership test operations. (line 40) * operator; is not <1>: Comparisons<2>. (line 6) * operator; not: Boolean operations. (line 18) * operator; not <1>: Boolean Operations — and or not. (line 22) * operator; not in: Membership test operations. (line 37) * operator; not in <1>: Comparisons<2>. (line 64) * operator; not in <2>: Common Sequence Operations. (line 21) * operator; or: Boolean operations. (line 25) * operator; or <1>: Truth Value Testing. (line 23) * operator; or <2>: Boolean Operations — and or not. (line 22) * operator; overloading: Special method names. (line 6) * operator; precedence: Operator precedence. (line 6) * operator; ^ (caret): Binary bitwise operations. (line 15) * operator; ^ (caret) <1>: Bitwise Operations on Integer Types. (line 6) * operator; | (vertical bar): Binary bitwise operations. (line 18) * operator; | (vertical bar) <1>: Bitwise Operations on Integer Types. (line 6) * operator; ~ (tilde): Unary arithmetic and bitwise operations. (line 15) * operator; ~ (tilde) <1>: Bitwise Operations on Integer Types. (line 6) * operators: Operators. (line 6) * opmap (in module dis): Opcode collections. (line 13) * opname (in module dis): Opcode collections. (line 9) * optimize() (in module pickletools): Programmatic Interface<2>. (line 31) * OPTIMIZED_BYTECODE_SUFFIXES (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 30) * optim_args_from_interpreter_flags() (in module test.support): test support — Utilities for the Python test suite. (line 397) * Optional (in module typing): Classes functions and decorators. (line 828) * OptionGroup (class in optparse): Grouping Options. (line 12) * OptionMenu (class in tkinter.tix): Basic Widgets. (line 49) * OptionParser (class in optparse): Creating the parser. (line 9) * Options (class in ssl): Constants<9>. (line 340) * options (doctest.Example attribute): Example Objects. (line 53) * options (ssl.SSLContext attribute): SSL Contexts. (line 584) * options() (configparser.ConfigParser method): ConfigParser Objects. (line 102) * optionxform() (configparser.ConfigParser method): ConfigParser Objects. (line 279) * optparse (module): optparse — Parser for command line options. (line 6) * OP_ALL (in module ssl): Constants<9>. (line 209) * OP_CIPHER_SERVER_PREFERENCE (in module ssl): Constants<9>. (line 298) * OP_ENABLE_MIDDLEBOX_COMPAT (in module ssl): Constants<9>. (line 322) * OP_NO_COMPRESSION (in module ssl): Constants<9>. (line 331) * OP_NO_RENEGOTIATION (in module ssl): Constants<9>. (line 288) * OP_NO_SSLv2 (in module ssl): Constants<9>. (line 217) * OP_NO_SSLv3 (in module ssl): Constants<9>. (line 227) * OP_NO_TICKET (in module ssl): Constants<9>. (line 344) * OP_NO_TLSv1 (in module ssl): Constants<9>. (line 237) * OP_NO_TLSv1_1 (in module ssl): Constants<9>. (line 249) * OP_NO_TLSv1_2 (in module ssl): Constants<9>. (line 261) * OP_NO_TLSv1_3 (in module ssl): Constants<9>. (line 273) * OP_SINGLE_DH_USE (in module ssl): Constants<9>. (line 306) * OP_SINGLE_ECDH_USE (in module ssl): Constants<9>. (line 314) * ord() (built-in function): Built-in Functions. (line 1264) * OrderedDict (class in collections): OrderedDict objects. (line 39) * OrderedDict (class in typing): Classes functions and decorators. (line 367) * ordered_attributes (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 107) * origin (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 381) * origin_req_host (urllib.request.Request attribute): Request Objects. (line 30) * origin_server (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 288) * or_() (in module operator): operator — Standard operators as functions. (line 133) * os (module): os — Miscellaneous operating system interfaces. (line 6) * os.path (module): os path — Common pathname manipulations. (line 6) * OSError: Concrete exceptions. (line 113) * ossaudiodev (module): ossaudiodev — Access to OSS-compatible audio devices. (line 6) * OSSAudioError: ossaudiodev — Access to OSS-compatible audio devices. (line 29) * os_environ (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 166) * output: Expression statements. (line 17) * output (subprocess.CalledProcessError attribute): Using the subprocess Module. (line 205) * output (subprocess.TimeoutExpired attribute): Using the subprocess Module. (line 172) * output (unittest.TestCase attribute): Test cases. (line 433) * output() (http.cookies.BaseCookie method): Cookie Objects. (line 24) * output() (http.cookies.Morsel method): Morsel Objects. (line 72) * OutputChecker (class in doctest): OutputChecker objects. (line 6) * OutputString() (http.cookies.Morsel method): Morsel Objects. (line 87) * output_charset (email.charset.Charset attribute): email charset Representing character sets. (line 74) * output_charset() (gettext.NullTranslations method): The NullTranslations class. (line 87) * output_codec (email.charset.Charset attribute): email charset Representing character sets. (line 88) * output_difference() (doctest.OutputChecker method): OutputChecker objects. (line 27) * over() (nntplib.NNTP method): Methods<3>. (line 167) * Overflow (class in decimal): Signals. (line 67) * OverflowError: Concrete exceptions. (line 177) * OverflowError (built-in exception): Integer Objects. (line 107) * OverflowError (built-in exception) <1>: Integer Objects. (line 146) * OverflowError (built-in exception) <2>: Integer Objects. (line 188) * OverflowError (built-in exception) <3>: Integer Objects. (line 199) * OverflowError (built-in exception) <4>: Integer Objects. (line 210) * OverflowError (built-in exception) <5>: Integer Objects. (line 222) * overlap() (statistics.NormalDist method): NormalDist objects. (line 96) * overlaps() (ipaddress.IPv4Network method): Network objects. (line 152) * overlaps() (ipaddress.IPv6Network method): Network objects. (line 336) * overlay() (curses.window method): Window Objects. (line 427) * overload() (in module typing): Classes functions and decorators. (line 661) * overwrite() (curses.window method): Window Objects. (line 440) * owner() (pathlib.Path method): Methods<2>. (line 257) * O_APPEND (in module os): File Descriptor Operations. (line 304) * O_ASYNC (in module os): File Descriptor Operations. (line 336) * O_BINARY (in module os): File Descriptor Operations. (line 326) * O_CLOEXEC (in module os): File Descriptor Operations. (line 314) * O_CREAT (in module os): File Descriptor Operations. (line 304) * O_DIRECT (in module os): File Descriptor Operations. (line 336) * O_DIRECTORY (in module os): File Descriptor Operations. (line 336) * O_DSYNC (in module os): File Descriptor Operations. (line 314) * O_EXCL (in module os): File Descriptor Operations. (line 304) * O_EXLOCK (in module os): File Descriptor Operations. (line 336) * O_NDELAY (in module os): File Descriptor Operations. (line 314) * O_NOATIME (in module os): File Descriptor Operations. (line 336) * O_NOCTTY (in module os): File Descriptor Operations. (line 314) * O_NOFOLLOW (in module os): File Descriptor Operations. (line 336) * O_NOINHERIT (in module os): File Descriptor Operations. (line 326) * O_NONBLOCK (in module os): File Descriptor Operations. (line 314) * O_PATH (in module os): File Descriptor Operations. (line 336) * O_RANDOM (in module os): File Descriptor Operations. (line 326) * O_RDONLY (in module os): File Descriptor Operations. (line 304) * O_RDWR (in module os): File Descriptor Operations. (line 304) * O_RSYNC (in module os): File Descriptor Operations. (line 314) * O_SEQUENTIAL (in module os): File Descriptor Operations. (line 326) * O_SHLOCK (in module os): File Descriptor Operations. (line 336) * O_SHORT_LIVED (in module os): File Descriptor Operations. (line 326) * O_SYNC (in module os): File Descriptor Operations. (line 314) * O_TEMPORARY (in module os): File Descriptor Operations. (line 326) * O_TEXT (in module os): File Descriptor Operations. (line 326) * O_TMPFILE (in module os): File Descriptor Operations. (line 336) * O_TRUNC (in module os): File Descriptor Operations. (line 304) * O_WRONLY (in module os): File Descriptor Operations. (line 304) * p (pdb command): Debugger Commands. (line 233) * pack() (in module struct): Functions and Exceptions. (line 13) * pack() (mailbox.MH method): MH. (line 64) * pack() (struct.Struct method): Classes<2>. (line 25) * package: Packages<2>. (line 6) * package <1>: site — Site-specific configuration hook. (line 64) * package <2>: Glossary. (line 927) * Package (in module importlib.resources): importlib resources – Resources. (line 37) * package variable; __all__: Importing Modules<2>. (line 7) * package; namespace: Namespace packages. (line 6) * package; portion: Namespace packages. (line 6) * package; regular: Regular packages. (line 6) * packed (ipaddress.IPv4Address attribute): Address objects. (line 65) * packed (ipaddress.IPv6Address attribute): Address objects. (line 163) * Packer (class in xdrlib): xdrlib — Encode and decode XDR data. (line 18) * packing (widgets): The Packer. (line 6) * packing; binary; data: struct — Interpret bytes as packed binary data. (line 8) * pack_array() (xdrlib.Packer method): Packer Objects. (line 86) * pack_bytes() (xdrlib.Packer method): Packer Objects. (line 54) * pack_double() (xdrlib.Packer method): Packer Objects. (line 26) * pack_farray() (xdrlib.Packer method): Packer Objects. (line 78) * pack_float() (xdrlib.Packer method): Packer Objects. (line 22) * pack_fopaque() (xdrlib.Packer method): Packer Objects. (line 38) * pack_fstring() (xdrlib.Packer method): Packer Objects. (line 32) * pack_into() (in module struct): Functions and Exceptions. (line 19) * pack_into() (struct.Struct method): Classes<2>. (line 30) * pack_list() (xdrlib.Packer method): Packer Objects. (line 61) * pack_opaque() (xdrlib.Packer method): Packer Objects. (line 49) * pack_string() (xdrlib.Packer method): Packer Objects. (line 43) * PAGER: pydoc — Documentation generator and online help system. (line 47) * pair_content() (in module curses): Functions<3>. (line 364) * pair_number() (in module curses): Functions<3>. (line 370) * PanedWindow (class in tkinter.tix): Manager Widgets. (line 6) * parameter: Glossary. (line 936) * Parameter (class in inspect): Introspecting callables with the Signature object. (line 142) * parameter; call semantics: Calls. (line 25) * parameter; difference from argument: How can I pass optional or keyword parameters from one function to another?. (line 16) * parameter; function definition: The with statement. (line 103) * ParameterizedMIMEHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 255) * parameters (inspect.Signature attribute): Introspecting callables with the Signature object. (line 79) * params (email.headerregistry.ParameterizedMIMEHeader attribute): email headerregistry Custom Header Objects. (line 263) * pardir (in module os): Miscellaneous System Information. (line 87) * paren (2to3 fixer): Fixers. (line 251) * parent (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 409) * parent (pyclbr.Class attribute): Class Objects<2>. (line 25) * parent (pyclbr.Function attribute): Function Objects. (line 25) * parent (urllib.request.BaseHandler attribute): BaseHandler Objects. (line 25) * parent() (tkinter.ttk.Treeview method): ttk Treeview. (line 237) * parenthesized form: Parenthesized forms. (line 6) * parentNode (xml.dom.Node attribute): Node Objects. (line 17) * parents (collections.ChainMap attribute): ChainMap objects. (line 59) * parent_process() (in module multiprocessing): Miscellaneous<3>. (line 35) * paretovariate() (in module random): Real-valued distributions. (line 83) * parse() (doctest.DocTestParser method): DocTestParser objects. (line 29) * parse() (email.parser.BytesParser method): Parser API. (line 34) * parse() (email.parser.Parser method): Parser API. (line 86) * parse() (in module ast): ast Helpers. (line 9) * parse() (in module cgi): Functions<8>. (line 9) * parse() (in module xml.dom.minidom): xml dom minidom — Minimal DOM implementation. (line 37) * parse() (in module xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees. (line 86) * parse() (in module xml.etree.ElementTree): Functions<6>. (line 160) * parse() (in module xml.sax): xml sax — Support for SAX2 parsers. (line 39) * parse() (string.Formatter method): Custom String Formatting. (line 40) * parse() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 29) * parse() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 59) * Parse() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 8) * parse() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 8) * parseaddr() (in module email.utils): email utils Miscellaneous utilities. (line 59) * parsebytes() (email.parser.BytesParser method): Parser API. (line 54) * parsedate() (in module email.utils): email utils Miscellaneous utilities. (line 96) * parsedate_to_datetime() (in module email.utils): email utils Miscellaneous utilities. (line 119) * parsedate_tz() (in module email.utils): email utils Miscellaneous utilities. (line 108) * ParseError (class in xml.etree.ElementTree): Exceptions<15>. (line 6) * ParseFile() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 16) * ParseFlags() (in module imaplib): imaplib — IMAP4 protocol client. (line 118) * parser: Lexical analysis. (line 6) * Parser (class in email.parser): Parser API. (line 75) * parser (module): parser — Access Python parse trees. (line 6) * ParserCreate() (in module xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat. (line 46) * ParserError: Exceptions and Error Handling. (line 11) * ParseResult (class in urllib.parse): Structured Parse Results. (line 48) * ParseResultBytes (class in urllib.parse): Structured Parse Results. (line 73) * parsestr() (email.parser.Parser method): Parser API. (line 96) * parseString() (in module xml.dom.minidom): xml dom minidom — Minimal DOM implementation. (line 50) * parseString() (in module xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees. (line 99) * parseString() (in module xml.sax): xml sax — Support for SAX2 parsers. (line 50) * parse_and_bind() (in module readline): Init file. (line 8) * parse_args() (argparse.ArgumentParser method): The parse_args method. (line 6) * PARSE_COLNAMES (in module sqlite3): Module functions and constants. (line 38) * parse_config_h() (in module sysconfig): Other functions<3>. (line 57) * PARSE_DECLTYPES (in module sqlite3): Module functions and constants. (line 25) * parse_header() (in module cgi): Functions<8>. (line 41) * parse_headers() (in module http.client): http client — HTTP protocol client. (line 108) * parse_intermixed_args() (argparse.ArgumentParser method): Intermixed parsing. (line 6) * parse_known_args() (argparse.ArgumentParser method): Partial parsing. (line 6) * parse_known_intermixed_args() (argparse.ArgumentParser method): Intermixed parsing. (line 9) * parse_multipart() (in module cgi): Functions<8>. (line 19) * parse_qs() (in module urllib.parse): URL Parsing. (line 140) * parse_qsl() (in module urllib.parse): URL Parsing. (line 186) * parsing; Python source code: parser — Access Python parse trees. (line 6) * ParsingError: Exceptions<5>. (line 65) * partial (asyncio.IncompleteReadError attribute): Exceptions<9>. (line 54) * partial() (imaplib.IMAP4 method): IMAP4 Objects. (line 182) * partial() (in module functools): functools — Higher-order functions and operations on callable objects. (line 215) * partialmethod (class in functools): functools — Higher-order functions and operations on callable objects. (line 246) * parties (threading.Barrier attribute): Barrier Objects. (line 93) * partition() (bytearray method): Bytes and Bytearray Operations. (line 132) * partition() (bytes method): Bytes and Bytearray Operations. (line 132) * partition() (str method): String Methods<2>. (line 331) * pass_() (poplib.POP3 method): POP3 Objects. (line 36) * Paste: Help menu Shell and Editor. (line 30) * patch() (in module test.support): test support — Utilities for the Python test suite. (line 943) * patch() (in module unittest.mock): patch. (line 10) * patch.dict() (in module unittest.mock): patch dict. (line 6) * patch.multiple() (in module unittest.mock): patch multiple. (line 6) * patch.object() (in module unittest.mock): patch object. (line 6) * patch.stopall() (in module unittest.mock): patch methods start and stop. (line 70) * PATH: Changes in the Python API. (line 143) * PATH <1>: Changes in ‘python’ Command Behavior<2>. (line 6) * PATH <2>: Changes in ‘python’ Command Behavior<2>. (line 11) * PATH <3>: Changes in ‘python’ Command Behavior<2>. (line 12) * PATH <4>: The Module Search Path. (line 16) * PATH <5>: Executable Python Scripts. (line 11) * PATH <6>: Environment variables. (line 27) * PATH <7>: Miscellaneous. (line 16) * PATH <8>: Installation steps. (line 32) * PATH <9>: Installation steps. (line 56) * PATH <10>: Installing Without UI. (line 57) * PATH <11>: Excursus Setting environment variables. (line 23) * PATH <12>: Excursus Setting environment variables. (line 35) * PATH <13>: Finding the Python executable. (line 14) * PATH <14>: Finding the Python executable. (line 21) * PATH <15>: Finding the Python executable. (line 22) * PATH <16>: Python Launcher for Windows. (line 13) * PATH <17>: From the command-line. (line 9) * PATH <18>: From the command-line. (line 38) * PATH <19>: Shebang Lines. (line 48) * PATH <20>: Shebang Lines. (line 50) * PATH <21>: Process Management. (line 45) * PATH <22>: Process Management. (line 86) * PATH <23>: Process Management. (line 89) * PATH <24>: Process Management. (line 92) * PATH <25>: Process Management. (line 453) * PATH <26>: Process Management. (line 539) * PATH <27>: Process Management. (line 543) * PATH <28>: Process Management. (line 545) * PATH <29>: Miscellaneous System Information. (line 118) * PATH <30>: webbrowser — Convenient Web-browser controller. (line 214) * PATH <31>: Installing your CGI script on a Unix system. (line 29) * PATH <32>: Common problems and solutions. (line 23) * PATH <33>: site — Site-specific configuration hook. (line 59) * PATH <34>: Embedding Python<2>. (line 31) * PATH <35>: Embedding Python<2>. (line 37) * PATH <36>: How do I make a Python script executable on Unix?. (line 24) * PATH <37>: How do I make a Python script executable on Unix?. (line 28) * Path (class in pathlib): Concrete paths. (line 11) * Path (class in zipfile): Path Objects. (line 6) * path (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 41) * path (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 92) * path (importlib.abc.FileLoader attribute): importlib abc – Abstract base classes related to import. (line 488) * path (importlib.machinery.ExtensionFileLoader attribute): importlib machinery – Importers and path hooks. (line 315) * path (importlib.machinery.FileFinder attribute): importlib machinery – Importers and path hooks. (line 186) * path (importlib.machinery.SourceFileLoader attribute): importlib machinery – Importers and path hooks. (line 228) * path (importlib.machinery.SourcelessFileLoader attribute): importlib machinery – Importers and path hooks. (line 272) * path (in module sys): sys — System-specific parameters and functions. (line 1059) * path (in module sys) <1>: Embedding Python<2>. (line 12) * path (in module sys) <2>: Initializing and finalizing the interpreter. (line 8) * path (in module sys) <3>: Process-wide parameters. (line 120) * path (in module sys) <4>: Process-wide parameters. (line 133) * path (os.DirEntry attribute): Files and Directories. (line 857) * path based finder: The Path Based Finder. (line 6) * path based finder <1>: Glossary. (line 1008) * Path browser: File menu Shell and Editor. (line 22) * path entry: Glossary. (line 988) * path entry finder: Glossary. (line 993) * path entry hook: Glossary. (line 1002) * path hooks: Import hooks. (line 6) * path() (in module importlib.resources): importlib resources – Resources. (line 105) * path-like object: Glossary. (line 1013) * path; configuration; file: site — Site-specific configuration hook. (line 64) * path; operations: pathlib — Object-oriented filesystem paths. (line 10) * path; operations <1>: os path — Common pathname manipulations. (line 9) * pathconf() (in module os): Files and Directories. (line 548) * pathconf_names (in module os): Files and Directories. (line 572) * PathEntryFinder (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 96) * PATHEXT: Other Improvements<2>. (line 30) * PATHEXT <1>: Installing Without UI. (line 58) * PathFinder (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 107) * pathlib (module): pathlib — Object-oriented filesystem paths. (line 6) * PathLike (class in os): Process Parameters. (line 113) * pathname2url() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 147) * pathsep (in module os): Miscellaneous System Information. (line 115) * path_hook() (importlib.machinery.FileFinder class method): importlib machinery – Importers and path hooks. (line 206) * path_hooks (in module sys): sys — System-specific parameters and functions. (line 1084) * path_importer_cache (in module sys): sys — System-specific parameters and functions. (line 1093) * path_mtime() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 554) * path_return_ok() (http.cookiejar.CookiePolicy method): CookiePolicy Objects. (line 56) * path_stats() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 532) * path_stats() (importlib.machinery.SourceFileLoader method): importlib machinery – Importers and path hooks. (line 237) * Pattern (class in typing): Classes functions and decorators. (line 479) * pattern (re.error attribute): Module Contents. (line 366) * pattern (re.Pattern attribute): Regular Expression Objects. (line 118) * pause() (in module signal): Module contents<2>. (line 265) * pause_reading() (asyncio.ReadTransport method): Read-only Transports. (line 12) * pause_writing() (asyncio.BaseProtocol method): Base Protocol. (line 40) * PAX_FORMAT (in module tarfile): tarfile — Read and write tar archive files. (line 230) * pax_headers (tarfile.TarFile attribute): TarFile Objects. (line 253) * pax_headers (tarfile.TarInfo attribute): TarInfo Objects. (line 88) * pbkdf2_hmac() (in module hashlib): Key derivation. (line 11) * pd() (in module turtle): Drawing state. (line 6) * Pdb (class in pdb): pdb — The Python Debugger. (line 17) * Pdb (class in pdb) <1>: pdb — The Python Debugger. (line 146) * pdb (module): pdb — The Python Debugger. (line 6) * pdf() (statistics.NormalDist method): NormalDist objects. (line 68) * peek() (bz2.BZ2File method): De compression of files. (line 77) * peek() (gzip.GzipFile method): gzip — Support for gzip files. (line 125) * peek() (io.BufferedReader method): Buffered Streams. (line 73) * peek() (lzma.LZMAFile method): Reading and writing compressed files. (line 85) * peek() (weakref.finalize method): weakref — Weak references. (line 265) * peer (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 95) * PEM_cert_to_DER_cert() (in module ssl): Certificate handling. (line 96) * pen() (in module turtle): Drawing state. (line 33) * pencolor() (in module turtle): Color control. (line 6) * pending (ssl.MemoryBIO attribute): Memory BIO Support<2>. (line 139) * pending() (ssl.SSLSocket method): SSL Sockets. (line 313) * PendingDeprecationWarning: Warnings. (line 22) * pendown() (in module turtle): Drawing state. (line 6) * pensize() (in module turtle): Drawing state. (line 18) * penup() (in module turtle): Drawing state. (line 12) * PEP: Glossary. (line 1025) * PERCENT (in module token): token — Constants used with Python parse trees. (line 122) * PERCENTEQUAL (in module token): token — Constants used with Python parse trees. (line 186) * Performance: timeit — Measure execution time of small code snippets. (line 8) * perf_counter() (in module time): Functions<2>. (line 180) * perf_counter_ns() (in module time): Functions<2>. (line 191) * perm() (in module math): Number-theoretic and representation functions. (line 177) * PermissionError: OS exceptions. (line 92) * permutations() (in module itertools): Itertool functions. (line 400) * Persist() (msilib.SummaryInformation method): Summary Information Objects. (line 29) * persistence: pickle — Python object serialization. (line 8) * persistent; objects: pickle — Python object serialization. (line 8) * persistent_id (pickle protocol): Persistence of External Objects. (line 6) * persistent_id() (pickle.Pickler method): Module Interface. (line 160) * persistent_load (pickle protocol): Persistence of External Objects. (line 6) * persistent_load() (pickle.Unpickler method): Module Interface. (line 274) * pformat() (in module pprint): pprint — Data pretty printer. (line 81) * pformat() (pprint.PrettyPrinter method): PrettyPrinter Objects. (line 8) * PF_CAN (in module socket): Constants<8>. (line 93) * PF_PACKET (in module socket): Constants<8>. (line 144) * PF_RDS (in module socket): Constants<8>. (line 154) * pgettext() (gettext.GNUTranslations method): The GNUTranslations class. (line 68) * pgettext() (gettext.NullTranslations method): The NullTranslations class. (line 47) * pgettext() (in module gettext): GNU gettext API. (line 73) * PGO (in module test.support): test support — Utilities for the Python test suite. (line 91) * phase() (in module cmath): Conversions to and from polar coordinates. (line 22) * Philbrick, Geoff: Keyword Parameters for Extension Functions. (line 25) * physical line: Logical lines. (line 6) * physical line <1>: Explicit line joining. (line 6) * physical line <2>: String and Bytes literals. (line 72) * pi (in module cmath): Constants<3>. (line 6) * pi (in module math): Constants<2>. (line 6) * pi() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 56) * pickle (module): pickle — Python object serialization. (line 6) * pickle() (in module copyreg): copyreg — Register pickle support functions. (line 23) * PickleBuffer (class in pickle): Module Interface. (line 301) * PickleError: Module Interface. (line 95) * Pickler (class in pickle): Module Interface. (line 121) * pickletools (module): pickletools — Tools for pickle developers. (line 6) * pickletools command line option; -a: Command line options<3>. (line 6) * pickletools command line option; –annotate: Command line options<3>. (line 6) * pickletools command line option; –indentlevel=: Command line options<3>. (line 14) * pickletools command line option; -l: Command line options<3>. (line 14) * pickletools command line option; -m: Command line options<3>. (line 18) * pickletools command line option; –memo: Command line options<3>. (line 18) * pickletools command line option; -o: Command line options<3>. (line 10) * pickletools command line option; –output=: Command line options<3>. (line 10) * pickletools command line option; -p: Command line options<3>. (line 23) * pickletools command line option; –preamble=: Command line options<3>. (line 23) * pickling; objects: pickle — Python object serialization. (line 8) * PicklingError: Module Interface. (line 100) * pid (asyncio.asyncio.subprocess.Process attribute): Interacting with Subprocesses. (line 132) * pid (multiprocessing.Process attribute): Process and exceptions. (line 107) * pid (subprocess.Popen attribute): Popen Objects. (line 138) * PIPE (in module subprocess): Using the subprocess Module. (line 140) * Pipe() (in module multiprocessing): Pipes and Queues. (line 74) * pipe() (in module os): File Descriptor Operations. (line 365) * pipe2() (in module os): File Descriptor Operations. (line 376) * pipes (module): pipes — Interface to shell pipelines. (line 6) * PIPE_BUF (in module select): select — Waiting for I/O completion. (line 157) * pipe_connection_lost() (asyncio.SubprocessProtocol method): Subprocess Protocols. (line 19) * pipe_data_received() (asyncio.SubprocessProtocol method): Subprocess Protocols. (line 10) * PIPE_MAX_SIZE (in module test.support): test support — Utilities for the Python test suite. (line 95) * pkgutil (module): pkgutil — Package extension utility. (line 6) * PKG_DIRECTORY (in module imp): imp — Access the import internals. (line 327) * placeholder (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 266) * PLAT: distutils util — Miscellaneous other utility functions. (line 79) * platform (in module sys): sys — System-specific parameters and functions. (line 1106) * platform (in module sys) <1>: Process-wide parameters. (line 172) * platform (module): platform — Access to underlying platform’s identifying data. (line 6) * platform() (in module platform): Cross Platform. (line 46) * PlaySound() (in module winsound): winsound — Sound-playing interface for Windows. (line 20) * plist; file: plistlib — Generate and parse Mac OS X plist files. (line 8) * plistlib (module): plistlib — Generate and parse Mac OS X plist files. (line 6) * plock() (in module os): Process Management. (line 325) * plus: Unary arithmetic and bitwise operations. (line 13) * PLUS (in module token): token — Constants used with Python parse trees. (line 82) * plus() (decimal.Context method): Context objects. (line 412) * PLUSEQUAL (in module token): token — Constants used with Python parse trees. (line 170) * pm() (in module pdb): pdb — The Python Debugger. (line 136) * POINTER() (in module ctypes): Utility functions. (line 149) * pointer() (in module ctypes): Utility functions. (line 155) * polar() (in module cmath): Conversions to and from polar coordinates. (line 42) * Policy (class in email.policy): email policy Policy Objects. (line 128) * poll() (in module select): select — Waiting for I/O completion. (line 84) * poll() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 42) * poll() (select.devpoll method): /dev/poll Polling Objects. (line 65) * poll() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 93) * poll() (select.poll method): Polling Objects. (line 77) * poll() (subprocess.Popen method): Popen Objects. (line 8) * PollSelector (class in selectors): Classes<3>. (line 171) * Pool (class in multiprocessing.pool): Process Pools. (line 9) * pop() (array.array method): array — Efficient arrays of numeric values. (line 204) * pop() (collections.deque method): deque objects. (line 87) * pop() (dict method): Mapping Types — dict. (line 178) * pop() (frozenset method): Set Types — set frozenset. (line 208) * pop() (mailbox.Mailbox method): Mailbox objects. (line 208) * pop() (sequence method): Mutable Sequence Types. (line 16) * POP3 (class in poplib): poplib — POP3 protocol client. (line 29) * POP3; protocol: poplib — POP3 protocol client. (line 8) * POP3_SSL (class in poplib): poplib — POP3 protocol client. (line 45) * Popen (class in subprocess): Popen Constructor. (line 11) * popen() (in module os): The standard type hierarchy. (line 630) * popen() (in module os) <1>: Process Management. (line 332) * popen() (in module os) <2>: select — Waiting for I/O completion. (line 138) * popitem() (collections.OrderedDict method): OrderedDict objects. (line 46) * popitem() (dict method): Mapping Types — dict. (line 184) * popitem() (mailbox.Mailbox method): Mailbox objects. (line 217) * popleft() (collections.deque method): deque objects. (line 92) * poplib (module): poplib — POP3 protocol client. (line 6) * PopupMenu (class in tkinter.tix): Basic Widgets. (line 53) * pop_alignment() (formatter.formatter method): The Formatter Interface. (line 97) * pop_all() (contextlib.ExitStack method): Utilities. (line 426) * POP_BLOCK (opcode): Python Bytecode Instructions. (line 372) * POP_EXCEPT (opcode): Python Bytecode Instructions. (line 377) * POP_FINALLY (opcode): Python Bytecode Instructions. (line 385) * pop_font() (formatter.formatter method): The Formatter Interface. (line 109) * POP_JUMP_IF_FALSE (opcode): Python Bytecode Instructions. (line 661) * POP_JUMP_IF_TRUE (opcode): Python Bytecode Instructions. (line 654) * pop_margin() (formatter.formatter method): The Formatter Interface. (line 121) * pop_source() (shlex.shlex method): shlex Objects. (line 63) * pop_style() (formatter.formatter method): The Formatter Interface. (line 132) * POP_TOP (opcode): Python Bytecode Instructions. (line 59) * port (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 36) * portion: Glossary. (line 1041) * port_specified (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 77) * pos (json.JSONDecodeError attribute): Exceptions<13>. (line 19) * pos (re.error attribute): Module Contents. (line 370) * pos (re.Match attribute): Match Objects. (line 164) * pos() (in module operator): operator — Standard operators as functions. (line 138) * pos() (in module turtle): Tell Turtle’s state. (line 6) * position (xml.etree.ElementTree.ParseError attribute): Exceptions<15>. (line 20) * position() (in module turtle): Tell Turtle’s state. (line 6) * positional argument: Glossary. (line 1047) * posix (module): posix — The most common POSIX system calls. (line 6) * POSIX Shared Memory: multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 10) * POSIX; I/O control: termios — POSIX style tty control. (line 6) * POSIXLY_CORRECT: getopt — C-style parser for command line options. (line 71) * PosixPath (class in pathlib): Concrete paths. (line 22) * posix_fadvise() (in module os): File Descriptor Operations. (line 396) * POSIX_FADV_DONTNEED (in module os): File Descriptor Operations. (line 410) * POSIX_FADV_NOREUSE (in module os): File Descriptor Operations. (line 410) * POSIX_FADV_NORMAL (in module os): File Descriptor Operations. (line 410) * POSIX_FADV_RANDOM (in module os): File Descriptor Operations. (line 410) * POSIX_FADV_SEQUENTIAL (in module os): File Descriptor Operations. (line 410) * POSIX_FADV_WILLNEED (in module os): File Descriptor Operations. (line 410) * posix_fallocate() (in module os): File Descriptor Operations. (line 387) * posix_spawn() (in module os): Process Management. (line 355) * posix_spawnp() (in module os): Process Management. (line 445) * POSIX_SPAWN_CLOSE (in module os): Process Management. (line 383) * POSIX_SPAWN_DUP2 (in module os): Process Management. (line 389) * POSIX_SPAWN_OPEN (in module os): Process Management. (line 377) * post() (nntplib.NNTP method): Methods<3>. (line 278) * post() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 179) * postcmd() (cmd.Cmd method): Cmd Objects. (line 96) * postloop() (cmd.Cmd method): Cmd Objects. (line 114) * post_handshake_auth (ssl.SSLContext attribute): SSL Contexts. (line 602) * post_mortem() (in module pdb): pdb — The Python Debugger. (line 129) * post_setup() (venv.EnvBuilder method): API<2>. (line 104) * pow() (built-in function): Built-in Functions. (line 1271) * pow() (in module math): Power and logarithmic functions. (line 60) * pow() (in module operator): operator — Standard operators as functions. (line 143) * power() (decimal.Context method): Context objects. (line 418) * power; operation: The power operator. (line 6) * pp (pdb command): Debugger Commands. (line 242) * pp() (in module pprint): pprint — Data pretty printer. (line 93) * pprint (module): pprint — Data pretty printer. (line 6) * pprint() (in module pprint): pprint — Data pretty printer. (line 103) * pprint() (pprint.PrettyPrinter method): PrettyPrinter Objects. (line 14) * prcal() (in module calendar): calendar — General calendar-related functions. (line 344) * pread() (in module os): File Descriptor Operations. (line 424) * preadv() (in module os): File Descriptor Operations. (line 437) * preamble (email.message.EmailMessage attribute): email message Representing an email message. (line 680) * preamble (email.message.Message attribute): email message Message Representing an email message using the compat32 API. (line 690) * precmd() (cmd.Cmd method): Cmd Objects. (line 86) * prefix: Python-related paths and files. (line 7) * prefix <1>: Include Files. (line 37) * prefix <2>: Include Files. (line 40) * prefix <3>: Include Files. (line 47) * PREFIX (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 19) * prefix (in module sys): sys — System-specific parameters and functions. (line 1168) * prefix (xml.dom.Attr attribute): Attr Objects. (line 18) * prefix (xml.dom.Node attribute): Node Objects. (line 69) * prefix (zipimport.zipimporter attribute): zipimporter Objects. (line 74) * PREFIXES (in module site): Module contents<3>. (line 6) * prefixlen (ipaddress.IPv4Network attribute): Network objects. (line 132) * prefixlen (ipaddress.IPv6Network attribute): Network objects. (line 326) * preloop() (cmd.Cmd method): Cmd Objects. (line 108) * prepare() (logging.handlers.QueueHandler method): QueueHandler. (line 40) * prepare() (logging.handlers.QueueListener method): QueueListener. (line 54) * prepare_class() (in module types): Dynamic Type Creation. (line 23) * prepare_input_source() (in module xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 77) * prepend() (pipes.Template method): Template Objects. (line 37) * preprocess() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 433) * PrettyPrinter (class in pprint): pprint — Data pretty printer. (line 27) * prev() (tkinter.ttk.Treeview method): ttk Treeview. (line 242) * previousSibling (xml.dom.Node attribute): Node Objects. (line 32) * primary: Primaries. (line 6) * print (2to3 fixer): Fixers. (line 257) * print() (built-in function): Built-in Functions. (line 1306) * print() (built-in function); __str__() (object method): Basic customization. (line 129) * printable (in module string): String constants. (line 41) * printdir() (zipfile.ZipFile method): ZipFile Objects. (line 207) * printf-style formatting: printf-style String Formatting. (line 6) * printf-style formatting <1>: printf-style Bytes Formatting. (line 6) * print_callees() (pstats.Stats method): The Stats Class. (line 217) * print_callers() (pstats.Stats method): The Stats Class. (line 196) * print_directory() (in module cgi): Functions<8>. (line 60) * print_environ() (in module cgi): Functions<8>. (line 52) * print_environ_usage() (in module cgi): Functions<8>. (line 64) * print_exc() (in module traceback): traceback — Print or retrieve a stack traceback. (line 60) * print_exc() (timeit.Timer method): Python Interface. (line 133) * print_exception() (in module traceback): traceback — Print or retrieve a stack traceback. (line 33) * PRINT_EXPR (opcode): Python Bytecode Instructions. (line 311) * print_form() (in module cgi): Functions<8>. (line 56) * print_help() (argparse.ArgumentParser method): Printing help. (line 16) * print_last() (in module traceback): traceback — Print or retrieve a stack traceback. (line 65) * print_stack() (asyncio.Task method): Task Object. (line 190) * print_stack() (in module traceback): traceback — Print or retrieve a stack traceback. (line 72) * print_stats() (profile.Profile method): profile and cProfile Module Reference. (line 91) * print_stats() (pstats.Stats method): The Stats Class. (line 164) * print_tb() (in module traceback): traceback — Print or retrieve a stack traceback. (line 22) * print_usage() (argparse.ArgumentParser method): Printing help. (line 10) * print_usage() (optparse.OptionParser method): Other methods. (line 15) * print_version() (optparse.OptionParser method): Printing a version string. (line 26) * PriorityQueue (class in asyncio): Priority Queue. (line 6) * PriorityQueue (class in queue): queue — A synchronized queue class. (line 50) * PRIO_PGRP (in module os): Process Parameters. (line 271) * PRIO_PROCESS (in module os): Process Parameters. (line 271) * PRIO_USER (in module os): Process Parameters. (line 271) * private; names: Identifiers Names. (line 14) * prlimit() (in module resource): Resource Limits. (line 56) * prmonth() (calendar.TextCalendar method): calendar — General calendar-related functions. (line 143) * prmonth() (in module calendar): calendar — General calendar-related functions. (line 335) * ProactorEventLoop (class in asyncio): Event Loop Implementations. (line 29) * procedure; call: Expression statements. (line 17) * Process (class in multiprocessing): Process and exceptions. (line 6) * process() (logging.LoggerAdapter method): LoggerAdapter Objects. (line 16) * process; group: Process Parameters. (line 179) * process; group <1>: Process Parameters. (line 237) * process; id: Process Parameters. (line 243) * process; id of parent: Process Parameters. (line 247) * process; killing: Process Management. (line 289) * process; killing <1>: Process Management. (line 311) * process; scheduling priority: Process Parameters. (line 258) * process; scheduling priority <1>: Process Parameters. (line 389) * process; signalling: Process Management. (line 289) * process; signalling <1>: Process Management. (line 311) * ProcessError: Process and exceptions. (line 204) * processes, light-weight: _thread — Low-level threading API. (line 6) * ProcessingInstruction() (in module xml.etree.ElementTree): Functions<6>. (line 167) * processingInstruction() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 164) * ProcessingInstructionHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 236) * ProcessLookupError: OS exceptions. (line 98) * processor time: Functions<2>. (line 200) * processor time <1>: Functions<2>. (line 479) * processor() (in module platform): Cross Platform. (line 67) * ProcessPoolExecutor (class in concurrent.futures): ProcessPoolExecutor. (line 21) * process_exited() (asyncio.SubprocessProtocol method): Subprocess Protocols. (line 26) * process_message() (smtpd.SMTPServer method): SMTPServer Objects. (line 41) * process_request() (socketserver.BaseServer method): Server Objects<2>. (line 156) * process_time() (in module time): Functions<2>. (line 198) * process_time_ns() (in module time): Functions<2>. (line 208) * process_tokens() (in module tabnanny): tabnanny — Detection of ambiguous indentation. (line 42) * prod() (in module math): Number-theoretic and representation functions. (line 194) * product() (in module itertools): Itertool functions. (line 461) * Profile (class in profile): profile and cProfile Module Reference. (line 35) * profile (module): profile and cProfile Module Reference. (line 6) * profile function: threading — Thread-based parallelism. (line 132) * profile function <1>: sys — System-specific parameters and functions. (line 741) * profile function <2>: sys — System-specific parameters and functions. (line 1227) * profiler: sys — System-specific parameters and functions. (line 741) * profiler <1>: sys — System-specific parameters and functions. (line 1227) * profiling, deterministic: Introduction to the profilers. (line 6) * program: Complete Python programs. (line 6) * ProgrammingError: Exceptions<4>. (line 25) * Progressbar (class in tkinter.ttk): ttk Progressbar. (line 6) * prompt (cmd.Cmd attribute): Cmd Objects. (line 123) * prompts, interpreter: sys — System-specific parameters and functions. (line 1188) * prompt_user_passwd() (urllib.request.FancyURLopener method): Legacy interface. (line 184) * propagate (logging.Logger attribute): Logger Objects. (line 25) * property (built-in class): Built-in Functions. (line 1331) * property list: plistlib — Generate and parse Mac OS X plist files. (line 8) * PropertyMock (class in unittest.mock): The Mock Class. (line 627) * property_declaration_handler (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 101) * property_dom_node (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 108) * property_lexical_handler (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 94) * property_xml_string (in module xml.sax.handler): xml sax handler — Base classes for SAX handlers. (line 115) * proto (socket.socket attribute): Socket Objects. (line 603) * Protocol (class in asyncio): Base Protocols. (line 10) * Protocol (class in typing): Classes functions and decorators. (line 71) * protocol (ssl.SSLContext attribute): SSL Contexts. (line 625) * protocol; context management: Context Manager Types. (line 6) * protocol; iterator: Iterator Types. (line 6) * protocol; Telnet: telnetlib — Telnet client. (line 8) * ProtocolError (class in xmlrpc.client): ProtocolError Objects. (line 6) * PROTOCOL_SSLv2 (in module ssl): Constants<9>. (line 150) * PROTOCOL_SSLv23 (in module ssl): Constants<9>. (line 143) * PROTOCOL_SSLv3 (in module ssl): Constants<9>. (line 163) * PROTOCOL_TLS (in module ssl): Constants<9>. (line 118) * PROTOCOL_TLSv1 (in module ssl): Constants<9>. (line 177) * PROTOCOL_TLSv1_1 (in module ssl): Constants<9>. (line 185) * PROTOCOL_TLSv1_2 (in module ssl): Constants<9>. (line 196) * PROTOCOL_TLS_CLIENT (in module ssl): Constants<9>. (line 126) * PROTOCOL_TLS_SERVER (in module ssl): Constants<9>. (line 135) * protocol_version (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 154) * PROTOCOL_VERSION (imaplib.IMAP4 attribute): IMAP4 Objects. (line 376) * prot_c() (ftplib.FTP_TLS method): FTP_TLS Objects. (line 35) * prot_p() (ftplib.FTP_TLS method): FTP_TLS Objects. (line 31) * provisional API: Glossary. (line 1051) * provisional package: Glossary. (line 1071) * proxy() (in module weakref): weakref — Weak references. (line 131) * proxyauth() (imaplib.IMAP4 method): IMAP4 Objects. (line 187) * ProxyBasicAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 364) * ProxyDigestAuthHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 396) * ProxyHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 290) * ProxyType (in module weakref): weakref — Weak references. (line 294) * ProxyTypes (in module weakref): weakref — Weak references. (line 302) * pryear() (calendar.TextCalendar method): calendar — General calendar-related functions. (line 158) * ps1 (in module sys): sys — System-specific parameters and functions. (line 1185) * ps2 (in module sys): sys — System-specific parameters and functions. (line 1185) * pstats (module): The Stats Class. (line 7) * pstdev() (in module statistics): Function details. (line 271) * pthreads: _thread — Low-level threading API. (line 16) * pthread_getcpuclockid() (in module time): Functions<2>. (line 21) * pthread_kill() (in module signal): Module contents<2>. (line 282) * pthread_sigmask() (in module signal): Module contents<2>. (line 311) * pty (module): pty — Pseudo-terminal utilities. (line 6) * pu() (in module turtle): Drawing state. (line 12) * publicId (xml.dom.DocumentType attribute): DocumentType Objects. (line 17) * PullDom (class in xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees. (line 78) * punctuation (in module string): String constants. (line 36) * punctuation_chars (shlex.shlex attribute): shlex Objects. (line 183) * PurePath (class in pathlib): Pure paths. (line 10) * PurePath.anchor (in module pathlib): Methods and properties. (line 40) * PurePath.drive (in module pathlib): Methods and properties. (line 8) * PurePath.name (in module pathlib): Methods and properties. (line 94) * PurePath.parent (in module pathlib): Methods and properties. (line 66) * PurePath.parents (in module pathlib): Methods and properties. (line 53) * PurePath.parts (in module pathlib): Accessing individual parts. (line 9) * PurePath.root (in module pathlib): Methods and properties. (line 24) * PurePath.stem (in module pathlib): Methods and properties. (line 131) * PurePath.suffix (in module pathlib): Methods and properties. (line 109) * PurePath.suffixes (in module pathlib): Methods and properties. (line 120) * PurePosixPath (class in pathlib): Pure paths. (line 68) * PureProxy (class in smtpd): PureProxy Objects. (line 6) * PureWindowsPath (class in pathlib): Pure paths. (line 78) * purge() (in module re): Module Contents. (line 349) * Purpose.CLIENT_AUTH (in module ssl): Constants<9>. (line 502) * Purpose.SERVER_AUTH (in module ssl): Constants<9>. (line 493) * push() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 101) * push() (code.InteractiveConsole method): Interactive Console Objects. (line 28) * push() (contextlib.ExitStack method): Utilities. (line 393) * pushbutton() (msilib.Dialog method): GUI classes. (line 68) * push_alignment() (formatter.formatter method): The Formatter Interface. (line 90) * push_async_callback() (contextlib.AsyncExitStack method): Utilities. (line 473) * push_async_exit() (contextlib.AsyncExitStack method): Utilities. (line 468) * push_font() (formatter.formatter method): The Formatter Interface. (line 101) * push_margin() (formatter.formatter method): The Formatter Interface. (line 113) * push_source() (shlex.shlex method): shlex Objects. (line 56) * push_style() (formatter.formatter method): The Formatter Interface. (line 125) * push_token() (shlex.shlex method): shlex Objects. (line 16) * push_with_producer() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 109) * put() (asyncio.Queue method): Queue. (line 62) * put() (multiprocessing.Queue method): Pipes and Queues. (line 120) * put() (multiprocessing.SimpleQueue method): Pipes and Queues. (line 217) * put() (queue.Queue method): Queue Objects. (line 29) * put() (queue.SimpleQueue method): SimpleQueue Objects. (line 20) * putch() (in module msvcrt): Console I/O. (line 35) * putenv() (in module os): Process Parameters. (line 316) * putheader() (http.client.HTTPConnection method): HTTPConnection Objects. (line 136) * putp() (in module curses): Functions<3>. (line 376) * putrequest() (http.client.HTTPConnection method): HTTPConnection Objects. (line 125) * putwch() (in module msvcrt): Console I/O. (line 39) * putwin() (curses.window method): Window Objects. (line 453) * put_nowait() (asyncio.Queue method): Queue. (line 67) * put_nowait() (multiprocessing.Queue method): Pipes and Queues. (line 136) * put_nowait() (queue.Queue method): Queue Objects. (line 40) * put_nowait() (queue.SimpleQueue method): SimpleQueue Objects. (line 35) * pvariance() (in module statistics): Function details. (line 280) * pwd (module): pwd — The password database. (line 6) * pwd() (ftplib.FTP method): FTP Objects. (line 221) * pwrite() (in module os): File Descriptor Operations. (line 495) * pwritev() (in module os): File Descriptor Operations. (line 506) * PyAnySet_Check (C function): Set Objects. (line 55) * PyAnySet_CheckExact (C function): Set Objects. (line 60) * PyArg_Parse (C function): API Functions. (line 51) * PyArg_ParseTuple (C function): API Functions. (line 6) * PyArg_ParseTuple(): Extracting Parameters in Extension Functions. (line 6) * PyArg_ParseTupleAndKeywords (C function): API Functions. (line 20) * PyArg_ParseTupleAndKeywords(): Keyword Parameters for Extension Functions. (line 6) * PyArg_UnpackTuple (C function): API Functions. (line 63) * PyArg_ValidateKeywordArguments (C function): API Functions. (line 42) * PyArg_VaParse (C function): API Functions. (line 13) * PyArg_VaParseTupleAndKeywords (C function): API Functions. (line 34) * PyASCIIObject (C type): Unicode Type. (line 29) * PyAsyncMethods (C type): Async Object Structures. (line 8) * PyAsyncMethods.am_aiter (C member): Async Object Structures. (line 34) * PyAsyncMethods.am_anext (C member): Async Object Structures. (line 46) * PyAsyncMethods.am_await (C member): Async Object Structures. (line 22) * PyBool_Check (C function): Boolean Objects. (line 11) * PyBool_FromLong (C function): Boolean Objects. (line 37) * PyBufferProcs: Buffer Protocol. (line 20) * PyBufferProcs (C type): Buffer Object Structures. (line 6) * PyBufferProcs.bf_getbuffer (C member): Buffer Object Structures. (line 12) * PyBufferProcs.bf_releasebuffer (C member): Buffer Object Structures. (line 60) * PyBuffer_FillContiguousStrides (C function): Buffer-related functions. (line 77) * PyBuffer_FillInfo (C function): Buffer-related functions. (line 87) * PyBuffer_FromContiguous (C function): Buffer-related functions. (line 59) * PyBuffer_GetPointer (C function): Buffer-related functions. (line 53) * PyBuffer_IsContiguous (C function): Buffer-related functions. (line 46) * PyBuffer_Release (C function): Buffer-related functions. (line 32) * PyBuffer_SizeFromFormat (C function): Buffer-related functions. (line 41) * PyBuffer_ToContiguous (C function): Buffer-related functions. (line 66) * PyBUF_ANY_CONTIGUOUS (C macro): contiguity requests. (line 20) * PyBUF_CONTIG (C macro): compound requests. (line 36) * PyBUF_CONTIG_RO (C macro): compound requests. (line 39) * PyBUF_C_CONTIGUOUS (C macro): contiguity requests. (line 14) * PyBUF_FORMAT (C macro): readonly format. (line 14) * PyBUF_FULL (C macro): compound requests. (line 18) * PyBUF_FULL_RO (C macro): compound requests. (line 21) * PyBUF_F_CONTIGUOUS (C macro): contiguity requests. (line 17) * PyBUF_INDIRECT (C macro): shape strides suboffsets. (line 14) * PyBUF_ND (C macro): shape strides suboffsets. (line 20) * PyBUF_RECORDS (C macro): compound requests. (line 24) * PyBUF_RECORDS_RO (C macro): compound requests. (line 27) * PyBUF_SIMPLE (C macro): shape strides suboffsets. (line 23) * PyBUF_STRIDED (C macro): compound requests. (line 30) * PyBUF_STRIDED_RO (C macro): compound requests. (line 33) * PyBUF_STRIDES (C macro): shape strides suboffsets. (line 17) * PyBUF_WRITABLE (C macro): readonly format. (line 6) * PyByteArrayObject (C type): Byte Array Objects. (line 6) * PyByteArray_AsString (C function): Direct API functions. (line 23) * PyByteArray_AS_STRING (C function): Macros. (line 8) * PyByteArray_Check (C function): Type check macros. (line 6) * PyByteArray_CheckExact (C function): Type check macros. (line 11) * PyByteArray_Concat (C function): Direct API functions. (line 15) * PyByteArray_FromObject (C function): Direct API functions. (line 6) * PyByteArray_FromStringAndSize (C function): Direct API functions. (line 10) * PyByteArray_GET_SIZE (C function): Macros. (line 12) * PyByteArray_Resize (C function): Direct API functions. (line 29) * PyByteArray_Size (C function): Direct API functions. (line 19) * PyByteArray_Type (C variable): Byte Array Objects. (line 11) * PyBytesObject (C type): Bytes Objects<2>. (line 9) * PyBytes_AsString (C function): Bytes Objects<2>. (line 126) * PyBytes_AsStringAndSize (C function): Bytes Objects<2>. (line 143) * PyBytes_AS_STRING (C function): Bytes Objects<2>. (line 138) * PyBytes_Check (C function): Bytes Objects<2>. (line 20) * PyBytes_CheckExact (C function): Bytes Objects<2>. (line 25) * PyBytes_Concat (C function): Bytes Objects<2>. (line 165) * PyBytes_ConcatAndDel (C function): Bytes Objects<2>. (line 175) * PyBytes_FromFormat (C function): Bytes Objects<2>. (line 43) * PyBytes_FromFormatV (C function): Bytes Objects<2>. (line 106) * PyBytes_FromObject (C function): Bytes Objects<2>. (line 113) * PyBytes_FromString (C function): Bytes Objects<2>. (line 30) * PyBytes_FromStringAndSize (C function): Bytes Objects<2>. (line 35) * PyBytes_GET_SIZE (C function): Bytes Objects<2>. (line 121) * PyBytes_Size (C function): Bytes Objects<2>. (line 117) * PyBytes_Type (C variable): Bytes Objects<2>. (line 14) * pycache_prefix (in module sys): sys — System-specific parameters and functions. (line 288) * PyCallable_Check (C function): Object Protocol. (line 249) * PyCallIter_Check (C function): Iterator Objects. (line 34) * PyCallIter_New (C function): Iterator Objects. (line 38) * PyCallIter_Type (C variable): Iterator Objects. (line 28) * PyCapsule (C type): Capsules<2>. (line 11) * PyCapsule_CheckExact (C function): Capsules<2>. (line 29) * PyCapsule_Destructor (C type): Capsules<2>. (line 20) * PyCapsule_GetContext (C function): Capsules<2>. (line 76) * PyCapsule_GetDestructor (C function): Capsules<2>. (line 65) * PyCapsule_GetName (C function): Capsules<2>. (line 86) * PyCapsule_GetPointer (C function): Capsules<2>. (line 53) * PyCapsule_Import (C function): Capsules<2>. (line 96) * PyCapsule_IsValid (C function): Capsules<2>. (line 110) * PyCapsule_New (C function): Capsules<2>. (line 33) * PyCapsule_SetContext (C function): Capsules<2>. (line 126) * PyCapsule_SetDestructor (C function): Capsules<2>. (line 134) * PyCapsule_SetName (C function): Capsules<2>. (line 143) * PyCapsule_SetPointer (C function): Capsules<2>. (line 153) * PyCellObject (C type): Cell Objects. (line 16) * PyCell_Check (C function): Cell Objects. (line 24) * PyCell_Get (C function): Cell Objects. (line 32) * PyCell_GET (C function): Cell Objects. (line 36) * PyCell_New (C function): Cell Objects. (line 28) * PyCell_Set (C function): Cell Objects. (line 41) * PyCell_SET (C function): Cell Objects. (line 48) * PyCell_Type (C variable): Cell Objects. (line 20) * PyCFunction (C type): Common Object Structures. (line 95) * PyCFunctionWithKeywords (C type): Common Object Structures. (line 104) * PycInvalidationMode (class in py_compile): py_compile — Compile Python source files. (line 91) * pyclbr (module): pyclbr — Python module browser support. (line 6) * PyCodec_BackslashReplaceErrors (C function): Registry API for Unicode encoding error handlers. (line 50) * PyCodec_Decode (C function): Codec registry and support functions. (line 29) * PyCodec_Decoder (C function): Codec lookup API. (line 15) * PyCodec_Encode (C function): Codec registry and support functions. (line 19) * PyCodec_Encoder (C function): Codec lookup API. (line 11) * PyCodec_IgnoreErrors (C function): Registry API for Unicode encoding error handlers. (line 37) * PyCodec_IncrementalDecoder (C function): Codec lookup API. (line 24) * PyCodec_IncrementalEncoder (C function): Codec lookup API. (line 19) * PyCodec_KnownEncoding (C function): Codec registry and support functions. (line 14) * PyCodec_LookupError (C function): Registry API for Unicode encoding error handlers. (line 28) * PyCodec_NameReplaceErrors (C function): Registry API for Unicode encoding error handlers. (line 54) * PyCodec_Register (C function): Codec registry and support functions. (line 6) * PyCodec_RegisterError (C function): Registry API for Unicode encoding error handlers. (line 6) * PyCodec_ReplaceErrors (C function): Registry API for Unicode encoding error handlers. (line 41) * PyCodec_StreamReader (C function): Codec lookup API. (line 29) * PyCodec_StreamWriter (C function): Codec lookup API. (line 35) * PyCodec_StrictErrors (C function): Registry API for Unicode encoding error handlers. (line 34) * PyCodec_XMLCharRefReplaceErrors (C function): Registry API for Unicode encoding error handlers. (line 45) * PyCodeObject (C type): Code Objects<2>. (line 10) * PyCode_Check (C function): Code Objects<2>. (line 20) * PyCode_GetNumFree (C function): Code Objects<2>. (line 24) * PyCode_New (C function): Code Objects<2>. (line 28) * PyCode_NewEmpty (C function): Code Objects<2>. (line 56) * PyCode_NewWithPosOnlyArgs (C function): Code Objects<2>. (line 42) * PyCode_Type (C variable): Code Objects<2>. (line 15) * PyCompactUnicodeObject (C type): Unicode Type. (line 29) * PyCompileError: py_compile — Compile Python source files. (line 19) * PyCompilerFlags (C type): The Very High Level Layer. (line 396) * PyCompilerFlags.cf_feature_version (C member): The Very High Level Layer. (line 412) * PyCompilerFlags.cf_flags (C member): The Very High Level Layer. (line 408) * PyComplexObject (C type): Complex Numbers as Python Objects. (line 6) * PyComplex_AsCComplex (C function): Complex Numbers as Python Objects. (line 44) * PyComplex_Check (C function): Complex Numbers as Python Objects. (line 17) * PyComplex_CheckExact (C function): Complex Numbers as Python Objects. (line 22) * PyComplex_FromCComplex (C function): Complex Numbers as Python Objects. (line 27) * PyComplex_FromDoubles (C function): Complex Numbers as Python Objects. (line 31) * PyComplex_ImagAsDouble (C function): Complex Numbers as Python Objects. (line 40) * PyComplex_RealAsDouble (C function): Complex Numbers as Python Objects. (line 36) * PyComplex_Type (C variable): Complex Numbers as Python Objects. (line 11) * PyConfig (C type): PyConfig. (line 6) * PyConfig.argv (C member): PyConfig. (line 99) * PyConfig.base_executable (C member): PyConfig. (line 111) * PyConfig.base_exec_prefix (C member): PyConfig. (line 107) * PyConfig.base_prefix (C member): PyConfig. (line 116) * PyConfig.buffered_stdio (C member): PyConfig. (line 120) * PyConfig.bytes_warning (C member): PyConfig. (line 127) * PyConfig.check_hash_pycs_mode (C member): PyConfig. (line 134) * PyConfig.configure_c_stdio (C member): PyConfig. (line 144) * PyConfig.dev_mode (C member): PyConfig. (line 150) * PyConfig.dump_refs (C member): PyConfig. (line 154) * PyConfig.executable (C member): PyConfig. (line 165) * PyConfig.exec_prefix (C member): PyConfig. (line 161) * PyConfig.faulthandler (C member): PyConfig. (line 169) * PyConfig.filesystem_encoding (C member): PyConfig. (line 174) * PyConfig.filesystem_errors (C member): PyConfig. (line 178) * PyConfig.hash_seed (C member): PyConfig. (line 183) * PyConfig.home (C member): PyConfig. (line 193) * PyConfig.import_time (C member): PyConfig. (line 200) * PyConfig.inspect (C member): PyConfig. (line 204) * PyConfig.install_signal_handlers (C member): PyConfig. (line 208) * PyConfig.interactive (C member): PyConfig. (line 212) * PyConfig.isolated (C member): PyConfig. (line 216) * PyConfig.legacy_windows_stdio (C member): PyConfig. (line 230) * PyConfig.malloc_stats (C member): PyConfig. (line 239) * PyConfig.module_search_paths (C member): PyConfig. (line 255) * PyConfig.module_search_paths_set (C member): PyConfig. (line 257) * PyConfig.optimization_level (C member): PyConfig. (line 264) * PyConfig.parser_debug (C member): PyConfig. (line 280) * PyConfig.parse_argv (C member): PyConfig. (line 274) * PyConfig.pathconfig_warnings (C member): PyConfig. (line 285) * PyConfig.prefix (C member): PyConfig. (line 291) * PyConfig.program_name (C member): PyConfig. (line 295) * PyConfig.pycache_prefix (C member): PyConfig. (line 300) * PyConfig.pythonpath_env (C member): PyConfig. (line 247) * PyConfig.quiet (C member): PyConfig. (line 306) * PyConfig.run_command (C member): PyConfig. (line 311) * PyConfig.run_filename (C member): PyConfig. (line 316) * PyConfig.run_module (C member): PyConfig. (line 320) * PyConfig.show_alloc_count (C member): PyConfig. (line 325) * PyConfig.show_ref_count (C member): PyConfig. (line 333) * PyConfig.site_import (C member): PyConfig. (line 342) * PyConfig.skip_source_first_line (C member): PyConfig. (line 346) * PyConfig.stdio_encoding (C member): PyConfig. (line 350) * PyConfig.stdio_errors (C member): PyConfig. (line 352) * PyConfig.tracemalloc (C member): PyConfig. (line 357) * PyConfig.user_site_directory (C member): PyConfig. (line 365) * PyConfig.use_environment (C member): PyConfig. (line 361) * PyConfig.use_hash_seed (C member): PyConfig. (line 185) * PyConfig.verbose (C member): PyConfig. (line 369) * PyConfig.warnoptions (C member): PyConfig. (line 373) * PyConfig.write_bytecode (C member): PyConfig. (line 384) * PyConfig.xoptions (C member): PyConfig. (line 391) * PyConfig_Clear (C function): PyConfig. (line 69) * PyConfig_InitIsolatedConfig (C function): PyConfig. (line 17) * PyConfig_InitPythonConfig (C function): PyConfig. (line 12) * PyConfig_Read (C function): PyConfig. (line 61) * PyConfig_SetArgv (C function): PyConfig. (line 37) * PyConfig_SetBytesArgv (C function): PyConfig. (line 44) * PyConfig_SetBytesString (C function): PyConfig. (line 29) * PyConfig_SetString (C function): PyConfig. (line 22) * PyConfig_SetWideStringList (C function): PyConfig. (line 53) * PyContext (C type): Context Variables Objects. (line 24) * PyContextToken (C type): Context Variables Objects. (line 34) * PyContextToken_CheckExact (C function): Context Variables Objects. (line 62) * PyContextToken_Type (C variable): Context Variables Objects. (line 46) * PyContextVar (C type): Context Variables Objects. (line 29) * PyContextVar_CheckExact (C function): Context Variables Objects. (line 57) * PyContextVar_Get (C function): Context Variables Objects. (line 107) * PyContextVar_New (C function): Context Variables Objects. (line 99) * PyContextVar_Reset (C function): Context Variables Objects. (line 132) * PyContextVar_Set (C function): Context Variables Objects. (line 126) * PyContextVar_Type (C variable): Context Variables Objects. (line 42) * PyContext_CheckExact (C function): Context Variables Objects. (line 52) * PyContext_ClearFreeList (C function): Context Variables Objects. (line 92) * PyContext_Copy (C function): Context Variables Objects. (line 73) * PyContext_CopyCurrent (C function): Context Variables Objects. (line 77) * PyContext_Enter (C function): Context Variables Objects. (line 81) * PyContext_Exit (C function): Context Variables Objects. (line 86) * PyContext_New (C function): Context Variables Objects. (line 69) * PyContext_Type (C variable): Context Variables Objects. (line 38) * PyCoroObject (C type): Coroutine Objects<2>. (line 11) * PyCoro_CheckExact (C function): Coroutine Objects<2>. (line 19) * PyCoro_New (C function): Coroutine Objects<2>. (line 24) * PyCoro_Type (C variable): Coroutine Objects<2>. (line 15) * PyDateTime_Check (C function): DateTime Objects<2>. (line 35) * PyDateTime_CheckExact (C function): DateTime Objects<2>. (line 40) * PyDateTime_DATE_GET_HOUR (C function): DateTime Objects<2>. (line 158) * PyDateTime_DATE_GET_MICROSECOND (C function): DateTime Objects<2>. (line 170) * PyDateTime_DATE_GET_MINUTE (C function): DateTime Objects<2>. (line 162) * PyDateTime_DATE_GET_SECOND (C function): DateTime Objects<2>. (line 166) * PyDateTime_DELTA_GET_DAYS (C function): DateTime Objects<2>. (line 200) * PyDateTime_DELTA_GET_MICROSECONDS (C function): DateTime Objects<2>. (line 212) * PyDateTime_DELTA_GET_SECONDS (C function): DateTime Objects<2>. (line 206) * PyDateTime_FromDateAndTime (C function): DateTime Objects<2>. (line 81) * PyDateTime_FromDateAndTimeAndFold (C function): DateTime Objects<2>. (line 88) * PyDateTime_FromTimestamp (C function): DateTime Objects<2>. (line 221) * PyDateTime_GET_DAY (C function): DateTime Objects<2>. (line 150) * PyDateTime_GET_MONTH (C function): DateTime Objects<2>. (line 146) * PyDateTime_GET_YEAR (C function): DateTime Objects<2>. (line 142) * PyDateTime_TimeZone_UTC (C variable): DateTime Objects<2>. (line 16) * PyDateTime_TIME_GET_HOUR (C function): DateTime Objects<2>. (line 180) * PyDateTime_TIME_GET_MICROSECOND (C function): DateTime Objects<2>. (line 192) * PyDateTime_TIME_GET_MINUTE (C function): DateTime Objects<2>. (line 184) * PyDateTime_TIME_GET_SECOND (C function): DateTime Objects<2>. (line 188) * PyDate_Check (C function): DateTime Objects<2>. (line 25) * PyDate_CheckExact (C function): DateTime Objects<2>. (line 30) * PyDate_FromDate (C function): DateTime Objects<2>. (line 77) * PyDate_FromTimestamp (C function): DateTime Objects<2>. (line 226) * PyDelta_Check (C function): DateTime Objects<2>. (line 55) * PyDelta_CheckExact (C function): DateTime Objects<2>. (line 60) * PyDelta_FromDSU (C function): DateTime Objects<2>. (line 112) * PyDescr_IsData (C function): Descriptor Objects. (line 37) * PyDescr_NewClassMethod (C function): Descriptor Objects. (line 32) * PyDescr_NewGetSet (C function): Descriptor Objects. (line 13) * PyDescr_NewMember (C function): Descriptor Objects. (line 18) * PyDescr_NewMethod (C function): Descriptor Objects. (line 23) * PyDescr_NewWrapper (C function): Descriptor Objects. (line 28) * PyDictObject (C type): Dictionary Objects. (line 6) * PyDictProxy_New (C function): Dictionary Objects. (line 31) * PyDict_Check (C function): Dictionary Objects. (line 17) * PyDict_CheckExact (C function): Dictionary Objects. (line 22) * PyDict_Clear (C function): Dictionary Objects. (line 37) * PyDict_ClearFreeList (C function): Dictionary Objects. (line 223) * PyDict_Contains (C function): Dictionary Objects. (line 41) * PyDict_Copy (C function): Dictionary Objects. (line 47) * PyDict_DelItem (C function): Dictionary Objects. (line 69) * PyDict_DelItemString (C function): Dictionary Objects. (line 76) * PyDict_GetItem (C function): Dictionary Objects. (line 82) * PyDict_GetItemString (C function): Dictionary Objects. (line 99) * PyDict_GetItemWithError (C function): Dictionary Objects. (line 91) * PyDict_Items (C function): Dictionary Objects. (line 122) * PyDict_Keys (C function): Dictionary Objects. (line 126) * PyDict_Merge (C function): Dictionary Objects. (line 188) * PyDict_MergeFromSeq2 (C function): Dictionary Objects. (line 207) * PyDict_New (C function): Dictionary Objects. (line 27) * PyDict_Next (C function): Dictionary Objects. (line 139) * PyDict_SetDefault (C function): Dictionary Objects. (line 110) * PyDict_SetItem (C function): Dictionary Objects. (line 51) * PyDict_SetItemString (C function): Dictionary Objects. (line 60) * PyDict_Size (C function): Dictionary Objects. (line 134) * PyDict_Type (C variable): Dictionary Objects. (line 11) * PyDict_Update (C function): Dictionary Objects. (line 199) * PyDict_Values (C function): Dictionary Objects. (line 130) * PyDLL (class in ctypes): Loading shared libraries. (line 61) * pydoc (module): pydoc — Documentation generator and online help system. (line 6) * PyDoc_STR (C macro): Useful macros. (line 99) * PyDoc_STRVAR (C macro): Useful macros. (line 81) * PyErr_BadArgument (C function): Raising exceptions. (line 46) * PyErr_BadInternalCall (C function): Raising exceptions. (line 197) * PyErr_CheckSignals (C function): Signal Handling<2>. (line 6) * PyErr_Clear (C function): Printing and clearing. (line 6) * PyErr_Clear(): Exceptions<18>. (line 25) * PyErr_Clear() <1>: Exceptions<18>. (line 123) * PyErr_ExceptionMatches (C function): Querying the error indicator. (line 20) * PyErr_ExceptionMatches(): Exceptions<18>. (line 123) * PyErr_Fetch (C function): Querying the error indicator. (line 36) * PyErr_Fetch(): Finalization and De-allocation. (line 21) * PyErr_Format (C function): Raising exceptions. (line 25) * PyErr_FormatV (C function): Raising exceptions. (line 33) * PyErr_GetExcInfo (C function): Querying the error indicator. (line 97) * PyErr_GivenExceptionMatches (C function): Querying the error indicator. (line 26) * PyErr_NewException (C function): Exception Classes. (line 6) * PyErr_NewExceptionWithDoc (C function): Exception Classes. (line 24) * PyErr_NoMemory (C function): Raising exceptions. (line 52) * PyErr_NormalizeException (C function): Querying the error indicator. (line 78) * PyErr_Occurred (C function): Querying the error indicator. (line 6) * PyErr_Occurred(): Exceptions<18>. (line 12) * PyErr_Print (C function): Printing and clearing. (line 26) * PyErr_PrintEx (C function): Printing and clearing. (line 11) * PyErr_ResourceWarning (C function): Issuing warnings. (line 80) * PyErr_Restore (C function): Querying the error indicator. (line 59) * PyErr_Restore(): Finalization and De-allocation. (line 21) * PyErr_SetExcFromWindowsErr (C function): Raising exceptions. (line 114) * PyErr_SetExcFromWindowsErrWithFilename (C function): Raising exceptions. (line 152) * PyErr_SetExcFromWindowsErrWithFilenameObject (C function): Raising exceptions. (line 132) * PyErr_SetExcFromWindowsErrWithFilenameObjects (C function): Raising exceptions. (line 141) * PyErr_SetExcInfo (C function): Querying the error indicator. (line 114) * PyErr_SetFromErrno (C function): Raising exceptions. (line 58) * PyErr_SetFromErrnoWithFilename (C function): Raising exceptions. (line 93) * PyErr_SetFromErrnoWithFilenameObject (C function): Raising exceptions. (line 73) * PyErr_SetFromErrnoWithFilenameObjects (C function): Raising exceptions. (line 82) * PyErr_SetFromWindowsErr (C function): Raising exceptions. (line 100) * PyErr_SetFromWindowsErrWithFilename (C function): Raising exceptions. (line 123) * PyErr_SetImportError (C function): Raising exceptions. (line 161) * PyErr_SetImportErrorSubclass (C function): Issuing warnings. (line 41) * PyErr_SetInterrupt (C function): Signal Handling<2>. (line 18) * PyErr_SetNone (C function): Raising exceptions. (line 42) * PyErr_SetObject (C function): Raising exceptions. (line 19) * PyErr_SetString (C function): Raising exceptions. (line 10) * PyErr_SetString(): Exceptions<18>. (line 25) * PyErr_SyntaxLocation (C function): Raising exceptions. (line 191) * PyErr_SyntaxLocationEx (C function): Raising exceptions. (line 182) * PyErr_SyntaxLocationObject (C function): Raising exceptions. (line 171) * PyErr_WarnEx (C function): Issuing warnings. (line 19) * PyErr_WarnExplicit (C function): Issuing warnings. (line 63) * PyErr_WarnExplicitObject (C function): Issuing warnings. (line 50) * PyErr_WarnFormat (C function): Issuing warnings. (line 71) * PyErr_WriteUnraisable (C function): Printing and clearing. (line 30) * PyEval_AcquireLock (C function): Low-level API. (line 137) * PyEval_AcquireThread (C function): Low-level API. (line 104) * PyEval_AcquireThread(): High-level API. (line 29) * PyEval_EvalCode (C function): The Very High Level Layer. (line 329) * PyEval_EvalCodeEx (C function): The Very High Level Layer. (line 335) * PyEval_EvalFrame (C function): The Very High Level Layer. (line 354) * PyEval_EvalFrameEx (C function): The Very High Level Layer. (line 359) * PyEval_GetBuiltins (C function): Reflection. (line 6) * PyEval_GetFrame (C function): Reflection. (line 21) * PyEval_GetFuncDesc (C function): Reflection. (line 34) * PyEval_GetFuncName (C function): Reflection. (line 29) * PyEval_GetGlobals (C function): Reflection. (line 16) * PyEval_GetLocals (C function): Reflection. (line 11) * PyEval_InitThreads (C function): High-level API. (line 27) * PyEval_InitThreads(): Initializing and finalizing the interpreter. (line 8) * PyEval_MergeCompilerFlags (C function): The Very High Level Layer. (line 373) * PyEval_ReleaseLock (C function): Low-level API. (line 159) * PyEval_ReleaseThread (C function): Low-level API. (line 126) * PyEval_ReleaseThread(): High-level API. (line 29) * PyEval_RestoreThread (C function): High-level API. (line 62) * PyEval_RestoreThread(): Releasing the GIL from extension code. (line 33) * PyEval_RestoreThread() <1>: High-level API. (line 29) * PyEval_SaveThread (C function): High-level API. (line 55) * PyEval_SaveThread(): Releasing the GIL from extension code. (line 33) * PyEval_SaveThread() <1>: High-level API. (line 29) * PyEval_SetProfile (C function): Profiling and Tracing. (line 116) * PyEval_SetTrace (C function): Profiling and Tracing. (line 127) * PyEval_ThreadsInitialized (C function): High-level API. (line 45) * PyException_GetCause (C function): Exception Objects. (line 32) * PyException_GetContext (C function): Exception Objects. (line 18) * PyException_GetTraceback (C function): Exception Objects. (line 6) * PyException_SetCause (C function): Exception Objects. (line 38) * PyException_SetContext (C function): Exception Objects. (line 25) * PyException_SetTraceback (C function): Exception Objects. (line 12) * PyExc_ArithmeticError: Standard Exceptions. (line 11) * PyExc_AssertionError: Standard Exceptions. (line 11) * PyExc_AttributeError: Standard Exceptions. (line 11) * PyExc_BaseException: Standard Exceptions. (line 11) * PyExc_BlockingIOError: Standard Exceptions. (line 11) * PyExc_BrokenPipeError: Standard Exceptions. (line 11) * PyExc_BufferError: Standard Exceptions. (line 11) * PyExc_BytesWarning: Standard Warning Categories. (line 11) * PyExc_ChildProcessError: Standard Exceptions. (line 11) * PyExc_ConnectionAbortedError: Standard Exceptions. (line 11) * PyExc_ConnectionError: Standard Exceptions. (line 11) * PyExc_ConnectionRefusedError: Standard Exceptions. (line 11) * PyExc_ConnectionResetError: Standard Exceptions. (line 11) * PyExc_DeprecationWarning: Standard Warning Categories. (line 11) * PyExc_EnvironmentError: Standard Exceptions. (line 190) * PyExc_EOFError: Standard Exceptions. (line 11) * PyExc_Exception: Standard Exceptions. (line 11) * PyExc_FileExistsError: Standard Exceptions. (line 11) * PyExc_FileNotFoundError: Standard Exceptions. (line 11) * PyExc_FloatingPointError: Standard Exceptions. (line 11) * PyExc_FutureWarning: Standard Warning Categories. (line 11) * PyExc_GeneratorExit: Standard Exceptions. (line 11) * PyExc_ImportError: Standard Exceptions. (line 11) * PyExc_ImportWarning: Standard Warning Categories. (line 11) * PyExc_IndentationError: Standard Exceptions. (line 11) * PyExc_IndexError: Standard Exceptions. (line 11) * PyExc_InterruptedError: Standard Exceptions. (line 11) * PyExc_IOError: Standard Exceptions. (line 190) * PyExc_IsADirectoryError: Standard Exceptions. (line 11) * PyExc_KeyboardInterrupt: Standard Exceptions. (line 11) * PyExc_KeyError: Standard Exceptions. (line 11) * PyExc_LookupError: Standard Exceptions. (line 11) * PyExc_MemoryError: Standard Exceptions. (line 11) * PyExc_ModuleNotFoundError: Standard Exceptions. (line 11) * PyExc_NameError: Standard Exceptions. (line 11) * PyExc_NotADirectoryError: Standard Exceptions. (line 11) * PyExc_NotImplementedError: Standard Exceptions. (line 11) * PyExc_OSError: Standard Exceptions. (line 11) * PyExc_OverflowError: Standard Exceptions. (line 11) * PyExc_PendingDeprecationWarning: Standard Warning Categories. (line 11) * PyExc_PermissionError: Standard Exceptions. (line 11) * PyExc_ProcessLookupError: Standard Exceptions. (line 11) * PyExc_RecursionError: Standard Exceptions. (line 11) * PyExc_ReferenceError: Standard Exceptions. (line 11) * PyExc_ResourceWarning: Standard Warning Categories. (line 11) * PyExc_RuntimeError: Standard Exceptions. (line 11) * PyExc_RuntimeWarning: Standard Warning Categories. (line 11) * PyExc_StopAsyncIteration: Standard Exceptions. (line 11) * PyExc_StopIteration: Standard Exceptions. (line 11) * PyExc_SyntaxError: Standard Exceptions. (line 11) * PyExc_SyntaxWarning: Standard Warning Categories. (line 11) * PyExc_SystemError: Standard Exceptions. (line 11) * PyExc_SystemExit: Standard Exceptions. (line 11) * PyExc_TabError: Standard Exceptions. (line 11) * PyExc_TimeoutError: Standard Exceptions. (line 11) * PyExc_TypeError: Standard Exceptions. (line 11) * PyExc_UnboundLocalError: Standard Exceptions. (line 11) * PyExc_UnicodeDecodeError: Standard Exceptions. (line 11) * PyExc_UnicodeEncodeError: Standard Exceptions. (line 11) * PyExc_UnicodeError: Standard Exceptions. (line 11) * PyExc_UnicodeTranslateError: Standard Exceptions. (line 11) * PyExc_UnicodeWarning: Standard Warning Categories. (line 11) * PyExc_UserWarning: Standard Warning Categories. (line 11) * PyExc_ValueError: Standard Exceptions. (line 11) * PyExc_Warning: Standard Warning Categories. (line 11) * PyExc_WindowsError: Standard Exceptions. (line 190) * PyExc_ZeroDivisionError: Standard Exceptions. (line 11) * PyFile_FromFd (C function): File Objects. (line 15) * PyFile_GetLine (C function): File Objects. (line 40) * PyFile_SetOpenCodeHook (C function): File Objects. (line 54) * PyFile_WriteObject (C function): File Objects. (line 84) * PyFile_WriteString (C function): File Objects. (line 92) * PyFloatObject (C type): Floating Point Objects. (line 6) * PyFloat_AsDouble (C function): Floating Point Objects. (line 35) * PyFloat_AS_DOUBLE (C function): Floating Point Objects. (line 47) * PyFloat_Check (C function): Floating Point Objects. (line 17) * PyFloat_CheckExact (C function): Floating Point Objects. (line 22) * PyFloat_ClearFreeList (C function): Floating Point Objects. (line 68) * PyFloat_FromDouble (C function): Floating Point Objects. (line 31) * PyFloat_FromString (C function): Floating Point Objects. (line 27) * PyFloat_GetInfo (C function): Floating Point Objects. (line 52) * PyFloat_GetMax (C function): Floating Point Objects. (line 58) * PyFloat_GetMin (C function): Floating Point Objects. (line 63) * PyFloat_Type (C variable): Floating Point Objects. (line 11) * PyFrameObject (C type): The Very High Level Layer. (line 349) * PyFrame_GetLineNumber (C function): Reflection. (line 25) * PyFrozenSet_Check (C function): Set Objects. (line 50) * PyFrozenSet_CheckExact (C function): Set Objects. (line 65) * PyFrozenSet_New (C function): Set Objects. (line 78) * PyFrozenSet_Type (C variable): Set Objects. (line 36) * PyFunctionObject (C type): Function Objects<3>. (line 8) * PyFunction_Check (C function): Function Objects<3>. (line 18) * PyFunction_GetAnnotations (C function): Function Objects<3>. (line 85) * PyFunction_GetClosure (C function): Function Objects<3>. (line 72) * PyFunction_GetCode (C function): Function Objects<3>. (line 45) * PyFunction_GetDefaults (C function): Function Objects<3>. (line 59) * PyFunction_GetGlobals (C function): Function Objects<3>. (line 49) * PyFunction_GetModule (C function): Function Objects<3>. (line 53) * PyFunction_New (C function): Function Objects<3>. (line 23) * PyFunction_NewWithQualName (C function): Function Objects<3>. (line 34) * PyFunction_SetAnnotations (C function): Function Objects<3>. (line 89) * PyFunction_SetClosure (C function): Function Objects<3>. (line 77) * PyFunction_SetDefaults (C function): Function Objects<3>. (line 64) * PyFunction_Type (C variable): Function Objects<3>. (line 12) * PYFUNCTYPE() (in module ctypes): Function prototypes. (line 34) * PyGenObject (C type): Generator Objects. (line 11) * PyGen_Check (C function): Generator Objects. (line 19) * PyGen_CheckExact (C function): Generator Objects. (line 23) * PyGen_New (C function): Generator Objects. (line 28) * PyGen_NewWithQualName (C function): Generator Objects. (line 33) * PyGen_Type (C variable): Generator Objects. (line 15) * PyGetSetDef (C type): Common Object Structures. (line 358) * PyGILState_Check (C function): High-level API. (line 142) * PyGILState_Ensure (C function): High-level API. (line 92) * PyGILState_GetThisThreadState (C function): High-level API. (line 134) * PyGILState_Release (C function): High-level API. (line 123) * PyImport_AddModule (C function): Importing Modules<2>. (line 111) * PyImport_AddModuleObject (C function): Importing Modules<2>. (line 95) * PyImport_AppendInittab (C function): Importing Modules<2>. (line 281) * PyImport_Cleanup (C function): Importing Modules<2>. (line 234) * PyImport_ExecCodeModule (C function): Importing Modules<2>. (line 116) * PyImport_ExecCodeModuleEx (C function): Importing Modules<2>. (line 152) * PyImport_ExecCodeModuleObject (C function): Importing Modules<2>. (line 162) * PyImport_ExecCodeModuleWithPathnames (C function): Importing Modules<2>. (line 172) * PyImport_ExtendInittab (C function): Importing Modules<2>. (line 307) * PyImport_FrozenModules (C variable): Importing Modules<2>. (line 273) * PyImport_GetImporter (C function): Importing Modules<2>. (line 219) * PyImport_GetMagicNumber (C function): Importing Modules<2>. (line 188) * PyImport_GetMagicTag (C function): Importing Modules<2>. (line 197) * PyImport_GetModule (C function): Importing Modules<2>. (line 211) * PyImport_GetModuleDict (C function): Importing Modules<2>. (line 206) * PyImport_Import (C function): Importing Modules<2>. (line 80) * PyImport_ImportFrozenModule (C function): Importing Modules<2>. (line 255) * PyImport_ImportFrozenModuleObject (C function): Importing Modules<2>. (line 242) * PyImport_ImportModule (C function): Importing Modules<2>. (line 6) * PyImport_ImportModuleEx (C function): Importing Modules<2>. (line 35) * PyImport_ImportModuleLevel (C function): Importing Modules<2>. (line 69) * PyImport_ImportModuleLevelObject (C function): Importing Modules<2>. (line 52) * PyImport_ImportModuleNoBlock (C function): Importing Modules<2>. (line 25) * PyImport_ReloadModule (C function): Importing Modules<2>. (line 90) * PyIndex_Check (C function): Number Protocol. (line 272) * PyInit_modulename (C function): Building C and C++ Extensions. (line 16) * PyInstanceMethod_Check (C function): Instance Method Objects. (line 15) * PyInstanceMethod_Function (C function): Instance Method Objects. (line 25) * PyInstanceMethod_GET_FUNCTION (C function): Instance Method Objects. (line 29) * PyInstanceMethod_New (C function): Instance Method Objects. (line 20) * PyInstanceMethod_Type (C variable): Instance Method Objects. (line 10) * PyInterpreterState (C type): High-level API. (line 9) * PyInterpreterState_Clear (C function): Low-level API. (line 21) * PyInterpreterState_Delete (C function): Low-level API. (line 30) * PyInterpreterState_GetDict (C function): Low-level API. (line 63) * PyInterpreterState_GetID (C function): Low-level API. (line 55) * PyInterpreterState_Head (C function): Advanced Debugger Support. (line 9) * PyInterpreterState_Main (C function): Advanced Debugger Support. (line 14) * PyInterpreterState_New (C function): Low-level API. (line 12) * PyInterpreterState_Next (C function): Advanced Debugger Support. (line 18) * PyInterpreterState_ThreadHead (C function): Advanced Debugger Support. (line 25) * PyIter_Check (C function): Iterator Protocol. (line 8) * PyIter_Next (C function): Iterator Protocol. (line 12) * PyListObject (C type): List Objects. (line 6) * PyList_Append (C function): List Objects. (line 91) * PyList_AsTuple (C function): List Objects. (line 125) * PyList_Check (C function): List Objects. (line 17) * PyList_CheckExact (C function): List Objects. (line 22) * PyList_ClearFreeList (C function): List Objects. (line 131) * PyList_GetItem (C function): List Objects. (line 46) * PyList_GetItem(): Reference Count Details. (line 117) * PyList_GetSlice (C function): List Objects. (line 97) * PyList_GET_ITEM (C function): List Objects. (line 54) * PyList_GET_SIZE (C function): List Objects. (line 42) * PyList_Insert (C function): List Objects. (line 83) * PyList_New (C function): List Objects. (line 27) * PyList_Reverse (C function): List Objects. (line 120) * PyList_SetItem (C function): List Objects. (line 58) * PyList_SetItem(): Reference Count Details. (line 26) * PyList_SetSlice (C function): List Objects. (line 105) * PyList_SET_ITEM (C function): List Objects. (line 70) * PyList_Size (C function): List Objects. (line 37) * PyList_Sort (C function): List Objects. (line 115) * PyList_Type (C variable): List Objects. (line 11) * PyLongObject (C type): Integer Objects. (line 13) * PyLong_AsDouble (C function): Integer Objects. (line 272) * PyLong_AsLong (C function): Integer Objects. (line 105) * PyLong_AsLongAndOverflow (C function): Integer Objects. (line 123) * PyLong_AsLongLong (C function): Integer Objects. (line 144) * PyLong_AsLongLongAndOverflow (C function): Integer Objects. (line 162) * PyLong_AsSize_t (C function): Integer Objects. (line 208) * PyLong_AsSsize_t (C function): Integer Objects. (line 186) * PyLong_AsUnsignedLong (C function): Integer Objects. (line 197) * PyLong_AsUnsignedLongLong (C function): Integer Objects. (line 219) * PyLong_AsUnsignedLongLongMask (C function): Integer Objects. (line 252) * PyLong_AsUnsignedLongMask (C function): Integer Objects. (line 234) * PyLong_AsVoidPtr (C function): Integer Objects. (line 283) * PyLong_Check (C function): Integer Objects. (line 24) * PyLong_CheckExact (C function): Integer Objects. (line 29) * PyLong_FromDouble (C function): Integer Objects. (line 66) * PyLong_FromLong (C function): Integer Objects. (line 34) * PyLong_FromLongLong (C function): Integer Objects. (line 56) * PyLong_FromSize_t (C function): Integer Objects. (line 52) * PyLong_FromSsize_t (C function): Integer Objects. (line 48) * PyLong_FromString (C function): Integer Objects. (line 70) * PyLong_FromUnicode (C function): Integer Objects. (line 84) * PyLong_FromUnicodeObject (C function): Integer Objects. (line 93) * PyLong_FromUnsignedLong (C function): Integer Objects. (line 44) * PyLong_FromUnsignedLongLong (C function): Integer Objects. (line 60) * PyLong_FromVoidPtr (C function): Integer Objects. (line 100) * PyLong_Type (C variable): Integer Objects. (line 18) * PyMappingMethods (C type): Mapping Object Structures. (line 6) * PyMappingMethods.mp_ass_subscript (C member): Mapping Object Structures. (line 25) * PyMappingMethods.mp_length (C member): Mapping Object Structures. (line 11) * PyMappingMethods.mp_subscript (C member): Mapping Object Structures. (line 17) * PyMapping_Check (C function): Mapping Protocol. (line 9) * PyMapping_DelItem (C function): Mapping Protocol. (line 39) * PyMapping_DelItemString (C function): Mapping Protocol. (line 45) * PyMapping_GetItemString (C function): Mapping Protocol. (line 23) * PyMapping_HasKey (C function): Mapping Protocol. (line 52) * PyMapping_HasKeyString (C function): Mapping Protocol. (line 62) * PyMapping_Items (C function): Mapping Protocol. (line 88) * PyMapping_Keys (C function): Mapping Protocol. (line 74) * PyMapping_Length (C function): Mapping Protocol. (line 17) * PyMapping_SetItemString (C function): Mapping Protocol. (line 31) * PyMapping_Size (C function): Mapping Protocol. (line 17) * PyMapping_Values (C function): Mapping Protocol. (line 81) * PyMarshal_ReadLastObjectFromFile (C function): Data marshalling support. (line 68) * PyMarshal_ReadLongFromFile (C function): Data marshalling support. (line 42) * PyMarshal_ReadObjectFromFile (C function): Data marshalling support. (line 60) * PyMarshal_ReadObjectFromString (C function): Data marshalling support. (line 83) * PyMarshal_ReadShortFromFile (C function): Data marshalling support. (line 51) * PyMarshal_WriteLongToFile (C function): Data marshalling support. (line 20) * PyMarshal_WriteObjectToFile (C function): Data marshalling support. (line 28) * PyMarshal_WriteObjectToString (C function): Data marshalling support. (line 34) * PyMemAllocatorDomain (C type): Customize Memory Allocators. (line 36) * PyMemAllocatorEx (C type): Customize Memory Allocators. (line 8) * PyMemberDef (C type): Common Object Structures. (line 255) * PyMemoryView_Check (C function): MemoryView objects. (line 41) * PyMemoryView_FromBuffer (C function): MemoryView objects. (line 26) * PyMemoryView_FromMemory (C function): MemoryView objects. (line 17) * PyMemoryView_FromObject (C function): MemoryView objects. (line 10) * PyMemoryView_GetContiguous (C function): MemoryView objects. (line 31) * PyMemoryView_GET_BASE (C function): MemoryView objects. (line 53) * PyMemoryView_GET_BUFFER (C function): MemoryView objects. (line 46) * PyMem_Calloc (C function): Memory Interface. (line 28) * PyMem_Del (C function): Memory Interface. (line 86) * PYMEM_DOMAIN_MEM (C macro): Customize Memory Allocators. (line 52) * PYMEM_DOMAIN_OBJ (C macro): Customize Memory Allocators. (line 64) * PYMEM_DOMAIN_RAW (C macro): Customize Memory Allocators. (line 40) * PyMem_Free (C function): Memory Interface. (line 57) * PyMem_GetAllocator (C function): Customize Memory Allocators. (line 76) * PyMem_Malloc (C function): Memory Interface. (line 19) * PyMem_New (C function): Memory Interface. (line 70) * PyMem_RawCalloc (C function): Raw Memory Interface. (line 24) * PyMem_RawFree (C function): Raw Memory Interface. (line 53) * PyMem_RawMalloc (C function): Raw Memory Interface. (line 15) * PyMem_RawRealloc (C function): Raw Memory Interface. (line 36) * PyMem_Realloc (C function): Memory Interface. (line 40) * PyMem_Resize (C function): Memory Interface. (line 76) * PyMem_SetAllocator (C function): Customize Memory Allocators. (line 82) * PyMem_SetupDebugHooks (C function): Customize Memory Allocators. (line 99) * PyMethodDef (C type): Common Object Structures. (line 119) * PyMethod_Check (C function): Method Objects<2>. (line 16) * PyMethod_ClearFreeList (C function): Method Objects<2>. (line 43) * PyMethod_Function (C function): Method Objects<2>. (line 27) * PyMethod_GET_FUNCTION (C function): Method Objects<2>. (line 31) * PyMethod_GET_SELF (C function): Method Objects<2>. (line 39) * PyMethod_New (C function): Method Objects<2>. (line 21) * PyMethod_Self (C function): Method Objects<2>. (line 35) * PyMethod_Type (C variable): Method Objects<2>. (line 10) * PyModuleDef (C type): Initializing C modules. (line 17) * PyModuleDef.m_base (C member): Initializing C modules. (line 23) * PyModuleDef.m_clear (C member): Initializing C modules. (line 82) * PyModuleDef.m_doc (C member): Initializing C modules. (line 31) * PyModuleDef.m_free (C member): Initializing C modules. (line 90) * PyModuleDef.m_methods (C member): Initializing C modules. (line 57) * PyModuleDef.m_name (C member): Initializing C modules. (line 27) * PyModuleDef.m_reload (C member): Initializing C modules. (line 72) * PyModuleDef.m_size (C member): Initializing C modules. (line 36) * PyModuleDef.m_slots (C member): Initializing C modules. (line 63) * PyModuleDef.m_traverse (C member): Initializing C modules. (line 74) * PyModuleDef_Init (C function): Multi-phase initialization. (line 33) * PyModuleDef_Slot (C type): Multi-phase initialization. (line 45) * PyModuleDef_Slot.slot (C member): Multi-phase initialization. (line 47) * PyModuleDef_Slot.value (C member): Multi-phase initialization. (line 51) * PyModule_AddFunctions (C function): Low-level module creation functions. (line 53) * PyModule_AddIntConstant (C function): Support functions. (line 34) * PyModule_AddIntMacro (C function): Support functions. (line 51) * PyModule_AddObject (C function): Support functions. (line 11) * PyModule_AddStringConstant (C function): Support functions. (line 42) * PyModule_AddStringMacro (C function): Support functions. (line 58) * PyModule_Check (C function): Module Objects. (line 12) * PyModule_CheckExact (C function): Module Objects. (line 17) * PyModule_Create (C function): Single-phase initialization. (line 10) * PyModule_Create2 (C function): Single-phase initialization. (line 16) * PyModule_ExecDef (C function): Low-level module creation functions. (line 36) * PyModule_FromDefAndSpec (C function): Low-level module creation functions. (line 11) * PyModule_FromDefAndSpec2 (C function): Low-level module creation functions. (line 21) * PyModule_GetDef (C function): Module Objects. (line 74) * PyModule_GetDict (C function): Module Objects. (line 41) * PyModule_GetFilename (C function): Module Objects. (line 91) * PyModule_GetFilenameObject (C function): Module Objects. (line 80) * PyModule_GetName (C function): Module Objects. (line 63) * PyModule_GetNameObject (C function): Module Objects. (line 54) * PyModule_GetState (C function): Module Objects. (line 68) * PyModule_New (C function): Module Objects. (line 36) * PyModule_NewObject (C function): Module Objects. (line 22) * PyModule_SetDocString (C function): Low-level module creation functions. (line 44) * PyModule_Type (C variable): Module Objects. (line 6) * PyNumberMethods (C type): Number Object Structures. (line 6) * PyNumberMethods.nb_absolute (C member): Number Object Structures. (line 85) * PyNumberMethods.nb_add (C member): Number Object Structures. (line 69) * PyNumberMethods.nb_and (C member): Number Object Structures. (line 95) * PyNumberMethods.nb_bool (C member): Number Object Structures. (line 87) * PyNumberMethods.nb_divmod (C member): Number Object Structures. (line 77) * PyNumberMethods.nb_float (C member): Number Object Structures. (line 105) * PyNumberMethods.nb_floor_divide (C member): Number Object Structures. (line 127) * PyNumberMethods.nb_index (C member): Number Object Structures. (line 135) * PyNumberMethods.nb_inplace_add (C member): Number Object Structures. (line 107) * PyNumberMethods.nb_inplace_and (C member): Number Object Structures. (line 121) * PyNumberMethods.nb_inplace_floor_divide (C member): Number Object Structures. (line 131) * PyNumberMethods.nb_inplace_lshift (C member): Number Object Structures. (line 117) * PyNumberMethods.nb_inplace_matrix_multiply (C member): Number Object Structures. (line 139) * PyNumberMethods.nb_inplace_multiply (C member): Number Object Structures. (line 111) * PyNumberMethods.nb_inplace_or (C member): Number Object Structures. (line 125) * PyNumberMethods.nb_inplace_power (C member): Number Object Structures. (line 115) * PyNumberMethods.nb_inplace_remainder (C member): Number Object Structures. (line 113) * PyNumberMethods.nb_inplace_rshift (C member): Number Object Structures. (line 119) * PyNumberMethods.nb_inplace_subtract (C member): Number Object Structures. (line 109) * PyNumberMethods.nb_inplace_true_divide (C member): Number Object Structures. (line 133) * PyNumberMethods.nb_inplace_xor (C member): Number Object Structures. (line 123) * PyNumberMethods.nb_int (C member): Number Object Structures. (line 101) * PyNumberMethods.nb_invert (C member): Number Object Structures. (line 89) * PyNumberMethods.nb_lshift (C member): Number Object Structures. (line 91) * PyNumberMethods.nb_matrix_multiply (C member): Number Object Structures. (line 137) * PyNumberMethods.nb_multiply (C member): Number Object Structures. (line 73) * PyNumberMethods.nb_negative (C member): Number Object Structures. (line 81) * PyNumberMethods.nb_or (C member): Number Object Structures. (line 99) * PyNumberMethods.nb_positive (C member): Number Object Structures. (line 83) * PyNumberMethods.nb_power (C member): Number Object Structures. (line 79) * PyNumberMethods.nb_remainder (C member): Number Object Structures. (line 75) * PyNumberMethods.nb_reserved (C member): Number Object Structures. (line 103) * PyNumberMethods.nb_rshift (C member): Number Object Structures. (line 93) * PyNumberMethods.nb_subtract (C member): Number Object Structures. (line 71) * PyNumberMethods.nb_true_divide (C member): Number Object Structures. (line 129) * PyNumberMethods.nb_xor (C member): Number Object Structures. (line 97) * PyNumber_Absolute (C function): Number Protocol. (line 85) * PyNumber_Add (C function): Number Protocol. (line 13) * PyNumber_And (C function): Number Protocol. (line 106) * PyNumber_AsSsize_t (C function): Number Protocol. (line 257) * PyNumber_Check (C function): Number Protocol. (line 6) * PyNumber_Divmod (C function): Number Protocol. (line 58) * PyNumber_Float (C function): Number Protocol. (line 237) * PyNumber_FloorDivide (C function): Number Protocol. (line 37) * PyNumber_Index (C function): Number Protocol. (line 244) * PyNumber_InPlaceAdd (C function): Number Protocol. (line 121) * PyNumber_InPlaceAnd (C function): Number Protocol. (line 209) * PyNumber_InPlaceFloorDivide (C function): Number Protocol. (line 154) * PyNumber_InPlaceLshift (C function): Number Protocol. (line 193) * PyNumber_InPlaceMatrixMultiply (C function): Number Protocol. (line 144) * PyNumber_InPlaceMultiply (C function): Number Protocol. (line 136) * PyNumber_InPlaceOr (C function): Number Protocol. (line 223) * PyNumber_InPlacePower (C function): Number Protocol. (line 181) * PyNumber_InPlaceRemainder (C function): Number Protocol. (line 173) * PyNumber_InPlaceRshift (C function): Number Protocol. (line 201) * PyNumber_InPlaceSubtract (C function): Number Protocol. (line 128) * PyNumber_InPlaceTrueDivide (C function): Number Protocol. (line 162) * PyNumber_InPlaceXor (C function): Number Protocol. (line 216) * PyNumber_Invert (C function): Number Protocol. (line 91) * PyNumber_Long (C function): Number Protocol. (line 230) * PyNumber_Lshift (C function): Number Protocol. (line 96) * PyNumber_MatrixMultiply (C function): Number Protocol. (line 28) * PyNumber_Multiply (C function): Number Protocol. (line 23) * PyNumber_Negative (C function): Number Protocol. (line 76) * PyNumber_Or (C function): Number Protocol. (line 116) * PyNumber_Positive (C function): Number Protocol. (line 81) * PyNumber_Power (C function): Number Protocol. (line 65) * PyNumber_Remainder (C function): Number Protocol. (line 52) * PyNumber_Rshift (C function): Number Protocol. (line 101) * PyNumber_Subtract (C function): Number Protocol. (line 18) * PyNumber_ToBase (C function): Number Protocol. (line 249) * PyNumber_TrueDivide (C function): Number Protocol. (line 43) * PyNumber_Xor (C function): Number Protocol. (line 111) * PyObject (C type): Common Object Structures. (line 17) * PyObject.ob_refcnt (C member): PyObject Slots. (line 30) * PyObject.ob_type (C member): PyObject Slots. (line 43) * PyObject._ob_next (C member): PyObject Slots. (line 13) * PyObject._ob_prev (C member): PyObject Slots. (line 13) * PyObjectArenaAllocator (C type): Customize pymalloc Arena Allocator. (line 8) * PyObject_AsCharBuffer (C function): Old Buffer Protocol. (line 21) * PyObject_ASCII (C function): Object Protocol. (line 176) * PyObject_AsFileDescriptor (C function): File Objects. (line 32) * PyObject_AsReadBuffer (C function): Old Buffer Protocol. (line 31) * PyObject_AsWriteBuffer (C function): Old Buffer Protocol. (line 50) * PyObject_Bytes (C function): Object Protocol. (line 197) * PyObject_Call (C function): Object Protocol. (line 254) * PyObject_CallFunction (C function): Object Protocol. (line 281) * PyObject_CallFunctionObjArgs (C function): Object Protocol. (line 323) * PyObject_CallMethod (C function): Object Protocol. (line 300) * PyObject_CallMethodObjArgs (C function): Object Protocol. (line 336) * PyObject_CallObject (C function): Object Protocol. (line 269) * PyObject_CallObject(): Calling Python Functions from C. (line 64) * PyObject_Calloc (C function): Object allocators. (line 25) * PyObject_CheckBuffer (C function): Buffer-related functions. (line 6) * PyObject_CheckReadBuffer (C function): Old Buffer Protocol. (line 40) * PyObject_Del (C function): Allocating Objects on the Heap. (line 51) * PyObject_DelAttr (C function): Object Protocol. (line 110) * PyObject_DelAttrString (C function): Object Protocol. (line 116) * PyObject_DelItem (C function): Object Protocol. (line 501) * PyObject_Dir (C function): Object Protocol. (line 507) * PyObject_Free (C function): Object allocators. (line 54) * PyObject_GC_Del (C function): Supporting Cyclic Garbage Collection. (line 71) * PyObject_GC_New (C function): Supporting Cyclic Garbage Collection. (line 34) * PyObject_GC_NewVar (C function): Supporting Cyclic Garbage Collection. (line 39) * PyObject_GC_Resize (C function): Supporting Cyclic Garbage Collection. (line 46) * PyObject_GC_Track (C function): Supporting Cyclic Garbage Collection. (line 54) * PyObject_GC_UnTrack (C function): Supporting Cyclic Garbage Collection. (line 76) * PyObject_GenericGetAttr (C function): Object Protocol. (line 63) * PyObject_GenericGetDict (C function): Object Protocol. (line 123) * PyObject_GenericSetAttr (C function): Object Protocol. (line 98) * PyObject_GenericSetDict (C function): Object Protocol. (line 131) * PyObject_GetArenaAllocator (C function): Customize pymalloc Arena Allocator. (line 26) * PyObject_GetAttr (C function): Object Protocol. (line 48) * PyObject_GetAttrString (C function): Object Protocol. (line 55) * PyObject_GetBuffer (C function): Buffer-related functions. (line 13) * PyObject_GetItem (C function): Object Protocol. (line 487) * PyObject_GetIter (C function): Object Protocol. (line 516) * PyObject_HasAttr (C function): Object Protocol. (line 25) * PyObject_HasAttrString (C function): Object Protocol. (line 36) * PyObject_Hash (C function): Object Protocol. (line 423) * PyObject_HashNotImplemented (C function): Object Protocol. (line 432) * PyObject_HEAD (C macro): Common Object Structures. (line 37) * PyObject_HEAD_INIT (C macro): Common Object Structures. (line 78) * PyObject_Init (C function): Allocating Objects on the Heap. (line 14) * PyObject_InitVar (C function): Allocating Objects on the Heap. (line 23) * PyObject_IsInstance (C function): Object Protocol. (line 227) * PyObject_IsSubclass (C function): Object Protocol. (line 206) * PyObject_IsTrue (C function): Object Protocol. (line 439) * PyObject_Length (C function): Object Protocol. (line 468) * PyObject_LengthHint (C function): Object Protocol. (line 476) * PyObject_Malloc (C function): Object allocators. (line 16) * PyObject_New (C function): Allocating Objects on the Heap. (line 30) * PyObject_NewVar (C function): Allocating Objects on the Heap. (line 38) * PyObject_Not (C function): Object Protocol. (line 445) * PyObject_Print (C function): Object Protocol. (line 17) * PyObject_Realloc (C function): Object allocators. (line 37) * PyObject_Repr (C function): Object Protocol. (line 164) * PyObject_RichCompare (C function): Object Protocol. (line 139) * PyObject_RichCompareBool (C function): Object Protocol. (line 149) * PyObject_SetArenaAllocator (C function): Customize pymalloc Arena Allocator. (line 31) * PyObject_SetAttr (C function): Object Protocol. (line 75) * PyObject_SetAttrString (C function): Object Protocol. (line 87) * PyObject_SetItem (C function): Object Protocol. (line 492) * PyObject_Size (C function): Object Protocol. (line 468) * PyObject_Str (C function): Object Protocol. (line 186) * PyObject_Type (C function): Object Protocol. (line 451) * PyObject_TypeCheck (C function): Object Protocol. (line 463) * PyObject_VAR_HEAD (C macro): Common Object Structures. (line 47) * PyOS_AfterFork (C function): Operating System Utilities. (line 75) * PyOS_AfterFork_Child (C function): Operating System Utilities. (line 53) * PyOS_AfterFork_Parent (C function): Operating System Utilities. (line 39) * PyOS_BeforeFork (C function): Operating System Utilities. (line 26) * PyOS_CheckStack (C function): Operating System Utilities. (line 85) * PyOS_double_to_string (C function): String conversion and formatting. (line 87) * PyOS_FSPath (C function): Operating System Utilities. (line 6) * PyOS_getsig (C function): Operating System Utilities. (line 93) * PyOS_InputHook (C variable): The Very High Level Layer. (line 165) * PyOS_ReadlineFunctionPointer (C variable): The Very High Level Layer. (line 175) * PyOS_setsig (C function): Operating System Utilities. (line 100) * PyOS_snprintf (C function): String conversion and formatting. (line 8) * PyOS_stricmp (C function): String conversion and formatting. (line 122) * PyOS_string_to_double (C function): String conversion and formatting. (line 54) * PyOS_strnicmp (C function): String conversion and formatting. (line 127) * PyOS_vsnprintf (C function): String conversion and formatting. (line 15) * PyParser_SimpleParseFile (C function): The Very High Level Layer. (line 221) * PyParser_SimpleParseFileFlags (C function): The Very High Level Layer. (line 229) * PyParser_SimpleParseString (C function): The Very High Level Layer. (line 196) * PyParser_SimpleParseStringFlags (C function): The Very High Level Layer. (line 203) * PyParser_SimpleParseStringFlagsFilename (C function): The Very High Level Layer. (line 211) * PyPI; (see Python Package Index (PyPI)): Installing the tools. (line 25) * PyPreConfig (C type): PyPreConfig. (line 6) * PyPreConfig.allocator (C member): PyPreConfig. (line 32) * PyPreConfig.coerce_c_locale (C member): PyPreConfig. (line 68) * PyPreConfig.coerce_c_locale_warn (C member): PyPreConfig. (line 73) * PyPreConfig.configure_locale (C member): PyPreConfig. (line 62) * PyPreConfig.dev_mode (C member): PyPreConfig. (line 77) * PyPreConfig.isolated (C member): PyPreConfig. (line 81) * PyPreConfig.legacy_windows_fs_encoding (C member): PyPreConfig. (line 85) * PyPreConfig.parse_argv (C member): PyPreConfig. (line 94) * PyPreConfig.use_environment (C member): PyPreConfig. (line 101) * PyPreConfig.utf8_mode (C member): PyPreConfig. (line 105) * PyPreConfig_InitIsolatedConfig (C function): PyPreConfig. (line 24) * PyPreConfig_InitPythonConfig (C function): PyPreConfig. (line 18) * PyProperty_Type (C variable): Descriptor Objects. (line 9) * PyRun_AnyFile (C function): The Very High Level Layer. (line 48) * PyRun_AnyFileEx (C function): The Very High Level Layer. (line 61) * PyRun_AnyFileExFlags (C function): The Very High Level Layer. (line 68) * PyRun_AnyFileFlags (C function): The Very High Level Layer. (line 54) * PyRun_File (C function): The Very High Level Layer. (line 255) * PyRun_FileEx (C function): The Very High Level Layer. (line 262) * PyRun_FileExFlags (C function): The Very High Level Layer. (line 276) * PyRun_FileFlags (C function): The Very High Level Layer. (line 269) * PyRun_InteractiveLoop (C function): The Very High Level Layer. (line 149) * PyRun_InteractiveLoopFlags (C function): The Very High Level Layer. (line 156) * PyRun_InteractiveOne (C function): The Very High Level Layer. (line 127) * PyRun_InteractiveOneFlags (C function): The Very High Level Layer. (line 134) * PyRun_SimpleFile (C function): The Very High Level Layer. (line 100) * PyRun_SimpleFileEx (C function): The Very High Level Layer. (line 106) * PyRun_SimpleFileExFlags (C function): The Very High Level Layer. (line 113) * PyRun_SimpleString (C function): The Very High Level Layer. (line 79) * PyRun_SimpleStringFlags (C function): The Very High Level Layer. (line 85) * PyRun_String (C function): The Very High Level Layer. (line 236) * PyRun_StringFlags (C function): The Very High Level Layer. (line 243) * PySeqIter_Check (C function): Iterator Objects. (line 18) * PySeqIter_New (C function): Iterator Objects. (line 22) * PySeqIter_Type (C variable): Iterator Objects. (line 12) * PySequenceMethods (C type): Sequence Object Structures. (line 6) * PySequenceMethods.sq_ass_item (C member): Sequence Object Structures. (line 45) * PySequenceMethods.sq_concat (C member): Sequence Object Structures. (line 18) * PySequenceMethods.sq_contains (C member): Sequence Object Structures. (line 54) * PySequenceMethods.sq_inplace_concat (C member): Sequence Object Structures. (line 61) * PySequenceMethods.sq_inplace_repeat (C member): Sequence Object Structures. (line 71) * PySequenceMethods.sq_item (C member): Sequence Object Structures. (line 31) * PySequenceMethods.sq_length (C member): Sequence Object Structures. (line 11) * PySequenceMethods.sq_repeat (C member): Sequence Object Structures. (line 24) * PySequence_Check (C function): Sequence Protocol. (line 6) * PySequence_Concat (C function): Sequence Protocol. (line 20) * PySequence_Contains (C function): Sequence Protocol. (line 99) * PySequence_Count (C function): Sequence Protocol. (line 91) * PySequence_DelItem (C function): Sequence Protocol. (line 70) * PySequence_DelSlice (C function): Sequence Protocol. (line 83) * PySequence_Fast (C function): Sequence Protocol. (line 127) * PySequence_Fast_GET_ITEM (C function): Sequence Protocol. (line 149) * PySequence_Fast_GET_SIZE (C function): Sequence Protocol. (line 141) * PySequence_Fast_ITEMS (C function): Sequence Protocol. (line 156) * PySequence_GetItem (C function): Sequence Protocol. (line 47) * PySequence_GetItem(): Reference Count Details. (line 117) * PySequence_GetSlice (C function): Sequence Protocol. (line 52) * PySequence_Index (C function): Sequence Protocol. (line 105) * PySequence_InPlaceConcat (C function): Sequence Protocol. (line 31) * PySequence_InPlaceRepeat (C function): Sequence Protocol. (line 39) * PySequence_ITEM (C function): Sequence Protocol. (line 166) * PySequence_Length (C function): Sequence Protocol. (line 14) * PySequence_List (C function): Sequence Protocol. (line 112) * PySequence_Repeat (C function): Sequence Protocol. (line 25) * PySequence_SetItem (C function): Sequence Protocol. (line 58) * PySequence_SetSlice (C function): Sequence Protocol. (line 75) * PySequence_Size (C function): Sequence Protocol. (line 14) * PySequence_Tuple (C function): Sequence Protocol. (line 118) * PySetObject (C type): Set Objects. (line 19) * PySet_Add (C function): Set Objects. (line 108) * PySet_Check (C function): Set Objects. (line 45) * PySet_Clear (C function): Set Objects. (line 140) * PySet_ClearFreeList (C function): Set Objects. (line 144) * PySet_Contains (C function): Set Objects. (line 99) * PySet_Discard (C function): Set Objects. (line 123) * PySet_GET_SIZE (C function): Set Objects. (line 95) * PySet_New (C function): Set Objects. (line 70) * PySet_Pop (C function): Set Objects. (line 133) * PySet_Size (C function): Set Objects. (line 88) * PySet_Type (C variable): Set Objects. (line 31) * PySignal_SetWakeupFd (C function): Signal Handling<2>. (line 28) * PySlice_AdjustIndices (C function): Slice Objects. (line 101) * PySlice_Check (C function): Slice Objects. (line 11) * PySlice_GetIndices (C function): Slice Objects. (line 25) * PySlice_GetIndicesEx (C function): Slice Objects. (line 44) * PySlice_New (C function): Slice Objects. (line 15) * PySlice_Type (C variable): Slice Objects. (line 6) * PySlice_Unpack (C function): Slice Objects. (line 87) * PyState_AddModule (C function): Module lookup. (line 23) * PyState_FindModule (C function): Module lookup. (line 15) * PyState_RemoveModule (C function): Module lookup. (line 45) * PyStatus (C type): PyStatus. (line 6) * PyStatus.err_msg (C member): PyStatus. (line 20) * PyStatus.exitcode (C member): PyStatus. (line 16) * PyStatus.func (C member): PyStatus. (line 24) * PyStatus_Error (C function): PyStatus. (line 34) * PyStatus_Exception (C function): PyStatus. (line 48) * PyStatus_Exit (C function): PyStatus. (line 42) * PyStatus_IsError (C function): PyStatus. (line 54) * PyStatus_IsExit (C function): PyStatus. (line 58) * PyStatus_NoMemory (C function): PyStatus. (line 38) * PyStatus_Ok (C function): PyStatus. (line 30) * PyStructSequence_Desc (C type): Struct Sequence Objects. (line 34) * PyStructSequence_Field (C type): Struct Sequence Objects. (line 57) * PyStructSequence_GetItem (C function): Struct Sequence Objects. (line 86) * PyStructSequence_GET_ITEM (C function): Struct Sequence Objects. (line 93) * PyStructSequence_InitType (C function): Struct Sequence Objects. (line 19) * PyStructSequence_InitType2 (C function): Struct Sequence Objects. (line 25) * PyStructSequence_New (C function): Struct Sequence Objects. (line 81) * PyStructSequence_NewType (C function): Struct Sequence Objects. (line 11) * PyStructSequence_SetItem (C function): Struct Sequence Objects. (line 99) * PyStructSequence_SET_ITEM (C function): Struct Sequence Objects. (line 108) * PyStructSequence_UnnamedField (C variable): Struct Sequence Objects. (line 77) * PySys_AddAuditHook (C function): System Functions. (line 129) * PySys_AddWarnOption (C function): System Functions. (line 27) * PySys_AddWarnOptionUnicode (C function): System Functions. (line 33) * PySys_AddXOption (C function): System Functions. (line 87) * PySys_Audit (C function): System Functions. (line 103) * PySys_FormatStderr (C function): System Functions. (line 80) * PySys_FormatStdout (C function): System Functions. (line 72) * PySys_GetObject (C function): System Functions. (line 11) * PySys_GetXOptions (C function): System Functions. (line 96) * PySys_ResetWarnOptions (C function): System Functions. (line 22) * PySys_SetArgv (C function): Process-wide parameters. (line 255) * PySys_SetArgv(): Initializing and finalizing the interpreter. (line 8) * PySys_SetArgvEx (C function): Process-wide parameters. (line 214) * PySys_SetArgvEx(): Embedding Python<2>. (line 17) * PySys_SetArgvEx() <1>: Initializing and finalizing the interpreter. (line 8) * PySys_SetObject (C function): System Functions. (line 16) * PySys_SetPath (C function): System Functions. (line 43) * PySys_WriteStderr (C function): System Functions. (line 67) * PySys_WriteStdout (C function): System Functions. (line 49) * Python 3000: Glossary. (line 1075) * Python Editor: IDLE<3>. (line 8) * Python Enhancement Proposals; PEP 1: New Development Process. (line 67) * Python Enhancement Proposals; PEP 1 <1>: New Development Process. (line 82) * Python Enhancement Proposals; PEP 1 <2>: Glossary. (line 1041) * Python Enhancement Proposals; PEP 100: Unicode<2>. (line 15) * Python Enhancement Proposals; PEP 11: PEP 538 Legacy C Locale Coercion. (line 19) * Python Enhancement Proposals; PEP 11 <1>: Unsupported Operating Systems. (line 6) * Python Enhancement Proposals; PEP 11 <2>: Library Changes. (line 15) * Python Enhancement Proposals; PEP 11 <3>: Using Python on Windows. (line 18) * Python Enhancement Proposals; PEP 11 <4>: Other Platforms. (line 8) * Python Enhancement Proposals; PEP 201: New Development Process. (line 86) * Python Enhancement Proposals; PEP 205: PEP 205 Weak References. (line 82) * Python Enhancement Proposals; PEP 205 <1>: weakref — Weak references. (line 311) * Python Enhancement Proposals; PEP 207: PEP 207 Rich Comparisons. (line 71) * Python Enhancement Proposals; PEP 207 <1>: PEP 207 Rich Comparisons. (line 77) * Python Enhancement Proposals; PEP 208: PEP 208 New Coercion Model. (line 30) * Python Enhancement Proposals; PEP 217: PEP 217 Interactive Display Hook. (line 27) * Python Enhancement Proposals; PEP 218: PEP 218 Built-In Set Objects. (line 50) * Python Enhancement Proposals; PEP 218 <1>: Other Language Changes<12>. (line 12) * Python Enhancement Proposals; PEP 218 <2>: PEP 218 A Standard Set Datatype. (line 80) * Python Enhancement Proposals; PEP 227: PEP 227 Nested Scopes. (line 96) * Python Enhancement Proposals; PEP 227 <1>: PEP 227 Nested Scopes<2>. (line 96) * Python Enhancement Proposals; PEP 227 <2>: __future__ — Future statement definitions. (line 71) * Python Enhancement Proposals; PEP 229: PEP 229 New Build System. (line 39) * Python Enhancement Proposals; PEP 230: PEP 230 Warning Framework. (line 73) * Python Enhancement Proposals; PEP 232: PEP 232 Function Attributes. (line 36) * Python Enhancement Proposals; PEP 234: PEP 234 Iterators. (line 124) * Python Enhancement Proposals; PEP 235: Introduction<12>. (line 37) * Python Enhancement Proposals; PEP 236: PEP 227 Nested Scopes<2>. (line 87) * Python Enhancement Proposals; PEP 236 <1>: PEP 227 Nested Scopes<2>. (line 88) * Python Enhancement Proposals; PEP 236 <2>: PEP 236 __future__ Directives. (line 29) * Python Enhancement Proposals; PEP 236 <3>: Future statements. (line 85) * Python Enhancement Proposals; PEP 237: Integers. (line 6) * Python Enhancement Proposals; PEP 237 <1>: PEP 237 Unifying Long Integers and Integers. (line 22) * Python Enhancement Proposals; PEP 237 <2>: Other Language Changes<12>. (line 18) * Python Enhancement Proposals; PEP 237 <3>: PEP 237 Unifying Long Integers and Integers<2>. (line 37) * Python Enhancement Proposals; PEP 237 <4>: printf-style String Formatting. (line 182) * Python Enhancement Proposals; PEP 237 <5>: printf-style Bytes Formatting. (line 189) * Python Enhancement Proposals; PEP 238: Integers. (line 10) * Python Enhancement Proposals; PEP 238 <1>: PEP 238 Changing the Division Operator. (line 21) * Python Enhancement Proposals; PEP 238 <2>: PEP 238 Changing the Division Operator. (line 27) * Python Enhancement Proposals; PEP 238 <3>: PEP 238 Changing the Division Operator. (line 68) * Python Enhancement Proposals; PEP 238 <4>: __future__ — Future statement definitions. (line 77) * Python Enhancement Proposals; PEP 238 <5>: The Very High Level Layer. (line 425) * Python Enhancement Proposals; PEP 238 <6>: Glossary. (line 458) * Python Enhancement Proposals; PEP 241: PEP 241 Metadata in Python Packages. (line 15) * Python Enhancement Proposals; PEP 241 <1>: PEP 241 Metadata in Python Packages. (line 28) * Python Enhancement Proposals; PEP 241 <2>: PEP 241 Metadata in Python Packages. (line 35) * Python Enhancement Proposals; PEP 243: PEP 241 Metadata in Python Packages. (line 39) * Python Enhancement Proposals; PEP 247: hmac<2>. (line 20) * Python Enhancement Proposals; PEP 249: The sqlite3 package. (line 18) * Python Enhancement Proposals; PEP 249 <1>: The sqlite3 package. (line 110) * Python Enhancement Proposals; PEP 249 <2>: sqlite3 — DB-API 2 0 interface for SQLite databases. (line 18) * Python Enhancement Proposals; PEP 249 <3>: sqlite3 — DB-API 2 0 interface for SQLite databases. (line 113) * Python Enhancement Proposals; PEP 252: Related Links. (line 17) * Python Enhancement Proposals; PEP 252 <1>: Related Links. (line 17) * Python Enhancement Proposals; PEP 252 <2>: Implementing Descriptors. (line 24) * Python Enhancement Proposals; PEP 253: Old and New Classes. (line 28) * Python Enhancement Proposals; PEP 253 <1>: Multiple Inheritance The Diamond Rule. (line 8) * Python Enhancement Proposals; PEP 253 <2>: Related Links. (line 17) * Python Enhancement Proposals; PEP 253 <3>: Related Links. (line 19) * Python Enhancement Proposals; PEP 253 <4>: Related Links. (line 21) * Python Enhancement Proposals; PEP 255: PEP 255 Simple Generators. (line 45) * Python Enhancement Proposals; PEP 255 <1>: PEP 255 Simple Generators. (line 131) * Python Enhancement Proposals; PEP 255 <2>: PEP 255 Simple Generators<2>. (line 43) * Python Enhancement Proposals; PEP 255 <3>: PEP 255 Simple Generators<2>. (line 129) * Python Enhancement Proposals; PEP 255 <4>: Yield expressions. (line 88) * Python Enhancement Proposals; PEP 255 <5>: __future__ — Future statement definitions. (line 74) * Python Enhancement Proposals; PEP 261: Unicode Changes. (line 18) * Python Enhancement Proposals; PEP 261 <1>: Unicode Changes. (line 61) * Python Enhancement Proposals; PEP 263: Other Language Changes<11>. (line 98) * Python Enhancement Proposals; PEP 263 <1>: PEP 263 Source Code Encodings. (line 29) * Python Enhancement Proposals; PEP 263 <2>: Introduction<12>. (line 41) * Python Enhancement Proposals; PEP 263 <3>: Tokenizing Input. (line 35) * Python Enhancement Proposals; PEP 263 <4>: Tokenizing Input. (line 89) * Python Enhancement Proposals; PEP 263 <5>: Unicode Literals in Python Source Code. (line 48) * Python Enhancement Proposals; PEP 264: Other Changes and Fixes<3>. (line 55) * Python Enhancement Proposals; PEP 273: PEP 273 Importing Modules from ZIP Archives. (line 41) * Python Enhancement Proposals; PEP 273 <1>: PEP 273 Importing Modules from ZIP Archives. (line 44) * Python Enhancement Proposals; PEP 273 <2>: zipimport — Import modules from Zip archives. (line 42) * Python Enhancement Proposals; PEP 273 <3>: zipimport — Import modules from Zip archives. (line 45) * Python Enhancement Proposals; PEP 274: New Syntax. (line 38) * Python Enhancement Proposals; PEP 275: Why isn’t there a switch or case statement in Python?. (line 8) * Python Enhancement Proposals; PEP 277: PEP 277 Unicode file name support for Windows NT. (line 32) * Python Enhancement Proposals; PEP 278: PEP 278 Universal Newline Support. (line 33) * Python Enhancement Proposals; PEP 278 <1>: Glossary. (line 1287) * Python Enhancement Proposals; PEP 279: PEP 279 enumerate. (line 27) * Python Enhancement Proposals; PEP 282: PEP 282 The logging Package. (line 101) * Python Enhancement Proposals; PEP 282 <1>: PEP 282 The logging Package. (line 107) * Python Enhancement Proposals; PEP 282 <2>: Archiving operations. (line 45) * Python Enhancement Proposals; PEP 282 <3>: Integration with the warnings module. (line 36) * Python Enhancement Proposals; PEP 282 <4>: distutils log — Simple PEP 282-style logging. (line 6) * Python Enhancement Proposals; PEP 285: PEP 285 A Boolean Type. (line 47) * Python Enhancement Proposals; PEP 285 <1>: PEP 285 A Boolean Type. (line 70) * Python Enhancement Proposals; PEP 288: PEP 342 New Generator Features. (line 146) * Python Enhancement Proposals; PEP 289: PEP 289 Generator Expressions. (line 56) * Python Enhancement Proposals; PEP 289 <1>: Other Language Changes<12>. (line 15) * Python Enhancement Proposals; PEP 289 <2>: Python documentation. (line 12) * Python Enhancement Proposals; PEP 292: PEP 292 Simpler String Substitutions. (line 45) * Python Enhancement Proposals; PEP 292 <1>: Template strings. (line 6) * Python Enhancement Proposals; PEP 293: PEP 293 Codec Error Handling Callbacks. (line 33) * Python Enhancement Proposals; PEP 3000: Python 3 0. (line 43) * Python Enhancement Proposals; PEP 301: PEP 301 Package Index and Metadata for Distutils. (line 45) * Python Enhancement Proposals; PEP 301 <1>: distutils command register — Register a module with the Python Package Index. (line 7) * Python Enhancement Proposals; PEP 302: Using importlib as the Implementation of Import. (line 13) * Python Enhancement Proposals; PEP 302 <1>: Visible Changes. (line 18) * Python Enhancement Proposals; PEP 302 <2>: Porting Python code. (line 71) * Python Enhancement Proposals; PEP 302 <3>: New Improved and Deprecated Modules<2>. (line 106) * Python Enhancement Proposals; PEP 302 <4>: New Improved and Removed Modules. (line 289) * Python Enhancement Proposals; PEP 302 <5>: PEP 273 Importing Modules from ZIP Archives. (line 46) * Python Enhancement Proposals; PEP 302 <6>: PEP 302 New Import Hooks. (line 13) * Python Enhancement Proposals; PEP 302 <7>: PEP 302 New Import Hooks. (line 38) * Python Enhancement Proposals; PEP 302 <8>: PEP 302 New Import Hooks. (line 62) * Python Enhancement Proposals; PEP 302 <9>: The import system. (line 42) * Python Enhancement Proposals; PEP 302 <10>: References. (line 10) * Python Enhancement Proposals; PEP 302 <11>: Built-in Functions. (line 1783) * Python Enhancement Proposals; PEP 302 <12>: linecache — Random access to text lines. (line 31) * Python Enhancement Proposals; PEP 302 <13>: sys — System-specific parameters and functions. (line 1091) * Python Enhancement Proposals; PEP 302 <14>: sys — System-specific parameters and functions. (line 1101) * Python Enhancement Proposals; PEP 302 <15>: zipimport — Import modules from Zip archives. (line 47) * Python Enhancement Proposals; PEP 302 <16>: zipimport — Import modules from Zip archives. (line 49) * Python Enhancement Proposals; PEP 302 <17>: pkgutil — Package extension utility. (line 55) * Python Enhancement Proposals; PEP 302 <18>: pkgutil — Package extension utility. (line 57) * Python Enhancement Proposals; PEP 302 <19>: pkgutil — Package extension utility. (line 58) * Python Enhancement Proposals; PEP 302 <20>: pkgutil — Package extension utility. (line 66) * Python Enhancement Proposals; PEP 302 <21>: pkgutil — Package extension utility. (line 74) * Python Enhancement Proposals; PEP 302 <22>: pkgutil — Package extension utility. (line 87) * Python Enhancement Proposals; PEP 302 <23>: pkgutil — Package extension utility. (line 103) * Python Enhancement Proposals; PEP 302 <24>: pkgutil — Package extension utility. (line 118) * Python Enhancement Proposals; PEP 302 <25>: pkgutil — Package extension utility. (line 138) * Python Enhancement Proposals; PEP 302 <26>: pkgutil — Package extension utility. (line 159) * Python Enhancement Proposals; PEP 302 <27>: pkgutil — Package extension utility. (line 198) * Python Enhancement Proposals; PEP 302 <28>: runpy — Locating and executing Python modules. (line 32) * Python Enhancement Proposals; PEP 302 <29>: Introduction<12>. (line 45) * Python Enhancement Proposals; PEP 302 <30>: importlib abc – Abstract base classes related to import. (line 38) * Python Enhancement Proposals; PEP 302 <31>: importlib abc – Abstract base classes related to import. (line 160) * Python Enhancement Proposals; PEP 302 <32>: importlib abc – Abstract base classes related to import. (line 361) * Python Enhancement Proposals; PEP 302 <33>: importlib abc – Abstract base classes related to import. (line 385) * Python Enhancement Proposals; PEP 302 <34>: importlib abc – Abstract base classes related to import. (line 456) * Python Enhancement Proposals; PEP 302 <35>: imp — Access the import internals. (line 347) * Python Enhancement Proposals; PEP 302 <36>: Glossary. (line 450) * Python Enhancement Proposals; PEP 302 <37>: Glossary. (line 777) * Python Enhancement Proposals; PEP 305: PEP 305 Comma-separated Files. (line 42) * Python Enhancement Proposals; PEP 305 <1>: csv — CSV File Reading and Writing. (line 38) * Python Enhancement Proposals; PEP 307: PEP 307 Pickle Enhancements. (line 8) * Python Enhancement Proposals; PEP 307 <1>: PEP 307 Pickle Enhancements. (line 30) * Python Enhancement Proposals; PEP 307 <2>: PEP 307 Pickle Enhancements. (line 42) * Python Enhancement Proposals; PEP 307 <3>: Data stream format. (line 32) * Python Enhancement Proposals; PEP 308: PEP 308 Conditional Expressions. (line 72) * Python Enhancement Proposals; PEP 308 <1>: PEP 308 Conditional Expressions. (line 78) * Python Enhancement Proposals; PEP 308 <2>: Conditional expressions. (line 17) * Python Enhancement Proposals; PEP 309: PEP 309 Partial Function Application. (line 73) * Python Enhancement Proposals; PEP 3100: Python 3 0. (line 44) * Python Enhancement Proposals; PEP 3101: PEP 3101 A New Approach To String Formatting. (line 6) * Python Enhancement Proposals; PEP 3101 <1>: PEP 3101 A New Approach To String Formatting. (line 9) * Python Enhancement Proposals; PEP 3101 <2>: PEP 3101 Advanced String Formatting. (line 162) * Python Enhancement Proposals; PEP 3101 <3>: Custom String Formatting. (line 8) * Python Enhancement Proposals; PEP 3101 <4>: Custom String Formatting. (line 60) * Python Enhancement Proposals; PEP 3102: New Syntax. (line 13) * Python Enhancement Proposals; PEP 3104: New Syntax. (line 24) * Python Enhancement Proposals; PEP 3104 <1>: The nonlocal statement. (line 26) * Python Enhancement Proposals; PEP 3105: Print Is A Function. (line 8) * Python Enhancement Proposals; PEP 3105 <1>: PEP 3105 print As a Function. (line 35) * Python Enhancement Proposals; PEP 3105 <2>: __future__ — Future statement definitions. (line 87) * Python Enhancement Proposals; PEP 3106: PEP 3106 Dictionary Views. (line 58) * Python Enhancement Proposals; PEP 3107: PEP 563 Postponed Evaluation of Annotations. (line 7) * Python Enhancement Proposals; PEP 3107 <1>: PEP 484 - Type Hints. (line 7) * Python Enhancement Proposals; PEP 3107 <2>: New Syntax. (line 6) * Python Enhancement Proposals; PEP 3107 <3>: Function Annotations. (line 7) * Python Enhancement Proposals; PEP 3107 <4>: Function definitions. (line 123) * Python Enhancement Proposals; PEP 3108: Library Changes. (line 7) * Python Enhancement Proposals; PEP 3108 <1>: Library Changes. (line 17) * Python Enhancement Proposals; PEP 3108 <2>: Library Changes. (line 95) * Python Enhancement Proposals; PEP 3109: Changed Syntax. (line 6) * Python Enhancement Proposals; PEP 3109 <1>: Changes To Exceptions. (line 29) * Python Enhancement Proposals; PEP 3110: Changed Syntax. (line 16) * Python Enhancement Proposals; PEP 3110 <1>: Changes To Exceptions. (line 35) * Python Enhancement Proposals; PEP 3110 <2>: PEP 3110 Exception-Handling Changes. (line 48) * Python Enhancement Proposals; PEP 3111: Builtins. (line 12) * Python Enhancement Proposals; PEP 3112: PEP 3112 Byte Literals. (line 75) * Python Enhancement Proposals; PEP 3112 <1>: __future__ — Future statement definitions. (line 90) * Python Enhancement Proposals; PEP 3113: Removed Syntax. (line 6) * Python Enhancement Proposals; PEP 3114: Operators And Special Methods. (line 19) * Python Enhancement Proposals; PEP 3115: types<4>. (line 10) * Python Enhancement Proposals; PEP 3115 <1>: Changed Syntax. (line 18) * Python Enhancement Proposals; PEP 3115 <2>: Preparing the class namespace. (line 21) * Python Enhancement Proposals; PEP 3115 <3>: Class definitions. (line 71) * Python Enhancement Proposals; PEP 3115 <4>: Dynamic Type Creation. (line 54) * Python Enhancement Proposals; PEP 3116: Optimizations<7>. (line 8) * Python Enhancement Proposals; PEP 3116 <1>: PEP 3116 New I/O Library. (line 69) * Python Enhancement Proposals; PEP 3116 <2>: Glossary. (line 1287) * Python Enhancement Proposals; PEP 3118: Pickle protocol 5 with out-of-band data buffers. (line 13) * Python Enhancement Proposals; PEP 3118 <1>: PEP 3118 New memoryview implementation and buffer protocol documentation. (line 6) * Python Enhancement Proposals; PEP 3118 <2>: API changes. (line 29) * Python Enhancement Proposals; PEP 3118 <3>: Build and C API Changes<4>. (line 8) * Python Enhancement Proposals; PEP 3118 <4>: Build and C API Changes<7>. (line 12) * Python Enhancement Proposals; PEP 3118 <5>: PEP 3118 Revised Buffer Protocol. (line 46) * Python Enhancement Proposals; PEP 3118 <6>: Memory Views. (line 110) * Python Enhancement Proposals; PEP 3119: PEP 3119 Abstract Base Classes. (line 139) * Python Enhancement Proposals; PEP 3119 <1>: Customizing instance and subclass checks. (line 35) * Python Enhancement Proposals; PEP 3119 <2>: Collections Abstract Base Classes. (line 316) * Python Enhancement Proposals; PEP 3119 <3>: abc — Abstract Base Classes. (line 11) * Python Enhancement Proposals; PEP 3119 <4>: Object Protocol. (line 218) * Python Enhancement Proposals; PEP 3119 <5>: Object Protocol. (line 238) * Python Enhancement Proposals; PEP 3120: Text Vs Data Instead Of Unicode Vs 8-bit. (line 107) * Python Enhancement Proposals; PEP 3120 <1>: Lexical analysis. (line 12) * Python Enhancement Proposals; PEP 3120 <2>: Introduction<12>. (line 77) * Python Enhancement Proposals; PEP 3121: Build and C API Changes<7>. (line 14) * Python Enhancement Proposals; PEP 3121 <1>: Initializing C modules. (line 55) * Python Enhancement Proposals; PEP 3123: Build and C API Changes<7>. (line 16) * Python Enhancement Proposals; PEP 3127: PEP 3127 Integer Literal Support and Syntax. (line 47) * Python Enhancement Proposals; PEP 3129: PEP 3129 Class Decorators. (line 24) * Python Enhancement Proposals; PEP 3129 <1>: Class definitions. (line 77) * Python Enhancement Proposals; PEP 3131: Text Vs Data Instead Of Unicode Vs 8-bit. (line 109) * Python Enhancement Proposals; PEP 3131 <1>: Identifiers and keywords. (line 10) * Python Enhancement Proposals; PEP 3131 <2>: Identifiers and keywords. (line 19) * Python Enhancement Proposals; PEP 3132: New Syntax. (line 28) * Python Enhancement Proposals; PEP 3132 <1>: Assignment statements. (line 159) * Python Enhancement Proposals; PEP 3134: Changed Syntax. (line 6) * Python Enhancement Proposals; PEP 3134 <1>: Changes To Exceptions. (line 40) * Python Enhancement Proposals; PEP 3134 <2>: Changes To Exceptions. (line 60) * Python Enhancement Proposals; PEP 3135: Builtins. (line 6) * Python Enhancement Proposals; PEP 3135 <1>: Creating the class object. (line 54) * Python Enhancement Proposals; PEP 3137: PEP 3137 The memoryview Object. (line 49) * Python Enhancement Proposals; PEP 3138: Text Vs Data Instead Of Unicode Vs 8-bit. (line 103) * Python Enhancement Proposals; PEP 314: PEP 314 Metadata for Python Software Packages v1 1. (line 42) * Python Enhancement Proposals; PEP 314 <1>: distutils core — Core Distutils functionality. (line 103) * Python Enhancement Proposals; PEP 3141: PEP 3141 A Type Hierarchy for Numbers. (line 43) * Python Enhancement Proposals; PEP 3141 <1>: numbers — Numeric abstract base classes. (line 10) * Python Enhancement Proposals; PEP 3141 <2>: abc — Abstract Base Classes. (line 12) * Python Enhancement Proposals; PEP 3144: ipaddress<4>. (line 10) * Python Enhancement Proposals; PEP 3147: PEP 421 Adding sys implementation. (line 21) * Python Enhancement Proposals; PEP 3147 <1>: PEP 3147 PYC Repository Directories. (line 69) * Python Enhancement Proposals; PEP 3147 <2>: “Compiled” Python files. (line 47) * Python Enhancement Proposals; PEP 3147 <3>: Import-related module attributes. (line 79) * Python Enhancement Proposals; PEP 3147 <4>: test support — Utilities for the Python test suite. (line 192) * Python Enhancement Proposals; PEP 3147 <5>: runpy — Locating and executing Python modules. (line 87) * Python Enhancement Proposals; PEP 3147 <6>: Introduction<12>. (line 81) * Python Enhancement Proposals; PEP 3147 <7>: importlib util – Utility code for importers. (line 24) * Python Enhancement Proposals; PEP 3147 <8>: importlib util – Utility code for importers. (line 60) * Python Enhancement Proposals; PEP 3147 <9>: importlib util – Utility code for importers. (line 64) * Python Enhancement Proposals; PEP 3147 <10>: py_compile — Compile Python source files. (line 30) * Python Enhancement Proposals; PEP 3147 <11>: py_compile — Compile Python source files. (line 69) * Python Enhancement Proposals; PEP 3147 <12>: Command-line use. (line 56) * Python Enhancement Proposals; PEP 3147 <13>: Public functions. (line 36) * Python Enhancement Proposals; PEP 3147 <14>: Public functions. (line 101) * Python Enhancement Proposals; PEP 3147 <15>: imp — Access the import internals. (line 200) * Python Enhancement Proposals; PEP 3147 <16>: imp — Access the import internals. (line 207) * Python Enhancement Proposals; PEP 3147 <17>: imp — Access the import internals. (line 230) * Python Enhancement Proposals; PEP 3147 <18>: imp — Access the import internals. (line 234) * Python Enhancement Proposals; PEP 3147 <19>: imp — Access the import internals. (line 246) * Python Enhancement Proposals; PEP 3147 <20>: Importing Modules<2>. (line 199) * Python Enhancement Proposals; PEP 3147 <21>: How do I create a pyc file?. (line 12) * Python Enhancement Proposals; PEP 3147 <22>: distutils util — Miscellaneous other utility functions. (line 132) * Python Enhancement Proposals; PEP 3148: PEP 3148 The concurrent futures module. (line 51) * Python Enhancement Proposals; PEP 3148 <1>: Module Functions. (line 61) * Python Enhancement Proposals; PEP 3149: PEP 3149 ABI Version Tagged so Files. (line 33) * Python Enhancement Proposals; PEP 3149 <1>: sys — System-specific parameters and functions. (line 15) * Python Enhancement Proposals; PEP 3151: PEP 3151 Reworking the OS and IO exception hierarchy. (line 84) * Python Enhancement Proposals; PEP 3151 <1>: OS exceptions. (line 114) * Python Enhancement Proposals; PEP 3151 <2>: Exceptions<11>. (line 10) * Python Enhancement Proposals; PEP 3151 <3>: select — Waiting for I/O completion. (line 28) * Python Enhancement Proposals; PEP 3151 <4>: resource — Resource usage information. (line 21) * Python Enhancement Proposals; PEP 3151 <5>: Standard Exceptions. (line 181) * Python Enhancement Proposals; PEP 3154: Summary – Release Highlights<2>. (line 57) * Python Enhancement Proposals; PEP 3154 <1>: pickle<4>. (line 16) * Python Enhancement Proposals; PEP 3154 <2>: Data stream format. (line 42) * Python Enhancement Proposals; PEP 3155: PEP 3155 Qualified name for classes and functions. (line 62) * Python Enhancement Proposals; PEP 3155 <1>: Glossary. (line 1104) * Python Enhancement Proposals; PEP 3156: Summary – Release Highlights<2>. (line 31) * Python Enhancement Proposals; PEP 3156 <1>: Summary – Release Highlights<2>. (line 44) * Python Enhancement Proposals; PEP 3156 <2>: asyncio<6>. (line 6) * Python Enhancement Proposals; PEP 3156 <3>: asyncio<6>. (line 17) * Python Enhancement Proposals; PEP 3156 <4>: selectors<2>. (line 6) * Python Enhancement Proposals; PEP 318: PEP 318 Decorators for Functions and Methods. (line 101) * Python Enhancement Proposals; PEP 318 <1>: PEP 318 Decorators for Functions and Methods. (line 125) * Python Enhancement Proposals; PEP 318 <2>: Other Language Changes<12>. (line 9) * Python Enhancement Proposals; PEP 318 <3>: Class definitions. (line 80) * Python Enhancement Proposals; PEP 322: PEP 322 Reverse Iteration. (line 35) * Python Enhancement Proposals; PEP 322 <1>: Other Language Changes<12>. (line 13) * Python Enhancement Proposals; PEP 324: PEP 324 New subprocess Module. (line 86) * Python Enhancement Proposals; PEP 324 <1>: subprocess — Subprocess management. (line 25) * Python Enhancement Proposals; PEP 325: PEP 342 New Generator Features. (line 147) * Python Enhancement Proposals; PEP 327: The Context type. (line 56) * Python Enhancement Proposals; PEP 328: Porting Python code. (line 36) * Python Enhancement Proposals; PEP 328 <1>: Removed Syntax. (line 29) * Python Enhancement Proposals; PEP 328 <2>: PEP 328 Absolute and Relative Imports. (line 6) * Python Enhancement Proposals; PEP 328 <3>: PEP 328 Absolute and Relative Imports. (line 82) * Python Enhancement Proposals; PEP 328 <4>: PEP 328 Multi-line Imports. (line 35) * Python Enhancement Proposals; PEP 328 <5>: Other Language Changes<12>. (line 21) * Python Enhancement Proposals; PEP 328 <6>: References. (line 20) * Python Enhancement Proposals; PEP 328 <7>: Built-in Functions. (line 1801) * Python Enhancement Proposals; PEP 328 <8>: __future__ — Future statement definitions. (line 80) * Python Enhancement Proposals; PEP 328 <9>: Introduction<12>. (line 49) * Python Enhancement Proposals; PEP 331: PEP 331 Locale-Independent Float/String Conversions. (line 38) * Python Enhancement Proposals; PEP 333: The wsgiref package. (line 8) * Python Enhancement Proposals; PEP 333 <1>: The wsgiref package. (line 31) * Python Enhancement Proposals; PEP 3333: PEP 3333 Python Web Server Gateway Interface v1 0 1. (line 50) * Python Enhancement Proposals; PEP 3333 <1>: wsgiref — WSGI Utilities and Reference Implementation. (line 24) * Python Enhancement Proposals; PEP 3333 <2>: wsgiref util – WSGI environment utilities. (line 8) * Python Enhancement Proposals; PEP 3333 <3>: wsgiref util – WSGI environment utilities. (line 10) * Python Enhancement Proposals; PEP 3333 <4>: wsgiref util – WSGI environment utilities. (line 28) * Python Enhancement Proposals; PEP 3333 <5>: wsgiref util – WSGI environment utilities. (line 74) * Python Enhancement Proposals; PEP 3333 <6>: wsgiref headers – WSGI response header tools. (line 12) * Python Enhancement Proposals; PEP 3333 <7>: wsgiref simple_server – a simple WSGI HTTP server. (line 21) * Python Enhancement Proposals; PEP 3333 <8>: wsgiref simple_server – a simple WSGI HTTP server. (line 96) * Python Enhancement Proposals; PEP 3333 <9>: wsgiref validate — WSGI conformance checker. (line 13) * Python Enhancement Proposals; PEP 3333 <10>: wsgiref validate — WSGI conformance checker. (line 41) * Python Enhancement Proposals; PEP 3333 <11>: wsgiref handlers – server/gateway base classes. (line 234) * Python Enhancement Proposals; PEP 3333 <12>: wsgiref handlers – server/gateway base classes. (line 250) * Python Enhancement Proposals; PEP 3333 <13>: wsgiref handlers – server/gateway base classes. (line 257) * Python Enhancement Proposals; PEP 3333 <14>: wsgiref handlers – server/gateway base classes. (line 266) * Python Enhancement Proposals; PEP 3333 <15>: wsgiref handlers – server/gateway base classes. (line 308) * Python Enhancement Proposals; PEP 338: PEP 338 Executing Modules as Scripts. (line 21) * Python Enhancement Proposals; PEP 338 <1>: Interface options. (line 100) * Python Enhancement Proposals; PEP 338 <2>: References. (line 24) * Python Enhancement Proposals; PEP 338 <3>: runpy — Locating and executing Python modules. (line 171) * Python Enhancement Proposals; PEP 339: Build and C API Changes<10>. (line 45) * Python Enhancement Proposals; PEP 341: PEP 341 Unified try/except/finally. (line 44) * Python Enhancement Proposals; PEP 342: PEP 342 New Generator Features. (line 42) * Python Enhancement Proposals; PEP 342 <1>: PEP 342 New Generator Features. (line 140) * Python Enhancement Proposals; PEP 342 <2>: Porting to Python 2 5. (line 15) * Python Enhancement Proposals; PEP 342 <3>: Yield expressions. (line 93) * Python Enhancement Proposals; PEP 342 <4>: Collections Abstract Base Classes. (line 152) * Python Enhancement Proposals; PEP 342 <5>: Passing values into a generator. (line 25) * Python Enhancement Proposals; PEP 342 <6>: Python documentation. (line 14) * Python Enhancement Proposals; PEP 343: The contextlib module. (line 64) * Python Enhancement Proposals; PEP 343 <1>: PEP 342 New Generator Features. (line 129) * Python Enhancement Proposals; PEP 343 <2>: The contextlib module<2>. (line 64) * Python Enhancement Proposals; PEP 343 <3>: With Statement Context Managers. (line 45) * Python Enhancement Proposals; PEP 343 <4>: The with statement. (line 98) * Python Enhancement Proposals; PEP 343 <5>: Using a context manager as a function decorator. (line 51) * Python Enhancement Proposals; PEP 343 <6>: __future__ — Future statement definitions. (line 84) * Python Enhancement Proposals; PEP 343 <7>: Glossary. (line 259) * Python Enhancement Proposals; PEP 347: Build and C API Changes<10>. (line 10) * Python Enhancement Proposals; PEP 352: Changes To Exceptions. (line 9) * Python Enhancement Proposals; PEP 352 <1>: Deprecations and Removals. (line 9) * Python Enhancement Proposals; PEP 352 <2>: PEP 352 Exceptions as New-Style Classes. (line 57) * Python Enhancement Proposals; PEP 353: PEP 353 Using ssize_t as the index type. (line 48) * Python Enhancement Proposals; PEP 353 <1>: PEP 353 Using ssize_t as the index type. (line 54) * Python Enhancement Proposals; PEP 353 <2>: Build and C API Changes<10>. (line 20) * Python Enhancement Proposals; PEP 356: What’s New in Python 2 5. (line 10) * Python Enhancement Proposals; PEP 357: PEP 357 The ‘__index__’ method. (line 39) * Python Enhancement Proposals; PEP 361: What’s New in Python 2 6. (line 10) * Python Enhancement Proposals; PEP 362: PEP 362 Function Signature Object. (line 19) * Python Enhancement Proposals; PEP 362 <1>: Introspecting callables with the Signature object. (line 343) * Python Enhancement Proposals; PEP 362 <2>: Glossary. (line 94) * Python Enhancement Proposals; PEP 362 <3>: Glossary. (line 988) * Python Enhancement Proposals; PEP 366: Visible Changes. (line 24) * Python Enhancement Proposals; PEP 366 <1>: Import-related module attributes. (line 30) * Python Enhancement Proposals; PEP 366 <2>: Import-related module attributes. (line 34) * Python Enhancement Proposals; PEP 366 <3>: References. (line 17) * Python Enhancement Proposals; PEP 366 <4>: References. (line 21) * Python Enhancement Proposals; PEP 366 <5>: runpy — Locating and executing Python modules. (line 175) * Python Enhancement Proposals; PEP 366 <6>: Introduction<12>. (line 53) * Python Enhancement Proposals; PEP 370: PEP 370 Per-user site-packages Directory. (line 36) * Python Enhancement Proposals; PEP 370 <1>: Miscellaneous options. (line 125) * Python Enhancement Proposals; PEP 370 <2>: Environment variables. (line 168) * Python Enhancement Proposals; PEP 370 <3>: Environment variables. (line 180) * Python Enhancement Proposals; PEP 370 <4>: Command Line Interface<4>. (line 37) * Python Enhancement Proposals; PEP 371: PEP 371 The multiprocessing Package. (line 145) * Python Enhancement Proposals; PEP 372: PEP 372 Ordered Dictionaries. (line 31) * Python Enhancement Proposals; PEP 372 <1>: PEP 372 Adding an Ordered Dictionary to collections. (line 97) * Python Enhancement Proposals; PEP 373: The Future for Python 2 x. (line 23) * Python Enhancement Proposals; PEP 378: PEP 378 Format Specifier for Thousands Separator. (line 32) * Python Enhancement Proposals; PEP 378 <1>: PEP 378 Format Specifier for Thousands Separator<2>. (line 37) * Python Enhancement Proposals; PEP 378 <2>: Format Specification Mini-Language. (line 103) * Python Enhancement Proposals; PEP 380: PEP 380 Syntax for Delegating to a Subgenerator. (line 66) * Python Enhancement Proposals; PEP 380 <1>: Yield expressions. (line 98) * Python Enhancement Proposals; PEP 383: Error Handlers. (line 58) * Python Enhancement Proposals; PEP 383 <1>: Socket families. (line 15) * Python Enhancement Proposals; PEP 383 <2>: Locale Encoding. (line 14) * Python Enhancement Proposals; PEP 383 <3>: Locale Encoding. (line 50) * Python Enhancement Proposals; PEP 383 <4>: File System Encoding. (line 9) * Python Enhancement Proposals; PEP 384: PEP 384 Defining a Stable ABI. (line 24) * Python Enhancement Proposals; PEP 384 <1>: Stable Application Binary Interface. (line 36) * Python Enhancement Proposals; PEP 385: Code Repository. (line 13) * Python Enhancement Proposals; PEP 389: PEP 389 Argparse Command Line Parsing Module. (line 92) * Python Enhancement Proposals; PEP 389 <1>: PEP 389 The argparse Module for Parsing Command Lines. (line 100) * Python Enhancement Proposals; PEP 391: PEP 391 Dictionary Based Configuration for Logging. (line 52) * Python Enhancement Proposals; PEP 391 <1>: PEP 391 Dictionary-Based Configuration For Logging. (line 94) * Python Enhancement Proposals; PEP 392: What’s New In Python 3 2. (line 16) * Python Enhancement Proposals; PEP 393: PEP 393 Flexible String Representation. (line 16) * Python Enhancement Proposals; PEP 393 <1>: Functionality. (line 6) * Python Enhancement Proposals; PEP 393 <2>: Performance and resource usage. (line 29) * Python Enhancement Proposals; PEP 393 <3>: Optimizations<5>. (line 8) * Python Enhancement Proposals; PEP 393 <4>: Build and C API Changes<4>. (line 12) * Python Enhancement Proposals; PEP 393 <5>: Deprecated Python modules functions and methods<4>. (line 10) * Python Enhancement Proposals; PEP 393 <6>: Deprecated functions and types of the C API<3>. (line 6) * Python Enhancement Proposals; PEP 393 <7>: Porting C code. (line 17) * Python Enhancement Proposals; PEP 393 <8>: Encodings and Unicode. (line 7) * Python Enhancement Proposals; PEP 393 <9>: sys — System-specific parameters and functions. (line 1016) * Python Enhancement Proposals; PEP 393 <10>: Unicode Objects. (line 6) * Python Enhancement Proposals; PEP 393 <11>: Deprecated Py_UNICODE APIs. (line 8) * Python Enhancement Proposals; PEP 395: Open issues. (line 18) * Python Enhancement Proposals; PEP 397: PEP 486 Make the Python Launcher aware of virtual environments. (line 6) * Python Enhancement Proposals; PEP 397 <1>: PEP 397 Python Launcher for Windows. (line 31) * Python Enhancement Proposals; PEP 397 <2>: Python Launcher for Windows. (line 18) * Python Enhancement Proposals; PEP 397 <3>: Creating virtual environments. (line 195) * Python Enhancement Proposals; PEP 398: What’s New In Python 3 3. (line 13) * Python Enhancement Proposals; PEP 4: Library Changes. (line 13) * Python Enhancement Proposals; PEP 405: PEP 405 Virtual Environments. (line 22) * Python Enhancement Proposals; PEP 405 <1>: venv — Creation of virtual environments. (line 19) * Python Enhancement Proposals; PEP 409: PEP 409 Suppressing exception context. (line 63) * Python Enhancement Proposals; PEP 411: sys — System-specific parameters and functions. (line 814) * Python Enhancement Proposals; PEP 411 <1>: sys — System-specific parameters and functions. (line 824) * Python Enhancement Proposals; PEP 411 <2>: sys — System-specific parameters and functions. (line 1427) * Python Enhancement Proposals; PEP 411 <3>: sys — System-specific parameters and functions. (line 1447) * Python Enhancement Proposals; PEP 411 <4>: Glossary. (line 1071) * Python Enhancement Proposals; PEP 412: PEP 412 Key-Sharing Dictionary. (line 15) * Python Enhancement Proposals; PEP 414: PEP 414 Explicit Unicode literals. (line 17) * Python Enhancement Proposals; PEP 414 <1>: String and Bytes literals. (line 60) * Python Enhancement Proposals; PEP 418: time<5>. (line 6) * Python Enhancement Proposals; PEP 420: PEP 420 Implicit Namespace Packages. (line 9) * Python Enhancement Proposals; PEP 420 <1>: PEP 420 Implicit Namespace Packages. (line 14) * Python Enhancement Proposals; PEP 420 <2>: The import system. (line 45) * Python Enhancement Proposals; PEP 420 <3>: Namespace packages. (line 27) * Python Enhancement Proposals; PEP 420 <4>: module __path__. (line 21) * Python Enhancement Proposals; PEP 420 <5>: module __path__. (line 21) * Python Enhancement Proposals; PEP 420 <6>: References. (line 11) * Python Enhancement Proposals; PEP 420 <7>: References. (line 13) * Python Enhancement Proposals; PEP 420 <8>: References. (line 13) * Python Enhancement Proposals; PEP 420 <9>: Introduction<12>. (line 57) * Python Enhancement Proposals; PEP 420 <10>: Glossary. (line 450) * Python Enhancement Proposals; PEP 420 <11>: Glossary. (line 898) * Python Enhancement Proposals; PEP 420 <12>: Glossary. (line 1046) * Python Enhancement Proposals; PEP 421: SimpleNamespace. (line 16) * Python Enhancement Proposals; PEP 421 <1>: sys — System-specific parameters and functions. (line 926) * Python Enhancement Proposals; PEP 421 <2>: sys — System-specific parameters and functions. (line 931) * Python Enhancement Proposals; PEP 424: Other Language Changes<5>. (line 57) * Python Enhancement Proposals; PEP 424 <1>: operator<2>. (line 8) * Python Enhancement Proposals; PEP 427: Key terms. (line 36) * Python Enhancement Proposals; PEP 428: Summary – Release Highlights<2>. (line 39) * Python Enhancement Proposals; PEP 428 <1>: pathlib<5>. (line 17) * Python Enhancement Proposals; PEP 428 <2>: pathlib — Object-oriented filesystem paths. (line 39) * Python Enhancement Proposals; PEP 429: What’s New In Python 3 4. (line 16) * Python Enhancement Proposals; PEP 432: Other CPython implementation changes. (line 7) * Python Enhancement Proposals; PEP 432 <1>: Multi-Phase Initialization Private Provisional API. (line 7) * Python Enhancement Proposals; PEP 432 <2>: Multi-Phase Initialization Private Provisional API. (line 57) * Python Enhancement Proposals; PEP 434: PEP 434 IDLE Enhancement Exception for All Branches. (line 6) * Python Enhancement Proposals; PEP 435: Summary – Release Highlights<2>. (line 36) * Python Enhancement Proposals; PEP 435 <1>: enum<5>. (line 6) * Python Enhancement Proposals; PEP 435 <2>: enum<5>. (line 15) * Python Enhancement Proposals; PEP 436: Summary – Release Highlights<2>. (line 120) * Python Enhancement Proposals; PEP 436 <1>: PEP 436 Argument Clinic. (line 6) * Python Enhancement Proposals; PEP 436 <2>: PEP 436 Argument Clinic. (line 28) * Python Enhancement Proposals; PEP 441: zipapp<2>. (line 6) * Python Enhancement Proposals; PEP 441 <1>: zipapp<2>. (line 24) * Python Enhancement Proposals; PEP 442: Summary – Release Highlights<2>. (line 113) * Python Enhancement Proposals; PEP 442 <1>: Summary – Release Highlights<2>. (line 115) * Python Enhancement Proposals; PEP 442 <2>: PEP 442 Safe Object Finalization. (line 6) * Python Enhancement Proposals; PEP 442 <3>: PEP 442 Safe Object Finalization. (line 21) * Python Enhancement Proposals; PEP 442 <4>: gc — Garbage Collector interface. (line 225) * Python Enhancement Proposals; PEP 442 <5>: Finalization and De-allocation. (line 77) * Python Enhancement Proposals; PEP 442 <6>: PyTypeObject Slots. (line 1387) * Python Enhancement Proposals; PEP 443: Summary – Release Highlights<2>. (line 55) * Python Enhancement Proposals; PEP 443 <1>: functools<4>. (line 22) * Python Enhancement Proposals; PEP 443 <2>: Glossary. (line 546) * Python Enhancement Proposals; PEP 445: Summary – Release Highlights<2>. (line 118) * Python Enhancement Proposals; PEP 445 <1>: PEP 445 Customization of CPython Memory Allocators. (line 6) * Python Enhancement Proposals; PEP 445 <2>: PEP 445 Customization of CPython Memory Allocators. (line 12) * Python Enhancement Proposals; PEP 445 <3>: Other Improvements<2>. (line 63) * Python Enhancement Proposals; PEP 446: Summary – Release Highlights<2>. (line 14) * Python Enhancement Proposals; PEP 446 <1>: Summary – Release Highlights<2>. (line 78) * Python Enhancement Proposals; PEP 446 <2>: PEP 446 Newly Created File Descriptors Are Non-Inheritable. (line 6) * Python Enhancement Proposals; PEP 446 <3>: PEP 446 Newly Created File Descriptors Are Non-Inheritable. (line 26) * Python Enhancement Proposals; PEP 448: PEP 448 - Additional Unpacking Generalizations. (line 6) * Python Enhancement Proposals; PEP 448 <1>: PEP 448 - Additional Unpacking Generalizations. (line 39) * Python Enhancement Proposals; PEP 448 <2>: Dictionary displays. (line 29) * Python Enhancement Proposals; PEP 448 <3>: Calls. (line 113) * Python Enhancement Proposals; PEP 448 <4>: Expression lists. (line 22) * Python Enhancement Proposals; PEP 450: Summary – Release Highlights<2>. (line 47) * Python Enhancement Proposals; PEP 450 <1>: statistics<3>. (line 6) * Python Enhancement Proposals; PEP 450 <2>: statistics<3>. (line 14) * Python Enhancement Proposals; PEP 451: PEP 489 Multi-phase extension module initialization. (line 7) * Python Enhancement Proposals; PEP 451 <1>: Summary – Release Highlights<2>. (line 22) * Python Enhancement Proposals; PEP 451 <2>: PEP 451 A ModuleSpec Type for the Import System. (line 6) * Python Enhancement Proposals; PEP 451 <3>: References. (line 26) * Python Enhancement Proposals; PEP 451 <4>: sys — System-specific parameters and functions. (line 1046) * Python Enhancement Proposals; PEP 451 <5>: pkgutil — Package extension utility. (line 90) * Python Enhancement Proposals; PEP 451 <6>: pkgutil — Package extension utility. (line 121) * Python Enhancement Proposals; PEP 451 <7>: runpy — Locating and executing Python modules. (line 91) * Python Enhancement Proposals; PEP 451 <8>: runpy — Locating and executing Python modules. (line 164) * Python Enhancement Proposals; PEP 451 <9>: runpy — Locating and executing Python modules. (line 179) * Python Enhancement Proposals; PEP 451 <10>: Introduction<12>. (line 61) * Python Enhancement Proposals; PEP 451 <11>: Multi-phase initialization. (line 72) * Python Enhancement Proposals; PEP 451 <12>: Glossary. (line 450) * Python Enhancement Proposals; PEP 453: Summary – Release Highlights<2>. (line 12) * Python Enhancement Proposals; PEP 453 <1>: Summary – Release Highlights<2>. (line 34) * Python Enhancement Proposals; PEP 453 <2>: Bootstrapping pip By Default. (line 6) * Python Enhancement Proposals; PEP 453 <3>: Documentation Changes. (line 21) * Python Enhancement Proposals; PEP 453 <4>: ensurepip. (line 7) * Python Enhancement Proposals; PEP 453 <5>: venv<4>. (line 13) * Python Enhancement Proposals; PEP 453 <6>: Other Improvements<2>. (line 73) * Python Enhancement Proposals; PEP 453 <7>: PEP 477 Backport ensurepip PEP 453 to Python 2 7. (line 6) * Python Enhancement Proposals; PEP 453 <8>: Bootstrapping pip By Default<2>. (line 6) * Python Enhancement Proposals; PEP 453 <9>: Documentation Changes<2>. (line 21) * Python Enhancement Proposals; PEP 453 <10>: ensurepip — Bootstrapping the pip installer. (line 33) * Python Enhancement Proposals; PEP 454: Summary – Release Highlights<2>. (line 50) * Python Enhancement Proposals; PEP 454 <1>: tracemalloc<3>. (line 6) * Python Enhancement Proposals; PEP 454 <2>: tracemalloc<3>. (line 22) * Python Enhancement Proposals; PEP 456: Summary – Release Highlights<2>. (line 75) * Python Enhancement Proposals; PEP 456 <1>: PEP 456 Secure and Interchangeable Hash Algorithm. (line 6) * Python Enhancement Proposals; PEP 461: PEP 461 - percent formatting support for bytes and bytearray. (line 6) * Python Enhancement Proposals; PEP 461 <1>: PEP 461 - percent formatting support for bytes and bytearray. (line 41) * Python Enhancement Proposals; PEP 461 <2>: printf-style Bytes Formatting. (line 198) * Python Enhancement Proposals; PEP 465: PEP 465 - A dedicated infix operator for matrix multiplication. (line 6) * Python Enhancement Proposals; PEP 465 <1>: PEP 465 - A dedicated infix operator for matrix multiplication. (line 45) * Python Enhancement Proposals; PEP 465 <2>: Build and C API Changes<3>. (line 43) * Python Enhancement Proposals; PEP 466: PEP 466 Network Security Enhancements for Python 2 7. (line 6) * Python Enhancement Proposals; PEP 466 <1>: PEP 466 Network Security Enhancements for Python 2 7. (line 11) * Python Enhancement Proposals; PEP 466 <2>: PEP 466 Network Security Enhancements for Python 2 7. (line 21) * Python Enhancement Proposals; PEP 466 <3>: PEP 466 Network Security Enhancements for Python 2 7. (line 32) * Python Enhancement Proposals; PEP 468: PEP 468 Preserving Keyword Argument Order. (line 12) * Python Enhancement Proposals; PEP 468 <1>: OrderedDict objects. (line 85) * Python Enhancement Proposals; PEP 471: PEP 471 - os scandir function – a better and faster directory iterator. (line 6) * Python Enhancement Proposals; PEP 471 <1>: PEP 471 - os scandir function – a better and faster directory iterator. (line 29) * Python Enhancement Proposals; PEP 475: PEP 475 Retry system calls failing with EINTR. (line 32) * Python Enhancement Proposals; PEP 475 <1>: PEP 475 Retry system calls failing with EINTR. (line 77) * Python Enhancement Proposals; PEP 475 <2>: Changes in the Python API<4>. (line 6) * Python Enhancement Proposals; PEP 475 <3>: Built-in Functions. (line 1251) * Python Enhancement Proposals; PEP 475 <4>: OS exceptions. (line 78) * Python Enhancement Proposals; PEP 475 <5>: File Descriptor Operations. (line 293) * Python Enhancement Proposals; PEP 475 <6>: File Descriptor Operations. (line 573) * Python Enhancement Proposals; PEP 475 <7>: File Descriptor Operations. (line 692) * Python Enhancement Proposals; PEP 475 <8>: Process Management. (line 804) * Python Enhancement Proposals; PEP 475 <9>: Functions<2>. (line 228) * Python Enhancement Proposals; PEP 475 <10>: Socket Objects. (line 28) * Python Enhancement Proposals; PEP 475 <11>: Socket Objects. (line 80) * Python Enhancement Proposals; PEP 475 <12>: Socket Objects. (line 234) * Python Enhancement Proposals; PEP 475 <13>: Socket Objects. (line 248) * Python Enhancement Proposals; PEP 475 <14>: Socket Objects. (line 323) * Python Enhancement Proposals; PEP 475 <15>: Socket Objects. (line 395) * Python Enhancement Proposals; PEP 475 <16>: Socket Objects. (line 414) * Python Enhancement Proposals; PEP 475 <17>: Socket Objects. (line 433) * Python Enhancement Proposals; PEP 475 <18>: Socket Objects. (line 475) * Python Enhancement Proposals; PEP 475 <19>: select — Waiting for I/O completion. (line 154) * Python Enhancement Proposals; PEP 475 <20>: /dev/poll Polling Objects. (line 82) * Python Enhancement Proposals; PEP 475 <21>: Edge and Level Trigger Polling epoll Objects. (line 99) * Python Enhancement Proposals; PEP 475 <22>: Polling Objects. (line 94) * Python Enhancement Proposals; PEP 475 <23>: Kqueue Objects. (line 36) * Python Enhancement Proposals; PEP 475 <24>: Classes<3>. (line 133) * Python Enhancement Proposals; PEP 475 <25>: Module contents<2>. (line 516) * Python Enhancement Proposals; PEP 475 <26>: Module contents<2>. (line 534) * Python Enhancement Proposals; PEP 476: PEP 476 Enabling certificate verification by default for stdlib http clients<2>. (line 6) * Python Enhancement Proposals; PEP 477: PEP 477 Backport ensurepip PEP 453 to Python 2 7. (line 6) * Python Enhancement Proposals; PEP 478: What’s New In Python 3 5. (line 17) * Python Enhancement Proposals; PEP 479: Changes in Python Behavior. (line 11) * Python Enhancement Proposals; PEP 479 <1>: PEP 479 Change StopIteration handling inside generators. (line 12) * Python Enhancement Proposals; PEP 479 <2>: PEP 479 Change StopIteration handling inside generators. (line 47) * Python Enhancement Proposals; PEP 479 <3>: Concrete exceptions. (line 234) * Python Enhancement Proposals; PEP 479 <4>: Concrete exceptions. (line 236) * Python Enhancement Proposals; PEP 479 <5>: __future__ — Future statement definitions. (line 93) * Python Enhancement Proposals; PEP 483: PEP 484 - Type Hints. (line 47) * Python Enhancement Proposals; PEP 483 <1>: typing — Support for type hints. (line 21) * Python Enhancement Proposals; PEP 484: ast. (line 17) * Python Enhancement Proposals; PEP 484 <1>: ast. (line 20) * Python Enhancement Proposals; PEP 484 <2>: PEP 560 Core Support for typing module and Generic Types. (line 6) * Python Enhancement Proposals; PEP 484 <3>: PEP 526 Syntax for variable annotations. (line 6) * Python Enhancement Proposals; PEP 484 <4>: PEP 484 - Type Hints. (line 16) * Python Enhancement Proposals; PEP 484 <5>: PEP 484 - Type Hints. (line 41) * Python Enhancement Proposals; PEP 484 <6>: Function Annotations. (line 8) * Python Enhancement Proposals; PEP 484 <7>: Emulating generic types. (line 6) * Python Enhancement Proposals; PEP 484 <8>: Annotated assignment statements. (line 45) * Python Enhancement Proposals; PEP 484 <9>: Function definitions. (line 127) * Python Enhancement Proposals; PEP 484 <10>: typing — Support for type hints. (line 16) * Python Enhancement Proposals; PEP 484 <11>: typing — Support for type hints. (line 20) * Python Enhancement Proposals; PEP 484 <12>: NewType. (line 64) * Python Enhancement Proposals; PEP 484 <13>: Nominal vs structural subtyping. (line 6) * Python Enhancement Proposals; PEP 484 <14>: Nominal vs structural subtyping. (line 14) * Python Enhancement Proposals; PEP 484 <15>: Classes functions and decorators. (line 40) * Python Enhancement Proposals; PEP 484 <16>: Classes functions and decorators. (line 45) * Python Enhancement Proposals; PEP 484 <17>: Classes functions and decorators. (line 134) * Python Enhancement Proposals; PEP 484 <18>: Classes functions and decorators. (line 688) * Python Enhancement Proposals; PEP 484 <19>: ast Helpers. (line 16) * Python Enhancement Proposals; PEP 484 <20>: ast Helpers. (line 26) * Python Enhancement Proposals; PEP 484 <21>: Glossary. (line 61) * Python Enhancement Proposals; PEP 484 <22>: Glossary. (line 483) * Python Enhancement Proposals; PEP 484 <23>: Glossary. (line 1262) * Python Enhancement Proposals; PEP 484 <24>: Glossary. (line 1279) * Python Enhancement Proposals; PEP 484 <25>: Glossary. (line 1309) * Python Enhancement Proposals; PEP 485: PEP 485 A function for testing approximate equality. (line 6) * Python Enhancement Proposals; PEP 485 <1>: PEP 485 A function for testing approximate equality. (line 36) * Python Enhancement Proposals; PEP 485 <2>: Number-theoretic and representation functions. (line 135) * Python Enhancement Proposals; PEP 485 <3>: Classification functions. (line 54) * Python Enhancement Proposals; PEP 486: PEP 486 Make the Python Launcher aware of virtual environments. (line 6) * Python Enhancement Proposals; PEP 486 <1>: PEP 486 Make the Python Launcher aware of virtual environments. (line 14) * Python Enhancement Proposals; PEP 487: PEP 487 Simpler customization of class creation. (line 32) * Python Enhancement Proposals; PEP 487 <1>: PEP 487 Descriptor Protocol Enhancements. (line 6) * Python Enhancement Proposals; PEP 487 <2>: PEP 487 Descriptor Protocol Enhancements. (line 33) * Python Enhancement Proposals; PEP 487 <3>: Changes in the Python API<3>. (line 104) * Python Enhancement Proposals; PEP 488: PEP 488 Elimination of PYO files. (line 6) * Python Enhancement Proposals; PEP 488 <1>: PEP 488 Elimination of PYO files. (line 20) * Python Enhancement Proposals; PEP 488 <2>: Changes in the Python API<4>. (line 79) * Python Enhancement Proposals; PEP 488 <3>: Miscellaneous options. (line 71) * Python Enhancement Proposals; PEP 488 <4>: Miscellaneous options. (line 73) * Python Enhancement Proposals; PEP 488 <5>: Miscellaneous options. (line 80) * Python Enhancement Proposals; PEP 488 <6>: Miscellaneous options. (line 82) * Python Enhancement Proposals; PEP 488 <7>: test support — Utilities for the Python test suite. (line 192) * Python Enhancement Proposals; PEP 488 <8>: Introduction<12>. (line 65) * Python Enhancement Proposals; PEP 488 <9>: importlib util – Utility code for importers. (line 24) * Python Enhancement Proposals; PEP 488 <10>: importlib util – Utility code for importers. (line 64) * Python Enhancement Proposals; PEP 488 <11>: py_compile — Compile Python source files. (line 31) * Python Enhancement Proposals; PEP 488 <12>: distutils util — Miscellaneous other utility functions. (line 132) * Python Enhancement Proposals; PEP 488 <13>: distutils util — Miscellaneous other utility functions. (line 169) * Python Enhancement Proposals; PEP 489: PEP 489 Multi-phase extension module initialization. (line 6) * Python Enhancement Proposals; PEP 489 <1>: PEP 489 Multi-phase extension module initialization. (line 18) * Python Enhancement Proposals; PEP 489 <2>: Build and C API Changes<3>. (line 37) * Python Enhancement Proposals; PEP 489 <3>: Introduction<12>. (line 69) * Python Enhancement Proposals; PEP 489 <4>: importlib machinery – Importers and path hooks. (line 77) * Python Enhancement Proposals; PEP 489 <5>: importlib machinery – Importers and path hooks. (line 322) * Python Enhancement Proposals; PEP 489 <6>: importlib machinery – Importers and path hooks. (line 328) * Python Enhancement Proposals; PEP 489 <7>: The Module’s Method Table and Initialization Function. (line 129) * Python Enhancement Proposals; PEP 489 <8>: Building C and C++ Extensions. (line 40) * Python Enhancement Proposals; PEP 489 <9>: Multi-phase initialization. (line 108) * Python Enhancement Proposals; PEP 492: PEP 525 Asynchronous Generators. (line 6) * Python Enhancement Proposals; PEP 492 <1>: New Keywords. (line 7) * Python Enhancement Proposals; PEP 492 <2>: PEP 492 - Coroutines with async and await syntax. (line 6) * Python Enhancement Proposals; PEP 492 <3>: PEP 492 - Coroutines with async and await syntax. (line 97) * Python Enhancement Proposals; PEP 492 <4>: New Keywords<2>. (line 7) * Python Enhancement Proposals; PEP 492 <5>: Changes in the C API<4>. (line 25) * Python Enhancement Proposals; PEP 492 <6>: Awaitable Objects. (line 27) * Python Enhancement Proposals; PEP 492 <7>: Yield expressions. (line 105) * Python Enhancement Proposals; PEP 492 <8>: The async with statement. (line 45) * Python Enhancement Proposals; PEP 492 <9>: Collections Abstract Base Classes. (line 247) * Python Enhancement Proposals; PEP 492 <10>: Code Objects Bit Flags. (line 42) * Python Enhancement Proposals; PEP 492 <11>: Code Objects Bit Flags. (line 51) * Python Enhancement Proposals; PEP 492 <12>: Glossary. (line 100) * Python Enhancement Proposals; PEP 492 <13>: Glossary. (line 133) * Python Enhancement Proposals; PEP 492 <14>: Glossary. (line 140) * Python Enhancement Proposals; PEP 492 <15>: Glossary. (line 149) * Python Enhancement Proposals; PEP 492 <16>: Glossary. (line 161) * Python Enhancement Proposals; PEP 492 <17>: Glossary. (line 288) * Python Enhancement Proposals; PEP 492 <18>: Glossary. (line 295) * Python Enhancement Proposals; PEP 493: PEP 493 HTTPS verification migration tools for Python 2 7. (line 6) * Python Enhancement Proposals; PEP 494: What’s New In Python 3 6. (line 17) * Python Enhancement Proposals; PEP 495: PEP 495 Local Time Disambiguation. (line 13) * Python Enhancement Proposals; PEP 495 <1>: PEP 495 Local Time Disambiguation. (line 36) * Python Enhancement Proposals; PEP 498: PEP 498 Formatted string literals. (line 6) * Python Enhancement Proposals; PEP 498 <1>: PEP 498 Formatted string literals. (line 27) * Python Enhancement Proposals; PEP 498 <2>: Formatted string literals. (line 141) * Python Enhancement Proposals; PEP 498 <3>: Glossary. (line 419) * Python Enhancement Proposals; PEP 5: PEP 230 Warning Framework. (line 66) * Python Enhancement Proposals; PEP 5 <1>: Is it reasonable to propose incompatible changes to Python?. (line 14) * Python Enhancement Proposals; PEP 506: secrets. (line 19) * Python Enhancement Proposals; PEP 506 <1>: secrets — Generate secure random numbers for managing secrets. (line 24) * Python Enhancement Proposals; PEP 511: Changes in the Python API<3>. (line 32) * Python Enhancement Proposals; PEP 515: PEP 515 Underscores in Numeric Literals. (line 6) * Python Enhancement Proposals; PEP 515 <1>: PEP 515 Underscores in Numeric Literals. (line 32) * Python Enhancement Proposals; PEP 515 <2>: Format Specification Mini-Language. (line 111) * Python Enhancement Proposals; PEP 519: PEP 519 Adding a file system path protocol. (line 62) * Python Enhancement Proposals; PEP 519 <1>: Glossary. (line 1025) * Python Enhancement Proposals; PEP 520: PEP 520 Preserving Class Attribute Definition Order. (line 17) * Python Enhancement Proposals; PEP 523: PEP 523 Adding a frame evaluation API to CPython. (line 12) * Python Enhancement Proposals; PEP 523 <1>: PEP 523 Adding a frame evaluation API to CPython. (line 26) * Python Enhancement Proposals; PEP 524: Summary – Release highlights<2>. (line 77) * Python Enhancement Proposals; PEP 524 <1>: os<3>. (line 20) * Python Enhancement Proposals; PEP 524 <2>: os<3>. (line 25) * Python Enhancement Proposals; PEP 524 <3>: Random numbers<2>. (line 42) * Python Enhancement Proposals; PEP 525: PEP 525 Asynchronous Generators. (line 23) * Python Enhancement Proposals; PEP 525 <1>: Yield expressions. (line 103) * Python Enhancement Proposals; PEP 525 <2>: Collections Abstract Base Classes. (line 247) * Python Enhancement Proposals; PEP 525 <3>: sys — System-specific parameters and functions. (line 811) * Python Enhancement Proposals; PEP 525 <4>: sys — System-specific parameters and functions. (line 1422) * Python Enhancement Proposals; PEP 525 <5>: Code Objects Bit Flags. (line 60) * Python Enhancement Proposals; PEP 525 <6>: Glossary. (line 134) * Python Enhancement Proposals; PEP 526: ast. (line 18) * Python Enhancement Proposals; PEP 526 <1>: PEP 563 Postponed Evaluation of Annotations. (line 8) * Python Enhancement Proposals; PEP 526 <2>: PEP 526 Syntax for variable annotations. (line 30) * Python Enhancement Proposals; PEP 526 <3>: typing<2>. (line 23) * Python Enhancement Proposals; PEP 526 <4>: Annotated assignment statements. (line 39) * Python Enhancement Proposals; PEP 526 <5>: Function definitions. (line 131) * Python Enhancement Proposals; PEP 526 <6>: typing — Support for type hints. (line 17) * Python Enhancement Proposals; PEP 526 <7>: Classes functions and decorators. (line 535) * Python Enhancement Proposals; PEP 526 <8>: Classes functions and decorators. (line 573) * Python Enhancement Proposals; PEP 526 <9>: Classes functions and decorators. (line 907) * Python Enhancement Proposals; PEP 526 <10>: dataclasses — Data Classes. (line 16) * Python Enhancement Proposals; PEP 526 <11>: Class variables. (line 8) * Python Enhancement Proposals; PEP 526 <12>: ast Helpers. (line 16) * Python Enhancement Proposals; PEP 526 <13>: Glossary. (line 61) * Python Enhancement Proposals; PEP 526 <14>: Glossary. (line 1309) * Python Enhancement Proposals; PEP 528: PEP 528 Change Windows console encoding to UTF-8. (line 17) * Python Enhancement Proposals; PEP 528 <1>: UTF-8 mode. (line 42) * Python Enhancement Proposals; PEP 528 <2>: Global configuration variables. (line 105) * Python Enhancement Proposals; PEP 529: Changes in the Python API. (line 7) * Python Enhancement Proposals; PEP 529 <1>: PEP 529 Change Windows filesystem encoding to UTF-8. (line 22) * Python Enhancement Proposals; PEP 529 <2>: Environment variables. (line 307) * Python Enhancement Proposals; PEP 529 <3>: UTF-8 mode. (line 45) * Python Enhancement Proposals; PEP 529 <4>: Files and Directories. (line 289) * Python Enhancement Proposals; PEP 529 <5>: sys — System-specific parameters and functions. (line 666) * Python Enhancement Proposals; PEP 529 <6>: sys — System-specific parameters and functions. (line 1461) * Python Enhancement Proposals; PEP 529 <7>: File System Encoding. (line 9) * Python Enhancement Proposals; PEP 529 <8>: Global configuration variables. (line 93) * Python Enhancement Proposals; PEP 530: PEP 530 Asynchronous Comprehensions. (line 6) * Python Enhancement Proposals; PEP 530 <1>: PEP 530 Asynchronous Comprehensions. (line 19) * Python Enhancement Proposals; PEP 530 <2>: Displays for lists sets and dictionaries. (line 53) * Python Enhancement Proposals; PEP 538: PEP 538 Legacy C Locale Coercion. (line 11) * Python Enhancement Proposals; PEP 538 <1>: PEP 538 Legacy C Locale Coercion. (line 36) * Python Enhancement Proposals; PEP 538 <2>: PEP 538 Legacy C Locale Coercion. (line 48) * Python Enhancement Proposals; PEP 538 <3>: PEP 540 Forced UTF-8 Runtime Mode. (line 27) * Python Enhancement Proposals; PEP 538 <4>: Environment variables. (line 376) * Python Enhancement Proposals; PEP 538 <5>: Python Configuration. (line 13) * Python Enhancement Proposals; PEP 539: PEP 539 New C API for Thread-Local Storage. (line 12) * Python Enhancement Proposals; PEP 539 <1>: PEP 539 New C API for Thread-Local Storage. (line 30) * Python Enhancement Proposals; PEP 539 <2>: Thread Specific Storage TSS API. (line 15) * Python Enhancement Proposals; PEP 540: PEP 540 Forced UTF-8 Runtime Mode. (line 18) * Python Enhancement Proposals; PEP 540 <1>: PEP 540 Forced UTF-8 Runtime Mode. (line 35) * Python Enhancement Proposals; PEP 540 <2>: Environment variables. (line 445) * Python Enhancement Proposals; PEP 540 <3>: Python Configuration. (line 13) * Python Enhancement Proposals; PEP 544: typing. (line 32) * Python Enhancement Proposals; PEP 544 <1>: typing — Support for type hints. (line 17) * Python Enhancement Proposals; PEP 544 <2>: Nominal vs structural subtyping. (line 23) * Python Enhancement Proposals; PEP 544 <3>: Classes functions and decorators. (line 92) * Python Enhancement Proposals; PEP 545: PEP 545 Python Documentation Translations. (line 6) * Python Enhancement Proposals; PEP 545 <1>: PEP 545 Python Documentation Translations. (line 20) * Python Enhancement Proposals; PEP 552: PEP 552 Hash-based pyc Files. (line 15) * Python Enhancement Proposals; PEP 552 <1>: PEP 552 Hash-based pyc Files. (line 35) * Python Enhancement Proposals; PEP 552 <2>: Introduction<12>. (line 73) * Python Enhancement Proposals; PEP 552 <3>: py_compile — Compile Python source files. (line 81) * Python Enhancement Proposals; PEP 552 <4>: PyConfig. (line 137) * Python Enhancement Proposals; PEP 553: PEP 553 Built-in breakpoint. (line 20) * Python Enhancement Proposals; PEP 557: dataclasses. (line 26) * Python Enhancement Proposals; PEP 557 <1>: dataclasses — Data Classes. (line 13) * Python Enhancement Proposals; PEP 560: PEP 560 Core Support for typing module and Generic Types. (line 19) * Python Enhancement Proposals; PEP 560 <1>: types. (line 12) * Python Enhancement Proposals; PEP 560 <2>: Resolving MRO entries. (line 15) * Python Enhancement Proposals; PEP 560 <3>: Emulating generic types. (line 22) * Python Enhancement Proposals; PEP 560 <4>: Dynamic Type Creation. (line 60) * Python Enhancement Proposals; PEP 560 <5>: Dynamic Type Creation. (line 74) * Python Enhancement Proposals; PEP 562: PEP 562 Customization of Access to Module Attributes. (line 16) * Python Enhancement Proposals; PEP 562 <1>: Customizing module attribute access. (line 52) * Python Enhancement Proposals; PEP 563: PEP 563 Postponed Evaluation of Annotations. (line 51) * Python Enhancement Proposals; PEP 563 <1>: Future statements. (line 34) * Python Enhancement Proposals; PEP 563 <2>: Function definitions. (line 136) * Python Enhancement Proposals; PEP 563 <3>: __future__ — Future statement definitions. (line 97) * Python Enhancement Proposals; PEP 564: PEP 564 New Time Functions With Nanosecond Resolution. (line 8) * Python Enhancement Proposals; PEP 564 <1>: PEP 564 New Time Functions With Nanosecond Resolution. (line 33) * Python Enhancement Proposals; PEP 564 <2>: time<2>. (line 6) * Python Enhancement Proposals; PEP 565: PEP 565 Show DeprecationWarning in __main__. (line 41) * Python Enhancement Proposals; PEP 566: Using importlib metadata. (line 20) * Python Enhancement Proposals; PEP 566 <1>: Distributions. (line 28) * Python Enhancement Proposals; PEP 567: contextvars. (line 20) * Python Enhancement Proposals; PEP 567 <1>: asyncio<2>. (line 19) * Python Enhancement Proposals; PEP 567 <2>: contextvars — Context Variables. (line 18) * Python Enhancement Proposals; PEP 567 <3>: Scheduling callbacks. (line 32) * Python Enhancement Proposals; PEP 567 <4>: Scheduling delayed callbacks. (line 31) * Python Enhancement Proposals; PEP 567 <5>: Scheduling delayed callbacks. (line 49) * Python Enhancement Proposals; PEP 567 <6>: Future Object. (line 100) * Python Enhancement Proposals; PEP 570: Positional-only parameters. (line 70) * Python Enhancement Proposals; PEP 570 <1>: Changes in the Python API. (line 159) * Python Enhancement Proposals; PEP 572: Assignment expressions. (line 41) * Python Enhancement Proposals; PEP 572 <1>: CPython bytecode changes. (line 28) * Python Enhancement Proposals; PEP 572 <2>: Dictionary displays. (line 47) * Python Enhancement Proposals; PEP 572 <3>: Assignment expressions<2>. (line 22) * Python Enhancement Proposals; PEP 572 <4>: Why can’t I use an assignment in an expression?. (line 14) * Python Enhancement Proposals; PEP 574: Pickle protocol 5 with out-of-band data buffers. (line 17) * Python Enhancement Proposals; PEP 574 <1>: Data stream format. (line 46) * Python Enhancement Proposals; PEP 574 <2>: Example<4>. (line 63) * Python Enhancement Proposals; PEP 578: PEP 578 Python Runtime Audit Hooks. (line 12) * Python Enhancement Proposals; PEP 578 <1>: sys — System-specific parameters and functions. (line 44) * Python Enhancement Proposals; PEP 578 <2>: System Functions. (line 153) * Python Enhancement Proposals; PEP 586: typing. (line 18) * Python Enhancement Proposals; PEP 586 <1>: typing — Support for type hints. (line 17) * Python Enhancement Proposals; PEP 586 <2>: Classes functions and decorators. (line 898) * Python Enhancement Proposals; PEP 587: PEP 587 Python Initialization Configuration. (line 6) * Python Enhancement Proposals; PEP 587 <1>: PEP 587 Python Initialization Configuration. (line 83) * Python Enhancement Proposals; PEP 587 <2>: Python Initialization Configuration. (line 81) * Python Enhancement Proposals; PEP 589: typing. (line 8) * Python Enhancement Proposals; PEP 589 <1>: typing — Support for type hints. (line 17) * Python Enhancement Proposals; PEP 589 <2>: Classes functions and decorators. (line 592) * Python Enhancement Proposals; PEP 590: Vectorcall a fast calling protocol for CPython. (line 14) * Python Enhancement Proposals; PEP 591: typing. (line 25) * Python Enhancement Proposals; PEP 591 <1>: typing — Support for type hints. (line 17) * Python Enhancement Proposals; PEP 591 <2>: Classes functions and decorators. (line 711) * Python Enhancement Proposals; PEP 591 <3>: Classes functions and decorators. (line 945) * Python Enhancement Proposals; PEP 6: How does the Python version numbering scheme work?. (line 9) * Python Enhancement Proposals; PEP 602: How stable is Python?. (line 8) * Python Enhancement Proposals; PEP 623: Unicode Objects. (line 33) * Python Enhancement Proposals; PEP 628: cmath. (line 7) * Python Enhancement Proposals; PEP 628 <1>: math<3>. (line 7) * Python Enhancement Proposals; PEP 7: Build and C API Changes<2>. (line 9) * Python Enhancement Proposals; PEP 7 <1>: Coding standards. (line 7) * Python Enhancement Proposals; PEP 7 <2>: Useful macros. (line 87) * Python Enhancement Proposals; PEP 7 <3>: Useful macros. (line 105) * Python Enhancement Proposals; PEP 8: Library Changes. (line 26) * Python Enhancement Proposals; PEP 8 <1>: Intermezzo Coding Style. (line 13) * Python Enhancement Proposals; PEP 8 <2>: Editors and IDEs. (line 7) * Python Enhancement Proposals; PEP 8 <3>: Value comparisons. (line 61) * Python Enhancement Proposals; PEP 8 <4>: Using real Argument Clinic converters instead of “legacy converters”. (line 50) * Python Enhancement Proposals; PEP 8 <5>: Are there coding standards or a style guide for Python programs?. (line 7) * Python Enhancement Proposals; PEP 8 <6>: How do I keep editors from inserting tabs into my Python source?. (line 6) * Python Package Index (PyPI): Installing the tools. (line 26) * PYTHON*: Other Improvements<2>. (line 9) * PYTHON* <1>: Interface options. (line 80) * PYTHON* <2>: Interface options. (line 140) * PYTHON* <3>: Miscellaneous options. (line 42) * PYTHON* <4>: Miscellaneous options. (line 60) * PYTHON* <5>: Global configuration variables. (line 56) * PYTHONASYNCIODEBUG: Enabling debug mode. (line 10) * PYTHONASYNCIODEBUG <1>: Debug Mode. (line 11) * PYTHONBREAKPOINT: PEP 553 Built-in breakpoint. (line 13) * PYTHONBREAKPOINT <1>: sys — System-specific parameters and functions. (line 202) * PYTHONBREAKPOINT <2>: sys — System-specific parameters and functions. (line 216) * PYTHONBREAKPOINT <3>: sys — System-specific parameters and functions. (line 220) * PYTHONCASEOK: PEP 235 Importing Modules on Case-Insensitive Platforms. (line 17) * PYTHONCOERCECLOCALE: PEP 538 Legacy C Locale Coercion. (line 13) * PYTHONCOERCECLOCALE <1>: Environment variables. (line 438) * PYTHONCOERCECLOCALE <2>: Python Configuration. (line 15) * PYTHONDEBUG: Miscellaneous options. (line 38) * PYTHONDEBUG <1>: Global configuration variables. (line 28) * PYTHONDEVMODE: Development Runtime Mode -X dev. (line 6) * PYTHONDEVMODE <1>: test support script_helper — Utilities for the Python execution tests. (line 106) * PYTHONDOCS: pydoc — Documentation generator and online help system. (line 85) * PYTHONDONTWRITEBYTECODE: Interpreter Changes<2>. (line 16) * PYTHONDONTWRITEBYTECODE <1>: New and Improved Modules<2>. (line 625) * PYTHONDONTWRITEBYTECODE <2>: Miscellaneous options. (line 19) * PYTHONDONTWRITEBYTECODE <3>: sys — System-specific parameters and functions. (line 285) * PYTHONDONTWRITEBYTECODE <4>: Global configuration variables. (line 36) * PYTHONDONTWRITEBYTECODE <5>: How do I create a pyc file?. (line 21) * PYTHONDUMPREFS: Debug build uses the same ABI as release build. (line 14) * PYTHONDUMPREFS <1>: PyObject Slots. (line 24) * PYTHONFAULTHANDLER: faulthandler<3>. (line 11) * PYTHONFAULTHANDLER <1>: faulthandler — Dump the Python traceback. (line 14) * PYTHONHASHSEED: Builtin functions and types. (line 17) * PYTHONHASHSEED <1>: Porting Python code. (line 6) * PYTHONHASHSEED <2>: Miscellaneous options. (line 94) * PYTHONHASHSEED <3>: Miscellaneous options. (line 110) * PYTHONHASHSEED <4>: Environment variables. (line 129) * PYTHONHASHSEED <5>: Basic customization. (line 298) * PYTHONHASHSEED <6>: Global configuration variables. (line 48) * PYTHONHASHSEED <7>: Global configuration variables. (line 51) * PYTHONHOME: Summary – Release highlights<2>. (line 107) * PYTHONHOME <1>: Miscellaneous options. (line 43) * PYTHONHOME <2>: Environment variables. (line 19) * PYTHONHOME <3>: Environment variables. (line 21) * PYTHONHOME <4>: Environment variables. (line 38) * PYTHONHOME <5>: Finding modules. (line 50) * PYTHONHOME <6>: Finding modules. (line 68) * PYTHONHOME <7>: Finding modules. (line 102) * PYTHONHOME <8>: test support script_helper — Utilities for the Python execution tests. (line 25) * PYTHONHOME <9>: Embedding Python<2>. (line 38) * PYTHONHOME <10>: Embedding Python<2>. (line 44) * PYTHONHOME <11>: Global configuration variables. (line 57) * PYTHONHOME <12>: Process-wide parameters. (line 270) * PYTHONHOME <13>: Process-wide parameters. (line 284) * PYTHONHOME <14>: PyConfig. (line 197) * PYTHONHOME <15>: Modifying Python’s Search Path. (line 60) * PYTHONHOME <16>: Modifying Python’s Search Path. (line 62) * Pythonic: Glossary. (line 1081) * PYTHONINSPECT: Other Changes and Fixes<2>. (line 13) * PYTHONINSPECT <1>: Miscellaneous options. (line 53) * PYTHONINSPECT <2>: Global configuration variables. (line 68) * PYTHONIOENCODING: Other Improvements<2>. (line 75) * PYTHONIOENCODING <1>: Interpreter Changes<2>. (line 23) * PYTHONIOENCODING <2>: Environment variables. (line 359) * PYTHONIOENCODING <3>: Environment variables. (line 426) * PYTHONIOENCODING <4>: sys — System-specific parameters and functions. (line 1503) * PYTHONIOENCODING <5>: Process-wide parameters. (line 14) * PYTHONIOENCODING <6>: Process-wide parameters. (line 18) * PYTHONLEGACYWINDOWSFSENCODING: PEP 529 Change Windows filesystem encoding to UTF-8. (line 18) * PYTHONLEGACYWINDOWSFSENCODING <1>: sys — System-specific parameters and functions. (line 1455) * PYTHONLEGACYWINDOWSFSENCODING <2>: Global configuration variables. (line 90) * PYTHONLEGACYWINDOWSSTDIO: PEP 528 Change Windows console encoding to UTF-8. (line 12) * PYTHONLEGACYWINDOWSSTDIO <1>: Environment variables. (line 156) * PYTHONLEGACYWINDOWSSTDIO <2>: sys — System-specific parameters and functions. (line 1507) * PYTHONLEGACYWINDOWSSTDIO <3>: Global configuration variables. (line 102) * PYTHONMALLOC: PYTHONMALLOC environment variable. (line 6) * PYTHONMALLOC <1>: Changes in the C API<3>. (line 9) * PYTHONMALLOC <2>: Environment variables. (line 286) * PYTHONMALLOC <3>: Overview<3>. (line 75) * PYTHONMALLOC <4>: Default Memory Allocators. (line 26) * PYTHONMALLOC <5>: Customize Memory Allocators. (line 129) * PYTHONMALLOCSTATS: Overview<3>. (line 78) * PYTHONNOUSERSITE: PEP 370 Per-user site-packages Directory. (line 30) * PYTHONNOUSERSITE <1>: Module contents<3>. (line 15) * PYTHONNOUSERSITE <2>: Global configuration variables. (line 124) * PYTHONOPTIMIZE: Miscellaneous options. (line 71) * PYTHONOPTIMIZE <1>: Global configuration variables. (line 129) * PYTHONPATH: Changes in ‘python’ Command Behavior<2>. (line 8) * PYTHONPATH <1>: Changes in ‘python’ Command Behavior<2>. (line 9) * PYTHONPATH <2>: The Module Search Path. (line 15) * PYTHONPATH <3>: Standard Modules. (line 34) * PYTHONPATH <4>: Standard Modules. (line 35) * PYTHONPATH <5>: Miscellaneous options. (line 42) * PYTHONPATH <6>: Environment variables. (line 32) * PYTHONPATH <7>: Environment variables. (line 39) * PYTHONPATH <8>: Environment variables. (line 42) * PYTHONPATH <9>: Excursus Setting environment variables. (line 38) * PYTHONPATH <10>: Finding modules. (line 36) * PYTHONPATH <11>: Finding modules. (line 59) * PYTHONPATH <12>: Finding modules. (line 102) * PYTHONPATH <13>: Configuration. (line 6) * PYTHONPATH <14>: Path entry finders. (line 6) * PYTHONPATH <15>: Installing your CGI script on a Unix system. (line 29) * PYTHONPATH <16>: test support script_helper — Utilities for the Python execution tests. (line 26) * PYTHONPATH <17>: sys — System-specific parameters and functions. (line 1062) * PYTHONPATH <18>: sys — System-specific parameters and functions. (line 1072) * PYTHONPATH <19>: Building C and C++ Extensions. (line 9) * PYTHONPATH <20>: Embedding Python<2>. (line 39) * PYTHONPATH <21>: Embedding Python<2>. (line 44) * PYTHONPATH <22>: Global configuration variables. (line 56) * PYTHONPATH <23>: PyConfig. (line 252) * PYTHONPATH <24>: Modifying Python’s Search Path. (line 67) * PYTHONPATH <25>: Modifying Python’s Search Path. (line 68) * PYTHONPROFILEIMPORTTIME: Other Language Changes<2>. (line 47) * PYTHONPROFILEIMPORTTIME <1>: Miscellaneous options. (line 223) * PYTHONPYCACHEPREFIX: Parallel filesystem cache for compiled bytecode files. (line 6) * PYTHONPYCACHEPREFIX <1>: Miscellaneous options. (line 257) * PYTHONPYCACHEPREFIX <2>: sys — System-specific parameters and functions. (line 303) * PYTHONSHOWALLOCCOUNT: Two new environment variables for debug mode. (line 11) * PYTHONSHOWREFCOUNT: Two new environment variables for debug mode. (line 7) * PYTHONSTARTUP: sys<6>. (line 17) * PYTHONSTARTUP <1>: sys<6>. (line 21) * PYTHONSTARTUP <2>: The Interactive Startup File. (line 8) * PYTHONSTARTUP <3>: Miscellaneous options. (line 50) * PYTHONSTARTUP <4>: Example. (line 10) * PYTHONSTARTUP <5>: Startup and code execution. (line 7) * PYTHONSTARTUP <6>: sys — System-specific parameters and functions. (line 957) * PYTHONSTARTUP <7>: Readline configuration. (line 12) * PYTHONTRACEMALLOC: tracemalloc — Trace memory allocations. (line 25) * PYTHONTRACEMALLOC <1>: tracemalloc — Trace memory allocations. (line 32) * PYTHONTRACEMALLOC <2>: Functions<9>. (line 68) * PYTHONUNBUFFERED: Miscellaneous options. (line 140) * PYTHONUNBUFFERED <1>: Global configuration variables. (line 145) * PYTHONUSERBASE: PEP 370 Per-user site-packages Directory. (line 23) * PYTHONUSERBASE <1>: Module contents<3>. (line 39) * PYTHONUSERBASE <2>: Module contents<3>. (line 66) * PYTHONUSERSITE: test support script_helper — Utilities for the Python execution tests. (line 26) * PYTHONUTF8: PEP 540 Forced UTF-8 Runtime Mode. (line 6) * PYTHONUTF8 <1>: Miscellaneous options. (line 252) * PYTHONUTF8 <2>: Environment variables. (line 369) * PYTHONUTF8 <3>: UTF-8 mode. (line 17) * PYTHONUTF8 <4>: sys — System-specific parameters and functions. (line 1505) * PYTHONUTF8 <5>: Python Configuration. (line 14) * PYTHONVERBOSE: Miscellaneous options. (line 151) * PYTHONVERBOSE <1>: Global configuration variables. (line 156) * PYTHONWARNINGS: warnings. (line 21) * PYTHONWARNINGS <1>: Other Language Changes<7>. (line 158) * PYTHONWARNINGS <2>: Changes to the Handling of Deprecation Warnings. (line 25) * PYTHONWARNINGS <3>: Interpreter Changes. (line 6) * PYTHONWARNINGS <4>: Miscellaneous options. (line 169) * PYTHONWARNINGS <5>: Describing Warning Filters. (line 7) * PYTHONWARNINGS <6>: Describing Warning Filters. (line 21) * PYTHONWARNINGS <7>: Default Warning Filter. (line 7) * python_branch() (in module platform): Cross Platform. (line 86) * python_build() (in module platform): Cross Platform. (line 76) * python_compiler() (in module platform): Cross Platform. (line 81) * PYTHON_DOM: Module Contents<4>. (line 23) * python_implementation() (in module platform): Cross Platform. (line 90) * python_is_optimized() (in module test.support): test support — Utilities for the Python test suite. (line 203) * python_revision() (in module platform): Cross Platform. (line 95) * python_version() (in module platform): Cross Platform. (line 100) * python_version_tuple() (in module platform): Cross Platform. (line 107) * PyThreadState: Thread State and the Global Interpreter Lock. (line 23) * PyThreadState <1>: Thread State and the Global Interpreter Lock. (line 23) * PyThreadState (C type): High-level API. (line 21) * PyThreadState_Clear (C function): Low-level API. (line 44) * PyThreadState_Delete (C function): Low-level API. (line 49) * PyThreadState_Get (C function): High-level API. (line 76) * PyThreadState_GetDict (C function): Low-level API. (line 78) * PyThreadState_New (C function): Low-level API. (line 37) * PyThreadState_Next (C function): Advanced Debugger Support. (line 32) * PyThreadState_SetAsyncExc (C function): Low-level API. (line 87) * PyThreadState_Swap (C function): High-level API. (line 82) * PyThread_create_key (C function): Thread Local Storage TLS API. (line 18) * PyThread_delete_key (C function): Thread Local Storage TLS API. (line 20) * PyThread_delete_key_value (C function): Thread Local Storage TLS API. (line 26) * PyThread_get_key_value (C function): Thread Local Storage TLS API. (line 24) * PyThread_ReInitTLS (C function): Thread Local Storage TLS API. (line 28) * PyThread_set_key_value (C function): Thread Local Storage TLS API. (line 22) * PyThread_tss_alloc (C function): Dynamic Allocation. (line 11) * PyThread_tss_create (C function): Methods<4>. (line 16) * PyThread_tss_delete (C function): Methods<4>. (line 24) * PyThread_tss_free (C function): Dynamic Allocation. (line 17) * PyThread_tss_get (C function): Methods<4>. (line 39) * PyThread_tss_is_created (C function): Methods<4>. (line 11) * PyThread_tss_set (C function): Methods<4>. (line 33) * PyTimeZone_FromOffset (C function): DateTime Objects<2>. (line 120) * PyTimeZone_FromOffsetAndName (C function): DateTime Objects<2>. (line 128) * PyTime_Check (C function): DateTime Objects<2>. (line 45) * PyTime_CheckExact (C function): DateTime Objects<2>. (line 50) * PyTime_FromTime (C function): DateTime Objects<2>. (line 98) * PyTime_FromTimeAndFold (C function): DateTime Objects<2>. (line 103) * PyTraceMalloc_Track (C function): tracemalloc C API. (line 8) * PyTraceMalloc_Untrack (C function): tracemalloc C API. (line 20) * PyTrace_CALL (C variable): Profiling and Tracing. (line 61) * PyTrace_C_CALL (C variable): Profiling and Tracing. (line 93) * PyTrace_C_EXCEPTION (C variable): Profiling and Tracing. (line 98) * PyTrace_C_RETURN (C variable): Profiling and Tracing. (line 103) * PyTrace_EXCEPTION (C variable): Profiling and Tracing. (line 69) * PyTrace_LINE (C variable): Profiling and Tracing. (line 81) * PyTrace_OPCODE (C variable): Profiling and Tracing. (line 108) * PyTrace_RETURN (C variable): Profiling and Tracing. (line 88) * PyTupleObject (C type): Tuple Objects. (line 6) * PyTuple_Check (C function): Tuple Objects. (line 17) * PyTuple_CheckExact (C function): Tuple Objects. (line 22) * PyTuple_ClearFreeList (C function): Tuple Objects. (line 103) * PyTuple_GetItem (C function): Tuple Objects. (line 48) * PyTuple_GetSlice (C function): Tuple Objects. (line 57) * PyTuple_GET_ITEM (C function): Tuple Objects. (line 53) * PyTuple_GET_SIZE (C function): Tuple Objects. (line 43) * PyTuple_New (C function): Tuple Objects. (line 27) * PyTuple_Pack (C function): Tuple Objects. (line 31) * PyTuple_SetItem (C function): Tuple Objects. (line 64) * PyTuple_SetItem(): Reference Count Details. (line 26) * PyTuple_SET_ITEM (C function): Tuple Objects. (line 76) * PyTuple_Size (C function): Tuple Objects. (line 38) * PyTuple_Type (C variable): Tuple Objects. (line 11) * PyTypeObject (C type): Type Objects<2>. (line 6) * PyTypeObject.tp_alloc (C member): PyTypeObject Slots. (line 1172) * PyTypeObject.tp_allocs (C member): PyTypeObject Slots. (line 1394) * PyTypeObject.tp_as_async (C member): PyTypeObject Slots. (line 240) * PyTypeObject.tp_as_buffer (C member): PyTypeObject Slots. (line 441) * PyTypeObject.tp_as_mapping (C member): PyTypeObject Slots. (line 303) * PyTypeObject.tp_as_number (C member): PyTypeObject Slots. (line 281) * PyTypeObject.tp_as_sequence (C member): PyTypeObject Slots. (line 292) * PyTypeObject.tp_base (C member): PyTypeObject Slots. (line 985) * PyTypeObject.tp_bases (C member): PyTypeObject Slots. (line 1283) * PyTypeObject.tp_basicsize (C member): PyTypeObject Slots. (line 47) * PyTypeObject.tp_cache (C member): PyTypeObject Slots. (line 1305) * PyTypeObject.tp_call (C member): PyTypeObject Slots. (line 351) * PyTypeObject.tp_clear (C member): PyTypeObject Slots. (line 722) * PyTypeObject.tp_dealloc (C member): PyTypeObject Slots. (line 99) * PyTypeObject.tp_del (C member): PyTypeObject Slots. (line 1330) * PyTypeObject.tp_descr_get (C member): PyTypeObject Slots. (line 1042) * PyTypeObject.tp_descr_set (C member): PyTypeObject Slots. (line 1054) * PyTypeObject.tp_dict (C member): PyTypeObject Slots. (line 1017) * PyTypeObject.tp_dictoffset (C member): PyTypeObject Slots. (line 1069) * PyTypeObject.tp_doc (C member): PyTypeObject Slots. (line 650) * PyTypeObject.tp_finalize (C member): PyTypeObject Slots. (line 1342) * PyTypeObject.tp_flags (C member): PyTypeObject Slots. (line 452) * PyTypeObject.tp_free (C member): PyTypeObject Slots. (line 1231) * PyTypeObject.tp_frees (C member): PyTypeObject Slots. (line 1398) * PyTypeObject.tp_getattr (C member): PyTypeObject Slots. (line 201) * PyTypeObject.tp_getattro (C member): PyTypeObject Slots. (line 389) * PyTypeObject.tp_getset (C member): PyTypeObject Slots. (line 970) * PyTypeObject.tp_hash (C member): PyTypeObject Slots. (line 314) * PyTypeObject.tp_init (C member): PyTypeObject Slots. (line 1135) * PyTypeObject.tp_is_gc (C member): PyTypeObject Slots. (line 1254) * PyTypeObject.tp_itemsize (C member): PyTypeObject Slots. (line 47) * PyTypeObject.tp_iter (C member): PyTypeObject Slots. (line 902) * PyTypeObject.tp_iternext (C member): PyTypeObject Slots. (line 918) * PyTypeObject.tp_maxalloc (C member): PyTypeObject Slots. (line 1402) * PyTypeObject.tp_members (C member): PyTypeObject Slots. (line 955) * PyTypeObject.tp_methods (C member): PyTypeObject Slots. (line 940) * PyTypeObject.tp_mro (C member): PyTypeObject Slots. (line 1294) * PyTypeObject.tp_name (C member): PyTypeObject Slots. (line 12) * PyTypeObject.tp_new (C member): PyTypeObject Slots. (line 1195) * PyTypeObject.tp_next (C member): PyTypeObject Slots. (line 1411) * PyTypeObject.tp_prev (C member): PyTypeObject Slots. (line 1406) * PyTypeObject.tp_repr (C member): PyTypeObject Slots. (line 255) * PyTypeObject.tp_richcompare (C member): PyTypeObject Slots. (line 791) * PyTypeObject.tp_setattr (C member): PyTypeObject Slots. (line 220) * PyTypeObject.tp_setattro (C member): PyTypeObject Slots. (line 414) * PyTypeObject.tp_str (C member): PyTypeObject Slots. (line 363) * PyTypeObject.tp_subclasses (C member): PyTypeObject Slots. (line 1313) * PyTypeObject.tp_traverse (C member): PyTypeObject Slots. (line 660) * PyTypeObject.tp_vectorcall_offset (C member): PyTypeObject Slots. (line 141) * PyTypeObject.tp_version_tag (C member): PyTypeObject Slots. (line 1334) * PyTypeObject.tp_weaklist (C member): PyTypeObject Slots. (line 1321) * PyTypeObject.tp_weaklistoffset (C member): PyTypeObject Slots. (line 866) * PyType_Check (C function): Type Objects<2>. (line 15) * PyType_CheckExact (C function): Type Objects<2>. (line 21) * PyType_ClearCache (C function): Type Objects<2>. (line 26) * PyType_FromSpec (C function): Creating Heap-Allocated Types. (line 26) * PyType_FromSpecWithBases (C function): Creating Heap-Allocated Types. (line 9) * PyType_GenericAlloc (C function): Type Objects<2>. (line 68) * PyType_GenericNew (C function): Type Objects<2>. (line 76) * PyType_GetFlags (C function): Type Objects<2>. (line 30) * PyType_GetSlot (C function): Type Objects<2>. (line 90) * PyType_HasFeature (C function): Type Objects<2>. (line 49) * PyType_IsSubtype (C function): Type Objects<2>. (line 59) * PyType_IS_GC (C function): Type Objects<2>. (line 54) * PyType_Modified (C function): Type Objects<2>. (line 43) * PyType_Ready (C function): Type Objects<2>. (line 83) * PyType_Slot (C type): Creating Heap-Allocated Types. (line 59) * PyType_Slot.PyType_Slot.pfunc (C member): Creating Heap-Allocated Types. (line 109) * PyType_Slot.PyType_Slot.slot (C member): Creating Heap-Allocated Types. (line 64) * PyType_Spec (C type): Creating Heap-Allocated Types. (line 30) * PyType_Spec.PyType_Spec.basicsize (C member): Creating Heap-Allocated Types. (line 39) * PyType_Spec.PyType_Spec.flags (C member): Creating Heap-Allocated Types. (line 47) * PyType_Spec.PyType_Spec.itemsize (C member): Creating Heap-Allocated Types. (line 41) * PyType_Spec.PyType_Spec.name (C member): Creating Heap-Allocated Types. (line 34) * PyType_Spec.PyType_Spec.slots (C member): Creating Heap-Allocated Types. (line 54) * PyType_Type (C variable): Type Objects<2>. (line 10) * PyTZInfo_Check (C function): DateTime Objects<2>. (line 65) * PyTZInfo_CheckExact (C function): DateTime Objects<2>. (line 70) * PyUnicodeDecodeError_Create (C function): Unicode Exception Objects. (line 9) * PyUnicodeDecodeError_GetEncoding (C function): Unicode Exception Objects. (line 47) * PyUnicodeDecodeError_GetEnd (C function): Unicode Exception Objects. (line 88) * PyUnicodeDecodeError_GetObject (C function): Unicode Exception Objects. (line 54) * PyUnicodeDecodeError_GetReason (C function): Unicode Exception Objects. (line 115) * PyUnicodeDecodeError_GetStart (C function): Unicode Exception Objects. (line 61) * PyUnicodeDecodeError_SetEnd (C function): Unicode Exception Objects. (line 102) * PyUnicodeDecodeError_SetReason (C function): Unicode Exception Objects. (line 122) * PyUnicodeDecodeError_SetStart (C function): Unicode Exception Objects. (line 75) * PyUnicodeEncodeError_Create (C function): Unicode Exception Objects. (line 18) * PyUnicodeEncodeError_GetEncoding (C function): Unicode Exception Objects. (line 47) * PyUnicodeEncodeError_GetEnd (C function): Unicode Exception Objects. (line 88) * PyUnicodeEncodeError_GetObject (C function): Unicode Exception Objects. (line 54) * PyUnicodeEncodeError_GetReason (C function): Unicode Exception Objects. (line 115) * PyUnicodeEncodeError_GetStart (C function): Unicode Exception Objects. (line 61) * PyUnicodeEncodeError_SetEnd (C function): Unicode Exception Objects. (line 102) * PyUnicodeEncodeError_SetReason (C function): Unicode Exception Objects. (line 122) * PyUnicodeEncodeError_SetStart (C function): Unicode Exception Objects. (line 75) * PyUnicodeObject (C type): Unicode Type. (line 29) * PyUnicodeTranslateError_Create (C function): Unicode Exception Objects. (line 32) * PyUnicodeTranslateError_GetEnd (C function): Unicode Exception Objects. (line 88) * PyUnicodeTranslateError_GetObject (C function): Unicode Exception Objects. (line 54) * PyUnicodeTranslateError_GetReason (C function): Unicode Exception Objects. (line 115) * PyUnicodeTranslateError_GetStart (C function): Unicode Exception Objects. (line 61) * PyUnicodeTranslateError_SetEnd (C function): Unicode Exception Objects. (line 102) * PyUnicodeTranslateError_SetReason (C function): Unicode Exception Objects. (line 122) * PyUnicodeTranslateError_SetStart (C function): Unicode Exception Objects. (line 75) * PyUnicode_1BYTE_DATA (C function): Unicode Type. (line 80) * PyUnicode_1BYTE_KIND (C macro): Unicode Type. (line 93) * PyUnicode_2BYTE_DATA (C function): Unicode Type. (line 80) * PyUnicode_2BYTE_KIND (C macro): Unicode Type. (line 93) * PyUnicode_4BYTE_DATA (C function): Unicode Type. (line 80) * PyUnicode_4BYTE_KIND (C macro): Unicode Type. (line 93) * PyUnicode_AsASCIIString (C function): ASCII Codecs. (line 16) * PyUnicode_AsCharmapString (C function): Character Map Codecs. (line 30) * PyUnicode_AsEncodedString (C function): Generic Codecs. (line 17) * PyUnicode_AsLatin1String (C function): Latin-1 Codecs. (line 17) * PyUnicode_AsMBCSString (C function): MBCS codecs for Windows. (line 28) * PyUnicode_AsRawUnicodeEscapeString (C function): Raw-Unicode-Escape Codecs. (line 14) * PyUnicode_AsUCS4 (C function): Creating and accessing Unicode strings. (line 251) * PyUnicode_AsUCS4Copy (C function): Creating and accessing Unicode strings. (line 261) * PyUnicode_AsUnicode (C function): Deprecated Py_UNICODE APIs. (line 35) * PyUnicode_AsUnicodeAndSize (C function): Deprecated Py_UNICODE APIs. (line 63) * PyUnicode_AsUnicodeCopy (C function): Deprecated Py_UNICODE APIs. (line 79) * PyUnicode_AsUnicodeEscapeString (C function): Unicode-Escape Codecs. (line 15) * PyUnicode_AsUTF16String (C function): UTF-16 Codecs. (line 50) * PyUnicode_AsUTF32String (C function): UTF-32 Codecs. (line 49) * PyUnicode_AsUTF8 (C function): UTF-8 Codecs. (line 53) * PyUnicode_AsUTF8AndSize (C function): UTF-8 Codecs. (line 30) * PyUnicode_AsUTF8String (C function): UTF-8 Codecs. (line 25) * PyUnicode_AsWideChar (C function): wchar_t Support. (line 16) * PyUnicode_AsWideCharString (C function): wchar_t Support. (line 31) * PyUnicode_AS_DATA (C function): Unicode Type. (line 186) * PyUnicode_AS_UNICODE (C function): Unicode Type. (line 186) * PyUnicode_Check (C function): Unicode Type. (line 48) * PyUnicode_CheckExact (C function): Unicode Type. (line 53) * PyUnicode_ClearFreeList (C function): Unicode Type. (line 162) * PyUnicode_Compare (C function): Methods and Slot Functions. (line 87) * PyUnicode_CompareWithASCIIString (C function): Methods and Slot Functions. (line 95) * PyUnicode_Concat (C function): Methods and Slot Functions. (line 12) * PyUnicode_Contains (C function): Methods and Slot Functions. (line 126) * PyUnicode_CopyCharacters (C function): Creating and accessing Unicode strings. (line 190) * PyUnicode_Count (C function): Methods and Slot Functions. (line 74) * PyUnicode_DATA (C function): Unicode Type. (line 114) * PyUnicode_Decode (C function): Generic Codecs. (line 8) * PyUnicode_DecodeASCII (C function): ASCII Codecs. (line 9) * PyUnicode_DecodeCharmap (C function): Character Map Codecs. (line 15) * PyUnicode_DecodeFSDefault (C function): File System Encoding. (line 65) * PyUnicode_DecodeFSDefaultAndSize (C function): File System Encoding. (line 43) * PyUnicode_DecodeLatin1 (C function): Latin-1 Codecs. (line 10) * PyUnicode_DecodeLocale (C function): Locale Encoding. (line 37) * PyUnicode_DecodeLocaleAndSize (C function): Locale Encoding. (line 9) * PyUnicode_DecodeMBCS (C function): MBCS codecs for Windows. (line 12) * PyUnicode_DecodeMBCSStateful (C function): MBCS codecs for Windows. (line 19) * PyUnicode_DecodeRawUnicodeEscape (C function): Raw-Unicode-Escape Codecs. (line 8) * PyUnicode_DecodeUnicodeEscape (C function): Unicode-Escape Codecs. (line 8) * PyUnicode_DecodeUTF16 (C function): UTF-16 Codecs. (line 8) * PyUnicode_DecodeUTF16Stateful (C function): UTF-16 Codecs. (line 37) * PyUnicode_DecodeUTF32 (C function): UTF-32 Codecs. (line 8) * PyUnicode_DecodeUTF32Stateful (C function): UTF-32 Codecs. (line 36) * PyUnicode_DecodeUTF7 (C function): UTF-7 Codecs. (line 8) * PyUnicode_DecodeUTF7Stateful (C function): UTF-7 Codecs. (line 15) * PyUnicode_DecodeUTF8 (C function): UTF-8 Codecs. (line 8) * PyUnicode_DecodeUTF8Stateful (C function): UTF-8 Codecs. (line 15) * PyUnicode_Encode (C function): Generic Codecs. (line 26) * PyUnicode_EncodeASCII (C function): ASCII Codecs. (line 21) * PyUnicode_EncodeCharmap (C function): Character Map Codecs. (line 44) * PyUnicode_EncodeCodePage (C function): MBCS codecs for Windows. (line 33) * PyUnicode_EncodeFSDefault (C function): File System Encoding. (line 79) * PyUnicode_EncodeLatin1 (C function): Latin-1 Codecs. (line 23) * PyUnicode_EncodeLocale (C function): Locale Encoding. (line 45) * PyUnicode_EncodeMBCS (C function): MBCS codecs for Windows. (line 43) * PyUnicode_EncodeRawUnicodeEscape (C function): Raw-Unicode-Escape Codecs. (line 21) * PyUnicode_EncodeUnicodeEscape (C function): Unicode-Escape Codecs. (line 22) * PyUnicode_EncodeUTF16 (C function): UTF-16 Codecs. (line 56) * PyUnicode_EncodeUTF32 (C function): UTF-32 Codecs. (line 55) * PyUnicode_EncodeUTF7 (C function): UTF-7 Codecs. (line 25) * PyUnicode_EncodeUTF8 (C function): UTF-8 Codecs. (line 63) * PyUnicode_Fill (C function): Creating and accessing Unicode strings. (line 203) * PyUnicode_Find (C function): Methods and Slot Functions. (line 48) * PyUnicode_FindChar (C function): Methods and Slot Functions. (line 59) * PyUnicode_Format (C function): Methods and Slot Functions. (line 121) * PyUnicode_FromEncodedObject (C function): Creating and accessing Unicode strings. (line 167) * PyUnicode_FromFormat (C function): Creating and accessing Unicode strings. (line 50) * PyUnicode_FromFormatV (C function): Creating and accessing Unicode strings. (line 160) * PyUnicode_FromKindAndData (C function): Creating and accessing Unicode strings. (line 21) * PyUnicode_FromObject (C function): Deprecated Py_UNICODE APIs. (line 104) * PyUnicode_FromString (C function): Creating and accessing Unicode strings. (line 46) * PyUnicode_FromString(): Dictionary Objects. (line 64) * PyUnicode_FromStringAndSize (C function): Creating and accessing Unicode strings. (line 32) * PyUnicode_FromUnicode (C function): Deprecated Py_UNICODE APIs. (line 13) * PyUnicode_FromWideChar (C function): wchar_t Support. (line 8) * PyUnicode_FSConverter (C function): File System Encoding. (line 13) * PyUnicode_FSDecoder (C function): File System Encoding. (line 30) * PyUnicode_GetLength (C function): Creating and accessing Unicode strings. (line 184) * PyUnicode_GetSize (C function): Deprecated Py_UNICODE APIs. (line 94) * PyUnicode_GET_DATA_SIZE (C function): Unicode Type. (line 176) * PyUnicode_GET_LENGTH (C function): Unicode Type. (line 72) * PyUnicode_GET_SIZE (C function): Unicode Type. (line 166) * PyUnicode_InternFromString (C function): Methods and Slot Functions. (line 148) * PyUnicode_InternInPlace (C function): Methods and Slot Functions. (line 135) * PyUnicode_Join (C function): Methods and Slot Functions. (line 34) * PyUnicode_KIND (C function): Unicode Type. (line 105) * PyUnicode_MAX_CHAR_VALUE (C macro): Unicode Type. (line 153) * PyUnicode_New (C function): Creating and accessing Unicode strings. (line 9) * PyUnicode_READ (C function): Unicode Type. (line 134) * PyUnicode_ReadChar (C function): Creating and accessing Unicode strings. (line 232) * PyUnicode_READY (C function): Unicode Type. (line 58) * PyUnicode_READ_CHAR (C function): Unicode Type. (line 144) * PyUnicode_Replace (C function): Methods and Slot Functions. (line 80) * PyUnicode_RichCompare (C function): Methods and Slot Functions. (line 106) * PyUnicode_Split (C function): Methods and Slot Functions. (line 17) * PyUnicode_Splitlines (C function): Methods and Slot Functions. (line 27) * PyUnicode_Substring (C function): Creating and accessing Unicode strings. (line 242) * PyUnicode_Tailmatch (C function): Methods and Slot Functions. (line 39) * PyUnicode_TransformDecimalToASCII (C function): Deprecated Py_UNICODE APIs. (line 52) * PyUnicode_Translate (C function): Character Map Codecs. (line 59) * PyUnicode_TranslateCharmap (C function): Character Map Codecs. (line 76) * PyUnicode_Type (C variable): Unicode Type. (line 40) * PyUnicode_WCHAR_KIND (C macro): Unicode Type. (line 93) * PyUnicode_WRITE (C function): Unicode Type. (line 121) * PyUnicode_WriteChar (C function): Creating and accessing Unicode strings. (line 218) * PyVarObject (C type): Common Object Structures. (line 28) * PyVarObject.ob_size (C member): PyVarObject Slots. (line 6) * PyVarObject_HEAD_INIT (C macro): Common Object Structures. (line 86) * PyVectorcall_Call (C function): PyTypeObject Slots. (line 164) * PyVectorcall_NARGS (C function): Object Protocol. (line 395) * PyWeakref_Check (C function): Weak Reference Objects<2>. (line 11) * PyWeakref_CheckProxy (C function): Weak Reference Objects<2>. (line 19) * PyWeakref_CheckRef (C function): Weak Reference Objects<2>. (line 15) * PyWeakref_GetObject (C function): Weak Reference Objects<2>. (line 50) * PyWeakref_GET_OBJECT (C function): Weak Reference Objects<2>. (line 60) * PyWeakref_NewProxy (C function): Weak Reference Objects<2>. (line 36) * PyWeakref_NewRef (C function): Weak Reference Objects<2>. (line 23) * PyWideStringList (C type): PyWideStringList. (line 6) * PyWideStringList.items (C member): PyWideStringList. (line 41) * PyWideStringList.length (C member): PyWideStringList. (line 37) * PyWideStringList_Append (C function): PyWideStringList. (line 15) * PyWideStringList_Insert (C function): PyWideStringList. (line 22) * PyWrapper_New (C function): Descriptor Objects. (line 43) * PyZipFile (class in zipfile): PyZipFile Objects. (line 10) * Py_ABS (C macro): Useful macros. (line 21) * Py_AddPendingCall (C function): Asynchronous Notifications. (line 10) * Py_AddPendingCall(): Asynchronous Notifications. (line 12) * Py_AtExit (C function): Process Control. (line 24) * Py_BEGIN_ALLOW_THREADS: Releasing the GIL from extension code. (line 21) * Py_BEGIN_ALLOW_THREADS (C macro): High-level API. (line 158) * Py_BLOCK_THREADS (C macro): High-level API. (line 172) * Py_buffer (C type): Buffer structure. (line 25) * Py_buffer.buf (C member): Buffer structure. (line 27) * Py_buffer.format (C member): Buffer structure. (line 87) * Py_buffer.internal (C member): Buffer structure. (line 154) * Py_buffer.itemsize (C member): Buffer structure. (line 67) * Py_buffer.len (C member): Buffer structure. (line 50) * Py_buffer.ndim (C member): Buffer structure. (line 96) * Py_buffer.obj (C member): Buffer structure. (line 38) * Py_buffer.readonly (C member): Buffer structure. (line 62) * Py_buffer.shape (C member): Buffer structure. (line 109) * Py_buffer.strides (C member): Buffer structure. (line 122) * Py_buffer.suboffsets (C member): Buffer structure. (line 135) * Py_BuildValue (C function): Building values. (line 6) * Py_BytesMain (C function): The Very High Level Layer. (line 41) * Py_BytesWarningFlag (C variable): Global configuration variables. (line 15) * Py_CHARMASK (C macro): Useful macros. (line 52) * Py_CLEAR (C function): Reference Counting. (line 47) * py_compile (module): py_compile — Compile Python source files. (line 6) * PY_COMPILED (in module imp): imp — Access the import internals. (line 315) * Py_CompileString (C function): The Very High Level Layer. (line 286) * Py_CompileString(): The Very High Level Layer. (line 380) * Py_CompileString() <1>: The Very High Level Layer. (line 385) * Py_CompileString() <2>: The Very High Level Layer. (line 392) * Py_CompileStringExFlags (C function): The Very High Level Layer. (line 320) * Py_CompileStringFlags (C function): The Very High Level Layer. (line 292) * Py_CompileStringObject (C function): The Very High Level Layer. (line 299) * Py_complex (C type): Complex Numbers as C Structures. (line 10) * Py_DebugFlag (C variable): Global configuration variables. (line 23) * Py_DecodeLocale (C function): Operating System Utilities. (line 108) * Py_DECREF (C function): Reference Counting. (line 20) * Py_DECREF(): Reference Counts<2>. (line 17) * Py_DEPRECATED (C macro): Useful macros. (line 70) * Py_DontWriteBytecodeFlag (C variable): Global configuration variables. (line 31) * Py_Ellipsis (C variable): Ellipsis Object. (line 6) * Py_EncodeLocale (C function): Operating System Utilities. (line 161) * Py_EndInterpreter (C function): Sub-interpreter support. (line 76) * Py_END_ALLOW_THREADS: Releasing the GIL from extension code. (line 21) * Py_END_ALLOW_THREADS (C macro): High-level API. (line 165) * Py_EnterRecursiveCall (C function): Recursion Control. (line 11) * Py_eval_input (C variable): The Very High Level Layer. (line 378) * Py_Exit (C function): Process Control. (line 15) * Py_ExitStatusException (C function): PyStatus. (line 62) * Py_False (C variable): Boolean Objects. (line 15) * Py_FatalError (C function): Process Control. (line 6) * Py_FatalError(): Process-wide parameters. (line 217) * Py_FdIsInteractive (C function): Operating System Utilities. (line 17) * Py_file_input (C variable): The Very High Level Layer. (line 383) * Py_Finalize (C function): Initializing and finalizing the interpreter. (line 78) * Py_FinalizeEx (C function): Initializing and finalizing the interpreter. (line 39) * Py_FinalizeEx(): Process Control. (line 17) * Py_FinalizeEx() <1>: Process Control. (line 26) * Py_FinalizeEx() <2>: Initializing and finalizing the interpreter. (line 8) * Py_FinalizeEx() <3>: Sub-interpreter support. (line 49) * Py_FinalizeEx() <4>: Sub-interpreter support. (line 78) * PY_FROZEN (in module imp): imp — Access the import internals. (line 339) * Py_FrozenFlag (C variable): Global configuration variables. (line 39) * Py_GetBuildInfo (C function): Process-wide parameters. (line 203) * Py_GetCompiler (C function): Process-wide parameters. (line 192) * Py_GetCopyright (C function): Process-wide parameters. (line 181) * Py_GETENV (C macro): Useful macros. (line 57) * Py_GetExecPrefix (C function): Process-wide parameters. (line 71) * Py_GetExecPrefix(): Embedding Python<2>. (line 42) * Py_GetPath (C function): Process-wide parameters. (line 118) * Py_GetPath(): Embedding Python<2>. (line 42) * Py_GetPath() <1>: Process-wide parameters. (line 36) * Py_GetPath() <2>: Process-wide parameters. (line 133) * Py_GetPlatform (C function): Process-wide parameters. (line 170) * Py_GetPrefix (C function): Process-wide parameters. (line 57) * Py_GetPrefix(): Embedding Python<2>. (line 42) * Py_GetProgramFullPath (C function): Process-wide parameters. (line 109) * Py_GetProgramFullPath(): Embedding Python<2>. (line 42) * Py_GetProgramName (C function): Process-wide parameters. (line 51) * Py_GetPythonHome (C function): Process-wide parameters. (line 281) * Py_GetVersion (C function): Process-wide parameters. (line 157) * Py_HashRandomizationFlag (C variable): Global configuration variables. (line 46) * Py_IgnoreEnvironmentFlag (C variable): Global configuration variables. (line 54) * Py_INCREF (C function): Reference Counting. (line 9) * Py_INCREF(): Reference Counts<2>. (line 17) * Py_Initialize (C function): Initializing and finalizing the interpreter. (line 6) * Py_Initialize(): Embedding Python<2>. (line 12) * Py_Initialize() <1>: Process-wide parameters. (line 9) * Py_Initialize() <2>: Process-wide parameters. (line 36) * Py_Initialize() <3>: Sub-interpreter support. (line 49) * Py_InitializeEx (C function): Initializing and finalizing the interpreter. (line 26) * Py_InitializeFromConfig (C function): Initialization with PyConfig. (line 8) * Py_InspectFlag (C variable): Global configuration variables. (line 61) * Py_InteractiveFlag (C variable): Global configuration variables. (line 71) * Py_IsInitialized (C function): Initializing and finalizing the interpreter. (line 32) * Py_IsInitialized(): Embedding Python<2>. (line 51) * Py_IsolatedFlag (C variable): Global configuration variables. (line 75) * Py_LeaveRecursiveCall (C function): Recursion Control. (line 29) * Py_LegacyWindowsFSEncodingFlag (C variable): Global configuration variables. (line 85) * Py_LegacyWindowsStdioFlag (C variable): Global configuration variables. (line 97) * Py_Main (C function): The Very High Level Layer. (line 24) * Py_MAX (C macro): Useful macros. (line 33) * Py_MEMBER_SIZE (C macro): Useful macros. (line 46) * Py_MIN (C macro): Useful macros. (line 27) * Py_mod_create (C macro): Multi-phase initialization. (line 61) * Py_mod_exec (C macro): Multi-phase initialization. (line 96) * Py_NewInterpreter (C function): Sub-interpreter support. (line 24) * Py_None (C variable): The None Object. (line 11) * Py_NoSiteFlag (C variable): Global configuration variables. (line 109) * Py_NotImplemented (C variable): Object Protocol. (line 6) * Py_NoUserSiteDirectory (C variable): Global configuration variables. (line 119) * py_object (class in ctypes): Fundamental data types<2>. (line 213) * Py_OptimizeFlag (C variable): Global configuration variables. (line 127) * Py_PreInitialize (C function): Preinitialization with PyPreConfig. (line 8) * Py_PreInitializeFromArgs (C function): Preinitialization with PyPreConfig. (line 19) * Py_PreInitializeFromBytesArgs (C function): Preinitialization with PyPreConfig. (line 12) * Py_PRINT_RAW: File Objects. (line 87) * PY_PYTHON: Customizing default Python versions. (line 18) * Py_QuietFlag (C variable): Global configuration variables. (line 132) * Py_REFCNT (C macro): Common Object Structures. (line 64) * Py_ReprEnter (C function): Recursion Control. (line 41) * Py_ReprLeave (C function): Recursion Control. (line 59) * Py_RETURN_FALSE (C macro): Boolean Objects. (line 27) * Py_RETURN_NONE (C macro): The None Object. (line 17) * Py_RETURN_NOTIMPLEMENTED (C macro): Object Protocol. (line 11) * Py_RETURN_RICHCOMPARE (C macro): PyTypeObject Slots. (line 835) * Py_RETURN_TRUE (C macro): Boolean Objects. (line 32) * Py_RunMain (C function): Py_RunMain. (line 6) * Py_SetPath (C function): Process-wide parameters. (line 131) * Py_SetPath(): Process-wide parameters. (line 120) * Py_SetProgramName (C function): Process-wide parameters. (line 34) * Py_SetProgramName(): Embedding Python<2>. (line 42) * Py_SetProgramName() <1>: Initializing and finalizing the interpreter. (line 8) * Py_SetProgramName() <2>: Process-wide parameters. (line 53) * Py_SetProgramName() <3>: Process-wide parameters. (line 111) * Py_SetPythonHome (C function): Process-wide parameters. (line 267) * Py_SetStandardStreamEncoding (C function): Process-wide parameters. (line 6) * Py_single_input (C variable): The Very High Level Layer. (line 390) * Py_SIZE (C macro): Common Object Structures. (line 71) * PY_SOURCE (in module imp): imp — Access the import internals. (line 309) * PY_SSIZE_T_MAX: Integer Objects. (line 188) * Py_STRINGIFY (C macro): Useful macros. (line 39) * Py_TPFLAGS_BASETYPE (built-in variable): PyTypeObject Slots. (line 507) * Py_TPFLAGS_BASE_EXC_SUBCLASS (built-in variable): PyTypeObject Slots. (line 604) * Py_TPFLAGS_BYTES_SUBCLASS (built-in variable): PyTypeObject Slots. (line 598) * Py_TPFLAGS_DEFAULT (built-in variable): PyTypeObject Slots. (line 556) * Py_TPFLAGS_DICT_SUBCLASS (built-in variable): PyTypeObject Slots. (line 602) * Py_TPFLAGS_HAVE_FINALIZE (built-in variable): PyTypeObject Slots. (line 617) * Py_TPFLAGS_HAVE_GC (built-in variable): PyTypeObject Slots. (line 535) * Py_TPFLAGS_HEAPTYPE (built-in variable): PyTypeObject Slots. (line 492) * Py_TPFLAGS_LIST_SUBCLASS (built-in variable): PyTypeObject Slots. (line 594) * Py_TPFLAGS_LONG_SUBCLASS (built-in variable): PyTypeObject Slots. (line 592) * Py_TPFLAGS_METHOD_DESCRIPTOR (built-in variable): PyTypeObject Slots. (line 568) * Py_TPFLAGS_READY (built-in variable): PyTypeObject Slots. (line 517) * Py_TPFLAGS_READYING (built-in variable): PyTypeObject Slots. (line 526) * Py_TPFLAGS_TUPLE_SUBCLASS (built-in variable): PyTypeObject Slots. (line 596) * Py_TPFLAGS_TYPE_SUBCLASS (built-in variable): PyTypeObject Slots. (line 606) * Py_TPFLAGS_UNICODE_SUBCLASS (built-in variable): PyTypeObject Slots. (line 600) * Py_tracefunc (C type): Profiling and Tracing. (line 18) * Py_True (C variable): Boolean Objects. (line 21) * Py_tss_NEEDS_INIT (C macro): Thread Specific Storage TSS API. (line 28) * Py_tss_t (C type): Thread Specific Storage TSS API. (line 17) * Py_TYPE (C macro): Common Object Structures. (line 57) * Py_UCS1 (C type): Unicode Type. (line 9) * Py_UCS2 (C type): Unicode Type. (line 9) * Py_UCS4 (C type): Unicode Type. (line 9) * Py_UNBLOCK_THREADS (C macro): High-level API. (line 178) * Py_UnbufferedStdioFlag (C variable): Global configuration variables. (line 141) * Py_UNICODE (C type): Unicode Type. (line 20) * Py_UNICODE_ISALNUM (C function): Unicode Character Properties. (line 52) * Py_UNICODE_ISALPHA (C function): Unicode Character Properties. (line 47) * Py_UNICODE_ISDECIMAL (C function): Unicode Character Properties. (line 35) * Py_UNICODE_ISDIGIT (C function): Unicode Character Properties. (line 39) * Py_UNICODE_ISLINEBREAK (C function): Unicode Character Properties. (line 30) * Py_UNICODE_ISLOWER (C function): Unicode Character Properties. (line 15) * Py_UNICODE_ISNUMERIC (C function): Unicode Character Properties. (line 43) * Py_UNICODE_ISPRINTABLE (C function): Unicode Character Properties. (line 57) * Py_UNICODE_ISSPACE (C function): Unicode Character Properties. (line 10) * Py_UNICODE_ISTITLE (C function): Unicode Character Properties. (line 25) * Py_UNICODE_ISUPPER (C function): Unicode Character Properties. (line 20) * Py_UNICODE_IS_HIGH_SURROGATE (C macro): Unicode Character Properties. (line 114) * Py_UNICODE_IS_LOW_SURROGATE (C macro): Unicode Character Properties. (line 118) * Py_UNICODE_IS_SURROGATE (C macro): Unicode Character Properties. (line 110) * Py_UNICODE_JOIN_SURROGATES (C macro): Unicode Character Properties. (line 122) * Py_UNICODE_TODECIMAL (C function): Unicode Character Properties. (line 91) * Py_UNICODE_TODIGIT (C function): Unicode Character Properties. (line 97) * Py_UNICODE_TOLOWER (C function): Unicode Character Properties. (line 70) * Py_UNICODE_TONUMERIC (C function): Unicode Character Properties. (line 103) * Py_UNICODE_TOTITLE (C function): Unicode Character Properties. (line 84) * Py_UNICODE_TOUPPER (C function): Unicode Character Properties. (line 77) * Py_UNREACHABLE (C macro): Useful macros. (line 11) * Py_UNUSED (C macro): Useful macros. (line 62) * Py_VaBuildValue (C function): Building values. (line 200) * PY_VECTORCALL_ARGUMENTS_OFFSET (C macro): Object Protocol. (line 381) * Py_VerboseFlag (C variable): Global configuration variables. (line 148) * Py_VISIT (C function): Supporting Cyclic Garbage Collection. (line 117) * Py_XDECREF (C function): Reference Counting. (line 40) * Py_XDECREF(): Exceptions<18>. (line 123) * Py_XINCREF (C function): Reference Counting. (line 15) * P_ALL (in module os): Process Management. (line 736) * P_DETACH (in module os): Process Management. (line 599) * P_NOWAIT (in module os): Process Management. (line 579) * P_NOWAITO (in module os): Process Management. (line 579) * P_OVERLAY (in module os): Process Management. (line 599) * P_PGID (in module os): Process Management. (line 736) * P_PID (in module os): Process Management. (line 736) * P_WAIT (in module os): Process Management. (line 589) * qiflush() (in module curses): Functions<3>. (line 382) * QName (class in xml.etree.ElementTree): QName Objects. (line 6) * qsize() (asyncio.Queue method): Queue. (line 74) * qsize() (multiprocessing.Queue method): Pipes and Queues. (line 98) * qsize() (queue.Queue method): Queue Objects. (line 9) * qsize() (queue.SimpleQueue method): SimpleQueue Objects. (line 9) * qualified name: Glossary. (line 1100) * quantiles() (in module statistics): Function details. (line 400) * quantiles() (statistics.NormalDist method): NormalDist objects. (line 103) * quantize() (decimal.Context method): Context objects. (line 459) * quantize() (decimal.Decimal method): Decimal objects. (line 462) * QueryInfoKey() (in module winreg): Functions<11>. (line 324) * QueryReflectionKey() (in module winreg): Functions<11>. (line 521) * QueryValue() (in module winreg): Functions<11>. (line 353) * QueryValueEx() (in module winreg): Functions<11>. (line 373) * Queue (class in asyncio): Queue. (line 6) * Queue (class in multiprocessing): Pipes and Queues. (line 84) * Queue (class in queue): queue — A synchronized queue class. (line 34) * queue (module): queue — A synchronized queue class. (line 6) * queue (sched.scheduler attribute): Scheduler Objects. (line 74) * Queue() (multiprocessing.managers.SyncManager method): Managers. (line 181) * QueueEmpty: Exceptions<8>. (line 6) * QueueFull: Exceptions<8>. (line 11) * QueueHandler (class in logging.handlers): QueueHandler. (line 21) * QueueListener (class in logging.handlers): QueueListener. (line 25) * quick_ratio() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 202) * quit (built-in variable): Constants added by the site module. (line 11) * quit (pdb command): Debugger Commands. (line 331) * quit() (ftplib.FTP method): FTP Objects. (line 237) * quit() (nntplib.NNTP method): Methods<3>. (line 22) * quit() (poplib.POP3 method): POP3 Objects. (line 82) * quit() (smtplib.SMTP method): SMTP Objects. (line 344) * quopri (module): quopri — Encode and decode MIME quoted-printable data. (line 6) * quote() (in module email.utils): email utils Miscellaneous utilities. (line 47) * quote() (in module shlex): shlex — Simple lexical analysis. (line 44) * quote() (in module urllib.parse): URL Quoting. (line 13) * quoteattr() (in module xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 34) * quotechar (csv.Dialect attribute): Dialects and Formatting Parameters. (line 52) * quoted-printable; encoding: quopri — Encode and decode MIME quoted-printable data. (line 8) * quotes (shlex.shlex attribute): shlex Objects. (line 115) * QUOTE_ALL (in module csv): Module Contents<3>. (line 234) * quote_from_bytes() (in module urllib.parse): URL Quoting. (line 52) * QUOTE_MINIMAL (in module csv): Module Contents<3>. (line 238) * QUOTE_NONE (in module csv): Module Contents<3>. (line 252) * QUOTE_NONNUMERIC (in module csv): Module Contents<3>. (line 244) * quote_plus() (in module urllib.parse): URL Quoting. (line 41) * quoting (csv.Dialect attribute): Dialects and Formatting Parameters. (line 58) * r"; raw string literal: String and Bytes literals. (line 48) * r’; raw string literal: String and Bytes literals. (line 48) * radians() (in module math): Angular conversion. (line 10) * radians() (in module turtle): Settings for measurement. (line 28) * RadioButtonGroup (class in msilib): GUI classes. (line 29) * radiogroup() (msilib.Dialog method): GUI classes. (line 73) * radix() (decimal.Context method): Context objects. (line 464) * radix() (decimal.Decimal method): Decimal objects. (line 490) * RADIXCHAR (in module locale): locale — Internationalization services. (line 232) * raise (2to3 fixer): Fixers. (line 261) * raise an exception: Exceptions<2>. (line 6) * raise_on_defect (email.policy.Policy attribute): email policy Policy Objects. (line 180) * raise_signal() (in module signal): Module contents<2>. (line 276) * RAISE_VARARGS (opcode): Python Bytecode Instructions. (line 757) * raising; exception: The raise statement. (line 6) * randbelow() (in module secrets): Random numbers. (line 19) * randbits() (in module secrets): Random numbers. (line 23) * randint() (in module random): Functions for integers. (line 23) * Random (class in random): Alternative Generator. (line 6) * random (module): random — Generate pseudo-random numbers. (line 6) * random() (in module random): Real-valued distributions. (line 11) * randrange() (in module random): Functions for integers. (line 6) * RAND_add() (in module ssl): Random generation. (line 66) * RAND_bytes() (in module ssl): Random generation. (line 6) * RAND_egd() (in module ssl): Random generation. (line 50) * RAND_pseudo_bytes() (in module ssl): Random generation. (line 23) * RAND_status() (in module ssl): Random generation. (line 43) * range (built-in class): Ranges. (line 10) * RARROW (in module token): token — Constants used with Python parse trees. (line 230) * ratecv() (in module audioop): audioop — Manipulate raw audio data. (line 175) * ratio() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 178) * Rational (class in numbers): The numeric tower. (line 41) * raw (io.BufferedIOBase attribute): I/O Base Classes. (line 249) * raw string: String and Bytes literals. (line 36) * raw() (in module curses): Functions<3>. (line 389) * raw() (pickle.PickleBuffer method): Module Interface. (line 317) * RawArray() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 16) * RawConfigParser (class in configparser): RawConfigParser Objects. (line 6) * RawDescriptionHelpFormatter (class in argparse): formatter_class. (line 10) * RawIOBase (class in io): I/O Base Classes. (line 170) * RawPen (class in turtle): Public classes. (line 6) * RawTextHelpFormatter (class in argparse): formatter_class. (line 10) * RawTurtle (class in turtle): Public classes. (line 6) * RawValue() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 33) * raw_data_manager (in module email.contentmanager): Content Manager Instances. (line 11) * raw_decode() (json.JSONDecoder method): Encoders and Decoders. (line 93) * raw_input (2to3 fixer): Fixers. (line 268) * raw_input() (code.InteractiveConsole method): Interactive Console Objects. (line 44) * RBRACE (in module token): token — Constants used with Python parse trees. (line 130) * rcpttos (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 79) * re (module): re — Regular expression operations. (line 6) * re (re.Match attribute): Match Objects. (line 191) * read() (asyncio.StreamReader method): StreamReader. (line 15) * read() (chunk.Chunk method): chunk — Read IFF chunked data. (line 105) * read() (codecs.StreamReader method): StreamReader Objects. (line 34) * read() (configparser.ConfigParser method): ConfigParser Objects. (line 113) * read() (http.client.HTTPResponse method): HTTPResponse Objects. (line 13) * read() (imaplib.IMAP4 method): IMAP4 Objects. (line 192) * read() (in module os): File Descriptor Operations. (line 555) * read() (io.BufferedIOBase method): I/O Base Classes. (line 270) * read() (io.BufferedReader method): Buffered Streams. (line 80) * read() (io.RawIOBase method): I/O Base Classes. (line 183) * read() (io.TextIOBase method): Text I/O<2>. (line 52) * read() (mimetypes.MimeTypes method): MimeTypes Objects. (line 70) * read() (mmap.mmap method): mmap — Memory-mapped file support. (line 225) * read() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 32) * read() (ssl.MemoryBIO method): Memory BIO Support<2>. (line 148) * read() (ssl.SSLSocket method): SSL Sockets. (line 71) * read() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 25) * read() (zipfile.ZipFile method): ZipFile Objects. (line 215) * read1() (io.BufferedIOBase method): I/O Base Classes. (line 287) * read1() (io.BufferedReader method): Buffered Streams. (line 86) * read1() (io.BytesIO method): Buffered Streams. (line 43) * READABLE (in module tkinter): File Handlers. (line 41) * readable() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 164) * readable() (io.IOBase method): I/O Base Classes. (line 79) * readall() (io.RawIOBase method): I/O Base Classes. (line 198) * reader() (in module csv): Module Contents<3>. (line 8) * ReadError: tarfile — Read and write tar archive files. (line 186) * readexactly() (asyncio.StreamReader method): StreamReader. (line 34) * readfp() (configparser.ConfigParser method): ConfigParser Objects. (line 300) * readfp() (mimetypes.MimeTypes method): MimeTypes Objects. (line 78) * readframes() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 97) * readframes() (sunau.AU_read method): AU_read Objects. (line 47) * readframes() (wave.Wave_read method): Wave_read Objects. (line 46) * readinto() (http.client.HTTPResponse method): HTTPResponse Objects. (line 17) * readinto() (io.BufferedIOBase method): I/O Base Classes. (line 298) * readinto() (io.RawIOBase method): I/O Base Classes. (line 203) * readinto1() (io.BufferedIOBase method): I/O Base Classes. (line 311) * readinto1() (io.BytesIO method): Buffered Streams. (line 49) * readline (module): readline — GNU readline interface. (line 6) * readline() (asyncio.StreamReader method): StreamReader. (line 23) * readline() (codecs.StreamReader method): StreamReader Objects. (line 60) * readline() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 111) * readline() (imaplib.IMAP4 method): IMAP4 Objects. (line 197) * readline() (io.IOBase method): I/O Base Classes. (line 84) * readline() (io.TextIOBase method): Text I/O<2>. (line 58) * readline() (mmap.mmap method): mmap — Memory-mapped file support. (line 240) * readlines() (codecs.StreamReader method): StreamReader Objects. (line 71) * readlines() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 124) * readlines() (io.IOBase method): I/O Base Classes. (line 93) * readlink() (in module os): Files and Directories. (line 581) * readmodule() (in module pyclbr): pyclbr — Python module browser support. (line 19) * readmodule_ex() (in module pyclbr): pyclbr — Python module browser support. (line 31) * READONLY: Generic Attribute Management. (line 92) * readonly (memoryview attribute): Memory Views. (line 412) * readPlist() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 126) * readPlistFromBytes() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 149) * ReadTransport (class in asyncio): Transports Hierarchy. (line 20) * readuntil() (asyncio.StreamReader method): StreamReader. (line 43) * readv() (in module os): File Descriptor Operations. (line 636) * ready() (multiprocessing.pool.AsyncResult method): Process Pools. (line 209) * read_all() (telnetlib.Telnet method): Telnet Objects. (line 17) * read_binary() (in module importlib.resources): importlib resources – Resources. (line 80) * read_byte() (mmap.mmap method): mmap — Memory-mapped file support. (line 235) * read_bytes() (pathlib.Path method): Methods<2>. (line 262) * read_bytes() (zipfile.Path method): Path Objects. (line 58) * read_dict() (configparser.ConfigParser method): ConfigParser Objects. (line 172) * read_eager() (telnetlib.Telnet method): Telnet Objects. (line 35) * read_environ() (in module wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 306) * read_events() (xml.etree.ElementTree.XMLPullParser method): XMLPullParser Objects. (line 29) * read_file() (configparser.ConfigParser method): ConfigParser Objects. (line 150) * read_history_file() (in module readline): History file. (line 8) * read_init_file() (in module readline): Init file. (line 13) * read_lazy() (telnetlib.Telnet method): Telnet Objects. (line 43) * read_mime_types() (in module mimetypes): mimetypes — Map filenames to MIME types. (line 99) * READ_RESTRICTED: Generic Attribute Management. (line 92) * read_sb_data() (telnetlib.Telnet method): Telnet Objects. (line 59) * read_some() (telnetlib.Telnet method): Telnet Objects. (line 21) * read_string() (configparser.ConfigParser method): ConfigParser Objects. (line 162) * read_text() (in module importlib.resources): importlib resources – Resources. (line 91) * read_text() (pathlib.Path method): Methods<2>. (line 275) * read_text() (zipfile.Path method): Path Objects. (line 52) * read_token() (shlex.shlex method): shlex Objects. (line 20) * read_until() (telnetlib.Telnet method): Telnet Objects. (line 8) * read_very_eager() (telnetlib.Telnet method): Telnet Objects. (line 27) * read_very_lazy() (telnetlib.Telnet method): Telnet Objects. (line 51) * read_windows_registry() (mimetypes.MimeTypes method): MimeTypes Objects. (line 86) * Real (class in numbers): The numeric tower. (line 28) * real (numbers.Complex attribute): The numeric tower. (line 15) * Real Media File Format: chunk — Read IFF chunked data. (line 8) * realloc(): Overview<3>. (line 33) * realpath() (in module os.path): os path — Common pathname manipulations. (line 295) * REALTIME_PRIORITY_CLASS (in module subprocess): Windows Constants. (line 87) * real_max_memuse (in module test.support): test support — Utilities for the Python test suite. (line 127) * real_quick_ratio() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 207) * reap_children() (in module test.support): test support — Utilities for the Python test suite. (line 792) * reap_threads() (in module test.support): test support — Utilities for the Python test suite. (line 655) * reason (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 55) * reason (ssl.SSLError attribute): Exceptions<12>. (line 27) * reason (UnicodeError attribute): Concrete exceptions. (line 346) * reason (urllib.error.HTTPError attribute): urllib error — Exception classes raised by urllib request. (line 45) * reason (urllib.error.URLError attribute): urllib error — Exception classes raised by urllib request. (line 22) * reattach() (tkinter.ttk.Treeview method): ttk Treeview. (line 247) * rebinding; name: Assignment statements. (line 6) * reccontrols() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 54) * received_data (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 84) * received_lines (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 57) * recent() (imaplib.IMAP4 method): IMAP4 Objects. (line 202) * reconfigure() (io.TextIOWrapper method): Text I/O<2>. (line 173) * records (unittest.TestCase attribute): Test cases. (line 428) * record_original_stdout() (in module test.support): test support — Utilities for the Python test suite. (line 376) * rect() (in module cmath): Conversions to and from polar coordinates. (line 48) * rectangle() (in module curses.textpad): curses textpad — Text input widget for curses programs. (line 15) * RecursionError: Concrete exceptions. (line 187) * recursive_repr() (in module reprlib): reprlib — Alternate repr implementation. (line 41) * recv() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 204) * recv() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 24) * recv() (socket.socket method): Socket Objects. (line 219) * recvfrom() (socket.socket method): Socket Objects. (line 236) * recvfrom_into() (socket.socket method): Socket Objects. (line 362) * recvmsg() (socket.socket method): Socket Objects. (line 254) * recvmsg_into() (socket.socket method): Socket Objects. (line 325) * recv_bytes() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 65) * recv_bytes_into() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 79) * recv_into() (socket.socket method): Socket Objects. (line 372) * redirect_request() (urllib.request.HTTPRedirectHandler method): HTTPRedirectHandler Objects. (line 15) * redirect_stderr() (in module contextlib): Utilities. (line 255) * redirect_stdout() (in module contextlib): Utilities. (line 216) * redisplay() (in module readline): Line buffer. (line 19) * redrawln() (curses.window method): Window Objects. (line 459) * redrawwin() (curses.window method): Window Objects. (line 465) * reduce (2to3 fixer): Fixers. (line 272) * reduce() (in module functools): functools — Higher-order functions and operations on callable objects. (line 291) * reducer_override() (pickle.Pickler method): Module Interface. (line 200) * ref (class in weakref): weakref — Weak references. (line 85) * refcount_test() (in module test.support): test support — Utilities for the Python test suite. (line 648) * reference count: Glossary. (line 1127) * reference counting: Objects values and types. (line 37) * ReferenceError: Concrete exceptions. (line 196) * ReferenceType (in module weakref): weakref — Weak references. (line 290) * refold_source (email.policy.EmailPolicy attribute): email policy Policy Objects. (line 371) * refresh() (curses.window method): Window Objects. (line 470) * register() (abc.ABCMeta method): abc — Abstract Base Classes. (line 69) * register() (in module atexit): atexit — Exit handlers. (line 22) * register() (in module codecs): codecs — Codec registry and base classes. (line 150) * register() (in module faulthandler): Dumping the traceback on a user signal. (line 6) * register() (in module webbrowser): webbrowser — Convenient Web-browser controller. (line 83) * register() (multiprocessing.managers.BaseManager method): Managers. (line 75) * register() (select.devpoll method): /dev/poll Polling Objects. (line 30) * register() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 81) * register() (select.poll method): Polling Objects. (line 15) * register() (selectors.BaseSelector method): Classes<3>. (line 65) * registerDOMImplementation() (in module xml.dom): Module Contents<4>. (line 8) * registerResult() (in module unittest): Signal Handling. (line 35) * register_adapter() (in module sqlite3): Module functions and constants. (line 140) * register_archive_format() (in module shutil): Archiving operations. (line 81) * register_at_fork() (in module os): Process Management. (line 464) * register_converter() (in module sqlite3): Module functions and constants. (line 131) * register_defect() (email.policy.Policy method): email policy Policy Objects. (line 229) * register_dialect() (in module csv): Module Contents<3>. (line 70) * register_error() (in module codecs): Error Handlers. (line 88) * register_function() (xmlrpc.server.CGIXMLRPCRequestHandler method): CGIXMLRPCRequestHandler. (line 9) * register_function() (xmlrpc.server.SimpleXMLRPCServer method): SimpleXMLRPCServer Objects. (line 10) * register_instance() (xmlrpc.server.CGIXMLRPCRequestHandler method): CGIXMLRPCRequestHandler. (line 26) * register_instance() (xmlrpc.server.SimpleXMLRPCServer method): SimpleXMLRPCServer Objects. (line 27) * register_introspection_functions() (xmlrpc.server.CGIXMLRPCRequestHandler method): CGIXMLRPCRequestHandler. (line 41) * register_introspection_functions() (xmlrpc.server.SimpleXMLRPCServer method): SimpleXMLRPCServer Objects. (line 55) * register_multicall_functions() (xmlrpc.server.CGIXMLRPCRequestHandler method): CGIXMLRPCRequestHandler. (line 46) * register_multicall_functions() (xmlrpc.server.SimpleXMLRPCServer method): SimpleXMLRPCServer Objects. (line 60) * register_namespace() (in module xml.etree.ElementTree): Functions<6>. (line 182) * register_optionflag() (in module doctest): Option Flags. (line 172) * register_shape() (in module turtle): Settings and special methods. (line 71) * register_unpack_format() (in module shutil): Archiving operations. (line 126) * regular package: Glossary. (line 1135) * REG_BINARY (in module winreg): Value Types. (line 8) * REG_DWORD (in module winreg): Value Types. (line 12) * REG_DWORD_BIG_ENDIAN (in module winreg): Value Types. (line 21) * REG_DWORD_LITTLE_ENDIAN (in module winreg): Value Types. (line 16) * REG_EXPAND_SZ (in module winreg): Value Types. (line 25) * REG_FULL_RESOURCE_DESCRIPTOR (in module winreg): Value Types. (line 60) * REG_LINK (in module winreg): Value Types. (line 30) * REG_MULTI_SZ (in module winreg): Value Types. (line 34) * REG_NONE (in module winreg): Value Types. (line 39) * REG_QWORD (in module winreg): Value Types. (line 43) * REG_QWORD_LITTLE_ENDIAN (in module winreg): Value Types. (line 49) * REG_RESOURCE_LIST (in module winreg): Value Types. (line 56) * REG_RESOURCE_REQUIREMENTS_LIST (in module winreg): Value Types. (line 64) * REG_SZ (in module winreg): Value Types. (line 68) * relative; import: The import statement. (line 98) * relative; URL: urllib parse — Parse URLs into components. (line 8) * relative_to() (pathlib.PurePath method): Methods and properties. (line 242) * release() (asyncio.Condition method): Condition. (line 79) * release() (asyncio.Lock method): Lock. (line 50) * release() (asyncio.Semaphore method): Semaphore. (line 55) * release() (in module platform): Cross Platform. (line 115) * release() (logging.Handler method): Handler Objects. (line 31) * release() (memoryview method): Memory Views. (line 235) * release() (multiprocessing.Lock method): Synchronization primitives. (line 92) * release() (multiprocessing.RLock method): Synchronization primitives. (line 148) * release() (pickle.PickleBuffer method): Module Interface. (line 325) * release() (threading.Condition method): Condition Objects. (line 91) * release() (threading.Lock method): Lock Objects. (line 73) * release() (threading.RLock method): RLock Objects. (line 66) * release() (threading.Semaphore method): Semaphore Objects. (line 63) * release() (_thread.lock method): _thread — Low-level threading API. (line 151) * releasebufferproc (C type): Slot Type typedefs. (line 107) * release_lock() (in module imp): imp — Access the import internals. (line 295) * reload (2to3 fixer): Fixers. (line 276) * reload() (in module imp): imp — Access the import internals. (line 132) * reload() (in module importlib): Functions<10>. (line 73) * relpath() (in module os.path): os path — Common pathname manipulations. (line 310) * remainder() (decimal.Context method): Context objects. (line 468) * remainder() (in module math): Number-theoretic and representation functions. (line 205) * remainder_near() (decimal.Context method): Context objects. (line 475) * remainder_near() (decimal.Decimal method): Decimal objects. (line 496) * RemoteDisconnected: http client — HTTP protocol client. (line 184) * remove() (array.array method): array — Efficient arrays of numeric values. (line 210) * remove() (collections.deque method): deque objects. (line 97) * remove() (frozenset method): Set Types — set frozenset. (line 199) * remove() (in module os): Files and Directories. (line 619) * remove() (mailbox.Mailbox method): Mailbox objects. (line 76) * remove() (mailbox.MH method): MH. (line 76) * remove() (sequence method): Mutable Sequence Types. (line 16) * remove() (xml.etree.ElementTree.Element method): Element Objects. (line 180) * removeAttribute() (xml.dom.Element method): Element Objects<2>. (line 52) * removeAttributeNode() (xml.dom.Element method): Element Objects<2>. (line 57) * removeAttributeNS() (xml.dom.Element method): Element Objects<2>. (line 62) * removeChild() (xml.dom.Node method): Node Objects. (line 128) * removedirs() (in module os): Files and Directories. (line 642) * removeFilter() (logging.Handler method): Handler Objects. (line 56) * removeFilter() (logging.Logger method): Logger Objects. (line 255) * removeHandler() (in module unittest): Signal Handling. (line 52) * removeHandler() (logging.Logger method): Logger Objects. (line 272) * removeResult() (in module unittest): Signal Handling. (line 46) * removexattr() (in module os): Linux extended attributes. (line 41) * remove_child_handler() (asyncio.AbstractChildWatcher method): Process Watchers. (line 52) * remove_done_callback() (asyncio.Future method): Future Object. (line 102) * remove_done_callback() (asyncio.Task method): Task Object. (line 158) * remove_flag() (mailbox.MaildirMessage method): MaildirMessage. (line 84) * remove_flag() (mailbox.mboxMessage method): mboxMessage. (line 85) * remove_flag() (mailbox.MMDFMessage method): MMDFMessage. (line 84) * remove_folder() (mailbox.Maildir method): Maildir. (line 76) * remove_folder() (mailbox.MH method): MH. (line 47) * remove_header() (urllib.request.Request method): Request Objects. (line 99) * remove_history_item() (in module readline): History list. (line 26) * remove_label() (mailbox.BabylMessage method): BabylMessage. (line 59) * remove_option() (configparser.ConfigParser method): ConfigParser Objects. (line 266) * remove_option() (optparse.OptionParser method): Querying and manipulating your option parser. (line 47) * remove_pyc() (msilib.Directory method): Directory Objects. (line 45) * remove_reader() (asyncio.loop method): Watching file descriptors. (line 12) * remove_section() (configparser.ConfigParser method): ConfigParser Objects. (line 273) * remove_sequence() (mailbox.MHMessage method): MHMessage. (line 46) * remove_signal_handler() (asyncio.loop method): Unix signals. (line 26) * remove_tree() (in module distutils.dir_util): distutils dir_util — Directory tree operations. (line 60) * remove_writer() (asyncio.loop method): Watching file descriptors. (line 25) * rename() (ftplib.FTP method): FTP Objects. (line 202) * rename() (imaplib.IMAP4 method): IMAP4 Objects. (line 207) * rename() (in module os): Files and Directories. (line 659) * rename() (pathlib.Path method): Methods<2>. (line 290) * renames (2to3 fixer): Fixers. (line 280) * renames() (in module os): Files and Directories. (line 693) * reopenIfNeeded() (logging.handlers.WatchedFileHandler method): WatchedFileHandler. (line 37) * reorganize() (dbm.gnu.gdbm method): dbm gnu — GNU’s reinterpretation of dbm. (line 104) * repeat() (in module itertools): Itertool functions. (line 493) * repeat() (in module timeit): Python Interface. (line 18) * repeat() (timeit.Timer method): Python Interface. (line 108) * repetition; operation: Common Sequence Operations. (line 21) * replace() (bytearray method): Bytes and Bytearray Operations. (line 145) * replace() (bytes method): Bytes and Bytearray Operations. (line 145) * replace() (curses.panel.Panel method): Panel Objects. (line 39) * replace() (datetime.date method): date Objects. (line 166) * replace() (datetime.datetime method): datetime Objects. (line 413) * replace() (datetime.time method): time Objects. (line 139) * replace() (in module dataclasses): Module-level decorators classes and functions. (line 345) * replace() (in module os): Files and Directories. (line 711) * replace() (inspect.Parameter method): Introspecting callables with the Signature object. (line 253) * replace() (inspect.Signature method): Introspecting callables with the Signature object. (line 111) * replace() (pathlib.Path method): Methods<2>. (line 314) * replace() (str method): String Methods<2>. (line 339) * replace() (types.CodeType method): Standard Interpreter Types. (line 63) * replaceChild() (xml.dom.Node method): Node Objects. (line 135) * ReplacePackage() (in module modulefinder): modulefinder — Find modules used by a script. (line 21) * replace_errors() (in module codecs): Error Handlers. (line 133) * replace_header() (email.message.EmailMessage method): email message Representing an email message. (line 301) * replace_header() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 409) * replace_history_item() (in module readline): History list. (line 32) * replace_whitespace (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 171) * report() (filecmp.dircmp method): The dircmp class. (line 18) * report() (modulefinder.ModuleFinder method): modulefinder — Find modules used by a script. (line 38) * REPORTING_FLAGS (in module doctest): Option Flags. (line 164) * REPORT_CDIFF (in module doctest): Option Flags. (line 126) * report_failure() (doctest.DocTestRunner method): DocTestRunner objects. (line 70) * report_full_closure() (filecmp.dircmp method): The dircmp class. (line 28) * REPORT_NDIFF (in module doctest): Option Flags. (line 131) * REPORT_ONLY_FIRST_FAILURE (in module doctest): Option Flags. (line 140) * report_partial_closure() (filecmp.dircmp method): The dircmp class. (line 23) * report_start() (doctest.DocTestRunner method): DocTestRunner objects. (line 48) * report_success() (doctest.DocTestRunner method): DocTestRunner objects. (line 59) * REPORT_UDIFF (in module doctest): Option Flags. (line 121) * report_unexpected_exception() (doctest.DocTestRunner method): DocTestRunner objects. (line 81) * repr (2to3 fixer): Fixers. (line 284) * Repr (class in reprlib): reprlib — Alternate repr implementation. (line 17) * repr() (built-in function): Built-in Functions. (line 1418) * repr() (built-in function); __repr__() (object method): Basic customization. (line 113) * repr() (in module reprlib): reprlib — Alternate repr implementation. (line 31) * repr() (reprlib.Repr method): Repr Objects. (line 47) * repr1() (reprlib.Repr method): Repr Objects. (line 52) * reprfunc (C type): Slot Type typedefs. (line 49) * reprlib (module): reprlib — Alternate repr implementation. (line 6) * Request (class in urllib.request): urllib request — Extensible library for opening URLs. (line 182) * request() (http.client.HTTPConnection method): HTTPConnection Objects. (line 8) * RequestHandlerClass (socketserver.BaseServer attribute): Server Objects<2>. (line 71) * requestline (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 81) * request_queue_size (socketserver.BaseServer attribute): Server Objects<2>. (line 98) * request_rate() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 60) * request_uri() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 25) * request_version (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 96) * requires() (in module test.support): test support — Utilities for the Python test suite. (line 211) * requires_bz2() (in module test.support): test support — Utilities for the Python test suite. (line 617) * requires_docstrings() (in module test.support): test support — Utilities for the Python test suite. (line 629) * requires_freebsd_version() (in module test.support): test support — Utilities for the Python test suite. (line 587) * requires_gzip() (in module test.support): test support — Utilities for the Python test suite. (line 613) * requires_IEEE_754() (in module test.support): test support — Utilities for the Python test suite. (line 605) * requires_linux_version() (in module test.support): test support — Utilities for the Python test suite. (line 593) * requires_lzma() (in module test.support): test support — Utilities for the Python test suite. (line 621) * requires_mac_version() (in module test.support): test support — Utilities for the Python test suite. (line 599) * requires_resource() (in module test.support): test support — Utilities for the Python test suite. (line 625) * requires_zlib() (in module test.support): test support — Utilities for the Python test suite. (line 609) * reserved (zipfile.ZipInfo attribute): ZipInfo Objects. (line 111) * reserved word: Keywords. (line 6) * RESERVED_FUTURE (in module uuid): uuid — UUID objects according to RFC 4122. (line 236) * RESERVED_MICROSOFT (in module uuid): uuid — UUID objects according to RFC 4122. (line 232) * RESERVED_NCS (in module uuid): uuid — UUID objects according to RFC 4122. (line 224) * reset() (bdb.Bdb method): bdb — Debugger framework. (line 106) * reset() (codecs.IncrementalDecoder method): IncrementalDecoder Objects. (line 40) * reset() (codecs.IncrementalEncoder method): IncrementalEncoder Objects. (line 35) * reset() (codecs.StreamReader method): StreamReader Objects. (line 83) * reset() (codecs.StreamWriter method): StreamWriter Objects. (line 41) * reset() (contextvars.ContextVar method): Context Variables. (line 58) * reset() (html.parser.HTMLParser method): HTMLParser Methods. (line 23) * reset() (in module turtle): Window control. (line 51) * reset() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 172) * reset() (pipes.Template method): Template Objects. (line 8) * reset() (threading.Barrier method): Barrier Objects. (line 71) * reset() (xdrlib.Packer method): Packer Objects. (line 12) * reset() (xdrlib.Unpacker method): Unpacker Objects. (line 8) * reset() (xml.dom.pulldom.DOMEventStream method): DOMEventStream Objects. (line 37) * reset() (xml.sax.xmlreader.IncrementalParser method): IncrementalParser Objects. (line 19) * resetbuffer() (code.InteractiveConsole method): Interactive Console Objects. (line 40) * resetlocale() (in module locale): locale — Internationalization services. (line 367) * resetscreen() (in module turtle): Window control. (line 51) * resetty() (in module curses): Functions<3>. (line 405) * resetwarnings() (in module warnings): Available Functions. (line 99) * reset_mock() (unittest.mock.AsyncMock method): The Mock Class. (line 860) * reset_mock() (unittest.mock.Mock method): The Mock Class. (line 198) * reset_prog_mode() (in module curses): Functions<3>. (line 395) * reset_shell_mode() (in module curses): Functions<3>. (line 400) * resize() (curses.window method): Window Objects. (line 489) * resize() (in module ctypes): Utility functions. (line 163) * resize() (mmap.mmap method): mmap — Memory-mapped file support. (line 245) * resizemode() (in module turtle): Appearance. (line 24) * resizeterm() (in module curses): Functions<3>. (line 420) * resize_term() (in module curses): Functions<3>. (line 410) * resolution (datetime.date attribute): date Objects. (line 95) * resolution (datetime.datetime attribute): datetime Objects. (line 257) * resolution (datetime.time attribute): time Objects. (line 42) * resolution (datetime.timedelta attribute): timedelta Objects. (line 84) * resolve() (pathlib.Path method): Methods<2>. (line 327) * resolveEntity() (xml.sax.handler.EntityResolver method): EntityResolver Objects. (line 6) * resolve_bases() (in module types): Dynamic Type Creation. (line 58) * resolve_name() (in module importlib.util): importlib util – Utility code for importers. (line 80) * Resource (in module importlib.resources): importlib resources – Resources. (line 45) * resource (module): resource — Resource usage information. (line 6) * ResourceDenied: test support — Utilities for the Python test suite. (line 22) * ResourceLoader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 358) * ResourceReader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 287) * ResourceWarning: Warnings. (line 59) * resource_path() (importlib.abc.ResourceReader method): importlib abc – Abstract base classes related to import. (line 327) * response (nntplib.NNTPError attribute): nntplib — NNTP protocol client. (line 128) * response() (imaplib.IMAP4 method): IMAP4 Objects. (line 211) * ResponseNotReady: http client — HTTP protocol client. (line 170) * responses (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 169) * responses (in module http.client): http client — HTTP protocol client. (line 205) * restart (pdb command): Debugger Commands. (line 322) * restore() (in module difflib): difflib — Helpers for computing deltas. (line 273) * RESTRICTED: Generic Attribute Management. (line 92) * restricted; execution: Builtins and restricted execution. (line 6) * restype (ctypes._FuncPtr attribute): Foreign functions. (line 22) * result() (asyncio.Future method): Future Object. (line 28) * result() (asyncio.Task method): Task Object. (line 120) * result() (concurrent.futures.Future method): Future Objects. (line 38) * results() (trace.Trace method): Programmatic Interface. (line 40) * resume_reading() (asyncio.ReadTransport method): Read-only Transports. (line 21) * resume_writing() (asyncio.BaseProtocol method): Base Protocol. (line 44) * retr() (poplib.POP3 method): POP3 Objects. (line 62) * retrbinary() (ftplib.FTP method): FTP Objects. (line 84) * retrieve() (urllib.request.URLopener method): Legacy interface. (line 113) * retrlines() (ftplib.FTP method): FTP Objects. (line 96) * return (pdb command): Debugger Commands. (line 188) * returncode (asyncio.asyncio.subprocess.Process attribute): Interacting with Subprocesses. (line 140) * returncode (subprocess.CalledProcessError attribute): Using the subprocess Module. (line 196) * returncode (subprocess.CompletedProcess attribute): Using the subprocess Module. (line 101) * returncode (subprocess.Popen attribute): Popen Objects. (line 145) * return_annotation (inspect.Signature attribute): Introspecting callables with the Signature object. (line 90) * return_ok() (http.cookiejar.CookiePolicy method): CookiePolicy Objects. (line 18) * RETURN_VALUE (opcode): Python Bytecode Instructions. (line 342) * return_value (unittest.mock.Mock attribute): The Mock Class. (line 321) * retval (pdb command): Debugger Commands. (line 341) * reverse() (array.array method): array — Efficient arrays of numeric values. (line 214) * reverse() (collections.deque method): deque objects. (line 102) * reverse() (in module audioop): audioop — Manipulate raw audio data. (line 188) * reverse() (sequence method): Mutable Sequence Types. (line 16) * reversed() (built-in function): Built-in Functions. (line 1430) * reverse_order() (pstats.Stats method): The Stats Class. (line 157) * reverse_pointer (ipaddress.IPv4Address attribute): Address objects. (line 71) * reverse_pointer (ipaddress.IPv6Address attribute): Address objects. (line 165) * Reversible (class in collections.abc): Collections Abstract Base Classes. (line 143) * Reversible (class in typing): Classes functions and decorators. (line 155) * revert() (http.cookiejar.FileCookieJar method): CookieJar and FileCookieJar Objects. (line 141) * rewind() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 103) * rewind() (sunau.AU_read method): AU_read Objects. (line 53) * rewind() (wave.Wave_read method): Wave_read Objects. (line 51) * rfc2109 (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 68) * rfc2109_as_netscape (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 83) * rfc2965 (http.cookiejar.CookiePolicy attribute): CookiePolicy Objects. (line 72) * rfc822_escape() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 172) * RFC; RFC 1014: xdrlib — Encode and decode XDR data. (line 11) * RFC; RFC 1014 <1>: xdrlib — Encode and decode XDR data. (line 32) * RFC; RFC 1123: Functions<2>. (line 615) * RFC; RFC 1321: hashlib — Secure hashes and message digests. (line 13) * RFC; RFC 1422: Certificates. (line 38) * RFC; RFC 1422 <1>: LibreSSL support. (line 29) * RFC; RFC 1521: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 270) * RFC; RFC 1521 <1>: quopri — Encode and decode MIME quoted-printable data. (line 11) * RFC; RFC 1521 <2>: quopri — Encode and decode MIME quoted-printable data. (line 37) * RFC; RFC 1522: binascii — Convert between binary and ASCII. (line 71) * RFC; RFC 1522 <1>: quopri — Encode and decode MIME quoted-printable data. (line 25) * RFC; RFC 1522 <2>: quopri — Encode and decode MIME quoted-printable data. (line 39) * RFC; RFC 1524: mailcap — Mailcap file handling. (line 19) * RFC; RFC 1524 <1>: mailcap — Mailcap file handling. (line 38) * RFC; RFC 1730: imaplib — IMAP4 protocol client. (line 14) * RFC; RFC 1738: URL Quoting. (line 176) * RFC; RFC 1750: Random generation. (line 70) * RFC; RFC 1766: locale — Internationalization services. (line 322) * RFC; RFC 1766 <1>: locale — Internationalization services. (line 333) * RFC; RFC 1808: urllib. (line 23) * RFC; RFC 1808 <1>: URL Parsing. (line 33) * RFC; RFC 1808 <2>: URL Quoting. (line 170) * RFC; RFC 1832: xdrlib — Encode and decode XDR data. (line 36) * RFC; RFC 1832 <1>: xdrlib — Encode and decode XDR data. (line 38) * RFC; RFC 1869: smtplib — SMTP protocol client. (line 13) * RFC; RFC 1869 <1>: smtplib — SMTP protocol client. (line 184) * RFC; RFC 1870: smtpd<3>. (line 7) * RFC; RFC 1870 <1>: smtpd — SMTP Server. (line 26) * RFC; RFC 1870 <2>: SMTPChannel Objects. (line 125) * RFC; RFC 1939: poplib — POP3 protocol client. (line 11) * RFC; RFC 1939 <1>: poplib — POP3 protocol client. (line 13) * RFC; RFC 2033: New and Improved Modules<2>. (line 569) * RFC; RFC 2045: email — An email and MIME handling package. (line 16) * RFC; RFC 2045 <1>: email message Representing an email message. (line 316) * RFC; RFC 2045 <2>: email message Representing an email message. (line 318) * RFC; RFC 2045 <3>: email message Representing an email message. (line 321) * RFC; RFC 2045 <4>: email headerregistry Custom Header Objects. (line 239) * RFC; RFC 2045 <5>: email headerregistry Custom Header Objects. (line 297) * RFC; RFC 2045 <6>: email message Message Representing an email message using the compat32 API. (line 422) * RFC; RFC 2045 <7>: email message Message Representing an email message using the compat32 API. (line 426) * RFC; RFC 2045 <8>: email message Message Representing an email message using the compat32 API. (line 429) * RFC; RFC 2045 <9>: email message Message Representing an email message using the compat32 API. (line 526) * RFC; RFC 2045 <10>: email header Internationalized headers. (line 31) * RFC; RFC 2045 <11>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 30) * RFC; RFC 2045 <12>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 31) * RFC; RFC 2045 <13>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 234) * RFC; RFC 2045 <14>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 242) * RFC; RFC 2045#section-6.8: Binary Objects. (line 31) * RFC; RFC 2046: email — An email and MIME handling package. (line 16) * RFC; RFC 2046 <1>: Content Manager Instances. (line 85) * RFC; RFC 2046 <2>: email header Internationalized headers. (line 32) * RFC; RFC 2047: PEP 3333 Python Web Server Gateway Interface v1 0 1. (line 21) * RFC; RFC 2047 <1>: email<5>. (line 27) * RFC; RFC 2047 <2>: email — An email and MIME handling package. (line 16) * RFC; RFC 2047 <3>: email policy Policy Objects. (line 347) * RFC; RFC 2047 <4>: email policy Policy Objects. (line 353) * RFC; RFC 2047 <5>: email headerregistry Custom Header Objects. (line 78) * RFC; RFC 2047 <6>: email headerregistry Custom Header Objects. (line 123) * RFC; RFC 2047 <7>: email headerregistry Custom Header Objects. (line 128) * RFC; RFC 2047 <8>: email header Internationalized headers. (line 32) * RFC; RFC 2047 <9>: email header Internationalized headers. (line 55) * RFC; RFC 2047 <10>: email header Internationalized headers. (line 117) * RFC; RFC 2047 <11>: email header Internationalized headers. (line 141) * RFC; RFC 2047 <12>: email utils Miscellaneous utilities. (line 74) * RFC; RFC 2060: imaplib — IMAP4 protocol client. (line 13) * RFC; RFC 2060 <1>: IMAP4 Objects. (line 310) * RFC; RFC 2068: http cookies — HTTP state management. (line 16) * RFC; RFC 2104: New and Improved Modules<3>. (line 35) * RFC; RFC 2104 <1>: hmac — Keyed-Hashing for Message Authentication. (line 10) * RFC; RFC 2109: http cookies — HTTP state management. (line 15) * RFC; RFC 2109 <1>: http cookies — HTTP state management. (line 35) * RFC; RFC 2109 <2>: http cookies — HTTP state management. (line 65) * RFC; RFC 2109 <3>: Morsel Objects. (line 8) * RFC; RFC 2109 <4>: Morsel Objects. (line 11) * RFC; RFC 2109 <5>: Morsel Objects. (line 98) * RFC; RFC 2109 <6>: Morsel Objects. (line 110) * RFC; RFC 2109 <7>: http cookiejar — Cookie handling for HTTP clients. (line 17) * RFC; RFC 2109 <8>: http cookiejar — Cookie handling for HTTP clients. (line 99) * RFC; RFC 2109 <9>: http cookiejar — Cookie handling for HTTP clients. (line 111) * RFC; RFC 2109 <10>: http cookiejar — Cookie handling for HTTP clients. (line 138) * RFC; RFC 2109 <11>: DefaultCookiePolicy Objects. (line 86) * RFC; RFC 2109 <12>: Cookie Objects<2>. (line 11) * RFC; RFC 2109 <13>: Cookie Objects<2>. (line 23) * RFC; RFC 2109 <14>: Cookie Objects<2>. (line 70) * RFC; RFC 2183: email — An email and MIME handling package. (line 16) * RFC; RFC 2183 <1>: email message Representing an email message. (line 460) * RFC; RFC 2183 <2>: email message Message Representing an email message using the compat32 API. (line 632) * RFC; RFC 2231: email — An email and MIME handling package. (line 16) * RFC; RFC 2231 <1>: email message Representing an email message. (line 280) * RFC; RFC 2231 <2>: email message Representing an email message. (line 283) * RFC; RFC 2231 <3>: email message Representing an email message. (line 365) * RFC; RFC 2231 <4>: email message Message Representing an email message using the compat32 API. (line 385) * RFC; RFC 2231 <5>: email message Message Representing an email message using the compat32 API. (line 389) * RFC; RFC 2231 <6>: email message Message Representing an email message using the compat32 API. (line 491) * RFC; RFC 2231 <7>: email message Message Representing an email message using the compat32 API. (line 499) * RFC; RFC 2231 <8>: email message Message Representing an email message using the compat32 API. (line 533) * RFC; RFC 2231 <9>: email header Internationalized headers. (line 32) * RFC; RFC 2231 <10>: email utils Miscellaneous utilities. (line 176) * RFC; RFC 2231 <11>: email utils Miscellaneous utilities. (line 181) * RFC; RFC 2231 <12>: email utils Miscellaneous utilities. (line 190) * RFC; RFC 2231 <13>: email utils Miscellaneous utilities. (line 197) * RFC; RFC 2231 <14>: email utils Miscellaneous utilities. (line 206) * RFC; RFC 2295: HTTP status codes. (line 175) * RFC; RFC 2342: New and Improved Modules<3>. (line 93) * RFC; RFC 2342 <1>: IMAP4 Objects. (line 164) * RFC; RFC 2368: URL Quoting. (line 166) * RFC; RFC 2373: Address objects. (line 89) * RFC; RFC 2373 <1>: Address objects. (line 108) * RFC; RFC 2373 <2>: Address objects. (line 117) * RFC; RFC 2396: urllib parse. (line 6) * RFC; RFC 2396 <1>: urllib. (line 24) * RFC; RFC 2396 <2>: URL Parsing. (line 245) * RFC; RFC 2396 <3>: URL Quoting. (line 24) * RFC; RFC 2396 <4>: URL Quoting. (line 161) * RFC; RFC 2397: DataHandler Objects. (line 9) * RFC; RFC 2449: POP3 Objects. (line 26) * RFC; RFC 2487: New and Improved Modules<3>. (line 85) * RFC; RFC 2518: HTTP status codes. (line 19) * RFC; RFC 2595: poplib — POP3 protocol client. (line 14) * RFC; RFC 2595 <1>: POP3 Objects. (line 115) * RFC; RFC 2616: PEP 3333 Python Web Server Gateway Interface v1 0 1. (line 20) * RFC; RFC 2616 <1>: wsgiref util – WSGI environment utilities. (line 112) * RFC; RFC 2616 <2>: wsgiref validate — WSGI conformance checker. (line 27) * RFC; RFC 2616 <3>: HTTPRedirectHandler Objects. (line 8) * RFC; RFC 2616 <4>: HTTPRedirectHandler Objects. (line 28) * RFC; RFC 2616 <5>: Legacy interface. (line 164) * RFC; RFC 2616 <6>: urllib error — Exception classes raised by urllib request. (line 40) * RFC; RFC 2616 <7>: Introduction<16>. (line 34) * RFC; RFC 2616 <8>: HTTPError. (line 15) * RFC; RFC 2616 <9>: Error Codes. (line 12) * RFC; RFC 2732: urllib parse<2>. (line 10) * RFC; RFC 2732 <1>: New and Improved Modules. (line 638) * RFC; RFC 2732 <2>: URL Quoting. (line 157) * RFC; RFC 2774: HTTP status codes. (line 184) * RFC; RFC 2818: ssl<9>. (line 16) * RFC; RFC 2818 <1>: Certificate handling. (line 11) * RFC; RFC 2821: email — An email and MIME handling package. (line 12) * RFC; RFC 2822: New and Improved Modules<3>. (line 97) * RFC; RFC 2822 <1>: Batteries Included. (line 16) * RFC; RFC 2822 <2>: Functions<2>. (line 346) * RFC; RFC 2822 <3>: Functions<2>. (line 616) * RFC; RFC 2822 <4>: email message Message Representing an email message using the compat32 API. (line 274) * RFC; RFC 2822 <5>: email header Internationalized headers. (line 20) * RFC; RFC 2822 <6>: email header Internationalized headers. (line 23) * RFC; RFC 2822 <7>: email header Internationalized headers. (line 31) * RFC; RFC 2822 <8>: email header Internationalized headers. (line 88) * RFC; RFC 2822 <9>: email header Internationalized headers. (line 116) * RFC; RFC 2822 <10>: email header Internationalized headers. (line 134) * RFC; RFC 2822 <11>: email utils Miscellaneous utilities. (line 31) * RFC; RFC 2822 <12>: email utils Miscellaneous utilities. (line 98) * RFC; RFC 2822 <13>: email utils Miscellaneous utilities. (line 101) * RFC; RFC 2822 <14>: email utils Miscellaneous utilities. (line 224) * RFC; RFC 2822 <15>: email utils Miscellaneous utilities. (line 142) * RFC; RFC 2822 <16>: Message objects. (line 17) * RFC; RFC 2822 <17>: http client — HTTP protocol client. (line 112) * RFC; RFC 2822 <18>: http server — HTTP servers. (line 108) * RFC; RFC 2964: http cookiejar — Cookie handling for HTTP clients. (line 151) * RFC; RFC 2965: urllib request — Extensible library for opening URLs. (line 225) * RFC; RFC 2965 <1>: urllib request — Extensible library for opening URLs. (line 233) * RFC; RFC 2965 <2>: Request Objects. (line 50) * RFC; RFC 2965 <3>: http cookiejar — Cookie handling for HTTP clients. (line 16) * RFC; RFC 2965 <4>: http cookiejar — Cookie handling for HTTP clients. (line 99) * RFC; RFC 2965 <5>: http cookiejar — Cookie handling for HTTP clients. (line 111) * RFC; RFC 2965 <6>: http cookiejar — Cookie handling for HTTP clients. (line 140) * RFC; RFC 2965 <7>: http cookiejar — Cookie handling for HTTP clients. (line 142) * RFC; RFC 2965 <8>: http cookiejar — Cookie handling for HTTP clients. (line 149) * RFC; RFC 2965 <9>: FileCookieJar subclasses and co-operation with web browsers. (line 16) * RFC; RFC 2965 <10>: CookiePolicy Objects. (line 74) * RFC; RFC 2965 <11>: CookiePolicy Objects. (line 79) * RFC; RFC 2965 <12>: DefaultCookiePolicy Objects. (line 8) * RFC; RFC 2965 <13>: DefaultCookiePolicy Objects. (line 90) * RFC; RFC 2965 <14>: DefaultCookiePolicy Objects. (line 101) * RFC; RFC 2965 <15>: DefaultCookiePolicy Objects. (line 105) * RFC; RFC 2965 <16>: DefaultCookiePolicy Objects. (line 114) * RFC; RFC 2965 <17>: DefaultCookiePolicy Objects. (line 151) * RFC; RFC 2965 <18>: Cookie Objects<2>. (line 23) * RFC; RFC 2965 <19>: Examples<24>. (line 25) * RFC; RFC 2980: nntplib — NNTP protocol client. (line 13) * RFC; RFC 2980 <1>: Methods<3>. (line 317) * RFC; RFC 3056: Address objects. (line 205) * RFC; RFC 3171: Address objects. (line 88) * RFC; RFC 3207: New and Improved Modules<2>. (line 574) * RFC; RFC 3229: HTTP status codes. (line 49) * RFC; RFC 3280: SSL Sockets. (line 152) * RFC; RFC 3330: Address objects. (line 116) * RFC; RFC 3339: Displaying the date/time in messages. (line 18) * RFC; RFC 3454: stringprep — Internet String Preparation. (line 17) * RFC; RFC 3454 <1>: stringprep — Internet String Preparation. (line 26) * RFC; RFC 3490: Text Encodings. (line 14) * RFC; RFC 3490 <1>: encodings idna — Internationalized Domain Names in Applications. (line 6) * RFC; RFC 3490 <2>: encodings idna — Internationalized Domain Names in Applications. (line 54) * RFC; RFC 3490 <3>: encodings idna — Internationalized Domain Names in Applications. (line 59) * RFC; RFC 3490#section-3.1: encodings idna — Internationalized Domain Names in Applications. (line 24) * RFC; RFC 3492: Text Encodings. (line 36) * RFC; RFC 3492 <1>: encodings idna — Internationalized Domain Names in Applications. (line 7) * RFC; RFC 3493: Example<8>. (line 227) * RFC; RFC 3501: IMAP4 Objects. (line 321) * RFC; RFC 3542: Other functions<2>. (line 302) * RFC; RFC 3548: New Improved and Deprecated Modules<3>. (line 16) * RFC; RFC 3548 <1>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 12) * RFC; RFC 3548 <2>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 16) * RFC; RFC 3548 <3>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 24) * RFC; RFC 3548 <4>: base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 112) * RFC; RFC 3548 <5>: binascii — Convert between binary and ASCII. (line 50) * RFC; RFC 3659: FTP Objects. (line 168) * RFC; RFC 3879: Address objects. (line 190) * RFC; RFC 3927: Address objects. (line 121) * RFC; RFC 3977: nntplib — NNTP protocol client. (line 13) * RFC; RFC 3977 <1>: Attributes. (line 10) * RFC; RFC 3977 <2>: Methods<3>. (line 36) * RFC; RFC 3977 <3>: Methods<3>. (line 138) * RFC; RFC 3977 <4>: Methods<3>. (line 318) * RFC; RFC 3986: urllib parse. (line 6) * RFC; RFC 3986 <1>: urllib. (line 22) * RFC; RFC 3986 <2>: New and Improved Modules. (line 617) * RFC; RFC 3986 <3>: Porting to Python 2 7. (line 80) * RFC; RFC 3986 <4>: URL Parsing. (line 130) * RFC; RFC 3986 <5>: URL Parsing. (line 342) * RFC; RFC 3986 <6>: URL Quoting. (line 24) * RFC; RFC 3986 <7>: URL Quoting. (line 149) * RFC; RFC 4086: LibreSSL support. (line 33) * RFC; RFC 4122: New Improved and Removed Modules. (line 417) * RFC; RFC 4122 <1>: New Improved and Removed Modules. (line 422) * RFC; RFC 4122 <2>: uuid — UUID objects according to RFC 4122. (line 6) * RFC; RFC 4122 <3>: uuid — UUID objects according to RFC 4122. (line 13) * RFC; RFC 4122 <4>: uuid — UUID objects according to RFC 4122. (line 71) * RFC; RFC 4122 <5>: uuid — UUID objects according to RFC 4122. (line 137) * RFC; RFC 4122 <6>: uuid — UUID objects according to RFC 4122. (line 166) * RFC; RFC 4122 <7>: uuid — UUID objects according to RFC 4122. (line 230) * RFC; RFC 4122 <8>: uuid — UUID objects according to RFC 4122. (line 243) * RFC; RFC 4180: csv — CSV File Reading and Writing. (line 13) * RFC; RFC 4193: Address objects. (line 192) * RFC; RFC 4217: ftplib — FTP protocol client. (line 77) * RFC; RFC 4291: Address objects. (line 135) * RFC; RFC 4380: Address objects. (line 212) * RFC; RFC 4627: json — JSON encoder and decoder. (line 11) * RFC; RFC 4627 <1>: Top-level Non-Object Non-Array Values. (line 6) * RFC; RFC 4642: nntplib — NNTP protocol client. (line 105) * RFC; RFC 4918: HTTP status codes. (line 43) * RFC; RFC 4918 <1>: HTTP status codes. (line 133) * RFC; RFC 4918 <2>: HTTP status codes. (line 136) * RFC; RFC 4918 <3>: HTTP status codes. (line 139) * RFC; RFC 4918 <4>: HTTP status codes. (line 178) * RFC; RFC 4954: SMTP Objects. (line 135) * RFC; RFC 4954 <1>: SMTP Objects. (line 158) * RFC; RFC 5161: imaplib. (line 11) * RFC; RFC 5161 <1>: IMAP4 Objects. (line 86) * RFC; RFC 5233: email — An email and MIME handling package. (line 15) * RFC; RFC 5233 <1>: email message Message Representing an email message using the compat32 API. (line 21) * RFC; RFC 5246: Constants<9>. (line 477) * RFC; RFC 5246 <1>: LibreSSL support. (line 41) * RFC; RFC 5280: Other Changes. (line 20) * RFC; RFC 5280 <1>: Changes in the Python API<4>. (line 95) * RFC; RFC 5280 <2>: Certificate handling. (line 11) * RFC; RFC 5280 <3>: Certificate handling. (line 64) * RFC; RFC 5280 <4>: LibreSSL support. (line 37) * RFC; RFC 5321: smtpd<3>. (line 6) * RFC; RFC 5321 <1>: email headerregistry Custom Header Objects. (line 453) * RFC; RFC 5321 <2>: smtpd — SMTP Server. (line 26) * RFC; RFC 5321 <3>: SMTPServer Objects. (line 50) * RFC; RFC 5321 <4>: SMTPServer Objects. (line 78) * RFC; RFC 5322: email message Representing an email message. (line 20) * RFC; RFC 5322 <1>: email message Representing an email message. (line 31) * RFC; RFC 5322 <2>: Parser API. (line 41) * RFC; RFC 5322 <3>: email generator Generating MIME documents. (line 102) * RFC; RFC 5322 <4>: email generator Generating MIME documents. (line 195) * RFC; RFC 5322 <5>: email policy Policy Objects. (line 148) * RFC; RFC 5322 <6>: email policy Policy Objects. (line 326) * RFC; RFC 5322 <7>: email policy Policy Objects. (line 347) * RFC; RFC 5322 <8>: email policy Policy Objects. (line 353) * RFC; RFC 5322 <9>: email policy Policy Objects. (line 365) * RFC; RFC 5322 <10>: email policy Policy Objects. (line 398) * RFC; RFC 5322 <11>: email errors Exception and Defect classes. (line 28) * RFC; RFC 5322 <12>: email headerregistry Custom Header Objects. (line 16) * RFC; RFC 5322 <13>: email headerregistry Custom Header Objects. (line 117) * RFC; RFC 5322 <14>: email headerregistry Custom Header Objects. (line 122) * RFC; RFC 5322 <15>: email headerregistry Custom Header Objects. (line 123) * RFC; RFC 5322 <16>: email headerregistry Custom Header Objects. (line 138) * RFC; RFC 5322 <17>: email headerregistry Custom Header Objects. (line 159) * RFC; RFC 5322 <18>: email headerregistry Custom Header Objects. (line 416) * RFC; RFC 5322 <19>: email headerregistry Custom Header Objects. (line 450) * RFC; RFC 5322 <20>: email headerregistry Custom Header Objects. (line 484) * RFC; RFC 5322 <21>: SMTP Objects. (line 317) * RFC; RFC 5424: SysLogHandler. (line 53) * RFC; RFC 5424 <1>: Inserting a BOM into messages sent to a SysLogHandler. (line 6) * RFC; RFC 5424 <2>: Inserting a BOM into messages sent to a SysLogHandler. (line 19) * RFC; RFC 5424 <3>: Inserting a BOM into messages sent to a SysLogHandler. (line 43) * RFC; RFC 5424#section-6: Inserting a BOM into messages sent to a SysLogHandler. (line 9) * RFC; RFC 5735: Address objects. (line 107) * RFC; RFC 5842: HTTP status codes. (line 46) * RFC; RFC 5842 <1>: HTTP status codes. (line 181) * RFC; RFC 5929: SSL Sockets. (line 247) * RFC; RFC 6066: Constants<9>. (line 377) * RFC; RFC 6066 <1>: SSL Contexts. (line 293) * RFC; RFC 6066 <2>: LibreSSL support. (line 45) * RFC; RFC 6125: Certificate handling. (line 11) * RFC; RFC 6125 <1>: Certificate handling. (line 29) * RFC; RFC 6152: smtpd. (line 17) * RFC; RFC 6152 <1>: SMTPServer Objects. (line 35) * RFC; RFC 6531: email<2>. (line 19) * RFC; RFC 6531 <1>: smtpd. (line 23) * RFC; RFC 6531 <2>: smtplib. (line 15) * RFC; RFC 6531 <3>: email message Representing an email message. (line 103) * RFC; RFC 6531 <4>: email policy Policy Objects. (line 369) * RFC; RFC 6531 <5>: smtplib — SMTP protocol client. (line 63) * RFC; RFC 6531 <6>: smtpd — SMTP Server. (line 26) * RFC; RFC 6531 <7>: SMTPServer Objects. (line 26) * RFC; RFC 6531 <8>: SMTPChannel Objects. (line 21) * RFC; RFC 6532: email<2>. (line 18) * RFC; RFC 6532 <1>: email — An email and MIME handling package. (line 15) * RFC; RFC 6532 <2>: email message Representing an email message. (line 20) * RFC; RFC 6532 <3>: Parser API. (line 42) * RFC; RFC 6532 <4>: email policy Policy Objects. (line 367) * RFC; RFC 6585: HTTP status codes. (line 145) * RFC; RFC 6585 <1>: HTTP status codes. (line 148) * RFC; RFC 6585 <2>: HTTP status codes. (line 151) * RFC; RFC 6585 <3>: HTTP status codes. (line 187) * RFC; RFC 6855: imaplib. (line 12) * RFC; RFC 6855 <1>: imaplib. (line 14) * RFC; RFC 6855 <2>: IMAP4 Objects. (line 88) * RFC; RFC 6855 <3>: IMAP4 Objects. (line 90) * RFC; RFC 6856: poplib. (line 6) * RFC; RFC 6856 <1>: POP3 Objects. (line 108) * RFC; RFC 7159: json — JSON encoder and decoder. (line 10) * RFC; RFC 7159 <1>: Standard Compliance and Interoperability. (line 6) * RFC; RFC 7159 <2>: Top-level Non-Object Non-Array Values. (line 9) * RFC; RFC 7230: urllib request — Extensible library for opening URLs. (line 197) * RFC; RFC 7230 <1>: HTTPConnection Objects. (line 151) * RFC; RFC 7231: HTTP status codes. (line 13) * RFC; RFC 7231 <1>: HTTP status codes. (line 16) * RFC; RFC 7231 <2>: HTTP status codes. (line 22) * RFC; RFC 7231 <3>: HTTP status codes. (line 25) * RFC; RFC 7231 <4>: HTTP status codes. (line 28) * RFC; RFC 7231 <5>: HTTP status codes. (line 31) * RFC; RFC 7231 <6>: HTTP status codes. (line 34) * RFC; RFC 7231 <7>: HTTP status codes. (line 37) * RFC; RFC 7231 <8>: HTTP status codes. (line 52) * RFC; RFC 7231 <9>: HTTP status codes. (line 55) * RFC; RFC 7231 <10>: HTTP status codes. (line 58) * RFC; RFC 7231 <11>: HTTP status codes. (line 61) * RFC; RFC 7231 <12>: HTTP status codes. (line 67) * RFC; RFC 7231 <13>: HTTP status codes. (line 70) * RFC; RFC 7231 <14>: HTTP status codes. (line 76) * RFC; RFC 7231 <15>: HTTP status codes. (line 82) * RFC; RFC 7231 <16>: HTTP status codes. (line 85) * RFC; RFC 7231 <17>: HTTP status codes. (line 88) * RFC; RFC 7231 <18>: HTTP status codes. (line 91) * RFC; RFC 7231 <19>: HTTP status codes. (line 94) * RFC; RFC 7231 <20>: HTTP status codes. (line 100) * RFC; RFC 7231 <21>: HTTP status codes. (line 103) * RFC; RFC 7231 <22>: HTTP status codes. (line 106) * RFC; RFC 7231 <23>: HTTP status codes. (line 109) * RFC; RFC 7231 <24>: HTTP status codes. (line 115) * RFC; RFC 7231 <25>: HTTP status codes. (line 118) * RFC; RFC 7231 <26>: HTTP status codes. (line 121) * RFC; RFC 7231 <27>: HTTP status codes. (line 127) * RFC; RFC 7231 <28>: HTTP status codes. (line 142) * RFC; RFC 7231 <29>: HTTP status codes. (line 157) * RFC; RFC 7231 <30>: HTTP status codes. (line 160) * RFC; RFC 7231 <31>: HTTP status codes. (line 163) * RFC; RFC 7231 <32>: HTTP status codes. (line 166) * RFC; RFC 7231 <33>: HTTP status codes. (line 169) * RFC; RFC 7231 <34>: HTTP status codes. (line 172) * RFC; RFC 7232: HTTP status codes. (line 64) * RFC; RFC 7232 <1>: HTTP status codes. (line 112) * RFC; RFC 7233: HTTP status codes. (line 40) * RFC; RFC 7233 <1>: HTTP status codes. (line 124) * RFC; RFC 7235: HTTP status codes. (line 79) * RFC; RFC 7235 <1>: HTTP status codes. (line 97) * RFC; RFC 7238: HTTP status codes. (line 73) * RFC; RFC 7301: Application-Layer Protocol Negotiation Support. (line 10) * RFC; RFC 7301 <1>: Constants<9>. (line 354) * RFC; RFC 7301 <2>: SSL Contexts. (line 258) * RFC; RFC 7525: LibreSSL support. (line 53) * RFC; RFC 7540: HTTP status codes. (line 130) * RFC; RFC 7693: BLAKE2. (line 6) * RFC; RFC 7725: HTTP status codes. (line 154) * RFC; RFC 7914: Key derivation. (line 48) * RFC; RFC 821: smtplib — SMTP protocol client. (line 12) * RFC; RFC 821 <1>: smtplib — SMTP protocol client. (line 179) * RFC; RFC 822: New and Improved Modules<3>. (line 97) * RFC; RFC 822 <1>: Functions<2>. (line 610) * RFC; RFC 822 <2>: Functions<2>. (line 613) * RFC; RFC 822 <3>: email Examples. (line 36) * RFC; RFC 822 <4>: email header Internationalized headers. (line 21) * RFC; RFC 822 <5>: HTTPConnection Objects. (line 138) * RFC; RFC 822 <6>: SMTP Objects. (line 94) * RFC; RFC 822 <7>: SMTP Objects. (line 232) * RFC; RFC 822 <8>: SMTP Objects. (line 233) * RFC; RFC 822 <9>: SMTP Example. (line 10) * RFC; RFC 822 <10>: The GNUTranslations class. (line 13) * RFC; RFC 822 <11>: distutils util — Miscellaneous other utility functions. (line 174) * RFC; RFC 8305: Opening network connections. (line 77) * RFC; RFC 8305 <1>: Opening network connections. (line 86) * RFC; RFC 854: telnetlib — Telnet client. (line 11) * RFC; RFC 854 <1>: telnetlib — Telnet client. (line 58) * RFC; RFC 959: ftplib — FTP protocol client. (line 16) * RFC; RFC 959 <1>: FTP Objects. (line 148) * RFC; RFC 977: nntplib — NNTP protocol client. (line 13) * RFC_4122 (in module uuid): uuid — UUID objects according to RFC 4122. (line 228) * rfile (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 110) * rfind() (bytearray method): Bytes and Bytearray Operations. (line 159) * rfind() (bytes method): Bytes and Bytearray Operations. (line 159) * rfind() (mmap.mmap method): mmap — Memory-mapped file support. (line 251) * rfind() (str method): String Methods<2>. (line 345) * rgb_to_hls() (in module colorsys): colorsys — Conversions between color systems. (line 36) * rgb_to_hsv() (in module colorsys): colorsys — Conversions between color systems. (line 44) * rgb_to_yiq() (in module colorsys): colorsys — Conversions between color systems. (line 28) * rglob() (pathlib.Path method): Methods<2>. (line 355) * richcmpfunc (C type): Slot Type typedefs. (line 91) * right (filecmp.dircmp attribute): The dircmp class. (line 45) * right() (in module turtle): Turtle motion. (line 40) * RIGHTSHIFT (in module token): token — Constants used with Python parse trees. (line 162) * RIGHTSHIFTEQUAL (in module token): token — Constants used with Python parse trees. (line 206) * right_list (filecmp.dircmp attribute): The dircmp class. (line 54) * right_only (filecmp.dircmp attribute): The dircmp class. (line 67) * rindex() (bytearray method): Bytes and Bytearray Operations. (line 173) * rindex() (bytes method): Bytes and Bytearray Operations. (line 173) * rindex() (str method): String Methods<2>. (line 352) * rjust() (bytearray method): Bytes and Bytearray Operations. (line 283) * rjust() (bytes method): Bytes and Bytearray Operations. (line 283) * rjust() (str method): String Methods<2>. (line 357) * rlcompleter (module): rlcompleter — Completion function for GNU readline. (line 6) * rlecode_hqx() (in module binascii): binascii — Convert between binary and ASCII. (line 95) * rledecode_hqx() (in module binascii): binascii — Convert between binary and ASCII. (line 83) * RLIMIT_AS (in module resource): Resource Limits. (line 147) * RLIMIT_CORE (in module resource): Resource Limits. (line 92) * RLIMIT_CPU (in module resource): Resource Limits. (line 99) * RLIMIT_DATA (in module resource): Resource Limits. (line 111) * RLIMIT_FSIZE (in module resource): Resource Limits. (line 107) * RLIMIT_MEMLOCK (in module resource): Resource Limits. (line 139) * RLIMIT_MSGQUEUE (in module resource): Resource Limits. (line 152) * RLIMIT_NICE (in module resource): Resource Limits. (line 160) * RLIMIT_NOFILE (in module resource): Resource Limits. (line 130) * RLIMIT_NPROC (in module resource): Resource Limits. (line 126) * RLIMIT_NPTS (in module resource): Resource Limits. (line 215) * RLIMIT_OFILE (in module resource): Resource Limits. (line 135) * RLIMIT_RSS (in module resource): Resource Limits. (line 121) * RLIMIT_RTPRIO (in module resource): Resource Limits. (line 169) * RLIMIT_RTTIME (in module resource): Resource Limits. (line 177) * RLIMIT_SBSIZE (in module resource): Resource Limits. (line 194) * RLIMIT_SIGPENDING (in module resource): Resource Limits. (line 186) * RLIMIT_STACK (in module resource): Resource Limits. (line 115) * RLIMIT_SWAP (in module resource): Resource Limits. (line 204) * RLIMIT_VMEM (in module resource): Resource Limits. (line 143) * RLIM_INFINITY (in module resource): Resource Limits. (line 20) * RLock (class in multiprocessing): Synchronization primitives. (line 102) * RLock (class in threading): RLock Objects. (line 23) * RLock() (multiprocessing.managers.SyncManager method): Managers. (line 186) * rmd() (ftplib.FTP method): FTP Objects. (line 225) * rmdir() (in module os): Files and Directories. (line 732) * rmdir() (in module test.support): test support — Utilities for the Python test suite. (line 177) * rmdir() (pathlib.Path method): Methods<2>. (line 367) * RMFF: chunk — Read IFF chunked data. (line 8) * rms() (in module audioop): audioop — Manipulate raw audio data. (line 193) * rmtree() (in module shutil): Directory and files operations. (line 255) * rmtree() (in module test.support): test support — Utilities for the Python test suite. (line 183) * RobotFileParser (class in urllib.robotparser): urllib robotparser — Parser for robots txt. (line 16) * robots.txt: urllib robotparser — Parser for robots txt. (line 8) * rollback() (sqlite3.Connection method): Connection Objects. (line 40) * rotate() (collections.deque method): deque objects. (line 109) * rotate() (decimal.Context method): Context objects. (line 481) * rotate() (decimal.Decimal method): Decimal objects. (line 515) * rotate() (logging.handlers.BaseRotatingHandler method): BaseRotatingHandler. (line 58) * RotatingFileHandler (class in logging.handlers): RotatingFileHandler. (line 9) * rotation_filename() (logging.handlers.BaseRotatingHandler method): BaseRotatingHandler. (line 41) * rotator (logging.handlers.BaseRotatingHandler attribute): BaseRotatingHandler. (line 32) * ROT_FOUR (opcode): Python Bytecode Instructions. (line 72) * ROT_THREE (opcode): Python Bytecode Instructions. (line 67) * ROT_TWO (opcode): Python Bytecode Instructions. (line 63) * round() (built-in function): Built-in Functions. (line 1437) * Rounded (class in decimal): Signals. (line 77) * ROUND_05UP (in module decimal): Rounding modes. (line 34) * ROUND_CEILING (in module decimal): Rounding modes. (line 6) * ROUND_DOWN (in module decimal): Rounding modes. (line 10) * ROUND_FLOOR (in module decimal): Rounding modes. (line 14) * ROUND_HALF_DOWN (in module decimal): Rounding modes. (line 18) * ROUND_HALF_EVEN (in module decimal): Rounding modes. (line 22) * ROUND_HALF_UP (in module decimal): Rounding modes. (line 26) * ROUND_UP (in module decimal): Rounding modes. (line 30) * Row (class in sqlite3): Row Objects. (line 6) * rowcount (sqlite3.Cursor attribute): Cursor Objects. (line 178) * row_factory (sqlite3.Connection attribute): Connection Objects. (line 301) * RPAR (in module token): token — Constants used with Python parse trees. (line 58) * rpartition() (bytearray method): Bytes and Bytearray Operations. (line 185) * rpartition() (bytes method): Bytes and Bytearray Operations. (line 185) * rpartition() (str method): String Methods<2>. (line 364) * rpc_paths (xmlrpc.server.SimpleXMLRPCRequestHandler attribute): SimpleXMLRPCServer Objects. (line 64) * rpop() (poplib.POP3 method): POP3 Objects. (line 46) * rset() (poplib.POP3 method): POP3 Objects. (line 74) * rshift() (in module operator): operator — Standard operators as functions. (line 148) * rsplit() (bytearray method): Bytes and Bytearray Operations. (line 295) * rsplit() (bytes method): Bytes and Bytearray Operations. (line 295) * rsplit() (str method): String Methods<2>. (line 372) * RSQB (in module token): token — Constants used with Python parse trees. (line 66) * rstrip() (bytearray method): Bytes and Bytearray Operations. (line 306) * rstrip() (bytes method): Bytes and Bytearray Operations. (line 306) * rstrip() (str method): String Methods<2>. (line 381) * rt() (in module turtle): Turtle motion. (line 40) * RTLD_DEEPBIND (in module os): Miscellaneous System Information. (line 141) * RTLD_GLOBAL (in module os): Miscellaneous System Information. (line 141) * RTLD_LAZY (in module os): Miscellaneous System Information. (line 141) * RTLD_LOCAL (in module os): Miscellaneous System Information. (line 141) * RTLD_NODELETE (in module os): Miscellaneous System Information. (line 141) * RTLD_NOLOAD (in module os): Miscellaneous System Information. (line 141) * RTLD_NOW (in module os): Miscellaneous System Information. (line 141) * ruler (cmd.Cmd attribute): Cmd Objects. (line 164) * run (pdb command): Debugger Commands. (line 322) * Run script: Format menu Editor window only. (line 53) * run() (bdb.Bdb method): bdb — Debugger framework. (line 363) * run() (contextvars.Context method): Manual Context Management. (line 31) * run() (distutils.cmd.Command method): Creating a new Distutils command. (line 40) * run() (doctest.DocTestRunner method): DocTestRunner objects. (line 95) * run() (in module asyncio): Running an asyncio Program. (line 6) * run() (in module pdb): pdb — The Python Debugger. (line 93) * run() (in module profile): profile and cProfile Module Reference. (line 9) * run() (in module subprocess): Using the subprocess Module. (line 15) * run() (multiprocessing.Process method): Process and exceptions. (line 33) * run() (pdb.Pdb method): pdb — The Python Debugger. (line 180) * run() (profile.Profile method): profile and cProfile Module Reference. (line 100) * run() (sched.scheduler method): Scheduler Objects. (line 51) * run() (test.support.BasicTestRunner method): test support — Utilities for the Python test suite. (line 1104) * run() (threading.Thread method): Thread Objects. (line 100) * run() (trace.Trace method): Programmatic Interface. (line 22) * run() (unittest.IsolatedAsyncioTestCase method): Test cases. (line 845) * run() (unittest.TestCase method): Test cases. (line 83) * run() (unittest.TestSuite method): Grouping tests. (line 41) * run() (unittest.TextTestRunner method): Loading and running tests. (line 481) * run() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 98) * runcall() (bdb.Bdb method): bdb — Debugger framework. (line 380) * runcall() (in module pdb): pdb — The Python Debugger. (line 112) * runcall() (pdb.Pdb method): pdb — The Python Debugger. (line 180) * runcall() (profile.Profile method): profile and cProfile Module Reference. (line 109) * runcode() (code.InteractiveInterpreter method): Interactive Interpreter Objects. (line 33) * runctx() (bdb.Bdb method): bdb — Debugger framework. (line 375) * runctx() (in module profile): profile and cProfile Module Reference. (line 23) * runctx() (profile.Profile method): profile and cProfile Module Reference. (line 104) * runctx() (trace.Trace method): Programmatic Interface. (line 28) * runeval() (bdb.Bdb method): bdb — Debugger framework. (line 369) * runeval() (in module pdb): pdb — The Python Debugger. (line 105) * runeval() (pdb.Pdb method): pdb — The Python Debugger. (line 180) * runfunc() (trace.Trace method): Programmatic Interface. (line 35) * running() (concurrent.futures.Future method): Future Objects. (line 28) * runpy (module): runpy — Locating and executing Python modules. (line 6) * runsource() (code.InteractiveInterpreter method): Interactive Interpreter Objects. (line 6) * RuntimeError: Concrete exceptions. (line 204) * RuntimeWarning: Warnings. (line 36) * runtime_checkable() (in module typing): Classes functions and decorators. (line 752) * runtime_library_dir_option() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 230) * run_coroutine_threadsafe() (in module asyncio): Scheduling From Other Threads. (line 6) * run_docstring_examples() (in module doctest): Basic API. (line 128) * run_doctest() (in module test.support): test support — Utilities for the Python test suite. (line 270) * run_forever() (asyncio.loop method): Running and stopping the loop. (line 16) * run_in_executor() (asyncio.loop method): Executing code in thread or process pools. (line 6) * run_in_subinterp() (in module test.support): test support — Utilities for the Python test suite. (line 951) * run_module() (in module runpy): runpy — Locating and executing Python modules. (line 27) * run_path() (in module runpy): runpy — Locating and executing Python modules. (line 95) * run_python_until_end() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 30) * run_script() (modulefinder.ModuleFinder method): modulefinder — Find modules used by a script. (line 44) * run_setup() (in module distutils.core): distutils core — Core Distutils functionality. (line 121) * run_unittest() (in module test.support): test support — Utilities for the Python test suite. (line 254) * run_until_complete() (asyncio.loop method): Running and stopping the loop. (line 6) * run_with_locale() (in module test.support): test support — Utilities for the Python test suite. (line 574) * run_with_tz() (in module test.support): test support — Utilities for the Python test suite. (line 582) * RUSAGE_BOTH (in module resource): Resource Usage. (line 122) * RUSAGE_CHILDREN (in module resource): Resource Usage. (line 116) * RUSAGE_SELF (in module resource): Resource Usage. (line 110) * RUSAGE_THREAD (in module resource): Resource Usage. (line 128) * RWF_DSYNC (in module os): File Descriptor Operations. (line 535) * RWF_HIPRI (in module os): File Descriptor Operations. (line 482) * RWF_NOWAIT (in module os): File Descriptor Operations. (line 467) * RWF_SYNC (in module os): File Descriptor Operations. (line 545) * R_OK (in module os): Files and Directories. (line 106) * S (in module re): Module Contents. (line 113) * safe (uuid.SafeUUID attribute): uuid — UUID objects according to RFC 4122. (line 31) * SafeChildWatcher (class in asyncio): Process Watchers. (line 118) * saferepr() (in module pprint): pprint — Data pretty printer. (line 145) * SafeUUID (class in uuid): uuid — UUID objects according to RFC 4122. (line 27) * safe_substitute() (string.Template method): Template strings. (line 50) * samefile() (in module os.path): os path — Common pathname manipulations. (line 323) * samefile() (pathlib.Path method): Methods<2>. (line 371) * SameFileError: Directory and files operations. (line 52) * sameopenfile() (in module os.path): os path — Common pathname manipulations. (line 339) * samestat() (in module os.path): os path — Common pathname manipulations. (line 350) * same_files (filecmp.dircmp attribute): The dircmp class. (line 85) * same_quantum() (decimal.Context method): Context objects. (line 485) * same_quantum() (decimal.Decimal method): Decimal objects. (line 527) * sample() (in module random): Functions for sequences. (line 67) * samples() (statistics.NormalDist method): NormalDist objects. (line 58) * save() (http.cookiejar.FileCookieJar method): CookieJar and FileCookieJar Objects. (line 105) * SAVEDCWD (in module test.support): test support — Utilities for the Python test suite. (line 87) * SaveKey() (in module winreg): Functions<11>. (line 400) * SaveSignals (class in test.support): test support — Utilities for the Python test suite. (line 1081) * savetty() (in module curses): Functions<3>. (line 427) * SAX2DOM (class in xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees. (line 82) * SAXException: xml sax — Support for SAX2 parsers. (line 86) * SAXNotRecognizedException: xml sax — Support for SAX2 parsers. (line 111) * SAXNotSupportedException: xml sax — Support for SAX2 parsers. (line 118) * SAXParseException: xml sax — Support for SAX2 parsers. (line 103) * scaleb() (decimal.Context method): Context objects. (line 489) * scaleb() (decimal.Decimal method): Decimal objects. (line 537) * scandir() (in module os): Files and Directories. (line 749) * scanf(): Simulating scanf. (line 6) * sched (module): sched — Event scheduler. (line 6) * scheduler (class in sched): sched — Event scheduler. (line 13) * SCHED_BATCH (in module os): Interface to the scheduler. (line 19) * SCHED_FIFO (in module os): Interface to the scheduler. (line 32) * sched_getaffinity() (in module os): Interface to the scheduler. (line 109) * sched_getparam() (in module os): Interface to the scheduler. (line 87) * sched_getscheduler() (in module os): Interface to the scheduler. (line 75) * sched_get_priority_max() (in module os): Interface to the scheduler. (line 63) * sched_get_priority_min() (in module os): Interface to the scheduler. (line 58) * SCHED_IDLE (in module os): Interface to the scheduler. (line 24) * SCHED_OTHER (in module os): Interface to the scheduler. (line 15) * sched_param (class in os): Interface to the scheduler. (line 46) * sched_priority (os.sched_param attribute): Interface to the scheduler. (line 54) * SCHED_RESET_ON_FORK (in module os): Interface to the scheduler. (line 40) * SCHED_RR (in module os): Interface to the scheduler. (line 36) * sched_rr_get_interval() (in module os): Interface to the scheduler. (line 93) * sched_setaffinity() (in module os): Interface to the scheduler. (line 102) * sched_setparam() (in module os): Interface to the scheduler. (line 81) * sched_setscheduler() (in module os): Interface to the scheduler. (line 68) * SCHED_SPORADIC (in module os): Interface to the scheduler. (line 28) * sched_yield() (in module os): Interface to the scheduler. (line 98) * schema (in module msilib): Precomputed tables. (line 10) * scope: Naming and binding. (line 6) * scope <1>: Resolution of names. (line 6) * Screen (class in turtle): Public classes. (line 30) * screensize() (in module turtle): Window control. (line 61) * script_from_examples() (in module doctest): Debugging. (line 72) * scroll() (curses.window method): Window Objects. (line 497) * ScrolledCanvas (class in turtle): Public classes. (line 34) * scrollok() (curses.window method): Window Objects. (line 501) * scrypt() (in module hashlib): Key derivation. (line 44) * seal() (in module unittest.mock): Sealing mocks. (line 6) * search() (imaplib.IMAP4 method): IMAP4 Objects. (line 216) * search() (in module re): Module Contents. (line 143) * search() (re.Pattern method): Regular Expression Objects. (line 9) * second (datetime.datetime attribute): datetime Objects. (line 285) * second (datetime.time attribute): time Objects. (line 58) * seconds since the epoch: time — Time access and conversions. (line 25) * secrets (module): secrets — Generate secure random numbers for managing secrets. (line 6) * SECTCRE (configparser.ConfigParser attribute): Customizing Parser Behaviour. (line 300) * sections() (configparser.ConfigParser method): ConfigParser Objects. (line 81) * secure (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 45) * secure hash algorithm, SHA1, SHA224, SHA256, SHA384, SHA512: hashlib — Secure hashes and message digests. (line 8) * Secure Sockets Layer: ssl — TLS/SSL wrapper for socket objects. (line 8) * see() (tkinter.ttk.Treeview method): ttk Treeview. (line 251) * seed() (in module random): Bookkeeping functions. (line 6) * seek() (chunk.Chunk method): chunk — Read IFF chunked data. (line 92) * seek() (io.IOBase method): I/O Base Classes. (line 104) * seek() (io.TextIOBase method): Text I/O<2>. (line 66) * seek() (mmap.mmap method): mmap — Memory-mapped file support. (line 261) * seekable() (io.IOBase method): I/O Base Classes. (line 129) * SEEK_CUR (in module os): File Descriptor Operations. (line 249) * SEEK_END (in module os): File Descriptor Operations. (line 249) * SEEK_SET (in module os): File Descriptor Operations. (line 249) * seen_greeting (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 69) * Select (class in tkinter.tix): Basic Widgets. (line 59) * select (module): select — Waiting for I/O completion. (line 6) * select() (imaplib.IMAP4 method): IMAP4 Objects. (line 233) * select() (in module select): select — Waiting for I/O completion. (line 110) * select() (selectors.BaseSelector method): Classes<3>. (line 108) * select() (tkinter.ttk.Notebook method): ttk Notebook. (line 53) * selected_alpn_protocol() (ssl.SSLSocket method): SSL Sockets. (line 253) * selected_npn_protocol() (ssl.SSLSocket method): SSL Sockets. (line 263) * selection() (tkinter.ttk.Treeview method): ttk Treeview. (line 259) * selection_add() (tkinter.ttk.Treeview method): ttk Treeview. (line 274) * selection_remove() (tkinter.ttk.Treeview method): ttk Treeview. (line 281) * selection_set() (tkinter.ttk.Treeview method): ttk Treeview. (line 267) * selection_toggle() (tkinter.ttk.Treeview method): ttk Treeview. (line 288) * selector (urllib.request.Request attribute): Request Objects. (line 34) * SelectorEventLoop (class in asyncio): Event Loop Implementations. (line 12) * SelectorKey (class in selectors): Classes<3>. (line 29) * selectors (module): selectors — High-level I/O multiplexing. (line 6) * SelectSelector (class in selectors): Classes<3>. (line 167) * Semaphore (class in asyncio): Semaphore. (line 6) * Semaphore (class in multiprocessing): Synchronization primitives. (line 167) * Semaphore (class in threading): Semaphore Objects. (line 19) * Semaphore() (multiprocessing.managers.SyncManager method): Managers. (line 191) * semaphores, binary: _thread — Low-level threading API. (line 6) * SEMI (in module token): token — Constants used with Python parse trees. (line 78) * send() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 200) * send() (coroutine method): Coroutine Objects. (line 23) * send() (generator method): Generator-iterator methods. (line 27) * send() (http.client.HTTPConnection method): HTTPConnection Objects. (line 170) * send() (imaplib.IMAP4 method): IMAP4 Objects. (line 240) * send() (logging.handlers.DatagramHandler method): DatagramHandler. (line 34) * send() (logging.handlers.SocketHandler method): SocketHandler. (line 63) * send() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 15) * send() (socket.socket method): Socket Objects. (line 381) * sendall() (socket.socket method): Socket Objects. (line 397) * sendcmd() (ftplib.FTP method): FTP Objects. (line 66) * sendfile() (asyncio.loop method): Transferring files. (line 6) * sendfile() (in module os): File Descriptor Operations. (line 576) * sendfile() (socket.socket method): Socket Objects. (line 488) * sendfile() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 275) * SendfileNotAvailableError: Exceptions<9>. (line 35) * sendmail() (smtplib.SMTP method): SMTP Objects. (line 229) * sendmsg() (socket.socket method): Socket Objects. (line 435) * sendmsg_afalg() (socket.socket method): Socket Objects. (line 477) * sendto() (asyncio.DatagramTransport method): Datagram Transports. (line 6) * sendto() (socket.socket method): Socket Objects. (line 416) * send_bytes() (multiprocessing.connection.Connection method): Connection Objects<2>. (line 54) * send_error() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 206) * send_flowing_data() (formatter.writer method): The Writer Interface. (line 76) * send_header() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 242) * send_hor_rule() (formatter.writer method): The Writer Interface. (line 68) * send_label_data() (formatter.writer method): The Writer Interface. (line 92) * send_line_break() (formatter.writer method): The Writer Interface. (line 54) * send_literal_data() (formatter.writer method): The Writer Interface. (line 83) * send_message() (smtplib.SMTP method): SMTP Objects. (line 307) * send_paragraph() (formatter.writer method): The Writer Interface. (line 58) * send_response() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 226) * send_response_only() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 255) * send_signal() (asyncio.asyncio.subprocess.Process method): Interacting with Subprocesses. (line 81) * send_signal() (asyncio.SubprocessTransport method): Subprocess Transports. (line 44) * send_signal() (subprocess.Popen method): Popen Objects. (line 74) * sentinel (in module unittest.mock): sentinel. (line 6) * sentinel (multiprocessing.Process attribute): Process and exceptions. (line 133) * sep (in module os): Miscellaneous System Information. (line 93) * sequence: Glossary. (line 1150) * Sequence (class in collections.abc): Collections Abstract Base Classes. (line 159) * Sequence (class in typing): Classes functions and decorators. (line 229) * sequence (in module msilib): Precomputed tables. (line 16) * sequence2st() (in module parser): Creating ST Objects. (line 26) * sequence; item: Subscriptions. (line 6) * sequence; iteration: Iterator Types. (line 6) * SequenceMatcher (class in difflib): SequenceMatcher Objects. (line 8) * serializing; objects: pickle — Python object serialization. (line 8) * Server (class in asyncio): Server Objects. (line 12) * server (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 71) * ServerProxy (class in xmlrpc.client): xmlrpc client — XML-RPC client access. (line 24) * server_activate() (socketserver.BaseServer method): Server Objects<2>. (line 164) * server_address (socketserver.BaseServer attribute): Server Objects<2>. (line 76) * server_bind() (socketserver.BaseServer method): Server Objects<2>. (line 170) * server_close() (socketserver.BaseServer method): Server Objects<2>. (line 61) * server_hostname (ssl.SSLSocket attribute): SSL Sockets. (line 335) * server_side (ssl.SSLSocket attribute): SSL Sockets. (line 328) * server_software (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 176) * server_version (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 127) * server_version (http.server.SimpleHTTPRequestHandler attribute): http server — HTTP servers. (line 344) * serve_forever() (asyncio.Server method): Server Objects. (line 63) * serve_forever() (socketserver.BaseServer method): Server Objects<2>. (line 32) * service_actions() (socketserver.BaseServer method): Server Objects<2>. (line 45) * session (ssl.SSLSocket attribute): SSL Sockets. (line 348) * session_reused (ssl.SSLSocket attribute): SSL Sockets. (line 358) * session_stats() (ssl.SSLContext method): SSL Contexts. (line 480) * set (built-in class): Set Types — set frozenset. (line 33) * Set (class in collections.abc): Collections Abstract Base Classes. (line 177) * Set (class in typing): Classes functions and decorators. (line 272) * Set Breakpoint: Help menu Shell and Editor. (line 30) * set comprehension: Glossary. (line 1169) * set() (asyncio.Event method): Event. (line 52) * set() (configparser.ConfigParser method): ConfigParser Objects. (line 250) * set() (configparser.RawConfigParser method): RawConfigParser Objects. (line 37) * set() (contextvars.ContextVar method): Context Variables. (line 46) * set() (http.cookies.Morsel method): Morsel Objects. (line 64) * set() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 72) * set() (test.support.EnvironmentVarGuard method): test support — Utilities for the Python test suite. (line 1036) * set() (threading.Event method): Event Objects. (line 27) * set() (tkinter.ttk.Combobox method): ttk Combobox. (line 19) * set() (tkinter.ttk.Spinbox method): ttk Spinbox. (line 12) * set() (tkinter.ttk.Treeview method): ttk Treeview. (line 295) * set() (xml.etree.ElementTree.Element method): Element Objects. (line 81) * set; comprehensions: Set displays. (line 6) * set; display: Set displays. (line 6) * setacl() (imaplib.IMAP4 method): IMAP4 Objects. (line 247) * setannotation() (imaplib.IMAP4 method): IMAP4 Objects. (line 252) * setattr() (built-in function): Built-in Functions. (line 1473) * setattrfunc (C type): Slot Type typedefs. (line 57) * setAttribute() (xml.dom.Element method): Element Objects<2>. (line 67) * setAttributeNode() (xml.dom.Element method): Element Objects<2>. (line 71) * setAttributeNodeNS() (xml.dom.Element method): Element Objects<2>. (line 79) * setAttributeNS() (xml.dom.Element method): Element Objects<2>. (line 87) * setattrofunc (C type): Slot Type typedefs. (line 69) * SetBase() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 22) * setblocking() (socket.socket method): Socket Objects. (line 512) * setByteStream() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 36) * setcbreak() (in module tty): tty — Terminal control functions. (line 24) * setCharacterStream() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 55) * setcheckinterval() (in module sys): sys — System-specific parameters and functions. (line 1196) * setcomptype() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 158) * setcomptype() (sunau.AU_write method): AU_write Objects. (line 28) * setcomptype() (wave.Wave_write method): Wave_write Objects. (line 51) * setContentHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 25) * setcontext() (in module decimal): Context objects. (line 18) * setDaemon() (threading.Thread method): Thread Objects. (line 197) * setdefault() (dict method): Mapping Types — dict. (line 205) * setdefault() (http.cookies.Morsel method): Morsel Objects. (line 108) * setdefaulttimeout() (in module socket): Other functions<2>. (line 339) * setdlopenflags() (in module sys): sys — System-specific parameters and functions. (line 1212) * setDocumentLocator() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 10) * setDTDHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 34) * setegid() (in module os): Process Parameters. (line 338) * setEncoding() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 22) * setEntityResolver() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 43) * setErrorHandler() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 54) * seteuid() (in module os): Process Parameters. (line 344) * setFeature() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 76) * setfirstweekday() (in module calendar): calendar — General calendar-related functions. (line 287) * setfmt() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 125) * setFormatter() (logging.Handler method): Handler Objects. (line 48) * setframerate() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 148) * setframerate() (sunau.AU_write method): AU_write Objects. (line 19) * setframerate() (wave.Wave_write method): Wave_write Objects. (line 38) * setgid() (in module os): Process Parameters. (line 350) * setgroups() (in module os): Process Parameters. (line 356) * seth() (in module turtle): Turtle motion. (line 132) * setheading() (in module turtle): Turtle motion. (line 132) * sethostname() (in module socket): Other functions<2>. (line 346) * SetInteger() (msilib.Record method): Record Objects. (line 32) * setitem() (in module operator): operator — Standard operators as functions. (line 201) * setitimer() (in module signal): Module contents<2>. (line 348) * setLevel() (logging.Handler method): Handler Objects. (line 35) * setLevel() (logging.Logger method): Logger Objects. (line 50) * setlocale() (in module locale): locale — Internationalization services. (line 27) * setLocale() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 60) * setLoggerClass() (in module logging): Module-Level Functions. (line 343) * setlogmask() (in module syslog): syslog — Unix syslog library routines. (line 73) * setLogRecordFactory() (in module logging): Module-Level Functions. (line 355) * setmark() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 176) * setMaxConns() (urllib.request.CacheFTPHandler method): CacheFTPHandler Objects. (line 13) * setmode() (in module msvcrt): File Operations. (line 38) * setName() (threading.Thread method): Thread Objects. (line 142) * setnchannels() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 140) * setnchannels() (sunau.AU_write method): AU_write Objects. (line 9) * setnchannels() (wave.Wave_write method): Wave_write Objects. (line 30) * setnframes() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 152) * setnframes() (sunau.AU_write method): AU_write Objects. (line 23) * setnframes() (wave.Wave_write method): Wave_write Objects. (line 45) * SetParamEntityParsing() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 54) * setparameters() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 189) * setparams() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 168) * setparams() (sunau.AU_write method): AU_write Objects. (line 33) * setparams() (wave.Wave_write method): Wave_write Objects. (line 56) * setpassword() (zipfile.ZipFile method): ZipFile Objects. (line 211) * setpgid() (in module os): Process Parameters. (line 379) * setpgrp() (in module os): Process Parameters. (line 371) * setpos() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 108) * setpos() (in module turtle): Turtle motion. (line 74) * setpos() (sunau.AU_read method): AU_read Objects. (line 60) * setpos() (wave.Wave_read method): Wave_read Objects. (line 69) * setposition() (in module turtle): Turtle motion. (line 74) * setpriority() (in module os): Process Parameters. (line 387) * setprofile() (in module sys): sys — System-specific parameters and functions. (line 1225) * setprofile() (in module threading): threading — Thread-based parallelism. (line 130) * SetProperty() (msilib.SummaryInformation method): Summary Information Objects. (line 22) * setProperty() (xml.sax.xmlreader.XMLReader method): XMLReader Objects. (line 90) * setPublicId() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 6) * setquota() (imaplib.IMAP4 method): IMAP4 Objects. (line 257) * setraw() (in module tty): tty — Terminal control functions. (line 18) * setrecursionlimit() (in module sys): sys — System-specific parameters and functions. (line 1277) * setregid() (in module os): Process Parameters. (line 404) * setresgid() (in module os): Process Parameters. (line 410) * setresuid() (in module os): Process Parameters. (line 418) * setreuid() (in module os): Process Parameters. (line 426) * setrlimit() (in module resource): Resource Limits. (line 31) * setsampwidth() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 144) * setsampwidth() (sunau.AU_write method): AU_write Objects. (line 13) * setsampwidth() (wave.Wave_write method): Wave_write Objects. (line 34) * setscrreg() (curses.window method): Window Objects. (line 511) * setsid() (in module os): Process Parameters. (line 439) * setsockopt() (socket.socket method): Socket Objects. (line 545) * setstate() (codecs.IncrementalDecoder method): IncrementalDecoder Objects. (line 60) * setstate() (codecs.IncrementalEncoder method): IncrementalEncoder Objects. (line 51) * setstate() (in module random): Bookkeeping functions. (line 34) * setStream() (logging.StreamHandler method): StreamHandler. (line 32) * SetStream() (msilib.Record method): Record Objects. (line 26) * SetString() (msilib.Record method): Record Objects. (line 21) * setswitchinterval() (in module sys): sys — System-specific parameters and functions. (line 1295) * setswitchinterval() (in module sys) <1>: Thread State and the Global Interpreter Lock. (line 15) * setswitchinterval() (in module test.support): test support — Utilities for the Python test suite. (line 281) * setSystemId() (xml.sax.xmlreader.InputSource method): InputSource Objects. (line 14) * setsyx() (in module curses): Functions<3>. (line 432) * setTarget() (logging.handlers.MemoryHandler method): MemoryHandler. (line 67) * settiltangle() (in module turtle): Appearance. (line 118) * settimeout() (socket.socket method): Socket Objects. (line 529) * setTimeout() (urllib.request.CacheFTPHandler method): CacheFTPHandler Objects. (line 9) * settrace() (in module sys): sys — System-specific parameters and functions. (line 1308) * settrace() (in module threading): threading — Thread-based parallelism. (line 123) * setuid() (in module os): Process Parameters. (line 446) * setundobuffer() (in module turtle): Special Turtle methods. (line 61) * setup() (in module distutils.core): distutils core — Core Distutils functionality. (line 12) * setup() (in module turtle): Methods specific to Screen not inherited from TurtleScreen. (line 20) * setup() (socketserver.BaseRequestHandler method): Request Handler Objects. (line 14) * setUp() (unittest.TestCase method): Test cases. (line 33) * setUpClass() (unittest.TestCase method): Test cases. (line 55) * setupterm() (in module curses): Functions<3>. (line 437) * SETUP_ANNOTATIONS (opcode): Python Bytecode Instructions. (line 357) * SETUP_ASYNC_WITH (opcode): Python Bytecode Instructions. (line 303) * setup_environ() (wsgiref.handlers.BaseHandler method): wsgiref handlers – server/gateway base classes. (line 196) * SETUP_FINALLY (opcode): Python Bytecode Instructions. (line 697) * setup_python() (venv.EnvBuilder method): API<2>. (line 91) * setup_scripts() (venv.EnvBuilder method): API<2>. (line 99) * setup_testing_defaults() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 68) * SETUP_WITH (opcode): Python Bytecode Instructions. (line 438) * SetValue() (in module winreg): Functions<11>. (line 424) * SetValueEx() (in module winreg): Functions<11>. (line 455) * setworldcoordinates() (in module turtle): Window control. (line 88) * setx() (in module turtle): Turtle motion. (line 104) * setxattr() (in module os): Linux extended attributes. (line 57) * sety() (in module turtle): Turtle motion. (line 118) * SET_ADD (opcode): Python Bytecode Instructions. (line 317) * set_all(): Reference Count Details. (line 98) * set_allowed_domains() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 70) * set_alpn_protocols() (ssl.SSLContext method): SSL Contexts. (line 252) * set_app() (wsgiref.simple_server.WSGIServer method): wsgiref simple_server – a simple WSGI HTTP server. (line 61) * set_asyncgen_hooks() (in module sys): sys — System-specific parameters and functions. (line 1404) * set_authorizer() (sqlite3.Connection method): Connection Objects. (line 194) * set_auto_history() (in module readline): History list. (line 43) * set_blocked_domains() (http.cookiejar.DefaultCookiePolicy method): DefaultCookiePolicy Objects. (line 56) * set_blocking() (in module os): File Descriptor Operations. (line 612) * set_boundary() (email.message.EmailMessage method): email message Representing an email message. (line 411) * set_boundary() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 587) * set_break() (bdb.Bdb method): bdb — Debugger framework. (line 281) * set_charset() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 235) * set_children() (tkinter.ttk.Treeview method): ttk Treeview. (line 25) * set_child_watcher() (asyncio.AbstractEventLoopPolicy method): Policy Objects. (line 42) * set_child_watcher() (in module asyncio): Process Watchers. (line 29) * set_ciphers() (ssl.SSLContext method): SSL Contexts. (line 238) * set_completer() (in module readline): Completion. (line 14) * set_completer_delims() (in module readline): Completion. (line 48) * set_completion_display_matches_hook() (in module readline): Completion. (line 57) * set_content() (email.contentmanager.ContentManager method): email contentmanager Managing MIME Content. (line 40) * set_content() (email.message.EmailMessage method): email message Representing an email message. (line 590) * set_content() (in module email.contentmanager): Content Manager Instances. (line 35) * set_continue() (bdb.Bdb method): bdb — Debugger framework. (line 266) * set_cookie() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 72) * set_cookie_if_ok() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 68) * set_coroutine_origin_tracking_depth() (in module sys): sys — System-specific parameters and functions. (line 1429) * set_current() (msilib.Feature method): Features<3>. (line 14) * set_data() (importlib.abc.SourceLoader method): importlib abc – Abstract base classes related to import. (line 568) * set_data() (importlib.machinery.SourceFileLoader method): importlib machinery – Importers and path hooks. (line 242) * set_date() (mailbox.MaildirMessage method): MaildirMessage. (line 97) * set_debug() (asyncio.loop method): Enabling debug mode. (line 14) * set_debug() (in module gc): gc — Garbage Collector interface. (line 48) * set_debuglevel() (ftplib.FTP method): FTP Objects. (line 13) * set_debuglevel() (http.client.HTTPConnection method): HTTPConnection Objects. (line 71) * set_debuglevel() (nntplib.NNTP method): Methods<3>. (line 307) * set_debuglevel() (poplib.POP3 method): POP3 Objects. (line 11) * set_debuglevel() (smtplib.SMTP method): SMTP Objects. (line 8) * set_debuglevel() (telnetlib.Telnet method): Telnet Objects. (line 84) * set_defaults() (argparse.ArgumentParser method): Parser defaults. (line 6) * set_defaults() (optparse.OptionParser method): Other methods. (line 27) * set_default_executor() (asyncio.loop method): Executing code in thread or process pools. (line 65) * set_default_type() (email.message.EmailMessage method): email message Representing an email message. (line 342) * set_default_type() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 450) * set_default_verify_paths() (ssl.SSLContext method): SSL Contexts. (line 229) * set_ecdh_curve() (ssl.SSLContext method): SSL Contexts. (line 368) * set_errno() (in module ctypes): Utility functions. (line 171) * set_event_loop() (asyncio.AbstractEventLoopPolicy method): Policy Objects. (line 23) * set_event_loop() (in module asyncio): Event Loop. (line 57) * set_event_loop_policy() (in module asyncio): Getting and Setting the Policy. (line 13) * set_exception() (asyncio.Future method): Future Object. (line 52) * set_exception() (concurrent.futures.Future method): Future Objects. (line 123) * set_exception_handler() (asyncio.loop method): Error Handling API. (line 8) * set_executable() (in module multiprocessing): Miscellaneous<3>. (line 107) * set_executables() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 235) * set_flags() (mailbox.MaildirMessage method): MaildirMessage. (line 72) * set_flags() (mailbox.mboxMessage method): mboxMessage. (line 72) * set_flags() (mailbox.MMDFMessage method): MMDFMessage. (line 71) * set_from() (mailbox.mboxMessage method): mboxMessage. (line 53) * set_from() (mailbox.MMDFMessage method): MMDFMessage. (line 52) * set_handle_inheritable() (in module os): Inheritance of File Descriptors. (line 38) * set_history_length() (in module readline): History file. (line 30) * set_include_dirs() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 103) * set_info() (mailbox.MaildirMessage method): MaildirMessage. (line 108) * set_inheritable() (in module os): Inheritance of File Descriptors. (line 28) * set_inheritable() (socket.socket method): Socket Objects. (line 505) * set_labels() (mailbox.BabylMessage method): BabylMessage. (line 51) * set_last_error() (in module ctypes): Utility functions. (line 180) * set_libraries() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 128) * set_library_dirs() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 144) * set_link_objects() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 187) * set_literal (2to3 fixer): Fixers. (line 288) * set_loader() (in module importlib.util): importlib util – Utility code for importers. (line 168) * set_match_tests() (in module test.support): test support — Utilities for the Python test suite. (line 250) * set_memlimit() (in module test.support): test support — Utilities for the Python test suite. (line 371) * set_name() (asyncio.Task method): Task Object. (line 220) * set_next() (bdb.Bdb method): bdb — Debugger framework. (line 248) * set_nonstandard_attr() (http.cookiejar.Cookie method): Cookie Objects<2>. (line 103) * set_npn_protocols() (ssl.SSLContext method): SSL Contexts. (line 272) * set_ok() (http.cookiejar.CookiePolicy method): CookiePolicy Objects. (line 9) * set_option_negotiation_callback() (telnetlib.Telnet method): Telnet Objects. (line 143) * set_output_charset() (gettext.NullTranslations method): The NullTranslations class. (line 94) * set_package() (in module importlib.util): importlib util – Utility code for importers. (line 183) * set_param() (email.message.EmailMessage method): email message Representing an email message. (line 351) * set_param() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 518) * set_pasv() (ftplib.FTP method): FTP Objects. (line 107) * set_payload() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 225) * set_policy() (http.cookiejar.CookieJar method): CookieJar and FileCookieJar Objects. (line 56) * set_position() (xdrlib.Unpacker method): Unpacker Objects. (line 16) * set_pre_input_hook() (in module readline): Startup hooks. (line 14) * set_progress_handler() (sqlite3.Connection method): Connection Objects. (line 218) * set_protocol() (asyncio.BaseTransport method): Base Transport. (line 80) * set_proxy() (urllib.request.Request method): Request Objects. (line 114) * set_python_build() (in module distutils.sysconfig): distutils sysconfig — System configuration information. (line 99) * set_quit() (bdb.Bdb method): bdb — Debugger framework. (line 271) * set_recsrc() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 89) * set_result() (asyncio.Future method): Future Object. (line 45) * set_result() (concurrent.futures.Future method): Future Objects. (line 111) * set_return() (bdb.Bdb method): bdb — Debugger framework. (line 252) * set_running_or_notify_cancel() (concurrent.futures.Future method): Future Objects. (line 89) * set_runtime_library_dirs() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 155) * set_seq1() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 54) * set_seq2() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 59) * set_seqs() (difflib.SequenceMatcher method): SequenceMatcher Objects. (line 44) * set_sequences() (mailbox.MH method): MH. (line 58) * set_sequences() (mailbox.MHMessage method): MHMessage. (line 37) * set_servername_callback (ssl.SSLContext attribute): SSL Contexts. (line 339) * set_server_documentation() (xmlrpc.server.DocCGIXMLRPCRequestHandler method): DocCGIXMLRPCRequestHandler. (line 24) * set_server_documentation() (xmlrpc.server.DocXMLRPCServer method): DocXMLRPCServer Objects. (line 24) * set_server_name() (xmlrpc.server.DocCGIXMLRPCRequestHandler method): DocCGIXMLRPCRequestHandler. (line 18) * set_server_name() (xmlrpc.server.DocXMLRPCServer method): DocXMLRPCServer Objects. (line 18) * set_server_title() (xmlrpc.server.DocCGIXMLRPCRequestHandler method): DocCGIXMLRPCRequestHandler. (line 13) * set_server_title() (xmlrpc.server.DocXMLRPCServer method): DocXMLRPCServer Objects. (line 13) * set_spacing() (formatter.formatter method): The Formatter Interface. (line 139) * set_startup_hook() (in module readline): Startup hooks. (line 6) * set_start_method() (in module multiprocessing): Miscellaneous<3>. (line 120) * set_step() (bdb.Bdb method): bdb — Debugger framework. (line 244) * set_subdir() (mailbox.MaildirMessage method): MaildirMessage. (line 58) * set_task_factory() (asyncio.loop method): Creating Futures and Tasks. (line 31) * set_terminator() (asynchat.async_chat method): asynchat — Asynchronous socket command/response handler. (line 117) * set_threshold() (in module gc): gc — Garbage Collector interface. (line 89) * set_trace() (bdb.Bdb method): bdb — Debugger framework. (line 261) * set_trace() (in module bdb): bdb — Debugger framework. (line 404) * set_trace() (in module pdb): pdb — The Python Debugger. (line 119) * set_trace() (pdb.Pdb method): pdb — The Python Debugger. (line 180) * set_trace_callback() (sqlite3.Connection method): Connection Objects. (line 232) * set_tunnel() (http.client.HTTPConnection method): HTTPConnection Objects. (line 81) * set_type() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 551) * set_unittest_reportflags() (in module doctest): Unittest API. (line 165) * set_unixfrom() (email.message.EmailMessage method): email message Representing an email message. (line 146) * set_unixfrom() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 157) * set_until() (bdb.Bdb method): bdb — Debugger framework. (line 256) * set_url() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 21) * set_usage() (optparse.OptionParser method): Other methods. (line 8) * set_userptr() (curses.panel.Panel method): Panel Objects. (line 43) * set_visible() (mailbox.BabylMessage method): BabylMessage. (line 68) * set_wakeup_fd() (in module signal): Module contents<2>. (line 377) * set_write_buffer_limits() (asyncio.WriteTransport method): Write-only Transports. (line 33) * SF_APPEND (in module stat): stat — Interpreting stat results. (line 374) * SF_ARCHIVED (in module stat): stat — Interpreting stat results. (line 366) * SF_IMMUTABLE (in module stat): stat — Interpreting stat results. (line 370) * SF_MNOWAIT (in module os): File Descriptor Operations. (line 625) * SF_NODISKIO (in module os): File Descriptor Operations. (line 625) * SF_NOUNLINK (in module stat): stat — Interpreting stat results. (line 378) * SF_SNAPSHOT (in module stat): stat — Interpreting stat results. (line 382) * SF_SYNC (in module os): File Descriptor Operations. (line 625) * Shape (class in turtle): Public classes. (line 43) * shape (memoryview attribute): Memory Views. (line 446) * shape() (in module turtle): Appearance. (line 6) * shapesize() (in module turtle): Appearance. (line 52) * shapetransform() (in module turtle): Appearance. (line 157) * share() (socket.socket method): Socket Objects. (line 575) * ShareableList (class in multiprocessing.shared_memory): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 243) * ShareableList() (multiprocessing.managers.SharedMemoryManager method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 203) * Shared Memory: multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 10) * SharedMemory (class in multiprocessing.shared_memory): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 33) * SharedMemory() (multiprocessing.managers.SharedMemoryManager method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 198) * SharedMemoryManager (class in multiprocessing.managers): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 171) * shared_ciphers() (ssl.SSLSocket method): SSL Sockets. (line 216) * shared_object_filename() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 474) * shearfactor() (in module turtle): Appearance. (line 84) * Shelf (class in shelve): Restrictions. (line 23) * shelve (module): shelve — Python object persistence. (line 6) * shield() (in module asyncio): Shielding From Cancellation. (line 6) * shift() (decimal.Context method): Context objects. (line 494) * shift() (decimal.Decimal method): Decimal objects. (line 543) * shifting; operation: Shifting operations. (line 6) * shifting; operations: Bitwise Operations on Integer Types. (line 6) * shift_path_info() (in module wsgiref.util): wsgiref util – WSGI environment utilities. (line 38) * shlex (class in shlex): shlex — Simple lexical analysis. (line 82) * shlex (module): shlex — Simple lexical analysis. (line 6) * shm (multiprocessing.shared_memory.ShareableList attribute): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 278) * shortDescription() (unittest.TestCase method): Test cases. (line 733) * shorten() (in module textwrap): textwrap — Text wrapping and filling. (line 40) * shouldFlush() (logging.handlers.BufferingHandler method): MemoryHandler. (line 35) * shouldFlush() (logging.handlers.MemoryHandler method): MemoryHandler. (line 71) * shouldStop (unittest.TestResult attribute): Loading and running tests. (line 268) * show() (curses.panel.Panel method): Panel Objects. (line 49) * showsyntaxerror() (code.InteractiveInterpreter method): Interactive Interpreter Objects. (line 44) * showtraceback() (code.InteractiveInterpreter method): Interactive Interpreter Objects. (line 53) * showturtle() (in module turtle): Visibility. (line 15) * showwarning() (in module warnings): Available Functions. (line 56) * show_code() (in module dis): Analysis functions. (line 26) * show_compilers() (in module distutils.ccompiler): distutils ccompiler — CCompiler base class. (line 62) * shuffle() (in module random): Functions for sequences. (line 49) * shutdown() (concurrent.futures.Executor method): Executor Objects. (line 56) * shutdown() (imaplib.IMAP4 method): IMAP4 Objects. (line 262) * shutdown() (in module logging): Module-Level Functions. (line 332) * shutdown() (multiprocessing.managers.BaseManager method): Managers. (line 67) * shutdown() (socket.socket method): Socket Objects. (line 568) * shutdown() (socketserver.BaseServer method): Server Objects<2>. (line 54) * shutdown_asyncgens() (asyncio.loop method): Running and stopping the loop. (line 56) * shutil (module): shutil — High-level file operations. (line 6) * side_effect (unittest.mock.Mock attribute): The Mock Class. (line 347) * SIGABRT (in module signal): Module contents<2>. (line 28) * SIGALRM (in module signal): Module contents<2>. (line 32) * SIGBREAK (in module signal): Module contents<2>. (line 38) * SIGBUS (in module signal): Module contents<2>. (line 44) * SIGCHLD (in module signal): Module contents<2>. (line 50) * SIGCLD (in module signal): Module contents<2>. (line 56) * SIGCONT (in module signal): Module contents<2>. (line 60) * SIGFPE (in module signal): Module contents<2>. (line 66) * SIGHUP (in module signal): Module contents<2>. (line 76) * SIGILL (in module signal): Module contents<2>. (line 83) * SIGINT: Signal Handling<2>. (line 8) * SIGINT <1>: Signal Handling<2>. (line 20) * SIGINT (in module signal): Module contents<2>. (line 87) * siginterrupt() (in module signal): Module contents<2>. (line 419) * SIGKILL (in module signal): Module contents<2>. (line 93) * signal (module): signal — Set handlers for asynchronous events. (line 6) * signal() (in module signal): Module contents<2>. (line 433) * Signature (class in inspect): Introspecting callables with the Signature object. (line 50) * signature (inspect.BoundArguments attribute): Introspecting callables with the Signature object. (line 308) * signature() (in module inspect): Introspecting callables with the Signature object. (line 12) * sigpending() (in module signal): Module contents<2>. (line 460) * SIGPIPE (in module signal): Module contents<2>. (line 101) * SIGSEGV (in module signal): Module contents<2>. (line 109) * SIGTERM (in module signal): Module contents<2>. (line 113) * sigtimedwait() (in module signal): Module contents<2>. (line 518) * SIGUSR1 (in module signal): Module contents<2>. (line 117) * SIGUSR2 (in module signal): Module contents<2>. (line 123) * sigwait() (in module signal): Module contents<2>. (line 474) * sigwaitinfo() (in module signal): Module contents<2>. (line 490) * SIGWINCH (in module signal): Module contents<2>. (line 129) * SIG_BLOCK (in module signal): Module contents<2>. (line 186) * SIG_DFL (in module signal): Module contents<2>. (line 15) * SIG_IGN (in module signal): Module contents<2>. (line 23) * SIG_SETMASK (in module signal): Module contents<2>. (line 201) * SIG_UNBLOCK (in module signal): Module contents<2>. (line 193) * Simple Mail Transfer Protocol: smtplib — SMTP protocol client. (line 8) * simple; statement: Simple statements. (line 6) * SimpleCookie (class in http.cookies): http cookies — HTTP state management. (line 48) * simplefilter() (in module warnings): Available Functions. (line 90) * SimpleHandler (class in wsgiref.handlers): wsgiref handlers – server/gateway base classes. (line 70) * SimpleHTTPRequestHandler (class in http.server): http server — HTTP servers. (line 331) * SimpleNamespace (class in types): Additional Utility Classes and Functions. (line 6) * SimpleQueue (class in multiprocessing): Pipes and Queues. (line 204) * SimpleQueue (class in queue): queue — A synchronized queue class. (line 75) * SimpleXMLRPCRequestHandler (class in xmlrpc.server): xmlrpc server — Basic XML-RPC servers. (line 58) * SimpleXMLRPCServer (class in xmlrpc.server): xmlrpc server — Basic XML-RPC servers. (line 19) * sin() (in module cmath): Trigonometric functions<2>. (line 29) * sin() (in module math): Trigonometric functions. (line 57) * single dispatch: Glossary. (line 1177) * SingleAddressHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 217) * singledispatch() (in module functools): functools — Higher-order functions and operations on callable objects. (line 319) * singledispatchmethod (class in functools): functools — Higher-order functions and operations on callable objects. (line 436) * singleton; tuple: The standard type hierarchy. (line 172) * sinh() (in module cmath): Hyperbolic functions<2>. (line 30) * sinh() (in module math): Hyperbolic functions. (line 25) * SIO_KEEPALIVE_VALS (in module socket): Constants<8>. (line 167) * SIO_LOOPBACK_FAST_PATH (in module socket): Constants<8>. (line 167) * SIO_RCVALL (in module socket): Constants<8>. (line 167) * site (module): site — Site-specific configuration hook. (line 6) * site command line option; –user-base: Command Line Interface<4>. (line 18) * site command line option; –user-site: Command Line Interface<4>. (line 22) * site-packages; directory: site — Site-specific configuration hook. (line 24) * site_maps() (urllib.robotparser.RobotFileParser method): urllib robotparser — Parser for robots txt. (line 71) * sixtofour (ipaddress.IPv6Address attribute): Address objects. (line 202) * size (multiprocessing.shared_memory.SharedMemory attribute): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 96) * size (struct.Struct attribute): Classes<2>. (line 62) * size (tarfile.TarInfo attribute): TarInfo Objects. (line 47) * size (tracemalloc.Statistic attribute): Statistic. (line 19) * size (tracemalloc.StatisticDiff attribute): StatisticDiff. (line 26) * size (tracemalloc.Trace attribute): Trace. (line 23) * size() (ftplib.FTP method): FTP Objects. (line 229) * size() (mmap.mmap method): mmap — Memory-mapped file support. (line 269) * Sized (class in collections.abc): Collections Abstract Base Classes. (line 112) * Sized (class in typing): Classes functions and decorators. (line 199) * sizeof() (in module ctypes): Utility functions. (line 189) * size_diff (tracemalloc.StatisticDiff attribute): StatisticDiff. (line 32) * SIZE_MAX: Integer Objects. (line 210) * SKIP (in module doctest): Option Flags. (line 103) * skip() (chunk.Chunk method): chunk — Read IFF chunked data. (line 113) * skip() (in module unittest): Skipping tests and expected failures. (line 85) * skipIf() (in module unittest): Skipping tests and expected failures. (line 90) * skipinitialspace (csv.Dialect attribute): Dialects and Formatting Parameters. (line 65) * skipped (unittest.TestResult attribute): Loading and running tests. (line 250) * skippedEntity() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 176) * SkipTest: Skipping tests and expected failures. (line 104) * skipTest() (unittest.TestCase method): Test cases. (line 97) * skipUnless() (in module unittest): Skipping tests and expected failures. (line 94) * skip_unless_bind_unix_socket() (in module test.support): test support — Utilities for the Python test suite. (line 563) * skip_unless_symlink() (in module test.support): test support — Utilities for the Python test suite. (line 554) * skip_unless_xattr() (in module test.support): test support — Utilities for the Python test suite. (line 559) * SLASH (in module token): token — Constants used with Python parse trees. (line 94) * SLASHEQUAL (in module token): token — Constants used with Python parse trees. (line 182) * slave() (nntplib.NNTP method): Methods<3>. (line 303) * sleep() (in module asyncio): Sleeping. (line 6) * sleep() (in module time): Functions<2>. (line 215) * slice: Slicings. (line 6) * slice <1>: Glossary. (line 1182) * slice (built-in class): Built-in Functions. (line 1482) * slice; assignment: Mutable Sequence Types. (line 16) * slice; operation: Common Sequence Operations. (line 21) * slicing: The standard type hierarchy. (line 133) * slicing <1>: The standard type hierarchy. (line 192) * slicing <2>: Slicings. (line 6) * slicing; assignment: Assignment statements. (line 126) * SMALLEST (in module test.support): test support — Utilities for the Python test suite. (line 155) * SMTP (class in smtplib): smtplib — SMTP protocol client. (line 16) * SMTP (in module email.policy): email policy Policy Objects. (line 493) * SMTP; protocol: smtplib — SMTP protocol client. (line 8) * SMTPAuthenticationError: smtplib — SMTP protocol client. (line 171) * SMTPChannel (class in smtpd): SMTPChannel Objects. (line 6) * SMTPConnectError: smtplib — SMTP protocol client. (line 156) * smtpd (module): smtpd — SMTP Server. (line 6) * SMTPDataError: smtplib — SMTP protocol client. (line 152) * SMTPException: smtplib — SMTP protocol client. (line 117) * SMTPHandler (class in logging.handlers): SMTPHandler. (line 10) * SMTPHeloError: smtplib — SMTP protocol client. (line 161) * smtplib (module): smtplib — SMTP protocol client. (line 6) * SMTPNotSupportedError: smtplib — SMTP protocol client. (line 165) * SMTPRecipientsRefused: smtplib — SMTP protocol client. (line 145) * SMTPResponseException: smtplib — SMTP protocol client. (line 131) * SMTPSenderRefused: smtplib — SMTP protocol client. (line 139) * SMTPServer (class in smtpd): SMTPServer Objects. (line 6) * SMTPServerDisconnected: smtplib — SMTP protocol client. (line 125) * SMTPUTF8 (in module email.policy): email policy Policy Objects. (line 499) * smtp_server (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 44) * SMTP_SSL (class in smtplib): smtplib — SMTP protocol client. (line 66) * smtp_state (smtpd.SMTPChannel attribute): SMTPChannel Objects. (line 63) * Snapshot (class in tracemalloc): Snapshot. (line 6) * sndhdr (module): sndhdr — Determine type of sound file. (line 6) * SND_ALIAS (in module winsound): winsound — Sound-playing interface for Windows. (line 47) * SND_ASYNC (in module winsound): winsound — Sound-playing interface for Windows. (line 109) * SND_FILENAME (in module winsound): winsound — Sound-playing interface for Windows. (line 42) * SND_LOOP (in module winsound): winsound — Sound-playing interface for Windows. (line 88) * SND_MEMORY (in module winsound): winsound — Sound-playing interface for Windows. (line 94) * SND_NODEFAULT (in module winsound): winsound — Sound-playing interface for Windows. (line 113) * SND_NOSTOP (in module winsound): winsound — Sound-playing interface for Windows. (line 118) * SND_NOWAIT (in module winsound): winsound — Sound-playing interface for Windows. (line 122) * SND_PURGE (in module winsound): winsound — Sound-playing interface for Windows. (line 103) * sniff() (csv.Sniffer method): Module Contents<3>. (line 211) * Sniffer (class in csv): Module Contents<3>. (line 204) * sni_callback (ssl.SSLContext attribute): SSL Contexts. (line 288) * socket (module): socket — Low-level networking interface. (line 6) * socket (socketserver.BaseServer attribute): Server Objects<2>. (line 85) * socket() (imaplib.IMAP4 method): IMAP4 Objects. (line 268) * socket() (in module socket): Creating sockets. (line 8) * socket() (in module socket) <1>: select — Waiting for I/O completion. (line 138) * SocketHandler (class in logging.handlers): SocketHandler. (line 10) * socketpair() (in module socket): Creating sockets. (line 60) * sockets (asyncio.Server attribute): Server Objects. (line 99) * socketserver (module): socketserver — A framework for network servers. (line 6) * SocketType (in module socket): Creating sockets. (line 173) * socket_type (socketserver.BaseServer attribute): Server Objects<2>. (line 108) * sock_accept() (asyncio.loop method): Working with socket objects directly. (line 74) * SOCK_CLOEXEC (in module socket): Constants<8>. (line 32) * sock_connect() (asyncio.loop method): Working with socket objects directly. (line 55) * SOCK_DGRAM (in module socket): Constants<8>. (line 21) * SOCK_MAX_SIZE (in module test.support): test support — Utilities for the Python test suite. (line 100) * SOCK_NONBLOCK (in module socket): Constants<8>. (line 32) * SOCK_RAW (in module socket): Constants<8>. (line 21) * SOCK_RDM (in module socket): Constants<8>. (line 21) * sock_recv() (asyncio.loop method): Working with socket objects directly. (line 12) * sock_recv_into() (asyncio.loop method): Working with socket objects directly. (line 26) * sock_sendall() (asyncio.loop method): Working with socket objects directly. (line 37) * sock_sendfile() (asyncio.loop method): Working with socket objects directly. (line 97) * SOCK_SEQPACKET (in module socket): Constants<8>. (line 21) * SOCK_STREAM (in module socket): Constants<8>. (line 21) * SOL_ALG (in module socket): Constants<8>. (line 183) * SOL_RDS (in module socket): Constants<8>. (line 154) * SOMAXCONN (in module socket): Constants<8>. (line 48) * sort() (imaplib.IMAP4 method): IMAP4 Objects. (line 272) * sort() (list method): Lists<2>. (line 39) * sortdict() (in module test.support): test support — Utilities for the Python test suite. (line 224) * sorted() (built-in function): Built-in Functions. (line 1498) * sortTestMethodsUsing (unittest.TestLoader attribute): Loading and running tests. (line 186) * sort_stats() (pstats.Stats method): The Stats Class. (line 67) * source (doctest.Example attribute): Example Objects. (line 17) * source (pdb command): Debugger Commands. (line 251) * source (shlex.shlex attribute): shlex Objects. (line 151) * source character set: Encoding declarations. (line 6) * SourceFileLoader (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 216) * sourcehook() (shlex.shlex method): shlex Objects. (line 26) * SourcelessFileLoader (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 256) * SourceLoader (class in importlib.abc): importlib abc – Abstract base classes related to import. (line 507) * SOURCE_DATE_EPOCH: py_compile<2>. (line 7) * SOURCE_DATE_EPOCH <1>: py_compile — Compile Python source files. (line 65) * SOURCE_DATE_EPOCH <2>: py_compile — Compile Python source files. (line 81) * SOURCE_DATE_EPOCH <3>: py_compile — Compile Python source files. (line 85) * SOURCE_DATE_EPOCH <4>: Command-line use. (line 85) * source_from_cache() (in module imp): imp — Access the import internals. (line 228) * source_from_cache() (in module importlib.util): importlib util – Utility code for importers. (line 58) * source_hash() (in module importlib.util): importlib util – Utility code for importers. (line 217) * SOURCE_SUFFIXES (in module importlib.machinery): importlib machinery – Importers and path hooks. (line 13) * source_to_code() (importlib.abc.InspectLoader static method): importlib abc – Abstract base classes related to import. (line 422) * space: Indentation. (line 6) * space; in printf-style formatting: printf-style String Formatting. (line 66) * space; in printf-style formatting <1>: printf-style Bytes Formatting. (line 63) * space; in string formatting: Format Specification Mini-Language. (line 71) * span() (re.Match method): Match Objects. (line 157) * spawn() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 488) * spawn() (in module pty): pty — Pseudo-terminal utilities. (line 36) * spawnl() (in module os): Process Management. (line 500) * spawnle() (in module os): Process Management. (line 500) * spawnlp() (in module os): Process Management. (line 500) * spawnlpe() (in module os): Process Management. (line 500) * spawnv() (in module os): Process Management. (line 500) * spawnve() (in module os): Process Management. (line 500) * spawnvp() (in module os): Process Management. (line 500) * spawnvpe() (in module os): Process Management. (line 500) * spawn_python() (in module test.support.script_helper): test support script_helper — Utilities for the Python execution tests. (line 59) * special method: Glossary. (line 1190) * special; attribute: The standard type hierarchy. (line 13) * special; method: Glossary. (line 1194) * specified_attributes (xml.parsers.expat.xmlparser attribute): XMLParser Objects<2>. (line 117) * spec_from_file_location() (in module importlib.util): importlib util – Utility code for importers. (line 205) * spec_from_loader() (in module importlib.util): importlib util – Utility code for importers. (line 194) * speed() (in module turtle): Turtle motion. (line 302) * speed() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 140) * Spinbox (class in tkinter.ttk): ttk Spinbox. (line 6) * split() (bytearray method): Bytes and Bytearray Operations. (line 329) * split() (bytes method): Bytes and Bytearray Operations. (line 329) * split() (in module os.path): os path — Common pathname manipulations. (line 364) * split() (in module re): Module Contents. (line 176) * split() (in module shlex): shlex — Simple lexical analysis. (line 17) * split() (re.Pattern method): Regular Expression Objects. (line 74) * split() (str method): String Methods<2>. (line 394) * splitdrive() (in module os.path): os path — Common pathname manipulations. (line 379) * splitext() (in module os.path): os path — Common pathname manipulations. (line 400) * splitlines() (bytearray method): Bytes and Bytearray Operations. (line 572) * splitlines() (bytes method): Bytes and Bytearray Operations. (line 572) * splitlines() (str method): String Methods<2>. (line 434) * SplitResult (class in urllib.parse): Structured Parse Results. (line 55) * SplitResultBytes (class in urllib.parse): Structured Parse Results. (line 82) * split_quoted() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 98) * SpooledTemporaryFile() (in module tempfile): tempfile — Generate temporary files and directories. (line 93) * sprintf-style formatting: printf-style String Formatting. (line 6) * sprintf-style formatting <1>: printf-style Bytes Formatting. (line 6) * spwd (module): spwd — The shadow password database. (line 6) * sqlite3 (module): sqlite3 — DB-API 2 0 interface for SQLite databases. (line 6) * sqlite_version (in module sqlite3): Module functions and constants. (line 16) * sqlite_version_info (in module sqlite3): Module functions and constants. (line 20) * sqrt() (decimal.Context method): Context objects. (line 498) * sqrt() (decimal.Decimal method): Decimal objects. (line 554) * sqrt() (in module cmath): Power and logarithmic functions<2>. (line 23) * sqrt() (in module math): Power and logarithmic functions. (line 74) * ssizeargfunc (C type): Slot Type typedefs. (line 116) * ssizeobjargproc (C type): Slot Type typedefs. (line 118) * SSL: ssl — TLS/SSL wrapper for socket objects. (line 8) * ssl (module): ssl — TLS/SSL wrapper for socket objects. (line 6) * SSLCertVerificationError: Exceptions<12>. (line 79) * SSLContext (class in ssl): SSL Contexts. (line 14) * SSLEOFError: Exceptions<12>. (line 71) * SSLError: Exceptions<12>. (line 6) * SSLErrorNumber (class in ssl): Constants<9>. (line 511) * SSLKEYLOGFILE: Context creation. (line 33) * SSLKEYLOGFILE <1>: Context creation. (line 67) * SSLObject (class in ssl): Memory BIO Support<2>. (line 30) * sslobject_class (ssl.SSLContext attribute): SSL Contexts. (line 471) * SSLSession (class in ssl): SSL session. (line 8) * SSLSocket (class in ssl): SSL Sockets. (line 6) * sslsocket_class (ssl.SSLContext attribute): SSL Contexts. (line 445) * SSLSyscallError: Exceptions<12>. (line 62) * SSLv3 (ssl.TLSVersion attribute): Constants<9>. (line 533) * SSLWantReadError: Exceptions<12>. (line 44) * SSLWantWriteError: Exceptions<12>. (line 53) * SSLZeroReturnError: Exceptions<12>. (line 35) * SSL_CERT_FILE: LibreSSL support. (line 15) * SSL_CERT_PATH: LibreSSL support. (line 15) * ssl_version (ftplib.FTP_TLS attribute): FTP_TLS Objects. (line 9) * st() (in module turtle): Visibility. (line 15) * st2list() (in module parser): Converting ST Objects. (line 11) * st2tuple() (in module parser): Converting ST Objects. (line 31) * stack (traceback.TracebackException attribute): TracebackException Objects. (line 34) * stack viewer: Debug menu Shell window only. (line 15) * stack() (in module inspect): The interpreter stack. (line 84) * stack; trace: The standard type hierarchy. (line 757) * stackable; streams: codecs — Codec registry and base classes. (line 8) * StackSummary (class in traceback): StackSummary Objects. (line 11) * stack_effect() (in module dis): Analysis functions. (line 141) * stack_size() (in module threading): threading — Thread-based parallelism. (line 137) * stack_size() (in module _thread): _thread — Low-level threading API. (line 94) * stamp() (in module turtle): Turtle motion. (line 238) * Standard C: String and Bytes literals. (line 72) * standard input: Complete Python programs. (line 25) * standard; output: Expression statements. (line 17) * standarderror (2to3 fixer): Fixers. (line 293) * standard_b64decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 79) * standard_b64encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 74) * standend() (curses.window method): Window Objects. (line 516) * standout() (curses.window method): Window Objects. (line 521) * STAR (in module token): token — Constants used with Python parse trees. (line 90) * STAREQUAL (in module token): token — Constants used with Python parse trees. (line 178) * starmap() (in module itertools): Itertool functions. (line 518) * starmap() (multiprocessing.pool.Pool method): Process Pools. (line 148) * starmap_async() (multiprocessing.pool.Pool method): Process Pools. (line 159) * start (range attribute): Ranges. (line 60) * start (slice object attribute): The standard type hierarchy. (line 803) * start (slice object attribute) <1>: Slicings. (line 26) * start (UnicodeError attribute): Concrete exceptions. (line 354) * start() (in module tracemalloc): Functions<9>. (line 50) * start() (logging.handlers.QueueListener method): QueueListener. (line 71) * start() (multiprocessing.managers.BaseManager method): Managers. (line 40) * start() (multiprocessing.Process method): Process and exceptions. (line 43) * start() (re.Match method): Match Objects. (line 132) * start() (threading.Thread method): Thread Objects. (line 89) * start() (tkinter.ttk.Progressbar method): ttk Progressbar. (line 8) * start() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 43) * StartCdataSectionHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 300) * StartDoctypeDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 186) * startDocument() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 32) * startElement() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 82) * StartElementHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 224) * startElementNS() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 102) * startfile() (in module os): Process Management. (line 611) * STARTF_USESHOWWINDOW (in module subprocess): Windows Constants. (line 33) * STARTF_USESTDHANDLES (in module subprocess): Windows Constants. (line 27) * StartNamespaceDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 279) * startPrefixMapping() (xml.sax.handler.ContentHandler method): ContentHandler Objects. (line 49) * startswith() (bytearray method): Bytes and Bytearray Operations. (line 198) * startswith() (bytes method): Bytes and Bytearray Operations. (line 198) * startswith() (str method): String Methods<2>. (line 507) * startTest() (unittest.TestResult method): Loading and running tests. (line 331) * startTestRun() (unittest.TestResult method): Loading and running tests. (line 340) * starttls() (imaplib.IMAP4 method): IMAP4 Objects. (line 290) * starttls() (nntplib.NNTP method): Methods<3>. (line 62) * starttls() (smtplib.SMTP method): SMTP Objects. (line 185) * STARTUPINFO (class in subprocess): Windows Popen Helpers. (line 9) * start_color() (in module curses): Functions<3>. (line 445) * start_component() (msilib.Directory method): Directory Objects. (line 20) * start_new_thread() (in module _thread): _thread — Low-level threading API. (line 32) * start_ns() (xml.etree.ElementTree.TreeBuilder method): TreeBuilder Objects. (line 75) * start_server() (in module asyncio): Streams. (line 65) * start_serving() (asyncio.Server method): Server Objects. (line 47) * start_threads() (in module test.support): test support — Utilities for the Python test suite. (line 526) * start_tls() (asyncio.loop method): TLS Upgrade. (line 6) * start_unix_server() (in module asyncio): Streams. (line 118) * stat (module): stat — Interpreting stat results. (line 6) * stat() (in module os): Files and Directories. (line 976) * stat() (nntplib.NNTP method): Methods<3>. (line 219) * stat() (os.DirEntry method): Files and Directories. (line 947) * stat() (pathlib.Path method): Methods<2>. (line 35) * stat() (poplib.POP3 method): POP3 Objects. (line 51) * state() (tkinter.ttk.Widget method): ttk Widget. (line 25) * statement: Glossary. (line 1197) * statement grouping: Indentation. (line 6) * statement; assert: The assert statement. (line 6) * statement; assert <1>: Concrete exceptions. (line 10) * statement; assignment, annotated: Annotated assignment statements. (line 6) * statement; assignment, augmented: Augmented assignment statements. (line 6) * statement; async def: Coroutines<2>. (line 8) * statement; async for: Coroutine function definition. (line 26) * statement; async with: The async for statement. (line 43) * statement; break: The break statement. (line 6) * statement; break <1>: The while statement. (line 17) * statement; break <2>: The for statement. (line 22) * statement; break <3>: The try statement. (line 79) * statement; break <4>: The try statement. (line 108) * statement; class: Class definitions. (line 6) * statement; continue: The continue statement. (line 6) * statement; continue <1>: The while statement. (line 17) * statement; continue <2>: The for statement. (line 22) * statement; continue <3>: The try statement. (line 79) * statement; continue <4>: The try statement. (line 108) * statement; def: Function definitions. (line 6) * statement; del: Basic customization. (line 56) * statement; del <1>: The del statement<2>. (line 6) * statement; del <2>: Mutable Sequence Types. (line 16) * statement; del <3>: Mapping Types — dict. (line 6) * statement; except: Built-in Exceptions. (line 6) * statement; for: for Statements. (line 6) * statement; for <1>: The break statement. (line 6) * statement; for <2>: The continue statement. (line 6) * statement; for <3>: The for statement. (line 6) * statement; global: The del statement<2>. (line 15) * statement; global <1>: The global statement. (line 6) * statement; if: The if statement. (line 6) * statement; if <1>: Truth Value Testing. (line 6) * statement; import: The standard type hierarchy. (line 521) * statement; import <1>: The import statement. (line 6) * statement; import <2>: Built-in Functions. (line 1775) * statement; import <3>: site — Site-specific configuration hook. (line 45) * statement; import <4>: imp — Access the import internals. (line 11) * statement; nonlocal: The nonlocal statement. (line 6) * statement; pass: The pass statement. (line 6) * statement; raise: The raise statement. (line 6) * statement; raise <1>: Built-in Exceptions. (line 14) * statement; return: The return statement. (line 6) * statement; return <1>: The try statement. (line 79) * statement; return <2>: The try statement. (line 108) * statement; try: The standard type hierarchy. (line 780) * statement; try <1>: The try statement. (line 6) * statement; try <2>: Built-in Exceptions. (line 6) * statement; while: The break statement. (line 6) * statement; while <1>: The continue statement. (line 6) * statement; while <2>: The while statement. (line 6) * statement; while <3>: Truth Value Testing. (line 6) * statement; with: With Statement Context Managers. (line 14) * statement; with <1>: The with statement. (line 6) * statement; yield: The yield statement. (line 6) * staticmethod() (built-in function): Built-in Functions. (line 1525) * Statistic (class in tracemalloc): Statistic. (line 6) * StatisticDiff (class in tracemalloc): StatisticDiff. (line 6) * statistics (module): statistics — Mathematical statistics functions. (line 6) * statistics() (tracemalloc.Snapshot method): Snapshot. (line 56) * StatisticsError: Exceptions<3>. (line 8) * Stats (class in pstats): The Stats Class. (line 9) * status (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 51) * status() (imaplib.IMAP4 method): IMAP4 Objects. (line 303) * statvfs() (in module os): Files and Directories. (line 1236) * stat_result (class in os): Files and Directories. (line 1031) * StdButtonBox (class in tkinter.tix): Basic Widgets. (line 65) * stderr (asyncio.asyncio.subprocess.Process attribute): Interacting with Subprocesses. (line 120) * stderr (in module sys): The standard type hierarchy. (line 630) * stderr (in module sys) <1>: sys — System-specific parameters and functions. (line 1463) * stderr (in module sys) <2>: Sub-interpreter support. (line 26) * stderr (subprocess.CalledProcessError attribute): Using the subprocess Module. (line 214) * stderr (subprocess.CompletedProcess attribute): Using the subprocess Module. (line 119) * stderr (subprocess.Popen attribute): Popen Objects. (line 123) * stderr (subprocess.TimeoutExpired attribute): Using the subprocess Module. (line 181) * stdev (statistics.NormalDist attribute): NormalDist objects. (line 35) * stdev() (in module statistics): Function details. (line 335) * stdin (asyncio.asyncio.subprocess.Process attribute): Interacting with Subprocesses. (line 110) * stdin (in module sys): The standard type hierarchy. (line 630) * stdin (in module sys) <1>: sys — System-specific parameters and functions. (line 1463) * stdin (in module sys) <2>: Sub-interpreter support. (line 26) * stdin (subprocess.Popen attribute): Popen Objects. (line 104) * stdin; stdout; sdterr: Process-wide parameters. (line 9) * stdio: The standard type hierarchy. (line 630) * stdout (asyncio.asyncio.subprocess.Process attribute): Interacting with Subprocesses. (line 115) * STDOUT (in module subprocess): Using the subprocess Module. (line 147) * stdout (in module sys): The standard type hierarchy. (line 630) * stdout (in module sys) <1>: sys — System-specific parameters and functions. (line 1463) * stdout (in module sys) <2>: Sub-interpreter support. (line 26) * stdout (subprocess.CalledProcessError attribute): Using the subprocess Module. (line 210) * stdout (subprocess.CompletedProcess attribute): Using the subprocess Module. (line 109) * stdout (subprocess.Popen attribute): Popen Objects. (line 113) * stdout (subprocess.TimeoutExpired attribute): Using the subprocess Module. (line 177) * STD_ERROR_HANDLE (in module subprocess): Windows Constants. (line 18) * STD_INPUT_HANDLE (in module subprocess): Windows Constants. (line 8) * STD_OUTPUT_HANDLE (in module subprocess): Windows Constants. (line 13) * step (pdb command): Debugger Commands. (line 162) * step (range attribute): Ranges. (line 69) * step (slice object attribute): The standard type hierarchy. (line 803) * step (slice object attribute) <1>: Slicings. (line 26) * step() (tkinter.ttk.Progressbar method): ttk Progressbar. (line 15) * stereocontrols() (ossaudiodev.oss_mixer_device method): Mixer Device Objects. (line 44) * stls() (poplib.POP3 method): POP3 Objects. (line 113) * stop (range attribute): Ranges. (line 65) * stop (slice object attribute): The standard type hierarchy. (line 803) * stop (slice object attribute) <1>: Slicings. (line 26) * stop() (asyncio.loop method): Running and stopping the loop. (line 31) * stop() (in module tracemalloc): Functions<9>. (line 76) * stop() (logging.handlers.QueueListener method): QueueListener. (line 78) * stop() (tkinter.ttk.Progressbar method): ttk Progressbar. (line 21) * stop() (unittest.TestResult method): Loading and running tests. (line 311) * StopAsyncIteration: Concrete exceptions. (line 240) * StopIteration: Concrete exceptions. (line 210) * stopListening() (in module logging.config): Configuration functions. (line 164) * stopTest() (unittest.TestResult method): Loading and running tests. (line 335) * stopTestRun() (unittest.TestResult method): Loading and running tests. (line 346) * stop_here() (bdb.Bdb method): bdb — Debugger framework. (line 191) * storbinary() (ftplib.FTP method): FTP Objects. (line 112) * store() (imaplib.IMAP4 method): IMAP4 Objects. (line 307) * STORE_ACTIONS (optparse.Option attribute): Adding new actions. (line 35) * STORE_ATTR (opcode): Python Bytecode Instructions. (line 510) * STORE_DEREF (opcode): Python Bytecode Instructions. (line 745) * STORE_FAST (opcode): Python Bytecode Instructions. (line 716) * STORE_GLOBAL (opcode): Python Bytecode Instructions. (line 519) * STORE_NAME (opcode): Python Bytecode Instructions. (line 483) * STORE_SUBSCR (opcode): Python Bytecode Instructions. (line 250) * storlines() (ftplib.FTP method): FTP Objects. (line 126) * str (built-in class): Text Sequence Type — str. (line 44) * str (built-in class); (see also string): Ranges. (line 125) * str() (in module locale): locale — Internationalization services. (line 435) * strcoll() (in module locale): locale — Internationalization services. (line 375) * StreamError: tarfile — Read and write tar archive files. (line 196) * StreamHandler (class in logging): StreamHandler. (line 11) * StreamReader (class in asyncio): StreamReader. (line 6) * StreamReader (class in codecs): StreamReader Objects. (line 10) * streamreader (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 87) * StreamReaderWriter (class in codecs): StreamReaderWriter Objects. (line 12) * StreamRecoder (class in codecs): StreamRecoder Objects. (line 13) * StreamRequestHandler (class in socketserver): Request Handler Objects. (line 42) * streams: codecs — Codec registry and base classes. (line 8) * StreamWriter (class in asyncio): StreamWriter. (line 6) * StreamWriter (class in codecs): StreamWriter Objects. (line 10) * streamwriter (codecs.CodecInfo attribute): codecs — Codec registry and base classes. (line 87) * strerror (OSError attribute): Concrete exceptions. (line 151) * strerror(): Raising exceptions. (line 59) * strerror() (in module os): Process Parameters. (line 452) * strftime() (datetime.date method): date Objects. (line 267) * strftime() (datetime.datetime method): datetime Objects. (line 700) * strftime() (datetime.time method): time Objects. (line 209) * strftime() (in module time): Functions<2>. (line 230) * strict (csv.Dialect attribute): Dialects and Formatting Parameters. (line 70) * strict (in module email.policy): email policy Policy Objects. (line 514) * strict_domain (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 95) * strict_errors() (in module codecs): Error Handlers. (line 128) * strict_ns_domain (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 117) * strict_ns_set_initial_dollar (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 122) * strict_ns_set_path (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 127) * strict_ns_unverifiable (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 112) * strict_rfc2965_unverifiable (http.cookiejar.DefaultCookiePolicy attribute): DefaultCookiePolicy Objects. (line 103) * strides (memoryview attribute): Memory Views. (line 454) * STRING (in module token): token — Constants used with Python parse trees. (line 46) * string (module): string — Common string operations. (line 6) * string (re.Match attribute): Match Objects. (line 196) * string literal: Literals. (line 8) * string; conversion: Basic customization. (line 150) * string; conversion <1>: Expression statements. (line 17) * string; format() (built-in function): Built-in Functions. (line 643) * string; formatted literal: String literal concatenation. (line 24) * string; formatting, printf: printf-style String Formatting. (line 6) * string; immutable sequences: The standard type hierarchy. (line 154) * string; interpolated literal: String literal concatenation. (line 24) * string; interpolation, printf: printf-style String Formatting. (line 6) * string; item: Subscriptions. (line 38) * string; methods: Text Sequence Type — str. (line 85) * string; object representation: Finalization and De-allocation. (line 79) * string; PyObject_Str (C function): Object Protocol. (line 186) * string; str (built-in class): Text Sequence Type — str. (line 44) * string; str() (built-in function): Built-in Functions. (line 1558) * string; text sequence type: Ranges. (line 125) * string; __format__() (object method): Basic customization. (line 150) * string; __str__() (object method): Basic customization. (line 129) * StringIO (class in io): Text I/O<2>. (line 193) * stringprep (module): stringprep — Internet String Preparation. (line 6) * strings, documentation: Defining Functions. (line 21) * strings, documentation <1>: Documentation Strings. (line 6) * string_at() (in module ctypes): Utility functions. (line 194) * strip() (bytearray method): Bytes and Bytearray Operations. (line 375) * strip() (bytes method): Bytes and Bytearray Operations. (line 375) * strip() (str method): String Methods<2>. (line 514) * stripspaces (curses.textpad.Textbox attribute): Textbox objects. (line 115) * strip_dirs() (pstats.Stats method): The Stats Class. (line 34) * strip_python_strerr() (in module test.support): test support — Utilities for the Python test suite. (line 386) * strptime() (datetime.datetime class method): datetime Objects. (line 231) * strptime() (in module time): Functions<2>. (line 362) * strsignal() (in module signal): Module contents<2>. (line 249) * strtobool() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 119) * Struct (class in struct): Classes<2>. (line 8) * struct (module): struct — Interpret bytes as packed binary data. (line 6) * Structure (class in ctypes): Structured data types. (line 21) * struct_time (class in time): Functions<2>. (line 396) * strxfrm() (in module locale): locale — Internationalization services. (line 382) * STType (in module parser): ST Objects. (line 10) * Style (class in tkinter.ttk): Ttk Styling. (line 20) * ST_ATIME (in module stat): stat — Interpreting stat results. (line 163) * st_atime (os.stat_result attribute): Files and Directories. (line 1076) * st_atime_ns (os.stat_result attribute): Files and Directories. (line 1092) * st_birthtime (os.stat_result attribute): Files and Directories. (line 1160) * st_blksize (os.stat_result attribute): Files and Directories. (line 1138) * st_blocks (os.stat_result attribute): Files and Directories. (line 1133) * st_creator (os.stat_result attribute): Files and Directories. (line 1178) * ST_CTIME (in module stat): stat — Interpreting stat results. (line 171) * st_ctime (os.stat_result attribute): Files and Directories. (line 1084) * st_ctime_ns (os.stat_result attribute): Files and Directories. (line 1102) * ST_DEV (in module stat): stat — Interpreting stat results. (line 142) * st_dev (os.stat_result attribute): Files and Directories. (line 1052) * st_file_attributes (os.stat_result attribute): Files and Directories. (line 1188) * st_flags (os.stat_result attribute): Files and Directories. (line 1148) * st_fstype (os.stat_result attribute): Files and Directories. (line 1167) * st_gen (os.stat_result attribute): Files and Directories. (line 1156) * ST_GID (in module stat): stat — Interpreting stat results. (line 154) * st_gid (os.stat_result attribute): Files and Directories. (line 1064) * ST_INO (in module stat): stat — Interpreting stat results. (line 138) * st_ino (os.stat_result attribute): Files and Directories. (line 1043) * ST_MODE (in module stat): stat — Interpreting stat results. (line 134) * st_mode (os.stat_result attribute): Files and Directories. (line 1039) * ST_MTIME (in module stat): stat — Interpreting stat results. (line 167) * st_mtime (os.stat_result attribute): Files and Directories. (line 1080) * st_mtime_ns (os.stat_result attribute): Files and Directories. (line 1097) * ST_NLINK (in module stat): stat — Interpreting stat results. (line 146) * st_nlink (os.stat_result attribute): Files and Directories. (line 1056) * st_rdev (os.stat_result attribute): Files and Directories. (line 1144) * st_reparse_tag (os.stat_result attribute): Files and Directories. (line 1195) * st_rsize (os.stat_result attribute): Files and Directories. (line 1174) * ST_SIZE (in module stat): stat — Interpreting stat results. (line 158) * st_size (os.stat_result attribute): Files and Directories. (line 1068) * st_type (os.stat_result attribute): Files and Directories. (line 1182) * ST_UID (in module stat): stat — Interpreting stat results. (line 150) * st_uid (os.stat_result attribute): Files and Directories. (line 1060) * sub() (in module operator): operator — Standard operators as functions. (line 153) * sub() (in module re): Module Contents. (line 241) * sub() (re.Pattern method): Regular Expression Objects. (line 91) * subclassing; immutable types: Basic customization. (line 8) * subdirs (filecmp.dircmp attribute): The dircmp class. (line 100) * SubElement() (in module xml.etree.ElementTree): Functions<6>. (line 192) * submit() (concurrent.futures.Executor method): Executor Objects. (line 12) * submodule_search_locations (importlib.machinery.ModuleSpec attribute): importlib machinery – Importers and path hooks. (line 391) * subn() (in module re): Module Contents. (line 306) * subn() (re.Pattern method): Regular Expression Objects. (line 96) * subnets() (ipaddress.IPv4Network method): Network objects. (line 170) * subnets() (ipaddress.IPv6Network method): Network objects. (line 340) * subnet_of() (ipaddress.IPv4Network method): Network objects. (line 212) * subnet_of() (ipaddress.IPv6Network method): Network objects. (line 344) * Subnormal (class in decimal): Signals. (line 86) * suboffsets (memoryview attribute): Memory Views. (line 463) * subpad() (curses.window method): Window Objects. (line 525) * subprocess (module): subprocess — Subprocess management. (line 6) * SubprocessError: Using the subprocess Module. (line 153) * SubprocessProtocol (class in asyncio): Base Protocols. (line 24) * SubprocessTransport (class in asyncio): Transports Hierarchy. (line 50) * subprocess_exec() (asyncio.loop method): Running Subprocesses. (line 15) * subprocess_shell() (asyncio.loop method): Running Subprocesses. (line 112) * subscribe() (imaplib.IMAP4 method): IMAP4 Objects. (line 331) * subscript; assignment: Mutable Sequence Types. (line 16) * subscript; operation: Common Sequence Operations. (line 21) * subscription: The standard type hierarchy. (line 127) * subscription <1>: The standard type hierarchy. (line 192) * subscription <2>: The standard type hierarchy. (line 249) * subscription <3>: Subscriptions. (line 6) * subscription; assignment: Assignment statements. (line 103) * subsequent_indent (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 205) * substitute() (string.Template method): Template strings. (line 40) * subst_vars() (in module distutils.util): distutils util — Miscellaneous other utility functions. (line 82) * subTest() (unittest.TestCase method): Test cases. (line 105) * subtract() (collections.Counter method): Counter objects. (line 88) * subtract() (decimal.Context method): Context objects. (line 502) * subtraction: Binary arithmetic operations. (line 66) * subtype (email.headerregistry.ContentTypeHeader attribute): email headerregistry Custom Header Objects. (line 278) * subwin() (curses.window method): Window Objects. (line 532) * sub_commands (distutils.cmd.Command attribute): Creating a new Distutils command. (line 49) * successful() (multiprocessing.pool.AsyncResult method): Process Pools. (line 213) * suffix_map (in module mimetypes): mimetypes — Map filenames to MIME types. (line 128) * suffix_map (mimetypes.MimeTypes attribute): MimeTypes Objects. (line 23) * suite: Compound statements. (line 18) * suite() (in module parser): Creating ST Objects. (line 18) * suiteClass (unittest.TestLoader attribute): Loading and running tests. (line 192) * sum() (built-in function): Built-in Functions. (line 1568) * summarize() (doctest.DocTestRunner method): DocTestRunner objects. (line 116) * summarize_address_range() (in module ipaddress): Other Module Level Functions. (line 27) * sum_list(): Reference Count Details. (line 143) * sum_sequence(): Reference Count Details. (line 170) * sum_sequence() <1>: Exceptions<18>. (line 65) * sunau (module): sunau — Read and write Sun AU files. (line 6) * super (pyclbr.Class attribute): Class Objects<2>. (line 38) * super() (built-in function): Built-in Functions. (line 1584) * supernet() (ipaddress.IPv4Network method): Network objects. (line 196) * supernet() (ipaddress.IPv6Network method): Network objects. (line 342) * supernet_of() (ipaddress.IPv4Network method): Network objects. (line 223) * supernet_of() (ipaddress.IPv6Network method): Network objects. (line 346) * SupportsAbs (class in typing): Classes functions and decorators. (line 181) * SupportsBytes (class in typing): Classes functions and decorators. (line 171) * SupportsComplex (class in typing): Classes functions and decorators. (line 167) * SupportsFloat (class in typing): Classes functions and decorators. (line 163) * SupportsIndex (class in typing): Classes functions and decorators. (line 175) * SupportsInt (class in typing): Classes functions and decorators. (line 159) * SupportsRound (class in typing): Classes functions and decorators. (line 186) * supports_bytes_environ (in module os): Process Parameters. (line 458) * supports_dir_fd (in module os): Files and Directories. (line 1279) * supports_effective_ids (in module os): Files and Directories. (line 1304) * supports_fd (in module os): Files and Directories. (line 1323) * supports_follow_symlinks (in module os): Files and Directories. (line 1342) * supports_unicode_filenames (in module os.path): os path — Common pathname manipulations. (line 409) * suppress() (in module contextlib): Utilities. (line 178) * SuppressCrashReport (class in test.support): test support — Utilities for the Python test suite. (line 1045) * swapcase() (bytearray method): Bytes and Bytearray Operations. (line 596) * swapcase() (bytes method): Bytes and Bytearray Operations. (line 596) * swapcase() (str method): String Methods<2>. (line 538) * swap_attr() (in module test.support): test support — Utilities for the Python test suite. (line 487) * swap_item() (in module test.support): test support — Utilities for the Python test suite. (line 504) * SW_HIDE (in module subprocess): Windows Constants. (line 23) * Symbol (class in symtable): Examining Symbol Tables. (line 103) * symbol (module): symbol — Constants used with Python parse trees. (line 6) * SymbolTable (class in symtable): Examining Symbol Tables. (line 6) * symlink() (in module os): Files and Directories. (line 1365) * symlink_to() (pathlib.Path method): Methods<2>. (line 390) * symmetric_difference() (frozenset method): Set Types — set frozenset. (line 116) * symmetric_difference_update() (frozenset method): Set Types — set frozenset. (line 188) * symtable (module): symtable — Access to the compiler’s symbol tables. (line 6) * symtable() (in module symtable): Generating Symbol Tables. (line 6) * sym_name (in module symbol): symbol — Constants used with Python parse trees. (line 19) * sync() (dbm.dumb.dumbdbm method): dbm dumb — Portable DBM implementation. (line 78) * sync() (dbm.gnu.gdbm method): dbm gnu — GNU’s reinterpretation of dbm. (line 113) * sync() (in module os): Files and Directories. (line 1407) * sync() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 165) * sync() (shelve.Shelf method): shelve — Python object persistence. (line 63) * syncdown() (curses.window method): Window Objects. (line 542) * synchronized() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 88) * SyncManager (class in multiprocessing.managers): Managers. (line 133) * syncok() (curses.window method): Window Objects. (line 548) * syncup() (curses.window method): Window Objects. (line 553) * syntax: Notation. (line 6) * SyntaxErr: Exceptions<16>. (line 93) * SyntaxError: Concrete exceptions. (line 247) * SyntaxWarning: Warnings. (line 32) * sys (module): sys — System-specific parameters and functions. (line 6) * sys.exc_info: The standard type hierarchy. (line 757) * sys.last_traceback: The standard type hierarchy. (line 757) * sys.meta_path: The meta path. (line 6) * sys.modules: The module cache. (line 6) * sys.path: Path entry finders. (line 6) * sys.path_hooks: Path entry finders. (line 6) * sys.path_importer_cache: Path entry finders. (line 6) * sys.stderr: The standard type hierarchy. (line 630) * sys.stdin: The standard type hierarchy. (line 630) * sys.stdout: The standard type hierarchy. (line 630) * sysconf() (in module os): Miscellaneous System Information. (line 56) * sysconfig (module): sysconfig — Provide access to Python’s configuration information. (line 6) * sysconf_names (in module os): Miscellaneous System Information. (line 66) * syslog (module): syslog — Unix syslog library routines. (line 6) * syslog() (in module syslog): syslog — Unix syslog library routines. (line 18) * SysLogHandler (class in logging.handlers): SysLogHandler. (line 10) * system() (in module os): Process Management. (line 647) * system() (in module platform): Cross Platform. (line 120) * SystemError: Concrete exceptions. (line 268) * SystemError (built-in exception): Module Objects. (line 55) * SystemError (built-in exception) <1>: Module Objects. (line 81) * SystemExit: Concrete exceptions. (line 282) * SystemExit (built-in exception): Exceptions<2>. (line 26) * systemId (xml.dom.DocumentType attribute): DocumentType Objects. (line 22) * SystemRandom (class in random): Alternative Generator. (line 11) * SystemRandom (class in secrets): Random numbers. (line 9) * SystemRoot: Popen Constructor. (line 234) * system_alias() (in module platform): Cross Platform. (line 126) * system_must_validate_cert() (in module test.support): test support — Utilities for the Python test suite. (line 219) * sys_exc (2to3 fixer): Fixers. (line 297) * sys_version (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 134) * S_ENFMT (in module stat): stat — Interpreting stat results. (line 317) * S_IEXEC (in module stat): stat — Interpreting stat results. (line 331) * S_IFBLK (in module stat): stat — Interpreting stat results. (line 206) * S_IFCHR (in module stat): stat — Interpreting stat results. (line 214) * S_IFDIR (in module stat): stat — Interpreting stat results. (line 210) * S_IFDOOR (in module stat): stat — Interpreting stat results. (line 222) * S_IFIFO (in module stat): stat — Interpreting stat results. (line 218) * S_IFLNK (in module stat): stat — Interpreting stat results. (line 198) * S_IFMT() (in module stat): stat — Interpreting stat results. (line 78) * S_IFPORT (in module stat): stat — Interpreting stat results. (line 228) * S_IFREG (in module stat): stat — Interpreting stat results. (line 202) * S_IFSOCK (in module stat): stat — Interpreting stat results. (line 194) * S_IFWHT (in module stat): stat — Interpreting stat results. (line 234) * S_IMODE() (in module stat): stat — Interpreting stat results. (line 71) * S_IREAD (in module stat): stat — Interpreting stat results. (line 323) * S_IRGRP (in module stat): stat — Interpreting stat results. (line 289) * S_IROTH (in module stat): stat — Interpreting stat results. (line 305) * S_IRUSR (in module stat): stat — Interpreting stat results. (line 273) * S_IRWXG (in module stat): stat — Interpreting stat results. (line 285) * S_IRWXO (in module stat): stat — Interpreting stat results. (line 301) * S_IRWXU (in module stat): stat — Interpreting stat results. (line 269) * S_ISBLK() (in module stat): stat — Interpreting stat results. (line 30) * S_ISCHR() (in module stat): stat — Interpreting stat results. (line 25) * S_ISDIR() (in module stat): stat — Interpreting stat results. (line 21) * S_ISDOOR() (in module stat): stat — Interpreting stat results. (line 50) * S_ISFIFO() (in module stat): stat — Interpreting stat results. (line 38) * S_ISGID (in module stat): stat — Interpreting stat results. (line 251) * S_ISLNK() (in module stat): stat — Interpreting stat results. (line 42) * S_ISPORT() (in module stat): stat — Interpreting stat results. (line 56) * S_ISREG() (in module stat): stat — Interpreting stat results. (line 34) * S_ISSOCK() (in module stat): stat — Interpreting stat results. (line 46) * S_ISUID (in module stat): stat — Interpreting stat results. (line 247) * S_ISVTX (in module stat): stat — Interpreting stat results. (line 262) * S_ISWHT() (in module stat): stat — Interpreting stat results. (line 62) * S_IWGRP (in module stat): stat — Interpreting stat results. (line 293) * S_IWOTH (in module stat): stat — Interpreting stat results. (line 309) * S_IWRITE (in module stat): stat — Interpreting stat results. (line 327) * S_IWUSR (in module stat): stat — Interpreting stat results. (line 277) * S_IXGRP (in module stat): stat — Interpreting stat results. (line 297) * S_IXOTH (in module stat): stat — Interpreting stat results. (line 313) * S_IXUSR (in module stat): stat — Interpreting stat results. (line 281) * tab: Indentation. (line 6) * tab() (tkinter.ttk.Notebook method): ttk Notebook. (line 62) * TabError: Concrete exceptions. (line 263) * tabnanny (module): tabnanny — Detection of ambiguous indentation. (line 6) * tabs() (tkinter.ttk.Notebook method): ttk Notebook. (line 71) * tabsize (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 162) * tag (xml.etree.ElementTree.Element attribute): Element Objects. (line 16) * tagName (xml.dom.Element attribute): Element Objects<2>. (line 9) * tag_bind() (tkinter.ttk.Treeview method): ttk Treeview. (line 303) * tag_configure() (tkinter.ttk.Treeview method): ttk Treeview. (line 309) * tag_has() (tkinter.ttk.Treeview method): ttk Treeview. (line 319) * tail (xml.etree.ElementTree.Element attribute): Element Objects. (line 21) * takewhile() (in module itertools): Itertool functions. (line 533) * take_snapshot() (in module tracemalloc): Functions<9>. (line 88) * tan() (in module cmath): Trigonometric functions<2>. (line 33) * tan() (in module math): Trigonometric functions. (line 61) * tanh() (in module cmath): Hyperbolic functions<2>. (line 34) * tanh() (in module math): Hyperbolic functions. (line 29) * TarError: tarfile — Read and write tar archive files. (line 182) * TarFile (class in tarfile): TarFile Objects. (line 22) * tarfile (module): tarfile — Read and write tar archive files. (line 6) * tarfile command line option; -c ... : Command-line options<2>. (line 11) * tarfile command line option; –create ... : Command-line options<2>. (line 11) * tarfile command line option; -e []: Command-line options<2>. (line 16) * tarfile command line option; –extract []: Command-line options<2>. (line 16) * tarfile command line option; -l : Command-line options<2>. (line 6) * tarfile command line option; –list : Command-line options<2>. (line 6) * tarfile command line option; -t : Command-line options<2>. (line 22) * tarfile command line option; –test : Command-line options<2>. (line 22) * tarfile command line option; -v: Command-line options<2>. (line 27) * tarfile command line option; –verbose: Command-line options<2>. (line 27) * target: Assignment statements. (line 27) * target (xml.dom.ProcessingInstruction attribute): ProcessingInstruction Objects. (line 9) * target; list: Assignment statements. (line 27) * target; list <1>: The for statement. (line 6) * target; list; assignment: Assignment statements. (line 35) * TarInfo (class in tarfile): TarInfo Objects. (line 15) * Task (class in asyncio): Task Object. (line 6) * task_done() (asyncio.Queue method): Queue. (line 78) * task_done() (multiprocessing.JoinableQueue method): Pipes and Queues. (line 227) * task_done() (queue.Queue method): Queue Objects. (line 68) * tau (in module cmath): Constants<3>. (line 14) * tau (in module math): Constants<2>. (line 14) * tbreak (pdb command): Debugger Commands. (line 88) * tb_frame (traceback attribute): The standard type hierarchy. (line 780) * tb_lasti (traceback attribute): The standard type hierarchy. (line 780) * tb_lineno (traceback attribute): The standard type hierarchy. (line 780) * tb_locals (unittest.TestResult attribute): Loading and running tests. (line 295) * tb_next (traceback attribute): The standard type hierarchy. (line 789) * tcdrain() (in module termios): termios — POSIX style tty control. (line 53) * tcflow() (in module termios): termios — POSIX style tty control. (line 64) * tcflush() (in module termios): termios — POSIX style tty control. (line 58) * tcgetattr() (in module termios): termios — POSIX style tty control. (line 26) * tcgetpgrp() (in module os): File Descriptor Operations. (line 653) * Tcl() (in module tkinter): Tkinter Modules. (line 33) * TCL_LIBRARY: How do I freeze Tkinter applications?. (line 11) * TCPServer (class in socketserver): socketserver — A framework for network servers. (line 15) * tcsendbreak() (in module termios): termios — POSIX style tty control. (line 47) * tcsetattr() (in module termios): termios — POSIX style tty control. (line 37) * tcsetpgrp() (in module os): File Descriptor Operations. (line 660) * tearDown() (unittest.TestCase method): Test cases. (line 41) * tearDownClass() (unittest.TestCase method): Test cases. (line 69) * tee() (in module itertools): Itertool functions. (line 546) * tell() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 112) * tell() (chunk.Chunk method): chunk — Read IFF chunked data. (line 101) * tell() (io.IOBase method): I/O Base Classes. (line 135) * tell() (io.TextIOBase method): Text I/O<2>. (line 88) * tell() (mmap.mmap method): mmap — Memory-mapped file support. (line 274) * tell() (sunau.AU_read method): AU_read Objects. (line 65) * tell() (sunau.AU_write method): AU_write Objects. (line 39) * tell() (wave.Wave_read method): Wave_read Objects. (line 73) * tell() (wave.Wave_write method): Wave_write Objects. (line 62) * Telnet (class in telnetlib): telnetlib — Telnet client. (line 25) * telnetlib (module): telnetlib — Telnet client. (line 6) * TEMP: tempfile — Generate temporary files and directories. (line 239) * tempdir (in module tempfile): tempfile — Generate temporary files and directories. (line 281) * tempfile (module): tempfile — Generate temporary files and directories. (line 6) * Template (class in pipes): pipes — Interface to shell pipelines. (line 19) * Template (class in string): Template strings. (line 35) * template (string.Template attribute): Template strings. (line 70) * temporary; file: tempfile — Generate temporary files and directories. (line 8) * temporary; file name: tempfile — Generate temporary files and directories. (line 8) * TemporaryDirectory() (in module tempfile): tempfile — Generate temporary files and directories. (line 119) * TemporaryFile() (in module tempfile): tempfile — Generate temporary files and directories. (line 28) * temp_cwd() (in module test.support): test support — Utilities for the Python test suite. (line 445) * temp_dir() (in module test.support): test support — Utilities for the Python test suite. (line 426) * temp_umask() (in module test.support): test support — Utilities for the Python test suite. (line 459) * teredo (ipaddress.IPv6Address attribute): Address objects. (line 209) * TERM: Functions<3>. (line 440) * TERM <1>: Functions<3>. (line 467) * termattrs() (in module curses): Functions<3>. (line 459) * terminal_size (class in os): Querying the size of a terminal. (line 25) * terminate() (asyncio.asyncio.subprocess.Process method): Interacting with Subprocesses. (line 90) * terminate() (asyncio.SubprocessTransport method): Subprocess Transports. (line 49) * terminate() (multiprocessing.pool.Pool method): Process Pools. (line 174) * terminate() (multiprocessing.Process method): Process and exceptions. (line 149) * terminate() (subprocess.Popen method): Popen Objects. (line 83) * termination model: Exceptions<2>. (line 20) * termios (module): termios — POSIX style tty control. (line 6) * termname() (in module curses): Functions<3>. (line 465) * ternary; operator: Conditional expressions. (line 6) * ternaryfunc (C type): Slot Type typedefs. (line 113) * test (doctest.DocTestFailure attribute): Debugging. (line 195) * test (doctest.UnexpectedException attribute): Debugging. (line 216) * test (module): test — Regression tests package for Python. (line 6) * test() (in module cgi): Functions<8>. (line 46) * test.support (module): test support — Utilities for the Python test suite. (line 6) * test.support.script_helper (module): test support script_helper — Utilities for the Python execution tests. (line 6) * TestCase (class in unittest): Test cases. (line 6) * TestFailed: test support — Utilities for the Python test suite. (line 16) * testfile() (in module doctest): Basic API. (line 12) * TESTFN (in module test.support): test support — Utilities for the Python test suite. (line 52) * TESTFN_ENCODING (in module test.support): test support — Utilities for the Python test suite. (line 62) * TESTFN_NONASCII (in module test.support): test support — Utilities for the Python test suite. (line 78) * TESTFN_UNDECODABLE (in module test.support): test support — Utilities for the Python test suite. (line 72) * TESTFN_UNENCODABLE (in module test.support): test support — Utilities for the Python test suite. (line 66) * TESTFN_UNICODE (in module test.support): test support — Utilities for the Python test suite. (line 58) * TestHandler (class in test.support): test support — Utilities for the Python test suite. (line 1108) * TestLoader (class in unittest): Loading and running tests. (line 6) * testMethodPrefix (unittest.TestLoader attribute): Loading and running tests. (line 178) * testmod() (in module doctest): Basic API. (line 90) * testNamePatterns (unittest.TestLoader attribute): Loading and running tests. (line 200) * TestResult (class in unittest): Loading and running tests. (line 217) * tests (in module imghdr): imghdr — Determine the type of an image. (line 75) * testsource() (in module doctest): Debugging. (line 106) * testsRun (unittest.TestResult attribute): Loading and running tests. (line 273) * TestSuite (class in unittest): Grouping tests. (line 6) * testzip() (zipfile.ZipFile method): ZipFile Objects. (line 232) * TEST_DATA_DIR (in module test.support): test support — Utilities for the Python test suite. (line 114) * TEST_HOME_DIR (in module test.support): test support — Utilities for the Python test suite. (line 110) * TEST_HTTP_URL (in module test.support): test support — Utilities for the Python test suite. (line 141) * TEST_SUPPORT_DIR (in module test.support): test support — Utilities for the Python test suite. (line 105) * Text (class in typing): Classes functions and decorators. (line 457) * text (in module msilib): Precomputed tables. (line 23) * text (traceback.TracebackException attribute): TracebackException Objects. (line 50) * text (xml.etree.ElementTree.Element attribute): Element Objects. (line 21) * text encoding: Glossary. (line 1204) * text file: Glossary. (line 1208) * text mode: Built-in Functions. (line 1217) * text() (in module cgitb): cgitb — Traceback manager for CGI scripts. (line 48) * text() (msilib.Dialog method): GUI classes. (line 56) * Textbox (class in curses.textpad): Textbox objects. (line 8) * TextCalendar (class in calendar): calendar — General calendar-related functions. (line 128) * textdomain() (in module gettext): GNU gettext API. (line 36) * textdomain() (in module locale): Access to message catalogs. (line 12) * TextFile (class in distutils.text_file): distutils text_file — The TextFile class. (line 10) * textinput() (in module turtle): Input methods. (line 6) * TextIO (class in typing): Classes functions and decorators. (line 471) * TextIOBase (class in io): Text I/O<2>. (line 6) * TextIOWrapper (class in io): Text I/O<2>. (line 99) * TextTestResult (class in unittest): Loading and running tests. (line 422) * TextTestRunner (class in unittest): Loading and running tests. (line 437) * textwrap (module): textwrap — Text wrapping and filling. (line 6) * TextWrapper (class in textwrap): textwrap — Text wrapping and filling. (line 129) * text_factory (sqlite3.Connection attribute): Connection Objects. (line 336) * theme_create() (tkinter.ttk.Style method): Ttk Styling. (line 191) * theme_names() (tkinter.ttk.Style method): Ttk Styling. (line 239) * theme_settings() (tkinter.ttk.Style method): Ttk Styling. (line 201) * theme_use() (tkinter.ttk.Style method): Ttk Styling. (line 243) * THOUSEP (in module locale): locale — Internationalization services. (line 236) * Thread (class in threading): Thread Objects. (line 57) * thread() (imaplib.IMAP4 method): IMAP4 Objects. (line 335) * ThreadedChildWatcher (class in asyncio): Process Watchers. (line 84) * threading (module): threading — Thread-based parallelism. (line 6) * ThreadingHTTPServer (class in http.server): http server — HTTP servers. (line 32) * ThreadingMixIn (class in socketserver): Server Creation Notes. (line 28) * ThreadingTCPServer (class in socketserver): Server Creation Notes. (line 62) * ThreadingUDPServer (class in socketserver): Server Creation Notes. (line 62) * threading_cleanup() (in module test.support): test support — Utilities for the Python test suite. (line 782) * threading_setup() (in module test.support): test support — Utilities for the Python test suite. (line 778) * ThreadPool (class in multiprocessing.pool): The multiprocessing dummy module. (line 16) * ThreadPoolExecutor (class in concurrent.futures): ThreadPoolExecutor. (line 39) * threads; POSIX: _thread — Low-level threading API. (line 16) * thread_info (in module sys): sys — System-specific parameters and functions. (line 1547) * thread_time() (in module time): Functions<2>. (line 477) * thread_time_ns() (in module time): Functions<2>. (line 491) * throw (2to3 fixer): Fixers. (line 302) * throw() (coroutine method): Coroutine Objects. (line 34) * throw() (generator method): Generator-iterator methods. (line 38) * ticket_lifetime_hint (ssl.SSLSession attribute): SSL session. (line 18) * tigetflag() (in module curses): Functions<3>. (line 470) * tigetnum() (in module curses): Functions<3>. (line 477) * tigetstr() (in module curses): Functions<3>. (line 484) * TILDE (in module token): token — Constants used with Python parse trees. (line 150) * tilt() (in module turtle): Appearance. (line 102) * tiltangle() (in module turtle): Appearance. (line 137) * time (class in datetime): time Objects. (line 10) * time (module): time — Time access and conversions. (line 6) * time (ssl.SSLSession attribute): SSL session. (line 14) * time() (asyncio.loop method): Scheduling delayed callbacks. (line 56) * time() (datetime.datetime method): datetime Objects. (line 395) * time() (in module time): Functions<2>. (line 454) * Time2Internaldate() (in module imaplib): imaplib — IMAP4 protocol client. (line 122) * timedelta (class in datetime): timedelta Objects. (line 9) * TimedRotatingFileHandler (class in logging.handlers): TimedRotatingFileHandler. (line 10) * timegm() (in module calendar): calendar — General calendar-related functions. (line 355) * timeit (module): timeit — Measure execution time of small code snippets. (line 6) * timeit command line option; -h: Command-Line Interface<4>. (line 44) * timeit command line option; –help: Command-Line Interface<4>. (line 44) * timeit command line option; -n N: Command-Line Interface<4>. (line 13) * timeit command line option; –number=N: Command-Line Interface<4>. (line 13) * timeit command line option; -p: Command-Line Interface<4>. (line 25) * timeit command line option; –process: Command-Line Interface<4>. (line 25) * timeit command line option; -r N: Command-Line Interface<4>. (line 17) * timeit command line option; –repeat=N: Command-Line Interface<4>. (line 17) * timeit command line option; -s S: Command-Line Interface<4>. (line 21) * timeit command line option; –setup=S: Command-Line Interface<4>. (line 21) * timeit command line option; -u: Command-Line Interface<4>. (line 33) * timeit command line option; –unit=U: Command-Line Interface<4>. (line 33) * timeit command line option; -v: Command-Line Interface<4>. (line 40) * timeit command line option; –verbose: Command-Line Interface<4>. (line 40) * timeit() (in module timeit): Python Interface. (line 8) * timeit() (timeit.Timer method): Python Interface. (line 69) * timeout: Exceptions<11>. (line 40) * timeout (socketserver.BaseServer attribute): Server Objects<2>. (line 114) * timeout (ssl.SSLSession attribute): SSL session. (line 16) * timeout (subprocess.TimeoutExpired attribute): Using the subprocess Module. (line 168) * timeout() (curses.window method): Window Objects. (line 558) * TimeoutError: OS exceptions. (line 103) * TimeoutError <1>: Process and exceptions. (line 220) * TimeoutError <2>: Exception classes. (line 10) * TimeoutError <3>: Exceptions<9>. (line 10) * TimeoutExpired: Using the subprocess Module. (line 159) * TIMEOUT_MAX (in module threading): threading — Thread-based parallelism. (line 161) * TIMEOUT_MAX (in module _thread): _thread — Low-level threading API. (line 116) * Timer (class in threading): Timer Objects. (line 25) * Timer (class in timeit): Python Interface. (line 39) * TimerHandle (class in asyncio): Callback Handles. (line 22) * times() (in module os): Process Management. (line 680) * TIMESTAMP (py_compile.PycInvalidationMode attribute): py_compile — Compile Python source files. (line 101) * timestamp() (datetime.datetime method): datetime Objects. (line 546) * timetuple() (datetime.date method): date Objects. (line 179) * timetuple() (datetime.datetime method): datetime Objects. (line 501) * timetz() (datetime.datetime method): datetime Objects. (line 404) * timezone (class in datetime): timezone Objects. (line 14) * timezone (in module time): Timezone Constants. (line 17) * time_ns() (in module time): Functions<2>. (line 498) * title() (bytearray method): Bytes and Bytearray Operations. (line 621) * title() (bytes method): Bytes and Bytearray Operations. (line 621) * title() (in module turtle): Methods specific to Screen not inherited from TurtleScreen. (line 49) * title() (str method): String Methods<2>. (line 544) * Tix: tkinter tix — Extension widgets for Tk. (line 8) * tixCommand (class in tkinter.tix): Tix Commands. (line 6) * tix_addbitmapdir() (tkinter.tix.tixCommand method): Tix Commands. (line 47) * tix_cget() (tkinter.tix.tixCommand method): Tix Commands. (line 32) * tix_configure() (tkinter.tix.tixCommand method): Tix Commands. (line 20) * tix_filedialog() (tkinter.tix.tixCommand method): Tix Commands. (line 57) * tix_getbitmap() (tkinter.tix.tixCommand method): Tix Commands. (line 37) * tix_getimage() (tkinter.tix.tixCommand method): Tix Commands. (line 68) * tix_option_get() (tkinter.tix.tixCommand method): Tix Commands. (line 82) * tix_resetoptions() (tkinter.tix.tixCommand method): Tix Commands. (line 86) * Tk: Graphical User Interfaces with Tk. (line 6) * Tk (class in tkinter): Tkinter Modules. (line 25) * Tk (class in tkinter.tix): Using Tix. (line 6) * Tk Option Data Types: Tk Option Data Types. (line 6) * Tkinter: Graphical User Interfaces with Tk. (line 6) * tkinter (module): tkinter — Python interface to Tcl/Tk. (line 6) * tkinter.scrolledtext (module): tkinter scrolledtext — Scrolled Text Widget. (line 6) * tkinter.tix (module): tkinter tix — Extension widgets for Tk. (line 6) * tkinter.ttk (module): tkinter ttk — Tk themed widgets. (line 6) * TK_LIBRARY: How do I freeze Tkinter applications?. (line 11) * TList (class in tkinter.tix): Tabular ListBox. (line 6) * TLS: ssl — TLS/SSL wrapper for socket objects. (line 8) * TLSv1 (ssl.TLSVersion attribute): Constants<9>. (line 535) * TLSv1_1 (ssl.TLSVersion attribute): Constants<9>. (line 537) * TLSv1_2 (ssl.TLSVersion attribute): Constants<9>. (line 539) * TLSv1_3 (ssl.TLSVersion attribute): Constants<9>. (line 541) * TLSVersion (class in ssl): Constants<9>. (line 517) * TMP: tempfile — Generate temporary files and directories. (line 241) * TMPDIR: tempfile — Generate temporary files and directories. (line 237) * ToASCII() (in module encodings.idna): encodings idna — Internationalized Domain Names in Applications. (line 52) * tobuf() (tarfile.TarInfo method): TarInfo Objects. (line 31) * tobytes() (array.array method): array — Efficient arrays of numeric values. (line 218) * tobytes() (memoryview method): Memory Views. (line 159) * today() (datetime.date class method): date Objects. (line 29) * today() (datetime.datetime class method): datetime Objects. (line 47) * tofile() (array.array method): array — Efficient arrays of numeric values. (line 227) * token: Lexical analysis. (line 6) * token (module): token — Constants used with Python parse trees. (line 6) * token (shlex.shlex attribute): shlex Objects. (line 173) * TokenError: Tokenizing Input. (line 107) * tokenize (module): tokenize — Tokenizer for Python source. (line 6) * tokenize command line option; -e: Command-Line Usage<2>. (line 19) * tokenize command line option; –exact: Command-Line Usage<2>. (line 19) * tokenize command line option; -h: Command-Line Usage<2>. (line 15) * tokenize command line option; –help: Command-Line Usage<2>. (line 15) * tokenize() (in module tokenize): Tokenizing Input. (line 8) * token_bytes() (in module secrets): Generating tokens. (line 10) * token_hex() (in module secrets): Generating tokens. (line 19) * token_urlsafe() (in module secrets): Generating tokens. (line 28) * tok_name (in module token): token — Constants used with Python parse trees. (line 20) * tolist() (array.array method): array — Efficient arrays of numeric values. (line 232) * tolist() (memoryview method): Memory Views. (line 200) * tolist() (parser.ST method): ST Objects. (line 29) * tomono() (in module audioop): audioop — Manipulate raw audio data. (line 200) * toordinal() (datetime.date method): date Objects. (line 194) * toordinal() (datetime.datetime method): datetime Objects. (line 541) * top() (curses.panel.Panel method): Panel Objects. (line 53) * top() (poplib.POP3 method): POP3 Objects. (line 86) * toprettyxml() (xml.dom.minidom.Node method): DOM Objects. (line 58) * top_panel() (in module curses.panel): Functions<4>. (line 19) * toreadonly() (memoryview method): Memory Views. (line 216) * tostereo() (in module audioop): audioop — Manipulate raw audio data. (line 206) * tostring() (array.array method): array — Efficient arrays of numeric values. (line 236) * tostring() (in module xml.etree.ElementTree): Functions<6>. (line 205) * tostringlist() (in module xml.etree.ElementTree): Functions<6>. (line 227) * total_changes (sqlite3.Connection attribute): Connection Objects. (line 379) * total_ordering() (in module functools): functools — Higher-order functions and operations on callable objects. (line 172) * total_seconds() (datetime.timedelta method): timedelta Objects. (line 245) * totuple() (parser.ST method): ST Objects. (line 33) * touch() (pathlib.Path method): Methods<2>. (line 409) * touchline() (curses.window method): Window Objects. (line 568) * touchwin() (curses.window method): Window Objects. (line 575) * tounicode() (array.array method): array — Efficient arrays of numeric values. (line 242) * ToUnicode() (in module encodings.idna): encodings idna — Internationalized Domain Names in Applications. (line 57) * towards() (in module turtle): Tell Turtle’s state. (line 15) * toxml() (xml.dom.minidom.Node method): DOM Objects. (line 43) * to_bytes() (int method): Additional Methods on Integer Types. (line 35) * to_eng_string() (decimal.Context method): Context objects. (line 506) * to_eng_string() (decimal.Decimal method): Decimal objects. (line 558) * to_integral() (decimal.Decimal method): Decimal objects. (line 571) * to_integral_exact() (decimal.Context method): Context objects. (line 516) * to_integral_exact() (decimal.Decimal method): Decimal objects. (line 577) * to_integral_value() (decimal.Decimal method): Decimal objects. (line 585) * to_sci_string() (decimal.Context method): Context objects. (line 520) * tparm() (in module curses): Functions<3>. (line 491) * Trace (class in trace): Programmatic Interface. (line 6) * Trace (class in tracemalloc): Trace. (line 6) * trace (module): trace — Trace or track Python statement execution. (line 6) * trace command line option; -c: Main options. (line 12) * trace command line option; -C: Modifiers. (line 11) * trace command line option; –count: Main options. (line 12) * trace command line option; –coverdir=: Modifiers. (line 11) * trace command line option; -f: Modifiers. (line 6) * trace command line option; –file=: Modifiers. (line 6) * trace command line option; -g: Modifiers. (line 33) * trace command line option; –help: Command-Line Usage. (line 15) * trace command line option; –ignore-dir=: Filters. (line 14) * trace command line option; –ignore-module=: Filters. (line 8) * trace command line option; -l: Main options. (line 23) * trace command line option; –listfuncs: Main options. (line 23) * trace command line option; -m: Modifiers. (line 17) * trace command line option; –missing: Modifiers. (line 17) * trace command line option; –no-report: Modifiers. (line 27) * trace command line option; -r: Main options. (line 27) * trace command line option; -R: Modifiers. (line 27) * trace command line option; –report: Main options. (line 27) * trace command line option; -s: Modifiers. (line 22) * trace command line option; –summary: Modifiers. (line 22) * trace command line option; -t: Main options. (line 19) * trace command line option; -T: Main options. (line 33) * trace command line option; –timing: Modifiers. (line 33) * trace command line option; –trace: Main options. (line 19) * trace command line option; –trackcalls: Main options. (line 33) * trace command line option; –version: Command-Line Usage. (line 19) * trace function: threading — Thread-based parallelism. (line 125) * trace function <1>: sys — System-specific parameters and functions. (line 745) * trace function <2>: sys — System-specific parameters and functions. (line 1310) * trace() (in module inspect): The interpreter stack. (line 94) * Traceback (class in tracemalloc): Traceback. (line 6) * traceback (module): traceback — Print or retrieve a stack traceback. (line 6) * traceback (tracemalloc.Statistic attribute): Statistic. (line 23) * traceback (tracemalloc.StatisticDiff attribute): StatisticDiff. (line 38) * traceback (tracemalloc.Trace attribute): Trace. (line 27) * TracebackException (class in traceback): TracebackException Objects. (line 11) * tracebacklimit (in module sys): sys — System-specific parameters and functions. (line 1581) * tracebacks; in CGI scripts: cgitb — Traceback manager for CGI scripts. (line 8) * TracebackType (class in types): Standard Interpreter Types. (line 182) * traceback_limit (tracemalloc.Snapshot attribute): Snapshot. (line 83) * traceback_limit (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 219) * tracemalloc (module): tracemalloc — Trace memory allocations. (line 6) * tracer() (in module turtle): Animation control. (line 23) * traces (tracemalloc.Snapshot attribute): Snapshot. (line 89) * trace_dispatch() (bdb.Bdb method): bdb — Debugger framework. (line 111) * trailing; comma: Expression lists. (line 24) * transfercmd() (ftplib.FTP method): FTP Objects. (line 135) * TransientResource (class in test.support): test support — Utilities for the Python test suite. (line 1016) * transient_internet() (in module test.support): test support — Utilities for the Python test suite. (line 463) * translate() (bytearray method): Bytes and Bytearray Operations. (line 210) * translate() (bytes method): Bytes and Bytearray Operations. (line 210) * translate() (in module fnmatch): fnmatch — Unix filename pattern matching. (line 71) * translate() (str method): String Methods<2>. (line 575) * translation() (in module gettext): Class-based API. (line 44) * transport (asyncio.StreamWriter attribute): StreamWriter. (line 57) * Transport (class in asyncio): Transports Hierarchy. (line 29) * Transport Layer Security: ssl — TLS/SSL wrapper for socket objects. (line 8) * traverseproc (C type): Supporting Cyclic Garbage Collection. (line 102) * Tree (class in tkinter.tix): Hierarchical ListBox. (line 20) * TreeBuilder (class in xml.etree.ElementTree): TreeBuilder Objects. (line 6) * Treeview (class in tkinter.ttk): ttk Treeview. (line 6) * triangular() (in module random): Real-valued distributions. (line 25) * triple-quoted string: String and Bytes literals. (line 36) * triple-quoted string <1>: Glossary. (line 1220) * True: The standard type hierarchy. (line 93) * true: Truth Value Testing. (line 10) * True <1>: Truth Value Testing. (line 23) * True <2>: Boolean Values. (line 15) * True (built-in variable): Built-in Constants. (line 13) * truediv() (in module operator): operator — Standard operators as functions. (line 158) * trunc() (in module math): Numeric Types — int float complex. (line 104) * trunc() (in module math) <1>: Number-theoretic and representation functions. (line 227) * truncate() (in module os): Files and Directories. (line 1415) * truncate() (io.IOBase method): I/O Base Classes. (line 139) * truth() (in module operator): operator — Standard operators as functions. (line 57) * truth; value: Truth Value Testing. (line 6) * ttk: tkinter ttk — Tk themed widgets. (line 8) * tty (module): tty — Terminal control functions. (line 6) * tty; I/O control: termios — POSIX style tty control. (line 6) * ttyname() (in module os): File Descriptor Operations. (line 668) * tuple (built-in class): Tuples. (line 12) * Tuple (in module typing): Classes functions and decorators. (line 849) * tuple2st() (in module parser): Creating ST Objects. (line 51) * tuple_params (2to3 fixer): Fixers. (line 306) * Turtle (class in turtle): Public classes. (line 16) * turtle (module): turtle — Turtle graphics. (line 6) * turtledemo (module): turtledemo — Demo scripts. (line 6) * turtles() (in module turtle): Settings and special methods. (line 96) * TurtleScreen (class in turtle): Public classes. (line 22) * turtlesize() (in module turtle): Appearance. (line 52) * type: The standard type hierarchy. (line 6) * type <1>: Glossary. (line 1230) * type (built-in class): Built-in Functions. (line 1662) * Type (class in typing): Classes functions and decorators. (line 105) * type (optparse.Option attribute): Option attributes. (line 19) * type (socket.socket attribute): Socket Objects. (line 599) * type (tarfile.TarInfo attribute): TarInfo Objects. (line 59) * type (urllib.request.Request attribute): Request Objects. (line 21) * type alias: Glossary. (line 1237) * type hint: Glossary. (line 1263) * type of an object: Objects values and types. (line 11) * type; hierarchy: The standard type hierarchy. (line 6) * typeahead() (in module curses): Functions<3>. (line 499) * typecode (array.array attribute): array — Efficient arrays of numeric values. (line 104) * typecodes (in module array): array — Efficient arrays of numeric values. (line 91) * TypedDict (class in typing): Classes functions and decorators. (line 550) * TYPED_ACTIONS (optparse.Option attribute): Adding new actions. (line 39) * typed_subpart_iterator() (in module email.iterators): email iterators Iterators. (line 26) * TypeError: Concrete exceptions. (line 309) * types (2to3 fixer): Fixers. (line 311) * types (module): types — Dynamic type creation and names for built-in types. (line 6) * TYPES (optparse.Option attribute): Adding new types. (line 11) * types, internal: The standard type hierarchy. (line 645) * types_map (in module mimetypes): mimetypes — Map filenames to MIME types. (line 140) * types_map (mimetypes.MimeTypes attribute): MimeTypes Objects. (line 39) * types_map_inv (mimetypes.MimeTypes attribute): MimeTypes Objects. (line 47) * TypeVar (class in typing): Classes functions and decorators. (line 8) * TYPE_CHECKER (optparse.Option attribute): Adding new types. (line 16) * TYPE_CHECKING (in module typing): Classes functions and decorators. (line 966) * type_check_only() (in module typing): Classes functions and decorators. (line 734) * TYPE_COMMENT (in module token): token — Constants used with Python parse trees. (line 250) * TYPE_IGNORE (in module token): token — Constants used with Python parse trees. (line 248) * typing (module): typing — Support for type hints. (line 6) * TZ: Functions<2>. (line 508) * TZ <1>: Functions<2>. (line 509) * TZ <2>: Functions<2>. (line 517) * TZ <3>: Functions<2>. (line 522) * TZ <4>: Functions<2>. (line 524) * TZ <5>: Functions<2>. (line 584) * tzinfo (class in datetime): tzinfo Objects. (line 6) * tzinfo (datetime.datetime attribute): datetime Objects. (line 293) * tzinfo (datetime.time attribute): time Objects. (line 66) * tzname (in module time): Timezone Constants. (line 23) * tzname() (datetime.datetime method): datetime Objects. (line 495) * tzname() (datetime.time method): time Objects. (line 243) * tzname() (datetime.timezone method): timezone Objects. (line 42) * tzname() (datetime.tzinfo method): tzinfo Objects. (line 123) * tzset() (in module time): Functions<2>. (line 505) * T_FMT (in module locale): locale — Internationalization services. (line 201) * T_FMT_AMPM (in module locale): locale — Internationalization services. (line 207) * u"; string literal: Literals. (line 8) * u’; string literal: Literals. (line 8) * u-LAW: audioop — Manipulate raw audio data. (line 17) * u-LAW <1>: aifc — Read and write AIFF and AIFC files. (line 160) * u-LAW <2>: sndhdr — Determine type of sound file. (line 8) * ucd_3_2_0 (in module unicodedata): unicodedata — Unicode Database. (line 131) * udata (select.kevent attribute): Kevent Objects. (line 179) * UDPServer (class in socketserver): socketserver — A framework for network servers. (line 25) * UF_APPEND (in module stat): stat — Interpreting stat results. (line 346) * UF_COMPRESSED (in module stat): stat — Interpreting stat results. (line 358) * UF_HIDDEN (in module stat): stat — Interpreting stat results. (line 362) * UF_IMMUTABLE (in module stat): stat — Interpreting stat results. (line 342) * UF_NODUMP (in module stat): stat — Interpreting stat results. (line 338) * UF_NOUNLINK (in module stat): stat — Interpreting stat results. (line 354) * UF_OPAQUE (in module stat): stat — Interpreting stat results. (line 350) * UID (class in plistlib): plistlib — Generate and parse Mac OS X plist files. (line 181) * uid (tarfile.TarInfo attribute): TarInfo Objects. (line 72) * uid() (imaplib.IMAP4 method): IMAP4 Objects. (line 358) * uidl() (poplib.POP3 method): POP3 Objects. (line 98) * ulaw2lin() (in module audioop): audioop — Manipulate raw audio data. (line 213) * ULONG_MAX: Integer Objects. (line 199) * umask() (in module os): Process Parameters. (line 465) * unalias (pdb command): Debugger Commands. (line 307) * uname (tarfile.TarInfo attribute): TarInfo Objects. (line 80) * uname() (in module os): Process Parameters. (line 469) * uname() (in module platform): Cross Platform. (line 137) * unary; arithmetic; operation: Unary arithmetic and bitwise operations. (line 6) * unary; bitwise; operation: Unary arithmetic and bitwise operations. (line 6) * unaryfunc (C type): Slot Type typedefs. (line 109) * UNARY_INVERT (opcode): Python Bytecode Instructions. (line 109) * UNARY_NEGATIVE (opcode): Python Bytecode Instructions. (line 101) * UNARY_NOT (opcode): Python Bytecode Instructions. (line 105) * UNARY_POSITIVE (opcode): Python Bytecode Instructions. (line 97) * unbinding; name: The del statement<2>. (line 15) * UnboundLocalError: Resolution of names. (line 16) * UnboundLocalError <1>: Concrete exceptions. (line 327) * unbuffered I/O: Built-in Functions. (line 1217) * UNC paths; and os.makedirs(): Files and Directories. (line 454) * UNCHECKED_HASH (py_compile.PycInvalidationMode attribute): py_compile — Compile Python source files. (line 114) * unconsumed_tail (zlib.Decompress attribute): zlib — Compression compatible with gzip. (line 239) * unctrl() (in module curses): Functions<3>. (line 511) * unctrl() (in module curses.ascii): curses ascii — Utilities for ASCII characters. (line 226) * undefine_macro() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 170) * Underflow (class in decimal): Signals. (line 93) * undisplay (pdb command): Debugger Commands. (line 267) * undo() (in module turtle): Turtle motion. (line 291) * undobufferentries() (in module turtle): Special Turtle methods. (line 74) * undoc_header (cmd.Cmd attribute): Cmd Objects. (line 158) * unescape() (in module html): html — HyperText Markup Language support. (line 23) * unescape() (in module xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 24) * UnexpectedException: Debugging. (line 208) * unexpectedSuccesses (unittest.TestResult attribute): Loading and running tests. (line 263) * unfreeze() (in module gc): gc — Garbage Collector interface. (line 194) * ungetch() (in module curses): Functions<3>. (line 518) * ungetch() (in module msvcrt): Console I/O. (line 44) * ungetmouse() (in module curses): Functions<3>. (line 540) * ungetwch() (in module msvcrt): Console I/O. (line 50) * unget_wch() (in module curses): Functions<3>. (line 531) * unhexlify() (in module binascii): binascii — Convert between binary and ASCII. (line 161) * Unicode: The standard type hierarchy. (line 156) * Unicode <1>: unicodedata — Unicode Database. (line 6) * Unicode <2>: codecs — Codec registry and base classes. (line 8) * unicode (2to3 fixer): Fixers. (line 316) * Unicode Consortium: String and Bytes literals. (line 36) * Unicode; database: unicodedata — Unicode Database. (line 6) * unicodedata (module): unicodedata — Unicode Database. (line 6) * UnicodeDecodeError: Concrete exceptions. (line 367) * UnicodeEncodeError: Concrete exceptions. (line 362) * UnicodeError: Concrete exceptions. (line 333) * UnicodeTranslateError: Concrete exceptions. (line 372) * UnicodeWarning: Warnings. (line 50) * unidata_version (in module unicodedata): unicodedata — Unicode Database. (line 127) * unified_diff() (in module difflib): difflib — Helpers for computing deltas. (line 295) * uniform() (in module random): Real-valued distributions. (line 16) * UnimplementedFileMode: http client — HTTP protocol client. (line 150) * Union (class in ctypes): Structured data types. (line 6) * Union (in module typing): Classes functions and decorators. (line 795) * union() (frozenset method): Set Types — set frozenset. (line 96) * unique() (in module enum): Ensuring unique enumeration values. (line 10) * unittest (module): unittest — Unit testing framework. (line 6) * unittest command line option; -b: Command-line options<3>. (line 8) * unittest command line option; –buffer: Command-line options<3>. (line 8) * unittest command line option; -c: Command-line options<3>. (line 15) * unittest command line option; –catch: Command-line options<3>. (line 15) * unittest command line option; -f: Command-line options<3>. (line 24) * unittest command line option; –failfast: Command-line options<3>. (line 24) * unittest command line option; -k: Command-line options<3>. (line 28) * unittest command line option; –locals: Command-line options<3>. (line 45) * unittest-discover command line option; -p: Test Discovery. (line 35) * unittest-discover command line option; –pattern pattern: Test Discovery. (line 35) * unittest-discover command line option; -s: Test Discovery. (line 31) * unittest-discover command line option; –start-directory directory: Test Discovery. (line 31) * unittest-discover command line option; -t: Test Discovery. (line 39) * unittest-discover command line option; –top-level-directory directory: Test Discovery. (line 39) * unittest-discover command line option; -v: Test Discovery. (line 27) * unittest-discover command line option; –verbose: Test Discovery. (line 27) * unittest.mock (module): unittest mock — mock object library. (line 6) * universal newlines: Glossary. (line 1280) * universal newlines; bytearray.splitlines method: Bytes and Bytearray Operations. (line 572) * universal newlines; bytes.splitlines method: Bytes and Bytearray Operations. (line 572) * universal newlines; csv.reader function: Module Contents<3>. (line 8) * universal newlines; importlib.abc.InspectLoader.get_source method: importlib abc – Abstract base classes related to import. (line 398) * universal newlines; io.IncrementalNewlineDecoder class: Text I/O<2>. (line 234) * universal newlines; io.TextIOWrapper class: Text I/O<2>. (line 123) * universal newlines; open() built-in function: Built-in Functions. (line 1155) * universal newlines; str.splitlines method: String Methods<2>. (line 434) * universal newlines; subprocess module: Frequently Used Arguments. (line 33) * universal newlines; What’s new: PEP 3116 New I/O Library. (line 42) * universal newlines; What’s new <1>: New Improved and Removed Modules. (line 138) * universal newlines; What’s new <2>: PEP 324 New subprocess Module. (line 36) * universal newlines; What’s new <3>: PEP 277 Unicode file name support for Windows NT. (line 36) * UNIX: Complete Python programs. (line 25) * UNIX; file control: fcntl — The fcntl and ioctl system calls. (line 6) * UNIX; I/O control: fcntl — The fcntl and ioctl system calls. (line 6) * UnixDatagramServer (class in socketserver): socketserver — A framework for network servers. (line 32) * UnixStreamServer (class in socketserver): socketserver — A framework for network servers. (line 32) * unix_dialect (class in csv): Module Contents<3>. (line 195) * unix_shell (in module test.support): test support — Utilities for the Python test suite. (line 44) * unknown (uuid.SafeUUID attribute): uuid — UUID objects according to RFC 4122. (line 40) * UnknownHandler (class in urllib.request): urllib request — Extensible library for opening URLs. (line 435) * UnknownProtocol: http client — HTTP protocol client. (line 142) * UnknownTransferEncoding: http client — HTTP protocol client. (line 146) * unknown_decl() (html.parser.HTMLParser method): HTMLParser Methods. (line 137) * unknown_open() (urllib.request.BaseHandler method): BaseHandler Objects. (line 55) * unknown_open() (urllib.request.UnknownHandler method): UnknownHandler Objects. (line 6) * unlink() (in module os): Files and Directories. (line 1433) * unlink() (in module test.support): test support — Utilities for the Python test suite. (line 171) * unlink() (multiprocessing.shared_memory.SharedMemory method): multiprocessing shared_memory — Provides shared memory for direct access across processes. (line 73) * unlink() (pathlib.Path method): Methods<2>. (line 418) * unlink() (xml.dom.minidom.Node method): DOM Objects. (line 10) * unload() (in module test.support): test support — Utilities for the Python test suite. (line 167) * unlock() (mailbox.Babyl method): Babyl. (line 59) * unlock() (mailbox.Mailbox method): Mailbox objects. (line 258) * unlock() (mailbox.Maildir method): Maildir. (line 107) * unlock() (mailbox.mbox method): mbox. (line 39) * unlock() (mailbox.MH method): MH. (line 84) * unlock() (mailbox.MMDF method): MMDF. (line 35) * unpack() (in module struct): Functions and Exceptions. (line 26) * unpack() (struct.Struct method): Classes<2>. (line 35) * Unpacker (class in xdrlib): xdrlib — Encode and decode XDR data. (line 24) * unpacking; dictionary: Dictionary displays. (line 23) * unpacking; in function calls: Calls. (line 74) * unpack_archive() (in module shutil): Archiving operations. (line 105) * unpack_array() (xdrlib.Unpacker method): Unpacker Objects. (line 91) * unpack_bytes() (xdrlib.Unpacker method): Unpacker Objects. (line 70) * unpack_double() (xdrlib.Unpacker method): Unpacker Objects. (line 40) * UNPACK_EX (opcode): Python Bytecode Instructions. (line 499) * unpack_farray() (xdrlib.Unpacker method): Unpacker Objects. (line 85) * unpack_float() (xdrlib.Unpacker method): Unpacker Objects. (line 36) * unpack_fopaque() (xdrlib.Unpacker method): Unpacker Objects. (line 54) * unpack_from() (in module struct): Functions and Exceptions. (line 34) * unpack_from() (struct.Struct method): Classes<2>. (line 41) * unpack_fstring() (xdrlib.Unpacker method): Unpacker Objects. (line 48) * unpack_list() (xdrlib.Unpacker method): Unpacker Objects. (line 77) * unpack_opaque() (xdrlib.Unpacker method): Unpacker Objects. (line 65) * UNPACK_SEQUENCE (opcode): Python Bytecode Instructions. (line 494) * unpack_string() (xdrlib.Unpacker method): Unpacker Objects. (line 59) * unparsedEntityDecl() (xml.sax.handler.DTDHandler method): DTDHandler Objects. (line 12) * UnparsedEntityDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 249) * Unpickler (class in pickle): Module Interface. (line 226) * UnpicklingError: Module Interface. (line 108) * unquote() (in module email.utils): email utils Miscellaneous utilities. (line 52) * unquote() (in module urllib.parse): URL Quoting. (line 60) * unquote_plus() (in module urllib.parse): URL Quoting. (line 76) * unquote_to_bytes() (in module urllib.parse): URL Quoting. (line 86) * unraisablehook() (in module sys): sys — System-specific parameters and functions. (line 1589) * unreachable object: Objects values and types. (line 37) * unreadline() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 130) * unrecognized escape sequence: String and Bytes literals. (line 156) * unregister() (in module atexit): atexit — Exit handlers. (line 43) * unregister() (in module faulthandler): Dumping the traceback on a user signal. (line 23) * unregister() (select.devpoll method): /dev/poll Polling Objects. (line 55) * unregister() (select.epoll method): Edge and Level Trigger Polling epoll Objects. (line 89) * unregister() (select.poll method): Polling Objects. (line 67) * unregister() (selectors.BaseSelector method): Classes<3>. (line 80) * unregister_archive_format() (in module shutil): Archiving operations. (line 100) * unregister_dialect() (in module csv): Module Contents<3>. (line 79) * unregister_unpack_format() (in module shutil): Archiving operations. (line 143) * unsafe (uuid.SafeUUID attribute): uuid — UUID objects according to RFC 4122. (line 36) * unset() (test.support.EnvironmentVarGuard method): test support — Utilities for the Python test suite. (line 1041) * unsetenv() (in module os): Process Parameters. (line 499) * UnstructuredHeader (class in email.headerregistry): email headerregistry Custom Header Objects. (line 115) * unsubscribe() (imaplib.IMAP4 method): IMAP4 Objects. (line 365) * UnsupportedOperation: High-level Module Interface. (line 43) * until (pdb command): Debugger Commands. (line 177) * untokenize() (in module tokenize): Tokenizing Input. (line 57) * untouchwin() (curses.window method): Window Objects. (line 580) * unused_data (bz2.BZ2Decompressor attribute): Incremental de compression. (line 78) * unused_data (lzma.LZMADecompressor attribute): Compressing and decompressing data in memory. (line 169) * unused_data (zlib.Decompress attribute): zlib — Compression compatible with gzip. (line 231) * unverifiable (urllib.request.Request attribute): Request Objects. (line 47) * unwrap() (in module inspect): Classes and functions<2>. (line 186) * unwrap() (in module urllib.parse): URL Parsing. (line 370) * unwrap() (ssl.SSLSocket method): SSL Sockets. (line 272) * up (pdb command): Debugger Commands. (line 66) * up() (in module turtle): Drawing state. (line 12) * update() (collections.Counter method): Counter objects. (line 111) * update() (dict method): Mapping Types — dict. (line 211) * update() (frozenset method): Set Types — set frozenset. (line 169) * update() (hashlib.hash method): Hash algorithms. (line 117) * update() (hmac.HMAC method): hmac — Keyed-Hashing for Message Authentication. (line 47) * update() (http.cookies.Morsel method): Morsel Objects. (line 94) * update() (in module turtle): Animation control. (line 46) * update() (mailbox.Mailbox method): Mailbox objects. (line 227) * update() (mailbox.Maildir method): Maildir. (line 91) * update() (trace.CoverageResults method): Programmatic Interface. (line 52) * update_authenticated() (urllib.request.HTTPPasswordMgrWithPriorAuth method): HTTPPasswordMgrWithPriorAuth Objects. (line 24) * update_lines_cols() (in module curses): Functions<3>. (line 524) * update_panels() (in module curses.panel): Functions<4>. (line 23) * update_visible() (mailbox.BabylMessage method): BabylMessage. (line 76) * update_wrapper() (in module functools): functools — Higher-order functions and operations on callable objects. (line 485) * upper() (bytearray method): Bytes and Bytearray Operations. (line 664) * upper() (bytes method): Bytes and Bytearray Operations. (line 664) * upper() (str method): String Methods<2>. (line 593) * urandom() (in module os): Random numbers<2>. (line 29) * URL: cgi — Common Gateway Interface support. (line 8) * URL <1>: urllib parse — Parse URLs into components. (line 8) * URL <2>: urllib robotparser — Parser for robots txt. (line 8) * URL <3>: http server — HTTP servers. (line 8) * url (xmlrpc.client.ProtocolError attribute): ProtocolError Objects. (line 13) * url2pathname() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 154) * URL; parsing: urllib parse — Parse URLs into components. (line 8) * urlcleanup() (in module urllib.request): Legacy interface. (line 62) * urldefrag() (in module urllib.parse): URL Parsing. (line 344) * urlencode() (in module urllib.parse): URL Quoting. (line 98) * URLError: urllib error — Exception classes raised by urllib request. (line 17) * urljoin() (in module urllib.parse): URL Parsing. (line 314) * urllib (2to3 fixer): Fixers. (line 320) * urllib (module): urllib — URL handling modules. (line 6) * urllib.error (module): urllib error — Exception classes raised by urllib request. (line 6) * urllib.parse (module): urllib parse — Parse URLs into components. (line 6) * urllib.request (module): urllib request — Extensible library for opening URLs. (line 6) * urllib.response (module): urllib response — Response classes used by urllib. (line 6) * urllib.robotparser (module): urllib robotparser — Parser for robots txt. (line 6) * urlopen() (in module urllib.request): urllib request — Extensible library for opening URLs. (line 22) * URLopener (class in urllib.request): Legacy interface. (line 67) * urlparse() (in module urllib.parse): URL Parsing. (line 9) * urlretrieve() (in module urllib.request): Legacy interface. (line 10) * urlsafe_b64decode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 91) * urlsafe_b64encode() (in module base64): base64 — Base16 Base32 Base64 Base85 Data Encodings. (line 84) * urlsplit() (in module urllib.parse): URL Parsing. (line 238) * urlunparse() (in module urllib.parse): URL Parsing. (line 230) * urlunsplit() (in module urllib.parse): URL Parsing. (line 305) * urn (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 135) * UseForeignDTD() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 63) * USER: getpass — Portable password input. (line 38) * user() (poplib.POP3 method): POP3 Objects. (line 31) * user-defined; function: The standard type hierarchy. (line 297) * user-defined; function; call: Calls. (line 123) * user-defined; method: The standard type hierarchy. (line 388) * user; effective id: Process Parameters. (line 173) * user; id: Process Parameters. (line 302) * user; id, setting: Process Parameters. (line 448) * UserDict (class in collections): UserDict objects. (line 12) * UserList (class in collections): UserList objects. (line 16) * USERNAME: Process Parameters. (line 221) * USERNAME <1>: getpass — Portable password input. (line 39) * username (email.headerregistry.Address attribute): email headerregistry Custom Header Objects. (line 432) * USERPROFILE: os path. (line 14) * USERPROFILE <1>: Changes in the Python API. (line 115) * USERPROFILE <2>: os path — Common pathname manipulations. (line 146) * USERPROFILE <3>: Location and names of config files. (line 67) * userptr() (curses.panel.Panel method): Panel Objects. (line 57) * UserString (class in collections): UserString objects. (line 12) * UserWarning: Warnings. (line 13) * USER_BASE: New and Improved Modules. (line 469) * USER_BASE (in module site): Module contents<3>. (line 30) * user_call() (bdb.Bdb method): bdb — Debugger framework. (line 212) * user_exception() (bdb.Bdb method): bdb — Debugger framework. (line 229) * user_line() (bdb.Bdb method): bdb — Debugger framework. (line 218) * user_return() (bdb.Bdb method): bdb — Debugger framework. (line 224) * USER_SITE (in module site): Module contents<3>. (line 19) * use_default_colors() (in module curses): Functions<3>. (line 555) * use_env() (in module curses): Functions<3>. (line 545) * use_rawinput (cmd.Cmd attribute): Cmd Objects. (line 169) * USTAR_FORMAT (in module tarfile): tarfile — Read and write tar archive files. (line 222) * UTC: time — Time access and conversions. (line 40) * utc (datetime.timezone attribute): timezone Objects. (line 68) * utcfromtimestamp() (datetime.datetime class method): datetime Objects. (line 124) * utcnow() (datetime.datetime class method): datetime Objects. (line 77) * utcoffset() (datetime.datetime method): datetime Objects. (line 475) * utcoffset() (datetime.time method): time Objects. (line 223) * utcoffset() (datetime.timezone method): timezone Objects. (line 30) * utcoffset() (datetime.tzinfo method): tzinfo Objects. (line 38) * utctimetuple() (datetime.datetime method): datetime Objects. (line 520) * utf8 (email.policy.EmailPolicy attribute): email policy Policy Objects. (line 363) * utf8() (poplib.POP3 method): POP3 Objects. (line 105) * utf8_enabled (imaplib.IMAP4 attribute): IMAP4 Objects. (line 387) * utime() (in module os): Files and Directories. (line 1447) * uu (module): uu — Encode and decode uuencode files. (line 6) * UUID (class in uuid): uuid — UUID objects according to RFC 4122. (line 45) * uuid (module): uuid — UUID objects according to RFC 4122. (line 6) * uuid1: uuid — UUID objects according to RFC 4122. (line 186) * uuid1() (in module uuid): uuid — UUID objects according to RFC 4122. (line 178) * uuid3: uuid — UUID objects according to RFC 4122. (line 191) * uuid3() (in module uuid): uuid — UUID objects according to RFC 4122. (line 186) * uuid4: uuid — UUID objects according to RFC 4122. (line 195) * uuid4() (in module uuid): uuid — UUID objects according to RFC 4122. (line 191) * uuid5: uuid — UUID objects according to RFC 4122. (line 200) * uuid5() (in module uuid): uuid — UUID objects according to RFC 4122. (line 195) * UuidCreate() (in module msilib): msilib — Read and write Microsoft Installer files. (line 39) * v4_int_to_packed() (in module ipaddress): Other Module Level Functions. (line 8) * v6_int_to_packed() (in module ipaddress): Other Module Level Functions. (line 20) * validator() (in module wsgiref.validate): wsgiref validate — WSGI conformance checker. (line 22) * valid_signals() (in module signal): Module contents<2>. (line 257) * value (ctypes._SimpleCData attribute): Fundamental data types<2>. (line 17) * value (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 32) * value (http.cookies.Morsel attribute): Morsel Objects. (line 52) * value (xml.dom.Attr attribute): Attr Objects. (line 23) * value of an object: Objects values and types. (line 11) * Value() (in module multiprocessing): Shared ctypes Objects. (line 9) * Value() (in module multiprocessing.sharedctypes): The multiprocessing sharedctypes module. (line 67) * Value() (multiprocessing.managers.SyncManager method): Managers. (line 200) * ValueError: Concrete exceptions. (line 377) * valuerefs() (weakref.WeakValueDictionary method): weakref — Weak references. (line 188) * values() (contextvars.Context method): Manual Context Management. (line 104) * values() (dict method): Mapping Types — dict. (line 222) * values() (email.message.EmailMessage method): email message Representing an email message. (line 236) * values() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 344) * values() (mailbox.Mailbox method): Mailbox objects. (line 114) * values() (types.MappingProxyType method): Standard Interpreter Types. (line 265) * ValuesView (class in collections.abc): Collections Abstract Base Classes. (line 187) * ValuesView (class in typing): Classes functions and decorators. (line 294) * value_decode() (http.cookies.BaseCookie method): Cookie Objects. (line 6) * value_encode() (http.cookies.BaseCookie method): Cookie Objects. (line 13) * var (contextvars.contextvars.Token.Token attribute): Context Variables. (line 82) * variable annotation: Glossary. (line 1288) * variance (statistics.NormalDist attribute): NormalDist objects. (line 40) * variance() (in module statistics): Function details. (line 344) * variant (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 139) * vars() (built-in function): Built-in Functions. (line 1703) * VBAR (in module token): token — Constants used with Python parse trees. (line 98) * vbar (tkinter.scrolledtext.ScrolledText attribute): tkinter scrolledtext — Scrolled Text Widget. (line 28) * VBAREQUAL (in module token): token — Constants used with Python parse trees. (line 194) * Vec2D (class in turtle): Public classes. (line 86) * vectorcallfunc (C type): Slot Type typedefs. (line 26) * venv (module): venv — Creation of virtual environments. (line 6) * VERBOSE (in module re): Module Contents. (line 120) * verbose (in module tabnanny): tabnanny — Detection of ambiguous indentation. (line 26) * verbose (in module test.support): test support — Utilities for the Python test suite. (line 30) * verify() (smtplib.SMTP method): SMTP Objects. (line 91) * VerifyFlags (class in ssl): Constants<9>. (line 112) * VerifyMode (class in ssl): Constants<9>. (line 64) * verify_client_post_handshake() (ssl.SSLSocket method): SSL Sockets. (line 281) * verify_code (ssl.SSLCertVerificationError attribute): Exceptions<12>. (line 86) * VERIFY_CRL_CHECK_CHAIN (in module ssl): Constants<9>. (line 89) * VERIFY_CRL_CHECK_LEAF (in module ssl): Constants<9>. (line 78) * VERIFY_DEFAULT (in module ssl): Constants<9>. (line 70) * verify_flags (ssl.SSLContext attribute): SSL Contexts. (line 640) * verify_message (ssl.SSLCertVerificationError attribute): Exceptions<12>. (line 90) * verify_mode (ssl.SSLContext attribute): SSL Contexts. (line 656) * verify_request() (socketserver.BaseServer method): Server Objects<2>. (line 175) * VERIFY_X509_STRICT (in module ssl): Constants<9>. (line 96) * VERIFY_X509_TRUSTED_FIRST (in module ssl): Constants<9>. (line 103) * version (email.headerregistry.MIMEVersionHeader attribute): email headerregistry Custom Header Objects. (line 242) * version (http.client.HTTPResponse attribute): HTTPResponse Objects. (line 46) * version (http.cookiejar.Cookie attribute): Cookie Objects<2>. (line 20) * version (in module curses): Constants<6>. (line 18) * version (in module marshal): marshal — Internal Python object serialization. (line 90) * version (in module sqlite3): Module functions and constants. (line 6) * version (in module sys): sys — System-specific parameters and functions. (line 1634) * version (in module sys) <1>: Process-wide parameters. (line 164) * version (in module sys) <2>: Process-wide parameters. (line 199) * version (in module sys) <3>: Process-wide parameters. (line 210) * version (ipaddress.IPv4Address attribute): Address objects. (line 39) * version (ipaddress.IPv4Network attribute): Network objects. (line 63) * version (ipaddress.IPv6Address attribute): Address objects. (line 167) * version (ipaddress.IPv6Network attribute): Network objects. (line 290) * version (urllib.request.URLopener attribute): Legacy interface. (line 139) * version (uuid.UUID attribute): uuid — UUID objects according to RFC 4122. (line 146) * version() (in module ensurepip): Module API. (line 8) * version() (in module platform): Cross Platform. (line 132) * version() (ssl.SSLSocket method): SSL Sockets. (line 303) * version_info (in module sqlite3): Module functions and constants. (line 11) * version_info (in module sys): sys — System-specific parameters and functions. (line 1649) * version_string() (http.server.BaseHTTPRequestHandler method): http server — HTTP servers. (line 304) * vformat() (string.Formatter method): Custom String Formatting. (line 26) * virtual environment: Glossary. (line 1310) * virtual machine: Glossary. (line 1319) * VIRTUAL_ENV: Creating virtual environments. (line 129) * visit() (ast.NodeVisitor method): ast Helpers. (line 129) * visitproc (C type): Supporting Cyclic Garbage Collection. (line 91) * vline() (curses.window method): Window Objects. (line 585) * voidcmd() (ftplib.FTP method): FTP Objects. (line 74) * volume (zipfile.ZipInfo attribute): ZipInfo Objects. (line 119) * vonmisesvariate() (in module random): Real-valued distributions. (line 75) * wait() (asyncio.asyncio.subprocess.Process method): Interacting with Subprocesses. (line 38) * wait() (asyncio.Condition method): Condition. (line 86) * wait() (asyncio.Event method): Event. (line 45) * wait() (in module asyncio): Waiting Primitives. (line 6) * wait() (in module concurrent.futures): Module Functions. (line 6) * wait() (in module multiprocessing.connection): Listeners and Clients. (line 113) * wait() (in module os): Process Management. (line 709) * wait() (multiprocessing.pool.AsyncResult method): Process Pools. (line 204) * wait() (subprocess.Popen method): Popen Objects. (line 13) * wait() (threading.Barrier method): Barrier Objects. (line 43) * wait() (threading.Condition method): Condition Objects. (line 97) * wait() (threading.Event method): Event Objects. (line 39) * wait3() (in module os): Process Management. (line 807) * wait4() (in module os): Process Management. (line 818) * waitid() (in module os): Process Management. (line 719) * waitpid() (in module os): Process Management. (line 770) * wait_closed() (asyncio.Server method): Server Objects. (line 95) * wait_closed() (asyncio.StreamWriter method): StreamWriter. (line 88) * wait_for() (asyncio.Condition method): Condition. (line 98) * wait_for() (in module asyncio): Timeouts. (line 6) * wait_for() (threading.Condition method): Condition Objects. (line 128) * wait_threads_exit() (in module test.support): test support — Utilities for the Python test suite. (line 521) * walk() (email.message.EmailMessage method): email message Representing an email message. (line 467) * walk() (email.message.Message method): email message Message Representing an email message using the compat32 API. (line 636) * walk() (in module ast): ast Helpers. (line 112) * walk() (in module os): Files and Directories. (line 1490) * walk_packages() (in module pkgutil): pkgutil — Package extension utility. (line 162) * walk_stack() (in module traceback): traceback — Print or retrieve a stack traceback. (line 157) * walk_tb() (in module traceback): traceback — Print or retrieve a stack traceback. (line 166) * want (doctest.Example attribute): Example Objects. (line 23) * warn() (distutils.ccompiler.CCompiler method): distutils ccompiler — CCompiler base class. (line 507) * warn() (distutils.text_file.TextFile method): distutils text_file — The TextFile class. (line 101) * warn() (in module warnings): Available Functions. (line 6) * Warning: Warnings. (line 9) * Warning <1>: Exceptions<4>. (line 6) * warning() (in module logging): Module-Level Functions. (line 124) * warning() (logging.Logger method): Logger Objects. (line 220) * warning() (xml.sax.handler.ErrorHandler method): ErrorHandler Objects. (line 29) * warnings: warnings — Warning control. (line 8) * warnings (module): warnings — Warning control. (line 6) * WarningsRecorder (class in test.support): test support — Utilities for the Python test suite. (line 1097) * warnoptions (in module sys): sys — System-specific parameters and functions. (line 1662) * warn_explicit() (in module warnings): Available Functions. (line 32) * wasSuccessful() (unittest.TestResult method): Loading and running tests. (line 302) * WatchedFileHandler (class in logging.handlers): WatchedFileHandler. (line 24) * wave (module): wave — Read and write WAV files. (line 6) * WCONTINUED (in module os): Process Management. (line 837) * WCOREDUMP() (in module os): Process Management. (line 857) * WeakKeyDictionary (class in weakref): weakref — Weak references. (line 158) * WeakMethod (class in weakref): weakref — Weak references. (line 197) * weakref (module): weakref — Weak references. (line 6) * WeakSet (class in weakref): weakref — Weak references. (line 192) * WeakValueDictionary (class in weakref): weakref — Weak references. (line 178) * webbrowser (module): webbrowser — Convenient Web-browser controller. (line 6) * weekday() (datetime.date method): date Objects. (line 200) * weekday() (datetime.datetime method): datetime Objects. (line 582) * weekday() (in module calendar): calendar — General calendar-related functions. (line 313) * weekheader() (in module calendar): calendar — General calendar-related functions. (line 318) * weibullvariate() (in module random): Real-valued distributions. (line 87) * WEXITED (in module os): Process Management. (line 747) * WEXITSTATUS() (in module os): Process Management. (line 903) * wfile (http.server.BaseHTTPRequestHandler attribute): http server — HTTP servers. (line 115) * what() (in module imghdr): imghdr — Determine the type of an image. (line 15) * what() (in module sndhdr): sndhdr — Determine type of sound file. (line 25) * whathdr() (in module sndhdr): sndhdr — Determine type of sound file. (line 34) * whatis (pdb command): Debugger Commands. (line 247) * when() (asyncio.TimerHandle method): Callback Handles. (line 29) * where (pdb command): Debugger Commands. (line 55) * which() (in module shutil): Directory and files operations. (line 370) * whichdb() (in module dbm): dbm — Interfaces to Unix “databases”. (line 23) * whitespace (in module string): String constants. (line 47) * whitespace (shlex.shlex attribute): shlex Objects. (line 104) * whitespace_split (shlex.shlex attribute): shlex Objects. (line 128) * Widget (class in tkinter.ttk): ttk Widget. (line 9) * width (textwrap.TextWrapper attribute): textwrap — Text wrapping and filling. (line 149) * width() (in module turtle): Drawing state. (line 18) * WIFCONTINUED() (in module os): Process Management. (line 867) * WIFEXITED() (in module os): Process Management. (line 895) * WIFSIGNALED() (in module os): Process Management. (line 888) * WIFSTOPPED() (in module os): Process Management. (line 877) * win32_edition() (in module platform): Windows Platform. (line 21) * win32_is_iot() (in module platform): Windows Platform. (line 29) * win32_ver() (in module platform): Windows Platform. (line 6) * WinDLL (class in ctypes): Loading shared libraries. (line 46) * window manager (widgets): The Window Manager. (line 6) * window() (curses.panel.Panel method): Panel Objects. (line 62) * Windows: Complete Python programs. (line 25) * Windows ini file: configparser — Configuration file parser. (line 8) * WindowsError: Concrete exceptions. (line 398) * WindowsPath (class in pathlib): Concrete paths. (line 32) * WindowsProactorEventLoopPolicy (class in asyncio): Policy Objects. (line 68) * WindowsRegistryFinder (class in importlib.machinery): importlib machinery – Importers and path hooks. (line 92) * WindowsSelectorEventLoopPolicy (class in asyncio): Policy Objects. (line 61) * window_height() (in module turtle): Settings and special methods. (line 103) * window_width() (in module turtle): Settings and special methods. (line 110) * winerror (OSError attribute): Concrete exceptions. (line 139) * WinError() (in module ctypes): Utility functions. (line 203) * WINFUNCTYPE() (in module ctypes): Function prototypes. (line 25) * winreg (module): winreg — Windows registry access. (line 6) * WinSock: select — Waiting for I/O completion. (line 146) * winsound (module): winsound — Sound-playing interface for Windows. (line 6) * winver (in module sys): sys — System-specific parameters and functions. (line 1668) * WITH_CLEANUP_FINISH (opcode): Python Bytecode Instructions. (line 468) * WITH_CLEANUP_START (opcode): Python Bytecode Instructions. (line 452) * with_hostmask (ipaddress.IPv4Interface attribute): Interface objects. (line 55) * with_hostmask (ipaddress.IPv4Network attribute): Network objects. (line 123) * with_hostmask (ipaddress.IPv6Interface attribute): Interface objects. (line 82) * with_hostmask (ipaddress.IPv6Network attribute): Network objects. (line 322) * with_name() (pathlib.PurePath method): Methods and properties. (line 259) * with_netmask (ipaddress.IPv4Interface attribute): Interface objects. (line 46) * with_netmask (ipaddress.IPv4Network attribute): Network objects. (line 118) * with_netmask (ipaddress.IPv6Interface attribute): Interface objects. (line 80) * with_netmask (ipaddress.IPv6Network attribute): Network objects. (line 320) * with_prefixlen (ipaddress.IPv4Interface attribute): Interface objects. (line 37) * with_prefixlen (ipaddress.IPv4Network attribute): Network objects. (line 105) * with_prefixlen (ipaddress.IPv6Interface attribute): Interface objects. (line 78) * with_prefixlen (ipaddress.IPv6Network attribute): Network objects. (line 314) * with_pymalloc() (in module test.support): test support — Utilities for the Python test suite. (line 207) * with_suffix() (pathlib.PurePath method): Methods and properties. (line 275) * with_traceback() (BaseException method): Base classes. (line 25) * WNOHANG (in module os): Process Management. (line 829) * WNOWAIT (in module os): Process Management. (line 747) * wordchars (shlex.shlex attribute): shlex Objects. (line 91) * World Wide Web: Internet Protocols and Support. (line 6) * World Wide Web <1>: urllib parse — Parse URLs into components. (line 8) * World Wide Web <2>: urllib robotparser — Parser for robots txt. (line 8) * wrap() (in module textwrap): textwrap — Text wrapping and filling. (line 16) * wrap() (textwrap.TextWrapper method): textwrap — Text wrapping and filling. (line 276) * wrapper() (in module curses): Functions<3>. (line 564) * WrapperDescriptorType (in module types): Standard Interpreter Types. (line 88) * wraps() (in module functools): functools — Higher-order functions and operations on callable objects. (line 533) * wrap_bio() (ssl.SSLContext method): SSL Contexts. (line 454) * wrap_future() (in module asyncio): Future Functions. (line 44) * wrap_socket() (in module ssl): Certificate handling. (line 167) * wrap_socket() (ssl.SSLContext method): SSL Contexts. (line 390) * wrap_text() (in module distutils.fancy_getopt): distutils fancy_getopt — Wrapper around the standard getopt module. (line 32) * WRITABLE (in module tkinter): File Handlers. (line 41) * writable() (asyncore.dispatcher method): asyncore — Asynchronous socket handler. (line 172) * writable() (io.IOBase method): I/O Base Classes. (line 152) * write() (asyncio.StreamWriter method): StreamWriter. (line 15) * write() (asyncio.WriteTransport method): Write-only Transports. (line 60) * write() (code.InteractiveInterpreter method): Interactive Interpreter Objects. (line 63) * write() (codecs.StreamWriter method): StreamWriter Objects. (line 31) * write() (configparser.ConfigParser method): ConfigParser Objects. (line 257) * write() (email.generator.BytesGenerator method): email generator Generating MIME documents. (line 118) * write() (email.generator.Generator method): email generator Generating MIME documents. (line 214) * write() (in module os): File Descriptor Operations. (line 676) * write() (in module turtle): More drawing control. (line 29) * write() (io.BufferedIOBase method): I/O Base Classes. (line 324) * write() (io.BufferedWriter method): Buffered Streams. (line 127) * write() (io.RawIOBase method): I/O Base Classes. (line 211) * write() (io.TextIOBase method): Text I/O<2>. (line 94) * write() (mmap.mmap method): mmap — Memory-mapped file support. (line 278) * write() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 39) * write() (ssl.MemoryBIO method): Memory BIO Support<2>. (line 153) * write() (ssl.SSLSocket method): SSL Sockets. (line 91) * write() (telnetlib.Telnet method): Telnet Objects. (line 101) * write() (xml.etree.ElementTree.ElementTree method): ElementTree Objects. (line 67) * write() (zipfile.ZipFile method): ZipFile Objects. (line 242) * writeall() (ossaudiodev.oss_audio_device method): Audio Device Objects. (line 51) * writeframes() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 187) * writeframes() (sunau.AU_write method): AU_write Objects. (line 52) * writeframes() (wave.Wave_write method): Wave_write Objects. (line 75) * writeframesraw() (aifc.aifc method): aifc — Read and write AIFF and AIFC files. (line 195) * writeframesraw() (sunau.AU_write method): AU_write Objects. (line 45) * writeframesraw() (wave.Wave_write method): Wave_write Objects. (line 68) * writeheader() (csv.DictWriter method): Writer Objects. (line 37) * writelines() (asyncio.StreamWriter method): StreamWriter. (line 26) * writelines() (asyncio.WriteTransport method): Write-only Transports. (line 67) * writelines() (codecs.StreamWriter method): StreamWriter Objects. (line 35) * writelines() (io.IOBase method): I/O Base Classes. (line 158) * writePlist() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 142) * writePlistToBytes() (in module plistlib): plistlib — Generate and parse Mac OS X plist files. (line 161) * writepy() (zipfile.PyZipFile method): PyZipFile Objects. (line 20) * writer (formatter.formatter attribute): The Formatter Interface. (line 22) * writer() (in module csv): Module Contents<3>. (line 40) * writerow() (csv.csvwriter method): Writer Objects. (line 15) * writerows() (csv.csvwriter method): Writer Objects. (line 23) * writestr() (zipfile.ZipFile method): ZipFile Objects. (line 266) * WriteTransport (class in asyncio): Transports Hierarchy. (line 11) * writev() (in module os): File Descriptor Operations. (line 695) * writexml() (xml.dom.minidom.Node method): DOM Objects. (line 27) * write_byte() (mmap.mmap method): mmap — Memory-mapped file support. (line 294) * write_bytes() (pathlib.Path method): Methods<2>. (line 437) * write_docstringdict() (in module turtle): Translation of docstrings into different languages. (line 10) * write_eof() (asyncio.StreamWriter method): StreamWriter. (line 52) * write_eof() (asyncio.WriteTransport method): Write-only Transports. (line 74) * write_eof() (ssl.MemoryBIO method): Memory BIO Support<2>. (line 161) * write_file() (in module distutils.file_util): distutils file_util — Single file operations. (line 44) * write_history_file() (in module readline): History file. (line 14) * WRITE_RESTRICTED: Generic Attribute Management. (line 92) * write_results() (trace.CoverageResults method): Programmatic Interface. (line 57) * write_text() (pathlib.Path method): Methods<2>. (line 452) * write_through (io.TextIOWrapper attribute): Text I/O<2>. (line 166) * writing; values: Expression statements. (line 17) * WrongDocumentErr: Exceptions<16>. (line 97) * wsgiref (module): wsgiref — WSGI Utilities and Reference Implementation. (line 6) * wsgiref.handlers (module): wsgiref handlers – server/gateway base classes. (line 6) * wsgiref.headers (module): wsgiref headers – WSGI response header tools. (line 6) * wsgiref.simple_server (module): wsgiref simple_server – a simple WSGI HTTP server. (line 6) * wsgiref.util (module): wsgiref util – WSGI environment utilities. (line 6) * wsgiref.validate (module): wsgiref validate — WSGI conformance checker. (line 6) * WSGIRequestHandler (class in wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server. (line 75) * WSGIServer (class in wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server. (line 45) * wsgi_file_wrapper (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 269) * wsgi_multiprocess (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 153) * wsgi_multithread (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 146) * wsgi_run_once (wsgiref.handlers.BaseHandler attribute): wsgiref handlers – server/gateway base classes. (line 160) * wShowWindow (subprocess.STARTUPINFO attribute): Windows Popen Helpers. (line 49) * WSTOPPED (in module os): Process Management. (line 747) * WSTOPSIG() (in module os): Process Management. (line 912) * wstring_at() (in module ctypes): Utility functions. (line 214) * ws_comma (2to3 fixer): Fixers. (line 325) * WTERMSIG() (in module os): Process Management. (line 921) * WUNTRACED (in module os): Process Management. (line 845) * WWW: Internet Protocols and Support. (line 6) * WWW <1>: urllib parse — Parse URLs into components. (line 8) * WWW <2>: urllib robotparser — Parser for robots txt. (line 8) * WWW; server: cgi — Common Gateway Interface support. (line 8) * WWW; server <1>: http server — HTTP servers. (line 8) * W_OK (in module os): Files and Directories. (line 106) * X (in module re): Module Contents. (line 120) * X509 certificate: SSL Contexts. (line 668) * xatom() (imaplib.IMAP4 method): IMAP4 Objects. (line 369) * XATTR_CREATE (in module os): Linux extended attributes. (line 87) * XATTR_REPLACE (in module os): Linux extended attributes. (line 93) * XATTR_SIZE_MAX (in module os): Linux extended attributes. (line 82) * xcor() (in module turtle): Tell Turtle’s state. (line 34) * XDR: xdrlib — Encode and decode XDR data. (line 8) * xdrlib (module): xdrlib — Encode and decode XDR data. (line 6) * xhdr() (nntplib.NNTP method): Methods<3>. (line 320) * XHTML: html parser — Simple HTML and XHTML parser. (line 8) * XHTML_NAMESPACE (in module xml.dom): Module Contents<4>. (line 53) * xml (module): XML Processing Modules. (line 6) * XML() (in module xml.etree.ElementTree): Functions<6>. (line 253) * xml.dom (module): xml dom — The Document Object Model API. (line 6) * xml.dom.minidom (module): xml dom minidom — Minimal DOM implementation. (line 6) * xml.dom.pulldom (module): xml dom pulldom — Support for building partial DOM trees. (line 6) * xml.etree.ElementInclude.default_loader() (in module xml.etree.ElementTree): Functions<7>. (line 6) * xml.etree.ElementInclude.include() (in module xml.etree.ElementTree): Functions<7>. (line 17) * xml.etree.ElementTree (module): xml etree ElementTree — The ElementTree XML API. (line 6) * xml.parsers.expat (module): xml parsers expat — Fast XML parsing using Expat. (line 6) * xml.parsers.expat.errors (module): Expat error constants. (line 6) * xml.parsers.expat.model (module): Content Model Descriptions. (line 6) * xml.sax (module): xml sax — Support for SAX2 parsers. (line 6) * xml.sax.handler (module): xml sax handler — Base classes for SAX handlers. (line 6) * xml.sax.saxutils (module): xml sax saxutils — SAX Utilities. (line 6) * xml.sax.xmlreader (module): xml sax xmlreader — Interface for XML parsers. (line 6) * xmlcharrefreplace_errors() (in module codecs): Error Handlers. (line 145) * XmlDeclHandler() (xml.parsers.expat.xmlparser method): XMLParser Objects<2>. (line 175) * XMLFilterBase (class in xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 68) * XMLGenerator (class in xml.sax.saxutils): xml sax saxutils — SAX Utilities. (line 52) * XMLID() (in module xml.etree.ElementTree): Functions<6>. (line 261) * XMLNS_NAMESPACE (in module xml.dom): Module Contents<4>. (line 47) * XMLParser (class in xml.etree.ElementTree): XMLParser Objects. (line 6) * XMLParserType (in module xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat. (line 35) * XMLPullParser (class in xml.etree.ElementTree): XMLPullParser Objects. (line 6) * XMLReader (class in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers. (line 16) * xmlrpc.client (module): xmlrpc client — XML-RPC client access. (line 6) * xmlrpc.server (module): xmlrpc server — Basic XML-RPC servers. (line 6) * XML_ERROR_ABORTED (in module xml.parsers.expat.errors): Expat error constants. (line 180) * XML_ERROR_ASYNC_ENTITY (in module xml.parsers.expat.errors): Expat error constants. (line 29) * XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF (in module xml.parsers.expat.errors): Expat error constants. (line 31) * XML_ERROR_BAD_CHAR_REF (in module xml.parsers.expat.errors): Expat error constants. (line 37) * XML_ERROR_BINARY_ENTITY_REF (in module xml.parsers.expat.errors): Expat error constants. (line 42) * XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING (in module xml.parsers.expat.errors): Expat error constants. (line 135) * XML_ERROR_DUPLICATE_ATTRIBUTE (in module xml.parsers.expat.errors): Expat error constants. (line 47) * XML_ERROR_ENTITY_DECLARED_IN_PE (in module xml.parsers.expat.errors): Expat error constants. (line 126) * XML_ERROR_EXTERNAL_ENTITY_HANDLING (in module xml.parsers.expat.errors): Expat error constants. (line 116) * XML_ERROR_FEATURE_REQUIRES_XML_DTD (in module xml.parsers.expat.errors): Expat error constants. (line 128) * XML_ERROR_FINISHED (in module xml.parsers.expat.errors): Expat error constants. (line 184) * XML_ERROR_INCOMPLETE_PE (in module xml.parsers.expat.errors): Expat error constants. (line 152) * XML_ERROR_INCORRECT_ENCODING (in module xml.parsers.expat.errors): Expat error constants. (line 51) * XML_ERROR_INVALID_TOKEN (in module xml.parsers.expat.errors): Expat error constants. (line 53) * XML_ERROR_JUNK_AFTER_DOC_ELEMENT (in module xml.parsers.expat.errors): Expat error constants. (line 59) * XML_ERROR_MISPLACED_XML_PI (in module xml.parsers.expat.errors): Expat error constants. (line 64) * XML_ERROR_NOT_STANDALONE (in module xml.parsers.expat.errors): Expat error constants. (line 118) * XML_ERROR_NOT_SUSPENDED (in module xml.parsers.expat.errors): Expat error constants. (line 175) * XML_ERROR_NO_ELEMENTS (in module xml.parsers.expat.errors): Expat error constants. (line 69) * XML_ERROR_NO_MEMORY (in module xml.parsers.expat.errors): Expat error constants. (line 74) * XML_ERROR_PARAM_ENTITY_REF (in module xml.parsers.expat.errors): Expat error constants. (line 78) * XML_ERROR_PARTIAL_CHAR (in module xml.parsers.expat.errors): Expat error constants. (line 82) * XML_ERROR_PUBLICID (in module xml.parsers.expat.errors): Expat error constants. (line 165) * XML_ERROR_RECURSIVE_ENTITY_REF (in module xml.parsers.expat.errors): Expat error constants. (line 86) * XML_ERROR_SUSPENDED (in module xml.parsers.expat.errors): Expat error constants. (line 169) * XML_ERROR_SUSPEND_PE (in module xml.parsers.expat.errors): Expat error constants. (line 190) * XML_ERROR_SYNTAX (in module xml.parsers.expat.errors): Expat error constants. (line 91) * XML_ERROR_TAG_MISMATCH (in module xml.parsers.expat.errors): Expat error constants. (line 95) * XML_ERROR_TEXT_DECL (in module xml.parsers.expat.errors): Expat error constants. (line 160) * XML_ERROR_UNBOUND_PREFIX (in module xml.parsers.expat.errors): Expat error constants. (line 142) * XML_ERROR_UNCLOSED_CDATA_SECTION (in module xml.parsers.expat.errors): Expat error constants. (line 112) * XML_ERROR_UNCLOSED_TOKEN (in module xml.parsers.expat.errors): Expat error constants. (line 99) * XML_ERROR_UNDECLARING_PREFIX (in module xml.parsers.expat.errors): Expat error constants. (line 147) * XML_ERROR_UNDEFINED_ENTITY (in module xml.parsers.expat.errors): Expat error constants. (line 104) * XML_ERROR_UNEXPECTED_STATE (in module xml.parsers.expat.errors): Expat error constants. (line 124) * XML_ERROR_UNKNOWN_ENCODING (in module xml.parsers.expat.errors): Expat error constants. (line 108) * XML_ERROR_XML_DECL (in module xml.parsers.expat.errors): Expat error constants. (line 156) * XML_NAMESPACE (in module xml.dom): Module Contents<4>. (line 42) * xor() (in module operator): operator — Standard operators as functions. (line 164) * xover() (nntplib.NNTP method): Methods<3>. (line 336) * xpath() (nntplib.NNTP method): Methods<3>. (line 344) * xrange (2to3 fixer): Fixers. (line 330) * xreadlines (2to3 fixer): Fixers. (line 335) * xview() (tkinter.ttk.Treeview method): ttk Treeview. (line 327) * X_OK (in module os): Files and Directories. (line 106) * ycor() (in module turtle): Tell Turtle’s state. (line 46) * year (datetime.date attribute): date Objects. (line 102) * year (datetime.datetime attribute): datetime Objects. (line 264) * Year 2038: time — Time access and conversions. (line 30) * yeardatescalendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 106) * yeardays2calendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 114) * yeardayscalendar() (calendar.Calendar method): calendar — General calendar-related functions. (line 121) * YESEXPR (in module locale): locale — Internationalization services. (line 241) * yield; examples: Generator-iterator methods. (line 57) * yield; expression: Yield expressions. (line 6) * yield; yield from (in What’s New): PEP 3151 Reworking the OS and IO exception hierarchy. (line 87) * YIELD_FROM (opcode): Python Bytecode Instructions. (line 350) * YIELD_VALUE (opcode): Python Bytecode Instructions. (line 346) * yiq_to_rgb() (in module colorsys): colorsys — Conversions between color systems. (line 32) * yview() (tkinter.ttk.Treeview method): ttk Treeview. (line 331) * Zen of Python: Glossary. (line 1325) * ZeroDivisionError: Concrete exceptions. (line 384) * zfill() (bytearray method): Bytes and Bytearray Operations. (line 683) * zfill() (bytes method): Bytes and Bytearray Operations. (line 683) * zfill() (str method): String Methods<2>. (line 604) * zip (2to3 fixer): Fixers. (line 339) * zip() (built-in function): Built-in Functions. (line 1723) * zipapp (module): zipapp — Manage executable Python zip archives. (line 6) * zipapp command line option; -c: Command-Line Interface<5>. (line 45) * zipapp command line option; –compress: Command-Line Interface<5>. (line 45) * zipapp command line option; -h: Command-Line Interface<5>. (line 61) * zipapp command line option; –help: Command-Line Interface<5>. (line 61) * zipapp command line option; –info: Command-Line Interface<5>. (line 55) * zipapp command line option; -m : Command-Line Interface<5>. (line 35) * zipapp command line option; –main=: Command-Line Interface<5>. (line 35) * zipapp command line option; -o : Command-Line Interface<5>. (line 18) * zipapp command line option; –output=: Command-Line Interface<5>. (line 18) * zipapp command line option; -p : Command-Line Interface<5>. (line 29) * zipapp command line option; –python=: Command-Line Interface<5>. (line 29) * ZipFile (class in zipfile): ZipFile Objects. (line 6) * zipfile (module): zipfile — Work with ZIP archives. (line 6) * zipfile command line option; -c ... : Command-line options. (line 11) * zipfile command line option; –create ... : Command-line options. (line 11) * zipfile command line option; -e : Command-line options. (line 16) * zipfile command line option; –extract : Command-line options. (line 16) * zipfile command line option; -l : Command-line options. (line 6) * zipfile command line option; –list : Command-line options. (line 6) * zipfile command line option; -t : Command-line options. (line 21) * zipfile command line option; –test : Command-line options. (line 21) * zipimport (module): zipimport — Import modules from Zip archives. (line 6) * zipimporter (class in zipimport): zipimporter Objects. (line 8) * ZipImportError: zipimport — Import modules from Zip archives. (line 55) * ZipInfo (class in zipfile): zipfile — Work with ZIP archives. (line 58) * ZIP_BZIP2 (in module zipfile): zipfile — Work with ZIP archives. (line 88) * ZIP_DEFLATED (in module zipfile): zipfile — Work with ZIP archives. (line 83) * zip_longest() (in module itertools): Itertool functions. (line 586) * ZIP_LZMA (in module zipfile): zipfile — Work with ZIP archives. (line 95) * ZIP_STORED (in module zipfile): zipfile — Work with ZIP archives. (line 79) * zlib (module): zlib — Compression compatible with gzip. (line 6) * ZLIB_RUNTIME_VERSION (in module zlib): zlib — Compression compatible with gzip. (line 309) * ZLIB_VERSION (in module zlib): zlib — Compression compatible with gzip. (line 302)  Tag Table: Node: Top344 Ref: contents doc545 Ref: 145545 Node: What’s New in Python166588 Ref: whatsnew/index doc166690 Ref: 146166690 Ref: whatsnew/index python-documentation-contents166690 Ref: 147166690 Ref: whatsnew/index what-s-new-in-python166690 Ref: 148166690 Ref: whatsnew/index whatsnew-index166690 Ref: 149166690 Node: What’s New In Python 3 8167965 Ref: whatsnew/3 8 doc168085 Ref: 14a168085 Ref: whatsnew/3 8 what-s-new-in-python-3-8168085 Ref: 14b168085 Node: Summary – Release highlights168946 Ref: whatsnew/3 8 summary-release-highlights169060 Ref: 14d169060 Node: New Features169133 Ref: whatsnew/3 8 new-features169278 Ref: 14e169278 Node: Assignment expressions169884 Ref: whatsnew/3 8 assignment-expressions169990 Ref: 14f169990 Ref: Assignment expressions-Footnote-1171496 Ref: Assignment expressions-Footnote-2171593 Ref: Assignment expressions-Footnote-3171642 Node: Positional-only parameters171685 Ref: whatsnew/3 8 positional-only-parameters171853 Ref: 151171853 Ref: Positional-only parameters-Footnote-1174535 Ref: Positional-only parameters-Footnote-2174587 Ref: Positional-only parameters-Footnote-3174636 Node: Parallel filesystem cache for compiled bytecode files174679 Ref: whatsnew/3 8 parallel-filesystem-cache-for-compiled-bytecode-files174871 Ref: 153174871 Ref: Parallel filesystem cache for compiled bytecode files-Footnote-1175513 Node: Debug build uses the same ABI as release build175556 Ref: whatsnew/3 8 debug-build-uses-the-same-abi-as-release-build175788 Ref: 158175788 Ref: Debug build uses the same ABI as release build-Footnote-1178123 Ref: Debug build uses the same ABI as release build-Footnote-2178166 Ref: Debug build uses the same ABI as release build-Footnote-3178209 Ref: Debug build uses the same ABI as release build-Footnote-4178252 Node: f-strings support = for self-documenting expressions and debugging178295 Ref: whatsnew/3 8 f-strings-support-for-self-documenting-expressions-and-debugging178508 Ref: 15a178508 Ref: f-strings support = for self-documenting expressions and debugging-Footnote-1179597 Node: PEP 578 Python Runtime Audit Hooks179640 Ref: whatsnew/3 8 pep-578-python-runtime-audit-hooks179850 Ref: 15d179850 Ref: PEP 578 Python Runtime Audit Hooks-Footnote-1180333 Node: PEP 587 Python Initialization Configuration180382 Ref: whatsnew/3 8 pep-587-python-initialization-configuration180572 Ref: 15e180572 Ref: PEP 587 Python Initialization Configuration-Footnote-1182559 Ref: PEP 587 Python Initialization Configuration-Footnote-2182608 Ref: PEP 587 Python Initialization Configuration-Footnote-3182657 Node: Vectorcall a fast calling protocol for CPython182700 Ref: whatsnew/3 8 vectorcall-a-fast-calling-protocol-for-cpython182903 Ref: 17e182903 Ref: Vectorcall a fast calling protocol for CPython-Footnote-1183463 Ref: Vectorcall a fast calling protocol for CPython-Footnote-2183512 Node: Pickle protocol 5 with out-of-band data buffers183555 Ref: whatsnew/3 8 pickle-protocol-5-with-out-of-band-data-buffers183706 Ref: 17f183706 Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-1184458 Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-2184507 Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-3184556 Node: Other Language Changes184599 Ref: whatsnew/3 8 other-language-changes184725 Ref: 180184725 Ref: Other Language Changes-Footnote-1192102 Ref: Other Language Changes-Footnote-2192145 Ref: Other Language Changes-Footnote-3192188 Ref: Other Language Changes-Footnote-4192231 Ref: Other Language Changes-Footnote-5192274 Ref: Other Language Changes-Footnote-6192317 Ref: Other Language Changes-Footnote-7192360 Ref: Other Language Changes-Footnote-8192403 Ref: Other Language Changes-Footnote-9192446 Ref: Other Language Changes-Footnote-10192489 Ref: Other Language Changes-Footnote-11192533 Ref: Other Language Changes-Footnote-12192579 Ref: Other Language Changes-Footnote-13192623 Ref: Other Language Changes-Footnote-14192693 Ref: Other Language Changes-Footnote-15192753 Ref: Other Language Changes-Footnote-16192797 Ref: Other Language Changes-Footnote-17192841 Node: New Modules192885 Ref: whatsnew/3 8 new-modules193015 Ref: 19d193015 Ref: New Modules-Footnote-1194088 Node: Improved Modules194131 Ref: whatsnew/3 8 improved-modules194252 Ref: 19e194252 Node: ast194876 Ref: whatsnew/3 8 ast194948 Ref: 19f194948 Ref: ast-Footnote-1195980 Ref: ast-Footnote-2196023 Ref: ast-Footnote-3196072 Ref: ast-Footnote-4196121 Ref: ast-Footnote-5196170 Node: asyncio196213 Ref: whatsnew/3 8 asyncio196302 Ref: 1a4196302 Ref: asyncio-Footnote-1199458 Ref: asyncio-Footnote-2199501 Ref: asyncio-Footnote-3199544 Ref: asyncio-Footnote-4199587 Ref: asyncio-Footnote-5199630 Ref: asyncio-Footnote-6199673 Ref: asyncio-Footnote-7199716 Ref: asyncio-Footnote-8199759 Ref: asyncio-Footnote-9199802 Ref: asyncio-Footnote-10199855 Node: builtins199899 Ref: whatsnew/3 8 builtins199996 Ref: 1b3199996 Ref: builtins-Footnote-1200495 Node: collections200538 Ref: whatsnew/3 8 collections200636 Ref: 1b5200636 Ref: collections-Footnote-1201158 Node: cProfile201201 Ref: whatsnew/3 8 cprofile201294 Ref: 1ba201294 Ref: cProfile-Footnote-1201644 Node: csv201687 Ref: whatsnew/3 8 csv201775 Ref: 1bc201775 Ref: csv-Footnote-1202092 Node: curses202135 Ref: whatsnew/3 8 curses202221 Ref: 1be202221 Ref: curses-Footnote-1202465 Node: ctypes202508 Ref: whatsnew/3 8 ctypes202599 Ref: 1c0202599 Ref: ctypes-Footnote-1203088 Node: datetime203131 Ref: whatsnew/3 8 datetime203225 Ref: 1c3203225 Ref: datetime-Footnote-1203653 Node: functools203696 Ref: whatsnew/3 8 functools203786 Ref: 1c6203786 Ref: functools-Footnote-1205328 Ref: functools-Footnote-2205371 Ref: functools-Footnote-3205414 Node: gc205457 Ref: whatsnew/3 8 gc205546 Ref: 1cc205546 Ref: gc-Footnote-1205779 Node: gettext205822 Ref: whatsnew/3 8 gettext205906 Ref: 1ce205906 Ref: gettext-Footnote-1206107 Node: gzip206149 Ref: whatsnew/3 8 gzip206247 Ref: 1d0206247 Ref: gzip-Footnote-1206664 Ref: gzip-Footnote-2206707 Node: IDLE and idlelib206749 Ref: whatsnew/3 8 idle-and-idlelib206847 Ref: 1d4206847 Ref: IDLE and idlelib-Footnote-1208816 Ref: IDLE and idlelib-Footnote-2208861 Ref: IDLE and idlelib-Footnote-3208903 Ref: IDLE and idlelib-Footnote-4208946 Ref: IDLE and idlelib-Footnote-5208989 Ref: IDLE and idlelib-Footnote-6209032 Ref: IDLE and idlelib-Footnote-7209074 Ref: IDLE and idlelib-Footnote-8209117 Node: inspect209160 Ref: whatsnew/3 8 inspect209256 Ref: 1d5209256 Ref: inspect-Footnote-1210022 Node: io210065 Ref: whatsnew/3 8 io210154 Ref: 1da210154 Ref: io-Footnote-1210490 Node: itertools210533 Ref: whatsnew/3 8 itertools210624 Ref: 1dc210624 Ref: itertools-Footnote-1211002 Node: json tool211045 Ref: whatsnew/3 8 json-tool211141 Ref: 1de211141 Ref: json tool-Footnote-1211348 Node: logging211391 Ref: whatsnew/3 8 logging211482 Ref: 1df211482 Ref: logging-Footnote-1212198 Node: math212241 Ref: whatsnew/3 8 math212327 Ref: 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plistlib219616 Ref: whatsnew/3 8 plistlib219707 Ref: 20f219707 Ref: plistlib-Footnote-1219945 Node: pprint219988 Ref: whatsnew/3 8 pprint220083 Ref: 211220083 Ref: pprint-Footnote-1221148 Node: py_compile221191 Ref: whatsnew/3 8 py-compile221283 Ref: 214221283 Ref: py_compile-Footnote-1221472 Node: shlex221515 Ref: whatsnew/3 8 shlex221607 Ref: 216221607 Ref: shlex-Footnote-1221811 Node: shutil221854 Ref: whatsnew/3 8 shutil221942 Ref: 219221942 Ref: shutil-Footnote-1222596 Ref: shutil-Footnote-2222639 Ref: shutil-Footnote-3222682 Node: socket222725 Ref: whatsnew/3 8 socket222811 Ref: 21d222811 Ref: socket-Footnote-1223386 Ref: socket-Footnote-2223429 Node: ssl223472 Ref: whatsnew/3 8 ssl223562 Ref: 223223562 Ref: ssl-Footnote-1223824 Node: statistics223867 Ref: whatsnew/3 8 statistics223954 Ref: 226223954 Ref: statistics-Footnote-1225685 Ref: statistics-Footnote-2225728 Ref: statistics-Footnote-3225771 Ref: statistics-Footnote-4225814 Ref: statistics-Footnote-5225857 Node: sys225900 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Ref: API and Feature Removals-Footnote-11257527 Node: Porting to Python 3 8257571 Ref: whatsnew/3 8 porting-to-python-3-8257728 Ref: 2ae257728 Node: Changes in Python behavior258039 Ref: whatsnew/3 8 changes-in-python-behavior258157 Ref: 2af258157 Ref: Changes in Python behavior-Footnote-1260537 Ref: Changes in Python behavior-Footnote-2260580 Ref: Changes in Python behavior-Footnote-3260623 Ref: Changes in Python behavior-Footnote-4260666 Ref: Changes in Python behavior-Footnote-5260709 Ref: Changes in Python behavior-Footnote-6260752 Node: Changes in the Python API260795 Ref: whatsnew/3 8 changes-in-the-python-api260942 Ref: 2b7260942 Ref: whatsnew/3 8 bpo-36085-whatsnew267908 Ref: 2ca267908 Ref: Changes in the Python API-Footnote-1269458 Ref: Changes in the Python API-Footnote-2269507 Ref: Changes in the Python API-Footnote-3269550 Ref: Changes in the Python API-Footnote-4269593 Ref: Changes in the Python API-Footnote-5269636 Ref: Changes in the Python API-Footnote-6269679 Ref: Changes in the Python API-Footnote-7269722 Ref: Changes in the Python API-Footnote-8269765 Ref: Changes in the Python API-Footnote-9269808 Ref: Changes in the Python API-Footnote-10269851 Ref: Changes in the Python API-Footnote-11269895 Ref: Changes in the Python API-Footnote-12269939 Ref: Changes in the Python API-Footnote-13269983 Ref: Changes in the Python API-Footnote-14270027 Ref: Changes in the Python API-Footnote-15270071 Ref: Changes in the Python API-Footnote-16270115 Ref: Changes in the Python API-Footnote-17270159 Ref: Changes in the Python API-Footnote-18270202 Ref: Changes in the Python API-Footnote-19270246 Ref: Changes in the Python API-Footnote-20270290 Ref: Changes in the Python API-Footnote-21270334 Ref: Changes in the Python API-Footnote-22270378 Ref: Changes in the Python API-Footnote-23270422 Ref: Changes in the Python API-Footnote-24270466 Ref: Changes in the Python API-Footnote-25270510 Ref: Changes in the Python API-Footnote-26270554 Ref: Changes in the Python 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dis-Footnote-1330277 Node: distutils330320 Ref: whatsnew/3 7 distutils330410 Ref: 385330410 Ref: distutils-Footnote-1330658 Node: enum330701 Ref: whatsnew/3 7 enum330800 Ref: 386330800 Ref: enum-Footnote-1331468 Ref: enum-Footnote-2331511 Node: functools<2>331554 Ref: whatsnew/3 7 functools331649 Ref: 389331649 Ref: functools<2>-Footnote-1331878 Node: gc<2>331921 Ref: whatsnew/3 7 gc332016 Ref: 38b332016 Ref: gc<2>-Footnote-1332555 Node: hmac332598 Ref: whatsnew/3 7 hmac332692 Ref: 38f332692 Ref: hmac-Footnote-1332950 Node: http client332993 Ref: whatsnew/3 7 http-client333093 Ref: 391333093 Ref: http client-Footnote-1333350 Node: http server333393 Ref: whatsnew/3 7 http-server333505 Ref: 394333505 Ref: http server-Footnote-1334383 Ref: http server-Footnote-2334426 Ref: http server-Footnote-3334469 Node: idlelib and IDLE334512 Ref: whatsnew/3 7 idlelib-and-idle334622 Ref: 397334622 Ref: idlelib and IDLE-Footnote-1337631 Ref: idlelib and IDLE-Footnote-2337674 Ref: idlelib and IDLE-Footnote-3337719 Ref: idlelib and IDLE-Footnote-4337762 Ref: idlelib and IDLE-Footnote-5337805 Ref: idlelib and IDLE-Footnote-6337848 Ref: idlelib and IDLE-Footnote-7337891 Ref: idlelib and IDLE-Footnote-8337934 Ref: idlelib and IDLE-Footnote-9337977 Ref: idlelib and IDLE-Footnote-10338020 Ref: idlelib and IDLE-Footnote-11338066 Ref: idlelib and IDLE-Footnote-12338109 Ref: idlelib and IDLE-Footnote-13338153 Node: importlib338197 Ref: whatsnew/3 7 importlib338301 Ref: 398338301 Ref: importlib-Footnote-1339172 Ref: importlib-Footnote-2339215 Ref: importlib-Footnote-3339258 Node: io<2>339301 Ref: whatsnew/3 7 io339398 Ref: 39c339398 Ref: io<2>-Footnote-1339663 Ref: io<2>-Footnote-2339706 Node: ipaddress339749 Ref: whatsnew/3 7 ipaddress339849 Ref: 39e339849 Ref: ipaddress-Footnote-1340169 Node: itertools<2>340212 Ref: whatsnew/3 7 itertools340313 Ref: 3a1340313 Ref: itertools<2>-Footnote-1340550 Node: locale340593 Ref: whatsnew/3 7 locale340695 Ref: 3a3340695 Ref: 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subprocess-Footnote-4358045 Node: sys<2>358088 Ref: whatsnew/3 7 sys358185 Ref: 3f0358185 Ref: sys<2>-Footnote-1358925 Ref: sys<2>-Footnote-2358968 Ref: sys<2>-Footnote-3359011 Node: time<2>359054 Ref: whatsnew/3 7 time359151 Ref: 3f4359151 Ref: time<2>-Footnote-1360361 Ref: time<2>-Footnote-2360410 Node: tkinter<2>360453 Ref: whatsnew/3 7 tkinter360555 Ref: 3fc360555 Ref: tkinter<2>-Footnote-1360736 Node: tracemalloc360779 Ref: whatsnew/3 7 tracemalloc360879 Ref: 3fe360879 Ref: tracemalloc-Footnote-1361345 Node: types361388 Ref: whatsnew/3 7 types361492 Ref: 401361492 Ref: types-Footnote-1362007 Ref: types-Footnote-2362050 Ref: types-Footnote-3362093 Ref: types-Footnote-4362142 Node: unicodedata<2>362185 Ref: whatsnew/3 7 unicodedata362289 Ref: 407362289 Ref: unicodedata<2>-Footnote-1362492 Node: unittest<2>362547 Ref: whatsnew/3 7 unittest362659 Ref: 408362659 Ref: unittest<2>-Footnote-1363064 Node: unittest mock363107 Ref: whatsnew/3 7 unittest-mock363217 Ref: 409363217 Ref: unittest mock-Footnote-1363735 Ref: unittest mock-Footnote-2363778 Node: urllib parse363821 Ref: whatsnew/3 7 urllib-parse363922 Ref: 40c363922 Ref: urllib parse-Footnote-1364235 Ref: urllib parse-Footnote-2364284 Ref: urllib parse-Footnote-3364333 Node: uu364376 Ref: whatsnew/3 7 uu364468 Ref: 40e364468 Ref: uu-Footnote-1364740 Node: uuid364783 Ref: whatsnew/3 7 uuid364871 Ref: 410364871 Ref: uuid-Footnote-1365511 Ref: uuid-Footnote-2365554 Node: warnings365597 Ref: whatsnew/3 7 warnings365692 Ref: 414365692 Ref: warnings-Footnote-1367146 Ref: warnings-Footnote-2367189 Ref: warnings-Footnote-3367232 Ref: warnings-Footnote-4367275 Node: xml etree367318 Ref: whatsnew/3 7 xml-etree367422 Ref: 419367422 Ref: xml etree-Footnote-1367763 Node: xmlrpc server367806 Ref: whatsnew/3 7 xmlrpc-server367908 Ref: 41b367908 Ref: xmlrpc server-Footnote-1368117 Node: zipapp368159 Ref: whatsnew/3 7 zipapp368259 Ref: 41c368259 Ref: zipapp-Footnote-1368783 Ref: zipapp-Footnote-2368826 Node: zipfile368869 Ref: whatsnew/3 7 zipfile368947 Ref: 41e368947 Ref: zipfile-Footnote-1369312 Ref: zipfile-Footnote-2369355 Node: C API Changes369398 Ref: whatsnew/3 7 c-api-changes369524 Ref: 420369524 Ref: C API Changes-Footnote-1374036 Ref: C API Changes-Footnote-2374079 Ref: C API Changes-Footnote-3374122 Ref: C API Changes-Footnote-4374165 Ref: C API Changes-Footnote-5374208 Ref: C API Changes-Footnote-6374251 Ref: C API Changes-Footnote-7374294 Ref: C API Changes-Footnote-8374337 Ref: C API Changes-Footnote-9374380 Ref: C API Changes-Footnote-10374423 Ref: C API Changes-Footnote-11374467 Ref: C API Changes-Footnote-12374511 Ref: C API Changes-Footnote-13374555 Ref: C API Changes-Footnote-14374599 Ref: C API Changes-Footnote-15374643 Ref: C API Changes-Footnote-16374686 Ref: C API Changes-Footnote-17374730 Ref: C API Changes-Footnote-18374774 Ref: C API Changes-Footnote-19374818 Ref: C API Changes-Footnote-20374862 Node: Build Changes374906 Ref: whatsnew/3 7 build-changes375029 Ref: 441375029 Ref: Build Changes-Footnote-1376163 Ref: Build Changes-Footnote-2376206 Ref: Build Changes-Footnote-3376249 Node: Optimizations<2>376292 Ref: whatsnew/3 7 optimizations376438 Ref: 442376438 Ref: whatsnew/3 7 whatsnew37-perf376438 Ref: 306376438 Ref: whatsnew/3 7 whatsnew37-asyncio-perf377132 Ref: 347377132 Ref: Optimizations<2>-Footnote-1381686 Ref: Optimizations<2>-Footnote-2381729 Ref: Optimizations<2>-Footnote-3381772 Ref: Optimizations<2>-Footnote-4381815 Ref: Optimizations<2>-Footnote-5381858 Ref: Optimizations<2>-Footnote-6381901 Ref: Optimizations<2>-Footnote-7381944 Ref: Optimizations<2>-Footnote-8381987 Ref: Optimizations<2>-Footnote-9382030 Ref: Optimizations<2>-Footnote-10382073 Ref: Optimizations<2>-Footnote-11382117 Ref: Optimizations<2>-Footnote-12382161 Ref: Optimizations<2>-Footnote-13382205 Ref: Optimizations<2>-Footnote-14382249 Ref: Optimizations<2>-Footnote-15382293 Ref: Optimizations<2>-Footnote-16382337 Ref: Optimizations<2>-Footnote-17382381 Ref: Optimizations<2>-Footnote-18382425 Ref: Optimizations<2>-Footnote-19382469 Ref: Optimizations<2>-Footnote-20382513 Ref: Optimizations<2>-Footnote-21382557 Ref: Optimizations<2>-Footnote-22382601 Ref: Optimizations<2>-Footnote-23382645 Ref: Optimizations<2>-Footnote-24382689 Ref: Optimizations<2>-Footnote-25382733 Ref: Optimizations<2>-Footnote-26382777 Ref: Optimizations<2>-Footnote-27382821 Ref: Optimizations<2>-Footnote-28382865 Ref: Optimizations<2>-Footnote-29382909 Ref: Optimizations<2>-Footnote-30382953 Node: Other CPython Implementation Changes382997 Ref: whatsnew/3 7 other-cpython-implementation-changes383156 Ref: 454383156 Ref: Other CPython Implementation Changes-Footnote-1384557 Ref: Other CPython Implementation Changes-Footnote-2384600 Ref: Other CPython Implementation Changes-Footnote-3384643 Ref: Other CPython Implementation Changes-Footnote-4384686 Ref: Other CPython Implementation Changes-Footnote-5384729 Node: Deprecated Python Behavior384772 Ref: whatsnew/3 7 deprecated-python-behavior384962 Ref: 456384962 Ref: Deprecated Python Behavior-Footnote-1386071 Ref: Deprecated Python Behavior-Footnote-2386114 Node: Deprecated Python modules functions and methods386157 Ref: whatsnew/3 7 deprecated-python-modules-functions-and-methods386354 Ref: 459386354 Node: aifc386752 Ref: whatsnew/3 7 aifc386859 Ref: 45a386859 Ref: aifc-Footnote-1387085 Node: asyncio<3>387128 Ref: whatsnew/3 7 id2387258 Ref: 45c387258 Ref: whatsnew/3 7 whatsnew37-asyncio-deprecated387258 Ref: 36b387258 Ref: asyncio<3>-Footnote-1387794 Ref: asyncio<3>-Footnote-2387837 Node: collections<3>387880 Ref: whatsnew/3 7 id3388012 Ref: 45d388012 Ref: collections<3>-Footnote-1388391 Node: dbm<2>388434 Ref: whatsnew/3 7 id4388563 Ref: 45e388563 Ref: dbm<2>-Footnote-1388964 Node: enum<2>389007 Ref: whatsnew/3 7 id5389132 Ref: 45f389132 Ref: enum<2>-Footnote-1389582 Node: gettext<2>389625 Ref: whatsnew/3 7 gettext389756 Ref: 460389756 Ref: gettext<2>-Footnote-1390001 Node: importlib<2>390044 Ref: whatsnew/3 7 id6390177 Ref: 461390177 Ref: importlib<2>-Footnote-1390703 Node: locale<2>390746 Ref: whatsnew/3 7 id7390876 Ref: 467390876 Ref: locale<2>-Footnote-1391085 Node: macpath391128 Ref: whatsnew/3 7 macpath391258 Ref: 469391258 Ref: macpath-Footnote-1391448 Node: threading<2>391490 Ref: whatsnew/3 7 threading391620 Ref: 46a391620 Ref: threading<2>-Footnote-1391928 Node: socket<3>391971 Ref: whatsnew/3 7 id8392100 Ref: 46b392100 Ref: socket<3>-Footnote-1392445 Node: ssl<3>392488 Ref: whatsnew/3 7 id9392610 Ref: 46e392610 Ref: ssl<3>-Footnote-1392828 Node: sunau392871 Ref: whatsnew/3 7 sunau392990 Ref: 470392990 Ref: sunau-Footnote-1393229 Node: sys<3>393272 Ref: whatsnew/3 7 id10393389 Ref: 473393389 Ref: sys<3>-Footnote-1393706 Node: wave393749 Ref: whatsnew/3 7 wave393852 Ref: 474393852 Ref: wave-Footnote-1394087 Node: Deprecated functions and types of the C API394130 Ref: whatsnew/3 7 deprecated-functions-and-types-of-the-c-api394326 Ref: 477394326 Ref: Deprecated functions and types of the C API-Footnote-1394984 Ref: Deprecated functions and types of the C API-Footnote-2395027 Node: Platform Support Removals395070 Ref: whatsnew/3 7 id11395246 Ref: 479395246 Ref: whatsnew/3 7 platform-support-removals395246 Ref: 3df395246 Ref: Platform Support Removals-Footnote-1396658 Ref: Platform Support Removals-Footnote-2396721 Node: API and Feature Removals<2>396800 Ref: whatsnew/3 7 api-and-feature-removals396948 Ref: 47a396948 Ref: API and Feature Removals<2>-Footnote-1399917 Ref: API and Feature Removals<2>-Footnote-2399960 Ref: API and Feature Removals<2>-Footnote-3400003 Node: Module Removals400046 Ref: whatsnew/3 7 module-removals400189 Ref: 482400189 Ref: Module Removals-Footnote-1400524 Node: Windows-only Changes400567 Ref: whatsnew/3 7 windows-only-changes400704 Ref: 483400704 Ref: Windows-only Changes-Footnote-1401581 Ref: Windows-only Changes-Footnote-2401624 Node: Porting to Python 3 7401667 Ref: whatsnew/3 7 porting-to-python-3-7401820 Ref: 484401820 Ref: whatsnew/3 7 porting-to-python-37401820 Ref: 307401820 Node: Changes in Python Behavior402282 Ref: whatsnew/3 7 changes-in-python-behavior402403 Ref: 485402403 Ref: Changes in Python Behavior-Footnote-1404269 Ref: Changes in Python Behavior-Footnote-2404312 Ref: Changes in Python Behavior-Footnote-3404361 Ref: Changes in Python Behavior-Footnote-4404404 Ref: Changes in Python Behavior-Footnote-5404447 Ref: Changes in Python Behavior-Footnote-6404490 Node: Changes in the Python API<2>404533 Ref: whatsnew/3 7 changes-in-the-python-api404686 Ref: 489404686 Ref: Changes in the Python API<2>-Footnote-1414237 Ref: Changes in the Python API<2>-Footnote-2414280 Ref: Changes in the Python API<2>-Footnote-3414323 Ref: Changes in the Python API<2>-Footnote-4414366 Ref: Changes in the Python API<2>-Footnote-5414409 Ref: Changes in the Python API<2>-Footnote-6414452 Ref: Changes in the Python API<2>-Footnote-7414495 Ref: Changes in the Python API<2>-Footnote-8414538 Ref: Changes in the Python API<2>-Footnote-9414581 Ref: Changes in the Python API<2>-Footnote-10414624 Ref: Changes in the Python API<2>-Footnote-11414668 Ref: Changes in the Python API<2>-Footnote-12414712 Ref: Changes in the Python API<2>-Footnote-13414756 Ref: Changes in the Python API<2>-Footnote-14414800 Ref: Changes in the Python API<2>-Footnote-15414843 Ref: Changes in the Python API<2>-Footnote-16414887 Ref: Changes in the Python API<2>-Footnote-17414931 Ref: Changes in the Python API<2>-Footnote-18414975 Ref: Changes in the Python API<2>-Footnote-19415019 Ref: Changes in the Python API<2>-Footnote-20415063 Ref: Changes in the Python API<2>-Footnote-21415107 Ref: Changes in the Python API<2>-Footnote-22415151 Ref: Changes in the Python API<2>-Footnote-23415195 Ref: Changes in the Python API<2>-Footnote-24415239 Ref: Changes in the Python API<2>-Footnote-25415283 Ref: Changes in the Python API<2>-Footnote-26415327 Ref: Changes in the Python API<2>-Footnote-27415371 Ref: Changes in the Python API<2>-Footnote-28415415 Ref: Changes in the Python API<2>-Footnote-29415459 Ref: Changes in the Python API<2>-Footnote-30415503 Node: Changes in the C API<2>415547 Ref: whatsnew/3 7 changes-in-the-c-api415701 Ref: 4ab415701 Ref: Changes in the C API<2>-Footnote-1416337 Node: CPython bytecode changes<2>416380 Ref: whatsnew/3 7 cpython-bytecode-changes416529 Ref: 4ac416529 Ref: CPython bytecode changes<2>-Footnote-1416881 Ref: CPython bytecode changes<2>-Footnote-2416924 Node: Windows-only Changes<2>416967 Ref: whatsnew/3 7 id12417129 Ref: 4af417129 Ref: Windows-only Changes<2>-Footnote-1417450 Node: Other CPython implementation changes417493 Ref: whatsnew/3 7 id13417619 Ref: 4b1417619 Ref: Other CPython implementation changes-Footnote-1419967 Ref: Other CPython implementation changes-Footnote-2420016 Ref: Other CPython implementation changes-Footnote-3420059 Node: Notable changes in Python 3 7 1420102 Ref: whatsnew/3 7 notable-changes-in-python-3-7-1420266 Ref: 4b6420266 Ref: Notable changes in Python 3 7 1-Footnote-1421206 Ref: Notable changes in Python 3 7 1-Footnote-2421249 Ref: Notable changes in Python 3 7 1-Footnote-3421292 Node: Notable changes in Python 3 7 2421335 Ref: whatsnew/3 7 notable-changes-in-python-3-7-2421509 Ref: 4bb421509 Node: Notable changes in Python 3 7 6422004 Ref: whatsnew/3 7 notable-changes-in-python-3-7-6422179 Ref: 4bc422179 Ref: Notable changes in Python 3 7 6-Footnote-1422690 Node: Notable changes in Python 3 7 10422733 Ref: whatsnew/3 7 notable-changes-in-python-3-7-10422868 Ref: 4bd422868 Ref: Notable changes in Python 3 7 10-Footnote-1423600 Node: What’s New In Python 3 6423643 Ref: whatsnew/3 6 doc423798 Ref: 4be423798 Ref: whatsnew/3 6 what-s-new-in-python-3-6423798 Ref: 4bf423798 Ref: What’s New In Python 3 6-Footnote-1425061 Ref: What’s New In Python 3 6-Footnote-2425121 Node: Summary – Release highlights<2>425170 Ref: whatsnew/3 6 summary-release-highlights425290 Ref: 4c0425290 Ref: Summary – Release highlights<2>-Footnote-1429531 Ref: Summary – Release highlights<2>-Footnote-2429611 Ref: Summary – Release highlights<2>-Footnote-3429701 Node: New Features<3>429750 Ref: whatsnew/3 6 new-features429904 Ref: 4d7429904 Ref: whatsnew/3 6 pypy-dict-implementation429904 Ref: 4d8429904 Node: PEP 498 Formatted string literals431314 Ref: whatsnew/3 6 pep-498-formatted-string-literals431447 Ref: 4d9431447 Ref: whatsnew/3 6 whatsnew36-pep498431447 Ref: 4c1431447 Ref: PEP 498 Formatted string literals-Footnote-1432431 Ref: PEP 498 Formatted string literals-Footnote-2432480 Node: PEP 526 Syntax for variable annotations432529 Ref: whatsnew/3 6 pep-526-syntax-for-variable-annotations432710 Ref: 4dc432710 Ref: whatsnew/3 6 whatsnew36-pep526432710 Ref: 4c3432710 Ref: PEP 526 Syntax for variable annotations-Footnote-1433954 Ref: PEP 526 Syntax for variable annotations-Footnote-2434003 Ref: PEP 526 Syntax for variable annotations-Footnote-3434052 Ref: PEP 526 Syntax for variable annotations-Footnote-4434086 Node: PEP 515 Underscores in Numeric Literals434127 Ref: whatsnew/3 6 pep-515-underscores-in-numeric-literals434306 Ref: 4dd434306 Ref: whatsnew/3 6 whatsnew36-pep515434306 Ref: 4c2434306 Ref: PEP 515 Underscores in Numeric Literals-Footnote-1435375 Ref: PEP 515 Underscores in Numeric Literals-Footnote-2435424 Node: PEP 525 Asynchronous Generators435473 Ref: whatsnew/3 6 pep-525-asynchronous-generators435648 Ref: 4df435648 Ref: whatsnew/3 6 whatsnew36-pep525435648 Ref: 4c4435648 Ref: PEP 525 Asynchronous Generators-Footnote-1436483 Ref: PEP 525 Asynchronous Generators-Footnote-2436532 Node: PEP 530 Asynchronous Comprehensions436581 Ref: whatsnew/3 6 pep-530-asynchronous-comprehensions436764 Ref: 4e0436764 Ref: whatsnew/3 6 whatsnew36-pep530436764 Ref: 4c5436764 Ref: PEP 530 Asynchronous Comprehensions-Footnote-1437322 Ref: PEP 530 Asynchronous Comprehensions-Footnote-2437371 Node: PEP 487 Simpler customization of class creation437420 Ref: whatsnew/3 6 pep-487-simpler-customization-of-class-creation437612 Ref: 4e1437612 Ref: whatsnew/3 6 whatsnew36-pep487437612 Ref: 4c8437612 Ref: PEP 487 Simpler customization of class creation-Footnote-1438704 Node: PEP 487 Descriptor Protocol Enhancements438753 Ref: whatsnew/3 6 pep-487-descriptor-protocol-enhancements438952 Ref: 4e6438952 Ref: whatsnew/3 6 whatsnew36-pep487-descriptors438952 Ref: 4e7438952 Ref: PEP 487 Descriptor Protocol Enhancements-Footnote-1440203 Ref: PEP 487 Descriptor Protocol Enhancements-Footnote-2440252 Node: PEP 519 Adding a file system path protocol440301 Ref: whatsnew/3 6 pep-519-adding-a-file-system-path-protocol440486 Ref: 4ea440486 Ref: whatsnew/3 6 whatsnew36-pep519440486 Ref: 4cd440486 Ref: PEP 519 Adding a file system path protocol-Footnote-1443313 Node: PEP 495 Local Time Disambiguation443362 Ref: whatsnew/3 6 pep-495-local-time-disambiguation443558 Ref: 4f2443558 Ref: whatsnew/3 6 whatsnew36-pep495443558 Ref: 4ce443558 Ref: PEP 495 Local Time Disambiguation-Footnote-1444971 Ref: PEP 495 Local Time Disambiguation-Footnote-2445020 Node: PEP 529 Change Windows filesystem encoding to UTF-8445069 Ref: whatsnew/3 6 pep-529-change-windows-filesystem-encoding-to-utf-8445271 Ref: 4f5445271 Ref: whatsnew/3 6 whatsnew36-pep529445271 Ref: 4d4445271 Ref: PEP 529 Change Windows filesystem encoding to UTF-8-Footnote-1446301 Node: PEP 528 Change Windows console encoding to UTF-8446350 Ref: whatsnew/3 6 pep-528-change-windows-console-encoding-to-utf-8446570 Ref: 4f9446570 Ref: whatsnew/3 6 whatsnew36-pep528446570 Ref: 4d3446570 Ref: PEP 528 Change Windows console encoding to UTF-8-Footnote-1447273 Node: PEP 520 Preserving Class Attribute Definition Order447322 Ref: whatsnew/3 6 pep-520-preserving-class-attribute-definition-order447532 Ref: 4fb447532 Ref: whatsnew/3 6 whatsnew36-pep520447532 Ref: 4c9447532 Ref: PEP 520 Preserving Class Attribute Definition Order-Footnote-1448172 Node: PEP 468 Preserving Keyword Argument Order448221 Ref: whatsnew/3 6 pep-468-preserving-keyword-argument-order448406 Ref: 4fe448406 Ref: whatsnew/3 6 whatsnew36-pep468448406 Ref: 4ca448406 Ref: PEP 468 Preserving Keyword Argument Order-Footnote-1448767 Node: New dict implementation448816 Ref: whatsnew/3 6 new-dict-implementation448998 Ref: 4ff448998 Ref: whatsnew/3 6 whatsnew36-compactdict448998 Ref: 4c7448998 Ref: New dict implementation-Footnote-1449976 Ref: New dict implementation-Footnote-2450056 Ref: New dict implementation-Footnote-3450146 Ref: New dict implementation-Footnote-4450189 Node: PEP 523 Adding a frame evaluation API to CPython450269 Ref: whatsnew/3 6 pep-523-adding-a-frame-evaluation-api-to-cpython450443 Ref: 500450443 Ref: whatsnew/3 6 whatsnew36-pep523450443 Ref: 501450443 Ref: PEP 523 Adding a frame evaluation API to CPython-Footnote-1451614 Ref: PEP 523 Adding a frame evaluation API to CPython-Footnote-2451663 Node: PYTHONMALLOC environment variable451712 Ref: whatsnew/3 6 pythonmalloc-environment-variable451899 Ref: 502451899 Ref: whatsnew/3 6 whatsnew36-pythonmalloc451899 Ref: 4cc451899 Ref: PYTHONMALLOC environment variable-Footnote-1455082 Ref: PYTHONMALLOC environment variable-Footnote-2455125 Node: DTrace and SystemTap probing support455168 Ref: whatsnew/3 6 dtrace-and-systemtap-probing-support455298 Ref: 50b455298 Ref: whatsnew/3 6 whatsnew36-tracing455298 Ref: 4cb455298 Ref: DTrace and SystemTap probing support-Footnote-1456129 Node: Other Language Changes<3>456172 Ref: whatsnew/3 6 other-language-changes456307 Ref: 50d456307 Ref: Other Language Changes<3>-Footnote-1457692 Ref: Other Language Changes<3>-Footnote-2457735 Ref: Other Language Changes<3>-Footnote-3457778 Ref: Other Language Changes<3>-Footnote-4457821 Node: New Modules<3>457864 Ref: whatsnew/3 6 new-modules458003 Ref: 511458003 Node: secrets458062 Ref: whatsnew/3 6 secrets458120 Ref: 512458120 Ref: whatsnew/3 6 whatsnew36-pep506458120 Ref: 4c6458120 Ref: secrets-Footnote-1458803 Node: Improved Modules<3>458852 Ref: whatsnew/3 6 improved-modules458982 Ref: 513458982 Node: array460363 Ref: whatsnew/3 6 array460439 Ref: 514460439 Ref: array-Footnote-1460732 Node: ast<2>460775 Ref: whatsnew/3 6 ast460870 Ref: 515460870 Ref: ast<2>-Footnote-1461113 Node: asyncio<4>461156 Ref: whatsnew/3 6 asyncio461257 Ref: 516461257 Ref: asyncio<4>-Footnote-1464597 Ref: asyncio<4>-Footnote-2464640 Ref: asyncio<4>-Footnote-3464685 Ref: asyncio<4>-Footnote-4464728 Ref: asyncio<4>-Footnote-5464771 Ref: asyncio<4>-Footnote-6464814 Ref: asyncio<4>-Footnote-7464857 Ref: asyncio<4>-Footnote-8464900 Ref: asyncio<4>-Footnote-9464943 Ref: asyncio<4>-Footnote-10464986 Ref: asyncio<4>-Footnote-11465030 Ref: asyncio<4>-Footnote-12465074 Node: binascii<2>465118 Ref: whatsnew/3 6 binascii465218 Ref: 522465218 Ref: binascii<2>-Footnote-1465503 Node: cmath465546 Ref: whatsnew/3 6 cmath465650 Ref: 524465650 Ref: cmath-Footnote-1466121 Ref: cmath-Footnote-2466164 Ref: cmath-Footnote-3466213 Node: collections<4>466256 Ref: whatsnew/3 6 collections466370 Ref: 52c466370 Ref: collections<4>-Footnote-1467471 Ref: collections<4>-Footnote-2467514 Ref: collections<4>-Footnote-3467557 Ref: collections<4>-Footnote-4467600 Ref: collections<4>-Footnote-5467643 Ref: collections<4>-Footnote-6467686 Node: concurrent futures<2>467729 Ref: whatsnew/3 6 concurrent-futures467851 Ref: 532467851 Ref: concurrent futures<2>-Footnote-1468181 Node: contextlib<2>468224 Ref: whatsnew/3 6 contextlib468343 Ref: 533468343 Ref: contextlib<2>-Footnote-1468839 Node: datetime<3>468882 Ref: whatsnew/3 6 datetime468990 Ref: 536468990 Ref: datetime<3>-Footnote-1470007 Ref: datetime<3>-Footnote-2470050 Ref: datetime<3>-Footnote-3470093 Ref: datetime<3>-Footnote-4470136 Node: decimal<2>470179 Ref: whatsnew/3 6 decimal470286 Ref: 53a470286 Ref: decimal<2>-Footnote-1470699 Node: distutils<2>470742 Ref: whatsnew/3 6 distutils470843 Ref: 53c470843 Ref: distutils<2>-Footnote-1471217 Node: email471260 Ref: whatsnew/3 6 email471360 Ref: 53d471360 Ref: email-Footnote-1472276 Ref: email-Footnote-2472319 Ref: email-Footnote-3472362 Node: encodings472405 Ref: whatsnew/3 6 encodings472500 Ref: 543472500 Ref: encodings-Footnote-1472795 Node: enum<3>472838 Ref: whatsnew/3 6 enum472940 Ref: 544472940 Ref: enum<3>-Footnote-1473688 Node: faulthandler473731 Ref: whatsnew/3 6 faulthandler473833 Ref: 547473833 Ref: faulthandler-Footnote-1474096 Node: fileinput474139 Ref: whatsnew/3 6 fileinput474241 Ref: 549474241 Ref: fileinput-Footnote-1474429 Node: hashlib474472 Ref: whatsnew/3 6 hashlib474576 Ref: 54b474576 Ref: hashlib-Footnote-1475594 Ref: hashlib-Footnote-2475637 Ref: hashlib-Footnote-3475680 Ref: hashlib-Footnote-4475723 Node: http client<2>475766 Ref: whatsnew/3 6 http-client475880 Ref: 54e475880 Ref: http client<2>-Footnote-1476140 Node: idlelib and IDLE<2>476183 Ref: whatsnew/3 6 idlelib-and-idle476302 Ref: 551476302 Ref: idlelib and IDLE<2>-Footnote-1479776 Ref: idlelib and IDLE<2>-Footnote-2479819 Ref: idlelib and IDLE<2>-Footnote-3479862 Ref: idlelib and IDLE<2>-Footnote-4479907 Ref: idlelib and IDLE<2>-Footnote-5479950 Ref: idlelib and IDLE<2>-Footnote-6479993 Ref: idlelib and IDLE<2>-Footnote-7480036 Ref: idlelib and IDLE<2>-Footnote-8480079 Ref: idlelib and IDLE<2>-Footnote-9480122 Ref: idlelib and IDLE<2>-Footnote-10480165 Ref: idlelib and IDLE<2>-Footnote-11480209 Node: importlib<3>480255 Ref: whatsnew/3 6 importlib480370 Ref: 552480370 Ref: importlib<3>-Footnote-1481197 Node: inspect<2>481240 Ref: whatsnew/3 6 inspect481340 Ref: 55a481340 Ref: inspect<2>-Footnote-1482121 Ref: inspect<2>-Footnote-2482164 Node: json482207 Ref: whatsnew/3 6 json482305 Ref: 55e482305 Ref: json-Footnote-1482577 Node: logging<3>482620 Ref: whatsnew/3 6 logging482715 Ref: 561482715 Ref: logging<3>-Footnote-1482979 Node: math<3>483022 Ref: whatsnew/3 6 math483131 Ref: 563483131 Ref: math<3>-Footnote-1483363 Ref: math<3>-Footnote-2483406 Node: multiprocessing<3>483455 Ref: whatsnew/3 6 multiprocessing483559 Ref: 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whatsnew/3 6 notable-changes-in-python-3-6-10547884 Ref: 626547884 Ref: Notable changes in Python 3 6 10-Footnote-1548397 Node: Notable changes in Python 3 6 13548440 Ref: whatsnew/3 6 notable-changes-in-python-3-6-13548576 Ref: 627548576 Ref: Notable changes in Python 3 6 13-Footnote-1549308 Node: What’s New In Python 3 5549351 Ref: whatsnew/3 5 doc549506 Ref: 628549506 Ref: whatsnew/3 5 what-s-new-in-python-3-5549506 Ref: 629549506 Ref: What’s New In Python 3 5-Footnote-1550445 Ref: What’s New In Python 3 5-Footnote-2550505 Node: Summary – Release highlights<3>550554 Ref: whatsnew/3 5 summary-release-highlights550674 Ref: 62a550674 Ref: Summary – Release highlights<3>-Footnote-1554403 Ref: Summary – Release highlights<3>-Footnote-2554445 Ref: Summary – Release highlights<3>-Footnote-3554488 Ref: Summary – Release highlights<3>-Footnote-4554531 Ref: Summary – Release highlights<3>-Footnote-5554574 Ref: Summary – Release highlights<3>-Footnote-6554617 Ref: Summary – Release highlights<3>-Footnote-7554660 Node: New Features<4>554703 Ref: whatsnew/3 5 new-features554857 Ref: 63d554857 Node: PEP 492 - Coroutines with async and await syntax555953 Ref: whatsnew/3 5 pep-492-coroutines-with-async-and-await-syntax556124 Ref: 63e556124 Ref: whatsnew/3 5 whatsnew-pep-492556124 Ref: 62b556124 Ref: PEP 492 - Coroutines with async and await syntax-Footnote-1559203 Ref: PEP 492 - Coroutines with async and await syntax-Footnote-2559252 Node: PEP 465 - A dedicated infix operator for matrix multiplication559301 Ref: whatsnew/3 5 pep-465-a-dedicated-infix-operator-for-matrix-multiplication559527 Ref: 647559527 Ref: whatsnew/3 5 whatsnew-pep-465559527 Ref: 62c559527 Ref: PEP 465 - A dedicated infix operator for matrix multiplication-Footnote-1560930 Ref: PEP 465 - A dedicated infix operator for matrix multiplication-Footnote-2560979 Node: PEP 448 - Additional Unpacking Generalizations561028 Ref: whatsnew/3 5 pep-448-additional-unpacking-generalizations561266 Ref: 64b561266 Ref: whatsnew/3 5 whatsnew-pep-448561266 Ref: 62d561266 Ref: PEP 448 - Additional Unpacking Generalizations-Footnote-1562359 Ref: PEP 448 - Additional Unpacking Generalizations-Footnote-2562408 Node: PEP 461 - percent formatting support for bytes and bytearray562457 Ref: whatsnew/3 5 pep-461-percent-formatting-support-for-bytes-and-bytearray562653 Ref: 64f562653 Ref: whatsnew/3 5 whatsnew-pep-461562653 Ref: 630562653 Ref: PEP 461 - percent formatting support for bytes and bytearray-Footnote-1564189 Ref: PEP 461 - percent formatting support for bytes and bytearray-Footnote-2564238 Node: PEP 484 - Type Hints564287 Ref: whatsnew/3 5 pep-484-type-hints564509 Ref: 651564509 Ref: whatsnew/3 5 whatsnew-pep-484564509 Ref: 62e564509 Ref: PEP 484 - Type Hints-Footnote-1566156 Ref: PEP 484 - Type Hints-Footnote-2566205 Ref: PEP 484 - Type Hints-Footnote-3566254 Ref: PEP 484 - Type Hints-Footnote-4566283 Ref: PEP 484 - Type Hints-Footnote-5566332 Node: PEP 471 - os scandir function – a better and faster directory iterator566381 Ref: whatsnew/3 5 pep-471-os-scandir-function-a-better-and-faster-directory-iterator566588 Ref: 653566588 Ref: whatsnew/3 5 whatsnew-pep-471566588 Ref: 639566588 Ref: PEP 471 - os scandir function – a better and faster directory iterator-Footnote-1567944 Ref: PEP 471 - os scandir function – a better and faster directory iterator-Footnote-2567993 Node: PEP 475 Retry system calls failing with EINTR568042 Ref: whatsnew/3 5 pep-475-retry-system-calls-failing-with-eintr568284 Ref: 656568284 Ref: whatsnew/3 5 whatsnew-pep-475568284 Ref: 657568284 Ref: PEP 475 Retry system calls failing with EINTR-Footnote-1571348 Ref: PEP 475 Retry system calls failing with EINTR-Footnote-2571397 Node: PEP 479 Change StopIteration handling inside generators571446 Ref: whatsnew/3 5 pep-479-change-stopiteration-handling-inside-generators571667 Ref: 681571667 Ref: whatsnew/3 5 whatsnew-pep-479571667 Ref: 5d7571667 Ref: PEP 479 Change StopIteration handling inside generators-Footnote-1573597 Ref: PEP 479 Change StopIteration handling inside generators-Footnote-2573646 Node: PEP 485 A function for testing approximate equality573695 Ref: whatsnew/3 5 pep-485-a-function-for-testing-approximate-equality573933 Ref: 684573933 Ref: whatsnew/3 5 whatsnew-pep-485573933 Ref: 685573933 Ref: PEP 485 A function for testing approximate equality-Footnote-1575116 Ref: PEP 485 A function for testing approximate equality-Footnote-2575165 Node: PEP 486 Make the Python Launcher aware of virtual environments575214 Ref: whatsnew/3 5 pep-486-make-the-python-launcher-aware-of-virtual-environments575429 Ref: 688575429 Ref: whatsnew/3 5 whatsnew-pep-486575429 Ref: 689575429 Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-1576003 Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-2576052 Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-3576101 Node: PEP 488 Elimination of PYO files576150 Ref: whatsnew/3 5 pep-488-elimination-of-pyo-files576365 Ref: 68a576365 Ref: whatsnew/3 5 whatsnew-pep-488576365 Ref: 635576365 Ref: PEP 488 Elimination of PYO files-Footnote-1577231 Ref: PEP 488 Elimination of PYO files-Footnote-2577280 Node: PEP 489 Multi-phase extension module initialization577329 Ref: whatsnew/3 5 pep-489-multi-phase-extension-module-initialization577473 Ref: 68d577473 Ref: whatsnew/3 5 whatsnew-pep-489577473 Ref: 636577473 Ref: PEP 489 Multi-phase extension module initialization-Footnote-1578236 Ref: PEP 489 Multi-phase extension module initialization-Footnote-2578285 Ref: PEP 489 Multi-phase extension module initialization-Footnote-3578334 Node: Other Language Changes<4>578383 Ref: whatsnew/3 5 other-language-changes578518 Ref: 68e578518 Ref: Other Language Changes<4>-Footnote-1579516 Ref: Other Language Changes<4>-Footnote-2579559 Ref: Other Language Changes<4>-Footnote-3579602 Ref: Other Language Changes<4>-Footnote-4579645 Ref: Other Language Changes<4>-Footnote-5579688 Ref: Other Language Changes<4>-Footnote-6579731 Ref: Other Language Changes<4>-Footnote-7579774 Node: New Modules<4>579817 Ref: whatsnew/3 5 new-modules579956 Ref: 690579956 Node: typing<3>580045 Ref: whatsnew/3 5 typing580123 Ref: 691580123 Node: zipapp<2>580334 Ref: whatsnew/3 5 whatsnew-zipapp580412 Ref: 62f580412 Ref: whatsnew/3 5 zipapp580412 Ref: 692580412 Ref: zipapp<2>-Footnote-1581122 Ref: zipapp<2>-Footnote-2581171 Ref: zipapp<2>-Footnote-3581216 Ref: zipapp<2>-Footnote-4581259 Node: Improved Modules<4>581308 Ref: whatsnew/3 5 improved-modules581448 Ref: 693581448 Node: argparse<2>583012 Ref: whatsnew/3 5 argparse583098 Ref: 694583098 Ref: argparse<2>-Footnote-1583421 Node: asyncio<5>583464 Ref: whatsnew/3 5 asyncio583562 Ref: 698583562 Ref: asyncio<5>-Footnote-1587040 Ref: asyncio<5>-Footnote-2587083 Ref: asyncio<5>-Footnote-3587126 Node: bz2587171 Ref: whatsnew/3 5 bz2587261 Ref: 6a2587261 Ref: bz2-Footnote-1587516 Node: cgi587559 Ref: whatsnew/3 5 cgi587647 Ref: 6a4587647 Ref: cgi-Footnote-1587842 Node: cmath<2>587885 Ref: whatsnew/3 5 cmath587974 Ref: 6a5587974 Ref: cmath<2>-Footnote-1588188 Node: code588231 Ref: whatsnew/3 5 code588331 Ref: 6a6588331 Ref: code-Footnote-1588582 Node: collections<5>588625 Ref: whatsnew/3 5 collections588732 Ref: 6a8588732 Ref: whatsnew/3 5 whatsnew-ordereddict588773 Ref: 637588773 Ref: collections<5>-Footnote-1590052 Ref: collections<5>-Footnote-2590095 Ref: collections<5>-Footnote-3590138 Ref: collections<5>-Footnote-4590181 Ref: collections<5>-Footnote-5590224 Node: collections abc590267 Ref: whatsnew/3 5 collections-abc590383 Ref: 6b4590383 Ref: collections abc-Footnote-1591053 Ref: collections abc-Footnote-2591096 Ref: collections abc-Footnote-3591139 Ref: collections abc-Footnote-4591182 Node: compileall<2>591229 Ref: whatsnew/3 5 compileall591352 Ref: 6ba591352 Ref: compileall<2>-Footnote-1592229 Ref: compileall<2>-Footnote-2592272 Ref: compileall<2>-Footnote-3592315 Node: concurrent 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6cc597508 Ref: doctest-Footnote-1597793 Node: email<2>597836 Ref: whatsnew/3 5 email597932 Ref: 6cf597932 Ref: email<2>-Footnote-1599043 Ref: email<2>-Footnote-2599086 Ref: email<2>-Footnote-3599129 Ref: email<2>-Footnote-4599178 Ref: email<2>-Footnote-5599227 Ref: email<2>-Footnote-6599270 Node: enum<4>599313 Ref: whatsnew/3 5 enum599417 Ref: 6d5599417 Ref: enum<4>-Footnote-1599808 Node: faulthandler<2>599851 Ref: whatsnew/3 5 faulthandler599959 Ref: 6d6599959 Ref: faulthandler<2>-Footnote-1600271 Node: functools<3>600314 Ref: whatsnew/3 5 functools600419 Ref: 6da600419 Ref: whatsnew/3 5 whatsnew-lrucache600458 Ref: 63a600458 Ref: functools<3>-Footnote-1600684 Node: glob600727 Ref: whatsnew/3 5 glob600824 Ref: 6db600824 Ref: glob-Footnote-1601076 Node: gzip<2>601119 Ref: whatsnew/3 5 gzip601209 Ref: 6dc601209 Ref: gzip<2>-Footnote-1601434 Node: heapq601477 Ref: whatsnew/3 5 heapq601567 Ref: 6de601567 Ref: heapq-Footnote-1602207 Node: http602250 Ref: whatsnew/3 5 http602347 Ref: 6e1602347 Ref: http-Footnote-1602593 Node: http client<3>602636 Ref: whatsnew/3 5 http-client602747 Ref: 6e3602747 Ref: http client<3>-Footnote-1603491 Node: idlelib and IDLE<3>603533 Ref: whatsnew/3 5 idlelib-and-idle603647 Ref: 6e7603647 Node: imaplib604041 Ref: whatsnew/3 5 imaplib604147 Ref: 6e8604147 Ref: imaplib-Footnote-1605026 Ref: imaplib-Footnote-2605068 Ref: imaplib-Footnote-3605117 Ref: imaplib-Footnote-4605166 Ref: imaplib-Footnote-5605215 Ref: imaplib-Footnote-6605258 Node: imghdr605301 Ref: whatsnew/3 5 imghdr605400 Ref: 6ec605400 Ref: imghdr-Footnote-1605694 Ref: imghdr-Footnote-2605725 Ref: imghdr-Footnote-3605768 Ref: imghdr-Footnote-4605811 Node: importlib<5>605854 Ref: whatsnew/3 5 importlib605956 Ref: 6ee605956 Ref: importlib<5>-Footnote-1606791 Ref: importlib<5>-Footnote-2606834 Ref: importlib<5>-Footnote-3606877 Node: inspect<3>606920 Ref: whatsnew/3 5 inspect607021 Ref: 6f2607021 Ref: inspect<3>-Footnote-1608578 Ref: inspect<3>-Footnote-2608621 Ref: inspect<3>-Footnote-3608664 Ref: inspect<3>-Footnote-4608707 Ref: inspect<3>-Footnote-5608750 Ref: inspect<3>-Footnote-6608793 Ref: inspect<3>-Footnote-7608836 Ref: inspect<3>-Footnote-8608879 Node: io<3>608922 Ref: whatsnew/3 5 io609023 Ref: 700609023 Ref: io<3>-Footnote-1609321 Node: ipaddress<2>609364 Ref: whatsnew/3 5 ipaddress609462 Ref: 704609462 Ref: ipaddress<2>-Footnote-1610490 Ref: ipaddress<2>-Footnote-2610533 Node: json<2>610576 Ref: whatsnew/3 5 json610678 Ref: 705610678 Ref: json<2>-Footnote-1611178 Ref: json<2>-Footnote-2611221 Node: linecache611264 Ref: whatsnew/3 5 linecache611363 Ref: 707611363 Ref: linecache-Footnote-1611773 Node: locale<3>611816 Ref: whatsnew/3 5 locale611918 Ref: 70a611918 Ref: locale<3>-Footnote-1612483 Node: logging<4>612526 Ref: whatsnew/3 5 logging612623 Ref: 70c612623 Ref: logging<4>-Footnote-1613593 Ref: logging<4>-Footnote-2613636 Node: lzma613679 Ref: whatsnew/3 5 lzma613774 Ref: 713613774 Ref: lzma-Footnote-1614036 Node: math<4>614079 Ref: whatsnew/3 5 math614182 Ref: 715614182 Ref: math<4>-Footnote-1614730 Ref: math<4>-Footnote-2614773 Ref: math<4>-Footnote-3614816 Node: multiprocessing<4>614859 Ref: whatsnew/3 5 multiprocessing614966 Ref: 718614966 Ref: multiprocessing<4>-Footnote-1615216 Node: operator615259 Ref: whatsnew/3 5 operator615364 Ref: 71a615364 Ref: operator-Footnote-1615769 Ref: operator-Footnote-2615812 Node: os<5>615855 Ref: whatsnew/3 5 os615952 Ref: 71f615952 Ref: os<5>-Footnote-1617800 Ref: os<5>-Footnote-2617843 Ref: os<5>-Footnote-3617886 Ref: os<5>-Footnote-4617929 Ref: os<5>-Footnote-5617972 Ref: os<5>-Footnote-6618015 Node: pathlib<4>618058 Ref: whatsnew/3 5 pathlib618156 Ref: 727618156 Ref: pathlib<4>-Footnote-1619627 Ref: pathlib<4>-Footnote-2619670 Ref: pathlib<4>-Footnote-3619713 Ref: pathlib<4>-Footnote-4619756 Ref: pathlib<4>-Footnote-5619799 Node: pickle<3>619842 Ref: whatsnew/3 5 pickle619941 Ref: 730619941 Ref: pickle<3>-Footnote-1620257 Node: poplib620300 Ref: whatsnew/3 5 poplib620394 Ref: 731620394 Ref: poplib-Footnote-1620636 Ref: poplib-Footnote-2620685 Node: re<4>620728 Ref: whatsnew/3 5 re620824 Ref: 733620824 Ref: re<4>-Footnote-1622060 Ref: re<4>-Footnote-2622102 Ref: re<4>-Footnote-3622145 Ref: re<4>-Footnote-4622190 Node: readline<2>622233 Ref: whatsnew/3 5 readline622332 Ref: 73b622332 Ref: readline<2>-Footnote-1622595 Node: selectors622638 Ref: whatsnew/3 5 selectors622741 Ref: 73d622741 Ref: selectors-Footnote-1622963 Node: shutil<2>623006 Ref: whatsnew/3 5 shutil623107 Ref: 73e623107 Ref: shutil<2>-Footnote-1623586 Ref: shutil<2>-Footnote-2623629 Node: signal<2>623671 Ref: whatsnew/3 5 signal623768 Ref: 73f623768 Ref: signal<2>-Footnote-1624235 Ref: signal<2>-Footnote-2624278 Node: smtpd624321 Ref: whatsnew/3 5 smtpd624416 Ref: 740624416 Ref: smtpd-Footnote-1626100 Ref: smtpd-Footnote-2626143 Ref: smtpd-Footnote-3626192 Ref: smtpd-Footnote-4626235 Ref: smtpd-Footnote-5626284 Ref: smtpd-Footnote-6626327 Node: smtplib626370 Ref: whatsnew/3 5 smtplib626462 Ref: 741626462 Ref: smtplib-Footnote-1627083 Ref: smtplib-Footnote-2627126 Ref: smtplib-Footnote-3627169 Ref: smtplib-Footnote-4627218 Node: sndhdr627261 Ref: whatsnew/3 5 sndhdr627357 Ref: 746627357 Ref: sndhdr-Footnote-1627572 Node: socket<5>627615 Ref: whatsnew/3 5 socket627710 Ref: 749627710 Ref: socket<5>-Footnote-1628681 Ref: socket<5>-Footnote-2628724 Ref: socket<5>-Footnote-3628767 Ref: socket<5>-Footnote-4628810 Node: ssl<6>628853 Ref: whatsnew/3 5 ssl628952 Ref: 74d628952 Node: Memory BIO Support629081 Ref: whatsnew/3 5 memory-bio-support629197 Ref: 74e629197 Ref: whatsnew/3 5 whatsnew-sslmemorybio629197 Ref: 638629197 Ref: Memory BIO Support-Footnote-1630080 Node: Application-Layer Protocol Negotiation Support630123 Ref: whatsnew/3 5 application-layer-protocol-negotiation-support630261 Ref: 750630261 Ref: Application-Layer Protocol Negotiation Support-Footnote-1630966 Ref: Application-Layer Protocol Negotiation Support-Footnote-2631009 Node: Other Changes631058 Ref: whatsnew/3 5 other-changes631169 Ref: 754631169 Ref: Other Changes-Footnote-1632762 Ref: Other Changes-Footnote-2632805 Ref: Other Changes-Footnote-3632848 Ref: Other Changes-Footnote-4632891 Ref: Other Changes-Footnote-5632940 Ref: Other Changes-Footnote-6632983 Ref: Other Changes-Footnote-7633026 Ref: Other Changes-Footnote-8633069 Node: sqlite3<3>633112 Ref: whatsnew/3 5 sqlite3633215 Ref: 75d633215 Ref: sqlite3<3>-Footnote-1633544 Ref: sqlite3<3>-Footnote-2633587 Node: subprocess<3>633630 Ref: whatsnew/3 5 subprocess633733 Ref: 75f633733 Ref: whatsnew/3 5 whatsnew-subprocess633733 Ref: 63b633733 Ref: subprocess<3>-Footnote-1634747 Node: sys<5>634790 Ref: whatsnew/3 5 sys634892 Ref: 761634892 Ref: sys<5>-Footnote-1635542 Ref: sys<5>-Footnote-2635585 Node: sysconfig635628 Ref: whatsnew/3 5 sysconfig635727 Ref: 764635727 Ref: sysconfig-Footnote-1635960 Node: tarfile<2>636003 Ref: whatsnew/3 5 tarfile636108 Ref: 765636108 Ref: tarfile<2>-Footnote-1637019 Ref: 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unittest<3>640763 Ref: whatsnew/3 5 unittest640878 Ref: 77f640878 Ref: unittest<3>-Footnote-1641672 Ref: unittest<3>-Footnote-2641715 Ref: unittest<3>-Footnote-3641758 Node: unittest mock<3>641801 Ref: whatsnew/3 5 unittest-mock641908 Ref: 783641908 Ref: unittest mock<3>-Footnote-1642849 Ref: unittest mock<3>-Footnote-2642892 Ref: unittest mock<3>-Footnote-3642935 Ref: unittest mock<3>-Footnote-4642978 Ref: unittest mock<3>-Footnote-5643021 Ref: unittest mock<3>-Footnote-6643064 Node: urllib643107 Ref: whatsnew/3 5 urllib643210 Ref: 789643210 Ref: urllib-Footnote-1644370 Ref: urllib-Footnote-2644413 Ref: urllib-Footnote-3644455 Ref: urllib-Footnote-4644498 Ref: urllib-Footnote-5644541 Ref: urllib-Footnote-6644590 Ref: urllib-Footnote-7644639 Ref: urllib-Footnote-8644688 Node: wsgiref644731 Ref: whatsnew/3 5 wsgiref644827 Ref: 78e644827 Ref: wsgiref-Footnote-1645065 Node: xmlrpc<2>645107 Ref: whatsnew/3 5 xmlrpc645204 Ref: 790645204 Ref: xmlrpc<2>-Footnote-1645574 Ref: xmlrpc<2>-Footnote-2645617 Node: xml sax645660 Ref: whatsnew/3 5 xml-sax645760 Ref: 791645760 Ref: xml sax-Footnote-1646093 Ref: xml sax-Footnote-2646135 Node: zipfile<3>646178 Ref: whatsnew/3 5 zipfile646260 Ref: 794646260 Ref: zipfile<3>-Footnote-1646600 Ref: zipfile<3>-Footnote-2646643 Node: Other module-level changes646686 Ref: whatsnew/3 5 other-module-level-changes646828 Ref: 795646828 Ref: Other module-level changes-Footnote-1647159 Node: Optimizations<4>647202 Ref: whatsnew/3 5 optimizations647351 Ref: 796647351 Ref: Optimizations<4>-Footnote-1650408 Ref: Optimizations<4>-Footnote-2650451 Ref: Optimizations<4>-Footnote-3650494 Ref: Optimizations<4>-Footnote-4650537 Ref: Optimizations<4>-Footnote-5650580 Ref: Optimizations<4>-Footnote-6650623 Ref: Optimizations<4>-Footnote-7650666 Ref: Optimizations<4>-Footnote-8650709 Ref: Optimizations<4>-Footnote-9650752 Ref: Optimizations<4>-Footnote-10650795 Ref: Optimizations<4>-Footnote-11650839 Ref: Optimizations<4>-Footnote-12650883 Ref: Optimizations<4>-Footnote-13650927 Ref: Optimizations<4>-Footnote-14650971 Ref: Optimizations<4>-Footnote-15651015 Ref: Optimizations<4>-Footnote-16651059 Ref: Optimizations<4>-Footnote-17651103 Ref: Optimizations<4>-Footnote-18651147 Ref: Optimizations<4>-Footnote-19651191 Ref: Optimizations<4>-Footnote-20651235 Node: Build and C API Changes<3>651279 Ref: whatsnew/3 5 build-and-c-api-changes651415 Ref: 7a4651415 Ref: Build and C API Changes<3>-Footnote-1654965 Ref: Build and C API Changes<3>-Footnote-2655008 Ref: Build and C API Changes<3>-Footnote-3655051 Ref: Build and C API Changes<3>-Footnote-4655094 Ref: Build and C API Changes<3>-Footnote-5655137 Ref: Build and C API Changes<3>-Footnote-6655180 Ref: Build and C API Changes<3>-Footnote-7655229 Ref: Build and C API Changes<3>-Footnote-8655272 Ref: Build and C API Changes<3>-Footnote-9655315 Ref: Build and C API Changes<3>-Footnote-10655364 Node: Deprecated<3>655403 Ref: whatsnew/3 5 deprecated655533 Ref: 7b0655533 Node: New 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functions and methods<3>-Footnote-7660591 Ref: Deprecated Python modules functions and methods<3>-Footnote-8660634 Node: Removed<2>660677 Ref: whatsnew/3 5 removed660802 Ref: 7ba660802 Node: API and Feature Removals<4>660900 Ref: whatsnew/3 5 api-and-feature-removals660974 Ref: 7bb660974 Ref: API and Feature Removals<4>-Footnote-1661831 Ref: API and Feature Removals<4>-Footnote-2661873 Node: Porting to Python 3 5661916 Ref: whatsnew/3 5 porting-to-python-3-5662059 Ref: 7bc662059 Node: Changes in Python behavior<2>662404 Ref: whatsnew/3 5 changes-in-python-behavior662528 Ref: 7bd662528 Node: Changes in the Python API<4>662938 Ref: whatsnew/3 5 changes-in-the-python-api663094 Ref: 7be663094 Ref: Changes in the Python API<4>-Footnote-1670020 Ref: Changes in the Python API<4>-Footnote-2670069 Ref: Changes in the Python API<4>-Footnote-3670112 Ref: Changes in the Python API<4>-Footnote-4670155 Ref: Changes in the Python API<4>-Footnote-5670198 Ref: Changes in the Python API<4>-Footnote-6670241 Ref: Changes in the Python API<4>-Footnote-7670284 Ref: Changes in the Python API<4>-Footnote-8670327 Ref: Changes in the Python API<4>-Footnote-9670370 Ref: Changes in the Python API<4>-Footnote-10670413 Ref: Changes in the Python API<4>-Footnote-11670457 Ref: Changes in the Python API<4>-Footnote-12670501 Ref: Changes in the Python API<4>-Footnote-13670544 Ref: Changes in the Python API<4>-Footnote-14670594 Ref: Changes in the Python API<4>-Footnote-15670644 Ref: Changes in the Python API<4>-Footnote-16670688 Ref: Changes in the Python API<4>-Footnote-17670732 Ref: Changes in the Python API<4>-Footnote-18670776 Node: Changes in the C API<4>670819 Ref: whatsnew/3 5 changes-in-the-c-api670937 Ref: 7c9670937 Ref: Changes in the C API<4>-Footnote-1672209 Ref: Changes in the C API<4>-Footnote-2672252 Ref: Changes in the C API<4>-Footnote-3672295 Node: Notable changes in Python 3 5 4672344 Ref: whatsnew/3 5 notable-changes-in-python-3-5-4672468 Ref: 7ce672468 Node: New make regen-all build target<2>672705 Ref: whatsnew/3 5 new-make-regen-all-build-target672853 Ref: 7cf672853 Ref: New make regen-all build target<2>-Footnote-1673640 Ref: New make regen-all build target<2>-Footnote-2673707 Node: Removal of make touch build target<2>673750 Ref: whatsnew/3 5 removal-of-make-touch-build-target673898 Ref: 7d0673898 Ref: Removal of make touch build target<2>-Footnote-1674328 Node: What’s New In Python 3 4674371 Ref: whatsnew/3 4 doc674526 Ref: 7d1674526 Ref: whatsnew/3 4 what-s-new-in-python-3-4674526 Ref: 7d2674526 Ref: What’s New In Python 3 4-Footnote-1675260 Ref: What’s New In Python 3 4-Footnote-2675320 Node: Summary – Release Highlights<2>675369 Ref: whatsnew/3 4 summary-release-highlights675489 Ref: 7d3675489 Ref: Summary – Release Highlights<2>-Footnote-1679785 Ref: Summary – Release Highlights<2>-Footnote-2679834 Ref: Summary – Release Highlights<2>-Footnote-3679883 Ref: Summary – Release Highlights<2>-Footnote-4679926 Ref: Summary – Release Highlights<2>-Footnote-5679975 Ref: Summary – Release Highlights<2>-Footnote-6680018 Ref: Summary – Release Highlights<2>-Footnote-7680067 Ref: Summary – Release Highlights<2>-Footnote-8680116 Ref: Summary – Release Highlights<2>-Footnote-9680165 Ref: Summary – Release Highlights<2>-Footnote-10680214 Ref: Summary – Release Highlights<2>-Footnote-11680264 Ref: Summary – Release Highlights<2>-Footnote-12680314 Ref: Summary – Release Highlights<2>-Footnote-13680364 Ref: Summary – Release Highlights<2>-Footnote-14680414 Ref: Summary – Release Highlights<2>-Footnote-15680464 Ref: Summary – Release Highlights<2>-Footnote-16680507 Ref: Summary – Release Highlights<2>-Footnote-17680551 Ref: Summary – Release Highlights<2>-Footnote-18680601 Ref: Summary – Release Highlights<2>-Footnote-19680651 Ref: Summary – Release Highlights<2>-Footnote-20680695 Ref: Summary – Release Highlights<2>-Footnote-21680741 Ref: Summary – Release Highlights<2>-Footnote-22680791 Ref: Summary – Release Highlights<2>-Footnote-23680841 Ref: Summary – Release Highlights<2>-Footnote-24680885 Ref: Summary – Release Highlights<2>-Footnote-25680935 Node: New Features<5>680985 Ref: whatsnew/3 4 new-features681128 Ref: 7ef681128 Node: PEP 453 Explicit Bootstrapping of PIP in Python Installations681618 Ref: whatsnew/3 4 pep-453-explicit-bootstrapping-of-pip-in-python-installations681798 Ref: 7f0681798 Ref: whatsnew/3 4 whatsnew-pep-453681798 Ref: 7d4681798 Node: Bootstrapping pip By Default682010 Ref: whatsnew/3 4 bootstrapping-pip-by-default682166 Ref: 7f1682166 Ref: Bootstrapping pip By Default-Footnote-1685066 Ref: Bootstrapping pip By Default-Footnote-2685115 Node: Documentation Changes685210 Ref: whatsnew/3 4 documentation-changes685366 Ref: 7f4685366 Ref: Documentation Changes-Footnote-1686317 Ref: Documentation Changes-Footnote-2686354 Node: PEP 446 Newly Created File Descriptors Are Non-Inheritable686403 Ref: whatsnew/3 4 pep-446-newly-created-file-descriptors-are-non-inheritable686622 Ref: 7f9686622 Ref: whatsnew/3 4 whatsnew-pep-446686622 Ref: 7d5686622 Ref: PEP 446 Newly Created File Descriptors Are Non-Inheritable-Footnote-1687640 Ref: PEP 446 Newly Created File Descriptors Are Non-Inheritable-Footnote-2687689 Node: Improvements to Codec Handling687738 Ref: whatsnew/3 4 codec-handling-improvements687943 Ref: 7d7687943 Ref: whatsnew/3 4 improvements-to-codec-handling687943 Ref: 801687943 Ref: Improvements to Codec Handling-Footnote-1692149 Ref: Improvements to Codec Handling-Footnote-2692191 Ref: Improvements to Codec Handling-Footnote-3692234 Ref: Improvements to Codec Handling-Footnote-4692277 Node: PEP 451 A ModuleSpec Type for the Import System692320 Ref: whatsnew/3 4 pep-451-a-modulespec-type-for-the-import-system692492 Ref: 806692492 Ref: whatsnew/3 4 whatsnew-pep-451692492 Ref: 7d8692492 Ref: PEP 451 A ModuleSpec Type for the Import System-Footnote-1693443 Ref: PEP 451 A ModuleSpec Type for the Import System-Footnote-2693492 Node: Other Language Changes<5>693572 Ref: whatsnew/3 4 other-language-changes693705 Ref: 808693705 Ref: Other Language Changes<5>-Footnote-1696342 Ref: Other Language Changes<5>-Footnote-2696385 Ref: Other Language Changes<5>-Footnote-3696428 Ref: Other Language Changes<5>-Footnote-4696471 Ref: Other Language Changes<5>-Footnote-5696516 Ref: Other Language Changes<5>-Footnote-6696559 Ref: Other Language Changes<5>-Footnote-7696602 Ref: Other Language Changes<5>-Footnote-8696645 Ref: Other Language Changes<5>-Footnote-9696688 Ref: Other Language Changes<5>-Footnote-10696731 Ref: Other Language Changes<5>-Footnote-11696775 Ref: Other Language Changes<5>-Footnote-12696825 Node: New Modules<5>696869 Ref: whatsnew/3 4 new-modules696998 Ref: 80d696998 Node: asyncio<6>697209 Ref: whatsnew/3 4 asyncio697288 Ref: 80e697288 Ref: whatsnew/3 4 whatsnew-asyncio697288 Ref: 7da697288 Ref: asyncio<6>-Footnote-1697886 Ref: asyncio<6>-Footnote-2697935 Node: ensurepip697984 Ref: whatsnew/3 4 ensurepip698079 Ref: 80f698079 Ref: whatsnew/3 4 whatsnew-ensurepip698079 Ref: 7db698079 Ref: ensurepip-Footnote-1699351 Node: enum<5>699400 Ref: whatsnew/3 4 enum699495 Ref: 810699495 Ref: whatsnew/3 4 whatsnew-enum699495 Ref: 7dc699495 Ref: enum<5>-Footnote-1700065 Ref: enum<5>-Footnote-2700114 Node: pathlib<5>700163 Ref: whatsnew/3 4 pathlib700261 Ref: 811700261 Ref: whatsnew/3 4 whatsnew-pathlib700261 Ref: 7dd700261 Ref: pathlib<5>-Footnote-1700879 Node: selectors<2>700928 Ref: whatsnew/3 4 selectors701032 Ref: 812701032 Ref: whatsnew/3 4 whatsnew-selectors701032 Ref: 7de701032 Ref: selectors<2>-Footnote-1701290 Node: statistics<3>701339 Ref: whatsnew/3 4 statistics701447 Ref: 813701447 Ref: whatsnew/3 4 whatsnew-statistics701447 Ref: 7df701447 Ref: statistics<3>-Footnote-1701912 Ref: statistics<3>-Footnote-2701961 Node: tracemalloc<3>702010 Ref: whatsnew/3 4 tracemalloc702097 Ref: 814702097 Ref: whatsnew/3 4 whatsnew-tracemalloc702097 Ref: 7e0702097 Ref: tracemalloc<3>-Footnote-1702762 Ref: tracemalloc<3>-Footnote-2702811 Node: Improved Modules<5>702860 Ref: whatsnew/3 4 improved-modules703004 Ref: 815703004 Node: abc704316 Ref: whatsnew/3 4 abc704391 Ref: 816704391 Ref: abc-Footnote-1704912 Ref: abc-Footnote-2704955 Node: aifc<2>704998 Ref: whatsnew/3 4 aifc705093 Ref: 81a705093 Ref: aifc<2>-Footnote-1705731 Ref: aifc<2>-Footnote-2705774 Ref: aifc<2>-Footnote-3705817 Node: argparse<3>705859 Ref: whatsnew/3 4 argparse705958 Ref: 81f705958 Ref: argparse<3>-Footnote-1706204 Node: audioop706247 Ref: whatsnew/3 4 audioop706345 Ref: 821706345 Ref: audioop-Footnote-1706884 Ref: audioop-Footnote-2706927 Ref: audioop-Footnote-3706970 Node: base64707013 Ref: whatsnew/3 4 base64707114 Ref: 823707114 Ref: base64-Footnote-1707945 Ref: base64-Footnote-2707988 Node: collections<6>708031 Ref: whatsnew/3 4 collections708133 Ref: 828708133 Ref: collections<6>-Footnote-1708463 Node: colorsys708506 Ref: whatsnew/3 4 colorsys708615 Ref: 82a708615 Ref: colorsys-Footnote-1708983 Node: contextlib<4>709026 Ref: whatsnew/3 4 contextlib709127 Ref: 82b709127 Ref: contextlib<4>-Footnote-1710312 Ref: contextlib<4>-Footnote-2710355 Ref: contextlib<4>-Footnote-3710398 Node: dbm<5>710441 Ref: whatsnew/3 4 dbm710540 Ref: 82f710540 Ref: dbm<5>-Footnote-1710887 Node: dis<2>710930 Ref: whatsnew/3 4 dis711026 Ref: 831711026 Ref: dis<2>-Footnote-1713625 Ref: dis<2>-Footnote-2713668 Ref: dis<2>-Footnote-3713711 Node: doctest<2>713754 Ref: whatsnew/3 4 doctest713852 Ref: 83b713852 Ref: doctest<2>-Footnote-1714620 Ref: doctest<2>-Footnote-2714663 Ref: doctest<2>-Footnote-3714706 Node: email<3>714748 Ref: whatsnew/3 4 email714847 Ref: 83e714847 Ref: whatsnew/3 4 whatsnew-email-contentmanager716095 Ref: 7e4716095 Ref: email<3>-Footnote-1717024 Ref: email<3>-Footnote-2717067 Ref: email<3>-Footnote-3717110 Ref: email<3>-Footnote-4717153 Node: filecmp717196 Ref: whatsnew/3 4 filecmp717297 Ref: 846717297 Ref: filecmp-Footnote-1718043 Ref: filecmp-Footnote-2718086 Node: functools<4>718129 Ref: whatsnew/3 4 functools718227 Ref: 84a718227 Ref: whatsnew/3 4 whatsnew-singledispatch718674 Ref: 7e1718674 Ref: functools<4>-Footnote-1719633 Ref: functools<4>-Footnote-2719675 Ref: functools<4>-Footnote-3719724 Ref: functools<4>-Footnote-4719767 Node: gc<3>719810 Ref: whatsnew/3 4 gc719908 Ref: 84d719908 Ref: gc<3>-Footnote-1720174 Node: glob<2>720217 Ref: whatsnew/3 4 glob720313 Ref: 84f720313 Ref: glob<2>-Footnote-1720617 Node: hashlib<2>720659 Ref: whatsnew/3 4 hashlib720757 Ref: 851720757 Ref: hashlib<2>-Footnote-1721390 Ref: hashlib<2>-Footnote-2721435 Ref: hashlib<2>-Footnote-3721478 Node: hmac<2>721521 Ref: whatsnew/3 4 hmac721616 Ref: 853721616 Ref: hmac<2>-Footnote-1722642 Ref: hmac<2>-Footnote-2722685 Ref: hmac<2>-Footnote-3722728 Ref: hmac<2>-Footnote-4722777 Node: html722820 Ref: whatsnew/3 4 html722912 Ref: 859722912 Ref: html-Footnote-1723669 Ref: html-Footnote-2723711 Ref: html-Footnote-3723754 Node: http<2>723797 Ref: whatsnew/3 4 http723901 Ref: 85b723901 Ref: http<2>-Footnote-1724542 Ref: http<2>-Footnote-2724585 Node: idlelib and IDLE<4>724628 Ref: whatsnew/3 4 idlelib-and-idle724740 Ref: 85e724740 Node: importlib<6>725134 Ref: whatsnew/3 4 importlib725249 Ref: 85f725249 Ref: importlib<6>-Footnote-1727250 Ref: importlib<6>-Footnote-2727293 Ref: importlib<6>-Footnote-3727336 Ref: importlib<6>-Footnote-4727379 Ref: importlib<6>-Footnote-5727422 Ref: importlib<6>-Footnote-6727465 Ref: importlib<6>-Footnote-7727508 Node: inspect<4>727551 Ref: whatsnew/3 4 inspect727659 Ref: 867727659 Ref: inspect<4>-Footnote-1729373 Ref: inspect<4>-Footnote-2729416 Ref: inspect<4>-Footnote-3729459 Ref: inspect<4>-Footnote-4729502 Ref: inspect<4>-Footnote-5729545 Ref: inspect<4>-Footnote-6729588 Node: ipaddress<3>729631 Ref: whatsnew/3 4 ipaddress729737 Ref: 86b729737 Ref: ipaddress<3>-Footnote-1730263 Node: logging<5>730306 Ref: whatsnew/3 4 logging730409 Ref: 86d730409 Ref: logging<5>-Footnote-1731539 Ref: logging<5>-Footnote-2731581 Ref: logging<5>-Footnote-3731624 Node: marshal731667 Ref: whatsnew/3 4 marshal731765 Ref: 873731765 Ref: whatsnew/3 4 whatsnew-marshal-3731765 Ref: 7d9731765 Ref: marshal-Footnote-1732444 Ref: marshal-Footnote-2732487 Node: mmap<2>732530 Ref: whatsnew/3 4 mmap732636 Ref: 874732636 Ref: mmap<2>-Footnote-1732799 Node: multiprocessing<5>732841 Ref: whatsnew/3 4 multiprocessing732951 Ref: 875732951 Ref: whatsnew/3 4 whatsnew-multiprocessing-no-fork733002 Ref: 7e3733002 Ref: multiprocessing<5>-Footnote-1734814 Ref: multiprocessing<5>-Footnote-2734856 Ref: multiprocessing<5>-Footnote-3734899 Ref: multiprocessing<5>-Footnote-4734941 Node: operator<2>734984 Ref: whatsnew/3 4 operator735092 Ref: 87c735092 Ref: operator<2>-Footnote-1735643 Ref: operator<2>-Footnote-2735692 Ref: operator<2>-Footnote-3735735 Node: os<6>735778 Ref: whatsnew/3 4 os735874 Ref: 87e735874 Ref: os<6>-Footnote-1737319 Ref: os<6>-Footnote-2737362 Ref: os<6>-Footnote-3737405 Ref: os<6>-Footnote-4737447 Node: pdb<3>737490 Ref: whatsnew/3 4 pdb737584 Ref: 885737584 Ref: pdb<3>-Footnote-1738578 Ref: pdb<3>-Footnote-2738621 Node: pickle<4>738664 Ref: whatsnew/3 4 pickle738764 Ref: 888738764 Ref: whatsnew/3 4 whatsnew-protocol-4738764 Ref: 7e2738764 Ref: pickle<4>-Footnote-1739359 Node: plistlib<2>739408 Ref: whatsnew/3 4 plistlib739511 Ref: 88a739511 Ref: plistlib<2>-Footnote-1740045 Node: poplib<2>740088 Ref: whatsnew/3 4 poplib740191 Ref: 891740191 Ref: poplib<2>-Footnote-1740579 Node: pprint<2>740621 Ref: whatsnew/3 4 pprint740716 Ref: 894740716 Ref: pprint<2>-Footnote-1741334 Ref: pprint<2>-Footnote-2741377 Node: pty741420 Ref: whatsnew/3 4 pty741514 Ref: 897741514 Node: pydoc<3>741705 Ref: whatsnew/3 4 pydoc741795 Ref: 899741795 Ref: pydoc<3>-Footnote-1742850 Ref: pydoc<3>-Footnote-2742893 Node: re<5>742936 Ref: whatsnew/3 4 re743031 Ref: 89a743031 Ref: re<5>-Footnote-1743772 Ref: re<5>-Footnote-2743815 Ref: re<5>-Footnote-3743858 Node: resource743901 Ref: whatsnew/3 4 resource743994 Ref: 89e743994 Ref: resource-Footnote-1744845 Ref: resource-Footnote-2744888 Ref: resource-Footnote-3744931 Node: select744974 Ref: whatsnew/3 4 select745068 Ref: 8a8745068 Ref: select-Footnote-1745575 Ref: select-Footnote-2745618 Node: shelve745661 Ref: whatsnew/3 4 shelve745756 Ref: 8af745756 Ref: shelve-Footnote-1746026 Node: shutil<3>746069 Ref: whatsnew/3 4 shutil746166 Ref: 8b1746166 Ref: shutil<3>-Footnote-1746537 Node: smtpd<2>746582 Ref: whatsnew/3 4 smtpd746683 Ref: 8b4746683 Ref: smtpd<2>-Footnote-1747059 Node: smtplib<2>747102 Ref: whatsnew/3 4 smtplib747203 Ref: 8b6747203 Ref: smtplib<2>-Footnote-1747563 Node: socket<6>747605 Ref: whatsnew/3 4 socket747708 Ref: 8b8747708 Ref: socket<6>-Footnote-1748489 Ref: socket<6>-Footnote-2748532 Node: sqlite3<4>748574 Ref: whatsnew/3 4 sqlite3748673 Ref: 8bd748673 Ref: sqlite3<4>-Footnote-1748962 Ref: sqlite3<4>-Footnote-2749002 Node: ssl<7>749045 Ref: whatsnew/3 4 ssl749139 Ref: 8be749139 Ref: whatsnew/3 4 whatsnew-tls-11-12749166 Ref: 7e7749166 Ref: whatsnew/3 4 whatsnew34-sslcontext749436 Ref: 7ea749436 Ref: whatsnew/3 4 whatsnew34-win-cert-store752110 Ref: 7e8752110 Ref: whatsnew/3 4 whatsnew34-sni752364 Ref: 7e9752364 Ref: ssl<7>-Footnote-1752813 Ref: ssl<7>-Footnote-2752856 Ref: ssl<7>-Footnote-3752899 Ref: ssl<7>-Footnote-4752942 Ref: ssl<7>-Footnote-5752985 Ref: ssl<7>-Footnote-6753028 Ref: ssl<7>-Footnote-7753070 Ref: ssl<7>-Footnote-8753113 Ref: ssl<7>-Footnote-9753156 Ref: ssl<7>-Footnote-10753198 Node: stat753242 Ref: whatsnew/3 4 stat753335 Ref: 8d2753335 Ref: stat-Footnote-1753806 Ref: stat-Footnote-2753849 Node: struct<2>753892 Ref: whatsnew/3 4 struct753992 Ref: 8d7753992 Ref: struct<2>-Footnote-1754322 Node: subprocess<4>754365 Ref: whatsnew/3 4 subprocess754469 Ref: 8da754469 Ref: subprocess<4>-Footnote-1754913 Ref: subprocess<4>-Footnote-2754956 Node: sunau<2>754999 Ref: whatsnew/3 4 sunau755100 Ref: 8dd755100 Ref: sunau<2>-Footnote-1755905 Ref: sunau<2>-Footnote-2755948 Ref: sunau<2>-Footnote-3755991 Ref: sunau<2>-Footnote-4756034 Node: sys<6>756076 Ref: whatsnew/3 4 sys756174 Ref: 8e1756174 Ref: sys<6>-Footnote-1757452 Ref: sys<6>-Footnote-2757495 Node: tarfile<3>757537 Ref: whatsnew/3 4 tarfile757635 Ref: 8e7757635 Ref: tarfile<3>-Footnote-1757952 Node: textwrap757995 Ref: whatsnew/3 4 textwrap758099 Ref: 8e9758099 Ref: textwrap-Footnote-1758798 Ref: textwrap-Footnote-2758841 Node: threading<4>758884 Ref: whatsnew/3 4 threading758990 Ref: 8ee758990 Ref: threading<4>-Footnote-1759333 Node: traceback<3>759376 Ref: whatsnew/3 4 traceback759482 Ref: 8f0759482 Ref: traceback<3>-Footnote-1759795 Node: types<3>759840 Ref: whatsnew/3 4 types759943 Ref: 8f2759943 Ref: types<3>-Footnote-1760447 Node: urllib<2>760490 Ref: whatsnew/3 4 urllib760592 Ref: 8f4760592 Ref: urllib<2>-Footnote-1761906 Ref: urllib<2>-Footnote-2761949 Ref: urllib<2>-Footnote-3761992 Ref: urllib<2>-Footnote-4762035 Ref: urllib<2>-Footnote-5762078 Ref: urllib<2>-Footnote-6762121 Node: unittest<4>762164 Ref: whatsnew/3 4 unittest762265 Ref: 8fe762265 Ref: unittest<4>-Footnote-1765419 Ref: unittest<4>-Footnote-2765462 Ref: unittest<4>-Footnote-3765505 Ref: unittest<4>-Footnote-4765548 Ref: unittest<4>-Footnote-5765591 Ref: unittest<4>-Footnote-6765634 Ref: unittest<4>-Footnote-7765677 Ref: unittest<4>-Footnote-8765720 Ref: unittest<4>-Footnote-9765763 Node: venv<4>765806 Ref: whatsnew/3 4 venv765905 Ref: 907765905 Ref: venv<4>-Footnote-1766461 Ref: venv<4>-Footnote-2766504 Ref: venv<4>-Footnote-3766547 Node: wave<2>766596 Ref: whatsnew/3 4 wave766694 Ref: 90a766694 Ref: wave<2>-Footnote-1767329 Ref: wave<2>-Footnote-2767372 Ref: wave<2>-Footnote-3767415 Ref: wave<2>-Footnote-4767457 Node: weakref<2>767499 Ref: whatsnew/3 4 weakref767602 Ref: 90e767602 Ref: weakref<2>-Footnote-1768221 Ref: weakref<2>-Footnote-2768264 Ref: weakref<2>-Footnote-3768307 Node: xml etree<2>768350 Ref: whatsnew/3 4 xml-etree768456 Ref: 912768456 Ref: xml etree<2>-Footnote-1769193 Ref: xml etree<2>-Footnote-2769236 Node: zipfile<4>769279 Ref: whatsnew/3 4 zipfile769366 Ref: 919769366 Ref: zipfile<4>-Footnote-1769895 Ref: zipfile<4>-Footnote-2769938 Node: CPython Implementation Changes769981 Ref: whatsnew/3 4 cpython-implementation-changes770124 Ref: 91c770124 Node: PEP 445 Customization of CPython Memory Allocators770654 Ref: whatsnew/3 4 pep-445-customization-of-cpython-memory-allocators770812 Ref: 91d770812 Ref: whatsnew/3 4 whatsnew-pep-445770812 Ref: 7ed770812 Ref: PEP 445 Customization of CPython Memory Allocators-Footnote-1771207 Ref: PEP 445 Customization of CPython Memory Allocators-Footnote-2771256 Node: PEP 442 Safe Object Finalization771305 Ref: whatsnew/3 4 pep-442-safe-object-finalization771521 Ref: 91e771521 Ref: whatsnew/3 4 whatsnew-pep-442771521 Ref: 7ec771521 Ref: PEP 442 Safe Object Finalization-Footnote-1772388 Ref: PEP 442 Safe Object Finalization-Footnote-2772437 Node: PEP 456 Secure and Interchangeable Hash Algorithm772486 Ref: whatsnew/3 4 pep-456-secure-and-interchangeable-hash-algorithm772675 Ref: 920772675 Ref: whatsnew/3 4 whatsnew-pep-456772675 Ref: 7e5772675 Ref: PEP 456 Secure and Interchangeable Hash Algorithm-Footnote-1773621 Ref: PEP 456 Secure and Interchangeable Hash Algorithm-Footnote-2773670 Node: PEP 436 Argument Clinic773713 Ref: whatsnew/3 4 pep-436-argument-clinic773899 Ref: 922773899 Ref: whatsnew/3 4 whatsnew-pep-436773899 Ref: 7ee773899 Ref: PEP 436 Argument Clinic-Footnote-1775005 Ref: PEP 436 Argument Clinic-Footnote-2775054 Node: Other Build and C API Changes775103 Ref: whatsnew/3 4 other-build-and-c-api-changes775261 Ref: 923775261 Ref: Other Build and C API Changes-Footnote-1777345 Ref: Other Build and C API Changes-Footnote-2777388 Ref: Other Build and C API Changes-Footnote-3777431 Ref: Other Build and C API Changes-Footnote-4777476 Ref: Other Build and C API Changes-Footnote-5777518 Ref: Other Build and C API Changes-Footnote-6777561 Ref: Other Build and C API Changes-Footnote-7777634 Ref: Other Build and C API Changes-Footnote-8777698 Ref: Other Build and C API Changes-Footnote-9777741 Node: Other Improvements<2>777784 Ref: whatsnew/3 4 other-improvements777944 Ref: 929777944 Ref: whatsnew/3 4 other-improvements-3-4777944 Ref: 92a777944 Ref: whatsnew/3 4 whatsnew-isolated-mode777999 Ref: 7d6777999 Ref: Other Improvements<2>-Footnote-1782124 Ref: Other Improvements<2>-Footnote-2782167 Ref: Other Improvements<2>-Footnote-3782209 Ref: Other Improvements<2>-Footnote-4782252 Ref: Other Improvements<2>-Footnote-5782295 Ref: Other Improvements<2>-Footnote-6782338 Ref: Other Improvements<2>-Footnote-7782381 Ref: Other Improvements<2>-Footnote-8782476 Ref: Other Improvements<2>-Footnote-9782529 Ref: Other Improvements<2>-Footnote-10782572 Ref: Other Improvements<2>-Footnote-11782616 Ref: Other Improvements<2>-Footnote-12782660 Ref: Other Improvements<2>-Footnote-13782710 Ref: Other Improvements<2>-Footnote-14782754 Ref: Other Improvements<2>-Footnote-15782798 Ref: Other Improvements<2>-Footnote-16782842 Ref: Other Improvements<2>-Footnote-17782886 Ref: Other Improvements<2>-Footnote-18782936 Ref: Other Improvements<2>-Footnote-19782980 Ref: Other Improvements<2>-Footnote-20783024 Ref: Other Improvements<2>-Footnote-21783068 Node: Significant Optimizations783112 Ref: whatsnew/3 4 significant-optimizations783234 Ref: 930783234 Ref: Significant Optimizations-Footnote-1786037 Ref: Significant Optimizations-Footnote-2786080 Ref: Significant Optimizations-Footnote-3786123 Ref: Significant Optimizations-Footnote-4786166 Ref: Significant Optimizations-Footnote-5786209 Ref: Significant Optimizations-Footnote-6786252 Ref: Significant Optimizations-Footnote-7786295 Ref: Significant Optimizations-Footnote-8786337 Ref: Significant Optimizations-Footnote-9786380 Ref: Significant Optimizations-Footnote-10786423 Ref: Significant Optimizations-Footnote-11786467 Ref: Significant Optimizations-Footnote-12786511 Ref: Significant Optimizations-Footnote-13786555 Node: Deprecated<4>786599 Ref: whatsnew/3 4 deprecated786733 Ref: 935786733 Ref: whatsnew/3 4 deprecated-3-4786733 Ref: 807786733 Node: Deprecations in the Python API787173 Ref: whatsnew/3 4 deprecations-in-the-python-api787281 Ref: 936787281 Node: Deprecated Features791043 Ref: whatsnew/3 4 deprecated-features791151 Ref: 949791151 Ref: Deprecated Features-Footnote-1791534 Ref: Deprecated Features-Footnote-2791577 Node: Removed<3>791620 Ref: whatsnew/3 4 removed791745 Ref: 94b791745 Node: Operating Systems No Longer Supported791901 Ref: whatsnew/3 4 operating-systems-no-longer-supported792021 Ref: 94c792021 Ref: Operating Systems No Longer Supported-Footnote-1792434 Ref: Operating Systems No Longer Supported-Footnote-2792477 Ref: Operating Systems No Longer Supported-Footnote-3792520 Node: API and Feature Removals<5>792563 Ref: whatsnew/3 4 api-and-feature-removals792705 Ref: 94d792705 Ref: API and Feature Removals<5>-Footnote-1795159 Ref: API and Feature Removals<5>-Footnote-2795195 Ref: API and Feature Removals<5>-Footnote-3795238 Ref: API and Feature Removals<5>-Footnote-4795281 Ref: API and Feature Removals<5>-Footnote-5795324 Ref: API and Feature Removals<5>-Footnote-6795367 Ref: API and Feature Removals<5>-Footnote-7795409 Node: Code Cleanups795452 Ref: whatsnew/3 4 code-cleanups795548 Ref: 950795548 Ref: Code Cleanups-Footnote-1796211 Node: Porting to Python 3 4796254 Ref: whatsnew/3 4 porting-to-python-3-4796382 Ref: 951796382 Node: Changes in ‘python’ Command Behavior<2>796753 Ref: whatsnew/3 4 changes-in-python-command-behavior796891 Ref: 952796891 Ref: Changes in ‘python’ Command Behavior<2>-Footnote-1798002 Node: Changes in the Python API<5>798045 Ref: whatsnew/3 4 changes-in-the-python-api798215 Ref: 954798215 Ref: Changes in the Python API<5>-Footnote-1811597 Ref: Changes in the Python API<5>-Footnote-2811640 Ref: Changes in the Python API<5>-Footnote-3811683 Ref: Changes in the Python API<5>-Footnote-4811726 Ref: Changes in the Python API<5>-Footnote-5811769 Ref: Changes in the Python API<5>-Footnote-6811812 Ref: Changes in the Python API<5>-Footnote-7811855 Ref: Changes in the Python API<5>-Footnote-8811898 Ref: Changes in the Python API<5>-Footnote-9811940 Ref: Changes in the Python API<5>-Footnote-10811983 Ref: Changes in the Python API<5>-Footnote-11812027 Ref: Changes in the Python API<5>-Footnote-12812071 Ref: Changes in the Python API<5>-Footnote-13812115 Ref: Changes in the Python API<5>-Footnote-14812159 Ref: Changes in the Python API<5>-Footnote-15812203 Ref: Changes in the Python API<5>-Footnote-16812247 Ref: Changes in the Python API<5>-Footnote-17812291 Ref: Changes in the Python API<5>-Footnote-18812335 Ref: Changes in the Python API<5>-Footnote-19812379 Ref: Changes in the Python API<5>-Footnote-20812423 Ref: Changes in the Python API<5>-Footnote-21812467 Ref: Changes in the Python API<5>-Footnote-22812511 Ref: Changes in the Python API<5>-Footnote-23812555 Ref: Changes in the Python API<5>-Footnote-24812598 Node: Changes in the C API<5>812642 Ref: whatsnew/3 4 changes-in-the-c-api812760 Ref: 966812760 Ref: Changes in the C API<5>-Footnote-1814520 Ref: Changes in the C API<5>-Footnote-2814563 Node: Changed in 3 4 3814606 Ref: whatsnew/3 4 changed-in-3-4-3814715 Ref: 972814715 Node: PEP 476 Enabling certificate verification by default for stdlib http clients814931 Ref: whatsnew/3 4 pep-476815060 Ref: 973815060 Ref: whatsnew/3 4 pep-476-enabling-certificate-verification-by-default-for-stdlib-http-clients815060 Ref: 974815060 Node: What’s New In Python 3 3816059 Ref: whatsnew/3 3 doc816214 Ref: 975816214 Ref: whatsnew/3 3 what-s-new-in-python-3-3816214 Ref: 976816214 Ref: What’s New In Python 3 3-Footnote-1818154 Ref: What’s New In Python 3 3-Footnote-2818214 Node: Summary – Release highlights<4>818263 Ref: whatsnew/3 3 summary-release-highlights818396 Ref: 977818396 Node: PEP 405 Virtual Environments819725 Ref: whatsnew/3 3 pep-405819902 Ref: 979819902 Ref: whatsnew/3 3 pep-405-virtual-environments819902 Ref: 981819902 Ref: PEP 405 Virtual Environments-Footnote-1820890 Node: PEP 420 Implicit Namespace Packages820939 Ref: whatsnew/3 3 pep-420-implicit-namespace-packages821155 Ref: 982821155 Ref: PEP 420 Implicit Namespace Packages-Footnote-1821666 Ref: PEP 420 Implicit Namespace Packages-Footnote-2821715 Node: PEP 3118 New memoryview implementation and buffer protocol documentation821764 Ref: whatsnew/3 3 pep-3118-new-memoryview-implementation-and-buffer-protocol-documentation821990 Ref: 983821990 Ref: whatsnew/3 3 pep-3118-update821990 Ref: 984821990 Ref: PEP 3118 New memoryview implementation and buffer protocol documentation-Footnote-1823120 Node: Features823169 Ref: whatsnew/3 3 features823306 Ref: 985823306 Ref: Features-Footnote-1824106 Node: API changes824149 Ref: whatsnew/3 3 api-changes824286 Ref: 986824286 Ref: API changes-Footnote-1825301 Ref: API changes-Footnote-2825344 Node: PEP 393 Flexible String Representation825393 Ref: whatsnew/3 3 pep-393825619 Ref: 97c825619 Ref: whatsnew/3 3 pep-393-flexible-string-representation825619 Ref: 989825619 Ref: PEP 393 Flexible String Representation-Footnote-1826678 Node: Functionality826727 Ref: whatsnew/3 3 functionality826854 Ref: 98a826854 Ref: Functionality-Footnote-1828301 Ref: Functionality-Footnote-2828350 Node: Performance and resource usage828393 Ref: whatsnew/3 3 performance-and-resource-usage828520 Ref: 98c828520 Ref: Performance and resource usage-Footnote-1829751 Node: PEP 397 Python Launcher for Windows829800 Ref: whatsnew/3 3 pep-397830006 Ref: 98d830006 Ref: whatsnew/3 3 pep-397-python-launcher-for-windows830006 Ref: 98e830006 Ref: PEP 397 Python Launcher for Windows-Footnote-1831548 Ref: PEP 397 Python Launcher for Windows-Footnote-2831590 Node: PEP 3151 Reworking the OS and IO exception hierarchy831639 Ref: whatsnew/3 3 pep-3151831854 Ref: 97a831854 Ref: whatsnew/3 3 pep-3151-reworking-the-os-and-io-exception-hierarchy831854 Ref: 991831854 Ref: PEP 3151 Reworking the OS and IO exception hierarchy-Footnote-1834423 Node: PEP 380 Syntax for Delegating to a Subgenerator834472 Ref: whatsnew/3 3 pep-380834689 Ref: 978834689 Ref: whatsnew/3 3 pep-380-syntax-for-delegating-to-a-subgenerator834689 Ref: 9a1834689 Ref: PEP 380 Syntax for Delegating to a Subgenerator-Footnote-1837132 Node: PEP 409 Suppressing exception context837181 Ref: whatsnew/3 3 pep-409-suppressing-exception-context837379 Ref: 9a3837379 Ref: PEP 409 Suppressing exception context-Footnote-1839467 Node: PEP 414 Explicit Unicode literals839516 Ref: whatsnew/3 3 pep-414-explicit-unicode-literals839716 Ref: 9a4839716 Ref: PEP 414 Explicit Unicode literals-Footnote-1840429 Node: PEP 3155 Qualified name for classes and functions840478 Ref: whatsnew/3 3 pep-3155-qualified-name-for-classes-and-functions840671 Ref: 9a5840671 Ref: PEP 3155 Qualified name for classes and functions-Footnote-1842263 Node: PEP 412 Key-Sharing Dictionary842312 Ref: whatsnew/3 3 pep-412842505 Ref: 97d842505 Ref: whatsnew/3 3 pep-412-key-sharing-dictionary842505 Ref: 9a6842505 Ref: PEP 412 Key-Sharing Dictionary-Footnote-1843024 Node: PEP 362 Function Signature Object843073 Ref: whatsnew/3 3 pep-362-function-signature-object843250 Ref: 9a7843250 Ref: PEP 362 Function Signature Object-Footnote-1844144 Node: PEP 421 Adding sys implementation844193 Ref: whatsnew/3 3 pep-421-adding-sys-implementation844387 Ref: 9a9844387 Ref: PEP 421 Adding sys implementation-Footnote-1845601 Node: SimpleNamespace845650 Ref: whatsnew/3 3 simplenamespace845735 Ref: 9ab845735 Ref: SimpleNamespace-Footnote-1846353 Node: Using importlib as the Implementation of Import846402 Ref: whatsnew/3 3 importlib846588 Ref: 97b846588 Ref: whatsnew/3 3 using-importlib-as-the-implementation-of-import846588 Ref: 9ad846588 Ref: Using importlib as the Implementation of Import-Footnote-1847869 Ref: Using importlib as the Implementation of Import-Footnote-2847911 Ref: Using importlib as the Implementation of Import-Footnote-3847954 Ref: Using importlib as the Implementation of Import-Footnote-4847997 Ref: Using importlib as the Implementation of Import-Footnote-5848040 Node: New APIs848089 Ref: whatsnew/3 3 new-apis848205 Ref: 9b0848205 Node: Visible Changes850047 Ref: whatsnew/3 3 visible-changes850163 Ref: 9ba850163 Ref: Visible Changes-Footnote-1852017 Ref: Visible Changes-Footnote-2852066 Node: Other Language Changes<6>852115 Ref: whatsnew/3 3 other-language-changes852295 Ref: 9bc852295 Ref: Other Language Changes<6>-Footnote-1854255 Ref: Other Language Changes<6>-Footnote-2854298 Ref: Other Language Changes<6>-Footnote-3854341 Ref: Other Language Changes<6>-Footnote-4854384 Ref: Other Language Changes<6>-Footnote-5854427 Ref: Other Language Changes<6>-Footnote-6854470 Ref: Other Language Changes<6>-Footnote-7854513 Ref: Other Language Changes<6>-Footnote-8854556 Node: A Finer-Grained Import Lock854599 Ref: whatsnew/3 3 a-finer-grained-import-lock854759 Ref: 9c0854759 Ref: A Finer-Grained Import Lock-Footnote-1855502 Node: Builtin functions and types855544 Ref: whatsnew/3 3 builtin-functions-and-types855693 Ref: 9c2855693 Ref: Builtin functions and types-Footnote-1856926 Node: New Modules<6>856968 Ref: whatsnew/3 3 new-modules857109 Ref: 9c6857109 Node: faulthandler<3>857235 Ref: whatsnew/3 3 faulthandler857322 Ref: 9c7857322 Node: ipaddress<4>858247 Ref: whatsnew/3 3 ipaddress858350 Ref: 9c9858350 Ref: ipaddress<4>-Footnote-1858694 Node: lzma<2>858743 Ref: whatsnew/3 3 lzma858822 Ref: 9ca858822 Ref: lzma<2>-Footnote-1859134 Node: Improved Modules<6>859176 Ref: whatsnew/3 3 improved-modules859306 Ref: 9cb859306 Node: abc<2>860573 Ref: whatsnew/3 3 abc860652 Ref: 9cc860652 Ref: abc<2>-Footnote-1861684 Ref: abc<2>-Footnote-2861727 Node: array<2>861770 Ref: whatsnew/3 3 array861867 Ref: 9d2861867 Ref: array<2>-Footnote-1862105 Node: base64<2>862150 Ref: whatsnew/3 3 base64862252 Ref: 9d3862252 Ref: base64<2>-Footnote-1862550 Node: binascii<3>862593 Ref: 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gc885700 Ref: a09885700 Node: hmac<3>885872 Ref: whatsnew/3 3 hmac885965 Ref: a0b885965 Ref: hmac<3>-Footnote-1886229 Node: http<3>886272 Ref: whatsnew/3 3 http886367 Ref: a0d886367 Ref: http<3>-Footnote-1887045 Ref: http<3>-Footnote-2887087 Ref: http<3>-Footnote-3887130 Node: html<2>887173 Ref: whatsnew/3 3 html887271 Ref: a14887271 Ref: html<2>-Footnote-1888269 Ref: html<2>-Footnote-2888312 Ref: html<2>-Footnote-3888355 Ref: html<2>-Footnote-4888398 Ref: html<2>-Footnote-5888441 Ref: html<2>-Footnote-6888484 Ref: html<2>-Footnote-7888529 Ref: html<2>-Footnote-8888573 Ref: html<2>-Footnote-9888616 Ref: html<2>-Footnote-10888659 Ref: html<2>-Footnote-11888705 Ref: html<2>-Footnote-12888750 Ref: html<2>-Footnote-13888794 Ref: html<2>-Footnote-14888838 Ref: html<2>-Footnote-15888881 Ref: html<2>-Footnote-16888925 Node: imaplib<2>888969 Ref: whatsnew/3 3 imaplib889070 Ref: a16889070 Ref: imaplib<2>-Footnote-1889310 Node: inspect<5>889352 Ref: whatsnew/3 3 inspect889451 Ref: a18889451 Ref: 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Ref: os<7>-Footnote-5902473 Ref: os<7>-Footnote-6902516 Ref: os<7>-Footnote-7902558 Ref: os<7>-Footnote-8902601 Ref: os<7>-Footnote-9902644 Ref: os<7>-Footnote-10902687 Ref: os<7>-Footnote-11902730 Node: pdb<4>902774 Ref: whatsnew/3 3 pdb902868 Ref: a67902868 Ref: pdb<4>-Footnote-1903149 Node: pickle<5>903192 Ref: whatsnew/3 3 pickle903289 Ref: a68903289 Ref: pickle<5>-Footnote-1903557 Node: pydoc<4>903600 Ref: whatsnew/3 3 pydoc903696 Ref: a6a903696 Node: re<6>903893 Ref: whatsnew/3 3 re903985 Ref: a6b903985 Ref: re<6>-Footnote-1904179 Node: sched904221 Ref: whatsnew/3 3 sched904314 Ref: a6c904314 Ref: sched-Footnote-1905446 Ref: sched-Footnote-2905489 Ref: sched-Footnote-3905531 Ref: sched-Footnote-4905574 Ref: sched-Footnote-5905617 Node: select<2>905660 Ref: whatsnew/3 3 select905756 Ref: a71905756 Ref: select<2>-Footnote-1906019 Node: shlex<3>906061 Ref: whatsnew/3 3 shlex906161 Ref: a72906161 Node: shutil<4>906472 Ref: whatsnew/3 3 shutil906572 Ref: a74906572 Ref: 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sqlite3<5>913743 Ref: whatsnew/3 3 sqlite3913848 Ref: a8c913848 Ref: sqlite3<5>-Footnote-1914123 Node: ssl<8>914166 Ref: whatsnew/3 3 ssl914263 Ref: a8e914263 Ref: ssl<8>-Footnote-1916480 Ref: ssl<8>-Footnote-2916523 Ref: ssl<8>-Footnote-3916566 Ref: ssl<8>-Footnote-4916609 Ref: ssl<8>-Footnote-5916652 Ref: ssl<8>-Footnote-6916695 Ref: ssl<8>-Footnote-7916738 Ref: ssl<8>-Footnote-8916781 Ref: ssl<8>-Footnote-9916824 Ref: ssl<8>-Footnote-10916867 Ref: ssl<8>-Footnote-11916911 Node: stat<2>916955 Ref: whatsnew/3 3 stat917051 Ref: a9c917051 Ref: stat<2>-Footnote-1917346 Node: struct<3>917389 Ref: whatsnew/3 3 struct917492 Ref: a9e917492 Ref: struct<3>-Footnote-1917739 Node: subprocess<5>917781 Ref: whatsnew/3 3 subprocess917883 Ref: a9f917883 Ref: subprocess<5>-Footnote-1918218 Ref: subprocess<5>-Footnote-2918260 Node: sys<7>918302 Ref: whatsnew/3 3 sys918405 Ref: aa1918405 Ref: sys<7>-Footnote-1918623 Node: tarfile<4>918666 Ref: whatsnew/3 3 tarfile918764 Ref: aa4918764 Ref: 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Porting Python code-Footnote-1943951 Ref: Porting Python code-Footnote-2943994 Ref: Porting Python code-Footnote-3944037 Ref: Porting Python code-Footnote-4944080 Ref: Porting Python code-Footnote-5944129 Ref: Porting Python code-Footnote-6944178 Ref: Porting Python code-Footnote-7944220 Ref: Porting Python code-Footnote-8944265 Ref: Porting Python code-Footnote-9944308 Ref: Porting Python code-Footnote-10944350 Node: Porting C code944394 Ref: whatsnew/3 3 porting-c-code944524 Ref: 988944524 Ref: Porting C code-Footnote-1946016 Node: Building C extensions946065 Ref: whatsnew/3 3 building-c-extensions946203 Ref: b22946203 Ref: Building C extensions-Footnote-1946801 Node: Command Line Switch Changes946844 Ref: whatsnew/3 3 command-line-switch-changes946959 Ref: b23946959 Ref: Command Line Switch Changes-Footnote-1947524 Ref: Command Line Switch Changes-Footnote-2947567 Node: What’s New In Python 3 2947610 Ref: whatsnew/3 2 doc947765 Ref: b25947765 Ref: whatsnew/3 2 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ssl<9>-Footnote-81027702 Ref: ssl<9>-Footnote-91027744 Node: nntp1027786 Ref: whatsnew/3 2 nntp1027898 Ref: ba41027898 Ref: nntp-Footnote-11028468 Ref: nntp-Footnote-21028510 Node: certificates1028552 Ref: whatsnew/3 2 certificates1028668 Ref: ba71028668 Ref: certificates-Footnote-11029063 Node: imaplib<3>1029105 Ref: whatsnew/3 2 imaplib1029231 Ref: ba91029231 Ref: imaplib<3>-Footnote-11029502 Node: http client<4>1029544 Ref: whatsnew/3 2 http-client1029669 Ref: bab1029669 Ref: http client<4>-Footnote-11031091 Node: unittest<6>1031134 Ref: whatsnew/3 2 unittest1031258 Ref: bae1031258 Ref: unittest<6>-Footnote-11036039 Ref: unittest<6>-Footnote-21036082 Ref: unittest<6>-Footnote-31036124 Node: random<2>1036166 Ref: whatsnew/3 2 random1036285 Ref: bba1036285 Ref: random<2>-Footnote-11036947 Node: poplib<3>1036989 Ref: whatsnew/3 2 poplib1037108 Ref: bc01037108 Ref: poplib<3>-Footnote-11037460 Node: asyncore<2>1037502 Ref: whatsnew/3 2 asyncore1037623 Ref: bc21037623 Ref: asyncore<2>-Footnote-11038099 Node: tempfile<2>1038141 Ref: whatsnew/3 2 tempfile1038263 Ref: bc71038263 Ref: tempfile<2>-Footnote-11038670 Node: inspect<6>1038712 Ref: whatsnew/3 2 inspect1038831 Ref: bc91038831 Ref: inspect<6>-Footnote-11040189 Node: pydoc<5>1040232 Ref: whatsnew/3 2 pydoc1040346 Ref: bcc1040346 Ref: pydoc<5>-Footnote-11040663 Node: dis<3>1040705 Ref: whatsnew/3 2 dis1040815 Ref: bcd1040815 Ref: dis<3>-Footnote-11042963 Node: dbm<6>1043005 Ref: whatsnew/3 2 dbm1043116 Ref: bcf1043116 Ref: dbm<6>-Footnote-11043303 Node: ctypes<2>1043345 Ref: whatsnew/3 2 ctypes1043457 Ref: bd01043457 Node: site<2>1043573 Ref: whatsnew/3 2 site1043691 Ref: bd21043691 Ref: site<2>-Footnote-11044920 Node: sysconfig<2>1044962 Ref: whatsnew/3 2 sysconfig1045077 Ref: bd61045077 Node: pdb<5>1047306 Ref: whatsnew/3 2 pdb1047429 Ref: bda1047429 Node: configparser<2>1048327 Ref: whatsnew/3 2 configparser1048453 Ref: bdb1048453 Node: urllib parse<2>1051317 Ref: whatsnew/3 2 urllib-parse1051444 Ref: bdd1051444 Ref: urllib parse<2>-Footnote-11053452 Ref: urllib parse<2>-Footnote-21053495 Ref: urllib parse<2>-Footnote-31053544 Ref: urllib parse<2>-Footnote-41053586 Ref: urllib parse<2>-Footnote-51053628 Node: mailbox1053670 Ref: whatsnew/3 2 mailbox1053792 Ref: be11053792 Ref: mailbox-Footnote-11055364 Node: turtledemo1055406 Ref: whatsnew/3 2 turtledemo1055504 Ref: be81055504 Ref: turtledemo-Footnote-11055939 Node: Multi-threading1055982 Ref: whatsnew/3 2 multi-threading1056129 Ref: be91056129 Ref: Multi-threading-Footnote-11057766 Ref: Multi-threading-Footnote-21057845 Ref: Multi-threading-Footnote-31057887 Ref: Multi-threading-Footnote-41057931 Node: Optimizations<6>1057973 Ref: whatsnew/3 2 optimizations1058092 Ref: bed1058092 Ref: Optimizations<6>-Footnote-11061531 Ref: Optimizations<6>-Footnote-21061573 Ref: Optimizations<6>-Footnote-31061615 Ref: Optimizations<6>-Footnote-41061657 Ref: Optimizations<6>-Footnote-51061703 Ref: Optimizations<6>-Footnote-61061745 Ref: Optimizations<6>-Footnote-71061787 Ref: Optimizations<6>-Footnote-81061830 Ref: Optimizations<6>-Footnote-91061872 Ref: Optimizations<6>-Footnote-101061914 Ref: Optimizations<6>-Footnote-111061957 Ref: Optimizations<6>-Footnote-121062000 Ref: Optimizations<6>-Footnote-131062043 Ref: Optimizations<6>-Footnote-141062089 Ref: Optimizations<6>-Footnote-151062132 Ref: Optimizations<6>-Footnote-161062176 Node: Unicode1062219 Ref: whatsnew/3 2 unicode1062329 Ref: bf01062329 Ref: Unicode-Footnote-11062879 Ref: Unicode-Footnote-21062929 Ref: Unicode-Footnote-31062973 Node: Codecs1063044 Ref: whatsnew/3 2 codecs1063151 Ref: bf11063151 Ref: Codecs-Footnote-11064080 Node: Documentation1064125 Ref: whatsnew/3 2 documentation1064229 Ref: bf21064229 Ref: Documentation-Footnote-11065873 Ref: Documentation-Footnote-21065941 Ref: Documentation-Footnote-31066017 Ref: Documentation-Footnote-41066059 Node: IDLE1066101 Ref: whatsnew/3 2 idle1066214 Ref: bf61066214 Ref: IDLE-Footnote-11066598 Ref: IDLE-Footnote-21066640 Node: Code Repository1066682 Ref: whatsnew/3 2 code-repository1066808 Ref: bf71066808 Ref: Code Repository-Footnote-11067414 Ref: Code Repository-Footnote-21067453 Ref: Code Repository-Footnote-31067502 Ref: Code Repository-Footnote-41067556 Node: Build and C API Changes<5>1067600 Ref: whatsnew/3 2 build-and-c-api-changes1067743 Ref: bf81067743 Ref: Build and C API Changes<5>-Footnote-11071880 Ref: Build and C API Changes<5>-Footnote-21071923 Ref: Build and C API Changes<5>-Footnote-31071965 Ref: Build and C API Changes<5>-Footnote-41072007 Ref: Build and C API Changes<5>-Footnote-51072049 Ref: Build and C API Changes<5>-Footnote-61072091 Ref: Build and C API Changes<5>-Footnote-71072133 Ref: Build and C API Changes<5>-Footnote-81072175 Ref: Build and C API Changes<5>-Footnote-91072217 Ref: Build and C API Changes<5>-Footnote-101072259 Ref: Build and C API Changes<5>-Footnote-111072302 Ref: Build and C API Changes<5>-Footnote-121072345 Ref: Build and C API Changes<5>-Footnote-131072388 Ref: Build and C API Changes<5>-Footnote-141072450 Ref: Build and C API Changes<5>-Footnote-151072530 Node: Porting to Python 3 21072587 Ref: whatsnew/3 2 porting-to-python-3-21072706 Ref: c011072706 Ref: Porting to Python 3 2-Footnote-11079549 Ref: Porting to Python 3 2-Footnote-21079591 Ref: Porting to Python 3 2-Footnote-31079633 Ref: Porting to Python 3 2-Footnote-41079678 Ref: Porting to Python 3 2-Footnote-51079721 Ref: Porting to Python 3 2-Footnote-61079764 Ref: Porting to Python 3 2-Footnote-71079807 Node: What’s New In Python 3 11079849 Ref: whatsnew/3 1 doc1080004 Ref: c131080004 Ref: whatsnew/3 1 what-s-new-in-python-3-11080004 Ref: c141080004 Node: PEP 372 Ordered Dictionaries1080630 Ref: whatsnew/3 1 pep-372-ordered-dictionaries1080778 Ref: c151080778 Ref: PEP 372 Ordered Dictionaries-Footnote-11082327 Ref: PEP 372 Ordered Dictionaries-Footnote-21082354 Node: PEP 378 Format Specifier for Thousands Separator1082403 Ref: whatsnew/3 1 pep-378-format-specifier-for-thousands-separator1082585 Ref: c161082585 Ref: PEP 378 Format Specifier for Thousands Separator-Footnote-11083824 Node: Other Language Changes<8>1083873 Ref: whatsnew/3 1 other-language-changes1084065 Ref: c171084065 Ref: Other Language Changes<8>-Footnote-11088862 Ref: Other Language Changes<8>-Footnote-21088907 Ref: Other Language Changes<8>-Footnote-31088949 Ref: Other Language Changes<8>-Footnote-41088991 Ref: Other Language Changes<8>-Footnote-51089033 Ref: Other Language Changes<8>-Footnote-61089078 Ref: Other Language Changes<8>-Footnote-71089120 Node: New Improved and Deprecated Modules<2>1089162 Ref: whatsnew/3 1 new-improved-and-deprecated-modules1089322 Ref: c181089322 Ref: New Improved and Deprecated Modules<2>-Footnote-11097850 Ref: New Improved and Deprecated Modules<2>-Footnote-21097895 Ref: New Improved and Deprecated Modules<2>-Footnote-31097937 Ref: New Improved and Deprecated Modules<2>-Footnote-41097979 Ref: New Improved and Deprecated Modules<2>-Footnote-51098021 Ref: New Improved and Deprecated Modules<2>-Footnote-61098063 Ref: New Improved and Deprecated Modules<2>-Footnote-71098112 Ref: New Improved and Deprecated Modules<2>-Footnote-81098154 Ref: New Improved and Deprecated Modules<2>-Footnote-91098196 Ref: New Improved and Deprecated Modules<2>-Footnote-101098238 Ref: New Improved and Deprecated Modules<2>-Footnote-111098281 Ref: New Improved and Deprecated Modules<2>-Footnote-121098324 Ref: New Improved and Deprecated Modules<2>-Footnote-131098367 Node: Optimizations<7>1098410 Ref: whatsnew/3 1 optimizations1098552 Ref: c1e1098552 Ref: Optimizations<7>-Footnote-11100729 Ref: Optimizations<7>-Footnote-21100778 Ref: Optimizations<7>-Footnote-31100820 Ref: Optimizations<7>-Footnote-41100862 Ref: Optimizations<7>-Footnote-51100904 Ref: Optimizations<7>-Footnote-61100929 Ref: Optimizations<7>-Footnote-71100971 Node: IDLE<2>1101013 Ref: whatsnew/3 1 idle1101143 Ref: c1f1101143 Ref: IDLE<2>-Footnote-11101358 Node: Build and C API Changes<6>1101400 Ref: whatsnew/3 1 build-and-c-api-changes1101535 Ref: c201101535 Ref: Build and C API Changes<6>-Footnote-11103760 Ref: Build and C API Changes<6>-Footnote-21103802 Ref: Build and C API Changes<6>-Footnote-31103844 Ref: Build and C API Changes<6>-Footnote-41103886 Ref: Build and C API Changes<6>-Footnote-51103928 Node: Porting to Python 3 11103970 Ref: whatsnew/3 1 porting-to-python-3-11104089 Ref: c241104089 Node: What’s New In Python 3 01105219 Ref: whatsnew/3 0 doc1105374 Ref: c251105374 Ref: whatsnew/3 0 what-s-new-in-python-3-01105374 Ref: c261105374 Node: Common Stumbling Blocks1107185 Ref: whatsnew/3 0 common-stumbling-blocks1107306 Ref: c271107306 Node: Print Is A Function1107674 Ref: whatsnew/3 0 print-is-a-function1107798 Ref: c281107798 Ref: Print Is A Function-Footnote-11109482 Node: Views And Iterators Instead Of Lists1109531 Ref: whatsnew/3 0 views-and-iterators-instead-of-lists1109684 Ref: c291109684 Node: Ordering Comparisons1111524 Ref: whatsnew/3 0 ordering-comparisons1111666 Ref: c331111666 Node: Integers1113117 Ref: whatsnew/3 0 integers1113263 Ref: c351113263 Ref: Integers-Footnote-11114485 Ref: Integers-Footnote-21114534 Node: Text Vs Data Instead Of Unicode Vs 8-bit1114583 Ref: whatsnew/3 0 text-vs-data-instead-of-unicode-vs-8-bit1114700 Ref: c361114700 Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-11121284 Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-21121333 Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-31121382 Node: Overview Of Syntax Changes1121431 Ref: whatsnew/3 0 overview-of-syntax-changes1121598 Ref: c3d1121598 Node: New Syntax1121808 Ref: whatsnew/3 0 new-syntax1121904 Ref: c3e1121904 Ref: New Syntax-Footnote-11124450 Ref: New Syntax-Footnote-21124499 Ref: New Syntax-Footnote-31124548 Ref: New Syntax-Footnote-41124597 Ref: New Syntax-Footnote-51124646 Node: Changed Syntax1124695 Ref: whatsnew/3 0 changed-syntax1124814 Ref: c411124814 Ref: Changed Syntax-Footnote-11126507 Ref: Changed Syntax-Footnote-21126556 Ref: Changed Syntax-Footnote-31126605 Ref: Changed Syntax-Footnote-41126654 Node: Removed Syntax1126703 Ref: whatsnew/3 0 removed-syntax1126803 Ref: c431126803 Ref: Removed Syntax-Footnote-11127993 Ref: Removed Syntax-Footnote-21128042 Node: Changes Already Present In Python 2 61128091 Ref: whatsnew/3 0 changes-already-present-in-python-2-61128250 Ref: c461128250 Node: Library Changes1132087 Ref: whatsnew/3 0 library-changes1132264 Ref: c591132264 Ref: Library Changes-Footnote-11138492 Ref: Library Changes-Footnote-21138541 Ref: Library Changes-Footnote-31138590 Ref: Library Changes-Footnote-41138639 Ref: Library Changes-Footnote-51138688 Ref: Library Changes-Footnote-61138737 Node: PEP 3101 A New Approach To String Formatting1138786 Ref: whatsnew/3 0 pep-3101-a-new-approach-to-string-formatting1138947 Ref: c5d1138947 Ref: PEP 3101 A New Approach To String Formatting-Footnote-11139399 Node: Changes To Exceptions1139448 Ref: whatsnew/3 0 changes-to-exceptions1139621 Ref: c5e1139621 Ref: Changes To Exceptions-Footnote-11143125 Ref: Changes To Exceptions-Footnote-21143174 Ref: Changes To Exceptions-Footnote-31143223 Ref: Changes To Exceptions-Footnote-41143272 Ref: Changes To Exceptions-Footnote-51143321 Node: Miscellaneous Other Changes1143370 Ref: whatsnew/3 0 miscellaneous-other-changes1143525 Ref: c601143525 Node: Operators And Special Methods1143651 Ref: whatsnew/3 0 operators-and-special-methods1143761 Ref: c611143761 Ref: Operators And Special Methods-Footnote-11145401 Node: Builtins1145450 Ref: whatsnew/3 0 builtins1145560 Ref: c691145560 Ref: Builtins-Footnote-11148031 Ref: Builtins-Footnote-21148080 Node: Build and C API Changes<7>1148129 Ref: whatsnew/3 0 build-and-c-api-changes1148274 Ref: c711148274 Ref: Build and C API Changes<7>-Footnote-11149307 Ref: Build and C API Changes<7>-Footnote-21149356 Ref: Build and C API Changes<7>-Footnote-31149405 Node: Performance1149454 Ref: whatsnew/3 0 performance1149593 Ref: c741149593 Node: Porting To Python 3 01149912 Ref: whatsnew/3 0 porting-to-python-3-01150016 Ref: c751150016 Node: What’s New in Python 2 71151617 Ref: whatsnew/2 7 doc1151772 Ref: c781151772 Ref: whatsnew/2 7 what-s-new-in-python-2-71151772 Ref: c791151772 Node: The Future for Python 2 x1154235 Ref: whatsnew/2 7 the-future-for-python-2-x1154379 Ref: c7a1154379 Ref: whatsnew/2 7 whatsnew27-python311154379 Ref: c7b1154379 Ref: The Future for Python 2 x-Footnote-11157726 Ref: The Future for Python 2 x-Footnote-21157775 Node: Changes to the Handling of Deprecation Warnings1157812 Ref: whatsnew/2 7 changes-to-the-handling-of-deprecation-warnings1157984 Ref: c7e1157984 Ref: Changes to the Handling of Deprecation Warnings-Footnote-11159559 Node: Python 3 1 Features1159601 Ref: whatsnew/2 7 python-3-1-features1159799 Ref: c7f1159799 Node: PEP 372 Adding an Ordered Dictionary to collections1161718 Ref: whatsnew/2 7 pep-03721161920 Ref: c801161920 Ref: whatsnew/2 7 pep-372-adding-an-ordered-dictionary-to-collections1161920 Ref: c831161920 Ref: PEP 372 Adding an Ordered Dictionary to collections-Footnote-11165524 Ref: PEP 372 Adding an Ordered Dictionary to collections-Footnote-21165551 Node: PEP 378 Format Specifier for Thousands Separator<2>1165600 Ref: whatsnew/2 7 pep-03781165836 Ref: c811165836 Ref: whatsnew/2 7 pep-378-format-specifier-for-thousands-separator1165836 Ref: c851165836 Ref: PEP 378 Format Specifier for Thousands Separator<2>-Footnote-11167353 Node: PEP 389 The argparse Module for Parsing Command Lines1167402 Ref: whatsnew/2 7 pep-389-the-argparse-module-for-parsing-command-lines1167637 Ref: c861167637 Ref: PEP 389 The argparse Module for Parsing Command Lines-Footnote-11171661 Node: PEP 391 Dictionary-Based Configuration For Logging1171710 Ref: whatsnew/2 7 pep-391-dictionary-based-configuration-for-logging1171919 Ref: c871171919 Ref: PEP 391 Dictionary-Based Configuration For Logging-Footnote-11175787 Node: PEP 3106 Dictionary Views1175836 Ref: whatsnew/2 7 pep-3106-dictionary-views1176022 Ref: c8d1176022 Ref: PEP 3106 Dictionary Views-Footnote-11178139 Ref: PEP 3106 Dictionary Views-Footnote-21178188 Node: PEP 3137 The memoryview Object1178230 Ref: whatsnew/2 7 pep-3137-the-memoryview-object1178391 Ref: c8e1178391 Ref: PEP 3137 The memoryview Object-Footnote-11180056 Ref: PEP 3137 The memoryview Object-Footnote-21180105 Node: Other Language Changes<9>1180147 Ref: whatsnew/2 7 other-language-changes1180307 Ref: c8f1180307 Ref: Other Language Changes<9>-Footnote-11190263 Ref: Other Language Changes<9>-Footnote-21190305 Ref: Other Language Changes<9>-Footnote-31190347 Ref: Other Language Changes<9>-Footnote-41190389 Ref: Other Language Changes<9>-Footnote-51190431 Ref: Other Language Changes<9>-Footnote-61190473 Ref: Other Language Changes<9>-Footnote-71190515 Ref: Other Language Changes<9>-Footnote-81190557 Ref: Other Language Changes<9>-Footnote-91190599 Ref: Other Language Changes<9>-Footnote-101190641 Ref: Other Language Changes<9>-Footnote-111190684 Ref: Other Language Changes<9>-Footnote-121190727 Ref: Other Language Changes<9>-Footnote-131190770 Ref: Other Language Changes<9>-Footnote-141190813 Ref: Other Language Changes<9>-Footnote-151190859 Ref: Other Language Changes<9>-Footnote-161190902 Ref: Other Language Changes<9>-Footnote-171190945 Ref: Other Language Changes<9>-Footnote-181190988 Ref: Other Language Changes<9>-Footnote-191191034 Ref: Other Language Changes<9>-Footnote-201191077 Ref: Other Language Changes<9>-Footnote-211191120 Ref: Other Language Changes<9>-Footnote-221191163 Ref: Other Language Changes<9>-Footnote-231191206 Ref: Other Language Changes<9>-Footnote-241191249 Node: Interpreter Changes1191292 Ref: whatsnew/2 7 interpreter-changes1191398 Ref: c921191398 Ref: whatsnew/2 7 new-27-interpreter1191398 Ref: c931191398 Ref: Interpreter Changes-Footnote-11192052 Node: Optimizations<8>1192094 Ref: whatsnew/2 7 optimizations1192200 Ref: c941192200 Ref: Optimizations<8>-Footnote-11197047 Ref: Optimizations<8>-Footnote-21197089 Ref: Optimizations<8>-Footnote-31197131 Ref: Optimizations<8>-Footnote-41197173 Ref: Optimizations<8>-Footnote-51197215 Ref: Optimizations<8>-Footnote-61197257 Ref: Optimizations<8>-Footnote-71197302 Ref: Optimizations<8>-Footnote-81197344 Ref: Optimizations<8>-Footnote-91197386 Ref: Optimizations<8>-Footnote-101197428 Ref: Optimizations<8>-Footnote-111197471 Ref: Optimizations<8>-Footnote-121197514 Ref: Optimizations<8>-Footnote-131197557 Node: New and Improved Modules1197600 Ref: whatsnew/2 7 new-and-improved-modules1197756 Ref: c971197756 Ref: New and Improved Modules-Footnote-11232932 Ref: New and Improved Modules-Footnote-21232974 Ref: New and Improved Modules-Footnote-31233016 Ref: New and Improved Modules-Footnote-41233069 Ref: New and Improved Modules-Footnote-51233111 Ref: New and Improved Modules-Footnote-61233153 Ref: New and Improved Modules-Footnote-71233198 Ref: New and Improved Modules-Footnote-81233240 Ref: New and Improved Modules-Footnote-91233282 Ref: New and Improved Modules-Footnote-101233324 Ref: New and Improved Modules-Footnote-111233367 Ref: New and Improved Modules-Footnote-121233410 Ref: New and Improved Modules-Footnote-131233453 Ref: New and Improved Modules-Footnote-141233493 Ref: New and Improved Modules-Footnote-151233536 Ref: New and Improved Modules-Footnote-161233579 Ref: New and Improved Modules-Footnote-171233622 Ref: New and Improved Modules-Footnote-181233665 Ref: New and Improved Modules-Footnote-191233708 Ref: New and Improved Modules-Footnote-201233751 Ref: New and Improved Modules-Footnote-211233794 Ref: New and Improved Modules-Footnote-221233837 Ref: New and Improved Modules-Footnote-231233880 Ref: New and Improved Modules-Footnote-241233923 Ref: New and Improved Modules-Footnote-251233966 Ref: New and Improved Modules-Footnote-261234009 Ref: New and Improved Modules-Footnote-271234055 Ref: New and Improved Modules-Footnote-281234098 Ref: New and Improved Modules-Footnote-291234141 Ref: New and Improved Modules-Footnote-301234184 Ref: New and Improved Modules-Footnote-311234227 Ref: New and Improved Modules-Footnote-321234270 Ref: New and Improved Modules-Footnote-331234313 Ref: New and Improved Modules-Footnote-341234356 Ref: New and Improved Modules-Footnote-351234399 Ref: New and Improved Modules-Footnote-361234442 Ref: New and Improved Modules-Footnote-371234485 Ref: New and Improved Modules-Footnote-381234528 Ref: New and Improved Modules-Footnote-391234571 Ref: New and Improved Modules-Footnote-401234614 Ref: New and Improved Modules-Footnote-411234657 Ref: New and Improved Modules-Footnote-421234700 Ref: New and Improved Modules-Footnote-431234743 Ref: New and Improved Modules-Footnote-441234786 Ref: New and Improved Modules-Footnote-451234829 Ref: New and Improved Modules-Footnote-461234872 Ref: New and Improved Modules-Footnote-471234915 Ref: New and Improved Modules-Footnote-481234958 Ref: New and Improved Modules-Footnote-491235004 Ref: New and Improved Modules-Footnote-501235047 Ref: New and Improved Modules-Footnote-511235090 Ref: New and Improved Modules-Footnote-521235133 Ref: New and Improved Modules-Footnote-531235176 Ref: New and Improved Modules-Footnote-541235219 Ref: New and Improved Modules-Footnote-551235262 Ref: New and Improved Modules-Footnote-561235305 Ref: New and Improved Modules-Footnote-571235348 Ref: New and Improved Modules-Footnote-581235391 Ref: New and Improved Modules-Footnote-591235434 Ref: New and Improved Modules-Footnote-601235477 Ref: New and Improved Modules-Footnote-611235520 Ref: New and Improved Modules-Footnote-621235563 Ref: New and Improved Modules-Footnote-631235606 Ref: New and Improved Modules-Footnote-641235649 Ref: New and Improved Modules-Footnote-651235692 Ref: New and Improved Modules-Footnote-661235735 Ref: New and Improved Modules-Footnote-671235778 Ref: New and Improved Modules-Footnote-681235821 Ref: New and Improved Modules-Footnote-691235864 Ref: New and Improved Modules-Footnote-701235910 Ref: New and Improved Modules-Footnote-711235953 Ref: New and Improved Modules-Footnote-721235996 Ref: New and Improved Modules-Footnote-731236082 Ref: New and Improved Modules-Footnote-741236125 Ref: New and Improved Modules-Footnote-751236168 Ref: New and Improved Modules-Footnote-761236211 Ref: New and Improved Modules-Footnote-771236254 Ref: New and Improved Modules-Footnote-781236297 Ref: New and Improved Modules-Footnote-791236343 Ref: New and Improved Modules-Footnote-801236386 Ref: New and Improved Modules-Footnote-811236429 Ref: New and Improved Modules-Footnote-821236472 Ref: New and Improved Modules-Footnote-831236515 Ref: New and Improved Modules-Footnote-841236558 Ref: New and Improved Modules-Footnote-851236601 Ref: New and Improved Modules-Footnote-861236647 Ref: New and Improved Modules-Footnote-871236693 Ref: New and Improved Modules-Footnote-881236736 Ref: New and Improved Modules-Footnote-891236786 Ref: New and Improved Modules-Footnote-901236836 Ref: New and Improved Modules-Footnote-911236879 Ref: New and Improved Modules-Footnote-921236922 Ref: New and Improved Modules-Footnote-931236965 Ref: New and Improved Modules-Footnote-941237008 Ref: New and Improved Modules-Footnote-951237051 Ref: New and Improved Modules-Footnote-961237094 Ref: New and Improved Modules-Footnote-971237137 Node: New module importlib1237180 Ref: whatsnew/2 7 importlib-section1237290 Ref: c821237290 Ref: whatsnew/2 7 new-module-importlib1237290 Ref: cbc1237290 Node: New module sysconfig1238830 Ref: whatsnew/2 7 new-module-sysconfig1238974 Ref: cbd1238974 Node: ttk Themed Widgets for Tk1240300 Ref: whatsnew/2 7 ttk-themed-widgets-for-tk1240447 Ref: cc01240447 Ref: ttk Themed Widgets for Tk-Footnote-11241519 Ref: ttk Themed Widgets for Tk-Footnote-21241561 Node: Updated module unittest1241603 Ref: whatsnew/2 7 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Node: Build and C API Changes<8>1255310 Ref: whatsnew/2 7 build-and-c-api-changes1255464 Ref: ce81255464 Ref: Build and C API Changes<8>-Footnote-11264135 Ref: Build and C API Changes<8>-Footnote-21264205 Ref: Build and C API Changes<8>-Footnote-31264247 Ref: Build and C API Changes<8>-Footnote-41264289 Ref: Build and C API Changes<8>-Footnote-51264331 Ref: Build and C API Changes<8>-Footnote-61264373 Ref: Build and C API Changes<8>-Footnote-71264415 Ref: Build and C API Changes<8>-Footnote-81264457 Ref: Build and C API Changes<8>-Footnote-91264526 Ref: Build and C API Changes<8>-Footnote-101264568 Ref: Build and C API Changes<8>-Footnote-111264611 Ref: Build and C API Changes<8>-Footnote-121264654 Ref: Build and C API Changes<8>-Footnote-131264697 Ref: Build and C API Changes<8>-Footnote-141264743 Ref: Build and C API Changes<8>-Footnote-151264789 Ref: Build and C API Changes<8>-Footnote-161264832 Ref: Build and C API Changes<8>-Footnote-171264875 Ref: Build and C API Changes<8>-Footnote-181264918 Ref: Build and C API Changes<8>-Footnote-191264961 Ref: Build and C API Changes<8>-Footnote-201265004 Ref: Build and C API Changes<8>-Footnote-211265050 Ref: Build and C API Changes<8>-Footnote-221265093 Node: Capsules1265136 Ref: whatsnew/2 7 capsules1265245 Ref: cee1265245 Ref: whatsnew/2 7 whatsnew27-capsules1265245 Ref: cef1265245 Ref: Capsules-Footnote-11267244 Node: Port-Specific Changes Windows1267286 Ref: whatsnew/2 7 port-specific-changes-windows1267434 Ref: cf21267434 Ref: Port-Specific Changes Windows-Footnote-11269126 Ref: Port-Specific Changes Windows-Footnote-21269168 Ref: Port-Specific Changes Windows-Footnote-31269210 Ref: Port-Specific Changes Windows-Footnote-41269252 Ref: Port-Specific Changes Windows-Footnote-51269297 Ref: Port-Specific Changes Windows-Footnote-61269339 Node: Port-Specific Changes Mac OS X1269381 Ref: whatsnew/2 7 port-specific-changes-mac-os-x1269550 Ref: cf41269550 Ref: Port-Specific Changes Mac OS X-Footnote-11270595 Ref: Port-Specific Changes Mac OS X-Footnote-21270637 Node: Port-Specific Changes FreeBSD1270680 Ref: whatsnew/2 7 port-specific-changes-freebsd1270811 Ref: cf51270811 Ref: Port-Specific Changes FreeBSD-Footnote-11271171 Node: Other Changes and Fixes1271213 Ref: whatsnew/2 7 other-changes-and-fixes1271364 Ref: cf61271364 Ref: Other Changes and Fixes-Footnote-11273552 Ref: Other Changes and Fixes-Footnote-21273594 Ref: Other Changes and Fixes-Footnote-31273639 Ref: Other Changes and Fixes-Footnote-41273681 Ref: Other Changes and Fixes-Footnote-51273723 Node: Porting to Python 2 71273765 Ref: whatsnew/2 7 porting-to-python-2-71273943 Ref: cf71273943 Ref: Porting to Python 2 7-Footnote-11279510 Ref: Porting to Python 2 7-Footnote-21279552 Ref: Porting to Python 2 7-Footnote-31279594 Ref: Porting to Python 2 7-Footnote-41279636 Ref: Porting to Python 2 7-Footnote-51279678 Ref: Porting to Python 2 7-Footnote-61279720 Ref: Porting to Python 2 7-Footnote-71279762 Ref: Porting to Python 2 7-Footnote-81279804 Ref: Porting to Python 2 7-Footnote-91279846 Ref: Porting to Python 2 7-Footnote-101279888 Ref: Porting to Python 2 7-Footnote-111279931 Ref: Porting to Python 2 7-Footnote-121279974 Ref: Porting to Python 2 7-Footnote-131280017 Ref: Porting to Python 2 7-Footnote-141280067 Node: New Features Added to Python 2 7 Maintenance Releases1280110 Ref: whatsnew/2 7 new-features-added-to-python-2-7-maintenance-releases1280281 Ref: cf81280281 Ref: whatsnew/2 7 py27-maintenance-enhancements1280281 Ref: c7c1280281 Node: Two new environment variables for debug mode1281746 Ref: whatsnew/2 7 two-new-environment-variables-for-debug-mode1281940 Ref: cf91281940 Ref: Two new environment variables for debug mode-Footnote-11282619 Ref: Two new environment variables for debug mode-Footnote-21282662 Node: PEP 434 IDLE Enhancement Exception for All Branches1282705 Ref: whatsnew/2 7 pep-434-idle-enhancement-exception-for-all-branches1282960 Ref: cfa1282960 Ref: PEP 434 IDLE Enhancement Exception for All Branches-Footnote-11283480 Node: PEP 466 Network Security Enhancements for Python 2 71283529 Ref: whatsnew/2 7 pep-466-network-security-enhancements-for-python-2-71283788 Ref: cfb1283788 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-11286017 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-21286066 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-31286115 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-41286158 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-51286201 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-61286250 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-71286293 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-81286336 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-91286385 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-101286428 Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-111286472 Node: PEP 477 Backport ensurepip PEP 453 to Python 2 71286516 Ref: whatsnew/2 7 pep-477-backport-ensurepip-pep-453-to-python-2-71286803 Ref: cfe1286803 Ref: PEP 477 Backport ensurepip PEP 453 to Python 2 7-Footnote-11287299 Ref: PEP 477 Backport ensurepip PEP 453 to Python 2 7-Footnote-21287348 Node: Bootstrapping pip By Default<2>1287397 Ref: whatsnew/2 7 bootstrapping-pip-by-default1287546 Ref: cff1287546 Ref: Bootstrapping pip By Default<2>-Footnote-11289214 Ref: Bootstrapping pip By Default<2>-Footnote-21289263 Node: Documentation Changes<2>1289361 Ref: whatsnew/2 7 documentation-changes1289510 Ref: d001289510 Ref: whatsnew/2 7 id11289510 Ref: d011289510 Ref: Documentation Changes<2>-Footnote-11290465 Ref: Documentation Changes<2>-Footnote-21290501 Node: PEP 476 Enabling certificate verification by default for stdlib http clients<2>1290550 Ref: whatsnew/2 7 pep-476-enabling-certificate-verification-by-default-for-stdlib-http-clients1290842 Ref: d021290842 Ref: PEP 476 Enabling certificate verification by default for stdlib http clients<2>-Footnote-11291923 Node: PEP 493 HTTPS verification migration tools for Python 2 71291972 Ref: whatsnew/2 7 pep-493-https-verification-migration-tools-for-python-2-71292250 Ref: d031292250 Ref: PEP 493 HTTPS verification migration tools for Python 2 7-Footnote-11293414 Node: New make regen-all build target<3>1293463 Ref: whatsnew/2 7 new-make-regen-all-build-target1293699 Ref: d041293699 Ref: New make regen-all build target<3>-Footnote-11294489 Ref: New make regen-all build target<3>-Footnote-21294556 Node: Removal of make touch build target<3>1294599 Ref: whatsnew/2 7 removal-of-make-touch-build-target1294769 Ref: d051294769 Ref: Removal of make touch build target<3>-Footnote-11295204 Node: Acknowledgements1295247 Ref: whatsnew/2 7 acknowledgements1295388 Ref: d061295388 Ref: whatsnew/2 7 acks271295388 Ref: d071295388 Node: What’s New in Python 2 61295661 Ref: whatsnew/2 6 doc1295816 Ref: d081295816 Ref: whatsnew/2 6 what-s-new-in-python-2-61295816 Ref: d091295816 Ref: whatsnew/2 6 whats-new-in-2-61295816 Ref: c471295816 Ref: What’s New in Python 2 6-Footnote-11298879 Node: Python 3 01298928 Ref: whatsnew/2 6 python-3-01299044 Ref: d0a1299044 Ref: Python 3 0-Footnote-11301158 Ref: Python 3 0-Footnote-21301207 Node: Changes to the Development Process1301256 Ref: whatsnew/2 6 changes-to-the-development-process1301413 Ref: d0b1301413 Node: New Issue Tracker Roundup1301931 Ref: whatsnew/2 6 new-issue-tracker-roundup1302090 Ref: d0c1302090 Ref: New Issue Tracker Roundup-Footnote-11304137 Ref: New Issue Tracker Roundup-Footnote-21304186 Ref: New Issue Tracker Roundup-Footnote-31304217 Ref: New Issue Tracker Roundup-Footnote-41304257 Ref: New Issue Tracker Roundup-Footnote-51304292 Node: New Documentation Format reStructuredText Using Sphinx1304333 Ref: whatsnew/2 6 new-documentation-format-restructuredtext-using-sphinx1304492 Ref: d0d1304492 Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-11306602 Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-21306661 Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-31306710 Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-41306741 Node: PEP 343 The ‘with’ statement1306781 Ref: whatsnew/2 6 pep-03431306980 Ref: c481306980 Ref: whatsnew/2 6 pep-343-the-with-statement1306980 Ref: d0e1306980 Node: Writing Context Managers1310256 Ref: whatsnew/2 6 new-26-context-managers1310379 Ref: c491310379 Ref: whatsnew/2 6 writing-context-managers1310379 Ref: d0f1310379 Node: The contextlib module1314892 Ref: whatsnew/2 6 new-module-contextlib1315015 Ref: c4a1315015 Ref: whatsnew/2 6 the-contextlib-module1315015 Ref: d101315015 Ref: The contextlib module-Footnote-11317517 Node: PEP 366 Explicit Relative Imports From a Main Module1317566 Ref: whatsnew/2 6 pep-03661317771 Ref: c4b1317771 Ref: whatsnew/2 6 pep-366-explicit-relative-imports-from-a-main-module1317771 Ref: d111317771 Node: PEP 370 Per-user site-packages Directory1318534 Ref: whatsnew/2 6 pep-03701318742 Ref: c4c1318742 Ref: whatsnew/2 6 pep-370-per-user-site-packages-directory1318742 Ref: d131318742 Ref: PEP 370 Per-user site-packages Directory-Footnote-11320201 Node: PEP 371 The multiprocessing Package1320250 Ref: whatsnew/2 6 pep-03711320441 Ref: c4d1320441 Ref: whatsnew/2 6 pep-371-the-multiprocessing-package1320441 Ref: d171320441 Ref: PEP 371 The multiprocessing Package-Footnote-11325580 Node: PEP 3101 Advanced String Formatting1325629 Ref: whatsnew/2 6 pep-31011325808 Ref: c4e1325808 Ref: whatsnew/2 6 pep-3101-advanced-string-formatting1325808 Ref: d191325808 Ref: PEP 3101 Advanced String Formatting-Footnote-11331521 Node: PEP 3105 print As a Function1331570 Ref: whatsnew/2 6 pep-31051331749 Ref: c4f1331749 Ref: whatsnew/2 6 pep-3105-print-as-a-function1331749 Ref: d1b1331749 Ref: PEP 3105 print As a Function-Footnote-11332903 Node: PEP 3110 Exception-Handling Changes1332952 Ref: whatsnew/2 6 pep-31101333118 Ref: c501333118 Ref: whatsnew/2 6 pep-3110-exception-handling-changes1333118 Ref: d1c1333118 Ref: PEP 3110 Exception-Handling Changes-Footnote-11334719 Node: PEP 3112 Byte Literals1334768 Ref: whatsnew/2 6 pep-31121334930 Ref: c511334930 Ref: whatsnew/2 6 pep-3112-byte-literals1334930 Ref: d1d1334930 Ref: PEP 3112 Byte Literals-Footnote-11337944 Node: PEP 3116 New I/O Library1337993 Ref: whatsnew/2 6 pep-31161338152 Ref: c521338152 Ref: whatsnew/2 6 pep-3116-new-i-o-library1338152 Ref: d231338152 Ref: PEP 3116 New I/O Library-Footnote-11341778 Node: PEP 3118 Revised Buffer Protocol1341827 Ref: whatsnew/2 6 pep-31181341994 Ref: c531341994 Ref: whatsnew/2 6 pep-3118-revised-buffer-protocol1341994 Ref: d241341994 Ref: PEP 3118 Revised Buffer Protocol-Footnote-11344133 Node: PEP 3119 Abstract Base Classes1344182 Ref: whatsnew/2 6 pep-31191344368 Ref: c541344368 Ref: whatsnew/2 6 pep-3119-abstract-base-classes1344368 Ref: d261344368 Ref: PEP 3119 Abstract Base Classes-Footnote-11349737 Node: PEP 3127 Integer Literal Support and Syntax1349786 Ref: whatsnew/2 6 pep-31271349965 Ref: c551349965 Ref: whatsnew/2 6 pep-3127-integer-literal-support-and-syntax1349965 Ref: d291349965 Ref: PEP 3127 Integer Literal Support and Syntax-Footnote-11351330 Node: PEP 3129 Class Decorators1351379 Ref: whatsnew/2 6 pep-31291351565 Ref: c561351565 Ref: whatsnew/2 6 pep-3129-class-decorators1351565 Ref: d2a1351565 Ref: PEP 3129 Class Decorators-Footnote-11351965 Node: PEP 3141 A Type Hierarchy for Numbers1352014 Ref: whatsnew/2 6 pep-31411352183 Ref: c571352183 Ref: whatsnew/2 6 pep-3141-a-type-hierarchy-for-numbers1352183 Ref: d2b1352183 Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-11354384 Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-21354433 Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-31354531 Node: The fractions Module1354616 Ref: whatsnew/2 6 the-fractions-module1354710 Ref: d2f1354710 Node: Other Language Changes<10>1356317 Ref: whatsnew/2 6 other-language-changes1356488 Ref: d301356488 Ref: Other Language Changes<10>-Footnote-11365337 Ref: Other Language Changes<10>-Footnote-21365382 Ref: Other Language Changes<10>-Footnote-31365424 Ref: Other Language Changes<10>-Footnote-41365469 Ref: Other Language Changes<10>-Footnote-51365511 Ref: Other Language Changes<10>-Footnote-61365553 Ref: Other Language Changes<10>-Footnote-71365595 Ref: Other Language Changes<10>-Footnote-81365637 Ref: Other Language Changes<10>-Footnote-91365679 Ref: Other Language Changes<10>-Footnote-101365721 Ref: Other Language Changes<10>-Footnote-111365764 Ref: Other Language Changes<10>-Footnote-121365807 Ref: Other Language Changes<10>-Footnote-131365853 Ref: Other Language Changes<10>-Footnote-141365899 Ref: Other Language Changes<10>-Footnote-151365945 Ref: Other Language Changes<10>-Footnote-161365991 Node: Optimizations<9>1366037 Ref: whatsnew/2 6 optimizations1366147 Ref: d341366147 Ref: Optimizations<9>-Footnote-11369003 Ref: Optimizations<9>-Footnote-21369048 Ref: Optimizations<9>-Footnote-31369093 Ref: Optimizations<9>-Footnote-41369135 Node: Interpreter Changes<2>1369177 Ref: whatsnew/2 6 interpreter-changes1369287 Ref: d351369287 Ref: whatsnew/2 6 new-26-interpreter1369287 Ref: d361369287 Node: New and Improved Modules<2>1370873 Ref: whatsnew/2 6 new-and-improved-modules1371032 Ref: d3a1371032 Ref: New and Improved Modules<2>-Footnote-11413464 Ref: New and Improved Modules<2>-Footnote-21413509 Ref: New and Improved Modules<2>-Footnote-31413562 Ref: New and Improved Modules<2>-Footnote-41413604 Ref: New and Improved Modules<2>-Footnote-51413648 Ref: New and Improved Modules<2>-Footnote-61413690 Ref: New and Improved Modules<2>-Footnote-71413735 Ref: New and Improved Modules<2>-Footnote-81413777 Ref: New and Improved Modules<2>-Footnote-91413830 Ref: New and Improved Modules<2>-Footnote-101413875 Ref: New and Improved Modules<2>-Footnote-111413921 Ref: New and Improved Modules<2>-Footnote-121413967 Ref: New and Improved Modules<2>-Footnote-131414010 Ref: New and Improved Modules<2>-Footnote-141414053 Ref: New and Improved Modules<2>-Footnote-151414098 Ref: New and Improved Modules<2>-Footnote-161414141 Ref: New and Improved Modules<2>-Footnote-171414187 Ref: New and Improved Modules<2>-Footnote-181414230 Ref: New and Improved Modules<2>-Footnote-191414276 Ref: New and Improved Modules<2>-Footnote-201414322 Ref: New and Improved Modules<2>-Footnote-211414368 Ref: New and Improved Modules<2>-Footnote-221414413 Ref: New and Improved Modules<2>-Footnote-231414459 Ref: New and Improved Modules<2>-Footnote-241414505 Ref: New and Improved Modules<2>-Footnote-251414548 Ref: New and Improved Modules<2>-Footnote-261414591 Ref: New and Improved Modules<2>-Footnote-271414637 Ref: New and Improved Modules<2>-Footnote-281414683 Ref: New and Improved Modules<2>-Footnote-291414728 Ref: New and Improved Modules<2>-Footnote-301414771 Ref: New and Improved Modules<2>-Footnote-311414814 Ref: New and Improved Modules<2>-Footnote-321414857 Ref: New and Improved Modules<2>-Footnote-331414900 Ref: New and Improved Modules<2>-Footnote-341414943 Ref: New and Improved Modules<2>-Footnote-351414986 Ref: New and Improved Modules<2>-Footnote-361415029 Ref: New and Improved Modules<2>-Footnote-371415079 Ref: New and Improved Modules<2>-Footnote-381415124 Ref: New and Improved Modules<2>-Footnote-391415174 Ref: New and Improved Modules<2>-Footnote-401415219 Ref: New and Improved Modules<2>-Footnote-411415262 Ref: New and Improved Modules<2>-Footnote-421415307 Ref: New and Improved Modules<2>-Footnote-431415353 Ref: New and Improved Modules<2>-Footnote-441415396 Ref: New and Improved Modules<2>-Footnote-451415439 Ref: New and Improved Modules<2>-Footnote-461415482 Ref: New and Improved Modules<2>-Footnote-471415528 Ref: New and Improved Modules<2>-Footnote-481415571 Ref: New and Improved Modules<2>-Footnote-491415614 Ref: New and Improved Modules<2>-Footnote-501415660 Ref: New and Improved Modules<2>-Footnote-511415703 Ref: New and Improved Modules<2>-Footnote-521415749 Ref: New and Improved Modules<2>-Footnote-531415792 Ref: New and Improved Modules<2>-Footnote-541415838 Ref: New and Improved Modules<2>-Footnote-551415881 Ref: New and Improved Modules<2>-Footnote-561415927 Ref: New and Improved Modules<2>-Footnote-571415970 Ref: New and Improved Modules<2>-Footnote-581416016 Ref: New and Improved Modules<2>-Footnote-591416062 Ref: New and Improved Modules<2>-Footnote-601416105 Ref: New and Improved Modules<2>-Footnote-611416148 Ref: New and Improved Modules<2>-Footnote-621416193 Ref: New and Improved Modules<2>-Footnote-631416239 Node: The ast module1416285 Ref: whatsnew/2 6 the-ast-module1416398 Ref: d4a1416398 Node: The future_builtins module1419059 Ref: whatsnew/2 6 the-future-builtins-module1419223 Ref: d4b1419223 Node: The json module JavaScript Object Notation1420338 Ref: whatsnew/2 6 the-json-module-javascript-object-notation1420530 Ref: d4d1420530 Node: The plistlib module A Property-List Parser1421542 Ref: whatsnew/2 6 the-plistlib-module-a-property-list-parser1421727 Ref: d4e1421727 Node: ctypes Enhancements1423098 Ref: whatsnew/2 6 ctypes-enhancements1423261 Ref: d4f1423261 Ref: ctypes Enhancements-Footnote-11425028 Ref: ctypes Enhancements-Footnote-21425073 Node: Improved SSL Support1425115 Ref: whatsnew/2 6 improved-ssl-support1425227 Ref: d501425227 Ref: Improved SSL Support-Footnote-11426180 Node: Deprecations and Removals1426213 Ref: whatsnew/2 6 deprecations-and-removals1426372 Ref: d511426372 Ref: Deprecations and Removals-Footnote-11428227 Node: Build and C API Changes<9>1428276 Ref: whatsnew/2 6 build-and-c-api-changes1428429 Ref: d531428429 Ref: Build and C API Changes<9>-Footnote-11434466 Ref: Build and C API Changes<9>-Footnote-21434508 Ref: Build and C API Changes<9>-Footnote-31434553 Ref: Build and C API Changes<9>-Footnote-41434595 Ref: Build and C API Changes<9>-Footnote-51434637 Node: Port-Specific Changes Windows<2>1434682 Ref: whatsnew/2 6 port-specific-changes-windows1434819 Ref: d5a1434819 Ref: Port-Specific Changes Windows<2>-Footnote-11437229 Ref: Port-Specific Changes Windows<2>-Footnote-21437273 Ref: Port-Specific Changes Windows<2>-Footnote-31437318 Node: Port-Specific Changes Mac OS X<2>1437360 Ref: whatsnew/2 6 port-specific-changes-mac-os-x1437532 Ref: d5b1437532 Ref: Port-Specific Changes Mac OS X<2>-Footnote-11438803 Node: Port-Specific Changes IRIX1438848 Ref: whatsnew/2 6 port-specific-changes-irix1438979 Ref: d5c1438979 Node: Porting to Python 2 61439498 Ref: whatsnew/2 6 porting-to-python-2-61439645 Ref: d5d1439645 Ref: Porting to Python 2 6-Footnote-11443070 Ref: Porting to Python 2 6-Footnote-21443115 Ref: Porting to Python 2 6-Footnote-31443160 Node: Acknowledgements<2>1443205 Ref: whatsnew/2 6 acknowledgements1443317 Ref: d601443317 Ref: whatsnew/2 6 acks1443317 Ref: d611443317 Node: What’s New in Python 2 51443659 Ref: whatsnew/2 5 doc1443814 Ref: d621443814 Ref: whatsnew/2 5 what-s-new-in-python-2-51443814 Ref: d631443814 Ref: What’s New in Python 2 5-Footnote-11447417 Node: PEP 308 Conditional Expressions1447466 Ref: whatsnew/2 5 pep-3081447605 Ref: d641447605 Ref: whatsnew/2 5 pep-308-conditional-expressions1447605 Ref: d691447605 Ref: PEP 308 Conditional Expressions-Footnote-11451089 Ref: PEP 308 Conditional Expressions-Footnote-21451138 Node: PEP 309 Partial Function Application1451187 Ref: whatsnew/2 5 pep-3091451385 Ref: d6a1451385 Ref: whatsnew/2 5 pep-309-partial-function-application1451385 Ref: d6b1451385 Ref: PEP 309 Partial Function Application-Footnote-11454232 Node: PEP 314 Metadata for Python Software Packages v1 11454281 Ref: whatsnew/2 5 pep-3141454485 Ref: d6c1454485 Ref: whatsnew/2 5 pep-314-metadata-for-python-software-packages-v1-11454485 Ref: d6d1454485 Ref: PEP 314 Metadata for Python Software Packages v1 1-Footnote-11456319 Node: PEP 328 Absolute and Relative Imports1456368 Ref: whatsnew/2 5 pep-3281456572 Ref: d671456572 Ref: whatsnew/2 5 pep-328-absolute-and-relative-imports1456572 Ref: d6e1456572 Ref: PEP 328 Absolute and Relative Imports-Footnote-11460384 Ref: PEP 328 Absolute and Relative Imports-Footnote-21460433 Node: PEP 338 Executing Modules as Scripts1460482 Ref: whatsnew/2 5 pep-3381460670 Ref: d6f1460670 Ref: whatsnew/2 5 pep-338-executing-modules-as-scripts1460670 Ref: d701460670 Ref: PEP 338 Executing Modules as Scripts-Footnote-11461565 Node: PEP 341 Unified try/except/finally1461614 Ref: whatsnew/2 5 pep-3411461795 Ref: d681461795 Ref: whatsnew/2 5 pep-341-unified-try-except-finally1461795 Ref: d711461795 Ref: PEP 341 Unified try/except/finally-Footnote-11463562 Node: PEP 342 New Generator Features1463611 Ref: whatsnew/2 5 pep-3421463791 Ref: d661463791 Ref: whatsnew/2 5 pep-342-new-generator-features1463791 Ref: d731463791 Ref: PEP 342 New Generator Features-Footnote-11470408 Ref: PEP 342 New Generator Features-Footnote-21470457 Ref: PEP 342 New Generator Features-Footnote-31470506 Ref: PEP 342 New Generator Features-Footnote-41470555 Ref: PEP 342 New Generator Features-Footnote-51470604 Node: PEP 343 The ‘with’ statement<2>1470653 Ref: whatsnew/2 5 pep-3431470838 Ref: d651470838 Ref: whatsnew/2 5 pep-343-the-with-statement1470838 Ref: d741470838 Node: Writing Context Managers<2>1473858 Ref: whatsnew/2 5 new-25-context-managers1473990 Ref: d751473990 Ref: whatsnew/2 5 writing-context-managers1473990 Ref: d761473990 Node: The contextlib module<2>1478386 Ref: whatsnew/2 5 contextlibmod1478518 Ref: d771478518 Ref: whatsnew/2 5 the-contextlib-module1478518 Ref: d781478518 Ref: The contextlib module<2>-Footnote-11481011 Node: PEP 352 Exceptions as New-Style Classes1481060 Ref: whatsnew/2 5 pep-3521481254 Ref: d791481254 Ref: whatsnew/2 5 pep-352-exceptions-as-new-style-classes1481254 Ref: d7a1481254 Ref: PEP 352 Exceptions as New-Style Classes-Footnote-11483736 Node: PEP 353 Using ssize_t as the index type1483785 Ref: whatsnew/2 5 pep-3531483978 Ref: d7c1483978 Ref: whatsnew/2 5 pep-353-using-ssize-t-as-the-index-type1483978 Ref: d7d1483978 Ref: PEP 353 Using ssize_t as the index type-Footnote-11486890 Ref: PEP 353 Using ssize_t as the index type-Footnote-21486939 Node: PEP 357 The ‘__index__’ method1486988 Ref: whatsnew/2 5 pep-3571487168 Ref: d7f1487168 Ref: whatsnew/2 5 pep-357-the-index-method1487168 Ref: d801487168 Ref: PEP 357 The ‘__index__’ method-Footnote-11488896 Node: Other Language Changes<11>1488945 Ref: whatsnew/2 5 other-lang1489118 Ref: d821489118 Ref: whatsnew/2 5 other-language-changes1489118 Ref: d831489118 Ref: Other Language Changes<11>-Footnote-11496071 Node: Interactive Interpreter Changes1496120 Ref: whatsnew/2 5 interactive1496240 Ref: d891496240 Ref: whatsnew/2 5 interactive-interpreter-changes1496240 Ref: d8a1496240 Node: Optimizations<10>1497020 Ref: whatsnew/2 5 optimizations1497140 Ref: d8d1497140 Ref: whatsnew/2 5 opts1497140 Ref: d8e1497140 Node: New Improved and Removed Modules1500958 Ref: whatsnew/2 5 modules1501124 Ref: d8f1501124 Ref: whatsnew/2 5 new-improved-and-removed-modules1501124 Ref: d901501124 Ref: New Improved and Removed Modules-Footnote-11525616 Ref: New Improved and Removed Modules-Footnote-21525665 Ref: New Improved and Removed Modules-Footnote-31525714 Node: The ctypes package1525763 Ref: whatsnew/2 5 module-ctypes1525882 Ref: d9d1525882 Ref: whatsnew/2 5 the-ctypes-package1525882 Ref: d9e1525882 Node: The ElementTree package1529099 Ref: whatsnew/2 5 module-etree1529246 Ref: d9f1529246 Ref: whatsnew/2 5 the-elementtree-package1529246 Ref: da01529246 Node: The hashlib package1534458 Ref: whatsnew/2 5 module-hashlib1534606 Ref: da11534606 Ref: whatsnew/2 5 the-hashlib-package1534606 Ref: da21534606 Node: The sqlite3 package1536191 Ref: whatsnew/2 5 module-sqlite1536335 Ref: da31536335 Ref: whatsnew/2 5 the-sqlite3-package1536335 Ref: da41536335 Ref: The sqlite3 package-Footnote-11540344 Ref: The sqlite3 package-Footnote-21540393 Node: The wsgiref package1540442 Ref: whatsnew/2 5 module-wsgiref1540558 Ref: da51540558 Ref: whatsnew/2 5 the-wsgiref-package1540558 Ref: da61540558 Ref: The wsgiref package-Footnote-11541479 Ref: The wsgiref package-Footnote-21541528 Node: Build and C API Changes<10>1541577 Ref: whatsnew/2 5 build-and-c-api-changes1541738 Ref: da71541738 Ref: whatsnew/2 5 build-api1541738 Ref: da81541738 Ref: Build and C API Changes<10>-Footnote-11548757 Ref: Build and C API Changes<10>-Footnote-21548806 Ref: Build and C API Changes<10>-Footnote-31548855 Node: Port-Specific Changes1548904 Ref: whatsnew/2 5 port-specific-changes1548989 Ref: db21548989 Ref: whatsnew/2 5 ports1548989 Ref: db31548989 Ref: Port-Specific Changes-Footnote-11549666 Node: Porting to Python 2 51549708 Ref: whatsnew/2 5 porting1549856 Ref: db41549856 Ref: whatsnew/2 5 porting-to-python-2-51549856 Ref: db51549856 Ref: Porting to Python 2 5-Footnote-11552679 Node: Acknowledgements<3>1552728 Ref: whatsnew/2 5 acknowledgements1552840 Ref: db61552840 Node: What’s New in Python 2 41553334 Ref: whatsnew/2 4 doc1553489 Ref: db71553489 Ref: whatsnew/2 4 what-s-new-in-python-2-41553489 Ref: db81553489 Node: PEP 218 Built-In Set Objects1555594 Ref: whatsnew/2 4 pep-218-built-in-set-objects1555737 Ref: db91555737 Ref: PEP 218 Built-In Set Objects-Footnote-11557973 Node: PEP 237 Unifying Long Integers and Integers1558022 Ref: whatsnew/2 4 pep-237-unifying-long-integers-and-integers1558203 Ref: dba1558203 Ref: PEP 237 Unifying Long Integers and Integers-Footnote-11559244 Node: PEP 289 Generator Expressions1559293 Ref: whatsnew/2 4 pep-289-generator-expressions1559482 Ref: dbb1559482 Ref: PEP 289 Generator Expressions-Footnote-11561754 Node: PEP 292 Simpler String Substitutions1561803 Ref: whatsnew/2 4 pep-292-simpler-string-substitutions1561993 Ref: dbc1561993 Ref: PEP 292 Simpler String Substitutions-Footnote-11563792 Node: PEP 318 Decorators for Functions and Methods1563841 Ref: whatsnew/2 4 pep-318-decorators-for-functions-and-methods1564027 Ref: dbd1564027 Ref: PEP 318 Decorators for Functions and Methods-Footnote-11568548 Ref: PEP 318 Decorators for Functions and Methods-Footnote-21568597 Node: PEP 322 Reverse Iteration1568646 Ref: whatsnew/2 4 pep-322-reverse-iteration1568825 Ref: dbf1568825 Ref: PEP 322 Reverse Iteration-Footnote-11569787 Node: PEP 324 New subprocess Module1569836 Ref: whatsnew/2 4 pep-324-new-subprocess-module1569996 Ref: dc01569996 Ref: PEP 324 New subprocess Module-Footnote-11573760 Node: PEP 327 Decimal Data Type1573809 Ref: whatsnew/2 4 pep-327-decimal-data-type1573970 Ref: dc21573970 Node: Why is Decimal needed?1574548 Ref: whatsnew/2 4 why-is-decimal-needed1574657 Ref: dc31574657 Node: The Decimal type1577247 Ref: whatsnew/2 4 the-decimal-type1577381 Ref: dc41577381 Node: The Context type1580553 Ref: whatsnew/2 4 the-context-type1580656 Ref: dc51580656 Ref: The Context type-Footnote-11583265 Node: PEP 328 Multi-line Imports1583314 Ref: whatsnew/2 4 pep-328-multi-line-imports1583497 Ref: dc61583497 Ref: PEP 328 Multi-line Imports-Footnote-11584991 Node: PEP 331 Locale-Independent Float/String Conversions1585040 Ref: whatsnew/2 4 pep-331-locale-independent-float-string-conversions1585224 Ref: dc71585224 Ref: PEP 331 Locale-Independent Float/String Conversions-Footnote-11586964 Node: Other Language Changes<12>1587013 Ref: whatsnew/2 4 other-language-changes1587209 Ref: dc81587209 Ref: Other Language Changes<12>-Footnote-11594191 Ref: Other Language Changes<12>-Footnote-21594240 Ref: Other Language Changes<12>-Footnote-31594289 Ref: Other Language Changes<12>-Footnote-41594338 Ref: Other Language Changes<12>-Footnote-51594387 Ref: Other Language Changes<12>-Footnote-61594436 Node: Optimizations<11>1594485 Ref: whatsnew/2 4 optimizations1594565 Ref: dca1594565 Node: New Improved and Deprecated Modules<3>1597320 Ref: whatsnew/2 4 new-improved-and-deprecated-modules1597492 Ref: dcc1597492 Ref: New Improved and Deprecated Modules<3>-Footnote-11614779 Node: cookielib1614828 Ref: whatsnew/2 4 cookielib1614931 Ref: dce1614931 Node: doctest<3>1615850 Ref: whatsnew/2 4 doctest1615953 Ref: dcf1615953 Node: Build and C API Changes<11>1618687 Ref: whatsnew/2 4 build-and-c-api-changes1618854 Ref: dd51618854 Node: Port-Specific Changes<2>1621480 Ref: whatsnew/2 4 port-specific-changes1621568 Ref: ddc1621568 Node: Porting to Python 2 41621747 Ref: whatsnew/2 4 porting-to-python-2-41621895 Ref: ddd1621895 Node: Acknowledgements<4>1623863 Ref: whatsnew/2 4 acknowledgements1623975 Ref: ddf1623975 Ref: whatsnew/2 4 acks1623975 Ref: de01623975 Node: What’s New in Python 2 31624308 Ref: whatsnew/2 3 doc1624463 Ref: de11624463 Ref: whatsnew/2 3 what-s-new-in-python-2-31624463 Ref: de21624463 Node: PEP 218 A Standard Set Datatype1627481 Ref: whatsnew/2 3 pep-218-a-standard-set-datatype1627609 Ref: de41627609 Ref: PEP 218 A Standard Set Datatype-Footnote-11630100 Node: PEP 255 Simple Generators1630149 Ref: whatsnew/2 3 pep-255-simple-generators1630315 Ref: de51630315 Ref: whatsnew/2 3 section-generators1630315 Ref: de61630315 Ref: PEP 255 Simple Generators-Footnote-11636497 Ref: PEP 255 Simple Generators-Footnote-21636546 Node: PEP 263 Source Code Encodings1636595 Ref: whatsnew/2 3 pep-263-source-code-encodings1636773 Ref: de81636773 Ref: whatsnew/2 3 section-encodings1636773 Ref: de91636773 Ref: PEP 263 Source Code Encodings-Footnote-11637985 Node: PEP 273 Importing Modules from ZIP Archives1638034 Ref: whatsnew/2 3 pep-273-importing-modules-from-zip-archives1638235 Ref: dea1638235 Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-11640268 Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-21640317 Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-31640366 Node: PEP 277 Unicode file name support for Windows NT1640415 Ref: whatsnew/2 3 pep-277-unicode-file-name-support-for-windows-nt1640620 Ref: dec1640620 Ref: PEP 277 Unicode file name support for Windows NT-Footnote-11642098 Node: PEP 278 Universal Newline Support1642147 Ref: whatsnew/2 3 pep-278-universal-newline-support1642326 Ref: dee1642326 Ref: PEP 278 Universal Newline Support-Footnote-11643841 Node: PEP 279 enumerate1643890 Ref: whatsnew/2 3 pep-279-enumerate1644048 Ref: def1644048 Ref: whatsnew/2 3 section-enumerate1644048 Ref: df01644048 Ref: PEP 279 enumerate-Footnote-11644904 Node: PEP 282 The logging Package1644953 Ref: whatsnew/2 3 pep-282-the-logging-package1645100 Ref: df11645100 Ref: PEP 282 The logging Package-Footnote-11649794 Ref: PEP 282 The logging Package-Footnote-21649843 Node: PEP 285 A Boolean Type1649892 Ref: whatsnew/2 3 pep-285-a-boolean-type1650060 Ref: df21650060 Ref: whatsnew/2 3 section-bool1650060 Ref: df31650060 Ref: PEP 285 A Boolean Type-Footnote-11652509 Ref: PEP 285 A Boolean Type-Footnote-21652558 Node: PEP 293 Codec Error Handling Callbacks1652607 Ref: whatsnew/2 3 pep-293-codec-error-handling-callbacks1652796 Ref: df41652796 Ref: PEP 293 Codec Error Handling Callbacks-Footnote-11654345 Node: PEP 301 Package Index and Metadata for Distutils1654394 Ref: whatsnew/2 3 pep-301-package-index-and-metadata-for-distutils1654585 Ref: df71654585 Ref: whatsnew/2 3 section-pep3011654585 Ref: df81654585 Ref: PEP 301 Package Index and Metadata for Distutils-Footnote-11656229 Ref: PEP 301 Package Index and Metadata for Distutils-Footnote-21656265 Node: PEP 302 New Import Hooks1656314 Ref: whatsnew/2 3 pep-302-new-import-hooks1656496 Ref: df91656496 Ref: whatsnew/2 3 section-pep3021656496 Ref: deb1656496 Ref: PEP 302 New Import Hooks-Footnote-11659103 Ref: PEP 302 New Import Hooks-Footnote-21659152 Ref: PEP 302 New Import Hooks-Footnote-31659201 Node: PEP 305 Comma-separated Files1659250 Ref: whatsnew/2 3 pep-305-comma-separated-files1659411 Ref: dfa1659411 Ref: whatsnew/2 3 section-pep3051659411 Ref: dfb1659411 Ref: PEP 305 Comma-separated Files-Footnote-11660887 Node: PEP 307 Pickle Enhancements1660936 Ref: whatsnew/2 3 pep-307-pickle-enhancements1661088 Ref: dfd1661088 Ref: whatsnew/2 3 section-pep3071661088 Ref: dfe1661088 Ref: PEP 307 Pickle Enhancements-Footnote-11663059 Ref: PEP 307 Pickle Enhancements-Footnote-21663108 Ref: PEP 307 Pickle Enhancements-Footnote-31663157 Node: Extended Slices1663206 Ref: whatsnew/2 3 extended-slices1663355 Ref: e021663355 Ref: whatsnew/2 3 section-slices1663355 Ref: e031663355 Node: Other Language Changes<13>1666747 Ref: whatsnew/2 3 other-language-changes1666907 Ref: e051666907 Ref: Other Language Changes<13>-Footnote-11674691 Ref: Other Language Changes<13>-Footnote-21674763 Node: String Changes1674817 Ref: whatsnew/2 3 string-changes1674920 Ref: e0b1674920 Node: Optimizations<12>1677373 Ref: whatsnew/2 3 optimizations1677476 Ref: e0c1677476 Node: New Improved and Deprecated Modules<4>1678923 Ref: whatsnew/2 3 new-improved-and-deprecated-modules1679107 Ref: e0e1679107 Ref: New Improved and Deprecated Modules<4>-Footnote-11703711 Node: Date/Time Type1703750 Ref: whatsnew/2 3 date-time-type1703867 Ref: e121703867 Node: The optparse Module1706131 Ref: whatsnew/2 3 the-optparse-module1706248 Ref: e131706248 Node: Pymalloc A Specialized Object Allocator1708308 Ref: whatsnew/2 3 pymalloc-a-specialized-object-allocator1708493 Ref: e141708493 Ref: whatsnew/2 3 section-pymalloc1708493 Ref: e151708493 Node: Build and C API Changes<12>1712395 Ref: whatsnew/2 3 build-and-c-api-changes1712568 Ref: e171712568 Node: Port-Specific Changes<3>1715990 Ref: whatsnew/2 3 port-specific-changes1716078 Ref: e1c1716078 Node: Other Changes and Fixes<2>1717313 Ref: whatsnew/2 3 other-changes-and-fixes1717468 Ref: e1d1717468 Ref: whatsnew/2 3 section-other1717468 Ref: e0d1717468 Node: Porting to Python 2 31719958 Ref: whatsnew/2 3 porting-to-python-2-31720105 Ref: e201720105 Node: Acknowledgements<5>1722913 Ref: whatsnew/2 3 acknowledgements1723025 Ref: e211723025 Ref: whatsnew/2 3 acks1723025 Ref: e221723025 Node: What’s New in Python 2 21723646 Ref: whatsnew/2 2 doc1723801 Ref: e231723801 Ref: whatsnew/2 2 what-s-new-in-python-2-21723801 Ref: e241723801 Node: Introduction1724536 Ref: whatsnew/2 2 introduction1724659 Ref: e251724659 Ref: Introduction-Footnote-11725631 Ref: Introduction-Footnote-21725680 Node: PEPs 252 and 253 Type and Class Changes1725729 Ref: whatsnew/2 2 peps-252-and-253-type-and-class-changes1725878 Ref: e261725878 Node: Old and New Classes1729310 Ref: whatsnew/2 2 old-and-new-classes1729425 Ref: e281729425 Ref: Old and New Classes-Footnote-11731830 Node: Descriptors1731879 Ref: whatsnew/2 2 descriptors1732040 Ref: e291732040 Node: Multiple Inheritance The Diamond Rule1735900 Ref: whatsnew/2 2 multiple-inheritance-the-diamond-rule1736058 Ref: e2a1736058 Ref: Multiple Inheritance The Diamond Rule-Footnote-11738943 Node: Attribute Access1738992 Ref: whatsnew/2 2 attribute-access1739152 Ref: e2b1739152 Node: Related Links1742969 Ref: whatsnew/2 2 related-links1743083 Ref: e2e1743083 Ref: whatsnew/2 2 sect-rellinks1743083 Ref: e271743083 Ref: Related Links-Footnote-11744584 Ref: Related Links-Footnote-21744633 Ref: Related Links-Footnote-31744682 Ref: Related Links-Footnote-41744731 Ref: Related Links-Footnote-51744780 Node: PEP 234 Iterators1744829 Ref: whatsnew/2 2 pep-234-iterators1744994 Ref: e2f1744994 Ref: PEP 234 Iterators-Footnote-11749882 Node: PEP 255 Simple Generators<2>1749931 Ref: whatsnew/2 2 pep-255-simple-generators1750103 Ref: e321750103 Ref: PEP 255 Simple Generators<2>-Footnote-11756160 Ref: PEP 255 Simple Generators<2>-Footnote-21756209 Node: PEP 237 Unifying Long Integers and Integers<2>1756258 Ref: whatsnew/2 2 pep-237-unifying-long-integers-and-integers1756451 Ref: e331756451 Ref: PEP 237 Unifying Long Integers and Integers<2>-Footnote-11758176 Node: PEP 238 Changing the Division Operator1758225 Ref: whatsnew/2 2 pep-238-changing-the-division-operator1758405 Ref: e341758405 Ref: PEP 238 Changing the Division Operator-Footnote-11762057 Ref: PEP 238 Changing the Division Operator-Footnote-21762106 Ref: PEP 238 Changing the Division Operator-Footnote-31762155 Node: Unicode Changes1762204 Ref: whatsnew/2 2 unicode-changes1762359 Ref: e361762359 Ref: Unicode Changes-Footnote-11764996 Ref: Unicode Changes-Footnote-21765045 Node: PEP 227 Nested Scopes1765094 Ref: whatsnew/2 2 pep-227-nested-scopes1765238 Ref: e381765238 Ref: PEP 227 Nested Scopes-Footnote-11769580 Node: New and Improved Modules<3>1769629 Ref: whatsnew/2 2 new-and-improved-modules1769787 Ref: e391769787 Ref: New and Improved Modules<3>-Footnote-11776417 Ref: New and Improved Modules<3>-Footnote-21776466 Ref: New and Improved Modules<3>-Footnote-31776515 Ref: New and Improved Modules<3>-Footnote-41776564 Ref: New and Improved Modules<3>-Footnote-51776613 Node: Interpreter Changes and Fixes1776661 Ref: whatsnew/2 2 interpreter-changes-and-fixes1776824 Ref: e3a1776824 Node: Other Changes and Fixes<3>1781581 Ref: whatsnew/2 2 other-changes-and-fixes1781736 Ref: e4c1781736 Ref: Other Changes and Fixes<3>-Footnote-11788402 Node: Acknowledgements<6>1788451 Ref: whatsnew/2 2 acknowledgements1788568 Ref: e4f1788568 Node: What’s New in Python 2 11789169 Ref: whatsnew/2 1 doc1789324 Ref: e501789324 Ref: whatsnew/2 1 what-s-new-in-python-2-11789324 Ref: e511789324 Node: Introduction<2>1790329 Ref: whatsnew/2 1 introduction1790440 Ref: e521790440 Node: PEP 227 Nested Scopes<2>1791536 Ref: whatsnew/2 1 pep-227-nested-scopes1791685 Ref: e531791685 Ref: PEP 227 Nested Scopes<2>-Footnote-11796046 Ref: PEP 227 Nested Scopes<2>-Footnote-21796095 Ref: PEP 227 Nested Scopes<2>-Footnote-31796144 Node: PEP 236 __future__ Directives1796193 Ref: whatsnew/2 1 pep-236-future-directives1796351 Ref: e541796351 Ref: PEP 236 __future__ Directives-Footnote-11797588 Node: PEP 207 Rich Comparisons1797637 Ref: whatsnew/2 1 pep-207-rich-comparisons1797796 Ref: e551797796 Ref: PEP 207 Rich Comparisons-Footnote-11801191 Ref: PEP 207 Rich Comparisons-Footnote-21801240 Node: PEP 230 Warning Framework1801289 Ref: whatsnew/2 1 pep-230-warning-framework1801443 Ref: e571801443 Ref: PEP 230 Warning Framework-Footnote-11804723 Ref: PEP 230 Warning Framework-Footnote-21804772 Node: PEP 229 New Build System1804821 Ref: whatsnew/2 1 pep-229-new-build-system1804974 Ref: e591804974 Ref: PEP 229 New Build System-Footnote-11806894 Node: PEP 205 Weak References1806943 Ref: whatsnew/2 1 pep-205-weak-references1807098 Ref: e5a1807098 Ref: PEP 205 Weak References-Footnote-11810211 Node: PEP 232 Function Attributes1810260 Ref: whatsnew/2 1 pep-232-function-attributes1810446 Ref: e5b1810446 Ref: PEP 232 Function Attributes-Footnote-11811957 Node: PEP 235 Importing Modules on Case-Insensitive Platforms1812006 Ref: whatsnew/2 1 pep-235-importing-modules-on-case-insensitive-platforms1812201 Ref: e5c1812201 Node: PEP 217 Interactive Display Hook1813104 Ref: whatsnew/2 1 pep-217-interactive-display-hook1813298 Ref: e5e1813298 Ref: PEP 217 Interactive Display Hook-Footnote-11814226 Node: PEP 208 New Coercion Model1814275 Ref: whatsnew/2 1 pep-208-new-coercion-model1814449 Ref: e601814449 Ref: PEP 208 New Coercion Model-Footnote-11816071 Node: PEP 241 Metadata in Python Packages1816120 Ref: whatsnew/2 1 pep-241-metadata-in-python-packages1816289 Ref: e611816289 Ref: PEP 241 Metadata in Python Packages-Footnote-11818332 Ref: PEP 241 Metadata in Python Packages-Footnote-21818381 Ref: PEP 241 Metadata in Python Packages-Footnote-31818430 Ref: PEP 241 Metadata in Python Packages-Footnote-41818479 Node: New and Improved Modules<4>1818528 Ref: whatsnew/2 1 new-and-improved-modules1818697 Ref: e621818697 Node: Other Changes and Fixes<4>1824530 Ref: whatsnew/2 1 other-changes-and-fixes1824683 Ref: e651824683 Node: Acknowledgements<7>1830617 Ref: whatsnew/2 1 acknowledgements1830734 Ref: e661830734 Node: What’s New in Python 2 01831025 Ref: whatsnew/2 0 doc1831163 Ref: e671831163 Ref: whatsnew/2 0 what-s-new-in-python-2-01831163 Ref: e681831163 Node: Introduction<3>1831836 Ref: whatsnew/2 0 introduction1831945 Ref: e691831945 Node: What About Python 1 6?1832829 Ref: whatsnew/2 0 what-about-python-1-61832970 Ref: e6a1832970 Node: New Development Process1834211 Ref: whatsnew/2 0 new-development-process1834347 Ref: e6b1834347 Ref: New Development Process-Footnote-11839495 Ref: New Development Process-Footnote-21839544 Ref: New Development Process-Footnote-31839593 Node: Unicode<2>1839642 Ref: whatsnew/2 0 unicode1839775 Ref: e6c1839775 Ref: Unicode<2>-Footnote-11845949 Node: List Comprehensions1845998 Ref: whatsnew/2 0 list-comprehensions1846128 Ref: e6d1846128 Node: Augmented Assignment1849859 Ref: whatsnew/2 0 augmented-assignment1849993 Ref: e6e1849993 Node: String Methods1851539 Ref: whatsnew/2 0 string-methods1851682 Ref: e711851682 Node: Garbage Collection of Cycles1853535 Ref: whatsnew/2 0 garbage-collection-of-cycles1853676 Ref: e721853676 Node: Other Core Changes1857023 Ref: whatsnew/2 0 other-core-changes1857164 Ref: e731857164 Node: Minor Language Changes1857449 Ref: whatsnew/2 0 minor-language-changes1857564 Ref: e741857564 Node: Changes to Built-in Functions1862651 Ref: whatsnew/2 0 changes-to-built-in-functions1862766 Ref: e791862766 Node: Porting to 2 01865056 Ref: whatsnew/2 0 porting-to-2-01865196 Ref: e7c1865196 Node: Extending/Embedding Changes1870515 Ref: whatsnew/2 0 extending-embedding-changes1870677 Ref: e7d1870677 Node: Distutils Making Modules Easy to Install1874499 Ref: whatsnew/2 0 distutils-making-modules-easy-to-install1874658 Ref: e7e1874658 Node: XML Modules1878024 Ref: whatsnew/2 0 xml-modules1878170 Ref: e7f1878170 Node: SAX2 Support1879069 Ref: whatsnew/2 0 sax2-support1879149 Ref: e801879149 Node: DOM Support1880787 Ref: whatsnew/2 0 dom-support1880897 Ref: e811880897 Node: Relationship to PyXML1883725 Ref: whatsnew/2 0 relationship-to-pyxml1883814 Ref: e821883814 Node: Module changes1885104 Ref: whatsnew/2 0 module-changes1885221 Ref: e831885221 Node: New modules1887693 Ref: whatsnew/2 0 new-modules1887816 Ref: e841887816 Node: IDLE Improvements1891808 Ref: whatsnew/2 0 idle-improvements1891947 Ref: e861891947 Node: Deleted and Deprecated Modules1893070 Ref: whatsnew/2 0 deleted-and-deprecated-modules1893217 Ref: e871893217 Node: Acknowledgements<8>1893969 Ref: whatsnew/2 0 acknowledgements1894090 Ref: e881894090 Ref: Acknowledgements<8>-Footnote-11894689 Ref: Acknowledgements<8>-Footnote-21894728 Node: Changelog1894791 Ref: whatsnew/changelog doc1894894 Ref: e891894894 Ref: whatsnew/changelog changelog1894894 Ref: 14c1894894 Ref: whatsnew/changelog id11894894 Ref: e8a1894894 Node: The Python Tutorial1894960 Ref: tutorial/index doc1895081 Ref: e8b1895081 Ref: tutorial/index the-python-tutorial1895081 Ref: e8c1895081 Ref: tutorial/index tutorial-index1895081 Ref: e8d1895081 Node: Whetting Your Appetite1897802 Ref: tutorial/appetite doc1897917 Ref: e931897917 Ref: tutorial/appetite tut-intro1897917 Ref: e941897917 Ref: tutorial/appetite whetting-your-appetite1897917 Ref: e951897917 Node: Using the Python Interpreter1902435 Ref: tutorial/interpreter doc1902593 Ref: e961902593 Ref: tutorial/interpreter tut-using1902593 Ref: e971902593 Ref: tutorial/interpreter using-the-python-interpreter1902593 Ref: e981902593 Node: Invoking the Interpreter1902739 Ref: tutorial/interpreter invoking-the-interpreter1902872 Ref: e991902872 Ref: tutorial/interpreter tut-invoking1902872 Ref: e9a1902872 Ref: Invoking the Interpreter-Footnote-11905876 Ref: Invoking the Interpreter-Footnote-21906076 Node: Argument Passing1906137 Ref: tutorial/interpreter argument-passing1906239 Ref: ea01906239 Ref: tutorial/interpreter tut-argpassing1906239 Ref: ea11906239 Node: Interactive Mode1907147 Ref: tutorial/interpreter interactive-mode1907249 Ref: ea21907249 Ref: tutorial/interpreter tut-interactive1907249 Ref: 8e31907249 Node: The Interpreter and Its Environment1908263 Ref: tutorial/interpreter the-interpreter-and-its-environment1908396 Ref: ea41908396 Ref: tutorial/interpreter tut-interp1908396 Ref: ea51908396 Node: Source Code Encoding1908516 Ref: tutorial/interpreter source-code-encoding1908608 Ref: ea61908608 Ref: tutorial/interpreter tut-source-encoding1908608 Ref: ea71908608 Node: An Informal Introduction to Python1909843 Ref: tutorial/introduction doc1910002 Ref: ea91910002 Ref: tutorial/introduction an-informal-introduction-to-python1910002 Ref: eaa1910002 Ref: tutorial/introduction tut-informal1910002 Ref: eab1910002 Node: Using Python as a Calculator1911305 Ref: tutorial/introduction tut-calculator1911444 Ref: eae1911444 Ref: tutorial/introduction using-python-as-a-calculator1911444 Ref: eaf1911444 Node: Numbers1911697 Ref: tutorial/introduction numbers1911785 Ref: eb01911785 Ref: tutorial/introduction tut-numbers1911785 Ref: eb11911785 Ref: Numbers-Footnote-11914793 Node: Strings1914993 Ref: tutorial/introduction strings1915095 Ref: eb41915095 Ref: tutorial/introduction tut-strings1915095 Ref: eb51915095 Ref: Strings-Footnote-11923047 Node: Lists1923355 Ref: tutorial/introduction lists1923441 Ref: eba1923441 Ref: tutorial/introduction tut-lists1923441 Ref: ebb1923441 Node: First Steps Towards Programming1926038 Ref: tutorial/introduction first-steps-towards-programming1926177 Ref: ebf1926177 Ref: tutorial/introduction tut-firststeps1926177 Ref: ec01926177 Ref: First Steps Towards Programming-Footnote-11929274 Node: More Control Flow Tools1929329 Ref: tutorial/controlflow doc1929475 Ref: ec21929475 Ref: tutorial/controlflow more-control-flow-tools1929475 Ref: ec31929475 Ref: tutorial/controlflow tut-morecontrol1929475 Ref: ec41929475 Node: if Statements1930017 Ref: tutorial/controlflow if-statements1930113 Ref: ec51930113 Ref: tutorial/controlflow tut-if1930113 Ref: ec61930113 Node: for Statements1930928 Ref: tutorial/controlflow for-statements1931051 Ref: ec91931051 Ref: tutorial/controlflow tut-for1931051 Ref: eca1931051 Node: The range Function1932300 Ref: tutorial/controlflow the-range-function1932465 Ref: ecb1932465 Ref: tutorial/controlflow tut-range1932465 Ref: ecc1932465 Node: break and continue Statements and else Clauses on Loops1934718 Ref: tutorial/controlflow break-and-continue-statements-and-else-clauses-on-loops1934884 Ref: ecf1934884 Ref: tutorial/controlflow tut-break1934884 Ref: ed01934884 Node: pass Statements1937087 Ref: tutorial/controlflow pass-statements1937253 Ref: ed21937253 Ref: tutorial/controlflow tut-pass1937253 Ref: ed31937253 Node: Defining Functions1937980 Ref: tutorial/controlflow defining-functions1938117 Ref: ed51938117 Ref: tutorial/controlflow tut-functions1938117 Ref: ed61938117 Ref: Defining Functions-Footnote-11943122 Node: More on Defining Functions1943324 Ref: tutorial/controlflow more-on-defining-functions1943469 Ref: eda1943469 Ref: tutorial/controlflow tut-defining1943469 Ref: edb1943469 Node: Default Argument Values1943876 Ref: tutorial/controlflow default-argument-values1943988 Ref: edc1943988 Ref: tutorial/controlflow tut-defaultargs1943988 Ref: edd1943988 Node: Keyword Arguments1945999 Ref: tutorial/controlflow keyword-arguments1946138 Ref: ede1946138 Ref: tutorial/controlflow tut-keywordargs1946138 Ref: edf1946138 Node: Special parameters1949884 Ref: tutorial/controlflow special-parameters1950024 Ref: ee11950024 Node: Positional-or-Keyword Arguments1951161 Ref: tutorial/controlflow positional-or-keyword-arguments1951282 Ref: ee21951282 Node: Positional-Only Parameters1951496 Ref: tutorial/controlflow positional-only-parameters1951648 Ref: ee31951648 Node: Keyword-Only Arguments1952282 Ref: tutorial/controlflow keyword-only-arguments1952420 Ref: ee41952420 Node: Function Examples1952671 Ref: tutorial/controlflow function-examples1952788 Ref: ee51952788 Node: Recap1955784 Ref: tutorial/controlflow recap1955870 Ref: ee61955870 Node: Arbitrary Argument Lists1956731 Ref: tutorial/controlflow arbitrary-argument-lists1956878 Ref: ee71956878 Ref: tutorial/controlflow tut-arbitraryargs1956878 Ref: ee81956878 Node: Unpacking Argument Lists1957917 Ref: tutorial/controlflow tut-unpacking-arguments1958064 Ref: ee91958064 Ref: tutorial/controlflow unpacking-argument-lists1958064 Ref: eea1958064 Node: Lambda Expressions1959297 Ref: tutorial/controlflow lambda-expressions1959441 Ref: eeb1959441 Ref: tutorial/controlflow tut-lambda1959441 Ref: eec1959441 Node: Documentation Strings1960432 Ref: tutorial/controlflow documentation-strings1960572 Ref: eed1960572 Ref: tutorial/controlflow tut-docstrings1960572 Ref: ed71960572 Node: Function Annotations1962502 Ref: tutorial/controlflow function-annotations1962615 Ref: eee1962615 Ref: tutorial/controlflow tut-annotations1962615 Ref: eef1962615 Ref: Function Annotations-Footnote-11963828 Ref: Function Annotations-Footnote-21963877 Node: Intermezzo Coding Style1963926 Ref: tutorial/controlflow intermezzo-coding-style1964044 Ref: ef21964044 Ref: tutorial/controlflow tut-codingstyle1964044 Ref: ef31964044 Ref: Intermezzo Coding Style-Footnote-11966201 Node: Data Structures1966250 Ref: tutorial/datastructures doc1966369 Ref: ef51966369 Ref: tutorial/datastructures data-structures1966369 Ref: ef61966369 Ref: tutorial/datastructures tut-structures1966369 Ref: ece1966369 Node: More on Lists1966714 Ref: tutorial/datastructures more-on-lists1966805 Ref: ef71966805 Ref: tutorial/datastructures tut-morelists1966805 Ref: ef81966805 Ref: More on Lists-Footnote-11970673 Node: Using Lists as Stacks1970814 Ref: tutorial/datastructures tut-lists-as-stacks1970915 Ref: ef91970915 Ref: tutorial/datastructures using-lists-as-stacks1970915 Ref: efa1970915 Node: Using Lists as Queues1971549 Ref: tutorial/datastructures tut-lists-as-queues1971681 Ref: efb1971681 Ref: tutorial/datastructures using-lists-as-queues1971681 Ref: efc1971681 Node: List Comprehensions<2>1972745 Ref: tutorial/datastructures list-comprehensions1972882 Ref: efd1972882 Ref: tutorial/datastructures tut-listcomps1972882 Ref: efe1972882 Node: Nested List Comprehensions1976095 Ref: tutorial/datastructures nested-list-comprehensions1976202 Ref: eff1976202 Node: The del statement1977850 Ref: tutorial/datastructures the-del-statement1977970 Ref: f001977970 Ref: tutorial/datastructures tut-del1977970 Ref: f011977970 Node: Tuples and Sequences1978819 Ref: tutorial/datastructures tuples-and-sequences1978930 Ref: f031978930 Ref: tutorial/datastructures tut-tuples1978930 Ref: ee01978930 Node: Sets1981961 Ref: tutorial/datastructures sets1982067 Ref: f051982067 Ref: tutorial/datastructures tut-sets1982067 Ref: f061982067 Node: Dictionaries1983807 Ref: tutorial/datastructures dictionaries1983911 Ref: f071983911 Ref: tutorial/datastructures tut-dictionaries1983911 Ref: f081983911 Node: Looping Techniques1986732 Ref: tutorial/datastructures looping-techniques1986850 Ref: f091986850 Ref: tutorial/datastructures tut-loopidioms1986850 Ref: ecd1986850 Node: More on Conditions1989030 Ref: tutorial/datastructures more-on-conditions1989171 Ref: f0a1989171 Ref: tutorial/datastructures tut-conditions1989171 Ref: f0b1989171 Node: Comparing Sequences and Other Types1991273 Ref: tutorial/datastructures comparing-sequences-and-other-types1991387 Ref: f0d1991387 Ref: tutorial/datastructures tut-comparing1991387 Ref: f0e1991387 Node: Modules1992974 Ref: tutorial/modules doc1993086 Ref: f0f1993086 Ref: tutorial/modules modules1993086 Ref: f101993086 Ref: tutorial/modules tut-modules1993086 Ref: f111993086 Node: More on Modules1995639 Ref: tutorial/modules more-on-modules1995723 Ref: f121995723 Ref: tutorial/modules tut-moremodules1995723 Ref: f131995723 Ref: More on Modules-Footnote-11998839 Node: Executing modules as scripts1999047 Ref: tutorial/modules executing-modules-as-scripts1999158 Ref: f141999158 Ref: tutorial/modules tut-modulesasscripts1999158 Ref: f151999158 Node: The Module Search Path2000046 Ref: tutorial/modules the-module-search-path2000193 Ref: f162000193 Ref: tutorial/modules tut-searchpath2000193 Ref: f172000193 Node: “Compiled” Python files2001514 Ref: tutorial/modules compiled-python-files2001624 Ref: f192001624 Ref: “Compiled” Python files-Footnote-12003933 Node: Standard Modules2003982 Ref: tutorial/modules standard-modules2004091 Ref: f1a2004091 Ref: tutorial/modules tut-standardmodules2004091 Ref: f182004091 Node: The dir Function2005555 Ref: tutorial/modules the-dir-function2005657 Ref: f1b2005657 Ref: tutorial/modules tut-dir2005657 Ref: f1c2005657 Node: Packages2009822 Ref: tutorial/modules packages2009899 Ref: f1d2009899 Ref: tutorial/modules tut-packages2009899 Ref: f1e2009899 Node: Importing * From a Package2014202 Ref: tutorial/modules importing-from-a-package2014306 Ref: f1f2014306 Ref: tutorial/modules tut-pkg-import-star2014306 Ref: f202014306 Node: Intra-package References2016948 Ref: tutorial/modules intra-package-references2017093 Ref: f212017093 Node: Packages in Multiple Directories2018106 Ref: tutorial/modules packages-in-multiple-directories2018216 Ref: f222018216 Node: Input and Output2018744 Ref: tutorial/inputoutput doc2018862 Ref: f242018862 Ref: tutorial/inputoutput input-and-output2018862 Ref: f252018862 Ref: tutorial/inputoutput tut-io2018862 Ref: f262018862 Node: Fancier Output Formatting2019171 Ref: tutorial/inputoutput fancier-output-formatting2019283 Ref: f272019283 Ref: tutorial/inputoutput tut-formatting2019283 Ref: f282019283 Node: Formatted String Literals2023004 Ref: tutorial/inputoutput formatted-string-literals2023124 Ref: f2a2023124 Ref: tutorial/inputoutput tut-f-strings2023124 Ref: f292023124 Node: The String format Method2024686 Ref: tutorial/inputoutput the-string-format-method2024839 Ref: f2b2024839 Ref: tutorial/inputoutput tut-string-format2024839 Ref: f2c2024839 Node: Manual String Formatting2027507 Ref: tutorial/inputoutput manual-string-formatting2027656 Ref: f2e2027656 Node: Old string formatting2029181 Ref: tutorial/inputoutput old-string-formatting2029297 Ref: f332029297 Node: Reading and Writing Files2029847 Ref: tutorial/inputoutput reading-and-writing-files2029959 Ref: f342029959 Ref: tutorial/inputoutput tut-files2029959 Ref: f352029959 Node: Methods of File Objects2032968 Ref: tutorial/inputoutput methods-of-file-objects2033094 Ref: f362033094 Ref: tutorial/inputoutput tut-filemethods2033094 Ref: f372033094 Node: Saving structured data with json2036788 Ref: tutorial/inputoutput saving-structured-data-with-json2036914 Ref: f382036914 Ref: tutorial/inputoutput tut-json2036914 Ref: f392036914 Ref: Saving structured data with json-Footnote-12039557 Node: Errors and Exceptions2039581 Ref: tutorial/errors doc2039699 Ref: f3b2039699 Ref: tutorial/errors errors-and-exceptions2039699 Ref: f3c2039699 Ref: tutorial/errors tut-errors2039699 Ref: f3d2039699 Node: Syntax Errors2040155 Ref: tutorial/errors syntax-errors2040245 Ref: f3e2040245 Ref: tutorial/errors tut-syntaxerrors2040245 Ref: f3f2040245 Node: Exceptions2041048 Ref: tutorial/errors exceptions2041166 Ref: f402041166 Ref: tutorial/errors tut-exceptions2041166 Ref: f412041166 Node: Handling Exceptions2042999 Ref: tutorial/errors handling-exceptions2043122 Ref: f442043122 Ref: tutorial/errors tut-handling2043122 Ref: ed12043122 Node: Raising Exceptions2049018 Ref: tutorial/errors raising-exceptions2049154 Ref: f452049154 Ref: tutorial/errors tut-raising2049154 Ref: f462049154 Node: User-defined Exceptions2050296 Ref: tutorial/errors tut-userexceptions2050438 Ref: f472050438 Ref: tutorial/errors user-defined-exceptions2050438 Ref: f482050438 Node: Defining Clean-up Actions2052480 Ref: tutorial/errors defining-clean-up-actions2052631 Ref: f492052631 Ref: tutorial/errors tut-cleanup2052631 Ref: f4a2052631 Node: Predefined Clean-up Actions2055758 Ref: tutorial/errors predefined-clean-up-actions2055877 Ref: f4b2055877 Ref: tutorial/errors tut-cleanup-with2055877 Ref: f4c2055877 Node: Classes2056996 Ref: tutorial/classes doc2057132 Ref: f4d2057132 Ref: tutorial/classes classes2057132 Ref: f4e2057132 Ref: tutorial/classes tut-classes2057132 Ref: ed92057132 Node: A Word About Names and Objects2059445 Ref: tutorial/classes a-word-about-names-and-objects2059556 Ref: f502059556 Ref: tutorial/classes tut-object2059556 Ref: f512059556 Node: Python Scopes and Namespaces2060478 Ref: tutorial/classes python-scopes-and-namespaces2060621 Ref: f522060621 Ref: tutorial/classes tut-scopes2060621 Ref: f532060621 Ref: Python Scopes and Namespaces-Footnote-12066704 Node: Scopes and Namespaces Example2067098 Ref: tutorial/classes scopes-and-namespaces-example2067192 Ref: f552067192 Ref: tutorial/classes tut-scopeexample2067192 Ref: f562067192 Node: A First Look at Classes2068554 Ref: tutorial/classes a-first-look-at-classes2068681 Ref: f572068681 Ref: tutorial/classes tut-firstclasses2068681 Ref: ef42068681 Node: Class Definition Syntax2068966 Ref: tutorial/classes class-definition-syntax2069071 Ref: f582069071 Ref: tutorial/classes tut-classdefinition2069071 Ref: f592069071 Node: Class Objects2070607 Ref: tutorial/classes class-objects2070737 Ref: f5a2070737 Ref: tutorial/classes tut-classobjects2070737 Ref: f5b2070737 Node: Instance Objects2072938 Ref: tutorial/classes instance-objects2073059 Ref: f5c2073059 Ref: tutorial/classes tut-instanceobjects2073059 Ref: f5d2073059 Node: Method Objects2074723 Ref: tutorial/classes method-objects2074859 Ref: f5e2074859 Ref: tutorial/classes tut-methodobjects2074859 Ref: f5f2074859 Node: Class and Instance Variables2076800 Ref: tutorial/classes class-and-instance-variables2076911 Ref: f602076911 Ref: tutorial/classes tut-class-and-instance-variables2076911 Ref: f612076911 Node: Random Remarks2078953 Ref: tutorial/classes random-remarks2079063 Ref: f622079063 Ref: tutorial/classes tut-remarks2079063 Ref: f632079063 Node: Inheritance2082890 Ref: tutorial/classes inheritance2082994 Ref: f642082994 Ref: tutorial/classes tut-inheritance2082994 Ref: f652082994 Node: Multiple Inheritance2085763 Ref: tutorial/classes multiple-inheritance2085831 Ref: f662085831 Ref: tutorial/classes tut-multiple2085831 Ref: f672085831 Node: Private Variables2087832 Ref: tutorial/classes private-variables2087935 Ref: f682087935 Ref: tutorial/classes tut-private2087935 Ref: f4f2087935 Node: Odds and Ends2090623 Ref: tutorial/classes odds-and-ends2090724 Ref: f692090724 Ref: tutorial/classes tut-odds2090724 Ref: f6a2090724 Node: Iterators2091729 Ref: tutorial/classes iterators2091823 Ref: f6b2091823 Ref: tutorial/classes tut-iterators2091823 Ref: f6c2091823 Node: Generators2094105 Ref: tutorial/classes generators2094207 Ref: f6d2094207 Ref: tutorial/classes tut-generators2094207 Ref: f6e2094207 Node: Generator Expressions2095644 Ref: tutorial/classes generator-expressions2095728 Ref: f702095728 Ref: tutorial/classes tut-genexps2095728 Ref: f712095728 Node: Brief Tour of the Standard Library2096715 Ref: tutorial/stdlib doc2096876 Ref: f722096876 Ref: tutorial/stdlib brief-tour-of-the-standard-library2096876 Ref: f732096876 Ref: tutorial/stdlib tut-brieftour2096876 Ref: f742096876 Node: Operating System Interface2097273 Ref: tutorial/stdlib operating-system-interface2097393 Ref: f752097393 Ref: tutorial/stdlib tut-os-interface2097393 Ref: f762097393 Node: File Wildcards2098658 Ref: tutorial/stdlib file-wildcards2098809 Ref: f772098809 Ref: tutorial/stdlib tut-file-wildcards2098809 Ref: f782098809 Node: Command Line Arguments2099051 Ref: tutorial/stdlib command-line-arguments2099224 Ref: f792099224 Ref: tutorial/stdlib tut-command-line-arguments2099224 Ref: f7a2099224 Node: Error Output Redirection and Program Termination2100332 Ref: tutorial/stdlib error-output-redirection-and-program-termination2100514 Ref: f7b2100514 Ref: tutorial/stdlib tut-stderr2100514 Ref: f7c2100514 Node: String Pattern Matching2101037 Ref: tutorial/stdlib string-pattern-matching2101208 Ref: f7d2101208 Ref: tutorial/stdlib tut-string-pattern-matching2101208 Ref: f7e2101208 Node: Mathematics2101847 Ref: tutorial/stdlib mathematics2101985 Ref: f7f2101985 Ref: tutorial/stdlib tut-mathematics2101985 Ref: f802101985 Node: Internet Access2103133 Ref: tutorial/stdlib internet-access2103263 Ref: f812103263 Ref: tutorial/stdlib tut-internet-access2103263 Ref: f822103263 Node: Dates and Times2104286 Ref: tutorial/stdlib dates-and-times2104421 Ref: f832104421 Ref: tutorial/stdlib tut-dates-and-times2104421 Ref: f842104421 Node: Data Compression2105242 Ref: tutorial/stdlib data-compression2105385 Ref: f852105385 Ref: tutorial/stdlib tut-data-compression2105385 Ref: f862105385 Node: Performance Measurement2105908 Ref: tutorial/stdlib performance-measurement2106051 Ref: f872106051 Ref: tutorial/stdlib tut-performance-measurement2106051 Ref: f882106051 Node: Quality Control2106926 Ref: tutorial/stdlib quality-control2107071 Ref: f892107071 Ref: tutorial/stdlib tut-quality-control2107071 Ref: f8a2107071 Node: Batteries Included2108639 Ref: tutorial/stdlib batteries-included2108752 Ref: f8b2108752 Ref: tutorial/stdlib tut-batteries-included2108752 Ref: f8c2108752 Ref: Batteries Included-Footnote-12110564 Node: Brief Tour of the Standard Library — Part II2110613 Ref: tutorial/stdlib2 doc2110800 Ref: f8d2110800 Ref: tutorial/stdlib2 brief-tour-of-the-standard-library-part-ii2110800 Ref: f8e2110800 Ref: tutorial/stdlib2 tut-brieftourtwo2110800 Ref: f8f2110800 Node: Output Formatting2111274 Ref: tutorial/stdlib2 output-formatting2111393 Ref: f902111393 Ref: tutorial/stdlib2 tut-output-formatting2111393 Ref: f912111393 Node: Templating2113506 Ref: tutorial/stdlib2 templating2113673 Ref: f922113673 Ref: tutorial/stdlib2 tut-templating2113673 Ref: f932113673 Node: Working with Binary Data Record Layouts2116227 Ref: tutorial/stdlib2 tut-binary-formats2116395 Ref: f962116395 Ref: tutorial/stdlib2 working-with-binary-data-record-layouts2116395 Ref: f972116395 Node: Multi-threading<2>2117569 Ref: tutorial/stdlib2 multi-threading2117734 Ref: f992117734 Ref: tutorial/stdlib2 tut-multi-threading2117734 Ref: f9a2117734 Node: Logging2119677 Ref: tutorial/stdlib2 logging2119818 Ref: f9b2119818 Ref: tutorial/stdlib2 tut-logging2119818 Ref: f9c2119818 Node: Weak References2120986 Ref: tutorial/stdlib2 tut-weak-references2121137 Ref: f9d2121137 Ref: tutorial/stdlib2 weak-references2121137 Ref: f9e2121137 Node: Tools for Working with Lists2122893 Ref: tutorial/stdlib2 tools-for-working-with-lists2123070 Ref: fa02123070 Ref: tutorial/stdlib2 tut-list-tools2123070 Ref: fa12123070 Node: Decimal Floating Point Arithmetic2125524 Ref: tutorial/stdlib2 decimal-floating-point-arithmetic2125677 Ref: fa22125677 Ref: tutorial/stdlib2 tut-decimal-fp2125677 Ref: fa32125677 Node: Virtual Environments and Packages2127574 Ref: tutorial/venv doc2127736 Ref: fa42127736 Ref: tutorial/venv tut-venv2127736 Ref: fa52127736 Ref: tutorial/venv virtual-environments-and-packages2127736 Ref: fa62127736 Node: Introduction<4>2127923 Ref: tutorial/venv introduction2128046 Ref: fa72128046 Node: Creating Virtual Environments2129367 Ref: tutorial/venv creating-virtual-environments2129525 Ref: fa92129525 Node: Managing Packages with pip2131588 Ref: tutorial/venv managing-packages-with-pip2131722 Ref: faa2131722 Node: What Now?2136084 Ref: tutorial/whatnow doc2136250 Ref: fab2136250 Ref: tutorial/whatnow tut-whatnow2136250 Ref: fac2136250 Ref: tutorial/whatnow what-now2136250 Ref: fad2136250 Ref: What Now?-Footnote-12139714 Node: Interactive Input Editing and History Substitution2139871 Ref: tutorial/interactive doc2140052 Ref: faf2140052 Ref: tutorial/interactive interactive-input-editing-and-history-substitution2140052 Ref: fb02140052 Ref: tutorial/interactive tut-interacting2140052 Ref: e9d2140052 Ref: Interactive Input Editing and History Substitution-Footnote-12140648 Node: Tab Completion and History Editing2140709 Ref: tutorial/interactive tab-completion-and-history-editing2140882 Ref: fb12140882 Ref: tutorial/interactive tut-keybindings2140882 Ref: fb22140882 Node: Alternatives to the Interactive Interpreter2141737 Ref: tutorial/interactive alternatives-to-the-interactive-interpreter2141910 Ref: fb32141910 Ref: tutorial/interactive tut-commentary2141910 Ref: fb42141910 Ref: Alternatives to the Interactive Interpreter-Footnote-12142804 Ref: Alternatives to the Interactive Interpreter-Footnote-22142833 Node: Floating Point Arithmetic Issues and Limitations2142878 Ref: tutorial/floatingpoint doc2143058 Ref: fb52143058 Ref: tutorial/floatingpoint bpython2143058 Ref: fb62143058 Ref: tutorial/floatingpoint floating-point-arithmetic-issues-and-limitations2143058 Ref: fb72143058 Ref: tutorial/floatingpoint tut-fp-issues2143058 Ref: fb82143058 Ref: Floating Point Arithmetic Issues and Limitations-Footnote-12151146 Node: Representation Error2151185 Ref: tutorial/floatingpoint representation-error2151290 Ref: fbb2151290 Ref: tutorial/floatingpoint tut-fp-error2151290 Ref: fbc2151290 Node: Appendix2154496 Ref: tutorial/appendix doc2154617 Ref: fbd2154617 Ref: tutorial/appendix appendix2154617 Ref: fbe2154617 Ref: tutorial/appendix tut-appendix2154617 Ref: fbf2154617 Node: Interactive Mode<2>2154697 Ref: tutorial/appendix interactive-mode2154761 Ref: fc02154761 Ref: tutorial/appendix tut-interac2154761 Ref: ea32154761 Node: Error Handling2154932 Ref: tutorial/appendix error-handling2155036 Ref: fc12155036 Ref: tutorial/appendix tut-error2155036 Ref: fc22155036 Ref: Error Handling-Footnote-12156089 Node: Executable Python Scripts2156159 Ref: tutorial/appendix executable-python-scripts2156300 Ref: fc32156300 Ref: tutorial/appendix tut-scripts2156300 Ref: ea82156300 Node: The Interactive Startup File2157382 Ref: tutorial/appendix the-interactive-startup-file2157534 Ref: fc42157534 Ref: tutorial/appendix tut-startup2157534 Ref: fc52157534 Node: The Customization Modules2158970 Ref: tutorial/appendix the-customization-modules2159088 Ref: fc62159088 Ref: tutorial/appendix tut-customize2159088 Ref: fc72159088 Node: Python Setup and Usage2159991 Ref: using/index doc2160119 Ref: fc82160119 Ref: using/index python-setup-and-usage2160119 Ref: fc92160119 Ref: using/index using-index2160119 Ref: fca2160119 Node: Command line and environment2160541 Ref: using/cmdline doc2160667 Ref: fcb2160667 Ref: using/cmdline command-line-and-environment2160667 Ref: fcc2160667 Ref: using/cmdline using-on-general2160667 Ref: e9f2160667 Node: Command line2161035 Ref: using/cmdline command-line2161142 Ref: fce2161142 Ref: using/cmdline using-on-cmdline2161142 Ref: 92b2161142 Node: Interface options2161536 Ref: using/cmdline interface-options2161626 Ref: fcf2161626 Ref: using/cmdline using-on-interface-options2161626 Ref: fd02161626 Ref: using/cmdline cmdoption-c2163008 Ref: e9e2163008 Ref: using/cmdline cmdoption-m2163583 Ref: 3372163583 Ref: using/cmdline cmdarg-dash2165984 Ref: fd42165984 Ref: using/cmdline cmdarg-script2166400 Ref: fd52166400 Ref: Interface options-Footnote-12168250 Node: Generic options2168299 Ref: using/cmdline generic-options2168419 Ref: fd62168419 Ref: using/cmdline cmdoption2168468 Ref: d8c2168468 Ref: using/cmdline cmdoption-h2168491 Ref: fd72168491 Ref: using/cmdline cmdoption-help2168514 Ref: d8b2168514 Ref: using/cmdline cmdoption-v2168603 Ref: 5d22168603 Ref: using/cmdline cmdoption-version2168626 Ref: 5d12168626 Node: Miscellaneous options2168974 Ref: using/cmdline miscellaneous-options2169104 Ref: fd82169104 Ref: using/cmdline using-on-misc-options2169104 Ref: 92c2169104 Ref: using/cmdline cmdoption-b2169165 Ref: 4152169165 Ref: using/cmdline id12169504 Ref: d382169504 Ref: using/cmdline cmdoption-check-hash-based-pycs2169673 Ref: fd92169673 Ref: using/cmdline cmdoption-d2170375 Ref: fda2170375 Ref: using/cmdline cmdoption-e2170529 Ref: fdc2170529 Ref: using/cmdline cmdoption-i2170687 Ref: e1f2170687 Ref: using/cmdline id22171144 Ref: fd22171144 Ref: using/cmdline cmdoption-o2171549 Ref: 68b2171549 Ref: using/cmdline cmdoption-oo2171944 Ref: 68c2171944 Ref: using/cmdline cmdoption-q2172257 Ref: fdf2172257 Ref: using/cmdline cmdoption-r2172395 Ref: fe02172395 Ref: using/cmdline cmdoption-s2173455 Ref: d152173455 Ref: using/cmdline id32173654 Ref: b242173654 Ref: using/cmdline cmdoption-u2173978 Ref: fe32173978 Ref: using/cmdline id42174261 Ref: d882174261 Ref: using/cmdline using-on-warnings2174634 Ref: fe62174634 Ref: using/cmdline cmdoption-w2174634 Ref: 4172174634 Ref: using/cmdline cmdoption-x2176244 Ref: fe92176244 Ref: using/cmdline id52176409 Ref: 1552176409 Ref: Miscellaneous options-Footnote-12180063 Ref: Miscellaneous options-Footnote-22180112 Ref: Miscellaneous options-Footnote-32180161 Ref: Miscellaneous options-Footnote-42180210 Ref: Miscellaneous options-Footnote-52180259 Node: Options you shouldn’t use2180308 Ref: using/cmdline options-you-shouldn-t-use2180414 Ref: fed2180414 Ref: using/cmdline cmdoption-j2180485 Ref: d372180485 Ref: Options you shouldn’t use-Footnote-12180582 Node: Environment variables2180613 Ref: using/cmdline environment-variables2180720 Ref: fee2180720 Ref: using/cmdline using-on-envvars2180720 Ref: fef2180720 Ref: using/cmdline envvar-PYTHONHOME2181013 Ref: 4d62181013 Ref: using/cmdline envvar-PYTHONPATH2181619 Ref: 9532181619 Ref: using/cmdline envvar-PYTHONSTARTUP2182680 Ref: 8e52182680 Ref: using/cmdline envvar-PYTHONOPTIMIZE2183366 Ref: fde2183366 Ref: using/cmdline envvar-PYTHONBREAKPOINT2183604 Ref: 3142183604 Ref: using/cmdline envvar-PYTHONDEBUG2184227 Ref: fdb2184227 Ref: using/cmdline envvar-PYTHONINSPECT2184462 Ref: e1e2184462 Ref: using/cmdline envvar-PYTHONUNBUFFERED2184745 Ref: fe42184745 Ref: using/cmdline envvar-PYTHONVERBOSE2184895 Ref: fe52184895 Ref: using/cmdline envvar-PYTHONCASEOK2185132 Ref: e5d2185132 Ref: using/cmdline envvar-PYTHONDONTWRITEBYTECODE2185291 Ref: d392185291 Ref: using/cmdline envvar-PYTHONPYCACHEPREFIX2185535 Ref: 1542185535 Ref: using/cmdline envvar-PYTHONHASHSEED2185876 Ref: 9c52185876 Ref: using/cmdline envvar-PYTHONIOENCODING2186559 Ref: 92f2186559 Ref: using/cmdline envvar-PYTHONNOUSERSITE2187382 Ref: d162187382 Ref: using/cmdline envvar-PYTHONUSERBASE2187624 Ref: d142187624 Ref: using/cmdline envvar-PYTHONEXECUTABLE2187983 Ref: ff52187983 Ref: using/cmdline envvar-PYTHONWARNINGS2188196 Ref: 4182188196 Ref: using/cmdline envvar-PYTHONFAULTHANDLER2189117 Ref: 9c82189117 Ref: using/cmdline envvar-PYTHONTRACEMALLOC2189529 Ref: ff62189529 Ref: using/cmdline envvar-PYTHONPROFILEIMPORTTIME2190003 Ref: 3382190003 Ref: using/cmdline envvar-PYTHONASYNCIODEBUG2190280 Ref: ff72190280 Ref: using/cmdline envvar-PYTHONMALLOC2190489 Ref: 5032190489 Ref: using/cmdline envvar-PYTHONMALLOCSTATS2191747 Ref: ffa2191747 Ref: using/cmdline envvar-PYTHONLEGACYWINDOWSFSENCODING2192362 Ref: 4f72192362 Ref: using/cmdline envvar-PYTHONLEGACYWINDOWSSTDIO2192877 Ref: 4fa2192877 Ref: using/cmdline envvar-PYTHONCOERCECLOCALE2193347 Ref: 30c2193347 Ref: using/cmdline envvar-PYTHONDEVMODE2196072 Ref: 32c2196072 Ref: using/cmdline envvar-PYTHONUTF82196299 Ref: 3112196299 Ref: Environment variables-Footnote-12199092 Ref: Environment variables-Footnote-22199141 Ref: Environment variables-Footnote-32199190 Ref: Environment variables-Footnote-42199239 Ref: Environment variables-Footnote-52199288 Node: Debug-mode variables2199337 Ref: using/cmdline debug-mode-variables2199415 Ref: fff2199415 Ref: using/cmdline envvar-PYTHONTHREADDEBUG2199546 Ref: 10002199546 Ref: using/cmdline envvar-PYTHONDUMPREFS2199718 Ref: 1592199718 Node: Using Python on Unix platforms2199950 Ref: using/unix doc2200108 Ref: 10012200108 Ref: using/unix using-on-unix2200108 Ref: 10022200108 Ref: using/unix using-python-on-unix-platforms2200108 Ref: 10032200108 Node: Getting and installing the latest version of Python2200318 Ref: using/unix getting-and-installing-the-latest-version-of-python2200460 Ref: 10042200460 Node: On Linux2200646 Ref: using/unix on-linux2200773 Ref: 10052200773 Node: On FreeBSD and OpenBSD2201690 Ref: using/unix on-freebsd-and-openbsd2201840 Ref: 10062201840 Node: On OpenSolaris2202330 Ref: using/unix on-opensolaris2202463 Ref: 10072202463 Ref: On OpenSolaris-Footnote-12202683 Node: Building Python2202716 Ref: using/unix building-python2202897 Ref: 10082202897 Ref: using/unix building-python-on-unix2202897 Ref: 7f32202897 Ref: Building Python-Footnote-12203712 Ref: Building Python-Footnote-22203761 Ref: Building Python-Footnote-32203828 Node: Python-related paths and files2203890 Ref: using/unix python-related-paths-and-files2204033 Ref: 10092204033 Node: Miscellaneous2205603 Ref: using/unix miscellaneous2205722 Ref: 100a2205722 Node: Using Python on Windows2206280 Ref: using/windows doc2206437 Ref: 100b2206437 Ref: using/windows using-on-windows2206437 Ref: 2d92206437 Ref: using/windows using-python-on-windows2206437 Ref: 100c2206437 Ref: Using Python on Windows-Footnote-12208725 Ref: Using Python on Windows-Footnote-22208775 Node: The full installer2208824 Ref: using/windows the-full-installer2208938 Ref: 10102208938 Ref: using/windows windows-full2208938 Ref: 100d2208938 Node: Installation steps2209145 Ref: using/windows installation-steps2209259 Ref: 10112209259 Node: Removing the MAX_PATH Limitation2211369 Ref: using/windows max-path2211513 Ref: 4d52211513 Ref: using/windows removing-the-max-path-limitation2211513 Ref: 10132211513 Node: Installing Without UI2212373 Ref: using/windows install-quiet-option2212529 Ref: 10142212529 Ref: using/windows installing-without-ui2212529 Ref: 10152212529 Node: Installing Without Downloading2221857 Ref: using/windows install-layout-option2222001 Ref: 10122222001 Ref: using/windows installing-without-downloading2222001 Ref: 10162222001 Node: Modifying an install2222996 Ref: using/windows modifying-an-install2223110 Ref: 10172223110 Node: The Microsoft Store package2223999 Ref: using/windows the-microsoft-store-package2224144 Ref: 10182224144 Ref: using/windows windows-store2224144 Ref: e9b2224144 Node: Known Issues2226300 Ref: using/windows known-issues2226376 Ref: 10192226376 Ref: Known Issues-Footnote-12226987 Node: The nuget org packages2227083 Ref: using/windows the-nuget-org-packages2227232 Ref: 101a2227232 Ref: using/windows windows-nuget2227232 Ref: 100e2227232 Ref: The nuget org packages-Footnote-12229516 Ref: The nuget org packages-Footnote-22229547 Ref: The nuget org packages-Footnote-32229593 Node: The embeddable package2229642 Ref: using/windows the-embeddable-package2229783 Ref: 101b2229783 Ref: using/windows windows-embeddable2229783 Ref: 100f2229783 Ref: The embeddable package-Footnote-12231809 Node: Python Application2231880 Ref: using/windows python-application2231982 Ref: 101c2231982 Node: Embedding Python2233479 Ref: using/windows embedding-python2233581 Ref: 101d2233581 Node: Alternative bundles2234369 Ref: using/windows alternative-bundles2234506 Ref: 101e2234506 Ref: Alternative bundles-Footnote-12235374 Ref: Alternative bundles-Footnote-22235424 Ref: Alternative bundles-Footnote-32235467 Ref: Alternative bundles-Footnote-42235517 Node: Configuring Python2235554 Ref: using/windows configuring-python2235679 Ref: 101f2235679 Node: Excursus Setting environment variables2236247 Ref: using/windows excursus-setting-environment-variables2236378 Ref: 10202236378 Ref: using/windows setting-envvars2236378 Ref: e9c2236378 Node: Finding the Python executable2238760 Ref: using/windows finding-the-python-executable2238891 Ref: 10212238891 Ref: using/windows windows-path-mod2238891 Ref: 9902238891 Node: UTF-8 mode2240183 Ref: using/windows utf-8-mode2240316 Ref: 10222240316 Ref: using/windows win-utf8-mode2240316 Ref: 10232240316 Ref: UTF-8 mode-Footnote-12242116 Ref: UTF-8 mode-Footnote-22242165 Node: Python Launcher for Windows2242214 Ref: using/windows launcher2242344 Ref: 98f2242344 Ref: using/windows python-launcher-for-windows2242344 Ref: 10242242344 Ref: Python Launcher for Windows-Footnote-12243145 Node: Getting started2243194 Ref: using/windows getting-started2243295 Ref: 10252243295 Node: From the command-line2243450 Ref: using/windows from-the-command-line2243552 Ref: 10262243552 Node: Virtual environments2244768 Ref: using/windows virtual-environments2244892 Ref: 10272244892 Node: From a script2245388 Ref: using/windows from-a-script2245513 Ref: 10282245513 Node: From file associations2246559 Ref: using/windows from-file-associations2246655 Ref: 10292246655 Node: Shebang Lines2247232 Ref: using/windows shebang-lines2247368 Ref: 102a2247368 Node: Arguments in shebang lines2249423 Ref: using/windows arguments-in-shebang-lines2249557 Ref: 102b2249557 Node: Customization2249847 Ref: using/windows customization2249979 Ref: 102c2249979 Node: Customization via INI files2250106 Ref: using/windows customization-via-ini-files2250227 Ref: 102d2250227 Node: Customizing default Python versions2250985 Ref: using/windows customizing-default-python-versions2251106 Ref: 102e2251106 Node: Diagnostics2254965 Ref: using/windows diagnostics2255062 Ref: 102f2255062 Node: Finding modules2255495 Ref: using/windows finding-modules2255633 Ref: 4b02255633 Ref: using/windows id12255633 Ref: 10302255633 Node: Additional modules2261901 Ref: using/windows additional-modules2262039 Ref: 10322262039 Node: PyWin322262453 Ref: using/windows pywin322262533 Ref: 10342262533 Ref: PyWin32-Footnote-12263117 Ref: PyWin32-Footnote-22263158 Ref: PyWin32-Footnote-32263258 Ref: PyWin32-Footnote-42263332 Ref: PyWin32-Footnote-52263426 Ref: PyWin32-Footnote-62263484 Node: cx_Freeze2263533 Ref: using/windows cx-freeze2263628 Ref: 10352263628 Ref: cx_Freeze-Footnote-12263985 Node: WConio2264039 Ref: using/windows wconio2264118 Ref: 10372264118 Ref: WConio-Footnote-12264466 Node: Compiling Python on Windows2264526 Ref: using/windows compiling-python-on-windows2264664 Ref: 10382264664 Ref: Compiling Python on Windows-Footnote-12265632 Ref: Compiling Python on Windows-Footnote-22265681 Ref: Compiling Python on Windows-Footnote-32265748 Node: Other Platforms2265796 Ref: using/windows other-platforms2265907 Ref: 103a2265907 Ref: Other Platforms-Footnote-12266479 Ref: Other Platforms-Footnote-22266528 Ref: Other Platforms-Footnote-32266569 Ref: Other Platforms-Footnote-42266597 Ref: Other Platforms-Footnote-52266685 Ref: Other Platforms-Footnote-62266739 Node: Using Python on a Macintosh2266789 Ref: using/mac doc2266932 Ref: 103b2266932 Ref: using/mac using-on-mac2266932 Ref: 103c2266932 Ref: using/mac using-python-on-a-macintosh2266932 Ref: 103d2266932 Node: Getting and Installing MacPython2267462 Ref: using/mac getting-and-installing-macpython2267574 Ref: 103e2267574 Ref: using/mac getting-osx2267574 Ref: 103f2267574 Node: How to run a Python script2269554 Ref: using/mac how-to-run-a-python-script2269684 Ref: 10402269684 Node: Running scripts with a GUI2271155 Ref: using/mac osx-gui-scripts2271307 Ref: 10422271307 Ref: using/mac running-scripts-with-a-gui2271307 Ref: 10432271307 Node: Configuration2271723 Ref: using/mac configuration2271840 Ref: 10442271840 Node: The IDE2272383 Ref: using/mac ide2272541 Ref: 10412272541 Ref: using/mac the-ide2272541 Ref: 10462272541 Node: Installing Additional Python Packages2272755 Ref: using/mac installing-additional-python-packages2272907 Ref: 10472272907 Ref: using/mac mac-package-manager2272907 Ref: 10452272907 Node: GUI Programming on the Mac2273307 Ref: using/mac gui-programming-on-the-mac2273495 Ref: 10482273495 Node: Distributing Python Applications on the Mac2274510 Ref: using/mac distributing-python-applications-on-the-mac2274676 Ref: 10492274676 Node: Other Resources2274977 Ref: using/mac other-resources2275108 Ref: 104a2275108 Node: Editors and IDEs2275420 Ref: using/editors doc2275531 Ref: 104b2275531 Ref: using/editors editors2275531 Ref: 104c2275531 Ref: using/editors editors-and-ides2275531 Ref: 104d2275531 Ref: Editors and IDEs-Footnote-12275870 Ref: Editors and IDEs-Footnote-22275919 Ref: Editors and IDEs-Footnote-32275970 Node: The Python Language Reference2276041 Ref: reference/index doc2276177 Ref: 104e2276177 Ref: reference/index reference-index2276177 Ref: e8f2276177 Ref: reference/index the-python-language-reference2276177 Ref: 104f2276177 Node: Introduction<5>2277165 Ref: reference/introduction doc2277271 Ref: 10502277271 Ref: reference/introduction id12277271 Ref: 10512277271 Ref: reference/introduction introduction2277271 Ref: 10522277271 Node: Alternate Implementations2279066 Ref: reference/introduction alternate-implementations2279160 Ref: 10532279160 Ref: reference/introduction implementations2279160 Ref: fcd2279160 Ref: Alternate Implementations-Footnote-12281342 Ref: Alternate Implementations-Footnote-22281373 Ref: Alternate Implementations-Footnote-32281410 Ref: Alternate Implementations-Footnote-42281441 Node: Notation2281466 Ref: reference/introduction id22281560 Ref: 10542281560 Ref: reference/introduction notation2281560 Ref: 10552281560 Ref: reference/introduction grammar-token-name2281723 Ref: 10562281723 Ref: reference/introduction grammar-token-lc-letter2281771 Ref: 10572281771 Node: Lexical analysis2283805 Ref: reference/lexical_analysis doc2283930 Ref: 10582283930 Ref: reference/lexical_analysis lexical2283930 Ref: 10592283930 Ref: reference/lexical_analysis lexical-analysis2283930 Ref: 105a2283930 Ref: Lexical analysis-Footnote-12284575 Node: Line structure2284624 Ref: reference/lexical_analysis id12284712 Ref: 105b2284712 Ref: reference/lexical_analysis line-structure2284712 Ref: 105c2284712 Node: Logical lines2285018 Ref: reference/lexical_analysis id22285105 Ref: 105d2285105 Ref: reference/lexical_analysis logical-lines2285105 Ref: 105e2285105 Node: Physical lines2285483 Ref: reference/lexical_analysis id32285587 Ref: 105f2285587 Ref: reference/lexical_analysis physical-lines2285587 Ref: 10602285587 Node: Comments2286358 Ref: reference/lexical_analysis comments2286470 Ref: 10612286470 Ref: reference/lexical_analysis id42286470 Ref: 10622286470 Node: Encoding declarations2286773 Ref: reference/lexical_analysis encoding-declarations2286892 Ref: 10632286892 Ref: reference/lexical_analysis encodings2286892 Ref: 10642286892 Node: Explicit line joining2288022 Ref: reference/lexical_analysis explicit-joining2288154 Ref: 10652288154 Ref: reference/lexical_analysis explicit-line-joining2288154 Ref: 10662288154 Node: Implicit line joining2289088 Ref: reference/lexical_analysis implicit-joining2289210 Ref: 10672289210 Ref: reference/lexical_analysis implicit-line-joining2289210 Ref: 10682289210 Node: Blank lines2290046 Ref: reference/lexical_analysis blank-lines2290158 Ref: 10692290158 Ref: reference/lexical_analysis id52290158 Ref: 106a2290158 Node: Indentation2290633 Ref: reference/lexical_analysis id62290749 Ref: 106b2290749 Ref: reference/lexical_analysis indentation2290749 Ref: 106c2290749 Node: Whitespace between tokens2294135 Ref: reference/lexical_analysis whitespace2294231 Ref: 106d2294231 Ref: reference/lexical_analysis whitespace-between-tokens2294231 Ref: 106e2294231 Node: Other tokens2294633 Ref: reference/lexical_analysis id72294754 Ref: 106f2294754 Ref: reference/lexical_analysis other-tokens2294754 Ref: 10702294754 Node: Identifiers and keywords2295186 Ref: reference/lexical_analysis identifiers2295301 Ref: 10712295301 Ref: reference/lexical_analysis identifiers-and-keywords2295301 Ref: 10722295301 Ref: reference/lexical_analysis grammar-token-identifier2296196 Ref: 10732296196 Ref: reference/lexical_analysis grammar-token-id-start2296242 Ref: 10742296242 Ref: reference/lexical_analysis grammar-token-id-continue2296391 Ref: 10752296391 Ref: reference/lexical_analysis grammar-token-xid-start2296539 Ref: 10762296539 Ref: reference/lexical_analysis grammar-token-xid-continue2296646 Ref: 10772296646 Ref: Identifiers and keywords-Footnote-12297645 Ref: Identifiers and keywords-Footnote-22297694 Ref: Identifiers and keywords-Footnote-32297743 Node: Keywords2297805 Ref: reference/lexical_analysis id82297914 Ref: 10782297914 Ref: reference/lexical_analysis keywords2297914 Ref: 10792297914 Node: Reserved classes of identifiers2298509 Ref: reference/lexical_analysis id-classes2298618 Ref: 107a2298618 Ref: reference/lexical_analysis reserved-classes-of-identifiers2298618 Ref: 107b2298618 Node: Literals2300261 Ref: reference/lexical_analysis id92300373 Ref: 107d2300373 Ref: reference/lexical_analysis literals2300373 Ref: 107e2300373 Node: String and Bytes literals2300668 Ref: reference/lexical_analysis string-and-bytes-literals2300775 Ref: 107f2300775 Ref: reference/lexical_analysis strings2300775 Ref: 10802300775 Ref: reference/lexical_analysis grammar-token-stringliteral2300913 Ref: 10812300913 Ref: reference/lexical_analysis grammar-token-stringprefix2300979 Ref: 10822300979 Ref: reference/lexical_analysis grammar-token-shortstring2301119 Ref: 10832301119 Ref: reference/lexical_analysis grammar-token-longstring2301196 Ref: 10842301196 Ref: reference/lexical_analysis grammar-token-shortstringitem2301279 Ref: 10852301279 Ref: reference/lexical_analysis grammar-token-longstringitem2301338 Ref: 10862301338 Ref: reference/lexical_analysis grammar-token-shortstringchar2301396 Ref: 10872301396 Ref: reference/lexical_analysis grammar-token-longstringchar2301479 Ref: 10882301479 Ref: reference/lexical_analysis grammar-token-stringescapeseq2301538 Ref: 10892301538 Ref: reference/lexical_analysis grammar-token-bytesliteral2301591 Ref: 108a2301591 Ref: reference/lexical_analysis grammar-token-bytesprefix2301651 Ref: 108b2301651 Ref: reference/lexical_analysis grammar-token-shortbytes2301741 Ref: 108c2301741 Ref: reference/lexical_analysis grammar-token-longbytes2301815 Ref: 108d2301815 Ref: reference/lexical_analysis grammar-token-shortbytesitem2301895 Ref: 108e2301895 Ref: reference/lexical_analysis grammar-token-longbytesitem2301951 Ref: 108f2301951 Ref: reference/lexical_analysis grammar-token-shortbyteschar2302006 Ref: 10902302006 Ref: reference/lexical_analysis grammar-token-longbyteschar2302087 Ref: 10912302087 Ref: reference/lexical_analysis grammar-token-bytesescapeseq2302144 Ref: 10922302144 Ref: String and Bytes literals-Footnote-12309540 Ref: String and Bytes literals-Footnote-22309589 Node: String literal concatenation2309664 Ref: reference/lexical_analysis string-concatenation2309805 Ref: 10932309805 Ref: reference/lexical_analysis string-literal-concatenation2309805 Ref: 10942309805 Node: Formatted string literals2310848 Ref: reference/lexical_analysis f-strings2310980 Ref: 15c2310980 Ref: reference/lexical_analysis formatted-string-literals2310980 Ref: 10952310980 Ref: reference/lexical_analysis grammar-token-f-string2311591 Ref: 10962311591 Ref: reference/lexical_analysis grammar-token-replacement-field2311668 Ref: 10972311668 Ref: reference/lexical_analysis grammar-token-f-expression2311757 Ref: 10982311757 Ref: reference/lexical_analysis grammar-token-conversion2311952 Ref: 10992311952 Ref: reference/lexical_analysis grammar-token-format-spec2311995 Ref: 109a2311995 Ref: reference/lexical_analysis grammar-token-literal-char2312065 Ref: 109b2312065 Ref: Formatted string literals-Footnote-12317195 Node: Numeric literals2317244 Ref: reference/lexical_analysis numbers2317364 Ref: 109c2317364 Ref: reference/lexical_analysis numeric-literals2317364 Ref: 109d2317364 Node: Integer literals2317798 Ref: reference/lexical_analysis integer-literals2317916 Ref: 109e2317916 Ref: reference/lexical_analysis integers2317916 Ref: 109f2317916 Ref: reference/lexical_analysis grammar-token-integer2318037 Ref: 10a02318037 Ref: reference/lexical_analysis grammar-token-decinteger2318109 Ref: 10a12318109 Ref: reference/lexical_analysis grammar-token-bininteger2318179 Ref: 10a22318179 Ref: reference/lexical_analysis grammar-token-octinteger2318235 Ref: 10a32318235 Ref: reference/lexical_analysis grammar-token-hexinteger2318291 Ref: 10a42318291 Ref: reference/lexical_analysis grammar-token-nonzerodigit2318347 Ref: 10a52318347 Ref: reference/lexical_analysis grammar-token-digit2318379 Ref: 10a62318379 Ref: reference/lexical_analysis grammar-token-bindigit2318411 Ref: 10a72318411 Ref: reference/lexical_analysis grammar-token-octdigit2318443 Ref: 10a82318443 Ref: reference/lexical_analysis grammar-token-hexdigit2318475 Ref: 10a92318475 Node: Floating point literals2319329 Ref: reference/lexical_analysis floating2319449 Ref: 10aa2319449 Ref: reference/lexical_analysis floating-point-literals2319449 Ref: 10ab2319449 Ref: reference/lexical_analysis grammar-token-floatnumber2319591 Ref: 10ac2319591 Ref: reference/lexical_analysis grammar-token-pointfloat2319641 Ref: 10ad2319641 Ref: reference/lexical_analysis grammar-token-exponentfloat2319701 Ref: 10ae2319701 Ref: reference/lexical_analysis grammar-token-digitpart2319758 Ref: 10af2319758 Ref: reference/lexical_analysis grammar-token-fraction2319802 Ref: 10b02319802 Ref: reference/lexical_analysis grammar-token-exponent2319839 Ref: 10b12319839 Node: Imaginary literals2320405 Ref: reference/lexical_analysis imaginary2320500 Ref: 10b22320500 Ref: reference/lexical_analysis imaginary-literals2320500 Ref: 10b32320500 Ref: reference/lexical_analysis grammar-token-imagnumber2320627 Ref: 10b42320627 Node: Operators2321090 Ref: reference/lexical_analysis id112321188 Ref: 10b52321188 Ref: reference/lexical_analysis operators2321188 Ref: 10b62321188 Node: Delimiters2321425 Ref: reference/lexical_analysis delimiters2321506 Ref: 10b72321506 Ref: reference/lexical_analysis id122321506 Ref: 10b82321506 Node: Data model2322422 Ref: reference/datamodel doc2322547 Ref: 10b92322547 Ref: reference/datamodel data-model2322547 Ref: 10ba2322547 Ref: reference/datamodel datamodel2322547 Ref: 10bb2322547 Node: Objects values and types2322715 Ref: reference/datamodel objects2322822 Ref: 10bc2322822 Ref: reference/datamodel objects-values-and-types2322822 Ref: 10bd2322822 Ref: Objects values and types-Footnote-12327631 Node: The standard type hierarchy2327862 Ref: reference/datamodel the-standard-type-hierarchy2327998 Ref: 10bf2327998 Ref: reference/datamodel types2327998 Ref: 10c02327998 Ref: reference/datamodel frame-objects2364268 Ref: 10d32364268 Ref: reference/datamodel frame clear2366012 Ref: 80b2366012 Ref: reference/datamodel traceback-objects2366566 Ref: 3362366566 Ref: reference/datamodel slice indices2369240 Ref: 95f2369240 Node: Special method names2371010 Ref: reference/datamodel special-method-names2371132 Ref: 10d42371132 Ref: reference/datamodel specialnames2371132 Ref: 50e2371132 Ref: Special method names-Footnote-12372964 Node: Basic customization2373246 Ref: reference/datamodel basic-customization2373359 Ref: 10d52373359 Ref: reference/datamodel customization2373359 Ref: 10d62373359 Ref: reference/datamodel object __new__2373416 Ref: 8892373416 Ref: reference/datamodel object __init__2374990 Ref: d5e2374990 Ref: reference/datamodel object __del__2375849 Ref: 91f2375849 Ref: reference/datamodel object __repr__2378980 Ref: 33e2378980 Ref: reference/datamodel object __str__2379826 Ref: e372379826 Ref: reference/datamodel object __bytes__2380477 Ref: 10d82380477 Ref: reference/datamodel object __format__2380661 Ref: 94e2380661 Ref: reference/datamodel richcmpfuncs2381770 Ref: 10da2381770 Ref: reference/datamodel object __lt__2381770 Ref: c342381770 Ref: reference/datamodel object __le__2381810 Ref: ca02381810 Ref: reference/datamodel object __eq__2381850 Ref: 33f2381850 Ref: reference/datamodel object __ne__2381890 Ref: e562381890 Ref: reference/datamodel object __gt__2381930 Ref: ca12381930 Ref: reference/datamodel object __ge__2381970 Ref: ca22381970 Ref: reference/datamodel object __hash__2384490 Ref: 3402384490 Ref: reference/datamodel object __bool__2388704 Ref: c682388704 Node: Customizing attribute access2389154 Ref: reference/datamodel attribute-access2389302 Ref: 10db2389302 Ref: reference/datamodel customizing-attribute-access2389302 Ref: 10dc2389302 Ref: reference/datamodel object __getattr__2389534 Ref: 31a2389534 Ref: reference/datamodel object __getattribute__2390780 Ref: 4492390780 Ref: reference/datamodel object __setattr__2391873 Ref: e2c2391873 Ref: reference/datamodel object __delattr__2392546 Ref: 10d12392546 Ref: reference/datamodel object __dir__2392930 Ref: 31b2392930 Node: Customizing module attribute access2393258 Ref: reference/datamodel customizing-module-attribute-access2393391 Ref: 10df2393391 Ref: Customizing module attribute access-Footnote-12395517 Node: Implementing Descriptors2395566 Ref: reference/datamodel descriptors2395728 Ref: 4e92395728 Ref: reference/datamodel implementing-descriptors2395728 Ref: 10e02395728 Ref: reference/datamodel object __get__2396208 Ref: 10dd2396208 Ref: reference/datamodel object __set__2397139 Ref: 10e12397139 Ref: reference/datamodel object __delete__2397497 Ref: 10e22397497 Ref: reference/datamodel object __set_name__2397633 Ref: 4e82397633 Ref: Implementing Descriptors-Footnote-12398836 Node: Invoking Descriptors2398885 Ref: reference/datamodel descriptor-invocation2399021 Ref: 10e32399021 Ref: reference/datamodel invoking-descriptors2399021 Ref: 10e42399021 Node: __slots__2402236 Ref: reference/datamodel id32402339 Ref: 10e52402339 Ref: reference/datamodel slots2402339 Ref: 10e62402339 Ref: reference/datamodel object __slots__2402697 Ref: e2d2402697 Node: Notes on using __slots__2403050 Ref: reference/datamodel notes-on-using-slots2403120 Ref: 10e72403120 Node: Customizing class creation2405908 Ref: reference/datamodel class-customization2406077 Ref: 4e52406077 Ref: reference/datamodel customizing-class-creation2406077 Ref: 10e82406077 Ref: reference/datamodel object __init_subclass__2406544 Ref: 4e32406544 Node: Metaclasses2408082 Ref: reference/datamodel id42408186 Ref: 10e92408186 Ref: reference/datamodel metaclasses2408186 Ref: 10ea2408186 Node: Resolving MRO entries2409241 Ref: reference/datamodel resolving-mro-entries2409391 Ref: 10eb2409391 Ref: Resolving MRO entries-Footnote-12409918 Node: Determining the appropriate metaclass2409967 Ref: reference/datamodel determining-the-appropriate-metaclass2410135 Ref: 10ec2410135 Node: Preparing the class namespace2411066 Ref: reference/datamodel prepare2411237 Ref: 4fd2411237 Ref: reference/datamodel preparing-the-class-namespace2411237 Ref: 10ed2411237 Ref: Preparing the class namespace-Footnote-12412142 Node: Executing the class body2412191 Ref: reference/datamodel executing-the-class-body2412350 Ref: 10ee2412350 Node: Creating the class object2413085 Ref: reference/datamodel class-object-creation2413235 Ref: 4e42413235 Ref: reference/datamodel creating-the-class-object2413235 Ref: 10ef2413235 Ref: Creating the class object-Footnote-12415706 Node: Uses for metaclasses2415755 Ref: reference/datamodel uses-for-metaclasses2415872 Ref: 10f02415872 Node: Customizing instance and subclass checks2416183 Ref: reference/datamodel customizing-instance-and-subclass-checks2416347 Ref: 10f12416347 Ref: reference/datamodel class __instancecheck__2416837 Ref: 10f22416837 Ref: reference/datamodel class __subclasscheck__2417066 Ref: 10f32417066 Ref: Customizing instance and subclass checks-Footnote-12418019 Node: Emulating generic types2418068 Ref: reference/datamodel emulating-generic-types2418232 Ref: 10f42418232 Ref: reference/datamodel object __class_getitem__2418430 Ref: 3272418430 Ref: Emulating generic types-Footnote-12418958 Ref: Emulating generic types-Footnote-22419007 Node: Emulating callable objects2419056 Ref: reference/datamodel callable-types2419205 Ref: 10f52419205 Ref: reference/datamodel emulating-callable-objects2419205 Ref: 10f62419205 Ref: reference/datamodel object __call__2419278 Ref: 10ce2419278 Node: Emulating container types2419509 Ref: reference/datamodel emulating-container-types2419658 Ref: 10f72419658 Ref: reference/datamodel sequence-types2419658 Ref: 10f82419658 Ref: reference/datamodel object __len__2421868 Ref: dcb2421868 Ref: reference/datamodel object __length_hint__2422606 Ref: 80c2422606 Ref: reference/datamodel object __getitem__2423393 Ref: 27c2423393 Ref: reference/datamodel object __setitem__2424289 Ref: c622424289 Ref: reference/datamodel object __delitem__2424751 Ref: c632424751 Ref: reference/datamodel object __missing__2425177 Ref: b3b2425177 Ref: reference/datamodel object __iter__2425368 Ref: 50f2425368 Ref: reference/datamodel object __reversed__2425846 Ref: 52f2425846 Ref: reference/datamodel object __contains__2426830 Ref: d282426830 Node: Emulating numeric types2427394 Ref: reference/datamodel emulating-numeric-types2427548 Ref: 11012427548 Ref: reference/datamodel numeric-types2427548 Ref: 11022427548 Ref: reference/datamodel object __add__2427863 Ref: 10f92427863 Ref: reference/datamodel object __sub__2427904 Ref: 11032427904 Ref: reference/datamodel object __mul__2427945 Ref: 10fb2427945 Ref: reference/datamodel object __matmul__2427986 Ref: 6482427986 Ref: reference/datamodel object __truediv__2428030 Ref: 7862428030 Ref: reference/datamodel object __floordiv__2428075 Ref: e352428075 Ref: reference/datamodel object __mod__2428121 Ref: 11042428121 Ref: reference/datamodel object __divmod__2428162 Ref: 7872428162 Ref: reference/datamodel object __pow__2428206 Ref: 11052428206 Ref: reference/datamodel object __lshift__2428257 Ref: 11062428257 Ref: reference/datamodel object __rshift__2428301 Ref: 11072428301 Ref: reference/datamodel object __and__2428345 Ref: 11082428345 Ref: reference/datamodel object __xor__2428386 Ref: 11092428386 Ref: reference/datamodel object __or__2428427 Ref: 110a2428427 Ref: reference/datamodel object __radd__2429410 Ref: 10fa2429410 Ref: reference/datamodel object __rsub__2429452 Ref: 110b2429452 Ref: reference/datamodel object __rmul__2429494 Ref: 10fc2429494 Ref: reference/datamodel object __rmatmul__2429536 Ref: 6492429536 Ref: reference/datamodel object __rtruediv__2429581 Ref: 110c2429581 Ref: reference/datamodel object __rfloordiv__2429627 Ref: 110d2429627 Ref: reference/datamodel object __rmod__2429674 Ref: 6af2429674 Ref: reference/datamodel object __rdivmod__2429716 Ref: 110e2429716 Ref: reference/datamodel object __rpow__2429761 Ref: 110f2429761 Ref: reference/datamodel object __rlshift__2429813 Ref: 11102429813 Ref: reference/datamodel object __rrshift__2429858 Ref: 11112429858 Ref: reference/datamodel object __rand__2429903 Ref: 11122429903 Ref: reference/datamodel object __rxor__2429945 Ref: 11132429945 Ref: reference/datamodel object __ror__2429987 Ref: 11142429987 Ref: reference/datamodel object __iadd__2431240 Ref: e6f2431240 Ref: reference/datamodel object __isub__2431282 Ref: e702431282 Ref: reference/datamodel object __imul__2431324 Ref: 10fd2431324 Ref: reference/datamodel object __imatmul__2431366 Ref: 64a2431366 Ref: reference/datamodel object __itruediv__2431411 Ref: 11152431411 Ref: reference/datamodel object __ifloordiv__2431457 Ref: 11162431457 Ref: reference/datamodel object __imod__2431504 Ref: 11172431504 Ref: reference/datamodel object __ipow__2431546 Ref: 11182431546 Ref: reference/datamodel object __ilshift__2431598 Ref: 11192431598 Ref: reference/datamodel object __irshift__2431643 Ref: 111a2431643 Ref: reference/datamodel object __iand__2431688 Ref: 111b2431688 Ref: reference/datamodel object __ixor__2431730 Ref: 111c2431730 Ref: reference/datamodel object __ior__2431772 Ref: 111d2431772 Ref: reference/datamodel object __neg__2433115 Ref: 111f2433115 Ref: reference/datamodel object __pos__2433149 Ref: 11202433149 Ref: reference/datamodel object __abs__2433183 Ref: 11212433183 Ref: reference/datamodel object __invert__2433217 Ref: 11222433217 Ref: reference/datamodel object __complex__2433369 Ref: 18d2433369 Ref: reference/datamodel object __int__2433407 Ref: 18b2433407 Ref: reference/datamodel object __float__2433441 Ref: 18c2433441 Ref: reference/datamodel object __index__2433649 Ref: 18a2433649 Ref: reference/datamodel object __round__2434323 Ref: 11242434323 Ref: reference/datamodel object __trunc__2434370 Ref: 11252434370 Ref: reference/datamodel object __floor__2434406 Ref: 11262434406 Ref: reference/datamodel object __ceil__2434442 Ref: 11272434442 Ref: Emulating numeric types-Footnote-12435005 Ref: Emulating numeric types-Footnote-22435324 Node: With Statement Context Managers2435553 Ref: reference/datamodel context-managers2435703 Ref: 11282435703 Ref: reference/datamodel with-statement-context-managers2435703 Ref: 11292435703 Ref: reference/datamodel object __enter__2436466 Ref: c952436466 Ref: reference/datamodel object __exit__2436716 Ref: c962436716 Ref: With Statement Context Managers-Footnote-12437604 Node: Special method lookup2437653 Ref: reference/datamodel special-lookup2437771 Ref: 10de2437771 Ref: reference/datamodel special-method-lookup2437771 Ref: 112b2437771 Node: Coroutines2440492 Ref: reference/datamodel coroutines2440578 Ref: 112c2440578 Node: Awaitable Objects2440728 Ref: reference/datamodel awaitable-objects2440818 Ref: 112d2440818 Ref: reference/datamodel object __await__2441297 Ref: 6422441297 Ref: Awaitable Objects-Footnote-12441713 Node: Coroutine Objects2441762 Ref: reference/datamodel coroutine-objects2441883 Ref: 10cc2441883 Ref: reference/datamodel id72441883 Ref: 112f2441883 Ref: reference/datamodel coroutine send2442753 Ref: 11312442753 Ref: reference/datamodel coroutine throw2443292 Ref: 11332443292 Ref: reference/datamodel coroutine close2443888 Ref: 11352443888 Node: Asynchronous Iterators2444510 Ref: reference/datamodel async-iterators2444643 Ref: 6462444643 Ref: reference/datamodel asynchronous-iterators2444643 Ref: 11372444643 Ref: reference/datamodel object __aiter__2444867 Ref: 4872444867 Ref: reference/datamodel object __anext__2444957 Ref: 11382444957 Node: Asynchronous Context Managers2445839 Ref: reference/datamodel async-context-managers2445946 Ref: 11392445946 Ref: reference/datamodel asynchronous-context-managers2445946 Ref: 113a2445946 Ref: reference/datamodel object __aenter__2446251 Ref: 113b2446251 Ref: reference/datamodel object __aexit__2446410 Ref: 113c2446410 Node: Execution model2446885 Ref: reference/executionmodel doc2447011 Ref: 113d2447011 Ref: reference/executionmodel execmodel2447011 Ref: 113e2447011 Ref: reference/executionmodel execution-model2447011 Ref: 113f2447011 Node: Structure of a program2447141 Ref: reference/executionmodel prog-structure2447242 Ref: 11402447242 Ref: reference/executionmodel structure-of-a-program2447242 Ref: 11412447242 Node: Naming and binding2448146 Ref: reference/executionmodel naming2448269 Ref: 11422448269 Ref: reference/executionmodel naming-and-binding2448269 Ref: 11432448269 Node: Binding of names2448451 Ref: reference/executionmodel bind-names2448550 Ref: 11442448550 Ref: reference/executionmodel binding-of-names2448550 Ref: 11452448550 Node: Resolution of names2450034 Ref: reference/executionmodel resolution-of-names2450175 Ref: 11462450175 Ref: reference/executionmodel resolve-names2450175 Ref: 11472450175 Node: Builtins and restricted execution2453565 Ref: reference/executionmodel builtins-and-restricted-execution2453723 Ref: 11482453723 Ref: reference/executionmodel restrict-exec2453723 Ref: 11492453723 Node: Interaction with dynamic features2454568 Ref: reference/executionmodel dynamic-features2454698 Ref: 114a2454698 Ref: reference/executionmodel interaction-with-dynamic-features2454698 Ref: 114b2454698 Ref: Interaction with dynamic features-Footnote-12455490 Node: Exceptions<2>2455632 Ref: reference/executionmodel exceptions2455724 Ref: 114c2455724 Ref: reference/executionmodel id22455724 Ref: 114d2455724 Node: The import system2457882 Ref: reference/import doc2458009 Ref: 114e2458009 Ref: reference/import importsystem2458009 Ref: 10cf2458009 Ref: reference/import the-import-system2458009 Ref: 114f2458009 Ref: The import system-Footnote-12460659 Ref: The import system-Footnote-22460704 Ref: The import system-Footnote-32460753 Node: importlib<7>2460802 Ref: reference/import importlib2460888 Ref: 11532460888 Node: Packages<2>2461263 Ref: reference/import packages2461367 Ref: 11542461367 Node: Regular packages2462804 Ref: reference/import regular-packages2462895 Ref: 11562462895 Node: Namespace packages2464107 Ref: reference/import namespace-packages2464198 Ref: 11592464198 Ref: Namespace packages-Footnote-12465575 Node: Searching2465624 Ref: reference/import searching2465723 Ref: 115b2465723 Node: The module cache2466548 Ref: reference/import the-module-cache2466638 Ref: 115c2466638 Node: Finders and loaders2468202 Ref: reference/import finders-and-loaders2468313 Ref: 115d2468313 Ref: reference/import id22468313 Ref: 115e2468313 Node: Import hooks2470070 Ref: reference/import import-hooks2470178 Ref: 11632470178 Node: The meta path2471050 Ref: reference/import the-meta-path2471130 Ref: 11642471130 Node: Loading2474129 Ref: reference/import loading2474238 Ref: 11662474238 Ref: Loading-Footnote-12477544 Node: Loaders2477928 Ref: reference/import loaders2477998 Ref: 11682477998 Node: Submodules2481255 Ref: reference/import submodules2481345 Ref: 11692481345 Node: Module spec2482649 Ref: reference/import module-spec2482764 Ref: 116a2482764 Node: Import-related module attributes2483603 Ref: reference/import import-mod-attrs2483723 Ref: 11672483723 Ref: reference/import import-related-module-attributes2483723 Ref: 116c2483723 Ref: reference/import __name__2483961 Ref: d122483961 Ref: reference/import __loader__2484159 Ref: 9562484159 Ref: reference/import __package__2484475 Ref: 9552484475 Ref: reference/import __spec__2485302 Ref: 116d2485302 Ref: reference/import __path__2485911 Ref: f232485911 Ref: reference/import __file__2486403 Ref: 10d02486403 Ref: reference/import __cached__2486428 Ref: b322486428 Ref: Import-related module attributes-Footnote-12487417 Ref: Import-related module attributes-Footnote-22487466 Ref: Import-related module attributes-Footnote-32487515 Node: module __path__2487564 Ref: reference/import module-path2487685 Ref: 11712487685 Ref: reference/import package-path-rules2487685 Ref: 11702487685 Ref: module __path__-Footnote-12488867 Ref: module __path__-Footnote-22488916 Node: Module reprs2488965 Ref: reference/import module-reprs2489082 Ref: 11722489082 Node: Cached bytecode invalidation2490753 Ref: reference/import cached-bytecode-invalidation2490846 Ref: 11732490846 Ref: reference/import pyc-invalidation2490846 Ref: 3292490846 Node: The Path Based Finder2492196 Ref: reference/import the-path-based-finder2492332 Ref: 11742492332 Node: Path entry finders2494836 Ref: reference/import path-entry-finders2494947 Ref: 11762494947 Ref: Path entry finders-Footnote-12500008 Node: Path entry finder protocol2500266 Ref: reference/import path-entry-finder-protocol2500377 Ref: 11782500377 Node: Replacing the standard import system2502545 Ref: reference/import replacing-the-standard-import-system2502698 Ref: 11792502698 Node: Package Relative Imports2503701 Ref: reference/import package-relative-imports2503868 Ref: 117a2503868 Ref: reference/import relativeimports2503868 Ref: 117b2503868 Node: Special considerations for __main__2505071 Ref: reference/import special-considerations-for-main2505213 Ref: 117c2505213 Node: __main__ __spec__2505816 Ref: reference/import id52505905 Ref: 117d2505905 Ref: reference/import main-spec2505905 Ref: 116f2505905 Node: Open issues2507301 Ref: reference/import open-issues2507429 Ref: 117e2507429 Ref: Open issues-Footnote-12508065 Node: References2508114 Ref: reference/import references2508198 Ref: 117f2508198 Ref: References-Footnote-12509431 Ref: References-Footnote-22509483 Ref: References-Footnote-32509532 Ref: References-Footnote-42509581 Ref: References-Footnote-52509630 Ref: References-Footnote-62509679 Ref: References-Footnote-72509728 Ref: References-Footnote-82509777 Ref: References-Footnote-92509826 Ref: References-Footnote-102509875 Node: Expressions2509925 Ref: reference/expressions doc2510054 Ref: 11802510054 Ref: reference/expressions expressions2510054 Ref: 11812510054 Ref: reference/expressions id12510054 Ref: 11822510054 Ref: reference/expressions grammar-token-name2510348 Ref: 11832510348 Node: Arithmetic conversions2510914 Ref: reference/expressions arithmetic-conversions2510998 Ref: 11842510998 Ref: reference/expressions conversions2510998 Ref: 11852510998 Node: Atoms2511701 Ref: reference/expressions atoms2511803 Ref: 11862511803 Ref: reference/expressions id22511803 Ref: 11872511803 Ref: reference/expressions grammar-token-atom2512050 Ref: 11882512050 Ref: reference/expressions grammar-token-enclosure2512102 Ref: 11892512102 Node: Identifiers Names2512529 Ref: reference/expressions atom-identifiers2512608 Ref: 107c2512608 Ref: reference/expressions identifiers-names2512608 Ref: 118a2512608 Node: Literals<2>2513902 Ref: reference/expressions atom-literals2514009 Ref: 118b2514009 Ref: reference/expressions literals2514009 Ref: 118c2514009 Ref: reference/expressions grammar-token-literal2514117 Ref: 118d2514117 Node: Parenthesized forms2514824 Ref: reference/expressions parenthesized2514954 Ref: 118e2514954 Ref: reference/expressions parenthesized-forms2514954 Ref: 118f2514954 Ref: reference/expressions grammar-token-parenth-form2515089 Ref: 11902515089 Node: Displays for lists sets and dictionaries2515853 Ref: reference/expressions comprehensions2515985 Ref: 11912515985 Ref: reference/expressions displays-for-lists-sets-and-dictionaries2515985 Ref: 11922515985 Ref: reference/expressions grammar-token-comprehension2516431 Ref: 11932516431 Ref: reference/expressions grammar-token-comp-for2516485 Ref: 11942516485 Ref: reference/expressions grammar-token-comp-iter2516561 Ref: 11952516561 Ref: reference/expressions grammar-token-comp-if2516603 Ref: 11962516603 Ref: Displays for lists sets and dictionaries-Footnote-12518794 Node: List displays2518843 Ref: reference/expressions list-displays2518968 Ref: 11972518968 Ref: reference/expressions lists2518968 Ref: 11982518968 Ref: reference/expressions grammar-token-list-display2519100 Ref: 11992519100 Node: Set displays2519546 Ref: reference/expressions set2519650 Ref: 119a2519650 Ref: reference/expressions set-displays2519650 Ref: 119b2519650 Ref: reference/expressions grammar-token-set-display2519830 Ref: 119c2519830 Node: Dictionary displays2520362 Ref: reference/expressions dict2520474 Ref: 64e2520474 Ref: reference/expressions dictionary-displays2520474 Ref: 119d2520474 Ref: reference/expressions grammar-token-dict-display2520625 Ref: 119e2520625 Ref: reference/expressions grammar-token-key-datum-list2520699 Ref: 119f2520699 Ref: reference/expressions grammar-token-key-datum2520760 Ref: 11a02520760 Ref: reference/expressions grammar-token-dict-comprehension2520829 Ref: 11a12520829 Ref: Dictionary displays-Footnote-12522644 Ref: Dictionary displays-Footnote-22522693 Node: Generator expressions2522742 Ref: reference/expressions generator-expressions2522859 Ref: 11a22522859 Ref: reference/expressions genexpr2522859 Ref: 11a32522859 Ref: reference/expressions grammar-token-generator-expression2522992 Ref: 11a42522992 Node: Yield expressions2524934 Ref: reference/expressions yield-expressions2525023 Ref: 11a52525023 Ref: reference/expressions yieldexpr2525023 Ref: 11a62525023 Ref: reference/expressions grammar-token-yield-atom2525076 Ref: 11a72525076 Ref: reference/expressions grammar-token-yield-expression2525127 Ref: 11a82525127 Ref: Yield expressions-Footnote-12530011 Ref: Yield expressions-Footnote-22530060 Ref: Yield expressions-Footnote-32530109 Ref: Yield expressions-Footnote-42530158 Ref: Yield expressions-Footnote-52530207 Node: Generator-iterator methods2530256 Ref: reference/expressions generator-iterator-methods2530353 Ref: 11ac2530353 Ref: reference/expressions generator-methods2530353 Ref: 11302530353 Ref: reference/expressions generator __next__2530695 Ref: f6f2530695 Ref: reference/expressions generator send2531456 Ref: 11322531456 Ref: reference/expressions generator throw2532038 Ref: 11342532038 Ref: reference/expressions generator close2532524 Ref: 11362532524 Node: Examples2533109 Ref: reference/expressions examples2533247 Ref: 11ad2533247 Node: Asynchronous generator functions2534306 Ref: reference/expressions asynchronous-generator-functions2534457 Ref: 11aa2534457 Ref: reference/expressions id32534457 Ref: 11ae2534457 Ref: Asynchronous generator functions-Footnote-12537526 Node: Asynchronous generator-iterator methods2537605 Ref: reference/expressions asynchronous-generator-iterator-methods2537739 Ref: 11b32537739 Ref: reference/expressions asynchronous-generator-methods2537739 Ref: 11b42537739 Ref: reference/expressions agen __anext__2537981 Ref: 11af2537981 Ref: reference/expressions agen asend2538912 Ref: 11b02538912 Ref: reference/expressions agen athrow2539777 Ref: 11b52539777 Ref: reference/expressions agen aclose2540465 Ref: 11b12540465 Node: Primaries2541480 Ref: reference/expressions id42541576 Ref: 11b62541576 Ref: reference/expressions primaries2541576 Ref: 11b72541576 Ref: reference/expressions grammar-token-primary2541698 Ref: 11b82541698 Node: Attribute references2541844 Ref: reference/expressions attribute-references2541932 Ref: 11b92541932 Ref: reference/expressions id52541932 Ref: 11ba2541932 Ref: reference/expressions grammar-token-attributeref2542061 Ref: 11bb2542061 Node: Subscriptions2542640 Ref: reference/expressions id62542745 Ref: 11bc2542745 Ref: reference/expressions subscriptions2542745 Ref: 11bd2542745 Ref: reference/expressions grammar-token-subscription2542892 Ref: 11be2542892 Node: Slicings2544417 Ref: reference/expressions id72544507 Ref: 11bf2544507 Ref: reference/expressions slicings2544507 Ref: 11c02544507 Ref: reference/expressions grammar-token-slicing2544755 Ref: 11c12544755 Ref: reference/expressions grammar-token-slice-list2544804 Ref: 11c22544804 Ref: reference/expressions grammar-token-slice-item2544861 Ref: 11c32544861 Ref: reference/expressions grammar-token-proper-slice2544909 Ref: 11c42544909 Ref: reference/expressions grammar-token-lower-bound2544980 Ref: 11c52544980 Ref: reference/expressions grammar-token-upper-bound2545013 Ref: 11c62545013 Ref: reference/expressions grammar-token-stride2545046 Ref: 11c72545046 Node: Calls2546264 Ref: reference/expressions calls2546332 Ref: 64c2546332 Ref: reference/expressions id82546332 Ref: 11c82546332 Ref: reference/expressions grammar-token-call2546481 Ref: 11cb2546481 Ref: reference/expressions grammar-token-argument-list2546565 Ref: 11cc2546565 Ref: reference/expressions grammar-token-positional-arguments2546829 Ref: 11cd2546829 Ref: reference/expressions grammar-token-positional-item2546898 Ref: 11ce2546898 Ref: reference/expressions grammar-token-starred-and-keywords2546967 Ref: 11cf2546967 Ref: reference/expressions grammar-token-keywords-arguments2547100 Ref: 11d02547100 Ref: reference/expressions grammar-token-keyword-item2547235 Ref: 11d12547235 Ref: Calls-Footnote-12553271 Node: Await expression2553320 Ref: reference/expressions await2553429 Ref: 1a32553429 Ref: reference/expressions await-expression2553429 Ref: 11d32553429 Ref: reference/expressions grammar-token-await-expr2553618 Ref: 11d42553618 Node: The power operator2553676 Ref: reference/expressions power2553815 Ref: 11d52553815 Ref: reference/expressions the-power-operator2553815 Ref: 11d62553815 Ref: reference/expressions grammar-token-power2554012 Ref: 11d72554012 Node: Unary arithmetic and bitwise operations2555061 Ref: reference/expressions unary2555212 Ref: 11d82555212 Ref: reference/expressions unary-arithmetic-and-bitwise-operations2555212 Ref: 11d92555212 Ref: reference/expressions grammar-token-u-expr2555374 Ref: 11da2555374 Node: Binary arithmetic operations2555894 Ref: reference/expressions binary2556046 Ref: 11db2556046 Ref: reference/expressions binary-arithmetic-operations2556046 Ref: 11dc2556046 Ref: reference/expressions grammar-token-m-expr2556390 Ref: 11dd2556390 Ref: reference/expressions grammar-token-a-expr2556546 Ref: 11de2556546 Ref: Binary arithmetic operations-Footnote-12559399 Ref: Binary arithmetic operations-Footnote-22560016 Node: Shifting operations2560303 Ref: reference/expressions shifting2560441 Ref: 11e02560441 Ref: reference/expressions shifting-operations2560441 Ref: 11e12560441 Ref: reference/expressions grammar-token-shift-expr2560571 Ref: 11e22560571 Node: Binary bitwise operations2560935 Ref: reference/expressions binary-bitwise-operations2561056 Ref: 11e32561056 Ref: reference/expressions bitwise2561056 Ref: 11e42561056 Ref: reference/expressions grammar-token-and-expr2561191 Ref: 11e52561191 Ref: reference/expressions grammar-token-xor-expr2561246 Ref: 11e62561246 Ref: reference/expressions grammar-token-or-expr2561297 Ref: 11e72561297 Node: Comparisons2561635 Ref: reference/expressions comparisons2561755 Ref: 11e82561755 Ref: reference/expressions id112561755 Ref: 11e92561755 Ref: reference/expressions grammar-token-comparison2562050 Ref: 11ea2562050 Ref: reference/expressions grammar-token-comp-operator2562106 Ref: 11eb2562106 Node: Value comparisons2563046 Ref: reference/expressions value-comparisons2563146 Ref: 11ec2563146 Ref: reference/expressions in2570994 Ref: 7a32570994 Ref: reference/expressions not-in2570994 Ref: 10ff2570994 Ref: Value comparisons-Footnote-12571032 Ref: Value comparisons-Footnote-22571081 Node: Membership test operations2572197 Ref: reference/expressions membership-test-details2572326 Ref: 11002572326 Ref: reference/expressions membership-test-operations2572326 Ref: 11ee2572326 Ref: reference/expressions is2574220 Ref: 10be2574220 Node: Identity comparisons2574220 Ref: reference/expressions identity-comparisons2574323 Ref: 11ef2574323 Ref: reference/expressions is-not2574323 Ref: 11f02574323 Ref: reference/expressions booleans2574669 Ref: 11f12574669 Ref: reference/expressions and2574669 Ref: 11f22574669 Ref: reference/expressions or2574669 Ref: 11f32574669 Ref: Identity comparisons-Footnote-12574707 Node: Boolean operations2575014 Ref: reference/expressions boolean-operations2575134 Ref: 11f42575134 Ref: reference/expressions not2575134 Ref: 11f52575134 Ref: reference/expressions grammar-token-or-test2575187 Ref: 11f62575187 Ref: reference/expressions grammar-token-and-test2575238 Ref: 11f72575238 Ref: reference/expressions grammar-token-not-test2575291 Ref: 11f82575291 Node: Assignment expressions<2>2576734 Ref: reference/expressions assignment-expressions2576866 Ref: 11f92576866 Ref: reference/expressions grammar-token-assignment-expression2576927 Ref: 11fa2576927 Ref: Assignment expressions<2>-Footnote-12577575 Node: Conditional expressions2577624 Ref: reference/expressions conditional-expressions2577745 Ref: 11fc2577745 Ref: reference/expressions if-expr2577745 Ref: 11fd2577745 Ref: reference/expressions grammar-token-conditional-expression2577808 Ref: 11fe2577808 Ref: reference/expressions grammar-token-expression2577881 Ref: 11fb2577881 Ref: reference/expressions grammar-token-expression-nocond2577950 Ref: 11ff2577950 Ref: reference/expressions lambdas2578398 Ref: 12002578398 Ref: Conditional expressions-Footnote-12578436 Node: Lambdas2578485 Ref: reference/expressions id142578597 Ref: 12012578597 Ref: reference/expressions lambda2578597 Ref: c2f2578597 Ref: reference/expressions grammar-token-lambda-expr2578628 Ref: 12022578628 Ref: reference/expressions grammar-token-lambda-expr-nocond2578697 Ref: 12032578697 Node: Expression lists2579244 Ref: reference/expressions expression-lists2579349 Ref: 12042579349 Ref: reference/expressions exprlists2579349 Ref: 64d2579349 Ref: reference/expressions grammar-token-expression-list2579398 Ref: 11ab2579398 Ref: reference/expressions grammar-token-starred-list2579461 Ref: 12052579461 Ref: reference/expressions grammar-token-starred-expression2579528 Ref: 12062579528 Ref: reference/expressions grammar-token-starred-item2579604 Ref: 12072579604 Ref: Expression lists-Footnote-12580572 Node: Evaluation order2580621 Ref: reference/expressions evalorder2580738 Ref: 12082580738 Ref: reference/expressions evaluation-order2580738 Ref: 12092580738 Node: Operator precedence2581253 Ref: reference/expressions operator-precedence2581345 Ref: 120a2581345 Ref: reference/expressions operator-summary2581345 Ref: 120b2581345 Ref: Operator precedence-Footnote-12585896 Ref: Operator precedence-Footnote-22585994 Node: Simple statements2586147 Ref: reference/simple_stmts doc2586278 Ref: 120c2586278 Ref: reference/simple_stmts simple2586278 Ref: 120d2586278 Ref: reference/simple_stmts simple-statements2586278 Ref: 120e2586278 Ref: reference/simple_stmts grammar-token-simple-stmt2586502 Ref: 120f2586502 Node: Expression statements2587447 Ref: reference/simple_stmts expression-statements2587552 Ref: 12102587552 Ref: reference/simple_stmts exprstmts2587552 Ref: 12112587552 Ref: reference/simple_stmts grammar-token-expression-stmt2587942 Ref: 12122587942 Node: Assignment statements2588369 Ref: reference/simple_stmts assignment2588503 Ref: 12132588503 Ref: reference/simple_stmts assignment-statements2588503 Ref: 12142588503 Ref: reference/simple_stmts grammar-token-assignment-stmt2588674 Ref: 12152588674 Ref: reference/simple_stmts grammar-token-target-list2588758 Ref: 12162588758 Ref: reference/simple_stmts grammar-token-target2588810 Ref: 12172588810 Ref: reference/simple_stmts attr-target-note2592450 Ref: 12182592450 Ref: Assignment statements-Footnote-12596507 Node: Augmented assignment statements2596556 Ref: reference/simple_stmts augassign2596685 Ref: 12192596685 Ref: reference/simple_stmts augmented-assignment-statements2596685 Ref: 121a2596685 Ref: reference/simple_stmts grammar-token-augmented-assignment-stmt2596882 Ref: 121b2596882 Ref: reference/simple_stmts grammar-token-augtarget2596970 Ref: 121c2596970 Ref: reference/simple_stmts grammar-token-augop2597056 Ref: 121d2597056 Node: Annotated assignment statements2598798 Ref: reference/simple_stmts annassign2598927 Ref: 121e2598927 Ref: reference/simple_stmts annotated-assignment-statements2598927 Ref: 121f2598927 Ref: reference/simple_stmts grammar-token-annotated-assignment-stmt2599162 Ref: 12202599162 Ref: Annotated assignment statements-Footnote-12601109 Ref: Annotated assignment statements-Footnote-22601158 Node: The assert statement2601207 Ref: reference/simple_stmts assert2601338 Ref: e062601338 Ref: reference/simple_stmts the-assert-statement2601338 Ref: 12212601338 Ref: reference/simple_stmts grammar-token-assert-stmt2601488 Ref: 12222601488 Node: The pass statement2602572 Ref: reference/simple_stmts pass2602702 Ref: ed42602702 Ref: reference/simple_stmts the-pass-statement2602702 Ref: 12242602702 Ref: reference/simple_stmts grammar-token-pass-stmt2602761 Ref: 12252602761 Node: The del statement<2>2603111 Ref: reference/simple_stmts del2603241 Ref: f022603241 Ref: reference/simple_stmts the-del-statement2603241 Ref: 12262603241 Ref: reference/simple_stmts grammar-token-del-stmt2603298 Ref: 12272603298 Node: The return statement2604218 Ref: reference/simple_stmts return2604349 Ref: 1902604349 Ref: reference/simple_stmts the-return-statement2604349 Ref: 12282604349 Ref: reference/simple_stmts grammar-token-return-stmt2604412 Ref: 12292604412 Node: The yield statement2605537 Ref: reference/simple_stmts the-yield-statement2605667 Ref: 122a2605667 Ref: reference/simple_stmts yield2605667 Ref: 18f2605667 Ref: reference/simple_stmts grammar-token-yield-stmt2605728 Ref: 122b2605728 Node: The raise statement2606563 Ref: reference/simple_stmts raise2606692 Ref: c422606692 Ref: reference/simple_stmts the-raise-statement2606692 Ref: 122c2606692 Ref: reference/simple_stmts grammar-token-raise-stmt2606753 Ref: 122d2606753 Node: The break statement2610087 Ref: reference/simple_stmts break2610219 Ref: 2db2610219 Ref: reference/simple_stmts the-break-statement2610219 Ref: 122e2610219 Ref: reference/simple_stmts grammar-token-break-stmt2610280 Ref: 122f2610280 Node: The continue statement2610873 Ref: reference/simple_stmts continue2611006 Ref: 1812611006 Ref: reference/simple_stmts the-continue-statement2611006 Ref: 12302611006 Ref: reference/simple_stmts grammar-token-continue-stmt2611075 Ref: 12312611075 Ref: reference/simple_stmts import2611540 Ref: c1d2611540 Node: The import statement2611542 Ref: reference/simple_stmts from2611676 Ref: c452611676 Ref: reference/simple_stmts the-import-statement2611676 Ref: 12322611676 Ref: reference/simple_stmts grammar-token-import-stmt2611741 Ref: 12332611741 Ref: reference/simple_stmts grammar-token-module2612198 Ref: 12342612198 Ref: reference/simple_stmts grammar-token-relative-module2612252 Ref: 12352612252 Node: Future statements2617501 Ref: reference/simple_stmts future2617575 Ref: 12362617575 Ref: reference/simple_stmts future-statements2617575 Ref: 12372617575 Ref: reference/simple_stmts grammar-token-future-stmt2618101 Ref: 12382618101 Ref: reference/simple_stmts grammar-token-feature2618377 Ref: 12392618377 Ref: Future statements-Footnote-12621094 Ref: Future statements-Footnote-22621143 Node: The global statement2621192 Ref: reference/simple_stmts global2621326 Ref: ed82621326 Ref: reference/simple_stmts the-global-statement2621326 Ref: 123a2621326 Ref: reference/simple_stmts grammar-token-global-stmt2621391 Ref: 123b2621391 Node: The nonlocal statement2622936 Ref: reference/simple_stmts nonlocal2623041 Ref: c3f2623041 Ref: reference/simple_stmts the-nonlocal-statement2623041 Ref: 123c2623041 Ref: reference/simple_stmts grammar-token-nonlocal-stmt2623110 Ref: 123d2623110 Ref: The nonlocal statement-Footnote-12624084 Node: Compound statements2624133 Ref: reference/compound_stmts doc2624273 Ref: 123e2624273 Ref: reference/compound_stmts compound2624273 Ref: 123f2624273 Ref: reference/compound_stmts compound-statements2624273 Ref: 12402624273 Ref: reference/compound_stmts grammar-token-compound-stmt2626041 Ref: 12412626041 Ref: reference/compound_stmts grammar-token-suite2626398 Ref: 12422626398 Ref: reference/compound_stmts grammar-token-statement2626474 Ref: 12432626474 Ref: reference/compound_stmts grammar-token-stmt-list2626531 Ref: 12442626531 Ref: reference/compound_stmts if2627056 Ref: de72627056 Ref: reference/compound_stmts elif2627056 Ref: ec72627056 Node: The if statement2627255 Ref: reference/compound_stmts else2627355 Ref: ec82627355 Ref: reference/compound_stmts the-if-statement2627355 Ref: 12452627355 Ref: reference/compound_stmts grammar-token-if-stmt2627475 Ref: 12462627475 Node: The while statement2628022 Ref: reference/compound_stmts the-while-statement2628148 Ref: 12472628148 Ref: reference/compound_stmts while2628148 Ref: ec12628148 Ref: reference/compound_stmts grammar-token-while-stmt2628307 Ref: 12482628307 Node: The for statement2628907 Ref: reference/compound_stmts for2629034 Ref: c302629034 Ref: reference/compound_stmts the-for-statement2629034 Ref: 12492629034 Ref: reference/compound_stmts grammar-token-for-stmt2629233 Ref: 124a2629233 Ref: reference/compound_stmts try2631993 Ref: d722631993 Ref: reference/compound_stmts except2631993 Ref: b3e2631993 Node: The try statement2631994 Ref: reference/compound_stmts finally2632120 Ref: 1822632120 Ref: reference/compound_stmts the-try-statement2632120 Ref: 124b2632120 Ref: reference/compound_stmts grammar-token-try-stmt2632284 Ref: 124c2632284 Ref: reference/compound_stmts grammar-token-try1-stmt2632325 Ref: 124d2632325 Ref: reference/compound_stmts grammar-token-try2-stmt2632511 Ref: 124e2632511 Ref: reference/compound_stmts with2637785 Ref: 6e92637785 Ref: The try statement-Footnote-12637821 Node: The with statement2638023 Ref: reference/compound_stmts as2638152 Ref: 124f2638152 Ref: reference/compound_stmts the-with-statement2638152 Ref: 12502638152 Ref: reference/compound_stmts grammar-token-with-stmt2638521 Ref: 12512638521 Ref: reference/compound_stmts grammar-token-with-item2638584 Ref: 12522638584 Ref: reference/compound_stmts function2641439 Ref: ef02641439 Ref: The with statement-Footnote-12641475 Node: Function definitions2641524 Ref: reference/compound_stmts def2641653 Ref: dbe2641653 Ref: reference/compound_stmts function-definitions2641653 Ref: 12532641653 Ref: reference/compound_stmts grammar-token-funcdef2641826 Ref: 12542641826 Ref: reference/compound_stmts grammar-token-decorators2641977 Ref: 12552641977 Ref: reference/compound_stmts grammar-token-decorator2642023 Ref: 12562642023 Ref: reference/compound_stmts grammar-token-dotted-name2642114 Ref: 12572642114 Ref: reference/compound_stmts grammar-token-parameter-list2642178 Ref: 12582642178 Ref: reference/compound_stmts grammar-token-parameter-list-no-posonly2642353 Ref: 12592642353 Ref: reference/compound_stmts grammar-token-parameter-list-starargs2642514 Ref: 125a2642514 Ref: reference/compound_stmts grammar-token-parameter2642672 Ref: 125b2642672 Ref: reference/compound_stmts grammar-token-defparameter2642735 Ref: 125c2642735 Ref: reference/compound_stmts grammar-token-funcname2642797 Ref: 125d2642797 Ref: Function definitions-Footnote-12648489 Ref: Function definitions-Footnote-22648687 Ref: Function definitions-Footnote-32648736 Ref: Function definitions-Footnote-42648785 Ref: Function definitions-Footnote-52648834 Node: Class definitions2648883 Ref: reference/compound_stmts class2649007 Ref: c6a2649007 Ref: reference/compound_stmts class-definitions2649007 Ref: 125f2649007 Ref: reference/compound_stmts grammar-token-classdef2649155 Ref: 12602649155 Ref: reference/compound_stmts grammar-token-inheritance2649231 Ref: 12612649231 Ref: reference/compound_stmts grammar-token-classname2649276 Ref: 12622649276 Ref: Class definitions-Footnote-12651993 Ref: Class definitions-Footnote-22652181 Ref: Class definitions-Footnote-32652230 Ref: Class definitions-Footnote-42652279 Node: Coroutines<2>2652328 Ref: reference/compound_stmts async2652423 Ref: 1a22652423 Ref: reference/compound_stmts coroutines2652423 Ref: 12632652423 Node: Coroutine function definition2652580 Ref: reference/compound_stmts async-def2652691 Ref: 2842652691 Ref: reference/compound_stmts coroutine-function-definition2652691 Ref: 12642652691 Ref: reference/compound_stmts grammar-token-async-funcdef2652768 Ref: 12652652768 Node: The async for statement2653626 Ref: reference/compound_stmts async-for2653770 Ref: 2e32653770 Ref: reference/compound_stmts the-async-for-statement2653770 Ref: 12662653770 Ref: reference/compound_stmts grammar-token-async-for-stmt2653843 Ref: 12672653843 Node: The async with statement2654771 Ref: reference/compound_stmts async-with2654877 Ref: 6432654877 Ref: reference/compound_stmts the-async-with-statement2654877 Ref: 12682654877 Ref: reference/compound_stmts grammar-token-async-with-stmt2654952 Ref: 12692654952 Ref: The async with statement-Footnote-12656083 Node: Top-level components2656132 Ref: reference/toplevel_components doc2656281 Ref: 126a2656281 Ref: reference/toplevel_components top-level2656281 Ref: 126b2656281 Ref: reference/toplevel_components top-level-components2656281 Ref: 126c2656281 Node: Complete Python programs2656674 Ref: reference/toplevel_components complete-python-programs2656774 Ref: 126d2656774 Ref: reference/toplevel_components programs2656774 Ref: 116e2656774 Node: File input2658156 Ref: reference/toplevel_components file-input2658282 Ref: 126e2658282 Ref: reference/toplevel_components id12658282 Ref: 126f2658282 Ref: reference/toplevel_components grammar-token-file-input2658379 Ref: 12702658379 Node: Interactive input2658655 Ref: reference/toplevel_components interactive2658773 Ref: 12712658773 Ref: reference/toplevel_components interactive-input2658773 Ref: 12722658773 Ref: reference/toplevel_components grammar-token-interactive-input2658888 Ref: 12732658888 Node: Expression input2659121 Ref: reference/toplevel_components expression-input2659220 Ref: 12742659220 Ref: reference/toplevel_components id22659220 Ref: 12752659220 Ref: reference/toplevel_components grammar-token-eval-input2659422 Ref: 12762659422 Node: Full Grammar specification2659468 Ref: reference/grammar doc2659589 Ref: 12772659589 Ref: reference/grammar full-grammar-specification2659589 Ref: 12782659589 Node: The Python Standard Library2670581 Ref: library/index doc2670741 Ref: 12792670741 Ref: library/index library-index2670741 Ref: e8e2670741 Ref: library/index the-python-standard-library2670741 Ref: 127a2670741 Ref: The Python Standard Library-Footnote-12673432 Node: Introduction<6>2673457 Ref: library/intro doc2673563 Ref: 127b2673563 Ref: library/intro introduction2673563 Ref: 127c2673563 Ref: library/intro library-intro2673563 Ref: 127d2673563 Node: Notes on availability2676246 Ref: library/intro availability2676319 Ref: ffb2676319 Ref: library/intro notes-on-availability2676319 Ref: 127e2676319 Node: Built-in Functions2676708 Ref: library/functions doc2676841 Ref: 127f2676841 Ref: library/functions built-in-funcs2676841 Ref: bf32676841 Ref: library/functions built-in-functions2676841 Ref: 12802676841 Ref: library/functions abs2681402 Ref: f542681402 Ref: library/functions all2681689 Ref: d852681689 Ref: library/functions any2682002 Ref: d842682002 Ref: library/functions ascii2682326 Ref: d4c2682326 Ref: library/functions bin2682684 Ref: c402682684 Ref: library/functions bool2683352 Ref: 1832683352 Ref: library/functions breakpoint2683943 Ref: 2f92683943 Ref: library/functions func-bytearray2684773 Ref: 12872684773 Ref: library/functions func-bytes2686160 Ref: 10d92686160 Ref: library/functions callable2686859 Ref: b442686859 Ref: library/functions chr2687412 Ref: 10c72687412 Ref: library/functions classmethod2687868 Ref: 1d82687868 Ref: library/functions compile2688860 Ref: 1b42688860 Ref: library/functions complex2693079 Ref: 1892693079 Ref: library/functions delattr2694595 Ref: 12812694595 Ref: library/functions func-dict2694964 Ref: 12842694964 Ref: library/functions dir2695421 Ref: d332695421 Ref: library/functions divmod2698160 Ref: 1522698160 Ref: library/functions enumerate2698801 Ref: de32698801 Ref: library/functions eval2699694 Ref: b902699694 Ref: library/functions exec2702018 Ref: c442702018 Ref: library/functions filter2704623 Ref: c2e2704623 Ref: library/functions float2705424 Ref: 1872705424 Ref: library/functions grammar-token-sign2706044 Ref: 12972706044 Ref: library/functions grammar-token-infinity2706083 Ref: 12982706083 Ref: library/functions grammar-token-nan2706131 Ref: 12992706131 Ref: library/functions grammar-token-numeric-value2706166 Ref: 129a2706166 Ref: library/functions grammar-token-numeric-string2706224 Ref: 129b2706224 Ref: library/functions format2707741 Ref: 4db2707741 Ref: library/functions func-frozenset2708832 Ref: 12892708832 Ref: library/functions getattr2709307 Ref: 4482709307 Ref: library/functions globals2709770 Ref: 128c2709770 Ref: library/functions hasattr2710046 Ref: 4472710046 Ref: library/functions hash2710385 Ref: 9c42710385 Ref: library/functions help2710971 Ref: 5722710971 Ref: library/functions hex2712023 Ref: c662712023 Ref: library/functions id2713090 Ref: d862713090 Ref: library/functions input2713546 Ref: c6b2713546 Ref: library/functions int2714400 Ref: 1842714400 Ref: library/functions isinstance2716476 Ref: 44f2716476 Ref: library/functions issubclass2717064 Ref: 4502717064 Ref: library/functions iter2717450 Ref: d272717450 Ref: library/functions len2718823 Ref: 1502718823 Ref: library/functions func-list2719056 Ref: 128a2719056 Ref: library/functions locals2719277 Ref: 4552719277 Ref: library/functions map2719804 Ref: c2d2719804 Ref: library/functions max2720330 Ref: 80a2720330 Ref: library/functions func-memoryview2721524 Ref: 12822721524 Ref: library/functions min2721684 Ref: 8092721684 Ref: library/functions next2722869 Ref: 6822722869 Ref: library/functions object2723137 Ref: 2b02723137 Ref: library/functions oct2723556 Ref: c652723556 Ref: library/functions open2724328 Ref: 4f02724328 Ref: library/functions filemodes2725820 Ref: 12a02725820 Ref: library/functions open-newline-parameter2730995 Ref: 12a22730995 Ref: library/functions ord2736058 Ref: 10c62736058 Ref: library/functions pow2736380 Ref: 19a2736380 Ref: library/functions print2738007 Ref: 8862738007 Ref: library/functions property2739193 Ref: 1d72739193 Ref: library/functions func-range2741901 Ref: 128b2741901 Ref: library/functions repr2742161 Ref: 7cc2742161 Ref: library/functions reversed2742768 Ref: 18e2742768 Ref: library/functions round2743083 Ref: c6d2743083 Ref: library/functions func-set2744392 Ref: 12832744392 Ref: library/functions setattr2744850 Ref: 12852744850 Ref: library/functions slice2745267 Ref: e042745267 Ref: library/functions sorted2746048 Ref: 4442746048 Ref: library/functions staticmethod2747136 Ref: 1d92747136 Ref: library/functions func-str2748374 Ref: 12862748374 Ref: library/functions sum2748705 Ref: 1e52748705 Ref: library/functions super2749414 Ref: 4e22749414 Ref: library/functions func-tuple2753130 Ref: 12882753130 Ref: library/functions type2753357 Ref: 6082753357 Ref: library/functions vars2755051 Ref: f2d2755051 Ref: library/functions zip2755946 Ref: c322755946 Ref: library/functions __import__2757889 Ref: 6102757889 Ref: Built-in Functions-Footnote-12761064 Ref: Built-in Functions-Footnote-22761274 Ref: Built-in Functions-Footnote-32761323 Ref: Built-in Functions-Footnote-42761400 Ref: Built-in Functions-Footnote-52761449 Node: Built-in Constants2761498 Ref: library/constants doc2761630 Ref: 12b32761630 Ref: library/constants built-in-constants2761630 Ref: 12b42761630 Ref: library/constants built-in-consts2761630 Ref: 12b52761630 Ref: library/constants False2761749 Ref: 3882761749 Ref: library/constants True2761899 Ref: 4992761899 Ref: library/constants None2762046 Ref: 1572762046 Ref: library/constants NotImplemented2762325 Ref: 84c2762325 Ref: library/constants Ellipsis2763658 Ref: 12b62763658 Ref: library/constants __debug__2763854 Ref: fdd2763854 Node: Constants added by the site module2764323 Ref: library/constants constants-added-by-the-site-module2764412 Ref: 12b72764412 Ref: library/constants quit2764780 Ref: 12b82764780 Ref: library/constants exit2764807 Ref: 12b92764807 Ref: library/constants copyright2765023 Ref: 12ba2765023 Ref: library/constants credits2765043 Ref: 12bb2765043 Ref: library/constants license2765164 Ref: 12bc2765164 Node: Built-in Types2765391 Ref: library/stdtypes doc2765524 Ref: 12bd2765524 Ref: library/stdtypes bltin-types2765524 Ref: 12be2765524 Ref: library/stdtypes built-in-types2765524 Ref: 12bf2765524 Node: Truth Value Testing2766946 Ref: library/stdtypes truth2767058 Ref: 128d2767058 Ref: library/stdtypes truth-value-testing2767058 Ref: 12c02767058 Ref: Truth Value Testing-Footnote-12768130 Node: Boolean Operations — and or not2768270 Ref: library/stdtypes boolean2768405 Ref: 12c12768405 Ref: library/stdtypes boolean-operations-and-or-not2768405 Ref: 12c22768405 Node: Comparisons<2>2769734 Ref: library/stdtypes comparisons2769885 Ref: 12c32769885 Ref: library/stdtypes stdcomparisons2769885 Ref: 12c42769885 Node: Numeric Types — int float complex2772329 Ref: library/stdtypes numeric-types-int-float-complex2772461 Ref: 12c52772461 Ref: library/stdtypes typesnumeric2772461 Ref: eb32772461 Ref: Numeric Types — int float complex-Footnote-12780503 Node: Bitwise Operations on Integer Types2780622 Ref: library/stdtypes bitstring-ops2780773 Ref: 12c72780773 Ref: library/stdtypes bitwise-operations-on-integer-types2780773 Ref: 12c82780773 Node: Additional Methods on Integer Types2783127 Ref: library/stdtypes additional-methods-on-integer-types2783314 Ref: 12c92783314 Ref: library/stdtypes int bit_length2783540 Ref: 12ca2783540 Ref: library/stdtypes int to_bytes2784455 Ref: 12cb2784455 Ref: library/stdtypes int from_bytes2785865 Ref: 12cd2785865 Ref: library/stdtypes int as_integer_ratio2787077 Ref: 1862787077 Node: Additional Methods on Float2787391 Ref: library/stdtypes additional-methods-on-float2787567 Ref: 12ce2787567 Ref: library/stdtypes float as_integer_ratio2787779 Ref: fb92787779 Ref: library/stdtypes float is_integer2788035 Ref: 12cf2788035 Ref: library/stdtypes float hex2788662 Ref: fba2788662 Ref: library/stdtypes float fromhex2788912 Ref: 12d02788912 Node: Hashing of numeric types2790550 Ref: library/stdtypes hashing-of-numeric-types2790682 Ref: 12d12790682 Ref: library/stdtypes numeric-hash2790682 Ref: 12d22790682 Node: Iterator Types2794940 Ref: library/stdtypes iterator-types2795093 Ref: 12d32795093 Ref: library/stdtypes typeiter2795093 Ref: 10fe2795093 Ref: library/stdtypes container __iter__2795475 Ref: 12d42795475 Ref: library/stdtypes iterator __iter__2796209 Ref: 12d52796209 Ref: library/stdtypes iterator __next__2796547 Ref: c642796547 Node: Generator Types2797317 Ref: library/stdtypes generator-types2797383 Ref: 12d62797383 Ref: library/stdtypes id32797383 Ref: 12d72797383 Node: Sequence Types — list tuple range2797878 Ref: library/stdtypes sequence-types-list-tuple-range2798022 Ref: 12d82798022 Ref: library/stdtypes typesseq2798022 Ref: f042798022 Node: Common Sequence Operations2798488 Ref: library/stdtypes common-sequence-operations2798619 Ref: 12d92798619 Ref: library/stdtypes typesseq-common2798619 Ref: 12da2798619 Ref: Common Sequence Operations-Footnote-12807030 Node: Immutable Sequence Types2807113 Ref: library/stdtypes immutable-sequence-types2807275 Ref: 12df2807275 Ref: library/stdtypes typesseq-immutable2807275 Ref: 12e02807275 Node: Mutable Sequence Types2807808 Ref: library/stdtypes mutable-sequence-types2807952 Ref: 12e12807952 Ref: library/stdtypes typesseq-mutable2807952 Ref: 128f2807952 Node: Lists<2>2813615 Ref: library/stdtypes lists2813741 Ref: 12e22813741 Ref: library/stdtypes typesseq-list2813741 Ref: 129e2813741 Ref: library/stdtypes list2813924 Ref: 2622813924 Ref: library/stdtypes list sort2815111 Ref: 4452815111 Node: Tuples2817428 Ref: library/stdtypes tuples2817538 Ref: 12e32817538 Ref: library/stdtypes typesseq-tuple2817538 Ref: 12b12817538 Ref: library/stdtypes tuple2817901 Ref: 47e2817901 Node: Ranges2819456 Ref: library/stdtypes ranges2819549 Ref: 12e42819549 Ref: library/stdtypes typesseq-range2819549 Ref: 12a92819549 Ref: library/stdtypes range2819738 Ref: 9be2819738 Ref: library/stdtypes range start2821708 Ref: 12e52821708 Ref: library/stdtypes range stop2821838 Ref: 12e62821838 Ref: library/stdtypes range step2821909 Ref: 12e72821909 Ref: Ranges-Footnote-12823915 Node: Text Sequence Type — str2823967 Ref: library/stdtypes text-sequence-type-str2824149 Ref: 12e82824149 Ref: library/stdtypes textseq2824149 Ref: eb72824149 Ref: library/stdtypes str2825815 Ref: 3302825815 Node: String Methods<2>2827950 Ref: library/stdtypes id52828069 Ref: 12ea2828069 Ref: library/stdtypes string-methods2828069 Ref: eb82828069 Ref: library/stdtypes str capitalize2828910 Ref: 12ed2828910 Ref: library/stdtypes str casefold2829276 Ref: 6b02829276 Ref: library/stdtypes str center2829896 Ref: f312829896 Ref: library/stdtypes str count2830168 Ref: 12ef2830168 Ref: library/stdtypes str encode2830404 Ref: c372830404 Ref: library/stdtypes str endswith2831142 Ref: 7c72831142 Ref: library/stdtypes str expandtabs2831477 Ref: 12f02831477 Ref: library/stdtypes str find2832592 Ref: 79f2832592 Ref: library/stdtypes str format2833141 Ref: 4da2833141 Ref: library/stdtypes str format_map2834653 Ref: 6b12834653 Ref: library/stdtypes str index2835164 Ref: 12f12835164 Ref: library/stdtypes str isalnum2835310 Ref: 12f22835310 Ref: library/stdtypes str isalpha2835650 Ref: 12f32835650 Ref: library/stdtypes str isascii2836148 Ref: 3332836148 Ref: library/stdtypes str isdecimal2836388 Ref: 12f42836388 Ref: library/stdtypes str isdigit2836776 Ref: 12f52836776 Ref: library/stdtypes str isidentifier2837284 Ref: 12f62837284 Ref: library/stdtypes str islower2837837 Ref: 12f82837837 Ref: library/stdtypes str isnumeric2838021 Ref: 12f92838021 Ref: library/stdtypes str isprintable2838501 Ref: 6b22838501 Ref: library/stdtypes str isspace2839119 Ref: 12fa2839119 Ref: library/stdtypes str istitle2839541 Ref: 12fb2839541 Ref: library/stdtypes str isupper2839822 Ref: 12fc2839822 Ref: library/stdtypes str join2840006 Ref: 12dd2840006 Ref: library/stdtypes str ljust2840334 Ref: f302840334 Ref: library/stdtypes str lower2840621 Ref: 12ee2840621 Ref: library/stdtypes str lstrip2840840 Ref: 12fd2840840 Ref: library/stdtypes str maketrans2841354 Ref: 6b32841354 Ref: library/stdtypes str partition2842083 Ref: 7a22842083 Ref: library/stdtypes str replace2842422 Ref: 12ff2842422 Ref: library/stdtypes str rfind2842663 Ref: 7a02842663 Ref: library/stdtypes str rindex2842960 Ref: 13002842960 Ref: library/stdtypes str rjust2843115 Ref: f2f2843115 Ref: library/stdtypes str rpartition2843403 Ref: 13012843403 Ref: library/stdtypes str rsplit2843742 Ref: 13022843742 Ref: library/stdtypes str rstrip2844192 Ref: 13032844192 Ref: library/stdtypes str split2844696 Ref: 7a12844696 Ref: library/stdtypes str splitlines2846355 Ref: 13042846355 Ref: library/stdtypes str startswith2849001 Ref: 7c62849001 Ref: library/stdtypes str strip2849338 Ref: 13052849338 Ref: library/stdtypes str swapcase2850346 Ref: 13062850346 Ref: library/stdtypes str title2850563 Ref: 13072850563 Ref: library/stdtypes str translate2851616 Ref: 12fe2851616 Ref: library/stdtypes str upper2852521 Ref: 13092852521 Ref: library/stdtypes str zfill2852986 Ref: f322852986 Ref: String Methods<2>-Footnote-12853507 Ref: String Methods<2>-Footnote-22853683 Ref: String Methods<2>-Footnote-32853859 Ref: String Methods<2>-Footnote-42854035 Node: printf-style String Formatting2854211 Ref: library/stdtypes old-string-formatting2854330 Ref: eb92854330 Ref: library/stdtypes printf-style-string-formatting2854330 Ref: 130a2854330 Ref: printf-style String Formatting-Footnote-12863541 Ref: printf-style String Formatting-Footnote-22863672 Node: Binary Sequence Types — bytes bytearray memoryview2863721 Ref: library/stdtypes binary-sequence-types-bytes-bytearray-memoryview2863895 Ref: 130c2863895 Ref: library/stdtypes binaryseq2863895 Ref: 12922863895 Node: Bytes Objects2864587 Ref: library/stdtypes bytes-objects2864715 Ref: 130d2864715 Ref: library/stdtypes typebytes2864715 Ref: 12942864715 Ref: library/stdtypes bytes2865055 Ref: 3312865055 Ref: library/stdtypes bytes fromhex2867310 Ref: 32e2867310 Ref: library/stdtypes bytes hex2867917 Ref: 6312867917 Node: Bytearray Objects2870114 Ref: library/stdtypes bytearray-objects2870281 Ref: 130e2870281 Ref: library/stdtypes typebytearray2870281 Ref: 12932870281 Ref: library/stdtypes bytearray2870421 Ref: 3322870421 Ref: library/stdtypes bytearray fromhex2871459 Ref: 32f2871459 Ref: library/stdtypes bytearray hex2872095 Ref: 6322872095 Node: Bytes and Bytearray Operations2873146 Ref: library/stdtypes bytes-and-bytearray-operations2873329 Ref: 130f2873329 Ref: library/stdtypes bytes-methods2873329 Ref: 12902873329 Ref: library/stdtypes bytes count2874547 Ref: 13102874547 Ref: library/stdtypes bytearray count2874593 Ref: 13112874593 Ref: library/stdtypes bytes decode2875056 Ref: c382875056 Ref: library/stdtypes bytearray decode2875117 Ref: 13122875117 Ref: library/stdtypes bytes endswith2876002 Ref: 13132876002 Ref: library/stdtypes bytearray endswith2876054 Ref: 13142876054 Ref: library/stdtypes bytes find2876481 Ref: 13152876481 Ref: library/stdtypes bytearray find2876526 Ref: 13162876526 Ref: library/stdtypes bytes index2877332 Ref: 13172877332 Ref: library/stdtypes bytearray index2877378 Ref: 13182877378 Ref: library/stdtypes bytes join2877752 Ref: 12de2877752 Ref: library/stdtypes bytearray join2877786 Ref: 13192877786 Ref: library/stdtypes bytes maketrans2878222 Ref: c092878222 Ref: library/stdtypes bytearray maketrans2878268 Ref: c0a2878268 Ref: library/stdtypes bytes partition2878634 Ref: 131b2878634 Ref: library/stdtypes bytearray partition2878668 Ref: 131c2878668 Ref: library/stdtypes bytes replace2879155 Ref: 131d2879155 Ref: library/stdtypes bytearray replace2879201 Ref: 131e2879201 Ref: library/stdtypes bytes rfind2879721 Ref: 131f2879721 Ref: library/stdtypes bytearray rfind2879767 Ref: 13202879767 Ref: library/stdtypes bytes rindex2880297 Ref: 13212880297 Ref: library/stdtypes bytearray rindex2880344 Ref: 13222880344 Ref: library/stdtypes bytes rpartition2880727 Ref: 13232880727 Ref: library/stdtypes bytearray rpartition2880762 Ref: 13242880762 Ref: library/stdtypes bytes startswith2881249 Ref: 13252881249 Ref: library/stdtypes bytearray startswith2881303 Ref: 13262881303 Ref: library/stdtypes bytes translate2881739 Ref: 131a2881739 Ref: library/stdtypes bytearray translate2881790 Ref: c912881790 Ref: library/stdtypes bytes center2882811 Ref: 13272882811 Ref: library/stdtypes bytearray center2882856 Ref: 13282882856 Ref: library/stdtypes bytes ljust2883357 Ref: 13292883357 Ref: library/stdtypes bytearray ljust2883401 Ref: 132a2883401 Ref: library/stdtypes bytes lstrip2883907 Ref: 132b2883907 Ref: library/stdtypes bytearray lstrip2883942 Ref: 132c2883942 Ref: library/stdtypes bytes rjust2884843 Ref: 132d2884843 Ref: library/stdtypes bytearray rjust2884887 Ref: 132e2884887 Ref: library/stdtypes bytes rsplit2885394 Ref: 132f2885394 Ref: library/stdtypes bytearray rsplit2885443 Ref: 13302885443 Ref: library/stdtypes bytes rstrip2885957 Ref: 13322885957 Ref: library/stdtypes bytearray rstrip2885992 Ref: 13332885992 Ref: library/stdtypes bytes split2886883 Ref: 13342886883 Ref: library/stdtypes bytearray split2886931 Ref: 13312886931 Ref: library/stdtypes bytes strip2888854 Ref: 13352888854 Ref: library/stdtypes bytearray strip2888888 Ref: 13362888888 Ref: library/stdtypes bytes capitalize2890075 Ref: 13372890075 Ref: library/stdtypes bytearray capitalize2890107 Ref: 13382890107 Ref: library/stdtypes bytes expandtabs2890516 Ref: 13392890516 Ref: library/stdtypes bytearray expandtabs2890557 Ref: 133a2890557 Ref: library/stdtypes bytes isalnum2891899 Ref: 133b2891899 Ref: library/stdtypes bytearray isalnum2891928 Ref: 133c2891928 Ref: library/stdtypes bytes isalpha2892490 Ref: 133d2892490 Ref: library/stdtypes bytearray isalpha2892519 Ref: 133e2892519 Ref: library/stdtypes bytes isascii2892956 Ref: 133f2892956 Ref: library/stdtypes bytearray isascii2892985 Ref: 13402892985 Ref: library/stdtypes bytes isdigit2893200 Ref: 13412893200 Ref: library/stdtypes bytearray isdigit2893229 Ref: 13422893229 Ref: library/stdtypes bytes islower2893601 Ref: 13432893601 Ref: library/stdtypes bytearray islower2893630 Ref: 13442893630 Ref: library/stdtypes bytes isspace2894168 Ref: 13452894168 Ref: library/stdtypes bytearray isspace2894197 Ref: 13462894197 Ref: library/stdtypes bytes istitle2894529 Ref: 13472894529 Ref: library/stdtypes bytearray istitle2894558 Ref: 13482894558 Ref: library/stdtypes bytes isupper2894931 Ref: 134a2894931 Ref: library/stdtypes bytearray isupper2894960 Ref: 134b2894960 Ref: library/stdtypes bytes lower2895514 Ref: 134c2895514 Ref: library/stdtypes bytearray lower2895541 Ref: 134d2895541 Ref: library/stdtypes bytes splitlines2896180 Ref: 134e2896180 Ref: library/stdtypes bytearray splitlines2896226 Ref: 134f2896226 Ref: library/stdtypes bytes swapcase2897175 Ref: 13502897175 Ref: library/stdtypes bytearray swapcase2897205 Ref: 13512897205 Ref: library/stdtypes bytes title2898135 Ref: 13492898135 Ref: library/stdtypes bytearray title2898162 Ref: 13522898162 Ref: library/stdtypes bytes upper2899787 Ref: 13532899787 Ref: library/stdtypes bytearray upper2899814 Ref: 13542899814 Ref: library/stdtypes bytes zfill2900453 Ref: 13552900453 Ref: library/stdtypes bytearray zfill2900485 Ref: 13562900485 Node: printf-style Bytes Formatting2901195 Ref: library/stdtypes bytes-formatting2901373 Ref: 6502901373 Ref: library/stdtypes printf-style-bytes-formatting2901373 Ref: 13572901373 Ref: printf-style Bytes Formatting-Footnote-12910866 Ref: printf-style Bytes Formatting-Footnote-22910997 Ref: printf-style Bytes Formatting-Footnote-32911046 Node: Memory Views2911095 Ref: library/stdtypes memory-views2911234 Ref: 13582911234 Ref: library/stdtypes typememoryview2911234 Ref: 129f2911234 Ref: library/stdtypes memoryview2911432 Ref: 25c2911432 Ref: library/stdtypes memoryview __eq__2915196 Ref: 135c2915196 Ref: library/stdtypes memoryview tobytes2917198 Ref: 135d2917198 Ref: library/stdtypes memoryview hex2918301 Ref: 6332918301 Ref: library/stdtypes memoryview tolist2918822 Ref: 13592918822 Ref: library/stdtypes memoryview toreadonly2919384 Ref: 135e2919384 Ref: library/stdtypes memoryview release2919996 Ref: b3d2919996 Ref: library/stdtypes memoryview cast2921362 Ref: 135f2921362 Ref: library/stdtypes memoryview obj2924381 Ref: 13612924381 Ref: library/stdtypes memoryview nbytes2924619 Ref: 13622924619 Ref: library/stdtypes memoryview readonly2925745 Ref: 13632925745 Ref: library/stdtypes memoryview format2925837 Ref: 135b2925837 Ref: library/stdtypes memoryview itemsize2926375 Ref: 135a2926375 Ref: library/stdtypes memoryview ndim2926751 Ref: 13642926751 Ref: library/stdtypes memoryview shape2926892 Ref: 13652926892 Ref: library/stdtypes memoryview strides2927147 Ref: 13662927147 Ref: library/stdtypes memoryview suboffsets2927437 Ref: 13672927437 Ref: library/stdtypes memoryview c_contiguous2927562 Ref: 13682927562 Ref: library/stdtypes memoryview f_contiguous2927714 Ref: 13692927714 Ref: library/stdtypes memoryview contiguous2927872 Ref: 136a2927872 Ref: Memory Views-Footnote-12928056 Node: Set Types — set frozenset2928105 Ref: library/stdtypes set-types-set-frozenset2928275 Ref: 136b2928275 Ref: library/stdtypes types-set2928275 Ref: 129c2928275 Ref: library/stdtypes set2929825 Ref: b6f2929825 Ref: library/stdtypes frozenset2929853 Ref: bee2929853 Ref: library/stdtypes frozenset isdisjoint2930889 Ref: 136c2930889 Ref: library/stdtypes frozenset issubset2931097 Ref: 136d2931097 Ref: library/stdtypes frozenset issuperset2931376 Ref: 136e2931376 Ref: library/stdtypes frozenset union2931659 Ref: 136f2931659 Ref: library/stdtypes frozenset intersection2931800 Ref: 13702931800 Ref: library/stdtypes frozenset difference2931963 Ref: 13712931963 Ref: library/stdtypes frozenset symmetric_difference2932129 Ref: 13722932129 Ref: library/stdtypes frozenset copy2932301 Ref: 13732932301 Ref: library/stdtypes frozenset update2934542 Ref: 13742934542 Ref: library/stdtypes frozenset intersection_update2934674 Ref: 13752934674 Ref: library/stdtypes frozenset difference_update2934846 Ref: 13762934846 Ref: library/stdtypes frozenset symmetric_difference_update2934991 Ref: 13772934991 Ref: library/stdtypes frozenset add2935173 Ref: 13782935173 Ref: library/stdtypes frozenset remove2935244 Ref: 13792935244 Ref: library/stdtypes frozenset discard2935401 Ref: 137a2935401 Ref: library/stdtypes frozenset pop2935498 Ref: 137b2935498 Ref: library/stdtypes frozenset clear2935647 Ref: 137c2935647 Node: Mapping Types — dict2936207 Ref: library/stdtypes mapping-types-dict2936346 Ref: 137d2936346 Ref: library/stdtypes typesmapping2936346 Ref: 2fc2936346 Ref: library/stdtypes dict2937579 Ref: 1b82937579 Ref: library/stdtypes dict clear2941895 Ref: 137e2941895 Ref: library/stdtypes dict copy2941971 Ref: 4462941971 Ref: library/stdtypes dict fromkeys2942049 Ref: 137f2942049 Ref: library/stdtypes dict get2942591 Ref: 13802942591 Ref: library/stdtypes dict items2942846 Ref: c2b2942846 Ref: library/stdtypes dict keys2943020 Ref: c2a2943020 Ref: library/stdtypes dict pop2943165 Ref: 13822943165 Ref: library/stdtypes dict popitem2943418 Ref: 13832943418 Ref: library/stdtypes dict setdefault2944191 Ref: 9bf2944191 Ref: library/stdtypes dict update2944421 Ref: dc92944421 Ref: library/stdtypes dict values2944905 Ref: c2c2944905 Node: Dictionary view objects2947012 Ref: library/stdtypes dict-views2947094 Ref: 13812947094 Ref: library/stdtypes dictionary-view-objects2947094 Ref: 13842947094 Node: Context Manager Types2949996 Ref: library/stdtypes context-manager-types2950128 Ref: 13862950128 Ref: library/stdtypes typecontextmanager2950128 Ref: 112a2950128 Ref: library/stdtypes contextmanager __enter__2950493 Ref: 13872950493 Ref: library/stdtypes contextmanager __exit__2951492 Ref: 13892951492 Node: Other Built-in Types2953878 Ref: library/stdtypes other-built-in-types2954006 Ref: 138a2954006 Ref: library/stdtypes typesother2954006 Ref: 138b2954006 Node: Modules<2>2954411 Ref: library/stdtypes modules2954514 Ref: 138c2954514 Ref: library/stdtypes typesmodules2954514 Ref: 138d2954514 Node: Classes and Class Instances2955667 Ref: library/stdtypes classes-and-class-instances2955788 Ref: 138e2955788 Ref: library/stdtypes typesobjects2955788 Ref: 138f2955788 Node: Functions2955952 Ref: library/stdtypes functions2956070 Ref: 13902956070 Ref: library/stdtypes typesfunctions2956070 Ref: 13912956070 Node: Methods2956533 Ref: library/stdtypes methods2956636 Ref: 13922956636 Ref: library/stdtypes typesmethods2956636 Ref: 13932956636 Node: Code Objects2958407 Ref: library/stdtypes bltin-code-objects2958513 Ref: 13942958513 Ref: library/stdtypes code-objects2958513 Ref: 13952958513 Node: Type Objects2959219 Ref: library/stdtypes bltin-type-objects2959333 Ref: 12b22959333 Ref: library/stdtypes type-objects2959333 Ref: 13962959333 Node: The Null Object2959684 Ref: library/stdtypes bltin-null-object2959805 Ref: 13972959805 Ref: library/stdtypes the-null-object2959805 Ref: 13982959805 Node: The Ellipsis Object2960120 Ref: library/stdtypes bltin-ellipsis-object2960254 Ref: 13992960254 Ref: library/stdtypes the-ellipsis-object2960254 Ref: 139a2960254 Node: The NotImplemented Object2960622 Ref: library/stdtypes bltin-notimplemented-object2960755 Ref: 139b2960755 Ref: library/stdtypes the-notimplemented-object2960755 Ref: 139c2960755 Node: Boolean Values2961158 Ref: library/stdtypes bltin-boolean-values2961288 Ref: 128e2961288 Ref: library/stdtypes boolean-values2961288 Ref: 139d2961288 Node: Internal Objects2961911 Ref: library/stdtypes internal-objects2962007 Ref: 139e2962007 Ref: library/stdtypes typesinternal2962007 Ref: 139f2962007 Node: Special Attributes2962203 Ref: library/stdtypes special-attributes2962301 Ref: 13a02962301 Ref: library/stdtypes specialattrs2962301 Ref: 13a12962301 Ref: library/stdtypes object __dict__2962540 Ref: 4fc2962540 Ref: library/stdtypes instance __class__2962671 Ref: e0a2962671 Ref: library/stdtypes class __bases__2962757 Ref: e092962757 Ref: library/stdtypes definition __name__2962840 Ref: c672962840 Ref: library/stdtypes definition __qualname__2962963 Ref: 10c92962963 Ref: library/stdtypes class __mro__2963139 Ref: 12af2963139 Ref: library/stdtypes class mro2963293 Ref: 13a22963293 Ref: library/stdtypes class __subclasses__2963527 Ref: 13a32963527 Node: Built-in Exceptions2963790 Ref: library/exceptions doc2963929 Ref: 13a42963929 Ref: library/exceptions bltin-exceptions2963929 Ref: f432963929 Ref: library/exceptions built-in-exceptions2963929 Ref: 13a52963929 Node: Base classes2967216 Ref: library/exceptions base-classes2967312 Ref: 13a62967312 Ref: library/exceptions BaseException2967431 Ref: 1a82967431 Ref: library/exceptions BaseException args2967816 Ref: 13a72967816 Ref: library/exceptions BaseException with_traceback2968184 Ref: 13a82968184 Ref: library/exceptions Exception2968593 Ref: 1a92968593 Ref: library/exceptions ArithmeticError2968777 Ref: 13a92968777 Ref: library/exceptions BufferError2969005 Ref: 13ab2969005 Ref: library/exceptions LookupError2969117 Ref: 13082969117 Node: Concrete exceptions2969383 Ref: library/exceptions concrete-exceptions2969496 Ref: 13ad2969496 Ref: library/exceptions AssertionError2969619 Ref: 12232969619 Ref: library/exceptions AttributeError2969707 Ref: 39b2969707 Ref: library/exceptions EOFError2969977 Ref: c6c2969977 Ref: library/exceptions FloatingPointError2970254 Ref: 13aa2970254 Ref: library/exceptions GeneratorExit2970315 Ref: d322970315 Ref: library/exceptions ImportError2970637 Ref: 3342970637 Ref: library/exceptions ModuleNotFoundError2971212 Ref: 39a2971212 Ref: library/exceptions IndexError2971474 Ref: e752971474 Ref: library/exceptions KeyError2971701 Ref: 2c72971701 Ref: library/exceptions KeyboardInterrupt2971818 Ref: 1972971818 Ref: library/exceptions MemoryError2972208 Ref: 13af2972208 Ref: library/exceptions NameError2972789 Ref: d7b2972789 Ref: library/exceptions NotImplementedError2973011 Ref: 60e2973011 Ref: library/exceptions OSError2973855 Ref: 1d32973855 Ref: library/exceptions OSError errno2974892 Ref: 13b12974892 Ref: library/exceptions OSError winerror2974984 Ref: 13b22974984 Ref: library/exceptions OSError strerror2975563 Ref: 13b32975563 Ref: library/exceptions OSError filename2975799 Ref: 13b42975799 Ref: library/exceptions OSError filename22975828 Ref: 13b52975828 Ref: library/exceptions OverflowError2976806 Ref: 9602976806 Ref: library/exceptions RecursionError2977299 Ref: 6342977299 Ref: library/exceptions ReferenceError2977621 Ref: e4d2977621 Ref: library/exceptions RuntimeError2977947 Ref: 2ba2977947 Ref: library/exceptions StopIteration2978149 Ref: 4862978149 Ref: library/exceptions StopAsyncIteration2979480 Ref: 10cd2979480 Ref: library/exceptions SyntaxError2979672 Ref: 4582979672 Ref: library/exceptions IndentationError2980194 Ref: e782980194 Ref: library/exceptions TabError2980347 Ref: e772980347 Ref: library/exceptions SystemError2980508 Ref: 5fb2980508 Ref: library/exceptions SystemExit2981151 Ref: 5fc2981151 Ref: library/exceptions SystemExit code2982447 Ref: 13b72982447 Ref: library/exceptions TypeError2982589 Ref: 1922982589 Ref: library/exceptions UnboundLocalError2983418 Ref: e762983418 Ref: library/exceptions UnicodeError2983636 Ref: c3b2983636 Ref: library/exceptions UnicodeError encoding2983997 Ref: 13b82983997 Ref: library/exceptions UnicodeError reason2984086 Ref: 13b92984086 Ref: library/exceptions UnicodeError object2984171 Ref: 13ba2984171 Ref: library/exceptions UnicodeError start2984267 Ref: 13bb2984267 Ref: library/exceptions UnicodeError end2984359 Ref: 13bc2984359 Ref: library/exceptions UnicodeEncodeError2984455 Ref: 1fc2984455 Ref: library/exceptions UnicodeDecodeError2984607 Ref: 1fd2984607 Ref: library/exceptions UnicodeTranslateError2984759 Ref: 13bd2984759 Ref: library/exceptions ValueError2984917 Ref: 1fb2984917 Ref: library/exceptions ZeroDivisionError2985169 Ref: f422985169 Ref: library/exceptions EnvironmentError2985526 Ref: 9932985526 Ref: library/exceptions IOError2985559 Ref: 9922985559 Ref: library/exceptions WindowsError2985583 Ref: 9942985583 Ref: Concrete exceptions-Footnote-12985709 Ref: Concrete exceptions-Footnote-22985758 Node: OS exceptions2985807 Ref: library/exceptions os-exceptions2985876 Ref: 13b02985876 Ref: library/exceptions BlockingIOError2986037 Ref: 9972986037 Ref: library/exceptions BlockingIOError characters_written2986393 Ref: 13be2986393 Ref: library/exceptions ChildProcessError2986648 Ref: 9982986648 Ref: library/exceptions ConnectionError2986787 Ref: 6e62986787 Ref: library/exceptions BrokenPipeError2987035 Ref: 99d2987035 Ref: library/exceptions ConnectionAbortedError2987334 Ref: 99e2987334 Ref: library/exceptions ConnectionRefusedError2987536 Ref: 99f2987536 Ref: library/exceptions ConnectionResetError2987738 Ref: 9a02987738 Ref: library/exceptions FileExistsError2987921 Ref: 9582987921 Ref: library/exceptions FileNotFoundError2988077 Ref: 7c02988077 Ref: library/exceptions InterruptedError2988229 Ref: 6592988229 Ref: library/exceptions IsADirectoryError2988635 Ref: 9992988635 Ref: library/exceptions NotADirectoryError2988814 Ref: 99a2988814 Ref: library/exceptions PermissionError2989028 Ref: 5ff2989028 Ref: library/exceptions ProcessLookupError2989246 Ref: 99b2989246 Ref: library/exceptions TimeoutError2989378 Ref: 99c2989378 Ref: OS exceptions-Footnote-12989715 Ref: OS exceptions-Footnote-22989764 Node: Warnings2989813 Ref: library/exceptions warning-categories-as-exceptions2989933 Ref: 13bf2989933 Ref: library/exceptions warnings2989933 Ref: 13c02989933 Ref: library/exceptions Warning2990094 Ref: 13c22990094 Ref: library/exceptions UserWarning2990159 Ref: 13c32990159 Ref: library/exceptions DeprecationWarning2990241 Ref: 2782990241 Ref: library/exceptions PendingDeprecationWarning2990399 Ref: 2792990399 Ref: library/exceptions SyntaxWarning2990793 Ref: 1912990793 Ref: library/exceptions RuntimeWarning2990875 Ref: 2c02990875 Ref: library/exceptions FutureWarning2990968 Ref: 3252990968 Ref: library/exceptions ImportWarning2991155 Ref: 5d82991155 Ref: library/exceptions UnicodeWarning2991258 Ref: d872991258 Ref: library/exceptions BytesWarning2991339 Ref: 4b52991339 Ref: library/exceptions ResourceWarning2991458 Ref: 4d02991458 Node: Exception hierarchy2991619 Ref: library/exceptions exception-hierarchy2991711 Ref: 13c42991711 Ref: library/text stringservices2993955 Ref: 12e92993955 Node: Text Processing Services2993956 Ref: library/text doc2994101 Ref: 13c52994101 Ref: library/text text-processing-services2994101 Ref: 13c62994101 Ref: library/text textservices2994101 Ref: 12ec2994101 Node: string — Common string operations2994888 Ref: library/string doc2995029 Ref: 13c82995029 Ref: library/string module-string2995029 Ref: f62995029 Ref: library/string string-common-string-operations2995029 Ref: 13c92995029 Ref: string — Common string operations-Footnote-12995471 Node: String constants2995536 Ref: library/string string-constants2995657 Ref: 13ca2995657 Ref: library/string string ascii_letters2995751 Ref: c5c2995751 Ref: library/string string ascii_lowercase2995950 Ref: 13cb2995950 Ref: library/string string ascii_uppercase2996110 Ref: 13cc2996110 Ref: library/string string digits2996270 Ref: 13cd2996270 Ref: library/string string hexdigits2996332 Ref: 13ce2996332 Ref: library/string string octdigits2996409 Ref: 13cf2996409 Ref: library/string string punctuation2996472 Ref: 13d02996472 Ref: library/string string printable2996647 Ref: 13d12996647 Ref: library/string string whitespace2996875 Ref: 13d22996875 Node: Custom String Formatting2997081 Ref: library/string custom-string-formatting2997231 Ref: 13d32997231 Ref: library/string string-formatting2997231 Ref: 12eb2997231 Ref: library/string string Formatter2997678 Ref: 7b52997678 Ref: library/string string Formatter format2997779 Ref: 48c2997779 Ref: library/string string Formatter vformat2998140 Ref: 13d42998140 Ref: library/string string Formatter parse2998851 Ref: 13d52998851 Ref: library/string string Formatter get_field2999607 Ref: 13d62999607 Ref: library/string string Formatter get_value3000156 Ref: 13d73000156 Ref: library/string string Formatter check_unused_args3001392 Ref: 13d83001392 Ref: library/string string Formatter format_field3001996 Ref: 13d93001996 Ref: library/string string Formatter convert_field3002222 Ref: 13da3002222 Ref: Custom String Formatting-Footnote-13002597 Ref: Custom String Formatting-Footnote-23002646 Node: Format String Syntax3002695 Ref: library/string format-string-syntax3002845 Ref: 13db3002845 Ref: library/string formatstrings3002845 Ref: d1a3002845 Ref: library/string grammar-token-replacement-field3003646 Ref: 13dc3003646 Ref: library/string grammar-token-field-name3003734 Ref: 13dd3003734 Ref: library/string grammar-token-arg-name3003821 Ref: 13de3003821 Ref: library/string grammar-token-attribute-name3003875 Ref: 13df3003875 Ref: library/string grammar-token-element-index3003918 Ref: 13e03003918 Ref: library/string grammar-token-index-string3003972 Ref: 13e13003972 Ref: library/string grammar-token-conversion3004040 Ref: 13e23004040 Ref: library/string grammar-token-format-spec3004088 Ref: 13e33004088 Node: Format Specification Mini-Language3008085 Ref: library/string format-specification-mini-language3008200 Ref: 13e53008200 Ref: library/string formatspec3008200 Ref: 4de3008200 Ref: library/string id13009097 Ref: 13e63009097 Ref: library/string grammar-token-fill3009190 Ref: 13e73009190 Ref: library/string grammar-token-align3009231 Ref: 13e83009231 Ref: library/string grammar-token-sign3009278 Ref: 13e93009278 Ref: library/string grammar-token-width3009319 Ref: 13ea3009319 Ref: library/string grammar-token-grouping-option3009351 Ref: 13eb3009351 Ref: library/string grammar-token-precision3009386 Ref: 13ec3009386 Ref: library/string grammar-token-type3009418 Ref: 13ed3009418 Ref: Format Specification Mini-Language-Footnote-13022169 Ref: Format Specification Mini-Language-Footnote-23022218 Node: Format examples3022267 Ref: library/string format-examples3022382 Ref: 13ee3022382 Ref: library/string formatexamples3022382 Ref: 13e43022382 Node: Template strings3026910 Ref: library/string id23027052 Ref: 13ef3027052 Ref: library/string template-strings3027052 Ref: 130b3027052 Ref: library/string string Template3028513 Ref: 3eb3028513 Ref: library/string string Template substitute3028633 Ref: f943028633 Ref: library/string string Template safe_substitute3029118 Ref: f953029118 Ref: library/string string Template template3030152 Ref: 13f03030152 Ref: Template strings-Footnote-13033928 Ref: Template strings-Footnote-23033977 Node: Helper functions3034028 Ref: library/string helper-functions3034141 Ref: 13f13034141 Ref: library/string string capwords3034192 Ref: 13f23034192 Node: re — Regular expression operations3034678 Ref: library/re doc3034868 Ref: 13f33034868 Ref: library/re module-re3034868 Ref: dd3034868 Ref: library/re re-regular-expression-operations3034868 Ref: 13f43034868 Ref: re — Regular expression operations-Footnote-13037442 Ref: re — Regular expression operations-Footnote-23037503 Node: Regular Expression Syntax3037543 Ref: library/re re-syntax3037665 Ref: 13f53037665 Ref: library/re regular-expression-syntax3037665 Ref: 13f63037665 Ref: Regular Expression Syntax-Footnote-13061278 Node: Module Contents3061320 Ref: library/re contents-of-module-re3061477 Ref: 14013061477 Ref: library/re module-contents3061477 Ref: 14023061477 Ref: library/re re compile3061892 Ref: 44a3061892 Ref: library/re re A3063020 Ref: 13fb3063020 Ref: library/re re ASCII3063035 Ref: 3c83063035 Ref: library/re re DEBUG3063664 Ref: 14063063664 Ref: library/re re I3063779 Ref: 13fc3063779 Ref: library/re re IGNORECASE3063794 Ref: 14073063794 Ref: library/re re L3064783 Ref: 13fd3064783 Ref: library/re re LOCALE3064798 Ref: 3c93064798 Ref: library/re re M3065739 Ref: 13fe3065739 Ref: library/re re MULTILINE3065754 Ref: 13fa3065754 Ref: library/re re S3066339 Ref: 13ff3066339 Ref: library/re re DOTALL3066354 Ref: 13f93066354 Ref: library/re re X3066590 Ref: 14003066590 Ref: library/re re VERBOSE3066605 Ref: 14083066605 Ref: library/re re search3067621 Ref: bb23067621 Ref: library/re re match3068025 Ref: bb33068025 Ref: library/re re fullmatch3068676 Ref: 89b3068676 Ref: library/re re split3069005 Ref: 3ca3069005 Ref: library/re re findall3070874 Ref: 9633070874 Ref: library/re re finditer3071417 Ref: 140a3071417 Ref: library/re re sub3071855 Ref: 47b3071855 Ref: library/re re subn3075036 Ref: 7343075036 Ref: library/re re escape3075372 Ref: 4953075372 Ref: library/re re purge3076858 Ref: 140b3076858 Ref: library/re re error3076927 Ref: 7353076927 Ref: library/re re error msg3077360 Ref: 7363077360 Ref: library/re re error pattern3077427 Ref: 7373077427 Ref: library/re re error pos3077499 Ref: 7383077499 Ref: library/re re error lineno3077614 Ref: 7393077614 Ref: library/re re error colno3077706 Ref: 73a3077706 Node: Regular Expression Objects3077858 Ref: library/re re-objects3078003 Ref: 89c3078003 Ref: library/re regular-expression-objects3078003 Ref: 140c3078003 Ref: library/re re Pattern search3078157 Ref: 14053078157 Ref: library/re re Pattern match3079621 Ref: 14043079621 Ref: library/re re Pattern fullmatch3080480 Ref: 140d3080480 Ref: library/re re Pattern split3081277 Ref: 140e3081277 Ref: library/re re Pattern findall3081411 Ref: 140f3081411 Ref: library/re re Pattern finditer3081672 Ref: 14103081672 Ref: library/re re Pattern sub3081936 Ref: 14113081936 Ref: library/re re Pattern subn3082069 Ref: 14123082069 Ref: library/re re Pattern flags3082204 Ref: 14133082204 Ref: library/re re Pattern groups3082471 Ref: 14143082471 Ref: library/re re Pattern groupindex3082555 Ref: 14153082555 Ref: library/re re Pattern pattern3082769 Ref: 14163082769 Node: Match Objects3083028 Ref: library/re id23083185 Ref: 14173083185 Ref: library/re match-objects3083185 Ref: 89d3083185 Ref: library/re re Match expand3083598 Ref: 14183083598 Ref: library/re re Match group3084120 Ref: 14193084120 Ref: library/re re Match __getitem__3086388 Ref: 141a3086388 Ref: library/re re Match groups3086863 Ref: 141b3086863 Ref: library/re re Match groupdict3087709 Ref: 141c3087709 Ref: library/re re Match start3088176 Ref: 141d3088176 Ref: library/re re Match end3088210 Ref: 141e3088210 Ref: library/re re Match span3089257 Ref: 141f3089257 Ref: library/re re Match pos3089510 Ref: 14203089510 Ref: library/re re Match endpos3089770 Ref: 14213089770 Ref: library/re re Match lastindex3090024 Ref: 14223090024 Ref: library/re re Match lastgroup3090423 Ref: 14233090423 Ref: library/re re Match re3090596 Ref: 14243090596 Ref: library/re re Match string3090763 Ref: 14253090763 Node: Regular Expression Examples3091001 Ref: library/re re-examples3091123 Ref: bf43091123 Ref: library/re regular-expression-examples3091123 Ref: 14263091123 Node: Checking for a Pair3091467 Ref: library/re checking-for-a-pair3091575 Ref: 14273091575 Node: Simulating scanf3093672 Ref: library/re simulating-scanf3093804 Ref: 14283093804 Node: search vs match3095872 Ref: library/re id33096003 Ref: 14293096003 Ref: library/re search-vs-match3096003 Ref: 14093096003 Node: Making a Phonebook3097217 Ref: library/re making-a-phonebook3097344 Ref: 142a3097344 Node: Text Munging3099523 Ref: library/re text-munging3099654 Ref: 142b3099654 Node: Finding all Adverbs3100478 Ref: library/re finding-all-adverbs3100630 Ref: 142c3100630 Node: Finding all Adverbs and their Positions3101085 Ref: library/re finding-all-adverbs-and-their-positions3101244 Ref: 142d3101244 Node: Raw String Notation3101946 Ref: library/re raw-string-notation3102105 Ref: 142e3102105 Node: Writing a Tokenizer3103032 Ref: library/re writing-a-tokenizer3103143 Ref: 142f3103143 Ref: library/re frie093106514 Ref: 13f73106514 Ref: Writing a Tokenizer-Footnote-13106794 Node: difflib — Helpers for computing deltas3106849 Ref: library/difflib doc3107042 Ref: 14303107042 Ref: library/difflib difflib-helpers-for-computing-deltas3107042 Ref: 14313107042 Ref: library/difflib module-difflib3107042 Ref: 373107042 Ref: library/difflib difflib Differ3109539 Ref: 14323109539 Ref: library/difflib difflib HtmlDiff3110666 Ref: 14333110666 Ref: library/difflib difflib HtmlDiff __init__3111036 Ref: 14343111036 Ref: library/difflib difflib HtmlDiff make_file3111849 Ref: 6c93111849 Ref: library/difflib difflib HtmlDiff make_table3113532 Ref: 14363113532 Ref: library/difflib difflib context_diff3114114 Ref: 14373114114 Ref: library/difflib difflib get_close_matches3116056 Ref: 143b3116056 Ref: library/difflib difflib ndiff3117220 Ref: 14353117220 Ref: library/difflib difflib restore3118870 Ref: 143e3118870 Ref: library/difflib difflib unified_diff3119613 Ref: 14403119613 Ref: library/difflib difflib diff_bytes3121532 Ref: 6ca3121532 Ref: library/difflib difflib IS_LINE_JUNK3122424 Ref: 143c3122424 Ref: library/difflib difflib IS_CHARACTER_JUNK3122726 Ref: 143d3122726 Ref: difflib — Helpers for computing deltas-Footnote-13123386 Ref: difflib — Helpers for computing deltas-Footnote-23123452 Ref: difflib — Helpers for computing deltas-Footnote-33123541 Node: SequenceMatcher Objects3123573 Ref: library/difflib sequence-matcher3123706 Ref: 14413123706 Ref: library/difflib sequencematcher-objects3123706 Ref: 14423123706 Ref: library/difflib difflib SequenceMatcher3123832 Ref: 94f3123832 Ref: library/difflib difflib SequenceMatcher set_seqs3125356 Ref: 14433125356 Ref: library/difflib difflib SequenceMatcher set_seq13125774 Ref: 14453125774 Ref: library/difflib difflib SequenceMatcher set_seq23125917 Ref: 14443125917 Ref: library/difflib difflib SequenceMatcher find_longest_match3126060 Ref: 14463126060 Ref: library/difflib difflib SequenceMatcher get_matching_blocks3128143 Ref: 14473128143 Ref: library/difflib difflib SequenceMatcher get_opcodes3129060 Ref: 14483129060 Ref: library/difflib difflib SequenceMatcher get_grouped_opcodes3131047 Ref: 14493131047 Ref: library/difflib difflib SequenceMatcher ratio3131479 Ref: 144a3131479 Ref: library/difflib difflib SequenceMatcher quick_ratio3132502 Ref: 144b3132502 Ref: library/difflib difflib SequenceMatcher real_quick_ratio3132622 Ref: 144c3132622 Node: SequenceMatcher Examples3133133 Ref: library/difflib id13133289 Ref: 144d3133289 Ref: library/difflib sequencematcher-examples3133289 Ref: 144e3133289 Ref: SequenceMatcher Examples-Footnote-13134994 Node: Differ Objects3135047 Ref: library/difflib differ-objects3135194 Ref: 144f3135194 Ref: library/difflib id23135194 Ref: 14503135194 Ref: library/difflib difflib Differ compare3136600 Ref: 143f3136600 Node: Differ Example3137124 Ref: library/difflib differ-example3137282 Ref: 14513137282 Ref: library/difflib differ-examples3137282 Ref: 14523137282 Node: A command-line interface to difflib3139540 Ref: library/difflib a-command-line-interface-to-difflib3139675 Ref: 14533139675 Ref: library/difflib difflib-interface3139675 Ref: 143a3139675 Node: textwrap — Text wrapping and filling3142430 Ref: library/textwrap doc3142619 Ref: 14543142619 Ref: library/textwrap module-textwrap3142619 Ref: 1083142619 Ref: library/textwrap textwrap-text-wrapping-and-filling3142619 Ref: 14553142619 Ref: library/textwrap textwrap wrap3143151 Ref: 14563143151 Ref: library/textwrap textwrap fill3143652 Ref: 14583143652 Ref: library/textwrap textwrap shorten3144012 Ref: 8ed3144012 Ref: library/textwrap textwrap dedent3145147 Ref: 145d3145147 Ref: library/textwrap textwrap indent3146083 Ref: aa83146083 Ref: library/textwrap textwrap TextWrapper3147419 Ref: 8ea3147419 Ref: library/textwrap textwrap TextWrapper width3148095 Ref: 145f3148095 Ref: library/textwrap textwrap TextWrapper expand_tabs3148417 Ref: 145a3148417 Ref: library/textwrap textwrap TextWrapper tabsize3148620 Ref: 14593148620 Ref: library/textwrap textwrap TextWrapper replace_whitespace3148908 Ref: 145c3148908 Ref: library/textwrap textwrap TextWrapper drop_whitespace3149871 Ref: 145b3149871 Ref: library/textwrap textwrap TextWrapper initial_indent3150285 Ref: 14603150285 Ref: library/textwrap textwrap TextWrapper subsequent_indent3150520 Ref: 14613150520 Ref: library/textwrap textwrap TextWrapper fix_sentence_endings3150747 Ref: 14623150747 Ref: library/textwrap textwrap TextWrapper break_long_words3151968 Ref: 145e3151968 Ref: library/textwrap textwrap TextWrapper break_on_hyphens3152458 Ref: 14633152458 Ref: library/textwrap textwrap TextWrapper max_lines3152990 Ref: 8eb3152990 Ref: library/textwrap textwrap TextWrapper placeholder3153235 Ref: 8ec3153235 Ref: library/textwrap textwrap TextWrapper wrap3153549 Ref: 14573153549 Ref: library/textwrap textwrap TextWrapper fill3153971 Ref: 14643153971 Ref: textwrap — Text wrapping and filling-Footnote-13154158 Node: unicodedata — Unicode Database3154225 Ref: library/unicodedata doc3154416 Ref: 14653154416 Ref: library/unicodedata module-unicodedata3154416 Ref: 11a3154416 Ref: library/unicodedata unicodedata-unicode-database3154416 Ref: 14663154416 Ref: library/unicodedata unicodedata lookup3154938 Ref: 9bd3154938 Ref: library/unicodedata unicodedata name3155255 Ref: 14673155255 Ref: library/unicodedata unicodedata decimal3155481 Ref: 14683155481 Ref: library/unicodedata unicodedata digit3155724 Ref: 14693155724 Ref: library/unicodedata unicodedata numeric3155962 Ref: bf93155962 Ref: library/unicodedata unicodedata category3156202 Ref: 146a3156202 Ref: library/unicodedata unicodedata bidirectional3156327 Ref: 146b3156327 Ref: library/unicodedata unicodedata combining3156519 Ref: 146c3156519 Ref: library/unicodedata unicodedata east_asian_width3156706 Ref: 146d3156706 Ref: library/unicodedata unicodedata mirrored3156839 Ref: 146e3156839 Ref: library/unicodedata unicodedata decomposition3157097 Ref: 146f3157097 Ref: library/unicodedata unicodedata normalize3157312 Ref: 11ed3157312 Ref: library/unicodedata unicodedata is_normalized3159174 Ref: 2463159174 Ref: library/unicodedata unicodedata unidata_version3159481 Ref: 14703159481 Ref: library/unicodedata unicodedata ucd_3_2_03159583 Ref: d9c3159583 Ref: unicodedata — Unicode Database-Footnote-13160362 Ref: unicodedata — Unicode Database-Footnote-23160411 Ref: unicodedata — Unicode Database-Footnote-33160457 Ref: unicodedata — Unicode Database-Footnote-43160532 Node: stringprep — Internet String Preparation3160610 Ref: library/stringprep doc3160798 Ref: 14713160798 Ref: library/stringprep module-stringprep3160798 Ref: f73160798 Ref: library/stringprep stringprep-internet-string-preparation3160798 Ref: 14723160798 Ref: library/stringprep stringprep in_table_a13162720 Ref: 14733162720 Ref: library/stringprep stringprep in_table_b13162857 Ref: 14743162857 Ref: library/stringprep stringprep map_table_b23162983 Ref: 14753162983 Ref: library/stringprep stringprep map_table_b33163140 Ref: 14763163140 Ref: library/stringprep stringprep in_table_c113163309 Ref: 14773163309 Ref: library/stringprep stringprep in_table_c123163429 Ref: 14783163429 Ref: library/stringprep stringprep in_table_c11_c123163558 Ref: 14793163558 Ref: library/stringprep stringprep in_table_c213163705 Ref: 147a3163705 Ref: library/stringprep stringprep in_table_c223163832 Ref: 147b3163832 Ref: library/stringprep stringprep in_table_c21_c223163963 Ref: 147c3163963 Ref: library/stringprep stringprep in_table_c33164112 Ref: 147d3164112 Ref: library/stringprep stringprep in_table_c43164218 Ref: 147e3164218 Ref: library/stringprep stringprep in_table_c53164343 Ref: 147f3164343 Ref: library/stringprep stringprep in_table_c63164453 Ref: 14803164453 Ref: library/stringprep stringprep in_table_c73164581 Ref: 14813164581 Ref: library/stringprep stringprep in_table_c83164723 Ref: 14823164723 Ref: library/stringprep stringprep in_table_c93164866 Ref: 14833164866 Ref: library/stringprep stringprep in_table_d13164979 Ref: 14843164979 Ref: library/stringprep stringprep in_table_d23165137 Ref: 14853165137 Ref: stringprep — Internet String Preparation-Footnote-13165319 Ref: stringprep — Internet String Preparation-Footnote-23165388 Ref: stringprep — Internet String Preparation-Footnote-33165437 Node: readline — GNU readline interface3165486 Ref: library/readline doc3165694 Ref: 14863165694 Ref: library/readline module-readline3165694 Ref: de3165694 Ref: library/readline readline-gnu-readline-interface3165694 Ref: 14873165694 Ref: readline — GNU readline interface-Footnote-13167615 Node: Init file3167685 Ref: library/readline init-file3167786 Ref: 14883167786 Ref: library/readline readline parse_and_bind3167896 Ref: 14893167896 Ref: library/readline readline read_init_file3168077 Ref: 148a3168077 Node: Line buffer3168299 Ref: library/readline line-buffer3168421 Ref: 148b3168421 Ref: library/readline readline get_line_buffer3168515 Ref: 148c3168515 Ref: library/readline readline insert_text3168666 Ref: 148d3168666 Ref: library/readline readline redisplay3168876 Ref: 148e3168876 Node: History file3169081 Ref: library/readline history-file3169206 Ref: 148f3169206 Ref: library/readline readline read_history_file3169301 Ref: 14903169301 Ref: library/readline readline write_history_file3169539 Ref: 14913169539 Ref: library/readline readline append_history_file3169796 Ref: 73c3169796 Ref: library/readline readline get_history_length3170203 Ref: 14923170203 Ref: library/readline readline set_history_length3170248 Ref: 14933170248 Node: History list3170611 Ref: library/readline history-list3170738 Ref: 14943170738 Ref: library/readline readline clear_history3170840 Ref: 14953170840 Ref: library/readline readline get_current_history_length3171088 Ref: 14963171088 Ref: library/readline readline get_history_item3171353 Ref: 14973171353 Ref: library/readline readline remove_history_item3171563 Ref: 14983171563 Ref: library/readline readline replace_history_item3171783 Ref: 14993171783 Ref: library/readline readline add_history3172014 Ref: 149a3172014 Ref: library/readline readline set_auto_history3172198 Ref: 5773172198 Node: Startup hooks3172664 Ref: library/readline startup-hooks3172789 Ref: 149b3172789 Ref: library/readline readline set_startup_hook3172834 Ref: 149c3172834 Ref: library/readline readline set_pre_input_hook3173238 Ref: 149d3173238 Node: Completion3173810 Ref: library/readline completion3173930 Ref: 149e3173930 Ref: library/readline readline set_completer3174416 Ref: 149f3174416 Ref: library/readline readline get_completer3175207 Ref: 14a03175207 Ref: library/readline readline get_completion_type3175340 Ref: 14a13175340 Ref: library/readline readline get_begidx3175540 Ref: 14a23175540 Ref: library/readline readline get_endidx3175577 Ref: 14a33175577 Ref: library/readline readline set_completer_delims3175835 Ref: 14a43175835 Ref: library/readline readline get_completer_delims3175888 Ref: 14a53175888 Ref: library/readline readline set_completion_display_matches_hook3176209 Ref: 14a63176209 Node: Example3176798 Ref: library/readline example3176896 Ref: 14a73176896 Ref: library/readline readline-example3176896 Ref: 14a83176896 Node: rlcompleter — Completion function for GNU readline3179536 Ref: library/rlcompleter doc3179693 Ref: 14aa3179693 Ref: library/rlcompleter module-rlcompleter3179693 Ref: e13179693 Ref: library/rlcompleter rlcompleter-completion-function-for-gnu-readline3179693 Ref: 14ab3179693 Ref: rlcompleter — Completion function for GNU readline-Footnote-13181158 Node: Completer Objects3181228 Ref: library/rlcompleter completer-objects3181334 Ref: 14ac3181334 Ref: library/rlcompleter id13181334 Ref: 14ad3181334 Ref: library/rlcompleter rlcompleter Completer complete3181433 Ref: 14ae3181433 Node: Binary Data Services3182189 Ref: library/binary doc3182325 Ref: 14af3182325 Ref: library/binary binary-data-services3182325 Ref: 14b03182325 Ref: library/binary binaryservices3182325 Ref: 13c73182325 Node: struct — Interpret bytes as packed binary data3183091 Ref: library/struct doc3183247 Ref: 14b13183247 Ref: library/struct module-struct3183247 Ref: f83183247 Ref: library/struct struct-interpret-bytes-as-packed-binary-data3183247 Ref: 14b23183247 Ref: struct — Interpret bytes as packed binary data-Footnote-13185054 Node: Functions and Exceptions3185119 Ref: library/struct functions-and-exceptions3185251 Ref: 14b63185251 Ref: library/struct struct error3185377 Ref: cb43185377 Ref: library/struct struct pack3185503 Ref: c0b3185503 Ref: library/struct struct pack_into3185745 Ref: 14b73185745 Ref: library/struct struct unpack3186044 Ref: f983186044 Ref: library/struct struct unpack_from3186411 Ref: 14b93186411 Ref: library/struct struct iter_unpack3186804 Ref: 8d83186804 Ref: library/struct struct calcsize3187324 Ref: 14b83187324 Node: Format Strings3187523 Ref: library/struct format-strings3187674 Ref: 14ba3187674 Ref: library/struct struct-format-strings3187674 Ref: 14b33187674 Node: Byte Order Size and Alignment3188163 Ref: library/struct byte-order-size-and-alignment3188269 Ref: 14bc3188269 Ref: library/struct struct-alignment3188269 Ref: 14b43188269 Ref: Byte Order Size and Alignment-Footnote-13191426 Node: Format Characters3191470 Ref: library/struct format-characters3191596 Ref: 14bb3191596 Ref: library/struct id13191596 Ref: 14be3191596 Ref: Format Characters-Footnote-13202582 Ref: Format Characters-Footnote-23202654 Node: Examples<2>3202730 Ref: library/struct examples3202818 Ref: 14bf3202818 Ref: library/struct struct-examples3202818 Ref: 14bd3202818 Node: Classes<2>3204531 Ref: library/struct classes3204649 Ref: 14c03204649 Ref: library/struct struct-objects3204649 Ref: 14c13204649 Ref: library/struct struct Struct3204745 Ref: 14b53204745 Ref: library/struct struct Struct pack3205487 Ref: 14c23205487 Ref: library/struct struct Struct pack_into3205668 Ref: 14c43205668 Ref: library/struct struct Struct unpack3205826 Ref: 14c53205826 Ref: library/struct struct Struct unpack_from3206025 Ref: 14c63206025 Ref: library/struct struct Struct iter_unpack3206283 Ref: 8d93206283 Ref: library/struct struct Struct format3206534 Ref: 4923206534 Ref: library/struct struct Struct size3206749 Ref: 14c33206749 Node: codecs — Codec registry and base classes3206950 Ref: library/codecs doc3207106 Ref: 14c73207106 Ref: library/codecs codecs-codec-registry-and-base-classes3207106 Ref: 14c83207106 Ref: library/codecs ietf-rfc-17003207106 Ref: 14c93207106 Ref: library/codecs module-codecs3207106 Ref: 1c3207106 Ref: library/codecs codecs encode3207967 Ref: 8023207967 Ref: library/codecs codecs decode3208462 Ref: 8033208462 Ref: library/codecs codecs lookup3209022 Ref: 13ac3209022 Ref: library/codecs codecs CodecInfo3209520 Ref: 14cb3209520 Ref: library/codecs codecs CodecInfo name3209816 Ref: 14cc3209816 Ref: library/codecs codecs CodecInfo encode3209879 Ref: 14cd3209879 Ref: library/codecs codecs CodecInfo decode3209906 Ref: 14ce3209906 Ref: library/codecs codecs CodecInfo incrementalencoder3210284 Ref: 14d23210284 Ref: library/codecs codecs CodecInfo incrementaldecoder3210323 Ref: 14d33210323 Ref: library/codecs codecs CodecInfo streamwriter3210662 Ref: 14d63210662 Ref: library/codecs codecs CodecInfo streamreader3210695 Ref: 14d73210695 Ref: library/codecs codecs getencoder3211149 Ref: 14da3211149 Ref: library/codecs codecs getdecoder3211361 Ref: 14db3211361 Ref: library/codecs codecs getincrementalencoder3211573 Ref: 14dc3211573 Ref: library/codecs codecs getincrementaldecoder3211879 Ref: 14dd3211879 Ref: library/codecs codecs getreader3212185 Ref: 14de3212185 Ref: library/codecs codecs getwriter3212431 Ref: 14df3212431 Ref: library/codecs codecs register3212760 Ref: 14e03212760 Ref: library/codecs codecs open3213564 Ref: ffe3213564 Ref: library/codecs codecs EncodedFile3214817 Ref: 14e23214817 Ref: library/codecs codecs iterencode3215674 Ref: 14e43215674 Ref: library/codecs codecs iterdecode3216204 Ref: 14e53216204 Ref: library/codecs codecs BOM3216926 Ref: 14e63216926 Ref: library/codecs codecs BOM_BE3216947 Ref: 14e73216947 Ref: library/codecs codecs BOM_LE3216971 Ref: 14e83216971 Ref: library/codecs codecs BOM_UTF83216995 Ref: 14e93216995 Ref: library/codecs codecs BOM_UTF163217021 Ref: 14ea3217021 Ref: library/codecs codecs BOM_UTF16_BE3217048 Ref: 14eb3217048 Ref: library/codecs codecs BOM_UTF16_LE3217078 Ref: 14ec3217078 Ref: library/codecs codecs BOM_UTF323217108 Ref: 14ed3217108 Ref: library/codecs codecs BOM_UTF32_BE3217135 Ref: 14ee3217135 Ref: library/codecs codecs BOM_UTF32_LE3217165 Ref: 14ef3217165 Ref: codecs — Codec registry and base classes-Footnote-13218312 Node: Codec Base Classes3218377 Ref: library/codecs codec-base-classes3218504 Ref: 14ca3218504 Ref: library/codecs id13218504 Ref: 14f03218504 Ref: library/codecs surrogateescape3219097 Ref: 14f13219097 Node: Error Handlers3219234 Ref: library/codecs error-handlers3219343 Ref: ffd3219343 Ref: library/codecs id23219343 Ref: 14f23219343 Ref: library/codecs codecs register_error3223427 Ref: df53223427 Ref: library/codecs codecs lookup_error3224968 Ref: df63224968 Ref: library/codecs codecs strict_errors3225263 Ref: 14f33225263 Ref: library/codecs codecs replace_errors3225434 Ref: 14f53225434 Ref: library/codecs codecs ignore_errors3225738 Ref: 14f43225738 Ref: library/codecs codecs xmlcharrefreplace_errors3225931 Ref: 14f63225931 Ref: library/codecs codecs backslashreplace_errors3226197 Ref: 14f73226197 Ref: library/codecs codecs namereplace_errors3226427 Ref: 14f83226427 Ref: Error Handlers-Footnote-13226736 Node: Stateless Encoding and Decoding3226785 Ref: library/codecs codec-objects3226936 Ref: 14d13226936 Ref: library/codecs stateless-encoding-and-decoding3226936 Ref: 14f93226936 Ref: library/codecs codecs Codec encode3227147 Ref: 14cf3227147 Ref: library/codecs codecs Codec decode3227889 Ref: 14d03227889 Node: Incremental Encoding and Decoding3228816 Ref: library/codecs incremental-encoding-and-decoding3228981 Ref: 14fa3228981 Node: IncrementalEncoder Objects3229821 Ref: library/codecs incremental-encoder-objects3229952 Ref: 14fd3229952 Ref: library/codecs incrementalencoder-objects3229952 Ref: 14fe3229952 Ref: library/codecs codecs IncrementalEncoder3230251 Ref: 14d43230251 Ref: library/codecs codecs IncrementalEncoder encode3231035 Ref: 14fb3231035 Ref: library/codecs codecs IncrementalEncoder reset3231328 Ref: 14ff3231328 Ref: library/codecs codecs IncrementalEncoder getstate3231597 Ref: 15003231597 Ref: library/codecs codecs IncrementalEncoder setstate3232010 Ref: 15013232010 Node: IncrementalDecoder Objects3232177 Ref: library/codecs incremental-decoder-objects3232308 Ref: 15023232308 Ref: library/codecs incrementaldecoder-objects3232308 Ref: 15033232308 Ref: library/codecs codecs IncrementalDecoder3232607 Ref: 14d53232607 Ref: library/codecs codecs IncrementalDecoder decode3233391 Ref: 14fc3233391 Ref: library/codecs codecs IncrementalDecoder reset3234020 Ref: 15043234020 Ref: library/codecs codecs IncrementalDecoder getstate3234098 Ref: 15053234098 Ref: library/codecs codecs IncrementalDecoder setstate3235045 Ref: 15063235045 Node: Stream Encoding and Decoding3235211 Ref: library/codecs stream-encoding-and-decoding3235336 Ref: 15073235336 Node: StreamWriter Objects3235763 Ref: library/codecs stream-writer-objects3235877 Ref: 15083235877 Ref: library/codecs streamwriter-objects3235877 Ref: 15093235877 Ref: library/codecs codecs StreamWriter3236132 Ref: 14d83236132 Ref: library/codecs codecs StreamWriter write3237088 Ref: 150a3237088 Ref: library/codecs codecs StreamWriter writelines3237186 Ref: 150b3237186 Ref: library/codecs codecs StreamWriter reset3237426 Ref: 150c3237426 Node: StreamReader Objects3237898 Ref: library/codecs stream-reader-objects3238047 Ref: 150d3238047 Ref: library/codecs streamreader-objects3238047 Ref: 150e3238047 Ref: library/codecs codecs StreamReader3238302 Ref: 14d93238302 Ref: library/codecs codecs StreamReader read3239371 Ref: 150f3239371 Ref: library/codecs codecs StreamReader readline3240623 Ref: 15103240623 Ref: library/codecs codecs StreamReader readlines3240968 Ref: 15113240968 Ref: library/codecs codecs StreamReader reset3241413 Ref: 15123241413 Node: StreamReaderWriter Objects3241807 Ref: library/codecs stream-reader-writer3241957 Ref: 15133241957 Ref: library/codecs streamreaderwriter-objects3241957 Ref: 15143241957 Ref: library/codecs codecs StreamReaderWriter3242293 Ref: 14e13242293 Node: StreamRecoder Objects3242948 Ref: library/codecs stream-recoder-objects3243069 Ref: 15153243069 Ref: library/codecs streamrecoder-objects3243069 Ref: 15163243069 Ref: library/codecs codecs StreamRecoder3243420 Ref: 14e33243420 Node: Encodings and Unicode3244551 Ref: library/codecs encodings-and-unicode3244705 Ref: 15173244705 Ref: library/codecs encodings-overview3244705 Ref: 15183244705 Ref: Encodings and Unicode-Footnote-13251404 Node: Standard Encodings3251453 Ref: library/codecs id33251614 Ref: 15193251614 Ref: library/codecs standard-encodings3251614 Ref: 68f3251614 Node: Python Specific Encodings3273638 Ref: library/codecs python-specific-encodings3273843 Ref: 151a3273843 Node: Text Encodings3274431 Ref: library/codecs text-encodings3274533 Ref: 151b3274533 Ref: Text Encodings-Footnote-13277905 Ref: Text Encodings-Footnote-23277954 Node: Binary Transforms3278003 Ref: library/codecs binary-transforms3278129 Ref: 8043278129 Ref: library/codecs id43278129 Ref: 151c3278129 Ref: Binary Transforms-Footnote-13281934 Node: Text Transforms3282079 Ref: library/codecs id63282182 Ref: 15253282182 Ref: library/codecs text-transforms3282182 Ref: 8053282182 Node: encodings idna — Internationalized Domain Names in Applications3282926 Ref: library/codecs encodings-idna-internationalized-domain-names-in-applications3283153 Ref: 15263283153 Ref: library/codecs module-encodings idna3283153 Ref: 773283153 Ref: library/codecs encodings idna nameprep3285662 Ref: 15273285662 Ref: library/codecs encodings idna ToASCII3285850 Ref: 15283285850 Ref: library/codecs encodings idna ToUnicode3286010 Ref: 15293286010 Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-13286157 Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-23286206 Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-33286255 Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-43286316 Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-53286365 Node: encodings mbcs — Windows ANSI codepage3286414 Ref: library/codecs encodings-mbcs-windows-ansi-codepage3286670 Ref: 152a3286670 Ref: library/codecs module-encodings mbcs3286670 Ref: 783286670 Node: encodings utf_8_sig — UTF-8 codec with BOM signature3287067 Ref: library/codecs encodings-utf-8-sig-utf-8-codec-with-bom-signature3287249 Ref: 152b3287249 Ref: library/codecs module-encodings utf_8_sig3287249 Ref: 793287249 Node: Data Types3287694 Ref: library/datatypes doc3287838 Ref: 152c3287838 Ref: library/datatypes data-types3287838 Ref: 152d3287838 Ref: library/datatypes datatypes3287838 Ref: 152e3287838 Node: datetime — Basic date and time types3289108 Ref: library/datetime doc3289249 Ref: 152f3289249 Ref: library/datetime datetime-basic-date-and-time-types3289249 Ref: 15303289249 Ref: library/datetime module-datetime3289249 Ref: 313289249 Ref: datetime — Basic date and time types-Footnote-13290223 Ref: datetime — Basic date and time types-Footnote-23290290 Node: Aware and Naive Objects3290341 Ref: library/datetime aware-and-naive-objects3290457 Ref: 15313290457 Ref: library/datetime datetime-naive-aware3290457 Ref: 15323290457 Ref: Aware and Naive Objects-Footnote-13292383 Node: Constants3292444 Ref: library/datetime constants3292584 Ref: 15333292584 Ref: library/datetime datetime MINYEAR3292686 Ref: 15343292686 Ref: library/datetime datetime MAXYEAR3292846 Ref: 15353292846 Node: Available Types3293008 Ref: library/datetime available-types3293142 Ref: 15363293142 Node: Common Properties3294924 Ref: library/datetime common-properties3295044 Ref: 15473295044 Node: Determining if an Object is Aware or Naive3295454 Ref: library/datetime determining-if-an-object-is-aware-or-naive3295574 Ref: 15483295574 Node: timedelta Objects3296309 Ref: library/datetime datetime-timedelta3296446 Ref: 15493296446 Ref: library/datetime timedelta-objects3296446 Ref: 154a3296446 Ref: library/datetime datetime timedelta3296605 Ref: 1953296605 Ref: library/datetime datetime timedelta min3298857 Ref: 154b3298857 Ref: library/datetime datetime timedelta max3298975 Ref: 154c3298975 Ref: library/datetime datetime timedelta resolution3299157 Ref: 154d3299157 Ref: library/datetime datetime timedelta total_seconds3306560 Ref: c9c3306560 Node: Examples of usage timedelta3307082 Ref: library/datetime examples-of-usage-timedelta3307163 Ref: 154e3307163 Node: date Objects3308104 Ref: library/datetime date-objects3308242 Ref: 154f3308242 Ref: library/datetime datetime-date3308242 Ref: 15503308242 Ref: library/datetime datetime date3308564 Ref: 1933308564 Ref: library/datetime datetime date today3308983 Ref: 15513308983 Ref: library/datetime datetime date fromtimestamp3309126 Ref: 15523309126 Ref: library/datetime datetime date fromordinal3310064 Ref: 15533310064 Ref: library/datetime datetime date fromisoformat3310397 Ref: 15543310397 Ref: library/datetime datetime date fromisocalendar3310825 Ref: 1c43310825 Ref: library/datetime datetime date min3311117 Ref: 15573311117 Ref: library/datetime datetime date max3311208 Ref: 15583311208 Ref: library/datetime datetime date resolution3311299 Ref: 15593311299 Ref: library/datetime datetime date year3311466 Ref: 15373311466 Ref: library/datetime datetime date month3311563 Ref: 15383311563 Ref: library/datetime datetime date day3311624 Ref: 15393311624 Ref: library/datetime datetime date replace3314114 Ref: 155a3314114 Ref: library/datetime datetime date timetuple3314499 Ref: 155b3314499 Ref: library/datetime datetime date toordinal3314994 Ref: 155d3314994 Ref: library/datetime datetime date weekday3315216 Ref: 155e3315216 Ref: library/datetime datetime date isoweekday3315441 Ref: 155f3315441 Ref: library/datetime datetime date isocalendar3315701 Ref: 15563315701 Ref: library/datetime datetime date isoformat3316550 Ref: 15553316550 Ref: library/datetime datetime date __str__3316839 Ref: 15603316839 Ref: library/datetime datetime date ctime3316941 Ref: 15613316941 Ref: library/datetime datetime date strftime3317415 Ref: 5383317415 Ref: library/datetime datetime date __format__3317723 Ref: 15643317723 Ref: date Objects-Footnote-13318181 Ref: date Objects-Footnote-23318494 Node: Examples of Usage date3318672 Ref: library/datetime examples-of-usage-date3318743 Ref: 15653318743 Node: datetime Objects3320635 Ref: library/datetime datetime-datetime3320768 Ref: 15663320768 Ref: library/datetime datetime-objects3320768 Ref: 15673320768 Ref: library/datetime datetime datetime3321217 Ref: 1943321217 Ref: library/datetime datetime datetime today3322080 Ref: 15683322080 Ref: library/datetime datetime datetime now3322438 Ref: 15693322438 Ref: library/datetime datetime datetime utcnow3323119 Ref: 156b3323119 Ref: library/datetime datetime datetime fromtimestamp3323862 Ref: 156a3323862 Ref: library/datetime datetime datetime utcfromtimestamp3325581 Ref: 156c3325581 Ref: library/datetime datetime datetime fromordinal3327253 Ref: 156d3327253 Ref: library/datetime datetime datetime combine3327658 Ref: 5393327658 Ref: library/datetime datetime datetime fromisoformat3328447 Ref: 37e3328447 Ref: library/datetime datetime datetime fromisocalendar3329971 Ref: 1c53329971 Ref: library/datetime datetime datetime strptime3330350 Ref: 156f3330350 Ref: library/datetime datetime datetime min3330915 Ref: 15703330915 Ref: library/datetime datetime datetime max3331047 Ref: 15713331047 Ref: library/datetime datetime datetime resolution3331199 Ref: 15723331199 Ref: library/datetime datetime datetime year3331394 Ref: 153f3331394 Ref: library/datetime datetime datetime month3331495 Ref: 15403331495 Ref: library/datetime datetime datetime day3331560 Ref: 15413331560 Ref: library/datetime datetime datetime hour3331671 Ref: 15423331671 Ref: library/datetime datetime datetime minute3331727 Ref: 15433331727 Ref: library/datetime datetime datetime second3331785 Ref: 15443331785 Ref: library/datetime datetime datetime microsecond3331843 Ref: 15453331843 Ref: library/datetime datetime datetime tzinfo3331911 Ref: 15463331911 Ref: library/datetime datetime datetime fold3332072 Ref: 4f43332072 Ref: library/datetime datetime datetime date3336703 Ref: 15733336703 Ref: library/datetime datetime datetime time3336801 Ref: 15743336801 Ref: library/datetime datetime datetime timetz3337108 Ref: 15753337108 Ref: library/datetime datetime datetime replace3337398 Ref: 15763337398 Ref: library/datetime datetime datetime astimezone3337980 Ref: 1963337980 Ref: library/datetime datetime datetime utcoffset3340312 Ref: 15773340312 Ref: library/datetime datetime datetime dst3340706 Ref: 15783340706 Ref: library/datetime datetime datetime tzname3341088 Ref: 157a3341088 Ref: library/datetime datetime datetime timetuple3341321 Ref: 157b3341321 Ref: library/datetime datetime datetime utctimetuple3342175 Ref: 157c3342175 Ref: library/datetime datetime datetime toordinal3343302 Ref: 157d3343302 Ref: library/datetime datetime datetime timestamp3343444 Ref: 9e23343444 Ref: library/datetime datetime datetime weekday3344952 Ref: 157e3344952 Ref: library/datetime datetime datetime isoweekday3345156 Ref: 157f3345156 Ref: library/datetime datetime datetime isocalendar3345390 Ref: 156e3345390 Ref: library/datetime datetime datetime isoformat3345544 Ref: 37f3345544 Ref: library/datetime datetime datetime __str__3348528 Ref: 15803348528 Ref: library/datetime datetime datetime ctime3348667 Ref: 15813348667 Ref: library/datetime datetime datetime strftime3349300 Ref: 5373349300 Ref: library/datetime datetime datetime __format__3349544 Ref: 15823349544 Ref: datetime Objects-Footnote-13350022 Node: Examples of Usage datetime3350110 Ref: library/datetime examples-of-usage-datetime3350189 Ref: 15833350189 Node: time Objects3354517 Ref: library/datetime datetime-time3354652 Ref: 15843354652 Ref: library/datetime time-objects3354652 Ref: 15853354652 Ref: library/datetime datetime time3354860 Ref: 4f33354860 Ref: library/datetime datetime time min3355525 Ref: 15863355525 Ref: library/datetime datetime time max3355624 Ref: 15873355624 Ref: library/datetime datetime time resolution3355734 Ref: 15883355734 Ref: library/datetime datetime time hour3356002 Ref: 153a3356002 Ref: library/datetime datetime time minute3356054 Ref: 153b3356054 Ref: library/datetime datetime time second3356108 Ref: 153c3356108 Ref: library/datetime datetime time microsecond3356162 Ref: 153d3356162 Ref: library/datetime datetime time tzinfo3356226 Ref: 153e3356226 Ref: library/datetime datetime time fold3356377 Ref: 15893356377 Ref: library/datetime datetime time fromisoformat3358352 Ref: 158a3358352 Ref: library/datetime datetime time replace3359262 Ref: 158c3359262 Ref: library/datetime datetime time isoformat3359796 Ref: 158b3359796 Ref: library/datetime datetime time __str__3361807 Ref: 158e3361807 Ref: library/datetime datetime time strftime3361909 Ref: 158f3361909 Ref: library/datetime datetime time __format__3362140 Ref: 15903362140 Ref: library/datetime datetime time utcoffset3362502 Ref: 158d3362502 Ref: library/datetime datetime time dst3362892 Ref: 15913362892 Ref: library/datetime datetime time tzname3363271 Ref: 15923363271 Ref: time Objects-Footnote-13363600 Node: Examples of Usage time3363643 Ref: library/datetime examples-of-usage-time3363714 Ref: 15933363714 Node: tzinfo Objects3364596 Ref: library/datetime datetime-tzinfo3364731 Ref: 15943364731 Ref: library/datetime tzinfo-objects3364731 Ref: 15953364731 Ref: library/datetime datetime tzinfo3364788 Ref: 3803364788 Ref: library/datetime datetime tzinfo utcoffset3366430 Ref: 15963366430 Ref: library/datetime datetime tzinfo dst3367660 Ref: 15973367660 Ref: library/datetime datetime tzinfo tzname3370242 Ref: 15983370242 Ref: library/datetime datetime tzinfo fromutc3372381 Ref: 15793372381 Ref: tzinfo Objects-Footnote-13384882 Ref: tzinfo Objects-Footnote-23384940 Node: timezone Objects3384980 Ref: library/datetime datetime-timezone3385133 Ref: 159a3385133 Ref: library/datetime timezone-objects3385133 Ref: 159b3385133 Ref: library/datetime datetime timezone3385553 Ref: a013385553 Ref: library/datetime datetime timezone utcoffset3386181 Ref: 159c3386181 Ref: library/datetime datetime timezone tzname3386571 Ref: 159d3386571 Ref: library/datetime datetime timezone dst3387253 Ref: 159e3387253 Ref: library/datetime datetime timezone fromutc3387317 Ref: 159f3387317 Ref: library/datetime datetime timezone utc3387512 Ref: 15993387512 Node: strftime and strptime Behavior3387595 Ref: library/datetime strftime-and-strptime-behavior3387725 Ref: 15a03387725 Ref: library/datetime strftime-strptime-behavior3387725 Ref: 15633387725 Node: strftime and strptime Format Codes3389911 Ref: library/datetime strftime-and-strptime-format-codes3390037 Ref: 15a13390037 Node: Technical Detail3399998 Ref: library/datetime technical-detail3400124 Ref: 15a23400124 Ref: Technical Detail-Footnote-13405786 Node: calendar — General calendar-related functions3405896 Ref: library/calendar doc3406081 Ref: 15a43406081 Ref: library/calendar calendar-general-calendar-related-functions3406081 Ref: 15a53406081 Ref: library/calendar module-calendar3406081 Ref: 153406081 Ref: library/calendar calendar Calendar3407284 Ref: 15a73407284 Ref: library/calendar calendar Calendar iterweekdays3407791 Ref: 15a83407791 Ref: library/calendar calendar Calendar itermonthdates3408040 Ref: 4a63408040 Ref: library/calendar calendar Calendar itermonthdays3408412 Ref: 15aa3408412 Ref: library/calendar calendar Calendar itermonthdays23408797 Ref: 15ab3408797 Ref: library/calendar calendar Calendar itermonthdays33409147 Ref: 4a73409147 Ref: library/calendar calendar Calendar itermonthdays43409527 Ref: 4a83409527 Ref: library/calendar calendar Calendar monthdatescalendar3409927 Ref: 15ac3409927 Ref: library/calendar calendar Calendar monthdays2calendar3410147 Ref: 15ad3410147 Ref: library/calendar calendar Calendar monthdayscalendar3410375 Ref: 15ae3410375 Ref: library/calendar calendar Calendar yeardatescalendar3410562 Ref: 15af3410562 Ref: library/calendar calendar Calendar yeardays2calendar3410956 Ref: 15b03410956 Ref: library/calendar calendar Calendar yeardayscalendar3411272 Ref: 15b13411272 Ref: library/calendar calendar TextCalendar3411557 Ref: 15b23411557 Ref: library/calendar calendar TextCalendar formatmonth3411741 Ref: 15b33411741 Ref: library/calendar calendar TextCalendar prmonth3412190 Ref: 15b43412190 Ref: library/calendar calendar TextCalendar formatyear3412336 Ref: 15b53412336 Ref: library/calendar calendar TextCalendar pryear3412873 Ref: 15b63412873 Ref: library/calendar calendar HTMLCalendar3413028 Ref: 36f3413028 Ref: library/calendar calendar HTMLCalendar formatmonth3413199 Ref: 15b73413199 Ref: library/calendar calendar HTMLCalendar formatyear3413449 Ref: 15b83413449 Ref: library/calendar calendar HTMLCalendar formatyearpage3413630 Ref: 15b93413630 Ref: library/calendar calendar HTMLCalendar cssclasses3414270 Ref: 15ba3414270 Ref: library/calendar calendar HTMLCalendar cssclass_noday3414684 Ref: 15bb3414684 Ref: library/calendar calendar HTMLCalendar cssclasses_weekday_head3414843 Ref: 15bc3414843 Ref: library/calendar calendar HTMLCalendar cssclass_month_head3415056 Ref: 15bd3415056 Ref: library/calendar calendar HTMLCalendar cssclass_month3415250 Ref: 15be3415250 Ref: library/calendar calendar HTMLCalendar cssclass_year3415457 Ref: 15bf3415457 Ref: library/calendar calendar HTMLCalendar cssclass_year_head3415670 Ref: 15c03415670 Ref: library/calendar calendar LocaleTextCalendar3416577 Ref: 15c13416577 Ref: library/calendar calendar LocaleHTMLCalendar3416941 Ref: 15c23416941 Ref: library/calendar calendar setfirstweekday3417629 Ref: 15a63417629 Ref: library/calendar calendar firstweekday3418055 Ref: 15a93418055 Ref: library/calendar calendar isleap3418165 Ref: 15c33418165 Ref: library/calendar calendar leapdays3418293 Ref: 15c43418293 Ref: library/calendar calendar weekday3418518 Ref: 15c53418518 Ref: library/calendar calendar weekheader3418717 Ref: 15c63418717 Ref: library/calendar calendar monthrange3418877 Ref: 15c73418877 Ref: library/calendar calendar monthcalendar3419046 Ref: 15c83419046 Ref: library/calendar calendar prmonth3419327 Ref: 15c93419327 Ref: library/calendar calendar month3419459 Ref: 15ca3419459 Ref: library/calendar calendar prcal3419652 Ref: 15cb3419652 Ref: library/calendar calendar calendar3419796 Ref: 15cc3419796 Ref: library/calendar calendar timegm3420011 Ref: 15cd3420011 Ref: library/calendar calendar day_name3420487 Ref: 15ce3420487 Ref: library/calendar calendar day_abbr3420596 Ref: 15cf3420596 Ref: library/calendar calendar month_name3420717 Ref: 15d03420717 Ref: library/calendar calendar month_abbr3420975 Ref: 15d13420975 Ref: calendar — General calendar-related functions-Footnote-13421508 Node: collections — Container datatypes3421575 Ref: library/collections doc3421778 Ref: 15d23421778 Ref: library/collections collections-container-datatypes3421778 Ref: 15d33421778 Ref: library/collections module-collections3421778 Ref: 1e3421778 Ref: collections — Container datatypes-Footnote-13424009 Node: ChainMap objects3424089 Ref: library/collections chainmap-objects3424201 Ref: 15d73424201 Ref: library/collections collections ChainMap3424588 Ref: 4a93424588 Ref: library/collections collections ChainMap maps3425621 Ref: 15d83425621 Ref: library/collections collections ChainMap new_child3425924 Ref: 8293425924 Ref: library/collections collections ChainMap parents3426562 Ref: 15d93426562 Ref: ChainMap objects-Footnote-13428415 Ref: ChainMap objects-Footnote-23428510 Ref: ChainMap objects-Footnote-33428557 Ref: ChainMap objects-Footnote-43428636 Ref: ChainMap objects-Footnote-53428689 Node: ChainMap Examples and Recipes3428742 Ref: library/collections chainmap-examples-and-recipes3428824 Ref: 15da3428824 Node: Counter objects3431938 Ref: library/collections counter-objects3432072 Ref: 15db3432072 Ref: library/collections collections Counter3432777 Ref: 9da3432777 Ref: library/collections collections Counter elements3434747 Ref: c9a3434747 Ref: library/collections collections Counter most_common3435170 Ref: c993435170 Ref: library/collections collections Counter subtract3435630 Ref: b5a3435630 Ref: library/collections collections Counter fromkeys3436321 Ref: 15dc3436321 Ref: library/collections collections Counter update3436450 Ref: 15dd3436450 Ref: Counter objects-Footnote-13440836 Ref: Counter objects-Footnote-23440915 Ref: Counter objects-Footnote-33440962 Node: deque objects3441055 Ref: library/collections deque-objects3441192 Ref: 15de3441192 Ref: library/collections collections deque3441245 Ref: 5313441245 Ref: library/collections collections deque append3442688 Ref: 15df3442688 Ref: library/collections collections deque appendleft3442768 Ref: 15e03442768 Ref: library/collections collections deque clear3442851 Ref: 15e13442851 Ref: library/collections collections deque copy3442950 Ref: 6ab3442950 Ref: library/collections collections deque count3443054 Ref: b5c3443054 Ref: library/collections collections deque extend3443173 Ref: 15e23443173 Ref: library/collections collections deque extendleft3443315 Ref: 15e33443315 Ref: library/collections collections deque index3443562 Ref: 6a93443562 Ref: library/collections collections deque insert3443834 Ref: 6aa3443834 Ref: library/collections collections deque pop3444079 Ref: 15e43444079 Ref: library/collections collections deque popleft3444249 Ref: 15e53444249 Ref: library/collections collections deque remove3444422 Ref: 15e63444422 Ref: library/collections collections deque reverse3444563 Ref: b5d3444563 Ref: library/collections collections deque rotate3444715 Ref: 15e73444715 Ref: library/collections collections deque maxlen3445124 Ref: c9b3445124 Node: deque Recipes3447775 Ref: library/collections deque-recipes3447838 Ref: 15e83447838 Ref: deque Recipes-Footnote-13450301 Node: defaultdict objects3450362 Ref: library/collections defaultdict-objects3450540 Ref: 15e93450540 Ref: library/collections collections defaultdict3450605 Ref: b3a3450605 Ref: library/collections collections defaultdict __missing__3451386 Ref: 15eb3451386 Ref: library/collections collections defaultdict default_factory3452575 Ref: 15ea3452575 Node: defaultdict Examples3452846 Ref: library/collections defaultdict-examples3452922 Ref: 15ec3452922 Node: namedtuple Factory Function for Tuples with Named Fields3455585 Ref: library/collections namedtuple-factory-function-for-tuples-with-named-fields3455769 Ref: 15ed3455769 Ref: library/collections collections namedtuple3456150 Ref: 1b73456150 Ref: library/collections collections somenamedtuple _make3460059 Ref: 15ee3460059 Ref: library/collections collections somenamedtuple _asdict3460290 Ref: 1b63460290 Ref: library/collections collections somenamedtuple _replace3460976 Ref: 15ef3460976 Ref: library/collections collections somenamedtuple _fields3461376 Ref: 15f03461376 Ref: library/collections collections somenamedtuple _field_defaults3461872 Ref: 15f13461872 Node: OrderedDict objects3464639 Ref: library/collections ordereddict-objects3464820 Ref: 15f23464820 Ref: library/collections collections OrderedDict3466243 Ref: 1b93466243 Ref: library/collections collections OrderedDict popitem3466439 Ref: c843466439 Ref: library/collections collections OrderedDict move_to_end3466697 Ref: b5b3466697 Ref: OrderedDict objects-Footnote-13468241 Ref: OrderedDict objects-Footnote-23468326 Node: OrderedDict Examples and Recipes3468375 Ref: library/collections ordereddict-examples-and-recipes3468463 Ref: 15f53468463 Node: UserDict objects3469803 Ref: library/collections userdict-objects3469944 Ref: 15f63469944 Ref: library/collections collections UserDict3470310 Ref: 15d43470310 Ref: library/collections collections UserDict data3470900 Ref: 15f73470900 Node: UserList objects3471028 Ref: library/collections userlist-objects3471168 Ref: 15f83471168 Ref: library/collections collections UserList3471683 Ref: 15d53471683 Ref: library/collections collections UserList data3472288 Ref: 15f93472288 Node: UserString objects3473082 Ref: library/collections userstring-objects3473197 Ref: 15fa3473197 Ref: library/collections collections UserString3473559 Ref: 6ad3473559 Ref: library/collections collections UserString data3474153 Ref: 15fb3474153 Node: collections abc — Abstract Base Classes for Containers3474453 Ref: library/collections abc doc3474639 Ref: 15fc3474639 Ref: library/collections abc collections-abc-abstract-base-classes-for-containers3474639 Ref: 15fd3474639 Ref: library/collections abc module-collections abc3474639 Ref: 1f3474639 Ref: collections abc — Abstract Base Classes for Containers-Footnote-13475251 Node: Collections Abstract Base Classes3475327 Ref: library/collections abc collections-abstract-base-classes3475453 Ref: 15d63475453 Ref: library/collections abc id13475453 Ref: 15fe3475453 Ref: library/collections abc collections abc Container3484413 Ref: 15ff3484413 Ref: library/collections abc collections abc Hashable3484525 Ref: 16003484525 Ref: library/collections abc collections abc Sized3484632 Ref: 16033484632 Ref: library/collections abc collections abc Callable3484735 Ref: 16043484735 Ref: library/collections abc collections abc Iterable3484843 Ref: 16013484843 Ref: library/collections abc collections abc Collection3485323 Ref: 52d3485323 Ref: library/collections abc collections abc Iterator3485436 Ref: 16023485436 Ref: library/collections abc collections abc Reversible3485632 Ref: 52e3485632 Ref: library/collections abc collections abc Generator3485790 Ref: 6b53485790 Ref: library/collections abc collections abc Sequence3486108 Ref: 12db3486108 Ref: library/collections abc collections abc MutableSequence3486144 Ref: 6ac3486144 Ref: library/collections abc collections abc ByteString3486187 Ref: 16053486187 Ref: library/collections abc collections abc Set3486922 Ref: 13853486922 Ref: library/collections abc collections abc MutableSet3486953 Ref: 16063486953 Ref: library/collections abc collections abc Mapping3487035 Ref: 15f33487035 Ref: library/collections abc collections abc MutableMapping3487070 Ref: 9ef3487070 Ref: library/collections abc collections abc MappingView3487171 Ref: 16073487171 Ref: library/collections abc collections abc ItemsView3487210 Ref: 16083487210 Ref: library/collections abc collections abc KeysView3487247 Ref: 16093487247 Ref: library/collections abc collections abc ValuesView3487283 Ref: 160a3487283 Ref: library/collections abc collections abc Awaitable3487389 Ref: 6b63487389 Ref: library/collections abc collections abc Coroutine3488165 Ref: 6b73488165 Ref: library/collections abc collections abc AsyncIterable3489059 Ref: 6b93489059 Ref: library/collections abc collections abc AsyncIterator3489253 Ref: 6b83489253 Ref: library/collections abc collections abc AsyncGenerator3489467 Ref: 5303489467 Ref: Collections Abstract Base Classes-Footnote-13492508 Ref: Collections Abstract Base Classes-Footnote-23492557 Ref: Collections Abstract Base Classes-Footnote-33492606 Ref: Collections Abstract Base Classes-Footnote-43492655 Ref: Collections Abstract Base Classes-Footnote-53492708 Node: heapq — Heap queue algorithm3492757 Ref: library/heapq doc3492944 Ref: 160b3492944 Ref: library/heapq heapq-heap-queue-algorithm3492944 Ref: 160c3492944 Ref: library/heapq module-heapq3492944 Ref: 8e3492944 Ref: library/heapq heapq heappush3494499 Ref: 160e3494499 Ref: library/heapq heapq heappop3494624 Ref: 160f3494624 Ref: library/heapq heapq heappushpop3494888 Ref: 16103494888 Ref: library/heapq heapq heapify3495161 Ref: 160d3495161 Ref: library/heapq heapq heapreplace3495258 Ref: 16113495258 Ref: library/heapq heapq merge3496105 Ref: 6df3496105 Ref: library/heapq heapq nlargest3497269 Ref: 16123497269 Ref: library/heapq heapq nsmallest3497667 Ref: 16133497667 Ref: heapq — Heap queue algorithm-Footnote-13498536 Node: Basic Examples3498600 Ref: library/heapq basic-examples3498725 Ref: 16143498725 Ref: Basic Examples-Footnote-13499692 Node: Priority Queue Implementation Notes3499739 Ref: library/heapq priority-queue-implementation-notes3499879 Ref: 16153499879 Ref: Priority Queue Implementation Notes-Footnote-13502815 Node: Theory3502868 Ref: library/heapq theory3502985 Ref: 16163502985 Ref: Theory-Footnote-13507145 Node: bisect — Array bisection algorithm3507805 Ref: library/bisect doc3507980 Ref: 16173507980 Ref: library/bisect bisect-array-bisection-algorithm3507980 Ref: 16183507980 Ref: library/bisect module-bisect3507980 Ref: 123507980 Ref: library/bisect bisect bisect_left3508677 Ref: 16193508677 Ref: library/bisect bisect bisect_right3509423 Ref: 161a3509423 Ref: library/bisect bisect bisect3509481 Ref: 161b3509481 Ref: library/bisect bisect insort_left3509908 Ref: 161c3509908 Ref: library/bisect bisect insort_right3510219 Ref: 161d3510219 Ref: library/bisect bisect insort3510277 Ref: 161e3510277 Ref: bisect — Array bisection algorithm-Footnote-13510795 Ref: bisect — Array bisection algorithm-Footnote-23510860 Node: Searching Sorted Lists3510930 Ref: library/bisect searching-sorted-lists3511048 Ref: 161f3511048 Node: Other Examples3512270 Ref: library/bisect other-examples3512388 Ref: 16203512388 Ref: library/bisect bisect-example3512435 Ref: 16213512435 Node: array — Efficient arrays of numeric values3513760 Ref: library/array doc3513932 Ref: 16223513932 Ref: library/array array-efficient-arrays-of-numeric-values3513932 Ref: 16233513932 Ref: library/array module-array3513932 Ref: 73513932 Ref: library/array array array3518476 Ref: 4513518476 Ref: library/array array typecodes3519196 Ref: 16283519196 Ref: library/array array array typecode3519714 Ref: 16293519714 Ref: library/array array array itemsize3519800 Ref: 162a3519800 Ref: library/array array array append3519912 Ref: 162b3519912 Ref: library/array array array buffer_info3520006 Ref: 162c3520006 Ref: library/array array array byteswap3521036 Ref: 162d3521036 Ref: library/array array array count3521363 Ref: 162e3521363 Ref: library/array array array extend3521452 Ref: 16273521452 Ref: library/array array array frombytes3521812 Ref: 16253521812 Ref: library/array array array fromfile3522134 Ref: 162f3522134 Ref: library/array array array fromlist3522549 Ref: 16243522549 Ref: library/array array array fromstring3522746 Ref: 16303522746 Ref: library/array array array fromunicode3522899 Ref: 16263522899 Ref: library/array array array index3523213 Ref: 16313523213 Ref: library/array array array insert3523349 Ref: 16323523349 Ref: library/array array array pop3523536 Ref: 16333523536 Ref: library/array array array remove3523750 Ref: 16343523750 Ref: library/array array array reverse3523837 Ref: 16353523837 Ref: library/array array array tobytes3523918 Ref: 16363523918 Ref: library/array array array tofile3524251 Ref: 16373524251 Ref: library/array array array tolist3524364 Ref: 16393524364 Ref: library/array array array tostring3524458 Ref: 16383524458 Ref: library/array array array tounicode3524607 Ref: 163a3524607 Ref: array — Efficient arrays of numeric values-Footnote-13525983 Node: weakref — Weak references3526019 Ref: library/weakref doc3526215 Ref: 163b3526215 Ref: library/weakref module-weakref3526215 Ref: 1283526215 Ref: library/weakref weakref-weak-references3526215 Ref: 163c3526215 Ref: library/weakref weakref ref3530004 Ref: 9103530004 Ref: library/weakref weakref ref __callback__3531814 Ref: 9113531814 Ref: library/weakref weakref proxy3532179 Ref: 2503532179 Ref: library/weakref weakref getweakrefcount3533045 Ref: 16403533045 Ref: library/weakref weakref getweakrefs3533178 Ref: 16413533178 Ref: library/weakref weakref WeakKeyDictionary3533312 Ref: 163d3533312 Ref: library/weakref weakref WeakKeyDictionary keyrefs3534156 Ref: 16423534156 Ref: library/weakref weakref WeakValueDictionary3534259 Ref: 163e3534259 Ref: library/weakref weakref WeakValueDictionary valuerefs3534635 Ref: 16433534635 Ref: library/weakref weakref WeakSet3534744 Ref: cb83534744 Ref: library/weakref weakref WeakMethod3534928 Ref: 90f3534928 Ref: library/weakref weakref finalize3535863 Ref: 29d3535863 Ref: library/weakref weakref finalize __call__3537162 Ref: 16443537162 Ref: library/weakref weakref finalize detach3537373 Ref: 16453537373 Ref: library/weakref weakref finalize peek3537574 Ref: 16463537574 Ref: library/weakref weakref finalize alive3537743 Ref: 16473537743 Ref: library/weakref weakref finalize atexit3537858 Ref: 16483537858 Ref: library/weakref weakref ReferenceType3538457 Ref: 16493538457 Ref: library/weakref weakref ProxyType3538541 Ref: 164a3538541 Ref: library/weakref weakref CallableProxyType3538639 Ref: 164b3538639 Ref: library/weakref weakref ProxyTypes3538731 Ref: 164c3538731 Ref: weakref — Weak references-Footnote-13539361 Ref: weakref — Weak references-Footnote-23539427 Node: Weak Reference Objects3539476 Ref: library/weakref weak-reference-objects3539581 Ref: 164d3539581 Ref: library/weakref weakref-objects3539581 Ref: 164e3539581 Node: Example<2>3542139 Ref: library/weakref example3542270 Ref: 164f3542270 Ref: library/weakref weakref-example3542270 Ref: 16503542270 Node: Finalizer Objects3542811 Ref: library/weakref finalize-examples3542961 Ref: 16513542961 Ref: library/weakref finalizer-objects3542961 Ref: 16523542961 Node: Comparing finalizers with __del__ methods3544812 Ref: library/weakref comparing-finalizers-with-del-methods3544943 Ref: 16533544943 Node: types — Dynamic type creation and names for built-in types3547767 Ref: library/types doc3547960 Ref: 16543547960 Ref: library/types module-types3547960 Ref: 1183547960 Ref: library/types types-dynamic-type-creation-and-names-for-built-in-types3547960 Ref: 16553547960 Ref: types — Dynamic type creation and names for built-in types-Footnote-13548761 Node: Dynamic Type Creation3548825 Ref: library/types dynamic-type-creation3548978 Ref: 16563548978 Ref: library/types types new_class3549039 Ref: ab73549039 Ref: library/types types prepare_class3549751 Ref: ab83549751 Ref: library/types types resolve_bases3550920 Ref: 4063550920 Ref: Dynamic Type Creation-Footnote-13551591 Ref: Dynamic Type Creation-Footnote-23551640 Ref: Dynamic Type Creation-Footnote-33551689 Node: Standard Interpreter Types3551738 Ref: library/types standard-interpreter-types3551940 Ref: 16573551940 Ref: library/types types FunctionType3552494 Ref: 16583552494 Ref: library/types types LambdaType3552523 Ref: 16593552523 Ref: library/types types GeneratorType3552878 Ref: 165a3552878 Ref: library/types types CoroutineType3553004 Ref: 77d3553004 Ref: library/types types AsyncGeneratorType3553159 Ref: 165b3553159 Ref: library/types types CodeType3553343 Ref: 1983553343 Ref: library/types types CodeType replace3553920 Ref: 165c3553920 Ref: library/types types CellType3554084 Ref: 10cb3554084 Ref: library/types types MethodType3554245 Ref: 165d3554245 Ref: library/types types BuiltinFunctionType3554332 Ref: 165e3554332 Ref: library/types types BuiltinMethodType3554368 Ref: 165f3554368 Ref: library/types types WrapperDescriptorType3554591 Ref: 4023554591 Ref: library/types types MethodWrapperType3554806 Ref: 4033554806 Ref: library/types types MethodDescriptorType3555007 Ref: 4043555007 Ref: library/types types ClassMethodDescriptorType3555162 Ref: 4053555162 Ref: library/types types ModuleType3555347 Ref: 6f13555347 Ref: library/types types ModuleType __doc__3555710 Ref: 16603555710 Ref: library/types types ModuleType __loader__3555817 Ref: 16613555817 Ref: library/types types ModuleType __name__3556562 Ref: 16633556562 Ref: library/types types ModuleType __package__3556705 Ref: 16653556705 Ref: library/types types ModuleType __spec__3557718 Ref: 16673557718 Ref: library/types types TracebackType3557944 Ref: 3353557944 Ref: library/types types FrameType3558255 Ref: 16683558255 Ref: library/types types GetSetDescriptorType3558496 Ref: 16693558496 Ref: library/types types MemberDescriptorType3558857 Ref: 166a3558857 Ref: library/types types MappingProxyType3559375 Ref: ab63559375 Ref: library/types types MappingProxyType copy3560208 Ref: 166b3560208 Ref: library/types types MappingProxyType get3560294 Ref: 166c3560294 Ref: library/types types MappingProxyType items3560567 Ref: 166d3560567 Ref: library/types types MappingProxyType keys3560697 Ref: 166e3560697 Ref: library/types types MappingProxyType values3560788 Ref: 166f3560788 Node: Additional Utility Classes and Functions3560883 Ref: library/types additional-utility-classes-and-functions3561091 Ref: 16703561091 Ref: library/types types SimpleNamespace3561190 Ref: 9ac3561190 Ref: library/types types DynamicClassAttribute3562451 Ref: 8f33562451 Node: Coroutine Utility Functions3563108 Ref: library/types coroutine-utility-functions3563281 Ref: 16713563281 Ref: library/types types coroutine3563354 Ref: 77c3563354 Node: copy — Shallow and deep copy operations3564178 Ref: library/copy doc3564374 Ref: 16723564374 Ref: library/copy copy-shallow-and-deep-copy-operations3564374 Ref: 16733564374 Ref: library/copy module-copy3564374 Ref: 263564374 Ref: library/copy copy copy3564929 Ref: 3cb3564929 Ref: library/copy copy deepcopy3564994 Ref: 3cc3564994 Ref: library/copy copy error3565068 Ref: 16743565068 Ref: library/copy shallow-vs-deep-copy3565135 Ref: ebd3565135 Ref: copy — Shallow and deep copy operations-Footnote-13567782 Node: pprint — Data pretty printer3567845 Ref: library/pprint doc3568022 Ref: 16753568022 Ref: library/pprint module-pprint3568022 Ref: d23568022 Ref: library/pprint pprint-data-pretty-printer3568022 Ref: 16763568022 Ref: library/pprint pprint PrettyPrinter3569020 Ref: 8953569020 Ref: library/pprint pprint pformat3571692 Ref: 8963571692 Ref: library/pprint pprint pp3572156 Ref: 2123572156 Ref: library/pprint pprint pprint3572581 Ref: 2133572581 Ref: library/pprint pprint isreadable3573662 Ref: 16773573662 Ref: library/pprint pprint isrecursive3573970 Ref: 16783573970 Ref: library/pprint pprint saferepr3574122 Ref: 16793574122 Ref: pprint — Data pretty printer-Footnote-13574706 Node: PrettyPrinter Objects3574771 Ref: library/pprint id13574878 Ref: 167a3574878 Ref: library/pprint prettyprinter-objects3574878 Ref: 167b3574878 Ref: library/pprint pprint PrettyPrinter pformat3575006 Ref: 167c3575006 Ref: library/pprint pprint PrettyPrinter pprint3575205 Ref: 167d3575205 Ref: library/pprint pprint PrettyPrinter isreadable3575592 Ref: 167e3575592 Ref: library/pprint pprint PrettyPrinter isrecursive3575994 Ref: 167f3575994 Ref: library/pprint pprint PrettyPrinter format3576310 Ref: 16803576310 Node: Example<3>3577469 Ref: library/pprint example3577576 Ref: 16813577576 Ref: library/pprint pprint-example3577576 Ref: 16823577576 Ref: Example<3>-Footnote-13584886 Node: reprlib — Alternate repr implementation3584911 Ref: library/reprlib doc3585080 Ref: 16833585080 Ref: library/reprlib module-reprlib3585080 Ref: df3585080 Ref: library/reprlib reprlib-alternate-repr-implementation3585080 Ref: 16843585080 Ref: library/reprlib reprlib Repr3585576 Ref: 16853585576 Ref: library/reprlib reprlib aRepr3585860 Ref: 16863585860 Ref: library/reprlib reprlib repr3586143 Ref: 16873586143 Ref: library/reprlib reprlib recursive_repr3586545 Ref: b703586545 Ref: reprlib — Alternate repr implementation-Footnote-13587347 Node: Repr Objects3587413 Ref: library/reprlib id13587536 Ref: 16893587536 Ref: library/reprlib repr-objects3587536 Ref: 168a3587536 Ref: library/reprlib reprlib Repr maxlevel3587777 Ref: 168b3587777 Ref: library/reprlib reprlib Repr maxdict3587901 Ref: 168c3587901 Ref: library/reprlib reprlib Repr maxlist3587929 Ref: 168d3587929 Ref: library/reprlib reprlib Repr maxtuple3587957 Ref: 168e3587957 Ref: library/reprlib reprlib Repr maxset3587986 Ref: 168f3587986 Ref: library/reprlib reprlib Repr maxfrozenset3588013 Ref: 16903588013 Ref: library/reprlib reprlib Repr maxdeque3588046 Ref: 16913588046 Ref: library/reprlib reprlib Repr maxarray3588075 Ref: 16923588075 Ref: library/reprlib reprlib Repr maxlong3588303 Ref: 16933588303 Ref: library/reprlib reprlib Repr maxstring3588472 Ref: 16943588472 Ref: library/reprlib reprlib Repr maxother3588829 Ref: 16953588829 Ref: library/reprlib reprlib Repr repr3589108 Ref: 16883589108 Ref: library/reprlib reprlib Repr repr13589248 Ref: 16963589248 Node: Subclassing Repr Objects3590066 Ref: library/reprlib subclassing-repr-objects3590189 Ref: 16973590189 Ref: library/reprlib subclassing-reprs3590189 Ref: 16983590189 Node: enum — Support for enumerations3590872 Ref: library/enum doc3591002 Ref: 16993591002 Ref: library/enum enum-support-for-enumerations3591002 Ref: 169a3591002 Ref: library/enum module-enum3591002 Ref: 7b3591002 Ref: enum — Support for enumerations-Footnote-13592199 Node: Module Contents<2>3592262 Ref: library/enum module-contents3592375 Ref: 169b3592375 Ref: library/enum enum Enum3592698 Ref: 3873592698 Ref: library/enum enum IntEnum3592856 Ref: 58d3592856 Ref: library/enum enum IntFlag3592981 Ref: 14033592981 Ref: library/enum enum Flag3593244 Ref: 5453593244 Ref: library/enum enum auto3593543 Ref: 5463593543 Node: Creating an Enum3593729 Ref: library/enum creating-an-enum3593914 Ref: 169e3593914 Node: Programmatic access to enumeration members and their attributes3596360 Ref: library/enum programmatic-access-to-enumeration-members-and-their-attributes3596562 Ref: 16a03596562 Node: Duplicating enum members and values3597320 Ref: library/enum duplicating-enum-members-and-values3597540 Ref: 16a13597540 Node: Ensuring unique enumeration values3598631 Ref: library/enum ensuring-unique-enumeration-values3598810 Ref: 16a23598810 Ref: library/enum enum unique3599109 Ref: 169c3599109 Node: Using automatic values3599656 Ref: library/enum using-automatic-values3599809 Ref: 16a33599809 Node: Iteration3601022 Ref: library/enum iteration3601155 Ref: 16a43601155 Node: Comparisons<3>3602017 Ref: library/enum comparisons3602174 Ref: 16a53602174 Node: Allowed members and attributes of enumerations3603098 Ref: library/enum allowed-members-and-attributes-of-enumerations3603273 Ref: 16a73603273 Node: Restricted Enum subclassing3605110 Ref: library/enum restricted-enum-subclassing3605279 Ref: 16a93605279 Node: Pickling3606380 Ref: library/enum pickling3606517 Ref: 16ab3606517 Node: Functional API3607161 Ref: library/enum functional-api3607291 Ref: 169d3607291 Node: Derived Enumerations3610551 Ref: library/enum derived-enumerations3610704 Ref: 16ad3610704 Node: IntEnum3610821 Ref: library/enum intenum3610901 Ref: 16a63610901 Node: IntFlag3612028 Ref: library/enum intflag3612121 Ref: 16ae3612121 Node: Flag3613659 Ref: library/enum flag3613751 Ref: 16af3613751 Node: Others3615869 Ref: library/enum others3615945 Ref: 16b03615945 Node: When to use __new__ vs __init__3617746 Ref: library/enum when-to-use-new-vs-init3617905 Ref: 16b13617905 Node: Interesting examples3619023 Ref: library/enum interesting-examples3619186 Ref: 16b23619186 Node: Omitting values3619633 Ref: library/enum omitting-values3619725 Ref: 16b33619725 Node: Using auto3620777 Ref: library/enum using-auto3620860 Ref: 16b43620860 Node: Using object3621114 Ref: library/enum using-object3621232 Ref: 16b53621232 Node: Using a descriptive string3621498 Ref: library/enum using-a-descriptive-string3621628 Ref: 16b63621628 Node: Using a custom __new__3621951 Ref: library/enum using-a-custom-new3622060 Ref: 16b73622060 Node: OrderedEnum3623763 Ref: library/enum orderedenum3623881 Ref: 16aa3623881 Node: DuplicateFreeEnum3625063 Ref: library/enum duplicatefreeenum3625172 Ref: 16b83625172 Node: Planet3626251 Ref: library/enum planet3626359 Ref: 16a83626359 Node: TimePeriod3627421 Ref: library/enum timeperiod3627503 Ref: 16b93627503 Node: How are Enums different?3628118 Ref: library/enum how-are-enums-different3628241 Ref: 169f3628241 Node: Enum Classes3628533 Ref: library/enum enum-classes3628641 Ref: 16ba3628641 Node: Enum Members aka instances3629219 Ref: library/enum enum-members-aka-instances3629348 Ref: 16bb3629348 Node: Finer Points3629744 Ref: library/enum finer-points3629852 Ref: 16bc3629852 Node: Supported __dunder__ names3630096 Ref: library/enum supported-dunder-names3630204 Ref: 16bd3630204 Node: Supported _sunder_ names3630627 Ref: library/enum supported-sunder-names3630760 Ref: 16be3630760 Node: Enum member type3632262 Ref: library/enum enum-member-type3632410 Ref: 16bf3632410 Node: Boolean value of Enum classes and members3633125 Ref: library/enum boolean-value-of-enum-classes-and-members3633274 Ref: 16c03633274 Node: Enum classes with methods3633847 Ref: library/enum enum-classes-with-methods3634005 Ref: 16c13634005 Node: Combining members of Flag3634541 Ref: library/enum combining-members-of-flag3634649 Ref: 16c23634649 Node: Numeric and Mathematical Modules3635269 Ref: library/numeric doc3635423 Ref: 16c33635423 Ref: library/numeric numeric3635423 Ref: 16c43635423 Ref: library/numeric numeric-and-mathematical-modules3635423 Ref: 16c53635423 Node: numbers — Numeric abstract base classes3636328 Ref: library/numbers doc3636478 Ref: 16c63636478 Ref: library/numbers module-numbers3636478 Ref: c13636478 Ref: library/numbers numbers-numeric-abstract-base-classes3636478 Ref: 16c73636478 Ref: library/numbers numbers Number3636901 Ref: 10c23636901 Ref: numbers — Numeric abstract base classes-Footnote-13637197 Ref: numbers — Numeric abstract base classes-Footnote-23637263 Node: The numeric tower3637312 Ref: library/numbers the-numeric-tower3637443 Ref: 16c83637443 Ref: library/numbers numbers Complex3637496 Ref: 10c53637496 Ref: library/numbers numbers Complex real3637936 Ref: 16c93637936 Ref: library/numbers numbers Complex imag3638029 Ref: 16ca3638029 Ref: library/numbers numbers Complex conjugate3638127 Ref: 16cb3638127 Ref: library/numbers numbers Real3638286 Ref: 10c43638286 Ref: library/numbers numbers Rational3638793 Ref: c583638793 Ref: library/numbers numbers Rational numerator3639030 Ref: 16cc3639030 Ref: library/numbers numbers Rational denominator3639082 Ref: 16cd3639082 Ref: library/numbers numbers Integral3639136 Ref: 10c33639136 Node: Notes for type implementors3639471 Ref: library/numbers notes-for-type-implementors3639602 Ref: 16ce3639602 Node: Adding More Numeric ABCs3640452 Ref: library/numbers adding-more-numeric-abcs3640587 Ref: 16cf3640587 Node: Implementing the arithmetic operations3640933 Ref: library/numbers id13641068 Ref: 16d03641068 Ref: library/numbers implementing-the-arithmetic-operations3641068 Ref: 10c13641068 Node: math — Mathematical functions3645864 Ref: library/math doc3646075 Ref: 16d13646075 Ref: library/math math-mathematical-functions3646075 Ref: 16d23646075 Ref: library/math module-math3646075 Ref: b13646075 Node: Number-theoretic and representation functions3647245 Ref: library/math number-theoretic-and-representation-functions3647398 Ref: 16d33647398 Ref: library/math math ceil3647507 Ref: d2d3647507 Ref: library/math math comb3647739 Ref: 1e73647739 Ref: library/math math copysign3648350 Ref: d3d3648350 Ref: library/math math fabs3648564 Ref: 16d43648564 Ref: library/math math factorial3648633 Ref: 1ea3648633 Ref: library/math math floor3648784 Ref: d2c3648784 Ref: library/math math fmod3649012 Ref: 11df3649012 Ref: library/math math frexp3649998 Ref: 16d53649998 Ref: library/math math fsum3650363 Ref: d3e3650363 Ref: library/math math gcd3651202 Ref: 7163651202 Ref: library/math math isclose3651509 Ref: 6863651509 Ref: library/math math isfinite3652855 Ref: b673652855 Ref: library/math math isinf3653058 Ref: d3b3653058 Ref: library/math math isnan3653187 Ref: d3c3653187 Ref: library/math math isqrt3653305 Ref: 1e83653305 Ref: library/math math ldexp3653823 Ref: 16d63653823 Ref: library/math math modf3653958 Ref: 16d73653958 Ref: library/math math perm3654098 Ref: 1e63654098 Ref: library/math math prod3654639 Ref: 1e43654639 Ref: library/math math remainder3655015 Ref: 3ab3655015 Ref: library/math math trunc3656041 Ref: d2e3656041 Ref: Number-theoretic and representation functions-Footnote-13656929 Ref: Number-theoretic and representation functions-Footnote-23656982 Node: Power and logarithmic functions3657031 Ref: library/math power-and-logarithmic-functions3657216 Ref: 16d83657216 Ref: library/math math exp3657297 Ref: ca93657297 Ref: library/math math expm13657515 Ref: b683657515 Ref: library/math math log3658128 Ref: e113658128 Ref: library/math math log1p3658363 Ref: d423658363 Ref: library/math math log23658526 Ref: a203658526 Ref: library/math math log103658866 Ref: 16d93658866 Ref: library/math math pow3658998 Ref: 16da3658998 Ref: library/math math sqrt3659694 Ref: 1e93659694 Ref: Power and logarithmic functions-Footnote-13659796 Node: Trigonometric functions3659855 Ref: library/math trigonometric-functions3660013 Ref: 16db3660013 Ref: library/math math acos3660078 Ref: 16dc3660078 Ref: library/math math asin3660155 Ref: 16dd3660155 Ref: library/math math atan3660230 Ref: 16de3660230 Ref: library/math math atan23660308 Ref: 16df3660308 Ref: library/math math cos3660820 Ref: e103660820 Ref: library/math math dist3660888 Ref: 1e23660888 Ref: library/math math hypot3661217 Ref: 1e33661217 Ref: library/math math sin3661742 Ref: e0f3661742 Ref: library/math math tan3661808 Ref: 16e03661808 Node: Angular conversion3661877 Ref: library/math angular-conversion3662024 Ref: 16e13662024 Ref: library/math math degrees3662079 Ref: 16e23662079 Ref: library/math math radians3662160 Ref: 16e33662160 Node: Hyperbolic functions3662241 Ref: library/math hyperbolic-functions3662382 Ref: 16e43662382 Ref: library/math math acosh3662554 Ref: d3f3662554 Ref: library/math math asinh3662635 Ref: d403662635 Ref: library/math math atanh3662714 Ref: d413662714 Ref: library/math math cosh3662796 Ref: 16e53662796 Ref: library/math math sinh3662868 Ref: 16e63662868 Ref: library/math math tanh3662938 Ref: 16e73662938 Ref: Hyperbolic functions-Footnote-13663047 Node: Special functions3663105 Ref: library/math special-functions3663240 Ref: 16e83663240 Ref: library/math math erf3663293 Ref: 4523663293 Ref: library/math math erfc3663713 Ref: 4533663713 Ref: library/math math gamma3664012 Ref: b693664012 Ref: library/math math lgamma3664111 Ref: b6a3664111 Ref: Special functions-Footnote-13664296 Ref: Special functions-Footnote-23664349 Ref: Special functions-Footnote-33664441 Ref: Special functions-Footnote-43664494 Ref: Special functions-Footnote-53664553 Node: Constants<2>3664606 Ref: library/math constants3664712 Ref: 16e93664712 Ref: library/math math pi3664749 Ref: 16ea3664749 Ref: library/math math e3664844 Ref: 16eb3664844 Ref: library/math math tau3664937 Ref: 16ec3664937 Ref: library/math math inf3665315 Ref: 5283665315 Ref: library/math math nan3665504 Ref: 5293665504 Ref: Constants<2>-Footnote-13666834 Ref: Constants<2>-Footnote-23666886 Node: cmath — Mathematical functions for complex numbers3666914 Ref: library/cmath doc3667145 Ref: 16ed3667145 Ref: library/cmath cmath-mathematical-functions-for-complex-numbers3667145 Ref: 16ee3667145 Ref: library/cmath module-cmath3667145 Ref: 193667145 Node: Conversions to and from polar coordinates3668437 Ref: library/cmath conversions-to-and-from-polar-coordinates3668610 Ref: 16ef3668610 Ref: library/cmath cmath phase3669462 Ref: 16f03669462 Ref: library/cmath cmath polar3670368 Ref: 16f13670368 Ref: library/cmath cmath rect3670621 Ref: 16f23670621 Node: Power and logarithmic functions<2>3670795 Ref: library/cmath power-and-logarithmic-functions3671003 Ref: 16f33671003 Ref: library/cmath cmath exp3671084 Ref: 16f43671084 Ref: library/cmath cmath log3671205 Ref: 16f53671205 Ref: library/cmath cmath log103671478 Ref: 16f63671478 Ref: library/cmath cmath sqrt3671609 Ref: 16f73671609 Node: Trigonometric functions<2>3671733 Ref: library/cmath trigonometric-functions3671923 Ref: 16f83671923 Ref: library/cmath cmath acos3671988 Ref: 16f93671988 Ref: library/cmath cmath asin3672257 Ref: 16fa3672257 Ref: library/cmath cmath atan3672380 Ref: 16fb3672380 Ref: library/cmath cmath cos3672684 Ref: 16fc3672684 Ref: library/cmath cmath sin3672745 Ref: 16fd3672745 Ref: library/cmath cmath tan3672804 Ref: 16fe3672804 Node: Hyperbolic functions<2>3672866 Ref: library/cmath hyperbolic-functions3673046 Ref: 16ff3673046 Ref: library/cmath cmath acosh3673105 Ref: 17003673105 Ref: library/cmath cmath asinh3673297 Ref: 17013673297 Ref: library/cmath cmath atanh3673614 Ref: 17023673614 Ref: library/cmath cmath cosh3673913 Ref: 17033673913 Ref: library/cmath cmath sinh3673986 Ref: 17043673986 Ref: library/cmath cmath tanh3674057 Ref: 17053674057 Node: Classification functions3674131 Ref: library/cmath classification-functions3674297 Ref: 17063674297 Ref: library/cmath cmath isfinite3674364 Ref: 17073674364 Ref: library/cmath cmath isinf3674536 Ref: 17083674536 Ref: library/cmath cmath isnan3674687 Ref: 17093674687 Ref: library/cmath cmath isclose3674832 Ref: 6873674832 Ref: Classification functions-Footnote-13676215 Node: Constants<3>3676264 Ref: library/cmath constants3676398 Ref: 170a3676398 Ref: library/cmath cmath pi3676435 Ref: 170b3676435 Ref: library/cmath cmath e3676505 Ref: 170c3676505 Ref: library/cmath cmath tau3676573 Ref: 5253676573 Ref: library/cmath cmath inf3676670 Ref: 5263676670 Ref: library/cmath cmath infj3676792 Ref: 52a3676792 Ref: library/cmath cmath nan3676973 Ref: 5273676973 Ref: library/cmath cmath nanj3677115 Ref: 52b3677115 Node: decimal — Decimal fixed point and floating point arithmetic3678526 Ref: library/decimal doc3678756 Ref: 170d3678756 Ref: library/decimal decimal-decimal-fixed-point-and-floating-point-arithmetic3678756 Ref: 170e3678756 Ref: library/decimal module-decimal3678756 Ref: 363678756 Ref: decimal — Decimal fixed point and floating point arithmetic-Footnote-13683879 Ref: decimal — Decimal fixed point and floating point arithmetic-Footnote-23683945 Node: Quick-start Tutorial3683998 Ref: library/decimal decimal-tutorial3684140 Ref: 171e3684140 Ref: library/decimal quick-start-tutorial3684140 Ref: 171f3684140 Node: Decimal objects3691360 Ref: library/decimal decimal-decimal3691526 Ref: 17223691526 Ref: library/decimal decimal-objects3691526 Ref: 17233691526 Ref: library/decimal decimal Decimal3691575 Ref: 1883691575 Ref: library/decimal decimal Decimal adjusted3696701 Ref: 17243696701 Ref: library/decimal decimal Decimal as_integer_ratio3697052 Ref: 53b3697052 Ref: library/decimal decimal Decimal as_tuple3697491 Ref: 17253697491 Ref: library/decimal decimal Decimal canonical3697649 Ref: 17263697649 Ref: library/decimal decimal Decimal compare3697888 Ref: 17273697888 Ref: library/decimal decimal Decimal compare_signal3698321 Ref: 17283698321 Ref: library/decimal decimal Decimal compare_total3698633 Ref: 17293698633 Ref: library/decimal decimal Decimal compare_total_mag3699910 Ref: 172a3699910 Ref: library/decimal decimal Decimal conjugate3700515 Ref: 172b3700515 Ref: library/decimal decimal Decimal copy_abs3700648 Ref: 172c3700648 Ref: library/decimal decimal Decimal copy_negate3700862 Ref: 172d3700862 Ref: library/decimal decimal Decimal copy_sign3701073 Ref: 172e3701073 Ref: library/decimal decimal Decimal exp3701610 Ref: 9ed3701610 Ref: library/decimal decimal Decimal from_float3702044 Ref: b803702044 Ref: library/decimal decimal Decimal fma3703146 Ref: 172f3703146 Ref: library/decimal decimal Decimal is_canonical3703390 Ref: 17303703390 Ref: library/decimal decimal Decimal is_finite3703665 Ref: 17313703665 Ref: library/decimal decimal Decimal is_infinite3703840 Ref: 17323703840 Ref: library/decimal decimal Decimal is_nan3704007 Ref: 17333704007 Ref: library/decimal decimal Decimal is_normal3704159 Ref: 17343704159 Ref: library/decimal decimal Decimal is_qnan3704383 Ref: 17353704383 Ref: library/decimal decimal Decimal is_signed3704522 Ref: 17363704522 Ref: library/decimal decimal Decimal is_snan3704725 Ref: 17373704725 Ref: library/decimal decimal Decimal is_subnormal3704867 Ref: 17383704867 Ref: library/decimal decimal Decimal is_zero3705021 Ref: 17393705021 Ref: library/decimal decimal Decimal ln3705177 Ref: 9ee3705177 Ref: library/decimal decimal Decimal log103705385 Ref: 173a3705385 Ref: library/decimal decimal Decimal logb3705588 Ref: 173b3705588 Ref: library/decimal decimal Decimal logical_and3705975 Ref: 173c3705975 Ref: library/decimal decimal Decimal logical_invert3706240 Ref: 173e3706240 Ref: library/decimal decimal Decimal logical_or3706419 Ref: 173f3706419 Ref: library/decimal decimal Decimal logical_xor3706681 Ref: 17403706681 Ref: library/decimal decimal Decimal max3706949 Ref: 17413706949 Ref: library/decimal decimal Decimal max_mag3707253 Ref: 17423707253 Ref: library/decimal decimal Decimal min3707434 Ref: 17433707434 Ref: library/decimal decimal Decimal min_mag3707738 Ref: 17443707738 Ref: library/decimal decimal Decimal next_minus3707919 Ref: 17453707919 Ref: library/decimal decimal Decimal next_plus3708157 Ref: 17463708157 Ref: library/decimal decimal Decimal next_toward3708394 Ref: 17473708394 Ref: library/decimal decimal Decimal normalize3708761 Ref: 17483708761 Ref: library/decimal decimal Decimal number_class3709217 Ref: 17493709217 Ref: library/decimal decimal Decimal quantize3710387 Ref: 9f13710387 Ref: library/decimal decimal Decimal radix3711680 Ref: 174a3711680 Ref: library/decimal decimal Decimal remainder_near3711897 Ref: 174b3711897 Ref: library/decimal decimal Decimal rotate3712741 Ref: 174c3712741 Ref: library/decimal decimal Decimal same_quantum3713414 Ref: 174d3713414 Ref: library/decimal decimal Decimal scaleb3713826 Ref: 174e3713826 Ref: library/decimal decimal Decimal shift3714077 Ref: 174f3714077 Ref: library/decimal decimal Decimal sqrt3714683 Ref: 17503714683 Ref: library/decimal decimal Decimal to_eng_string3714790 Ref: 17513714790 Ref: library/decimal decimal Decimal to_integral3715266 Ref: 17523715266 Ref: library/decimal decimal Decimal to_integral_exact3715496 Ref: 17543715496 Ref: library/decimal decimal Decimal to_integral_value3715926 Ref: 17533715926 Node: Logical operands3716280 Ref: library/decimal logical-operands3716348 Ref: 17553716348 Ref: library/decimal logical-operands-label3716348 Ref: 173d3716348 Node: Context objects3716695 Ref: library/decimal context-objects3716853 Ref: 17563716853 Ref: library/decimal decimal-context3716853 Ref: 17573716853 Ref: library/decimal decimal getcontext3717237 Ref: 17203717237 Ref: library/decimal decimal setcontext3717330 Ref: 17213717330 Ref: library/decimal decimal localcontext3717564 Ref: 13883717564 Ref: library/decimal decimal BasicContext3718489 Ref: 9e93718489 Ref: library/decimal decimal ExtendedContext3718941 Ref: 9ea3718941 Ref: library/decimal decimal DefaultContext3719574 Ref: 9e83719574 Ref: library/decimal decimal Context3720676 Ref: 9f03720676 Ref: library/decimal decimal Context clear_flags3723595 Ref: 175c3723595 Ref: library/decimal decimal Context clear_traps3723675 Ref: 175d3723675 Ref: library/decimal decimal Context copy3723786 Ref: 175e3723786 Ref: library/decimal decimal Context copy_decimal3723858 Ref: 175f3723858 Ref: library/decimal decimal Context create_decimal3723949 Ref: 9ec3723949 Ref: library/decimal decimal Context create_decimal_from_float3725053 Ref: 17603725053 Ref: library/decimal decimal Context Etiny3725816 Ref: 17613725816 Ref: library/decimal decimal Context Etop3726046 Ref: 17623726046 Ref: library/decimal decimal Context abs3726552 Ref: 17633726552 Ref: library/decimal decimal Context add3726624 Ref: 17643726624 Ref: library/decimal decimal Context canonical3726695 Ref: c9d3726695 Ref: library/decimal decimal Context compare3726775 Ref: 17653726775 Ref: library/decimal decimal Context compare_signal3726853 Ref: 17663726853 Ref: library/decimal decimal Context compare_total3726957 Ref: 17673726957 Ref: library/decimal decimal Context compare_total_mag3727066 Ref: 17683727066 Ref: library/decimal decimal Context copy_abs3727204 Ref: 17693727204 Ref: library/decimal decimal Context copy_negate3727292 Ref: 176a3727292 Ref: library/decimal decimal Context copy_sign3727383 Ref: 176b3727383 Ref: library/decimal decimal Context divide3727462 Ref: 176c3727462 Ref: library/decimal decimal Context divide_int3727532 Ref: 176d3727532 Ref: library/decimal decimal Context divmod3727631 Ref: 176e3727631 Ref: library/decimal decimal Context exp3727748 Ref: 176f3727748 Ref: library/decimal decimal Context fma3727807 Ref: 17703727807 Ref: library/decimal decimal Context is_canonical3727891 Ref: c9e3727891 Ref: library/decimal decimal Context is_finite3728008 Ref: 17713728008 Ref: library/decimal decimal Context is_infinite3728119 Ref: 17723728119 Ref: library/decimal decimal Context is_nan3728234 Ref: 17733728234 Ref: library/decimal decimal Context is_normal3728360 Ref: 17743728360 Ref: library/decimal decimal Context is_qnan3728490 Ref: 17753728490 Ref: library/decimal decimal Context is_signed3728614 Ref: 17763728614 Ref: library/decimal decimal Context is_snan3728727 Ref: 17773728727 Ref: library/decimal decimal Context is_subnormal3728855 Ref: 17783728855 Ref: library/decimal decimal Context is_zero3728972 Ref: 17793728972 Ref: library/decimal decimal Context ln3729081 Ref: 177a3729081 Ref: library/decimal decimal Context log103729164 Ref: 177b3729164 Ref: library/decimal decimal Context logb3729241 Ref: 177c3729241 Ref: library/decimal decimal Context logical_and3729341 Ref: 177d3729341 Ref: library/decimal decimal Context logical_invert3729468 Ref: 177e3729468 Ref: library/decimal decimal Context logical_or3729546 Ref: 177f3729546 Ref: library/decimal decimal Context logical_xor3729671 Ref: 17803729671 Ref: library/decimal decimal Context max3729798 Ref: 17813729798 Ref: library/decimal decimal Context max_mag3729895 Ref: 17823729895 Ref: library/decimal decimal Context min3729996 Ref: 17833729996 Ref: library/decimal decimal Context min_mag3730093 Ref: 17843730093 Ref: library/decimal decimal Context minus3730194 Ref: 17853730194 Ref: library/decimal decimal Context multiply3730307 Ref: 17863730307 Ref: library/decimal decimal Context next_minus3730387 Ref: 17873730387 Ref: library/decimal decimal Context next_plus3730490 Ref: 17883730490 Ref: library/decimal decimal Context next_toward3730592 Ref: 17893730592 Ref: library/decimal decimal Context normalize3730701 Ref: 178a3730701 Ref: library/decimal decimal Context number_class3730778 Ref: 178b3730778 Ref: library/decimal decimal Context plus3730867 Ref: 178c3730867 Ref: library/decimal decimal Context power3731084 Ref: 178d3731084 Ref: library/decimal decimal Context quantize3732919 Ref: 178e3732919 Ref: library/decimal decimal Context radix3733042 Ref: 178f3733042 Ref: library/decimal decimal Context remainder3733120 Ref: 17903733120 Ref: library/decimal decimal Context remainder_near3733315 Ref: 17913733315 Ref: library/decimal decimal Context rotate3733535 Ref: 17923733535 Ref: library/decimal decimal Context same_quantum3733620 Ref: 17933733620 Ref: library/decimal decimal Context scaleb3733732 Ref: 17943733732 Ref: library/decimal decimal Context shift3733850 Ref: 17953733850 Ref: library/decimal decimal Context sqrt3733934 Ref: 17963733934 Ref: library/decimal decimal Context subtract3734031 Ref: 17973734031 Ref: library/decimal decimal Context to_eng_string3734119 Ref: 17983734119 Ref: library/decimal decimal Context to_integral_exact3734483 Ref: 17993734483 Ref: library/decimal decimal Context to_sci_string3734556 Ref: 179a3734556 Node: Constants<4>3734660 Ref: library/decimal constants3734817 Ref: 179b3734817 Ref: library/decimal decimal-rounding-modes3734817 Ref: 179c3734817 Ref: library/decimal decimal MAX_PREC3735254 Ref: 17583735254 Ref: library/decimal decimal MAX_EMAX3735389 Ref: 175b3735389 Ref: library/decimal decimal MIN_EMIN3735524 Ref: 175a3735524 Ref: library/decimal decimal MIN_ETINY3735660 Ref: 179d3735660 Ref: library/decimal decimal HAVE_THREADS3735788 Ref: 9e63735788 Ref: library/decimal decimal HAVE_CONTEXTVAR3735939 Ref: 179e3735939 Node: Rounding modes3736294 Ref: library/decimal rounding-modes3736443 Ref: 17593736443 Ref: library/decimal decimal ROUND_CEILING3736490 Ref: 170f3736490 Ref: library/decimal decimal ROUND_DOWN3736559 Ref: 17103736559 Ref: library/decimal decimal ROUND_FLOOR3736615 Ref: 17113736615 Ref: library/decimal decimal ROUND_HALF_DOWN3736683 Ref: 17123736683 Ref: library/decimal decimal ROUND_HALF_EVEN3736771 Ref: 17133736771 Ref: library/decimal decimal ROUND_HALF_UP3736870 Ref: 17143736870 Ref: library/decimal decimal ROUND_UP3736958 Ref: 17153736958 Ref: library/decimal decimal ROUND_05UP3737014 Ref: 17163737014 Node: Signals3737172 Ref: library/decimal decimal-signals3737329 Ref: 179f3737329 Ref: library/decimal signals3737329 Ref: 17a03737329 Ref: library/decimal decimal Clamped3738046 Ref: 17173738046 Ref: library/decimal decimal DecimalException3738340 Ref: 17a13738340 Ref: library/decimal decimal DivisionByZero3738464 Ref: 17183738464 Ref: library/decimal decimal Inexact3738802 Ref: 17193738802 Ref: library/decimal decimal InvalidOperation3739077 Ref: 9eb3739077 Ref: library/decimal decimal Overflow3739518 Ref: 171c3739518 Ref: library/decimal decimal Rounded3739921 Ref: 171a3739921 Ref: library/decimal decimal Subnormal3740259 Ref: 171b3740259 Ref: library/decimal decimal Underflow3740481 Ref: 171d3740481 Ref: library/decimal decimal FloatOperation3740706 Ref: 9e53740706 Node: Floating Point Notes3741978 Ref: library/decimal decimal-notes3742141 Ref: 17a23742141 Ref: library/decimal floating-point-notes3742141 Ref: 17a33742141 Node: Mitigating round-off error with increased precision3742285 Ref: library/decimal mitigating-round-off-error-with-increased-precision3742416 Ref: 17a43742416 Node: Special values3744105 Ref: library/decimal special-values3744236 Ref: 17a53744236 Node: Working with threads3747357 Ref: library/decimal decimal-threads3747520 Ref: 17a63747520 Ref: library/decimal working-with-threads3747520 Ref: 17a73747520 Node: Recipes3748893 Ref: library/decimal decimal-recipes3749047 Ref: 17a83749047 Ref: library/decimal recipes3749047 Ref: 17a93749047 Node: Decimal FAQ3753892 Ref: library/decimal decimal-faq3754017 Ref: 17aa3754017 Ref: library/decimal id13754017 Ref: 17ab3754017 Ref: Decimal FAQ-Footnote-13760328 Ref: Decimal FAQ-Footnote-23760395 Ref: Decimal FAQ-Footnote-33760453 Node: fractions — Rational numbers3760556 Ref: library/fractions doc3760775 Ref: 17ac3760775 Ref: library/fractions fractions-rational-numbers3760775 Ref: 17ad3760775 Ref: library/fractions module-fractions3760775 Ref: 833760775 Ref: library/fractions fractions Fraction3761155 Ref: 1853761155 Ref: library/fractions fractions Fraction numerator3764329 Ref: 17af3764329 Ref: library/fractions fractions Fraction denominator3764413 Ref: 17b03764413 Ref: library/fractions fractions Fraction as_integer_ratio3764501 Ref: 17b13764501 Ref: library/fractions fractions Fraction from_float3764693 Ref: b813764693 Ref: library/fractions fractions Fraction from_decimal3765152 Ref: b823765152 Ref: library/fractions fractions Fraction limit_denominator3765551 Ref: 17ae3765551 Ref: library/fractions fractions Fraction __floor__3766425 Ref: 17b23766425 Ref: library/fractions fractions Fraction __ceil__3766725 Ref: 17b33766725 Ref: library/fractions fractions Fraction __round__3766905 Ref: 17b43766905 Ref: library/fractions fractions gcd3767375 Ref: 7173767375 Ref: fractions — Rational numbers-Footnote-13767976 Node: random — Generate pseudo-random numbers3768044 Ref: library/random doc3768250 Ref: 17b53768250 Ref: library/random module-random3768250 Ref: dc3768250 Ref: library/random random-generate-pseudo-random-numbers3768250 Ref: 17b63768250 Ref: random — Generate pseudo-random numbers-Footnote-13771240 Ref: random — Generate pseudo-random numbers-Footnote-23771305 Node: Bookkeeping functions3771358 Ref: library/random bookkeeping-functions3771488 Ref: 17ba3771488 Ref: library/random random seed3771549 Ref: c083771549 Ref: library/random random getstate3772439 Ref: 17bb3772439 Ref: library/random random setstate3772637 Ref: 17bc3772637 Ref: library/random random getrandbits3772915 Ref: 9333772915 Node: Functions for integers3773275 Ref: library/random functions-for-integers3773437 Ref: 17bd3773437 Ref: library/random random randrange3773500 Ref: bbb3773500 Ref: library/random random randint3774202 Ref: bbc3774202 Node: Functions for sequences3774343 Ref: library/random functions-for-sequences3774509 Ref: 17be3774509 Ref: library/random random choice3774574 Ref: bbd3774574 Ref: library/random random choices3774729 Ref: 5743774729 Ref: library/random random shuffle3776603 Ref: bbe3776603 Ref: library/random random sample3777369 Ref: bbf3777369 Node: Real-valued distributions3778438 Ref: library/random real-valued-distributions3778603 Ref: 17bf3778603 Ref: library/random random random3778942 Ref: 17b73778942 Ref: library/random random uniform3779055 Ref: 17c03779055 Ref: library/random random triangular3779394 Ref: 17c13779394 Ref: library/random random betavariate3779751 Ref: 17c23779751 Ref: library/random random expovariate3779939 Ref: 17c33779939 Ref: library/random random gammavariate3780318 Ref: 17c43780318 Ref: library/random random gauss3780720 Ref: 17c53780720 Ref: library/random random lognormvariate3780944 Ref: 17c73780944 Ref: library/random random normalvariate3781243 Ref: 17c63781243 Ref: library/random random vonmisesvariate3781381 Ref: 17c83781381 Ref: library/random random paretovariate3781723 Ref: 17c93781723 Ref: library/random random weibullvariate3781827 Ref: 17ca3781827 Node: Alternative Generator3781978 Ref: library/random alternative-generator3782144 Ref: 17cb3782144 Ref: library/random random Random3782205 Ref: 17b83782205 Ref: library/random random SystemRandom3782354 Ref: 17b93782354 Node: Notes on Reproducibility3782851 Ref: library/random notes-on-reproducibility3783012 Ref: 17cc3783012 Node: Examples and Recipes3783710 Ref: library/random examples-and-recipes3783841 Ref: 17cd3783841 Ref: library/random random-examples3783841 Ref: b583783841 Ref: Examples and Recipes-Footnote-13789270 Ref: Examples and Recipes-Footnote-23789335 Ref: Examples and Recipes-Footnote-33789416 Ref: Examples and Recipes-Footnote-43789462 Ref: Examples and Recipes-Footnote-53789514 Ref: Examples and Recipes-Footnote-63789569 Ref: Examples and Recipes-Footnote-73789645 Ref: Examples and Recipes-Footnote-83789680 Ref: Examples and Recipes-Footnote-93789758 Node: statistics — Mathematical statistics functions3789793 Ref: library/statistics doc3789960 Ref: 17ce3789960 Ref: library/statistics module-statistics3789960 Ref: f53789960 Ref: library/statistics statistics-mathematical-statistics-functions3789960 Ref: 17cf3789960 Ref: statistics — Mathematical statistics functions-Footnote-13791254 Ref: statistics — Mathematical statistics functions-Footnote-23791323 Ref: statistics — Mathematical statistics functions-Footnote-33791349 Node: Averages and measures of central location3791380 Ref: library/statistics averages-and-measures-of-central-location3791533 Ref: 17d03791533 Node: Measures of spread3793056 Ref: library/statistics measures-of-spread3793234 Ref: 17d53793234 Node: Function details3793860 Ref: library/statistics function-details3794010 Ref: 17da3794010 Ref: library/statistics statistics mean3794212 Ref: 1993794212 Ref: library/statistics statistics fmean3795818 Ref: 2273795818 Ref: library/statistics statistics geometric_mean3796231 Ref: 2283796231 Ref: library/statistics statistics harmonic_mean3796918 Ref: 58f3796918 Ref: library/statistics statistics median3798388 Ref: 17d13798388 Ref: library/statistics statistics median_low3799383 Ref: 17d23799383 Ref: library/statistics statistics median_high3800024 Ref: 17d33800024 Ref: library/statistics statistics median_grouped3800662 Ref: 17d43800662 Ref: library/statistics statistics mode3802321 Ref: 2bb3802321 Ref: library/statistics statistics multimode3803487 Ref: 2293803487 Ref: library/statistics statistics pstdev3803906 Ref: 17d63803906 Ref: library/statistics statistics pvariance3804206 Ref: 17d73804206 Ref: library/statistics statistics stdev3806472 Ref: 17d83806472 Ref: library/statistics statistics variance3806764 Ref: 17d93806764 Ref: library/statistics statistics quantiles3809029 Ref: 22a3809029 Ref: Function details-Footnote-13811797 Ref: Function details-Footnote-23811892 Node: Exceptions<3>3811972 Ref: library/statistics exceptions3812122 Ref: 17dc3812122 Ref: library/statistics statistics StatisticsError3812193 Ref: 17db3812193 Node: NormalDist objects3812317 Ref: library/statistics normaldist-objects3812442 Ref: 17dd3812442 Ref: library/statistics statistics NormalDist3812830 Ref: 22b3812830 Ref: library/statistics statistics NormalDist mean3813095 Ref: 17de3813095 Ref: library/statistics statistics NormalDist median3813216 Ref: 17df3813216 Ref: library/statistics statistics NormalDist mode3813330 Ref: 17e03813330 Ref: library/statistics statistics NormalDist stdev3813430 Ref: 17e13813430 Ref: library/statistics statistics NormalDist variance3813555 Ref: 17e23813555 Ref: library/statistics statistics NormalDist from_samples3813721 Ref: 17e33813721 Ref: library/statistics statistics NormalDist samples3814329 Ref: 17e43814329 Ref: library/statistics statistics NormalDist pdf3814734 Ref: 17e53814734 Ref: library/statistics statistics NormalDist cdf3815335 Ref: 17e63815335 Ref: library/statistics statistics NormalDist inv_cdf3815578 Ref: 17e73815578 Ref: library/statistics statistics NormalDist overlap3816017 Ref: 17e83816017 Ref: library/statistics statistics NormalDist quantiles3816273 Ref: 17e93816273 Ref: NormalDist objects-Footnote-13817934 Ref: NormalDist objects-Footnote-23817998 Ref: NormalDist objects-Footnote-33818058 Ref: NormalDist objects-Footnote-43818112 Ref: NormalDist objects-Footnote-53818169 Ref: NormalDist objects-Footnote-63818223 Ref: NormalDist objects-Footnote-73818268 Ref: NormalDist objects-Footnote-83818324 Ref: NormalDist objects-Footnote-93818381 Ref: NormalDist objects-Footnote-103818428 Ref: NormalDist objects-Footnote-113818496 Ref: NormalDist objects-Footnote-123818568 Ref: NormalDist objects-Footnote-133818625 Ref: NormalDist objects-Footnote-143818717 Ref: NormalDist objects-Footnote-153818764 Node: NormalDist Examples and Recipes3818849 Ref: library/statistics normaldist-examples-and-recipes3818935 Ref: 17ea3818935 Ref: NormalDist Examples and Recipes-Footnote-13823505 Ref: NormalDist Examples and Recipes-Footnote-23823576 Ref: NormalDist Examples and Recipes-Footnote-33823623 Ref: NormalDist Examples and Recipes-Footnote-43823668 Ref: NormalDist Examples and Recipes-Footnote-53823725 Ref: NormalDist Examples and Recipes-Footnote-63823788 Ref: NormalDist Examples and Recipes-Footnote-73823869 Ref: NormalDist Examples and Recipes-Footnote-83823925 Node: Functional Programming Modules3823995 Ref: library/functional doc3824164 Ref: 17eb3824164 Ref: library/functional functional-programming-modules3824164 Ref: 17ec3824164 Node: itertools — Functions creating iterators for efficient looping3824647 Ref: library/itertools doc3824858 Ref: 17ed3824858 Ref: library/itertools itertools-functions-creating-iterators-for-efficient-looping3824858 Ref: 17ee3824858 Ref: library/itertools module-itertools3824858 Ref: a33824858 Node: Itertool functions3835248 Ref: library/itertools itertool-functions3835393 Ref: 17f73835393 Ref: library/itertools itertools-functions3835393 Ref: 17f83835393 Ref: library/itertools itertools accumulate3835640 Ref: 1dd3835640 Ref: library/itertools itertools chain3839158 Ref: 12ad3839158 Ref: library/itertools itertools chain from_iterable3839668 Ref: 17f13839668 Ref: library/itertools itertools combinations3840107 Ref: ca63840107 Ref: library/itertools itertools combinations_with_replacement3842081 Ref: c193842081 Ref: library/itertools itertools compress3844060 Ref: c1a3844060 Ref: library/itertools itertools count3844576 Ref: c1b3844576 Ref: library/itertools itertools cycle3845420 Ref: 17ef3845420 Ref: library/itertools itertools dropwhile3846140 Ref: 17f23846140 Ref: library/itertools itertools filterfalse3846841 Ref: 12963846841 Ref: library/itertools itertools groupby3847408 Ref: 17f33847408 Ref: library/itertools itertools islice3850144 Ref: 3a23850144 Ref: library/itertools itertools permutations3852232 Ref: 17f63852232 Ref: library/itertools itertools product3854678 Ref: ca73854678 Ref: library/itertools itertools repeat3856054 Ref: 17f03856054 Ref: library/itertools itertools starmap3856924 Ref: a283856924 Ref: library/itertools itertools takewhile3857610 Ref: 17f43857610 Ref: library/itertools itertools tee3858052 Ref: 17f53858052 Ref: library/itertools itertools zip_longest3859781 Ref: c313859781 Ref: Itertool functions-Footnote-13861257 Node: Itertools Recipes3861315 Ref: library/itertools id13861460 Ref: 17fa3861460 Ref: library/itertools itertools-recipes3861460 Ref: bf53861460 Ref: Itertools Recipes-Footnote-13870500 Node: functools — Higher-order functions and operations on callable objects3870549 Ref: library/functools doc3870813 Ref: 17fb3870813 Ref: library/functools functools-higher-order-functions-and-operations-on-callable-objects3870813 Ref: 17fc3870813 Ref: library/functools module-functools3870813 Ref: 853870813 Ref: library/functools functools cached_property3871356 Ref: 1c83871356 Ref: library/functools functools cmp_to_key3872661 Ref: b563872661 Ref: library/functools functools lru_cache3873705 Ref: 1c73873705 Ref: library/functools functools total_ordering3877807 Ref: 84b3877807 Ref: library/functools functools partial3879720 Ref: 7c83879720 Ref: library/functools functools partialmethod3881103 Ref: 29c3881103 Ref: library/functools functools reduce3882847 Ref: c6f3882847 Ref: library/functools functools singledispatch3884054 Ref: 38a3884054 Ref: library/functools functools singledispatchmethod3888257 Ref: 1c93888257 Ref: library/functools functools update_wrapper3889878 Ref: 95a3889878 Ref: library/functools functools wraps3892325 Ref: 86a3892325 Ref: functools — Higher-order functions and operations on callable objects-Footnote-13893623 Ref: functools — Higher-order functions and operations on callable objects-Footnote-23893691 Ref: functools — Higher-order functions and operations on callable objects-Footnote-33893755 Ref: functools — Higher-order functions and operations on callable objects-Footnote-43893810 Ref: functools — Higher-order functions and operations on callable objects-Footnote-53893868 Node: partial Objects3893911 Ref: library/functools id13894034 Ref: 17fe3894034 Ref: library/functools partial-objects3894034 Ref: 17fd3894034 Ref: library/functools functools partial func3894215 Ref: 17ff3894215 Ref: library/functools functools partial args3894404 Ref: 18003894404 Ref: library/functools functools partial keywords3894576 Ref: 18013894576 Node: operator — Standard operators as functions3895138 Ref: library/operator doc3895329 Ref: 18023895329 Ref: library/operator module-operator3895329 Ref: c23895329 Ref: library/operator operator-standard-operators-as-functions3895329 Ref: 18033895329 Ref: library/operator operator lt3896262 Ref: 18043896262 Ref: library/operator operator le3896295 Ref: 18053896295 Ref: library/operator operator eq3896328 Ref: 18063896328 Ref: library/operator operator ne3896361 Ref: 18073896361 Ref: library/operator operator ge3896394 Ref: 18083896394 Ref: library/operator operator gt3896427 Ref: 18093896427 Ref: library/operator operator __lt__3896460 Ref: 180a3896460 Ref: library/operator operator __le__3896497 Ref: 180b3896497 Ref: library/operator operator __eq__3896534 Ref: 180c3896534 Ref: library/operator operator __ne__3896571 Ref: 180d3896571 Ref: library/operator operator __ge__3896608 Ref: 180e3896608 Ref: library/operator operator __gt__3896645 Ref: 180f3896645 Ref: library/operator operator not_3897385 Ref: 18103897385 Ref: library/operator operator __not__3897419 Ref: 18113897419 Ref: library/operator operator truth3897740 Ref: 18123897740 Ref: library/operator operator is_3897930 Ref: 18133897930 Ref: library/operator operator is_not3898016 Ref: 18143898016 Ref: library/operator operator abs3898173 Ref: 18153898173 Ref: library/operator operator __abs__3898206 Ref: 18163898206 Ref: library/operator operator add3898286 Ref: 18173898286 Ref: library/operator operator __add__3898320 Ref: 18183898320 Ref: library/operator operator and_3898410 Ref: 18193898410 Ref: library/operator operator __and__3898445 Ref: 181a3898445 Ref: library/operator operator floordiv3898529 Ref: 181b3898529 Ref: library/operator operator __floordiv__3898568 Ref: 181c3898568 Ref: library/operator operator index3898639 Ref: 11233898639 Ref: library/operator operator __index__3898672 Ref: 181d3898672 Ref: library/operator operator inv3898788 Ref: 181e3898788 Ref: library/operator operator invert3898821 Ref: 181f3898821 Ref: library/operator operator __inv__3898857 Ref: 18203898857 Ref: library/operator operator __invert__3898894 Ref: 18213898894 Ref: library/operator operator lshift3899029 Ref: 18223899029 Ref: library/operator operator __lshift__3899066 Ref: 18233899066 Ref: library/operator operator mod3899146 Ref: 18243899146 Ref: library/operator operator __mod__3899180 Ref: 18253899180 Ref: library/operator operator mul3899245 Ref: 17f93899245 Ref: library/operator operator __mul__3899279 Ref: 18263899279 Ref: library/operator operator matmul3899369 Ref: 71d3899369 Ref: library/operator operator __matmul__3899406 Ref: 18273899406 Ref: library/operator operator neg3899500 Ref: 18283899500 Ref: library/operator operator __neg__3899533 Ref: 18293899533 Ref: library/operator operator or_3899612 Ref: 182a3899612 Ref: library/operator operator __or__3899646 Ref: 182b3899646 Ref: library/operator operator pos3899728 Ref: 182c3899728 Ref: library/operator operator __pos__3899761 Ref: 182d3899761 Ref: library/operator operator pow3899841 Ref: 182e3899841 Ref: library/operator operator __pow__3899875 Ref: 182f3899875 Ref: library/operator operator rshift3899966 Ref: 18303899966 Ref: library/operator operator __rshift__3900003 Ref: 18313900003 Ref: library/operator operator sub3900084 Ref: 18323900084 Ref: library/operator operator __sub__3900118 Ref: 18333900118 Ref: library/operator operator truediv3900183 Ref: 18343900183 Ref: library/operator operator __truediv__3900221 Ref: 18353900221 Ref: library/operator operator xor3900370 Ref: 18363900370 Ref: library/operator operator __xor__3900404 Ref: 18373900404 Ref: library/operator operator concat3900577 Ref: 18383900577 Ref: library/operator operator __concat__3900614 Ref: 18393900614 Ref: library/operator operator contains3900708 Ref: 183a3900708 Ref: library/operator operator __contains__3900747 Ref: 183b3900747 Ref: library/operator operator countOf3900876 Ref: 183c3900876 Ref: library/operator operator delitem3900969 Ref: 183d3900969 Ref: library/operator operator __delitem__3901007 Ref: 183e3901007 Ref: library/operator operator getitem3901094 Ref: 183f3901094 Ref: library/operator operator __getitem__3901132 Ref: 18403901132 Ref: library/operator operator indexOf3901219 Ref: 18413901219 Ref: library/operator operator setitem3901323 Ref: 18423901323 Ref: library/operator operator __setitem__3901364 Ref: 18433901364 Ref: library/operator operator length_hint3901458 Ref: 87d3901458 Ref: library/operator operator attrgetter3902030 Ref: 71b3902030 Ref: library/operator operator itemgetter3903331 Ref: 2613903331 Ref: library/operator operator methodcaller3905162 Ref: 71c3905162 Ref: operator — Standard operators as functions-Footnote-13905961 Node: Mapping Operators to Functions3906028 Ref: library/operator mapping-operators-to-functions3906166 Ref: 18443906166 Ref: library/operator operator-map3906166 Ref: 18453906166 Node: In-place Operators3913590 Ref: library/operator in-place-operators3913728 Ref: 18463913728 Ref: library/operator operator iadd3915036 Ref: 18483915036 Ref: library/operator operator __iadd__3915071 Ref: 18493915071 Ref: library/operator operator iand3915169 Ref: 184a3915169 Ref: library/operator operator __iand__3915204 Ref: 184b3915204 Ref: library/operator operator iconcat3915302 Ref: 184c3915302 Ref: library/operator operator __iconcat__3915340 Ref: 184d3915340 Ref: library/operator operator ifloordiv3915475 Ref: 184e3915475 Ref: library/operator operator __ifloordiv__3915515 Ref: 184f3915515 Ref: library/operator operator ilshift3915624 Ref: 18503915624 Ref: library/operator operator __ilshift__3915662 Ref: 18513915662 Ref: library/operator operator imod3915767 Ref: 18523915767 Ref: library/operator operator __imod__3915802 Ref: 18533915802 Ref: library/operator operator imul3915900 Ref: 18543915900 Ref: library/operator operator __imul__3915935 Ref: 18553915935 Ref: library/operator operator imatmul3916033 Ref: 71e3916033 Ref: library/operator operator __imatmul__3916071 Ref: 18563916071 Ref: library/operator operator ior3916201 Ref: 18573916201 Ref: library/operator operator __ior__3916235 Ref: 18583916235 Ref: library/operator operator ipow3916331 Ref: 18593916331 Ref: library/operator operator __ipow__3916366 Ref: 185a3916366 Ref: library/operator operator irshift3916465 Ref: 185b3916465 Ref: library/operator operator __irshift__3916503 Ref: 185c3916503 Ref: library/operator operator isub3916608 Ref: 185d3916608 Ref: library/operator operator __isub__3916643 Ref: 185e3916643 Ref: library/operator operator itruediv3916741 Ref: 185f3916741 Ref: library/operator operator __itruediv__3916780 Ref: 18603916780 Ref: library/operator operator ixor3916886 Ref: 18613916886 Ref: library/operator operator __ixor__3916921 Ref: 18623916921 Node: File and Directory Access3917019 Ref: library/filesys doc3917172 Ref: 18633917172 Ref: library/filesys file-and-directory-access3917172 Ref: 18643917172 Ref: library/filesys filesys3917172 Ref: 18653917172 Node: pathlib — Object-oriented filesystem paths3918074 Ref: library/pathlib doc3918230 Ref: 18663918230 Ref: library/pathlib module-pathlib3918230 Ref: c83918230 Ref: library/pathlib pathlib-object-oriented-filesystem-paths3918230 Ref: 18673918230 Ref: pathlib — Object-oriented filesystem paths-Footnote-13919929 Ref: pathlib — Object-oriented filesystem paths-Footnote-23919995 Node: Basic use3920044 Ref: library/pathlib basic-use3920153 Ref: 186c3920153 Node: Pure paths3921099 Ref: library/pathlib id13921231 Ref: 186d3921231 Ref: library/pathlib pure-paths3921231 Ref: 18683921231 Ref: library/pathlib pathlib PurePath3921446 Ref: 186e3921446 Ref: library/pathlib pathlib PurePosixPath3923630 Ref: 186f3923630 Ref: library/pathlib pathlib PureWindowsPath3923924 Ref: 186b3923924 Node: General properties3924517 Ref: library/pathlib general-properties3924603 Ref: 18713924603 Node: Operators<2>3925455 Ref: library/pathlib operators3925576 Ref: 18723925576 Node: Accessing individual parts3926786 Ref: library/pathlib accessing-individual-parts3926911 Ref: 18733926911 Ref: library/pathlib pathlib PurePath parts3927074 Ref: 18743927074 Node: Methods and properties3927472 Ref: library/pathlib methods-and-properties3927576 Ref: 18753927576 Ref: library/pathlib pathlib PurePath drive3927699 Ref: 18763927699 Ref: library/pathlib pathlib PurePath root3928117 Ref: 18773928117 Ref: library/pathlib pathlib PurePath anchor3928505 Ref: 18783928505 Ref: library/pathlib pathlib PurePath parents3928867 Ref: 18793928867 Ref: library/pathlib pathlib PurePath parent3929231 Ref: 187a3929231 Ref: library/pathlib pathlib PurePath name3930050 Ref: 187c3930050 Ref: library/pathlib pathlib PurePath suffix3930438 Ref: 187d3930438 Ref: library/pathlib pathlib PurePath suffixes3930731 Ref: 187e3930731 Ref: library/pathlib pathlib PurePath stem3931041 Ref: 187f3931041 Ref: library/pathlib pathlib PurePath as_posix3931335 Ref: 18803931335 Ref: library/pathlib pathlib PurePath as_uri3931600 Ref: 18813931600 Ref: library/pathlib pathlib PurePath is_absolute3931954 Ref: 18823931954 Ref: library/pathlib pathlib PurePath is_reserved3932546 Ref: 18833932546 Ref: library/pathlib pathlib PurePath joinpath3933018 Ref: 18843933018 Ref: library/pathlib pathlib PurePath match3933595 Ref: 18853933595 Ref: library/pathlib pathlib PurePath relative_to3934516 Ref: 18863934516 Ref: library/pathlib pathlib PurePath with_name3935178 Ref: 18873935178 Ref: library/pathlib pathlib PurePath with_suffix3935892 Ref: 18883935892 Node: Concrete paths3936562 Ref: library/pathlib concrete-paths3936725 Ref: 18693936725 Ref: library/pathlib id23936725 Ref: 18893936725 Ref: library/pathlib pathlib Path3936997 Ref: 2013936997 Ref: library/pathlib pathlib PosixPath3937381 Ref: 188a3937381 Ref: library/pathlib pathlib WindowsPath3937691 Ref: 186a3937691 Node: Methods<2>3938673 Ref: library/pathlib methods3938734 Ref: 188b3938734 Ref: library/pathlib pathlib Path cwd3939341 Ref: 188c3939341 Ref: library/pathlib pathlib Path home3939563 Ref: 72b3939563 Ref: library/pathlib pathlib Path stat3939842 Ref: 188e3939842 Ref: library/pathlib pathlib Path chmod3940190 Ref: 18903940190 Ref: library/pathlib pathlib Path exists3940453 Ref: 2023940453 Ref: library/pathlib pathlib Path expanduser3940925 Ref: 72a3940925 Ref: library/pathlib pathlib Path glob3941246 Ref: 18913941246 Ref: library/pathlib pathlib Path group3942151 Ref: 18923942151 Ref: library/pathlib pathlib Path is_dir3942325 Ref: 2033942325 Ref: library/pathlib pathlib Path is_file3942666 Ref: 2043942666 Ref: library/pathlib pathlib Path is_mount3943014 Ref: 2053943014 Ref: library/pathlib pathlib Path is_symlink3943518 Ref: 2063943518 Ref: library/pathlib pathlib Path is_socket3943767 Ref: 20a3943767 Ref: library/pathlib pathlib Path is_fifo3944115 Ref: 2093944115 Ref: library/pathlib pathlib Path is_block_device3944442 Ref: 2073944442 Ref: library/pathlib pathlib Path is_char_device3944798 Ref: 2083944798 Ref: library/pathlib pathlib Path iterdir3945161 Ref: 18933945161 Ref: library/pathlib pathlib Path lchmod3945914 Ref: 18943945914 Ref: library/pathlib pathlib Path lstat3946103 Ref: 18953946103 Ref: library/pathlib pathlib Path mkdir3946289 Ref: 7293946289 Ref: library/pathlib pathlib Path open3947356 Ref: 18963947356 Ref: library/pathlib pathlib Path owner3947709 Ref: 18973947709 Ref: library/pathlib pathlib Path read_bytes3947882 Ref: 72f3947882 Ref: library/pathlib pathlib Path read_text3948191 Ref: 72d3948191 Ref: library/pathlib pathlib Path rename3948624 Ref: 18983948624 Ref: library/pathlib pathlib Path replace3949447 Ref: 18993949447 Ref: library/pathlib pathlib Path resolve3949956 Ref: 187b3949956 Ref: library/pathlib pathlib Path rglob3950888 Ref: 189a3950888 Ref: library/pathlib pathlib Path rmdir3951287 Ref: 189b3951287 Ref: library/pathlib pathlib Path samefile3951373 Ref: 7283951373 Ref: library/pathlib pathlib Path symlink_to3951924 Ref: 189c3951924 Ref: library/pathlib pathlib Path touch3952579 Ref: 189d3952579 Ref: library/pathlib pathlib Path unlink3952997 Ref: 189e3952997 Ref: library/pathlib pathlib Path link_to3953492 Ref: 20b3953492 Ref: library/pathlib pathlib Path write_bytes3953613 Ref: 72e3953613 Ref: library/pathlib pathlib Path write_text3953994 Ref: 72c3953994 Node: Correspondence to tools in the os module3954468 Ref: library/pathlib correspondence-to-tools-in-the-os-module3954612 Ref: 189f3954612 Node: os path — Common pathname manipulations3958916 Ref: library/os path doc3959141 Ref: 18a53959141 Ref: library/os path module-os path3959141 Ref: c53959141 Ref: library/os path os-path-common-pathname-manipulations3959141 Ref: 18a63959141 Ref: library/os path os path abspath3961537 Ref: cb03961537 Ref: library/os path os path basename3961863 Ref: 18a23961863 Ref: library/os path os path commonpath3962374 Ref: 7253962374 Ref: library/os path os path commonprefix3962892 Ref: 7263962892 Ref: library/os path os path dirname3963540 Ref: 18a33963540 Ref: library/os path os path exists3963812 Ref: 1f63963812 Ref: library/os path os path lexists3964400 Ref: 1f73964400 Ref: library/os path os path expanduser3964706 Ref: 1fe3964706 Ref: library/os path os path expandvars3965729 Ref: d443965729 Ref: library/os path os path getatime3966221 Ref: 18a83966221 Ref: library/os path os path getmtime3966522 Ref: 18a93966522 Ref: library/os path os path getctime3966898 Ref: 18aa3966898 Ref: library/os path os path getsize3967389 Ref: 18ab3967389 Ref: library/os path os path isabs3967619 Ref: 18a13967619 Ref: library/os path os path isfile3967928 Ref: 1f93967928 Ref: library/os path os path isdir3968233 Ref: 1f83968233 Ref: library/os path os path islink3968534 Ref: 1f43968534 Ref: library/os path os path ismount3968838 Ref: 1fa3968838 Ref: library/os path os path join3969726 Ref: 18703969726 Ref: library/os path os path normcase3970782 Ref: 18ac3970782 Ref: library/os path os path normpath3971121 Ref: caf3971121 Ref: library/os path os path realpath3971626 Ref: 1ff3971626 Ref: library/os path os path relpath3972179 Ref: 18a03972179 Ref: library/os path os path samefile3972647 Ref: 8823972647 Ref: library/os path os path sameopenfile3973208 Ref: 18ae3973208 Ref: library/os path os path samestat3973517 Ref: 8813973517 Ref: library/os path os path split3974069 Ref: 18a73974069 Ref: library/os path os path splitdrive3974858 Ref: 47d3974858 Ref: library/os path os path splitext3975755 Ref: 18a43975755 Ref: library/os path os path supports_unicode_filenames3976153 Ref: ded3976153 Ref: os path — Common pathname manipulations-Footnote-13976361 Ref: os path — Common pathname manipulations-Footnote-23976429 Node: fileinput — Iterate over lines from multiple input streams3976494 Ref: library/fileinput doc3976709 Ref: 18af3976709 Ref: library/fileinput fileinput-iterate-over-lines-from-multiple-input-streams3976709 Ref: 18b03976709 Ref: library/fileinput module-fileinput3976709 Ref: 803976709 Ref: library/fileinput fileinput input3978873 Ref: 2ad3978873 Ref: library/fileinput fileinput filename3979975 Ref: 18b13979975 Ref: library/fileinput fileinput fileno3980131 Ref: 18b23980131 Ref: library/fileinput fileinput lineno3980330 Ref: 18b33980330 Ref: library/fileinput fileinput filelineno3980603 Ref: 18b43980603 Ref: library/fileinput fileinput isfirstline3980869 Ref: 18b53980869 Ref: library/fileinput fileinput isstdin3981021 Ref: 18b63981021 Ref: library/fileinput fileinput nextfile3981164 Ref: 18b73981164 Ref: library/fileinput fileinput close3981704 Ref: 18b83981704 Ref: library/fileinput fileinput FileInput3981875 Ref: 27f3981875 Ref: library/fileinput fileinput hook_compressed3984489 Ref: 18ba3984489 Ref: library/fileinput fileinput hook_encoded3984986 Ref: 54a3984986 Ref: fileinput — Iterate over lines from multiple input streams-Footnote-13985406 Node: stat — Interpreting stat results3985474 Ref: library/stat doc3985690 Ref: 18bb3985690 Ref: library/stat module-stat3985690 Ref: f43985690 Ref: library/stat stat-interpreting-stat-results3985690 Ref: 18bc3985690 Ref: library/stat stat S_ISDIR3986368 Ref: 18bd3986368 Ref: library/stat stat S_ISCHR3986458 Ref: 18be3986458 Ref: library/stat stat S_ISBLK3986573 Ref: 18bf3986573 Ref: library/stat stat S_ISREG3986679 Ref: 18c03986679 Ref: library/stat stat S_ISFIFO3986772 Ref: 18c13986772 Ref: library/stat stat S_ISLNK3986871 Ref: 18c23986871 Ref: library/stat stat S_ISSOCK3986965 Ref: 18c33986965 Ref: library/stat stat S_ISDOOR3987053 Ref: 18c43987053 Ref: library/stat stat S_ISPORT3987165 Ref: 18c53987165 Ref: library/stat stat S_ISWHT3987284 Ref: 18c63987284 Ref: library/stat stat S_IMODE3987489 Ref: 18c73987489 Ref: library/stat stat S_IFMT3987756 Ref: 18c83987756 Ref: library/stat stat filemode3989286 Ref: a9d3989286 Ref: library/stat stat ST_MODE3989697 Ref: 8d33989697 Ref: library/stat stat ST_INO3989750 Ref: 18c93989750 Ref: library/stat stat ST_DEV3989793 Ref: 18ca3989793 Ref: library/stat stat ST_NLINK3989847 Ref: 18cb3989847 Ref: library/stat stat ST_UID3989908 Ref: 18cc3989908 Ref: library/stat stat ST_GID3989959 Ref: 18cd3989959 Ref: library/stat stat ST_SIZE3990011 Ref: 18ce3990011 Ref: library/stat stat ST_ATIME3990123 Ref: 18cf3990123 Ref: library/stat stat ST_MTIME3990175 Ref: 18d03990175 Ref: library/stat stat ST_CTIME3990233 Ref: 18d13990233 Ref: library/stat stat S_IFSOCK3991275 Ref: 18d23991275 Ref: library/stat stat S_IFLNK3991314 Ref: 18d33991314 Ref: library/stat stat S_IFREG3991359 Ref: 18d43991359 Ref: library/stat stat S_IFBLK3991403 Ref: 18d53991403 Ref: library/stat stat S_IFDIR3991447 Ref: 18d63991447 Ref: library/stat stat S_IFCHR3991488 Ref: 18d73991488 Ref: library/stat stat S_IFIFO3991536 Ref: 18d83991536 Ref: library/stat stat S_IFDOOR3991572 Ref: 8d43991572 Ref: library/stat stat S_IFPORT3991635 Ref: 8d53991635 Ref: library/stat stat S_IFWHT3991704 Ref: 8d63991704 Ref: library/stat stat S_ISUID3992022 Ref: 18d93992022 Ref: library/stat stat S_ISGID3992065 Ref: 18da3992065 Ref: library/stat stat S_ISVTX3992642 Ref: 18dd3992642 Ref: library/stat stat S_IRWXU3992891 Ref: 18de3992891 Ref: library/stat stat S_IRUSR3992954 Ref: 18df3992954 Ref: library/stat stat S_IWUSR3993011 Ref: 18e03993011 Ref: library/stat stat S_IXUSR3993069 Ref: 18e13993069 Ref: library/stat stat S_IRWXG3993129 Ref: 18e23993129 Ref: library/stat stat S_IRGRP3993187 Ref: 18e33993187 Ref: library/stat stat S_IWGRP3993244 Ref: 18e43993244 Ref: library/stat stat S_IXGRP3993302 Ref: 18db3993302 Ref: library/stat stat S_IRWXO3993362 Ref: 18e53993362 Ref: library/stat stat S_IROTH3993440 Ref: 18e63993440 Ref: library/stat stat S_IWOTH3993499 Ref: 18e73993499 Ref: library/stat stat S_IXOTH3993559 Ref: 18e83993559 Ref: library/stat stat S_ENFMT3993621 Ref: 18dc3993621 Ref: library/stat stat S_IREAD3993854 Ref: 18e93993854 Ref: library/stat stat S_IWRITE3993925 Ref: 18ea3993925 Ref: library/stat stat S_IEXEC3993997 Ref: 18eb3993997 Ref: library/stat stat UF_NODUMP3994154 Ref: 18ec3994154 Ref: library/stat stat UF_IMMUTABLE3994208 Ref: 18ed3994208 Ref: library/stat stat UF_APPEND3994272 Ref: 18ee3994272 Ref: library/stat stat UF_OPAQUE3994338 Ref: 18ef3994338 Ref: library/stat stat UF_NOUNLINK3994429 Ref: 18f03994429 Ref: library/stat stat UF_COMPRESSED3994503 Ref: 18f13994503 Ref: library/stat stat UF_HIDDEN3994587 Ref: 18f23994587 Ref: library/stat stat SF_ARCHIVED3994679 Ref: 18f33994679 Ref: library/stat stat SF_IMMUTABLE3994739 Ref: 18f43994739 Ref: library/stat stat SF_APPEND3994803 Ref: 18f53994803 Ref: library/stat stat SF_NOUNLINK3994869 Ref: 18f63994869 Ref: library/stat stat SF_SNAPSHOT3994943 Ref: 18f73994943 Ref: library/stat stat FILE_ATTRIBUTE_ARCHIVE3995340 Ref: 18f83995340 Ref: library/stat stat FILE_ATTRIBUTE_COMPRESSED3995378 Ref: 18f93995378 Ref: library/stat stat FILE_ATTRIBUTE_DEVICE3995419 Ref: 18fa3995419 Ref: library/stat stat FILE_ATTRIBUTE_DIRECTORY3995456 Ref: 18fb3995456 Ref: library/stat stat FILE_ATTRIBUTE_ENCRYPTED3995496 Ref: 18fc3995496 Ref: library/stat stat FILE_ATTRIBUTE_HIDDEN3995536 Ref: 18fd3995536 Ref: library/stat stat FILE_ATTRIBUTE_INTEGRITY_STREAM3995573 Ref: 18fe3995573 Ref: library/stat stat FILE_ATTRIBUTE_NORMAL3995620 Ref: 18ff3995620 Ref: library/stat stat FILE_ATTRIBUTE_NOT_CONTENT_INDEXED3995657 Ref: 19003995657 Ref: library/stat stat FILE_ATTRIBUTE_NO_SCRUB_DATA3995707 Ref: 19013995707 Ref: library/stat stat FILE_ATTRIBUTE_OFFLINE3995751 Ref: 19023995751 Ref: library/stat stat FILE_ATTRIBUTE_READONLY3995789 Ref: 19033995789 Ref: library/stat stat FILE_ATTRIBUTE_REPARSE_POINT3995828 Ref: 19043995828 Ref: library/stat stat FILE_ATTRIBUTE_SPARSE_FILE3995872 Ref: 19053995872 Ref: library/stat stat FILE_ATTRIBUTE_SYSTEM3995914 Ref: 19063995914 Ref: library/stat stat FILE_ATTRIBUTE_TEMPORARY3995951 Ref: 19073995951 Ref: library/stat stat FILE_ATTRIBUTE_VIRTUAL3995991 Ref: 19083995991 Ref: library/stat stat IO_REPARSE_TAG_SYMLINK3996261 Ref: 19093996261 Ref: library/stat stat IO_REPARSE_TAG_MOUNT_POINT3996299 Ref: 190a3996299 Ref: library/stat stat IO_REPARSE_TAG_APPEXECLINK3996341 Ref: 190b3996341 Ref: stat — Interpreting stat results-Footnote-13996446 Ref: stat — Interpreting stat results-Footnote-23996509 Node: filecmp — File and Directory Comparisons3996589 Ref: library/filecmp doc3996798 Ref: 190c3996798 Ref: library/filecmp filecmp-file-and-directory-comparisons3996798 Ref: 190d3996798 Ref: library/filecmp module-filecmp3996798 Ref: 7f3996798 Ref: library/filecmp filecmp cmp3997267 Ref: 190e3997267 Ref: library/filecmp filecmp cmpfiles3997954 Ref: 190f3997954 Ref: library/filecmp filecmp clear_cache3998899 Ref: 8473998899 Ref: filecmp — File and Directory Comparisons-Footnote-13999214 Node: The dircmp class3999280 Ref: library/filecmp dircmp-objects3999375 Ref: 19103999375 Ref: library/filecmp the-dircmp-class3999375 Ref: 19113999375 Ref: library/filecmp filecmp dircmp3999436 Ref: 8493999436 Ref: library/filecmp filecmp dircmp report3999971 Ref: 19123999971 Ref: library/filecmp filecmp dircmp report_partial_closure4000088 Ref: 19134000088 Ref: library/filecmp filecmp dircmp report_full_closure4000229 Ref: 19144000229 Ref: library/filecmp filecmp dircmp left4000748 Ref: 19154000748 Ref: library/filecmp filecmp dircmp right4000804 Ref: 19164000804 Ref: library/filecmp filecmp dircmp left_list4000861 Ref: 19174000861 Ref: library/filecmp filecmp dircmp right_list4000979 Ref: 19184000979 Ref: library/filecmp filecmp dircmp common4001098 Ref: 19194001098 Ref: library/filecmp filecmp dircmp left_only4001183 Ref: 191a4001183 Ref: library/filecmp filecmp dircmp right_only4001263 Ref: 191b4001263 Ref: library/filecmp filecmp dircmp common_dirs4001344 Ref: 191c4001344 Ref: library/filecmp filecmp dircmp common_files4001424 Ref: 191d4001424 Ref: library/filecmp filecmp dircmp common_funny4001496 Ref: 191e4001496 Ref: library/filecmp filecmp dircmp same_files4001699 Ref: 191f4001699 Ref: library/filecmp filecmp dircmp diff_files4001845 Ref: 19204001845 Ref: library/filecmp filecmp dircmp funny_files4002010 Ref: 19214002010 Ref: library/filecmp filecmp dircmp subdirs4002128 Ref: 19224002128 Ref: library/filecmp filecmp DEFAULT_IGNORES4002264 Ref: 8484002264 Node: tempfile — Generate temporary files and directories4002948 Ref: library/tempfile doc4003169 Ref: 19234003169 Ref: library/tempfile module-tempfile4003169 Ref: 1034003169 Ref: library/tempfile tempfile-generate-temporary-files-and-directories4003169 Ref: 19244003169 Ref: library/tempfile tempfile TemporaryFile4004324 Ref: 19254004324 Ref: library/tempfile tempfile NamedTemporaryFile4006377 Ref: d494006377 Ref: library/tempfile tempfile SpooledTemporaryFile4007546 Ref: aa64007546 Ref: library/tempfile tempfile TemporaryDirectory4008777 Ref: bc84008777 Ref: library/tempfile tempfile mkstemp4009761 Ref: 19264009761 Ref: library/tempfile tempfile mkdtemp4012643 Ref: 19274012643 Ref: library/tempfile tempfile gettempdir4013757 Ref: 192d4013757 Ref: library/tempfile tempfile gettempdirb4014766 Ref: 192f4014766 Ref: library/tempfile tempfile gettempprefix4014905 Ref: 192b4014905 Ref: library/tempfile tempfile gettempprefixb4015064 Ref: 192c4015064 Ref: library/tempfile tempfile tempdir4015564 Ref: 192e4015564 Ref: tempfile — Generate temporary files and directories-Footnote-14016090 Node: Examples<3>4016157 Ref: library/tempfile examples4016301 Ref: 19304016301 Ref: library/tempfile tempfile-examples4016301 Ref: 19294016301 Node: Deprecated functions and variables4017219 Ref: library/tempfile deprecated-functions-and-variables4017363 Ref: 19314017363 Ref: library/tempfile tempfile mktemp4017993 Ref: 19324017993 Node: glob — Unix style pathname pattern expansion4019126 Ref: library/glob doc4019347 Ref: 19334019347 Ref: library/glob glob-unix-style-pathname-pattern-expansion4019347 Ref: 19344019347 Ref: library/glob module-glob4019347 Ref: 8a4019347 Ref: library/glob glob glob4020460 Ref: 5c64020460 Ref: library/glob glob iglob4021729 Ref: 5c74021729 Ref: library/glob glob escape4022041 Ref: 8504022041 Ref: glob — Unix style pathname pattern expansion-Footnote-14023495 Node: fnmatch — Unix filename pattern matching4023558 Ref: library/fnmatch doc4023767 Ref: 19384023767 Ref: library/fnmatch fnmatch-unix-filename-pattern-matching4023767 Ref: 19394023767 Ref: library/fnmatch module-fnmatch4023767 Ref: 814023767 Ref: library/fnmatch fnmatch fnmatch4025102 Ref: 19354025102 Ref: library/fnmatch fnmatch fnmatchcase4025789 Ref: 193b4025789 Ref: library/fnmatch fnmatch filter4026036 Ref: 193a4026036 Ref: library/fnmatch fnmatch translate4026284 Ref: 193c4026284 Ref: fnmatch — Unix filename pattern matching-Footnote-14026864 Node: linecache — Random access to text lines4026930 Ref: library/linecache doc4027130 Ref: 193d4027130 Ref: library/linecache linecache-random-access-to-text-lines4027130 Ref: 193e4027130 Ref: library/linecache module-linecache4027130 Ref: a84027130 Ref: library/linecache linecache getline4027960 Ref: 7094027960 Ref: library/linecache linecache clearcache4028729 Ref: 19414028729 Ref: library/linecache linecache checkcache4028898 Ref: 19424028898 Ref: library/linecache linecache lazycache4029176 Ref: 7084029176 Ref: linecache — Random access to text lines-Footnote-14029723 Ref: linecache — Random access to text lines-Footnote-24029791 Node: shutil — High-level file operations4029840 Ref: library/shutil doc4029989 Ref: 19434029989 Ref: library/shutil module-shutil4029989 Ref: e94029989 Ref: library/shutil shutil-high-level-file-operations4029989 Ref: 19444029989 Ref: shutil — High-level file operations-Footnote-14031092 Node: Directory and files operations4031157 Ref: library/shutil directory-and-files-operations4031290 Ref: 19454031290 Ref: library/shutil file-operations4031290 Ref: 19464031290 Ref: library/shutil shutil copyfileobj4031373 Ref: 25d4031373 Ref: library/shutil shutil copyfile4031956 Ref: 2584031956 Ref: library/shutil shutil SameFileError4033556 Ref: 8b34033556 Ref: library/shutil shutil copymode4033726 Ref: 19474033726 Ref: library/shutil shutil copystat4034620 Ref: a774034620 Ref: library/shutil shutil copy4036726 Ref: 2594036726 Ref: library/shutil shutil copy24038157 Ref: 25a4038157 Ref: library/shutil shutil ignore_patterns4039670 Ref: 19494039670 Ref: library/shutil shutil copytree4039972 Ref: 21a4039972 Ref: library/shutil shutil rmtree4043122 Ref: 21c4043122 Ref: library/shutil shutil rmtree avoids_symlink_attacks4045046 Ref: 194a4045046 Ref: library/shutil shutil move4045386 Ref: 25b4045386 Ref: library/shutil shutil disk_usage4047224 Ref: a754047224 Ref: library/shutil shutil chown4047671 Ref: a764047671 Ref: library/shutil shutil which4048156 Ref: 194b4048156 Ref: library/shutil shutil Error4049483 Ref: 8b24049483 Node: Platform-dependent efficient copy operations4049819 Ref: library/shutil platform-dependent-efficient-copy-operations4049955 Ref: 194d4049955 Ref: library/shutil shutil-platform-dependent-efficient-copy-operations4049955 Ref: 25e4049955 Ref: Platform-dependent efficient copy operations-Footnote-14051079 Ref: Platform-dependent efficient copy operations-Footnote-24051122 Node: copytree example4051170 Ref: library/shutil copytree-example4051329 Ref: 194e4051329 Ref: library/shutil shutil-copytree-example4051329 Ref: 194f4051329 Node: rmtree example4053407 Ref: library/shutil rmtree-example4053513 Ref: 19504053513 Ref: library/shutil shutil-rmtree-example4053513 Ref: 19514053513 Node: Archiving operations4054060 Ref: library/shutil archiving-operations4054242 Ref: b964054242 Ref: library/shutil id14054242 Ref: 19524054242 Ref: library/shutil shutil make_archive4054550 Ref: 21b4054550 Ref: library/shutil shutil get_archive_formats4056523 Ref: 19544056523 Ref: library/shutil shutil register_archive_format4057365 Ref: 19554057365 Ref: library/shutil shutil unregister_archive_format4058211 Ref: 19564058211 Ref: library/shutil shutil unpack_archive4058346 Ref: b974058346 Ref: library/shutil shutil register_unpack_format4059306 Ref: 19574059306 Ref: library/shutil shutil unregister_unpack_format4060069 Ref: 19594060069 Ref: library/shutil shutil get_unpack_formats4060193 Ref: 19584060193 Ref: Archiving operations-Footnote-14061146 Node: Archiving example4061195 Ref: library/shutil archiving-example4061309 Ref: 195a4061309 Ref: library/shutil shutil-archiving-example4061309 Ref: 195b4061309 Node: Archiving example with base_dir4062402 Ref: library/shutil archiving-example-with-base-dir4062516 Ref: 195c4062516 Ref: library/shutil shutil-archiving-example-with-basedir4062516 Ref: 19534062516 Node: Querying the size of the output terminal4063620 Ref: library/shutil querying-the-size-of-the-output-terminal4063763 Ref: 195d4063763 Ref: library/shutil shutil get_terminal_size4063866 Ref: a4a4063866 Ref: Querying the size of the output terminal-Footnote-14065393 Node: Data Persistence4065475 Ref: library/persistence doc4065628 Ref: 19604065628 Ref: library/persistence data-persistence4065628 Ref: 19614065628 Ref: library/persistence other-environment-variables4065628 Ref: 19624065628 Ref: library/persistence persistence4065628 Ref: 19634065628 Node: pickle — Python object serialization4066459 Ref: library/pickle doc4066604 Ref: 19644066604 Ref: library/pickle module-pickle4066604 Ref: ca4066604 Ref: library/pickle pickle-python-object-serialization4066604 Ref: 19654066604 Ref: pickle — Python object serialization-Footnote-14068439 Ref: pickle — Python object serialization-Footnote-24068504 Node: Relationship to other Python modules4068572 Ref: library/pickle relationship-to-other-python-modules4068710 Ref: 19684068710 Node: Comparison with marshal4068866 Ref: library/pickle comparison-with-marshal4068991 Ref: 19694068991 Node: Comparison with json4071219 Ref: library/pickle comparison-with-json4071344 Ref: 19674071344 Ref: library/pickle id24071344 Ref: 196a4071344 Ref: Comparison with json-Footnote-14072509 Node: Data stream format4072533 Ref: library/pickle data-stream-format4072696 Ref: 196c4072696 Ref: library/pickle pickle-protocols4072696 Ref: 56e4072696 Ref: Data stream format-Footnote-14075666 Ref: Data stream format-Footnote-24075715 Ref: Data stream format-Footnote-34075764 Node: Module Interface4075813 Ref: library/pickle module-interface4075974 Ref: 196f4075974 Ref: library/pickle pickle HIGHEST_PROTOCOL4076426 Ref: e004076426 Ref: library/pickle pickle DEFAULT_PROTOCOL4076698 Ref: 19724076698 Ref: library/pickle pickle dump4077206 Ref: 19714077206 Ref: library/pickle pickle dumps4077704 Ref: dff4077704 Ref: library/pickle pickle load4078141 Ref: 5c24078141 Ref: library/pickle pickle loads4078889 Ref: 5c34078889 Ref: library/pickle pickle PickleError4079622 Ref: 19734079622 Ref: library/pickle pickle PicklingError4079756 Ref: 19744079756 Ref: library/pickle pickle UnpicklingError4080035 Ref: 19764080035 Ref: library/pickle pickle Pickler4080544 Ref: 20d4080544 Ref: library/pickle pickle Pickler dump4082098 Ref: 19794082098 Ref: library/pickle pickle Pickler persistent_id4082240 Ref: 197a4082240 Ref: library/pickle pickle Pickler dispatch_table4082916 Ref: a694082916 Ref: library/pickle pickle Pickler reducer_override4084080 Ref: 20e4084080 Ref: library/pickle pickle Pickler fast4084695 Ref: 19804084695 Ref: library/pickle pickle Unpickler4085180 Ref: 19704085180 Ref: library/pickle pickle Unpickler load4087284 Ref: 19824087284 Ref: library/pickle pickle Unpickler persistent_load4087579 Ref: 197b4087579 Ref: library/pickle pickle Unpickler find_class4088026 Ref: 19834088026 Ref: library/pickle pickle PickleBuffer4088705 Ref: 19774088705 Ref: library/pickle pickle PickleBuffer raw4089323 Ref: 19854089323 Ref: library/pickle pickle PickleBuffer release4089666 Ref: 19864089666 Node: What can be pickled and unpickled?4089782 Ref: library/pickle pickle-picklable4089949 Ref: 19754089949 Ref: library/pickle what-can-be-pickled-and-unpickled4089949 Ref: 19874089949 Ref: What can be pickled and unpickled?-Footnote-14092677 Ref: What can be pickled and unpickled?-Footnote-24092813 Node: Pickling Class Instances4092953 Ref: library/pickle pickle-inst4093158 Ref: 196b4093158 Ref: library/pickle pickling-class-instances4093158 Ref: 19884093158 Ref: library/pickle object __getnewargs_ex__4094090 Ref: 19894094090 Ref: library/pickle object __getnewargs__4094922 Ref: 6ae4094922 Ref: library/pickle object __getstate__4095488 Ref: e014095488 Ref: library/pickle object __setstate__4095927 Ref: 19c4095927 Ref: library/pickle object __reduce__4097766 Ref: 19b4097766 Ref: library/pickle object __reduce_ex__4100631 Ref: 16ac4100631 Ref: Pickling Class Instances-Footnote-14101292 Node: Persistence of External Objects4101391 Ref: library/pickle persistence-of-external-objects4101507 Ref: 198b4101507 Ref: library/pickle pickle-persistent4101507 Ref: 197c4101507 Ref: Persistence of External Objects-Footnote-14106175 Node: Dispatch Tables4106439 Ref: library/pickle dispatch-tables4106589 Ref: 198c4106589 Ref: library/pickle pickle-dispatch4106589 Ref: 197e4106589 Node: Handling Stateful Objects4107816 Ref: library/pickle handling-stateful-objects4107926 Ref: 198d4107926 Ref: library/pickle pickle-state4107926 Ref: 198a4107926 Node: Custom Reduction for Types Functions and Other Objects4110213 Ref: library/pickle custom-reduction-for-types-functions-and-other-objects4110403 Ref: 198e4110403 Ref: library/pickle reducer-override4110403 Ref: 197f4110403 Node: Out-of-band Buffers4112495 Ref: library/pickle out-of-band-buffers4112680 Ref: 198f4112680 Ref: library/pickle pickle-oob4112680 Ref: 19784112680 Node: Provider API4113528 Ref: library/pickle provider-api4113617 Ref: 19904113617 Node: Consumer API4114224 Ref: library/pickle consumer-api4114332 Ref: 19914114332 Node: Example<4>4115634 Ref: library/pickle example4115721 Ref: 19924115721 Ref: Example<4>-Footnote-14118105 Node: Restricting Globals4118154 Ref: library/pickle pickle-restrict4118299 Ref: 19844118299 Ref: library/pickle restricting-globals4118299 Ref: 19934118299 Node: Performance<2>4121075 Ref: library/pickle performance4121212 Ref: 19944121212 Node: Examples<4>4121488 Ref: library/pickle examples4121597 Ref: 19954121597 Ref: library/pickle pickle-example4121597 Ref: 19964121597 Node: copyreg — Register pickle support functions4122815 Ref: library/copyreg doc4123005 Ref: 19974123005 Ref: library/copyreg copyreg-register-pickle-support-functions4123005 Ref: 19984123005 Ref: library/copyreg module-copyreg4123005 Ref: 274123005 Ref: library/copyreg copyreg constructor4123597 Ref: 19994123597 Ref: library/copyreg copyreg pickle4123800 Ref: 197d4123800 Ref: copyreg — Register pickle support functions-Footnote-14124753 Node: Example<5>4124819 Ref: library/copyreg example4124911 Ref: 199a4124911 Node: shelve — Python object persistence4125463 Ref: library/shelve doc4125663 Ref: 199b4125663 Ref: library/shelve module-shelve4125663 Ref: e74125663 Ref: library/shelve shelve-python-object-persistence4125663 Ref: 199c4125663 Ref: library/shelve shelve open4126248 Ref: 199d4126248 Ref: library/shelve shelve Shelf sync4128464 Ref: 199f4128464 Ref: library/shelve shelve Shelf close4128785 Ref: 19a04128785 Ref: shelve — Python object persistence-Footnote-14129167 Ref: shelve — Python object persistence-Footnote-24129232 Node: Restrictions4129285 Ref: library/shelve restrictions4129389 Ref: 19a14129389 Ref: library/shelve shelve Shelf4130414 Ref: 8b04130414 Ref: library/shelve shelve BsdDbShelf4131650 Ref: 19a24131650 Ref: library/shelve shelve DbfilenameShelf4132356 Ref: 19a34132356 Ref: Restrictions-Footnote-14132971 Node: Example<6>4133024 Ref: library/shelve example4133128 Ref: 19a44133128 Ref: library/shelve shelve-example4133128 Ref: 199e4133128 Node: marshal — Internal Python object serialization4134807 Ref: library/marshal doc4135004 Ref: 19a54135004 Ref: library/marshal marshal-internal-python-object-serialization4135004 Ref: 19a64135004 Ref: library/marshal module-marshal4135004 Ref: b04135004 Ref: library/marshal marshal dump4137411 Ref: 19a74137411 Ref: library/marshal marshal load4137959 Ref: 19a84137959 Ref: library/marshal marshal dumps4138511 Ref: 79c4138511 Ref: library/marshal marshal loads4138911 Ref: 19a94138911 Ref: library/marshal marshal version4139212 Ref: 19aa4139212 Ref: marshal — Internal Python object serialization-Footnote-14139566 Node: dbm — Interfaces to Unix “databases”4139950 Ref: library/dbm doc4140164 Ref: 19ab4140164 Ref: library/dbm dbm-interfaces-to-unix-databases4140164 Ref: 19ac4140164 Ref: library/dbm module-dbm4140164 Ref: 324140164 Ref: library/dbm dbm error4140674 Ref: 19ad4140674 Ref: library/dbm dbm whichdb4140946 Ref: 19ae4140946 Ref: library/dbm dbm open4141509 Ref: 8304141509 Ref: dbm — Interfaces to Unix “databases”-Footnote-14145152 Ref: dbm — Interfaces to Unix “databases”-Footnote-24145223 Node: dbm gnu — GNU’s reinterpretation of dbm4145276 Ref: library/dbm dbm-gnu-gnu-s-reinterpretation-of-dbm4145443 Ref: 19af4145443 Ref: library/dbm module-dbm gnu4145443 Ref: 344145443 Ref: library/dbm dbm gnu error4146259 Ref: 2c54146259 Ref: library/dbm dbm gnu open4146463 Ref: 19b04146463 Ref: library/dbm dbm gnu gdbm firstkey4148541 Ref: 19b14148541 Ref: library/dbm dbm gnu gdbm nextkey4148885 Ref: 19b24148885 Ref: library/dbm dbm gnu gdbm reorganize4149266 Ref: 19b34149266 Ref: library/dbm dbm gnu gdbm sync4149709 Ref: 19b44149709 Ref: library/dbm dbm gnu gdbm close4149874 Ref: 19b54149874 Ref: dbm gnu — GNU’s reinterpretation of dbm-Footnote-14149984 Node: dbm ndbm — Interface based on ndbm4150050 Ref: library/dbm dbm-ndbm-interface-based-on-ndbm4150266 Ref: 19b64150266 Ref: library/dbm module-dbm ndbm4150266 Ref: 354150266 Ref: library/dbm dbm ndbm error4151022 Ref: 2c64151022 Ref: library/dbm dbm ndbm library4151228 Ref: 19b74151228 Ref: library/dbm dbm ndbm open4151314 Ref: 19b84151314 Ref: library/dbm dbm ndbm ndbm close4152599 Ref: 19b94152599 Ref: dbm ndbm — Interface based on ndbm-Footnote-14152709 Node: dbm dumb — Portable DBM implementation4152776 Ref: library/dbm dbm-dumb-portable-dbm-implementation4152940 Ref: 19ba4152940 Ref: library/dbm module-dbm dumb4152940 Ref: 334152940 Ref: library/dbm dbm dumb error4153765 Ref: 2c44153765 Ref: library/dbm dbm dumb open4153971 Ref: 2bf4153971 Ref: library/dbm dbm dumb dumbdbm sync4155916 Ref: 19bb4155916 Ref: library/dbm dbm dumb dumbdbm close4156079 Ref: 19bc4156079 Ref: dbm dumb — Portable DBM implementation-Footnote-14156195 Node: sqlite3 — DB-API 2 0 interface for SQLite databases4156262 Ref: library/sqlite3 doc4156419 Ref: 19bd4156419 Ref: library/sqlite3 module-sqlite34156419 Ref: f24156419 Ref: library/sqlite3 sqlite3-db-api-2-0-interface-for-sqlite-databases4156419 Ref: 19be4156419 Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-14160767 Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-24160831 Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-34160880 Node: Module functions and constants4160929 Ref: library/sqlite3 module-functions-and-constants4161076 Ref: 19c34161076 Ref: library/sqlite3 sqlite3-module-contents4161076 Ref: 19c44161076 Ref: library/sqlite3 sqlite3 version4161157 Ref: 19c54161157 Ref: library/sqlite3 sqlite3 version_info4161291 Ref: 19c64161291 Ref: library/sqlite3 sqlite3 sqlite_version4161441 Ref: 19c74161441 Ref: library/sqlite3 sqlite3 sqlite_version_info4161545 Ref: 19c84161545 Ref: library/sqlite3 sqlite3 PARSE_DECLTYPES4161670 Ref: 19c94161670 Ref: library/sqlite3 sqlite3 PARSE_COLNAMES4162272 Ref: 19ca4162272 Ref: library/sqlite3 sqlite3 connect4163166 Ref: 3da4163166 Ref: library/sqlite3 sqlite3 register_converter4166783 Ref: 19cd4166783 Ref: library/sqlite3 sqlite3 register_adapter4167264 Ref: 19cf4167264 Ref: library/sqlite3 sqlite3 complete_statement4167589 Ref: 19d04167589 Ref: library/sqlite3 sqlite3 enable_callback_tracebacks4168923 Ref: 19d14168923 Ref: Module functions and constants-Footnote-14169374 Node: Connection Objects4169414 Ref: library/sqlite3 connection-objects4169584 Ref: 19d24169584 Ref: library/sqlite3 sqlite3-connection-objects4169584 Ref: 19d34169584 Ref: library/sqlite3 sqlite3 Connection4169641 Ref: 3d84169641 Ref: library/sqlite3 sqlite3 Connection isolation_level4169754 Ref: 19cc4169754 Ref: library/sqlite3 sqlite3 Connection in_transaction4170064 Ref: 19d54170064 Ref: library/sqlite3 sqlite3 Connection cursor4170290 Ref: 19d64170290 Ref: library/sqlite3 sqlite3 Connection commit4170530 Ref: 19d74170530 Ref: library/sqlite3 sqlite3 Connection rollback4170923 Ref: 19d84170923 Ref: library/sqlite3 sqlite3 Connection close4171070 Ref: 19d94171070 Ref: library/sqlite3 sqlite3 Connection execute4171357 Ref: 19da4171357 Ref: library/sqlite3 sqlite3 Connection executemany4171653 Ref: 19db4171653 Ref: library/sqlite3 sqlite3 Connection executescript4171957 Ref: 19dd4171957 Ref: library/sqlite3 sqlite3 Connection create_function4172258 Ref: 19df4172258 Ref: library/sqlite3 sqlite3 Connection create_aggregate4173670 Ref: 19e14173670 Ref: library/sqlite3 sqlite3 Connection create_collation4175002 Ref: 19e24175002 Ref: library/sqlite3 sqlite3 Connection interrupt4176612 Ref: 19e34176612 Ref: library/sqlite3 sqlite3 Connection set_authorizer4176852 Ref: 19e44176852 Ref: library/sqlite3 sqlite3 Connection set_progress_handler4178212 Ref: 19e54178212 Ref: library/sqlite3 sqlite3 Connection set_trace_callback4178870 Ref: a8d4178870 Ref: library/sqlite3 sqlite3 Connection enable_load_extension4179637 Ref: b994179637 Ref: library/sqlite3 sqlite3 Connection load_extension4181451 Ref: b9a4181451 Ref: library/sqlite3 sqlite3 Connection row_factory4181791 Ref: 19e74181791 Ref: library/sqlite3 sqlite3 Connection text_factory4183157 Ref: 19e84183157 Ref: library/sqlite3 sqlite3 Connection total_changes4184874 Ref: 19e94184874 Ref: library/sqlite3 sqlite3 Connection iterdump4185070 Ref: 19ea4185070 Ref: library/sqlite3 sqlite3 Connection backup4185717 Ref: 3d94185717 Ref: Connection Objects-Footnote-14188130 Ref: Connection Objects-Footnote-24188176 Ref: Connection Objects-Footnote-34188475 Node: Cursor Objects4188774 Ref: library/sqlite3 cursor-objects4188925 Ref: 19eb4188925 Ref: library/sqlite3 sqlite3-cursor-objects4188925 Ref: 19ec4188925 Ref: library/sqlite3 sqlite3 Cursor4188974 Ref: 19bf4188974 Ref: library/sqlite3 sqlite3 Cursor execute4189085 Ref: 19c04189085 Ref: library/sqlite3 sqlite3 Cursor executemany4190362 Ref: 19dc4190362 Ref: library/sqlite3 sqlite3 Cursor executescript4192142 Ref: 19de4192142 Ref: library/sqlite3 sqlite3 Cursor fetchone4193256 Ref: 19c14193256 Ref: library/sqlite3 sqlite3 Cursor fetchmany4193432 Ref: 19ee4193432 Ref: library/sqlite3 sqlite3 Cursor fetchall4194409 Ref: 19c24194409 Ref: library/sqlite3 sqlite3 Cursor close4194693 Ref: 19ef4194693 Ref: library/sqlite3 sqlite3 Cursor rowcount4194998 Ref: 19f14194998 Ref: library/sqlite3 sqlite3 Cursor lastrowid4195992 Ref: 57e4195992 Ref: library/sqlite3 sqlite3 Cursor arraysize4196641 Ref: 19f24196641 Ref: library/sqlite3 sqlite3 Cursor description4196870 Ref: 19cb4196870 Ref: library/sqlite3 sqlite3 Cursor connection4197251 Ref: 19f34197251 Node: Row Objects4197747 Ref: library/sqlite3 row-objects4197893 Ref: 19f44197893 Ref: library/sqlite3 sqlite3-row-objects4197893 Ref: 19f54197893 Ref: library/sqlite3 sqlite3 Row4197936 Ref: 75e4197936 Ref: library/sqlite3 sqlite3 Row keys4198396 Ref: 19f64198396 Node: Exceptions<4>4199636 Ref: library/sqlite3 exceptions4199791 Ref: 19f74199791 Ref: library/sqlite3 sqlite3-exceptions4199791 Ref: 19f84199791 Ref: library/sqlite3 sqlite3 Warning4199832 Ref: 19ed4199832 Ref: library/sqlite3 sqlite3 Error4199906 Ref: 19f94199906 Ref: library/sqlite3 sqlite3 DatabaseError4200045 Ref: 19fa4200045 Ref: library/sqlite3 sqlite3 IntegrityError4200151 Ref: 19fb4200151 Ref: library/sqlite3 sqlite3 ProgrammingError4200363 Ref: 19f04200363 Ref: library/sqlite3 sqlite3 OperationalError4200633 Ref: 19e64200633 Ref: library/sqlite3 sqlite3 NotSupportedError4200997 Ref: 19e04200997 Node: SQLite and Python types4201343 Ref: library/sqlite3 sqlite-and-python-types4201511 Ref: 19fc4201511 Ref: library/sqlite3 sqlite3-types4201511 Ref: 19ce4201511 Node: Introduction<7>4201781 Ref: library/sqlite3 introduction4201932 Ref: 19fd4201932 Node: Using adapters to store additional Python types in SQLite databases4203819 Ref: library/sqlite3 using-adapters-to-store-additional-python-types-in-sqlite-databases4204026 Ref: 19fe4204026 Node: Letting your object adapt itself4204624 Ref: library/sqlite3 letting-your-object-adapt-itself4204800 Ref: 19ff4204800 Node: Registering an adapter callable4205913 Ref: library/sqlite3 registering-an-adapter-callable4206089 Ref: 1a004206089 Node: Converting SQLite values to custom Python types4207405 Ref: library/sqlite3 converting-sqlite-values-to-custom-python-types4207628 Ref: 1a014207628 Node: Default adapters and converters4210257 Ref: library/sqlite3 default-adapters-and-converters4210404 Ref: 1a024210404 Node: Controlling Transactions4211962 Ref: library/sqlite3 controlling-transactions4212142 Ref: 1a034212142 Ref: library/sqlite3 sqlite3-controlling-transactions4212142 Ref: 19d44212142 Node: Using sqlite3 efficiently4213798 Ref: library/sqlite3 using-sqlite3-efficiently4213946 Ref: 1a044213946 Node: Using shortcut methods4214160 Ref: library/sqlite3 using-shortcut-methods4214298 Ref: 1a054214298 Node: Accessing columns by name instead of by index4215596 Ref: library/sqlite3 accessing-columns-by-name-instead-of-by-index4215784 Ref: 1a064215784 Node: Using the connection as a context manager4216508 Ref: library/sqlite3 using-the-connection-as-a-context-manager4216665 Ref: 1a074216665 Node: Data Compression and Archiving4217776 Ref: library/archiving doc4217916 Ref: 196d4217916 Ref: library/archiving archiving4217916 Ref: 1a084217916 Ref: library/archiving data-compression-and-archiving4217916 Ref: 1a094217916 Node: zlib — Compression compatible with gzip4218508 Ref: library/zlib doc4218656 Ref: 1a0a4218656 Ref: library/zlib module-zlib4218656 Ref: 1444218656 Ref: library/zlib zlib-compression-compatible-with-gzip4218656 Ref: 1a0b4218656 Ref: library/zlib zlib error4219621 Ref: 1a0c4219621 Ref: library/zlib zlib adler324219712 Ref: 1a0d4219712 Ref: library/zlib zlib compress4220625 Ref: 5be4220625 Ref: library/zlib zlib compressobj4221399 Ref: 1a0e4221399 Ref: library/zlib zlib crc324224133 Ref: 1a0f4224133 Ref: library/zlib zlib decompress4224961 Ref: 5bf4224961 Ref: library/zlib decompress-wbits4225391 Ref: 1a104225391 Ref: library/zlib zlib decompressobj4227126 Ref: 1a114227126 Ref: library/zlib zlib Compress compress4228125 Ref: 1a124228125 Ref: library/zlib zlib Compress flush4228483 Ref: 1a134228483 Ref: library/zlib zlib Compress copy4229238 Ref: 1a144229238 Ref: library/zlib zlib Decompress unused_data4229606 Ref: 1a154229606 Ref: library/zlib zlib Decompress unconsumed_tail4229952 Ref: 1a164229952 Ref: library/zlib zlib Decompress eof4230406 Ref: ac64230406 Ref: library/zlib zlib Decompress decompress4230689 Ref: 1a174230689 Ref: library/zlib zlib Decompress flush4231716 Ref: 1a184231716 Ref: library/zlib zlib Decompress copy4232121 Ref: 1a194232121 Ref: library/zlib zlib ZLIB_VERSION4232599 Ref: 1a1a4232599 Ref: library/zlib zlib ZLIB_RUNTIME_VERSION4232853 Ref: ac74232853 Node: gzip — Support for gzip files4233291 Ref: library/gzip doc4233485 Ref: 1a1b4233485 Ref: library/gzip gzip-support-for-gzip-files4233485 Ref: 1a1c4233485 Ref: library/gzip module-gzip4233485 Ref: 8c4233485 Ref: library/gzip gzip open4234480 Ref: 1a1d4234480 Ref: library/gzip gzip BadGzipFile4236011 Ref: 1d24236011 Ref: library/gzip gzip GzipFile4236256 Ref: 6dd4236256 Ref: library/gzip gzip GzipFile peek4239077 Ref: b884239077 Ref: library/gzip gzip GzipFile mtime4239701 Ref: 1a1e4239701 Ref: library/gzip gzip compress4241036 Ref: 1d14241036 Ref: library/gzip gzip decompress4241425 Ref: b894241425 Ref: gzip — Support for gzip files-Footnote-14241689 Node: Examples of usage4241752 Ref: library/gzip examples-of-usage4241868 Ref: 1a234241868 Ref: library/gzip gzip-usage-examples4241868 Ref: 1a244241868 Node: Command Line Interface4242786 Ref: library/gzip command-line-interface4242902 Ref: 1a254242902 Node: Command line options4243322 Ref: library/gzip command-line-options4243401 Ref: 1a264243401 Ref: library/gzip cmdoption-gzip-arg-file4243462 Ref: 1a274243462 Ref: library/gzip cmdoption-gzip-fast4243554 Ref: 1a284243554 Ref: library/gzip cmdoption-gzip-best4243649 Ref: 1a294243649 Ref: library/gzip cmdoption-gzip-d4243744 Ref: 1a2a4243744 Ref: library/gzip cmdoption-gzip-h4243815 Ref: 1a2b4243815 Node: bz2 — Support for bzip2 compression4243876 Ref: library/bz2 doc4244074 Ref: 1a2c4244074 Ref: library/bz2 bz2-support-for-bzip2-compression4244074 Ref: 1a2d4244074 Ref: library/bz2 module-bz24244074 Ref: 144244074 Ref: bz2 — Support for bzip2 compression-Footnote-14245114 Node: De compression of files4245176 Ref: library/bz2 de-compression-of-files4245308 Ref: 1a304245308 Ref: library/bz2 bz2 open4245377 Ref: 9d64245377 Ref: library/bz2 bz2 BZ2File4246814 Ref: 9314246814 Ref: library/bz2 bz2 BZ2File peek4248364 Ref: 1a314248364 Node: Incremental de compression4249828 Ref: library/bz2 incremental-de-compression4249992 Ref: 1a324249992 Ref: library/bz2 bz2 BZ2Compressor4250067 Ref: 1a2e4250067 Ref: library/bz2 bz2 BZ2Compressor compress4250407 Ref: 1a334250407 Ref: library/bz2 bz2 BZ2Compressor flush4250755 Ref: 1a344250755 Ref: library/bz2 bz2 BZ2Decompressor4250984 Ref: 1a2f4250984 Ref: library/bz2 bz2 BZ2Decompressor decompress4251535 Ref: 6a34251535 Ref: library/bz2 bz2 BZ2Decompressor eof4252893 Ref: 1a374252893 Ref: library/bz2 bz2 BZ2Decompressor unused_data4253017 Ref: 1a364253017 Ref: library/bz2 bz2 BZ2Decompressor needs_input4253239 Ref: 1a354253239 Node: One-shot de compression4253461 Ref: library/bz2 one-shot-de-compression4253622 Ref: 1a384253622 Ref: library/bz2 bz2 compress4253691 Ref: 151f4253691 Ref: library/bz2 bz2 decompress4253990 Ref: 9d74253990 Node: Examples of usage<2>4254348 Ref: library/bz2 bz2-usage-examples4254474 Ref: 1a394254474 Ref: library/bz2 examples-of-usage4254474 Ref: 1a3a4254474 Node: lzma — Compression using the LZMA algorithm4257394 Ref: library/lzma doc4257595 Ref: 1a3b4257595 Ref: library/lzma lzma-compression-using-the-lzma-algorithm4257595 Ref: 1a3c4257595 Ref: library/lzma module-lzma4257595 Ref: ad4257595 Ref: library/lzma lzma LZMAError4258436 Ref: 1a3d4258436 Ref: lzma — Compression using the LZMA algorithm-Footnote-14258855 Node: Reading and writing compressed files4258918 Ref: library/lzma reading-and-writing-compressed-files4259089 Ref: 1a3e4259089 Ref: library/lzma lzma open4259182 Ref: 1a3f4259182 Ref: library/lzma lzma LZMAFile4260949 Ref: 9324260949 Ref: library/lzma lzma LZMAFile peek4262826 Ref: 1a424262826 Node: Compressing and decompressing data in memory4263707 Ref: library/lzma compressing-and-decompressing-data-in-memory4263903 Ref: 1a434263903 Ref: library/lzma lzma LZMACompressor4264012 Ref: 1a414264012 Ref: library/lzma lzma LZMACompressor compress4267090 Ref: 1a464267090 Ref: library/lzma lzma LZMACompressor flush4267563 Ref: 1a474267563 Ref: library/lzma lzma LZMADecompressor4267843 Ref: 1a404267843 Ref: library/lzma lzma LZMADecompressor decompress4269371 Ref: 7144269371 Ref: library/lzma lzma LZMADecompressor check4270732 Ref: 1a4b4270732 Ref: library/lzma lzma LZMADecompressor eof4270965 Ref: 1a4c4270965 Ref: library/lzma lzma LZMADecompressor unused_data4271058 Ref: 1a4a4271058 Ref: library/lzma lzma LZMADecompressor needs_input4271229 Ref: 1a494271229 Ref: library/lzma lzma compress4271451 Ref: 1a444271451 Ref: library/lzma lzma decompress4271797 Ref: 1a484271797 Node: Miscellaneous<2>4272304 Ref: library/lzma miscellaneous4272495 Ref: 1a4d4272495 Ref: library/lzma lzma is_check_supported4272542 Ref: 1a4e4272542 Node: Specifying custom filter chains4272904 Ref: library/lzma filter-chain-specs4273062 Ref: 1a454273062 Ref: library/lzma specifying-custom-filter-chains4273062 Ref: 1a4f4273062 Node: Examples<5>4275911 Ref: library/lzma examples4276044 Ref: 1a504276044 Node: zipfile — Work with ZIP archives4277412 Ref: library/zipfile doc4277620 Ref: 1a514277620 Ref: library/zipfile module-zipfile4277620 Ref: 1424277620 Ref: library/zipfile zipfile-work-with-zip-archives4277620 Ref: 1a524277620 Ref: library/zipfile zipfile BadZipFile4278483 Ref: 1a534278483 Ref: library/zipfile zipfile BadZipfile4278586 Ref: 1a544278586 Ref: library/zipfile zipfile LargeZipFile4278747 Ref: 1a554278747 Ref: library/zipfile zipfile ZipInfo4279299 Ref: 5ba4279299 Ref: library/zipfile zipfile is_zipfile4279997 Ref: cba4279997 Ref: library/zipfile zipfile ZIP_STORED4280290 Ref: 1a5b4280290 Ref: library/zipfile zipfile ZIP_DEFLATED4280383 Ref: 1a5c4280383 Ref: library/zipfile zipfile ZIP_BZIP24280529 Ref: 1a5d4280529 Ref: library/zipfile zipfile ZIP_LZMA4280692 Ref: 1a5e4280692 Ref: zipfile — Work with ZIP archives-Footnote-14281698 Ref: zipfile — Work with ZIP archives-Footnote-24281764 Ref: zipfile — Work with ZIP archives-Footnote-34281832 Ref: zipfile — Work with ZIP archives-Footnote-44281900 Node: ZipFile Objects4281933 Ref: library/zipfile id14282040 Ref: 1a5f4282040 Ref: library/zipfile zipfile-objects4282040 Ref: 1a564282040 Ref: library/zipfile zipfile ZipFile4282091 Ref: 41f4282091 Ref: library/zipfile zipfile ZipFile close4286082 Ref: 1a604286082 Ref: library/zipfile zipfile ZipFile getinfo4286253 Ref: 1a584286253 Ref: library/zipfile zipfile ZipFile infolist4286512 Ref: 1a594286512 Ref: library/zipfile zipfile ZipFile namelist4286770 Ref: 1a614286770 Ref: library/zipfile zipfile ZipFile open4286851 Ref: 5bc4286851 Ref: library/zipfile zipfile ZipFile extract4289238 Ref: 1a654289238 Ref: library/zipfile zipfile ZipFile extractall4290597 Ref: 1a664290597 Ref: library/zipfile zipfile ZipFile printdir4291615 Ref: 1a674291615 Ref: library/zipfile zipfile ZipFile setpassword4291717 Ref: 1a684291717 Ref: library/zipfile zipfile ZipFile read4291820 Ref: cb94291820 Ref: library/zipfile zipfile ZipFile testzip4292722 Ref: 1a694292722 Ref: library/zipfile zipfile ZipFile write4293092 Ref: 60f4293092 Ref: library/zipfile zipfile ZipFile writestr4294258 Ref: cbb4294258 Ref: library/zipfile zipfile ZipFile filename4295898 Ref: 1a6a4295898 Ref: library/zipfile zipfile ZipFile debug4295959 Ref: 1a6b4295959 Ref: library/zipfile zipfile ZipFile comment4296179 Ref: 1a6c4296179 Node: Path Objects4296502 Ref: library/zipfile id24296635 Ref: 1a6d4296635 Ref: library/zipfile path-objects4296635 Ref: 1a574296635 Ref: library/zipfile zipfile Path4296680 Ref: 1a6e4296680 Ref: library/zipfile zipfile Path name4297226 Ref: 1a6f4297226 Ref: library/zipfile zipfile Path open4297284 Ref: 1a704297284 Ref: library/zipfile zipfile Path iterdir4297665 Ref: 1a714297665 Ref: library/zipfile zipfile Path is_dir4297749 Ref: 1a724297749 Ref: library/zipfile zipfile Path is_file4297848 Ref: 1a734297848 Ref: library/zipfile zipfile Path exists4297943 Ref: 1a744297943 Ref: library/zipfile zipfile Path read_text4298071 Ref: 1a754298071 Ref: library/zipfile zipfile Path read_bytes4298303 Ref: 1a764298303 Node: PyZipFile Objects4298373 Ref: library/zipfile id34298506 Ref: 1a774298506 Ref: library/zipfile pyzipfile-objects4298506 Ref: 1a784298506 Ref: library/zipfile zipfile PyZipFile4298708 Ref: 91b4298708 Ref: library/zipfile zipfile PyZipFile writepy4299032 Ref: 91a4299032 Node: ZipInfo Objects4301859 Ref: library/zipfile id44302002 Ref: 1a794302002 Ref: library/zipfile zipinfo-objects4302002 Ref: 1a5a4302002 Ref: library/zipfile zipfile ZipInfo from_file4302370 Ref: 5b94302370 Ref: library/zipfile zipfile ZipInfo is_dir4303437 Ref: 5bb4303437 Ref: library/zipfile zipfile ZipInfo filename4303637 Ref: 1a7a4303637 Ref: library/zipfile zipfile ZipInfo date_time4303709 Ref: 1a7b4303709 Ref: library/zipfile zipfile ZipInfo compress_type4304491 Ref: 1a7c4304491 Ref: library/zipfile zipfile ZipInfo comment4304579 Ref: 1a7d4304579 Ref: library/zipfile zipfile ZipInfo extra4304695 Ref: 1a7e4304695 Ref: library/zipfile zipfile ZipInfo create_system4304899 Ref: 1a7f4304899 Ref: library/zipfile zipfile ZipInfo create_version4304977 Ref: 1a804304977 Ref: library/zipfile zipfile ZipInfo extract_version4305063 Ref: 1a814305063 Ref: library/zipfile zipfile ZipInfo reserved4305150 Ref: 1a824305150 Ref: library/zipfile zipfile ZipInfo flag_bits4305203 Ref: 1a834305203 Ref: library/zipfile zipfile ZipInfo volume4305258 Ref: 1a844305258 Ref: library/zipfile zipfile ZipInfo internal_attr4305325 Ref: 1a854305325 Ref: library/zipfile zipfile ZipInfo external_attr4305390 Ref: 1a864305390 Ref: library/zipfile zipfile ZipInfo header_offset4305460 Ref: 1a874305460 Ref: library/zipfile zipfile ZipInfo CRC4305536 Ref: 1a884305536 Ref: library/zipfile zipfile ZipInfo compress_size4305603 Ref: 1a894305603 Ref: library/zipfile zipfile ZipInfo file_size4305676 Ref: 1a644305676 Ref: ZipInfo Objects-Footnote-14305783 Node: Command-Line Interface4305851 Ref: library/zipfile command-line-interface4305999 Ref: 1a8a4305999 Ref: library/zipfile zipfile-commandline4305999 Ref: 1a8b4305999 Node: Command-line options4306772 Ref: library/zipfile command-line-options4306851 Ref: 1a8f4306851 Ref: library/zipfile cmdoption-zipfile-l4306912 Ref: 1a8e4306912 Ref: library/zipfile cmdoption-zipfile-list4306945 Ref: 1a904306945 Ref: library/zipfile cmdoption-zipfile-c4307014 Ref: 1a8c4307014 Ref: library/zipfile cmdoption-zipfile-create4307071 Ref: 1a914307071 Ref: library/zipfile cmdoption-zipfile-e4307175 Ref: 1a8d4307175 Ref: library/zipfile cmdoption-zipfile-extract4307221 Ref: 1a924307221 Ref: library/zipfile cmdoption-zipfile-t4307320 Ref: 1a934307320 Ref: library/zipfile cmdoption-zipfile-test4307353 Ref: 1a944307353 Node: Decompression pitfalls4307439 Ref: library/zipfile decompression-pitfalls4307563 Ref: 1a954307563 Node: From file itself4307846 Ref: library/zipfile from-file-itself4307953 Ref: 1a964307953 Node: File System limitations4308132 Ref: library/zipfile file-system-limitations4308269 Ref: 1a974308269 Node: Resources limitations4308571 Ref: library/zipfile resources-limitations4308704 Ref: 1a984308704 Ref: Resources limitations-Footnote-14308991 Node: Interruption4309038 Ref: library/zipfile interruption4309179 Ref: 1a994309179 Node: Default behaviors of extraction4309385 Ref: library/zipfile default-behaviors-of-extraction4309496 Ref: 1a9a4309496 Node: tarfile — Read and write tar archive files4309761 Ref: library/tarfile doc4309915 Ref: 1a9b4309915 Ref: library/tarfile module-tarfile4309915 Ref: 1014309915 Ref: library/tarfile pkzip-application-note4309915 Ref: 1a9c4309915 Ref: library/tarfile tarfile-read-and-write-tar-archive-files4309915 Ref: 1a9d4309915 Ref: library/tarfile tarfile open4311177 Ref: 7664311177 Ref: library/tarfile tarfile is_tarfile4317464 Ref: 1aa24317464 Ref: library/tarfile tarfile TarError4317685 Ref: 1aa34317685 Ref: library/tarfile tarfile ReadError4317775 Ref: 1a9f4317775 Ref: library/tarfile tarfile CompressionError4317947 Ref: 1aa04317947 Ref: library/tarfile tarfile StreamError4318097 Ref: 1aa44318097 Ref: library/tarfile tarfile ExtractError4318236 Ref: 1aa54318236 Ref: library/tarfile tarfile HeaderError4318406 Ref: 1aa64318406 Ref: library/tarfile tarfile ENCODING4318591 Ref: 1aa84318591 Ref: library/tarfile tarfile USTAR_FORMAT4318939 Ref: 1aaa4318939 Ref: library/tarfile tarfile GNU_FORMAT4319006 Ref: 1aab4319006 Ref: library/tarfile tarfile PAX_FORMAT4319058 Ref: 1aac4319058 Ref: library/tarfile tarfile DEFAULT_FORMAT4319121 Ref: 1aad4319121 Ref: tarfile — Read and write tar archive files-Footnote-14319971 Ref: tarfile — Read and write tar archive files-Footnote-24320037 Node: TarFile Objects4320109 Ref: library/tarfile id14320229 Ref: 1aae4320229 Ref: library/tarfile tarfile-objects4320229 Ref: 1a9e4320229 Ref: library/tarfile tarfile TarFile4321097 Ref: b8c4321097 Ref: library/tarfile tarfile TarFile open4324487 Ref: 1ab14324487 Ref: library/tarfile tarfile TarFile getmember4324652 Ref: 1ab24324652 Ref: library/tarfile tarfile TarFile getmembers4324975 Ref: 76a4324975 Ref: library/tarfile tarfile TarFile getnames4325162 Ref: 1ab34325162 Ref: library/tarfile tarfile TarFile list4325323 Ref: 7694325323 Ref: library/tarfile tarfile TarFile next4325773 Ref: 1ab44325773 Ref: library/tarfile tarfile TarFile extractall4325993 Ref: 7674325993 Ref: library/tarfile tarfile TarFile extract4327304 Ref: 7684327304 Ref: library/tarfile tarfile TarFile extractfile4328519 Ref: 1ab54328519 Ref: library/tarfile tarfile TarFile add4328915 Ref: 47c4328915 Ref: library/tarfile tarfile TarFile addfile4329821 Ref: 1ab64329821 Ref: library/tarfile tarfile TarFile gettarinfo4330188 Ref: 1ab74330188 Ref: library/tarfile tarfile TarFile close4331329 Ref: 1abb4331329 Ref: library/tarfile tarfile TarFile pax_headers4331471 Ref: 1abc4331471 Node: TarInfo Objects4331576 Ref: library/tarfile id24331730 Ref: 1abd4331730 Ref: library/tarfile tarinfo-objects4331730 Ref: 1aaf4331730 Ref: library/tarfile tarfile TarInfo4332210 Ref: b8d4332210 Ref: library/tarfile tarfile TarInfo frombuf4332291 Ref: 1aa74332291 Ref: library/tarfile tarfile TarInfo fromtarfile4332504 Ref: 1abe4332504 Ref: library/tarfile tarfile TarInfo tobuf4332684 Ref: 1abf4332684 Ref: library/tarfile tarfile TarInfo name4333123 Ref: 1aba4333123 Ref: library/tarfile tarfile TarInfo size4333186 Ref: 1ab94333186 Ref: library/tarfile tarfile TarInfo mtime4333236 Ref: 1ac04333236 Ref: library/tarfile tarfile TarInfo mode4333299 Ref: 1ac14333299 Ref: library/tarfile tarfile TarInfo type4333351 Ref: 1ac24333351 Ref: library/tarfile tarfile TarInfo linkname4333729 Ref: 1ac34333729 Ref: library/tarfile tarfile TarInfo uid4333897 Ref: 1ac44333897 Ref: library/tarfile tarfile TarInfo gid4333986 Ref: 1ac54333986 Ref: library/tarfile tarfile TarInfo uname4334076 Ref: 1ac64334076 Ref: library/tarfile tarfile TarInfo gname4334123 Ref: 1ac74334123 Ref: library/tarfile tarfile TarInfo pax_headers4334171 Ref: 1ac84334171 Ref: library/tarfile tarfile TarInfo isfile4334371 Ref: 1ac94334371 Ref: library/tarfile tarfile TarInfo isreg4334479 Ref: 1aca4334479 Ref: library/tarfile tarfile TarInfo isdir4334545 Ref: 1acb4334545 Ref: library/tarfile tarfile TarInfo issym4334627 Ref: 1acc4334627 Ref: library/tarfile tarfile TarInfo islnk4334713 Ref: 1acd4334713 Ref: library/tarfile tarfile TarInfo ischr4334795 Ref: 1ace4334795 Ref: library/tarfile tarfile TarInfo isblk4334884 Ref: 1acf4334884 Ref: library/tarfile tarfile TarInfo isfifo4334969 Ref: 1ad04334969 Ref: library/tarfile tarfile TarInfo isdev4335047 Ref: 1ad14335047 Node: Command-Line Interface<2>4335168 Ref: library/tarfile command-line-interface4335318 Ref: 1ad24335318 Ref: library/tarfile tarfile-commandline4335318 Ref: 8e84335318 Node: Command-line options<2>4336272 Ref: library/tarfile command-line-options4336357 Ref: 1ad64336357 Ref: library/tarfile cmdoption-tarfile-l4336418 Ref: 1ad54336418 Ref: library/tarfile cmdoption-tarfile-list4336451 Ref: 1ad74336451 Ref: library/tarfile cmdoption-tarfile-c4336520 Ref: 1ad34336520 Ref: library/tarfile cmdoption-tarfile-create4336577 Ref: 1ad84336577 Ref: library/tarfile cmdoption-tarfile-e4336681 Ref: 1ad44336681 Ref: library/tarfile cmdoption-tarfile-extract4336729 Ref: 1ad94336729 Ref: library/tarfile cmdoption-tarfile-t4336873 Ref: 1ada4336873 Ref: library/tarfile cmdoption-tarfile-test4336906 Ref: 1adb4336906 Ref: library/tarfile cmdoption-tarfile-v4336992 Ref: 1adc4336992 Node: Examples<6>4337049 Ref: library/tarfile examples4337205 Ref: 1add4337205 Ref: library/tarfile tar-examples4337205 Ref: 1aa14337205 Node: Supported tar formats4339078 Ref: library/tarfile supported-tar-formats4339223 Ref: 1ade4339223 Ref: library/tarfile tar-formats4339223 Ref: 1aa94339223 Node: Unicode issues4341445 Ref: library/tarfile tar-unicode4341570 Ref: 1ab04341570 Ref: library/tarfile unicode-issues4341570 Ref: 1adf4341570 Node: File Formats4343542 Ref: library/fileformats doc4343688 Ref: 1ae14343688 Ref: library/fileformats file-formats4343688 Ref: 1ae24343688 Ref: library/fileformats fileformats4343688 Ref: 1ae34343688 Node: csv — CSV File Reading and Writing4344154 Ref: library/csv doc4344290 Ref: 1ae44344290 Ref: library/csv csv-csv-file-reading-and-writing4344290 Ref: 1ae54344290 Ref: library/csv module-csv4344290 Ref: 2a4344290 Ref: csv — CSV File Reading and Writing-Footnote-14346200 Ref: csv — CSV File Reading and Writing-Footnote-24346262 Ref: csv — CSV File Reading and Writing-Footnote-34346311 Node: Module Contents<3>4346360 Ref: library/csv csv-contents4346494 Ref: 1ae74346494 Ref: library/csv module-contents4346494 Ref: 1ae84346494 Ref: library/csv csv reader4346605 Ref: 1ae64346605 Ref: library/csv csv writer4348275 Ref: dfc4348275 Ref: library/csv csv register_dialect4350032 Ref: 1aec4350032 Ref: library/csv csv unregister_dialect4350505 Ref: 1aed4350505 Ref: library/csv csv get_dialect4350712 Ref: 1aef4350712 Ref: library/csv csv list_dialects4350943 Ref: 1aea4350943 Ref: library/csv csv field_size_limit4351030 Ref: 1af04351030 Ref: library/csv csv DictReader4351265 Ref: 1bd4351265 Ref: library/csv csv DictWriter4352866 Ref: b7a4352866 Ref: library/csv csv Dialect4354529 Ref: 1ae94354529 Ref: library/csv csv excel4354773 Ref: 1af14354773 Ref: library/csv csv excel_tab4354956 Ref: 1af24354956 Ref: library/csv csv unix_dialect4355161 Ref: b794355161 Ref: library/csv csv Sniffer4355462 Ref: 1af34355462 Ref: library/csv csv Sniffer sniff4355631 Ref: 1af44355631 Ref: library/csv csv Sniffer has_header4355953 Ref: 1af54355953 Ref: library/csv csv QUOTE_ALL4356502 Ref: 1af64356502 Ref: library/csv csv QUOTE_MINIMAL4356591 Ref: 1af74356591 Ref: library/csv csv QUOTE_NONNUMERIC4356812 Ref: 1af84356812 Ref: library/csv csv QUOTE_NONE4357007 Ref: 1af94357007 Ref: library/csv csv Error4357507 Ref: 1aee4357507 Ref: Module Contents<3>-Footnote-14357633 Ref: Module Contents<3>-Footnote-24357978 Node: Dialects and Formatting Parameters4358323 Ref: library/csv csv-fmt-params4358480 Ref: 1aeb4358480 Ref: library/csv dialects-and-formatting-parameters4358480 Ref: 1afa4358480 Ref: library/csv csv Dialect delimiter4359273 Ref: 1afb4359273 Ref: library/csv csv Dialect doublequote4359393 Ref: 1afc4359393 Ref: library/csv csv Dialect escapechar4359865 Ref: 1afd4359865 Ref: library/csv csv Dialect lineterminator4360245 Ref: 1afe4360245 Ref: library/csv csv Dialect quotechar4360602 Ref: 1aff4360602 Ref: library/csv csv Dialect quoting4360832 Ref: 1b004360832 Ref: library/csv csv Dialect skipinitialspace4361107 Ref: 1b014361107 Ref: library/csv csv Dialect strict4361276 Ref: 1b024361276 Node: Reader Objects4361416 Ref: library/csv reader-objects4361569 Ref: 1b034361569 Ref: library/csv csv csvreader __next__4361763 Ref: 1b044361763 Ref: library/csv csv csvreader dialect4362143 Ref: 1b054362143 Ref: library/csv csv csvreader line_num4362244 Ref: 1b064362244 Ref: library/csv csv csvreader fieldnames4362496 Ref: 1b074362496 Node: Writer Objects4362700 Ref: library/csv writer-objects4362830 Ref: 1b084362830 Ref: library/csv csv csvwriter writerow4363431 Ref: 6c44363431 Ref: library/csv csv csvwriter writerows4363744 Ref: 1b094363744 Ref: library/csv csv csvwriter dialect4364007 Ref: 1b0a4364007 Ref: library/csv csv DictWriter writeheader4364162 Ref: b7b4364162 Node: Examples<7>4364646 Ref: library/csv csv-examples4364753 Ref: 1b0b4364753 Ref: library/csv examples4364753 Ref: 1b0c4364753 Node: configparser — Configuration file parser4366765 Ref: library/configparser doc4366941 Ref: 1b0d4366941 Ref: library/configparser configparser-configuration-file-parser4366941 Ref: 1b0e4366941 Ref: library/configparser module-configparser4366941 Ref: 234366941 Ref: configparser — Configuration file parser-Footnote-14368235 Node: Quick Start4368306 Ref: library/configparser quick-start4368424 Ref: 1b0f4368424 Ref: Quick Start-Footnote-14371105 Ref: Quick Start-Footnote-24371311 Node: Supported Datatypes4371517 Ref: library/configparser supported-datatypes4371659 Ref: 1b134371659 Ref: Supported Datatypes-Footnote-14372981 Ref: Supported Datatypes-Footnote-24373187 Node: Fallback Values4373393 Ref: library/configparser fallback-values4373552 Ref: 1b174373552 Node: Supported INI File Structure4375050 Ref: library/configparser supported-ini-file-structure4375213 Ref: 1b104375213 Ref: Supported INI File Structure-Footnote-14377489 Ref: Supported INI File Structure-Footnote-24377695 Ref: Supported INI File Structure-Footnote-34377901 Ref: Supported INI File Structure-Footnote-44378107 Node: Interpolation of values4378313 Ref: library/configparser interpolation-of-values4378484 Ref: 1b184378484 Ref: library/configparser configparser BasicInterpolation4378720 Ref: 1b194378720 Ref: library/configparser configparser ExtendedInterpolation4379999 Ref: bdc4379999 Ref: Interpolation of values-Footnote-14381480 Node: Mapping Protocol Access4381686 Ref: library/configparser mapping-protocol-access4381857 Ref: 1b114381857 Ref: Mapping Protocol Access-Footnote-14384746 Node: Customizing Parser Behaviour4384952 Ref: library/configparser customizing-parser-behaviour4385119 Ref: 1b124385119 Ref: library/configparser configparser ConfigParser BOOLEAN_STATES4395862 Ref: 1b1b4395862 Ref: library/configparser configparser ConfigParser SECTCRE4398048 Ref: 1b1c4398048 Node: Legacy API Examples4399290 Ref: library/configparser legacy-api-examples4399454 Ref: 1b1d4399454 Node: ConfigParser Objects4403272 Ref: library/configparser configparser-objects4403431 Ref: 1b1e4403431 Ref: library/configparser id114403431 Ref: 1b1f4403431 Ref: library/configparser configparser ConfigParser4403492 Ref: 4aa4403492 Ref: library/configparser configparser ConfigParser defaults4407295 Ref: 1b224407295 Ref: library/configparser configparser ConfigParser sections4407395 Ref: 1b234407395 Ref: library/configparser configparser ConfigParser add_section4407538 Ref: c044407538 Ref: library/configparser configparser ConfigParser has_section4408027 Ref: 1b244408027 Ref: library/configparser configparser ConfigParser options4408203 Ref: 1b254408203 Ref: library/configparser configparser ConfigParser has_option4408313 Ref: 1b264408313 Ref: library/configparser configparser ConfigParser read4408613 Ref: 1b274408613 Ref: library/configparser configparser ConfigParser read_file4410338 Ref: 1b284410338 Ref: library/configparser configparser ConfigParser read_string4410819 Ref: 1b2a4410819 Ref: library/configparser configparser ConfigParser read_dict4411166 Ref: 1b214411166 Ref: library/configparser configparser ConfigParser get4411861 Ref: c024411861 Ref: library/configparser configparser ConfigParser getint4412817 Ref: 1b154412817 Ref: library/configparser configparser ConfigParser getfloat4413105 Ref: 1b164413105 Ref: library/configparser configparser ConfigParser getboolean4413408 Ref: 1b144413408 Ref: library/configparser configparser ConfigParser items4414138 Ref: 1b2b4414138 Ref: library/configparser configparser ConfigParser set4414776 Ref: c034414776 Ref: library/configparser configparser ConfigParser write4415061 Ref: 1b1a4415061 Ref: library/configparser configparser ConfigParser remove_option4415502 Ref: 1b2d4415502 Ref: library/configparser configparser ConfigParser remove_section4415816 Ref: 1b2e4415816 Ref: library/configparser configparser ConfigParser optionxform4416028 Ref: 1b204416028 Ref: library/configparser configparser ConfigParser readfp4417001 Ref: 1b294417001 Ref: library/configparser configparser MAX_INTERPOLATION_DEPTH4417769 Ref: 1b2f4417769 Node: RawConfigParser Objects4417995 Ref: library/configparser id134418148 Ref: 1b304418148 Ref: library/configparser rawconfigparser-objects4418148 Ref: 1b314418148 Ref: library/configparser configparser RawConfigParser4418217 Ref: 8714418217 Ref: library/configparser configparser RawConfigParser add_section4419199 Ref: 1b324419199 Ref: library/configparser configparser RawConfigParser set4419673 Ref: 1b334419673 Node: Exceptions<5>4420500 Ref: library/configparser exceptions4420624 Ref: 1b344420624 Ref: library/configparser configparser Error4420667 Ref: 1b354420667 Ref: library/configparser configparser NoSectionError4420769 Ref: 1b2c4420769 Ref: library/configparser configparser DuplicateSectionError4420875 Ref: c054420875 Ref: library/configparser configparser DuplicateOptionError4421287 Ref: c064421287 Ref: library/configparser configparser NoOptionError4421647 Ref: 1b364421647 Ref: library/configparser configparser InterpolationError4421781 Ref: 1b374421781 Ref: library/configparser configparser InterpolationDepthError4421926 Ref: 1b384421926 Ref: library/configparser configparser InterpolationMissingOptionError4422186 Ref: 1b394422186 Ref: library/configparser configparser InterpolationSyntaxError4422375 Ref: 1b3a4422375 Ref: library/configparser configparser MissingSectionHeaderError4422603 Ref: 1b3b4422603 Ref: library/configparser configparser ParsingError4422748 Ref: 1b3c4422748 Node: netrc — netrc file processing4423005 Ref: library/netrc doc4423182 Ref: 1b3d4423182 Ref: library/netrc module-netrc4423182 Ref: be4423182 Ref: library/netrc netrc-netrc-file-processing4423182 Ref: 1b3e4423182 Ref: library/netrc netrc netrc4423501 Ref: 1b3f4423501 Ref: library/netrc netrc NetrcParseError4424762 Ref: 1b404424762 Ref: netrc — netrc file processing-Footnote-14425232 Node: netrc Objects4425296 Ref: library/netrc id14425377 Ref: 1b414425377 Ref: library/netrc netrc-objects4425377 Ref: 1b424425377 Ref: library/netrc netrc netrc authenticators4425482 Ref: 1b434425482 Ref: library/netrc netrc netrc __repr__4425828 Ref: 1b444425828 Ref: library/netrc netrc netrc hosts4426052 Ref: 1b454426052 Ref: library/netrc netrc netrc macros4426250 Ref: 1b464426250 Node: xdrlib — Encode and decode XDR data4426656 Ref: library/xdrlib doc4426843 Ref: 1b474426843 Ref: library/xdrlib module-xdrlib4426843 Ref: 1324426843 Ref: library/xdrlib xdrlib-encode-and-decode-xdr-data4426843 Ref: 1b484426843 Ref: library/xdrlib xdrlib Packer4427448 Ref: 1b494427448 Ref: library/xdrlib xdrlib Unpacker4427631 Ref: 1b4a4427631 Ref: xdrlib — Encode and decode XDR data-Footnote-14428284 Ref: xdrlib — Encode and decode XDR data-Footnote-24428349 Ref: xdrlib — Encode and decode XDR data-Footnote-34428398 Ref: xdrlib — Encode and decode XDR data-Footnote-44428447 Ref: xdrlib — Encode and decode XDR data-Footnote-54428496 Node: Packer Objects4428545 Ref: library/xdrlib packer-objects4428658 Ref: 1b4b4428658 Ref: library/xdrlib xdr-packer-objects4428658 Ref: 1b4c4428658 Ref: library/xdrlib xdrlib Packer get_buffer4428766 Ref: 1b4d4428766 Ref: library/xdrlib xdrlib Packer reset4428851 Ref: 1b4e4428851 Ref: library/xdrlib xdrlib Packer pack_float4429287 Ref: 1b4f4429287 Ref: library/xdrlib xdrlib Packer pack_double4429390 Ref: 1b504429390 Ref: library/xdrlib xdrlib Packer pack_fstring4429566 Ref: 1b514429566 Ref: library/xdrlib xdrlib Packer pack_fopaque4429817 Ref: 1b524429817 Ref: library/xdrlib xdrlib Packer pack_string4429953 Ref: 1b534429953 Ref: library/xdrlib xdrlib Packer pack_opaque4430172 Ref: 1b544430172 Ref: library/xdrlib xdrlib Packer pack_bytes4430306 Ref: 1b554430306 Ref: library/xdrlib xdrlib Packer pack_list4430490 Ref: 1b564430490 Ref: library/xdrlib xdrlib Packer pack_farray4431180 Ref: 1b574431180 Ref: library/xdrlib xdrlib Packer pack_array4431542 Ref: 1b584431542 Node: Unpacker Objects4431793 Ref: library/xdrlib unpacker-objects4431928 Ref: 1b594431928 Ref: library/xdrlib xdr-unpacker-objects4431928 Ref: 1b5a4431928 Ref: library/xdrlib xdrlib Unpacker reset4432044 Ref: 1b5b4432044 Ref: library/xdrlib xdrlib Unpacker get_position4432133 Ref: 1b5c4432133 Ref: library/xdrlib xdrlib Unpacker set_position4432233 Ref: 1b5d4432233 Ref: library/xdrlib xdrlib Unpacker get_buffer4432442 Ref: 1b5e4432442 Ref: library/xdrlib xdrlib Unpacker done4432536 Ref: 1b5f4432536 Ref: library/xdrlib xdrlib Unpacker unpack_float4432923 Ref: 1b614432923 Ref: library/xdrlib xdrlib Unpacker unpack_double4433017 Ref: 1b624433017 Ref: library/xdrlib xdrlib Unpacker unpack_fstring4433234 Ref: 1b634433234 Ref: library/xdrlib xdrlib Unpacker unpack_fopaque4433445 Ref: 1b644433445 Ref: library/xdrlib xdrlib Unpacker unpack_string4433595 Ref: 1b654433595 Ref: library/xdrlib xdrlib Unpacker unpack_opaque4433832 Ref: 1b664433832 Ref: library/xdrlib xdrlib Unpacker unpack_bytes4433982 Ref: 1b674433982 Ref: library/xdrlib xdrlib Unpacker unpack_list4434183 Ref: 1b684434183 Ref: library/xdrlib xdrlib Unpacker unpack_farray4434588 Ref: 1b694434588 Ref: library/xdrlib xdrlib Unpacker unpack_array4434859 Ref: 1b6a4434859 Node: Exceptions<6>4435134 Ref: library/xdrlib exceptions4435246 Ref: 1b6b4435246 Ref: library/xdrlib xdr-exceptions4435246 Ref: 1b6c4435246 Ref: library/xdrlib xdrlib Error4435344 Ref: 1b604435344 Ref: library/xdrlib xdrlib ConversionError4435511 Ref: 1b6d4435511 Node: plistlib — Generate and parse Mac OS X plist files4435902 Ref: library/plistlib doc4436049 Ref: 1b6e4436049 Ref: library/plistlib module-plistlib4436049 Ref: cf4436049 Ref: library/plistlib plistlib-generate-and-parse-mac-os-x-plist-files4436049 Ref: 1b6f4436049 Ref: library/plistlib plistlib load4437426 Ref: 88b4437426 Ref: library/plistlib plistlib loads4438594 Ref: 88d4438594 Ref: library/plistlib plistlib dump4438834 Ref: 88c4438834 Ref: library/plistlib plistlib dumps4439932 Ref: 88e4439932 Ref: library/plistlib plistlib readPlist4440269 Ref: 47f4440269 Ref: library/plistlib plistlib writePlist4440907 Ref: 9454440907 Ref: library/plistlib plistlib readPlistFromBytes4441166 Ref: 4804441166 Ref: library/plistlib plistlib writePlistToBytes4441595 Ref: 9464441595 Ref: library/plistlib plistlib Data4441823 Ref: 9474441823 Ref: library/plistlib plistlib UID4442240 Ref: 2104442240 Ref: library/plistlib plistlib FMT_XML4442644 Ref: 88f4442644 Ref: library/plistlib plistlib FMT_BINARY4442736 Ref: 8904442736 Ref: plistlib — Generate and parse Mac OS X plist files-Footnote-14442904 Ref: plistlib — Generate and parse Mac OS X plist files-Footnote-24442971 Node: Examples<8>4443070 Ref: library/plistlib examples4443170 Ref: 1b704443170 Node: Cryptographic Services4443912 Ref: library/crypto doc4444061 Ref: 1b714444061 Ref: library/crypto crypto4444061 Ref: 1b724444061 Ref: library/crypto cryptographic-services4444061 Ref: 1b734444061 Node: hashlib — Secure hashes and message digests4444546 Ref: library/hashlib doc4444708 Ref: 1b744444708 Ref: library/hashlib hashlib-secure-hashes-and-message-digests4444708 Ref: 1b754444708 Ref: library/hashlib module-hashlib4444708 Ref: 8d4444708 Ref: hashlib — Secure hashes and message digests-Footnote-14445729 Ref: hashlib — Secure hashes and message digests-Footnote-24445795 Node: Hash algorithms4445844 Ref: library/hashlib hash-algorithms4445979 Ref: 1b764445979 Ref: library/hashlib id14445979 Ref: 1b774445979 Ref: library/hashlib hashlib new4448225 Ref: 1b784448225 Ref: library/hashlib hashlib algorithms_guaranteed4448903 Ref: cfc4448903 Ref: library/hashlib hashlib algorithms_available4449236 Ref: cfd4449236 Ref: library/hashlib hashlib hash digest_size4449772 Ref: 1b794449772 Ref: library/hashlib hashlib hash block_size4449847 Ref: 1b7a4449847 Ref: library/hashlib hashlib hash name4449981 Ref: 8524449981 Ref: library/hashlib hashlib hash update4450402 Ref: 1b7b4450402 Ref: library/hashlib hashlib hash digest4450889 Ref: 1b7c4450889 Ref: library/hashlib hashlib hash hexdigest4451129 Ref: 1b7d4451129 Ref: library/hashlib hashlib hash copy4451400 Ref: 1b7e4451400 Node: SHAKE variable length digests4451587 Ref: library/hashlib shake-variable-length-digests4451745 Ref: 1b7f4451745 Ref: library/hashlib hashlib shake digest4452074 Ref: 1b804452074 Ref: library/hashlib hashlib shake hexdigest4452298 Ref: 1b814452298 Node: Key derivation4452576 Ref: library/hashlib key-derivation4452725 Ref: 1b824452725 Ref: library/hashlib hashlib pbkdf2_hmac4453036 Ref: 7e64453036 Ref: library/hashlib hashlib scrypt4454467 Ref: 4d24454467 Ref: Key derivation-Footnote-14455235 Ref: Key derivation-Footnote-24455297 Node: BLAKE24455346 Ref: library/hashlib blake24455457 Ref: 1b834455457 Ref: BLAKE2-Footnote-14456179 Ref: BLAKE2-Footnote-24456206 Ref: BLAKE2-Footnote-34456255 Node: Creating hash objects4456333 Ref: library/hashlib creating-hash-objects4456418 Ref: 1b844456418 Ref: library/hashlib hashlib blake2b4456545 Ref: 54c4456545 Ref: library/hashlib hashlib blake2s4456749 Ref: 54d4456749 Ref: Creating hash objects-Footnote-14459681 Node: Constants<5>4459728 Ref: library/hashlib constants4459833 Ref: 1b854459833 Ref: library/hashlib hashlib blake2b SALT_SIZE4459872 Ref: 1b864459872 Ref: library/hashlib hashlib blake2s SALT_SIZE4459901 Ref: 1b874459901 Ref: library/hashlib hashlib blake2b PERSON_SIZE4459986 Ref: 1b884459986 Ref: library/hashlib hashlib blake2s PERSON_SIZE4460017 Ref: 1b894460017 Ref: library/hashlib hashlib blake2b MAX_KEY_SIZE4460122 Ref: 1b8a4460122 Ref: library/hashlib hashlib blake2s MAX_KEY_SIZE4460154 Ref: 1b8b4460154 Ref: library/hashlib hashlib blake2b MAX_DIGEST_SIZE4460205 Ref: 1b8c4460205 Ref: library/hashlib hashlib blake2s MAX_DIGEST_SIZE4460240 Ref: 1b8d4460240 Node: Examples<9>4460331 Ref: library/hashlib examples4460422 Ref: 1b8e4460422 Node: Simple hashing4460596 Ref: library/hashlib simple-hashing4460695 Ref: 1b8f4460695 Node: Using different digest sizes4462117 Ref: library/hashlib using-different-digest-sizes4462238 Ref: 1b904462238 Node: Keyed hashing4463379 Ref: library/hashlib keyed-hashing4463504 Ref: 1b914463504 Ref: Keyed hashing-Footnote-14465515 Node: Randomized hashing4465593 Ref: library/hashlib randomized-hashing4465705 Ref: 1b924465705 Ref: Randomized hashing-Footnote-14468309 Ref: Randomized hashing-Footnote-24468376 Node: Personalization4468407 Ref: library/hashlib personalization4468515 Ref: 1b934468515 Ref: Personalization-Footnote-14470510 Node: Tree mode4470578 Ref: library/hashlib tree-mode4470659 Ref: 1b944470659 Node: Credits4471910 Ref: library/hashlib credits4471980 Ref: 1b954471980 Ref: Credits-Footnote-14474214 Ref: Credits-Footnote-24474241 Ref: Credits-Footnote-34474310 Ref: Credits-Footnote-44474344 Ref: Credits-Footnote-54474381 Ref: Credits-Footnote-64474424 Node: hmac — Keyed-Hashing for Message Authentication4474467 Ref: library/hmac doc4474701 Ref: 1b964474701 Ref: library/hmac hmac-keyed-hashing-for-message-authentication4474701 Ref: 1b974474701 Ref: library/hmac module-hmac4474701 Ref: 8f4474701 Ref: library/hmac hmac new4474993 Ref: 8544474993 Ref: library/hmac hmac digest4475920 Ref: 3904475920 Ref: library/hmac hmac HMAC update4476561 Ref: 8554476561 Ref: library/hmac hmac HMAC digest4476909 Ref: 1b984476909 Ref: library/hmac hmac HMAC hexdigest4477518 Ref: 1b994477518 Ref: library/hmac hmac HMAC copy4478106 Ref: 1b9a4478106 Ref: library/hmac hmac HMAC digest_size4478344 Ref: 8584478344 Ref: library/hmac hmac HMAC block_size4478431 Ref: 8564478431 Ref: library/hmac hmac HMAC name4478551 Ref: 8574478551 Ref: library/hmac hmac compare_digest4478744 Ref: a0c4478744 Ref: hmac — Keyed-Hashing for Message Authentication-Footnote-14479566 Ref: hmac — Keyed-Hashing for Message Authentication-Footnote-24479629 Node: secrets — Generate secure random numbers for managing secrets4479678 Ref: library/secrets doc4479858 Ref: 1b9b4479858 Ref: library/secrets module-secrets4479858 Ref: e44479858 Ref: library/secrets secrets-generate-secure-random-numbers-for-managing-secrets4479858 Ref: 1b9c4479858 Ref: secrets — Generate secure random numbers for managing secrets-Footnote-14480722 Ref: secrets — Generate secure random numbers for managing secrets-Footnote-24480788 Node: Random numbers4480837 Ref: library/secrets random-numbers4480977 Ref: 1b9d4480977 Ref: library/secrets secrets SystemRandom4481150 Ref: 1b9e4481150 Ref: library/secrets secrets choice4481367 Ref: 1b9f4481367 Ref: library/secrets secrets randbelow4481474 Ref: 1ba04481474 Ref: library/secrets secrets randbits4481560 Ref: 1ba14481560 Node: Generating tokens4481638 Ref: library/secrets generating-tokens4481802 Ref: 1ba24481802 Ref: library/secrets secrets token_bytes4482021 Ref: 1ba34482021 Ref: library/secrets secrets token_hex4482314 Ref: 1ba44482314 Ref: library/secrets secrets token_urlsafe4482650 Ref: 1ba54482650 Node: How many bytes should tokens use?4483080 Ref: library/secrets how-many-bytes-should-tokens-use4483167 Ref: 1ba64483167 Ref: How many bytes should tokens use?-Footnote-14484194 Node: Other functions4484251 Ref: library/secrets other-functions4484427 Ref: 1ba74484427 Ref: library/secrets secrets compare_digest4484478 Ref: 1ba84484478 Ref: Other functions-Footnote-14484771 Node: Recipes and best practices4484828 Ref: library/secrets recipes-and-best-practices4484978 Ref: 1ba94484978 Ref: Recipes and best practices-Footnote-14486718 Ref: Recipes and best practices-Footnote-24486773 Node: Generic Operating System Services4486803 Ref: library/allos doc4486960 Ref: 1baa4486960 Ref: library/allos allos4486960 Ref: 1bab4486960 Ref: library/allos generic-operating-system-services4486960 Ref: 1bac4486960 Node: os — Miscellaneous operating system interfaces4488511 Ref: library/os doc4488680 Ref: 1bad4488680 Ref: library/os module-os4488680 Ref: c44488680 Ref: library/os os-miscellaneous-operating-system-interfaces4488680 Ref: 1bae4488680 Ref: library/os os error4490472 Ref: 1baf4490472 Ref: library/os os name4490560 Ref: 1bb04490560 Ref: library/os os-filenames4491003 Ref: 1ae04491003 Ref: os — Miscellaneous operating system interfaces-Footnote-14491408 Node: File Names Command Line Arguments and Environment Variables4491469 Ref: library/os file-names-command-line-arguments-and-environment-variables4491640 Ref: 1bb14491640 Ref: library/os filesystem-encoding4491640 Ref: 1bb24491640 Node: Process Parameters4492644 Ref: library/os os-procinfo4492844 Ref: 1bb34492844 Ref: library/os process-parameters4492844 Ref: 1bb44492844 Ref: library/os os ctermid4492998 Ref: 1bb54492998 Ref: library/os os environ4493154 Ref: b374493154 Ref: library/os os environb4495045 Ref: b944495045 Ref: library/os os fsencode4495631 Ref: 4ef4495631 Ref: library/os os fsdecode4496061 Ref: 4ee4496061 Ref: library/os os fspath4496495 Ref: 4ed4496495 Ref: library/os os PathLike4496906 Ref: 4eb4496906 Ref: library/os os PathLike __fspath__4497083 Ref: 4ec4497083 Ref: library/os os getenv4497353 Ref: 1bb84497353 Ref: library/os os getenvb4497832 Ref: b934497832 Ref: library/os os get_exec_path4498217 Ref: 1bb94498217 Ref: library/os os getegid4498596 Ref: 1bba4498596 Ref: library/os os geteuid4498826 Ref: 1bbb4498826 Ref: library/os os getgid4498949 Ref: 1bbc4498949 Ref: library/os os getgrouplist4499070 Ref: a5b4499070 Ref: library/os os getgroups4499383 Ref: 1bbd4499383 Ref: library/os os getlogin4500608 Ref: 1bbf4500608 Ref: library/os os getpgid4501089 Ref: 1bc14501089 Ref: library/os os getpgrp4501313 Ref: 1bc24501313 Ref: library/os os getpid4501430 Ref: 1bc34501430 Ref: library/os os getppid4501495 Ref: 1bc44501495 Ref: library/os os getpriority4501864 Ref: a464501864 Ref: library/os os PRIO_PROCESS4502495 Ref: 1bc54502495 Ref: library/os os PRIO_PGRP4502521 Ref: 1bc64502521 Ref: library/os os PRIO_USER4502544 Ref: 1bc74502544 Ref: library/os os getresuid4502729 Ref: cab4502729 Ref: library/os os getresgid4502939 Ref: caa4502939 Ref: library/os os getuid4503150 Ref: 1bc84503150 Ref: library/os os initgroups4503267 Ref: cae4503267 Ref: library/os os putenv4503554 Ref: 1bb64503554 Ref: library/os os setegid4504510 Ref: 1bca4504510 Ref: library/os os seteuid4504635 Ref: 1bcb4504635 Ref: library/os os setgid4504759 Ref: 1bcc4504759 Ref: library/os os setgroups4504871 Ref: 1bbe4504871 Ref: library/os os setpgrp4505518 Ref: 1bcd4505518 Ref: library/os os setpgid4505753 Ref: 1bce4505753 Ref: library/os os setpriority4506016 Ref: a474506016 Ref: library/os os setregid4506792 Ref: 1bcf4506792 Ref: library/os os setresgid4506934 Ref: cac4506934 Ref: library/os os setresuid4507117 Ref: cad4507117 Ref: library/os os setreuid4507299 Ref: 1bd04507299 Ref: library/os os getsid4507440 Ref: 1bd14507440 Ref: library/os os setsid4507597 Ref: 1bd24507597 Ref: library/os os setuid4507751 Ref: 1bd34507751 Ref: library/os os strerror4507863 Ref: 1bd44507863 Ref: library/os os supports_bytes_environ4508106 Ref: b924508106 Ref: library/os os umask4508271 Ref: 1bd54508271 Ref: library/os os uname4508369 Ref: a5d4508369 Ref: library/os os unsetenv4509420 Ref: d434509420 Node: File Object Creation4510156 Ref: library/os file-object-creation4510323 Ref: 1bd74510323 Ref: library/os os-newstreams4510323 Ref: 1bd84510323 Ref: library/os os fdopen4510498 Ref: 10d24510498 Node: File Descriptor Operations4510825 Ref: library/os file-descriptor-operations4510995 Ref: 1bd94510995 Ref: library/os os-fd-ops4510995 Ref: 1bda4510995 Ref: library/os os close4511836 Ref: 3d24511836 Ref: library/os os closerange4512282 Ref: 1bde4512282 Ref: library/os os copy_file_range4512628 Ref: 1bdf4512628 Ref: library/os os device_encoding4513654 Ref: 1be14513654 Ref: library/os os dup4513847 Ref: 1be24513847 Ref: library/os os dup24514216 Ref: 3be4514216 Ref: library/os os fchmod4514675 Ref: 65c4514675 Ref: library/os os fchown4515080 Ref: 65d4515080 Ref: library/os os fdatasync4515539 Ref: 65e4515539 Ref: library/os os fpathconf4515769 Ref: 1be34515769 Ref: library/os os fstat4516798 Ref: 65f4516798 Ref: library/os os fstatvfs4517058 Ref: 6604517058 Ref: library/os os fsync4517331 Ref: 6614517331 Ref: library/os os ftruncate4517815 Ref: 6624517815 Ref: library/os os get_blocking4518255 Ref: 7214518255 Ref: library/os os isatty4518594 Ref: 1be64518594 Ref: library/os os lockf4518745 Ref: a5a4518745 Ref: library/os os F_LOCK4519260 Ref: 1be74519260 Ref: library/os os F_TLOCK4519280 Ref: 1be84519280 Ref: library/os os F_ULOCK4519301 Ref: 1be94519301 Ref: library/os os F_TEST4519322 Ref: 1bea4519322 Ref: library/os os lseek4519475 Ref: a5e4519475 Ref: library/os os SEEK_SET4519945 Ref: d944519945 Ref: library/os os SEEK_CUR4519967 Ref: d954519967 Ref: library/os os SEEK_END4519989 Ref: d964519989 Ref: library/os os open4520250 Ref: 6654520250 Ref: library/os os O_RDONLY4522315 Ref: 1beb4522315 Ref: library/os os O_WRONLY4522337 Ref: 1bec4522337 Ref: library/os os O_RDWR4522359 Ref: 1bee4522359 Ref: library/os os O_APPEND4522379 Ref: 1bef4522379 Ref: library/os os O_CREAT4522401 Ref: 1bf04522401 Ref: library/os os O_EXCL4522422 Ref: 192a4522422 Ref: library/os os O_TRUNC4522442 Ref: 1bf14522442 Ref: library/os os O_DSYNC4522525 Ref: 1bf24522525 Ref: library/os os O_RSYNC4522546 Ref: 1bf34522546 Ref: library/os os O_SYNC4522567 Ref: 1bf44522567 Ref: library/os os O_NDELAY4522587 Ref: 1bf54522587 Ref: library/os os O_NONBLOCK4522609 Ref: 7234522609 Ref: library/os os O_NOCTTY4522633 Ref: 1bf64522633 Ref: library/os os O_CLOEXEC4522655 Ref: 9c34522655 Ref: library/os os O_BINARY4522799 Ref: 1bed4522799 Ref: library/os os O_NOINHERIT4522821 Ref: 1bf74522821 Ref: library/os os O_SHORT_LIVED4522846 Ref: 1bf84522846 Ref: library/os os O_TEMPORARY4522873 Ref: 1bf94522873 Ref: library/os os O_RANDOM4522898 Ref: 1bfa4522898 Ref: library/os os O_SEQUENTIAL4522920 Ref: 1bfb4522920 Ref: library/os os O_TEXT4522946 Ref: 1bfc4522946 Ref: library/os os O_ASYNC4523024 Ref: 1bfd4523024 Ref: library/os os O_DIRECT4523045 Ref: 1bfe4523045 Ref: library/os os O_DIRECTORY4523067 Ref: 1bff4523067 Ref: library/os os O_NOFOLLOW4523092 Ref: 1c004523092 Ref: library/os os O_NOATIME4523116 Ref: 1c014523116 Ref: library/os os O_PATH4523139 Ref: 8834523139 Ref: library/os os O_TMPFILE4523159 Ref: 8844523159 Ref: library/os os O_SHLOCK4523182 Ref: d974523182 Ref: library/os os O_EXLOCK4523204 Ref: d984523204 Ref: library/os os openpty4523495 Ref: 1c024523495 Ref: library/os os pipe4523944 Ref: 1bdc4523944 Ref: library/os os pipe24524283 Ref: a2e4524283 Ref: library/os os posix_fallocate4524673 Ref: 6674524673 Ref: library/os os posix_fadvise4524930 Ref: 6664524930 Ref: library/os os POSIX_FADV_NORMAL4525531 Ref: 1c034525531 Ref: library/os os POSIX_FADV_SEQUENTIAL4525562 Ref: 1c044525562 Ref: library/os os POSIX_FADV_RANDOM4525597 Ref: 1c054525597 Ref: library/os os POSIX_FADV_NOREUSE4525628 Ref: 1c064525628 Ref: library/os os POSIX_FADV_WILLNEED4525660 Ref: 1c074525660 Ref: library/os os POSIX_FADV_DONTNEED4525693 Ref: 1c084525693 Ref: library/os os pread4525927 Ref: 3b94525927 Ref: library/os os preadv4526313 Ref: 3b74526313 Ref: library/os os RWF_NOWAIT4527367 Ref: 1c0a4527367 Ref: library/os os RWF_HIPRI4527875 Ref: 1c094527875 Ref: library/os os pwrite4528272 Ref: 3bc4528272 Ref: library/os os pwritev4528555 Ref: 3ba4528555 Ref: library/os os RWF_DSYNC4529572 Ref: 1c0d4529572 Ref: library/os os RWF_SYNC4529847 Ref: 1c0e4529847 Ref: library/os os read4530120 Ref: 6684530120 Ref: library/os os sendfile4531061 Ref: 3594531061 Ref: library/os os set_blocking4532412 Ref: 7224532412 Ref: library/os os SF_NODISKIO4532777 Ref: 1c0f4532777 Ref: library/os os SF_MNOWAIT4532802 Ref: 1c104532802 Ref: library/os os SF_SYNC4532826 Ref: 1c114532826 Ref: library/os os readv4533011 Ref: 3b84533011 Ref: library/os os tcgetpgrp4533626 Ref: 1c124533626 Ref: library/os os tcsetpgrp4533840 Ref: 1c134533840 Ref: library/os os ttyname4534068 Ref: 1c144534068 Ref: library/os os write4534318 Ref: 66e4534318 Ref: library/os os writev4535166 Ref: 3bb4535166 Ref: File Descriptor Operations-Footnote-14535859 Ref: File Descriptor Operations-Footnote-24535908 Ref: File Descriptor Operations-Footnote-34535971 Ref: File Descriptor Operations-Footnote-44536020 Node: Querying the size of a terminal4536069 Ref: library/os querying-the-size-of-a-terminal4536203 Ref: 1c154536203 Ref: library/os terminal-size4536203 Ref: 1c164536203 Ref: library/os os get_terminal_size4536307 Ref: a494536307 Ref: library/os os terminal_size4536943 Ref: 195f4536943 Ref: library/os os terminal_size columns4537064 Ref: 1c174537064 Ref: library/os os terminal_size lines4537148 Ref: 1c184537148 Node: Inheritance of File Descriptors4537231 Ref: library/os fd-inheritance4537365 Ref: 7fa4537365 Ref: library/os inheritance-of-file-descriptors4537365 Ref: 1c194537365 Ref: library/os os get_inheritable4538328 Ref: 7fb4538328 Ref: library/os os set_inheritable4538455 Ref: 7fc4538455 Ref: library/os os get_handle_inheritable4538578 Ref: 7fd4538578 Ref: library/os os set_handle_inheritable4538743 Ref: 7fe4538743 Node: Files and Directories4538909 Ref: library/os files-and-directories4539077 Ref: 1c1b4539077 Ref: library/os os-file-dir4539077 Ref: 1bb74539077 Ref: library/os path-fd4539226 Ref: 3b54539226 Ref: library/os dir-fd4540170 Ref: a2f4540170 Ref: library/os follow-symlinks4540885 Ref: a304540885 Ref: library/os os access4541469 Ref: a314541469 Ref: library/os os F_OK4544017 Ref: 1c1c4544017 Ref: library/os os R_OK4544035 Ref: 1c1d4544035 Ref: library/os os W_OK4544053 Ref: 1c1e4544053 Ref: library/os os X_OK4544071 Ref: 1c1f4544071 Ref: library/os os chdir4544260 Ref: a3f4544260 Ref: library/os os chflags4544932 Ref: a324544932 Ref: library/os os chmod4545997 Ref: a334545997 Ref: library/os os chown4547753 Ref: a344547753 Ref: library/os os chroot4548645 Ref: 1c214548645 Ref: library/os os fchdir4548850 Ref: 65b4548850 Ref: library/os os getcwd4549253 Ref: 188d4549253 Ref: library/os os getcwdb4549347 Ref: 2b84549347 Ref: library/os os lchflags4549655 Ref: 1c224549655 Ref: library/os os lchmod4550133 Ref: 1c234550133 Ref: library/os os lchown4550702 Ref: 1c244550702 Ref: library/os os link4551213 Ref: a354551213 Ref: library/os os listdir4551991 Ref: a414551991 Ref: library/os os lstat4553467 Ref: 1f24553467 Ref: library/os os mkdir4554603 Ref: a364554603 Ref: library/os mkdir-modebits4554807 Ref: 1c254554807 Ref: library/os os makedirs4555655 Ref: 3bd4555655 Ref: library/os os mkfifo4557374 Ref: 6634557374 Ref: library/os os mknod4558259 Ref: 6644558259 Ref: library/os os major4559129 Ref: 1c284559129 Ref: library/os os minor4559297 Ref: 1c294559297 Ref: library/os os makedev4559465 Ref: 1c274559465 Ref: library/os os pathconf4559586 Ref: a424559586 Ref: library/os os pathconf_names4560683 Ref: 1c2a4560683 Ref: library/os os readlink4561005 Ref: 1f34561005 Ref: library/os os remove4562503 Ref: a374562503 Ref: library/os os removedirs4563356 Ref: 1c2b4563356 Ref: library/os os rename4564198 Ref: a384564198 Ref: library/os os renames4565692 Ref: 1c2c4565692 Ref: library/os os replace4566479 Ref: a394566479 Ref: library/os os rmdir4567346 Ref: a3a4567346 Ref: library/os os scandir4567981 Ref: 25f4567981 Ref: library/os os scandir close4569757 Ref: 5674569757 Ref: library/os os DirEntry4571281 Ref: 4f14571281 Ref: library/os os DirEntry name4572466 Ref: 1c2f4572466 Ref: library/os os DirEntry path4572837 Ref: 1c304572837 Ref: library/os os DirEntry inode4573572 Ref: 1c314573572 Ref: library/os os DirEntry is_dir4573931 Ref: 1c2d4573931 Ref: library/os os DirEntry is_file4575366 Ref: 6554575366 Ref: library/os os DirEntry is_symlink4576089 Ref: 1c324576089 Ref: library/os os DirEntry stat4576940 Ref: 1c2e4576940 Ref: library/os os stat4578360 Ref: 1f14578360 Ref: library/os os stat_result4580942 Ref: 188f4580942 Ref: library/os os stat_result st_mode4581192 Ref: 1c334581192 Ref: library/os os stat_result st_ino4581287 Ref: 1c344581287 Ref: library/os os stat_result st_dev4581536 Ref: 1c354581536 Ref: library/os os stat_result st_nlink4581628 Ref: 1c364581628 Ref: library/os os stat_result st_uid4581691 Ref: 1c374581691 Ref: library/os os stat_result st_gid4581765 Ref: 1c384581765 Ref: library/os os stat_result st_size4581840 Ref: 1c394581840 Ref: library/os os stat_result st_atime4582094 Ref: 1c3a4582094 Ref: library/os os stat_result st_mtime4582184 Ref: 1a204582184 Ref: library/os os stat_result st_ctime4582288 Ref: 1c3b4582288 Ref: library/os os stat_result st_atime_ns4582485 Ref: 1c3c4582485 Ref: library/os os stat_result st_mtime_ns4582606 Ref: 1c3d4582606 Ref: library/os os stat_result st_ctime_ns4582741 Ref: 1c3e4582741 Ref: library/os os stat_result st_blocks4584191 Ref: 1c3f4584191 Ref: library/os os stat_result st_blksize4584365 Ref: 1c404584365 Ref: library/os os stat_result st_rdev4584567 Ref: 1c414584567 Ref: library/os os stat_result st_flags4584642 Ref: 1c424584642 Ref: library/os os stat_result st_gen4584867 Ref: 1c434584867 Ref: library/os os stat_result st_birthtime4584930 Ref: 1c444584930 Ref: library/os os stat_result st_fstype4585085 Ref: 3bf4585085 Ref: library/os os stat_result st_rsize4585293 Ref: 1c454585293 Ref: library/os os stat_result st_creator4585357 Ref: 1c464585357 Ref: library/os os stat_result st_type4585421 Ref: 1c474585421 Ref: library/os os stat_result st_file_attributes4585543 Ref: 7204585543 Ref: library/os os stat_result st_reparse_tag4585850 Ref: 1c484585850 Ref: library/os os statvfs4587700 Ref: a434587700 Ref: library/os os supports_dir_fd4589722 Ref: a3e4589722 Ref: library/os os supports_effective_ids4590881 Ref: a454590881 Ref: library/os os supports_fd4591619 Ref: a444591619 Ref: library/os os supports_follow_symlinks4592441 Ref: 19484592441 Ref: library/os os symlink4593575 Ref: a3b4593575 Ref: library/os os sync4595227 Ref: a594595227 Ref: library/os os truncate4595358 Ref: 7244595358 Ref: library/os os unlink4595878 Ref: a3c4595878 Ref: library/os os utime4596402 Ref: a3d4596402 Ref: library/os os walk4598265 Ref: 6544598265 Ref: library/os os fwalk4603311 Ref: 3b44603311 Ref: library/os os memfd_create4605748 Ref: 1f04605748 Ref: library/os os MFD_CLOEXEC4606621 Ref: 1c494606621 Ref: library/os os MFD_ALLOW_SEALING4606646 Ref: 1c4a4606646 Ref: library/os os MFD_HUGETLB4606677 Ref: 1c4b4606677 Ref: library/os os MFD_HUGE_SHIFT4606702 Ref: 1c4c4606702 Ref: library/os os MFD_HUGE_MASK4606730 Ref: 1c4d4606730 Ref: library/os os MFD_HUGE_64KB4606757 Ref: 1c4e4606757 Ref: library/os os MFD_HUGE_512KB4606784 Ref: 1c4f4606784 Ref: library/os os MFD_HUGE_1MB4606812 Ref: 1c504606812 Ref: library/os os MFD_HUGE_2MB4606838 Ref: 1c514606838 Ref: library/os os MFD_HUGE_8MB4606864 Ref: 1c524606864 Ref: library/os os MFD_HUGE_16MB4606890 Ref: 1c534606890 Ref: library/os os MFD_HUGE_32MB4606917 Ref: 1c544606917 Ref: library/os os MFD_HUGE_256MB4606944 Ref: 1c554606944 Ref: library/os os MFD_HUGE_512MB4606972 Ref: 1c564606972 Ref: library/os os MFD_HUGE_1GB4607000 Ref: 1c574607000 Ref: library/os os MFD_HUGE_2GB4607026 Ref: 1c584607026 Ref: library/os os MFD_HUGE_16GB4607052 Ref: 1c594607052 Ref: Files and Directories-Footnote-14607391 Ref: Files and Directories-Footnote-24607440 Ref: Files and Directories-Footnote-34607483 Ref: Files and Directories-Footnote-44607562 Ref: Files and Directories-Footnote-54607643 Ref: Files and Directories-Footnote-64607732 Ref: Files and Directories-Footnote-74607821 Node: Linux extended attributes4607879 Ref: library/os linux-extended-attributes4607962 Ref: 1c5a4607962 Ref: library/os os getxattr4608104 Ref: a4b4608104 Ref: library/os os listxattr4608763 Ref: a4c4608763 Ref: library/os os removexattr4609370 Ref: a4d4609370 Ref: library/os os setxattr4610031 Ref: a4e4610031 Ref: library/os os XATTR_SIZE_MAX4611241 Ref: 1c5d4611241 Ref: library/os os XATTR_CREATE4611377 Ref: 1c5c4611377 Ref: library/os os XATTR_REPLACE4611548 Ref: 1c5b4611548 Node: Process Management4611730 Ref: library/os os-process4611898 Ref: 1c5e4611898 Ref: library/os process-management4611898 Ref: 1c5f4611898 Ref: library/os os abort4612511 Ref: 1c614612511 Ref: library/os os add_dll_directory4612886 Ref: 1c24612886 Ref: library/os os execl4614034 Ref: 1c604614034 Ref: library/os os execle4614081 Ref: 1c624614081 Ref: library/os os execlp4614134 Ref: 1c634614134 Ref: library/os os execlpe4614182 Ref: 1c644614182 Ref: library/os os execv4614236 Ref: 1bc94614236 Ref: library/os os execve4614272 Ref: a404614272 Ref: library/os os execvp4614314 Ref: 1c654614314 Ref: library/os os execvpe4614351 Ref: 1c664614351 Ref: library/os os _exit4617570 Ref: 13b64617570 Ref: library/os os EX_OK4618318 Ref: 1c674618318 Ref: library/os os EX_USAGE4618422 Ref: 1c684618422 Ref: library/os os EX_DATAERR4618603 Ref: 1c694618603 Ref: library/os os EX_NOINPUT4618723 Ref: 1c6a4618723 Ref: library/os os EX_NOUSER4618867 Ref: 1c6b4618867 Ref: library/os os EX_NOHOST4618988 Ref: 1c6c4618988 Ref: library/os os EX_UNAVAILABLE4619109 Ref: 1c6d4619109 Ref: library/os os EX_SOFTWARE4619243 Ref: 1c6e4619243 Ref: library/os os EX_OSERR4619375 Ref: 1c6f4619375 Ref: library/os os EX_OSFILE4619556 Ref: 1c704619556 Ref: library/os os EX_CANTCREAT4619736 Ref: 1c714619736 Ref: library/os os EX_IOERR4619884 Ref: 1c724619884 Ref: library/os os EX_TEMPFAIL4620030 Ref: 1c734620030 Ref: library/os os EX_PROTOCOL4620303 Ref: 1c744620303 Ref: library/os os EX_NOPERM4620465 Ref: 1c754620465 Ref: library/os os EX_CONFIG4620670 Ref: 1c764620670 Ref: library/os os EX_NOTFOUND4620812 Ref: 1c774620812 Ref: library/os os fork4620948 Ref: 9614620948 Ref: library/os os forkpty4621619 Ref: 1c784621619 Ref: library/os os kill4622349 Ref: cf34622349 Ref: library/os os killpg4623244 Ref: 1c7b4623244 Ref: library/os os nice4623478 Ref: a484623478 Ref: library/os os plock4623639 Ref: 1c7c4623639 Ref: library/os os popen4623841 Ref: 2a94623841 Ref: library/os os posix_spawn4625121 Ref: 2574625121 Ref: library/os os POSIX_SPAWN_OPEN4626127 Ref: 1c7e4626127 Ref: library/os os POSIX_SPAWN_CLOSE4626300 Ref: 1c7f4626300 Ref: library/os os POSIX_SPAWN_DUP24626423 Ref: 1c804626423 Ref: library/os os posix_spawnp4629038 Ref: 1c7d4629038 Ref: library/os os register_at_fork4629753 Ref: 3b64629753 Ref: library/os os spawnl4631167 Ref: 1c1a4631167 Ref: library/os os spawnle4631209 Ref: 1c824631209 Ref: library/os os spawnlp4631257 Ref: 1c834631257 Ref: library/os os spawnlpe4631300 Ref: 1c844631300 Ref: library/os os spawnv4631349 Ref: 1c854631349 Ref: library/os os spawnve4631392 Ref: 1c864631392 Ref: library/os os spawnvp4631441 Ref: 1c874631441 Ref: library/os os spawnvpe4631485 Ref: 1c884631485 Ref: library/os os P_NOWAIT4635355 Ref: 1c894635355 Ref: library/os os P_NOWAITO4635377 Ref: 1c8b4635377 Ref: library/os os P_WAIT4635722 Ref: 1c8a4635722 Ref: library/os os P_DETACH4636138 Ref: 1c8c4636138 Ref: library/os os P_OVERLAY4636160 Ref: 1c8d4636160 Ref: library/os os startfile4636651 Ref: 1c8e4636651 Ref: library/os os system4638355 Ref: dc14638355 Ref: library/os os times4639911 Ref: a5c4639911 Ref: library/os os wait4640940 Ref: 66b4640940 Ref: library/os os waitid4641350 Ref: 66c4641350 Ref: library/os os P_PID4642167 Ref: 1c8f4642167 Ref: library/os os P_PGID4642186 Ref: 1c904642186 Ref: library/os os P_ALL4642206 Ref: 1c914642206 Ref: library/os os WEXITED4642405 Ref: 1c924642405 Ref: library/os os WSTOPPED4642426 Ref: 1c934642426 Ref: library/os os WNOWAIT4642448 Ref: 1c964642448 Ref: library/os os CLD_EXITED4642649 Ref: 1c974642649 Ref: library/os os CLD_DUMPED4642673 Ref: 1c984642673 Ref: library/os os CLD_TRAPPED4642697 Ref: 1c994642697 Ref: library/os os CLD_CONTINUED4642722 Ref: 1c9a4642722 Ref: library/os os waitpid4642920 Ref: 66d4642920 Ref: library/os os wait34644794 Ref: 6694644794 Ref: library/os os wait44645290 Ref: 66a4645290 Ref: library/os os WNOHANG4645752 Ref: 1c954645752 Ref: library/os os WCONTINUED4645989 Ref: 1c944645989 Ref: library/os os WUNTRACED4646221 Ref: 1c9b4646221 Ref: library/os os WCOREDUMP4646655 Ref: 1c9c4646655 Ref: library/os os WIFCONTINUED4646923 Ref: 1c9e4646923 Ref: library/os os WIFSTOPPED4647240 Ref: 1ca04647240 Ref: library/os os WIFSIGNALED4647631 Ref: 1c9d4647631 Ref: library/os os WIFEXITED4647810 Ref: 1ca14647810 Ref: library/os os WEXITSTATUS4648078 Ref: 1ca24648078 Ref: library/os os WSTOPSIG4648279 Ref: 1ca34648279 Ref: library/os os WTERMSIG4648498 Ref: 1ca44648498 Ref: Process Management-Footnote-14648777 Ref: Process Management-Footnote-24648849 Ref: Process Management-Footnote-34648958 Node: Interface to the scheduler4649007 Ref: library/os interface-to-the-scheduler4649186 Ref: 1ca54649186 Ref: library/os os SCHED_OTHER4649571 Ref: 1ca64649571 Ref: library/os os SCHED_BATCH4649634 Ref: 1ca74649634 Ref: library/os os SCHED_IDLE4649783 Ref: 1ca84649783 Ref: library/os os SCHED_SPORADIC4649877 Ref: 1ca94649877 Ref: library/os os SCHED_FIFO4649960 Ref: 1caa4649960 Ref: library/os os SCHED_RR4650031 Ref: 1cab4650031 Ref: library/os os SCHED_RESET_ON_FORK4650093 Ref: 1cac4650093 Ref: library/os os sched_param4650315 Ref: 1c814650315 Ref: library/os os sched_param sched_priority4650607 Ref: 1cad4650607 Ref: library/os os sched_get_priority_min4650703 Ref: a504650703 Ref: library/os os sched_get_priority_max4650868 Ref: a4f4650868 Ref: library/os os sched_setscheduler4651033 Ref: a574651033 Ref: library/os os sched_getscheduler4651319 Ref: a534651319 Ref: library/os os sched_setparam4651541 Ref: a564651541 Ref: library/os os sched_getparam4651753 Ref: a524651753 Ref: library/os os sched_rr_get_interval4651953 Ref: a544651953 Ref: library/os os sched_yield4652125 Ref: a584652125 Ref: library/os os sched_setaffinity4652196 Ref: a554652196 Ref: library/os os sched_getaffinity4652459 Ref: a514652459 Node: Miscellaneous System Information4652613 Ref: library/os miscellaneous-system-information4652791 Ref: 1cae4652791 Ref: library/os os-path4652791 Ref: 1caf4652791 Ref: library/os os confstr4652878 Ref: 1cb04652878 Ref: library/os os confstr_names4653913 Ref: 1cb14653913 Ref: library/os os cpu_count4654205 Ref: 87f4654205 Ref: library/os os getloadavg4654531 Ref: 1cb24654531 Ref: library/os os sysconf4654784 Ref: 1c0b4654784 Ref: library/os os sysconf_names4655204 Ref: 1cb34655204 Ref: library/os os curdir4655695 Ref: 18ad4655695 Ref: library/os os pardir4655896 Ref: 1c264655896 Ref: library/os os sep4656097 Ref: 19364656097 Ref: library/os os altsep4656509 Ref: 19374656509 Ref: library/os os extsep4656808 Ref: 1cb44656808 Ref: library/os os pathsep4656995 Ref: ff04656995 Ref: library/os os defpath4657239 Ref: 194c4657239 Ref: library/os os linesep4657448 Ref: 12a64657448 Ref: library/os os devnull4657861 Ref: 1cb54657861 Ref: library/os os RTLD_LAZY4658035 Ref: a5f4658035 Ref: library/os os RTLD_NOW4658058 Ref: a604658058 Ref: library/os os RTLD_GLOBAL4658080 Ref: a614658080 Ref: library/os os RTLD_LOCAL4658105 Ref: a624658105 Ref: library/os os RTLD_NODELETE4658129 Ref: a634658129 Ref: library/os os RTLD_NOLOAD4658156 Ref: a644658156 Ref: library/os os RTLD_DEEPBIND4658181 Ref: a654658181 Node: Random numbers<2>4658424 Ref: library/os random-numbers4658567 Ref: 1cb64658567 Ref: library/os os getrandom4658618 Ref: 5694658618 Ref: library/os os urandom4659452 Ref: 4d14659452 Ref: library/os os GRND_NONBLOCK4661376 Ref: 1cb84661376 Ref: library/os os GRND_RANDOM4661849 Ref: 1cb74661849 Ref: Random numbers<2>-Footnote-14662068 Ref: Random numbers<2>-Footnote-24662130 Node: io — Core tools for working with streams4662179 Ref: library/io doc4662393 Ref: 1cb94662393 Ref: library/io io-core-tools-for-working-with-streams4662393 Ref: 1cba4662393 Ref: library/io module-io4662393 Ref: a14662393 Ref: io — Core tools for working with streams-Footnote-14662739 Node: Overview4662800 Ref: library/io io-overview4662923 Ref: 12a14662923 Ref: library/io overview4662923 Ref: 1cbb4662923 Node: Text I/O4664180 Ref: library/io text-i-o4664252 Ref: 1cbc4664252 Node: Binary I/O4664943 Ref: library/io binary-i-o4665031 Ref: 1cbd4665031 Node: Raw I/O4665900 Ref: library/io raw-i-o4665971 Ref: 1cbe4665971 Node: High-level Module Interface4666424 Ref: library/io high-level-module-interface4666571 Ref: 1cbf4666571 Ref: library/io io DEFAULT_BUFFER_SIZE4666646 Ref: 12a34666646 Ref: library/io io open4666881 Ref: 65a4666881 Ref: library/io io open_code4667321 Ref: 1cc04667321 Ref: library/io io BlockingIOError4667990 Ref: 1cc24667990 Ref: library/io io UnsupportedOperation4668121 Ref: 1cc34668121 Node: Class hierarchy4668468 Ref: library/io class-hierarchy4668621 Ref: 1cc44668621 Node: I/O Base Classes4673284 Ref: library/io i-o-base-classes4673373 Ref: 1cc64673373 Ref: library/io io IOBase4673426 Ref: 1db4673426 Ref: library/io io IOBase close4675339 Ref: 1bdd4675339 Ref: library/io io IOBase closed4675749 Ref: 1cc74675749 Ref: library/io io IOBase fileno4675824 Ref: 1bdb4675824 Ref: library/io io IOBase flush4676045 Ref: 1cc84676045 Ref: library/io io IOBase isatty4676205 Ref: 12a44676205 Ref: library/io io IOBase readable4676345 Ref: 1cc94676345 Ref: library/io io IOBase readline4676507 Ref: 13ae4676507 Ref: library/io io IOBase readlines4676876 Ref: 14384676876 Ref: library/io io IOBase seek4677335 Ref: 1a624677335 Ref: library/io io IOBase seekable4678331 Ref: 1cca4678331 Ref: library/io io IOBase tell4678563 Ref: 1a634678563 Ref: library/io io IOBase truncate4678636 Ref: ca54678636 Ref: library/io io IOBase writable4679211 Ref: 1ccb4679211 Ref: library/io io IOBase writelines4679411 Ref: 14394679411 Ref: library/io io IOBase __del__4679631 Ref: 1ccc4679631 Ref: library/io io RawIOBase4679849 Ref: a134679849 Ref: library/io io RawIOBase read4680352 Ref: 7024680352 Ref: library/io io RawIOBase readall4681033 Ref: 1ccd4681033 Ref: library/io io RawIOBase readinto4681189 Ref: 7034681189 Ref: library/io io RawIOBase write4681527 Ref: 1cce4681527 Ref: library/io io BufferedIOBase4682163 Ref: 5884682163 Ref: library/io io BufferedIOBase raw4683380 Ref: 1cd04683380 Ref: library/io io BufferedIOBase detach4683650 Ref: 1cd14683650 Ref: library/io io BufferedIOBase read4684084 Ref: 1a224684084 Ref: library/io io BufferedIOBase read14684889 Ref: 1a214684889 Ref: library/io io BufferedIOBase readinto4685369 Ref: 1ccf4685369 Ref: library/io io BufferedIOBase readinto14685900 Ref: 7014685900 Ref: library/io io BufferedIOBase write4686392 Ref: 5894686392 Node: Raw File I/O4687209 Ref: library/io raw-file-i-o4687323 Ref: 1cd24687323 Ref: library/io io FileIO4687368 Ref: ca44687368 Ref: library/io io FileIO mode4689759 Ref: 1cd34689759 Ref: library/io io FileIO name4689834 Ref: 1ab84689834 Node: Buffered Streams4689979 Ref: library/io buffered-streams4690088 Ref: 1cd44690088 Ref: library/io io BytesIO4690232 Ref: 79b4690232 Ref: library/io io BytesIO getbuffer4690715 Ref: b6d4690715 Ref: library/io io BytesIO getvalue4691282 Ref: 1a1f4691282 Ref: library/io io BytesIO read14691404 Ref: 1cd54691404 Ref: library/io io BytesIO readinto14691583 Ref: 1cd64691583 Ref: library/io io BufferedReader4691734 Ref: b8a4691734 Ref: library/io io BufferedReader peek4692533 Ref: 1cd74692533 Ref: library/io io BufferedReader read4692804 Ref: 1cd84692804 Ref: library/io io BufferedReader read14693000 Ref: 1cd94693000 Ref: library/io io BufferedWriter4693334 Ref: 12a74693334 Ref: library/io io BufferedWriter flush4694407 Ref: 1cda4694407 Ref: library/io io BufferedWriter write4694591 Ref: 1cdb4694591 Ref: library/io io BufferedRandom4694878 Ref: 12a84694878 Ref: library/io io BufferedRWPair4695485 Ref: 1cc54695485 Node: Text I/O<2>4696425 Ref: library/io id14696513 Ref: 1cdc4696513 Ref: library/io io TextIOBase4696552 Ref: c394696552 Ref: library/io io TextIOBase encoding4696895 Ref: 1cdd4696895 Ref: library/io io TextIOBase errors4697055 Ref: 1cde4697055 Ref: library/io io TextIOBase newlines4697139 Ref: 1cdf4697139 Ref: library/io io TextIOBase buffer4697383 Ref: c3a4697383 Ref: library/io io TextIOBase detach4697656 Ref: 1ce04697656 Ref: library/io io TextIOBase read4698171 Ref: 1ce14698171 Ref: library/io io TextIOBase readline4698376 Ref: 18b94698376 Ref: library/io io TextIOBase seek4698639 Ref: 1ce24698639 Ref: library/io io TextIOBase tell4699607 Ref: 1ce34699607 Ref: library/io io TextIOBase write4699811 Ref: 1ce44699811 Ref: library/io io TextIOWrapper4699940 Ref: 5f34699940 Ref: library/io io TextIOWrapper line_buffering4703364 Ref: 1ce64703364 Ref: library/io io TextIOWrapper write_through4703446 Ref: 1ce74703446 Ref: library/io io TextIOWrapper reconfigure4703604 Ref: 39d4703604 Ref: library/io io StringIO4704379 Ref: 82d4704379 Ref: library/io io StringIO getvalue4705264 Ref: 1ce84705264 Ref: library/io io IncrementalNewlineDecoder4705912 Ref: 1ce94705912 Node: Performance<3>4706094 Ref: library/io performance4706211 Ref: 1cea4706211 Node: Binary I/O<2>4706460 Ref: library/io id24706544 Ref: 1ceb4706544 Node: Text I/O<3>4707196 Ref: library/io id34707307 Ref: 1cec4707307 Node: Multi-threading<3>4707884 Ref: library/io multi-threading4707992 Ref: 1ced4707992 Node: Reentrancy4708525 Ref: library/io reentrancy4708613 Ref: 1cee4708613 Node: time — Time access and conversions4709405 Ref: library/time doc4709642 Ref: 1cef4709642 Ref: library/time module-time4709642 Ref: 10a4709642 Ref: library/time time-time-access-and-conversions4709642 Ref: 1cf04709642 Ref: library/time epoch4710342 Ref: 1cf14710342 Ref: time — Time access and conversions-Footnote-14714715 Node: Functions<2>4714765 Ref: library/time functions4714877 Ref: 1cf24714877 Ref: library/time time-functions4714877 Ref: 1cf34714877 Ref: library/time time asctime4714916 Ref: b634714916 Ref: library/time time pthread_getcpuclockid4715584 Ref: 3fb4715584 Ref: library/time time clock_getres4716190 Ref: ab24716190 Ref: library/time time clock_gettime4716464 Ref: ab34716464 Ref: library/time time clock_gettime_ns4716731 Ref: 31e4716731 Ref: library/time time clock_settime4716930 Ref: ab44716930 Ref: library/time time clock_settime_ns4717188 Ref: 31f4717188 Ref: library/time time ctime4717390 Ref: 15624717390 Ref: library/time time get_clock_info4717957 Ref: ab14717957 Ref: library/time time gmtime4719088 Ref: b3f4719088 Ref: library/time time localtime4719567 Ref: 155c4719567 Ref: library/time time mktime4719856 Ref: b644719856 Ref: library/time time monotonic4720566 Ref: 76f4720566 Ref: library/time time monotonic_ns4721038 Ref: 3204721038 Ref: library/time time perf_counter4721180 Ref: 2aa4721180 Ref: library/time time perf_counter_ns4721621 Ref: 3214721621 Ref: library/time time process_time4721774 Ref: 2ab4721774 Ref: library/time time process_time_ns4722190 Ref: 3224722190 Ref: library/time time sleep4722343 Ref: 6804722343 Ref: library/time time strftime4723105 Ref: b654723105 Ref: library/time time strptime4730185 Ref: d914730185 Ref: library/time time struct_time4731886 Ref: 5994731886 Ref: library/time time time4734647 Ref: 31d4734647 Ref: library/time time thread_time4735946 Ref: 3f94735946 Ref: library/time time thread_time_ns4736495 Ref: 3fa4736495 Ref: library/time time time_ns4736646 Ref: 3234736646 Ref: library/time time tzset4736833 Ref: 1cf74736833 Ref: Functions<2>-Footnote-14740751 Ref: Functions<2>-Footnote-24740800 Ref: Functions<2>-Footnote-34740850 Ref: Functions<2>-Footnote-44740899 Ref: Functions<2>-Footnote-54741536 Ref: Functions<2>-Footnote-64741586 Node: Clock ID Constants4741634 Ref: library/time clock-id-constants4741773 Ref: 1cf84741773 Ref: library/time time-clock-id-constants4741773 Ref: 1cf54741773 Ref: library/time time CLOCK_BOOTTIME4741933 Ref: 3f54741933 Ref: library/time time CLOCK_HIGHRES4742415 Ref: 1cf94742415 Ref: library/time time CLOCK_MONOTONIC4742740 Ref: 3f64742740 Ref: library/time time CLOCK_MONOTONIC_RAW4742941 Ref: 1cfa4742941 Ref: library/time time CLOCK_PROCESS_CPUTIME_ID4743226 Ref: 1cfb4743226 Ref: library/time time CLOCK_PROF4743385 Ref: 3f74743385 Ref: library/time time CLOCK_THREAD_CPUTIME_ID4743561 Ref: 1cfc4743561 Ref: library/time time CLOCK_UPTIME4743703 Ref: 3f84743703 Ref: library/time time CLOCK_UPTIME_RAW4743989 Ref: 2394743989 Ref: library/time time CLOCK_REALTIME4744386 Ref: 1cf64744386 Node: Timezone Constants4744574 Ref: library/time time-timezone-constants4744692 Ref: 1cfd4744692 Ref: library/time timezone-constants4744692 Ref: 1cfe4744692 Ref: library/time time altzone4744749 Ref: 1cff4744749 Ref: library/time time daylight4745037 Ref: 1d004745037 Ref: library/time time timezone4745123 Ref: 1d014745123 Ref: library/time time tzname4745321 Ref: 1d024745321 Node: argparse — Parser for command-line options arguments and sub-commands4746506 Ref: library/argparse doc4746751 Ref: 1d034746751 Ref: library/argparse argparse-parser-for-command-line-options-arguments-and-sub-commands4746751 Ref: 1d044746751 Ref: library/argparse module-argparse4746751 Ref: 64746751 Ref: argparse — Parser for command-line options arguments and sub-commands-Footnote-14747851 Node: Example<7>4747918 Ref: library/argparse example4748067 Ref: 1d064748067 Node: Creating a parser4749684 Ref: library/argparse creating-a-parser4749773 Ref: 1d074749773 Node: Adding arguments4750136 Ref: library/argparse adding-arguments4750251 Ref: 1d084750251 Node: Parsing arguments4751398 Ref: library/argparse parsing-arguments4751487 Ref: 1d0b4751487 Node: ArgumentParser objects4752217 Ref: library/argparse argumentparser-objects4752398 Ref: 1d0d4752398 Ref: library/argparse argparse ArgumentParser4752463 Ref: 6954752463 Node: prog4754911 Ref: library/argparse prog4754988 Ref: 1d0e4754988 Node: usage4756850 Ref: library/argparse usage4756947 Ref: 1d0f4756947 Node: description4758117 Ref: library/argparse description4758216 Ref: 1d104758216 Node: epilog4758979 Ref: library/argparse epilog4759080 Ref: 1d114759080 Node: parents4759859 Ref: library/argparse parents4759964 Ref: 1d124759964 Node: formatter_class4761418 Ref: library/argparse formatter-class4761529 Ref: 1d134761529 Ref: library/argparse argparse RawDescriptionHelpFormatter4761747 Ref: 1d194761747 Ref: library/argparse argparse RawTextHelpFormatter4761795 Ref: 1d1a4761795 Ref: library/argparse argparse ArgumentDefaultsHelpFormatter4761836 Ref: 1d1b4761836 Ref: library/argparse argparse MetavarTypeHelpFormatter4761886 Ref: 1d1c4761886 Node: prefix_chars4765403 Ref: library/argparse prefix-chars4765528 Ref: 1d144765528 Node: fromfile_prefix_chars4766266 Ref: library/argparse fromfile-prefix-chars4766392 Ref: 1d154766392 Node: argument_default4767667 Ref: library/argparse argument-default4767793 Ref: 1d164767793 Node: allow_abbrev4768680 Ref: library/argparse allow-abbrev4768801 Ref: 6974768801 Ref: library/argparse id14768801 Ref: 1d214768801 Node: conflict_handler4769452 Ref: library/argparse conflict-handler4769565 Ref: 1d174769565 Node: add_help4771123 Ref: library/argparse add-help4771215 Ref: 1d184771215 Node: The add_argument method4772793 Ref: library/argparse the-add-argument-method4772985 Ref: 1d224772985 Ref: library/argparse argparse ArgumentParser add_argument4773058 Ref: 1d094773058 Node: name or flags4774848 Ref: library/argparse name-or-flags4774936 Ref: 1d234774936 Node: action4776085 Ref: library/argparse action4776187 Ref: 1d244776187 Node: nargs4781794 Ref: library/argparse nargs4781888 Ref: 1d254781888 Ref: library/argparse argparse-remainder4785676 Ref: 1d2d4785676 Node: const4786498 Ref: library/argparse const4786593 Ref: 1d264786593 Node: default4787788 Ref: library/argparse default4787882 Ref: 1d274787882 Node: type4789800 Ref: library/argparse type4789896 Ref: 1d1d4789896 Node: choices4792521 Ref: library/argparse choices4792618 Ref: 1d284792618 Node: required4794108 Ref: library/argparse required4794205 Ref: 1d294794205 Node: help4795165 Ref: library/argparse help4795262 Ref: 1d2a4795262 Node: metavar4797374 Ref: library/argparse metavar4797467 Ref: 1d2b4797467 Node: dest4799709 Ref: library/argparse dest4799812 Ref: 1d1e4799812 Node: Action classes4801447 Ref: library/argparse action-classes4801534 Ref: 1d2e4801534 Ref: library/argparse argparse Action4801816 Ref: 1d2c4801816 Node: The parse_args method4803604 Ref: library/argparse the-parse-args-method4803789 Ref: 1d2f4803789 Ref: library/argparse argparse ArgumentParser parse_args4803858 Ref: 1d0a4803858 Node: Option value syntax4804734 Ref: library/argparse option-value-syntax4804837 Ref: 1d324804837 Node: Invalid arguments4806234 Ref: library/argparse invalid-arguments4806368 Ref: 1d334806368 Node: Arguments containing -4807353 Ref: library/argparse arguments-containing4807506 Ref: 1d344807506 Node: Argument abbreviations prefix matching4809511 Ref: library/argparse argument-abbreviations-prefix-matching4809662 Ref: 1d354809662 Ref: library/argparse prefix-matching4809662 Ref: 6964809662 Node: Beyond sys argv4810590 Ref: library/argparse args4810739 Ref: 1d304810739 Ref: library/argparse beyond-sys-argv4810739 Ref: 1d364810739 Node: The Namespace object4811689 Ref: library/argparse namespace4811791 Ref: 1d314811791 Ref: library/argparse the-namespace-object4811791 Ref: 1d374811791 Ref: library/argparse argparse Namespace4811854 Ref: 1d0c4811854 Node: Other utilities4812878 Ref: library/argparse other-utilities4813063 Ref: 1d384813063 Node: Sub-commands4813335 Ref: library/argparse sub-commands4813424 Ref: 1d394813424 Ref: library/argparse argparse ArgumentParser add_subparsers4813471 Ref: 4a44813471 Node: FileType objects4822365 Ref: library/argparse filetype-objects4822478 Ref: 1d3a4822478 Ref: library/argparse argparse FileType4822533 Ref: 8204822533 Node: Argument groups4823983 Ref: library/argparse argument-groups4824100 Ref: 1d3b4824100 Ref: library/argparse argparse ArgumentParser add_argument_group4824153 Ref: 1d3c4824153 Node: Mutual exclusion4826258 Ref: library/argparse mutual-exclusion4826374 Ref: 1d3d4826374 Ref: library/argparse argparse ArgumentParser add_mutually_exclusive_group4826429 Ref: 1d3e4826429 Node: Parser defaults4828024 Ref: library/argparse parser-defaults4828138 Ref: 1d3f4828138 Ref: library/argparse argparse ArgumentParser set_defaults4828191 Ref: 1d204828191 Ref: library/argparse argparse ArgumentParser get_default4829315 Ref: 1d404829315 Node: Printing help4829672 Ref: library/argparse printing-help4829785 Ref: 1d414829785 Ref: library/argparse argparse ArgumentParser print_usage4830014 Ref: 1d424830014 Ref: library/argparse argparse ArgumentParser print_help4830246 Ref: 1d434830246 Ref: library/argparse argparse ArgumentParser format_usage4830600 Ref: 1d444830600 Ref: library/argparse argparse ArgumentParser format_help4830779 Ref: 1d454830779 Node: Partial parsing4830992 Ref: library/argparse partial-parsing4831114 Ref: 1d464831114 Ref: library/argparse argparse ArgumentParser parse_known_args4831167 Ref: 1d474831167 Node: Customizing file parsing4832206 Ref: library/argparse customizing-file-parsing4832330 Ref: 1d484832330 Ref: library/argparse argparse ArgumentParser convert_arg_line_to_args4832401 Ref: 1d1f4832401 Node: Exiting methods4833306 Ref: library/argparse exiting-methods4833433 Ref: 1d494833433 Ref: library/argparse argparse ArgumentParser exit4833486 Ref: 1d4a4833486 Ref: library/argparse argparse ArgumentParser error4834018 Ref: 1d4b4834018 Node: Intermixed parsing4834206 Ref: library/argparse intermixed-parsing4834300 Ref: 1d4c4834300 Ref: library/argparse argparse ArgumentParser parse_intermixed_args4834359 Ref: 3454834359 Ref: library/argparse argparse ArgumentParser parse_known_intermixed_args4834447 Ref: 1d4d4834447 Node: Upgrading optparse code4835980 Ref: library/argparse id24836135 Ref: 1d4e4836135 Ref: library/argparse upgrading-optparse-code4836135 Ref: b294836135 Node: getopt — C-style parser for command line options4838633 Ref: library/getopt doc4838881 Ref: 1d514838881 Ref: library/getopt getopt-c-style-parser-for-command-line-options4838881 Ref: 1d524838881 Ref: library/getopt module-getopt4838881 Ref: 874838881 Ref: library/getopt getopt getopt4839893 Ref: 1d534839893 Ref: library/getopt getopt gnu_getopt4842080 Ref: 1d554842080 Ref: library/getopt getopt GetoptError4842660 Ref: 1d544842660 Ref: library/getopt getopt error4843240 Ref: 1d564843240 Ref: getopt — C-style parser for command line options-Footnote-14845682 Node: logging — Logging facility for Python4845747 Ref: library/logging doc4845964 Ref: 1d574845964 Ref: library/logging logging-logging-facility-for-python4845964 Ref: 1d584845964 Ref: library/logging module-logging4845964 Ref: aa4845964 Ref: logging — Logging facility for Python-Footnote-14847733 Node: Logger Objects4847809 Ref: library/logging logger4847922 Ref: 1d594847922 Ref: library/logging logger-objects4847922 Ref: 1d5a4847922 Ref: library/logging logging Logger4849015 Ref: 3a74849015 Ref: library/logging logging Logger propagate4849042 Ref: 1d5c4849042 Ref: library/logging logging Logger setLevel4850331 Ref: 1d5d4850331 Ref: library/logging logging Logger isEnabledFor4852293 Ref: 1d604852293 Ref: library/logging logging Logger getEffectiveLevel4852636 Ref: 1d5f4852636 Ref: library/logging logging Logger getChild4853107 Ref: c8b4853107 Ref: library/logging logging Logger debug4853606 Ref: 7104853606 Ref: library/logging logging Logger info4858784 Ref: 1d634858784 Ref: library/logging logging Logger warning4858963 Ref: 1d654858963 Ref: library/logging logging Logger error4859369 Ref: 1d664859369 Ref: library/logging logging Logger critical4859550 Ref: 70f4859550 Ref: library/logging logging Logger log4859737 Ref: 70d4859737 Ref: library/logging logging Logger exception4859933 Ref: 70e4859933 Ref: library/logging logging Logger addFilter4860248 Ref: 1d674860248 Ref: library/logging logging Logger removeFilter4860347 Ref: 1d684860347 Ref: library/logging logging Logger filter4860454 Ref: 1d694860454 Ref: library/logging logging Logger addHandler4860891 Ref: 1d6a4860891 Ref: library/logging logging Logger removeHandler4860988 Ref: 1d6b4860988 Ref: library/logging logging Logger findCaller4861093 Ref: 1d6c4861093 Ref: library/logging logging Logger handle4861895 Ref: 1d6d4861895 Ref: library/logging logging Logger makeRecord4862294 Ref: 1d6e4862294 Ref: library/logging logging Logger hasHandlers4862556 Ref: 1d6f4862556 Node: Logging Levels4863175 Ref: library/logging levels4863312 Ref: 1d5e4863312 Ref: library/logging logging-levels4863312 Ref: 1d704863312 Node: Handler Objects4864182 Ref: library/logging handler4864322 Ref: 1d714864322 Ref: library/logging handler-objects4864322 Ref: 1d724864322 Ref: library/logging logging Handler4864648 Ref: 1d624864648 Ref: library/logging logging Handler __init__4864676 Ref: 1d734864676 Ref: library/logging logging Handler createLock4864971 Ref: 1d744864971 Ref: library/logging logging Handler acquire4865159 Ref: 1d754865159 Ref: library/logging logging Handler release4865273 Ref: 1d764865273 Ref: library/logging logging Handler setLevel4865375 Ref: 1d774865375 Ref: library/logging logging Handler setFormatter4865947 Ref: 1d784865947 Ref: library/logging logging Handler addFilter4866054 Ref: 1d794866054 Ref: library/logging logging Handler removeFilter4866154 Ref: 1d7a4866154 Ref: library/logging logging Handler filter4866262 Ref: 1d7b4866262 Ref: library/logging logging Handler flush4866661 Ref: 1d7c4866661 Ref: library/logging logging Handler close4866829 Ref: 1d7d4866829 Ref: library/logging logging Handler handle4867187 Ref: 1d7f4867187 Ref: library/logging logging Handler handleError4867465 Ref: 1d804867465 Ref: library/logging logging Handler format4868253 Ref: 1d824868253 Ref: library/logging logging Handler emit4868421 Ref: 1d814868421 Node: Formatter Objects4868735 Ref: library/logging formatter-objects4868875 Ref: 1d834868875 Ref: library/logging id14868875 Ref: 1d844868875 Ref: library/logging logging Formatter4870039 Ref: 1d614870039 Ref: library/logging logging Formatter format4871197 Ref: 1d884871197 Ref: library/logging logging Formatter formatTime4872611 Ref: 1d864872611 Ref: library/logging logging Formatter formatException4874908 Ref: 1d894874908 Ref: library/logging logging Formatter formatStack4875247 Ref: 1d8a4875247 Node: Filter Objects4875539 Ref: library/logging filter4875681 Ref: 1d8c4875681 Ref: library/logging filter-objects4875681 Ref: 1d8d4875681 Ref: library/logging logging Filter4876195 Ref: b774876195 Ref: library/logging logging Filter filter4876485 Ref: 1d8e4876485 Node: LogRecord Objects4878466 Ref: library/logging log-record4878611 Ref: 1d914878611 Ref: library/logging logrecord-objects4878611 Ref: 1d924878611 Ref: library/logging logging LogRecord4878904 Ref: 9064878904 Ref: library/logging logging LogRecord getMessage4880731 Ref: 1d944880731 Node: LogRecord attributes4882229 Ref: library/logging id24882381 Ref: 1d974882381 Ref: library/logging logrecord-attributes4882381 Ref: 1d854882381 Node: LoggerAdapter Objects4890331 Ref: library/logging logger-adapter4890479 Ref: 1d994890479 Ref: library/logging loggeradapter-objects4890479 Ref: 1d9a4890479 Ref: library/logging logging LoggerAdapter4890759 Ref: c8c4890759 Ref: library/logging logging LoggerAdapter process4890952 Ref: 1d9c4890952 Node: Thread Safety4892164 Ref: library/logging thread-safety4892314 Ref: 1d9d4892314 Node: Module-Level Functions4892973 Ref: library/logging module-level-functions4893125 Ref: 1d9e4893125 Ref: library/logging logging getLogger4893283 Ref: 1d5b4893283 Ref: library/logging logging getLoggerClass4893871 Ref: 1d9f4893871 Ref: library/logging logging getLogRecordFactory4894349 Ref: 1d954894349 Ref: library/logging logging debug4894808 Ref: 1d644894808 Ref: library/logging logging info4898655 Ref: 1d8f4898655 Ref: library/logging logging warning4898833 Ref: 1da14898833 Ref: library/logging logging error4899225 Ref: 1da24899225 Ref: library/logging logging critical4899405 Ref: 1da34899405 Ref: library/logging logging exception4899591 Ref: 1da44899591 Ref: library/logging logging log4899898 Ref: 1da54899898 Ref: library/logging logging disable4900826 Ref: 1da64900826 Ref: library/logging logging addLevelName4902042 Ref: 1da74902042 Ref: library/logging logging getLevelName4902700 Ref: 1da94902700 Ref: library/logging logging makeLogRecord4904307 Ref: 1d934904307 Ref: library/logging logging basicConfig4904672 Ref: 1e04904672 Ref: library/logging logging shutdown4908998 Ref: 1d7e4908998 Ref: library/logging logging setLoggerClass4909440 Ref: 1da04909440 Ref: library/logging logging setLogRecordFactory4910074 Ref: 1d964910074 Ref: Module-Level Functions-Footnote-14911407 Node: Module-Level Attributes4911450 Ref: library/logging module-level-attributes4911625 Ref: 1daa4911625 Ref: library/logging logging lastResort4911694 Ref: b764911694 Node: Integration with the warnings module4912303 Ref: library/logging integration-with-the-warnings-module4912447 Ref: 1dab4912447 Ref: library/logging logging captureWarnings4912669 Ref: 1dac4912669 Ref: Integration with the warnings module-Footnote-14914054 Ref: Integration with the warnings module-Footnote-24914103 Node: logging config — Logging configuration4914156 Ref: library/logging config doc4914360 Ref: 1dae4914360 Ref: library/logging config logging-config-logging-configuration4914360 Ref: 1daf4914360 Ref: library/logging config module-logging config4914360 Ref: ab4914360 Ref: logging config — Logging configuration-Footnote-14914980 Node: Configuration functions4915053 Ref: library/logging config configuration-functions4915193 Ref: 1db04915193 Ref: library/logging config logging-config-api4915193 Ref: c884915193 Ref: library/logging config logging config dictConfig4915635 Ref: b2b4915635 Ref: library/logging config logging config fileConfig4917753 Ref: 3a94917753 Ref: library/logging config logging config listen4919984 Ref: 8724919984 Ref: library/logging config logging config stopListening4923322 Ref: 1db44923322 Node: Configuration dictionary schema4923566 Ref: library/logging config configuration-dictionary-schema4923740 Ref: 1db54923740 Ref: library/logging config logging-config-dictschema4923740 Ref: 1db14923740 Node: Dictionary Schema Details4924678 Ref: library/logging config dictionary-schema-details4924805 Ref: 1db74924805 Node: Incremental Configuration4929782 Ref: library/logging config incremental-configuration4929936 Ref: 1dbb4929936 Ref: library/logging config logging-config-dict-incremental4929936 Ref: 1dba4929936 Node: Object connections4931381 Ref: library/logging config logging-config-dict-connections4931530 Ref: 1db64931530 Ref: library/logging config object-connections4931530 Ref: 1dbc4931530 Node: User-defined objects4933925 Ref: library/logging config logging-config-dict-userdef4934075 Ref: 1db84934075 Ref: library/logging config user-defined-objects4934075 Ref: 1dbd4934075 Node: Access to external objects4937341 Ref: library/logging config access-to-external-objects4937499 Ref: 1dbe4937499 Ref: library/logging config logging-config-dict-externalobj4937499 Ref: 1dbf4937499 Node: Access to internal objects4938798 Ref: library/logging config access-to-internal-objects4938974 Ref: 1dc04938974 Ref: library/logging config logging-config-dict-internalobj4938974 Ref: 1dc14938974 Node: Import resolution and custom importers4942328 Ref: library/logging config import-resolution-and-custom-importers4942469 Ref: 1dc34942469 Ref: library/logging config logging-import-resolution4942469 Ref: 1dc44942469 Node: Configuration file format4943447 Ref: library/logging config configuration-file-format4943589 Ref: 1dc54943589 Ref: library/logging config logging-config-fileformat4943589 Ref: 1db24943589 Node: logging handlers — Logging handlers4951284 Ref: library/logging handlers doc4951484 Ref: 1dc64951484 Ref: library/logging handlers logging-handlers-logging-handlers4951484 Ref: 1dc74951484 Ref: library/logging handlers module-logging handlers4951484 Ref: ac4951484 Ref: logging handlers — Logging handlers-Footnote-14952548 Node: StreamHandler4952624 Ref: library/logging handlers stream-handler4952731 Ref: 1dc94952731 Ref: library/logging handlers streamhandler4952731 Ref: 1dca4952731 Ref: library/logging handlers logging StreamHandler4953044 Ref: b754953044 Ref: library/logging handlers logging StreamHandler emit4953281 Ref: 1dcb4953281 Ref: library/logging handlers logging StreamHandler flush4953614 Ref: 1dcc4953614 Ref: library/logging handlers logging StreamHandler setStream4953907 Ref: 3a84953907 Node: FileHandler4954706 Ref: library/logging handlers file-handler4954833 Ref: 1dcd4954833 Ref: library/logging handlers filehandler4954833 Ref: 1dce4954833 Ref: library/logging handlers logging FileHandler4955067 Ref: 1dc84955067 Ref: library/logging handlers logging FileHandler close4955717 Ref: 1dd04955717 Ref: library/logging handlers logging FileHandler emit4955772 Ref: 1dcf4955772 Node: NullHandler4955847 Ref: library/logging handlers null-handler4955979 Ref: 1dd14955979 Ref: library/logging handlers nullhandler4955979 Ref: 1dd24955979 Ref: library/logging handlers logging NullHandler4956237 Ref: c1c4956237 Ref: library/logging handlers logging NullHandler emit4956336 Ref: 1dd34956336 Ref: library/logging handlers logging NullHandler handle4956405 Ref: 1dd44956405 Ref: library/logging handlers logging NullHandler createLock4956476 Ref: 1dd54956476 Node: WatchedFileHandler4956758 Ref: library/logging handlers watched-file-handler4956898 Ref: 1dd74956898 Ref: library/logging handlers watchedfilehandler4956898 Ref: 1dd84956898 Ref: library/logging handlers logging handlers WatchedFileHandler4957913 Ref: 1dd94957913 Ref: library/logging handlers logging handlers WatchedFileHandler reopenIfNeeded4958586 Ref: 5624958586 Ref: library/logging handlers logging handlers WatchedFileHandler emit4958877 Ref: 1dda4958877 Node: BaseRotatingHandler4959045 Ref: library/logging handlers base-rotating-handler4959193 Ref: 1ddb4959193 Ref: library/logging handlers baserotatinghandler4959193 Ref: 1ddc4959193 Ref: library/logging handlers logging handlers BaseRotatingHandler4959580 Ref: 1ddd4959580 Ref: library/logging handlers logging handlers BaseRotatingHandler namer4959756 Ref: 1dde4959756 Ref: library/logging handlers logging handlers BaseRotatingHandler rotator4960383 Ref: 1de04960383 Ref: library/logging handlers logging handlers BaseRotatingHandler rotation_filename4960666 Ref: 1ddf4960666 Ref: library/logging handlers logging handlers BaseRotatingHandler rotate4961235 Ref: 1de14961235 Node: RotatingFileHandler4962545 Ref: library/logging handlers rotating-file-handler4962699 Ref: 1de34962699 Ref: library/logging handlers rotatingfilehandler4962699 Ref: 1de44962699 Ref: library/logging handlers logging handlers RotatingFileHandler4962891 Ref: 1db94962891 Ref: library/logging handlers logging handlers RotatingFileHandler doRollover4964693 Ref: 1de64964693 Ref: library/logging handlers logging handlers RotatingFileHandler emit4964773 Ref: 1de54964773 Node: TimedRotatingFileHandler4964905 Ref: library/logging handlers timed-rotating-file-handler4965053 Ref: 1de74965053 Ref: library/logging handlers timedrotatingfilehandler4965053 Ref: 1de84965053 Ref: library/logging handlers logging handlers TimedRotatingFileHandler4965286 Ref: 86e4965286 Ref: library/logging handlers logging handlers TimedRotatingFileHandler doRollover4970266 Ref: 1dea4970266 Ref: library/logging handlers logging handlers TimedRotatingFileHandler emit4970346 Ref: 1de94970346 Node: SocketHandler4970473 Ref: library/logging handlers socket-handler4970617 Ref: 1deb4970617 Ref: library/logging handlers sockethandler4970617 Ref: 1dec4970617 Ref: library/logging handlers logging handlers SocketHandler4970829 Ref: 86f4970829 Ref: library/logging handlers logging handlers SocketHandler close4971236 Ref: 1ded4971236 Ref: library/logging handlers logging handlers SocketHandler emit4971293 Ref: 1dee4971293 Ref: library/logging handlers logging handlers SocketHandler handleError4971728 Ref: 1def4971728 Ref: library/logging handlers logging handlers SocketHandler makeSocket4971958 Ref: 1df04971958 Ref: library/logging handlers logging handlers SocketHandler makePickle4972201 Ref: 1df14972201 Ref: library/logging handlers logging handlers SocketHandler send4973011 Ref: 1df24973011 Ref: library/logging handlers logging handlers SocketHandler createSocket4973332 Ref: 1df34973332 Node: DatagramHandler4974532 Ref: library/logging handlers datagram-handler4974665 Ref: 1df44974665 Ref: library/logging handlers datagramhandler4974665 Ref: 1df54974665 Ref: library/logging handlers logging handlers DatagramHandler4974901 Ref: 8704974901 Ref: library/logging handlers logging handlers DatagramHandler emit4975312 Ref: 1df64975312 Ref: library/logging handlers logging handlers DatagramHandler makeSocket4975666 Ref: 1df74975666 Ref: library/logging handlers logging handlers DatagramHandler send4975852 Ref: 1df84975852 Node: SysLogHandler4976067 Ref: library/logging handlers syslog-handler4976204 Ref: 1df94976204 Ref: library/logging handlers sysloghandler4976204 Ref: 1dfa4976204 Ref: library/logging handlers logging handlers SysLogHandler4976410 Ref: a1e4976410 Ref: library/logging handlers logging handlers SysLogHandler close4978073 Ref: 1dfb4978073 Ref: library/logging handlers logging handlers SysLogHandler emit4978149 Ref: 1dfc4978149 Ref: library/logging handlers logging handlers SysLogHandler encodePriority4980031 Ref: 1dfd4980031 Ref: library/logging handlers logging handlers SysLogHandler mapPriority4984055 Ref: 1dfe4984055 Ref: SysLogHandler-Footnote-14984545 Ref: SysLogHandler-Footnote-24984588 Ref: SysLogHandler-Footnote-34984637 Node: NTEventLogHandler4984680 Ref: library/logging handlers nt-eventlog-handler4984813 Ref: 1dff4984813 Ref: library/logging handlers nteventloghandler4984813 Ref: 1e004984813 Ref: library/logging handlers logging handlers NTEventLogHandler4985148 Ref: 1e014985148 Ref: library/logging handlers logging handlers NTEventLogHandler close4986209 Ref: 1e024986209 Ref: library/logging handlers logging handlers NTEventLogHandler emit4986611 Ref: 1e034986611 Ref: library/logging handlers logging handlers NTEventLogHandler getEventCategory4986769 Ref: 1e044986769 Ref: library/logging handlers logging handlers NTEventLogHandler getEventType4986971 Ref: 1e054986971 Ref: library/logging handlers logging handlers NTEventLogHandler getMessageID4987564 Ref: 1e064987564 Node: SMTPHandler4987994 Ref: library/logging handlers smtp-handler4988127 Ref: 1e074988127 Ref: library/logging handlers smtphandler4988127 Ref: 1e084988127 Ref: library/logging handlers logging handlers SMTPHandler4988324 Ref: 1e094988324 Ref: library/logging handlers logging handlers SMTPHandler emit4989577 Ref: 1e0a4989577 Ref: library/logging handlers logging handlers SMTPHandler getSubject4989681 Ref: 1e0b4989681 Node: MemoryHandler4989827 Ref: library/logging handlers memory-handler4989954 Ref: 1e0c4989954 Ref: library/logging handlers memoryhandler4989954 Ref: 1e0d4989954 Ref: library/logging handlers logging handlers BufferingHandler4990657 Ref: 1e0e4990657 Ref: library/logging handlers logging handlers BufferingHandler emit4990853 Ref: 1e0f4990853 Ref: library/logging handlers logging handlers BufferingHandler flush4991043 Ref: 1e114991043 Ref: library/logging handlers logging handlers BufferingHandler shouldFlush4991196 Ref: 1e104991196 Ref: library/logging handlers logging handlers MemoryHandler4991379 Ref: 1dc24991379 Ref: library/logging handlers logging handlers MemoryHandler close4992194 Ref: 1e134992194 Ref: library/logging handlers logging handlers MemoryHandler flush4992322 Ref: 1e144992322 Ref: library/logging handlers logging handlers MemoryHandler setTarget4992593 Ref: 1e124992593 Ref: library/logging handlers logging handlers MemoryHandler shouldFlush4992683 Ref: 1e154992683 Node: HTTPHandler4992809 Ref: library/logging handlers http-handler4992937 Ref: 1e164992937 Ref: library/logging handlers httphandler4992937 Ref: 1e174992937 Ref: library/logging handlers logging handlers HTTPHandler4993168 Ref: 7114993168 Ref: library/logging handlers logging handlers HTTPHandler mapLogRecord4994128 Ref: 1e184994128 Ref: library/logging handlers logging handlers HTTPHandler emit4994584 Ref: 1e194994584 Node: QueueHandler4995318 Ref: library/logging handlers queue-handler4995446 Ref: 1e1a4995446 Ref: library/logging handlers queuehandler4995446 Ref: 1e1b4995446 Ref: library/logging handlers logging handlers QueueHandler4996185 Ref: 1e1c4996185 Ref: library/logging handlers logging handlers QueueHandler emit4996682 Ref: 1e1e4996682 Ref: library/logging handlers logging handlers QueueHandler prepare4997161 Ref: 1e1f4997161 Ref: library/logging handlers logging handlers QueueHandler enqueue4997708 Ref: 1e1d4997708 Node: QueueListener4997954 Ref: library/logging handlers queue-listener4998062 Ref: 1e204998062 Ref: library/logging handlers queuelistener4998062 Ref: 1e214998062 Ref: library/logging handlers logging handlers QueueListener4999082 Ref: 7124999082 Ref: library/logging handlers logging handlers QueueListener dequeue5000134 Ref: 1e225000134 Ref: library/logging handlers logging handlers QueueListener prepare5000415 Ref: 1e235000415 Ref: library/logging handlers logging handlers QueueListener handle5000732 Ref: 1e245000732 Ref: library/logging handlers logging handlers QueueListener start5000994 Ref: 1e255000994 Ref: library/logging handlers logging handlers QueueListener stop5001157 Ref: 1e265001157 Ref: library/logging handlers logging handlers QueueListener enqueue_sentinel5001468 Ref: 1e275001468 Node: getpass — Portable password input5001965 Ref: library/getpass doc5002181 Ref: 1e285002181 Ref: library/getpass getpass-portable-password-input5002181 Ref: 1e295002181 Ref: library/getpass module-getpass5002181 Ref: 885002181 Ref: library/getpass getpass getpass5002431 Ref: 1e2a5002431 Ref: library/getpass getpass GetPassWarning5003280 Ref: 1e2b5003280 Ref: library/getpass getpass getuser5003408 Ref: 1bc05003408 Ref: getpass — Portable password input-Footnote-15003995 Node: curses — Terminal handling for character-cell displays5004061 Ref: library/curses doc5004296 Ref: 1e2c5004296 Ref: library/curses curses-terminal-handling-for-character-cell-displays5004296 Ref: 1e2d5004296 Ref: library/curses module-curses5004296 Ref: 2c5004296 Ref: curses — Terminal handling for character-cell displays-Footnote-15006520 Node: Functions<3>5006583 Ref: library/curses curses-functions5006711 Ref: 1e2f5006711 Ref: library/curses functions5006711 Ref: 1e305006711 Ref: library/curses curses error5006815 Ref: 1e315006815 Ref: library/curses curses baudrate5007177 Ref: 1e325007177 Ref: library/curses curses beep5007529 Ref: 1e335007529 Ref: library/curses curses can_change_color5007595 Ref: 1e345007595 Ref: library/curses curses cbreak5007767 Ref: 1e355007767 Ref: library/curses curses color_content5008245 Ref: 1e375008245 Ref: library/curses curses color_pair5008628 Ref: 1e385008628 Ref: library/curses curses curs_set5009003 Ref: 1e3a5009003 Ref: library/curses curses def_prog_mode5009431 Ref: 1e3b5009431 Ref: library/curses curses def_shell_mode5009759 Ref: 1e3d5009759 Ref: library/curses curses delay_output5010105 Ref: 1e3f5010105 Ref: library/curses curses doupdate5010195 Ref: 1e405010195 Ref: library/curses curses echo5011020 Ref: 1e445011020 Ref: library/curses curses endwin5011156 Ref: 1e455011156 Ref: library/curses curses erasechar5011259 Ref: 1e465011259 Ref: library/curses curses filter5011527 Ref: 1e475011527 Ref: library/curses curses flash5012138 Ref: 1e495012138 Ref: library/curses curses flushinp5012401 Ref: 1e4a5012401 Ref: library/curses curses getmouse5012587 Ref: 1e4b5012587 Ref: library/curses curses getsyx5013393 Ref: 1e4d5013393 Ref: library/curses curses getwin5013604 Ref: 1e4f5013604 Ref: library/curses curses has_colors5013840 Ref: 1e505013840 Ref: library/curses curses has_ic5013972 Ref: 1e515013972 Ref: library/curses curses has_il5014228 Ref: 1e525014228 Ref: library/curses curses has_key5014525 Ref: 1e535014525 Ref: library/curses curses halfdelay5014679 Ref: 1e545014679 Ref: library/curses curses init_color5015117 Ref: 1e565015117 Ref: library/curses curses init_pair5015774 Ref: 1e575015774 Ref: library/curses curses initscr5016495 Ref: 1e485016495 Ref: library/curses curses is_term_resized5016770 Ref: 1e5a5016770 Ref: library/curses curses isendwin5016941 Ref: 1e5c5016941 Ref: library/curses curses keyname5017099 Ref: 1e5d5017099 Ref: library/curses curses killchar5017630 Ref: 1e5e5017630 Ref: library/curses curses longname5017901 Ref: 1e5f5017901 Ref: library/curses curses meta5018176 Ref: 1e605018176 Ref: library/curses curses mouseinterval5018333 Ref: 1e615018333 Ref: library/curses curses mousemask5018632 Ref: 1e625018632 Ref: library/curses curses napms5019052 Ref: 1e635019052 Ref: library/curses curses newpad5019120 Ref: 1e645019120 Ref: library/curses curses newwin5020208 Ref: 1e655020208 Ref: library/curses curses nl5020575 Ref: 1e665020575 Ref: library/curses curses nocbreak5020790 Ref: 1e555020790 Ref: library/curses curses noecho5020911 Ref: 1e675020911 Ref: library/curses curses nonl5021010 Ref: 1e685021010 Ref: library/curses curses noqiflush5021503 Ref: 1e695021503 Ref: library/curses curses noraw5021893 Ref: 1e6a5021893 Ref: library/curses curses pair_content5022008 Ref: 1e6b5022008 Ref: library/curses curses pair_number5022234 Ref: 1e395022234 Ref: library/curses curses putp5022426 Ref: 1e6c5022426 Ref: library/curses curses qiflush5022672 Ref: 1e6d5022672 Ref: library/curses curses raw5022938 Ref: 1e365022938 Ref: library/curses curses reset_prog_mode5023180 Ref: 1e3c5023180 Ref: library/curses curses reset_shell_mode5023328 Ref: 1e3e5023328 Ref: library/curses curses resetty5023476 Ref: 1e6e5023476 Ref: library/curses curses resize_term5023618 Ref: 1e5b5023618 Ref: library/curses curses resizeterm5024157 Ref: 1e705024157 Ref: library/curses curses savetty5024430 Ref: 1e6f5024430 Ref: library/curses curses setsyx5024565 Ref: 1e715024565 Ref: library/curses curses setupterm5024735 Ref: 1e725024735 Ref: library/curses curses start_color5025152 Ref: 1e735025152 Ref: library/curses curses termattrs5025832 Ref: 1e745025832 Ref: library/curses curses termname5026062 Ref: 1e755026062 Ref: library/curses curses tigetflag5026211 Ref: 1e765026211 Ref: library/curses curses tigetnum5026527 Ref: 1e775026527 Ref: library/curses curses tigetstr5026843 Ref: 1e785026843 Ref: library/curses curses tparm5027153 Ref: 1e795027153 Ref: library/curses curses typeahead5027490 Ref: 1e7a5027490 Ref: library/curses curses unctrl5028083 Ref: 1e7b5028083 Ref: library/curses curses ungetch5028364 Ref: 1e7c5028364 Ref: library/curses curses update_lines_cols5028541 Ref: 6c65028541 Ref: library/curses curses unget_wch5028700 Ref: 9e05028700 Ref: library/curses curses ungetmouse5028918 Ref: 1e7d5028918 Ref: library/curses curses use_env5029077 Ref: 1e7e5029077 Ref: library/curses curses use_default_colors5029587 Ref: 1e585029587 Ref: library/curses curses wrapper5030020 Ref: 2a15030020 Node: Window Objects5030831 Ref: library/curses curses-window-objects5030980 Ref: 1e595030980 Ref: library/curses window-objects5030980 Ref: 1e7f5030980 Ref: library/curses curses window addch5031162 Ref: 1e805031162 Ref: library/curses curses window addnstr5031765 Ref: 1e815031765 Ref: library/curses curses window addstr5032024 Ref: 1e425032024 Ref: library/curses curses window attroff5033024 Ref: 1e825033024 Ref: library/curses curses window attron5033169 Ref: 1e835033169 Ref: library/curses curses window attrset5033310 Ref: 1e845033310 Ref: library/curses curses window bkgd5033458 Ref: 1e855033458 Ref: library/curses curses window bkgdset5033903 Ref: 1e865033903 Ref: library/curses curses window border5034469 Ref: 1e875034469 Ref: library/curses curses window box5036421 Ref: 1e885036421 Ref: library/curses curses window chgat5036649 Ref: 1e895036649 Ref: library/curses curses window clear5037273 Ref: 1e8b5037273 Ref: library/curses curses window clearok5037428 Ref: 1e8d5037428 Ref: library/curses curses window clrtobot5037573 Ref: 1e8e5037573 Ref: library/curses curses window clrtoeol5037770 Ref: 1e8f5037770 Ref: library/curses curses window cursyncup5037850 Ref: 1e905037850 Ref: library/curses curses window delch5038018 Ref: 1e915038018 Ref: library/curses curses window deleteln5038097 Ref: 1e925038097 Ref: library/curses curses window derwin5038221 Ref: 1e935038221 Ref: library/curses curses window echochar5038631 Ref: 1e955038631 Ref: library/curses curses window enclose5038785 Ref: 1e965038785 Ref: library/curses curses window encoding5039089 Ref: 9de5039089 Ref: library/curses curses window erase5039473 Ref: 1e8c5039473 Ref: library/curses curses window getbegyx5039526 Ref: 1e975039526 Ref: library/curses curses window getbkgd5039630 Ref: 1e985039630 Ref: library/curses curses window getch5039745 Ref: 1e4c5039745 Ref: library/curses curses window get_wch5040065 Ref: 9df5040065 Ref: library/curses curses window getkey5040331 Ref: 1e995040331 Ref: library/curses curses window getmaxyx5040639 Ref: 1e9a5040639 Ref: library/curses curses window getparyx5040744 Ref: 1e9b5040744 Ref: library/curses curses window getstr5040948 Ref: 1e9c5040948 Ref: library/curses curses window getyx5041164 Ref: 1e9d5041164 Ref: library/curses curses window hline5041305 Ref: 1e9e5041305 Ref: library/curses curses window idcok5041491 Ref: 1e9f5041491 Ref: library/curses curses window idlok5041837 Ref: 1ea05041837 Ref: library/curses curses window immedok5042030 Ref: 1ea15042030 Ref: library/curses curses window inch5042379 Ref: 1ea25042379 Ref: library/curses curses window insch5042567 Ref: 1ea35042567 Ref: library/curses curses window insdelln5042781 Ref: 1ea45042781 Ref: library/curses curses window insertln5043160 Ref: 1ea55043160 Ref: library/curses curses window insnstr5043290 Ref: 1ea65043290 Ref: library/curses curses window insstr5043803 Ref: 1ea75043803 Ref: library/curses curses window instr5044222 Ref: 1ea85044222 Ref: library/curses curses window is_linetouched5044618 Ref: 1ea95044618 Ref: library/curses curses window is_wintouched5044901 Ref: 1eaa5044901 Ref: library/curses curses window keypad5045081 Ref: 1eab5045081 Ref: library/curses curses window leaveok5045349 Ref: 1e4e5045349 Ref: library/curses curses window move5045700 Ref: 1eac5045700 Ref: library/curses curses window mvderwin5045783 Ref: 1ead5045783 Ref: library/curses curses window mvwin5046060 Ref: 1eae5046060 Ref: library/curses curses window nodelay5046176 Ref: 1eaf5046176 Ref: library/curses curses window notimeout5046285 Ref: 1eb05046285 Ref: library/curses curses window noutrefresh5046549 Ref: 1e415046549 Ref: library/curses curses window overlay5046823 Ref: 1eb15046823 Ref: library/curses curses window overwrite5047472 Ref: 1eb25047472 Ref: library/curses curses window putwin5048124 Ref: 1eb35048124 Ref: library/curses curses window redrawln5048330 Ref: 1eb45048330 Ref: library/curses curses window redrawwin5048536 Ref: 1eb55048536 Ref: library/curses curses window refresh5048682 Ref: 1e435048682 Ref: library/curses curses window resize5049703 Ref: 1eb65049703 Ref: library/curses curses window scroll5050055 Ref: 1eb75050055 Ref: library/curses curses window scrollok5050163 Ref: 1eb85050163 Ref: library/curses curses window setscrreg5050699 Ref: 1eb95050699 Ref: library/curses curses window standend5050868 Ref: 1eba5050868 Ref: library/curses curses window standout5051019 Ref: 1ebb5051019 Ref: library/curses curses window subpad5051089 Ref: 1ebc5051089 Ref: library/curses curses window subwin5051328 Ref: 1e945051328 Ref: library/curses curses window syncdown5051686 Ref: 1ebd5051686 Ref: library/curses curses window syncok5051932 Ref: 1ebe5051932 Ref: library/curses curses window syncup5052095 Ref: 1ebf5052095 Ref: library/curses curses window timeout5052221 Ref: 1ec05052221 Ref: library/curses curses window touchline5052724 Ref: 1e8a5052724 Ref: library/curses curses window touchwin5053032 Ref: 1ec15053032 Ref: library/curses curses window untouchwin5053157 Ref: 1ec25053157 Ref: library/curses curses window vline5053290 Ref: 1ec35053290 Ref: Window Objects-Footnote-15053510 Node: Constants<6>5053553 Ref: library/curses constants5053681 Ref: 1ec45053681 Ref: library/curses curses ERR5053788 Ref: 1ec55053788 Ref: library/curses curses OK5053933 Ref: 1ec65053933 Ref: library/curses curses version5054076 Ref: 1ec75054076 Ref: library/curses curses ncurses_version5054213 Ref: 1bf5054213 Node: curses textpad — Text input widget for curses programs5072772 Ref: library/curses curses-textpad-text-input-widget-for-curses-programs5073019 Ref: 1ec85073019 Ref: library/curses module-curses textpad5073019 Ref: 2f5073019 Ref: library/curses curses textpad rectangle5073609 Ref: 1eca5073609 Node: Textbox objects5074332 Ref: library/curses curses-textpad-objects5074440 Ref: 1ecb5074440 Ref: library/curses textbox-objects5074440 Ref: 1ecc5074440 Ref: library/curses curses textpad Textbox5074556 Ref: 1ec95074556 Ref: library/curses curses textpad Textbox edit5075035 Ref: 1ece5075035 Ref: library/curses curses textpad Textbox do_command5075606 Ref: 1ecf5075606 Ref: library/curses curses textpad Textbox gather5079130 Ref: 1ed05079130 Ref: library/curses curses textpad Textbox stripspaces5079323 Ref: 1ecd5079323 Node: curses ascii — Utilities for ASCII characters5079734 Ref: library/curses ascii doc5079976 Ref: 1ed15079976 Ref: library/curses ascii curses-ascii-utilities-for-ascii-characters5079976 Ref: 1ed25079976 Ref: library/curses ascii module-curses ascii5079976 Ref: 2d5079976 Ref: library/curses ascii curses ascii isalnum5083658 Ref: 1ed35083658 Ref: library/curses ascii curses ascii isalpha5083805 Ref: 1ed45083805 Ref: library/curses ascii curses ascii isascii5083950 Ref: 1ed55083950 Ref: library/curses ascii curses ascii isblank5084059 Ref: 1ed65084059 Ref: library/curses ascii curses ascii iscntrl5084172 Ref: 1ed75084172 Ref: library/curses ascii curses ascii isdigit5084298 Ref: 1ed85084298 Ref: library/curses ascii curses ascii isgraph5084462 Ref: 1ed95084462 Ref: library/curses ascii curses ascii islower5084563 Ref: 1eda5084563 Ref: library/curses ascii curses ascii isprint5084651 Ref: 1edb5084651 Ref: library/curses ascii curses ascii ispunct5084755 Ref: 1edc5084755 Ref: library/curses ascii curses ascii isspace5084898 Ref: 1edd5084898 Ref: library/curses ascii curses ascii isupper5085066 Ref: 1ede5085066 Ref: library/curses ascii curses ascii isxdigit5085150 Ref: 1edf5085150 Ref: library/curses ascii curses ascii isctrl5085293 Ref: 1ee05085293 Ref: library/curses ascii curses ascii ismeta5085402 Ref: 1ee15085402 Ref: library/curses ascii curses ascii ascii5086002 Ref: 1ee25086002 Ref: library/curses ascii curses ascii ctrl5086109 Ref: 1ee35086109 Ref: library/curses ascii curses ascii alt5086277 Ref: 1ee45086277 Ref: library/curses ascii curses ascii unctrl5086549 Ref: 1ee55086549 Ref: library/curses ascii curses ascii controlnames5087104 Ref: 1ee65087104 Node: curses panel — A panel stack extension for curses5087350 Ref: library/curses panel doc5087599 Ref: 1ee75087599 Ref: library/curses panel curses-panel-a-panel-stack-extension-for-curses5087599 Ref: 1ee85087599 Ref: library/curses panel module-curses panel5087599 Ref: 2e5087599 Node: Functions<4>5088077 Ref: library/curses panel cursespanel-functions5088199 Ref: 1ee95088199 Ref: library/curses panel functions5088199 Ref: 1eea5088199 Ref: library/curses panel curses panel bottom_panel5088309 Ref: 1eeb5088309 Ref: library/curses panel curses panel new_panel5088404 Ref: 1eec5088404 Ref: library/curses panel curses panel top_panel5088706 Ref: 1eed5088706 Ref: library/curses panel curses panel update_panels5088795 Ref: 1eee5088795 Node: Panel Objects5089006 Ref: library/curses panel curses-panel-objects5089128 Ref: 1eef5089128 Ref: library/curses panel panel-objects5089128 Ref: 1ef05089128 Ref: library/curses panel curses panel Panel above5089484 Ref: 1ef15089484 Ref: library/curses panel curses panel Panel below5089561 Ref: 1ef25089561 Ref: library/curses panel curses panel Panel bottom5089638 Ref: 1ef35089638 Ref: library/curses panel curses panel Panel hidden5089716 Ref: 1ef45089716 Ref: library/curses panel curses panel Panel hide5089836 Ref: 1ef55089836 Ref: library/curses panel curses panel Panel move5089970 Ref: 1ef65089970 Ref: library/curses panel curses panel Panel replace5090062 Ref: 1ef75090062 Ref: library/curses panel curses panel Panel set_userptr5090166 Ref: 1ef85090166 Ref: library/curses panel curses panel Panel show5090360 Ref: 1ef95090360 Ref: library/curses panel curses panel Panel top5090443 Ref: 1efa5090443 Ref: library/curses panel curses panel Panel userptr5090511 Ref: 1efb5090511 Ref: library/curses panel curses panel Panel window5090626 Ref: 1efc5090626 Node: platform — Access to underlying platform’s identifying data5090714 Ref: library/platform doc5090955 Ref: 1efd5090955 Ref: library/platform module-platform5090955 Ref: ce5090955 Ref: library/platform platform-access-to-underlying-platform-s-identifying-data5090955 Ref: 1efe5090955 Ref: platform — Access to underlying platform’s identifying data-Footnote-15091450 Node: Cross Platform5091517 Ref: library/platform cross-platform5091653 Ref: 1eff5091653 Ref: library/platform platform architecture5091704 Ref: 1f005091704 Ref: library/platform platform machine5093045 Ref: 1f015093045 Ref: library/platform platform node5093201 Ref: 1f025093201 Ref: library/platform platform platform5093376 Ref: 1f035093376 Ref: library/platform platform processor5094311 Ref: 1f065094311 Ref: library/platform platform python_build5094632 Ref: 1f075094632 Ref: library/platform platform python_compiler5094779 Ref: 1f085094779 Ref: library/platform platform python_branch5094902 Ref: 1f095094902 Ref: library/platform platform python_implementation5095016 Ref: 1f0a5095016 Ref: library/platform platform python_revision5095220 Ref: 1f0b5095220 Ref: library/platform platform python_version5095343 Ref: 1f0c5095343 Ref: library/platform platform python_version_tuple5095592 Ref: 1f0d5095592 Ref: library/platform platform release5095872 Ref: 1f0e5095872 Ref: library/platform platform system5096047 Ref: 1f0f5096047 Ref: library/platform platform system_alias5096259 Ref: 1f045096259 Ref: library/platform platform version5096542 Ref: 1f105096542 Ref: library/platform platform uname5096719 Ref: 1f115096719 Node: Java Platform5097412 Ref: library/platform java-platform5097573 Ref: 1f125097573 Ref: library/platform platform java_ver5097622 Ref: 1f135097622 Node: Windows Platform5098093 Ref: library/platform windows-platform5098255 Ref: 1f145098255 Ref: library/platform platform win32_ver5098310 Ref: 1f155098310 Ref: library/platform platform win32_edition5099009 Ref: 1f165099009 Ref: library/platform platform win32_is_iot5099282 Ref: 1f175099282 Node: Mac OS Platform5099474 Ref: library/platform mac-os-platform5099637 Ref: 1f185099637 Ref: library/platform platform mac_ver5099690 Ref: 1f055099690 Node: Unix Platforms5100072 Ref: library/platform unix-platforms5100210 Ref: 1f195100210 Ref: library/platform platform libc_ver5100261 Ref: 1f1a5100261 Node: errno — Standard errno system symbols5100878 Ref: library/errno doc5101116 Ref: 1f1b5101116 Ref: library/errno errno-standard-errno-system-symbols5101116 Ref: 1f1c5101116 Ref: library/errno module-errno5101116 Ref: 7c5101116 Ref: library/errno errno errorcode5101528 Ref: 1f1d5101528 Ref: library/errno errno EPERM5102049 Ref: 1f1e5102049 Ref: library/errno errno ENOENT5102102 Ref: 1f1f5102102 Ref: library/errno errno ESRCH5102158 Ref: 1f205102158 Ref: library/errno errno EINTR5102203 Ref: 6585102203 Ref: library/errno errno EIO5102359 Ref: 1f215102359 Ref: library/errno errno ENXIO5102396 Ref: 1f225102396 Ref: library/errno errno E2BIG5102451 Ref: 1f235102451 Ref: library/errno errno ENOEXEC5102498 Ref: 1f245102498 Ref: library/errno errno EBADF5102547 Ref: 1f255102547 Ref: library/errno errno ECHILD5102592 Ref: 1f265102592 Ref: library/errno errno EAGAIN5102641 Ref: 1c0c5102641 Ref: library/errno errno ENOMEM5102681 Ref: 1f275102681 Ref: library/errno errno EACCES5102725 Ref: 1f285102725 Ref: library/errno errno EFAULT5102773 Ref: 1f295102773 Ref: library/errno errno ENOTBLK5102815 Ref: 1f2a5102815 Ref: library/errno errno EBUSY5102868 Ref: 1f2b5102868 Ref: library/errno errno EEXIST5102921 Ref: 1f2c5102921 Ref: library/errno errno EXDEV5102963 Ref: 1be05102963 Ref: library/errno errno ENODEV5103010 Ref: 1f2d5103010 Ref: library/errno errno ENOTDIR5103055 Ref: 1f2e5103055 Ref: library/errno errno EISDIR5103102 Ref: 1f2f5103102 Ref: library/errno errno EINVAL5103147 Ref: 1be45103147 Ref: library/errno errno ENFILE5103194 Ref: 1f305103194 Ref: library/errno errno EMFILE5103244 Ref: 1f315103244 Ref: library/errno errno ENOTTY5103294 Ref: 1f325103294 Ref: library/errno errno ETXTBSY5103341 Ref: 1f335103341 Ref: library/errno errno EFBIG5103387 Ref: 1f345103387 Ref: library/errno errno ENOSPC5103431 Ref: 1f355103431 Ref: library/errno errno ESPIPE5103485 Ref: 1f365103485 Ref: library/errno errno EROFS5103528 Ref: 1f375103528 Ref: library/errno errno EMLINK5103579 Ref: 1f385103579 Ref: library/errno errno EPIPE5103624 Ref: 1f395103624 Ref: library/errno errno EDOM5103665 Ref: 1f3a5103665 Ref: library/errno errno ERANGE5103729 Ref: 1f3b5103729 Ref: library/errno errno EDEADLK5103789 Ref: 1f3c5103789 Ref: library/errno errno ENAMETOOLONG5103850 Ref: 1f3d5103850 Ref: library/errno errno ENOLCK5103905 Ref: 1f3e5103905 Ref: library/errno errno ENOSYS5103961 Ref: 1f3f5103961 Ref: library/errno errno ENOTEMPTY5104016 Ref: 1f405104016 Ref: library/errno errno ELOOP5104069 Ref: 1f415104069 Ref: library/errno errno EWOULDBLOCK5104134 Ref: 1f425104134 Ref: library/errno errno ENOMSG5104191 Ref: 1f435104191 Ref: library/errno errno EIDRM5104248 Ref: 1f445104248 Ref: library/errno errno ECHRNG5104296 Ref: 1f455104296 Ref: library/errno errno EL2NSYNC5104354 Ref: 1f465104354 Ref: library/errno errno EL3HLT5104411 Ref: 1f475104411 Ref: library/errno errno EL3RST5104456 Ref: 1f485104456 Ref: library/errno errno ELNRNG5104500 Ref: 1f495104500 Ref: library/errno errno EUNATCH5104555 Ref: 1f4a5104555 Ref: library/errno errno ENOCSI5104615 Ref: 1f4b5104615 Ref: library/errno errno EL2HLT5104672 Ref: 1f4c5104672 Ref: library/errno errno EBADE5104717 Ref: 1f4d5104717 Ref: library/errno errno EBADR5104763 Ref: 1f4e5104763 Ref: library/errno errno EXFULL5104819 Ref: 1f4f5104819 Ref: library/errno errno ENOANO5104863 Ref: 1f505104863 Ref: library/errno errno EBADRQC5104902 Ref: 1f515104902 Ref: library/errno errno EBADSLT5104954 Ref: 1f525104954 Ref: library/errno errno EDEADLOCK5104998 Ref: 1f535104998 Ref: library/errno errno EBFONT5105059 Ref: 1f545105059 Ref: library/errno errno ENOSTR5105110 Ref: 1f555105110 Ref: library/errno errno ENODATA5105160 Ref: 1f565105160 Ref: library/errno errno ETIME5105209 Ref: 1f575105209 Ref: library/errno errno ENOSR5105252 Ref: 1f585105252 Ref: library/errno errno ENONET5105306 Ref: 1f595105306 Ref: library/errno errno ENOPKG5105366 Ref: 1f5a5105366 Ref: library/errno errno EREMOTE5105418 Ref: 1f5b5105418 Ref: library/errno errno ENOLINK5105466 Ref: 1f5c5105466 Ref: library/errno errno EADV5105519 Ref: 1f5d5105519 Ref: library/errno errno ESRMNT5105563 Ref: 1f5e5105563 Ref: library/errno errno ECOMM5105607 Ref: 1f5f5105607 Ref: library/errno errno EPROTO5105664 Ref: 1f605105664 Ref: library/errno errno EMULTIHOP5105709 Ref: 1f615105709 Ref: library/errno errno EDOTDOT5105761 Ref: 1f625105761 Ref: library/errno errno EBADMSG5105811 Ref: 1f635105811 Ref: library/errno errno EOVERFLOW5105861 Ref: 1f645105861 Ref: library/errno errno ENOTUNIQ5105932 Ref: 1f655105932 Ref: library/errno errno EBADFD5105991 Ref: 1f665105991 Ref: library/errno errno EREMCHG5106050 Ref: 1f675106050 Ref: library/errno errno ELIBACC5106104 Ref: 1f685106104 Ref: library/errno errno ELIBBAD5106174 Ref: 1f695106174 Ref: library/errno errno ELIBSCN5106242 Ref: 1f6a5106242 Ref: library/errno errno ELIBMAX5106305 Ref: 1f6b5106305 Ref: library/errno errno ELIBEXEC5106384 Ref: 1f6c5106384 Ref: library/errno errno EILSEQ5106454 Ref: 1f6d5106454 Ref: library/errno errno ERESTART5106506 Ref: 1f6e5106506 Ref: library/errno errno ESTRPIPE5106582 Ref: 1f6f5106582 Ref: library/errno errno EUSERS5106633 Ref: 1f705106633 Ref: library/errno errno ENOTSOCK5106678 Ref: 1f715106678 Ref: library/errno errno EDESTADDRREQ5106741 Ref: 1f725106741 Ref: library/errno errno EMSGSIZE5106806 Ref: 1f735106806 Ref: library/errno errno EPROTOTYPE5106855 Ref: 1f745106855 Ref: library/errno errno ENOPROTOOPT5106920 Ref: 1f755106920 Ref: library/errno errno EPROTONOSUPPORT5106978 Ref: 1f765106978 Ref: library/errno errno ESOCKTNOSUPPORT5107040 Ref: 1f775107040 Ref: library/errno errno EOPNOTSUPP5107105 Ref: 1f785107105 Ref: library/errno errno EPFNOSUPPORT5107185 Ref: 1f795107185 Ref: library/errno errno EAFNOSUPPORT5107251 Ref: 1f7a5107251 Ref: library/errno errno EADDRINUSE5107328 Ref: 1f7b5107328 Ref: library/errno errno EADDRNOTAVAIL5107385 Ref: 1f7c5107385 Ref: library/errno errno ENETDOWN5107454 Ref: 1f7d5107454 Ref: library/errno errno ENETUNREACH5107502 Ref: 1f7e5107502 Ref: library/errno errno ENETRESET5107560 Ref: 1f7f5107560 Ref: library/errno errno ECONNABORTED5107637 Ref: 1f805107637 Ref: library/errno errno ECONNRESET5107706 Ref: 1f815107706 Ref: library/errno errno ENOBUFS5107765 Ref: 1f825107765 Ref: library/errno errno EISCONN5107822 Ref: 1f835107822 Ref: library/errno errno ENOTCONN5107893 Ref: 1f845107893 Ref: library/errno errno ESHUTDOWN5107961 Ref: 1f855107961 Ref: library/errno errno ETOOMANYREFS5108040 Ref: 1f865108040 Ref: library/errno errno ETIMEDOUT5108111 Ref: 1f875108111 Ref: library/errno errno ECONNREFUSED5108165 Ref: 1f885108165 Ref: library/errno errno EHOSTDOWN5108220 Ref: 1f895108220 Ref: library/errno errno EHOSTUNREACH5108266 Ref: 1f8a5108266 Ref: library/errno errno EALREADY5108319 Ref: 1f8b5108319 Ref: library/errno errno EINPROGRESS5108381 Ref: 1f8c5108381 Ref: library/errno errno ESTALE5108442 Ref: 1f8d5108442 Ref: library/errno errno EUCLEAN5108494 Ref: 1f8e5108494 Ref: library/errno errno ENOTNAM5108550 Ref: 1f8f5108550 Ref: library/errno errno ENAVAIL5108609 Ref: 1f905108609 Ref: library/errno errno EISNAM5108670 Ref: 1f915108670 Ref: library/errno errno EREMOTEIO5108721 Ref: 1f925108721 Ref: library/errno errno EDQUOT5108771 Ref: 1f935108771 Node: ctypes — A foreign function library for Python5108816 Ref: library/ctypes doc5108982 Ref: 1f945108982 Ref: library/ctypes ctypes-a-foreign-function-library-for-python5108982 Ref: 1f955108982 Ref: library/ctypes module-ctypes5108982 Ref: 2b5108982 Node: ctypes tutorial5109435 Ref: library/ctypes ctypes-ctypes-tutorial5109560 Ref: 1f965109560 Ref: library/ctypes ctypes-tutorial5109560 Ref: 1f975109560 Node: Loading dynamic link libraries5110929 Ref: library/ctypes ctypes-loading-dynamic-link-libraries5111056 Ref: 1f9a5111056 Ref: library/ctypes loading-dynamic-link-libraries5111056 Ref: 1f9b5111056 Node: Accessing functions from loaded dlls5113102 Ref: library/ctypes accessing-functions-from-loaded-dlls5113255 Ref: 1f9c5113255 Ref: library/ctypes ctypes-accessing-functions-from-loaded-dlls5113255 Ref: 1f9d5113255 Node: Calling functions5115510 Ref: library/ctypes calling-functions5115655 Ref: 1f9e5115655 Ref: library/ctypes ctypes-calling-functions5115655 Ref: 1f9f5115655 Node: Fundamental data types5118127 Ref: library/ctypes ctypes-fundamental-data-types5118263 Ref: 1fa05118263 Ref: library/ctypes fundamental-data-types5118263 Ref: 1fa15118263 Node: Calling functions continued5126309 Ref: library/ctypes calling-functions-continued5126477 Ref: 1fb65126477 Ref: library/ctypes ctypes-calling-functions-continued5126477 Ref: 1fb75126477 Node: Calling functions with your own custom data types5127561 Ref: library/ctypes calling-functions-with-your-own-custom-data-types5127765 Ref: 1fb85127765 Ref: library/ctypes ctypes-calling-functions-with-own-custom-data-types5127765 Ref: 1fb95127765 Node: Specifying the required argument types function prototypes5128608 Ref: library/ctypes ctypes-specifying-required-argument-types5128797 Ref: 1fba5128797 Ref: library/ctypes specifying-the-required-argument-types-function-prototypes5128797 Ref: 1fbb5128797 Node: Return types5130623 Ref: library/ctypes ctypes-return-types5130814 Ref: 1fbc5130814 Ref: library/ctypes return-types5130814 Ref: 1fbd5130814 Node: Passing pointers or passing parameters by reference5133443 Ref: library/ctypes ctypes-passing-pointers5133597 Ref: 1fbf5133597 Ref: library/ctypes passing-pointers-or-passing-parameters-by-reference5133597 Ref: 1fc05133597 Node: Structures and unions5134691 Ref: library/ctypes ctypes-structures-unions5134873 Ref: 1fc35134873 Ref: library/ctypes structures-and-unions5134873 Ref: 1fc45134873 Ref: library/ctypes ctypes-structureunion-alignment-byte-order5136959 Ref: 1fc75136959 Node: Structure/union alignment and byte order5137287 Ref: library/ctypes structure-union-alignment-and-byte-order5137453 Ref: 1fc85137453 Node: Bit fields in structures and unions5138233 Ref: library/ctypes bit-fields-in-structures-and-unions5138384 Ref: 1fcb5138384 Ref: library/ctypes ctypes-bit-fields-in-structures-unions5138384 Ref: 1fcc5138384 Node: Arrays5138971 Ref: library/ctypes arrays5139090 Ref: 1fcd5139090 Ref: library/ctypes ctypes-arrays5139090 Ref: 1fce5139090 Node: Pointers5140379 Ref: library/ctypes ctypes-pointers5140479 Ref: 1fcf5140479 Ref: library/ctypes pointers5140479 Ref: 1fd05140479 Node: Type conversions5143142 Ref: library/ctypes ctypes-type-conversions5143252 Ref: 1fd35143252 Ref: library/ctypes type-conversions5143252 Ref: 1fd45143252 Node: Incomplete Types5145854 Ref: library/ctypes ctypes-incomplete-types5145974 Ref: 1fd65145974 Ref: library/ctypes incomplete-types5145974 Ref: 1fd75145974 Node: Callback functions5147581 Ref: library/ctypes callback-functions5147720 Ref: 1fd85147720 Ref: library/ctypes ctypes-callback-functions5147720 Ref: 1fd95147720 Node: Accessing values exported from dlls5151594 Ref: library/ctypes accessing-values-exported-from-dlls5151726 Ref: 1fdd5151726 Ref: library/ctypes ctypes-accessing-values-exported-from-dlls5151726 Ref: 1fde5151726 Node: Surprises5154529 Ref: library/ctypes ctypes-surprises5154668 Ref: 1fe15154668 Ref: library/ctypes surprises5154668 Ref: 1fe25154668 Node: Variable-sized data types5156843 Ref: library/ctypes ctypes-variable-sized-data-types5156938 Ref: 1fe35156938 Ref: library/ctypes variable-sized-data-types5156938 Ref: 1fe45156938 Node: ctypes reference5158341 Ref: library/ctypes ctypes-ctypes-reference5158466 Ref: 1fe65158466 Ref: library/ctypes ctypes-reference5158466 Ref: 1fe75158466 Node: Finding shared libraries5158777 Ref: library/ctypes ctypes-finding-shared-libraries5158887 Ref: 1fe85158887 Ref: library/ctypes finding-shared-libraries5158887 Ref: 1fe95158887 Node: Loading shared libraries5161412 Ref: library/ctypes ctypes-loading-shared-libraries5161548 Ref: 1fea5161548 Ref: library/ctypes loading-shared-libraries5161548 Ref: 1feb5161548 Ref: library/ctypes ctypes CDLL5161751 Ref: 1c15161751 Ref: library/ctypes ctypes OleDLL5162788 Ref: 1fec5162788 Ref: library/ctypes ctypes WinDLL5163478 Ref: 1fee5163478 Ref: library/ctypes ctypes PyDLL5164149 Ref: 1fef5164149 Ref: library/ctypes ctypes PyDLL _handle5167872 Ref: 1ff45167872 Ref: library/ctypes ctypes PyDLL _name5167954 Ref: 1ff55167954 Ref: library/ctypes ctypes LibraryLoader5168296 Ref: 1ff65168296 Ref: library/ctypes ctypes LibraryLoader LoadLibrary5168761 Ref: 1ff75168761 Ref: Loading shared libraries-Footnote-15170336 Node: Foreign functions5170402 Ref: library/ctypes ctypes-foreign-functions5170533 Ref: 1ff85170533 Ref: library/ctypes foreign-functions5170533 Ref: 1ff95170533 Ref: library/ctypes ctypes _FuncPtr5170947 Ref: 1ffa5170947 Ref: library/ctypes ctypes _FuncPtr restype5171248 Ref: 1ffb5171248 Ref: library/ctypes ctypes _FuncPtr argtypes5171944 Ref: 1ffd5171944 Ref: library/ctypes ctypes _FuncPtr errcheck5173183 Ref: 1ffc5173183 Ref: library/ctypes ctypes ArgumentError5174169 Ref: 1ffe5174169 Node: Function prototypes5174809 Ref: library/ctypes ctypes-function-prototypes5174933 Ref: 1fff5174933 Ref: library/ctypes function-prototypes5174933 Ref: 20005174933 Ref: library/ctypes ctypes CFUNCTYPE5175516 Ref: 1fda5175516 Ref: library/ctypes ctypes WINFUNCTYPE5176027 Ref: 1fdb5176027 Ref: library/ctypes ctypes PYFUNCTYPE5176479 Ref: 20015176479 Node: Utility functions5182112 Ref: library/ctypes ctypes-utility-functions5182229 Ref: 20025182229 Ref: library/ctypes utility-functions5182229 Ref: 20035182229 Ref: library/ctypes ctypes addressof5182288 Ref: 20045182288 Ref: library/ctypes ctypes alignment5182531 Ref: 20055182531 Ref: library/ctypes ctypes byref5182691 Ref: 1fc15182691 Ref: library/ctypes ctypes cast5183205 Ref: 1fd55183205 Ref: library/ctypes ctypes create_string_buffer5183499 Ref: 1fb45183499 Ref: library/ctypes ctypes create_unicode_buffer5184304 Ref: 1fb55184304 Ref: library/ctypes ctypes DllCanUnloadNow5185123 Ref: 20065185123 Ref: library/ctypes ctypes DllGetClassObject5185368 Ref: 20075185368 Ref: library/ctypes ctypes util find_library5185628 Ref: 60a5185628 Ref: library/ctypes ctypes util find_msvcrt5186020 Ref: 20085186020 Ref: library/ctypes ctypes FormatError5186476 Ref: 20095186476 Ref: library/ctypes ctypes GetLastError5186715 Ref: 1fbe5186715 Ref: library/ctypes ctypes get_errno5186989 Ref: 1ff05186989 Ref: library/ctypes ctypes get_last_error5187241 Ref: 1ff25187241 Ref: library/ctypes ctypes memmove5187516 Ref: 200a5187516 Ref: library/ctypes ctypes memset5187760 Ref: 200b5187760 Ref: library/ctypes ctypes POINTER5188013 Ref: 1fd25188013 Ref: library/ctypes ctypes pointer5188261 Ref: 1fc25188261 Ref: library/ctypes ctypes resize5188581 Ref: 1fe55188581 Ref: library/ctypes ctypes set_errno5188919 Ref: 1ff15188919 Ref: library/ctypes ctypes set_last_error5189226 Ref: 1ff35189226 Ref: library/ctypes ctypes sizeof5189556 Ref: 200c5189556 Ref: library/ctypes ctypes string_at5189727 Ref: 200d5189727 Ref: library/ctypes ctypes WinError5190096 Ref: 200e5190096 Ref: library/ctypes ctypes wstring_at5190577 Ref: 200f5190577 Node: Data types5190996 Ref: library/ctypes ctypes-data-types5191119 Ref: 20105191119 Ref: library/ctypes data-types5191119 Ref: 20115191119 Ref: library/ctypes ctypes _CData5191164 Ref: 20125191164 Ref: library/ctypes ctypes _CData from_buffer5191799 Ref: 20155191799 Ref: library/ctypes ctypes _CData from_buffer_copy5192385 Ref: 20165192385 Ref: library/ctypes ctypes _CData from_address5192929 Ref: 20175192929 Ref: library/ctypes ctypes _CData from_param5193274 Ref: 20185193274 Ref: library/ctypes ctypes _CData in_dll5193828 Ref: 20195193828 Ref: library/ctypes ctypes _CData _b_base_5194124 Ref: 201a5194124 Ref: library/ctypes ctypes _CData _b_needsfree_5194429 Ref: 201b5194429 Ref: library/ctypes ctypes _CData _objects5194603 Ref: 20135194603 Node: Fundamental data types<2>5194915 Ref: library/ctypes ctypes-fundamental-data-types-25195042 Ref: 201c5195042 Ref: library/ctypes id15195042 Ref: 201d5195042 Ref: library/ctypes ctypes _SimpleCData5195111 Ref: 201e5195111 Ref: library/ctypes ctypes _SimpleCData value5195584 Ref: 201f5195584 Ref: library/ctypes ctypes c_byte5196939 Ref: 1fa55196939 Ref: library/ctypes ctypes c_char5197157 Ref: 1fa35197157 Ref: library/ctypes ctypes c_char_p5197403 Ref: 1fb15197403 Ref: library/ctypes ctypes c_double5197704 Ref: 1faf5197704 Ref: library/ctypes ctypes c_longdouble5197839 Ref: 1fb05197839 Ref: library/ctypes ctypes c_float5198092 Ref: 1fae5198092 Ref: library/ctypes ctypes c_int5198225 Ref: 1f985198225 Ref: library/ctypes ctypes c_int85198495 Ref: 20205198495 Ref: library/ctypes ctypes c_int165198624 Ref: 20215198624 Ref: library/ctypes ctypes c_int325198756 Ref: 20225198756 Ref: library/ctypes ctypes c_int645198886 Ref: 20235198886 Ref: library/ctypes ctypes c_long5199021 Ref: 1f995199021 Ref: library/ctypes ctypes c_longlong5199191 Ref: 1fab5199191 Ref: library/ctypes ctypes c_short5199375 Ref: 1fa75199375 Ref: library/ctypes ctypes c_size_t5199547 Ref: 1fad5199547 Ref: library/ctypes ctypes c_ssize_t5199621 Ref: bd15199621 Ref: library/ctypes ctypes c_ubyte5199723 Ref: 1fa65199723 Ref: library/ctypes ctypes c_uint5199943 Ref: 1fa95199943 Ref: library/ctypes ctypes c_uint85200218 Ref: 20245200218 Ref: library/ctypes ctypes c_uint165200351 Ref: 20255200351 Ref: library/ctypes ctypes c_uint325200487 Ref: 20265200487 Ref: library/ctypes ctypes c_uint645200621 Ref: 20275200621 Ref: library/ctypes ctypes c_ulong5200760 Ref: 1faa5200760 Ref: library/ctypes ctypes c_ulonglong5200933 Ref: 1fac5200933 Ref: library/ctypes ctypes c_ushort5201120 Ref: 1fa85201120 Ref: library/ctypes ctypes c_void_p5201300 Ref: 1fb35201300 Ref: library/ctypes ctypes c_wchar5201471 Ref: 1fa45201471 Ref: library/ctypes ctypes c_wchar_p5201736 Ref: 1fb25201736 Ref: library/ctypes ctypes c_bool5201950 Ref: 1fa25201950 Ref: library/ctypes ctypes HRESULT5202177 Ref: 1fed5202177 Ref: library/ctypes ctypes py_object5202338 Ref: 20285202338 Node: Structured data types5202734 Ref: library/ctypes ctypes-structured-data-types5202870 Ref: 20295202870 Ref: library/ctypes structured-data-types5202870 Ref: 202a5202870 Ref: library/ctypes ctypes Union5202937 Ref: 1fc65202937 Ref: library/ctypes ctypes BigEndianStructure5203035 Ref: 1fc95203035 Ref: library/ctypes ctypes LittleEndianStructure5203156 Ref: 1fca5203156 Ref: library/ctypes ctypes Structure5203414 Ref: 1fc55203414 Ref: library/ctypes ctypes Structure _fields_5203838 Ref: 202b5203838 Ref: library/ctypes ctypes Structure _pack_5205432 Ref: 202c5205432 Ref: library/ctypes ctypes Structure _anonymous_5205720 Ref: 202d5205720 Node: Arrays and pointers5208076 Ref: library/ctypes arrays-and-pointers5208178 Ref: 202e5208178 Ref: library/ctypes ctypes-arrays-pointers5208178 Ref: 202f5208178 Ref: library/ctypes ctypes Array5208241 Ref: 20305208241 Ref: library/ctypes ctypes Array _length_5208751 Ref: 20315208751 Ref: library/ctypes ctypes Array _type_5208979 Ref: 20325208979 Ref: library/ctypes ctypes _Pointer5209177 Ref: 20335209177 Ref: library/ctypes ctypes _Pointer _type_5209835 Ref: 20345209835 Ref: library/ctypes ctypes _Pointer contents5209905 Ref: 1fd15209905 Node: Concurrent Execution5210095 Ref: library/concurrency doc5210271 Ref: 20355210271 Ref: library/concurrency concurrency5210271 Ref: 20365210271 Ref: library/concurrency concurrent-execution5210271 Ref: 20375210271 Node: threading — Thread-based parallelism5211376 Ref: library/threading doc5211525 Ref: 20385211525 Ref: library/threading module-threading5211525 Ref: 1095211525 Ref: library/threading threading-thread-based-parallelism5211525 Ref: 20395211525 Ref: library/threading threading active_count5212746 Ref: 203a5212746 Ref: library/threading threading current_thread5212959 Ref: 203c5212959 Ref: library/threading threading excepthook5213277 Ref: 2315213277 Ref: library/threading threading get_ident5214611 Ref: aaf5214611 Ref: library/threading threading get_native_id5215005 Ref: 2335215005 Ref: library/threading threading enumerate5215465 Ref: 203b5215465 Ref: library/threading threading main_thread5215784 Ref: 8ef5215784 Ref: library/threading threading settrace5216009 Ref: 203d5216009 Ref: library/threading threading setprofile5216276 Ref: 203e5216276 Ref: library/threading threading stack_size5216549 Ref: 203f5216549 Ref: library/threading threading TIMEOUT_MAX5217843 Ref: 20405217843 Ref: threading — Thread-based parallelism-Footnote-15219200 Node: Thread-Local Data5219268 Ref: library/threading thread-local-data5219383 Ref: 20425219383 Ref: library/threading threading local5219735 Ref: 1fdc5219735 Node: Thread Objects5219931 Ref: library/threading id15220067 Ref: 20435220067 Ref: library/threading thread-objects5220067 Ref: 20445220067 Ref: library/threading threading Thread5222747 Ref: 2355222747 Ref: library/threading threading Thread start5223981 Ref: 1db35223981 Ref: library/threading threading Thread run5224358 Ref: 2325224358 Ref: library/threading threading Thread join5224770 Ref: b605224770 Ref: library/threading threading Thread name5226050 Ref: 20465226050 Ref: library/threading threading Thread getName5226268 Ref: 20485226268 Ref: library/threading threading Thread setName5226296 Ref: 20495226296 Ref: library/threading threading Thread ident5226430 Ref: 1cf45226430 Ref: library/threading threading Thread native_id5226821 Ref: 2345226821 Ref: library/threading threading Thread is_alive5227680 Ref: 20455227680 Ref: library/threading threading Thread daemon5228018 Ref: 20475228018 Ref: library/threading threading Thread isDaemon5228601 Ref: 204a5228601 Ref: library/threading threading Thread setDaemon5228630 Ref: 204b5228630 Node: Lock Objects5228768 Ref: library/threading id25228900 Ref: 204c5228900 Ref: library/threading lock-objects5228900 Ref: 204d5228900 Ref: library/threading threading Lock5230317 Ref: 20505230317 Ref: library/threading threading Lock acquire5230719 Ref: 76c5230719 Ref: library/threading threading Lock release5232050 Ref: 204e5232050 Ref: library/threading threading Lock locked5232535 Ref: 20515232535 Node: RLock Objects5232611 Ref: library/threading id35232746 Ref: 20525232746 Ref: library/threading rlock-objects5232746 Ref: 20535232746 Ref: library/threading threading RLock5233656 Ref: bef5233656 Ref: library/threading threading RLock acquire5234178 Ref: 76d5234178 Ref: library/threading threading RLock release5235705 Ref: 20545235705 Node: Condition Objects5236398 Ref: library/threading condition-objects5236538 Ref: 20555236538 Ref: library/threading id45236538 Ref: 20565236538 Ref: library/threading threading Condition5239663 Ref: aaa5239663 Ref: library/threading threading Condition acquire5240206 Ref: 20575240206 Ref: library/threading threading Condition release5240418 Ref: 20585240418 Ref: library/threading threading Condition wait5240601 Ref: 20415240601 Ref: library/threading threading Condition wait_for5242132 Ref: 205b5242132 Ref: library/threading threading Condition notify5243104 Ref: 20595243104 Ref: library/threading threading Condition notify_all5244006 Ref: 205a5244006 Node: Semaphore Objects5244345 Ref: library/threading id55244485 Ref: 205c5244485 Ref: library/threading semaphore-objects5244485 Ref: 205d5244485 Ref: library/threading threading Semaphore5245181 Ref: aab5245181 Ref: library/threading threading Semaphore acquire5245870 Ref: bec5245870 Ref: library/threading threading Semaphore release5247159 Ref: 205e5247159 Ref: library/threading threading BoundedSemaphore5247400 Ref: aac5247400 Node: Semaphore Example5247963 Ref: library/threading semaphore-example5248034 Ref: 205f5248034 Ref: library/threading semaphore-examples5248034 Ref: 20605248034 Node: Event Objects5248903 Ref: library/threading event-objects5249039 Ref: 20615249039 Ref: library/threading id65249039 Ref: 20625249039 Ref: library/threading threading Event5249440 Ref: aad5249440 Ref: library/threading threading Event is_set5249830 Ref: 20655249830 Ref: library/threading threading Event set5249929 Ref: 20635249929 Ref: library/threading threading Event clear5250156 Ref: 20645250156 Ref: library/threading threading Event wait5250384 Ref: cb75250384 Node: Timer Objects5251259 Ref: library/threading id75251393 Ref: 20665251393 Ref: library/threading timer-objects5251393 Ref: 20675251393 Ref: library/threading threading Timer5252142 Ref: aae5252142 Ref: library/threading threading Timer cancel5252591 Ref: 20685252591 Node: Barrier Objects5252781 Ref: library/threading barrier-objects5252961 Ref: 20695252961 Ref: library/threading threading Barrier5253916 Ref: b5f5253916 Ref: library/threading threading Barrier wait5254260 Ref: 206a5254260 Ref: library/threading threading Barrier reset5255407 Ref: 206b5255407 Ref: library/threading threading Barrier abort5255843 Ref: 206c5255843 Ref: library/threading threading Barrier parties5256332 Ref: 206d5256332 Ref: library/threading threading Barrier n_waiting5256424 Ref: 206e5256424 Ref: library/threading threading Barrier broken5256522 Ref: 206f5256522 Ref: library/threading threading BrokenBarrierError5256639 Ref: b615256639 Node: Using locks conditions and semaphores in the with statement5256816 Ref: library/threading using-locks-conditions-and-semaphores-in-the-with-statement5256974 Ref: 20705256974 Ref: library/threading with-locks5256974 Ref: 204f5256974 Node: multiprocessing — Process-based parallelism5257819 Ref: library/multiprocessing doc5258068 Ref: 20715258068 Ref: library/multiprocessing module-multiprocessing5258068 Ref: b75258068 Ref: library/multiprocessing multiprocessing-process-based-parallelism5258068 Ref: 20725258068 Ref: multiprocessing — Process-based parallelism-Footnote-15258435 Node: Introduction<8>5258507 Ref: library/multiprocessing introduction5258622 Ref: 20735258622 Node: The Process class5260155 Ref: library/multiprocessing the-process-class5260259 Ref: 20745260259 Node: Contexts and start methods5261440 Ref: library/multiprocessing contexts-and-start-methods5261589 Ref: 20775261589 Ref: library/multiprocessing multiprocessing-start-methods5261662 Ref: 8765261662 Ref: Contexts and start methods-Footnote-15266140 Node: Exchanging objects between processes5266183 Ref: library/multiprocessing exchanging-objects-between-processes5266348 Ref: 207a5266348 Node: Synchronization between processes5268066 Ref: library/multiprocessing synchronization-between-processes5268236 Ref: 207d5268236 Node: Sharing state between processes5268957 Ref: library/multiprocessing sharing-state-between-processes5269114 Ref: 207e5269114 Node: Using a pool of workers5272199 Ref: library/multiprocessing using-a-pool-of-workers5272314 Ref: 20895272314 Node: Reference5275431 Ref: library/multiprocessing reference5275577 Ref: 208a5275577 Node: Process and exceptions5276106 Ref: library/multiprocessing process-and-exceptions5276199 Ref: 208b5276199 Ref: library/multiprocessing multiprocessing Process5276272 Ref: 3b25276272 Ref: library/multiprocessing multiprocessing Process run5277641 Ref: 20785277641 Ref: library/multiprocessing multiprocessing Process start5278053 Ref: 20755278053 Ref: library/multiprocessing multiprocessing Process join5278302 Ref: 208e5278302 Ref: library/multiprocessing multiprocessing Process name5279024 Ref: 208c5279024 Ref: library/multiprocessing multiprocessing Process is_alive5279489 Ref: 20905279489 Ref: library/multiprocessing multiprocessing Process daemon5279725 Ref: 208d5279725 Ref: library/multiprocessing multiprocessing Process pid5280606 Ref: 20915280606 Ref: library/multiprocessing multiprocessing Process exitcode5280731 Ref: 208f5280731 Ref: library/multiprocessing multiprocessing Process authkey5280959 Ref: 20925280959 Ref: library/multiprocessing multiprocessing Process sentinel5281487 Ref: a255281487 Ref: library/multiprocessing multiprocessing Process terminate5282124 Ref: 20945282124 Ref: library/multiprocessing multiprocessing Process kill5282926 Ref: 3b15282926 Ref: library/multiprocessing multiprocessing Process close5283081 Ref: 3b05283081 Ref: library/multiprocessing multiprocessing ProcessError5284319 Ref: 20955284319 Ref: library/multiprocessing multiprocessing BufferTooShort5284431 Ref: 20965284431 Ref: library/multiprocessing multiprocessing AuthenticationError5284740 Ref: 20975284740 Ref: library/multiprocessing multiprocessing TimeoutError5284844 Ref: 20985284844 Node: Pipes and Queues5284954 Ref: library/multiprocessing pipes-and-queues5285072 Ref: 20995285072 Ref: library/multiprocessing multiprocessing Pipe5288496 Ref: 207c5288496 Ref: library/multiprocessing multiprocessing Queue5288918 Ref: 207b5288918 Ref: library/multiprocessing multiprocessing Queue qsize5289516 Ref: 20a75289516 Ref: library/multiprocessing multiprocessing Queue empty5289866 Ref: 20a25289866 Ref: library/multiprocessing multiprocessing Queue full5290063 Ref: 20a85290063 Ref: library/multiprocessing multiprocessing Queue put5290258 Ref: 20a95290258 Ref: library/multiprocessing multiprocessing Queue put_nowait5291086 Ref: 20aa5291086 Ref: library/multiprocessing multiprocessing Queue get5291169 Ref: 20ab5291169 Ref: library/multiprocessing multiprocessing Queue get_nowait5291957 Ref: 20a35291957 Ref: library/multiprocessing multiprocessing Queue close5292203 Ref: 20ac5292203 Ref: library/multiprocessing multiprocessing Queue join_thread5292499 Ref: 20ad5292499 Ref: library/multiprocessing multiprocessing Queue cancel_join_thread5293050 Ref: 20a45293050 Ref: library/multiprocessing multiprocessing SimpleQueue5294195 Ref: 209a5294195 Ref: library/multiprocessing multiprocessing SimpleQueue empty5294331 Ref: 20ae5294331 Ref: library/multiprocessing multiprocessing SimpleQueue get5294433 Ref: 20af5294433 Ref: library/multiprocessing multiprocessing SimpleQueue put5294511 Ref: 20b05294511 Ref: library/multiprocessing multiprocessing JoinableQueue5294578 Ref: 209b5294578 Ref: library/multiprocessing multiprocessing JoinableQueue task_done5294798 Ref: 209e5294798 Ref: library/multiprocessing multiprocessing JoinableQueue join5295486 Ref: 20b15295486 Ref: Pipes and Queues-Footnote-15295990 Node: Miscellaneous<3>5296032 Ref: library/multiprocessing miscellaneous5296149 Ref: 20b25296149 Ref: library/multiprocessing multiprocessing active_children5296198 Ref: 20b35296198 Ref: library/multiprocessing multiprocessing cpu_count5296415 Ref: 8805296415 Ref: library/multiprocessing multiprocessing current_process5296796 Ref: 20b45296796 Ref: library/multiprocessing multiprocessing parent_process5296994 Ref: 20b55296994 Ref: library/multiprocessing multiprocessing freeze_support5297261 Ref: 20b65297261 Ref: library/multiprocessing multiprocessing get_all_start_methods5298297 Ref: 8775298297 Ref: library/multiprocessing multiprocessing get_context5298715 Ref: 87a5298715 Ref: library/multiprocessing multiprocessing get_start_method5299149 Ref: 8785299149 Ref: library/multiprocessing multiprocessing set_executable5299750 Ref: 20b75299750 Ref: library/multiprocessing multiprocessing set_start_method5300214 Ref: 8795300214 Node: Connection Objects<2>5300878 Ref: library/multiprocessing connection-objects5301005 Ref: 20b85301005 Ref: library/multiprocessing multiprocessing connection Connection5301324 Ref: 20a65301324 Ref: library/multiprocessing multiprocessing connection Connection send5301374 Ref: 20ba5301374 Ref: library/multiprocessing multiprocessing connection Connection recv5301701 Ref: 20bb5301701 Ref: library/multiprocessing multiprocessing connection Connection fileno5301993 Ref: 20bc5301993 Ref: library/multiprocessing multiprocessing connection Connection close5302093 Ref: 20bd5302093 Ref: library/multiprocessing multiprocessing connection Connection poll5302245 Ref: 20be5302245 Ref: library/multiprocessing multiprocessing connection Connection send_bytes5302731 Ref: 20bf5302731 Ref: library/multiprocessing multiprocessing connection Connection recv_bytes5303190 Ref: 20c05303190 Ref: library/multiprocessing multiprocessing connection Connection recv_bytes_into5303830 Ref: 20c15303830 Node: Synchronization primitives5306345 Ref: library/multiprocessing synchronization-primitives5306477 Ref: 20c25306477 Ref: library/multiprocessing multiprocessing Barrier5306848 Ref: 20885306848 Ref: library/multiprocessing multiprocessing BoundedSemaphore5307006 Ref: 20855307006 Ref: library/multiprocessing multiprocessing Condition5307507 Ref: 20865307507 Ref: library/multiprocessing multiprocessing Event5307841 Ref: 20875307841 Ref: library/multiprocessing multiprocessing Lock5307920 Ref: 20825307920 Ref: library/multiprocessing multiprocessing Lock acquire5308763 Ref: 20c35308763 Ref: library/multiprocessing multiprocessing Lock release5310289 Ref: 20c45310289 Ref: library/multiprocessing multiprocessing RLock5310658 Ref: 20835310658 Ref: library/multiprocessing multiprocessing RLock acquire5311389 Ref: 20c55311389 Ref: library/multiprocessing multiprocessing RLock release5313038 Ref: 20c65313038 Ref: library/multiprocessing multiprocessing Semaphore5314016 Ref: 20845314016 Ref: Synchronization primitives-Footnote-15315441 Node: Shared ctypes Objects5315483 Ref: library/multiprocessing shared-ctypes-objects5315602 Ref: 20c75315602 Ref: library/multiprocessing multiprocessing Value5315779 Ref: 207f5315779 Ref: library/multiprocessing multiprocessing Array5317208 Ref: 20805317208 Node: The multiprocessing sharedctypes module5318651 Ref: library/multiprocessing module-multiprocessing sharedctypes5318748 Ref: bd5318748 Ref: library/multiprocessing the-multiprocessing-sharedctypes-module5318748 Ref: 20c85318748 Ref: library/multiprocessing multiprocessing sharedctypes RawArray5319379 Ref: 20c95319379 Ref: library/multiprocessing multiprocessing sharedctypes RawValue5320208 Ref: 20cb5320208 Ref: library/multiprocessing multiprocessing sharedctypes Array5320992 Ref: 20ca5320992 Ref: library/multiprocessing multiprocessing sharedctypes Value5321759 Ref: 20cc5321759 Ref: library/multiprocessing multiprocessing sharedctypes copy5322510 Ref: 20cd5322510 Ref: library/multiprocessing multiprocessing sharedctypes synchronized5322672 Ref: 7195322672 Node: Managers5325688 Ref: library/multiprocessing managers5325794 Ref: 20ce5325794 Ref: library/multiprocessing multiprocessing-managers5325794 Ref: 209f5325794 Ref: library/multiprocessing multiprocessing sharedctypes multiprocessing Manager5326144 Ref: 20cf5326144 Ref: library/multiprocessing module-multiprocessing managers5326464 Ref: ba5326464 Ref: library/multiprocessing multiprocessing managers BaseManager5326654 Ref: 20d15326654 Ref: library/multiprocessing multiprocessing managers BaseManager start5327373 Ref: 20d25327373 Ref: library/multiprocessing multiprocessing managers BaseManager get_server5327608 Ref: 20d35327608 Ref: library/multiprocessing multiprocessing managers BaseManager connect5328152 Ref: 20d55328152 Ref: library/multiprocessing multiprocessing managers BaseManager shutdown5328433 Ref: 20d65328433 Ref: library/multiprocessing multiprocessing managers BaseManager register5328669 Ref: 20d75328669 Ref: library/multiprocessing multiprocessing managers BaseManager address5330985 Ref: 20d45330985 Ref: library/multiprocessing multiprocessing managers SyncManager5331516 Ref: 20d05331516 Ref: library/multiprocessing multiprocessing managers SyncManager Barrier5331951 Ref: 20da5331951 Ref: library/multiprocessing multiprocessing managers SyncManager BoundedSemaphore5332140 Ref: 20db5332140 Ref: library/multiprocessing multiprocessing managers SyncManager Condition5332295 Ref: 20dc5332295 Ref: library/multiprocessing multiprocessing managers SyncManager Event5332668 Ref: 20dd5332668 Ref: library/multiprocessing multiprocessing managers SyncManager Lock5332794 Ref: 20de5332794 Ref: library/multiprocessing multiprocessing managers SyncManager Namespace5332919 Ref: 20df5332919 Ref: library/multiprocessing multiprocessing managers SyncManager Queue5333044 Ref: 20e05333044 Ref: library/multiprocessing multiprocessing managers SyncManager RLock5333175 Ref: 20e15333175 Ref: library/multiprocessing multiprocessing managers SyncManager Semaphore5333301 Ref: 20e25333301 Ref: library/multiprocessing multiprocessing managers SyncManager Array5333442 Ref: 20e35333442 Ref: library/multiprocessing multiprocessing managers SyncManager Value5333541 Ref: 20e45333541 Ref: library/multiprocessing multiprocessing managers SyncManager dict5333686 Ref: 20e55333686 Ref: library/multiprocessing multiprocessing managers SyncManager list5333867 Ref: 20e65333867 Ref: library/multiprocessing multiprocessing managers Namespace5334273 Ref: 20815334273 Node: Customized managers5335054 Ref: library/multiprocessing customized-managers5335149 Ref: 20e75335149 Node: Using a remote manager5335921 Ref: library/multiprocessing using-a-remote-manager5336016 Ref: 20e85336016 Node: Proxy Objects5338169 Ref: library/multiprocessing multiprocessing-proxy-objects5338267 Ref: 5655338267 Ref: library/multiprocessing proxy-objects5338267 Ref: 20e95338267 Ref: library/multiprocessing multiprocessing managers BaseProxy5341526 Ref: 20d85341526 Ref: library/multiprocessing multiprocessing managers BaseProxy _callmethod5341647 Ref: 20d95341647 Ref: library/multiprocessing multiprocessing managers BaseProxy _getvalue5343228 Ref: 20ea5343228 Ref: library/multiprocessing multiprocessing managers BaseProxy __repr__5343388 Ref: 20eb5343388 Ref: library/multiprocessing multiprocessing managers BaseProxy __str__5343474 Ref: 20ec5343474 Node: Cleanup5343579 Ref: library/multiprocessing cleanup5343636 Ref: 20ed5343636 Node: Process Pools5343925 Ref: library/multiprocessing module-multiprocessing pool5344036 Ref: bb5344036 Ref: library/multiprocessing process-pools5344036 Ref: 20ee5344036 Ref: library/multiprocessing multiprocessing pool Pool5344197 Ref: 87b5344197 Ref: library/multiprocessing multiprocessing pool Pool apply5346805 Ref: 20f15346805 Ref: library/multiprocessing multiprocessing pool Pool apply_async5347176 Ref: 20f25347176 Ref: library/multiprocessing multiprocessing pool Pool map5348028 Ref: a295348028 Ref: library/multiprocessing multiprocessing pool Pool map_async5348812 Ref: a2a5348812 Ref: library/multiprocessing multiprocessing pool Pool imap5349666 Ref: 20f45349666 Ref: library/multiprocessing multiprocessing pool Pool imap_unordered5350376 Ref: 20f55350376 Ref: library/multiprocessing multiprocessing pool Pool starmap5350702 Ref: a265350702 Ref: library/multiprocessing multiprocessing pool Pool starmap_async5351054 Ref: a275351054 Ref: library/multiprocessing multiprocessing pool Pool close5351405 Ref: 20ef5351405 Ref: library/multiprocessing multiprocessing pool Pool terminate5351592 Ref: 20f05351592 Ref: library/multiprocessing multiprocessing pool Pool join5351826 Ref: 20f65351826 Ref: library/multiprocessing multiprocessing pool AsyncResult5352270 Ref: 20f35352270 Ref: library/multiprocessing multiprocessing pool AsyncResult get5352427 Ref: 20f75352427 Ref: library/multiprocessing multiprocessing pool AsyncResult wait5352792 Ref: 20f85352792 Ref: library/multiprocessing multiprocessing pool AsyncResult ready5352916 Ref: 20f95352916 Ref: library/multiprocessing multiprocessing pool AsyncResult successful5352993 Ref: 20fa5352993 Node: Listeners and Clients5354287 Ref: library/multiprocessing listeners-and-clients5354404 Ref: 20fb5354404 Ref: library/multiprocessing module-multiprocessing connection5354404 Ref: b85354404 Ref: library/multiprocessing multiprocessing-listeners-clients5354404 Ref: 20b95354404 Ref: library/multiprocessing multiprocessing connection deliver_challenge5354940 Ref: 20fc5354940 Ref: library/multiprocessing multiprocessing connection answer_challenge5355346 Ref: 20fd5355346 Ref: library/multiprocessing multiprocessing connection Client5355660 Ref: 20fe5355660 Ref: library/multiprocessing multiprocessing connection Listener5356414 Ref: 21005356414 Ref: library/multiprocessing multiprocessing connection Listener accept5358174 Ref: 21015358174 Ref: library/multiprocessing multiprocessing connection Listener close5358456 Ref: 21025358456 Ref: library/multiprocessing multiprocessing connection Listener address5358756 Ref: 21035358756 Ref: library/multiprocessing multiprocessing connection Listener last_accepted5358852 Ref: 21045358852 Ref: library/multiprocessing multiprocessing connection wait5359268 Ref: a245359268 Node: Address Formats5363308 Ref: library/multiprocessing address-formats5363381 Ref: 21055363381 Ref: library/multiprocessing multiprocessing-address-formats5363381 Ref: 20ff5363381 Node: Authentication keys5364102 Ref: library/multiprocessing authentication-keys5364216 Ref: 21065364216 Ref: library/multiprocessing multiprocessing-auth-keys5364216 Ref: 20935364216 Node: Logging<2>5365400 Ref: library/multiprocessing logging5365525 Ref: 21075365525 Ref: library/multiprocessing multiprocessing get_logger5365793 Ref: 21085365793 Ref: library/multiprocessing multiprocessing log_to_stderr5366305 Ref: 21095366305 Node: The multiprocessing dummy module5367316 Ref: library/multiprocessing module-multiprocessing dummy5367413 Ref: b95367413 Ref: library/multiprocessing the-multiprocessing-dummy-module5367413 Ref: 210a5367413 Ref: library/multiprocessing multiprocessing pool ThreadPool5367938 Ref: 210b5367938 Node: Programming guidelines5369773 Ref: library/multiprocessing multiprocessing-programming5369916 Ref: 20765369916 Ref: library/multiprocessing programming-guidelines5369916 Ref: 210c5369916 Node: All start methods5370164 Ref: library/multiprocessing all-start-methods5370287 Ref: 210d5370287 Ref: All start methods-Footnote-15376383 Ref: All start methods-Footnote-25376425 Ref: All start methods-Footnote-35376467 Node: The spawn and forkserver start methods5376509 Ref: library/multiprocessing the-spawn-and-forkserver-start-methods5376632 Ref: 210e5376632 Node: Examples<10>5378709 Ref: library/multiprocessing examples5378834 Ref: 210f5378834 Ref: library/multiprocessing multiprocessing-examples5378834 Ref: 20a55378834 Node: multiprocessing shared_memory — Provides shared memory for direct access across processes5387745 Ref: library/multiprocessing shared_memory doc5387978 Ref: 21105387978 Ref: library/multiprocessing shared_memory module-multiprocessing shared_memory5387978 Ref: bc5387978 Ref: library/multiprocessing shared_memory multiprocessing-shared-memory-provides-shared-memory-for-direct-access-across-processes5387978 Ref: 21115387978 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory5389544 Ref: 20795389544 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory close5391219 Ref: 21125391219 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory unlink5391575 Ref: 21135391575 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory buf5392355 Ref: 21145392355 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory name5392444 Ref: 21155392444 Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory size5392555 Ref: 21165392555 Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager5395645 Ref: 21175395645 Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager SharedMemory5397060 Ref: 21185397060 Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager ShareableList5397216 Ref: 21195397216 Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList5399062 Ref: 211a5399062 Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList count5400237 Ref: 211b5400237 Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList index5400330 Ref: 211c5400330 Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList format5400490 Ref: 211d5400490 Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList shm5400644 Ref: 211e5400644 Ref: multiprocessing shared_memory — Provides shared memory for direct access across processes-Footnote-15402320 Ref: multiprocessing shared_memory — Provides shared memory for direct access across processes-Footnote-25402409 Node: The concurrent package5402440 Ref: library/concurrent doc5402675 Ref: 211f5402675 Ref: library/concurrent the-concurrent-package5402675 Ref: 21205402675 Node: concurrent futures — Launching parallel tasks5402863 Ref: library/concurrent futures doc5403043 Ref: 21215403043 Ref: library/concurrent futures concurrent-futures-launching-parallel-tasks5403043 Ref: 21225403043 Ref: library/concurrent futures module-concurrent futures5403043 Ref: 225403043 Ref: concurrent futures — Launching parallel tasks-Footnote-15403887 Ref: concurrent futures — Launching parallel tasks-Footnote-25403972 Node: Executor Objects5404058 Ref: library/concurrent futures executor-objects5404185 Ref: 21245404185 Ref: library/concurrent futures concurrent futures Executor5404238 Ref: 21235404238 Ref: library/concurrent futures concurrent futures Executor submit5404437 Ref: 2a35404437 Ref: library/concurrent futures concurrent futures Executor map5404877 Ref: 6be5404877 Ref: library/concurrent futures concurrent futures Executor shutdown5406518 Ref: b2e5406518 Node: ThreadPoolExecutor5408183 Ref: library/concurrent futures threadpoolexecutor5408338 Ref: 21265408338 Ref: library/concurrent futures concurrent futures ThreadPoolExecutor5409406 Ref: 27a5409406 Node: ThreadPoolExecutor Example5411190 Ref: library/concurrent futures id15411271 Ref: 21285411271 Ref: library/concurrent futures threadpoolexecutor-example5411271 Ref: b2f5411271 Node: ProcessPoolExecutor5412470 Ref: library/concurrent futures processpoolexecutor5412623 Ref: 21295412623 Ref: library/concurrent futures concurrent futures ProcessPoolExecutor5413357 Ref: 2a45413357 Node: ProcessPoolExecutor Example5415168 Ref: library/concurrent futures id25415251 Ref: 212b5415251 Ref: library/concurrent futures processpoolexecutor-example5415251 Ref: b305415251 Node: Future Objects5416157 Ref: library/concurrent futures future-objects5416308 Ref: 212c5416308 Ref: library/concurrent futures concurrent futures Future5416517 Ref: b2d5416517 Ref: library/concurrent futures concurrent futures Future cancel5416756 Ref: 212d5416756 Ref: library/concurrent futures concurrent futures Future cancelled5417095 Ref: 212e5417095 Ref: library/concurrent futures concurrent futures Future running5417205 Ref: 212f5417205 Ref: library/concurrent futures concurrent futures Future done5417353 Ref: 21305417353 Ref: library/concurrent futures concurrent futures Future result5417493 Ref: 21315417493 Ref: library/concurrent futures concurrent futures Future exception5418227 Ref: 21325418227 Ref: library/concurrent futures concurrent futures Future add_done_callback5418966 Ref: 21335418966 Ref: library/concurrent futures concurrent futures Future set_running_or_notify_cancel5419862 Ref: 21345419862 Ref: library/concurrent futures concurrent futures Future set_result5420951 Ref: 21375420951 Ref: library/concurrent futures concurrent futures Future set_exception5421407 Ref: 21385421407 Node: Module Functions5421898 Ref: library/concurrent futures module-functions5422047 Ref: 213a5422047 Ref: library/concurrent futures concurrent futures wait5422100 Ref: 21365422100 Ref: library/concurrent futures concurrent futures as_completed5424009 Ref: 21355424009 Ref: Module Functions-Footnote-15425066 Node: Exception classes5425115 Ref: library/concurrent futures exception-classes5425241 Ref: 213b5425241 Ref: library/concurrent futures concurrent futures CancelledError5425296 Ref: 1aa5425296 Ref: library/concurrent futures concurrent futures TimeoutError5425387 Ref: 21255425387 Ref: library/concurrent futures concurrent futures BrokenExecutor5425499 Ref: 213c5425499 Ref: library/concurrent futures concurrent futures InvalidStateError5425755 Ref: 21395425755 Ref: library/concurrent futures concurrent futures thread BrokenThreadPool5425937 Ref: 21275425937 Ref: library/concurrent futures concurrent futures process BrokenProcessPool5426189 Ref: 212a5426189 Node: subprocess — Subprocess management5426549 Ref: library/subprocess doc5426732 Ref: 213d5426732 Ref: library/subprocess module-subprocess5426732 Ref: f95426732 Ref: library/subprocess subprocess-subprocess-management5426732 Ref: 213e5426732 Ref: subprocess — Subprocess management-Footnote-15427673 Ref: subprocess — Subprocess management-Footnote-25427742 Node: Using the subprocess Module5427791 Ref: library/subprocess using-the-subprocess-module5427923 Ref: 213f5427923 Ref: library/subprocess subprocess run5428391 Ref: 3ed5428391 Ref: library/subprocess subprocess CompletedProcess5432175 Ref: 7605432175 Ref: library/subprocess subprocess CompletedProcess args5432308 Ref: 21445432308 Ref: library/subprocess subprocess CompletedProcess returncode5432430 Ref: 21455432430 Ref: library/subprocess subprocess CompletedProcess stdout5432704 Ref: 21465432704 Ref: library/subprocess subprocess CompletedProcess stderr5433135 Ref: 21475433135 Ref: library/subprocess subprocess CompletedProcess check_returncode5433377 Ref: 21485433377 Ref: library/subprocess subprocess DEVNULL5433541 Ref: aa05433541 Ref: library/subprocess subprocess PIPE5433785 Ref: 3ee5433785 Ref: library/subprocess subprocess STDOUT5434049 Ref: 21495434049 Ref: library/subprocess subprocess SubprocessError5434256 Ref: 214a5434256 Ref: library/subprocess subprocess TimeoutExpired5434385 Ref: 21435434385 Ref: library/subprocess subprocess TimeoutExpired cmd5434544 Ref: 214b5434544 Ref: library/subprocess subprocess TimeoutExpired timeout5434630 Ref: 214c5434630 Ref: library/subprocess subprocess TimeoutExpired output5434690 Ref: 214d5434690 Ref: library/subprocess subprocess TimeoutExpired stdout5434861 Ref: 214e5434861 Ref: library/subprocess subprocess TimeoutExpired stderr5434956 Ref: 214f5434956 Ref: library/subprocess subprocess CalledProcessError5435199 Ref: cb55435199 Ref: library/subprocess subprocess CalledProcessError returncode5435419 Ref: 21515435419 Ref: library/subprocess subprocess CalledProcessError cmd5435587 Ref: 21525435587 Ref: library/subprocess subprocess CalledProcessError output5435673 Ref: 21535435673 Ref: library/subprocess subprocess CalledProcessError stdout5435844 Ref: 21545435844 Ref: library/subprocess subprocess CalledProcessError stderr5435939 Ref: 21555435939 Node: Frequently Used Arguments5436247 Ref: library/subprocess frequently-used-arguments5436362 Ref: 21415436362 Ref: library/subprocess id15436362 Ref: 21565436362 Node: Popen Constructor5440531 Ref: library/subprocess popen-constructor5440668 Ref: 215b5440668 Ref: library/subprocess subprocess Popen5440963 Ref: 2b95440963 Ref: Popen Constructor-Footnote-15454778 Node: Exceptions<7>5454838 Ref: library/subprocess exceptions5454941 Ref: 216b5454941 Node: Security Considerations5455934 Ref: library/subprocess security-considerations5456088 Ref: 215a5456088 Ref: Security Considerations-Footnote-15456816 Node: Popen Objects5456886 Ref: library/subprocess popen-objects5457034 Ref: 216c5457034 Ref: library/subprocess subprocess Popen poll5457151 Ref: 216d5457151 Ref: library/subprocess subprocess Popen wait5457311 Ref: 5925457311 Ref: library/subprocess subprocess Popen communicate5458240 Ref: 21425458240 Ref: library/subprocess subprocess Popen send_signal5459991 Ref: 216e5459991 Ref: library/subprocess subprocess Popen terminate5460333 Ref: 216f5460333 Ref: library/subprocess subprocess Popen kill5460539 Ref: 21705460539 Ref: library/subprocess subprocess Popen args5460773 Ref: 21715460773 Ref: library/subprocess subprocess Popen stdin5460956 Ref: 21575460956 Ref: library/subprocess subprocess Popen stdout5461387 Ref: 21585461387 Ref: library/subprocess subprocess Popen stderr5461890 Ref: 21595461890 Ref: library/subprocess subprocess Popen pid5462655 Ref: 21725462655 Ref: library/subprocess subprocess Popen returncode5462837 Ref: 216a5462837 Node: Windows Popen Helpers5463188 Ref: library/subprocess windows-popen-helpers5463333 Ref: 21735463333 Ref: library/subprocess subprocess STARTUPINFO5463487 Ref: 215d5463487 Ref: library/subprocess subprocess STARTUPINFO dwFlags5463906 Ref: 21745463906 Ref: library/subprocess subprocess STARTUPINFO hStdInput5464220 Ref: 21755464220 Ref: library/subprocess subprocess STARTUPINFO hStdOutput5464542 Ref: 21775464542 Ref: library/subprocess subprocess STARTUPINFO hStdError5464853 Ref: 21785464853 Ref: library/subprocess subprocess STARTUPINFO wShowWindow5465161 Ref: 21795465161 Ref: library/subprocess subprocess STARTUPINFO lpAttributeList5465653 Ref: 49a5465653 Ref: Windows Popen Helpers-Footnote-15466906 Ref: Windows Popen Helpers-Footnote-25466978 Ref: Windows Popen Helpers-Footnote-35467050 Node: Windows Constants5467139 Ref: library/subprocess windows-constants5467214 Ref: 217c5467214 Ref: library/subprocess subprocess STD_INPUT_HANDLE5467336 Ref: 217d5467336 Ref: library/subprocess subprocess STD_OUTPUT_HANDLE5467473 Ref: 217e5467473 Ref: library/subprocess subprocess STD_ERROR_HANDLE5467621 Ref: 217f5467621 Ref: library/subprocess subprocess SW_HIDE5467767 Ref: 217b5467767 Ref: library/subprocess subprocess STARTF_USESTDHANDLES5467856 Ref: 21765467856 Ref: library/subprocess subprocess STARTF_USESHOWWINDOW5468087 Ref: 217a5468087 Ref: library/subprocess subprocess CREATE_NEW_CONSOLE5468240 Ref: 215e5468240 Ref: library/subprocess subprocess CREATE_NEW_PROCESS_GROUP5468387 Ref: 215f5468387 Ref: library/subprocess subprocess ABOVE_NORMAL_PRIORITY_CLASS5468709 Ref: 21605468709 Ref: library/subprocess subprocess BELOW_NORMAL_PRIORITY_CLASS5468913 Ref: 21615468913 Ref: library/subprocess subprocess HIGH_PRIORITY_CLASS5469116 Ref: 21625469116 Ref: library/subprocess subprocess IDLE_PRIORITY_CLASS5469302 Ref: 21635469302 Ref: library/subprocess subprocess NORMAL_PRIORITY_CLASS5469498 Ref: 21645469498 Ref: library/subprocess subprocess REALTIME_PRIORITY_CLASS5469700 Ref: 21655469700 Ref: library/subprocess subprocess CREATE_NO_WINDOW5470234 Ref: 21665470234 Ref: library/subprocess subprocess DETACHED_PROCESS5470416 Ref: 21675470416 Ref: library/subprocess subprocess CREATE_DEFAULT_ERROR_MODE5470670 Ref: 21685470670 Ref: library/subprocess subprocess CREATE_BREAKAWAY_FROM_JOB5471070 Ref: 21695471070 Node: Older high-level API5471267 Ref: library/subprocess call-function-trio5471451 Ref: 21405471451 Ref: library/subprocess older-high-level-api5471451 Ref: 21805471451 Ref: library/subprocess subprocess call5471699 Ref: 3ef5471699 Ref: library/subprocess subprocess check_call5472753 Ref: 21505472753 Ref: library/subprocess subprocess check_output5473964 Ref: 8db5473964 Node: Replacing Older Functions with the subprocess Module5476195 Ref: library/subprocess replacing-older-functions-with-the-subprocess-module5476391 Ref: 21815476391 Ref: library/subprocess subprocess-replacements5476391 Ref: aea5476391 Node: Replacing /bin/sh shell command substitution5477558 Ref: library/subprocess replacing-bin-sh-shell-command-substitution5477724 Ref: 21825477724 Node: Replacing shell pipeline5477929 Ref: library/subprocess replacing-shell-pipeline5478123 Ref: 21835478123 Node: Replacing os system5478772 Ref: library/subprocess replacing-os-system5478951 Ref: 21845478951 Node: Replacing the os spawn family5479586 Ref: library/subprocess replacing-the-os-spawn-family5479779 Ref: 21855479779 Node: Replacing os popen os popen2 os popen35480410 Ref: library/subprocess replacing-os-popen-os-popen2-os-popen35480626 Ref: 21865480626 Node: Replacing functions from the popen2 module5481921 Ref: library/subprocess replacing-functions-from-the-popen2-module5482099 Ref: 21875482099 Node: Legacy Shell Invocation Functions5483413 Ref: library/subprocess legacy-shell-invocation-functions5483594 Ref: 21885483594 Ref: library/subprocess subprocess getstatusoutput5483958 Ref: 8dc5483958 Ref: library/subprocess subprocess getoutput5485136 Ref: 21895485136 Node: Notes5485582 Ref: library/subprocess notes5485702 Ref: 218a5485702 Node: Converting an argument sequence to a string on Windows5485804 Ref: library/subprocess converting-an-argument-sequence-to-a-string-on-windows5485900 Ref: 218b5485900 Ref: library/subprocess converting-argument-sequence5485900 Ref: 215c5485900 Node: sched — Event scheduler5487060 Ref: library/sched doc5487232 Ref: 218c5487232 Ref: library/sched module-sched5487232 Ref: e35487232 Ref: library/sched sched-event-scheduler5487232 Ref: 218d5487232 Ref: library/sched sched scheduler5487502 Ref: a6e5487502 Ref: sched — Event scheduler-Footnote-15489162 Node: Scheduler Objects5489226 Ref: library/sched id15489305 Ref: 218e5489305 Ref: library/sched scheduler-objects5489305 Ref: 218f5489305 Ref: library/sched sched scheduler enterabs5489436 Ref: a705489436 Ref: library/sched sched scheduler enter5490320 Ref: a6f5490320 Ref: library/sched sched scheduler cancel5490729 Ref: 21905490729 Ref: library/sched sched scheduler empty5490916 Ref: 21915490916 Ref: library/sched sched scheduler run5491001 Ref: a6d5491001 Ref: library/sched sched scheduler queue5492053 Ref: 21925492053 Node: queue — A synchronized queue class5492312 Ref: library/queue doc5492481 Ref: 21935492481 Ref: library/queue module-queue5492481 Ref: da5492481 Ref: library/queue queue-a-synchronized-queue-class5492481 Ref: 21945492481 Ref: library/queue queue Queue5493804 Ref: d185493804 Ref: library/queue queue LifoQueue5494168 Ref: 21955494168 Ref: library/queue queue PriorityQueue5494536 Ref: 21965494536 Ref: library/queue queue SimpleQueue5495531 Ref: 3c65495531 Ref: library/queue queue Empty5495705 Ref: 20a05495705 Ref: library/queue queue Full5495890 Ref: 20a15495890 Ref: queue — A synchronized queue class-Footnote-15496161 Node: Queue Objects5496225 Ref: library/queue queue-objects5496339 Ref: 219b5496339 Ref: library/queue queueobjects5496339 Ref: 219c5496339 Ref: library/queue queue Queue qsize5496518 Ref: 219d5496518 Ref: library/queue queue Queue empty5496747 Ref: 219e5496747 Ref: library/queue queue Queue full5497076 Ref: 219f5497076 Ref: library/queue queue Queue put5497401 Ref: 21995497401 Ref: library/queue queue Queue put_nowait5497993 Ref: 219a5497993 Ref: library/queue queue Queue get5498074 Ref: 21975498074 Ref: library/queue queue Queue get_nowait5498978 Ref: 21985498978 Ref: library/queue queue Queue task_done5499171 Ref: 209c5499171 Ref: library/queue queue Queue join5499817 Ref: 209d5499817 Node: SimpleQueue Objects5500866 Ref: library/queue simplequeue-objects5500980 Ref: 21a05500980 Ref: library/queue queue SimpleQueue qsize5501116 Ref: 21a15501116 Ref: library/queue queue SimpleQueue empty5501282 Ref: 21a25501282 Ref: library/queue queue SimpleQueue put5501499 Ref: 21a35501499 Ref: library/queue queue SimpleQueue put_nowait5502264 Ref: 21a45502264 Ref: library/queue queue SimpleQueue get5502413 Ref: 21a55502413 Ref: library/queue queue SimpleQueue get_nowait5502995 Ref: 21a65502995 Node: contextvars — Context Variables5503443 Ref: library/contextvars doc5503622 Ref: 21a75503622 Ref: library/contextvars contextvars-context-variables5503622 Ref: 21a85503622 Ref: library/contextvars module-contextvars5503622 Ref: 255503622 Ref: contextvars — Context Variables-Footnote-15504479 Node: Context Variables5504528 Ref: library/contextvars context-variables5504649 Ref: 21ac5504649 Ref: library/contextvars contextvars ContextVar5504704 Ref: 21a95504704 Ref: library/contextvars contextvars ContextVar name5505411 Ref: 21ae5505411 Ref: library/contextvars contextvars ContextVar get5505538 Ref: 21ad5505538 Ref: library/contextvars contextvars ContextVar set5506025 Ref: 21af5506025 Ref: library/contextvars contextvars ContextVar reset5506421 Ref: 21b15506421 Ref: library/contextvars contextvars contextvars Token5506942 Ref: 21b05506942 Ref: library/contextvars contextvars contextvars Token Token var5507216 Ref: 21b25507216 Ref: library/contextvars contextvars contextvars Token Token old_value5507360 Ref: 21b35507360 Ref: library/contextvars contextvars contextvars Token Token MISSING5507651 Ref: 21b45507651 Node: Manual Context Management5507744 Ref: library/contextvars manual-context-management5507889 Ref: 21b55507889 Ref: library/contextvars contextvars copy_context5507960 Ref: 21aa5507960 Ref: library/contextvars contextvars Context5508436 Ref: 21ab5508436 Ref: library/contextvars contextvars Context run5508774 Ref: 21b65508774 Ref: library/contextvars contextvars Context copy5510201 Ref: 21b75510201 Ref: library/contextvars contextvars Context get5510644 Ref: 21b85510644 Ref: library/contextvars contextvars Context keys5511086 Ref: 21b95511086 Ref: library/contextvars contextvars Context values5511177 Ref: 21ba5511177 Ref: library/contextvars contextvars Context items5511280 Ref: 21bb5511280 Node: asyncio support5511419 Ref: library/contextvars asyncio-support5511538 Ref: 21bc5511538 Node: _thread — Low-level threading API5513113 Ref: library/_thread doc5513316 Ref: 21bd5513316 Ref: library/_thread module-_thread5513316 Ref: 35513316 Ref: library/_thread thread-low-level-threading-api5513316 Ref: 21be5513316 Ref: library/_thread _thread error5514033 Ref: 21bf5514033 Ref: library/_thread _thread LockType5514201 Ref: 21c05514201 Ref: library/_thread _thread start_new_thread5514269 Ref: 21c15514269 Ref: library/_thread _thread interrupt_main5515161 Ref: 21c25515161 Ref: library/_thread _thread exit5515544 Ref: 21c65515544 Ref: library/_thread _thread allocate_lock5515693 Ref: 21c75515693 Ref: library/_thread _thread get_ident5515841 Ref: 21c85515841 Ref: library/_thread _thread get_native_id5516207 Ref: 21c95516207 Ref: library/_thread _thread stack_size5516665 Ref: 21ca5516665 Ref: library/_thread _thread TIMEOUT_MAX5517907 Ref: 21cb5517907 Ref: library/_thread _thread lock acquire5518187 Ref: 21cc5518187 Ref: library/_thread _thread lock release5519270 Ref: 21cd5519270 Ref: library/_thread _thread lock locked5519412 Ref: 21ce5519412 Node: _dummy_thread — Drop-in replacement for the _thread module5520807 Ref: library/_dummy_thread doc5521041 Ref: 21cf5521041 Ref: library/_dummy_thread dummy-thread-drop-in-replacement-for-the-thread-module5521041 Ref: 21d05521041 Ref: library/_dummy_thread module-_dummy_thread5521041 Ref: 25521041 Ref: _dummy_thread — Drop-in replacement for the _thread module-Footnote-15521838 Node: dummy_threading — Drop-in replacement for the threading module5521910 Ref: library/dummy_threading doc5522100 Ref: 21d15522100 Ref: library/dummy_threading dummy-threading-drop-in-replacement-for-the-threading-module5522100 Ref: 21d25522100 Ref: library/dummy_threading module-dummy_threading5522100 Ref: 685522100 Ref: dummy_threading — Drop-in replacement for the threading module-Footnote-15522879 Node: Networking and Interprocess Communication5522953 Ref: library/ipc doc5523118 Ref: 21d35523118 Ref: library/ipc ipc5523118 Ref: 21d45523118 Ref: library/ipc networking-and-interprocess-communication5523118 Ref: 21d55523118 Node: asyncio — Asynchronous I/O5524022 Ref: library/asyncio doc5524178 Ref: 21d65524178 Ref: library/asyncio asyncio-asynchronous-i-o5524178 Ref: 21d75524178 Ref: library/asyncio module-asyncio5524178 Ref: a5524178 Node: Coroutines and Tasks5525982 Ref: library/asyncio-task doc5526083 Ref: 21e15526083 Ref: library/asyncio-task coroutines-and-tasks5526083 Ref: 21e25526083 Node: Coroutines<3>5526541 Ref: library/asyncio-task coroutine5526630 Ref: 21d85526630 Ref: library/asyncio-task coroutines5526630 Ref: 21e35526630 Node: Awaitables5529055 Ref: library/asyncio-task asyncio-awaitables5529179 Ref: 21e45529179 Ref: library/asyncio-task awaitables5529179 Ref: 21e55529179 Node: Running an asyncio Program5531816 Ref: library/asyncio-task running-an-asyncio-program5531941 Ref: 21e85531941 Ref: library/asyncio-task asyncio run5532014 Ref: 1a55532014 Ref: Running an asyncio Program-Footnote-15532958 Node: Creating Tasks5533032 Ref: library/asyncio-task creating-tasks5533155 Ref: 21e95533155 Ref: library/asyncio-task asyncio create_task5533204 Ref: 1ae5533204 Node: Sleeping5534184 Ref: library/asyncio-task sleeping5534307 Ref: 21ea5534307 Ref: library/asyncio-task asyncio sleep5534344 Ref: 2855534344 Ref: library/asyncio-task asyncio-example-sleep5534730 Ref: 21eb5534730 Node: Running Tasks Concurrently5535235 Ref: library/asyncio-task running-tasks-concurrently5535371 Ref: 21ec5535371 Ref: library/asyncio-task asyncio gather5535444 Ref: 2865535444 Ref: library/asyncio-task asyncio-example-gather5536836 Ref: 21ed5536836 Node: Shielding From Cancellation5538492 Ref: library/asyncio-task shielding-from-cancellation5538628 Ref: 21ee5538628 Ref: library/asyncio-task asyncio shield5538703 Ref: 2875538703 Node: Timeouts5539886 Ref: library/asyncio-task timeouts5540014 Ref: 21f05540014 Ref: library/asyncio-task asyncio wait_for5540051 Ref: 2885540051 Ref: library/asyncio-task asyncio-example-waitfor5540904 Ref: 21f25540904 Node: Waiting Primitives5541586 Ref: library/asyncio-task waiting-primitives5541716 Ref: 21f35541716 Ref: library/asyncio-task asyncio wait5541775 Ref: 2895541775 Ref: library/asyncio-task asyncio-example-wait-coroutine5544069 Ref: 21f45544069 Ref: library/asyncio-task asyncio as_completed5544974 Ref: 28a5544974 Node: Scheduling From Other Threads5545609 Ref: library/asyncio-task scheduling-from-other-threads5545744 Ref: 21f55545744 Ref: library/asyncio-task asyncio run_coroutine_threadsafe5545825 Ref: 51a5545825 Node: Introspection5547258 Ref: library/asyncio-task introspection5547386 Ref: 21f75547386 Ref: library/asyncio-task asyncio current_task5547435 Ref: 3505547435 Ref: library/asyncio-task asyncio all_tasks5547712 Ref: 3515547712 Node: Task Object5547970 Ref: library/asyncio-task task-object5548095 Ref: 21f85548095 Ref: library/asyncio-task asyncio Task5548140 Ref: 1ad5548140 Ref: library/asyncio-task asyncio Task cancel5550156 Ref: 21ef5550156 Ref: library/asyncio-task asyncio-example-task-cancel5550865 Ref: 21fd5550865 Ref: library/asyncio-task asyncio Task cancelled5552122 Ref: 21f95552122 Ref: library/asyncio-task asyncio Task done5552432 Ref: 21fe5552432 Ref: library/asyncio-task asyncio Task result5552648 Ref: 21ff5552648 Ref: library/asyncio-task asyncio Task exception5553136 Ref: 22015553136 Ref: library/asyncio-task asyncio Task add_done_callback5553623 Ref: 22025553623 Ref: library/asyncio-task asyncio Task remove_done_callback5553938 Ref: 22035553938 Ref: library/asyncio-task asyncio Task get_stack5554236 Ref: 22055554236 Ref: library/asyncio-task asyncio Task print_stack5555232 Ref: 22065555232 Ref: library/asyncio-task asyncio Task get_coro5555724 Ref: 1ac5555724 Ref: library/asyncio-task asyncio Task get_name5555856 Ref: 1b15555856 Ref: library/asyncio-task asyncio Task set_name5556128 Ref: 1b05556128 Ref: library/asyncio-task asyncio Task all_tasks5556462 Ref: 3535556462 Ref: library/asyncio-task asyncio Task current_task5556950 Ref: 3525556950 Node: Generator-based Coroutines5557376 Ref: library/asyncio-task asyncio-generator-based-coro5557479 Ref: 21e65557479 Ref: library/asyncio-task generator-based-coroutines5557479 Ref: 22075557479 Ref: library/asyncio-task asyncio coroutine5557950 Ref: 2825557950 Ref: library/asyncio-task asyncio iscoroutine5558516 Ref: 22085558516 Ref: library/asyncio-task asyncio iscoroutinefunction5558762 Ref: 22095558762 Node: Streams5559079 Ref: library/asyncio-stream doc5559215 Ref: 220a5559215 Ref: library/asyncio-stream asyncio-streams5559215 Ref: 21d95559215 Ref: library/asyncio-stream streams5559215 Ref: 220b5559215 Ref: library/asyncio-stream asyncio-example-stream5559552 Ref: 220c5559552 Ref: library/asyncio-stream asyncio open_connection5560298 Ref: 3635560298 Ref: library/asyncio-stream asyncio start_server5561225 Ref: 3645561225 Ref: library/asyncio-stream asyncio open_unix_connection5562524 Ref: 22105562524 Ref: library/asyncio-stream asyncio start_unix_server5563165 Ref: 22125563165 Ref: Streams-Footnote-15563891 Node: StreamReader5563965 Ref: library/asyncio-stream streamreader5564042 Ref: 22135564042 Ref: library/asyncio-stream asyncio StreamReader5564089 Ref: 220e5564089 Ref: library/asyncio-stream asyncio StreamReader read5564372 Ref: 22145564372 Ref: library/asyncio-stream asyncio StreamReader readline5564653 Ref: 22155564653 Ref: library/asyncio-stream asyncio StreamReader readexactly5565009 Ref: 51f5565009 Ref: library/asyncio-stream asyncio StreamReader readuntil5565305 Ref: 51e5565305 Ref: library/asyncio-stream asyncio StreamReader at_eof5566154 Ref: 22195566154 Node: StreamWriter5566277 Ref: library/asyncio-stream streamwriter5566375 Ref: 221a5566375 Ref: library/asyncio-stream asyncio StreamWriter5566422 Ref: 220f5566422 Ref: library/asyncio-stream asyncio StreamWriter write5566704 Ref: 221b5566704 Ref: library/asyncio-stream asyncio StreamWriter writelines5567074 Ref: 221c5567074 Ref: library/asyncio-stream asyncio StreamWriter close5567467 Ref: 221d5567467 Ref: library/asyncio-stream asyncio StreamWriter can_write_eof5567724 Ref: 221e5567724 Ref: library/asyncio-stream asyncio StreamWriter write_eof5567895 Ref: 221f5567895 Ref: library/asyncio-stream asyncio StreamWriter transport5568023 Ref: 22205568023 Ref: library/asyncio-stream asyncio StreamWriter get_extra_info5568106 Ref: 22215568106 Ref: library/asyncio-stream asyncio StreamWriter drain5568280 Ref: 22225568280 Ref: library/asyncio-stream asyncio StreamWriter is_closing5568873 Ref: 3575568873 Ref: library/asyncio-stream asyncio StreamWriter wait_closed5569034 Ref: 3565569034 Node: Examples<11>5569268 Ref: library/asyncio-stream examples5569345 Ref: 220d5569345 Node: TCP echo client using streams5569542 Ref: library/asyncio-stream asyncio-tcp-echo-client-streams5569658 Ref: 22235569658 Ref: library/asyncio-stream tcp-echo-client-using-streams5569658 Ref: 22245569658 Node: TCP echo server using streams5570380 Ref: library/asyncio-stream asyncio-tcp-echo-server-streams5570521 Ref: 22265570521 Ref: library/asyncio-stream tcp-echo-server-using-streams5570521 Ref: 22275570521 Node: Get HTTP headers5571495 Ref: library/asyncio-stream get-http-headers5571661 Ref: 22295571661 Node: Register an open socket to wait for data using streams5572896 Ref: library/asyncio-stream asyncio-example-create-connection-streams5573024 Ref: 222a5573024 Ref: library/asyncio-stream register-an-open-socket-to-wait-for-data-using-streams5573024 Ref: 222b5573024 Node: Synchronization Primitives5574413 Ref: library/asyncio-sync doc5574541 Ref: 222f5574541 Ref: library/asyncio-sync asyncio-sync5574541 Ref: 21dc5574541 Ref: library/asyncio-sync synchronization-primitives5574541 Ref: 22305574541 Ref: Synchronization Primitives-Footnote-15575582 Node: Lock5575654 Ref: library/asyncio-sync lock5575735 Ref: 22315575735 Ref: library/asyncio-sync asyncio Lock5575766 Ref: 28b5575766 Ref: library/asyncio-sync asyncio Lock acquire5576478 Ref: 22325576478 Ref: library/asyncio-sync asyncio Lock release5576972 Ref: 22335576972 Ref: library/asyncio-sync asyncio Lock locked5577189 Ref: 22345577189 Node: Event5577271 Ref: library/asyncio-sync event5577370 Ref: 22355577370 Ref: library/asyncio-sync asyncio Event5577403 Ref: 28c5577403 Ref: library/asyncio-sync asyncio-example-sync-event5577982 Ref: 22395577982 Ref: library/asyncio-sync asyncio Event wait5578611 Ref: 22385578611 Ref: library/asyncio-sync asyncio Event set5578821 Ref: 22365578821 Ref: library/asyncio-sync asyncio Event clear5578961 Ref: 22375578961 Ref: library/asyncio-sync asyncio Event is_set5579151 Ref: 223a5579151 Node: Condition5579229 Ref: library/asyncio-sync condition5579333 Ref: 223b5579333 Ref: library/asyncio-sync asyncio Condition5579374 Ref: 28d5579374 Ref: library/asyncio-sync asyncio Condition acquire5580655 Ref: 223c5580655 Ref: library/asyncio-sync asyncio Condition notify5580858 Ref: 223d5580858 Ref: library/asyncio-sync asyncio Condition locked5581217 Ref: 223e5581217 Ref: library/asyncio-sync asyncio Condition notify_all5581310 Ref: 223f5581310 Ref: library/asyncio-sync asyncio Condition release5581688 Ref: 22405581688 Ref: library/asyncio-sync asyncio Condition wait5581850 Ref: 22415581850 Ref: library/asyncio-sync asyncio Condition wait_for5582320 Ref: 22425582320 Node: Semaphore5582574 Ref: library/asyncio-sync semaphore5582689 Ref: 22435582689 Ref: library/asyncio-sync asyncio Semaphore5582730 Ref: 28e5582730 Ref: library/asyncio-sync asyncio Semaphore acquire5583891 Ref: 22445583891 Ref: library/asyncio-sync asyncio Semaphore locked5584179 Ref: 22465584179 Ref: library/asyncio-sync asyncio Semaphore release5584283 Ref: 22455584283 Node: BoundedSemaphore5584597 Ref: library/asyncio-sync boundedsemaphore5584694 Ref: 22475584694 Ref: library/asyncio-sync asyncio BoundedSemaphore5584749 Ref: 28f5584749 Node: Subprocesses5585460 Ref: library/asyncio-subprocess doc5585587 Ref: 22485585587 Ref: library/asyncio-subprocess asyncio-subprocess5585587 Ref: 21da5585587 Ref: library/asyncio-subprocess subprocesses5585587 Ref: 22495585587 Ref: library/asyncio-subprocess asyncio-example-subprocess-shell5585875 Ref: 224a5585875 Ref: Subprocesses-Footnote-15587171 Ref: Subprocesses-Footnote-25587249 Node: Creating Subprocesses5587332 Ref: library/asyncio-subprocess creating-subprocesses5587423 Ref: 224c5587423 Ref: library/asyncio-subprocess asyncio create_subprocess_exec5587488 Ref: 2915587488 Ref: library/asyncio-subprocess asyncio create_subprocess_shell5588145 Ref: 2925588145 Ref: Creating Subprocesses-Footnote-15589748 Node: Constants<7>5589818 Ref: library/asyncio-subprocess constants5589947 Ref: 22545589947 Ref: library/asyncio-subprocess asyncio asyncio subprocess PIPE5589988 Ref: 22555589988 Ref: library/asyncio-subprocess asyncio asyncio subprocess STDOUT5590434 Ref: 22595590434 Ref: library/asyncio-subprocess asyncio asyncio subprocess DEVNULL5590620 Ref: 225a5590620 Node: Interacting with Subprocesses5590901 Ref: library/asyncio-subprocess interacting-with-subprocesses5591000 Ref: 225b5591000 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process5591331 Ref: 224d5591331 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process wait5592309 Ref: 225d5592309 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process communicate5592818 Ref: 225c5592818 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process send_signal5594054 Ref: 22605594054 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process terminate5594446 Ref: 22615594446 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process kill5594735 Ref: 22635594735 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process stdin5594965 Ref: 22565594965 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process stdout5595127 Ref: 22575595127 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process stderr5595292 Ref: 22585595292 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process pid5595795 Ref: 22645595795 Ref: library/asyncio-subprocess asyncio asyncio subprocess Process returncode5596034 Ref: 225f5596034 Node: Subprocess and Threads5596392 Ref: library/asyncio-subprocess asyncio-subprocess-threads5596501 Ref: 225e5596501 Ref: library/asyncio-subprocess subprocess-and-threads5596501 Ref: 22655596501 Node: Examples<12>5597371 Ref: library/asyncio-subprocess examples5597480 Ref: 224b5597480 Ref: library/asyncio-subprocess asyncio-example-create-subprocess-exec5597664 Ref: 22695597664 Node: Queues5598467 Ref: library/asyncio-queue doc5598581 Ref: 226b5598581 Ref: library/asyncio-queue asyncio-queues5598581 Ref: 21db5598581 Ref: library/asyncio-queue queues5598581 Ref: 226c5598581 Ref: Queues-Footnote-15599272 Node: Queue5599345 Ref: library/asyncio-queue queue5599416 Ref: 226e5599416 Ref: library/asyncio-queue asyncio Queue5599449 Ref: 2905599449 Ref: library/asyncio-queue asyncio Queue maxsize5600107 Ref: 22715600107 Ref: library/asyncio-queue asyncio Queue empty5600185 Ref: 22725600185 Ref: library/asyncio-queue asyncio Queue full5600287 Ref: 22735600287 Ref: library/asyncio-queue asyncio Queue get5600543 Ref: 226f5600543 Ref: library/asyncio-queue asyncio Queue get_nowait5600694 Ref: 22745600694 Ref: library/asyncio-queue asyncio Queue join5600830 Ref: 69f5600830 Ref: library/asyncio-queue asyncio Queue put5601328 Ref: 22765601328 Ref: library/asyncio-queue asyncio Queue put_nowait5601499 Ref: 22775601499 Ref: library/asyncio-queue asyncio Queue qsize5601683 Ref: 22705601683 Ref: library/asyncio-queue asyncio Queue task_done5601762 Ref: 6a05601762 Node: Priority Queue5602445 Ref: library/asyncio-queue priority-queue5602535 Ref: 22795602535 Ref: library/asyncio-queue asyncio PriorityQueue5602586 Ref: 227a5602586 Node: LIFO Queue5602793 Ref: library/asyncio-queue lifo-queue5602891 Ref: 227b5602891 Ref: library/asyncio-queue asyncio LifoQueue5602934 Ref: 227c5602934 Node: Exceptions<8>5603077 Ref: library/asyncio-queue exceptions5603173 Ref: 227d5603173 Ref: library/asyncio-queue asyncio QueueEmpty5603216 Ref: 22755603216 Ref: library/asyncio-queue asyncio QueueFull5603358 Ref: 22785603358 Node: Examples<13>5603515 Ref: library/asyncio-queue examples5603592 Ref: 226d5603592 Ref: library/asyncio-queue asyncio-example-queue-dist5603631 Ref: 227e5603631 Node: Exceptions<9>5605389 Ref: library/asyncio-exceptions doc5605501 Ref: 227f5605501 Ref: library/asyncio-exceptions asyncio-exceptions5605501 Ref: 22805605501 Ref: library/asyncio-exceptions exceptions5605501 Ref: 22815605501 Ref: library/asyncio-exceptions asyncio TimeoutError5605657 Ref: 21f15605657 Ref: library/asyncio-exceptions asyncio CancelledError5605860 Ref: 1a75605860 Ref: library/asyncio-exceptions asyncio InvalidStateError5606215 Ref: 22005606215 Ref: library/asyncio-exceptions asyncio SendfileNotAvailableError5606454 Ref: 22825606454 Ref: library/asyncio-exceptions asyncio IncompleteReadError5606639 Ref: 22165606639 Ref: library/asyncio-exceptions asyncio IncompleteReadError expected5606854 Ref: 22835606854 Ref: library/asyncio-exceptions asyncio IncompleteReadError partial5606949 Ref: 22175606949 Ref: library/asyncio-exceptions asyncio LimitOverrunError5607072 Ref: 22185607072 Ref: library/asyncio-exceptions asyncio LimitOverrunError consumed5607234 Ref: 22845607234 Ref: Exceptions<9>-Footnote-15607353 Node: Event Loop5607431 Ref: library/asyncio-eventloop doc5607544 Ref: 22855607544 Ref: library/asyncio-eventloop event-loop5607544 Ref: 22865607544 Ref: library/asyncio-eventloop asyncio get_running_loop5608374 Ref: 3545608374 Ref: library/asyncio-eventloop asyncio get_event_loop5608659 Ref: 3555608659 Ref: library/asyncio-eventloop asyncio set_event_loop5609379 Ref: 22875609379 Ref: library/asyncio-eventloop asyncio new_event_loop5609492 Ref: 22885609492 Ref: Event Loop-Footnote-15610761 Ref: Event Loop-Footnote-25610834 Node: Event Loop Methods5610913 Ref: library/asyncio-eventloop asyncio-event-loop5611003 Ref: 6445611003 Ref: library/asyncio-eventloop event-loop-methods5611003 Ref: 228a5611003 Node: Running and stopping the loop5611586 Ref: library/asyncio-eventloop running-and-stopping-the-loop5611699 Ref: 22915611699 Ref: library/asyncio-eventloop asyncio loop run_until_complete5611780 Ref: 5185611780 Ref: library/asyncio-eventloop asyncio loop run_forever5612096 Ref: 22925612096 Ref: library/asyncio-eventloop asyncio loop stop5612816 Ref: 5205612816 Ref: library/asyncio-eventloop asyncio loop is_running5612869 Ref: 22935612869 Ref: library/asyncio-eventloop asyncio loop is_closed5612965 Ref: 69b5612965 Ref: library/asyncio-eventloop asyncio loop close5613050 Ref: 22945613050 Ref: library/asyncio-eventloop asyncio loop shutdown_asyncgens5613455 Ref: 5215613455 Node: Scheduling callbacks5614139 Ref: library/asyncio-eventloop scheduling-callbacks5614289 Ref: 22955614289 Ref: library/asyncio-eventloop asyncio loop call_soon5614352 Ref: 3495614352 Ref: library/asyncio-eventloop asyncio loop call_soon_threadsafe5615026 Ref: 34a5615026 Ref: library/asyncio-eventloop asyncio-pass-keywords5615415 Ref: 22975615415 Ref: Scheduling callbacks-Footnote-15615910 Node: Scheduling delayed callbacks5615959 Ref: library/asyncio-eventloop asyncio-delayed-calls5616106 Ref: 22985616106 Ref: library/asyncio-eventloop scheduling-delayed-callbacks5616106 Ref: 22995616106 Ref: library/asyncio-eventloop asyncio loop call_later5616339 Ref: 34b5616339 Ref: library/asyncio-eventloop asyncio loop call_at5617510 Ref: 34c5617510 Ref: library/asyncio-eventloop asyncio loop time5618270 Ref: 229a5618270 Ref: Scheduling delayed callbacks-Footnote-15618705 Ref: Scheduling delayed callbacks-Footnote-25618754 Node: Creating Futures and Tasks5618803 Ref: library/asyncio-eventloop creating-futures-and-tasks5618957 Ref: 229b5618957 Ref: library/asyncio-eventloop asyncio loop create_future5619032 Ref: 51c5619032 Ref: library/asyncio-eventloop asyncio loop create_task5619388 Ref: 1af5619388 Ref: library/asyncio-eventloop asyncio loop set_task_factory5619907 Ref: 69d5619907 Ref: library/asyncio-eventloop asyncio loop get_task_factory5620377 Ref: 69e5620377 Node: Opening network connections5620487 Ref: library/asyncio-eventloop opening-network-connections5620637 Ref: 229c5620637 Ref: library/asyncio-eventloop asyncio loop create_connection5620714 Ref: 1b25620714 Ref: library/asyncio-eventloop asyncio loop create_datagram_endpoint5626532 Ref: 2e75626532 Ref: library/asyncio-eventloop asyncio loop create_unix_connection5629986 Ref: 22115629986 Ref: Opening network connections-Footnote-15630950 Ref: Opening network connections-Footnote-25630999 Node: Creating network servers5631048 Ref: library/asyncio-eventloop creating-network-servers5631190 Ref: 22a65631190 Ref: library/asyncio-eventloop asyncio loop create_server5631261 Ref: 35d5631261 Ref: library/asyncio-eventloop asyncio loop create_unix_server5634906 Ref: 35e5634906 Ref: library/asyncio-eventloop asyncio loop connect_accepted_socket5635764 Ref: 3655635764 Node: Transferring files5636794 Ref: library/asyncio-eventloop transferring-files5636920 Ref: 22a75636920 Ref: library/asyncio-eventloop asyncio loop sendfile5636979 Ref: 22a85636979 Node: TLS Upgrade5638037 Ref: library/asyncio-eventloop tls-upgrade5638164 Ref: 22a95638164 Ref: library/asyncio-eventloop asyncio loop start_tls5638209 Ref: 34e5638209 Node: Watching file descriptors5639433 Ref: library/asyncio-eventloop watching-file-descriptors5639578 Ref: 22aa5639578 Ref: library/asyncio-eventloop asyncio loop add_reader5639651 Ref: 222e5639651 Ref: library/asyncio-eventloop asyncio loop remove_reader5639869 Ref: 22ab5639869 Ref: library/asyncio-eventloop asyncio loop add_writer5639976 Ref: 22ac5639976 Ref: library/asyncio-eventloop asyncio loop remove_writer5640296 Ref: 22ad5640296 Node: Working with socket objects directly5640491 Ref: library/asyncio-eventloop working-with-socket-objects-directly5640628 Ref: 22af5640628 Ref: library/asyncio-eventloop asyncio loop sock_recv5641079 Ref: 49e5641079 Ref: library/asyncio-eventloop asyncio loop sock_recv_into5641548 Ref: 34f5641548 Ref: library/asyncio-eventloop asyncio loop sock_sendall5641855 Ref: 49f5641855 Ref: library/asyncio-eventloop asyncio loop sock_connect5642612 Ref: 6a15642612 Ref: library/asyncio-eventloop asyncio loop sock_accept5643233 Ref: 4a05643233 Ref: library/asyncio-eventloop asyncio loop sock_sendfile5644057 Ref: 3585644057 Node: DNS5645258 Ref: library/asyncio-eventloop dns5645388 Ref: 22b05645388 Ref: library/asyncio-eventloop asyncio loop getaddrinfo5645417 Ref: 4a15645417 Ref: library/asyncio-eventloop asyncio loop getnameinfo5645583 Ref: 4a25645583 Node: Working with pipes5645967 Ref: library/asyncio-eventloop working-with-pipes5646073 Ref: 22b35646073 Ref: library/asyncio-eventloop asyncio loop connect_read_pipe5646132 Ref: 22505646132 Ref: library/asyncio-eventloop asyncio loop connect_write_pipe5646707 Ref: 22515646707 Node: Unix signals5647545 Ref: library/asyncio-eventloop unix-signals5647689 Ref: 22b65647689 Ref: library/asyncio-eventloop asyncio loop add_signal_handler5647736 Ref: 21de5647736 Ref: library/asyncio-eventloop asyncio loop remove_signal_handler5648524 Ref: 22b75648524 Node: Executing code in thread or process pools5648828 Ref: library/asyncio-eventloop executing-code-in-thread-or-process-pools5648972 Ref: 22b85648972 Ref: library/asyncio-eventloop asyncio loop run_in_executor5649077 Ref: 21e75649077 Ref: library/asyncio-eventloop asyncio loop set_default_executor5651221 Ref: 27b5651221 Node: Error Handling API5651705 Ref: library/asyncio-eventloop error-handling-api5651856 Ref: 22b95651856 Ref: library/asyncio-eventloop asyncio loop set_exception_handler5651981 Ref: 22ba5651981 Ref: library/asyncio-eventloop asyncio loop get_exception_handler5652509 Ref: 51d5652509 Ref: library/asyncio-eventloop asyncio loop default_exception_handler5652683 Ref: 22bc5652683 Ref: library/asyncio-eventloop asyncio loop call_exception_handler5653058 Ref: 22bb5653058 Node: Enabling debug mode5653937 Ref: library/asyncio-eventloop enabling-debug-mode5654067 Ref: 22bd5654067 Ref: library/asyncio-eventloop asyncio loop get_debug5654128 Ref: 69a5654128 Ref: library/asyncio-eventloop asyncio loop set_debug5654382 Ref: 6995654382 Node: Running Subprocesses5654651 Ref: library/asyncio-eventloop running-subprocesses5654754 Ref: 22be5654754 Ref: library/asyncio-eventloop asyncio loop subprocess_exec5655214 Ref: 21dd5655214 Ref: library/asyncio-eventloop asyncio loop subprocess_shell5659206 Ref: 224e5659206 Ref: Running Subprocesses-Footnote-15660526 Node: Callback Handles5660596 Ref: library/asyncio-eventloop callback-handles5660709 Ref: 228b5660709 Ref: library/asyncio-eventloop asyncio Handle5660764 Ref: 228c5660764 Ref: library/asyncio-eventloop asyncio Handle cancel5660909 Ref: 22c15660909 Ref: library/asyncio-eventloop asyncio Handle cancelled5661062 Ref: 3665661062 Ref: library/asyncio-eventloop asyncio TimerHandle5661184 Ref: 228d5661184 Ref: library/asyncio-eventloop asyncio TimerHandle when5661380 Ref: 3625661380 Node: Server Objects5661625 Ref: library/asyncio-eventloop server-objects5661746 Ref: 228e5661746 Ref: library/asyncio-eventloop asyncio Server5662014 Ref: 35c5662014 Ref: library/asyncio-eventloop asyncio Server close5662577 Ref: 22c25662577 Ref: library/asyncio-eventloop asyncio Server get_loop5662969 Ref: 35b5662969 Ref: library/asyncio-eventloop asyncio Server start_serving5663098 Ref: 35f5663098 Ref: library/asyncio-eventloop asyncio Server serve_forever5663722 Ref: 3605663722 Ref: library/asyncio-eventloop asyncio Server is_serving5664619 Ref: 3615664619 Ref: library/asyncio-eventloop asyncio Server wait_closed5664755 Ref: 22c35664755 Ref: library/asyncio-eventloop asyncio Server sockets5664863 Ref: 4a35664863 Node: Event Loop Implementations5665179 Ref: library/asyncio-eventloop asyncio-event-loops5665296 Ref: 22c45665296 Ref: library/asyncio-eventloop event-loop-implementations5665296 Ref: 228f5665296 Ref: library/asyncio-eventloop asyncio SelectorEventLoop5665624 Ref: 22665665624 Ref: library/asyncio-eventloop asyncio ProactorEventLoop5666139 Ref: 1ab5666139 Ref: library/asyncio-eventloop asyncio AbstractEventLoop5666377 Ref: 22c55666377 Ref: Event Loop Implementations-Footnote-15666672 Node: Examples<14>5666758 Ref: library/asyncio-eventloop examples5666852 Ref: 22905666852 Node: Hello World with call_soon5667451 Ref: library/asyncio-eventloop asyncio-example-lowlevel-helloworld5667575 Ref: 22c65667575 Ref: library/asyncio-eventloop hello-world-with-call-soon5667575 Ref: 22c75667575 Node: Display the current date with call_later5668349 Ref: library/asyncio-eventloop asyncio-example-call-later5668521 Ref: 22c85668521 Ref: library/asyncio-eventloop display-the-current-date-with-call-later5668521 Ref: 22c95668521 Node: Watch a file descriptor for read events5669513 Ref: library/asyncio-eventloop asyncio-example-watch-fd5669701 Ref: 222d5669701 Ref: library/asyncio-eventloop watch-a-file-descriptor-for-read-events5669701 Ref: 22ca5669701 Node: Set signal handlers for SIGINT and SIGTERM5671021 Ref: library/asyncio-eventloop asyncio-example-unix-signals5671160 Ref: 22cb5671160 Ref: library/asyncio-eventloop set-signal-handlers-for-sigint-and-sigterm5671160 Ref: 22cc5671160 Node: Futures5672075 Ref: library/asyncio-future doc5672199 Ref: 22cd5672199 Ref: library/asyncio-future asyncio-futures5672199 Ref: 21e05672199 Ref: library/asyncio-future futures5672199 Ref: 22ce5672199 Ref: Futures-Footnote-15672566 Ref: Futures-Footnote-25672640 Node: Future Functions5672720 Ref: library/asyncio-future future-functions5672802 Ref: 22cf5672802 Ref: library/asyncio-future asyncio isfuture5672857 Ref: 22d05672857 Ref: library/asyncio-future asyncio ensure_future5673163 Ref: 5175673163 Ref: library/asyncio-future asyncio wrap_future5674104 Ref: 22d15674104 Node: Future Object5674265 Ref: library/asyncio-future future-object5674347 Ref: 22d25674347 Ref: library/asyncio-future asyncio Future5674396 Ref: 4435674396 Ref: library/asyncio-future asyncio Future result5675318 Ref: 22d35675318 Ref: library/asyncio-future asyncio Future set_result5675933 Ref: 21fa5675933 Ref: library/asyncio-future asyncio Future set_exception5676128 Ref: 21fb5676128 Ref: library/asyncio-future asyncio Future done5676331 Ref: 22d45676331 Ref: library/asyncio-future asyncio Future cancelled5676595 Ref: 22d55676595 Ref: library/asyncio-future asyncio Future add_done_callback5676900 Ref: 34d5676900 Ref: library/asyncio-future asyncio Future remove_done_callback5677889 Ref: 22045677889 Ref: library/asyncio-future asyncio Future cancel5678121 Ref: 21fc5678121 Ref: library/asyncio-future asyncio Future exception5678404 Ref: 22d65678404 Ref: library/asyncio-future asyncio Future get_loop5678848 Ref: 35a5678848 Ref: library/asyncio-future asyncio-example-future5678973 Ref: 22d75678973 Ref: Future Object-Footnote-15681010 Node: Transports and Protocols5681059 Ref: library/asyncio-protocol doc5681181 Ref: 22d85681181 Ref: library/asyncio-protocol asyncio-transports-protocols5681181 Ref: 21df5681181 Ref: library/asyncio-protocol transports-and-protocols5681181 Ref: 22d95681181 Node: Transports5683549 Ref: library/asyncio-protocol asyncio-transport5683638 Ref: 22a05683638 Ref: library/asyncio-protocol transports5683638 Ref: 22da5683638 Ref: Transports-Footnote-15684380 Node: Transports Hierarchy5684458 Ref: library/asyncio-protocol transports-hierarchy5684548 Ref: 22e35684548 Ref: library/asyncio-protocol asyncio BaseTransport5684611 Ref: 22dc5684611 Ref: library/asyncio-protocol asyncio WriteTransport5684740 Ref: 22b55684740 Ref: library/asyncio-protocol asyncio ReadTransport5685071 Ref: 22b45685071 Ref: library/asyncio-protocol asyncio Transport5685398 Ref: 22dd5685398 Ref: library/asyncio-protocol asyncio DatagramTransport5686001 Ref: 22de5686001 Ref: library/asyncio-protocol asyncio SubprocessTransport5686244 Ref: 22c05686244 Node: Base Transport5686570 Ref: library/asyncio-protocol base-transport5686689 Ref: 22e45686689 Ref: library/asyncio-protocol asyncio BaseTransport close5686740 Ref: 22e55686740 Ref: library/asyncio-protocol asyncio BaseTransport is_closing5687111 Ref: 51b5687111 Ref: library/asyncio-protocol asyncio BaseTransport get_extra_info5687218 Ref: 2c85687218 Ref: library/asyncio-protocol asyncio BaseTransport set_protocol5689375 Ref: 22ea5689375 Ref: library/asyncio-protocol asyncio BaseTransport get_protocol5689560 Ref: 22eb5689560 Node: Read-only Transports5689638 Ref: library/asyncio-protocol read-only-transports5689758 Ref: 22ec5689758 Ref: library/asyncio-protocol asyncio ReadTransport is_reading5689821 Ref: 3675689821 Ref: library/asyncio-protocol asyncio ReadTransport pause_reading5689952 Ref: 3695689952 Ref: library/asyncio-protocol asyncio ReadTransport resume_reading5690321 Ref: 3685690321 Node: Write-only Transports5690659 Ref: library/asyncio-protocol write-only-transports5690784 Ref: 22ee5690784 Ref: library/asyncio-protocol asyncio WriteTransport abort5690849 Ref: 22ef5690849 Ref: library/asyncio-protocol asyncio WriteTransport can_write_eof5691188 Ref: 22f05691188 Ref: library/asyncio-protocol asyncio WriteTransport get_write_buffer_size5691345 Ref: 22f25691345 Ref: library/asyncio-protocol asyncio WriteTransport get_write_buffer_limits5691472 Ref: 69c5691472 Ref: library/asyncio-protocol asyncio WriteTransport set_write_buffer_limits5691786 Ref: 22f35691786 Ref: library/asyncio-protocol asyncio WriteTransport write5693198 Ref: 22f65693198 Ref: library/asyncio-protocol asyncio WriteTransport writelines5693397 Ref: 22f75693397 Ref: library/asyncio-protocol asyncio WriteTransport write_eof5693681 Ref: 22f15693681 Node: Datagram Transports5693970 Ref: library/asyncio-protocol datagram-transports5694096 Ref: 22f85694096 Ref: library/asyncio-protocol asyncio DatagramTransport sendto5694157 Ref: 22f95694157 Ref: library/asyncio-protocol asyncio DatagramTransport abort5694535 Ref: 22fa5694535 Node: Subprocess Transports5694877 Ref: library/asyncio-protocol asyncio-subprocess-transports5694973 Ref: 22525694973 Ref: library/asyncio-protocol subprocess-transports5694973 Ref: 22fb5694973 Ref: library/asyncio-protocol asyncio SubprocessTransport get_pid5695038 Ref: 22fc5695038 Ref: library/asyncio-protocol asyncio SubprocessTransport get_pipe_transport5695136 Ref: 22fd5695136 Ref: library/asyncio-protocol asyncio SubprocessTransport get_returncode5695882 Ref: 22fe5695882 Ref: library/asyncio-protocol asyncio SubprocessTransport kill5696118 Ref: 22ff5696118 Ref: library/asyncio-protocol asyncio SubprocessTransport send_signal5696379 Ref: 23015696379 Ref: library/asyncio-protocol asyncio SubprocessTransport terminate5696538 Ref: 23005696538 Ref: library/asyncio-protocol asyncio SubprocessTransport close5696838 Ref: 23025696838 Node: Protocols5697064 Ref: library/asyncio-protocol asyncio-protocol5697174 Ref: 229f5697174 Ref: library/asyncio-protocol protocols5697174 Ref: 22db5697174 Ref: Protocols-Footnote-15697967 Node: Base Protocols5698044 Ref: library/asyncio-protocol base-protocols5698126 Ref: 23035698126 Ref: library/asyncio-protocol asyncio BaseProtocol5698177 Ref: 22df5698177 Ref: library/asyncio-protocol asyncio Protocol5698269 Ref: 22e05698269 Ref: library/asyncio-protocol asyncio BufferedProtocol5698402 Ref: 2c95698402 Ref: library/asyncio-protocol asyncio DatagramProtocol5698558 Ref: 22e15698558 Ref: library/asyncio-protocol asyncio SubprocessProtocol5698674 Ref: 22bf5698674 Node: Base Protocol5698840 Ref: library/asyncio-protocol base-protocol5698950 Ref: 23045698950 Ref: library/asyncio-protocol asyncio BaseProtocol connection_made5699273 Ref: 22a15699273 Ref: library/asyncio-protocol asyncio BaseProtocol connection_lost5699527 Ref: 22e65699527 Ref: library/asyncio-protocol asyncio BaseProtocol pause_writing5700070 Ref: 22f45700070 Ref: library/asyncio-protocol asyncio BaseProtocol resume_writing5700186 Ref: 22f55700186 Node: Streaming Protocols5700650 Ref: library/asyncio-protocol streaming-protocols5700774 Ref: 23055700774 Ref: library/asyncio-protocol asyncio Protocol data_received5701184 Ref: 22ed5701184 Ref: library/asyncio-protocol asyncio Protocol eof_received5701865 Ref: 23065701865 Node: Buffered Streaming Protocols5702729 Ref: library/asyncio-protocol buffered-streaming-protocols5702858 Ref: 23075702858 Ref: library/asyncio-protocol asyncio BufferedProtocol get_buffer5703724 Ref: 23085703724 Ref: library/asyncio-protocol asyncio BufferedProtocol buffer_updated5704198 Ref: 23095704198 Ref: library/asyncio-protocol asyncio BufferedProtocol eof_received5704399 Ref: 230a5704399 Node: Datagram Protocols5704971 Ref: library/asyncio-protocol datagram-protocols5705101 Ref: 230b5705101 Ref: library/asyncio-protocol asyncio DatagramProtocol datagram_received5705299 Ref: 230c5705299 Ref: library/asyncio-protocol asyncio DatagramProtocol error_received5705564 Ref: 230d5705564 Node: Subprocess Protocols5706499 Ref: library/asyncio-protocol asyncio-subprocess-protocols5706592 Ref: 22535706592 Ref: library/asyncio-protocol subprocess-protocols5706592 Ref: 230e5706592 Ref: library/asyncio-protocol asyncio SubprocessProtocol pipe_data_received5706828 Ref: 230f5706828 Ref: library/asyncio-protocol asyncio SubprocessProtocol pipe_connection_lost5707101 Ref: 23105707101 Ref: library/asyncio-protocol asyncio SubprocessProtocol process_exited5707311 Ref: 23115707311 Node: Examples<15>5707409 Ref: library/asyncio-protocol examples5707500 Ref: 22e25707500 Node: TCP Echo Server5707755 Ref: library/asyncio-protocol asyncio-example-tcp-echo-server-protocol5707843 Ref: 22285707843 Ref: library/asyncio-protocol tcp-echo-server5707843 Ref: 23125707843 Node: TCP Echo Client5709127 Ref: library/asyncio-protocol asyncio-example-tcp-echo-client-protocol5709239 Ref: 22255709239 Ref: library/asyncio-protocol tcp-echo-client5709239 Ref: 23135709239 Node: UDP Echo Server5710797 Ref: library/asyncio-protocol asyncio-udp-echo-server-protocol5710909 Ref: 22a55710909 Ref: library/asyncio-protocol udp-echo-server5710909 Ref: 23145710909 Node: UDP Echo Client5712055 Ref: library/asyncio-protocol asyncio-udp-echo-client-protocol5712179 Ref: 22a45712179 Ref: library/asyncio-protocol udp-echo-client5712179 Ref: 23155712179 Node: Connecting Existing Sockets5713711 Ref: library/asyncio-protocol asyncio-example-create-connection5713863 Ref: 222c5713863 Ref: library/asyncio-protocol connecting-existing-sockets5713863 Ref: 23165713863 Node: loop subprocess_exec and SubprocessProtocol5715775 Ref: library/asyncio-protocol asyncio-example-subprocess-proto5715903 Ref: 226a5715903 Ref: library/asyncio-protocol loop-subprocess-exec-and-subprocessprotocol5715903 Ref: 23175715903 Node: Policies5717704 Ref: library/asyncio-policy doc5717835 Ref: 23185717835 Ref: library/asyncio-policy asyncio-policies5717835 Ref: 22895717835 Ref: library/asyncio-policy policies5717835 Ref: 23195717835 Node: Getting and Setting the Policy5718621 Ref: library/asyncio-policy getting-and-setting-the-policy5718719 Ref: 231b5718719 Ref: library/asyncio-policy asyncio get_event_loop_policy5718890 Ref: 231c5718890 Ref: library/asyncio-policy asyncio set_event_loop_policy5718984 Ref: 231d5718984 Node: Policy Objects5719165 Ref: library/asyncio-policy policy-objects5719288 Ref: 231e5719288 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy5719405 Ref: 231a5719405 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy get_event_loop5719500 Ref: 231f5719500 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy set_event_loop5719789 Ref: 23205719789 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy new_event_loop5719894 Ref: 23215719894 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy get_child_watcher5720039 Ref: 23225720039 Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy set_child_watcher5720275 Ref: 23245720275 Ref: library/asyncio-policy asyncio DefaultEventLoopPolicy5720480 Ref: 23255720480 Ref: library/asyncio-policy asyncio WindowsSelectorEventLoopPolicy5720886 Ref: 23265720886 Ref: library/asyncio-policy asyncio WindowsProactorEventLoopPolicy5721094 Ref: 23275721094 Node: Process Watchers5721301 Ref: library/asyncio-policy asyncio-watchers5721409 Ref: 22675721409 Ref: library/asyncio-policy process-watchers5721409 Ref: 23285721409 Ref: library/asyncio-policy asyncio get_child_watcher5722280 Ref: 232c5722280 Ref: library/asyncio-policy asyncio set_child_watcher5722387 Ref: 232d5722387 Ref: library/asyncio-policy asyncio AbstractChildWatcher5722819 Ref: 23235722819 Ref: library/asyncio-policy asyncio AbstractChildWatcher add_child_handler5722860 Ref: 232e5722860 Ref: library/asyncio-policy asyncio AbstractChildWatcher remove_child_handler5723253 Ref: 232f5723253 Ref: library/asyncio-policy asyncio AbstractChildWatcher attach_loop5723504 Ref: 23305723504 Ref: library/asyncio-policy asyncio AbstractChildWatcher is_active5723768 Ref: 23315723768 Ref: library/asyncio-policy asyncio AbstractChildWatcher close5724004 Ref: 23325724004 Ref: library/asyncio-policy asyncio ThreadedChildWatcher5724163 Ref: 22685724163 Ref: library/asyncio-policy asyncio MultiLoopChildWatcher5724633 Ref: 23295724633 Ref: library/asyncio-policy asyncio SafeChildWatcher5725292 Ref: 232a5725292 Ref: library/asyncio-policy asyncio FastChildWatcher5725881 Ref: 232b5725881 Node: Custom Policies5726349 Ref: library/asyncio-policy custom-policies5726434 Ref: 23335726434 Node: Platform Support5727041 Ref: library/asyncio-platforms doc5727168 Ref: 23345727168 Ref: library/asyncio-platforms asyncio-platform-support5727168 Ref: 22ae5727168 Ref: library/asyncio-platforms platform-support5727168 Ref: 23355727168 Node: All Platforms5727456 Ref: library/asyncio-platforms all-platforms5727538 Ref: 23365727538 Node: Windows5727702 Ref: library/asyncio-platforms windows5727798 Ref: 23375727798 Ref: Windows-Footnote-15729628 Ref: Windows-Footnote-25729711 Ref: Windows-Footnote-35729793 Ref: Windows-Footnote-45729874 Node: Subprocess Support on Windows5729939 Ref: library/asyncio-platforms asyncio-windows-subprocess5730012 Ref: 224f5730012 Ref: library/asyncio-platforms subprocess-support-on-windows5730012 Ref: 23395730012 Node: macOS5730395 Ref: library/asyncio-platforms macos5730469 Ref: 233a5730469 Node: High-level API Index5731101 Ref: library/asyncio-api-index doc5731239 Ref: 233c5731239 Ref: library/asyncio-api-index high-level-api-index5731239 Ref: 233d5731239 Node: Tasks5731517 Ref: library/asyncio-api-index tasks5731597 Ref: 233e5731597 Node: Queues<2>5734370 Ref: library/asyncio-api-index queues5734474 Ref: 233f5734474 Node: Subprocesses<2>5735293 Ref: library/asyncio-api-index subprocesses5735402 Ref: 23405735402 Node: Streams<2>5735964 Ref: library/asyncio-api-index streams5736079 Ref: 23415736079 Node: Synchronization5737514 Ref: library/asyncio-api-index synchronization5737628 Ref: 23425737628 Node: Exceptions<10>5738765 Ref: library/asyncio-api-index exceptions5738860 Ref: 23435738860 Node: Low-level API Index5739822 Ref: library/asyncio-llapi-index doc5739967 Ref: 23445739967 Ref: library/asyncio-llapi-index low-level-api-index5739967 Ref: 23455739967 Node: Obtaining the Event Loop5740239 Ref: library/asyncio-llapi-index obtaining-the-event-loop5740349 Ref: 23465740349 Node: Event Loop Methods<2>5741462 Ref: library/asyncio-llapi-index event-loop-methods5741594 Ref: 23475741594 Node: Transports<2>5753125 Ref: library/asyncio-llapi-index transports5753245 Ref: 23485753245 Node: Protocols<2>5759077 Ref: library/asyncio-llapi-index protocols5759195 Ref: 23495759195 Node: Event Loop Policies5762718 Ref: library/asyncio-llapi-index event-loop-policies5762814 Ref: 234a5762814 Node: Developing with asyncio5763643 Ref: library/asyncio-dev doc5763759 Ref: 234b5763759 Ref: library/asyncio-dev asyncio-dev5763759 Ref: 234c5763759 Ref: library/asyncio-dev developing-with-asyncio5763759 Ref: 234d5763759 Node: Debug Mode5764170 Ref: library/asyncio-dev asyncio-debug-mode5764279 Ref: feb5764279 Ref: library/asyncio-dev debug-mode5764279 Ref: 234e5764279 Node: Concurrency and Multithreading5765905 Ref: library/asyncio-dev asyncio-multithreading5766044 Ref: 21f65766044 Ref: library/asyncio-dev concurrency-and-multithreading5766044 Ref: 23515766044 Node: Running Blocking Code5768356 Ref: library/asyncio-dev asyncio-handle-blocking5768495 Ref: 23525768495 Ref: library/asyncio-dev running-blocking-code5768495 Ref: 23535768495 Node: Logging<3>5768990 Ref: library/asyncio-dev asyncio-logger5769130 Ref: 234f5769130 Ref: library/asyncio-dev logging5769130 Ref: 23545769130 Node: Detect never-awaited coroutines5769411 Ref: library/asyncio-dev asyncio-coroutine-not-scheduled5769563 Ref: 23505769563 Ref: library/asyncio-dev detect-never-awaited-coroutines5769563 Ref: 23555769563 Node: Detect never-retrieved exceptions5770572 Ref: library/asyncio-dev detect-never-retrieved-exceptions5770705 Ref: 23565770705 Ref: Detect never-retrieved exceptions-Footnote-15772314 Node: socket — Low-level networking interface5772378 Ref: library/socket doc5772585 Ref: 23575772585 Ref: library/socket module-socket5772585 Ref: ef5772585 Ref: library/socket socket-low-level-networking-interface5772585 Ref: 23585772585 Ref: socket — Low-level networking interface-Footnote-15773900 Node: Socket families5773965 Ref: library/socket socket-families5774082 Ref: 23595774082 Ref: library/socket host-port5775278 Ref: 235a5775278 Ref: Socket families-Footnote-15783231 Node: Module contents5783280 Ref: library/socket module-contents5783420 Ref: 23605783420 Node: Exceptions<11>5783627 Ref: library/socket exceptions5783714 Ref: 23615783714 Ref: library/socket socket error5783755 Ref: 9955783755 Ref: library/socket socket herror5783942 Ref: 23625783942 Ref: library/socket socket gaierror5784567 Ref: 23655784567 Ref: library/socket socket timeout5785172 Ref: c0e5785172 Ref: Exceptions<11>-Footnote-15785667 Node: Constants<8>5785716 Ref: library/socket constants5785824 Ref: 23675785824 Ref: library/socket socket AF_UNIX5786012 Ref: 22a35786012 Ref: library/socket socket AF_INET5786037 Ref: 229d5786037 Ref: library/socket socket AF_INET65786062 Ref: 229e5786062 Ref: library/socket socket SOCK_STREAM5786376 Ref: c8a5786376 Ref: library/socket socket SOCK_DGRAM5786405 Ref: c895786405 Ref: library/socket socket SOCK_RAW5786433 Ref: 23685786433 Ref: library/socket socket SOCK_RDM5786459 Ref: 23695786459 Ref: library/socket socket SOCK_SEQPACKET5786485 Ref: 236a5786485 Ref: library/socket socket SOCK_CLOEXEC5786784 Ref: 4975786784 Ref: library/socket socket SOCK_NONBLOCK5786814 Ref: 4965786814 Ref: library/socket socket SOMAXCONN5787243 Ref: 74c5787243 Ref: library/socket socket AF_CAN5788361 Ref: 235b5788361 Ref: library/socket socket PF_CAN5788385 Ref: 236b5788385 Ref: library/socket socket CAN_BCM5788643 Ref: 8b95788643 Ref: library/socket socket CAN_RAW_FD_FRAMES5789065 Ref: 7c55789065 Ref: library/socket socket CAN_ISOTP5789478 Ref: 235c5789478 Ref: library/socket socket AF_PACKET5789727 Ref: 235d5789727 Ref: library/socket socket PF_PACKET5789754 Ref: 236c5789754 Ref: library/socket socket AF_RDS5789968 Ref: 236d5789968 Ref: library/socket socket PF_RDS5789992 Ref: 236e5789992 Ref: library/socket socket SOL_RDS5790016 Ref: 236f5790016 Ref: library/socket socket SIO_RCVALL5790254 Ref: 23705790254 Ref: library/socket socket SIO_KEEPALIVE_VALS5790282 Ref: 23715790282 Ref: library/socket socket SIO_LOOPBACK_FAST_PATH5790318 Ref: 5815790318 Ref: library/socket socket AF_ALG5790737 Ref: 5845790737 Ref: library/socket socket SOL_ALG5790761 Ref: 23725790761 Ref: library/socket socket AF_VSOCK5790926 Ref: 3d35790926 Ref: library/socket socket IOCTL_VM_SOCKETS_GET_LOCAL_CID5790952 Ref: 23735790952 Ref: library/socket socket AF_LINK5791162 Ref: 8ba5791162 Ref: library/socket socket has_ipv65791256 Ref: 23745791256 Ref: library/socket socket BDADDR_ANY5791388 Ref: 23755791388 Ref: library/socket socket BDADDR_LOCAL5791416 Ref: 23765791416 Ref: library/socket socket HCI_FILTER5791685 Ref: 23775791685 Ref: library/socket socket HCI_TIME_STAMP5791713 Ref: 23785791713 Ref: library/socket socket HCI_DATA_DIR5791745 Ref: 23795791745 Ref: library/socket socket AF_QIPCRTR5792013 Ref: 235e5792013 Ref: Constants<8>-Footnote-15792244 Node: Functions<5>5792295 Ref: library/socket functions5792380 Ref: 237a5792380 Node: Creating sockets5792489 Ref: library/socket creating-sockets5792581 Ref: 237b5792581 Ref: library/socket socket socket5792698 Ref: 6745792698 Ref: library/socket socket socketpair5795121 Ref: 4815795121 Ref: library/socket socket create_connection5795858 Ref: b9e5795858 Ref: library/socket socket create_server5797017 Ref: 21e5797017 Ref: library/socket socket has_dualstack_ipv65798793 Ref: 21f5798793 Ref: library/socket socket fromfd5798988 Ref: 237d5798988 Ref: library/socket socket fromshare5799870 Ref: 4935799870 Ref: library/socket socket SocketType5800123 Ref: 237f5800123 Node: Other functions<2>5800276 Ref: library/socket other-functions5800368 Ref: 23805800368 Ref: library/socket socket close5800495 Ref: 3d15800495 Ref: library/socket socket getaddrinfo5800767 Ref: 22b15800767 Ref: library/socket socket getfqdn5803515 Ref: 23815803515 Ref: library/socket socket gethostbyname5804032 Ref: 23825804032 Ref: library/socket socket gethostbyname_ex5804632 Ref: 23635804632 Ref: library/socket socket gethostname5805406 Ref: 1bd65805406 Ref: library/socket socket gethostbyaddr5805792 Ref: 23645805792 Ref: library/socket socket getnameinfo5806488 Ref: 22b25806488 Ref: library/socket socket getprotobyname5807209 Ref: 23835807209 Ref: library/socket socket getservbyname5807663 Ref: 23845807663 Ref: library/socket socket getservbyport5808074 Ref: 23855808074 Ref: library/socket socket ntohl5808471 Ref: 23865808471 Ref: library/socket socket ntohs5808728 Ref: 46d5808728 Ref: library/socket socket htonl5809286 Ref: 23875809286 Ref: library/socket socket htons5809543 Ref: 46c5809543 Ref: library/socket socket inet_aton5810101 Ref: 23885810101 Ref: library/socket socket inet_ntoa5811038 Ref: 23895811038 Ref: library/socket socket inet_pton5811867 Ref: 8bb5811867 Ref: library/socket socket inet_ntop5812701 Ref: 8bc5812701 Ref: library/socket socket CMSG_LEN5813724 Ref: 238a5813724 Ref: library/socket socket CMSG_SPACE5814398 Ref: 238b5814398 Ref: library/socket socket getdefaulttimeout5815291 Ref: 237e5815291 Ref: library/socket socket setdefaulttimeout5815569 Ref: 23665815569 Ref: library/socket socket sethostname5815857 Ref: a875815857 Ref: library/socket socket if_nameindex5816187 Ref: 2205816187 Ref: library/socket socket if_nametoindex5816976 Ref: 2215816976 Ref: library/socket socket if_indextoname5817425 Ref: 2225817425 Ref: Other functions<2>-Footnote-15817912 Node: Socket Objects5817961 Ref: library/socket id15818110 Ref: 238c5818110 Ref: library/socket socket-objects5818110 Ref: 237c5818110 Ref: library/socket socket socket accept5818462 Ref: 6755818462 Ref: library/socket socket socket bind5819228 Ref: 238d5819228 Ref: library/socket socket socket close5819528 Ref: 6005819528 Ref: library/socket socket socket connect5820523 Ref: 6765820523 Ref: library/socket socket socket connect_ex5821595 Ref: 238f5821595 Ref: library/socket socket socket detach5822174 Ref: b9d5822174 Ref: library/socket socket socket dup5822415 Ref: 23905822415 Ref: library/socket socket socket fileno5822597 Ref: 23915822597 Ref: library/socket socket socket get_inheritable5822958 Ref: 7ff5822958 Ref: library/socket socket socket getpeername5823220 Ref: 22e75823220 Ref: library/socket socket socket getsockname5823559 Ref: 22e85823559 Ref: library/socket socket socket getsockopt5823808 Ref: 5825823808 Ref: library/socket socket socket getblocking5824504 Ref: 3d05824504 Ref: library/socket socket socket gettimeout5824726 Ref: 23925824726 Ref: library/socket socket socket ioctl5824973 Ref: 5805824973 Ref: library/socket socket socket listen5825610 Ref: 74b5825610 Ref: library/socket socket socket makefile5826036 Ref: b195826036 Ref: library/socket socket socket recv5827151 Ref: 6775827151 Ref: library/socket socket socket recvfrom5827947 Ref: 6785827947 Ref: library/socket socket socket recvmsg5828883 Ref: 6795828883 Ref: library/socket socket socket recvmsg_into5832814 Ref: a865832814 Ref: library/socket socket socket recvfrom_into5834456 Ref: cb35834456 Ref: library/socket socket socket recv_into5834990 Ref: cb25834990 Ref: library/socket socket socket send5835437 Ref: 67a5835437 Ref: library/socket socket socket sendall5836250 Ref: 67b5836250 Ref: library/socket socket socket sendto5837224 Ref: 67d5837224 Ref: library/socket socket socket sendmsg5838054 Ref: 67c5838054 Ref: library/socket socket socket sendmsg_afalg5840219 Ref: 5855840219 Ref: library/socket socket socket sendfile5840556 Ref: 74a5840556 Ref: library/socket socket socket set_inheritable5841460 Ref: 8005841460 Ref: library/socket socket socket setblocking5841640 Ref: 1be55841640 Ref: library/socket socket socket settimeout5842212 Ref: 235f5842212 Ref: library/socket socket socket setsockopt5842948 Ref: 5835842948 Ref: library/socket socket socket shutdown5844026 Ref: 238e5844026 Ref: library/socket socket socket share5844322 Ref: 4945844322 Ref: library/socket socket socket family5845187 Ref: 23965845187 Ref: library/socket socket socket type5845242 Ref: 4985845242 Ref: library/socket socket socket proto5845293 Ref: 23975845293 Ref: Socket Objects-Footnote-15845385 Ref: Socket Objects-Footnote-25845434 Ref: Socket Objects-Footnote-35845483 Ref: Socket Objects-Footnote-45845557 Ref: Socket Objects-Footnote-55845606 Ref: Socket Objects-Footnote-65845655 Ref: Socket Objects-Footnote-75845704 Ref: Socket Objects-Footnote-85845753 Ref: Socket Objects-Footnote-95845802 Ref: Socket Objects-Footnote-105845851 Node: Notes on socket timeouts5845901 Ref: library/socket notes-on-socket-timeouts5846045 Ref: 23985846045 Ref: library/socket socket-timeouts5846045 Ref: 23955846045 Node: Timeouts and the connect method5847402 Ref: library/socket timeouts-and-the-connect-method5847533 Ref: 23995847533 Node: Timeouts and the accept method5848008 Ref: library/socket timeouts-and-the-accept-method5848139 Ref: 239a5848139 Node: Example<8>5848880 Ref: library/socket example5849001 Ref: 239b5849001 Ref: library/socket socket-example5849001 Ref: 239c5849001 Ref: Example<8>-Footnote-15856742 Node: ssl — TLS/SSL wrapper for socket objects5856791 Ref: library/ssl doc5857007 Ref: 239d5857007 Ref: library/ssl module-ssl5857007 Ref: f35857007 Ref: library/ssl ssl-tls-ssl-wrapper-for-socket-objects5857007 Ref: 239e5857007 Ref: ssl — TLS/SSL wrapper for socket objects-Footnote-15859614 Node: Functions Constants and Exceptions5859676 Ref: library/ssl functions-constants-and-exceptions5859809 Ref: 239f5859809 Node: Socket creation5860057 Ref: library/ssl socket-creation5860168 Ref: 23a05860168 Node: Context creation5861935 Ref: library/ssl context-creation5862069 Ref: 23a15862069 Ref: library/ssl ssl create_default_context5862211 Ref: 8c15862211 Ref: Context creation-Footnote-15865069 Node: Exceptions<12>5865114 Ref: library/ssl exceptions5865250 Ref: 23a75865250 Ref: library/ssl ssl SSLError5865291 Ref: c0f5865291 Ref: library/ssl ssl SSLError library5865863 Ref: a985865863 Ref: library/ssl ssl SSLError reason5866141 Ref: a995866141 Ref: library/ssl ssl SSLZeroReturnError5866400 Ref: 23a85866400 Ref: library/ssl ssl SSLWantReadError5866694 Ref: 7565866694 Ref: library/ssl ssl SSLWantWriteError5867001 Ref: 7575867001 Ref: library/ssl ssl SSLSyscallError5867305 Ref: 23aa5867305 Ref: library/ssl ssl SSLEOFError5867594 Ref: 23ab5867594 Ref: library/ssl ssl SSLCertVerificationError5867862 Ref: 3dd5867862 Ref: library/ssl ssl SSLCertVerificationError verify_code5868026 Ref: 23ac5868026 Ref: library/ssl ssl SSLCertVerificationError verify_message5868130 Ref: 23ad5868130 Ref: library/ssl ssl CertificateError5868228 Ref: 23ae5868228 Node: Random generation5868427 Ref: library/ssl random-generation5868567 Ref: 23af5868567 Ref: library/ssl ssl RAND_bytes5868622 Ref: a8f5868622 Ref: library/ssl ssl RAND_pseudo_bytes5869294 Ref: a905869294 Ref: library/ssl ssl RAND_status5870144 Ref: 23b05870144 Ref: library/ssl ssl RAND_egd5870471 Ref: 23b25870471 Ref: library/ssl ssl RAND_add5871127 Ref: 23b15871127 Ref: Random generation-Footnote-15871569 Ref: Random generation-Footnote-25871663 Node: Certificate handling5871712 Ref: library/ssl certificate-handling5871850 Ref: 23b35871850 Ref: library/ssl ssl match_hostname5871911 Ref: 3dc5871911 Ref: library/ssl ssl cert_time_to_seconds5873852 Ref: 7585873852 Ref: library/ssl ssl get_server_certificate5874762 Ref: a9a5874762 Ref: library/ssl ssl DER_cert_to_PEM_cert5875773 Ref: 23b55875773 Ref: library/ssl ssl PEM_cert_to_DER_cert5875955 Ref: 23b65875955 Ref: library/ssl ssl get_default_verify_paths5876135 Ref: 8c25876135 Ref: library/ssl ssl enum_certificates5877140 Ref: 8ce5877140 Ref: library/ssl ssl enum_crls5878016 Ref: 8cf5878016 Ref: library/ssl ssl wrap_socket5878546 Ref: 46f5878546 Ref: Certificate handling-Footnote-15880039 Ref: Certificate handling-Footnote-25880088 Ref: Certificate handling-Footnote-35880137 Ref: Certificate handling-Footnote-45880186 Ref: Certificate handling-Footnote-55880235 Node: Constants<9>5880284 Ref: library/ssl constants5880396 Ref: 23b95880396 Ref: library/ssl ssl CERT_NONE5880561 Ref: 23ba5880561 Ref: library/ssl ssl CERT_OPTIONAL5881178 Ref: 23bc5881178 Ref: library/ssl ssl CERT_REQUIRED5882083 Ref: 23a55882083 Ref: library/ssl ssl VerifyMode5883208 Ref: 23be5883208 Ref: library/ssl ssl VERIFY_DEFAULT5883324 Ref: 8c75883324 Ref: library/ssl ssl VERIFY_CRL_CHECK_LEAF5883577 Ref: 8c85883577 Ref: library/ssl ssl VERIFY_CRL_CHECK_CHAIN5884022 Ref: 8c95884022 Ref: library/ssl ssl VERIFY_X509_STRICT5884228 Ref: 8ca5884228 Ref: library/ssl ssl VERIFY_X509_TRUSTED_FIRST5884408 Ref: 23bf5884408 Ref: library/ssl ssl VerifyFlags5884697 Ref: 23c05884697 Ref: library/ssl ssl PROTOCOL_TLS5884817 Ref: 23a25884817 Ref: library/ssl ssl PROTOCOL_TLS_CLIENT5885047 Ref: 23bb5885047 Ref: library/ssl ssl PROTOCOL_TLS_SERVER5885361 Ref: 23c15885361 Ref: library/ssl ssl PROTOCOL_SSLv235885577 Ref: 23c25885577 Ref: library/ssl ssl PROTOCOL_SSLv25885730 Ref: 23c35885730 Ref: library/ssl ssl PROTOCOL_SSLv35886095 Ref: 23b45886095 Ref: library/ssl ssl PROTOCOL_TLSv15886587 Ref: 23c45886587 Ref: library/ssl ssl PROTOCOL_TLSv1_15886886 Ref: 8bf5886886 Ref: library/ssl ssl PROTOCOL_TLSv1_25887262 Ref: 8c05887262 Ref: library/ssl ssl OP_ALL5887764 Ref: 23c55887764 Ref: library/ssl ssl OP_NO_SSLv25888021 Ref: ba05888021 Ref: library/ssl ssl OP_NO_SSLv35888322 Ref: 23a35888322 Ref: library/ssl ssl OP_NO_TLSv15888623 Ref: 23c65888623 Ref: library/ssl ssl OP_NO_TLSv1_15889062 Ref: 23c75889062 Ref: library/ssl ssl OP_NO_TLSv1_25889449 Ref: 23c85889449 Ref: library/ssl ssl OP_NO_TLSv1_35889836 Ref: 23c95889836 Ref: library/ssl ssl OP_NO_RENEGOTIATION5890427 Ref: 23ca5890427 Ref: library/ssl ssl OP_CIPHER_SERVER_PREFERENCE5890708 Ref: a9b5890708 Ref: library/ssl ssl OP_SINGLE_DH_USE5890939 Ref: 23cb5890939 Ref: library/ssl ssl OP_SINGLE_ECDH_USE5891193 Ref: 23cc5891193 Ref: library/ssl ssl OP_ENABLE_MIDDLEBOX_COMPAT5891451 Ref: 23cd5891451 Ref: library/ssl ssl OP_NO_COMPRESSION5891728 Ref: a965891728 Ref: library/ssl ssl Options5891985 Ref: 23ce5891985 Ref: library/ssl ssl OP_NO_TICKET5892071 Ref: 23cf5892071 Ref: library/ssl ssl HAS_ALPN5892185 Ref: 7535892185 Ref: library/ssl ssl HAS_NEVER_CHECK_COMMON_NAME5892392 Ref: 23d05892392 Ref: library/ssl ssl HAS_ECDH5892628 Ref: 23d15892628 Ref: library/ssl ssl HAS_SNI5892885 Ref: 23d25892885 Ref: library/ssl ssl HAS_NPN5893066 Ref: 23d35893066 Ref: library/ssl ssl HAS_SSLv25893417 Ref: 23d45893417 Ref: library/ssl ssl HAS_SSLv35893554 Ref: 23d55893554 Ref: library/ssl ssl HAS_TLSv15893691 Ref: 23d65893691 Ref: library/ssl ssl HAS_TLSv1_15893828 Ref: 3e95893828 Ref: library/ssl ssl HAS_TLSv1_25893967 Ref: 23d75893967 Ref: library/ssl ssl HAS_TLSv1_35894106 Ref: 23d85894106 Ref: library/ssl ssl CHANNEL_BINDING_TYPES5894245 Ref: 23d95894245 Ref: library/ssl ssl OPENSSL_VERSION5894463 Ref: ba15894463 Ref: library/ssl ssl OPENSSL_VERSION_INFO5894675 Ref: ba25894675 Ref: library/ssl ssl OPENSSL_VERSION_NUMBER5894901 Ref: ba35894901 Ref: library/ssl ssl ALERT_DESCRIPTION_HANDSHAKE_FAILURE5895170 Ref: 23da5895170 Ref: library/ssl ssl ALERT_DESCRIPTION_INTERNAL_ERROR5895220 Ref: 23db5895220 Ref: library/ssl ssl AlertDescription5895612 Ref: 23dc5895612 Ref: library/ssl ssl Purpose SERVER_AUTH5895752 Ref: 8cc5895752 Ref: library/ssl ssl Purpose CLIENT_AUTH5896065 Ref: 8cd5896065 Ref: library/ssl ssl SSLErrorNumber5896378 Ref: 23dd5896378 Ref: library/ssl ssl TLSVersion5896503 Ref: 23de5896503 Ref: library/ssl ssl TLSVersion MINIMUM_SUPPORTED5896718 Ref: 23df5896718 Ref: library/ssl ssl TLSVersion MAXIMUM_SUPPORTED5896763 Ref: 23e05896763 Ref: library/ssl ssl TLSVersion SSLv35896986 Ref: 23e15896986 Ref: library/ssl ssl TLSVersion TLSv15897019 Ref: 23e25897019 Ref: library/ssl ssl TLSVersion TLSv1_15897052 Ref: 23e35897052 Ref: library/ssl ssl TLSVersion TLSv1_25897087 Ref: 23e45897087 Ref: library/ssl ssl TLSVersion TLSv1_35897122 Ref: 23e55897122 Ref: Constants<9>-Footnote-15897219 Ref: Constants<9>-Footnote-25897268 Ref: Constants<9>-Footnote-35897317 Ref: Constants<9>-Footnote-45897395 Ref: Constants<9>-Footnote-55897444 Node: SSL Sockets5897537 Ref: library/ssl ssl-sockets5897691 Ref: 23e65897691 Ref: library/ssl ssl SSLSocket5897734 Ref: 3e25897734 Ref: library/ssl ssl SSLSocket read5899910 Ref: 75b5899910 Ref: library/ssl ssl SSLSocket write5900730 Ref: 75c5900730 Ref: library/ssl ssl SSLSocket do_handshake5901960 Ref: 75a5901960 Ref: library/ssl ssl SSLSocket getpeercert5902724 Ref: 8d15902724 Ref: library/ssl ssl SSLSocket cipher5906337 Ref: 22e95906337 Ref: library/ssl ssl SSLSocket shared_ciphers5906621 Ref: 7595906621 Ref: library/ssl ssl SSLSocket compression5907102 Ref: a955907102 Ref: library/ssl ssl SSLSocket get_channel_binding5907447 Ref: a945907447 Ref: library/ssl ssl SSLSocket selected_alpn_protocol5908080 Ref: 7525908080 Ref: library/ssl ssl SSLSocket selected_npn_protocol5908491 Ref: 23e95908491 Ref: library/ssl ssl SSLSocket unwrap5908845 Ref: 23e75908845 Ref: library/ssl ssl SSLSocket verify_client_post_handshake5909268 Ref: 2255909268 Ref: library/ssl ssl SSLSocket version5910146 Ref: 7555910146 Ref: library/ssl ssl SSLSocket pending5910557 Ref: 23ea5910557 Ref: library/ssl ssl SSLSocket context5910695 Ref: 23e85910695 Ref: library/ssl ssl SSLSocket server_side5911043 Ref: 23eb5911043 Ref: library/ssl ssl SSLSocket server_hostname5911213 Ref: 3e05911213 Ref: library/ssl ssl SSLSocket session5911716 Ref: 23ec5911716 Ref: library/ssl ssl SSLSocket session_reused5912072 Ref: 23ed5912072 Ref: SSL Sockets-Footnote-15912175 Ref: SSL Sockets-Footnote-25912224 Node: SSL Contexts5912273 Ref: library/ssl ssl-contexts5912405 Ref: 23ee5912405 Ref: library/ssl ssl SSLContext5912749 Ref: 3e45912749 Ref: library/ssl ssl SSLContext cert_store_stats5916736 Ref: 8c45916736 Ref: library/ssl ssl SSLContext load_cert_chain5917140 Ref: a915917140 Ref: library/ssl ssl SSLContext load_default_certs5918766 Ref: 8cb5918766 Ref: library/ssl ssl SSLContext load_verify_locations5919590 Ref: 7eb5919590 Ref: library/ssl ssl SSLContext get_ca_certs5920920 Ref: 8c55920920 Ref: library/ssl ssl SSLContext get_ciphers5921555 Ref: 58c5921555 Ref: library/ssl ssl SSLContext set_default_verify_paths5923696 Ref: 8c35923696 Ref: library/ssl ssl SSLContext set_ciphers5924165 Ref: 23b85924165 Ref: library/ssl ssl SSLContext set_alpn_protocols5924813 Ref: 7515924813 Ref: library/ssl ssl SSLContext set_npn_protocols5925701 Ref: a975925701 Ref: library/ssl ssl SSLContext sni_callback5926370 Ref: 23f05926370 Ref: library/ssl ssl SSLContext set_servername_callback5928938 Ref: 8d05928938 Ref: library/ssl ssl SSLContext load_dh_params5929619 Ref: a925929619 Ref: library/ssl ssl SSLContext set_ecdh_curve5930162 Ref: a935930162 Ref: library/ssl ssl SSLContext wrap_socket5930889 Ref: 3e55930889 Ref: library/ssl ssl SSLContext sslsocket_class5933676 Ref: 23f15933676 Ref: library/ssl ssl SSLContext wrap_bio5933972 Ref: 3e65933972 Ref: library/ssl ssl SSLContext sslobject_class5934711 Ref: 23f25934711 Ref: library/ssl ssl SSLContext session_stats5935004 Ref: 23f35935004 Ref: library/ssl ssl SSLContext check_hostname5935469 Ref: 23bd5935469 Ref: library/ssl ssl SSLContext keylog_filename5937060 Ref: 23a65937060 Ref: library/ssl ssl SSLContext maximum_version5937568 Ref: 3e85937568 Ref: library/ssl ssl SSLContext minimum_version5938551 Ref: 3e75938551 Ref: library/ssl ssl SSLContext num_tickets5938885 Ref: 23f45938885 Ref: library/ssl ssl SSLContext options5939232 Ref: 23b75939232 Ref: library/ssl ssl SSLContext post_handshake_auth5939979 Ref: 2245939979 Ref: library/ssl ssl SSLContext protocol5940962 Ref: 23f55940962 Ref: library/ssl ssl SSLContext hostname_checks_common_name5941098 Ref: 3de5941098 Ref: library/ssl ssl SSLContext verify_flags5941419 Ref: 8c65941419 Ref: library/ssl ssl SSLContext verify_mode5942003 Ref: 23a45942003 Ref: SSL Contexts-Footnote-15942509 Ref: SSL Contexts-Footnote-25942667 Ref: SSL Contexts-Footnote-35942758 Ref: SSL Contexts-Footnote-45942850 Ref: SSL Contexts-Footnote-55943008 Ref: SSL Contexts-Footnote-65943099 Ref: SSL Contexts-Footnote-75943191 Ref: SSL Contexts-Footnote-85943279 Ref: SSL Contexts-Footnote-95943344 Ref: SSL Contexts-Footnote-105943393 Ref: SSL Contexts-Footnote-115943472 Ref: SSL Contexts-Footnote-125943522 Ref: SSL Contexts-Footnote-135943599 Node: Certificates5943676 Ref: library/ssl certificates5943809 Ref: 23f65943809 Ref: library/ssl ssl-certificates5943809 Ref: 23ef5943809 Ref: Certificates-Footnote-15946158 Node: Certificate chains5946207 Ref: library/ssl certificate-chains5946298 Ref: 23f75946298 Node: CA certificates5947569 Ref: library/ssl ca-certificates5947697 Ref: 23f85947697 Node: Combined key and certificate5948287 Ref: library/ssl combined-key-and-certificate5948421 Ref: 23f95948421 Node: Self-signed certificates5949067 Ref: library/ssl self-signed-certificates5949177 Ref: 23fa5949177 Node: Examples<16>5950875 Ref: library/ssl examples5951025 Ref: 23fb5951025 Node: Testing for SSL support5951154 Ref: library/ssl testing-for-ssl-support5951256 Ref: 23fc5951256 Node: Client-side operation5951570 Ref: library/ssl client-side-operation5951702 Ref: 23fd5951702 Node: Server-side operation5956444 Ref: library/ssl server-side-operation5956544 Ref: 23fe5956544 Node: Notes on non-blocking sockets5958554 Ref: library/ssl notes-on-non-blocking-sockets5958713 Ref: 23ff5958713 Ref: library/ssl ssl-nonblocking5958713 Ref: 23a95958713 Node: Memory BIO Support<2>5961601 Ref: library/ssl memory-bio-support5961759 Ref: 24015961759 Ref: library/ssl ssl SSLObject5962875 Ref: 3e35962875 Ref: library/ssl ssl MemoryBIO5966638 Ref: 74f5966638 Ref: library/ssl ssl MemoryBIO pending5966766 Ref: 24025966766 Ref: library/ssl ssl MemoryBIO eof5966865 Ref: 24035966865 Ref: library/ssl ssl MemoryBIO read5966995 Ref: 24045966995 Ref: library/ssl ssl MemoryBIO write5967153 Ref: 24055967153 Ref: library/ssl ssl MemoryBIO write_eof5967435 Ref: 24065967435 Node: SSL session5967727 Ref: library/ssl ssl-session5967879 Ref: 24075967879 Ref: library/ssl ssl SSLSession5967945 Ref: 58b5967945 Ref: library/ssl ssl SSLSession id5968022 Ref: 24085968022 Ref: library/ssl ssl SSLSession time5968046 Ref: 24095968046 Ref: library/ssl ssl SSLSession timeout5968072 Ref: 240a5968072 Ref: library/ssl ssl SSLSession ticket_lifetime_hint5968101 Ref: 240b5968101 Ref: library/ssl ssl SSLSession has_ticket5968143 Ref: 240c5968143 Node: Security considerations5968175 Ref: library/ssl security-considerations5968313 Ref: 240d5968313 Ref: library/ssl ssl-security5968313 Ref: 22a25968313 Node: Best defaults5968451 Ref: library/ssl best-defaults5968548 Ref: 240e5968548 Node: Manual settings5969709 Ref: library/ssl manual-settings5969831 Ref: 240f5969831 Node: Verifying certificates5969964 Ref: library/ssl verifying-certificates5970064 Ref: 24105970064 Node: Protocol versions5971327 Ref: library/ssl protocol-versions5971452 Ref: 24115971452 Node: Cipher selection5972253 Ref: library/ssl cipher-selection5972347 Ref: 24125972347 Ref: Cipher selection-Footnote-15973003 Node: Multi-processing5973088 Ref: library/ssl multi-processing5973188 Ref: 24135973188 Node: TLS 1 35973743 Ref: library/ssl ssl-tlsv1-35973886 Ref: 3e15973886 Ref: library/ssl tls-1-35973886 Ref: 24145973886 Node: LibreSSL support5975057 Ref: library/ssl libressl-support5975168 Ref: 24155975168 Ref: library/ssl ssl-libressl5975168 Ref: 24165975168 Ref: LibreSSL support-Footnote-15976792 Ref: LibreSSL support-Footnote-25976858 Ref: LibreSSL support-Footnote-35976907 Ref: LibreSSL support-Footnote-45976956 Ref: LibreSSL support-Footnote-55977005 Ref: LibreSSL support-Footnote-65977054 Ref: LibreSSL support-Footnote-75977103 Ref: LibreSSL support-Footnote-85977179 Ref: LibreSSL support-Footnote-95977228 Node: select — Waiting for I/O completion5977286 Ref: library/select doc5977502 Ref: 24175977502 Ref: library/select module-select5977502 Ref: e55977502 Ref: library/select select-waiting-for-i-o-completion5977502 Ref: 24185977502 Ref: library/select select error5978510 Ref: 9965978510 Ref: library/select select devpoll5978697 Ref: 8ab5978697 Ref: library/select select epoll5979417 Ref: 8a95979417 Ref: library/select select poll5980903 Ref: 24005980903 Ref: library/select select kqueue5981222 Ref: 241c5981222 Ref: library/select select kevent5981561 Ref: 241e5981561 Ref: library/select select select5981838 Ref: 6735981838 Ref: library/select select PIPE_BUF5984107 Ref: b865984107 Ref: select — Waiting for I/O completion-Footnote-15984802 Ref: select — Waiting for I/O completion-Footnote-25984851 Node: /dev/poll Polling Objects5984900 Ref: library/select dev-poll-polling-objects5985052 Ref: 24205985052 Ref: library/select devpoll-objects5985052 Ref: 24195985052 Ref: library/select select devpoll close5985406 Ref: 8ad5985406 Ref: library/select select devpoll closed5985517 Ref: 8ae5985517 Ref: library/select select devpoll fileno5985624 Ref: 8ac5985624 Ref: library/select select devpoll register5985744 Ref: 24215985744 Ref: library/select select devpoll modify5986728 Ref: 24225986728 Ref: library/select select devpoll unregister5986936 Ref: 24235986936 Ref: library/select select devpoll poll5987293 Ref: 66f5987293 Ref: /dev/poll Polling Objects-Footnote-15988436 Node: Edge and Level Trigger Polling epoll Objects5988485 Ref: library/select edge-and-level-trigger-polling-epoll-objects5988661 Ref: 24245988661 Ref: library/select epoll-objects5988661 Ref: 241a5988661 Ref: library/select select epoll close5991529 Ref: 8aa5991529 Ref: library/select select epoll closed5991618 Ref: 24255991618 Ref: library/select select epoll fileno5991695 Ref: 24265991695 Ref: library/select select epoll fromfd5991783 Ref: 24275991783 Ref: library/select select epoll register5991873 Ref: 24285991873 Ref: library/select select epoll modify5991973 Ref: 24295991973 Ref: library/select select epoll unregister5992058 Ref: 242a5992058 Ref: library/select select epoll poll5992158 Ref: 6705992158 Ref: Edge and Level Trigger Polling epoll Objects-Footnote-15992560 Node: Polling Objects5992609 Ref: library/select poll-objects5992774 Ref: 241b5992774 Ref: library/select polling-objects5992774 Ref: 242b5992774 Ref: library/select select poll register5993341 Ref: 242c5993341 Ref: library/select select poll modify5995318 Ref: 242d5995318 Ref: library/select select poll unregister5995619 Ref: 242e5995619 Ref: library/select select poll poll5996008 Ref: 6725996008 Ref: Polling Objects-Footnote-15997154 Node: Kqueue Objects5997203 Ref: library/select id15997338 Ref: 242f5997338 Ref: library/select kqueue-objects5997338 Ref: 241d5997338 Ref: library/select select kqueue close5997387 Ref: 24305997387 Ref: library/select select kqueue closed5997478 Ref: 24315997478 Ref: library/select select kqueue fileno5997557 Ref: 24325997557 Ref: library/select select kqueue fromfd5997646 Ref: 24335997646 Ref: library/select select kqueue control5997737 Ref: 6715997737 Ref: Kqueue Objects-Footnote-15998388 Node: Kevent Objects5998437 Ref: library/select id25998548 Ref: 24345998548 Ref: library/select kevent-objects5998548 Ref: 241f5998548 Ref: library/select select kevent ident5998663 Ref: 24355998663 Ref: library/select select kevent filter5998965 Ref: 24365998965 Ref: library/select select kevent flags6000747 Ref: 24376000747 Ref: library/select select kevent fflags6002408 Ref: 24386002408 Ref: library/select select kevent data6006153 Ref: 24396006153 Ref: library/select select kevent udata6006209 Ref: 243a6006209 Node: selectors — High-level I/O multiplexing6006264 Ref: library/selectors doc6006478 Ref: 243b6006478 Ref: library/selectors module-selectors6006478 Ref: e66006478 Ref: library/selectors selectors-high-level-i-o-multiplexing6006478 Ref: 243c6006478 Ref: selectors — High-level I/O multiplexing-Footnote-16006836 Node: Introduction<9>6006904 Ref: library/selectors introduction6007016 Ref: 243d6007016 Node: Classes<3>6008183 Ref: library/selectors classes6008316 Ref: 24406008316 Ref: library/selectors selectors SelectorKey6009095 Ref: 24416009095 Ref: library/selectors selectors SelectorKey fileobj6009373 Ref: 24426009373 Ref: library/selectors selectors SelectorKey fd6009437 Ref: 24436009437 Ref: library/selectors selectors SelectorKey events6009500 Ref: 24446009500 Ref: library/selectors selectors SelectorKey data6009591 Ref: 24456009591 Ref: library/selectors selectors BaseSelector6009757 Ref: 243e6009757 Ref: library/selectors selectors BaseSelector register6010433 Ref: 24466010433 Ref: library/selectors selectors BaseSelector unregister6011087 Ref: 24476011087 Ref: library/selectors selectors BaseSelector modify6011707 Ref: 44b6011707 Ref: library/selectors selectors BaseSelector select6012307 Ref: 24486012307 Ref: library/selectors selectors BaseSelector close6013606 Ref: 24496013606 Ref: library/selectors selectors BaseSelector get_key6013824 Ref: 244a6013824 Ref: library/selectors selectors BaseSelector get_map6014111 Ref: 244b6014111 Ref: library/selectors selectors DefaultSelector6014380 Ref: 243f6014380 Ref: library/selectors selectors SelectSelector6014588 Ref: 23386014588 Ref: library/selectors selectors PollSelector6014675 Ref: 44d6014675 Ref: library/selectors selectors EpollSelector6014759 Ref: 44c6014759 Ref: library/selectors selectors EpollSelector fileno6014844 Ref: 244c6014844 Ref: library/selectors selectors DevpollSelector6014984 Ref: 44e6014984 Ref: library/selectors selectors DevpollSelector fileno6015073 Ref: 244d6015073 Ref: library/selectors selectors KqueueSelector6015241 Ref: 233b6015241 Ref: library/selectors selectors KqueueSelector fileno6015329 Ref: 244e6015329 Ref: Classes<3>-Footnote-16015507 Node: Examples<17>6015556 Ref: library/selectors examples6015665 Ref: 244f6015665 Node: asyncore — Asynchronous socket handler6016692 Ref: library/asyncore doc6016926 Ref: 24506016926 Ref: library/asyncore asyncore-asynchronous-socket-handler6016926 Ref: 24516016926 Ref: library/asyncore module-asyncore6016926 Ref: b6016926 Ref: library/asyncore asyncore loop6019226 Ref: 24526019226 Ref: library/asyncore asyncore dispatcher6020256 Ref: bc36020256 Ref: library/asyncore asyncore dispatcher handle_read6022175 Ref: 24556022175 Ref: library/asyncore asyncore dispatcher handle_write6022336 Ref: 24566022336 Ref: library/asyncore asyncore dispatcher handle_expt6022712 Ref: 24576022712 Ref: library/asyncore asyncore dispatcher handle_connect6022924 Ref: 24586022924 Ref: library/asyncore asyncore dispatcher handle_close6023171 Ref: 24596023171 Ref: library/asyncore asyncore dispatcher handle_error6023250 Ref: 245a6023250 Ref: library/asyncore asyncore dispatcher handle_accept6023417 Ref: bc56023417 Ref: library/asyncore asyncore dispatcher handle_accepted6023796 Ref: bc46023796 Ref: library/asyncore asyncore dispatcher readable6024284 Ref: 24536024284 Ref: library/asyncore asyncore dispatcher writable6024636 Ref: 24546024636 Ref: library/asyncore asyncore dispatcher create_socket6025143 Ref: 245c6025143 Ref: library/asyncore asyncore dispatcher connect6025542 Ref: 245b6025542 Ref: library/asyncore asyncore dispatcher send6025743 Ref: 245d6025743 Ref: library/asyncore asyncore dispatcher recv6025835 Ref: 245e6025835 Ref: library/asyncore asyncore dispatcher listen6026282 Ref: 245f6026282 Ref: library/asyncore asyncore dispatcher bind6026553 Ref: 24606026553 Ref: library/asyncore asyncore dispatcher accept6026992 Ref: bc66026992 Ref: library/asyncore asyncore dispatcher close6027634 Ref: 24616027634 Ref: library/asyncore asyncore dispatcher_with_send6027922 Ref: 24626027922 Ref: library/asyncore asyncore file_dispatcher6028153 Ref: 24636028153 Ref: library/asyncore asyncore file_wrapper6028582 Ref: 24646028582 Ref: asyncore — Asynchronous socket handler-Footnote-16029098 Node: asyncore Example basic HTTP client6029165 Ref: library/asyncore asyncore-example-16029319 Ref: 24656029319 Ref: library/asyncore asyncore-example-basic-http-client6029319 Ref: 24666029319 Node: asyncore Example basic echo server6030329 Ref: library/asyncore asyncore-example-26030483 Ref: 24676030483 Ref: library/asyncore asyncore-example-basic-echo-server6030483 Ref: 24686030483 Node: asynchat — Asynchronous socket command/response handler6031410 Ref: library/asynchat doc6031650 Ref: 24696031650 Ref: library/asynchat asynchat-asynchronous-socket-command-response-handler6031650 Ref: 246a6031650 Ref: library/asynchat module-asynchat6031650 Ref: 96031650 Ref: library/asynchat asynchat async_chat6032861 Ref: 8b56032861 Ref: library/asynchat asynchat async_chat ac_in_buffer_size6033776 Ref: 246d6033776 Ref: library/asynchat asynchat async_chat ac_out_buffer_size6033878 Ref: 246e6033878 Ref: library/asynchat asynchat async_chat close_when_done6035073 Ref: 24706035073 Ref: library/asynchat asynchat async_chat collect_incoming_data6035253 Ref: 246b6035253 Ref: library/asynchat asynchat async_chat discard_buffers6035485 Ref: 24716035485 Ref: library/asynchat asynchat async_chat found_terminator6035652 Ref: 246c6035652 Ref: library/asynchat asynchat async_chat get_terminator6036001 Ref: 24726036001 Ref: library/asynchat asynchat async_chat push6036097 Ref: 24736036097 Ref: library/asynchat asynchat async_chat push_with_producer6036434 Ref: 24746036434 Ref: library/asynchat asynchat async_chat set_terminator6036783 Ref: 246f6036783 Ref: asynchat — Asynchronous socket command/response handler-Footnote-16037873 Node: asynchat Example6037940 Ref: library/asynchat asynchat-example6038050 Ref: 24756038050 Ref: library/asynchat id16038050 Ref: 24766038050 Node: signal — Set handlers for asynchronous events6040399 Ref: library/signal doc6040634 Ref: 24776040634 Ref: library/signal module-signal6040634 Ref: ea6040634 Ref: library/signal signal-set-handlers-for-asynchronous-events6040634 Ref: 24786040634 Node: General rules6040996 Ref: library/signal general-rules6041120 Ref: 24796041120 Node: Execution of Python signal handlers6041936 Ref: library/signal execution-of-python-signal-handlers6042049 Ref: 247c6042049 Node: Signals and threads6043208 Ref: library/signal id16043321 Ref: 24806043321 Ref: library/signal signals-and-threads6043321 Ref: 24816043321 Node: Module contents<2>6043747 Ref: library/signal module-contents6043890 Ref: 24826043890 Ref: library/signal signal SIG_DFL6044403 Ref: 21c46044403 Ref: library/signal signal SIG_IGN6044735 Ref: 21c56044735 Ref: library/signal signal SIGABRT6044856 Ref: 24876044856 Ref: library/signal signal SIGALRM6044922 Ref: 24886044922 Ref: library/signal signal SIGBREAK6045026 Ref: 24896045026 Ref: library/signal signal SIGBUS6045140 Ref: 248a6045140 Ref: library/signal signal SIGCHLD6045240 Ref: 247b6045240 Ref: library/signal signal SIGCLD6045347 Ref: 248b6045347 Ref: library/signal signal SIGCONT6045408 Ref: 1c9f6045408 Ref: library/signal signal SIGFPE6045526 Ref: 247e6045526 Ref: library/signal signal SIGHUP6045763 Ref: 248c6045763 Ref: library/signal signal SIGILL6045910 Ref: 248d6045910 Ref: library/signal signal SIGINT6045962 Ref: 21c36045962 Ref: library/signal signal SIGKILL6046092 Ref: 248e6046092 Ref: library/signal signal SIGPIPE6046223 Ref: 247a6046223 Ref: library/signal signal SIGSEGV6046383 Ref: 247f6046383 Ref: library/signal signal SIGTERM6046461 Ref: 22626046461 Ref: library/signal signal SIGUSR16046513 Ref: 248f6046513 Ref: library/signal signal SIGUSR26046606 Ref: 24906046606 Ref: library/signal signal SIGWINCH6046699 Ref: 24916046699 Ref: library/signal signal CTRL_C_EVENT6047355 Ref: 1c796047355 Ref: library/signal signal CTRL_BREAK_EVENT6047583 Ref: 1c7a6047583 Ref: library/signal signal NSIG6047819 Ref: 24926047819 Ref: library/signal signal ITIMER_REAL6047903 Ref: 24936047903 Ref: library/signal signal ITIMER_VIRTUAL6048035 Ref: 24946048035 Ref: library/signal signal ITIMER_PROF6048181 Ref: 24956048181 Ref: library/signal signal SIG_BLOCK6048520 Ref: 24836048520 Ref: library/signal signal SIG_UNBLOCK6048702 Ref: 24846048702 Ref: library/signal signal SIG_SETMASK6048893 Ref: 24856048893 Ref: library/signal signal ItimerError6049143 Ref: 24966049143 Ref: library/signal signal alarm6049666 Ref: 24996049666 Ref: library/signal signal getsignal6050309 Ref: 24866050309 Ref: library/signal signal strsignal6050881 Ref: 249a6050881 Ref: library/signal signal valid_signals6051139 Ref: 249b6051139 Ref: library/signal signal pause6051382 Ref: 249c6051382 Ref: library/signal signal raise_signal6051768 Ref: 249d6051768 Ref: library/signal signal pthread_kill6051901 Ref: a7a6051901 Ref: library/signal signal pthread_sigmask6053100 Ref: a796053100 Ref: library/signal signal setitimer6054519 Ref: 24976054519 Ref: library/signal signal getitimer6055537 Ref: 24986055537 Ref: library/signal signal set_wakeup_fd6055696 Ref: 3ce6055696 Ref: library/signal signal siginterrupt6057853 Ref: a7e6057853 Ref: library/signal signal signal6058456 Ref: a7d6058456 Ref: library/signal signal sigpending6059918 Ref: a7b6059918 Ref: library/signal signal sigwait6060376 Ref: a7c6060376 Ref: library/signal signal sigwaitinfo6060953 Ref: 67f6060953 Ref: library/signal signal sigtimedwait6062216 Ref: 67e6062216 Ref: Module contents<2>-Footnote-16062984 Ref: Module contents<2>-Footnote-26063033 Node: Example<9>6063082 Ref: library/signal example6063227 Ref: 249e6063227 Ref: library/signal signal-example6063227 Ref: 249f6063227 Node: Note on SIGPIPE6064126 Ref: library/signal note-on-sigpipe6064244 Ref: 24a06064244 Node: mmap — Memory-mapped file support6065658 Ref: library/mmap doc6065827 Ref: 24a16065827 Ref: library/mmap mmap-memory-mapped-file-support6065827 Ref: 24a26065827 Ref: library/mmap module-mmap6065827 Ref: b36065827 Ref: library/mmap mmap mmap6068263 Ref: 1ec6068263 Ref: library/mmap mmap mmap close6073278 Ref: 24a36073278 Ref: library/mmap mmap mmap closed6073489 Ref: 24a46073489 Ref: library/mmap mmap mmap find6073593 Ref: 24a56073593 Ref: library/mmap mmap mmap flush6074023 Ref: 2c36074023 Ref: library/mmap mmap mmap madvise6074911 Ref: 1ed6074911 Ref: library/mmap mmap mmap move6075477 Ref: 24a76075477 Ref: library/mmap mmap mmap read6075755 Ref: a226075755 Ref: library/mmap mmap mmap read_byte6076207 Ref: 24a86076207 Ref: library/mmap mmap mmap readline6076355 Ref: 24a96076355 Ref: library/mmap mmap mmap resize6076495 Ref: 24aa6076495 Ref: library/mmap mmap mmap rfind6076743 Ref: 24ab6076743 Ref: library/mmap mmap mmap seek6077175 Ref: 24ac6077175 Ref: library/mmap mmap mmap size6077561 Ref: 24ad6077561 Ref: library/mmap mmap mmap tell6077700 Ref: 24ae6077700 Ref: library/mmap mmap mmap write6077787 Ref: 24af6077787 Ref: library/mmap mmap mmap write_byte6078494 Ref: 24b06078494 Node: MADV_* Constants6078840 Ref: library/mmap madv-constants6078928 Ref: 24b16078928 Ref: library/mmap madvise-constants6078928 Ref: 24a66078928 Ref: library/mmap mmap MADV_NORMAL6078981 Ref: 24b26078981 Ref: library/mmap mmap MADV_RANDOM6079008 Ref: 24b36079008 Ref: library/mmap mmap MADV_SEQUENTIAL6079035 Ref: 24b46079035 Ref: library/mmap mmap MADV_WILLNEED6079066 Ref: 24b56079066 Ref: library/mmap mmap MADV_DONTNEED6079095 Ref: 24b66079095 Ref: library/mmap mmap MADV_REMOVE6079124 Ref: 24b76079124 Ref: library/mmap mmap MADV_DONTFORK6079151 Ref: 24b86079151 Ref: library/mmap mmap MADV_DOFORK6079180 Ref: 24b96079180 Ref: library/mmap mmap MADV_HWPOISON6079207 Ref: 24ba6079207 Ref: library/mmap mmap MADV_MERGEABLE6079236 Ref: 24bb6079236 Ref: library/mmap mmap MADV_UNMERGEABLE6079266 Ref: 24bc6079266 Ref: library/mmap mmap MADV_SOFT_OFFLINE6079298 Ref: 24bd6079298 Ref: library/mmap mmap MADV_HUGEPAGE6079331 Ref: 24be6079331 Ref: library/mmap mmap MADV_NOHUGEPAGE6079360 Ref: 24bf6079360 Ref: library/mmap mmap MADV_DONTDUMP6079391 Ref: 24c06079391 Ref: library/mmap mmap MADV_DODUMP6079420 Ref: 24c16079420 Ref: library/mmap mmap MADV_FREE6079447 Ref: 24c26079447 Ref: library/mmap mmap MADV_NOSYNC6079472 Ref: 24c36079472 Ref: library/mmap mmap MADV_AUTOSYNC6079499 Ref: 24c46079499 Ref: library/mmap mmap MADV_NOCORE6079528 Ref: 24c56079528 Ref: library/mmap mmap MADV_CORE6079555 Ref: 24c66079555 Ref: library/mmap mmap MADV_PROTECT6079580 Ref: 24c76079580 Node: Internet Data Handling6079815 Ref: library/netdata doc6079994 Ref: 24c86079994 Ref: library/netdata internet-data-handling6079994 Ref: 24c96079994 Ref: library/netdata netdata6079994 Ref: 24ca6079994 Node: email — An email and MIME handling package6080703 Ref: library/email doc6080848 Ref: 24cb6080848 Ref: library/email email-an-email-and-mime-handling-package6080848 Ref: 24cc6080848 Ref: library/email module-email6080848 Ref: 696080848 Ref: email — An email and MIME handling package-Footnote-16087608 Ref: email — An email and MIME handling package-Footnote-26087681 Ref: email — An email and MIME handling package-Footnote-36087730 Ref: email — An email and MIME handling package-Footnote-46087779 Ref: email — An email and MIME handling package-Footnote-56087828 Ref: email — An email and MIME handling package-Footnote-66087877 Ref: email — An email and MIME handling package-Footnote-76087926 Ref: email — An email and MIME handling package-Footnote-86087975 Ref: email — An email and MIME handling package-Footnote-96088024 Node: email message Representing an email message6088073 Ref: library/email message doc6088241 Ref: 24cd6088241 Ref: library/email message email-message-representing-an-email-message6088241 Ref: 24ce6088241 Ref: library/email message module-email message6088241 Ref: 726088241 Ref: library/email message email message EmailMessage6090729 Ref: 5426090729 Ref: library/email message email message EmailMessage as_string6091210 Ref: 24d16091210 Ref: library/email message email message EmailMessage __str__6093054 Ref: 24d26093054 Ref: library/email message email message EmailMessage as_bytes6093523 Ref: 24d36093523 Ref: library/email message email message EmailMessage __bytes__6094685 Ref: 24d46094685 Ref: library/email message email message EmailMessage is_multipart6094861 Ref: 24d56094861 Ref: library/email message email message EmailMessage set_unixfrom6095546 Ref: 24d66095546 Ref: library/email message email message EmailMessage get_unixfrom6095768 Ref: 24d86095768 Ref: library/email message email message EmailMessage __len__6096900 Ref: 24da6096900 Ref: library/email message email message EmailMessage __contains__6096998 Ref: 24db6096998 Ref: library/email message email message EmailMessage __getitem__6097388 Ref: 24dc6097388 Ref: library/email message email message EmailMessage __setitem__6098105 Ref: 24df6098105 Ref: library/email message email message EmailMessage __delitem__6099138 Ref: 24e06099138 Ref: library/email message email message EmailMessage keys6099364 Ref: 24d96099364 Ref: library/email message email message EmailMessage values6099458 Ref: 24e16099458 Ref: library/email message email message EmailMessage items6099548 Ref: 24e26099548 Ref: library/email message email message EmailMessage get6099679 Ref: 24e36099679 Ref: library/email message email message EmailMessage get_all6100028 Ref: 24dd6100028 Ref: library/email message email message EmailMessage add_header6100265 Ref: 24e46100265 Ref: library/email message email message EmailMessage replace_header6102229 Ref: 24e56102229 Ref: library/email message email message EmailMessage get_content_type6102535 Ref: 24e66102535 Ref: library/email message email message EmailMessage get_content_maintype6103419 Ref: 24e86103419 Ref: library/email message email message EmailMessage get_content_subtype6103625 Ref: 24e96103625 Ref: library/email message email message EmailMessage get_default_type6103818 Ref: 24e76103818 Ref: library/email message email message EmailMessage set_default_type6104138 Ref: 24ea6104138 Ref: library/email message email message EmailMessage set_param6104580 Ref: 24eb6104580 Ref: library/email message email message EmailMessage del_param6106194 Ref: 24ec6106194 Ref: library/email message email message EmailMessage get_filename6106630 Ref: 24ed6106630 Ref: library/email message email message EmailMessage get_boundary6107169 Ref: 24ef6107169 Ref: library/email message email message EmailMessage set_boundary6107533 Ref: 24f06107533 Ref: library/email message email message EmailMessage get_content_charset6108201 Ref: 24f26108201 Ref: library/email message email message EmailMessage get_charsets6108503 Ref: 24f36108503 Ref: library/email message email message EmailMessage is_attachment6109196 Ref: 24f46109196 Ref: library/email message email message EmailMessage get_content_disposition6109563 Ref: 24f66109563 Ref: library/email message email message EmailMessage walk6110038 Ref: 24f76110038 Ref: library/email message email message EmailMessage get_body6112051 Ref: 24f86112051 Ref: library/email message email message EmailMessage iter_attachments6114170 Ref: 24f96114170 Ref: library/email message email message EmailMessage iter_parts6115144 Ref: 24fa6115144 Ref: library/email message email message EmailMessage get_content6115357 Ref: 24fb6115357 Ref: library/email message email message EmailMessage set_content6115767 Ref: 24fd6115767 Ref: library/email message email message EmailMessage make_related6116177 Ref: 24ff6116177 Ref: library/email message email message EmailMessage make_alternative6116665 Ref: 25006116665 Ref: library/email message email message EmailMessage make_mixed6117184 Ref: 25016117184 Ref: library/email message email message EmailMessage add_related6117723 Ref: 25026117723 Ref: library/email message email message EmailMessage add_alternative6118480 Ref: 25046118480 Ref: library/email message email message EmailMessage add_attachment6119170 Ref: 25056119170 Ref: library/email message email message EmailMessage clear6120155 Ref: 25066120155 Ref: library/email message email message EmailMessage clear_content6120236 Ref: 25076120236 Ref: library/email message email message EmailMessage preamble6120496 Ref: 25086120496 Ref: library/email message email message EmailMessage epilogue6121758 Ref: 25096121758 Ref: library/email message email message EmailMessage defects6122104 Ref: 250a6122104 Ref: library/email message email message MIMEPart6122346 Ref: 8436122346 Ref: email message Representing an email message-Footnote-16122712 Ref: email message Representing an email message-Footnote-26122784 Ref: email message Representing an email message-Footnote-36122984 Ref: email message Representing an email message-Footnote-46123033 Ref: email message Representing an email message-Footnote-56123082 Ref: email message Representing an email message-Footnote-66123131 Ref: email message Representing an email message-Footnote-76123180 Ref: email message Representing an email message-Footnote-86123229 Ref: email message Representing an email message-Footnote-96123278 Ref: email message Representing an email message-Footnote-106123327 Ref: email message Representing an email message-Footnote-116123377 Ref: email message Representing an email message-Footnote-126123427 Ref: email message Representing an email message-Footnote-136123477 Node: email parser Parsing email messages6123527 Ref: library/email parser doc6123745 Ref: 250b6123745 Ref: library/email parser email-parser-parsing-email-messages6123745 Ref: 250c6123745 Ref: library/email parser module-email parser6123745 Ref: 746123745 Ref: email parser Parsing email messages-Footnote-16126130 Node: FeedParser API6126201 Ref: library/email parser feedparser-api6126306 Ref: 250e6126306 Ref: library/email parser email parser BytesFeedParser6127599 Ref: b496127599 Ref: library/email parser email parser BytesFeedParser feed6128798 Ref: 250f6128798 Ref: library/email parser email parser BytesFeedParser close6129233 Ref: 25106129233 Ref: library/email parser email parser FeedParser6129473 Ref: 250d6129473 Node: Parser API6129931 Ref: library/email parser parser-api6130061 Ref: 25116130061 Ref: library/email parser email parser BytesParser6130789 Ref: b4a6130789 Ref: library/email parser email parser BytesParser parse6131456 Ref: 25126131456 Ref: library/email parser email parser BytesParser parsebytes6132496 Ref: 25136132496 Ref: library/email parser email parser BytesHeaderParser6133002 Ref: 9fc6133002 Ref: library/email parser email parser Parser6133220 Ref: b186133220 Ref: library/email parser email parser Parser parse6133565 Ref: 25146133565 Ref: library/email parser email parser Parser parsestr6134003 Ref: 25156134003 Ref: library/email parser email parser HeaderParser6134432 Ref: 9fd6134432 Ref: library/email parser email message_from_bytes6134829 Ref: b476134829 Ref: library/email parser email message_from_binary_file6135296 Ref: b486135296 Ref: library/email parser email message_from_string6135769 Ref: 25166135769 Ref: library/email parser email message_from_file6136164 Ref: 25176136164 Ref: Parser API-Footnote-16136894 Ref: Parser API-Footnote-26136943 Node: Additional notes6136992 Ref: library/email parser additional-notes6137099 Ref: 25186137099 Node: email generator Generating MIME documents6138641 Ref: library/email generator doc6138843 Ref: 25196138843 Ref: library/email generator email-generator-generating-mime-documents6138843 Ref: 251a6138843 Ref: library/email generator module-email generator6138843 Ref: 6e6138843 Ref: library/email generator email generator BytesGenerator6140966 Ref: b4d6140966 Ref: library/email generator email generator BytesGenerator flatten6142872 Ref: 251b6142872 Ref: library/email generator email generator BytesGenerator clone6144694 Ref: 251e6144694 Ref: library/email generator email generator BytesGenerator write6144892 Ref: 251c6144892 Ref: library/email generator email generator Generator6145943 Ref: b4c6145943 Ref: library/email generator email generator Generator flatten6147789 Ref: 251f6147789 Ref: library/email generator email generator Generator clone6149549 Ref: 25216149549 Ref: library/email generator email generator Generator write6149734 Ref: 25206149734 Ref: library/email generator email generator DecodedGenerator6150643 Ref: 53e6150643 Ref: email generator Generating MIME documents-Footnote-16152060 Ref: email generator Generating MIME documents-Footnote-26152134 Ref: email generator Generating MIME documents-Footnote-36152627 Ref: email generator Generating MIME documents-Footnote-46152679 Ref: email generator Generating MIME documents-Footnote-56152728 Ref: email generator Generating MIME documents-Footnote-66152780 Node: email policy Policy Objects6152829 Ref: library/email policy doc6153037 Ref: 25226153037 Ref: library/email policy email-policy-policy-objects6153037 Ref: 25236153037 Ref: library/email policy module-email policy6153037 Ref: 756153037 Ref: library/email policy email policy Policy6158992 Ref: 9f46158992 Ref: library/email policy email policy Policy max_line_length6159812 Ref: 25246159812 Ref: library/email policy email policy Policy linesep6160118 Ref: 25256160118 Ref: library/email policy email policy Policy cte_type6160387 Ref: 251d6160387 Ref: library/email policy email policy Policy raise_on_defect6161498 Ref: 25276161498 Ref: library/email policy email policy Policy mangle_from_6161742 Ref: 6d06161742 Ref: library/email policy email policy Policy message_factory6162099 Ref: 53f6162099 Ref: library/email policy email policy Policy clone6162536 Ref: 9f66162536 Ref: library/email policy email policy Policy handle_defect6163010 Ref: 25296163010 Ref: library/email policy email policy Policy register_defect6163489 Ref: 25286163489 Ref: library/email policy email policy Policy header_max_count6164182 Ref: 252a6164182 Ref: library/email policy email policy Policy header_source_parse6165244 Ref: 252b6165244 Ref: library/email policy email policy Policy header_store_parse6166257 Ref: 252c6166257 Ref: library/email policy email policy Policy header_fetch_parse6167018 Ref: 252d6167018 Ref: library/email policy email policy Policy fold6167841 Ref: 252e6167841 Ref: library/email policy email policy Policy fold_binary6168557 Ref: 25266168557 Ref: library/email policy email policy EmailPolicy6168891 Ref: 9f86168891 Ref: library/email policy email policy EmailPolicy utf86169721 Ref: 6d26169721 Ref: library/email policy email policy EmailPolicy refold_source6170117 Ref: 252f6170117 Ref: library/email policy email policy EmailPolicy header_factory6170912 Ref: 25306170912 Ref: library/email policy email policy EmailPolicy content_manager6171523 Ref: 8446171523 Ref: library/email policy email policy EmailPolicy header_max_count6172232 Ref: 25326172232 Ref: library/email policy email policy EmailPolicy header_source_parse6172438 Ref: 25346172438 Ref: library/email policy email policy EmailPolicy header_store_parse6172823 Ref: 25356172823 Ref: library/email policy email policy EmailPolicy header_fetch_parse6173304 Ref: 25366173304 Ref: library/email policy email policy EmailPolicy fold6173730 Ref: 25376173730 Ref: library/email policy email policy EmailPolicy fold_binary6174893 Ref: 25386174893 Ref: library/email policy email policy default6175712 Ref: 24d06175712 Ref: library/email policy email policy SMTP6175922 Ref: 25396175922 Ref: library/email policy email policy SMTPUTF86176124 Ref: 253a6176124 Ref: library/email policy email policy HTTP6176538 Ref: 253b6176538 Ref: library/email policy email policy strict6176730 Ref: 253c6176730 Ref: library/email policy email policy Compat326178157 Ref: 9f56178157 Ref: library/email policy email policy Compat32 mangle_from_6178688 Ref: 253d6178688 Ref: library/email policy email policy Compat32 header_source_parse6178876 Ref: 253e6178876 Ref: library/email policy email policy Compat32 header_store_parse6179261 Ref: 253f6179261 Ref: library/email policy email policy Compat32 header_fetch_parse6179367 Ref: 25406179367 Ref: library/email policy email policy Compat32 fold6179609 Ref: 25426179609 Ref: library/email policy email policy Compat32 fold_binary6179952 Ref: 25436179952 Ref: library/email policy email policy compat326180482 Ref: 5406180482 Ref: email policy Policy Objects-Footnote-16180685 Ref: email policy Policy Objects-Footnote-26180756 Ref: email policy Policy Objects-Footnote-36180805 Ref: email policy Policy Objects-Footnote-46180854 Ref: email policy Policy Objects-Footnote-56180903 Ref: email policy Policy Objects-Footnote-66180952 Ref: email policy Policy Objects-Footnote-76181001 Ref: email policy Policy Objects-Footnote-86181050 Ref: email policy Policy Objects-Footnote-96181123 Ref: email policy Policy Objects-Footnote-106181172 Ref: email policy Policy Objects-Footnote-116181222 Ref: email policy Policy Objects-Footnote-126181272 Node: email errors Exception and Defect classes6181322 Ref: library/email errors doc6181531 Ref: 25446181531 Ref: library/email errors email-errors-exception-and-defect-classes6181531 Ref: 25456181531 Ref: library/email errors module-email errors6181531 Ref: 6d6181531 Ref: library/email errors email errors MessageError6181835 Ref: 25466181835 Ref: library/email errors email errors MessageParseError6182076 Ref: 25476182076 Ref: library/email errors email errors HeaderParseError6182352 Ref: 24f16182352 Ref: library/email errors email errors BoundaryError6182995 Ref: 25486182995 Ref: library/email errors email errors MultipartConversionError6183075 Ref: 25496183075 Ref: email errors Exception and Defect classes-Footnote-16186402 Ref: email errors Exception and Defect classes-Footnote-26186473 Node: email headerregistry Custom Header Objects6186522 Ref: library/email headerregistry doc6186746 Ref: 254c6186746 Ref: library/email headerregistry email-headerregistry-custom-header-objects6186746 Ref: 254d6186746 Ref: library/email headerregistry module-email headerregistry6186746 Ref: 706186746 Ref: library/email headerregistry email headerregistry BaseHeader6188512 Ref: 24de6188512 Ref: library/email headerregistry email headerregistry BaseHeader name6188825 Ref: 25506188825 Ref: library/email headerregistry email headerregistry BaseHeader defects6189076 Ref: 25516189076 Ref: library/email headerregistry email headerregistry BaseHeader max_count6189428 Ref: 25336189428 Ref: library/email headerregistry email headerregistry BaseHeader fold6189945 Ref: 25526189945 Ref: library/email headerregistry email headerregistry UnstructuredHeader6192136 Ref: 254f6192136 Ref: library/email headerregistry email headerregistry DateHeader6193215 Ref: 25536193215 Ref: library/email headerregistry email headerregistry DateHeader datetime6193578 Ref: 25546193578 Ref: library/email headerregistry email headerregistry AddressHeader6195146 Ref: 25556195146 Ref: library/email headerregistry email headerregistry AddressHeader groups6195430 Ref: 25566195430 Ref: library/email headerregistry email headerregistry AddressHeader addresses6195745 Ref: 25596195745 Ref: library/email headerregistry email headerregistry SingleAddressHeader6196907 Ref: 255b6196907 Ref: library/email headerregistry email headerregistry SingleAddressHeader address6197048 Ref: 255c6197048 Ref: library/email headerregistry email headerregistry MIMEVersionHeader6197580 Ref: 255d6197580 Ref: library/email headerregistry email headerregistry MIMEVersionHeader version6197972 Ref: 255e6197972 Ref: library/email headerregistry email headerregistry MIMEVersionHeader major6198099 Ref: 255f6198099 Ref: library/email headerregistry email headerregistry MIMEVersionHeader minor6198176 Ref: 25606198176 Ref: library/email headerregistry email headerregistry ParameterizedMIMEHeader6198253 Ref: 25616198253 Ref: library/email headerregistry email headerregistry ParameterizedMIMEHeader params6198636 Ref: 25626198636 Ref: library/email headerregistry email headerregistry ContentTypeHeader6198733 Ref: 25636198733 Ref: library/email headerregistry email headerregistry ContentTypeHeader content_type6198884 Ref: 25646198884 Ref: library/email headerregistry email headerregistry ContentTypeHeader maintype6198990 Ref: 25656198990 Ref: library/email headerregistry email headerregistry ContentTypeHeader subtype6199020 Ref: 25666199020 Ref: library/email headerregistry email headerregistry ContentDispositionHeader6199049 Ref: 25676199049 Ref: library/email headerregistry email headerregistry ContentDispositionHeader content_disposition6199214 Ref: 25686199214 Ref: library/email headerregistry email headerregistry ContentTransferEncoding6199351 Ref: 25696199351 Ref: library/email headerregistry email headerregistry ContentTransferEncoding cte6199466 Ref: 256a6199466 Ref: library/email headerregistry email headerregistry HeaderRegistry6199635 Ref: 254e6199635 Ref: library/email headerregistry email headerregistry HeaderRegistry map_to_type6201355 Ref: 256b6201355 Ref: library/email headerregistry email headerregistry HeaderRegistry __getitem__6201690 Ref: 256c6201690 Ref: library/email headerregistry email headerregistry HeaderRegistry __call__6201813 Ref: 256d6201813 Ref: library/email headerregistry email headerregistry Address6202455 Ref: 255a6202455 Ref: library/email headerregistry email headerregistry Address display_name6203294 Ref: 256e6203294 Ref: library/email headerregistry email headerregistry Address username6203520 Ref: 256f6203520 Ref: library/email headerregistry email headerregistry Address domain6203640 Ref: 25706203640 Ref: library/email headerregistry email headerregistry Address addr_spec6203720 Ref: 25716203720 Ref: library/email headerregistry email headerregistry Address __str__6203938 Ref: 25726203938 Ref: library/email headerregistry email headerregistry Group6204377 Ref: 25576204377 Ref: library/email headerregistry email headerregistry Group display_name6204926 Ref: 25586204926 Ref: library/email headerregistry email headerregistry Group addresses6205181 Ref: 25736205181 Ref: library/email headerregistry email headerregistry Group __str__6205329 Ref: 25746205329 Ref: email headerregistry Custom Header Objects-Footnote-16205769 Ref: email headerregistry Custom Header Objects-Footnote-26205849 Ref: email headerregistry Custom Header Objects-Footnote-36205921 Ref: email headerregistry Custom Header Objects-Footnote-46205970 Ref: email headerregistry Custom Header Objects-Footnote-56206019 Ref: email headerregistry Custom Header Objects-Footnote-66206068 Ref: email headerregistry Custom Header Objects-Footnote-76206117 Ref: email headerregistry Custom Header Objects-Footnote-86206166 Ref: email headerregistry Custom Header Objects-Footnote-96206215 Ref: email headerregistry Custom Header Objects-Footnote-106206264 Ref: email headerregistry Custom Header Objects-Footnote-116206314 Ref: email headerregistry Custom Header Objects-Footnote-126206364 Ref: email headerregistry Custom Header Objects-Footnote-136206414 Ref: email headerregistry Custom Header Objects-Footnote-146206464 Ref: email headerregistry Custom Header Objects-Footnote-156206514 Ref: email headerregistry Custom Header Objects-Footnote-166206564 Ref: email headerregistry Custom Header Objects-Footnote-176206614 Node: email contentmanager Managing MIME Content6206664 Ref: library/email contentmanager doc6206861 Ref: 25756206861 Ref: library/email contentmanager email-contentmanager-managing-mime-content6206861 Ref: 25766206861 Ref: library/email contentmanager module-email contentmanager6206861 Ref: 6b6206861 Ref: library/email contentmanager email contentmanager ContentManager6207118 Ref: 25776207118 Ref: library/email contentmanager email contentmanager ContentManager get_content6207407 Ref: 24fc6207407 Ref: library/email contentmanager email contentmanager ContentManager set_content6208261 Ref: 24fe6208261 Ref: library/email contentmanager email contentmanager ContentManager add_get_handler6209884 Ref: 25796209884 Ref: library/email contentmanager email contentmanager ContentManager add_set_handler6210076 Ref: 257b6210076 Ref: email contentmanager Managing MIME Content-Footnote-16210441 Ref: email contentmanager Managing MIME Content-Footnote-26210521 Node: Content Manager Instances6210593 Ref: library/email contentmanager content-manager-instances6210697 Ref: 257d6210697 Ref: library/email contentmanager email contentmanager raw_data_manager6211037 Ref: 25316211037 Ref: library/email contentmanager email contentmanager get_content6211767 Ref: 257a6211767 Ref: library/email contentmanager email contentmanager set_content6212366 Ref: 257c6212366 Ref: Content Manager Instances-Footnote-16216785 Node: email Examples6216834 Ref: library/email examples doc6217063 Ref: 257e6217063 Ref: library/email examples email-examples6217063 Ref: 8456217063 Ref: library/email examples id16217063 Ref: 257f6217063 Ref: email Examples-Footnote-16231728 Ref: email Examples-Footnote-26231776 Node: email message Message Representing an email message using the compat32 API6231862 Ref: library/email compat32-message doc6232104 Ref: 25806232104 Ref: library/email compat32-message compat32-message6232104 Ref: 24cf6232104 Ref: library/email compat32-message email-message-message-representing-an-email-message-using-the-compat32-api6232104 Ref: 25816232104 Ref: library/email compat32-message email message Message6234661 Ref: 5416234661 Ref: library/email compat32-message email message Message as_string6235194 Ref: 83f6235194 Ref: library/email compat32-message email message Message __str__6237342 Ref: 25826237342 Ref: library/email compat32-message email message Message as_bytes6237507 Ref: 8406237507 Ref: library/email compat32-message email message Message __bytes__6239063 Ref: 8416239063 Ref: library/email compat32-message email message Message is_multipart6239268 Ref: 24f56239268 Ref: library/email compat32-message email message Message set_unixfrom6239944 Ref: 25836239944 Ref: library/email compat32-message email message Message get_unixfrom6240084 Ref: 25846240084 Ref: library/email compat32-message email message Message attach6240241 Ref: 25036240241 Ref: library/email compat32-message email message Message get_payload6240859 Ref: b4b6240859 Ref: library/email compat32-message email message Message set_payload6243510 Ref: 25856243510 Ref: library/email compat32-message email message Message set_charset6243978 Ref: 25866243978 Ref: library/email compat32-message email message Message get_charset6245737 Ref: 25876245737 Ref: library/email compat32-message email message Message __len__6247189 Ref: 25896247189 Ref: library/email compat32-message email message Message __contains__6247287 Ref: 258a6247287 Ref: library/email compat32-message email message Message __getitem__6247657 Ref: 258b6247657 Ref: library/email compat32-message email message Message __setitem__6248192 Ref: 258d6248192 Ref: library/email compat32-message email message Message __delitem__6248749 Ref: 258e6248749 Ref: library/email compat32-message email message Message keys6248975 Ref: 25886248975 Ref: library/email compat32-message email message Message values6249069 Ref: 258f6249069 Ref: library/email compat32-message email message Message items6249159 Ref: 25906249159 Ref: library/email compat32-message email message Message get6249290 Ref: 25916249290 Ref: library/email compat32-message email message Message get_all6249614 Ref: 258c6249614 Ref: library/email compat32-message email message Message add_header6249851 Ref: 25926249851 Ref: library/email compat32-message email message Message replace_header6251817 Ref: 25936251817 Ref: library/email compat32-message email message Message get_content_type6252106 Ref: 25946252106 Ref: library/email compat32-message email message Message get_content_maintype6252964 Ref: 25966252964 Ref: library/email compat32-message email message Message get_content_subtype6253170 Ref: 25976253170 Ref: library/email compat32-message email message Message get_default_type6253363 Ref: 25956253363 Ref: library/email compat32-message email message Message set_default_type6253683 Ref: 25986253683 Ref: library/email compat32-message email message Message get_params6253970 Ref: 25996253970 Ref: library/email compat32-message email message Message get_param6255026 Ref: 259a6255026 Ref: library/email compat32-message email message Message set_param6257028 Ref: 8426257028 Ref: library/email compat32-message email message Message del_param6258295 Ref: 259c6258295 Ref: library/email compat32-message email message Message set_type6258736 Ref: 259d6258736 Ref: library/email compat32-message email message Message get_filename6259609 Ref: 259e6259609 Ref: library/email compat32-message email message Message get_boundary6260148 Ref: 259f6260148 Ref: library/email compat32-message email message Message set_boundary6260512 Ref: 25a06260512 Ref: library/email compat32-message email message Message get_content_charset6261327 Ref: 25a16261327 Ref: library/email compat32-message email message Message get_charsets6261815 Ref: 25a26261815 Ref: library/email compat32-message email message Message get_content_disposition6262517 Ref: 6d16262517 Ref: library/email compat32-message email message Message walk6262880 Ref: 25a36262880 Ref: library/email compat32-message email message Message preamble6265000 Ref: 25a46265000 Ref: library/email compat32-message email message Message epilogue6266262 Ref: 25a56266262 Ref: library/email compat32-message email message Message defects6266660 Ref: 25a66266660 Ref: email message Message Representing an email message using the compat32 API-Footnote-16266938 Ref: email message Message Representing an email message using the compat32 API-Footnote-26266987 Ref: email message Message Representing an email message using the compat32 API-Footnote-36267036 Ref: email message Message Representing an email message using the compat32 API-Footnote-46267085 Ref: email message Message Representing an email message using the compat32 API-Footnote-56267134 Ref: email message Message Representing an email message using the compat32 API-Footnote-66267183 Ref: email message Message Representing an email message using the compat32 API-Footnote-76267232 Ref: email message Message Representing an email message using the compat32 API-Footnote-86267281 Ref: email message Message Representing an email message using the compat32 API-Footnote-96267330 Ref: email message Message Representing an email message using the compat32 API-Footnote-106267379 Ref: email message Message Representing an email message using the compat32 API-Footnote-116267429 Ref: email message Message Representing an email message using the compat32 API-Footnote-126267479 Node: email mime Creating email and MIME objects from scratch6267529 Ref: library/email mime doc6267795 Ref: 25a76267795 Ref: library/email mime email-mime-creating-email-and-mime-objects-from-scratch6267795 Ref: 25a86267795 Ref: library/email mime module-email mime6267795 Ref: 736267795 Ref: library/email mime email mime base MIMEBase6269031 Ref: 25a96269031 Ref: library/email mime email mime nonmultipart MIMENonMultipart6270174 Ref: 254a6270174 Ref: library/email mime email mime multipart MIMEMultipart6270666 Ref: 25aa6270666 Ref: library/email mime email mime application MIMEApplication6271979 Ref: 25ab6271979 Ref: library/email mime email mime audio MIMEAudio6273321 Ref: 25ac6273321 Ref: library/email mime email mime image MIMEImage6274908 Ref: 254b6274908 Ref: library/email mime email mime message MIMEMessage6276506 Ref: 25ad6276506 Ref: library/email mime email mime text MIMEText6277190 Ref: 6d36277190 Ref: email mime Creating email and MIME objects from scratch-Footnote-16278828 Node: email header Internationalized headers6278895 Ref: library/email header doc6279128 Ref: 25ae6279128 Ref: library/email header email-header-internationalized-headers6279128 Ref: 25af6279128 Ref: library/email header module-email header6279128 Ref: 6f6279128 Ref: library/email header email header Header6281825 Ref: 25416281825 Ref: library/email header email header Header append6283697 Ref: 25b06283697 Ref: library/email header email header Header encode6285031 Ref: 25b16285031 Ref: library/email header email header Header __str__6286672 Ref: 25b26286672 Ref: library/email header email header Header __eq__6287171 Ref: 25b36287171 Ref: library/email header email header Header __ne__6287307 Ref: 25b46287307 Ref: library/email header email header decode_header6287531 Ref: 9f96287531 Ref: library/email header email header make_header6288187 Ref: 9fa6288187 Ref: email header Internationalized headers-Footnote-16288884 Ref: email header Internationalized headers-Footnote-26288955 Ref: email header Internationalized headers-Footnote-36289004 Ref: email header Internationalized headers-Footnote-46289052 Ref: email header Internationalized headers-Footnote-56289101 Ref: email header Internationalized headers-Footnote-66289150 Ref: email header Internationalized headers-Footnote-76289199 Ref: email header Internationalized headers-Footnote-86289248 Ref: email header Internationalized headers-Footnote-96289297 Ref: email header Internationalized headers-Footnote-106289346 Ref: email header Internationalized headers-Footnote-116289396 Ref: email header Internationalized headers-Footnote-126289446 Ref: email header Internationalized headers-Footnote-136289496 Ref: email header Internationalized headers-Footnote-146289546 Ref: email header Internationalized headers-Footnote-156289596 Node: email charset Representing character sets6289646 Ref: library/email charset doc6289847 Ref: 25b56289847 Ref: library/email charset email-charset-representing-character-sets6289847 Ref: 25b66289847 Ref: library/email charset module-email charset6289847 Ref: 6a6289847 Ref: library/email charset email charset Charset6290658 Ref: 6d46290658 Ref: library/email charset email charset Charset input_charset6292183 Ref: 25b76292183 Ref: library/email charset email charset Charset header_encoding6292439 Ref: 25b86292439 Ref: library/email charset email charset Charset body_encoding6292825 Ref: 25b96292825 Ref: library/email charset email charset Charset output_charset6293102 Ref: 25ba6293102 Ref: library/email charset email charset Charset input_codec6293441 Ref: 25bb6293441 Ref: library/email charset email charset Charset output_codec6293655 Ref: 25bc6293655 Ref: library/email charset email charset Charset get_body_encoding6293967 Ref: 25bd6293967 Ref: library/email charset email charset Charset get_output_charset6294684 Ref: 25be6294684 Ref: library/email charset email charset Charset header_encode6294888 Ref: 25bf6294888 Ref: library/email charset email charset Charset header_encode_lines6295096 Ref: 25c06295096 Ref: library/email charset email charset Charset body_encode6295529 Ref: 25c16295529 Ref: library/email charset email charset Charset __str__6295861 Ref: 25c26295861 Ref: library/email charset email charset Charset __eq__6296032 Ref: 25c36296032 Ref: library/email charset email charset Charset __ne__6296168 Ref: 25c46296168 Ref: library/email charset email charset add_charset6296462 Ref: 25c56296462 Ref: library/email charset email charset add_alias6297787 Ref: 25c76297787 Ref: library/email charset email charset add_codec6298113 Ref: 25c66298113 Ref: email charset Representing character sets-Footnote-16298507 Node: email encoders Encoders6298579 Ref: library/email encoders doc6298777 Ref: 25c86298777 Ref: library/email encoders email-encoders-encoders6298777 Ref: 25c96298777 Ref: library/email encoders module-email encoders6298777 Ref: 6c6298777 Ref: library/email encoders email encoders encode_quopri6300463 Ref: 25ca6300463 Ref: library/email encoders email encoders encode_base646300791 Ref: 25cb6300791 Ref: library/email encoders email encoders encode_7or8bit6301187 Ref: 25cc6301187 Ref: library/email encoders email encoders encode_noop6301447 Ref: 25cd6301447 Ref: email encoders Encoders-Footnote-16301627 Ref: email encoders Encoders-Footnote-26301700 Node: email utils Miscellaneous utilities6301821 Ref: library/email utils doc6302003 Ref: 25ce6302003 Ref: library/email utils email-utils-miscellaneous-utilities6302003 Ref: 25cf6302003 Ref: library/email utils module-email utils6302003 Ref: 766302003 Ref: library/email utils email utils localtime6302299 Ref: a006302299 Ref: library/email utils email utils make_msgid6303122 Ref: 25d06303122 Ref: library/email utils email utils quote6304019 Ref: 25d16304019 Ref: library/email utils email utils unquote6304198 Ref: 24ee6304198 Ref: library/email utils email utils parseaddr6304468 Ref: 25d26304468 Ref: library/email utils email utils formataddr6304827 Ref: b156304827 Ref: library/email utils email utils getaddresses6305508 Ref: 25d36305508 Ref: library/email utils email utils parsedate6306146 Ref: 25d46306146 Ref: library/email utils email utils parsedate_tz6306775 Ref: 25d56306775 Ref: library/email utils email utils parsedate_to_datetime6307354 Ref: 9ff6307354 Ref: library/email utils email utils mktime_tz6308065 Ref: 25d66308065 Ref: library/email utils email utils formatdate6308302 Ref: 25d76308302 Ref: library/email utils email utils format_datetime6309248 Ref: 9fe6309248 Ref: library/email utils email utils decode_rfc22316309936 Ref: 25d86309936 Ref: library/email utils email utils encode_rfc22316310036 Ref: 25d96310036 Ref: library/email utils email utils collapse_rfc2231_value6310444 Ref: 259b6310444 Ref: library/email utils email utils decode_params6311298 Ref: 25da6311298 Ref: email utils Miscellaneous utilities-Footnote-16311554 Ref: email utils Miscellaneous utilities-Footnote-26311624 Ref: email utils Miscellaneous utilities-Footnote-36311673 Ref: email utils Miscellaneous utilities-Footnote-46311722 Ref: email utils Miscellaneous utilities-Footnote-56311771 Ref: email utils Miscellaneous utilities-Footnote-66311820 Ref: email utils Miscellaneous utilities-Footnote-76312087 Ref: email utils Miscellaneous utilities-Footnote-86312136 Ref: email utils Miscellaneous utilities-Footnote-96312185 Ref: email utils Miscellaneous utilities-Footnote-106312234 Ref: email utils Miscellaneous utilities-Footnote-116312284 Ref: email utils Miscellaneous utilities-Footnote-126312334 Node: email iterators Iterators6312384 Ref: library/email iterators doc6312534 Ref: 25db6312534 Ref: library/email iterators email-iterators-iterators6312534 Ref: 25dc6312534 Ref: library/email iterators module-email iterators6312534 Ref: 716312534 Ref: library/email iterators email iterators body_line_iterator6312934 Ref: 25dd6312934 Ref: library/email iterators email iterators typed_subpart_iterator6313511 Ref: 25de6313511 Ref: library/email iterators email iterators _structure6314229 Ref: 25df6314229 Ref: email iterators Iterators-Footnote-16315809 Node: json — JSON encoder and decoder6315883 Ref: library/json doc6316070 Ref: 25e06316070 Ref: library/json json-json-encoder-and-decoder6316070 Ref: 25e16316070 Ref: library/json module-json6316070 Ref: a46316070 Ref: json — JSON encoder and decoder-Footnote-16320273 Ref: json — JSON encoder and decoder-Footnote-26320345 Ref: json — JSON encoder and decoder-Footnote-36320369 Ref: json — JSON encoder and decoder-Footnote-46320418 Ref: json — JSON encoder and decoder-Footnote-56320467 Ref: json — JSON encoder and decoder-Footnote-66320546 Ref: json — JSON encoder and decoder-Footnote-76320595 Ref: json — JSON encoder and decoder-Footnote-86320861 Node: Basic Usage6320886 Ref: library/json basic-usage6320997 Ref: 25e36320997 Ref: library/json json dump6321040 Ref: 6046321040 Ref: library/json json dumps6324573 Ref: 6056324573 Ref: library/json json load6325398 Ref: 55f6325398 Ref: library/json json loads6328010 Ref: 5606328010 Ref: Basic Usage-Footnote-16328930 Node: Encoders and Decoders6328961 Ref: library/json encoders-and-decoders6329095 Ref: 25e66329095 Ref: library/json json JSONDecoder6329158 Ref: 6076329158 Ref: library/json json-to-py-table6329412 Ref: 25e56329412 Ref: library/json json JSONDecoder decode6332312 Ref: 25e76332312 Ref: library/json json JSONDecoder raw_decode6332564 Ref: 25e86332564 Ref: library/json json JSONEncoder6332928 Ref: 6066332928 Ref: library/json py-to-json-table6333229 Ref: 25e46333229 Ref: library/json json JSONEncoder default6337537 Ref: 25e96337537 Ref: library/json json JSONEncoder encode6338226 Ref: 25ea6338226 Ref: library/json json JSONEncoder iterencode6338471 Ref: 25eb6338471 Node: Exceptions<13>6338732 Ref: library/json exceptions6338895 Ref: 25ec6338895 Ref: library/json json JSONDecodeError6338936 Ref: 7066338936 Ref: library/json json JSONDecodeError msg6339077 Ref: 25ed6339077 Ref: library/json json JSONDecodeError doc6339144 Ref: 25ee6339144 Ref: library/json json JSONDecodeError pos6339212 Ref: 25ef6339212 Ref: library/json json JSONDecodeError lineno6339295 Ref: 25f06339295 Ref: library/json json JSONDecodeError colno6339367 Ref: 25f16339367 Node: Standard Compliance and Interoperability6339466 Ref: library/json standard-compliance-and-interoperability6339633 Ref: 25f26339633 Ref: Standard Compliance and Interoperability-Footnote-16340783 Ref: Standard Compliance and Interoperability-Footnote-26340832 Node: Character Encodings6340911 Ref: library/json character-encodings6341046 Ref: 25f36341046 Node: Infinite and NaN Number Values6342377 Ref: library/json infinite-and-nan-number-values6342552 Ref: 25f46342552 Node: Repeated Names Within an Object6343340 Ref: library/json repeated-names-within-an-object6343533 Ref: 25f56343533 Node: Top-level Non-Object Non-Array Values6344056 Ref: library/json top-level-non-object-non-array-values6344245 Ref: 25f66344245 Ref: Top-level Non-Object Non-Array Values-Footnote-16344899 Ref: Top-level Non-Object Non-Array Values-Footnote-26344948 Node: Implementation Limitations6344997 Ref: library/json implementation-limitations6345146 Ref: 25f76345146 Node: Command Line Interface<2>6346096 Ref: library/json command-line-interface6346240 Ref: 25f86346240 Ref: library/json json-commandline6346240 Ref: 25e26346240 Ref: library/json module-json tool6346240 Ref: a56346240 Ref: Command Line Interface<2>-Footnote-16347168 Node: Command line options<2>6347236 Ref: library/json command-line-options6347321 Ref: 25fa6347321 Ref: library/json cmdoption-json-tool-arg-infile6347384 Ref: 25fb6347384 Ref: library/json cmdoption-json-tool-arg-outfile6347868 Ref: 25fc6347868 Ref: library/json cmdoption-json-tool-sort-keys6348011 Ref: 25f96348011 Ref: library/json cmdoption-json-tool-json-lines6348131 Ref: 25fd6348131 Ref: library/json cmdoption-json-tool-h6348245 Ref: 25fe6348245 Node: mailcap — Mailcap file handling6348306 Ref: library/mailcap doc6348500 Ref: 25ff6348500 Ref: library/mailcap mailcap-mailcap-file-handling6348500 Ref: 26006348500 Ref: library/mailcap module-mailcap6348500 Ref: af6348500 Ref: library/mailcap mailcap findmatch6349479 Ref: 26016349479 Ref: library/mailcap mailcap getcaps6351568 Ref: 26026351568 Ref: mailcap — Mailcap file handling-Footnote-16352408 Ref: mailcap — Mailcap file handling-Footnote-26352474 Ref: mailcap — Mailcap file handling-Footnote-36352523 Node: mailbox — Manipulate mailboxes in various formats6352572 Ref: library/mailbox doc6352774 Ref: 26036352774 Ref: library/mailbox mailbox-manipulate-mailboxes-in-various-formats6352774 Ref: 26046352774 Ref: library/mailbox module-mailbox6352774 Ref: ae6352774 Ref: mailbox — Manipulate mailboxes in various formats-Footnote-16353666 Node: Mailbox objects6353732 Ref: library/mailbox id16353859 Ref: 26056353859 Ref: library/mailbox mailbox-objects6353859 Ref: 26066353859 Ref: library/mailbox mailbox Mailbox6353918 Ref: be36353918 Ref: library/mailbox mailbox Mailbox add6356720 Ref: be26356720 Ref: library/mailbox mailbox Mailbox remove6357510 Ref: 26076357510 Ref: library/mailbox mailbox Mailbox __delitem__6357540 Ref: 260c6357540 Ref: library/mailbox mailbox Mailbox discard6357575 Ref: 26086357575 Ref: library/mailbox mailbox Mailbox __setitem__6358120 Ref: 260d6358120 Ref: library/mailbox mailbox Mailbox iterkeys6359003 Ref: 260e6359003 Ref: library/mailbox mailbox Mailbox keys6359032 Ref: 260f6359032 Ref: library/mailbox mailbox Mailbox itervalues6359217 Ref: 26106359217 Ref: library/mailbox mailbox Mailbox __iter__6359248 Ref: 26116359248 Ref: library/mailbox mailbox Mailbox values6359277 Ref: 26126359277 Ref: library/mailbox mailbox Mailbox iteritems6359916 Ref: 26136359916 Ref: library/mailbox mailbox Mailbox items6359946 Ref: 26146359946 Ref: library/mailbox mailbox Mailbox get6360469 Ref: 26156360469 Ref: library/mailbox mailbox Mailbox __getitem__6360510 Ref: 26166360510 Ref: library/mailbox mailbox Mailbox get_message6361096 Ref: 26176361096 Ref: library/mailbox mailbox Mailbox get_bytes6361384 Ref: be56361384 Ref: library/mailbox mailbox Mailbox get_string6361617 Ref: be66361617 Ref: library/mailbox mailbox Mailbox get_file6361956 Ref: be46361956 Ref: library/mailbox mailbox Mailbox __contains__6362931 Ref: 26186362931 Ref: library/mailbox mailbox Mailbox __len__6363065 Ref: 26196363065 Ref: library/mailbox mailbox Mailbox clear6363148 Ref: 261a6363148 Ref: library/mailbox mailbox Mailbox pop6363224 Ref: 261b6363224 Ref: library/mailbox mailbox Mailbox popitem6363667 Ref: 261c6363667 Ref: library/mailbox mailbox Mailbox update6364188 Ref: 261d6364188 Ref: library/mailbox mailbox Mailbox flush6364906 Ref: 261e6364906 Ref: library/mailbox mailbox Mailbox lock6365197 Ref: 26096365197 Ref: library/mailbox mailbox Mailbox unlock6365616 Ref: 260a6365616 Ref: library/mailbox mailbox Mailbox close6365696 Ref: 26206365696 Node: Maildir6365948 Ref: library/mailbox mailbox-maildir6366020 Ref: 26216366020 Ref: library/mailbox maildir6366020 Ref: 26226366020 Ref: library/mailbox mailbox Maildir6366063 Ref: ca86366063 Ref: library/mailbox mailbox Maildir list_folders6368912 Ref: 26246368912 Ref: library/mailbox mailbox Maildir get_folder6369000 Ref: 26256369000 Ref: library/mailbox mailbox Maildir add_folder6369240 Ref: 26276369240 Ref: library/mailbox mailbox Maildir remove_folder6369397 Ref: 26286369397 Ref: library/mailbox mailbox Maildir clean6369639 Ref: 262a6369639 Ref: library/mailbox mailbox Maildir add6369979 Ref: 262b6369979 Ref: library/mailbox mailbox Maildir __setitem__6370010 Ref: 262c6370010 Ref: library/mailbox mailbox Maildir update6370054 Ref: 262d6370054 Ref: library/mailbox mailbox Maildir flush6370467 Ref: 262e6370467 Ref: library/mailbox mailbox Maildir lock6370602 Ref: 262f6370602 Ref: library/mailbox mailbox Maildir unlock6370627 Ref: 26306370627 Ref: library/mailbox mailbox Maildir close6370760 Ref: 26316370760 Ref: library/mailbox mailbox Maildir get_file6370957 Ref: 26326370957 Ref: Maildir-Footnote-16371493 Ref: Maildir-Footnote-26371541 Node: mbox6371585 Ref: library/mailbox mailbox-mbox6371668 Ref: 26336371668 Ref: library/mailbox mbox6371668 Ref: 26346371668 Ref: library/mailbox mailbox mbox6371705 Ref: 260b6371705 Ref: library/mailbox mailbox mbox get_file6373141 Ref: 26356373141 Ref: library/mailbox mailbox mbox lock6373354 Ref: 26366373354 Ref: library/mailbox mailbox mbox unlock6373379 Ref: 26376373379 Ref: mbox-Footnote-16373956 Ref: mbox-Footnote-26374016 Ref: mbox-Footnote-36374068 Node: MH6374146 Ref: library/mailbox mailbox-mh6374227 Ref: 26386374227 Ref: library/mailbox mh6374227 Ref: 26396374227 Ref: library/mailbox mailbox MH6374260 Ref: 263a6374260 Ref: library/mailbox mailbox MH list_folders6375706 Ref: 263c6375706 Ref: library/mailbox mailbox MH get_folder6375794 Ref: 263d6375794 Ref: library/mailbox mailbox MH add_folder6376031 Ref: 263e6376031 Ref: library/mailbox mailbox MH remove_folder6376185 Ref: 263f6376185 Ref: library/mailbox mailbox MH get_sequences6376427 Ref: 26406376427 Ref: library/mailbox mailbox MH set_sequences6376604 Ref: 26416376604 Ref: library/mailbox mailbox MH pack6376842 Ref: 26426376842 Ref: library/mailbox mailbox MH remove6377263 Ref: 26436377263 Ref: library/mailbox mailbox MH __delitem__6377293 Ref: 26446377293 Ref: library/mailbox mailbox MH discard6377328 Ref: 26456377328 Ref: library/mailbox mailbox MH lock6377537 Ref: 26466377537 Ref: library/mailbox mailbox MH unlock6377562 Ref: 26476377562 Ref: library/mailbox mailbox MH get_file6377937 Ref: 26486377937 Ref: library/mailbox mailbox MH flush6378129 Ref: 26496378129 Ref: library/mailbox mailbox MH close6378259 Ref: 264a6378259 Ref: MH-Footnote-16378726 Ref: MH-Footnote-26378761 Node: Babyl6378806 Ref: library/mailbox babyl6378887 Ref: 264b6378887 Ref: library/mailbox mailbox-babyl6378887 Ref: 264c6378887 Ref: library/mailbox mailbox Babyl6378926 Ref: 264d6378926 Ref: library/mailbox mailbox Babyl get_labels6380495 Ref: 264f6380495 Ref: library/mailbox mailbox Babyl get_file6381028 Ref: 26506381028 Ref: library/mailbox mailbox Babyl lock6381548 Ref: 26516381548 Ref: library/mailbox mailbox Babyl unlock6381573 Ref: 26526381573 Ref: Babyl-Footnote-16381967 Ref: Babyl-Footnote-26382011 Node: MMDF6382089 Ref: library/mailbox mailbox-mmdf6382159 Ref: 26536382159 Ref: library/mailbox mmdf6382159 Ref: 26546382159 Ref: library/mailbox mailbox MMDF6382196 Ref: 26556382196 Ref: library/mailbox mailbox MMDF get_file6383459 Ref: 26576383459 Ref: library/mailbox mailbox MMDF lock6383672 Ref: 26586383672 Ref: library/mailbox mailbox MMDF unlock6383697 Ref: 26596383697 Ref: MMDF-Footnote-16384134 Ref: MMDF-Footnote-26384194 Node: Message objects6384237 Ref: library/mailbox mailbox-message-objects6384387 Ref: 265a6384387 Ref: library/mailbox message-objects6384387 Ref: 265b6384387 Ref: library/mailbox mailbox Message6384446 Ref: be76384446 Ref: Message objects-Footnote-16386492 Node: MaildirMessage6386541 Ref: library/mailbox mailbox-maildirmessage6386627 Ref: 265c6386627 Ref: library/mailbox maildirmessage6386627 Ref: 265d6386627 Ref: library/mailbox mailbox MaildirMessage6386684 Ref: 26236386684 Ref: library/mailbox mailbox MaildirMessage get_subdir6388540 Ref: 265e6388540 Ref: library/mailbox mailbox MaildirMessage set_subdir6389057 Ref: 265f6389057 Ref: library/mailbox mailbox MaildirMessage get_flags6389228 Ref: 26606389228 Ref: library/mailbox mailbox MaildirMessage set_flags6389700 Ref: 26616389700 Ref: library/mailbox mailbox MaildirMessage add_flag6389804 Ref: 26626389804 Ref: library/mailbox mailbox MaildirMessage remove_flag6390154 Ref: 26636390154 Ref: library/mailbox mailbox MaildirMessage get_date6390509 Ref: 26646390509 Ref: library/mailbox mailbox MaildirMessage set_date6390665 Ref: 26656390665 Ref: library/mailbox mailbox MaildirMessage get_info6390830 Ref: 26666390830 Ref: library/mailbox mailbox MaildirMessage set_info6391053 Ref: 26676391053 Node: mboxMessage6393871 Ref: library/mailbox mailbox-mboxmessage6393975 Ref: 26686393975 Ref: library/mailbox mboxmessage6393975 Ref: 26696393975 Ref: library/mailbox mailbox mboxMessage6394026 Ref: 24d76394026 Ref: library/mailbox mailbox mboxMessage get_from6395828 Ref: 266a6395828 Ref: library/mailbox mailbox mboxMessage set_from6396059 Ref: 266b6396059 Ref: library/mailbox mailbox mboxMessage get_flags6396595 Ref: 266c6396595 Ref: library/mailbox mailbox mboxMessage set_flags6396943 Ref: 266d6396943 Ref: library/mailbox mailbox mboxMessage add_flag6397234 Ref: 266e6397234 Ref: library/mailbox mailbox mboxMessage remove_flag6397454 Ref: 266f6397454 Node: MHMessage6400455 Ref: library/mailbox mailbox-mhmessage6400557 Ref: 26706400557 Ref: library/mailbox mhmessage6400557 Ref: 26716400557 Ref: library/mailbox mailbox MHMessage6400606 Ref: 263b6400606 Ref: library/mailbox mailbox MHMessage get_sequences6401572 Ref: 26726401572 Ref: library/mailbox mailbox MHMessage set_sequences6401695 Ref: 26736401695 Ref: library/mailbox mailbox MHMessage add_sequence6401803 Ref: 26746401803 Ref: library/mailbox mailbox MHMessage remove_sequence6401933 Ref: 26756401933 Node: BabylMessage6403819 Ref: library/mailbox babylmessage6403921 Ref: 26766403921 Ref: library/mailbox mailbox-babylmessage6403921 Ref: 26776403921 Ref: library/mailbox mailbox BabylMessage6403976 Ref: 264e6403976 Ref: library/mailbox mailbox BabylMessage get_labels6405344 Ref: 26786405344 Ref: library/mailbox mailbox BabylMessage set_labels6405427 Ref: 26796405427 Ref: library/mailbox mailbox BabylMessage add_label6405527 Ref: 267a6405527 Ref: library/mailbox mailbox BabylMessage remove_label6405624 Ref: 267b6405624 Ref: library/mailbox mailbox BabylMessage get_visible6405729 Ref: 267c6405729 Ref: library/mailbox mailbox BabylMessage set_visible6405897 Ref: 267d6405897 Ref: library/mailbox mailbox BabylMessage update_visible6406247 Ref: 267e6406247 Node: MMDFMessage6408715 Ref: library/mailbox mailbox-mmdfmessage6408799 Ref: 267f6408799 Ref: library/mailbox mmdfmessage6408799 Ref: 26806408799 Ref: library/mailbox mailbox MMDFMessage6408852 Ref: 26566408852 Ref: library/mailbox mailbox MMDFMessage get_from6410538 Ref: 26816410538 Ref: library/mailbox mailbox MMDFMessage set_from6410769 Ref: 26826410769 Ref: library/mailbox mailbox MMDFMessage get_flags6411305 Ref: 26836411305 Ref: library/mailbox mailbox MMDFMessage set_flags6411653 Ref: 26846411653 Ref: library/mailbox mailbox MMDFMessage add_flag6411944 Ref: 26856411944 Ref: library/mailbox mailbox MMDFMessage remove_flag6412164 Ref: 26866412164 Node: Exceptions<14>6415171 Ref: library/mailbox exceptions6415318 Ref: 26876415318 Ref: library/mailbox mailbox Error6415440 Ref: 26886415440 Ref: library/mailbox mailbox NoSuchMailboxError6415534 Ref: 26266415534 Ref: library/mailbox mailbox NotEmptyError6415840 Ref: 26296415840 Ref: library/mailbox mailbox ExternalClashError6416002 Ref: 261f6416002 Ref: library/mailbox mailbox FormatError6416315 Ref: 26896416315 Node: Examples<18>6416512 Ref: library/mailbox examples6416635 Ref: 268a6416635 Ref: library/mailbox mailbox-examples6416635 Ref: 268b6416635 Node: mimetypes — Map filenames to MIME types6418913 Ref: library/mimetypes doc6419135 Ref: 268c6419135 Ref: library/mimetypes mimetypes-map-filenames-to-mime-types6419135 Ref: 268d6419135 Ref: library/mimetypes module-mimetypes6419135 Ref: b26419135 Ref: library/mimetypes mimetypes guess_type6420022 Ref: 268f6420022 Ref: library/mimetypes mimetypes guess_all_extensions6421349 Ref: 26906421349 Ref: library/mimetypes mimetypes guess_extension6421914 Ref: 26916421914 Ref: library/mimetypes mimetypes init6422618 Ref: 268e6422618 Ref: library/mimetypes mimetypes read_mime_types6423594 Ref: 26936423594 Ref: library/mimetypes mimetypes add_type6423971 Ref: 26946423971 Ref: library/mimetypes mimetypes inited6424428 Ref: 26956424428 Ref: library/mimetypes mimetypes knownfiles6424598 Ref: 26926424598 Ref: library/mimetypes mimetypes suffix_map6424808 Ref: 26966424808 Ref: library/mimetypes mimetypes encodings_map6425158 Ref: 26976425158 Ref: library/mimetypes mimetypes types_map6425257 Ref: 26986425257 Ref: library/mimetypes mimetypes common_types6425348 Ref: 26996425348 Ref: mimetypes — Map filenames to MIME types-Footnote-16425890 Ref: mimetypes — Map filenames to MIME types-Footnote-26425958 Node: MimeTypes Objects6426029 Ref: library/mimetypes id16426124 Ref: 269a6426124 Ref: library/mimetypes mimetypes-objects6426124 Ref: 269b6426124 Ref: library/mimetypes mimetypes MimeTypes6426373 Ref: 269c6426373 Ref: library/mimetypes mimetypes MimeTypes suffix_map6427059 Ref: 269f6427059 Ref: library/mimetypes mimetypes MimeTypes encodings_map6427541 Ref: 26a06427541 Ref: library/mimetypes mimetypes MimeTypes types_map6427754 Ref: 26a16427754 Ref: library/mimetypes mimetypes MimeTypes types_map_inv6428090 Ref: 26a26428090 Ref: library/mimetypes mimetypes MimeTypes guess_extension6428440 Ref: 26a36428440 Ref: library/mimetypes mimetypes MimeTypes guess_type6428618 Ref: 26a46428618 Ref: library/mimetypes mimetypes MimeTypes guess_all_extensions6428785 Ref: 26a56428785 Ref: library/mimetypes mimetypes MimeTypes read6428973 Ref: 269d6428973 Ref: library/mimetypes mimetypes MimeTypes readfp6429286 Ref: 269e6429286 Ref: library/mimetypes mimetypes MimeTypes read_windows_registry6429617 Ref: 26a66429617 Node: base64 — Base16 Base32 Base64 Base85 Data Encodings6429958 Ref: library/base64 doc6430171 Ref: 26a76430171 Ref: library/base64 base64-base16-base32-base64-base85-data-encodings6430171 Ref: 26a86430171 Ref: library/base64 module-base646430171 Ref: e6430171 Ref: library/base64 base64 b64encode6432038 Ref: 26a96432038 Ref: library/base64 base64 b64decode6432588 Ref: 26aa6432588 Ref: library/base64 base64 standard_b64encode6433432 Ref: 26ab6433432 Ref: library/base64 base64 standard_b64decode6433605 Ref: 26ac6433605 Ref: library/base64 base64 urlsafe_b64encode6433794 Ref: 26ad6433794 Ref: library/base64 base64 urlsafe_b64decode6434134 Ref: 26ae6434134 Ref: library/base64 base64 b32encode6434451 Ref: 26af6434451 Ref: library/base64 base64 b32decode6434597 Ref: 95d6434597 Ref: library/base64 base64 b16encode6435587 Ref: 26b06435587 Ref: library/base64 base64 b16decode6435733 Ref: 26b16435733 Ref: library/base64 base64 a85encode6436216 Ref: 8246436216 Ref: library/base64 base64 a85decode6437179 Ref: 8256437179 Ref: library/base64 base64 b85encode6438042 Ref: 8266438042 Ref: library/base64 base64 b85decode6438394 Ref: 8276438394 Ref: library/base64 base64 decode6438658 Ref: 26b26438658 Ref: library/base64 base64 decodebytes6438966 Ref: 151e6438966 Ref: library/base64 base64 decodestring6439194 Ref: 26b36439194 Ref: library/base64 base64 encode6439322 Ref: 26b46439322 Ref: library/base64 base64 encodebytes6439841 Ref: 151d6439841 Ref: library/base64 base64 encodestring6440226 Ref: 26b56440226 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-16441034 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-26441099 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-36441148 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-46441197 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-56441246 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-66441295 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-76441344 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-86441393 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-96441442 Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-106441491 Node: binhex — Encode and decode binhex4 files6441541 Ref: library/binhex doc6441758 Ref: 26b66441758 Ref: library/binhex binhex-encode-and-decode-binhex4-files6441758 Ref: 26b76441758 Ref: library/binhex module-binhex6441758 Ref: 116441758 Ref: library/binhex binhex binhex6442180 Ref: 26b86442180 Ref: library/binhex binhex hexbin6442452 Ref: 26b96442452 Ref: library/binhex binhex Error6442850 Ref: 26ba6442850 Ref: binhex — Encode and decode binhex4 files-Footnote-16443287 Node: Notes<2>6443352 Ref: library/binhex binhex-notes6443439 Ref: 26bb6443439 Ref: library/binhex notes6443439 Ref: 26bc6443439 Node: binascii — Convert between binary and ASCII6443725 Ref: library/binascii doc6443944 Ref: 26bd6443944 Ref: library/binascii binascii-convert-between-binary-and-ascii6443944 Ref: 26be6443944 Ref: library/binascii module-binascii6443944 Ref: 106443944 Ref: library/binascii binascii a2b_uu6444982 Ref: 26bf6444982 Ref: library/binascii binascii b2a_uu6445232 Ref: 36d6445232 Ref: library/binascii binascii a2b_base646445611 Ref: 26c06445611 Ref: library/binascii binascii b2a_base646445785 Ref: 5236445785 Ref: library/binascii binascii a2b_qp6446135 Ref: 26c16446135 Ref: library/binascii binascii b2a_qp6446432 Ref: 26c26446432 Ref: library/binascii binascii a2b_hqx6447200 Ref: 26c36447200 Ref: library/binascii binascii rledecode_hqx6447488 Ref: 26c46447488 Ref: library/binascii binascii rlecode_hqx6448034 Ref: 26c66448034 Ref: library/binascii binascii b2a_hqx6448159 Ref: 26c76448159 Ref: library/binascii binascii crc_hqx6448404 Ref: 26c86448404 Ref: library/binascii binascii crc326448709 Ref: 26c96448709 Ref: library/binascii binascii b2a_hex6449500 Ref: 15206449500 Ref: library/binascii binascii hexlify6449564 Ref: 26ca6449564 Ref: library/binascii binascii a2b_hex6450761 Ref: 15216450761 Ref: library/binascii binascii unhexlify6450801 Ref: 26cb6450801 Ref: library/binascii binascii Error6451329 Ref: 95e6451329 Ref: library/binascii binascii Incomplete6451433 Ref: 26c56451433 Ref: binascii — Convert between binary and ASCII-Footnote-16452050 Ref: binascii — Convert between binary and ASCII-Footnote-26452099 Node: quopri — Encode and decode MIME quoted-printable data6452148 Ref: library/quopri doc6452364 Ref: 26cc6452364 Ref: library/quopri module-quopri6452364 Ref: db6452364 Ref: library/quopri quopri-encode-and-decode-mime-quoted-printable-data6452364 Ref: 26cd6452364 Ref: library/quopri quopri decode6453099 Ref: 15236453099 Ref: library/quopri quopri encode6453638 Ref: 15226453638 Ref: library/quopri quopri decodestring6454294 Ref: 26ce6454294 Ref: library/quopri quopri encodestring6454491 Ref: 26cf6454491 Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-16454941 Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-26455006 Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-36455055 Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-46455104 Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-56455153 Node: uu — Encode and decode uuencode files6455202 Ref: library/uu doc6455364 Ref: 26d06455364 Ref: library/uu module-uu6455364 Ref: 1236455364 Ref: library/uu uu-encode-and-decode-uuencode-files6455364 Ref: 26d16455364 Ref: library/uu uu encode6456313 Ref: 40f6456313 Ref: library/uu uu decode6456841 Ref: 15246456841 Ref: library/uu uu Error6457529 Ref: 26d26457529 Ref: uu — Encode and decode uuencode files-Footnote-16457946 Node: Structured Markup Processing Tools6458007 Ref: library/markup doc6458175 Ref: 26d36458175 Ref: library/markup markup6458175 Ref: 26d46458175 Ref: library/markup structured-markup-processing-tools6458175 Ref: 26d56458175 Node: html — HyperText Markup Language support6459718 Ref: library/html doc6459884 Ref: 26d66459884 Ref: library/html html-hypertext-markup-language-support6459884 Ref: 26d76459884 Ref: library/html module-html6459884 Ref: 906459884 Ref: library/html html escape6460150 Ref: 9346460150 Ref: library/html html unescape6460621 Ref: 85a6460621 Ref: html — HyperText Markup Language support-Footnote-16461322 Node: html parser — Simple HTML and XHTML parser6461394 Ref: library/html parser doc6461623 Ref: 26d86461623 Ref: library/html parser html-parser-simple-html-and-xhtml-parser6461623 Ref: 26d96461623 Ref: library/html parser module-html parser6461623 Ref: 926461623 Ref: library/html parser html parser HTMLParser6461999 Ref: 7bf6461999 Ref: html parser — Simple HTML and XHTML parser-Footnote-16463117 Node: Example HTML Parser Application6463187 Ref: library/html parser example-html-parser-application6463326 Ref: 26da6463326 Node: HTMLParser Methods6464532 Ref: library/html parser htmlparser-methods6464692 Ref: 26db6464692 Ref: library/html parser html parser HTMLParser feed6464819 Ref: 26dc6464819 Ref: library/html parser html parser HTMLParser close6465086 Ref: 26dd6465086 Ref: library/html parser html parser HTMLParser reset6465447 Ref: 26de6465447 Ref: library/html parser html parser HTMLParser getpos6465590 Ref: 26df6465590 Ref: library/html parser html parser HTMLParser get_starttag_text6465669 Ref: 26e06465669 Ref: library/html parser html parser HTMLParser handle_starttag6466240 Ref: 26e26466240 Ref: library/html parser html parser HTMLParser handle_endtag6467036 Ref: 26e36467036 Ref: library/html parser html parser HTMLParser handle_startendtag6467243 Ref: 26e16467243 Ref: library/html parser html parser HTMLParser handle_data6467656 Ref: 26e46467656 Ref: library/html parser html parser HTMLParser handle_entityref6467858 Ref: 26e56467858 Ref: library/html parser html parser HTMLParser handle_charref6468162 Ref: 26e66468162 Ref: library/html parser html parser HTMLParser handle_comment6468608 Ref: 26e76468608 Ref: library/html parser html parser HTMLParser handle_decl6469134 Ref: 26e86469134 Ref: library/html parser html parser HTMLParser handle_pi6469418 Ref: 26e96469418 Ref: library/html parser html parser HTMLParser unknown_decl6470108 Ref: 26ea6470108 Node: Examples<19>6470470 Ref: library/html parser examples6470590 Ref: 26eb6470590 Ref: library/html parser htmlparser-examples6470590 Ref: 26ec6470590 Node: html entities — Definitions of HTML general entities6473999 Ref: library/html entities doc6474208 Ref: 26ed6474208 Ref: library/html entities html-entities-definitions-of-html-general-entities6474208 Ref: 26ee6474208 Ref: library/html entities module-html entities6474208 Ref: 916474208 Ref: library/html entities html entities html56474589 Ref: a156474589 Ref: library/html entities html entities entitydefs6475074 Ref: 26f16475074 Ref: library/html entities html entities name2codepoint6475213 Ref: 26ef6475213 Ref: library/html entities html entities codepoint2name6475333 Ref: 26f06475333 Ref: html entities — Definitions of HTML general entities-Footnote-16475480 Ref: html entities — Definitions of HTML general entities-Footnote-26475552 Node: XML Processing Modules6475641 Ref: library/xml doc6475855 Ref: 26f26475855 Ref: library/xml module-xml6475855 Ref: 1336475855 Ref: library/xml xml6475855 Ref: 26f36475855 Ref: library/xml xml-processing-modules6475855 Ref: 26f46475855 Ref: XML Processing Modules-Footnote-16477315 Node: XML vulnerabilities6477375 Ref: library/xml id16477484 Ref: 26f76477484 Ref: library/xml xml-vulnerabilities6477484 Ref: 26f56477484 Ref: XML vulnerabilities-Footnote-16482146 Ref: XML vulnerabilities-Footnote-26482209 Ref: XML vulnerabilities-Footnote-36482262 Ref: XML vulnerabilities-Footnote-46482315 Ref: XML vulnerabilities-Footnote-56482378 Ref: XML vulnerabilities-Footnote-66482425 Node: The defusedxml Package6482470 Ref: library/xml defusedxml-package6482579 Ref: 26f66482579 Ref: library/xml the-defusedxml-package6482579 Ref: 26f86482579 Ref: The defusedxml Package-Footnote-16483035 Node: xml etree ElementTree — The ElementTree XML API6483080 Ref: library/xml etree elementtree doc6483281 Ref: 26f96483281 Ref: library/xml etree elementtree dtd6483281 Ref: 26fa6483281 Ref: library/xml etree elementtree module-xml etree ElementTree6483281 Ref: 1376483281 Ref: library/xml etree elementtree xml-etree-elementtree-the-elementtree-xml-api6483281 Ref: 26fb6483281 Ref: xml etree ElementTree — The ElementTree XML API-Footnote-16484153 Node: Tutorial6484234 Ref: library/xml etree elementtree tutorial6484350 Ref: 26fc6484350 Node: XML tree and elements6484801 Ref: library/xml etree elementtree xml-tree-and-elements6484887 Ref: 26fd6484887 Node: Parsing XML6485465 Ref: library/xml etree elementtree elementtree-parsing-xml6485593 Ref: 26fe6485593 Ref: library/xml etree elementtree parsing-xml6485593 Ref: 26ff6485593 Node: Pull API for non-blocking parsing6488049 Ref: library/xml etree elementtree elementtree-pull-parsing6488184 Ref: 9146488184 Ref: library/xml etree elementtree pull-api-for-non-blocking-parsing6488184 Ref: 27016488184 Node: Finding interesting elements6490081 Ref: library/xml etree elementtree finding-interesting-elements6490226 Ref: 27046490226 Node: Modifying an XML File6491467 Ref: library/xml etree elementtree modifying-an-xml-file6491601 Ref: 27096491601 Node: Building XML documents6494545 Ref: library/xml etree elementtree building-xml-documents6494678 Ref: 270d6494678 Node: Parsing XML with Namespaces6495047 Ref: library/xml etree elementtree parsing-xml-with-namespaces6495179 Ref: 270f6495179 Ref: Parsing XML with Namespaces-Footnote-16497494 Ref: Parsing XML with Namespaces-Footnote-26497546 Node: Additional resources6497598 Ref: library/xml etree elementtree additional-resources6497699 Ref: 27106497699 Node: XPath support6497851 Ref: library/xml etree elementtree elementtree-xpath6497988 Ref: 41a6497988 Ref: library/xml etree elementtree xpath-support6497988 Ref: 27116497988 Ref: XPath support-Footnote-16498352 Node: Example<10>6498388 Ref: library/xml etree elementtree example6498480 Ref: 27126498480 Node: Supported XPath syntax6499499 Ref: library/xml etree elementtree supported-xpath-syntax6499591 Ref: 27136499591 Node: Reference<2>6503552 Ref: library/xml etree elementtree reference6503697 Ref: 27146503697 Node: Functions<6>6503775 Ref: library/xml etree elementtree elementtree-functions6503836 Ref: 27156503836 Ref: library/xml etree elementtree functions6503836 Ref: 27166503836 Ref: library/xml etree elementtree xml etree ElementTree canonicalize6503877 Ref: 27176503877 Ref: library/xml etree elementtree xml etree ElementTree Comment6506259 Ref: 27186506259 Ref: library/xml etree elementtree xml etree ElementTree dump6506944 Ref: 27196506944 Ref: library/xml etree elementtree xml etree ElementTree fromstring6507418 Ref: 27006507418 Ref: library/xml etree elementtree xml etree ElementTree fromstringlist6507777 Ref: b4f6507777 Ref: library/xml etree elementtree xml etree ElementTree iselement6508195 Ref: 271b6508195 Ref: library/xml etree elementtree xml etree ElementTree iterparse6508409 Ref: 9486508409 Ref: library/xml etree elementtree xml etree ElementTree parse6510269 Ref: 271c6510269 Ref: library/xml etree elementtree xml etree ElementTree ProcessingInstruction6510613 Ref: 271d6510613 Ref: library/xml etree elementtree xml etree ElementTree register_namespace6511346 Ref: b506511346 Ref: library/xml etree elementtree xml etree ElementTree SubElement6511775 Ref: 270e6511775 Ref: library/xml etree elementtree xml etree ElementTree tostring6512345 Ref: 9156512345 Ref: library/xml etree elementtree xml etree ElementTree tostringlist6513424 Ref: 9166513424 Ref: library/xml etree elementtree xml etree ElementTree XML6514673 Ref: 271a6514673 Ref: library/xml etree elementtree xml etree ElementTree XMLID6515067 Ref: 271e6515067 Ref: Functions<6>-Footnote-16515542 Ref: Functions<6>-Footnote-26515583 Ref: Functions<6>-Footnote-36515896 Node: XInclude support6516209 Ref: library/xml etree elementtree elementtree-xinclude6516353 Ref: 271f6516353 Ref: library/xml etree elementtree xinclude-support6516353 Ref: 27206516353 Ref: XInclude support-Footnote-16516713 Node: Example<11>6516753 Ref: library/xml etree elementtree id36516817 Ref: 27216516817 Node: Reference<3>6518631 Ref: library/xml etree elementtree id46518754 Ref: 27226518754 Node: Functions<7>6518996 Ref: library/xml etree elementtree elementinclude-functions6519081 Ref: 27236519081 Ref: library/xml etree elementtree id56519081 Ref: 27246519081 Ref: library/xml etree elementtree xml etree ElementTree xml etree ElementInclude default_loader6519122 Ref: 27256519122 Ref: library/xml etree elementtree xml etree ElementTree xml etree ElementInclude include6519709 Ref: 27266519709 Node: Element Objects6520317 Ref: library/xml etree elementtree element-objects6520430 Ref: 27276520430 Ref: library/xml etree elementtree elementtree-element-objects6520430 Ref: 27286520430 Ref: library/xml etree elementtree xml etree ElementTree Element6520483 Ref: ac46520483 Ref: library/xml etree elementtree xml etree ElementTree Element tag6520965 Ref: 27296520965 Ref: library/xml etree elementtree xml etree ElementTree Element text6521110 Ref: 27076521110 Ref: library/xml etree elementtree xml etree ElementTree Element tail6521135 Ref: 272a6521135 Ref: library/xml etree elementtree xml etree ElementTree Element attrib6522250 Ref: 272b6522250 Ref: library/xml etree elementtree xml etree ElementTree Element clear6522794 Ref: 272c6522794 Ref: library/xml etree elementtree xml etree ElementTree Element get6522987 Ref: 27086522987 Ref: library/xml etree elementtree xml etree ElementTree Element items6523175 Ref: 272d6523175 Ref: library/xml etree elementtree xml etree ElementTree Element keys6523344 Ref: 272e6523344 Ref: library/xml etree elementtree xml etree ElementTree Element set6523486 Ref: 270a6523486 Ref: library/xml etree elementtree xml etree ElementTree Element append6523659 Ref: 270b6523659 Ref: library/xml etree elementtree xml etree ElementTree Element extend6523895 Ref: b516523895 Ref: library/xml etree elementtree xml etree ElementTree Element find6524145 Ref: 27066524145 Ref: library/xml etree elementtree xml etree ElementTree Element findall6524567 Ref: 27056524567 Ref: library/xml etree elementtree xml etree ElementTree Element findtext6524986 Ref: 272f6524986 Ref: library/xml etree elementtree xml etree ElementTree Element getchildren6525590 Ref: 27306525590 Ref: library/xml etree elementtree xml etree ElementTree Element getiterator6525741 Ref: 27316525741 Ref: library/xml etree elementtree xml etree ElementTree Element insert6525912 Ref: 27326525912 Ref: library/xml etree elementtree xml etree ElementTree Element iter6526123 Ref: ce76526123 Ref: library/xml etree elementtree xml etree ElementTree Element iterfind6526614 Ref: b526526614 Ref: library/xml etree elementtree xml etree ElementTree Element itertext6526946 Ref: b536526946 Ref: library/xml etree elementtree xml etree ElementTree Element makeelement6527169 Ref: 27336527169 Ref: library/xml etree elementtree xml etree ElementTree Element remove6527392 Ref: 270c6527392 Ref: Element Objects-Footnote-16529952 Node: ElementTree Objects6529995 Ref: library/xml etree elementtree elementtree-elementtree-objects6530109 Ref: 27346530109 Ref: library/xml etree elementtree elementtree-objects6530109 Ref: 27356530109 Ref: library/xml etree elementtree xml etree ElementTree ElementTree6530170 Ref: 9176530170 Ref: library/xml etree elementtree xml etree ElementTree ElementTree _setroot6530522 Ref: 27366530522 Ref: library/xml etree elementtree xml etree ElementTree ElementTree find6530771 Ref: 27376530771 Ref: library/xml etree elementtree xml etree ElementTree ElementTree findall6530910 Ref: 27386530910 Ref: library/xml etree elementtree xml etree ElementTree ElementTree findtext6531055 Ref: 27396531055 Ref: library/xml etree elementtree xml etree ElementTree ElementTree getiterator6531216 Ref: 273a6531216 Ref: library/xml etree elementtree xml etree ElementTree ElementTree getroot6531392 Ref: 273c6531392 Ref: library/xml etree elementtree xml etree ElementTree ElementTree iter6531472 Ref: 273b6531472 Ref: library/xml etree elementtree xml etree ElementTree ElementTree iterfind6531742 Ref: 273d6531742 Ref: library/xml etree elementtree xml etree ElementTree ElementTree parse6531919 Ref: 273e6531919 Ref: library/xml etree elementtree xml etree ElementTree ElementTree write6532264 Ref: 9186532264 Ref: ElementTree Objects-Footnote-16535033 Node: QName Objects6535346 Ref: library/xml etree elementtree elementtree-qname-objects6535464 Ref: 273f6535464 Ref: library/xml etree elementtree qname-objects6535464 Ref: 27406535464 Ref: library/xml etree elementtree xml etree ElementTree QName6535513 Ref: 27416535513 Node: TreeBuilder Objects6536026 Ref: library/xml etree elementtree elementtree-treebuilder-objects6536142 Ref: 27426536142 Ref: library/xml etree elementtree treebuilder-objects6536142 Ref: 27436536142 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder6536203 Ref: 2536536203 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder close6537321 Ref: 27446537321 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder data6537483 Ref: 27456537483 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder end6537647 Ref: b546537647 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder start6537780 Ref: 27466537780 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder comment6537982 Ref: 27476537982 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder pi6538178 Ref: 27486538178 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder doctype6538489 Ref: 2c16538489 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder start_ns6538813 Ref: 27496538813 Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder end_ns6539207 Ref: 274a6539207 Ref: library/xml etree elementtree xml etree ElementTree C14NWriterTarget6539454 Ref: 274b6539454 Ref: TreeBuilder Objects-Footnote-16540002 Node: XMLParser Objects6540043 Ref: library/xml etree elementtree elementtree-xmlparser-objects6540167 Ref: 274c6540167 Ref: library/xml etree elementtree xmlparser-objects6540167 Ref: 274d6540167 Ref: library/xml etree elementtree xml etree ElementTree XMLParser6540224 Ref: 2526540224 Ref: library/xml etree elementtree xml etree ElementTree XMLParser close6540936 Ref: 274f6540936 Ref: library/xml etree elementtree xml etree ElementTree XMLParser feed6541192 Ref: 274e6541192 Ref: XMLParser Objects-Footnote-16543069 Node: XMLPullParser Objects6543382 Ref: library/xml etree elementtree elementtree-xmlpullparser-objects6543501 Ref: 27506543501 Ref: library/xml etree elementtree xmlpullparser-objects6543501 Ref: 27516543501 Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser6543566 Ref: 9136543566 Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser feed6544258 Ref: 27026544258 Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser close6544340 Ref: 27526544340 Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser read_events6544651 Ref: 27036544651 Node: Exceptions<15>6546385 Ref: library/xml etree elementtree exceptions6546478 Ref: 27536546478 Ref: library/xml etree elementtree xml etree ElementTree ParseError6546521 Ref: c0c6546521 Ref: library/xml etree elementtree xml etree ElementTree ParseError code6546849 Ref: 27546546849 Ref: library/xml etree elementtree xml etree ElementTree ParseError position6547054 Ref: 27556547054 Node: xml dom — The Document Object Model API6547179 Ref: library/xml dom doc6547404 Ref: 27566547404 Ref: library/xml dom module-xml dom6547404 Ref: 1346547404 Ref: library/xml dom xml-dom-the-document-object-model-api6547404 Ref: 27576547404 Ref: xml dom — The Document Object Model API-Footnote-16550878 Ref: xml dom — The Document Object Model API-Footnote-26550954 Ref: xml dom — The Document Object Model API-Footnote-36551020 Ref: xml dom — The Document Object Model API-Footnote-46551067 Node: Module Contents<4>6551126 Ref: library/xml dom module-contents6551249 Ref: 275a6551249 Ref: library/xml dom xml dom registerDOMImplementation6551359 Ref: 275b6551359 Ref: library/xml dom xml dom getDOMImplementation6551807 Ref: 27586551807 Ref: library/xml dom xml dom EMPTY_NAMESPACE6552716 Ref: 275c6552716 Ref: library/xml dom xml dom XML_NAMESPACE6552989 Ref: 275d6552989 Ref: library/xml dom xml dom XMLNS_NAMESPACE6553146 Ref: 275e6553146 Ref: library/xml dom xml dom XHTML_NAMESPACE6553332 Ref: 275f6553332 Ref: Module Contents<4>-Footnote-16554067 Ref: Module Contents<4>-Footnote-26554112 Ref: Module Contents<4>-Footnote-36554169 Node: Objects in the DOM6554207 Ref: library/xml dom dom-objects6554350 Ref: 27606554350 Ref: library/xml dom objects-in-the-dom6554350 Ref: 27616554350 Node: DOMImplementation Objects6558885 Ref: library/xml dom dom-implementation-objects6558986 Ref: 27626558986 Ref: library/xml dom domimplementation-objects6558986 Ref: 276c6558986 Ref: library/xml dom xml dom DOMImplementation hasFeature6559342 Ref: 276d6559342 Ref: library/xml dom xml dom DOMImplementation createDocument6559521 Ref: 276e6559521 Ref: library/xml dom xml dom DOMImplementation createDocumentType6560041 Ref: 276f6560041 Node: Node Objects6560349 Ref: library/xml dom dom-node-objects6560475 Ref: 27636560475 Ref: library/xml dom node-objects6560475 Ref: 27706560475 Ref: library/xml dom xml dom Node nodeType6560592 Ref: 27716560592 Ref: library/xml dom xml dom Node parentNode6561015 Ref: 27726561015 Ref: library/xml dom xml dom Node attributes6561424 Ref: 27736561424 Ref: library/xml dom xml dom Node previousSibling6561637 Ref: 27746561637 Ref: library/xml dom xml dom Node nextSibling6562123 Ref: 27756562123 Ref: library/xml dom xml dom Node childNodes6562389 Ref: 27766562389 Ref: library/xml dom xml dom Node firstChild6562508 Ref: 27776562508 Ref: library/xml dom xml dom Node lastChild6562645 Ref: 27786562645 Ref: library/xml dom xml dom Node localName6562780 Ref: 27796562780 Ref: library/xml dom xml dom Node prefix6562944 Ref: 277a6562944 Ref: library/xml dom xml dom Node namespaceURI6563112 Ref: 277b6563112 Ref: library/xml dom xml dom Node nodeName6563275 Ref: 277c6563275 Ref: library/xml dom xml dom Node nodeValue6563712 Ref: 277d6563712 Ref: library/xml dom xml dom Node hasAttributes6563946 Ref: 277e6563946 Ref: library/xml dom xml dom Node hasChildNodes6564037 Ref: 277f6564037 Ref: library/xml dom xml dom Node isSameNode6564129 Ref: 27806564129 Ref: library/xml dom xml dom Node appendChild6564758 Ref: 27816564758 Ref: library/xml dom xml dom Node insertBefore6564966 Ref: 27826564966 Ref: library/xml dom xml dom Node removeChild6565307 Ref: 27836565307 Ref: library/xml dom xml dom Node replaceChild6565595 Ref: 27846565595 Ref: library/xml dom xml dom Node normalize6565809 Ref: 27856565809 Ref: library/xml dom xml dom Node cloneNode6566026 Ref: 27866566026 Node: NodeList Objects6566170 Ref: library/xml dom dom-nodelist-objects6566291 Ref: 27646566291 Ref: library/xml dom nodelist-objects6566291 Ref: 27876566291 Ref: library/xml dom xml dom NodeList item6566772 Ref: 27886566772 Ref: library/xml dom xml dom NodeList length6567002 Ref: 27896567002 Node: DocumentType Objects6567669 Ref: library/xml dom documenttype-objects6567794 Ref: 278a6567794 Ref: library/xml dom dom-documenttype-objects6567794 Ref: 27656567794 Ref: library/xml dom xml dom DocumentType publicId6568427 Ref: 278b6568427 Ref: library/xml dom xml dom DocumentType systemId6568593 Ref: 278c6568593 Ref: library/xml dom xml dom DocumentType internalSubset6568769 Ref: 278d6568769 Ref: library/xml dom xml dom DocumentType name6569022 Ref: 278e6569022 Ref: library/xml dom xml dom DocumentType entities6569151 Ref: 278f6569151 Ref: library/xml dom xml dom DocumentType notations6569534 Ref: 27906569534 Node: Document Objects6569913 Ref: library/xml dom document-objects6570040 Ref: 27916570040 Ref: library/xml dom dom-document-objects6570040 Ref: 27666570040 Ref: library/xml dom xml dom Document documentElement6570287 Ref: 27926570287 Ref: library/xml dom xml dom Document createElement6570381 Ref: 27936570381 Ref: library/xml dom xml dom Document createElementNS6570670 Ref: 27946570670 Ref: library/xml dom xml dom Document createTextNode6571021 Ref: 27956571021 Ref: library/xml dom xml dom Document createComment6571240 Ref: 27966571240 Ref: library/xml dom xml dom Document createProcessingInstruction6571461 Ref: 27976571461 Ref: library/xml dom xml dom Document createAttribute6571733 Ref: 27986571733 Ref: library/xml dom xml dom Document createAttributeNS6572040 Ref: 27996572040 Ref: library/xml dom xml dom Document getElementsByTagName6572428 Ref: 279a6572428 Ref: library/xml dom xml dom Document getElementsByTagNameNS6572604 Ref: 279b6572604 Node: Element Objects<2>6572875 Ref: library/xml dom dom-element-objects6572994 Ref: 27676572994 Ref: library/xml dom element-objects6572994 Ref: 279c6572994 Ref: library/xml dom xml dom Element tagName6573135 Ref: 279d6573135 Ref: library/xml dom xml dom Element getElementsByTagName6573282 Ref: 279e6573282 Ref: library/xml dom xml dom Element getElementsByTagNameNS6573395 Ref: 279f6573395 Ref: library/xml dom xml dom Element hasAttribute6573526 Ref: 27a06573526 Ref: library/xml dom xml dom Element hasAttributeNS6573640 Ref: 27a16573640 Ref: library/xml dom xml dom Element getAttribute6573804 Ref: 27a26573804 Ref: library/xml dom xml dom Element getAttributeNode6574017 Ref: 27a36574017 Ref: library/xml dom xml dom Element getAttributeNS6574138 Ref: 27a46574138 Ref: library/xml dom xml dom Element getAttributeNodeNS6574396 Ref: 27a56574396 Ref: library/xml dom xml dom Element removeAttribute6574550 Ref: 27a66574550 Ref: library/xml dom xml dom Element removeAttributeNode6574708 Ref: 27a86574708 Ref: library/xml dom xml dom Element removeAttributeNS6574900 Ref: 27a96574900 Ref: library/xml dom xml dom Element setAttribute6575109 Ref: 27aa6575109 Ref: library/xml dom xml dom Element setAttributeNode6575201 Ref: 27ab6575201 Ref: library/xml dom xml dom Element setAttributeNodeNS6575545 Ref: 27ad6575545 Ref: library/xml dom xml dom Element setAttributeNS6575918 Ref: 27ae6575918 Node: Attr Objects6576154 Ref: library/xml dom attr-objects6576277 Ref: 27af6576277 Ref: library/xml dom dom-attr-objects6576277 Ref: 27686576277 Ref: library/xml dom xml dom Attr name6576392 Ref: 27b06576392 Ref: library/xml dom xml dom Attr localName6576504 Ref: 27b16576504 Ref: library/xml dom xml dom Attr prefix6576658 Ref: 27b26576658 Ref: library/xml dom xml dom Attr value6576778 Ref: 27b36576778 Node: NamedNodeMap Objects6576903 Ref: library/xml dom dom-attributelist-objects6577023 Ref: 27b46577023 Ref: library/xml dom namednodemap-objects6577023 Ref: 27b56577023 Ref: library/xml dom xml dom NamedNodeMap length6577142 Ref: 27b66577142 Ref: library/xml dom xml dom NamedNodeMap item6577218 Ref: 27b76577218 Node: Comment Objects6577699 Ref: library/xml dom comment-objects6577836 Ref: 27b86577836 Ref: library/xml dom dom-comment-objects6577836 Ref: 27696577836 Ref: library/xml dom xml dom Comment data6578008 Ref: 27b96578008 Node: Text and CDATASection Objects6578226 Ref: library/xml dom dom-text-objects6578372 Ref: 276a6578372 Ref: library/xml dom text-and-cdatasection-objects6578372 Ref: 27ba6578372 Ref: library/xml dom xml dom Text data6578868 Ref: 27bb6578868 Node: ProcessingInstruction Objects6579361 Ref: library/xml dom dom-pi-objects6579506 Ref: 276b6579506 Ref: library/xml dom processinginstruction-objects6579506 Ref: 27bc6579506 Ref: library/xml dom xml dom ProcessingInstruction target6579718 Ref: 27bd6579718 Ref: library/xml dom xml dom ProcessingInstruction data6579886 Ref: 27be6579886 Node: Exceptions<16>6580024 Ref: library/xml dom dom-exceptions6580131 Ref: 27bf6580131 Ref: library/xml dom exceptions6580131 Ref: 27c06580131 Ref: library/xml dom xml dom DOMException6580810 Ref: 27c16580810 Ref: library/xml dom xml dom DomstringSizeErr6580972 Ref: 27c26580972 Ref: library/xml dom xml dom HierarchyRequestErr6581227 Ref: 27c36581227 Ref: library/xml dom xml dom IndexSizeErr6581366 Ref: 27c46581366 Ref: library/xml dom xml dom InuseAttributeErr6581508 Ref: 27ac6581508 Ref: library/xml dom xml dom InvalidAccessErr6581672 Ref: 27c56581672 Ref: library/xml dom xml dom InvalidCharacterErr6581805 Ref: 27c66581805 Ref: library/xml dom xml dom InvalidModificationErr6582165 Ref: 27c76582165 Ref: library/xml dom xml dom InvalidStateErr6582279 Ref: 27c86582279 Ref: library/xml dom xml dom NamespaceErr6582422 Ref: 27c96582422 Ref: library/xml dom xml dom NotFoundErr6582631 Ref: 27a76582631 Ref: library/xml dom xml dom NotSupportedErr6582862 Ref: 27ca6582862 Ref: library/xml dom xml dom NoDataAllowedErr6583004 Ref: 27cb6583004 Ref: library/xml dom xml dom NoModificationAllowedErr6583132 Ref: 27cc6583132 Ref: library/xml dom xml dom SyntaxErr6583298 Ref: 27cd6583298 Ref: library/xml dom xml dom WrongDocumentErr6583393 Ref: 27ce6583393 Ref: Exceptions<16>-Footnote-16586434 Node: Conformance6586479 Ref: library/xml dom conformance6586595 Ref: 27cf6586595 Ref: library/xml dom dom-conformance6586595 Ref: 27596586595 Node: Type Mapping6586852 Ref: library/xml dom dom-type-mapping6586937 Ref: 27d06586937 Ref: library/xml dom type-mapping6586937 Ref: 27d16586937 Node: Accessor Methods6587762 Ref: library/xml dom accessor-methods6587847 Ref: 27d26587847 Ref: library/xml dom dom-accessor-methods6587847 Ref: 27d36587847 Node: xml dom minidom — Minimal DOM implementation6589723 Ref: library/xml dom minidom doc6589957 Ref: 27d46589957 Ref: library/xml dom minidom module-xml dom minidom6589957 Ref: 1356589957 Ref: library/xml dom minidom xml-dom-minidom-minimal-dom-implementation6589957 Ref: 27d56589957 Ref: library/xml dom minidom xml dom minidom parse6591300 Ref: 27d66591300 Ref: library/xml dom minidom xml dom minidom parseString6591869 Ref: 27d76591869 Ref: xml dom minidom — Minimal DOM implementation-Footnote-16594447 Ref: xml dom minidom — Minimal DOM implementation-Footnote-26594521 Node: DOM Objects6594568 Ref: library/xml dom minidom dom-objects6594682 Ref: 27d86594682 Ref: library/xml dom minidom minidom-objects6594682 Ref: 27d96594682 Ref: library/xml dom minidom xml dom minidom Node unlink6594917 Ref: 27da6594917 Ref: library/xml dom minidom xml dom minidom Node writexml6595693 Ref: 27db6595693 Ref: library/xml dom minidom xml dom minidom Node toxml6596473 Ref: 27dc6596473 Ref: library/xml dom minidom xml dom minidom Node toprettyxml6597114 Ref: 27dd6597114 Ref: DOM Objects-Footnote-16597677 Node: DOM Example6598084 Ref: library/xml dom minidom dom-example6598235 Ref: 27de6598235 Ref: library/xml dom minidom id26598235 Ref: 27df6598235 Node: minidom and the DOM standard6600275 Ref: library/xml dom minidom minidom-and-dom6600406 Ref: 27e06600406 Ref: library/xml dom minidom minidom-and-the-dom-standard6600406 Ref: 27e16600406 Node: xml dom pulldom — Support for building partial DOM trees6603047 Ref: library/xml dom pulldom doc6603276 Ref: 27e26603276 Ref: library/xml dom pulldom module-xml dom pulldom6603276 Ref: 1366603276 Ref: library/xml dom pulldom xml-dom-pulldom-support-for-building-partial-dom-trees6603276 Ref: 27e36603276 Ref: library/xml dom pulldom xml dom pulldom PullDom6606031 Ref: 27e56606031 Ref: library/xml dom pulldom xml dom pulldom SAX2DOM6606152 Ref: 27e76606152 Ref: library/xml dom pulldom xml dom pulldom parse6606273 Ref: 27e86606273 Ref: library/xml dom pulldom xml dom pulldom parseString6606865 Ref: 27ea6606865 Ref: library/xml dom pulldom xml dom pulldom default_bufsize6607017 Ref: 27eb6607017 Ref: xml dom pulldom — Support for building partial DOM trees-Footnote-16607330 Node: DOMEventStream Objects6607404 Ref: library/xml dom pulldom domeventstream-objects6607521 Ref: 27ec6607521 Ref: library/xml dom pulldom id16607521 Ref: 27ed6607521 Ref: library/xml dom pulldom xml dom pulldom DOMEventStream6607586 Ref: 27d6607586 Ref: library/xml dom pulldom xml dom pulldom DOMEventStream getEvent6607753 Ref: 27ee6607753 Ref: library/xml dom pulldom xml dom pulldom DOMEventStream expandNode6608245 Ref: 27e46608245 Ref: library/xml dom pulldom xml dom pulldom DOMEventStream reset6608959 Ref: 27ef6608959 Node: xml sax — Support for SAX2 parsers6608986 Ref: library/xml sax doc6609218 Ref: 27f06609218 Ref: library/xml sax module-xml sax6609218 Ref: 13b6609218 Ref: library/xml sax xml-sax-support-for-sax2-parsers6609218 Ref: 27f16609218 Ref: library/xml sax xml sax make_parser6610309 Ref: 27f46610309 Ref: library/xml sax xml sax parse6610807 Ref: 27f56610807 Ref: library/xml sax xml sax parseString6611402 Ref: 7936611402 Ref: library/xml sax xml sax SAXException6613327 Ref: 27f96613327 Ref: library/xml sax xml sax SAXParseException6614199 Ref: 27f76614199 Ref: library/xml sax xml sax SAXNotRecognizedException6614610 Ref: 27fa6614610 Ref: library/xml sax xml sax SAXNotSupportedException6614912 Ref: 27fb6614912 Ref: xml sax — Support for SAX2 parsers-Footnote-16615926 Ref: xml sax — Support for SAX2 parsers-Footnote-26616002 Node: SAXException Objects6616037 Ref: library/xml sax sax-exception-objects6616130 Ref: 27fc6616130 Ref: library/xml sax saxexception-objects6616130 Ref: 27fd6616130 Ref: library/xml sax xml sax SAXException getMessage6616270 Ref: 27fe6616270 Ref: library/xml sax xml sax SAXException getException6616380 Ref: 27ff6616380 Node: xml sax handler — Base classes for SAX handlers6616484 Ref: library/xml sax handler doc6616692 Ref: 28006616692 Ref: library/xml sax handler module-xml sax handler6616692 Ref: 13c6616692 Ref: library/xml sax handler xml-sax-handler-base-classes-for-sax-handlers6616692 Ref: 28016616692 Ref: library/xml sax handler xml sax handler ContentHandler6617379 Ref: 27e66617379 Ref: library/xml sax handler xml sax handler DTDHandler6617619 Ref: 28026617619 Ref: library/xml sax handler xml sax handler EntityResolver6617804 Ref: 28036617804 Ref: library/xml sax handler xml sax handler ErrorHandler6618086 Ref: 27f66618086 Ref: library/xml sax handler xml sax handler feature_namespaces6618483 Ref: 28046618483 Ref: library/xml sax handler xml sax handler feature_namespace_prefixes6618811 Ref: 28056618811 Ref: library/xml sax handler xml sax handler feature_string_interning6619244 Ref: 28066619244 Ref: library/xml sax handler xml sax handler feature_validation6619663 Ref: 28076619663 Ref: library/xml sax handler xml sax handler feature_external_ges6620006 Ref: 27f36620006 Ref: library/xml sax handler xml sax handler feature_external_pes6620323 Ref: 28086620323 Ref: library/xml sax handler xml sax handler all_features6620708 Ref: 28096620708 Ref: library/xml sax handler xml sax handler property_lexical_handler6620776 Ref: 280a6620776 Ref: library/xml sax handler xml sax handler property_declaration_handler6621100 Ref: 280b6621100 Ref: library/xml sax handler xml sax handler property_dom_node6621462 Ref: 280c6621462 Ref: library/xml sax handler xml sax handler property_xml_string6621856 Ref: 280d6621856 Ref: library/xml sax handler xml sax handler all_properties6622129 Ref: 280e6622129 Ref: xml sax handler — Base classes for SAX handlers-Footnote-16622359 Node: ContentHandler Objects6622433 Ref: library/xml sax handler content-handler-objects6622568 Ref: 280f6622568 Ref: library/xml sax handler contenthandler-objects6622568 Ref: 28106622568 Ref: library/xml sax handler xml sax handler ContentHandler setDocumentLocator6622822 Ref: 28116622822 Ref: library/xml sax handler xml sax handler ContentHandler startDocument6623897 Ref: 28126623897 Ref: library/xml sax handler xml sax handler ContentHandler endDocument6624175 Ref: 28136624175 Ref: library/xml sax handler xml sax handler ContentHandler startPrefixMapping6624543 Ref: 28146624543 Ref: library/xml sax handler xml sax handler ContentHandler endPrefixMapping6625745 Ref: 28156625745 Ref: library/xml sax handler xml sax handler ContentHandler startElement6626088 Ref: 28166626088 Ref: library/xml sax handler xml sax handler ContentHandler endElement6626729 Ref: 28176626729 Ref: library/xml sax handler xml sax handler ContentHandler startElementNS6626957 Ref: 28196626957 Ref: library/xml sax handler xml sax handler ContentHandler endElementNS6627945 Ref: 281b6627945 Ref: library/xml sax handler xml sax handler ContentHandler characters6628218 Ref: 281c6628218 Ref: library/xml sax handler xml sax handler ContentHandler ignorableWhitespace6629245 Ref: 281d6629245 Ref: library/xml sax handler xml sax handler ContentHandler processingInstruction6629912 Ref: 281e6629912 Ref: library/xml sax handler xml sax handler ContentHandler skippedEntity6630372 Ref: 281f6630372 Node: DTDHandler Objects6630872 Ref: library/xml sax handler dtd-handler-objects6631038 Ref: 28206631038 Ref: library/xml sax handler dtdhandler-objects6631038 Ref: 28216631038 Ref: library/xml sax handler xml sax handler DTDHandler notationDecl6631163 Ref: 28226631163 Ref: library/xml sax handler xml sax handler DTDHandler unparsedEntityDecl6631270 Ref: 28236631270 Node: EntityResolver Objects6631408 Ref: library/xml sax handler entity-resolver-objects6631572 Ref: 28246631572 Ref: library/xml sax handler entityresolver-objects6631572 Ref: 28256631572 Ref: library/xml sax handler xml sax handler EntityResolver resolveEntity6631639 Ref: 28266631639 Node: ErrorHandler Objects6631907 Ref: library/xml sax handler errorhandler-objects6632044 Ref: 28276632044 Ref: library/xml sax handler sax-error-handler6632044 Ref: 28286632044 Ref: library/xml sax handler xml sax handler ErrorHandler error6632691 Ref: 28296632691 Ref: library/xml sax handler xml sax handler ErrorHandler fatalError6633060 Ref: 282a6633060 Ref: library/xml sax handler xml sax handler ErrorHandler warning6633246 Ref: 282b6633246 Node: xml sax saxutils — SAX Utilities6633591 Ref: library/xml sax utils doc6633810 Ref: 282c6633810 Ref: library/xml sax utils module-xml sax saxutils6633810 Ref: 13d6633810 Ref: library/xml sax utils xml-sax-saxutils-sax-utilities6633810 Ref: 282d6633810 Ref: library/xml sax utils xml sax saxutils escape6634197 Ref: 282e6634197 Ref: library/xml sax utils xml sax saxutils unescape6634651 Ref: 282f6634651 Ref: library/xml sax utils xml sax saxutils quoteattr6635118 Ref: 28306635118 Ref: library/xml sax utils xml sax saxutils XMLGenerator6636027 Ref: 28316636027 Ref: library/xml sax utils xml sax saxutils XMLFilterBase6636880 Ref: 28326636880 Ref: library/xml sax utils xml sax saxutils prepare_input_source6637302 Ref: 28336637302 Ref: xml sax saxutils — SAX Utilities-Footnote-16637791 Node: xml sax xmlreader — Interface for XML parsers6637867 Ref: library/xml sax reader doc6638087 Ref: 28346638087 Ref: library/xml sax reader module-xml sax xmlreader6638087 Ref: 13e6638087 Ref: library/xml sax reader xml-sax-xmlreader-interface-for-xml-parsers6638087 Ref: 28356638087 Ref: library/xml sax reader xml sax xmlreader XMLReader6638587 Ref: 27e96638587 Ref: library/xml sax reader xml sax xmlreader IncrementalParser6638683 Ref: 28366638683 Ref: library/xml sax reader xml sax xmlreader Locator6639810 Ref: 27f86639810 Ref: library/xml sax reader xml sax xmlreader InputSource6640143 Ref: 7926640143 Ref: library/xml sax reader xml sax xmlreader AttributesImpl6640911 Ref: 28386640911 Ref: library/xml sax reader xml sax xmlreader AttributesNSImpl6641510 Ref: 28396641510 Ref: xml sax xmlreader — Interface for XML parsers-Footnote-16642267 Node: XMLReader Objects6642344 Ref: library/xml sax reader id16642479 Ref: 283a6642479 Ref: library/xml sax reader xmlreader-objects6642479 Ref: 283b6642479 Ref: library/xml sax reader xml sax xmlreader XMLReader parse6642606 Ref: 28376642606 Ref: library/xml sax reader xml sax xmlreader XMLReader getContentHandler6643195 Ref: 283c6643195 Ref: library/xml sax reader xml sax xmlreader XMLReader setContentHandler6643292 Ref: 283d6643292 Ref: library/xml sax reader xml sax xmlreader XMLReader getDTDHandler6643475 Ref: 283e6643475 Ref: library/xml sax reader xml sax xmlreader XMLReader setDTDHandler6643564 Ref: 283f6643564 Ref: library/xml sax reader xml sax xmlreader XMLReader getEntityResolver6643731 Ref: 28406643731 Ref: library/xml sax reader xml sax xmlreader XMLReader setEntityResolver6643828 Ref: 28416643828 Ref: library/xml sax reader xml sax xmlreader XMLReader getErrorHandler6644120 Ref: 28426644120 Ref: library/xml sax reader xml sax xmlreader XMLReader setErrorHandler6644213 Ref: 28436644213 Ref: library/xml sax reader xml sax xmlreader XMLReader setLocale6644417 Ref: 28446644417 Ref: library/xml sax reader xml sax xmlreader XMLReader getFeature6644783 Ref: 28456644783 Ref: library/xml sax reader xml sax xmlreader XMLReader setFeature6645065 Ref: 27f26645065 Ref: library/xml sax reader xml sax xmlreader XMLReader getProperty6645354 Ref: 28466645354 Ref: library/xml sax reader xml sax xmlreader XMLReader setProperty6645645 Ref: 28476645645 Node: IncrementalParser Objects6645939 Ref: library/xml sax reader incremental-parser-objects6646098 Ref: 28486646098 Ref: library/xml sax reader incrementalparser-objects6646098 Ref: 28496646098 Ref: library/xml sax reader xml sax xmlreader IncrementalParser feed6646256 Ref: 284a6646256 Ref: library/xml sax reader xml sax xmlreader IncrementalParser close6646332 Ref: 284b6646332 Ref: library/xml sax reader xml sax xmlreader IncrementalParser reset6646571 Ref: 284c6646571 Node: Locator Objects6646833 Ref: library/xml sax reader id26646994 Ref: 284d6646994 Ref: library/xml sax reader locator-objects6646994 Ref: 284e6646994 Ref: library/xml sax reader xml sax xmlreader Locator getColumnNumber6647105 Ref: 284f6647105 Ref: library/xml sax reader xml sax xmlreader Locator getLineNumber6647208 Ref: 28506647208 Ref: library/xml sax reader xml sax xmlreader Locator getPublicId6647307 Ref: 28516647307 Ref: library/xml sax reader xml sax xmlreader Locator getSystemId6647401 Ref: 28526647401 Node: InputSource Objects6647495 Ref: library/xml sax reader input-source-objects6647655 Ref: 28536647655 Ref: library/xml sax reader inputsource-objects6647655 Ref: 28546647655 Ref: library/xml sax reader xml sax xmlreader InputSource setPublicId6647716 Ref: 28556647716 Ref: library/xml sax reader xml sax xmlreader InputSource getPublicId6647823 Ref: 28566647823 Ref: library/xml sax reader xml sax xmlreader InputSource setSystemId6647931 Ref: 28576647931 Ref: library/xml sax reader xml sax xmlreader InputSource getSystemId6648038 Ref: 28586648038 Ref: library/xml sax reader xml sax xmlreader InputSource setEncoding6648146 Ref: 28596648146 Ref: library/xml sax reader xml sax xmlreader InputSource getEncoding6648532 Ref: 285a6648532 Ref: library/xml sax reader xml sax xmlreader InputSource setByteStream6648626 Ref: 285b6648626 Ref: library/xml sax reader xml sax xmlreader InputSource getByteStream6649059 Ref: 285c6649059 Ref: library/xml sax reader xml sax xmlreader InputSource setCharacterStream6649267 Ref: 285d6649267 Ref: library/xml sax reader xml sax xmlreader InputSource getCharacterStream6649580 Ref: 285e6649580 Node: The Attributes Interface6649681 Ref: library/xml sax reader attributes-objects6649852 Ref: 28186649852 Ref: library/xml sax reader the-attributes-interface6649852 Ref: 285f6649852 Ref: library/xml sax reader xml sax xmlreader Attributes getLength6650180 Ref: 28606650180 Ref: library/xml sax reader xml sax xmlreader Attributes getNames6650256 Ref: 28616650256 Ref: library/xml sax reader xml sax xmlreader Attributes getType6650334 Ref: 28626650334 Ref: library/xml sax reader xml sax xmlreader Attributes getValue6650459 Ref: 28636650459 Node: The AttributesNS Interface6650543 Ref: library/xml sax reader attributes-ns-objects6650686 Ref: 281a6650686 Ref: library/xml sax reader the-attributesns-interface6650686 Ref: 28646650686 Ref: library/xml sax reader xml sax xmlreader AttributesNS getValueByQName6651019 Ref: 28656651019 Ref: library/xml sax reader xml sax xmlreader AttributesNS getNameByQName6651113 Ref: 28666651113 Ref: library/xml sax reader xml sax xmlreader AttributesNS getQNameByName6651236 Ref: 28676651236 Ref: library/xml sax reader xml sax xmlreader AttributesNS getQNames6651357 Ref: 28686651357 Node: xml parsers expat — Fast XML parsing using Expat6651448 Ref: library/pyexpat doc6651625 Ref: 28696651625 Ref: library/pyexpat module-xml parsers expat6651625 Ref: 1386651625 Ref: library/pyexpat xml-parsers-expat-fast-xml-parsing-using-expat6651625 Ref: 286a6651625 Ref: library/pyexpat xml parsers expat ExpatError6652679 Ref: c0d6652679 Ref: library/pyexpat xml parsers expat error6652889 Ref: 286c6652889 Ref: library/pyexpat xml parsers expat XMLParserType6652968 Ref: 286d6652968 Ref: library/pyexpat xml parsers expat ErrorString6653165 Ref: 286f6653165 Ref: library/pyexpat xml parsers expat ParserCreate6653288 Ref: 286e6653288 Ref: xml parsers expat — Fast XML parsing using Expat-Footnote-16655724 Ref: xml parsers expat — Fast XML parsing using Expat-Footnote-26656037 Node: XMLParser Objects<2>6656070 Ref: library/pyexpat id26656207 Ref: 28706656207 Ref: library/pyexpat xmlparser-objects6656207 Ref: 28716656207 Ref: library/pyexpat xml parsers expat xmlparser Parse6656317 Ref: 28726656317 Ref: library/pyexpat xml parsers expat xmlparser ParseFile6656695 Ref: 28736656695 Ref: library/pyexpat xml parsers expat xmlparser SetBase6656915 Ref: 28746656915 Ref: library/pyexpat xml parsers expat xmlparser GetBase6657331 Ref: 28786657331 Ref: library/pyexpat xml parsers expat xmlparser GetInputContext6657529 Ref: 28796657529 Ref: library/pyexpat xml parsers expat xmlparser ExternalEntityParserCreate6657812 Ref: 287a6657812 Ref: library/pyexpat xml parsers expat xmlparser SetParamEntityParsing6658329 Ref: 287d6658329 Ref: library/pyexpat xml parsers expat xmlparser UseForeignDTD6658694 Ref: 287e6658694 Ref: library/pyexpat xml parsers expat xmlparser buffer_size6659736 Ref: 28816659736 Ref: library/pyexpat xml parsers expat xmlparser buffer_text6659998 Ref: 28826659998 Ref: library/pyexpat xml parsers expat xmlparser buffer_used6660450 Ref: 28846660450 Ref: library/pyexpat xml parsers expat xmlparser ordered_attributes6660723 Ref: 287b6660723 Ref: library/pyexpat xml parsers expat xmlparser specified_attributes6661215 Ref: 287c6661215 Ref: library/pyexpat xml parsers expat xmlparser ErrorByteIndex6662021 Ref: 28856662021 Ref: library/pyexpat xml parsers expat xmlparser ErrorCode6662107 Ref: 28866662107 Ref: library/pyexpat xml parsers expat xmlparser ErrorColumnNumber6662338 Ref: 28876662338 Ref: library/pyexpat xml parsers expat xmlparser ErrorLineNumber6662430 Ref: 28886662430 Ref: library/pyexpat xml parsers expat xmlparser CurrentByteIndex6662923 Ref: 28896662923 Ref: library/pyexpat xml parsers expat xmlparser CurrentColumnNumber6663012 Ref: 288a6663012 Ref: library/pyexpat xml parsers expat xmlparser CurrentLineNumber6663107 Ref: 288b6663107 Ref: library/pyexpat xml parsers expat xmlparser XmlDeclHandler6663520 Ref: 288c6663520 Ref: library/pyexpat xml parsers expat xmlparser StartDoctypeDeclHandler6664133 Ref: 287f6664133 Ref: library/pyexpat xml parsers expat xmlparser EndDoctypeDeclHandler6664686 Ref: 28806664686 Ref: library/pyexpat xml parsers expat xmlparser ElementDeclHandler6664852 Ref: 288d6664852 Ref: library/pyexpat xml parsers expat xmlparser AttlistDeclHandler6665066 Ref: 288e6665066 Ref: library/pyexpat xml parsers expat xmlparser StartElementHandler6665969 Ref: 288f6665969 Ref: library/pyexpat xml parsers expat xmlparser EndElementHandler6666366 Ref: 28906666366 Ref: library/pyexpat xml parsers expat xmlparser ProcessingInstructionHandler6666457 Ref: 28916666457 Ref: library/pyexpat xml parsers expat xmlparser CharacterDataHandler6666571 Ref: 28836666571 Ref: library/pyexpat xml parsers expat xmlparser UnparsedEntityDeclHandler6666993 Ref: 28776666993 Ref: library/pyexpat xml parsers expat xmlparser EntityDeclHandler6667386 Ref: 28946667386 Ref: library/pyexpat xml parsers expat xmlparser NotationDeclHandler6668131 Ref: 28766668131 Ref: library/pyexpat xml parsers expat xmlparser StartNamespaceDeclHandler6668422 Ref: 28956668422 Ref: library/pyexpat xml parsers expat xmlparser EndNamespaceDeclHandler6668700 Ref: 28966668700 Ref: library/pyexpat xml parsers expat xmlparser CommentHandler6669223 Ref: 28976669223 Ref: library/pyexpat xml parsers expat xmlparser StartCdataSectionHandler6669409 Ref: 28926669409 Ref: library/pyexpat xml parsers expat xmlparser EndCdataSectionHandler6669646 Ref: 28936669646 Ref: library/pyexpat xml parsers expat xmlparser DefaultHandler6669739 Ref: 28986669739 Ref: library/pyexpat xml parsers expat xmlparser DefaultHandlerExpand6670024 Ref: 28996670024 Ref: library/pyexpat xml parsers expat xmlparser NotStandaloneHandler6670264 Ref: 289a6670264 Ref: library/pyexpat xml parsers expat xmlparser ExternalEntityRefHandler6670786 Ref: 28756670786 Node: ExpatError Exceptions6671842 Ref: library/pyexpat expaterror-exceptions6671999 Ref: 289b6671999 Ref: library/pyexpat expaterror-objects6671999 Ref: 286b6671999 Ref: library/pyexpat xml parsers expat ExpatError code6672140 Ref: 289c6672140 Ref: library/pyexpat xml parsers expat ExpatError lineno6672789 Ref: 289f6672789 Ref: library/pyexpat xml parsers expat ExpatError offset6672916 Ref: 28a06672916 Node: Example<12>6673057 Ref: library/pyexpat example6673220 Ref: 28a16673220 Ref: library/pyexpat expat-example6673220 Ref: 28a26673220 Node: Content Model Descriptions6674318 Ref: library/pyexpat content-model-descriptions6674481 Ref: 28a36674481 Ref: library/pyexpat expat-content-models6674481 Ref: 28a46674481 Ref: library/pyexpat module-xml parsers expat model6674481 Ref: 13a6674481 Node: Expat error constants6676324 Ref: library/pyexpat expat-error-constants6676467 Ref: 28a56676467 Ref: library/pyexpat expat-errors6676467 Ref: 28a66676467 Ref: library/pyexpat module-xml parsers expat errors6676467 Ref: 1396676467 Ref: library/pyexpat xml parsers expat errors codes6677059 Ref: 289e6677059 Ref: library/pyexpat xml parsers expat errors messages6677196 Ref: 289d6677196 Ref: library/pyexpat xml parsers expat errors XML_ERROR_ASYNC_ENTITY6677349 Ref: 28a76677349 Ref: library/pyexpat xml parsers expat errors XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF6677408 Ref: 28a86677408 Ref: library/pyexpat xml parsers expat errors XML_ERROR_BAD_CHAR_REF6677609 Ref: 28a96677609 Ref: library/pyexpat xml parsers expat errors XML_ERROR_BINARY_ENTITY_REF6677804 Ref: 28aa6677804 Ref: library/pyexpat xml parsers expat errors XML_ERROR_DUPLICATE_ATTRIBUTE6677978 Ref: 28ab6677978 Ref: library/pyexpat xml parsers expat errors XML_ERROR_INCORRECT_ENCODING6678103 Ref: 28ac6678103 Ref: library/pyexpat xml parsers expat errors XML_ERROR_INVALID_TOKEN6678168 Ref: 28ad6678168 Ref: library/pyexpat xml parsers expat errors XML_ERROR_JUNK_AFTER_DOC_ELEMENT6678382 Ref: 28ae6678382 Ref: library/pyexpat xml parsers expat errors XML_ERROR_MISPLACED_XML_PI6678531 Ref: 28af6678531 Ref: library/pyexpat xml parsers expat errors XML_ERROR_NO_ELEMENTS6678684 Ref: 28b06678684 Ref: library/pyexpat xml parsers expat errors XML_ERROR_NO_MEMORY6678859 Ref: 28b16678859 Ref: library/pyexpat xml parsers expat errors XML_ERROR_PARAM_ENTITY_REF6678971 Ref: 28b26678971 Ref: library/pyexpat xml parsers expat errors XML_ERROR_PARTIAL_CHAR6679105 Ref: 28b36679105 Ref: library/pyexpat xml parsers expat errors XML_ERROR_RECURSIVE_ENTITY_REF6679218 Ref: 28b46679218 Ref: library/pyexpat xml parsers expat errors XML_ERROR_SYNTAX6679420 Ref: 28b56679420 Ref: library/pyexpat xml parsers expat errors XML_ERROR_TAG_MISMATCH6679526 Ref: 28b66679526 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNCLOSED_TOKEN6679646 Ref: 28b76679646 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNDEFINED_ENTITY6679830 Ref: 28b86679830 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNKNOWN_ENCODING6679956 Ref: 28b96679956 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNCLOSED_CDATA_SECTION6680074 Ref: 28ba6680074 Ref: library/pyexpat xml parsers expat errors XML_ERROR_EXTERNAL_ENTITY_HANDLING6680188 Ref: 28bb6680188 Ref: library/pyexpat xml parsers expat errors XML_ERROR_NOT_STANDALONE6680259 Ref: 28bc6680259 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNEXPECTED_STATE6680522 Ref: 28bd6680522 Ref: library/pyexpat xml parsers expat errors XML_ERROR_ENTITY_DECLARED_IN_PE6680585 Ref: 28be6680585 Ref: library/pyexpat xml parsers expat errors XML_ERROR_FEATURE_REQUIRES_XML_DTD6680653 Ref: 28bf6680653 Ref: library/pyexpat xml parsers expat errors XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING6680959 Ref: 28c06680959 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNBOUND_PREFIX6681232 Ref: 28c16681232 Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNDECLARING_PREFIX6681374 Ref: 28c26681374 Ref: library/pyexpat xml parsers expat errors XML_ERROR_INCOMPLETE_PE6681535 Ref: 28c36681535 Ref: library/pyexpat xml parsers expat errors XML_ERROR_XML_DECL6681649 Ref: 28c46681649 Ref: library/pyexpat xml parsers expat errors XML_ERROR_TEXT_DECL6681761 Ref: 28c56681761 Ref: library/pyexpat xml parsers expat errors XML_ERROR_PUBLICID6681897 Ref: 28c66681897 Ref: library/pyexpat xml parsers expat errors XML_ERROR_SUSPENDED6682019 Ref: 28c76682019 Ref: library/pyexpat xml parsers expat errors XML_ERROR_NOT_SUSPENDED6682243 Ref: 28c86682243 Ref: library/pyexpat xml parsers expat errors XML_ERROR_ABORTED6682395 Ref: 28c96682395 Ref: library/pyexpat xml parsers expat errors XML_ERROR_FINISHED6682507 Ref: 28ca6682507 Ref: library/pyexpat xml parsers expat errors XML_ERROR_SUSPEND_PE6682753 Ref: 28cb6682753 Node: Internet Protocols and Support6682810 Ref: library/internet doc6682975 Ref: 28cc6682975 Ref: library/internet internet6682975 Ref: 28cd6682975 Ref: library/internet internet-protocols-and-support6682975 Ref: 28ce6682975 Node: webbrowser — Convenient Web-browser controller6685106 Ref: library/webbrowser doc6685270 Ref: 28cf6685270 Ref: library/webbrowser module-webbrowser6685270 Ref: 1296685270 Ref: library/webbrowser webbrowser-convenient-web-browser-controller6685270 Ref: 28d06685270 Ref: library/webbrowser webbrowser Error6687218 Ref: 28d26687218 Ref: library/webbrowser webbrowser open6687349 Ref: 28d16687349 Ref: library/webbrowser webbrowser open_new6688156 Ref: 28d36688156 Ref: library/webbrowser webbrowser open_new_tab6688322 Ref: 28d46688322 Ref: library/webbrowser webbrowser get6688500 Ref: 28d56688500 Ref: library/webbrowser webbrowser register6688728 Ref: 28d66688728 Ref: webbrowser — Convenient Web-browser controller-Footnote-16695266 Ref: webbrowser — Convenient Web-browser controller-Footnote-26695335 Node: Browser Controller Objects6695472 Ref: library/webbrowser browser-controller-objects6695583 Ref: 28d76695583 Ref: library/webbrowser browser-controllers6695583 Ref: 28d86695583 Ref: library/webbrowser webbrowser controller open6695763 Ref: 28d96695763 Ref: library/webbrowser webbrowser controller open_new6696027 Ref: 28da6696027 Ref: library/webbrowser webbrowser controller open_new_tab6696246 Ref: 28db6696246 Node: cgi — Common Gateway Interface support6696446 Ref: library/cgi doc6696662 Ref: 28dc6696662 Ref: library/cgi cgi-common-gateway-interface-support6696662 Ref: 28dd6696662 Ref: library/cgi module-cgi6696662 Ref: 166696662 Ref: cgi — Common Gateway Interface support-Footnote-16697329 Node: Introduction<10>6697391 Ref: library/cgi introduction6697513 Ref: 28de6697513 Ref: library/cgi cgi-intro6697558 Ref: 28df6697558 Node: Using the cgi module6699227 Ref: library/cgi id16699380 Ref: 28e06699380 Ref: library/cgi using-the-cgi-module6699380 Ref: 28e16699380 Node: Higher Level Interface6705288 Ref: library/cgi higher-level-interface6705437 Ref: 28e36705437 Ref: library/cgi cgi FieldStorage getfirst6707751 Ref: 28e46707751 Ref: library/cgi cgi FieldStorage getlist6708325 Ref: 28e26708325 Ref: Higher Level Interface-Footnote-16708899 Node: Functions<8>6709157 Ref: library/cgi functions6709307 Ref: 28e56709307 Ref: library/cgi functions-in-cgi-module6709307 Ref: 28e66709307 Ref: library/cgi cgi parse6709489 Ref: 2ed6709489 Ref: library/cgi cgi parse_multipart6709921 Ref: 2ee6709921 Ref: library/cgi cgi parse_header6710899 Ref: 28e76710899 Ref: library/cgi cgi test6711050 Ref: 28e86711050 Ref: library/cgi cgi print_environ6711235 Ref: 28e96711235 Ref: library/cgi cgi print_form6711315 Ref: 28ea6711315 Ref: library/cgi cgi print_directory6711381 Ref: 28eb6711381 Ref: library/cgi cgi print_environ_usage6711463 Ref: 28ec6711463 Node: Caring about security6711579 Ref: library/cgi caring-about-security6711750 Ref: 28ed6711750 Ref: library/cgi cgi-security6711750 Ref: 28ee6711750 Node: Installing your CGI script on a Unix system6712535 Ref: library/cgi installing-your-cgi-script-on-a-unix-system6712717 Ref: 28ef6712717 Node: Testing your CGI script6714747 Ref: library/cgi testing-your-cgi-script6714929 Ref: 28f06714929 Node: Debugging CGI scripts6715543 Ref: library/cgi debugging-cgi-scripts6715711 Ref: 28f16715711 Node: Common problems and solutions6718860 Ref: library/cgi common-problems-and-solutions6718996 Ref: 28f26718996 Node: cgitb — Traceback manager for CGI scripts6720338 Ref: library/cgitb doc6720561 Ref: 28f36720561 Ref: library/cgitb cgitb-traceback-manager-for-cgi-scripts6720561 Ref: 28f46720561 Ref: library/cgitb module-cgitb6720561 Ref: 176720561 Ref: library/cgitb cgitb enable6721751 Ref: 28f56721751 Ref: library/cgitb cgitb text6722685 Ref: 28f66722685 Ref: library/cgitb cgitb html6723113 Ref: 28f76723113 Ref: library/cgitb cgitb handler6723541 Ref: 28f86723541 Ref: cgitb — Traceback manager for CGI scripts-Footnote-16724174 Node: wsgiref — WSGI Utilities and Reference Implementation6724238 Ref: library/wsgiref doc6724452 Ref: 28f96724452 Ref: library/wsgiref module-wsgiref6724452 Ref: 12c6724452 Ref: library/wsgiref wsgiref-wsgi-utilities-and-reference-implementation6724452 Ref: 28fa6724452 Ref: wsgiref — WSGI Utilities and Reference Implementation-Footnote-16726297 Ref: wsgiref — WSGI Utilities and Reference Implementation-Footnote-26726346 Node: wsgiref util – WSGI environment utilities6726383 Ref: library/wsgiref module-wsgiref util6726573 Ref: 1306726573 Ref: library/wsgiref wsgiref-util-wsgi-environment-utilities6726573 Ref: 28fb6726573 Ref: library/wsgiref wsgiref util guess_scheme6727030 Ref: 28fc6727030 Ref: library/wsgiref wsgiref util request_uri6727682 Ref: 28fd6727682 Ref: library/wsgiref wsgiref util application_uri6728008 Ref: 28fe6728008 Ref: library/wsgiref wsgiref util shift_path_info6728274 Ref: 28ff6728274 Ref: library/wsgiref wsgiref util setup_testing_defaults6729942 Ref: 29006729942 Ref: library/wsgiref wsgiref util is_hop_by_hop6731626 Ref: 29016731626 Ref: library/wsgiref wsgiref util FileWrapper6731799 Ref: 27e6731799 Ref: wsgiref util – WSGI environment utilities-Footnote-16733072 Ref: wsgiref util – WSGI environment utilities-Footnote-26733121 Ref: wsgiref util – WSGI environment utilities-Footnote-36733170 Ref: wsgiref util – WSGI environment utilities-Footnote-46733219 Ref: wsgiref util – WSGI environment utilities-Footnote-56733268 Node: wsgiref headers – WSGI response header tools6733317 Ref: library/wsgiref module-wsgiref headers6733567 Ref: 12e6733567 Ref: library/wsgiref wsgiref-headers-wsgi-response-header-tools6733567 Ref: 29026733567 Ref: library/wsgiref wsgiref headers Headers6733829 Ref: 78f6733829 Ref: library/wsgiref wsgiref headers Headers get_all6736094 Ref: 29036736094 Ref: library/wsgiref wsgiref headers Headers add_header6736531 Ref: 29046736531 Ref: wsgiref headers – WSGI response header tools-Footnote-16737668 Node: wsgiref simple_server – a simple WSGI HTTP server6737717 Ref: library/wsgiref module-wsgiref simple_server6737969 Ref: 12f6737969 Ref: library/wsgiref wsgiref-simple-server-a-simple-wsgi-http-server6737969 Ref: 29056737969 Ref: library/wsgiref wsgiref simple_server make_server6738563 Ref: 29066738563 Ref: library/wsgiref wsgiref simple_server demo_app6739403 Ref: 29076739403 Ref: library/wsgiref wsgiref simple_server WSGIServer6739843 Ref: 29086739843 Ref: library/wsgiref wsgiref simple_server WSGIServer set_app6740596 Ref: 290a6740596 Ref: library/wsgiref wsgiref simple_server WSGIServer get_app6740741 Ref: 290b6740741 Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler6741084 Ref: 290c6741084 Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler get_environ6741700 Ref: 290d6741700 Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler get_stderr6742206 Ref: 290e6742206 Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler handle6742389 Ref: 290f6742389 Ref: wsgiref simple_server – a simple WSGI HTTP server-Footnote-16742660 Ref: wsgiref simple_server – a simple WSGI HTTP server-Footnote-26742709 Node: wsgiref validate — WSGI conformance checker6742758 Ref: library/wsgiref module-wsgiref validate6743012 Ref: 1316743012 Ref: library/wsgiref wsgiref-validate-wsgi-conformance-checker6743012 Ref: 29106743012 Ref: library/wsgiref wsgiref validate validator6743919 Ref: 29116743919 Ref: wsgiref validate — WSGI conformance checker-Footnote-16746138 Ref: wsgiref validate — WSGI conformance checker-Footnote-26746187 Ref: wsgiref validate — WSGI conformance checker-Footnote-36746236 Node: wsgiref handlers – server/gateway base classes6746285 Ref: library/wsgiref module-wsgiref handlers6746500 Ref: 12d6746500 Ref: library/wsgiref wsgiref-handlers-server-gateway-base-classes6746500 Ref: 29126746500 Ref: library/wsgiref wsgiref handlers CGIHandler6746891 Ref: 29136746891 Ref: library/wsgiref wsgiref handlers IISCGIHandler6747540 Ref: 29156747540 Ref: library/wsgiref wsgiref handlers BaseCGIHandler6748915 Ref: 29146748915 Ref: library/wsgiref wsgiref handlers SimpleHandler6749782 Ref: 29166749782 Ref: library/wsgiref wsgiref handlers BaseHandler6750699 Ref: 29176750699 Ref: library/wsgiref wsgiref handlers BaseHandler run6751058 Ref: 29186751058 Ref: library/wsgiref wsgiref handlers BaseHandler _write6751397 Ref: 29196751397 Ref: library/wsgiref wsgiref handlers BaseHandler _flush6751743 Ref: 291a6751743 Ref: library/wsgiref wsgiref handlers BaseHandler get_stdin6751952 Ref: 291b6751952 Ref: library/wsgiref wsgiref handlers BaseHandler get_stderr6752117 Ref: 291c6752117 Ref: library/wsgiref wsgiref handlers BaseHandler add_cgi_vars6752285 Ref: 291d6752285 Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_multithread6752837 Ref: 291e6752837 Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_multiprocess6753128 Ref: 291f6753128 Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_run_once6753421 Ref: 29206753421 Ref: library/wsgiref wsgiref handlers BaseHandler os_environ6753664 Ref: 29216753664 Ref: library/wsgiref wsgiref handlers BaseHandler server_software6754170 Ref: 29226754170 Ref: library/wsgiref wsgiref handlers BaseHandler get_scheme6754766 Ref: 29246754766 Ref: library/wsgiref wsgiref handlers BaseHandler setup_environ6755127 Ref: 29256755127 Ref: library/wsgiref wsgiref handlers BaseHandler log_exception6755787 Ref: 29276755787 Ref: library/wsgiref wsgiref handlers BaseHandler traceback_limit6756287 Ref: 29286756287 Ref: library/wsgiref wsgiref handlers BaseHandler error_output6756509 Ref: 29296756509 Ref: library/wsgiref wsgiref handlers BaseHandler error_status6757581 Ref: 292a6757581 Ref: library/wsgiref wsgiref handlers BaseHandler error_headers6757786 Ref: 292b6757786 Ref: library/wsgiref wsgiref handlers BaseHandler error_body6758078 Ref: 292c6758078 Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_file_wrapper6758424 Ref: 29266758424 Ref: library/wsgiref wsgiref handlers BaseHandler sendfile6758632 Ref: 292d6758632 Ref: library/wsgiref wsgiref handlers BaseHandler origin_server6759208 Ref: 29236759208 Ref: library/wsgiref wsgiref handlers BaseHandler http_version6759735 Ref: 292e6759735 Ref: library/wsgiref wsgiref handlers read_environ6759957 Ref: b366759957 Ref: wsgiref handlers – server/gateway base classes-Footnote-16760871 Ref: wsgiref handlers – server/gateway base classes-Footnote-26760920 Ref: wsgiref handlers – server/gateway base classes-Footnote-36760969 Ref: wsgiref handlers – server/gateway base classes-Footnote-46761018 Ref: wsgiref handlers – server/gateway base classes-Footnote-56761067 Node: Examples<20>6761116 Ref: library/wsgiref examples6761277 Ref: 292f6761277 Node: urllib — URL handling modules6763849 Ref: library/urllib doc6764074 Ref: 29306764074 Ref: library/urllib module-urllib6764074 Ref: 11d6764074 Ref: library/urllib urllib-url-handling-modules6764074 Ref: 29316764074 Ref: urllib — URL handling modules-Footnote-16764655 Node: urllib request — Extensible library for opening URLs6764718 Ref: library/urllib request doc6764939 Ref: 29326764939 Ref: library/urllib request module-urllib request6764939 Ref: 1206764939 Ref: library/urllib request urllib-request-extensible-library-for-opening-urls6764939 Ref: 29336764939 Ref: library/urllib request urllib request urlopen6765550 Ref: 78c6765550 Ref: library/urllib request urllib request install_opener6769862 Ref: 293b6769862 Ref: library/urllib request urllib request build_opener6770315 Ref: 293c6770315 Ref: library/urllib request urllib request pathname2url6771433 Ref: 29446771433 Ref: library/urllib request urllib request url2pathname6771732 Ref: 29456771732 Ref: library/urllib request urllib request getproxies6771989 Ref: 29476771989 Ref: library/urllib request urllib request Request6773148 Ref: 8f66773148 Ref: library/urllib request urllib request OpenerDirector6777579 Ref: 29386777579 Ref: library/urllib request urllib request BaseHandler6777798 Ref: 293d6777798 Ref: library/urllib request urllib request HTTPDefaultErrorHandler6777958 Ref: 293f6777958 Ref: library/urllib request urllib request HTTPRedirectHandler6778150 Ref: 29406778150 Ref: library/urllib request urllib request HTTPCookieProcessor6778235 Ref: 29496778235 Ref: library/urllib request urllib request ProxyHandler6778337 Ref: 293a6778337 Ref: library/urllib request urllib request HTTPPasswordMgr6779449 Ref: 294a6779449 Ref: library/urllib request urllib request HTTPPasswordMgrWithDefaultRealm6779566 Ref: 294b6779566 Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth6779807 Ref: 78a6779807 Ref: library/urllib request urllib request AbstractBasicAuthHandler6780193 Ref: 294c6780193 Ref: library/urllib request urllib request HTTPBasicAuthHandler6781535 Ref: 294f6781535 Ref: library/urllib request urllib request ProxyBasicAuthHandler6781999 Ref: 29506781999 Ref: library/urllib request urllib request AbstractDigestAuthHandler6782339 Ref: 29516782339 Ref: library/urllib request urllib request HTTPDigestAuthHandler6782749 Ref: 29526782749 Ref: library/urllib request urllib request ProxyDigestAuthHandler6783611 Ref: 29536783611 Ref: library/urllib request urllib request HTTPHandler6783952 Ref: 293e6783952 Ref: library/urllib request urllib request HTTPSHandler6784037 Ref: ba86784037 Ref: library/urllib request urllib request FileHandler6784367 Ref: 29426784367 Ref: library/urllib request urllib request DataHandler6784430 Ref: 8f56784430 Ref: library/urllib request urllib request FTPHandler6784517 Ref: 29416784517 Ref: library/urllib request urllib request CacheFTPHandler6784576 Ref: 29546784576 Ref: library/urllib request urllib request UnknownHandler6784705 Ref: 29396784705 Ref: library/urllib request urllib request HTTPErrorProcessor6784795 Ref: 29436784795 Ref: urllib request — Extensible library for opening URLs-Footnote-16785676 Ref: urllib request — Extensible library for opening URLs-Footnote-26785749 Ref: urllib request — Extensible library for opening URLs-Footnote-36785800 Ref: urllib request — Extensible library for opening URLs-Footnote-46785837 Ref: urllib request — Extensible library for opening URLs-Footnote-56785886 Ref: urllib request — Extensible library for opening URLs-Footnote-66785935 Node: Request Objects6785984 Ref: library/urllib request id16786121 Ref: 29556786121 Ref: library/urllib request request-objects6786121 Ref: 29566786121 Ref: library/urllib request urllib request Request full_url6786392 Ref: 8f86786392 Ref: library/urllib request urllib request Request type6786687 Ref: 29576786687 Ref: library/urllib request urllib request Request host6786738 Ref: 29586786738 Ref: library/urllib request urllib request Request origin_req_host6786865 Ref: 29596786865 Ref: library/urllib request urllib request Request selector6786960 Ref: 295a6786960 Ref: library/urllib request urllib request Request data6787124 Ref: 8f96787124 Ref: library/urllib request urllib request Request unverifiable6787387 Ref: 295b6787387 Ref: library/urllib request urllib request Request method6787517 Ref: 8f76787517 Ref: library/urllib request urllib request Request get_method6788223 Ref: ac16788223 Ref: library/urllib request urllib request Request add_header6788645 Ref: 29486788645 Ref: library/urllib request urllib request Request add_unredirected_header6789238 Ref: 295c6789238 Ref: library/urllib request urllib request Request has_header6789364 Ref: 295d6789364 Ref: library/urllib request urllib request Request remove_header6789505 Ref: 8fb6789505 Ref: library/urllib request urllib request Request get_full_url6789678 Ref: 295e6789678 Ref: library/urllib request urllib request Request set_proxy6789835 Ref: 295f6789835 Ref: library/urllib request urllib request Request get_header6790088 Ref: 29606790088 Ref: library/urllib request urllib request Request header_items6790254 Ref: 29616790254 Ref: Request Objects-Footnote-16790613 Node: OpenerDirector Objects6790662 Ref: library/urllib request opener-director-objects6790827 Ref: 29626790827 Ref: library/urllib request openerdirector-objects6790827 Ref: 29636790827 Ref: library/urllib request urllib request OpenerDirector add_handler6790959 Ref: 29646790959 Ref: library/urllib request urllib request OpenerDirector open6792517 Ref: 8fa6792517 Ref: library/urllib request urllib request OpenerDirector error6793201 Ref: 29696793201 Node: BaseHandler Objects6794977 Ref: library/urllib request base-handler-objects6795154 Ref: 296a6795154 Ref: library/urllib request basehandler-objects6795154 Ref: 296b6795154 Ref: library/urllib request urllib request BaseHandler add_parent6795394 Ref: 296c6795394 Ref: library/urllib request urllib request BaseHandler close6795473 Ref: 296d6795473 Ref: library/urllib request urllib request BaseHandler parent6795849 Ref: 296e6795849 Ref: library/urllib request urllib request BaseHandler default_open6796003 Ref: 296f6796003 Ref: library/urllib request protocol-open6796677 Ref: 29656796677 Ref: library/urllib request urllib request BaseHandler unknown_open6797043 Ref: 29706797043 Ref: library/urllib request urllib request BaseHandler http_error_default6797455 Ref: 29716797455 Ref: library/urllib request http-error-nnn6798262 Ref: 29666798262 Ref: library/urllib request protocol-request6798760 Ref: 29676798760 Ref: library/urllib request protocol-response6799174 Ref: 29686799174 Node: HTTPRedirectHandler Objects6799765 Ref: library/urllib request http-redirect-handler6799947 Ref: 29726799947 Ref: library/urllib request httpredirecthandler-objects6799947 Ref: 29736799947 Ref: library/urllib request urllib request HTTPRedirectHandler redirect_request6800444 Ref: 29746800444 Ref: library/urllib request urllib request HTTPRedirectHandler http_error_3016801528 Ref: 29756801528 Ref: library/urllib request urllib request HTTPRedirectHandler http_error_3026801799 Ref: 29766801799 Ref: library/urllib request urllib request HTTPRedirectHandler http_error_3036801978 Ref: 29776801978 Ref: library/urllib request urllib request HTTPRedirectHandler http_error_3076802161 Ref: 29786802161 Ref: HTTPRedirectHandler Objects-Footnote-16802389 Ref: HTTPRedirectHandler Objects-Footnote-26802438 Node: HTTPCookieProcessor Objects6802487 Ref: library/urllib request http-cookie-processor6802670 Ref: 29796802670 Ref: library/urllib request httpcookieprocessor-objects6802670 Ref: 297a6802670 Ref: library/urllib request urllib request HTTPCookieProcessor cookiejar6802809 Ref: 297b6802809 Node: ProxyHandler Objects6802937 Ref: library/urllib request proxy-handler6803116 Ref: 297d6803116 Ref: library/urllib request proxyhandler-objects6803116 Ref: 297e6803116 Node: HTTPPasswordMgr Objects6803594 Ref: library/urllib request http-password-mgr6803782 Ref: 294d6803782 Ref: library/urllib request httppasswordmgr-objects6803782 Ref: 297f6803782 Ref: library/urllib request urllib request HTTPPasswordMgr add_password6803968 Ref: 29806803968 Ref: library/urllib request urllib request HTTPPasswordMgr find_user_password6804315 Ref: 29816804315 Node: HTTPPasswordMgrWithPriorAuth Objects6804689 Ref: library/urllib request http-password-mgr-with-prior-auth6804889 Ref: 294e6804889 Ref: library/urllib request httppasswordmgrwithpriorauth-objects6804889 Ref: 29826804889 Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth add_password6805143 Ref: 29836805143 Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth find_user_password6805557 Ref: 29846805557 Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth update_authenticated6805716 Ref: 29856805716 Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth is_authenticated6805912 Ref: 29866805912 Node: AbstractBasicAuthHandler Objects6806088 Ref: library/urllib request abstract-basic-auth-handler6806293 Ref: 29876806293 Ref: library/urllib request abstractbasicauthhandler-objects6806293 Ref: 29886806293 Ref: library/urllib request urllib request AbstractBasicAuthHandler http_error_auth_reqed6806378 Ref: 29896806378 Node: HTTPBasicAuthHandler Objects6807198 Ref: library/urllib request http-basic-auth-handler6807396 Ref: 298a6807396 Ref: library/urllib request httpbasicauthhandler-objects6807396 Ref: 298b6807396 Ref: library/urllib request urllib request HTTPBasicAuthHandler http_error_4016807475 Ref: 298c6807475 Node: ProxyBasicAuthHandler Objects6807632 Ref: library/urllib request proxy-basic-auth-handler6807831 Ref: 298d6807831 Ref: library/urllib request proxybasicauthhandler-objects6807831 Ref: 298e6807831 Ref: library/urllib request urllib request ProxyBasicAuthHandler http_error_4076807912 Ref: 298f6807912 Node: AbstractDigestAuthHandler Objects6808070 Ref: library/urllib request abstract-digest-auth-handler6808270 Ref: 29906808270 Ref: library/urllib request abstractdigestauthhandler-objects6808270 Ref: 29916808270 Ref: library/urllib request urllib request AbstractDigestAuthHandler http_error_auth_reqed6808359 Ref: 29926808359 Node: HTTPDigestAuthHandler Objects6808736 Ref: library/urllib request http-digest-auth-handler6808937 Ref: 29936808937 Ref: library/urllib request httpdigestauthhandler-objects6808937 Ref: 29946808937 Ref: library/urllib request urllib request HTTPDigestAuthHandler http_error_4016809018 Ref: 29956809018 Node: ProxyDigestAuthHandler Objects6809176 Ref: library/urllib request proxy-digest-auth-handler6809363 Ref: 29966809363 Ref: library/urllib request proxydigestauthhandler-objects6809363 Ref: 29976809363 Ref: library/urllib request urllib request ProxyDigestAuthHandler http_error_4076809446 Ref: 29986809446 Node: HTTPHandler Objects6809605 Ref: library/urllib request http-handler-objects6809783 Ref: 29996809783 Ref: library/urllib request httphandler-objects6809783 Ref: 299a6809783 Ref: library/urllib request urllib request HTTPHandler http_open6809844 Ref: 299b6809844 Node: HTTPSHandler Objects6809986 Ref: library/urllib request https-handler-objects6810153 Ref: 299c6810153 Ref: library/urllib request httpshandler-objects6810153 Ref: 299d6810153 Ref: library/urllib request urllib request HTTPSHandler https_open6810216 Ref: 299e6810216 Node: FileHandler Objects6810361 Ref: library/urllib request file-handler-objects6810528 Ref: 299f6810528 Ref: library/urllib request filehandler-objects6810528 Ref: 29a06810528 Ref: library/urllib request urllib request FileHandler file_open6810589 Ref: 29a16810589 Node: DataHandler Objects6810891 Ref: library/urllib request data-handler-objects6811056 Ref: 29a26811056 Ref: library/urllib request datahandler-objects6811056 Ref: 29a36811056 Ref: library/urllib request urllib request DataHandler data_open6811117 Ref: 29a46811117 Ref: DataHandler Objects-Footnote-16811676 Node: FTPHandler Objects6811725 Ref: library/urllib request ftp-handler-objects6811894 Ref: 29a56811894 Ref: library/urllib request ftphandler-objects6811894 Ref: 29a66811894 Ref: library/urllib request urllib request FTPHandler ftp_open6811953 Ref: 29a76811953 Node: CacheFTPHandler Objects6812101 Ref: library/urllib request cacheftp-handler-objects6812273 Ref: 29a86812273 Ref: library/urllib request cacheftphandler-objects6812273 Ref: 29a96812273 Ref: library/urllib request urllib request CacheFTPHandler setTimeout6812455 Ref: 29aa6812455 Ref: library/urllib request urllib request CacheFTPHandler setMaxConns6812548 Ref: 29ab6812548 Node: UnknownHandler Objects6812648 Ref: library/urllib request unknown-handler-objects6812828 Ref: 29ac6812828 Ref: library/urllib request unknownhandler-objects6812828 Ref: 29ad6812828 Ref: library/urllib request urllib request UnknownHandler unknown_open6812895 Ref: 29ae6812895 Node: HTTPErrorProcessor Objects6812986 Ref: library/urllib request http-error-processor-objects6813155 Ref: 29af6813155 Ref: library/urllib request httperrorprocessor-objects6813155 Ref: 29b06813155 Ref: library/urllib request urllib request HTTPErrorProcessor http_response6813230 Ref: 29b16813230 Ref: library/urllib request urllib request HTTPErrorProcessor https_response6813700 Ref: 29b26813700 Node: Examples<21>6813863 Ref: library/urllib request examples6814026 Ref: 29b36814026 Ref: library/urllib request urllib-request-examples6814026 Ref: 29b46814026 Ref: library/urllib request urllib-examples6819594 Ref: 29b66819594 Node: Legacy interface6821087 Ref: library/urllib request legacy-interface6821251 Ref: 29b76821251 Ref: library/urllib request urllib request urlretrieve6821482 Ref: 29b86821482 Ref: library/urllib request urllib request urlcleanup6824144 Ref: 29b96824144 Ref: library/urllib request urllib request URLopener6824304 Ref: 29356824304 Ref: library/urllib request urllib request URLopener open6825813 Ref: 29bb6825813 Ref: library/urllib request urllib request URLopener open_unknown6826316 Ref: 29bc6826316 Ref: library/urllib request urllib request URLopener retrieve6826428 Ref: 29bd6826428 Ref: library/urllib request urllib request URLopener version6827977 Ref: 29ba6827977 Ref: library/urllib request urllib request FancyURLopener6828298 Ref: 29366828298 Ref: library/urllib request urllib request FancyURLopener prompt_user_passwd6830035 Ref: 29be6830035 Ref: Legacy interface-Footnote-16830575 Node: urllib request Restrictions6830624 Ref: library/urllib request urllib-request-restrictions6830767 Ref: 29bf6830767 Node: urllib response — Response classes used by urllib6833335 Ref: library/urllib request module-urllib response6833568 Ref: 1216833568 Ref: library/urllib request urllib-response-response-classes-used-by-urllib6833568 Ref: 29c06833568 Node: urllib parse — Parse URLs into components6834116 Ref: library/urllib parse doc6834354 Ref: 29c16834354 Ref: library/urllib parse module-urllib parse6834354 Ref: 11f6834354 Ref: library/urllib parse urllib-parse-parse-urls-into-components6834354 Ref: 29c26834354 Ref: urllib parse — Parse URLs into components-Footnote-16835629 Node: URL Parsing6835700 Ref: library/urllib parse url-parsing6835827 Ref: 29c36835827 Ref: library/urllib parse urllib parse urlparse6836000 Ref: 5fa6836000 Ref: library/urllib parse urllib parse parse_qs6843300 Ref: 2eb6843300 Ref: library/urllib parse urllib parse parse_qsl6845483 Ref: 2ec6845483 Ref: library/urllib parse urllib parse urlunparse6847516 Ref: 29c56847516 Ref: library/urllib parse urllib parse urlsplit6847918 Ref: 5f96847918 Ref: library/urllib parse urllib parse urlunsplit6851950 Ref: 29c66851950 Ref: library/urllib parse urllib parse urljoin6852394 Ref: 78d6852394 Ref: library/urllib parse urllib parse urldefrag6853704 Ref: bde6853704 Ref: library/urllib parse urllib parse unwrap6855049 Ref: 29c76855049 Ref: URL Parsing-Footnote-16855397 Ref: URL Parsing-Footnote-26855446 Ref: URL Parsing-Footnote-36855495 Ref: URL Parsing-Footnote-46855544 Node: Parsing ASCII Encoded Bytes6855593 Ref: library/urllib parse id16855753 Ref: 29c86855753 Ref: library/urllib parse parsing-ascii-encoded-bytes6855753 Ref: be06855753 Node: Structured Parse Results6857879 Ref: library/urllib parse structured-parse-results6858039 Ref: 29c96858039 Ref: library/urllib parse urlparse-result-object6858039 Ref: 29c46858039 Ref: library/urllib parse urllib parse urllib parse SplitResult geturl6858455 Ref: 29ca6858455 Ref: library/urllib parse urllib parse DefragResult6859578 Ref: 29cb6859578 Ref: library/urllib parse urllib parse ParseResult6859836 Ref: 29cd6859836 Ref: library/urllib parse urllib parse SplitResult6860107 Ref: 29cf6860107 Ref: library/urllib parse urllib parse DefragResultBytes6860512 Ref: 29cc6860512 Ref: library/urllib parse urllib parse ParseResultBytes6860772 Ref: 29ce6860772 Ref: library/urllib parse urllib parse SplitResultBytes6861071 Ref: 29d06861071 Node: URL Quoting6861362 Ref: library/urllib parse url-quoting6861486 Ref: 29d16861486 Ref: library/urllib parse urllib parse quote6861889 Ref: 40d6861889 Ref: library/urllib parse urllib parse quote_plus6863249 Ref: bdf6863249 Ref: library/urllib parse urllib parse quote_from_bytes6863740 Ref: 29d26863740 Ref: library/urllib parse urllib parse unquote6864033 Ref: 29466864033 Ref: library/urllib parse urllib parse unquote_plus6864662 Ref: 29d36864662 Ref: library/urllib parse urllib parse unquote_to_bytes6865000 Ref: 29d46865000 Ref: library/urllib parse urllib parse urlencode6865418 Ref: 78b6865418 Ref: URL Quoting-Footnote-16869051 Ref: URL Quoting-Footnote-26869100 Ref: URL Quoting-Footnote-36869149 Ref: URL Quoting-Footnote-46869198 Ref: URL Quoting-Footnote-56869247 Ref: URL Quoting-Footnote-66869296 Ref: URL Quoting-Footnote-76869345 Ref: URL Quoting-Footnote-86869394 Node: urllib error — Exception classes raised by urllib request6869443 Ref: library/urllib error doc6869674 Ref: 29d56869674 Ref: library/urllib error module-urllib error6869674 Ref: 11e6869674 Ref: library/urllib error urllib-error-exception-classes-raised-by-urllib-request6869674 Ref: 29d66869674 Ref: library/urllib error urllib error URLError6870173 Ref: 29376870173 Ref: library/urllib error urllib error URLError reason6870351 Ref: 29d76870351 Ref: library/urllib error urllib error HTTPError6870622 Ref: 8fc6870622 Ref: library/urllib error urllib error HTTPError code6870979 Ref: 29d86870979 Ref: library/urllib error urllib error HTTPError reason6871239 Ref: 29da6871239 Ref: library/urllib error urllib error HTTPError headers6871341 Ref: 8fd6871341 Ref: library/urllib error urllib error ContentTooShortError6871507 Ref: 29db6871507 Ref: urllib error — Exception classes raised by urllib request-Footnote-16871907 Ref: urllib error — Exception classes raised by urllib request-Footnote-26871978 Node: urllib robotparser — Parser for robots txt6872027 Ref: library/urllib robotparser doc6872236 Ref: 29dc6872236 Ref: library/urllib robotparser module-urllib robotparser6872236 Ref: 1226872236 Ref: library/urllib robotparser urllib-robotparser-parser-for-robots-txt6872236 Ref: 29dd6872236 Ref: library/urllib robotparser urllib robotparser RobotFileParser6872779 Ref: 5ad6872779 Ref: library/urllib robotparser urllib robotparser RobotFileParser set_url6872952 Ref: 29de6872952 Ref: library/urllib robotparser urllib robotparser RobotFileParser read6873046 Ref: 29df6873046 Ref: library/urllib robotparser urllib robotparser RobotFileParser parse6873142 Ref: 29e06873142 Ref: library/urllib robotparser urllib robotparser RobotFileParser can_fetch6873212 Ref: 29e16873212 Ref: library/urllib robotparser urllib robotparser RobotFileParser mtime6873426 Ref: 29e26873426 Ref: library/urllib robotparser urllib robotparser RobotFileParser modified6873654 Ref: 29e36873654 Ref: library/urllib robotparser urllib robotparser RobotFileParser crawl_delay6873783 Ref: 29e46873783 Ref: library/urllib robotparser urllib robotparser RobotFileParser request_rate6874185 Ref: 29e56874185 Ref: library/urllib robotparser urllib robotparser RobotFileParser site_maps6874636 Ref: 29e66874636 Ref: urllib robotparser — Parser for robots txt-Footnote-16875556 Node: http — HTTP modules6875634 Ref: library/http doc6875820 Ref: 29e76875820 Ref: library/http http-http-modules6875820 Ref: 29e86875820 Ref: library/http module-http6875820 Ref: 936875820 Ref: library/http http HTTPStatus6876643 Ref: 6e26876643 Ref: http — HTTP modules-Footnote-16877383 Node: HTTP status codes6877455 Ref: library/http http-status-codes6877530 Ref: 29e96877530 Ref: library/http id16877530 Ref: 29ea6877530 Ref: HTTP status codes-Footnote-16890588 Ref: HTTP status codes-Footnote-26890672 Ref: HTTP status codes-Footnote-36890721 Ref: HTTP status codes-Footnote-46890770 Ref: HTTP status codes-Footnote-56890819 Ref: HTTP status codes-Footnote-66890868 Ref: HTTP status codes-Footnote-76890917 Ref: HTTP status codes-Footnote-86890966 Ref: HTTP status codes-Footnote-96891015 Ref: HTTP status codes-Footnote-106891064 Ref: HTTP status codes-Footnote-116891114 Ref: HTTP status codes-Footnote-126891164 Ref: HTTP status codes-Footnote-136891214 Ref: HTTP status codes-Footnote-146891264 Ref: HTTP status codes-Footnote-156891314 Ref: HTTP status codes-Footnote-166891364 Ref: HTTP status codes-Footnote-176891414 Ref: HTTP status codes-Footnote-186891464 Ref: HTTP status codes-Footnote-196891514 Ref: HTTP status codes-Footnote-206891564 Ref: HTTP status codes-Footnote-216891614 Ref: HTTP status codes-Footnote-226891664 Ref: HTTP status codes-Footnote-236891714 Ref: HTTP status codes-Footnote-246891764 Ref: HTTP status codes-Footnote-256891814 Ref: HTTP status codes-Footnote-266891864 Ref: HTTP status codes-Footnote-276891914 Ref: HTTP status codes-Footnote-286891964 Ref: HTTP status codes-Footnote-296892014 Ref: HTTP status codes-Footnote-306892064 Ref: HTTP status codes-Footnote-316892114 Ref: HTTP status codes-Footnote-326892164 Ref: HTTP status codes-Footnote-336892214 Ref: HTTP status codes-Footnote-346892264 Ref: HTTP status codes-Footnote-356892314 Ref: HTTP status codes-Footnote-366892364 Ref: HTTP status codes-Footnote-376892414 Ref: HTTP status codes-Footnote-386892464 Ref: HTTP status codes-Footnote-396892514 Ref: HTTP status codes-Footnote-406892564 Ref: HTTP status codes-Footnote-416892614 Ref: HTTP status codes-Footnote-426892664 Ref: HTTP status codes-Footnote-436892714 Ref: HTTP status codes-Footnote-446892764 Ref: HTTP status codes-Footnote-456892814 Ref: HTTP status codes-Footnote-466892864 Ref: HTTP status codes-Footnote-476892914 Ref: HTTP status codes-Footnote-486892964 Ref: HTTP status codes-Footnote-496893014 Ref: HTTP status codes-Footnote-506893064 Ref: HTTP status codes-Footnote-516893114 Ref: HTTP status codes-Footnote-526893164 Ref: HTTP status codes-Footnote-536893214 Ref: HTTP status codes-Footnote-546893264 Ref: HTTP status codes-Footnote-556893314 Ref: HTTP status codes-Footnote-566893364 Ref: HTTP status codes-Footnote-576893414 Ref: HTTP status codes-Footnote-586893464 Ref: HTTP status codes-Footnote-596893514 Ref: HTTP status codes-Footnote-606893564 Node: http client — HTTP protocol client6893614 Ref: library/http client doc6893786 Ref: 29eb6893786 Ref: library/http client http-client-http-protocol-client6893786 Ref: 29ec6893786 Ref: library/http client module-http client6893786 Ref: 946893786 Ref: library/http client http client HTTPConnection6894478 Ref: 3926894478 Ref: library/http client http client HTTPSConnection6896056 Ref: 3936896056 Ref: library/http client http client HTTPResponse6897890 Ref: a116897890 Ref: library/http client http client parse_headers6898272 Ref: 29ed6898272 Ref: library/http client http client HTTPException6899207 Ref: 29f06899207 Ref: library/http client http client NotConnected6899358 Ref: 29f16899358 Ref: library/http client http client InvalidURL6899446 Ref: 29f26899446 Ref: library/http client http client UnknownProtocol6899599 Ref: 29f36899599 Ref: library/http client http client UnknownTransferEncoding6899690 Ref: 29f46899690 Ref: library/http client http client UnimplementedFileMode6899789 Ref: 29f56899789 Ref: library/http client http client IncompleteRead6899886 Ref: 29f66899886 Ref: library/http client http client ImproperConnectionState6899976 Ref: 29f76899976 Ref: library/http client http client CannotSendRequest6900075 Ref: 29f86900075 Ref: library/http client http client CannotSendHeader6900178 Ref: 29f96900178 Ref: library/http client http client ResponseNotReady6900280 Ref: 29fa6900280 Ref: library/http client http client BadStatusLine6900382 Ref: 29fb6900382 Ref: library/http client http client LineTooLong6900557 Ref: 29fc6900557 Ref: library/http client http client RemoteDisconnected6900735 Ref: 6e56900735 Ref: library/http client http client HTTP_PORT6901214 Ref: 29fd6901214 Ref: library/http client http client HTTPS_PORT6901311 Ref: 29fe6901311 Ref: library/http client http client responses6901411 Ref: 29ff6901411 Ref: http client — HTTP protocol client-Footnote-16901872 Ref: http client — HTTP protocol client-Footnote-26901942 Ref: http client — HTTP protocol client-Footnote-36901993 Node: HTTPConnection Objects6902042 Ref: library/http client httpconnection-objects6902166 Ref: 2a006902166 Ref: library/http client id16902166 Ref: 2a016902166 Ref: library/http client http client HTTPConnection request6902299 Ref: 54f6902299 Ref: library/http client http client HTTPConnection getresponse6905081 Ref: 6e46905081 Ref: library/http client http client HTTPConnection set_debuglevel6905573 Ref: 2a026905573 Ref: library/http client http client HTTPConnection set_tunnel6905974 Ref: bad6905974 Ref: library/http client http client HTTPConnection connect6906979 Ref: 2a036906979 Ref: library/http client http client HTTPConnection close6907209 Ref: 2a046907209 Ref: library/http client http client HTTPConnection blocksize6907288 Ref: 2a056907288 Ref: library/http client http client HTTPConnection putrequest6907572 Ref: 2a066907572 Ref: library/http client http client HTTPConnection putheader6908121 Ref: 2a076908121 Ref: library/http client http client HTTPConnection endheaders6908456 Ref: 5506908456 Ref: library/http client http client HTTPConnection send6909825 Ref: 2a086909825 Ref: HTTPConnection Objects-Footnote-16910083 Ref: HTTPConnection Objects-Footnote-26910131 Node: HTTPResponse Objects6910180 Ref: library/http client httpresponse-objects6910325 Ref: 2a096910325 Ref: library/http client id26910325 Ref: 2a0a6910325 Ref: library/http client http client HTTPResponse read6910739 Ref: 2a0b6910739 Ref: library/http client http client HTTPResponse readinto6910852 Ref: a126910852 Ref: library/http client http client HTTPResponse getheader6911039 Ref: 2a0c6911039 Ref: library/http client http client HTTPResponse getheaders6911430 Ref: 2a0d6911430 Ref: library/http client http client HTTPResponse fileno6911517 Ref: 2a0e6911517 Ref: library/http client http client HTTPResponse msg6911609 Ref: 29ee6911609 Ref: library/http client http client HTTPResponse version6911814 Ref: 2a0f6911814 Ref: library/http client http client HTTPResponse status6911935 Ref: 2a106911935 Ref: library/http client http client HTTPResponse reason6912009 Ref: 29346912009 Ref: library/http client http client HTTPResponse debuglevel6912085 Ref: 2a116912085 Ref: library/http client http client HTTPResponse closed6912280 Ref: 2a126912280 Node: Examples<22>6912361 Ref: library/http client examples6912503 Ref: 2a136912503 Node: HTTPMessage Objects6915419 Ref: library/http client httpmessage-objects6915532 Ref: 2a146915532 Ref: library/http client id36915532 Ref: 2a156915532 Node: ftplib — FTP protocol client6915747 Ref: library/ftplib doc6915929 Ref: 2a166915929 Ref: library/ftplib ftplib-ftp-protocol-client6915929 Ref: 2a176915929 Ref: library/ftplib module-ftplib6915929 Ref: 846915929 Ref: library/ftplib ftplib FTP6917464 Ref: 2f06917464 Ref: library/ftplib ftplib FTP_TLS6918960 Ref: a036918960 Ref: library/ftplib ftplib error_reply6921249 Ref: 2a196921249 Ref: library/ftplib ftplib error_temp6921366 Ref: 2a1a6921366 Ref: library/ftplib ftplib error_perm6921529 Ref: 2a1b6921529 Ref: library/ftplib ftplib error_proto6921692 Ref: 2a1c6921692 Ref: library/ftplib ftplib all_errors6921923 Ref: 2a1d6921923 Ref: ftplib — FTP protocol client-Footnote-16922585 Ref: ftplib — FTP protocol client-Footnote-26922650 Ref: ftplib — FTP protocol client-Footnote-36922698 Node: FTP Objects6922747 Ref: library/ftplib ftp-objects6922849 Ref: 2a1e6922849 Ref: library/ftplib id16922849 Ref: 2a1f6922849 Ref: library/ftplib ftplib FTP set_debuglevel6923186 Ref: 2a206923186 Ref: library/ftplib ftplib FTP connect6923650 Ref: 2a216923650 Ref: library/ftplib ftplib FTP getwelcome6924661 Ref: 2a226924661 Ref: library/ftplib ftplib FTP login6924891 Ref: 2a236924891 Ref: library/ftplib ftplib FTP abort6925604 Ref: 2a246925604 Ref: library/ftplib ftplib FTP sendcmd6925742 Ref: 2a256925742 Ref: library/ftplib ftplib FTP voidcmd6925966 Ref: 2a266925966 Ref: library/ftplib ftplib FTP retrbinary6926339 Ref: 2a276926339 Ref: library/ftplib ftplib FTP retrlines6927019 Ref: 2a296927019 Ref: library/ftplib ftplib FTP set_pasv6927641 Ref: 2a2a6927641 Ref: library/ftplib ftplib FTP storbinary6927792 Ref: c9f6927792 Ref: library/ftplib ftplib FTP storlines6928492 Ref: 2a2b6928492 Ref: library/ftplib ftplib FTP transfercmd6928957 Ref: 2a286928957 Ref: library/ftplib ftplib FTP ntransfercmd6930207 Ref: 2a2c6930207 Ref: library/ftplib ftplib FTP mlsd6930557 Ref: a056930557 Ref: library/ftplib ftplib FTP nlst6931249 Ref: a066931249 Ref: library/ftplib ftplib FTP dir6931660 Ref: a076931660 Ref: library/ftplib ftplib FTP rename6932295 Ref: 2a2d6932295 Ref: library/ftplib ftplib FTP delete6932394 Ref: 2a2e6932394 Ref: library/ftplib ftplib FTP cwd6932657 Ref: 2a2f6932657 Ref: library/ftplib ftplib FTP mkd6932736 Ref: 2a306932736 Ref: library/ftplib ftplib FTP pwd6932812 Ref: 2a316932812 Ref: library/ftplib ftplib FTP rmd6932902 Ref: 2a326932902 Ref: library/ftplib ftplib FTP size6932991 Ref: 2a336932991 Ref: library/ftplib ftplib FTP quit6933317 Ref: 2a346933317 Ref: library/ftplib ftplib FTP close6933727 Ref: 2a356933727 Ref: FTP Objects-Footnote-16934187 Ref: FTP Objects-Footnote-26934235 Node: FTP_TLS Objects6934284 Ref: library/ftplib ftp-tls-objects6934386 Ref: 2a366934386 Ref: library/ftplib ftplib FTP_TLS ssl_version6934531 Ref: 2a376934531 Ref: library/ftplib ftplib FTP_TLS auth6934649 Ref: 2a386934649 Ref: library/ftplib ftplib FTP_TLS ccc6935007 Ref: a046935007 Ref: library/ftplib ftplib FTP_TLS prot_p6935247 Ref: 2a186935247 Ref: library/ftplib ftplib FTP_TLS prot_c6935315 Ref: 2a396935315 Node: poplib — POP3 protocol client6935387 Ref: library/poplib doc6935566 Ref: 2a3a6935566 Ref: library/poplib module-poplib6935566 Ref: d06935566 Ref: library/poplib poplib-pop3-protocol-client6935566 Ref: 2a3b6935566 Ref: library/poplib poplib POP36936681 Ref: 2a3c6936681 Ref: library/poplib poplib POP3_SSL6937421 Ref: bc16937421 Ref: library/poplib poplib error_proto6939193 Ref: b176939193 Ref: poplib — POP3 protocol client-Footnote-16939846 Ref: poplib — POP3 protocol client-Footnote-26939911 Ref: poplib — POP3 protocol client-Footnote-36939960 Ref: poplib — POP3 protocol client-Footnote-46940009 Ref: poplib — POP3 protocol client-Footnote-56940058 Node: POP3 Objects6940120 Ref: library/poplib id16940221 Ref: 2a3d6940221 Ref: library/poplib pop3-objects6940221 Ref: 2a3e6940221 Ref: library/poplib poplib POP3 set_debuglevel6940455 Ref: 2a3f6940455 Ref: library/poplib poplib POP3 getwelcome6940920 Ref: 2a406940920 Ref: library/poplib poplib POP3 capa6941011 Ref: 8926941011 Ref: library/poplib poplib POP3 user6941200 Ref: 2a416941200 Ref: library/poplib poplib POP3 pass_6941318 Ref: 2a426941318 Ref: library/poplib poplib POP3 apop6941501 Ref: 2a436941501 Ref: library/poplib poplib POP3 rpop6941619 Ref: 2a446941619 Ref: library/poplib poplib POP3 stat6941738 Ref: 2a456941738 Ref: library/poplib poplib POP3 list6941870 Ref: 2a466941870 Ref: library/poplib poplib POP3 retr6942062 Ref: 2a476942062 Ref: library/poplib poplib POP3 dele6942225 Ref: 2a486942225 Ref: library/poplib poplib POP3 rset6942503 Ref: 2a496942503 Ref: library/poplib poplib POP3 noop6942578 Ref: 2a4a6942578 Ref: library/poplib poplib POP3 quit6942654 Ref: b166942654 Ref: library/poplib poplib POP3 top6942744 Ref: 2a4b6942744 Ref: library/poplib poplib POP3 uidl6943281 Ref: 2a4c6943281 Ref: library/poplib poplib POP3 utf86943565 Ref: 7326943565 Ref: library/poplib poplib POP3 stls6943772 Ref: 8936943772 Ref: POP3 Objects-Footnote-16944571 Ref: POP3 Objects-Footnote-26944620 Ref: POP3 Objects-Footnote-36944669 Node: POP3 Example6944718 Ref: library/poplib id26944819 Ref: 2a4d6944819 Ref: library/poplib pop3-example6944819 Ref: 2a4e6944819 Node: imaplib — IMAP4 protocol client6945331 Ref: library/imaplib doc6945512 Ref: 2a4f6945512 Ref: library/imaplib imaplib-imap4-protocol-client6945512 Ref: 2a506945512 Ref: library/imaplib module-imaplib6945512 Ref: 986945512 Ref: library/imaplib imaplib IMAP46946177 Ref: 60b6946177 Ref: library/imaplib imaplib IMAP4 error6947110 Ref: 2a526947110 Ref: library/imaplib imaplib IMAP4 abort6947253 Ref: 2a536947253 Ref: library/imaplib imaplib IMAP4 readonly6947515 Ref: 2a546947515 Ref: library/imaplib imaplib IMAP4_SSL6947872 Ref: a176947872 Ref: library/imaplib imaplib IMAP4_stream6949593 Ref: 2a516949593 Ref: library/imaplib imaplib Internaldate2tuple6949863 Ref: 2a556949863 Ref: library/imaplib imaplib Int2AP6950113 Ref: 2a566950113 Ref: library/imaplib imaplib ParseFlags6950261 Ref: 2a576950261 Ref: library/imaplib imaplib Time2Internaldate6950382 Ref: 2a586950382 Ref: imaplib — IMAP4 protocol client-Footnote-16951725 Ref: imaplib — IMAP4 protocol client-Footnote-26951791 Ref: imaplib — IMAP4 protocol client-Footnote-36951840 Node: IMAP4 Objects6951889 Ref: library/imaplib id16951994 Ref: 2a596951994 Ref: library/imaplib imap4-objects6951994 Ref: 2a5a6951994 Ref: library/imaplib imaplib IMAP4 append6953498 Ref: 2a5b6953498 Ref: library/imaplib imaplib IMAP4 authenticate6953602 Ref: 2a5c6953602 Ref: library/imaplib imaplib IMAP4 check6954438 Ref: 2a5d6954438 Ref: library/imaplib imaplib IMAP4 close6954502 Ref: 2a5e6954502 Ref: library/imaplib imaplib IMAP4 copy6954687 Ref: 2a5f6954687 Ref: library/imaplib imaplib IMAP4 create6954799 Ref: 2a606954799 Ref: library/imaplib imaplib IMAP4 delete6954877 Ref: 2a616954877 Ref: library/imaplib imaplib IMAP4 deleteacl6954955 Ref: 2a626954955 Ref: library/imaplib imaplib IMAP4 enable6955065 Ref: 6ea6955065 Ref: library/imaplib imaplib IMAP4 expunge6955382 Ref: 2a636955382 Ref: library/imaplib imaplib IMAP4 fetch6955630 Ref: 2a646955630 Ref: library/imaplib imaplib IMAP4 getacl6955910 Ref: 2a656955910 Ref: library/imaplib imaplib IMAP4 getannotation6956064 Ref: 2a666956064 Ref: library/imaplib imaplib IMAP4 getquota6956265 Ref: 2a676956265 Ref: library/imaplib imaplib IMAP4 getquotaroot6956439 Ref: 2a686956439 Ref: library/imaplib imaplib IMAP4 list6956627 Ref: 2a696956627 Ref: library/imaplib imaplib IMAP4 login6956896 Ref: 2a6a6956896 Ref: library/imaplib imaplib IMAP4 login_cram_md56957029 Ref: 2a6b6957029 Ref: library/imaplib imaplib IMAP4 logout6957289 Ref: 2a6c6957289 Ref: library/imaplib imaplib IMAP4 lsub6957486 Ref: 2a6d6957486 Ref: library/imaplib imaplib IMAP4 myrights6957776 Ref: 2a6e6957776 Ref: library/imaplib imaplib IMAP4 namespace6957895 Ref: 2a6f6957895 Ref: library/imaplib imaplib IMAP4 noop6957984 Ref: 2a706957984 Ref: library/imaplib imaplib IMAP4 open6958044 Ref: 2a716958044 Ref: library/imaplib imaplib IMAP4 partial6958563 Ref: 2a766958563 Ref: library/imaplib imaplib IMAP4 proxyauth6958740 Ref: 2a776958740 Ref: library/imaplib imaplib IMAP4 read6958892 Ref: 2a726958892 Ref: library/imaplib imaplib IMAP4 readline6959008 Ref: 2a736959008 Ref: library/imaplib imaplib IMAP4 recent6959120 Ref: 2a786959120 Ref: library/imaplib imaplib IMAP4 rename6959275 Ref: 2a796959275 Ref: library/imaplib imaplib IMAP4 response6959383 Ref: 2a7a6959383 Ref: library/imaplib imaplib IMAP4 search6959541 Ref: 2a7b6959541 Ref: library/imaplib imaplib IMAP4 select6960216 Ref: 2a7c6960216 Ref: library/imaplib imaplib IMAP4 send6960511 Ref: 2a746960511 Ref: library/imaplib imaplib IMAP4 setacl6960724 Ref: 2a7d6960724 Ref: library/imaplib imaplib IMAP4 setannotation6960887 Ref: 2a7e6960887 Ref: library/imaplib imaplib IMAP4 setquota6961076 Ref: 2a7f6961076 Ref: library/imaplib imaplib IMAP4 shutdown6961250 Ref: 2a756961250 Ref: library/imaplib imaplib IMAP4 socket6961437 Ref: 2a806961437 Ref: library/imaplib imaplib IMAP4 sort6961523 Ref: 2a816961523 Ref: library/imaplib imaplib IMAP4 starttls6962467 Ref: baa6962467 Ref: library/imaplib imaplib IMAP4 status6962994 Ref: 2a826962994 Ref: library/imaplib imaplib IMAP4 store6963090 Ref: 2a836963090 Ref: library/imaplib imaplib IMAP4 subscribe6964297 Ref: 2a846964297 Ref: library/imaplib imaplib IMAP4 thread6964368 Ref: 2a856964368 Ref: library/imaplib imaplib IMAP4 uid6965495 Ref: 2a866965495 Ref: library/imaplib imaplib IMAP4 unsubscribe6965813 Ref: 2a876965813 Ref: library/imaplib imaplib IMAP4 xatom6965890 Ref: 2a886965890 Ref: library/imaplib imaplib IMAP4 PROTOCOL_VERSION6966094 Ref: 2a896966094 Ref: library/imaplib imaplib IMAP4 debug6966229 Ref: 2a8a6966229 Ref: library/imaplib imaplib IMAP4 utf8_enabled6966432 Ref: 6eb6966432 Ref: IMAP4 Objects-Footnote-16966710 Ref: IMAP4 Objects-Footnote-26966759 Ref: IMAP4 Objects-Footnote-36966808 Ref: IMAP4 Objects-Footnote-46966857 Ref: IMAP4 Objects-Footnote-56966906 Ref: IMAP4 Objects-Footnote-66966955 Node: IMAP4 Example6967004 Ref: library/imaplib id26967109 Ref: 2a8b6967109 Ref: library/imaplib imap4-example6967109 Ref: 2a8c6967109 Node: nntplib — NNTP protocol client6967597 Ref: library/nntplib doc6967779 Ref: 2a8d6967779 Ref: library/nntplib module-nntplib6967779 Ref: c06967779 Ref: library/nntplib nntplib-nntp-protocol-client6967779 Ref: 2a8e6967779 Ref: library/nntplib nntplib NNTP6969631 Ref: a2c6969631 Ref: library/nntplib nntplib NNTP_SSL6971617 Ref: ba56971617 Ref: library/nntplib nntplib NNTPError6972978 Ref: 2a906972978 Ref: library/nntplib nntplib NNTPError response6973224 Ref: 2a916973224 Ref: library/nntplib nntplib NNTPReplyError6973345 Ref: 2a926973345 Ref: library/nntplib nntplib NNTPTemporaryError6973466 Ref: 2a936973466 Ref: library/nntplib nntplib NNTPPermanentError6973594 Ref: 2a8f6973594 Ref: library/nntplib nntplib NNTPProtocolError6973722 Ref: 2a946973722 Ref: library/nntplib nntplib NNTPDataError6973886 Ref: 2a956973886 Ref: nntplib — NNTP protocol client-Footnote-16974100 Ref: nntplib — NNTP protocol client-Footnote-26974166 Ref: nntplib — NNTP protocol client-Footnote-36974215 Ref: nntplib — NNTP protocol client-Footnote-46974263 Ref: nntplib — NNTP protocol client-Footnote-56974312 Node: NNTP Objects6974361 Ref: library/nntplib id16974471 Ref: 2a966974471 Ref: library/nntplib nntp-objects6974471 Ref: 2a976974471 Node: Attributes6974679 Ref: library/nntplib attributes6974757 Ref: 2a986974757 Ref: library/nntplib nntplib NNTP nntp_version6974800 Ref: 2a996974800 Ref: library/nntplib nntplib NNTP nntp_implementation6975066 Ref: 2a9a6975066 Ref: Attributes-Footnote-16975303 Node: Methods<3>6975352 Ref: library/nntplib methods6975430 Ref: 2a9b6975430 Ref: library/nntplib nntplib NNTP quit6976321 Ref: 2a9c6976321 Ref: library/nntplib nntplib NNTP getwelcome6976504 Ref: 2a9d6976504 Ref: library/nntplib nntplib NNTP getcapabilities6976735 Ref: 2a9e6976735 Ref: library/nntplib nntplib NNTP login6977196 Ref: 2a9f6977196 Ref: library/nntplib nntplib NNTP starttls6977814 Ref: ba66977814 Ref: library/nntplib nntplib NNTP newgroups6978614 Ref: 2aa06978614 Ref: library/nntplib nntplib NNTP newnews6979281 Ref: 2aa16979281 Ref: library/nntplib nntplib NNTP list6979652 Ref: 2aa26979652 Ref: library/nntplib nntplib NNTP descriptions6980988 Ref: 2aa36980988 Ref: library/nntplib nntplib NNTP description6981586 Ref: 2aa46981586 Ref: library/nntplib nntplib NNTP group6981954 Ref: 2aa56981954 Ref: library/nntplib nntplib NNTP over6982388 Ref: 2aa66982388 Ref: library/nntplib nntplib NNTP help6984550 Ref: 2aa86984550 Ref: library/nntplib nntplib NNTP stat6984704 Ref: 2aa96984704 Ref: library/nntplib nntplib NNTP next6985373 Ref: 2aaa6985373 Ref: library/nntplib nntplib NNTP last6985467 Ref: 2aab6985467 Ref: library/nntplib nntplib NNTP article6985561 Ref: 2aac6985561 Ref: library/nntplib nntplib NNTP head6986669 Ref: 2aad6986669 Ref: library/nntplib nntplib NNTP body6986903 Ref: 2aae6986903 Ref: library/nntplib nntplib NNTP post6987137 Ref: 2aaf6987137 Ref: library/nntplib nntplib NNTP ihave6987763 Ref: 2ab06987763 Ref: library/nntplib nntplib NNTP date6988039 Ref: 2ab16988039 Ref: library/nntplib nntplib NNTP slave6988207 Ref: 2ab26988207 Ref: library/nntplib nntplib NNTP set_debuglevel6988303 Ref: 2ab36988303 Ref: library/nntplib nntplib NNTP xhdr6988939 Ref: 2ab46988939 Ref: library/nntplib nntplib NNTP xover6989877 Ref: 2ab56989877 Ref: library/nntplib nntplib NNTP xpath6990253 Ref: 2ab66990253 Ref: Methods<3>-Footnote-16990603 Ref: Methods<3>-Footnote-26990652 Ref: Methods<3>-Footnote-36990701 Ref: Methods<3>-Footnote-46990750 Node: Utility functions<2>6990799 Ref: library/nntplib utility-functions6990909 Ref: 2ab76990909 Ref: library/nntplib nntplib decode_header6991023 Ref: 2aa76991023 Node: smtplib — SMTP protocol client6991614 Ref: library/smtplib doc6991784 Ref: 2ab86991784 Ref: library/smtplib module-smtplib6991784 Ref: ed6991784 Ref: library/smtplib smtplib-smtp-protocol-client6991784 Ref: 2ab96991784 Ref: library/smtplib smtplib SMTP6992273 Ref: a816992273 Ref: library/smtplib smtplib SMTP_SSL6994675 Ref: a826994675 Ref: library/smtplib smtplib LMTP6996366 Ref: a836996366 Ref: library/smtplib smtplib SMTPException6997198 Ref: 8b76997198 Ref: library/smtplib smtplib SMTPServerDisconnected6997454 Ref: 2abd6997454 Ref: library/smtplib smtplib SMTPResponseException6997682 Ref: 2abe6997682 Ref: library/smtplib smtplib SMTPSenderRefused6998047 Ref: 2abf6998047 Ref: library/smtplib smtplib SMTPRecipientsRefused6998288 Ref: 2ac06998288 Ref: library/smtplib smtplib SMTPDataError6998561 Ref: 2ac16998561 Ref: library/smtplib smtplib SMTPConnectError6998657 Ref: 2abb6998657 Ref: library/smtplib smtplib SMTPHeloError6998778 Ref: 2ac26998778 Ref: library/smtplib smtplib SMTPNotSupportedError6998865 Ref: 2ac36998865 Ref: library/smtplib smtplib SMTPAuthenticationError6999007 Ref: 2ac46999007 Ref: smtplib — SMTP protocol client-Footnote-16999730 Ref: smtplib — SMTP protocol client-Footnote-26999796 Ref: smtplib — SMTP protocol client-Footnote-36999844 Ref: smtplib — SMTP protocol client-Footnote-46999893 Ref: smtplib — SMTP protocol client-Footnote-56999942 Ref: smtplib — SMTP protocol client-Footnote-66999990 Node: SMTP Objects7000039 Ref: library/smtplib id17000141 Ref: 2ac57000141 Ref: library/smtplib smtp-objects7000141 Ref: 2ac67000141 Ref: library/smtplib smtplib SMTP set_debuglevel7000245 Ref: 7437000245 Ref: library/smtplib smtplib SMTP docmd7000596 Ref: 2ac77000596 Ref: library/smtplib smtplib SMTP connect7001246 Ref: 2aba7001246 Ref: library/smtplib smtplib SMTP helo7001931 Ref: 2ac87001931 Ref: library/smtplib smtplib SMTP ehlo7002391 Ref: 2ac97002391 Ref: library/smtplib smtplib SMTP ehlo_or_helo_if_needed7003284 Ref: 2acb7003284 Ref: library/smtplib smtplib SMTP has_extn7003626 Ref: 2aca7003626 Ref: library/smtplib smtplib SMTP verify7003821 Ref: 2acc7003821 Ref: library/smtplib smtplib SMTP login7004240 Ref: 2acd7004240 Ref: library/smtplib smtplib SMTP auth7005825 Ref: 7427005825 Ref: library/smtplib smtplib SMTP starttls7008068 Ref: a847008068 Ref: library/smtplib smtplib SMTP sendmail7009778 Ref: 7447009778 Ref: library/smtplib smtplib SMTP send_message7013259 Ref: 7457013259 Ref: library/smtplib smtplib SMTP quit7015327 Ref: 2abc7015327 Ref: SMTP Objects-Footnote-17015790 Ref: SMTP Objects-Footnote-27015838 Ref: SMTP Objects-Footnote-37015887 Ref: SMTP Objects-Footnote-47015936 Ref: SMTP Objects-Footnote-57015984 Ref: SMTP Objects-Footnote-67016032 Node: SMTP Example7016081 Ref: library/smtplib id27016183 Ref: 2ace7016183 Ref: library/smtplib smtp-example7016183 Ref: 2acf7016183 Ref: SMTP Example-Footnote-17017616 Node: smtpd — SMTP Server7017664 Ref: library/smtpd doc7017829 Ref: 2ad07017829 Ref: library/smtpd module-smtpd7017829 Ref: ec7017829 Ref: library/smtpd smtpd-smtp-server7017829 Ref: 2ad17017829 Ref: smtpd — SMTP Server-Footnote-17018832 Ref: smtpd — SMTP Server-Footnote-27018896 Ref: smtpd — SMTP Server-Footnote-37018936 Ref: smtpd — SMTP Server-Footnote-47018985 Ref: smtpd — SMTP Server-Footnote-57019034 Node: SMTPServer Objects7019083 Ref: library/smtpd smtpserver-objects7019191 Ref: 2ad27019191 Ref: library/smtpd smtpd SMTPServer7019250 Ref: 6027019250 Ref: library/smtpd smtpd SMTPServer process_message7021107 Ref: 6037021107 Ref: library/smtpd smtpd SMTPServer channel_class7022983 Ref: 2ad37022983 Ref: SMTPServer Objects-Footnote-17023594 Ref: SMTPServer Objects-Footnote-27023643 Ref: SMTPServer Objects-Footnote-37023692 Ref: SMTPServer Objects-Footnote-47023741 Node: DebuggingServer Objects7023790 Ref: library/smtpd debuggingserver-objects7023924 Ref: 2ad47023924 Ref: library/smtpd smtpd DebuggingServer7023993 Ref: 2ad57023993 Node: PureProxy Objects7024195 Ref: library/smtpd pureproxy-objects7024331 Ref: 2ad67024331 Ref: library/smtpd smtpd PureProxy7024388 Ref: 2ad77024388 Node: MailmanProxy Objects7024679 Ref: library/smtpd mailmanproxy-objects7024811 Ref: 2ad87024811 Ref: library/smtpd smtpd MailmanProxy7024874 Ref: 2ad97024874 Node: SMTPChannel Objects7025284 Ref: library/smtpd smtpchannel-objects7025390 Ref: 2ada7025390 Ref: library/smtpd smtpd SMTPChannel7025451 Ref: 6017025451 Ref: library/smtpd smtpd SMTPChannel smtp_server7026946 Ref: 2adb7026946 Ref: library/smtpd smtpd SMTPChannel conn7027050 Ref: 2adc7027050 Ref: library/smtpd smtpd SMTPChannel addr7027137 Ref: 2add7027137 Ref: library/smtpd smtpd SMTPChannel received_lines7027272 Ref: 2ade7027272 Ref: library/smtpd smtpd SMTPChannel smtp_state7027493 Ref: 2adf7027493 Ref: library/smtpd smtpd SMTPChannel seen_greeting7027703 Ref: 2ae07027703 Ref: library/smtpd smtpd SMTPChannel mailfrom7027836 Ref: 2ae17027836 Ref: library/smtpd smtpd SMTPChannel rcpttos7027982 Ref: 2ae27027982 Ref: library/smtpd smtpd SMTPChannel received_data7028137 Ref: 2ae37028137 Ref: library/smtpd smtpd SMTPChannel fqdn7028346 Ref: 2ae47028346 Ref: library/smtpd smtpd SMTPChannel peer7028490 Ref: 2ae57028490 Ref: SMTPChannel Objects-Footnote-17030946 Ref: SMTPChannel Objects-Footnote-27030995 Node: telnetlib — Telnet client7031044 Ref: library/telnetlib doc7031220 Ref: 2ae67031220 Ref: library/telnetlib module-telnetlib7031220 Ref: 1027031220 Ref: library/telnetlib telnetlib-telnet-client7031220 Ref: 2ae77031220 Ref: library/telnetlib telnetlib Telnet7032222 Ref: 5977032222 Ref: telnetlib — Telnet client-Footnote-17033772 Ref: telnetlib — Telnet client-Footnote-27033840 Ref: telnetlib — Telnet client-Footnote-37033888 Node: Telnet Objects7033936 Ref: library/telnetlib id17034037 Ref: 2aea7034037 Ref: library/telnetlib telnet-objects7034037 Ref: 2aeb7034037 Ref: library/telnetlib telnetlib Telnet read_until7034146 Ref: 2aec7034146 Ref: library/telnetlib telnetlib Telnet read_all7034501 Ref: 2aed7034501 Ref: library/telnetlib telnetlib Telnet read_some7034604 Ref: 2aee7034604 Ref: library/telnetlib telnetlib Telnet read_very_eager7034782 Ref: 2aef7034782 Ref: library/telnetlib telnetlib Telnet read_eager7035093 Ref: 2af07035093 Ref: library/telnetlib telnetlib Telnet read_lazy7035367 Ref: 2af17035367 Ref: library/telnetlib telnetlib Telnet read_very_lazy7035658 Ref: 2af27035658 Ref: library/telnetlib telnetlib Telnet read_sb_data7035931 Ref: 2af37035931 Ref: library/telnetlib telnetlib Telnet open7036164 Ref: 2ae87036164 Ref: library/telnetlib telnetlib Telnet msg7036730 Ref: 2af47036730 Ref: library/telnetlib telnetlib Telnet set_debuglevel7036956 Ref: 2af57036956 Ref: library/telnetlib telnetlib Telnet close7037128 Ref: 2ae97037128 Ref: library/telnetlib telnetlib Telnet get_socket7037185 Ref: 2af67037185 Ref: library/telnetlib telnetlib Telnet fileno7037267 Ref: 2af77037267 Ref: library/telnetlib telnetlib Telnet write7037368 Ref: 2af87037368 Ref: library/telnetlib telnetlib Telnet interact7037837 Ref: 2af97037837 Ref: library/telnetlib telnetlib Telnet mt_interact7037933 Ref: 2afa7037933 Ref: library/telnetlib telnetlib Telnet expect7038023 Ref: 2afb7038023 Ref: library/telnetlib telnetlib Telnet set_option_negotiation_callback7039029 Ref: 2afc7039029 Node: Telnet Example7039344 Ref: library/telnetlib id27039445 Ref: 2afd7039445 Ref: library/telnetlib telnet-example7039445 Ref: 2afe7039445 Node: uuid — UUID objects according to RFC 41227040001 Ref: library/uuid doc7040204 Ref: 2aff7040204 Ref: library/uuid module-uuid7040204 Ref: 1247040204 Ref: library/uuid uuid-uuid-objects-according-to-rfc-41227040204 Ref: 2b007040204 Ref: library/uuid uuid SafeUUID7041330 Ref: 2b047041330 Ref: library/uuid uuid SafeUUID safe7041382 Ref: 2b057041382 Ref: library/uuid uuid SafeUUID unsafe7041499 Ref: 2b067041499 Ref: library/uuid uuid SafeUUID unknown7041596 Ref: 2b077041596 Ref: library/uuid uuid UUID7041737 Ref: 2607041737 Ref: library/uuid uuid UUID bytes7043698 Ref: 2b097043698 Ref: library/uuid uuid UUID bytes_le7043827 Ref: 2b0a7043827 Ref: library/uuid uuid UUID fields7043979 Ref: 2b0b7043979 Ref: library/uuid uuid UUID hex7045539 Ref: 2b0c7045539 Ref: library/uuid uuid UUID int7045617 Ref: 2b087045617 Ref: library/uuid uuid UUID urn7045679 Ref: 2b0d7045679 Ref: library/uuid uuid UUID variant7045757 Ref: 2b0e7045757 Ref: library/uuid uuid UUID version7046021 Ref: 2b137046021 Ref: library/uuid uuid UUID is_safe7046159 Ref: 4117046159 Ref: library/uuid uuid getnode7046414 Ref: 4127046414 Ref: library/uuid uuid uuid17047384 Ref: 4137047384 Ref: library/uuid uuid uuid37047736 Ref: 2b017047736 Ref: library/uuid uuid uuid47047905 Ref: 2b027047905 Ref: library/uuid uuid uuid57047964 Ref: 2b037047964 Ref: library/uuid uuid NAMESPACE_DNS7048266 Ref: 2b147048266 Ref: library/uuid uuid NAMESPACE_URL7048393 Ref: 2b157048393 Ref: library/uuid uuid NAMESPACE_OID7048491 Ref: 2b167048491 Ref: library/uuid uuid NAMESPACE_X5007048594 Ref: 2b177048594 Ref: library/uuid uuid RESERVED_NCS7048852 Ref: 2b0f7048852 Ref: library/uuid uuid RFC_41227048919 Ref: 2b107048919 Ref: library/uuid uuid RESERVED_MICROSOFT7048998 Ref: 2b117048998 Ref: library/uuid uuid RESERVED_FUTURE7049077 Ref: 2b127049077 Ref: uuid — UUID objects according to RFC 4122-Footnote-17049455 Ref: uuid — UUID objects according to RFC 4122-Footnote-27049518 Ref: uuid — UUID objects according to RFC 4122-Footnote-37049567 Ref: uuid — UUID objects according to RFC 4122-Footnote-47049616 Ref: uuid — UUID objects according to RFC 4122-Footnote-57049665 Ref: uuid — UUID objects according to RFC 4122-Footnote-67049714 Ref: uuid — UUID objects according to RFC 4122-Footnote-77049763 Node: Example<13>7049812 Ref: library/uuid example7049903 Ref: 2b187049903 Ref: library/uuid uuid-example7049903 Ref: 2b197049903 Node: socketserver — A framework for network servers7051162 Ref: library/socketserver doc7051366 Ref: 2b1a7051366 Ref: library/socketserver module-socketserver7051366 Ref: f07051366 Ref: library/socketserver socketserver-a-framework-for-network-servers7051366 Ref: 2b1b7051366 Ref: library/socketserver socketserver TCPServer7051725 Ref: 2b1c7051725 Ref: library/socketserver socketserver UDPServer7052196 Ref: 2b1f7052196 Ref: library/socketserver socketserver UnixStreamServer7052499 Ref: 2b207052499 Ref: library/socketserver socketserver UnixDatagramServer7052612 Ref: 2b217052612 Ref: socketserver — A framework for network servers-Footnote-17054965 Node: Server Creation Notes7055036 Ref: library/socketserver server-creation-notes7055168 Ref: 2b267055168 Ref: library/socketserver socketserver ForkingMixIn7056002 Ref: 3d57056002 Ref: library/socketserver socketserver ThreadingMixIn7056039 Ref: 3d67056039 Ref: library/socketserver socketserver ForkingTCPServer7057529 Ref: 2b287057529 Ref: library/socketserver socketserver ForkingUDPServer7057570 Ref: 2b297057570 Ref: library/socketserver socketserver ThreadingTCPServer7057611 Ref: 2b2a7057611 Ref: library/socketserver socketserver ThreadingUDPServer7057654 Ref: 2b277057654 Node: Server Objects<2>7059945 Ref: library/socketserver server-objects7060109 Ref: 2b2c7060109 Ref: library/socketserver socketserver BaseServer7060160 Ref: a897060160 Ref: library/socketserver socketserver BaseServer fileno7060559 Ref: 2b2f7060559 Ref: library/socketserver socketserver BaseServer handle_request7060832 Ref: 2b247060832 Ref: library/socketserver socketserver BaseServer serve_forever7061434 Ref: a8b7061434 Ref: library/socketserver socketserver BaseServer service_actions7062085 Ref: a8a7062085 Ref: library/socketserver socketserver BaseServer shutdown7062385 Ref: 2b357062385 Ref: library/socketserver socketserver BaseServer server_close7062665 Ref: 2b257062665 Ref: library/socketserver socketserver BaseServer address_family7062751 Ref: 2b367062751 Ref: library/socketserver socketserver BaseServer RequestHandlerClass7062962 Ref: 2b2e7062962 Ref: library/socketserver socketserver BaseServer server_address7063120 Ref: 2b2d7063120 Ref: library/socketserver socketserver BaseServer socket7063543 Ref: 2b377063543 Ref: library/socketserver socketserver BaseServer allow_reuse_address7063729 Ref: 2b387063729 Ref: library/socketserver socketserver BaseServer request_queue_size7063943 Ref: 2b397063943 Ref: library/socketserver socketserver BaseServer socket_type7064434 Ref: 2b3a7064434 Ref: library/socketserver socketserver BaseServer timeout7064625 Ref: 2b337064625 Ref: library/socketserver socketserver BaseServer finish_request7065131 Ref: 2b3b7065131 Ref: library/socketserver socketserver BaseServer get_request7065348 Ref: 2b307065348 Ref: library/socketserver socketserver BaseServer handle_error7065578 Ref: 5fd7065578 Ref: library/socketserver socketserver BaseServer handle_timeout7066030 Ref: 2b347066030 Ref: library/socketserver socketserver BaseServer process_request7066469 Ref: 2b327066469 Ref: library/socketserver socketserver BaseServer server_activate7066840 Ref: 2b1e7066840 Ref: library/socketserver socketserver BaseServer server_bind7067087 Ref: 2b1d7067087 Ref: library/socketserver socketserver BaseServer verify_request7067241 Ref: 2b317067241 Node: Request Handler Objects7067826 Ref: library/socketserver request-handler-objects7067981 Ref: 2b3c7067981 Ref: library/socketserver socketserver BaseRequestHandler7068050 Ref: 2b227068050 Ref: library/socketserver socketserver BaseRequestHandler setup7068404 Ref: 2b3d7068404 Ref: library/socketserver socketserver BaseRequestHandler handle7068599 Ref: 2b237068599 Ref: library/socketserver socketserver BaseRequestHandler finish7069303 Ref: 2b3e7069303 Ref: library/socketserver socketserver StreamRequestHandler7069582 Ref: 5877069582 Ref: library/socketserver socketserver DatagramRequestHandler7069627 Ref: 2b2b7069627 Node: Examples<23>7070391 Ref: library/socketserver examples7070520 Ref: 2b3f7070520 Node: socketserver TCPServer Example7070725 Ref: library/socketserver socketserver-tcpserver-example7070843 Ref: 2b407070843 Node: socketserver UDPServer Example7073999 Ref: library/socketserver socketserver-udpserver-example7074145 Ref: 2b417074145 Node: Asynchronous Mixins7075762 Ref: library/socketserver asynchronous-mixins7075869 Ref: 2b427075869 Node: http server — HTTP servers7078215 Ref: library/http server doc7078414 Ref: 2b437078414 Ref: library/http server http-server-http-servers7078414 Ref: 2b447078414 Ref: library/http server module-http server7078414 Ref: 977078414 Ref: library/http server http server HTTPServer7079224 Ref: 29097079224 Ref: library/http server http server ThreadingHTTPServer7079579 Ref: 3967079579 Ref: library/http server http server BaseHTTPRequestHandler7080127 Ref: a0e7080127 Ref: library/http server http server BaseHTTPRequestHandler client_address7081117 Ref: 2b457081117 Ref: library/http server http server BaseHTTPRequestHandler server7081259 Ref: 2b467081259 Ref: library/http server http server BaseHTTPRequestHandler close_connection7081328 Ref: 2b477081328 Ref: library/http server http server BaseHTTPRequestHandler requestline7081563 Ref: 2b497081563 Ref: library/http server http server BaseHTTPRequestHandler command7081878 Ref: 2b4a7081878 Ref: library/http server http server BaseHTTPRequestHandler path7081982 Ref: 2b4b7081982 Ref: library/http server http server BaseHTTPRequestHandler request_version7082046 Ref: 2b4c7082046 Ref: library/http server http server BaseHTTPRequestHandler headers7082182 Ref: 29ef7082182 Ref: library/http server http server BaseHTTPRequestHandler rfile7082609 Ref: 2b4e7082609 Ref: library/http server http server BaseHTTPRequestHandler wfile7082761 Ref: 2b4f7082761 Ref: library/http server http server BaseHTTPRequestHandler server_version7083209 Ref: 2b507083209 Ref: library/http server http server BaseHTTPRequestHandler sys_version7083496 Ref: 2b517083496 Ref: library/http server http server BaseHTTPRequestHandler error_message_format7083751 Ref: 2b537083751 Ref: library/http server http server BaseHTTPRequestHandler error_content_type7084112 Ref: 2b547084112 Ref: library/http server http server BaseHTTPRequestHandler protocol_version7084292 Ref: 2b557084292 Ref: library/http server http server BaseHTTPRequestHandler MessageClass7084755 Ref: 2b4d7084755 Ref: library/http server http server BaseHTTPRequestHandler responses7084987 Ref: 29d97084987 Ref: library/http server http server BaseHTTPRequestHandler handle7085552 Ref: 2b587085552 Ref: library/http server http server BaseHTTPRequestHandler handle_one_request7085852 Ref: 2b487085852 Ref: library/http server http server BaseHTTPRequestHandler handle_expect_1007086050 Ref: 2b597086050 Ref: library/http server http server BaseHTTPRequestHandler send_error7086556 Ref: 85c7086556 Ref: library/http server http server BaseHTTPRequestHandler send_response7087684 Ref: 2b5a7087684 Ref: library/http server http server BaseHTTPRequestHandler send_header7088500 Ref: 2b567088500 Ref: library/http server http server BaseHTTPRequestHandler send_response_only7089080 Ref: 2b577089080 Ref: library/http server http server BaseHTTPRequestHandler end_headers7089500 Ref: a0f7089500 Ref: library/http server http server BaseHTTPRequestHandler flush_headers7089799 Ref: a107089799 Ref: library/http server http server BaseHTTPRequestHandler log_request7089971 Ref: 2b5c7089971 Ref: library/http server http server BaseHTTPRequestHandler log_error7090268 Ref: 2b5d7090268 Ref: library/http server http server BaseHTTPRequestHandler log_message7090513 Ref: 2b5e7090513 Ref: library/http server http server BaseHTTPRequestHandler version_string7091002 Ref: 2b527091002 Ref: library/http server http server BaseHTTPRequestHandler date_time_string7091216 Ref: 2b5b7091216 Ref: library/http server http server BaseHTTPRequestHandler log_date_time_string7091604 Ref: 2b5f7091604 Ref: library/http server http server BaseHTTPRequestHandler address_string7091715 Ref: 2b607091715 Ref: library/http server http server SimpleHTTPRequestHandler7091958 Ref: 3957091958 Ref: library/http server http server SimpleHTTPRequestHandler server_version7092515 Ref: 2b637092515 Ref: library/http server http server SimpleHTTPRequestHandler extensions_map7092676 Ref: 2b647092676 Ref: library/http server http server SimpleHTTPRequestHandler directory7092998 Ref: 2b657092998 Ref: library/http server http server SimpleHTTPRequestHandler do_HEAD7093214 Ref: 2b627093214 Ref: library/http server http server SimpleHTTPRequestHandler do_GET7093502 Ref: 2b617093502 Ref: library/http server http-server-cli7095929 Ref: 85d7095929 Ref: library/http server http server CGIHTTPRequestHandler7096940 Ref: 2b667096940 Ref: library/http server http server CGIHTTPRequestHandler cgi_directories7098131 Ref: 2b677098131 Ref: library/http server http server CGIHTTPRequestHandler do_POST7098377 Ref: 2b687098377 Ref: http server — HTTP servers-Footnote-17098954 Ref: http server — HTTP servers-Footnote-27099024 Node: http cookies — HTTP state management7099073 Ref: library/http cookies doc7099275 Ref: 2b697099275 Ref: library/http cookies http-cookies-http-state-management7099275 Ref: 2b6a7099275 Ref: library/http cookies module-http cookies7099275 Ref: 967099275 Ref: library/http cookies http cookies CookieError7100637 Ref: 2b6b7100637 Ref: library/http cookies http cookies BaseCookie7100804 Ref: 2b6c7100804 Ref: library/http cookies http cookies SimpleCookie7101193 Ref: 2b6e7101193 Ref: http cookies — HTTP state management-Footnote-17102023 Ref: http cookies — HTTP state management-Footnote-27102094 Ref: http cookies — HTTP state management-Footnote-37102143 Ref: http cookies — HTTP state management-Footnote-47102192 Ref: http cookies — HTTP state management-Footnote-57102241 Node: Cookie Objects7102290 Ref: library/http cookies cookie-objects7102402 Ref: 2b6f7102402 Ref: library/http cookies id17102402 Ref: 2b707102402 Ref: library/http cookies http cookies BaseCookie value_decode7102453 Ref: 2b717102453 Ref: library/http cookies http cookies BaseCookie value_encode7102725 Ref: 2b727102725 Ref: library/http cookies http cookies BaseCookie output7103177 Ref: 2b737103177 Ref: library/http cookies http cookies BaseCookie js_output7103545 Ref: 2b747103545 Ref: library/http cookies http cookies BaseCookie load7103824 Ref: 2b6d7103824 Node: Morsel Objects7104106 Ref: library/http cookies id27104238 Ref: 2b757104238 Ref: library/http cookies morsel-objects7104238 Ref: 2b767104238 Ref: library/http cookies http cookies Morsel7104289 Ref: 4907104289 Ref: library/http cookies http cookies Morsel value7105641 Ref: 48e7105641 Ref: library/http cookies http cookies Morsel coded_value7105701 Ref: 48f7105701 Ref: library/http cookies http cookies Morsel key7105807 Ref: 48d7105807 Ref: library/http cookies http cookies Morsel set7105864 Ref: 4917105864 Ref: library/http cookies http cookies Morsel isReservedKey7105973 Ref: 2b777105973 Ref: library/http cookies http cookies Morsel output7106084 Ref: 2b787106084 Ref: library/http cookies http cookies Morsel js_output7106424 Ref: 2b797106424 Ref: library/http cookies http cookies Morsel OutputString7106698 Ref: 2b7a7106698 Ref: library/http cookies http cookies Morsel update7106910 Ref: 7c47106910 Ref: library/http cookies http cookies Morsel copy7107210 Ref: 7c37107210 Ref: library/http cookies http cookies Morsel setdefault7107365 Ref: 2b7b7107365 Ref: Morsel Objects-Footnote-17107580 Ref: Morsel Objects-Footnote-27107629 Ref: Morsel Objects-Footnote-37107678 Ref: Morsel Objects-Footnote-47107727 Node: Example<14>7107776 Ref: library/http cookies cookie-example7107885 Ref: 2b7c7107885 Ref: library/http cookies example7107885 Ref: 2b7d7107885 Node: http cookiejar — Cookie handling for HTTP clients7109537 Ref: library/http cookiejar doc7109754 Ref: 2b7e7109754 Ref: library/http cookiejar http-cookiejar-cookie-handling-for-http-clients7109754 Ref: 2b7f7109754 Ref: library/http cookiejar module-http cookiejar7109754 Ref: 957109754 Ref: library/http cookiejar http cookiejar LoadError7111322 Ref: 2b807111322 Ref: library/http cookiejar http cookiejar CookieJar7111697 Ref: 297c7111697 Ref: library/http cookiejar http cookiejar FileCookieJar7112173 Ref: 2b817112173 Ref: library/http cookiejar http cookiejar CookiePolicy7112917 Ref: 2b827112917 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy7113077 Ref: 2b867113077 Ref: library/http cookiejar http cookiejar Cookie7114901 Ref: 2b887114901 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-17116601 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-27116674 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-37116723 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-47116772 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-57116821 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-67116870 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-77116919 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-87116968 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-97117017 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-107117066 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-117117116 Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-127117166 Node: CookieJar and FileCookieJar Objects7117216 Ref: library/http cookiejar cookie-jar-objects7117407 Ref: 2b897117407 Ref: library/http cookiejar cookiejar-and-filecookiejar-objects7117407 Ref: 2b8a7117407 Ref: library/http cookiejar http cookiejar CookieJar add_cookie_header7117684 Ref: 2b8b7117684 Ref: library/http cookiejar http cookiejar CookieJar extract_cookies7118602 Ref: 2b8c7118602 Ref: library/http cookiejar http cookiejar CookieJar set_policy7119837 Ref: 2b8e7119837 Ref: library/http cookiejar http cookiejar CookieJar make_cookies7119941 Ref: 2b8f7119941 Ref: library/http cookiejar http cookiejar CookieJar set_cookie_if_ok7120228 Ref: 2b907120228 Ref: library/http cookiejar http cookiejar CookieJar set_cookie7120353 Ref: 2b917120353 Ref: library/http cookiejar http cookiejar CookieJar clear7120502 Ref: 2b927120502 Ref: library/http cookiejar http cookiejar CookieJar clear_session_cookies7121007 Ref: 2b937121007 Ref: library/http cookiejar http cookiejar FileCookieJar save7121650 Ref: 2b947121650 Ref: library/http cookiejar http cookiejar FileCookieJar load7122503 Ref: 2b837122503 Ref: library/http cookiejar http cookiejar FileCookieJar revert7123070 Ref: 2b847123070 Ref: library/http cookiejar http cookiejar FileCookieJar filename7123469 Ref: 2b957123469 Ref: library/http cookiejar http cookiejar FileCookieJar delayload7123606 Ref: 2b967123606 Node: FileCookieJar subclasses and co-operation with web browsers7124027 Ref: library/http cookiejar file-cookie-jar-classes7124247 Ref: 2b857124247 Ref: library/http cookiejar filecookiejar-subclasses-and-co-operation-with-web-browsers7124247 Ref: 2b977124247 Ref: library/http cookiejar http cookiejar MozillaCookieJar7124475 Ref: 2b987124475 Ref: library/http cookiejar http cookiejar LWPCookieJar7125272 Ref: 2b997125272 Ref: FileCookieJar subclasses and co-operation with web browsers-Footnote-17125750 Node: CookiePolicy Objects7125799 Ref: library/http cookiejar cookie-policy-objects7126011 Ref: 2b9a7126011 Ref: library/http cookiejar cookiepolicy-objects7126011 Ref: 2b9b7126011 Ref: library/http cookiejar http cookiejar CookiePolicy set_ok7126164 Ref: 2b8d7126164 Ref: library/http cookiejar http cookiejar CookiePolicy return_ok7126490 Ref: 2b9c7126490 Ref: library/http cookiejar http cookiejar CookiePolicy domain_return_ok7126819 Ref: 2b9d7126819 Ref: library/http cookiejar http cookiejar CookiePolicy path_return_ok7128197 Ref: 2b9e7128197 Ref: library/http cookiejar http cookiejar CookiePolicy netscape7128649 Ref: 2b9f7128649 Ref: library/http cookiejar http cookiejar CookiePolicy rfc29657128722 Ref: 2ba07128722 Ref: library/http cookiejar http cookiejar CookiePolicy hide_cookie27128797 Ref: 2ba17128797 Ref: CookiePolicy Objects-Footnote-17129348 Ref: CookiePolicy Objects-Footnote-27129397 Node: DefaultCookiePolicy Objects7129446 Ref: library/http cookiejar default-cookie-policy-objects7129616 Ref: 2ba27129616 Ref: library/http cookiejar defaultcookiepolicy-objects7129616 Ref: 2ba37129616 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy blocked_domains7131934 Ref: 2ba47131934 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy set_blocked_domains7132045 Ref: 2ba57132045 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy is_blocked7132159 Ref: 2ba67132159 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy allowed_domains7132301 Ref: 2ba77132301 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy set_allowed_domains7132437 Ref: 2ba87132437 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy is_not_allowed7132571 Ref: 2ba97132571 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy rfc2109_as_netscape7132905 Ref: 2b877132905 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_domain7133492 Ref: 2baa7133492 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_rfc2965_unverifiable7133796 Ref: 2bab7133796 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_unverifiable7134174 Ref: 2bac7134174 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_domain7134323 Ref: 2bad7134323 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_set_initial_dollar7134504 Ref: 2bae7134504 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_set_path7134659 Ref: 2baf7134659 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrictNoDots7134983 Ref: 2bb07134983 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrictNonDomain7135228 Ref: 2bb17135228 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainRFC2965Match7135576 Ref: 2bb27135576 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainLiberal7135813 Ref: 2bb37135813 Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrict7135961 Ref: 2bb47135961 Ref: DefaultCookiePolicy Objects-Footnote-17136114 Ref: DefaultCookiePolicy Objects-Footnote-27136163 Ref: DefaultCookiePolicy Objects-Footnote-37136212 Ref: DefaultCookiePolicy Objects-Footnote-47136261 Ref: DefaultCookiePolicy Objects-Footnote-57136310 Ref: DefaultCookiePolicy Objects-Footnote-67136359 Ref: DefaultCookiePolicy Objects-Footnote-77136408 Node: Cookie Objects<2>7136457 Ref: library/http cookiejar cookie-objects7136619 Ref: 2bb57136619 Ref: library/http cookiejar http cookiejar Cookie version7137388 Ref: 2bb67137388 Ref: library/http cookiejar http cookiejar Cookie name7137746 Ref: 2bb77137746 Ref: library/http cookiejar http cookiejar Cookie value7137804 Ref: 2bb87137804 Ref: library/http cookiejar http cookiejar Cookie port7137884 Ref: 2bb97137884 Ref: library/http cookiejar http cookiejar Cookie path7138023 Ref: 2bba7138023 Ref: library/http cookiejar http cookiejar Cookie secure7138118 Ref: 2bbb7138118 Ref: library/http cookiejar http cookiejar Cookie expires7138225 Ref: 2bbc7138225 Ref: library/http cookiejar http cookiejar Cookie discard7138378 Ref: 2bbe7138378 Ref: library/http cookiejar http cookiejar Cookie comment7138455 Ref: 2bbf7138455 Ref: library/http cookiejar http cookiejar Cookie comment_url7138588 Ref: 2bc07138588 Ref: library/http cookiejar http cookiejar Cookie rfc21097138735 Ref: 2bc17138735 Ref: library/http cookiejar http cookiejar Cookie port_specified7139145 Ref: 2bc27139145 Ref: library/http cookiejar http cookiejar Cookie domain_specified7139324 Ref: 2bc37139324 Ref: library/http cookiejar http cookiejar Cookie domain_initial_dot7139433 Ref: 2bc47139433 Ref: library/http cookiejar http cookiejar Cookie has_nonstandard_attr7139689 Ref: 2bc57139689 Ref: library/http cookiejar http cookiejar Cookie get_nonstandard_attr7139803 Ref: 2bc67139803 Ref: library/http cookiejar http cookiejar Cookie set_nonstandard_attr7139965 Ref: 2bc77139965 Ref: library/http cookiejar http cookiejar Cookie is_expired7140137 Ref: 2bbd7140137 Ref: Cookie Objects<2>-Footnote-17140430 Ref: Cookie Objects<2>-Footnote-27140479 Ref: Cookie Objects<2>-Footnote-37140528 Ref: Cookie Objects<2>-Footnote-47140577 Node: Examples<24>7140626 Ref: library/http cookiejar examples7140752 Ref: 2bc87140752 Ref: Examples<24>-Footnote-17142205 Node: xmlrpc — XMLRPC server and client modules7142254 Ref: library/xmlrpc doc7142472 Ref: 2bc97142472 Ref: library/xmlrpc xmlrpc-xmlrpc-server-and-client-modules7142472 Ref: 2bca7142472 Node: xmlrpc client — XML-RPC client access7142974 Ref: library/xmlrpc client doc7143180 Ref: 2bcb7143180 Ref: library/xmlrpc client module-xmlrpc client7143180 Ref: 13f7143180 Ref: library/xmlrpc client xmlrpc-client-xml-rpc-client-access7143180 Ref: 2bcc7143180 Ref: library/xmlrpc client xmlrpc client ServerProxy7144113 Ref: 2557144113 Ref: xmlrpc client — XML-RPC client access-Footnote-17151932 Ref: xmlrpc client — XML-RPC client access-Footnote-27152004 Ref: xmlrpc client — XML-RPC client access-Footnote-37152098 Ref: xmlrpc client — XML-RPC client access-Footnote-47152157 Ref: xmlrpc client — XML-RPC client access-Footnote-57152216 Ref: xmlrpc client — XML-RPC client access-Footnote-67152262 Node: ServerProxy Objects7152311 Ref: library/xmlrpc client id17152431 Ref: 2bd17152431 Ref: library/xmlrpc client serverproxy-objects7152431 Ref: 2bd27152431 Ref: library/xmlrpc client xmlrpc client ServerProxy system listMethods7153087 Ref: 2bd37153087 Ref: library/xmlrpc client xmlrpc client ServerProxy system methodSignature7153250 Ref: 2bd47153250 Ref: library/xmlrpc client xmlrpc client ServerProxy system methodHelp7154274 Ref: 2bd57154274 Node: DateTime Objects7155349 Ref: library/xmlrpc client datetime-objects7155492 Ref: 2bd67155492 Ref: library/xmlrpc client id27155492 Ref: 2bd77155492 Ref: library/xmlrpc client xmlrpc client DateTime7155547 Ref: 2bcd7155547 Ref: library/xmlrpc client xmlrpc client DateTime decode7155856 Ref: 2bd87155856 Ref: library/xmlrpc client xmlrpc client DateTime encode7155953 Ref: 2bd97155953 Node: Binary Objects7157025 Ref: library/xmlrpc client binary-objects7157162 Ref: 2bda7157162 Ref: library/xmlrpc client id37157162 Ref: 2bdb7157162 Ref: library/xmlrpc client xmlrpc client Binary7157213 Ref: 2bce7157213 Ref: library/xmlrpc client xmlrpc client Binary data7157430 Ref: 2bdc7157430 Ref: library/xmlrpc client xmlrpc client Binary decode7157736 Ref: 2bdd7157736 Ref: library/xmlrpc client xmlrpc client Binary encode7157875 Ref: 2bde7157875 Ref: Binary Objects-Footnote-17159118 Node: Fault Objects7159179 Ref: library/xmlrpc client fault-objects7159321 Ref: 2bdf7159321 Ref: library/xmlrpc client id47159321 Ref: 2be07159321 Ref: library/xmlrpc client xmlrpc client Fault7159370 Ref: 2bcf7159370 Ref: library/xmlrpc client xmlrpc client Fault faultCode7159537 Ref: 2be17159537 Ref: library/xmlrpc client xmlrpc client Fault faultString7159615 Ref: 2be27159615 Node: ProtocolError Objects7160577 Ref: library/xmlrpc client protocol-error-objects7160722 Ref: 2be37160722 Ref: library/xmlrpc client protocolerror-objects7160722 Ref: 2be47160722 Ref: library/xmlrpc client xmlrpc client ProtocolError7160787 Ref: 2bd07160787 Ref: library/xmlrpc client xmlrpc client ProtocolError url7161064 Ref: 2be57161064 Ref: library/xmlrpc client xmlrpc client ProtocolError errcode7161141 Ref: 2be67161141 Ref: library/xmlrpc client xmlrpc client ProtocolError errmsg7161197 Ref: 2be77161197 Ref: library/xmlrpc client xmlrpc client ProtocolError headers7161276 Ref: 2be87161276 Node: MultiCall Objects7162016 Ref: library/xmlrpc client multicall-objects7162169 Ref: 2be97162169 Ref: library/xmlrpc client xmlrpc client MultiCall7162352 Ref: 2bea7162352 Ref: MultiCall Objects-Footnote-17164057 Node: Convenience Functions7164240 Ref: library/xmlrpc client convenience-functions7164395 Ref: 2beb7164395 Ref: library/xmlrpc client xmlrpc client dumps7164460 Ref: 2bec7164460 Ref: library/xmlrpc client xmlrpc client loads7165173 Ref: 2bed7165173 Node: Example of Client Usage7166041 Ref: library/xmlrpc client example-of-client-usage7166213 Ref: 2bee7166213 Ref: library/xmlrpc client xmlrpc-client-example7166213 Ref: 2bef7166213 Node: Example of Client and Server Usage7167520 Ref: library/xmlrpc client example-of-client-and-server-usage7167662 Ref: 2bf07167662 Node: xmlrpc server — Basic XML-RPC servers7167798 Ref: library/xmlrpc server doc7168005 Ref: 2bf27168005 Ref: library/xmlrpc server module-xmlrpc server7168005 Ref: 1407168005 Ref: library/xmlrpc server xmlrpc-server-basic-xml-rpc-servers7168005 Ref: 2bf37168005 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer7168687 Ref: 2bf47168687 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler7170211 Ref: 2bf57170211 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCRequestHandler7170862 Ref: 2bf67170862 Ref: xmlrpc server — Basic XML-RPC servers-Footnote-17171350 Node: SimpleXMLRPCServer Objects7171422 Ref: library/xmlrpc server simple-xmlrpc-servers7171556 Ref: 2bf77171556 Ref: library/xmlrpc server simplexmlrpcserver-objects7171556 Ref: 2bf87171556 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_function7171792 Ref: 2bf97171792 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_instance7172535 Ref: 2bfa7172535 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_introspection_functions7174151 Ref: 2bfb7174151 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_multicall_functions7174360 Ref: 2bfc7174360 Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCRequestHandler rpc_paths7174489 Ref: 2bfd7174489 Node: SimpleXMLRPCServer Example7174909 Ref: library/xmlrpc server id17174998 Ref: 2bfe7174998 Ref: library/xmlrpc server simplexmlrpcserver-example7174998 Ref: 2bf17174998 Node: CGIXMLRPCRequestHandler7179515 Ref: library/xmlrpc server cgixmlrpcrequesthandler7179683 Ref: 2bff7179683 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_function7179867 Ref: 2c007179867 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_instance7180615 Ref: 2c017180615 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_introspection_functions7181500 Ref: 2c027181500 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_multicall_functions7181713 Ref: 2c037181713 Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler handle_request7181852 Ref: 2c047181852 Node: Documenting XMLRPC server7182439 Ref: library/xmlrpc server documenting-xmlrpc-server7182604 Ref: 2c057182604 Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer7182932 Ref: 2c067182932 Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler7183410 Ref: 2c077183410 Ref: library/xmlrpc server xmlrpc server DocXMLRPCRequestHandler7183545 Ref: 2c087183545 Node: DocXMLRPCServer Objects7183864 Ref: library/xmlrpc server doc-xmlrpc-servers7184032 Ref: 2c097184032 Ref: library/xmlrpc server docxmlrpcserver-objects7184032 Ref: 2c0a7184032 Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_title7184469 Ref: 2c0b7184469 Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_name7184659 Ref: 2c0c7184659 Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_documentation7184881 Ref: 2c0d7184881 Node: DocCGIXMLRPCRequestHandler7185137 Ref: library/xmlrpc server doccgixmlrpcrequesthandler7185271 Ref: 2c0e7185271 Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_title7185722 Ref: 2c0f7185722 Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_name7185923 Ref: 2c107185923 Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_documentation7186156 Ref: 2c117186156 Node: ipaddress — IPv4/IPv6 manipulation library7186423 Ref: library/ipaddress doc7186582 Ref: 2c127186582 Ref: library/ipaddress ipaddress-ipv4-ipv6-manipulation-library7186582 Ref: 2c137186582 Ref: library/ipaddress module-ipaddress7186582 Ref: a27186582 Ref: ipaddress — IPv4/IPv6 manipulation library-Footnote-17187605 Node: Convenience factory functions7187673 Ref: library/ipaddress convenience-factory-functions7187804 Ref: 2c157187804 Ref: library/ipaddress ipaddress ip_address7188007 Ref: 2c167188007 Ref: library/ipaddress ipaddress ip_network7188588 Ref: 2c197188588 Ref: library/ipaddress ipaddress ip_interface7189297 Ref: 2c1a7189297 Node: IP Addresses7190150 Ref: library/ipaddress ip-addresses7190312 Ref: 2c1d7190312 Node: Address objects7190455 Ref: library/ipaddress address-objects7190562 Ref: 2c1e7190562 Ref: library/ipaddress ipaddress IPv4Address7191005 Ref: 2c177191005 Ref: library/ipaddress ipaddress IPv4Address version7192069 Ref: 2c207192069 Ref: library/ipaddress ipaddress IPv4Address max_prefixlen7192177 Ref: 2c217192177 Ref: library/ipaddress ipaddress IPv4Address compressed7192515 Ref: 2c227192515 Ref: library/ipaddress ipaddress IPv4Address exploded7192547 Ref: 2c237192547 Ref: library/ipaddress ipaddress IPv4Address packed7193036 Ref: 2c247193036 Ref: library/ipaddress ipaddress IPv4Address reverse_pointer7193273 Ref: 2c257193273 Ref: library/ipaddress ipaddress IPv4Address is_multicast7193818 Ref: 2c267193818 Ref: library/ipaddress ipaddress IPv4Address is_private7193985 Ref: 2c277193985 Ref: library/ipaddress ipaddress IPv4Address is_global7194200 Ref: 86c7194200 Ref: library/ipaddress ipaddress IPv4Address is_unspecified7194444 Ref: 2c287194444 Ref: library/ipaddress ipaddress IPv4Address is_reserved7194598 Ref: 2c297194598 Ref: library/ipaddress ipaddress IPv4Address is_loopback7194696 Ref: 2c2a7194696 Ref: library/ipaddress ipaddress IPv4Address is_link_local7194848 Ref: 2c2b7194848 Ref: library/ipaddress ipaddress IPv6Address7194983 Ref: 2c187194983 Ref: library/ipaddress ipaddress IPv6Address compressed7195911 Ref: 2c2c7195911 Ref: library/ipaddress ipaddress IPv6Address exploded7196220 Ref: 2c2d7196220 Ref: library/ipaddress ipaddress IPv6Address packed7196497 Ref: 2c2e7196497 Ref: library/ipaddress ipaddress IPv6Address reverse_pointer7196525 Ref: 2c2f7196525 Ref: library/ipaddress ipaddress IPv6Address version7196562 Ref: 2c307196562 Ref: library/ipaddress ipaddress IPv6Address max_prefixlen7196591 Ref: 2c317196591 Ref: library/ipaddress ipaddress IPv6Address is_multicast7196626 Ref: 2c327196626 Ref: library/ipaddress ipaddress IPv6Address is_private7196660 Ref: 2c337196660 Ref: library/ipaddress ipaddress IPv6Address is_global7196692 Ref: 2c347196692 Ref: library/ipaddress ipaddress IPv6Address is_unspecified7196723 Ref: 2c357196723 Ref: library/ipaddress ipaddress IPv6Address is_reserved7196759 Ref: 2c367196759 Ref: library/ipaddress ipaddress IPv6Address is_loopback7196792 Ref: 2c377196792 Ref: library/ipaddress ipaddress IPv6Address is_link_local7196825 Ref: 2c387196825 Ref: library/ipaddress ipaddress IPv6Address is_site_local7196901 Ref: 2c397196901 Ref: library/ipaddress ipaddress IPv6Address ipv4_mapped7197247 Ref: 2c3a7197247 Ref: library/ipaddress ipaddress IPv6Address sixtofour7197519 Ref: 2c3b7197519 Ref: library/ipaddress ipaddress IPv6Address teredo7197809 Ref: 2c3c7197809 Ref: Address objects-Footnote-17198159 Ref: Address objects-Footnote-27198208 Ref: Address objects-Footnote-37198257 Ref: Address objects-Footnote-47198359 Ref: Address objects-Footnote-57198461 Ref: Address objects-Footnote-67198563 Ref: Address objects-Footnote-77198665 Ref: Address objects-Footnote-87198714 Ref: Address objects-Footnote-97198763 Ref: Address objects-Footnote-107198812 Ref: Address objects-Footnote-117198862 Ref: Address objects-Footnote-127198912 Ref: Address objects-Footnote-137198962 Ref: Address objects-Footnote-147199012 Ref: Address objects-Footnote-157199062 Ref: Address objects-Footnote-167199112 Node: Conversion to Strings and Integers7199162 Ref: library/ipaddress conversion-to-strings-and-integers7199290 Ref: 2c3d7199290 Node: Operators<3>7199832 Ref: library/ipaddress operators7199936 Ref: 2c3e7199936 Node: Comparison operators7200201 Ref: library/ipaddress comparison-operators7200299 Ref: 2c3f7200299 Node: Arithmetic operators7200672 Ref: library/ipaddress arithmetic-operators7200770 Ref: 2c407200770 Node: IP Network definitions7201273 Ref: library/ipaddress ip-network-definitions7201423 Ref: 2c417201423 Node: Prefix net mask and host mask7202133 Ref: library/ipaddress prefix-net-mask-and-host-mask7202245 Ref: 2c427202245 Node: Network objects7202915 Ref: library/ipaddress network-objects7203048 Ref: 2c437203048 Ref: library/ipaddress ipaddress IPv4Network7203507 Ref: 3a07203507 Ref: library/ipaddress ipaddress IPv4Network version7205930 Ref: 2c457205930 Ref: library/ipaddress ipaddress IPv4Network max_prefixlen7205959 Ref: 2c467205959 Ref: library/ipaddress ipaddress IPv4Network is_multicast7206094 Ref: 2c477206094 Ref: library/ipaddress ipaddress IPv4Network is_private7206128 Ref: 2c487206128 Ref: library/ipaddress ipaddress IPv4Network is_unspecified7206160 Ref: 2c497206160 Ref: library/ipaddress ipaddress IPv4Network is_reserved7206196 Ref: 2c4a7206196 Ref: library/ipaddress ipaddress IPv4Network is_loopback7206229 Ref: 2c4b7206229 Ref: library/ipaddress ipaddress IPv4Network is_link_local7206262 Ref: 2c4c7206262 Ref: library/ipaddress ipaddress IPv4Network network_address7206454 Ref: 2c4d7206454 Ref: library/ipaddress ipaddress IPv4Network broadcast_address7206628 Ref: 2c4e7206628 Ref: library/ipaddress ipaddress IPv4Network hostmask7206825 Ref: 2c4f7206825 Ref: library/ipaddress ipaddress IPv4Network netmask7206920 Ref: 2c507206920 Ref: library/ipaddress ipaddress IPv4Network with_prefixlen7207013 Ref: 2c517207013 Ref: library/ipaddress ipaddress IPv4Network compressed7207049 Ref: 2c527207049 Ref: library/ipaddress ipaddress IPv4Network exploded7207081 Ref: 2c537207081 Ref: library/ipaddress ipaddress IPv4Network with_netmask7207382 Ref: 2c547207382 Ref: library/ipaddress ipaddress IPv4Network with_hostmask7207513 Ref: 2c557207513 Ref: library/ipaddress ipaddress IPv4Network num_addresses7207646 Ref: 2c567207646 Ref: library/ipaddress ipaddress IPv4Network prefixlen7207738 Ref: 2c577207738 Ref: library/ipaddress ipaddress IPv4Network hosts7207819 Ref: 2c587207819 Ref: library/ipaddress ipaddress IPv4Network overlaps7208621 Ref: 2c597208621 Ref: library/ipaddress ipaddress IPv4Network address_exclude7208793 Ref: 2c5a7208793 Ref: library/ipaddress ipaddress IPv4Network subnets7209399 Ref: 7977209399 Ref: library/ipaddress ipaddress IPv4Network supernet7210947 Ref: 7987210947 Ref: library/ipaddress ipaddress IPv4Network subnet_of7211753 Ref: 2c5b7211753 Ref: library/ipaddress ipaddress IPv4Network supernet_of7212050 Ref: 2c5c7212050 Ref: library/ipaddress ipaddress IPv4Network compare_networks7212353 Ref: 2c5d7212353 Ref: library/ipaddress ipaddress IPv6Network7213051 Ref: 39f7213051 Ref: library/ipaddress ipaddress IPv6Network version7214855 Ref: 2c5e7214855 Ref: library/ipaddress ipaddress IPv6Network max_prefixlen7214884 Ref: 2c5f7214884 Ref: library/ipaddress ipaddress IPv6Network is_multicast7214919 Ref: 2c607214919 Ref: library/ipaddress ipaddress IPv6Network is_private7214953 Ref: 2c617214953 Ref: library/ipaddress ipaddress IPv6Network is_unspecified7214985 Ref: 2c627214985 Ref: library/ipaddress ipaddress IPv6Network is_reserved7215021 Ref: 2c637215021 Ref: library/ipaddress ipaddress IPv6Network is_loopback7215054 Ref: 2c647215054 Ref: library/ipaddress ipaddress IPv6Network is_link_local7215087 Ref: 2c657215087 Ref: library/ipaddress ipaddress IPv6Network network_address7215122 Ref: 2c667215122 Ref: library/ipaddress ipaddress IPv6Network broadcast_address7215159 Ref: 2c677215159 Ref: library/ipaddress ipaddress IPv6Network hostmask7215198 Ref: 2c687215198 Ref: library/ipaddress ipaddress IPv6Network netmask7215228 Ref: 2c697215228 Ref: library/ipaddress ipaddress IPv6Network with_prefixlen7215257 Ref: 2c6a7215257 Ref: library/ipaddress ipaddress IPv6Network compressed7215293 Ref: 2c6b7215293 Ref: library/ipaddress ipaddress IPv6Network exploded7215325 Ref: 2c6c7215325 Ref: library/ipaddress ipaddress IPv6Network with_netmask7215355 Ref: 2c6d7215355 Ref: library/ipaddress ipaddress IPv6Network with_hostmask7215389 Ref: 2c6e7215389 Ref: library/ipaddress ipaddress IPv6Network num_addresses7215424 Ref: 2c6f7215424 Ref: library/ipaddress ipaddress IPv6Network prefixlen7215459 Ref: 2c707215459 Ref: library/ipaddress ipaddress IPv6Network hosts7215490 Ref: 2c717215490 Ref: library/ipaddress ipaddress IPv6Network overlaps7215846 Ref: 2c727215846 Ref: library/ipaddress ipaddress IPv6Network address_exclude7215881 Ref: 2c737215881 Ref: library/ipaddress ipaddress IPv6Network subnets7215925 Ref: 2c747215925 Ref: library/ipaddress ipaddress IPv6Network supernet7215987 Ref: 2c757215987 Ref: library/ipaddress ipaddress IPv6Network subnet_of7216050 Ref: 2c767216050 Ref: library/ipaddress ipaddress IPv6Network supernet_of7216086 Ref: 2c777216086 Ref: library/ipaddress ipaddress IPv6Network compare_networks7216124 Ref: 2c787216124 Ref: library/ipaddress ipaddress IPv6Network is_site_local7216266 Ref: 2c797216266 Node: Operators<4>7216443 Ref: library/ipaddress id17216538 Ref: 2c7a7216538 Node: Logical operators7216844 Ref: library/ipaddress logical-operators7216931 Ref: 2c7b7216931 Node: Iteration<2>7217136 Ref: library/ipaddress iteration7217267 Ref: 2c7c7217267 Node: Networks as containers of addresses7218095 Ref: library/ipaddress networks-as-containers-of-addresses7218200 Ref: 2c7d7218200 Node: Interface objects7218658 Ref: library/ipaddress interface-objects7218824 Ref: 2c7e7218824 Ref: library/ipaddress ipaddress IPv4Interface7218973 Ref: 2c1b7218973 Ref: library/ipaddress ipaddress IPv4Interface ip7219390 Ref: 2c7f7219390 Ref: library/ipaddress ipaddress IPv4Interface network7219637 Ref: 2c807219637 Ref: library/ipaddress ipaddress IPv4Interface with_prefixlen7219894 Ref: 2c817219894 Ref: library/ipaddress ipaddress IPv4Interface with_netmask7220162 Ref: 2c827220162 Ref: library/ipaddress ipaddress IPv4Interface with_hostmask7220435 Ref: 2c837220435 Ref: library/ipaddress ipaddress IPv6Interface7220707 Ref: 2c1c7220707 Ref: library/ipaddress ipaddress IPv6Interface ip7221124 Ref: 2c847221124 Ref: library/ipaddress ipaddress IPv6Interface network7221148 Ref: 2c857221148 Ref: library/ipaddress ipaddress IPv6Interface with_prefixlen7221177 Ref: 2c867221177 Ref: library/ipaddress ipaddress IPv6Interface with_netmask7221213 Ref: 2c877221213 Ref: library/ipaddress ipaddress IPv6Interface with_hostmask7221247 Ref: 2c887221247 Node: Operators<5>7221421 Ref: library/ipaddress id27221487 Ref: 2c897221487 Node: Logical operators<2>7221749 Ref: library/ipaddress id37221818 Ref: 2c8a7221818 Node: Other Module Level Functions7222475 Ref: library/ipaddress other-module-level-functions7222636 Ref: 2c8b7222636 Ref: library/ipaddress ipaddress v4_int_to_packed7222781 Ref: 2c8c7222781 Ref: library/ipaddress ipaddress v6_int_to_packed7223255 Ref: 2c8d7223255 Ref: library/ipaddress ipaddress summarize_address_range7223564 Ref: 7997223564 Ref: library/ipaddress ipaddress collapse_addresses7224447 Ref: 79a7224447 Ref: library/ipaddress ipaddress get_mixed_type_key7225015 Ref: 2c8e7225015 Node: Custom Exceptions7225614 Ref: library/ipaddress custom-exceptions7225749 Ref: 2c8f7225749 Ref: library/ipaddress ipaddress AddressValueError7225920 Ref: 2c1f7225920 Ref: library/ipaddress ipaddress NetmaskValueError7226023 Ref: 2c447226023 Node: Multimedia Services7226127 Ref: library/mm doc7226278 Ref: 2c907226278 Ref: library/mm mmedia7226278 Ref: 2c917226278 Ref: library/mm multimedia-services7226278 Ref: 2c927226278 Node: audioop — Manipulate raw audio data7226961 Ref: library/audioop doc7227106 Ref: 2c937227106 Ref: library/audioop audioop-manipulate-raw-audio-data7227106 Ref: 2c947227106 Ref: library/audioop module-audioop7227106 Ref: d7227106 Ref: library/audioop audioop error7228004 Ref: 2c957228004 Ref: library/audioop audioop add7228134 Ref: 2c967228134 Ref: library/audioop audioop adpcm2lin7228465 Ref: 2c977228465 Ref: library/audioop audioop alaw2lin7228784 Ref: 2c997228784 Ref: library/audioop audioop avg7229045 Ref: 2c9a7229045 Ref: library/audioop audioop avgpp7229149 Ref: 2c9b7229149 Ref: library/audioop audioop bias7229355 Ref: 2c9c7229355 Ref: library/audioop audioop byteswap7229542 Ref: 8227229542 Ref: library/audioop audioop cross7229772 Ref: 2c9d7229772 Ref: library/audioop audioop findfactor7229905 Ref: 2c9e7229905 Ref: library/audioop audioop findfit7230316 Ref: 2c9f7230316 Ref: library/audioop audioop findmax7230926 Ref: 2ca07230926 Ref: library/audioop audioop getsample7231283 Ref: 2ca17231283 Ref: library/audioop audioop lin2adpcm7231401 Ref: 2c987231401 Ref: library/audioop audioop lin2alaw7232140 Ref: 2ca27232140 Ref: library/audioop audioop lin2lin7232464 Ref: 2ca37232464 Ref: library/audioop audioop lin2ulaw7233092 Ref: 2ca47233092 Ref: library/audioop audioop max7233416 Ref: 2ca57233416 Ref: library/audioop audioop maxpp7233545 Ref: 2ca67233545 Ref: library/audioop audioop minmax7233656 Ref: 2ca77233656 Ref: library/audioop audioop mul7233813 Ref: 2ca87233813 Ref: library/audioop audioop ratecv7234039 Ref: 2ca97234039 Ref: library/audioop audioop reverse7234617 Ref: 2caa7234617 Ref: library/audioop audioop rms7234746 Ref: 2cab7234746 Ref: library/audioop audioop tomono7234935 Ref: 2cac7234935 Ref: library/audioop audioop tostereo7235197 Ref: 2cad7235197 Ref: library/audioop audioop ulaw2lin7235512 Ref: 2cae7235512 Node: aifc — Read and write AIFF and AIFC files7238247 Ref: library/aifc doc7238438 Ref: 2caf7238438 Ref: library/aifc aifc-read-and-write-aiff-and-aifc-files7238438 Ref: 2cb07238438 Ref: library/aifc module-aifc7238438 Ref: 57238438 Ref: library/aifc aifc open7239709 Ref: 45b7239709 Ref: library/aifc aifc aifc getnchannels7240768 Ref: 2cb17240768 Ref: library/aifc aifc aifc getsampwidth7240872 Ref: 2cb27240872 Ref: library/aifc aifc aifc getframerate7240960 Ref: 2cb37240960 Ref: library/aifc aifc aifc getnframes7241062 Ref: 2cb47241062 Ref: library/aifc aifc aifc getcomptype7241147 Ref: 2cb57241147 Ref: library/aifc aifc aifc getcompname7241342 Ref: 2cb67241342 Ref: library/aifc aifc aifc getparams7241571 Ref: 81b7241571 Ref: library/aifc aifc aifc getmarkers7241773 Ref: 2cb77241773 Ref: library/aifc aifc aifc getmark7242092 Ref: 2cb87242092 Ref: library/aifc aifc aifc readframes7242227 Ref: 2cb97242227 Ref: library/aifc aifc aifc rewind7242444 Ref: 2cba7242444 Ref: library/aifc aifc aifc setpos7242575 Ref: 2cbb7242575 Ref: library/aifc aifc aifc tell7242648 Ref: 2cbc7242648 Ref: library/aifc aifc aifc close7242713 Ref: 81c7242713 Ref: library/aifc aifc aifc aiff7243265 Ref: 2cbd7243265 Ref: library/aifc aifc aifc aifc7243469 Ref: 2cbe7243469 Ref: library/aifc aifc aifc setnchannels7243675 Ref: 2cbf7243675 Ref: library/aifc aifc aifc setsampwidth7243774 Ref: 2cc07243774 Ref: library/aifc aifc aifc setframerate7243863 Ref: 2cc17243863 Ref: library/aifc aifc aifc setnframes7243960 Ref: 2cc27243960 Ref: library/aifc aifc aifc setcomptype7244174 Ref: 2cc37244174 Ref: library/aifc aifc aifc setparams7244661 Ref: 2cc47244661 Ref: library/aifc aifc aifc setmark7244999 Ref: 2cc57244999 Ref: library/aifc aifc aifc writeframes7245353 Ref: 81e7245353 Ref: library/aifc aifc aifc writeframesraw7245597 Ref: 81d7245597 Ref: aifc — Read and write AIFF and AIFC files-Footnote-17246065 Node: sunau — Read and write Sun AU files7246128 Ref: library/sunau doc7246315 Ref: 2cc67246315 Ref: library/sunau module-sunau7246315 Ref: fa7246315 Ref: library/sunau sunau-read-and-write-sun-au-files7246315 Ref: 2cc77246315 Ref: library/sunau sunau open7247861 Ref: 4727247861 Ref: library/sunau sunau openfp7248316 Ref: 4717248316 Ref: library/sunau sunau Error7248571 Ref: 2cc87248571 Ref: library/sunau sunau AUDIO_FILE_MAGIC7248772 Ref: 2cc97248772 Ref: library/sunau sunau AUDIO_FILE_ENCODING_MULAW_87248955 Ref: 2cca7248955 Ref: library/sunau sunau AUDIO_FILE_ENCODING_LINEAR_87248999 Ref: 2ccb7248999 Ref: library/sunau sunau AUDIO_FILE_ENCODING_LINEAR_167249044 Ref: 2ccc7249044 Ref: library/sunau sunau AUDIO_FILE_ENCODING_LINEAR_247249090 Ref: 2ccd7249090 Ref: library/sunau sunau AUDIO_FILE_ENCODING_LINEAR_327249136 Ref: 2cce7249136 Ref: library/sunau sunau AUDIO_FILE_ENCODING_ALAW_87249182 Ref: 2ccf7249182 Ref: library/sunau sunau AUDIO_FILE_ENCODING_FLOAT7249321 Ref: 2cd07249321 Ref: library/sunau sunau AUDIO_FILE_ENCODING_DOUBLE7249363 Ref: 2cd17249363 Ref: library/sunau sunau AUDIO_FILE_ENCODING_ADPCM_G7217249406 Ref: 2cd27249406 Ref: library/sunau sunau AUDIO_FILE_ENCODING_ADPCM_G7227249453 Ref: 2cd37249453 Ref: library/sunau sunau AUDIO_FILE_ENCODING_ADPCM_G723_37249500 Ref: 2cd47249500 Ref: library/sunau sunau AUDIO_FILE_ENCODING_ADPCM_G723_57249549 Ref: 2cd57249549 Ref: sunau — Read and write Sun AU files-Footnote-17249807 Node: AU_read Objects7249871 Ref: library/sunau au-read-objects7249985 Ref: 2cd67249985 Ref: library/sunau id17249985 Ref: 2cd77249985 Ref: library/sunau sunau AU_read close7250123 Ref: 2cd87250123 Ref: library/sunau sunau AU_read getnchannels7250259 Ref: 2cd97250259 Ref: library/sunau sunau AU_read getsampwidth7250363 Ref: 2cda7250363 Ref: library/sunau sunau AU_read getframerate7250437 Ref: 2cdb7250437 Ref: library/sunau sunau AU_read getnframes7250508 Ref: 2cdc7250508 Ref: library/sunau sunau AU_read getcomptype7250581 Ref: 2cdd7250581 Ref: library/sunau sunau AU_read getcompname7250732 Ref: 2cde7250732 Ref: library/sunau sunau AU_read getparams7250965 Ref: 2cdf7250965 Ref: library/sunau sunau AU_read readframes7251170 Ref: 2ce07251170 Ref: library/sunau sunau AU_read rewind7251409 Ref: 2ce17251409 Ref: library/sunau sunau AU_read setpos7251641 Ref: 2ce27251641 Ref: library/sunau sunau AU_read tell7251807 Ref: 2ce37251807 Ref: library/sunau sunau AU_read getmarkers7252091 Ref: 2ce47252091 Ref: library/sunau sunau AU_read getmark7252152 Ref: 2ce57252152 Node: AU_write Objects7252208 Ref: library/sunau au-write-objects7252322 Ref: 2ce67252322 Ref: library/sunau id27252322 Ref: 2ce77252322 Ref: library/sunau sunau AU_write setnchannels7252463 Ref: 2ce87252463 Ref: library/sunau sunau AU_write setsampwidth7252536 Ref: 8de7252536 Ref: library/sunau sunau AU_write setframerate7252678 Ref: 2ce97252678 Ref: library/sunau sunau AU_write setnframes7252743 Ref: 2cea7252743 Ref: library/sunau sunau AU_write setcomptype7252882 Ref: 2ceb7252882 Ref: library/sunau sunau AU_write setparams7253043 Ref: 2cec7253043 Ref: library/sunau sunau AU_write tell7253259 Ref: 2ced7253259 Ref: library/sunau sunau AU_write writeframesraw7253446 Ref: 8df7253446 Ref: library/sunau sunau AU_write writeframes7253632 Ref: 8e07253632 Ref: library/sunau sunau AU_write close7253820 Ref: 2cee7253820 Node: wave — Read and write WAV files7254060 Ref: library/wave doc7254235 Ref: 2cef7254235 Ref: library/wave module-wave7254235 Ref: 1277254235 Ref: library/wave wave-read-and-write-wav-files7254235 Ref: 2cf07254235 Ref: library/wave wave open7254665 Ref: 4767254665 Ref: library/wave wave openfp7255716 Ref: 4757255716 Ref: library/wave wave Error7255908 Ref: 2cf37255908 Ref: wave — Read and write WAV files-Footnote-17256162 Node: Wave_read Objects7256225 Ref: library/wave id17256339 Ref: 2cf47256339 Ref: library/wave wave-read-objects7256339 Ref: 2cf57256339 Ref: library/wave wave Wave_read close7256476 Ref: 2cf17256476 Ref: library/wave wave Wave_read getnchannels7256662 Ref: 2cf67256662 Ref: library/wave wave Wave_read getsampwidth7256780 Ref: 2cf77256780 Ref: library/wave wave Wave_read getframerate7256856 Ref: 2cf87256856 Ref: library/wave wave Wave_read getnframes7256929 Ref: 2cf97256929 Ref: library/wave wave Wave_read getcomptype7257004 Ref: 2cfa7257004 Ref: library/wave wave Wave_read getcompname7257116 Ref: 2cfb7257116 Ref: library/wave wave Wave_read getparams7257274 Ref: 2cfc7257274 Ref: library/wave wave Wave_read readframes7257481 Ref: 2cfd7257481 Ref: library/wave wave Wave_read rewind7257608 Ref: 2cfe7257608 Ref: library/wave wave Wave_read getmarkers7257835 Ref: 2cff7257835 Ref: library/wave wave Wave_read getmark7257898 Ref: 2d007257898 Ref: library/wave wave Wave_read setpos7258089 Ref: 2d017258089 Ref: library/wave wave Wave_read tell7258179 Ref: 2d027258179 Node: Wave_write Objects7258254 Ref: library/wave id27258368 Ref: 2d037258368 Ref: library/wave wave-write-objects7258368 Ref: 90b7258368 Ref: library/wave wave Wave_write close7259309 Ref: 2cf27259309 Ref: library/wave wave Wave_write setnchannels7259630 Ref: 2d067259630 Ref: library/wave wave Wave_write setsampwidth7259705 Ref: 2d077259705 Ref: library/wave wave Wave_write setframerate7259787 Ref: 2d087259787 Ref: library/wave wave Wave_write setnframes7259967 Ref: 2d047259967 Ref: library/wave wave Wave_write setcomptype7260217 Ref: 2d097260217 Ref: library/wave wave Wave_write setparams7260406 Ref: 2d057260406 Ref: library/wave wave Wave_write tell7260625 Ref: 2d0a7260625 Ref: library/wave wave Wave_write writeframesraw7260818 Ref: 90c7260818 Ref: library/wave wave Wave_write writeframes7261006 Ref: 90d7261006 Node: chunk — Read IFF chunked data7261579 Ref: library/chunk doc7261763 Ref: 2d0b7261763 Ref: library/chunk chunk-read-iff-chunked-data7261763 Ref: 2d0c7261763 Ref: library/chunk module-chunk7261763 Ref: 187261763 Ref: library/chunk chunk Chunk7263593 Ref: 2d0d7263593 Ref: library/chunk chunk Chunk getname7264725 Ref: 2d0e7264725 Ref: library/chunk chunk Chunk getsize7264852 Ref: 2d0f7264852 Ref: library/chunk chunk Chunk close7264923 Ref: 2d107264923 Ref: library/chunk chunk Chunk isatty7265287 Ref: 2d117265287 Ref: library/chunk chunk Chunk seek7265347 Ref: 2d127265347 Ref: library/chunk chunk Chunk tell7265789 Ref: 2d137265789 Ref: library/chunk chunk Chunk read7265870 Ref: 2d147265870 Ref: library/chunk chunk Chunk skip7266250 Ref: 2d157266250 Ref: chunk — Read IFF chunked data-Footnote-17266604 Ref: chunk — Read IFF chunked data-Footnote-27266668 Node: colorsys — Conversions between color systems7266782 Ref: library/colorsys doc7266974 Ref: 2d167266974 Ref: library/colorsys colorsys-conversions-between-color-systems7266974 Ref: 2d177266974 Ref: library/colorsys module-colorsys7266974 Ref: 207266974 Ref: library/colorsys colorsys rgb_to_yiq7267960 Ref: 2d187267960 Ref: library/colorsys colorsys yiq_to_rgb7268070 Ref: 2d197268070 Ref: library/colorsys colorsys rgb_to_hls7268180 Ref: 2d1a7268180 Ref: library/colorsys colorsys hls_to_rgb7268290 Ref: 2d1b7268290 Ref: library/colorsys colorsys rgb_to_hsv7268400 Ref: 2d1c7268400 Ref: library/colorsys colorsys hsv_to_rgb7268510 Ref: 2d1d7268510 Ref: colorsys — Conversions between color systems-Footnote-17268822 Node: imghdr — Determine the type of an image7268889 Ref: library/imghdr doc7269089 Ref: 2d1e7269089 Ref: library/imghdr imghdr-determine-the-type-of-an-image7269089 Ref: 2d1f7269089 Ref: library/imghdr module-imghdr7269089 Ref: 997269089 Ref: library/imghdr imghdr what7269452 Ref: 6ed7269452 Ref: library/imghdr imghdr tests7271173 Ref: 2d207271173 Ref: imghdr — Determine the type of an image-Footnote-17271691 Node: sndhdr — Determine type of sound file7271756 Ref: library/sndhdr doc7271964 Ref: 2d217271964 Ref: library/sndhdr module-sndhdr7271964 Ref: ee7271964 Ref: library/sndhdr sndhdr-determine-type-of-sound-file7271964 Ref: 2d227271964 Ref: library/sndhdr sndhdr what7273208 Ref: 7477273208 Ref: library/sndhdr sndhdr whathdr7273526 Ref: 7487273526 Ref: sndhdr — Determine type of sound file-Footnote-17273909 Node: ossaudiodev — Access to OSS-compatible audio devices7273974 Ref: library/ossaudiodev doc7274132 Ref: 2d237274132 Ref: library/ossaudiodev module-ossaudiodev7274132 Ref: c67274132 Ref: library/ossaudiodev ossaudiodev-access-to-oss-compatible-audio-devices7274132 Ref: 2d247274132 Ref: library/ossaudiodev ossaudiodev OSSAudioError7275017 Ref: 2d257275017 Ref: library/ossaudiodev ossaudiodev open7275536 Ref: 2d267275536 Ref: library/ossaudiodev ossaudiodev openmixer7276935 Ref: 2d277276935 Ref: ossaudiodev — Access to OSS-compatible audio devices-Footnote-17277373 Node: Audio Device Objects7277421 Ref: library/ossaudiodev audio-device-objects7277561 Ref: 2d287277561 Ref: library/ossaudiodev ossaudio-device-objects7277561 Ref: 2d297277561 Ref: library/ossaudiodev ossaudiodev oss_audio_device close7278153 Ref: 2d2a7278153 Ref: library/ossaudiodev ossaudiodev oss_audio_device fileno7278377 Ref: 2d2b7278377 Ref: library/ossaudiodev ossaudiodev oss_audio_device read7278478 Ref: 2d2c7278478 Ref: library/ossaudiodev ossaudiodev oss_audio_device write7278786 Ref: 2d2d7278786 Ref: library/ossaudiodev ossaudiodev oss_audio_device writeall7279306 Ref: 2d2e7279306 Ref: library/ossaudiodev ossaudiodev oss_audio_device nonblock7280468 Ref: 2d2f7280468 Ref: library/ossaudiodev ossaudiodev oss_audio_device getfmts7280635 Ref: 2d307280635 Ref: library/ossaudiodev ossaudiodev oss_audio_device setfmt7282805 Ref: 2d317282805 Ref: library/ossaudiodev ossaudiodev oss_audio_device channels7283176 Ref: 2d327283176 Ref: library/ossaudiodev ossaudiodev oss_audio_device speed7283504 Ref: 2d337283504 Ref: library/ossaudiodev ossaudiodev oss_audio_device sync7284249 Ref: 2d347284249 Ref: library/ossaudiodev ossaudiodev oss_audio_device reset7284532 Ref: 2d357284532 Ref: library/ossaudiodev ossaudiodev oss_audio_device post7284796 Ref: 2d367284796 Ref: library/ossaudiodev ossaudiodev oss_audio_device setparameters7285209 Ref: 2d377285209 Ref: library/ossaudiodev ossaudiodev oss_audio_device bufsize7286272 Ref: 2d387286272 Ref: library/ossaudiodev ossaudiodev oss_audio_device obufcount7286372 Ref: 2d397286372 Ref: library/ossaudiodev ossaudiodev oss_audio_device obuffree7286506 Ref: 2d3a7286506 Ref: library/ossaudiodev ossaudiodev oss_audio_device closed7286731 Ref: 2d3b7286731 Ref: library/ossaudiodev ossaudiodev oss_audio_device name7286832 Ref: 2d3c7286832 Ref: library/ossaudiodev ossaudiodev oss_audio_device mode7286923 Ref: 2d3d7286923 Node: Mixer Device Objects7287038 Ref: library/ossaudiodev id17287178 Ref: 2d3e7287178 Ref: library/ossaudiodev mixer-device-objects7287178 Ref: 2d3f7287178 Ref: library/ossaudiodev ossaudiodev oss_mixer_device close7287289 Ref: 2d407287289 Ref: library/ossaudiodev ossaudiodev oss_mixer_device fileno7287490 Ref: 2d417287490 Ref: library/ossaudiodev ossaudiodev oss_mixer_device controls7287736 Ref: 2d427287736 Ref: library/ossaudiodev ossaudiodev oss_mixer_device stereocontrols7288714 Ref: 2d437288714 Ref: library/ossaudiodev ossaudiodev oss_mixer_device reccontrols7289159 Ref: 2d447289159 Ref: library/ossaudiodev ossaudiodev oss_mixer_device get7289388 Ref: 2d457289388 Ref: library/ossaudiodev ossaudiodev oss_mixer_device set7289883 Ref: 2d467289883 Ref: library/ossaudiodev ossaudiodev oss_mixer_device get_recsrc7290446 Ref: 2d477290446 Ref: library/ossaudiodev ossaudiodev oss_mixer_device set_recsrc7290607 Ref: 2d487290607 Node: Internationalization7291004 Ref: library/i18n doc7291143 Ref: 2d497291143 Ref: library/i18n i18n7291143 Ref: 2d4a7291143 Ref: library/i18n internationalization7291143 Ref: 2d4b7291143 Node: gettext — Multilingual internationalization services7291598 Ref: library/gettext doc7291758 Ref: 2d4c7291758 Ref: library/gettext gettext-multilingual-internationalization-services7291758 Ref: 2d4d7291758 Ref: library/gettext module-gettext7291758 Ref: 897291758 Ref: gettext — Multilingual internationalization services-Footnote-17292735 Node: GNU gettext API7292801 Ref: library/gettext gnu-gettext-api7292931 Ref: 2d4e7292931 Ref: library/gettext gettext bindtextdomain7293475 Ref: 2d4f7293475 Ref: library/gettext gettext bind_textdomain_codeset7294047 Ref: 2977294047 Ref: library/gettext gettext textdomain7294473 Ref: 2d517294473 Ref: library/gettext gettext gettext7294719 Ref: dcd7294719 Ref: library/gettext gettext dgettext7294988 Ref: 2d527294988 Ref: library/gettext gettext ngettext7295127 Ref: 2d537295127 Ref: library/gettext gettext dngettext7295837 Ref: 2d547295837 Ref: library/gettext gettext pgettext7295991 Ref: 1cf7295991 Ref: library/gettext gettext dpgettext7296042 Ref: 2d557296042 Ref: library/gettext gettext npgettext7296102 Ref: 2d567296102 Ref: library/gettext gettext dnpgettext7296166 Ref: 2d577296166 Ref: library/gettext gettext lgettext7296531 Ref: 2937296531 Ref: library/gettext gettext ldgettext7296573 Ref: 2947296573 Ref: library/gettext gettext lngettext7296624 Ref: 2957296624 Ref: library/gettext gettext ldngettext7296679 Ref: 2967296679 Ref: GNU gettext API-Footnote-17298124 Ref: GNU gettext API-Footnote-27298612 Node: Class-based API7298677 Ref: library/gettext class-based-api7298860 Ref: 2d587298860 Ref: library/gettext gettext find7299390 Ref: 2d5a7299390 Ref: library/gettext gettext translation7300838 Ref: 29a7300838 Ref: library/gettext gettext install7302274 Ref: 29b7302274 Ref: Class-based API-Footnote-17303369 Node: The NullTranslations class7303439 Ref: library/gettext the-nulltranslations-class7303551 Ref: 2d5f7303551 Ref: library/gettext gettext NullTranslations7303996 Ref: 2d5d7303996 Ref: library/gettext gettext NullTranslations _parse7304395 Ref: 2d617304395 Ref: library/gettext gettext NullTranslations add_fallback7304706 Ref: 2d607304706 Ref: library/gettext gettext NullTranslations gettext7304969 Ref: 2d627304969 Ref: library/gettext gettext NullTranslations ngettext7305167 Ref: 2d637305167 Ref: library/gettext gettext NullTranslations pgettext7305419 Ref: 2d647305419 Ref: library/gettext gettext NullTranslations npgettext7305677 Ref: 2d657305677 Ref: library/gettext gettext NullTranslations lgettext7305950 Ref: 2d5b7305950 Ref: library/gettext gettext NullTranslations lngettext7305987 Ref: 2d5c7305987 Ref: library/gettext gettext NullTranslations info7306563 Ref: 2d667306563 Ref: library/gettext gettext NullTranslations charset7306731 Ref: 2d677306731 Ref: library/gettext gettext NullTranslations output_charset7306820 Ref: 2987306820 Ref: library/gettext gettext NullTranslations set_output_charset7307062 Ref: 2997307062 Ref: library/gettext gettext NullTranslations install7307250 Ref: 2d5e7307250 Node: The GNUTranslations class7308489 Ref: library/gettext the-gnutranslations-class7308641 Ref: 2d687308641 Ref: library/gettext gettext GNUTranslations7310151 Ref: 2d597310151 Ref: library/gettext gettext GNUTranslations gettext7310271 Ref: 2d697310271 Ref: library/gettext gettext GNUTranslations ngettext7310680 Ref: 2d6a7310680 Ref: library/gettext gettext GNUTranslations pgettext7311604 Ref: 2d6b7311604 Ref: library/gettext gettext GNUTranslations npgettext7312080 Ref: 2d6c7312080 Ref: library/gettext gettext GNUTranslations lgettext7312691 Ref: 2d6d7312691 Ref: library/gettext gettext GNUTranslations lngettext7312728 Ref: 2d6e7312728 Ref: The GNUTranslations class-Footnote-17313298 Node: Solaris message catalog support7313346 Ref: library/gettext solaris-message-catalog-support7313495 Ref: 2d6f7313495 Node: The Catalog constructor7313744 Ref: library/gettext the-catalog-constructor7313859 Ref: 2d707313859 Node: Internationalizing your programs and modules7314517 Ref: library/gettext internationalizing-your-programs-and-modules7314704 Ref: 2d717314704 Ref: Internationalizing your programs and modules-Footnote-17318282 Ref: Internationalizing your programs and modules-Footnote-27318314 Node: Localizing your module7318357 Ref: library/gettext localizing-your-module7318496 Ref: 2d727318496 Node: Localizing your application7319091 Ref: library/gettext localizing-your-application7319268 Ref: 2d737319268 Node: Changing languages on the fly7319996 Ref: library/gettext changing-languages-on-the-fly7320172 Ref: 2d747320172 Node: Deferred translations7320851 Ref: library/gettext deferred-translations7320991 Ref: 2d757320991 Node: Acknowledgements<9>7323230 Ref: library/gettext acknowledgements7323393 Ref: 2d767323393 Node: locale — Internationalization services7323789 Ref: library/locale doc7323949 Ref: 2d777323949 Ref: library/locale locale-internationalization-services7323949 Ref: 2d787323949 Ref: library/locale module-locale7323949 Ref: a97323949 Ref: library/locale locale Error7324677 Ref: 2d797324677 Ref: library/locale locale setlocale7324804 Ref: 1ce57324804 Ref: library/locale locale localeconv7325991 Ref: 48a7325991 Ref: library/locale locale nl_langinfo7334292 Ref: 2d7d7334292 Ref: library/locale locale CODESET7334813 Ref: 2d7e7334813 Ref: library/locale locale D_T_FMT7334947 Ref: 2d7f7334947 Ref: library/locale locale D_FMT7335143 Ref: 2d807335143 Ref: library/locale locale T_FMT7335330 Ref: 2d817335330 Ref: library/locale locale T_FMT_AMPM7335517 Ref: 2d827335517 Ref: library/locale locale RADIXCHAR7336215 Ref: 2d837336215 Ref: library/locale locale THOUSEP7336319 Ref: 2d847336319 Ref: library/locale locale YESEXPR7336439 Ref: 2d857336439 Ref: library/locale locale NOEXPR7336823 Ref: 2d867336823 Ref: library/locale locale CRNCYSTR7337008 Ref: 2d877337008 Ref: library/locale locale ERA7337286 Ref: 2d887337286 Ref: library/locale locale ERA_D_T_FMT7338060 Ref: 2d897338060 Ref: library/locale locale ERA_D_FMT7338231 Ref: 2d8a7338231 Ref: library/locale locale ERA_T_FMT7338393 Ref: 2d8b7338393 Ref: library/locale locale ALT_DIGITS7338555 Ref: 2d8c7338555 Ref: library/locale locale getdefaultlocale7338689 Ref: ffc7338689 Ref: library/locale locale getlocale7339896 Ref: 15a37339896 Ref: library/locale locale getpreferredencoding7340373 Ref: 3a57340373 Ref: library/locale locale normalize7341241 Ref: 2d8f7341241 Ref: library/locale locale resetlocale7341663 Ref: 2d907341663 Ref: library/locale locale strcoll7341912 Ref: 2d917341912 Ref: library/locale locale strxfrm7342231 Ref: 2d937342231 Ref: library/locale locale format_string7342575 Ref: 3a47342575 Ref: library/locale locale format7343271 Ref: 4687343271 Ref: library/locale locale currency7343747 Ref: 2d947343747 Ref: library/locale locale str7344377 Ref: 2d957344377 Ref: library/locale locale delocalize7344566 Ref: 70b7344566 Ref: library/locale locale atof7344744 Ref: 2d967344744 Ref: library/locale locale atoi7344885 Ref: 2d977344885 Ref: library/locale locale LC_CTYPE7345016 Ref: 2d8e7345016 Ref: library/locale locale LC_COLLATE7345238 Ref: 2d927345238 Ref: library/locale locale LC_TIME7345431 Ref: 2d987345431 Ref: library/locale locale LC_MONETARY7345581 Ref: 2d7c7345581 Ref: library/locale locale LC_MESSAGES7345754 Ref: 2d997345754 Ref: library/locale locale LC_NUMERIC7346052 Ref: 2d7a7346052 Ref: library/locale locale LC_ALL7346368 Ref: 2d8d7346368 Ref: library/locale locale CHAR_MAX7346793 Ref: 2d7b7346793 Ref: locale — Internationalization services-Footnote-17347644 Ref: locale — Internationalization services-Footnote-27347709 Ref: locale — Internationalization services-Footnote-37347758 Node: Background details hints tips and caveats7347807 Ref: library/locale background-details-hints-tips-and-caveats7347986 Ref: 2d9a7347986 Node: For extension writers and programs that embed Python7350184 Ref: library/locale embedding-locale7350398 Ref: 2d9b7350398 Ref: library/locale for-extension-writers-and-programs-that-embed-python7350398 Ref: 2d9c7350398 Node: Access to message catalogs7351196 Ref: library/locale access-to-message-catalogs7351360 Ref: 2d9d7351360 Ref: library/locale locale-gettext7351360 Ref: 2d9e7351360 Ref: library/locale locale gettext7351433 Ref: 2d9f7351433 Ref: library/locale locale dgettext7351469 Ref: 2da07351469 Ref: library/locale locale dcgettext7351514 Ref: 2da17351514 Ref: library/locale locale textdomain7351570 Ref: 2da27351570 Ref: library/locale locale bindtextdomain7351612 Ref: 2da37351612 Node: Program Frameworks7352544 Ref: library/frameworks doc7352697 Ref: 2da47352697 Ref: library/frameworks frameworks7352697 Ref: 2da57352697 Ref: library/frameworks program-frameworks7352697 Ref: 2da67352697 Node: turtle — Turtle graphics7353146 Ref: library/turtle doc7353290 Ref: 2da77353290 Ref: library/turtle module-turtle7353290 Ref: 1167353290 Ref: library/turtle turtle-turtle-graphics7353290 Ref: 2da87353290 Ref: turtle — Turtle graphics-Footnote-17353907 Node: Introduction<11>7353972 Ref: library/turtle introduction7354107 Ref: 2da97354107 Node: Overview of available Turtle and Screen methods7357838 Ref: library/turtle overview-of-available-turtle-and-screen-methods7358037 Ref: 2db07358037 Node: Turtle methods7358216 Ref: library/turtle turtle-methods7358353 Ref: 2db17358353 Node: Methods of TurtleScreen/Screen7361431 Ref: library/turtle methods-of-turtlescreen-screen7361568 Ref: 2e017361568 Node: Methods of RawTurtle/Turtle and corresponding functions7362963 Ref: library/turtle methods-of-rawturtle-turtle-and-corresponding-functions7363204 Ref: 2e227363204 Node: Turtle motion7363601 Ref: library/turtle turtle-motion7363736 Ref: 2e237363736 Ref: library/turtle turtle forward7363783 Ref: 2db27363783 Ref: library/turtle turtle fd7363823 Ref: 2db37363823 Ref: library/turtle turtle back7364261 Ref: 2db67364261 Ref: library/turtle turtle bk7364298 Ref: 2db57364298 Ref: library/turtle turtle backward7364333 Ref: 2db47364333 Ref: library/turtle turtle right7364705 Ref: 2db77364705 Ref: library/turtle turtle rt7364740 Ref: 2db87364740 Ref: library/turtle turtle left7365206 Ref: 2db97365206 Ref: library/turtle turtle lt7365240 Ref: 2dba7365240 Ref: library/turtle turtle goto7365703 Ref: 2dbb7365703 Ref: library/turtle turtle setpos7365741 Ref: 2dbc7365741 Ref: library/turtle turtle setposition7365781 Ref: 2dbd7365781 Ref: library/turtle turtle setx7366548 Ref: 2dbe7366548 Ref: library/turtle turtle sety7366872 Ref: 2dbf7366872 Ref: library/turtle turtle setheading7367195 Ref: 2dc07367195 Ref: library/turtle turtle seth7367238 Ref: 2dc17367238 Ref: library/turtle turtle home7368054 Ref: 2dc27368054 Ref: library/turtle turtle circle7368481 Ref: 2dc37368481 Ref: library/turtle turtle dot7369866 Ref: 2dc47369866 Ref: library/turtle turtle stamp7370416 Ref: 2dc57370416 Ref: library/turtle turtle clearstamp7370755 Ref: 2dc67370755 Ref: library/turtle turtle clearstamps7371265 Ref: 2dc77371265 Ref: library/turtle turtle undo7371845 Ref: 2dc87371845 Ref: library/turtle turtle speed7372170 Ref: 2dc97372170 Node: Tell Turtle’s state7373169 Ref: library/turtle tell-turtle-s-state7373337 Ref: 2e257373337 Ref: library/turtle turtle position7373398 Ref: 2dca7373398 Ref: library/turtle turtle pos7373431 Ref: 2dcb7373431 Ref: library/turtle turtle towards7373603 Ref: 2dcc7373603 Ref: library/turtle turtle xcor7374168 Ref: 2dcd7374168 Ref: library/turtle turtle ycor7374448 Ref: 2dce7374448 Ref: library/turtle turtle heading7374735 Ref: 2dcf7374735 Ref: library/turtle turtle distance7374983 Ref: 2dd07374983 Node: Settings for measurement7375572 Ref: library/turtle settings-for-measurement7375738 Ref: 2e267375738 Ref: library/turtle turtle degrees7375807 Ref: 2dd17375807 Ref: library/turtle turtle radians7376435 Ref: 2dd27376435 Node: Pen control7376760 Ref: library/turtle pen-control7376917 Ref: 2e277376917 Node: Drawing state7377043 Ref: library/turtle drawing-state7377126 Ref: 2e287377126 Ref: library/turtle turtle pendown7377175 Ref: 2dd37377175 Ref: library/turtle turtle pd7377207 Ref: 2dd47377207 Ref: library/turtle turtle down7377234 Ref: 2dd57377234 Ref: library/turtle turtle penup7377313 Ref: 2dd67377313 Ref: library/turtle turtle pu7377343 Ref: 2dd77377343 Ref: library/turtle turtle up7377370 Ref: 2dd87377370 Ref: library/turtle turtle pensize7377448 Ref: 2dd97377448 Ref: library/turtle turtle width7377490 Ref: 2dda7377490 Ref: library/turtle turtle pen7377952 Ref: 2ddb7377952 Ref: library/turtle turtle isdown7379862 Ref: 2ddc7379862 Node: Color control7380112 Ref: library/turtle color-control7380211 Ref: 2e297380211 Ref: library/turtle turtle pencolor7380260 Ref: 2dde7380260 Ref: library/turtle turtle fillcolor7381881 Ref: 2ddf7381881 Ref: library/turtle turtle color7383400 Ref: 2ddd7383400 Node: Filling7384604 Ref: library/turtle filling7384710 Ref: 2e2a7384710 Ref: library/turtle turtle filling7384747 Ref: 2de07384747 Ref: library/turtle turtle begin_fill7385011 Ref: 2de17385011 Ref: library/turtle turtle end_fill7385108 Ref: 2de27385108 Node: More drawing control7385655 Ref: library/turtle more-drawing-control7385739 Ref: 2e2b7385739 Ref: library/turtle turtle write7386454 Ref: 2de57386454 Node: Turtle state7387233 Ref: library/turtle turtle-state7387378 Ref: 2e2c7387378 Node: Visibility7387465 Ref: library/turtle visibility7387543 Ref: 2e2d7387543 Ref: library/turtle turtle hideturtle7387586 Ref: 2de87387586 Ref: library/turtle turtle ht7387621 Ref: 2de97387621 Ref: library/turtle turtle showturtle7387878 Ref: 2de67387878 Ref: library/turtle turtle st7387913 Ref: 2de77387913 Ref: library/turtle turtle isvisible7388007 Ref: 2dea7388007 Node: Appearance7388286 Ref: library/turtle appearance7388364 Ref: 2e2e7388364 Ref: library/turtle turtle shape7388407 Ref: 2deb7388407 Ref: library/turtle turtle resizemode7389080 Ref: 2dec7389080 Ref: library/turtle turtle shapesize7390051 Ref: 2ded7390051 Ref: library/turtle turtle turtlesize7390143 Ref: 2dee7390143 Ref: library/turtle turtle shearfactor7391134 Ref: 2def7391134 Ref: library/turtle turtle tilt7391803 Ref: 2df27391803 Ref: library/turtle turtle settiltangle7392243 Ref: 2df07392243 Ref: library/turtle turtle tiltangle7392792 Ref: 2df17392792 Ref: library/turtle turtle shapetransform7393514 Ref: 2df37393514 Ref: library/turtle turtle get_shapepoly7394546 Ref: 2df47394546 Node: Using events7394917 Ref: library/turtle using-events7395073 Ref: 2e2f7395073 Ref: library/turtle turtle onrelease7395973 Ref: 2df67395973 Ref: library/turtle turtle ondrag7396984 Ref: 2df77396984 Node: Special Turtle methods7397859 Ref: library/turtle special-turtle-methods7398018 Ref: 2e307398018 Ref: library/turtle turtle begin_poly7398085 Ref: 2df87398085 Ref: library/turtle turtle end_poly7398228 Ref: 2df97398228 Ref: library/turtle turtle get_poly7398419 Ref: 2dfa7398419 Ref: library/turtle turtle clone7398821 Ref: 2dfb7398821 Ref: library/turtle turtle getturtle7399018 Ref: 2dfc7399018 Ref: library/turtle turtle getpen7399052 Ref: 2dfd7399052 Ref: library/turtle turtle getscreen7399320 Ref: 2dfe7399320 Ref: library/turtle turtle setundobuffer7399626 Ref: 2dff7399626 Ref: library/turtle turtle undobufferentries7400063 Ref: 2e007400063 Node: Compound shapes7400223 Ref: library/turtle compound-shapes7400361 Ref: 2e317400361 Ref: library/turtle compoundshapes7400361 Ref: 2e327400361 Node: Methods of TurtleScreen/Screen and corresponding functions7401388 Ref: library/turtle methods-of-turtlescreen-screen-and-corresponding-functions7401596 Ref: 2e347401596 Node: Window control7402076 Ref: library/turtle window-control7402211 Ref: 2e357402211 Ref: library/turtle turtle bgcolor7402262 Ref: 2e027402262 Ref: library/turtle turtle bgpic7402675 Ref: 2e037402675 Ref: library/turtle turtle clear7403279 Ref: 2de47403279 Ref: library/turtle turtle clearscreen7403309 Ref: 2e047403309 Ref: library/turtle turtle reset7403791 Ref: 2de37403791 Ref: library/turtle turtle resetscreen7403821 Ref: 2e057403821 Ref: library/turtle turtle screensize7404157 Ref: 2e067404157 Ref: library/turtle turtle setworldcoordinates7405066 Ref: 2e077405066 Node: Animation control7406048 Ref: library/turtle animation-control7406211 Ref: 2e367406211 Ref: library/turtle turtle delay7406268 Ref: 2e087406268 Ref: library/turtle turtle tracer7406707 Ref: 2e097406707 Ref: library/turtle turtle update7407408 Ref: 2e0a7407408 Node: Using screen events7407580 Ref: library/turtle using-screen-events7407742 Ref: 2e377407742 Ref: library/turtle turtle listen7407803 Ref: 2e0b7407803 Ref: library/turtle turtle onkey7408038 Ref: 2e0c7408038 Ref: library/turtle turtle onkeyrelease7408076 Ref: 2e0d7408076 Ref: library/turtle turtle onkeypress7408698 Ref: 2e0e7408698 Ref: library/turtle turtle onclick7409301 Ref: 2df57409301 Ref: library/turtle turtle onscreenclick7409353 Ref: 2e0f7409353 Ref: library/turtle turtle ontimer7410541 Ref: 2e107410541 Ref: library/turtle turtle mainloop7411025 Ref: 2e117411025 Ref: library/turtle turtle done7411058 Ref: 2e127411058 Node: Input methods7411384 Ref: library/turtle input-methods7411557 Ref: 2e387411557 Ref: library/turtle turtle textinput7411606 Ref: 2e1c7411606 Ref: library/turtle turtle numinput7412060 Ref: 2e1d7412060 Node: Settings and special methods7412980 Ref: library/turtle settings-and-special-methods7413192 Ref: 2e397413192 Ref: library/turtle turtle mode7413271 Ref: 2e137413271 Ref: library/turtle turtle colormode7414500 Ref: 2e147414500 Ref: library/turtle turtle getcanvas7415140 Ref: 2e157415140 Ref: library/turtle turtle getshapes7415391 Ref: 2e167415391 Ref: library/turtle turtle register_shape7415585 Ref: 2e177415585 Ref: library/turtle turtle addshape7415640 Ref: 2e187415640 Ref: library/turtle turtle turtles7416589 Ref: 2e197416589 Ref: library/turtle turtle window_height7416755 Ref: 2e1a7416755 Ref: library/turtle turtle window_width7416892 Ref: 2e1b7416892 Node: Methods specific to Screen not inherited from TurtleScreen7417026 Ref: library/turtle methods-specific-to-screen-not-inherited-from-turtlescreen7417216 Ref: 2e3a7417216 Ref: library/turtle screenspecific7417216 Ref: 2e3b7417216 Ref: library/turtle turtle bye7417357 Ref: 2e1e7417357 Ref: library/turtle turtle exitonclick7417424 Ref: 2e1f7417424 Ref: library/turtle turtle setup7417864 Ref: 2e207417864 Ref: library/turtle turtle title7419184 Ref: 2e217419184 Node: Public classes7419450 Ref: library/turtle public-classes7419625 Ref: 2e3c7419625 Ref: library/turtle turtle RawTurtle7419676 Ref: 2dad7419676 Ref: library/turtle turtle RawPen7419713 Ref: 2dae7419713 Ref: library/turtle turtle Turtle7419984 Ref: 2daf7419984 Ref: library/turtle turtle TurtleScreen7420176 Ref: 2daa7420176 Ref: library/turtle turtle Screen7420363 Ref: 2dac7420363 Ref: library/turtle turtle ScrolledCanvas7420458 Ref: 2dab7420458 Ref: library/turtle turtle Shape7420753 Ref: 2e337420753 Ref: library/turtle turtle Shape addcomponent7421561 Ref: 2e3d7421561 Ref: library/turtle turtle Vec2D7422161 Ref: 2e247422161 Node: Help and configuration7422713 Ref: library/turtle help-and-configuration7422857 Ref: 2e3e7422857 Node: How to use help7423049 Ref: library/turtle how-to-use-help7423182 Ref: 2e3f7423182 Node: Translation of docstrings into different languages7425512 Ref: library/turtle translation-of-docstrings-into-different-languages7425689 Ref: 2e407425689 Ref: library/turtle turtle write_docstringdict7425993 Ref: 2e417425993 Node: How to configure Screen and Turtles7427032 Ref: library/turtle how-to-configure-screen-and-turtles7427185 Ref: 2e427427185 Node: turtledemo — Demo scripts7429968 Ref: library/turtle module-turtledemo7430122 Ref: 1177430122 Ref: library/turtle turtledemo-demo-scripts7430122 Ref: 2e437430122 Node: Changes since Python 2 67435765 Ref: library/turtle changes-since-python-2-67435921 Ref: 2e447435921 Node: Changes since Python 3 07436896 Ref: library/turtle changes-since-python-3-07437016 Ref: 2e457437016 Node: cmd — Support for line-oriented command interpreters7438223 Ref: library/cmd doc7438409 Ref: 2e467438409 Ref: library/cmd cmd-support-for-line-oriented-command-interpreters7438409 Ref: 2e477438409 Ref: library/cmd module-cmd7438409 Ref: 1a7438409 Ref: library/cmd cmd Cmd7438885 Ref: 2e487438885 Ref: cmd — Support for line-oriented command interpreters-Footnote-17440078 Node: Cmd Objects7440140 Ref: library/cmd cmd-objects7440262 Ref: 2e4a7440262 Ref: library/cmd id17440262 Ref: 2e4b7440262 Ref: library/cmd cmd Cmd cmdloop7440361 Ref: 2e4c7440361 Ref: library/cmd cmd Cmd onecmd7442924 Ref: 2e4f7442924 Ref: library/cmd cmd Cmd emptyline7443515 Ref: 2e527443515 Ref: library/cmd cmd Cmd default7443713 Ref: 2e517443713 Ref: library/cmd cmd Cmd completedefault7443910 Ref: 2e537443910 Ref: library/cmd cmd Cmd precmd7444132 Ref: 2e507444132 Ref: library/cmd cmd Cmd postcmd7444611 Ref: 2e4e7444611 Ref: library/cmd cmd Cmd preloop7445244 Ref: 2e547445244 Ref: library/cmd cmd Cmd postloop7445438 Ref: 2e557445438 Ref: library/cmd cmd Cmd prompt7445722 Ref: 2e567445722 Ref: library/cmd cmd Cmd identchars7445791 Ref: 2e577445791 Ref: library/cmd cmd Cmd lastcmd7445886 Ref: 2e587445886 Ref: library/cmd cmd Cmd cmdqueue7445959 Ref: 2e597445959 Ref: library/cmd cmd Cmd intro7446210 Ref: 2e4d7446210 Ref: library/cmd cmd Cmd doc_header7446364 Ref: 2e5a7446364 Ref: library/cmd cmd Cmd misc_header7446484 Ref: 2e5b7446484 Ref: library/cmd cmd Cmd undoc_header7446703 Ref: 2e5c7446703 Ref: library/cmd cmd Cmd ruler7446919 Ref: 2e5d7446919 Ref: library/cmd cmd Cmd use_rawinput7447093 Ref: 2e497447093 Node: Cmd Example7447550 Ref: library/cmd cmd-example7447672 Ref: 2e5e7447672 Ref: library/cmd id27447672 Ref: 2e5f7447672 Node: shlex — Simple lexical analysis7453015 Ref: library/shlex doc7453166 Ref: 2e607453166 Ref: library/shlex module-shlex7453166 Ref: e87453166 Ref: library/shlex shlex-simple-lexical-analysis7453166 Ref: 2e617453166 Ref: library/shlex shlex split7453687 Ref: 2187453687 Ref: library/shlex shlex join7454342 Ref: 2177454342 Ref: library/shlex shlex quote7454798 Ref: a737454798 Ref: library/shlex shlex shlex7456100 Ref: 57a7456100 Ref: shlex — Simple lexical analysis-Footnote-17458346 Node: shlex Objects7458410 Ref: library/shlex id17458515 Ref: 2e657458515 Ref: library/shlex shlex-objects7458515 Ref: 2e667458515 Ref: library/shlex shlex shlex get_token7458619 Ref: 2e677458619 Ref: library/shlex shlex shlex push_token7458982 Ref: 2e687458982 Ref: library/shlex shlex shlex read_token7459064 Ref: 2e6a7459064 Ref: library/shlex shlex shlex sourcehook7459303 Ref: 2e6b7459303 Ref: library/shlex shlex shlex push_source7460843 Ref: 2e6d7460843 Ref: library/shlex shlex shlex pop_source7461146 Ref: 2e6e7461146 Ref: library/shlex shlex shlex error_leader7461345 Ref: 2e6f7461345 Ref: library/shlex shlex shlex commenters7462074 Ref: 2e627462074 Ref: library/shlex shlex shlex wordchars7462296 Ref: 2e647462296 Ref: library/shlex shlex shlex whitespace7462992 Ref: 2e727462992 Ref: library/shlex shlex shlex escape7463190 Ref: 2e737463190 Ref: library/shlex shlex shlex quotes7463355 Ref: 2e747463355 Ref: library/shlex shlex shlex escapedquotes7463640 Ref: 2e757463640 Ref: library/shlex shlex shlex whitespace_split7463869 Ref: 2e717463869 Ref: library/shlex shlex shlex infile7464407 Ref: 2e637464407 Ref: library/shlex shlex shlex instream7464638 Ref: 2e767464638 Ref: library/shlex shlex shlex source7464763 Ref: 2e6c7464763 Ref: library/shlex shlex shlex debug7465353 Ref: 2e777465353 Ref: library/shlex shlex shlex lineno7465617 Ref: 2e787465617 Ref: library/shlex shlex shlex token7465713 Ref: 2e797465713 Ref: library/shlex shlex shlex eof7465830 Ref: 2e697465830 Ref: library/shlex shlex shlex punctuation_chars7466006 Ref: 2e707466006 Node: Parsing Rules7466415 Ref: library/shlex parsing-rules7466563 Ref: 2e7a7466563 Ref: library/shlex shlex-parsing-rules7466563 Ref: 2e7b7466563 Node: Improved Compatibility with Shells7468582 Ref: library/shlex improved-compatibility-with-shells7468708 Ref: 2e7c7468708 Ref: library/shlex improved-shell-compatibility7468708 Ref: 57b7468708 Node: Graphical User Interfaces with Tk7471552 Ref: library/tk doc7471702 Ref: 2e7d7471702 Ref: library/tk graphical-user-interfaces-with-tk7471702 Ref: 2e7e7471702 Ref: library/tk tkinter7471702 Ref: 2e7f7471702 Node: tkinter — Python interface to Tcl/Tk7473433 Ref: library/tkinter doc7473583 Ref: 2e817473583 Ref: library/tkinter module-tkinter7473583 Ref: 10c7473583 Ref: library/tkinter tkinter-python-interface-to-tcl-tk7473583 Ref: 2e827473583 Ref: tkinter — Python interface to Tcl/Tk-Footnote-17476018 Ref: tkinter — Python interface to Tcl/Tk-Footnote-27476094 Ref: tkinter — Python interface to Tcl/Tk-Footnote-37476139 Ref: tkinter — Python interface to Tcl/Tk-Footnote-47476170 Ref: tkinter — Python interface to Tcl/Tk-Footnote-57476210 Ref: tkinter — Python interface to Tcl/Tk-Footnote-67476249 Ref: tkinter — Python interface to Tcl/Tk-Footnote-77476300 Ref: tkinter — Python interface to Tcl/Tk-Footnote-87476386 Ref: tkinter — Python interface to Tcl/Tk-Footnote-97476455 Ref: tkinter — Python interface to Tcl/Tk-Footnote-107476512 Ref: tkinter — Python interface to Tcl/Tk-Footnote-117476545 Ref: tkinter — Python interface to Tcl/Tk-Footnote-127476569 Ref: tkinter — Python interface to Tcl/Tk-Footnote-137476629 Node: Tkinter Modules7476666 Ref: library/tkinter tkinter-modules7476787 Ref: 2e837476787 Ref: library/tkinter tkinter Tk7477634 Ref: 2e847477634 Ref: library/tkinter tkinter Tcl7477952 Ref: 2e857477952 Node: Tkinter Life Preserver7479492 Ref: library/tkinter tkinter-life-preserver7479649 Ref: 2e867479649 Node: How To Use This Section7480543 Ref: library/tkinter how-to-use-this-section7480662 Ref: 2e877480662 Node: A Simple Hello World Program7482102 Ref: library/tkinter a-simple-hello-world-program7482221 Ref: 2e887482221 Node: A Very Quick Look at Tcl/Tk7483093 Ref: library/tkinter a-very-quick-look-at-tcl-tk7483264 Ref: 2e897483264 Node: Mapping Basic Tk into Tkinter7486617 Ref: library/tkinter mapping-basic-tk-into-tkinter7486796 Ref: 2e8b7486796 Ref: library/tkinter tkinter-basic-mapping7486796 Ref: 2e8a7486796 Node: How Tk and Tkinter are Related7488618 Ref: library/tkinter how-tk-and-tkinter-are-related7488785 Ref: 2e8d7488785 Node: Handy Reference7490057 Ref: library/tkinter handy-reference7490208 Ref: 2e8e7490208 Node: Setting Options7490460 Ref: library/tkinter setting-options7490546 Ref: 2e8f7490546 Ref: library/tkinter tkinter-setting-options7490546 Ref: 2e8c7490546 Node: The Packer7493753 Ref: library/tkinter the-packer7493862 Ref: 2e907493862 Node: Packer Options7495512 Ref: library/tkinter packer-options7495631 Ref: 2e917495631 Node: Coupling Widget Variables7496331 Ref: library/tkinter coupling-widget-variables7496458 Ref: 2e927496458 Node: The Window Manager7498660 Ref: library/tkinter the-window-manager7498793 Ref: 2e937498793 Node: Tk Option Data Types7500187 Ref: library/tkinter tk-option-data-types7500314 Ref: 2e947500314 Node: Bindings and Events7503378 Ref: library/tkinter bindings-and-events7503506 Ref: 2e957503506 Node: The index Parameter7506237 Ref: library/tkinter the-index-parameter7506351 Ref: 2e967506351 Node: Images7508286 Ref: library/tkinter images7508372 Ref: 2e977508372 Ref: Images-Footnote-17509306 Node: File Handlers7509340 Ref: library/tkinter file-handlers7509452 Ref: 2e987509452 Ref: library/tkinter tkinter-file-handlers7509452 Ref: 2e997509452 Ref: library/tkinter tkinter Widget tk createfilehandler7510394 Ref: 2e9a7510394 Ref: library/tkinter tkinter Widget tk deletefilehandler7510829 Ref: 2e9b7510829 Ref: library/tkinter tkinter READABLE7510911 Ref: 2e9c7510911 Ref: library/tkinter tkinter WRITABLE7510938 Ref: 2e9d7510938 Ref: library/tkinter tkinter EXCEPTION7510965 Ref: 2e9e7510965 Node: tkinter ttk — Tk themed widgets7511040 Ref: library/tkinter ttk doc7511239 Ref: 2e9f7511239 Ref: library/tkinter ttk module-tkinter ttk7511239 Ref: 10f7511239 Ref: library/tkinter ttk tkinter-ttk-tk-themed-widgets7511239 Ref: 2ea07511239 Ref: tkinter ttk — Tk themed widgets-Footnote-17512301 Ref: tkinter ttk — Tk themed widgets-Footnote-27512371 Node: Using Ttk7512424 Ref: library/tkinter ttk using-ttk7512523 Ref: 2ea17512523 Ref: Using Ttk-Footnote-17513680 Node: Ttk Widgets7513743 Ref: library/tkinter ttk ttk-widgets7513857 Ref: 2ea27513857 Node: Widget7514966 Ref: library/tkinter ttk widget7515079 Ref: 2ea97515079 Node: Standard Options7515396 Ref: library/tkinter ttk standard-options7515489 Ref: 2eaa7515489 Node: Scrollable Widget Options7517166 Ref: library/tkinter ttk scrollable-widget-options7517281 Ref: 2eab7517281 Node: Label Options7518404 Ref: library/tkinter ttk label-options7518524 Ref: 2eac7518524 Node: Compatibility Options7521083 Ref: library/tkinter ttk compatibility-options7521191 Ref: 2eae7521191 Node: Widget States7521727 Ref: library/tkinter ttk widget-states7521832 Ref: 2eb07521832 Node: ttk Widget7523511 Ref: library/tkinter ttk ttk-widget7523586 Ref: 2eb17523586 Ref: library/tkinter ttk tkinter ttk Widget7523773 Ref: 2ea67523773 Ref: library/tkinter ttk tkinter ttk Widget identify7523804 Ref: 2eb27523804 Ref: library/tkinter ttk tkinter ttk Widget instate7524047 Ref: 2eb37524047 Ref: library/tkinter ttk tkinter ttk Widget state7524391 Ref: 2eaf7524391 Node: Combobox7524779 Ref: library/tkinter ttk combobox7524888 Ref: 2eb47524888 Node: Options7525583 Ref: library/tkinter ttk options7525658 Ref: 2eb57525658 Node: Virtual events7528164 Ref: library/tkinter ttk virtual-events7528260 Ref: 2eb67528260 Node: ttk Combobox7528440 Ref: library/tkinter ttk ttk-combobox7528520 Ref: 2eb77528520 Ref: library/tkinter ttk tkinter ttk Combobox7528567 Ref: 2ea37528567 Ref: library/tkinter ttk tkinter ttk Combobox current7528600 Ref: 2eb87528600 Ref: library/tkinter ttk tkinter ttk Combobox get7528876 Ref: 2eb97528876 Ref: library/tkinter ttk tkinter ttk Combobox set7528955 Ref: 2eba7528955 Node: Spinbox7529039 Ref: library/tkinter ttk spinbox7529150 Ref: 2ebb7529150 Node: Options<2>7529910 Ref: library/tkinter ttk id17529990 Ref: 2ebc7529990 Node: Virtual events<2>7532376 Ref: library/tkinter ttk id27532476 Ref: 2ebd7532476 Node: ttk Spinbox7532684 Ref: library/tkinter ttk ttk-spinbox7532765 Ref: 2ebe7532765 Ref: library/tkinter ttk tkinter ttk Spinbox7532810 Ref: 3fd7532810 Ref: library/tkinter ttk tkinter ttk Spinbox get7532842 Ref: 2ebf7532842 Ref: library/tkinter ttk tkinter ttk Spinbox set7532920 Ref: 2ec07532920 Node: Notebook7533003 Ref: library/tkinter ttk notebook7533117 Ref: 2ec17533117 Node: Options<3>7533477 Ref: library/tkinter ttk id37533552 Ref: 2ec27533552 Node: Tab Options7534727 Ref: library/tkinter ttk tab-options7534826 Ref: 2ec37534826 Node: Tab Identifiers7536901 Ref: library/tkinter ttk tab-identifiers7537004 Ref: 2ec57537004 Node: Virtual Events7537538 Ref: library/tkinter ttk id47537642 Ref: 2ec77537642 Node: ttk Notebook7537786 Ref: library/tkinter ttk ttk-notebook7537866 Ref: 2ec87537866 Ref: library/tkinter ttk tkinter ttk Notebook7537913 Ref: 2ea47537913 Ref: library/tkinter ttk tkinter ttk Notebook add7537946 Ref: 2ec97537946 Ref: library/tkinter ttk tkinter ttk Notebook forget7538231 Ref: 2eca7538231 Ref: library/tkinter ttk tkinter ttk Notebook hide7538369 Ref: 2ecb7538369 Ref: library/tkinter ttk tkinter ttk Notebook identify7538679 Ref: 2ecc7538679 Ref: library/tkinter ttk tkinter ttk Notebook index7538821 Ref: 2ec67538821 Ref: library/tkinter ttk tkinter ttk Notebook insert7539000 Ref: 2ecd7539000 Ref: library/tkinter ttk tkinter ttk Notebook select7539385 Ref: 2ece7539385 Ref: library/tkinter ttk tkinter ttk Notebook tab7539699 Ref: 2ecf7539699 Ref: library/tkinter ttk tkinter ttk Notebook tabs7540045 Ref: 2ed07540045 Ref: library/tkinter ttk tkinter ttk Notebook enable_traversal7540133 Ref: 2ec47540133 Node: Progressbar7540960 Ref: library/tkinter ttk progressbar7541076 Ref: 2ed17541076 Node: Options<4>7541517 Ref: library/tkinter ttk id57541599 Ref: 2ed27541599 Node: ttk Progressbar7543474 Ref: library/tkinter ttk ttk-progressbar7543556 Ref: 2ed37543556 Ref: library/tkinter ttk tkinter ttk Progressbar7543609 Ref: 2ea57543609 Ref: library/tkinter ttk tkinter ttk Progressbar start7543645 Ref: 2ed47543645 Ref: library/tkinter ttk tkinter ttk Progressbar step7543913 Ref: 2ed57543913 Ref: library/tkinter ttk tkinter ttk Progressbar stop7544060 Ref: 2ed67544060 Node: Separator7544245 Ref: library/tkinter ttk separator7544361 Ref: 2ed77544361 Node: Options<5>7544591 Ref: library/tkinter ttk id67544647 Ref: 2ed87544647 Node: Sizegrip7545036 Ref: library/tkinter ttk sizegrip7545149 Ref: 2ed97545149 Node: Platform-specific notes7545499 Ref: library/tkinter ttk platform-specific-notes7545580 Ref: 2eda7545580 Node: Bugs7545838 Ref: library/tkinter ttk bugs7545919 Ref: 2edb7545919 Node: Treeview7546192 Ref: library/tkinter ttk treeview7546307 Ref: 2edc7546307 Node: Options<6>7547665 Ref: library/tkinter ttk id77547741 Ref: 2ee07547741 Node: Item Options7550387 Ref: library/tkinter ttk item-options7550483 Ref: 2ee17550483 Node: Tag Options7551659 Ref: library/tkinter ttk tag-options7551763 Ref: 2ee27551763 Node: Column Identifiers7552493 Ref: library/tkinter ttk column-identifiers7552602 Ref: 2edd7552602 Node: Virtual Events<2>7553474 Ref: library/tkinter ttk id87553584 Ref: 2ee37553584 Node: ttk Treeview7554486 Ref: library/tkinter ttk ttk-treeview7554569 Ref: 2ee57554569 Ref: library/tkinter ttk tkinter ttk Treeview7554616 Ref: 2bd7554616 Ref: library/tkinter ttk tkinter ttk Treeview bbox7554649 Ref: 2ee67554649 Ref: library/tkinter ttk tkinter ttk Treeview get_children7555086 Ref: 2ee77555086 Ref: library/tkinter ttk tkinter ttk Treeview set_children7555252 Ref: 2ee87555252 Ref: library/tkinter ttk tkinter ttk Treeview column7555644 Ref: 2ee97555644 Ref: library/tkinter ttk tkinter ttk Treeview delete7557054 Ref: 2eea7557054 Ref: library/tkinter ttk tkinter ttk Treeview detach7557200 Ref: 2eeb7557200 Ref: library/tkinter ttk tkinter ttk Treeview exists7557511 Ref: 2eec7557511 Ref: library/tkinter ttk tkinter ttk Treeview focus7557621 Ref: 2ee47557621 Ref: library/tkinter ttk tkinter ttk Treeview heading7557814 Ref: 2eed7557814 Ref: library/tkinter ttk tkinter ttk Treeview identify7558915 Ref: 2eee7558915 Ref: library/tkinter ttk tkinter ttk Treeview identify_row7559152 Ref: 2eef7559152 Ref: library/tkinter ttk tkinter ttk Treeview identify_column7559247 Ref: 2ef07559247 Ref: library/tkinter ttk tkinter ttk Treeview identify_region7559408 Ref: 2ef17559408 Ref: library/tkinter ttk tkinter ttk Treeview identify_element7560044 Ref: 2ef27560044 Ref: library/tkinter ttk tkinter ttk Treeview index7560172 Ref: 2ef37560172 Ref: library/tkinter ttk tkinter ttk Treeview insert7560300 Ref: 2ef47560300 Ref: library/tkinter ttk tkinter ttk Treeview item7561197 Ref: 2ef57561197 Ref: library/tkinter ttk tkinter ttk Treeview move7561575 Ref: 2ef67561575 Ref: library/tkinter ttk tkinter ttk Treeview next7562013 Ref: 2ef77562013 Ref: library/tkinter ttk tkinter ttk Treeview parent7562168 Ref: 2ef87562168 Ref: library/tkinter ttk tkinter ttk Treeview prev7562319 Ref: 2ef97562319 Ref: library/tkinter ttk tkinter ttk Treeview reattach7562479 Ref: 2efa7562479 Ref: library/tkinter ttk tkinter ttk Treeview see7562581 Ref: 2efb7562581 Ref: library/tkinter ttk tkinter ttk Treeview selection7562837 Ref: 2bc7562837 Ref: library/tkinter ttk tkinter ttk Treeview selection_set7563085 Ref: 2be7563085 Ref: library/tkinter ttk tkinter ttk Treeview selection_add7563290 Ref: 2efc7563290 Ref: library/tkinter ttk tkinter ttk Treeview selection_remove7563490 Ref: 2efd7563490 Ref: library/tkinter ttk tkinter ttk Treeview selection_toggle7563698 Ref: 2efe7563698 Ref: library/tkinter ttk tkinter ttk Treeview set7563923 Ref: 2eff7563923 Ref: library/tkinter ttk tkinter ttk Treeview tag_bind7564288 Ref: 2f007564288 Ref: library/tkinter ttk tkinter ttk Treeview tag_configure7564558 Ref: 2f017564558 Ref: library/tkinter ttk tkinter ttk Treeview tag_has7564987 Ref: 2f027564987 Ref: library/tkinter ttk tkinter ttk Treeview xview7565272 Ref: 2ede7565272 Ref: library/tkinter ttk tkinter ttk Treeview yview7565368 Ref: 2edf7565368 Node: Ttk Styling7565462 Ref: library/tkinter ttk ttk-styling7565560 Ref: 2f037565560 Ref: library/tkinter ttk ttkstyling7565560 Ref: 2ea77565560 Ref: library/tkinter ttk tkinter ttk Style7566154 Ref: 2ea87566154 Ref: library/tkinter ttk tkinter ttk Style configure7566243 Ref: 2f047566243 Ref: library/tkinter ttk tkinter ttk Style map7566970 Ref: 2ead7566970 Ref: library/tkinter ttk tkinter ttk Style lookup7568235 Ref: 2f057568235 Ref: library/tkinter ttk tkinter ttk Style layout7568756 Ref: 2f067568756 Ref: library/tkinter ttk tkinter ttk Style element_create7570068 Ref: 2f087570068 Ref: library/tkinter ttk tkinter ttk Style element_names7572190 Ref: 2f097572190 Ref: library/tkinter ttk tkinter ttk Style element_options7572295 Ref: 2f0a7572295 Ref: library/tkinter ttk tkinter ttk Style theme_create7572401 Ref: 2f0b7572401 Ref: library/tkinter ttk tkinter ttk Style theme_settings7572814 Ref: 2f0c7572814 Ref: library/tkinter ttk tkinter ttk Style theme_names7574291 Ref: 2f0d7574291 Ref: library/tkinter ttk tkinter ttk Style theme_use7574371 Ref: 2f0e7574371 Ref: Ttk Styling-Footnote-17574668 Node: Layouts7574729 Ref: library/tkinter ttk layouts7574784 Ref: 2f077574784 Node: tkinter tix — Extension widgets for Tk7576068 Ref: library/tkinter tix doc7576274 Ref: 2f0f7576274 Ref: library/tkinter tix layout7576274 Ref: 2f107576274 Ref: library/tkinter tix layouts7576274 Ref: 2f117576274 Ref: library/tkinter tix module-tkinter tix7576274 Ref: 10e7576274 Ref: library/tkinter tix tkinter-tix-extension-widgets-for-tk7576274 Ref: 2f127576274 Ref: tkinter tix — Extension widgets for Tk-Footnote-17578218 Ref: tkinter tix — Extension widgets for Tk-Footnote-27578288 Ref: tkinter tix — Extension widgets for Tk-Footnote-37578324 Ref: tkinter tix — Extension widgets for Tk-Footnote-47578377 Ref: tkinter tix — Extension widgets for Tk-Footnote-57578454 Node: Using Tix7578511 Ref: library/tkinter tix using-tix7578617 Ref: 2f197578617 Ref: library/tkinter tix tkinter tix Tk7578656 Ref: 2f1a7578656 Node: Tix Widgets7579629 Ref: library/tkinter tix tix-widgets7579756 Ref: 2f1b7579756 Ref: Tix Widgets-Footnote-17580096 Node: Basic Widgets7580174 Ref: library/tkinter tix basic-widgets7580258 Ref: 2f1c7580258 Ref: library/tkinter tix tkinter tix Balloon7580305 Ref: 2f1d7580305 Ref: library/tkinter tix tkinter tix ButtonBox7580583 Ref: 2f1e7580583 Ref: library/tkinter tix tkinter tix ComboBox7580724 Ref: 2f147580724 Ref: library/tkinter tix tkinter tix Control7580958 Ref: 2f157580958 Ref: library/tkinter tix tkinter tix LabelEntry7581271 Ref: 2f1f7581271 Ref: library/tkinter tix tkinter tix LabelFrame7581486 Ref: 2f207581486 Ref: library/tkinter tix tkinter tix Meter7581788 Ref: 2f217581788 Ref: library/tkinter tix tkinter tix OptionMenu7581941 Ref: 2f227581941 Ref: library/tkinter tix tkinter tix PopupMenu7582034 Ref: 2f237582034 Ref: library/tkinter tix tkinter tix Select7582282 Ref: 2f247582282 Ref: library/tkinter tix tkinter tix StdButtonBox7582479 Ref: 2f257582479 Ref: Basic Widgets-Footnote-17582651 Ref: Basic Widgets-Footnote-27582731 Ref: Basic Widgets-Footnote-37582813 Ref: Basic Widgets-Footnote-47582894 Ref: Basic Widgets-Footnote-57582974 Ref: Basic Widgets-Footnote-67583057 Ref: Basic Widgets-Footnote-77583140 Ref: Basic Widgets-Footnote-87583218 Ref: Basic Widgets-Footnote-97583301 Ref: Basic Widgets-Footnote-107583383 Ref: Basic Widgets-Footnote-117583463 Node: File Selectors7583549 Ref: library/tkinter tix file-selectors7583662 Ref: 2f267583662 Ref: library/tkinter tix tkinter tix DirList7583711 Ref: 2f277583711 Ref: library/tkinter tix tkinter tix DirTree7583971 Ref: 2f287583971 Ref: library/tkinter tix tkinter tix DirSelectDialog7584231 Ref: 2f297584231 Ref: library/tkinter tix tkinter tix DirSelectBox7584487 Ref: 2f2a7584487 Ref: library/tkinter tix tkinter tix ExFileSelectBox7584829 Ref: 2f2b7584829 Ref: library/tkinter tix tkinter tix FileSelectBox7585160 Ref: 2f2c7585160 Ref: library/tkinter tix tkinter tix FileEntry7585492 Ref: 2f177585492 Ref: File Selectors-Footnote-17585812 Ref: File Selectors-Footnote-27585892 Ref: File Selectors-Footnote-37585972 Ref: File Selectors-Footnote-47586060 Ref: File Selectors-Footnote-57586148 Ref: File Selectors-Footnote-67586234 Node: Hierarchical ListBox7586316 Ref: library/tkinter tix hierarchical-listbox7586431 Ref: 2f2d7586431 Ref: library/tkinter tix tkinter tix HList7586492 Ref: 2f137586492 Ref: library/tkinter tix tkinter tix CheckList7586777 Ref: 2f2e7586777 Ref: library/tkinter tix tkinter tix Tree7587065 Ref: 2f2f7587065 Ref: Hierarchical ListBox-Footnote-17587305 Ref: Hierarchical ListBox-Footnote-27587383 Ref: Hierarchical ListBox-Footnote-37587465 Node: Tabular ListBox7587542 Ref: library/tkinter tix tabular-listbox7587658 Ref: 2f307587658 Ref: library/tkinter tix tkinter tix TList7587709 Ref: 2f317587709 Ref: Tabular ListBox-Footnote-17588195 Node: Manager Widgets7588273 Ref: library/tkinter tix manager-widgets7588380 Ref: 2f327588380 Ref: library/tkinter tix tkinter tix PanedWindow7588431 Ref: 2f187588431 Ref: library/tkinter tix tkinter tix ListNoteBook7588738 Ref: 2f337588738 Ref: library/tkinter tix tkinter tix NoteBook7589189 Ref: 2f167589189 Ref: Manager Widgets-Footnote-17589600 Ref: Manager Widgets-Footnote-27589684 Ref: Manager Widgets-Footnote-37589769 Node: Image Types7589850 Ref: library/tkinter tix image-types7589963 Ref: 2f347589963 Ref: Image Types-Footnote-17590575 Ref: Image Types-Footnote-27590651 Node: Miscellaneous Widgets7590729 Ref: library/tkinter tix miscellaneous-widgets7590848 Ref: 2f357590848 Ref: library/tkinter tix tkinter tix InputOnly7590911 Ref: 2f367590911 Ref: Miscellaneous Widgets-Footnote-17591112 Node: Form Geometry Manager7591194 Ref: library/tkinter tix form-geometry-manager7591293 Ref: 2f377591293 Ref: library/tkinter tix tkinter tix Form7591439 Ref: 2f387591439 Ref: Form Geometry Manager-Footnote-17591590 Node: Tix Commands7591667 Ref: library/tkinter tix tix-commands7591776 Ref: 2f397591776 Ref: library/tkinter tix tkinter tix tixCommand7591823 Ref: 2f3a7591823 Ref: library/tkinter tix tkinter tix tixCommand tix_configure7592329 Ref: 2f3b7592329 Ref: library/tkinter tix tkinter tix tixCommand tix_cget7593014 Ref: 2f3c7593014 Ref: library/tkinter tix tkinter tix tixCommand tix_getbitmap7593189 Ref: 2f3d7593189 Ref: library/tkinter tix tkinter tix tixCommand tix_addbitmapdir7593740 Ref: 2f3e7593740 Ref: library/tkinter tix tkinter tix tixCommand tix_filedialog7594274 Ref: 2f407594274 Ref: library/tkinter tix tkinter tix tixCommand tix_getimage7594854 Ref: 2f3f7594854 Ref: library/tkinter tix tkinter tix tixCommand tix_option_get7595644 Ref: 2f417595644 Ref: library/tkinter tix tkinter tix tixCommand tix_resetoptions7595753 Ref: 2f427595753 Ref: Tix Commands-Footnote-17596586 Node: tkinter scrolledtext — Scrolled Text Widget7596658 Ref: library/tkinter scrolledtext doc7596838 Ref: 2f437596838 Ref: library/tkinter scrolledtext module-tkinter scrolledtext7596838 Ref: 10d7596838 Ref: library/tkinter scrolledtext tkinter-scrolledtext-scrolled-text-widget7596838 Ref: 2f447596838 Ref: library/tkinter scrolledtext tkinter scrolledtext ScrolledText frame7597807 Ref: 2f457597807 Ref: library/tkinter scrolledtext tkinter scrolledtext ScrolledText vbar7597907 Ref: 2f467597907 Ref: tkinter scrolledtext — Scrolled Text Widget-Footnote-17598006 Node: IDLE<3>7598086 Ref: library/idle doc7598265 Ref: 2f477598265 Ref: library/idle id17598265 Ref: 2f487598265 Ref: library/idle idle7598265 Ref: 94a7598265 Ref: IDLE<3>-Footnote-17599295 Node: Menus7599359 Ref: library/idle 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Editor7608648 Ref: library/idle options-menu-shell-and-editor7608793 Ref: 2f577608793 Node: Window menu Shell and Editor7610410 Ref: library/idle window-menu-shell-and-editor7610553 Ref: 2f5a7610553 Node: Help menu Shell and Editor7610745 Ref: library/idle help-menu-shell-and-editor7610872 Ref: 2f5b7610872 Node: Context Menus7611592 Ref: library/idle context-menus7611682 Ref: 2f5d7611682 Node: Editing and navigation7612856 Ref: library/idle editing-and-navigation7612971 Ref: 2f5e7612971 Ref: library/idle id27612971 Ref: 2f5f7612971 Node: Editor windows7613196 Ref: library/idle editor-windows7613290 Ref: 2f607613290 Node: Key bindings7613912 Ref: library/idle key-bindings7614036 Ref: 2f617614036 Node: Automatic indentation7615424 Ref: library/idle automatic-indentation7615545 Ref: 2f627615545 Node: Completions7616125 Ref: library/idle completions7616242 Ref: 2f4c7616242 Ref: library/idle id37616242 Ref: 2f637616242 Node: Calltips7618889 Ref: library/idle calltips7618997 Ref: 2f4d7618997 Ref: library/idle id47618997 Ref: 2f647618997 Node: Code Context7620623 Ref: library/idle code-context7620739 Ref: 2f597620739 Ref: library/idle id57620739 Ref: 2f657620739 Node: Python Shell window7621627 Ref: library/idle python-shell-window7621746 Ref: 2f667621746 Node: Text colors7622872 Ref: library/idle text-colors7622970 Ref: 2f677622970 Node: Startup and code execution7623733 Ref: library/idle startup-and-code-execution7623863 Ref: 2f687623863 Node: Command line usage7624994 Ref: library/idle command-line-usage7625099 Ref: 2f697625099 Node: Startup failure7626139 Ref: library/idle startup-failure7626270 Ref: 2f6a7626270 Node: Running user code7629457 Ref: library/idle running-user-code7629590 Ref: 2f6b7629590 Node: User output in Shell7632289 Ref: library/idle user-output-in-shell7632438 Ref: 2f6c7632438 Node: Developing tkinter applications7635524 Ref: library/idle developing-tkinter-applications7635684 Ref: 2f6d7635684 Node: Running without a subprocess7636933 Ref: library/idle running-without-a-subprocess7637064 Ref: 2f6e7637064 Node: Help and preferences7638446 Ref: library/idle help-and-preferences7638545 Ref: 2f6f7638545 Node: Help sources7638692 Ref: library/idle help-sources7638789 Ref: 2f5c7638789 Ref: library/idle id67638789 Ref: 2f707638789 Node: Setting preferences7639659 Ref: library/idle preferences7639778 Ref: 2f587639778 Ref: library/idle setting-preferences7639778 Ref: 2f717639778 Node: IDLE on macOS7640787 Ref: library/idle idle-on-macos7640904 Ref: 2f727640904 Node: Extensions7641171 Ref: library/idle extensions7641260 Ref: 2f737641260 Node: Other Graphical User Interface Packages7641611 Ref: library/othergui doc7641736 Ref: 2f747641736 Ref: library/othergui other-graphical-user-interface-packages7641736 Ref: 2f757641736 Ref: library/othergui other-gui-packages7641736 Ref: 2e807641736 Ref: Other Graphical User Interface Packages-Footnote-17644204 Ref: Other Graphical User Interface Packages-Footnote-27644254 Ref: Other Graphical User Interface Packages-Footnote-37644306 Ref: Other Graphical User Interface Packages-Footnote-47644335 Ref: Other Graphical User Interface Packages-Footnote-57644389 Ref: Other Graphical User Interface Packages-Footnote-67644419 Ref: Other Graphical User Interface Packages-Footnote-77644450 Ref: Other Graphical User Interface Packages-Footnote-87644505 Ref: Other Graphical User Interface Packages-Footnote-97644564 Ref: Other Graphical User Interface Packages-Footnote-107644603 Ref: Other Graphical User Interface Packages-Footnote-117644637 Ref: Other Graphical User Interface Packages-Footnote-127644673 Node: Development Tools7644726 Ref: library/development doc7644881 Ref: 2f767644881 Ref: library/development development7644881 Ref: 2f777644881 Ref: library/development development-tools7644881 Ref: 2f787644881 Node: typing — Support for type hints7646130 Ref: library/typing doc7646282 Ref: 2f797646282 Ref: library/typing module-typing7646282 Ref: 1197646282 Ref: library/typing typing-support-for-type-hints7646282 Ref: 2f7a7646282 Ref: typing — Support for type hints-Footnote-17647674 Ref: typing — Support for type hints-Footnote-27647739 Ref: typing — Support for type hints-Footnote-37647788 Ref: typing — Support for type hints-Footnote-47647837 Ref: typing — Support for type hints-Footnote-57647886 Ref: typing — Support for type hints-Footnote-67647935 Ref: typing — Support for type hints-Footnote-77647984 Ref: typing — Support for type hints-Footnote-87648033 Ref: typing — Support for type hints-Footnote-97648082 Node: Type aliases7648131 Ref: library/typing type-aliases7648229 Ref: 2f807648229 Node: NewType7649401 Ref: library/typing distinct7649516 Ref: 2f817649516 Ref: library/typing newtype7649516 Ref: 2f827649516 Ref: NewType-Footnote-17652392 Node: Callable7652441 Ref: library/typing callable7652552 Ref: 2f837652552 Node: Generics7653208 Ref: library/typing generics7653338 Ref: 2f847653338 Ref: library/typing id17653338 Ref: 2f857653338 Node: 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2f8d7667741 Ref: library/typing typing SupportsInt7667854 Ref: 2417667854 Ref: library/typing typing SupportsFloat7667938 Ref: 2f8e7667938 Ref: library/typing typing SupportsComplex7668026 Ref: 2f8f7668026 Ref: library/typing typing SupportsBytes7668118 Ref: 2f907668118 Ref: library/typing typing SupportsIndex7668206 Ref: 2427668206 Ref: library/typing typing SupportsAbs7668320 Ref: 2f917668320 Ref: library/typing typing SupportsRound7668446 Ref: 2f927668446 Ref: library/typing typing Container7668576 Ref: 2f937668576 Ref: library/typing typing Hashable7668687 Ref: 2f947668687 Ref: library/typing typing Sized7668771 Ref: 2f957668771 Ref: library/typing typing Collection7668849 Ref: 5a27668849 Ref: library/typing typing AbstractSet7669014 Ref: 2f967669014 Ref: library/typing typing MutableSet7669131 Ref: 2f977669131 Ref: library/typing typing Mapping7669245 Ref: 2f987669245 Ref: library/typing typing MutableMapping7669539 Ref: 2f997669539 Ref: library/typing typing Sequence7669661 Ref: 2f9a7669661 Ref: library/typing typing MutableSequence7669791 Ref: 2f9b7669791 Ref: library/typing typing ByteString7669911 Ref: 2f9c7669911 Ref: library/typing typing Deque7670282 Ref: 2f9d7670282 Ref: library/typing typing List7670448 Ref: 2f9e7670448 Ref: library/typing typing Set7670996 Ref: 2f9f7670996 Ref: library/typing typing FrozenSet7671246 Ref: 2fa07671246 Ref: library/typing typing MappingView7671364 Ref: 2fa17671364 Ref: library/typing typing KeysView7671487 Ref: 2fa27671487 Ref: library/typing typing ItemsView7671621 Ref: 2fa37671621 Ref: library/typing typing ValuesView7671753 Ref: 2fa47671753 Ref: library/typing typing Awaitable7671871 Ref: 2fa57671871 Ref: library/typing typing Coroutine7672009 Ref: 2fa67672009 Ref: library/typing typing AsyncIterable7672537 Ref: 2fa87672537 Ref: library/typing typing AsyncIterator7672683 Ref: 2fa97672683 Ref: library/typing typing ContextManager7672835 Ref: 5357672835 Ref: library/typing typing AsyncContextManager7673014 Ref: 2faa7673014 Ref: library/typing typing Dict7673208 Ref: 2fab7673208 Ref: library/typing typing DefaultDict7673572 Ref: 2fac7673572 Ref: library/typing typing OrderedDict7673754 Ref: 2fad7673754 Ref: library/typing typing Counter7673936 Ref: 2fae7673936 Ref: library/typing typing ChainMap7674114 Ref: 2faf7674114 Ref: library/typing typing Generator7674315 Ref: 2fa77674315 Ref: library/typing typing AsyncGenerator7675450 Ref: 2fb07675450 Ref: library/typing typing Text7676713 Ref: 2fb17676713 Ref: library/typing typing IO7677187 Ref: 2fb27677187 Ref: library/typing typing TextIO7677208 Ref: 2fb37677208 Ref: library/typing typing BinaryIO7677233 Ref: 2fb47677233 Ref: library/typing typing Pattern7677452 Ref: 2fb57677452 Ref: library/typing typing Match7677478 Ref: 2fb67677478 Ref: library/typing typing NamedTuple7677830 Ref: 2807677830 Ref: library/typing typing TypedDict7679770 Ref: 23b7679770 Ref: library/typing typing ForwardRef7681568 Ref: 2fb77681568 Ref: library/typing typing NewType7681926 Ref: 5a57681926 Ref: library/typing typing cast7682245 Ref: 2fb87682245 Ref: library/typing typing get_type_hints7682546 Ref: 30a7682546 Ref: library/typing typing get_origin7683197 Ref: 2437683197 Ref: library/typing typing get_args7683235 Ref: 2447683235 Ref: library/typing typing overload7683936 Ref: 2fb97683936 Ref: library/typing typing final7685204 Ref: 23e7685204 Ref: library/typing typing no_type_check7685884 Ref: 2fba7685884 Ref: library/typing typing no_type_check_decorator7686240 Ref: 2fbb7686240 Ref: library/typing typing type_check_only7686492 Ref: 2fbc7686492 Ref: library/typing typing runtime_checkable7687167 Ref: 2407687167 Ref: library/typing typing Any7687899 Ref: 6527687899 Ref: library/typing typing NoReturn7688089 Ref: 2fbd7688089 Ref: library/typing typing Union7688369 Ref: 2f7b7688369 Ref: library/typing typing Optional7689343 Ref: 2fbe7689343 Ref: library/typing typing Tuple7690033 Ref: 2f7c7690033 Ref: library/typing typing Callable7690671 Ref: 2f7d7690671 Ref: library/typing typing Literal7691435 Ref: 23c7691435 Ref: library/typing typing ClassVar7692301 Ref: 5a37692301 Ref: library/typing typing Final7693388 Ref: 23d7693388 Ref: library/typing typing AnyStr7693942 Ref: 2fbf7693942 Ref: library/typing typing TYPE_CHECKING7694506 Ref: 5a47694506 Ref: Classes functions and decorators-Footnote-17695248 Ref: Classes functions and decorators-Footnote-27695297 Ref: Classes functions and decorators-Footnote-37695346 Ref: Classes functions and decorators-Footnote-47695395 Ref: Classes functions and decorators-Footnote-57695444 Ref: Classes functions and decorators-Footnote-67695493 Ref: Classes functions and decorators-Footnote-77695542 Ref: Classes functions and decorators-Footnote-87695591 Ref: Classes functions and decorators-Footnote-97695640 Ref: Classes functions and decorators-Footnote-107695689 Ref: Classes functions and decorators-Footnote-117695739 Ref: Classes functions and decorators-Footnote-127695789 Node: pydoc — 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library/doctest simple-usage-checking-examples-in-a-text-file7707546 Ref: 2fc97707546 Node: How It Works7709892 Ref: library/doctest doctest-how-it-works7710057 Ref: 2fcb7710057 Ref: library/doctest how-it-works7710057 Ref: 2fcc7710057 Node: Which Docstrings Are Examined?7710712 Ref: library/doctest doctest-which-docstrings7710838 Ref: 2fcd7710838 Ref: library/doctest which-docstrings-are-examined7710838 Ref: 2fce7710838 Node: How are Docstring Examples Recognized?7711685 Ref: library/doctest doctest-finding-examples7711851 Ref: 2fcf7711851 Ref: library/doctest how-are-docstring-examples-recognized7711851 Ref: 2fd07711851 Node: What’s the Execution Context?7714939 Ref: library/doctest doctest-execution-context7715097 Ref: 2fd47715097 Ref: library/doctest what-s-the-execution-context7715097 Ref: 2fd57715097 Node: What About Exceptions?7715814 Ref: library/doctest doctest-exceptions7715946 Ref: 2fd67715946 Ref: library/doctest what-about-exceptions7715946 Ref: 2fd77715946 Ref: library/doctest option-flags-and-directives7720454 Ref: 2fd97720454 Ref: What About Exceptions?-Footnote-17720491 Node: Option Flags7720695 Ref: library/doctest doctest-options7720806 Ref: 83c7720806 Ref: library/doctest option-flags7720806 Ref: 2fda7720806 Ref: library/doctest doctest DONT_ACCEPT_TRUE_FOR_17721424 Ref: 2fdb7721424 Ref: library/doctest doctest DONT_ACCEPT_BLANKLINE7722052 Ref: 2fdc7722052 Ref: library/doctest doctest NORMALIZE_WHITESPACE7722505 Ref: 2fd17722505 Ref: library/doctest doctest ELLIPSIS7722995 Ref: dd17722995 Ref: library/doctest doctest IGNORE_EXCEPTION_DETAIL7723431 Ref: 2fd87723431 Ref: library/doctest doctest SKIP7725475 Ref: 2fdd7725475 Ref: library/doctest doctest COMPARISON_FLAGS7725989 Ref: 2fde7725989 Ref: library/doctest doctest REPORT_UDIFF7726161 Ref: dd27726161 Ref: library/doctest doctest REPORT_CDIFF7726317 Ref: dd37726317 Ref: library/doctest doctest REPORT_NDIFF7726477 Ref: dd47726477 Ref: library/doctest doctest REPORT_ONLY_FIRST_FAILURE7726941 Ref: 2fdf7726941 Ref: library/doctest doctest FAIL_FAST7727520 Ref: 83d7727520 Ref: library/doctest doctest REPORTING_FLAGS7727987 Ref: 2fe07727987 Ref: library/doctest doctest register_optionflag7728244 Ref: 2fe17728244 Node: Directives7728734 Ref: library/doctest directives7728834 Ref: 2fe47728834 Ref: library/doctest doctest-directives7728834 Ref: 2fd27728834 Ref: library/doctest grammar-token-directive7729059 Ref: 2fe57729059 Ref: library/doctest grammar-token-directive-options7729123 Ref: 2fe67729123 Ref: library/doctest grammar-token-directive-option7729196 Ref: 2fe77729196 Ref: library/doctest grammar-token-on-or-off7729259 Ref: 2fe87729259 Ref: library/doctest grammar-token-directive-option-name7729301 Ref: 2fe97729301 Node: Warnings<2>7731203 Ref: library/doctest doctest-warnings7731282 Ref: 2fea7731282 Ref: library/doctest warnings7731282 Ref: 2feb7731282 Node: Basic API7733171 Ref: library/doctest basic-api7733303 Ref: 2fec7733303 Ref: library/doctest doctest-basic-api7733303 Ref: 2fc77733303 Ref: library/doctest doctest testfile7733686 Ref: 2fca7733686 Ref: library/doctest doctest testmod7737618 Ref: dd07737618 Ref: library/doctest doctest run_docstring_examples7739364 Ref: 2fee7739364 Node: Unittest API7740342 Ref: library/doctest doctest-unittest-api7740474 Ref: 2fef7740474 Ref: library/doctest unittest-api7740474 Ref: 2ff07740474 Ref: library/doctest doctest DocFileSuite7741244 Ref: 2ff17741244 Ref: library/doctest doctest DocTestSuite7744968 Ref: 6cd7744968 Ref: library/doctest doctest set_unittest_reportflags7748118 Ref: 2ff37748118 Node: Advanced API7749314 Ref: library/doctest advanced-api7749446 Ref: 2ff47749446 Ref: library/doctest doctest-advanced-api7749446 Ref: 2ff57749446 Node: DocTest Objects7751587 Ref: library/doctest doctest-doctest7751675 Ref: 2ff77751675 Ref: library/doctest doctest-objects7751675 Ref: 2ff87751675 Ref: library/doctest doctest DocTest7751728 Ref: 2ff27751728 Ref: library/doctest doctest DocTest examples7752144 Ref: 2ff97752144 Ref: library/doctest doctest DocTest globs7752319 Ref: 2ffa7752319 Ref: library/doctest doctest DocTest name7752654 Ref: 2ffb7752654 Ref: library/doctest doctest DocTest filename7752847 Ref: 2ffc7752847 Ref: library/doctest doctest DocTest lineno7753084 Ref: 2ffd7753084 Ref: library/doctest doctest DocTest docstring7753362 Ref: 2ffe7753362 Node: Example Objects7753561 Ref: library/doctest doctest-example7753679 Ref: 2fff7753679 Ref: library/doctest example-objects7753679 Ref: 30007753679 Ref: library/doctest doctest Example7753732 Ref: 2ff67753732 Ref: library/doctest doctest Example source7754171 Ref: 30017754171 Ref: library/doctest doctest Example want7754415 Ref: 30027754415 Ref: library/doctest doctest Example exc_msg7754766 Ref: 30037754766 Ref: library/doctest doctest Example lineno7755251 Ref: 30057755251 Ref: library/doctest doctest Example indent7755482 Ref: 30067755482 Ref: library/doctest doctest Example options7755675 Ref: 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DocTestRunner7761271 Ref: 2fe37761271 Ref: library/doctest doctest DocTestRunner report_start7763379 Ref: 30127763379 Ref: library/doctest doctest DocTestRunner report_success7763878 Ref: 30137763878 Ref: library/doctest doctest DocTestRunner report_failure7764411 Ref: 30157764411 Ref: library/doctest doctest DocTestRunner report_unexpected_exception7764934 Ref: 30147764934 Ref: library/doctest doctest DocTestRunner run7765609 Ref: 30167765609 Ref: library/doctest doctest DocTestRunner summarize7766625 Ref: 30177766625 Node: OutputChecker objects7767050 Ref: library/doctest doctest-outputchecker7767150 Ref: 30187767150 Ref: library/doctest outputchecker-objects7767150 Ref: 30197767150 Ref: library/doctest doctest OutputChecker7767215 Ref: 2fe27767215 Ref: library/doctest doctest OutputChecker check_output7767711 Ref: 301a7767711 Ref: library/doctest doctest OutputChecker output_difference7768198 Ref: 301b7768198 Node: Debugging7768513 Ref: library/doctest debugging7768640 Ref: 301c7768640 Ref: library/doctest doctest-debugging7768640 Ref: 301d7768640 Ref: library/doctest doctest script_from_examples7770739 Ref: 30207770739 Ref: library/doctest doctest testsource7771726 Ref: 30217771726 Ref: library/doctest doctest debug7772523 Ref: 301f7772523 Ref: library/doctest doctest debug_src7773613 Ref: 30237773613 Ref: library/doctest doctest DebugRunner7774487 Ref: 301e7774487 Ref: library/doctest doctest DocTestFailure7775264 Ref: 30257775264 Ref: library/doctest doctest DocTestFailure test7775627 Ref: 30267775627 Ref: library/doctest doctest DocTestFailure example7775750 Ref: 30277775750 Ref: library/doctest doctest DocTestFailure got7775833 Ref: 30287775833 Ref: library/doctest doctest UnexpectedException7775905 Ref: 30247775905 Ref: library/doctest doctest UnexpectedException test7776258 Ref: 30297776258 Ref: library/doctest doctest UnexpectedException example7776386 Ref: 302a7776386 Ref: library/doctest doctest UnexpectedException exc_info7776474 Ref: 302b7776474 Node: Soapbox7776635 Ref: library/doctest doctest-soapbox7776741 Ref: 302c7776741 Ref: library/doctest soapbox7776741 Ref: 302d7776741 Node: unittest — Unit testing framework7780585 Ref: library/unittest doc7780773 Ref: 302e7780773 Ref: library/unittest module-unittest7780773 Ref: 11b7780773 Ref: library/unittest unittest-unit-testing-framework7780773 Ref: 302f7780773 Ref: unittest — Unit testing framework-Footnote-17783930 Ref: unittest — Unit testing framework-Footnote-27784007 Ref: unittest — Unit testing framework-Footnote-37784100 Ref: unittest — Unit testing framework-Footnote-47784133 Ref: unittest — Unit testing framework-Footnote-57784197 Ref: unittest — Unit testing framework-Footnote-67784255 Ref: unittest — Unit testing framework-Footnote-77784285 Ref: unittest — Unit testing framework-Footnote-87784313 Ref: unittest — Unit testing framework-Footnote-97784343 Node: Basic example7784377 Ref: library/unittest basic-example7784496 Ref: 30317784496 Ref: library/unittest unittest-minimal-example7784496 Ref: 30327784496 Node: Command-Line Interface<3>7787300 Ref: library/unittest command-line-interface7787442 Ref: 30347787442 Ref: library/unittest unittest-command-line-interface7787442 Ref: 30357787442 Node: Command-line options<3>7788838 Ref: library/unittest command-line-options7788923 Ref: 30377788923 Ref: library/unittest cmdoption-unittest-b7789037 Ref: cc37789037 Ref: library/unittest cmdoption-unittest-c7789304 Ref: cc47789304 Ref: library/unittest cmdoption-unittest-f7789644 Ref: cc67789644 Ref: library/unittest cmdoption-unittest-k7789735 Ref: 30397789735 Ref: library/unittest cmdoption-unittest-locals7790451 Ref: 303a7790451 Node: Test Discovery7790844 Ref: library/unittest test-discovery7790993 Ref: 303b7790993 Ref: library/unittest unittest-test-discovery7790993 Ref: 30367790993 Ref: library/unittest cmdoption-unittest-discover-v7791888 Ref: 303c7791888 Ref: library/unittest cmdoption-unittest-discover-s7791944 Ref: 303d7791944 Ref: library/unittest cmdoption-unittest-discover-p7792050 Ref: 303e7792050 Ref: library/unittest cmdoption-unittest-discover-t7792152 Ref: 303f7792152 Node: Organizing test code7793925 Ref: library/unittest organizing-test-code7794071 Ref: 30417794071 Ref: library/unittest organizing-tests7794071 Ref: 30337794071 Node: Re-using old test code7798825 Ref: library/unittest legacy-unit-tests7798993 Ref: 30437798993 Ref: library/unittest re-using-old-test-code7798993 Ref: 30447798993 Node: Skipping tests and expected failures7800533 Ref: library/unittest skipping-tests-and-expected-failures7800726 Ref: 30457800726 Ref: library/unittest unittest-skipping7800726 Ref: 30467800726 Ref: library/unittest unittest skip7803814 Ref: 30477803814 Ref: library/unittest unittest skipIf7803962 Ref: 304a7803962 Ref: library/unittest unittest skipUnless7804068 Ref: 304b7804068 Ref: library/unittest unittest expectedFailure7804182 Ref: 30497804182 Ref: library/unittest unittest SkipTest7804402 Ref: 9037804402 Node: Distinguishing test iterations using subtests7804890 Ref: library/unittest distinguishing-test-iterations-using-subtests7805082 Ref: 304c7805082 Ref: library/unittest subtests7805082 Ref: 9017805082 Node: Classes and functions7807376 Ref: library/unittest classes-and-functions7807557 Ref: 304d7807557 Ref: library/unittest unittest-contents7807557 Ref: 304e7807557 Node: Test cases7807759 Ref: library/unittest test-cases7807850 Ref: 304f7807850 Ref: library/unittest testcase-objects7807850 Ref: 30507807850 Ref: library/unittest unittest TestCase7807893 Ref: 8ff7807893 Ref: library/unittest unittest TestCase setUp7809215 Ref: ccb7809215 Ref: library/unittest unittest TestCase tearDown7809593 Ref: ccc7809593 Ref: library/unittest unittest TestCase setUpClass7810367 Ref: 24c7810367 Ref: library/unittest unittest TestCase tearDownClass7810806 Ref: cc97810806 Ref: library/unittest unittest TestCase run7811254 Ref: abe7811254 Ref: library/unittest unittest TestCase 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library/unittest unittest TestCase assertIsInstance7818986 Ref: cd17818986 Ref: library/unittest unittest TestCase assertNotIsInstance7819041 Ref: cd27819041 Ref: library/unittest unittest TestCase assertRaises7821714 Ref: aba7821714 Ref: library/unittest unittest TestCase assertRaisesRegex7823441 Ref: abb7823441 Ref: library/unittest unittest TestCase assertWarns7824438 Ref: library/unittest unittest TestCase assertWarnsRegex7826149 Ref: abd7826149 Ref: library/unittest unittest TestCase assertLogs7827084 Ref: 9057827084 Ref: library/unittest unittest TestCase records7828137 Ref: 30557828137 Ref: library/unittest unittest TestCase output7828280 Ref: 30567828280 Ref: library/unittest unittest TestCase assertAlmostEqual7831605 Ref: bb77831605 Ref: library/unittest unittest TestCase assertNotAlmostEqual7831703 Ref: bb87831703 Ref: library/unittest unittest TestCase assertGreater7832774 Ref: cd37832774 Ref: library/unittest unittest TestCase assertGreaterEqual7832831 Ref: cd47832831 Ref: library/unittest unittest TestCase assertLess7832893 Ref: cd57832893 Ref: library/unittest unittest TestCase assertLessEqual7832947 Ref: cd67832947 Ref: library/unittest unittest TestCase assertRegex7833312 Ref: bb17833312 Ref: library/unittest unittest TestCase assertNotRegex7833365 Ref: 30577833365 Ref: library/unittest unittest TestCase assertCountEqual7834238 Ref: baf7834238 Ref: library/unittest type-specific-methods7834899 Ref: 30547834899 Ref: library/unittest unittest TestCase addTypeEqualityFunc7835217 Ref: ce17835217 Ref: library/unittest unittest TestCase assertMultiLineEqual7837961 Ref: cd77837961 Ref: library/unittest unittest TestCase assertSequenceEqual7838376 Ref: cdd7838376 Ref: library/unittest unittest TestCase assertListEqual7839001 Ref: cdb7839001 Ref: library/unittest unittest TestCase assertTupleEqual7839060 Ref: cdc7839060 Ref: library/unittest unittest TestCase assertSetEqual7839508 Ref: cda7839508 Ref: library/unittest unittest TestCase assertDictEqual7839960 Ref: cde7839960 Ref: library/unittest other-methods-and-attrs7840318 Ref: 30597840318 Ref: library/unittest unittest TestCase fail7840409 Ref: 305a7840409 Ref: library/unittest unittest TestCase failureException7840552 Ref: 30587840552 Ref: library/unittest unittest TestCase longMessage7840968 Ref: cc87840968 Ref: library/unittest unittest TestCase maxDiff7841706 Ref: bb07841706 Ref: library/unittest unittest TestCase countTestCases7842387 Ref: 305b7842387 Ref: library/unittest unittest TestCase defaultTestResult7842569 Ref: 30527842569 Ref: library/unittest unittest TestCase id7842999 Ref: 305c7842999 Ref: library/unittest unittest TestCase shortDescription7843194 Ref: 305d7843194 Ref: library/unittest unittest TestCase addCleanup7843814 Ref: 2a27843814 Ref: library/unittest unittest TestCase doCleanups7844414 Ref: cca7844414 Ref: library/unittest unittest TestCase addClassCleanup7845052 Ref: 24b7845052 Ref: library/unittest unittest TestCase doClassCleanups7845724 Ref: 305f7845724 Ref: library/unittest unittest IsolatedAsyncioTestCase7846426 Ref: 24d7846426 Ref: library/unittest unittest IsolatedAsyncioTestCase asyncSetUp7846637 Ref: 30607846637 Ref: library/unittest unittest IsolatedAsyncioTestCase asyncTearDown7847077 Ref: 30617847077 Ref: library/unittest unittest IsolatedAsyncioTestCase addAsyncCleanup7847923 Ref: 30627847923 Ref: library/unittest unittest IsolatedAsyncioTestCase run7848081 Ref: 30637848081 Ref: library/unittest unittest FunctionTestCase7849818 Ref: 30427849818 Node: Deprecated aliases7850329 Ref: library/unittest deprecated-aliases7850394 Ref: bb97850394 Ref: library/unittest id17850394 Ref: 30647850394 Node: Grouping tests7853523 Ref: library/unittest grouping-tests7853648 Ref: 30657853648 Ref: library/unittest testsuite-objects7853648 Ref: 30667853648 Ref: library/unittest unittest TestSuite7853699 Ref: 6ce7853699 Ref: library/unittest unittest TestSuite addTest7854646 Ref: 30677854646 Ref: library/unittest unittest TestSuite addTests7854766 Ref: 30687854766 Ref: library/unittest unittest TestSuite run7855142 Ref: 30697855142 Ref: library/unittest unittest TestSuite debug7855444 Ref: 306a7855444 Ref: library/unittest unittest TestSuite countTestCases7855717 Ref: 306b7855717 Ref: library/unittest unittest TestSuite __iter__7855881 Ref: 9627855881 Node: Loading and running tests7857337 Ref: library/unittest loading-and-running-tests7857443 Ref: 306c7857443 Ref: library/unittest unittest TestLoader7857516 Ref: 7827857516 Ref: library/unittest unittest TestLoader errors7858010 Ref: 7817858010 Ref: library/unittest unittest TestLoader loadTestsFromTestCase7858479 Ref: 306e7858479 Ref: library/unittest unittest TestLoader loadTestsFromModule7859030 Ref: 7807859030 Ref: library/unittest unittest TestLoader loadTestsFromName7860535 Ref: cdf7860535 Ref: library/unittest unittest TestLoader loadTestsFromNames7862335 Ref: 30707862335 Ref: library/unittest unittest TestLoader getTestCaseNames7862620 Ref: 306f7862620 Ref: library/unittest unittest TestLoader discover7862823 Ref: 9047862823 Ref: library/unittest unittest TestLoader testMethodPrefix7865689 Ref: 30717865689 Ref: library/unittest unittest TestLoader sortTestMethodsUsing7865978 Ref: 30727865978 Ref: library/unittest unittest TestLoader suiteClass7866192 Ref: ce07866192 Ref: library/unittest unittest TestLoader testNamePatterns7866489 Ref: 30737866489 Ref: library/unittest unittest TestResult7867203 Ref: abf7867203 Ref: library/unittest unittest TestResult errors7868065 Ref: 30747868065 Ref: library/unittest unittest TestResult failures7868295 Ref: 30757868295 Ref: library/unittest unittest TestResult skipped7868584 Ref: 30767868584 Ref: library/unittest unittest TestResult expectedFailures7868780 Ref: 30777868780 Ref: library/unittest unittest TestResult unexpectedSuccesses7869022 Ref: 30787869022 Ref: library/unittest unittest TestResult shouldStop7869187 Ref: 30797869187 Ref: library/unittest unittest TestResult testsRun7869321 Ref: 307b7869321 Ref: library/unittest unittest TestResult buffer7869400 Ref: 307c7869400 Ref: library/unittest unittest TestResult failfast7869849 Ref: 307f7869849 Ref: library/unittest unittest TestResult tb_locals7870034 Ref: 30807870034 Ref: library/unittest unittest TestResult wasSuccessful7870182 Ref: 30817870182 Ref: library/unittest unittest TestResult stop7870519 Ref: 307a7870519 Ref: library/unittest unittest TestResult startTest7871478 Ref: 307d7871478 Ref: library/unittest unittest TestResult stopTest7871577 Ref: 307e7871577 Ref: library/unittest unittest TestResult startTestRun7871712 Ref: ce37871712 Ref: library/unittest unittest TestResult stopTestRun7871831 Ref: ce47871831 Ref: library/unittest unittest TestResult addError7871948 Ref: 30837871948 Ref: library/unittest unittest TestResult addFailure7872415 Ref: 30847872415 Ref: library/unittest unittest TestResult addSuccess7872873 Ref: 30857872873 Ref: library/unittest unittest TestResult addSkip7873015 Ref: 30867873015 Ref: library/unittest unittest TestResult addExpectedFailure7873311 Ref: 30877873311 Ref: library/unittest unittest TestResult addUnexpectedSuccess7873737 Ref: 30887873737 Ref: library/unittest unittest TestResult addSubTest7874043 Ref: 30897874043 Ref: library/unittest unittest TextTestResult7874715 Ref: 305e7874715 Ref: library/unittest unittest defaultTestLoader7875037 Ref: 306d7875037 Ref: library/unittest unittest TextTestRunner7875292 Ref: 30827875292 Ref: library/unittest unittest TextTestRunner _makeResult7876888 Ref: 308b7876888 Ref: library/unittest unittest TextTestRunner run7877540 Ref: 308c7877540 Ref: library/unittest unittest main7877901 Ref: 9027877901 Node: load_tests Protocol7880769 Ref: library/unittest load-tests-protocol7880850 Ref: 30407880850 Node: Class and Module Fixtures7883522 Ref: library/unittest class-and-module-fixtures7883673 Ref: 30517883673 Node: setUpClass and tearDownClass7885561 Ref: library/unittest setupclass-and-teardownclass7885690 Ref: 308d7885690 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unittest mock Mock mock_add_spec7908117 Ref: 30a77908117 Ref: library/unittest mock unittest mock Mock attach_mock7908442 Ref: 30a87908442 Ref: library/unittest mock unittest mock Mock configure_mock7908735 Ref: 30a17908735 Ref: library/unittest mock unittest mock Mock __dir__7909969 Ref: 30aa7909969 Ref: library/unittest mock unittest mock Mock _get_child_mock7910302 Ref: 30ac7910302 Ref: library/unittest mock unittest mock Mock called7910702 Ref: 30ad7910702 Ref: library/unittest mock unittest mock Mock call_count7911002 Ref: 30ae7911002 Ref: library/unittest mock unittest mock Mock return_value7911333 Ref: 30a07911333 Ref: library/unittest mock unittest mock Mock side_effect7912139 Ref: 309e7912139 Ref: library/unittest mock unittest mock Mock call_args7914609 Ref: 30af7914609 Ref: library/unittest mock unittest mock Mock call_args_list7916436 Ref: 30b07916436 Ref: library/unittest mock unittest mock Mock method_calls7917479 Ref: 30a97917479 Ref: library/unittest mock unittest mock Mock mock_calls7918217 Ref: 30a67918217 Ref: library/unittest mock unittest mock Mock __class__7919755 Ref: 30b37919755 Ref: library/unittest mock unittest mock NonCallableMock7920528 Ref: 309c7920528 Ref: library/unittest mock unittest mock PropertyMock7923056 Ref: 30b47923056 Ref: library/unittest mock unittest mock AsyncMock7924430 Ref: 2487924430 Ref: library/unittest mock unittest mock AsyncMock assert_awaited7927286 Ref: 30b57927286 Ref: library/unittest mock unittest mock AsyncMock assert_awaited_once7928021 Ref: 30b67928021 Ref: library/unittest mock unittest mock AsyncMock assert_awaited_with7928586 Ref: 30b77928586 Ref: library/unittest mock unittest mock AsyncMock assert_awaited_once_with7929255 Ref: 30b87929255 Ref: library/unittest mock unittest mock AsyncMock assert_any_await7929980 Ref: 30b97929980 Ref: library/unittest mock unittest mock AsyncMock assert_has_awaits7930623 Ref: 30ba7930623 Ref: library/unittest mock unittest mock AsyncMock assert_not_awaited7931718 Ref: 30bc7931718 Ref: library/unittest mock unittest mock AsyncMock reset_mock7931893 Ref: 30bd7931893 Ref: library/unittest mock unittest mock AsyncMock await_count7932124 Ref: 30be7932124 Ref: library/unittest mock unittest mock AsyncMock await_args7932570 Ref: 30bf7932570 Ref: library/unittest mock unittest mock AsyncMock await_args_list7933189 Ref: 30bb7933189 Ref: The Mock Class-Footnote-17934055 Node: Calling7934481 Ref: library/unittest mock calling7934567 Ref: 30c07934567 Node: Deleting Attributes7937809 Ref: library/unittest mock deleting-attributes7937937 Ref: 30c17937937 Ref: library/unittest mock id27937937 Ref: 30c27937937 Node: Mock names and the name attribute7938714 Ref: library/unittest mock mock-names-and-the-name-attribute7938864 Ref: 30c37938864 Node: Attaching Mocks as Attributes7939454 Ref: library/unittest mock attaching-mocks-as-attributes7939576 Ref: 30c47939576 Node: The patchers7941440 Ref: library/unittest mock the-patchers7941592 Ref: 30c57941592 Node: patch7942207 Ref: library/unittest mock patch7942282 Ref: 30c67942282 Ref: library/unittest mock unittest mock patch7942482 Ref: 7887942482 Node: patch object7951324 Ref: library/unittest mock patch-object7951418 Ref: 30c87951418 Ref: library/unittest mock unittest mock patch object7951463 Ref: 30c97951463 Node: patch dict7952942 Ref: library/unittest mock patch-dict7953045 Ref: 30ca7953045 Ref: library/unittest mock unittest mock patch dict7953088 Ref: 30977953088 Node: patch multiple7957208 Ref: library/unittest mock patch-multiple7957327 Ref: 30cc7957327 Ref: library/unittest mock unittest mock patch multiple7957378 Ref: 30cd7957378 Node: patch methods start and stop7960086 Ref: library/unittest mock patch-methods-start-and-stop7960209 Ref: 30ce7960209 Ref: library/unittest mock start-and-stop7960209 Ref: 30cf7960209 Ref: library/unittest mock unittest mock patch stopall7962946 Ref: 30d07962946 Node: patch builtins7963055 Ref: library/unittest mock id47963175 Ref: 30d17963175 Ref: library/unittest mock patch-builtins7963175 Ref: 30d27963175 Node: TEST_PREFIX7963496 Ref: library/unittest mock id57963612 Ref: 30d37963612 Ref: library/unittest mock test-prefix7963612 Ref: 30cb7963612 Node: Nesting Patch Decorators7964495 Ref: library/unittest mock nesting-patch-decorators7964611 Ref: 30d47964611 Node: Where to patch7965528 Ref: library/unittest mock id67965671 Ref: 30c77965671 Ref: library/unittest mock where-to-patch7965671 Ref: 30967965671 Node: Patching Descriptors and Proxy Objects7967437 Ref: library/unittest mock patching-descriptors-and-proxy-objects7967547 Ref: 30d57967547 Ref: Patching Descriptors and Proxy Objects-Footnote-17967988 Node: MagicMock and magic method support7968070 Ref: library/unittest mock magicmock-and-magic-method-support7968215 Ref: 30d67968215 Node: Mocking Magic Methods7968357 Ref: library/unittest mock magic-methods7968468 Ref: 30987968468 Ref: library/unittest mock mocking-magic-methods7968468 Ref: 30d77968468 Ref: Mocking Magic 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library/unittest mock-examples further-examples8020074 Ref: 30f68020074 Ref: library/unittest mock-examples id18020074 Ref: 30f78020074 Node: Mocking chained calls8020702 Ref: library/unittest mock-examples mocking-chained-calls8020800 Ref: 30f88020800 Node: Partial mocking8023915 Ref: library/unittest mock-examples partial-mocking8024048 Ref: 30f98024048 Ref: Partial mocking-Footnote-18026056 Node: Mocking a Generator Method8026157 Ref: library/unittest mock-examples mocking-a-generator-method8026313 Ref: 30fa8026313 Ref: Mocking a Generator Method-Footnote-18027447 Node: Applying the same patch to every test method8027771 Ref: library/unittest mock-examples applying-the-same-patch-to-every-test-method8027935 Ref: 30fb8027935 Node: Mocking Unbound Methods8030253 Ref: library/unittest mock-examples mocking-unbound-methods8030424 Ref: 30fc8030424 Node: Checking multiple calls with mock8032192 Ref: library/unittest mock-examples checking-multiple-calls-with-mock8032348 Ref: 30fd8032348 Node: Coping with mutable arguments8033892 Ref: library/unittest mock-examples coping-with-mutable-arguments8034040 Ref: 30fe8034040 Node: Nesting Patches8038215 Ref: library/unittest mock-examples nesting-patches8038365 Ref: 30ff8038365 Node: Mocking a dictionary with MagicMock8040172 Ref: library/unittest mock-examples mocking-a-dictionary-with-magicmock8040329 Ref: 31008040329 Node: Mock subclasses and their attributes8042975 Ref: library/unittest mock-examples mock-subclasses-and-their-attributes8043148 Ref: 31018043148 Ref: Mock subclasses and their attributes-Footnote-18045284 Ref: Mock subclasses and their attributes-Footnote-28045457 Ref: Mock subclasses and their attributes-Footnote-38045515 Node: Mocking imports with patch dict8045602 Ref: library/unittest mock-examples mocking-imports-with-patch-dict8045796 Ref: 31028045796 Node: Tracking order of calls and less verbose call assertions8048444 Ref: library/unittest mock-examples 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310d8063380 Ref: library/2to3 2to3fixer-buffer8063458 Ref: 310e8063458 Ref: library/2to3 2to3fixer-dict8063669 Ref: 310f8063669 Ref: library/2to3 2to3fixer-except8064281 Ref: 31108064281 Ref: library/2to3 2to3fixer-exec8064361 Ref: 31118064361 Ref: library/2to3 2to3fixer-execfile8064458 Ref: 31128064458 Ref: library/2to3 2to3fixer-exitfunc8064655 Ref: 31138064655 Ref: library/2to3 2to3fixer-filter8064771 Ref: 31148064771 Ref: library/2to3 2to3fixer-funcattrs8064861 Ref: 31158064861 Ref: library/2to3 2to3fixer-future8065045 Ref: 31168065045 Ref: library/2to3 2to3fixer-getcwdu8065135 Ref: 31178065135 Ref: library/2to3 2to3fixer-has_key8065220 Ref: 31188065220 Ref: library/2to3 2to3fixer-idioms8065304 Ref: 31198065304 Ref: library/2to3 2to3fixer-import8065838 Ref: 311a8065838 Ref: library/2to3 2to3fixer-imports8065930 Ref: 311b8065930 Ref: library/2to3 2to3fixer-imports28066008 Ref: 311c8066008 Ref: library/2to3 2to3fixer-input8066195 Ref: 311d8066195 Ref: library/2to3 2to3fixer-intern8066282 Ref: 311e8066282 Ref: library/2to3 2to3fixer-isinstance8066363 Ref: 311f8066363 Ref: library/2to3 2to3fixer-itertools_imports8066665 Ref: 31208066665 Ref: library/2to3 2to3fixer-itertools8066913 Ref: 31218066913 Ref: library/2to3 2to3fixer-long8067168 Ref: 31228067168 Ref: library/2to3 2to3fixer-map8067233 Ref: 31238067233 Ref: library/2to3 2to3fixer-metaclass8067441 Ref: 31248067441 Ref: library/2to3 2to3fixer-methodattrs8067603 Ref: 31258067603 Ref: library/2to3 2to3fixer-ne8067746 Ref: 31268067746 Ref: library/2to3 2to3fixer-next8067829 Ref: 31278067829 Ref: library/2to3 2to3fixer-nonzero8068026 Ref: 31288068026 Ref: library/2to3 2to3fixer-numliterals8068110 Ref: 31298068110 Ref: library/2to3 2to3fixer-operator8068189 Ref: 312a8068189 Ref: library/2to3 2to3fixer-paren8069872 Ref: 312b8069872 Ref: library/2to3 2to3fixer-print8070053 Ref: 312c8070053 Ref: library/2to3 2to3fixer-raise8070153 Ref: 312d8070153 Ref: library/2to3 2to3fixer-raw_input8070432 Ref: 312e8070432 Ref: library/2to3 2to3fixer-reduce8070514 Ref: 312f8070514 Ref: library/2to3 2to3fixer-reload8070612 Ref: 31308070612 Ref: library/2to3 2to3fixer-renames8070699 Ref: 31318070699 Ref: library/2to3 2to3fixer-repr8070781 Ref: 31328070781 Ref: library/2to3 2to3fixer-set_literal8070869 Ref: 31338070869 Ref: library/2to3 2to3fixer-standarderror8070999 Ref: 31348070999 Ref: library/2to3 2to3fixer-sys_exc8071088 Ref: 31358071088 Ref: library/2to3 2to3fixer-throw8071245 Ref: 31368071245 Ref: library/2to3 2to3fixer-tuple_params8071333 Ref: 31378071333 Ref: library/2to3 2to3fixer-types8071458 Ref: 31388071458 Ref: library/2to3 2to3fixer-unicode8071575 Ref: 31398071575 Ref: library/2to3 2to3fixer-urllib8071646 Ref: 313a8071646 Ref: library/2to3 2to3fixer-ws_comma8071774 Ref: 313b8071774 Ref: library/2to3 2to3fixer-xrange8071889 Ref: 313c8071889 Ref: library/2to3 2to3fixer-xreadlines8072036 Ref: 313d8072036 Ref: library/2to3 2to3fixer-zip8072134 Ref: 313e8072134 Node: lib2to3 - 2to3’s 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library/test test support LARGEST8085921 Ref: 31648085921 Ref: library/test test support SMALLEST8086055 Ref: 31658086055 Ref: library/test test support forget8086257 Ref: 31668086257 Ref: library/test test support unload8086428 Ref: 31678086428 Ref: library/test test support unlink8086514 Ref: 31688086514 Ref: library/test test support rmdir8086719 Ref: 31698086719 Ref: library/test test support rmtree8086922 Ref: 316a8086922 Ref: library/test test support make_legacy_pyc8087221 Ref: 316b8087221 Ref: library/test test support is_resource_enabled8087556 Ref: 316c8087556 Ref: library/test test support python_is_optimized8087783 Ref: 316d8087783 Ref: library/test test support with_pymalloc8087911 Ref: 316e8087911 Ref: library/test test support requires8088000 Ref: 31488088000 Ref: library/test test support system_must_validate_cert8088367 Ref: 316f8088367 Ref: library/test test support sortdict8088514 Ref: 31708088514 Ref: library/test test support findfile8088606 Ref: 31718088606 Ref: library/test test support create_empty_file8088978 Ref: 31728088978 Ref: library/test test support fd_count8089120 Ref: 31738089120 Ref: library/test test support match_test8089209 Ref: 31748089209 Ref: library/test test support set_match_tests8089324 Ref: 31758089324 Ref: library/test test support run_unittest8089439 Ref: 31768089439 Ref: library/test test support run_doctest8090101 Ref: 31778090101 Ref: library/test test support setswitchinterval8090568 Ref: 31788090568 Ref: library/test test support check_impl_detail8090794 Ref: 31798090794 Ref: library/test test support check_warnings8091206 Ref: 317a8091206 Ref: library/test test support check_no_resource_warning8094252 Ref: 317d8094252 Ref: library/test test support set_memlimit8094516 Ref: 315e8094516 Ref: library/test test support record_original_stdout8094674 Ref: 317e8094674 Ref: library/test test support get_original_stdout8094840 Ref: 317f8094840 Ref: library/test test support strip_python_strerr8095013 Ref: 31808095013 Ref: library/test test support args_from_interpreter_flags8095270 Ref: 31818095270 Ref: library/test test support optim_args_from_interpreter_flags8095459 Ref: 31828095459 Ref: library/test test support captured_stdin8095641 Ref: 31838095641 Ref: library/test test support captured_stdout8095686 Ref: 31848095686 Ref: library/test test support captured_stderr8095732 Ref: 31858095732 Ref: library/test test support temp_dir8096457 Ref: 31868096457 Ref: library/test test support change_cwd8096900 Ref: 31878096900 Ref: library/test test support temp_cwd8097259 Ref: 31888097259 Ref: library/test test support temp_umask8097897 Ref: 31898097897 Ref: library/test test support transient_internet8098009 Ref: 318a8098009 Ref: library/test test support disable_faulthandler8098268 Ref: 318b8098268 Ref: library/test test support gc_collect8098402 Ref: 318c8098402 Ref: library/test test support disable_gc8098738 Ref: 318d8098738 Ref: library/test test support swap_attr8098884 Ref: 318e8098884 Ref: library/test test support swap_item8099470 Ref: 318f8099470 Ref: library/test test support wait_threads_exit8100054 Ref: 31908100054 Ref: library/test test support start_threads8100210 Ref: 31918100210 Ref: library/test test support calcobjsize8100366 Ref: 31928100366 Ref: library/test test support calcvobjsize8100538 Ref: 31938100538 Ref: library/test test support checksizeof8100713 Ref: 31948100713 Ref: library/test test support can_symlink8100884 Ref: 31958100884 Ref: library/test test support can_xattr8101009 Ref: 31968101009 Ref: library/test test support skip_unless_symlink8101123 Ref: 31978101123 Ref: library/test test support skip_unless_xattr8101254 Ref: 31988101254 Ref: library/test test support skip_unless_bind_unix_socket8101369 Ref: 31998101369 Ref: library/test test support anticipate_failure8101519 Ref: 319a8101519 Ref: library/test test support run_with_locale8101781 Ref: 319b8101781 Ref: library/test test support run_with_tz8102141 Ref: 319c8102141 Ref: library/test test support requires_freebsd_version8102303 Ref: 319d8102303 Ref: library/test test support requires_linux_version8102537 Ref: 319e8102537 Ref: library/test test support requires_mac_version8102766 Ref: 319f8102766 Ref: library/test test support requires_IEEE_7548102998 Ref: 31a08102998 Ref: library/test test support requires_zlib8103107 Ref: 31a18103107 Ref: library/test test support requires_gzip8103222 Ref: 31a28103222 Ref: library/test test support requires_bz28103336 Ref: 31a38103336 Ref: library/test test support requires_lzma8103448 Ref: 31a48103448 Ref: library/test test support requires_resource8103562 Ref: 31a58103562 Ref: library/test test support requires_docstrings8103687 Ref: 31a68103687 Ref: library/test test support cpython_only8103810 Ref: 31a78103810 Ref: library/test test support impl_detail8103913 Ref: 31a88103913 Ref: library/test test support no_tracing8104143 Ref: 31a98104143 Ref: library/test test support refcount_test8104273 Ref: 31aa8104273 Ref: library/test test support reap_threads8104584 Ref: 31ab8104584 Ref: library/test test support bigmemtest8104715 Ref: 31ac8104715 Ref: library/test test support bigaddrspacetest8105462 Ref: 31ad8105462 Ref: library/test test support make_bad_fd8105602 Ref: 31ae8105602 Ref: library/test test support check_syntax_error8105761 Ref: 31af8105761 Ref: library/test test support check_syntax_warning8106315 Ref: 31b08106315 Ref: library/test test support open_urlresource8107116 Ref: 31b18107116 Ref: library/test test support import_module8107245 Ref: 31b28107245 Ref: library/test test support import_fresh_module8107849 Ref: 31b38107849 Ref: library/test test support modules_setup8109450 Ref: 31b48109450 Ref: library/test test support modules_cleanup8109543 Ref: 31b58109543 Ref: library/test test support threading_setup8109707 Ref: 31b68109707 Ref: library/test test support threading_cleanup8109818 Ref: 31b78109818 Ref: library/test test support join_thread8110029 Ref: 31b88110029 Ref: library/test test support reap_children8110225 Ref: 31b98110225 Ref: library/test test support get_attribute8110499 Ref: 31ba8110499 Ref: library/test test support bind_port8110661 Ref: 31bb8110661 Ref: library/test test support bind_unix_socket8111591 Ref: 31bc8111591 Ref: library/test test support catch_threading_exception8111760 Ref: 31bd8111760 Ref: library/test test support catch_unraisable_exception8112694 Ref: 31be8112694 Ref: library/test test support find_unused_port8113580 Ref: 31bf8113580 Ref: library/test test support load_package_tests8114888 Ref: 31c08114888 Ref: library/test test support fs_is_case_insensitive8115518 Ref: 31c18115518 Ref: library/test test support detect_api_mismatch8115666 Ref: 31c28115666 Ref: library/test test support patch8116135 Ref: 31c38116135 Ref: library/test test support run_in_subinterp8116471 Ref: 31c48116471 Ref: library/test test support check_free_after_iterating8116640 Ref: 31c58116640 Ref: library/test test support missing_compiler_executable8116789 Ref: 31c68116789 Ref: library/test test support check__all__8117111 Ref: 31c78117111 Ref: library/test test support TransientResource8118975 Ref: 31c88118975 Ref: library/test test support EnvironmentVarGuard8119431 Ref: 31c98119431 Ref: library/test test support EnvironmentVarGuard set8119889 Ref: 31ca8119889 Ref: library/test test support EnvironmentVarGuard unset8120036 Ref: 31cb8120036 Ref: library/test test support SuppressCrashReport8120147 Ref: 31cc8120147 Ref: library/test test support CleanImport8120649 Ref: 31cf8120649 Ref: library/test test support DirsOnSysPath8121008 Ref: 31d08121008 Ref: library/test test support SaveSignals8121499 Ref: 31d18121499 Ref: library/test test support Matcher8121630 Ref: 31d28121630 Ref: library/test test support Matcher matches8121663 Ref: 31d38121663 Ref: library/test test support Matcher match_value8121776 Ref: 31d48121776 Ref: library/test test support WarningsRecorder8121915 Ref: 31d58121915 Ref: library/test test support BasicTestRunner8122090 Ref: 31d68122090 Ref: library/test test support BasicTestRunner run8122131 Ref: 31d78122131 Ref: library/test test support TestHandler8122205 Ref: 31d88122205 Ref: library/test test support FakePath8122311 Ref: 31d98122311 Ref: test support — Utilities for the Python test suite-Footnote-18122594 Ref: test support — Utilities for the Python test suite-Footnote-28122643 Ref: test support — Utilities for the Python test suite-Footnote-38122692 Node: test support script_helper — Utilities for the Python execution tests8122772 Ref: library/test module-test support script_helper8122958 Ref: 1078122958 Ref: library/test test-support-script-helper-utilities-for-the-python-execution-tests8122958 Ref: 31da8122958 Ref: library/test test support script_helper interpreter_requires_environment8123232 Ref: 31db8123232 Ref: library/test test support script_helper run_python_until_end8124207 Ref: 31dc8124207 Ref: library/test test support script_helper assert_python_ok8124493 Ref: 31dd8124493 Ref: library/test test support script_helper assert_python_failure8125007 Ref: 31de8125007 Ref: library/test test support script_helper spawn_python8125349 Ref: 31df8125349 Ref: library/test test support script_helper kill_python8125662 Ref: 31e08125662 Ref: library/test test support script_helper make_script8125818 Ref: 31e18125818 Ref: library/test test support script_helper make_zip_script8126127 Ref: 31e28126127 Ref: library/test test support script_helper make_pkg8126496 Ref: 31e38126496 Ref: library/test test support script_helper make_zip_pkg8126699 Ref: 31e48126699 Node: Debugging and Profiling8127356 Ref: library/debug doc8127513 Ref: 31e58127513 Ref: library/debug debugging-and-profiling8127513 Ref: 31e68127513 Ref: library/audit_events audit-events8127971 Ref: 31e78127971 Node: Audit events table8128303 Ref: library/audit_events doc8128416 Ref: 31e88128416 Ref: library/audit_events audit-events-table8128416 Ref: 31e98128416 Node: bdb — Debugger framework8181513 Ref: library/bdb doc8181677 Ref: 32128181677 Ref: library/bdb bdb-debugger-framework8181677 Ref: 32138181677 Ref: library/bdb module-bdb8181677 Ref: f8181677 Ref: library/bdb bdb BdbQuit8182012 Ref: 32148182012 Ref: library/bdb bdb Breakpoint8182176 Ref: 32158182176 Ref: library/bdb bdb Breakpoint deleteMe8183044 Ref: 32168183044 Ref: library/bdb bdb Breakpoint enable8183260 Ref: 32178183260 Ref: library/bdb bdb Breakpoint disable8183331 Ref: 32188183331 Ref: library/bdb bdb Breakpoint bpformat8183404 Ref: 32198183404 Ref: library/bdb bdb Breakpoint bpprint8183838 Ref: 321a8183838 Ref: library/bdb bdb Bdb8184003 Ref: c988184003 Ref: library/bdb bdb Bdb canonic8184788 Ref: 321b8184788 Ref: library/bdb bdb Bdb reset8185046 Ref: 321c8185046 Ref: library/bdb bdb Bdb trace_dispatch8185221 Ref: 321d8185221 Ref: library/bdb bdb Bdb dispatch_line8186639 Ref: 321e8186639 Ref: library/bdb bdb Bdb dispatch_call8187113 Ref: 32208187113 Ref: library/bdb bdb Bdb dispatch_return8187594 Ref: 32228187594 Ref: library/bdb bdb Bdb dispatch_exception8188083 Ref: 32248188083 Ref: library/bdb bdb Bdb stop_here8188739 Ref: 32268188739 Ref: library/bdb bdb Bdb break_here8188950 Ref: 32278188950 Ref: library/bdb bdb Bdb break_anywhere8189220 Ref: 32288189220 Ref: library/bdb bdb Bdb user_call8189462 Ref: 32218189462 Ref: library/bdb bdb Bdb user_line8189699 Ref: 321f8189699 Ref: library/bdb bdb Bdb user_return8189907 Ref: 32238189907 Ref: library/bdb bdb Bdb user_exception8190087 Ref: 32258190087 Ref: library/bdb bdb Bdb do_clear8190269 Ref: 32298190269 Ref: library/bdb bdb Bdb set_step8190554 Ref: 322a8190554 Ref: library/bdb bdb Bdb set_next8190624 Ref: 322b8190624 Ref: library/bdb bdb Bdb set_return8190721 Ref: 322c8190721 Ref: library/bdb bdb Bdb set_until8190811 Ref: 322d8190811 Ref: library/bdb bdb Bdb set_trace8190982 Ref: 322e8190982 Ref: library/bdb bdb Bdb set_continue8191141 Ref: 322f8191141 Ref: library/bdb bdb Bdb set_quit8191314 Ref: 32308191314 Ref: library/bdb bdb Bdb set_break8191732 Ref: 32318191732 Ref: library/bdb bdb Bdb clear_break8192083 Ref: 32328192083 Ref: library/bdb bdb Bdb clear_bpbynumber8192253 Ref: 32338192253 Ref: library/bdb bdb Bdb clear_all_file_breaks8192476 Ref: 32348192476 Ref: library/bdb bdb Bdb clear_all_breaks8192635 Ref: 32358192635 Ref: library/bdb bdb Bdb get_bpbynumber8192717 Ref: 32368192717 Ref: library/bdb bdb Bdb get_break8193066 Ref: 32378193066 Ref: library/bdb bdb Bdb get_breaks8193183 Ref: 32388193183 Ref: library/bdb bdb Bdb get_file_breaks8193337 Ref: 32398193337 Ref: library/bdb bdb Bdb get_all_breaks8193475 Ref: 323a8193475 Ref: library/bdb bdb Bdb get_stack8193681 Ref: 323b8193681 Ref: library/bdb bdb Bdb format_stack_entry8193847 Ref: 323c8193847 Ref: library/bdb bdb Bdb run8194434 Ref: 323d8194434 Ref: library/bdb bdb Bdb runeval8194664 Ref: 323e8194664 Ref: library/bdb bdb Bdb runctx8194892 Ref: 323f8194892 Ref: library/bdb bdb Bdb runcall8195028 Ref: 29f8195028 Ref: library/bdb bdb checkfuncname8195194 Ref: 32408195194 Ref: library/bdb bdb effective8195632 Ref: 32418195632 Ref: library/bdb bdb set_trace8195951 Ref: 32428195951 Ref: bdb — Debugger framework-Footnote-18196101 Node: faulthandler — Dump the Python traceback8196163 Ref: library/faulthandler doc8196336 Ref: 32438196336 Ref: library/faulthandler faulthandler-dump-the-python-traceback8196336 Ref: 32448196336 Ref: library/faulthandler module-faulthandler8196336 Ref: 7d8196336 Node: Dumping the traceback8198378 Ref: library/faulthandler dumping-the-traceback8198506 Ref: 32458198506 Ref: library/faulthandler faulthandler dump_traceback8198569 Ref: 6d88198569 Node: Fault handler state8198876 Ref: library/faulthandler fault-handler-state8199051 Ref: 32468199051 Ref: library/faulthandler faulthandler enable8199110 Ref: 5488199110 Ref: library/faulthandler faulthandler disable8199800 Ref: 32488199800 Ref: library/faulthandler faulthandler is_enabled8199941 Ref: 32498199941 Node: Dumping the tracebacks after a timeout8200028 Ref: library/faulthandler dumping-the-tracebacks-after-a-timeout8200220 Ref: 324a8200220 Ref: library/faulthandler faulthandler dump_traceback_later8200317 Ref: 6d98200317 Ref: library/faulthandler faulthandler cancel_dump_traceback_later8201349 Ref: 324b8201349 Node: Dumping the traceback on a user signal8201473 Ref: library/faulthandler dumping-the-traceback-on-a-user-signal8201673 Ref: 324c8201673 Ref: library/faulthandler faulthandler register8201770 Ref: 6d78201770 Ref: library/faulthandler faulthandler unregister8202401 Ref: 324d8202401 Node: Issue with file descriptors8202676 Ref: library/faulthandler faulthandler-fd8202849 Ref: 32478202849 Ref: library/faulthandler issue-with-file-descriptors8202849 Ref: 324e8202849 Node: Example<15>8203317 Ref: library/faulthandler example8203443 Ref: 324f8203443 Node: pdb — The Python Debugger8203989 Ref: library/pdb doc8204156 Ref: 32508204156 Ref: library/pdb debugger8204156 Ref: 32518204156 Ref: library/pdb module-pdb8204156 Ref: c98204156 Ref: library/pdb pdb-the-python-debugger8204156 Ref: 32528204156 Ref: library/pdb pdb run8207366 Ref: 30228207366 Ref: library/pdb pdb runeval8208058 Ref: 32578208058 Ref: library/pdb pdb runcall8208369 Ref: 32588208369 Ref: library/pdb pdb set_trace8208684 Ref: 3c28208684 Ref: library/pdb pdb post_mortem8209100 Ref: d458209100 Ref: library/pdb pdb pm8209391 Ref: 32598209391 Ref: library/pdb pdb Pdb8209735 Ref: 56c8209735 Ref: library/pdb pdb Pdb run8211101 Ref: 325b8211101 Ref: library/pdb pdb Pdb runeval8211161 Ref: 325c8211161 Ref: library/pdb pdb Pdb runcall8211226 Ref: 325d8211226 Ref: library/pdb pdb Pdb set_trace8211277 Ref: 325e8211277 Ref: pdb — The Python Debugger-Footnote-18211444 Ref: pdb — The Python Debugger-Footnote-28211506 Node: Debugger Commands8211639 Ref: library/pdb debugger-commands8211720 Ref: 32538211720 Ref: library/pdb id28211720 Ref: 325f8211720 Ref: library/pdb pdbcommand-help8213994 Ref: 32628213994 Ref: library/pdb pdbcommand-where8214387 Ref: 32638214387 Ref: library/pdb pdbcommand-down8214577 Ref: 32648214577 Ref: library/pdb pdbcommand-up8214716 Ref: 32658214716 Ref: library/pdb pdbcommand-break8214852 Ref: 32668214852 Ref: library/pdb pdbcommand-tbreak8215734 Ref: 32678215734 Ref: library/pdb pdbcommand-clear8215945 Ref: 32688215945 Ref: library/pdb pdbcommand-disable8216253 Ref: 32698216253 Ref: library/pdb pdbcommand-enable8216578 Ref: 326a8216578 Ref: library/pdb pdbcommand-ignore8216668 Ref: 326b8216668 Ref: library/pdb pdbcommand-condition8217061 Ref: 326c8217061 Ref: library/pdb pdbcommand-commands8217354 Ref: 326d8217354 Ref: library/pdb pdbcommand-step8218989 Ref: 32558218989 Ref: library/pdb pdbcommand-next8219174 Ref: 32568219174 Ref: library/pdb pdbcommand-until8219572 Ref: 32718219572 Ref: library/pdb pdbcommand-return8219969 Ref: 326e8219969 Ref: library/pdb pdbcommand-continue8220056 Ref: 32548220056 Ref: library/pdb pdbcommand-jump8220156 Ref: 326f8220156 Ref: library/pdb pdbcommand-list8220586 Ref: 32608220586 Ref: library/pdb pdbcommand-ll8221324 Ref: 32728221324 Ref: library/pdb pdbcommand-args8221502 Ref: 32738221502 Ref: library/pdb pdbcommand-p8221581 Ref: 8878221581 Ref: library/pdb pdbcommand-pp8221850 Ref: 32748221850 Ref: library/pdb pdbcommand-whatis8222013 Ref: 32758222013 Ref: library/pdb pdbcommand-source8222090 Ref: 32768222090 Ref: library/pdb pdbcommand-display8222217 Ref: 32778222217 Ref: library/pdb pdbcommand-undisplay8222474 Ref: 32788222474 Ref: library/pdb pdbcommand-interact8222690 Ref: 32798222690 Ref: library/pdb debugger-aliases8222919 Ref: 32618222919 Ref: library/pdb pdbcommand-alias8222919 Ref: 327a8222919 Ref: library/pdb pdbcommand-unalias8224016 Ref: 327b8224016 Ref: library/pdb pdbcommand-!8224080 Ref: 327c8224080 Ref: library/pdb pdbcommand-run8224521 Ref: 327d8224521 Ref: library/pdb pdbcommand-restart8224552 Ref: 327e8224552 Ref: library/pdb pdbcommand-quit8224891 Ref: 32708224891 Ref: library/pdb pdbcommand-debug8224985 Ref: 327f8224985 Ref: library/pdb pdbcommand-retval8225184 Ref: 32808225184 Node: The Python Profilers8225272 Ref: library/profile doc8225453 Ref: 32818225453 Ref: library/profile profile8225453 Ref: 32828225453 Ref: library/profile the-python-profilers8225453 Ref: 32838225453 Ref: The Python Profilers-Footnote-18225897 Ref: The Python Profilers-Footnote-28225963 Node: Introduction to the profilers8226028 Ref: library/profile introduction-to-the-profilers8226146 Ref: 32848226146 Ref: library/profile profiler-introduction8226146 Ref: 32858226146 Node: Instant User’s Manual8227632 Ref: library/profile instant-user-s-manual8227796 Ref: 32868227796 Ref: library/profile profile-instant8227796 Ref: 32878227796 Node: profile and cProfile Module Reference8233971 Ref: library/profile module-cProfile8234121 Ref: 288234121 Ref: library/profile profile-and-cprofile-module-reference8234121 Ref: 328c8234121 Ref: library/profile module-profile8234232 Ref: d38234232 Ref: library/profile profile run8234326 Ref: 328d8234326 Ref: library/profile profile runctx8234961 Ref: 328e8234961 Ref: library/profile profile Profile8235363 Ref: 1bb8235363 Ref: library/profile profile Profile enable8236931 Ref: 328f8236931 Ref: library/profile profile Profile disable8237032 Ref: 32908237032 Ref: library/profile profile Profile create_stats8237133 Ref: 32918237133 Ref: library/profile profile Profile print_stats8237277 Ref: 32928237277 Ref: library/profile profile Profile dump_stats8237435 Ref: 32938237435 Ref: library/profile profile Profile run8237542 Ref: 32948237542 Ref: library/profile profile Profile runctx8237620 Ref: 32958237620 Ref: library/profile profile Profile runcall8237777 Ref: 29e8237777 Node: The Stats Class8238118 Ref: library/profile profile-stats8238277 Ref: 32968238277 Ref: library/profile the-stats-class8238277 Ref: 32978238277 Ref: library/profile module-pstats8238409 Ref: d48238409 Ref: library/profile pstats Stats8238411 Ref: 32888238411 Ref: library/profile pstats Stats strip_dirs8239674 Ref: 328a8239674 Ref: library/profile pstats Stats add8240496 Ref: 32988240496 Ref: library/profile pstats Stats dump_stats8240989 Ref: 32998240989 Ref: library/profile pstats Stats sort_stats8241370 Ref: 32898241370 Ref: library/profile pstats Stats reverse_order8246727 Ref: 329a8246727 Ref: library/profile pstats Stats print_stats8247013 Ref: 328b8247013 Ref: library/profile pstats Stats print_callers8248457 Ref: 329b8248457 Ref: library/profile pstats Stats print_callees8249573 Ref: 329c8249573 Node: What Is Deterministic Profiling?8249954 Ref: library/profile deterministic-profiling8250087 Ref: 329d8250087 Ref: library/profile what-is-deterministic-profiling8250087 Ref: 329e8250087 Node: Limitations8251885 Ref: library/profile limitations8252014 Ref: 329f8252014 Ref: library/profile profile-limitations8252014 Ref: 32a08252014 Node: Calibration8253897 Ref: library/profile calibration8254014 Ref: 32a18254014 Ref: library/profile profile-calibration8254014 Ref: 32a28254014 Node: Using a custom timer8255709 Ref: library/profile profile-timers8255806 Ref: 32a38255806 Ref: library/profile using-a-custom-timer8255806 Ref: 32a48255806 Node: timeit — Measure execution time of small code snippets8258256 Ref: library/timeit doc8258461 Ref: 32a58258461 Ref: library/timeit module-timeit8258461 Ref: 10b8258461 Ref: library/timeit timeit-measure-execution-time-of-small-code-snippets8258461 Ref: 32a68258461 Ref: timeit — Measure execution time of small code snippets-Footnote-18259228 Node: Basic Examples<2>8259293 Ref: library/timeit basic-examples8259428 Ref: 32a98259428 Node: Python Interface8260716 Ref: library/timeit id18260885 Ref: 32ab8260885 Ref: library/timeit python-interface8260885 Ref: 32a88260885 Ref: library/timeit timeit timeit8261006 Ref: 7718261006 Ref: library/timeit timeit repeat8261469 Ref: 32ad8261469 Ref: library/timeit timeit default_timer8262059 Ref: 32af8262059 Ref: library/timeit timeit Timer8262264 Ref: 32ac8262264 Ref: library/timeit timeit Timer timeit8263711 Ref: 59c8263711 Ref: library/timeit timeit Timer autorange8264820 Ref: 59b8264820 Ref: library/timeit timeit Timer repeat8265547 Ref: 32ae8265547 Ref: library/timeit timeit Timer print_exc8266822 Ref: 32b08266822 Node: Command-Line Interface<4>8267402 Ref: library/timeit command-line-interface8267566 Ref: 32b18267566 Ref: library/timeit timeit-command-line-interface8267566 Ref: 32a78267566 Ref: library/timeit cmdoption-timeit-n8267825 Ref: 32b28267825 Ref: library/timeit cmdoption-timeit-r8267911 Ref: 32b38267911 Ref: library/timeit cmdoption-timeit-s8268002 Ref: 32b48268002 Ref: library/timeit cmdoption-timeit-p8268106 Ref: 32b58268106 Ref: library/timeit cmdoption-timeit-u8268327 Ref: 32b68268327 Ref: library/timeit cmdoption-timeit-v8268472 Ref: 32b78268472 Ref: library/timeit cmdoption-timeit-h8268572 Ref: 32b88268572 Node: Examples<25>8269791 Ref: library/timeit examples8269930 Ref: 32b98269930 Ref: library/timeit timeit-examples8269930 Ref: 32aa8269930 Node: trace — Trace or track Python statement execution8273147 Ref: library/trace doc8273372 Ref: 32ba8273372 Ref: library/trace module-trace8273372 Ref: 1128273372 Ref: library/trace trace-trace-or-track-python-statement-execution8273372 Ref: 32bb8273372 Ref: trace — Trace or track Python statement execution-Footnote-18274117 Ref: trace — Trace or track Python statement execution-Footnote-28274181 Node: Command-Line Usage8274222 Ref: library/trace command-line-usage8274359 Ref: 32bc8274359 Ref: library/trace trace-cli8274359 Ref: 32bd8274359 Ref: library/trace cmdoption-trace-help8274713 Ref: 32be8274713 Ref: library/trace cmdoption-trace-version8274771 Ref: 32bf8274771 Node: Main options8274995 Ref: library/trace main-options8275080 Ref: 32c08275080 Ref: library/trace cmdoption-trace-c8275470 Ref: 32c38275470 Ref: library/trace cmdoption-trace-t8275737 Ref: 32c28275737 Ref: library/trace cmdoption-trace-l8275812 Ref: 32c18275812 Ref: library/trace cmdoption-trace-r8275910 Ref: 32c78275910 Ref: library/trace cmdoption-trace-trackcalls8276116 Ref: 32c88276116 Node: Modifiers8276226 Ref: library/trace modifiers8276327 Ref: 32c98276327 Ref: library/trace cmdoption-trace-f8276366 Ref: 32c58276366 Ref: library/trace cmdoption-trace-coverdir8276533 Ref: 32c48276533 Ref: library/trace cmdoption-trace-m8276731 Ref: 32ca8276731 Ref: library/trace cmdoption-trace-s8276867 Ref: 32cb8276867 Ref: library/trace cmdoption-trace-no-report8277029 Ref: 32c68277029 Ref: library/trace cmdoption-trace-g8277260 Ref: 32cc8277260 Node: Filters8277389 Ref: library/trace filters8277469 Ref: 32cd8277469 Ref: library/trace cmdoption-trace-ignore-module8277551 Ref: 32ce8277551 Ref: library/trace cmdoption-trace-ignore-dir8277748 Ref: 32cf8277748 Node: Programmatic Interface8277958 Ref: library/trace programmatic-interface8278095 Ref: 32d08278095 Ref: library/trace trace-api8278095 Ref: 32d18278095 Ref: library/trace trace Trace8278160 Ref: 32d28278160 Ref: library/trace trace Trace run8279071 Ref: 32d38279071 Ref: library/trace trace Trace runctx8279313 Ref: 32d48279313 Ref: library/trace trace Trace runfunc8279627 Ref: 2a08279627 Ref: library/trace trace Trace results8279817 Ref: 32d58279817 Ref: library/trace trace CoverageResults8280126 Ref: 32d68280126 Ref: library/trace trace CoverageResults update8280290 Ref: 32d78280290 Ref: library/trace trace CoverageResults write_results8280408 Ref: 32d88280408 Node: tracemalloc — Trace memory allocations8281438 Ref: library/tracemalloc doc8281598 Ref: 32d98281598 Ref: library/tracemalloc module-tracemalloc8281598 Ref: 1148281598 Ref: library/tracemalloc tracemalloc-trace-memory-allocations8281598 Ref: 32da8281598 Ref: tracemalloc — Trace memory allocations-Footnote-18282935 Node: Examples<26>8283005 Ref: library/tracemalloc examples8283106 Ref: 32db8283106 Node: Display the top 108283255 Ref: library/tracemalloc display-the-top-108283350 Ref: 32dc8283350 Node: Compute differences8284834 Ref: library/tracemalloc compute-differences8284973 Ref: 32de8284973 Node: Get the traceback of a memory block8287163 Ref: library/tracemalloc get-the-traceback-of-a-memory-block8287294 Ref: 32e18287294 Node: Pretty top8289926 Ref: library/tracemalloc pretty-top8290029 Ref: 32e28290029 Node: API8292416 Ref: library/tracemalloc api8292517 Ref: 32e38292517 Node: Functions<9>8292688 Ref: library/tracemalloc functions8292761 Ref: 32e48292761 Ref: library/tracemalloc tracemalloc clear_traces8292800 Ref: 32e58292800 Ref: library/tracemalloc tracemalloc get_object_traceback8292935 Ref: 32e78292935 Ref: library/tracemalloc tracemalloc get_traceback_limit8293343 Ref: 32e98293343 Ref: library/tracemalloc tracemalloc get_traced_memory8293666 Ref: 32ea8293666 Ref: library/tracemalloc tracemalloc get_tracemalloc_memory8293872 Ref: 32eb8293872 Ref: library/tracemalloc tracemalloc is_tracing8294070 Ref: 32ec8294070 Ref: library/tracemalloc tracemalloc start8294302 Ref: fea8294302 Ref: library/tracemalloc tracemalloc stop8295501 Ref: 32e68295501 Ref: library/tracemalloc tracemalloc take_snapshot8295934 Ref: 32ee8295934 Node: DomainFilter8296632 Ref: library/tracemalloc domainfilter8296720 Ref: 32f08296720 Ref: library/tracemalloc tracemalloc DomainFilter8296765 Ref: 5a08296765 Ref: library/tracemalloc tracemalloc DomainFilter inclusive8296929 Ref: 32f18296929 Ref: library/tracemalloc tracemalloc DomainFilter domain8297229 Ref: 32f28297229 Node: Filter8297334 Ref: library/tracemalloc filter8297415 Ref: 32f38297415 Ref: library/tracemalloc tracemalloc Filter8297448 Ref: 32f48297448 Ref: library/tracemalloc tracemalloc Filter domain8298295 Ref: 32f58298295 Ref: library/tracemalloc tracemalloc Filter inclusive8298566 Ref: 32f68298566 Ref: library/tracemalloc tracemalloc Filter lineno8298998 Ref: 32f88298998 Ref: library/tracemalloc tracemalloc Filter filename_pattern8299150 Ref: 32f78299150 Ref: library/tracemalloc tracemalloc Filter all_frames8299264 Ref: 32f98299264 Node: Frame8299671 Ref: 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Ref: library/tracemalloc statistic8303819 Ref: 330c8303819 Ref: library/tracemalloc tracemalloc Statistic8303860 Ref: 33088303860 Ref: library/tracemalloc tracemalloc Statistic count8304084 Ref: 33048304084 Ref: library/tracemalloc tracemalloc Statistic size8304159 Ref: 33098304159 Ref: library/tracemalloc tracemalloc Statistic traceback8304246 Ref: 330a8304246 Node: StatisticDiff8304378 Ref: library/tracemalloc statisticdiff8304463 Ref: 330d8304463 Ref: library/tracemalloc tracemalloc StatisticDiff8304512 Ref: 33008304512 Ref: library/tracemalloc tracemalloc StatisticDiff count8304812 Ref: 330e8304812 Ref: library/tracemalloc tracemalloc StatisticDiff count_diff8304986 Ref: 33038304986 Ref: library/tracemalloc tracemalloc StatisticDiff size8305208 Ref: 33028305208 Ref: library/tracemalloc tracemalloc StatisticDiff size_diff8305404 Ref: 33018305404 Ref: library/tracemalloc tracemalloc StatisticDiff traceback8305638 Ref: 33058305638 Node: Trace8305772 Ref: library/tracemalloc trace8305857 Ref: 330f8305857 Ref: library/tracemalloc tracemalloc Trace8305890 Ref: 330b8305890 Ref: library/tracemalloc tracemalloc Trace domain8306123 Ref: 33108306123 Ref: library/tracemalloc tracemalloc Trace size8306401 Ref: 33118306401 Ref: library/tracemalloc tracemalloc Trace traceback8306485 Ref: 33128306485 Node: Traceback8306617 Ref: library/tracemalloc traceback8306680 Ref: 33138306680 Ref: library/tracemalloc tracemalloc Traceback8306721 Ref: 3ff8306721 Ref: library/tracemalloc tracemalloc Traceback format8307442 Ref: 4008307442 Node: Software Packaging and Distribution8308525 Ref: library/distribution doc8308688 Ref: 33158308688 Ref: library/distribution software-packaging-and-distribution8308688 Ref: 33168308688 Ref: Software Packaging and Distribution-Footnote-18309272 Node: distutils — Building and installing Python modules8309297 Ref: library/distutils doc8309475 Ref: 33178309475 Ref: library/distutils distutils-building-and-installing-python-modules8309475 Ref: 33188309475 Ref: library/distutils module-distutils8309475 Ref: 398309475 Ref: distutils — Building and installing Python modules-Footnote-18311382 Ref: distutils — Building and installing Python modules-Footnote-28311435 Ref: distutils — Building and installing Python modules-Footnote-38311464 Node: ensurepip — Bootstrapping the pip installer8311501 Ref: library/ensurepip doc8311729 Ref: 33198311729 Ref: library/ensurepip ensurepip-bootstrapping-the-pip-installer8311729 Ref: 331a8311729 Ref: library/ensurepip module-ensurepip8311729 Ref: 7a8311729 Ref: ensurepip — Bootstrapping the pip installer-Footnote-18313134 Node: Command line interface8313183 Ref: library/ensurepip command-line-interface8313306 Ref: 331b8313306 Node: Module API8315087 Ref: library/ensurepip module-api8315210 Ref: 331c8315210 Ref: library/ensurepip ensurepip version8315317 Ref: 331d8315317 Ref: library/ensurepip ensurepip bootstrap8315477 Ref: 31f28315477 Node: venv — Creation of virtual environments8317252 Ref: library/venv doc8317476 Ref: 331e8317476 Ref: library/venv module-venv8317476 Ref: 1258317476 Ref: library/venv venv-creation-of-virtual-environments8317476 Ref: 331f8317476 Ref: venv — Creation of virtual environments-Footnote-18318404 Ref: venv — Creation of virtual environments-Footnote-28318465 Ref: venv — Creation of virtual environments-Footnote-38318514 Node: Creating virtual environments8318637 Ref: library/venv creating-virtual-environments8318759 Ref: 33208318759 Ref: library/venv venv-def8325765 Ref: 33218325765 Ref: Creating virtual environments-Footnote-18328740 Ref: Creating virtual environments-Footnote-28328814 Ref: Creating virtual environments-Footnote-38328869 Ref: Creating virtual environments-Footnote-48328914 Ref: Creating virtual environments-Footnote-58328952 Node: API<2>8329001 Ref: library/venv api8329166 Ref: 33258329166 Ref: library/venv venv-api8329166 Ref: 7f28329166 Ref: library/venv venv EnvBuilder8329423 Ref: 9088329423 Ref: library/venv venv EnvBuilder create8331126 Ref: 33268331126 Ref: library/venv venv EnvBuilder ensure_directories8332421 Ref: 33278332421 Ref: library/venv venv EnvBuilder create_configuration8332875 Ref: 33288332875 Ref: library/venv venv EnvBuilder setup_python8333013 Ref: 33298333013 Ref: library/venv venv EnvBuilder setup_scripts8333379 Ref: 332a8333379 Ref: library/venv venv EnvBuilder post_setup8333528 Ref: 332b8333528 Ref: library/venv venv EnvBuilder install_scripts8334525 Ref: 332c8334525 Ref: library/venv venv create8335807 Ref: 9098335807 Node: An example of extending EnvBuilder8336248 Ref: library/venv an-example-of-extending-envbuilder8336375 Ref: 332d8336375 Ref: An example of extending EnvBuilder-Footnote-18347110 Node: zipapp — Manage executable Python zip archives8347157 Ref: library/zipapp doc8347327 Ref: 332e8347327 Ref: library/zipapp module-zipapp8347327 Ref: 1418347327 Ref: library/zipapp pip8347327 Ref: 332f8347327 Ref: library/zipapp zipapp-manage-executable-python-zip-archives8347327 Ref: 33308347327 Ref: zipapp — Manage executable Python zip archives-Footnote-18348103 Node: Basic Example8348168 Ref: library/zipapp basic-example8348300 Ref: 33338348300 Node: Command-Line Interface<5>8348705 Ref: library/zipapp command-line-interface8348856 Ref: 33348348856 Ref: library/zipapp zipapp-command-line-interface8348856 Ref: 33318348856 Ref: library/zipapp cmdoption-zipapp-o8349352 Ref: 33358349352 Ref: library/zipapp cmdoption-zipapp-p8349857 Ref: 33368349857 Ref: library/zipapp cmdoption-zipapp-m8350141 Ref: 33378350141 Ref: library/zipapp cmdoption-zipapp-c8350580 Ref: 33388350580 Ref: library/zipapp cmdoption-zipapp-info8350865 Ref: 33398350865 Ref: library/zipapp cmdoption-zipapp-h8351076 Ref: 333a8351076 Node: Python API8351152 Ref: library/zipapp python-api8351302 Ref: 333b8351302 Ref: library/zipapp zipapp-python-api8351302 Ref: 33328351302 Ref: library/zipapp zipapp create_archive8351390 Ref: 41d8351390 Ref: library/zipapp zipapp get_interpreter8355173 Ref: 333c8355173 Node: Examples<27>8355530 Ref: library/zipapp examples8355681 Ref: 333d8355681 Ref: library/zipapp zipapp-examples8355681 Ref: 333e8355681 Node: Specifying the Interpreter8357046 Ref: library/zipapp specifying-the-interpreter8357231 Ref: 333f8357231 Ref: library/zipapp zipapp-specifying-the-interpreter8357231 Ref: 33408357231 Node: Creating Standalone Applications with zipapp8358470 Ref: library/zipapp creating-standalone-applications-with-zipapp8358684 Ref: 33418358684 Node: Making a Windows executable8360726 Ref: library/zipapp making-a-windows-executable8360850 Ref: 33428360850 Node: Caveats8363977 Ref: library/zipapp caveats8364101 Ref: 33438364101 Node: The Python Zip Application Archive Format8365891 Ref: library/zipapp the-python-zip-application-archive-format8366070 Ref: 33448366070 Node: Python Runtime Services8367973 Ref: library/python doc8368139 Ref: 33458368139 Ref: library/python python8368139 Ref: 33468368139 Ref: library/python python-runtime-services8368139 Ref: 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library/sys sys breakpointhook8377088 Ref: 3138377088 Ref: library/sys sys _debugmallocstats8378986 Ref: 334e8378986 Ref: library/sys sys dllhandle8379412 Ref: 334f8379412 Ref: library/sys sys displayhook8379533 Ref: e5f8379533 Ref: library/sys sys dont_write_bytecode8381060 Ref: 33518381060 Ref: library/sys sys pycache_prefix8381457 Ref: 1568381457 Ref: library/sys sys excepthook8382428 Ref: e638382428 Ref: library/sys sys __breakpointhook__8383753 Ref: 33528383753 Ref: library/sys sys __displayhook__8383786 Ref: 33538383786 Ref: library/sys sys __excepthook__8383816 Ref: 33548383816 Ref: library/sys sys __unraisablehook__8383845 Ref: 33558383845 Ref: library/sys sys exc_info8384353 Ref: c5f8384353 Ref: library/sys sys exec_prefix8385575 Ref: 33238385575 Ref: library/sys sys executable8386495 Ref: 2748386495 Ref: library/sys sys exit8386796 Ref: ce28386796 Ref: library/sys sys flags8388468 Ref: b3c8388468 Ref: library/sys sys float_info8391452 Ref: 12c68391452 Ref: library/sys sys float_repr_style8396405 Ref: c908396405 Ref: library/sys sys getallocatedblocks8396944 Ref: 8e28396944 Ref: library/sys sys getandroidapilevel8397581 Ref: 3f18397581 Ref: library/sys sys getcheckinterval8397755 Ref: e088397755 Ref: library/sys sys getdefaultencoding8397977 Ref: 33598397977 Ref: library/sys sys getdlopenflags8398120 Ref: e4e8398120 Ref: library/sys sys getfilesystemencoding8398431 Ref: 4f68398431 Ref: library/sys sys getfilesystemencodeerrors8399839 Ref: 5948399839 Ref: library/sys sys getrefcount8400242 Ref: 335a8400242 Ref: library/sys sys getrecursionlimit8400500 Ref: e7a8400500 Ref: library/sys sys getsizeof8400812 Ref: 32e88400812 Ref: library/sys sys getswitchinterval8401764 Ref: 33588401764 Ref: library/sys sys _getframe8401934 Ref: e648401934 Ref: library/sys sys getprofile8402581 Ref: d478402581 Ref: library/sys sys gettrace8402681 Ref: d488402681 Ref: library/sys sys getwindowsversion8403119 Ref: 5958403119 Ref: library/sys sys get_asyncgen_hooks8405422 Ref: 335b8405422 Ref: library/sys sys get_coroutine_origin_tracking_depth8406029 Ref: 3f28406029 Ref: library/sys sys hash_info8406379 Ref: 9218406379 Ref: library/sys sys hexversion8408080 Ref: 335d8408080 Ref: library/sys sys implementation8408973 Ref: 9aa8408973 Ref: library/sys sys int_info8411174 Ref: c218411174 Ref: library/sys sys __interactivehook__8412036 Ref: 8e48412036 Ref: library/sys sys intern8412581 Ref: c6e8412581 Ref: library/sys sys is_finalizing8413349 Ref: 7628413349 Ref: library/sys sys last_type8413530 Ref: c5a8413530 Ref: library/sys sys last_value8413554 Ref: 335f8413554 Ref: library/sys sys last_traceback8413579 Ref: 325a8413579 Ref: library/sys sys maxsize8414233 Ref: b438414233 Ref: library/sys sys maxunicode8414449 Ref: 98b8414449 Ref: library/sys sys meta_path8414848 Ref: 5e68414848 Ref: library/sys sys modules8416089 Ref: 11528416089 Ref: library/sys sys path8416446 Ref: 4888416446 Ref: library/sys sys path_hooks8417538 Ref: 95c8417538 Ref: library/sys sys path_importer_cache8417829 Ref: 49d8417829 Ref: library/sys sys platform8418355 Ref: 2b18418355 Ref: library/sys sys prefix8420774 Ref: 33228420774 Ref: library/sys sys ps18421671 Ref: ff18421671 Ref: library/sys sys ps28421689 Ref: ff28421689 Ref: library/sys sys setcheckinterval8422165 Ref: 33578422165 Ref: library/sys sys setdlopenflags8422954 Ref: a668422954 Ref: library/sys sys setprofile8423553 Ref: e3d8423553 Ref: library/sys sys setrecursionlimit8425692 Ref: e7b8425692 Ref: library/sys sys setswitchinterval8426484 Ref: beb8426484 Ref: library/sys sys settrace8427061 Ref: e3e8427061 Ref: library/sys sys set_asyncgen_hooks8431595 Ref: 11b28431595 Ref: library/sys sys set_coroutine_origin_tracking_depth8432697 Ref: 3f38432697 Ref: library/sys sys _enablelegacywindowsfsencoding8433512 Ref: 4f88433512 Ref: library/sys sys stdin8433977 Ref: 30d8433977 Ref: library/sys sys stdout8433997 Ref: 30e8433997 Ref: library/sys sys stderr8434018 Ref: 30f8434018 Ref: library/sys sys __stdin__8436907 Ref: 33618436907 Ref: library/sys sys __stdout__8436931 Ref: 195e8436931 Ref: library/sys sys __stderr__8436956 Ref: 33628436956 Ref: library/sys sys thread_info8437921 Ref: aa28437921 Ref: library/sys sys tracebacklimit8439372 Ref: 33638439372 Ref: library/sys sys unraisablehook8439736 Ref: 22d8439736 Ref: library/sys sys version8441470 Ref: 5d38441470 Ref: library/sys sys api_version8441872 Ref: 33648441872 Ref: library/sys sys version_info8442060 Ref: b1a8442060 Ref: library/sys sys warnoptions8442681 Ref: 4168442681 Ref: library/sys sys winver8442900 Ref: 33658442900 Ref: library/sys sys _xoptions8443337 Ref: fec8443337 Ref: library/sys c998444136 Ref: 33568444136 Ref: sys — System-specific parameters and functions-Footnote-18444347 Ref: sys — System-specific parameters and functions-Footnote-28444396 Ref: sys — System-specific parameters and functions-Footnote-38444445 Ref: sys — System-specific parameters and functions-Footnote-48444494 Ref: sys — System-specific parameters and functions-Footnote-58444546 Ref: sys — System-specific parameters and functions-Footnote-68444595 Ref: sys — System-specific parameters and functions-Footnote-78444644 Ref: sys — System-specific parameters and functions-Footnote-88444693 Ref: sys — System-specific parameters and functions-Footnote-98444742 Ref: sys — System-specific parameters and functions-Footnote-108444791 Ref: sys — System-specific parameters and functions-Footnote-118444841 Ref: sys — System-specific parameters and functions-Footnote-128444891 Ref: sys — System-specific parameters and functions-Footnote-138444941 Ref: sys — System-specific parameters and functions-Footnote-148444991 Ref: sys — System-specific parameters and functions-Footnote-158445041 Ref: sys — System-specific parameters and functions-Footnote-168445121 Ref: sys — System-specific parameters and functions-Footnote-178445171 Ref: sys — System-specific parameters and functions-Footnote-188445221 Node: sysconfig — Provide access to Python’s configuration information8445271 Ref: library/sysconfig doc8445494 Ref: 33668445494 Ref: library/sysconfig module-sysconfig8445494 Ref: fe8445494 Ref: library/sysconfig sysconfig-provide-access-to-python-s-configuration-information8445494 Ref: 33678445494 Ref: sysconfig — Provide access to Python’s configuration information-Footnote-18446136 Node: Configuration variables8446204 Ref: library/sysconfig configuration-variables8446359 Ref: 33688446359 Ref: library/sysconfig sysconfig get_config_vars8446852 Ref: 9658446852 Ref: library/sysconfig sysconfig get_config_var8447223 Ref: 9648447223 Node: Installation paths8447666 Ref: library/sysconfig installation-paths8447848 Ref: 33698447848 Ref: library/sysconfig sysconfig get_scheme_names8449823 Ref: 336a8449823 Ref: library/sysconfig sysconfig get_path_names8449961 Ref: 336b8449961 Ref: library/sysconfig sysconfig get_path8450100 Ref: cbe8450100 Ref: library/sysconfig sysconfig get_paths8451309 Ref: bd98451309 Node: Other functions<3>8451932 Ref: library/sysconfig other-functions8452118 Ref: 336c8452118 Ref: library/sysconfig sysconfig get_python_version8452169 Ref: bd88452169 Ref: library/sysconfig sysconfig get_platform8452340 Ref: bd78452340 Ref: library/sysconfig sysconfig is_python_build8453346 Ref: cbf8453346 Ref: library/sysconfig sysconfig parse_config_h8453637 Ref: 336d8453637 Ref: library/sysconfig sysconfig get_config_h_filename8454031 Ref: 336e8454031 Ref: library/sysconfig sysconfig get_makefile_filename8454124 Ref: 336f8454124 Node: Using sysconfig as a script8454215 Ref: library/sysconfig using-sysconfig-as-a-script8454374 Ref: 33708454374 Node: builtins — Built-in objects8455447 Ref: library/builtins doc8455663 Ref: 33718455663 Ref: library/builtins builtins-built-in-objects8455663 Ref: 33728455663 Ref: library/builtins module-builtins8455663 Ref: 138455663 Node: __main__ — Top-level script environment8457164 Ref: library/__main__ doc8457340 Ref: 33738457340 Ref: library/__main__ main-top-level-script-environment8457340 Ref: 33748457340 Ref: library/__main__ module-__main__8457340 Ref: 18457340 Node: warnings — Warning control8458234 Ref: library/warnings doc8458409 Ref: 33758458409 Ref: library/warnings module-warnings8458409 Ref: 1268458409 Ref: library/warnings warnings-warning-control8458409 Ref: 33768458409 Ref: warnings — Warning control-Footnote-18460720 Node: Warning Categories8460787 Ref: library/warnings id18460898 Ref: 337a8460898 Ref: library/warnings warning-categories8460898 Ref: 13c18460898 Node: The Warnings Filter8464880 Ref: library/warnings the-warnings-filter8465032 Ref: 337b8465032 Ref: library/warnings warning-filter8465032 Ref: fe78465032 Node: Describing Warning Filters8467767 Ref: library/warnings describing-warning-filters8467880 Ref: fe88467880 Ref: library/warnings id28467880 Ref: 337c8467880 Node: Default Warning Filter8469675 Ref: library/warnings default-warning-filter8469826 Ref: 337d8469826 Ref: library/warnings id38469826 Ref: 337e8469826 Node: Overriding the default filter8470913 Ref: library/warnings overriding-the-default-filter8471029 Ref: 337f8471029 Ref: library/warnings warning-disable8471029 Ref: 33808471029 Node: Temporarily Suppressing Warnings8472464 Ref: library/warnings temporarily-suppressing-warnings8472614 Ref: 33818472614 Ref: library/warnings warning-suppress8472614 Ref: 33828472614 Node: Testing Warnings8473632 Ref: library/warnings testing-warnings8473809 Ref: 33838473809 Ref: library/warnings warning-testing8473809 Ref: 33848473809 Node: Updating Code For New Versions of Dependencies8475873 Ref: library/warnings updating-code-for-new-versions-of-dependencies8476037 Ref: 33858476037 Ref: library/warnings warning-ignored8476037 Ref: 308a8476037 Node: Available Functions8477427 Ref: library/warnings available-functions8477601 Ref: 33868477601 Ref: library/warnings warning-functions8477601 Ref: 33878477601 Ref: library/warnings warnings warn8477660 Ref: e588477660 Ref: library/warnings warnings warn_explicit8478879 Ref: 5b08478879 Ref: library/warnings warnings showwarning8480067 Ref: 33798480067 Ref: library/warnings warnings formatwarning8480705 Ref: 1dad8480705 Ref: library/warnings warnings filterwarnings8481137 Ref: e078481137 Ref: library/warnings warnings simplefilter8481813 Ref: 317c8481813 Ref: library/warnings warnings resetwarnings8482248 Ref: 33788482248 Node: Available Context Managers8482516 Ref: library/warnings available-context-managers8482635 Ref: 33888482635 Ref: library/warnings warnings catch_warnings8482710 Ref: 317b8482710 Node: dataclasses — Data Classes8483959 Ref: library/dataclasses doc8484145 Ref: 33898484145 Ref: library/dataclasses dataclasses-data-classes8484145 Ref: 338a8484145 Ref: library/dataclasses module-dataclasses8484145 Ref: 308484145 Ref: dataclasses — Data Classes-Footnote-18485806 Ref: dataclasses — Data Classes-Footnote-28485876 Ref: dataclasses — Data Classes-Footnote-38485925 Node: Module-level decorators classes and 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contexts-Footnote-18512617 Node: Utilities8512686 Ref: library/contextlib utilities8512816 Ref: 33a08512816 Ref: library/contextlib contextlib AbstractContextManager8512888 Ref: 5348512888 Ref: library/contextlib contextlib AbstractAsyncContextManager8513374 Ref: 3788513374 Ref: library/contextlib contextlib contextmanager8513881 Ref: b7e8513881 Ref: library/contextlib contextlib asynccontextmanager8516849 Ref: 3778516849 Ref: library/contextlib contextlib closing8517859 Ref: 33a18517859 Ref: library/contextlib simplifying-support-for-single-optional-context-managers8518654 Ref: 33a28518654 Ref: library/contextlib contextlib nullcontext8518654 Ref: 3758518654 Ref: library/contextlib contextlib suppress8519766 Ref: 82c8519766 Ref: library/contextlib contextlib redirect_stdout8520871 Ref: 6c28520871 Ref: library/contextlib contextlib redirect_stderr8522207 Ref: 6c18522207 Ref: library/contextlib contextlib ContextDecorator8522469 Ref: b7d8522469 Ref: library/contextlib contextlib ExitStack8524863 Ref: 3768524863 Ref: library/contextlib contextlib ExitStack enter_context8526729 Ref: 33a48526729 Ref: library/contextlib contextlib ExitStack push8527161 Ref: 33a58527161 Ref: library/contextlib contextlib ExitStack callback8528049 Ref: 2a58528049 Ref: library/contextlib contextlib ExitStack pop_all8528502 Ref: 33a68528502 Ref: library/contextlib contextlib ExitStack close8529554 Ref: 33a78529554 Ref: library/contextlib contextlib AsyncExitStack8529842 Ref: 3798529842 Ref: library/contextlib contextlib AsyncExitStack enter_async_context8530203 Ref: 33a98530203 Ref: library/contextlib contextlib AsyncExitStack push_async_exit8530345 Ref: 33aa8530345 Ref: library/contextlib contextlib AsyncExitStack push_async_callback8530507 Ref: 2a68530507 Ref: library/contextlib contextlib AsyncExitStack aclose8530644 Ref: 33a88530644 Node: Examples and Recipes<2>8531218 Ref: library/contextlib examples-and-recipes8531407 Ref: 33ab8531407 Node: Supporting a variable number of context managers8531855 Ref: library/contextlib supporting-a-variable-number-of-context-managers8532014 Ref: 33ac8532014 Node: Catching exceptions from __enter__ methods8533056 Ref: library/contextlib catching-exceptions-from-enter-methods8533266 Ref: 33ad8533266 Node: Cleaning up in an __enter__ implementation8534414 Ref: library/contextlib cleaning-up-in-an-enter-implementation8534627 Ref: 33ae8534627 Node: Replacing any use of try-finally and flag variables8536530 Ref: library/contextlib replacing-any-use-of-try-finally-and-flag-variables8536748 Ref: 33af8536748 Node: Using a context manager as a function decorator8539277 Ref: library/contextlib using-a-context-manager-as-a-function-decorator8539444 Ref: 33b08539444 Ref: Using a context manager as a function decorator-Footnote-18541278 Node: Single use reusable and reentrant context managers8541327 Ref: library/contextlib single-use-reusable-and-reentrant-cms8541498 Ref: 82e8541498 Ref: library/contextlib single-use-reusable-and-reentrant-context-managers8541498 Ref: 33b18541498 Node: Reentrant context managers8543035 Ref: library/contextlib reentrant-cms8543182 Ref: 33a38543182 Ref: library/contextlib reentrant-context-managers8543182 Ref: 33b28543182 Node: Reusable context managers8544698 Ref: library/contextlib reusable-cms8544845 Ref: 33b38544845 Ref: library/contextlib reusable-context-managers8544845 Ref: 33b48544845 Node: abc — Abstract Base Classes8547523 Ref: library/abc doc8547706 Ref: 33b58547706 Ref: library/abc abc-abstract-base-classes8547706 Ref: 33b68547706 Ref: library/abc module-abc8547706 Ref: 48547706 Ref: library/abc abc ABC8548671 Ref: 8188548671 Ref: library/abc abc ABCMeta8549516 Ref: 8198549516 Ref: library/abc abc ABCMeta register8550296 Ref: 9d18550296 Ref: library/abc abc ABCMeta __subclasshook__8550978 Ref: 33b78550978 Ref: library/abc abc abstractmethod8553875 Ref: 9ce8553875 Ref: library/abc abc abstractclassmethod8556975 Ref: 9cf8556975 Ref: library/abc abc abstractstaticmethod8557691 Ref: 9d08557691 Ref: library/abc abc abstractproperty8558409 Ref: 9cd8558409 Ref: library/abc abc get_cache_token8559796 Ref: 8178559796 Ref: abc — Abstract Base Classes-Footnote-18560209 Ref: abc — Abstract Base Classes-Footnote-28560271 Ref: abc — Abstract Base Classes-Footnote-38560320 Ref: abc — Abstract Base Classes-Footnote-48560369 Node: atexit — Exit handlers8560480 Ref: library/atexit doc8560660 Ref: 33b88560660 Ref: library/atexit atexit-exit-handlers8560660 Ref: 33b98560660 Ref: library/atexit module-atexit8560660 Ref: c8560660 Ref: library/atexit atexit register8561568 Ref: e858561568 Ref: library/atexit atexit unregister8562619 Ref: 33ba8562619 Node: atexit Example8563180 Ref: library/atexit atexit-example8563255 Ref: 33bb8563255 Ref: library/atexit id18563255 Ref: 33bc8563255 Node: traceback — Print or retrieve a stack traceback8564616 Ref: library/traceback doc8564810 Ref: 33bd8564810 Ref: library/traceback module-traceback8564810 Ref: 1138564810 Ref: library/traceback traceback-print-or-retrieve-a-stack-traceback8564810 Ref: 33be8564810 Ref: library/traceback traceback print_tb8565590 Ref: 7798565590 Ref: library/traceback traceback print_exception8566141 Ref: 1d8b8566141 Ref: library/traceback traceback print_exc8567290 Ref: 33bf8567290 Ref: library/traceback traceback print_last8567456 Ref: 33c08567456 Ref: library/traceback traceback print_stack8567783 Ref: 77a8567783 Ref: library/traceback traceback extract_tb8568328 Ref: 33c18568328 Ref: library/traceback traceback extract_stack8569069 Ref: 33c28569069 Ref: library/traceback traceback format_list8569372 Ref: 33c38569372 Ref: library/traceback traceback format_exception_only8569881 Ref: 30048569881 Ref: library/traceback traceback format_exception8570500 Ref: 33c48570500 Ref: library/traceback traceback format_exc8571109 Ref: 33c58571109 Ref: library/traceback traceback format_tb8571269 Ref: 33148571269 Ref: library/traceback traceback format_stack8571385 Ref: 33c68571385 Ref: library/traceback traceback clear_frames8571510 Ref: 8f18571510 Ref: library/traceback traceback walk_stack8571719 Ref: 7748571719 Ref: library/traceback traceback walk_tb8572029 Ref: 7758572029 Ref: traceback — Print or retrieve a stack traceback-Footnote-18572461 Node: TracebackException Objects8572529 Ref: library/traceback tracebackexception-objects8572670 Ref: 33c88572670 Ref: library/traceback traceback TracebackException8572910 Ref: 7768572910 Ref: library/traceback traceback TracebackException __cause__8573295 Ref: 33c98573295 Ref: library/traceback traceback TracebackException __context__8573403 Ref: 33ca8573403 Ref: library/traceback traceback TracebackException __suppress_context__8573525 Ref: 33cb8573525 Ref: library/traceback traceback TracebackException stack8573644 Ref: 33cc8573644 Ref: library/traceback traceback TracebackException exc_type8573737 Ref: 33cd8573737 Ref: library/traceback traceback TracebackException filename8573815 Ref: 33ce8573815 Ref: library/traceback traceback TracebackException lineno8573916 Ref: 33cf8573916 Ref: library/traceback traceback TracebackException text8574017 Ref: 33d08574017 Ref: library/traceback traceback TracebackException offset8574109 Ref: 33d18574109 Ref: library/traceback traceback TracebackException msg8574229 Ref: 33d28574229 Ref: library/traceback traceback TracebackException from_exception8574313 Ref: 33d38574313 Ref: library/traceback traceback TracebackException format8574696 Ref: 33d48574696 Ref: library/traceback traceback TracebackException format_exception_only8575244 Ref: 33d58575244 Node: StackSummary Objects8575791 Ref: library/traceback stacksummary-objects8575961 Ref: 33d68575961 Ref: library/traceback traceback StackSummary8576132 Ref: 7778576132 Ref: library/traceback traceback StackSummary extract8576167 Ref: 33c78576167 Ref: library/traceback traceback StackSummary from_list8576992 Ref: 33d78576992 Ref: library/traceback traceback StackSummary format8577295 Ref: 33d88577295 Node: FrameSummary Objects8577915 Ref: library/traceback framesummary-objects8578077 Ref: 33d98578077 Ref: library/traceback traceback FrameSummary8578244 Ref: 7788578244 Node: Traceback Examples8578989 Ref: library/traceback traceback-example8579122 Ref: 33da8579122 Ref: library/traceback traceback-examples8579122 Ref: 33db8579122 Node: __future__ — Future statement definitions8584518 Ref: library/__future__ doc8584722 Ref: 33dc8584722 Ref: library/__future__ future-future-statement-definitions8584722 Ref: 33dd8584722 Ref: library/__future__ module-__future__8584722 Ref: 08584722 Ref: __future__ — Future statement definitions-Footnote-18589927 Ref: __future__ — Future statement definitions-Footnote-28589996 Ref: __future__ — Future statement definitions-Footnote-38590045 Ref: __future__ — Future statement definitions-Footnote-48590094 Ref: __future__ — Future statement definitions-Footnote-58590143 Ref: __future__ — Future statement definitions-Footnote-68590192 Ref: __future__ — Future statement definitions-Footnote-78590241 Ref: __future__ — Future statement definitions-Footnote-88590290 Ref: __future__ — Future statement definitions-Footnote-98590339 Ref: __future__ — Future statement definitions-Footnote-108590388 Node: gc — Garbage Collector interface8590438 Ref: library/gc doc8590625 Ref: 33de8590625 Ref: library/gc gc-garbage-collector-interface8590625 Ref: 33df8590625 Ref: library/gc module-gc8590625 Ref: 868590625 Ref: library/gc gc enable8591552 Ref: 33e08591552 Ref: library/gc gc disable8591623 Ref: 33e18591623 Ref: library/gc gc isenabled8591696 Ref: 33e28591696 Ref: library/gc gc collect8591787 Ref: 22e8591787 Ref: library/gc gc set_debug8592422 Ref: 33e38592422 Ref: library/gc gc get_debug8592689 Ref: 33e48592689 Ref: library/gc gc get_objects8592768 Ref: 1cd8592768 Ref: library/gc gc get_stats8593184 Ref: 84e8593184 Ref: library/gc gc set_threshold8593878 Ref: 33e58593878 Ref: library/gc gc get_count8595104 Ref: 33e68595104 Ref: library/gc gc get_threshold8595229 Ref: 33e78595229 Ref: library/gc gc get_referrers8595374 Ref: 31f58595374 Ref: library/gc gc get_referents8596415 Ref: 31f48596415 Ref: library/gc gc is_tracked8597149 Ref: ca38597149 Ref: library/gc gc freeze8597974 Ref: 38c8597974 Ref: library/gc gc unfreeze8598508 Ref: 38d8598508 Ref: library/gc gc get_freeze_count8598667 Ref: 38e8598667 Ref: library/gc gc garbage8598910 Ref: b408598910 Ref: library/gc gc callbacks8599776 Ref: a0a8599776 Ref: library/gc gc DEBUG_STATS8601107 Ref: 33ea8601107 Ref: library/gc gc DEBUG_COLLECTABLE8601250 Ref: 33eb8601250 Ref: library/gc gc DEBUG_UNCOLLECTABLE8601336 Ref: b418601336 Ref: library/gc gc DEBUG_SAVEALL8601716 Ref: 33e98601716 Ref: library/gc gc DEBUG_LEAK8601908 Ref: 33ec8601908 Ref: gc — Garbage Collector interface-Footnote-18602152 Ref: gc — Garbage Collector interface-Footnote-28602241 Node: inspect — Inspect live objects8602290 Ref: library/inspect doc8602475 Ref: 33ed8602475 Ref: library/inspect inspect-inspect-live-objects8602475 Ref: 33ee8602475 Ref: library/inspect module-inspect8602475 Ref: a08602475 Ref: inspect — Inspect live objects-Footnote-18603647 Node: Types and members8603713 Ref: library/inspect inspect-types8603830 Ref: 33ef8603830 Ref: library/inspect types-and-members8603830 Ref: 33f08603830 Ref: library/inspect inspect getmembers8617492 Ref: 33f18617492 Ref: library/inspect inspect getmodulename8618104 Ref: 5f28618104 Ref: library/inspect inspect ismodule8618781 Ref: 33f48618781 Ref: library/inspect inspect isclass8618873 Ref: 33f58618873 Ref: library/inspect inspect ismethod8619012 Ref: 33f68619012 Ref: library/inspect inspect isfunction8619128 Ref: 33f78619128 Ref: library/inspect inspect isgeneratorfunction8619306 Ref: 33f98619306 Ref: library/inspect inspect isgenerator8619599 Ref: 33fa8619599 Ref: library/inspect inspect iscoroutinefunction8619697 Ref: 6f88619697 Ref: library/inspect inspect iscoroutine8620088 Ref: 6f78620088 Ref: library/inspect inspect isawaitable8620274 Ref: 6f98620274 Ref: library/inspect inspect isasyncgenfunction8620724 Ref: 33fb8620724 Ref: library/inspect inspect isasyncgen8621234 Ref: 33fc8621234 Ref: library/inspect inspect istraceback8621462 Ref: 33fd8621462 Ref: library/inspect inspect isframe8621560 Ref: 33fe8621560 Ref: library/inspect inspect iscode8621650 Ref: 33ff8621650 Ref: library/inspect inspect isbuiltin8621738 Ref: 34008621738 Ref: library/inspect inspect isroutine8621874 Ref: 34018621874 Ref: library/inspect inspect isabstract8622009 Ref: 34028622009 Ref: library/inspect inspect ismethoddescriptor8622117 Ref: 34038622117 Ref: library/inspect inspect isdatadescriptor8623000 Ref: 34048623000 Ref: library/inspect inspect isgetsetdescriptor8623629 Ref: 34058623629 Ref: library/inspect inspect ismemberdescriptor8623980 Ref: 34068623980 Node: Retrieving source code8624342 Ref: library/inspect inspect-source8624517 Ref: 34078624517 Ref: library/inspect retrieving-source-code8624517 Ref: 34088624517 Ref: library/inspect inspect getdoc8624584 Ref: 1d68624584 Ref: library/inspect inspect getcomments8625017 Ref: 2fc28625017 Ref: library/inspect inspect getfile8625441 Ref: 340a8625441 Ref: library/inspect inspect getmodule8625675 Ref: 340b8625675 Ref: library/inspect inspect getsourcefile8625775 Ref: 340c8625775 Ref: library/inspect inspect getsourcelines8626012 Ref: 340d8626012 Ref: library/inspect inspect getsource8626631 Ref: 340e8626631 Ref: library/inspect inspect cleandoc8627081 Ref: 34098627081 Node: Introspecting callables with the Signature object8627492 Ref: library/inspect inspect-signature-object8627674 Ref: 340f8627674 Ref: library/inspect introspecting-callables-with-the-signature-object8627674 Ref: 34108627674 Ref: library/inspect inspect signature8627991 Ref: 55b8627991 Ref: library/inspect inspect Signature8629383 Ref: 6f38629383 Ref: library/inspect inspect Signature empty8630414 Ref: 34138630414 Ref: library/inspect inspect Signature parameters8630534 Ref: 34118630534 Ref: library/inspect inspect Signature return_annotation8631029 Ref: 34148631029 Ref: library/inspect inspect Signature bind8631248 Ref: 34158631248 Ref: library/inspect inspect Signature bind_partial8631525 Ref: 34168631525 Ref: library/inspect inspect Signature replace8631901 Ref: 34128631901 Ref: library/inspect inspect Signature from_callable8632604 Ref: 6f68632604 Ref: library/inspect inspect Parameter8633186 Ref: 6f48633186 Ref: library/inspect inspect Parameter empty8633541 Ref: 34188633541 Ref: library/inspect inspect Parameter name8633672 Ref: 34198633672 Ref: library/inspect inspect Parameter default8634136 Ref: 341a8634136 Ref: library/inspect inspect Parameter annotation8634327 Ref: 341b8634327 Ref: library/inspect inspect Parameter kind8634515 Ref: 341c8634515 Ref: library/inspect inspect Parameter kind description8637339 Ref: 341d8637339 Ref: library/inspect inspect Parameter replace8637874 Ref: 34178637874 Ref: library/inspect inspect BoundArguments8638942 Ref: 9a88638942 Ref: library/inspect inspect BoundArguments arguments8639146 Ref: 341e8639146 Ref: library/inspect inspect BoundArguments args8639884 Ref: 341f8639884 Ref: library/inspect inspect BoundArguments kwargs8640036 Ref: 34208640036 Ref: library/inspect inspect BoundArguments signature8640186 Ref: 34218640186 Ref: library/inspect inspect BoundArguments apply_defaults8640284 Ref: 6f58640284 Ref: Introspecting callables with the Signature object-Footnote-18641280 Node: Classes and functions<2>8641329 Ref: library/inspect classes-and-functions8641510 Ref: 34228641510 Ref: library/inspect inspect-classes-functions8641510 Ref: 34238641510 Ref: library/inspect inspect getclasstree8641575 Ref: 34248641575 Ref: library/inspect inspect getargspec8642154 Ref: 55c8642154 Ref: library/inspect inspect getfullargspec8643091 Ref: 55d8643091 Ref: library/inspect inspect getargvalues8645465 Ref: 7b88645465 Ref: library/inspect inspect formatargspec8645970 Ref: 7b78645970 Ref: library/inspect inspect formatargvalues8647095 Ref: 7b98647095 Ref: library/inspect inspect getmro8647565 Ref: 34258647565 Ref: library/inspect inspect getcallargs8647929 Ref: 7b68647929 Ref: library/inspect inspect getclosurevars8649278 Ref: a198649278 Ref: library/inspect inspect unwrap8649994 Ref: 8698649994 Node: The interpreter stack8650728 Ref: library/inspect inspect-stack8650890 Ref: 34268650890 Ref: library/inspect the-interpreter-stack8650890 Ref: 34278650890 Ref: library/inspect inspect getframeinfo8652890 Ref: 34288652890 Ref: library/inspect inspect getouterframes8653117 Ref: 6fe8653117 Ref: library/inspect inspect getinnerframes8653613 Ref: 6ff8653613 Ref: library/inspect inspect currentframe8654106 Ref: 34298654106 Ref: library/inspect inspect stack8654507 Ref: 6fc8654507 Ref: library/inspect inspect trace8654901 Ref: 6fd8654901 Node: Fetching attributes statically8655379 Ref: library/inspect fetching-attributes-statically8655559 Ref: 342a8655559 Ref: library/inspect inspect getattr_static8656141 Ref: bcb8656141 Node: Current State of Generators and Coroutines8657946 Ref: library/inspect current-state-of-generators-and-coroutines8658127 Ref: 342b8658127 Ref: library/inspect inspect getgeneratorstate8658556 Ref: bca8658556 Ref: library/inspect inspect getcoroutinestate8658969 Ref: 6fb8658969 Ref: library/inspect inspect getgeneratorlocals8659804 Ref: a1a8659804 Ref: library/inspect inspect getcoroutinelocals8660678 Ref: 6fa8660678 Node: Code Objects Bit Flags8660913 Ref: library/inspect code-objects-bit-flags8661089 Ref: 342c8661089 Ref: library/inspect inspect-module-co-flags8661089 Ref: 33f28661089 Ref: library/inspect inspect CO_OPTIMIZED8661252 Ref: 342d8661252 Ref: library/inspect inspect CO_NEWLOCALS8661339 Ref: 342e8661339 Ref: library/inspect inspect CO_VARARGS8661484 Ref: 342f8661484 Ref: library/inspect inspect CO_VARKEYWORDS8661592 Ref: 34308661592 Ref: library/inspect inspect CO_NESTED8661704 Ref: 34318661704 Ref: library/inspect inspect CO_GENERATOR8661798 Ref: 34328661798 Ref: library/inspect inspect CO_NOFREE8661973 Ref: 34338661973 Ref: library/inspect inspect CO_COROUTINE8662064 Ref: 34348662064 Ref: library/inspect inspect CO_ITERABLE_COROUTINE8662299 Ref: 34358662299 Ref: library/inspect inspect CO_ASYNC_GENERATOR8662612 Ref: 34368662612 Ref: Code Objects Bit Flags-Footnote-18663257 Ref: Code Objects Bit Flags-Footnote-28663306 Ref: Code Objects Bit Flags-Footnote-38663355 Node: Command Line Interface<3>8663404 Ref: library/inspect command-line-interface8663529 Ref: 34378663529 Ref: library/inspect inspect-module-cli8663529 Ref: 8688663529 Ref: library/inspect cmdoption-inspect-details8663904 Ref: 34388663904 Node: site — Site-specific configuration hook8664019 Ref: library/site doc8664161 Ref: 34398664161 Ref: library/site module-site8664161 Ref: eb8664161 Ref: library/site site-site-specific-configuration-hook8664161 Ref: 343a8664161 Ref: site — Site-specific configuration hook-Footnote-18669929 Node: Readline configuration8669992 Ref: library/site readline-configuration8670119 Ref: 343c8670119 Ref: library/site rlcompleter-config8670119 Ref: 8e68670119 Node: Module contents<3>8670777 Ref: library/site module-contents8670938 Ref: 343d8670938 Ref: library/site site PREFIXES8670991 Ref: 343e8670991 Ref: library/site site ENABLE_USER_SITE8671072 Ref: 343b8671072 Ref: library/site site USER_SITE8671508 Ref: fe18671508 Ref: library/site site USER_BASE8672060 Ref: ff38672060 Ref: library/site site main8672630 Ref: fe28672630 Ref: library/site site addsitedir8672979 Ref: 343f8672979 Ref: library/site site getsitepackages8673185 Ref: bd38673185 Ref: library/site site getuserbase8673319 Ref: bd48673319 Ref: library/site site getusersitepackages8673562 Ref: bd58673562 Node: Command Line Interface<4>8673960 Ref: library/site command-line-interface8674090 Ref: 34408674090 Ref: library/site site-commandline8674090 Ref: 34418674090 Ref: library/site cmdoption-site-user-base8674636 Ref: 34428674636 Ref: library/site cmdoption-site-user-site8674718 Ref: 34438674718 Ref: Command Line Interface<4>-Footnote-18675329 Node: Custom Python Interpreters8675378 Ref: library/custominterp doc8675526 Ref: 34448675526 Ref: library/custominterp custom-python-interpreters8675526 Ref: 34458675526 Ref: library/custominterp custominterp8675526 Ref: 34468675526 Node: code — Interpreter base classes8676111 Ref: library/code doc8676246 Ref: 34478676246 Ref: library/code code-interpreter-base-classes8676246 Ref: 34488676246 Ref: library/code module-code8676246 Ref: 1b8676246 Ref: library/code code InteractiveInterpreter8676664 Ref: 34498676664 Ref: library/code code InteractiveConsole8677177 Ref: 14a98677177 Ref: library/code code interact8677487 Ref: 344a8677487 Ref: library/code code compile_command8678246 Ref: 344c8678246 Ref: code — Interpreter base classes-Footnote-18679532 Node: Interactive Interpreter Objects8679595 Ref: library/code interactive-interpreter-objects8679732 Ref: 344d8679732 Ref: library/code interpreter-objects8679732 Ref: 344e8679732 Ref: library/code code InteractiveInterpreter runsource8679815 Ref: 344f8679815 Ref: library/code code InteractiveInterpreter runcode8681102 Ref: 34518681102 Ref: library/code code InteractiveInterpreter showsyntaxerror8681561 Ref: 34508681561 Ref: library/code code InteractiveInterpreter showtraceback8682035 Ref: 6a78682035 Ref: library/code code InteractiveInterpreter write8682416 Ref: 34528682416 Node: Interactive Console Objects8682636 Ref: library/code console-objects8682773 Ref: 34538682773 Ref: library/code interactive-console-objects8682773 Ref: 34548682773 Ref: library/code code InteractiveConsole interact8683037 Ref: 34558683037 Ref: library/code code InteractiveConsole push8683890 Ref: 34568683890 Ref: library/code code InteractiveConsole resetbuffer8684585 Ref: 34578684585 Ref: library/code code InteractiveConsole raw_input8684694 Ref: 344b8684694 Node: codeop — Compile Python code8685054 Ref: library/codeop doc8685189 Ref: 34588685189 Ref: library/codeop codeop-compile-python-code8685189 Ref: 34598685189 Ref: library/codeop module-codeop8685189 Ref: 1d8685189 Ref: library/codeop codeop compile_command8686150 Ref: 345a8686150 Ref: library/codeop codeop Compile8687552 Ref: 345b8687552 Ref: library/codeop codeop CommandCompiler8687953 Ref: 345c8687953 Ref: codeop — Compile Python code-Footnote-18688371 Node: Importing Modules8688436 Ref: library/modules doc8688585 Ref: 345d8688585 Ref: library/modules importing-modules8688585 Ref: 345e8688585 Ref: library/modules modules8688585 Ref: 345f8688585 Node: zipimport — Import modules from Zip archives8689128 Ref: library/zipimport doc8689274 Ref: 34608689274 Ref: library/zipimport module-zipimport8689274 Ref: 1438689274 Ref: library/zipimport zipimport-import-modules-from-zip-archives8689274 Ref: 34618689274 Ref: library/zipimport zipimport ZipImportError8691377 Ref: 34628691377 Ref: zipimport — Import modules from Zip archives-Footnote-18691669 Ref: zipimport — Import modules from Zip archives-Footnote-28691737 Ref: zipimport — Import modules from Zip archives-Footnote-38691805 Ref: zipimport — Import modules from Zip archives-Footnote-48691854 Ref: zipimport — Import modules from Zip archives-Footnote-58691903 Ref: zipimport — Import modules from Zip archives-Footnote-68691952 Node: zipimporter Objects8692001 Ref: library/zipimport id18692124 Ref: 34638692124 Ref: library/zipimport zipimporter-objects8692124 Ref: 34648692124 Ref: library/zipimport zipimport zipimporter8692247 Ref: 34658692247 Ref: library/zipimport zipimport zipimporter find_module8692718 Ref: 34668692718 Ref: library/zipimport zipimport zipimporter get_code8693142 Ref: 34678693142 Ref: library/zipimport zipimport zipimporter get_data8693320 Ref: 34688693320 Ref: library/zipimport zipimport zipimporter get_filename8693592 Ref: 34698693592 Ref: library/zipimport zipimport zipimporter get_source8693852 Ref: 346a8693852 Ref: library/zipimport zipimport zipimporter is_package8694142 Ref: 346b8694142 Ref: library/zipimport zipimport zipimporter load_module8694353 Ref: 346c8694353 Ref: library/zipimport zipimport zipimporter archive8694631 Ref: 346d8694631 Ref: library/zipimport zipimport zipimporter prefix8694764 Ref: 346e8694764 Node: Examples<28>8695171 Ref: library/zipimport examples8695294 Ref: 346f8695294 Ref: library/zipimport zipimport-examples8695294 Ref: 34708695294 Node: pkgutil — Package extension utility8695974 Ref: library/pkgutil doc8696175 Ref: 34718696175 Ref: library/pkgutil module-pkgutil8696175 Ref: cd8696175 Ref: library/pkgutil pkgutil-package-extension-utility8696175 Ref: 34728696175 Ref: library/pkgutil pkgutil ModuleInfo8696460 Ref: 60d8696460 Ref: library/pkgutil pkgutil extend_path8696614 Ref: 34738696614 Ref: library/pkgutil pkgutil ImpImporter8698286 Ref: 34748698286 Ref: library/pkgutil pkgutil ImpLoader8698985 Ref: 34758698985 Ref: library/pkgutil pkgutil find_loader8699314 Ref: 34768699314 Ref: library/pkgutil pkgutil get_importer8699891 Ref: 34778699891 Ref: library/pkgutil pkgutil get_loader8700406 Ref: 34788700406 Ref: library/pkgutil pkgutil iter_importers8701123 Ref: b148701123 Ref: library/pkgutil pkgutil iter_modules8701822 Ref: 60c8701822 Ref: library/pkgutil pkgutil walk_packages8702668 Ref: 48b8702668 Ref: library/pkgutil pkgutil get_data8704246 Ref: 34798704246 Ref: pkgutil — Package extension utility-Footnote-18705416 Ref: pkgutil — Package extension utility-Footnote-28705482 Ref: pkgutil — Package extension utility-Footnote-38705531 Ref: pkgutil — Package extension utility-Footnote-48705580 Ref: pkgutil — Package extension utility-Footnote-58705629 Ref: pkgutil — Package extension utility-Footnote-68705678 Ref: pkgutil — Package extension utility-Footnote-78705727 Ref: pkgutil — Package extension utility-Footnote-88705776 Ref: pkgutil — Package extension utility-Footnote-98705825 Ref: pkgutil — Package extension utility-Footnote-108705874 Ref: pkgutil — Package extension utility-Footnote-118705924 Ref: pkgutil — Package extension utility-Footnote-128705974 Ref: pkgutil — Package extension utility-Footnote-138706024 Ref: pkgutil — Package extension utility-Footnote-148706074 Node: modulefinder — Find modules used by a script8706124 Ref: library/modulefinder doc8706326 Ref: 347b8706326 Ref: library/modulefinder module-modulefinder8706326 Ref: b48706326 Ref: library/modulefinder modulefinder-find-modules-used-by-a-script8706326 Ref: 347c8706326 Ref: library/modulefinder modulefinder AddPackagePath8706845 Ref: 347e8706845 Ref: library/modulefinder modulefinder ReplacePackage8706995 Ref: 347f8706995 Ref: library/modulefinder modulefinder ModuleFinder8707158 Ref: 347d8707158 Ref: library/modulefinder modulefinder ModuleFinder report8707817 Ref: 34818707817 Ref: library/modulefinder modulefinder ModuleFinder run_script8708032 Ref: 34808708032 Ref: library/modulefinder modulefinder ModuleFinder modules8708170 Ref: 34828708170 Ref: modulefinder — Find modules used by a script-Footnote-18708394 Node: Example usage of ModuleFinder8708465 Ref: library/modulefinder example-usage-of-modulefinder8708577 Ref: 34848708577 Ref: library/modulefinder modulefinder-example8708577 Ref: 34838708577 Node: runpy — Locating and executing Python modules8709948 Ref: library/runpy doc8710155 Ref: 34858710155 Ref: library/runpy module-runpy8710155 Ref: e28710155 Ref: library/runpy runpy-locating-and-executing-python-modules8710155 Ref: 34868710155 Ref: library/runpy runpy run_module8711190 Ref: fd38711190 Ref: library/runpy runpy run_path8714452 Ref: cb18714452 Ref: runpy — Locating and executing Python modules-Footnote-18718737 Ref: runpy — Locating and executing Python modules-Footnote-28718801 Ref: runpy — Locating and executing Python modules-Footnote-38718850 Ref: runpy — Locating and executing Python modules-Footnote-48718899 Ref: runpy — Locating and executing Python modules-Footnote-58718948 Ref: runpy — Locating and executing Python modules-Footnote-68718997 Ref: runpy — Locating and executing Python modules-Footnote-78719046 Ref: runpy — Locating and executing Python modules-Footnote-88719095 Node: importlib — The implementation of import8719144 Ref: library/importlib doc8719329 Ref: 34878719329 Ref: library/importlib importlib-the-implementation-of-import8719329 Ref: 34888719329 Ref: library/importlib module-importlib8719329 Ref: 9b8719329 Ref: importlib — The implementation of import-Footnote-18720102 Node: Introduction<12>8720180 Ref: library/importlib introduction8720297 Ref: 34898720297 Ref: Introduction<12>-Footnote-18722132 Ref: Introduction<12>-Footnote-28722184 Ref: Introduction<12>-Footnote-38722233 Ref: Introduction<12>-Footnote-48722282 Ref: Introduction<12>-Footnote-58722331 Ref: Introduction<12>-Footnote-68722380 Ref: Introduction<12>-Footnote-78722429 Ref: Introduction<12>-Footnote-88722478 Ref: Introduction<12>-Footnote-98722527 Ref: Introduction<12>-Footnote-108722576 Ref: Introduction<12>-Footnote-118722626 Ref: Introduction<12>-Footnote-128722676 Ref: Introduction<12>-Footnote-138722726 Node: Functions<10>8722776 Ref: library/importlib functions8722959 Ref: 348a8722959 Ref: library/importlib importlib __import__8722998 Ref: 9ae8722998 Ref: library/importlib importlib import_module8723306 Ref: b138723306 Ref: library/importlib importlib find_loader8724634 Ref: 9378724634 Ref: library/importlib importlib invalidate_caches8725638 Ref: 49c8725638 Ref: library/importlib importlib reload8726087 Ref: 3998726087 Node: importlib abc – Abstract base classes related to import8729319 Ref: library/importlib importlib-abc-abstract-base-classes-related-to-import8729519 Ref: 348b8729519 Ref: library/importlib module-importlib abc8729519 Ref: 9c8729519 Ref: library/importlib importlib abc Finder8730352 Ref: 9b58730352 Ref: library/importlib importlib abc Finder find_module8730561 Ref: 348c8730561 Ref: library/importlib importlib abc MetaPathFinder8731011 Ref: 9b38731011 Ref: library/importlib importlib abc MetaPathFinder find_spec8731216 Ref: 4638731216 Ref: library/importlib importlib abc MetaPathFinder find_module8731969 Ref: 4628731969 Ref: library/importlib importlib abc MetaPathFinder invalidate_caches8732792 Ref: 348e8732792 Ref: library/importlib importlib abc PathEntryFinder8733201 Ref: 9b48733201 Ref: library/importlib importlib abc PathEntryFinder find_spec8733618 Ref: 4658733618 Ref: library/importlib importlib abc PathEntryFinder find_loader8734256 Ref: 4648734256 Ref: library/importlib importlib abc PathEntryFinder find_module8735459 Ref: 93b8735459 Ref: library/importlib importlib abc PathEntryFinder invalidate_caches8735732 Ref: 348f8735732 Ref: library/importlib importlib abc Loader8736006 Ref: 7c28736006 Ref: library/importlib importlib abc Loader create_module8736430 Ref: 5548736430 Ref: library/importlib importlib abc Loader exec_module8736863 Ref: 5e48736863 Ref: library/importlib importlib abc Loader load_module8737331 Ref: 5e38737331 Ref: library/importlib importlib abc Loader module_repr8740504 Ref: 9418740504 Ref: library/importlib importlib abc ResourceReader8741003 Ref: 3428741003 Ref: library/importlib importlib abc ResourceReader open_resource8742661 Ref: 34908742661 Ref: library/importlib importlib abc ResourceReader resource_path8742922 Ref: 34918742922 Ref: library/importlib importlib abc ResourceReader is_resource8743158 Ref: 34928743158 Ref: library/importlib importlib abc ResourceReader contents8743372 Ref: 34938743372 Ref: library/importlib importlib abc ResourceLoader8744240 Ref: 4668744240 Ref: library/importlib importlib abc ResourceLoader get_data8744614 Ref: 347a8744614 Ref: library/importlib importlib abc InspectLoader8745301 Ref: 8608745301 Ref: library/importlib importlib abc InspectLoader get_code8745485 Ref: 8618745485 Ref: library/importlib importlib abc InspectLoader get_source8746068 Ref: 8658746068 Ref: library/importlib importlib abc InspectLoader is_package8746650 Ref: 34948746650 Ref: library/importlib importlib abc InspectLoader source_to_code8747021 Ref: 6ef8747021 Ref: library/importlib importlib abc InspectLoader exec_module8747665 Ref: 93f8747665 Ref: library/importlib importlib abc InspectLoader load_module8747797 Ref: 93c8747797 Ref: library/importlib importlib abc ExecutionLoader8747990 Ref: 34958747990 Ref: library/importlib importlib abc ExecutionLoader get_filename8748237 Ref: 34968748237 Ref: library/importlib importlib abc FileLoader8748784 Ref: 9b78748784 Ref: library/importlib importlib abc FileLoader name8749278 Ref: 34978749278 Ref: library/importlib importlib abc FileLoader path8749361 Ref: 34988749361 Ref: library/importlib importlib abc FileLoader load_module8749430 Ref: 93d8749430 Ref: library/importlib importlib abc FileLoader get_filename8749616 Ref: 34998749616 Ref: library/importlib importlib abc FileLoader get_data8749710 Ref: 349a8749710 Ref: library/importlib importlib abc SourceLoader8749831 Ref: 349b8749831 Ref: library/importlib importlib abc SourceLoader path_stats8750928 Ref: aec8750928 Ref: library/importlib importlib abc SourceLoader path_mtime8751706 Ref: aeb8751706 Ref: library/importlib importlib abc SourceLoader set_data8752254 Ref: 349c8752254 Ref: library/importlib importlib abc SourceLoader get_code8752769 Ref: 349d8752769 Ref: library/importlib importlib abc SourceLoader exec_module8752892 Ref: 9408752892 Ref: library/importlib importlib abc SourceLoader load_module8753033 Ref: 93e8753033 Ref: library/importlib importlib abc SourceLoader get_source8753235 Ref: 9598753235 Ref: library/importlib importlib abc SourceLoader is_package8753362 Ref: 349e8753362 Ref: importlib abc – Abstract base classes related to import-Footnote-18753801 Ref: importlib abc – Abstract base classes related to import-Footnote-28753873 Ref: importlib abc – Abstract base classes related to import-Footnote-38753922 Ref: importlib abc – Abstract base classes related to import-Footnote-48753971 Ref: importlib abc – Abstract base classes related to import-Footnote-58754020 Ref: importlib abc – Abstract base classes related to import-Footnote-68754069 Node: importlib resources – Resources8754118 Ref: library/importlib importlib-resources-resources8754353 Ref: 349f8754353 Ref: library/importlib module-importlib resources8754353 Ref: 9e8754353 Ref: library/importlib importlib resources Package8755690 Ref: 34a08755690 Ref: library/importlib importlib resources Resource8756045 Ref: 34a18756045 Ref: library/importlib importlib resources open_binary8756282 Ref: 34a28756282 Ref: library/importlib importlib resources open_text8756803 Ref: 34a38756803 Ref: library/importlib importlib resources read_binary8757516 Ref: 34a48757516 Ref: library/importlib importlib resources read_text8758038 Ref: 34a58758038 Ref: library/importlib importlib resources path8758741 Ref: 34a68758741 Ref: library/importlib importlib resources is_resource8759458 Ref: 34a78759458 Ref: library/importlib importlib resources contents8759779 Ref: 34a88759779 Ref: importlib resources – Resources-Footnote-18760210 Ref: importlib resources – Resources-Footnote-28760289 Ref: importlib resources – Resources-Footnote-38760360 Ref: importlib resources – Resources-Footnote-48760453 Ref: importlib resources – Resources-Footnote-58760524 Node: importlib machinery – Importers and path hooks8760600 Ref: library/importlib importlib-machinery-importers-and-path-hooks8760823 Ref: 34a98760823 Ref: library/importlib module-importlib machinery8760823 Ref: 9d8760823 Ref: library/importlib importlib machinery SOURCE_SUFFIXES8761154 Ref: 34aa8761154 Ref: library/importlib importlib machinery DEBUG_BYTECODE_SUFFIXES8761323 Ref: 34ab8761323 Ref: library/importlib importlib machinery OPTIMIZED_BYTECODE_SUFFIXES8761590 Ref: 34ad8761590 Ref: library/importlib importlib machinery BYTECODE_SUFFIXES8761857 Ref: 34ac8761857 Ref: library/importlib importlib machinery EXTENSION_SUFFIXES8762146 Ref: 34ae8762146 Ref: library/importlib importlib machinery all_suffixes8762321 Ref: 33f38762321 Ref: library/importlib importlib machinery BuiltinImporter8762755 Ref: 5558762755 Ref: library/importlib importlib machinery FrozenImporter8763320 Ref: 9578763320 Ref: library/importlib importlib machinery WindowsRegistryFinder8763740 Ref: 5e58763740 Ref: library/importlib importlib machinery PathFinder8764226 Ref: 95b8764226 Ref: library/importlib importlib machinery PathFinder find_spec8764541 Ref: 93a8764541 Ref: library/importlib importlib machinery PathFinder find_module8765718 Ref: 9398765718 Ref: library/importlib importlib machinery PathFinder invalidate_caches8765929 Ref: 49b8765929 Ref: library/importlib importlib machinery FileFinder8766541 Ref: 9b68766541 Ref: library/importlib importlib machinery FileFinder path8767846 Ref: 34af8767846 Ref: library/importlib importlib machinery FileFinder find_spec8767919 Ref: 7c18767919 Ref: library/importlib importlib machinery FileFinder find_loader8768094 Ref: 34b08768094 Ref: library/importlib importlib machinery FileFinder invalidate_caches8768229 Ref: 34b18768229 Ref: library/importlib importlib machinery FileFinder path_hook8768309 Ref: 34b28768309 Ref: library/importlib importlib machinery SourceFileLoader8768755 Ref: 9b88768755 Ref: library/importlib importlib machinery SourceFileLoader name8769046 Ref: 34b38769046 Ref: library/importlib importlib machinery SourceFileLoader path8769136 Ref: 34b48769136 Ref: library/importlib importlib machinery SourceFileLoader is_package8769202 Ref: 34b58769202 Ref: library/importlib importlib machinery SourceFileLoader path_stats8769331 Ref: 34b68769331 Ref: library/importlib importlib machinery SourceFileLoader set_data8769467 Ref: 34b78769467 Ref: library/importlib importlib machinery SourceFileLoader load_module8769606 Ref: 5e18769606 Ref: library/importlib importlib machinery SourcelessFileLoader8769925 Ref: 9b98769925 Ref: library/importlib importlib machinery SourcelessFileLoader name8770396 Ref: 34b88770396 Ref: library/importlib importlib machinery SourcelessFileLoader path8770480 Ref: 34b98770480 Ref: library/importlib importlib machinery SourcelessFileLoader is_package8770548 Ref: 34ba8770548 Ref: library/importlib importlib machinery SourcelessFileLoader get_code8770674 Ref: 34bb8770674 Ref: library/importlib importlib machinery SourcelessFileLoader get_source8770810 Ref: 34bc8770810 Ref: library/importlib importlib machinery SourcelessFileLoader load_module8770949 Ref: 5e28770949 Ref: library/importlib importlib machinery ExtensionFileLoader8771243 Ref: 5568771243 Ref: library/importlib importlib machinery ExtensionFileLoader name8771610 Ref: 34bd8771610 Ref: library/importlib importlib machinery ExtensionFileLoader path8771687 Ref: 34be8771687 Ref: library/importlib importlib machinery ExtensionFileLoader create_module8771754 Ref: 34bf8771754 Ref: library/importlib importlib machinery ExtensionFileLoader exec_module8771931 Ref: 34c08771931 Ref: library/importlib importlib machinery ExtensionFileLoader is_package8772089 Ref: 34c18772089 Ref: library/importlib importlib machinery ExtensionFileLoader get_code8772273 Ref: 34c28772273 Ref: library/importlib importlib machinery ExtensionFileLoader get_source8772382 Ref: 34c38772382 Ref: library/importlib importlib machinery ExtensionFileLoader get_filename8772498 Ref: 8668772498 Ref: library/importlib importlib machinery ModuleSpec8772608 Ref: 116b8772608 Ref: library/importlib importlib machinery ModuleSpec name8773421 Ref: 16648773421 Ref: library/importlib importlib machinery ModuleSpec loader8773529 Ref: 16628773529 Ref: library/importlib importlib machinery ModuleSpec origin8773708 Ref: 34c48773708 Ref: library/importlib importlib machinery ModuleSpec submodule_search_locations8774069 Ref: 34c58774069 Ref: library/importlib importlib machinery ModuleSpec loader_state8774234 Ref: 34c68774234 Ref: library/importlib importlib machinery ModuleSpec cached8774359 Ref: 34c78774359 Ref: library/importlib importlib machinery ModuleSpec parent8774489 Ref: 16668774489 Ref: library/importlib importlib machinery ModuleSpec has_location8774770 Ref: 34c88774770 Ref: importlib machinery – Importers and path hooks-Footnote-18774954 Ref: importlib machinery – Importers and path hooks-Footnote-28775033 Ref: importlib machinery – Importers and path hooks-Footnote-38775082 Ref: importlib machinery – Importers and path hooks-Footnote-48775131 Node: importlib util – Utility code for importers8775180 Ref: library/importlib importlib-util-utility-code-for-importers8775382 Ref: 34c98775382 Ref: library/importlib module-importlib util8775382 Ref: 9f8775382 Ref: library/importlib importlib util MAGIC_NUMBER8775708 Ref: 8628775708 Ref: library/importlib importlib util cache_from_source8775951 Ref: 5578775951 Ref: library/importlib importlib util source_from_cache8777860 Ref: 5588777860 Ref: library/importlib importlib util decode_source8778485 Ref: 8648778485 Ref: library/importlib importlib util resolve_name8778755 Ref: 34ca8778755 Ref: library/importlib importlib util find_spec8779459 Ref: 9388779459 Ref: library/importlib importlib util module_from_spec8780351 Ref: 6f08780351 Ref: library/importlib importlib util module_for_loader8780984 Ref: 9428780984 Ref: library/importlib importlib util set_loader8782761 Ref: 9438782761 Ref: library/importlib importlib util set_package8783387 Ref: 9448783387 Ref: library/importlib importlib util spec_from_loader8783793 Ref: 348d8783793 Ref: library/importlib importlib util spec_from_file_location8784239 Ref: 5598784239 Ref: library/importlib importlib util source_hash8784713 Ref: 34cb8784713 Ref: library/importlib importlib util LazyLoader8784985 Ref: 5538784985 Ref: library/importlib importlib util LazyLoader factory8786468 Ref: 34cd8786468 Ref: importlib util – Utility code for importers-Footnote-18787032 Ref: importlib util – Utility code for importers-Footnote-28787105 Ref: importlib util – Utility code for importers-Footnote-38787154 Ref: importlib util – Utility code for importers-Footnote-48787203 Ref: importlib util – Utility code for importers-Footnote-58787252 Ref: importlib util – Utility code for importers-Footnote-68787301 Node: Examples<29>8787350 Ref: library/importlib examples8787495 Ref: 34ce8787495 Ref: library/importlib importlib-examples8787495 Ref: 34cf8787495 Node: Importing programmatically8787760 Ref: library/importlib importing-programmatically8787880 Ref: 34d08787880 Node: Checking if a module can be imported8788111 Ref: library/importlib checking-if-a-module-can-be-imported8788272 Ref: 34d18788272 Node: Importing a source file directly8789057 Ref: library/importlib importing-a-source-file-directly8789214 Ref: 34d28789214 Node: Setting up an importer8789773 Ref: library/importlib setting-up-an-importer8789931 Ref: 34d38789931 Node: Approximating importlib import_module8791505 Ref: library/importlib approximating-importlib-import-module8791622 Ref: 34d48791622 Node: Using importlib metadata8793219 Ref: library/importlib metadata doc8793348 Ref: 34d58793348 Ref: library/importlib metadata using8793348 Ref: 34d68793348 Ref: library/importlib metadata using-importlib-metadata8793348 Ref: 34d78793348 Ref: Using importlib metadata-Footnote-18794691 Ref: Using importlib metadata-Footnote-28794776 Ref: Using importlib metadata-Footnote-38794861 Ref: Using importlib metadata-Footnote-48794933 Ref: Using importlib metadata-Footnote-58794971 Node: Overview<2>8795020 Ref: library/importlib metadata overview8795118 Ref: 34d88795118 Node: Functional API<2>8796540 Ref: library/importlib metadata functional-api8796660 Ref: 34de8796660 Node: Entry points8796912 Ref: library/importlib metadata entry-points8797008 Ref: 34d98797008 Ref: library/importlib metadata id18797008 Ref: 34df8797008 Ref: Entry points-Footnote-18798088 Node: Distribution metadata8798199 Ref: library/importlib metadata distribution-metadata8798325 Ref: 34e08798325 Ref: library/importlib metadata metadata8798325 Ref: 34da8798325 Ref: Distribution metadata-Footnote-18798809 Node: Distribution versions8799089 Ref: library/importlib metadata distribution-versions8799221 Ref: 34e18799221 Ref: library/importlib metadata version8799221 Ref: 34db8799221 Node: Distribution files8799430 Ref: library/importlib metadata distribution-files8799566 Ref: 34e28799566 Ref: library/importlib metadata files8799566 Ref: 34dc8799566 Ref: Distribution files-Footnote-18800956 Node: Distribution requirements8801053 Ref: library/importlib metadata distribution-requirements8801159 Ref: 34e38801159 Ref: library/importlib metadata requirements8801159 Ref: 34dd8801159 Node: Distributions8801426 Ref: library/importlib metadata distributions8801565 Ref: 34e48801565 Ref: Distributions-Footnote-18802472 Node: Extending the search algorithm8802521 Ref: library/importlib metadata extending-the-search-algorithm8802634 Ref: 34e58802634 Node: Python Language Services8804401 Ref: library/language doc8804546 Ref: 34e68804546 Ref: library/language language8804546 Ref: 34e78804546 Ref: library/language python-language-services8804546 Ref: 34e88804546 Node: parser — Access Python parse trees8805453 Ref: library/parser doc8805588 Ref: 34e98805588 Ref: library/parser module-parser8805588 Ref: c78805588 Ref: library/parser parser-access-python-parse-trees8805588 Ref: 34ea8805588 Node: Creating ST Objects8810798 Ref: library/parser creating-st-objects8810920 Ref: 34f08810920 Ref: library/parser creating-sts8810920 Ref: 34f18810920 Ref: library/parser parser expr8811166 Ref: 34eb8811166 Ref: library/parser parser suite8811501 Ref: 34ec8811501 Ref: library/parser parser sequence2st8811838 Ref: 34ed8811838 Ref: library/parser parser tuple2st8813253 Ref: 34f48813253 Node: Converting ST Objects8813422 Ref: library/parser converting-st-objects8813574 Ref: 34f58813574 Ref: library/parser converting-sts8813574 Ref: 34f68813574 Ref: library/parser parser st2list8813888 Ref: 34ee8813888 Ref: library/parser parser st2tuple8814962 Ref: 34ef8814962 Ref: library/parser parser compilest8815506 Ref: 34f38815506 Node: Queries on ST Objects8816669 Ref: library/parser queries-on-st-objects8816831 Ref: 34f78816831 Ref: library/parser querying-sts8816831 Ref: 34f88816831 Ref: library/parser parser isexpr8817203 Ref: 34f98817203 Ref: library/parser parser issuite8817686 Ref: 34fa8817686 Node: Exceptions and Error Handling8818046 Ref: library/parser exceptions-and-error-handling8818197 Ref: 34fb8818197 Ref: library/parser st-errors8818197 Ref: 34fc8818197 Ref: library/parser parser ParserError8818492 Ref: 34f28818492 Node: ST Objects8819654 Ref: library/parser id18819812 Ref: 34fd8819812 Ref: library/parser st-objects8819812 Ref: 34fe8819812 Ref: library/parser parser STType8820000 Ref: 34ff8820000 Ref: library/parser parser ST compile8820184 Ref: 35008820184 Ref: library/parser parser ST isexpr8820280 Ref: 35018820280 Ref: library/parser parser ST issuite8820338 Ref: 35028820338 Ref: library/parser parser ST tolist8820398 Ref: 35038820398 Ref: library/parser parser ST totuple8820509 Ref: 35048820509 Node: Example Emulation of compile8820622 Ref: library/parser example-emulation-of-compile8820742 Ref: 35058820742 Node: ast — Abstract Syntax Trees8821836 Ref: library/ast doc8822033 Ref: 35068822033 Ref: library/ast ast-abstract-syntax-trees8822033 Ref: 35078822033 Ref: library/ast module-ast8822033 Ref: 88822033 Ref: ast — Abstract Syntax Trees-Footnote-18822978 Node: Node classes8823040 Ref: library/ast node-classes8823143 Ref: 35098823143 Ref: library/ast ast AST8823188 Ref: 35088823188 Ref: library/ast ast AST _fields8824011 Ref: 350b8824011 Ref: library/ast ast AST lineno8824813 Ref: 350c8824813 Ref: library/ast ast AST col_offset8824840 Ref: 350d8824840 Ref: library/ast ast AST end_lineno8824871 Ref: 350e8824871 Ref: library/ast ast AST end_col_offset8824902 Ref: 350f8824902 Node: Abstract Grammar8827173 Ref: library/ast abstract-grammar8827296 Ref: 350a8827296 Ref: library/ast id18827296 Ref: 35108827296 Node: ast Helpers8833351 Ref: library/ast ast-helpers8833453 Ref: 35118833453 Ref: library/ast ast parse8833641 Ref: 1a18833641 Ref: library/ast ast literal_eval8835442 Ref: 4a58835442 Ref: library/ast ast get_docstring8836303 Ref: 35128836303 Ref: library/ast ast get_source_segment8836722 Ref: 1a08836722 Ref: library/ast ast fix_missing_locations8837172 Ref: 35138837172 Ref: library/ast ast increment_lineno8837628 Ref: 35148837628 Ref: library/ast ast copy_location8837860 Ref: 35158837860 Ref: library/ast ast iter_fields8838094 Ref: 35168838094 Ref: library/ast ast iter_child_nodes8838249 Ref: 35178838249 Ref: library/ast ast walk8838427 Ref: 35188838427 Ref: library/ast ast NodeVisitor8838693 Ref: 2818838693 Ref: library/ast ast NodeVisitor visit8839035 Ref: 35198839035 Ref: library/ast ast NodeVisitor generic_visit8839315 Ref: 351a8839315 Ref: library/ast ast NodeTransformer8840150 Ref: 351b8840150 Ref: library/ast ast dump8842021 Ref: 351c8842021 Ref: ast Helpers-Footnote-18843489 Ref: ast Helpers-Footnote-28843538 Ref: ast Helpers-Footnote-38843587 Ref: ast Helpers-Footnote-48843636 Ref: ast Helpers-Footnote-58843684 Ref: ast Helpers-Footnote-68843751 Ref: ast Helpers-Footnote-78843806 Ref: ast Helpers-Footnote-88843845 Node: symtable — Access to the compiler’s symbol tables8843882 Ref: library/symtable doc8844092 Ref: 351d8844092 Ref: library/symtable module-symtable8844092 Ref: fc8844092 Ref: library/symtable symtable-access-to-the-compiler-s-symbol-tables8844092 Ref: 351e8844092 Ref: symtable — Access to the compiler’s symbol tables-Footnote-18844674 Node: Generating Symbol Tables8844741 Ref: library/symtable generating-symbol-tables8844887 Ref: 351f8844887 Ref: library/symtable symtable symtable8844956 Ref: 35208844956 Node: Examining Symbol Tables8845236 Ref: library/symtable examining-symbol-tables8845382 Ref: 35228845382 Ref: library/symtable symtable SymbolTable8845449 Ref: 35218845449 Ref: library/symtable symtable SymbolTable get_type8845551 Ref: 35238845551 Ref: library/symtable symtable SymbolTable get_id8845713 Ref: 35248845713 Ref: library/symtable symtable SymbolTable get_name8845785 Ref: 35258845785 Ref: library/symtable symtable SymbolTable get_lineno8846088 Ref: 35268846088 Ref: library/symtable symtable SymbolTable is_optimized8846213 Ref: 35278846213 Ref: library/symtable symtable SymbolTable is_nested8846322 Ref: 35288846322 Ref: library/symtable symtable SymbolTable has_children8846426 Ref: 35298846426 Ref: library/symtable symtable SymbolTable has_exec8846600 Ref: 352b8846600 Ref: library/symtable symtable SymbolTable get_identifiers8846689 Ref: 352c8846689 Ref: library/symtable symtable SymbolTable lookup8846786 Ref: 352d8846786 Ref: library/symtable symtable SymbolTable get_symbols8846909 Ref: 352f8846909 Ref: library/symtable symtable SymbolTable get_children8847034 Ref: 352a8847034 Ref: library/symtable symtable Function8847122 Ref: 35308847122 Ref: library/symtable symtable Function get_parameters8847247 Ref: 35318847247 Ref: library/symtable symtable Function get_locals8847368 Ref: 35328847368 Ref: library/symtable symtable Function get_globals8847471 Ref: 35338847471 Ref: library/symtable symtable Function get_nonlocals8847576 Ref: 35348847576 Ref: library/symtable symtable Function get_frees8847685 Ref: 35358847685 Ref: library/symtable symtable Class8847805 Ref: 35368847805 Ref: library/symtable symtable Class get_methods8847913 Ref: 35378847913 Ref: library/symtable symtable Symbol8848037 Ref: 352e8848037 Ref: library/symtable symtable Symbol get_name8848193 Ref: 35388848193 Ref: library/symtable symtable Symbol is_referenced8848262 Ref: 35398848262 Ref: library/symtable symtable Symbol is_imported8848362 Ref: 353a8848362 Ref: library/symtable symtable Symbol is_parameter8848485 Ref: 353b8848485 Ref: library/symtable symtable Symbol is_global8848578 Ref: 353c8848578 Ref: library/symtable symtable Symbol is_nonlocal8848663 Ref: 353d8848663 Ref: library/symtable symtable Symbol is_declared_global8848752 Ref: cb68848752 Ref: library/symtable symtable Symbol is_local8848889 Ref: 353e8848889 Ref: library/symtable symtable Symbol is_annotated8848985 Ref: 353f8848985 Ref: library/symtable symtable Symbol is_free8849107 Ref: 35408849107 Ref: library/symtable symtable Symbol is_assigned8849238 Ref: 35418849238 Ref: library/symtable symtable Symbol is_namespace8849343 Ref: 35428849343 Ref: library/symtable symtable Symbol get_namespaces8849985 Ref: 35438849985 Ref: library/symtable symtable Symbol get_namespace8850080 Ref: 35448850080 Node: symbol — Constants used with Python parse trees8850249 Ref: library/symbol doc8850478 Ref: 35458850478 Ref: library/symbol module-symbol8850478 Ref: fb8850478 Ref: library/symbol symbol-constants-used-with-python-parse-trees8850478 Ref: 35468850478 Ref: library/symbol symbol sym_name8851147 Ref: 35478851147 Ref: symbol — Constants used with Python parse trees-Footnote-18851402 Node: token — Constants used with Python parse trees8851467 Ref: library/token doc8851682 Ref: 35488851682 Ref: library/token module-token8851682 Ref: 1108851682 Ref: library/token token-constants-used-with-python-parse-trees8851682 Ref: 35498851682 Ref: library/token token tok_name8852396 Ref: 354a8852396 Ref: library/token token ISTERMINAL8852614 Ref: 354b8852614 Ref: library/token token ISNONTERMINAL8852701 Ref: 354c8852701 Ref: library/token token ISEOF8852795 Ref: 354d8852795 Ref: library/token token ENDMARKER8852926 Ref: 354e8852926 Ref: library/token token NAME8852953 Ref: 354f8852953 Ref: library/token token NUMBER8852975 Ref: 35508852975 Ref: library/token token STRING8852999 Ref: 35518852999 Ref: library/token token NEWLINE8853023 Ref: 35528853023 Ref: library/token token INDENT8853048 Ref: 35538853048 Ref: library/token token DEDENT8853072 Ref: 35548853072 Ref: library/token token LPAR8853096 Ref: 35558853096 Ref: library/token token RPAR8853151 Ref: 35568853151 Ref: library/token token LSQB8853206 Ref: 35578853206 Ref: library/token token RSQB8853261 Ref: 35588853261 Ref: library/token token COLON8853316 Ref: 35598853316 Ref: library/token token COMMA8853372 Ref: 355a8853372 Ref: library/token token SEMI8853428 Ref: 355b8853428 Ref: library/token token PLUS8853483 Ref: 355c8853483 Ref: library/token token MINUS8853538 Ref: 355d8853538 Ref: library/token token STAR8853594 Ref: 355e8853594 Ref: library/token token SLASH8853649 Ref: 355f8853649 Ref: library/token token VBAR8853705 Ref: 35608853705 Ref: library/token token AMPER8853760 Ref: 35618853760 Ref: library/token token LESS8853816 Ref: 35628853816 Ref: library/token token GREATER8853871 Ref: 35638853871 Ref: library/token token EQUAL8853929 Ref: 35648853929 Ref: library/token token DOT8853985 Ref: 35658853985 Ref: library/token token PERCENT8854039 Ref: 35668854039 Ref: library/token token LBRACE8854097 Ref: 35678854097 Ref: library/token token RBRACE8854154 Ref: 35688854154 Ref: library/token token EQEQUAL8854211 Ref: 35698854211 Ref: library/token token NOTEQUAL8854270 Ref: 356a8854270 Ref: library/token token LESSEQUAL8854330 Ref: 356b8854330 Ref: library/token token GREATEREQUAL8854391 Ref: 356c8854391 Ref: library/token token TILDE8854455 Ref: 356d8854455 Ref: library/token token CIRCUMFLEX8854511 Ref: 356e8854511 Ref: library/token token LEFTSHIFT8854572 Ref: 356f8854572 Ref: library/token token RIGHTSHIFT8854633 Ref: 35708854633 Ref: library/token token DOUBLESTAR8854695 Ref: 35718854695 Ref: library/token token PLUSEQUAL8854757 Ref: 35728854757 Ref: library/token token MINEQUAL8854818 Ref: 35738854818 Ref: library/token token STAREQUAL8854878 Ref: 35748854878 Ref: library/token token SLASHEQUAL8854939 Ref: 35758854939 Ref: library/token token PERCENTEQUAL8855001 Ref: 35768855001 Ref: library/token token AMPEREQUAL8855065 Ref: 35778855065 Ref: library/token token VBAREQUAL8855127 Ref: 35788855127 Ref: library/token token CIRCUMFLEXEQUAL8855188 Ref: 35798855188 Ref: library/token token LEFTSHIFTEQUAL8855255 Ref: 357a8855255 Ref: library/token token RIGHTSHIFTEQUAL8855322 Ref: 357b8855322 Ref: library/token token DOUBLESTAREQUAL8855390 Ref: 357c8855390 Ref: library/token token DOUBLESLASH8855458 Ref: 357d8855458 Ref: library/token token DOUBLESLASHEQUAL8855521 Ref: 357e8855521 Ref: library/token token AT8855590 Ref: 357f8855590 Ref: library/token token ATEQUAL8855643 Ref: 35808855643 Ref: library/token token RARROW8855702 Ref: 35818855702 Ref: library/token token ELLIPSIS8855760 Ref: 35828855760 Ref: library/token token COLONEQUAL8855821 Ref: 35838855821 Ref: library/token token OP8855883 Ref: 35848855883 Ref: library/token token AWAIT8855903 Ref: 35858855903 Ref: library/token token ASYNC8855926 Ref: 35868855926 Ref: library/token token TYPE_IGNORE8855949 Ref: 35878855949 Ref: library/token token TYPE_COMMENT8855978 Ref: 35888855978 Ref: library/token token ERRORTOKEN8856008 Ref: 35898856008 Ref: library/token token N_TOKENS8856036 Ref: 358a8856036 Ref: library/token token NT_OFFSET8856062 Ref: 358b8856062 Ref: library/token token COMMENT8856207 Ref: 358c8856207 Ref: library/token token NL8856278 Ref: 358d8856278 Ref: library/token token ENCODING8856560 Ref: 358e8856560 Ref: token — Constants used with Python parse trees-Footnote-18857672 Node: keyword — Testing for Python keywords8857736 Ref: library/keyword doc8857942 Ref: 358f8857942 Ref: library/keyword keyword-testing-for-python-keywords8857942 Ref: 35908857942 Ref: library/keyword module-keyword8857942 Ref: a68857942 Ref: library/keyword keyword iskeyword8858233 Ref: 12f78858233 Ref: library/keyword keyword kwlist8858334 Ref: 35918858334 Ref: keyword — Testing for Python keywords-Footnote-18858638 Node: tokenize — Tokenizer for Python source8858704 Ref: library/tokenize doc8858909 Ref: 35928858909 Ref: library/tokenize module-tokenize8858909 Ref: 1118858909 Ref: library/tokenize tokenize-tokenizer-for-python-source8858909 Ref: 35938858909 Ref: tokenize — Tokenizer for Python source-Footnote-18859860 Node: Tokenizing Input8859927 Ref: library/tokenize tokenizing-input8860050 Ref: 35948860050 Ref: library/tokenize tokenize tokenize8860156 Ref: c5b8860156 Ref: library/tokenize tokenize generate_tokens8861590 Ref: 35958861590 Ref: library/tokenize tokenize untokenize8862357 Ref: 35968862357 Ref: library/tokenize tokenize detect_encoding8863301 Ref: 19408863301 Ref: library/tokenize tokenize open8864297 Ref: 193f8864297 Ref: library/tokenize tokenize TokenError8864466 Ref: 35978864466 Ref: Tokenizing Input-Footnote-18864955 Ref: Tokenizing Input-Footnote-28865004 Node: Command-Line Usage<2>8865053 Ref: library/tokenize command-line-usage8865197 Ref: 35988865197 Ref: library/tokenize tokenize-cli8865197 Ref: 35998865197 Ref: library/tokenize cmdoption-tokenize-h8865461 Ref: 359a8865461 Ref: library/tokenize cmdoption-tokenize-e8865531 Ref: 359b8865531 Node: Examples<30>8865731 Ref: library/tokenize examples8865850 Ref: 359c8865850 Node: tabnanny — Detection of ambiguous indentation8870344 Ref: library/tabnanny doc8870550 Ref: 359d8870550 Ref: library/tabnanny module-tabnanny8870550 Ref: 1008870550 Ref: library/tabnanny tabnanny-detection-of-ambiguous-indentation8870550 Ref: 359e8870550 Ref: library/tabnanny tabnanny check8871081 Ref: 359f8871081 Ref: library/tabnanny tabnanny verbose8871521 Ref: 35a08871521 Ref: library/tabnanny tabnanny filename_only8871678 Ref: 35a18871678 Ref: library/tabnanny tabnanny NannyNag8871896 Ref: 35a28871896 Ref: library/tabnanny tabnanny process_tokens8872061 Ref: 35a38872061 Ref: tabnanny — Detection of ambiguous indentation-Footnote-18872360 Node: pyclbr — Python module browser support8872427 Ref: library/pyclbr doc8872635 Ref: 35a48872635 Ref: library/pyclbr module-pyclbr8872635 Ref: d88872635 Ref: library/pyclbr pyclbr-python-module-browser-support8872635 Ref: 35a58872635 Ref: library/pyclbr pyclbr readmodule8873333 Ref: 35a68873333 Ref: library/pyclbr pyclbr readmodule_ex8873944 Ref: 35a78873944 Ref: pyclbr — Python module browser support-Footnote-18875020 Node: Function Objects8875085 Ref: library/pyclbr function-objects8875203 Ref: 35a88875203 Ref: library/pyclbr pyclbr-function-objects8875203 Ref: 35a98875203 Ref: library/pyclbr pyclbr Function file8875370 Ref: 35aa8875370 Ref: library/pyclbr pyclbr Function module8875457 Ref: 35ab8875457 Ref: library/pyclbr pyclbr Function name8875551 Ref: 35ac8875551 Ref: library/pyclbr pyclbr Function lineno8875613 Ref: 35ad8875613 Ref: library/pyclbr pyclbr Function parent8875708 Ref: 35ae8875708 Ref: library/pyclbr pyclbr Function children8875838 Ref: 35af8875838 Node: Class Objects<2>8875985 Ref: library/pyclbr class-objects8876103 Ref: 35b08876103 Ref: library/pyclbr pyclbr-class-objects8876103 Ref: 35b18876103 Ref: library/pyclbr pyclbr Class file8876282 Ref: 35b28876282 Ref: library/pyclbr pyclbr Class module8876363 Ref: 35b38876363 Ref: library/pyclbr pyclbr Class name8876451 Ref: 35b48876451 Ref: library/pyclbr pyclbr Class lineno8876507 Ref: 35b58876507 Ref: library/pyclbr pyclbr Class parent8876599 Ref: 35b68876599 Ref: library/pyclbr pyclbr Class children8876722 Ref: 35b78876722 Ref: library/pyclbr pyclbr Class super8876866 Ref: 35b88876866 Ref: library/pyclbr pyclbr Class methods8877204 Ref: 35b98877204 Node: py_compile — Compile Python source files8877394 Ref: library/py_compile doc8877599 Ref: 35ba8877599 Ref: library/py_compile module-py_compile8877599 Ref: d78877599 Ref: library/py_compile py-compile-compile-python-source-files8877599 Ref: 35bb8877599 Ref: library/py_compile py_compile PyCompileError8878224 Ref: 35bc8878224 Ref: library/py_compile py_compile compile8878353 Ref: 2158878353 Ref: library/py_compile py_compile PycInvalidationMode8882043 Ref: 35bd8882043 Ref: library/py_compile py_compile PycInvalidationMode TIMESTAMP8882464 Ref: 35bf8882464 Ref: library/py_compile py_compile PycInvalidationMode CHECKED_HASH8882746 Ref: 35be8882746 Ref: library/py_compile py_compile PycInvalidationMode UNCHECKED_HASH8882992 Ref: 35c08882992 Ref: library/py_compile py_compile main8883441 Ref: 35c18883441 Ref: py_compile — Compile Python source files-Footnote-18884315 Ref: py_compile — Compile Python source files-Footnote-28884384 Ref: py_compile — Compile Python source files-Footnote-38884433 Ref: py_compile — Compile Python source files-Footnote-48884482 Ref: py_compile — Compile Python source files-Footnote-58884531 Node: compileall — Byte-compile Python libraries8884580 Ref: library/compileall doc8884785 Ref: 35c28884785 Ref: library/compileall compileall-byte-compile-python-libraries8884785 Ref: 35c38884785 Ref: library/compileall module-compileall8884785 Ref: 218884785 Ref: compileall — Byte-compile Python libraries-Footnote-18885445 Node: Command-line use8885514 Ref: library/compileall command-line-use8885636 Ref: 35c48885636 Ref: library/compileall cmdoption-compileall-arg-directory8885787 Ref: 35c58885787 Ref: library/compileall cmdoption-compileall-arg-file8885821 Ref: 35c68885821 Ref: library/compileall cmdoption-compileall-l8886077 Ref: 35c78886077 Ref: library/compileall cmdoption-compileall-f8886235 Ref: 35c88886235 Ref: library/compileall cmdoption-compileall-q8886314 Ref: 35c98886314 Ref: library/compileall cmdoption-compileall-d8886506 Ref: 35ca8886506 Ref: library/compileall cmdoption-compileall-x8886867 Ref: 35cb8886867 Ref: library/compileall cmdoption-compileall-i8887048 Ref: 35cc8887048 Ref: library/compileall cmdoption-compileall-b8887258 Ref: 35cd8887258 Ref: library/compileall cmdoption-compileall-r8887592 Ref: 35ce8887592 Ref: library/compileall cmdoption-compileall-j8887870 Ref: 35cf8887870 Ref: library/compileall cmdoption-compileall-invalidation-mode8888057 Ref: 35d08888057 Ref: Command-line use-Footnote-18889747 Node: Public functions8889796 Ref: library/compileall public-functions8889918 Ref: 35d18889918 Ref: library/compileall compileall compile_dir8889973 Ref: 3728889973 Ref: library/compileall compileall compile_file8893127 Ref: 6bb8893127 Ref: library/compileall compileall compile_path8895277 Ref: 6bc8895277 Ref: Public functions-Footnote-18897005 Ref: Public functions-Footnote-28897054 Node: dis — Disassembler for Python bytecode8897103 Ref: library/dis doc8897309 Ref: 35d28897309 Ref: library/dis dis-disassembler-for-python-bytecode8897309 Ref: 35d38897309 Ref: library/dis module-dis8897309 Ref: 388897309 Ref: dis — Disassembler for Python bytecode-Footnote-18898749 Node: Bytecode analysis8898811 Ref: library/dis bytecode-analysis8898932 Ref: 35d48898932 Ref: library/dis dis Bytecode8899172 Ref: 8378899172 Ref: library/dis dis Bytecode from_traceback8900199 Ref: 8398900199 Ref: library/dis dis Bytecode codeobj8900423 Ref: 35d58900423 Ref: library/dis dis Bytecode first_line8900484 Ref: 35d68900484 Ref: library/dis dis Bytecode dis8900578 Ref: 8388900578 Ref: library/dis dis Bytecode info8900769 Ref: 35d78900769 Node: Analysis functions8901227 Ref: library/dis analysis-functions8901385 Ref: 35d88901385 Ref: library/dis dis code_info8901691 Ref: bce8901691 Ref: library/dis dis show_code8902230 Ref: 8328902230 Ref: library/dis dis dis8902694 Ref: 3848902694 Ref: library/dis dis distb8904130 Ref: 8338904130 Ref: library/dis dis disassemble8904526 Ref: 8348904526 Ref: library/dis dis disco8904587 Ref: 35d98904587 Ref: library/dis dis get_instructions8905474 Ref: 8368905474 Ref: library/dis dis findlinestarts8906086 Ref: 35da8906086 Ref: library/dis dis findlabels8906574 Ref: 35db8906574 Ref: library/dis dis stack_effect8906744 Ref: 83a8906744 Ref: Analysis functions-Footnote-18907312 Node: Python Bytecode Instructions8907389 Ref: library/dis bytecodes8907548 Ref: 35dc8907548 Ref: library/dis python-bytecode-instructions8907548 Ref: 35dd8907548 Ref: library/dis dis Instruction8907782 Ref: 8358907782 Ref: library/dis dis Instruction opcode8907849 Ref: 35de8907849 Ref: library/dis dis Instruction opname8908042 Ref: 35e08908042 Ref: library/dis dis Instruction arg8908110 Ref: 35e18908110 Ref: library/dis dis Instruction argval8908202 Ref: 35e28908202 Ref: library/dis dis Instruction argrepr8908289 Ref: 35e38908289 Ref: library/dis dis Instruction offset8908373 Ref: 35e48908373 Ref: library/dis dis Instruction starts_line8908457 Ref: 35e58908457 Ref: library/dis dis Instruction is_jump_target8908555 Ref: 35e68908555 Ref: library/dis opcode-NOP8908787 Ref: 35e78908787 Ref: library/dis opcode-POP_TOP8908877 Ref: 35e88908877 Ref: library/dis opcode-ROT_TWO8908941 Ref: 35e98908941 Ref: library/dis opcode-ROT_THREE8909004 Ref: 35ea8909004 Ref: library/dis opcode-ROT_FOUR8909123 Ref: 2dc8909123 Ref: library/dis opcode-DUP_TOP8909275 Ref: 35eb8909275 Ref: library/dis opcode-DUP_TOP_TWO8909374 Ref: 35ec8909374 Ref: library/dis opcode-UNARY_POSITIVE8909644 Ref: 35ed8909644 Ref: library/dis opcode-UNARY_NEGATIVE8909707 Ref: 35ee8909707 Ref: library/dis opcode-UNARY_NOT8909770 Ref: 35ef8909770 Ref: library/dis opcode-UNARY_INVERT8909831 Ref: 35f08909831 Ref: library/dis opcode-GET_ITER8909892 Ref: 35f18909892 Ref: library/dis opcode-GET_YIELD_FROM_ITER8909954 Ref: 35f28909954 Ref: library/dis opcode-BINARY_POWER8910373 Ref: 35f38910373 Ref: library/dis opcode-BINARY_MULTIPLY8910441 Ref: 35f48910441 Ref: library/dis opcode-BINARY_MATRIX_MULTIPLY8910511 Ref: 35f58910511 Ref: library/dis opcode-BINARY_FLOOR_DIVIDE8910614 Ref: 35f68910614 Ref: library/dis opcode-BINARY_TRUE_DIVIDE8910689 Ref: 35f78910689 Ref: library/dis opcode-BINARY_MODULO8910762 Ref: 35f88910762 Ref: library/dis opcode-BINARY_ADD8910830 Ref: 35f98910830 Ref: library/dis opcode-BINARY_SUBTRACT8910895 Ref: 35fa8910895 Ref: library/dis opcode-BINARY_SUBSCR8910965 Ref: 35fb8910965 Ref: library/dis opcode-BINARY_LSHIFT8911032 Ref: 35fc8911032 Ref: library/dis opcode-BINARY_RSHIFT8911101 Ref: 35fd8911101 Ref: library/dis opcode-BINARY_AND8911170 Ref: 35fe8911170 Ref: library/dis opcode-BINARY_XOR8911235 Ref: 35ff8911235 Ref: library/dis opcode-BINARY_OR8911300 Ref: 36008911300 Ref: library/dis opcode-INPLACE_POWER8911641 Ref: 36018911641 Ref: library/dis opcode-INPLACE_MULTIPLY8911719 Ref: 36028911719 Ref: library/dis opcode-INPLACE_MATRIX_MULTIPLY8911799 Ref: 36038911799 Ref: library/dis opcode-INPLACE_FLOOR_DIVIDE8911912 Ref: 36048911912 Ref: library/dis opcode-INPLACE_TRUE_DIVIDE8911997 Ref: 36058911997 Ref: library/dis opcode-INPLACE_MODULO8912080 Ref: 36068912080 Ref: library/dis opcode-INPLACE_ADD8912158 Ref: 36078912158 Ref: library/dis opcode-INPLACE_SUBTRACT8912233 Ref: 36088912233 Ref: library/dis opcode-INPLACE_LSHIFT8912313 Ref: 36098912313 Ref: library/dis opcode-INPLACE_RSHIFT8912392 Ref: 360a8912392 Ref: library/dis opcode-INPLACE_AND8912471 Ref: 360b8912471 Ref: library/dis opcode-INPLACE_XOR8912546 Ref: 360c8912546 Ref: library/dis opcode-INPLACE_OR8912621 Ref: 360d8912621 Ref: library/dis opcode-STORE_SUBSCR8912695 Ref: 360e8912695 Ref: library/dis opcode-DELETE_SUBSCR8912762 Ref: 360f8912762 Ref: library/dis opcode-GET_AWAITABLE8912848 Ref: 36108912848 Ref: library/dis opcode-GET_AITER8913128 Ref: 36118913128 Ref: library/dis opcode-GET_ANEXT8913331 Ref: 36128913331 Ref: library/dis opcode-END_ASYNC_FOR8913509 Ref: 2e28913509 Ref: library/dis opcode-BEFORE_ASYNC_WITH8913960 Ref: 36138913960 Ref: library/dis opcode-SETUP_ASYNC_WITH8914187 Ref: 36148914187 Ref: library/dis opcode-PRINT_EXPR8914302 Ref: 36158914302 Ref: library/dis opcode-SET_ADD8914538 Ref: 36168914538 Ref: library/dis opcode-LIST_APPEND8914649 Ref: 36178914649 Ref: library/dis opcode-MAP_ADD8914769 Ref: 2e48914769 Ref: library/dis opcode-RETURN_VALUE8915281 Ref: 36188915281 Ref: library/dis opcode-YIELD_VALUE8915361 Ref: 36198915361 Ref: library/dis opcode-YIELD_FROM8915444 Ref: 361a8915444 Ref: library/dis opcode-SETUP_ANNOTATIONS8915580 Ref: 61e8915580 Ref: library/dis opcode-IMPORT_STAR8915878 Ref: 361b8915878 Ref: library/dis opcode-POP_BLOCK8916117 Ref: 361c8916117 Ref: library/dis opcode-POP_EXCEPT8916278 Ref: 361d8916278 Ref: library/dis opcode-POP_FINALLY8916611 Ref: 2df8916611 Ref: library/dis opcode-BEGIN_FINALLY8917551 Ref: 2dd8917551 Ref: library/dis opcode-END_FINALLY8917829 Ref: 2e08917829 Ref: library/dis opcode-LOAD_BUILD_CLASS8918660 Ref: 361f8918660 Ref: library/dis opcode-SETUP_WITH8918828 Ref: 36208918828 Ref: library/dis opcode-WITH_CLEANUP_START8919498 Ref: 2e18919498 Ref: library/dis opcode-WITH_CLEANUP_FINISH8920256 Ref: 361e8920256 Ref: library/dis opcode-STORE_NAME8920846 Ref: 36228920846 Ref: library/dis opcode-DELETE_NAME8921100 Ref: 36258921100 Ref: library/dis opcode-UNPACK_SEQUENCE8921248 Ref: 36238921248 Ref: library/dis opcode-UNPACK_EX8921384 Ref: 36268921384 Ref: library/dis opcode-STORE_ATTR8921887 Ref: 36278921887 Ref: library/dis opcode-DELETE_ATTR8922018 Ref: 36288922018 Ref: library/dis opcode-STORE_GLOBAL8922132 Ref: 36248922132 Ref: library/dis opcode-DELETE_GLOBAL8922238 Ref: 36298922238 Ref: library/dis opcode-LOAD_CONST8922340 Ref: 362a8922340 Ref: library/dis opcode-LOAD_NAME8922426 Ref: 362b8922426 Ref: library/dis opcode-BUILD_TUPLE8922534 Ref: 362c8922534 Ref: library/dis opcode-BUILD_LIST8922681 Ref: 362d8922681 Ref: library/dis opcode-BUILD_SET8922773 Ref: 362e8922773 Ref: library/dis opcode-BUILD_MAP8922863 Ref: 362f8922863 Ref: library/dis opcode-BUILD_CONST_KEY_MAP8923223 Ref: 6178923223 Ref: library/dis opcode-BUILD_STRING8923538 Ref: 6168923538 Ref: library/dis opcode-BUILD_TUPLE_UNPACK8923701 Ref: 36308923701 Ref: library/dis opcode-BUILD_TUPLE_UNPACK_WITH_CALL8923944 Ref: 61d8923944 Ref: library/dis opcode-BUILD_LIST_UNPACK8924226 Ref: 36318924226 Ref: library/dis opcode-BUILD_SET_UNPACK8924462 Ref: 36328924462 Ref: library/dis opcode-BUILD_MAP_UNPACK8924695 Ref: 36338924695 Ref: library/dis opcode-BUILD_MAP_UNPACK_WITH_CALL8924953 Ref: 61b8924953 Ref: library/dis opcode-LOAD_ATTR8925411 Ref: 36348925411 Ref: library/dis opcode-COMPARE_OP8925503 Ref: 36358925503 Ref: library/dis opcode-IMPORT_NAME8925635 Ref: 36368925635 Ref: library/dis opcode-IMPORT_FROM8926032 Ref: 36378926032 Ref: library/dis opcode-JUMP_FORWARD8926268 Ref: 36388926268 Ref: library/dis opcode-POP_JUMP_IF_TRUE8926348 Ref: 36398926348 Ref: library/dis opcode-POP_JUMP_IF_FALSE8926495 Ref: 363a8926495 Ref: library/dis opcode-JUMP_IF_TRUE_OR_POP8926644 Ref: 363b8926644 Ref: library/dis opcode-JUMP_IF_FALSE_OR_POP8926848 Ref: 363c8926848 Ref: library/dis opcode-JUMP_ABSOLUTE8927053 Ref: 363d8927053 Ref: library/dis opcode-FOR_ITER8927129 Ref: 363e8927129 Ref: library/dis opcode-LOAD_GLOBAL8927447 Ref: 363f8927447 Ref: library/dis opcode-SETUP_FINALLY8927547 Ref: 36408927547 Ref: library/dis opcode-CALL_FINALLY8927743 Ref: 2de8927743 Ref: library/dis opcode-LOAD_FAST8927980 Ref: 36418927980 Ref: library/dis opcode-STORE_FAST8928099 Ref: 36218928099 Ref: library/dis opcode-DELETE_FAST8928193 Ref: 36428928193 Ref: library/dis opcode-LOAD_CLOSURE8928276 Ref: 36438928276 Ref: library/dis opcode-LOAD_DEREF8928575 Ref: 36448928575 Ref: library/dis opcode-LOAD_CLASSDEREF8928761 Ref: 92e8928761 Ref: library/dis opcode-STORE_DEREF8928995 Ref: 36458928995 Ref: library/dis opcode-DELETE_DEREF8929121 Ref: 36468929121 Ref: library/dis opcode-RAISE_VARARGS8929306 Ref: 36478929306 Ref: library/dis opcode-CALL_FUNCTION8929731 Ref: 6198929731 Ref: library/dis opcode-CALL_FUNCTION_KW8930331 Ref: 61a8930331 Ref: library/dis opcode-CALL_FUNCTION_EX8931183 Ref: 61c8931183 Ref: library/dis opcode-LOAD_METHOD8932155 Ref: 4ad8932155 Ref: library/dis opcode-CALL_METHOD8932649 Ref: 4ae8932649 Ref: library/dis opcode-MAKE_FUNCTION8933182 Ref: 6188933182 Ref: library/dis opcode-BUILD_SLICE8933869 Ref: 36488933869 Ref: library/dis opcode-EXTENDED_ARG8934150 Ref: 36498934150 Ref: library/dis opcode-FORMAT_VALUE8934487 Ref: 6158934487 Ref: library/dis opcode-HAVE_ARGUMENT8935347 Ref: 364a8935347 Node: Opcode collections8935772 Ref: library/dis id18935904 Ref: 364b8935904 Ref: library/dis opcode-collections8935904 Ref: 35df8935904 Ref: library/dis dis opname8936049 Ref: 364c8936049 Ref: library/dis dis opmap8936136 Ref: 364d8936136 Ref: library/dis dis cmp_op8936212 Ref: 364e8936212 Ref: library/dis dis hasconst8936281 Ref: 364f8936281 Ref: library/dis dis hasfree8936357 Ref: 36508936357 Ref: library/dis dis hasname8936693 Ref: 36518936693 Ref: library/dis dis hasjrel8936778 Ref: 36528936778 Ref: library/dis dis hasjabs8936863 Ref: 36538936863 Ref: library/dis dis haslocal8936949 Ref: 36548936949 Ref: library/dis dis hascompare8937031 Ref: 36558937031 Node: pickletools — Tools for pickle developers8937108 Ref: library/pickletools doc8937261 Ref: 36568937261 Ref: library/pickletools module-pickletools8937261 Ref: cb8937261 Ref: library/pickletools pickletools-tools-for-pickle-developers8937261 Ref: 36578937261 Ref: pickletools — Tools for pickle developers-Footnote-18938052 Node: Command line usage<2>8938122 Ref: library/pickletools command-line-usage8938257 Ref: 36588938257 Node: Command line options<3>8939210 Ref: library/pickletools command-line-options8939291 Ref: 36598939291 Ref: library/pickletools cmdoption-pickletools-a8939354 Ref: 365a8939354 Ref: library/pickletools cmdoption-pickletools-o8939448 Ref: 365b8939448 Ref: library/pickletools cmdoption-pickletools-l8939546 Ref: 365c8939546 Ref: library/pickletools cmdoption-pickletools-m8939655 Ref: 365d8939655 Ref: library/pickletools cmdoption-pickletools-p8939775 Ref: 365e8939775 Node: Programmatic Interface<2>8939925 Ref: library/pickletools programmatic-interface8940060 Ref: 365f8940060 Ref: library/pickletools pickletools dis8940127 Ref: 5708940127 Ref: library/pickletools pickletools genops8940956 Ref: 36608940956 Ref: library/pickletools pickletools optimize8941393 Ref: 19818941393 Node: Miscellaneous Services8941673 Ref: library/misc doc8941829 Ref: 36618941829 Ref: library/misc misc8941829 Ref: 36628941829 Ref: library/misc miscellaneous-services8941829 Ref: 36638941829 Node: formatter — Generic output formatting8942076 Ref: library/formatter doc8942174 Ref: 36648942174 Ref: library/formatter formatter-generic-output-formatting8942174 Ref: 36658942174 Ref: library/formatter module-formatter8942174 Ref: 828942174 Node: The Formatter Interface8943757 Ref: library/formatter formatter-interface8943890 Ref: 36668943890 Ref: library/formatter the-formatter-interface8943890 Ref: 36678943890 Ref: library/formatter formatter AS_IS8944218 Ref: 36688944218 Ref: library/formatter formatter formatter writer8944665 Ref: 36698944665 Ref: library/formatter formatter formatter end_paragraph8944760 Ref: 366a8944760 Ref: library/formatter formatter formatter add_line_break8944907 Ref: 366b8944907 Ref: library/formatter formatter formatter add_hor_rule8945056 Ref: 366c8945056 Ref: library/formatter formatter formatter add_flowing_data8945369 Ref: 366d8945369 Ref: library/formatter formatter formatter add_literal_data8945889 Ref: 366e8945889 Ref: library/formatter formatter formatter add_label_data8946108 Ref: 366f8946108 Ref: library/formatter formatter formatter flush_softspace8947535 Ref: 36708947535 Ref: library/formatter formatter formatter push_alignment8947800 Ref: 36718947800 Ref: library/formatter formatter formatter pop_alignment8948119 Ref: 36728948119 Ref: library/formatter formatter formatter push_font8948197 Ref: 36738948197 Ref: library/formatter formatter formatter pop_font8948578 Ref: 36748948578 Ref: library/formatter formatter formatter push_margin8948646 Ref: 36758948646 Ref: library/formatter formatter formatter pop_margin8949013 Ref: 36768949013 Ref: library/formatter formatter formatter push_style8949085 Ref: 36778949085 Ref: library/formatter formatter formatter pop_style8949388 Ref: 36788949388 Ref: library/formatter formatter formatter set_spacing8949655 Ref: 36798949655 Ref: library/formatter formatter formatter assert_line_data8949744 Ref: 367a8949744 Node: Formatter Implementations8950102 Ref: library/formatter formatter-implementations8950264 Ref: 367b8950264 Ref: library/formatter formatter-impls8950264 Ref: 367c8950264 Ref: library/formatter formatter NullFormatter8950490 Ref: 367d8950490 Ref: library/formatter formatter AbstractFormatter8950878 Ref: 367f8950878 Node: The Writer Interface8951165 Ref: library/formatter the-writer-interface8951326 Ref: 36808951326 Ref: library/formatter writer-interface8951326 Ref: 36818951326 Ref: library/formatter formatter writer flush8951747 Ref: 36828951747 Ref: library/formatter formatter writer new_alignment8951834 Ref: 36838951834 Ref: library/formatter formatter writer new_font8952198 Ref: 36848952198 Ref: library/formatter formatter writer new_margin8952724 Ref: 36858952724 Ref: library/formatter formatter writer new_spacing8953054 Ref: 36868953054 Ref: library/formatter formatter writer new_styles8953138 Ref: 36878953138 Ref: library/formatter formatter writer send_line_break8953472 Ref: 36888953472 Ref: library/formatter formatter writer send_paragraph8953541 Ref: 36898953541 Ref: library/formatter formatter writer send_hor_rule8954017 Ref: 368a8954017 Ref: library/formatter formatter writer send_flowing_data8954368 Ref: 368b8954368 Ref: library/formatter formatter writer send_literal_data8954668 Ref: 368c8954668 Ref: library/formatter formatter writer send_label_data8955098 Ref: 368d8955098 Node: Writer Implementations8955404 Ref: library/formatter writer-implementations8955531 Ref: 368e8955531 Ref: library/formatter writer-impls8955531 Ref: 368f8955531 Ref: library/formatter formatter NullWriter8955789 Ref: 367e8955789 Ref: library/formatter formatter AbstractWriter8956034 Ref: 36908956034 Ref: library/formatter formatter DumbWriter8956250 Ref: 36918956250 Node: MS Windows Specific Services8956616 Ref: library/windows doc8956770 Ref: 36928956770 Ref: library/windows ms-windows-specific-services8956770 Ref: 36938956770 Ref: library/windows mswin-specific-services8956770 Ref: 10338956770 Node: msilib — Read and write Microsoft Installer files8957134 Ref: library/msilib doc8957310 Ref: 36948957310 Ref: library/msilib module-msilib8957310 Ref: b58957310 Ref: library/msilib msilib-read-and-write-microsoft-installer-files8957310 Ref: 36958957310 Ref: library/msilib msilib FCICreate8958384 Ref: 36968958384 Ref: library/msilib msilib UuidCreate8958885 Ref: 36978958885 Ref: library/msilib msilib OpenDatabase8959081 Ref: 36988959081 Ref: library/msilib msilib CreateRecord8959633 Ref: 36998959633 Ref: library/msilib msilib init_database8959798 Ref: 369a8959798 Ref: library/msilib msilib add_data8960369 Ref: 369c8960369 Ref: library/msilib msilib Binary8960943 Ref: 369d8960943 Ref: library/msilib msilib add_tables8961139 Ref: 369e8961139 Ref: library/msilib msilib add_stream8961480 Ref: 369f8961480 Ref: library/msilib msilib gen_uuid8961640 Ref: 36a08961640 Ref: msilib — Read and write Microsoft Installer files-Footnote-18962119 Ref: msilib — Read and write Microsoft Installer files-Footnote-28962193 Ref: msilib — Read and write Microsoft Installer files-Footnote-38962256 Ref: msilib — Read and write Microsoft Installer files-Footnote-48962336 Node: Database Objects8962416 Ref: library/msilib database-objects8962541 Ref: 36a18962541 Ref: library/msilib id18962541 Ref: 36a28962541 Ref: library/msilib msilib Database OpenView8962594 Ref: 36a38962594 Ref: library/msilib msilib Database Commit8962744 Ref: 36a48962744 Ref: library/msilib msilib Database GetSummaryInformation8962880 Ref: 36a58962880 Ref: library/msilib msilib Database Close8963084 Ref: 3ae8963084 Ref: Database Objects-Footnote-18963352 Ref: Database Objects-Footnote-28963432 Ref: Database Objects-Footnote-38963512 Ref: Database Objects-Footnote-48963592 Node: View Objects8963672 Ref: library/msilib id28963833 Ref: 36a68963833 Ref: library/msilib view-objects8963833 Ref: 36a78963833 Ref: library/msilib msilib View Execute8963878 Ref: 36a88963878 Ref: library/msilib msilib View GetColumnInfo8964106 Ref: 36a98964106 Ref: library/msilib msilib View Fetch8964331 Ref: 36aa8964331 Ref: library/msilib msilib View Modify8964444 Ref: 36ab8964444 Ref: library/msilib msilib View Close8964995 Ref: 36ac8964995 Ref: View Objects-Footnote-18965221 Ref: View Objects-Footnote-28965301 Ref: View Objects-Footnote-38965381 Ref: View Objects-Footnote-48965461 Ref: View Objects-Footnote-58965541 Node: Summary Information Objects8965621 Ref: library/msilib summary-information-objects8965780 Ref: 36ad8965780 Ref: library/msilib summary-objects8965780 Ref: 36ae8965780 Ref: library/msilib msilib SummaryInformation GetProperty8965855 Ref: 36af8965855 Ref: library/msilib msilib SummaryInformation GetPropertyCount8966446 Ref: 36b08966446 Ref: library/msilib msilib SummaryInformation SetProperty8966598 Ref: 36b18966598 Ref: library/msilib msilib SummaryInformation Persist8966891 Ref: 36b28966891 Ref: Summary Information Objects-Footnote-18967220 Ref: Summary Information Objects-Footnote-28967300 Ref: Summary Information Objects-Footnote-38967380 Ref: Summary Information Objects-Footnote-48967460 Node: Record Objects8967540 Ref: library/msilib id38967693 Ref: 36b38967693 Ref: library/msilib record-objects8967693 Ref: 36b48967693 Ref: library/msilib msilib Record GetFieldCount8967742 Ref: 36b58967742 Ref: library/msilib msilib Record GetInteger8967873 Ref: 36b68967873 Ref: library/msilib msilib Record GetString8968010 Ref: 36b78968010 Ref: library/msilib msilib Record SetString8968144 Ref: 36b88968144 Ref: library/msilib msilib Record SetStream8968306 Ref: 36b98968306 Ref: library/msilib msilib Record SetInteger8968505 Ref: 36ba8968505 Ref: library/msilib msilib Record ClearData8968668 Ref: 36bb8968668 Ref: Record Objects-Footnote-18968949 Ref: Record Objects-Footnote-28969029 Ref: Record Objects-Footnote-38969109 Ref: Record Objects-Footnote-48969189 Ref: Record Objects-Footnote-58969269 Node: Errors8969349 Ref: library/msilib errors8969486 Ref: 36bc8969486 Ref: library/msilib msi-errors8969486 Ref: 36bd8969486 Node: CAB Objects8969634 Ref: library/msilib cab8969774 Ref: 36be8969774 Ref: library/msilib cab-objects8969774 Ref: 36bf8969774 Ref: library/msilib msilib CAB8969817 Ref: 36c08969817 Ref: library/msilib msilib CAB append8970178 Ref: 36c18970178 Ref: library/msilib msilib CAB commit8970527 Ref: 36c28970527 Node: Directory Objects8970731 Ref: library/msilib directory-objects8970876 Ref: 36c38970876 Ref: library/msilib msi-directory8970876 Ref: 36c48970876 Ref: library/msilib msilib Directory8970931 Ref: 36c58970931 Ref: library/msilib msilib Directory start_component8971700 Ref: 36c68971700 Ref: library/msilib msilib Directory add_file8972241 Ref: 36c78972241 Ref: library/msilib msilib Directory glob8972738 Ref: 36c88972738 Ref: library/msilib msilib Directory remove_pyc8972952 Ref: 36c98972952 Ref: Directory Objects-Footnote-18973168 Ref: Directory Objects-Footnote-28973248 Ref: Directory Objects-Footnote-38973328 Ref: Directory Objects-Footnote-48973408 Node: Features<3>8973488 Ref: library/msilib features8973633 Ref: 36ca8973633 Ref: library/msilib id48973633 Ref: 36cb8973633 Ref: library/msilib msilib Feature8973670 Ref: 36cc8973670 Ref: library/msilib msilib Feature set_current8974068 Ref: 36cd8974068 Ref: Features<3>-Footnote-18974369 Node: GUI classes8974449 Ref: library/msilib gui-classes8974595 Ref: 36ce8974595 Ref: library/msilib msi-gui8974595 Ref: 36cf8974595 Ref: library/msilib msilib Control8974876 Ref: 36d08974876 Ref: library/msilib msilib Control event8975049 Ref: 36d18975049 Ref: library/msilib msilib Control mapping8975196 Ref: 36d28975196 Ref: library/msilib msilib Control condition8975318 Ref: 36d38975318 Ref: library/msilib msilib RadioButtonGroup8975457 Ref: 36d48975457 Ref: library/msilib msilib RadioButtonGroup add8975655 Ref: 36d58975655 Ref: library/msilib msilib Dialog8975925 Ref: 36d68975925 Ref: library/msilib msilib Dialog control8976230 Ref: 36d78976230 Ref: library/msilib msilib Dialog text8976593 Ref: 36d88976593 Ref: library/msilib msilib Dialog bitmap8976710 Ref: 36d98976710 Ref: library/msilib msilib Dialog line8976819 Ref: 36da8976819 Ref: library/msilib msilib Dialog pushbutton8976918 Ref: 36db8976918 Ref: library/msilib msilib Dialog radiogroup8977076 Ref: 36dc8977076 Ref: library/msilib msilib Dialog checkbox8977250 Ref: 36dd8977250 Ref: GUI classes-Footnote-18977611 Ref: GUI classes-Footnote-28977691 Ref: GUI classes-Footnote-38977771 Ref: GUI classes-Footnote-48977851 Ref: GUI classes-Footnote-58977931 Ref: GUI classes-Footnote-68978011 Ref: GUI classes-Footnote-78978091 Node: Precomputed tables8978171 Ref: library/msilib msi-tables8978297 Ref: 36de8978297 Ref: library/msilib precomputed-tables8978297 Ref: 36df8978297 Ref: library/msilib msilib schema8978510 Ref: 369b8978510 Ref: library/msilib msilib sequence8978727 Ref: 36e08978727 Ref: library/msilib msilib text8978962 Ref: 36e18978962 Node: msvcrt — Useful routines from the MS VC++ runtime8979103 Ref: library/msvcrt doc8979322 Ref: 36e28979322 Ref: library/msvcrt module-msvcrt8979322 Ref: b68979322 Ref: library/msvcrt msvcrt-useful-routines-from-the-ms-vc-runtime8979322 Ref: 36e38979322 Node: File Operations8980337 Ref: library/msvcrt file-operations8980460 Ref: 36e48980460 Ref: library/msvcrt msvcrt-files8980460 Ref: 36e58980460 Ref: library/msvcrt msvcrt locking8980511 Ref: 31f78980511 Ref: library/msvcrt msvcrt LK_LOCK8981174 Ref: 36e68981174 Ref: library/msvcrt msvcrt LK_RLCK8981199 Ref: 36e78981199 Ref: library/msvcrt msvcrt LK_NBLCK8981440 Ref: 36e88981440 Ref: library/msvcrt msvcrt LK_NBRLCK8981466 Ref: 36e98981466 Ref: library/msvcrt msvcrt LK_UNLCK8981595 Ref: 36ea8981595 Ref: library/msvcrt msvcrt setmode8981702 Ref: 36eb8981702 Ref: library/msvcrt msvcrt open_osfhandle8981941 Ref: 31f88981941 Ref: library/msvcrt msvcrt get_osfhandle8982439 Ref: 31f68982439 Node: Console I/O8982698 Ref: library/msvcrt console-i-o8982845 Ref: 36ec8982845 Ref: library/msvcrt msvcrt-console8982845 Ref: 36ed8982845 Ref: library/msvcrt msvcrt kbhit8982888 Ref: 36ee8982888 Ref: library/msvcrt msvcrt getch8982980 Ref: 36ef8982980 Ref: library/msvcrt msvcrt getwch8983461 Ref: 36f08983461 Ref: library/msvcrt msvcrt getche8983573 Ref: 36f18983573 Ref: library/msvcrt msvcrt getwche8983720 Ref: 36f28983720 Ref: library/msvcrt msvcrt putch8983834 Ref: 36f38983834 Ref: library/msvcrt msvcrt putwch8983938 Ref: 36f48983938 Ref: library/msvcrt msvcrt ungetch8984062 Ref: 36f58984062 Ref: library/msvcrt msvcrt ungetwch8984277 Ref: 36f68984277 Node: Other Functions8984405 Ref: library/msvcrt msvcrt-other8984528 Ref: 36f78984528 Ref: library/msvcrt other-functions8984528 Ref: 36f88984528 Ref: library/msvcrt msvcrt heapmin8984579 Ref: 36f98984579 Node: winreg — Windows registry access8984772 Ref: library/winreg doc8984988 Ref: 36fa8984988 Ref: library/winreg module-winreg8984988 Ref: 12a8984988 Ref: library/winreg winreg-windows-registry-access8984988 Ref: 36fb8984988 Ref: library/winreg exception-changed8985402 Ref: 36fd8985402 Node: Functions<11>8985642 Ref: library/winreg functions8985748 Ref: 36fe8985748 Ref: library/winreg id18985748 Ref: 36ff8985748 Ref: library/winreg winreg CloseKey8985832 Ref: 37008985832 Ref: library/winreg winreg ConnectRegistry8986153 Ref: 31fd8986153 Ref: library/winreg winreg CreateKey8986844 Ref: 31fe8986844 Ref: library/winreg winreg CreateKeyEx8987804 Ref: 31ff8987804 Ref: library/winreg winreg DeleteKey8989140 Ref: 32008989140 Ref: library/winreg winreg DeleteKeyEx8989888 Ref: 32018989888 Ref: library/winreg winreg DeleteValue8991350 Ref: 32028991350 Ref: library/winreg winreg EnumKey8991717 Ref: 32058991717 Ref: library/winreg winreg EnumValue8992383 Ref: 32068992383 Ref: library/winreg winreg ExpandEnvironmentStrings8993648 Ref: 32078993648 Ref: library/winreg winreg FlushKey8993998 Ref: 37078993998 Ref: library/winreg winreg LoadKey8994818 Ref: 32088994818 Ref: library/winreg winreg OpenKey8996010 Ref: 32098996010 Ref: library/winreg winreg OpenKeyEx8996083 Ref: 370a8996083 Ref: library/winreg winreg QueryInfoKey8997164 Ref: 320b8997164 Ref: library/winreg winreg QueryValue8998059 Ref: 320d8998059 Ref: library/winreg winreg QueryValueEx8998935 Ref: 320e8998935 Ref: library/winreg winreg SaveKey8999810 Ref: 320f8999810 Ref: library/winreg winreg SetValue9000855 Ref: 32109000855 Ref: library/winreg winreg SetValueEx9002033 Ref: 32119002033 Ref: library/winreg winreg DisableReflectionKey9003280 Ref: 32039003280 Ref: library/winreg winreg EnableReflectionKey9003911 Ref: 32049003911 Ref: library/winreg winreg QueryReflectionKey9004419 Ref: 320c9004419 Ref: Functions<11>-Footnote-19004922 Ref: Functions<11>-Footnote-29004996 Ref: Functions<11>-Footnote-39005073 Node: Constants<10>9005150 Ref: library/winreg constants9005288 Ref: 370f9005288 Ref: library/winreg id29005288 Ref: 37109005288 Node: HKEY_* Constants9005470 Ref: library/winreg hkey-constants9005558 Ref: 37029005558 Ref: library/winreg id39005558 Ref: 37119005558 Ref: library/winreg winreg HKEY_CLASSES_ROOT9005611 Ref: 37129005611 Ref: library/winreg winreg HKEY_CURRENT_USER9005862 Ref: 37139005862 Ref: library/winreg winreg HKEY_LOCAL_MACHINE9006165 Ref: 37099006165 Ref: library/winreg winreg HKEY_USERS9006389 Ref: 37089006389 Ref: library/winreg winreg HKEY_PERFORMANCE_DATA9006598 Ref: 37149006598 Ref: library/winreg winreg HKEY_CURRENT_CONFIG9006865 Ref: 37159006865 Ref: library/winreg winreg HKEY_DYN_DATA9007000 Ref: 37169007000 Node: Access Rights9007092 Ref: library/winreg access-rights9007200 Ref: 37049007200 Ref: library/winreg id49007200 Ref: 37179007200 Ref: library/winreg winreg KEY_ALL_ACCESS9007311 Ref: 37189007311 Ref: library/winreg winreg KEY_WRITE9007600 Ref: 37039007600 Ref: library/winreg winreg KEY_READ9007753 Ref: 370b9007753 Ref: library/winreg winreg KEY_EXECUTE9007932 Ref: 371e9007932 Ref: library/winreg winreg KEY_QUERY_VALUE9008004 Ref: 37199008004 Ref: library/winreg winreg KEY_SET_VALUE9008092 Ref: 370d9008092 Ref: library/winreg winreg KEY_CREATE_SUB_KEY9008183 Ref: 371a9008183 Ref: library/winreg winreg KEY_ENUMERATE_SUB_KEYS9008273 Ref: 371b9008273 Ref: library/winreg winreg KEY_NOTIFY9008373 Ref: 371c9008373 Ref: library/winreg winreg KEY_CREATE_LINK9008507 Ref: 371d9008507 Ref: Access Rights-Footnote-19008638 Node: 64-bit Specific9008715 Ref: library/winreg bit-access-rights9008780 Ref: 371f9008780 Ref: library/winreg bit-specific9008780 Ref: 37209008780 Ref: library/winreg winreg KEY_WOW64_64KEY9008899 Ref: 37059008899 Ref: library/winreg winreg KEY_WOW64_32KEY9009036 Ref: 37219009036 Ref: 64-bit Specific-Footnote-19009209 Node: Value Types9009281 Ref: library/winreg id59009364 Ref: 37229009364 Ref: library/winreg value-types9009364 Ref: 370e9009364 Ref: library/winreg winreg REG_BINARY9009459 Ref: 37239009459 Ref: library/winreg winreg REG_DWORD9009519 Ref: 37249009519 Ref: library/winreg winreg REG_DWORD_LITTLE_ENDIAN9009568 Ref: 37259009568 Ref: library/winreg winreg REG_DWORD_BIG_ENDIAN9009700 Ref: 37269009700 Ref: library/winreg winreg REG_EXPAND_SZ9009783 Ref: 37069009783 Ref: library/winreg winreg REG_LINK9009912 Ref: 37279009912 Ref: library/winreg winreg REG_MULTI_SZ9009970 Ref: 37289009970 Ref: library/winreg winreg REG_NONE9010136 Ref: 37299010136 Ref: library/winreg winreg REG_QWORD9010192 Ref: 5b29010192 Ref: library/winreg winreg REG_QWORD_LITTLE_ENDIAN9010269 Ref: 372a9010269 Ref: library/winreg winreg REG_RESOURCE_LIST9010426 Ref: 372b9010426 Ref: library/winreg winreg REG_FULL_RESOURCE_DESCRIPTOR9010499 Ref: 372c9010499 Ref: library/winreg winreg REG_RESOURCE_REQUIREMENTS_LIST9010572 Ref: 372d9010572 Ref: library/winreg winreg REG_SZ9010653 Ref: 370c9010653 Ref: Value Types-Footnote-19010746 Node: Registry Handle Objects9010823 Ref: library/winreg handle-object9010939 Ref: 36fc9010939 Ref: library/winreg registry-handle-objects9010939 Ref: 372e9010939 Ref: library/winreg winreg PyHKEY Close9012099 Ref: 37019012099 Ref: library/winreg winreg PyHKEY Detach9012231 Ref: 320a9012231 Ref: library/winreg winreg PyHKEY __enter__9012829 Ref: 372f9012829 Ref: library/winreg winreg PyHKEY __exit__9012861 Ref: 37309012861 Node: winsound — Sound-playing interface for Windows9013255 Ref: library/winsound doc9013411 Ref: 37319013411 Ref: library/winsound module-winsound9013411 Ref: 12b9013411 Ref: library/winsound winsound-sound-playing-interface-for-windows9013411 Ref: 37329013411 Ref: library/winsound winsound Beep9013761 Ref: 5b49013761 Ref: library/winsound winsound PlaySound9014149 Ref: 5b69014149 Ref: library/winsound winsound MessageBeep9014721 Ref: 5b59014721 Ref: library/winsound winsound SND_FILENAME9015330 Ref: 37339015330 Ref: library/winsound winsound SND_ALIAS9015463 Ref: 37349015463 Ref: library/winsound winsound SND_LOOP9017081 Ref: 37369017081 Ref: library/winsound winsound SND_MEMORY9017268 Ref: 37389017268 Ref: library/winsound winsound SND_PURGE9017630 Ref: 37399017630 Ref: library/winsound winsound SND_ASYNC9017790 Ref: 37379017790 Ref: library/winsound winsound SND_NODEFAULT9017886 Ref: 37359017886 Ref: library/winsound winsound SND_NOSTOP9018009 Ref: 373a9018009 Ref: library/winsound winsound SND_NOWAIT9018089 Ref: 373b9018089 Ref: library/winsound winsound MB_ICONASTERISK9018247 Ref: 373c9018247 Ref: library/winsound winsound MB_ICONEXCLAMATION9018325 Ref: 373d9018325 Ref: library/winsound winsound MB_ICONHAND9018410 Ref: 373e9018410 Ref: library/winsound winsound MB_ICONQUESTION9018481 Ref: 373f9018481 Ref: library/winsound winsound MB_OK9018560 Ref: 37409018560 Node: Unix Specific Services9018628 Ref: library/unix doc9018778 Ref: 37419018778 Ref: library/unix unix9018778 Ref: 37429018778 Ref: library/unix unix-specific-services9018778 Ref: 37439018778 Node: posix — The most common POSIX system calls9019629 Ref: library/posix doc9019770 Ref: 37449019770 Ref: library/posix module-posix9019770 Ref: d19019770 Ref: library/posix posix-the-most-common-posix-system-calls9019770 Ref: 37459019770 Node: Large File Support9020970 Ref: library/posix large-file-support9021101 Ref: 37469021101 Ref: library/posix posix-large-files9021101 Ref: 37479021101 Node: Notable Module Contents9022152 Ref: library/posix notable-module-contents9022283 Ref: 37489022283 Ref: library/posix posix-contents9022283 Ref: 37499022283 Ref: library/posix posix environ9022484 Ref: 374a9022484 Node: pwd — The password database9023670 Ref: library/pwd doc9023857 Ref: 374b9023857 Ref: library/pwd module-pwd9023857 Ref: d69023857 Ref: library/pwd pwd-the-password-database9023857 Ref: 374c9023857 Ref: library/pwd pwd getpwuid9026132 Ref: 374d9026132 Ref: library/pwd pwd getpwnam9026238 Ref: 374e9026238 Ref: library/pwd pwd getpwall9026339 Ref: 374f9026339 Node: spwd — The shadow password database9026653 Ref: library/spwd doc9026822 Ref: 37509026822 Ref: library/spwd module-spwd9026822 Ref: f19026822 Ref: library/spwd spwd-the-shadow-password-database9026822 Ref: 37519026822 Ref: library/spwd spwd getspnam9029116 Ref: 5fe9029116 Ref: library/spwd spwd getspall9029373 Ref: 37529029373 Node: grp — The group database9029694 Ref: library/grp doc9029876 Ref: 37539029876 Ref: library/grp grp-the-group-database9029876 Ref: 37549029876 Ref: library/grp module-grp9029876 Ref: 8b9029876 Ref: library/grp grp getgrgid9031420 Ref: 5df9031420 Ref: library/grp grp getgrnam9031769 Ref: 37559031769 Ref: library/grp grp getgrall9031945 Ref: 37569031945 Node: crypt — Function to check Unix passwords9032241 Ref: library/crypt doc9032421 Ref: 37579032421 Ref: library/crypt crypt-function-to-check-unix-passwords9032421 Ref: 37589032421 Ref: library/crypt module-crypt9032421 Ref: 299032421 Ref: crypt — Function to check Unix passwords-Footnote-19033429 Node: Hashing Methods9033493 Ref: library/crypt hashing-methods9033613 Ref: 37599033613 Ref: library/crypt crypt METHOD_SHA5129033800 Ref: 375a9033800 Ref: library/crypt crypt METHOD_SHA2569033989 Ref: 375b9033989 Ref: library/crypt crypt METHOD_BLOWFISH9034148 Ref: 375c9034148 Ref: library/crypt crypt METHOD_MD59034329 Ref: 375d9034329 Ref: library/crypt crypt METHOD_CRYPT9034480 Ref: 6099034480 Node: Module Attributes9034624 Ref: library/crypt module-attributes9034772 Ref: 375e9034772 Ref: library/crypt crypt methods9034848 Ref: 375f9034848 Node: Module Functions<2>9035024 Ref: library/crypt module-functions9035169 Ref: 37609035169 Ref: library/crypt crypt crypt9035284 Ref: 37619035284 Ref: library/crypt crypt mksalt9036788 Ref: 37c9036788 Node: Examples<31>9037641 Ref: library/crypt examples9037760 Ref: 37629037760 Node: termios — POSIX style tty control9038901 Ref: library/termios doc9039089 Ref: 37639039089 Ref: library/termios module-termios9039089 Ref: 1049039089 Ref: library/termios termios-posix-style-tty-control9039089 Ref: 37649039089 Ref: library/termios termios tcgetattr9040066 Ref: 37659040066 Ref: library/termios termios tcsetattr9040645 Ref: 37669040645 Ref: library/termios termios tcsendbreak9041139 Ref: 37679041139 Ref: library/termios termios tcdrain9041353 Ref: 37689041353 Ref: library/termios termios tcflush9041476 Ref: 37699041476 Ref: library/termios termios tcflow9041734 Ref: 376a9041734 Node: Example<16>9042159 Ref: library/termios example9042242 Ref: 376b9042242 Ref: library/termios termios-example9042242 Ref: 376c9042242 Node: tty — Terminal control functions9043000 Ref: library/tty doc9043179 Ref: 376d9043179 Ref: library/tty module-tty9043179 Ref: 1159043179 Ref: library/tty tty-terminal-control-functions9043179 Ref: 376e9043179 Ref: library/tty tty setraw9043602 Ref: 376f9043602 Ref: library/tty tty setcbreak9043838 Ref: 37709043838 Ref: tty — Terminal control functions-Footnote-19044203 Node: pty — Pseudo-terminal utilities9044265 Ref: library/pty doc9044451 Ref: 37719044451 Ref: library/pty module-pty9044451 Ref: d59044451 Ref: library/pty pty-pseudo-terminal-utilities9044451 Ref: 37729044451 Ref: library/pty pty fork9045086 Ref: 37739045086 Ref: library/pty pty openpty9045501 Ref: 37749045501 Ref: library/pty pty spawn9045780 Ref: 8989045780 Ref: pty — Pseudo-terminal utilities-Footnote-19047814 Ref: pty — Pseudo-terminal utilities-Footnote-29047876 Node: Example<17>9047919 Ref: library/pty example9048000 Ref: 37759048000 Node: fcntl — The fcntl and ioctl system calls9049182 Ref: library/fcntl doc9049372 Ref: 37769049372 Ref: library/fcntl fcntl-the-fcntl-and-ioctl-system-calls9049372 Ref: 37779049372 Ref: library/fcntl module-fcntl9049372 Ref: 7e9049372 Ref: library/fcntl fcntl fcntl9050488 Ref: 23939050488 Ref: library/fcntl fcntl ioctl9051932 Ref: dde9051932 Ref: library/fcntl fcntl flock9054262 Ref: 31f39054262 Ref: library/fcntl fcntl lockf9054769 Ref: d529054769 Node: pipes — Interface to shell pipelines9057491 Ref: library/pipes doc9057687 Ref: 37789057687 Ref: library/pipes module-pipes9057687 Ref: cc9057687 Ref: library/pipes pipes-interface-to-shell-pipelines9057687 Ref: 37799057687 Ref: library/pipes pipes Template9058236 Ref: 377a9058236 Ref: pipes — Interface to shell pipelines-Footnote-19058607 Node: Template Objects9058671 Ref: library/pipes id19058762 Ref: 377b9058762 Ref: library/pipes template-objects9058762 Ref: 377c9058762 Ref: library/pipes pipes Template reset9058854 Ref: 377d9058854 Ref: library/pipes pipes Template clone9058941 Ref: 377e9058941 Ref: library/pipes pipes Template debug9059023 Ref: 377f9059023 Ref: library/pipes pipes Template append9059268 Ref: 37809059268 Ref: library/pipes pipes Template prepend9060018 Ref: 37819060018 Ref: library/pipes pipes Template open9060168 Ref: 37829060168 Ref: library/pipes pipes Template copy9060370 Ref: 37839060370 Node: resource — Resource usage information9060466 Ref: library/resource doc9060665 Ref: 37849060665 Ref: library/resource module-resource9060665 Ref: e09060665 Ref: library/resource resource-resource-usage-information9060665 Ref: 37859060665 Ref: library/resource resource error9061150 Ref: 37869061150 Ref: resource — Resource usage information-Footnote-19061424 Node: Resource Limits9061473 Ref: library/resource resource-limits9061587 Ref: 37879061587 Ref: library/resource resource RLIM_INFINITY9062466 Ref: 37889062466 Ref: library/resource resource getrlimit9062570 Ref: 37899062570 Ref: library/resource resource setrlimit9062864 Ref: 31cd9062864 Ref: library/resource resource prlimit9064022 Ref: 89f9064022 Ref: library/resource resource RLIMIT_CORE9065627 Ref: 31ce9065627 Ref: library/resource resource RLIMIT_CPU9065888 Ref: 378b9065888 Ref: library/resource resource RLIMIT_FSIZE9066248 Ref: 378c9066248 Ref: library/resource resource RLIMIT_DATA9066344 Ref: 378d9066344 Ref: library/resource resource RLIMIT_STACK9066435 Ref: 378e9066435 Ref: library/resource resource RLIMIT_RSS9066632 Ref: 378f9066632 Ref: library/resource resource RLIMIT_NPROC9066750 Ref: 37909066750 Ref: library/resource resource RLIMIT_NOFILE9066853 Ref: 378a9066853 Ref: library/resource resource RLIMIT_OFILE9066967 Ref: 37919066967 Ref: library/resource resource RLIMIT_MEMLOCK9067050 Ref: 37929067050 Ref: library/resource resource RLIMIT_VMEM9067148 Ref: 37939067148 Ref: library/resource resource RLIMIT_AS9067250 Ref: 37949067250 Ref: library/resource resource RLIMIT_MSGQUEUE9067371 Ref: 8a09067371 Ref: library/resource resource RLIMIT_NICE9067561 Ref: 8a19067561 Ref: library/resource resource RLIMIT_RTPRIO9067759 Ref: 8a29067759 Ref: library/resource resource RLIMIT_RTTIME9067919 Ref: 8a39067919 Ref: library/resource resource RLIMIT_SIGPENDING9068177 Ref: 8a49068177 Ref: library/resource resource RLIMIT_SBSIZE9068352 Ref: 8a59068352 Ref: library/resource resource RLIMIT_SWAP9068656 Ref: 8a69068656 Ref: library/resource resource RLIMIT_NPTS9069042 Ref: 8a79069042 Ref: Resource Limits-Footnote-19069258 Node: Resource Usage9069325 Ref: library/resource resource-usage9069439 Ref: 37959069439 Ref: library/resource resource getrusage9069556 Ref: d999069556 Ref: library/resource resource getpagesize9074049 Ref: 37969074049 Ref: library/resource resource RUSAGE_SELF9074353 Ref: 37979074353 Ref: library/resource resource RUSAGE_CHILDREN9074553 Ref: 37989074553 Ref: library/resource resource RUSAGE_BOTH9074752 Ref: 37999074752 Ref: library/resource resource RUSAGE_THREAD9074949 Ref: 379a9074949 Node: nis — Interface to Sun’s NIS Yellow Pages9075143 Ref: library/nis doc9075343 Ref: 379b9075343 Ref: library/nis module-nis9075343 Ref: bf9075343 Ref: library/nis nis-interface-to-sun-s-nis-yellow-pages9075343 Ref: 379c9075343 Ref: library/nis nis match9075794 Ref: d929075794 Ref: library/nis nis cat9076341 Ref: 379e9076341 Ref: library/nis nis maps9076807 Ref: d939076807 Ref: library/nis nis get_default_domain9077035 Ref: 379f9077035 Ref: library/nis nis error9077180 Ref: 379d9077180 Node: syslog — Unix syslog library routines9077271 Ref: library/syslog doc9077423 Ref: 37a09077423 Ref: library/syslog module-syslog9077423 Ref: ff9077423 Ref: library/syslog syslog-unix-syslog-library-routines9077423 Ref: 37a19077423 Ref: library/syslog syslog syslog9078004 Ref: 31fc9078004 Ref: library/syslog syslog openlog9078815 Ref: 31fa9078815 Ref: library/syslog syslog closelog9079979 Ref: 31f99079979 Ref: library/syslog syslog setlogmask9080512 Ref: 31fb9080512 Node: Examples<32>9081791 Ref: library/syslog examples9081879 Ref: 37a29081879 Node: Simple example9081947 Ref: library/syslog simple-example9082010 Ref: 37a39082010 Node: Superseded Modules9082522 Ref: library/superseded doc9082664 Ref: 37a49082664 Ref: library/superseded superseded9082664 Ref: 37a59082664 Ref: library/superseded superseded-modules9082664 Ref: 37a69082664 Node: optparse — Parser for command line options9082954 Ref: library/optparse doc9083097 Ref: 37a79083097 Ref: library/optparse module-optparse9083097 Ref: c39083097 Ref: library/optparse optparse-parser-for-command-line-options9083097 Ref: 37a89083097 Ref: optparse — Parser for command line options-Footnote-19085998 Node: Background9086065 Ref: library/optparse background9086176 Ref: 37aa9086176 Ref: library/optparse optparse-background9086176 Ref: 37ab9086176 Node: Terminology9086661 Ref: library/optparse optparse-terminology9086749 Ref: 37ac9086749 Ref: library/optparse terminology9086749 Ref: 37ad9086749 Node: What are options for?9090577 Ref: library/optparse optparse-what-options-for9090708 Ref: 37ae9090708 Ref: library/optparse what-are-options-for9090708 Ref: 37af9090708 Node: What are positional arguments for?9092393 Ref: library/optparse optparse-what-positional-arguments-for9092504 Ref: 37b09092504 Ref: library/optparse what-are-positional-arguments-for9092504 Ref: 37b19092504 Node: Tutorial<2>9093839 Ref: library/optparse optparse-tutorial9093974 Ref: 37b29093974 Ref: library/optparse tutorial9093974 Ref: 37b39093974 Node: Understanding option actions9096580 Ref: library/optparse optparse-understanding-option-actions9096681 Ref: 37b89096681 Ref: library/optparse understanding-option-actions9096681 Ref: 37b99096681 Node: The store action9097272 Ref: library/optparse optparse-store-action9097411 Ref: 37bb9097411 Ref: library/optparse the-store-action9097411 Ref: 37bc9097411 Node: Handling boolean flag options9099601 Ref: library/optparse handling-boolean-flag-options9099725 Ref: 37bd9099725 Ref: library/optparse optparse-handling-boolean-options9099725 Ref: 37be9099725 Node: Other actions9100608 Ref: library/optparse optparse-other-actions9100730 Ref: 37bf9100730 Ref: library/optparse other-actions9100730 Ref: 37c09100730 Node: Default values9101148 Ref: library/optparse default-values9101256 Ref: 37c39101256 Ref: library/optparse optparse-default-values9101256 Ref: 37c49101256 Node: Generating help9103144 Ref: library/optparse generating-help9103264 Ref: 37c59103264 Ref: library/optparse optparse-generating-help9103264 Ref: 37c69103264 Node: Grouping Options9107438 Ref: library/optparse grouping-options9107506 Ref: 37c79107506 Ref: library/optparse optparse OptionGroup9107837 Ref: 37c89107837 Ref: library/optparse optparse OptionParser get_option_group9111335 Ref: 37c99111335 Node: Printing a version string9111605 Ref: library/optparse optparse-printing-version-string9111738 Ref: 37ca9111738 Ref: library/optparse printing-a-version-string9111738 Ref: 37cb9111738 Ref: library/optparse optparse OptionParser print_version9112622 Ref: 37cc9112622 Ref: library/optparse optparse OptionParser get_version9112996 Ref: 37ce9112996 Node: How optparse handles errors9113140 Ref: library/optparse how-optparse-handles-errors9113281 Ref: 37cf9113281 Ref: library/optparse optparse-how-optparse-handles-errors9113281 Ref: 37d09113281 Node: Putting it all together9115364 Ref: library/optparse optparse-putting-it-all-together9115471 Ref: 37d19115471 Ref: library/optparse putting-it-all-together9115471 Ref: 37d29115471 Node: Reference Guide9116389 Ref: library/optparse optparse-reference-guide9116530 Ref: 37c19116530 Ref: library/optparse reference-guide9116530 Ref: 37d39116530 Node: Creating the parser9116903 Ref: library/optparse creating-the-parser9117004 Ref: 37d49117004 Ref: library/optparse optparse-creating-parser9117004 Ref: 37d59117004 Ref: library/optparse optparse OptionParser9117149 Ref: 37a99117149 Node: Populating the parser9120155 Ref: library/optparse optparse-populating-parser9120281 Ref: 37d79120281 Ref: library/optparse populating-the-parser9120281 Ref: 37d89120281 Node: Defining options9121567 Ref: library/optparse defining-options9121691 Ref: 37d99121691 Ref: library/optparse optparse-defining-options9121691 Ref: 37da9121691 Ref: library/optparse optparse OptionParser add_option9122100 Ref: 1d4f9122100 Node: Option attributes9124973 Ref: library/optparse option-attributes9125099 Ref: 37dc9125099 Ref: library/optparse optparse-option-attributes9125099 Ref: 37dd9125099 Ref: library/optparse optparse Option action9125435 Ref: 37b49125435 Ref: library/optparse optparse Option type9125658 Ref: 37b59125658 Ref: library/optparse optparse Option dest9125875 Ref: 37b69125875 Ref: library/optparse optparse Option default9126220 Ref: 37df9126220 Ref: library/optparse optparse Option nargs9126414 Ref: 37e19126414 Ref: library/optparse optparse Option const9126647 Ref: 37e29126647 Ref: library/optparse optparse Option choices9126757 Ref: 37e39126757 Ref: library/optparse optparse Option callback9126881 Ref: 37e49126881 Ref: library/optparse optparse Option callback_args9127113 Ref: 37e59127113 Ref: library/optparse optparse Option callback_kwargs9127149 Ref: 37e69127149 Ref: library/optparse optparse Option help9127313 Ref: 37b79127313 Ref: library/optparse optparse Option metavar9127661 Ref: 37e79127661 Node: Standard option actions9127866 Ref: library/optparse optparse-standard-option-actions9127997 Ref: 37db9127997 Ref: library/optparse standard-option-actions9127997 Ref: 37e89127997 Node: Standard option types9136084 Ref: library/optparse optparse-standard-option-types9136218 Ref: 37de9136218 Ref: library/optparse standard-option-types9136218 Ref: 37e99136218 Node: Parsing arguments<2>9137689 Ref: library/optparse optparse-parsing-arguments9137844 Ref: 37ea9137844 Ref: library/optparse parsing-arguments9137844 Ref: 37eb9137844 Node: Querying and manipulating your option parser9139214 Ref: library/optparse optparse-querying-manipulating-option-parser9139373 Ref: 37ec9139373 Ref: library/optparse querying-and-manipulating-your-option-parser9139373 Ref: 37ed9139373 Ref: library/optparse optparse OptionParser disable_interspersed_args9139682 Ref: 1d509139682 Ref: library/optparse optparse OptionParser enable_interspersed_args9140472 Ref: 37ee9140472 Ref: library/optparse optparse OptionParser get_option9140678 Ref: 37ef9140678 Ref: library/optparse optparse OptionParser has_option9140851 Ref: 37f09140851 Ref: library/optparse optparse OptionParser remove_option9141027 Ref: 37f19141027 Node: Conflicts between options9141413 Ref: library/optparse conflicts-between-options9141562 Ref: 37f29141562 Ref: library/optparse optparse-conflicts-between-options9141562 Ref: 37d69141562 Node: Cleanup<2>9144026 Ref: library/optparse cleanup9144144 Ref: 37f39144144 Ref: library/optparse optparse-cleanup9144144 Ref: 37f49144144 Node: Other methods9144557 Ref: library/optparse optparse-other-methods9144641 Ref: 37f59144641 Ref: library/optparse other-methods9144641 Ref: 37f69144641 Ref: library/optparse optparse OptionParser set_usage9144743 Ref: 37f79144743 Ref: library/optparse optparse OptionParser print_usage9145032 Ref: 37cd9145032 Ref: library/optparse optparse OptionParser get_usage9145368 Ref: 37f89145368 Ref: library/optparse optparse OptionParser set_defaults9145506 Ref: 37e09145506 Node: Option Callbacks9146674 Ref: library/optparse option-callbacks9146822 Ref: 37f99146822 Ref: library/optparse optparse-option-callbacks9146822 Ref: 37c29146822 Node: Defining a callback option9148039 Ref: library/optparse defining-a-callback-option9148151 Ref: 37fa9148151 Ref: library/optparse optparse-defining-callback-option9148151 Ref: 37fb9148151 Node: How callbacks are called9150376 Ref: library/optparse how-callbacks-are-called9150525 Ref: 37fc9150525 Ref: library/optparse optparse-how-callbacks-called9150525 Ref: 37fd9150525 Node: Raising errors in a callback9153135 Ref: library/optparse optparse-raising-errors-in-callback9153293 Ref: 37fe9153293 Ref: library/optparse raising-errors-in-a-callback9153293 Ref: 37ff9153293 Node: Callback example 1 trivial callback9153764 Ref: library/optparse callback-example-1-trivial-callback9153935 Ref: 38009153935 Ref: library/optparse optparse-callback-example-19153935 Ref: 38019153935 Node: Callback example 2 check option order9154383 Ref: library/optparse callback-example-2-check-option-order9154575 Ref: 38029154575 Ref: library/optparse optparse-callback-example-29154575 Ref: 38039154575 Node: Callback example 3 check option order generalized9155133 Ref: library/optparse callback-example-3-check-option-order-generalized9155334 Ref: 38049155334 Ref: library/optparse optparse-callback-example-39155334 Ref: 38059155334 Node: Callback example 4 check arbitrary condition9156108 Ref: library/optparse callback-example-4-check-arbitrary-condition9156306 Ref: 38069156306 Ref: library/optparse optparse-callback-example-49156306 Ref: 38079156306 Node: Callback example 5 fixed arguments9157101 Ref: library/optparse callback-example-5-fixed-arguments9157287 Ref: 38089157287 Ref: library/optparse optparse-callback-example-59157287 Ref: 38099157287 Node: Callback example 6 variable arguments9158361 Ref: library/optparse callback-example-6-variable-arguments9158494 Ref: 380a9158494 Ref: library/optparse optparse-callback-example-69158494 Ref: 380b9158494 Node: Extending optparse9160599 Ref: library/optparse extending-optparse9160723 Ref: 380c9160723 Ref: library/optparse optparse-extending-optparse9160723 Ref: 37ba9160723 Node: Adding new types9161060 Ref: library/optparse adding-new-types9161158 Ref: 380d9161158 Ref: library/optparse optparse-adding-new-types9161158 Ref: 380e9161158 Ref: library/optparse optparse Option TYPES9161447 Ref: 380f9161447 Ref: library/optparse optparse Option TYPE_CHECKER9161606 Ref: 38109161606 Node: Adding new actions9164617 Ref: library/optparse adding-new-actions9164715 Ref: 38119164715 Ref: library/optparse optparse-adding-new-actions9164715 Ref: 38129164715 Ref: library/optparse optparse Option ACTIONS9165818 Ref: 38139165818 Ref: library/optparse optparse Option STORE_ACTIONS9165894 Ref: 38149165894 Ref: library/optparse optparse Option TYPED_ACTIONS9165987 Ref: 38159165987 Ref: library/optparse optparse Option ALWAYS_TYPED_ACTIONS9166080 Ref: 38169166080 Node: imp — Access the import internals9169382 Ref: library/imp doc9169525 Ref: 38179169525 Ref: library/imp imp-access-the-import-internals9169525 Ref: 38189169525 Ref: library/imp module-imp9169525 Ref: 9a9169525 Ref: library/imp imp get_magic9169976 Ref: 8639169976 Ref: library/imp imp get_suffixes9170267 Ref: 38199170267 Ref: library/imp imp find_module9171005 Ref: 381d9171005 Ref: library/imp imp load_module9173518 Ref: 38219173518 Ref: library/imp imp new_module9175389 Ref: 38229175389 Ref: library/imp imp reload9175638 Ref: c709175638 Ref: library/imp imp cache_from_source9178898 Ref: 38239178898 Ref: library/imp imp source_from_cache9179954 Ref: 38259179954 Ref: library/imp imp get_tag9180689 Ref: 38249180689 Ref: library/imp imp lock_held9181240 Ref: 38269181240 Ref: library/imp imp acquire_lock9182174 Ref: 38279182174 Ref: library/imp imp release_lock9182875 Ref: 38289182875 Ref: library/imp imp PY_SOURCE9183411 Ref: 381a9183411 Ref: library/imp imp PY_COMPILED9183517 Ref: 381b9183517 Ref: library/imp imp C_EXTENSION9183639 Ref: 381c9183639 Ref: library/imp imp PKG_DIRECTORY9183769 Ref: 38209183769 Ref: library/imp imp C_BUILTIN9183885 Ref: 381e9183885 Ref: library/imp imp PY_FROZEN9183995 Ref: 381f9183995 Ref: library/imp imp NullImporter9184103 Ref: 9bb9184103 Ref: library/imp imp NullImporter find_module9184497 Ref: 38299184497 Ref: imp — Access the import internals-Footnote-19184987 Ref: imp — Access the import internals-Footnote-29185049 Ref: imp — Access the import internals-Footnote-39185098 Ref: imp — Access the import internals-Footnote-49185147 Ref: imp — Access the import internals-Footnote-59185196 Ref: imp — Access the import internals-Footnote-69185245 Ref: imp — Access the import internals-Footnote-79185294 Node: Examples<33>9185343 Ref: library/imp examples9185427 Ref: 382a9185427 Ref: library/imp examples-imp9185427 Ref: 382b9185427 Node: Undocumented Modules9186433 Ref: library/undoc doc9186544 Ref: 382c9186544 Ref: library/undoc undoc9186544 Ref: 382d9186544 Ref: library/undoc undocumented-modules9186544 Ref: 382e9186544 Node: Platform specific modules9186991 Ref: library/undoc platform-specific-modules9187073 Ref: 382f9187073 Node: Extending and Embedding the Python Interpreter9187464 Ref: extending/index doc9187624 Ref: 38309187624 Ref: extending/index extending-and-embedding-the-python-interpreter9187624 Ref: 38319187624 Ref: extending/index extending-index9187624 Ref: e909187624 Node: Recommended third party tools9188925 Ref: extending/index recommended-third-party-tools9189091 Ref: 38329189091 Ref: Recommended third party tools-Footnote-19189789 Ref: Recommended third party tools-Footnote-29189816 Ref: Recommended third party tools-Footnote-39189852 Ref: Recommended third party tools-Footnote-49189880 Ref: Recommended third party tools-Footnote-59189914 Node: Creating extensions without third party tools9189987 Ref: extending/index creating-extensions-without-third-party-tools9190215 Ref: 38339190215 Node: Extending Python with C or C++9190831 Ref: extending/extending doc9190985 Ref: 38349190985 Ref: extending/extending extending-intro9190985 Ref: 38359190985 Ref: extending/extending extending-python-with-c-or-c9190985 Ref: 38369190985 Ref: Extending Python with C or C++-Footnote-19192916 Node: A Simple Example9192953 Ref: extending/extending a-simple-example9193077 Ref: 38379193077 Ref: extending/extending extending-simpleexample9193077 Ref: 38389193077 Ref: A Simple Example-Footnote-19196812 Node: Intermezzo Errors and Exceptions9196966 Ref: extending/extending extending-errors9197118 Ref: 383a9197118 Ref: extending/extending intermezzo-errors-and-exceptions9197118 Ref: 383b9197118 Node: Back to the Example9204243 Ref: extending/extending back-to-the-example9204434 Ref: 38429204434 Ref: extending/extending backtoexample9204434 Ref: 38439204434 Node: The Module’s Method Table and Initialization Function9206096 Ref: extending/extending methodtable9206278 Ref: 38459206278 Ref: extending/extending the-module-s-method-table-and-initialization-function9206278 Ref: 38469206278 Ref: The Module’s Method Table and Initialization Function-Footnote-19211685 Node: Compilation and Linkage9211734 Ref: extending/extending compilation9211928 Ref: 38499211928 Ref: extending/extending compilation-and-linkage9211928 Ref: 384a9211928 Node: Calling Python Functions from C9213402 Ref: extending/extending calling-python-functions-from-c9213585 Ref: 384c9213585 Ref: extending/extending callingpython9213585 Ref: 384d9213585 Node: Extracting Parameters in Extension Functions9220268 Ref: extending/extending extracting-parameters-in-extension-functions9220470 Ref: 38519220470 Ref: extending/extending parsetuple9220470 Ref: 38399220470 Node: Keyword Parameters for Extension Functions9223152 Ref: extending/extending keyword-parameters-for-extension-functions9223348 Ref: 38529223348 Ref: extending/extending parsetupleandkeywords9223348 Ref: 38539223348 Node: Building Arbitrary Values9226063 Ref: extending/extending building-arbitrary-values9226231 Ref: 38549226231 Ref: extending/extending buildvalue9226231 Ref: 38559226231 Node: Reference Counts9228317 Ref: extending/extending refcounts9228468 Ref: 384e9228468 Ref: extending/extending reference-counts9228468 Ref: 38569228468 Node: Reference Counting in Python9233245 Ref: extending/extending refcountsinpython9233350 Ref: 38579233350 Ref: extending/extending reference-counting-in-python9233350 Ref: 38589233350 Ref: Reference Counting in Python-Footnote-19235727 Ref: Reference Counting in Python-Footnote-29235855 Node: Ownership Rules9236030 Ref: extending/extending ownership-rules9236152 Ref: 38599236152 Ref: extending/extending ownershiprules9236152 Ref: 385a9236152 Node: Thin Ice9238621 Ref: extending/extending thin-ice9238728 Ref: 38649238728 Ref: extending/extending thinice9238728 Ref: 38659238728 Node: NULL Pointers9242010 Ref: extending/extending null-pointers9242093 Ref: 38679242093 Ref: extending/extending nullpointers9242093 Ref: 38689242093 Ref: NULL Pointers-Footnote-19243718 Node: Writing Extensions in C++9243859 Ref: extending/extending cplusplus9244026 Ref: 38699244026 Ref: extending/extending writing-extensions-in-c9244026 Ref: 386a9244026 Node: Providing a C API for an Extension Module9244746 Ref: extending/extending providing-a-c-api-for-an-extension-module9244888 Ref: 386b9244888 Ref: extending/extending using-capsules9244888 Ref: cf19244888 Node: Defining Extension Types Tutorial9253739 Ref: extending/newtypes_tutorial doc9253942 Ref: 386f9253942 Ref: extending/newtypes_tutorial defining-extension-types-tutorial9253942 Ref: 38709253942 Ref: extending/newtypes_tutorial defining-new-types9253942 Ref: 38719253942 Node: The Basics9254586 Ref: extending/newtypes_tutorial dnt-basics9254719 Ref: 38729254719 Ref: extending/newtypes_tutorial the-basics9254719 Ref: 38739254719 Ref: The Basics-Footnote-19264034 Node: Adding data and methods to the Basic example9264104 Ref: extending/newtypes_tutorial adding-data-and-methods-to-the-basic-example9264290 Ref: 387e9264290 Ref: Adding data and methods to the Basic example-Footnote-19280544 Ref: Adding data and methods to the Basic example-Footnote-29280641 Node: Providing finer control over data attributes9280782 Ref: extending/newtypes_tutorial providing-finer-control-over-data-attributes9280994 Ref: 38899280994 Ref: Providing finer control over data attributes-Footnote-19290905 Node: Supporting cyclic garbage collection9291289 Ref: extending/newtypes_tutorial supporting-cyclic-garbage-collection9291480 Ref: 388b9291480 Ref: Supporting cyclic garbage collection-Footnote-19302119 Node: Subclassing other types9302297 Ref: extending/newtypes_tutorial subclassing-other-types9302435 Ref: 388f9302435 Node: Defining Extension Types Assorted Topics9307684 Ref: extending/newtypes doc9307886 Ref: 38929307886 Ref: extending/newtypes defining-extension-types-assorted-topics9307886 Ref: 38939307886 Ref: extending/newtypes new-types-topics9307886 Ref: 38949307886 Ref: extending/newtypes dnt-type-methods9307983 Ref: 38959307983 Node: Finalization and De-allocation9312416 Ref: extending/newtypes finalization-and-de-allocation9312551 Ref: 38969312551 Ref: Finalization and De-allocation-Footnote-19315692 Node: Object Presentation9315741 Ref: extending/newtypes object-presentation9315905 Ref: 38999315905 Node: Attribute Management9317559 Ref: extending/newtypes attribute-management9317710 Ref: 389d9317710 Node: Generic Attribute Management9319264 Ref: extending/newtypes generic-attribute-management9319392 Ref: 38859319392 Ref: extending/newtypes id19319392 Ref: 389e9319392 Node: Type-specific Attribute Management9323650 Ref: extending/newtypes type-specific-attribute-management9323778 Ref: 38a19323778 Node: Object Comparison9325546 Ref: extending/newtypes object-comparison9325703 Ref: 38a49325703 Node: Abstract Protocol Support9327473 Ref: extending/newtypes abstract-protocol-support9327632 Ref: 38a89327632 Node: Weak Reference Support9333311 Ref: extending/newtypes weak-reference-support9333469 Ref: 38ae9333469 Ref: extending/newtypes weakref-support9333469 Ref: 163f9333469 Node: More Suggestions9335385 Ref: extending/newtypes more-suggestions9335509 Ref: 38b09335509 Node: Building C and C++ Extensions9336479 Ref: 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38be9345300 Ref: extending/windows win-cookbook9345300 Ref: 38bf9345300 Ref: A Cookbook Approach-Footnote-19345935 Node: Differences Between Unix and Windows9346012 Ref: extending/windows differences-between-unix-and-windows9346184 Ref: 38c09346184 Ref: extending/windows dynamic-linking9346184 Ref: 38c19346184 Node: Using DLLs in Practice9349107 Ref: extending/windows using-dlls-in-practice9349251 Ref: 38c29349251 Ref: extending/windows win-dlls9349251 Ref: 38c39349251 Node: Embedding the CPython runtime in a larger application9350806 Ref: extending/index embedding-the-cpython-runtime-in-a-larger-application9350996 Ref: 38c49350996 Node: Embedding Python in Another Application9351438 Ref: extending/embedding doc9351567 Ref: 38c59351567 Ref: extending/embedding embedding9351567 Ref: 38c69351567 Ref: extending/embedding embedding-python-in-another-application9351567 Ref: 38c79351567 Node: Very High Level Embedding9353910 Ref: extending/embedding high-level-embedding9354064 Ref: 38ca9354064 Ref: extending/embedding very-high-level-embedding9354064 Ref: 38cb9354064 Node: Beyond Very High Level Embedding An overview9355828 Ref: extending/embedding beyond-very-high-level-embedding-an-overview9356005 Ref: 38cc9356005 Ref: extending/embedding lower-level-embedding9356005 Ref: 38cd9356005 Node: Pure Embedding9357724 Ref: extending/embedding id19357901 Ref: 38ce9357901 Ref: extending/embedding pure-embedding9357901 Ref: 38cf9357901 Node: Extending Embedded Python9362522 Ref: extending/embedding extending-embedded-python9362678 Ref: 38d29362678 Ref: extending/embedding extending-with-embedding9362678 Ref: 38d39362678 Node: Embedding Python in C++9364658 Ref: extending/embedding embedding-python-in-c9364845 Ref: 38d49364845 Ref: extending/embedding embeddingincplusplus9364845 Ref: 38d59364845 Node: Compiling and Linking under Unix-like systems9365217 Ref: extending/embedding compiling9365370 Ref: 38d09365370 Ref: extending/embedding 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Ref: 38e39374461 Ref: c-api/intro c Py_STRINGIFY9374575 Ref: 38e49374575 Ref: c-api/intro c Py_MEMBER_SIZE9374726 Ref: 38e59374726 Ref: c-api/intro c Py_CHARMASK9374869 Ref: 38e69374869 Ref: c-api/intro c Py_GETENV9375051 Ref: 38e79375051 Ref: c-api/intro c Py_UNUSED9375234 Ref: 38e89375234 Ref: c-api/intro c Py_DEPRECATED9375456 Ref: 38e99375456 Ref: c-api/intro c PyDoc_STRVAR9375730 Ref: 38ea9375730 Ref: c-api/intro c PyDoc_STR9376311 Ref: 38eb9376311 Ref: Useful macros-Footnote-19376860 Ref: Useful macros-Footnote-29376909 Node: Objects Types and Reference Counts9376958 Ref: c-api/intro api-objects9377090 Ref: 38ec9377090 Ref: c-api/intro objects-types-and-reference-counts9377090 Ref: 38ed9377090 Node: Reference Counts<2>9378471 Ref: c-api/intro api-refcounts9378575 Ref: 38ee9378575 Ref: c-api/intro reference-counts9378575 Ref: 38ef9378575 Node: Reference Count Details9382283 Ref: c-api/intro api-refcountdetails9382362 Ref: 38f09382362 Ref: c-api/intro reference-count-details9382362 Ref: 38f19382362 Node: Types9389570 Ref: c-api/intro api-types9389674 Ref: 38f79389674 Ref: c-api/intro types9389674 Ref: 38f89389674 Node: Exceptions<18>9390152 Ref: c-api/intro api-exceptions9390290 Ref: 38f99390290 Ref: c-api/intro exceptions9390290 Ref: 38fa9390290 Node: Embedding Python<2>9396428 Ref: c-api/intro api-embedding9396548 Ref: 38fc9396548 Ref: c-api/intro embedding-python9396548 Ref: 38fd9396548 Node: Debugging Builds9399747 Ref: c-api/intro api-debugging9399844 Ref: 39029399844 Ref: c-api/intro debugging-builds9399844 Ref: 39039399844 Node: Stable Application Binary Interface9402312 Ref: c-api/stable doc9402472 Ref: 39049402472 Ref: c-api/stable stable9402472 Ref: 39059402472 Ref: c-api/stable stable-application-binary-interface9402472 Ref: 39069402472 Ref: Stable Application Binary Interface-Footnote-19404449 Node: The Very High Level Layer9404498 Ref: c-api/veryhigh doc9404660 Ref: 39079404660 Ref: c-api/veryhigh the-very-high-level-layer9404660 Ref: 39089404660 Ref: c-api/veryhigh veryhigh9404660 Ref: 39099404660 Ref: c-api/veryhigh c Py_Main9405681 Ref: 4b79405681 Ref: c-api/veryhigh c Py_BytesMain9406640 Ref: 1769406640 Ref: c-api/veryhigh c PyRun_AnyFile9406809 Ref: 390a9406809 Ref: c-api/veryhigh c PyRun_AnyFileFlags9407034 Ref: 390c9407034 Ref: c-api/veryhigh c PyRun_AnyFileEx9407276 Ref: 390d9407276 Ref: c-api/veryhigh c PyRun_AnyFileExFlags9407505 Ref: 390b9407505 Ref: c-api/veryhigh c PyRun_SimpleString9408072 Ref: 38c89408072 Ref: c-api/veryhigh c PyRun_SimpleStringFlags9408299 Ref: 390f9408299 Ref: c-api/veryhigh c PyRun_SimpleFile9408982 Ref: 38c99408982 Ref: c-api/veryhigh c PyRun_SimpleFileEx9409213 Ref: 39119409213 Ref: c-api/veryhigh c PyRun_SimpleFileExFlags9409435 Ref: 39109409435 Ref: c-api/veryhigh c PyRun_InteractiveOne9410127 Ref: 39129410127 Ref: c-api/veryhigh c PyRun_InteractiveOneFlags9410345 Ref: 39139410345 Ref: c-api/veryhigh c PyRun_InteractiveLoop9411107 Ref: 390e9411107 Ref: c-api/veryhigh c 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Ref: c-api/veryhigh c Py_CompileStringFlags9417607 Ref: 39229417607 Ref: c-api/veryhigh c Py_CompileStringObject9417901 Ref: 39249417901 Ref: c-api/veryhigh c Py_CompileStringExFlags9419018 Ref: 39239419018 Ref: c-api/veryhigh c PyEval_EvalCode9419392 Ref: 39259419392 Ref: c-api/veryhigh c PyEval_EvalCodeEx9419714 Ref: 39269419714 Ref: c-api/veryhigh c PyFrameObject9420391 Ref: 9719420391 Ref: c-api/veryhigh c PyEval_EvalFrame9420552 Ref: 39279420552 Ref: c-api/veryhigh c PyEval_EvalFrameEx9420787 Ref: 9679420787 Ref: c-api/veryhigh c PyEval_MergeCompilerFlags9421484 Ref: 39289421484 Ref: c-api/veryhigh c Py_eval_input9421676 Ref: 39299421676 Ref: c-api/veryhigh c Py_file_input9421834 Ref: 392a9421834 Ref: c-api/veryhigh c Py_single_input9422120 Ref: 392b9422120 Ref: c-api/veryhigh c PyCompilerFlags9422346 Ref: 2cc9422346 Ref: c-api/veryhigh c PyCompilerFlags cf_flags9422877 Ref: 392c9422877 Ref: c-api/veryhigh c PyCompilerFlags cf_feature_version9422937 Ref: 392d9422937 Ref: 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c-api/exceptions c PyException_GetCause9454558 Ref: 395b9454558 Ref: c-api/exceptions c PyException_SetCause9454875 Ref: 395c9454875 Node: Unicode Exception Objects9455293 Ref: c-api/exceptions unicode-exception-objects9455425 Ref: 395d9455425 Ref: c-api/exceptions unicodeexceptions9455425 Ref: 395e9455425 Ref: c-api/exceptions c PyUnicodeDecodeError_Create9455572 Ref: 395f9455572 Ref: c-api/exceptions c PyUnicodeEncodeError_Create9455995 Ref: 39609455995 Ref: c-api/exceptions c PyUnicodeTranslateError_Create9456613 Ref: 39619456613 Ref: c-api/exceptions c PyUnicodeDecodeError_GetEncoding9457191 Ref: 39629457191 Ref: c-api/exceptions c PyUnicodeEncodeError_GetEncoding9457276 Ref: 39639457276 Ref: c-api/exceptions c PyUnicodeDecodeError_GetObject9457467 Ref: 39649457467 Ref: c-api/exceptions c PyUnicodeEncodeError_GetObject9457540 Ref: 39659457540 Ref: c-api/exceptions c PyUnicodeTranslateError_GetObject9457613 Ref: 39669457613 Ref: c-api/exceptions c PyUnicodeDecodeError_GetStart9457803 Ref: 39679457803 Ref: c-api/exceptions c PyUnicodeEncodeError_GetStart9457898 Ref: 39689457898 Ref: c-api/exceptions c PyUnicodeTranslateError_GetStart9457993 Ref: 39699457993 Ref: c-api/exceptions c PyUnicodeDecodeError_SetStart9458274 Ref: 396a9458274 Ref: c-api/exceptions c PyUnicodeEncodeError_SetStart9458368 Ref: 396b9458368 Ref: c-api/exceptions c PyUnicodeTranslateError_SetStart9458462 Ref: 396c9458462 Ref: c-api/exceptions c PyUnicodeDecodeError_GetEnd9458687 Ref: 396d9458687 Ref: c-api/exceptions c PyUnicodeEncodeError_GetEnd9458778 Ref: 396e9458778 Ref: c-api/exceptions c PyUnicodeTranslateError_GetEnd9458869 Ref: 396f9458869 Ref: c-api/exceptions c PyUnicodeDecodeError_SetEnd9459140 Ref: 39709459140 Ref: c-api/exceptions c PyUnicodeEncodeError_SetEnd9459230 Ref: 39719459230 Ref: c-api/exceptions c PyUnicodeTranslateError_SetEnd9459320 Ref: 39729459320 Ref: c-api/exceptions c PyUnicodeDecodeError_GetReason9459537 Ref: 39739459537 Ref: c-api/exceptions c PyUnicodeEncodeError_GetReason9459610 Ref: 39749459610 Ref: c-api/exceptions c PyUnicodeTranslateError_GetReason9459683 Ref: 39759459683 Ref: c-api/exceptions c PyUnicodeDecodeError_SetReason9459873 Ref: 39769459873 Ref: c-api/exceptions c PyUnicodeEncodeError_SetReason9459970 Ref: 39779459970 Ref: c-api/exceptions c PyUnicodeTranslateError_SetReason9460067 Ref: 39789460067 Node: Recursion Control9460298 Ref: c-api/exceptions recursion-control9460432 Ref: 39799460432 Ref: c-api/exceptions c Py_EnterRecursiveCall9460736 Ref: 397a9460736 Ref: c-api/exceptions c Py_LeaveRecursiveCall9461482 Ref: 397c9461482 Ref: c-api/exceptions c Py_ReprEnter9462031 Ref: 397d9462031 Ref: c-api/exceptions c Py_ReprLeave9462799 Ref: 397e9462799 Node: Standard Exceptions9462990 Ref: c-api/exceptions standard-exceptions9463126 Ref: 397f9463126 Ref: c-api/exceptions standardexceptions9463126 Ref: 39809463126 Ref: Standard Exceptions-Footnote-19476505 Node: Standard Warning Categories9476554 Ref: c-api/exceptions standard-warning-categories9476664 Ref: 39819476664 Ref: c-api/exceptions standardwarningcategories9476664 Ref: 394a9476664 Node: Utilities<2>9479793 Ref: c-api/utilities doc9479929 Ref: 39829479929 Ref: c-api/utilities id19479929 Ref: 39839479929 Ref: c-api/utilities utilities9479929 Ref: 39849479929 Node: Operating System Utilities9480478 Ref: c-api/sys doc9480578 Ref: 39859480578 Ref: c-api/sys operating-system-utilities9480578 Ref: 39869480578 Ref: c-api/sys os9480578 Ref: 39879480578 Ref: c-api/sys c PyOS_FSPath9480645 Ref: 5cd9480645 Ref: c-api/sys c Py_FdIsInteractive9481191 Ref: 39889481191 Ref: c-api/sys c PyOS_BeforeFork9481674 Ref: 4329481674 Ref: c-api/sys c PyOS_AfterFork_Parent9482207 Ref: 4339482207 Ref: c-api/sys c PyOS_AfterFork_Child9482833 Ref: 2cd9482833 Ref: c-api/sys c PyOS_AfterFork9483734 Ref: 4319483734 Ref: c-api/sys c PyOS_CheckStack9484151 Ref: 397b9484151 Ref: c-api/sys c PyOS_getsig9484535 Ref: 398c9484535 Ref: c-api/sys c PyOS_setsig9484844 Ref: 398d9484844 Ref: c-api/sys c Py_DecodeLocale9485213 Ref: 43c9485213 Ref: c-api/sys c Py_EncodeLocale9487262 Ref: 43d9487262 Node: System Functions9489062 Ref: c-api/sys system-functions9489186 Ref: 39929489186 Ref: c-api/sys systemfunctions9489186 Ref: 39939489186 Ref: c-api/sys c PySys_GetObject9489485 Ref: 39949489485 Ref: c-api/sys c PySys_SetObject9489721 Ref: 39959489721 Ref: c-api/sys c PySys_ResetWarnOptions9489979 Ref: 39969489979 Ref: c-api/sys c PySys_AddWarnOption9490156 Ref: 4b39490156 Ref: c-api/sys c PySys_AddWarnOptionUnicode9490387 Ref: 4b29490387 Ref: c-api/sys c PySys_SetPath9490857 Ref: 39979490857 Ref: c-api/sys c PySys_WriteStdout9491123 Ref: 39989491123 Ref: c-api/sys c PySys_WriteStderr9491999 Ref: 39999491999 Ref: c-api/sys c PySys_FormatStdout9492169 Ref: 399a9492169 Ref: c-api/sys c PySys_FormatStderr9492441 Ref: 399c9492441 Ref: c-api/sys c PySys_AddXOption9492639 Ref: 399d9492639 Ref: c-api/sys c PySys_GetXOptions9492947 Ref: 399e9492947 Ref: c-api/sys c PySys_Audit9493227 Ref: 31eb9493227 Ref: c-api/sys c PySys_AddAuditHook9494356 Ref: 31ed9494356 Ref: System Functions-Footnote-19496207 Node: Process Control9496256 Ref: c-api/sys process-control9496374 Ref: 39a09496374 Ref: c-api/sys processcontrol9496374 Ref: 39a19496374 Ref: c-api/sys c Py_FatalError9496419 Ref: 39a29496419 Ref: c-api/sys c Py_Exit9496899 Ref: 6129496899 Ref: c-api/sys c Py_AtExit9497253 Ref: 39a39497253 Node: Importing Modules<2>9497903 Ref: c-api/import doc9498029 Ref: 39a49498029 Ref: c-api/import importing9498029 Ref: 39a59498029 Ref: c-api/import importing-modules9498029 Ref: 39a69498029 Ref: c-api/import c PyImport_ImportModule9498078 Ref: c739498078 Ref: c-api/import c PyImport_ImportModuleNoBlock9499109 Ref: 9c19499109 Ref: c-api/import c PyImport_ImportModuleEx9499597 Ref: b219499597 Ref: c-api/import c PyImport_ImportModuleLevelObject9500325 Ref: 39a79500325 Ref: c-api/import c PyImport_ImportModuleLevel9501085 Ref: b209501085 Ref: c-api/import c PyImport_Import9501507 Ref: d5f9501507 Ref: c-api/import c PyImport_ReloadModule9502028 Ref: 39a89502028 Ref: c-api/import c PyImport_AddModuleObject9502290 Ref: 39a99502290 Ref: c-api/import c PyImport_AddModule9503117 Ref: 38609503117 Ref: c-api/import c PyImport_ExecCodeModule9503353 Ref: 39aa9503353 Ref: c-api/import c PyImport_ExecCodeModuleEx9505134 Ref: 39ab9505134 Ref: c-api/import c PyImport_ExecCodeModuleObject9505522 Ref: 39ad9505522 Ref: c-api/import c PyImport_ExecCodeModuleWithPathnames9505958 Ref: 39ac9505958 Ref: c-api/import c PyImport_GetMagicNumber9506602 Ref: b1f9506602 Ref: c-api/import c PyImport_GetMagicTag9506957 Ref: 39ae9506957 Ref: c-api/import c PyImport_GetModuleDict9507266 Ref: 39af9507266 Ref: c-api/import c PyImport_GetModule9507504 Ref: 4219507504 Ref: c-api/import c PyImport_GetImporter9507853 Ref: 39b09507853 Ref: c-api/import c _PyImport_Init9508515 Ref: 39b19508515 Ref: c-api/import c PyImport_Cleanup9508618 Ref: 39b29508618 Ref: c-api/import c _PyImport_Fini9508714 Ref: 39b39508714 Ref: c-api/import c PyImport_ImportFrozenModuleObject9508815 Ref: 39b49508815 Ref: c-api/import c PyImport_ImportFrozenModule9509419 Ref: 39b59509419 Ref: c-api/import c _frozen9509626 Ref: 39b69509626 Ref: c-api/import c PyImport_FrozenModules9510038 Ref: 1fe09510038 Ref: c-api/import c PyImport_AppendInittab9510442 Ref: 38489510442 Ref: c-api/import c _inittab9510985 Ref: 39b89510985 Ref: c-api/import c PyImport_ExtendInittab9511640 Ref: 39b79511640 Ref: Importing Modules<2>-Footnote-19512260 Node: Data marshalling support9512309 Ref: c-api/marshal doc9512457 Ref: 39b99512457 Ref: c-api/marshal data-marshalling-support9512457 Ref: 39ba9512457 Ref: c-api/marshal marshalling-utils9512457 Ref: 39bb9512457 Ref: c-api/marshal c PyMarshal_WriteLongToFile9513204 Ref: 39bc9513204 Ref: c-api/marshal c PyMarshal_WriteObjectToFile9513522 Ref: 39bd9513522 Ref: c-api/marshal c PyMarshal_WriteObjectToString9513719 Ref: 39be9513719 Ref: c-api/marshal c PyMarshal_ReadLongFromFile9514046 Ref: 39bf9514046 Ref: c-api/marshal c PyMarshal_ReadShortFromFile9514403 Ref: 39c09514403 Ref: c-api/marshal c PyMarshal_ReadObjectFromFile9514762 Ref: 39c19514762 Ref: c-api/marshal c PyMarshal_ReadLastObjectFromFile9515106 Ref: 39c29515106 Ref: c-api/marshal c PyMarshal_ReadObjectFromString9515883 Ref: 39c39515883 Node: Parsing arguments and building values9516291 Ref: c-api/arg doc9516451 Ref: 39c49516451 Ref: c-api/arg arg-parsing9516451 Ref: 2d09516451 Ref: c-api/arg parsing-arguments-and-building-values9516451 Ref: 39c59516451 Node: Parsing arguments<3>9517122 Ref: c-api/arg parsing-arguments9517240 Ref: 39c79517240 Node: Strings and buffers9517970 Ref: c-api/arg strings-and-buffers9518065 Ref: 39c89518065 Node: Numbers<2>9530253 Ref: c-api/arg numbers9530370 Ref: 39ca9530370 Node: Other objects9532488 Ref: c-api/arg other-objects9532599 Ref: 39cc9532599 Ref: c-api/arg o-ampersand9533351 Ref: 39cd9533351 Node: API Functions9537893 Ref: c-api/arg api-functions9537985 Ref: 39ce9537985 Ref: c-api/arg c PyArg_ParseTuple9538030 Ref: 26a9538030 Ref: c-api/arg c PyArg_VaParse9538324 Ref: 39cf9538324 Ref: c-api/arg c PyArg_ParseTupleAndKeywords9538553 Ref: 5ca9538553 Ref: c-api/arg c PyArg_VaParseTupleAndKeywords9539154 Ref: dda9539154 Ref: c-api/arg c PyArg_ValidateKeywordArguments9539452 Ref: 39d09539452 Ref: c-api/arg c PyArg_Parse9539755 Ref: 39c69539755 Ref: c-api/arg c PyArg_UnpackTuple9540359 Ref: e469540359 Node: Building values9542290 Ref: c-api/arg building-values9542408 Ref: 39d19542408 Ref: c-api/arg c Py_BuildValue9542457 Ref: 2ce9542457 Ref: c-api/arg c Py_VaBuildValue9550009 Ref: 39d29550009 Node: String conversion and formatting9550263 Ref: c-api/conversion doc9550409 Ref: 39d39550409 Ref: c-api/conversion string-conversion9550409 Ref: 39d49550409 Ref: c-api/conversion string-conversion-and-formatting9550409 Ref: 39d59550409 Ref: c-api/conversion c PyOS_snprintf9550550 Ref: e499550550 Ref: c-api/conversion c PyOS_vsnprintf9550811 Ref: e4a9550811 Ref: c-api/conversion c PyOS_string_to_double9552523 Ref: c239552523 Ref: c-api/conversion c PyOS_double_to_string9554243 Ref: 39d69554243 Ref: c-api/conversion c PyOS_stricmp9555835 Ref: 39d79555835 Ref: c-api/conversion c PyOS_strnicmp9556043 Ref: 39d89556043 Node: Reflection9556281 Ref: c-api/reflection doc9556426 Ref: 39d99556426 Ref: c-api/reflection id19556426 Ref: 39da9556426 Ref: c-api/reflection reflection9556426 Ref: 39db9556426 Ref: c-api/reflection c PyEval_GetBuiltins9556461 Ref: 39dc9556461 Ref: c-api/reflection c PyEval_GetLocals9556705 Ref: 39dd9556705 Ref: c-api/reflection c PyEval_GetGlobals9556929 Ref: 39de9556929 Ref: c-api/reflection c PyEval_GetFrame9557155 Ref: 39df9557155 Ref: c-api/reflection c PyFrame_GetLineNumber9557352 Ref: ceb9557352 Ref: c-api/reflection c PyEval_GetFuncName9557484 Ref: 39e09557484 Ref: c-api/reflection c PyEval_GetFuncDesc9557664 Ref: 39e19557664 Node: Codec registry and support functions9558042 Ref: c-api/codec doc9558146 Ref: 39e29558146 Ref: c-api/codec codec-registry9558146 Ref: 5ee9558146 Ref: c-api/codec codec-registry-and-support-functions9558146 Ref: 39e39558146 Ref: c-api/codec c PyCodec_Register9558233 Ref: 39e49558233 Ref: c-api/codec c PyCodec_KnownEncoding9558510 Ref: 39e59558510 Ref: c-api/codec c PyCodec_Encode9558720 Ref: 39e69558720 Ref: c-api/codec c PyCodec_Decode9559201 Ref: 39e79559201 Node: Codec lookup API9559766 Ref: c-api/codec codec-lookup-api9559912 Ref: 39e89559912 Ref: c-api/codec c PyCodec_Encoder9560230 Ref: 39e99560230 Ref: c-api/codec c PyCodec_Decoder9560388 Ref: 39ea9560388 Ref: c-api/codec c PyCodec_IncrementalEncoder9560545 Ref: 39eb9560545 Ref: c-api/codec c PyCodec_IncrementalDecoder9560766 Ref: 39ec9560766 Ref: c-api/codec c PyCodec_StreamReader9560987 Ref: 39ed9560987 Ref: c-api/codec c PyCodec_StreamWriter9561223 Ref: 39ee9561223 Node: Registry API for Unicode encoding error handlers9561459 Ref: c-api/codec registry-api-for-unicode-encoding-error-handlers9561605 Ref: 39ef9561605 Ref: c-api/codec c PyCodec_RegisterError9561720 Ref: 39f09561720 Ref: c-api/codec c PyCodec_LookupError9562812 Ref: 39f19562812 Ref: c-api/codec c PyCodec_StrictErrors9563121 Ref: 39f29563121 Ref: c-api/codec c PyCodec_IgnoreErrors9563248 Ref: 39f39563248 Ref: c-api/codec c PyCodec_ReplaceErrors9563407 Ref: 39f49563407 Ref: c-api/codec c PyCodec_XMLCharRefReplaceErrors9563577 Ref: 39f59563577 Ref: c-api/codec c PyCodec_BackslashReplaceErrors9563768 Ref: 39f69563768 Ref: c-api/codec c PyCodec_NameReplaceErrors9563975 Ref: 7a89563975 Node: Abstract Objects Layer9564173 Ref: c-api/abstract doc9564313 Ref: 39f79564313 Ref: c-api/abstract abstract9564313 Ref: 38a99564313 Ref: c-api/abstract abstract-objects-layer9564313 Ref: 39f89564313 Node: Object Protocol9565024 Ref: c-api/object doc9565122 Ref: 39f99565122 Ref: c-api/object object9565122 Ref: 39fa9565122 Ref: c-api/object object-protocol9565122 Ref: 39fb9565122 Ref: c-api/object c Py_NotImplemented9565167 Ref: 39fc9565167 Ref: c-api/object c Py_RETURN_NOTIMPLEMENTED9565343 Ref: 39fd9565343 Ref: c-api/object c PyObject_Print9565554 Ref: 39fe9565554 Ref: c-api/object c PyObject_HasAttr9565929 Ref: 39ff9565929 Ref: c-api/object c PyObject_HasAttrString9566428 Ref: 3a019566428 Ref: c-api/object c PyObject_GetAttr9566990 Ref: 3a009566990 Ref: c-api/object c PyObject_GetAttrString9567323 Ref: 385b9567323 Ref: c-api/object c PyObject_GenericGetAttr9567664 Ref: 3a029567664 Ref: c-api/object c PyObject_SetAttr9568287 Ref: 3a039568287 Ref: c-api/object c PyObject_SetAttrString9568783 Ref: 3a059568783 Ref: c-api/object c PyObject_GenericSetAttr9569293 Ref: 3a079569293 Ref: c-api/object c PyObject_DelAttr9569950 Ref: 3a049569950 Ref: c-api/object c PyObject_DelAttrString9570192 Ref: 3a069570192 Ref: c-api/object c PyObject_GenericGetDict9570452 Ref: 3a089570452 Ref: c-api/object c PyObject_GenericSetDict9570728 Ref: 3a099570728 Ref: c-api/object c PyObject_RichCompare9571003 Ref: 38a69571003 Ref: c-api/object c PyObject_RichCompareBool9571632 Ref: 38a79571632 Ref: c-api/object c PyObject_Repr9572405 Ref: 9689572405 Ref: c-api/object c PyObject_ASCII9572906 Ref: 3a0a9572906 Ref: c-api/object c PyObject_Str9573390 Ref: 9699573390 Ref: c-api/object c PyObject_Bytes9573940 Ref: 3a0b9573940 Ref: c-api/object c PyObject_IsSubclass9574371 Ref: 79e9574371 Ref: c-api/object c PyObject_IsInstance9575347 Ref: 79d9575347 Ref: c-api/object c PyCallable_Check9576318 Ref: 3a0c9576318 Ref: c-api/object c PyObject_Call9576519 Ref: 38509576519 Ref: c-api/object c PyObject_CallObject9577164 Ref: 384f9577164 Ref: c-api/object c PyObject_CallFunction9577636 Ref: 2cf9577636 Ref: c-api/object c PyObject_CallMethod9578451 Ref: 3a0e9578451 Ref: c-api/object c PyObject_CallFunctionObjArgs9579330 Ref: 3a0d9579330 Ref: c-api/object c PyObject_CallMethodObjArgs9579864 Ref: 3a0f9579864 Ref: c-api/object c _PyObject_Vectorcall9580409 Ref: 3a109580409 Ref: c-api/object c PY_VECTORCALL_ARGUMENTS_OFFSET9581831 Ref: 3a139581831 Ref: c-api/object c PyVectorcall_NARGS9582460 Ref: 3a129582460 Ref: c-api/object c _PyObject_FastCallDict9582715 Ref: 3a149582715 Ref: c-api/object c PyObject_Hash9583632 Ref: 3a159583632 Ref: c-api/object c PyObject_HashNotImplemented9583973 Ref: d319583973 Ref: c-api/object c PyObject_IsTrue9584320 Ref: 3a169584320 Ref: c-api/object c PyObject_Not9584562 Ref: 3a179584562 Ref: c-api/object c PyObject_Type9584796 Ref: 3a189584796 Ref: c-api/object c PyObject_TypeCheck9585434 Ref: 38b19585434 Ref: c-api/object c PyObject_Size9585632 Ref: 3a199585632 Ref: c-api/object c PyObject_Length9585687 Ref: 3a1a9585687 Ref: c-api/object c PyObject_LengthHint9585999 Ref: 9289585999 Ref: c-api/object c PyObject_GetItem9586436 Ref: 38f59586436 Ref: c-api/object c PyObject_SetItem9586701 Ref: 38f39586701 Ref: c-api/object c PyObject_DelItem9587048 Ref: 3a1b9587048 Ref: c-api/object c PyObject_Dir9587282 Ref: 3a1c9587282 Ref: c-api/object c PyObject_GetIter9587819 Ref: 3a1d9587819 Ref: Object Protocol-Footnote-19588227 Ref: Object Protocol-Footnote-29588276 Node: Number Protocol9588325 Ref: c-api/number doc9588449 Ref: 3a1e9588449 Ref: c-api/number number9588449 Ref: 3a1f9588449 Ref: c-api/number number-protocol9588449 Ref: 3a209588449 Ref: c-api/number c PyNumber_Check9588494 Ref: 26b9588494 Ref: c-api/number c PyNumber_Add9588744 Ref: 3a219588744 Ref: c-api/number c PyNumber_Subtract9588994 Ref: 3a229588994 Ref: c-api/number c PyNumber_Multiply9589255 Ref: 3a239589255 Ref: c-api/number c PyNumber_MatrixMultiply9589515 Ref: 7ae9589515 Ref: c-api/number c PyNumber_FloorDivide9589830 Ref: 3a249589830 Ref: c-api/number c PyNumber_TrueDivide9590095 Ref: 3a259590095 Ref: c-api/number c PyNumber_Remainder9590586 Ref: 3a269590586 Ref: c-api/number c PyNumber_Divmod9590856 Ref: 3a279590856 Ref: c-api/number c PyNumber_Power9591130 Ref: 3a289591130 Ref: c-api/number c PyNumber_Negative9591593 Ref: 3a299591593 Ref: c-api/number c PyNumber_Positive9591824 Ref: 3a2a9591824 Ref: c-api/number c PyNumber_Absolute9592034 Ref: 3a2b9592034 Ref: c-api/number c PyNumber_Invert9592264 Ref: 3a2c9592264 Ref: c-api/number c PyNumber_Lshift9592501 Ref: 3a2d9592501 Ref: c-api/number c PyNumber_Rshift9592772 Ref: 3a2e9592772 Ref: c-api/number c PyNumber_And9593044 Ref: 3a2f9593044 Ref: c-api/number c PyNumber_Xor9593309 Ref: 3a309593309 Ref: c-api/number c PyNumber_Or9593582 Ref: 3a319593582 Ref: c-api/number c PyNumber_InPlaceAdd9593845 Ref: 3a329593845 Ref: c-api/number c PyNumber_InPlaceSubtract9594174 Ref: 3a339594174 Ref: c-api/number c PyNumber_InPlaceMultiply9594514 Ref: 3a349594514 Ref: c-api/number c PyNumber_InPlaceMatrixMultiply9594853 Ref: 7af9594853 Ref: c-api/number c PyNumber_InPlaceFloorDivide9595237 Ref: 3a359595237 Ref: c-api/number c PyNumber_InPlaceTrueDivide9595588 Ref: 3a369595588 Ref: c-api/number c PyNumber_InPlaceRemainder9596148 Ref: 3a379596148 Ref: c-api/number c PyNumber_InPlacePower9596487 Ref: 3a389596487 Ref: c-api/number c PyNumber_InPlaceLshift9597082 Ref: 3a399597082 Ref: c-api/number c PyNumber_InPlaceRshift9597432 Ref: 3a3a9597432 Ref: c-api/number c PyNumber_InPlaceAnd9597783 Ref: 3a3b9597783 Ref: c-api/number c PyNumber_InPlaceXor9598127 Ref: 3a3c9598127 Ref: c-api/number c PyNumber_InPlaceOr9598479 Ref: 3a3d9598479 Ref: c-api/number c PyNumber_Long9598821 Ref: 26c9598821 Ref: c-api/number c PyNumber_Float9599076 Ref: 26d9599076 Ref: c-api/number c PyNumber_Index9599331 Ref: 3a3e9599331 Ref: c-api/number c PyNumber_ToBase9599559 Ref: 3a3f9599559 Ref: c-api/number c PyNumber_AsSsize_t9600020 Ref: 3a409600020 Ref: c-api/number c PyIndex_Check9600749 Ref: 3a419600749 Node: Sequence Protocol9600977 Ref: c-api/sequence doc9601102 Ref: 3a429601102 Ref: c-api/sequence sequence9601102 Ref: 3a439601102 Ref: c-api/sequence sequence-protocol9601102 Ref: 3a449601102 Ref: c-api/sequence c PySequence_Check9601151 Ref: 3a459601151 Ref: c-api/sequence c PySequence_Size9601561 Ref: 3a469601561 Ref: c-api/sequence c PySequence_Length9601618 Ref: 3a479601618 Ref: c-api/sequence c PySequence_Concat9601831 Ref: 3a489601831 Ref: c-api/sequence c PySequence_Repeat9602097 Ref: 3a499602097 Ref: c-api/sequence c PySequence_InPlaceConcat9602389 Ref: 3a4a9602389 Ref: c-api/sequence c PySequence_InPlaceRepeat9602735 Ref: 3a4b9602735 Ref: c-api/sequence c PySequence_GetItem9603096 Ref: 38f69603096 Ref: c-api/sequence c PySequence_GetSlice9603337 Ref: 3a4c9603337 Ref: c-api/sequence c PySequence_SetItem9603639 Ref: 38f29603639 Ref: c-api/sequence c PySequence_DelItem9604138 Ref: 3a4d9604138 Ref: c-api/sequence c PySequence_SetSlice9604350 Ref: 3a4e9604350 Ref: c-api/sequence c PySequence_DelSlice9604628 Ref: 3a4f9604628 Ref: c-api/sequence c PySequence_Count9604896 Ref: 3a509604896 Ref: c-api/sequence c PySequence_Contains9605220 Ref: 3a519605220 Ref: c-api/sequence c PySequence_Index9605515 Ref: 3a529605515 Ref: c-api/sequence c PySequence_List9605770 Ref: 3a539605770 Ref: c-api/sequence c PySequence_Tuple9606085 Ref: 3a549606085 Ref: c-api/sequence c PySequence_Fast9606493 Ref: 3a559606493 Ref: c-api/sequence c PySequence_Fast_GET_SIZE9607177 Ref: 3a579607177 Ref: c-api/sequence c PySequence_Fast_GET_ITEM9607573 Ref: 3a589607573 Ref: c-api/sequence c PySequence_Fast_ITEMS9607867 Ref: 3a599607867 Ref: c-api/sequence c PySequence_ITEM9608271 Ref: 3a5a9608271 Node: Mapping Protocol9608620 Ref: c-api/mapping doc9608747 Ref: 3a5b9608747 Ref: c-api/mapping mapping9608747 Ref: 3a5c9608747 Ref: c-api/mapping mapping-protocol9608747 Ref: 3a5d9608747 Ref: c-api/mapping c PyMapping_Check9608904 Ref: 3a5e9608904 Ref: c-api/mapping c PyMapping_Size9609283 Ref: 3a5f9609283 Ref: c-api/mapping c PyMapping_Length9609339 Ref: 3a609609339 Ref: c-api/mapping c PyMapping_GetItemString9609546 Ref: 3a619609546 Ref: c-api/mapping c PyMapping_SetItemString9609877 Ref: 3a629609877 Ref: c-api/mapping c PyMapping_DelItem9610240 Ref: 3a639610240 Ref: c-api/mapping c PyMapping_DelItemString9610528 Ref: 3a649610528 Ref: c-api/mapping c PyMapping_HasKey9610781 Ref: 3a659610781 Ref: c-api/mapping c PyMapping_HasKeyString9611224 Ref: 3a669611224 Ref: c-api/mapping c PyMapping_Keys9611736 Ref: 42c9611736 Ref: c-api/mapping c PyMapping_Values9612007 Ref: 42d9612007 Ref: c-api/mapping c PyMapping_Items9612282 Ref: 42e9612282 Node: Iterator Protocol9612616 Ref: c-api/iter doc9612741 Ref: 3a679612741 Ref: c-api/iter iterator9612741 Ref: 3a689612741 Ref: c-api/iter iterator-protocol9612741 Ref: 3a699612741 Ref: c-api/iter c PyIter_Check9612856 Ref: 3a6a9612856 Ref: c-api/iter c PyIter_Next9612972 Ref: 3a6b9612972 Node: Buffer Protocol9613938 Ref: c-api/buffer doc9614066 Ref: 3a6c9614066 Ref: c-api/buffer buffer-protocol9614066 Ref: 3a6d9614066 Ref: c-api/buffer bufferobjects9614066 Ref: 12919614066 Node: Buffer structure9616588 Ref: c-api/buffer buffer-structure9616685 Ref: 3a6f9616685 Ref: c-api/buffer id19616685 Ref: 3a709616685 Ref: c-api/buffer c Py_buffer9617760 Ref: b1b9617760 Ref: c-api/buffer c Py_buffer buf9617783 Ref: 3a729617783 Ref: c-api/buffer c Py_buffer obj9618244 Ref: 3a749618244 Ref: c-api/buffer c Py_buffer len9618825 Ref: 3a779618825 Ref: c-api/buffer c Py_buffer readonly9619425 Ref: 3a7a9619425 Ref: c-api/buffer c Py_buffer itemsize9619595 Ref: 3a7b9619595 Ref: c-api/buffer c Py_buffer format9620512 Ref: 3a7c9620512 Ref: c-api/buffer c Py_buffer ndim9620839 Ref: 3a7f9620839 Ref: c-api/buffer c Py_buffer shape9621437 Ref: 3a7e9621437 Ref: c-api/buffer c Py_buffer strides9621984 Ref: 3a739621984 Ref: c-api/buffer c Py_buffer suboffsets9622504 Ref: 3a809622504 Ref: c-api/buffer c Py_buffer internal9623391 Ref: 3a829623391 Node: Buffer request types9623766 Ref: c-api/buffer buffer-request-types9623886 Ref: 3a839623886 Ref: c-api/buffer id29623886 Ref: 3a849623886 Node: request-independent fields9624494 Ref: c-api/buffer request-independent-fields9624601 Ref: 3a859624601 Node: readonly format9624869 Ref: c-api/buffer readonly-format9625009 Ref: 3a869625009 Ref: c-api/buffer c PyBUF_WRITABLE9625060 Ref: 3a799625060 Ref: c-api/buffer c PyBUF_FORMAT9625393 Ref: 3a7d9625393 Node: shape strides suboffsets9625974 Ref: c-api/buffer shape-strides-suboffsets9626107 Ref: 3a879626107 Ref: c-api/buffer c PyBUF_INDIRECT9626644 Ref: 3a889626644 Ref: c-api/buffer c PyBUF_STRIDES9626835 Ref: 3a899626835 Ref: c-api/buffer c PyBUF_ND9627017 Ref: 3a8a9627017 Ref: c-api/buffer c PyBUF_SIMPLE9627208 Ref: 3a789627208 Node: contiguity requests9627310 Ref: c-api/buffer contiguity-requests9627445 Ref: 3a8b9627445 Ref: c-api/buffer c PyBUF_C_CONTIGUOUS9628054 Ref: 3a8c9628054 Ref: c-api/buffer c PyBUF_F_CONTIGUOUS9628307 Ref: 3a8d9628307 Ref: c-api/buffer c PyBUF_ANY_CONTIGUOUS9628562 Ref: 3a8e9628562 Node: compound requests9628957 Ref: c-api/buffer compound-requests9629059 Ref: 3a8f9629059 Ref: c-api/buffer c PyBUF_FULL9629934 Ref: 3a919629934 Ref: c-api/buffer c PyBUF_FULL_RO9630264 Ref: 3a929630264 Ref: c-api/buffer c PyBUF_RECORDS9630591 Ref: 3a939630591 Ref: c-api/buffer c PyBUF_RECORDS_RO9630921 Ref: 3a949630921 Ref: c-api/buffer c PyBUF_STRIDED9631245 Ref: 3a959631245 Ref: c-api/buffer c PyBUF_STRIDED_RO9631576 Ref: 3a969631576 Ref: c-api/buffer c PyBUF_CONTIG9631900 Ref: 3a979631900 Ref: c-api/buffer c PyBUF_CONTIG_RO9632231 Ref: 3a989632231 Node: Complex arrays9632424 Ref: c-api/buffer complex-arrays9632552 Ref: 3a819632552 Node: NumPy-style shape and strides9632758 Ref: c-api/buffer numpy-style-shape-and-strides9632885 Ref: 3a999632885 Node: PIL-style shape strides and suboffsets9634765 Ref: c-api/buffer pil-style-shape-strides-and-suboffsets9634892 Ref: 3a9a9634892 Node: Buffer-related functions9636118 Ref: c-api/buffer buffer-related-functions9636217 Ref: 3a9b9636217 Ref: c-api/buffer c PyObject_CheckBuffer9636286 Ref: 3a9c9636286 Ref: c-api/buffer c PyObject_GetBuffer9636571 Ref: d259636571 Ref: c-api/buffer c PyBuffer_Release9637519 Ref: d549637519 Ref: c-api/buffer c PyBuffer_SizeFromFormat9637900 Ref: 3a9d9637900 Ref: c-api/buffer c PyBuffer_IsContiguous9638082 Ref: 3a909638082 Ref: c-api/buffer c PyBuffer_GetPointer9638421 Ref: 3a9e9638421 Ref: c-api/buffer c PyBuffer_FromContiguous9638660 Ref: 3a9f9638660 Ref: c-api/buffer c PyBuffer_ToContiguous9638968 Ref: 3aa09638968 Ref: c-api/buffer c PyBuffer_FillContiguousStrides9639378 Ref: 3aa19639378 Ref: c-api/buffer c PyBuffer_FillInfo9639766 Ref: 3a769639766 Node: Old Buffer Protocol9640743 Ref: c-api/objbuffer doc9640845 Ref: 3aa29640845 Ref: c-api/objbuffer old-buffer-protocol9640845 Ref: 3aa39640845 Ref: c-api/objbuffer c PyObject_AsCharBuffer9641607 Ref: 3aa49641607 Ref: c-api/objbuffer c PyObject_AsReadBuffer9642081 Ref: 3aa59642081 Ref: c-api/objbuffer c PyObject_CheckReadBuffer9642542 Ref: 3aa69642542 Ref: c-api/objbuffer c PyObject_AsWriteBuffer9642987 Ref: 3aa79642987 Node: Concrete Objects Layer9643419 Ref: c-api/concrete doc9643586 Ref: 3aa89643586 Ref: c-api/concrete concrete9643586 Ref: 3aa99643586 Ref: c-api/concrete concrete-objects-layer9643586 Ref: 3aaa9643586 Node: Fundamental Objects9644571 Ref: c-api/concrete fundamental9644673 Ref: 3aac9644673 Ref: c-api/concrete fundamental-objects9644673 Ref: 3aad9644673 Node: Type Objects<2>9644870 Ref: c-api/type doc9644965 Ref: 3aae9644965 Ref: c-api/type type-objects9644965 Ref: 3aaf9644965 Ref: c-api/type typeobjects9644965 Ref: 3ab09644965 Ref: c-api/type c PyTypeObject9645008 Ref: 2d69645008 Ref: c-api/type c PyType_Type9645104 Ref: 3ab19645104 Ref: c-api/type c PyType_Check9645259 Ref: 3ab29645259 Ref: c-api/type c PyType_CheckExact9645473 Ref: 3ab39645473 Ref: c-api/type c PyType_ClearCache9645666 Ref: 3ab49645666 Ref: c-api/type c PyType_GetFlags9645789 Ref: 3ab59645789 Ref: c-api/type c PyType_Modified9646283 Ref: 3ab79646283 Ref: c-api/type c PyType_HasFeature9646540 Ref: 3ab89646540 Ref: c-api/type c PyType_IS_GC9646731 Ref: 3ab99646731 Ref: c-api/type c PyType_IsSubtype9646923 Ref: 3aba9646923 Ref: c-api/type c PyType_GenericAlloc9647283 Ref: 2709647283 Ref: c-api/type c PyType_GenericNew9647627 Ref: 387d9647627 Ref: c-api/type c PyType_Ready9647919 Ref: 38829647919 Ref: c-api/type c PyType_GetSlot9648258 Ref: 9249648258 Node: Creating Heap-Allocated Types9648835 Ref: c-api/type creating-heap-allocated-types9648916 Ref: 3abb9648916 Ref: c-api/type c PyType_FromSpecWithBases9649073 Ref: 3abd9649073 Ref: c-api/type c PyType_FromSpec9649732 Ref: 2d19649732 Ref: c-api/type c PyType_Spec9649895 Ref: 3abf9649895 Ref: c-api/type c PyType_Spec PyType_Spec name9649966 Ref: 3ac09649966 Ref: c-api/type c PyType_Spec PyType_Spec basicsize9650100 Ref: 3ac19650100 Ref: c-api/type c PyType_Spec PyType_Spec itemsize9650146 Ref: 3ac29650146 Ref: c-api/type c PyType_Spec PyType_Spec flags9650346 Ref: 3ac39650346 Ref: c-api/type c PyType_Spec PyType_Spec slots9650592 Ref: 3ac49650592 Ref: c-api/type c PyType_Slot9650765 Ref: 3ac59650765 Ref: c-api/type c PyType_Slot PyType_Slot slot9650896 Ref: 3ac69650896 Ref: c-api/type c PyType_Slot PyType_Slot pfunc9652257 Ref: 3ad19652257 Node: The None Object9652436 Ref: c-api/none doc9652531 Ref: 3ad29652531 Ref: c-api/none noneobject9652531 Ref: 3ad39652531 Ref: c-api/none the-none-object9652531 Ref: 3ad49652531 Ref: c-api/none c Py_None9652850 Ref: 38449652850 Ref: c-api/none c Py_RETURN_NONE9653069 Ref: dd69653069 Node: Numeric Objects9653256 Ref: c-api/concrete numeric-objects9653383 Ref: 3ad59653383 Ref: c-api/concrete numericobjects9653383 Ref: 3ad69653383 Node: Integer Objects9653532 Ref: c-api/long doc9653623 Ref: 3ad79653623 Ref: c-api/long integer-objects9653623 Ref: 3ad89653623 Ref: c-api/long longobjects9653623 Ref: 3ad99653623 Ref: c-api/long c PyLongObject9653915 Ref: 3ada9653915 Ref: c-api/long c PyLong_Type9654025 Ref: 3adb9654025 Ref: c-api/long c PyLong_Check9654226 Ref: 3adc9654226 Ref: c-api/long c PyLong_CheckExact9654386 Ref: 3add9654386 Ref: c-api/long c PyLong_FromLong9654556 Ref: 38419654556 Ref: c-api/long c PyLong_FromUnsignedLong9655093 Ref: 3ade9655093 Ref: c-api/long c PyLong_FromSsize_t9655306 Ref: 3adf9655306 Ref: c-api/long c PyLong_FromSize_t9655508 Ref: 3ae09655508 Ref: c-api/long c PyLong_FromLongLong9655701 Ref: 3ae19655701 Ref: c-api/long c PyLong_FromUnsignedLongLong9655902 Ref: 3ae29655902 Ref: c-api/long c PyLong_FromDouble9656139 Ref: 3ae39656139 Ref: c-api/long c PyLong_FromString9656339 Ref: 3ae49656339 Ref: c-api/long c PyLong_FromUnicode9657203 Ref: 3ae59657203 Ref: c-api/long c PyLong_FromUnicodeObject9657603 Ref: 3ae69657603 Ref: c-api/long c PyLong_FromVoidPtr9657839 Ref: 3ae79657839 Ref: c-api/long c PyLong_AsLong9658087 Ref: 2699658087 Ref: c-api/long c PyLong_AsLongAndOverflow9658739 Ref: bfd9658739 Ref: c-api/long c PyLong_AsLongLong9659633 Ref: 3ae99659633 Ref: c-api/long c PyLong_AsLongLongAndOverflow9660304 Ref: bfc9660304 Ref: c-api/long c PyLong_AsSsize_t9661246 Ref: 3aea9661246 Ref: c-api/long c PyLong_AsUnsignedLong9661634 Ref: 3aeb9661634 Ref: c-api/long c PyLong_AsSize_t9662051 Ref: 3aec9662051 Ref: c-api/long c PyLong_AsUnsignedLongLong9662434 Ref: c229662434 Ref: c-api/long c PyLong_AsUnsignedLongMask9663003 Ref: 3aed9663003 Ref: c-api/long c PyLong_AsUnsignedLongLongMask9663741 Ref: 3aee9663741 Ref: c-api/long c PyLong_AsDouble9664517 Ref: 3aef9664517 Ref: c-api/long c PyLong_AsVoidPtr9664894 Ref: 3ae89664894 Node: Boolean Objects9665325 Ref: c-api/bool doc9665447 Ref: 3af09665447 Ref: c-api/bool boolean-objects9665447 Ref: 3af19665447 Ref: c-api/bool boolobjects9665447 Ref: 3af29665447 Ref: c-api/bool c PyBool_Check9665749 Ref: 3af39665749 Ref: c-api/bool c Py_False9665852 Ref: 3af49665852 Ref: c-api/bool c Py_True9666049 Ref: 3af59666049 Ref: c-api/bool c Py_RETURN_FALSE9666244 Ref: dd89666244 Ref: c-api/bool c Py_RETURN_TRUE9666367 Ref: dd79666367 Ref: c-api/bool c PyBool_FromLong9666488 Ref: 3af69666488 Node: Floating Point Objects9666677 Ref: c-api/float doc9666806 Ref: 3af79666806 Ref: c-api/float floating-point-objects9666806 Ref: 3af89666806 Ref: c-api/float floatobjects9666806 Ref: 3af99666806 Ref: c-api/float c PyFloatObject9666869 Ref: 3afa9666869 Ref: c-api/float c PyFloat_Type9666987 Ref: 3afb9666987 Ref: c-api/float c PyFloat_Check9667198 Ref: 3afc9667198 Ref: c-api/float c PyFloat_CheckExact9667361 Ref: 3afd9667361 Ref: c-api/float c PyFloat_FromString9667534 Ref: 3afe9667534 Ref: c-api/float c PyFloat_FromDouble9667743 Ref: 3aff9667743 Ref: c-api/float c PyFloat_AsDouble9667921 Ref: 26e9667921 Ref: c-api/float c PyFloat_AS_DOUBLE9668519 Ref: 3b009668519 Ref: c-api/float c PyFloat_GetInfo9668689 Ref: d579668689 Ref: c-api/float c PyFloat_GetMax9668967 Ref: d559668967 Ref: c-api/float c PyFloat_GetMin9669095 Ref: d569669095 Ref: c-api/float c PyFloat_ClearFreeList9669222 Ref: 3b019669222 Node: Complex Number Objects9669359 Ref: c-api/complex doc9669464 Ref: 3b029669464 Ref: c-api/complex complex-number-objects9669464 Ref: 3b039669464 Ref: c-api/complex complexobjects9669464 Ref: 3b049669464 Node: Complex Numbers as C Structures9669897 Ref: c-api/complex complex-numbers-as-c-structures9670029 Ref: 3b059670029 Ref: c-api/complex c Py_complex9670312 Ref: 39cb9670312 Ref: c-api/complex c _Py_c_sum9670704 Ref: 3b069670704 Ref: c-api/complex c _Py_c_diff9670880 Ref: 3b079670880 Ref: c-api/complex c _Py_c_neg9671079 Ref: 3b089671079 Ref: c-api/complex c _Py_c_prod9671254 Ref: 3b099671254 Ref: c-api/complex c _Py_c_quot9671445 Ref: 3b0a9671445 Ref: c-api/complex c _Py_c_pow9671737 Ref: 3b0b9671737 Node: Complex Numbers as Python Objects9672046 Ref: c-api/complex complex-numbers-as-python-objects9672178 Ref: 3b0c9672178 Ref: c-api/complex c PyComplexObject9672263 Ref: 3b0d9672263 Ref: c-api/complex c PyComplex_Type9672383 Ref: 3b0e9672383 Ref: c-api/complex c PyComplex_Check9672596 Ref: 3b0f9672596 Ref: c-api/complex c PyComplex_CheckExact9672765 Ref: 3b109672765 Ref: c-api/complex c PyComplex_FromCComplex9672944 Ref: 3b119672944 Ref: c-api/complex c PyComplex_FromDoubles9673133 Ref: 3b129673133 Ref: c-api/complex c PyComplex_RealAsDouble9673334 Ref: 3b139673334 Ref: c-api/complex c PyComplex_ImagAsDouble9673452 Ref: 3b149673452 Ref: c-api/complex c PyComplex_AsCComplex9673575 Ref: d589673575 Node: Sequence Objects9674232 Ref: c-api/concrete sequence-objects9674357 Ref: 3b159674357 Ref: c-api/concrete sequenceobjects9674357 Ref: 3b169674357 Node: Bytes Objects<2>9674752 Ref: c-api/bytes doc9674848 Ref: 3b179674848 Ref: c-api/bytes bytes-objects9674848 Ref: 3b189674848 Ref: c-api/bytes bytesobjects9674848 Ref: 3b199674848 Ref: c-api/bytes c PyBytesObject9675014 Ref: d1e9675014 Ref: c-api/bytes c PyBytes_Type9675123 Ref: 3b1a9675123 Ref: c-api/bytes c PyBytes_Check9675322 Ref: d1f9675322 Ref: c-api/bytes c PyBytes_CheckExact9675477 Ref: 3b1b9675477 Ref: c-api/bytes c PyBytes_FromString9675643 Ref: 3b1c9675643 Ref: c-api/bytes c PyBytes_FromStringAndSize9675922 Ref: d209675922 Ref: c-api/bytes c PyBytes_FromFormat9676265 Ref: 3b1d9676265 Ref: c-api/bytes c PyBytes_FromFormatV9680111 Ref: 3b1e9680111 Ref: c-api/bytes c PyBytes_FromObject9680342 Ref: 3b1f9680342 Ref: c-api/bytes c PyBytes_Size9680527 Ref: 3b209680527 Ref: c-api/bytes c PyBytes_GET_SIZE9680640 Ref: 3b219680640 Ref: c-api/bytes c PyBytes_AsString9680780 Ref: 3b229680780 Ref: c-api/bytes c PyBytes_AS_STRING9681393 Ref: 3b239681393 Ref: c-api/bytes c PyBytes_AsStringAndSize9681538 Ref: 3b249681538 Ref: c-api/bytes c PyBytes_Concat9682540 Ref: 3b259682540 Ref: c-api/bytes c PyBytes_ConcatAndDel9683033 Ref: 3b269683033 Ref: c-api/bytes c _PyBytes_Resize9683295 Ref: 3b279683295 Ref: Bytes Objects<2>-Footnote-19684180 Ref: Bytes Objects<2>-Footnote-29684310 Ref: Bytes Objects<2>-Footnote-39684440 Ref: Bytes Objects<2>-Footnote-49684570 Ref: Bytes Objects<2>-Footnote-59684700 Ref: Bytes Objects<2>-Footnote-69684830 Ref: Bytes Objects<2>-Footnote-79684960 Ref: Bytes Objects<2>-Footnote-89685090 Node: Byte Array Objects9685220 Ref: c-api/bytearray doc9685351 Ref: 3b289685351 Ref: c-api/bytearray byte-array-objects9685351 Ref: 3b299685351 Ref: c-api/bytearray bytearrayobjects9685351 Ref: 3b2a9685351 Ref: c-api/bytearray c PyByteArrayObject9685406 Ref: 3b2b9685406 Ref: c-api/bytearray c PyByteArray_Type9685523 Ref: 3b2c9685523 Node: Type check macros9685802 Ref: c-api/bytearray type-check-macros9685903 Ref: 3b2d9685903 Ref: c-api/bytearray c PyByteArray_Check9685956 Ref: 3b2e9685956 Ref: c-api/bytearray c PyByteArray_CheckExact9686123 Ref: 3b2f9686123 Node: Direct API functions9686301 Ref: c-api/bytearray direct-api-functions9686417 Ref: 3b309686417 Ref: c-api/bytearray c PyByteArray_FromObject9686476 Ref: d219686476 Ref: c-api/bytearray c PyByteArray_FromStringAndSize9686683 Ref: d229686683 Ref: c-api/bytearray c PyByteArray_Concat9686933 Ref: 3b319686933 Ref: c-api/bytearray c PyByteArray_Size9687122 Ref: 3b329687122 Ref: c-api/bytearray c PyByteArray_AsString9687267 Ref: 3b339687267 Ref: c-api/bytearray c PyByteArray_Resize9687501 Ref: 3b349687501 Node: Macros9687647 Ref: c-api/bytearray macros9687737 Ref: 3b359687737 Ref: c-api/bytearray c PyByteArray_AS_STRING9687838 Ref: 3b369687838 Ref: c-api/bytearray c PyByteArray_GET_SIZE9687964 Ref: 3b379687964 Node: Unicode Objects and Codecs9688090 Ref: c-api/unicode doc9688218 Ref: b1c9688218 Ref: c-api/unicode unicode-objects-and-codecs9688218 Ref: 3b389688218 Ref: c-api/unicode unicodeobjects9688218 Ref: 3b399688218 Node: Unicode Objects9688370 Ref: c-api/unicode unicode-objects9688472 Ref: 3b3a9688472 Ref: Unicode Objects-Footnote-19690153 Ref: Unicode Objects-Footnote-29690202 Node: Unicode Type9690251 Ref: c-api/unicode unicode-type9690352 Ref: 3b3b9690352 Ref: c-api/unicode c Py_UCS49690484 Ref: ad39690484 Ref: c-api/unicode c Py_UCS29690504 Ref: ad29690504 Ref: c-api/unicode c Py_UCS19690524 Ref: ad19690524 Ref: c-api/unicode c Py_UNICODE9690793 Ref: aee9690793 Ref: c-api/unicode c PyASCIIObject9691135 Ref: ad49691135 Ref: c-api/unicode c PyCompactUnicodeObject9691161 Ref: ad59691161 Ref: c-api/unicode c PyUnicodeObject9691196 Ref: 3b3c9691196 Ref: c-api/unicode c PyUnicode_Type9691505 Ref: 3b3d9691505 Ref: c-api/unicode c PyUnicode_Check9691815 Ref: 3b3e9691815 Ref: c-api/unicode c PyUnicode_CheckExact9691964 Ref: 3b3f9691964 Ref: c-api/unicode c PyUnicode_READY9692116 Ref: ad69692116 Ref: c-api/unicode c PyUnicode_GET_LENGTH9692634 Ref: acc9692634 Ref: c-api/unicode c PyUnicode_1BYTE_DATA9692881 Ref: adb9692881 Ref: c-api/unicode c PyUnicode_2BYTE_DATA9692941 Ref: adc9692941 Ref: c-api/unicode c PyUnicode_4BYTE_DATA9693001 Ref: add9693001 Ref: c-api/unicode c PyUnicode_WCHAR_KIND9693466 Ref: adf9693466 Ref: c-api/unicode c PyUnicode_1BYTE_KIND9693500 Ref: ae09693500 Ref: c-api/unicode c PyUnicode_2BYTE_KIND9693534 Ref: ae19693534 Ref: c-api/unicode c PyUnicode_4BYTE_KIND9693568 Ref: ae29693568 Ref: c-api/unicode c PyUnicode_KIND9693809 Ref: ade9693809 Ref: c-api/unicode c PyUnicode_DATA9694133 Ref: ada9694133 Ref: c-api/unicode c PyUnicode_WRITE9694356 Ref: ae59694356 Ref: c-api/unicode c PyUnicode_READ9694923 Ref: ae39694923 Ref: c-api/unicode c PyUnicode_READ_CHAR9695203 Ref: ae49695203 Ref: c-api/unicode c PyUnicode_MAX_CHAR_VALUE9695525 Ref: ae69695525 Ref: c-api/unicode c PyUnicode_ClearFreeList9695841 Ref: 3b409695841 Ref: c-api/unicode c PyUnicode_GET_SIZE9695957 Ref: af59695957 Ref: c-api/unicode c PyUnicode_GET_DATA_SIZE9696385 Ref: af79696385 Ref: c-api/unicode c PyUnicode_AS_UNICODE9696769 Ref: af19696769 Ref: c-api/unicode c PyUnicode_AS_DATA9696832 Ref: af49696832 Node: Unicode Character Properties9697903 Ref: c-api/unicode unicode-character-properties9698051 Ref: 3b419698051 Ref: c-api/unicode c Py_UNICODE_ISSPACE9698315 Ref: 3b429698315 Ref: c-api/unicode c Py_UNICODE_ISLOWER9698461 Ref: 3b439698461 Ref: c-api/unicode c Py_UNICODE_ISUPPER9698606 Ref: 3b449698606 Ref: c-api/unicode c Py_UNICODE_ISTITLE9698752 Ref: 3b459698752 Ref: c-api/unicode c Py_UNICODE_ISLINEBREAK9698897 Ref: 3b469698897 Ref: c-api/unicode c Py_UNICODE_ISDECIMAL9699046 Ref: 3b479699046 Ref: c-api/unicode c Py_UNICODE_ISDIGIT9699186 Ref: 3b489699186 Ref: c-api/unicode c Py_UNICODE_ISNUMERIC9699322 Ref: 3b499699322 Ref: c-api/unicode c Py_UNICODE_ISALPHA9699462 Ref: 3b4a9699462 Ref: c-api/unicode c Py_UNICODE_ISALNUM9699609 Ref: 3b4b9699609 Ref: c-api/unicode c Py_UNICODE_ISPRINTABLE9699758 Ref: 3b4c9699758 Ref: c-api/unicode c Py_UNICODE_TOLOWER9700429 Ref: 3b4d9700429 Ref: c-api/unicode c Py_UNICODE_TOUPPER9700631 Ref: 3b4e9700631 Ref: c-api/unicode c Py_UNICODE_TOTITLE9700833 Ref: 3b4f9700833 Ref: c-api/unicode c Py_UNICODE_TODECIMAL9701035 Ref: 3b509701035 Ref: c-api/unicode c Py_UNICODE_TODIGIT9701256 Ref: 3b519701256 Ref: c-api/unicode c Py_UNICODE_TONUMERIC9701471 Ref: 3b529701471 Ref: c-api/unicode c Py_UNICODE_IS_SURROGATE9701724 Ref: 3b539701724 Ref: c-api/unicode c Py_UNICODE_IS_HIGH_SURROGATE9701834 Ref: 3b549701834 Ref: c-api/unicode c Py_UNICODE_IS_LOW_SURROGATE9701954 Ref: 3b559701954 Ref: c-api/unicode c Py_UNICODE_JOIN_SURROGATES9702072 Ref: 3b569702072 Node: Creating and accessing Unicode strings9702297 Ref: c-api/unicode creating-and-accessing-unicode-strings9702459 Ref: 3b579702459 Ref: c-api/unicode c PyUnicode_New9702643 Ref: acd9702643 Ref: c-api/unicode c PyUnicode_FromKindAndData9703146 Ref: ad79703146 Ref: c-api/unicode c PyUnicode_FromStringAndSize9703605 Ref: 3b589703605 Ref: c-api/unicode c PyUnicode_FromString9704274 Ref: 38d19704274 Ref: c-api/unicode c PyUnicode_FromFormat9704458 Ref: 7cb9704458 Ref: c-api/unicode c PyUnicode_FromFormatV9711712 Ref: 399b9711712 Ref: c-api/unicode c PyUnicode_FromEncodedObject9711946 Ref: 3b599711946 Ref: c-api/unicode c PyUnicode_GetLength9712708 Ref: acb9712708 Ref: c-api/unicode c PyUnicode_CopyCharacters9712865 Ref: aca9712865 Ref: c-api/unicode c PyUnicode_Fill9713342 Ref: afb9713342 Ref: c-api/unicode c PyUnicode_WriteChar9713821 Ref: ad09713821 Ref: c-api/unicode c PyUnicode_ReadChar9714384 Ref: acf9714384 Ref: c-api/unicode c PyUnicode_Substring9714710 Ref: ace9714710 Ref: c-api/unicode c PyUnicode_AsUCS49715033 Ref: ad89715033 Ref: c-api/unicode c PyUnicode_AsUCS4Copy9715464 Ref: ad99715464 Ref: Creating and accessing Unicode strings-Footnote-19715845 Ref: Creating and accessing Unicode strings-Footnote-29715998 Ref: Creating and accessing Unicode strings-Footnote-39716151 Ref: Creating and accessing Unicode strings-Footnote-49716304 Ref: Creating and accessing Unicode strings-Footnote-59716457 Ref: Creating and accessing Unicode strings-Footnote-69716610 Ref: Creating and accessing Unicode strings-Footnote-79716763 Ref: Creating and accessing Unicode strings-Footnote-89716916 Ref: Creating and accessing Unicode strings-Footnote-99717069 Ref: Creating and accessing Unicode strings-Footnote-109717222 Ref: Creating and accessing Unicode strings-Footnote-119717376 Ref: Creating and accessing Unicode strings-Footnote-129717530 Ref: Creating and accessing Unicode strings-Footnote-139717684 Node: Deprecated Py_UNICODE APIs9717838 Ref: c-api/unicode deprecated-py-unicode-apis9717987 Ref: 3b5b9717987 Ref: c-api/unicode c PyUnicode_FromUnicode9718365 Ref: aef9718365 Ref: c-api/unicode c PyUnicode_AsUnicode9719411 Ref: af29719411 Ref: c-api/unicode c PyUnicode_TransformDecimalToASCII9720308 Ref: b0f9720308 Ref: c-api/unicode c PyUnicode_AsUnicodeAndSize9720861 Ref: af39720861 Ref: c-api/unicode c PyUnicode_AsUnicodeCopy9721597 Ref: af89721597 Ref: c-api/unicode c PyUnicode_GetSize9722245 Ref: af69722245 Ref: c-api/unicode c PyUnicode_FromObject9722631 Ref: 3b5d9722631 Ref: Deprecated Py_UNICODE APIs-Footnote-19723061 Node: Locale Encoding9723110 Ref: c-api/unicode locale-encoding9723241 Ref: 3b5e9723241 Ref: c-api/unicode c PyUnicode_DecodeLocaleAndSize9723375 Ref: 43e9723375 Ref: c-api/unicode c PyUnicode_DecodeLocale9724554 Ref: 3b5f9724554 Ref: c-api/unicode c PyUnicode_EncodeLocale9724832 Ref: 43f9724832 Ref: Locale Encoding-Footnote-19726026 Ref: Locale Encoding-Footnote-29726075 Node: File System Encoding9726124 Ref: c-api/unicode file-system-encoding9726244 Ref: 3b609726244 Ref: c-api/unicode c PyUnicode_FSConverter9726726 Ref: 5ce9726726 Ref: c-api/unicode c PyUnicode_FSDecoder9727440 Ref: 5cf9727440 Ref: c-api/unicode c PyUnicode_DecodeFSDefaultAndSize9728001 Ref: 39909728001 Ref: c-api/unicode c PyUnicode_DecodeFSDefault9728788 Ref: 3b619728788 Ref: c-api/unicode c PyUnicode_EncodeFSDefault9729321 Ref: 39919729321 Ref: File System Encoding-Footnote-19730250 Ref: File System Encoding-Footnote-29730299 Node: wchar_t Support9730348 Ref: c-api/unicode wchar-t-support9730444 Ref: 3b629730444 Ref: c-api/unicode c PyUnicode_FromWideChar9730550 Ref: af09730550 Ref: c-api/unicode c PyUnicode_AsWideChar9730914 Ref: 3b5c9730914 Ref: c-api/unicode c PyUnicode_AsWideCharString9731721 Ref: 4389731721 Node: Built-in Codecs9732796 Ref: c-api/unicode built-in-codecs9732933 Ref: 3b639732933 Ref: c-api/unicode builtincodecs9732933 Ref: 3b5a9732933 Node: Generic Codecs9734361 Ref: c-api/unicode generic-codecs9734448 Ref: 3b649734448 Ref: c-api/unicode c PyUnicode_Decode9734532 Ref: 3b659734532 Ref: c-api/unicode c PyUnicode_AsEncodedString9735053 Ref: 3b669735053 Ref: c-api/unicode c PyUnicode_Encode9735564 Ref: afc9735564 Node: UTF-8 Codecs9736306 Ref: c-api/unicode utf-8-codecs9736415 Ref: 3b679736415 Ref: c-api/unicode c PyUnicode_DecodeUTF89736493 Ref: 3b689736493 Ref: c-api/unicode c PyUnicode_DecodeUTF8Stateful9736793 Ref: 3b699736793 Ref: c-api/unicode c PyUnicode_AsUTF8String9737291 Ref: aff9737291 Ref: c-api/unicode c PyUnicode_AsUTF8AndSize9737583 Ref: 42a9737583 Ref: c-api/unicode c PyUnicode_AsUTF89738516 Ref: 42b9738516 Ref: c-api/unicode c PyUnicode_EncodeUTF89738790 Ref: afe9738790 Node: UTF-32 Codecs9739412 Ref: c-api/unicode utf-32-codecs9739520 Ref: 3b6a9739520 Ref: c-api/unicode c PyUnicode_DecodeUTF329739601 Ref: 3b6b9739601 Ref: c-api/unicode c PyUnicode_DecodeUTF32Stateful9740751 Ref: 3b6c9740751 Ref: c-api/unicode c PyUnicode_AsUTF32String9741373 Ref: 3b6d9741373 Ref: c-api/unicode c PyUnicode_EncodeUTF329741708 Ref: b009741708 Node: UTF-16 Codecs9742756 Ref: c-api/unicode utf-16-codecs9742864 Ref: 3b6e9742864 Ref: c-api/unicode c PyUnicode_DecodeUTF169742945 Ref: 3b6f9742945 Ref: c-api/unicode c PyUnicode_DecodeUTF16Stateful9744175 Ref: 3b709744175 Ref: c-api/unicode c PyUnicode_AsUTF16String9744806 Ref: 3b719744806 Ref: c-api/unicode c PyUnicode_EncodeUTF169745141 Ref: b019745141 Node: UTF-7 Codecs9746314 Ref: c-api/unicode utf-7-codecs9746430 Ref: 3b729746430 Ref: c-api/unicode c PyUnicode_DecodeUTF79746508 Ref: 3b739746508 Ref: c-api/unicode c PyUnicode_DecodeUTF7Stateful9746808 Ref: 3b749746808 Ref: c-api/unicode c PyUnicode_EncodeUTF79747308 Ref: afd9747308 Node: Unicode-Escape Codecs9748150 Ref: c-api/unicode unicode-escape-codecs9748278 Ref: 3b759748278 Ref: c-api/unicode c PyUnicode_DecodeUnicodeEscape9748389 Ref: 3b769748389 Ref: c-api/unicode c PyUnicode_AsUnicodeEscapeString9748707 Ref: b039748707 Ref: c-api/unicode c PyUnicode_EncodeUnicodeEscape9749027 Ref: b029749027 Node: Raw-Unicode-Escape Codecs9749548 Ref: c-api/unicode raw-unicode-escape-codecs9749678 Ref: 3b779749678 Ref: c-api/unicode c PyUnicode_DecodeRawUnicodeEscape9749801 Ref: 3b789749801 Ref: c-api/unicode c PyUnicode_AsRawUnicodeEscapeString9750126 Ref: b059750126 Ref: c-api/unicode c PyUnicode_EncodeRawUnicodeEscape9750453 Ref: b049750453 Node: Latin-1 Codecs9751038 Ref: c-api/unicode latin-1-codecs9751159 Ref: 3b799751159 Ref: c-api/unicode c PyUnicode_DecodeLatin19751356 Ref: 3b7a9751356 Ref: c-api/unicode c PyUnicode_AsLatin1String9751660 Ref: b079751660 Ref: c-api/unicode c PyUnicode_EncodeLatin19751961 Ref: b069751961 Node: ASCII Codecs9752537 Ref: c-api/unicode ascii-codecs9752653 Ref: 3b7b9752653 Ref: c-api/unicode c PyUnicode_DecodeASCII9752801 Ref: 3b7c9752801 Ref: c-api/unicode c PyUnicode_AsASCIIString9753102 Ref: b099753102 Ref: c-api/unicode c PyUnicode_EncodeASCII9753395 Ref: b089753395 Node: Character Map Codecs9753967 Ref: c-api/unicode character-map-codecs9754092 Ref: 3b7d9754092 Ref: c-api/unicode c PyUnicode_DecodeCharmap9754571 Ref: 3b7e9754571 Ref: c-api/unicode c PyUnicode_AsCharmapString9755395 Ref: 3b7f9755395 Ref: c-api/unicode c PyUnicode_EncodeCharmap9756055 Ref: b0a9756055 Ref: c-api/unicode c PyUnicode_Translate9756753 Ref: 3b809756753 Ref: c-api/unicode c PyUnicode_TranslateCharmap9757592 Ref: b0b9757592 Node: MBCS codecs for Windows9758240 Ref: c-api/unicode mbcs-codecs-for-windows9758368 Ref: 3b819758368 Ref: c-api/unicode c PyUnicode_DecodeMBCS9758728 Ref: 3b829758728 Ref: c-api/unicode c PyUnicode_DecodeMBCSStateful9759027 Ref: 3b839759027 Ref: c-api/unicode c PyUnicode_AsMBCSString9759492 Ref: b0d9759492 Ref: c-api/unicode c PyUnicode_EncodeCodePage9759783 Ref: b0e9759783 Ref: c-api/unicode c PyUnicode_EncodeMBCS9760181 Ref: b0c9760181 Node: Methods & Slots9760793 Ref: c-api/unicode methods-slots9760892 Ref: 3b849760892 Node: Methods and Slot Functions9760943 Ref: c-api/unicode methods-and-slot-functions9761056 Ref: 3b859761056 Ref: c-api/unicode unicodemethodsandslots9761056 Ref: 3b869761056 Ref: c-api/unicode c PyUnicode_Concat9761379 Ref: b1d9761379 Ref: c-api/unicode c PyUnicode_Split9761557 Ref: 3b879761557 Ref: c-api/unicode c PyUnicode_Splitlines9762022 Ref: 3b889762022 Ref: c-api/unicode c PyUnicode_Join9762372 Ref: b1e9762372 Ref: c-api/unicode c PyUnicode_Tailmatch9762599 Ref: afa9762599 Ref: c-api/unicode c PyUnicode_Find9763000 Ref: 3b899763000 Ref: c-api/unicode c PyUnicode_FindChar9763548 Ref: 4409763548 Ref: c-api/unicode c PyUnicode_Count9764227 Ref: 3b8a9764227 Ref: c-api/unicode c PyUnicode_Replace9764485 Ref: 3b8b9764485 Ref: c-api/unicode c PyUnicode_Compare9764837 Ref: af99764837 Ref: c-api/unicode c PyUnicode_CompareWithASCIIString9765159 Ref: bfe9765159 Ref: c-api/unicode c PyUnicode_RichCompare9765615 Ref: 3b8c9765615 Ref: c-api/unicode c PyUnicode_Format9766145 Ref: 3b8d9766145 Ref: c-api/unicode c PyUnicode_Contains9766371 Ref: 3b8e9766371 Ref: c-api/unicode c PyUnicode_InternInPlace9766676 Ref: 3b8f9766676 Ref: c-api/unicode c PyUnicode_InternFromString9767451 Ref: 3b909767451 Node: Tuple Objects9767834 Ref: c-api/tuple doc9767967 Ref: 3b919767967 Ref: c-api/tuple tuple-objects9767967 Ref: 3b929767967 Ref: c-api/tuple tupleobjects9767967 Ref: 3b939767967 Ref: c-api/tuple c PyTupleObject9768014 Ref: 399f9768014 Ref: c-api/tuple c PyTuple_Type9768123 Ref: 3b949768123 Ref: c-api/tuple c PyTuple_Check9768322 Ref: 3b959768322 Ref: c-api/tuple c PyTuple_CheckExact9768466 Ref: 3b969768466 Ref: c-api/tuple c PyTuple_New9768621 Ref: 3b979768621 Ref: c-api/tuple c PyTuple_Pack9768786 Ref: 3b989768786 Ref: c-api/tuple c PyTuple_Size9769144 Ref: 3b999769144 Ref: c-api/tuple c PyTuple_GET_SIZE9769279 Ref: 3b9a9769279 Ref: c-api/tuple c PyTuple_GetItem9769466 Ref: 385c9769466 Ref: c-api/tuple c PyTuple_GET_ITEM9769750 Ref: 3b9b9769750 Ref: c-api/tuple c PyTuple_GetSlice9769946 Ref: 3b9c9769946 Ref: c-api/tuple c PyTuple_SetItem9770318 Ref: 38619770318 Ref: c-api/tuple c PyTuple_SET_ITEM9770790 Ref: 3b9d9770790 Ref: c-api/tuple c _PyTuple_Resize9771274 Ref: e4b9771274 Ref: c-api/tuple c PyTuple_ClearFreeList9772190 Ref: 3b9e9772190 Node: Struct Sequence Objects9772304 Ref: c-api/tuple struct-sequence-objects9772423 Ref: 3b9f9772423 Ref: c-api/tuple c PyStructSequence_NewType9772731 Ref: 3ba09772731 Ref: c-api/tuple c PyStructSequence_InitType9773044 Ref: 9279773044 Ref: c-api/tuple c PyStructSequence_InitType29773222 Ref: 9269773222 Ref: c-api/tuple c PyStructSequence_Desc9773468 Ref: 4299773468 Ref: c-api/tuple c PyStructSequence_Field9775046 Ref: 4289775046 Ref: c-api/tuple c PyStructSequence_UnnamedField9776147 Ref: 3ba29776147 Ref: c-api/tuple c PyStructSequence_New9776258 Ref: 3ba19776258 Ref: c-api/tuple c PyStructSequence_GetItem9776479 Ref: 3ba39776479 Ref: c-api/tuple c PyStructSequence_GET_ITEM9776735 Ref: 3ba49776735 Ref: c-api/tuple c PyStructSequence_SetItem9776935 Ref: 3ba59776935 Ref: c-api/tuple c PyStructSequence_SET_ITEM9777281 Ref: 3ba69777281 Node: List Objects9777513 Ref: c-api/list doc9777610 Ref: 3ba79777610 Ref: c-api/list list-objects9777610 Ref: 3ba89777610 Ref: c-api/list listobjects9777610 Ref: 3ba99777610 Ref: c-api/list c PyListObject9777655 Ref: 3a569777655 Ref: c-api/list c PyList_Type9777762 Ref: 38919777762 Ref: c-api/list c PyList_Check9777961 Ref: 3baa9777961 Ref: c-api/list c PyList_CheckExact9778102 Ref: 3bab9778102 Ref: c-api/list c PyList_New9778254 Ref: 38f49778254 Ref: c-api/list c PyList_Size9778768 Ref: d7e9778768 Ref: c-api/list c PyList_GET_SIZE9778940 Ref: 3bac9778940 Ref: c-api/list c PyList_GetItem9779071 Ref: 385d9779071 Ref: c-api/list c PyList_GET_ITEM9779492 Ref: 3bad9779492 Ref: c-api/list c PyList_SetItem9779681 Ref: 38629779681 Ref: c-api/list c PyList_SET_ITEM9780130 Ref: 3bae9780130 Ref: c-api/list c PyList_Insert9780649 Ref: 3baf9780649 Ref: c-api/list c PyList_Append9780958 Ref: 3bb09780958 Ref: c-api/list c PyList_GetSlice9781217 Ref: 3bb19781217 Ref: c-api/list c PyList_SetSlice9781613 Ref: 3bb29781613 Ref: c-api/list c PyList_Sort9782080 Ref: 3bb39782080 Ref: c-api/list c PyList_Reverse9782267 Ref: 3bb49782267 Ref: c-api/list c PyList_AsTuple9782467 Ref: 3bb59782467 Ref: c-api/list c PyList_ClearFreeList9782667 Ref: 3bb69782667 Node: Container Objects9782806 Ref: c-api/concrete container-objects9782935 Ref: 3bb79782935 Ref: c-api/concrete mapobjects9782935 Ref: 3bb89782935 Node: Dictionary Objects9783033 Ref: c-api/dict doc9783125 Ref: 3bb99783125 Ref: c-api/dict dictionary-objects9783125 Ref: 3bba9783125 Ref: c-api/dict dictobjects9783125 Ref: 3bbb9783125 Ref: c-api/dict c PyDictObject9783180 Ref: 3bbc9783180 Ref: c-api/dict c PyDict_Type9783293 Ref: 3bbd9783293 Ref: c-api/dict c PyDict_Check9783498 Ref: 3aab9783498 Ref: c-api/dict c PyDict_CheckExact9783639 Ref: 3bbe9783639 Ref: c-api/dict c PyDict_New9783791 Ref: 3bbf9783791 Ref: c-api/dict c PyDictProxy_New9783931 Ref: 3bc09783931 Ref: c-api/dict c PyDict_Clear9784257 Ref: 3bc19784257 Ref: c-api/dict c PyDict_Contains9784365 Ref: 3bc29784365 Ref: c-api/dict c PyDict_Copy9784659 Ref: 3bc39784659 Ref: c-api/dict c PyDict_SetItem9784825 Ref: 38639784825 Ref: c-api/dict c PyDict_SetItemString9785190 Ref: 3bc49785190 Ref: c-api/dict c PyDict_DelItem9785577 Ref: 3bc59785577 Ref: c-api/dict c PyDict_DelItemString9785906 Ref: 3bc69785906 Ref: c-api/dict c PyDict_GetItem9786196 Ref: 385e9786196 Ref: c-api/dict c PyDict_GetItemWithError9786684 Ref: 3bc79786684 Ref: c-api/dict c PyDict_GetItemString9787051 Ref: 385f9787051 Ref: c-api/dict c PyDict_SetDefault9787585 Ref: 3bc89787585 Ref: c-api/dict c PyDict_Items9788175 Ref: 3bc99788175 Ref: c-api/dict c PyDict_Keys9788352 Ref: 3bca9788352 Ref: c-api/dict c PyDict_Values9788527 Ref: 3bcb9788527 Ref: c-api/dict c PyDict_Size9788710 Ref: 3bcc9788710 Ref: c-api/dict c PyDict_Next9788874 Ref: 3bcd9788874 Ref: c-api/dict c PyDict_Merge9790779 Ref: 3bce9790779 Ref: c-api/dict c PyDict_Update9791328 Ref: 3bcf9791328 Ref: c-api/dict c PyDict_MergeFromSeq29791748 Ref: 3bd09791748 Ref: c-api/dict c PyDict_ClearFreeList9792430 Ref: 3bd19792430 Node: Set Objects9792569 Ref: c-api/set doc9792661 Ref: 3bd29792661 Ref: c-api/set set-objects9792661 Ref: 3bd39792661 Ref: c-api/set setobjects9792661 Ref: 3bd49792661 Ref: c-api/set c PySetObject9793443 Ref: 3bd59793443 Ref: c-api/set c PySet_Type9794074 Ref: 3bd69794074 Ref: c-api/set c PyFrozenSet_Type9794220 Ref: 3bd79794220 Ref: c-api/set c PySet_Check9794524 Ref: 3bd89794524 Ref: c-api/set c PyFrozenSet_Check9794658 Ref: 3bd99794658 Ref: c-api/set c PyAnySet_Check9794804 Ref: 3bda9794804 Ref: c-api/set c PyAnySet_CheckExact9794974 Ref: 3bdb9794974 Ref: c-api/set c PyFrozenSet_CheckExact9795155 Ref: 3bdc9795155 Ref: c-api/set c PySet_New9795311 Ref: dab9795311 Ref: c-api/set c PyFrozenSet_New9795762 Ref: dac9795762 Ref: c-api/set c PySet_Size9796298 Ref: db09796298 Ref: c-api/set c PySet_GET_SIZE9796605 Ref: 3bdd9796605 Ref: c-api/set c PySet_Contains9796736 Ref: daf9796736 Ref: c-api/set c PySet_Add9797245 Ref: dad9797245 Ref: c-api/set c PySet_Discard9797995 Ref: dae9797995 Ref: c-api/set c PySet_Pop9798554 Ref: 3bde9798554 Ref: c-api/set c PySet_Clear9798939 Ref: 3bdf9798939 Ref: c-api/set c PySet_ClearFreeList9799033 Ref: 3be09799033 Node: Function Objects<2>9799171 Ref: c-api/concrete function-objects9799297 Ref: 3be19799297 Ref: c-api/concrete otherobjects9799297 Ref: 3be29799297 Node: Function Objects<3>9799510 Ref: c-api/function doc9799617 Ref: 3be39799617 Ref: c-api/function function-objects9799617 Ref: 3be49799617 Ref: c-api/function id19799617 Ref: 3be59799617 Ref: c-api/function c PyFunctionObject9799725 Ref: 3be69799725 Ref: c-api/function c PyFunction_Type9799797 Ref: 3be79799797 Ref: c-api/function c PyFunction_Check9800014 Ref: 3be89800014 Ref: c-api/function c PyFunction_New9800197 Ref: 3be99800197 Ref: c-api/function c PyFunction_NewWithQualName9800760 Ref: 3bea9800760 Ref: c-api/function c PyFunction_GetCode9801234 Ref: 3beb9801234 Ref: c-api/function c PyFunction_GetGlobals9801407 Ref: 3bec9801407 Ref: c-api/function c PyFunction_GetModule9801590 Ref: 3bed9801590 Ref: c-api/function c PyFunction_GetDefaults9801879 Ref: 3bee9801879 Ref: c-api/function c PyFunction_SetDefaults9802109 Ref: 3bef9802109 Ref: c-api/function c PyFunction_GetClosure9802386 Ref: 3bf09802386 Ref: c-api/function c PyFunction_SetClosure9802615 Ref: 3bf19802615 Ref: c-api/function c PyFunction_GetAnnotations9802901 Ref: 3bf29802901 Ref: c-api/function c PyFunction_SetAnnotations9803117 Ref: 3bf39803117 Node: Instance Method Objects9803397 Ref: c-api/method doc9803530 Ref: 3bf49803530 Ref: c-api/method instance-method-objects9803530 Ref: 3bf59803530 Ref: c-api/method instancemethod-objects9803530 Ref: 3bf69803530 Ref: c-api/method c PyInstanceMethod_Type9803795 Ref: 3bf79803795 Ref: c-api/method c PyInstanceMethod_Check9803983 Ref: 3bf89803983 Ref: c-api/method c PyInstanceMethod_New9804186 Ref: 3bf99804186 Ref: c-api/method c PyInstanceMethod_Function9804452 Ref: 3bfa9804452 Ref: c-api/method c PyInstanceMethod_GET_FUNCTION9804636 Ref: 3bfb9804636 Node: Method Objects<2>9804842 Ref: c-api/method id19804968 Ref: 3bfc9804968 Ref: c-api/method method-objects9804968 Ref: 3bfd9804968 Ref: c-api/method c PyMethod_Type9805194 Ref: 3bfe9805194 Ref: c-api/method c PyMethod_Check9805394 Ref: 3bff9805394 Ref: c-api/method c PyMethod_New9805571 Ref: 3c009805571 Ref: c-api/method c PyMethod_Function9805917 Ref: 3c019805917 Ref: c-api/method c PyMethod_GET_FUNCTION9806088 Ref: 3c029806088 Ref: c-api/method c PyMethod_Self9806280 Ref: 3c039806280 Ref: c-api/method c PyMethod_GET_SELF9806440 Ref: 3c049806440 Ref: c-api/method c PyMethod_ClearFreeList9806624 Ref: 3c059806624 Node: Cell Objects9806739 Ref: c-api/cell doc9806857 Ref: 3c069806857 Ref: c-api/cell cell-objects9806857 Ref: 3c079806857 Ref: c-api/cell id19806857 Ref: 3c089806857 Ref: c-api/cell c PyCellObject9807502 Ref: 3c099807502 Ref: c-api/cell c PyCell_Type9807573 Ref: 3c0a9807573 Ref: c-api/cell c PyCell_Check9807668 Ref: 3c0b9807668 Ref: c-api/cell c PyCell_New9807780 Ref: 3c0c9807780 Ref: c-api/cell c PyCell_Get9807972 Ref: 3c0d9807972 Ref: c-api/cell c PyCell_GET9808109 Ref: 3c0e9808109 Ref: c-api/cell c PyCell_Set9808326 Ref: 3c0f9808326 Ref: c-api/cell c PyCell_SET9808687 Ref: 3c109808687 Ref: c-api/code codeobjects9808949 Ref: 3c119808949 Node: Code Objects<2>9808950 Ref: c-api/code doc9809042 Ref: 3c129809042 Ref: c-api/code code-objects9809042 Ref: 3c139809042 Ref: c-api/code c PyCodeObject9809247 Ref: 3c149809247 Ref: c-api/code c PyCode_Type9809406 Ref: 3c159809406 Ref: c-api/code c PyCode_Check9809553 Ref: 3c169809553 Ref: c-api/code c PyCode_GetNumFree9809657 Ref: 3c179809657 Ref: c-api/code c PyCode_New9809766 Ref: 2729809766 Ref: c-api/code c PyCode_NewWithPosOnlyArgs9810428 Ref: 2719810428 Ref: c-api/code c PyCode_NewEmpty9810987 Ref: cea9810987 Node: Other Objects9811342 Ref: c-api/concrete other-objects9811442 Ref: 3c189811442 Node: File Objects9811848 Ref: c-api/file doc9811933 Ref: 3c199811933 Ref: c-api/file file-objects9811933 Ref: 3c1a9811933 Ref: c-api/file fileobjects9811933 Ref: 3c1b9811933 Ref: c-api/file c PyFile_FromFd9812520 Ref: 3c1c9812520 Ref: c-api/file c PyObject_AsFileDescriptor9813476 Ref: 3c1d9813476 Ref: c-api/file c PyFile_GetLine9813892 Ref: 3c1e9813892 Ref: c-api/file c PyFile_SetOpenCodeHook9814659 Ref: 1cc19814659 Ref: c-api/file c PyFile_WriteObject9815846 Ref: 3c1f9815846 Ref: c-api/file c PyFile_WriteString9816237 Ref: 3c209816237 Node: Module Objects9816444 Ref: c-api/module doc9816554 Ref: 3c219816554 Ref: c-api/module module-objects9816554 Ref: 3c229816554 Ref: c-api/module moduleobjects9816554 Ref: 3c239816554 Ref: c-api/module c PyModule_Type9816601 Ref: 3c249816601 Ref: c-api/module c PyModule_Check9816801 Ref: 3c259816801 Ref: c-api/module c PyModule_CheckExact9816934 Ref: 3c269816934 Ref: c-api/module c PyModule_NewObject9817087 Ref: 3c279817087 Ref: c-api/module c PyModule_New9817686 Ref: 3c289817686 Ref: c-api/module c PyModule_GetDict9817905 Ref: 3c299817905 Ref: c-api/module c PyModule_GetNameObject9818494 Ref: 3c2a9818494 Ref: c-api/module c PyModule_GetName9818814 Ref: 3c2b9818814 Ref: c-api/module c PyModule_GetState9818985 Ref: 3c2c9818985 Ref: c-api/module c PyModule_GetDef9819228 Ref: 3c2e9819228 Ref: c-api/module c PyModule_GetFilenameObject9819464 Ref: 3c2f9819464 Ref: c-api/module c PyModule_GetFilename9819898 Ref: 3c309819898 Node: Initializing C modules9820329 Ref: c-api/module initializing-c-modules9820424 Ref: 3c319820424 Ref: c-api/module initializing-modules9820424 Ref: 38b59820424 Ref: c-api/module c PyModuleDef9821058 Ref: 38889821058 Ref: c-api/module c PyModuleDef m_base9821280 Ref: 3c329821280 Ref: c-api/module c PyModuleDef m_name9821397 Ref: 3c339821397 Ref: c-api/module c PyModuleDef m_doc9821472 Ref: 3c349821472 Ref: c-api/module c PyModuleDef m_size9821634 Ref: 3c2d9821634 Ref: c-api/module c PyModuleDef m_methods9822578 Ref: 3c359822578 Ref: c-api/module c PyModuleDef m_slots9822793 Ref: 3c369822793 Ref: c-api/module c PyModuleDef m_reload9823170 Ref: 3c379823170 Ref: c-api/module c PyModuleDef m_traverse9823217 Ref: 3c389823217 Ref: c-api/module c PyModuleDef m_clear9823594 Ref: 3c3a9823594 Ref: c-api/module c PyModuleDef m_free9823958 Ref: 3c3b9823958 Ref: Initializing C modules-Footnote-19824488 Node: Single-phase initialization9824537 Ref: c-api/module single-phase-initialization9824658 Ref: 3c3c9824658 Ref: c-api/module c PyModule_Create9824937 Ref: 38479824937 Ref: c-api/module c PyModule_Create29825220 Ref: 3c3d9825220 Node: Multi-phase initialization9825922 Ref: c-api/module id19826087 Ref: 3c3f9826087 Ref: c-api/module multi-phase-initialization9826087 Ref: 38b69826087 Ref: c-api/module c PyModuleDef_Init9827684 Ref: 3c409827684 Ref: c-api/module c PyModuleDef_Slot9828135 Ref: 3c419828135 Ref: c-api/module c PyModuleDef_Slot slot9828165 Ref: 3c429828165 Ref: c-api/module c PyModuleDef_Slot value9828266 Ref: 3c439828266 Ref: c-api/module c Py_mod_create9828484 Ref: 3c449828484 Ref: c-api/module c create_module9828677 Ref: 3c459828677 Ref: c-api/module c Py_mod_exec9830096 Ref: 3c399830096 Ref: c-api/module c exec_module9830368 Ref: 3c469830368 Ref: Multi-phase initialization-Footnote-19830655 Ref: Multi-phase initialization-Footnote-29830704 Node: Low-level module creation functions9830753 Ref: c-api/module low-level-module-creation-functions9830908 Ref: 3c479830908 Ref: c-api/module c PyModule_FromDefAndSpec9831287 Ref: 7ab9831287 Ref: c-api/module c PyModule_FromDefAndSpec29831667 Ref: 7ac9831667 Ref: c-api/module c PyModule_ExecDef9832290 Ref: 7ad9832290 Ref: c-api/module c PyModule_SetDocString9832483 Ref: 3c489832483 Ref: c-api/module c PyModule_AddFunctions9832822 Ref: 3c499832822 Node: Support functions9833514 Ref: c-api/module support-functions9833634 Ref: 3c4a9833634 Ref: c-api/module c PyModule_AddObject9833920 Ref: 3c3e9833920 Ref: c-api/module c PyModule_AddIntConstant9834835 Ref: 3c4b9834835 Ref: c-api/module c PyModule_AddStringConstant9835132 Ref: 3c4c9835132 Ref: c-api/module c PyModule_AddIntMacro9835493 Ref: 3c4d9835493 Ref: c-api/module c PyModule_AddStringMacro9835840 Ref: d599835840 Node: Module lookup9835952 Ref: c-api/module module-lookup9836047 Ref: 3c4e9836047 Ref: c-api/module c PyState_FindModule9836466 Ref: 3c4f9836466 Ref: c-api/module c PyState_AddModule9836950 Ref: 3c509836950 Ref: c-api/module c PyState_RemoveModule9837860 Ref: 3c519837860 Node: Iterator Objects9838070 Ref: c-api/iterator doc9838186 Ref: 3c529838186 Ref: c-api/iterator id19838186 Ref: 3c539838186 Ref: c-api/iterator iterator-objects9838186 Ref: 3c549838186 Ref: c-api/iterator c PySeqIter_Type9838584 Ref: 3c559838584 Ref: c-api/iterator c PySeqIter_Check9838818 Ref: 3c579838818 Ref: c-api/iterator c PySeqIter_New9838929 Ref: 3c569838929 Ref: c-api/iterator c PyCallIter_Type9839207 Ref: 3c589839207 Ref: c-api/iterator c PyCallIter_Check9839415 Ref: 3c5a9839415 Ref: c-api/iterator c PyCallIter_New9839528 Ref: 3c599839528 Node: Descriptor Objects9839958 Ref: c-api/descriptor doc9840073 Ref: 3c5b9840073 Ref: c-api/descriptor descriptor-objects9840073 Ref: 3c5c9840073 Ref: c-api/descriptor id19840073 Ref: 3c5d9840073 Ref: c-api/descriptor c PyProperty_Type9840254 Ref: 3c5e9840254 Ref: c-api/descriptor c PyDescr_NewGetSet9840357 Ref: 3c5f9840357 Ref: c-api/descriptor c PyDescr_NewMember9840497 Ref: 3c609840497 Ref: c-api/descriptor c PyDescr_NewMethod9840635 Ref: 3c619840635 Ref: c-api/descriptor c PyDescr_NewWrapper9840773 Ref: 3c629840773 Ref: c-api/descriptor c PyDescr_NewClassMethod9840930 Ref: 3c639840930 Ref: c-api/descriptor c PyDescr_IsData9841068 Ref: 3c649841068 Ref: c-api/descriptor c PyWrapper_New9841313 Ref: 3c659841313 Node: Slice Objects9841415 Ref: c-api/slice doc9841529 Ref: 3c669841529 Ref: c-api/slice id19841529 Ref: 3c679841529 Ref: c-api/slice slice-objects9841529 Ref: 3c689841529 Ref: c-api/slice c PySlice_Type9841576 Ref: 3c699841576 Ref: c-api/slice c PySlice_Check9841725 Ref: 3c6a9841725 Ref: c-api/slice c PySlice_New9841849 Ref: 3c6b9841849 Ref: c-api/slice c PySlice_GetIndices9842349 Ref: 3c6c9842349 Ref: c-api/slice c PySlice_GetIndicesEx9843090 Ref: 4789843090 Ref: c-api/slice c PySlice_Unpack9845049 Ref: 42f9845049 Ref: c-api/slice c PySlice_AdjustIndices9845627 Ref: 4309845627 Node: Ellipsis Object9846067 Ref: c-api/slice ellipsis-object9846181 Ref: 3c6d9846181 Ref: c-api/slice c Py_Ellipsis9846232 Ref: 3c6e9846232 Ref: c-api/memoryview memoryview-objects9846492 Ref: 3a719846492 Node: MemoryView objects9846493 Ref: c-api/memoryview doc9846619 Ref: 3c6f9846619 Ref: c-api/memoryview id19846619 Ref: 3c709846619 Ref: c-api/memoryview c PyMemoryView_FromObject9846833 Ref: 3c719846833 Ref: c-api/memoryview c PyMemoryView_FromMemory9847207 Ref: ac99847207 Ref: c-api/memoryview c PyMemoryView_FromBuffer9847508 Ref: 3a759847508 Ref: c-api/memoryview c PyMemoryView_GetContiguous9847786 Ref: 3c729847786 Ref: c-api/memoryview c PyMemoryView_Check9848278 Ref: 3c739848278 Ref: c-api/memoryview c PyMemoryView_GET_BUFFER9848477 Ref: 3c749848477 Ref: c-api/memoryview c PyMemoryView_GET_BASE9848777 Ref: 3c759848777 Node: Weak Reference Objects<2>9849146 Ref: c-api/weakref doc9849268 Ref: 3c769849268 Ref: c-api/weakref weak-reference-objects9849268 Ref: 3c779849268 Ref: c-api/weakref weakrefobjects9849268 Ref: 3c789849268 Ref: c-api/weakref c PyWeakref_Check9849586 Ref: 3c799849586 Ref: c-api/weakref c PyWeakref_CheckRef9849693 Ref: 3c7a9849693 Ref: c-api/weakref c PyWeakref_CheckProxy9849787 Ref: 3c7b9849787 Ref: c-api/weakref c PyWeakref_NewRef9849879 Ref: 3c7c9849879 Ref: c-api/weakref c PyWeakref_NewProxy9850657 Ref: 3c7d9850657 Ref: c-api/weakref c PyWeakref_GetObject9851443 Ref: 3c7e9851443 Ref: c-api/weakref c PyWeakref_GET_OBJECT9851949 Ref: 3c7f9851949 Node: Capsules<2>9852167 Ref: c-api/capsule doc9852288 Ref: 3c809852288 Ref: c-api/capsule capsules9852288 Ref: 386e9852288 Ref: c-api/capsule id19852288 Ref: 3c819852288 Ref: c-api/capsule c PyCapsule9852455 Ref: c079852455 Ref: c-api/capsule c PyCapsule_Destructor9852899 Ref: 3c829852899 Ref: c-api/capsule c PyCapsule_CheckExact9853159 Ref: 3c839853159 Ref: c-api/capsule c PyCapsule_New9853276 Ref: 386c9853276 Ref: c-api/capsule c PyCapsule_GetPointer9854189 Ref: 3c849854189 Ref: c-api/capsule c PyCapsule_GetDestructor9854654 Ref: 3c859854654 Ref: c-api/capsule c PyCapsule_GetContext9855086 Ref: 3c869855086 Ref: c-api/capsule c PyCapsule_GetName9855484 Ref: 3c879855484 Ref: c-api/capsule c PyCapsule_Import9855879 Ref: 386d9855879 Ref: c-api/capsule c PyCapsule_IsValid9856559 Ref: cf09856559 Ref: c-api/capsule c PyCapsule_SetContext9857339 Ref: 3c889857339 Ref: c-api/capsule c PyCapsule_SetDestructor9857574 Ref: 3c899857574 Ref: c-api/capsule c PyCapsule_SetName9857828 Ref: 3c8a9857828 Ref: c-api/capsule c PyCapsule_SetPointer9858211 Ref: 3c8b9858211 Node: Generator Objects9858484 Ref: c-api/gen doc9858600 Ref: 3c8c9858600 Ref: c-api/gen gen-objects9858600 Ref: 3c8d9858600 Ref: c-api/gen generator-objects9858600 Ref: 3c8e9858600 Ref: c-api/gen c PyGenObject9858900 Ref: 3c919858900 Ref: c-api/gen c PyGen_Type9858975 Ref: 3c929858975 Ref: c-api/gen c PyGen_Check9859074 Ref: 3c939859074 Ref: c-api/gen c PyGen_CheckExact9859200 Ref: 3c949859200 Ref: c-api/gen c PyGen_New9859350 Ref: 3c8f9859350 Ref: c-api/gen c PyGen_NewWithQualName9859617 Ref: 3c909859617 Node: Coroutine Objects<2>9860033 Ref: c-api/coro doc9860163 Ref: 3c959860163 Ref: c-api/coro coro-objects9860163 Ref: 7cd9860163 Ref: c-api/coro coroutine-objects9860163 Ref: 3c969860163 Ref: c-api/coro c PyCoroObject9860322 Ref: 3c979860322 Ref: c-api/coro c PyCoro_Type9860398 Ref: 3c989860398 Ref: c-api/coro c PyCoro_CheckExact9860498 Ref: 3c999860498 Ref: c-api/coro c PyCoro_New9860650 Ref: 3c9a9860650 Node: Context Variables Objects9861055 Ref: c-api/contextvars doc9861187 Ref: 3c9b9861187 Ref: c-api/contextvars context-variables-objects9861187 Ref: 3c9c9861187 Ref: c-api/contextvars contextvarsobjects9861187 Ref: 33b9861187 Ref: c-api/contextvars contextvarsobjects-pointertype-change9861258 Ref: 4b99861258 Ref: c-api/contextvars c PyContext9861796 Ref: 3c9d9861796 Ref: c-api/contextvars c PyContextVar9861907 Ref: 3c9e9861907 Ref: c-api/contextvars c PyContextToken9862024 Ref: 3c9f9862024 Ref: c-api/contextvars c PyContext_Type9862126 Ref: 3ca09862126 Ref: c-api/contextvars c PyContextVar_Type9862226 Ref: 3ca19862226 Ref: c-api/contextvars c PyContextToken_Type9862338 Ref: 3ca29862338 Ref: c-api/contextvars c PyContext_CheckExact9862478 Ref: 3ca39862478 Ref: c-api/contextvars c PyContextVar_CheckExact9862664 Ref: 3ca49862664 Ref: c-api/contextvars c PyContextToken_CheckExact9862856 Ref: 3ca59862856 Ref: c-api/contextvars c PyContext_New9863090 Ref: 3ca69863090 Ref: c-api/contextvars c PyContext_Copy9863260 Ref: 3ca79863260 Ref: c-api/contextvars c PyContext_CopyCurrent9863464 Ref: 3ca89863464 Ref: c-api/contextvars c PyContext_Enter9863661 Ref: 3ca99863661 Ref: c-api/contextvars c PyContext_Exit9863834 Ref: 3caa9863834 Ref: c-api/contextvars c PyContext_ClearFreeList9864063 Ref: 3cab9864063 Ref: c-api/contextvars c PyContextVar_New9864262 Ref: 3cac9864262 Ref: c-api/contextvars c PyContextVar_Get9864660 Ref: 3cad9864660 Ref: c-api/contextvars c PyContextVar_Set9865299 Ref: 3cae9865299 Ref: c-api/contextvars c PyContextVar_Reset9865584 Ref: 3caf9865584 Ref: Context Variables Objects-Footnote-19865920 Node: DateTime Objects<2>9865963 Ref: c-api/datetime doc9866066 Ref: 3cb09866066 Ref: c-api/datetime datetime-objects9866066 Ref: 3cb19866066 Ref: c-api/datetime datetimeobjects9866066 Ref: 3cb29866066 Ref: c-api/datetime c PyDateTime_TimeZone_UTC9866629 Ref: 4369866629 Ref: c-api/datetime c PyDate_Check9866841 Ref: 3cb39866841 Ref: c-api/datetime c PyDate_CheckExact9867031 Ref: 3cb49867031 Ref: c-api/datetime c PyDateTime_Check9867184 Ref: 3cb59867184 Ref: c-api/datetime c PyDateTime_CheckExact9867386 Ref: 3cb69867386 Ref: c-api/datetime c PyTime_Check9867547 Ref: 3cb79867547 Ref: c-api/datetime c PyTime_CheckExact9867737 Ref: 3cb89867737 Ref: c-api/datetime c PyDelta_Check9867890 Ref: 3cb99867890 Ref: c-api/datetime c PyDelta_CheckExact9868083 Ref: 3cba9868083 Ref: c-api/datetime c PyTZInfo_Check9868238 Ref: 3cbb9868238 Ref: c-api/datetime c PyTZInfo_CheckExact9868434 Ref: 3cbc9868434 Ref: c-api/datetime c PyDate_FromDate9868618 Ref: 3cbd9868618 Ref: c-api/datetime c PyDateTime_FromDateAndTime9868816 Ref: 3cbe9868816 Ref: c-api/datetime c PyDateTime_FromDateAndTimeAndFold9869136 Ref: 3cbf9869136 Ref: c-api/datetime c PyTime_FromTime9869505 Ref: 3cc09869505 Ref: c-api/datetime c PyTime_FromTimeAndFold9869747 Ref: 3cc19869747 Ref: c-api/datetime c PyDelta_FromDSU9870043 Ref: 3cc29870043 Ref: c-api/datetime c PyTimeZone_FromOffset9870461 Ref: 4349870461 Ref: c-api/datetime c PyTimeZone_FromOffsetAndName9870737 Ref: 4359870737 Ref: c-api/datetime c PyDateTime_GET_YEAR9871281 Ref: 3cc39871281 Ref: c-api/datetime c PyDateTime_GET_MONTH9871385 Ref: 3cc49871385 Ref: c-api/datetime c PyDateTime_GET_DAY9871501 Ref: 3cc59871501 Ref: c-api/datetime c PyDateTime_DATE_GET_HOUR9871815 Ref: 3cc69871815 Ref: c-api/datetime c PyDateTime_DATE_GET_MINUTE9871938 Ref: 3cc79871938 Ref: c-api/datetime c PyDateTime_DATE_GET_SECOND9872065 Ref: 3cc89872065 Ref: c-api/datetime c PyDateTime_DATE_GET_MICROSECOND9872192 Ref: 3cc99872192 Ref: c-api/datetime c PyDateTime_TIME_GET_HOUR9872537 Ref: 3cca9872537 Ref: c-api/datetime c PyDateTime_TIME_GET_MINUTE9872656 Ref: 3ccb9872656 Ref: c-api/datetime c PyDateTime_TIME_GET_SECOND9872779 Ref: 3ccc9872779 Ref: c-api/datetime c PyDateTime_TIME_GET_MICROSECOND9872902 Ref: 3ccd9872902 Ref: c-api/datetime c PyDateTime_DELTA_GET_DAYS9873240 Ref: 3cce9873240 Ref: c-api/datetime c PyDateTime_DELTA_GET_SECONDS9873408 Ref: 3ccf9873408 Ref: c-api/datetime c PyDateTime_DELTA_GET_MICROSECONDS9873574 Ref: 3cd09873574 Ref: c-api/datetime c PyDateTime_FromTimestamp9873825 Ref: 3cd19873825 Ref: c-api/datetime c PyDate_FromTimestamp9874097 Ref: 3cd29874097 Node: Initialization Finalization and Threads9874357 Ref: c-api/init doc9874537 Ref: 3cd39874537 Ref: c-api/init initialization9874537 Ref: 3cd49874537 Ref: c-api/init initialization-finalization-and-threads9874537 Ref: 3cd59874537 Node: Before Python Initialization9875039 Ref: c-api/init before-python-initialization9875182 Ref: 3cd69875182 Ref: c-api/init pre-init-safe9875182 Ref: 43a9875182 Node: Global configuration variables9877184 Ref: c-api/init global-conf-vars9877379 Ref: 3cd79877379 Ref: c-api/init global-configuration-variables9877379 Ref: 3ce29877379 Ref: c-api/init c Py_BytesWarningFlag9877850 Ref: 4b49877850 Ref: c-api/init c Py_DebugFlag9878132 Ref: 3ce39878132 Ref: c-api/init c Py_DontWriteBytecodeFlag9878360 Ref: 3ce49878360 Ref: c-api/init c Py_FrozenFlag9878625 Ref: 3ce59878625 Ref: c-api/init c Py_HashRandomizationFlag9878846 Ref: 3ce69878846 Ref: c-api/init c Py_IgnoreEnvironmentFlag9879132 Ref: 4b89879132 Ref: c-api/init c Py_InspectFlag9879372 Ref: 3ce79879372 Ref: c-api/init c Py_InteractiveFlag9879741 Ref: 39899879741 Ref: c-api/init c Py_IsolatedFlag9879821 Ref: 3ce89879821 Ref: c-api/init c Py_LegacyWindowsFSEncodingFlag9880092 Ref: 398e9880092 Ref: c-api/init c Py_LegacyWindowsStdioFlag9880473 Ref: 3ce99880473 Ref: c-api/init c Py_NoSiteFlag9880854 Ref: 3cea9880854 Ref: c-api/init c Py_NoUserSiteDirectory9881229 Ref: 3ceb9881229 Ref: c-api/init c Py_OptimizeFlag9881489 Ref: 1fdf9881489 Ref: c-api/init c Py_QuietFlag9881627 Ref: 3cec9881627 Ref: c-api/init c Py_UnbufferedStdioFlag9881815 Ref: 3ced9881815 Ref: c-api/init c Py_VerboseFlag9882022 Ref: 3cee9882022 Ref: Global configuration variables-Footnote-19882510 Ref: Global configuration variables-Footnote-29882559 Node: Initializing and finalizing the interpreter9882608 Ref: c-api/init initializing-and-finalizing-the-interpreter9882798 Ref: 3cef9882798 Ref: c-api/init c Py_Initialize9882899 Ref: 4399882899 Ref: c-api/init c Py_InitializeEx9883870 Ref: 3cf09883870 Ref: c-api/init c Py_IsInitialized9884149 Ref: 39019884149 Ref: c-api/init c Py_FinalizeEx9884420 Ref: 5c99884420 Ref: c-api/init c Py_Finalize9886555 Ref: ced9886555 Node: Process-wide parameters9886707 Ref: c-api/init process-wide-parameters9886911 Ref: 3cf29886911 Ref: c-api/init c Py_SetStandardStreamEncoding9886972 Ref: 9259886972 Ref: c-api/init c Py_SetProgramName9888093 Ref: 10319888093 Ref: c-api/init c Py_GetProgramName9889007 Ref: 2769889007 Ref: c-api/init c Py_GetPrefix9889239 Ref: 38ff9889239 Ref: c-api/init c Py_GetExecPrefix9890013 Ref: 39009890013 Ref: c-api/init c Py_GetProgramFullPath9892183 Ref: 2759892183 Ref: c-api/init c Py_GetPath9892621 Ref: 38fe9892621 Ref: c-api/init c Py_SetPath9893332 Ref: 2739893332 Ref: c-api/init c Py_GetVersion9894552 Ref: 3ce09894552 Ref: c-api/init c Py_GetPlatform9895114 Ref: 3cdf9895114 Ref: c-api/init c Py_GetCopyright9895707 Ref: 3cde9895707 Ref: c-api/init c Py_GetCompiler9896090 Ref: 3cdd9896090 Ref: c-api/init c Py_GetBuildInfo9896473 Ref: d9a9896473 Ref: c-api/init c PySys_SetArgvEx9896883 Ref: bfa9896883 Ref: c-api/init c PySys_SetArgv9898860 Ref: cec9898860 Ref: c-api/init c Py_SetPythonHome9899284 Ref: 3cda9899284 Ref: c-api/init c Py_GetPythonHome9899882 Ref: 3ce19899882 Ref: Process-wide parameters-Footnote-19900165 Node: Thread State and the Global Interpreter Lock9900234 Ref: c-api/init thread-state-and-the-global-interpreter-lock9900418 Ref: 3cf39900418 Ref: c-api/init threads9900418 Ref: 3cf49900418 Node: Releasing the GIL from extension code9901961 Ref: c-api/init releasing-the-gil-from-extension-code9902114 Ref: 3cf79902114 Node: Non-Python created threads9903989 Ref: c-api/init gilstate9904170 Ref: 3cf89904170 Ref: c-api/init non-python-created-threads9904170 Ref: 3cf99904170 Node: Cautions about fork9905928 Ref: c-api/init cautions-about-fork9906086 Ref: 3cfb9906086 Ref: c-api/init fork-and-threads9906086 Ref: 398a9906086 Node: High-level API9908025 Ref: c-api/init high-level-api9908170 Ref: 3cfc9908170 Ref: c-api/init c PyInterpreterState9908344 Ref: 2c29908344 Ref: c-api/init c PyThreadState9908911 Ref: 3cf59908911 Ref: c-api/init c PyEval_InitThreads9909147 Ref: c129909147 Ref: c-api/init c PyEval_ThreadsInitialized9909847 Ref: dd99909847 Ref: c-api/init c PyEval_SaveThread9910245 Ref: c119910245 Ref: c-api/init c PyEval_RestoreThread9910558 Ref: 2b49910558 Ref: c-api/init c PyThreadState_Get9911280 Ref: 3cf69911280 Ref: c-api/init c PyThreadState_Swap9911550 Ref: 3cfd9911550 Ref: c-api/init c PyGILState_Ensure9911920 Ref: 2b69911920 Ref: c-api/init c PyGILState_Release9913649 Ref: 3cfa9913649 Ref: c-api/init c PyGILState_GetThisThreadState9914137 Ref: 3cfe9914137 Ref: c-api/init c PyGILState_Check9914526 Ref: 3cff9914526 Ref: c-api/init c Py_BEGIN_ALLOW_THREADS9915259 Ref: 38669915259 Ref: c-api/init c Py_END_ALLOW_THREADS9915565 Ref: 2b59915565 Ref: c-api/init c Py_BLOCK_THREADS9915848 Ref: 3d009915848 Ref: c-api/init c Py_UNBLOCK_THREADS9916033 Ref: 3d019916033 Node: Low-level API9916248 Ref: c-api/init low-level-api9916365 Ref: 3d029916365 Ref: c-api/init c PyInterpreterState_New9916580 Ref: 31ef9916580 Ref: c-api/init c PyInterpreterState_Clear9916921 Ref: 31ee9916921 Ref: c-api/init c PyInterpreterState_Delete9917221 Ref: 3d039917221 Ref: c-api/init c PyThreadState_New9917516 Ref: 3d049917516 Ref: c-api/init c PyThreadState_Clear9917816 Ref: 3d059917816 Ref: c-api/init c PyThreadState_Delete9917984 Ref: 3d069917984 Ref: c-api/init c PyInterpreterState_GetID9918243 Ref: 43b9918243 Ref: c-api/init c PyInterpreterState_GetDict9918492 Ref: 3d079918492 Ref: c-api/init c PyThreadState_GetDict9919001 Ref: 3d089919001 Ref: c-api/init c PyThreadState_SetAsyncExc9919502 Ref: 4379919502 Ref: c-api/init c PyEval_AcquireThread9920297 Ref: 2b39920297 Ref: c-api/init c PyEval_ReleaseThread9921404 Ref: 3d099921404 Ref: c-api/init c PyEval_AcquireLock9921973 Ref: 2b29921973 Ref: c-api/init c PyEval_ReleaseLock9923027 Ref: c109923027 Node: Sub-interpreter support9923355 Ref: c-api/init id19923542 Ref: 3d0a9923542 Ref: c-api/init sub-interpreter-support9923542 Ref: 398b9923542 Ref: c-api/init c Py_NewInterpreter9924473 Ref: 3cf19924473 Ref: c-api/init c Py_EndInterpreter9927485 Ref: 3d0d9927485 Node: Bugs and caveats9928154 Ref: c-api/init bugs-and-caveats9928230 Ref: 3d0c9928230 Node: Asynchronous Notifications9929839 Ref: c-api/init asynchronous-notifications9930003 Ref: 3d0e9930003 Ref: c-api/init c Py_AddPendingCall9930248 Ref: ce99930248 Node: Profiling and Tracing9931907 Ref: c-api/init 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PyInterpreterState_Main9938844 Ref: 3d0b9938844 Ref: c-api/init c PyInterpreterState_Next9938956 Ref: e409938956 Ref: c-api/init c PyInterpreterState_ThreadHead9939158 Ref: e419939158 Ref: c-api/init c PyThreadState_Next9939402 Ref: e429939402 Node: Thread Local Storage Support9939649 Ref: c-api/init thread-local-storage9939787 Ref: 3d1c9939787 Ref: c-api/init thread-local-storage-support9939787 Ref: 3d1d9939787 Node: Thread Specific Storage TSS API9940913 Ref: c-api/init thread-specific-storage-api9941046 Ref: 3179941046 Ref: c-api/init thread-specific-storage-tss-api9941046 Ref: 3d1e9941046 Ref: c-api/init c Py_tss_t9941436 Ref: 3189941436 Ref: c-api/init c Py_tss_NEEDS_INIT9941876 Ref: 3d1f9941876 Ref: Thread Specific Storage TSS API-Footnote-19942164 Node: Dynamic Allocation9942213 Ref: c-api/init dynamic-allocation9942318 Ref: 3d209942318 Ref: c-api/init c PyThread_tss_alloc9942599 Ref: 3d219942599 Ref: c-api/init c PyThread_tss_free9942819 Ref: 3d229942819 Node: Methods<4>9943241 Ref: c-api/init methods9943346 Ref: 3d249943346 Ref: c-api/init c PyThread_tss_is_created9943652 Ref: 3d289943652 Ref: c-api/init c PyThread_tss_create9943841 Ref: 3d279943841 Ref: c-api/init c PyThread_tss_delete9944258 Ref: 3d239944258 Ref: c-api/init c PyThread_tss_set9944690 Ref: 3d259944690 Ref: c-api/init c PyThread_tss_get9944959 Ref: 3d269944959 Node: Thread Local Storage TLS API9945196 Ref: c-api/init thread-local-storage-api9945329 Ref: 3169945329 Ref: c-api/init thread-local-storage-tls-api9945329 Ref: 3d299945329 Ref: c-api/init c PyThread_create_key9945953 Ref: 3d2a9945953 Ref: c-api/init c PyThread_delete_key9945997 Ref: 3d2b9945997 Ref: c-api/init c PyThread_set_key_value9946049 Ref: 9709946049 Ref: c-api/init c PyThread_get_key_value9946116 Ref: 3d2c9946116 Ref: c-api/init c PyThread_delete_key_value9946172 Ref: 3d2d9946172 Ref: c-api/init c PyThread_ReInitTLS9946230 Ref: 3d2e9946230 Node: Python Initialization Configuration9946274 Ref: c-api/init_config doc9946449 Ref: 3d2f9946449 Ref: c-api/init_config init-config9946449 Ref: 17d9946449 Ref: c-api/init_config python-initialization-configuration9946449 Ref: 3d309946449 Ref: Python Initialization Configuration-Footnote-19948414 Node: PyWideStringList9948463 Ref: c-api/init_config pywidestringlist9948568 Ref: 3d329948568 Ref: c-api/init_config c PyWideStringList9948617 Ref: 1629948617 Ref: c-api/init_config c PyWideStringList_Append9948807 Ref: 1749948807 Ref: c-api/init_config c PyWideStringList_Insert9949023 Ref: 1759949023 Ref: c-api/init_config c PyWideStringList length9949464 Ref: 3d339949464 Ref: c-api/init_config c PyWideStringList items9949526 Ref: 3d349949526 Node: PyStatus9949585 Ref: c-api/init_config pystatus9949710 Ref: 3d359949710 Ref: c-api/init_config c PyStatus9949743 Ref: 1619949743 Ref: c-api/init_config c PyStatus exitcode9949961 Ref: 3d369949961 Ref: c-api/init_config c PyStatus err_msg9950050 Ref: 3d379950050 Ref: c-api/init_config c PyStatus func9950116 Ref: 3d389950116 Ref: c-api/init_config c PyStatus_Ok9950264 Ref: 1739950264 Ref: c-api/init_config c PyStatus_Error9950334 Ref: 16d9950334 Ref: c-api/init_config c PyStatus_NoMemory9950450 Ref: 1729950450 Ref: c-api/init_config c PyStatus_Exit9950560 Ref: 16f9950560 Ref: c-api/init_config c PyStatus_Exception9950709 Ref: 16e9950709 Ref: c-api/init_config c PyStatus_IsError9950940 Ref: 1709950940 Ref: c-api/init_config c PyStatus_IsExit9951036 Ref: 1719951036 Ref: c-api/init_config c Py_ExitStatusException9951130 Ref: 1779951130 Node: PyPreConfig9952071 Ref: c-api/init_config pypreconfig9952214 Ref: 3d399952214 Ref: c-api/init_config c PyPreConfig9952253 Ref: 1609952253 Ref: c-api/init_config c PyPreConfig_InitPythonConfig9952487 Ref: 16c9952487 Ref: c-api/init_config c PyPreConfig_InitIsolatedConfig9952675 Ref: 16b9952675 Ref: c-api/init_config c PyPreConfig allocator9952891 Ref: 3d3c9952891 Ref: c-api/init_config c PyPreConfig configure_locale9953988 Ref: 3d3e9953988 Ref: c-api/init_config c PyPreConfig 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c-api/init_config c PyConfig9958072 Ref: 15f9958072 Ref: c-api/init_config c PyConfig_InitPythonConfig9958183 Ref: 1659958183 Ref: c-api/init_config c PyConfig_InitIsolatedConfig9958340 Ref: 1649958340 Ref: c-api/init_config c PyConfig_SetString9958501 Ref: 16a9958501 Ref: c-api/init_config c PyConfig_SetBytesString9958749 Ref: 1699958749 Ref: c-api/init_config c PyConfig_SetArgv9959034 Ref: 1679959034 Ref: c-api/init_config c PyConfig_SetBytesArgv9959259 Ref: 1689959259 Ref: c-api/init_config c PyConfig_SetWideStringList9959517 Ref: 3d319959517 Ref: c-api/init_config c PyConfig_Read9959799 Ref: 1669959799 Ref: c-api/init_config c PyConfig_Clear9960016 Ref: 1639960016 Ref: c-api/init_config c PyConfig argv9961062 Ref: 3d4d9961062 Ref: c-api/init_config c PyConfig base_exec_prefix9961453 Ref: 3d4e9961453 Ref: c-api/init_config c PyConfig base_executable9961544 Ref: 3d4f9961544 Ref: c-api/init_config c PyConfig base_prefix9961736 Ref: 3d519961736 Ref: c-api/init_config c PyConfig 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PyConfig import_time9964167 Ref: 3d5e9964167 Ref: c-api/init_config c PyConfig inspect9964248 Ref: 3d5f9964248 Ref: c-api/init_config c PyConfig install_signal_handlers9964353 Ref: 3d609964353 Ref: c-api/init_config c PyConfig interactive9964437 Ref: 3d619964437 Ref: c-api/init_config c PyConfig isolated9964502 Ref: 3d449964502 Ref: c-api/init_config c PyConfig legacy_windows_stdio9965046 Ref: 3d639965046 Ref: c-api/init_config c PyConfig malloc_stats9965392 Ref: 3d649965392 Ref: c-api/init_config c PyConfig pythonpath_env9965630 Ref: 3d659965630 Ref: c-api/init_config c PyConfig module_search_paths9965877 Ref: 3d669965877 Ref: c-api/init_config c PyConfig module_search_paths_set9965934 Ref: 3d679965934 Ref: c-api/init_config c PyConfig optimization_level9966215 Ref: 3d699966215 Ref: c-api/init_config c PyConfig parse_argv9966491 Ref: 3d4c9966491 Ref: c-api/init_config c PyConfig parser_debug9966740 Ref: 3d6a9966740 Ref: c-api/init_config c PyConfig pathconfig_warnings9966896 Ref: 3d6b9966896 Ref: c-api/init_config c PyConfig prefix9967156 Ref: 3d6c9967156 Ref: c-api/init_config c PyConfig program_name9967227 Ref: 3d6d9967227 Ref: c-api/init_config c PyConfig pycache_prefix9967377 Ref: 3d6e9967377 Ref: c-api/init_config c PyConfig quiet9967568 Ref: 3d6f9967568 Ref: c-api/init_config c PyConfig run_command9967717 Ref: 3d709967717 Ref: c-api/init_config c PyConfig run_filename9967848 Ref: 3d719967848 Ref: c-api/init_config c PyConfig run_module9967968 Ref: 3d729967968 Ref: c-api/init_config c PyConfig show_alloc_count9968097 Ref: 3d739968097 Ref: c-api/init_config c PyConfig show_ref_count9968333 Ref: 3d749968333 Ref: c-api/init_config c PyConfig site_import9968585 Ref: 3d759968585 Ref: c-api/init_config c PyConfig skip_source_first_line9968678 Ref: 3d769968678 Ref: c-api/init_config c PyConfig stdio_encoding9968771 Ref: 3d779968771 Ref: c-api/init_config c PyConfig stdio_errors9968815 Ref: 3d789968815 Ref: c-api/init_config c PyConfig tracemalloc9968982 Ref: 3d799968982 Ref: c-api/init_config c PyConfig use_environment9969091 Ref: 3d489969091 Ref: c-api/init_config c PyConfig user_site_directory9969199 Ref: 3d629969199 Ref: c-api/init_config c PyConfig verbose9969315 Ref: 3d7a9969315 Ref: c-api/init_config c PyConfig warnoptions9969392 Ref: 3d7b9969392 Ref: c-api/init_config c PyConfig write_bytecode9969867 Ref: 3d7c9969867 Ref: c-api/init_config c PyConfig xoptions9970080 Ref: 3d7d9970080 Ref: PyConfig-Footnote-19970506 Node: Initialization with PyConfig9970555 Ref: c-api/init_config initialization-with-pyconfig9970703 Ref: 3d7e9970703 Ref: c-api/init_config c Py_InitializeFromConfig9970808 Ref: 1789970808 Node: Isolated Configuration9973522 Ref: c-api/init_config init-isolated-conf9973682 Ref: 3d3b9973682 Ref: c-api/init_config isolated-configuration9973682 Ref: 3d7f9973682 Node: Python Configuration9974477 Ref: c-api/init_config init-python-config9974627 Ref: 3d3a9974627 Ref: c-api/init_config python-configuration9974627 Ref: 3d809974627 Ref: Python Configuration-Footnote-19976203 Ref: Python Configuration-Footnote-29976252 Node: Path Configuration9976301 Ref: c-api/init_config init-path-config9976439 Ref: 3d689976439 Ref: c-api/init_config path-configuration9976439 Ref: 3d819976439 Node: Py_RunMain9979871 Ref: c-api/init_config py-runmain9980039 Ref: 3d829980039 Ref: c-api/init_config c Py_RunMain9980082 Ref: 17c9980082 Node: Multi-Phase Initialization Private Provisional API9980676 Ref: c-api/init_config multi-phase-initialization-private-provisional-api9980817 Ref: 3d839980817 Ref: c-api/init_config c _Py_InitializeMain9982014 Ref: 3d849982014 Ref: Multi-Phase Initialization Private Provisional API-Footnote-19984033 Ref: Multi-Phase Initialization Private Provisional API-Footnote-29984082 Node: Memory Management9984131 Ref: c-api/memory doc9984296 Ref: 3d859984296 Ref: c-api/memory memory9984296 Ref: 3d3d9984296 Ref: c-api/memory memory-management9984296 Ref: 3d869984296 Node: Overview<3>9984583 Ref: c-api/memory memoryoverview9984677 Ref: 3d879984677 Ref: c-api/memory overview9984677 Ref: 3d889984677 Node: Raw Memory Interface9988592 Ref: c-api/memory raw-memory-interface9988711 Ref: 3d899988711 Ref: c-api/memory c PyMem_RawMalloc9989151 Ref: 96d9989151 Ref: c-api/memory c PyMem_RawCalloc9989539 Ref: 7a59989539 Ref: c-api/memory c PyMem_RawRealloc9990040 Ref: 96e9990040 Ref: c-api/memory c PyMem_RawFree9990789 Ref: 398f9990789 Node: Memory Interface9991195 Ref: c-api/memory memory-interface9991320 Ref: 3d8a9991320 Ref: c-api/memory memoryinterface9991320 Ref: 3d8b9991320 Ref: c-api/memory c PyMem_Malloc9991825 Ref: 5059991825 Ref: c-api/memory c PyMem_Calloc9992207 Ref: 7a69992207 Ref: c-api/memory c PyMem_Realloc9992702 Ref: 96f9992702 Ref: c-api/memory c PyMem_Free9993433 Ref: da99993433 Ref: c-api/memory c PyMem_New9993931 Ref: 3d8c9993931 Ref: c-api/memory c PyMem_Resize9994182 Ref: 3d8d9994182 Ref: c-api/memory c PyMem_Del9994650 Ref: 3d8e9994650 Node: Object allocators9995226 Ref: c-api/memory object-allocators9995356 Ref: 3d8f9995356 Ref: c-api/memory c PyObject_Malloc9995766 Ref: 5089995766 Ref: c-api/memory c PyObject_Calloc9996154 Ref: 7a79996154 Ref: c-api/memory c PyObject_Realloc9996655 Ref: daa9996655 Ref: c-api/memory c PyObject_Free9997404 Ref: 5049997404 Node: Default Memory Allocators9997810 Ref: c-api/memory default-memory-allocators9997951 Ref: ff89997951 Ref: c-api/memory id19997951 Ref: 3d909997951 Node: Customize Memory Allocators10000247 Ref: c-api/memory customize-memory-allocators10000393 Ref: 3d9110000393 Ref: c-api/memory c PyMemAllocatorEx10000485 Ref: 7ca10000485 Ref: c-api/memory c PyMemAllocatorDomain10002305 Ref: 3d9210002305 Ref: c-api/memory c PYMEM_DOMAIN_RAW10002398 Ref: ff910002398 Ref: c-api/memory c PYMEM_DOMAIN_MEM10002640 Ref: 50910002640 Ref: c-api/memory c PYMEM_DOMAIN_OBJ10002869 Ref: 50710002869 Ref: c-api/memory c PyMem_GetAllocator10003110 Ref: 3cdb10003110 Ref: c-api/memory c PyMem_SetAllocator10003282 Ref: 3cd810003282 Ref: c-api/memory c PyMem_SetupDebugHooks10003928 Ref: 50a10003928 Node: The pymalloc allocator10006063 Ref: c-api/memory pymalloc10006201 Ref: 5c110006201 Ref: c-api/memory the-pymalloc-allocator10006201 Ref: 3d9310006201 Node: Customize pymalloc Arena Allocator10007036 Ref: c-api/memory customize-pymalloc-arena-allocator10007129 Ref: 3d9410007129 Ref: c-api/memory c PyObjectArenaAllocator10007239 Ref: 3d9510007239 Ref: c-api/memory c PyObject_GetArenaAllocator10008243 Ref: 3cdc10008243 Ref: c-api/memory c PyObject_SetArenaAllocator10008369 Ref: 3cd910008369 Node: tracemalloc C API10008495 Ref: c-api/memory tracemalloc-c-api10008618 Ref: 3d9610008618 Ref: c-api/memory c PyTraceMalloc_Track10008690 Ref: 42410008690 Ref: c-api/memory c PyTraceMalloc_Untrack10009103 Ref: 42510009103 Node: Examples<34>10009395 Ref: c-api/memory examples10009487 Ref: 3d9710009487 Ref: c-api/memory memoryexamples10009487 Ref: 3d9810009487 Node: Object Implementation Support10011400 Ref: c-api/objimpl doc10011552 Ref: 3d9910011552 Ref: c-api/objimpl newtypes10011552 Ref: 3d9a10011552 Ref: c-api/objimpl object-implementation-support10011552 Ref: 3d9b10011552 Node: Allocating Objects on the Heap10012061 Ref: c-api/allocation doc10012190 Ref: 3d9c10012190 Ref: c-api/allocation allocating-objects10012190 Ref: 3d9d10012190 Ref: c-api/allocation allocating-objects-on-the-heap10012190 Ref: 3d9e10012190 Ref: c-api/allocation c _PyObject_New10012267 Ref: 3d9f10012267 Ref: c-api/allocation c _PyObject_NewVar10012365 Ref: 3da010012365 Ref: c-api/allocation c PyObject_Init10012496 Ref: 26f10012496 Ref: c-api/allocation c PyObject_InitVar10012945 Ref: 3da110012945 Ref: c-api/allocation c PyObject_New10013236 Ref: 2d210013236 Ref: c-api/allocation c PyObject_NewVar10013681 Ref: 2d310013681 Ref: c-api/allocation c PyObject_Del10014408 Ref: e1610014408 Ref: c-api/allocation c _Py_NoneStruct10014799 Ref: 3da210014799 Node: Common Object Structures10015117 Ref: c-api/structures doc10015270 Ref: 3da310015270 Ref: c-api/structures common-object-structures10015270 Ref: 3da410015270 Ref: c-api/structures common-structs10015270 Ref: 3da510015270 Ref: c-api/structures c PyObject10015861 Ref: 4ba10015861 Ref: c-api/structures c PyVarObject10016445 Ref: 3da610016445 Ref: c-api/structures c PyObject_HEAD10016825 Ref: c7210016825 Ref: c-api/structures c PyObject_VAR_HEAD10017086 Ref: 3da810017086 Ref: c-api/structures c Py_TYPE10017389 Ref: 387610017389 Ref: c-api/structures c Py_REFCNT10017555 Ref: 387510017555 Ref: c-api/structures c Py_SIZE10017727 Ref: 3da710017727 Ref: c-api/structures c PyObject_HEAD_INIT10017896 Ref: 3da910017896 Ref: c-api/structures c PyVarObject_HEAD_INIT10018114 Ref: 3daa10018114 Ref: c-api/structures c PyCFunction10018391 Ref: ddb10018391 Ref: c-api/structures c PyCFunctionWithKeywords10018830 Ref: 3dab10018830 Ref: c-api/structures c _PyCFunctionFast10018991 Ref: 3dac10018991 Ref: c-api/structures c _PyCFunctionFastWithKeywords10019136 Ref: 3dae10019136 Ref: c-api/structures c PyMethodDef10019303 Ref: e1b10019303 Ref: c-api/structures METH_VARARGS10021255 Ref: e4810021255 Ref: c-api/structures METH_FASTCALL10022184 Ref: 3dad10022184 Ref: c-api/structures METH_NOARGS10023288 Ref: e1810023288 Ref: c-api/structures METH_O10023687 Ref: e4710023687 Ref: c-api/structures METH_CLASS10024276 Ref: e1910024276 Ref: c-api/structures METH_STATIC10024549 Ref: e1a10024549 Ref: c-api/structures METH_COEXIST10024934 Ref: 3daf10024934 Ref: c-api/structures c PyMemberDef10025600 Ref: 42610025600 Ref: c-api/structures c PyGetSetDef10029724 Ref: 42710029724 Node: Type Objects<3>10031858 Ref: c-api/typeobj doc10032005 Ref: 3db010032005 Ref: c-api/typeobj type-objects10032005 Ref: 3db110032005 Ref: c-api/typeobj type-structs10032005 Ref: 387710032005 Node: Quick Reference10033234 Ref: c-api/typeobj quick-reference10033333 Ref: 3db310033333 Node: “tp slots”10033445 Ref: c-api/typeobj tp-slots10033529 Ref: 3db410033529 Ref: c-api/typeobj tp-slots-table10033529 Ref: 3db510033529 Ref: “tp slots”-Footnote-110046725 Ref: “tp slots”-Footnote-210046994 Node: sub-slots10047783 Ref: c-api/typeobj id310047889 Ref: 3ddc10047889 Ref: c-api/typeobj sub-slots10047889 Ref: 3dbb10047889 Node: slot typedefs10058074 Ref: c-api/typeobj slot-typedefs10058157 Ref: 3e1610058157 Ref: c-api/typeobj slot-typedefs-table10058157 Ref: 3db610058157 Node: PyTypeObject Definition10065957 Ref: c-api/typeobj pytypeobject-definition10066079 Ref: 3e1910066079 Node: PyObject Slots10068904 Ref: c-api/typeobj pyobject-slots10069028 Ref: 3e1a10069028 Ref: c-api/typeobj c PyObject _ob_next10069450 Ref: 3e1b10069450 Ref: c-api/typeobj c PyObject _ob_prev10069492 Ref: 3e1c10069492 Ref: c-api/typeobj c PyObject ob_refcnt10070242 Ref: 3e1d10070242 Ref: c-api/typeobj c PyObject ob_type10070735 Ref: 3e1e10070735 Node: PyVarObject Slots10071822 Ref: c-api/typeobj pyvarobject-slots10071941 Ref: 3e1f10071941 Ref: c-api/typeobj c PyVarObject ob_size10071996 Ref: 3e2010071996 Node: PyTypeObject Slots10072285 Ref: c-api/typeobj pytypeobject-slots10072400 Ref: 3e2110072400 Ref: c-api/typeobj c PyTypeObject tp_name10072753 Ref: 389b10072753 Ref: c-api/typeobj c PyTypeObject tp_basicsize10074458 Ref: 387910074458 Ref: c-api/typeobj c PyTypeObject tp_itemsize10074509 Ref: 387810074509 Ref: c-api/typeobj c PyTypeObject tp_dealloc10077162 Ref: 387f10077162 Ref: c-api/typeobj c PyTypeObject tp_vectorcall_offset10079214 Ref: 3a1110079214 Ref: c-api/typeobj c PyVectorcall_Call10080348 Ref: 3e2410080348 Ref: c-api/typeobj c PyTypeObject tp_getattr10081975 Ref: 38a210081975 Ref: c-api/typeobj c PyTypeObject tp_setattr10082696 Ref: 38a310082696 Ref: c-api/typeobj c PyTypeObject tp_as_async10083437 Ref: 3dba10083437 Ref: c-api/typeobj c PyTypeObject tp_repr10083979 Ref: 389a10083979 Ref: c-api/typeobj c PyTypeObject tp_as_number10084928 Ref: 3dbd10084928 Ref: c-api/typeobj c PyTypeObject tp_as_sequence10085329 Ref: 3dbe10085329 Ref: c-api/typeobj c PyTypeObject tp_as_mapping10085740 Ref: 3dbf10085740 Ref: c-api/typeobj c PyTypeObject tp_hash10086146 Ref: 38ac10086146 Ref: c-api/typeobj c PyTypeObject tp_call10087734 Ref: 38ad10087734 Ref: c-api/typeobj c PyTypeObject tp_str10088134 Ref: 389c10088134 Ref: c-api/typeobj c PyTypeObject tp_getattro10089081 Ref: 389f10089081 Ref: c-api/typeobj c PyTypeObject tp_setattro10089944 Ref: 38a010089944 Ref: c-api/typeobj c PyTypeObject tp_as_buffer10090938 Ref: 3dc410090938 Ref: c-api/typeobj c PyTypeObject tp_flags10091338 Ref: 3ab610091338 Ref: c-api/typeobj Py_TPFLAGS_HEAPTYPE10093230 Ref: 3abe10093230 Ref: c-api/typeobj Py_TPFLAGS_BASETYPE10093875 Ref: 388710093875 Ref: c-api/typeobj Py_TPFLAGS_READY10094152 Ref: 3e2a10094152 Ref: c-api/typeobj Py_TPFLAGS_READYING10094342 Ref: 3e2b10094342 Ref: c-api/typeobj Py_TPFLAGS_HAVE_GC10094541 Ref: 388e10094541 Ref: c-api/typeobj Py_TPFLAGS_DEFAULT10095522 Ref: 387a10095522 Ref: c-api/typeobj Py_TPFLAGS_METHOD_DESCRIPTOR10095902 Ref: 3e2d10095902 Ref: c-api/typeobj Py_TPFLAGS_LONG_SUBCLASS10096767 Ref: 3e2e10096767 Ref: c-api/typeobj Py_TPFLAGS_LIST_SUBCLASS10096808 Ref: 3e2f10096808 Ref: c-api/typeobj Py_TPFLAGS_TUPLE_SUBCLASS10096849 Ref: 3e3010096849 Ref: c-api/typeobj Py_TPFLAGS_BYTES_SUBCLASS10096891 Ref: 3e3110096891 Ref: c-api/typeobj Py_TPFLAGS_UNICODE_SUBCLASS10096933 Ref: 3e3210096933 Ref: c-api/typeobj Py_TPFLAGS_DICT_SUBCLASS10096977 Ref: 3e3310096977 Ref: c-api/typeobj Py_TPFLAGS_BASE_EXC_SUBCLASS10097018 Ref: 3e3410097018 Ref: c-api/typeobj Py_TPFLAGS_TYPE_SUBCLASS10097063 Ref: 3e3510097063 Ref: c-api/typeobj Py_TPFLAGS_HAVE_FINALIZE10097621 Ref: 2d810097621 Ref: c-api/typeobj _Py_TPFLAGS_HAVE_VECTORCALL10098001 Ref: 3e2210098001 Ref: c-api/typeobj c PyTypeObject tp_doc10098899 Ref: 387b10098899 Ref: c-api/typeobj c PyTypeObject tp_traverse10099211 Ref: 33e810099211 Ref: c-api/typeobj c PyTypeObject tp_clear10102127 Ref: 389810102127 Ref: c-api/typeobj c PyTypeObject tp_richcompare10105454 Ref: 38a510105454 Ref: c-api/typeobj c Py_RETURN_RICHCOMPARE10106979 Ref: 42210106979 Ref: c-api/typeobj c PyTypeObject tp_weaklistoffset10108214 Ref: 38af10108214 Ref: c-api/typeobj c PyTypeObject tp_iter10109997 Ref: e3010109997 Ref: c-api/typeobj c PyTypeObject tp_iternext10110471 Ref: e3110110471 Ref: c-api/typeobj c PyTypeObject tp_methods10111263 Ref: 388610111263 Ref: c-api/typeobj c PyTypeObject tp_members10111759 Ref: 388410111759 Ref: c-api/typeobj c PyTypeObject tp_getset10112291 Ref: 388a10112291 Ref: c-api/typeobj c PyTypeObject tp_base10112815 Ref: 389010112815 Ref: c-api/typeobj c PyTypeObject tp_dict10114109 Ref: 3aca10114109 Ref: c-api/typeobj c PyTypeObject tp_descr_get10115087 Ref: 3dcb10115087 Ref: c-api/typeobj c PyTypeObject tp_descr_set10115383 Ref: 3dcd10115383 Ref: c-api/typeobj c PyTypeObject tp_dictoffset10115774 Ref: 3acf10115774 Ref: c-api/typeobj c PyTypeObject tp_init10119032 Ref: 388310119032 Ref: c-api/typeobj c PyTypeObject tp_alloc10120488 Ref: 388110120488 Ref: c-api/typeobj c PyTypeObject tp_new10121173 Ref: 387c10121173 Ref: c-api/typeobj c PyTypeObject tp_free10122737 Ref: 388010122737 Ref: c-api/typeobj c PyTypeObject tp_is_gc10123421 Ref: 3dd310123421 Ref: c-api/typeobj c PyTypeObject tp_bases10124572 Ref: 3dd410124572 Ref: c-api/typeobj c PyTypeObject tp_mro10124820 Ref: 3acb10124820 Ref: c-api/typeobj c PyTypeObject tp_cache10125138 Ref: 3acc10125138 Ref: c-api/typeobj c PyTypeObject tp_subclasses10125275 Ref: 3acd10125275 Ref: c-api/typeobj c PyTypeObject tp_weaklist10125448 Ref: 3ace10125448 Ref: c-api/typeobj c PyTypeObject tp_del10125667 Ref: 3dd510125667 Ref: c-api/typeobj c PyTypeObject tp_version_tag10125783 Ref: 3dd610125783 Ref: c-api/typeobj c PyTypeObject tp_finalize10125958 Ref: 2d710125958 Ref: c-api/typeobj c PyTypeObject tp_allocs10127682 Ref: 3dd710127682 Ref: c-api/typeobj c PyTypeObject tp_frees10127760 Ref: 3dd810127760 Ref: c-api/typeobj c PyTypeObject tp_maxalloc10127831 Ref: 3dd910127831 Ref: c-api/typeobj c PyTypeObject tp_prev10127930 Ref: 3dda10127930 Ref: c-api/typeobj c PyTypeObject tp_next10128073 Ref: 3ddb10128073 Ref: PyTypeObject Slots-Footnote-110128905 Node: Heap Types10128954 Ref: c-api/typeobj heap-types10129043 Ref: 3abc10129043 Ref: c-api/typeobj id410129043 Ref: 3e2510129043 Node: Number Object Structures10130207 Ref: c-api/typeobj number-object-structures10130355 Ref: 3e3610130355 Ref: c-api/typeobj number-structs10130355 Ref: 3e2710130355 Ref: c-api/typeobj c PyNumberMethods10130420 Ref: d8110130420 Ref: c-api/typeobj c PyNumberMethods nb_add10132846 Ref: 3ac810132846 Ref: c-api/typeobj c PyNumberMethods nb_subtract10132895 Ref: 3de310132895 Ref: c-api/typeobj c PyNumberMethods nb_multiply10132949 Ref: 3de510132949 Ref: c-api/typeobj c PyNumberMethods nb_remainder10133003 Ref: 3de710133003 Ref: c-api/typeobj c PyNumberMethods nb_divmod10133058 Ref: 3de910133058 Ref: c-api/typeobj c PyNumberMethods nb_power10133110 Ref: 3dea10133110 Ref: c-api/typeobj c PyNumberMethods nb_negative10133162 Ref: 3dec10133162 Ref: c-api/typeobj c PyNumberMethods nb_positive10133215 Ref: 3ded10133215 Ref: c-api/typeobj c PyNumberMethods nb_absolute10133268 Ref: 3dee10133268 Ref: c-api/typeobj c PyNumberMethods nb_bool10133321 Ref: 3def10133321 Ref: c-api/typeobj c PyNumberMethods nb_invert10133368 Ref: 3df010133368 Ref: c-api/typeobj c PyNumberMethods nb_lshift10133419 Ref: 3df110133419 Ref: c-api/typeobj c PyNumberMethods nb_rshift10133471 Ref: 3df310133471 Ref: c-api/typeobj c PyNumberMethods nb_and10133523 Ref: 3df510133523 Ref: c-api/typeobj c PyNumberMethods nb_xor10133572 Ref: 3df710133572 Ref: c-api/typeobj c PyNumberMethods nb_or10133621 Ref: 3df910133621 Ref: c-api/typeobj c PyNumberMethods nb_int10133669 Ref: 3dfb10133669 Ref: c-api/typeobj c PyNumberMethods nb_reserved10133717 Ref: 3dfc10133717 Ref: c-api/typeobj c PyNumberMethods nb_float10133766 Ref: 3dfd10133766 Ref: c-api/typeobj c PyNumberMethods nb_inplace_add10133816 Ref: 3de210133816 Ref: c-api/typeobj c PyNumberMethods nb_inplace_subtract10133873 Ref: 3de410133873 Ref: c-api/typeobj c PyNumberMethods nb_inplace_multiply10133935 Ref: 3de610133935 Ref: c-api/typeobj c PyNumberMethods nb_inplace_remainder10133997 Ref: 3de810133997 Ref: c-api/typeobj c PyNumberMethods nb_inplace_power10134060 Ref: 3deb10134060 Ref: c-api/typeobj c PyNumberMethods nb_inplace_lshift10134120 Ref: 3df210134120 Ref: c-api/typeobj c PyNumberMethods nb_inplace_rshift10134180 Ref: 3df410134180 Ref: c-api/typeobj c PyNumberMethods nb_inplace_and10134240 Ref: 3df610134240 Ref: c-api/typeobj c PyNumberMethods nb_inplace_xor10134297 Ref: 3df810134297 Ref: c-api/typeobj c PyNumberMethods nb_inplace_or10134354 Ref: 3dfa10134354 Ref: c-api/typeobj c PyNumberMethods nb_floor_divide10134410 Ref: 3dfe10134410 Ref: c-api/typeobj c PyNumberMethods nb_true_divide10134468 Ref: 3e0010134468 Ref: c-api/typeobj c PyNumberMethods nb_inplace_floor_divide10134525 Ref: 3dff10134525 Ref: c-api/typeobj c PyNumberMethods nb_inplace_true_divide10134591 Ref: 3e0110134591 Ref: c-api/typeobj c PyNumberMethods nb_index10134656 Ref: 3e0210134656 Ref: c-api/typeobj c PyNumberMethods nb_matrix_multiply10134706 Ref: 3e0310134706 Ref: c-api/typeobj c PyNumberMethods nb_inplace_matrix_multiply10134767 Ref: 3e0410134767 Node: Mapping Object Structures10134836 Ref: c-api/typeobj mapping-object-structures10134995 Ref: 3e3710134995 Ref: c-api/typeobj mapping-structs10134995 Ref: 3e2910134995 Ref: c-api/typeobj c PyMappingMethods10135062 Ref: 38ab10135062 Ref: c-api/typeobj c PyMappingMethods mp_length10135229 Ref: 3e0510135229 Ref: c-api/typeobj c PyMappingMethods mp_subscript10135484 Ref: 3e0710135484 Ref: c-api/typeobj c PyMappingMethods mp_ass_subscript10135843 Ref: 3e0810135843 Node: Sequence Object Structures10136283 Ref: c-api/typeobj sequence-object-structures10136442 Ref: 3e3810136442 Ref: c-api/typeobj sequence-structs10136442 Ref: 3e2810136442 Ref: c-api/typeobj c PySequenceMethods10136511 Ref: 38aa10136511 Ref: c-api/typeobj c PySequenceMethods sq_length10136657 Ref: 3ac910136657 Ref: c-api/typeobj c PySequenceMethods sq_concat10136962 Ref: 3e0a10136962 Ref: c-api/typeobj c PySequenceMethods sq_repeat10137228 Ref: 3e0b10137228 Ref: c-api/typeobj c PySequenceMethods sq_item10137508 Ref: 3e0d10137508 Ref: c-api/typeobj c PySequenceMethods sq_ass_item10138214 Ref: 3e0e10138214 Ref: c-api/typeobj c PySequenceMethods sq_contains10138668 Ref: 3e1010138668 Ref: c-api/typeobj c PySequenceMethods sq_inplace_concat10138970 Ref: 3e1210138970 Ref: c-api/typeobj c PySequenceMethods sq_inplace_repeat10139484 Ref: 3e1310139484 Node: Buffer Object Structures10140011 Ref: c-api/typeobj buffer-object-structures10140168 Ref: 3e3910140168 Ref: c-api/typeobj buffer-structs10140168 Ref: 3a6e10140168 Ref: c-api/typeobj c PyBufferProcs10140233 Ref: 3dc510140233 Ref: c-api/typeobj c PyBufferProcs bf_getbuffer10140463 Ref: 3ad010140463 Ref: c-api/typeobj c PyBufferProcs bf_releasebuffer10142355 Ref: 39c910142355 Node: Async Object Structures10143467 Ref: c-api/typeobj async-object-structures10143616 Ref: 3e3a10143616 Ref: c-api/typeobj async-structs10143616 Ref: 3e2610143616 Ref: c-api/typeobj c PyAsyncMethods10143700 Ref: 3ac710143700 Ref: c-api/typeobj c PyAsyncMethods am_await10144080 Ref: 3ddd10144080 Ref: c-api/typeobj c PyAsyncMethods am_aiter10144422 Ref: 3ddf10144422 Ref: c-api/typeobj c PyAsyncMethods am_anext10144769 Ref: 3de010144769 Node: Slot Type typedefs10145042 Ref: c-api/typeobj id510145179 Ref: 3e1810145179 Ref: c-api/typeobj slot-type-typedefs10145179 Ref: 3e3b10145179 Ref: c-api/typeobj c allocfunc10145232 Ref: 3dd010145232 Ref: c-api/typeobj c destructor10146199 Ref: 3db710146199 Ref: c-api/typeobj c vectorcallfunc10146244 Ref: 3e2310146244 Ref: c-api/typeobj c freefunc10146544 Ref: 3dd210146544 Ref: c-api/typeobj c newfunc10146614 Ref: 3dd110146614 Ref: c-api/typeobj c initproc10146715 Ref: 3dcf10146715 Ref: c-api/typeobj c reprfunc10146812 Ref: 3dbc10146812 Ref: c-api/typeobj c getattrfunc10146891 Ref: 3db810146891 Ref: c-api/typeobj c setattrfunc10147020 Ref: 3db910147020 Ref: c-api/typeobj c getattrofunc10147238 Ref: 3dc210147238 Ref: c-api/typeobj c setattrofunc10147407 Ref: 3dc310147407 Ref: c-api/typeobj c descrgetfunc10147665 Ref: 3dcc10147665 Ref: c-api/typeobj c descrsetfunc10147780 Ref: 3dce10147780 Ref: c-api/typeobj c hashfunc10147879 Ref: 3dc010147879 Ref: c-api/typeobj c richcmpfunc10147958 Ref: 3dc810147958 Ref: c-api/typeobj c getiterfunc10148064 Ref: 3dc910148064 Ref: c-api/typeobj c iternextfunc10148145 Ref: 3dca10148145 Ref: c-api/typeobj c lenfunc10148231 Ref: 3e0610148231 Ref: c-api/typeobj c getbufferproc10148279 Ref: 3e1410148279 Ref: c-api/typeobj c releasebufferproc10148344 Ref: 3e1510148344 Ref: c-api/typeobj c unaryfunc10148409 Ref: 3dde10148409 Ref: c-api/typeobj c binaryfunc10148458 Ref: 3de110148458 Ref: c-api/typeobj c ternaryfunc10148520 Ref: 3dc110148520 Ref: c-api/typeobj c ssizeargfunc10148605 Ref: 3e0c10148605 Ref: c-api/typeobj c ssizeobjargproc10148669 Ref: 3e0f10148669 Ref: c-api/typeobj c objobjproc10148730 Ref: 3e1110148730 Ref: c-api/typeobj c objobjargproc10148786 Ref: 3e0910148786 Node: Examples<35>10148857 Ref: c-api/typeobj examples10149007 Ref: 3e3c10149007 Ref: c-api/typeobj typedef-examples10149007 Ref: 3db210149007 Node: Supporting Cyclic Garbage Collection10154344 Ref: c-api/gcsupport doc10154467 Ref: 3e3d10154467 Ref: c-api/gcsupport supporting-cycle-detection10154467 Ref: 3e2c10154467 Ref: c-api/gcsupport supporting-cyclic-garbage-collection10154467 Ref: 3e3e10154467 Ref: c-api/gcsupport c PyObject_GC_New10155799 Ref: 2d410155799 Ref: c-api/gcsupport c PyObject_GC_NewVar10155993 Ref: 2d510155993 Ref: c-api/gcsupport c PyObject_GC_Resize10156220 Ref: 3e3f10156220 Ref: c-api/gcsupport c PyObject_GC_Track10156493 Ref: e4410156493 Ref: c-api/gcsupport c PyObject_GC_Del10157186 Ref: e4310157186 Ref: c-api/gcsupport c PyObject_GC_UnTrack10157357 Ref: e4510157357 Ref: c-api/gcsupport c visitproc10158035 Ref: 3e1710158035 Ref: c-api/gcsupport c traverseproc10158581 Ref: 3dc610158581 Ref: c-api/gcsupport c Py_VISIT10159319 Ref: 388c10159319 Ref: c-api/gcsupport c inquiry10159902 Ref: 3dc710159902 Node: API and ABI Versioning10160377 Ref: c-api/apiabiversion doc10160503 Ref: 3e4010160503 Ref: c-api/apiabiversion api-and-abi-versioning10160503 Ref: 3e4110160503 Ref: c-api/apiabiversion apiabiversion10160503 Ref: 335e10160503 Ref: API and ABI Versioning-Footnote-110162454 Node: Distributing Python Modules10162526 Ref: distributing/index doc10162665 Ref: 3e4210162665 Ref: distributing/index distributing-index10162665 Ref: 7f610162665 Ref: distributing/index distributing-python-modules10162665 Ref: 3e4310162665 Node: Key terms10163846 Ref: distributing/index key-terms10163967 Ref: 3e4410163967 Ref: Key terms-Footnote-110165907 Ref: Key terms-Footnote-210165932 Ref: Key terms-Footnote-310165961 Ref: Key terms-Footnote-410165993 Ref: Key terms-Footnote-510166029 Ref: Key terms-Footnote-610166082 Ref: Key terms-Footnote-710166120 Ref: Key terms-Footnote-810166173 Node: Open source licensing and collaboration10166222 Ref: distributing/index open-source-licensing-and-collaboration10166372 Ref: 3e4510166372 Ref: distributing/index wheel10166372 Ref: 3e4610166372 Node: Installing the tools10167390 Ref: distributing/index installing-the-tools10167570 Ref: 3e4710167570 Ref: Installing the tools-Footnote-110168472 Node: Reading the Python Packaging User Guide10168570 Ref: distributing/index publishing-python-packages10168723 Ref: 3e4810168723 Ref: distributing/index reading-the-python-packaging-user-guide10168723 Ref: 3e4910168723 Ref: Reading the Python Packaging User Guide-Footnote-110169128 Ref: Reading the Python Packaging User Guide-Footnote-210169198 Ref: Reading the Python Packaging User Guide-Footnote-310169292 Ref: Reading the Python Packaging User Guide-Footnote-410169394 Node: How do I…?10169454 Ref: distributing/index how-do-i10169578 Ref: 3e4a10169578 Ref: distributing/index the-pypirc-file10169578 Ref: 3e4b10169578 Node: … choose a name for my project?10169765 Ref: distributing/index choose-a-name-for-my-project10169900 Ref: 3e4c10169900 Node: … create and distribute binary extensions?10170482 Ref: distributing/index create-and-distribute-binary-extensions10170617 Ref: 3e4d10170617 Ref: … create and distribute binary extensions?-Footnote-110171039 Node: Installing Python Modules10171112 Ref: installing/index doc10171235 Ref: 3e4e10171235 Ref: installing/index installing-index10171235 Ref: 7f510171235 Ref: installing/index installing-python-modules10171235 Ref: 3e4f10171235 Node: Key terms<2>10172373 Ref: installing/index key-terms10172467 Ref: 3e5010172467 Ref: Key terms<2>-Footnote-110174593 Ref: Key terms<2>-Footnote-210174618 Ref: Key terms<2>-Footnote-310174647 Ref: Key terms<2>-Footnote-410174679 Ref: Key terms<2>-Footnote-510174715 Node: Basic usage10174795 Ref: installing/index basic-usage10174911 Ref: 3e5110174911 Ref: Basic usage-Footnote-110176566 Ref: Basic usage-Footnote-210176603 Node: How do I …?10176652 Ref: installing/index how-do-i10176782 Ref: 3e5210176782 Node: … install pip in versions of Python prior to Python 3 4?10177171 Ref: installing/index install-pip-in-versions-of-python-prior-to-python-3-410177335 Ref: 3e5310177335 Ref: … install pip in versions of Python prior to Python 3 4?-Footnote-110177767 Node: … install packages just for the current user?10177854 Ref: installing/index install-packages-just-for-the-current-user10178066 Ref: 3e5410178066 Node: … install scientific Python packages?10178328 Ref: installing/index install-scientific-python-packages10178546 Ref: 3e5510178546 Ref: … install scientific Python packages?-Footnote-110179052 Ref: … install scientific Python packages?-Footnote-210179098 Node: … work with multiple versions of Python installed in parallel?10179144 Ref: installing/index work-with-multiple-versions-of-python-installed-in-parallel10179306 Ref: 3e5610179306 Node: Common installation issues10180281 Ref: installing/index common-installation-issues10180391 Ref: 3e5710180391 Node: Installing into the system Python on Linux10180566 Ref: installing/index installing-into-the-system-python-on-linux10180697 Ref: 3e5810180697 Node: Pip not installed10181264 Ref: installing/index pip-not-installed10181432 Ref: 3e5910181432 Ref: Pip not installed-Footnote-110181706 Node: Installing binary extensions10181808 Ref: installing/index installing-binary-extensions10181925 Ref: 3e5a10181925 Ref: Installing binary extensions-Footnote-110182820 Ref: Installing binary extensions-Footnote-210182866 Node: Python HOWTOs10182915 Ref: howto/index doc10183044 Ref: 3e5b10183044 Ref: howto/index python-howtos10183044 Ref: 3e5c10183044 Node: Porting Python 2 Code to Python 310183918 Ref: howto/pyporting doc10184047 Ref: 3e5d10184047 Ref: howto/pyporting porting-python-2-code-to-python-310184047 Ref: 3e5e10184047 Ref: howto/pyporting pyporting-howto10184047 Ref: c7d10184047 Ref: Porting Python 2 Code to Python 3-Footnote-110184926 Ref: Porting Python 2 Code to Python 3-Footnote-210185030 Ref: Porting Python 2 Code to Python 3-Footnote-310185076 Node: The Short Explanation10185140 Ref: howto/pyporting the-short-explanation10185247 Ref: 3e5f10185247 Ref: The Short Explanation-Footnote-110186398 Ref: The Short Explanation-Footnote-210186440 Ref: The Short Explanation-Footnote-310186499 Ref: The Short Explanation-Footnote-410186548 Ref: The Short Explanation-Footnote-510186588 Ref: The Short Explanation-Footnote-610186636 Ref: The Short Explanation-Footnote-710186673 Node: Details10186703 Ref: howto/pyporting details10186810 Ref: 3e6010186810 Node: Drop support for Python 2 6 and older10188286 Ref: howto/pyporting drop-support-for-python-2-6-and-older10188446 Ref: 3e6110188446 Ref: Drop support for Python 2 6 and older-Footnote-110189771 Ref: Drop support for Python 2 6 and older-Footnote-210189808 Node: Make sure you specify the proper version support in your setup py file10189848 Ref: howto/pyporting make-sure-you-specify-the-proper-version-support-in-your-setup-py-file10190040 Ref: 3e6210190040 Ref: Make sure you specify the proper version support in your setup py file-Footnote-110190642 Node: Have good test coverage10190679 Ref: howto/pyporting have-good-test-coverage10190876 Ref: 3e6310190876 Ref: Have good test coverage-Footnote-110191562 Node: Learn the differences between Python 2 & 310191604 Ref: howto/pyporting learn-the-differences-between-python-2-310191747 Ref: 3e6410191747 Ref: Learn the differences between Python 2 & 3-Footnote-110192412 Ref: Learn the differences between Python 2 & 3-Footnote-210192447 Node: Update your code10192503 Ref: howto/pyporting update-your-code10192656 Ref: 3e6510192656 Ref: Update your code-Footnote-110194932 Ref: Update your code-Footnote-210194991 Ref: Update your code-Footnote-310195040 Ref: Update your code-Footnote-410195099 Ref: Update your code-Footnote-510195148 Node: Division10195185 Ref: howto/pyporting division10195278 Ref: 3e6610195278 Node: Text versus binary data10196334 Ref: howto/pyporting text-versus-binary-data10196486 Ref: 3e6710196486 Ref: Text versus binary data-Footnote-110203001 Node: Use feature detection instead of version detection10203038 Ref: howto/pyporting use-feature-detection-instead-of-version-detection10203173 Ref: 3e6810203173 Ref: Use feature detection instead of version detection-Footnote-110204876 Node: Prevent compatibility regressions10204920 Ref: howto/pyporting prevent-compatibility-regressions10205077 Ref: 3e6910205077 Ref: Prevent compatibility regressions-Footnote-110206419 Ref: Prevent compatibility regressions-Footnote-210206459 Ref: Prevent compatibility regressions-Footnote-310206508 Node: Check which dependencies block your transition10206567 Ref: howto/pyporting check-which-dependencies-block-your-transition10206766 Ref: 3e6a10206766 Ref: Check which dependencies block your transition-Footnote-110207628 Node: Update your setup py file to denote Python 3 compatibility10207676 Ref: howto/pyporting update-your-setup-py-file-to-denote-python-3-compatibility10207887 Ref: 3e6b10207887 Node: Use continuous integration to stay compatible10208401 Ref: howto/pyporting use-continuous-integration-to-stay-compatible10208610 Ref: 3e6c10208610 Ref: Use continuous integration to stay compatible-Footnote-110209922 Node: Consider using optional static type checking10209959 Ref: howto/pyporting consider-using-optional-static-type-checking10210101 Ref: 3e6d10210101 Ref: Consider using optional static type checking-Footnote-110210882 Ref: Consider using optional static type checking-Footnote-210210912 Node: Porting Extension Modules to Python 310210953 Ref: howto/cporting doc10211121 Ref: 3e6e10211121 Ref: howto/cporting cporting-howto10211121 Ref: c7710211121 Ref: howto/cporting porting-extension-modules-to-python-310211121 Ref: 3e6f10211121 Ref: howto/cporting why-python-3-exists10211121 Ref: 3e7010211121 Ref: Porting Extension Modules to Python 3-Footnote-110211903 Ref: Porting Extension Modules to Python 3-Footnote-210211954 Ref: Porting Extension Modules to Python 3-Footnote-310212011 Ref: Porting Extension Modules to Python 3-Footnote-410212038 Node: Curses Programming with Python10212085 Ref: howto/curses doc10212242 Ref: 3e7110212242 Ref: howto/curses cffi10212242 Ref: 3e7210212242 Ref: howto/curses curses-howto10212242 Ref: 1e2e10212242 Ref: howto/curses curses-programming-with-python10212242 Ref: 3e7310212242 Node: What is curses?10212653 Ref: howto/curses what-is-curses10212784 Ref: 3e7410212784 Ref: What is curses?-Footnote-110215344 Ref: What is curses?-Footnote-210215384 Ref: What is curses?-Footnote-310215427 Node: The Python curses module10215476 Ref: howto/curses the-python-curses-module10215552 Ref: 3e7510215552 Node: Starting and ending a curses application10216381 Ref: howto/curses starting-and-ending-a-curses-application10216537 Ref: 3e7610216537 Node: Windows and Pads10219801 Ref: howto/curses windows-and-pads10219957 Ref: 3e7710219957 Node: Displaying Text10224503 Ref: howto/curses displaying-text10224629 Ref: 3e7810224629 Node: Attributes and Color10228415 Ref: howto/curses attributes-and-color10228487 Ref: 3e7910228487 Node: User Input10233047 Ref: howto/curses user-input10233177 Ref: 3e7a10233177 Ref: User Input-Footnote-110236981 Node: For More Information10237021 Ref: howto/curses for-more-information10237127 Ref: 3e7b10237127 Ref: For More Information-Footnote-110238626 Ref: For More Information-Footnote-210238663 Ref: For More Information-Footnote-310238726 Ref: For More Information-Footnote-410238770 Ref: For More Information-Footnote-510238831 Ref: For More Information-Footnote-610238883 Node: Descriptor HowTo Guide10238957 Ref: howto/descriptor doc10239105 Ref: 3e7c10239105 Ref: howto/descriptor descriptor-howto-guide10239105 Ref: 3e7d10239105 Node: Abstract10239454 Ref: howto/descriptor abstract10239557 Ref: 3e7e10239557 Node: Definition and Introduction10240076 Ref: howto/descriptor definition-and-introduction10240207 Ref: 3e7f10240207 Node: Descriptor Protocol10241562 Ref: howto/descriptor descriptor-protocol10241708 Ref: 3e8010241708 Node: Invoking Descriptors<2>10243019 Ref: howto/descriptor invoking-descriptors10243156 Ref: 3e8110243156 Ref: Invoking Descriptors<2>-Footnote-110246152 Ref: Invoking Descriptors<2>-Footnote-210246220 Ref: Invoking Descriptors<2>-Footnote-310246292 Node: Descriptor Example10246372 Ref: howto/descriptor descriptor-example10246500 Ref: 3e8210246500 Node: Properties10247902 Ref: howto/descriptor properties10248028 Ref: 3e8310248028 Node: Functions and Methods10250755 Ref: howto/descriptor functions-and-methods10250895 Ref: 3e8410250895 Node: Static Methods and Class Methods10253094 Ref: howto/descriptor static-methods-and-class-methods10253215 Ref: 3e8510253215 Node: Functional Programming HOWTO10257809 Ref: howto/functional doc10257940 Ref: 3e8610257940 Ref: howto/functional functional-programming-howto10257940 Ref: 3e8710257940 Node: Introduction<14>10258751 Ref: howto/functional introduction10258853 Ref: 3e8810258853 Node: Formal provability10263567 Ref: howto/functional formal-provability10263657 Ref: 3e8a10263657 Node: Modularity10265573 Ref: howto/functional modularity10265701 Ref: 3e8b10265701 Node: Ease of debugging and testing10266108 Ref: howto/functional ease-of-debugging-and-testing10266231 Ref: 3e8c10266231 Node: Composability10266968 Ref: howto/functional composability10267072 Ref: 3e8d10267072 Node: Iterators<2>10267797 Ref: howto/functional functional-howto-iterators10267953 Ref: 3e8910267953 Ref: howto/functional iterators10267953 Ref: 3e8e10267953 Node: Data Types That Support Iterators10271316 Ref: howto/functional data-types-that-support-iterators10271398 Ref: 3e8f10271398 Node: Generator expressions and list comprehensions10273308 Ref: howto/functional generator-expressions-and-list-comprehensions10273461 Ref: 3e9010273461 Node: Generators<2>10277968 Ref: howto/functional generators10278127 Ref: 3e9110278127 Ref: Generators<2>-Footnote-110281985 Node: Passing values into a generator10282065 Ref: howto/functional passing-values-into-a-generator10282146 Ref: 3e9210282146 Ref: Passing values into a generator-Footnote-110286140 Node: Built-in functions10286189 Ref: howto/functional built-in-functions10286323 Ref: 3e9310286323 Ref: Built-in functions-Footnote-110290361 Node: The itertools module10290415 Ref: howto/functional the-itertools-module10290556 Ref: 3e9410290556 Node: Creating new iterators10291301 Ref: howto/functional creating-new-iterators10291418 Ref: 3e9510291418 Node: Calling functions on elements10294103 Ref: howto/functional calling-functions-on-elements10294247 Ref: 3e9610294247 Node: Selecting elements10295064 Ref: howto/functional selecting-elements10295208 Ref: 3e9710295208 Node: Combinatoric functions10296700 Ref: howto/functional combinatoric-functions10296832 Ref: 3e9810296832 Node: Grouping elements10299165 Ref: howto/functional grouping-elements10299270 Ref: 3e9910299270 Node: The functools module10300822 Ref: howto/functional the-functools-module10300986 Ref: 3e9a10300986 Node: The operator module10304603 Ref: howto/functional the-operator-module10304679 Ref: 3e9b10304679 Node: Small functions and the lambda expression10305493 Ref: howto/functional small-functions-and-the-lambda-expression10305674 Ref: 3e9c10305674 Node: Revision History and Acknowledgements10308533 Ref: howto/functional revision-history-and-acknowledgements10308707 Ref: 3e9d10308707 Node: References<2>10309486 Ref: howto/functional references10309610 Ref: 3e9e10309610 Node: General10309716 Ref: howto/functional general10309797 Ref: 3e9f10309797 Node: Python-specific10310738 Ref: howto/functional python-specific10310848 Ref: 3ea010310848 Ref: Python-specific-Footnote-110311323 Ref: Python-specific-Footnote-210311374 Ref: Python-specific-Footnote-310311427 Node: Python documentation10311480 Ref: howto/functional python-documentation10311574 Ref: 3ea110311574 Ref: Python documentation-Footnote-110311975 Ref: Python documentation-Footnote-210312024 Node: Logging HOWTO10312073 Ref: howto/logging doc10312198 Ref: 3ea210312198 Ref: howto/logging logging-howto10312198 Ref: 3ea310312198 Node: Basic Logging Tutorial10312511 Ref: howto/logging basic-logging-tutorial10312617 Ref: 3ea410312617 Ref: howto/logging logging-basic-tutorial10312617 Ref: b7210312617 Node: When to use logging10313403 Ref: howto/logging when-to-use-logging10313506 Ref: 3ea510313506 Node: A simple example10317397 Ref: howto/logging a-simple-example10317526 Ref: 3ea610317526 Ref: howto/logging howto-minimal-example10317526 Ref: 3ea710317526 Node: Logging to a file10318313 Ref: howto/logging logging-to-a-file10318452 Ref: 3ea810318452 Node: Logging from multiple modules10320965 Ref: howto/logging logging-from-multiple-modules10321109 Ref: 3ea910321109 Node: Logging variable data10322315 Ref: howto/logging logging-variable-data10322483 Ref: 3eaa10322483 Node: Changing the format of displayed messages10323302 Ref: howto/logging changing-the-format-of-displayed-messages10323477 Ref: 3eab10323477 Node: Displaying the date/time in messages10324473 Ref: howto/logging displaying-the-date-time-in-messages10324637 Ref: 3eac10324637 Ref: Displaying the date/time in messages-Footnote-110325689 Node: Next Steps10325738 Ref: howto/logging next-steps10325852 Ref: 3ead10325852 Node: Advanced Logging Tutorial10326810 Ref: howto/logging advanced-logging-tutorial10326942 Ref: 3eae10326942 Ref: howto/logging logging-advanced-tutorial10326942 Ref: b7310326942 Node: Logging Flow10330333 Ref: howto/logging logging-flow10330423 Ref: 3eaf10330423 Node: Loggers10330598 Ref: howto/logging loggers10330705 Ref: 3eb010330705 Node: Handlers10334986 Ref: howto/logging handler-basic10335091 Ref: 3eb110335091 Ref: howto/logging handlers10335091 Ref: 3eb210335091 Node: Formatters10337159 Ref: howto/logging formatters10337276 Ref: 3eb410337276 Ref: howto/logging logging logging Formatter __init__10337726 Ref: 3eb510337726 Node: Configuring Logging10339418 Ref: howto/logging configuring-logging10339571 Ref: 3eb610339571 Node: What happens if no configuration is provided10346135 Ref: howto/logging what-happens-if-no-configuration-is-provided10346311 Ref: 3eb710346311 Node: Configuring Logging for a Library10347738 Ref: howto/logging configuring-logging-for-a-library10347886 Ref: 3eb810347886 Ref: howto/logging library-config10347886 Ref: 1dd610347886 Node: Logging Levels<2>10350316 Ref: howto/logging logging-levels10350441 Ref: 3eb910350441 Node: Custom Levels10353302 Ref: howto/logging custom-levels10353369 Ref: 1da810353369 Ref: howto/logging id110353369 Ref: 3eba10353369 Node: Useful Handlers10354084 Ref: howto/logging id210354216 Ref: 3ebb10354216 Ref: howto/logging useful-handlers10354216 Ref: 3eb310354216 Node: Exceptions raised during logging10358224 Ref: howto/logging exceptions-raised-during-logging10358374 Ref: 3ebc10358374 Ref: howto/logging logging-exceptions10358374 Ref: 3ebd10358374 Node: Using arbitrary objects as messages10359530 Ref: howto/logging arbitrary-object-messages10359677 Ref: 1d9810359677 Ref: howto/logging using-arbitrary-objects-as-messages10359677 Ref: 3ebe10359677 Node: Optimization10360291 Ref: howto/logging optimization10360397 Ref: 3ebf10360397 Node: Logging Cookbook10363951 Ref: howto/logging-cookbook doc10364072 Ref: 3ec010364072 Ref: howto/logging-cookbook id110364072 Ref: 3ec110364072 Ref: howto/logging-cookbook logging-cookbook10364072 Ref: b7410364072 Node: Using logging in multiple modules10365683 Ref: howto/logging-cookbook using-logging-in-multiple-modules10365807 Ref: 3ec210365807 Node: Logging from multiple threads10369381 Ref: howto/logging-cookbook logging-from-multiple-threads10369546 Ref: 3ec310369546 Node: Multiple handlers and formatters10371293 Ref: howto/logging-cookbook multiple-handlers-and-formatters10371457 Ref: 3ec410371457 Node: Logging to multiple destinations10373620 Ref: howto/logging-cookbook logging-to-multiple-destinations10373783 Ref: 3ec510373783 Ref: howto/logging-cookbook multiple-destinations10373783 Ref: 3ec610373783 Node: Configuration server example10376634 Ref: howto/logging-cookbook configuration-server-example10376797 Ref: 3ec710376797 Node: Dealing with handlers that block10378359 Ref: howto/logging-cookbook dealing-with-handlers-that-block10378543 Ref: 3ec810378543 Node: Sending and receiving logging events across a network10382200 Ref: howto/logging-cookbook network-logging10382408 Ref: 3ec910382408 Ref: howto/logging-cookbook sending-and-receiving-logging-events-across-a-network10382408 Ref: 3eca10382408 Node: Adding contextual information to your logging output10387876 Ref: howto/logging-cookbook adding-contextual-information-to-your-logging-output10388100 Ref: 3ecb10388100 Ref: howto/logging-cookbook context-info10388100 Ref: 1d9b10388100 Node: Using LoggerAdapters to impart contextual information10389182 Ref: howto/logging-cookbook using-loggeradapters-to-impart-contextual-information10389379 Ref: 3ecc10389379 Node: Using objects other than dicts to pass contextual information10392527 Ref: howto/logging-cookbook using-objects-other-than-dicts-to-pass-contextual-information10392678 Ref: 3ecd10392678 Node: Using Filters to impart contextual information10393137 Ref: howto/logging-cookbook filters-contextual10393334 Ref: 1d9010393334 Ref: howto/logging-cookbook using-filters-to-impart-contextual-information10393334 Ref: 3ece10393334 Node: Logging to a single file from multiple processes10397139 Ref: howto/logging-cookbook logging-to-a-single-file-from-multiple-processes10397329 Ref: 3ecf10397329 Ref: howto/logging-cookbook multiple-processes10397329 Ref: 3ed010397329 Node: Using concurrent futures ProcessPoolExecutor10407759 Ref: howto/logging-cookbook using-concurrent-futures-processpoolexecutor10407888 Ref: 3ed110407888 Node: Using file rotation10408894 Ref: howto/logging-cookbook using-file-rotation10409068 Ref: 3ed210409068 Node: Use of alternative formatting styles10410966 Ref: howto/logging-cookbook format-styles10411113 Ref: 3ed310411113 Ref: howto/logging-cookbook use-of-alternative-formatting-styles10411113 Ref: 3ed410411113 Node: Customizing LogRecord10418299 Ref: howto/logging-cookbook custom-logrecord10418470 Ref: 3ed510418470 Ref: howto/logging-cookbook customizing-logrecord10418470 Ref: 3ed610418470 Node: Subclassing QueueHandler - a ZeroMQ example10422383 Ref: howto/logging-cookbook subclassing-queuehandler-a-zeromq-example10422562 Ref: 3ed710422562 Ref: howto/logging-cookbook zeromq-handlers10422562 Ref: 3ed810422562 Node: Subclassing QueueListener - a ZeroMQ example10423898 Ref: howto/logging-cookbook subclassing-queuelistener-a-zeromq-example10424097 Ref: 3ed910424097 Node: An example dictionary-based configuration10425218 Ref: howto/logging-cookbook an-example-dictionary-based-configuration10425436 Ref: 3eda10425436 Ref: An example dictionary-based configuration-Footnote-110427473 Ref: An example dictionary-based configuration-Footnote-210427559 Node: Using a rotator and namer to customize log rotation processing10427645 Ref: howto/logging-cookbook cookbook-rotator-namer10427859 Ref: 1de210427859 Ref: howto/logging-cookbook using-a-rotator-and-namer-to-customize-log-rotation-processing10427859 Ref: 3edb10427859 Node: A more elaborate multiprocessing example10428744 Ref: howto/logging-cookbook a-more-elaborate-multiprocessing-example10428970 Ref: 3edc10428970 Node: Inserting a BOM into messages sent to a SysLogHandler10438598 Ref: howto/logging-cookbook inserting-a-bom-into-messages-sent-to-a-sysloghandler10438793 Ref: 3edd10438793 Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-110440960 Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-210441009 Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-310441068 Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-410441117 Node: Implementing structured logging10441166 Ref: howto/logging-cookbook implementing-structured-logging10441357 Ref: 3ede10441357 Node: Customizing handlers with dictConfig10444104 Ref: howto/logging-cookbook custom-handlers10444304 Ref: 3edf10444304 Ref: howto/logging-cookbook customizing-handlers-with-dictconfig10444304 Ref: 3ee010444304 Node: Using particular formatting styles throughout your application10449497 Ref: howto/logging-cookbook formatting-styles10449701 Ref: 1d8710449701 Ref: howto/logging-cookbook using-particular-formatting-styles-throughout-your-application10449701 Ref: 3ee110449701 Node: Using LogRecord factories10451702 Ref: howto/logging-cookbook using-logrecord-factories10451863 Ref: 3ee210451863 Node: Using custom message objects10452839 Ref: howto/logging-cookbook using-custom-message-objects10453000 Ref: 3ee310453000 Node: Configuring filters with dictConfig10455710 Ref: howto/logging-cookbook configuring-filters-with-dictconfig10455909 Ref: 3ee410455909 Ref: howto/logging-cookbook filters-dictconfig10455909 Ref: 3ee510455909 Node: Customized exception formatting10458874 Ref: howto/logging-cookbook custom-format-exception10459036 Ref: 3ee610459036 Ref: howto/logging-cookbook customized-exception-formatting10459036 Ref: 3ee710459036 Node: Speaking logging messages10461166 Ref: howto/logging-cookbook speaking-logging-messages10461353 Ref: 3ee810461353 Ref: howto/logging-cookbook spoken-messages10461353 Ref: 3ee910461353 Node: Buffering logging messages and outputting them conditionally10463521 Ref: howto/logging-cookbook buffered-logging10463725 Ref: 3eea10463725 Ref: howto/logging-cookbook buffering-logging-messages-and-outputting-them-conditionally10463725 Ref: 3eeb10463725 Node: Formatting times using UTC GMT via configuration10469302 Ref: howto/logging-cookbook formatting-times-using-utc-gmt-via-configuration10469526 Ref: 3eec10469526 Ref: howto/logging-cookbook utc-formatting10469526 Ref: 3eed10469526 Node: Using a context manager for selective logging10471428 Ref: howto/logging-cookbook context-manager10471626 Ref: 3eee10471626 Ref: howto/logging-cookbook using-a-context-manager-for-selective-logging10471626 Ref: 3eef10471626 Node: A CLI application starter template10476208 Ref: howto/logging-cookbook a-cli-application-starter-template10476378 Ref: 3ef010476378 Ref: howto/logging-cookbook starter-template10476378 Ref: 3ef110476378 Node: A Qt GUI for logging10482361 Ref: howto/logging-cookbook a-qt-gui-for-logging10482477 Ref: 3ef210482477 Ref: howto/logging-cookbook qt-gui10482477 Ref: 3ef310482477 Ref: A Qt GUI for logging-Footnote-110491871 Ref: A Qt GUI for logging-Footnote-210491898 Ref: A Qt GUI for logging-Footnote-310491940 Node: Regular Expression HOWTO10491980 Ref: howto/regex doc10492112 Ref: 3ef410492112 Ref: howto/regex regex-howto10492112 Ref: 13f810492112 Ref: howto/regex regular-expression-howto10492112 Ref: 3ef510492112 Node: Introduction<15>10492609 Ref: howto/regex introduction10492710 Ref: 3ef610492710 Node: Simple Patterns10494315 Ref: howto/regex simple-patterns10494450 Ref: 3ef710494450 Node: Matching Characters10494945 Ref: howto/regex matching-characters10495041 Ref: 3ef810495041 Node: Repeating Things10499676 Ref: howto/regex repeating-things10499772 Ref: 3ef910499772 Node: Using Regular Expressions10504710 Ref: howto/regex using-regular-expressions10504847 Ref: 3efa10504847 Node: Compiling Regular Expressions10505340 Ref: howto/regex compiling-regular-expressions10505460 Ref: 3efb10505460 Node: The Backslash Plague10506677 Ref: howto/regex id110506824 Ref: 3efc10506824 Ref: howto/regex the-backslash-plague10506824 Ref: 3efd10506824 Node: Performing Matches10509710 Ref: howto/regex performing-matches10509853 Ref: 3efe10509853 Ref: Performing Matches-Footnote-110515758 Node: Module-Level Functions<2>10515830 Ref: howto/regex module-level-functions10515970 Ref: 3eff10515970 Node: Compilation Flags10517170 Ref: howto/regex compilation-flags10517283 Ref: 3f0010517283 Node: More Pattern Power10524467 Ref: howto/regex more-pattern-power10524606 Ref: 3f0210524606 Node: More Metacharacters10524971 Ref: howto/regex id210525062 Ref: 3f0310525062 Ref: howto/regex more-metacharacters10525062 Ref: 3f0110525062 Node: Grouping10529715 Ref: howto/regex grouping10529845 Ref: 3f0410529845 Node: Non-capturing and Named Groups10533330 Ref: howto/regex non-capturing-and-named-groups10533461 Ref: 3f0510533461 Node: Lookahead Assertions10538597 Ref: howto/regex lookahead-assertions10538711 Ref: 3f0610538711 Node: Modifying Strings10542378 Ref: howto/regex modifying-strings10542507 Ref: 3f0710542507 Node: Splitting Strings10543477 Ref: howto/regex splitting-strings10543575 Ref: 3f0810543575 Node: Search and Replace10545893 Ref: howto/regex search-and-replace10545991 Ref: 3f0910545991 Node: Common Problems10550479 Ref: howto/regex common-problems10550598 Ref: 3f0a10550598 Node: Use String Methods10551036 Ref: howto/regex use-string-methods10551134 Ref: 3f0b10551134 Node: match versus search10552851 Ref: howto/regex match-versus-search10552982 Ref: 3f0c10552982 Node: Greedy versus Non-Greedy10554610 Ref: howto/regex greedy-versus-non-greedy10554739 Ref: 3f0d10554739 Node: Using re VERBOSE10556662 Ref: howto/regex using-re-verbose10556763 Ref: 3f0e10556763 Node: Feedback10558290 Ref: howto/regex feedback10558383 Ref: 3f0f10558383 Node: Socket Programming HOWTO10559166 Ref: howto/sockets doc10559296 Ref: 3f1010559296 Ref: howto/sockets socket-howto10559296 Ref: 239410559296 Ref: howto/sockets socket-programming-howto10559296 Ref: 3f1110559296 Node: Sockets10559894 Ref: howto/sockets sockets10559988 Ref: 3f1210559988 Node: History10561148 Ref: howto/sockets history10561199 Ref: 3f1310561199 Node: Creating a Socket10561774 Ref: howto/sockets creating-a-socket10561891 Ref: 3f1410561891 Node: IPC10565147 Ref: howto/sockets ipc10565204 Ref: 3f1510565204 Node: Using a Socket10565650 Ref: howto/sockets using-a-socket10565773 Ref: 3f1610565773 Node: Binary Data10571912 Ref: howto/sockets binary-data10571974 Ref: 3f1710571974 Node: Disconnecting10573050 Ref: howto/sockets disconnecting10573176 Ref: 3f1810573176 Node: When Sockets Die10574652 Ref: howto/sockets when-sockets-die10574718 Ref: 3f1910574718 Node: Non-blocking Sockets10575597 Ref: howto/sockets non-blocking-sockets10575700 Ref: 3f1a10575700 Node: Sorting HOW TO10579518 Ref: howto/sorting doc10579637 Ref: 3f1b10579637 Ref: howto/sorting sorting-how-to10579637 Ref: 3f1c10579637 Ref: howto/sorting sortinghowto10579637 Ref: 12ab10579637 Node: Sorting Basics10580269 Ref: howto/sorting sorting-basics10580356 Ref: 3f1d10580356 Node: Key Functions10581158 Ref: howto/sorting key-functions10581279 Ref: 3f1e10581279 Node: Operator Module Functions10582949 Ref: howto/sorting operator-module-functions10583080 Ref: 3f1f10583080 Node: Ascending and Descending10584139 Ref: howto/sorting ascending-and-descending10584289 Ref: 3f2010584289 Node: Sort Stability and Complex Sorts10584826 Ref: howto/sorting sort-stability-and-complex-sorts10584993 Ref: 3f2110584993 Ref: Sort Stability and Complex Sorts-Footnote-110586628 Ref: Sort Stability and Complex Sorts-Footnote-210586694 Node: The Old Way Using Decorate-Sort-Undecorate10586740 Ref: howto/sorting the-old-way-using-decorate-sort-undecorate10586918 Ref: 3f2210586918 Ref: The Old Way Using Decorate-Sort-Undecorate-Footnote-110588607 Node: The Old Way Using the cmp Parameter10588667 Ref: howto/sorting the-old-way-using-the-cmp-parameter10588825 Ref: 3f2310588825 Node: Odd and Ends10591301 Ref: howto/sorting odd-and-ends10591408 Ref: 3f2410591408 Node: Unicode HOWTO10593128 Ref: howto/unicode doc10593278 Ref: 3f2510593278 Ref: howto/unicode id110593278 Ref: 3f2610593278 Ref: howto/unicode unicode-howto10593278 Ref: c3c10593278 Node: Introduction to Unicode10593680 Ref: howto/unicode introduction-to-unicode10593788 Ref: 3f2710593788 Node: Definitions10593922 Ref: howto/unicode definitions10594011 Ref: 3f2810594011 Node: Encodings10597032 Ref: howto/unicode encodings10597143 Ref: 3f2910597143 Node: References<3>10600826 Ref: howto/unicode references10600917 Ref: 3f2a10600917 Ref: References<3>-Footnote-110601794 Ref: References<3>-Footnote-210601825 Ref: References<3>-Footnote-310601865 Ref: References<3>-Footnote-410601917 Ref: References<3>-Footnote-510601963 Ref: References<3>-Footnote-610602137 Ref: References<3>-Footnote-710602194 Node: Python’s Unicode Support10602238 Ref: howto/unicode python-s-unicode-support10602387 Ref: 3f2b10602387 Node: The String Type10602756 Ref: howto/unicode the-string-type10602862 Ref: 3f2c10602862 Node: Converting to Bytes10605974 Ref: howto/unicode converting-to-bytes10606127 Ref: 3f2d10606127 Node: Unicode Literals in Python Source Code10607973 Ref: howto/unicode unicode-literals-in-python-source-code10608129 Ref: 3f2e10608129 Ref: Unicode Literals in Python Source Code-Footnote-110610236 Node: Unicode Properties10610285 Ref: howto/unicode unicode-properties10610439 Ref: 3f2f10610439 Ref: Unicode Properties-Footnote-110612206 Node: Comparing Strings10612275 Ref: howto/unicode comparing-strings10612418 Ref: 3f3010612418 Node: Unicode Regular Expressions10615265 Ref: howto/unicode unicode-regular-expressions10615403 Ref: 3f3110615403 Node: References<4>10616544 Ref: howto/unicode id210616656 Ref: 3f3210616656 Ref: References<4>-Footnote-110617443 Ref: References<4>-Footnote-210617538 Ref: References<4>-Footnote-310617590 Node: Reading and Writing Unicode Data10617659 Ref: howto/unicode reading-and-writing-unicode-data10617805 Ref: 3f3310617805 Node: Unicode filenames10621516 Ref: howto/unicode unicode-filenames10621650 Ref: 3f3410621650 Node: Tips for Writing Unicode-aware Programs10624088 Ref: howto/unicode tips-for-writing-unicode-aware-programs10624244 Ref: 3f3510624244 Node: Converting Between File Encodings10625609 Ref: howto/unicode converting-between-file-encodings10625755 Ref: 3f3610625755 Node: Files in an Unknown Encoding10626526 Ref: howto/unicode files-in-an-unknown-encoding10626672 Ref: 3f3710626672 Node: References<5>10627575 Ref: howto/unicode id310627705 Ref: 3f3810627705 Ref: References<5>-Footnote-110628315 Ref: References<5>-Footnote-210628388 Ref: References<5>-Footnote-310628493 Node: Acknowledgements<10>10628561 Ref: howto/unicode acknowledgements10628672 Ref: 3f3910628672 Node: HOWTO Fetch Internet Resources Using The urllib Package10629198 Ref: howto/urllib2 doc10629351 Ref: 3f3a10629351 Ref: howto/urllib2 howto-fetch-internet-resources-using-the-urllib-package10629351 Ref: 3f3b10629351 Ref: howto/urllib2 urllib-howto10629351 Ref: 29b510629351 Ref: HOWTO Fetch Internet Resources Using The urllib Package-Footnote-110629898 Ref: HOWTO Fetch Internet Resources Using The urllib Package-Footnote-210629953 Node: Introduction<16>10630029 Ref: howto/urllib2 introduction10630159 Ref: 3f3c10630159 Ref: Introduction<16>-Footnote-110631755 Ref: Introduction<16>-Footnote-210631828 Node: Fetching URLs10631877 Ref: howto/urllib2 fetching-urls10632038 Ref: 3f3d10632038 Node: Data10634286 Ref: howto/urllib2 data10634356 Ref: 3f3e10634356 Ref: Data-Footnote-110637009 Node: Headers10637078 Ref: howto/urllib2 headers10637148 Ref: 3f3f10637148 Ref: Headers-Footnote-110638662 Ref: Headers-Footnote-210638694 Ref: Headers-Footnote-310638908 Ref: Headers-Footnote-410639032 Node: Handling Exceptions<2>10639154 Ref: howto/urllib2 handling-exceptions10639314 Ref: 3f4110639314 Node: URLError10639799 Ref: howto/urllib2 urlerror10639884 Ref: 3f4210639884 Node: HTTPError10640438 Ref: howto/urllib2 httperror10640546 Ref: 3f4310640546 Ref: HTTPError-Footnote-110641428 Node: Error Codes10641477 Ref: howto/urllib2 error-codes10641534 Ref: 3f4410641534 Ref: Error Codes-Footnote-110646287 Node: Wrapping it Up10646336 Ref: howto/urllib2 wrapping-it-up10646427 Ref: 3f4510646427 Node: Number 110646648 Ref: howto/urllib2 number-110646724 Ref: 3f4610646724 Node: Number 210647346 Ref: howto/urllib2 number-210647422 Ref: 3f4710647422 Node: info and geturl10647956 Ref: howto/urllib2 info-and-geturl10648123 Ref: 3f4010648123 Ref: info and geturl-Footnote-110649009 Node: Openers and Handlers10649046 Ref: howto/urllib2 openers-and-handlers10649211 Ref: 3f4810649211 Node: Basic Authentication10650861 Ref: howto/urllib2 id510651018 Ref: 3f4910651018 Ref: Basic Authentication-Footnote-110654433 Node: Proxies10654506 Ref: howto/urllib2 proxies10654661 Ref: 3f4a10654661 Ref: Proxies-Footnote-110655685 Ref: Proxies-Footnote-210655992 Ref: Proxies-Footnote-310656065 Node: Sockets and Layers10656192 Ref: howto/urllib2 sockets-and-layers10656336 Ref: 3f4b10656336 Node: Footnotes10657357 Ref: howto/urllib2 footnotes10657485 Ref: 3f4c10657485 Node: Argparse Tutorial10657575 Ref: howto/argparse doc10657754 Ref: 3f4d10657754 Ref: howto/argparse argparse-tutorial10657754 Ref: 3f4e10657754 Ref: howto/argparse id110657834 Ref: 1d0510657834 Node: Concepts10658515 Ref: howto/argparse concepts10658596 Ref: 3f4f10658596 Node: The basics10660686 Ref: howto/argparse the-basics10660808 Ref: 3f5010660808 Node: Introducing Positional arguments10661984 Ref: howto/argparse introducing-positional-arguments10662128 Ref: 3f5110662128 Node: Introducing Optional arguments10665420 Ref: howto/argparse introducing-optional-arguments10665597 Ref: 3f5210665597 Node: Short options10668606 Ref: howto/argparse short-options10668686 Ref: 3f5310668686 Node: Combining Positional and Optional arguments10669492 Ref: howto/argparse combining-positional-and-optional-arguments10669667 Ref: 3f5410669667 Node: Getting a little more advanced10677916 Ref: howto/argparse getting-a-little-more-advanced10678071 Ref: 3f5510678071 Node: Conflicting options10680097 Ref: howto/argparse conflicting-options10680183 Ref: 3f5610680183 Node: Conclusion10683343 Ref: howto/argparse conclusion10683446 Ref: 3f5710683446 Node: An introduction to the ipaddress module10683711 Ref: howto/ipaddress doc10683857 Ref: 3f5810683857 Ref: howto/ipaddress an-introduction-to-the-ipaddress-module10683857 Ref: 3f5910683857 Ref: howto/ipaddress ipaddress-howto10683857 Ref: 2c1410683857 Node: Creating Address/Network/Interface objects10684600 Ref: howto/ipaddress creating-address-network-interface-objects10684771 Ref: 3f5a10684771 Node: A Note on IP Versions10685198 Ref: howto/ipaddress a-note-on-ip-versions10685324 Ref: 3f5b10685324 Node: IP Host Addresses10686107 Ref: howto/ipaddress ip-host-addresses10686259 Ref: 3f5c10686259 Node: Defining Networks10687446 Ref: howto/ipaddress defining-networks10687592 Ref: 3f5d10687592 Node: Host Interfaces10689950 Ref: howto/ipaddress host-interfaces10690070 Ref: 3f5e10690070 Node: Inspecting Address/Network/Interface Objects10691075 Ref: howto/ipaddress inspecting-address-network-interface-objects10691285 Ref: 3f5f10691285 Node: Networks as lists of Addresses10693635 Ref: howto/ipaddress networks-as-lists-of-addresses10693817 Ref: 3f6010693817 Node: Comparisons<4>10694616 Ref: howto/ipaddress comparisons10694791 Ref: 3f6110694791 Node: Using IP Addresses with other modules10695150 Ref: howto/ipaddress using-ip-addresses-with-other-modules10695343 Ref: 3f6210695343 Node: Getting more detail when instance creation fails10695774 Ref: howto/ipaddress getting-more-detail-when-instance-creation-fails10695944 Ref: 3f6310695944 Node: Argument Clinic How-To10698002 Ref: howto/clinic doc10698178 Ref: 3f6410698178 Ref: howto/clinic argument-clinic-how-to10698178 Ref: 3f6510698178 Node: The Goals Of Argument Clinic10699215 Ref: howto/clinic the-goals-of-argument-clinic10699335 Ref: 3f6610699335 Node: Basic Concepts And Usage10701701 Ref: howto/clinic basic-concepts-and-usage10701860 Ref: 3f6710701860 Node: Converting Your First Function10704295 Ref: howto/clinic converting-your-first-function10704441 Ref: 3f6810704441 Node: Advanced Topics10720589 Ref: howto/clinic advanced-topics10720702 Ref: 3f6a10720702 Node: Symbolic default values10721682 Ref: howto/clinic symbolic-default-values10721833 Ref: 3f6b10721833 Node: Renaming the C functions and variables generated by Argument Clinic10722463 Ref: howto/clinic renaming-the-c-functions-and-variables-generated-by-argument-clinic10722667 Ref: 3f6c10722667 Node: Converting functions using PyArg_UnpackTuple10724330 Ref: howto/clinic converting-functions-using-pyarg-unpacktuple10724526 Ref: 3f6d10724526 Node: Optional Groups10725071 Ref: howto/clinic optional-groups10725272 Ref: 3f6e10725272 Node: Using real Argument Clinic converters instead of “legacy converters”10729321 Ref: howto/clinic using-real-argument-clinic-converters-instead-of-legacy-converters10729487 Ref: 3f6f10729487 Ref: Using real Argument Clinic converters instead of “legacy converters”-Footnote-110738425 Node: Py_buffer10738474 Ref: howto/clinic py-buffer10738644 Ref: 3f7010738644 Node: Advanced converters10738960 Ref: howto/clinic advanced-converters10739082 Ref: 3f7110739082 Node: Parameter default values10740787 Ref: howto/clinic default-values10740922 Ref: 3f6910740922 Ref: howto/clinic parameter-default-values10740922 Ref: 3f7210740922 Node: The NULL default value10741451 Ref: howto/clinic the-null-default-value10741606 Ref: 3f7310741606 Node: Expressions specified as default values10742080 Ref: howto/clinic expressions-specified-as-default-values10742235 Ref: 3f7410742235 Node: Using a return converter10744630 Ref: howto/clinic using-a-return-converter10744789 Ref: 3f7510744789 Node: Cloning existing functions10747434 Ref: howto/clinic cloning-existing-functions10747573 Ref: 3f7610747573 Node: Calling Python code10748897 Ref: howto/clinic calling-python-code10749040 Ref: 3f7710749040 Node: Using a “self converter”10749959 Ref: howto/clinic using-a-self-converter10750102 Ref: 3f7810750102 Node: Writing a custom converter10751848 Ref: howto/clinic writing-a-custom-converter10752005 Ref: 3f7910752005 Node: Writing a custom return converter10755709 Ref: howto/clinic writing-a-custom-return-converter10755860 Ref: 3f7a10755860 Node: METH_O and METH_NOARGS10756439 Ref: howto/clinic meth-o-and-meth-noargs10756592 Ref: 3f7b10756592 Node: tp_new and tp_init functions10757163 Ref: howto/clinic tp-new-and-tp-init-functions10757325 Ref: 3f7c10757325 Node: Changing and redirecting Clinic’s output10758270 Ref: howto/clinic changing-and-redirecting-clinic-s-output10758426 Ref: 3f7d10758426 Node: The #ifdef trick10769706 Ref: howto/clinic the-ifdef-trick10769871 Ref: 3f7e10769871 Node: Using Argument Clinic in Python files10772653 Ref: howto/clinic using-argument-clinic-in-python-files10772767 Ref: 3f7f10772767 Node: Instrumenting CPython with DTrace and SystemTap10773463 Ref: howto/instrumentation doc10773591 Ref: 3f8010773591 Ref: howto/instrumentation instrumentation10773591 Ref: 50c10773591 Ref: howto/instrumentation instrumenting-cpython-with-dtrace-and-systemtap10773591 Ref: 3f8110773591 Node: Enabling the static markers10774789 Ref: howto/instrumentation enabling-the-static-markers10774929 Ref: 3f8210774929 Node: Static DTrace probes10779076 Ref: howto/instrumentation static-dtrace-probes10779249 Ref: 3f8310779249 Node: Static SystemTap markers10781690 Ref: howto/instrumentation static-systemtap-markers10781860 Ref: 3f8410781860 Node: Available static markers10783905 Ref: howto/instrumentation available-static-markers10784072 Ref: 3f8510784072 Node: SystemTap Tapsets10786617 Ref: howto/instrumentation systemtap-tapsets10786772 Ref: 3f8610786772 Node: Examples<36>10788392 Ref: howto/instrumentation examples10788514 Ref: 3f8710788514 Node: Python Frequently Asked Questions10789837 Ref: faq/index doc10789949 Ref: 3f8810789949 Ref: faq/index faq-index10789949 Ref: fae10789949 Ref: faq/index python-frequently-asked-questions10789949 Ref: 3f8910789949 Node: General Python FAQ10790273 Ref: faq/general doc10790385 Ref: 3f8a10790385 Ref: faq/general general-python-faq10790385 Ref: 3f8b10790385 Node: General Information10790497 Ref: faq/general general-information10790604 Ref: 3f8c10790604 Node: What is Python?10791593 Ref: faq/general what-is-python10791712 Ref: 3f8d10791712 Ref: What is Python?-Footnote-110792661 Node: What is the Python Software Foundation?10792713 Ref: faq/general what-is-the-python-software-foundation10792895 Ref: 3f8e10792895 Ref: What is the Python Software Foundation?-Footnote-110793499 Node: Are there copyright restrictions on the use of Python?10793545 Ref: faq/general are-there-copyright-restrictions-on-the-use-of-python10793754 Ref: 3f8f10793754 Ref: Are there copyright restrictions on the use of Python?-Footnote-110794626 Ref: Are there copyright restrictions on the use of Python?-Footnote-210794670 Node: Why was Python created in the first place?10794717 Ref: faq/general why-was-python-created-in-the-first-place10794911 Ref: 3f9010794911 Node: What is Python good for?10797243 Ref: faq/general what-is-python-good-for10797433 Ref: 3f9110797433 Ref: What is Python good for?-Footnote-110798302 Node: How does the Python version numbering scheme work?10798327 Ref: faq/general how-does-the-python-version-numbering-scheme-work10798519 Ref: 3f9210798519 Ref: How does the Python version numbering scheme work?-Footnote-110800392 Node: How do I obtain a copy of the Python source?10800441 Ref: faq/general how-do-i-obtain-a-copy-of-the-python-source10800646 Ref: 3f9310800646 Ref: How do I obtain a copy of the Python source?-Footnote-110801430 Node: How do I get documentation on Python?10801473 Ref: faq/general how-do-i-get-documentation-on-python10801686 Ref: 3f9410801686 Ref: How do I get documentation on Python?-Footnote-110802249 Node: I’ve never programmed before Is there a Python tutorial?10802280 Ref: faq/general i-ve-never-programmed-before-is-there-a-python-tutorial10802504 Ref: 3f9510802504 Ref: I’ve never programmed before Is there a Python tutorial?-Footnote-110802916 Node: Is there a newsgroup or mailing list devoted to Python?10802968 Ref: faq/general is-there-a-newsgroup-or-mailing-list-devoted-to-python10803198 Ref: 3f9610803198 Ref: Is there a newsgroup or mailing list devoted to Python?-Footnote-110804077 Ref: Is there a newsgroup or mailing list devoted to Python?-Footnote-210804138 Node: How do I get a beta test version of Python?10804208 Ref: faq/general how-do-i-get-a-beta-test-version-of-python10804431 Ref: 3f9710804431 Ref: How do I get a beta test version of Python?-Footnote-110804970 Node: How do I submit bug reports and patches for Python?10805007 Ref: faq/general how-do-i-submit-bug-reports-and-patches-for-python10805242 Ref: 3f9810805242 Ref: How do I submit bug reports and patches for Python?-Footnote-110805953 Ref: How do I submit bug reports and patches for Python?-Footnote-210806010 Node: Are there any published articles about Python that I can reference?10806047 Ref: faq/general are-there-any-published-articles-about-python-that-i-can-reference10806269 Ref: 3f9910806269 Node: Are there any books on Python?10806782 Ref: faq/general are-there-any-books-on-python10806998 Ref: 3f9a10806998 Node: Where in the world is www python org located?10807375 Ref: faq/general where-in-the-world-is-www-python-org-located10807548 Ref: 3f9b10807548 Ref: Where in the world is www python org located?-Footnote-110807834 Node: Why is it called Python?10807862 Ref: faq/general why-is-it-called-python10808060 Ref: 3f9c10808060 Ref: Why is it called Python?-Footnote-110808466 Node: Do I have to like “Monty Python’s Flying Circus”?10808517 Ref: faq/general do-i-have-to-like-monty-python-s-flying-circus10808661 Ref: 3f9d10808661 Node: Python in the real world10808811 Ref: faq/general python-in-the-real-world10808918 Ref: 3f9e10808918 Node: How stable is Python?10809298 Ref: faq/general how-stable-is-python10809422 Ref: 3f9f10809422 Ref: How stable is Python?-Footnote-110810462 Ref: How stable is Python?-Footnote-210810511 Ref: How stable is Python?-Footnote-310810553 Node: How many people are using Python?10810603 Ref: faq/general how-many-people-are-using-python10810786 Ref: 3fa010810786 Node: Have any significant projects been done in Python?10811292 Ref: faq/general have-any-significant-projects-been-done-in-python10811514 Ref: 3fa110811514 Ref: Have any significant projects been done in Python?-Footnote-110812228 Ref: Have any significant projects been done in Python?-Footnote-210812280 Ref: Have any significant projects been done in Python?-Footnote-310812308 Ref: Have any significant projects been done in Python?-Footnote-410812336 Node: What new developments are expected for Python in the future?10812367 Ref: faq/general what-new-developments-are-expected-for-python-in-the-future10812615 Ref: 3fa210812615 Ref: What new developments are expected for Python in the future?-Footnote-110813204 Node: Is it reasonable to propose incompatible changes to Python?10813265 Ref: faq/general is-it-reasonable-to-propose-incompatible-changes-to-python10813515 Ref: 3fa310813515 Ref: Is it reasonable to propose incompatible changes to Python?-Footnote-110814319 Node: Is Python a good language for beginning programmers?10814368 Ref: faq/general is-python-a-good-language-for-beginning-programmers10814549 Ref: 3fa410814549 Ref: Is Python a good language for beginning programmers?-Footnote-110818408 Ref: Is Python a good language for beginning programmers?-Footnote-210818459 Node: Programming FAQ10818521 Ref: faq/programming doc10818664 Ref: 3fa510818664 Ref: faq/programming programming-faq10818664 Ref: 3fa610818664 Node: General Questions10818899 Ref: faq/programming general-questions10818990 Ref: 3fa710818990 Node: Is there a source code level debugger with breakpoints single-stepping etc ?10819410 Ref: faq/programming is-there-a-source-code-level-debugger-with-breakpoints-single-stepping-etc10819610 Ref: 3fa810819610 Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-110821358 Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-210821408 Node: Are there tools to help find bugs or perform static analysis?10821453 Ref: faq/programming are-there-tools-to-help-find-bugs-or-perform-static-analysis10821721 Ref: 3fa910821721 Ref: Are there tools to help find bugs or perform static analysis?-Footnote-110822095 Ref: Are there tools to help find bugs or perform static analysis?-Footnote-210822127 Ref: Are there tools to help find bugs or perform static analysis?-Footnote-310822169 Ref: Are there tools to help find bugs or perform static analysis?-Footnote-410822199 Ref: Are there tools to help find bugs or perform static analysis?-Footnote-510822231 Node: How can I create a stand-alone binary from a Python script?10822272 Ref: faq/programming how-can-i-create-a-stand-alone-binary-from-a-python-script10822528 Ref: 3faa10822528 Ref: How can I create a stand-alone binary from a Python script?-Footnote-110824185 Node: Are there coding standards or a style guide for Python programs?10824239 Ref: faq/programming are-there-coding-standards-or-a-style-guide-for-python-programs10824425 Ref: 3fab10824425 Ref: Are there coding standards or a style guide for Python programs?-Footnote-110824699 Node: Core Language10824748 Ref: faq/programming core-language10824867 Ref: 3fac10824867 Node: Why am I getting an UnboundLocalError when the variable has a value?10826237 Ref: faq/programming why-am-i-getting-an-unboundlocalerror-when-the-variable-has-a-value10826424 Ref: 3fad10826424 Node: What are the rules for local and global variables in Python?10828283 Ref: faq/programming what-are-the-rules-for-local-and-global-variables-in-python10828561 Ref: 3fae10828561 Node: Why do lambdas defined in a loop with different values all return the same result?10829461 Ref: faq/programming why-do-lambdas-defined-in-a-loop-with-different-values-all-return-the-same-result10829718 Ref: 3faf10829718 Node: How do I share global variables across modules?10831627 Ref: faq/programming how-do-i-share-global-variables-across-modules10831887 Ref: 3fb010831887 Node: What are the “best practices” for using import in a module?10832690 Ref: faq/programming what-are-the-best-practices-for-using-import-in-a-module10832914 Ref: 3fb110832914 Node: Why are default values shared between objects?10835670 Ref: faq/programming why-are-default-values-shared-between-objects10835922 Ref: 3fb210835922 Node: How can I pass optional or keyword parameters from one function to another?10838310 Ref: faq/programming how-can-i-pass-optional-or-keyword-parameters-from-one-function-to-another10838555 Ref: 3fb310838555 Node: What is the difference between arguments and parameters?10839142 Ref: faq/programming faq-argument-vs-parameter10839396 Ref: 3fb410839396 Ref: faq/programming what-is-the-difference-between-arguments-and-parameters10839396 Ref: 3fb510839396 Node: Why did changing list ‘y’ also change list ‘x’?10840086 Ref: faq/programming why-did-changing-list-y-also-change-list-x10840333 Ref: 3fb610840333 Node: How do I write a function with output parameters call by reference ?10843734 Ref: faq/programming how-do-i-write-a-function-with-output-parameters-call-by-reference10843975 Ref: 3fb710843975 Node: How do you make a higher order function in Python?10846380 Ref: faq/programming how-do-you-make-a-higher-order-function-in-python10846600 Ref: 3fb810846600 Node: How do I copy an object in Python?10848174 Ref: faq/programming how-do-i-copy-an-object-in-python10848380 Ref: 3fb910848380 Node: How can I find the methods or attributes of an object?10848787 Ref: faq/programming how-can-i-find-the-methods-or-attributes-of-an-object10848990 Ref: 3fba10848990 Node: How can my code discover the name of an object?10849304 Ref: faq/programming how-can-my-code-discover-the-name-of-an-object10849524 Ref: 3fbb10849524 Node: What’s up with the comma operator’s precedence?10851144 Ref: faq/programming what-s-up-with-the-comma-operator-s-precedence10851368 Ref: 3fbc10851368 Node: Is there an equivalent of C’s “? ” ternary operator?10851926 Ref: faq/programming is-there-an-equivalent-of-c-s-ternary-operator10852159 Ref: 3fbd10852159 Node: Is it possible to write obfuscated one-liners in Python?10852754 Ref: faq/programming is-it-possible-to-write-obfuscated-one-liners-in-python10852999 Ref: 3fbe10852999 Node: What does the slash / in the parameter list of a function mean?10854478 Ref: faq/programming faq-positional-only-arguments10854656 Ref: 129d10854656 Ref: faq/programming what-does-the-slash-in-the-parameter-list-of-a-function-mean10854656 Ref: 3fbf10854656 Node: Numbers and strings10855756 Ref: faq/programming numbers-and-strings10855872 Ref: 3fc010855872 Node: How do I specify hexadecimal and octal integers?10856544 Ref: faq/programming how-do-i-specify-hexadecimal-and-octal-integers10856686 Ref: 3fc110856686 Node: Why does -22 // 10 return -3?10857335 Ref: faq/programming why-does-22-10-return-310857524 Ref: 3fc210857524 Node: How do I convert a string to a number?10858285 Ref: faq/programming how-do-i-convert-a-string-to-a-number10858464 Ref: 3fc310858464 Node: How do I convert a number to a string?10859776 Ref: faq/programming how-do-i-convert-a-number-to-a-string10859960 Ref: 3fc410859960 Node: How do I modify a string in place?10860511 Ref: faq/programming how-do-i-modify-a-string-in-place10860704 Ref: 3fc510860704 Node: How do I use strings to call functions/methods?10861560 Ref: faq/programming how-do-i-use-strings-to-call-functions-methods10861800 Ref: 3fc610861800 Node: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?10863425 Ref: faq/programming is-there-an-equivalent-to-perl-s-chomp-for-removing-trailing-newlines-from-strings10863669 Ref: 3fc710863669 Node: Is there a scanf or sscanf equivalent?10864428 Ref: faq/programming is-there-a-scanf-or-sscanf-equivalent10864699 Ref: 3fc810864699 Node: What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?10865350 Ref: faq/programming what-does-unicodedecodeerror-or-unicodeencodeerror-error-mean10865527 Ref: 3fc910865527 Node: Performance<4>10865723 Ref: faq/programming performance10865848 Ref: 3fca10865848 Node: My program is too slow How do I speed it up?10866065 Ref: faq/programming my-program-is-too-slow-how-do-i-speed-it-up10866237 Ref: 3fcb10866237 Ref: My program is too slow How do I speed it up?-Footnote-110869116 Ref: My program is too slow How do I speed it up?-Footnote-210869142 Node: What is the most efficient way to concatenate many strings together?10869207 Ref: faq/programming efficient-string-concatenation10869379 Ref: 3fcc10869379 Ref: faq/programming what-is-the-most-efficient-way-to-concatenate-many-strings-together10869379 Ref: 3fcd10869379 Node: Sequences Tuples/Lists10870349 Ref: faq/programming sequences-tuples-lists10870462 Ref: 3fce10870462 Node: How do I convert between tuples and lists?10871206 Ref: faq/programming how-do-i-convert-between-tuples-and-lists10871342 Ref: 3fcf10871342 Node: What’s a negative index?10872189 Ref: faq/programming what-s-a-negative-index10872384 Ref: 3fd010872384 Node: How do I iterate over a sequence in reverse order?10872964 Ref: faq/programming how-do-i-iterate-over-a-sequence-in-reverse-order10873158 Ref: 3fd110873158 Node: How do you remove duplicates from a list?10873507 Ref: faq/programming how-do-you-remove-duplicates-from-a-list10873719 Ref: 3fd210873719 Node: How do you remove multiple items from a list10874547 Ref: faq/programming how-do-you-remove-multiple-items-from-a-list10874744 Ref: 3fd310874744 Node: How do you make an array in Python?10875292 Ref: faq/programming how-do-you-make-an-array-in-python10875488 Ref: 3fd410875488 Node: How do I create a multidimensional list?10876472 Ref: faq/programming faq-multidimensional-list10876673 Ref: 12dc10876673 Ref: faq/programming how-do-i-create-a-multidimensional-list10876673 Ref: 3fd510876673 Ref: How do I create a multidimensional list?-Footnote-110877895 Node: How do I apply a method to a sequence of objects?10877925 Ref: faq/programming how-do-i-apply-a-method-to-a-sequence-of-objects10878170 Ref: 3fd610878170 Node: Why does a_tuple[i] += [‘item’] raise an exception when the addition works?10878364 Ref: faq/programming faq-augmented-assignment-tuple-error10878646 Ref: 111e10878646 Ref: faq/programming why-does-a-tuple-i-item-raise-an-exception-when-the-addition-works10878646 Ref: 3fd710878646 Node: I want to do a complicated sort can you do a Schwartzian Transform in Python?10881870 Ref: faq/programming i-want-to-do-a-complicated-sort-can-you-do-a-schwartzian-transform-in-python10882155 Ref: 3fd810882155 Node: How can I sort one list by values from another list?10882640 Ref: faq/programming how-can-i-sort-one-list-by-values-from-another-list10882837 Ref: 3fd910882837 Node: Objects10884051 Ref: faq/programming objects10884160 Ref: 3fda10884160 Node: What is a class?10885169 Ref: faq/programming what-is-a-class10885255 Ref: 3fdb10885255 Node: What is a method?10885981 Ref: faq/programming what-is-a-method10886089 Ref: 3fdc10886089 Node: What is self?10886398 Ref: faq/programming what-is-self10886573 Ref: 3fdd10886573 Node: How do I check if an object is an instance of a given class or of a subclass of it?10887015 Ref: faq/programming how-do-i-check-if-an-object-is-an-instance-of-a-given-class-or-of-a-subclass-of-it10887192 Ref: 3fdf10887192 Node: What is delegation?10888683 Ref: faq/programming what-is-delegation10888933 Ref: 3fe010888933 Node: How do I call a method defined in a base class from a derived class that overrides it?10890783 Ref: faq/programming how-do-i-call-a-method-defined-in-a-base-class-from-a-derived-class-that-overrides-it10891020 Ref: 3fe110891020 Node: How can I organize my code to make it easier to change the base class?10891705 Ref: faq/programming how-can-i-organize-my-code-to-make-it-easier-to-change-the-base-class10891982 Ref: 3fe210891982 Node: How do I create static class data and static class methods?10892657 Ref: faq/programming how-do-i-create-static-class-data-and-static-class-methods10892901 Ref: 3fe310892901 Node: How can I overload constructors or methods in Python?10894470 Ref: faq/programming how-can-i-overload-constructors-or-methods-in-python10894709 Ref: 3fe410894709 Node: I try to use __spam and I get an error about _SomeClassName__spam10895616 Ref: faq/programming i-try-to-use-spam-and-i-get-an-error-about-someclassname-spam10895866 Ref: 3fe510895866 Node: My class defines __del__ but it is not called when I delete the object10896667 Ref: faq/programming my-class-defines-del-but-it-is-not-called-when-i-delete-the-object10896918 Ref: 3fe610896918 Node: How do I get a list of all instances of a given class?10898892 Ref: faq/programming how-do-i-get-a-list-of-all-instances-of-a-given-class10899128 Ref: 3fe710899128 Node: Why does the result of id appear to be not unique?10899469 Ref: faq/programming why-does-the-result-of-id-appear-to-be-not-unique10899626 Ref: 3fe810899626 Node: Modules<3>10900518 Ref: faq/programming modules10900596 Ref: 3fe910900596 Node: How do I create a pyc file?10901136 Ref: faq/programming how-do-i-create-a-pyc-file10901257 Ref: 3fea10901257 Ref: How do I create a pyc file?-Footnote-110903838 Node: How do I find the current module name?10903887 Ref: faq/programming how-do-i-find-the-current-module-name10904072 Ref: 3feb10904072 Node: How can I have modules that mutually import each other?10904630 Ref: faq/programming how-can-i-have-modules-that-mutually-import-each-other10904852 Ref: 3fec10904852 Node: __import__ ‘x y z’ returns ; how do I get z?10906738 Ref: faq/programming import-x-y-z-returns-module-x-how-do-i-get-z10907018 Ref: 3fed10907018 Node: When I edit an imported module and reimport it the changes don’t show up Why does this happen?10907308 Ref: faq/programming when-i-edit-an-imported-module-and-reimport-it-the-changes-don-t-show-up-why-does-this-happen10907524 Ref: 3fee10907524 Node: Design and History FAQ10908971 Ref: faq/design doc10909121 Ref: 3fef10909121 Ref: faq/design design-and-history-faq10909121 Ref: 3ff010909121 Node: Why does Python use indentation for grouping of statements?10911165 Ref: faq/design why-does-python-use-indentation-for-grouping-of-statements10911359 Ref: 3ff110911359 Node: Why am I getting strange results with simple arithmetic operations?10913061 Ref: faq/design why-am-i-getting-strange-results-with-simple-arithmetic-operations10913314 Ref: 3ff210913314 Node: Why are floating-point calculations so inaccurate?10913489 Ref: faq/design why-are-floating-point-calculations-so-inaccurate10913716 Ref: 3ff310913716 Node: Why are Python strings immutable?10915254 Ref: faq/design why-are-python-strings-immutable10915485 Ref: 3ff410915485 Node: Why must ‘self’ be used explicitly in method definitions and calls?10916088 Ref: faq/design why-must-self-be-used-explicitly-in-method-definitions-and-calls10916318 Ref: 3ff510916318 Ref: faq/design why-self10916318 Ref: 3fde10916318 Node: Why can’t I use an assignment in an expression?10918808 Ref: faq/design id110919109 Ref: 3ff610919109 Ref: faq/design why-can-t-i-use-an-assignment-in-an-expression10919109 Ref: f0c10919109 Ref: Why can’t I use an assignment in an expression?-Footnote-110919481 Node: Why does Python use methods for some functionality e g list index but functions for other e g len list ?10919530 Ref: faq/design why-does-python-use-methods-for-some-functionality-e-g-list-index-but-functions-for-other-e-g-len-list10919822 Ref: 3ff710919822 Node: Why is join a string method instead of a list or tuple method?10921161 Ref: faq/design why-is-join-a-string-method-instead-of-a-list-or-tuple-method10921428 Ref: 3ff810921428 Node: How fast are exceptions?10923239 Ref: faq/design how-fast-are-exceptions10923457 Ref: 3ff910923457 Node: Why isn’t there a switch or case statement in Python?10924270 Ref: faq/design why-isn-t-there-a-switch-or-case-statement-in-python10924532 Ref: 3ffa10924532 Ref: Why isn’t there a switch or case statement in Python?-Footnote-110925905 Node: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?10925954 Ref: faq/design can-t-you-emulate-threads-in-the-interpreter-instead-of-relying-on-an-os-specific-thread-implementation10926242 Ref: 3ffb10926242 Ref: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?-Footnote-110926889 Node: Why can’t lambda expressions contain statements?10926945 Ref: faq/design why-can-t-lambda-expressions-contain-statements10927242 Ref: 3ffc10927242 Node: Can Python be compiled to machine code C or some other language?10928107 Ref: faq/design can-python-be-compiled-to-machine-code-c-or-some-other-language10928328 Ref: 3ffd10928328 Ref: Can Python be compiled to machine code C or some other language?-Footnote-110928763 Ref: Can Python be compiled to machine code C or some other language?-Footnote-210928790 Ref: Can Python be compiled to machine code C or some other language?-Footnote-310928821 Node: How does Python manage memory?10928856 Ref: faq/design how-does-python-manage-memory10929098 Ref: 3ffe10929098 Ref: How does Python manage memory?-Footnote-110930767 Ref: How does Python manage memory?-Footnote-210930797 Node: Why doesn’t CPython use a more traditional garbage collection scheme?10930825 Ref: faq/design why-doesn-t-cpython-use-a-more-traditional-garbage-collection-scheme10931051 Ref: 3fff10931051 Node: Why isn’t all memory freed when CPython exits?10931967 Ref: faq/design why-isn-t-all-memory-freed-when-cpython-exits10932212 Ref: 400010932212 Node: Why are there separate tuple and list data types?10932907 Ref: faq/design why-are-there-separate-tuple-and-list-data-types10933118 Ref: 400110933118 Node: How are lists implemented in CPython?10934352 Ref: faq/design how-are-lists-implemented-in-cpython10934559 Ref: 400210934559 Node: How are dictionaries implemented in CPython?10935300 Ref: faq/design how-are-dictionaries-implemented-in-cpython10935496 Ref: 400310935496 Node: Why must dictionary keys be immutable?10936447 Ref: faq/design why-must-dictionary-keys-be-immutable10936653 Ref: 400410936653 Node: Why doesn’t list sort return the sorted list?10940856 Ref: faq/design why-doesn-t-list-sort-return-the-sorted-list10941077 Ref: 400510941077 Node: How do you specify and enforce an interface spec in Python?10941921 Ref: faq/design how-do-you-specify-and-enforce-an-interface-spec-in-python10942125 Ref: 400610942125 Node: Why is there no goto?10944458 Ref: faq/design why-is-there-no-goto10944670 Ref: 400710944670 Node: Why can’t raw strings r-strings end with a backslash?10945748 Ref: faq/design why-can-t-raw-strings-r-strings-end-with-a-backslash10945976 Ref: 400810945976 Node: Why doesn’t Python have a “with” statement for attribute assignments?10947077 Ref: faq/design why-doesn-t-python-have-a-with-statement-for-attribute-assignments10947346 Ref: 400910947346 Node: Why are colons required for the if/while/def/class statements?10949547 Ref: faq/design why-are-colons-required-for-the-if-while-def-class-statements10949821 Ref: 400a10949821 Node: Why does Python allow commas at the end of lists and tuples?10950566 Ref: faq/design why-does-python-allow-commas-at-the-end-of-lists-and-tuples10950756 Ref: 400b10950756 Node: Library and Extension FAQ10951857 Ref: faq/library doc10952015 Ref: 400c10952015 Ref: faq/library library-and-extension-faq10952015 Ref: 400d10952015 Node: General Library Questions10952264 Ref: faq/library general-library-questions10952372 Ref: 400e10952372 Node: How do I find a module or application to perform task X?10952884 Ref: faq/library how-do-i-find-a-module-or-application-to-perform-task-x10953067 Ref: 400f10953067 Ref: How do I find a module or application to perform task X?-Footnote-110953654 Ref: How do I find a module or application to perform task X?-Footnote-210953679 Node: Where is the math py socket py regex py etc source file?10953710 Ref: faq/library where-is-the-math-py-socket-py-regex-py-etc-source-file10953951 Ref: 401010953951 Node: How do I make a Python script executable on Unix?10954735 Ref: faq/library how-do-i-make-a-python-script-executable-on-unix10954965 Ref: 401110954965 Node: Is there a curses/termcap package for Python?10956442 Ref: faq/library is-there-a-curses-termcap-package-for-python10956665 Ref: 401210956665 Ref: Is there a curses/termcap package for Python?-Footnote-110957504 Ref: Is there a curses/termcap package for Python?-Footnote-210957563 Node: Is there an equivalent to C’s onexit in Python?10957612 Ref: faq/library is-there-an-equivalent-to-c-s-onexit-in-python10957822 Ref: 401310957822 Node: Why don’t my signal handlers work?10958042 Ref: faq/library why-don-t-my-signal-handlers-work10958198 Ref: 401410958198 Node: Common tasks10958522 Ref: faq/library common-tasks10958646 Ref: 401510958646 Node: How do I test a Python program or component?10958844 Ref: faq/library how-do-i-test-a-python-program-or-component10958993 Ref: 401610958993 Node: How do I create documentation from doc strings?10960944 Ref: faq/library how-do-i-create-documentation-from-doc-strings10961143 Ref: 401710961143 Ref: How do I create documentation from doc strings?-Footnote-110961519 Ref: How do I create documentation from doc strings?-Footnote-210961558 Node: How do I get a single keypress at a time?10961588 Ref: faq/library how-do-i-get-a-single-keypress-at-a-time10961734 Ref: 401810961734 Node: Threads10961980 Ref: faq/library threads10962098 Ref: 401910962098 Node: How do I program using threads?10962426 Ref: faq/library how-do-i-program-using-threads10962545 Ref: 401a10962545 Node: None of my threads seem to run why?10962978 Ref: faq/library none-of-my-threads-seem-to-run-why10963163 Ref: 401b10963163 Node: How do I parcel out work among a bunch of worker threads?10964712 Ref: faq/library how-do-i-parcel-out-work-among-a-bunch-of-worker-threads10964918 Ref: 401c10964918 Node: What kinds of global value mutation are thread-safe?10967518 Ref: faq/library what-kinds-of-global-value-mutation-are-thread-safe10967739 Ref: 401d10967739 Node: Can’t we get rid of the Global Interpreter Lock?10969245 Ref: faq/library can-t-we-get-rid-of-the-global-interpreter-lock10969400 Ref: 401e10969400 Ref: Can’t we get rid of the Global Interpreter Lock?-Footnote-110972091 Node: Input and Output<2>10972151 Ref: faq/library input-and-output10972285 Ref: 401f10972285 Node: How do I delete a file? And other file questions…10972920 Ref: faq/library how-do-i-delete-a-file-and-other-file-questions10973057 Ref: 402010973057 Node: How do I copy a file?10974307 Ref: faq/library how-do-i-copy-a-file10974488 Ref: 402110974488 Node: How do I read or write binary data?10974699 Ref: faq/library how-do-i-read-or-write-binary-data10974897 Ref: 402210974897 Node: I can’t seem to use os read on a pipe created with os popen ; why?10976094 Ref: faq/library i-can-t-seem-to-use-os-read-on-a-pipe-created-with-os-popen-why10976309 Ref: 402310976309 Node: How do I access the serial RS232 port?10976830 Ref: faq/library how-do-i-access-the-serial-rs232-port10977072 Ref: 402410977072 Node: Why doesn’t closing sys stdout stdin stderr really close it?10977384 Ref: faq/library why-doesn-t-closing-sys-stdout-stdin-stderr-really-close-it10977549 Ref: 402510977549 Node: Network/Internet Programming10978776 Ref: faq/library network-internet-programming10978912 Ref: 402610978912 Node: What WWW tools are there for Python?10979369 Ref: faq/library what-www-tools-are-there-for-python10979528 Ref: 402710979528 Node: How can I mimic CGI form submission METHOD=POST ?10980112 Ref: faq/library how-can-i-mimic-cgi-form-submission-method-post10980334 Ref: 402810980334 Node: What module should I use to help with generating HTML?10981438 Ref: faq/library what-module-should-i-use-to-help-with-generating-html10981664 Ref: 402910981664 Ref: What module should I use to help with generating HTML?-Footnote-110981909 Node: How do I send mail from a Python script?10981961 Ref: faq/library how-do-i-send-mail-from-a-python-script10982196 Ref: 402a10982196 Node: How do I avoid blocking in the connect method of a socket?10983537 Ref: faq/library how-do-i-avoid-blocking-in-the-connect-method-of-a-socket10983709 Ref: 402b10983709 Ref: How do I avoid blocking in the connect method of a socket?-Footnote-110984961 Node: Databases10985001 Ref: faq/library databases10985142 Ref: 402c10985142 Node: Are there any interfaces to database packages in Python?10985303 Ref: faq/library are-there-any-interfaces-to-database-packages-in-python10985464 Ref: 402d10985464 Ref: Are there any interfaces to database packages in Python?-Footnote-110985970 Node: How do you implement persistent objects in Python?10986027 Ref: faq/library how-do-you-implement-persistent-objects-in-python10986188 Ref: 402e10986188 Node: Mathematics and Numerics10986589 Ref: faq/library mathematics-and-numerics10986693 Ref: 402f10986693 Node: How do I generate random numbers in Python?10986816 Ref: faq/library how-do-i-generate-random-numbers-in-python10986920 Ref: 403010986920 Node: Extending/Embedding FAQ10987869 Ref: faq/extending doc10988026 Ref: 403110988026 Ref: faq/extending extending-embedding-faq10988026 Ref: 403210988026 Node: Can I create my own functions in C?10989514 Ref: faq/extending can-i-create-my-own-functions-in-c10989655 Ref: 403310989655 Node: Can I create my own functions in C++?10990014 Ref: faq/extending id110990210 Ref: 403410990210 Node: Writing C is hard; are there any alternatives?10990597 Ref: faq/extending c-wrapper-software10990811 Ref: 403510990811 Ref: faq/extending writing-c-is-hard-are-there-any-alternatives10990811 Ref: 403610990811 Ref: Writing C is hard; are there any alternatives?-Footnote-110991580 Ref: Writing C is hard; are there any alternatives?-Footnote-210991606 Ref: Writing C is hard; are there any alternatives?-Footnote-310991673 Ref: Writing C is hard; are there any alternatives?-Footnote-410991701 Ref: Writing C is hard; are there any alternatives?-Footnote-510991759 Ref: Writing C is hard; are there any alternatives?-Footnote-610991795 Ref: Writing C is hard; are there any alternatives?-Footnote-710991851 Node: How can I execute arbitrary Python statements from C?10991890 Ref: faq/extending how-can-i-execute-arbitrary-python-statements-from-c10992124 Ref: 403710992124 Node: How can I evaluate an arbitrary Python expression from C?10992670 Ref: faq/extending how-can-i-evaluate-an-arbitrary-python-expression-from-c10992905 Ref: 403810992905 Node: How do I extract C values from a Python object?10993221 Ref: faq/extending how-do-i-extract-c-values-from-a-python-object10993468 Ref: 403910993468 Node: How do I use Py_BuildValue to create a tuple of arbitrary length?10994707 Ref: faq/extending how-do-i-use-py-buildvalue-to-create-a-tuple-of-arbitrary-length10994939 Ref: 403a10994939 Node: How do I call an object’s method from C?10995146 Ref: faq/extending how-do-i-call-an-object-s-method-from-c10995416 Ref: 403b10995416 Node: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?10996641 Ref: faq/extending how-do-i-catch-the-output-from-pyerr-print-or-anything-that-prints-to-stdout-stderr10996896 Ref: 403c10996896 Node: How do I access a module written in Python from C?10998109 Ref: faq/extending how-do-i-access-a-module-written-in-python-from-c10998368 Ref: 403d10998368 Node: How do I interface to C++ objects from Python?10999202 Ref: faq/extending how-do-i-interface-to-c-objects-from-python10999438 Ref: 403e10999438 Node: I added a module using the Setup file and the make fails; why?11000009 Ref: faq/extending i-added-a-module-using-the-setup-file-and-the-make-fails-why11000223 Ref: 403f11000223 Node: How do I debug an extension?11000573 Ref: faq/extending how-do-i-debug-an-extension11000825 Ref: 404011000825 Node: I want to compile a Python module on my Linux system but some files are missing Why?11001376 Ref: faq/extending i-want-to-compile-a-python-module-on-my-linux-system-but-some-files-are-missing-why11001628 Ref: 404111001628 Node: How do I tell “incomplete input” from “invalid input”?11002112 Ref: faq/extending how-do-i-tell-incomplete-input-from-invalid-input11002404 Ref: 404211002404 Node: How do I find undefined g++ symbols __builtin_new or __pure_virtual?11008516 Ref: faq/extending how-do-i-find-undefined-g-symbols-builtin-new-or-pure-virtual11008834 Ref: 404311008834 Node: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?11009222 Ref: faq/extending can-i-create-an-object-class-with-some-methods-implemented-in-c-and-others-in-python-e-g-through-inheritance11009469 Ref: 404411009469 Node: Python on Windows FAQ11010022 Ref: faq/windows doc11010180 Ref: 404511010180 Ref: faq/windows python-on-windows-faq11010180 Ref: 404611010180 Ref: faq/windows windows-faq11010180 Ref: 404711010180 Node: How do I run a Python program under Windows?11010696 Ref: faq/windows faq-run-program-under-windows11010847 Ref: 404811010847 Ref: faq/windows how-do-i-run-a-python-program-under-windows11010847 Ref: 404911010847 Node: How do I make Python scripts executable?11014439 Ref: faq/windows how-do-i-make-python-scripts-executable11014647 Ref: 404a11014647 Node: Why does Python sometimes take so long to start?11015209 Ref: faq/windows why-does-python-sometimes-take-so-long-to-start11015422 Ref: 404b11015422 Node: How do I make an executable from a Python script?11016301 Ref: faq/windows how-do-i-make-an-executable-from-a-python-script11016508 Ref: 404c11016508 Ref: How do I make an executable from a Python script?-Footnote-111016930 Ref: How do I make an executable from a Python script?-Footnote-211016982 Node: Is a * pyd file the same as a DLL?11017013 Ref: faq/windows is-a-pyd-file-the-same-as-a-dll11017222 Ref: 404d11017222 Node: How can I embed Python into a Windows application?11018219 Ref: faq/windows how-can-i-embed-python-into-a-windows-application11018443 Ref: 404e11018443 Node: How do I keep editors from inserting tabs into my Python source?11022981 Ref: faq/windows how-do-i-keep-editors-from-inserting-tabs-into-my-python-source11023218 Ref: 404f11023218 Ref: How do I keep editors from inserting tabs into my Python source?-Footnote-111024095 Node: How do I check for a keypress without blocking?11024144 Ref: faq/windows how-do-i-check-for-a-keypress-without-blocking11024322 Ref: 405011024322 Node: Graphic User Interface FAQ11024671 Ref: faq/gui doc11024855 Ref: 405111024855 Ref: faq/gui graphic-user-interface-faq11024855 Ref: 405211024855 Node: General GUI Questions11025097 Ref: faq/gui general-gui-questions11025246 Ref: 405311025246 Node: What platform-independent GUI toolkits exist for Python?11025305 Ref: faq/gui what-platform-independent-gui-toolkits-exist-for-python11025516 Ref: 405411025516 Node: Tkinter11025935 Ref: faq/gui tkinter11026053 Ref: 405511026053 Ref: Tkinter-Footnote-111026522 Ref: Tkinter-Footnote-211026564 Node: wxWidgets11026591 Ref: faq/gui wxwidgets11026720 Ref: 405711026720 Ref: wxWidgets-Footnote-111027582 Node: Qt11027615 Ref: faq/gui qt11027741 Ref: 405611027741 Ref: Qt-Footnote-111028217 Ref: Qt-Footnote-211028276 Ref: Qt-Footnote-311028310 Ref: Qt-Footnote-411028374 Ref: Qt-Footnote-511028440 Node: Gtk+11028477 Ref: faq/gui gtk11028598 Ref: 405811028598 Ref: Gtk+-Footnote-111028926 Ref: Gtk+-Footnote-211028976 Ref: Gtk+-Footnote-311029029 Node: Kivy11029057 Ref: faq/gui kivy11029180 Ref: 405911029180 Ref: Kivy-Footnote-111029540 Node: FLTK11029566 Ref: faq/gui fltk11029691 Ref: 405a11029691 Ref: FLTK-Footnote-111029906 Ref: FLTK-Footnote-211029934 Node: OpenGL11029972 Ref: faq/gui opengl11030084 Ref: 405b11030084 Ref: OpenGL-Footnote-111030192 Node: What platform-specific GUI toolkits exist for Python?11030232 Ref: faq/gui what-platform-specific-gui-toolkits-exist-for-python11030439 Ref: 405c11030439 Ref: What platform-specific GUI toolkits exist for Python?-Footnote-111030893 Node: Tkinter questions11030934 Ref: faq/gui tkinter-questions11031076 Ref: 405d11031076 Node: How do I freeze Tkinter applications?11031342 Ref: faq/gui how-do-i-freeze-tkinter-applications11031493 Ref: 405e11031493 Node: Can I have Tk events handled while waiting for I/O?11032440 Ref: faq/gui can-i-have-tk-events-handled-while-waiting-for-i-o11032650 Ref: 405f11032650 Node: I can’t get key bindings to work in Tkinter why?11033125 Ref: faq/gui i-can-t-get-key-bindings-to-work-in-tkinter-why11033289 Ref: 406011033289 Node: “Why is Python Installed on my Computer?” FAQ11033841 Ref: faq/installed doc11033995 Ref: 406111033995 Ref: faq/installed why-is-python-installed-on-my-computer-faq11033995 Ref: 406211033995 Node: What is Python?<2>11034219 Ref: faq/installed what-is-python11034370 Ref: 406311034370 Ref: What is Python?<2>-Footnote-111034851 Node: Why is Python installed on my machine?11034903 Ref: faq/installed why-is-python-installed-on-my-machine11035083 Ref: 406411035083 Node: Can I delete Python?11036171 Ref: faq/installed can-i-delete-python11036324 Ref: 406511036324 Node: Glossary11037052 Ref: glossary doc11037172 Ref: 406611037172 Ref: glossary glossary11037172 Ref: e9211037172 Ref: glossary id111037172 Ref: 406711037172 Ref: glossary term-011037197 Ref: eac11037197 Ref: glossary term-111037360 Ref: ead11037360 Ref: glossary term-2to311037754 Ref: 406811037754 Ref: glossary term-abstract-base-class11038168 Ref: b3311038168 Ref: glossary term-annotation11039005 Ref: 406a11039005 Ref: glossary term-argument11039576 Ref: 11ca11039576 Ref: glossary term-asynchronous-context-manager11041009 Ref: 64111041009 Ref: glossary term-asynchronous-generator11041243 Ref: 11a911041243 Ref: glossary term-asynchronous-generator-iterator11041968 Ref: 335c11041968 Ref: glossary term-asynchronous-iterable11042718 Ref: 64011042718 Ref: glossary term-asynchronous-iterator11042941 Ref: 64511042941 Ref: glossary term-attribute11043357 Ref: 406d11043357 Ref: glossary term-awaitable11043557 Ref: 51911043557 Ref: glossary term-bdfl11043754 Ref: 406e11043754 Ref: glossary term-binary-file11043851 Ref: 196611043851 Ref: glossary term-bytes-like-object11044296 Ref: 5e811044296 Ref: glossary term-bytecode11045281 Ref: 61411045281 Ref: glossary term-callback11046011 Ref: 229611046011 Ref: glossary term-class11046129 Ref: 12ac11046129 Ref: glossary term-class-variable11046294 Ref: 406f11046294 Ref: glossary term-coercion11046440 Ref: 407011046440 Ref: glossary term-complex-number11047079 Ref: 407111047079 Ref: glossary term-context-manager11047850 Ref: 56811047850 Ref: glossary term-context-variable11048051 Ref: 407211048051 Ref: glossary term-contiguous11048509 Ref: 136011048509 Ref: glossary term-coroutine11049052 Ref: 1a611049052 Ref: glossary term-coroutine-function11049375 Ref: 63f11049375 Ref: glossary term-cpython11049689 Ref: 10d711049689 Ref: glossary term-decorator11049942 Ref: 28311049942 Ref: glossary term-descriptor11050654 Ref: 12b011050654 Ref: glossary term-dictionary11051453 Ref: 407311051453 Ref: glossary term-dictionary-comprehension11051659 Ref: 407411051659 Ref: glossary term-dictionary-view11052005 Ref: 15f411052005 Ref: glossary term-docstring11052451 Ref: 125e11052451 Ref: glossary term-duck-typing11052842 Ref: 406911052842 Ref: glossary term-eafp11053546 Ref: 1c2011053546 Ref: glossary term-expression11053992 Ref: 335011053992 Ref: glossary term-extension-module11054505 Ref: 407611054505 Ref: glossary term-f-string11054633 Ref: 15b11054633 Ref: glossary term-file-object11054828 Ref: b4211054828 Ref: glossary term-file-like-object11055604 Ref: 192811055604 Ref: glossary term-finder11055666 Ref: 115f11055666 Ref: glossary term-floor-division11056057 Ref: eb211056057 Ref: glossary term-function11056433 Ref: 11c911056433 Ref: glossary term-function-annotation11056740 Ref: ef111056740 Ref: glossary term-future11057337 Ref: 68311057337 Ref: glossary term-garbage-collection11057815 Ref: f9f11057815 Ref: glossary term-generator11058135 Ref: 9a211058135 Ref: glossary term-generator-iterator11058651 Ref: 45711058651 Ref: glossary term-generator-expression11059049 Ref: 407711059049 Ref: glossary term-generic-function11059430 Ref: 1ca11059430 Ref: glossary term-gil11059789 Ref: bea11059789 Ref: glossary term-global-interpreter-lock11059840 Ref: 50611059840 Ref: glossary term-hash-based-pyc11061017 Ref: 407811061017 Ref: glossary term-hashable11061231 Ref: 10c811061231 Ref: glossary term-idle11062146 Ref: 407911062146 Ref: glossary term-immutable11062324 Ref: eb611062324 Ref: glossary term-import-path11062668 Ref: 116211062668 Ref: glossary term-importing11063007 Ref: 115111063007 Ref: glossary term-importer11063128 Ref: 116111063128 Ref: glossary term-interactive11063254 Ref: 407a11063254 Ref: glossary term-interpreted11063676 Ref: 407b11063676 Ref: glossary term-interpreter-shutdown11064169 Ref: 76311064169 Ref: glossary term-iterable11064903 Ref: bac11064903 Ref: glossary term-iterator11066098 Ref: 112e11066098 Ref: glossary term-key-function11067320 Ref: 6e011067320 Ref: glossary term-keyword-argument11068491 Ref: 5c411068491 Ref: glossary term-lambda11068541 Ref: 33f811068541 Ref: glossary term-lbyl11068774 Ref: 407511068774 Ref: glossary term-list11069441 Ref: 407c11069441 Ref: glossary term-list-comprehension11069623 Ref: 407d11069623 Ref: glossary term-loader11070041 Ref: 116011070041 Ref: glossary term-magic-method11070315 Ref: 407e11070315 Ref: glossary term-mapping11070387 Ref: b3911070387 Ref: glossary term-meta-path-finder11070754 Ref: 9b111070754 Ref: glossary term-metaclass11071051 Ref: 201411071051 Ref: glossary term-method11071791 Ref: 406c11071791 Ref: glossary term-method-resolution-order11072101 Ref: 12ae11072101 Ref: glossary term-module11072378 Ref: 115011072378 Ref: glossary term-module-spec11072641 Ref: 336011072641 Ref: glossary term-mro11072807 Ref: 257811072807 Ref: glossary term-mutable11072859 Ref: ebe11072859 Ref: glossary term-named-tuple11072982 Ref: aa311072982 Ref: glossary term-namespace11074149 Ref: 407f11074149 Ref: glossary term-namespace-package11074904 Ref: 115811074904 Ref: glossary term-nested-scope11075227 Ref: 129511075227 Ref: glossary term-new-style-class11075715 Ref: 196e11075715 Ref: glossary term-object11076041 Ref: 408011076041 Ref: glossary term-package11076205 Ref: 115511076205 Ref: glossary term-parameter11076478 Ref: 11d211076478 Ref: glossary positional-only-parameter11077021 Ref: 2a711077021 Ref: glossary keyword-only-parameter11077421 Ref: 2ac11077421 Ref: glossary term-path-entry11078932 Ref: 117511078932 Ref: glossary term-path-entry-finder11079086 Ref: 9b211079086 Ref: glossary term-path-entry-hook11079409 Ref: 117711079409 Ref: glossary term-path-based-finder11079601 Ref: 116511079601 Ref: glossary term-path-like-object11079736 Ref: 36a11079736 Ref: glossary term-pep11080369 Ref: 408111080369 Ref: glossary term-portion11081023 Ref: 115a11081023 Ref: glossary term-positional-argument11081184 Ref: 5c511081184 Ref: glossary term-provisional-api11081237 Ref: 34811081237 Ref: glossary term-provisional-package11082241 Ref: 98011082241 Ref: glossary term-python-300011082300 Ref: 408211082300 Ref: glossary term-pythonic11082493 Ref: 408311082493 Ref: glossary term-qualified-name11083133 Ref: 10ca11083133 Ref: glossary term-reference-count11083978 Ref: 387411083978 Ref: glossary term-regular-package11084420 Ref: 115711084420 Ref: glossary term-slots11084587 Ref: 34cc11084587 Ref: glossary term-sequence11084933 Ref: ebc11084933 Ref: glossary term-set-comprehension11085940 Ref: 408411085940 Ref: glossary term-single-dispatch11086257 Ref: 1cb11086257 Ref: glossary term-slice11086408 Ref: 12aa11086408 Ref: glossary term-special-method11086733 Ref: 338b11086733 Ref: glossary term-statement11087013 Ref: 184711087013 Ref: glossary term-text-encoding11087256 Ref: 12a511087256 Ref: glossary term-text-file11087325 Ref: f3a11087325 Ref: glossary term-triple-quoted-string11087847 Ref: 408511087847 Ref: glossary term-type11088347 Ref: 408611088347 Ref: glossary term-type-alias11088580 Ref: 408711088580 Ref: glossary term-type-hint11089245 Ref: 406b11089245 Ref: glossary term-universal-newlines11089831 Ref: 5f411089831 Ref: glossary term-variable-annotation11090205 Ref: 61f11090205 Ref: glossary term-virtual-environment11090830 Ref: fa811090830 Ref: glossary term-virtual-machine11091139 Ref: 247d11091139 Ref: glossary term-zen-of-python11091305 Ref: 408811091305 Ref: Glossary-Footnote-111091571 Ref: Glossary-Footnote-211091620 Ref: Glossary-Footnote-311091669 Ref: Glossary-Footnote-411091718 Ref: Glossary-Footnote-511091767 Ref: Glossary-Footnote-611091816 Ref: Glossary-Footnote-711091865 Ref: Glossary-Footnote-811091914 Ref: Glossary-Footnote-911091963 Ref: Glossary-Footnote-1011092012 Ref: Glossary-Footnote-1111092051 Ref: Glossary-Footnote-1211092101 Ref: Glossary-Footnote-1311092151 Ref: Glossary-Footnote-1411092201 Ref: Glossary-Footnote-1511092233 Ref: Glossary-Footnote-1611092283 Ref: Glossary-Footnote-1711092333 Ref: Glossary-Footnote-1811092383 Ref: Glossary-Footnote-1911092433 Ref: Glossary-Footnote-2011092483 Ref: Glossary-Footnote-2111092533 Ref: Glossary-Footnote-2211092583 Ref: Glossary-Footnote-2311092633 Ref: Glossary-Footnote-2411092692 Ref: Glossary-Footnote-2511092742 Ref: Glossary-Footnote-2611092792 Ref: Glossary-Footnote-2711092842 Ref: Glossary-Footnote-2811092892 Ref: Glossary-Footnote-2911092942 Ref: Glossary-Footnote-3011092992 Ref: Glossary-Footnote-3111093042 Ref: Glossary-Footnote-3211093092 Ref: Glossary-Footnote-3311093142 Ref: Glossary-Footnote-3411093192 Ref: Glossary-Footnote-3511093242 Ref: Glossary-Footnote-3611093292 Node: About these documents11093342 Ref: about doc11093446 Ref: 408911093446 Ref: about about-these-documents11093446 Ref: 408a11093446 Ref: About these documents-Footnote-111094351 Ref: About these documents-Footnote-211094400 Ref: About these documents-Footnote-311094431 Ref: About these documents-Footnote-411094472 Node: Contributors to the Python Documentation11094513 Ref: about contributors-to-the-python-documentation11094611 Ref: 408b11094611 Ref: Contributors to the Python Documentation-Footnote-111095070 Node: Dealing with Bugs11095131 Ref: bugs doc11095236 Ref: 408c11095236 Ref: bugs dealing-with-bugs11095236 Ref: 408d11095236 Ref: bugs reporting-bugs11095236 Ref: 38d711095236 Node: Documentation bugs11095779 Ref: bugs documentation-bugs11095890 Ref: 408f11095890 Ref: Documentation bugs-Footnote-111096837 Ref: Documentation bugs-Footnote-211096982 Ref: Documentation bugs-Footnote-311097027 Node: Using the Python issue tracker11097103 Ref: bugs using-the-python-issue-tracker11097270 Ref: 409111097270 Ref: bugs using-the-tracker11097270 Ref: 409011097270 Ref: Using the Python issue tracker-Footnote-111099676 Ref: Using the Python issue tracker-Footnote-211099739 Node: Getting started contributing to Python yourself11099823 Ref: bugs contributing-to-python11099963 Ref: 408e11099963 Ref: bugs getting-started-contributing-to-python-yourself11099963 Ref: 409211099963 Ref: Getting started contributing to Python yourself-Footnote-111100482 Ref: Getting started contributing to Python yourself-Footnote-211100519 Node: Copyright11100595 Ref: copyright doc11100698 Ref: 409311100698 Ref: copyright copyright11100698 Ref: 409411100698 Ref: copyright core-mentorship-mailing-list11100698 Ref: 409511100698 Node: History and License11101213 Ref: license doc11101341 Ref: 409711101341 Ref: license history-and-license11101341 Ref: 409611101341 Ref: license id111101341 Ref: 409811101341 Node: History of the software11101551 Ref: license history-of-the-software11101699 Ref: 409911101699 Node: Terms and conditions for accessing or otherwise using Python11106236 Ref: license terms-and-conditions-for-accessing-or-otherwise-using-python11106448 Ref: 409a11106448 Node: PSF LICENSE AGREEMENT FOR PYTHON 3 8 911107613 Ref: license psf-license11107800 Ref: 409b11107800 Ref: license psf-license-agreement-for-python-release11107800 Ref: 409e11107800 Node: BEOPEN COM LICENSE AGREEMENT FOR PYTHON 2 011110469 Ref: license beopen-com-license-agreement-for-python-2-011110704 Ref: 409f11110704 Node: CNRI LICENSE AGREEMENT FOR PYTHON 1 6 111113412 Ref: license cnri-license-agreement-for-python-1-6-111113659 Ref: 40a011113659 Node: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 211117837 Ref: license cwi-license-agreement-for-python-0-9-0-through-1-211118107 Ref: 40a111118107 Node: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 8 9 DOCUMENTATION11119377 Ref: license bsd011119599 Ref: 409c11119599 Ref: license zero-clause-bsd-license-for-code-in-the-python-release-documentation11119599 Ref: 40a211119599 Node: Licenses and Acknowledgements for Incorporated Software11120401 Ref: license licenses-and-acknowledgements-for-incorporated-software11120581 Ref: 40a311120581 Ref: license otherlicenses11120581 Ref: 409d11120581 Node: Mersenne Twister11121216 Ref: license mersenne-twister11121343 Ref: 40a411121343 Node: Sockets<2>11123617 Ref: license sockets11123781 Ref: 40a511123781 Node: Asynchronous socket services11125615 Ref: license asynchronous-socket-services11125780 Ref: 40a611125780 Node: Cookie management11127000 Ref: license cookie-management11127172 Ref: 40a711127172 Node: Execution tracing11128389 Ref: license execution-tracing11128564 Ref: 40a811128564 Node: UUencode and UUdecode functions11129824 Ref: license uuencode-and-uudecode-functions11130008 Ref: 40a911130008 Node: XML Remote Procedure Calls11131590 Ref: license xml-remote-procedure-calls11131767 Ref: 40aa11131767 Node: test_epoll11133292 Ref: license test-epoll11133451 Ref: 40ab11133451 Node: Select kqueue11134711 Ref: license select-kqueue11134853 Ref: 40ac11134853 Node: SipHash2411136407 Ref: license siphash2411136554 Ref: 40ad11136554 Node: strtod and dtoa11137737 Ref: license strtod-and-dtoa11137878 Ref: 40ae11137878 Node: OpenSSL11139227 Ref: license openssl11139364 Ref: 40af11139364 Node: expat11146911 Ref: license expat11147039 Ref: 40b011147039 Node: libffi11148439 Ref: license libffi11148567 Ref: 40b111148567 Node: zlib<3>11149910 Ref: license zlib11150040 Ref: 40b211150040 Node: cfuhash11151273 Ref: license cfuhash11151405 Ref: 40b311151405 Node: libmpdec11153222 Ref: license libmpdec11153366 Ref: 40b411153366 Node: W3C C14N test suite11154930 Ref: license w3c-c14n-test-suite11155058 Ref: 40b511155058 Node: Distributing Python Modules Legacy version11157006 Ref: distutils/index doc11157165 Ref: 40b611157165 Ref: distutils/index distributing-python-modules-legacy-version11157165 Ref: 40b711157165 Ref: distutils/index distutils-index11157165 Ref: 7f811157165 Ref: Distributing Python Modules Legacy version-Footnote-111158649 Node: An Introduction to Distutils11158715 Ref: distutils/introduction doc11158855 Ref: 40b811158855 Ref: distutils/introduction an-introduction-to-distutils11158855 Ref: 40b911158855 Ref: distutils/introduction distutils-intro11158855 Ref: 40ba11158855 Node: Concepts & Terminology11159610 Ref: distutils/introduction concepts-terminology11159725 Ref: 40bb11159725 Ref: distutils/introduction distutils-concepts11159725 Ref: 40bc11159725 Node: A Simple Example<2>11160929 Ref: distutils/introduction a-simple-example11161079 Ref: 40bd11161079 Ref: distutils/introduction distutils-simple-example11161079 Ref: 40be11161079 Node: General Python terminology11164930 Ref: distutils/introduction general-python-terminology11165088 Ref: 40c011165088 Ref: distutils/introduction python-terms11165088 Ref: 40c111165088 Node: Distutils-specific terminology11167083 Ref: distutils/introduction distutils-specific-terminology11167213 Ref: 40c211167213 Ref: distutils/introduction distutils-term11167213 Ref: 40c311167213 Node: Writing the Setup Script11168370 Ref: distutils/setupscript doc11168555 Ref: 40c411168555 Ref: distutils/setupscript setup-script11168555 Ref: 40bf11168555 Ref: distutils/setupscript writing-the-setup-script11168555 Ref: 40c511168555 Node: Listing whole packages11171950 Ref: distutils/setupscript listing-packages11172068 Ref: 40c711172068 Ref: distutils/setupscript listing-whole-packages11172068 Ref: 40c811172068 Node: Listing individual modules11174528 Ref: distutils/setupscript listing-individual-modules11174683 Ref: 40c911174683 Ref: distutils/setupscript listing-modules11174683 Ref: 40ca11174683 Node: Describing extension modules11175492 Ref: distutils/setupscript describing-extension-modules11175673 Ref: 40cb11175673 Ref: distutils/setupscript describing-extensions11175673 Ref: 40cc11175673 Node: Extension names and packages11177412 Ref: distutils/setupscript extension-names-and-packages11177536 Ref: 40ce11177536 Node: Extension source files11178635 Ref: distutils/setupscript extension-source-files11178788 Ref: 40cf11178788 Node: Preprocessor options11180184 Ref: distutils/setupscript preprocessor-options11180324 Ref: 40d011180324 Node: Library options11183342 Ref: distutils/setupscript library-options11183473 Ref: 40d111183473 Node: Other options11184451 Ref: distutils/setupscript other-options11184553 Ref: 40d211184553 Node: Relationships between Distributions and Packages11185708 Ref: distutils/setupscript relationships-between-distributions-and-packages11185881 Ref: 40d311185881 Node: Installing Scripts11189259 Ref: distutils/setupscript distutils-installing-scripts11189427 Ref: 40d411189427 Ref: distutils/setupscript installing-scripts11189427 Ref: 40d511189427 Node: Installing Package Data11190534 Ref: distutils/setupscript distutils-installing-package-data11190681 Ref: 40d611190681 Ref: distutils/setupscript installing-package-data11190681 Ref: 40d711190681 Node: Installing Additional Files11192388 Ref: distutils/setupscript distutils-additional-files11192537 Ref: 40d811192537 Ref: distutils/setupscript installing-additional-files11192537 Ref: 40d911192537 Node: Additional meta-data11194426 Ref: distutils/setupscript additional-meta-data11194578 Ref: 40da11194578 Ref: distutils/setupscript meta-data11194578 Ref: 40c611194578 Ref: Additional meta-data-Footnote-111201903 Node: Debugging the setup script11201940 Ref: distutils/setupscript debug-setup-script11202056 Ref: 40db11202056 Ref: distutils/setupscript debugging-the-setup-script11202056 Ref: 40dc11202056 Node: Writing the Setup Configuration File11203131 Ref: distutils/configfile doc11203318 Ref: 40dd11203318 Ref: distutils/configfile setup-config11203318 Ref: 40de11203318 Ref: distutils/configfile writing-the-setup-configuration-file11203318 Ref: 40df11203318 Ref: distutils/configfile distutils-build-ext-inplace11206527 Ref: 40e011206527 Ref: Writing the Setup Configuration File-Footnote-111208986 Node: Creating a Source Distribution11209100 Ref: distutils/sourcedist doc11209291 Ref: 40e211209291 Ref: distutils/sourcedist creating-a-source-distribution11209291 Ref: 40e311209291 Ref: distutils/sourcedist source-dist11209291 Ref: 40e411209291 Node: Specifying the files to distribute11212131 Ref: distutils/sourcedist manifest11212265 Ref: 38bb11212265 Ref: distutils/sourcedist specifying-the-files-to-distribute11212265 Ref: 40e511212265 Node: Manifest-related options11218240 Ref: distutils/sourcedist manifest-options11218374 Ref: 40e711218374 Ref: distutils/sourcedist manifest-related-options11218374 Ref: 40e811218374 Node: Creating Built Distributions11219477 Ref: distutils/builtdist doc11219650 Ref: 40e911219650 Ref: distutils/builtdist built-dist11219650 Ref: 40ea11219650 Ref: distutils/builtdist creating-built-distributions11219650 Ref: 40eb11219650 Node: Creating RPM packages11227258 Ref: distutils/builtdist creating-rpm-packages11227380 Ref: 40ec11227380 Ref: distutils/builtdist creating-rpms11227380 Ref: 40ed11227380 Node: Creating Windows Installers11234970 Ref: distutils/builtdist creating-windows-installers11235127 Ref: 40ee11235127 Ref: distutils/builtdist creating-wininst11235127 Ref: 40ef11235127 Node: Cross-compiling on Windows11237359 Ref: distutils/builtdist cross-compile-windows11237524 Ref: 40f011237524 Ref: distutils/builtdist cross-compiling-on-windows11237524 Ref: 40f111237524 Node: The Postinstallation script11239210 Ref: distutils/builtdist postinstallation-script11239300 Ref: 40f211239300 Ref: distutils/builtdist the-postinstallation-script11239300 Ref: 40f311239300 Ref: distutils/builtdist directory_created11240205 Ref: 40f411240205 Ref: distutils/builtdist file_created11240244 Ref: 40f511240244 Ref: distutils/builtdist get_special_folder_path11240595 Ref: 40f611240595 Ref: distutils/builtdist create_shortcut11241485 Ref: 40f711241485 Node: Vista User Access Control UAC11242202 Ref: distutils/builtdist vista-user-access-control-uac11242331 Ref: 40f811242331 Node: Distutils Examples11242784 Ref: distutils/examples doc11242946 Ref: 40f911242946 Ref: distutils/examples distutils-examples11242946 Ref: 40fa11242946 Ref: distutils/examples id111242946 Ref: 40fb11242946 Ref: Distutils Examples-Footnote-111243829 Node: Pure Python distribution by module11243885 Ref: distutils/examples pure-mod11244018 Ref: 40fc11244018 Ref: distutils/examples pure-python-distribution-by-module11244018 Ref: 40fd11244018 Node: Pure Python distribution by package11245802 Ref: distutils/examples pure-pkg11245967 Ref: 40fe11245967 Ref: distutils/examples pure-python-distribution-by-package11245967 Ref: 40ff11245967 Node: Single extension module11249736 Ref: distutils/examples single-ext11249885 Ref: 410011249885 Ref: distutils/examples single-extension-module11249885 Ref: 410111249885 Node: Checking a package11251000 Ref: distutils/examples checking-a-package11251134 Ref: 410211251134 Ref: Checking a package-Footnote-111252781 Node: Reading the metadata11252821 Ref: distutils/examples reading-the-metadata11252923 Ref: 410311252923 Node: Extending Distutils11254562 Ref: distutils/extending doc11254713 Ref: 410411254713 Ref: distutils/extending docutils11254713 Ref: 410511254713 Ref: distutils/extending extending-distutils11254713 Ref: 103611254713 Ref: distutils/extending id111254713 Ref: 410611254713 Node: Integrating new commands11255996 Ref: distutils/extending integrating-new-commands11256114 Ref: 410811256114 Node: Adding new distribution types11259014 Ref: distutils/extending adding-new-distribution-types11259132 Ref: 410911259132 Node: Command Reference11259586 Ref: distutils/commandref doc11259732 Ref: 410a11259732 Ref: distutils/commandref command-reference11259732 Ref: 410b11259732 Ref: distutils/commandref reference11259732 Ref: 410c11259732 Node: Installing modules the install command family11260248 Ref: distutils/commandref install-cmd11260404 Ref: 410d11260404 Ref: distutils/commandref installing-modules-the-install-command-family11260404 Ref: 410e11260404 Node: install_data11260730 Ref: distutils/commandref install-data11260848 Ref: 410f11260848 Ref: distutils/commandref install-data-cmd11260848 Ref: 411011260848 Node: install_scripts11260971 Ref: distutils/commandref install-scripts11261089 Ref: 411111261089 Ref: distutils/commandref install-scripts-cmd11261089 Ref: 411211261089 Node: Creating a source distribution the sdist command11261213 Ref: distutils/commandref creating-a-source-distribution-the-sdist-command11261369 Ref: 411311261369 Ref: distutils/commandref sdist-cmd11261369 Ref: 40e611261369 Node: API Reference11264141 Ref: distutils/apiref doc11264259 Ref: 411411264259 Ref: distutils/apiref api-reference11264259 Ref: 411511264259 Ref: distutils/apiref id111264259 Ref: 411611264259 Ref: API Reference-Footnote-111270182 Node: distutils core — Core Distutils functionality11270282 Ref: distutils/apiref distutils-core-core-distutils-functionality11270432 Ref: 411711270432 Ref: distutils/apiref module-distutils core11270432 Ref: 5411270432 Ref: distutils/apiref distutils core setup11270839 Ref: 38b811270839 Ref: distutils/apiref distutils core run_setup11277750 Ref: 411a11277750 Ref: distutils/apiref distutils core Extension11280170 Ref: 40cd11280170 Ref: distutils/apiref distutils core Distribution11287594 Ref: 411811287594 Ref: distutils/apiref distutils core Command11288111 Ref: 411911288111 Ref: distutils core — Core Distutils functionality-Footnote-111288310 Ref: distutils core — Core Distutils functionality-Footnote-211288347 Node: distutils ccompiler — CCompiler base class11288396 Ref: distutils/apiref distutils-ccompiler-ccompiler-base-class11288598 Ref: 411b11288598 Ref: distutils/apiref module-distutils ccompiler11288598 Ref: 3c11288598 Ref: distutils/apiref distutils ccompiler gen_lib_options11289091 Ref: 411d11289091 Ref: distutils/apiref distutils ccompiler gen_preprocess_options11289577 Ref: 411e11289577 Ref: distutils/apiref distutils ccompiler get_default_compiler11290243 Ref: 411f11290243 Ref: distutils/apiref distutils ccompiler new_compiler11290712 Ref: 412011290712 Ref: distutils/apiref distutils ccompiler show_compilers11291512 Ref: 412111291512 Ref: distutils/apiref distutils ccompiler CCompiler11291705 Ref: 411c11291705 Ref: distutils/apiref distutils ccompiler CCompiler add_include_dir11293142 Ref: 412211293142 Ref: distutils/apiref distutils ccompiler CCompiler set_include_dirs11293444 Ref: 412311293444 Ref: distutils/apiref distutils ccompiler CCompiler add_library11293917 Ref: 412411293917 Ref: distutils/apiref distutils ccompiler CCompiler set_libraries11294704 Ref: 412511294704 Ref: distutils/apiref distutils ccompiler CCompiler add_library_dir11294999 Ref: 412611294999 Ref: distutils/apiref distutils ccompiler CCompiler set_library_dirs11295405 Ref: 412711295405 Ref: distutils/apiref distutils ccompiler CCompiler add_runtime_library_dir11295646 Ref: 412811295646 Ref: distutils/apiref distutils ccompiler CCompiler set_runtime_library_dirs11295807 Ref: 412911295807 Ref: distutils/apiref distutils ccompiler CCompiler define_macro11296093 Ref: 412a11296093 Ref: distutils/apiref distutils ccompiler CCompiler undefine_macro11296461 Ref: 412b11296461 Ref: distutils/apiref distutils ccompiler CCompiler add_link_object11296984 Ref: 412c11296984 Ref: distutils/apiref distutils ccompiler CCompiler set_link_objects11297267 Ref: 412d11297267 Ref: distutils/apiref distutils ccompiler CCompiler detect_language11297710 Ref: 412e11297710 Ref: distutils/apiref distutils ccompiler CCompiler find_library_file11297954 Ref: 412f11297954 Ref: distutils/apiref distutils ccompiler CCompiler has_function11298363 Ref: 413011298363 Ref: distutils/apiref distutils ccompiler CCompiler library_dir_option11298765 Ref: 413111298765 Ref: distutils/apiref distutils ccompiler CCompiler library_option11298920 Ref: 413211298920 Ref: distutils/apiref distutils ccompiler CCompiler runtime_library_dir_option11299091 Ref: 413311299091 Ref: distutils/apiref distutils ccompiler CCompiler set_executables11299262 Ref: 413411299262 Ref: distutils/apiref distutils ccompiler CCompiler compile11300759 Ref: 413611300759 Ref: distutils/apiref distutils ccompiler CCompiler create_static_lib11303541 Ref: 413711303541 Ref: distutils/apiref distutils ccompiler CCompiler link11304825 Ref: 413811304825 Ref: distutils/apiref distutils ccompiler CCompiler link_executable11307485 Ref: 413911307485 Ref: distutils/apiref distutils ccompiler CCompiler link_shared_lib11307975 Ref: 413a11307975 Ref: distutils/apiref distutils ccompiler CCompiler link_shared_object11308517 Ref: 413b11308517 Ref: distutils/apiref distutils ccompiler CCompiler preprocess11309083 Ref: 413c11309083 Ref: distutils/apiref distutils ccompiler CCompiler executable_filename11309970 Ref: 413d11309970 Ref: distutils/apiref distutils ccompiler CCompiler library_filename11310274 Ref: 413e11310274 Ref: distutils/apiref distutils ccompiler CCompiler object_filenames11310679 Ref: 413f11310679 Ref: distutils/apiref distutils ccompiler CCompiler shared_object_filename11310915 Ref: 414011310915 Ref: distutils/apiref distutils ccompiler CCompiler execute11311110 Ref: 414111311110 Ref: distutils/apiref distutils ccompiler CCompiler spawn11311394 Ref: 414311311394 Ref: distutils/apiref distutils ccompiler CCompiler mkpath11311543 Ref: 414411311543 Ref: distutils/apiref distutils ccompiler CCompiler move_file11311721 Ref: 414611311721 Ref: distutils/apiref distutils ccompiler CCompiler announce11311859 Ref: 414811311859 Ref: distutils/apiref distutils ccompiler CCompiler warn11311965 Ref: 414911311965 Ref: distutils/apiref distutils ccompiler CCompiler debug_print11312054 Ref: 414a11312054 Node: distutils unixccompiler — Unix C Compiler11312243 Ref: distutils/apiref distutils-unixccompiler-unix-c-compiler11312443 Ref: 414b11312443 Ref: distutils/apiref module-distutils unixccompiler11312443 Ref: 6411312443 Node: distutils msvccompiler — Microsoft Compiler11313210 Ref: distutils/apiref distutils-msvccompiler-microsoft-compiler11313409 Ref: 414c11313409 Ref: distutils/apiref module-distutils msvccompiler11313409 Ref: 6011313409 Node: distutils bcppcompiler — Borland Compiler11314397 Ref: distutils/apiref distutils-bcppcompiler-borland-compiler11314597 Ref: 414d11314597 Ref: distutils/apiref module-distutils bcppcompiler11314597 Ref: 3b11314597 Node: distutils cygwincompiler — Cygwin Compiler11314831 Ref: distutils/apiref distutils-cygwincompiler-cygwin-compiler11315032 Ref: 414e11315032 Ref: distutils/apiref module-distutils cygwinccompiler11315032 Ref: 5511315032 Node: distutils archive_util — Archiving utilities11315414 Ref: distutils/apiref distutils-archive-util-archiving-utilities11315614 Ref: 414f11315614 Ref: distutils/apiref module-distutils archive_util11315614 Ref: 3a11315614 Ref: distutils/apiref distutils archive_util make_archive11315825 Ref: 415011315825 Ref: distutils/apiref distutils archive_util make_tarball11316737 Ref: 415111316737 Ref: distutils/apiref distutils archive_util make_zipfile11317525 Ref: 415211317525 Node: distutils dep_util — Dependency checking11318039 Ref: distutils/apiref distutils-dep-util-dependency-checking11318243 Ref: 415311318243 Ref: distutils/apiref module-distutils dep_util11318243 Ref: 5711318243 Ref: distutils/apiref distutils dep_util newer11318532 Ref: 415411318532 Ref: distutils/apiref distutils dep_util newer_pairwise11318872 Ref: 415511318872 Ref: distutils/apiref distutils dep_util newer_group11319194 Ref: 415611319194 Node: distutils dir_util — Directory tree operations11320095 Ref: distutils/apiref distutils-dir-util-directory-tree-operations11320299 Ref: 415711320299 Ref: distutils/apiref module-distutils dir_util11320299 Ref: 5811320299 Ref: distutils/apiref distutils dir_util mkpath11320505 Ref: 414511320505 Ref: distutils/apiref distutils dir_util create_tree11321114 Ref: 415811321114 Ref: distutils/apiref distutils dir_util copy_tree11321675 Ref: 415911321675 Ref: distutils/apiref distutils dir_util remove_tree11323154 Ref: 415b11323154 Ref: distutils dir_util — Directory tree operations-Footnote-111323468 Node: distutils file_util — Single file operations11323514 Ref: distutils/apiref distutils-file-util-single-file-operations11323732 Ref: 415c11323732 Ref: distutils/apiref module-distutils file_util11323732 Ref: 5d11323732 Ref: distutils/apiref distutils file_util copy_file11323929 Ref: 415a11323929 Ref: distutils/apiref distutils file_util move_file11325349 Ref: 414711325349 Ref: distutils/apiref distutils file_util write_file11325760 Ref: 415d11325760 Node: distutils util — Miscellaneous other utility functions11325947 Ref: distutils/apiref distutils-util-miscellaneous-other-utility-functions11326158 Ref: 415e11326158 Ref: distutils/apiref module-distutils util11326158 Ref: 6511326158 Ref: distutils/apiref distutils util get_platform11326396 Ref: 415f11326396 Ref: distutils/apiref distutils util convert_path11328104 Ref: 416011328104 Ref: distutils/apiref distutils util change_root11328649 Ref: 416111328649 Ref: distutils/apiref distutils util check_environ11328974 Ref: 416211328974 Ref: distutils/apiref distutils util subst_vars11329393 Ref: 416311329393 Ref: distutils/apiref distutils util split_quoted11330209 Ref: 413511330209 Ref: distutils/apiref distutils util execute11330784 Ref: 414211330784 Ref: distutils/apiref distutils util strtobool11331304 Ref: 416411331304 Ref: distutils/apiref distutils util byte_compile11331657 Ref: 416511331657 Ref: distutils/apiref distutils util rfc822_escape11333685 Ref: 416611333685 Ref: distutils util — Miscellaneous other utility functions-Footnote-111333978 Ref: distutils util — Miscellaneous other utility functions-Footnote-211334027 Ref: distutils util — Miscellaneous other utility functions-Footnote-311334076 Ref: distutils util — Miscellaneous other utility functions-Footnote-411334125 Node: distutils dist — The Distribution class11334173 Ref: distutils/apiref distutils-dist-the-distribution-class11334381 Ref: 416711334381 Ref: distutils/apiref module-distutils dist11334381 Ref: 5911334381 Node: distutils extension — The Extension class11334623 Ref: distutils/apiref distutils-extension-the-extension-class11334815 Ref: 416811334815 Ref: distutils/apiref module-distutils extension11334815 Ref: 5b11334815 Node: distutils debug — Distutils debug mode11335034 Ref: distutils/apiref distutils-debug-distutils-debug-mode11335226 Ref: 416911335226 Ref: distutils/apiref module-distutils debug11335226 Ref: 5611335226 Node: distutils errors — Distutils exceptions11335369 Ref: distutils/apiref distutils-errors-distutils-exceptions11335586 Ref: 416a11335586 Ref: distutils/apiref module-distutils errors11335586 Ref: 5a11335586 Node: distutils fancy_getopt — Wrapper around the standard getopt module11336086 Ref: distutils/apiref distutils-fancy-getopt-wrapper-around-the-standard-getopt-module11336304 Ref: 416b11336304 Ref: distutils/apiref module-distutils fancy_getopt11336304 Ref: 5c11336304 Ref: distutils/apiref distutils fancy_getopt fancy_getopt11337010 Ref: 416c11337010 Ref: distutils/apiref distutils fancy_getopt wrap_text11337668 Ref: 416e11337668 Ref: distutils/apiref distutils fancy_getopt FancyGetopt11337776 Ref: 416d11337776 Ref: distutils/apiref distutils fancy_getopt FancyGetopt getopt11338341 Ref: 416f11338341 Ref: distutils/apiref distutils fancy_getopt FancyGetopt get_option_order11338943 Ref: 417011338943 Ref: distutils/apiref distutils fancy_getopt FancyGetopt generate_help11339187 Ref: 417111339187 Node: distutils filelist — The FileList class11339467 Ref: distutils/apiref distutils-filelist-the-filelist-class11339690 Ref: 417211339690 Ref: distutils/apiref module-distutils filelist11339690 Ref: 5e11339690 Node: distutils log — Simple PEP 282-style logging11339911 Ref: distutils/apiref distutils-log-simple-pep-282-style-logging11340105 Ref: 417311340105 Ref: distutils/apiref module-distutils log11340105 Ref: 5f11340105 Node: distutils spawn — Spawn a sub-process11340226 Ref: distutils/apiref distutils-spawn-spawn-a-sub-process11340435 Ref: 417411340435 Ref: distutils/apiref module-distutils spawn11340435 Ref: 6111340435 Node: distutils sysconfig — System configuration information11340774 Ref: distutils/apiref distutils-sysconfig-system-configuration-information11340979 Ref: 417511340979 Ref: distutils/apiref module-distutils sysconfig11340979 Ref: 6211340979 Ref: distutils/apiref distutils sysconfig PREFIX11341822 Ref: 417611341822 Ref: distutils/apiref distutils sysconfig EXEC_PREFIX11341916 Ref: 417711341916 Ref: distutils/apiref distutils sysconfig get_config_var11342020 Ref: 417811342020 Ref: distutils/apiref distutils sysconfig get_config_vars11342185 Ref: 417911342185 Ref: distutils/apiref distutils sysconfig get_config_h_filename11342639 Ref: 417a11342639 Ref: distutils/apiref distutils sysconfig get_makefile_filename11342999 Ref: 417b11342999 Ref: distutils/apiref distutils sysconfig get_python_inc11343377 Ref: 417c11343377 Ref: distutils/apiref distutils sysconfig get_python_lib11343908 Ref: 417d11343908 Ref: distutils/apiref distutils sysconfig customize_compiler11344713 Ref: 417e11344713 Ref: distutils/apiref distutils sysconfig set_python_build11345383 Ref: 417f11345383 Node: distutils text_file — The TextFile class11345706 Ref: distutils/apiref distutils-text-file-the-textfile-class11345916 Ref: 418011345916 Ref: distutils/apiref module-distutils text_file11345916 Ref: 6311345916 Ref: distutils/apiref distutils text_file TextFile11346229 Ref: 418111346229 Ref: distutils/apiref distutils text_file TextFile open11350747 Ref: 418511350747 Ref: distutils/apiref distutils text_file TextFile close11350894 Ref: 418411350894 Ref: distutils/apiref distutils text_file TextFile warn11351058 Ref: 418211351058 Ref: distutils/apiref distutils text_file TextFile readline11351568 Ref: 418611351568 Ref: distutils/apiref distutils text_file TextFile readlines11352250 Ref: 418711352250 Ref: distutils/apiref distutils text_file TextFile unreadline11352457 Ref: 418311352457 Node: distutils version — Version number classes11353086 Ref: distutils/apiref distutils-version-version-number-classes11353300 Ref: 418811353300 Ref: distutils/apiref module-distutils version11353300 Ref: 6611353300 Node: distutils cmd — Abstract base class for Distutils commands11353413 Ref: distutils/apiref distutils-cmd-abstract-base-class-for-distutils-commands11353617 Ref: 418911353617 Ref: distutils/apiref module-distutils cmd11353617 Ref: 3d11353617 Ref: distutils/apiref distutils cmd Command11353829 Ref: 410711353829 Node: Creating a new Distutils command11354907 Ref: distutils/apiref creating-a-new-distutils-command11355118 Ref: 418d11355118 Ref: distutils/apiref distutils cmd Command initialize_options11355987 Ref: 418a11355987 Ref: distutils/apiref distutils cmd Command finalize_options11356435 Ref: 418b11356435 Ref: distutils/apiref distutils cmd Command run11356931 Ref: 418c11356931 Ref: distutils/apiref distutils cmd Command sub_commands11357357 Ref: 418e11357357 Node: distutils command — Individual Distutils commands11358348 Ref: distutils/apiref distutils-command-individual-distutils-commands11358551 Ref: 418f11358551 Ref: distutils/apiref module-distutils command11358551 Ref: 3e11358551 Node: distutils command bdist — Build a binary installer11358678 Ref: distutils/apiref distutils-command-bdist-build-a-binary-installer11358919 Ref: 419011358919 Ref: distutils/apiref module-distutils command bdist11358919 Ref: 3f11358919 Node: distutils command bdist_packager — Abstract base class for packagers11359048 Ref: distutils/apiref distutils-command-bdist-packager-abstract-base-class-for-packagers11359299 Ref: 419111359299 Ref: distutils/apiref module-distutils command bdist_packager11359299 Ref: 4211359299 Node: distutils command bdist_dumb — Build a “dumb” installer11359464 Ref: distutils/apiref distutils-command-bdist-dumb-build-a-dumb-installer11359737 Ref: 419211359737 Ref: distutils/apiref module-distutils command bdist_dumb11359737 Ref: 4011359737 Node: distutils command bdist_msi — Build a Microsoft Installer binary package11359880 Ref: distutils/apiref distutils-command-bdist-msi-build-a-microsoft-installer-binary-package11360167 Ref: 419311360167 Ref: distutils/apiref module-distutils command bdist_msi11360167 Ref: 4111360167 Ref: distutils/apiref distutils command bdist_msi bdist_msi11360340 Ref: 419411360340 Ref: distutils command bdist_msi — Build a Microsoft Installer binary package-Footnote-111360783 Node: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM11360853 Ref: distutils/apiref distutils-command-bdist-rpm-build-a-binary-distribution-as-a-redhat-rpm-and-srpm11361140 Ref: 419511361140 Ref: distutils/apiref module-distutils command bdist_rpm11361140 Ref: 4311361140 Node: distutils command bdist_wininst — Build a Windows installer11361333 Ref: distutils/apiref distutils-command-bdist-wininst-build-a-windows-installer11361601 Ref: 419611361601 Ref: distutils/apiref module-distutils command bdist_wininst11361601 Ref: 4411361601 Node: distutils command sdist — Build a source distribution11361821 Ref: distutils/apiref distutils-command-sdist-build-a-source-distribution11362061 Ref: 419711362061 Ref: distutils/apiref module-distutils command sdist11362061 Ref: 5311362061 Node: distutils command build — Build all files of a package11362196 Ref: distutils/apiref distutils-command-build-build-all-files-of-a-package11362442 Ref: 419811362442 Ref: distutils/apiref module-distutils command build11362442 Ref: 4511362442 Node: distutils command build_clib — Build any C libraries in a package11362579 Ref: distutils/apiref distutils-command-build-clib-build-any-c-libraries-in-a-package11362835 Ref: 419911362835 Ref: distutils/apiref module-distutils command build_clib11362835 Ref: 4611362835 Node: distutils command build_ext — Build any extensions in a package11362994 Ref: distutils/apiref distutils-command-build-ext-build-any-extensions-in-a-package11363261 Ref: 419a11363261 Ref: distutils/apiref module-distutils command build_ext11363261 Ref: 4711363261 Node: distutils command build_py — Build the py/ pyc files of a package11363416 Ref: distutils/apiref distutils-command-build-py-build-the-py-pyc-files-of-a-package11363682 Ref: 419b11363682 Ref: distutils/apiref module-distutils command build_py11363682 Ref: 4811363682 Ref: distutils/apiref distutils command build_py build_py11363843 Ref: 419c11363843 Ref: distutils/apiref distutils command build_py build_py_2to311363891 Ref: 419d11363891 Node: distutils command build_scripts — Build the scripts of a package11364508 Ref: distutils/apiref distutils-command-build-scripts-build-the-scripts-of-a-package11364763 Ref: 419e11364763 Ref: distutils/apiref module-distutils command build_scripts11364763 Ref: 4911364763 Node: distutils command clean — Clean a package build area11364920 Ref: distutils/apiref distutils-command-clean-clean-a-package-build-area11365166 Ref: 419f11365166 Ref: distutils/apiref module-distutils command clean11365166 Ref: 4b11365166 Node: distutils command config — Perform package configuration11365610 Ref: distutils/apiref distutils-command-config-perform-package-configuration11365837 Ref: 41a011365837 Ref: distutils/apiref module-distutils command config11365837 Ref: 4c11365837 Node: distutils command install — Install a package11365978 Ref: distutils/apiref distutils-command-install-install-a-package11366219 Ref: 41a111366219 Ref: distutils/apiref module-distutils command install11366219 Ref: 4d11366219 Node: distutils command install_data — Install data files from a package11366338 Ref: distutils/apiref distutils-command-install-data-install-data-files-from-a-package11366600 Ref: 41a211366600 Ref: distutils/apiref module-distutils command install_data11366600 Ref: 4e11366600 Node: distutils command install_headers — Install C/C++ header files from a package11366761 Ref: distutils/apiref distutils-command-install-headers-install-c-c-header-files-from-a-package11367046 Ref: 41a311367046 Ref: distutils/apiref module-distutils command install_headers11367046 Ref: 4f11367046 Node: distutils command install_lib — Install library files from a package11367229 Ref: distutils/apiref distutils-command-install-lib-install-library-files-from-a-package11367519 Ref: 41a411367519 Ref: distutils/apiref module-distutils command install_lib11367519 Ref: 5011367519 Node: distutils command install_scripts — Install script files from a package11367684 Ref: distutils/apiref distutils-command-install-scripts-install-script-files-from-a-package11367973 Ref: 41a511367973 Ref: distutils/apiref module-distutils command install_scripts11367973 Ref: 5111367973 Node: distutils command register — Register a module with the Python Package Index11368144 Ref: distutils/apiref distutils-command-register-register-a-module-with-the-python-package-index11368423 Ref: 41a611368423 Ref: distutils/apiref module-distutils command register11368423 Ref: 5211368423 Ref: distutils command register — Register a module with the Python Package Index-Footnote-111368770 Node: distutils command check — Check the meta-data of a package11368819 Ref: distutils/apiref distutils-command-check-check-the-meta-data-of-a-package11369016 Ref: 41a711369016 Ref: distutils/apiref module-distutils command check11369016 Ref: 4a11369016 Node: Installing Python Modules Legacy version11369358 Ref: install/index doc11369517 Ref: 41a811369517 Ref: install/index install-index11369517 Ref: 7f711369517 Ref: install/index installing-python-modules-legacy-version11369517 Ref: 41a911369517 Ref: Installing Python Modules Legacy version-Footnote-111370713 Node: Introduction<17>11370779 Ref: install/index inst-intro11370907 Ref: 41aa11370907 Ref: install/index introduction11370907 Ref: 41ab11370907 Node: Distutils based source distributions11371871 Ref: install/index distutils-based-source-distributions11371960 Ref: 41ac11371960 Ref: install/index inst-new-standard11371960 Ref: 41ad11371960 Node: Standard Build and Install11373247 Ref: install/index inst-standard-install11373406 Ref: 41ae11373406 Ref: install/index standard-build-and-install11373406 Ref: 41af11373406 Node: Platform variations11373805 Ref: install/index inst-platform-variations11373916 Ref: 41b011373916 Ref: install/index platform-variations11373916 Ref: 41b111373916 Node: Splitting the job up11374831 Ref: install/index inst-splitting-up11374969 Ref: 41b211374969 Ref: install/index splitting-the-job-up11374969 Ref: 41b311374969 Node: How building works11376273 Ref: install/index how-building-works11376414 Ref: 41b411376414 Ref: install/index inst-how-build-works11376414 Ref: 41b511376414 Node: How installation works11378143 Ref: install/index how-installation-works11378255 Ref: 41b711378255 Ref: install/index inst-how-install-works11378255 Ref: 41b811378255 Node: Alternate Installation11383053 Ref: install/index alternate-installation11383215 Ref: 41bb11383215 Ref: install/index inst-alt-install11383215 Ref: 41b911383215 Node: Alternate installation the user scheme11384903 Ref: install/index alternate-installation-the-user-scheme11385047 Ref: 41bc11385047 Ref: install/index inst-alt-install-user11385047 Ref: ff411385047 Node: Alternate installation the home scheme11387444 Ref: install/index alternate-installation-the-home-scheme11387642 Ref: 41bd11387642 Ref: install/index inst-alt-install-home11387642 Ref: 41be11387642 Node: Alternate installation Unix the prefix scheme11389443 Ref: install/index alternate-installation-unix-the-prefix-scheme11389651 Ref: 41c011389651 Ref: install/index inst-alt-install-prefix-unix11389651 Ref: 41c111389651 Node: Alternate installation Windows the prefix scheme11393686 Ref: install/index alternate-installation-windows-the-prefix-scheme11393847 Ref: 41c211393847 Ref: install/index inst-alt-install-prefix-windows11393847 Ref: 41c311393847 Node: Custom Installation11395114 Ref: install/index custom-installation11395279 Ref: 41c411395279 Ref: install/index inst-custom-install11395279 Ref: 41ba11395279 Node: Modifying Python’s Search Path11402268 Ref: install/index inst-search-path11402356 Ref: 41bf11402356 Ref: install/index modifying-python-s-search-path11402356 Ref: 41c511402356 Node: Distutils Configuration Files11406078 Ref: install/index distutils-configuration-files11406256 Ref: 41c611406256 Ref: install/index inst-config-files11406256 Ref: 41b611406256 Node: Location and names of config files11406967 Ref: install/index inst-config-filenames11407098 Ref: 41c711407098 Ref: install/index location-and-names-of-config-files11407098 Ref: 41c811407098 Node: Syntax of config files11411026 Ref: install/index inst-config-syntax11411157 Ref: 40e111411157 Ref: install/index syntax-of-config-files11411157 Ref: 41c911411157 Node: Building Extensions Tips and Tricks11413083 Ref: install/index building-extensions-tips-and-tricks11413233 Ref: 41ca11413233 Ref: install/index inst-building-ext11413233 Ref: 41cb11413233 Node: Tweaking compiler/linker flags11413839 Ref: install/index inst-tweak-flags11413990 Ref: 41cc11413990 Ref: install/index tweaking-compiler-linker-flags11413990 Ref: 41cd11413990 Node: Using non-Microsoft compilers on Windows11417059 Ref: install/index inst-non-ms-compilers11417210 Ref: 41ce11417210 Ref: install/index using-non-microsoft-compilers-on-windows11417210 Ref: 41cf11417210 Node: Borland/CodeGear C++11417369 Ref: install/index borland-codegear-c11417497 Ref: 41d011417497 Ref: Borland/CodeGear C++-Footnote-111419453 Ref: Borland/CodeGear C++-Footnote-211419564 Ref: Borland/CodeGear C++-Footnote-311419609 Node: GNU C / Cygwin / MinGW11419663 Ref: install/index gnu-c-cygwin-mingw11419791 Ref: 41d111419791 Ref: GNU C / Cygwin / MinGW-Footnote-111420799 Ref: GNU C / Cygwin / MinGW-Footnote-211420879 Node: Older Versions of Python and MinGW11420980 Ref: install/index older-versions-of-python-and-mingw11421073 Ref: 41d211421073 Ref: Older Versions of Python and MinGW-Footnote-111422728 Node: Python Module Index11422793 Node: Index11445313 Ref: 31f113190514 Ref: using/cmdline audit_event_cpython_run_stdin_013190544 Ref: using/cmdline audit_event_cpython_run_file_013190575 Ref: 31f013190606  End Tag Table  Local Variables: coding: utf-8 End: